diff --git a/-8mPXAsX3DY.txt b/-8mPXAsX3DY.txt new file mode 100644 index 0000000000000000000000000000000000000000..4ccf2cacbd6d12c0506454ae66e9a932118cbe82 --- /dev/null +++ b/-8mPXAsX3DY.txt @@ -0,0 +1,1928 @@ +align:start position:0% + +the simplest quantum system + + align:start position:0% + + + + align:start position:0% + +quantum + + align:start position:0% + + + + align:start position:0% + +system + + align:start position:0% +system + + + align:start position:0% +system +so in order to decide what could be the + + align:start position:0% +so in order to decide what could be the + + + align:start position:0% +so in order to decide what could be the +simplest quantum system you could say + + align:start position:0% +simplest quantum system you could say + + + align:start position:0% +simplest quantum system you could say +well particle in a box it's very simple + + align:start position:0% +well particle in a box it's very simple + + + align:start position:0% +well particle in a box it's very simple +but in a sense it's not all that simple + + align:start position:0% +but in a sense it's not all that simple + + + align:start position:0% +but in a sense it's not all that simple +it has + + align:start position:0% +it has + + + align:start position:0% +it has +infinitely many states + + align:start position:0% +infinitely many states + + + align:start position:0% +infinitely many states +all these functions on an interval and + + align:start position:0% +all these functions on an interval and + + + align:start position:0% +all these functions on an interval and +then the energion says were infinitely + + align:start position:0% +then the energion says were infinitely + + + align:start position:0% +then the energion says were infinitely +many of them so not that simple okay so + + align:start position:0% +many of them so not that simple okay so + + + align:start position:0% +many of them so not that simple okay so +infinite bound states something with one + + align:start position:0% +infinite bound states something with one + + + align:start position:0% +infinite bound states something with one +bouncing okay a delta function potential + + align:start position:0% +bouncing okay a delta function potential + + + align:start position:0% +bouncing okay a delta function potential +just one bound state but it has + + align:start position:0% +just one bound state but it has + + + align:start position:0% +just one bound state but it has +infinitely many scattering States but + + align:start position:0% +infinitely many scattering States but + + + align:start position:0% +infinitely many scattering States but +still + + align:start position:0% +still + + + align:start position:0% +still +complicated so what is it what could be + + align:start position:0% +complicated so what is it what could be + + + align:start position:0% +complicated so what is it what could be +simpler well suppose you have the + + align:start position:0% +simpler well suppose you have the + + + align:start position:0% +simpler well suppose you have the +Schrodinger equation + + align:start position:0% + + + + align:start position:0% + +H sy and + + align:start position:0% +H sy and + + + align:start position:0% +H sy and +we work in general we know that this + + align:start position:0% +we work in general we know that this + + + align:start position:0% +we work in general we know that this +thing has energy eigenstates and + + align:start position:0% +thing has energy eigenstates and + + + align:start position:0% +thing has energy eigenstates and +probably we should focus on them + + align:start position:0% +probably we should focus on them + + + align:start position:0% +probably we should focus on them +subsequent to the minus I P over H bar + + align:start position:0% +subsequent to the minus I P over H bar + + + align:start position:0% +subsequent to the minus I P over H bar +little sy and then you have h sy equal + + align:start position:0% +little sy and then you have h sy equal + + + align:start position:0% +little sy and then you have h sy equal +each side + + align:start position:0% +each side + + + align:start position:0% +each side +so that is quantum mechanics and you + + align:start position:0% +so that is quantum mechanics and you + + + align:start position:0% +so that is quantum mechanics and you +could say well you know it's up to me to + + align:start position:0% +could say well you know it's up to me to + + + align:start position:0% +could say well you know it's up to me to +decide what the Hamiltonian is if I want + + align:start position:0% +decide what the Hamiltonian is if I want + + + align:start position:0% +decide what the Hamiltonian is if I want +to invent the simplest quantum + + align:start position:0% +to invent the simplest quantum + + + align:start position:0% +to invent the simplest quantum +mechanical system on the other hand + + align:start position:0% +mechanical system on the other hand + + + align:start position:0% +mechanical system on the other hand +there are some things that should be + + align:start position:0% +there are some things that should be + + + align:start position:0% +there are some things that should be +true + + align:start position:0% +true + + + align:start position:0% +true +these are complex numbers + + align:start position:0% +these are complex numbers + + + align:start position:0% +these are complex numbers +energies H must be an operator that has + + align:start position:0% +energies H must be an operator that has + + + align:start position:0% +energies H must be an operator that has +units of energy + + align:start position:0% +units of energy + + + align:start position:0% +units of energy +and we also saw that if we want + + align:start position:0% +and we also saw that if we want + + + align:start position:0% +and we also saw that if we want +probabilities that are going to be + + align:start position:0% +probabilities that are going to be + + + align:start position:0% +probabilities that are going to be +associated with size squared + + align:start position:0% +associated with size squared + + + align:start position:0% +associated with size squared +to be conserved we need H to be + + align:start position:0% +to be conserved we need H to be + + + align:start position:0% +to be conserved we need H to be +hermitian so there should be some notion + + align:start position:0% +hermitian so there should be some notion + + + align:start position:0% +hermitian so there should be some notion +of inner product some sort of + + align:start position:0% +of inner product some sort of + + + align:start position:0% +of inner product some sort of +operation that gives us numbers we used + + align:start position:0% +operation that gives us numbers we used + + + align:start position:0% +operation that gives us numbers we used +to defy psy that gives a number + + align:start position:0% +to defy psy that gives a number + + + align:start position:0% +to defy psy that gives a number +also complex numbers in general and it + + align:start position:0% +also complex numbers in general and it + + + align:start position:0% +also complex numbers in general and it +has the property at some point + + align:start position:0% +has the property at some point + + + align:start position:0% +has the property at some point +conjugates this thing it has this and + + align:start position:0% +conjugates this thing it has this and + + + align:start position:0% +conjugates this thing it has this and +integrates but maybe if you're doing the + + align:start position:0% +integrates but maybe if you're doing the + + + align:start position:0% +integrates but maybe if you're doing the +simplest quantum mechanical system in + + align:start position:0% +simplest quantum mechanical system in + + + align:start position:0% +simplest quantum mechanical system in +the world it will be simpler than at + + align:start position:0% +the world it will be simpler than at + + + align:start position:0% +the world it will be simpler than at +integral integrals are complicated but + + align:start position:0% +integral integrals are complicated but + + + align:start position:0% +integral integrals are complicated but +anyway we have something like that and + + align:start position:0% +anyway we have something like that and + + + align:start position:0% +anyway we have something like that and +we want + + align:start position:0% +we want + + + align:start position:0% +we want +H to + + align:start position:0% +H to + + + align:start position:0% +H to +be hermitian so let me write the same + + align:start position:0% +be hermitian so let me write the same + + + align:start position:0% +be hermitian so let me write the same +for any operator a + + align:start position:0% + + + + align:start position:0% + +this is equal to a dagger + + align:start position:0% +this is equal to a dagger + + + align:start position:0% +this is equal to a dagger +sy and + + align:start position:0% +sy and + + + align:start position:0% +sy and +that's a hermitian conjugate that's a + + align:start position:0% +that's a hermitian conjugate that's a + + + align:start position:0% +that's a hermitian conjugate that's a +general definition and we want H to be + + align:start position:0% +general definition and we want H to be + + + align:start position:0% +general definition and we want H to be +hermitian so H + + align:start position:0% +hermitian so H + + + align:start position:0% +hermitian so H +dagger equal H + + align:start position:0% + + + + align:start position:0% + +okay so in some sense you could say + + align:start position:0% +okay so in some sense you could say + + + align:start position:0% +okay so in some sense you could say +there that's quantum mechanics for you + + align:start position:0% +there that's quantum mechanics for you + + + align:start position:0% +there that's quantum mechanics for you +it's a Schrodinger equation a + + align:start position:0% +it's a Schrodinger equation a + + + align:start position:0% +it's a Schrodinger equation a +Hamiltonian an inner product a notion of + + align:start position:0% +Hamiltonian an inner product a notion of + + + align:start position:0% +Hamiltonian an inner product a notion of +hermitian operators and then you're + + align:start position:0% +hermitian operators and then you're + + + align:start position:0% +hermitian operators and then you're +supposed to solve it and what we've done + + align:start position:0% +supposed to solve it and what we've done + + + align:start position:0% +supposed to solve it and what we've done +is solved this for a whole semester and + + align:start position:0% +is solved this for a whole semester and + + + align:start position:0% +is solved this for a whole semester and +try to understand + + align:start position:0% +try to understand + + + align:start position:0% +try to understand +some physics out of it + + align:start position:0% +some physics out of it + + + align:start position:0% +some physics out of it +but we started with the notion that + + align:start position:0% +but we started with the notion that + + + align:start position:0% +but we started with the notion that +something simple would be a particle + + align:start position:0% +something simple would be a particle + + + align:start position:0% +something simple would be a particle +living in one dimension and that's a + + align:start position:0% +living in one dimension and that's a + + + align:start position:0% +living in one dimension and that's a +very reasonable thought + + align:start position:0% +very reasonable thought + + + align:start position:0% +very reasonable thought +motivated from classical mechanics + + align:start position:0% +motivated from classical mechanics + + + align:start position:0% +motivated from classical mechanics +that + + align:start position:0% +that + + + align:start position:0% +that +surely we have particles that move and + + align:start position:0% +surely we have particles that move and + + + align:start position:0% +surely we have particles that move and +moving in three dimensions is more + + align:start position:0% +moving in three dimensions is more + + + align:start position:0% +moving in three dimensions is more +complicated so we waited towards the end + + align:start position:0% +complicated so we waited towards the end + + + align:start position:0% +complicated so we waited towards the end +of the semester to do three dimensions + + align:start position:0% +of the semester to do three dimensions + + + align:start position:0% +of the semester to do three dimensions +but moving in one dimension is already + + align:start position:0% +but moving in one dimension is already + + + align:start position:0% +but moving in one dimension is already +kind of interesting and complicated so + + align:start position:0% +kind of interesting and complicated so + + + align:start position:0% +kind of interesting and complicated so +we had size of X that represented the + + align:start position:0% +we had size of X that represented the + + + align:start position:0% +we had size of X that represented the +fact that the particle could be anywhere + + align:start position:0% +fact that the particle could be anywhere + + + align:start position:0% +fact that the particle could be anywhere +here + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% + + + + align:start position:0% + +how can I simplify this well the key to + + align:start position:0% +how can I simplify this well the key to + + + align:start position:0% +how can I simplify this well the key to +simplifying this is maybe + + align:start position:0% +simplifying this is maybe + + + align:start position:0% +simplifying this is maybe +not to be too attached to the physics + + align:start position:0% +not to be too attached to the physics + + + align:start position:0% +not to be too attached to the physics +for a while and try to visualize what + + align:start position:0% +for a while and try to visualize what + + + align:start position:0% +for a while and try to visualize what +could you describe that was simpler so + + align:start position:0% +could you describe that was simpler so + + + align:start position:0% +could you describe that was simpler so +suppose the particle could only live at + + align:start position:0% +suppose the particle could only live at + + + align:start position:0% +suppose the particle could only live at +two points X 1 and X 2 + + align:start position:0% +two points X 1 and X 2 + + + align:start position:0% +two points X 1 and X 2 +the particle can be here or here + + align:start position:0% +the particle can be here or here + + + align:start position:0% +the particle can be here or here +now if cut the real line down to just + + align:start position:0% +now if cut the real line down to just + + + align:start position:0% +now if cut the real line down to just +two points you can only be in this point + + align:start position:0% +two points you can only be in this point + + + align:start position:0% +two points you can only be in this point +or that point + + align:start position:0% +or that point + + + align:start position:0% +or that point +and you say that's very in physical but + + align:start position:0% +and you say that's very in physical but + + + align:start position:0% +and you say that's very in physical but +let's wait a second and think of this + + align:start position:0% +let's wait a second and think of this + + + align:start position:0% +let's wait a second and think of this +what does that mean well we used to have + + align:start position:0% +what does that mean well we used to have + + + align:start position:0% +what does that mean well we used to have +a sigh of X that could be anywhere and + + align:start position:0% +a sigh of X that could be anywhere and + + + align:start position:0% +a sigh of X that could be anywhere and +we wrote it as a function but now that + + align:start position:0% +we wrote it as a function but now that + + + align:start position:0% +we wrote it as a function but now that +it can if I think of this the simplest + + align:start position:0% +it can if I think of this the simplest + + + align:start position:0% +it can if I think of this the simplest +thing ok the simplest thing is a + + align:start position:0% +thing ok the simplest thing is a + + + align:start position:0% +thing ok the simplest thing is a +particle is just at one point there's + + align:start position:0% +particle is just at one point there's + + + align:start position:0% +particle is just at one point there's +only one point the whole world for the + + align:start position:0% +only one point the whole world for the + + + align:start position:0% +only one point the whole world for the +particle is one point and it's there but + + align:start position:0% +particle is one point and it's there but + + + align:start position:0% +particle is one point and it's there but +that probably is not too interesting + + align:start position:0% +that probably is not too interesting + + + align:start position:0% +that probably is not too interesting +because the particle is there the + + align:start position:0% +because the particle is there the + + + align:start position:0% +because the particle is there the +probability to find it there is always 1 + + align:start position:0% +probability to find it there is always 1 + + + align:start position:0% +probability to find it there is always 1 +and what can you do with it oh but if + + align:start position:0% +and what can you do with it oh but if + + + align:start position:0% +and what can you do with it oh but if +you have two points there's room for + + align:start position:0% +you have two points there's room for + + + align:start position:0% +you have two points there's room for +funny things to happen so we'll assume + + align:start position:0% +funny things to happen so we'll assume + + + align:start position:0% +funny things to happen so we'll assume +that the particle can be in two points + + align:start position:0% +that the particle can be in two points + + + align:start position:0% +that the particle can be in two points +so from all of this sigh effects + + align:start position:0% + + + + align:start position:0% + +will go to a new PI of X that has + + align:start position:0% +will go to a new PI of X that has + + + align:start position:0% +will go to a new PI of X that has +two pieces of information the value of y + + align:start position:0% +two pieces of information the value of y + + + align:start position:0% +two pieces of information the value of y +at X 1 and the value of y at X 2 and + + align:start position:0% +at X 1 and the value of y at X 2 and + + + align:start position:0% +at X 1 and the value of y at X 2 and +those are two numbers alpha and beta + + align:start position:0% + + + + align:start position:0% + +alpha squared would be + + align:start position:0% +alpha squared would be + + + align:start position:0% +alpha squared would be +the probability to + + align:start position:0% +the probability to + + + align:start position:0% +the probability to +be at X 1 + + align:start position:0% +be at X 1 + + + align:start position:0% +be at X 1 +beta squared would be the probability to + + align:start position:0% +beta squared would be the probability to + + + align:start position:0% +beta squared would be the probability to +be at X 2 + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% + + + + align:start position:0% + +this may remind you already of something + + align:start position:0% +this may remind you already of something + + + align:start position:0% +this may remind you already of something +we're doing with interferometers in + + align:start position:0% +we're doing with interferometers in + + + align:start position:0% +we're doing with interferometers in +which the photon could be in the upper + + align:start position:0% +which the photon could be in the upper + + + align:start position:0% +which the photon could be in the upper +branch or the lower branch and you had + + align:start position:0% +branch or the lower branch and you had + + + align:start position:0% +branch or the lower branch and you had +two numbers so this is somewhat + + align:start position:0% +two numbers so this is somewhat + + + align:start position:0% +two numbers so this is somewhat +analogous except that the interferometer + + align:start position:0% +analogous except that the interferometer + + + align:start position:0% +analogous except that the interferometer +you could eventually + + align:start position:0% +you could eventually + + + align:start position:0% +you could eventually +put more beam splitters and have maybe + + align:start position:0% +put more beam splitters and have maybe + + + align:start position:0% +put more beam splitters and have maybe +later 3 branches or 4 branches or things + + align:start position:0% +later 3 branches or 4 branches or things + + + align:start position:0% +later 3 branches or 4 branches or things +like that here I want to consider two + + align:start position:0% +like that here I want to consider two + + + align:start position:0% +like that here I want to consider two +things + + align:start position:0% +things + + + align:start position:0% +things +particle there so one thing that this + + align:start position:0% +particle there so one thing that this + + + align:start position:0% +particle there so one thing that this +could be could be strictly that but now + + align:start position:0% +could be could be strictly that but now + + + align:start position:0% +could be could be strictly that but now +let's relax our + + align:start position:0% +let's relax our + + + align:start position:0% +let's relax our +assumption so you could also mean for + + align:start position:0% +assumption so you could also mean for + + + align:start position:0% +assumption so you could also mean for +example that you have a box and a + + align:start position:0% +example that you have a box and a + + + align:start position:0% +example that you have a box and a +partition and there's the left side of + + align:start position:0% +partition and there's the left side of + + + align:start position:0% +partition and there's the left side of +the box and the right side of the box + + align:start position:0% +the box and the right side of the box + + + align:start position:0% +the box and the right side of the box +and the molecule can either be on the + + align:start position:0% +and the molecule can either be on the + + + align:start position:0% +and the molecule can either be on the +left side or on the right side + + align:start position:0% +left side or on the right side + + + align:start position:0% +left side or on the right side +that's a fairly physical + + align:start position:0% +that's a fairly physical + + + align:start position:0% +that's a fairly physical +question + + align:start position:0% +question + + + align:start position:0% +question +so here you could be probability + + align:start position:0% +so here you could be probability + + + align:start position:0% +so here you could be probability +the amplitude + + align:start position:0% +the amplitude + + + align:start position:0% +the amplitude +amplitude to be on the left or amplitude + + align:start position:0% +amplitude to be on the left or amplitude + + + align:start position:0% +amplitude to be on the left or amplitude +to be on right two component vector just + + align:start position:0% +to be on right two component vector just + + + align:start position:0% +to be on right two component vector just +like that one would be the amplitude to + + align:start position:0% +like that one would be the amplitude to + + + align:start position:0% +like that one would be the amplitude to +be in either one and maybe the template + + align:start position:0% +be in either one and maybe the template + + + align:start position:0% +be in either one and maybe the template +changes in time or it could be that you + + align:start position:0% +changes in time or it could be that you + + + align:start position:0% +changes in time or it could be that you +have a particle + + align:start position:0% +have a particle + + + align:start position:0% +have a particle +and + + align:start position:0% +and + + + align:start position:0% +and +suddenly you discover that yeah the + + align:start position:0% +suddenly you discover that yeah the + + + align:start position:0% +suddenly you discover that yeah the +particle is at rest it's not moving it's + + align:start position:0% +particle is at rest it's not moving it's + + + align:start position:0% +particle is at rest it's not moving it's +not doing anything it's at one single + + align:start position:0% +not doing anything it's at one single + + + align:start position:0% +not doing anything it's at one single +point not two points but actually this + + align:start position:0% +point not two points but actually this + + + align:start position:0% +point not two points but actually this +particle has maybe something called spin + + align:start position:0% +particle has maybe something called spin + + + align:start position:0% +particle has maybe something called spin +and the spin can be up or the spin can + + align:start position:0% +and the spin can be up or the spin can + + + align:start position:0% +and the spin can be up or the spin can +be down + + align:start position:0% +be down + + + align:start position:0% +be down +well we could invent something we could + + align:start position:0% +well we could invent something we could + + + align:start position:0% +well we could invent something we could +call it spin or a particle + + align:start position:0% +call it spin or a particle + + + align:start position:0% +call it spin or a particle +could be in this state or in that state + + align:start position:0% +could be in this state or in that state + + + align:start position:0% +could be in this state or in that state +even if that's possible for a particle + + align:start position:0% +even if that's possible for a particle + + + align:start position:0% +even if that's possible for a particle +you could have here the amplitude + + align:start position:0% +you could have here the amplitude + + + align:start position:0% +you could have here the amplitude +for up + + align:start position:0% +for up + + + align:start position:0% +for up +spin and the amplitude for down + + align:start position:0% +spin and the amplitude for down + + + align:start position:0% +spin and the amplitude for down +spin and + + align:start position:0% +spin and + + + align:start position:0% +spin and +those would be the two numbers so you + + align:start position:0% +those would be the two numbers so you + + + align:start position:0% +those would be the two numbers so you +know it's lots of possibilities in a + + align:start position:0% +know it's lots of possibilities in a + + + align:start position:0% +know it's lots of possibilities in a +sense this is a + + align:start position:0% +sense this is a + + + align:start position:0% +sense this is a +classic problem waiting for a physical + + align:start position:0% +classic problem waiting for a physical + + + align:start position:0% +classic problem waiting for a physical +application in quantum mechanics so + + align:start position:0% +application in quantum mechanics so + + + align:start position:0% +application in quantum mechanics so +let's + + align:start position:0% +let's + + + align:start position:0% +let's +push it a little more + + align:start position:0% + + + + align:start position:0% + +now + + align:start position:0% + + + + align:start position:0% + +how would we do inner products you know + + align:start position:0% +how would we do inner products you know + + + align:start position:0% +how would we do inner products you know +we decided okay you need to do inner + + align:start position:0% +we decided okay you need to do inner + + + align:start position:0% +we decided okay you need to do inner +products and + + align:start position:0% +products and + + + align:start position:0% +products and +what was the inner product of two + + align:start position:0% +what was the inner product of two + + + align:start position:0% +what was the inner product of two +functions Phi and psi was the integral + + align:start position:0% +functions Phi and psi was the integral + + + align:start position:0% +functions Phi and psi was the integral +DX of Phi star of X 1 times a 5 star of + + align:start position:0% +DX of Phi star of X 1 times a 5 star of + + + align:start position:0% +DX of Phi star of X 1 times a 5 star of +X times Phi of X and what you're really + + align:start position:0% +X times Phi of X and what you're really + + + align:start position:0% +X times Phi of X and what you're really +doing is taking the values of the first + + align:start position:0% +doing is taking the values of the first + + + align:start position:0% +doing is taking the values of the first +wave function at one point complex + + align:start position:0% +wave function at one point complex + + + align:start position:0% +wave function at one point complex +conjugate and you take the value of the + + align:start position:0% +conjugate and you take the value of the + + + align:start position:0% +conjugate and you take the value of the +second wave function at the same point + + align:start position:0% +second wave function at the same point + + + align:start position:0% +second wave function at the same point +compress conjugating it so if you would + + align:start position:0% +compress conjugating it so if you would + + + align:start position:0% +compress conjugating it so if you would +have two vectors like this + + align:start position:0% +have two vectors like this + + + align:start position:0% +have two vectors like this +alpha and + + align:start position:0% +alpha and + + + align:start position:0% +alpha and +beta the + + align:start position:0% +beta the + + + align:start position:0% +beta the +first wave function alpha 1 beta 1 and + + align:start position:0% +first wave function alpha 1 beta 1 and + + + align:start position:0% +first wave function alpha 1 beta 1 and +the second wave function alpha 2 beta 2 + + align:start position:0% +the second wave function alpha 2 beta 2 + + + align:start position:0% +the second wave function alpha 2 beta 2 +the inner product psy 1 psy + + align:start position:0% +the inner product psy 1 psy + + + align:start position:0% +the inner product psy 1 psy + + align:start position:0% + + + align:start position:0% +should be the analog of this thing which + + align:start position:0% +should be the analog of this thing which + + + align:start position:0% +should be the analog of this thing which +is multiplied things at the same point + + align:start position:0% +is multiplied things at the same point + + + align:start position:0% +is multiplied things at the same point +so you should do the alpha 1 star that's + + align:start position:0% +so you should do the alpha 1 star that's + + + align:start position:0% +so you should do the alpha 1 star that's +alpha 2 + + align:start position:0% +alpha 2 + + + align:start position:0% +alpha 2 +plus beta 1 star and beta 2 + + align:start position:0% +plus beta 1 star and beta 2 + + + align:start position:0% +plus beta 1 star and beta 2 +that would be the nice way to do this + + align:start position:0% + + + + align:start position:0% + +you could think of this as having + + align:start position:0% + + + + align:start position:0% + +transposed this alpha 1 and complex + + align:start position:0% +transposed this alpha 1 and complex + + + align:start position:0% +transposed this alpha 1 and complex +conjugated it beta 1 and then the matrix + + align:start position:0% +conjugated it beta 1 and then the matrix + + + align:start position:0% +conjugated it beta 1 and then the matrix +product with alpha 1 beta 1 + + align:start position:0% +product with alpha 1 beta 1 + + + align:start position:0% +product with alpha 1 beta 1 +so u transpose complex conjugate the + + align:start position:0% +so u transpose complex conjugate the + + + align:start position:0% +so u transpose complex conjugate the +first and + + align:start position:0% +first and + + + align:start position:0% +first and +you do that with a second you know + + align:start position:0% +you do that with a second you know + + + align:start position:0% +you do that with a second you know +when you study a little more mechanics + + align:start position:0% +when you study a little more mechanics + + + align:start position:0% +when you study a little more mechanics +in 805 you will explore this analogy + + align:start position:0% +in 805 you will explore this analogy + + + align:start position:0% +in 805 you will explore this analogy +even more in that you will think of a + + align:start position:0% +even more in that you will think of a + + + align:start position:0% +even more in that you will think of a +way function as a column vector infinite + + align:start position:0% +way function as a column vector infinite + + + align:start position:0% +way function as a column vector infinite +one side at zero PI epsilon Phi 2 + + align:start position:0% +one side at zero PI epsilon Phi 2 + + + align:start position:0% +one side at zero PI epsilon Phi 2 +epsilon + + align:start position:0% +epsilon + + + align:start position:0% +epsilon +sired minus epsilon so you've + + align:start position:0% +sired minus epsilon so you've + + + align:start position:0% +sired minus epsilon so you've +sliced the x-axis and a certain infinite + + align:start position:0% +sliced the x-axis and a certain infinite + + + align:start position:0% +sliced the x-axis and a certain infinite +vector and that's your old way function + + align:start position:0% +vector and that's your old way function + + + align:start position:0% +vector and that's your old way function +so it's not so unnatural to do this and + + align:start position:0% +so it's not so unnatural to do this and + + + align:start position:0% +so it's not so unnatural to do this and +this will be our inner product + + align:start position:0% +this will be our inner product + + + align:start position:0% +this will be our inner product +so how about H being hermitian + + align:start position:0% +so how about H being hermitian + + + align:start position:0% +so how about H being hermitian +median + + align:start position:0% +median + + + align:start position:0% +median +that just means for matrices that age + + align:start position:0% +that just means for matrices that age + + + align:start position:0% +that just means for matrices that age +transpose complex conjugated that's + + align:start position:0% +transpose complex conjugated that's + + + align:start position:0% +transpose complex conjugated that's +dagger hermitian is equal to h and + + align:start position:0% +dagger hermitian is equal to h and + + + align:start position:0% +dagger hermitian is equal to h and +you may have seen that that's what + + align:start position:0% +you may have seen that that's what + + + align:start position:0% +you may have seen that that's what +dagger means you transpose on her and + + align:start position:0% +dagger means you transpose on her and + + + align:start position:0% +dagger means you transpose on her and +complex conjugate if you haven't seen it + + align:start position:0% +complex conjugate if you haven't seen it + + + align:start position:0% +complex conjugate if you haven't seen it +you could prove it now using this rule + + align:start position:0% +you could prove it now using this rule + + + align:start position:0% +you could prove it now using this rule +for the inner product because the inner + + align:start position:0% +for the inner product because the inner + + + align:start position:0% +for the inner product because the inner +product will tell you how to construct + + align:start position:0% +product will tell you how to construct + + + align:start position:0% +product will tell you how to construct +the complex the dagger of any operator + + align:start position:0% +the complex the dagger of any operator + + + align:start position:0% +the complex the dagger of any operator +and you will find that indeed the dagger + + align:start position:0% +and you will find that indeed the dagger + + + align:start position:0% +and you will find that indeed the dagger +what it does is transpose this and + + align:start position:0% +what it does is transpose this and + + + align:start position:0% +what it does is transpose this and +complex conjugates and it's sort of + + align:start position:0% +complex conjugates and it's sort of + + + align:start position:0% +complex conjugates and it's sort of +comes because the inner product + + align:start position:0% +comes because the inner product + + + align:start position:0% +comes because the inner product +transposes and complex conjugates the + + align:start position:0% +transposes and complex conjugates the + + + align:start position:0% +transposes and complex conjugates the +first object \ No newline at end of file diff --git a/-IWKPe6X6Vs.txt b/-IWKPe6X6Vs.txt new file mode 100644 index 0000000000000000000000000000000000000000..0006f9fa69a5b6e05a60df4de4a340780a407663 --- /dev/null +++ b/-IWKPe6X6Vs.txt @@ -0,0 +1,2627 @@ +align:start position:0% + +after flipping a coin 100 times you + + align:start position:0% +after flipping a coin 100 times you + + + align:start position:0% +after flipping a coin 100 times you +tally out 42 heads and 58 + + align:start position:0% +tally out 42 heads and 58 + + + align:start position:0% +tally out 42 heads and 58 +tails you expected a 50/50 + + align:start position:0% +tails you expected a 50/50 + + + align:start position:0% +tails you expected a 50/50 +distribution does this mean the coin is + + align:start position:0% +distribution does this mean the coin is + + + align:start position:0% +distribution does this mean the coin is +unfair this video is part of the + + align:start position:0% +unfair this video is part of the + + + align:start position:0% +unfair this video is part of the +probability and statistics video + + align:start position:0% +probability and statistics video + + + align:start position:0% +probability and statistics video +series many events and phenomena are + + align:start position:0% +series many events and phenomena are + + + align:start position:0% +series many events and phenomena are +probabilistic Engineers designers and + + align:start position:0% +probabilistic Engineers designers and + + + align:start position:0% +probabilistic Engineers designers and +Architects often use probability + + align:start position:0% +Architects often use probability + + + align:start position:0% +Architects often use probability +distributions to predict system + + align:start position:0% +distributions to predict system + + + align:start position:0% +distributions to predict system +Behavior hi my name is lorda salaman and + + align:start position:0% +Behavior hi my name is lorda salaman and + + + align:start position:0% +Behavior hi my name is lorda salaman and +I'm a research scientist in the hhmi + + align:start position:0% +I'm a research scientist in the hhmi + + + align:start position:0% +I'm a research scientist in the hhmi +education group in the biology + + align:start position:0% +education group in the biology + + + align:start position:0% +education group in the biology +department at MIT I also work in the MIT + + align:start position:0% +department at MIT I also work in the MIT + + + align:start position:0% +department at MIT I also work in the MIT +office of educational Innovation and + + align:start position:0% +office of educational Innovation and + + + align:start position:0% +office of educational Innovation and +Technology I helped de velop the star + + align:start position:0% +Technology I helped de velop the star + + + align:start position:0% +Technology I helped de velop the star +genetic software feature in this + + align:start position:0% +genetic software feature in this + + + align:start position:0% +genetic software feature in this +video before watching this video you + + align:start position:0% +video before watching this video you + + + align:start position:0% +video before watching this video you +should know what a probability + + align:start position:0% +should know what a probability + + + align:start position:0% +should know what a probability +distribution is and be familiar with + + align:start position:0% +distribution is and be familiar with + + + align:start position:0% +distribution is and be familiar with +basic genetics vocabulary including + + align:start position:0% +basic genetics vocabulary including + + + align:start position:0% +basic genetics vocabulary including +genotype phenotype homozygous and + + align:start position:0% +genotype phenotype homozygous and + + + align:start position:0% +genotype phenotype homozygous and +heterozygous you should also know how to + + align:start position:0% +heterozygous you should also know how to + + + align:start position:0% +heterozygous you should also know how to +use punet squares to predict the + + align:start position:0% +use punet squares to predict the + + + align:start position:0% +use punet squares to predict the +expected results of melan crosses + + align:start position:0% +expected results of melan crosses + + + align:start position:0% +expected results of melan crosses +after watching this video you will be + + align:start position:0% +after watching this video you will be + + + align:start position:0% +after watching this video you will be +able to apply Ki Square hypothesis + + align:start position:0% +able to apply Ki Square hypothesis + + + align:start position:0% +able to apply Ki Square hypothesis +testing to experimental data obtained + + align:start position:0% +testing to experimental data obtained + + + align:start position:0% +testing to experimental data obtained +from genetic + + align:start position:0% + + + + align:start position:0% + +experiments going back to the question + + align:start position:0% +experiments going back to the question + + + align:start position:0% +experiments going back to the question +of whether or not our coin is fair it + + align:start position:0% +of whether or not our coin is fair it + + + align:start position:0% +of whether or not our coin is fair it +turns out there is statistical tool that + + align:start position:0% +turns out there is statistical tool that + + + align:start position:0% +turns out there is statistical tool that +can help + + align:start position:0% +can help + + + align:start position:0% +can help +us statistical tests can be used to + + align:start position:0% +us statistical tests can be used to + + + align:start position:0% +us statistical tests can be used to +determ determined if sample data can be + + align:start position:0% +determ determined if sample data can be + + + align:start position:0% +determ determined if sample data can be +assumed to come from a population that + + align:start position:0% +assumed to come from a population that + + + align:start position:0% +assumed to come from a population that +has a certain + + align:start position:0% +has a certain + + + align:start position:0% +has a certain +distribution today we will use the + + align:start position:0% +distribution today we will use the + + + align:start position:0% +distribution today we will use the +statistical test called the kai Square + + align:start position:0% +statistical test called the kai Square + + + align:start position:0% +statistical test called the kai Square +test for goodness of + + align:start position:0% +test for goodness of + + + align:start position:0% +test for goodness of +fit the Ki Square test is used to + + align:start position:0% +fit the Ki Square test is used to + + + align:start position:0% +fit the Ki Square test is used to +analyze categorical data in other words + + align:start position:0% +analyze categorical data in other words + + + align:start position:0% +analyze categorical data in other words +the test Compares a sample of data + + align:start position:0% +the test Compares a sample of data + + + align:start position:0% +the test Compares a sample of data +collected about an event to expected + + align:start position:0% +collected about an event to expected + + + align:start position:0% +collected about an event to expected +values in our coin flipping example our + + align:start position:0% +values in our coin flipping example our + + + align:start position:0% +values in our coin flipping example our +categories are heads and + + align:start position:0% +categories are heads and + + + align:start position:0% +categories are heads and +tails an event is one coin + + align:start position:0% +tails an event is one coin + + + align:start position:0% +tails an event is one coin +flip our sample is 100 + + align:start position:0% +flip our sample is 100 + + + align:start position:0% +flip our sample is 100 +events we expect that the coin should + + align:start position:0% +events we expect that the coin should + + + align:start position:0% +events we expect that the coin should +have a 5050 chance of being heads or + + align:start position:0% +have a 5050 chance of being heads or + + + align:start position:0% +have a 5050 chance of being heads or +tails in any given event + + align:start position:0% +tails in any given event + + + align:start position:0% +tails in any given event +the question we are trying to answer is + + align:start position:0% +the question we are trying to answer is + + + align:start position:0% +the question we are trying to answer is +does our sample come from the 5050 + + align:start position:0% +does our sample come from the 5050 + + + align:start position:0% +does our sample come from the 5050 +population distribution we + + align:start position:0% +population distribution we + + + align:start position:0% +population distribution we +expect what we have just done is State + + align:start position:0% +expect what we have just done is State + + + align:start position:0% +expect what we have just done is State +our null hypothesis about the coin + + align:start position:0% +our null hypothesis about the coin + + + align:start position:0% +our null hypothesis about the coin +flipping + + align:start position:0% +flipping + + + align:start position:0% +flipping +experiment the kai Square statistics + + align:start position:0% +experiment the kai Square statistics + + + align:start position:0% +experiment the kai Square statistics +tests this null + + align:start position:0% +tests this null + + + align:start position:0% +tests this null +hypothesis we also need to State an + + align:start position:0% +hypothesis we also need to State an + + + align:start position:0% +hypothesis we also need to State an +alternative + + align:start position:0% +alternative + + + align:start position:0% +alternative +hypothesis the alternative hypothesis is + + align:start position:0% +hypothesis the alternative hypothesis is + + + align:start position:0% +hypothesis the alternative hypothesis is +simply that the data do not come from + + align:start position:0% +simply that the data do not come from + + + align:start position:0% +simply that the data do not come from +the specify 50/50 population + + align:start position:0% + + + + align:start position:0% + +distribution before we can test our + + align:start position:0% +distribution before we can test our + + + align:start position:0% +distribution before we can test our +hypothesis we need to calculate a Kai + + align:start position:0% +hypothesis we need to calculate a Kai + + + align:start position:0% +hypothesis we need to calculate a Kai +Square + + align:start position:0% +Square + + + align:start position:0% +Square +statistic this statistic measures the + + align:start position:0% +statistic this statistic measures the + + + align:start position:0% +statistic this statistic measures the +discrepancy between observed counts and + + align:start position:0% +discrepancy between observed counts and + + + align:start position:0% +discrepancy between observed counts and +expected counts + + align:start position:0% +expected counts + + + align:start position:0% +expected counts +each term in our summation finds the + + align:start position:0% +each term in our summation finds the + + + align:start position:0% +each term in our summation finds the +deviation or error between observed and + + align:start position:0% +deviation or error between observed and + + + align:start position:0% +deviation or error between observed and +expected values for each + + align:start position:0% + + + + align:start position:0% + +category this deviation is squared to + + align:start position:0% +category this deviation is squared to + + + align:start position:0% +category this deviation is squared to +obtain positive values otherwise + + align:start position:0% +obtain positive values otherwise + + + align:start position:0% +obtain positive values otherwise +everything will sum to zero because both + + align:start position:0% +everything will sum to zero because both + + + align:start position:0% +everything will sum to zero because both +are observed and expected outcomes sum + + align:start position:0% +are observed and expected outcomes sum + + + align:start position:0% +are observed and expected outcomes sum +to the same + + align:start position:0% +to the same + + + align:start position:0% +to the same +value each term in the summation is + + align:start position:0% +value each term in the summation is + + + align:start position:0% +value each term in the summation is +divided by the expected value of the + + align:start position:0% +divided by the expected value of the + + + align:start position:0% +divided by the expected value of the +outcome as a way of normalizing each + + align:start position:0% +outcome as a way of normalizing each + + + align:start position:0% +outcome as a way of normalizing each +difference the kai Square statistic + + align:start position:0% +difference the kai Square statistic + + + align:start position:0% +difference the kai Square statistic +lives in a + + align:start position:0% +lives in a + + + align:start position:0% +lives in a +distribution this is the kai Square + + align:start position:0% +distribution this is the kai Square + + + align:start position:0% +distribution this is the kai Square +distribution for any sample that has two + + align:start position:0% +distribution for any sample that has two + + + align:start position:0% +distribution for any sample that has two +categories of data or in other words one + + align:start position:0% +categories of data or in other words one + + + align:start position:0% +categories of data or in other words one +degree of + + align:start position:0% +degree of + + + align:start position:0% +degree of +Freedom if the outut come of an event + + align:start position:0% +Freedom if the outut come of an event + + + align:start position:0% +Freedom if the outut come of an event +can only fall into one of two categories + + align:start position:0% +can only fall into one of two categories + + + align:start position:0% +can only fall into one of two categories +we only need to know how many events + + align:start position:0% +we only need to know how many events + + + align:start position:0% +we only need to know how many events +fell into one category in order to + + align:start position:0% +fell into one category in order to + + + align:start position:0% +fell into one category in order to +determine how many fell into the other + + align:start position:0% + + + + align:start position:0% + +category the Ki squar distribution is + + align:start position:0% +category the Ki squar distribution is + + + align:start position:0% +category the Ki squar distribution is +actually a set of distributions each for + + align:start position:0% +actually a set of distributions each for + + + align:start position:0% +actually a set of distributions each for +a different number of degrees of + + align:start position:0% +a different number of degrees of + + + align:start position:0% +a different number of degrees of +freedom if we look at these + + align:start position:0% +freedom if we look at these + + + align:start position:0% +freedom if we look at these +distributions the x axis is Kai Square + + align:start position:0% +distributions the x axis is Kai Square + + + align:start position:0% +distributions the x axis is Kai Square +values and the y axis is relative + + align:start position:0% +values and the y axis is relative + + + align:start position:0% +values and the y axis is relative +frequency you might also notice that + + align:start position:0% +frequency you might also notice that + + + align:start position:0% +frequency you might also notice that +these distributions are positively + + align:start position:0% +these distributions are positively + + + align:start position:0% +these distributions are positively +skewed this makes sense for a couple of + + align:start position:0% +skewed this makes sense for a couple of + + + align:start position:0% +skewed this makes sense for a couple of +reasons the Ki Square statistic is + + align:start position:0% +reasons the Ki Square statistic is + + + align:start position:0% +reasons the Ki Square statistic is +always + + align:start position:0% +always + + + align:start position:0% +always +positive larger and larger Ki Square + + align:start position:0% +positive larger and larger Ki Square + + + align:start position:0% +positive larger and larger Ki Square +values indicate larger discrepancies + + align:start position:0% +values indicate larger discrepancies + + + align:start position:0% +values indicate larger discrepancies +between observed and expected + + align:start position:0% +between observed and expected + + + align:start position:0% +between observed and expected +values while possible these large + + align:start position:0% +values while possible these large + + + align:start position:0% +values while possible these large +discrepancies are less probable if the + + align:start position:0% +discrepancies are less probable if the + + + align:start position:0% +discrepancies are less probable if the +null hypothesis is + + align:start position:0% +null hypothesis is + + + align:start position:0% +null hypothesis is +true if we calculate the Ki Square test + + align:start position:0% +true if we calculate the Ki Square test + + + align:start position:0% +true if we calculate the Ki Square test +statistic for the coin flipping + + align:start position:0% +statistic for the coin flipping + + + align:start position:0% +statistic for the coin flipping +experiment we get + + align:start position:0% + + + + align:start position:0% + +2.56 how do we interpret this + + align:start position:0% +2.56 how do we interpret this + + + align:start position:0% +2.56 how do we interpret this +number by first we need to look at the + + align:start position:0% +number by first we need to look at the + + + align:start position:0% +number by first we need to look at the +appropriate Kai Square + + align:start position:0% + + + + align:start position:0% + +distribution in the coin flipping + + align:start position:0% +distribution in the coin flipping + + + align:start position:0% +distribution in the coin flipping +experiment there are two possible + + align:start position:0% +experiment there are two possible + + + align:start position:0% +experiment there are two possible +outcomes heads or + + align:start position:0% +outcomes heads or + + + align:start position:0% +outcomes heads or +tails if we know how many heads were + + align:start position:0% +tails if we know how many heads were + + + align:start position:0% +tails if we know how many heads were +flipped we can calculate the number of + + align:start position:0% +flipped we can calculate the number of + + + align:start position:0% +flipped we can calculate the number of +Tails flipped so we only have one degree + + align:start position:0% +Tails flipped so we only have one degree + + + align:start position:0% +Tails flipped so we only have one degree +of + + align:start position:0% +of + + + align:start position:0% +of +Freedom let's refer to the kai Square + + align:start position:0% +Freedom let's refer to the kai Square + + + align:start position:0% +Freedom let's refer to the kai Square +distribution tions for one degree of + + align:start position:0% +distribution tions for one degree of + + + align:start position:0% +distribution tions for one degree of +Freedom we can compare our test + + align:start position:0% +Freedom we can compare our test + + + align:start position:0% +Freedom we can compare our test +statistic to the distribution to see if + + align:start position:0% +statistic to the distribution to see if + + + align:start position:0% +statistic to the distribution to see if +we have support for our n hypothesis or + + align:start position:0% +we have support for our n hypothesis or + + + align:start position:0% +we have support for our n hypothesis or +if we need to reject + + align:start position:0% +if we need to reject + + + align:start position:0% +if we need to reject +it what will our Criterion for support + + align:start position:0% +it what will our Criterion for support + + + align:start position:0% +it what will our Criterion for support +or rejection of our null hypothesis + + align:start position:0% +or rejection of our null hypothesis + + + align:start position:0% +or rejection of our null hypothesis +be while this is a fairly arbitrary + + align:start position:0% +be while this is a fairly arbitrary + + + align:start position:0% +be while this is a fairly arbitrary +choice in many fields a result result is + + align:start position:0% +choice in many fields a result result is + + + align:start position:0% +choice in many fields a result result is +said not to differ significantly from + + align:start position:0% +said not to differ significantly from + + + align:start position:0% +said not to differ significantly from +expectations if it has a one in 20 + + align:start position:0% +expectations if it has a one in 20 + + + align:start position:0% +expectations if it has a one in 20 +chance of + + align:start position:0% +chance of + + + align:start position:0% +chance of +happening in other words if the + + align:start position:0% +happening in other words if the + + + align:start position:0% +happening in other words if the +difference between the observed result + + align:start position:0% +difference between the observed result + + + align:start position:0% +difference between the observed result +and the expected result is small enough + + align:start position:0% +and the expected result is small enough + + + align:start position:0% +and the expected result is small enough +we would expect to see it one in 20 + + align:start position:0% +we would expect to see it one in 20 + + + align:start position:0% +we would expect to see it one in 20 +times which is a probability of + + align:start position:0% + + + + align:start position:0% + +0.05 this probability is called called + + align:start position:0% +0.05 this probability is called called + + + align:start position:0% +0.05 this probability is called called +the level of + + align:start position:0% +the level of + + + align:start position:0% +the level of +significance if a Kai Square value has a + + align:start position:0% +significance if a Kai Square value has a + + + align:start position:0% +significance if a Kai Square value has a +probability of occurring that is greater + + align:start position:0% +probability of occurring that is greater + + + align:start position:0% +probability of occurring that is greater +than our level of significance it lends + + align:start position:0% +than our level of significance it lends + + + align:start position:0% +than our level of significance it lends +support to our null + + align:start position:0% +support to our null + + + align:start position:0% +support to our null +hypothesis if a Kai Square value has a + + align:start position:0% +hypothesis if a Kai Square value has a + + + align:start position:0% +hypothesis if a Kai Square value has a +probability of occurring that is less + + align:start position:0% +probability of occurring that is less + + + align:start position:0% +probability of occurring that is less +than our level of significance we should + + align:start position:0% +than our level of significance we should + + + align:start position:0% +than our level of significance we should +reject the null + + align:start position:0% +reject the null + + + align:start position:0% +reject the null +hypothesis using the kai Square + + align:start position:0% +hypothesis using the kai Square + + + align:start position:0% +hypothesis using the kai Square +distribution for one degree of Freedom a + + align:start position:0% +distribution for one degree of Freedom a + + + align:start position:0% +distribution for one degree of Freedom a +Kai Square value of + + align:start position:0% +Kai Square value of + + + align:start position:0% +Kai Square value of +2.56 has greater than the 5% probability + + align:start position:0% +2.56 has greater than the 5% probability + + + align:start position:0% +2.56 has greater than the 5% probability +of occurring that we have set as our + + align:start position:0% +of occurring that we have set as our + + + align:start position:0% +of occurring that we have set as our +minimum this means that we fail to + + align:start position:0% +minimum this means that we fail to + + + align:start position:0% +minimum this means that we fail to +reject our null + + align:start position:0% +reject our null + + + align:start position:0% +reject our null +hypothesis in other words what we + + align:start position:0% +hypothesis in other words what we + + + align:start position:0% +hypothesis in other words what we +observe is close enough to what we + + align:start position:0% +observe is close enough to what we + + + align:start position:0% +observe is close enough to what we +expect that we have confidence that our + + align:start position:0% +expect that we have confidence that our + + + align:start position:0% +expect that we have confidence that our +coin is + + align:start position:0% + + + + align:start position:0% + +fair + + align:start position:0% +fair + + + align:start position:0% +fair +now suppose you're planning an + + align:start position:0% +now suppose you're planning an + + + align:start position:0% +now suppose you're planning an +experiment where you will cross mutant + + align:start position:0% +experiment where you will cross mutant + + + align:start position:0% +experiment where you will cross mutant +flies that are heterozygous for a + + align:start position:0% +flies that are heterozygous for a + + + align:start position:0% +flies that are heterozygous for a +wingless phenotype to each + + align:start position:0% +wingless phenotype to each + + + align:start position:0% +wingless phenotype to each +other the wingless phenotype is dominant + + align:start position:0% +other the wingless phenotype is dominant + + + align:start position:0% +other the wingless phenotype is dominant +relative to the wild type winged + + align:start position:0% +relative to the wild type winged + + + align:start position:0% +relative to the wild type winged +phenotype let's use the notation Big G + + align:start position:0% +phenotype let's use the notation Big G + + + align:start position:0% +phenotype let's use the notation Big G +little G for the genotype of the parent + + align:start position:0% +little G for the genotype of the parent + + + align:start position:0% +little G for the genotype of the parent +mutant + + align:start position:0% +mutant + + + align:start position:0% +mutant +flies in this case the F typee winged + + align:start position:0% +flies in this case the F typee winged + + + align:start position:0% +flies in this case the F typee winged +flies are homozygous + + align:start position:0% +flies are homozygous + + + align:start position:0% +flies are homozygous +recessive what percentage of flies + + align:start position:0% +recessive what percentage of flies + + + align:start position:0% +recessive what percentage of flies +resulting from a cross of two heterosis + + align:start position:0% +resulting from a cross of two heterosis + + + align:start position:0% +resulting from a cross of two heterosis +wingless mutants would you expect to be + + align:start position:0% +wingless mutants would you expect to be + + + align:start position:0% +wingless mutants would you expect to be +wild type versus mutant pause the video + + align:start position:0% +wild type versus mutant pause the video + + + align:start position:0% +wild type versus mutant pause the video +here and use a punet square to justify + + align:start position:0% +here and use a punet square to justify + + + align:start position:0% +here and use a punet square to justify +your + + align:start position:0% + + + + align:start position:0% + +answer + + align:start position:0% +answer + + + align:start position:0% +answer +performing this cross using a punet + + align:start position:0% +performing this cross using a punet + + + align:start position:0% +performing this cross using a punet +square you would expect a 3:1 ratio of + + align:start position:0% +square you would expect a 3:1 ratio of + + + align:start position:0% +square you would expect a 3:1 ratio of +mutant to Wild type + + align:start position:0% +mutant to Wild type + + + align:start position:0% +mutant to Wild type +flies you perform the cross with the + + align:start position:0% +flies you perform the cross with the + + + align:start position:0% +flies you perform the cross with the +parental mutant flies the cross produces + + align:start position:0% +parental mutant flies the cross produces + + + align:start position:0% +parental mutant flies the cross produces +50 progyny 32 are mutant and 18 are wild + + align:start position:0% +50 progyny 32 are mutant and 18 are wild + + + align:start position:0% +50 progyny 32 are mutant and 18 are wild +type so only 64% of our flies are mutant + + align:start position:0% +type so only 64% of our flies are mutant + + + align:start position:0% +type so only 64% of our flies are mutant +even though you expected + + align:start position:0% +even though you expected + + + align:start position:0% +even though you expected +75% of them to be + + align:start position:0% +75% of them to be + + + align:start position:0% +75% of them to be +mutant although it is not what you + + align:start position:0% +mutant although it is not what you + + + align:start position:0% +mutant although it is not what you +expected it doesn't seem that far off + + align:start position:0% +expected it doesn't seem that far off + + + align:start position:0% +expected it doesn't seem that far off +either you decide to continue mating + + align:start position:0% +either you decide to continue mating + + + align:start position:0% +either you decide to continue mating +your parental mutant flies until you + + align:start position:0% +your parental mutant flies until you + + + align:start position:0% +your parental mutant flies until you +have a th + + align:start position:0% +have a th + + + align:start position:0% +have a th +progyny surely with this large a sample + + align:start position:0% +progyny surely with this large a sample + + + align:start position:0% +progyny surely with this large a sample +size the ratio of mutant to Wild type + + align:start position:0% +size the ratio of mutant to Wild type + + + align:start position:0% +size the ratio of mutant to Wild type +flies will be closer to what you + + align:start position:0% +flies will be closer to what you + + + align:start position:0% +flies will be closer to what you +expect voila oh wait a minute even with + + align:start position:0% +expect voila oh wait a minute even with + + + align:start position:0% +expect voila oh wait a minute even with +a thousand progyny our experiments still + + align:start position:0% +a thousand progyny our experiments still + + + align:start position:0% +a thousand progyny our experiments still +produce 68% mutant and 32% wild type + + align:start position:0% +produce 68% mutant and 32% wild type + + + align:start position:0% +produce 68% mutant and 32% wild type +flies now you're really starting to + + align:start position:0% +flies now you're really starting to + + + align:start position:0% +flies now you're really starting to +wonder if you can call the results close + + align:start position:0% +wonder if you can call the results close + + + align:start position:0% +wonder if you can call the results close +enough to the expected + + align:start position:0% +enough to the expected + + + align:start position:0% +enough to the expected +outcome we can use the kai Square test + + align:start position:0% +outcome we can use the kai Square test + + + align:start position:0% +outcome we can use the kai Square test +to evaluate whether the sample that had + + align:start position:0% +to evaluate whether the sample that had + + + align:start position:0% +to evaluate whether the sample that had +is 68 to 32 ratio could have come from + + align:start position:0% +is 68 to 32 ratio could have come from + + + align:start position:0% +is 68 to 32 ratio could have come from +the 3:1 population distribution that we + + align:start position:0% +the 3:1 population distribution that we + + + align:start position:0% +the 3:1 population distribution that we +expected pause the video here calculate + + align:start position:0% +expected pause the video here calculate + + + align:start position:0% +expected pause the video here calculate +the Ki Square test statistic and + + align:start position:0% +the Ki Square test statistic and + + + align:start position:0% +the Ki Square test statistic and +determine the degrees of freedom in your + + align:start position:0% + + + + align:start position:0% + +data you should have obtained + + align:start position:0% +data you should have obtained + + + align:start position:0% +data you should have obtained +29.2 for your Kai Square + + align:start position:0% +29.2 for your Kai Square + + + align:start position:0% +29.2 for your Kai Square +value + + align:start position:0% +value + + + align:start position:0% +value +because there are only two phenotypic + + align:start position:0% +because there are only two phenotypic + + + align:start position:0% +because there are only two phenotypic +outcomes for your cross there is only + + align:start position:0% +outcomes for your cross there is only + + + align:start position:0% +outcomes for your cross there is only +one degree of Freedom any fly that isn't + + align:start position:0% +one degree of Freedom any fly that isn't + + + align:start position:0% +one degree of Freedom any fly that isn't +a mutant is wild type and vice + + align:start position:0% +a mutant is wild type and vice + + + align:start position:0% +a mutant is wild type and vice +versa the Ki Square distribution can + + align:start position:0% +versa the Ki Square distribution can + + + align:start position:0% +versa the Ki Square distribution can +also be presented in tabular + + align:start position:0% +also be presented in tabular + + + align:start position:0% +also be presented in tabular +form if you look at this table our + + align:start position:0% +form if you look at this table our + + + align:start position:0% +form if you look at this table our +experiment with one degree of freedom + + align:start position:0% +experiment with one degree of freedom + + + align:start position:0% +experiment with one degree of freedom +and a Kai Square value of 29 .2 + + align:start position:0% +and a Kai Square value of 29 .2 + + + align:start position:0% +and a Kai Square value of 29 .2 +corresponds to a probability that is + + align:start position:0% +corresponds to a probability that is + + + align:start position:0% +corresponds to a probability that is +much smaller than + + align:start position:0% + + + + align:start position:0% + +0.05 do you have support for the null + + align:start position:0% +0.05 do you have support for the null + + + align:start position:0% +0.05 do you have support for the null +hypothesis or should you reject + + align:start position:0% +hypothesis or should you reject + + + align:start position:0% +hypothesis or should you reject +it pause the video here and take a + + align:start position:0% +it pause the video here and take a + + + align:start position:0% +it pause the video here and take a +moment to think about + + align:start position:0% + + + + align:start position:0% + +it because the ratio of progyny the you + + align:start position:0% +it because the ratio of progyny the you + + + align:start position:0% +it because the ratio of progyny the you +obtained in your experiment has a + + align:start position:0% +obtained in your experiment has a + + + align:start position:0% +obtained in your experiment has a +probability of happening that is less + + align:start position:0% +probability of happening that is less + + + align:start position:0% +probability of happening that is less +than our level of significance you + + align:start position:0% +than our level of significance you + + + align:start position:0% +than our level of significance you +should reject our null + + align:start position:0% +should reject our null + + + align:start position:0% +should reject our null +hypothesis this indicates that our + + align:start position:0% +hypothesis this indicates that our + + + align:start position:0% +hypothesis this indicates that our +discrepant results are due to something + + align:start position:0% +discrepant results are due to something + + + align:start position:0% +discrepant results are due to something +more than just random + + align:start position:0% +more than just random + + + align:start position:0% +more than just random +chance a multitude of other factors + + align:start position:0% +chance a multitude of other factors + + + align:start position:0% +chance a multitude of other factors +could be contributing to our results for + + align:start position:0% +could be contributing to our results for + + + align:start position:0% +could be contributing to our results for +example there might be interactions with + + align:start position:0% +example there might be interactions with + + + align:start position:0% +example there might be interactions with +other genes that you are not aware of or + + align:start position:0% +other genes that you are not aware of or + + + align:start position:0% +other genes that you are not aware of or +environmental factors could be playing a + + align:start position:0% +environmental factors could be playing a + + + align:start position:0% +environmental factors could be playing a +role all we know is there are null + + align:start position:0% +role all we know is there are null + + + align:start position:0% +role all we know is there are null +hypothesis of a 3:1 ratio of mutant to + + align:start position:0% +hypothesis of a 3:1 ratio of mutant to + + + align:start position:0% +hypothesis of a 3:1 ratio of mutant to +Wild type flies is + + align:start position:0% +Wild type flies is + + + align:start position:0% +Wild type flies is +incorrect as a Next Step you decide to + + align:start position:0% +incorrect as a Next Step you decide to + + + align:start position:0% +incorrect as a Next Step you decide to +go back and review your notes to see if + + align:start position:0% +go back and review your notes to see if + + + align:start position:0% +go back and review your notes to see if +you can formulate another plausible + + align:start position:0% +you can formulate another plausible + + + align:start position:0% +you can formulate another plausible +hypothesis reviewing your punet Square + + align:start position:0% +hypothesis reviewing your punet Square + + + align:start position:0% +hypothesis reviewing your punet Square +you expected to obtain this genotypic + + align:start position:0% +you expected to obtain this genotypic + + + align:start position:0% +you expected to obtain this genotypic +ratio in the F1 progeny if you were to + + align:start position:0% +ratio in the F1 progeny if you were to + + + align:start position:0% +ratio in the F1 progeny if you were to +select a big G Big G mutant from the F1 + + align:start position:0% +select a big G Big G mutant from the F1 + + + align:start position:0% +select a big G Big G mutant from the F1 +progeny and cross it with a little G + + align:start position:0% +progeny and cross it with a little G + + + align:start position:0% +progeny and cross it with a little G +little G wild type fly you would expect + + align:start position:0% +little G wild type fly you would expect + + + align:start position:0% +little G wild type fly you would expect +that all of the progyny will be + + align:start position:0% +that all of the progyny will be + + + align:start position:0% +that all of the progyny will be +mutants after attempting this cross with + + align:start position:0% +mutants after attempting this cross with + + + align:start position:0% +mutants after attempting this cross with +a variety of flies from the F1 progyny + + align:start position:0% +a variety of flies from the F1 progyny + + + align:start position:0% +a variety of flies from the F1 progyny +that have a mutant phenotype + + align:start position:0% +that have a mutant phenotype + + + align:start position:0% +that have a mutant phenotype +it becomes clear that you cannot find a + + align:start position:0% +it becomes clear that you cannot find a + + + align:start position:0% +it becomes clear that you cannot find a +mutant fly that when crossed with a wild + + align:start position:0% +mutant fly that when crossed with a wild + + + align:start position:0% +mutant fly that when crossed with a wild +type fly produces all mutant + + align:start position:0% +type fly produces all mutant + + + align:start position:0% +type fly produces all mutant +progyny somehow you keep selecting + + align:start position:0% +progyny somehow you keep selecting + + + align:start position:0% +progyny somehow you keep selecting +heteros + + align:start position:0% +heteros + + + align:start position:0% +heteros +mutants you begin to suspect that the F1 + + align:start position:0% +mutants you begin to suspect that the F1 + + + align:start position:0% +mutants you begin to suspect that the F1 +population does not contain the expected + + align:start position:0% +population does not contain the expected + + + align:start position:0% +population does not contain the expected +number of Big G Big G + + align:start position:0% +number of Big G Big G + + + align:start position:0% +number of Big G Big G +flies checking your lap no book you see + + align:start position:0% +flies checking your lap no book you see + + + align:start position:0% +flies checking your lap no book you see +a note about an observation that you + + align:start position:0% +a note about an observation that you + + + align:start position:0% +a note about an observation that you +barely paid attention to at the time + + align:start position:0% +barely paid attention to at the time + + + align:start position:0% +barely paid attention to at the time +when you made it the two parental mutant + + align:start position:0% +when you made it the two parental mutant + + + align:start position:0% +when you made it the two parental mutant +flies there were a number of dead + + align:start position:0% +flies there were a number of dead + + + align:start position:0% +flies there were a number of dead +embryos in your + + align:start position:0% +embryos in your + + + align:start position:0% +embryos in your +vial a new hypothesis is forming in your + + align:start position:0% +vial a new hypothesis is forming in your + + + align:start position:0% +vial a new hypothesis is forming in your +mind can you come up with a hypothesis + + align:start position:0% +mind can you come up with a hypothesis + + + align:start position:0% +mind can you come up with a hypothesis +that may explain the observations you + + align:start position:0% +that may explain the observations you + + + align:start position:0% +that may explain the observations you +have made through these + + align:start position:0% +have made through these + + + align:start position:0% +have made through these +experiments pause the video here + + align:start position:0% +experiments pause the video here + + + align:start position:0% +experiments pause the video here +discuss and justify your hypothesis with + + align:start position:0% +discuss and justify your hypothesis with + + + align:start position:0% +discuss and justify your hypothesis with +a + + align:start position:0% + + + + align:start position:0% + +classmate while there are many possible + + align:start position:0% +classmate while there are many possible + + + align:start position:0% +classmate while there are many possible +hypotheses one possible hypotheses is + + align:start position:0% +hypotheses one possible hypotheses is + + + align:start position:0% +hypotheses one possible hypotheses is +that the dead embryos in your vial were + + align:start position:0% +that the dead embryos in your vial were + + + align:start position:0% +that the dead embryos in your vial were +the missing Big G Big G + + align:start position:0% +the missing Big G Big G + + + align:start position:0% +the missing Big G Big G +mutants it may be that the wingless + + align:start position:0% +mutants it may be that the wingless + + + align:start position:0% +mutants it may be that the wingless +trait when homozygous results in + + align:start position:0% +trait when homozygous results in + + + align:start position:0% +trait when homozygous results in +lethality + + align:start position:0% + + + + align:start position:0% + +this will result in a phenotypic ratio + + align:start position:0% +this will result in a phenotypic ratio + + + align:start position:0% +this will result in a phenotypic ratio +of 2: one mutant to Wild type flies in + + align:start position:0% +of 2: one mutant to Wild type flies in + + + align:start position:0% +of 2: one mutant to Wild type flies in +the F1 + + align:start position:0% + + + + align:start position:0% + +progyny again you can use the K Square + + align:start position:0% +progyny again you can use the K Square + + + align:start position:0% +progyny again you can use the K Square +test for goodness of fit to test your + + align:start position:0% +test for goodness of fit to test your + + + align:start position:0% +test for goodness of fit to test your +new null + + align:start position:0% +new null + + + align:start position:0% +new null +hypothesis going back to your data of a + + align:start position:0% +hypothesis going back to your data of a + + + align:start position:0% +hypothesis going back to your data of a +thousand progyny use the test to + + align:start position:0% +thousand progyny use the test to + + + align:start position:0% +thousand progyny use the test to +evaluate the no + + align:start position:0% +evaluate the no + + + align:start position:0% +evaluate the no +hypothesis pause the + + align:start position:0% + + + + align:start position:0% + +video you should have obtained a Ki + + align:start position:0% +video you should have obtained a Ki + + + align:start position:0% +video you should have obtained a Ki +Square value of + + align:start position:0% +Square value of + + + align:start position:0% +Square value of +0.36 for one degree of Freedom you + + align:start position:0% +0.36 for one degree of Freedom you + + + align:start position:0% +0.36 for one degree of Freedom you +cannot reject your no + + align:start position:0% +cannot reject your no + + + align:start position:0% +cannot reject your no +hypothesis while you have support for + + align:start position:0% +hypothesis while you have support for + + + align:start position:0% +hypothesis while you have support for +your null hypothesis more experiments + + align:start position:0% +your null hypothesis more experiments + + + align:start position:0% +your null hypothesis more experiments +are needed to confirm the idea + + align:start position:0% +are needed to confirm the idea + + + align:start position:0% +are needed to confirm the idea +that the Big G Big G genotype is lethal + + align:start position:0% +that the Big G Big G genotype is lethal + + + align:start position:0% +that the Big G Big G genotype is lethal +as you + + align:start position:0% +as you + + + align:start position:0% +as you +suspect the results from our K Square + + align:start position:0% +suspect the results from our K Square + + + align:start position:0% +suspect the results from our K Square +test have led us to a reasonable next + + align:start position:0% +test have led us to a reasonable next + + + align:start position:0% +test have led us to a reasonable next +experiment to + + align:start position:0% + + + + align:start position:0% + +perform in this video you saw how the + + align:start position:0% +perform in this video you saw how the + + + align:start position:0% +perform in this video you saw how the +kai Square statistic can help us + + align:start position:0% +kai Square statistic can help us + + + align:start position:0% +kai Square statistic can help us +determine if our experimental genetic + + align:start position:0% +determine if our experimental genetic + + + align:start position:0% +determine if our experimental genetic +data came from the expected population + + align:start position:0% +data came from the expected population + + + align:start position:0% +data came from the expected population +this + + align:start position:0% +this + + + align:start position:0% +this +distribution comparing observed values + + align:start position:0% +distribution comparing observed values + + + align:start position:0% +distribution comparing observed values +to expected values helped us determine + + align:start position:0% +to expected values helped us determine + + + align:start position:0% +to expected values helped us determine +if deviations in our data could be + + align:start position:0% +if deviations in our data could be + + + align:start position:0% +if deviations in our data could be +explained by random chance or if a + + align:start position:0% +explained by random chance or if a + + + align:start position:0% +explained by random chance or if a +hypothesis needed + + align:start position:0% +hypothesis needed + + + align:start position:0% +hypothesis needed +revision the Ki Square test for goodness + + align:start position:0% +revision the Ki Square test for goodness + + + align:start position:0% +revision the Ki Square test for goodness +of fit is just one statistical test of + + align:start position:0% +of fit is just one statistical test of + + + align:start position:0% +of fit is just one statistical test of +many that allows us to determine how + + align:start position:0% +many that allows us to determine how + + + align:start position:0% +many that allows us to determine how +confident we are that a sample of data + + align:start position:0% +confident we are that a sample of data + + + align:start position:0% +confident we are that a sample of data +comes from a population with a certain + + align:start position:0% +comes from a population with a certain + + + align:start position:0% +comes from a population with a certain +distribution it is important to + + align:start position:0% +distribution it is important to + + + align:start position:0% +distribution it is important to +understand what these tests mean and how + + align:start position:0% +understand what these tests mean and how + + + align:start position:0% +understand what these tests mean and how +to interpret their results so that you + + align:start position:0% +to interpret their results so that you + + + align:start position:0% +to interpret their results so that you +know their limitations and can make + + align:start position:0% +know their limitations and can make + + + align:start position:0% +know their limitations and can make +inform + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +decisions \ No newline at end of file diff --git a/-Km2237G0P8.txt b/-Km2237G0P8.txt new file mode 100644 index 0000000000000000000000000000000000000000..00381adf2664fef099791692ba56cd4b6aaaa631 --- /dev/null +++ b/-Km2237G0P8.txt @@ -0,0 +1,491 @@ +align:start position:0% + +assessing student work uh as a team um + + align:start position:0% +assessing student work uh as a team um + + + align:start position:0% +assessing student work uh as a team um +has different challenges of of course + + align:start position:0% +has different challenges of of course + + + align:start position:0% +has different challenges of of course +the first thing you do is assess the + + align:start position:0% +the first thing you do is assess the + + + align:start position:0% +the first thing you do is assess the +output of the team's work uh whether + + align:start position:0% +output of the team's work uh whether + + + align:start position:0% +output of the team's work uh whether +that's a requirement set whether it's a + + align:start position:0% +that's a requirement set whether it's a + + + align:start position:0% +that's a requirement set whether it's a +set of initial Concepts whether it's a + + align:start position:0% +set of initial Concepts whether it's a + + + align:start position:0% +set of initial Concepts whether it's a +presentation that's given at a + + align:start position:0% +presentation that's given at a + + + align:start position:0% +presentation that's given at a +preliminary design review uh whether + + align:start position:0% +preliminary design review uh whether + + + align:start position:0% +preliminary design review uh whether +it's a physical prototype that they + + align:start position:0% +it's a physical prototype that they + + + align:start position:0% +it's a physical prototype that they +present as as a team um so that always + + align:start position:0% +present as as a team um so that always + + + align:start position:0% +present as as a team um so that always +should be the first um thing that is + + align:start position:0% +should be the first um thing that is + + + align:start position:0% +should be the first um thing that is +assessed is what is the net output that + + align:start position:0% +assessed is what is the net output that + + + align:start position:0% +assessed is what is the net output that +that the team has produced um within + + align:start position:0% +that the team has produced um within + + + align:start position:0% +that the team has produced um within +that uh it is not always easy to discern + + align:start position:0% +that uh it is not always easy to discern + + + align:start position:0% +that uh it is not always easy to discern +what has been the individual + + align:start position:0% +what has been the individual + + + align:start position:0% +what has been the individual +contribution since the the whole purpose + + align:start position:0% +contribution since the the whole purpose + + + align:start position:0% +contribution since the the whole purpose +of a team is that you know the the sum + + align:start position:0% +of a team is that you know the the sum + + + align:start position:0% +of a team is that you know the the sum +that comes out is greater than the + + align:start position:0% +that comes out is greater than the + + + align:start position:0% +that comes out is greater than the +individual parts so in the best + + align:start position:0% +individual parts so in the best + + + align:start position:0% +individual parts so in the best +functioning teams there's a magic that + + align:start position:0% +functioning teams there's a magic that + + + align:start position:0% +functioning teams there's a magic that +happens there there's a Synergy that + + align:start position:0% +happens there there's a Synergy that + + + align:start position:0% +happens there there's a Synergy that +happens there's an output that's only + + align:start position:0% +happens there's an output that's only + + + align:start position:0% +happens there's an output that's only +produced by these synergistic + + align:start position:0% +produced by these synergistic + + + align:start position:0% +produced by these synergistic +interactions of all the team members in + + align:start position:0% +interactions of all the team members in + + + align:start position:0% +interactions of all the team members in +in a sense + + align:start position:0% +in a sense + + + align:start position:0% +in a sense +um trying to dissect you know what's the + + align:start position:0% +um trying to dissect you know what's the + + + align:start position:0% +um trying to dissect you know what's the +individual piece that everybody did is + + align:start position:0% +individual piece that everybody did is + + + align:start position:0% +individual piece that everybody did is +counter this idea of Team Synergy that + + align:start position:0% +counter this idea of Team Synergy that + + + align:start position:0% +counter this idea of Team Synergy that +being said we also need to um assess + + align:start position:0% +being said we also need to um assess + + + align:start position:0% +being said we also need to um assess +individually the contributions and the + + align:start position:0% +individually the contributions and the + + + align:start position:0% +individually the contributions and the +learnings of students and we do this + + align:start position:0% +learnings of students and we do this + + + align:start position:0% +learnings of students and we do this +through a couple of mechanisms for + + align:start position:0% +through a couple of mechanisms for + + + align:start position:0% +through a couple of mechanisms for +example a peer review uh so you can do a + + align:start position:0% +example a peer review uh so you can do a + + + align:start position:0% +example a peer review uh so you can do a +peer review process uh it's trickier in + + align:start position:0% +peer review process uh it's trickier in + + + align:start position:0% +peer review process uh it's trickier in +smaller teams than in larger teams but + + align:start position:0% +smaller teams than in larger teams but + + + align:start position:0% +smaller teams than in larger teams but +um if it's done properly peer review can + + align:start position:0% +um if it's done properly peer review can + + + align:start position:0% +um if it's done properly peer review can +be very effective in in not only helping + + align:start position:0% +be very effective in in not only helping + + + align:start position:0% +be very effective in in not only helping +one understand you know who who um who + + align:start position:0% +one understand you know who who um who + + + align:start position:0% +one understand you know who who um who +are the + + align:start position:0% +are the + + + align:start position:0% +are the +contributors and who are the Free Riders + + align:start position:0% +contributors and who are the Free Riders + + + align:start position:0% +contributors and who are the Free Riders +this is always a big issue in teams is + + align:start position:0% +this is always a big issue in teams is + + + align:start position:0% +this is always a big issue in teams is +that the free riter syndrome where uh + + align:start position:0% +that the free riter syndrome where uh + + + align:start position:0% +that the free riter syndrome where uh +some team members contribute + + align:start position:0% +some team members contribute + + + align:start position:0% +some team members contribute +significantly less than others and this + + align:start position:0% +significantly less than others and this + + + align:start position:0% +significantly less than others and this +is often The Source can be a source of + + align:start position:0% +is often The Source can be a source of + + + align:start position:0% +is often The Source can be a source of +conflict + + align:start position:0% +conflict + + + align:start position:0% +conflict +and so understanding this is important + + align:start position:0% +and so understanding this is important + + + align:start position:0% +and so understanding this is important +but also having other mechanisms in the + + align:start position:0% +but also having other mechanisms in the + + + align:start position:0% +but also having other mechanisms in the +class such as an individual final exam + + align:start position:0% +class such as an individual final exam + + + align:start position:0% +class such as an individual final exam +and then the other uh written exam which + + align:start position:0% +and then the other uh written exam which + + + align:start position:0% +and then the other uh written exam which +is administered online and the other + + align:start position:0% +is administered online and the other + + + align:start position:0% +is administered online and the other +thing we started doing is oral exams + + align:start position:0% +thing we started doing is oral exams + + + align:start position:0% +thing we started doing is oral exams +which seems oldfashioned but I have to + + align:start position:0% +which seems oldfashioned but I have to + + + align:start position:0% +which seems oldfashioned but I have to +tell you in 15 to 20 minutes of a + + align:start position:0% +tell you in 15 to 20 minutes of a + + + align:start position:0% +tell you in 15 to 20 minutes of a +one-on-one conversation with a student + + align:start position:0% +one-on-one conversation with a student + + + align:start position:0% +one-on-one conversation with a student +at the end of the class you really learn + + align:start position:0% +at the end of the class you really learn + + + align:start position:0% +at the end of the class you really learn +a lot you learn a lot about what they've + + align:start position:0% +a lot you learn a lot about what they've + + + align:start position:0% +a lot you learn a lot about what they've +learned uh where they may still have + + align:start position:0% +learned uh where they may still have + + + align:start position:0% +learned uh where they may still have +confusion or misconceptions and also the + + align:start position:0% +confusion or misconceptions and also the + + + align:start position:0% +confusion or misconceptions and also the +feedback that they give you so I highly + + align:start position:0% +feedback that they give you so I highly + + + align:start position:0% +feedback that they give you so I highly +recommend to do oral exams if it's + + align:start position:0% +recommend to do oral exams if it's + + + align:start position:0% +recommend to do oral exams if it's +possible \ No newline at end of file diff --git a/0su7rM_7_DM.txt b/0su7rM_7_DM.txt new file mode 100644 index 0000000000000000000000000000000000000000..78824eea273b85097eb25c37f49dff3f167975a7 --- /dev/null +++ b/0su7rM_7_DM.txt @@ -0,0 +1,9797 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit MIT opencourseware + + align:start position:0% +of MIT courses visit MIT opencourseware + + + align:start position:0% +of MIT courses visit MIT opencourseware +at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu you'll recall the last class + + align:start position:0% +ocw.mit.edu you'll recall the last class + + + align:start position:0% +ocw.mit.edu you'll recall the last class +was the third + + align:start position:0% +was the third + + + align:start position:0% +was the third +of conception models this one dealing + + align:start position:0% +of conception models this one dealing + + + align:start position:0% +of conception models this one dealing +with the organic shape of Nature and its + + align:start position:0% +with the organic shape of Nature and its + + + align:start position:0% +with the organic shape of Nature and its +replication + + align:start position:0% +replication + + + align:start position:0% +replication +in patterning of + + align:start position:0% +in patterning of + + + align:start position:0% +in patterning of +cities we focused + + align:start position:0% +cities we focused + + + align:start position:0% +cities we focused +on a number of + + align:start position:0% +on a number of + + + align:start position:0% +on a number of +examples one of which + + align:start position:0% +examples one of which + + + align:start position:0% +examples one of which +was uh the work of Patrick GES the + + align:start position:0% +was uh the work of Patrick GES the + + + align:start position:0% +was uh the work of Patrick GES the +second one was the work of ebena Harden + + align:start position:0% +second one was the work of ebena Harden + + + align:start position:0% +second one was the work of ebena Harden +the Garden City movement the third was + + align:start position:0% +the Garden City movement the third was + + + align:start position:0% +the Garden City movement the third was +the work of Claren Stein and hry Wright + + align:start position:0% +the work of Claren Stein and hry Wright + + + align:start position:0% +the work of Claren Stein and hry Wright +in the United + + align:start position:0% +in the United + + + align:start position:0% +in the United +States and + + align:start position:0% +States and + + + align:start position:0% +States and +the and then I did a short run through + + align:start position:0% +the and then I did a short run through + + + align:start position:0% +the and then I did a short run through +of uh a piece that I wrote last year for + + align:start position:0% +of uh a piece that I wrote last year for + + + align:start position:0% +of uh a piece that I wrote last year for +conference in Athens on nature and the + + align:start position:0% +conference in Athens on nature and the + + + align:start position:0% +conference in Athens on nature and the +city in which I argued that there was + + align:start position:0% +city in which I argued that there was + + + align:start position:0% +city in which I argued that there was +the most dynamic thing about cities is + + align:start position:0% +the most dynamic thing about cities is + + + align:start position:0% +the most dynamic thing about cities is +it's it's is our human capacity to learn + + align:start position:0% +it's it's is our human capacity to learn + + + align:start position:0% +it's it's is our human capacity to learn +and to adapt to change and I try to show + + align:start position:0% +and to adapt to change and I try to show + + + align:start position:0% +and to adapt to change and I try to show +that + + align:start position:0% +that + + + align:start position:0% +that +uh that in the life + + align:start position:0% +uh that in the life + + + align:start position:0% +uh that in the life +of 70 years of + + align:start position:0% +of 70 years of + + + align:start position:0% +of 70 years of +the Tennessee Valley + + align:start position:0% +the Tennessee Valley + + + align:start position:0% +the Tennessee Valley +Authority the capacity to change the + + align:start position:0% +Authority the capacity to change the + + + align:start position:0% +Authority the capacity to change the +perspective about what + + align:start position:0% +perspective about what + + + align:start position:0% +perspective about what +nature + + align:start position:0% +nature + + + align:start position:0% +nature +is uh nature is no static phenomenon + + align:start position:0% +is uh nature is no static phenomenon + + + align:start position:0% +is uh nature is no static phenomenon +it's uh it's a pro it's a learning of + + align:start position:0% +it's uh it's a pro it's a learning of + + + align:start position:0% +it's uh it's a pro it's a learning of +patterns as previously identified in + + align:start position:0% +patterns as previously identified in + + + align:start position:0% +patterns as previously identified in +organic systems + + align:start position:0% + + + + align:start position:0% + +selectively so it's requires the human + + align:start position:0% +selectively so it's requires the human + + + align:start position:0% +selectively so it's requires the human +brain and + + align:start position:0% + + + + align:start position:0% + +uh the Tennessee Valley Authority built + + align:start position:0% +uh the Tennessee Valley Authority built + + + align:start position:0% +uh the Tennessee Valley Authority built +28 Dam + + align:start position:0% +28 Dam + + + align:start position:0% +28 Dam +on the concept that dams that water + + align:start position:0% +on the concept that dams that water + + + align:start position:0% +on the concept that dams that water +power was more + + align:start position:0% +power was more + + + align:start position:0% +power was more +hygienic and would be sufficient for + + align:start position:0% +hygienic and would be sufficient for + + + align:start position:0% +hygienic and would be sufficient for +creating a new industrial Zone in the + + align:start position:0% +creating a new industrial Zone in the + + + align:start position:0% +creating a new industrial Zone in the +eight states of this of the Tennessee + + align:start position:0% +eight states of this of the Tennessee + + + align:start position:0% +eight states of this of the Tennessee +Valley 65% of the power now is not + + align:start position:0% +Valley 65% of the power now is not + + + align:start position:0% +Valley 65% of the power now is not +generated by + + align:start position:0% +generated by + + + align:start position:0% +generated by +water the prediction of the economic + + align:start position:0% +water the prediction of the economic + + + align:start position:0% +water the prediction of the economic +growth in this region is was very low + + align:start position:0% +growth in this region is was very low + + + align:start position:0% +growth in this region is was very low +also the capacity of the water to + + align:start position:0% +also the capacity of the water to + + + align:start position:0% +also the capacity of the water to +produce enough energy was low + + align:start position:0% +produce enough energy was low + + + align:start position:0% +produce enough energy was low +so what happened + + align:start position:0% +so what happened + + + align:start position:0% +so what happened +coal became the substitute coal led to + + align:start position:0% +coal became the substitute coal led to + + + align:start position:0% +coal became the substitute coal led to +strip mining which is as + + align:start position:0% +strip mining which is as + + + align:start position:0% +strip mining which is as +anti-natural phenomenon as you can + + align:start position:0% +anti-natural phenomenon as you can + + + align:start position:0% +anti-natural phenomenon as you can +imagine the largest environmental + + align:start position:0% +imagine the largest environmental + + + align:start position:0% +imagine the largest environmental +disaster in the United States happened + + align:start position:0% +disaster in the United States happened + + + align:start position:0% +disaster in the United States happened +in the Cal spill from one of the coal + + align:start position:0% +in the Cal spill from one of the coal + + + align:start position:0% +in the Cal spill from one of the coal +generating plants + + align:start position:0% + + + + align:start position:0% + +and so on and so on and we went through + + align:start position:0% +and so on and so on and we went through + + + align:start position:0% +and so on and so on and we went through +uh an argument which suggests that + + align:start position:0% +uh an argument which suggests that + + + align:start position:0% +uh an argument which suggests that +nature is still a phenomenon which is + + align:start position:0% +nature is still a phenomenon which is + + + align:start position:0% +nature is still a phenomenon which is +understood through the process of the + + align:start position:0% +understood through the process of the + + + align:start position:0% +understood through the process of the +human + + align:start position:0% +human + + + align:start position:0% +human +brain there's no absolute + + align:start position:0% +brain there's no absolute + + + align:start position:0% +brain there's no absolute +correctness of + + align:start position:0% + + + + align:start position:0% + +nature biomorphism is a foolish project + + align:start position:0% +nature biomorphism is a foolish project + + + align:start position:0% +nature biomorphism is a foolish project +by + + align:start position:0% +by + + + align:start position:0% +by +architects who should understand a much + + align:start position:0% +architects who should understand a much + + + align:start position:0% +architects who should understand a much +broader interpretation of history and + + align:start position:0% +broader interpretation of history and + + + align:start position:0% +broader interpretation of history and +culture than to select items from array + + align:start position:0% +culture than to select items from array + + + align:start position:0% +culture than to select items from array +of natural + + align:start position:0% +of natural + + + align:start position:0% +of natural +forms it's a purely a selection + + align:start position:0% +forms it's a purely a selection + + + align:start position:0% +forms it's a purely a selection +yes + + align:start position:0% +yes + + + align:start position:0% +yes +maybe we we have no + + align:start position:0% +maybe we we have no + + + align:start position:0% +maybe we we have no +measurement that people are more + + align:start position:0% +measurement that people are more + + + align:start position:0% +measurement that people are more +satisfied in a forest than in uh + + align:start position:0% + + + + align:start position:0% + +on Fifth Avenue New + + align:start position:0% +on Fifth Avenue New + + + align:start position:0% +on Fifth Avenue New +York we assume that to be true I suppose + + align:start position:0% +York we assume that to be true I suppose + + + align:start position:0% +York we assume that to be true I suppose +we could put we could ask people in a + + align:start position:0% +we could put we could ask people in a + + + align:start position:0% +we could put we could ask people in a +question + + align:start position:0% +question + + + align:start position:0% +question +there but Marx was right that the + + align:start position:0% +there but Marx was right that the + + + align:start position:0% +there but Marx was right that the +establishment of the first settlement + + align:start position:0% +establishment of the first settlement + + + align:start position:0% +establishment of the first settlement +set up a duality between country and + + align:start position:0% +set up a duality between country and + + + align:start position:0% +set up a duality between country and +city which is going to take a lot lot of + + align:start position:0% +city which is going to take a lot lot of + + + align:start position:0% +city which is going to take a lot lot of +time to resolve and it's still + + align:start position:0% +time to resolve and it's still + + + align:start position:0% +time to resolve and it's still +problematic what I've given you + + align:start position:0% +problematic what I've given you + + + align:start position:0% +problematic what I've given you +today + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +um are some functional descriptive + + align:start position:0% +um are some functional descriptive + + + align:start position:0% +um are some functional descriptive +theories borrowed mainly from the social + + align:start position:0% +theories borrowed mainly from the social + + + align:start position:0% +theories borrowed mainly from the social +sciences I will go through each of them + + align:start position:0% +sciences I will go through each of them + + + align:start position:0% +sciences I will go through each of them +with an example + + align:start position:0% +with an example + + + align:start position:0% +with an example +and discuss what the theory is and what + + align:start position:0% +and discuss what the theory is and what + + + align:start position:0% +and discuss what the theory is and what +it proposes what its weaknesses are this + + align:start position:0% +it proposes what its weaknesses are this + + + align:start position:0% +it proposes what its weaknesses are this +used to be a whole subject for a whole + + align:start position:0% +used to be a whole subject for a whole + + + align:start position:0% +used to be a whole subject for a whole +semester in City Planning education it's + + align:start position:0% +semester in City Planning education it's + + + align:start position:0% +semester in City Planning education it's +hardly dealt with now part of these are + + align:start position:0% +hardly dealt with now part of these are + + + align:start position:0% +hardly dealt with now part of these are +classical theories which no longer are + + align:start position:0% +classical theories which no longer are + + + align:start position:0% +classical theories which no longer are +interesting to anybody um the second + + align:start position:0% +interesting to anybody um the second + + + align:start position:0% +interesting to anybody um the second +page the first page deals with the + + align:start position:0% +page the first page deals with the + + + align:start position:0% +page the first page deals with the +application of one of the these theories + + align:start position:0% +application of one of the these theories + + + align:start position:0% +application of one of the these theories +ho to + + align:start position:0% +ho to + + + align:start position:0% +ho to +Atlanta you can see the sector theory in + + align:start position:0% + + + + align:start position:0% + +Atlanta indicating the location of High + + align:start position:0% +Atlanta indicating the location of High + + + align:start position:0% +Atlanta indicating the location of High +income white + + align:start position:0% +income white + + + align:start position:0% +income white +housing um as opposed to lwi income + + align:start position:0% +housing um as opposed to lwi income + + + align:start position:0% +housing um as opposed to lwi income +housing um following a model purported + + align:start position:0% +housing um following a model purported + + + align:start position:0% +housing um following a model purported +by H hoit in + + align:start position:0% +by H hoit in + + + align:start position:0% +by H hoit in + + align:start position:0% + + + align:start position:0% +the next page deals with uh examination + + align:start position:0% +the next page deals with uh examination + + + align:start position:0% +the next page deals with uh examination +of + + align:start position:0% +of + + + align:start position:0% +of +two figures in in Great Britain who + + align:start position:0% +two figures in in Great Britain who + + + align:start position:0% +two figures in in Great Britain who +lived more or less at the same time John + + align:start position:0% +lived more or less at the same time John + + + align:start position:0% +lived more or less at the same time John +Rus and + + align:start position:0% +Rus and + + + align:start position:0% +Rus and +the theorist of AR theorist of + + align:start position:0% +the theorist of AR theorist of + + + align:start position:0% +the theorist of AR theorist of +painting um and Fredick + + align:start position:0% +painting um and Fredick + + + align:start position:0% +painting um and Fredick +Engles um who we will discuss more fully + + align:start position:0% +Engles um who we will discuss more fully + + + align:start position:0% +Engles um who we will discuss more fully +in two weeks in a week's time uh uh one + + align:start position:0% +in two weeks in a week's time uh uh one + + + align:start position:0% +in two weeks in a week's time uh uh one +of the origins of the modern Communist + + align:start position:0% +of the origins of the modern Communist + + + align:start position:0% +of the origins of the modern Communist +Manifesto and + + align:start position:0% +Manifesto and + + + align:start position:0% +Manifesto and +uh in 1845 at the age of 25 he wrote one + + align:start position:0% +uh in 1845 at the age of 25 he wrote one + + + align:start position:0% +uh in 1845 at the age of 25 he wrote one +of the greatest books on urbanism ever + + align:start position:0% +of the greatest books on urbanism ever + + + align:start position:0% +of the greatest books on urbanism ever +written the condition of the working + + align:start position:0% +written the condition of the working + + + align:start position:0% +written the condition of the working +class in England which we will discuss + + align:start position:0% +class in England which we will discuss + + + align:start position:0% +class in England which we will discuss +when we talk about the origins the + + align:start position:0% +when we talk about the origins the + + + align:start position:0% +when we talk about the origins the +industrial city the next + + align:start position:0% +industrial city the next + + + align:start position:0% +industrial city the next +page is from a diagram by Mal Weber in a + + align:start position:0% +page is from a diagram by Mal Weber in a + + + align:start position:0% +page is from a diagram by Mal Weber in a +book called urban place and non-place + + align:start position:0% +book called urban place and non-place + + + align:start position:0% +book called urban place and non-place +urban realm this was + + align:start position:0% +urban realm this was + + + align:start position:0% +urban realm this was +a set of studies which is published in + + align:start position:0% +a set of studies which is published in + + + align:start position:0% +a set of studies which is published in +this book and in another book called + + align:start position:0% +this book and in another book called + + + align:start position:0% +this book and in another book called +City cities and space which deal with + + align:start position:0% +City cities and space which deal with + + + align:start position:0% +City cities and space which deal with +the Advent of a the interpretation of + + align:start position:0% +the Advent of a the interpretation of + + + align:start position:0% +the Advent of a the interpretation of +different systems of + + align:start position:0% +different systems of + + + align:start position:0% +different systems of +communication um interacting in one + + align:start position:0% +communication um interacting in one + + + align:start position:0% +communication um interacting in one +place these this this is + + align:start position:0% +place these this this is + + + align:start position:0% +place these this this is +an oppositional position to the + + align:start position:0% +an oppositional position to the + + + align:start position:0% +an oppositional position to the +conventional uh economic models uh or + + align:start position:0% +conventional uh economic models uh or + + + align:start position:0% +conventional uh economic models uh or +even physical models of + + align:start position:0% +even physical models of + + + align:start position:0% +even physical models of +interaction uh and an old model + + align:start position:0% +interaction uh and an old model + + + align:start position:0% +interaction uh and an old model +by + + align:start position:0% +by + + + align:start position:0% +by +uh a book called A Communications theory + + align:start position:0% +uh a book called A Communications theory + + + align:start position:0% +uh a book called A Communications theory +of urban growth looking at the + + align:start position:0% +of urban growth looking at the + + + align:start position:0% +of urban growth looking at the +measurement of + + align:start position:0% +measurement of + + + align:start position:0% +measurement of +intersections uh in complementary + + align:start position:0% +intersections uh in complementary + + + align:start position:0% +intersections uh in complementary +functions in spal + + align:start position:0% +functions in spal + + + align:start position:0% +functions in spal +form and the + + align:start position:0% + + + + align:start position:0% + +last this the next + + align:start position:0% + + + + align:start position:0% + +page is from economic + + align:start position:0% +page is from economic + + + align:start position:0% +page is from economic +geography and + + align:start position:0% +geography and + + + align:start position:0% +geography and +represents population potential + + align:start position:0% + + + + align:start position:0% + +diagrams and then next we'll finish with + + align:start position:0% +diagrams and then next we'll finish with + + + align:start position:0% +diagrams and then next we'll finish with +cont a very recent piece from The New + + align:start position:0% +cont a very recent piece from The New + + + align:start position:0% +cont a very recent piece from The New +York + + align:start position:0% +York + + + align:start position:0% +York +Times uh in which a physicist solves the + + align:start position:0% +Times uh in which a physicist solves the + + + align:start position:0% +Times uh in which a physicist solves the +city + + align:start position:0% +city + + + align:start position:0% +city +uh this is hopefully what we will finish + + align:start position:0% +uh this is hopefully what we will finish + + + align:start position:0% +uh this is hopefully what we will finish +with the question is does it really make + + align:start position:0% +with the question is does it really make + + + align:start position:0% +with the question is does it really make +any sense at + + align:start position:0% +any sense at + + + align:start position:0% +any sense at +all but we'll look at the work + + align:start position:0% +all but we'll look at the work + + + align:start position:0% +all but we'll look at the work +of these people dealing with models of + + align:start position:0% +of these people dealing with models of + + + align:start position:0% +of these people dealing with models of +complex Theory at the + + align:start position:0% +complex Theory at the + + + align:start position:0% +complex Theory at the +moment the first let's go through these + + align:start position:0% +moment the first let's go through these + + + align:start position:0% +moment the first let's go through these +very quickly + + align:start position:0% +very quickly + + + align:start position:0% +very quickly +the + + align:start position:0% +the + + + align:start position:0% +the +first by the way these breakdowns were + + align:start position:0% +first by the way these breakdowns were + + + align:start position:0% +first by the way these breakdowns were +created in this class with Kevin Lynch + + align:start position:0% +created in this class with Kevin Lynch + + + align:start position:0% +created in this class with Kevin Lynch +and follows them to some + + align:start position:0% + + + + align:start position:0% + +extent cities are you seen as unique + + align:start position:0% +extent cities are you seen as unique + + + align:start position:0% +extent cities are you seen as unique +historical + + align:start position:0% +historical + + + align:start position:0% +historical +processes uh each city is a unique + + align:start position:0% +processes uh each city is a unique + + + align:start position:0% +processes uh each city is a unique +cumulative historical process a city can + + align:start position:0% +cumulative historical process a city can + + + align:start position:0% +cumulative historical process a city can +only be explained by telling a + + align:start position:0% +only be explained by telling a + + + align:start position:0% +only be explained by telling a +story you cannot generalize ize very + + align:start position:0% +story you cannot generalize ize very + + + align:start position:0% +story you cannot generalize ize very +much about cities what you can + + align:start position:0% +much about cities what you can + + + align:start position:0% +much about cities what you can +generalize about is the way of reading a + + align:start position:0% +generalize about is the way of reading a + + + align:start position:0% +generalize about is the way of reading a +city you you have to learn a standard + + align:start position:0% +city you you have to learn a standard + + + align:start position:0% +city you you have to learn a standard +way of looking at them so for instance + + align:start position:0% +way of looking at them so for instance + + + align:start position:0% +way of looking at them so for instance +rasmusen says Two Chief types are + + align:start position:0% +rasmusen says Two Chief types are + + + align:start position:0% +rasmusen says Two Chief types are +distinguishable among among large cities + + align:start position:0% +distinguishable among among large cities + + + align:start position:0% +distinguishable among among large cities +the concentrated and the scattered the + + align:start position:0% +the concentrated and the scattered the + + + align:start position:0% +the concentrated and the scattered the +former is the more common on the + + align:start position:0% +former is the more common on the + + + align:start position:0% +former is the more common on the +continent is clearly represented by the + + align:start position:0% +continent is clearly represented by the + + + align:start position:0% +continent is clearly represented by the +big government seats of Paris and Vienna + + align:start position:0% +big government seats of Paris and Vienna + + + align:start position:0% +big government seats of Paris and Vienna +and so on the second type is represented + + align:start position:0% +and so on the second type is represented + + + align:start position:0% +and so on the second type is represented +by the English town which now to many of + + align:start position:0% +by the English town which now to many of + + + align:start position:0% +by the English town which now to many of +us seems + + align:start position:0% + + + + align:start position:0% + +ideal the question of what is unique and + + align:start position:0% +ideal the question of what is unique and + + + align:start position:0% +ideal the question of what is unique and +what + + align:start position:0% + + + + align:start position:0% + +is + + align:start position:0% +is + + + align:start position:0% +is +generalized is a difference in some of + + align:start position:0% +generalized is a difference in some of + + + align:start position:0% +generalized is a difference in some of +these + + align:start position:0% +these + + + align:start position:0% +these +propositions even within this + + align:start position:0% +propositions even within this + + + align:start position:0% +propositions even within this +proposition of this the the unique + + align:start position:0% +proposition of this the the unique + + + align:start position:0% +proposition of this the the unique +historic + + align:start position:0% + + + + align:start position:0% + +process you have a book like Alan + + align:start position:0% +process you have a book like Alan + + + align:start position:0% +process you have a book like Alan +jacobs's book on + + align:start position:0% +jacobs's book on + + + align:start position:0% +jacobs's book on +streets which by the way doesn't include + + align:start position:0% +streets which by the way doesn't include + + + align:start position:0% +streets which by the way doesn't include +the nki prospect which is one of the + + align:start position:0% +the nki prospect which is one of the + + + align:start position:0% +the nki prospect which is one of the +great streets in the world it's only + + align:start position:0% +great streets in the world it's only + + + align:start position:0% +great streets in the world it's only +streets that Alan Jacobs has visited in + + align:start position:0% +streets that Alan Jacobs has visited in + + + align:start position:0% +streets that Alan Jacobs has visited in +science I don't know if you can + + align:start position:0% +science I don't know if you can + + + align:start position:0% +science I don't know if you can +do experimentation on the basis of only + + align:start position:0% +do experimentation on the basis of only + + + align:start position:0% +do experimentation on the basis of only +what you have visited but it's okay we + + align:start position:0% +what you have visited but it's okay we + + + align:start position:0% +what you have visited but it's okay we +are we we we + + align:start position:0% +are we we we + + + align:start position:0% +are we we we +handicapped uh + + align:start position:0% + + + + align:start position:0% + +but the cities the streets that he + + align:start position:0% +but the cities the streets that he + + + align:start position:0% +but the cities the streets that he +identifies uh are un each is unique it + + align:start position:0% +identifies uh are un each is unique it + + + align:start position:0% +identifies uh are un each is unique it +gives measurements of its width it give + + align:start position:0% +gives measurements of its width it give + + + align:start position:0% +gives measurements of its width it give +dimensions of the density around the + + align:start position:0% +dimensions of the density around the + + + align:start position:0% +dimensions of the density around the +street whereas bia's propositions which + + align:start position:0% +street whereas bia's propositions which + + + align:start position:0% +street whereas bia's propositions which +I'll discuss next Tuesday amongst others + + align:start position:0% +I'll discuss next Tuesday amongst others + + + align:start position:0% +I'll discuss next Tuesday amongst others +space syntax looks at streets merely as + + align:start position:0% +space syntax looks at streets merely as + + + align:start position:0% +space syntax looks at streets merely as +linkages in a topological environment in + + align:start position:0% +linkages in a topological environment in + + + align:start position:0% 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to +be reproduced and what is generalizable + + align:start position:0% +be reproduced and what is generalizable + + + align:start position:0% +be reproduced and what is generalizable +from that phenomenon I was on a review + + align:start position:0% +from that phenomenon I was on a review + + + align:start position:0% +from that phenomenon I was on a review +last January at + + align:start position:0% +last January at + + + align:start position:0% +last January at +Colombia for project the students did in + + align:start position:0% +Colombia for project the students did in + + + align:start position:0% +Colombia for project the students did in +Palestine in a small town in + + align:start position:0% +Palestine in a small town in + + + align:start position:0% +Palestine in a small town in +Palestine sponsored by reak + + align:start position:0% +Palestine sponsored by reak + + + align:start position:0% +Palestine sponsored by reak +NGO which is trying to establish + + align:start position:0% +NGO which is trying to establish + + + align:start position:0% +NGO which is trying to establish +Palestinian space and this was a project + + align:start position:0% +Palestinian space and this was a project + + + align:start position:0% +Palestinian space and this was a project +for a small town which had had no + + align:start position:0% +for a small town which had had no + + + align:start position:0% +for a small town which had had no +economic basee but the students + + align:start position:0% +economic basee but the students + + + align:start position:0% +economic basee but the students +were privileged to study the town and + + align:start position:0% +were privileged to study the town and + + + align:start position:0% +were privileged to study the town and +come up with suggestions for an e new + + align:start position:0% +come up with suggestions for an e new + + + align:start position:0% +come up with suggestions for an e new +economic + + align:start position:0% +economic + + + align:start position:0% +economic +base all the students took the form of + + align:start position:0% +base all the students took the form of + + + align:start position:0% +base all the students took the form of +the city that is the architecture and + + align:start position:0% +the city that is the architecture and + + + align:start position:0% +the city that is the architecture and +even although it was only partially + + align:start position:0% +even although it was only partially + + + align:start position:0% +even although it was only partially +still in use as the basis for its + + align:start position:0% +still in use as the basis for its + + + align:start position:0% +still in use as the basis for its +reconstruction there was something about + + align:start position:0% +reconstruction there was something about + + + align:start position:0% +reconstruction there was something about +its history its presence which needed to + + align:start position:0% 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vinegar + + align:start position:0% +business in vinegar + + + align:start position:0% +business in vinegar +production uh in Palestine they took an + + align:start position:0% +production uh in Palestine they took an + + + align:start position:0% +production uh in Palestine they took an +old building and if it wasn't large + + align:start position:0% +old building and if it wasn't large + + + align:start position:0% +old building and if it wasn't large +enough they added a small fraction one + + align:start position:0% +enough they added a small fraction one + + + align:start position:0% +enough they added a small fraction one +student came along and said the biggest + + align:start position:0% +student came along and said the biggest + + + align:start position:0% +student came along and said the biggest +problem in this town is garbage + + align:start position:0% +problem in this town is garbage + + + align:start position:0% +problem in this town is garbage +collection garbage is not 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have said something um +but it wasn't uh it was in New York and + + align:start position:0% +but it wasn't uh it was in New York and + + + align:start position:0% +but it wasn't uh it was in New York and +I felt like a provincial from Boston so + + align:start position:0% +I felt like a provincial from Boston so + + + align:start position:0% +I felt like a provincial from Boston so +I had nothing to say um but it was a + + align:start position:0% +I had nothing to say um but it was a + + + align:start position:0% +I had nothing to say um but it was a +very good example of the postulation + + align:start position:0% +very good example of the postulation + + + align:start position:0% +very good example of the postulation +that theor youi that the uniqueness of + + align:start position:0% +that theor youi that the uniqueness of + + + align:start position:0% +that theor youi that the uniqueness of +the historical + + align:start position:0% +the historical + + + align:start position:0% 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cases used by the John Carlo De Carlo + + align:start position:0% +of cases used by the John Carlo De Carlo + + + align:start position:0% +of cases used by the John Carlo De Carlo +in the El schools in uh in Italy um and + + align:start position:0% +in the El schools in uh in Italy um and + + + align:start position:0% +in the El schools in uh in Italy um and +so I took two examples by two great men + + align:start position:0% +so I took two examples by two great men + + + align:start position:0% +so I took two examples by two great men +John + + align:start position:0% + + + + align:start position:0% + +Rasen sees number one the vocation of + + align:start position:0% +Rasen sees number one the vocation of + + + align:start position:0% +Rasen sees number one the vocation of +seeing he talks + + align:start position:0% +seeing he talks + + + align:start position:0% +seeing he talks +about growing up in a small village in + + align:start position:0% +about growing up in a small village in + + + align:start position:0% +about growing up in a small village in +England and + + align:start position:0% +England and + + + align:start position:0% +England and +uh Li there was nothing to do so look + + align:start position:0% +uh Li there was nothing to do so look + + + align:start position:0% +uh Li there was nothing to do so look +through the windows at to the house next + + align:start position:0% +through the windows at to the house next + + + align:start position:0% +through the windows at to the house next +door and started learning how to pattern + + align:start position:0% +door and started learning how to pattern + + + align:start position:0% +door and started learning how to pattern +the brick + + align:start position:0% +the brick + + + align:start position:0% +the brick +work now this is something that I + + align:start position:0% +work now this is something that I + + + align:start position:0% +work now this is something that I +suppose not everybody should do I think + + align:start position:0% +suppose not everybody should do I think + + + align:start position:0% +suppose not everybody should do I think +we have more intelligent things to do + + align:start position:0% +we have more intelligent things to do + + + align:start position:0% +we have more intelligent things to do +but he talks about seeing as an + + align:start position:0% +but he talks about seeing as an + + + align:start position:0% +but he talks about seeing as an +constructive + + align:start position:0% +constructive + + + align:start position:0% +constructive +phenomenon uh as an intellectual + + align:start position:0% +phenomenon uh as an intellectual + + + align:start position:0% +phenomenon uh as an intellectual +activity which can be + + align:start position:0% +activity which can be + + + align:start position:0% +activity which can be +learned it's not + + align:start position:0% +learned it's not + + + align:start position:0% +learned it's not +automatic + + align:start position:0% +automatic + + + align:start position:0% +automatic +he from the visual to the social + + align:start position:0% +he from the visual to the social + + + align:start position:0% +he from the visual to the social +political he's he's professor of poetry + + align:start position:0% +political he's he's professor of poetry + + + align:start position:0% +political he's he's professor of poetry +at Oxford University one of the most + + align:start position:0% +at Oxford University one of the most + + + align:start position:0% +at Oxford University one of the most +important chairs in British + + align:start position:0% +important chairs in British + + + align:start position:0% +important chairs in British +Academia and slowly turns his attention + + align:start position:0% +Academia and slowly turns his attention + + + align:start position:0% +Academia and slowly turns his attention +to the fact that there's a distinction + + align:start position:0% +to the fact that 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he says that reading is an +combination of aesthetic and moral + + align:start position:0% +combination of aesthetic and moral + + + align:start position:0% +combination of aesthetic and moral +values + + align:start position:0% +values + + + align:start position:0% +values +he says you have to externalize the + + align:start position:0% +he says you have to externalize the + + + align:start position:0% +he says you have to externalize the +consequences of your experience + + align:start position:0% +consequences of your experience + + + align:start position:0% +consequences of your experience +therefore he writes these + + align:start position:0% + + + + align:start position:0% + +books and that's something to say about + + align:start position:0% +books and that's something to say about + + + align:start position:0% +books and that's something to say about +reading in memory how memory is an + + align:start position:0% +reading in memory how memory is an + + + align:start position:0% 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with your body +with eyes ears nose and + + align:start position:0% +with eyes ears nose and + + + align:start position:0% +with eyes ears nose and +feet number three you do it through the + + align:start position:0% +feet number three you do it through the + + + align:start position:0% +feet number three you do it through the +ey eyes of + + align:start position:0% +ey eyes of + + + align:start position:0% +ey eyes of +others he had a + + align:start position:0% + + + + align:start position:0% + +girlfriend who was an illiterate Irish + + align:start position:0% +girlfriend who was an illiterate Irish + + + align:start position:0% +girlfriend who was an illiterate Irish +worker he walked through the town with + + align:start position:0% +worker he walked through the town with + + + align:start position:0% +worker he walked through the town with +her and would ask her questions I don't + + align:start position:0% +her and would ask her questions I don't + + + align:start position:0% +her and would ask her questions I don't +understand why the windows are always + + align:start position:0% +understand why the windows are always + + + align:start position:0% +understand why the windows are always +closed and she would say the windows are + + align:start position:0% +closed and she would say the windows are + + + align:start position:0% +closed and she would say the windows are +closed because the smell is to whatever + + align:start position:0% +closed because the smell is to whatever + + + align:start position:0% +closed because the smell is to whatever +whatever and then + + align:start position:0% + + + + align:start position:0% + +you communicate your what you've + + align:start position:0% +you communicate your what you've + + + align:start position:0% +you communicate your what you've +read and you you go even further in his + + align:start position:0% +read and you you go even further in his + + + align:start position:0% +read and you you go even further in his +case Manchester was not a unique City + + align:start position:0% +case Manchester was not a unique City + + + align:start position:0% +case Manchester was not a unique City +for him he was reading a phenomenon + + align:start position:0% +for him he was reading a phenomenon + + + align:start position:0% +for him he was reading a phenomenon +which had Universal + + align:start position:0% + + + + align:start position:0% + +implications it's interesting that under + + align:start position:0% +implications it's interesting that under + + + align:start position:0% +implications it's interesting that under +marks and Engles + + align:start position:0% +marks and Engles + + + align:start position:0% +marks and Engles +cities and as late as + + align:start position:0% +cities and as late as + + + align:start position:0% +cities and as late as +1917 cities were not considered as + + align:start position:0% +1917 cities were not considered as + + + align:start position:0% +1917 cities were not considered as +significant in the Marxist + + align:start position:0% + + + + align:start position:0% + +dialogue there were larger issues at + + align:start position:0% +dialogue there were larger issues at + + + align:start position:0% +dialogue there were larger issues at +hand you had to change the structure of + + align:start position:0% +hand you had to change the structure of + + + align:start position:0% +hand you had to change the structure of +society and in as a byproduct cities + + align:start position:0% +society and in as a byproduct cities + + + align:start position:0% +society and in as a byproduct cities +would change + + align:start position:0% +would change + + + align:start position:0% +would change +automatically they doesn't work that way + + align:start position:0% +automatically they doesn't work that way + + + align:start position:0% +automatically they doesn't work that way +but so was the doctrine of early Marxist + + align:start position:0% +but so was the doctrine of early Marxist + + + align:start position:0% +but so was the doctrine of early Marxist +so Soviet + + align:start position:0% +so Soviet + + + align:start position:0% +so Soviet +Marxism and Engles himself + + align:start position:0% +Marxism and Engles himself + + + align:start position:0% +Marxism and Engles himself +changed uh there's a wonderful book + + align:start position:0% +changed uh there's a wonderful book + + + align:start position:0% +changed uh there's a wonderful book +called Marx's General recently published + + align:start position:0% +called Marx's General recently published + + + align:start position:0% +called Marx's General recently published +by an English writer which discusses + + align:start position:0% +by an English writer which discusses + + + align:start position:0% +by an English writer which discusses +engel's + + align:start position:0% +engel's + + + align:start position:0% +engel's +history uh in relation to Hegel and + + align:start position:0% +history uh in relation to Hegel and + + + align:start position:0% +history uh in relation to Hegel and +the Engles attended was in the Army in + + align:start position:0% +the Engles attended was in the Army in + + + align:start position:0% +the Engles attended was in the Army in +Berlin doing nothing so he attended a CL + + align:start position:0% +Berlin doing nothing so he attended a CL + + + align:start position:0% +Berlin doing nothing so he attended a CL +and religious philosophy taught at the + + align:start position:0% +and religious philosophy taught at the + + + align:start position:0% +and religious philosophy taught at the +University at that time religion was a + + align:start position:0% +University at that time religion was a + + + align:start position:0% +University at that time religion was a +fundamental component of the study of + + align:start position:0% +fundamental component of the study of + + + align:start position:0% +fundamental component of the study of +philosophy in his class was nor was + + align:start position:0% +philosophy in his class was nor was + + + align:start position:0% +philosophy in his class was nor was +skot bakunin the Russian + + align:start position:0% +skot bakunin the Russian + + + align:start position:0% +skot bakunin the Russian +Anarchist uh uh I forget the names of + + align:start position:0% +Anarchist uh uh I forget the names of + + + align:start position:0% +Anarchist uh uh I forget the names of +the others people who were there at the + + align:start position:0% +the others people who were there at the + + + align:start position:0% +the others people who were there at the +same time questioning whether + + align:start position:0% +same time questioning whether + + + align:start position:0% +same time questioning whether +Hegel hegel's work had just been started + + align:start position:0% +Hegel hegel's work had just been started + + + align:start position:0% +Hegel hegel's work had just been started +to be + + align:start position:0% +to be + + + align:start position:0% +to be +published and + + align:start position:0% + + + + align:start position:0% + +Engles + + align:start position:0% +Engles + + + align:start position:0% +Engles +again started + + align:start position:0% +again started + + + align:start position:0% +again started +adapting the pur purist Marxist + + align:start position:0% +adapting the pur purist Marxist + + + align:start position:0% +adapting the pur purist Marxist +doctrines to the reality of the + + align:start position:0% +doctrines to the reality of the + + + align:start position:0% +doctrines to the reality of the +situations he was + + align:start position:0% +situations he was + + + align:start position:0% +situations he was +facing uh in different parts of Europe + + align:start position:0% +facing uh in different parts of Europe + + + align:start position:0% +facing uh in different parts of Europe +as he + + align:start position:0% +as he + + + align:start position:0% +as he +traveled the notion + + align:start position:0% +traveled the notion + + + align:start position:0% +traveled the notion +of historians who claim the uniqueness + + align:start position:0% +of historians who claim the uniqueness + + + align:start position:0% +of historians who claim the uniqueness +of cities is + + align:start position:0% +of cities is + + + align:start position:0% +of cities is +widespread um writing about + + align:start position:0% +widespread um writing about + + + align:start position:0% +widespread um writing about +Venice um Mary McCarthy says there's + + align:start position:0% +Venice um Mary McCarthy says there's + + + align:start position:0% +Venice um Mary McCarthy says there's +nothing more to be said about Venice and + + align:start position:0% +nothing more to be said about Venice and + + + align:start position:0% +nothing more to be said about Venice and +quotes Napoleon Rasen Shelly PR all + + align:start position:0% +quotes Napoleon Rasen Shelly PR all + + + align:start position:0% +quotes Napoleon Rasen Shelly PR all +saying the same + + align:start position:0% +saying the same + + + align:start position:0% +saying the same +things and says I view writing about + + align:start position:0% +things and says I view writing about + + + align:start position:0% +things and says I view writing about +Venice says the newcomer I pity you says + + align:start position:0% +Venice says the newcomer I pity you says + + + align:start position:0% +Venice says the newcomer I pity you says +the old hand there's something a little + + align:start position:0% +the old hand there's something a little + + + align:start position:0% +the old hand there's something a little +boring about saying the same things + + align:start position:0% +boring about saying the same things + + + align:start position:0% +boring about saying the same things +about a city uh Walter Benjamin is a + + align:start position:0% +about a city uh Walter Benjamin is a + + + align:start position:0% +about a city uh Walter Benjamin is a +much more lively character a German + + align:start position:0% +much more lively character a German + + + align:start position:0% +much more lively character a German +philosopher who died in 1940 but wrote + + align:start position:0% +philosopher who died in 1940 but wrote + + + align:start position:0% +philosopher who died in 1940 but wrote +essays on cities his essay on Naples is + + align:start position:0% +essays on cities his essay on Naples is + + + align:start position:0% +essays on cities his essay on Naples is +particularly + + align:start position:0% +particularly + + + align:start position:0% +particularly +interesting never nevertheless no City + + align:start position:0% +interesting never nevertheless no City + + + align:start position:0% +interesting never nevertheless no City +can fade in the few hours of Sunday rest + + align:start position:0% +can fade in the few hours of Sunday rest + + + align:start position:0% +can fade in the few hours of Sunday rest +more rapidly than + + align:start position:0% +more rapidly than + + + align:start position:0% +more rapidly than +Naples here's a theory of the speed at + + align:start position:0% +Naples here's a theory of the speed at + + + align:start position:0% +Naples here's a theory of the speed at +which a city changes its form from + + align:start position:0% +which a city changes its form from + + + align:start position:0% +which a city changes its form from +working to rest I don't know if any + + align:start position:0% +working to rest I don't know if any + + + align:start position:0% +working to rest I don't know if any +other person who's ever observed the + + align:start position:0% +other person who's ever observed the + + + align:start position:0% +other person who's ever observed the +phenomenon observed the speed that + + align:start position:0% +phenomenon observed the speed that + + + align:start position:0% +phenomenon observed the speed that +cities change from one form to + + align:start position:0% +cities change from one form to + + + align:start position:0% +cities change from one form to +another he + + align:start position:0% +another he + + + align:start position:0% +another he +says the well-known list of + + align:start position:0% + + + + align:start position:0% + +of the seven deadly sins located pride + + align:start position:0% +of the seven deadly sins located pride + + + align:start position:0% +of the seven deadly sins located pride +in Genoa aest in Florence voluptuousness + + align:start position:0% +in Genoa aest in Florence voluptuousness + + + align:start position:0% +in Genoa aest in Florence voluptuousness +in Venice anger in bolognia greed in + + align:start position:0% +in Venice anger in bolognia greed in + + + align:start position:0% +in Venice anger in bolognia greed in +Milan Envy in Rome and indolence in + + align:start position:0% +Milan Envy in Rome and indolence in + + + align:start position:0% +Milan Envy in Rome and indolence in +Naples he + + align:start position:0% +Naples he + + + align:start position:0% +Naples he +then he then you know goes on to talk + + align:start position:0% +then he then you know goes on to talk + + + align:start position:0% +then he then you know goes on to talk +about uh uh what indolence means and + + align:start position:0% +about uh uh what indolence means and + + + align:start position:0% +about uh uh what indolence means and +paracity of buildings and Builds an + + align:start position:0% +paracity of buildings and Builds an + + + align:start position:0% +paracity of buildings and Builds an +incredible Cent natur structure of this + + align:start position:0% +incredible Cent natur structure of this + + + align:start position:0% +incredible Cent natur structure of this +place what you do with it is not + + align:start position:0% +place what you do with it is not + + + align:start position:0% +place what you do with it is not +important it's that a city is something + + align:start position:0% +important it's that a city is something + + + align:start position:0% +important it's that a city is something +as particular as the gestures that + + align:start position:0% +as particular as the gestures that + + + align:start position:0% +as particular as the gestures that +people make with their hands he claims + + align:start position:0% +people make with their hands he claims + + + align:start position:0% +people make with their hands he claims +that the gestures that people make with + + align:start position:0% +that the gestures that people make with + + + align:start position:0% +that the gestures that people make with +their hands with their nose with their + + align:start position:0% +their hands with their nose with their + + + align:start position:0% +their hands with their nose with their +eyes with their breasts in Naples is + + align:start position:0% + + + + align:start position:0% + +unique + + align:start position:0% +unique + + + align:start position:0% +unique +so it g + + align:start position:0% +so it g + + + align:start position:0% +so it g +you the extraordinary thing about B + + align:start position:0% +you the extraordinary thing about B + + + align:start position:0% +you the extraordinary thing about B +Walter Benjamin + + align:start position:0% +Walter Benjamin + + + align:start position:0% +Walter Benjamin +who is the tension between this attitude + + align:start position:0% +who is the tension between this attitude + + + align:start position:0% +who is the tension between this attitude +of finding the Deep structure of + + align:start position:0% +of finding the Deep structure of + + + align:start position:0% +of finding the Deep structure of +explanation of cities and being a + + align:start position:0% +explanation of cities and being a + + + align:start position:0% +explanation of cities and being a +Marxist + + align:start position:0% +Marxist + + + align:start position:0% +Marxist +himself as a Marxist like Engles he + + align:start position:0% +himself as a Marxist like Engles he + + + align:start position:0% +himself as a Marxist like Engles he +would only see Naples as a generalized + + align:start position:0% +would only see Naples as a generalized + + + align:start position:0% +would only see Naples as a generalized +phenomenon of Human + + align:start position:0% +phenomenon of Human + + + align:start position:0% +phenomenon of Human +Experience he would he would look for + + align:start position:0% +Experience he would he would look for + + + align:start position:0% +Experience he would he would look for +where poor people lived and where the + + align:start position:0% +where poor people lived and where the + + + align:start position:0% +where poor people lived and where the +forces of production were and so on + + align:start position:0% +forces of production were and so on + + + align:start position:0% +forces of production were and so on +instead he's attracted by this + + align:start position:0% +instead he's attracted by this + + + align:start position:0% +instead he's attracted by this +uniqueness phenomenon everything is + + align:start position:0% +uniqueness phenomenon everything is + + + align:start position:0% +uniqueness phenomenon everything is +unique he writes about Paris in similar + + align:start position:0% +unique he writes about Paris in similar + + + align:start position:0% +unique he writes about Paris in similar +ways um much less interesting than alter + + align:start position:0% +ways um much less interesting than alter + + + align:start position:0% +ways um much less interesting than alter +Benjamin of whom I'm a big fan so I + + align:start position:0% +Benjamin of whom I'm a big fan so I + + + align:start position:0% +Benjamin of whom I'm a big fan so I +shouldn't criticize him too + + align:start position:0% +shouldn't criticize him too + + + align:start position:0% +shouldn't criticize him too +much is + + align:start position:0% +much is + + + align:start position:0% +much is +uh the architectural critic Nook Schulz + + align:start position:0% +uh the architectural critic Nook Schulz + + + align:start position:0% +uh the architectural critic Nook Schulz +the no + + align:start position:0% +the no + + + align:start position:0% +the no +Norwegian uh critic who has made a who + + align:start position:0% +Norwegian uh critic who has made a who + + + align:start position:0% +Norwegian uh critic who has made a who +wrote a book called genius + + align:start position:0% +wrote a book called genius + + + align:start position:0% +wrote a book called genius +locai which suggests again that every + + align:start position:0% +locai which suggests again that every + + + align:start position:0% +locai which suggests again that every +town has a genius not every town he only + + align:start position:0% +town has a genius not every town he only + + + align:start position:0% +town has a genius not every town he only +selects a couple uh and then tries to + + align:start position:0% +selects a couple uh and then tries to + + + align:start position:0% +selects a couple uh and then tries to +explain what is the genius is so in + + align:start position:0% +explain what is the genius is so in + + + align:start position:0% +explain what is the genius is so in +Prague we read the following the + + align:start position:0% +Prague we read the following the + + + align:start position:0% +Prague we read the following the +fascination of Prague resides first of + + align:start position:0% +fascination of Prague resides first of + + + align:start position:0% +fascination of Prague resides first of +all in a strong sense of mystery big + + align:start position:0% +all in a strong sense of mystery big + + + align:start position:0% +all in a strong sense of mystery big +deal you know + + align:start position:0% +deal you know + + + align:start position:0% +deal you know +um you have the feeling that it's + + align:start position:0% +um you have the feeling that it's + + + align:start position:0% +um you have the feeling that it's +possible to penetrate ever deeper into + + align:start position:0% +possible to penetrate ever deeper into + + + align:start position:0% +possible to penetrate ever deeper into +things streets Gates Courtyards have an + + align:start position:0% +things streets Gates Courtyards have an + + + align:start position:0% +things streets Gates Courtyards have an +endless inside now that is maybe a + + align:start position:0% +endless inside now that is maybe a + + + align:start position:0% +endless inside now that is maybe a +profound observation of + + align:start position:0% +profound observation of + + + align:start position:0% +profound observation of +Prague but as a theory it says terribly + + align:start position:0% +Prague but as a theory it says terribly + + + align:start position:0% +Prague but as a theory it says terribly +little uh it's very + + align:start position:0% + + + + align:start position:0% + +much in carum + + align:start position:0% + + + + align:start position:0% + +he says those who visit carum are + + align:start position:0% +he says those who visit carum are + + + align:start position:0% +he says those who visit carum are +immediately struck by a strong quality + + align:start position:0% +immediately struck by a strong quality + + + align:start position:0% +immediately struck by a strong quality +of + + align:start position:0% +of + + + align:start position:0% +of +place + + align:start position:0% +place + + + align:start position:0% +place +well am I not struck by a strong quality + + align:start position:0% +well am I not struck by a strong quality + + + align:start position:0% +well am I not struck by a strong quality +of place if I enter + + align:start position:0% +of place if I enter + + + align:start position:0% +of place if I enter +Leon or is there measurement of the + + align:start position:0% +Leon or is there measurement of the + + + align:start position:0% +Leon or is there measurement of the +amount of qual quality that there is in + + align:start position:0% +amount of qual quality that there is in + + + align:start position:0% +amount of qual quality that there is in +carum as opposed to Leon there's no + + align:start position:0% +carum as opposed to Leon there's no + + + align:start position:0% +carum as opposed to Leon there's no +attempt to generalize about cities + + align:start position:0% +attempt to generalize about cities + + + align:start position:0% +attempt to generalize about cities +whatsoever if s sence is about + + align:start position:0% +whatsoever if s sence is about + + + align:start position:0% +whatsoever if s sence is about +generalization this is not anywhere near + + align:start position:0% +generalization this is not anywhere near + + + align:start position:0% +generalization this is not anywhere near +scientific it maybe what Architects do + + align:start position:0% +scientific it maybe what Architects do + + + align:start position:0% +scientific it maybe what Architects do +in + + align:start position:0% +in + + + align:start position:0% +in +reading or artists do which raises a + + align:start position:0% +reading or artists do which raises a + + + align:start position:0% +reading or artists do which raises a +very big unresolved conflict in urbanism + + align:start position:0% +very big unresolved conflict in urbanism + + + align:start position:0% +very big unresolved conflict in urbanism +between the it is as a function of art + + align:start position:0% +between the it is as a function of art + + + align:start position:0% +between the it is as a function of art +or function of science theories + + align:start position:0% +or function of science theories + + + align:start position:0% +or function of science theories +are especially seen as + + align:start position:0% +are especially seen as + + + align:start position:0% +are especially seen as +functions + + align:start position:0% +functions + + + align:start position:0% +functions +as estimates of knowledge in science and + + align:start position:0% +as estimates of knowledge in science and + + + align:start position:0% +as estimates of knowledge in science and +in social + + align:start position:0% +in social + + + align:start position:0% +in social +science we have not resolved + + align:start position:0% +science we have not resolved + + + align:start position:0% +science we have not resolved +to propose as we end up + + align:start position:0% +to propose as we end up + + + align:start position:0% +to propose as we end up +with this piece by the + + align:start position:0% +with this piece by the + + + align:start position:0% +with this piece by the +physicists on what is important to + + align:start position:0% +physicists on what is important to + + + align:start position:0% +physicists on what is important to +resolve in + + align:start position:0% +resolve in + + + align:start position:0% +resolve in +urbanism it may be that the distinction + + align:start position:0% +urbanism it may be that the distinction + + + align:start position:0% +urbanism it may be that the distinction +is between learning about cities + + align:start position:0% +is between learning about cities + + + align:start position:0% +is between learning about cities +throughout history because youve look at + + align:start position:0% +throughout history because youve look at + + + align:start position:0% +throughout history because youve look at +Prague you think of of looking at Sean + + align:start position:0% +Prague you think of of looking at Sean + + + align:start position:0% +Prague you think of of looking at Sean +and although rudol AR the gal + + align:start position:0% +and although rudol AR the gal + + + align:start position:0% +and although rudol AR the gal +psychologist says that if you look at + + align:start position:0% +psychologist says that if you look at + + + align:start position:0% +psychologist says that if you look at +Sean you should follow the following + + align:start position:0% +Sean you should follow the following + + + align:start position:0% +Sean you should follow the following +path with your eyes from red to Yellow + + align:start position:0% +path with your eyes from red to Yellow + + + align:start position:0% +path with your eyes from red to Yellow +back to green and these forms all fit + + align:start position:0% +back to green and these forms all fit + + + align:start position:0% +back to green and these forms all fit +into a a scientific explanation of what + + align:start position:0% +into a a scientific explanation of what + + + align:start position:0% +into a a scientific explanation of what +you see that's + + align:start position:0% + + + + align:start position:0% + + um we accept certain truths + + align:start position:0% + um we accept certain truths + + + align:start position:0% + um we accept certain truths +through ART the patterning of music + + align:start position:0% +through ART the patterning of music + + + align:start position:0% +through ART the patterning of music +is studied and available for + + align:start position:0% +is studied and available for + + + align:start position:0% +is studied and available for +your understanding but it is an + + align:start position:0% +your understanding but it is an + + + align:start position:0% +your understanding but it is an +intuitive experiential + + align:start position:0% + + + + align:start position:0% + +phenomenon much of + + align:start position:0% +phenomenon much of + + + align:start position:0% +phenomenon much of +this these explanations are of that + + align:start position:0% +this these explanations are of that + + + align:start position:0% +this these explanations are of that +order they don't attempt to compare the + + align:start position:0% +order they don't attempt to compare the + + + align:start position:0% +order they don't attempt to compare the +amount of mystery in Rome versus the + + align:start position:0% +amount of mystery in Rome versus the + + + align:start position:0% +amount of mystery in Rome versus the +amount of mystery in carum or in + + align:start position:0% +amount of mystery in carum or in + + + align:start position:0% +amount of mystery in carum or in +Prague let's look go on very + + align:start position:0% + + + + align:start position:0% + +quickly we've got half an + + align:start position:0% +quickly we've got half an + + + align:start position:0% +quickly we've got half an +hour there's a lot of reading available + + align:start position:0% +hour there's a lot of reading available + + + align:start position:0% +hour there's a lot of reading available +about each of these sectors so I + + align:start position:0% +about each of these sectors so I + + + align:start position:0% +about each of these sectors so I +will propose that if you're interested + + align:start position:0% +will propose that if you're interested + + + align:start position:0% +will propose that if you're interested +in any of these bodies of work uh either + + align:start position:0% +in any of these bodies of work uh either + + + align:start position:0% +in any of these bodies of work uh either +contact me and I'll give you more + + align:start position:0% +contact me and I'll give you more + + + align:start position:0% +contact me and I'll give you more +reading that if you need to do more + + align:start position:0% +reading that if you need to do more + + + align:start position:0% +reading that if you need to do more +reading + + align:start position:0% +reading + + + align:start position:0% +reading +is enough in this class + + align:start position:0% + + + + align:start position:0% + +already + + align:start position:0% + + + + align:start position:0% + +um the next group of work is is number + + align:start position:0% +um the next group of work is is number + + + align:start position:0% +um the next group of work is is number +two Ecology of + + align:start position:0% +two Ecology of + + + align:start position:0% +two Ecology of +people + + align:start position:0% +people + + + align:start position:0% +people +um the idea that people as a group + + align:start position:0% +um the idea that people as a group + + + align:start position:0% +um the idea that people as a group +behave in in ways which pattern the + + align:start position:0% +behave in in ways which pattern the + + + align:start position:0% +behave in in ways which pattern the +city is most + + align:start position:0% +city is most + + + align:start position:0% +city is most +likely to be associated in the first + + align:start position:0% +likely to be associated in the first + + + align:start position:0% +likely to be associated in the first +instance with the work of the German + + align:start position:0% +instance with the work of the German + + + align:start position:0% +instance with the work of the German +sociologists from about 1900 to + + align:start position:0% +sociologists from about 1900 to + + + align:start position:0% +sociologists from about 1900 to +1950 um I'll just briefly mention them + + align:start position:0% +1950 um I'll just briefly mention them + + + align:start position:0% +1950 um I'll just briefly mention them +and talk a little bit about what their + + align:start position:0% +and talk a little bit about what their + + + align:start position:0% +and talk a little bit about what their +fundamental thinking about the nature of + + align:start position:0% +fundamental thinking about the nature of + + + align:start position:0% +fundamental thinking about the nature of +cities + + align:start position:0% +cities + + + align:start position:0% +cities +was Max + + align:start position:0% +was Max + + + align:start position:0% +was Max +Weber 19 five the three of Max Weber yor + + align:start position:0% +Weber 19 five the three of Max Weber yor + + + align:start position:0% +Weber 19 five the three of Max Weber yor +siml s i m m + + align:start position:0% +siml s i m m + + + align:start position:0% +siml s i m m +l and oswal + + align:start position:0% + + + + align:start position:0% + +Spangler for + + align:start position:0% +Spangler for + + + align:start position:0% +Spangler for +them cities were relatively + + align:start position:0% + + + + align:start position:0% + +new must remember that cities only grew + + align:start position:0% +new must remember that cities only grew + + + align:start position:0% +new must remember that cities only grew +at about 1% perom in your central in + + align:start position:0% +at about 1% perom in your central in + + + align:start position:0% +at about 1% perom in your central in +Europe until about then until 1930 + + align:start position:0% +Europe until about then until 1930 + + + align:start position:0% +Europe until about then until 1930 +when parts of England grew urbanistic at + + align:start position:0% +when parts of England grew urbanistic at + + + align:start position:0% +when parts of England grew urbanistic at +about + + align:start position:0% +about + + + align:start position:0% +about +10% + + align:start position:0% +10% + + + align:start position:0% +10% +um but it involved a change in + + align:start position:0% +um but it involved a change in + + + align:start position:0% +um but it involved a change in +character uh for ver a city is + + align:start position:0% +character uh for ver a city is + + + align:start position:0% +character uh for ver a city is +essentially a human settlement which + + align:start position:0% +essentially a human settlement which + + + align:start position:0% +essentially a human settlement which +could be called comp + + align:start position:0% +could be called comp + + + align:start position:0% +could be called comp +Cosmopolitan it contains a variety of + + align:start position:0% +Cosmopolitan it contains a variety of + + + align:start position:0% +Cosmopolitan it contains a variety of +LIF Styles and different sorts of + + align:start position:0% +LIF Styles and different sorts of + + + align:start position:0% +LIF Styles and different sorts of +individuals which have to + + align:start position:0% +individuals which have to + + + align:start position:0% +individuals which have to +coexist he argues that the best way for + + align:start position:0% +coexist he argues that the best way for + + + align:start position:0% +coexist he argues that the best way for +them + + align:start position:0% +them + + + align:start position:0% +them +coexisting is to establish ideal typical + + align:start position:0% +coexisting is to establish ideal typical + + + align:start position:0% +coexisting is to establish ideal typical +conditions in which each state of urban + + align:start position:0% +conditions in which each state of urban + + + align:start position:0% +conditions in which each state of urban +life most neatly fulfills the social + + align:start position:0% +life most neatly fulfills the social + + + align:start position:0% +life most neatly fulfills the social +capacities in the in inherent in any of + + align:start position:0% +capacities in the in inherent in any of + + + align:start position:0% +capacities in the in inherent in any of +the one + + align:start position:0% +the one + + + align:start position:0% +the one +groups so for him an ideal city would be + + align:start position:0% +groups so for him an ideal city would be + + + align:start position:0% +groups so for him an ideal city would be +uh + + align:start position:0% +uh + + + align:start position:0% +uh +the creation of a a a a a a a + + align:start position:0% +the creation of a a a a a a a + + + align:start position:0% +the creation of a a a a a a a +phenomenon which has a large amount of + + align:start position:0% +phenomenon which has a large amount of + + + align:start position:0% +phenomenon which has a large amount of +Distinction in it + + align:start position:0% + + + + align:start position:0% + +and uh the maintenance of these struct + + align:start position:0% +and uh the maintenance of these struct + + + align:start position:0% +and uh the maintenance of these struct +social structures competing social + + align:start position:0% +social structures competing social + + + align:start position:0% +social structures competing social +structures the capacity to understand + + align:start position:0% +structures the capacity to understand + + + align:start position:0% +structures the capacity to understand +when they change and when they + + align:start position:0% +when they change and when they + + + align:start position:0% +when they change and when they +don't + + align:start position:0% + + + + align:start position:0% + +he believes + + align:start position:0% +he believes + + + align:start position:0% +he believes +in in the kind of city that he was + + align:start position:0% +in in the kind of city that he was + + + align:start position:0% +in in the kind of city that he was +examining in Germany at the time George + + align:start position:0% +examining in Germany at the time George + + + align:start position:0% +examining in Germany at the time George +siml noticed another phenomenon of the + + align:start position:0% +siml noticed another phenomenon of the + + + align:start position:0% +siml noticed another phenomenon of the +emerging City form and that is that it + + align:start position:0% +emerging City form and that is that it + + + align:start position:0% +emerging City form and that is that it +put pressure on the individual + + align:start position:0% +put pressure on the individual + + + align:start position:0% +put pressure on the individual +existence the excess of psychic + + align:start position:0% +existence the excess of psychic + + + align:start position:0% +existence the excess of psychic +stimulation in a large city + + align:start position:0% +stimulation in a large city + + + align:start position:0% +stimulation in a large city +would cause + + align:start position:0% +would cause + + + align:start position:0% +would cause +withdrawal uh this is a strange + + align:start position:0% +withdrawal uh this is a strange + + + align:start position:0% +withdrawal uh this is a strange +concept uh + + align:start position:0% +concept uh + + + align:start position:0% +concept uh +it it maybe Associates it itself with + + align:start position:0% +it it maybe Associates it itself with + + + align:start position:0% +it it maybe Associates it itself with +people like Richard s Senate who's + + align:start position:0% +people like Richard s Senate who's + + + align:start position:0% +people like Richard s Senate who's +spoken about the the fall of public man + + align:start position:0% +spoken about the the fall of public man + + + align:start position:0% +spoken about the the fall of public man +in similar ways that + + align:start position:0% +in similar ways that + + + align:start position:0% +in similar ways that +the if in Sim Sim's case it was the + + align:start position:0% +the if in Sim Sim's case it was the + + + align:start position:0% +the if in Sim Sim's case it was the +withdraw all of people from the + + align:start position:0% +withdraw all of people from the + + + align:start position:0% +withdraw all of people from the +excessive stimulation of the city in + + align:start position:0% +excessive stimulation of the city in + + + align:start position:0% +excessive stimulation of the city in +Richard Senate's case it's the changing + + align:start position:0% +Richard Senate's case it's the changing + + + align:start position:0% +Richard Senate's case it's the changing +the capacity of people to from + + align:start position:0% +the capacity of people to from + + + align:start position:0% +the capacity of people to from +maintaining a state of publicness to a + + align:start position:0% +maintaining a state of publicness to a + + + align:start position:0% +maintaining a state of publicness to a +preference for a state of privacy I + + align:start position:0% +preference for a state of privacy I + + + align:start position:0% +preference for a state of privacy I +disagree with Senate to some extent + + align:start position:0% +disagree with Senate to some extent + + + align:start position:0% +disagree with Senate to some extent +about that + + align:start position:0% +about that + + + align:start position:0% +about that +observation uh as I'll deal with in the + + align:start position:0% +observation uh as I'll deal with in the + + + align:start position:0% +observation uh as I'll deal with in the +subsequent class uh the notion of + + align:start position:0% +subsequent class uh the notion of + + + align:start position:0% +subsequent class uh the notion of +privacy was foreign + + align:start position:0% +privacy was foreign + + + align:start position:0% +privacy was foreign +to people until the middle of the Middle + + align:start position:0% +to people until the middle of the Middle + + + align:start position:0% +to people until the middle of the Middle +Ages + + align:start position:0% +Ages + + + align:start position:0% +Ages +uh but + + align:start position:0% +uh but + + + align:start position:0% +uh but +simil + + align:start position:0% +simil + + + align:start position:0% +simil +uh talks of + + align:start position:0% + + + + align:start position:0% + +this whenever large s numbers of people + + align:start position:0% +this whenever large s numbers of people + + + align:start position:0% +this whenever large s numbers of people +live + + align:start position:0% +live + + + align:start position:0% +live +together there's a selfhood a human + + align:start position:0% +together there's a selfhood a human + + + align:start position:0% +together there's a selfhood a human +identity which tries to project itself + + align:start position:0% +identity which tries to project itself + + + align:start position:0% +identity which tries to project itself +in the + + align:start position:0% +in the + + + align:start position:0% +in the +process just as an example of this + + align:start position:0% + + + + align:start position:0% + +phenomenon if you would wish to withdraw + + align:start position:0% +phenomenon if you would wish to withdraw + + + align:start position:0% +phenomenon if you would wish to withdraw +in + + align:start position:0% +in + + + align:start position:0% +in +Manhattan from the + + align:start position:0% +Manhattan from the + + + align:start position:0% +Manhattan from the +intense energy that the city has + + align:start position:0% +intense energy that the city has + + + align:start position:0% +intense energy that the city has +produced + + align:start position:0% +produced + + + align:start position:0% +produced +um why would you have glass on the + + align:start position:0% +um why would you have glass on the + + + align:start position:0% +um why would you have glass on the +Windows of your + + align:start position:0% +Windows of your + + + align:start position:0% +Windows of your +apartment there's been some study of the + + align:start position:0% +apartment there's been some study of the + + + align:start position:0% +apartment there's been some study of the +amount of Glass on residential + + align:start position:0% +amount of Glass on residential + + + align:start position:0% +amount of Glass on residential +accommodation even to the extent that + + align:start position:0% +accommodation even to the extent that + + + align:start position:0% +accommodation even to the extent that +what is the form + + align:start position:0% +what is the form + + + align:start position:0% +what is the form +of old + + align:start position:0% +of old + + + align:start position:0% +of old +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +form + + align:start position:0% + + + + align:start position:0% + +uh + + align:start position:0% +uh + + + align:start position:0% +uh +where this man is in his apartment and + + align:start position:0% +where this man is in his apartment and + + + align:start position:0% +where this man is in his apartment and +he's hurt his legs so he can't move rear + + align:start position:0% +he's hurt his legs so he can't move rear + + + align:start position:0% +he's hurt his legs so he can't move rear +window yes who was the actor uh Jimmy + + align:start position:0% +window yes who was the actor uh Jimmy + + + align:start position:0% +window yes who was the actor uh Jimmy +Stewart Jimmy Stewart yeah yeah I'm + + align:start position:0% +Stewart Jimmy Stewart yeah yeah I'm + + + align:start position:0% +Stewart Jimmy Stewart yeah yeah I'm +sorry my memory is is falling + + align:start position:0% +sorry my memory is is falling + + + align:start position:0% +sorry my memory is is falling +apart um the phenomenon that you can use + + align:start position:0% +apart um the phenomenon that you can use + + + align:start position:0% +apart um the phenomenon that you can use +glass + + align:start position:0% + + + + align:start position:0% + +as glass gives you both the option of + + align:start position:0% +as glass gives you both the option of + + + align:start position:0% +as glass gives you both the option of +withdrawing and being + + align:start position:0% +withdrawing and being + + + align:start position:0% +withdrawing and being +public it's an extraordinary + + align:start position:0% +public it's an extraordinary + + + align:start position:0% +public it's an extraordinary +idea that if you really if siml were + + align:start position:0% +idea that if you really if siml were + + + align:start position:0% +idea that if you really if siml were +absolutely + + align:start position:0% +absolutely + + + align:start position:0% +absolutely +correct we would all live in turrets or + + align:start position:0% +correct we would all live in turrets or + + + align:start position:0% +correct we would all live in turrets or +in gardens or anything establishing + + align:start position:0% +in gardens or anything establishing + + + align:start position:0% +in gardens or anything establishing +ourselves outside of the turmoil of + + align:start position:0% +ourselves outside of the turmoil of + + + align:start position:0% +ourselves outside of the turmoil of +urbanism the glass apartment Block in + + align:start position:0% +urbanism the glass apartment Block in + + + align:start position:0% +urbanism the glass apartment Block in +manhatton allowing people to see you on + + align:start position:0% +manhatton allowing people to see you on + + + align:start position:0% +manhatton allowing people to see you on +when you're ready to be + + align:start position:0% +when you're ready to be + + + align:start position:0% +when you're ready to be +seen But most mostly available is a + + align:start position:0% +seen But most mostly available is a + + + align:start position:0% +seen But most mostly available is a +curious + + align:start position:0% +curious + + + align:start position:0% +curious +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +phenomenon siml might have had something + + align:start position:0% +phenomenon siml might have had something + + + align:start position:0% +phenomenon siml might have had something +to say + + align:start position:0% + + + + align:start position:0% + +about osal Spangler had a a + + align:start position:0% +about osal Spangler had a a + + + align:start position:0% +about osal Spangler had a a +typical negative view of + + align:start position:0% + + + + align:start position:0% + +the future of the emerging large + + align:start position:0% +the future of the emerging large + + + align:start position:0% +the future of the emerging large +city uh he said that it has very + + align:start position:0% +city uh he said that it has very + + + align:start position:0% +city uh he said that it has very +popularly understood at the time that + + align:start position:0% +popularly understood at the time that + + + align:start position:0% +popularly understood at the time that +there was something wrong that it needed + + align:start position:0% +there was something wrong that it needed + + + align:start position:0% +there was something wrong that it needed +to be ciled in size + + align:start position:0% +to be ciled in size + + + align:start position:0% +to be ciled in size +that uh its inre increasing hom + + align:start position:0% +that uh its inre increasing hom + + + align:start position:0% +that uh its inre increasing hom +heterogeneity was a phenomenon which was + + align:start position:0% +heterogeneity was a phenomenon which was + + + align:start position:0% +heterogeneity was a phenomenon which was +dangerous + + align:start position:0% +dangerous + + + align:start position:0% +dangerous +um + + align:start position:0% +um + + + align:start position:0% +um +uh he believed that cities would go + + align:start position:0% +uh he believed that cities would go + + + align:start position:0% +uh he believed that cities would go +would be destroyed and I don't know what + + align:start position:0% +would be destroyed and I don't know what + + + align:start position:0% +would be destroyed and I don't know what +would replace them but he had the + + align:start position:0% +would replace them but he had the + + + align:start position:0% +would replace them but he had the +similar idea to others in England that + + align:start position:0% +similar idea to others in England that + + + align:start position:0% +similar idea to others in England that +London would be + + align:start position:0% +London would be + + + align:start position:0% +London would be +dispersed and into small communities + + align:start position:0% +dispersed and into small communities + + + align:start position:0% +dispersed and into small communities +largely in the rural areas of + + align:start position:0% +largely in the rural areas of + + + align:start position:0% +largely in the rural areas of +England uh completely an + + align:start position:0% +England uh completely an + + + align:start position:0% +England uh completely an +that complete nonsense of an idea but + + align:start position:0% +that complete nonsense of an idea but + + + align:start position:0% +that complete nonsense of an idea but +one + + align:start position:0% + + + + align:start position:0% + +which the none of these + + align:start position:0% +which the none of these + + + align:start position:0% +which the none of these +people attempted to understand the + + align:start position:0% +people attempted to understand the + + + align:start position:0% +people attempted to understand the +sociology of an actual City they General + + align:start position:0% +sociology of an actual City they General + + + align:start position:0% +sociology of an actual City they General +they were + + align:start position:0% +they were + + + align:start position:0% +they were +generalists uh I'm reminded a little in + + align:start position:0% +generalists uh I'm reminded a little in + + + align:start position:0% +generalists uh I'm reminded a little in +reading of this to of a book which is + + align:start position:0% +reading of this to of a book which is + + + align:start position:0% +reading of this to of a book which is +recently published by + + align:start position:0% + + + + align:start position:0% + +um Edward Glazer at Harvard called + + align:start position:0% +um Edward Glazer at Harvard called + + + align:start position:0% +um Edward Glazer at Harvard called +the triph of the city Triumph of the + + align:start position:0% +the triph of the city Triumph of the + + + align:start position:0% +the triph of the city Triumph of the +city + + align:start position:0% + + + + align:start position:0% + +yes + + align:start position:0% +yes + + + align:start position:0% +yes +um there isn't really time to discuss + + align:start position:0% +um there isn't really time to discuss + + + align:start position:0% +um there isn't really time to discuss +this book at length but it's sometime in + + align:start position:0% +this book at length but it's sometime in + + + align:start position:0% +this book at length but it's sometime in +this class I would like to so ask me a + + align:start position:0% +this class I would like to so ask me a + + + align:start position:0% +this class I would like to so ask me a +question about it when we have more time + + align:start position:0% +question about it when we have more time + + + align:start position:0% +question about it when we have more time +uh its analysis is very much in the old + + align:start position:0% +uh its analysis is very much in the old + + + align:start position:0% +uh its analysis is very much in the old +school + + align:start position:0% +school + + + align:start position:0% +school +manner uh + + align:start position:0% +manner uh + + + align:start position:0% +manner uh +but if spingler proposes the cities will + + align:start position:0% +but if spingler proposes the cities will + + + align:start position:0% +but if spingler proposes the cities will +disappear because they are too crude and + + align:start position:0% +disappear because they are too crude and + + + align:start position:0% +disappear because they are too crude and +too they've deviated from decent human + + align:start position:0% +too they've deviated from decent human + + + align:start position:0% +too they've deviated from decent human +principles + + align:start position:0% +principles + + + align:start position:0% +principles +uh Glazer sees the future of interaction + + align:start position:0% +uh Glazer sees the future of interaction + + + align:start position:0% +uh Glazer sees the future of interaction +in the modern + + align:start position:0% +in the modern + + + align:start position:0% +in the modern +city as the essence of its + + align:start position:0% +city as the essence of its + + + align:start position:0% +city as the essence of its +being U he proposes that a good City + + align:start position:0% +being U he proposes that a good City + + + align:start position:0% +being U he proposes that a good City +would have would intensify + + align:start position:0% +would have would intensify + + + align:start position:0% +would have would intensify +interaction because it's economically + + align:start position:0% +interaction because it's economically + + + align:start position:0% +interaction because it's economically +important and so on and so on and so + + align:start position:0% +important and so on and so on and so + + + align:start position:0% +important and so on and so on and so +on um he's not an architect so he's P + + align:start position:0% +on um he's not an architect so he's P + + + align:start position:0% +on um he's not an architect so he's P +for tall buildings residential buildings + + align:start position:0% +for tall buildings residential buildings + + + align:start position:0% +for tall buildings residential buildings +um indiscriminate of how they are + + align:start position:0% +um indiscriminate of how they are + + + align:start position:0% +um indiscriminate of how they are +designed and how they are model + + align:start position:0% +designed and how they are model + + + align:start position:0% +designed and how they are model +modulated and so reminds me of what is + + align:start position:0% +modulated and so reminds me of what is + + + align:start position:0% +modulated and so reminds me of what is +happening in + + align:start position:0% +happening in + + + align:start position:0% +happening in +China uh amongst other places + + align:start position:0% +China uh amongst other places + + + align:start position:0% +China uh amongst other places +um The Chicago School were a bunch + + align:start position:0% +um The Chicago School were a bunch + + + align:start position:0% +um The Chicago School were a bunch +of sociologist who took a look at the + + align:start position:0% +of sociologist who took a look at the + + + align:start position:0% +of sociologist who took a look at the +American city for the first time + + align:start position:0% +American city for the first time + + + align:start position:0% +American city for the first time +analytically the concentric model uh of + + align:start position:0% +analytically the concentric model uh of + + + align:start position:0% +analytically the concentric model uh of +Park burges and + + align:start position:0% +Park burges and + + + align:start position:0% +Park burges and +McKenzie uh postulated a city + + align:start position:0% +McKenzie uh postulated a city + + + align:start position:0% +McKenzie uh postulated a city +which is much like a plant phenomenon + + align:start position:0% +which is much like a plant phenomenon + + + align:start position:0% +which is much like a plant phenomenon +that it increased and changed as it + + align:start position:0% +that it increased and changed as it + + + align:start position:0% +that it increased and changed as it +expanded outwards that the city + + align:start position:0% +expanded outwards that the city + + + align:start position:0% +expanded outwards that the city +consisted Rings annular rings of + + align:start position:0% +consisted Rings annular rings of + + + align:start position:0% +consisted Rings annular rings of +social + + align:start position:0% +social + + + align:start position:0% +social +classes um in which the dynamic was that + + align:start position:0% +classes um in which the dynamic was that + + + align:start position:0% +classes um in which the dynamic was that +you would move from the center to the + + align:start position:0% +you would move from the center to the + + + align:start position:0% +you would move from the center to the +outwards in the inner ring is the + + align:start position:0% + + + + align:start position:0% + +center the central business district + + align:start position:0% +center the central business district + + + align:start position:0% +center the central business district +immediately surrounding it is something + + align:start position:0% +immediately surrounding it is something + + + align:start position:0% +immediately surrounding it is something +called The Zone in + + align:start position:0% +called The Zone in + + + align:start position:0% +called The Zone in +transition beyond that is + + align:start position:0% +transition beyond that is + + + align:start position:0% +transition beyond that is +the zone + + align:start position:0% +the zone + + + align:start position:0% +the zone +of uh working men's houses beyond that + + align:start position:0% +of uh working men's houses beyond that + + + align:start position:0% +of uh working men's houses beyond that +is the zone of better residences beyond + + align:start position:0% +is the zone of better residences beyond + + + align:start position:0% +is the zone of better residences beyond +that is the commuter Zone The Zone of + + align:start position:0% +that is the commuter Zone The Zone of + + + align:start position:0% +that is the commuter Zone The Zone of +transition that immediate Zone around + + align:start position:0% +transition that immediate Zone around + + + align:start position:0% +transition that immediate Zone around +the central bu area is of + + align:start position:0% +the central bu area is of + + + align:start position:0% +the central bu area is of +Interest what distinguishes the American + + align:start position:0% +Interest what distinguishes the American + + + align:start position:0% +Interest what distinguishes the American +American city from the European city in + + align:start position:0% +American city from the European city in + + + align:start position:0% +American city from the European city in +the grossest sense is the American city + + align:start position:0% +the grossest sense is the American city + + + align:start position:0% +the grossest sense is the American city +is a city of immigration European city + + align:start position:0% +is a city of immigration European city + + + align:start position:0% +is a city of immigration European city +is quite the opposite it's only been + + align:start position:0% +is quite the opposite it's only been + + + align:start position:0% +is quite the opposite it's only been +open to reation recently and is + + align:start position:0% +open to reation recently and is + + + align:start position:0% +open to reation recently and is +struggling like hell to deal with it + + align:start position:0% +struggling like hell to deal with it + + + align:start position:0% +struggling like hell to deal with it +America's gone through a couple of + + align:start position:0% +America's gone through a couple of + + + align:start position:0% +America's gone through a couple of +hundred years if not + + align:start position:0% +hundred years if not + + + align:start position:0% +hundred years if not +forever uh dealing with a problem of + + align:start position:0% +forever uh dealing with a problem of + + + align:start position:0% +forever uh dealing with a problem of +immigration and the zone of transition + + align:start position:0% +immigration and the zone of transition + + + align:start position:0% +immigration and the zone of transition +in the American city was that under + + align:start position:0% +in the American city was that under + + + align:start position:0% +in the American city was that under +determined Zone before the settled + + align:start position:0% +determined Zone before the settled + + + align:start position:0% +determined Zone before the settled +residential population took place a Zone + + align:start position:0% +residential population took place a Zone + + + align:start position:0% +residential population took place a Zone +in transition the obvious phenomenon was + + align:start position:0% +in transition the obvious phenomenon was + + + align:start position:0% +in transition the obvious phenomenon was +that this is Zone which had + + align:start position:0% +that this is Zone which had + + + align:start position:0% +that this is Zone which had +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +a more rapid turnover than any other + + align:start position:0% +a more rapid turnover than any other + + + align:start position:0% +a more rapid turnover than any other +Zone in the city and this has actually + + align:start position:0% +Zone in the city and this has actually + + + align:start position:0% +Zone in the city and this has actually +been the The Zone which has been a zone + + align:start position:0% +been the The Zone which has been a zone + + + align:start position:0% +been the The Zone which has been a zone +of + + align:start position:0% +of + + + align:start position:0% +of +immigration a zone of building of + + align:start position:0% +immigration a zone of building of + + + align:start position:0% +immigration a zone of building of +bypasses past the central buiness this + + align:start position:0% +bypasses past the central buiness this + + + align:start position:0% +bypasses past the central buiness this +area in fact if anything it's a better + + align:start position:0% +area in fact if anything it's a better + + + align:start position:0% +area in fact if anything it's a better +Flex Zone around the center of the city + + align:start position:0% +Flex Zone around the center of the city + + + align:start position:0% +Flex Zone around the center of the city +than the park system of Adelaide which + + align:start position:0% +than the park system of Adelaide which + + + align:start position:0% +than the park system of Adelaide which +the organic model so enthused about + + align:start position:0% + + + + align:start position:0% + +um there was a gentleman called hom hoit + + align:start position:0% +um there was a gentleman called hom hoit + + + align:start position:0% +um there was a gentleman called hom hoit +who during the Depression years in + + align:start position:0% +who during the Depression years in + + + align:start position:0% +who during the Depression years in +Washington did nothing else that be + + align:start position:0% +Washington did nothing else that be + + + align:start position:0% +Washington did nothing else that be +without a computer calculated rent + + align:start position:0% +without a computer calculated rent + + + align:start position:0% +without a computer calculated rent +payments in cities in the United States + + align:start position:0% +payments in cities in the United States + + + align:start position:0% +payments in cities in the United States +particularly in Chicago written a book + + align:start position:0% +particularly in Chicago written a book + + + align:start position:0% +particularly in Chicago written a book +about Chicago from which he developed a + + align:start position:0% +about Chicago from which he developed a + + + align:start position:0% +about Chicago from which he developed a +an alternative model to the concentric + + align:start position:0% +an alternative model to the concentric + + + align:start position:0% +an alternative model to the concentric +model that is he claims that a city is + + align:start position:0% +model that is he claims that a city is + + + align:start position:0% +model that is he claims that a city is +really patented on the basis of + + align:start position:0% +really patented on the basis of + + + align:start position:0% +really patented on the basis of +sectors sectors Dev allow people to move + + align:start position:0% +sectors sectors Dev allow people to move + + + align:start position:0% +sectors sectors Dev allow people to move +towards higher income areas towards open + + align:start position:0% +towards higher income areas towards open + + + align:start position:0% +towards higher income areas towards open +space towards mountains towards higher + + align:start position:0% +space towards mountains towards higher + + + align:start position:0% +space towards mountains towards higher +natural food + + align:start position:0% +natural food + + + align:start position:0% +natural food +phenomenon uh and therefore you get a + + align:start position:0% +phenomenon uh and therefore you get a + + + align:start position:0% +phenomenon uh and therefore you get a +division of + + align:start position:0% +division of + + + align:start position:0% +division of +people rather than occupying space + + align:start position:0% +people rather than occupying space + + + align:start position:0% +people rather than occupying space +concentrically occupying space through + + align:start position:0% +concentrically occupying space through + + + align:start position:0% +concentrically occupying space through +wedges now if you look at the diagram of + + align:start position:0% +wedges now if you look at the diagram of + + + align:start position:0% +wedges now if you look at the diagram of +Atlanta you'll see some just Justice for + + align:start position:0% +Atlanta you'll see some just Justice for + + + align:start position:0% +Atlanta you'll see some just Justice for +his + + align:start position:0% +his + + + align:start position:0% +his +phenomenon it applies equally well to + + align:start position:0% +phenomenon it applies equally well to + + + align:start position:0% +phenomenon it applies equally well to +Johannesburg when I do a case study with + + align:start position:0% +Johannesburg when I do a case study with + + + align:start position:0% +Johannesburg when I do a case study with +you of Johannesburg you will see how the + + align:start position:0% +you of Johannesburg you will see how the + + + align:start position:0% +you of Johannesburg you will see how the +sector theory worked very well up to a + + align:start position:0% +sector theory worked very well up to a + + + align:start position:0% +sector theory worked very well up to a +certain point in the construction of in + + align:start position:0% +certain point in the construction of in + + + align:start position:0% +certain point in the construction of in +the organization of the city um in the + + align:start position:0% +the organization of the city um in the + + + align:start position:0% +the organization of the city um in the +case + + align:start position:0% + + + + align:start position:0% + +of Atlanta you have as I've said before + + align:start position:0% +of Atlanta you have as I've said before + + + align:start position:0% +of Atlanta you have as I've said before +U the phenomenon + + align:start position:0% +U the phenomenon + + + align:start position:0% +U the phenomenon +here uh based on rent + + align:start position:0% +here uh based on rent + + + align:start position:0% +here uh based on rent +payments + + align:start position:0% +payments + + + align:start position:0% +payments +um justifying the white + + align:start position:0% + + + + align:start position:0% + +model these The Chicago + + align:start position:0% +model these The Chicago + + + align:start position:0% +model these The Chicago +School took + + align:start position:0% +School took + + + align:start position:0% +School took +place in the great City of + + align:start position:0% +place in the great City of + + + align:start position:0% +place in the great City of +Chicago Chicago has been called the + + align:start position:0% +Chicago Chicago has been called the + + + align:start position:0% +Chicago Chicago has been called the +shock City + + align:start position:0% +shock City + + + align:start position:0% +shock City +because of its rapid + + align:start position:0% +because of its rapid + + + align:start position:0% +because of its rapid +emergence Chicago didn't exist in + + align:start position:0% +emergence Chicago didn't exist in + + + align:start position:0% +emergence Chicago didn't exist in +1830 and in 1893 at the time of the + + align:start position:0% +1830 and in 1893 at the time of the + + + align:start position:0% +1830 and in 1893 at the time of the +Chicago World's + + align:start position:0% +Chicago World's + + + align:start position:0% +Chicago World's +Fair 125th of all the world's railroads + + align:start position:0% +Fair 125th of all the world's railroads + + + align:start position:0% +Fair 125th of all the world's railroads +pass through + + align:start position:0% +pass through + + + align:start position:0% +pass through +kaga it's the most + + align:start position:0% +kaga it's the most + + + align:start position:0% +kaga it's the most +rapidly and + + align:start position:0% +rapidly and + + + align:start position:0% +rapidly and +be and by virtue of its rapid growth + + align:start position:0% +be and by virtue of its rapid growth + + + align:start position:0% +be and by virtue of its rapid growth +which wasn't accompanied by + + align:start position:0% +which wasn't accompanied by + + + align:start position:0% +which wasn't accompanied by +government or good + + align:start position:0% +government or good + + + align:start position:0% +government or good +government uh you have the phenomenon + + align:start position:0% +government uh you have the phenomenon + + + align:start position:0% +government uh you have the phenomenon +which I look into more carefully when we + + align:start position:0% +which I look into more carefully when we + + + align:start position:0% +which I look into more carefully when we +discuss the case of Chicago Chicago is + + align:start position:0% +discuss the case of Chicago Chicago is + + + align:start position:0% +discuss the case of Chicago Chicago is +the is the most phenomenal 19th century + + align:start position:0% +the is the most phenomenal 19th century + + + align:start position:0% +the is the most phenomenal 19th century +city of + + align:start position:0% +city of + + + align:start position:0% +city of +all and uh it's interesting that Chicago + + align:start position:0% +all and uh it's interesting that Chicago + + + align:start position:0% +all and uh it's interesting that Chicago +was the place where the first academic + + align:start position:0% +was the place where the first academic + + + align:start position:0% +was the place where the first academic +study of the social grouping of cities + + align:start position:0% +study of the social grouping of cities + + + align:start position:0% +study of the social grouping of cities +should take + + align:start position:0% +should take + + + align:start position:0% +should take +place + + align:start position:0% + + + + align:start position:0% + +a lot of things happened for the first + + align:start position:0% +a lot of things happened for the first + + + align:start position:0% +a lot of things happened for the first +time in + + align:start position:0% + + + + align:start position:0% + +Chicago economics has paid a serious but + + align:start position:0% +Chicago economics has paid a serious but + + + align:start position:0% +Chicago economics has paid a serious but +very scant interes in location as Paul + + align:start position:0% +very scant interes in location as Paul + + + align:start position:0% +very scant interes in location as Paul +Krugman put points + + align:start position:0% +Krugman put points + + + align:start position:0% +Krugman put points +out the new textbook by Joseph stigle at + + align:start position:0% +out the new textbook by Joseph stigle at + + + align:start position:0% +out the new textbook by Joseph stigle at +Harvard which is a thousand pages in L + + align:start position:0% +Harvard which is a thousand pages in L + + + align:start position:0% +Harvard which is a thousand pages in L +as the word City mentioned once and the + + align:start position:0% +as the word City mentioned once and the + + + align:start position:0% +as the word City mentioned once and the +word location mentioned + + align:start position:0% +word location mentioned + + + align:start position:0% +word location mentioned +once if you want to read about greed + + align:start position:0% +once if you want to read about greed + + + align:start position:0% +once if you want to read about greed +krugman's views on why economics is not + + align:start position:0% +krugman's views on why economics is not + + + align:start position:0% +krugman's views on why economics is not +included location as a serious input + + align:start position:0% +included location as a serious input + + + align:start position:0% +included location as a serious input +read the pieces that I've suggested you + + align:start position:0% +read the pieces that I've suggested you + + + align:start position:0% +read the pieces that I've suggested you +read They're two pieces by Krugman + + align:start position:0% +read They're two pieces by Krugman + + + align:start position:0% +read They're two pieces by Krugman +um explaining why the modern economics + + align:start position:0% +um explaining why the modern economics + + + align:start position:0% +um explaining why the modern economics +after + + align:start position:0% +after + + + align:start position:0% +after +Marshall uh managed very well on + + align:start position:0% +Marshall uh managed very well on + + + align:start position:0% +Marshall uh managed very well on +optimization theories without including + + align:start position:0% +optimization theories without including + + + align:start position:0% +optimization theories without including +the cost of Transportation or the cost + + align:start position:0% +the cost of Transportation or the cost + + + align:start position:0% +the cost of Transportation or the cost +the cost and benefits of + + align:start position:0% +the cost and benefits of + + + align:start position:0% +the cost and benefits of +location um he claims there's been a + + align:start position:0% +location um he claims there's been a + + + align:start position:0% +location um he claims there's been a +weakness in economic geography which has + + align:start position:0% +weakness in economic geography which has + + + align:start position:0% +weakness in economic geography which has +tried to measure up to the purity of + + align:start position:0% +tried to measure up to the purity of + + + align:start position:0% +tried to measure up to the purity of +Economics of modern economics and uh + + align:start position:0% +Economics of modern economics and uh + + + align:start position:0% +Economics of modern economics and uh +give some suggestions for maybe a new + + align:start position:0% +give some suggestions for maybe a new + + + align:start position:0% +give some suggestions for maybe a new +in post real estate study of location + + align:start position:0% +in post real estate study of location + + + align:start position:0% +in post real estate study of location +the classical location models + + align:start position:0% +the classical location models + + + align:start position:0% +the classical location models +are + + align:start position:0% +are + + + align:start position:0% +are +still number one at a regional level the + + align:start position:0% +still number one at a regional level the + + + align:start position:0% +still number one at a regional level the +more work of Von + + align:start position:0% +more work of Von + + + align:start position:0% +more work of Von +tunin the German + + align:start position:0% +tunin the German + + + align:start position:0% +tunin the German +agronomist who argued that look that the + + align:start position:0% +agronomist who argued that look that the + + + align:start position:0% +agronomist who argued that look that the +cost of Transportation was a phenomenon + + align:start position:0% +cost of Transportation was a phenomenon + + + align:start position:0% +cost of Transportation was a phenomenon +in allocating land use + + align:start position:0% +in allocating land use + + + align:start position:0% +in allocating land use +he claims + + align:start position:0% +he claims + + + align:start position:0% +he claims +that + + align:start position:0% +that + + + align:start position:0% +that +uh as I've said + + align:start position:0% +uh as I've said + + + align:start position:0% +uh as I've said +before + + align:start position:0% + + + + align:start position:0% + +uh this around around the center the + + align:start position:0% +uh this around around the center the + + + align:start position:0% +uh this around around the center the +spatial distribution of crops occurs + + align:start position:0% +spatial distribution of crops occurs + + + align:start position:0% +spatial distribution of crops occurs +according to the yield per unit or area + + align:start position:0% +according to the yield per unit or area + + + align:start position:0% +according to the yield per unit or area +around the central town + + align:start position:0% + + + + align:start position:0% + +you end up + + align:start position:0% +you end up + + + align:start position:0% +you end up +with dairy in the center orchards in + + align:start position:0% +with dairy in the center orchards in + + + align:start position:0% +with dairy in the center orchards in +this next ring grain in the next ring + + align:start position:0% +this next ring grain in the next ring + + + align:start position:0% +this next ring grain in the next ring +Earth cattle in the next ring and + + align:start position:0% +Earth cattle in the next ring and + + + align:start position:0% +Earth cattle in the next ring and +Forestry farther furthest from the + + align:start position:0% +Forestry farther furthest from the + + + align:start position:0% +Forestry farther furthest from the +center this is not only a function of + + align:start position:0% +center this is not only a function of + + + align:start position:0% +center this is not only a function of +land values but a function of the cost + + align:start position:0% +land values but a function of the cost + + + align:start position:0% +land values but a function of the cost +of transporting goods to the + + align:start position:0% + + + + align:start position:0% + +center Southern Germany where + + align:start position:0% +center Southern Germany where + + + align:start position:0% +center Southern Germany where +Von tun and and Christal and people like + + align:start position:0% +Von tun and and Christal and people like + + + align:start position:0% +Von tun and and Christal and people like +that economic geographers work was + + align:start position:0% +that economic geographers work was + + + align:start position:0% +that economic geographers work was +essentially + + align:start position:0% +essentially + + + align:start position:0% +essentially +flat and with population growth + + align:start position:0% +flat and with population growth + + + align:start position:0% +flat and with population growth +occurring at a very low + + align:start position:0% +occurring at a very low + + + align:start position:0% +occurring at a very low +rate uh the notion of a single Centered + + align:start position:0% +rate uh the notion of a single Centered + + + align:start position:0% +rate uh the notion of a single Centered +City or a distributed pattern of cities + + align:start position:0% +City or a distributed pattern of cities + + + align:start position:0% +City or a distributed pattern of cities +at regular intervals was + + align:start position:0% +at regular intervals was + + + align:start position:0% +at regular intervals was +appropriate + + align:start position:0% +appropriate + + + align:start position:0% +appropriate +um + + align:start position:0% +um + + + align:start position:0% +um +crystala base + + align:start position:0% +crystala base + + + align:start position:0% +crystala base +East economic geography on the idea that + + align:start position:0% +East economic geography on the idea that + + + align:start position:0% +East economic geography on the idea that +there were Central places uh and uh you + + align:start position:0% +there were Central places uh and uh you + + + align:start position:0% +there were Central places uh and uh you +can see this phenomenon in Northern + + align:start position:0% +can see this phenomenon in Northern + + + align:start position:0% +can see this phenomenon in Northern +Italy + + align:start position:0% +Italy + + + align:start position:0% +Italy +today from if you move Eastward from + + align:start position:0% +today from if you move Eastward from + + + align:start position:0% +today from if you move Eastward from +Milan you 30 miles from Milan is Pria 30 + + align:start position:0% +Milan you 30 miles from Milan is Pria 30 + + + align:start position:0% +Milan you 30 miles from Milan is Pria 30 +miles from Pria Verona Venza is 30 m + + align:start position:0% +miles from Pria Verona Venza is 30 m + + + align:start position:0% +miles from Pria Verona Venza is 30 m +from V + + align:start position:0% +from V + + + align:start position:0% +from V +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +pav Padova is 30 mil and Venice at the + + align:start position:0% +pav Padova is 30 mil and Venice at the + + + align:start position:0% +pav Padova is 30 mil and Venice at the +end of this horizontal East West + + align:start position:0% +end of this horizontal East West + + + align:start position:0% +end of this horizontal East West +axis if you go from Milan Milano to + + align:start position:0% +axis if you go from Milan Milano to + + + align:start position:0% +axis if you go from Milan Milano to +bolognia you have 30 miles to pava then + + align:start position:0% +bolognia you have 30 miles to pava then + + + align:start position:0% +bolognia you have 30 miles to pava then +30 m to Parma 30 mil to reio 30 mil to + + align:start position:0% +30 m to Parma 30 mil to reio 30 mil to + + + align:start position:0% +30 m to Parma 30 mil to reio 30 mil to +Moda and 30 miles to Bologna on the axis + + align:start position:0% +Moda and 30 miles to Bologna on the axis + + + align:start position:0% +Moda and 30 miles to Bologna on the axis +from bologna in the big triangle to + + align:start position:0% +from bologna in the big triangle to + + + align:start position:0% +from bologna in the big triangle to +Venice Yia Ferrara which is about 30 mi + + align:start position:0% +Venice Yia Ferrara which is about 30 mi + + + align:start position:0% +Venice Yia Ferrara which is about 30 mi +from bolognia and then historical land + + align:start position:0% +from bolognia and then historical land + + + align:start position:0% +from bolognia and then historical land +patterns didn't allow this phenomenon to + + align:start position:0% +patterns didn't allow this phenomenon to + + + align:start position:0% +patterns didn't allow this phenomenon to +take + + align:start position:0% + + + + align:start position:0% + +place there was a big exhibition in + + align:start position:0% +place there was a big exhibition in + + + align:start position:0% +place there was a big exhibition in +Italy entitled the culture of + + align:start position:0% +Italy entitled the culture of + + + align:start position:0% +Italy entitled the culture of + + align:start position:0% + + + align:start position:0% +cities what is interesting about + + align:start position:0% +cities what is interesting about + + + align:start position:0% +cities what is interesting about +Christal's interpretation for contemp + + align:start position:0% +Christal's interpretation for contemp + + + align:start position:0% +Christal's interpretation for contemp +times is that a place like + + align:start position:0% +times is that a place like + + + align:start position:0% +times is that a place like +Mona produces the headquarters of + + align:start position:0% +Mona produces the headquarters of + + + align:start position:0% +Mona produces the headquarters of +Lamborghini Ferrari and + + align:start position:0% +Lamborghini Ferrari and + + + align:start position:0% +Lamborghini Ferrari and +Maserati and still is a relatively small + + align:start position:0% +Maserati and still is a relatively small + + + align:start position:0% +Maserati and still is a relatively small +population Center you go to Cortona near + + align:start position:0% +population Center you go to Cortona near + + + align:start position:0% +population Center you go to Cortona near +areto it + + align:start position:0% +areto it + + + align:start position:0% +areto it +has a bunch of things almost every small + + align:start position:0% +has a bunch of things almost every small + + + align:start position:0% +has a bunch of things almost every small +town has a center and a condition of + + align:start position:0% +town has a center and a condition of + + + align:start position:0% +town has a center and a condition of +uniqueness + + align:start position:0% +uniqueness + + + align:start position:0% +uniqueness +The Genius of the Italian landscape is + + align:start position:0% +The Genius of the Italian landscape is + + + align:start position:0% +The Genius of the Italian landscape is +in not + + align:start position:0% +in not + + + align:start position:0% +in not +developing well so they they argue they + + align:start position:0% +developing well so they they argue they + + + align:start position:0% +developing well so they they argue they +haven't developed large cities Milano is + + align:start position:0% +haven't developed large cities Milano is + + + align:start position:0% +haven't developed large cities Milano is +not a village uh but the Italians are + + align:start position:0% +not a village uh but the Italians are + + + align:start position:0% +not a village uh but the Italians are +free to interpret things very freely uh + + align:start position:0% +free to interpret things very freely uh + + + align:start position:0% +free to interpret things very freely uh +but the genius of being able to be small + + align:start position:0% +but the genius of being able to be small + + + align:start position:0% +but the genius of being able to be small +and yet to be unique and + + align:start position:0% +and yet to be unique and + + + align:start position:0% +and yet to be unique and +to I was asked to come to Ferrara + + align:start position:0% +to I was asked to come to Ferrara + + + align:start position:0% +to I was asked to come to Ferrara +once uh because the the they started New + + align:start position:0% +once uh because the the they started New + + + align:start position:0% +once uh because the the they started New +School of Architecture run by a friend + + align:start position:0% +School of Architecture run by a friend + + + align:start position:0% +School of Architecture run by a friend +of mine and the city was going to give + + align:start position:0% +of mine and the city was going to give + + + align:start position:0% +of mine and the city was going to give +them a + + align:start position:0% +them a + + + align:start position:0% +them a +building and they wanted this small + + align:start position:0% +building and they wanted this small + + + align:start position:0% +building and they wanted this small +group of people to choose the building + + align:start position:0% +group of people to choose the building + + + align:start position:0% +group of people to choose the building +they CH took us to a building which + + align:start position:0% +they CH took us to a building which + + + align:start position:0% +they CH took us to a building which +they' given to the + + align:start position:0% +they' given to the + + + align:start position:0% +they' given to the +man who developed the first electronic + + align:start position:0% +man who developed the first electronic + + + align:start position:0% +man who developed the first electronic +system for the movies and it made a film + + align:start position:0% +system for the movies and it made a film + + + align:start position:0% +system for the movies and it made a film +which was very popular at the time + + align:start position:0% +which was very popular at the time + + + align:start position:0% +which was very popular at the time +possible prior to all of this computer + + align:start position:0% +possible prior to all of this computer + + + align:start position:0% +possible prior to all of this computer +stuff there was a sense in this town + + align:start position:0% +stuff there was a sense in this town + + + align:start position:0% +stuff there was a sense in this town +that there was an appreciation of his + + align:start position:0% +that there was an appreciation of his + + + align:start position:0% +that there was an appreciation of his +capacity to be located + + align:start position:0% +capacity to be located + + + align:start position:0% +capacity to be located +locally you bought food from the shop on + + align:start position:0% +locally you bought food from the shop on + + + align:start position:0% +locally you bought food from the shop on +the corner but yet he had an + + align:start position:0% +the corner but yet he had an + + + align:start position:0% +the corner but yet he had an +international aspiration and put + + align:start position:0% +international aspiration and put + + + align:start position:0% +international aspiration and put +together all of these places constant to + + align:start position:0% +together all of these places constant to + + + align:start position:0% +together all of these places constant to +the Italian Urban + + align:start position:0% + + + + align:start position:0% + +culture it's an strange phenomenon but + + align:start position:0% +culture it's an strange phenomenon but + + + align:start position:0% +culture it's an strange phenomenon but +it's the phenomen + + align:start position:0% +it's the phenomen + + + align:start position:0% +it's the phenomen +phenomenon which is worth noticing and + + align:start position:0% +phenomenon which is worth noticing and + + + align:start position:0% +phenomenon which is worth noticing and +it's a phenomenon which organizes the + + align:start position:0% +it's a phenomenon which organizes the + + + align:start position:0% +it's a phenomenon which organizes the +city and the country in a different way + + align:start position:0% +city and the country in a different way + + + align:start position:0% +city and the country in a different way +than the very large city and the very + + align:start position:0% +than the very large city and the very + + + align:start position:0% +than the very large city and the very +large spatial + + align:start position:0% +large spatial + + + align:start position:0% +large spatial +interland + + align:start position:0% +interland + + + align:start position:0% +interland +uh it's worth talking about in as we + + align:start position:0% +uh it's worth talking about in as we + + + align:start position:0% +uh it's worth talking about in as we +develop this class a bit further but it + + align:start position:0% +develop this class a bit further but it + + + align:start position:0% +develop this class a bit further but it +emanates from Christal's work c h r i s + + align:start position:0% +emanates from Christal's work c h r i s + + + align:start position:0% +emanates from Christal's work c h r i s +t a l l e + + align:start position:0% + + + + align:start position:0% + +r the third application of the classical + + align:start position:0% +r the third application of the classical + + + align:start position:0% +r the third application of the classical +economic model is in the distribution of + + align:start position:0% +economic model is in the distribution of + + + align:start position:0% +economic model is in the distribution of +activities in the + + align:start position:0% +activities in the + + + align:start position:0% +activities in the +center uh in in + + align:start position:0% +center uh in in + + + align:start position:0% +center uh in in +the Central City itself here you will + + align:start position:0% +the Central City itself here you will + + + align:start position:0% +the Central City itself here you will +have the phenomenon which seems very + + align:start position:0% +have the phenomenon which seems very + + + align:start position:0% +have the phenomenon which seems very +crude still at the moment that what are + + align:start position:0% +crude still at the moment that what are + + + align:start position:0% +crude still at the moment that what are +there are two variables the one is the + + align:start position:0% +there are two variables the one is the + + + align:start position:0% +there are two variables the one is the +amount of rent the money you want to pay + + align:start position:0% +amount of rent the money you want to pay + + + align:start position:0% +amount of rent the money you want to pay +in rent at one access and another AIS + + align:start position:0% +in rent at one access and another AIS + + + align:start position:0% +in rent at one access and another AIS +which says the distance that you can be + + align:start position:0% +which says the distance that you can be + + + align:start position:0% +which says the distance that you can be +from the center the argument being that + + align:start position:0% +from the center the argument being that + + + align:start position:0% +from the center the argument being that +in the center you pay higher rents and + + align:start position:0% +in the center you pay higher rents and + + + align:start position:0% +in the center you pay higher rents and +the further out you go the lower rents + + align:start position:0% +the further out you go the lower rents + + + align:start position:0% +the further out you go the lower rents +you pay but you have have to pay the + + align:start position:0% +you pay but you have have to pay the + + + align:start position:0% +you pay but you have have to pay the +increased Transportation costs so that + + align:start position:0% +increased Transportation costs so that + + + align:start position:0% +increased Transportation costs so that +balance + + align:start position:0% +balance + + + align:start position:0% +balance +will produce suburban and then exurban + + align:start position:0% +will produce suburban and then exurban + + + align:start position:0% +will produce suburban and then exurban +locations depending on the Improvement + + align:start position:0% +locations depending on the Improvement + + + align:start position:0% +locations depending on the Improvement +of the transportation system outwards + + align:start position:0% +of the transportation system outwards + + + align:start position:0% +of the transportation system outwards +that you'll get movements of + + align:start position:0% +that you'll get movements of + + + align:start position:0% +that you'll get movements of +people as + + align:start position:0% +people as + + + align:start position:0% +people as +they classically make more income from + + align:start position:0% +they classically make more income from + + + align:start position:0% +they classically make more income from +the center outwards and this + + align:start position:0% +the center outwards and this + + + align:start position:0% +the center outwards and this +is the workingclass people in the in + + align:start position:0% +is the workingclass people in the in + + + align:start position:0% +is the workingclass people in the in +this graph come in the form a curve in + + align:start position:0% +this graph come in the form a curve in + + + align:start position:0% +this graph come in the form a curve in +the center where they + + align:start position:0% +the center where they + + + align:start position:0% +the center where they +balance minimum costs of + + align:start position:0% +balance minimum costs of + + + align:start position:0% +balance minimum costs of +Transportation in public transportation + + align:start position:0% +Transportation in public transportation + + + align:start position:0% +Transportation in public transportation +with low medium RS and so on and so on + + align:start position:0% +with low medium RS and so on and so on + + + align:start position:0% +with low medium RS and so on and so on +what I saw do was otm it in the father + + align:start position:0% +what I saw do was otm it in the father + + + align:start position:0% +what I saw do was otm it in the father +Regional + + align:start position:0% +Regional + + + align:start position:0% +Regional +science uh is one of the formulators of + + align:start position:0% +science uh is one of the formulators of + + + align:start position:0% +science uh is one of the formulators of +this Theory uh Alonso at Harvard did + + align:start position:0% +this Theory uh Alonso at Harvard did + + + align:start position:0% +this Theory uh Alonso at Harvard did +versions of it Wingo M and + + align:start position:0% +versions of it Wingo M and + + + align:start position:0% +versions of it Wingo M and +others + + align:start position:0% + + + + align:start position:0% + +um let me just say a few words about the + + align:start position:0% +um let me just say a few words about the + + + align:start position:0% +um let me just say a few words about the +others in this + + align:start position:0% + + + + align:start position:0% + +list + + align:start position:0% + + + + align:start position:0% + +there have been attempts to modulate to + + align:start position:0% +there have been attempts to modulate to + + + align:start position:0% +there have been attempts to modulate to +modulate the form of cities by analogies + + align:start position:0% +modulate the form of cities by analogies + + + align:start position:0% +modulate the form of cities by analogies +to + + align:start position:0% +to + + + align:start position:0% +to +physics population potential being + + align:start position:0% +physics population potential being + + + align:start position:0% +physics population potential being +the + + align:start position:0% + + + + align:start position:0% + +uh let me get this correct I often make + + align:start position:0% +uh let me get this correct I often make + + + align:start position:0% +uh let me get this correct I often make +a mistake + + align:start position:0% + + + + align:start position:0% + +with well I'll forget about + + align:start position:0% +with well I'll forget about + + + align:start position:0% +with well I'll forget about +it we haven't got time to go into the + + align:start position:0% +it we haven't got time to go into the + + + align:start position:0% +it we haven't got time to go into the +great difference into the population + + align:start position:0% +great difference into the population + + + align:start position:0% +great difference into the population +potential model gravity models + + align:start position:0% +potential model gravity models + + + align:start position:0% +potential model gravity models +Communications networks and topology I + + align:start position:0% +Communications networks and topology I + + + align:start position:0% +Communications networks and topology I +should add to that more current work in + + align:start position:0% +should add to that more current work in + + + align:start position:0% +should add to that more current work in +fractal and Chaos + + align:start position:0% +fractal and Chaos + + + align:start position:0% +fractal and Chaos +Theory um which if you want to read + + align:start position:0% +Theory um which if you want to read + + + align:start position:0% +Theory um which if you want to read +about fractals read Gavin + + align:start position:0% +about fractals read Gavin + + + align:start position:0% +about fractals read Gavin +batty uh + + align:start position:0% +batty uh + + + align:start position:0% +batty uh +but I estimate these as having less of a + + align:start position:0% +but I estimate these as having less of a + + + align:start position:0% +but I estimate these as having less of a +life in determining current practice in + + align:start position:0% +life in determining current practice in + + + align:start position:0% +life in determining current practice in +urbanism than any of the others they + + align:start position:0% +urbanism than any of the others they + + + align:start position:0% +urbanism than any of the others they +somewhat academic gravity models + + align:start position:0% +somewhat academic gravity models + + + align:start position:0% +somewhat academic gravity models +Foresters Urban systems all of these + + align:start position:0% +Foresters Urban systems all of these + + + align:start position:0% +Foresters Urban systems all of these +form an attempt to + + align:start position:0% +form an attempt to + + + align:start position:0% +form an attempt to +use uh uh Notions of proximity not + + align:start position:0% +use uh uh Notions of proximity not + + + align:start position:0% +use uh uh Notions of proximity not +Notions of + + align:start position:0% +Notions of + + + align:start position:0% +Notions of +income uh to locate shopping centers to + + align:start position:0% +income uh to locate shopping centers to + + + align:start position:0% +income uh to locate shopping centers to +make modifications to the American city + + align:start position:0% +make modifications to the American city + + + align:start position:0% +make modifications to the American city +um the question of + + align:start position:0% +um the question of + + + align:start position:0% +um the question of +decisions link + + align:start position:0% +decisions link + + + align:start position:0% +decisions link +decisions uh again you we have to look + + align:start position:0% +decisions uh again you we have to look + + + align:start position:0% +decisions uh again you we have to look +at the work of people like Forester who + + align:start position:0% +at the work of people like Forester who + + + align:start position:0% +at the work of people like Forester who +claims that we'll see the same phenomen + + align:start position:0% +claims that we'll see the same phenomen + + + align:start position:0% +claims that we'll see the same phenomen +in the work of John Haren on + + align:start position:0% +in the work of John Haren on + + + align:start position:0% +in the work of John Haren on +Tuesday uh John + + align:start position:0% +Tuesday uh John + + + align:start position:0% +Tuesday uh John +Haren claim is that the built world is + + align:start position:0% +Haren claim is that the built world is + + + align:start position:0% +Haren claim is that the built world is +the fun is really the outcome of + + align:start position:0% +the fun is really the outcome of + + + align:start position:0% +the fun is really the outcome of +agreements that are made between + + align:start position:0% +agreements that are made between + + + align:start position:0% +agreements that are made between +different people there's no City but one + + align:start position:0% +different people there's no City but one + + + align:start position:0% +different people there's no City but one +that rests on made agreements and tries + + align:start position:0% +that rests on made agreements and tries + + + align:start position:0% +that rests on made agreements and tries +to determine from made agreements what + + align:start position:0% +to determine from made agreements what + + + align:start position:0% +to determine from made agreements what +could be the form of a city which takes + + align:start position:0% +could be the form of a city which takes + + + align:start position:0% +could be the form of a city which takes +that into account J + + align:start position:0% +that into account J + + + align:start position:0% +that into account J +Forester + + align:start position:0% +Forester + + + align:start position:0% +Forester +uh argues that social systems are count + + align:start position:0% +uh argues that social systems are count + + + align:start position:0% +uh argues that social systems are count +very complex and single answers are not + + align:start position:0% +very complex and single answers are not + + + align:start position:0% +very complex and single answers are not +predictable or not should not be + + align:start position:0% +predictable or not should not be + + + align:start position:0% +predictable or not should not be +expected um Urban systems are based on + + align:start position:0% +expected um Urban systems are based on + + + align:start position:0% +expected um Urban systems are based on +information about the importance thing + + align:start position:0% +information about the importance thing + + + align:start position:0% +information about the importance thing +decisions that largely businessman make + + align:start position:0% +decisions that largely businessman make + + + align:start position:0% +decisions that largely businessman make +in the American + + align:start position:0% +in the American + + + align:start position:0% +in the American +city uh he hasn't asked anybody or + + align:start position:0% +city uh he hasn't asked anybody or + + + align:start position:0% +city uh he hasn't asked anybody or +studied data of any significance he + + align:start position:0% +studied data of any significance he + + + align:start position:0% +studied data of any significance he +comes to + + align:start position:0% +comes to + + + align:start position:0% +comes to +simplistics resolutions that the more in + + align:start position:0% +simplistics resolutions that the more in + + + align:start position:0% +simplistics resolutions that the more in +the more the economy grows the more poor + + align:start position:0% +the more the economy grows the more poor + + + align:start position:0% +the more the economy grows the more poor +people you will have and things of this + + align:start position:0% +people you will have and things of this + + + align:start position:0% +people you will have and things of this +kind in um I'm not doing him just + + align:start position:0% +kind in um I'm not doing him just + + + align:start position:0% +kind in um I'm not doing him just +Justice in one + + align:start position:0% +Justice in one + + + align:start position:0% +Justice in one +sentence um then the arena of conflict + + align:start position:0% +sentence um then the arena of conflict + + + align:start position:0% +sentence um then the arena of conflict +which is really quite an interesting + + align:start position:0% +which is really quite an interesting + + + align:start position:0% +which is really quite an interesting +phenomenon + + align:start position:0% + + + + align:start position:0% + +um much of the models that I've gone + + align:start position:0% +um much of the models that I've gone + + + align:start position:0% +um much of the models that I've gone +through have + + align:start position:0% +through have + + + align:start position:0% +through have +assumed that the city is composed of + + align:start position:0% +assumed that the city is composed of + + + align:start position:0% +assumed that the city is composed of +benign people making benign agreements + + align:start position:0% +benign people making benign agreements + + + align:start position:0% +benign people making benign agreements +amongst each + + align:start position:0% + + + + align:start position:0% + +other Park and burgess's model of + + align:start position:0% +other Park and burgess's model of + + + align:start position:0% +other Park and burgess's model of +concentric circles means that it all + + align:start position:0% +concentric circles means that it all + + + align:start position:0% +concentric circles means that it all +like a plant takes place without the + + align:start position:0% +like a plant takes place without the + + + align:start position:0% +like a plant takes place without the +plant having any items of conflict or + + align:start position:0% +plant having any items of conflict or + + + align:start position:0% +plant having any items of conflict or +conflict as a phenomenon whereas in fact + + align:start position:0% +conflict as a phenomenon whereas in fact + + + align:start position:0% +conflict as a phenomenon whereas in fact +for long for many centuries the + + align:start position:0% +for long for many centuries the + + + align:start position:0% +for long for many centuries the +resolution of conflict to the building + + align:start position:0% +resolution of conflict to the building + + + align:start position:0% +resolution of conflict to the building +of walls was a fundamental aspect of + + align:start position:0% +of walls was a fundamental aspect of + + + align:start position:0% +of walls was a fundamental aspect of +City form + + align:start position:0% +City form + + + align:start position:0% +City form +vong + + align:start position:0% +vong + + + align:start position:0% +vong +the end of the 17th century the + + align:start position:0% +the end of the 17th century the + + + align:start position:0% +the end of the 17th century the +beginning of the 18th + + align:start position:0% +beginning of the 18th + + + align:start position:0% +beginning of the 18th +century uh could design a town which + + align:start position:0% +century uh could design a town which + + + align:start position:0% +century uh could design a town which +could not be penetrated so it his + + align:start position:0% +could not be penetrated so it his + + + align:start position:0% +could not be penetrated so it his +reputation was blond + + align:start position:0% +reputation was blond + + + align:start position:0% +reputation was blond +taught + + align:start position:0% +taught + + + align:start position:0% +taught +fortification to architecture students + + align:start position:0% +fortification to architecture students + + + align:start position:0% +fortification to architecture students +at the the academy in + + align:start position:0% +at the the academy in + + + align:start position:0% +at the the academy in +Paris + + align:start position:0% +Paris + + + align:start position:0% +Paris +um the people have taken up + + align:start position:0% +um the people have taken up + + + align:start position:0% +um the people have taken up +conflict really exist on the left + + align:start position:0% +conflict really exist on the left + + + align:start position:0% +conflict really exist on the left +there's David Gordon who explains + + align:start position:0% +there's David Gordon who explains + + + align:start position:0% +there's David Gordon who explains +American Suburbia by the movement of + + align:start position:0% +American Suburbia by the movement of + + + align:start position:0% +American Suburbia by the movement of +bosses to get away from workers in labor + + align:start position:0% +bosses to get away from workers in labor + + + align:start position:0% +bosses to get away from workers in labor +Strife you get money castels in his pre + + align:start position:0% +Strife you get money castels in his pre + + + align:start position:0% +Strife you get money castels in his pre +communication theory model mode who was + + align:start position:0% +communication theory model mode who was + + + align:start position:0% +communication theory model mode who was +a Spanish young Spanish + + align:start position:0% +a Spanish young Spanish + + + align:start position:0% +a Spanish young Spanish +Marxist uh who wrote something called + + align:start position:0% +Marxist uh who wrote something called + + + align:start position:0% +Marxist uh who wrote something called +The Wild City in which he claims that + + align:start position:0% +The Wild City in which he claims that + + + align:start position:0% +The Wild City in which he claims that +suburbanization is the function of + + align:start position:0% +suburbanization is the function of + + + align:start position:0% +suburbanization is the function of +surplus Commodities rather than of any + + align:start position:0% +surplus Commodities rather than of any + + + align:start position:0% +surplus Commodities rather than of any +any other form of + + align:start position:0% +any other form of + + + align:start position:0% +any other form of +economy uh + + align:start position:0% + + + + align:start position:0% + +uh um + + align:start position:0% +uh um + + + align:start position:0% +uh um +David + + align:start position:0% +David + + + align:start position:0% +David +Harvey arguing that it's very difficult + + align:start position:0% +Harvey arguing that it's very difficult + + + align:start position:0% +Harvey arguing that it's very difficult +to produce social equity and counter + + align:start position:0% +to produce social equity and counter + + + align:start position:0% +to produce social equity and counter +capitalism because there will always be + + align:start position:0% +capitalism because there will always be + + + align:start position:0% +capitalism because there will always be +obstacles in the way of + + align:start position:0% +obstacles in the way of + + + align:start position:0% +obstacles in the way of +maximizing return on + + align:start position:0% +maximizing return on + + + align:start position:0% +maximizing return on +Capital + + align:start position:0% + + + + align:start position:0% + +uh Leo the + + align:start position:0% + + + + align:start position:0% + +French sociologist who who ran a journal + + align:start position:0% +French sociologist who who ran a journal + + + align:start position:0% +French sociologist who who ran a journal +called Le SP + + align:start position:0% +called Le SP + + + align:start position:0% +called Le SP +soci uh I was editor of + + align:start position:0% +soci uh I was editor of + + + align:start position:0% +soci uh I was editor of +spio space and society which was uh I + + align:start position:0% +spio space and society which was uh I + + + align:start position:0% +spio space and society which was uh I +was part + + align:start position:0% +was part + + + align:start position:0% +was part +editor following the F's + + align:start position:0% +editor following the F's + + + align:start position:0% +editor following the F's +example + + align:start position:0% +example + + + align:start position:0% +example +um all of these are looking at the way + + align:start position:0% +um all of these are looking at the way + + + align:start position:0% +um all of these are looking at the way +in which conflict can be assumed and + + align:start position:0% +in which conflict can be assumed and + + + align:start position:0% +in which conflict can be assumed and +resolved as part of the real existence + + align:start position:0% +resolved as part of the real existence + + + align:start position:0% +resolved as part of the real existence +of a + + align:start position:0% +of a + + + align:start position:0% +of a +city + + align:start position:0% +city + + + align:start position:0% +city +uh John car dealo the Italian architect + + align:start position:0% +uh John car dealo the Italian architect + + + align:start position:0% +uh John car dealo the Italian architect +used to argue + + align:start position:0% +used to argue + + + align:start position:0% +used to argue +that one of the functions + + align:start position:0% +that one of the functions + + + align:start position:0% +that one of the functions +of one of the ways of displaying + + align:start position:0% +of one of the ways of displaying + + + align:start position:0% +of one of the ways of displaying +conflict was + + align:start position:0% +conflict was + + + align:start position:0% +conflict was +to allow architecture to build in its + + align:start position:0% +to allow architecture to build in its + + + align:start position:0% +to allow architecture to build in its +appropriate fashion but to depict the of + + align:start position:0% +appropriate fashion but to depict the of + + + align:start position:0% +appropriate fashion but to depict the of +conflict that are available and to + + align:start position:0% +conflict that are available and to + + + align:start position:0% +conflict that are available and to +heighten the sense of conflict in the + + align:start position:0% +heighten the sense of conflict in the + + + align:start position:0% +heighten the sense of conflict in the +city but also to make it possible in a + + align:start position:0% +city but also to make it possible in a + + + align:start position:0% +city but also to make it possible in a +kind of anarchic sense for that + + align:start position:0% +kind of anarchic sense for that + + + align:start position:0% +kind of anarchic sense for that +City's resolutions to be made within a + + align:start position:0% +City's resolutions to be made within a + + + align:start position:0% +City's resolutions to be made within a +framework of understood conflict + + align:start position:0% +framework of understood conflict + + + align:start position:0% +framework of understood conflict +resolvable conflict not + + align:start position:0% +resolvable conflict not + + + align:start position:0% +resolvable conflict not +Revolution uh so these attempts at + + align:start position:0% +Revolution uh so these attempts at + + + align:start position:0% +Revolution uh so these attempts at +plans uh + + align:start position:0% +plans uh + + + align:start position:0% +plans uh +sometimes Manifest this or at + + align:start position:0% +sometimes Manifest this or at + + + align:start position:0% +sometimes Manifest this or at +least if you look at the workers's + + align:start position:0% +least if you look at the workers's + + + align:start position:0% +least if you look at the workers's +housing interally for + + align:start position:0% +housing interally for + + + align:start position:0% +housing interally for +instance uh you can see elements of this + + align:start position:0% +instance uh you can see elements of this + + + align:start position:0% +instance uh you can see elements of this +proposition but it's very vague and very + + align:start position:0% +proposition but it's very vague and very + + + align:start position:0% +proposition but it's very vague and very +generalized and not really powerful + + align:start position:0% +generalized and not really powerful + + + align:start position:0% +generalized and not really powerful +Theory um the marxists have not produced + + align:start position:0% +Theory um the marxists have not produced + + + align:start position:0% +Theory um the marxists have not produced +cities + + align:start position:0% +cities + + + align:start position:0% +cities +which + + align:start position:0% +which + + + align:start position:0% +which +have + + align:start position:0% +have + + + align:start position:0% +have +externalized the conflict Notions which + + align:start position:0% +externalized the conflict Notions which + + + align:start position:0% +externalized the conflict Notions which +they examined in the ear the CI are much + + align:start position:0% +they examined in the ear the CI are much + + + align:start position:0% +they examined in the ear the CI are much +like any city in the world and Chinese + + align:start position:0% +like any city in the world and Chinese + + + align:start position:0% +like any city in the world and Chinese +Marxism is certainly not producing very + + align:start position:0% +Marxism is certainly not producing very + + + align:start position:0% +Marxism is certainly not producing very +much from which we can learn uh about + + align:start position:0% +much from which we can learn uh about + + + align:start position:0% +much from which we can learn uh about +New City + + align:start position:0% +New City + + + align:start position:0% +New City +growth + + align:start position:0% +growth + + + align:start position:0% +growth +uh so this particular theory is waiting + + align:start position:0% +uh so this particular theory is waiting + + + align:start position:0% +uh so this particular theory is waiting +to most of these + + align:start position:0% +to most of these + + + align:start position:0% +to most of these +theories let me just end off in + + align:start position:0% +theories let me just end off in + + + align:start position:0% +theories let me just end off in +one with this piece I gave + + align:start position:0% +one with this piece I gave + + + align:start position:0% +one with this piece I gave +you on the + + align:start position:0% + + + + align:start position:0% + +physics H the work of Jeffrey West yes + + align:start position:0% +physics H the work of Jeffrey West yes + + + align:start position:0% +physics H the work of Jeffrey West yes +do you know his work yeah what do you + + align:start position:0% +do you know his work yeah what do you + + + align:start position:0% +do you know his work yeah what do you +think of + + align:start position:0% +think of + + + align:start position:0% +think of +it I think I think it brings in an + + align:start position:0% +it I think I think it brings in an + + + align:start position:0% +it I think I think it brings in an +interesting + + align:start position:0% +interesting + + + align:start position:0% +interesting +perspective uh someone is + + align:start position:0% +perspective uh someone is + + + align:start position:0% +perspective uh someone is +finding on the + + align:start position:0% +finding on the + + + align:start position:0% +finding on the +the efficiency of CI and the ratios of + + align:start position:0% +the efficiency of CI and the ratios of + + + align:start position:0% +the efficiency of CI and the ratios of +investment versus how the population + + align:start position:0% +investment versus how the population + + + align:start position:0% +investment versus how the population +grows at the same time the per capital + + align:start position:0% +grows at the same time the per capital + + + align:start position:0% +grows at the same time the per capital +world that + + align:start position:0% +world that + + + align:start position:0% +world that +generat but it seems to be bit + + align:start position:0% +generat but it seems to be bit + + + align:start position:0% +generat but it seems to be bit +reductionist + + align:start position:0% + + + + align:start position:0% + +view you know it + + align:start position:0% +view you know it + + + align:start position:0% +view you know it +starts yeah it starts separating + + align:start position:0% +starts yeah it starts separating + + + align:start position:0% +starts yeah it starts separating +out what optimizes the functioning of a + + align:start position:0% +out what optimizes the functioning of a + + + align:start position:0% +out what optimizes the functioning of a +city in terms of transportation land use + + align:start position:0% +city in terms of transportation land use + + + align:start position:0% +city in terms of transportation land use +crime and so on which are important + + align:start position:0% +crime and so on which are important + + + align:start position:0% +crime and so on which are important +components to understand but he doesn't + + align:start position:0% +components to understand but he doesn't + + + align:start position:0% +components to understand but he doesn't +accept the city as an environment which + + align:start position:0% +accept the city as an environment which + + + align:start position:0% +accept the city as an environment which +has + + align:start position:0% +has + + + align:start position:0% +has +spatiality or experience or any of the + + align:start position:0% +spatiality or experience or any of the + + + align:start position:0% +spatiality or experience or any of the +things that art + + align:start position:0% +things that art + + + align:start position:0% +things that art +history I'm beginning to think more and + + align:start position:0% +history I'm beginning to think more and + + + align:start position:0% +history I'm beginning to think more and +more that in order to understand + + align:start position:0% +more that in order to understand + + + align:start position:0% +more that in order to understand +urbanism you need to study art + + align:start position:0% +urbanism you need to study art + + + align:start position:0% +urbanism you need to study art +history and perhaps forg about all of + + align:start position:0% +history and perhaps forg about all of + + + align:start position:0% +history and perhaps forg about all of +this stuff + + align:start position:0% + + + + align:start position:0% + +but we all know that every city is + + align:start position:0% +but we all know that every city is + + + align:start position:0% +but we all know that every city is +unique that's all we talk about when we + + align:start position:0% +unique that's all we talk about when we + + + align:start position:0% +unique that's all we talk about when we +talk about + + align:start position:0% +talk about + + + align:start position:0% +talk about +cities by but focusing on those + + align:start position:0% +cities by but focusing on those + + + align:start position:0% +cities by but focusing on those +differences misses the point sure there + + align:start position:0% +differences misses the point sure there + + + align:start position:0% +differences misses the point sure there +are differences but different from what + + align:start position:0% +are differences but different from what + + + align:start position:0% +are differences but different from what +we found the + + align:start position:0% +we found the + + + align:start position:0% +we found the +what there's an + + align:start position:0% +what there's an + + + align:start position:0% +what there's an +arrogance about the security of physics + + align:start position:0% +arrogance about the security of physics + + + align:start position:0% +arrogance about the security of physics +has applied to complex phenomena such as + + align:start position:0% +has applied to complex phenomena such as + + + align:start position:0% +has applied to complex phenomena such as +a + + align:start position:0% +a + + + align:start position:0% +a +city um it may be that this is a new + + align:start position:0% +city um it may be that this is a new + + + align:start position:0% +city um it may be that this is a new +generation of thinking I mean they're + + align:start position:0% +generation of thinking I mean they're + + + align:start position:0% +generation of thinking I mean they're +doing it at Oxford in Santa Fe and the + + align:start position:0% +doing it at Oxford in Santa Fe and the + + + align:start position:0% +doing it at Oxford in Santa Fe and the +more and more groups of complex + + align:start position:0% +more and more groups of complex + + + align:start position:0% +more and more groups of complex +theorists + + align:start position:0% +theorists + + + align:start position:0% +theorists +emerging I have my doubts and I'll be + + align:start position:0% +emerging I have my doubts and I'll be + + + align:start position:0% +emerging I have my doubts and I'll be +too old to see any of this anyway so I + + align:start position:0% +too old to see any of this anyway so I + + + align:start position:0% +too old to see any of this anyway so I +leave it for you on Tuesday we will look + + align:start position:0% +leave it for you on Tuesday we will look + + + align:start position:0% +leave it for you on Tuesday we will look +at for the last time in part one of this + + align:start position:0% +at for the last time in part one of this + + + align:start position:0% +at for the last time in part one of this +subject at four or five theories of + + align:start position:0% +subject at four or five theories of + + + align:start position:0% +subject at four or five theories of +Architects contemporary Architects or + + align:start position:0% +Architects contemporary Architects or + + + align:start position:0% +Architects contemporary Architects or +recently deceased Architects who've made + + align:start position:0% +recently deceased Architects who've made + + + align:start position:0% +recently deceased Architects who've made +attempts such as space + + align:start position:0% +attempts such as space + + + align:start position:0% +attempts such as space +syntax so on and so on um and then start + + align:start position:0% +syntax so on and so on um and then start + + + align:start position:0% +syntax so on and so on um and then start +from + + align:start position:0% +from + + + align:start position:0% +from +scratch with the Industrial Revolution + + align:start position:0% +scratch with the Industrial Revolution + + + align:start position:0% +scratch with the Industrial Revolution +and see what we can learn by looking + + align:start position:0% +and see what we can learn by looking + + + align:start position:0% +and see what we can learn by looking +carefully at + + align:start position:0% +carefully at + + + align:start position:0% +carefully at +phenomena \ No newline at end of file diff --git a/12K3PlcicZE.txt b/12K3PlcicZE.txt new file mode 100644 index 0000000000000000000000000000000000000000..0c78ff0052f768aa042364a18060a4c24db52801 --- /dev/null +++ b/12K3PlcicZE.txt @@ -0,0 +1,2147 @@ +align:start position:0% + +i won't tile this in with the discount + + align:start position:0% +i won't tile this in with the discount + + + align:start position:0% +i won't tile this in with the discount +rate here + + align:start position:0% +rate here + + + align:start position:0% +rate here +now + + align:start position:0% +now + + + align:start position:0% +now +when the demand for capacity is growing + + align:start position:0% +when the demand for capacity is growing + + + align:start position:0% +when the demand for capacity is growing +say for electricity + + align:start position:0% +say for electricity + + + align:start position:0% +say for electricity +you have two choices you can build a big + + align:start position:0% +you have two choices you can build a big + + + align:start position:0% +you have two choices you can build a big +plant now for many years ahead so i'm + + align:start position:0% +plant now for many years ahead so i'm + + + align:start position:0% +plant now for many years ahead so i'm +going to okay i'm going to build a plant + + align:start position:0% +going to okay i'm going to build a plant + + + align:start position:0% +going to okay i'm going to build a plant +for the next uh 20 years my father had + + align:start position:0% +for the next uh 20 years my father had + + + align:start position:0% +for the next uh 20 years my father had +this experience working actually in + + align:start position:0% +this experience working actually in + + + align:start position:0% +this experience working actually in +india on the when they were building the + + align:start position:0% +india on the when they were building the + + + align:start position:0% +india on the when they were building the +original steel mills about 30 or 40 + + align:start position:0% +original steel mills about 30 or 40 + + + align:start position:0% +original steel mills about 30 or 40 +years ago the whole pressure was build + + align:start position:0% +years ago the whole pressure was build + + + align:start position:0% +years ago the whole pressure was build +big plants get them really efficient + + align:start position:0% + + + + align:start position:0% + +that's one approach and the other + + align:start position:0% +that's one approach and the other + + + align:start position:0% +that's one approach and the other +approach is to build small now and some + + align:start position:0% +approach is to build small now and some + + + align:start position:0% +approach is to build small now and some +more smaller units later on as you phase + + align:start position:0% +more smaller units later on as you phase + + + align:start position:0% +more smaller units later on as you phase +the + + align:start position:0% +the + + + align:start position:0% +the +capacity according to the growth of the + + align:start position:0% +capacity according to the growth of the + + + align:start position:0% +capacity according to the growth of the +market + + align:start position:0% +market + + + align:start position:0% +market +so the choice a is based on economies of + + align:start position:0% +so the choice a is based on economies of + + + align:start position:0% +so the choice a is based on economies of +scale + + align:start position:0% +scale + + + align:start position:0% +scale +and the choice b + + align:start position:0% +and the choice b + + + align:start position:0% +and the choice b +has this particular feature which i want + + align:start position:0% +has this particular feature which i want + + + align:start position:0% +has this particular feature which i want +to emphasize here + + align:start position:0% +to emphasize here + + + align:start position:0% +to emphasize here +is that if you decide to build a + + align:start position:0% +is that if you decide to build a + + + align:start position:0% +is that if you decide to build a +capacity when you need it that is not + + align:start position:0% +capacity when you need it that is not + + + align:start position:0% +capacity when you need it that is not +all now + + align:start position:0% +all now + + + align:start position:0% +all now +because you're if you're building for + + align:start position:0% +because you're if you're building for + + + align:start position:0% +because you're if you're building for +the next 10 years or 15 years but maybe + + align:start position:0% +the next 10 years or 15 years but maybe + + + align:start position:0% +the next 10 years or 15 years but maybe +in three or four years + + align:start position:0% +in three or four years + + + align:start position:0% +in three or four years +that extra addition if your money is + + align:start position:0% +that extra addition if your money is + + + align:start position:0% +that extra addition if your money is +expensive you have a discount rate of + + align:start position:0% +expensive you have a discount rate of + + + align:start position:0% +expensive you have a discount rate of +ten percent or eight percent or whatever + + align:start position:0% +ten percent or eight percent or whatever + + + align:start position:0% +ten percent or eight percent or whatever +it might be + + align:start position:0% +it might be + + + align:start position:0% +it might be +might be say oh three three years later + + align:start position:0% +might be say oh three three years later + + + align:start position:0% +might be say oh three three years later +if i build that same plant + + align:start position:0% +if i build that same plant + + + align:start position:0% +if i build that same plant +i don't pay a hundred units because 100 + + align:start position:0% +i don't pay a hundred units because 100 + + + align:start position:0% +i don't pay a hundred units because 100 +of what i paid the first year well your + + align:start position:0% +of what i paid the first year well your + + + align:start position:0% +of what i paid the first year well your +check may be 400 percent but the present + + align:start position:0% +check may be 400 percent but the present + + + align:start position:0% +check may be 400 percent but the present +value of it would be discounted over + + align:start position:0% +value of it would be discounted over + + + align:start position:0% +value of it would be discounted over +three years and come in roughly speaking + + align:start position:0% +three years and come in roughly speaking + + + align:start position:0% +three years and come in roughly speaking +for orders of magnitude would be thirty + + align:start position:0% +for orders of magnitude would be thirty + + + align:start position:0% +for orders of magnitude would be thirty +percent uh less or if the discount rate + + align:start position:0% +percent uh less or if the discount rate + + + align:start position:0% +percent uh less or if the discount rate +was eight be about 25 percent less so + + align:start position:0% +was eight be about 25 percent less so + + + align:start position:0% +was eight be about 25 percent less so +the point is that by deferring the cost + + align:start position:0% +the point is that by deferring the cost + + + align:start position:0% +the point is that by deferring the cost +you counter balance the cost of the + + align:start position:0% +you counter balance the cost of the + + + align:start position:0% +you counter balance the cost of the +effective economy of scale + + align:start position:0% +effective economy of scale + + + align:start position:0% +effective economy of scale +if the argument is if i build it big + + align:start position:0% +if the argument is if i build it big + + + align:start position:0% +if the argument is if i build it big +it's cheaper per unit + + align:start position:0% +it's cheaper per unit + + + align:start position:0% +it's cheaper per unit +but if you delay + + align:start position:0% +but if you delay + + + align:start position:0% +but if you delay +the investments those other additions + + align:start position:0% +the investments those other additions + + + align:start position:0% +the investments those other additions +occur later in time + + align:start position:0% +occur later in time + + + align:start position:0% +occur later in time +and their cost is discounted so that + + align:start position:0% +and their cost is discounted so that + + + align:start position:0% +and their cost is discounted so that +the advantage of building large in the + + align:start position:0% +the advantage of building large in the + + + align:start position:0% +the advantage of building large in the +beginning are counter balanced so the + + align:start position:0% +beginning are counter balanced so the + + + align:start position:0% +beginning are counter balanced so the +discount rate counterbalance the economy + + align:start position:0% +discount rate counterbalance the economy + + + align:start position:0% +discount rate counterbalance the economy +the scale + + align:start position:0% +the scale + + + align:start position:0% +the scale +that is what you might gain + + align:start position:0% +that is what you might gain + + + align:start position:0% +that is what you might gain +by using + + align:start position:0% +by using + + + align:start position:0% +by using +economies of scale um in + + align:start position:0% +economies of scale um in + + + align:start position:0% +economies of scale um in +the control the productivity of the + + align:start position:0% +the control the productivity of the + + + align:start position:0% +the control the productivity of the +plant and principle you can lose by the + + align:start position:0% +plant and principle you can lose by the + + + align:start position:0% +plant and principle you can lose by the +economics + + align:start position:0% +economics + + + align:start position:0% +economics +now if you consider that economies of + + align:start position:0% +now if you consider that economies of + + + align:start position:0% +now if you consider that economies of +scale is a driver of the engineering + + align:start position:0% +scale is a driver of the engineering + + + align:start position:0% +scale is a driver of the engineering +design + + align:start position:0% +design + + + align:start position:0% +design +recognize the same point that many + + align:start position:0% +recognize the same point that many + + + align:start position:0% +recognize the same point that many +engineering designs what is the best + + align:start position:0% +engineering designs what is the best + + + align:start position:0% +engineering designs what is the best +technical design + + align:start position:0% +technical design + + + align:start position:0% +technical design +uh don't really factor in the economics + + align:start position:0% +uh don't really factor in the economics + + + align:start position:0% +uh don't really factor in the economics +of it they'll look at the + + align:start position:0% +of it they'll look at the + + + align:start position:0% +of it they'll look at the +all right you asked me to provide + + align:start position:0% +all right you asked me to provide + + + align:start position:0% +all right you asked me to provide +capacity this is the cheapest way to do + + align:start position:0% +capacity this is the cheapest way to do + + + align:start position:0% +capacity this is the cheapest way to do +it + + align:start position:0% +it + + + align:start position:0% +it +so + + align:start position:0% +so + + + align:start position:0% +so +this ties in this discussion ties in + + align:start position:0% +this ties in this discussion ties in + + + align:start position:0% +this ties in this discussion ties in +with the + + align:start position:0% +with the + + + align:start position:0% +with the +mit text + + align:start position:0% +mit text + + + align:start position:0% +mit text +simple case that i gave you a homework + + align:start position:0% +simple case that i gave you a homework + + + align:start position:0% +simple case that i gave you a homework +two that i've given you that you're + + align:start position:0% +two that i've given you that you're + + + align:start position:0% +two that i've given you that you're +turning in soon + + align:start position:0% +turning in soon + + + align:start position:0% +turning in soon +that you know if you look at it i've + + align:start position:0% +that you know if you look at it i've + + + align:start position:0% +that you know if you look at it i've +given you some particular numbers + + align:start position:0% +given you some particular numbers + + + align:start position:0% +given you some particular numbers +and of course your numbers depend on + + align:start position:0% +and of course your numbers depend on + + + align:start position:0% +and of course your numbers depend on +your special factors your own uh + + align:start position:0% +your special factors your own uh + + + align:start position:0% +your special factors your own uh +but very often the things with economy + + align:start position:0% +but very often the things with economy + + + align:start position:0% +but very often the things with economy +that scale just isn't a good design + + align:start position:0% +that scale just isn't a good design + + + align:start position:0% +that scale just isn't a good design +because on an economic basis from a + + align:start position:0% +because on an economic basis from a + + + align:start position:0% +because on an economic basis from a +productivity basis purely technically it + + align:start position:0% +productivity basis purely technically it + + + align:start position:0% +productivity basis purely technically it +looks great from a economic basis it may + + align:start position:0% +looks great from a economic basis it may + + + align:start position:0% +looks great from a economic basis it may +not there's x counter balancing of the + + align:start position:0% +not there's x counter balancing of the + + + align:start position:0% +not there's x counter balancing of the +of the discount rate counterbalances the + + align:start position:0% +of the discount rate counterbalances the + + + align:start position:0% +of the discount rate counterbalances the +economies of scale + + align:start position:0% + + + + align:start position:0% + +now this is compounded by this thing of + + align:start position:0% +now this is compounded by this thing of + + + align:start position:0% +now this is compounded by this thing of +learning + + align:start position:0% +learning + + + align:start position:0% +learning +that is + + align:start position:0% +that is + + + align:start position:0% +that is +what is this thing + + align:start position:0% +what is this thing + + + align:start position:0% +what is this thing +so learning is an experiment an + + align:start position:0% +so learning is an experiment an + + + align:start position:0% +so learning is an experiment an +empirical observation the production of + + align:start position:0% +empirical observation the production of + + + align:start position:0% +empirical observation the production of +more units + + align:start position:0% +more units + + + align:start position:0% +more units +uh gives a lower unit cost + + align:start position:0% +uh gives a lower unit cost + + + align:start position:0% +uh gives a lower unit cost +why is this + + align:start position:0% +why is this + + + align:start position:0% +why is this +well the first time for those of you who + + align:start position:0% +well the first time for those of you who + + + align:start position:0% +well the first time for those of you who +have ever gone camping and have had to + + align:start position:0% +have ever gone camping and have had to + + + align:start position:0% +have ever gone camping and have had to +raise a tent the first time you put your + + align:start position:0% +raise a tent the first time you put your + + + align:start position:0% +raise a tent the first time you put your +tent together you probably + + align:start position:0% +tent together you probably + + + align:start position:0% +tent together you probably +took a long time you had to figure out + + align:start position:0% +took a long time you had to figure out + + + align:start position:0% +took a long time you had to figure out +where part a went to part c and so forth + + align:start position:0% +where part a went to part c and so forth + + + align:start position:0% +where part a went to part c and so forth +and you hadn't done it before + + align:start position:0% +and you hadn't done it before + + + align:start position:0% +and you hadn't done it before +and by the time you've done it 10 or 15 + + align:start position:0% +and by the time you've done it 10 or 15 + + + align:start position:0% +and by the time you've done it 10 or 15 +times you can probably do it much faster + + align:start position:0% +times you can probably do it much faster + + + align:start position:0% +times you can probably do it much faster +that is you've learned something about + + align:start position:0% +that is you've learned something about + + + align:start position:0% +that is you've learned something about +it + + align:start position:0% +it + + + align:start position:0% +it +so + + align:start position:0% +so + + + align:start position:0% +so +it's a + + align:start position:0% +it's a + + + align:start position:0% +it's a +common kind of exp of + + align:start position:0% +common kind of exp of + + + align:start position:0% +common kind of exp of +industrial analysis to compare the cost + + align:start position:0% +industrial analysis to compare the cost + + + align:start position:0% +industrial analysis to compare the cost +of producing a unit whether it's a ship + + align:start position:0% +of producing a unit whether it's a ship + + + align:start position:0% +of producing a unit whether it's a ship +or a car or an oil platform + + align:start position:0% +or a car or an oil platform + + + align:start position:0% +or a car or an oil platform +by looking at what was the cost of first + + align:start position:0% +by looking at what was the cost of first + + + align:start position:0% +by looking at what was the cost of first +design was + + align:start position:0% +design was + + + align:start position:0% +design was +the cost of the second one like the + + align:start position:0% +the cost of the second one like the + + + align:start position:0% +the cost of the second one like the +first the stir and so forth + + align:start position:0% +first the stir and so forth + + + align:start position:0% +first the stir and so forth +and it's called learning on the basis + + align:start position:0% +and it's called learning on the basis + + + align:start position:0% +and it's called learning on the basis +that you on the idea that you've learned + + align:start position:0% +that you on the idea that you've learned + + + align:start position:0% +that you on the idea that you've learned +something how to do it better bet uh + + align:start position:0% +something how to do it better bet uh + + + align:start position:0% +something how to do it better bet uh +better it also may reflect frankly not + + align:start position:0% +better it also may reflect frankly not + + + align:start position:0% +better it also may reflect frankly not +just learning + + align:start position:0% +just learning + + + align:start position:0% +just learning +but also that you've + + align:start position:0% +but also that you've + + + align:start position:0% +but also that you've +changed the design somewhat you've + + align:start position:0% +changed the design somewhat you've + + + align:start position:0% +changed the design somewhat you've +tweaked it somehow so it's now more + + align:start position:0% +tweaked it somehow so it's now more + + + align:start position:0% +tweaked it somehow so it's now more +efficient + + align:start position:0% +efficient + + + align:start position:0% +efficient +but + + align:start position:0% +but + + + align:start position:0% +but +collectively it's known as the learning + + align:start position:0% +collectively it's known as the learning + + + align:start position:0% +collectively it's known as the learning +phenomenon and this can be very + + align:start position:0% +phenomenon and this can be very + + + align:start position:0% +phenomenon and this can be very +important i was working with bp at one + + align:start position:0% +important i was working with bp at one + + + align:start position:0% +important i was working with bp at one +time and for reasons which was counter + + align:start position:0% +time and for reasons which was counter + + + align:start position:0% +time and for reasons which was counter +there to their culture + + align:start position:0% +there to their culture + + + align:start position:0% +there to their culture +um + + align:start position:0% +um + + + align:start position:0% +um +when they were doing some drilling in + + align:start position:0% +when they were doing some drilling in + + + align:start position:0% +when they were doing some drilling in +azerbaijan + + align:start position:0% +azerbaijan + + + align:start position:0% +azerbaijan +uh + + align:start position:0% +uh + + + align:start position:0% +uh +that uh their + + align:start position:0% +that uh their + + + align:start position:0% +that uh their +standard practice was to uh have bespoke + + align:start position:0% +standard practice was to uh have bespoke + + + align:start position:0% +standard practice was to uh have bespoke +designs as designs particularly suited + + align:start position:0% +designs as designs particularly suited + + + align:start position:0% +designs as designs particularly suited +to the location the depth of water + + align:start position:0% +to the location the depth of water + + + align:start position:0% +to the location the depth of water +and um + + align:start position:0% +and um + + + align:start position:0% +and um +that didn't work for a variety of + + align:start position:0% +that didn't work for a variety of + + + align:start position:0% +that didn't work for a variety of +reasons so they made they actually + + align:start position:0% +reasons so they made they actually + + + align:start position:0% +reasons so they made they actually +implemented three platforms which were + + align:start position:0% +implemented three platforms which were + + + align:start position:0% +implemented three platforms which were +copies of each other + + align:start position:0% +copies of each other + + + align:start position:0% +copies of each other +and what they found was huge + + align:start position:0% +and what they found was huge + + + align:start position:0% +and what they found was huge +uh + + align:start position:0% +uh + + + align:start position:0% +uh +savings through this learning in that + + align:start position:0% +savings through this learning in that + + + align:start position:0% +savings through this learning in that +case particularly because + + align:start position:0% +case particularly because + + + align:start position:0% +case particularly because +by the time the teams came to do the + + align:start position:0% +by the time the teams came to do the + + + align:start position:0% +by the time the teams came to do the +second and third one they knew better + + align:start position:0% +second and third one they knew better + + + align:start position:0% +second and third one they knew better +how to sequence their + + align:start position:0% +how to sequence their + + + align:start position:0% +how to sequence their +use of labor and materials + + align:start position:0% +use of labor and materials + + + align:start position:0% +use of labor and materials +when to time things how to time things + + align:start position:0% +when to time things how to time things + + + align:start position:0% +when to time things how to time things +what was the better way of putting the + + align:start position:0% +what was the better way of putting the + + + align:start position:0% +what was the better way of putting the +pieces together just like learning how + + align:start position:0% +pieces together just like learning how + + + align:start position:0% +pieces together just like learning how +to put up a tent when you go camping + + align:start position:0% +to put up a tent when you go camping + + + align:start position:0% +to put up a tent when you go camping +so this effect which basically says if + + align:start position:0% +so this effect which basically says if + + + align:start position:0% +so this effect which basically says if +you build modules that are the same you + + align:start position:0% +you build modules that are the same you + + + align:start position:0% +you build modules that are the same you +can make it less expensive + + align:start position:0% +can make it less expensive + + + align:start position:0% +can make it less expensive +adds on in increases the effect of the + + align:start position:0% +adds on in increases the effect of the + + + align:start position:0% +adds on in increases the effect of the +discount rate insofar as it makes future + + align:start position:0% +discount rate insofar as it makes future + + + align:start position:0% +discount rate insofar as it makes future +investments of a series of modules uh + + align:start position:0% +investments of a series of modules uh + + + align:start position:0% +investments of a series of modules uh +cheaper + + align:start position:0% +cheaper + + + align:start position:0% +cheaper +so it is another add-on to the + + align:start position:0% +so it is another add-on to the + + + align:start position:0% +so it is another add-on to the +importance of + + align:start position:0% +importance of + + + align:start position:0% +importance of +the discount rate in terms of + + align:start position:0% +the discount rate in terms of + + + align:start position:0% +the discount rate in terms of +counterbalancing economies of scale + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% +um + + + align:start position:0% +um +right so i've just sort of said it but + + align:start position:0% +right so i've just sort of said it but + + + align:start position:0% +right so i've just sort of said it but +i'm calling it again + + align:start position:0% +i'm calling it again + + + align:start position:0% +i'm calling it again +learning is in quotes because it's not + + align:start position:0% +learning is in quotes because it's not + + + align:start position:0% +learning is in quotes because it's not +only learning you may have some + + align:start position:0% +only learning you may have some + + + align:start position:0% +only learning you may have some +technological + + align:start position:0% +technological + + + align:start position:0% +technological +improvements over time also you didn't + + align:start position:0% +improvements over time also you didn't + + + align:start position:0% +improvements over time also you didn't +have to have that piece as thick as the + + align:start position:0% +have to have that piece as thick as the + + + align:start position:0% +have to have that piece as thick as the +other ones because you found out you + + align:start position:0% +other ones because you found out you + + + align:start position:0% +other ones because you found out you +didn't need it and so forth so there are + + align:start position:0% +didn't need it and so forth so there are + + + align:start position:0% +didn't need it and so forth so there are +various ways you can improve on the + + align:start position:0% +various ways you can improve on the + + + align:start position:0% +various ways you can improve on the +design but it reflects the empirical + + align:start position:0% +design but it reflects the empirical + + + align:start position:0% +design but it reflects the empirical +understanding that as you an observable + + align:start position:0% +understanding that as you an observable + + + align:start position:0% +understanding that as you an observable +understanding as you make the same thing + + align:start position:0% +understanding as you make the same thing + + + align:start position:0% +understanding as you make the same thing +again and again you can do it + + align:start position:0% +again and again you can do it + + + align:start position:0% +again and again you can do it +less expensively and this can be + + align:start position:0% +less expensively and this can be + + + align:start position:0% +less expensively and this can be +quite important + + align:start position:0% + + + + align:start position:0% + +now the uh next one here is this notion + + align:start position:0% +now the uh next one here is this notion + + + align:start position:0% +now the uh next one here is this notion +of competitive gaming + + align:start position:0% +of competitive gaming + + + align:start position:0% +of competitive gaming +which is that + + align:start position:0% +which is that + + + align:start position:0% +which is that +it's not so easy to define + + align:start position:0% +it's not so easy to define + + + align:start position:0% +it's not so easy to define +directly but it basically says sometimes + + align:start position:0% +directly but it basically says sometimes + + + align:start position:0% +directly but it basically says sometimes +it's important to make a decision + + align:start position:0% +it's important to make a decision + + + align:start position:0% +it's important to make a decision +make a commitment in advance as a signal + + align:start position:0% +make a commitment in advance as a signal + + + align:start position:0% +make a commitment in advance as a signal +to competitors + + align:start position:0% +to competitors + + + align:start position:0% +to competitors +so the example i guess relate to here is + + align:start position:0% +so the example i guess relate to here is + + + align:start position:0% +so the example i guess relate to here is +when cortez invaded mexico + + align:start position:0% +when cortez invaded mexico + + + align:start position:0% +when cortez invaded mexico +and he came there by ship + + align:start position:0% +and he came there by ship + + + align:start position:0% +and he came there by ship +he deliberately burned his ship + + align:start position:0% + + + + align:start position:0% + +so he could not go back the implication + + align:start position:0% +so he could not go back the implication + + + align:start position:0% +so he could not go back the implication +being + + align:start position:0% +being + + + align:start position:0% +being +i am committed if you work with me i + + align:start position:0% +i am committed if you work with me i + + + align:start position:0% +i am committed if you work with me i +will be here because i am not going + + align:start position:0% +will be here because i am not going + + + align:start position:0% +will be here because i am not going +anywhere else i'm not going to uh + + align:start position:0% + + + + align:start position:0% + +decide to go home and leave you alone if + + align:start position:0% +decide to go home and leave you alone if + + + align:start position:0% +decide to go home and leave you alone if +you if you revolt against the aztec + + align:start position:0% +you if you revolt against the aztec + + + align:start position:0% +you if you revolt against the aztec +rulers + + align:start position:0% +rulers + + + align:start position:0% +rulers +i'm going to be here because i can't go + + align:start position:0% +i'm going to be here because i can't go + + + align:start position:0% +i'm going to be here because i can't go +anywhere else so + + align:start position:0% +anywhere else so + + + align:start position:0% +anywhere else so +it's + + align:start position:0% +it's + + + align:start position:0% +it's +attributed by some people that this was + + align:start position:0% +attributed by some people that this was + + + align:start position:0% +attributed by some people that this was +a an important aspect competitive aspect + + align:start position:0% +a an important aspect competitive aspect + + + align:start position:0% +a an important aspect competitive aspect +of saying we're not going to have any + + align:start position:0% +of saying we're not going to have any + + + align:start position:0% +of saying we're not going to have any +flexibility we're going to commit right + + align:start position:0% +flexibility we're going to commit right + + + align:start position:0% +flexibility we're going to commit right +now it's important + + align:start position:0% +now it's important + + + align:start position:0% +now it's important +and + + align:start position:0% +and + + + align:start position:0% +and +i'm now working with a company in + + align:start position:0% +i'm now working with a company in + + + align:start position:0% +i'm now working with a company in +morocco which produces phosphate and + + align:start position:0% +morocco which produces phosphate and + + + align:start position:0% +morocco which produces phosphate and +their view is + + align:start position:0% +their view is + + + align:start position:0% +their view is +somewhat similar + + align:start position:0% +somewhat similar + + + align:start position:0% +somewhat similar +they have uh they're committed to have + + align:start position:0% +they have uh they're committed to have + + + align:start position:0% +they have uh they're committed to have +bm + + align:start position:0% +bm + + + align:start position:0% +bm +to add on capacity to their production + + align:start position:0% +to add on capacity to their production + + + align:start position:0% +to add on capacity to their production +and it's a signal to everybody else that + + align:start position:0% +and it's a signal to everybody else that + + + align:start position:0% +and it's a signal to everybody else that +we are going to we intend to be the big + + align:start position:0% +we are going to we intend to be the big + + + align:start position:0% +we are going to we intend to be the big +uh producers on the block we intend to + + align:start position:0% +uh producers on the block we intend to + + + align:start position:0% +uh producers on the block we intend to +be the world's uh dominant producers and + + align:start position:0% +be the world's uh dominant producers and + + + align:start position:0% +be the world's uh dominant producers and +if you want to build your capacity and + + align:start position:0% +if you want to build your capacity and + + + align:start position:0% +if you want to build your capacity and +compete with us you're going to lose + + align:start position:0% +compete with us you're going to lose + + + align:start position:0% +compete with us you're going to lose +because we're going to have more of it + + align:start position:0% +because we're going to have more of it + + + align:start position:0% +because we're going to have more of it +we're going to be cheaper and we're + + align:start position:0% +we're going to be cheaper and we're + + + align:start position:0% +we're going to be cheaper and we're +going to dominate so + + align:start position:0% +going to dominate so + + + align:start position:0% +going to dominate so +that kind of thinking or very variance + + align:start position:0% +that kind of thinking or very variance + + + align:start position:0% +that kind of thinking or very variance +on this kind of thinking suggests + + align:start position:0% +on this kind of thinking suggests + + + align:start position:0% +on this kind of thinking suggests +illustrates tries to illustrate the + + align:start position:0% +illustrates tries to illustrate the + + + align:start position:0% +illustrates tries to illustrate the +point that + + align:start position:0% +point that + + + align:start position:0% +point that +eliminating flexibility it can be a good + + align:start position:0% +eliminating flexibility it can be a good + + + align:start position:0% +eliminating flexibility it can be a good +thing + + align:start position:0% +thing + + + align:start position:0% +thing +so + + align:start position:0% +so + + + align:start position:0% +so +the tendency of these principle drivers + + align:start position:0% +the tendency of these principle drivers + + + align:start position:0% +the tendency of these principle drivers +which i just referred to are the + + align:start position:0% +which i just referred to are the + + + align:start position:0% +which i just referred to are the +following first uncertainty + + align:start position:0% +following first uncertainty + + + align:start position:0% +following first uncertainty +emphasizes + + align:start position:0% +emphasizes + + + align:start position:0% +emphasizes +uh + + align:start position:0% +uh + + + align:start position:0% +uh +flexibility the cons is scaled against + + align:start position:0% +flexibility the cons is scaled against + + + align:start position:0% +flexibility the cons is scaled against +the discount rate is four the learning + + align:start position:0% +the discount rate is four the learning + + + align:start position:0% +the discount rate is four the learning +is four and the competitive again is + + align:start position:0% +is four and the competitive again is + + + align:start position:0% +is four and the competitive again is +against + + align:start position:0% +against + + + align:start position:0% +against +so + + align:start position:0% +so + + + align:start position:0% +so +uh this is where i want to + + align:start position:0% +uh this is where i want to + + + align:start position:0% +uh this is where i want to +let you think about it that when you're + + align:start position:0% +let you think about it that when you're + + + align:start position:0% +let you think about it that when you're +thinking about + + align:start position:0% +thinking about + + + align:start position:0% +thinking about +um + + align:start position:0% +um + + + align:start position:0% +um +where are the pros and cons for having + + align:start position:0% +where are the pros and cons for having + + + align:start position:0% +where are the pros and cons for having +economies of scale there are a number of + + align:start position:0% +economies of scale there are a number of + + + align:start position:0% +economies of scale there are a number of +issues to take into consideration + + align:start position:0% +issues to take into consideration + + + align:start position:0% +issues to take into consideration +it's not all + + align:start position:0% +it's not all + + + align:start position:0% +it's not all +if there's uncertainty you have to have + + align:start position:0% +if there's uncertainty you have to have + + + align:start position:0% +if there's uncertainty you have to have +a flexibility + + align:start position:0% +a flexibility + + + align:start position:0% +a flexibility +maybe maybe not you have to do the + + align:start position:0% +maybe maybe not you have to do the + + + align:start position:0% +maybe maybe not you have to do the +calculations and explore it to get it + + align:start position:0% +calculations and explore it to get it + + + align:start position:0% +calculations and explore it to get it +right but it's not clear what the answer + + align:start position:0% +right but it's not clear what the answer + + + align:start position:0% +right but it's not clear what the answer +has to be there's not one possible + + align:start position:0% +has to be there's not one possible + + + align:start position:0% +has to be there's not one possible +answer \ No newline at end of file diff --git a/1R4IzkWSNgI.txt b/1R4IzkWSNgI.txt new file mode 100644 index 0000000000000000000000000000000000000000..302a8b4291b6ebed21cc3f6dff2caec2b3dda9b1 --- /dev/null +++ b/1R4IzkWSNgI.txt @@ -0,0 +1,1435 @@ +align:start position:0% + +after our warmup we can now come to the + + align:start position:0% +after our warmup we can now come to the + + + align:start position:0% +after our warmup we can now come to the +real problem we have again a random + + align:start position:0% +real problem we have again a random + + + align:start position:0% +real problem we have again a random +variable theta with a known prior + + align:start position:0% +variable theta with a known prior + + + align:start position:0% +variable theta with a known prior +distribution and we're interested in a + + align:start position:0% +distribution and we're interested in a + + + align:start position:0% +distribution and we're interested in a +point estimate what will be different + + align:start position:0% +point estimate what will be different + + + align:start position:0% +point estimate what will be different +this time however is that we now have an + + align:start position:0% +this time however is that we now have an + + + align:start position:0% +this time however is that we now have an +observation and we also have a model of + + align:start position:0% +observation and we also have a model of + + + align:start position:0% +observation and we also have a model of +that observation as a conditional + + align:start position:0% +that observation as a conditional + + + align:start position:0% +that observation as a conditional +distribution given the value of the true + + align:start position:0% +distribution given the value of the true + + + align:start position:0% +distribution given the value of the true +parameter we observe a value of that + + align:start position:0% +parameter we observe a value of that + + + align:start position:0% +parameter we observe a value of that +random variable that values little X and + + align:start position:0% +random variable that values little X and + + + align:start position:0% +random variable that values little X and +on the basis of that value we would like + + align:start position:0% +on the basis of that value we would like + + + align:start position:0% +on the basis of that value we would like +to now come up with a point estimate of + + align:start position:0% +to now come up with a point estimate of + + + align:start position:0% +to now come up with a point estimate of +the unknown random variable theta how do + + align:start position:0% +the unknown random variable theta how do + + + align:start position:0% +the unknown random variable theta how do +we proceed we can of course use the + + align:start position:0% +we proceed we can of course use the + + + align:start position:0% +we proceed we can of course use the +Bayes rule and the Bayes rule is going + + align:start position:0% +Bayes rule and the Bayes rule is going + + + align:start position:0% +Bayes rule and the Bayes rule is going +to give us a distribution for the + + align:start position:0% +to give us a distribution for the + + + align:start position:0% +to give us a distribution for the +unknown random variable given the + + align:start position:0% +unknown random variable given the + + + align:start position:0% +unknown random variable given the +observation that we have obtained and + + align:start position:0% +observation that we have obtained and + + + align:start position:0% +observation that we have obtained and +that distribution could be discrete or + + align:start position:0% +that distribution could be discrete or + + + align:start position:0% +that distribution could be discrete or +continuous let me just plot something as + + align:start position:0% +continuous let me just plot something as + + + align:start position:0% +continuous let me just plot something as +if it's continuous and now that we have + + align:start position:0% +if it's continuous and now that we have + + + align:start position:0% +if it's continuous and now that we have +the posterior distribution of theta we + + align:start position:0% +the posterior distribution of theta we + + + align:start position:0% +the posterior distribution of theta we +would like to come up with a point + + align:start position:0% +would like to come up with a point + + + align:start position:0% +would like to come up with a point +estimate how do we do it remember our + + align:start position:0% +estimate how do we do it remember our + + + align:start position:0% +estimate how do we do it remember our +earlier conclusion if we do not have any + + align:start position:0% +earlier conclusion if we do not have any + + + align:start position:0% +earlier conclusion if we do not have any +observations if we live in a universe + + align:start position:0% +observations if we live in a universe + + + align:start position:0% +observations if we live in a universe +where we have a distribution of theta + + align:start position:0% +where we have a distribution of theta + + + align:start position:0% +where we have a distribution of theta +and we want a point estimate the optimal + + align:start position:0% +and we want a point estimate the optimal + + + align:start position:0% +and we want a point estimate the optimal +one the one that minimizes the mean + + align:start position:0% +one the one that minimizes the mean + + + align:start position:0% +one the one that minimizes the mean +squared error is the expected value of + + align:start position:0% +squared error is the expected value of + + + align:start position:0% +squared error is the expected value of +our random variable but now we live in a + + align:start position:0% +our random variable but now we live in a + + + align:start position:0% +our random variable but now we live in a +different universe in a universe where + + align:start position:0% +different universe in a universe where + + + align:start position:0% +different universe in a universe where +we have a conditional distribution of + + align:start position:0% +we have a conditional distribution of + + + align:start position:0% +we have a conditional distribution of +theta we want to minimize the + + align:start position:0% +theta we want to minimize the + + + align:start position:0% +theta we want to minimize the +conditional mean squared error because + + align:start position:0% +conditional mean squared error because + + + align:start position:0% +conditional mean squared error because +this is the mean squared error that + + align:start position:0% +this is the mean squared error that + + + align:start position:0% +this is the mean squared error that +applies to this conditional universe in + + align:start position:0% +applies to this conditional universe in + + + align:start position:0% +applies to this conditional universe in +which we have obtained a particular + + align:start position:0% +which we have obtained a particular + + + align:start position:0% +which we have obtained a particular +observation what is going to be the + + align:start position:0% +observation what is going to be the + + + align:start position:0% +observation what is going to be the +result of this minimization well this is + + align:start position:0% +result of this minimization well this is + + + align:start position:0% +result of this minimization well this is +a problem that's identical to the + + align:start position:0% +a problem that's identical to the + + + align:start position:0% +a problem that's identical to the +problem of minimizing this quantity + + align:start position:0% +problem of minimizing this quantity + + + align:start position:0% +problem of minimizing this quantity +except that now this problem is posed in + + align:start position:0% +except that now this problem is posed in + + + align:start position:0% +except that now this problem is posed in +a conditional universe so we just follow + + align:start position:0% +a conditional universe so we just follow + + + align:start position:0% +a conditional universe so we just follow +the same steps and obtain the same + + align:start position:0% +the same steps and obtain the same + + + align:start position:0% +the same steps and obtain the same +solution the solution is going to be the + + align:start position:0% +solution the solution is going to be the + + + align:start position:0% +solution the solution is going to be the +expected value of the unknown random + + align:start position:0% +expected value of the unknown random + + + align:start position:0% +expected value of the unknown random +variable except that now we live in a + + align:start position:0% +variable except that now we live in a + + + align:start position:0% +variable except that now we live in a +conditional universe and therefore we + + align:start position:0% +conditional universe and therefore we + + + align:start position:0% +conditional universe and therefore we +should take the relevant expected value + + align:start position:0% +should take the relevant expected value + + + align:start position:0% +should take the relevant expected value +which is the conditional expectation + + align:start position:0% +which is the conditional expectation + + + align:start position:0% +which is the conditional expectation +given the information that we have + + align:start position:0% +given the information that we have + + + align:start position:0% +given the information that we have +available in our hands so to summarize + + align:start position:0% +available in our hands so to summarize + + + align:start position:0% +available in our hands so to summarize +what we obtain is that the optimal + + align:start position:0% +what we obtain is that the optimal + + + align:start position:0% +what we obtain is that the optimal +estimate is the conditional expectation + + align:start position:0% +estimate is the conditional expectation + + + align:start position:0% +estimate is the conditional expectation +and this is a relation between numbers + + align:start position:0% +and this is a relation between numbers + + + align:start position:0% +and this is a relation between numbers +but if we want to think about it more + + align:start position:0% +but if we want to think about it more + + + align:start position:0% +but if we want to think about it more +abstractly we have designed an estimator + + align:start position:0% +abstractly we have designed an estimator + + + align:start position:0% +abstractly we have designed an estimator +which is based on a random variable + + align:start position:0% +which is based on a random variable + + + align:start position:0% +which is based on a random variable +capital X and calculates the expected + + align:start position:0% +capital X and calculates the expected + + + align:start position:0% +capital X and calculates the expected +value of our random variable that we're + + align:start position:0% +value of our random variable that we're + + + align:start position:0% +value of our random variable that we're +trying to estimate namely theta on the + + align:start position:0% +trying to estimate namely theta on the + + + align:start position:0% +trying to estimate namely theta on the +basis of X let us now continue with some + + align:start position:0% +basis of X let us now continue with some + + + align:start position:0% +basis of X let us now continue with some +observations remember that the expected + + align:start position:0% +observations remember that the expected + + + align:start position:0% +observations remember that the expected +value of theta minimizes this quantity + + align:start position:0% +value of theta minimizes this quantity + + + align:start position:0% +value of theta minimizes this quantity +and we can write this more explicitly in + + align:start position:0% +and we can write this more explicitly in + + + align:start position:0% +and we can write this more explicitly in +terms of the following inequality that + + align:start position:0% +terms of the following inequality that + + + align:start position:0% +terms of the following inequality that +if we use the expected value as an + + align:start position:0% +if we use the expected value as an + + + align:start position:0% +if we use the expected value as an +estimate the resulting mean squared + + align:start position:0% +estimate the resulting mean squared + + + align:start position:0% +estimate the resulting mean squared +error is less than or equal to the mean + + align:start position:0% +error is less than or equal to the mean + + + align:start position:0% +error is less than or equal to the mean +squared error that we would have + + align:start position:0% +squared error that we would have + + + align:start position:0% +squared error that we would have +obtained if we had used any other + + align:start position:0% +obtained if we had used any other + + + align:start position:0% +obtained if we had used any other +estimate see so this is a relation + + align:start position:0% +estimate see so this is a relation + + + align:start position:0% +estimate see so this is a relation +that's true for all see now let us take + + align:start position:0% +that's true for all see now let us take + + + align:start position:0% +that's true for all see now let us take +this inequality and translate it into + + align:start position:0% +this inequality and translate it into + + + align:start position:0% +this inequality and translate it into +our more interesting context where we + + align:start position:0% +our more interesting context where we + + + align:start position:0% +our more interesting context where we +have an observation available once more + + align:start position:0% +have an observation available once more + + + align:start position:0% +have an observation available once more +the conditional expectation minimizes + + align:start position:0% +the conditional expectation minimizes + + + align:start position:0% +the conditional expectation minimizes +the mean squared error let us write out + + align:start position:0% +the mean squared error let us write out + + + align:start position:0% +the mean squared error let us write out +explicitly what this means in a form + + align:start position:0% +explicitly what this means in a form + + + align:start position:0% +explicitly what this means in a form +analogous to what we wrote down earlier + + align:start position:0% +analogous to what we wrote down earlier + + + align:start position:0% +analogous to what we wrote down earlier +what it means is that the expected value + + align:start position:0% +what it means is that the expected value + + + align:start position:0% +what it means is that the expected value +of theta minus the estimate namely the + + align:start position:0% +of theta minus the estimate namely the + + + align:start position:0% +of theta minus the estimate namely the +conditional expectation squared in this + + align:start position:0% +conditional expectation squared in this + + + align:start position:0% +conditional expectation squared in this +conditional universe in which we live + + align:start position:0% +conditional universe in which we live + + + align:start position:0% +conditional universe in which we live +this is less than or equal to the mean + + align:start position:0% +this is less than or equal to the mean + + + align:start position:0% +this is less than or equal to the mean +squared error that we would have + + align:start position:0% +squared error that we would have + + + align:start position:0% +squared error that we would have +obtained if we had used any other + + align:start position:0% +obtained if we had used any other + + + align:start position:0% +obtained if we had used any other +estimate + + align:start position:0% + + + + align:start position:0% + +in the place of the conditional + + align:start position:0% +in the place of the conditional + + + align:start position:0% +in the place of the conditional +expectation so for any value G of X that + + align:start position:0% +expectation so for any value G of X that + + + align:start position:0% +expectation so for any value G of X that +we might have used the error would have + + align:start position:0% +we might have used the error would have + + + align:start position:0% +we might have used the error would have +been at least as large why am I using + + align:start position:0% +been at least as large why am I using + + + align:start position:0% +been at least as large why am I using +this notation G here let us go back to + + align:start position:0% +this notation G here let us go back to + + + align:start position:0% +this notation G here let us go back to +the bigger picture what we have is that + + align:start position:0% +the bigger picture what we have is that + + + align:start position:0% +the bigger picture what we have is that +we are obtaining a numerical value X we + + align:start position:0% +we are obtaining a numerical value X we + + + align:start position:0% +we are obtaining a numerical value X we +do some processing to it which + + align:start position:0% +do some processing to it which + + + align:start position:0% +do some processing to it which +corresponds to some function G and we + + align:start position:0% +corresponds to some function G and we + + + align:start position:0% +corresponds to some function G and we +come up with an estimate which is a + + align:start position:0% +come up with an estimate which is a + + + align:start position:0% +come up with an estimate which is a +function of the little X that we have + + align:start position:0% +function of the little X that we have + + + align:start position:0% +function of the little X that we have +observed so no matter what estimate we + + align:start position:0% +observed so no matter what estimate we + + + align:start position:0% +observed so no matter what estimate we +use the mean squared error is going to + + align:start position:0% +use the mean squared error is going to + + + align:start position:0% +use the mean squared error is going to +be at least as large as the mean squared + + align:start position:0% +be at least as large as the mean squared + + + align:start position:0% +be at least as large as the mean squared +error that we obtain if we use the + + align:start position:0% +error that we obtain if we use the + + + align:start position:0% +error that we obtain if we use the +conditional expectation now let us take + + align:start position:0% +conditional expectation now let us take + + + align:start position:0% +conditional expectation now let us take +this inequality here and write it in a + + align:start position:0% +this inequality here and write it in a + + + align:start position:0% +this inequality here and write it in a +more abstract form suppose that we have + + align:start position:0% +more abstract form suppose that we have + + + align:start position:0% +more abstract form suppose that we have +settled on some particular estimator and + + align:start position:0% +settled on some particular estimator and + + + align:start position:0% +settled on some particular estimator and +we want to compare this estimator with + + align:start position:0% +we want to compare this estimator with + + + align:start position:0% +we want to compare this estimator with +the expected value estimator then we are + + align:start position:0% +the expected value estimator then we are + + + align:start position:0% +the expected value estimator then we are +going to get the following inequality if + + align:start position:0% +going to get the following inequality if + + + align:start position:0% +going to get the following inequality if +we use the conditional expectation as an + + align:start position:0% +we use the conditional expectation as an + + + align:start position:0% +we use the conditional expectation as an +estimator in a conditional universe + + align:start position:0% +estimator in a conditional universe + + + align:start position:0% +estimator in a conditional universe +where we know the value of the random + + align:start position:0% +where we know the value of the random + + + align:start position:0% +where we know the value of the random +variable X the corresponding mean + + align:start position:0% +variable X the corresponding mean + + + align:start position:0% +variable X the corresponding mean +squared error is going to be less than + + align:start position:0% +squared error is going to be less than + + + align:start position:0% +squared error is going to be less than +or equal to the mean squared error + + align:start position:0% +or equal to the mean squared error + + + align:start position:0% +or equal to the mean squared error +obtained by the alternative estimator G + + align:start position:0% +obtained by the alternative estimator G + + + align:start position:0% +obtained by the alternative estimator G +what does this inequality say this + + align:start position:0% +what does this inequality say this + + + align:start position:0% +what does this inequality say this +inequality is simply an abstract version + + align:start position:0% +inequality is simply an abstract version + + + align:start position:0% +inequality is simply an abstract version +of the previous inequality the previous + + align:start position:0% +of the previous inequality the previous + + + align:start position:0% +of the previous inequality the previous +inequality is true for all little X here + + align:start position:0% +inequality is true for all little X here + + + align:start position:0% +inequality is true for all little X here +we have an inequality between random + + align:start position:0% +we have an inequality between random + + + align:start position:0% +we have an inequality between random +variables this random variable here is + + align:start position:0% +variables this random variable here is + + + align:start position:0% +variables this random variable here is +the random variable that takes this + + align:start position:0% +the random variable that takes this + + + align:start position:0% +the random variable that takes this +specific numerical value whenever + + align:start position:0% +specific numerical value whenever + + + align:start position:0% +specific numerical value whenever +capital X takes the value little X when + + align:start position:0% +capital X takes the value little X when + + + align:start position:0% +capital X takes the value little X when +X takes the value little X were + + align:start position:0% +X takes the value little X were + + + align:start position:0% +X takes the value little X were +auditioning on this event and when X is + + align:start position:0% +auditioning on this event and when X is + + + align:start position:0% +auditioning on this event and when X is +equal to little X this quantity takes on + + align:start position:0% +equal to little X this quantity takes on + + + align:start position:0% +equal to little X this quantity takes on +this particular numerical value and + + align:start position:0% +this particular numerical value and + + + align:start position:0% +this particular numerical value and +similarly on the other side this is a + + align:start position:0% +similarly on the other side this is a + + + align:start position:0% +similarly on the other side this is a +random variable that takes this + + align:start position:0% +random variable that takes this + + + align:start position:0% +random variable that takes this +particular numerical value whenever + + align:start position:0% +particular numerical value whenever + + + align:start position:0% +particular numerical value whenever +capital X is equal to little X now that + + align:start position:0% +capital X is equal to little X now that + + + align:start position:0% +capital X is equal to little X now that +we have an inequality between random + + align:start position:0% +we have an inequality between random + + + align:start position:0% +we have an inequality between random +variables actually between conditional + + align:start position:0% +variables actually between conditional + + + align:start position:0% +variables actually between conditional +expectations we can take expectations of + + align:start position:0% +expectations we can take expectations of + + + align:start position:0% +expectations we can take expectations of +both sides and we use the law of + + align:start position:0% +both sides and we use the law of + + + align:start position:0% +both sides and we use the law of +iterated expectations the expectation of + + align:start position:0% +iterated expectations the expectation of + + + align:start position:0% +iterated expectations the expectation of +a conditional expectation is an + + align:start position:0% +a conditional expectation is an + + + align:start position:0% +a conditional expectation is an +unconditional expectation so we obtain + + align:start position:0% + + + + align:start position:0% + +this as the expected value of this + + align:start position:0% +this as the expected value of this + + + align:start position:0% +this as the expected value of this +quantity and it's less than or equal to + + align:start position:0% +quantity and it's less than or equal to + + + align:start position:0% +quantity and it's less than or equal to +the expected value of this quantity + + align:start position:0% +the expected value of this quantity + + + align:start position:0% +the expected value of this quantity +using again the law of iterated + + align:start position:0% +using again the law of iterated + + + align:start position:0% +using again the law of iterated +expectations we obtain this relation + + align:start position:0% +expectations we obtain this relation + + + align:start position:0% +expectations we obtain this relation +here and what this inequality is saying + + align:start position:0% +here and what this inequality is saying + + + align:start position:0% +here and what this inequality is saying +is that the overall mean squared error + + align:start position:0% +is that the overall mean squared error + + + align:start position:0% +is that the overall mean squared error +if we use the conditional expectation + + align:start position:0% +if we use the conditional expectation + + + align:start position:0% +if we use the conditional expectation +now as an estimator is less than or + + align:start position:0% +now as an estimator is less than or + + + align:start position:0% +now as an estimator is less than or +equal to the mean squared error that we + + align:start position:0% +equal to the mean squared error that we + + + align:start position:0% +equal to the mean squared error that we +would obtain if we had used any other + + align:start position:0% +would obtain if we had used any other + + + align:start position:0% +would obtain if we had used any other +estimator so this inequality refers to + + align:start position:0% +estimator so this inequality refers to + + + align:start position:0% +estimator so this inequality refers to +the following picture we obtain an + + align:start position:0% +the following picture we obtain an + + + align:start position:0% +the following picture we obtain an +observation which is a random variable + + align:start position:0% +observation which is a random variable + + + align:start position:0% +observation which is a random variable +we process that random variable to come + + align:start position:0% +we process that random variable to come + + + align:start position:0% +we process that random variable to come +up with an estimator which is a function + + align:start position:0% +up with an estimator which is a function + + + align:start position:0% +up with an estimator which is a function +of the random variable that we observe + + align:start position:0% +of the random variable that we observe + + + align:start position:0% +of the random variable that we observe +and so is itself a random variable so + + align:start position:0% +and so is itself a random variable so + + + align:start position:0% +and so is itself a random variable so +when we use this random variable to + + align:start position:0% +when we use this random variable to + + + align:start position:0% +when we use this random variable to +estimate theta we obtain a certain mean + + align:start position:0% +estimate theta we obtain a certain mean + + + align:start position:0% +estimate theta we obtain a certain mean +squared error this is going to be at + + align:start position:0% +squared error this is going to be at + + + align:start position:0% +squared error this is going to be at +least as large as the mean squared error + + align:start position:0% +least as large as the mean squared error + + + align:start position:0% +least as large as the mean squared error +that we obtain if we use the conditional + + align:start position:0% +that we obtain if we use the conditional + + + align:start position:0% +that we obtain if we use the conditional +expectation as our estimator + + align:start position:0% +expectation as our estimator + + + align:start position:0% +expectation as our estimator +so to summarize the conditional + + align:start position:0% +so to summarize the conditional + + + align:start position:0% +so to summarize the conditional +expectation of theta viewed as a random + + align:start position:0% +expectation of theta viewed as a random + + + align:start position:0% +expectation of theta viewed as a random +variable + + align:start position:0% +variable + + + align:start position:0% +variable +as an estimator what we call the LMS + + align:start position:0% +as an estimator what we call the LMS + + + align:start position:0% +as an estimator what we call the LMS +estimator of theta has the property that + + align:start position:0% +estimator of theta has the property that + + + align:start position:0% +estimator of theta has the property that +it minimizes the mean squared error over + + align:start position:0% +it minimizes the mean squared error over + + + align:start position:0% +it minimizes the mean squared error over +all possible alternative estimators so + + align:start position:0% +all possible alternative estimators so + + + align:start position:0% +all possible alternative estimators so +if you want to design this box using + + align:start position:0% +if you want to design this box using + + + align:start position:0% +if you want to design this box using +some other function G you're going to + + align:start position:0% +some other function G you're going to + + + align:start position:0% +some other function G you're going to +obtain a mean squared error that's going + + align:start position:0% +obtain a mean squared error that's going + + + align:start position:0% +obtain a mean squared error that's going +to be no better than what you obtain if + + align:start position:0% +to be no better than what you obtain if + + + align:start position:0% +to be no better than what you obtain if +you were to use the conditional + + align:start position:0% +you were to use the conditional + + + align:start position:0% +you were to use the conditional +expectation \ No newline at end of file diff --git a/1jDBM9UM9xk.txt b/1jDBM9UM9xk.txt new file mode 100644 index 0000000000000000000000000000000000000000..900294257426c0cc86f1d061ee51ea3d98bb49b5 --- /dev/null +++ b/1jDBM9UM9xk.txt @@ -0,0 +1,2399 @@ +The following content is +provided under a Creative + +Commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high quality educational +resources for free. + +To make a donation or view +additional materials from + +hundreds of MIT courses, visit +MIT OpenCourseWare at + +ocw.mit.edu. + +PROFESSOR: It involves real +phenomena out there. + +So we have real stuff +that happens. + +So it might be an arrival +process to a bank that we're + +trying to model. + +This is a reality, but +this is what we have + +been doing so far. + +We have been playing +with models of + +probabilistic phenomena. + +And somehow we need to +tie the two together. + +The way these are tied is that +we observe the real world and + +this gives us data. + +And then based on these data, we +try to come up with a model + +of what exactly is going on. + +For example, for an arrival +process, you might ask the + +model in question, is my arrival +process Poisson or is + +it something different? + +If it is Poisson, what is the +rate of the arrival process? + +Once you come up with your model +and you come up with the + +parameters of the model, then +you can use it to make + +predictions about reality or to +figure out certain hidden + +things, certain hidden aspects +of reality, that you do not + +observe directly, but you try +to infer what they are. + +So that's where the usefulness +of the model comes in. + +Now this field is of course +tremendously useful. + +And it shows up pretty +much everywhere. + +So we talked about the polling +examples in the + +last couple of lectures. + +This is, of course, a +real application. + +You sample and on the basis of +the sample that you have, you + +try to make some inferences +about, let's say, the + +preferences in a given +population. + +Let's say in the medical field, +you want to try whether + +a certain drug makes a +difference or not. + +So people would do medical +trials, get some results, and + +then from the data somehow you +need to make sense of them and + +make a decision. + +Is the new drug useful +or is it not? + +How do we go systematically +about the + +question of this type? + +A sexier, more recent topic, +there's this famous Netflix + +competition where Netflix gives +you a huge table of + +movies and people. + +And people have rated the +movies, but not everyone has + +watched all of the +movies in there. + +You have some of the ratings. + +For example, this person gave a +4 to that particular movie. + +So you get the table that's +partially filled. + +And the Netflix asks +you to make + +recommendations to people. + +So this means trying to guess. + +This person here, how much +would they like this + +particular movie? + +And you can start thinking, +well, maybe this person has + +given somewhat similar ratings +with another person. + +And if that other person has +also seen that movie, maybe + +the rating of that other +person is relevant. + +But of course it's a lot more +complicated than that. + +And this has been a serious +competition where people have + +been using every heavy, wet +machinery that there is in + +statistics, trying to +come up with good + +recommendation systems. + +Then the other people, of +course, are trying to analyze + +financial data. + +Somebody gives you the sequence +of the values, let's + +say of the SMP index. + +You look at something like this + +and you can ask questions. + +How do I model these data using +any of the models that + +we have in our bag of tools? + +How can I make predictions about +what's going to happen + +afterwards, and so on? + +On the engineering side, +anywhere where you have noise + +inference comes in. + +Signal processing, in +some sense, is just + +an inference problem. + +You observe signals that are +noisy and you try to figure + +out exactly what's happening +out there or what kind of + +signal has been sent. + +Maybe the beginning of the field +could be traced a few + +hundred years ago where people +would observe, make + +astronomical observations +of the position of the + +planets in the sky. + +They would have some beliefs +that perhaps the orbits of + +planets is an ellipse. + +Or if it's a comet, maybe it's +a parabola, hyperbola, don't + +know what it is. + +But they would have +a model of that. + +But, of course, astronomical +measurements would not be + +perfectly exact. + +And they would try to find the +curve that fits these data. + +How do you go about choosing +this particular curve on the + +base of noisy data and +try to do it in a + +somewhat principled way? + +OK, so questions of this +type-- clearly the + +applications are all +over the place. + +But how is this related +conceptually with what we have + +been doing so far? + +What's the relation between the +field of inference and the + +field of probability +as we have been + +practicing until now? + +Well, mathematically speaking, +what's going to happen in the + +next few lectures could be just +exercises or homework + +problems in the class in based +on what we have done so far. + +That means you're not going +to get any new facts about + +probability theory. + +Everything we're going to do +will be simple applications of + +things that you already +do know. + +So in some sense, statistics +and inference is just an + +applied exercise +in probability. + +But actually, things are +not that simple in + +the following sense. + +If you get a probability +problem, + +there's a correct answer. + +There's a correct solution. + +And that correct solution +is unique. + +There's no ambiguity. + +The theory of probability has +clearly defined rules. + +These are the axioms. + +You're given some information +about probability + +distributions. + +You're asked to calculate +certain other things. + +There's no ambiguity. + +Answers are always unique. + +In statistical questions, it's +no longer the case that the + +question has a unique answer. + +If I give you data and I ask +you what's the best way of + +estimating the motion of that +planet, reasonable people can + +come up with different +methods. + +And reasonable people will try +to argue that's my method has + +these desirable properties but +somebody else may say, here's + +another method that has certain +desirable properties. + +And it's not clear what +the best method is. + +So it's good to have some +understanding of what the + +issues are and to know at least +what is the general + +class of methods that one tries +to consider, how does + +one go about such problems. + +So we're going to see +lots and lots of + +different inference methods. + +We're not going to tell +you that one is + +better than the other. + +But it's important to understand +what are the + +concepts between those +different methods. + +And finally, statistics can +be misused really badly. + +That is, one can come up with +methods that you think are + +sound, but in fact they're +not quite that. + +I will bring some examples next +time and talk a little + +more about this. + +So, they want to say, you have +some data, you want to make + +some inference from them, what +many people will do is to go + +to Wikipedia, find a statistical +test that they + +think it applies to that +situation, plug in numbers, + +and present results. + +Are the conclusions that they +get really justified or are + +they misusing statistical +methods? + +Well, too many people actually +do misuse statistics and + +conclusions that people +get are often false. + +So it's important to, besides +just being able to copy + +statistical tests and use them, +to understand what are + +the assumptions between the +different methods and what + +kind of guarantees they +have, if any. + +All right, so we'll try to do a +quick tour through the field + +of inference in this lecture and +the next few lectures that + +we have left this semester and +try to highlight at the very + +high level the main concept +skills, and + +techniques that come in. + +Let's start with some +generalities and some general + +statements. + +One first statement is that +statistics or inference + +problems come up in very +different guises. + +And they may look as if they are +of very different forms. + +Although, at some fundamental +level, the basic issues turn + +out to be always pretty +much the same. + +So let's look at this example. + +There's an unknown signal +that's being sent. + +It's sent through some medium, +and that medium just takes the + +signal and amplifies it +by a certain number. + +So you can think of +somebody shouting. + +There's the air out there. + +What you shouted will be +attenuated through the air + +until it gets to a receiver. + +And that receiver then observes +this, but together + +with some random noise. + +Here I meant S. S is the signal +that's being sent. + +And what you observe is an X. + +You observe X, so what kind +of inference problems + +could we have here? + +In some cases, you want to build +a model of the physical + +phenomenon that you're +dealing with. + +So for example, you don't know +the attenuation of your signal + +and you try to find out what +this number is based on the + +observations that you have. + +So the way this is done in +engineering systems is that + +you design a certain signal, you +know what it is, you shout + +a particular word, and then +the receiver listens. + +And based on the intensity of +the signal that they get, they + +try to make a guess about A. So +you don't know A, but you + +know S. And by observing X, +you get some information + +about what A is. + +So in this case, you're trying +to build a model of the medium + +through which your signal +is propagating. + +So sometimes one would call +problems of this kind, let's + +say, system identification. + +In a different version of an +inference problem that comes + +with this picture, you've +done your modeling. + +You know your A. You know the +medium through which the + +signal is going, but it's +a communication system. + +This person is trying +to communicate + +something to that person. + +So you send the signal S, but +that person receives a noisy + +version of S. So that person +tries to reconstruct S based + +on X. + +So in both cases, we have a +linear relation between X and + +the unknown quantity. + +In one version, A is the unknown +and we know S. In the + +other version, A is known, +and so we try to infer S. + +Mathematically, you can see that +this is essentially the + +same kind of problem +in both cases. + +Although, the kind of practical +problem that you're + +trying to solve is a +little different. + +So we will not be making any +distinctions between problems + +of the model building type as +opposed to models where you + +try to estimate some unknown +signal and so on. + +Because conceptually, the tools +that one uses for both + +types of problems are +essentially the same. + +OK, next a very useful +classification + +of inference problems-- + +the unknown quantity that you're +trying to estimate + +could be either a discrete +one that takes a + +small number of values. + +So this could be discrete +problems, such as the airplane + +radar problem we encountered +back a long + +time ago in this class. + +So there's two possibilities-- + +an airplane is out there or an +airplane is not out there. + +And you're trying to +make a decision + +between these two options. + +Or you can have other problems +would you have, let's say, + +four possible options. + +You don't know which one is +true, but you get data and you + +try to figure out which +one is true. + +In problems of these kind, +usually you want to make a + +decision based on your data. + +And you're interested in the +probability of making a + +correct decision. + +You would like that +probability to + +be as high as possible. + +Estimation problems are +a little different. + +Here you have some continuous +quantity that's not known. + +And you try to make a good +guess of that quantity. + +And you would like your guess to +be as close as possible to + +the true quantity. + +So the polling problem +was of this type. + +There was an unknown fraction +f of the population that had + +some property. + +And you try to estimate f as +accurately as you can. + +So the distinction here is that +usually here the unknown + +quantity takes on discrete +set of values. + +Here the unknown quantity +takes a + +continuous set of values. + +Here we're interested in the +probability of error. + +Here we're interested in +the size of the error. + +Broadly speaking, most inference +problems fall either + +in this category or +in that category. + +Although, if you want to +complicate life, you can also + +think or construct problems +where both of these aspects + +are simultaneously present. + +OK, finally since we're in +classification mode, there is + +a very big, important dichotomy +into how one goes + +about inference problems. + +And here there's two +fundamentally different + +philosophical points of view, +which is how do we model the + +quantity that is unknown? + +In one approach, you say there's +a certain quantity + +that has a definite value. + +It just happens that +they don't know it. + +But it's a number. + +There's nothing random +about it. + +So think of trying to estimate +some physical quantity. + +You're making measurements, you +try to estimate the mass + +of an electron, which +is a sort of + +universal physical constant. + +There's nothing random +about it. + +It's a fixed number. + +You get data, because you have +some measuring apparatus. + +And that measuring apparatus, +depending on what that results + +that you get are affected by the +true mass of the electron, + +but there's also some noise. + +You take the data out of your +measuring apparatus and you + +try to come up with +some estimate of + +that quantity theta. + +So this is definitely a +legitimate picture, but the + +important thing in this picture +is that this theta is + +written as lowercase. + +And that's to make the point +that it's a real number, not a + +random variable. + +There's a different +philosophical approach which + +says, well, anything that I +don't know I should model it + +as a random variable. + +Yes, I know. + +The mass of the electron +is not really random. + +It's a constant. + +But I don't know what it is. + +I have some vague sense, +perhaps, what it is perhaps + +because of the experiments +that some other + +people carried out. + +So perhaps I have a prior +distribution on the possible + +values of Theta. + +And that prior distribution +doesn't mean that the nature + +is random, but it's more of a +subjective description of my + +subjective beliefs of where do +I think this constant number + +happens to be. + +So even though it's not truly +random, I model my initial + +beliefs before the experiment +starts. + +In terms of a prior +distribution, I view it as a + +random variable. + +Then I observe another related +random variable through some + +measuring apparatus. + +And then I use this again +to create an estimate. + +So these two pictures +philosophically are very + +different from each other. + +Here we treat the unknown +quantities as unknown numbers. + +Here we treat them as +random variables. + +When we treat them as a random +variables, then we know pretty + +much already what we +should be doing. + +We should just use +the Bayes rule. + +Based on X, find +the conditional + +distribution of Theta. + +And that's what we will be doing +mostly over this lecture + +and the next lecture. + +Now in both cases, what you end +up getting at the end is + +an estimate. + +But actually, that estimate is +what kind of object is it? + +It's a random variable +in both cases. + +Why? + +Even in this case where +theta was a + +constant, my data are random. + +I do my data processing. + +So I calculate a function +of the data, the + +data are random variables. + +So out here we output something +which is a function + +of a random variable. + +So this quantity here +will be also random. + +It's affected by the noise and +the experiment that I have + +been doing. + +That's why these estimators +will be denoted + +by uppercase Thetas. + +And we will be using hats. + +Hat, usually in estimation, +means + +an estimate of something. + +All right, so this is +the big picture. + +We're going to start with +the Bayesian version. + +And then the last few lectures +we're going to talk about the + +non-Bayesian version or +the classical one. + +By the way, I should say that +statisticians have been + +debating fiercely for 100 years +whether the right way to + +approach statistics is to go +the classical way or the + +Bayesian way. + +And there have been tides going +back and forth between + +the two sides. + +These days, Bayesian methods +tend to become a little more + +popular for various reasons. + +We're going to come back +to this later. + +All right, so in Bayesian +estimation, what we got in our + +hands is Bayes rule. + +And if you have Bayes rule, +there's not a lot + +that's left to do. + +We have different forms of the +Bayes rule, depending on + +whether we're dealing with +discrete data, And discrete + +quantities to estimate, or +continuous data, and so on. + +In the hypothesis testing +problem, the unknown quantity + +Theta is discrete. + +So in both cases here, +we have a P of Theta. + +We obtain data, the X's. + +And on the basis of the X that +we observe, we can calculate + +the posterior distribution +of Theta, given the data. + +So to use Bayesian inference, +what do we start with? + +We start with some priors. + +These are our initial +beliefs about what + +Theta that might be. + +That's before we do +the experiment. + +We have a model of the +experimental aparatus. + +And the model of the +experimental apparatus tells + +us if this Theta is true, I'm +going to see X's of that kind. + +If that other Theta is true, I'm +going to see X's that they + +are somewhere else. + +That models my apparatus. + +And based on that knowledge, +once I observe I have these + +two functions in my hands, we +have already seen that if you + +know those two functions, you +can also calculate the + +denominator here. + +So all of these functions are +available, so you can compute, + +you can find a formula for +this function as well. + +And as soon as you observe the +data, that X's, you plug in + +here the numerical value +of those X's. + +And you get a function +of Theta. + +And this is the posterior +distribution of Theta, given + +the data that you have seen. + +So you've already done +a fair number of + +exercises of these kind. + +So we not say more about this. + +And there's a similar formula as +you know for the case where + +we have continuous data. + +If the X's are continuous random +variable, then the + +formula is the same, except +that X's are described by + +densities instead of being +described by a probability + +mass functions. + +OK, now if Theta is continuous, +then we're dealing + +with estimation problems. + +But the story is once +more the same. + +You're going to use the Bayes +rule to come up with the + +posterior density of Theta, +given the data + +that you have observed. + +Now just for the sake of the +example, let's come back to + +this picture here. + +Suppose that something is flying +in the air, and maybe + +this is just an object in the +air close to the Earth. + +So because of gravity, the +trajectory that it's going to + +follow it's going to +be a parabola. + +So this is the general equation +of a parabola. + +Zt is the position of my +objects at time t. + +But I don't know exactly +which parabola it is. + +So the parameters of the +parabola are unknown + +quantities. + +What I can do is to go and +measure the position of my + +objects at different times. + +But unfortunately, my +measurements are noisy. + +What I want to do is to model +the motion of my object. + +So I guess in the picture, the +axis would be t going this way + +and Z going this way. + +And on the basis of the +data that they get, + +these are my X's. + +I want to figure +out the Thetas. + +That is, I want to figure +out the exact + +equation of this parabola. + +Now if somebody gives you +probability distributions for + +Theta, these would +be your priors. + +So this is given. + +We need the conditional +distribution of the X's given + +the Thetas. + +Well, we have the conditional +distribution of Z, given the + +Thetas from this equation. + +And then by playing with this +equation, you can also find + +how is X distributed if Theta +takes a particular value. + +So you do have all of the +densities that you might need. + +And you can apply +the Bayes rule. + +And at the end, your end result +would be a formula for + +the distribution of Theta, +given to the X + +that you have observed-- + +except for one sort of +computation, or to make things + +more interesting. + +Instead of these X's and Theta's +being single random + +variables that we have here, +typically those X's and + +Theta's will be +multi-dimensional random + +variables or will correspond +to multiple ones. + +So this little Theta here +actually stands for a triplet + +of Theta0, Theta1, and Theta2. + +And that X here stands here for +the entire sequence of X's + +that we have observed. + +So in reality, the object that +you're going to get at to the + +end after inference is done is +a function that you plug in + +the values of the data and you +get the function of the + +Theta's that tells you the +relative likelihoods of + +different Theta triplets. + +So what I'm saying is that this +is no harder than the + +problems that you have dealt +with so far, except perhaps + +for the complication that's +usually in interesting + +inference problems. + +Your Theta's and X's are often +the vectors of random + +variables instead of individual +random variables. + +Now if you are to do estimation +in a case where you + +have discrete data, again the +situation is no different. + +We still have a Bayes rule of +the same kind, except that + +densities gets replaced +by PMF's. + +If X is discrete, you put a P +here instead of putting an f. + +So an example of an estimation +problem with discrete data is + +similar to the polling +problem. + +You have a coin. + +It has an unknown +parameter Theta. + +This is the probability +of obtaining heads. + +You flip the coin many times. + +What can you tell me about +the true value of Theta? + +A classical statistician, at +this point, would say, OK, I'm + +going to use an estimator, +the most reasonable + +one, which is this. + +How many heads did they +obtain in n trials? + +Divide by the total +number of trials. + +This is my estimate of +the bias of my coin. + +And then the classical +statistician would continue + +from here and try to prove some +properties and argue that + +this estimate is a good one. + +For example, we have the weak +law of large numbers that + +tells us that this particular +estimate converges in + +probability to the +true parameter. + +This is a kind of guarantee +that's useful to have. + +And the classical statistician +would pretty much close the + +subject in this way. + +What would the Bayesian +person do differently? + +The Bayesian person would start +by assuming a prior + +distribution of Theta. + +Instead of treating Theta as +an unknown constant, they + +would say that Theta would speak +randomly or pretend that + +it would speak randomly +and assume a + +distribution on Theta. + +So for example, if you don't +know they need anything more, + +you might assume that any value +for the bias of the coin + +is as likely as any other value +of the bias of the coin. + +And this way so the probability +distribution + +that's uniform. + +Or if you have a little more +faith in the manufacturing + +processes that's created that +coin, you might choose your + +prior to be a distribution +that's centered around 1/2 and + +sits fairly narrowly centered +around 1/2. + +That would be a prior +distribution in which you say, + +well, I believe that the +manufacturer tried to make my + +coin to be fair. + +But they often makes some +mistakes, so it's going to be, + +I believe, it's approximately +1/2 but not quite. + +So depending on your beliefs, +you would choose an + +appropriate prior for the +distribution of Theta. + +And then you would use the +Bayes rule to find the + +probabilities of different +values of Theta, based on the + +data that you have observed. + +So no matter which version of +the Bayes rule that you use, + +the end product of the Bayes +rule is going to be either a + +plot of this kind or a +plot of that kind. + +So what am I plotting here? + +This axis is the Theta axis. + +These are the possible values +of the unknown quantity that + +we're trying to estimate. + +In the continuous +case, theta is a + +continuous random variable. + +I obtain my data. + +And I plot for the posterior +probability distribution after + +observing my data. + +And I'm plotting here the +probability density for Theta. + +So this is a plot +of that density. + +In the discrete case, theta can +take finitely many values + +or a discrete set of values. + +And for each one of those +values, I'm telling you how + +likely is that the value to be +the correct one, given the + +data that I have observed. + +And in general, what you would +go back to your boss and + +report after you've done all +your inference work would be + +either a plot of this kinds +or of that kind. + +So you go to your boss +who asks you, what is + +the value of Theta? + +And you say, well, I only +have limited data. + +That I don't know what it is. + +It could be this, with +so much probability. + +There's probability. + +OK, let's throw in some +numbers here. + +There's probability 0.3 that +Theta is this value. + +There's probability 0.2 that +Theta is this value, 0.1 that + +it's this one, 0.1 that it's +this one, 0.2 that it's that + +one, and so on. + +OK, now bosses often want +simple answers. + +They say, OK, you're +talking too much. + +What do you think Theta is? + +And now you're forced +to make a decision. + +If that was the situation and +you have to make a decision, + +how would you make it? + +Well, I'm going to make a +decision that's most likely to + +be correct. + +If I make this decision, +what's going to happen? + +Theta is this value with +probability 0.2, which means + +there's probably 0.8 that +they make an error + +if I make that guess. + +If I make that decision, this +decision has probably 0.3 of + +being the correct one. + +So I have probably +of error 0.7. + +So if you want to just maximize +the probability of + +giving the correct decision, or +if you want to minimize the + +probability of making an +incorrect decision, what + +you're going to choose to report +is that value of Theta + +for which the probability +is highest. + +So in this case, I would +choose to report this + +particular value, the most +likely value of Theta, given + +what I have observed. + +And that value is called them +maximum a posteriori + +probability estimate. + +It's going to be this +one in our case. + +So picking the point in the +posterior PMF that has the + +highest probability. + +That's the reasonable +thing to do. + +This is the optimal thing to do +if you want to minimize the + +probability of an incorrect +inference. + +And that's what people do +usually if they need to report + +a single answer, if they need +to report a single decision. + +How about in the estimation +context? + +If that's what you know about +Theta, Theta could be around + +here, but there's also some +sharp probability that it is + +around here. + +What's the single answer that +you would give to your boss? + +One option is to use the same +philosophy and say, OK, I'm + +going to find the Theta at which +this posterior density + +is highest. + +So I would pick this point +here and report this + +particular Theta. + +So this would be my Theta, +again, Theta MAP, the Theta + +that has the highest a +posteriori probability, just + +because it corresponds to +the peak of the density. + +But in this context, the +maximum a posteriori + +probability theta was the +one that was most + +likely to be true. + +In the continuous case, you +cannot really say that this is + +the most likely value +of Theta. + +In a continuous setting, any +value of Theta has zero + +probability, so when we +talk about densities. + +So it's not the most likely. + +It's the one for which the +density, so the probabilities + +of that neighborhoods, +are highest. + +So the rationale for picking +this particular estimate in + +the continuous case is much +less compelling than the + +rationale that we had in here. + +So in this case, reasonable +people might choose different + +quantities to report. + +And the very popular one would +be to report instead the + +conditional expectation. + +So I don't know quite +what Theta is. + +Given the data that I have, +Theta has this distribution. + +Let me just report the average +over that distribution. + +Let me report to the center +of gravity of this figure. + +And in this figure, the center +of gravity would probably be + +somewhere around here. + +And that would be a different +estimate that you + +might choose to report. + +So center of gravity is +something around here. + +And this is a conditional +expectation of Theta, given + +the data that you have. + +So these are two, in some sense, +fairly reasonable ways + +of choosing what to report +to your boss. + +Some people might choose +to report this. + +Some people might choose +to report that. + +And a priori, if there's no +compelling reason why one + +would be preferable than other +one, unless you set some rules + +for the game and you describe +a little more precisely what + +your objectives are. + +But no matter which one you +report, a single answer, a + +point estimate, doesn't really +tell you the whole story. + +There's a lot more information +conveyed by this posterior + +distribution plot than +any single number + +that you might report. + +So in general, you may wish to +convince your boss that's it's + +worth their time to look at the +entire plot, because that + +plot sort of covers all +the possibilities. + +It tells your boss most likely +we're in that range, but + +there's also a distinct change +that our Theta happens to lie + +in that range. + +All right, now let us try to +perhaps differentiate between + +these two and see under what +circumstances this one might + +be the better estimate +to perform. + +Better with respect to what? + +We need some rules. + +So we're going to throw +in some rules. + +As a warm up, we're going to +deal with the problem of + +making an estimation if you +had no information at all, + +except for a prior +distribution. + +So this is a warm up for what's +coming next, which + +would be estimation that takes +into account some information. + +So we have a Theta. + +And because of your subjective +beliefs or models by others, + +you believe that Theta is +uniformly distributed between, + +let's say, 4 and 10. + +You want to come up with +a point estimate. + +Let's try to look +for an estimate. + +Call it c, in this case. + +I want to pick a number +with which to estimate + +the value of Theta. + +I will be interested in the size +of the error that I make. + +And I really dislike large +errors, so I'm going to focus + +on the square of the error +that they make. + +So I pick c. + +Theta that has a random value +that I don't know. + +But whatever it is, once it +becomes known, it results into + +a squared error between +what it is and what I + +guessed that it was. + +And I'm interested in making +a small air on the average, + +where the average is taken +with respect to all the + +possible and unknown +values of Theta. + +So the problem, this is a least +squares formulation of + +the problem, where we +try to minimize the + +least squares errors. + +How do you find the optimal c? + +Well, we take that expression +and expand it. + +And it is, using linearity +of expectations-- + +square minus 2c expected +Theta plus c squared-- + +that's the quantity that +we want to minimize, + +with respect to c. + +To do the minimization, take the +derivative with respect to + +c and set it to 0. + +So that differentiation gives us +from here minus 2 expected + +value of Theta plus +2c is equal to 0. + +And the answer that you get by +solving this equation is that + +c is the expected +value of Theta. + +So when you do this +optimization, you find that + +the optimal estimate, the +things you should be + +reporting, is the expected +value of Theta. + +So in this particular example, +you would choose your estimate + +c to be just the middle +of these values, + +which would be 7. + +OK, and in case your +boss asks you, how + +good is your estimate? + +How big is your error +going to be? + +What you could report is the +average size of the estimation + +error that you are making. + +We picked our estimates to be +the expected value of Theta. + +So for this particular way that +I'm choosing to do my + +estimation, this is the mean +squared error that I get. + +And this is a familiar +quantity. + +It's just the variance +of the distribution. + +So the expectation is that +best way to estimate a + +quantity, if you're interested +in the mean squared error. + +And the resulting mean squared +error is the variance itself. + +How will this story change if +we now have data as well? + +Now having data means that +we can compute posterior + +distributions or conditional +distributions. + +So we get transported into a new +universe where instead the + +working with the original +distribution of Theta, the + +prior distribution, now we work +with the condition of + +distribution of Theta, +given the data + +that we have observed. + +Now remember our old slogan that +conditional models and + +conditional probabilities are +no different than ordinary + +probabilities, except that we +live now in a new universe + +where the new information has +been taken into account. + +So if you use that philosophy +and you're asked to minimize + +the squared error but now that +you live in a new universe + +where X has been fixed to +something, what would the + +optimal solution be? + +It would again be the +expectation of theta, but + +which expectation? + +It's the expectation which +applies in the new conditional + +universe in which we +live right now. + +So because of what we did +before, by the same + +calculation, we would find that +the optimal estimates is + +the expected value of X of +Theta, but the optimal + +estimate that takes +into account the + +information that we have. + +So the conclusion, once you get +your data, if you want to + +minimize the mean squared error, +you should just report + +the conditional estimation of +this unknown quantity based on + +the data that you have. + +So the picture here is that +Theta is unknown. + +You have your apparatus that +creates measurements. + +So this creates an X. You take +an X, and here you have a box + +that does calculations. + +It does calculations and it +spits out the conditional + +expectation of Theta, given the +particular data that you + +have observed. + +And what we have done in this +class so far is, to some + +extent, developing the +computational tools and skills + +to do with this particular +calculation-- + +how to calculate the posterior +density for Theta and how to + +calculate expectations, +conditional expectations. + +So in principle, we know +how to do this. + +In principle, we can program a +computer to take the data and + +to spit out condition +expectations. + +Somebody who doesn't think like +us might instead design a + +calculating machine that does +something differently and + +produces some other estimate. + +So we went through this argument +and we decided to + +program our computer to +calculate conditional + +expectations. + +Somebody else came up with some +other crazy idea for how + +to estimate the random +variable. + +They came up with some function +g and the programmed + +it, and they designed a machine +that estimates Theta's + +by outputting a certain +g of X. + +That could be an alternative +estimator. + +Which one is better? + +Well, we convinced ourselves +that this is the optimal one + +in a universe where we have +fixed the particular + +value of the data. + +So what we have proved so far +is a relation of this kind. + +In this conditional universe, +the mean squared + +error that I get-- + +I'm the one who's using +this estimator-- + +is less than or equal than the +mean squared error that this + +person will get, the person +who uses that estimator. + +For any particular value of +the data, I'm going to do + +better than the other person. + +Now the data themselves +are random. + +If I average over all possible +values of the data, I should + +still be better off. + +If I'm better off for any +possible value X, then I + +should be better off on the +average over all possible + +values of X. + +So let us average both sides of +this quantity with respect + +to the probability distribution +of X. If you want + +to do it formally, you can write +this inequality between + +numbers as an inequality between +random variables. + +And it tells that no matter +what that random variable + +turns out to be, this quantity +is better than that quantity. + +Take expectations of both +sides, and you get this + +inequality between expectations +overall. + +And this last inequality tells +me that the person who's using + +this estimator who produces +estimates according to this + +machine will have a mean squared +estimation error + +that's less than or equal to +the estimation error that's + +produced by the other person. + +In a few words, the conditional +expectation + +estimator is the optimal +estimator. + +It's the ultimate estimating +machine. + +That's how you should solve +estimation problems and report + +a single value. + +If you're forced to report a +single value and if you're + +interested in estimation +errors. + +OK, while we could have told you +that story, of course, a + +month or two ago, this is really +about interpretation -- + +about realizing that conditional +expectations have + +a very nice property. + +But other than that, any +probabilistic skills that come + +into this business are just the +probabilistic skills of + +being able to calculate +conditional expectations, + +which you already +know how to do. + +So conclusion, all of optimal +Bayesian estimation just means + +calculating and reporting +conditional expectations. + +Well, if the world were that +simple, then statisticians + +wouldn't be able to find jobs +if life is that simple. + +So real life is not +that simple. + +There are complications. + +And that perhaps makes their +life a little more + +interesting. + +OK, one complication is that we +would deal with the vectors + +instead of just single +random variables. + +I use the notation here +as if X was a + +single random variable. + +In real life, you get +several data. + +Does our story change? + +Not really, same argument-- + +given all the data that you +have observed, you should + +still report the conditional +expectation of Theta. + +But what kind of work does it +take in order to report this + +conditional expectation? + +One issue is that you need to +cook up a plausible prior + +distribution for Theta. + +How do you do that? + +In a given application , this +is a bit of a judgment call, + +what prior would you +be working with. + +And there's a certain +skill there of not + +making silly choices. + +A more pragmatic, practical +issue is that this is a + +formula that's extremely nice +and compact and simple that + +you can write with +minimal ink. + +But the behind it there could +be hidden a huge amount of + +calculation. + +So doing any sort of +calculations that involve + +multiple random variables really +involves calculating + +multi-dimensional integrals. + +And the multi-dimensional +integrals are hard to compute. + +So implementing actually this +calculating machine here may + +not be easy, might be +complicated computationally. + +It's also complicated in terms +of not being able to derive + +intuition about it. + +So perhaps you might want to +have a simpler version, a + +simpler alternative to this +formula that's easier to work + +with and easier to calculate. + +We will be talking about +one such simpler + +alternative next time. + +So again, to conclude, at +the high level, Bayesian + +estimation is very, very simple, +given that you have + +mastered everything that +has happened in + +this course so far. + +There are certain practical +issues and it's also good to + +be familiar with the concepts +and the issues that in + +general, you would prefer to +report that complete posterior + +distribution. + +But if you're forced to report a +point estimate, then there's + +a number of reasonable +ways to do it. + +And perhaps the most reasonable +one is to just the + +report the conditional +expectation itself. \ No newline at end of file diff --git a/1pkoBetgo7s.txt b/1pkoBetgo7s.txt new file mode 100644 index 0000000000000000000000000000000000000000..149d08bd89ffc870f0a6286adff3a3c98d76c1c4 --- /dev/null +++ b/1pkoBetgo7s.txt @@ -0,0 +1,12419 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +to view additional materials from + + align:start position:0% +to view additional materials from + + + align:start position:0% +to view additional materials from +hundreds of MIT courses visit MIT open + + align:start position:0% +hundreds of MIT courses visit MIT open + + + align:start position:0% +hundreds of MIT courses visit MIT open +courseware at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu good so before we start do + + align:start position:0% +ocw.mit.edu good so before we start do + + + align:start position:0% +ocw.mit.edu good so before we start do +you have any questions on what we did uh + + align:start position:0% + + + + align:start position:0% + +before + + align:start position:0% + + + + align:start position:0% + +okay so we have + + align:start position:0% +okay so we have + + + align:start position:0% +okay so we have +um + + align:start position:0% +um + + + align:start position:0% +um +discussed that black hole can be + + align:start position:0% +discussed that black hole can be + + + align:start position:0% +discussed that black hole can be +considered as a sumal + + align:start position:0% +considered as a sumal + + + align:start position:0% +considered as a sumal +object and that actually black hoes + + align:start position:0% +object and that actually black hoes + + + align:start position:0% +object and that actually black hoes +oreas the the standard law of + + align:start position:0% + + + + align:start position:0% + +thermodynamics and + + align:start position:0% +thermodynamics and + + + align:start position:0% +thermodynamics and +now we also mention that the + + align:start position:0% +now we also mention that the + + + align:start position:0% +now we also mention that the +um it's a Lal question to ask whether + + align:start position:0% +um it's a Lal question to ask whether + + + align:start position:0% +um it's a Lal question to ask whether +black + + align:start position:0% +black + + + align:start position:0% +black +ho should be considered as ordinary qu + + align:start position:0% +ho should be considered as ordinary qu + + + align:start position:0% +ho should be considered as ordinary qu +mechanical + + align:start position:0% +mechanical + + + align:start position:0% +mechanical +object and so this is related to the + + align:start position:0% +object and so this is related to the + + + align:start position:0% +object and so this is related to the +issue of information + + align:start position:0% +issue of information + + + align:start position:0% +issue of information +Paradox so but if when disregard this + + align:start position:0% +Paradox so but if when disregard this + + + align:start position:0% +Paradox so but if when disregard this +information Paradox uh which I think now + + align:start position:0% +information Paradox uh which I think now + + + align:start position:0% +information Paradox uh which I think now +have a very good + + align:start position:0% +have a very good + + + align:start position:0% +have a very good +um in principle have a a rasonable + + align:start position:0% +um in principle have a a rasonable + + + align:start position:0% +um in principle have a a rasonable +resolution which we talk about + + align:start position:0% +resolution which we talk about + + + align:start position:0% +resolution which we talk about +later but if we do treat the black ho as + + align:start position:0% +later but if we do treat the black ho as + + + align:start position:0% +later but if we do treat the black ho as +ordinary Quantum mechanic mechanical + + align:start position:0% +ordinary Quantum mechanic mechanical + + + align:start position:0% +ordinary Quantum mechanic mechanical +object then then they actually um very + + align:start position:0% +object then then they actually um very + + + align:start position:0% +object then then they actually um very +important + + align:start position:0% + + + + align:start position:0% + +implications so one imp one implications + + align:start position:0% +implications so one imp one implications + + + align:start position:0% +implications so one imp one implications +this called the holographic + + align:start position:0% + + + + align:start position:0% + +principle so holographic principle by + + align:start position:0% +principle so holographic principle by + + + align:start position:0% +principle so holographic principle by +itself + + align:start position:0% +itself + + + align:start position:0% +itself +of is in some in some sense a rather + + align:start position:0% +of is in some in some sense a rather + + + align:start position:0% +of is in some in some sense a rather +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +um theistic concept at the + + align:start position:0% +um theistic concept at the + + + align:start position:0% +um theistic concept at the +moment and and I will also not to make + + align:start position:0% +moment and and I will also not to make + + + align:start position:0% +moment and and I will also not to make +it + + align:start position:0% +it + + + align:start position:0% +it +uh and I will also only give you a very + + align:start position:0% +uh and I will also only give you a very + + + align:start position:0% +uh and I will also only give you a very +humanistic discussion and it's possible + + align:start position:0% +humanistic discussion and it's possible + + + align:start position:0% +humanistic discussion and it's possible +to make it a little bit more rigorous + + align:start position:0% +to make it a little bit more rigorous + + + align:start position:0% +to make it a little bit more rigorous +but I will uh do it at the other um + + align:start position:0% +but I will uh do it at the other um + + + align:start position:0% +but I will uh do it at the other um +heuristic level just to give you a + + align:start position:0% +heuristic level just to give you a + + + align:start position:0% +heuristic level just to give you a +Feeling + + align:start position:0% +Feeling + + + align:start position:0% +Feeling +that there's something profound going + + align:start position:0% +that there's something profound going + + + align:start position:0% +that there's something profound going +on uh in quantum gravity because of the + + align:start position:0% +on uh in quantum gravity because of the + + + align:start position:0% +on uh in quantum gravity because of the +black holes because of black + + align:start position:0% +black holes because of black + + + align:start position:0% +black holes because of black +holes + + align:start position:0% +holes + + + align:start position:0% +holes +um so let's + + align:start position:0% + + + + align:start position:0% + +consider isolated + + align:start position:0% + + + + align:start position:0% + +system + + align:start position:0% +system + + + align:start position:0% +system +of + + align:start position:0% +of + + + align:start position:0% +of +mass say + + align:start position:0% + + + + align:start position:0% + +e and say + + align:start position:0% + + + + align:start position:0% + +entropy S + + align:start position:0% +entropy S + + + align:start position:0% +entropy S +zero say in a sympotic flat space + + align:start position:0% + + + + align:start position:0% + +time + + align:start position:0% + + + + align:start position:0% + +okay and then me also + + align:start position:0% + + + + align:start position:0% + +denote a as the + + align:start position:0% +denote a as the + + + align:start position:0% +denote a as the +area of the + + align:start position:0% + + + + align:start position:0% + +smallest + + align:start position:0% + + + + align:start position:0% + +sphere + + align:start position:0% + + + + align:start position:0% + +that say en closes the system + + align:start position:0% + + + + align:start position:0% + +okay and then and also let let me + + align:start position:0% +okay and then and also let let me + + + align:start position:0% +okay and then and also let let me +introduce let + + align:start position:0% +introduce let + + + align:start position:0% +introduce let +ma be + + align:start position:0% + + + + align:start position:0% + +the mass of the black + + align:start position:0% + + + + align:start position:0% + +hole of the same Horizon + + align:start position:0% +hole of the same Horizon + + + align:start position:0% +hole of the same Horizon +area + + align:start position:0% +area + + + align:start position:0% +area +yeah say + + align:start position:0% +yeah say + + + align:start position:0% +yeah say +with black + + align:start position:0% +with black + + + align:start position:0% +with black +ho + + align:start position:0% +ho + + + align:start position:0% +ho +with Horizon + + align:start position:0% + + + + align:start position:0% + +area a + + align:start position:0% + + + + align:start position:0% + +okay so in + + align:start position:0% + + + + align:start position:0% + +gr anything which is sufficiently + + align:start position:0% +gr anything which is sufficiently + + + align:start position:0% +gr anything which is sufficiently +massive will eventually collapse form a + + align:start position:0% +massive will eventually collapse form a + + + align:start position:0% +massive will eventually collapse form a +black + + align:start position:0% +black + + + align:start position:0% +black +hole because of + + align:start position:0% +hole because of + + + align:start position:0% +hole because of +that so we might must + + align:start position:0% + + + + align:start position:0% + +have e is smaller than + + align:start position:0% +have e is smaller than + + + align:start position:0% +have e is smaller than +ma + + align:start position:0% +ma + + + align:start position:0% +ma +okay so we must have e so whatever + + align:start position:0% +okay so we must have e so whatever + + + align:start position:0% +okay so we must have e so whatever +energe you can put in this region + + align:start position:0% +energe you can put in this region + + + align:start position:0% +energe you can put in this region +surrounded by area + + align:start position:0% + + + + align:start position:0% + +a must be smaller than the mass of a + + align:start position:0% +a must be smaller than the mass of a + + + align:start position:0% +a must be smaller than the mass of a +black hole which you can put in that + + align:start position:0% +black hole which you can put in that + + + align:start position:0% +black hole which you can put in that +region + + align:start position:0% + + + + align:start position:0% + +okay because otherwise if we have a more + + align:start position:0% +okay because otherwise if we have a more + + + align:start position:0% +okay because otherwise if we have a more +mass will already be a black + + align:start position:0% + + + + align:start position:0% + +hole Yeah say + + align:start position:0% + + + + align:start position:0% + +equal so now let's suppose e is smaller + + align:start position:0% +equal so now let's suppose e is smaller + + + align:start position:0% +equal so now let's suppose e is smaller +than + + align:start position:0% + + + + align:start position:0% + +Ma so we can + + align:start position:0% + + + + align:start position:0% + +now + + align:start position:0% + + + + align:start position:0% + +so suppose e is smaller than ma now we + + align:start position:0% +so suppose e is smaller than ma now we + + + align:start position:0% +so suppose e is smaller than ma now we +can + + align:start position:0% +can + + + align:start position:0% +can +add this amount of + + align:start position:0% +add this amount of + + + align:start position:0% +add this amount of +energy say ma minus + + align:start position:0% +energy say ma minus + + + align:start position:0% +energy say ma minus +E amount of + + align:start position:0% + + + + align:start position:0% + +energy to the + + align:start position:0% + + + + align:start position:0% + +system + + align:start position:0% +system + + + align:start position:0% +system +okay suppose we can do that keep a fixed + + align:start position:0% + + + + align:start position:0% + +okay so we can do that keep it + + align:start position:0% +okay so we can do that keep it + + + align:start position:0% +okay so we can do that keep it +fixed and then then this will reach a + + align:start position:0% +fixed and then then this will reach a + + + align:start position:0% +fixed and then then this will reach a +black hole + + align:start position:0% + + + + align:start position:0% + +mass then the final system will have a + + align:start position:0% +mass then the final system will have a + + + align:start position:0% +mass then the final system will have a +then the final system will be um we have + + align:start position:0% +then the final system will be um we have + + + align:start position:0% +then the final system will be um we have +the a black hole we have the black hole + + align:start position:0% +the a black hole we have the black hole + + + align:start position:0% +the a black hole we have the black hole +we have the energ given by + + align:start position:0% + + + + align:start position:0% + +Ma and that object must be a black hole + + align:start position:0% +Ma and that object must be a black hole + + + align:start position:0% +Ma and that object must be a black hole +because the uh + + align:start position:0% +because the uh + + + align:start position:0% +because the uh +um because the um yeah yeah because + + align:start position:0% +um because the um yeah yeah because + + + align:start position:0% +um because the um yeah yeah because +that's the black hole with the same + + align:start position:0% +that's the black hole with the same + + + align:start position:0% +that's the black hole with the same +Horizon area + + align:start position:0% + + + + align:start position:0% + +Okay + + align:start position:0% +Okay + + + align:start position:0% +Okay +U so so + + align:start position:0% +U so so + + + align:start position:0% +U so so +that's because of this process also + + align:start position:0% +that's because of this process also + + + align:start position:0% +that's because of this process also +tells you that the blacko + + align:start position:0% +tells you that the blacko + + + align:start position:0% +tells you that the blacko +entropy much greater than the s0 the + + align:start position:0% +entropy much greater than the s0 the + + + align:start position:0% +entropy much greater than the s0 the +initial entropy of this system plus the + + align:start position:0% +initial entropy of this system plus the + + + align:start position:0% +initial entropy of this system plus the +S + + align:start position:0% +S + + + align:start position:0% +S +Prime uh uh S Prime is the entropy of + + align:start position:0% +Prime uh uh S Prime is the entropy of + + + align:start position:0% +Prime uh uh S Prime is the entropy of +added + + align:start position:0% + + + + align:start position:0% + +energy okay so just because of the + + align:start position:0% +energy okay so just because of the + + + align:start position:0% +energy okay so just because of the +second L of thermodynamics your entropy + + align:start position:0% +second L of thermodynamics your entropy + + + align:start position:0% +second L of thermodynamics your entropy +should not + + align:start position:0% +should not + + + align:start position:0% +should not +decrease so so the + + align:start position:0% +decrease so so the + + + align:start position:0% +decrease so so the +final so you keep so you add this amount + + align:start position:0% +final so you keep so you add this amount + + + align:start position:0% +final so you keep so you add this amount +of energy so that this to to Ma so then + + align:start position:0% +of energy so that this to to Ma so then + + + align:start position:0% +of energy so that this to to Ma so then +you will precisely form a black hole of + + align:start position:0% +you will precisely form a black hole of + + + align:start position:0% +you will precisely form a black hole of +the mass Ma and with the Horizon area a + + align:start position:0% +the mass Ma and with the Horizon area a + + + align:start position:0% +the mass Ma and with the Horizon area a +and uh but this P entropy should be + + align:start position:0% +and uh but this P entropy should be + + + align:start position:0% +and uh but this P entropy should be +greater than s z plus the uh the entropy + + align:start position:0% +greater than s z plus the uh the entropy + + + align:start position:0% +greater than s z plus the uh the entropy +you added this is from the second L of + + align:start position:0% +you added this is from the second L of + + + align:start position:0% +you added this is from the second L of +some dyamics + + align:start position:0% +some dyamics + + + align:start position:0% +some dyamics +okay so then that + + align:start position:0% +okay so then that + + + align:start position:0% +okay so then that +means your initial en your initial + + align:start position:0% +means your initial en your initial + + + align:start position:0% +means your initial en your initial +entropy must be smaller than + + align:start position:0% +entropy must be smaller than + + + align:start position:0% +entropy must be smaller than +the black entropy + + align:start position:0% +the black entropy + + + align:start position:0% +the black entropy +okay must be smaller than a divided by 4 + + align:start position:0% +okay must be smaller than a divided by 4 + + + align:start position:0% +okay must be smaller than a divided by 4 +H bar G + + align:start position:0% +H bar G + + + align:start position:0% +H bar G +Newton + + align:start position:0% +Newton + + + align:start position:0% +Newton +okay so this argument tells + + align:start position:0% +okay so this argument tells + + + align:start position:0% +okay so this argument tells +you that the maximal + + align:start position:0% + + + + align:start position:0% + +entropy + + align:start position:0% +entropy + + + align:start position:0% +entropy +inside a + + align:start position:0% + + + + align:start position:0% + +region bounded by area + + align:start position:0% + + + + align:start position:0% + +a is given + + align:start position:0% + + + + align:start position:0% + +by okay + + align:start position:0% + + + + align:start position:0% + +yes so so we keeping a fixed at extra + + align:start position:0% +yes so so we keeping a fixed at extra + + + align:start position:0% +yes so so we keeping a fixed at extra +INRI to the system yeah uh so in that + + align:start position:0% +INRI to the system yeah uh so in that + + + align:start position:0% +INRI to the system yeah uh so in that +case uh why we don't have such a term + + align:start position:0% +case uh why we don't have such a term + + + align:start position:0% +case uh why we don't have such a term +sorry so so you said but we want to keep + + align:start position:0% +sorry so so you said but we want to keep + + + align:start position:0% +sorry so so you said but we want to keep +a fixed will that add actra entropy to + + align:start position:0% +a fixed will that add actra entropy to + + + align:start position:0% +a fixed will that add actra entropy to +the system yes uh so so according to the + + align:start position:0% +the system yes uh so so according to the + + + align:start position:0% +the system yes uh so so according to the +second La + + align:start position:0% +second La + + + align:start position:0% +second La +ofam + + align:start position:0% +ofam + + + align:start position:0% +ofam +why we we claim that the andri black ho + + align:start position:0% +why we we claim that the andri black ho + + + align:start position:0% +why we we claim that the andri black ho +is greater than or equal than S not plus + + align:start position:0% +is greater than or equal than S not plus + + + align:start position:0% +is greater than or equal than S not plus +s yeah uh uh okay add yeah because yeah + + align:start position:0% +s yeah uh uh okay add yeah because yeah + + + align:start position:0% +s yeah uh uh okay add yeah because yeah +this is the energy of added energ how + + align:start position:0% +this is the energy of added energ how + + + align:start position:0% +this is the energy of added energ how +about the actual energy that might be + + align:start position:0% +about the actual energy that might be + + + align:start position:0% +about the actual energy that might be +introduced by keeping a fixed like + + align:start position:0% +introduced by keeping a fixed like + + + align:start position:0% +introduced by keeping a fixed like +because it's not yeah whatever it is uh + + align:start position:0% +because it's not yeah whatever it is uh + + + align:start position:0% +because it's not yeah whatever it is uh +whatever it is suppose you can keep a + + align:start position:0% +whatever it is suppose you can keep a + + + align:start position:0% +whatever it is suppose you can keep a +fixed uh suppose you can keep a fixed + + align:start position:0% +fixed uh suppose you can keep a fixed + + + align:start position:0% +fixed uh suppose you can keep a fixed +then whatever uh uh things you added to + + align:start position:0% +then whatever uh uh things you added to + + + align:start position:0% +then whatever uh uh things you added to +that that total + + align:start position:0% +that that total + + + align:start position:0% +that that total +entropy must be smaller than the black + + align:start position:0% +entropy must be smaller than the black + + + align:start position:0% +entropy must be smaller than the black +entropy because black is the fow State + + align:start position:0% +entropy because black is the fow State + + + align:start position:0% +entropy because black is the fow State +you said uh it's an isolated system so + + align:start position:0% +you said uh it's an isolated system so + + + align:start position:0% +you said uh it's an isolated system so +with that uh how can you make sure that + + align:start position:0% +with that uh how can you make sure that + + + align:start position:0% +with that uh how can you make sure that +a is fixed why is yeah I'm just saying + + align:start position:0% +a is fixed why is yeah I'm just saying + + + align:start position:0% +a is fixed why is yeah I'm just saying +uh we are doing a thought experiment + + align:start position:0% +uh we are doing a thought experiment + + + align:start position:0% +uh we are doing a thought experiment +imagine you can do this by keeping a + + align:start position:0% +imagine you can do this by keeping a + + + align:start position:0% +imagine you can do this by keeping a +fixed yeah just say uh you you just put + + align:start position:0% +fixed yeah just say uh you you just put + + + align:start position:0% +fixed yeah just say uh you you just put +stuff in uh uh into this region uh so + + align:start position:0% +stuff in uh uh into this region uh so + + + align:start position:0% +stuff in uh uh into this region uh so +that stuff does not uh uh does not come + + align:start position:0% +that stuff does not uh uh does not come + + + align:start position:0% +that stuff does not uh uh does not come +out yeah just we have some region + + align:start position:0% +out yeah just we have some region + + + align:start position:0% +out yeah just we have some region +a uh maybe let me do it here you have + + align:start position:0% +a uh maybe let me do it here you have + + + align:start position:0% +a uh maybe let me do it here you have +some region + + align:start position:0% + + + + align:start position:0% + +a and there's some Mass inside here some + + align:start position:0% +a and there's some Mass inside here some + + + align:start position:0% +a and there's some Mass inside here some +energ stuff inside here so this is the + + align:start position:0% +energ stuff inside here so this is the + + + align:start position:0% +energ stuff inside here so this is the +region a and then you just keep putting + + align:start position:0% +region a and then you just keep putting + + + align:start position:0% +region a and then you just keep putting +stuff + + align:start position:0% +stuff + + + align:start position:0% +stuff +in just keeping keep putting stuff in so + + align:start position:0% +in just keeping keep putting stuff in so + + + align:start position:0% +in just keeping keep putting stuff in so +that those things don't come out of a + + align:start position:0% +that those things don't come out of a + + + align:start position:0% +that those things don't come out of a +don't come out of this region uh uh that + + align:start position:0% +don't come out of this region uh uh that + + + align:start position:0% +don't come out of this region uh uh that +what this + + align:start position:0% +what this + + + align:start position:0% +what this +means then a is not smallest sphere then + + align:start position:0% +means then a is not smallest sphere then + + + align:start position:0% +means then a is not smallest sphere then +a is not smallest sphere to a is what + + align:start position:0% +a is not smallest sphere to a is what + + + align:start position:0% +a is not smallest sphere to a is what +not the smallest sphere that includ the + + align:start position:0% +not the smallest sphere that includ the + + + align:start position:0% +not the smallest sphere that includ the +system so that's it's not no no a is not + + align:start position:0% +system so that's it's not no no a is not + + + align:start position:0% +system so that's it's not no no a is not +the smallest to be increase system a + + align:start position:0% +the smallest to be increase system a + + + align:start position:0% +the smallest to be increase system a +just yeah maybe I should call it this A + + align:start position:0% +just yeah maybe I should call it this A + + + align:start position:0% +just yeah maybe I should call it this A +this + + align:start position:0% +this + + + align:start position:0% +this +area of a sphere + + align:start position:0% + + + + align:start position:0% + +yeah sorry uh uh uh yeah uh thanks so so + + align:start position:0% +yeah sorry uh uh uh yeah uh thanks so so + + + align:start position:0% +yeah sorry uh uh uh yeah uh thanks so so +so just enough a to be a to be a sphere + + align:start position:0% +so just enough a to be a to be a sphere + + + align:start position:0% +so just enough a to be a to be a sphere +that enclose the system yeah yeah sorry + + align:start position:0% +that enclose the system yeah yeah sorry + + + align:start position:0% +that enclose the system yeah yeah sorry +I should not put the smallest there for + + align:start position:0% +I should not put the smallest there for + + + align:start position:0% +I should not put the smallest there for +some reason um for some reason uh yeah + + align:start position:0% +some reason um for some reason uh yeah + + + align:start position:0% +some reason um for some reason uh yeah +no no no no a yeah should not be + + align:start position:0% +no no no no a yeah should not be + + + align:start position:0% +no no no no a yeah should not be +smallest just a is any sphere uh uh yeah + + align:start position:0% +smallest just a is any sphere uh uh yeah + + + align:start position:0% +smallest just a is any sphere uh uh yeah +just some sphere which encos the + + align:start position:0% +just some sphere which encos the + + + align:start position:0% +just some sphere which encos the +region okay yes so it seems that this + + align:start position:0% +region okay yes so it seems that this + + + align:start position:0% +region okay yes so it seems that this +argument implicitly assumes that in + + align:start position:0% +argument implicitly assumes that in + + + align:start position:0% +argument implicitly assumes that in +order to add entropy that sort of + + align:start position:0% +order to add entropy that sort of + + + align:start position:0% +order to add entropy that sort of +corresponds to adding some amount of + + align:start position:0% +corresponds to adding some amount of + + + align:start position:0% +corresponds to adding some amount of +energy but is it possible to add entropy + + align:start position:0% +energy but is it possible to add entropy + + + align:start position:0% +energy but is it possible to add entropy +to the system without adding energy to + + align:start position:0% +to the system without adding energy to + + + align:start position:0% +to the system without adding energy to +the system oh you can you can that just + + align:start position:0% +the system oh you can you can that just + + + align:start position:0% +the system oh you can you can that just +make it even more whatever it is this is + + align:start position:0% +make it even more whatever it is this is + + + align:start position:0% +make it even more whatever it is this is +a final + + align:start position:0% +a final + + + align:start position:0% +a final +state so so the based Assumption of this + + align:start position:0% +state so so the based Assumption of this + + + align:start position:0% +state so so the based Assumption of this +is that if if you can put stuff inside + + align:start position:0% +is that if if you can put stuff inside + + + align:start position:0% +is that if if you can put stuff inside +this + + align:start position:0% +this + + + align:start position:0% +this +region uh or whatever is + + align:start position:0% +region uh or whatever is + + + align:start position:0% +region uh or whatever is +inside uh + + align:start position:0% +inside uh + + + align:start position:0% +inside uh +yeah the Su says the maximum stuff you + + align:start position:0% +yeah the Su says the maximum stuff you + + + align:start position:0% +yeah the Su says the maximum stuff you +can put inside the region is a black ho + + align:start position:0% +can put inside the region is a black ho + + + align:start position:0% +can put inside the region is a black ho +with the Horizon + + align:start position:0% +with the Horizon + + + align:start position:0% +with the Horizon +area well I guess what I'm confused + + align:start position:0% +area well I guess what I'm confused + + + align:start position:0% +area well I guess what I'm confused +about is that it seems that I certainly + + align:start position:0% +about is that it seems that I certainly + + + align:start position:0% +about is that it seems that I certainly +believe when you say that you you can't + + align:start position:0% +believe when you say that you you can't + + + align:start position:0% +believe when you say that you you can't +have a certain amount of energy in an + + align:start position:0% +have a certain amount of energy in an + + + align:start position:0% +have a certain amount of energy in an +area but I'm not sure why you can't have + + align:start position:0% +area but I'm not sure why you can't have + + + align:start position:0% +area but I'm not sure why you can't have +a certain amount of entropy in an area + + align:start position:0% +a certain amount of entropy in an area + + + align:start position:0% +a certain amount of entropy in an area +if energy and entropy are not oh no no + + align:start position:0% +if energy and entropy are not oh no no + + + align:start position:0% +if energy and entropy are not oh no no +we I'm not making that assumption the + + align:start position:0% +we I'm not making that assumption the + + + align:start position:0% +we I'm not making that assumption the +entropy the entropy is just a + + align:start position:0% +entropy the entropy is just a + + + align:start position:0% +entropy the entropy is just a +consequence of that this is a final + + align:start position:0% +consequence of that this is a final + + + align:start position:0% +consequence of that this is a final +State entropy the the final State + + align:start position:0% +State entropy the the final State + + + align:start position:0% +State entropy the the final State +entropy is always + + align:start position:0% +entropy is always + + + align:start position:0% +entropy is always +ner than the than entropy of your + + align:start position:0% +ner than the than entropy of your + + + align:start position:0% +ner than the than entropy of your +initial State okay yeah yeah entropy is + + align:start position:0% +initial State okay yeah yeah entropy is + + + align:start position:0% +initial State okay yeah yeah entropy is +a derived this equation is not + + align:start position:0% +a derived this equation is not + + + align:start position:0% +a derived this equation is not +assumption is derived okay yeah the + + align:start position:0% +assumption is derived okay yeah the + + + align:start position:0% +assumption is derived okay yeah the +assumption is that the the black hole is + + align:start position:0% +assumption is that the the black hole is + + + align:start position:0% +assumption is that the the black hole is +the maximal uh is the most massive + + align:start position:0% +the maximal uh is the most massive + + + align:start position:0% +the maximal uh is the most massive +object you can put inside this + + align:start position:0% +object you can put inside this + + + align:start position:0% +object you can put inside this +region sure + + align:start position:0% +region sure + + + align:start position:0% +region sure +yeah but but you can't have a less + + align:start position:0% +yeah but but you can't have a less + + + align:start position:0% +yeah but but you can't have a less +massive object with more than that + + align:start position:0% +massive object with more than that + + + align:start position:0% +massive object with more than that +entropy + + align:start position:0% +entropy + + + align:start position:0% +entropy +you can't have a less massive object + + align:start position:0% +you can't have a less massive object + + + align:start position:0% +you can't have a less massive object +with entropy that is more than that + + align:start position:0% +with entropy that is more than that + + + align:start position:0% +with entropy that is more than that +value inside the same region uh uh this + + align:start position:0% +value inside the same region uh uh this + + + align:start position:0% +value inside the same region uh uh this +is ruled out by this uh + + align:start position:0% +is ruled out by this uh + + + align:start position:0% +is ruled out by this uh +uh once you get this equation then you + + align:start position:0% +uh once you get this equation then you + + + align:start position:0% +uh once you get this equation then you +don't ask about the + + align:start position:0% +don't ask about the + + + align:start position:0% +don't ask about the +mass uh it just n eny must be smaller + + align:start position:0% +mass uh it just n eny must be smaller + + + align:start position:0% +mass uh it just n eny must be smaller +than this + + align:start position:0% + + + + align:start position:0% + +value any other questions yes how do we + + align:start position:0% +value any other questions yes how do we + + + align:start position:0% +value any other questions yes how do we +keep track of of the area I mean doesn't + + align:start position:0% +keep track of of the area I mean doesn't + + + align:start position:0% +keep track of of the area I mean doesn't +space + + align:start position:0% + + + + align:start position:0% + +right so that's why I say this is a + + align:start position:0% +right so that's why I say this is a + + + align:start position:0% +right so that's why I say this is a +little + + align:start position:0% +little + + + align:start position:0% +little +bit heuristic argument and that's why I + + align:start position:0% +bit heuristic argument and that's why I + + + align:start position:0% +bit heuristic argument and that's why I +say this is holistic argument yeah yeah + + align:start position:0% +say this is holistic argument yeah yeah + + + align:start position:0% +say this is holistic argument yeah yeah +indeed you have to be a little bit more + + align:start position:0% +indeed you have to be a little bit more + + + align:start position:0% +indeed you have to be a little bit more +careful about that uh + + align:start position:0% +careful about that uh + + + align:start position:0% +careful about that uh +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +um yeah but uh + + align:start position:0% +um yeah but uh + + + align:start position:0% +um yeah but uh +um say if you + + align:start position:0% +um say if you + + + align:start position:0% +um say if you +um if you uh + + align:start position:0% +um if you uh + + + align:start position:0% +um if you uh +um the keying is about the area and this + + align:start position:0% +um the keying is about the area and this + + + align:start position:0% +um the keying is about the area and this +order one Cent one maybe have to think + + align:start position:0% +order one Cent one maybe have to think + + + align:start position:0% +order one Cent one maybe have to think +about it uh we include the quantum + + align:start position:0% +about it uh we include the quantum + + + align:start position:0% +about it uh we include the quantum +Corrections Etc the back reaction Etc + + align:start position:0% +Corrections Etc the back reaction Etc + + + align:start position:0% +Corrections Etc the back reaction Etc +yeah but the keying is the area the + + align:start position:0% +yeah but the keying is the area the + + + align:start position:0% +yeah but the keying is the area the +black ho must be proportional to the + + align:start position:0% +black ho must be proportional to the + + + align:start position:0% +black ho must be proportional to the +area well uh it's St on assumption that + + align:start position:0% +area well uh it's St on assumption that + + + align:start position:0% +area well uh it's St on assumption that +the arrow of the arrow of the Horizon + + align:start position:0% +the arrow of the arrow of the Horizon + + + align:start position:0% +the arrow of the arrow of the Horizon +gra is is only based on the + + align:start position:0% +gra is is only based on the + + + align:start position:0% +gra is is only based on the +mass oh yeah yeah yeah yeah so the let + + align:start position:0% +mass oh yeah yeah yeah yeah so the let + + + align:start position:0% +mass oh yeah yeah yeah yeah so the let +me again there's a two nature of this + + align:start position:0% +me again there's a two nature of this + + + align:start position:0% +me again there's a two nature of this +argument the first nature of the + + align:start position:0% +argument the first nature of the + + + align:start position:0% +argument the first nature of the +argument is the the the maximal energe + + align:start position:0% +argument is the the the maximal energe + + + align:start position:0% +argument is the the the maximal energe +you can put inside the region is a black + + align:start position:0% +you can put inside the region is a black + + + align:start position:0% +you can put inside the region is a black +hole who whose Horizon area is given by + + align:start position:0% +hole who whose Horizon area is given by + + + align:start position:0% +hole who whose Horizon area is given by +the area of this region this is + + align:start position:0% +the area of this region this is + + + align:start position:0% +the area of this region this is +assumption yeah this is assumption yeah + + align:start position:0% +assumption yeah this is assumption yeah + + + align:start position:0% +assumption yeah this is assumption yeah +because we know in the gr any + + align:start position:0% +because we know in the gr any + + + align:start position:0% +because we know in the gr any +sufficiently massive thing will collapse + + align:start position:0% +sufficiently massive thing will collapse + + + align:start position:0% +sufficiently massive thing will collapse +to form black hole yeah and if you have + + align:start position:0% +to form black hole yeah and if you have + + + align:start position:0% +to form black hole yeah and if you have +more mass then the Horizon area will be + + align:start position:0% +more mass then the Horizon area will be + + + align:start position:0% +more mass then the Horizon area will be +outside and then you will be outside + + align:start position:0% +outside and then you will be outside + + + align:start position:0% +outside and then you will be outside +this area you you can no longer keep + + align:start position:0% +this area you you can no longer keep + + + align:start position:0% +this area you you can no longer keep +this a fixed yeah so that's the first + + align:start position:0% +this a fixed yeah so that's the first + + + align:start position:0% +this a fixed yeah so that's the first +assumption so with that + + align:start position:0% +assumption so with that + + + align:start position:0% +assumption so with that +assumption uh then with that assumption + + align:start position:0% +assumption uh then with that assumption + + + align:start position:0% +assumption uh then with that assumption +then just follows from the second no of + + align:start position:0% +then just follows from the second no of + + + align:start position:0% +then just follows from the second no of +Dynamics because this is whatever uh uh + + align:start position:0% +Dynamics because this is whatever uh uh + + + align:start position:0% +Dynamics because this is whatever uh uh +the entropy of the matter inside then + + align:start position:0% +the entropy of the matter inside then + + + align:start position:0% +the entropy of the matter inside then +this is whatever the initial entropy you + + align:start position:0% +this is whatever the initial entropy you + + + align:start position:0% +this is whatever the initial entropy you +do of the energy you need put it in to + + align:start position:0% +do of the energy you need put it in to + + + align:start position:0% +do of the energy you need put it in to +make it into a black hole and then that + + align:start position:0% +make it into a black hole and then that + + + align:start position:0% +make it into a black hole and then that +must be smaller than the entropy of the + + align:start position:0% +must be smaller than the entropy of the + + + align:start position:0% +must be smaller than the entropy of the +final state which is the entropy of the + + align:start position:0% +final state which is the entropy of the + + + align:start position:0% +final state which is the entropy of the +black hole + + align:start position:0% +black hole + + + align:start position:0% +black hole +but my question is that by keeping a + + align:start position:0% +but my question is that by keeping a + + + align:start position:0% +but my question is that by keeping a +fixed you might introduce actual entropy + + align:start position:0% +fixed you might introduce actual entropy + + + align:start position:0% +fixed you might introduce actual entropy +into the system H yeah it doesn't matter + + align:start position:0% +into the system H yeah it doesn't matter + + + align:start position:0% +into the system H yeah it doesn't matter +as far as the uh uh black ho is a final + + align:start position:0% +as far as the uh uh black ho is a final + + + align:start position:0% +as far as the uh uh black ho is a final +entropy State uh what you are saying is + + align:start position:0% +entropy State uh what you are saying is + + + align:start position:0% +entropy State uh what you are saying is +that there might be some other things + + align:start position:0% +that there might be some other things + + + align:start position:0% +that there might be some other things +here it's fine that does not change the + + align:start position:0% +here it's fine that does not change the + + + align:start position:0% +here it's fine that does not change the +the the direction of this um might be + + align:start position:0% +the the direction of this um might be + + + align:start position:0% +the the direction of this um might be +negative uh I'm not sure + + align:start position:0% +negative uh I'm not sure + + + align:start position:0% +negative uh I'm not sure +just no no whatever it is uh whatever it + + align:start position:0% +just no no whatever it is uh whatever it + + + align:start position:0% +just no no whatever it is uh whatever it +is this is my initial so that's why this + + align:start position:0% +is this is my initial so that's why this + + + align:start position:0% +is this is my initial so that's why this +is inequality here this is not equality + + align:start position:0% +is inequality here this is not equality + + + align:start position:0% +is inequality here this is not equality +inequality and and uh we are just using + + align:start position:0% +inequality and and uh we are just using + + + align:start position:0% +inequality and and uh we are just using +the second L of thermodynamics this is + + align:start position:0% +the second L of thermodynamics this is + + + align:start position:0% +the second L of thermodynamics this is +your initial State entropy this is my + + align:start position:0% +your initial State entropy this is my + + + align:start position:0% +your initial State entropy this is my +final State entropy this must be greater + + align:start position:0% +final State entropy this must be greater + + + align:start position:0% +final State entropy this must be greater +than that we're not asking the specific + + align:start position:0% +than that we're not asking the specific + + + align:start position:0% +than that we're not asking the specific +process we're not asking the specific + + align:start position:0% +process we're not asking the specific + + + align:start position:0% +process we're not asking the specific +process yeah just the final State have + + align:start position:0% +process yeah just the final State have + + + align:start position:0% +process yeah just the final State have +be greater than initial + + align:start position:0% + + + + align:start position:0% + +state + + align:start position:0% + + + + align:start position:0% + +good okay so now let's see what we + + align:start position:0% +good okay so now let's see what we + + + align:start position:0% +good okay so now let's see what we +can try to go a little bit further from + + align:start position:0% +can try to go a little bit further from + + + align:start position:0% +can try to go a little bit further from +here so now let's + + align:start position:0% + + + + align:start position:0% + +recall so now we really treat the black + + align:start position:0% +recall so now we really treat the black + + + align:start position:0% +recall so now we really treat the black +ho as a Quantum statistical object so + + align:start position:0% +ho as a Quantum statistical object so + + + align:start position:0% +ho as a Quantum statistical object so +now + + align:start position:0% +now + + + align:start position:0% +now +recall definition of + + align:start position:0% + + + + align:start position:0% + +entropy + + align:start position:0% + + + + align:start position:0% + +in Quantum statistical + + align:start position:0% + + + + align:start position:0% + +physics + + align:start position:0% + + + + align:start position:0% + +okay so if you say I have some + + align:start position:0% +okay so if you say I have some + + + align:start position:0% +okay so if you say I have some +system and the state of and the state of + + align:start position:0% +system and the state of and the state of + + + align:start position:0% +system and the state of and the state of +that system is described by some density + + align:start position:0% +that system is described by some density + + + align:start position:0% +that system is described by some density +operator or density Matrix and then then + + align:start position:0% +operator or density Matrix and then then + + + align:start position:0% +operator or density Matrix and then then +the entropy of that system is just given + + align:start position:0% +the entropy of that system is just given + + + align:start position:0% +the entropy of that system is just given +by this formula that's given by this + + align:start position:0% +by this formula that's given by this + + + align:start position:0% +by this formula that's given by this +formula okay in + + align:start position:0% + + + + align:start position:0% + +particular in + + align:start position:0% + + + + align:start position:0% + +particular for + + align:start position:0% + + + + align:start position:0% + +system with n + + align:start position:0% + + + + align:start position:0% + +dimensional c + + align:start position:0% + + + + align:start position:0% + +space + + align:start position:0% + + + + align:start position:0% + +okay so this is the n dimensional h + + align:start position:0% +okay so this is the n dimensional h + + + align:start position:0% +okay so this is the n dimensional h +space okay this is a a dimension of the + + align:start position:0% +space okay this is a a dimension of the + + + align:start position:0% +space okay this is a a dimension of the +h + + align:start position:0% +h + + + align:start position:0% +h +space that s + + align:start position:0% +space that s + + + align:start position:0% +space that s +Max is no n so the maximum possible + + align:start position:0% +Max is no n so the maximum possible + + + align:start position:0% +Max is no n so the maximum possible +entropy you can have is no + + align:start position:0% + + + + align:start position:0% + +n okay is this fact familiar to + + align:start position:0% +n okay is this fact familiar to + + + align:start position:0% +n okay is this fact familiar to +you so so you can convince yourself the + + align:start position:0% +you so so you can convince yourself the + + + align:start position:0% +you so so you can convince yourself the +maximal entropy is realized when row is + + align:start position:0% +maximal entropy is realized when row is + + + align:start position:0% +maximal entropy is realized when row is +just given by one over n times identity + + align:start position:0% +just given by one over n times identity + + + align:start position:0% +just given by one over n times identity +Matrix okay and so uh so this is the so + + align:start position:0% +Matrix okay and so uh so this is the so + + + align:start position:0% +Matrix okay and so uh so this is the so +this is the density Matrix which have + + align:start position:0% +this is the density Matrix which have + + + align:start position:0% +this is the density Matrix which have +low information because every state + + align:start position:0% +low information because every state + + + align:start position:0% +low information because every state +plays the same role and this state then + + align:start position:0% +plays the same role and this state then + + + align:start position:0% +plays the same role and this state then +you can plug in here and give you log n + + align:start position:0% +you can plug in here and give you log n + + + align:start position:0% +you can plug in here and give you log n +and the maximum m means you have minimal + + align:start position:0% +and the maximum m means you have minimal + + + align:start position:0% +and the maximum m means you have minimal +information okay and that is the state + + align:start position:0% +information okay and that is the state + + + align:start position:0% +information okay and that is the state +with minimal + + align:start position:0% +with minimal + + + align:start position:0% +with minimal +information and you can also just prove + + align:start position:0% +information and you can also just prove + + + align:start position:0% +information and you can also just prove +yourself youing using the um yeah using + + align:start position:0% +yourself youing using the um yeah using + + + align:start position:0% +yourself youing using the um yeah using +some algebra but this is a + + align:start position:0% +some algebra but this is a + + + align:start position:0% +some algebra but this is a +physic a physical argument for + + align:start position:0% + + + + align:start position:0% + +this so now if we compare with this two + + align:start position:0% +this so now if we compare with this two + + + align:start position:0% +this so now if we compare with this two +formula then we can draw a + + align:start position:0% +formula then we can draw a + + + align:start position:0% +formula then we can draw a +conclusion is + + align:start position:0% +conclusion is + + + align:start position:0% +conclusion is +that the so let me add a word called + + align:start position:0% +that the so let me add a word called + + + align:start position:0% +that the so let me add a word called +effective effective + + align:start position:0% + + + + align:start position:0% + +dimension of the h + + align:start position:0% + + + + align:start position:0% + +space for + + align:start position:0% + + + + align:start position:0% + +system inside the + + align:start position:0% + + + + align:start position:0% + +region + + align:start position:0% + + + + align:start position:0% + +of area + + align:start position:0% + + + + align:start position:0% + +a is bonded + + align:start position:0% + + + + align:start position:0% + +by log + + align:start position:0% +by log + + + align:start position:0% +by log +n must be smaller than a h bar + + align:start position:0% +n must be smaller than a h bar + + + align:start position:0% +n must be smaller than a h bar +GN + + align:start position:0% + + + + align:start position:0% + +okay so that tells you so what you can + + align:start position:0% +okay so that tells you so what you can + + + align:start position:0% +okay so that tells you so what you can +put inside this region of area a that's + + align:start position:0% +put inside this region of area a that's + + + align:start position:0% +put inside this region of area a that's +the maximum entropy you can + + align:start position:0% +the maximum entropy you can + + + align:start position:0% +the maximum entropy you can +have so and and if you have n deg + + align:start position:0% +have so and and if you have n deg + + + align:start position:0% +have so and and if you have n deg +Freedom then the maximum entropy you can + + align:start position:0% +Freedom then the maximum entropy you can + + + align:start position:0% +Freedom then the maximum entropy you can +have for this n deg is is log n then + + align:start position:0% +have for this n deg is is log n then + + + align:start position:0% +have for this n deg is is log n then +that tells you that log n must be + + align:start position:0% +that tells you that log n must be + + + align:start position:0% +that tells you that log n must be +smaller than this okay smaller or equal + + align:start position:0% +smaller than this okay smaller or equal + + + align:start position:0% +smaller than this okay smaller or equal +to + + align:start position:0% +to + + + align:start position:0% +to +that and so let me write this in terms + + align:start position:0% +that and so let me write this in terms + + + align:start position:0% +that and so let me write this in terms +of the so this can also for H bar and is + + align:start position:0% +of the so this can also for H bar and is + + + align:start position:0% +of the so this can also for H bar and is +also a plank n Square so it's also four + + align:start position:0% +also a plank n Square so it's also four + + + align:start position:0% +also a plank n Square so it's also four +times the pl lens + + align:start position:0% + + + + align:start position:0% + +Square sorry for this + + align:start position:0% +Square sorry for this + + + align:start position:0% +Square sorry for this +part P space it can be even infinite + + align:start position:0% +part P space it can be even infinite + + + align:start position:0% +part P space it can be even infinite +yeah let me see that that's why really + + align:start position:0% +yeah let me see that that's why really + + + align:start position:0% +yeah let me see that that's why really +defective so so now let me make some + + align:start position:0% +defective so so now let me make some + + + align:start position:0% +defective so so now let me make some +remarks now let me some make some + + align:start position:0% + + + + align:start position:0% + +remarks + + align:start position:0% +remarks + + + align:start position:0% +remarks +so zero + + align:start position:0% +so zero + + + align:start position:0% +so zero +remarks is that for + + align:start position:0% + + + + align:start position:0% + +system of n + + align:start position:0% +system of n + + + align:start position:0% +system of n +spins say n Spin half particle so when I + + align:start position:0% +spins say n Spin half particle so when I + + + align:start position:0% +spins say n Spin half particle so when I +say spins I always mean spin + + align:start position:0% +say spins I always mean spin + + + align:start position:0% +say spins I always mean spin +half then the dimension of the h space + + align:start position:0% +half then the dimension of the h space + + + align:start position:0% +half then the dimension of the h space +is 2 to the^ n + + align:start position:0% +is 2 to the^ n + + + align:start position:0% +is 2 to the^ n +okay just remind + + align:start position:0% + + + + align:start position:0% + +you but T but the dimension + + align:start position:0% + + + + align:start position:0% + +of + + align:start position:0% +of + + + align:start position:0% +of +H the h space so normally I use script H + + align:start position:0% +H the h space so normally I use script H + + + align:start position:0% +H the h space so normally I use script H +to to to Delo the h space for a single + + align:start position:0% +to to to Delo the h space for a single + + + align:start position:0% +to to to Delo the h space for a single +harmonic + + align:start position:0% + + + + align:start position:0% + +oscillator so the + + align:start position:0% +oscillator so the + + + align:start position:0% +oscillator so the +next so the simply system is spin then + + align:start position:0% +next so the simply system is spin then + + + align:start position:0% +next so the simply system is spin then +the next simply system is essentially + + align:start position:0% +the next simply system is essentially + + + align:start position:0% +the next simply system is essentially +harmonic + + align:start position:0% +harmonic + + + align:start position:0% +harmonic +oscillator and for for even for single + + align:start position:0% +oscillator and for for even for single + + + align:start position:0% +oscillator and for for even for single +harmonic + + align:start position:0% +harmonic + + + align:start position:0% +harmonic +oscillator and the dimension of H is + + align:start position:0% + + + + align:start position:0% + +infinite okay and then you ask what I'm + + align:start position:0% +infinite okay and then you ask what I'm + + + align:start position:0% +infinite okay and then you ask what I'm +talking about here because here I say + + align:start position:0% +talking about here because here I say + + + align:start position:0% +talking about here because here I say +the uh the h space should be smaller + + align:start position:0% +the uh the h space should be smaller + + + align:start position:0% +the uh the h space should be smaller +than + + align:start position:0% + + + + align:start position:0% + +that + + align:start position:0% +that + + + align:start position:0% +that +but okay so even though even for single + + align:start position:0% +but okay so even though even for single + + + align:start position:0% +but okay so even though even for single +harmonic oate the H is + + align:start position:0% +harmonic oate the H is + + + align:start position:0% +harmonic oate the H is +infinite but + + align:start position:0% +infinite but + + + align:start position:0% +infinite but +for but for a Quantum mechanic system + + align:start position:0% +for but for a Quantum mechanic system + + + align:start position:0% +for but for a Quantum mechanic system +for Quantum + + align:start position:0% + + + + align:start position:0% + +system with a finite number deg + + align:start position:0% + + + + align:start position:0% + +Freedom by fin number de freedom for + + align:start position:0% +Freedom by fin number de freedom for + + + align:start position:0% +Freedom by fin number de freedom for +example you can interpret as for example + + align:start position:0% +example you can interpret as for example + + + align:start position:0% +example you can interpret as for example +five number of harmonic oscillators + + align:start position:0% +five number of harmonic oscillators + + + align:start position:0% +five number of harmonic oscillators +okay the + + align:start position:0% + + + + align:start position:0% + +dimension of the h + + align:start position:0% + + + + align:start position:0% + +space + + align:start position:0% + + + + align:start position:0% + +below some + + align:start position:0% +below some + + + align:start position:0% +below some +finite energy + + align:start position:0% +finite energy + + + align:start position:0% +finite energy +scale + + align:start position:0% +scale + + + align:start position:0% +scale +energy is always + + align:start position:0% + + + + align:start position:0% + +finite okay it's always + + align:start position:0% +finite okay it's always + + + align:start position:0% +finite okay it's always +finite and uh so that's why I used the + + align:start position:0% +finite and uh so that's why I used the + + + align:start position:0% +finite and uh so that's why I used the +the word effective there and because + + align:start position:0% +the word effective there and because + + + align:start position:0% +the word effective there and because +because normally if you normally we all + + align:start position:0% +because normally if you normally we all + + + align:start position:0% +because normally if you normally we all +consider the fight energy yeah because + + align:start position:0% +consider the fight energy yeah because + + + align:start position:0% +consider the fight energy yeah because +the system all have fight energy and + + align:start position:0% +the system all have fight energy and + + + align:start position:0% +the system all have fight energy and +then you have effective you have a fight + + align:start position:0% +then you have effective you have a fight + + + align:start position:0% +then you have effective you have a fight +dimensional h space + + align:start position:0% +dimensional h space + + + align:start position:0% +dimensional h space +okay so so uh so this equation is not + + align:start position:0% +okay so so uh so this equation is not + + + align:start position:0% +okay so so uh so this equation is not +that + + align:start position:0% + + + + align:start position:0% + +crazy so and in + + align:start position:0% +crazy so and in + + + align:start position:0% +crazy so and in +typical so actually in typical physical + + align:start position:0% +typical so actually in typical physical + + + align:start position:0% +typical so actually in typical physical +systems even for harmonic oscillators + + align:start position:0% +systems even for harmonic oscillators + + + align:start position:0% +systems even for harmonic oscillators +both for spin or harmonic oscillators + + align:start position:0% + + + + align:start position:0% + +essentially number of degrees + + align:start position:0% + + + + align:start position:0% + +freedom + + align:start position:0% + + + + align:start position:0% + +is of all the log n yeah is the n is the + + align:start position:0% +is of all the log n yeah is the n is the + + + align:start position:0% +is of all the log n yeah is the n is the +effective dimension of your h space + + align:start position:0% +effective dimension of your h space + + + align:start position:0% +effective dimension of your h space +okay yeah this is obvious from the + + align:start position:0% +okay yeah this is obvious from the + + + align:start position:0% +okay yeah this is obvious from the +spin okay this is also of + + align:start position:0% +spin okay this is also of + + + align:start position:0% +spin okay this is also of +obvious if you have a harmonic + + align:start position:0% +obvious if you have a harmonic + + + align:start position:0% +obvious if you have a harmonic +oscillator so each harmonic oscillator + + align:start position:0% +oscillator so each harmonic oscillator + + + align:start position:0% +oscillator so each harmonic oscillator +is fitly + + align:start position:0% +is fitly + + + align:start position:0% +is fitly +excited and then again roughly the uh + + align:start position:0% +excited and then again roughly the uh + + + align:start position:0% +excited and then again roughly the uh +log n is the number of harmonic + + align:start position:0% +log n is the number of harmonic + + + align:start position:0% +log n is the number of harmonic +oscillators + + align:start position:0% +oscillators + + + align:start position:0% +oscillators +okay so so be because of this we can + + align:start position:0% +okay so so be because of this we can + + + align:start position:0% +okay so so be because of this we can +also write this equation + + align:start position:0% +also write this equation + + + align:start position:0% +also write this equation +as the L of degre + + align:start position:0% +as the L of degre + + + align:start position:0% +as the L of degre +Freedom over + + align:start position:0% +Freedom over + + + align:start position:0% +Freedom over +any quantum gravity + + align:start position:0% + + + + align:start position:0% + +system inside the region a can + + align:start position:0% + + + + align:start position:0% + +be should be smaller than should be + + align:start position:0% +be should be smaller than should be + + + align:start position:0% +be should be smaller than should be +bounded by the area of that region + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +so this + + align:start position:0% + + + + align:start position:0% + +bond is certainly + + align:start position:0% + + + + align:start position:0% + +valate in non-gravitational + + align:start position:0% + + + + align:start position:0% + +systems + + align:start position:0% + + + + align:start position:0% + +okay because in non gravitation systems + + align:start position:0% +okay because in non gravitation systems + + + align:start position:0% +okay because in non gravitation systems +whose number with + + align:start position:0% + + + + align:start position:0% + +freedom and + + align:start position:0% +freedom and + + + align:start position:0% +freedom and +S the log n the log of your dimensional + + align:start position:0% +S the log n the log of your dimensional + + + align:start position:0% +S the log n the log of your dimensional +your space is + + align:start position:0% + + + + align:start position:0% + +proportional to the + + align:start position:0% +proportional to the + + + align:start position:0% +proportional to the +volume + + align:start position:0% + + + + align:start position:0% + +rather than + + align:start position:0% + + + + align:start position:0% + +area so when the region is big + + align:start position:0% +area so when the region is big + + + align:start position:0% +area so when the region is big +enough then you're guaranteed to uh to + + align:start position:0% +enough then you're guaranteed to uh to + + + align:start position:0% +enough then you're guaranteed to uh to +violate this Bond because of course the + + align:start position:0% +violate this Bond because of course the + + + align:start position:0% +violate this Bond because of course the +volume grows faster than the area if you + + align:start position:0% +volume grows faster than the area if you + + + align:start position:0% +volume grows faster than the area if you +have a + + align:start position:0% +have a + + + align:start position:0% +have a +sufficiently larger region so so for + + align:start position:0% + + + + align:start position:0% + +example can just a lace of + + align:start position:0% + + + + align:start position:0% + +spins say three dimensional lace of + + align:start position:0% +spins say three dimensional lace of + + + align:start position:0% +spins say three dimensional lace of +spins of La spacing + + align:start position:0% + + + + align:start position:0% + +a say of latis spacing + + align:start position:0% +a say of latis spacing + + + align:start position:0% +a say of latis spacing +a + + align:start position:0% +a + + + align:start position:0% +a +okay then the total number of + + align:start position:0% + + + + align:start position:0% + +spins then the total number of + + align:start position:0% +spins then the total number of + + + align:start position:0% +spins then the total number of +spins + + align:start position:0% +spins + + + align:start position:0% +spins +then it's given by volume ID by a + + align:start position:0% +then it's given by volume ID by a + + + align:start position:0% +then it's given by volume ID by a +cube okay so this is essentially the + + align:start position:0% +cube okay so this is essentially the + + + align:start position:0% +cube okay so this is essentially the +number of deg freedom and this is given + + align:start position:0% +number of deg freedom and this is given + + + align:start position:0% +number of deg freedom and this is given +by a the area divide by a + + align:start position:0% +by a the area divide by a + + + align:start position:0% +by a the area divide by a +squ Time L divide by + + align:start position:0% + + + + align:start position:0% + +a and this can be much much greater + + align:start position:0% +a and this can be much much greater + + + align:start position:0% +a and this can be much much greater +than a ided by plank + + align:start position:0% +than a ided by plank + + + align:start position:0% +than a ided by plank +Square plank length Square for l so + + align:start position:0% +Square plank length Square for l so + + + align:start position:0% +Square plank length Square for l so +efficientcy large + + align:start position:0% + + + + align:start position:0% + +okay they are large + + align:start position:0% +okay they are large + + + align:start position:0% +okay they are large +enough so so if you have a long + + align:start position:0% +enough so so if you have a long + + + align:start position:0% +enough so so if you have a long +gravitational + + align:start position:0% +gravitational + + + align:start position:0% +gravitational +system then this B can be easily + + align:start position:0% + + + + align:start position:0% + +violated in + + align:start position:0% +violated in + + + align:start position:0% +violated in +particular this equation can also be + + align:start position:0% +particular this equation can also be + + + align:start position:0% +particular this equation can also be +violated because the because the um + + align:start position:0% +violated because the because the um + + + align:start position:0% +violated because the because the um +the dimension of the h + + align:start position:0% +the dimension of the h + + + align:start position:0% +the dimension of the h +space then in this case would be 2 to + + align:start position:0% +space then in this case would be 2 to + + + align:start position:0% +space then in this case would be 2 to +the power a + + align:start position:0% +the power a + + + align:start position:0% +the power a +cub and similarly so + + align:start position:0% +cub and similarly so + + + align:start position:0% +cub and similarly so +a so so the maximum + + align:start position:0% +a so so the maximum + + + align:start position:0% +a so so the maximum +entropy would be say V / a CU log two + + align:start position:0% +entropy would be say V / a CU log two + + + align:start position:0% +entropy would be say V / a CU log two +log two because it's a spin two system + + align:start position:0% +log two because it's a spin two system + + + align:start position:0% +log two because it's a spin two system +spin half system so this can be ner than + + align:start position:0% +spin half system so this can be ner than + + + align:start position:0% +spin half system so this can be ner than +entropy of a black + + align:start position:0% + + + + align:start position:0% + +hole + + align:start position:0% +hole + + + align:start position:0% +hole +so so it's + + align:start position:0% +so so it's + + + align:start position:0% +so so it's +key that we can see the gravitational + + align:start position:0% +key that we can see the gravitational + + + align:start position:0% +key that we can see the gravitational +systems okay only in gravitational + + align:start position:0% +systems okay only in gravitational + + + align:start position:0% +systems okay only in gravitational +systems you have this remarkable feature + + align:start position:0% +systems you have this remarkable feature + + + align:start position:0% +systems you have this remarkable feature +that if few uh since will + + align:start position:0% +that if few uh since will + + + align:start position:0% +that if few uh since will +collapse okay since will collapse uh + + align:start position:0% +collapse okay since will collapse uh + + + align:start position:0% +collapse okay since will collapse uh +will collapse and then you will have + + align:start position:0% +will collapse and then you will have + + + align:start position:0% +will collapse and then you will have +this uh upper limit provided by the + + align:start position:0% +this uh upper limit provided by the + + + align:start position:0% +this uh upper limit provided by the +black hole yes so in the real world + + align:start position:0% +black hole yes so in the real world + + + align:start position:0% +black hole yes so in the real world +every system is a gravitational system + + align:start position:0% +every system is a gravitational system + + + align:start position:0% +every system is a gravitational system +yeah so this is just in some sense this + + align:start position:0% +yeah so this is just in some sense this + + + align:start position:0% +yeah so this is just in some sense this +is not actually correct + + align:start position:0% +is not actually correct + + + align:start position:0% +is not actually correct +real yeah but you need this L to be not + + align:start position:0% +real yeah but you need this L to be not + + + align:start position:0% +real yeah but you need this L to be not +enough I see + + align:start position:0% + + + + align:start position:0% + +yeah yes so right in real world this + + align:start position:0% +yeah yes so right in real world this + + + align:start position:0% +yeah yes so right in real world this +bound has to be obeyed by systems so + + align:start position:0% +bound has to be obeyed by systems so + + + align:start position:0% +bound has to be obeyed by systems so +does that put some like bounds on UFT UV + + align:start position:0% +does that put some like bounds on UFT UV + + + align:start position:0% +does that put some like bounds on UFT UV +completions so in the real world this + + align:start position:0% +completions so in the real world this + + + align:start position:0% +completions so in the real world this +bound has to be aate by everything yeah + + align:start position:0% +bound has to be aate by everything yeah + + + align:start position:0% +bound has to be aate by everything yeah +so does that put some kind of + + align:start position:0% +so does that put some kind of + + + align:start position:0% +so does that put some kind of +restrictions on like Q of UV completion + + align:start position:0% +restrictions on like Q of UV completion + + + align:start position:0% +restrictions on like Q of UV completion +cuz we usually say it's you know + + align:start position:0% +cuz we usually say it's you know + + + align:start position:0% +cuz we usually say it's you know +infinite density degrees of freedom uh + + align:start position:0% +infinite density degrees of freedom uh + + + align:start position:0% +infinite density degrees of freedom uh +no because the because UV completion of + + align:start position:0% +no because the because UV completion of + + + align:start position:0% +no because the because UV completion of +qft is provided by gravity cor any Q I + + align:start position:0% +qft is provided by gravity cor any Q I + + + align:start position:0% +qft is provided by gravity cor any Q I +just mean like a scalar + + align:start position:0% +just mean like a scalar + + + align:start position:0% +just mean like a scalar +field then that's then that's not a + + align:start position:0% +field then that's then that's not a + + + align:start position:0% +field then that's then that's not a +theory of gravity right but if you have + + align:start position:0% +theory of gravity right but if you have + + + align:start position:0% +theory of gravity right but if you have +a scalar field in A Spacetime which has + + align:start position:0% +a scalar field in A Spacetime which has + + + align:start position:0% +a scalar field in A Spacetime which has +GR in it what is otherwise like FL yeah + + align:start position:0% +GR in it what is otherwise like FL yeah + + + align:start position:0% +GR in it what is otherwise like FL yeah +then the gr then the gravity will + + align:start position:0% +then the gr then the gravity will + + + align:start position:0% +then the gr then the gravity will +provide the UV completion of that scalar + + align:start position:0% +provide the UV completion of that scalar + + + align:start position:0% +provide the UV completion of that scalar +Fields + + align:start position:0% +Fields + + + align:start position:0% +Fields +yeah um + + align:start position:0% +yeah um + + + align:start position:0% +yeah um +right um I was going to say something + + align:start position:0% +right um I was going to say something + + + align:start position:0% +right um I was going to say something +else but I forgot + + align:start position:0% +else but I forgot + + + align:start position:0% +else but I forgot +um what about the ones that argue be + + align:start position:0% +um what about the ones that argue be + + + align:start position:0% +um what about the ones that argue be +complete what about the theories that RB + + align:start position:0% +complete what about the theories that RB + + + align:start position:0% +complete what about the theories that RB +complete at least + + align:start position:0% +complete at least + + + align:start position:0% +complete at least +formally uh sorry say it again uh the + + align:start position:0% +formally uh sorry say it again uh the + + + align:start position:0% +formally uh sorry say it again uh the +qfts that areg be complete yeah they + + align:start position:0% +qfts that areg be complete yeah they + + + align:start position:0% +qfts that areg be complete yeah they +still limited by gravity yeah the + + align:start position:0% +still limited by gravity yeah the + + + align:start position:0% +still limited by gravity yeah the +gravity will still provide something + + align:start position:0% +gravity will still provide something + + + align:start position:0% +gravity will still provide something +because qf have infinite number deg + + align:start position:0% +because qf have infinite number deg + + + align:start position:0% +because qf have infinite number deg +Freedom + + align:start position:0% +Freedom + + + align:start position:0% +Freedom +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +um yeah + + align:start position:0% +um yeah + + + align:start position:0% +um yeah +so so example of this for example you + + align:start position:0% +so so example of this for example you + + + align:start position:0% +so so example of this for example you +can sync a + + align:start position:0% +can sync a + + + align:start position:0% +can sync a +classroom say four or + + align:start position:0% +classroom say four or + + + align:start position:0% +classroom say four or +photons and then you can calculate + + align:start position:0% +photons and then you can calculate + + + align:start position:0% +photons and then you can calculate +entropy again that entropy will + + align:start position:0% +entropy again that entropy will + + + align:start position:0% +entropy again that entropy will +proportional to the volume so if you + + align:start position:0% +proportional to the volume so if you + + + align:start position:0% +proportional to the volume so if you +make the the classroom big enough then + + align:start position:0% +make the the classroom big enough then + + + align:start position:0% +make the the classroom big enough then +that will evate this + + align:start position:0% +that will evate this + + + align:start position:0% +that will evate this +bounds but it's a simple exercise for + + align:start position:0% +bounds but it's a simple exercise for + + + align:start position:0% +bounds but it's a simple exercise for +you to do yourself that if you put the + + align:start position:0% +you to do yourself that if you put the + + + align:start position:0% +you to do yourself that if you put the +classroom at the finite temperature + + align:start position:0% +classroom at the finite temperature + + + align:start position:0% +classroom at the finite temperature +Photon then when the room Bigg enough + + align:start position:0% +Photon then when the room Bigg enough + + + align:start position:0% +Photon then when the room Bigg enough +there always a + + align:start position:0% +there always a + + + align:start position:0% +there always a +radius uh uh that will collapse form a + + align:start position:0% +radius uh uh that will collapse form a + + + align:start position:0% +radius uh uh that will collapse form a +black hole before this SP is violated + + align:start position:0% +black hole before this SP is violated + + + align:start position:0% +black hole before this SP is violated +okay I think maybe I have this problem + + align:start position:0% +okay I think maybe I have this problem + + + align:start position:0% +okay I think maybe I have this problem +in the P forgot whether I have it or not + + align:start position:0% +in the P forgot whether I have it or not + + + align:start position:0% +in the P forgot whether I have it or not +yeah you can do this simple exercise + + align:start position:0% +yeah you can do this simple exercise + + + align:start position:0% +yeah you can do this simple exercise +yourself yeah just imagine you have a + + align:start position:0% +yourself yeah just imagine you have a + + + align:start position:0% +yourself yeah just imagine you have a +box of photons as some at any non zero + + align:start position:0% +box of photons as some at any non zero + + + align:start position:0% +box of photons as some at any non zero +temperature T and then when you put the + + align:start position:0% +temperature T and then when you put the + + + align:start position:0% +temperature T and then when you put the +Box big enough then then at certain + + align:start position:0% +Box big enough then then at certain + + + align:start position:0% +Box big enough then then at certain +point the uh this this whole box of + + align:start position:0% +point the uh this this whole box of + + + align:start position:0% +point the uh this this whole box of +photon will collapse form a black + + align:start position:0% +photon will collapse form a black + + + align:start position:0% +photon will collapse form a black +and uh + + align:start position:0% +and uh + + + align:start position:0% +and uh +um uh and that's when it form and that's + + align:start position:0% +um uh and that's when it form and that's + + + align:start position:0% +um uh and that's when it form and that's +within to make this bond to be + + align:start position:0% +within to make this bond to be + + + align:start position:0% +within to make this bond to be +satisfied so so what this + + align:start position:0% +satisfied so so what this + + + align:start position:0% +satisfied so so what this +means that if you have + + align:start position:0% + + + + align:start position:0% + +gravity the quantum + + align:start position:0% + + + + align:start position:0% + +gravity leads to a huge + + align:start position:0% + + + + align:start position:0% + +reduction + + align:start position:0% + + + + align:start position:0% + +of L + + align:start position:0% +of L + + + align:start position:0% +of L +Freedom + + align:start position:0% + + + + align:start position:0% + +okay it's really bounded by by your + + align:start position:0% +okay it's really bounded by by your + + + align:start position:0% +okay it's really bounded by by your +area now in previous + + align:start position:0% +area now in previous + + + align:start position:0% +area now in previous +AR you have a com + + align:start position:0% +AR you have a com + + + align:start position:0% +AR you have a com +F and so this Al + + align:start position:0% +F and so this Al + + + align:start position:0% +F and so this Al +apply we don't need to have + + align:start position:0% +apply we don't need to have + + + align:start position:0% +apply we don't need to have +a no yeah as I was uh uh + + align:start position:0% +a no yeah as I was uh uh + + + align:start position:0% +a no yeah as I was uh uh +power before uh if you have a conformal + + align:start position:0% +power before uh if you have a conformal + + + align:start position:0% +power before uh if you have a conformal +field Ser just by itself then there's no + + align:start position:0% +field Ser just by itself then there's no + + + align:start position:0% +field Ser just by itself then there's no +bound then there's no bound but if you + + align:start position:0% +bound then there's no bound but if you + + + align:start position:0% +bound then there's no bound but if you +couple this conformal F to gravity then + + align:start position:0% +couple this conformal F to gravity then + + + align:start position:0% +couple this conformal F to gravity then +as sufficiently high energy and then the + + align:start position:0% +as sufficiently high energy and then the + + + align:start position:0% +as sufficiently high energy and then the +degre freedom of this conformal filter + + align:start position:0% +degre freedom of this conformal filter + + + align:start position:0% +degre freedom of this conformal filter +must be reduced but if you just have a + + align:start position:0% +must be reduced but if you just have a + + + align:start position:0% +must be reduced but if you just have a +fter there's no bound no bound yeah yeah + + align:start position:0% +fter there's no bound no bound yeah yeah + + + align:start position:0% +fter there's no bound no bound yeah yeah +but you can ask what happens if we + + align:start position:0% +but you can ask what happens if we + + + align:start position:0% +but you can ask what happens if we +couple conformal F to gravity + + align:start position:0% +couple conformal F to gravity + + + align:start position:0% +couple conformal F to gravity +not even conformal fi just any Quantum + + align:start position:0% +not even conformal fi just any Quantum + + + align:start position:0% +not even conformal fi just any Quantum +field because any Quantum field have + + align:start position:0% +field because any Quantum field have + + + align:start position:0% +field because any Quantum field have +infinite number deg freedom and the + + align:start position:0% +infinite number deg freedom and the + + + align:start position:0% +infinite number deg freedom and the +number de is also proportional to the + + align:start position:0% +number de is also proportional to the + + + align:start position:0% +number de is also proportional to the +volume and uh um if you cou to gravity + + align:start position:0% +volume and uh um if you cou to gravity + + + align:start position:0% +volume and uh um if you cou to gravity +then this reduction must happen this + + align:start position:0% +then this reduction must happen this + + + align:start position:0% +then this reduction must happen this +reduction must happen + + align:start position:0% +reduction must happen + + + align:start position:0% +reduction must happen +Okay so now if we take a a small de of + + align:start position:0% +Okay so now if we take a a small de of + + + align:start position:0% +Okay so now if we take a a small de of +phase so we already have taken some Le + + align:start position:0% +phase so we already have taken some Le + + + align:start position:0% +phase so we already have taken some Le +of phase but let's take one more St Le + + align:start position:0% +of phase but let's take one more St Le + + + align:start position:0% +of phase but let's take one more St Le +phas then you can for formulate + + align:start position:0% +phas then you can for formulate + + + align:start position:0% +phas then you can for formulate +something called holographic + + align:start position:0% + + + + align:start position:0% + +principle so given that the number de + + align:start position:0% +principle so given that the number de + + + align:start position:0% +principle so given that the number de +Freedom inside the region is always + + align:start position:0% +Freedom inside the region is always + + + align:start position:0% +Freedom inside the region is always +bonded by the + + align:start position:0% +bonded by the + + + align:start position:0% +bonded by the +area and this area actually have a very + + align:start position:0% +area and this area actually have a very + + + align:start position:0% +area and this area actually have a very +nice way is area in the unit of a plank + + align:start position:0% +nice way is area in the unit of a plank + + + align:start position:0% +nice way is area in the unit of a plank +lens it look like you have a minimal + + align:start position:0% +lens it look like you have a minimal + + + align:start position:0% +lens it look like you have a minimal +lens minimal area which is a plank + + align:start position:0% +lens minimal area which is a plank + + + align:start position:0% +lens minimal area which is a plank +Square lens and just the area divided by + + align:start position:0% +Square lens and just the area divided by + + + align:start position:0% +Square lens and just the area divided by +that give you the total L Freedom okay + + align:start position:0% +that give you the total L Freedom okay + + + align:start position:0% +that give you the total L Freedom okay +so so if you try to uh extrapolate a + + align:start position:0% +so so if you try to uh extrapolate a + + + align:start position:0% +so so if you try to uh extrapolate a +little bit further then we have + + align:start position:0% +little bit further then we have + + + align:start position:0% +little bit further then we have +so-called holographic principle is said + + align:start position:0% +so-called holographic principle is said + + + align:start position:0% +so-called holographic principle is said +in quantum + + align:start position:0% + + + + align:start position:0% + +gravity a + + align:start position:0% + + + + align:start position:0% + +region of + + align:start position:0% + + + + align:start position:0% + +boundary area + + align:start position:0% + + + + align:start position:0% + +a can + + align:start position:0% +a can + + + align:start position:0% +a can +be + + align:start position:0% +be + + + align:start position:0% +be +fully + + align:start position:0% + + + + align:start position:0% + +described can be fully + + align:start position:0% +described can be fully + + + align:start position:0% +described can be fully +described + + align:start position:0% +described + + + align:start position:0% +described +by no more + + align:start position:0% + + + + align:start position:0% + +than so essentially just very + + align:start position:0% + + + + align:start position:0% + +a h + + align:start position:0% +a h + + + align:start position:0% +a h +hn + + align:start position:0% + + + + align:start position:0% + +a de + + align:start position:0% + + + + align:start position:0% + +freedom in other + + align:start position:0% +freedom in other + + + align:start position:0% +freedom in other +words one degree of + + align:start position:0% + + + + align:start position:0% + +Freedom per plunk + + align:start position:0% + + + + align:start position:0% + +area okay + + align:start position:0% + + + + align:start position:0% + +so this is + + align:start position:0% +so this is + + + align:start position:0% +so this is +the uh yeah just a rough formulation of + + align:start position:0% +the uh yeah just a rough formulation of + + + align:start position:0% +the uh yeah just a rough formulation of +the holographic + + align:start position:0% + + + + align:start position:0% + +principle + + align:start position:0% +principle + + + align:start position:0% +principle +so what we just + + align:start position:0% +so what we just + + + align:start position:0% +so what we just +said it just + + align:start position:0% +said it just + + + align:start position:0% +said it just +highlights a point we made + + align:start position:0% +highlights a point we made + + + align:start position:0% +highlights a point we made +earlier is that even though like from + + align:start position:0% +earlier is that even though like from + + + align:start position:0% +earlier is that even though like from +dimensional + + align:start position:0% +dimensional + + + align:start position:0% +dimensional +analysis that the quantum gravity is + + align:start position:0% +analysis that the quantum gravity is + + + align:start position:0% +analysis that the quantum gravity is +always is only operating say at plank + + align:start position:0% +always is only operating say at plank + + + align:start position:0% +always is only operating say at plank +scale say at plank mass or plank length + + align:start position:0% +scale say at plank mass or plank length + + + align:start position:0% +scale say at plank mass or plank length +Etc but we see that the black + + align:start position:0% +Etc but we see that the black + + + align:start position:0% +Etc but we see that the black +hole actually brings the Quant gravity + + align:start position:0% +hole actually brings the Quant gravity + + + align:start position:0% +hole actually brings the Quant gravity +really to microscopic level okay because + + align:start position:0% +really to microscopic level okay because + + + align:start position:0% +really to microscopic level okay because +these are the really microscopic + + align:start position:0% +these are the really microscopic + + + align:start position:0% +these are the really microscopic +statement uh can apply to regions of + + align:start position:0% +statement uh can apply to regions of + + + align:start position:0% +statement uh can apply to regions of +arbitrary sides but some somehow they + + align:start position:0% +arbitrary sides but some somehow they + + + align:start position:0% +arbitrary sides but some somehow they +limited by constraint of con gravity + + align:start position:0% +limited by constraint of con gravity + + + align:start position:0% +limited by constraint of con gravity +okay so this is the a remarkable um um + + align:start position:0% +okay so this is the a remarkable um um + + + align:start position:0% +okay so this is the a remarkable um um +manifestation of the quantum + + align:start position:0% +manifestation of the quantum + + + align:start position:0% +manifestation of the quantum +effect any questions on this yes about + + align:start position:0% + + + + align:start position:0% + +dimensiones oh yeah yeah this you can + + align:start position:0% +dimensiones oh yeah yeah this you can + + + align:start position:0% +dimensiones oh yeah yeah this you can +generalize to any Dimension just always + + align:start position:0% +generalize to any Dimension just always + + + align:start position:0% +generalize to any Dimension just always +Co Dimension + + align:start position:0% +Co Dimension + + + align:start position:0% +Co Dimension +two so if you leave in five + + align:start position:0% +two so if you leave in five + + + align:start position:0% +two so if you leave in five +dimension then become three dimension + + align:start position:0% +dimension then become three dimension + + + align:start position:0% +dimension then become three dimension +yeah it's always core Dimension One in + + align:start position:0% +yeah it's always core Dimension One in + + + align:start position:0% +yeah it's always core Dimension One in +the spatial + + align:start position:0% +the spatial + + + align:start position:0% +the spatial +region because the black + + align:start position:0% +region because the black + + + align:start position:0% +region because the black +hole Yeah black hole just area of the + + align:start position:0% +hole Yeah black hole just area of the + + + align:start position:0% +hole Yeah black hole just area of the +black hole is always C Dimension One in + + align:start position:0% +black hole is always C Dimension One in + + + align:start position:0% +black hole is always C Dimension One in +term spatial + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% + + + + align:start position:0% + +diere yeah 10 dimensional space the + + align:start position:0% +diere yeah 10 dimensional space the + + + align:start position:0% +diere yeah 10 dimensional space the +naivity this would be constrained by + + align:start position:0% +naivity this would be constrained by + + + align:start position:0% +naivity this would be constrained by +eight + + align:start position:0% +eight + + + align:start position:0% +eight +dimensional surface + + align:start position:0% +dimensional surface + + + align:start position:0% +dimensional surface +yeah yeah just no matter what dimension + + align:start position:0% +yeah yeah just no matter what dimension + + + align:start position:0% +yeah yeah just no matter what dimension +it's always constrained by the surface + + align:start position:0% +it's always constrained by the surface + + + align:start position:0% +it's always constrained by the surface +not constrained by the volume no matter + + align:start position:0% +not constrained by the volume no matter + + + align:start position:0% +not constrained by the volume no matter +in what + + align:start position:0% + + + + align:start position:0% + +dimension other + + align:start position:0% +dimension other + + + align:start position:0% +dimension other +questions there yeah so it seems like we + + align:start position:0% +questions there yeah so it seems like we + + + align:start position:0% +questions there yeah so it seems like we +must we are like constraining a system + + align:start position:0% +must we are like constraining a system + + + align:start position:0% +must we are like constraining a system +ACC the that it's number of states for + + align:start position:0% +ACC the that it's number of states for + + + align:start position:0% +ACC the that it's number of states for +given energy must grow slower some + + align:start position:0% +given energy must grow slower some + + + align:start position:0% +given energy must grow slower some +because must be + + align:start position:0% +because must be + + + align:start position:0% +because must be +lower yeah the number + + align:start position:0% +lower yeah the number + + + align:start position:0% +lower yeah the number +must yeah just say it just say + + align:start position:0% +must yeah just say it just say + + + align:start position:0% +must yeah just say it just say +um uh essentially what we said earlier + + align:start position:0% +um uh essentially what we said earlier + + + align:start position:0% +um uh essentially what we said earlier +is said if you're in the serial quantum + + align:start position:0% +is said if you're in the serial quantum + + + align:start position:0% +is said if you're in the serial quantum +gravity there's a cut off on the maximum + + align:start position:0% +gravity there's a cut off on the maximum + + + align:start position:0% +gravity there's a cut off on the maximum +energy you can have and uh and and + + align:start position:0% +energy you can have and uh and and + + + align:start position:0% +energy you can have and uh and and +there's a cut also on the maximum energy + + align:start position:0% +there's a cut also on the maximum energy + + + align:start position:0% +there's a cut also on the maximum energy +you can have because otherwise you form + + align:start position:0% +you can have because otherwise you form + + + align:start position:0% +you can have because otherwise you form +a black hole and then and then that's + + align:start position:0% +a black hole and then and then that's + + + align:start position:0% +a black hole and then and then that's +that cut off trans translate into the + + align:start position:0% +that cut off trans translate into the + + + align:start position:0% +that cut off trans translate into the +statement about the entropy and and the + + align:start position:0% +statement about the entropy and and the + + + align:start position:0% +statement about the entropy and and the +into the number Freedom yes I mean + + align:start position:0% +into the number Freedom yes I mean + + + align:start position:0% +into the number Freedom yes I mean +because much easier yeah yeah for + + align:start position:0% +because much easier yeah yeah for + + + align:start position:0% +because much easier yeah yeah for +example we have a first we start with a + + align:start position:0% +example we have a first we start with a + + + align:start position:0% +example we have a first we start with a +simple series L maybe for example we add + + align:start position:0% +simple series L maybe for example we add + + + align:start position:0% +simple series L maybe for example we add +for example stand model then we add + + align:start position:0% +for example stand model then we add + + + align:start position:0% +for example stand model then we add +super symmetry then the energy Spectrum + + align:start position:0% +super symmetry then the energy Spectrum + + + align:start position:0% +super symmetry then the energy Spectrum +the the limiting energy is there but the + + align:start position:0% +the the limiting energy is there but the + + + align:start position:0% +the the limiting energy is there but the +number of her space state is more and we + + align:start position:0% +number of her space state is more and we + + + align:start position:0% +number of her space state is more and we +can keep doing things like that + + align:start position:0% +can keep doing things like that + + + align:start position:0% +can keep doing things like that +yeah but we can't because it must be + + align:start position:0% +yeah but we can't because it must be + + + align:start position:0% +yeah but we can't because it must be +below this value yeah but but you see + + align:start position:0% +below this value yeah but but you see + + + align:start position:0% +below this value yeah but but you see +there's something about the volume here + + align:start position:0% +there's something about the volume here + + + align:start position:0% +there's something about the volume here +uh uh you have to talk about the within + + align:start position:0% +uh uh you have to talk about the within + + + align:start position:0% +uh uh you have to talk about the within +some region uh uh of course abstractly + + align:start position:0% +some region uh uh of course abstractly + + + align:start position:0% +some region uh uh of course abstractly +you can uh you can put some yeah maybe + + align:start position:0% +you can uh you can put some yeah maybe + + + align:start position:0% +you can uh you can put some yeah maybe +I'm not getting your + + align:start position:0% +I'm not getting your + + + align:start position:0% +I'm not getting your +question I you say not I always think we + + align:start position:0% +question I you say not I always think we + + + align:start position:0% +question I you say not I always think we +can + + align:start position:0% +can + + + align:start position:0% +can +just um for example say the energy bound + + align:start position:0% +just um for example say the energy bound + + + align:start position:0% +just um for example say the energy bound +is here and below this how many St we + + align:start position:0% +is here and below this how many St we + + + align:start position:0% +is here and below this how many St we +could have no no no this is not the dire + + align:start position:0% +could have no no no this is not the dire + + + align:start position:0% +could have no no no this is not the dire +in ter the enty energy Bond uh this is + + align:start position:0% +in ter the enty energy Bond uh this is + + + align:start position:0% +in ter the enty energy Bond uh this is +in the end is the is the is the bound on + + align:start position:0% +in the end is the is the is the bound on + + + align:start position:0% +in the end is the is the is the bound on +the on the + + align:start position:0% +the on the + + + align:start position:0% +the on the +um on the lung body F you can put inside + + align:start position:0% +um on the lung body F you can put inside + + + align:start position:0% +um on the lung body F you can put inside +a + + align:start position:0% +a + + + align:start position:0% +a +region if you put too many deg F inside + + align:start position:0% +region if you put too many deg F inside + + + align:start position:0% +region if you put too many deg F inside +the region then you need to enlarge the + + align:start position:0% +the region then you need to enlarge the + + + align:start position:0% +the region then you need to enlarge the +region yeah just say it's look like the + + align:start position:0% +region yeah just say it's look like the + + + align:start position:0% +region yeah just say it's look like the +number of is incomparable something + + align:start position:0% + + + + align:start position:0% + +that + + align:start position:0% +that + + + align:start position:0% +that +yeah understand shouldn't isolated + + align:start position:0% +yeah understand shouldn't isolated + + + align:start position:0% +yeah understand shouldn't isolated +system means also included the Machinery + + align:start position:0% +system means also included the Machinery + + + align:start position:0% +system means also included the Machinery +to do this things no I'm just saying you + + align:start position:0% +to do this things no I'm just saying you + + + align:start position:0% +to do this things no I'm just saying you +start with isolated system then you can + + align:start position:0% +start with isolated system then you can + + + align:start position:0% +start with isolated system then you can +add something to that isolated + + align:start position:0% +add something to that isolated + + + align:start position:0% +add something to that isolated +system but what about we take matters + + align:start position:0% +system but what about we take matters + + + align:start position:0% +system but what about we take matters +out of the black + + align:start position:0% +out of the black + + + align:start position:0% +out of the black +this no no you take it no that's thing + + align:start position:0% +this no no you take it no that's thing + + + align:start position:0% +this no no you take it no that's thing +that that actually see does not have to + + align:start position:0% +that that actually see does not have to + + + align:start position:0% +that that actually see does not have to +be a black + + align:start position:0% +be a black + + + align:start position:0% +be a black +hole it can be anything it just can be + + align:start position:0% +hole it can be anything it just can be + + + align:start position:0% +hole it can be anything it just can be +anything so if we instead putting energy + + align:start position:0% +anything so if we instead putting energy + + + align:start position:0% +anything so if we instead putting energy +inside we take energy out yeah you take + + align:start position:0% +inside we take energy out yeah you take + + + align:start position:0% +inside we take energy out yeah you take +entropy will decrease yeah just take + + align:start position:0% +entropy will decrease yeah just take + + + align:start position:0% +entropy will decrease yeah just take +entropy out + + align:start position:0% +entropy out + + + align:start position:0% +entropy out +yeah then this spond will be even more + + align:start position:0% + + + + align:start position:0% + +satisfied a question there that the the + + align:start position:0% +satisfied a question there that the the + + + align:start position:0% +satisfied a question there that the the +the degree of freen yeah I mean l of no + + align:start position:0% +the degree of freen yeah I mean l of no + + + align:start position:0% +the degree of freen yeah I mean l of no +no n is the dimension of the h + + align:start position:0% +no n is the dimension of the h + + + align:start position:0% +no n is the dimension of the h +space n is the dimension of the h space + + align:start position:0% +space n is the dimension of the h space + + + align:start position:0% +space n is the dimension of the h space +that's what I call n here n Dimension h + + align:start position:0% + + + + align:start position:0% + +space typically the L of the dimension + + align:start position:0% +space typically the L of the dimension + + + align:start position:0% +space typically the L of the dimension +of h space is exponential of the L + + align:start position:0% +of h space is exponential of the L + + + align:start position:0% +of h space is exponential of the L +Freedom okay just look at here just look + + align:start position:0% +Freedom okay just look at here just look + + + align:start position:0% +Freedom okay just look at here just look +at here + + align:start position:0% +at here + + + align:start position:0% +at here +yeah any other + + align:start position:0% +yeah any other + + + align:start position:0% +yeah any other +questions + + align:start position:0% +questions + + + align:start position:0% +questions +okay um in + + align:start position:0% +okay um in + + + align:start position:0% +okay um in +the if we have a Quantum field Theory it + + align:start position:0% +the if we have a Quantum field Theory it + + + align:start position:0% +the if we have a Quantum field Theory it +has C vacuum energy right and then if + + align:start position:0% +has C vacuum energy right and then if + + + align:start position:0% +has C vacuum energy right and then if +you now like you know consider that to + + align:start position:0% +you now like you know consider that to + + + align:start position:0% +you now like you know consider that to +be the vacuum energy and you expand it + + align:start position:0% +be the vacuum energy and you expand it + + + align:start position:0% +be the vacuum energy and you expand it +at some point it will actually collapse + + align:start position:0% +at some point it will actually collapse + + + align:start position:0% +at some point it will actually collapse +into a black hole so like if you take + + align:start position:0% +into a black hole so like if you take + + + align:start position:0% +into a black hole so like if you take +the vacuum energy to be that predicted + + align:start position:0% +the vacuum energy to be that predicted + + + align:start position:0% +the vacuum energy to be that predicted +by T of then uh for like the universe it + + align:start position:0% +by T of then uh for like the universe it + + + align:start position:0% +by T of then uh for like the universe it +would not work even theoretically I mean + + align:start position:0% +would not work even theoretically I mean + + + align:start position:0% +would not work even theoretically I mean +I know the cosmological constant is like + + align:start position:0% +I know the cosmological constant is like + + + align:start position:0% +I know the cosmological constant is like +120 orders less but yeah that's a bit + + align:start position:0% +120 orders less but yeah that's a bit + + + align:start position:0% +120 orders less but yeah that's a bit +tricky uh because the um yeah so the + + align:start position:0% +tricky uh because the um yeah so the + + + align:start position:0% +tricky uh because the um yeah so the +vacuum energy will make it in to say + + align:start position:0% +vacuum energy will make it in to say + + + align:start position:0% +vacuum energy will make it in to say +depend on whether vacuum energy is + + align:start position:0% +depend on whether vacuum energy is + + + align:start position:0% +depend on whether vacuum energy is +positive or netive make it into de anti + + align:start position:0% +positive or netive make it into de anti + + + align:start position:0% +positive or netive make it into de anti +deer then then yeah then you try to see + + align:start position:0% +deer then then yeah then you try to see + + + align:start position:0% +deer then then yeah then you try to see +whether yeah um it depend on + + align:start position:0% +whether yeah um it depend on + + + align:start position:0% +whether yeah um it depend on +details but if you go big enough it's + + align:start position:0% +details but if you go big enough it's + + + align:start position:0% +details but if you go big enough it's +going to collapse for or no no not + + align:start position:0% +going to collapse for or no no not + + + align:start position:0% +going to collapse for or no no not +necess I'm just saying that you have to + + align:start position:0% +necess I'm just saying that you have to + + + align:start position:0% +necess I'm just saying that you have to +formulate a little bit differently + + align:start position:0% +formulate a little bit differently + + + align:start position:0% +formulate a little bit differently +you're talking about a particular state + + align:start position:0% +you're talking about a particular state + + + align:start position:0% +you're talking about a particular state +of certain energy to cap to gravity then + + align:start position:0% +of certain energy to cap to gravity then + + + align:start position:0% +of certain energy to cap to gravity then +you just take that state cap to gravity + + align:start position:0% +you just take that state cap to gravity + + + align:start position:0% +you just take that state cap to gravity +to see what you get + + align:start position:0% +to see what you get + + + align:start position:0% +to see what you get +yeah then ask questions from + + align:start position:0% +yeah then ask questions from + + + align:start position:0% +yeah then ask questions from +there yeah good so now let's move to a + + align:start position:0% +there yeah good so now let's move to a + + + align:start position:0% +there yeah good so now let's move to a +topic still is in the + + align:start position:0% +topic still is in the + + + align:start position:0% +topic still is in the +preparation to go to the to go to The + + align:start position:0% +preparation to go to the to go to The + + + align:start position:0% +preparation to go to the to go to The +Duality but we need the a lot piece of + + align:start position:0% +Duality but we need the a lot piece of + + + align:start position:0% +Duality but we need the a lot piece of +important + + align:start position:0% + + + + align:start position:0% + +intuition in order to fully appreciate + + align:start position:0% +intuition in order to fully appreciate + + + align:start position:0% +intuition in order to fully appreciate +the duality + + align:start position:0% +the duality + + + align:start position:0% +the duality +and and this piece of + + align:start position:0% +and and this piece of + + + align:start position:0% +and and this piece of +intuition is n + + align:start position:0% + + + + align:start position:0% + +Series yeah let me call it n Matrix + + align:start position:0% + + + + align:start position:0% + +series + + align:start position:0% +series + + + align:start position:0% +series +okay so now we want to look at the now + + align:start position:0% +okay so now we want to look at the now + + + align:start position:0% +okay so now we want to look at the now +we try to look at the uh hint for gra uh + + align:start position:0% +we try to look at the uh hint for gra uh + + + align:start position:0% +we try to look at the uh hint for gra uh +for holographic duality from the FI + + align:start position:0% +for holographic duality from the FI + + + align:start position:0% +for holographic duality from the FI +series side okay from the FI series side + + align:start position:0% +series side okay from the FI series side + + + align:start position:0% +series side okay from the FI series side +so so so far we have been talking about + + align:start position:0% +so so so far we have been talking about + + + align:start position:0% +so so so far we have been talking about +the hint + + align:start position:0% +the hint + + + align:start position:0% +the hint +photography from the gravity + + align:start position:0% +photography from the gravity + + + align:start position:0% +photography from the gravity +side uh and now we look at it from the + + align:start position:0% +side uh and now we look at it from the + + + align:start position:0% +side uh and now we look at it from the +field series side to see actually from + + align:start position:0% +field series side to see actually from + + + align:start position:0% +field series side to see actually from +fi series side there's also some hint to + + align:start position:0% +fi series side there's also some hint to + + + align:start position:0% +fi series side there's also some hint to +relate a long gravity system to a + + align:start position:0% +relate a long gravity system to a + + + align:start position:0% +relate a long gravity system to a +gravity system okay so let's start with + + align:start position:0% + + + + align:start position:0% + +qcd uh + + align:start position:0% +qcd uh + + + align:start position:0% +qcd uh +um so qcd is su3 gauge + + align:start position:0% + + + + align:start position:0% + +Theory plus + + align:start position:0% + + + + align:start position:0% + +quar + + align:start position:0% +quar + + + align:start position:0% +quar +okay so we can so let me just write down + + align:start position:0% +okay so we can so let me just write down + + + align:start position:0% +okay so we can so let me just write down +it's a + + align:start position:0% + + + + align:start position:0% + +ground + + align:start position:0% + + + + align:start position:0% + +okay so this + + align:start position:0% +okay so this + + + align:start position:0% +okay so this +F describe the gluon field and this side + + align:start position:0% +F describe the gluon field and this side + + + align:start position:0% +F describe the gluon field and this side +describe the clocks okay so this a so + + align:start position:0% +describe the clocks okay so this a so + + + align:start position:0% +describe the clocks okay so this a so +this F is built + + align:start position:0% +this F is built + + + align:start position:0% +this F is built +out of the standard partial mu a mu + + align:start position:0% +out of the standard partial mu a mu + + + align:start position:0% +out of the standard partial mu a mu +minus partial mu a mu + + align:start position:0% +minus partial mu a mu + + + align:start position:0% +minus partial mu a mu +minus a mu a + + align:start position:0% +minus a mu a + + + align:start position:0% +minus a mu a +mu and May and a mu each gaug + + align:start position:0% +mu and May and a mu each gaug + + + align:start position:0% +mu and May and a mu each gaug +field is a 3X3 commission + + align:start position:0% + + + + align:start position:0% + +Matrix okay so this are 3 * 3 mission + + align:start position:0% + + + + align:start position:0% + +Matrix so this is using the Matrix + + align:start position:0% +Matrix so this is using the Matrix + + + align:start position:0% +Matrix so this is using the Matrix +notation so f is also a matrix so + + align:start position:0% +notation so f is also a matrix so + + + align:start position:0% +notation so f is also a matrix so +there's a trace here + + align:start position:0% +there's a trace here + + + align:start position:0% +there's a trace here +okay permission + + align:start position:0% + + + + align:start position:0% + +Matrix and the TA is just the generators + + align:start position:0% +Matrix and the TA is just the generators + + + align:start position:0% +Matrix and the TA is just the generators +of su + + align:start position:0% +of su + + + align:start position:0% +of su +su3 + + align:start position:0% +su3 + + + align:start position:0% +su3 +okay so it doesn't matter if you don't + + align:start position:0% +okay so it doesn't matter if you don't + + + align:start position:0% +okay so it doesn't matter if you don't +know qcd it doesn't matter if you have + + align:start position:0% +know qcd it doesn't matter if you have + + + align:start position:0% +know qcd it doesn't matter if you have +not seen qcd before the only thing + + align:start position:0% +not seen qcd before the only thing + + + align:start position:0% +not seen qcd before the only thing +matters is just to remember that qcd is + + align:start position:0% +matters is just to remember that qcd is + + + align:start position:0% +matters is just to remember that qcd is +a theory of + + align:start position:0% +a theory of + + + align:start position:0% +a theory of +matrices PD is a theory of three 3x3 + + align:start position:0% +matrices PD is a theory of three 3x3 + + + align:start position:0% +matrices PD is a theory of three 3x3 +matrices okay so the Gran field it's a + + align:start position:0% +matrices okay so the Gran field it's a + + + align:start position:0% +matrices okay so the Gran field it's a +3X3 matrices it's it's it's it's a + + align:start position:0% +3X3 matrices it's it's it's it's a + + + align:start position:0% +3X3 matrices it's it's it's it's a +described by + + align:start position:0% +described by + + + align:start position:0% +described by +matrices so of course the one of the + + align:start position:0% +matrices so of course the one of the + + + align:start position:0% +matrices so of course the one of the +remarkable thing about the + + align:start position:0% +remarkable thing about the + + + align:start position:0% +remarkable thing about the +qcd what's the most remarkable thing + + align:start position:0% +qcd what's the most remarkable thing + + + align:start position:0% +qcd what's the most remarkable thing +about qcd do you + + align:start position:0% + + + + align:start position:0% + +know yeah that's + + align:start position:0% +know yeah that's + + + align:start position:0% +know yeah that's +one and what other remarkable thing + + align:start position:0% +one and what other remarkable thing + + + align:start position:0% +one and what other remarkable thing +about the Q + + align:start position:0% + + + + align:start position:0% + +yeah it's related to that conf yeah + + align:start position:0% +yeah it's related to that conf yeah + + + align:start position:0% +yeah it's related to that conf yeah +confinement is also related to that it's + + align:start position:0% +confinement is also related to that it's + + + align:start position:0% +confinement is also related to that it's +just yeah one of the one of most + + align:start position:0% +just yeah one of the one of most + + + align:start position:0% +just yeah one of the one of most +remarkable one of the most remarkable + + align:start position:0% +remarkable one of the most remarkable + + + align:start position:0% +remarkable one of the most remarkable +thing about QD is still not + + align:start position:0% + + + + align:start position:0% + +solvable and the reason it's not + + align:start position:0% +solvable and the reason it's not + + + align:start position:0% +solvable and the reason it's not +solvable is is because when you go to + + align:start position:0% +solvable is is because when you go to + + + align:start position:0% +solvable is is because when you go to +low energies the company becomes strong + + align:start position:0% +low energies the company becomes strong + + + align:start position:0% +low energies the company becomes strong +then we don't know how to deal with it + + align:start position:0% +then we don't know how to deal with it + + + align:start position:0% +then we don't know how to deal with it +okay um so we still don't know how to + + align:start position:0% +okay um so we still don't know how to + + + align:start position:0% +okay um so we still don't know how to +calculated from first principle of + + align:start position:0% +calculated from first principle of + + + align:start position:0% +calculated from first principle of +course we can put it on the computer but + + align:start position:0% +course we can put it on the computer but + + + align:start position:0% +course we can put it on the computer but +uh but just from the um uh in terms of + + align:start position:0% +uh but just from the um uh in terms of + + + align:start position:0% +uh but just from the um uh in terms of +theoretical understanding it's + + align:start position:0% +theoretical understanding it's + + + align:start position:0% +theoretical understanding it's +hard so in + + align:start position:0% + + + + align:start position:0% + +1974 so this is old + + align:start position:0% +1974 so this is old + + + align:start position:0% +1974 so this is old +problem so starting in 1974 people + + align:start position:0% +problem so starting in 1974 people + + + align:start position:0% +problem so starting in 1974 people +starting 1971 people already tried to + + align:start position:0% +starting 1971 people already tried to + + + align:start position:0% +starting 1971 people already tried to +solve + + align:start position:0% +solve + + + align:start position:0% +solve +it so in 1974 so the big problem of this + + align:start position:0% +it so in 1974 so the big problem of this + + + align:start position:0% +it so in 1974 so the big problem of this +thing is that in Quantum fil normally we + + align:start position:0% +thing is that in Quantum fil normally we + + + align:start position:0% +thing is that in Quantum fil normally we +do expansions okay say we find some + + align:start position:0% +do expansions okay say we find some + + + align:start position:0% +do expansions okay say we find some +starting point so in physics that we + + align:start position:0% +starting point so in physics that we + + + align:start position:0% +starting point so in physics that we +always do we find a starting point which + + align:start position:0% +always do we find a starting point which + + + align:start position:0% +always do we find a starting point which +can be solved then we expand around that + + align:start position:0% +can be solved then we expand around that + + + align:start position:0% +can be solved then we expand around that +starting point and that starting point + + align:start position:0% +starting point and that starting point + + + align:start position:0% +starting point and that starting point +is often a free + + align:start position:0% +is often a free + + + align:start position:0% +is often a free +Theory and uh then we we expand about + + align:start position:0% +Theory and uh then we we expand about + + + align:start position:0% +Theory and uh then we we expand about +the free + + align:start position:0% +the free + + + align:start position:0% +the free +Theory so so the difficult thing about + + align:start position:0% +Theory so so the difficult thing about + + + align:start position:0% +Theory so so the difficult thing about +this + + align:start position:0% +this + + + align:start position:0% +this +theory is that first it's it's hard when + + align:start position:0% +theory is that first it's it's hard when + + + align:start position:0% +theory is that first it's it's hard when +you go to low energies first it's hard + + align:start position:0% +you go to low energies first it's hard + + + align:start position:0% +you go to low energies first it's hard +to find the starting point and the + + align:start position:0% +to find the starting point and the + + + align:start position:0% +to find the starting point and the +second is that there's nothing to expand + + align:start position:0% +second is that there's nothing to expand + + + align:start position:0% +second is that there's nothing to expand +because there's no small parameters okay + + align:start position:0% +because there's no small parameters okay + + + align:start position:0% +because there's no small parameters okay +there's no small parameters uh uh when + + align:start position:0% +there's no small parameters uh uh when + + + align:start position:0% +there's no small parameters uh uh when +you need to expand you always need a + + align:start position:0% +you need to expand you always need a + + + align:start position:0% +you need to expand you always need a +small + + align:start position:0% +small + + + align:start position:0% +small +parameter so so in 1974 to H come up + + align:start position:0% +parameter so so in 1974 to H come up + + + align:start position:0% +parameter so so in 1974 to H come up +with a a very nice idea he say this is + + align:start position:0% + + + + align:start position:0% + +su3 he said let's just think take the + + align:start position:0% +su3 he said let's just think take the + + + align:start position:0% +su3 he said let's just think take the +number of + + align:start position:0% +number of + + + align:start position:0% +number of +color + + align:start position:0% + + + + align:start position:0% + +which is n equal + + align:start position:0% +which is n equal + + + align:start position:0% +which is n equal +3 as a + + align:start position:0% + + + + align:start position:0% + +parameter so even even though in real + + align:start position:0% +parameter so even even though in real + + + align:start position:0% +parameter so even even though in real +life he said there + + align:start position:0% +life he said there + + + align:start position:0% +life he said there +only three yeah there's only three type + + align:start position:0% +only three yeah there's only three type + + + align:start position:0% +only three yeah there's only three type +of colors but let's imagine uh we treat + + align:start position:0% +of colors but let's imagine uh we treat + + + align:start position:0% +of colors but let's imagine uh we treat +it as a three parameter okay so which + + align:start position:0% +it as a three parameter okay so which + + + align:start position:0% +it as a three parameter okay so which +this just implies say you + + align:start position:0% +this just implies say you + + + align:start position:0% +this just implies say you +promote the gauge + + align:start position:0% +promote the gauge + + + align:start position:0% +promote the gauge +field to M byn matrices M byn commission + + align:start position:0% +field to M byn matrices M byn commission + + + align:start position:0% +field to M byn matrices M byn commission +matrices + + align:start position:0% + + + + align:start position:0% + +okay okay you say let's just treat this + + align:start position:0% +okay okay you say let's just treat this + + + align:start position:0% +okay okay you say let's just treat this +by in terms of M by m + + align:start position:0% +by in terms of M by m + + + align:start position:0% +by in terms of M by m +matrices and then let's consider angle + + align:start position:0% +matrices and then let's consider angle + + + align:start position:0% +matrices and then let's consider angle +to Infinity + + align:start position:0% + + + + align:start position:0% + +limit + + align:start position:0% + + + + align:start position:0% + +okay so let's consider Ang go Infinity + + align:start position:0% + + + + align:start position:0% + +mid so so he reasoned if in the infinite + + align:start position:0% +mid so so he reasoned if in the infinite + + + align:start position:0% +mid so so he reasoned if in the infinite +limit is sufficiently simple then maybe + + align:start position:0% +limit is sufficiently simple then maybe + + + align:start position:0% +limit is sufficiently simple then maybe +maybe we can solve that limit and then + + align:start position:0% +maybe we can solve that limit and then + + + align:start position:0% +maybe we can solve that limit and then +do one/ + + align:start position:0% +do one/ + + + align:start position:0% +do one/ +expansion one n then it's a small + + align:start position:0% +expansion one n then it's a small + + + align:start position:0% +expansion one n then it's a small +parameter then we can Tre One n as a + + align:start position:0% +parameter then we can Tre One n as a + + + align:start position:0% +parameter then we can Tre One n as a +small parameter and then do one + + align:start position:0% +small parameter and then do one + + + align:start position:0% +small parameter and then do one +expansion + + align:start position:0% +expansion + + + align:start position:0% +expansion +okay so that's the rough idea and then + + align:start position:0% +okay so that's the rough idea and then + + + align:start position:0% +okay so that's the rough idea and then +you get a small paret one/ n so in real + + align:start position:0% +you get a small paret one/ n so in real + + + align:start position:0% +you get a small paret one/ n so in real +life n will be three so one over three + + align:start position:0% +life n will be three so one over three + + + align:start position:0% +life n will be three so one over three +um it's not very small but it's at least + + align:start position:0% +um it's not very small but it's at least + + + align:start position:0% +um it's not very small but it's at least +smaller than + + align:start position:0% +smaller than + + + align:start position:0% +smaller than +one okay so so this turns out to be an + + align:start position:0% +one okay so so this turns out to be an + + + align:start position:0% +one okay so so this turns out to be an +ingenious idea + + align:start position:0% +ingenious idea + + + align:start position:0% +ingenious idea +T out to be ingenious idea but + + align:start position:0% +T out to be ingenious idea but + + + align:start position:0% +T out to be ingenious idea but +unfortunately qcd still cannot be solved + + align:start position:0% +unfortunately qcd still cannot be solved + + + align:start position:0% +unfortunately qcd still cannot be solved +this + + align:start position:0% + + + + align:start position:0% + +way but there's a surprise but there's a + + align:start position:0% +way but there's a surprise but there's a + + + align:start position:0% +way but there's a surprise but there's a +surprise so still you cannot solve this + + align:start position:0% +surprise so still you cannot solve this + + + align:start position:0% +surprise so still you cannot solve this +way uh even angle to infite limit turns + + align:start position:0% +way uh even angle to infite limit turns + + + align:start position:0% +way uh even angle to infite limit turns +out to be too hot but this a surprise it + + align:start position:0% +out to be too hot but this a surprise it + + + align:start position:0% +out to be too hot but this a surprise it +turns + + align:start position:0% + + + + align:start position:0% + +out out this one + + align:start position:0% + + + + align:start position:0% + +expansion give you a string + + align:start position:0% + + + + align:start position:0% + +theory + + align:start position:0% +theory + + + align:start position:0% +theory +okay so I will now explain this + + align:start position:0% +okay so I will now explain this + + + align:start position:0% +okay so I will now explain this +okay so not explain this so so this a + + align:start position:0% +okay so not explain this so so this a + + + align:start position:0% +okay so not explain this so so this a +byproduct of his lar expansion is said + + align:start position:0% +byproduct of his lar expansion is said + + + align:start position:0% +byproduct of his lar expansion is said +you find that this + + align:start position:0% +you find that this + + + align:start position:0% +you find that this +actually such a gaug series actually + + align:start position:0% +actually such a gaug series actually + + + align:start position:0% +actually such a gaug series actually +secretly a string series + + align:start position:0% + + + + align:start position:0% + +so the + + align:start position:0% + + + + align:start position:0% + +key is that this field are matrices + + align:start position:0% + + + + align:start position:0% + +okay so so the key reason this emerges + + align:start position:0% +okay so so the key reason this emerges + + + align:start position:0% +okay so so the key reason this emerges +is because we are working with field + + align:start position:0% +is because we are working with field + + + align:start position:0% +is because we are working with field +which are + + align:start position:0% +which are + + + align:start position:0% +which are +matrices so so I will uh so to to + + align:start position:0% +matrices so so I will uh so to to + + + align:start position:0% +matrices so so I will uh so to to +illustrate + + align:start position:0% +illustrate + + + align:start position:0% +illustrate +this I will not do the qcd it's a little + + align:start position:0% +this I will not do the qcd it's a little + + + align:start position:0% +this I will not do the qcd it's a little +bit complicated we just do a simple + + align:start position:0% +bit complicated we just do a simple + + + align:start position:0% +bit complicated we just do a simple +scale of field Theory + + align:start position:0% +scale of field Theory + + + align:start position:0% +scale of field Theory +okay so we just do a simple scal of + + align:start position:0% +okay so we just do a simple scal of + + + align:start position:0% +okay so we just do a simple scal of +field the as a + + align:start position:0% +field the as a + + + align:start position:0% +field the as a +illustration so let's consider the + + align:start position:0% +illustration so let's consider the + + + align:start position:0% +illustration so let's consider the +following + + align:start position:0% + + + + align:start position:0% + +Theory + + align:start position:0% + + + + align:start position:0% + +okay so this G is still coupling + + align:start position:0% +okay so this G is still coupling + + + align:start position:0% +okay so this G is still coupling +constant for what we do it's actually + + align:start position:0% +constant for what we do it's actually + + + align:start position:0% +constant for what we do it's actually +convenient to put it in the + + align:start position:0% +convenient to put it in the + + + align:start position:0% +convenient to put it in the +front of course you can rescale it I'm + + align:start position:0% +front of course you can rescale it I'm + + + align:start position:0% +front of course you can rescale it I'm +sure you you can rescale it to put it + + align:start position:0% +sure you you can rescale it to put it + + + align:start position:0% +sure you you can rescale it to put it +here which is normal place but I put it + + align:start position:0% +here which is normal place but I put it + + + align:start position:0% +here which is normal place but I put it +in the front just like what we normally + + align:start position:0% +in the front just like what we normally + + + align:start position:0% +in the front just like what we normally +do also for qcd okay so this G is cing + + align:start position:0% +do also for qcd okay so this G is cing + + + align:start position:0% +do also for qcd okay so this G is cing +con which we put in the front + + align:start position:0% +con which we put in the front + + + align:start position:0% +con which we put in the front +and then each five again I take it to be + + align:start position:0% +and then each five again I take it to be + + + align:start position:0% +and then each five again I take it to be +M byn commission + + align:start position:0% +M byn commission + + + align:start position:0% +M byn commission +Matrix + + align:start position:0% +Matrix + + + align:start position:0% +Matrix +5x each one is a matrix a b so have two + + align:start position:0% +5x each one is a matrix a b so have two + + + align:start position:0% +5x each one is a matrix a b so have two +index so this m by m commission + + align:start position:0% +index so this m by m commission + + + align:start position:0% +index so this m by m commission +Matrix yeah M by Mission + + align:start position:0% + + + + align:start position:0% + +Matrix so which yeah which means that 5 + + align:start position:0% + + + + align:start position:0% + +a + + align:start position:0% + + + + align:start position:0% + +equal to + + align:start position:0% +equal to + + + align:start position:0% +equal to +Star equal to + + align:start position:0% +Star equal to + + + align:start position:0% +Star equal to +5ba + + align:start position:0% +5ba + + + align:start position:0% +5ba +okay so there's a + + align:start position:0% +okay so there's a + + + align:start position:0% +okay so there's a +um so there's a difference between the + + align:start position:0% +um so there's a difference between the + + + align:start position:0% +um so there's a difference between the +up and lower indices + + align:start position:0% + + + + align:start position:0% + +okay so I can write it more explicit in + + align:start position:0% +okay so I can write it more explicit in + + + align:start position:0% +okay so I can write it more explicit in +terms of + + align:start position:0% +terms of + + + align:start position:0% +terms of +components so just to give you in case + + align:start position:0% +components so just to give you in case + + + align:start position:0% +components so just to give you in case +some of you are not familiar with this + + align:start position:0% +some of you are not familiar with this + + + align:start position:0% +some of you are not familiar with this +kind of + + align:start position:0% +kind of + + + align:start position:0% +kind of +kind of field + + align:start position:0% +kind of field + + + align:start position:0% +kind of field +Theory so let me just also write it in + + align:start position:0% +Theory so let me just also write it in + + + align:start position:0% +Theory so let me just also write it in +terms of + + align:start position:0% + + + + align:start position:0% + +component so right in terms of + + align:start position:0% + + + + align:start position:0% + +components it's 12 partial mu by + + align:start position:0% +components it's 12 partial mu by + + + align:start position:0% +components it's 12 partial mu by +a then partial mu by + + align:start position:0% +a then partial mu by + + + align:start position:0% +a then partial mu by +ba then + + align:start position:0% +ba then + + + align:start position:0% +ba then +Plus one + + align:start position:0% +Plus one + + + align:start position:0% +Plus one +quter 5 a + + align:start position:0% +quter 5 a + + + align:start position:0% +quter 5 a +b 5 b + + align:start position:0% +b 5 b + + + align:start position:0% +b 5 b +c 5 + + align:start position:0% +c 5 + + + align:start position:0% +c 5 +CA + + align:start position:0% +CA + + + align:start position:0% +CA +five No 5 + + align:start position:0% +five No 5 + + + align:start position:0% +five No 5 +CD 5 + + align:start position:0% +CD 5 + + + align:start position:0% +CD 5 +da + + align:start position:0% +da + + + align:start position:0% +da +okay okay so this is the just having + + align:start position:0% +okay okay so this is the just having + + + align:start position:0% +okay okay so this is the just having +writing down the explicit using + + align:start position:0% + + + + align:start position:0% + +component so so this L by + + align:start position:0% +component so so this L by + + + align:start position:0% +component so so this L by +definition + + align:start position:0% +definition + + + align:start position:0% +definition +is invariant + + align:start position:0% + + + + align:start position:0% + +under in addition to the usual + + align:start position:0% +under in addition to the usual + + + align:start position:0% +under in addition to the usual +translation rotation symmetries Etc has + + align:start position:0% +translation rotation symmetries Etc has + + + align:start position:0% +translation rotation symmetries Etc has +also a um internal + + align:start position:0% +also a um internal + + + align:start position:0% +also a um internal +symmetry under un Global + + align:start position:0% + + + + align:start position:0% + +symmetry okay so uh + + align:start position:0% +symmetry okay so uh + + + align:start position:0% +symmetry okay so uh +um say 5x goes to U 5x U + + align:start position:0% +um say 5x goes to U 5x U + + + align:start position:0% +um say 5x goes to U 5x U +dagger for any + + align:start position:0% +dagger for any + + + align:start position:0% +dagger for any +U any + + align:start position:0% + + + + align:start position:0% + +constant + + align:start position:0% +constant + + + align:start position:0% +constant +is U + + align:start position:0% +is U + + + align:start position:0% +is U +Matrix + + align:start position:0% + + + + align:start position:0% + +okay so this series in warant under so + + align:start position:0% +okay so this series in warant under so + + + align:start position:0% +okay so this series in warant under so +this is obvious from here because of + + align:start position:0% +this is obvious from here because of + + + align:start position:0% +this is obvious from here because of +this + + align:start position:0% +this + + + align:start position:0% +this +Chace so this is in Waring on this + + align:start position:0% + + + + align:start position:0% + +okay so let me just make some remarks + + align:start position:0% +okay so let me just make some remarks + + + align:start position:0% +okay so let me just make some remarks +before proceed to talk about the + + align:start position:0% +before proceed to talk about the + + + align:start position:0% +before proceed to talk about the +features of this series let me just make + + align:start position:0% +features of this series let me just make + + + align:start position:0% +features of this series let me just make +some quick + + align:start position:0% + + + + align:start position:0% + +remark zero you said this is a Ser of n + + align:start position:0% +remark zero you said this is a Ser of n + + + align:start position:0% +remark zero you said this is a Ser of n +Square scalar + + align:start position:0% +Square scalar + + + align:start position:0% +Square scalar +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +field okay so if this is intuitive to + + align:start position:0% +field okay so if this is intuitive to + + + align:start position:0% +field okay so if this is intuitive to +you + + align:start position:0% +you + + + align:start position:0% +you +then this is just means you have many + + align:start position:0% +then this is just means you have many + + + align:start position:0% +then this is just means you have many +many fields coupled together in some + + align:start position:0% +many fields coupled together in some + + + align:start position:0% +many fields coupled together in some +specific way + + align:start position:0% + + + + align:start position:0% + +okay and uh also we don't have to + + align:start position:0% +okay and uh also we don't have to + + + align:start position:0% +okay and uh also we don't have to +consider her Mission matrices to + + align:start position:0% +consider her Mission matrices to + + + align:start position:0% +consider her Mission matrices to +consider her Mission Matrix just for + + align:start position:0% +consider her Mission Matrix just for + + + align:start position:0% +consider her Mission Matrix just for +Simplicity when can also + + align:start position:0% +Simplicity when can also + + + align:start position:0% +Simplicity when can also +consider can + + align:start position:0% +consider can + + + align:start position:0% +consider can +consider + + align:start position:0% +consider + + + align:start position:0% +consider +other type of + + align:start position:0% + + + + align:start position:0% + +matrices for example + + align:start position:0% + + + + align:start position:0% + +real say symmetric + + align:start position:0% +real say symmetric + + + align:start position:0% +real say symmetric +Matrix say it's real symmetric or + + align:start position:0% +Matrix say it's real symmetric or + + + align:start position:0% +Matrix say it's real symmetric or +antisymmetric + + align:start position:0% + + + + align:start position:0% + +matri so in those cases if you consider + + align:start position:0% +matri so in those cases if you consider + + + align:start position:0% +matri so in those cases if you consider +say + + align:start position:0% +say + + + align:start position:0% +say +real matri then symmetric or anti + + align:start position:0% +real matri then symmetric or anti + + + align:start position:0% +real matri then symmetric or anti +symmetric Matrix in that case this + + align:start position:0% +symmetric Matrix in that case this + + + align:start position:0% +symmetric Matrix in that case this +Global syat become s o + + align:start position:0% +Global syat become s o + + + align:start position:0% +Global syat become s o +n okay rather than unu n + + align:start position:0% + + + + align:start position:0% + +so in here this U is a global SYM just U + + align:start position:0% +so in here this U is a global SYM just U + + + align:start position:0% +so in here this U is a global SYM just U +has beant cannot depend on X you see it + + align:start position:0% +has beant cannot depend on X you see it + + + align:start position:0% +has beant cannot depend on X you see it +from here cannot depend on X but you can + + align:start position:0% + + + + align:start position:0% + +also can + + align:start position:0% + + + + align:start position:0% + +also introduce GA + + align:start position:0% + + + + align:start position:0% + +fields to make + + align:start position:0% +fields to make + + + align:start position:0% +fields to make +this un symm + + align:start position:0% + + + + align:start position:0% + +local + + align:start position:0% +local + + + align:start position:0% +local +okay so I will not do it now but this + + align:start position:0% +okay so I will not do it now but this + + + align:start position:0% +okay so I will not do it now but this +will be important a little bit later so + + align:start position:0% +will be important a little bit later so + + + align:start position:0% +will be important a little bit later so +later we will indeed make it into a + + align:start position:0% +later we will indeed make it into a + + + align:start position:0% +later we will indeed make it into a +local gaug symmetry but for now uh let + + align:start position:0% +local gaug symmetry but for now uh let + + + align:start position:0% +local gaug symmetry but for now uh let +me just consider this simple example + + align:start position:0% +me just consider this simple example + + + align:start position:0% +me just consider this simple example +okay because I don't want to introduce + + align:start position:0% +okay because I don't want to introduce + + + align:start position:0% +okay because I don't want to introduce +too many fields exactly + + align:start position:0% + + + + align:start position:0% + +so any questions regarding the setup of + + align:start position:0% +so any questions regarding the setup of + + + align:start position:0% +so any questions regarding the setup of +this + + align:start position:0% +this + + + align:start position:0% +this +the yes can you explain the last point + + align:start position:0% +the yes can you explain the last point + + + align:start position:0% +the yes can you explain the last point +so so what do you mean that if you how + + align:start position:0% +so so what do you mean that if you how + + + align:start position:0% +so so what do you mean that if you how +does introducing gauge Fields make the + + align:start position:0% +does introducing gauge Fields make the + + + align:start position:0% +does introducing gauge Fields make the +Symmetry local + + align:start position:0% +Symmetry local + + + align:start position:0% +Symmetry local +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +um yeah you have to take 832 + + align:start position:0% +um yeah you have to take 832 + + + align:start position:0% +um yeah you have to take 832 +4 to know that but the simple way to + + align:start position:0% +4 to know that but the simple way to + + + align:start position:0% +4 to know that but the simple way to +explain + + align:start position:0% +explain + + + align:start position:0% +explain +it + + align:start position:0% +it + + + align:start position:0% +it +um yeah there's no simple way to + + align:start position:0% + + + + align:start position:0% + +explain yeah yeah just say just + + align:start position:0% +explain yeah yeah just say just + + + align:start position:0% +explain yeah yeah just say just +say let me just explain the + + align:start position:0% +say let me just explain the + + + align:start position:0% +say let me just explain the +statement if you introduce some gauge + + align:start position:0% +statement if you introduce some gauge + + + align:start position:0% +statement if you introduce some gauge +field then you can make this U to be + + align:start position:0% +field then you can make this U to be + + + align:start position:0% +field then you can make this U to be +some arbitary function of X rather than + + align:start position:0% +some arbitary function of X rather than + + + align:start position:0% +some arbitary function of X rather than +a constant so that's the statement of a + + align:start position:0% +a constant so that's the statement of a + + + align:start position:0% +a constant so that's the statement of a +local yeah yeah just I can generalize + + align:start position:0% +local yeah yeah just I can generalize + + + align:start position:0% +local yeah yeah just I can generalize +this Theory so that this symmetry become + + align:start position:0% +this Theory so that this symmetry become + + + align:start position:0% +this Theory so that this symmetry become +a local ah be become a symmetry so that + + align:start position:0% +a local ah be become a symmetry so that + + + align:start position:0% +a local ah be become a symmetry so that +you can have arbitary X dependence uh + + align:start position:0% +you can have arbitary X dependence uh + + + align:start position:0% +you can have arbitary X dependence uh +can have arbitary SpaceTime dependence + + align:start position:0% +can have arbitary SpaceTime dependence + + + align:start position:0% +can have arbitary SpaceTime dependence +yeah so right now you must be a + + align:start position:0% +yeah so right now you must be a + + + align:start position:0% +yeah so right now you must be a +constant any other + + align:start position:0% + + + + align:start position:0% + +questions + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +good okay so + + align:start position:0% +good okay so + + + align:start position:0% +good okay so +now let's just try try to do peration + + align:start position:0% +now let's just try try to do peration + + + align:start position:0% +now let's just try try to do peration +Theory think g s small try to do + + align:start position:0% +Theory think g s small try to do + + + align:start position:0% +Theory think g s small try to do +peration Theory okay so the first thing + + align:start position:0% +peration Theory okay so the first thing + + + align:start position:0% +peration Theory okay so the first thing +you + + align:start position:0% +you + + + align:start position:0% +you +do of course is to write down the fan + + align:start position:0% + + + + align:start position:0% + +rules say first you have look at the + + align:start position:0% + + + + align:start position:0% + +propagator okay look at the + + align:start position:0% +propagator okay look at the + + + align:start position:0% +propagator okay look at the +propagator so you can essentially uh uh + + align:start position:0% +propagator so you can essentially uh uh + + + align:start position:0% +propagator so you can essentially uh uh +uh you are all Fields your exper so just + + align:start position:0% +uh you are all Fields your exper so just + + + align:start position:0% +uh you are all Fields your exper so just +by looking at that grounding then you + + align:start position:0% +by looking at that grounding then you + + + align:start position:0% +by looking at that grounding then you +can immediately write down this + + align:start position:0% + + + + align:start position:0% + +propagator we can just write down xus + + align:start position:0% +propagator we can just write down xus + + + align:start position:0% +propagator we can just write down xus +y okay so whatever propagator whatever + + align:start position:0% +y okay so whatever propagator whatever + + + align:start position:0% +y okay so whatever propagator whatever +space time dependence let me just call + + align:start position:0% +space time dependence let me just call + + + align:start position:0% +space time dependence let me just call +xus Y but also there's Anri index + + align:start position:0% +xus Y but also there's Anri index + + + align:start position:0% +xus Y but also there's Anri index +structure first there's also g + + align:start position:0% +structure first there's also g + + + align:start position:0% +structure first there's also g +s okay because there's a prefa one of G + + align:start position:0% +s okay because there's a prefa one of G + + + align:start position:0% +s okay because there's a prefa one of G +Square so when you invert the ktic this + + align:start position:0% +Square so when you invert the ktic this + + + align:start position:0% +Square so when you invert the ktic this +G + + align:start position:0% +G + + + align:start position:0% +G +sare and but the index structure is at + + align:start position:0% +sare and but the index structure is at + + + align:start position:0% +sare and but the index structure is at +AB b a so that a must contract with c + + align:start position:0% +AB b a so that a must contract with c + + + align:start position:0% +AB b a so that a must contract with c +and b must be the same as C so that + + align:start position:0% +and b must be the same as C so that + + + align:start position:0% +and b must be the same as C so that +means we have Delta a d and the Delta CB + + align:start position:0% +means we have Delta a d and the Delta CB + + + align:start position:0% +means we have Delta a d and the Delta CB +BC + + align:start position:0% +BC + + + align:start position:0% +BC +okay okay because in the L ground you + + align:start position:0% +okay okay because in the L ground you + + + align:start position:0% +okay okay because in the L ground you +only those field are PA so the + + align:start position:0% +only those field are PA so the + + + align:start position:0% +only those field are PA so the +propagator must have this + + align:start position:0% +propagator must have this + + + align:start position:0% +propagator must have this +structure so same we can write down + + align:start position:0% +structure so same we can write down + + + align:start position:0% +structure so same we can write down +the so there's a four particle + + align:start position:0% +the so there's a four particle + + + align:start position:0% +the so there's a four particle +interaction + + align:start position:0% + + + + align:start position:0% + +vertex so so each particle have two + + align:start position:0% +vertex so so each particle have two + + + align:start position:0% +vertex so so each particle have two +index so this is + + align:start position:0% +index so this is + + + align:start position:0% +index so this is +a + + align:start position:0% +a + + + align:start position:0% +a +CD + + align:start position:0% +CD + + + align:start position:0% +CD +EF oh yeah right sorry let me add one + + align:start position:0% +EF oh yeah right sorry let me add one + + + align:start position:0% +EF oh yeah right sorry let me add one +more and then I can Delo this + + align:start position:0% +more and then I can Delo this + + + align:start position:0% +more and then I can Delo this +diagrammatically just as AB c + + align:start position:0% +diagrammatically just as AB c + + + align:start position:0% +diagrammatically just as AB c +d okay just load this diagrammatic ially + + align:start position:0% +d okay just load this diagrammatic ially + + + align:start position:0% +d okay just load this diagrammatic ially +as the propagator which is W line ABCD + + align:start position:0% +as the propagator which is W line ABCD + + + align:start position:0% +as the propagator which is W line ABCD +okay and now also we have this Quantic + + align:start position:0% +okay and now also we have this Quantic + + + align:start position:0% +okay and now also we have this Quantic +interaction vertices which involve in + + align:start position:0% +interaction vertices which involve in + + + align:start position:0% +interaction vertices which involve in +four Fields so each field have two index + + align:start position:0% +four Fields so each field have two index + + + align:start position:0% +four Fields so each field have two index +because a so a b c d e f + + align:start position:0% + + + + align:start position:0% + +GH but this is not arital inaction they + + align:start position:0% +GH but this is not arital inaction they + + + align:start position:0% +GH but this is not arital inaction they +have contracted in the inaction + + align:start position:0% +have contracted in the inaction + + + align:start position:0% +have contracted in the inaction +contracted in the specific way so you + + align:start position:0% +contracted in the specific way so you + + + align:start position:0% +contracted in the specific way so you +get 1/ G squ because overall Factor G + + align:start position:0% +get 1/ G squ because overall Factor G + + + align:start position:0% +get 1/ G squ because overall Factor G +square and then you have do + + align:start position:0% +square and then you have do + + + align:start position:0% +square and then you have do +BC do + + align:start position:0% +BC do + + + align:start position:0% +BC do +D DOTA + + align:start position:0% +D DOTA + + + align:start position:0% +D DOTA +FG ha okay because they have to be + + align:start position:0% +FG ha okay because they have to be + + + align:start position:0% +FG ha okay because they have to be +contracted okay better to write it as AB + + align:start position:0% +contracted okay better to write it as AB + + + align:start position:0% +contracted okay better to write it as AB +this way + + align:start position:0% +this way + + + align:start position:0% +this way +AB okay so so a b contracted with c d + + align:start position:0% +AB okay so so a b contracted with c d + + + align:start position:0% +AB okay so so a b contracted with c d +contract with e e contract with g h + + align:start position:0% +contract with e e contract with g h + + + align:start position:0% +contract with e e contract with g h +contract with a so this give you a + + align:start position:0% +contract with a so this give you a + + + align:start position:0% +contract with a so this give you a +matrix product so uh just like that + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +H um + + align:start position:0% +H um + + + align:start position:0% +H um +a yeah let me just call DC that's right + + align:start position:0% + + + + align:start position:0% + +okay so this is a fman rule so now you + + align:start position:0% +okay so this is a fman rule so now you + + + align:start position:0% +okay so this is a fman rule so now you +can start + + align:start position:0% +can start + + + align:start position:0% +can start +calculating + + align:start position:0% +calculating + + + align:start position:0% +calculating +okay so if you have calculated this for + + align:start position:0% +okay so if you have calculated this for + + + align:start position:0% +okay so if you have calculated this for +a while then you find this is a little + + align:start position:0% +a while then you find this is a little + + + align:start position:0% +a while then you find this is a little +bit + + align:start position:0% +bit + + + align:start position:0% +bit +tedious with all these indices is it's + + align:start position:0% +tedious with all these indices is it's + + + align:start position:0% +tedious with all these indices is it's +quite a + + align:start position:0% +quite a + + + align:start position:0% +quite a +ling and um but to this a smart to was a + + align:start position:0% +ling and um but to this a smart to was a + + + align:start position:0% +ling and um but to this a smart to was a +smart FAL so he say let me find a way so + + align:start position:0% +smart FAL so he say let me find a way so + + + align:start position:0% +smart FAL so he say let me find a way so +that I don't have to keep track of all + + align:start position:0% +that I don't have to keep track of all + + + align:start position:0% +that I don't have to keep track of all +this indices okay then he invented the + + align:start position:0% +this indices okay then he invented the + + + align:start position:0% +this indices okay then he invented the +very nice way so this is called double + + align:start position:0% +very nice way so this is called double + + + align:start position:0% +very nice way so this is called double +line + + align:start position:0% + + + + align:start position:0% + +notation so first + + align:start position:0% +notation so first + + + align:start position:0% +notation so first +this + + align:start position:0% +this + + + align:start position:0% +this +propagator AB B C + + align:start position:0% + + + + align:start position:0% + +D since that a is contracted with c c is + + align:start position:0% +D since that a is contracted with c c is + + + align:start position:0% +D since that a is contracted with c c is +contracted with B separately he said + + align:start position:0% +contracted with B separately he said + + + align:start position:0% +contracted with B separately he said +let's just write it as a double + + align:start position:0% + + + + align:start position:0% + +line but since there's a difference + + align:start position:0% +line but since there's a difference + + + align:start position:0% +line but since there's a difference +between the upper and lower indices so + + align:start position:0% +between the upper and lower indices so + + + align:start position:0% +between the upper and lower indices so +let's define a direction for this double + + align:start position:0% +let's define a direction for this double + + + align:start position:0% +let's define a direction for this double +line so this should be go so this Define + + align:start position:0% +line so this should be go so this Define + + + align:start position:0% +line so this should be go so this Define +the direction to go from the upper index + + align:start position:0% +the direction to go from the upper index + + + align:start position:0% +the direction to go from the upper index +to the lower index then you will have a + + align:start position:0% +to the lower index then you will have a + + + align:start position:0% +to the lower index then you will have a +then you have D then CB okay because for + + align:start position:0% +then you have D then CB okay because for + + + align:start position:0% +then you have D then CB okay because for +C is upper to lower index you go from CD + + align:start position:0% + + + + align:start position:0% + +okay so now you have now you don't have + + align:start position:0% +okay so now you have now you don't have + + + align:start position:0% +okay so now you have now you don't have +to worry about this uh Contra this + + align:start position:0% +to worry about this uh Contra this + + + align:start position:0% +to worry about this uh Contra this +anymore because it's automatically taken + + align:start position:0% +anymore because it's automatically taken + + + align:start position:0% +anymore because it's automatically taken +care by this + + align:start position:0% +care by this + + + align:start position:0% +care by this +notation + + align:start position:0% + + + + align:start position:0% + +similarly this one is it's also + + align:start position:0% +similarly this one is it's also + + + align:start position:0% +similarly this one is it's also +automatically taken care + + align:start position:0% +automatically taken care + + + align:start position:0% +automatically taken care +of because each one if you replace + + align:start position:0% + + + + align:start position:0% + +it by the double line + + align:start position:0% + + + + align:start position:0% + +rotation then you just make it a b then + + align:start position:0% +rotation then you just make it a b then + + + align:start position:0% +rotation then you just make it a b then +B is equal to c b equal to here c equal + + align:start position:0% +B is equal to c b equal to here c equal + + + align:start position:0% +B is equal to c b equal to here c equal +to C D equal to D and a to + + align:start position:0% +to C D equal to D and a to + + + align:start position:0% +to C D equal to D and a to +a okay and then we have g s + + align:start position:0% +a okay and then we have g s + + + align:start position:0% +a okay and then we have g s +here you have G + + align:start position:0% +here you have G + + + align:start position:0% +here you have G +Square okay so once you draw the double + + align:start position:0% +Square okay so once you draw the double + + + align:start position:0% +Square okay so once you draw the double +line notation so let me also draw the + + align:start position:0% + + + + align:start position:0% + +arrow once you have a double annotation + + align:start position:0% +arrow once you have a double annotation + + + align:start position:0% +arrow once you have a double annotation +then all + + align:start position:0% + + + + align:start position:0% + +those the LA in delas they automatic + + align:start position:0% +those the LA in delas they automatic + + + align:start position:0% +those the LA in delas they automatic +taken care + + align:start position:0% +taken care + + + align:start position:0% +taken care +of okay + + align:start position:0% +of okay + + + align:start position:0% +of okay +on the left + + align:start position:0% + + + + align:start position:0% + +left + + align:start position:0% +left + + + align:start position:0% +left +to sorry which + + align:start position:0% + + + + align:start position:0% + +one + + align:start position:0% +one + + + align:start position:0% +one +here + + align:start position:0% +here + + + align:start position:0% +here +that if you write oh okay + + align:start position:0% +that if you write oh okay + + + align:start position:0% +that if you write oh okay +um BC that's right + + align:start position:0% + + + + align:start position:0% + +BC good good + + align:start position:0% +BC good good + + + align:start position:0% +BC good good +good so so now let us give you some + + align:start position:0% +good so so now let us give you some + + + align:start position:0% +good so so now let us give you some +examples of using this diagram to + + align:start position:0% +examples of using this diagram to + + + align:start position:0% +examples of using this diagram to +calculate + + align:start position:0% +calculate + + + align:start position:0% +calculate +things and also try to calculate the + + align:start position:0% +things and also try to calculate the + + + align:start position:0% +things and also try to calculate the +independence because eventually we want + + align:start position:0% +independence because eventually we want + + + align:start position:0% +independence because eventually we want +to take a lar limit okay so we want to + + align:start position:0% +to take a lar limit okay so we want to + + + align:start position:0% +to take a lar limit okay so we want to +keep track of the + + align:start position:0% + + + + align:start position:0% + +independence yes uh the four point + + align:start position:0% +independence yes uh the four point + + + align:start position:0% +independence yes uh the four point +coupling uh does it come from the + + align:start position:0% +coupling uh does it come from the + + + align:start position:0% +coupling uh does it come from the +commutator in the F menu and the gaug + + align:start position:0% +commutator in the F menu and the gaug + + + align:start position:0% +commutator in the F menu and the gaug +here no I just rot done by myself okay + + align:start position:0% +here no I just rot done by myself okay + + + align:start position:0% +here no I just rot done by myself okay +so it's an additional thing yeah yeah + + align:start position:0% +so it's an additional thing yeah yeah + + + align:start position:0% +so it's an additional thing yeah yeah +it's it's + + align:start position:0% +it's it's + + + align:start position:0% +it's it's +AR yeah just arbitary field the yeah + + align:start position:0% +AR yeah just arbitary field the yeah + + + align:start position:0% +AR yeah just arbitary field the yeah +just + + align:start position:0% + + + + align:start position:0% + +example okay so now let's try uh start + + align:start position:0% +example okay so now let's try uh start + + + align:start position:0% +example okay so now let's try uh start +calculating you have already have the + + align:start position:0% +calculating you have already have the + + + align:start position:0% +calculating you have already have the +for f rule what you wait + + align:start position:0% +for f rule what you wait + + + align:start position:0% +for f rule what you wait +for so let's just let's just to + + align:start position:0% +for so let's just let's just to + + + align:start position:0% +for so let's just let's just to +calculate so the first thing let's look + + align:start position:0% +calculate so the first thing let's look + + + align:start position:0% +calculate so the first thing let's look +at the vacuum + + align:start position:0% +at the vacuum + + + align:start position:0% +at the vacuum +energy okay so that's this the first + + align:start position:0% +energy okay so that's this the first + + + align:start position:0% +energy okay so that's this the first +thing to calculate so what's the vacuum + + align:start position:0% +thing to calculate so what's the vacuum + + + align:start position:0% +thing to calculate so what's the vacuum +energy the vacuum energy is all the + + align:start position:0% +energy the vacuum energy is all the + + + align:start position:0% +energy the vacuum energy is all the +diagrams it's a summation of all the + + align:start position:0% +diagrams it's a summation of all the + + + align:start position:0% +diagrams it's a summation of all the +diagram without external LS + + align:start position:0% +diagram without external LS + + + align:start position:0% +diagram without external LS +okay + + align:start position:0% +okay + + + align:start position:0% +okay +um yeah let's just so so the so the + + align:start position:0% +um yeah let's just so so the so the + + + align:start position:0% +um yeah let's just so so the so the +simplest + + align:start position:0% +simplest + + + align:start position:0% +simplest +diagram is just the the uh uh the with + + align:start position:0% +diagram is just the the uh uh the with + + + align:start position:0% +diagram is just the the uh uh the with +one + + align:start position:0% + + + + align:start position:0% + +vertex + + align:start position:0% + + + + align:start position:0% + +okay so this is a simplest + + align:start position:0% + + + + align:start position:0% + +diagram but + + align:start position:0% +diagram but + + + align:start position:0% +diagram but +now so if you do Lambda 54 series then + + align:start position:0% +now so if you do Lambda 54 series then + + + align:start position:0% +now so if you do Lambda 54 series then +that will be the end of the + + align:start position:0% +that will be the end of the + + + align:start position:0% +that will be the end of the +story + + align:start position:0% +story + + + align:start position:0% +story +okay you just contract of them but + + align:start position:0% +okay you just contract of them but + + + align:start position:0% +okay you just contract of them but +now the Matrix because we are + + align:start position:0% +now the Matrix because we are + + + align:start position:0% +now the Matrix because we are +Contracting + + align:start position:0% +Contracting + + + align:start position:0% +Contracting +matrices okay so this is like + + align:start position:0% +matrices okay so this is like + + + align:start position:0% +matrices okay so this is like +contracting two four matrices when you + + align:start position:0% +contracting two four matrices when you + + + align:start position:0% +contracting two four matrices when you +trting matrices but matrices don't + + align:start position:0% +trting matrices but matrices don't + + + align:start position:0% +trting matrices but matrices don't +commute so actually there's a + + align:start position:0% +commute so actually there's a + + + align:start position:0% +commute so actually there's a +difference so you you should convince + + align:start position:0% + + + + align:start position:0% + +yourself there's a difference which I + + align:start position:0% +yourself there's a difference which I + + + align:start position:0% +yourself there's a difference which I +actually connect this two this two + + align:start position:0% +actually connect this two this two + + + align:start position:0% +actually connect this two this two +from which I connect this two and this + + align:start position:0% +from which I connect this two and this + + + align:start position:0% +from which I connect this two and this +two + + align:start position:0% +two + + + align:start position:0% +two +okay because this this corresponding I + + align:start position:0% +okay because this this corresponding I + + + align:start position:0% +okay because this this corresponding I +connect the labeling ones and this one I + + align:start position:0% +connect the labeling ones and this one I + + + align:start position:0% +connect the labeling ones and this one I +connect the diagonal ones and the order + + align:start position:0% +connect the diagonal ones and the order + + + align:start position:0% +connect the diagonal ones and the order +actually matters okay the order actually + + align:start position:0% +actually matters okay the order actually + + + align:start position:0% +actually matters okay the order actually +matters because Matrix is don't + + align:start position:0% +matters because Matrix is don't + + + align:start position:0% +matters because Matrix is don't +commute so if I call this + + align:start position:0% +commute so if I call this + + + align:start position:0% +commute so if I call this +a and + + align:start position:0% +a and + + + align:start position:0% +a and +b and a not equal to + + align:start position:0% +b and a not equal to + + + align:start position:0% +b and a not equal to +B because the matrices don't commute + + align:start position:0% +B because the matrices don't commute + + + align:start position:0% +B because the matrices don't commute +okay so now let's do the end + + align:start position:0% +okay so now let's do the end + + + align:start position:0% +okay so now let's do the end +Counting + + align:start position:0% +Counting + + + align:start position:0% +Counting +so do the end counting is actually much + + align:start position:0% +so do the end counting is actually much + + + align:start position:0% +so do the end counting is actually much +simpler we use this double line notation + + align:start position:0% +simpler we use this double line notation + + + align:start position:0% +simpler we use this double line notation +so let's now use the double line + + align:start position:0% +so let's now use the double line + + + align:start position:0% +so let's now use the double line +notation because all this n so when you + + align:start position:0% +notation because all this n so when you + + + align:start position:0% +notation because all this n so when you +do the + + align:start position:0% +do the + + + align:start position:0% +do the +contractions you have all these + + align:start position:0% +contractions you have all these + + + align:start position:0% +contractions you have all these +indices you sum of all those indices + + align:start position:0% +indices you sum of all those indices + + + align:start position:0% +indices you sum of all those indices +when you sum all those indes you get + + align:start position:0% +when you sum all those indes you get + + + align:start position:0% +when you sum all those indes you get +some factors of n so that's how n will + + align:start position:0% +some factors of n so that's how n will + + + align:start position:0% +some factors of n so that's how n will +come will come into this + + align:start position:0% +come will come into this + + + align:start position:0% +come will come into this +the and uh but the but double notation + + align:start position:0% +the and uh but the but double notation + + + align:start position:0% +the and uh but the but double notation +makes makes the constraint all manifest + + align:start position:0% +makes makes the constraint all manifest + + + align:start position:0% +makes makes the constraint all manifest +so the contraction will be automatic you + + align:start position:0% +so the contraction will be automatic you + + + align:start position:0% +so the contraction will be automatic you +don't have to worry about all those + + align:start position:0% +don't have to worry about all those + + + align:start position:0% +don't have to worry about all those +delas so so let's just do that let's + + align:start position:0% +delas so so let's just do that let's + + + align:start position:0% +delas so so let's just do that let's +draw this four point + + align:start position:0% + + + + align:start position:0% + +vertex for this one we just Contracting + + align:start position:0% +vertex for this one we just Contracting + + + align:start position:0% +vertex for this one we just Contracting +laboring + + align:start position:0% + + + + align:start position:0% + +ones for this one we do the same + + align:start position:0% + + + + align:start position:0% + +thing we + + align:start position:0% +thing we + + + align:start position:0% +thing we +contract nor bring + + align:start position:0% + + + + align:start position:0% + +once yeah I did not draw very + + align:start position:0% + + + + align:start position:0% + +well + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +okay so so this one should be contracted + + align:start position:0% +okay so so this one should be contracted + + + align:start position:0% +okay so so this one should be contracted +with this + + align:start position:0% +with this + + + align:start position:0% +with this +one this one should be contracted with + + align:start position:0% +one this one should be contracted with + + + align:start position:0% +one this one should be contracted with +that + + align:start position:0% +that + + + align:start position:0% +that +one + + align:start position:0% +one + + + align:start position:0% +one +and this one contract with this one this + + align:start position:0% +and this one contract with this one this + + + align:start position:0% +and this one contract with this one this +one is contract with that okay this some + + align:start position:0% +one is contract with that okay this some + + + align:start position:0% +one is contract with that okay this some +intersection so now let's come to the + + align:start position:0% + + + + align:start position:0% + +end okay so now here is the + + align:start position:0% + + + + align:start position:0% + +key each + + align:start position:0% +key each + + + align:start position:0% +key each +noop corresponding to a contracted + + align:start position:0% +noop corresponding to a contracted + + + align:start position:0% +noop corresponding to a contracted +indices okay so for example in here this + + align:start position:0% +indices okay so for example in here this + + + align:start position:0% +indices okay so for example in here this +is already a and a and then if you + + align:start position:0% +is already a and a and then if you + + + align:start position:0% +is already a and a and then if you +contract this two then you sum over this + + align:start position:0% +contract this two then you sum over this + + + align:start position:0% +contract this two then you sum over this +a when you calculate the propagator and + + align:start position:0% +a when you calculate the propagator and + + + align:start position:0% +a when you calculate the propagator and +then that give you a fact of n so each + + align:start position:0% +then that give you a fact of n so each + + + align:start position:0% +then that give you a fact of n so each +contract each closed loop essentially + + align:start position:0% +contract each closed loop essentially + + + align:start position:0% +contract each closed loop essentially +give you a factor of n okay it's just + + align:start position:0% +give you a factor of n okay it's just + + + align:start position:0% +give you a factor of n okay it's just +because you contract yeah so there's + + align:start position:0% +because you contract yeah so there's + + + align:start position:0% +because you contract yeah so there's +three Loops here three contracted Loops + + align:start position:0% +three Loops here three contracted Loops + + + align:start position:0% +three Loops here three contracted Loops +so this give you + + align:start position:0% +so this give you + + + align:start position:0% +so this give you +NQ + + align:start position:0% +NQ + + + align:start position:0% +NQ +okay and if you look at the G Square + + align:start position:0% +okay and if you look at the G Square + + + align:start position:0% +okay and if you look at the G Square +dependence so you have two propagators + + align:start position:0% +dependence so you have two propagators + + + align:start position:0% +dependence so you have two propagators +here two pro you have two propagators + + align:start position:0% +here two pro you have two propagators + + + align:start position:0% +here two pro you have two propagators +each propagator give you a g Square then + + align:start position:0% +each propagator give you a g Square then + + + align:start position:0% +each propagator give you a g Square then +you have one vertex each vertex give you + + align:start position:0% +you have one vertex each vertex give you + + + align:start position:0% +you have one vertex each vertex give you +a one of G Square so you have G + + align:start position:0% +a one of G Square so you have G + + + align:start position:0% +a one of G Square so you have G +squ + + align:start position:0% +squ + + + align:start position:0% +squ +okay so now let's look at this + + align:start position:0% +okay so now let's look at this + + + align:start position:0% +okay so now let's look at this +one this one let's just follow this line + + align:start position:0% +one this one let's just follow this line + + + align:start position:0% +one this one let's just follow this line +you should also draw the arrow because + + align:start position:0% +you should also draw the arrow because + + + align:start position:0% +you should also draw the arrow because +the arrow should + + align:start position:0% +the arrow should + + + align:start position:0% +the arrow should +follow okay I did not dra the arrow but + + align:start position:0% +follow okay I did not dra the arrow but + + + align:start position:0% +follow okay I did not dra the arrow but +uh but Arrow should all follow + + align:start position:0% + + + + align:start position:0% + +follow okay the arrow should be + + align:start position:0% +follow okay the arrow should be + + + align:start position:0% +follow okay the arrow should be +consistent similarly here so here if you + + align:start position:0% +consistent similarly here so here if you + + + align:start position:0% +consistent similarly here so here if you +go around you find there's only a single + + align:start position:0% +go around you find there's only a single + + + align:start position:0% +go around you find there's only a single +contracted N9 so this only a fact of n + + align:start position:0% +contracted N9 so this only a fact of n + + + align:start position:0% +contracted N9 so this only a fact of n +of course G square dependenc is the same + + align:start position:0% +of course G square dependenc is the same + + + align:start position:0% +of course G square dependenc is the same +so you have G + + align:start position:0% +so you have G + + + align:start position:0% +so you have G +Square okay so now you already see the + + align:start position:0% +Square okay so now you already see the + + + align:start position:0% +Square okay so now you already see the +difference between these two diagrams + + align:start position:0% +difference between these two diagrams + + + align:start position:0% +difference between these two diagrams +and uh um why is proportional to n one + + align:start position:0% +and uh um why is proportional to n one + + + align:start position:0% +and uh um why is proportional to n one +is propor to n + + align:start position:0% + + + + align:start position:0% + +Cube + + align:start position:0% +Cube + + + align:start position:0% +Cube +so so + + align:start position:0% +so so + + + align:start position:0% +so so +a diagram + + align:start position:0% +a diagram + + + align:start position:0% +a diagram +a can be + + align:start position:0% +a can be + + + align:start position:0% +a can be +drawn on the plane we are joining it on + + align:start position:0% +drawn on the plane we are joining it on + + + align:start position:0% +drawn on the plane we are joining it on +the + + align:start position:0% +the + + + align:start position:0% +the +plane without + + align:start position:0% + + + + align:start position:0% + +crossing without course + + align:start position:0% +crossing without course + + + align:start position:0% +crossing without course +9 so we call it a planner + + align:start position:0% + + + + align:start position:0% + +diagram and B cannot + + align:start position:0% +diagram and B cannot + + + align:start position:0% +diagram and B cannot +be draw on the plane without causing + + align:start position:0% +be draw on the plane without causing + + + align:start position:0% +be draw on the plane without causing +nines so we call L plan + + align:start position:0% + + + + align:start position:0% + +diagram + + align:start position:0% +diagram + + + align:start position:0% +diagram +okay so so let's do do one more step so + + align:start position:0% +okay so so let's do do one more step so + + + align:start position:0% +okay so so let's do do one more step so +let's do one more + + align:start position:0% + + + + align:start position:0% + +diagram so let's do one more + + align:start position:0% + + + + align:start position:0% + +diagram + + align:start position:0% +diagram + + + align:start position:0% +diagram +okay so select + + align:start position:0% + + + + align:start position:0% + +order you just get two next all the + + align:start position:0% +order you just get two next all the + + + align:start position:0% +order you just get two next all the +vacum without any external L you have + + align:start position:0% +vacum without any external L you have + + + align:start position:0% +vacum without any external L you have +two + + align:start position:0% +two + + + align:start position:0% +two +vertices okay so you can connect this + + align:start position:0% + + + + align:start position:0% + +way okay so this is one diagram you can + + align:start position:0% +way okay so this is one diagram you can + + + align:start position:0% +way okay so this is one diagram you can +also have plan L plan + + align:start position:0% +also have plan L plan + + + align:start position:0% +also have plan L plan +diagram yeah let me just draw the + + align:start position:0% +diagram yeah let me just draw the + + + align:start position:0% +diagram yeah let me just draw the +straight line rather than wavy line just + + align:start position:0% +straight line rather than wavy line just + + + align:start position:0% +straight line rather than wavy line just +to save + + align:start position:0% +to save + + + align:start position:0% +to save +trouble you can for example you can draw + + align:start position:0% +trouble you can for example you can draw + + + align:start position:0% +trouble you can for example you can draw +like this so This Is A L plan diagram + + align:start position:0% + + + + align:start position:0% + +okay so now give you a + + align:start position:0% +okay so now give you a + + + align:start position:0% +okay so now give you a +exercise today when you go home turn + + align:start position:0% +exercise today when you go home turn + + + align:start position:0% +exercise today when you go home turn +turn those into a plan uh into a double + + align:start position:0% +turn those into a plan uh into a double + + + align:start position:0% +turn those into a plan uh into a double +line uh diagrams then you should find + + align:start position:0% +line uh diagrams then you should find + + + align:start position:0% +line uh diagrams then you should find +yourself that this is n to the power 4 + + align:start position:0% +yourself that this is n to the power 4 + + + align:start position:0% +yourself that this is n to the power 4 +yeah maybe I should do this + + align:start position:0% + + + + align:start position:0% + +um um yeah let me do this one for you so + + align:start position:0% +um um yeah let me do this one for you so + + + align:start position:0% +um um yeah let me do this one for you so +let me just do this one quickly for you + + align:start position:0% + + + + align:start position:0% + +but that will allow to draw the arrows + + align:start position:0% +but that will allow to draw the arrows + + + align:start position:0% +but that will allow to draw the arrows +just to save + + align:start position:0% + + + + align:start position:0% + +time + + align:start position:0% +time + + + align:start position:0% +time +okay so this + + align:start position:0% +okay so this + + + align:start position:0% +okay so this +one you count how many contracted nines + + align:start position:0% +one you count how many contracted nines + + + align:start position:0% +one you count how many contracted nines +one 2 3 four so this give you an Force + + align:start position:0% +one 2 3 four so this give you an Force + + + align:start position:0% +one 2 3 four so this give you an Force +behavior and this I will not do it now + + align:start position:0% +behavior and this I will not do it now + + + align:start position:0% +behavior and this I will not do it now +you do it yourself so also if you count + + align:start position:0% +you do it yourself so also if you count + + + align:start position:0% +you do it yourself so also if you count +the G dependence this give you g to the + + align:start position:0% +the G dependence this give you g to the + + + align:start position:0% +the G dependence this give you g to the +power + + align:start position:0% +power + + + align:start position:0% +power +4 and this give you n + + align:start position:0% +4 and this give you n + + + align:start position:0% +4 and this give you n +sare g s or G to the power + + align:start position:0% +sare g s or G to the power + + + align:start position:0% +sare g s or G to the power +4 is it g to the power 4 maybe I'm + + align:start position:0% +4 is it g to the power 4 maybe I'm + + + align:start position:0% +4 is it g to the power 4 maybe I'm +counting wrong 1 2 3 4 four propagators + + align:start position:0% +counting wrong 1 2 3 4 four propagators + + + align:start position:0% +counting wrong 1 2 3 4 four propagators +is g s yeah g to the^ 4 + + align:start position:0% +is g s yeah g to the^ 4 + + + align:start position:0% +is g s yeah g to the^ 4 +yeah yes so in general the more is like + + align:start position:0% +yeah yes so in general the more is like + + + align:start position:0% +yeah yes so in general the more is like +the more like Crossings with that + + align:start position:0% +the more like Crossings with that + + + align:start position:0% +the more like Crossings with that +decrease and yeah that's + + align:start position:0% +decrease and yeah that's + + + align:start position:0% +decrease and yeah that's +right okay so now you can just + + align:start position:0% +right okay so now you can just + + + align:start position:0% +right okay so now you can just +continue with three vertices with four + + align:start position:0% +continue with three vertices with four + + + align:start position:0% +continue with three vertices with four +vertices + + align:start position:0% +vertices + + + align:start position:0% +vertices +Etc but of course the smart fellows will + + align:start position:0% +Etc but of course the smart fellows will + + + align:start position:0% +Etc but of course the smart fellows will +not stop and they ask H can I find some + + align:start position:0% +not stop and they ask H can I find some + + + align:start position:0% +not stop and they ask H can I find some +rules in doing this + + align:start position:0% +rules in doing this + + + align:start position:0% +rules in doing this +say how do you get the general en + + align:start position:0% +say how do you get the general en + + + align:start position:0% +say how do you get the general en +counting and whether does the all long + + align:start position:0% +counting and whether does the all long + + + align:start position:0% +counting and whether does the all long +plan the diagram will the same or or one + + align:start position:0% +plan the diagram will the same or or one + + + align:start position:0% +plan the diagram will the same or or one +need to classify them further okay so + + align:start position:0% +need to classify them further okay so + + + align:start position:0% +need to classify them further okay so +these are the obvious questions so let + + align:start position:0% +these are the obvious questions so let + + + align:start position:0% +these are the obvious questions so let +me just tell you some observations then + + align:start position:0% +me just tell you some observations then + + + align:start position:0% +me just tell you some observations then +I will close for + + align:start position:0% +I will close for + + + align:start position:0% +I will close for +today then I will close for + + align:start position:0% + + + + align:start position:0% + +today so the first observation + + align:start position:0% + + + + align:start position:0% + +so just from those examples let me just + + align:start position:0% +so just from those examples let me just + + + align:start position:0% +so just from those examples let me just +draw some + + align:start position:0% + + + + align:start position:0% + +observations observation + + align:start position:0% + + + + align:start position:0% + +one so this one requires a little bit + + align:start position:0% +one so this one requires a little bit + + + align:start position:0% +one so this one requires a little bit +Inu + + align:start position:0% + + + + align:start position:0% + +Ingenuity is said even A and + + align:start position:0% +Ingenuity is said even A and + + + align:start position:0% +Ingenuity is said even A and +B so this A and B they cannot be drawn + + align:start position:0% +B so this A and B they cannot be drawn + + + align:start position:0% +B so this A and B they cannot be drawn +on the + + align:start position:0% +on the + + + align:start position:0% +on the +plane they cannot be they cannot be + + align:start position:0% +plane they cannot be they cannot be + + + align:start position:0% +plane they cannot be they cannot be +drawn on the plane without Crossing + + align:start position:0% +drawn on the plane without Crossing + + + align:start position:0% +drawn on the plane without Crossing +Lines But A and + + align:start position:0% + + + + align:start position:0% + +B can be + + align:start position:0% +B can be + + + align:start position:0% +B can be +drawn on the + + align:start position:0% + + + + align:start position:0% + +Taurus without Crossing + + align:start position:0% + + + + align:start position:0% + +Lines + + align:start position:0% +Lines + + + align:start position:0% +Lines +okay so so now let me show it to + + align:start position:0% +okay so so now let me show it to + + + align:start position:0% +okay so so now let me show it to +you so so what is a + + align:start position:0% +you so so what is a + + + align:start position:0% +you so so what is a +Taurus so we can draw a taus on the + + align:start position:0% +Taurus so we can draw a taus on the + + + align:start position:0% +Taurus so we can draw a taus on the +plane like follows so we draw a square + + align:start position:0% +plane like follows so we draw a square + + + align:start position:0% +plane like follows so we draw a square +then we identify this side with that + + align:start position:0% +then we identify this side with that + + + align:start position:0% +then we identify this side with that +side identify this side with that side + + align:start position:0% +side identify this side with that side + + + align:start position:0% +side identify this side with that side +then then this give us a Taurus okay so + + align:start position:0% +then then this give us a Taurus okay so + + + align:start position:0% +then then this give us a Taurus okay so +because when you do that then give you a + + align:start position:0% +because when you do that then give you a + + + align:start position:0% +because when you do that then give you a +cylinder and then you do that again then + + align:start position:0% +cylinder and then you do that again then + + + align:start position:0% +cylinder and then you do that again then +give you a taus okay so but on the plane + + align:start position:0% +give you a taus okay so but on the plane + + + align:start position:0% +give you a taus okay so but on the plane +just simple + + align:start position:0% +just simple + + + align:start position:0% +just simple +identification so let's try to see this + + align:start position:0% +identification so let's try to see this + + + align:start position:0% +identification so let's try to see this +diagram now let me show this diagram can + + align:start position:0% +diagram now let me show this diagram can + + + align:start position:0% +diagram now let me show this diagram can +be draw on the turos without + + align:start position:0% +be draw on the turos without + + + align:start position:0% +be draw on the turos without +Crossing because the Vex is like + + align:start position:0% + + + + align:start position:0% + +this we want to contract this guy with + + align:start position:0% +this we want to contract this guy with + + + align:start position:0% +this we want to contract this guy with +that guy and that guy with that guy + + align:start position:0% +that guy and that guy with that guy + + + align:start position:0% +that guy and that guy with that guy +right nonlabeling ones but now I can + + align:start position:0% +right nonlabeling ones but now I can + + + align:start position:0% +right nonlabeling ones but now I can +just go + + align:start position:0% +just go + + + align:start position:0% +just go +up and now this is identified with here + + align:start position:0% +up and now this is identified with here + + + align:start position:0% +up and now this is identified with here +that can come back here can go here come + + align:start position:0% +that can come back here can go here come + + + align:start position:0% +that can come back here can go here come +back here okay so this is contracted and + + align:start position:0% +back here okay so this is contracted and + + + align:start position:0% +back here okay so this is contracted and +I don't have to cross + + align:start position:0% +I don't have to cross + + + align:start position:0% +I don't have to cross +lines + + align:start position:0% +lines + + + align:start position:0% +lines +yes good similarly let me do that + + align:start position:0% +yes good similarly let me do that + + + align:start position:0% +yes good similarly let me do that +one yeah that why maybe I will let you + + align:start position:0% +one yeah that why maybe I will let you + + + align:start position:0% +one yeah that why maybe I will let you +to do it yourself yeah do the so this is + + align:start position:0% +to do it yourself yeah do the so this is + + + align:start position:0% +to do it yourself yeah do the so this is +a this is oh no this is not a and b this + + align:start position:0% +a this is oh no this is not a and b this + + + align:start position:0% +a this is oh no this is not a and b this +is B and D let me call this B this this + + align:start position:0% +is B and D let me call this B this this + + + align:start position:0% +is B and D let me call this B this this +is let me call sorry let me call C and D + + align:start position:0% +is let me call sorry let me call C and D + + + align:start position:0% +is let me call sorry let me call C and D +so A and C are Planet + + align:start position:0% +so A and C are Planet + + + align:start position:0% +so A and C are Planet +diagrams and B and D are long plan + + align:start position:0% +diagrams and B and D are long plan + + + align:start position:0% +diagrams and B and D are long plan +diagrams + + align:start position:0% +diagrams + + + align:start position:0% +diagrams +okay so this is + + align:start position:0% +okay so this is + + + align:start position:0% +okay so this is +p so try to do yourself the + + align:start position:0% +p so try to do yourself the + + + align:start position:0% +p so try to do yourself the +D so essentially you have two + + align:start position:0% + + + + align:start position:0% + +vertex how to make that n planner + + align:start position:0% +vertex how to make that n planner + + + align:start position:0% +vertex how to make that n planner +diagram to be Planner on + + align:start position:0% +diagram to be Planner on + + + align:start position:0% +diagram to be Planner on +the on this taus when you identify here + + align:start position:0% +the on this taus when you identify here + + + align:start position:0% +the on this taus when you identify here +with there there is there okay so this + + align:start position:0% +with there there is there okay so this + + + align:start position:0% +with there there is there okay so this +is observation + + align:start position:0% + + + + align:start position:0% + +one actually let me just do it for + + align:start position:0% +one actually let me just do it for + + + align:start position:0% +one actually let me just do it for +you so so we connect because I + + align:start position:0% +you so so we connect because I + + + align:start position:0% +you so so we connect because I +didn't because I it's better I have this + + align:start position:0% +didn't because I it's better I have this + + + align:start position:0% +didn't because I it's better I have this +example to make my second + + align:start position:0% +example to make my second + + + align:start position:0% +example to make my second +point so so now I need to connect this + + align:start position:0% +point so so now I need to connect this + + + align:start position:0% +point so so now I need to connect this +to that guy but I can do it by going + + align:start position:0% + + + + align:start position:0% + +up I can this guy I can go here and then + + align:start position:0% +up I can this guy I can go here and then + + + align:start position:0% +up I can this guy I can go here and then +can go there similar in okay and then + + align:start position:0% +can go there similar in okay and then + + + align:start position:0% +can go there similar in okay and then +this is I can connect them without + + align:start position:0% +this is I can connect them without + + + align:start position:0% +this is I can connect them without +Crossing Lines so this is the + + align:start position:0% +Crossing Lines so this is the + + + align:start position:0% +Crossing Lines so this is the +observation + + align:start position:0% +observation + + + align:start position:0% +observation +one so now the observation + + align:start position:0% +one so now the observation + + + align:start position:0% +one so now the observation +two again is a little bit + + align:start position:0% +two again is a little bit + + + align:start position:0% +two again is a little bit +ingenious but maybe the slightly + + align:start position:0% +ingenious but maybe the slightly + + + align:start position:0% +ingenious but maybe the slightly +easier if you have done it long + + align:start position:0% + + + + align:start position:0% + +enough for all the a to d the following + + align:start position:0% +enough for all the a to d the following + + + align:start position:0% +enough for all the a to d the following +rule is + + align:start position:0% +rule is + + + align:start position:0% +rule is +two the + + align:start position:0% + + + + align:start position:0% + +power of + + align:start position:0% +power of + + + align:start position:0% +power of +n is equal + + align:start position:0% +n is equal + + + align:start position:0% +n is equal +to number of faces so so so this one we + + align:start position:0% +to number of faces so so so this one we + + + align:start position:0% +to number of faces so so so this one we +call so even though there cannot be + + align:start position:0% +call so even though there cannot be + + + align:start position:0% +call so even though there cannot be +cross the the cross lines on the plane + + align:start position:0% +cross the the cross lines on the plane + + + align:start position:0% +cross the the cross lines on the plane +but we can actually straighten them out + + align:start position:0% +but we can actually straighten them out + + + align:start position:0% +but we can actually straighten them out +on the Taurus okay so here we call we + + align:start position:0% +on the Taurus okay so here we call we + + + align:start position:0% +on the Taurus okay so here we call we +can straighten them out on the Taurus so + + align:start position:0% +can straighten them out on the Taurus so + + + align:start position:0% +can straighten them out on the Taurus so +so the second observ is the power N is a + + align:start position:0% +so the second observ is the power N is a + + + align:start position:0% +so the second observ is the power N is a +number of + + align:start position:0% +number of + + + align:start position:0% +number of +faces in each + + align:start position:0% + + + + align:start position:0% + +diagram + + align:start position:0% +diagram + + + align:start position:0% +diagram +after we stressing it + + align:start position:0% + + + + align:start position:0% + +out okay first let's look at this + + align:start position:0% +out okay first let's look at this + + + align:start position:0% +out okay first let's look at this +diagram this is a planet diagram so + + align:start position:0% +diagram this is a planet diagram so + + + align:start position:0% +diagram this is a planet diagram so +there's one phas + + align:start position:0% +there's one phas + + + align:start position:0% +there's one phas +there's two face and then there's a face + + align:start position:0% +there's two face and then there's a face + + + align:start position:0% +there's two face and then there's a face +outside because this a whole plane so + + align:start position:0% +outside because this a whole plane so + + + align:start position:0% +outside because this a whole plane so +there's three faces so this is n + + align:start position:0% +there's three faces so this is n + + + align:start position:0% +there's three faces so this is n +Cube and the + + align:start position:0% +Cube and the + + + align:start position:0% +Cube and the +B on the + + align:start position:0% +B on the + + + align:start position:0% +B on the +Taurus there's only one face because + + align:start position:0% +Taurus there's only one face because + + + align:start position:0% +Taurus there's only one face because +each region is connected to each other + + align:start position:0% +each region is connected to each other + + + align:start position:0% +each region is connected to each other +okay so there's only one face you see + + align:start position:0% +okay so there's only one face you see + + + align:start position:0% +okay so there's only one face you see +the power + + align:start position:0% +the power + + + align:start position:0% +the power +n so now in C you have one phas you have + + align:start position:0% +n so now in C you have one phas you have + + + align:start position:0% +n so now in C you have one phas you have +two phas you have three phas you have + + align:start position:0% +two phas you have three phas you have + + + align:start position:0% +two phas you have three phas you have +four phas okay so this is n to the^ + + align:start position:0% +four phas okay so this is n to the^ + + + align:start position:0% +four phas okay so this is n to the^ +4 and for this + + align:start position:0% +4 and for this + + + align:start position:0% +4 and for this +one you have one pH corresponding to + + align:start position:0% +one you have one pH corresponding to + + + align:start position:0% +one you have one pH corresponding to +here and then you easily convince + + align:start position:0% +here and then you easily convince + + + align:start position:0% +here and then you easily convince +yourself everything outside everything + + align:start position:0% +yourself everything outside everything + + + align:start position:0% +yourself everything outside everything +outside this region they're connected + + align:start position:0% +outside this region they're connected + + + align:start position:0% +outside this region they're connected +through the identification so you so you + + align:start position:0% +through the identification so you so you + + + align:start position:0% +through the identification so you so you +get n + + align:start position:0% +get n + + + align:start position:0% +get n +Square okay you get n + + align:start position:0% +Square okay you get n + + + align:start position:0% +Square okay you get n +Square so so these two observations so + + align:start position:0% +Square so so these two observations so + + + align:start position:0% +Square so so these two observations so +so let me stop here and then then from + + align:start position:0% +so let me stop here and then then from + + + align:start position:0% +so let me stop here and then then from +here you can figure out the general + + align:start position:0% +here you can figure out the general + + + align:start position:0% +here you can figure out the general +rules for for uh uh for yeah for + + align:start position:0% + + + + align:start position:0% + +everything \ No newline at end of file diff --git a/2XraaWefBd8.txt b/2XraaWefBd8.txt new file mode 100644 index 0000000000000000000000000000000000000000..6c83e7c4b7c07073799ac7718fc11ce510a4100f --- /dev/null +++ b/2XraaWefBd8.txt @@ -0,0 +1,7315 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +to view additional materials from + + align:start position:0% +to view additional materials from + + + align:start position:0% +to view additional materials from +hundreds of MIT courses visit MIT open + + align:start position:0% +hundreds of MIT courses visit MIT open + + + align:start position:0% +hundreds of MIT courses visit MIT open +courseware at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu okay so remember last + + align:start position:0% +ocw.mit.edu okay so remember last + + + align:start position:0% +ocw.mit.edu okay so remember last +time on Tuesday we learned about the + + align:start position:0% +time on Tuesday we learned about the + + + align:start position:0% +time on Tuesday we learned about the +chain hole + + align:start position:0% + + + + align:start position:0% + +and so for example we saw that if we + + align:start position:0% +and so for example we saw that if we + + + align:start position:0% +and so for example we saw that if we +have a + + align:start position:0% + + + + align:start position:0% + +function that + + align:start position:0% +function that + + + align:start position:0% +function that +depends sorry on three variables XY Z + + align:start position:0% +depends sorry on three variables XY Z + + + align:start position:0% +depends sorry on three variables XY Z +but XYZ themselves depends depend on + + align:start position:0% +but XYZ themselves depends depend on + + + align:start position:0% +but XYZ themselves depends depend on +some variable + + align:start position:0% + + + + align:start position:0% + +T then you can find a formula for DW DT + + align:start position:0% +T then you can find a formula for DW DT + + + align:start position:0% +T then you can find a formula for DW DT +by writing down w subx DX + + align:start position:0% +by writing down w subx DX + + + align:start position:0% +by writing down w subx DX +DT plus W suby Dy + + align:start position:0% +DT plus W suby Dy + + + align:start position:0% +DT plus W suby Dy +DT plus W subz DZ DT and the meaning of + + align:start position:0% +DT plus W subz DZ DT and the meaning of + + + align:start position:0% +DT plus W subz DZ DT and the meaning of +that + + align:start position:0% +that + + + align:start position:0% +that +formula is that well the change in W is + + align:start position:0% +formula is that well the change in W is + + + align:start position:0% +formula is that well the change in W is +caused by changes in X Y and Z x y and z + + align:start position:0% +caused by changes in X Y and Z x y and z + + + align:start position:0% +caused by changes in X Y and Z x y and z +change at rates dxdt dydt dzdt and this + + align:start position:0% +change at rates dxdt dydt dzdt and this + + + align:start position:0% +change at rates dxdt dydt dzdt and this +causes the function to change + + align:start position:0% +causes the function to change + + + align:start position:0% +causes the function to change +accordingly using the in terms of the + + align:start position:0% +accordingly using the in terms of the + + + align:start position:0% +accordingly using the in terms of the +partial well the partial derivatives + + align:start position:0% +partial well the partial derivatives + + + align:start position:0% +partial well the partial derivatives +tell you how sensitive W is to changes + + align:start position:0% +tell you how sensitive W is to changes + + + align:start position:0% +tell you how sensitive W is to changes +in each + + align:start position:0% +in each + + + align:start position:0% +in each +variable okay so we're going to just + + align:start position:0% +variable okay so we're going to just + + + align:start position:0% +variable okay so we're going to just +revite this in a new + + align:start position:0% + + + + align:start position:0% + +notation so I'm going to revite this in + + align:start position:0% +notation so I'm going to revite this in + + + align:start position:0% +notation so I'm going to revite this in +a more concise form + + align:start position:0% +a more concise form + + + align:start position:0% +a more concise form +as gradient of w product with the + + align:start position:0% +as gradient of w product with the + + + align:start position:0% +as gradient of w product with the +velocity Vector + + align:start position:0% +velocity Vector + + + align:start position:0% +velocity Vector +drdt + + align:start position:0% +drdt + + + align:start position:0% +drdt +where so the gradient of w is a vector + + align:start position:0% +where so the gradient of w is a vector + + + align:start position:0% +where so the gradient of w is a vector +formed by putting together all of the + + align:start position:0% +formed by putting together all of the + + + align:start position:0% +formed by putting together all of the +partial + + align:start position:0% +partial + + + align:start position:0% +partial +derivatives okay so it's the vector + + align:start position:0% +derivatives okay so it's the vector + + + align:start position:0% +derivatives okay so it's the vector +whose components are the partials and of + + align:start position:0% +whose components are the partials and of + + + align:start position:0% +whose components are the partials and of +course it's a vector that depends on X Y + + align:start position:0% +course it's a vector that depends on X Y + + + align:start position:0% +course it's a vector that depends on X Y +and Z right these guys depend on XYZ so + + align:start position:0% +and Z right these guys depend on XYZ so + + + align:start position:0% +and Z right these guys depend on XYZ so +it's actually one vector for each point + + align:start position:0% +it's actually one vector for each point + + + align:start position:0% +it's actually one vector for each point +XYZ you can talk about the + + align:start position:0% + + + + align:start position:0% + +gradient + + align:start position:0% +gradient + + + align:start position:0% +gradient +of w at some + + align:start position:0% + + + + align:start position:0% + +point + + align:start position:0% +point + + + align:start position:0% +point +XYZ so at each point it gives you a + + align:start position:0% +XYZ so at each point it gives you a + + + align:start position:0% +XYZ so at each point it gives you a +vector that actually is what we will + + align:start position:0% +vector that actually is what we will + + + align:start position:0% +vector that actually is what we will +call later a vector + + align:start position:0% +call later a vector + + + align:start position:0% +call later a vector +field but we'll get we'll get back to + + align:start position:0% +field but we'll get we'll get back to + + + align:start position:0% +field but we'll get we'll get back to +that + + align:start position:0% +that + + + align:start position:0% +that +later and + + align:start position:0% +later and + + + align:start position:0% +later and +drdt is just the velocity vector + + align:start position:0% +drdt is just the velocity vector + + + align:start position:0% +drdt is just the velocity vector +dxdt dydt + + align:start position:0% + + + + align:start position:0% + +DT okay + + align:start position:0% +DT okay + + + align:start position:0% +DT okay +so the new definition for + + align:start position:0% +so the new definition for + + + align:start position:0% +so the new definition for +today is the definition of the gradient + + align:start position:0% +today is the definition of the gradient + + + align:start position:0% +today is the definition of the gradient +vector and our goal will be to + + align:start position:0% +vector and our goal will be to + + + align:start position:0% +vector and our goal will be to +understand a bit better what does this + + align:start position:0% +understand a bit better what does this + + + align:start position:0% +understand a bit better what does this +Vector mean what does it measure and + + align:start position:0% +Vector mean what does it measure and + + + align:start position:0% +Vector mean what does it measure and +what can we do with + + align:start position:0% +what can we do with + + + align:start position:0% +what can we do with +it but you see that in terms of + + align:start position:0% +it but you see that in terms of + + + align:start position:0% +it but you see that in terms of +information content it's really the same + + align:start position:0% +information content it's really the same + + + align:start position:0% +information content it's really the same +information that's already in the + + align:start position:0% +information that's already in the + + + align:start position:0% +information that's already in the +partial derivative + + align:start position:0% +partial derivative + + + align:start position:0% +partial derivative +are in the + + align:start position:0% + + + + align:start position:0% + +differential + + align:start position:0% + + + + align:start position:0% + +so yes and I should say of course you + + align:start position:0% +so yes and I should say of course you + + + align:start position:0% +so yes and I should say of course you +can also use the gradient in other + + align:start position:0% +can also use the gradient in other + + + align:start position:0% +can also use the gradient in other +things like approximation formulas and + + align:start position:0% +things like approximation formulas and + + + align:start position:0% +things like approximation formulas and +so on it's just so far it's just + + align:start position:0% +so on it's just so far it's just + + + align:start position:0% +so on it's just so far it's just +notation it's a way to rewrite things + + align:start position:0% +notation it's a way to rewrite things + + + align:start position:0% +notation it's a way to rewrite things +but so here's the first pool property of + + align:start position:0% +but so here's the first pool property of + + + align:start position:0% +but so here's the first pool property of +the + + align:start position:0% + + + + align:start position:0% + +gradient so + + align:start position:0% +gradient so + + + align:start position:0% +gradient so +so I claim that the gradient Vector is + + align:start position:0% +so I claim that the gradient Vector is + + + align:start position:0% +so I claim that the gradient Vector is +perpendicular to the level + + align:start position:0% + + + + align:start position:0% + +surface corresponding + + align:start position:0% +surface corresponding + + + align:start position:0% +surface corresponding +to setting the function W equal to a + + align:start position:0% +to setting the function W equal to a + + + align:start position:0% +to setting the function W equal to a +constant okay + + align:start position:0% +constant okay + + + align:start position:0% +constant okay +so if I draw a contour + + align:start position:0% +so if I draw a contour + + + align:start position:0% +so if I draw a contour +plot of my function so I'm going to + + align:start position:0% +plot of my function so I'm going to + + + align:start position:0% +plot of my function so I'm going to +actually forget about Z because I want + + align:start position:0% +actually forget about Z because I want + + + align:start position:0% +actually forget about Z because I want +to draw a two variable contol plot so + + align:start position:0% +to draw a two variable contol plot so + + + align:start position:0% +to draw a two variable contol plot so +say I have a function of two variables X + + align:start position:0% +say I have a function of two variables X + + + align:start position:0% +say I have a function of two variables X +and Y then maybe it has some Contour + + align:start position:0% +and Y then maybe it has some Contour + + + align:start position:0% +and Y then maybe it has some Contour +plot and I'm saying if I take the + + align:start position:0% +plot and I'm saying if I take the + + + align:start position:0% +plot and I'm saying if I take the +gradient of the function at this point + + align:start position:0% +gradient of the function at this point + + + align:start position:0% +gradient of the function at this point +XY so I will have a vector well if I + + align:start position:0% +XY so I will have a vector well if I + + + align:start position:0% +XY so I will have a vector well if I +draw that Vector on top of a contour + + align:start position:0% +draw that Vector on top of a contour + + + align:start position:0% +draw that Vector on top of a contour +plot it's going to end up being + + align:start position:0% +plot it's going to end up being + + + align:start position:0% +plot it's going to end up being +perpendicular to the level curve at this + + align:start position:0% +perpendicular to the level curve at this + + + align:start position:0% +perpendicular to the level curve at this +point same thing if I have a function of + + align:start position:0% +point same thing if I have a function of + + + align:start position:0% +point same thing if I have a function of +three variables then I can try to draw + + align:start position:0% +three variables then I can try to draw + + + align:start position:0% +three variables then I can try to draw +its Contour plot of course I can't + + align:start position:0% +its Contour plot of course I can't + + + align:start position:0% +its Contour plot of course I can't +really do it because the Contour plot + + align:start position:0% +really do it because the Contour plot + + + align:start position:0% +really do it because the Contour plot +would be you know living in space with X + + align:start position:0% +would be you know living in space with X + + + align:start position:0% +would be you know living in space with X +Y and Z but it would be a bunch of level + + align:start position:0% +Y and Z but it would be a bunch of level + + + align:start position:0% +Y and Z but it would be a bunch of level +surfaces and the gradient Vector would + + align:start position:0% +surfaces and the gradient Vector would + + + align:start position:0% +surfaces and the gradient Vector would +be a vector in space that Vector is + + align:start position:0% +be a vector in space that Vector is + + + align:start position:0% +be a vector in space that Vector is +perpendicular to the level + + align:start position:0% +perpendicular to the level + + + align:start position:0% +perpendicular to the level +surfaces so let's try to see that on a + + align:start position:0% +surfaces so let's try to see that on a + + + align:start position:0% +surfaces so let's try to see that on a +couple of + + align:start position:0% + + + + align:start position:0% + +examples so let's do a first example + + align:start position:0% +examples so let's do a first example + + + align:start position:0% +examples so let's do a first example +let's do + + align:start position:0% +let's do + + + align:start position:0% +let's do +things you know what's the easiest case + + align:start position:0% + + + + align:start position:0% + +let's take a linear function of X Y and + + align:start position:0% +let's take a linear function of X Y and + + + align:start position:0% +let's take a linear function of X Y and +Z so I will take W equals A1 * X Plus A2 + + align:start position:0% +Z so I will take W equals A1 * X Plus A2 + + + align:start position:0% +Z so I will take W equals A1 * X Plus A2 +* y plus A3 * + + align:start position:0% +* y plus A3 * + + + align:start position:0% +* y plus A3 * +Z + + align:start position:0% +Z + + + align:start position:0% +Z +well so what's the gradient of this + + align:start position:0% + + + + align:start position:0% + +function well the first component will + + align:start position:0% +function well the first component will + + + align:start position:0% +function well the first component will +be A1 that's partial W partial + + align:start position:0% + + + + align:start position:0% + +X then A2 that's partial W partial Y and + + align:start position:0% +X then A2 that's partial W partial Y and + + + align:start position:0% +X then A2 that's partial W partial Y and +A3 partial W partial Z okay + + align:start position:0% +A3 partial W partial Z okay + + + align:start position:0% +A3 partial W partial Z okay +now what are the level + + align:start position:0% + + + + align:start position:0% + +surfaces well if I set W equal to some + + align:start position:0% +surfaces well if I set W equal to some + + + align:start position:0% +surfaces well if I set W equal to some +constant C that means I look at the + + align:start position:0% +constant C that means I look at the + + + align:start position:0% +constant C that means I look at the +points where a1x + A2 y plus f p z + + align:start position:0% +points where a1x + A2 y plus f p z + + + align:start position:0% +points where a1x + A2 y plus f p z +equals c what kind of surface is that + + align:start position:0% +equals c what kind of surface is that + + + align:start position:0% +equals c what kind of surface is that +it's a plane + + align:start position:0% +it's a plane + + + align:start position:0% +it's a plane +and we know how to find a normal Vector + + align:start position:0% +and we know how to find a normal Vector + + + align:start position:0% +and we know how to find a normal Vector +to this plane just by looking at the + + align:start position:0% + + + + align:start position:0% + +coefficients so it's a plane with normal + + align:start position:0% +coefficients so it's a plane with normal + + + align:start position:0% +coefficients so it's a plane with normal +Vector exactly this + + align:start position:0% +Vector exactly this + + + align:start position:0% +Vector exactly this +gradient and in fact you know in a way + + align:start position:0% +gradient and in fact you know in a way + + + align:start position:0% +gradient and in fact you know in a way +this is the only case you need to check + + align:start position:0% +this is the only case you need to check + + + align:start position:0% +this is the only case you need to check +because of linear approximation if you + + align:start position:0% +because of linear approximation if you + + + align:start position:0% +because of linear approximation if you +replace a function by its linear + + align:start position:0% +replace a function by its linear + + + align:start position:0% +replace a function by its linear +approximation that means you will + + align:start position:0% +approximation that means you will + + + align:start position:0% +approximation that means you will +replace the level surfaces by their + + align:start position:0% +replace the level surfaces by their + + + align:start position:0% +replace the level surfaces by their +tangent planes and then you will + + align:start position:0% +tangent planes and then you will + + + align:start position:0% +tangent planes and then you will +actually end up in this situation but + + align:start position:0% +actually end up in this situation but + + + align:start position:0% +actually end up in this situation but +maybe that's not very convincing so + + align:start position:0% +maybe that's not very convincing so + + + align:start position:0% +maybe that's not very convincing so +let's do another + + align:start position:0% + + + + align:start position:0% + +example + + align:start position:0% +example + + + align:start position:0% +example +so let's do a second + + align:start position:0% + + + + align:start position:0% + +example let's say we look at the + + align:start position:0% +example let's say we look at the + + + align:start position:0% +example let's say we look at the +function x² + y^2 okay so now it's a + + align:start position:0% +function x² + y^2 okay so now it's a + + + align:start position:0% +function x² + y^2 okay so now it's a +function of just two variables because + + align:start position:0% +function of just two variables because + + + align:start position:0% +function of just two variables because +that way I will be able to actually draw + + align:start position:0% +that way I will be able to actually draw + + + align:start position:0% +that way I will be able to actually draw +a picture for + + align:start position:0% + + + + align:start position:0% + +you okay so what are the level sets of + + align:start position:0% +you okay so what are the level sets of + + + align:start position:0% +you okay so what are the level sets of +this function well they're going to be + + align:start position:0% +this function well they're going to be + + + align:start position:0% +this function well they're going to be +circles + + align:start position:0% +circles + + + align:start position:0% +circles +right wal C is a + + align:start position:0% +right wal C is a + + + align:start position:0% +right wal C is a +circle X2 + Y2 = + + align:start position:0% +circle X2 + Y2 = + + + align:start position:0% +circle X2 + Y2 = +C so you should say maybe sorry say the + + align:start position:0% +C so you should say maybe sorry say the + + + align:start position:0% +C so you should say maybe sorry say the +level + + align:start position:0% + + + + align:start position:0% + +curve is a circle + + align:start position:0% + + + + align:start position:0% + +so the Contour plot looks something like + + align:start position:0% + + + + align:start position:0% + +that now what's the gradient + + align:start position:0% +that now what's the gradient + + + align:start position:0% +that now what's the gradient +Vector well the gradient of this + + align:start position:0% +Vector well the gradient of this + + + align:start position:0% +Vector well the gradient of this +function so partial W partial X + + align:start position:0% +function so partial W partial X + + + align:start position:0% +function so partial W partial X +is + + align:start position:0% +is + + + align:start position:0% +is +2X and Par W par Y is 2 y so let's say I + + align:start position:0% +2X and Par W par Y is 2 y so let's say I + + + align:start position:0% +2X and Par W par Y is 2 y so let's say I +take a point x comma y + + align:start position:0% +take a point x comma y + + + align:start position:0% +take a point x comma y +and I try to draw my gradiant Vector so + + align:start position:0% +and I try to draw my gradiant Vector so + + + align:start position:0% +and I try to draw my gradiant Vector so +here at + + align:start position:0% +here at + + + align:start position:0% +here at +XY so I have to draw the vector 2x 2 Y + + align:start position:0% +XY so I have to draw the vector 2x 2 Y + + + align:start position:0% +XY so I have to draw the vector 2x 2 Y +what does it look + + align:start position:0% +what does it look + + + align:start position:0% +what does it look +like well it's going in that direction + + align:start position:0% +like well it's going in that direction + + + align:start position:0% +like well it's going in that direction +it's parallel to the + + align:start position:0% +it's parallel to the + + + align:start position:0% +it's parallel to the +position Vector for this point and it's + + align:start position:0% +position Vector for this point and it's + + + align:start position:0% +position Vector for this point and it's +actually twice the position Vector so I + + align:start position:0% +actually twice the position Vector so I + + + align:start position:0% +actually twice the position Vector so I +guess it goes more or less like + + align:start position:0% +guess it goes more or less like + + + align:start position:0% +guess it goes more or less like +this what's interesting to us is it is + + align:start position:0% +this what's interesting to us is it is + + + align:start position:0% +this what's interesting to us is it is +perpendicular to this + + align:start position:0% +perpendicular to this + + + align:start position:0% +perpendicular to this +circle okay so it's a general feature + + align:start position:0% +circle okay so it's a general feature + + + align:start position:0% +circle okay so it's a general feature +let me show + + align:start position:0% +let me show + + + align:start position:0% +let me show +you more + + align:start position:0% +you more + + + align:start position:0% +you more +examples oops not the one I + + align:start position:0% +examples oops not the one I + + + align:start position:0% +examples oops not the one I +want so I don't know if you can see it + + align:start position:0% +want so I don't know if you can see it + + + align:start position:0% +want so I don't know if you can see it +so well well hopefully you can so here I + + align:start position:0% +so well well hopefully you can so here I + + + align:start position:0% +so well well hopefully you can so here I +have a contour plot of a function and I + + align:start position:0% +have a contour plot of a function and I + + + align:start position:0% +have a contour plot of a function and I +have a blue Vector that's the gradient + + align:start position:0% +have a blue Vector that's the gradient + + + align:start position:0% +have a blue Vector that's the gradient +Vector at the pink point on the plot so + + align:start position:0% +Vector at the pink point on the plot so + + + align:start position:0% +Vector at the pink point on the plot so +can see I can move the pink point and + + align:start position:0% +can see I can move the pink point and + + + align:start position:0% +can see I can move the pink point and +the gradient Vector of course changes + + align:start position:0% +the gradient Vector of course changes + + + align:start position:0% +the gradient Vector of course changes +because the gradient depends on X and Y + + align:start position:0% +because the gradient depends on X and Y + + + align:start position:0% +because the gradient depends on X and Y +but what doesn't change is that it's + + align:start position:0% +but what doesn't change is that it's + + + align:start position:0% +but what doesn't change is that it's +always perpendicular to the level + + align:start position:0% +always perpendicular to the level + + + align:start position:0% +always perpendicular to the level +curves anywhere where I + + align:start position:0% +curves anywhere where I + + + align:start position:0% +curves anywhere where I +am my gradient stays + + align:start position:0% +am my gradient stays + + + align:start position:0% +am my gradient stays +perpendicular to the level + + align:start position:0% +perpendicular to the level + + + align:start position:0% +perpendicular to the level +curve okay is that convincing is that + + align:start position:0% +curve okay is that convincing is that + + + align:start position:0% +curve okay is that convincing is that +visible even for people who can see + + align:start position:0% +visible even for people who can see + + + align:start position:0% +visible even for people who can see +blue okay + + align:start position:0% + + + + align:start position:0% + +so okay so we have a lot of evidence but + + align:start position:0% +so okay so we have a lot of evidence but + + + align:start position:0% +so okay so we have a lot of evidence but +you know let's try to prove the theorem + + align:start position:0% +you know let's try to prove the theorem + + + align:start position:0% +you know let's try to prove the theorem +because it will + + align:start position:0% +because it will + + + align:start position:0% +because it will +be + + align:start position:0% +be + + + align:start position:0% +be +interesting + + align:start position:0% + + + + align:start position:0% + +so oh first of all sorry any questions + + align:start position:0% +so oh first of all sorry any questions + + + align:start position:0% +so oh first of all sorry any questions +about the statement the examples + + align:start position:0% +about the statement the examples + + + align:start position:0% +about the statement the examples +yes + + align:start position:0% + + + + align:start position:0% + +ah very good question does the gradient + + align:start position:0% +ah very good question does the gradient + + + align:start position:0% +ah very good question does the gradient +Vector why is the gradient Vector + + align:start position:0% +Vector why is the gradient Vector + + + align:start position:0% +Vector why is the gradient Vector +perpendicular in One Direction rather + + align:start position:0% +perpendicular in One Direction rather + + + align:start position:0% +perpendicular in One Direction rather +than the other so we'll see the answer + + align:start position:0% +than the other so we'll see the answer + + + align:start position:0% +than the other so we'll see the answer +to that in a few minutes but let me just + + align:start position:0% +to that in a few minutes but let me just + + + align:start position:0% +to that in a few minutes but let me just +tell you + + align:start position:0% +tell you + + + align:start position:0% +tell you +immediately uh to decide which side it's + + align:start position:0% +immediately uh to decide which side it's + + + align:start position:0% +immediately uh to decide which side it's +pointing to it's always pointing towards + + align:start position:0% +pointing to it's always pointing towards + + + align:start position:0% +pointing to it's always pointing towards +higher values of a function okay and + + align:start position:0% +higher values of a function okay and + + + align:start position:0% +higher values of a function okay and +we'll see that maybe in about half an + + align:start position:0% +we'll see that maybe in about half an + + + align:start position:0% +we'll see that maybe in about half an +hour + + align:start position:0% +hour + + + align:start position:0% +hour +so well let me say actually + + align:start position:0% +so well let me say actually + + + align:start position:0% +so well let me say actually +points + + align:start position:0% +points + + + align:start position:0% +points +towards higher + + align:start position:0% + + + + align:start position:0% + +values of + + align:start position:0% + + + + align:start position:0% + +w okay any other + + align:start position:0% + + + + align:start position:0% + +questions I don't see any questions so + + align:start position:0% +questions I don't see any questions so + + + align:start position:0% +questions I don't see any questions so +okay so let's try to prove this theorem + + align:start position:0% +okay so let's try to prove this theorem + + + align:start position:0% +okay so let's try to prove this theorem +at least this part of the theorem we are + + align:start position:0% +at least this part of the theorem we are + + + align:start position:0% +at least this part of the theorem we are +not going to prove that just yet that + + align:start position:0% +not going to prove that just yet that + + + align:start position:0% +not going to prove that just yet that +will come in a + + align:start position:0% + + + + align:start position:0% + +while + + align:start position:0% +while + + + align:start position:0% +while +so + + align:start position:0% +so + + + align:start position:0% +so +well maybe we want to understand first + + align:start position:0% +well maybe we want to understand first + + + align:start position:0% +well maybe we want to understand first +what happens if we move inside the level + + align:start position:0% +what happens if we move inside the level + + + align:start position:0% +what happens if we move inside the level +curve okay so let's imagine that we're + + align:start position:0% +curve okay so let's imagine that we're + + + align:start position:0% +curve okay so let's imagine that we're +taking a moving point that stays on the + + align:start position:0% +taking a moving point that stays on the + + + align:start position:0% +taking a moving point that stays on the +level curve or on the level + + align:start position:0% +level curve or on the level + + + align:start position:0% +level curve or on the level +surface and then we know well what + + align:start position:0% +surface and then we know well what + + + align:start position:0% +surface and then we know well what +happens is that the function stays + + align:start position:0% +happens is that the function stays + + + align:start position:0% +happens is that the function stays +constant but we can also know how + + align:start position:0% +constant but we can also know how + + + align:start position:0% +constant but we can also know how +quickly the function changes using the + + align:start position:0% +quickly the function changes using the + + + align:start position:0% +quickly the function changes using the +chain rule up there so maybe the chain + + align:start position:0% +chain rule up there so maybe the chain + + + align:start position:0% +chain rule up there so maybe the chain +rule will actually be the key to + + align:start position:0% +rule will actually be the key to + + + align:start position:0% +rule will actually be the key to +understanding how the gradient vector + + align:start position:0% +understanding how the gradient vector + + + align:start position:0% +understanding how the gradient vector +and a motion on the level surface + + align:start position:0% +and a motion on the level surface + + + align:start position:0% +and a motion on the level surface +relate so let's take a + + align:start position:0% +relate so let's take a + + + align:start position:0% +relate so let's take a +curve rals R of + + align:start position:0% +curve rals R of + + + align:start position:0% +curve rals R of +T that + + align:start position:0% +T that + + + align:start position:0% +T that +stays + + align:start position:0% + + + + align:start position:0% + +inside well maybe I should say on the + + align:start position:0% +inside well maybe I should say on the + + + align:start position:0% +inside well maybe I should say on the +level + + align:start position:0% + + + + align:start position:0% + +surface W equals + + align:start position:0% +surface W equals + + + align:start position:0% +surface W equals +c okay + + align:start position:0% +c okay + + + align:start position:0% +c okay +so let's think about what that means so + + align:start position:0% +so let's think about what that means so + + + align:start position:0% +so let's think about what that means so +just to get you used to this idea I'm + + align:start position:0% +just to get you used to this idea I'm + + + align:start position:0% +just to get you used to this idea I'm +going to draw a level surface of a + + align:start position:0% +going to draw a level surface of a + + + align:start position:0% +going to draw a level surface of a +function of three variables okay so it's + + align:start position:0% +function of three variables okay so it's + + + align:start position:0% +function of three variables okay so it's +some surface given by the equation W of + + align:start position:0% +some surface given by the equation W of + + + align:start position:0% +some surface given by the equation W of +XYZ equals some constant + + align:start position:0% +XYZ equals some constant + + + align:start position:0% +XYZ equals some constant +C and so now I'm going to have a point + + align:start position:0% +C and so now I'm going to have a point + + + align:start position:0% +C and so now I'm going to have a point +on that and it's going to move on that + + align:start position:0% +on that and it's going to move on that + + + align:start position:0% +on that and it's going to move on that +surface so I will have you know some + + align:start position:0% +surface so I will have you know some + + + align:start position:0% +surface so I will have you know some +parametric + + align:start position:0% +parametric + + + align:start position:0% +parametric +curve that lives on this + + align:start position:0% +curve that lives on this + + + align:start position:0% +curve that lives on this +surface so the question + + align:start position:0% +surface so the question + + + align:start position:0% +surface so the question +is what's going to + + align:start position:0% +is what's going to + + + align:start position:0% +is what's going to +happen at any given time well the first + + align:start position:0% +happen at any given time well the first + + + align:start position:0% +happen at any given time well the first +observation is that the velocity Vector + + align:start position:0% +observation is that the velocity Vector + + + align:start position:0% +observation is that the velocity Vector +what can I say about the velocity + + align:start position:0% +what can I say about the velocity + + + align:start position:0% +what can I say about the velocity +Vector of this motion it's going to be + + align:start position:0% +Vector of this motion it's going to be + + + align:start position:0% +Vector of this motion it's going to be +tangent to the level surface right if I + + align:start position:0% +tangent to the level surface right if I + + + align:start position:0% +tangent to the level surface right if I +move on a Surface then at any point my + + align:start position:0% +move on a Surface then at any point my + + + align:start position:0% +move on a Surface then at any point my +velocity is tangent to the curve but if + + align:start position:0% +velocity is tangent to the curve but if + + + align:start position:0% +velocity is tangent to the curve but if +it's tangent to the curve then it's also + + align:start position:0% +it's tangent to the curve then it's also + + + align:start position:0% +it's tangent to the curve then it's also +tangent to the + + align:start position:0% +tangent to the + + + align:start position:0% +tangent to the +surface because the curve is inside the + + align:start position:0% +surface because the curve is inside the + + + align:start position:0% +surface because the curve is inside the +surface so okay it's getting a bit + + align:start position:0% +surface so okay it's getting a bit + + + align:start position:0% +surface so okay it's getting a bit +cluttered maybe I should draw a bigger + + align:start position:0% +cluttered maybe I should draw a bigger + + + align:start position:0% +cluttered maybe I should draw a bigger +picture let me do that right away here + + align:start position:0% + + + + align:start position:0% + +so I have my level surface wal C I have + + align:start position:0% +so I have my level surface wal C I have + + + align:start position:0% +so I have my level surface wal C I have +a curve on + + align:start position:0% +a curve on + + + align:start position:0% +a curve on +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +that + + align:start position:0% +that + + + align:start position:0% +that +and at some + + align:start position:0% +and at some + + + align:start position:0% +and at some +point I'm going to have a certain + + align:start position:0% +point I'm going to have a certain + + + align:start position:0% +point I'm going to have a certain +velocity so the claim is + + align:start position:0% + + + + align:start position:0% + +that the + + align:start position:0% +that the + + + align:start position:0% +that the +velocity + + align:start position:0% +velocity + + + align:start position:0% +velocity +V equals + + align:start position:0% +V equals + + + align:start position:0% +V equals +drdt is + + align:start position:0% + + + + align:start position:0% + +tangent to the level W equals + + align:start position:0% +tangent to the level W equals + + + align:start position:0% +tangent to the level W equals +c because it's tangent to the curve and + + align:start position:0% +c because it's tangent to the curve and + + + align:start position:0% +c because it's tangent to the curve and +the curve is inside the level okay now + + align:start position:0% +the curve is inside the level okay now + + + align:start position:0% +the curve is inside the level okay now +what else can we say + + align:start position:0% +what else can we say + + + align:start position:0% +what else can we say +well we have the chain rule to tell us + + align:start position:0% +well we have the chain rule to tell us + + + align:start position:0% +well we have the chain rule to tell us +how the Val of w + + align:start position:0% +how the Val of w + + + align:start position:0% +how the Val of w +changes so by the chain + + align:start position:0% + + + + align:start position:0% + +rule we have DW + + align:start position:0% +rule we have DW + + + align:start position:0% +rule we have DW +DT so the rate of change of the value of + + align:start position:0% +DT so the rate of change of the value of + + + align:start position:0% +DT so the rate of change of the value of +w as I move along this curve is given by + + align:start position:0% +w as I move along this curve is given by + + + align:start position:0% +w as I move along this curve is given by +the dot product between the + + align:start position:0% +the dot product between the + + + align:start position:0% +the dot product between the +gradient and the velocity + + align:start position:0% + + + + align:start position:0% + +vector + + align:start position:0% + + + + align:start position:0% + +and so well maybe I can rewrite it as NE + + align:start position:0% +and so well maybe I can rewrite it as NE + + + align:start position:0% +and so well maybe I can rewrite it as NE +W sorry uh d + + align:start position:0% +W sorry uh d + + + align:start position:0% +W sorry uh d +w + + align:start position:0% +w + + + align:start position:0% +w +v um and that should be well what should + + align:start position:0% +v um and that should be well what should + + + align:start position:0% +v um and that should be well what should +it be what happens to the value of w as + + align:start position:0% +it be what happens to the value of w as + + + align:start position:0% +it be what happens to the value of w as +T + + align:start position:0% +T + + + align:start position:0% +T +changes well it stays constant because + + align:start position:0% +changes well it stays constant because + + + align:start position:0% +changes well it stays constant because +we are moving on a curve that curve + + align:start position:0% +we are moving on a curve that curve + + + align:start position:0% +we are moving on a curve that curve +might be complicated but it stays always + + align:start position:0% +might be complicated but it stays always + + + align:start position:0% +might be complicated but it stays always +on the level W equals + + align:start position:0% +on the level W equals + + + align:start position:0% +on the level W equals +c so it's zero + + align:start position:0% + + + + align:start position:0% + +because W of T equals c which is a + + align:start position:0% + + + + align:start position:0% + +constant okay is that + + align:start position:0% +constant okay is that + + + align:start position:0% +constant okay is that +convincing y okay so now if we have a + + align:start position:0% +convincing y okay so now if we have a + + + align:start position:0% +convincing y okay so now if we have a +DOT product that's zero that tells us + + align:start position:0% +DOT product that's zero that tells us + + + align:start position:0% +DOT product that's zero that tells us +that these two guys are + + align:start position:0% +that these two guys are + + + align:start position:0% +that these two guys are +perpendicular + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% + + + + align:start position:0% + +so the gradient Vector is perpendicular + + align:start position:0% +so the gradient Vector is perpendicular + + + align:start position:0% +so the gradient Vector is perpendicular +to + + align:start position:0% + + + + align:start position:0% + +V okay that's a good start we know that + + align:start position:0% +V okay that's a good start we know that + + + align:start position:0% +V okay that's a good start we know that +the gradient is perpendicular to this + + align:start position:0% +the gradient is perpendicular to this + + + align:start position:0% +the gradient is perpendicular to this +Vector tangent that's tangent to the + + align:start position:0% +Vector tangent that's tangent to the + + + align:start position:0% +Vector tangent that's tangent to the +level surface what about other vectors + + align:start position:0% +level surface what about other vectors + + + align:start position:0% +level surface what about other vectors +tangent to the level + + align:start position:0% +tangent to the level + + + align:start position:0% +tangent to the level +surface well in fact I could use any + + align:start position:0% +surface well in fact I could use any + + + align:start position:0% +surface well in fact I could use any +curve drawn on the level wal C + + align:start position:0% +curve drawn on the level wal C + + + align:start position:0% +curve drawn on the level wal C +so I could move really any way I wanted + + align:start position:0% +so I could move really any way I wanted + + + align:start position:0% +so I could move really any way I wanted +on that + + align:start position:0% +on that + + + align:start position:0% +on that +surface in + + align:start position:0% +surface in + + + align:start position:0% +surface in +particular I claim that I could have + + align:start position:0% +particular I claim that I could have + + + align:start position:0% +particular I claim that I could have +chosen my velocity Vector to be any + + align:start position:0% +chosen my velocity Vector to be any + + + align:start position:0% +chosen my velocity Vector to be any +Vector tangent to the + + align:start position:0% + + + + align:start position:0% + +surface okay so let's write this so this + + align:start position:0% +surface okay so let's write this so this + + + align:start position:0% +surface okay so let's write this so this +is true + + align:start position:0% +is true + + + align:start position:0% +is true +for + + align:start position:0% +for + + + align:start position:0% +for +any + + align:start position:0% +any + + + align:start position:0% +any +curve well say for any + + align:start position:0% + + + + align:start position:0% + +motion on + + align:start position:0% +motion on + + + align:start position:0% +motion on +the level surface W equal C so that + + align:start position:0% + + + + align:start position:0% + +means V can + + align:start position:0% +means V can + + + align:start position:0% +means V can +be any + + align:start position:0% + + + + align:start position:0% + +Vector + + align:start position:0% +Vector + + + align:start position:0% +Vector +tangent to the + + align:start position:0% +tangent to the + + + align:start position:0% +tangent to the +surface tangent + + align:start position:0% +surface tangent + + + align:start position:0% +surface tangent +to the level um see for example let me + + align:start position:0% +to the level um see for example let me + + + align:start position:0% +to the level um see for example let me +draw one more + + align:start position:0% +draw one more + + + align:start position:0% +draw one more +picture + + align:start position:0% + + + + align:start position:0% + +okay so I have my level surface so I'm + + align:start position:0% +okay so I have my level surface so I'm + + + align:start position:0% +okay so I have my level surface so I'm +drawing more and more levels and the + + align:start position:0% +drawing more and more levels and the + + + align:start position:0% +drawing more and more levels and the +Never quite look the same but and I have + + align:start position:0% +Never quite look the same but and I have + + + align:start position:0% +Never quite look the same but and I have +a point and at this point I have the + + align:start position:0% +a point and at this point I have the + + + align:start position:0% +a point and at this point I have the +tangent plane to the level surface okay + + align:start position:0% +tangent plane to the level surface okay + + + align:start position:0% +tangent plane to the level surface okay +so this + + align:start position:0% +so this + + + align:start position:0% +so this +is tangent + + align:start position:0% + + + + align:start position:0% + +plane to the + + align:start position:0% +plane to the + + + align:start position:0% +plane to the +level then if I choose any VOR in that + + align:start position:0% +level then if I choose any VOR in that + + + align:start position:0% +level then if I choose any VOR in that +tangent plane let's say I choose and no + + align:start position:0% +tangent plane let's say I choose and no + + + align:start position:0% +tangent plane let's say I choose and no +but when that goes in that + + align:start position:0% +but when that goes in that + + + align:start position:0% +but when that goes in that +direction then I can actually find a + + align:start position:0% +direction then I can actually find a + + + align:start position:0% +direction then I can actually find a +curve that goes in that direction and + + align:start position:0% +curve that goes in that direction and + + + align:start position:0% +curve that goes in that direction and +stays on the level so here that would be + + align:start position:0% +stays on the level so here that would be + + + align:start position:0% +stays on the level so here that would be +a curve that somehow goes from the right + + align:start position:0% +a curve that somehow goes from the right + + + align:start position:0% +a curve that somehow goes from the right +to the left and of course it has to end + + align:start position:0% +to the left and of course it has to end + + + align:start position:0% +to the left and of course it has to end +up going up or something like + + align:start position:0% +up going up or something like + + + align:start position:0% +up going up or something like +that okay so + + align:start position:0% +that okay so + + + align:start position:0% +that okay so +given any + + align:start position:0% + + + + align:start position:0% + +Vector + + align:start position:0% + + + + align:start position:0% + +tangent let's call that vector v tangent + + align:start position:0% +tangent let's call that vector v tangent + + + align:start position:0% +tangent let's call that vector v tangent +to the + + align:start position:0% + + + + align:start position:0% + +level we get that the gradient is + + align:start position:0% +level we get that the gradient is + + + align:start position:0% +level we get that the gradient is +perpendicular to V so the gradient is + + align:start position:0% +perpendicular to V so the gradient is + + + align:start position:0% +perpendicular to V so the gradient is +perpendicular to this Vector tangent to + + align:start position:0% +perpendicular to this Vector tangent to + + + align:start position:0% +perpendicular to this Vector tangent to +this curve but also to you know any + + align:start position:0% +this curve but also to you know any + + + align:start position:0% +this curve but also to you know any +Vector I can draw that's tangent to my + + align:start position:0% +Vector I can draw that's tangent to my + + + align:start position:0% +Vector I can draw that's tangent to my +Surface so what does that mean well that + + align:start position:0% +Surface so what does that mean well that + + + align:start position:0% +Surface so what does that mean well that +means the gradient is actually + + align:start position:0% +means the gradient is actually + + + align:start position:0% +means the gradient is actually +perpendicular to the tangent plane or to + + align:start position:0% +perpendicular to the tangent plane or to + + + align:start position:0% +perpendicular to the tangent plane or to +the surface at this + + align:start position:0% +the surface at this + + + align:start position:0% +the surface at this +point so the + + align:start position:0% + + + + align:start position:0% + +gradient is + + align:start position:0% + + + + align:start position:0% + +perpendicular + + align:start position:0% + + + + align:start position:0% + +and well here I've Illustrated things + + align:start position:0% +and well here I've Illustrated things + + + align:start position:0% +and well here I've Illustrated things +with a threedimensional example but + + align:start position:0% +with a threedimensional example but + + + align:start position:0% +with a threedimensional example but +really it works the same if you have + + align:start position:0% +really it works the same if you have + + + align:start position:0% +really it works the same if you have +only two variables when you have a level + + align:start position:0% +only two variables when you have a level + + + align:start position:0% +only two variables when you have a level +curve it has a tangent line and the + + align:start position:0% +curve it has a tangent line and the + + + align:start position:0% +curve it has a tangent line and the +gradient is perpendicular to that + + align:start position:0% + + + + align:start position:0% + +line okay any + + align:start position:0% + + + + align:start position:0% + +questions + + align:start position:0% + + + + align:start position:0% + +no okay + + align:start position:0% + + + + align:start position:0% + +so let's see that's actually pretty neat + + align:start position:0% +so let's see that's actually pretty neat + + + align:start position:0% +so let's see that's actually pretty neat +because there's a nice application of + + align:start position:0% +because there's a nice application of + + + align:start position:0% +because there's a nice application of +this which is to try to figure out now + + align:start position:0% +this which is to try to figure out now + + + align:start position:0% +this which is to try to figure out now +we know actually how to find the tangent + + align:start position:0% +we know actually how to find the tangent + + + align:start position:0% +we know actually how to find the tangent +plane to anything pretty + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +much + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so let's + + align:start position:0% +so let's + + + align:start position:0% +so let's +see so let's say that for example I want + + align:start position:0% +see so let's say that for example I want + + + align:start position:0% +see so let's say that for example I want +to + + align:start position:0% + + + + align:start position:0% + +find + + align:start position:0% +find + + + align:start position:0% +find +the tensent + + align:start position:0% + + + + align:start position:0% + +plane + + align:start position:0% +plane + + + align:start position:0% +plane +to the + + align:start position:0% +to the + + + align:start position:0% +to the +surface with + + align:start position:0% +surface with + + + align:start position:0% +surface with +equation let's say X2 + y^ 2us z^2 = + + align:start position:0% +equation let's say X2 + y^ 2us z^2 = + + + align:start position:0% +equation let's say X2 + y^ 2us z^2 = +4 at the point 21 1 let me write + + align:start position:0% +4 at the point 21 1 let me write + + + align:start position:0% +4 at the point 21 1 let me write +[Music] + + align:start position:0% + + + + align:start position:0% + +that + + align:start position:0% + + + + align:start position:0% + +so how do we do that well one way that + + align:start position:0% +so how do we do that well one way that + + + align:start position:0% +so how do we do that well one way that +we already + + align:start position:0% +we already + + + align:start position:0% +we already +know if we solve this for Z so we can + + align:start position:0% +know if we solve this for Z so we can + + + align:start position:0% +know if we solve this for Z so we can +write z equals function of X and Y then + + align:start position:0% +write z equals function of X and Y then + + + align:start position:0% +write z equals function of X and Y then +we know tangent plane + + align:start position:0% +we know tangent plane + + + align:start position:0% +we know tangent plane +approximation for the graph of a + + align:start position:0% +approximation for the graph of a + + + align:start position:0% +approximation for the graph of a +function Z equals some function of X and + + align:start position:0% +function Z equals some function of X and + + + align:start position:0% +function Z equals some function of X and +Y but that doesn't look like it's the + + align:start position:0% +Y but that doesn't look like it's the + + + align:start position:0% +Y but that doesn't look like it's the +best way to do it okay the best way to + + align:start position:0% +best way to do it okay the best way to + + + align:start position:0% +best way to do it okay the best way to +do it now that we have the gradient + + align:start position:0% +do it now that we have the gradient + + + align:start position:0% +do it now that we have the gradient +Vector is actually to directly say oh we + + align:start position:0% +Vector is actually to directly say oh we + + + align:start position:0% +Vector is actually to directly say oh we +we know the normal Vector to this plane + + align:start position:0% +we know the normal Vector to this plane + + + align:start position:0% +we know the normal Vector to this plane +the normal Vector will just be the + + align:start position:0% +the normal Vector will just be the + + + align:start position:0% +the normal Vector will just be the +gradient oh I think I have a cool + + align:start position:0% +gradient oh I think I have a cool + + + align:start position:0% +gradient oh I think I have a cool +picture to show + + align:start position:0% +picture to show + + + align:start position:0% +picture to show +so okay so that's what it looks + + align:start position:0% +so okay so that's what it looks + + + align:start position:0% +so okay so that's what it looks +like okay so here you have the surface + + align:start position:0% +like okay so here you have the surface + + + align:start position:0% +like okay so here you have the surface +x² + y sare - zare = 4 that's called a + + align:start position:0% +x² + y sare - zare = 4 that's called a + + + align:start position:0% +x² + y sare - zare = 4 that's called a +hyperboloid because it looks like what + + align:start position:0% +hyperboloid because it looks like what + + + align:start position:0% +hyperboloid because it looks like what +you get when you spin a hyperbola around + + align:start position:0% +you get when you spin a hyperbola around + + + align:start position:0% +you get when you spin a hyperbola around +an axis and here's its tangent plane at + + align:start position:0% +an axis and here's its tangent plane at + + + align:start position:0% +an axis and here's its tangent plane at +the given point so it doesn't look very + + align:start position:0% +the given point so it doesn't look very + + + align:start position:0% +the given point so it doesn't look very +tangent because it crosses the surface + + align:start position:0% +tangent because it crosses the surface + + + align:start position:0% +tangent because it crosses the surface +but it's really I mean if you think + + align:start position:0% +but it's really I mean if you think + + + align:start position:0% +but it's really I mean if you think +about it you'll see that's really the + + align:start position:0% +about it you'll see that's really the + + + align:start position:0% +about it you'll see that's really the +plane that's approximating the + + align:start position:0% +plane that's approximating the + + + align:start position:0% +plane that's approximating the +surface in the best way that you can at + + align:start position:0% +surface in the best way that you can at + + + align:start position:0% +surface in the best way that you can at +this given point it is really the + + align:start position:0% +this given point it is really the + + + align:start position:0% +this given point it is really the +tangent + + align:start position:0% + + + + align:start position:0% + +plane + + align:start position:0% + + + + align:start position:0% + +so how do we find this + + align:start position:0% +so how do we find this + + + align:start position:0% +so how do we find this +plane well you can plot it on a computer + + align:start position:0% +plane well you can plot it on a computer + + + align:start position:0% +plane well you can plot it on a computer +but that's not exactly + + align:start position:0% +but that's not exactly + + + align:start position:0% +but that's not exactly +you know how you would look for it in + + align:start position:0% +you know how you would look for it in + + + align:start position:0% +you know how you would look for it in +the first place so the way to do it is + + align:start position:0% +the first place so the way to do it is + + + align:start position:0% +the first place so the way to do it is +that we compute the gradient so the + + align:start position:0% +that we compute the gradient so the + + + align:start position:0% +that we compute the gradient so the +gradient of what well the gradient of + + align:start position:0% +gradient of what well the gradient of + + + align:start position:0% +gradient of what well the gradient of +this + + align:start position:0% +this + + + align:start position:0% +this +function okay + + align:start position:0% +function okay + + + align:start position:0% +function okay +so so it should say this is the level + + align:start position:0% +so so it should say this is the level + + + align:start position:0% +so so it should say this is the level +set W = 4 + + align:start position:0% +set W = 4 + + + align:start position:0% +set W = 4 +where W is x² + y^ 2us z^ + + align:start position:0% +where W is x² + y^ 2us z^ + + + align:start position:0% +where W is x² + y^ 2us z^ +2 and so we know that the gradient of + + align:start position:0% + + + + align:start position:0% + +this well what is + + align:start position:0% +this well what is + + + align:start position:0% +this well what is +it 2x then 2 Y and then -2 + + align:start position:0% +it 2x then 2 Y and then -2 + + + align:start position:0% +it 2x then 2 Y and then -2 +Z so at this given + + align:start position:0% +Z so at this given + + + align:start position:0% +Z so at this given +point I guess we're at xal 2 so that's + + align:start position:0% +point I guess we're at xal 2 so that's + + + align:start position:0% +point I guess we're at xal 2 so that's +four and then y and z are 1 so 2 + + align:start position:0% +four and then y and z are 1 so 2 + + + align:start position:0% +four and then y and z are 1 so 2 +-2 okay and that's going to be the + + align:start position:0% +-2 okay and that's going to be the + + + align:start position:0% +-2 okay and that's going to be the +normal + + align:start position:0% + + + + align:start position:0% + +Vector to the surface or to the tangent + + align:start position:0% +Vector to the surface or to the tangent + + + align:start position:0% +Vector to the surface or to the tangent +plane and that's one way to define the + + align:start position:0% +plane and that's one way to define the + + + align:start position:0% +plane and that's one way to define the +tangent plane right it has the same + + align:start position:0% +tangent plane right it has the same + + + align:start position:0% +tangent plane right it has the same +normal Vector as the surface or that's + + align:start position:0% +normal Vector as the surface or that's + + + align:start position:0% +normal Vector as the surface or that's +one way to define the normal Vector to + + align:start position:0% +one way to define the normal Vector to + + + align:start position:0% +one way to define the normal Vector to +the surface if you prefer being + + align:start position:0% +the surface if you prefer being + + + align:start position:0% +the surface if you prefer being +perpendicular to the surface means that + + align:start position:0% +perpendicular to the surface means that + + + align:start position:0% +perpendicular to the surface means that +you're perpendicular to its tangent + + align:start position:0% +you're perpendicular to its tangent + + + align:start position:0% +you're perpendicular to its tangent +plane + + align:start position:0% + + + + align:start position:0% + +okay so the + + align:start position:0% +okay so the + + + align:start position:0% +okay so the +equation is well + + align:start position:0% +equation is well + + + align:start position:0% +equation is well +4x + 2 + + align:start position:0% +4x + 2 + + + align:start position:0% +4x + 2 +y - 2 Z equals + + align:start position:0% +y - 2 Z equals + + + align:start position:0% +y - 2 Z equals +something where something is well we + + align:start position:0% +something where something is well we + + + align:start position:0% +something where something is well we +should just plug in that point we'll get + + align:start position:0% +should just plug in that point we'll get + + + align:start position:0% +should just plug in that point we'll get +8 + 2us 2 looks like we'll get + + align:start position:0% +8 + 2us 2 looks like we'll get + + + align:start position:0% +8 + 2us 2 looks like we'll get +eight and of course we could simplify by + + align:start position:0% +eight and of course we could simplify by + + + align:start position:0% +eight and of course we could simplify by +dividing everything by two two but it's + + align:start position:0% +dividing everything by two two but it's + + + align:start position:0% +dividing everything by two two but it's +not very important + + align:start position:0% +not very important + + + align:start position:0% +not very important +here okay so now if you have a surface + + align:start position:0% +here okay so now if you have a surface + + + align:start position:0% +here okay so now if you have a surface +given by an evil equation and a point on + + align:start position:0% +given by an evil equation and a point on + + + align:start position:0% +given by an evil equation and a point on +the surface well you know how to find + + align:start position:0% +the surface well you know how to find + + + align:start position:0% +the surface well you know how to find +the tangent plane to the surface at that + + align:start position:0% +the tangent plane to the surface at that + + + align:start position:0% +the tangent plane to the surface at that +point okay any + + align:start position:0% + + + + align:start position:0% + +questions + + align:start position:0% + + + + align:start position:0% + +no okay let me give just + + align:start position:0% +no okay let me give just + + + align:start position:0% +no okay let me give just +another reason why you know another way + + align:start position:0% +another reason why you know another way + + + align:start position:0% +another reason why you know another way +that we could have seen this + + align:start position:0% + + + + align:start position:0% + +so I claim in fact we could have done + + align:start position:0% +so I claim in fact we could have done + + + align:start position:0% +so I claim in fact we could have done +this without the gradient when using the + + align:start position:0% +this without the gradient when using the + + + align:start position:0% +this without the gradient when using the +gradient in somehow a disguised way so + + align:start position:0% +gradient in somehow a disguised way so + + + align:start position:0% +gradient in somehow a disguised way so +here's another + + align:start position:0% + + + + align:start position:0% + +way so the other way to do it would be + + align:start position:0% +way so the other way to do it would be + + + align:start position:0% +way so the other way to do it would be +to start with a + + align:start position:0% +to start with a + + + align:start position:0% +to start with a +differential okay DW well it's pretty + + align:start position:0% +differential okay DW well it's pretty + + + align:start position:0% +differential okay DW well it's pretty +much the same content but let me write + + align:start position:0% +much the same content but let me write + + + align:start position:0% +much the same content but let me write +it as a differential DW is 2x DX minus 2 + + align:start position:0% +it as a differential DW is 2x DX minus 2 + + + align:start position:0% +it as a differential DW is 2x DX minus 2 +y sorry plus 2 y d y minus 2 Z DZ so at + + align:start position:0% +y sorry plus 2 y d y minus 2 Z DZ so at + + + align:start position:0% +y sorry plus 2 y d y minus 2 Z DZ so at +the given + + align:start position:0% + + + + align:start position:0% + +point at 211 this is 4 DX + + + align:start position:0% +point at 211 this is 4 DX + + + + align:start position:0% +point at 211 this is 4 DX + +2dy minus 2 + + align:start position:0% +2dy minus 2 + + + align:start position:0% +2dy minus 2 +DZ now if we want to change this into an + + align:start position:0% +DZ now if we want to change this into an + + + align:start position:0% +DZ now if we want to change this into an +approximation formula we can we know + + align:start position:0% +approximation formula we can we know + + + align:start position:0% +approximation formula we can we know +that the change in w + + align:start position:0% + + + + align:start position:0% + +is approximately equal to 4 Delta X plus + + align:start position:0% +is approximately equal to 4 Delta X plus + + + align:start position:0% +is approximately equal to 4 Delta X plus +2 Delta + + align:start position:0% +2 Delta + + + align:start position:0% +2 Delta +Yus 2 Delta + + align:start position:0% +Yus 2 Delta + + + align:start position:0% +Yus 2 Delta +Z + + align:start position:0% +Z + + + align:start position:0% +Z +okay so when do we stay on the level + + align:start position:0% +okay so when do we stay on the level + + + align:start position:0% +okay so when do we stay on the level +surface well we stay on the level + + align:start position:0% +surface well we stay on the level + + + align:start position:0% +surface well we stay on the level +surface when w doesn't change so when + + align:start position:0% +surface when w doesn't change so when + + + align:start position:0% +surface when w doesn't change so when +this becomes + + align:start position:0% +this becomes + + + align:start position:0% +this becomes +zero okay now what does this + + align:start position:0% +zero okay now what does this + + + align:start position:0% +zero okay now what does this +approximation sign mean well it means + + align:start position:0% +approximation sign mean well it means + + + align:start position:0% +approximation sign mean well it means +that for small changes in XYZ this guy + + align:start position:0% +that for small changes in XYZ this guy + + + align:start position:0% +that for small changes in XYZ this guy +will be close to that guy it also means + + align:start position:0% +will be close to that guy it also means + + + align:start position:0% +will be close to that guy it also means +something else remember these + + align:start position:0% +something else remember these + + + align:start position:0% +something else remember these +approximation formulas they are linear + + align:start position:0% +approximation formulas they are linear + + + align:start position:0% +approximation formulas they are linear +approximation they mean that we replace + + align:start position:0% +approximation they mean that we replace + + + align:start position:0% +approximation they mean that we replace +the function actually by some closest + + align:start position:0% +the function actually by some closest + + + align:start position:0% +the function actually by some closest +linear formula that will be nearby and + + align:start position:0% +linear formula that will be nearby and + + + align:start position:0% +linear formula that will be nearby and +so in + + align:start position:0% +so in + + + align:start position:0% +so in +particular if we set face equal to zero + + align:start position:0% +particular if we set face equal to zero + + + align:start position:0% +particular if we set face equal to zero +instead of you know approximately zero + + align:start position:0% +instead of you know approximately zero + + + align:start position:0% +instead of you know approximately zero +it means we'll actually be moving on the + + align:start position:0% +it means we'll actually be moving on the + + + align:start position:0% +it means we'll actually be moving on the +tangent plane to the level set if you + + align:start position:0% +tangent plane to the level set if you + + + align:start position:0% +tangent plane to the level set if you +want setting equality is in + + align:start position:0% +want setting equality is in + + + align:start position:0% +want setting equality is in +approximations means that we replace the + + align:start position:0% +approximations means that we replace the + + + align:start position:0% +approximations means that we replace the +function by its tangent + + align:start position:0% + + + + align:start position:0% + +approximation + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +[Applause] + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +so the level corresponds + + align:start position:0% +so the level corresponds + + + align:start position:0% +so the level corresponds +to Delta W equal 0 and its tensent + + align:start position:0% + + + + align:start position:0% + +plane corresponds + + align:start position:0% +plane corresponds + + + align:start position:0% +plane corresponds +to + + align:start position:0% +to + + + align:start position:0% +to +4 Delta x + 2 Delta Yus 2 Delta Z equal + + align:start position:0% +4 Delta x + 2 Delta Yus 2 Delta Z equal + + + align:start position:0% +4 Delta x + 2 Delta Yus 2 Delta Z equal +Z that's what I'm trying to say + + align:start position:0% +Z that's what I'm trying to say + + + align:start position:0% +Z that's what I'm trying to say +basically and what's Delta X well that + + align:start position:0% +basically and what's Delta X well that + + + align:start position:0% +basically and what's Delta X well that +means it's the change in X so what's the + + align:start position:0% +means it's the change in X so what's the + + + align:start position:0% +means it's the change in X so what's the +change in X here that means well we + + align:start position:0% +change in X here that means well we + + + align:start position:0% +change in X here that means well we +started with xal 2 and we moved to some + + align:start position:0% +started with xal 2 and we moved to some + + + align:start position:0% +started with xal 2 and we moved to some +other value X so that's actually xus + + align:start position:0% +other value X so that's actually xus + + + align:start position:0% +other value X so that's actually xus +2 right that's how much X has changed + + align:start position:0% +2 right that's how much X has changed + + + align:start position:0% +2 right that's how much X has changed +compared to two and 2 * y - 1 - 2 * Z -1 + + align:start position:0% +compared to two and 2 * y - 1 - 2 * Z -1 + + + align:start position:0% +compared to two and 2 * y - 1 - 2 * Z -1 += 0 that's the equation of the tangent + + align:start position:0% + + + + align:start position:0% + +plane it's the same equation as the one + + align:start position:0% +plane it's the same equation as the one + + + align:start position:0% +plane it's the same equation as the one +over there these are just two different + + align:start position:0% +over there these are just two different + + + align:start position:0% +over there these are just two different +methods to get it okay so this one + + align:start position:0% +methods to get it okay so this one + + + align:start position:0% +methods to get it okay so this one +explains to you what's going on in terms + + align:start position:0% +explains to you what's going on in terms + + + align:start position:0% +explains to you what's going on in terms +of approximation formulas this one goes + + align:start position:0% +of approximation formulas this one goes + + + align:start position:0% +of approximation formulas this one goes +you know right away to the end by using + + align:start position:0% +you know right away to the end by using + + + align:start position:0% +you know right away to the end by using +the gradient + + align:start position:0% +the gradient + + + align:start position:0% +the gradient +Vector so in a way with this one you + + align:start position:0% +Vector so in a way with this one you + + + align:start position:0% +Vector so in a way with this one you +have you don't have to think nearly as + + align:start position:0% +have you don't have to think nearly as + + + align:start position:0% +have you don't have to think nearly as +much but you can use either + + align:start position:0% + + + + align:start position:0% + +one okay + + align:start position:0% + + + + align:start position:0% + +questions no okay so let's move on with + + align:start position:0% +questions no okay so let's move on with + + + align:start position:0% +questions no okay so let's move on with +let's move on to a new + + align:start position:0% +let's move on to a new + + + align:start position:0% +let's move on to a new +topic which is another application of a + + align:start position:0% +topic which is another application of a + + + align:start position:0% +topic which is another application of a +gradient + + align:start position:0% + + + + align:start position:0% + +vector + + align:start position:0% +vector + + + align:start position:0% +vector +and that is directional + + align:start position:0% + + + + align:start position:0% + +derivatives okay so let's say that we + + align:start position:0% +derivatives okay so let's say that we + + + align:start position:0% +derivatives okay so let's say that we +have a function of two + + align:start position:0% +have a function of two + + + align:start position:0% +have a function of two +variables X and + + align:start position:0% +variables X and + + + align:start position:0% +variables X and +Y well we + + align:start position:0% +Y well we + + + align:start position:0% +Y well we +know how to compute partial W partial X + + align:start position:0% +know how to compute partial W partial X + + + align:start position:0% +know how to compute partial W partial X +or partial W partial Y which which + + align:start position:0% +or partial W partial Y which which + + + align:start position:0% +or partial W partial Y which which +measure how W changes if I move in the + + align:start position:0% +measure how W changes if I move in the + + + align:start position:0% +measure how W changes if I move in the +direction of the x-axis or in the + + align:start position:0% +direction of the x-axis or in the + + + align:start position:0% +direction of the x-axis or in the +direction of the y + + align:start position:0% +direction of the y + + + align:start position:0% +direction of the y +axis so what about moving in other + + align:start position:0% +axis so what about moving in other + + + align:start position:0% +axis so what about moving in other +directions well of course we've seen + + align:start position:0% +directions well of course we've seen + + + align:start position:0% +directions well of course we've seen +approximation formulas and so on but you + + align:start position:0% +approximation formulas and so on but you + + + align:start position:0% +approximation formulas and so on but you +know we can still ask is there a + + align:start position:0% +know we can still ask is there a + + + align:start position:0% +know we can still ask is there a +derivative in every direction and that's + + align:start position:0% +derivative in every direction and that's + + + align:start position:0% +derivative in every direction and that's +basically yes that's the directional + + align:start position:0% +basically yes that's the directional + + + align:start position:0% +basically yes that's the directional +derivative okay so these are derivatives + + align:start position:0% + + + + align:start position:0% + +in the + + align:start position:0% + + + + align:start position:0% + +direction of I hat or J hat the vectors + + align:start position:0% +direction of I hat or J hat the vectors + + + align:start position:0% +direction of I hat or J hat the vectors +that go along the x or the y- + + align:start position:0% +that go along the x or the y- + + + align:start position:0% +that go along the x or the y- +axis + + align:start position:0% + + + + align:start position:0% + +so what if we + + align:start position:0% +so what if we + + + align:start position:0% +so what if we +move in another Direction let's say in + + align:start position:0% +move in another Direction let's say in + + + align:start position:0% +move in another Direction let's say in +the + + align:start position:0% +the + + + align:start position:0% +the +direction of some unit + + align:start position:0% +direction of some unit + + + align:start position:0% +direction of some unit +vector + + align:start position:0% +vector + + + align:start position:0% +vector +let's call it + + align:start position:0% + + + + align:start position:0% + +U okay so if I give you a unit Vector + + align:start position:0% +U okay so if I give you a unit Vector + + + align:start position:0% +U okay so if I give you a unit Vector +you can ask yourself if I move in that + + align:start position:0% +you can ask yourself if I move in that + + + align:start position:0% +you can ask yourself if I move in that +direction how quickly will my function + + align:start position:0% +direction how quickly will my function + + + align:start position:0% +direction how quickly will my function +change + + align:start position:0% + + + + align:start position:0% + +so so let's look at the straight + + align:start position:0% +so so let's look at the straight + + + align:start position:0% +so so let's look at the straight +trajectory what what this should mean is + + align:start position:0% +trajectory what what this should mean is + + + align:start position:0% +trajectory what what this should mean is +I start at some value + + align:start position:0% +I start at some value + + + align:start position:0% +I start at some value +XY and there I have my Vector U and I'm + + align:start position:0% +XY and there I have my Vector U and I'm + + + align:start position:0% +XY and there I have my Vector U and I'm +going to move in a straight line in the + + align:start position:0% +going to move in a straight line in the + + + align:start position:0% +going to move in a straight line in the +direction of U and I have the graph of + + align:start position:0% +direction of U and I have the graph of + + + align:start position:0% +direction of U and I have the graph of +my + + align:start position:0% + + + + align:start position:0% + +function and I'm asking myself how + + align:start position:0% +function and I'm asking myself how + + + align:start position:0% +function and I'm asking myself how +quickly does the value change when I + + align:start position:0% +quickly does the value change when I + + + align:start position:0% +quickly does the value change when I +move on the + + align:start position:0% +move on the + + + align:start position:0% +move on the +graph you know in that direction + + align:start position:0% + + + + align:start position:0% + +okay so let's look at a straight line + + align:start position:0% + + + + align:start position:0% + +trajectory so we have a position Vector + + align:start position:0% +trajectory so we have a position Vector + + + align:start position:0% +trajectory so we have a position Vector +r that will depend on some parameter + + align:start position:0% +r that will depend on some parameter + + + align:start position:0% +r that will depend on some parameter +which I will call S um you'll see why + + align:start position:0% +which I will call S um you'll see why + + + align:start position:0% +which I will call S um you'll see why +very soon in such a way that the + + align:start position:0% +very soon in such a way that the + + + align:start position:0% +very soon in such a way that the +derivative is this given unit Vector you + + align:start position:0% +derivative is this given unit Vector you + + + align:start position:0% +derivative is this given unit Vector you +had so why do I use S for my parameter + + align:start position:0% +had so why do I use S for my parameter + + + align:start position:0% +had so why do I use S for my parameter +rather than T well it's a convention I'm + + align:start position:0% +rather than T well it's a convention I'm + + + align:start position:0% +rather than T well it's a convention I'm +M I'm moving at I'm moving at unit speed + + align:start position:0% +M I'm moving at I'm moving at unit speed + + + align:start position:0% +M I'm moving at I'm moving at unit speed +along this line so that means that + + align:start position:0% +along this line so that means that + + + align:start position:0% +along this line so that means that +actually I'm parameterizing things by + + align:start position:0% +actually I'm parameterizing things by + + + align:start position:0% +actually I'm parameterizing things by +the distance that I've traveled along + + align:start position:0% +the distance that I've traveled along + + + align:start position:0% +the distance that I've traveled along +the curve sorry along this line so here + + align:start position:0% +the curve sorry along this line so here + + + align:start position:0% +the curve sorry along this line so here +it's called s in the sense of you know + + align:start position:0% +it's called s in the sense of you know + + + align:start position:0% +it's called s in the sense of you know +Arc Length or actually it's not really + + align:start position:0% +Arc Length or actually it's not really + + + align:start position:0% +Arc Length or actually it's not really +an arc because it's straight line so + + align:start position:0% +an arc because it's straight line so + + + align:start position:0% +an arc because it's straight line so +it's the + + align:start position:0% +it's the + + + align:start position:0% +it's the +distance + + align:start position:0% +distance + + + align:start position:0% +distance +along the + + align:start position:0% +along the + + + align:start position:0% +along the +line okay so because we parameterizing + + align:start position:0% +line okay so because we parameterizing + + + align:start position:0% +line okay so because we parameterizing +by distance we're just using S as a + + align:start position:0% +by distance we're just using S as a + + + align:start position:0% +by distance we're just using S as a +convention just to distinguish it + + align:start position:0% +convention just to distinguish it + + + align:start position:0% +convention just to distinguish it +with distinguish this from other + + align:start position:0% +with distinguish this from other + + + align:start position:0% +with distinguish this from other +situations and so now the question will + + align:start position:0% +situations and so now the question will + + + align:start position:0% +situations and so now the question will +be what + + align:start position:0% +be what + + + align:start position:0% +be what +is dwds + + align:start position:0% +is dwds + + + align:start position:0% +is dwds +what's the rate of change of w when I + + align:start position:0% +what's the rate of change of w when I + + + align:start position:0% +what's the rate of change of w when I +move like + + align:start position:0% +move like + + + align:start position:0% +move like +that well of course we know the answer + + align:start position:0% +that well of course we know the answer + + + align:start position:0% +that well of course we know the answer +because that's a special case of a chain + + align:start position:0% +because that's a special case of a chain + + + align:start position:0% +because that's a special case of a chain +rle so that's how we will actually + + align:start position:0% +rle so that's how we will actually + + + align:start position:0% +rle so that's how we will actually +compute + + align:start position:0% +compute + + + align:start position:0% +compute +it but in terms of what it means it + + align:start position:0% +it but in terms of what it means it + + + align:start position:0% +it but in terms of what it means it +really means we are asking ourselves we + + align:start position:0% +really means we are asking ourselves we + + + align:start position:0% +really means we are asking ourselves we +start at a point and we change the + + align:start position:0% +start at a point and we change the + + + align:start position:0% +start at a point and we change the +variables in a certain direction which + + align:start position:0% +variables in a certain direction which + + + align:start position:0% +variables in a certain direction which +is not necessarily the x or the Y + + align:start position:0% +is not necessarily the x or the Y + + + align:start position:0% +is not necessarily the x or the Y +Direction but really any Direction and + + align:start position:0% +Direction but really any Direction and + + + align:start position:0% +Direction but really any Direction and +then what's the derivative in that + + align:start position:0% +then what's the derivative in that + + + align:start position:0% +then what's the derivative in that +direction okay does that make sense as a + + align:start position:0% +direction okay does that make sense as a + + + align:start position:0% +direction okay does that make sense as a +concept kind of I see some faces that + + align:start position:0% +concept kind of I see some faces that + + + align:start position:0% +concept kind of I see some faces that +are not completely convinced so maybe I + + align:start position:0% +are not completely convinced so maybe I + + + align:start position:0% +are not completely convinced so maybe I +should show more pictures well let me + + align:start position:0% +should show more pictures well let me + + + align:start position:0% +should show more pictures well let me +first write down a bit more + + align:start position:0% + + + + align:start position:0% + +and I'll show you + + align:start position:0% + + + + align:start position:0% + +something + + align:start position:0% + + + + align:start position:0% + +so I just want to give you the actual + + align:start position:0% +so I just want to give you the actual + + + align:start position:0% +so I just want to give you the actual +definition so sorry so first of all in + + align:start position:0% +definition so sorry so first of all in + + + align:start position:0% +definition so sorry so first of all in +case you wonder what this is all + + align:start position:0% +case you wonder what this is all + + + align:start position:0% +case you wonder what this is all +about so let's say that the components + + align:start position:0% +about so let's say that the components + + + align:start position:0% +about so let's say that the components +of our unit Vector are two numbers A and + + align:start position:0% +of our unit Vector are two numbers A and + + + align:start position:0% +of our unit Vector are two numbers A and +B okay then it means that we'll move + + align:start position:0% +B okay then it means that we'll move + + + align:start position:0% +B okay then it means that we'll move +along the line X of s equals some + + align:start position:0% +along the line X of s equals some + + + align:start position:0% +along the line X of s equals some +initial value the point where we're + + align:start position:0% +initial value the point where we're + + + align:start position:0% +initial value the point where we're +actually looking at the directional + + align:start position:0% +actually looking at the directional + + + align:start position:0% +actually looking at the directional +derivative plus s * + + align:start position:0% +derivative plus s * + + + align:start position:0% +derivative plus s * +a we say plus a * + + align:start position:0% +a we say plus a * + + + align:start position:0% +a we say plus a * +s and Y of s equal y0 + B * s and then + + align:start position:0% +s and Y of s equal y0 + B * s and then + + + align:start position:0% +s and Y of s equal y0 + B * s and then +we plug that into + + align:start position:0% + + + + align:start position:0% + +w + + align:start position:0% + + + + align:start position:0% + +and then we take the + + align:start position:0% + + + + align:start position:0% + +derivative so we have a notation for + + align:start position:0% + + + + align:start position:0% + +that which is going to be + + align:start position:0% +that which is going to be + + + align:start position:0% +that which is going to be +dwds with a + + align:start position:0% +dwds with a + + + align:start position:0% +dwds with a +subscript in the direction of U to + + align:start position:0% +subscript in the direction of U to + + + align:start position:0% +subscript in the direction of U to +indicate you know in which direction + + align:start position:0% +indicate you know in which direction + + + align:start position:0% +indicate you know in which direction +we're actually going to + + align:start position:0% + + + + align:start position:0% + +move and that's called that's the + + align:start position:0% +move and that's called that's the + + + align:start position:0% +move and that's called that's the +directional + + align:start position:0% + + + + align:start position:0% + +derivative in the direction of + + align:start position:0% + + + + align:start position:0% + +U okay so let's see what it means + + align:start position:0% + + + + align:start position:0% + +geometrically + + align:start position:0% +geometrically + + + align:start position:0% +geometrically +oops + + align:start position:0% +oops + + + align:start position:0% +oops +um so + + align:start position:0% +um so + + + align:start position:0% +um so +so + + align:start position:0% +so + + + align:start position:0% +so +remember we've seen things about partial + + align:start position:0% +remember we've seen things about partial + + + align:start position:0% +remember we've seen things about partial +derivatives and we've seen that the + + align:start position:0% +derivatives and we've seen that the + + + align:start position:0% +derivatives and we've seen that the +partial derivatives are the slopes of + + align:start position:0% +partial derivatives are the slopes of + + + align:start position:0% +partial derivatives are the slopes of +slices of the graph by vertical planes + + align:start position:0% +slices of the graph by vertical planes + + + align:start position:0% +slices of the graph by vertical planes +that are parallel to the x or the Y + + align:start position:0% +that are parallel to the x or the Y + + + align:start position:0% +that are parallel to the x or the Y +directions okay so if I have a point you + + align:start position:0% +directions okay so if I have a point you + + + align:start position:0% +directions okay so if I have a point you +know at any point I can slice the graph + + align:start position:0% +know at any point I can slice the graph + + + align:start position:0% +know at any point I can slice the graph +of my function by two planes one that's + + align:start position:0% +of my function by two planes one that's + + + align:start position:0% +of my function by two planes one that's +going along the X One along the y + + align:start position:0% +going along the X One along the y + + + align:start position:0% +going along the X One along the y +direction and then I can look at + + align:start position:0% +direction and then I can look at + + + align:start position:0% +direction and then I can look at +the slices of the graph let me see if I + + align:start position:0% +the slices of the graph let me see if I + + + align:start position:0% +the slices of the graph let me see if I +can use that thing so we can look at the + + align:start position:0% +can use that thing so we can look at the + + + align:start position:0% +can use that thing so we can look at the +slices of the graph they drawn here and + + align:start position:0% +slices of the graph they drawn here and + + + align:start position:0% +slices of the graph they drawn here and +then we look at the tangent lines to + + align:start position:0% +then we look at the tangent lines to + + + align:start position:0% +then we look at the tangent lines to +these slices and we look at their slope + + align:start position:0% +these slices and we look at their slope + + + align:start position:0% +these slices and we look at their slope +and that gives us the partial + + align:start position:0% +and that gives us the partial + + + align:start position:0% +and that gives us the partial +derivatives in case you're on that side + + align:start position:0% +derivatives in case you're on that side + + + align:start position:0% +derivatives in case you're on that side +you want to see also the pointer was + + align:start position:0% +you want to see also the pointer was + + + align:start position:0% +you want to see also the pointer was +here + + align:start position:0% +here + + + align:start position:0% +here +okay so now similarly the directional + + align:start position:0% +okay so now similarly the directional + + + align:start position:0% +okay so now similarly the directional +derivative means actually we'll be + + align:start position:0% +derivative means actually we'll be + + + align:start position:0% +derivative means actually we'll be +slicing + + align:start position:0% + + + + align:start position:0% + +we'll be slicing our graph by a vertical + + align:start position:0% +we'll be slicing our graph by a vertical + + + align:start position:0% +we'll be slicing our graph by a vertical +plane it's not really colorful something + + align:start position:0% +plane it's not really colorful something + + + align:start position:0% +plane it's not really colorful something +more + + align:start position:0% +more + + + align:start position:0% +more +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +colorful we'll be slicing things by a + + align:start position:0% +colorful we'll be slicing things by a + + + align:start position:0% +colorful we'll be slicing things by a +plane that is now in the direction of + + align:start position:0% +plane that is now in the direction of + + + align:start position:0% +plane that is now in the direction of +this Vector U and we'll be looking at + + align:start position:0% +this Vector U and we'll be looking at + + + align:start position:0% +this Vector U and we'll be looking at +the slope of the slice of the graph so + + align:start position:0% +the slope of the slice of the graph so + + + align:start position:0% +the slope of the slice of the graph so +what that looks like + + align:start position:0% +what that looks like + + + align:start position:0% +what that looks like +here + + align:start position:0% +here + + + align:start position:0% +here +so so that's the same applet by the way + + align:start position:0% +so so that's the same applet by the way + + + align:start position:0% +so so that's the same applet by the way +that you've used on your problem set in + + align:start position:0% +that you've used on your problem set in + + + align:start position:0% +that you've used on your problem set in +case you're + + align:start position:0% +case you're + + + align:start position:0% +case you're +wondering so now I'm picking a + + align:start position:0% +wondering so now I'm picking a + + + align:start position:0% +wondering so now I'm picking a +point on the Contour plot and at that + + align:start position:0% +point on the Contour plot and at that + + + align:start position:0% +point on the Contour plot and at that +point I slice the graph so here I'm + + align:start position:0% +point I slice the graph so here I'm + + + align:start position:0% +point I slice the graph so here I'm +starting by slicing in the direction of + + align:start position:0% +starting by slicing in the direction of + + + align:start position:0% +starting by slicing in the direction of +the xaxis so in fact what I'm measuring + + align:start position:0% +the xaxis so in fact what I'm measuring + + + align:start position:0% +the xaxis so in fact what I'm measuring +here by the slope of this slice is the + + align:start position:0% +here by the slope of this slice is the + + + align:start position:0% +here by the slope of this slice is the +partial in the X Direction it's really + + align:start position:0% +partial in the X Direction it's really + + + align:start position:0% +partial in the X Direction it's really +partial F partial X which is also the + + align:start position:0% +partial F partial X which is also the + + + align:start position:0% +partial F partial X which is also the +directional derivative in the direction + + align:start position:0% +directional derivative in the direction + + + align:start position:0% +directional derivative in the direction +of X of I sorry and now if I rotate the + + align:start position:0% +of X of I sorry and now if I rotate the + + + align:start position:0% +of X of I sorry and now if I rotate the +slice then I have all of these planes so + + align:start position:0% +slice then I have all of these planes so + + + align:start position:0% +slice then I have all of these planes so +you see at the bottom left I have the + + align:start position:0% +you see at the bottom left I have the + + + align:start position:0% +you see at the bottom left I have the +direction in which I'm going there's + + align:start position:0% +direction in which I'm going there's + + + align:start position:0% +direction in which I'm going there's +this like rotating line that tells you + + align:start position:0% +this like rotating line that tells you + + + align:start position:0% +this like rotating line that tells you +in which direction I'm going to be + + align:start position:0% +in which direction I'm going to be + + + align:start position:0% +in which direction I'm going to be +moving and for each Direction I have a + + align:start position:0% +moving and for each Direction I have a + + + align:start position:0% +moving and for each Direction I have a +plane and when I slice by that plane I + + align:start position:0% +plane and when I slice by that plane I + + + align:start position:0% +plane and when I slice by that plane I +will get so I have this direction here + + align:start position:0% +will get so I have this direction here + + + align:start position:0% +will get so I have this direction here +going maybe to the Southwest so that + + align:start position:0% +going maybe to the Southwest so that + + + align:start position:0% +going maybe to the Southwest so that +gives me a slice of My Graph by a + + align:start position:0% +gives me a slice of My Graph by a + + + align:start position:0% +gives me a slice of My Graph by a +vertical plane and the slice has a + + align:start position:0% +vertical plane and the slice has a + + + align:start position:0% +vertical plane and the slice has a +certain slope and the slope is going to + + align:start position:0% +certain slope and the slope is going to + + + align:start position:0% +certain slope and the slope is going to +be the directional derivative in that + + align:start position:0% +be the directional derivative in that + + + align:start position:0% +be the directional derivative in that +direction + + align:start position:0% +direction + + + align:start position:0% +direction +okay I think that's as graphic as I can + + align:start position:0% + + + + align:start position:0% + +get + + align:start position:0% +get + + + align:start position:0% +get +okay any questions about + + align:start position:0% +okay any questions about + + + align:start position:0% +okay any questions about +that + + align:start position:0% +that + + + align:start position:0% +that +no okay so let's see how we compute that + + align:start position:0% +no okay so let's see how we compute that + + + align:start position:0% +no okay so let's see how we compute that +guy + + align:start position:0% + + + + align:start position:0% + +so let me just wrp again just in case + + align:start position:0% +so let me just wrp again just in case + + + align:start position:0% +so let me just wrp again just in case +you want + + align:start position:0% + + + + align:start position:0% + +to case you didn't hear me it's the + + align:start position:0% +to case you didn't hear me it's the + + + align:start position:0% +to case you didn't hear me it's the +slope of the slice of the + + align:start position:0% +slope of the slice of the + + + align:start position:0% +slope of the slice of the +graph by a vertical + + align:start position:0% +graph by a vertical + + + align:start position:0% +graph by a vertical +plane + + align:start position:0% + + + + align:start position:0% + +that contains the given Direction U + + align:start position:0% +that contains the given Direction U + + + align:start position:0% +that contains the given Direction U +that's parallel to the direction + + align:start position:0% +that's parallel to the direction + + + align:start position:0% +that's parallel to the direction +U so how do we compute it well we can + + align:start position:0% +U so how do we compute it well we can + + + align:start position:0% +U so how do we compute it well we can +use the chain rule the chain + + align:start position:0% +use the chain rule the chain + + + align:start position:0% +use the chain rule the chain +rule + + align:start position:0% + + + + align:start position:0% + +implies that DW + + align:start position:0% +implies that DW + + + align:start position:0% +implies that DW +DS is actually the gradient of w do + + align:start position:0% +DS is actually the gradient of w do + + + align:start position:0% +DS is actually the gradient of w do +product + + align:start position:0% +product + + + align:start position:0% +product +with + + align:start position:0% +with + + + align:start position:0% +with +the velocity Vector drds but remember we + + align:start position:0% +the velocity Vector drds but remember we + + + align:start position:0% +the velocity Vector drds but remember we +said that we are going to be moving at + + align:start position:0% +said that we are going to be moving at + + + align:start position:0% +said that we are going to be moving at +unit speed in the direction of U so in + + align:start position:0% +unit speed in the direction of U so in + + + align:start position:0% +unit speed in the direction of U so in +fact that's just gradient W do product + + align:start position:0% +fact that's just gradient W do product + + + align:start position:0% +fact that's just gradient W do product +with the unit Vector + + align:start position:0% + + + + align:start position:0% + +U okay so the formula that we remember + + align:start position:0% +U okay so the formula that we remember + + + align:start position:0% +U okay so the formula that we remember +is + + align:start position:0% +is + + + align:start position:0% +is +really d by DS in the direction of U is + + align:start position:0% +really d by DS in the direction of U is + + + align:start position:0% +really d by DS in the direction of U is +gradient W product with + + align:start position:0% +gradient W product with + + + align:start position:0% +gradient W product with +you and maybe I should also say in words + + align:start position:0% +you and maybe I should also say in words + + + align:start position:0% +you and maybe I should also say in words +this is the + + align:start position:0% + + + + align:start position:0% + +component of the gradient in the + + align:start position:0% + + + + align:start position:0% + +direction of + + align:start position:0% +direction of + + + align:start position:0% +direction of +U and maybe that makes more sense so for + + align:start position:0% +U and maybe that makes more sense so for + + + align:start position:0% +U and maybe that makes more sense so for +example the directional derivative in + + align:start position:0% +example the directional derivative in + + + align:start position:0% +example the directional derivative in +the direction of IH hat is the component + + align:start position:0% +the direction of IH hat is the component + + + align:start position:0% +the direction of IH hat is the component +along the xaxis that's the same as + + align:start position:0% +along the xaxis that's the same as + + + align:start position:0% +along the xaxis that's the same as +indeed the partial derivative in the X + + align:start position:0% +indeed the partial derivative in the X + + + align:start position:0% +indeed the partial derivative in the X +Direction things make + + align:start position:0% + + + + align:start position:0% + +sense dwds the direction of IH hat + + align:start position:0% +sense dwds the direction of IH hat + + + align:start position:0% +sense dwds the direction of IH hat +is oh sorry what am I + + align:start position:0% +is oh sorry what am I + + + align:start position:0% +is oh sorry what am I +doing radi w. I hat which is W subx + + align:start position:0% +doing radi w. I hat which is W subx + + + align:start position:0% +doing radi w. I hat which is W subx +maybe I should find partial W partial X + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +now so that's basically what we need to + + align:start position:0% +now so that's basically what we need to + + + align:start position:0% +now so that's basically what we need to +know to compute these + + align:start position:0% +know to compute these + + + align:start position:0% +know to compute these +guys so now let's go back to the + + align:start position:0% +guys so now let's go back to the + + + align:start position:0% +guys so now let's go back to the +gradient and see what this tells us + + align:start position:0% +gradient and see what this tells us + + + align:start position:0% +gradient and see what this tells us +about the + + align:start position:0% + + + + align:start position:0% + +gradient + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +I see you guys are having + + align:start position:0% +I see you guys are having + + + align:start position:0% +I see you guys are having +fun + + align:start position:0% + + + + align:start position:0% + +okay okay let's do a little bit of + + align:start position:0% +okay okay let's do a little bit of + + + align:start position:0% +okay okay let's do a little bit of +geometry + + align:start position:0% +geometry + + + align:start position:0% +geometry +here that should calm you + + align:start position:0% +here that should calm you + + + align:start position:0% +here that should calm you +down so + + align:start position:0% +down so + + + align:start position:0% +down so +so we said dwds in the direction of U is + + align:start position:0% +so we said dwds in the direction of U is + + + align:start position:0% +so we said dwds in the direction of U is +gradient w. U that's the same as the + + align:start position:0% +gradient w. U that's the same as the + + + align:start position:0% +gradient w. U that's the same as the +length of gradient W Times the length of + + align:start position:0% +length of gradient W Times the length of + + + align:start position:0% +length of gradient W Times the length of +U well that happens to be one because + + align:start position:0% +U well that happens to be one because + + + align:start position:0% +U well that happens to be one because +we're taking a unit Vector times the + + align:start position:0% +we're taking a unit Vector times the + + + align:start position:0% +we're taking a unit Vector times the +cosine of the + + align:start position:0% +cosine of the + + + align:start position:0% +cosine of the +angle between the + + align:start position:0% + + + + align:start position:0% + +gradient and the given unit vector + + align:start position:0% + + + + align:start position:0% + +U so have this angle + + align:start position:0% +U so have this angle + + + align:start position:0% +U so have this angle +feta okay that's another way of saying + + align:start position:0% +feta okay that's another way of saying + + + align:start position:0% +feta okay that's another way of saying +we're taking the component of the + + align:start position:0% +we're taking the component of the + + + align:start position:0% +we're taking the component of the +gradient in the direction of U but now + + align:start position:0% +gradient in the direction of U but now + + + align:start position:0% +gradient in the direction of U but now +what does that tell us well let's try to + + align:start position:0% +what does that tell us well let's try to + + + align:start position:0% +what does that tell us well let's try to +figure out in which directions W changes + + align:start position:0% +figure out in which directions W changes + + + align:start position:0% +figure out in which directions W changes +the fastest in which direction it + + align:start position:0% +the fastest in which direction it + + + align:start position:0% +the fastest in which direction it +increases the most or decreases the most + + align:start position:0% +increases the most or decreases the most + + + align:start position:0% +increases the most or decreases the most +or doesn't actually + + align:start position:0% +or doesn't actually + + + align:start position:0% +or doesn't actually +change so this is when is this going to + + align:start position:0% +change so this is when is this going to + + + align:start position:0% +change so this is when is this going to +be the largest if I fix you if I fix a + + align:start position:0% +be the largest if I fix you if I fix a + + + align:start position:0% +be the largest if I fix you if I fix a +point if I set a point then the gradient + + align:start position:0% +point if I set a point then the gradient + + + align:start position:0% +point if I set a point then the gradient +Vector at that point is given to me but + + align:start position:0% +Vector at that point is given to me but + + + align:start position:0% +Vector at that point is given to me but +question is in which direction does it + + align:start position:0% +question is in which direction does it + + + align:start position:0% +question is in which direction does it +change the most quickly well what I can + + align:start position:0% +change the most quickly well what I can + + + align:start position:0% +change the most quickly well what I can +change is the direction and this will be + + align:start position:0% +change is the direction and this will be + + + align:start position:0% +change is the direction and this will be +the largest when the cosine is + + align:start position:0% +the largest when the cosine is + + + align:start position:0% +the largest when the cosine is +one so this is larest when cosine of the + + align:start position:0% +one so this is larest when cosine of the + + + align:start position:0% +one so this is larest when cosine of the +angle is one + + align:start position:0% +angle is one + + + align:start position:0% +angle is one +that means the angle is + + align:start position:0% +that means the angle is + + + align:start position:0% +that means the angle is +zero that means U is actually in the + + align:start position:0% +zero that means U is actually in the + + + align:start position:0% +zero that means U is actually in the +direction of the + + align:start position:0% +direction of the + + + align:start position:0% +direction of the +gradient okay so that's a new way to + + align:start position:0% +gradient okay so that's a new way to + + + align:start position:0% +gradient okay so that's a new way to +think about the direction of the + + align:start position:0% +think about the direction of the + + + align:start position:0% +think about the direction of the +gradient the gradient is the direction + + align:start position:0% +gradient the gradient is the direction + + + align:start position:0% +gradient the gradient is the direction +in which the function increases the most + + align:start position:0% +in which the function increases the most + + + align:start position:0% +in which the function increases the most +quickly at that + + align:start position:0% + + + + align:start position:0% + +point + + align:start position:0% +point + + + align:start position:0% +point +so the + + align:start position:0% +so the + + + align:start position:0% +so the +direction of gradient W is the + + align:start position:0% +direction of gradient W is the + + + align:start position:0% +direction of gradient W is the +direction of fastest + + align:start position:0% + + + + align:start position:0% + +increase of w at the given point and + + align:start position:0% +increase of w at the given point and + + + align:start position:0% +increase of w at the given point and +what is the + + align:start position:0% +what is the + + + align:start position:0% +what is the +magnitude of w well it's actually the + + align:start position:0% +magnitude of w well it's actually the + + + align:start position:0% +magnitude of w well it's actually the +directional derivative in that + + align:start position:0% + + + + align:start position:0% + +direction + + align:start position:0% + + + + align:start position:0% + +okay so if I go in that direction which + + align:start position:0% +okay so if I go in that direction which + + + align:start position:0% +okay so if I go in that direction which +gives me the fastest increase then the + + align:start position:0% +gives me the fastest increase then the + + + align:start position:0% +gives me the fastest increase then the +corresponding slope will be the length + + align:start position:0% +corresponding slope will be the length + + + align:start position:0% +corresponding slope will be the length +of the + + align:start position:0% + + + + align:start position:0% + +gradient + + align:start position:0% + + + + align:start position:0% + +and what's the direction of fastest + + align:start position:0% +and what's the direction of fastest + + + align:start position:0% +and what's the direction of fastest +decrease it's going in the opposite + + align:start position:0% +decrease it's going in the opposite + + + align:start position:0% +decrease it's going in the opposite +direction right I mean if you're a + + align:start position:0% +direction right I mean if you're a + + + align:start position:0% +direction right I mean if you're a +mountain and you know that you're facing + + align:start position:0% +mountain and you know that you're facing + + + align:start position:0% +mountain and you know that you're facing +the mountain uh that's the direction of + + align:start position:0% +the mountain uh that's the direction of + + + align:start position:0% +the mountain uh that's the direction of +fastest increase the direction of + + align:start position:0% +fastest increase the direction of + + + align:start position:0% +fastest increase the direction of +fastest decrease is behind you straight + + align:start position:0% +fastest decrease is behind you straight + + + align:start position:0% +fastest decrease is behind you straight +down okay + + align:start position:0% +down okay + + + align:start position:0% +down okay +so uh the minimal value of + + align:start position:0% + + + + align:start position:0% + +dwds is achieved when cosine of theta is + + align:start position:0% +dwds is achieved when cosine of theta is + + + align:start position:0% +dwds is achieved when cosine of theta is +minus one that means Theta equal + + align:start position:0% +minus one that means Theta equal + + + align:start position:0% +minus one that means Theta equal +180° that means U is in the + + align:start position:0% +180° that means U is in the + + + align:start position:0% +180° that means U is in the +direction of minus the + + align:start position:0% +direction of minus the + + + align:start position:0% +direction of minus the +gradient head points opposite to the + + align:start position:0% +gradient head points opposite to the + + + align:start position:0% +gradient head points opposite to the +gradient + + align:start position:0% +gradient + + + align:start position:0% +gradient +and + + align:start position:0% +and + + + align:start position:0% +and +finally + + align:start position:0% +finally + + + align:start position:0% +finally +when do we have + + align:start position:0% +when do we have + + + align:start position:0% +when do we have +dwds equal + + align:start position:0% + + + + align:start position:0% + +zero so in which direction does the + + align:start position:0% +zero so in which direction does the + + + align:start position:0% +zero so in which direction does the +function not + + align:start position:0% +function not + + + align:start position:0% +function not +change well we have two answers to that + + align:start position:0% +change well we have two answers to that + + + align:start position:0% +change well we have two answers to that +one is to just use that formula so + + align:start position:0% +one is to just use that formula so + + + align:start position:0% +one is to just use that formula so +that's when cosine Theta equal 0 that + + align:start position:0% +that's when cosine Theta equal 0 that + + + align:start position:0% +that's when cosine Theta equal 0 that +means Theta equal + + align:start position:0% +means Theta equal + + + align:start position:0% +means Theta equal +90° that means that U is perpendicular + + align:start position:0% +90° that means that U is perpendicular + + + align:start position:0% +90° that means that U is perpendicular +to the + + align:start position:0% +to the + + + align:start position:0% +to the +gradient the other way to think about it + + align:start position:0% +gradient the other way to think about it + + + align:start position:0% +gradient the other way to think about it +a direction in which the value doesn't + + align:start position:0% +a direction in which the value doesn't + + + align:start position:0% +a direction in which the value doesn't +change is a Direction that's tangent to + + align:start position:0% +change is a Direction that's tangent to + + + align:start position:0% +change is a Direction that's tangent to +the level surface if we're not changing + + align:start position:0% +the level surface if we're not changing + + + align:start position:0% +the level surface if we're not changing +it means we're moving along the + + align:start position:0% +it means we're moving along the + + + align:start position:0% +it means we're moving along the +level and that's the same + + align:start position:0% + + + + align:start position:0% + +thing + + align:start position:0% +thing + + + align:start position:0% +thing +as being tangent to the level so let me + + align:start position:0% +as being tangent to the level so let me + + + align:start position:0% +as being tangent to the level so let me +just show that on the picture + + align:start position:0% +just show that on the picture + + + align:start position:0% +just show that on the picture +here so if I actually show you the + + align:start position:0% +here so if I actually show you the + + + align:start position:0% +here so if I actually show you the +gradient uh you can't really see it here + + align:start position:0% +gradient uh you can't really see it here + + + align:start position:0% +gradient uh you can't really see it here +I need to move a bit okay so the + + align:start position:0% +I need to move a bit okay so the + + + align:start position:0% +I need to move a bit okay so the +gradient here is pointing straight up at + + align:start position:0% +gradient here is pointing straight up at + + + align:start position:0% +gradient here is pointing straight up at +the point that I've chosen now if I + + align:start position:0% +the point that I've chosen now if I + + + align:start position:0% +the point that I've chosen now if I +choose a slice that's + + align:start position:0% +choose a slice that's + + + align:start position:0% +choose a slice that's +perpendicular you know in a Direction + + align:start position:0% +perpendicular you know in a Direction + + + align:start position:0% +perpendicular you know in a Direction +that's perpendicular to the gradient so + + align:start position:0% +that's perpendicular to the gradient so + + + align:start position:0% +that's perpendicular to the gradient so +that's actually tangent to the level + + align:start position:0% +that's actually tangent to the level + + + align:start position:0% +that's actually tangent to the level +curve then you see that my slice is flat + + align:start position:0% +curve then you see that my slice is flat + + + align:start position:0% +curve then you see that my slice is flat +I don't actually have any slope the + + align:start position:0% +I don't actually have any slope the + + + align:start position:0% +I don't actually have any slope the +directional derivative in a Direction + + align:start position:0% +directional derivative in a Direction + + + align:start position:0% +directional derivative in a Direction +that's perpendicular to the gradient is + + align:start position:0% +that's perpendicular to the gradient is + + + align:start position:0% +that's perpendicular to the gradient is +basically + + align:start position:0% +basically + + + align:start position:0% +basically +zero now if I rotate then the slope + + align:start position:0% +zero now if I rotate then the slope + + + align:start position:0% +zero now if I rotate then the slope +slowly increases increases increases and + + align:start position:0% +slowly increases increases increases and + + + align:start position:0% +slowly increases increases increases and +it becomes the largest when I'm going in + + align:start position:0% +it becomes the largest when I'm going in + + + align:start position:0% +it becomes the largest when I'm going in +the direction of the gradient so here I + + align:start position:0% +the direction of the gradient so here I + + + align:start position:0% +the direction of the gradient so here I +have actually a pretty big slope and now + + align:start position:0% +have actually a pretty big slope and now + + + align:start position:0% +have actually a pretty big slope and now +if I keep rotating then the slope will + + align:start position:0% +if I keep rotating then the slope will + + + align:start position:0% +if I keep rotating then the slope will +decrease again then it becomes zero when + + align:start position:0% +decrease again then it becomes zero when + + + align:start position:0% +decrease again then it becomes zero when +I'm perpendicular and then it becomes + + align:start position:0% +I'm perpendicular and then it becomes + + + align:start position:0% +I'm perpendicular and then it becomes +negative it's the most negative when I'm + + align:start position:0% +negative it's the most negative when I'm + + + align:start position:0% +negative it's the most negative when I'm +point away from the gradient and then + + align:start position:0% +point away from the gradient and then + + + align:start position:0% +point away from the gradient and then +become zero again when I'm back + + align:start position:0% +become zero again when I'm back + + + align:start position:0% +become zero again when I'm back +perpendicular okay so for example if I + + align:start position:0% +perpendicular okay so for example if I + + + align:start position:0% +perpendicular okay so for example if I +give you a contour plot and I ask you to + + align:start position:0% +give you a contour plot and I ask you to + + + align:start position:0% +give you a contour plot and I ask you to +draw the direction of the gradient + + align:start position:0% +draw the direction of the gradient + + + align:start position:0% +draw the direction of the gradient +Vector well at this point for example + + align:start position:0% +Vector well at this point for example + + + align:start position:0% +Vector well at this point for example +you would look at the picture the + + align:start position:0% +you would look at the picture the + + + align:start position:0% +you would look at the picture the +gradient Vector would be going + + align:start position:0% +gradient Vector would be going + + + align:start position:0% +gradient Vector would be going +perpendicular to the level and it would + + align:start position:0% +perpendicular to the level and it would + + + align:start position:0% +perpendicular to the level and it would +be going towards higher values of the + + align:start position:0% +be going towards higher values of the + + + align:start position:0% +be going towards higher values of the +function and I don't know if you can see + + align:start position:0% +function and I don't know if you can see + + + align:start position:0% +function and I don't know if you can see +the labels but the thing in the middle + + align:start position:0% +the labels but the thing in the middle + + + align:start position:0% +the labels but the thing in the middle +is minimum so it would actually be + + align:start position:0% +is minimum so it would actually be + + + align:start position:0% +is minimum so it would actually be +pointing in this kind of + + align:start position:0% + + + + align:start position:0% + +Direction okay so that's it for + + align:start position:0% +Direction okay so that's it for + + + align:start position:0% +Direction okay so that's it for +today \ No newline at end of file diff --git a/2__KumJsGXc.txt b/2__KumJsGXc.txt new file mode 100644 index 0000000000000000000000000000000000000000..5ce964811c20d9b0c9647152b1585a5b14f33fe0 --- /dev/null +++ b/2__KumJsGXc.txt @@ -0,0 +1,435 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit MIT opencourseware + + align:start position:0% +of MIT courses visit MIT opencourseware + + + align:start position:0% +of MIT courses visit MIT opencourseware +at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu we + + align:start position:0% +ocw.mit.edu we + + + align:start position:0% +ocw.mit.edu we +have this definition for the class + + align:start position:0% +have this definition for the class + + + align:start position:0% +have this definition for the class +object I've + + align:start position:0% +object I've + + + align:start position:0% +object I've +um I've created the init for you and + + align:start position:0% +um I've created the init for you and + + + align:start position:0% +um I've created the init for you and +here I'm giving itself which is the + + align:start position:0% +here I'm giving itself which is the + + + align:start position:0% +here I'm giving itself which is the +first thing that you have to give it and + + align:start position:0% +first thing that you have to give it and + + + align:start position:0% +first thing that you have to give it and +then two parameters W and + + align:start position:0% +then two parameters W and + + + align:start position:0% +then two parameters W and +d and for for an instance of a car I'm + + align:start position:0% +d and for for an instance of a car I'm + + + align:start position:0% +d and for for an instance of a car I'm +going to assign the data attribute named + + align:start position:0% +going to assign the data attribute named + + + align:start position:0% +going to assign the data attribute named +Wheels to whatever is passed in for w so + + align:start position:0% +Wheels to whatever is passed in for w so + + + align:start position:0% +Wheels to whatever is passed in for w so +notice that they're not the same name + + align:start position:0% +notice that they're not the same name + + + align:start position:0% +notice that they're not the same name +and the data attribute for doors is + + align:start position:0% +and the data attribute for doors is + + + align:start position:0% +and the data attribute for doors is +going to be the value that's passed in + + align:start position:0% +going to be the value that's passed in + + + align:start position:0% +going to be the value that's passed in +for D okay and also notice that inside + + align:start position:0% +for D okay and also notice that inside + + + align:start position:0% +for D okay and also notice that inside +the init I can do any other sort of + + align:start position:0% +the init I can do any other sort of + + + align:start position:0% +the init I can do any other sort of +initializations that I'd like so it's + + align:start position:0% +initializations that I'd like so it's + + + align:start position:0% +initializations that I'd like so it's +not just assigning variables from the + + align:start position:0% +not just assigning variables from the + + + align:start position:0% +not just assigning variables from the +parameters to local to um to variables + + align:start position:0% +parameters to local to um to variables + + + align:start position:0% +parameters to local to um to variables +for for my objects so in this case I'm + + align:start position:0% +for for my objects so in this case I'm + + + align:start position:0% +for for my objects so in this case I'm +ass I'm creating a new data attribute + + align:start position:0% +ass I'm creating a new data attribute + + + align:start position:0% +ass I'm creating a new data attribute +named color and I'm going to just create + + align:start position:0% +named color and I'm going to just create + + + align:start position:0% +named color and I'm going to just create +it to be an empty string okay notice + + align:start position:0% +it to be an empty string okay notice + + + align:start position:0% +it to be an empty string okay notice +because I didn't even even though I + + align:start position:0% +because I didn't even even though I + + + align:start position:0% +because I didn't even even though I +didn't pass in any color to my uh to my + + align:start position:0% +didn't pass in any color to my uh to my + + + align:start position:0% +didn't pass in any color to my uh to my +object so the question says using the + + align:start position:0% +object so the question says using the + + + align:start position:0% +object so the question says using the +class definition above which line + + align:start position:0% +class definition above which line + + + align:start position:0% +class definition above which line +creates a new car object with four + + align:start position:0% +creates a new car object with four + + + align:start position:0% +creates a new car object with four +wheels and two doors okay so this + + align:start position:0% +wheels and two doors okay so this + + + align:start position:0% +wheels and two doors okay so this +um this first + + align:start position:0% +um this first + + + align:start position:0% +um this first +one is not right because it's trying to + + align:start position:0% +one is not right because it's trying to + + + align:start position:0% +one is not right because it's trying to +call the class with a variable my car so + + align:start position:0% +call the class with a variable my car so + + + align:start position:0% +call the class with a variable my car so +for self which isn't quite right so when + + align:start position:0% +for self which isn't quite right so when + + + align:start position:0% +for self which isn't quite right so when +you're creating a when you're creating + + align:start position:0% +you're creating a when you're creating + + + align:start position:0% +you're creating a when you're creating +your object you have to give it one less + + align:start position:0% +your object you have to give it one less + + + align:start position:0% +your object you have to give it one less +parameter than what you have so here + + align:start position:0% +parameter than what you have so here + + + align:start position:0% +parameter than what you have so here +we're just going to have to create it + + align:start position:0% +we're just going to have to create it + + + align:start position:0% +we're just going to have to create it +with the w and the + + align:start position:0% +with the w and the + + + align:start position:0% +with the w and the +D so we're going to create this + + align:start position:0% +D so we're going to create this + + + align:start position:0% +D so we're going to create this +the these variable this variable my car + + align:start position:0% +the these variable this variable my car + + + align:start position:0% +the these variable this variable my car +and we're going to assign it four for + + align:start position:0% +and we're going to assign it four for + + + align:start position:0% +and we're going to assign it four for +the number of uh wheels and two for the + + align:start position:0% +the number of uh wheels and two for the + + + align:start position:0% +the number of uh wheels and two for the +number of doors and the number of Wheels + + align:start position:0% +number of doors and the number of Wheels + + + align:start position:0% +number of doors and the number of Wheels +is the first parameter and the number of + + align:start position:0% +is the first parameter and the number of + + + align:start position:0% +is the first parameter and the number of +doors is the second one so it should be + + align:start position:0% +doors is the second one so it should be + + + align:start position:0% +doors is the second one so it should be +this one here car 4 comma 2 so that's + + align:start position:0% +this one here car 4 comma 2 so that's + + + align:start position:0% +this one here car 4 comma 2 so that's +this one + + align:start position:0% +this one + + + align:start position:0% +this one +perfect \ No newline at end of file diff --git a/2guwjwIHmGg.txt b/2guwjwIHmGg.txt new file mode 100644 index 0000000000000000000000000000000000000000..4b2f71439cfbfdf93820927cb016ab6d34710080 --- /dev/null +++ b/2guwjwIHmGg.txt @@ -0,0 +1,1011 @@ +align:start position:0% + +when we used our energy principle + + align:start position:0% +when we used our energy principle + + + align:start position:0% +when we used our energy principle +suppose we have an object that starts at + + align:start position:0% +suppose we have an object that starts at + + + align:start position:0% +suppose we have an object that starts at +a height H naught and this object is + + align:start position:0% +a height H naught and this object is + + + align:start position:0% +a height H naught and this object is +dropped and when it gets to the ground + + align:start position:0% +dropped and when it gets to the ground + + + align:start position:0% +dropped and when it gets to the ground +it has some final velocity and when we + + align:start position:0% +it has some final velocity and when we + + + align:start position:0% +it has some final velocity and when we +applied our energy principle assuming + + align:start position:0% +applied our energy principle assuming + + + align:start position:0% +applied our energy principle assuming +that there was no air resistance what we + + align:start position:0% +that there was no air resistance what we + + + align:start position:0% +that there was no air resistance what we +saw was that the change in kinetic + + align:start position:0% +saw was that the change in kinetic + + + align:start position:0% +saw was that the change in kinetic +energy plus the change a potential + + align:start position:0% +energy plus the change a potential + + + align:start position:0% +energy plus the change a potential +energy was zero so we had zero was equal + + align:start position:0% +energy was zero so we had zero was equal + + + align:start position:0% +energy was zero so we had zero was equal +to Delta K plus Delta U and we saw that + + align:start position:0% +to Delta K plus Delta U and we saw that + + + align:start position:0% +to Delta K plus Delta U and we saw that +the kinetic energy changed by one-half + + align:start position:0% +the kinetic energy changed by one-half + + + align:start position:0% +the kinetic energy changed by one-half +MV squared and the potential energy + + align:start position:0% +MV squared and the potential energy + + + align:start position:0% +MV squared and the potential energy +changed by minus MGH not so we can + + align:start position:0% +changed by minus MGH not so we can + + + align:start position:0% +changed by minus MGH not so we can +compute the velocity of the object as + + align:start position:0% +compute the velocity of the object as + + + align:start position:0% +compute the velocity of the object as +its falling given by square root of 2gh + + align:start position:0% +its falling given by square root of 2gh + + + align:start position:0% +its falling given by square root of 2gh +not now now that we're considering + + align:start position:0% +not now now that we're considering + + + align:start position:0% +not now now that we're considering +kinetic energy of rotation + + align:start position:0% +kinetic energy of rotation + + + align:start position:0% +kinetic energy of rotation +recall that we showed that the kinetic + + align:start position:0% +recall that we showed that the kinetic + + + align:start position:0% +recall that we showed that the kinetic +energy of rotate of a pure rotation + + align:start position:0% +energy of rotate of a pure rotation + + + align:start position:0% +energy of rotate of a pure rotation +about a fixed axis was one-half the + + align:start position:0% +about a fixed axis was one-half the + + + align:start position:0% +about a fixed axis was one-half the +moment of inertia about that axis times + + align:start position:0% +moment of inertia about that axis times + + + align:start position:0% +moment of inertia about that axis times +the angular speed squared we now would + + align:start position:0% +the angular speed squared we now would + + + align:start position:0% +the angular speed squared we now would +like to apply our energy principle to + + align:start position:0% +like to apply our energy principle to + + + align:start position:0% +like to apply our energy principle to +include rotational kinetic energy along + + align:start position:0% +include rotational kinetic energy along + + + align:start position:0% +include rotational kinetic energy along +with the translational kinetic energy + + align:start position:0% +with the translational kinetic energy + + + align:start position:0% +with the translational kinetic energy +and the example that we want to look at + + align:start position:0% +and the example that we want to look at + + + align:start position:0% +and the example that we want to look at +is something very simple suppose we have + + align:start position:0% +is something very simple suppose we have + + + align:start position:0% +is something very simple suppose we have +a pulley + + align:start position:0% +a pulley + + + align:start position:0% +a pulley +now our pulley has a mass P and we'll + + align:start position:0% +now our pulley has a mass P and we'll + + + align:start position:0% +now our pulley has a mass P and we'll +say it has a moment of inertia of the + + align:start position:0% +say it has a moment of inertia of the + + + align:start position:0% +say it has a moment of inertia of the +pulley about the fixed axis passing + + align:start position:0% +pulley about the fixed axis passing + + + align:start position:0% +pulley about the fixed axis passing +through the center of the pulley and we + + align:start position:0% +through the center of the pulley and we + + + align:start position:0% +through the center of the pulley and we +have a mass one and another block two + + align:start position:0% +have a mass one and another block two + + + align:start position:0% +have a mass one and another block two +and let's suppose that we release this + + align:start position:0% +and let's suppose that we release this + + + align:start position:0% +and let's suppose that we release this +system and for the moment let's make + + align:start position:0% +system and for the moment let's make + + + align:start position:0% +system and for the moment let's make +this surface frictionless and suppose + + align:start position:0% +this surface frictionless and suppose + + + align:start position:0% +this surface frictionless and suppose +that block two falls down a certain + + align:start position:0% +that block two falls down a certain + + + align:start position:0% +that block two falls down a certain +distance so in the final state block two + + align:start position:0% +distance so in the final state block two + + + align:start position:0% +distance so in the final state block two +will have dropped the distance H final + + align:start position:0% +will have dropped the distance H final + + + align:start position:0% +will have dropped the distance H final +from + + align:start position:0% +from + + + align:start position:0% +from +it's initial position and what we'd like + + align:start position:0% +it's initial position and what we'd like + + + align:start position:0% +it's initial position and what we'd like +to consider is find the velocity final + + align:start position:0% +to consider is find the velocity final + + + align:start position:0% +to consider is find the velocity final +of block two so we begin in the same way + + align:start position:0% +of block two so we begin in the same way + + + align:start position:0% +of block two so we begin in the same way +that we've done this before by + + align:start position:0% +that we've done this before by + + + align:start position:0% +that we've done this before by +considering our energy diagrams and so + + align:start position:0% +considering our energy diagrams and so + + + align:start position:0% +considering our energy diagrams and so +we'll have an initial state and in our + + align:start position:0% +we'll have an initial state and in our + + + align:start position:0% +we'll have an initial state and in our +initial state what we'll do is we'll + + align:start position:0% +initial state what we'll do is we'll + + + align:start position:0% +initial state what we'll do is we'll +just have the initial one two and I'm + + align:start position:0% +just have the initial one two and I'm + + + align:start position:0% +just have the initial one two and I'm +going to choose u equals zero here's my + + align:start position:0% +going to choose u equals zero here's my + + + align:start position:0% +going to choose u equals zero here's my +pulley and everything is at rest and so + + align:start position:0% +pulley and everything is at rest and so + + + align:start position:0% +pulley and everything is at rest and so +in the initial state the initial energy + + align:start position:0% +in the initial state the initial energy + + + align:start position:0% +in the initial state the initial energy +initial K initial plus u initial is zero + + align:start position:0% +initial K initial plus u initial is zero + + + align:start position:0% +initial K initial plus u initial is zero +and in our final state we have the + + align:start position:0% +and in our final state we have the + + + align:start position:0% +and in our final state we have the +pulley is rotating with Omega final + + align:start position:0% +pulley is rotating with Omega final + + + align:start position:0% +pulley is rotating with Omega final +block one is moving with the velocity V + + align:start position:0% +block one is moving with the velocity V + + + align:start position:0% +block one is moving with the velocity V +final one and block two is also moving + + align:start position:0% +final one and block two is also moving + + + align:start position:0% +final one and block two is also moving +with v2 final and let's just suppose + + align:start position:0% +with v2 final and let's just suppose + + + align:start position:0% +with v2 final and let's just suppose +that this was our u equals zero position + + align:start position:0% +that this was our u equals zero position + + + align:start position:0% +that this was our u equals zero position +and although it's so clear on the + + align:start position:0% +and although it's so clear on the + + + align:start position:0% +and although it's so clear on the +diagram u final it has moved down height + + align:start position:0% +diagram u final it has moved down height + + + align:start position:0% +diagram u final it has moved down height +H final so what is the energy in our + + align:start position:0% +H final so what is the energy in our + + + align:start position:0% +H final so what is the energy in our +final state well we have to consider all + + align:start position:0% +final state well we have to consider all + + + align:start position:0% +final state well we have to consider all +the different pieces we have block one + + align:start position:0% +the different pieces we have block one + + + align:start position:0% +the different pieces we have block one +one-half m1 v1 final squared we have the + + align:start position:0% +one-half m1 v1 final squared we have the + + + align:start position:0% +one-half m1 v1 final squared we have the +motion of block 2 one-half m2 v2 final + + align:start position:0% +motion of block 2 one-half m2 v2 final + + + align:start position:0% +motion of block 2 one-half m2 v2 final +squared and we also have the kinetic + + align:start position:0% +squared and we also have the kinetic + + + align:start position:0% +squared and we also have the kinetic +energy of the pulley which is given by + + align:start position:0% +energy of the pulley which is given by + + + align:start position:0% +energy of the pulley which is given by +1/2 I about the pulley Omega final + + align:start position:0% +1/2 I about the pulley Omega final + + + align:start position:0% +1/2 I about the pulley Omega final +square and what about our final + + align:start position:0% +square and what about our final + + + align:start position:0% +square and what about our final +potential energy well we dropped the + + align:start position:0% +potential energy well we dropped the + + + align:start position:0% +potential energy well we dropped the +height H final so we have block two has + + align:start position:0% +height H final so we have block two has + + + align:start position:0% +height H final so we have block two has +moved minus em 2 gee H final and now we + + align:start position:0% +moved minus em 2 gee H final and now we + + + align:start position:0% +moved minus em 2 gee H final and now we +have our two energy states + + align:start position:0% +have our two energy states + + + align:start position:0% +have our two energy states +and what we'd like to consider is apply + + align:start position:0% +and what we'd like to consider is apply + + + align:start position:0% +and what we'd like to consider is apply +the energy principle just like we + + align:start position:0% +the energy principle just like we + + + align:start position:0% +the energy principle just like we +applied it for this simple case but + + align:start position:0% +applied it for this simple case but + + + align:start position:0% +applied it for this simple case but +before we do that there is a constraint + + align:start position:0% +before we do that there is a constraint + + + align:start position:0% +before we do that there is a constraint +condition that because the Rope is fixed + + align:start position:0% + + + + align:start position:0% + +in length as block one moves the pulley + + align:start position:0% +in length as block one moves the pulley + + + align:start position:0% +in length as block one moves the pulley +is rotating and block 2 is moving what + + align:start position:0% +is rotating and block 2 is moving what + + + align:start position:0% +is rotating and block 2 is moving what +we'll have is fixed and not slipping so + + align:start position:0% +we'll have is fixed and not slipping so + + + align:start position:0% +we'll have is fixed and not slipping so +as the Rope moves around the pulley the + + align:start position:0% +as the Rope moves around the pulley the + + + align:start position:0% +as the Rope moves around the pulley the +pulley is moving with the same motion is + + align:start position:0% +pulley is moving with the same motion is + + + align:start position:0% +pulley is moving with the same motion is +the rope and the Rope is moving with the + + align:start position:0% +the rope and the Rope is moving with the + + + align:start position:0% +the rope and the Rope is moving with the +speeds of block 1 and 2 so we see that V + + align:start position:0% +speeds of block 1 and 2 so we see that V + + + align:start position:0% +speeds of block 1 and 2 so we see that V +1 final is equal to B 2 final and now + + align:start position:0% +1 final is equal to B 2 final and now + + + align:start position:0% +1 final is equal to B 2 final and now +what about the pulley if this is radius + + align:start position:0% +what about the pulley if this is radius + + + align:start position:0% +what about the pulley if this is radius +R we know that the velocity of a point + + align:start position:0% +R we know that the velocity of a point + + + align:start position:0% +R we know that the velocity of a point +on the rim of a disc is moving with the + + align:start position:0% +on the rim of a disc is moving with the + + + align:start position:0% +on the rim of a disc is moving with the +speed of the rope which is the speed of + + align:start position:0% +speed of the rope which is the speed of + + + align:start position:0% +speed of the rope which is the speed of +block 1 and block 2 so that's our Omega + + align:start position:0% +block 1 and block 2 so that's our Omega + + + align:start position:0% +block 1 and block 2 so that's our Omega +final and so that makes our final energy + + align:start position:0% +final and so that makes our final energy + + + align:start position:0% +final and so that makes our final energy +that's now gather terms the velocities + + align:start position:0% +that's now gather terms the velocities + + + align:start position:0% +that's now gather terms the velocities +are the same so we have one-half m1 plus + + align:start position:0% +are the same so we have one-half m1 plus + + + align:start position:0% +are the same so we have one-half m1 plus +m2 and we'll just call this V final for + + align:start position:0% +m2 and we'll just call this V final for + + + align:start position:0% +m2 and we'll just call this V final for +simplicity one-half m2 times V final + + align:start position:0% +simplicity one-half m2 times V final + + + align:start position:0% +simplicity one-half m2 times V final +squared that accounts for these two + + align:start position:0% +squared that accounts for these two + + + align:start position:0% +squared that accounts for these two +terms and we have the moment of inertia + + align:start position:0% +terms and we have the moment of inertia + + + align:start position:0% +terms and we have the moment of inertia +kinetic energy associated with the wheel + + align:start position:0% +kinetic energy associated with the wheel + + + align:start position:0% +kinetic energy associated with the wheel +which is one-half I Omega final squared + + align:start position:0% +which is one-half I Omega final squared + + + align:start position:0% +which is one-half I Omega final squared +which is V final squared over R squared + + align:start position:0% +which is V final squared over R squared + + + align:start position:0% +which is V final squared over R squared +minus em 2 gee H final and so now we can + + align:start position:0% +minus em 2 gee H final and so now we can + + + align:start position:0% +minus em 2 gee H final and so now we can +solve our energy principle which is + + align:start position:0% +solve our energy principle which is + + + align:start position:0% +solve our energy principle which is +because we're assuming everything is + + align:start position:0% +because we're assuming everything is + + + align:start position:0% +because we're assuming everything is +frictionless we have 0 equals e final + + align:start position:0% +frictionless we have 0 equals e final + + + align:start position:0% +frictionless we have 0 equals e final +minus initial implies that a final + + align:start position:0% +minus initial implies that a final + + + align:start position:0% +minus initial implies that a final +equals the initial and we chose our + + align:start position:0% +equals the initial and we chose our + + + align:start position:0% +equals the initial and we chose our +initial potential energy to be zero so + + align:start position:0% +initial potential energy to be zero so + + + align:start position:0% +initial potential energy to be zero so +of course that's just a choice of + + align:start position:0% +of course that's just a choice of + + + align:start position:0% +of course that's just a choice of +constant so I can now solve this + + align:start position:0% +constant so I can now solve this + + + align:start position:0% +constant so I can now solve this +equation + + align:start position:0% +equation + + + align:start position:0% +equation +by setting a final equal to zero that's + + align:start position:0% +by setting a final equal to zero that's + + + align:start position:0% +by setting a final equal to zero that's +the same statement and then you can see + + align:start position:0% +the same statement and then you can see + + + align:start position:0% +the same statement and then you can see +algebraically I can solve for V final + + align:start position:0% +algebraically I can solve for V final + + + align:start position:0% +algebraically I can solve for V final +and what I get is I'm just going to + + align:start position:0% +and what I get is I'm just going to + + + align:start position:0% +and what I get is I'm just going to +write all these terms over I get em 2 + + align:start position:0% +write all these terms over I get em 2 + + + align:start position:0% +write all these terms over I get em 2 +gee H final I'm gonna divide by this + + align:start position:0% +gee H final I'm gonna divide by this + + + align:start position:0% +gee H final I'm gonna divide by this +common coefficient 1/2 + 1 + M 2 plus + + align:start position:0% +common coefficient 1/2 + 1 + M 2 plus + + + align:start position:0% +common coefficient 1/2 + 1 + M 2 plus +the moment of inertia divided by radius + + align:start position:0% +the moment of inertia divided by radius + + + align:start position:0% +the moment of inertia divided by radius +squared and I now have to take the + + align:start position:0% +squared and I now have to take the + + + align:start position:0% +squared and I now have to take the +square root of the whole thing and + + align:start position:0% +square root of the whole thing and + + + align:start position:0% +square root of the whole thing and +that's how I can find the velocity of + + align:start position:0% +that's how I can find the velocity of + + + align:start position:0% +that's how I can find the velocity of +block 2 when it's dropped down a certain + + align:start position:0% +block 2 when it's dropped down a certain + + + align:start position:0% +block 2 when it's dropped down a certain +distance H final so here we've + + align:start position:0% +distance H final so here we've + + + align:start position:0% +distance H final so here we've +generalized our energy approach to + + align:start position:0% +generalized our energy approach to + + + align:start position:0% +generalized our energy approach to +include rotational kinetic energy \ No newline at end of file diff --git a/2hNfJwfEvkA.txt b/2hNfJwfEvkA.txt new file mode 100644 index 0000000000000000000000000000000000000000..fb0754afbf68954fafa7a93df45436dc877a148a --- /dev/null +++ b/2hNfJwfEvkA.txt @@ -0,0 +1,15659 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +to view additional materials from + + align:start position:0% +to view additional materials from + + + align:start position:0% +to view additional materials from +hundreds of MIT courses visit MIT + + align:start position:0% +hundreds of MIT courses visit MIT + + + align:start position:0% +hundreds of MIT courses visit MIT +opencourseware at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu but let me mention again the + + align:start position:0% +ocw.mit.edu but let me mention again the + + + align:start position:0% +ocw.mit.edu but let me mention again the +tremendous importance uh of for for the + + align:start position:0% +tremendous importance uh of for for the + + + align:start position:0% +tremendous importance uh of for for the +for your understanding of the subject + + align:start position:0% +for your understanding of the subject + + + align:start position:0% +for your understanding of the subject +matter of the course uh of your watching + + align:start position:0% +matter of the course uh of your watching + + + align:start position:0% +matter of the course uh of your watching +as much television as possible not only + + align:start position:0% +as much television as possible not only + + + align:start position:0% +as much television as possible not only +the new prime time schedule that's about + + align:start position:0% +the new prime time schedule that's about + + + align:start position:0% +the new prime time schedule that's about +to start next week uh watch as much of + + align:start position:0% +to start next week uh watch as much of + + + align:start position:0% +to start next week uh watch as much of +it as you can make time for and we'll + + align:start position:0% +it as you can make time for and we'll + + + align:start position:0% +it as you can make time for and we'll +single out certain programs that I hope + + align:start position:0% +single out certain programs that I hope + + + align:start position:0% +single out certain programs that I hope +everyone will watch so we'll have some + + align:start position:0% +everyone will watch so we'll have some + + + align:start position:0% +everyone will watch so we'll have some +some uh shared experience of + + align:start position:0% +some uh shared experience of + + + align:start position:0% +some uh shared experience of +contemporary television that will uh + + align:start position:0% +contemporary television that will uh + + + align:start position:0% +contemporary television that will uh +create a kind of ballast for our + + align:start position:0% +create a kind of ballast for our + + + align:start position:0% +create a kind of ballast for our +argument and complicate our argument and + + align:start position:0% +argument and complicate our argument and + + + align:start position:0% +argument and complicate our argument and +allow us to draw on some common examples + + align:start position:0% +allow us to draw on some common examples + + + align:start position:0% +allow us to draw on some common examples +but even more important than that are + + align:start position:0% +but even more important than that are + + + align:start position:0% +but even more important than that are +the reruns that are on during the day on + + align:start position:0% +the reruns that are on during the day on + + + align:start position:0% +the reruns that are on during the day on +many channels and are especially + + align:start position:0% +many channels and are especially + + + align:start position:0% +many channels and are especially +available on Nick at night and TV Land + + align:start position:0% +available on Nick at night and TV Land + + + align:start position:0% +available on Nick at night and TV Land +and those of you who get who have access + + align:start position:0% +and those of you who get who have access + + + align:start position:0% +and those of you who get who have access +to Cable Systems should really watch + + align:start position:0% +to Cable Systems should really watch + + + align:start position:0% +to Cable Systems should really watch +those programs you can they they + + align:start position:0% +those programs you can they they + + + align:start position:0% +those programs you can they they +constitute over the course of a week or + + align:start position:0% +constitute over the course of a week or + + + align:start position:0% +constitute over the course of a week or +so a kind of mini history of the medium + + align:start position:0% +so a kind of mini history of the medium + + + align:start position:0% +so a kind of mini history of the medium +and we're going to be trying to + + align:start position:0% +and we're going to be trying to + + + align:start position:0% +and we're going to be trying to +construct a history of the medium that + + align:start position:0% +construct a history of the medium that + + + align:start position:0% +construct a history of the medium that +takes account of the external the + + align:start position:0% +takes account of the external the + + + align:start position:0% +takes account of the external the +political soci social forces that are + + align:start position:0% +political soci social forces that are + + + align:start position:0% +political soci social forces that are +shaping the medium but also take account + + align:start position:0% +shaping the medium but also take account + + + align:start position:0% +shaping the medium but also take account +of what we might call the internal + + align:start position:0% +of what we might call the internal + + + align:start position:0% +of what we might call the internal +Dynamic whereby a media system once it + + align:start position:0% +Dynamic whereby a media system once it + + + align:start position:0% +Dynamic whereby a media system once it +is stabilized in a society uh um uh + + align:start position:0% +is stabilized in a society uh um uh + + + align:start position:0% +is stabilized in a society uh um uh +elaborates itself and evolves in certain + + align:start position:0% +elaborates itself and evolves in certain + + + align:start position:0% +elaborates itself and evolves in certain +ways that I hope I can dramatize in a + + align:start position:0% +ways that I hope I can dramatize in a + + + align:start position:0% +ways that I hope I can dramatize in a +very in a very U credible and and and uh + + align:start position:0% +very in a very U credible and and and uh + + + align:start position:0% +very in a very U credible and and and uh +useful way for you as I suggested a few + + align:start position:0% +useful way for you as I suggested a few + + + align:start position:0% +useful way for you as I suggested a few +times in earlier classes one advantage + + align:start position:0% +times in earlier classes one advantage + + + align:start position:0% +times in earlier classes one advantage +of the perspective I try to suggest in + + align:start position:0% +of the perspective I try to suggest in + + + align:start position:0% +of the perspective I try to suggest in +this course is that it isn't limited to + + align:start position:0% +this course is that it isn't limited to + + + align:start position:0% +this course is that it isn't limited to +television that the that the framework + + align:start position:0% +television that the that the framework + + + align:start position:0% +television that the that the framework +theoretically I believe the framework + + align:start position:0% +theoretically I believe the framework + + + align:start position:0% +theoretically I believe the framework +could be used for virtually any media + + align:start position:0% +could be used for virtually any media + + + align:start position:0% +could be used for virtually any media +system with you have to be flexible and + + align:start position:0% +system with you have to be flexible and + + + align:start position:0% +system with you have to be flexible and +apply it in a flexible way but there's a + + align:start position:0% +apply it in a flexible way but there's a + + + align:start position:0% +apply it in a flexible way but there's a +process of of there's a process of what + + align:start position:0% +process of of there's a process of what + + + align:start position:0% +process of of there's a process of what +we might in a narrow in a in a in a + + align:start position:0% +we might in a narrow in a in a in a + + + align:start position:0% +we might in a narrow in a in a in a +broad sense called self-discovery + + align:start position:0% +broad sense called self-discovery + + + align:start position:0% +broad sense called self-discovery +wherein the new medium adapt to the + + align:start position:0% +wherein the new medium adapt to the + + + align:start position:0% +wherein the new medium adapt to the +particular economic and + + align:start position:0% +particular economic and + + + align:start position:0% +particular economic and +Technical and environmental constraints + + align:start position:0% +Technical and environmental constraints + + + align:start position:0% +Technical and environmental constraints +that it faces and also begins to explore + + align:start position:0% +that it faces and also begins to explore + + + align:start position:0% +that it faces and also begins to explore +the features and aspects of its nature + + align:start position:0% +the features and aspects of its nature + + + align:start position:0% +the features and aspects of its nature +that are unique to it what distinguishes + + align:start position:0% +that are unique to it what distinguishes + + + align:start position:0% +that are unique to it what distinguishes +it from its ancestors this exploration + + align:start position:0% +it from its ancestors this exploration + + + align:start position:0% +it from its ancestors this exploration +is always partial and + + align:start position:0% +is always partial and + + + align:start position:0% +is always partial and +incomplete a most dramatic example of + + align:start position:0% +incomplete a most dramatic example of + + + align:start position:0% +incomplete a most dramatic example of +that in the terms of the television + + align:start position:0% +that in the terms of the television + + + align:start position:0% +that in the terms of the television +medium is in some ways the most powerful + + align:start position:0% +medium is in some ways the most powerful + + + align:start position:0% +medium is in some ways the most powerful +and distinctive feature of television as + + align:start position:0% +and distinctive feature of television as + + + align:start position:0% +and distinctive feature of television as +a medium is a feature that was barely + + align:start position:0% +a medium is a feature that was barely + + + align:start position:0% +a medium is a feature that was barely +exploited by its fiction programming and + + align:start position:0% +exploited by its fiction programming and + + + align:start position:0% +exploited by its fiction programming and +really hasn't been much exploited uh by + + align:start position:0% +really hasn't been much exploited uh by + + + align:start position:0% +really hasn't been much exploited uh by +television by by by the medium more + + align:start position:0% +television by by by the medium more + + + align:start position:0% +television by by by the medium more +generally except in moments of Crisis + + align:start position:0% +generally except in moments of Crisis + + + align:start position:0% +generally except in moments of Crisis +and that is its power to allow to + + align:start position:0% +and that is its power to allow to + + + align:start position:0% +and that is its power to allow to +connect people all over the globe + + align:start position:0% +connect people all over the globe + + + align:start position:0% +connect people all over the globe +simultaneously to an event that's taking + + align:start position:0% +simultaneously to an event that's taking + + + align:start position:0% +simultaneously to an event that's taking +place now its power of simultaneous + + align:start position:0% +place now its power of simultaneous + + + align:start position:0% +place now its power of simultaneous +transmission uh in it's a very powerful + + align:start position:0% +transmission uh in it's a very powerful + + + align:start position:0% +transmission uh in it's a very powerful +and unique feature of Television no + + align:start position:0% +and unique feature of Television no + + + align:start position:0% +and unique feature of Television no +prior techn radio in some sense was + + align:start position:0% +prior techn radio in some sense was + + + align:start position:0% +prior techn radio in some sense was +capable of doing this but without + + align:start position:0% +capable of doing this but without + + + align:start position:0% +capable of doing this but without +pictures right uh uh but but that + + align:start position:0% +pictures right uh uh but but that + + + align:start position:0% +pictures right uh uh but but that +feature of Television was really not + + align:start position:0% +feature of Television was really not + + + align:start position:0% +feature of Television was really not +very much exploited and certainly not + + align:start position:0% +very much exploited and certainly not + + + align:start position:0% +very much exploited and certainly not +exploited at all in the fiction + + align:start position:0% +exploited at all in the fiction + + + align:start position:0% +exploited at all in the fiction +programming that developed which took + + align:start position:0% +programming that developed which took + + + align:start position:0% +programming that developed which took +place which were M programs were filmed + + align:start position:0% +place which were M programs were filmed + + + align:start position:0% +place which were M programs were filmed +and they and uh did not uh even attempt + + align:start position:0% +and they and uh did not uh even attempt + + + align:start position:0% +and they and uh did not uh even attempt +to exploit this this I'm not sure that + + align:start position:0% +to exploit this this I'm not sure that + + + align:start position:0% +to exploit this this I'm not sure that +as a that that it's a feature that is + + align:start position:0% +as a that that it's a feature that is + + + align:start position:0% +as a that that it's a feature that is +like likely to be of permanent and + + align:start position:0% +like likely to be of permanent and + + + align:start position:0% +like likely to be of permanent and +extensive use to fiction anyway to to + + align:start position:0% +extensive use to fiction anyway to to + + + align:start position:0% +extensive use to fiction anyway to to +narrative but it's certainly a feature + + align:start position:0% +narrative but it's certainly a feature + + + align:start position:0% +narrative but it's certainly a feature +of Television that in small ways is + + align:start position:0% +of Television that in small ways is + + + align:start position:0% +of Television that in small ways is +exploited every and of course we can + + align:start position:0% +exploited every and of course we can + + + align:start position:0% +exploited every and of course we can +feel uh the power of that that aspect + + align:start position:0% +feel uh the power of that that aspect + + + align:start position:0% +feel uh the power of that that aspect +the power of that aspect of the medium + + align:start position:0% +the power of that aspect of the medium + + + align:start position:0% +the power of that aspect of the medium +very strongly right now because of those + + align:start position:0% +very strongly right now because of those + + + align:start position:0% +very strongly right now because of those +uh images that we were able to see of of + + align:start position:0% +uh images that we were able to see of of + + + align:start position:0% +uh images that we were able to see of of +uh things going on in New York while it + + align:start position:0% +uh things going on in New York while it + + + align:start position:0% +uh things going on in New York while it +while it was happening uh but of course + + align:start position:0% +while it was happening uh but of course + + + align:start position:0% +while it was happening uh but of course +that's not its only Power and and it's + + align:start position:0% +that's not its only Power and and it's + + + align:start position:0% +that's not its only Power and and it's +its power to repeat and show things + + align:start position:0% +its power to repeat and show things + + + align:start position:0% +its power to repeat and show things +again and again is also an extraordinary + + align:start position:0% +again and again is also an extraordinary + + + align:start position:0% +again and again is also an extraordinary +aspect of of what it's in words its + + align:start position:0% +aspect of of what it's in words its + + + align:start position:0% +aspect of of what it's in words its +power both to record and preserve events + + align:start position:0% +power both to record and preserve events + + + align:start position:0% +power both to record and preserve events +and also to register events as they are + + align:start position:0% +and also to register events as they are + + + align:start position:0% +and also to register events as they are +happening uh that no medium has such a + + align:start position:0% +happening uh that no medium has such a + + + align:start position:0% +happening uh that no medium has such a +simultaneous power to do both at the + + align:start position:0% +simultaneous power to do both at the + + + align:start position:0% +simultaneous power to do both at the +same time and one can feel those the the + + align:start position:0% +same time and one can feel those the the + + + align:start position:0% +same time and one can feel those the the +the extraordinary uh importance and and + + align:start position:0% +the extraordinary uh importance and and + + + align:start position:0% +the extraordinary uh importance and and +uh extensiveness of those of those + + align:start position:0% +uh extensiveness of those of those + + + align:start position:0% +uh extensiveness of those of those +defining features of the medium in in + + align:start position:0% +defining features of the medium in in + + + align:start position:0% +defining features of the medium in in +what we've been watching on television + + align:start position:0% +what we've been watching on television + + + align:start position:0% +what we've been watching on television +over the past over the past week and + + align:start position:0% +over the past over the past week and + + + align:start position:0% +over the past over the past week and +more uh it's a reminder of of what what + + align:start position:0% +more uh it's a reminder of of what what + + + align:start position:0% +more uh it's a reminder of of what what +an uniquely significant and unique + + align:start position:0% +an uniquely significant and unique + + + align:start position:0% +an uniquely significant and unique +uniquely + + align:start position:0% +uniquely + + + align:start position:0% +uniquely +defining defi uniquely defining + + align:start position:0% +defining defi uniquely defining + + + align:start position:0% +defining defi uniquely defining +instrument uh television is for the + + align:start position:0% +instrument uh television is for the + + + align:start position:0% +instrument uh television is for the +modern age for the for the 20th and the + + align:start position:0% +modern age for the for the 20th and the + + + align:start position:0% +modern age for the for the 20th and the +21st century it's probably the + + align:start position:0% +21st century it's probably the + + + align:start position:0% +21st century it's probably the +distinctive technology of the second + + align:start position:0% +distinctive technology of the second + + + align:start position:0% +distinctive technology of the second +certainly the distinctive technology of + + align:start position:0% +certainly the distinctive technology of + + + align:start position:0% +certainly the distinctive technology of +the second half of the 20th century and + + align:start position:0% +the second half of the 20th century and + + + align:start position:0% +the second half of the 20th century and +continues to be a dominant will will + + align:start position:0% +continues to be a dominant will will + + + align:start position:0% +continues to be a dominant will will +continue to be a dominant technology in + + align:start position:0% +continue to be a dominant technology in + + + align:start position:0% +continue to be a dominant technology in +the new century um so to come back to my + + align:start position:0% +the new century um so to come back to my + + + align:start position:0% +the new century um so to come back to my +uh original idea the framework that I'm + + align:start position:0% +uh original idea the framework that I'm + + + align:start position:0% +uh original idea the framework that I'm +proposing in the course about the way + + align:start position:0% +proposing in the course about the way + + + align:start position:0% +proposing in the course about the way +television uh uh in in the United States + + align:start position:0% +television uh uh in in the United States + + + align:start position:0% +television uh uh in in the United States +evolved and developed uh is a framework + + align:start position:0% +evolved and developed uh is a framework + + + align:start position:0% +evolved and developed uh is a framework +for uh I hope uh is a framework with + + align:start position:0% +for uh I hope uh is a framework with + + + align:start position:0% +for uh I hope uh is a framework with +applications to other to other media + + align:start position:0% +applications to other to other media + + + align:start position:0% +applications to other to other media +histories and uh the truth is I think in + + align:start position:0% +histories and uh the truth is I think in + + + align:start position:0% +histories and uh the truth is I think in +fact that the basic framework would is + + align:start position:0% +fact that the basic framework would is + + + align:start position:0% +fact that the basic framework would is +probably useful even for such recent + + align:start position:0% +probably useful even for such recent + + + align:start position:0% +probably useful even for such recent +Technologies as the computer uh although + + align:start position:0% +Technologies as the computer uh although + + + align:start position:0% +Technologies as the computer uh although +it's much harder to see the various + + align:start position:0% +it's much harder to see the various + + + align:start position:0% +it's much harder to see the various +phases through which Computing uh the + + align:start position:0% +phases through which Computing uh the + + + align:start position:0% +phases through which Computing uh the +computer as an object is uh likely to uh + + align:start position:0% +computer as an object is uh likely to uh + + + align:start position:0% +computer as an object is uh likely to uh +uh evolve uh it's clear that in certain + + align:start position:0% +uh evolve uh it's clear that in certain + + + align:start position:0% +uh evolve uh it's clear that in certain +broad ways the the development of the + + align:start position:0% +broad ways the the development of the + + + align:start position:0% +broad ways the the development of the +computer resembles uh the way it's + + align:start position:0% +computer resembles uh the way it's + + + align:start position:0% +computer resembles uh the way it's +deployed in society and the way and the + + align:start position:0% +deployed in society and the way and the + + + align:start position:0% +deployed in society and the way and the +way it has been used by by by the + + align:start position:0% +way it has been used by by by the + + + align:start position:0% +way it has been used by by by the +culture resembles in certain respects + + align:start position:0% +culture resembles in certain respects + + + align:start position:0% +culture resembles in certain respects +the development of earlier media and + + align:start position:0% +the development of earlier media and + + + align:start position:0% +the development of earlier media and +it's very useful to know that just as + + align:start position:0% +it's very useful to know that just as + + + align:start position:0% +it's very useful to know that just as +the development of television in certain + + align:start position:0% +the development of television in certain + + + align:start position:0% +the development of television in certain +fundamental ways resembles the devel the + + align:start position:0% +fundamental ways resembles the devel the + + + align:start position:0% +fundamental ways resembles the devel the +evolution the development of American + + align:start position:0% +evolution the development of American + + + align:start position:0% +evolution the development of American +movies which in turn mirror although in + + align:start position:0% +movies which in turn mirror although in + + + align:start position:0% +movies which in turn mirror although in +a in a less decisively uh exact way the + + align:start position:0% +a in a less decisively uh exact way the + + + align:start position:0% +a in a less decisively uh exact way the +the uh process whereby earlier + + align:start position:0% +the uh process whereby earlier + + + align:start position:0% +the uh process whereby earlier +Technologies such as the printing press + + align:start position:0% +Technologies such as the printing press + + + align:start position:0% +Technologies such as the printing press +were absorbed into society and used by + + align:start position:0% +were absorbed into society and used by + + + align:start position:0% +were absorbed into society and used by +Society so the broad perspectives I + + align:start position:0% +Society so the broad perspectives I + + + align:start position:0% +Society so the broad perspectives I +think are useful beyond the question of + + align:start position:0% +think are useful beyond the question of + + + align:start position:0% +think are useful beyond the question of +Television but I + + align:start position:0% +Television but I + + + align:start position:0% +Television but I +hope in addition that that you'll come + + align:start position:0% +hope in addition that that you'll come + + + align:start position:0% +hope in addition that that you'll come +away from the course with a much more + + align:start position:0% +away from the course with a much more + + + align:start position:0% +away from the course with a much more +systematic and and uh nuanced structured + + align:start position:0% +systematic and and uh nuanced structured + + + align:start position:0% +systematic and and uh nuanced structured +um thick description uh of what uh + + align:start position:0% +um thick description uh of what uh + + + align:start position:0% +um thick description uh of what uh +American television is and has been and + + align:start position:0% +American television is and has been and + + + align:start position:0% +American television is and has been and +especially what it has what it has been + + align:start position:0% +especially what it has what it has been + + + align:start position:0% +especially what it has what it has been +so today is our last day without Clips + + align:start position:0% +so today is our last day without Clips + + + align:start position:0% +so today is our last day without Clips +but you might be thinking about some of + + align:start position:0% +but you might be thinking about some of + + + align:start position:0% +but you might be thinking about some of +the clips that you saw on Wednesday + + align:start position:0% +the clips that you saw on Wednesday + + + align:start position:0% +the clips that you saw on Wednesday +night uh uh to U complicate the things + + align:start position:0% +night uh uh to U complicate the things + + + align:start position:0% +night uh uh to U complicate the things +I'm going to say one last thing about + + align:start position:0% +I'm going to say one last thing about + + + align:start position:0% +I'm going to say one last thing about +you notice I said I I I made the + + align:start position:0% +you notice I said I I I made the + + + align:start position:0% +you notice I said I I I made the +Wasteland mythology a plural now to + + align:start position:0% +Wasteland mythology a plural now to + + + align:start position:0% +Wasteland mythology a plural now to +remind you of the fact that there are a + + align:start position:0% +remind you of the fact that there are a + + + align:start position:0% +remind you of the fact that there are a +series of mythologies the astonishing + + align:start position:0% +series of mythologies the astonishing + + + align:start position:0% +series of mythologies the astonishing +thing is how is how powerful they remain + + align:start position:0% +thing is how is how powerful they remain + + + align:start position:0% +thing is how is how powerful they remain +even in an era when television is + + align:start position:0% +even in an era when television is + + + align:start position:0% +even in an era when television is +undergoing this transmogrification and + + align:start position:0% +undergoing this transmogrification and + + + align:start position:0% +undergoing this transmogrification and +is altering its relation to the society + + align:start position:0% +is altering its relation to the society + + + align:start position:0% +is altering its relation to the society +and such dramatic ways uh but it struck + + align:start position:0% +and such dramatic ways uh but it struck + + + align:start position:0% +and such dramatic ways uh but it struck +me that there was one further thing to + + align:start position:0% +me that there was one further thing to + + + align:start position:0% +me that there was one further thing to +remind you about the basic term + + align:start position:0% +remind you about the basic term + + + align:start position:0% +remind you about the basic term +Wasteland of course as I as I've already + + align:start position:0% +Wasteland of course as I as I've already + + + align:start position:0% +Wasteland of course as I as I've already +mentioned comes from a famous speech + + align:start position:0% +mentioned comes from a famous speech + + + align:start position:0% +mentioned comes from a famous speech +made by the newly appointed John + + align:start position:0% +made by the newly appointed John + + + align:start position:0% +made by the newly appointed John +Kennedy's newly appointed head of the + + align:start position:0% +Kennedy's newly appointed head of the + + + align:start position:0% +Kennedy's newly appointed head of the +Federal Communications Commission to a + + align:start position:0% +Federal Communications Commission to a + + + align:start position:0% +Federal Communications Commission to a +gathering of broadcasters who expected + + align:start position:0% +gathering of broadcasters who expected + + + align:start position:0% +gathering of broadcasters who expected +uh the the usual P pum from a from a + + align:start position:0% +uh the the usual P pum from a from a + + + align:start position:0% +uh the the usual P pum from a from a +government uh uh official and instead + + align:start position:0% +government uh uh official and instead + + + align:start position:0% +government uh uh official and instead +receiv received this violent attack from + + align:start position:0% +receiv received this violent attack from + + + align:start position:0% +receiv received this violent attack from +the from the from this Young new + + align:start position:0% +the from the from this Young new + + + align:start position:0% +the from the from this Young new +Frontiersman and it was an attack in + + align:start position:0% +Frontiersman and it was an attack in + + + align:start position:0% +Frontiersman and it was an attack in +which he called television a vast + + align:start position:0% +which he called television a vast + + + align:start position:0% +which he called television a vast +Wasteland if we look back at the + + align:start position:0% +Wasteland if we look back at the + + + align:start position:0% +Wasteland if we look back at the +television of the early 60s the + + align:start position:0% +television of the early 60s the + + + align:start position:0% +television of the early 60s the +television of 1961 when he was speaking + + align:start position:0% +television of 1961 when he was speaking + + + align:start position:0% +television of 1961 when he was speaking +I think we could we could now in + + align:start position:0% +I think we could we could now in + + + align:start position:0% +I think we could we could now in +retrospect see that it was a very unfair + + align:start position:0% +retrospect see that it was a very unfair + + + align:start position:0% +retrospect see that it was a very unfair +and foolish description that there were + + align:start position:0% +and foolish description that there were + + + align:start position:0% +and foolish description that there were +many banal and foolish things on + + align:start position:0% +many banal and foolish things on + + + align:start position:0% +many banal and foolish things on +television but television was already a + + align:start position:0% +television but television was already a + + + align:start position:0% +television but television was already a +very complex instrument of popular + + align:start position:0% +very complex instrument of popular + + + align:start position:0% +very complex instrument of popular +culture and was doing a a multitude of + + align:start position:0% +culture and was doing a a multitude of + + + align:start position:0% +culture and was doing a a multitude of +functions uh one of the things that's + + align:start position:0% +functions uh one of the things that's + + + align:start position:0% +functions uh one of the things that's +wrong with the Wasteland mythology + + align:start position:0% +wrong with the Wasteland mythology + + + align:start position:0% +wrong with the Wasteland mythology +broadly is that people continue to + + align:start position:0% +broadly is that people continue to + + + align:start position:0% +broadly is that people continue to +generalize about the medium as if it's a + + align:start position:0% +generalize about the medium as if it's a + + + align:start position:0% +generalize about the medium as if it's a +single thing when of course it performs + + align:start position:0% +single thing when of course it performs + + + align:start position:0% +single thing when of course it performs +so many different and and and F and and + + align:start position:0% +so many different and and and F and and + + + align:start position:0% +so many different and and and F and and +fundamentally distinctive functions in + + align:start position:0% +fundamentally distinctive functions in + + + align:start position:0% +fundamentally distinctive functions in +the society that it's necessary to to + + align:start position:0% +the society that it's necessary to to + + + align:start position:0% +the society that it's necessary to to +distinguish it nobody nobody would + + align:start position:0% +distinguish it nobody nobody would + + + align:start position:0% +distinguish it nobody nobody would +generalize about the book the way people + + align:start position:0% +generalize about the book the way people + + + align:start position:0% +generalize about the book the way people +generalize about television I mean there + + align:start position:0% +generalize about television I mean there + + + align:start position:0% +generalize about television I mean there +are all kinds of books there's there are + + align:start position:0% +are all kinds of books there's there are + + + align:start position:0% +are all kinds of books there's there are +there are how-to books and pornographic + + align:start position:0% +there are how-to books and pornographic + + + align:start position:0% +there are how-to books and pornographic +books and wonderful novels and great and + + align:start position:0% +books and wonderful novels and great and + + + align:start position:0% +books and wonderful novels and great and +and works of history no one would say + + align:start position:0% +and works of history no one would say + + + align:start position:0% +and works of history no one would say +the book is a single thing and would + + align:start position:0% +the book is a single thing and would + + + align:start position:0% +the book is a single thing and would +generally say the book is utterly + + align:start position:0% +generally say the book is utterly + + + align:start position:0% +generally say the book is utterly +contemptible look at this horrible piece + + align:start position:0% +contemptible look at this horrible piece + + + align:start position:0% +contemptible look at this horrible piece +of pornography + + align:start position:0% +of pornography + + + align:start position:0% +of pornography +right the technology is evil the medium + + align:start position:0% +right the technology is evil the medium + + + align:start position:0% +right the technology is evil the medium +the medium is beneath contempt because + + align:start position:0% +the medium is beneath contempt because + + + align:start position:0% +the medium is beneath contempt because +of because Jerry fowell publishes this + + align:start position:0% +of because Jerry fowell publishes this + + + align:start position:0% +of because Jerry fowell publishes this +book no no no even if you have contempt + + align:start position:0% +book no no no even if you have contempt + + + align:start position:0% +book no no no even if you have contempt +for Jerry falwell's book it doesn't mean + + align:start position:0% +for Jerry falwell's book it doesn't mean + + + align:start position:0% +for Jerry falwell's book it doesn't mean +that all books fall into it's such an + + align:start position:0% +that all books fall into it's such an + + + align:start position:0% +that all books fall into it's such an +obvious thing to say and yet people + + align:start position:0% +obvious thing to say and yet people + + + align:start position:0% +obvious thing to say and yet people +continue to talk about television as if + + align:start position:0% +continue to talk about television as if + + + align:start position:0% +continue to talk about television as if +it's this monolith it was never a + + align:start position:0% +it's this monolith it was never a + + + align:start position:0% +it's this monolith it was never a +monolith it always provided news and + + align:start position:0% +monolith it always provided news and + + + align:start position:0% +monolith it always provided news and +variety programs and daytime serials and + + align:start position:0% +variety programs and daytime serials and + + + align:start position:0% +variety programs and daytime serials and +interviews and V various other forms of + + align:start position:0% +interviews and V various other forms of + + + align:start position:0% +interviews and V various other forms of +prime time fiction so even from the + + align:start position:0% +prime time fiction so even from the + + + align:start position:0% +prime time fiction so even from the +start it was a multi it was a + + align:start position:0% +start it was a multi it was a + + + align:start position:0% +start it was a multi it was a +multitudinous medium and to generalize + + align:start position:0% +multitudinous medium and to generalize + + + align:start position:0% +multitudinous medium and to generalize +so that's another objection to the what + + align:start position:0% +so that's another objection to the what + + + align:start position:0% +so that's another objection to the what +we'll call the Wasteland mythology the + + align:start position:0% +we'll call the Wasteland mythology the + + + align:start position:0% +we'll call the Wasteland mythology the +way it the way it reduces television to + + align:start position:0% +way it the way it reduces television to + + + align:start position:0% +way it the way it reduces television to +a monolithic experience which is true + + align:start position:0% +a monolithic experience which is true + + + align:start position:0% +a monolithic experience which is true +for no human being I mean no person who + + align:start position:0% +for no human being I mean no person who + + + align:start position:0% +for no human being I mean no person who +watches television experiences it + + align:start position:0% +watches television experiences it + + + align:start position:0% +watches television experiences it +monolithically and that doesn't even + + align:start position:0% +monolithically and that doesn't even + + + align:start position:0% +monolithically and that doesn't even +take account of the Fantastic variation + + align:start position:0% +take account of the Fantastic variation + + + align:start position:0% +take account of the Fantastic variation +and variety that one might acknowledge + + align:start position:0% +and variety that one might acknowledge + + + align:start position:0% +and variety that one might acknowledge +within particular single categories of + + align:start position:0% +within particular single categories of + + + align:start position:0% +within particular single categories of +programming I mean just to just to + + align:start position:0% +programming I mean just to just to + + + align:start position:0% +programming I mean just to just to +generalize in a persuasive way about the + + align:start position:0% +generalize in a persuasive way about the + + + align:start position:0% +generalize in a persuasive way about the +News broadcasting and and narrowcasting + + align:start position:0% +News broadcasting and and narrowcasting + + + align:start position:0% +News broadcasting and and narrowcasting +that's going on on television today is + + align:start position:0% +that's going on on television today is + + + align:start position:0% +that's going on on television today is +an immensely complicated job because + + align:start position:0% +an immensely complicated job because + + + align:start position:0% +an immensely complicated job because +there's so many kinds of news broadcast + + align:start position:0% +there's so many kinds of news broadcast + + + align:start position:0% +there's so many kinds of news broadcast +yes I was just thinking of the irony + + align:start position:0% +yes I was just thinking of the irony + + + align:start position:0% +yes I was just thinking of the irony +because that same Communications manager + + align:start position:0% +because that same Communications manager + + + align:start position:0% +because that same Communications manager +probably helped utilize television to + + align:start position:0% +probably helped utilize television to + + + align:start position:0% +probably helped utilize television to +completely sculpt and promote Kennedy's + + align:start position:0% +completely sculpt and promote Kennedy's + + + align:start position:0% +completely sculpt and promote Kennedy's +image I mean Kennedy was so good on + + align:start position:0% +image I mean Kennedy was so good on + + + align:start position:0% +image I mean Kennedy was so good on +television yes that's right and it was + + align:start position:0% +television yes that's right and it was + + + align:start position:0% +television yes that's right and it was +really important part of his legazy that + + align:start position:0% +really important part of his legazy that + + + align:start position:0% +really important part of his legazy that +is an interesting irony and I think + + align:start position:0% +is an interesting irony and I think + + + align:start position:0% +is an interesting irony and I think +that's right I mean the new uh was the + + align:start position:0% +that's right I mean the new uh was the + + + align:start position:0% +that's right I mean the new uh was the +was in some respects was the first + + align:start position:0% +was in some respects was the first + + + align:start position:0% +was in some respects was the first +television President and utilized + + align:start position:0% +television President and utilized + + + align:start position:0% +television President and utilized +television in a way that none of his + + align:start position:0% +television in a way that none of his + + + align:start position:0% +television in a way that none of his +predecessors had done there there are + + align:start position:0% +predecessors had done there there are + + + align:start position:0% +predecessors had done there there are +even arguments to the effect that the + + align:start position:0% +even arguments to the effect that the + + + align:start position:0% +even arguments to the effect that the +debates he had with Nixon which were + + align:start position:0% +debates he had with Nixon which were + + + align:start position:0% +debates he had with Nixon which were +televised debates were the secret to + + align:start position:0% +televised debates were the secret to + + + align:start position:0% +televised debates were the secret to +were the were the reason he was elected + + align:start position:0% +were the were the reason he was elected + + + align:start position:0% +were the were the reason he was elected +that he was better on television that he + + align:start position:0% +that he was better on television that he + + + align:start position:0% +that he was better on television that he +looked he looked more persuasive on + + align:start position:0% +looked he looked more persuasive on + + + align:start position:0% +looked he looked more persuasive on +television he was he he was U better at + + align:start position:0% +television he was he he was U better at + + + align:start position:0% +television he was he he was U better at +sound bites than his than his opponent + + align:start position:0% +sound bites than his than his opponent + + + align:start position:0% +sound bites than his than his opponent +was and so I think that's + + align:start position:0% +was and so I think that's + + + align:start position:0% +was and so I think that's +a a helpful and complicating point one + + align:start position:0% +a a helpful and complicating point one + + + align:start position:0% +a a helpful and complicating point one +one final point about the Wasteland + + align:start position:0% +one final point about the Wasteland + + + align:start position:0% +one final point about the Wasteland +mythology there's there's another kind + + align:start position:0% +mythology there's there's another kind + + + align:start position:0% +mythology there's there's another kind +of resonance that the term Wasteland has + + align:start position:0% +of resonance that the term Wasteland has + + + align:start position:0% +of resonance that the term Wasteland has +uh and some of you with literary + + align:start position:0% +uh and some of you with literary + + + align:start position:0% +uh and some of you with literary +backgrounds will pick up on it + + align:start position:0% +backgrounds will pick up on it + + + align:start position:0% +backgrounds will pick up on it +immediately and and I think it partly + + align:start position:0% +immediately and and I think it partly + + + align:start position:0% +immediately and and I think it partly +explains why the metaphor was so + + align:start position:0% +explains why the metaphor was so + + + align:start position:0% +explains why the metaphor was so +powerful especially among the educated + + align:start position:0% +powerful especially among the educated + + + align:start position:0% +powerful especially among the educated +classes the defining and in many ways + + align:start position:0% +classes the defining and in many ways + + + align:start position:0% +classes the defining and in many ways +ridiculously simplifying poem of the + + align:start position:0% +ridiculously simplifying poem of the + + + align:start position:0% +ridiculously simplifying poem of the +20th century in the English language is + + align:start position:0% +20th century in the English language is + + + align:start position:0% +20th century in the English language is +a poem by TS Elliott titled the + + align:start position:0% +a poem by TS Elliott titled the + + + align:start position:0% +a poem by TS Elliott titled the +Wasteland published in 1922 it purported + + align:start position:0% +Wasteland published in 1922 it purported + + + align:start position:0% +Wasteland published in 1922 it purported +to describe the debased and destructive + + align:start position:0% +to describe the debased and destructive + + + align:start position:0% +to describe the debased and destructive +uh conditions of Modern Life uh a world + + align:start position:0% +uh conditions of Modern Life uh a world + + + align:start position:0% +uh conditions of Modern Life uh a world +a world that was in Elliot's view an + + align:start position:0% +a world that was in Elliot's view an + + + align:start position:0% +a world that was in Elliot's view an +horrific moral and spiritual Wasteland a + + align:start position:0% +horrific moral and spiritual Wasteland a + + + align:start position:0% +horrific moral and spiritual Wasteland a +place of a place of Despair and + + align:start position:0% +place of a place of Despair and + + + align:start position:0% +place of a place of Despair and +emptiness and uh uh and and and human + + align:start position:0% +emptiness and uh uh and and and human + + + align:start position:0% +emptiness and uh uh and and and human +negativity uh in its day it was Pro + + align:start position:0% +negativity uh in its day it was Pro + + + align:start position:0% +negativity uh in its day it was Pro +unquestionably the most influential and + + align:start position:0% +unquestionably the most influential and + + + align:start position:0% +unquestionably the most influential and +important uh uh poem in the English + + align:start position:0% +important uh uh poem in the English + + + align:start position:0% +important uh uh poem in the English +language and for several Generations it + + align:start position:0% +language and for several Generations it + + + align:start position:0% +language and for several Generations it +was taken to be the definitive + + align:start position:0% +was taken to be the definitive + + + align:start position:0% +was taken to be the definitive +description uh of mod life of life in + + align:start position:0% +description uh of mod life of life in + + + align:start position:0% +description uh of mod life of life in +the mass democracies of Modern Life + + align:start position:0% +the mass democracies of Modern Life + + + align:start position:0% +the mass democracies of Modern Life +after the death of of of of of religious + + align:start position:0% +after the death of of of of of religious + + + align:start position:0% +after the death of of of of of religious +observance uh and uh it's only in in + + align:start position:0% +observance uh and uh it's only in in + + + align:start position:0% +observance uh and uh it's only in in +relatively recent times over the past + + align:start position:0% +relatively recent times over the past + + + align:start position:0% +relatively recent times over the past +quarter of a century and a bit more that + + align:start position:0% +quarter of a century and a bit more that + + + align:start position:0% +quarter of a century and a bit more that +the poem has been recognized for the + + align:start position:0% +the poem has been recognized for the + + + align:start position:0% +the poem has been recognized for the +much more personal and in many ways not + + align:start position:0% +much more personal and in many ways not + + + align:start position:0% +much more personal and in many ways not +just eccentric but perhaps neurotic + + align:start position:0% +just eccentric but perhaps neurotic + + + align:start position:0% +just eccentric but perhaps neurotic +expression that in fact it was and uh + + align:start position:0% +expression that in fact it was and uh + + + align:start position:0% +expression that in fact it was and uh +and uh there are many other texts + + align:start position:0% +and uh there are many other texts + + + align:start position:0% +and uh there are many other texts +including Jo Joyce's great novel ulyses + + align:start position:0% +including Jo Joyce's great novel ulyses + + + align:start position:0% +including Jo Joyce's great novel ulyses +uh which + + align:start position:0% +uh which + + + align:start position:0% +uh which +which Define and encompass modern + + align:start position:0% +which Define and encompass modern + + + align:start position:0% +which Define and encompass modern +experience 20th century experience in + + align:start position:0% +experience 20th century experience in + + + align:start position:0% +experience 20th century experience in +much more uh uh uh complex and uh + + align:start position:0% +much more uh uh uh complex and uh + + + align:start position:0% +much more uh uh uh complex and uh +unsimplified ways but the but the cache + + align:start position:0% +unsimplified ways but the but the cache + + + align:start position:0% +unsimplified ways but the but the cache +that the term has the feeling that the + + align:start position:0% +that the term has the feeling that the + + + align:start position:0% +that the term has the feeling that the +term the Wasteland uh uh uh uh would + + align:start position:0% +term the Wasteland uh uh uh uh would + + + align:start position:0% +term the Wasteland uh uh uh uh would +have implicitly had for many educated + + align:start position:0% +have implicitly had for many educated + + + align:start position:0% +have implicitly had for many educated +people also explains I think something + + align:start position:0% +people also explains I think something + + + align:start position:0% +people also explains I think something +of the power of the metaphor uh in our + + align:start position:0% +of the power of the metaphor uh in our + + + align:start position:0% +of the power of the metaphor uh in our +in its uh use as a descri as a as a + + align:start position:0% +in its uh use as a descri as a as a + + + align:start position:0% +in its uh use as a descri as a as a +descriptor for what became the dominant + + align:start position:0% +descriptor for what became the dominant + + + align:start position:0% +descriptor for what became the dominant +ium of communication in the in the + + align:start position:0% +ium of communication in the in the + + + align:start position:0% +ium of communication in the in the +country + + align:start position:0% + + + + align:start position:0% + +Susanna there's something that's um been + + align:start position:0% +Susanna there's something that's um been + + + align:start position:0% +Susanna there's something that's um been +haunting me I guess about uh the + + align:start position:0% +haunting me I guess about uh the + + + align:start position:0% +haunting me I guess about uh the +discussion of this Wasteland metaphor + + align:start position:0% +discussion of this Wasteland metaphor + + + align:start position:0% +discussion of this Wasteland metaphor +and if this point doesn't seem a good + + align:start position:0% +and if this point doesn't seem a good + + + align:start position:0% +and if this point doesn't seem a good +one to discuss now then um perhaps we + + align:start position:0% +one to discuss now then um perhaps we + + + align:start position:0% +one to discuss now then um perhaps we +can come back to it later but but I I + + align:start position:0% +can come back to it later but but I I + + + align:start position:0% +can come back to it later but but I I +hope we can take it up again um we've + + align:start position:0% +hope we can take it up again um we've + + + align:start position:0% +hope we can take it up again um we've +been discussing this this metaphor as if + + align:start position:0% +been discussing this this metaphor as if + + + align:start position:0% +been discussing this this metaphor as if +it were solely imposed on as a + + align:start position:0% +it were solely imposed on as a + + + align:start position:0% +it were solely imposed on as a +description of the medium and everyone + + align:start position:0% +description of the medium and everyone + + + align:start position:0% +description of the medium and everyone +who watches it by politicians perhaps by + + align:start position:0% +who watches it by politicians perhaps by + + + align:start position:0% +who watches it by politicians perhaps by +academics and intellectuals + + align:start position:0% +academics and intellectuals + + + align:start position:0% +academics and intellectuals +on the other hand people seem to have a + + align:start position:0% +on the other hand people seem to have a + + + align:start position:0% +on the other hand people seem to have a +very complicated relationship with + + align:start position:0% +very complicated relationship with + + + align:start position:0% +very complicated relationship with +television and as we can pick up by + + align:start position:0% +television and as we can pick up by + + + align:start position:0% +television and as we can pick up by +reading some of the essays we've been + + align:start position:0% +reading some of the essays we've been + + + align:start position:0% +reading some of the essays we've been +reading for example the Paul Klein essay + + align:start position:0% +reading for example the Paul Klein essay + + + align:start position:0% +reading for example the Paul Klein essay +Begins by quoting people who say that + + align:start position:0% +Begins by quoting people who say that + + + align:start position:0% +Begins by quoting people who say that +it's the self-loathing that people + + align:start position:0% +it's the self-loathing that people + + + align:start position:0% +it's the self-loathing that people +Express when they watch TV which they + + align:start position:0% +Express when they watch TV which they + + + align:start position:0% +Express when they watch TV which they +did at that time I see and which they + + align:start position:0% +did at that time I see and which they + + + align:start position:0% +did at that time I see and which they +certainly do now I suppose one way of + + align:start position:0% +certainly do now I suppose one way of + + + align:start position:0% +certainly do now I suppose one way of +looking at it is by saying that people + + align:start position:0% +looking at it is by saying that people + + + align:start position:0% +looking at it is by saying that people +only pretend to be disturbed by their + + align:start position:0% +only pretend to be disturbed by their + + + align:start position:0% +only pretend to be disturbed by their +own relationship with television or that + + align:start position:0% +own relationship with television or that + + + align:start position:0% +own relationship with television or that +we've been brainwashed into thinking + + align:start position:0% +we've been brainwashed into thinking + + + align:start position:0% +we've been brainwashed into thinking +that we're addicted to it and not really + + align:start position:0% +that we're addicted to it and not really + + + align:start position:0% +that we're addicted to it and not really +interacting with it in an stimulating + + align:start position:0% +interacting with it in an stimulating + + + align:start position:0% +interacting with it in an stimulating +sense but I do know that many people + + align:start position:0% +sense but I do know that many people + + + align:start position:0% +sense but I do know that many people +seem to be seem to find television + + align:start position:0% +seem to be seem to find television + + + align:start position:0% +seem to be seem to find television +addicting seem say I get up after a + + align:start position:0% +addicting seem say I get up after a + + + align:start position:0% +addicting seem say I get up after a +couple of hours and I don't feel that + + align:start position:0% +couple of hours and I don't feel that + + + align:start position:0% +couple of hours and I don't feel that +I've used my time well and I know that + + align:start position:0% +I've used my time well and I know that + + + align:start position:0% +I've used my time well and I know that +my own relationship to TV is very very + + align:start position:0% +my own relationship to TV is very very + + + align:start position:0% +my own relationship to TV is very very +complicated we haven't really discussed + + align:start position:0% +complicated we haven't really discussed + + + align:start position:0% +complicated we haven't really discussed +this question whether that's solely a + + align:start position:0% +this question whether that's solely a + + + align:start position:0% +this question whether that's solely a +function of something which we've all + + align:start position:0% +function of something which we've all + + + align:start position:0% +function of something which we've all +been told or whether on a personal level + + align:start position:0% +been told or whether on a personal level + + + align:start position:0% +been told or whether on a personal level +people also have this ambivalent + + align:start position:0% +people also have this ambivalent + + + align:start position:0% +people also have this ambivalent +relationship to TV in which case maybe + + align:start position:0% +relationship to TV in which case maybe + + + align:start position:0% +relationship to TV in which case maybe +there is some value in the our our + + align:start position:0% +there is some value in the our our + + + align:start position:0% +there is some value in the our our +suspicions of it well I think there + + align:start position:0% +suspicions of it well I think there + + + align:start position:0% +suspicions of it well I think there +there's certain look I I I haven't meant + + align:start position:0% +there's certain look I I I haven't meant + + + align:start position:0% +there's certain look I I I haven't meant +to suggest that there aren't all kinds + + align:start position:0% +to suggest that there aren't all kinds + + + align:start position:0% +to suggest that there aren't all kinds +of reasons to be incredibly suspicious + + align:start position:0% +of reasons to be incredibly suspicious + + + align:start position:0% +of reasons to be incredibly suspicious +of Television I mean I think television + + align:start position:0% +of Television I mean I think television + + + align:start position:0% +of Television I mean I think television +promulgates all kinds of attitudes and + + align:start position:0% +promulgates all kinds of attitudes and + + + align:start position:0% +promulgates all kinds of attitudes and +Views that are dubious and questionable + + align:start position:0% +Views that are dubious and questionable + + + align:start position:0% +Views that are dubious and questionable +uh I and and I I also think of course + + align:start position:0% +uh I and and I I also think of course + + + align:start position:0% +uh I and and I I also think of course +it's the case that particular viewers + + align:start position:0% +it's the case that particular viewers + + + align:start position:0% +it's the case that particular viewers +can use television in ways that are not + + align:start position:0% +can use television in ways that are not + + + align:start position:0% +can use television in ways that are not +not healthy for them you're certainly + + align:start position:0% +not healthy for them you're certainly + + + align:start position:0% +not healthy for them you're certainly +right I think that many people exper exp + + align:start position:0% +right I think that many people exper exp + + + align:start position:0% +right I think that many people exper exp +erience the medium in a in a in a way + + align:start position:0% +erience the medium in a in a in a way + + + align:start position:0% +erience the medium in a in a in a way +that encourages their own that + + align:start position:0% +that encourages their own that + + + align:start position:0% +that encourages their own that +encourages them to feel negative toward + + align:start position:0% +encourages them to feel negative toward + + + align:start position:0% +encourages them to feel negative toward +it although it's a complicated an + + align:start position:0% +it although it's a complicated an + + + align:start position:0% +it although it's a complicated an +ambivalent relation as you suggest + + align:start position:0% +ambivalent relation as you suggest + + + align:start position:0% +ambivalent relation as you suggest +because they often are also uh uh + + align:start position:0% +because they often are also uh uh + + + align:start position:0% +because they often are also uh uh +yielding to the medium in a certain way + + align:start position:0% +yielding to the medium in a certain way + + + align:start position:0% +yielding to the medium in a certain way +or allowing themselves to vegge out as + + align:start position:0% +or allowing themselves to vegge out as + + + align:start position:0% +or allowing themselves to vegge out as +they often say when they when they look + + align:start position:0% +they often say when they when they look + + + align:start position:0% +they often say when they when they look +at the medium but I think your your the + + align:start position:0% +at the medium but I think your your the + + + align:start position:0% +at the medium but I think your your the +C your central point is very important + + align:start position:0% +C your central point is very important + + + align:start position:0% +C your central point is very important +and I haven't haven't meant to imply + + align:start position:0% +and I haven't haven't meant to imply + + + align:start position:0% +and I haven't haven't meant to imply +that I disagree with it in fact I I + + align:start position:0% +that I disagree with it in fact I I + + + align:start position:0% +that I disagree with it in fact I I +think it's absolutely right uh one of + + align:start position:0% +think it's absolutely right uh one of + + + align:start position:0% +think it's absolutely right uh one of +the reasons for the power of the + + align:start position:0% +the reasons for the power of the + + + align:start position:0% +the reasons for the power of the +Wasteland mythology is that it was so + + align:start position:0% +Wasteland mythology is that it was so + + + align:start position:0% +Wasteland mythology is that it was so +widely accepted by people who engaged in + + align:start position:0% +widely accepted by people who engaged in + + + align:start position:0% +widely accepted by people who engaged in +a kind of cognitive dissonance in their + + align:start position:0% +a kind of cognitive dissonance in their + + + align:start position:0% +a kind of cognitive dissonance in their +own attitudes toward the media they + + align:start position:0% +own attitudes toward the media they + + + align:start position:0% +own attitudes toward the media they +would on the one hand actually watch + + align:start position:0% +would on the one hand actually watch + + + align:start position:0% +would on the one hand actually watch +television all the time and get a lot + + align:start position:0% +television all the time and get a lot + + + align:start position:0% +television all the time and get a lot +out of it and actually enjoy it but on + + align:start position:0% +out of it and actually enjoy it but on + + + align:start position:0% +out of it and actually enjoy it but on +the other hand they would also feel that + + align:start position:0% +the other hand they would also feel that + + + align:start position:0% +the other hand they would also feel that +it was dangerous and bad some of that + + align:start position:0% +it was dangerous and bad some of that + + + align:start position:0% +it was dangerous and bad some of that +was a form of condescension uh in which + + align:start position:0% +was a form of condescension uh in which + + + align:start position:0% +was a form of condescension uh in which +C uh in which people would would in some + + align:start position:0% +C uh in which people would would in some + + + align:start position:0% +C uh in which people would would in some +sense exempt themselves from the dire + + align:start position:0% +sense exempt themselves from the dire + + + align:start position:0% +sense exempt themselves from the dire +effects that they felt were were likely + + align:start position:0% +effects that they felt were were likely + + + align:start position:0% +effects that they felt were were likely +to be visited on others and there is a + + align:start position:0% +to be visited on others and there is a + + + align:start position:0% +to be visited on others and there is a +is a kind of there's a kind of class + + align:start position:0% +is a kind of there's a kind of class + + + align:start position:0% +is a kind of there's a kind of class +Warfare Dimension to certain aspects of + + align:start position:0% +Warfare Dimension to certain aspects of + + + align:start position:0% +Warfare Dimension to certain aspects of +the way the mythology is deployed has + + align:start position:0% +the way the mythology is deployed has + + + align:start position:0% +the way the mythology is deployed has +been deployed in the past for example in + + align:start position:0% +been deployed in the past for example in + + + align:start position:0% +been deployed in the past for example in +uh uh in which uh there's a a large + + align:start position:0% +uh uh in which uh there's a a large + + + align:start position:0% +uh uh in which uh there's a a large +discourse about the danger of Television + + align:start position:0% +discourse about the danger of Television + + + align:start position:0% +discourse about the danger of Television +to children and a good deal of that has + + align:start position:0% +to children and a good deal of that has + + + align:start position:0% +to children and a good deal of that has +to do is specifically devoted to + + align:start position:0% +to do is specifically devoted to + + + align:start position:0% +to do is specifically devoted to +children to latch key kids right to kids + + align:start position:0% +children to latch key kids right to kids + + + align:start position:0% +children to latch key kids right to kids +to ghetto children to Children whose + + align:start position:0% +to ghetto children to Children whose + + + align:start position:0% +to ghetto children to Children whose +parents have to work so if you the + + align:start position:0% +parents have to work so if you the + + + align:start position:0% +parents have to work so if you the +children come home and television's the + + align:start position:0% +children come home and television's the + + + align:start position:0% +children come home and television's the +only babysitter and and the people who + + align:start position:0% +only babysitter and and the people who + + + align:start position:0% +only babysitter and and the people who +make these arguments of course are in + + align:start position:0% +make these arguments of course are in + + + align:start position:0% +make these arguments of course are in +effect exempting their own families and + + align:start position:0% +effect exempting their own families and + + + align:start position:0% +effect exempting their own families and +their own children from the baleful + + align:start position:0% +their own children from the baleful + + + align:start position:0% +their own children from the baleful +effects of a medium that they think is + + align:start position:0% +effects of a medium that they think is + + + align:start position:0% +effects of a medium that they think is +going to harm others so that's also an + + align:start position:0% +going to harm others so that's also an + + + align:start position:0% +going to harm others so that's also an +aspect of the of the case but I but I'm + + align:start position:0% +aspect of the of the case but I but I'm + + + align:start position:0% +aspect of the of the case but I but I'm +I'm in a in a way that's not uh uh + + align:start position:0% +I'm in a in a way that's not uh uh + + + align:start position:0% +I'm in a in a way that's not uh uh +exactly what you were saying Susanna and + + align:start position:0% +exactly what you were saying Susanna and + + + align:start position:0% +exactly what you were saying Susanna and +and and I agree with what you're saying + + align:start position:0% +and and I agree with what you're saying + + + align:start position:0% +and and I agree with what you're saying +it seems to me that that one reason for + + align:start position:0% +it seems to me that that one reason for + + + align:start position:0% +it seems to me that that one reason for +the power of the Wasteland mythology is + + align:start position:0% +the power of the Wasteland mythology is + + + align:start position:0% +the power of the Wasteland mythology is +that at some level many people in their + + align:start position:0% +that at some level many people in their + + + align:start position:0% +that at some level many people in their +experience of Television have the have + + align:start position:0% +experience of Television have the have + + + align:start position:0% +experience of Television have the have +the mythology ratified they see a + + align:start position:0% +the mythology ratified they see a + + + align:start position:0% +the mythology ratified they see a +tremendous amount of Bal programming + + align:start position:0% +tremendous amount of Bal programming + + + align:start position:0% +tremendous amount of Bal programming +they see incredible foolishness and + + align:start position:0% +they see incredible foolishness and + + + align:start position:0% +they see incredible foolishness and +silliness on the medium and they even + + align:start position:0% +silliness on the medium and they even + + + align:start position:0% +silliness on the medium and they even +see that there's a certain sense in + + align:start position:0% +see that there's a certain sense in + + + align:start position:0% +see that there's a certain sense in +which they can sort of just relax in + + align:start position:0% +which they can sort of just relax in + + + align:start position:0% +which they can sort of just relax in +front of it and allow the words and + + align:start position:0% +front of it and allow the words and + + + align:start position:0% +front of it and allow the words and +images to pour over them in a way that's + + align:start position:0% +images to pour over them in a way that's + + + align:start position:0% +images to pour over them in a way that's +very relaxing and mind-numbing and they + + align:start position:0% +very relaxing and mind-numbing and they + + + align:start position:0% +very relaxing and mind-numbing and they +and and they and they draw from that the + + align:start position:0% +and and they and they draw from that the + + + align:start position:0% +and and they and they draw from that the +conclusion that that that that that the + + align:start position:0% +conclusion that that that that that the + + + align:start position:0% +conclusion that that that that that the +uh arguments against television and + + align:start position:0% +uh arguments against television and + + + align:start position:0% +uh arguments against television and +especially against its narcotizing + + align:start position:0% +especially against its narcotizing + + + align:start position:0% +especially against its narcotizing +effects have some have some uh Power uh + + align:start position:0% +effects have some have some uh Power uh + + + align:start position:0% +effects have some have some uh Power uh +I think it is true that people can allow + + align:start position:0% +I think it is true that people can allow + + + align:start position:0% +I think it is true that people can allow +themselves to fall into such a relation + + align:start position:0% +themselves to fall into such a relation + + + align:start position:0% +themselves to fall into such a relation +to the medium but there's no evidence to + + align:start position:0% +to the medium but there's no evidence to + + + align:start position:0% +to the medium but there's no evidence to +suggest that in fact those are features + + align:start position:0% +suggest that in fact those are features + + + align:start position:0% +suggest that in fact those are features +that are that are uh unique to + + align:start position:0% +that are that are uh unique to + + + align:start position:0% +that are that are uh unique to +television people there are there are + + align:start position:0% +television people there are there are + + + align:start position:0% +television people there are there are +there are other uh + + align:start position:0% +there are other uh + + + align:start position:0% +there are other uh +narot not exactly narcotizing experience + + align:start position:0% +narot not exactly narcotizing experience + + + align:start position:0% +narot not exactly narcotizing experience +there are other other experiences in in + + align:start position:0% +there are other other experiences in in + + + align:start position:0% +there are other other experiences in in +our lives that that can cause us to sort + + align:start position:0% +our lives that that can cause us to sort + + + align:start position:0% +our lives that that can cause us to sort +of veg out or fall or fall half asleep + + align:start position:0% +of veg out or fall or fall half asleep + + + align:start position:0% +of veg out or fall or fall half asleep +and and it's not intrinsic in the medium + + align:start position:0% +and and it's not intrinsic in the medium + + + align:start position:0% +and and it's not intrinsic in the medium +because of course you can also re + + align:start position:0% +because of course you can also re + + + align:start position:0% +because of course you can also re +interact with television in in much more + + align:start position:0% +interact with television in in much more + + + align:start position:0% +interact with television in in much more +alert and complex ways one might + + align:start position:0% +alert and complex ways one might + + + align:start position:0% +alert and complex ways one might +actually turn the argument on its head + + align:start position:0% +actually turn the argument on its head + + + align:start position:0% +actually turn the argument on its head +if one wanted to say that one of the + + align:start position:0% +if one wanted to say that one of the + + + align:start position:0% +if one wanted to say that one of the +most remarkable things about the medium + + align:start position:0% +most remarkable things about the medium + + + align:start position:0% +most remarkable things about the medium +is that is that it allows this this + + align:start position:0% +is that is that it allows this this + + + align:start position:0% +is that is that it allows this this +level of semiconscious interaction with + + align:start position:0% +level of semiconscious interaction with + + + align:start position:0% +level of semiconscious interaction with +it uh as well as allowing a much more + + align:start position:0% +it uh as well as allowing a much more + + + align:start position:0% +it uh as well as allowing a much more +complex active kind of relation uh to + + align:start position:0% +complex active kind of relation uh to + + + align:start position:0% +complex active kind of relation uh to +the medium the only the only uh place + + align:start position:0% +the medium the only the only uh place + + + align:start position:0% +the medium the only the only uh place +that I would hesitate uh the only place + + align:start position:0% +that I would hesitate uh the only place + + + align:start position:0% +that I would hesitate uh the only place +the only area in which I I would descent + + align:start position:0% +the only area in which I I would descent + + + align:start position:0% +the only area in which I I would descent +from the implications of your remark + + align:start position:0% +from the implications of your remark + + + align:start position:0% +from the implications of your remark +Susanna is is here and although you + + align:start position:0% +Susanna is is here and although you + + + align:start position:0% +Susanna is is here and although you +didn't actually say this so I wouldn't + + align:start position:0% +didn't actually say this so I wouldn't + + + align:start position:0% +didn't actually say this so I wouldn't +shouldn't attribute this view to you is + + align:start position:0% +shouldn't attribute this view to you is + + + align:start position:0% +shouldn't attribute this view to you is +the notion that there are negative + + align:start position:0% +the notion that there are negative + + + align:start position:0% +the notion that there are negative +long-term effects from this kind of + + align:start position:0% +long-term effects from this kind of + + + align:start position:0% +long-term effects from this kind of +vegging out there's no real evidence for + + align:start position:0% +vegging out there's no real evidence for + + + align:start position:0% +vegging out there's no real evidence for +that even though it is taken for granted + + align:start position:0% +that even though it is taken for granted + + + align:start position:0% +that even though it is taken for granted +that the uh by by by the by the + + align:start position:0% +that the uh by by by the by the + + + align:start position:0% +that the uh by by by the by the +wastelanders that there are uh negative + + align:start position:0% +wastelanders that there are uh negative + + + align:start position:0% +wastelanders that there are uh negative +negative effects from it uh there's no + + align:start position:0% +negative effects from it uh there's no + + + align:start position:0% +negative effects from it uh there's no +there's no and and and even the even the + + align:start position:0% +there's no and and and even the even the + + + align:start position:0% +there's no and and and even the even the +metaphor of addiction seems + + align:start position:0% +metaphor of addiction seems + + + align:start position:0% +metaphor of addiction seems +inappropriate because because it is not + + align:start position:0% +inappropriate because because it is not + + + align:start position:0% +inappropriate because because it is not +in fact a chemical addiction it is not + + align:start position:0% +in fact a chemical addiction it is not + + + align:start position:0% +in fact a chemical addiction it is not +the equivalent of tobacco addiction + + align:start position:0% +the equivalent of tobacco addiction + + + align:start position:0% +the equivalent of tobacco addiction +which we know actually affects the + + align:start position:0% +which we know actually affects the + + + align:start position:0% +which we know actually affects the +chemistry of the of the body or heroin + + align:start position:0% +chemistry of the of the body or heroin + + + align:start position:0% +chemistry of the of the body or heroin +addiction which again is a biological + + align:start position:0% +addiction which again is a biological + + + align:start position:0% +addiction which again is a biological +experience + + align:start position:0% +experience + + + align:start position:0% +experience +in a way that does not that does not + + align:start position:0% +in a way that does not that does not + + + align:start position:0% +in a way that does not that does not +seem to be true and people people go + + align:start position:0% +seem to be true and people people go + + + align:start position:0% +seem to be true and people people go +cold turkey off television all the time + + align:start position:0% +cold turkey off television all the time + + + align:start position:0% +cold turkey off television all the time +without any apparent negative + + align:start position:0% +without any apparent negative + + + align:start position:0% +without any apparent negative +consequences one more comment we'll go + + align:start position:0% +consequences one more comment we'll go + + + align:start position:0% +consequences one more comment we'll go +move + + align:start position:0% + + + + align:start position:0% + +on I don't plan to pursue this much much + + align:start position:0% +on I don't plan to pursue this much much + + + align:start position:0% +on I don't plan to pursue this much much +further I I just wanted to complicate + + align:start position:0% +further I I just wanted to complicate + + + align:start position:0% +further I I just wanted to complicate +that a little by mentioning that there + + align:start position:0% +that a little by mentioning that there + + + align:start position:0% +that a little by mentioning that there +are other one kind of addiction + + align:start position:0% +are other one kind of addiction + + + align:start position:0% +are other one kind of addiction +currently under debate for example is + + align:start position:0% +currently under debate for example is + + + align:start position:0% +currently under debate for example is +the question of whether gambling is an + + align:start position:0% +the question of whether gambling is an + + + align:start position:0% +the question of whether gambling is an +addiction for some people I just wanted + + align:start position:0% +addiction for some people I just wanted + + + align:start position:0% +addiction for some people I just wanted +to complicate the point by noting that + + align:start position:0% +to complicate the point by noting that + + + align:start position:0% +to complicate the point by noting that +addiction is you know obviously not + + align:start position:0% +addiction is you know obviously not + + + align:start position:0% +addiction is you know obviously not +always Us in the purely physical sense + + align:start position:0% +always Us in the purely physical sense + + + align:start position:0% +always Us in the purely physical sense +and I I think that that is presumably it + + align:start position:0% +and I I think that that is presumably it + + + align:start position:0% +and I I think that that is presumably it +must be what people have in mind when + + align:start position:0% +must be what people have in mind when + + + align:start position:0% +must be what people have in mind when +they talk of the television addiction + + align:start position:0% +they talk of the television addiction + + + align:start position:0% +they talk of the television addiction +okay I mean I think those are very + + align:start position:0% +okay I mean I think those are very + + + align:start position:0% +okay I mean I think those are very +dubious extensions of of of the notion + + align:start position:0% +dubious extensions of of of the notion + + + align:start position:0% +dubious extensions of of of the notion +of addiction just as they're under + + align:start position:0% +of addiction just as they're under + + + align:start position:0% +of addiction just as they're under +debate you know they just just as you + + align:start position:0% +debate you know they just just as you + + + align:start position:0% +debate you know they just just as you +know just as we're in our in the current + + align:start position:0% +know just as we're in our in the current + + + align:start position:0% +know just as we're in our in the current +moment that we're in the United States + + align:start position:0% +moment that we're in the United States + + + align:start position:0% +moment that we're in the United States +now there are very dubious extensions of + + align:start position:0% +now there are very dubious extensions of + + + align:start position:0% +now there are very dubious extensions of +Notions of therapy to uh and and and uh + + align:start position:0% +Notions of therapy to uh and and and uh + + + align:start position:0% +Notions of therapy to uh and and and uh +uh trauma the idea of the idea of trauma + + align:start position:0% +uh trauma the idea of the idea of trauma + + + align:start position:0% +uh trauma the idea of the idea of trauma +is now being extended Much More Much + + align:start position:0% +is now being extended Much More Much + + + align:start position:0% +is now being extended Much More Much +More widely and broadly than is probably + + align:start position:0% +More widely and broadly than is probably + + + align:start position:0% +More widely and broadly than is probably +uh medically or biologically accurate + + align:start position:0% +uh medically or biologically accurate + + + align:start position:0% +uh medically or biologically accurate +and it may not be an entirely uh helpful + + align:start position:0% +and it may not be an entirely uh helpful + + + align:start position:0% +and it may not be an entirely uh helpful +extension in in the case of these + + align:start position:0% +extension in in the case of these + + + align:start position:0% +extension in in the case of these +definition I mean look there are people + + align:start position:0% +definition I mean look there are people + + + align:start position:0% +definition I mean look there are people +who say that that's that uh there are + + align:start position:0% +who say that that's that uh there are + + + align:start position:0% +who say that that's that uh there are +there are people who extend the notion + + align:start position:0% +there are people who extend the notion + + + align:start position:0% +there are people who extend the notion +of addiction to to people to to uh to uh + + align:start position:0% +of addiction to to people to to uh to uh + + + align:start position:0% +of addiction to to people to to uh to uh +to sexual behavior and people say oh I I + + align:start position:0% +to sexual behavior and people say oh I I + + + align:start position:0% +to sexual behavior and people say oh I I +have to confess I'm I'm an adulter + + align:start position:0% +have to confess I'm I'm an adulter + + + align:start position:0% +have to confess I'm I'm an adulter +because I'm a sex addict and uh one can + + align:start position:0% +because I'm a sex addict and uh one can + + + align:start position:0% +because I'm a sex addict and uh one can +one can easily see that in that instance + + align:start position:0% +one can easily see that in that instance + + + align:start position:0% +one can easily see that in that instance +of why why the notion of it's very + + align:start position:0% +of why why the notion of it's very + + + align:start position:0% +of why why the notion of it's very +dangerous I think to extend the notion + + align:start position:0% +dangerous I think to extend the notion + + + align:start position:0% +dangerous I think to extend the notion +of addiction uh to to non-biological + + align:start position:0% +of addiction uh to to non-biological + + + align:start position:0% +of addiction uh to to non-biological +base to to to to Notions of you know + + align:start position:0% +base to to to to Notions of you know + + + align:start position:0% +base to to to to Notions of you know +there preferences that people have + + align:start position:0% +there preferences that people have + + + align:start position:0% +there preferences that people have +trouble breaking that's a very different + + align:start position:0% +trouble breaking that's a very different + + + align:start position:0% +trouble breaking that's a very different +kind of thing I I acknowledge you're + + align:start position:0% +kind of thing I I acknowledge you're + + + align:start position:0% +kind of thing I I acknowledge you're +right that it that it is part of the + + align:start position:0% +right that it that it is part of the + + + align:start position:0% +right that it that it is part of the +discourse of the society but I think + + align:start position:0% +discourse of the society but I think + + + align:start position:0% +discourse of the society but I think +it's a discourse that we might want to + + align:start position:0% +it's a discourse that we might want to + + + align:start position:0% +it's a discourse that we might want to +want to uh look on very skeptically but + + align:start position:0% +want to uh look on very skeptically but + + + align:start position:0% +want to uh look on very skeptically but +let me let me continue here because I I + + align:start position:0% +let me let me continue here because I I + + + align:start position:0% +let me let me continue here because I I +I don't want to keep doing this wind up + + align:start position:0% +I don't want to keep doing this wind up + + + align:start position:0% +I don't want to keep doing this wind up +and not actually get to our to to the + + align:start position:0% +and not actually get to our to to the + + + align:start position:0% +and not actually get to our to to the +core of the course which is the reading + + align:start position:0% +core of the course which is the reading + + + align:start position:0% +core of the course which is the reading +of programs in some kind of a systematic + + align:start position:0% +of programs in some kind of a systematic + + + align:start position:0% +of programs in some kind of a systematic +way the next step we make in the + + align:start position:0% +way the next step we make in the + + + align:start position:0% +way the next step we make in the +argument is to say okay if the Wasteland + + align:start position:0% +argument is to say okay if the Wasteland + + + align:start position:0% +argument is to say okay if the Wasteland +mythology these various simplified uh + + align:start position:0% +mythology these various simplified uh + + + align:start position:0% +mythology these various simplified uh +ways of of of understanding television + + align:start position:0% +ways of of of understanding television + + + align:start position:0% +ways of of of understanding television +are inadequate what would be an adequate + + align:start position:0% +are inadequate what would be an adequate + + + align:start position:0% +are inadequate what would be an adequate +way and what I what what I've suggested + + align:start position:0% +way and what I what what I've suggested + + + align:start position:0% +way and what I what what I've suggested +to you is of course is uh is not that we + + align:start position:0% +to you is of course is uh is not that we + + + align:start position:0% +to you is of course is uh is not that we +suddenly begin to tell some kind of a + + align:start position:0% +suddenly begin to tell some kind of a + + + align:start position:0% +suddenly begin to tell some kind of a +noble or triumphal story about the + + align:start position:0% +noble or triumphal story about the + + + align:start position:0% +noble or triumphal story about the +mediev and all but we simply acknowledge + + align:start position:0% +mediev and all but we simply acknowledge + + + align:start position:0% +mediev and all but we simply acknowledge +that it is a cultural formation that + + align:start position:0% +that it is a cultural formation that + + + align:start position:0% +that it is a cultural formation that +that a cultural formation which has + + align:start position:0% +that a cultural formation which has + + + align:start position:0% +that a cultural formation which has +ancestors and that we can learn + + align:start position:0% +ancestors and that we can learn + + + align:start position:0% +ancestors and that we can learn +something about the development of this + + align:start position:0% +something about the development of this + + + align:start position:0% +something about the development of this +new medium by or what was once a new + + align:start position:0% +new medium by or what was once a new + + + align:start position:0% +new medium by or what was once a new +medium by looking at its ancestors and + + align:start position:0% +medium by looking at its ancestors and + + + align:start position:0% +medium by looking at its ancestors and +by looking at the development of other + + align:start position:0% +by looking at the development of other + + + align:start position:0% +by looking at the development of other +of other media by recognizing that + + align:start position:0% +of other media by recognizing that + + + align:start position:0% +of other media by recognizing that +certain kinds of historical comparisons + + align:start position:0% +certain kinds of historical comparisons + + + align:start position:0% +certain kinds of historical comparisons +might be Illuminating granting that even + + align:start position:0% +might be Illuminating granting that even + + + align:start position:0% +might be Illuminating granting that even +granting the notion that that the medium + + align:start position:0% +granting the notion that that the medium + + + align:start position:0% +granting the notion that that the medium +itself might have a history that is + + align:start position:0% +itself might have a history that is + + + align:start position:0% +itself might have a history that is +valuable one aspect of the uh Wasteland + + align:start position:0% +valuable one aspect of the uh Wasteland + + + align:start position:0% +valuable one aspect of the uh Wasteland +mythology that I find I think is still + + align:start position:0% +mythology that I find I think is still + + + align:start position:0% +mythology that I find I think is still +the case and is that people talk about + + align:start position:0% +the case and is that people talk about + + + align:start position:0% +the case and is that people talk about +television as if it is unchanged over + + align:start position:0% +television as if it is unchanged over + + + align:start position:0% +television as if it is unchanged over +its 50-year history they make no or + + align:start position:0% +its 50-year history they make no or + + + align:start position:0% +its 50-year history they make no or +virtually so they they will sometimes + + align:start position:0% +virtually so they they will sometimes + + + align:start position:0% +virtually so they they will sometimes +talk about an alleged golden age of live + + align:start position:0% +talk about an alleged golden age of live + + + align:start position:0% +talk about an alleged golden age of live +television after which everything is + + align:start position:0% +television after which everything is + + + align:start position:0% +television after which everything is +terrible but for the most part they talk + + align:start position:0% +terrible but for the most part they talk + + + align:start position:0% +terrible but for the most part they talk +about television as if it's as if it did + + align:start position:0% +about television as if it's as if it did + + + align:start position:0% +about television as if it's as if it did +not itself have phases and and and and + + align:start position:0% +not itself have phases and and and and + + + align:start position:0% +not itself have phases and and and and +as if the programs of the 90s are + + align:start position:0% +as if the programs of the 90s are + + + align:start position:0% +as if the programs of the 90s are +identical to the programs of the 50s one + + align:start position:0% +identical to the programs of the 50s one + + + align:start position:0% +identical to the programs of the 50s one +can see the same mistake uh even more + + align:start position:0% +can see the same mistake uh even more + + + align:start position:0% +can see the same mistake uh even more +dramatically being made by by the film + + align:start position:0% +dramatically being made by by the film + + + align:start position:0% +dramatically being made by by the film +Scholars and the film historians who + + align:start position:0% +Scholars and the film historians who + + + align:start position:0% +Scholars and the film historians who +really many of whom continue to speak + + align:start position:0% +really many of whom continue to speak + + + align:start position:0% +really many of whom continue to speak +about the movies as if they are a + + align:start position:0% +about the movies as if they are a + + + align:start position:0% +about the movies as if they are a +continuous experience from the silent + + align:start position:0% +continuous experience from the silent + + + align:start position:0% +continuous experience from the silent +era to to the present day when there are + + align:start position:0% +era to to the present day when there are + + + align:start position:0% +era to to the present day when there are +at least two deci Ive moments in which + + align:start position:0% +at least two deci Ive moments in which + + + align:start position:0% +at least two deci Ive moments in which +the movies fundamentally alter their + + align:start position:0% +the movies fundamentally alter their + + + align:start position:0% +the movies fundamentally alter their +relation to the society one is at the + + align:start position:0% +relation to the society one is at the + + + align:start position:0% +relation to the society one is at the +Advent of sound at the end of the 20s + + align:start position:0% +Advent of sound at the end of the 20s + + + align:start position:0% +Advent of sound at the end of the 20s +and the other even more dramatic a + + align:start position:0% +and the other even more dramatic a + + + align:start position:0% +and the other even more dramatic a +fundamental transformation in the + + align:start position:0% +fundamental transformation in the + + + align:start position:0% +fundamental transformation in the +relationship between movies and American + + align:start position:0% +relationship between movies and American + + + align:start position:0% +relationship between movies and American +society occurs with the Advent of + + align:start position:0% +society occurs with the Advent of + + + align:start position:0% +society occurs with the Advent of +television and by by the late 50s or + + align:start position:0% +television and by by the late 50s or + + + align:start position:0% +television and by by the late 50s or +early 60s the relationship between the + + align:start position:0% +early 60s the relationship between the + + + align:start position:0% +early 60s the relationship between the +movie industry in so far as it's still + + align:start position:0% +movie industry in so far as it's still + + + align:start position:0% +movie industry in so far as it's still +an industry and the public is totally + + align:start position:0% +an industry and the public is totally + + + align:start position:0% +an industry and the public is totally +different from what it was and the movie + + align:start position:0% +different from what it was and the movie + + + align:start position:0% +different from what it was and the movie +industry as we've under as we had + + align:start position:0% +industry as we've under as we had + + + align:start position:0% +industry as we've under as we had +understood it before no longer exists + + align:start position:0% +understood it before no longer exists + + + align:start position:0% +understood it before no longer exists +there are no longer vast movie studios + + align:start position:0% +there are no longer vast movie studios + + + align:start position:0% +there are no longer vast movie studios +employing hundreds and sometimes + + align:start position:0% +employing hundreds and sometimes + + + align:start position:0% +employing hundreds and sometimes +thousands of people producing Mass + + align:start position:0% +thousands of people producing Mass + + + align:start position:0% +thousands of people producing Mass +producing stories on a regular basis + + align:start position:0% +producing stories on a regular basis + + + align:start position:0% +producing stories on a regular basis +that that that movie industry is gone + + align:start position:0% +that that that movie industry is gone + + + align:start position:0% +that that that movie industry is gone +the that that idea of the movies is + + align:start position:0% +the that that idea of the movies is + + + align:start position:0% +the that that idea of the movies is +finished and each individual film + + align:start position:0% +finished and each individual film + + + align:start position:0% +finished and each individual film +becomes not only a Blockbuster + + align:start position:0% +becomes not only a Blockbuster + + + align:start position:0% +becomes not only a Blockbuster +experience but the but the creation of + + align:start position:0% +experience but the but the creation of + + + align:start position:0% +experience but the but the creation of +the film The putting together of the + + align:start position:0% +the film The putting together of the + + + align:start position:0% +the film The putting together of the +film becomes an a vast elaborate problem + + align:start position:0% +film becomes an a vast elaborate problem + + + align:start position:0% +film becomes an a vast elaborate problem +in Deal making in which you go and get a + + align:start position:0% +in Deal making in which you go and get a + + + align:start position:0% +in Deal making in which you go and get a +star to who's bankable and you go to and + + align:start position:0% +star to who's bankable and you go to and + + + align:start position:0% +star to who's bankable and you go to and +you go to money backers who will Who + + align:start position:0% +you go to money backers who will Who + + + align:start position:0% +you go to money backers who will Who +will will have in words the production + + align:start position:0% +will will have in words the production + + + align:start position:0% +will will have in words the production +companies are are simply affect Bankers + + align:start position:0% +companies are are simply affect Bankers + + + align:start position:0% +companies are are simply affect Bankers +they're no they're no longer they no + + align:start position:0% +they're no they're no longer they no + + + align:start position:0% +they're no they're no longer they no +longer make a kind of creative + + align:start position:0% +longer make a kind of creative + + + align:start position:0% +longer make a kind of creative +contribution to the movie and the movies + + align:start position:0% +contribution to the movie and the movies + + + align:start position:0% +contribution to the movie and the movies +are a fundamentally different artifact + + align:start position:0% +are a fundamentally different artifact + + + align:start position:0% +are a fundamentally different artifact +they're made differently they have a + + align:start position:0% +they're made differently they have a + + + align:start position:0% +they're made differently they have a +different Their audience has a different + + align:start position:0% +different Their audience has a different + + + align:start position:0% +different Their audience has a different +demographic their relation to the + + align:start position:0% +demographic their relation to the + + + align:start position:0% +demographic their relation to the +society is different and and it is + + align:start position:0% +society is different and and it is + + + align:start position:0% +society is different and and it is +actually an intellectual mistake of a of + + align:start position:0% +actually an intellectual mistake of a of + + + align:start position:0% +actually an intellectual mistake of a of +a very large sort to pretend that the + + align:start position:0% +a very large sort to pretend that the + + + align:start position:0% +a very large sort to pretend that the +movies of the 1980s or 1990s are the + + align:start position:0% +movies of the 1980s or 1990s are the + + + align:start position:0% +movies of the 1980s or 1990s are the +same kind of object uh uh in in in + + align:start position:0% +same kind of object uh uh in in in + + + align:start position:0% +same kind of object uh uh in in in +cultural terms that the movies of the + + align:start position:0% +cultural terms that the movies of the + + + align:start position:0% +cultural terms that the movies of the +30s or the 40s were uh and so this this + + align:start position:0% +30s or the 40s were uh and so this this + + + align:start position:0% +30s or the 40s were uh and so this this +sort of lack of awareness of the of even + + align:start position:0% +sort of lack of awareness of the of even + + + align:start position:0% +sort of lack of awareness of the of even +what we might call the internal history + + align:start position:0% +what we might call the internal history + + + align:start position:0% +what we might call the internal history +of a particular medium especially + + align:start position:0% +of a particular medium especially + + + align:start position:0% +of a particular medium especially +afflicts discourse about television even + + align:start position:0% +afflicts discourse about television even + + + align:start position:0% +afflicts discourse about television even +to this day although some of the + + align:start position:0% +to this day although some of the + + + align:start position:0% +to this day although some of the +readings that I've asked you to do show + + align:start position:0% +readings that I've asked you to do show + + + align:start position:0% +readings that I've asked you to do show +that there is now a nent uh historical + + align:start position:0% +that there is now a nent uh historical + + + align:start position:0% +that there is now a nent uh historical +scholarship being being developed about + + align:start position:0% +scholarship being being developed about + + + align:start position:0% +scholarship being being developed about +television so and and some of it is very + + align:start position:0% +television so and and some of it is very + + + align:start position:0% +television so and and some of it is very +interesting and there's an essay that + + align:start position:0% +interesting and there's an essay that + + + align:start position:0% +interesting and there's an essay that +I've asked you to read um by by a young + + align:start position:0% +I've asked you to read um by by a young + + + align:start position:0% +I've asked you to read um by by a young +scholar named Anderson who uh writes + + align:start position:0% +scholar named Anderson who uh writes + + + align:start position:0% +scholar named Anderson who uh writes +about the relation between Hollywood uh + + align:start position:0% +about the relation between Hollywood uh + + + align:start position:0% +about the relation between Hollywood uh +and and uh Hollywood systems and + + align:start position:0% +and and uh Hollywood systems and + + + align:start position:0% +and and uh Hollywood systems and +television who's done very very + + align:start position:0% +television who's done very very + + + align:start position:0% +television who's done very very +interesting work and the excerpt from + + align:start position:0% +interesting work and the excerpt from + + + align:start position:0% +interesting work and the excerpt from +his book that I've asked you to read + + align:start position:0% +his book that I've asked you to read + + + align:start position:0% +his book that I've asked you to read +That's reprinted in Nukem is about the + + align:start position:0% +That's reprinted in Nukem is about the + + + align:start position:0% +That's reprinted in Nukem is about the +relation between the Disney company and + + align:start position:0% +relation between the Disney company and + + + align:start position:0% +relation between the Disney company and +television very important story about + + align:start position:0% +television very important story about + + + align:start position:0% +television very important story about +the way early 50s television undergos a + + align:start position:0% +the way early 50s television undergos a + + + align:start position:0% +the way early 50s television undergos a +kind of radical transformation once the + + align:start position:0% +kind of radical transformation once the + + + align:start position:0% +kind of radical transformation once the +American movie industry uh acknowledges + + align:start position:0% +American movie industry uh acknowledges + + + align:start position:0% +American movie industry uh acknowledges +the existence of television and begins + + align:start position:0% +the existence of television and begins + + + align:start position:0% +the existence of television and begins +to supply product to it uh and so so + + align:start position:0% +to supply product to it uh and so so + + + align:start position:0% +to supply product to it uh and so so +there is some historical work being done + + align:start position:0% +there is some historical work being done + + + align:start position:0% +there is some historical work being done +by Scholars but in general the discourse + + align:start position:0% +by Scholars but in general the discourse + + + align:start position:0% +by Scholars but in general the discourse +about television in the public Realm + + align:start position:0% +about television in the public Realm + + + align:start position:0% +about television in the public Realm +still continues to be afflicted by this + + align:start position:0% +still continues to be afflicted by this + + + align:start position:0% +still continues to be afflicted by this +ahistoricism it's a double ahistoricism + + align:start position:0% +ahistoricism it's a double ahistoricism + + + align:start position:0% +ahistoricism it's a double ahistoricism +then it's an ahistoricism about the + + align:start position:0% +then it's an ahistoricism about the + + + align:start position:0% +then it's an ahistoricism about the +medium's history and a historicism + + align:start position:0% +medium's history and a historicism + + + align:start position:0% +medium's history and a historicism +because it also doesn't acknowledge the + + align:start position:0% +because it also doesn't acknowledge the + + + align:start position:0% +because it also doesn't acknowledge the +medium's own relation historically to + + align:start position:0% +medium's own relation historically to + + + align:start position:0% +medium's own relation historically to +other media forms so so when we + + align:start position:0% +other media forms so so when we + + + align:start position:0% +other media forms so so when we +acknowledge that it's a cultural + + align:start position:0% +acknowledge that it's a cultural + + + align:start position:0% +acknowledge that it's a cultural +formation one of the things we're + + align:start position:0% +formation one of the things we're + + + align:start position:0% +formation one of the things we're +acknowledging is that it potentially has + + align:start position:0% +acknowledging is that it potentially has + + + align:start position:0% +acknowledging is that it potentially has +a history that it can be compared to + + align:start position:0% +a history that it can be compared to + + + align:start position:0% +a history that it can be compared to +other media that it has its own history + + align:start position:0% +other media that it has its own history + + + align:start position:0% +other media that it has its own history +that we want might want to attend to and + + align:start position:0% +that we want might want to attend to and + + + align:start position:0% +that we want might want to attend to and +and uh there are a couple of ways in + + align:start position:0% +and uh there are a couple of ways in + + + align:start position:0% +and uh there are a couple of ways in +which uh we we we can uh um + + align:start position:0% + + + + align:start position:0% + +um complicate and deepen our + + align:start position:0% +um complicate and deepen our + + + align:start position:0% +um complicate and deepen our +understanding of the notion that + + align:start position:0% +understanding of the notion that + + + align:start position:0% +understanding of the notion that +television is a cultural form or a + + align:start position:0% +television is a cultural form or a + + + align:start position:0% +television is a cultural form or a +cultural formation one of them is to + + align:start position:0% +cultural formation one of them is to + + + align:start position:0% +cultural formation one of them is to +make use of the distinction the + + align:start position:0% +make use of the distinction the + + + align:start position:0% +make use of the distinction the +wonderfully helpful and in many ways + + align:start position:0% +wonderfully helpful and in many ways + + + align:start position:0% +wonderfully helpful and in many ways +still um + + align:start position:0% +still um + + + align:start position:0% +still um +uh FR immensely fruitful Rich + + align:start position:0% +uh FR immensely fruitful Rich + + + align:start position:0% +uh FR immensely fruitful Rich +distinction that James KY uh offers us + + align:start position:0% +distinction that James KY uh offers us + + + align:start position:0% +distinction that James KY uh offers us +in the essay I asked you to read for one + + align:start position:0% +in the essay I asked you to read for one + + + align:start position:0% +in the essay I asked you to read for one +of our one of our classes and I hope + + align:start position:0% +of our one of our classes and I hope + + + align:start position:0% +of our one of our classes and I hope +you've all read it I'm not going to go + + align:start position:0% +you've all read it I'm not going to go + + + align:start position:0% +you've all read it I'm not going to go +through it in detail I want to pull one + + align:start position:0% +through it in detail I want to pull one + + + align:start position:0% +through it in detail I want to pull one +thread of it out and remind you of its + + align:start position:0% +thread of it out and remind you of its + + + align:start position:0% +thread of it out and remind you of its +importance remember the basic + + align:start position:0% +importance remember the basic + + + align:start position:0% +importance remember the basic +distinction that Carrie offers in that + + align:start position:0% +distinction that Carrie offers in that + + + align:start position:0% +distinction that Carrie offers in that +essay and about about the way in which + + align:start position:0% +essay and about about the way in which + + + align:start position:0% +essay and about about the way in which +the idea of communication itself can be + + align:start position:0% +the idea of communication itself can be + + + align:start position:0% +the idea of communication itself can be +understood he says especially in + + align:start position:0% +understood he says especially in + + + align:start position:0% +understood he says especially in +American culture you can actually apply + + align:start position:0% +American culture you can actually apply + + + align:start position:0% +American culture you can actually apply +this to older societies as well there + + align:start position:0% +this to older societies as well there + + + align:start position:0% +this to older societies as well there +have been two in some degree competing + + align:start position:0% +have been two in some degree competing + + + align:start position:0% +have been two in some degree competing +ideas of what communication is and we + + align:start position:0% +ideas of what communication is and we + + + align:start position:0% +ideas of what communication is and we +have tended to fall into the mistake of + + align:start position:0% +have tended to fall into the mistake of + + + align:start position:0% +have tended to fall into the mistake of +imagining that only one of them is + + align:start position:0% +imagining that only one of them is + + + align:start position:0% +imagining that only one of them is +viable and useful in fact it and it + + align:start position:0% +viable and useful in fact it and it + + + align:start position:0% +viable and useful in fact it and it +distorts our understanding of many + + align:start position:0% +distorts our understanding of many + + + align:start position:0% +distorts our understanding of many +communication systems not just + + align:start position:0% +communication systems not just + + + align:start position:0% +communication systems not just +television but many systems of + + align:start position:0% +television but many systems of + + + align:start position:0% +television but many systems of +communication if we don't acknowledge + + align:start position:0% +communication if we don't acknowledge + + + align:start position:0% +communication if we don't acknowledge +both sides of it the the the one one + + align:start position:0% +both sides of it the the the one one + + + align:start position:0% +both sides of it the the the one one +kind of definition or framework or + + align:start position:0% +kind of definition or framework or + + + align:start position:0% +kind of definition or framework or +understanding of a communication system + + align:start position:0% +understanding of a communication system + + + align:start position:0% +understanding of a communication system +is to see communication under the under + + align:start position:0% +is to see communication under the under + + + align:start position:0% +is to see communication under the under +the aspect of what Carrie calls a + + align:start position:0% +the aspect of what Carrie calls a + + + align:start position:0% +the aspect of what Carrie calls a +transmission or a transportation model + + align:start position:0% +transmission or a transportation model + + + align:start position:0% +transmission or a transportation model +right and in fact it's a the the the the + + align:start position:0% +right and in fact it's a the the the the + + + align:start position:0% +right and in fact it's a the the the the +the and the transportation model is in a + + align:start position:0% +the and the transportation model is in a + + + align:start position:0% +the and the transportation model is in a +way it's a very utilitarian + + align:start position:0% +way it's a very utilitarian + + + align:start position:0% +way it's a very utilitarian +understanding of the movement of + + align:start position:0% +understanding of the movement of + + + align:start position:0% +understanding of the movement of +information and the movement of the + + align:start position:0% +information and the movement of the + + + align:start position:0% +information and the movement of the +communication of messages you move you + + align:start position:0% +communication of messages you move you + + + align:start position:0% +communication of messages you move you +move information from one place to to + + align:start position:0% +move information from one place to to + + + align:start position:0% +move information from one place to to +another right the telegraph is a classic + + align:start position:0% +another right the telegraph is a classic + + + align:start position:0% +another right the telegraph is a classic +instance of this of this process and and + + align:start position:0% +instance of this of this process and and + + + align:start position:0% +instance of this of this process and and +and in this idea of uh in this in this + + align:start position:0% +and in this idea of uh in this in this + + + align:start position:0% +and in this idea of uh in this in this +notion of communication uh the + + align:start position:0% +notion of communication uh the + + + align:start position:0% +notion of communication uh the +communication is a commodity who whose + + align:start position:0% +communication is a commodity who whose + + + align:start position:0% +communication is a commodity who whose +use has to who in a very narrow sense is + + align:start position:0% +use has to who in a very narrow sense is + + + align:start position:0% +use has to who in a very narrow sense is +useful for such things as commercial + + align:start position:0% +useful for such things as commercial + + + align:start position:0% +useful for such things as commercial +transactions so if you can if you can + + align:start position:0% +transactions so if you can if you can + + + align:start position:0% +transactions so if you can if you can +and and it's valuable for that reason if + + align:start position:0% +and and it's valuable for that reason if + + + align:start position:0% +and and it's valuable for that reason if +you can and it involves the notion that + + align:start position:0% +you can and it involves the notion that + + + align:start position:0% +you can and it involves the notion that +that the M that that the information is + + align:start position:0% +that the M that that the information is + + + align:start position:0% +that the M that that the information is +valuable only if it it can be only if it + + align:start position:0% +valuable only if it it can be only if it + + + align:start position:0% +valuable only if it it can be only if it +can be transmitted in some way across + + align:start position:0% +can be transmitted in some way across + + + align:start position:0% +can be transmitted in some way across +across a geographical area so that if + + align:start position:0% +across a geographical area so that if + + + align:start position:0% +across a geographical area so that if +you live in San Francisco and you can + + align:start position:0% +you live in San Francisco and you can + + + align:start position:0% +you live in San Francisco and you can +get information about what's going on in + + align:start position:0% +get information about what's going on in + + + align:start position:0% +get information about what's going on in +the stock market you can you can act on + + align:start position:0% +the stock market you can you can act on + + + align:start position:0% +the stock market you can you can act on +that information and if you're cut off + + align:start position:0% +that information and if you're cut off + + + align:start position:0% +that information and if you're cut off +from that information the people in New + + align:start position:0% +from that information the people in New + + + align:start position:0% +from that information the people in New +York have an advantage over you right so + + align:start position:0% +York have an advantage over you right so + + + align:start position:0% +York have an advantage over you right so +so the one notion of communication so + + align:start position:0% +so the one notion of communication so + + + align:start position:0% +so the one notion of communication so +the telegraph was understood incredibly + + align:start position:0% +the telegraph was understood incredibly + + + align:start position:0% +the telegraph was understood incredibly +although for other reasons as well the + + align:start position:0% +although for other reasons as well the + + + align:start position:0% +although for other reasons as well the +telegraph was understood as especially + + align:start position:0% +telegraph was understood as especially + + + align:start position:0% +telegraph was understood as especially +valuable for this for the for the + + align:start position:0% +valuable for this for the for the + + + align:start position:0% +valuable for this for the for the +transmission or the transportation the + + align:start position:0% +transmission or the transportation the + + + align:start position:0% +transmission or the transportation the +movement of financial information + + align:start position:0% +movement of financial information + + + align:start position:0% +movement of financial information +it's also been and such things of course + + align:start position:0% +it's also been and such things of course + + + align:start position:0% +it's also been and such things of course +have been the milit military uh uh + + align:start position:0% +have been the milit military uh uh + + + align:start position:0% +have been the milit military uh uh +institutions of all societies are + + align:start position:0% +institutions of all societies are + + + align:start position:0% +institutions of all societies are +interested in Communications from this + + align:start position:0% +interested in Communications from this + + + align:start position:0% +interested in Communications from this +Transportation perspective for obvious + + align:start position:0% +Transportation perspective for obvious + + + align:start position:0% +Transportation perspective for obvious +reasons it was a the quick communication + + align:start position:0% +reasons it was a the quick communication + + + align:start position:0% +reasons it was a the quick communication +of information uh be uh between between + + align:start position:0% +of information uh be uh between between + + + align:start position:0% +of information uh be uh between between +units or from or from command + + align:start position:0% +units or from or from command + + + align:start position:0% +units or from or from command +headquarters to people on the front is + + align:start position:0% +headquarters to people on the front is + + + align:start position:0% +headquarters to people on the front is +crucial for the operations of the + + align:start position:0% +crucial for the operations of the + + + align:start position:0% +crucial for the operations of the +military and and and uh uh one and and + + align:start position:0% +military and and and uh uh one and and + + + align:start position:0% +military and and and uh uh one and and +the one doesn't have to sort of narrow + + align:start position:0% +the one doesn't have to sort of narrow + + + align:start position:0% +the one doesn't have to sort of narrow +this notion of of a transmission view of + + align:start position:0% +this notion of of a transmission view of + + + align:start position:0% +this notion of of a transmission view of +communication + + align:start position:0% +communication + + + align:start position:0% +communication +only to the mil to Military and and + + align:start position:0% +only to the mil to Military and and + + + align:start position:0% +only to the mil to Military and and +economic information other the the the + + align:start position:0% +economic information other the the the + + + align:start position:0% +economic information other the the the +the movement in society of other more + + align:start position:0% +the movement in society of other more + + + align:start position:0% +the movement in society of other more +generalized forms of information is + + align:start position:0% +generalized forms of information is + + + align:start position:0% +generalized forms of information is +partly embodied in or captured by a + + align:start position:0% +partly embodied in or captured by a + + + align:start position:0% +partly embodied in or captured by a +transmission or Transportation model but + + align:start position:0% +transmission or Transportation model but + + + align:start position:0% +transmission or Transportation model but +but car's crucial point is that this is + + align:start position:0% +but car's crucial point is that this is + + + align:start position:0% +but car's crucial point is that this is +an essentially + + align:start position:0% +an essentially + + + align:start position:0% +an essentially +utilitarian uh and and functional use uh + + align:start position:0% +utilitarian uh and and functional use uh + + + align:start position:0% +utilitarian uh and and functional use uh +understanding of what of of of of what + + align:start position:0% +understanding of what of of of of what + + + align:start position:0% +understanding of what of of of of what +message what the communication of + + align:start position:0% +message what the communication of + + + align:start position:0% +message what the communication of +messages is used for how they function + + align:start position:0% +messages is used for how they function + + + align:start position:0% +messages is used for how they function +in society what Carrie suggests is that + + align:start position:0% +in society what Carrie suggests is that + + + align:start position:0% +in society what Carrie suggests is that +there's another way of understanding + + align:start position:0% +there's another way of understanding + + + align:start position:0% +there's another way of understanding +communication not not one that's better + + align:start position:0% +communication not not one that's better + + + align:start position:0% +communication not not one that's better +but one that's different and that and + + align:start position:0% +but one that's different and that and + + + align:start position:0% +but one that's different and that and +that in fact explains aspects of the way + + align:start position:0% +that in fact explains aspects of the way + + + align:start position:0% +that in fact explains aspects of the way +communication systems and the experience + + align:start position:0% +communication systems and the experience + + + align:start position:0% +communication systems and the experience +of communication is used in all cultures + + align:start position:0% +of communication is used in all cultures + + + align:start position:0% +of communication is used in all cultures +that the transmission view of + + align:start position:0% +that the transmission view of + + + align:start position:0% +that the transmission view of +communication does not allow and that's + + align:start position:0% +communication does not allow and that's + + + align:start position:0% +communication does not allow and that's +what he calls a ritual view of + + align:start position:0% +what he calls a ritual view of + + + align:start position:0% +what he calls a ritual view of +communication and under the ritual + + align:start position:0% +communication and under the ritual + + + align:start 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+ + align:start position:0% +information not to tell you so not not +to provide you with news not to inform + + align:start position:0% +to provide you with news not to inform + + + align:start position:0% +to provide you with news not to inform +you of anything but to do some but to do + + align:start position:0% +you of anything but to do some but to do + + + align:start position:0% +you of anything but to do some but to do +something else uh it's to it's to engage + + align:start position:0% +something else uh it's to it's to engage + + + align:start position:0% +something else uh it's to it's to engage +it's it's to help the society engage in + + align:start position:0% +it's it's to help the society engage in + + + align:start position:0% +it's it's to help the society engage in +various ritualized processes of + + align:start position:0% +various ritualized processes of + + + align:start position:0% +various ritualized processes of +sharing and self-de so that when a group + + align:start position:0% +sharing and self-de so that when a group + + + align:start position:0% +sharing and self-de so that when a group +when and so that and in fact Carrie + + align:start position:0% +when and so that and in fact Carrie + + + align:start position:0% +when and so that and in fact Carrie +explicitly suggests that this ritual + + align:start position:0% +explicitly suggests that this ritual + + + align:start position:0% +explicitly suggests that this ritual +view of communication uh is connected uh + + align:start position:0% +view of communication uh is connected uh + + + align:start position:0% +view of communication uh is connected uh +has its root in religious experience + + align:start position:0% +has its root in religious experience + + + align:start position:0% +has its root in religious experience +when you gather together in a in a + + align:start position:0% +when you gather together in a in a + + + align:start position:0% +when you gather together in a in a +church service uh it's not as if + + align:start position:0% +church service uh it's not as if + + + align:start position:0% +church service uh it's not as if +specific information is being uh + + align:start position:0% +specific information is being uh + + + align:start position:0% +specific information is being uh +imparted to you but the but the + + align:start position:0% +imparted to you but the but the + + + align:start position:0% +imparted to you but the but the +experience but the experience of the of + + align:start position:0% +experience but the experience of the of + + + align:start position:0% +experience but the experience of the of +the religious observant helps to + + align:start position:0% +the religious observant helps to + + + align:start position:0% +the religious observant helps to +establish and create and maintain + + align:start position:0% +establish and create and maintain + + + align:start position:0% +establish and create and maintain +Notions of connection with your with + + align:start position:0% +Notions of connection with your with + + + align:start position:0% +Notions of connection with your with +your fellow communicants it helps to it + + align:start position:0% +your fellow communicants it helps to it + + + align:start position:0% +your fellow communicants it helps to it +it helps to it helps in a sense to + + align:start position:0% +it helps to it helps in a sense to + + + align:start position:0% +it helps to it helps in a sense to +create and maintain the community that + + align:start position:0% +create and maintain the community that + + + align:start position:0% +create and maintain the community that +comes into the uh uh Cathedral or the + + align:start position:0% +comes into the uh uh Cathedral or the + + + align:start position:0% +comes into the uh uh Cathedral or the +church or the synagogue or the mosque + + align:start position:0% +church or the synagogue or the mosque + + + align:start position:0% +church or the synagogue or the mosque +for the religion service right and and + + align:start position:0% +for the religion service right and and + + + align:start position:0% +for the religion service right and and +and and Carrie is in many ways himself + + align:start position:0% +and and Carrie is in many ways himself + + + align:start position:0% +and and Carrie is in many ways himself +a a secretly religious person he pretend + + align:start position:0% +a a secretly religious person he pretend + + + align:start position:0% +a a secretly religious person he pretend +he's a good friend of mine I've + + align:start position:0% +he's a good friend of mine I've + + + align:start position:0% +he's a good friend of mine I've +sometimes had him come to MIT and + + align:start position:0% +sometimes had him come to MIT and + + + align:start position:0% +sometimes had him come to MIT and +lecture uh and he's he's been a um an + + align:start position:0% +lecture uh and he's he's been a um an + + + align:start position:0% +lecture uh and he's he's been a um an +influence on my own on my own uh + + align:start position:0% +influence on my own on my own uh + + + align:start position:0% +influence on my own on my own uh +willingness to talk about media that in + + align:start position:0% +willingness to talk about media that in + + + align:start position:0% +willingness to talk about media that in +the early days when I first began to + + align:start position:0% +the early days when I first began to + + + align:start position:0% +the early days when I first began to +talk about them uh put me under a cloud + + align:start position:0% +talk about them uh put me under a cloud + + + align:start position:0% +talk about them uh put me under a cloud +in Yale's English Department uh and uh + + align:start position:0% +in Yale's English Department uh and uh + + + align:start position:0% +in Yale's English Department uh and uh +Carrie is himself a kind of closet + + align:start position:0% +Carrie is himself a kind of closet + + + align:start position:0% +Carrie is himself a kind of closet +religious I mean he's a he's an he's an + + align:start position:0% +religious I mean he's a he's an he's an + + + align:start position:0% +religious I mean he's a he's an he's an +Irish Catholic from Providence Rhode + + align:start position:0% +Irish Catholic from Providence Rhode + + + align:start position:0% +Irish Catholic from Providence Rhode +Island uh although he's a lapsed + + align:start position:0% +Island uh although he's a lapsed + + + align:start position:0% +Island uh although he's a lapsed +Catholic he's he he has deeply religious + + align:start position:0% +Catholic he's he he has deeply religious + + + align:start position:0% +Catholic he's he he has deeply religious +inclinations and I think that's one of + + align:start position:0% +inclinations and I think that's one of + + + align:start position:0% +inclinations and I think that's one of +the 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+society where it's much easier to see +this ritualized function uh than we + + align:start position:0% +this ritualized function uh than we + + + align:start position:0% +this ritualized function uh than we +might of television as for example than + + align:start position:0% +might of television as for example than + + + align:start position:0% +might of television as for example than +we might otherwise have done in any case + + align:start position:0% +we might otherwise have done in any case + + + align:start position:0% +we might otherwise have done in any case +to uh the the notion + + align:start position:0% +to uh the the notion + + + align:start position:0% +to uh the the notion +so the notion of the the ritual + + align:start position:0% +so the notion of the the ritual + + + align:start position:0% +so the notion of the the ritual +definition or the ritual idea the ritual + + align:start position:0% +definition or the ritual idea the ritual + + + align:start position:0% +definition or the ritual idea the ritual +framework for understanding + + align:start position:0% +framework for understanding + + + align:start position:0% +framework for understanding +communication systems suggests that we + + align:start position:0% +communication systems suggests that we + + + align:start position:0% +communication systems suggests that we +don't read newspapers to get information + + align:start position:0% +don't read newspapers to get information + + + align:start position:0% +don't read newspapers to get information +or we don't M only read newspapers to + + align:start position:0% +or we don't M only read newspapers to + + + align:start position:0% +or we don't M only read newspapers to +get information we read newspapers to be + + align:start position:0% +get information we read newspapers to be + + + align:start position:0% +get information we read newspapers to be +connected to our fellow citizens we read + + align:start position:0% +connected to our fellow citizens we read + + + align:start position:0% +connected to our fellow citizens we read +newspapers because the reading of the + + align:start position:0% +newspapers because the reading of the + + + align:start position:0% +newspapers because the reading of the +newspaper creates a a a a not just of + + align:start position:0% +newspaper creates a a a a not just of + + + align:start position:0% +newspaper creates a a a a not just of +one story but the regular reading of the + + align:start position:0% +one story but the regular reading of the + + + align:start position:0% +one story but the regular reading of the +newspaper creates an experience wherein + + align:start position:0% +newspaper creates an experience wherein + + + align:start position:0% +newspaper creates an experience wherein +what the newspaper what the newspaper + + align:start position:0% +what the newspaper what the newspaper + + + align:start position:0% +what the newspaper what the newspaper +stories taken together do is is is + + align:start position:0% +stories taken together do is is is + + + align:start position:0% +stories taken together do is is is +provide us with a kind of broad + + align:start position:0% +provide us with a kind of broad + + + align:start position:0% +provide us with a kind of broad +understanding of the nature of our + + align:start position:0% +understanding of the nature of our + + + align:start position:0% +understanding of the nature of our +society it defines the belief system or + + align:start position:0% +society it defines the belief system or + + + align:start position:0% +society it defines the belief system or +the value system of our society and by + + align:start position:0% +the value system of our society and by + + + align:start position:0% +the value system of our society and by +reading the newspaper every day we + + align:start position:0% +reading the newspaper every day we + + + align:start position:0% +reading the newspaper every day we +participate in a process that's ongoing + + align:start position:0% +participate in a process that's ongoing + + + align:start position:0% +participate in a process that's ongoing +it's not a sing it's not it's not a what + + align:start position:0% +it's not a sing it's not it's not a what + + + align:start position:0% +it's not a sing it's not it's not a what +that the the creation of community + + align:start position:0% +that the the creation of community + + + align:start position:0% +that the the creation of community +societies and communities are not + + align:start position:0% +societies and communities are not + + + align:start position:0% +societies and communities are not +created and then the job is done + + align:start position:0% +created and then the job is done + + + align:start position:0% +created and then the job is done +communities are maintained and and and + + align:start position:0% +communities are maintained and and and + + + align:start position:0% +communities are maintained and and and +and and kept in uh uh uh uh uh they they + + align:start position:0% +and and kept in uh uh uh uh uh they they + + + align:start position:0% +and and kept in uh uh uh uh uh they they +are are maintained and repaired right + + align:start position:0% +are are maintained and repaired right + + + align:start position:0% +are are maintained and repaired right +sometimes dangerous things happen + + align:start position:0% +sometimes dangerous things happen + + + align:start position:0% +sometimes dangerous things happen +terrible things happen to societies + + align:start position:0% +terrible things happen to societies + + + align:start position:0% +terrible things happen to societies +right the World Trade Center catastrophe + + align:start position:0% +right the World Trade Center catastrophe + + + align:start position:0% +right the World Trade Center catastrophe +is a the most immediate obvious example + + align:start position:0% +is a the most immediate obvious example + + + align:start position:0% +is a the most immediate obvious example +what do you do when that happens what + + align:start position:0% +what do you do when that happens what + + + align:start position:0% +what do you do when that happens what +does the society do what does one of the + + align:start position:0% +does the society do what does one of the + + + align:start position:0% +does the society do what does one of the +things you do is you all begin to watch + + align:start position:0% +things you do is you all begin to watch + + + align:start position:0% +things you do is you all begin to watch +television and and when we're watching + + align:start position:0% +television and and when we're watching + + + align:start position:0% +television and and when we're watching +television and watching the planes + + align:start position:0% +television and watching the planes + + + align:start position:0% +television and watching the planes +hitting the World Trade Center again and + + align:start position:0% +hitting the World Trade Center again and + + + align:start position:0% +hitting the World Trade Center again and +again and again and again we're not + + align:start position:0% +again and again and again we're not + + + align:start position:0% +again and again and again we're not +getting information what's happening + + align:start position:0% +getting information what's happening + + + align:start position:0% +getting information what's happening +there some kind of ritualized experience + + align:start position:0% +there some kind of ritualized experience + + + align:start position:0% +there some kind of ritualized experience +of sharing and reparation is going on in + + align:start position:0% +of sharing and reparation is going on in + + + align:start position:0% +of sharing and reparation is going on in +which we're trying to as a whole the + + align:start position:0% +which we're trying to as a whole the + + + align:start position:0% +which we're trying to as a whole the +society as a whole is trying to make + + align:start position:0% +society as a whole is trying to make + + + align:start position:0% +society as a whole is trying to make +sense of right uh an horrific rent in + + align:start position:0% +sense of right uh an horrific rent in + + + align:start position:0% +sense of right uh an horrific rent in +its fabric the community has been + + align:start position:0% +its fabric the community has been + + + align:start position:0% +its fabric the community has been +disrupted and terrified by what's by by + + align:start position:0% +disrupted and terrified by what's by by + + + align:start position:0% +disrupted and terrified by what's by by +what's happened here and and one of the + + align:start position:0% +what's happened here and and one of the + + + align:start position:0% +what's happened here and and one of the +functions of all media one of the + + align:start position:0% +functions of all media one of the + + + align:start position:0% +functions of all media one of the +functions of communication as a human + + align:start position:0% +functions of communication as a human + + + align:start position:0% +functions of communication as a human +activity Carrie says is to repair that + + align:start position:0% +activity Carrie says is to repair that + + + align:start position:0% +activity Carrie says is to repair that +damage is to ritualize the experience is + + align:start position:0% +damage is to ritualize the experience is + + + align:start position:0% +damage is to ritualize the experience is +to create a sense of sharing the social + + align:start position:0% +to create a sense of sharing the social + + + align:start position:0% +to create a sense of sharing the social +fabric is rent and we maintain it and + + align:start position:0% +fabric is rent and we maintain it and + + + align:start position:0% +fabric is rent and we maintain it and +repair it by talking about it and in + + align:start position:0% +repair it by talking about it and in + + + align:start position:0% +repair it by talking about it and in +fact talk is a form of communication + + align:start position:0% +fact talk is a form of communication + + + align:start position:0% +fact talk is a form of communication +right and the greatest novel ever + + align:start position:0% +right and the greatest novel ever + + + align:start position:0% +right and the greatest novel ever +written also the very first novel ever + + align:start position:0% +written also the very first novel ever + + + align:start position:0% +written also the very first novel ever +written D kote is about the the + + align:start position:0% +written D kote is about the the + + + align:start position:0% +written D kote is about the the +reparation powers of conversation again + + align:start position:0% +reparation powers of conversation again + + + align:start position:0% +reparation powers of conversation again +and again in that novel kiot rides into + + align:start position:0% +and again in that novel kiot rides into + + + align:start position:0% +and again in that novel kiot rides into +some difficulty is knocked on his back + + align:start position:0% +some difficulty is knocked on his back + + + align:start position:0% +some difficulty is knocked on his back +is lying bleeding on the ground and + + align:start position:0% +is lying bleeding on the ground and + + + align:start position:0% +is lying bleeding on the ground and +Sancho comes over to him and says well + + align:start position:0% +Sancho comes over to him and says well + + + align:start position:0% +Sancho comes over to him and says well +and then and often often Sancho Panza + + align:start position:0% +and then and often often Sancho Panza + + + align:start position:0% +and then and often often Sancho Panza +his his his realistic counterpart right + + align:start position:0% +his his his realistic counterpart right + + + align:start position:0% +his his his realistic counterpart right +the ideal and the real riding together + + align:start position:0% +the ideal and the real riding together + + + align:start position:0% +the ideal and the real riding together +into the world the material and the + + align:start position:0% +into the world the material and the + + + align:start position:0% +into the world the material and the +spiritual join together as they ride + + align:start position:0% +spiritual join together as they ride + + + align:start position:0% +spiritual join together as they ride +into the uh into experience uh the the + + align:start position:0% +into the uh into experience uh the the + + + align:start position:0% +into the uh into experience uh the the +realistic side of the of the equation + + align:start position:0% +realistic side of the of the equation + + + align:start position:0% +realistic side of the of the equation +says well it's never so dark as before + + align:start position:0% +says well it's never so dark as before + + + align:start position:0% +says well it's never so dark as before +the dawn and he repeats all these boring + + align:start position:0% +the dawn and he repeats all these boring + + + align:start position:0% +the dawn and he repeats all these boring +stupid cliches but and and and kiot will + + align:start position:0% +stupid cliches but and and and kiot will + + + align:start position:0% +stupid cliches but and and and kiot will +sometimes respond oh Sono you bore me to + + align:start position:0% +sometimes respond oh Sono you bore me to + + + align:start position:0% +sometimes respond oh Sono you bore me to +death with your stupid cliche the very + + align:start position:0% +death with your stupid cliche the very + + + align:start position:0% +death with your stupid cliche the very +fact that they talk makes makes the + + align:start position:0% +fact that they talk makes makes the + + + align:start position:0% +fact that they talk makes makes the +bleeding from his ears less terrible + + align:start position:0% +bleeding from his ears less terrible + + + align:start position:0% +bleeding from his ears less terrible +right conversation itself in that novel + + align:start position:0% +right conversation itself in that novel + + + align:start position:0% +right conversation itself in that novel +and in our in our lives is a form of + + align:start position:0% +and in our in our lives is a form of + + + align:start position:0% +and in our in our lives is a form of +reparation so it's a it's a brilliant + + align:start position:0% +reparation so it's a it's a brilliant + + + align:start position:0% +reparation so it's a it's a brilliant +and and obviously right way of + + align:start position:0% +and and obviously right way of + + + align:start position:0% +and and obviously right way of +understanding what communication is we + + align:start position:0% +understanding what communication is we + + + align:start position:0% +understanding what communication is we +we don't so so we don't read the + + align:start position:0% +we don't so so we don't read the + + + align:start position:0% +we don't so so we don't read the +newspapers we don't watch we don't watch + + align:start position:0% +newspapers we don't watch we don't watch + + + align:start position:0% +newspapers we don't watch we don't watch +NYPD Blue we don't even watch the news + + align:start position:0% +NYPD Blue we don't even watch the news + + + align:start position:0% +NYPD Blue we don't even watch the news +on television uh necessarily or + + align:start position:0% +on television uh necessarily or + + + align:start position:0% +on television uh necessarily or +primarily in order to find something out + + align:start position:0% +primarily in order to find something out + + + align:start position:0% +primarily in order to find something out +right a transmission a a a functional + + align:start position:0% +right a transmission a a a functional + + + align:start position:0% +right a transmission a a a functional +use of the medium we watch it in part to + + align:start position:0% +use of the medium we watch it in part to + + + align:start position:0% +use of the medium we watch it in part to +share with our fellow citizens an + + align:start position:0% +share with our fellow citizens an + + + align:start position:0% +share with our fellow citizens an +experience that helps us in the process + + align:start position:0% +experience that helps us in the process + + + align:start position:0% +experience that helps us in the process +in the in the continuous process that we + + align:start position:0% +in the in the continuous process that we + + + align:start position:0% +in the in the continuous process that we +engage in in doing so uh that helps us + + align:start position:0% +engage in in doing so uh that helps us + + + align:start position:0% +engage in in doing so uh that helps us +to repair and recreate and rehearse the + + align:start position:0% +to repair and recreate and rehearse the + + + align:start position:0% +to repair and recreate and rehearse the +nature of our society that Society + + align:start position:0% +nature of our society that Society + + + align:start position:0% +nature of our society that Society +itself is a continuous process of this + + align:start position:0% +itself is a continuous process of this + + + align:start position:0% +itself is a continuous process of this +sort of reparation and maintenance work + + align:start position:0% +sort of reparation and maintenance work + + + align:start position:0% +sort of reparation and maintenance work +that communication systems perform for + + align:start position:0% +that communication systems perform for + + + align:start position:0% +that communication systems perform for +us the anthropological or sociological + + align:start position:0% +us the anthropological or sociological + + + align:start position:0% +us the anthropological or sociological +function of communication systems under + + align:start position:0% +function of communication systems under + + + align:start position:0% +function of communication systems under +the ritual view is this maintenance and + + align:start position:0% +the ritual view is this maintenance and + + + align:start position:0% +the ritual view is this maintenance and +reparation of the social fabric yes + + align:start position:0% +reparation of the social fabric yes + + + align:start position:0% +reparation of the social fabric yes +question uh the made you wait so long + + align:start position:0% +question uh the made you wait so long + + + align:start position:0% +question uh the made you wait so long +that's okay the the one thing I don't + + align:start position:0% +that's okay the the one thing I don't + + + align:start position:0% +that's okay the the one thing I don't +understand when I was reading it is if + + align:start position:0% +understand when I was reading it is if + + + align:start position:0% +understand when I was reading it is if +like I understand both views but what + + align:start position:0% +like I understand both views but what + + + align:start position:0% +like I understand both views but what +confuses me is that the ritual model + + align:start position:0% +confuses me is that the ritual model + + + align:start position:0% +confuses me is that the ritual model +seems like just an extension of the + + align:start position:0% +seems like just an extension of the + + + align:start position:0% +seems like just an extension of the +transmission model like you can't have + + align:start position:0% +transmission model like you can't have + + + align:start position:0% +transmission model like you can't have +like I I don't know how to explain it + + align:start position:0% +like I I don't know how to explain it + + + align:start position:0% +like I I don't know how to explain it +but even in the ritual model if we're + + align:start position:0% +but even in the ritual model if we're + + + align:start position:0% +but even in the ritual model if we're +all sitting around watching the news + + align:start position:0% +all sitting around watching the news + + + align:start position:0% +all sitting around watching the news +simply to have a common uh a common + + align:start position:0% +simply to have a common uh a common + + + align:start position:0% +simply to have a common uh a common +sense you know state of mind watching + + align:start position:0% +sense you know state of mind watching + + + align:start position:0% +sense you know state of mind watching +the planes drop over and over again uh + + align:start position:0% +the planes drop over and over again uh + + + align:start position:0% +the planes drop over and over again uh +we're still receiving that information + + align:start position:0% +we're still receiving that information + + + align:start position:0% +we're still receiving that information +and like by by receiving the information + + align:start position:0% +and like by by receiving the information + + + align:start position:0% +and like by by receiving the information +it is because of the information that we + + align:start position:0% +it is because of the information that we + + + align:start position:0% +it is because of the information that we +are uh connected on the same level so + + align:start position:0% +are uh connected on the same level so + + + align:start position:0% +are uh connected on the same level so +how is the ritual model significantly + + align:start position:0% +how is the ritual model significantly + + + align:start position:0% +how is the ritual model significantly +different than the transmission model + + align:start position:0% +different than the transmission model + + + align:start position:0% +different than the transmission model +and how can we only look at how can how + + align:start position:0% +and how can we only look at how can how + + + align:start position:0% +and how can we only look at how can how +can one be dominant over the other okay + + align:start position:0% +can one be dominant over the other okay + + + align:start position:0% +can one be dominant over the other okay +well I don't think it's a question of + + align:start position:0% +well I don't think it's a question of + + + align:start position:0% +well I don't think it's a question of +one dominating inica they're sort of + + align:start position:0% +one dominating inica they're sort of + + + align:start position:0% +one dominating inica they're sort of +competing ways of understanding what + + align:start position:0% +competing ways of understanding what + + + align:start position:0% +competing ways of understanding what +communication is but I think there are a + + align:start position:0% +communication is but I think there are a + + + align:start position:0% +communication is but I think there are a +couple of answers to what you're saying + + align:start position:0% +couple of answers to what you're saying + + + align:start position:0% +couple of answers to what you're saying +one is that you're you're you're not + + align:start position:0% +one is that you're you're you're not + + + align:start position:0% +one is that you're you're you're not +problematizing the word information + + align:start position:0% +problematizing the word information + + + align:start position:0% +problematizing the word information +enough what makes you think that what + + align:start position:0% +enough what makes you think that what + + + align:start position:0% +enough what makes you think that what +you're getting is actually always + + align:start position:0% +you're getting is actually always + + + align:start position:0% +you're getting is actually always +information in the case of the images of + + align:start position:0% +information in the case of the images of + + + align:start position:0% +information in the case of the images of +the planes crashing into the tower I + + align:start position:0% +the planes crashing into the tower I + + + align:start position:0% +the planes crashing into the tower I +suppose there is a level of of of + + align:start position:0% +suppose there is a level of of of + + + align:start position:0% +suppose there is a level of of of +information involved but suppose we + + align:start position:0% +information involved but suppose we + + + align:start position:0% +information involved but suppose we +change things and and suppose we're + + align:start position:0% +change things and and suppose we're + + + align:start position:0% +change things and and suppose we're +talking about uh the watching of a + + align:start position:0% +talking about uh the watching of a + + + align:start position:0% +talking about uh the watching of a +situation comedy uh this the situation + + align:start position:0% +situation comedy uh this the situation + + + align:start position:0% +situation comedy uh this the situation +comedy is a fantasy what's happening and + + align:start position:0% +comedy is a fantasy what's happening and + + + align:start position:0% +comedy is a fantasy what's happening and +in fact even the even the account of + + align:start position:0% +in fact even the even the account of + + + align:start position:0% +in fact even the even the account of +family life that television may be + + align:start position:0% +family life that television may be + + + align:start position:0% +family life that television may be +provide that you may be get provided by + + align:start position:0% +provide that you may be get provided by + + + align:start position:0% +provide that you may be get provided by +is not in fact is not in a narrow or + + align:start position:0% +is not in fact is not in a narrow or + + + align:start position:0% +is not in fact is not in a narrow or +objective sense an a reality it's a + + align:start position:0% +objective sense an a reality it's a + + + align:start position:0% +objective sense an a reality it's a +construction an interpretation right so + + align:start position:0% +construction an interpretation right so + + + align:start position:0% +construction an interpretation right so +so so and and one could and of course + + align:start position:0% +so so and and one could and of course + + + align:start position:0% +so so and and one could and of course +one could argue that news itself that + + align:start position:0% +one could argue that news itself that + + + align:start position:0% +one could argue that news itself that +what we call information is really a + + align:start position:0% +what we call information is really a + + + align:start position:0% +what we call information is really a +kind of construction it's one way of + + align:start position:0% +kind of construction it's one way of + + + align:start position:0% +kind of construction it's one way of +understanding uh What uh um uh + + align:start position:0% +understanding uh What uh um uh + + + align:start position:0% +understanding uh What uh um uh +particular details so that so that the + + align:start position:0% +particular details so that so that the + + + align:start position:0% +particular details so that so that the +narratives that and it the information + + align:start position:0% +narratives that and it the information + + + align:start position:0% +narratives that and it the information +that we get when the planes crash into + + align:start position:0% +that we get when the planes crash into + + + align:start position:0% +that we get when the planes crash into +the world Trade Center uh isn't simply + + align:start position:0% +the world Trade Center uh isn't simply + + + align:start position:0% +the world Trade Center uh isn't simply +the visual image imagine how someone how + + align:start position:0% +the visual image imagine how someone how + + + align:start position:0% +the visual image imagine how someone how +a member of the + + align:start position:0% +a member of the + + + align:start position:0% +a member of the +Hamas right the the Palestinian + + align:start position:0% +Hamas right the the Palestinian + + + align:start position:0% +Hamas right the the Palestinian +organization that + + align:start position:0% +organization that + + + align:start position:0% +organization that +we in America and the Israelis label a + + align:start position:0% +we in America and the Israelis label a + + + align:start position:0% +we in America and the Israelis label a +terrorist + + align:start position:0% +terrorist + + + align:start position:0% +terrorist +organization I'm being too neat I think + + align:start position:0% +organization I'm being too neat I think + + + align:start position:0% +organization I'm being too neat I think +it is a terrorist organization by me + + align:start position:0% +it is a terrorist organization by me + + + align:start position:0% +it is a terrorist organization by me +it's a terrorist organization but but + + align:start position:0% +it's a terrorist organization but but + + + align:start position:0% +it's a terrorist organization but but +imagine the Hamas watching that and + + align:start position:0% +imagine the Hamas watching that and + + + align:start position:0% +imagine the Hamas watching that and +imagine a commentator from the Hamas + + align:start position:0% +imagine a commentator from the Hamas + + + align:start position:0% +imagine a commentator from the Hamas +commenting on it or imagine the Syrian + + align:start position:0% +commenting on it or imagine the Syrian + + + align:start position:0% +commenting on it or imagine the Syrian +newspaper that Carri an editorial the + + align:start position:0% +newspaper that Carri an editorial the + + + align:start position:0% +newspaper that Carri an editorial the +day after the uh World Trade Center uh + + align:start position:0% +day after the uh World Trade Center uh + + + align:start position:0% +day after the uh World Trade Center uh +catastrophe saying uh the days of + + align:start position:0% +catastrophe saying uh the days of + + + align:start position:0% +catastrophe saying uh the days of +American hegemony are over and that + + align:start position:0% +American hegemony are over and that + + + align:start position:0% +American hegemony are over and that +finally America is no the America's in + + align:start position:0% +finally America is no the America's in + + + align:start position:0% +finally America is no the America's in +the Twilight of its power okay on the + + align:start position:0% +the Twilight of its power okay on the + + + align:start position:0% +the Twilight of its power okay on the +basis of the World Trade Center so that + + align:start position:0% +basis of the World Trade Center so that + + + align:start position:0% +basis of the World Trade Center so that +uh the the meaning the meaning of those + + align:start position:0% +uh the the meaning the meaning of those + + + align:start position:0% +uh the the meaning the meaning of those +planes crashing into the way World Trade + + align:start position:0% +planes crashing into the way World Trade + + + align:start position:0% +planes crashing into the way World Trade +Center is is not obvious it depends on + + align:start position:0% +Center is is not obvious it depends on + + + align:start position:0% +Center is is not obvious it depends on +it depends on the constructions that are + + align:start position:0% +it depends on the constructions that are + + + align:start position:0% +it depends on the constructions that are +put upon those events by the narratives + + align:start position:0% +put upon those events by the narratives + + + align:start position:0% +put upon those events by the narratives +that surround it and those narratives + + align:start position:0% +that surround it and those narratives + + + align:start position:0% +that surround it and those narratives +are going to differ from one kind of + + align:start position:0% +are going to differ from one kind of + + + align:start position:0% +are going to differ from one kind of +culture and one one ideological Center + + align:start position:0% +culture and one one ideological Center + + + align:start position:0% +culture and one one ideological Center +to another the process of doing that of + + align:start position:0% +to another the process of doing that of + + + align:start position:0% +to another the process of doing that of +of of of surrounding the event with + + align:start position:0% +of of of surrounding the event with + + + align:start position:0% +of of of surrounding the event with +commentary with talk with with with + + align:start position:0% +commentary with talk with with with + + + align:start position:0% +commentary with talk with with with +constructions right of constructing the + + align:start position:0% +constructions right of constructing the + + + align:start position:0% +constructions right of constructing the +meaning of those of those events is + + align:start position:0% +meaning of those of those events is + + + align:start position:0% +meaning of those of those events is +partly even maybe largely a ritualizing + + align:start position:0% +partly even maybe largely a ritualizing + + + align:start position:0% +partly even maybe largely a ritualizing +process and it may not really have to do + + align:start position:0% +process and it may not really have to do + + + align:start position:0% +process and it may not really have to do +with anything that we might label in + + align:start position:0% +with anything that we might label in + + + align:start position:0% +with anything that we might label in +quotes objective I'm not sure that there + + align:start position:0% +quotes objective I'm not sure that there + + + align:start position:0% +quotes objective I'm not sure that there +is such a such a thing but in other + + align:start position:0% +is such a such a thing but in other + + + align:start position:0% +is such a such a thing but in other +words the the because because because + + align:start position:0% +words the the because because because + + + align:start position:0% +words the the because because because +one might say that there is no single + + align:start position:0% +one might say that there is no single + + + align:start position:0% +one might say that there is no single +meaning to such a in and and and and + + align:start position:0% +meaning to such a in and and and and + + + align:start position:0% +meaning to such a in and and and and +decisive event that that the meanings of + + align:start position:0% +decisive event that that the meanings of + + + align:start position:0% +decisive event that that the meanings of +the the meanings of that event are are + + align:start position:0% +the the meanings of that event are are + + + align:start position:0% +the the meanings of that event are are +are are are non-existent until they're + + align:start position:0% +are are are non-existent until they're + + + align:start position:0% +are are are non-existent until they're +surrounded by varieties of + + align:start position:0% +surrounded by varieties of + + + align:start position:0% +surrounded by varieties of +interpretation until until particular Co + + align:start position:0% +interpretation until until particular Co + + + align:start position:0% +interpretation until until particular Co +and in fact we we know for sure that + + align:start position:0% +and in fact we we know for sure that + + + align:start position:0% +and in fact we we know for sure that +even the way the European press or the + + align:start position:0% +even the way the European press or the + + + align:start position:0% +even the way the European press or the +way the European television programs w + + align:start position:0% +way the European television programs w + + + align:start position:0% +way the European television programs w +television commentators would have + + align:start position:0% +television commentators would have + + + align:start position:0% +television commentators would have +responded to that is different from the + + align:start position:0% +responded to that is different from the + + + align:start position:0% +responded to that is different from the +way the American networks responded to + + align:start position:0% +way the American networks responded to + + + align:start position:0% +way the American networks responded to +it right so that that so that's part of + + align:start position:0% +it right so that that so that's part of + + + align:start position:0% +it right so that that so that's part of +the answer to your question that that + + align:start position:0% +the answer to your question that that + + + align:start position:0% +the answer to your question that that +the the the notion of an information of + + align:start position:0% +the the the notion of an information of + + + align:start position:0% +the the the notion of an information of +a of a relatively clear informational + + align:start position:0% +a of a relatively clear informational + + + align:start position:0% +a of a relatively clear informational +content that is communicated by the + + align:start position:0% +content that is communicated by the + + + align:start position:0% +content that is communicated by the +message is is is is oversimplified that + + align:start position:0% +message is is is is oversimplified that + + + align:start position:0% +message is is is is oversimplified that +we need to understand that the that the + + align:start position:0% +we need to understand that the that the + + + align:start position:0% +we need to understand that the that the +information itself is a uh a a series of + + align:start position:0% +information itself is a uh a a series of + + + align:start position:0% +information itself is a uh a a series of +constructions that are that that that + + align:start position:0% +constructions that are that that that + + + align:start position:0% +constructions that are that that that +part that also involve this Pro this + + align:start position:0% +part that also involve this Pro this + + + align:start position:0% +part that also involve this Pro this +ritualizing process of sharing meanings + + align:start position:0% +ritualizing process of sharing meanings + + + align:start position:0% +ritualizing process of sharing meanings +and of making meanings is the + + align:start position:0% +and of making meanings is the + + + align:start position:0% +and of making meanings is the +transmission model well when you say + + align:start position:0% +transmission model well when you say + + + align:start position:0% +transmission model well when you say +transmitting information is information + + align:start position:0% +transmitting information is information + + + align:start position:0% +transmitting information is information +in this case synonymous with stimuli + + align:start position:0% +in this case synonymous with stimuli + + + align:start position:0% +in this case synonymous with stimuli +because I I think I don't know I guess + + align:start position:0% +because I I think I don't know I guess + + + align:start position:0% +because I I think I don't know I guess +not no I mean it's it's it's synonymous + + align:start position:0% +not no I mean it's it's it's synonymous + + + align:start position:0% +not no I mean it's it's it's synonymous +with w w with with with with maybe a + + align:start position:0% +with w w with with with with maybe a + + + align:start position:0% +with w w with with with with maybe a +simple word for it would be with the + + align:start position:0% +simple word for it would be with the + + + align:start position:0% +simple word for it would be with the +message right whatever what let's think + + align:start position:0% +message right whatever what let's think + + + align:start position:0% +message right whatever what let's think +of the the the the message isn't a + + align:start position:0% +of the the the the message isn't a + + + align:start position:0% +of the the the the message isn't a +simple word is it with the with the with + + align:start position:0% +simple word is it with the with the with + + + align:start position:0% +simple word is it with the with the with +the uh U with the iota of data with the + + align:start position:0% +the uh U with the iota of data with the + + + align:start position:0% +the uh U with the iota of data with the +data that comes through the system in + + align:start position:0% +data that comes through the system in + + + align:start position:0% +data that comes through the system in +other words even the word fact is + + align:start position:0% +other words even the word fact is + + + align:start position:0% +other words even the word fact is +problematic here but you know in other + + align:start position:0% +problematic here but you know in other + + + align:start position:0% +problematic here but you know in other +words uh imagine R commentator saying uh + + align:start position:0% +words uh imagine R commentator saying uh + + + align:start position:0% +words uh imagine R commentator saying uh +two planes apparently um piloted by + + align:start position:0% +two planes apparently um piloted by + + + align:start position:0% +two planes apparently um piloted by +terrorists full of full of passengers + + align:start position:0% +terrorists full of full of passengers + + + align:start position:0% +terrorists full of full of passengers +crashed into the World Trade Center + + align:start position:0% +crashed into the World Trade Center + + + align:start position:0% +crashed into the World Trade Center +today that that right that + + align:start position:0% +today that that right that + + + align:start position:0% +today that that right that +straightforward statement of quote fact + + align:start position:0% +straightforward statement of quote fact + + + align:start position:0% +straightforward statement of quote fact +um W uh might constitute sort of the the + + align:start position:0% +um W uh might constitute sort of the the + + + align:start position:0% +um W uh might constitute sort of the the +the the basic data and then what happens + + align:start position:0% +the the basic data and then what happens + + + align:start position:0% +the the basic data and then what happens +is we that data is immediately + + align:start position:0% +is we that data is immediately + + + align:start position:0% +is we that data is immediately +surrounded by an immense amount of of of + + align:start position:0% +surrounded by an immense amount of of of + + + align:start position:0% +surrounded by an immense amount of of of +commentary and communicate and and + + align:start position:0% +commentary and communicate and and + + + align:start position:0% +commentary and communicate and and +interpretation the the data is + + align:start position:0% +interpretation the the data is + + + align:start position:0% +interpretation the the data is +constructed and made made usable by a + + align:start position:0% +constructed and made made usable by a + + + align:start position:0% +constructed and made made usable by a +process of of of understanding that and + + align:start position:0% +process of of of understanding that and + + + align:start position:0% +process of of of understanding that and +and and and interpretation that + + align:start position:0% +and and and interpretation that + + + align:start position:0% +and and and interpretation that +surrounds it all right this is my last + + align:start position:0% +surrounds it all right this is my last + + + align:start position:0% +surrounds it all right this is my last +comment it's just that uh I was thinking + + align:start position:0% +comment it's just that uh I was thinking + + + align:start position:0% +comment it's just that uh I was thinking +all right so forget the news because + + align:start position:0% +all right so forget the news because + + + align:start position:0% +all right so forget the news because +let's say for example the news is the + + align:start position:0% +let's say for example the news is the + + + align:start position:0% +let's say for example the news is the +transmission of information under all + + align:start position:0% +transmission of information under all + + + align:start position:0% +transmission of information under all +intensive purposes but what about + + align:start position:0% +intensive purposes but what about + + + align:start position:0% +intensive purposes but what about +sitcoms like you mention it + + align:start position:0% +sitcoms like you mention it + + + align:start position:0% +sitcoms like you mention it +um sitting around watching a + + align:start position:0% +um sitting around watching a + + + align:start position:0% +um sitting around watching a +sitcom uh and you know that millions of + + align:start position:0% +sitcom uh and you know that millions of + + + align:start position:0% +sitcom uh and you know that millions of +people around the country are also + + align:start position:0% +people around the country are also + + + align:start position:0% +people around the country are also +watching the sitcom you you're still + + align:start position:0% +watching the sitcom you you're still + + + align:start position:0% +watching the sitcom you you're still +receiving stimuli but not actually I + + align:start position:0% +receiving stimuli but not actually I + + + align:start position:0% +receiving stimuli but not actually I +have no clue what I was going to say + + align:start position:0% +have no clue what I was going to say + + + align:start position:0% +have no clue what I was going to say +with that well I mean I think see I + + align:start position:0% +with that well I mean I think see I + + + align:start position:0% +with that well I mean I think see I +think in a way in a way the the notion + + align:start position:0% +think in a way in a way the the notion + + + align:start position:0% +think in a way in a way the the notion +of the of communication systems as + + align:start position:0% +of the of communication systems as + + + align:start position:0% +of the of communication systems as +ritual as engaging in a remember we're + + align:start position:0% +ritual as engaging in a remember we're + + + align:start position:0% +ritual as engaging in a remember we're +not saying that that that either either + + align:start position:0% +not saying that that that either either + + + align:start position:0% +not saying that that that either either +function cancels the other right but the + + align:start position:0% +function cancels the other right but the + + + align:start position:0% +function cancels the other right but the +notion of communication systems as + + align:start position:0% +notion of communication systems as + + + align:start position:0% +notion of communication systems as +performing a ritual function is + + align:start position:0% +performing a ritual function is + + + align:start position:0% +performing a ritual function is +immensely helpful because it actually + + align:start position:0% +immensely helpful because it actually + + + align:start position:0% +immensely helpful because it actually +explains not only the fact that we keep + + align:start position:0% +explains not only the fact that we keep + + + align:start position:0% +explains not only the fact that we keep +not only the fact that we surround the + + align:start position:0% +not only the fact that we surround the + + + align:start position:0% +not only the fact that we surround the +so-called facts with all kinds of + + align:start position:0% +so-called facts with all kinds of + + + align:start position:0% +so-called facts with all kinds of +potentially competing interpretation but + + align:start position:0% +potentially competing interpretation but + + + align:start position:0% +potentially competing interpretation but +it also explains other aspects of our + + align:start position:0% +it also explains other aspects of our + + + align:start position:0% +it also explains other aspects of our +experience of media that don't have to + + align:start position:0% +experience of media that don't have to + + + align:start position:0% +experience of media that don't have to +do with the Transmissions of news + + align:start position:0% +do with the Transmissions of news + + + align:start position:0% +do with the Transmissions of news +reports right it's precisely that but it + + align:start position:0% +reports right it's precisely that but it + + + align:start position:0% +reports right it's precisely that but it +it isn't simply the the it isn't in this + + align:start position:0% +it isn't simply the the it isn't in this + + + align:start position:0% +it isn't simply the the it isn't in this +in the case of the situation comedy it + + align:start position:0% +in the case of the situation comedy it + + + align:start position:0% +in the case of the situation comedy it +isn't just the situation the single + + align:start position:0% +isn't just the situation the single + + + align:start position:0% +isn't just the situation the single +situation comedy we're talking about + + align:start position:0% +situation comedy we're talking about + + + align:start position:0% +situation comedy we're talking about +necessarily what it is it's the process + + align:start position:0% +necessarily what it is it's the process + + + align:start position:0% +necessarily what it is it's the process +of sitting down and over over + + align:start position:0% +of sitting down and over over + + + align:start position:0% +of sitting down and over over +Generations right over many nights + + align:start position:0% +Generations right over many nights + + + align:start position:0% +Generations right over many nights +watching these stories of families in + + align:start position:0% +watching these stories of families in + + + align:start position:0% +watching these stories of families in +domestic environments interacting so + + align:start position:0% +domestic environments interacting so + + + align:start position:0% +domestic environments interacting so +that what what's the effect of that in + + align:start position:0% +that what what's the effect of that in + + + align:start position:0% +that what what's the effect of that in +other words if we think about it in + + align:start position:0% +other words if we think about it in + + + align:start position:0% +other words if we think about it in +other words the at at the very center of + + align:start position:0% +other words the at at the very center of + + + align:start position:0% +other words the at at the very center of +the mythology of American Television + + align:start position:0% +the mythology of American Television + + + align:start position:0% +the mythology of American Television +over the uh period uh that we're going + + align:start position:0% +over the uh period uh that we're going + + + align:start position:0% +over the uh period uh that we're going +to be interested in uh is is some notion + + align:start position:0% +to be interested in uh is is some notion + + + align:start position:0% +to be interested in uh is is some notion +of the family right families are are + + align:start position:0% +of the family right families are are + + + align:start position:0% +of the family right families are are +among are are among the decisive + + align:start position:0% +among are are among the decisive + + + align:start position:0% +among are are among the decisive +recurring uh institutions that that that + + align:start position:0% +recurring uh institutions that that that + + + align:start position:0% +recurring uh institutions that that that +a variety of of of Television genres + + align:start position:0% +a variety of of of Television genres + + + align:start position:0% +a variety of of of Television genres +deal with so in a certain sense what + + align:start position:0% +deal with so in a certain sense what + + + align:start position:0% +deal with so in a certain sense what +what what what's going on is ideas of + + align:start position:0% +what what what's going on is ideas of + + + align:start position:0% +what what what's going on is ideas of +the family are being rehearsed are being + + align:start position:0% +the family are being rehearsed are being + + + align:start position:0% +the family are being rehearsed are being +represented are being are are are are + + align:start position:0% +represented are being are are are are + + + align:start position:0% +represented are being are are are are +being and and and what's happening is + + align:start position:0% +being and and and what's happening is + + + align:start position:0% +being and and and what's happening is +that stories about family life stories + + align:start position:0% +that stories about family life stories + + + align:start position:0% +that stories about family life stories +about the relation between husbands and + + align:start position:0% +about the relation between husbands and + + + align:start position:0% +about the relation between husbands and +wives between mothers and and children + + align:start position:0% +wives between mothers and and children + + + align:start position:0% +wives between mothers and and children +between between the workplace and the + + align:start position:0% +between between the workplace and the + + + align:start position:0% +between between the workplace and the +and and the domestic space of the family + + align:start position:0% +and and the domestic space of the family + + + align:start position:0% +and and the domestic space of the family +are being repeated and enacted again and + + align:start position:0% +are being repeated and enacted again and + + + align:start position:0% +are being repeated and enacted again and +again and again in the course of the + + align:start position:0% +again and again in the course of the + + + align:start position:0% +again and again in the course of the +meeting so what's one function one one + + align:start position:0% +meeting so what's one function one one + + + align:start position:0% +meeting so what's one function one one +and it's very clear what the ritual + + align:start position:0% +and it's very clear what the ritual + + + align:start position:0% +and it's very clear what the ritual +function is once you see it over time + + align:start position:0% +function is once you see it over time + + + align:start position:0% +function is once you see it over time +right we could dramatize it very richly + + align:start position:0% +right we could dramatize it very richly + + + align:start position:0% +right we could dramatize it very richly +if let's let's do an oversimplified + + align:start position:0% +if let's let's do an oversimplified + + + align:start position:0% +if let's let's do an oversimplified +version of it to clarify what we're + + align:start position:0% +version of it to clarify what we're + + + align:start position:0% +version of it to clarify what we're +talking about here this is why a ritual + + align:start position:0% +talking about here this is why a ritual + + + align:start position:0% +talking about here this is why a ritual +view of the medium is so helpful for non + + align:start position:0% +view of the medium is so helpful for non + + + align:start position:0% +view of the medium is so helpful for non +news non-documentary programming + + align:start position:0% +news non-documentary programming + + + align:start position:0% +news non-documentary programming +especially let's just stick very quickly + + align:start position:0% +especially let's just stick very quickly + + + align:start position:0% +especially let's just stick very quickly +to a kind of evolution of situation + + align:start position:0% +to a kind of evolution of situation + + + align:start position:0% +to a kind of evolution of situation +comedy and suppose we went from I Love + + align:start position:0% + + + + align:start position:0% + +Lucy to the Dick Van djk + + align:start position:0% + + + + align:start position:0% + +show + + align:start position:0% +show + + + align:start position:0% +show +to Mary Tyler Moore The Mary Tyler Moore + + align:start position:0% +to Mary Tyler Moore The Mary Tyler Moore + + + align:start position:0% +to Mary Tyler Moore The Mary Tyler Moore +Show to we're going to go right to uh + + align:start position:0% + + + + align:start position:0% + +Rosanne right we could we could go on + + align:start position:0% +Rosanne right we could we could go on + + + align:start position:0% +Rosanne right we could we could go on +but so or let's go let's take let's make + + align:start position:0% +but so or let's go let's take let's make + + + align:start position:0% +but so or let's go let's take let's make +one more trip step what what's the step + + align:start position:0% +one more trip step what what's the step + + + align:start position:0% +one more trip step what what's the step +one of you wants to write about this sex + + align:start position:0% +one of you wants to write about this sex + + + align:start position:0% +one of you wants to write about this sex +in the + + align:start position:0% + + + + align:start position:0% + +city now I'm oversimplifying here Sex in + + align:start position:0% +city now I'm oversimplifying here Sex in + + + align:start position:0% +city now I'm oversimplifying here Sex in +the City doesn't fit perfectly well + + align:start position:0% +the City doesn't fit perfectly well + + + align:start position:0% +the City doesn't fit perfectly well +because it's not actually a perfect + + align:start position:0% +because it's not actually a perfect + + + align:start position:0% +because it's not actually a perfect +situation comedy oh we might we could + + align:start position:0% +situation comedy oh we might we could + + + align:start position:0% +situation comedy oh we might we could +put friends in here if you want because + + align:start position:0% +put friends in here if you want because + + + align:start position:0% +put friends in here if you want because +something happens in the 80s and 90s + + align:start position:0% +something happens in the 80s and 90s + + + align:start position:0% +something happens in the 80s and 90s +families begin to disappear well what + + align:start position:0% +families begin to disappear well what + + + align:start position:0% +families begin to disappear well what +does this I mean many other things are + + align:start position:0% +does this I mean many other things are + + + align:start position:0% +does this I mean many other things are +going on and we'd have to surr this this + + align:start position:0% +going on and we'd have to surr this this + + + align:start position:0% +going on and we'd have to surr this this +progression oversimplifies because there + + align:start position:0% +progression oversimplifies because there + + + align:start position:0% +progression oversimplifies because there +are dozens and dozens of situation + + align:start position:0% +are dozens and dozens of situation + + + align:start position:0% +are dozens and dozens of situation +comedies in each year right uh but still + + align:start position:0% +comedies in each year right uh but still + + + align:start position:0% +comedies in each year right uh but still +let's say these are in certain ways + + align:start position:0% +let's say these are in certain ways + + + align:start position:0% +let's say these are in certain ways +representative what's going on here + + align:start position:0% +representative what's going on here + + + align:start position:0% +representative what's going on here +right uh Lucy constrained in the house + + align:start position:0% +right uh Lucy constrained in the house + + + align:start position:0% +right uh Lucy constrained in the house +all the time the basic plot of The Lucy + + align:start position:0% +all the time the basic plot of The Lucy + + + align:start position:0% +all the time the basic plot of The Lucy +Show is Lucy wants to get out of her + + align:start position:0% +Show is Lucy wants to get out of her + + + align:start position:0% +Show is Lucy wants to get out of her +domestic constraints and in the court + + align:start position:0% +domestic constraints and in the court + + + align:start position:0% +domestic constraints and in the court +and and and the basic plot is a + + align:start position:0% +and and and the basic plot is a + + + align:start position:0% +and and and the basic plot is a +humiliation plot in which Lucy tries to + + align:start position:0% +humiliation plot in which Lucy tries to + + + align:start position:0% +humiliation plot in which Lucy tries to +become uh to get into Ricky's show or + + align:start position:0% +become uh to get into Ricky's show or + + + align:start position:0% +become uh to get into Ricky's show or +tries to get onto a quiz show or tries + + align:start position:0% +tries to get onto a quiz show or tries + + + align:start position:0% +tries to get onto a quiz show or tries +to or tries to uh become an entrepreneur + + align:start position:0% +to or tries to uh become an entrepreneur + + + align:start position:0% +to or tries to uh become an entrepreneur +by producing vitamins right uh and in + + align:start position:0% +by producing vitamins right uh and in + + + align:start position:0% +by producing vitamins right uh and in +every case she suffers a horrific + + align:start position:0% +every case she suffers a horrific + + + align:start position:0% +every case she suffers a horrific +humiliation horrific comic humiliation + + align:start position:0% +humiliation horrific comic humiliation + + + align:start position:0% +humiliation horrific comic humiliation +at the end right uh so uh the notion + + align:start position:0% +at the end right uh so uh the notion + + + align:start position:0% +at the end right uh so uh the notion +here is that the norm is women belong in + + align:start position:0% +here is that the norm is women belong in + + + align:start position:0% +here is that the norm is women belong in +the home and that Lucy's comic lovable + + align:start position:0% +the home and that Lucy's comic lovable + + + align:start position:0% +the home and that Lucy's comic lovable +but comic desires to escape the home are + + align:start position:0% +but comic desires to escape the home are + + + align:start position:0% +but comic desires to escape the home are +just that lovable and comic and not to + + align:start position:0% +just that lovable and comic and not to + + + align:start position:0% +just that lovable and comic and not to +be taken seriously but we go we move to + + align:start position:0% +be taken seriously but we go we move to + + + align:start position:0% +be taken seriously but we go we move to +the Dick Van djk show uh uh we've moved + + align:start position:0% +the Dick Van djk show uh uh we've moved + + + align:start position:0% +the Dick Van djk show uh uh we've moved +from the city to the suburbs which is an + + align:start position:0% +from the city to the suburbs which is an + + + align:start position:0% +from the city to the suburbs which is an +interesting move in itself that tells us + + align:start position:0% +interesting move in itself that tells us + + + align:start position:0% +interesting move in itself that tells us +something about the family right but + + align:start position:0% +something about the family right but + + + align:start position:0% +something about the family right but +children the CH children play a slightly + + align:start position:0% +children the CH children play a slightly + + + align:start position:0% +children the CH children play a slightly +more important role and there are other + + align:start position:0% +more important role and there are other + + + align:start position:0% +more important role and there are other +shows we could mention where that's more + + align:start position:0% +shows we could mention where that's more + + + align:start position:0% +shows we could mention where that's more +important but the wife here is a woman + + align:start position:0% +important but the wife here is a woman + + + align:start position:0% +important but the wife here is a woman +who had a career before her her her uh + + align:start position:0% +who had a career before her her her uh + + + align:start position:0% +who had a career before her her her uh +her uh marriage began and there are + + align:start position:0% +her uh marriage began and there are + + + align:start position:0% +her uh marriage began and there are +various moments in the show where she + + align:start position:0% +various moments in the show where she + + + align:start position:0% +various moments in the show where she +returns to her career in certain ways + + align:start position:0% +returns to her career in certain ways + + + align:start position:0% +returns to her career in certain ways +that seem to threaten the F the the + + align:start position:0% +that seem to threaten the F the the + + + align:start position:0% +that seem to threaten the F the the +fabric by the time we get to the Mary + + align:start position:0% +fabric by the time we get to the Mary + + + align:start position:0% +fabric by the time we get to the Mary +Tyler Moore Show what's happened the + + align:start position:0% +Tyler Moore Show what's happened the + + + align:start position:0% +Tyler Moore Show what's happened the +same actress who is the mother here and + + align:start position:0% +same actress who is the mother here and + + + align:start position:0% +same actress who is the mother here and +that makes it further complicates the + + align:start position:0% +that makes it further complicates the + + + align:start position:0% +that makes it further complicates the +continuity right uh make and makes the + + align:start position:0% +continuity right uh make and makes the + + + align:start position:0% +continuity right uh make and makes the +argument even more explicit that that + + align:start position:0% +argument even more explicit that that + + + align:start position:0% +argument even more explicit that that +that we the same actress who who was the + + align:start position:0% +that we the same actress who who was the + + + align:start position:0% +that we the same actress who who was the +homebody Suburban mother frequently in + + align:start position:0% +homebody Suburban mother frequently in + + + align:start position:0% +homebody Suburban mother frequently in +the Dick Van Dyk show she's given an + + align:start position:0% +the Dick Van Dyk show she's given an + + + align:start position:0% +the Dick Van Dyk show she's given an +opportunity to become the dancer that + + align:start position:0% +opportunity to become the dancer that + + + align:start position:0% +opportunity to become the dancer that +she was before she was married and she + + align:start position:0% +she was before she was married and she + + + align:start position:0% +she was before she was married and she +turns it down because because she loves + + align:start position:0% +turns it down because because she loves + + + align:start position:0% +turns it down because because she loves +the Domesticity of of uh uh being a + + align:start position:0% +the Domesticity of of uh uh being a + + + align:start position:0% +the Domesticity of of uh uh being a +being a Suburban housewife right there's + + align:start position:0% +being a Suburban housewife right there's + + + align:start position:0% +being a Suburban housewife right there's +an even more dramatic example of this + + align:start position:0% +an even more dramatic example of this + + + align:start position:0% +an even more dramatic example of this +that we'll talk about briefly when we + + align:start position:0% +that we'll talk about briefly when we + + + align:start position:0% +that we'll talk about briefly when we +start looking at actual programs uh it's + + align:start position:0% +start looking at actual programs uh it's + + + align:start position:0% +start looking at actual programs uh it's +a magical show how many of you know the + + align:start position:0% +a magical show how many of you know the + + + align:start position:0% +a magical show how many of you know the +show I Dream of + + align:start position:0% +show I Dream of + + + align:start position:0% +show I Dream of +Genie almost everyone and that's a + + align:start position:0% +Genie almost everyone and that's a + + + align:start position:0% +Genie almost everyone and that's a +measure of how it's still a how how how + + align:start position:0% +measure of how it's still a how how how + + + align:start position:0% +measure of how it's still a how how how +how the TV is a universal a universal + + align:start position:0% +how the TV is a universal a universal + + + align:start position:0% +how the TV is a universal a universal +show uh can you think of another magical + + align:start position:0% +show uh can you think of another magical + + + align:start position:0% +show uh can you think of another magical +show like that Bewitched Bewitched may + + align:start position:0% +show like that Bewitched Bewitched may + + + align:start position:0% +show like that Bewitched Bewitched may +be even a better example but in both + + align:start position:0% +be even a better example but in both + + + align:start position:0% +be even a better example but in both +those cases what's interesting about + + align:start position:0% +those cases what's interesting about + + + align:start position:0% +those cases what's interesting about +them the women have magical powers in + + align:start position:0% +them the women have magical powers in + + + align:start position:0% +them the women have magical powers in +those show they're they're superhuman + + align:start position:0% +those show they're they're superhuman + + + align:start position:0% +those show they're they're superhuman +they're not they're not human beings in + + align:start position:0% +they're not they're not human beings in + + + align:start position:0% +they're not they're not human beings in +one case it's a witch and Genie is a + + align:start position:0% +one case it's a witch and Genie is a + + + align:start position:0% +one case it's a witch and Genie is a +genie right uh they have they have total + + align:start position:0% +genie right uh they have they have total + + + align:start position:0% +genie right uh they have they have total +power how do they choose to use their + + align:start position:0% +power how do they choose to use their + + + align:start position:0% +power how do they choose to use their +power totally subordinating themselves + + align:start position:0% +power totally subordinating themselves + + + align:start position:0% +power totally subordinating themselves +right they she can um the the mother in + + align:start position:0% +right they she can um the the mother in + + + align:start position:0% +right they she can um the the mother in +Bewitched uh could twitch her nose and + + align:start position:0% +Bewitched uh could twitch her nose and + + + align:start position:0% +Bewitched uh could twitch her nose and +clean the house but she prefers to use a + + align:start position:0% +clean the house but she prefers to use a + + + align:start position:0% +clean the house but she prefers to use a +broom and a dust mop because because her + + align:start position:0% +broom and a dust mop because because her + + + align:start position:0% +broom and a dust mop because because her +hubby prefers it right she could she + + align:start position:0% +hubby prefers it right she could she + + + align:start position:0% +hubby prefers it right she could she +could by the twitch of her nose travel + + align:start position:0% +could by the twitch of her nose travel + + + align:start position:0% +could by the twitch of her nose travel +to Paris with her mother and have a + + align:start position:0% +to Paris with her mother and have a + + + align:start position:0% +to Paris with her mother and have a +delicious meal at the fanciest Parisian + + align:start position:0% +delicious meal at the fanciest Parisian + + + align:start position:0% +delicious meal at the fanciest Parisian +Restaurant but she chooses to make pot + + align:start position:0% +Restaurant but she chooses to make pot + + + align:start position:0% +Restaurant but she chooses to make pot +roast for her husband who comes home + + align:start position:0% +roast for her husband who comes home + + + align:start position:0% +roast for her husband who comes home +from a hard day at the office right + + align:start position:0% +from a hard day at the office right + + + align:start position:0% +from a hard day at the office right +there think of the think of the the Fant + + align:start position:0% +there think of the think of the the Fant + + + align:start position:0% +there think of the think of the the Fant +the fantast the fantasy that the + + align:start position:0% +the fantast the fantasy that the + + + align:start position:0% +the fantast the fantasy that the +patriarchal culture is Eng engaging in + + align:start position:0% +patriarchal culture is Eng engaging in + + + align:start position:0% +patriarchal culture is Eng engaging in +here but still you can think of it as + + align:start position:0% +here but still you can think of it as + + + align:start position:0% +here but still you can think of it as +this it's comic but it's still engaging + + align:start position:0% +this it's comic but it's still engaging + + + align:start position:0% +this it's comic but it's still engaging +in a kind of discourse about the about + + align:start position:0% +in a kind of discourse about the about + + + align:start position:0% +in a kind of discourse about the about +gender relations and about the power + + align:start position:0% +gender relations and about the power + + + align:start position:0% +gender relations and about the power +relations uh uh in families right by the + + align:start position:0% +relations uh uh in families right by the + + + align:start position:0% +relations uh uh in families right by the +time we get to the mar Mary Tyler Mo + + align:start position:0% +time we get to the mar Mary Tyler Mo + + + align:start position:0% +time we get to the mar Mary Tyler Mo +show what's happened the woman has been + + align:start position:0% +show what's happened the woman has been + + + align:start position:0% +show what's happened the woman has been +liberated right it's a single woman + + align:start position:0% +liberated right it's a single woman + + + align:start position:0% +liberated right it's a single woman +she's trying to make it on her own right + + align:start position:0% +she's trying to make it on her own right + + + align:start position:0% +she's trying to make it on her own right +but in an odd way and know because + + align:start position:0% +but in an odd way and know because + + + align:start position:0% +but in an odd way and know because +television is always conservative as + + align:start position:0% +television is always conservative as + + + align:start position:0% +television is always conservative as +well as because because this Pro this + + align:start position:0% +well as because because this Pro this + + + align:start position:0% +well as because because this Pro this +ritualized process is complicated and + + align:start position:0% +ritualized process is complicated and + + + align:start position:0% +ritualized process is complicated and +what uh and and uh new or emergent ideas + + align:start position:0% +what uh and and uh new or emergent ideas + + + align:start position:0% +what uh and and uh new or emergent ideas +are treated very gingerly and nervously + + align:start position:0% +are treated very gingerly and nervously + + + align:start position:0% +are treated very gingerly and nervously +in a conservative consensus medium which + + align:start position:0% +in a conservative consensus medium which + + + align:start position:0% +in a conservative consensus medium which +is what television was what hap what + + align:start position:0% +is what television was what hap what + + + align:start position:0% +is what television was what hap what +happens the + + align:start position:0% +happens the + + + align:start position:0% +happens the +there is a family there isn't it the + + align:start position:0% +there is a family there isn't it the + + + align:start position:0% +there is a family there isn't it the +workplace is reconstituted as a kind of + + align:start position:0% +workplace is reconstituted as a kind of + + + align:start position:0% +workplace is reconstituted as a kind of +family and the and in fact it resembles + + align:start position:0% +family and the and in fact it resembles + + + align:start position:0% +family and the and in fact it resembles +a lot of the families of situation + + align:start position:0% +a lot of the families of situation + + + align:start position:0% +a lot of the families of situation +comedies of the past right so that so + + align:start position:0% +comedies of the past right so that so + + + align:start position:0% +comedies of the past right so that so +that uh uh Ted Baxter is the sort of is + + align:start position:0% +that uh uh Ted Baxter is the sort of is + + + align:start position:0% +that uh uh Ted Baxter is the sort of is +is the sort of foolish silly + + align:start position:0% +is the sort of foolish silly + + + align:start position:0% +is the sort of foolish silly +embarrassing uh brother figure right and + + align:start position:0% +embarrassing uh brother figure right and + + + align:start position:0% +embarrassing uh brother figure right and +and and Lou Grant is the benign Father + + align:start position:0% +and and Lou Grant is the benign Father + + + align:start position:0% +and and Lou Grant is the benign Father +Figure right uh and and and the + + align:start position:0% +Figure right uh and and and the + + + align:start position:0% +Figure right uh and and and the +workplace replaces the family but there + + align:start position:0% +workplace replaces the family but there + + + align:start position:0% +workplace replaces the family but there +but but in ways that make sort of + + align:start position:0% +but but in ways that make sort of + + + align:start position:0% +but but in ways that make sort of +explicit that the values that we had + + align:start position:0% +explicit that the values that we had + + + align:start position:0% +explicit that the values that we had +associated with Family Life are somehow + + align:start position:0% +associated with Family Life are somehow + + + align:start position:0% +associated with Family Life are somehow +still alive in this new environment + + align:start position:0% +still alive in this new environment + + + align:start position:0% +still alive in this new environment +what's going on in a certain sense is + + align:start position:0% +what's going on in a certain sense is + + + align:start position:0% +what's going on in a certain sense is +exactly this ritualizing process in + + align:start position:0% +exactly this ritualizing process in + + + align:start position:0% +exactly this ritualizing process in +which the society is responding and so + + align:start position:0% +which the society is responding and so + + + align:start position:0% +which the society is responding and so +if we think of situ the discourses of + + align:start position:0% +if we think of situ the discourses of + + + align:start position:0% +if we think of situ the discourses of +situation comedy as a whole we're not + + align:start position:0% +situation comedy as a whole we're not + + + align:start position:0% +situation comedy as a whole we're not +we're not talking in an artistic or + + align:start position:0% +we're not talking in an artistic or + + + align:start position:0% +we're not talking in an artistic or +aesthetic mode now right we're talking + + align:start position:0% +aesthetic mode now right we're talking + + + align:start position:0% +aesthetic mode now right we're talking +in an anthropological or cultural mode + + align:start position:0% +in an anthropological or cultural mode + + + align:start position:0% +in an anthropological or cultural mode +we're saying what cultural work do + + align:start position:0% +we're saying what cultural work do + + + align:start position:0% +we're saying what cultural work do +television programs play they play a + + align:start position:0% +television programs play they play a + + + align:start position:0% +television programs play they play a +ritualized role one of the things they + + align:start position:0% +ritualized role one of the things they + + + align:start position:0% +ritualized role one of the things they +do is they rehearse ideas about human + + align:start position:0% +do is they rehearse ideas about human + + + align:start position:0% +do is they rehearse ideas about human +nature about the role of women about the + + align:start position:0% +nature about the role of women about the + + + align:start position:0% +nature about the role of women about the +role of families and and they and and + + align:start position:0% +role of families and and they and and + + + align:start position:0% +role of families and and they and and +and and again remember the the point the + + align:start position:0% +and and again remember the the point the + + + align:start position:0% +and and again remember the the point the +idea is that that that uh the the main + + align:start position:0% +idea is that that that uh the the main + + + align:start position:0% +idea is that that that uh the the main +the maintenance and reparation of the + + align:start position:0% +the maintenance and reparation of the + + + align:start position:0% +the maintenance and reparation of the +social fabric is not a job that's ever + + align:start position:0% +social fabric is not a job that's ever + + + align:start position:0% +social fabric is not a job that's ever +finished this is why the series is such + + align:start position:0% +finished this is why the series is such + + + align:start position:0% +finished this is why the series is such +a genius format for this process because + + align:start position:0% +a genius format for this process because + + + align:start position:0% +a genius format for this process because +series are theoretically endless ongoing + + align:start position:0% +series are theoretically endless ongoing + + + align:start position:0% +series are theoretically endless ongoing +right uh so the idea is that the process + + align:start position:0% +right uh so the idea is that the process + + + align:start position:0% +right uh so the idea is that the process +of defining a culture the process + + align:start position:0% +of defining a culture the process + + + align:start position:0% +of defining a culture the process +whereby a culture defines its nature and + + align:start position:0% +whereby a culture defines its nature and + + + align:start position:0% +whereby a culture defines its nature and +organizes its systems of values is + + align:start position:0% +organizes its systems of values is + + + align:start position:0% +organizes its systems of values is +always unfinished it's always in flux + + align:start position:0% +always unfinished it's always in flux + + + align:start position:0% +always unfinished it's always in flux +culture's always right this is culture + + align:start position:0% +culture's always right this is culture + + + align:start position:0% +culture's always right this is culture +is always a conversation I mean I I hope + + align:start position:0% +is always a conversation I mean I I hope + + + align:start position:0% +is always a conversation I mean I I hope +you see how these ideas are also + + align:start position:0% +you see how these ideas are also + + + align:start position:0% +you see how these ideas are also +embedded in my essay television as an + + align:start position:0% +embedded in my essay television as an + + + align:start position:0% +embedded in my essay television as an +aesthetic medium and and and and and and + + align:start position:0% +aesthetic medium and and and and and and + + + align:start position:0% +aesthetic medium and and and and and and +this flux this uncertainty this this + + align:start position:0% +this flux this uncertainty this this + + + align:start position:0% +this flux this uncertainty this this +this Con this continuous process is is + + align:start position:0% +this Con this continuous process is is + + + align:start position:0% +this Con this continuous process is is +recaptured in a certain way or is or or + + align:start position:0% +recaptured in a certain way or is or or + + + align:start position:0% +recaptured in a certain way or is or or +is enacted in part for us in various + + align:start position:0% +is enacted in part for us in various + + + align:start position:0% +is enacted in part for us in various +media of communication not only in + + align:start position:0% +media of communication not only in + + + align:start position:0% +media of communication not only in +television but in various media of + + align:start position:0% +television but in various media of + + + align:start position:0% +television but in various media of +communication every time every time we + + align:start position:0% +communication every time every time we + + + align:start position:0% +communication every time every time we +go to the movie every time we turn on + + align:start position:0% +go to the movie every time we turn on + + + align:start position:0% +go to the movie every time we turn on +the radio every time we go to the + + align:start position:0% +the radio every time we go to the + + + align:start position:0% +the radio every time we go to the +theater every time we listen to a to a + + align:start position:0% +theater every time we listen to a to a + + + align:start position:0% +theater every time we listen to a to a +song every time we engage in any kind of + + align:start position:0% +song every time we engage in any kind of + + + align:start position:0% +song every time we engage in any kind of +institutionalized Behavior some aspect + + align:start position:0% +institutionalized Behavior some aspect + + + align:start position:0% +institutionalized Behavior some aspect +of our social life is being rehearsed or + + align:start position:0% +of our social life is being rehearsed or + + + align:start position:0% +of our social life is being rehearsed or +reinforced or challenged right but but + + align:start position:0% +reinforced or challenged right but but + + + align:start position:0% +reinforced or challenged right but but +there's but there are certain media in + + align:start position:0% +there's but there are certain media in + + + align:start position:0% +there's but there are certain media in +in in culture that that that that uh are + + align:start position:0% +in in culture that that that that uh are + + + align:start position:0% +in in culture that that that that uh are +are more important than others in trying + + align:start position:0% +are more important than others in trying + + + align:start position:0% +are more important than others in trying +to in trying to identify rehearse and + + align:start position:0% +to in trying to identify rehearse and + + + align:start position:0% +to in trying to identify rehearse and +Define what we might call the central or + + align:start position:0% +Define what we might call the central or + + + align:start position:0% +Define what we might call the central or +the defining or the consensus values of + + align:start position:0% +the defining or the consensus values of + + + align:start position:0% +the defining or the consensus values of +the society and my idea is uh that in + + align:start position:0% +the society and my idea is uh that in + + + align:start position:0% +the society and my idea is uh that in +most societies only one such institution + + align:start position:0% +most societies only one such institution + + + align:start position:0% +most societies only one such institution +is usually so designated I don't mean + + align:start position:0% +is usually so designated I don't mean + + + align:start position:0% +is usually so designated I don't mean +that there somebody says you will be the + + align:start position:0% +that there somebody says you will be the + + + align:start position:0% +that there somebody says you will be the +consensus medium of a society but I do + + align:start position:0% +consensus medium of a society but I do + + + align:start position:0% +consensus medium of a society but I do +mean that by a kind of very complex + + align:start position:0% +mean that by a kind of very complex + + + align:start position:0% +mean that by a kind of very complex +cultural sociological anthropological + + align:start position:0% +cultural sociological anthropological + + + align:start position:0% +cultural sociological anthropological +political process uh a particular medium + + align:start position:0% +political process uh a particular medium + + + align:start position:0% +political process uh a particular medium +is likely to emerge as the one that is + + align:start position:0% +is likely to emerge as the one that is + + + align:start position:0% +is likely to emerge as the one that is +most widely shared by the most people in + + align:start position:0% +most widely shared by the most people in + + + align:start position:0% +most widely shared by the most people in +the society that Medium it's not a + + align:start position:0% +the society that Medium it's not a + + + align:start position:0% +the society that Medium it's not a +better medium it's just different right + + align:start position:0% +better medium it's just different right + + + align:start position:0% +better medium it's just different right +theater in our society today is a + + align:start position:0% +theater in our society today is a + + + align:start position:0% +theater in our society today is a +subcultural experience it doesn't belong + + align:start position:0% +subcultural experience it doesn't belong + + + align:start position:0% +subcultural experience it doesn't belong +to the whole population right the same + + align:start position:0% +to the whole population right the same + + + align:start position:0% +to the whole population right the same +with wrestling the same with Opera right + + align:start position:0% +with wrestling the same with Opera right + + + align:start position:0% +with wrestling the same with Opera right +particular groups of people like Opera + + align:start position:0% +particular groups of people like Opera + + + align:start position:0% +particular groups of people like Opera +and go to Opera particular groups of + + align:start position:0% +and go to Opera particular groups of + + + align:start position:0% +and go to Opera particular groups of +people like country and western music + + align:start position:0% +people like country and western music + + + align:start position:0% +people like country and western music +those forms of of communication and exp + + align:start position:0% +those forms of of communication and exp + + + align:start position:0% +those forms of of communication and exp +and are also ritualized in certain ways + + align:start position:0% +and are also ritualized in certain ways + + + align:start position:0% +and are also ritualized in certain ways +uh those th those forms of entertainment + + align:start position:0% +uh those th those forms of entertainment + + + align:start position:0% +uh those th those forms of entertainment +and and uh uh um representation are are + + align:start position:0% +and and uh uh um representation are are + + + align:start position:0% +and and uh uh um representation are are +are not less valuable than the consensus + + align:start position:0% +are not less valuable than the consensus + + + align:start position:0% +are not less valuable than the consensus +system I want us to study today but + + align:start position:0% +system I want us to study today but + + + align:start position:0% +system I want us to study today but +they're different and one of the + + align:start position:0% +they're different and one of the + + + align:start position:0% +they're different and one of the +fundamental ways they're different is + + align:start position:0% +fundamental ways they're different is + + + align:start position:0% +fundamental ways they're different is +that the consensus medium has certain + + align:start position:0% +that the consensus medium has certain + + + align:start position:0% +that the consensus medium has certain +features that that that are a function + + align:start position:0% +features that that that are a function + + + align:start position:0% +features that that that are a function +of the fact that that Medium is + + align:start position:0% +of the fact that that Medium is + + + align:start position:0% +of the fact that that Medium is +understood by the whole society by a by + + align:start position:0% +understood by the whole society by a by + + + align:start position:0% +understood by the whole society by a by +a kind of process of of of Licensing and + + align:start position:0% +a kind of process of of of Licensing and + + + align:start position:0% +a kind of process of of of Licensing and +Broad agreement is understood by the + + align:start position:0% +Broad agreement is understood by the + + + align:start position:0% +Broad agreement is understood by the +whole society to address the whole + + align:start position:0% +whole society to address the whole + + + align:start position:0% +whole society to address the whole +society not it never really addresses + + align:start position:0% +society not it never really addresses + + + align:start position:0% +society not it never really addresses +the whole society there are always + + align:start position:0% +the whole society there are always + + + align:start position:0% +the whole society there are always +groups that are excluded and not + + align:start position:0% +groups that are excluded and not + + + align:start position:0% +groups that are excluded and not +acknowledged by the consensus media it's + + align:start position:0% +acknowledged by the consensus media it's + + + align:start position:0% +acknowledged by the consensus media it's +the consensus is not a a uh an authentic + + align:start position:0% +the consensus is not a a uh an authentic + + + align:start position:0% +the consensus is not a a uh an authentic +consensus in which which truly includes + + align:start position:0% +consensus in which which truly includes + + + align:start position:0% +consensus in which which truly includes +everyone right that's why I would always + + align:start position:0% +everyone right that's why I would always + + + align:start position:0% +everyone right that's why I would always +put consensus in quotation marks uh it's + + align:start position:0% +put consensus in quotation marks uh it's + + + align:start position:0% +put consensus in quotation marks uh it's +it's a it's it's a constructed consensus + + align:start position:0% +it's a it's it's a constructed consensus + + + align:start position:0% +it's a it's it's a constructed consensus +it's a consensus it's an imagined + + align:start position:0% +it's a consensus it's an imagined + + + align:start position:0% +it's a consensus it's an imagined +consensus right and in ear in in + + align:start position:0% +consensus right and in ear in in + + + align:start position:0% +consensus right and in ear in in +medieval Society the consensus medium + + align:start position:0% +medieval Society the consensus medium + + + align:start position:0% +medieval Society the consensus medium +was the Bible and the experience of + + align:start position:0% +was the Bible and the experience of + + + align:start position:0% +was the Bible and the experience of +going to attending church services where + + align:start position:0% +going to attending church services where + + + align:start position:0% +going to attending church services where +the meanings of the where the meanings + + align:start position:0% +the meanings of the where the meanings + + + align:start position:0% +the meanings of the where the meanings +in the Bible were promulgated and spread + + align:start position:0% +in the Bible were promulgated and spread + + + align:start position:0% +in the Bible were promulgated and spread +through the society right uh at a + + align:start position:0% +through the society right uh at a + + + align:start position:0% +through the society right uh at a +certain point I think the theater became + + align:start position:0% +certain point I think the theater became + + + align:start position:0% +certain point I think the theater became +the consensus medium at least of British + + align:start position:0% +the consensus medium at least of British + + + align:start position:0% +the consensus medium at least of British +Society the public theaters in + + align:start position:0% +Society the public theaters in + + + align:start position:0% +Society the public theaters in +Shakespeare's day were attended by the + + align:start position:0% +Shakespeare's day were attended by the + + + align:start position:0% +Shakespeare's day were attended by the +widest uh um uh swath of the population + + align:start position:0% +widest uh um uh swath of the population + + + align:start position:0% +widest uh um uh swath of the population +they they they they didn't they appealed + + align:start position:0% +they they they they didn't they appealed + + + align:start position:0% +they they they they didn't they appealed +much to let much less of a subculture + + align:start position:0% +much to let much less of a subculture + + + align:start position:0% +much to let much less of a subculture +than than other forms of entertainment + + align:start position:0% +than than other forms of entertainment + + + align:start position:0% +than than other forms of entertainment +and communication in the society uh in + + align:start position:0% +and communication in the society uh in + + + align:start position:0% +and communication in the society uh in +in a later phase I think the the the + + align:start position:0% +in a later phase I think the the the + + + align:start position:0% +in a later phase I think the the the +novel the printing press generated a + + align:start position:0% +novel the printing press generated a + + + align:start position:0% +novel the printing press generated a +particular form of narrative the novel + + align:start position:0% +particular form of narrative the novel + + + align:start position:0% +particular form of narrative the novel +which reached much more broadly much + + align:start position:0% +which reached much more broadly much + + + align:start position:0% +which reached much more broadly much +more widely across social classes across + + align:start position:0% +more widely across social classes across + + + align:start position:0% +more widely across social classes across +gender barriers uh than any prior system + + align:start position:0% +gender barriers uh than any prior system + + + align:start position:0% +gender barriers uh than any prior system +of narrative had done including the + + align:start position:0% +of narrative had done including the + + + align:start position:0% +of narrative had done including the +theater and the novel became in the 19th + + align:start position:0% +theater and the novel became in the 19th + + + align:start position:0% +theater and the novel became in the 19th +century and in part of the 18th century + + align:start position:0% +century and in part of the 18th century + + + align:start position:0% +century and in part of the 18th century +in certain European societies and in the + + align:start position:0% +in certain European societies and in the + + + align:start position:0% +in certain European societies and in the +United States the consensus medium the + + align:start position:0% +United States the consensus medium the + + + align:start position:0% +United States the consensus medium the +medium that and and and in in in the + + align:start position:0% +medium that and and and in in in the + + + align:start position:0% +medium that and and and in in in the +20th century I'm suggesting to you in + + align:start position:0% +20th century I'm suggesting to you in + + + align:start position:0% +20th century I'm suggesting to you in +the United States the movies and then + + align:start position:0% +the United States the movies and then + + + align:start position:0% +the United States the movies and then +television were the consensus medium + + align:start position:0% +television were the consensus medium + + + align:start position:0% +television were the consensus medium +I'll talk a bit more about this in a + + align:start position:0% +I'll talk a bit more about this in a + + + align:start position:0% +I'll talk a bit more about this in a +second + + align:start position:0% +second + + + align:start position:0% +second +so I I've jumped ahead but it's okay but + + align:start position:0% +so I I've jumped ahead but it's okay but + + + align:start position:0% +so I I've jumped ahead but it's okay but +so this notion one of the things I've + + align:start position:0% +so this notion one of the things I've + + + align:start position:0% +so this notion one of the things I've +been suggesting to you then is that + + align:start position:0% +been suggesting to you then is that + + + align:start position:0% +been suggesting to you then is that +culture itself is a process right + + align:start position:0% +culture itself is a process right + + + align:start position:0% +culture itself is a process right +culture itself is is never finished + + align:start position:0% +culture itself is is never finished + + + align:start position:0% +culture itself is is never finished +right + + align:start position:0% +right + + + align:start position:0% +right +uh this is an idea that comes especially + + align:start position:0% +uh this is an idea that comes especially + + + align:start position:0% +uh this is an idea that comes especially +out of the the the writings of Raymond + + align:start position:0% +out of the the the writings of Raymond + + + align:start position:0% +out of the the the writings of Raymond +Williams uh and uh the the British uh + + align:start position:0% +Williams uh and uh the the British uh + + + align:start position:0% +Williams uh and uh the the British uh +cultural historian and and and and + + align:start position:0% +cultural historian and and and and + + + align:start position:0% +cultural historian and and and and +sociolog literary scholar and + + align:start position:0% +sociolog literary scholar and + + + align:start position:0% +sociolog literary scholar and +sociologist and Williams suggest in + + align:start position:0% +sociologist and Williams suggest in + + + align:start position:0% +sociologist and Williams suggest in +several of in several places in his + + align:start position:0% +several of in several places in his + + + align:start position:0% +several of in several places in his +writings that one way to understand + + align:start position:0% +writings that one way to understand + + + align:start position:0% +writings that one way to understand +culture is to think of it literally as a + + align:start position:0% +culture is to think of it literally as a + + + align:start position:0% +culture is to think of it literally as a +kind of ongoing conversation never It's + + align:start position:0% +kind of ongoing conversation never It's + + + align:start position:0% +kind of ongoing conversation never It's +a Wonderful insight to recognize that + + align:start position:0% +a Wonderful insight to recognize that + + + align:start position:0% +a Wonderful insight to recognize that +culture itself is not fixed it's not + + align:start position:0% +culture itself is not fixed it's not + + + align:start position:0% +culture itself is not fixed it's not +finished it's continually in process and + + align:start position:0% +finished it's continually in process and + + + align:start position:0% +finished it's continually in process and +it's in and he he identifies what might + + align:start position:0% +it's in and he he identifies what might + + + align:start position:0% +it's in and he he identifies what might +be called three basic strands in the + + align:start position:0% +be called three basic strands in the + + + align:start position:0% +be called three basic strands in the +conversation of + + align:start position:0% +conversation of + + + align:start position:0% +conversation of +culture one strand is what might be + + align:start position:0% +culture one strand is what might be + + + align:start position:0% +culture one strand is what might be +called the residual Strand and that's + + align:start position:0% +called the residual Strand and that's + + + align:start position:0% +called the residual Strand and that's +the strand of of the set of values and + + align:start position:0% +the strand of of the set of values and + + + align:start position:0% +the strand of of the set of values and +beliefs that belong to the older to to + + align:start position:0% +beliefs that belong to the older to to + + + align:start position:0% +beliefs that belong to the older to to +an older time to an Era to the eras that + + align:start position:0% +an older time to an Era to the eras that + + + align:start position:0% +an older time to an Era to the eras that +are ending right we might think of + + align:start position:0% +are ending right we might think of + + + align:start position:0% +are ending right we might think of +certain kinds of U certain kinds of uh + + align:start position:0% +certain kinds of U certain kinds of uh + + + align:start position:0% +certain kinds of U certain kinds of uh +uh in our own Society c c certain + + align:start position:0% +uh in our own Society c c certain + + + align:start position:0% +uh in our own Society c c certain +Notions about about Rural America and + + align:start position:0% +Notions about about Rural America and + + + align:start position:0% +Notions about about Rural America and +about the values of small town America + + align:start position:0% +about the values of small town America + + + align:start position:0% +about the values of small town America +as having uh or or or or certain forms + + align:start position:0% +as having uh or or or or certain forms + + + align:start position:0% +as having uh or or or or certain forms +of religious fundamentalism in the + + align:start position:0% +of religious fundamentalism in the + + + align:start position:0% +of religious fundamentalism in the +United States as having as belonging to + + align:start position:0% +United States as having as belonging to + + + align:start position:0% +United States as having as belonging to +this residual discourse then there's the + + align:start position:0% +this residual discourse then there's the + + + align:start position:0% +this residual discourse then there's the +dominant discourse the discourse of the + + align:start position:0% +dominant discourse the discourse of the + + + align:start position:0% +dominant discourse the discourse of the +majority at the very center of what the + + align:start position:0% +majority at the very center of what the + + + align:start position:0% +majority at the very center of what the +culture thinks of itself and then on the + + align:start position:0% +culture thinks of itself and then on the + + + align:start position:0% +culture thinks of itself and then on the +other side there's what might be called + + align:start position:0% +other side there's what might be called + + + align:start position:0% +other side there's what might be called +emergent discourses discourses of ideas + + align:start position:0% +emergent discourses discourses of ideas + + + align:start position:0% +emergent discourses discourses of ideas +and perspectives and value systems value + + align:start position:0% +and perspectives and value systems value + + + align:start position:0% +and perspectives and value systems value +structures that are not yet fully + + align:start position:0% +structures that are not yet fully + + + align:start position:0% +structures that are not yet fully +established but are but are emerging and + + align:start position:0% +established but are but are emerging and + + + align:start position:0% +established but are but are emerging and +are likely to become important we might + + align:start position:0% +are likely to become important we might + + + align:start position:0% +are likely to become important we might +think for example of the ecology + + align:start position:0% +think for example of the ecology + + + align:start position:0% +think for example of the ecology +discourse today the the the the uh the + + align:start position:0% +discourse today the the the the uh the + + + align:start position:0% +discourse today the the the the uh the +or or the animal rights discourse today + + align:start position:0% +or or the animal rights discourse today + + + align:start position:0% +or or the animal rights discourse today +as part of an emergent discourse not yet + + align:start position:0% +as part of an emergent discourse not yet + + + align:start position:0% +as part of an emergent discourse not yet +at the center of uh cultural values but + + align:start position:0% +at the center of uh cultural values but + + + align:start position:0% +at the center of uh cultural values but +I think likely to become so certainly + + align:start position:0% +I think likely to become so certainly + + + align:start position:0% +I think likely to become so certainly +the ecological argument is be we can in + + align:start position:0% +the ecological argument is be we can in + + + align:start position:0% +the ecological argument is be we can in +your own lifetime has moved more and + + align:start position:0% +your own lifetime has moved more and + + + align:start position:0% +your own lifetime has moved more and +more toward toward the center maybe it's + + align:start position:0% +more toward toward the center maybe it's + + + align:start position:0% +more toward toward the center maybe it's +not yet acted at utterly at the center + + align:start position:0% +not yet acted at utterly at the center + + + align:start position:0% +not yet acted at utterly at the center +but it's much closer to the center than + + align:start position:0% +but it's much closer to the center than + + + align:start position:0% +but it's much closer to the center than +it was uh 15 or 20 years ago and there's + + align:start position:0% +it was uh 15 or 20 years ago and there's + + + align:start position:0% +it was uh 15 or 20 years ago and there's +an example of so and so we can think of + + align:start position:0% +an example of so and so we can think of + + + align:start position:0% +an example of so and so we can think of +culture as as as as a process in which + + align:start position:0% +culture as as as as a process in which + + + align:start position:0% +culture as as as as a process in which +these three kinds of voices of strains + + align:start position:0% +these three kinds of voices of strains + + + align:start position:0% +these three kinds of voices of strains +of value systems of beliefs of attitudes + + align:start position:0% +of value systems of beliefs of attitudes + + + align:start position:0% +of value systems of beliefs of attitudes +are in a kind of constant uh uh + + align:start position:0% +are in a kind of constant uh uh + + + align:start position:0% +are in a kind of constant uh uh +alternating flux or conversation and and + + align:start position:0% +alternating flux or conversation and and + + + align:start position:0% +alternating flux or conversation and and +and and it means that they shift in what + + align:start position:0% +and and it means that they shift in what + + + align:start position:0% +and and it means that they shift in what +what was once dominant can become + + align:start position:0% +what was once dominant can become + + + align:start position:0% +what was once dominant can become +residual and what was once what is now + + align:start position:0% +residual and what was once what is now + + + align:start position:0% +residual and what was once what is now +emergent can become part of the dominant + + align:start position:0% +emergent can become part of the dominant + + + align:start position:0% +emergent can become part of the dominant +value structure well the process whereby + + align:start position:0% +value structure well the process whereby + + + align:start position:0% +value structure well the process whereby +that + + align:start position:0% +that + + + align:start position:0% +that +happens is the process of communication + + align:start position:0% +happens is the process of communication + + + align:start position:0% +happens is the process of communication +and it specifically happens on the + + align:start position:0% +and it specifically happens on the + + + align:start position:0% +and it specifically happens on the +consensus medium that I've been talking + + align:start position:0% +consensus medium that I've been talking + + + align:start position:0% +consensus medium that I've been talking +about which will differ from different + + align:start position:0% +about which will differ from different + + + align:start position:0% +about which will differ from different +in different societies uh and I think + + align:start position:0% +in different societies uh and I think + + + align:start position:0% +in different societies uh and I think +one of the things one of the interesting + + align:start position:0% +one of the things one of the interesting + + + align:start position:0% +one of the things one of the interesting +things about our current moment is that + + align:start position:0% +things about our current moment is that + + + align:start position:0% +things about our current moment is that +television still performs in a in a in + + align:start position:0% +television still performs in a in a in + + + align:start position:0% +television still performs in a in a in +at least in a in a in a partial way the + + align:start position:0% +at least in a in a in a partial way the + + + align:start position:0% +at least in a in a in a partial way the +the the the the Great Central consensus + + align:start position:0% +the the the the Great Central consensus + + + align:start position:0% +the the the the Great Central consensus +role that had played through the late + + align:start position:0% +role that had played through the late + + + align:start position:0% +role that had played through the late +50s through the through the 80s sometime + + align:start position:0% +50s through the through the 80s sometime + + + align:start position:0% +50s through the through the 80s sometime +although it had already been aent by the + + align:start position:0% +although it had already been aent by the + + + align:start position:0% +although it had already been aent by the +end of the 70s you can see the system + + align:start position:0% +end of the 70s you can see the system + + + align:start position:0% +end of the 70s you can see the system +the consensus system beginning to fray + + align:start position:0% +the consensus system beginning to fray + + + align:start position:0% +the consensus system beginning to fray +and break down somewhat and we that's + + align:start position:0% +and break down somewhat and we that's + + + align:start position:0% +and break down somewhat and we that's +what we're going to study is that + + align:start position:0% +what we're going to study is that + + + align:start position:0% +what we're going to study is that +process whereby television becomes the + + align:start position:0% +process whereby television becomes the + + + align:start position:0% +process whereby television becomes the +consensus medium in the society uh + + align:start position:0% +consensus medium in the society uh + + + align:start position:0% +consensus medium in the society uh +articulates what are consensus values uh + + align:start position:0% +articulates what are consensus values uh + + + align:start position:0% +articulates what are consensus values uh +we can see the consensus values + + align:start position:0% +we can see the consensus values + + + align:start position:0% +we can see the consensus values +undergoing some radical threats and + + align:start position:0% +undergoing some radical threats and + + + align:start position:0% +undergoing some radical threats and +changes and then we can see the + + align:start position:0% +changes and then we can see the + + + align:start position:0% +changes and then we can see the +consensus function itself beginning to + + align:start position:0% +consensus function itself beginning to + + + align:start position:0% +consensus function itself beginning to +break down uh by the by by by some time + + align:start position:0% +break down uh by the by by by some time + + + align:start position:0% +break down uh by the by by by some time +at really begins to break down by the + + align:start position:0% +at really begins to break down by the + + + align:start position:0% +at really begins to break down by the +end of the 70s and it's a pro but it's a + + align:start position:0% +end of the 70s and it's a pro but it's a + + + align:start position:0% +end of the 70s and it's a pro but it's a +slow process it doesn't happen overnight + + align:start position:0% +slow process it doesn't happen overnight + + + align:start position:0% +slow process it doesn't happen overnight +and and uh these you know historical + + align:start position:0% +and and uh these you know historical + + + align:start position:0% +and and uh these you know historical +generalizations never have the neatness + + align:start position:0% +generalizations never have the neatness + + + align:start position:0% +generalizations never have the neatness +of of mathematical equations so it's not + + align:start position:0% +of of mathematical equations so it's not + + + align:start position:0% +of of mathematical equations so it's not +the case that one could say okay the + + align:start position:0% +the case that one could say okay the + + + align:start position:0% +the case that one could say okay the +consensus function of Television is + + align:start position:0% +consensus function of Television is + + + align:start position:0% +consensus function of Television is +completely gone now in 2001 but it's + + align:start position:0% +completely gone now in 2001 but it's + + + align:start position:0% +completely gone now in 2001 but it's +it's it's becoming it's it's becoming + + align:start position:0% +it's it's becoming it's it's becoming + + + align:start position:0% +it's it's becoming it's it's becoming +residual the reason that I gave out this + + align:start position:0% +residual the reason that I gave out this + + + align:start position:0% +residual the reason that I gave out this +uh uh piece from The New York Times is + + align:start position:0% +uh uh piece from The New York Times is + + + align:start position:0% +uh uh piece from The New York Times is +is that this moment we've been going + + align:start position:0% +is that this moment we've been going + + + align:start position:0% +is that this moment we've been going +through is a reminder of the extent to + + align:start position:0% +through is a reminder of the extent to + + + align:start position:0% +through is a reminder of the extent to +which television still performs + + align:start position:0% +which television still performs + + + align:start position:0% +which television still performs +especially at certain moments of + + align:start position:0% +especially at certain moments of + + + align:start position:0% +especially at certain moments of +cultural crisis the old consensus + + align:start position:0% +cultural crisis the old consensus + + + align:start position:0% +cultural crisis the old consensus +function that had performed in all of + + align:start position:0% +function that had performed in all of + + + align:start position:0% +function that had performed in all of +its in all ways through the 60s and 70s + + align:start position:0% +its in all ways through the 60s and 70s + + + align:start position:0% +its in all ways through the 60s and 70s +uh and uh the kind the kind of comfort + + align:start position:0% +uh and uh the kind the kind of comfort + + + align:start position:0% +uh and uh the kind the kind of comfort +and Solace that this country gut by + + align:start position:0% +and Solace that this country gut by + + + align:start position:0% +and Solace that this country gut by +watching Dan Rather BL fall into tears + + align:start position:0% +watching Dan Rather BL fall into tears + + + align:start position:0% +watching Dan Rather BL fall into tears +on the screen a Sentimental creature + + align:start position:0% +on the screen a Sentimental creature + + + align:start position:0% +on the screen a Sentimental creature +that he is he was on the he went on the + + align:start position:0% +that he is he was on the he went on the + + + align:start position:0% +that he is he was on the he went on the +David Letterman show and he broke down + + align:start position:0% +David Letterman show and he broke down + + + align:start position:0% +David Letterman show and he broke down +three times + + align:start position:0% +three times + + + align:start position:0% +three times +weeping I'm not I'm not much taken by + + align:start position:0% +weeping I'm not I'm not much taken by + + + align:start position:0% +weeping I'm not I'm not much taken by +that but but it's maybe part of the + + align:start position:0% +that but but it's maybe part of the + + + align:start position:0% +that but but it's maybe part of the +explanation for why Dan Rather has such + + align:start position:0% +explanation for why Dan Rather has such + + + align:start position:0% +explanation for why Dan Rather has such +an intimate connection to the audience + + align:start position:0% +an intimate connection to the audience + + + align:start position:0% +an intimate connection to the audience +that they they they sense How Deeply + + align:start position:0% +that they they they sense How Deeply + + + align:start position:0% +that they they they sense How Deeply +engaged he is by this by this uh story + + align:start position:0% +engaged he is by this by this uh story + + + align:start position:0% +engaged he is by this by this uh story +but in any case the network news + + align:start position:0% +but in any case the network news + + + align:start position:0% +but in any case the network news +programs uh performed a function during + + align:start position:0% +programs uh performed a function during + + + align:start position:0% +programs uh performed a function during +this crisis that was like the function + + align:start position:0% +this crisis that was like the function + + + align:start position:0% +this crisis that was like the function +they performed earlier when they when + + align:start position:0% +they performed earlier when they when + + + align:start position:0% +they performed earlier when they when +the Kennedy assassination was a dramatic + + align:start position:0% +the Kennedy assassination was a dramatic + + + align:start position:0% +the Kennedy assassination was a dramatic +example of it but there have been others + + align:start position:0% +example of it but there have been others + + + align:start position:0% +example of it but there have been others +uh and in those times the consensus uh + + align:start position:0% +uh and in those times the consensus uh + + + align:start position:0% +uh and in those times the consensus uh +reparative function the ritual function + + align:start position:0% +reparative function the ritual function + + + align:start position:0% +reparative function the ritual function +of Television becomes explicit + + align:start position:0% +of Television becomes explicit + + + align:start position:0% +of Television becomes explicit +impossible to miss but the argument but + + align:start position:0% +impossible to miss but the argument but + + + align:start position:0% +impossible to miss but the argument but +our argument in this course is is that + + align:start position:0% +our argument in this course is is that + + + align:start position:0% +our argument in this course is is that +that process that that function is + + align:start position:0% +that process that that function is + + + align:start position:0% +that process that that function is +always implicit and that that's always + + align:start position:0% +always implicit and that that's always + + + align:start position:0% +always implicit and that that's always +one aspect of what television has been + + align:start position:0% +one aspect of what television has been + + + align:start position:0% +one aspect of what television has been +doing and continues in some partial way + + align:start position:0% +doing and continues in some partial way + + + align:start position:0% +doing and continues in some partial way +to do in American societ so let me say a + + align:start position:0% +to do in American societ so let me say a + + + align:start position:0% +to do in American societ so let me say a +little bit more then about about um uh + + align:start position:0% +little bit more then about about um uh + + + align:start position:0% +little bit more then about about um uh +what my notion of consensus narrative + + align:start position:0% +what my notion of consensus narrative + + + align:start position:0% +what my notion of consensus narrative +and again I'm drawing out strains that + + align:start position:0% +and again I'm drawing out strains that + + + align:start position:0% +and again I'm drawing out strains that +are fully defined in the essay I hope + + align:start position:0% +are fully defined in the essay I hope + + + align:start position:0% +are fully defined in the essay I hope +you have read and will will reread + + align:start position:0% +you have read and will will reread + + + align:start position:0% +you have read and will will reread +closely these consensus systems have + + align:start position:0% +closely these consensus systems have + + + align:start position:0% +closely these consensus systems have +particular qualities that are worth + + align:start position:0% +particular qualities that are worth + + + align:start position:0% +particular qualities that are worth +emphasizing and they have three features + + align:start position:0% +emphasizing and they have three features + + + align:start position:0% +emphasizing and they have three features +in particular they are accessible + + align:start position:0% +in particular they are accessible + + + align:start position:0% +in particular they are accessible +they're conservative and they're + + align:start position:0% +they're conservative and they're + + + align:start position:0% +they're conservative and they're +collaborative let me talk about each in + + align:start position:0% +collaborative let me talk about each in + + + align:start position:0% +collaborative let me talk about each in +turn and I I Define these much more + + align:start position:0% +turn and I I Define these much more + + + align:start position:0% +turn and I I Define these much more +elaborately and fully in in in the essay + + align:start position:0% +elaborately and fully in in in the essay + + + align:start position:0% +elaborately and fully in in in the essay +uh let's start with the middle one + + align:start position:0% +uh let's start with the middle one + + + align:start position:0% +uh let's start with the middle one +conservative because it may be the most + + align:start position:0% +conservative because it may be the most + + + align:start position:0% +conservative because it may be the most +important they're deeply conservative + + align:start position:0% +important they're deeply conservative + + + align:start position:0% +important they're deeply conservative +media because they have to be if they're + + align:start position:0% +media because they have to be if they're + + + align:start position:0% +media because they have to be if they're +at the center of the society if + + align:start position:0% +at the center of the society if + + + align:start position:0% +at the center of the society if +everybody quote it's not really + + align:start position:0% +everybody quote it's not really + + + align:start position:0% +everybody quote it's not really +everybody at a certain point the the + + align:start position:0% +everybody at a certain point the the + + + align:start position:0% +everybody at a certain point the the +dominant consensus in American society + + align:start position:0% +dominant consensus in American society + + + align:start position:0% +dominant consensus in American society +in the 1950s did not acknowledge people + + align:start position:0% +in the 1950s did not acknowledge people + + + align:start position:0% +in the 1950s did not acknowledge people +of color so so the consensus and and so + + align:start position:0% +of color so so the consensus and and so + + + align:start position:0% +of color so so the consensus and and so +one of the reasons we want to look at + + align:start position:0% +one of the reasons we want to look at + + + align:start position:0% +one of the reasons we want to look at +consensus media is not because not + + align:start position:0% +consensus media is not because not + + + align:start position:0% +consensus media is not because not +because the values they articulate are + + align:start position:0% +because the values they articulate are + + + align:start position:0% +because the values they articulate are +are necessarily ones we would Embrace + + align:start position:0% +are necessarily ones we would Embrace + + + align:start position:0% +are necessarily ones we would Embrace +but because they can also tell us how + + align:start position:0% +but because they can also tell us how + + + align:start position:0% +but because they can also tell us how +the society defines itself what the they + + align:start position:0% +the society defines itself what the they + + + align:start position:0% +the society defines itself what the they +they're they're incredibly important + + align:start position:0% +they're they're incredibly important + + + align:start position:0% +they're they're incredibly important +media for cultural + + align:start position:0% +media for cultural + + + align:start position:0% +media for cultural +historians uh They Also may have + + align:start position:0% +historians uh They Also may have + + + align:start position:0% +historians uh They Also may have +artistic value at a certain point but + + align:start position:0% +artistic value at a certain point but + + + align:start position:0% +artistic value at a certain point but +they're but but from a historical or + + align:start position:0% +they're but but from a historical or + + + align:start position:0% +they're but but from a historical or +anthropological perspective they are + + align:start position:0% +anthropological perspective they are + + + align:start position:0% +anthropological perspective they are +really interesting to study they tell us + + align:start position:0% +really interesting to study they tell us + + + align:start position:0% +really interesting to study they tell us +more about Society uh the society they + + align:start position:0% +more about Society uh the society they + + + align:start position:0% +more about Society uh the society they +represent and and embody then the + + align:start position:0% +represent and and embody then the + + + align:start position:0% +represent and and embody then the +subcultural forms do the subcultural + + align:start position:0% +subcultural forms do the subcultural + + + align:start position:0% +subcultural forms do the subcultural +forms reveal things about Society too + + align:start position:0% +forms reveal things about Society too + + + align:start position:0% +forms reveal things about Society too +but not in the same way that consensus + + align:start position:0% +but not in the same way that consensus + + + align:start position:0% +but not in the same way that consensus +systems do so that's one of the great + + align:start position:0% +systems do so that's one of the great + + + align:start position:0% +systems do so that's one of the great +justifications for studying television + + align:start position:0% +justifications for studying television + + + align:start position:0% +justifications for studying television +closely is that it is a it tells us a + + align:start position:0% +closely is that it is a it tells us a + + + align:start position:0% +closely is that it is a it tells us a +lot if we study it intelligently and + + align:start position:0% +lot if we study it intelligently and + + + align:start position:0% +lot if we study it intelligently and +with the proper degree of skepticism and + + align:start position:0% +with the proper degree of skepticism and + + + align:start position:0% +with the proper degree of skepticism and +theoretical sophistication we can learn + + align:start position:0% +theoretical sophistication we can learn + + + align:start position:0% +theoretical sophistication we can learn +a great deal about the society embodied + + align:start position:0% +a great deal about the society embodied + + + align:start position:0% +a great deal about the society embodied +in it mirrored in its stories it's not a + + align:start position:0% +in it mirrored in its stories it's not a + + + align:start position:0% +in it mirrored in its stories it's not a +onetoone simple mirroring and and that's + + align:start position:0% +onetoone simple mirroring and and that's + + + align:start position:0% +onetoone simple mirroring and and that's +why I want to put the word consensus in + + align:start position:0% +why I want to put the word consensus in + + + align:start position:0% +why I want to put the word consensus in +quotations right I don't mean that it's + + align:start position:0% +quotations right I don't mean that it's + + + align:start position:0% +quotations right I don't mean that it's +a true consensus I don't mean everyone's + + align:start position:0% +a true consensus I don't mean everyone's + + + align:start position:0% +a true consensus I don't mean everyone's +voice is really there but I mean the + + align:start position:0% +voice is really there but I mean the + + + align:start position:0% +voice is really there but I mean the +society pretends that everyone's voice + + align:start position:0% +society pretends that everyone's voice + + + align:start position:0% +society pretends that everyone's voice +is there the society pretends that the + + align:start position:0% +is there the society pretends that the + + + align:start position:0% +is there the society pretends that the +values that are promulgated and taken + + align:start position:0% +values that are promulgated and taken + + + align:start position:0% +values that are promulgated and taken +for granted the values that are embedded + + align:start position:0% +for granted the values that are embedded + + + align:start position:0% +for granted the values that are embedded +in the consensus system are the values + + align:start position:0% +in the consensus system are the values + + + align:start position:0% +in the consensus system are the values +of the whole society and we can + + align:start position:0% +of the whole society and we can + + + align:start position:0% +of the whole society and we can +recognize the limitations of those + + align:start position:0% +recognize the limitations of those + + + align:start position:0% +recognize the limitations of those +values if we look closely at at those at + + align:start position:0% +values if we look closely at at those at + + + align:start position:0% +values if we look closely at at those at +those stories imagine what uh we might + + align:start position:0% +those stories imagine what uh we might + + + align:start position:0% +those stories imagine what uh we might +learn then if we went into the consensus + + align:start position:0% +learn then if we went into the consensus + + + align:start position:0% +learn then if we went into the consensus +what would it be radio or some form of + + align:start position:0% +what would it be radio or some form of + + + align:start position:0% +what would it be radio or some form of +some some combination of print media in + + align:start position:0% +some some combination of print media in + + + align:start position:0% +some some combination of print media in +the in the in in Nazi Germany in the in + + align:start position:0% +the in the in in Nazi Germany in the in + + + align:start position:0% +the in the in in Nazi Germany in the in +the in in the late 30s and 40s what we + + align:start position:0% +the in in the late 30s and 40s what we + + + align:start position:0% +the in in the late 30s and 40s what we +would find is a consensus that agreed + + align:start position:0% +would find is a consensus that agreed + + + align:start position:0% +would find is a consensus that agreed +that Jews were vermin + + align:start position:0% +that Jews were vermin + + + align:start position:0% +that Jews were vermin +right so I I don't mean to suggest that + + align:start position:0% +right so I I don't mean to suggest that + + + align:start position:0% +right so I I don't mean to suggest that +I don't want to I don't want to put a a + + align:start position:0% +I don't want to I don't want to put a a + + + align:start position:0% +I don't want to I don't want to put a a +a moral valuation on the term consensus + + align:start position:0% +a moral valuation on the term consensus + + + align:start position:0% +a moral valuation on the term consensus +for our purposes I want it to be a + + align:start position:0% +for our purposes I want it to be a + + + align:start position:0% +for our purposes I want it to be a +descriptor right not a not a valuation + + align:start position:0% +descriptor right not a not a valuation + + + align:start position:0% +descriptor right not a not a valuation +but just a descriptive a way of + + align:start position:0% +but just a descriptive a way of + + + align:start position:0% +but just a descriptive a way of +describing the role that these media + + align:start position:0% +describing the role that these media + + + align:start position:0% +describing the role that these media +play in a particular culture okay so + + align:start position:0% +play in a particular culture okay so + + + align:start position:0% +play in a particular culture okay so +let's talk about its conservative + + align:start position:0% +let's talk about its conservative + + + align:start position:0% +let's talk about its conservative +function it has to be conservative + + align:start position:0% +function it has to be conservative + + + align:start position:0% +function it has to be conservative +because it has to appeal across so many + + align:start position:0% +because it has to appeal across so many + + + align:start position:0% +because it has to appeal across so many +boundaries and that means that certain + + align:start position:0% +boundaries and that means that certain + + + align:start position:0% +boundaries and that means that certain +kinds of emergent or radical Notions + + align:start position:0% +kinds of emergent or radical Notions + + + align:start position:0% +kinds of emergent or radical Notions +which would offend large proportions of + + align:start position:0% +which would offend large proportions of + + + align:start position:0% +which would offend large proportions of +the population won't won't work on the + + align:start position:0% +the population won't won't work on the + + + align:start position:0% +the population won't won't work on the +meeting so it's conservative in terms of + + align:start position:0% +meeting so it's conservative in terms of + + + align:start position:0% +meeting so it's conservative in terms of +its content in terms of the belief + + align:start position:0% +its content in terms of the belief + + + align:start position:0% +its content in terms of the belief +systems and values that it will + + align:start position:0% +systems and values that it will + + + align:start position:0% +systems and values that it will +promulgate right and that's why in the + + align:start position:0% +promulgate right and that's why in the + + + align:start position:0% +promulgate right and that's why in the +early 50s the idea of the F of the + + align:start position:0% +early 50s the idea of the F of the + + + align:start position:0% +early 50s the idea of the F of the +nuclear family with the husband who + + align:start position:0% +nuclear family with the husband who + + + align:start position:0% +nuclear family with the husband who +works and the wife who stays at home was + + align:start position:0% +works and the wife who stays at home was + + + align:start position:0% +works and the wife who stays at home was +a was a staple a standard feature and + + align:start position:0% +a was a staple a standard feature and + + + align:start position:0% +a was a staple a standard feature and +even though there was a kind of + + align:start position:0% +even though there was a kind of + + + align:start position:0% +even though there was a kind of +subversive energy in the comic ways in + + align:start position:0% +subversive energy in the comic ways in + + + align:start position:0% +subversive energy in the comic ways in +which in many of those families The Lucy + + align:start position:0% +which in many of those families The Lucy + + + align:start position:0% +which in many of those families The Lucy +Show being a dramatic example of it the + + align:start position:0% +Show being a dramatic example of it the + + + align:start position:0% +Show being a dramatic example of it the +wife seemed the plot seemed again and + + align:start position:0% +wife seemed the plot seemed again and + + + align:start position:0% +wife seemed the plot seemed again and +again to dramatize a kind of discontent + + align:start position:0% +again to dramatize a kind of discontent + + + align:start position:0% +again to dramatize a kind of discontent +with that Arrangement the truth of the + + align:start position:0% +with that Arrangement the truth of the + + + align:start position:0% +with that Arrangement the truth of the +matter is that it was exact comedy + + align:start position:0% +matter is that it was exact comedy + + + align:start position:0% +matter is that it was exact comedy +always depends upon what are thought to + + align:start position:0% +always depends upon what are thought to + + + align:start position:0% +always depends upon what are thought to +be departures from the norm right uh if + + align:start position:0% +be departures from the norm right uh if + + + align:start position:0% +be departures from the norm right uh if +the norm is violated it seemed to be it + + align:start position:0% +the norm is violated it seemed to be it + + + align:start position:0% +the norm is violated it seemed to be it +seemed to be comical and funny another + + align:start position:0% +seemed to be comical and funny another + + + align:start position:0% +seemed to be comical and funny another +kind of situation comedy from this early + + align:start position:0% +kind of situation comedy from this early + + + align:start position:0% +kind of situation comedy from this early +period is a situation comedy in which + + align:start position:0% +period is a situation comedy in which + + + align:start position:0% +period is a situation comedy in which +the wife is missing we can call them uh + + align:start position:0% +the wife is missing we can call them uh + + + align:start position:0% +the wife is missing we can call them uh +and and in which the female figure is + + align:start position:0% +and and in which the female figure is + + + align:start position:0% +and and in which the female figure is +replaced the the the wife and mother + + align:start position:0% +replaced the the the wife and mother + + + align:start position:0% +replaced the the the wife and mother +figure is replaced by a comical often + + align:start position:0% +figure is replaced by a comical often + + + align:start position:0% +figure is replaced by a comical often +desexualized male figure can you can you + + align:start position:0% +desexualized male figure can you can you + + + align:start position:0% +desexualized male figure can you can you +think of shows like + + align:start position:0% +think of shows like + + + align:start position:0% +think of shows like +that my three sons is a terrific example + + align:start position:0% +that my three sons is a terrific example + + + align:start position:0% +that my three sons is a terrific example +and it ran for a long time another how + + align:start position:0% +and it ran for a long time another how + + + align:start position:0% +and it ran for a long time another how +many of you have seen my three sons a + + align:start position:0% +many of you have seen my three sons a + + + align:start position:0% +many of you have seen my three sons a +couple of you uh it's available it's an + + align:start position:0% +couple of you uh it's available it's an + + + align:start position:0% +couple of you uh it's available it's an +incredibly silly show in many ways but + + align:start position:0% +incredibly silly show in many ways but + + + align:start position:0% +incredibly silly show in many ways but +what what makes it interesting in a + + align:start position:0% +what what makes it interesting in a + + + align:start position:0% +what what makes it interesting in a +certain sense it it it draws a lot of + + align:start position:0% +certain sense it it it draws a lot of + + + align:start position:0% +certain sense it it it draws a lot of +its comedy from the absence of a of the + + align:start position:0% +its comedy from the absence of a of the + + + align:start position:0% +its comedy from the absence of a of the +female figure and the and the the the + + align:start position:0% +female figure and the and the the the + + + align:start position:0% +female figure and the and the the the +male figure who often is seen in wearing + + align:start position:0% +male figure who often is seen in wearing + + + align:start position:0% +male figure who often is seen in wearing +aprons and doing and cooking badly and + + align:start position:0% +aprons and doing and cooking badly and + + + align:start position:0% +aprons and doing and cooking badly and +so forth who replace inadequately + + align:start position:0% +so forth who replace inadequately + + + align:start position:0% +so forth who replace inadequately +replaces another such show is called + + align:start position:0% +replaces another such show is called + + + align:start position:0% +replaces another such show is called +Bachelor Father there are series of them + + align:start position:0% +Bachelor Father there are series of them + + + align:start position:0% +Bachelor Father there are series of them +another one a little bit later on was + + align:start position:0% +another one a little bit later on was + + + align:start position:0% +another one a little bit later on was +called uh um um + + align:start position:0% +called uh um um + + + align:start position:0% +called uh um um +full Full House Full House well that's a + + align:start position:0% +full Full House Full House well that's a + + + align:start position:0% +full Full House Full House well that's a +very late one yes full house but but see + + align:start position:0% +very late one yes full house but but see + + + align:start position:0% +very late one yes full house but but see +but by the time we get to Full House or + + align:start position:0% +but by the time we get to Full House or + + + align:start position:0% +but by the time we get to Full House or +my three dads we're in a different + + align:start position:0% +my three dads we're in a different + + + align:start position:0% +my three dads we're in a different +cultural dispensation and the the there + + align:start position:0% +cultural dispensation and the the there + + + align:start position:0% +cultural dispensation and the the there +it's there the absence of the female + + align:start position:0% +it's there the absence of the female + + + align:start position:0% +it's there the absence of the female +figure has a different cultural meaning + + align:start position:0% +figure has a different cultural meaning + + + align:start position:0% +figure has a different cultural meaning +from what it had in the 50s and early + + align:start position:0% +from what it had in the 50s and early + + + align:start position:0% +from what it had in the 50s and early +60s there there because what's happened + + align:start position:0% +60s there there because what's happened + + + align:start position:0% +60s there there because what's happened +is the nuclear family is no longer the + + align:start position:0% +is the nuclear family is no longer the + + + align:start position:0% +is the nuclear family is no longer the +norm by the time we get to a show like + + align:start position:0% +norm by the time we get to a show like + + + align:start position:0% +norm by the time we get to a show like +my three dads right + + align:start position:0% +my three dads right + + + align:start position:0% +my three dads right +so yes Wally put on your put on your uh + + align:start position:0% +so yes Wally put on your put on your uh + + + align:start position:0% +so yes Wally put on your put on your uh +my question is actually when was the uh + + align:start position:0% +my question is actually when was the uh + + + align:start position:0% +my question is actually when was the uh +when is when did the play The Odd Couple + + align:start position:0% +when is when did the play The Odd Couple + + + align:start position:0% +when is when did the play The Odd Couple +was it written I I don't know I assume + + align:start position:0% +was it written I I don't know I assume + + + align:start position:0% +was it written I I don't know I assume +the play came before the show yes the + + align:start position:0% +the play came before the show yes the + + + align:start position:0% +the play came before the show yes the +play precedes the precedes the + + align:start position:0% +play precedes the precedes the + + + align:start position:0% +play precedes the precedes the +television show I don't know the date + + align:start position:0% +television show I don't know the date + + + align:start position:0% +television show I don't know the date +but + + align:start position:0% +but + + + align:start position:0% +but +uh late 50s early 60s is my + + align:start position:0% +uh late 50s early 60s is my + + + align:start position:0% +uh late 50s early 60s is my +guess my guess but let me come back to + + align:start position:0% +guess my guess but let me come back to + + + align:start position:0% +guess my guess but let me come back to +this for so so what I'm going saying is + + align:start position:0% +this for so so what I'm going saying is + + + align:start position:0% +this for so so what I'm going saying is +that in the early in the early phase the + + align:start position:0% +that in the early in the early phase the + + + align:start position:0% +that in the early in the early phase the +the the situation comedy with the absent + + align:start position:0% +the the situation comedy with the absent + + + align:start position:0% +the the situation comedy with the absent +female figure doesn't actually signify + + align:start position:0% +female figure doesn't actually signify + + + align:start position:0% +female figure doesn't actually signify +the notion that there's a discontent in + + align:start position:0% +the notion that there's a discontent in + + + align:start position:0% +the notion that there's a discontent in +the society with the norm of the nuclear + + align:start position:0% +the society with the norm of the nuclear + + + align:start position:0% +the society with the norm of the nuclear +family it signifies the opposite what's + + align:start position:0% +family it signifies the opposite what's + + + align:start position:0% +family it signifies the opposite what's +comical what what is a continuous source + + align:start position:0% +comical what what is a continuous source + + + align:start position:0% +comical what what is a continuous source +of Comedy is this failure to meet what + + align:start position:0% +of Comedy is this failure to meet what + + + align:start position:0% +of Comedy is this failure to meet what +the Norms of society assume and one + + align:start position:0% +the Norms of society assume and one + + + align:start position:0% +the Norms of society assume and one +thing one thing people always laugh at + + align:start position:0% +thing one thing people always laugh at + + + align:start position:0% +thing one thing people always laugh at +or is are violations of what is thought + + align:start position:0% +or is are violations of what is thought + + + align:start position:0% +or is are violations of what is thought +to be an utter Norm in other words what + + align:start position:0% +to be an utter Norm in other words what + + + align:start position:0% +to be an utter Norm in other words what +it's it's as if the notion of the + + align:start position:0% +it's it's as if the notion of the + + + align:start position:0% +it's it's as if the notion of the +nuclear family was so naturalized was + + align:start position:0% +nuclear family was so naturalized was + + + align:start position:0% +nuclear family was so naturalized was +understood so deeply to be a part of + + align:start position:0% +understood so deeply to be a part of + + + align:start position:0% +understood so deeply to be a part of +nature to be not not not a construction + + align:start position:0% +nature to be not not not a construction + + + align:start position:0% +nature to be not not not a construction +something that could change but a but a + + align:start position:0% +something that could change but a but a + + + align:start position:0% +something that could change but a but a +but a part of the natural order of the + + align:start position:0% +but a part of the natural order of the + + + align:start position:0% +but a part of the natural order of the +world not part of a particular social + + align:start position:0% +world not part of a particular social + + + align:start position:0% +world not part of a particular social +system that variations from it were seen + + align:start position:0% +system that variations from it were seen + + + align:start position:0% +system that variations from it were seen +as comically unnatural right and it's + + align:start position:0% +as comically unnatural right and it's + + + align:start position:0% +as comically unnatural right and it's +only later that the variations begin to + + align:start position:0% +only later that the variations begin to + + + align:start position:0% +only later that the variations begin to +take on uh a a conscious sense that wait + + align:start position:0% +take on uh a a conscious sense that wait + + + align:start position:0% +take on uh a a conscious sense that wait +a minute this is a constructed relation + + align:start position:0% +a minute this is a constructed relation + + + align:start position:0% +a minute this is a constructed relation +and many many many many families are + + align:start position:0% +and many many many many families are + + + align:start position:0% +and many many many many families are +actually not organized on the on the + + align:start position:0% +actually not organized on the on the + + + align:start position:0% +actually not organized on the on the +nuclear family model and maybe the + + align:start position:0% +nuclear family model and maybe the + + + align:start position:0% +nuclear family model and maybe the +nuclear family model isn't so isn't so + + align:start position:0% +nuclear family model isn't so isn't so + + + align:start position:0% +nuclear family model isn't so isn't so +isn't so Universal and isn't so is isn't + + align:start position:0% +isn't so Universal and isn't so is isn't + + + align:start position:0% +isn't so Universal and isn't so is isn't +isn't so natural as we had originally + + align:start position:0% +isn't so natural as we had originally + + + align:start position:0% +isn't so natural as we had originally +thought but that's a process that's a + + align:start position:0% +thought but that's a process that's a + + + align:start position:0% +thought but that's a process that's a +process that actually in a certain sense + + align:start position:0% +process that actually in a certain sense + + + align:start position:0% +process that actually in a certain sense +could be said to be articulated or + + align:start position:0% +could be said to be articulated or + + + align:start position:0% +could be said to be articulated or +enacted that that recognition that the + + align:start position:0% +enacted that that recognition that the + + + align:start position:0% +enacted that that recognition that the +nuclear family is not the only way we + + align:start position:0% +nuclear family is not the only way we + + + align:start position:0% +nuclear family is not the only way we +can think about families or the that the + + align:start position:0% +can think about families or the that the + + + align:start position:0% +can think about families or the that the +housewife is not the only role we can + + align:start position:0% +housewife is not the only role we can + + + align:start position:0% +housewife is not the only role we can +think of for women that's a process + + align:start position:0% +think of for women that's a process + + + align:start position:0% +think of for women that's a process +that's actually actually enacted in the + + align:start position:0% +that's actually actually enacted in the + + + align:start position:0% +that's actually actually enacted in the +course of the development of particular + + align:start position:0% +course of the development of particular + + + align:start position:0% +course of the development of particular +genres on Tel so that we so that so that + + align:start position:0% +genres on Tel so that we so that so that + + + align:start position:0% +genres on Tel so that we so that so that +what I'm saying in a certain sense is + + align:start position:0% +what I'm saying in a certain sense is + + + align:start position:0% +what I'm saying in a certain sense is +that is that um the conservative + + align:start position:0% +that is that um the conservative + + + align:start position:0% +that is that um the conservative +features of consensus Medi of of a + + align:start position:0% +features of consensus Medi of of a + + + align:start position:0% +features of consensus Medi of of a +consensus medium are are particularly + + align:start position:0% +consensus medium are are particularly + + + align:start position:0% +consensus medium are are particularly +important because when we see those + + align:start position:0% +important because when we see those + + + align:start position:0% +important because when we see those +those uh that belief structure changing + + align:start position:0% +those uh that belief structure changing + + + align:start position:0% +those uh that belief structure changing +in certain ways certain basic + + align:start position:0% +in certain ways certain basic + + + align:start position:0% +in certain ways certain basic +assumptions that the media might be + + align:start position:0% +assumptions that the media might be + + + align:start position:0% +assumptions that the media might be +making about essential features of the + + align:start position:0% +making about essential features of the + + + align:start position:0% +making about essential features of the +society we can say that those changes + + align:start position:0% +society we can say that those changes + + + align:start position:0% +society we can say that those changes +are really signified in a way that would + + align:start position:0% +are really signified in a way that would + + + align:start position:0% +are really signified in a way that would +not be true if we were looking at a + + align:start position:0% +not be true if we were looking at a + + + align:start position:0% +not be true if we were looking at a +medium that that that was U defined only + + align:start position:0% +medium that that that was U defined only + + + align:start position:0% +medium that that that was U defined only +by a particular narrow subculture of + + align:start position:0% +by a particular narrow subculture of + + + align:start position:0% +by a particular narrow subculture of +society it would sign it signifies much + + align:start position:0% +society it would sign it signifies much + + + align:start position:0% +society it would sign it signifies much +less uh uh if if the avangard novel + + align:start position:0% +less uh uh if if the avangard novel + + + align:start position:0% +less uh uh if if the avangard novel +doesn't respect the nuclear family than + + align:start position:0% +doesn't respect the nuclear family than + + + align:start position:0% +doesn't respect the nuclear family than +it does if the if the television system + + align:start position:0% +it does if the if the television system + + + align:start position:0% +it does if the if the television system +is beginning to say wait a minute I can + + align:start position:0% +is beginning to say wait a minute I can + + + align:start position:0% +is beginning to say wait a minute I can +imagine families where the woman is + + align:start position:0% +imagine families where the woman is + + + align:start position:0% +imagine families where the woman is +dominant I can imagine families in which + + align:start position:0% +dominant I can imagine families in which + + + align:start position:0% +dominant I can imagine families in which +there is no father I can imagine I can + + align:start position:0% +there is no father I can imagine I can + + + align:start position:0% +there is no father I can imagine I can +imagine families in which the children + + align:start position:0% +imagine families in which the children + + + align:start position:0% +imagine families in which the children +are smarter than the adults which is in + + align:start position:0% +are smarter than the adults which is in + + + align:start position:0% +are smarter than the adults which is in +one of the things that begins to in a + + align:start position:0% +one of the things that begins to in a + + + align:start position:0% +one of the things that begins to in a +disturbing way happen at a certain point + + align:start position:0% +disturbing way happen at a certain point + + + align:start position:0% +disturbing way happen at a certain point +in the history of of of family sitcoms + + align:start position:0% +in the history of of of family sitcoms + + + align:start position:0% +in the history of of of family sitcoms +right so so there so so a consensus + + align:start position:0% +right so so there so so a consensus + + + align:start position:0% +right so so there so so a consensus +system is conservative in content but + + align:start position:0% +system is conservative in content but + + + align:start position:0% +system is conservative in content but +it's it's also conservative in form in + + align:start position:0% +it's it's also conservative in form in + + + align:start position:0% +it's it's also conservative in form in +format that is to say the basic you it + + align:start position:0% +format that is to say the basic you it + + + align:start position:0% +format that is to say the basic you it +will not it will not engage in what we + + align:start position:0% +will not it will not engage in what we + + + align:start position:0% +will not it will not engage in what we +might think of as modernist or avangard + + align:start position:0% +might think of as modernist or avangard + + + align:start position:0% +might think of as modernist or avangard +or uh narrative strategies it's it's + + align:start position:0% +or uh narrative strategies it's it's + + + align:start position:0% +or uh narrative strategies it's it's +aesthetically + + align:start position:0% +aesthetically + + + align:start position:0% +aesthetically +conservative right formally conservative + + align:start position:0% +conservative right formally conservative + + + align:start position:0% +conservative right formally conservative +as well as conservative in content as + + align:start position:0% +as well as conservative in content as + + + align:start position:0% +as well as conservative in content as +well as conservative in ide for exactly + + align:start position:0% +well as conservative in ide for exactly + + + align:start position:0% +well as conservative in ide for exactly +the same reason uh and that's why it + + align:start position:0% +the same reason uh and that's why it + + + align:start position:0% +the same reason uh and that's why it +signifies very greatly that at a certain + + align:start position:0% +signifies very greatly that at a certain + + + align:start position:0% +signifies very greatly that at a certain +point in the late 70s or early 80s we + + align:start position:0% +point in the late 70s or early 80s we + + + align:start position:0% +point in the late 70s or early 80s we +begin to get television shows that use + + align:start position:0% +begin to get television shows that use + + + align:start position:0% +begin to get television shows that use +complex flashback structures that make + + align:start position:0% +complex flashback structures that make + + + align:start position:0% +complex flashback structures that make +it much more difficult to follow the + + align:start position:0% +it much more difficult to follow the + + + align:start position:0% +it much more difficult to follow the +narrative instead of having a + + align:start position:0% +narrative instead of having a + + + align:start position:0% +narrative instead of having a +straightforward narrative which is + + align:start position:0% +straightforward narrative which is + + + align:start position:0% +straightforward narrative which is +organized chronologically you begin to + + align:start position:0% +organized chronologically you begin to + + + align:start position:0% +organized chronologically you begin to +get television programs in which the + + align:start position:0% +get television programs in which the + + + align:start position:0% +get television programs in which the +chronology is disrupted in the way that + + align:start position:0% +chronology is disrupted in the way that + + + align:start position:0% +chronology is disrupted in the way that +the modern novel did at turn of the + + align:start position:0% +the modern novel did at turn of the + + + align:start position:0% +the modern novel did at turn of the +century right but but when television + + align:start position:0% +century right but but when television + + + align:start position:0% +century right but but when television +narrative begins to show modernist + + align:start position:0% +narrative begins to show modernist + + + align:start position:0% +narrative begins to show modernist +Tendencies it suggests something among + + align:start position:0% +Tendencies it suggests something among + + + align:start position:0% +Tendencies it suggests something among +other things about the breakdown of the + + align:start position:0% +other things about the breakdown of the + + + align:start position:0% +other things about the breakdown of the +consensus function that television had + + align:start position:0% +consensus function that television had + + + align:start position:0% +consensus function that television had +been performing in American so it's + + align:start position:0% +been performing in American so it's + + + align:start position:0% +been performing in American so it's +conservative ideologically and + + align:start position:0% +conservative ideologically and + + + align:start position:0% +conservative ideologically and +conservative formally or AR or + + align:start position:0% +conservative formally or AR or + + + align:start position:0% +conservative formally or AR or +aesthetically it's accessible and this + + align:start position:0% +aesthetically it's accessible and this + + + align:start position:0% +aesthetically it's accessible and this +that is to say it speaks this is an + + align:start position:0% +that is to say it speaks this is an + + + align:start position:0% +that is to say it speaks this is an +aspect of its conservatism it's + + align:start position:0% +aspect of its conservatism it's + + + align:start position:0% +aspect of its conservatism it's +accessible because to be a consensus + + align:start position:0% +accessible because to be a consensus + + + align:start position:0% +accessible because to be a consensus +medium it has to speak broadly to + + align:start position:0% +medium it has to speak broadly to + + + align:start position:0% +medium it has to speak broadly to +everyone it has to use it has to use a + + align:start position:0% +everyone it has to use it has to use a + + + align:start position:0% +everyone it has to use it has to use a +common a shared language it will embody + + align:start position:0% +common a shared language it will embody + + + align:start position:0% +common a shared language it will embody +it will talk and and and utilize the + + align:start position:0% +it will talk and and and utilize the + + + align:start position:0% +it will talk and and and utilize the +myths and stories that are at the heart + + align:start position:0% +myths and stories that are at the heart + + + align:start position:0% +myths and stories that are at the heart +of the culture and it will communicate + + align:start position:0% +of the culture and it will communicate + + + align:start position:0% +of the culture and it will communicate +them and rehearse them again and again + + align:start position:0% +them and rehearse them again and again + + + align:start position:0% +them and rehearse them again and again +uh it's it and finally it's a + + align:start position:0% +uh it's it and finally it's a + + + align:start position:0% +uh it's it and finally it's a +collaborative medium in in the deepest + + align:start position:0% +collaborative medium in in the deepest + + + align:start position:0% +collaborative medium in in the deepest +possible sense it's collaborative first + + align:start position:0% +possible sense it's collaborative first + + + align:start position:0% +possible sense it's collaborative first +be uh in the case of movies or theater + + align:start position:0% +be uh in the case of movies or theater + + + align:start position:0% +be uh in the case of movies or theater +or television because many people + + align:start position:0% +or television because many people + + + align:start position:0% +or television because many people +collaborate to make the text there's no + + align:start position:0% +collaborate to make the text there's no + + + align:start position:0% +collaborate to make the text there's no +single author right no television + + align:start position:0% +single author right no television + + + align:start position:0% +single author right no television +program or movie actually has a single + + align:start position:0% +program or movie actually has a single + + + align:start position:0% +program or movie actually has a single +author the author is uh a writer a + + align:start position:0% +author the author is uh a writer a + + + align:start position:0% +author the author is uh a writer a +director the actors the there's that + + align:start position:0% +director the actors the there's that + + + align:start position:0% +director the actors the there's that +there's that kind of collaboration invol + + align:start position:0% +there's that kind of collaboration invol + + + align:start position:0% +there's that kind of collaboration invol +but that's the smallest aspect of the + + align:start position:0% +but that's the smallest aspect of the + + + align:start position:0% +but that's the smallest aspect of the +collaboration what else does it + + align:start position:0% +collaboration what else does it + + + align:start position:0% +collaboration what else does it +collaborate with the m the system also + + align:start position:0% +collaborate with the m the system also + + + align:start position:0% +collaborate with the m the system also +coll the the the story also collaborates + + align:start position:0% +coll the the the story also collaborates + + + align:start position:0% +coll the the the story also collaborates +with the understanding that the audience + + align:start position:0% +with the understanding that the audience + + + align:start position:0% +with the understanding that the audience +has of this material the audience is a + + align:start position:0% +has of this material the audience is a + + + align:start position:0% +has of this material the audience is a +is an active collaborator the audience + + align:start position:0% +is an active collaborator the audience + + + align:start position:0% +is an active collaborator the audience +is prior understanding of the generic + + align:start position:0% +is prior understanding of the generic + + + align:start position:0% +is prior understanding of the generic +forms that are that that they're + + align:start position:0% +forms that are that that they're + + + align:start position:0% +forms that are that that they're +watching the audience's prior + + align:start position:0% +watching the audience's prior + + + align:start position:0% +watching the audience's prior +understanding of the characters inside + + align:start position:0% +understanding of the characters inside + + + align:start position:0% +understanding of the characters inside +the story as a part of the collaboration + + align:start position:0% +the story as a part of the collaboration + + + align:start position:0% +the story as a part of the collaboration +but even more deeply than that there's a + + align:start position:0% +but even more deeply than that there's a + + + align:start position:0% +but even more deeply than that there's a +notion that that the wisdom the larger + + align:start position:0% +notion that that the wisdom the larger + + + align:start position:0% +notion that that the wisdom the larger +wisdom or wisdom system of the culture + + align:start position:0% +wisdom or wisdom system of the culture + + + align:start position:0% +wisdom or wisdom system of the culture +the larger story systems and myth + + align:start position:0% +the larger story systems and myth + + + align:start position:0% +the larger story systems and myth +systems of the culture are also lie + + align:start position:0% +systems of the culture are also lie + + + align:start position:0% +systems of the culture are also lie +behind and help to explain the content + + align:start position:0% +behind and help to explain the content + + + align:start position:0% +behind and help to explain the content +of consensus narrative so that uh if + + align:start position:0% +of consensus narrative so that uh if + + + align:start position:0% +of consensus narrative so that uh if +there are traditional Notions of + + align:start position:0% +there are traditional Notions of + + + align:start position:0% +there are traditional Notions of +individualism that have organized + + align:start position:0% +individualism that have organized + + + align:start position:0% +individualism that have organized +American society since the re + + align:start position:0% +American society since the re + + + align:start position:0% +American society since the re +evolutionary War those Notions of + + align:start position:0% +evolutionary War those Notions of + + + align:start position:0% +evolutionary War those Notions of +individualism are going to feed into and + + align:start position:0% +individualism are going to feed into and + + + align:start position:0% +individualism are going to feed into and +help to shape the stories that are told + + align:start position:0% +help to shape the stories that are told + + + align:start position:0% +help to shape the stories that are told +on its on the on the system's consensus + + align:start position:0% +on its on the on the system's consensus + + + align:start position:0% +on its on the on the system's consensus +medium so so this so the texts on a + + align:start position:0% +medium so so this so the texts on a + + + align:start position:0% +medium so so this so the texts on a +consensus medium collaborate not only + + align:start position:0% +consensus medium collaborate not only + + + align:start position:0% +consensus medium collaborate not only +with their own immediate ancestor texts + + align:start position:0% +with their own immediate ancestor texts + + + align:start position:0% +with their own immediate ancestor texts +and with but also with the older + + align:start position:0% +and with but also with the older + + + align:start position:0% +and with but also with the older +ancestor media and ancestor stories that + + align:start position:0% +ancestor media and ancestor stories that + + + align:start position:0% +ancestor media and ancestor stories that +are the + + align:start position:0% +are the + + + align:start position:0% +are the +shared that are the that are the shared + + align:start position:0% +shared that are the that are the shared + + + align:start position:0% +shared that are the that are the shared +possession of the of of the culture as a + + align:start position:0% +possession of the of of the culture as a + + + align:start position:0% +possession of the of of the culture as a +whole so in that sense consensus medium + + align:start position:0% +whole so in that sense consensus medium + + + align:start position:0% +whole so in that sense consensus medium +is a deeply collaborative system I try + + align:start position:0% +is a deeply collaborative system I try + + + align:start position:0% +is a deeply collaborative system I try +to embody this idea in that passage I in + + align:start position:0% +to embody this idea in that passage I in + + + align:start position:0% +to embody this idea in that passage I in +which I conclude the essay on television + + align:start position:0% +which I conclude the essay on television + + + align:start position:0% +which I conclude the essay on television +as an aesthetic medium in which I talk + + align:start position:0% +as an aesthetic medium in which I talk + + + align:start position:0% +as an aesthetic medium in which I talk +about that astonishing wonderful moment + + align:start position:0% +about that astonishing wonderful moment + + + align:start position:0% +about that astonishing wonderful moment +in Shakespeare from simine when the when + + align:start position:0% +in Shakespeare from simine when the when + + + align:start position:0% +in Shakespeare from simine when the when +when when uh standing over a dead body + + align:start position:0% +when when uh standing over a dead body + + + align:start position:0% +when when uh standing over a dead body +they sing This Magnificent durge to a + + align:start position:0% +they sing This Magnificent durge to a + + + align:start position:0% +they sing This Magnificent durge to a +person who appears to be dead it's one + + align:start position:0% +person who appears to be dead it's one + + + align:start position:0% +person who appears to be dead it's one +of the great elegies uh in in in English + + align:start position:0% +of the great elegies uh in in in English + + + align:start position:0% +of the great elegies uh in in in English +literature and The crucial lines are + + align:start position:0% +literature and The crucial lines are + + + align:start position:0% +literature and The crucial lines are +golden Lads and girls almost must as + + align:start position:0% +golden Lads and girls almost must as + + + align:start position:0% +golden Lads and girls almost must as +chimney sweepers come to dust and they + + align:start position:0% +chimney sweepers come to dust and they + + + align:start position:0% +chimney sweepers come to dust and they +are beautiful and magnificent lines + + align:start position:0% +are beautiful and magnificent lines + + + align:start position:0% +are beautiful and magnificent lines +aren't they and they are consoling lines + + align:start position:0% +aren't they and they are consoling lines + + + align:start position:0% +aren't they and they are consoling lines +in a certain way the lines take on a + + align:start position:0% +in a certain way the lines take on a + + + align:start position:0% +in a certain way the lines take on a +kind of richness in resonance when we + + align:start position:0% +kind of richness in resonance when we + + + align:start position:0% +kind of richness in resonance when we +recognize that the term in Shakespeare's + + align:start position:0% +recognize that the term in Shakespeare's + + + align:start position:0% +recognize that the term in Shakespeare's +native + + align:start position:0% +native + + + align:start position:0% +native +Warwickshire the term golden Lads refers + + align:start position:0% +Warwickshire the term golden Lads refers + + + align:start position:0% +Warwickshire the term golden Lads refers +literally to the flower we call the + + align:start position:0% +literally to the flower we call the + + + align:start position:0% +literally to the flower we call the +dandelion which has a golden cap when + + align:start position:0% +dandelion which has a golden cap when + + + align:start position:0% +dandelion which has a golden cap when +it's young and strong and then when it + + align:start position:0% +it's young and strong and then when it + + + align:start position:0% +it's young and strong and then when it +ages when it's about to when it goes to + + align:start position:0% +ages when it's about to when it goes to + + + align:start position:0% +ages when it's about to when it goes to +seed that cap turns into those they're + + align:start position:0% +seed that cap turns into those they're + + + align:start position:0% +seed that cap turns into those they're +very common here in New England right + + align:start position:0% +very common here in New England right + + + align:start position:0% +very common here in New England right +turns into a kind of set of white + + align:start position:0% +turns into a kind of set of white + + + align:start position:0% +turns into a kind of set of white +filaments and kids pick them and if they + + align:start position:0% +filaments and kids pick them and if they + + + align:start position:0% +filaments and kids pick them and if they +blow on them the seeds can be blown away + + align:start position:0% +blow on them the seeds can be blown away + + + align:start position:0% +blow on them the seeds can be blown away +right well so they they're golden Lads + + align:start position:0% +right well so they they're golden Lads + + + align:start position:0% +right well so they they're golden Lads +when they're young and they C why are + + align:start position:0% +when they're young and they C why are + + + align:start position:0% +when they're young and they C why are +they called chimney sweepers because + + align:start position:0% +they called chimney sweepers because + + + align:start position:0% +they called chimney sweepers because +chimney sweepers brooms in Shakespeare's + + align:start position:0% +chimney sweepers brooms in Shakespeare's + + + align:start position:0% +chimney sweepers brooms in Shakespeare's +day looked like those looked like those + + align:start position:0% +day looked like those looked like those + + + align:start position:0% +day looked like those looked like those +flowers when they've gone to seed and + + align:start position:0% +flowers when they've gone to seed and + + + align:start position:0% +flowers when they've gone to seed and +were actually they they had a rounded + + align:start position:0% +were actually they they had a rounded + + + align:start position:0% +were actually they they had a rounded +top like that and they were they because + + align:start position:0% +top like that and they were they because + + + align:start position:0% +top like that and they were they because +they were it was easier to clean + + align:start position:0% +they were it was easier to clean + + + align:start position:0% +they were it was easier to clean +chimneys with such a rounded brush so + + align:start position:0% +chimneys with such a rounded brush so + + + align:start position:0% +chimneys with such a rounded brush so +they called dandelions golden Lads when + + align:start position:0% +they called dandelions golden Lads when + + + align:start position:0% +they called dandelions golden Lads when +they were young and chimney sweepers + + align:start position:0% +they were young and chimney sweepers + + + align:start position:0% +they were young and chimney sweepers +when they were are close to death well + + align:start position:0% +when they were are close to death well + + + align:start position:0% +when they were are close to death well +that why is that so wonderful two + + align:start position:0% +that why is that so wonderful two + + + align:start position:0% +that why is that so wonderful two +reasons it's a it gives a kind of poetic + + align:start position:0% +reasons it's a it gives a kind of poetic + + + align:start position:0% +reasons it's a it gives a kind of poetic +resonance to the line because it links + + align:start position:0% +resonance to the line because it links + + + align:start position:0% +resonance to the line because it links +human human death with a cycle of the + + align:start position:0% +human human death with a cycle of the + + + align:start position:0% +human human death with a cycle of the +seasons golden Lads and girls all must + + align:start position:0% +seasons golden Lads and girls all must + + + align:start position:0% +seasons golden Lads and girls all must +as chimney sweepers come to dust the + + align:start position:0% +as chimney sweepers come to dust the + + + align:start position:0% +as chimney sweepers come to dust the +rich and the poor the Highborn and the + + align:start position:0% +rich and the poor the Highborn and the + + + align:start position:0% +rich and the poor the Highborn and the +low all die we share that with each + + align:start position:0% +low all die we share that with each + + + align:start position:0% +low all die we share that with each +other not just that we share that with + + align:start position:0% +other not just that we share that with + + + align:start position:0% +other not just that we share that with +nature with the natural process so it's + + align:start position:0% +nature with the natural process so it's + + + align:start position:0% +nature with the natural process so it's +a brilliant line but the most important + + align:start position:0% +a brilliant line but the most important + + + align:start position:0% +a brilliant line but the most important +thing for me is How Deeply collaborative + + align:start position:0% +thing for me is How Deeply collaborative + + + align:start position:0% +thing for me is How Deeply collaborative +it is because Shakespeare didn't invent + + align:start position:0% +it is because Shakespeare didn't invent + + + align:start position:0% +it is because Shakespeare didn't invent +the metaphor + + align:start position:0% +the metaphor + + + align:start position:0% +the metaphor +what grants the authority to the line is + + align:start position:0% +what grants the authority to the line is + + + align:start position:0% +what grants the authority to the line is +the common wisdom of the Elizabethan + + align:start position:0% +the common wisdom of the Elizabethan + + + align:start position:0% +the common wisdom of the Elizabethan +culture in which Shakespeare was born + + align:start position:0% +culture in which Shakespeare was born + + + align:start position:0% +culture in which Shakespeare was born +and the culture behind that because it + + align:start position:0% +and the culture behind that because it + + + align:start position:0% +and the culture behind that because it +was the native farmers in warshire who + + align:start position:0% +was the native farmers in warshire who + + + align:start position:0% +was the native farmers in warshire who +never read blank verse in their lives + + align:start position:0% +never read blank verse in their lives + + + align:start position:0% +never read blank verse in their lives +who came to call the dandelion golden + + align:start position:0% +who came to call the dandelion golden + + + align:start position:0% +who came to call the dandelion golden +Lads and chimney sweepers so what + + align:start position:0% +Lads and chimney sweepers so what + + + align:start position:0% +Lads and chimney sweepers so what +Shakespeare is doing there in a way is + + align:start position:0% +Shakespeare is doing there in a way is + + + align:start position:0% +Shakespeare is doing there in a way is +he's collaborating with his culture he's + + align:start position:0% +he's collaborating with his culture he's + + + align:start position:0% +he's collaborating with his culture he's +seizing on what we might call the common + + align:start position:0% +seizing on what we might call the common + + + align:start position:0% +seizing on what we might call the common +wisdom of his culture in order to + + align:start position:0% +wisdom of his culture in order to + + + align:start position:0% +wisdom of his culture in order to +express a comp an immensely complex Rich + + align:start position:0% +express a comp an immensely complex Rich + + + align:start position:0% +express a comp an immensely complex Rich +idea which in part belongs to the + + align:start position:0% +idea which in part belongs to the + + + align:start position:0% +idea which in part belongs to the +culture that's a very dramatic and + + align:start position:0% +culture that's a very dramatic and + + + align:start position:0% +culture that's a very dramatic and +poetic instance of this principle of + + align:start position:0% +poetic instance of this principle of + + + align:start position:0% +poetic instance of this principle of +collaboration that I think is operative + + align:start position:0% +collaboration that I think is operative + + + align:start position:0% +collaboration that I think is operative +on our on our popular media all the time + + align:start position:0% +on our on our popular media all the time + + + align:start position:0% +on our on our popular media all the time +and we are going to have occasions as we + + align:start position:0% +and we are going to have occasions as we + + + align:start position:0% +and we are going to have occasions as we +go on in this course to see one + + align:start position:0% +go on in this course to see one + + + align:start position:0% +go on in this course to see one +instances of such collaboration and of + + align:start position:0% +instances of such collaboration and of + + + align:start position:0% +instances of such collaboration and of +such of such U + + align:start position:0% +such of such U + + + align:start position:0% +such of such U +self-consciousness in our in our popular + + align:start position:0% +self-consciousness in our in our popular + + + align:start position:0% +self-consciousness in our in our popular +television programs that I think are at + + align:start position:0% +television programs that I think are at + + + align:start position:0% +television programs that I think are at +least the equal of the subtlety of those + + align:start position:0% +least the equal of the subtlety of those + + + align:start position:0% +least the equal of the subtlety of those +wonderful Shakespearean lines we're + + align:start position:0% +wonderful Shakespearean lines we're + + + align:start position:0% +wonderful Shakespearean lines we're +finished see you next time \ No newline at end of file diff --git a/2ieG1ka5pBw.txt b/2ieG1ka5pBw.txt new file mode 100644 index 0000000000000000000000000000000000000000..0e070f23c70dea44f0c72733eb54092892685cd6 --- /dev/null +++ b/2ieG1ka5pBw.txt @@ -0,0 +1,3115 @@ +align:start position:0% + +hi welcome back to recitation in lecture + + align:start position:0% +hi welcome back to recitation in lecture + + + align:start position:0% +hi welcome back to recitation in lecture +you've been learning about Stokes + + align:start position:0% +you've been learning about Stokes + + + align:start position:0% +you've been learning about Stokes +theorem and I have a nice question here + + align:start position:0% +theorem and I have a nice question here + + + align:start position:0% +theorem and I have a nice question here +for you that can put Stokes theorem to + + align:start position:0% +for you that can put Stokes theorem to + + + align:start position:0% +for you that can put Stokes theorem to +the test so what I'd like you to do is + + align:start position:0% +the test so what I'd like you to do is + + + align:start position:0% +the test so what I'd like you to do is +I'd like you to consider this field F so + + align:start position:0% +I'd like you to consider this field F so + + + align:start position:0% +I'd like you to consider this field F so +its components are 2z X and Y and the + + align:start position:0% +its components are 2z X and Y and the + + + align:start position:0% +its components are 2z X and Y and the +surface s that's the top half of the + + align:start position:0% +surface s that's the top half of the + + + align:start position:0% +surface s that's the top half of the +unit sphere so it's the sphere of radius + + align:start position:0% +unit sphere so it's the sphere of radius + + + align:start position:0% +unit sphere so it's the sphere of radius +one centered at the origin but only its + + align:start position:0% +one centered at the origin but only its + + + align:start position:0% +one centered at the origin but only its +top half only the part where Z is + + align:start position:0% +top half only the part where Z is + + + align:start position:0% +top half only the part where Z is +greater than or equal to zero so what + + align:start position:0% +greater than or equal to zero so what + + + align:start position:0% +greater than or equal to zero so what +I'd like you to do is to verify Stokes + + align:start position:0% +I'd like you to do is to verify Stokes + + + align:start position:0% +I'd like you to do is to verify Stokes +theorem for this surface so that is I'd + + align:start position:0% +theorem for this surface so that is I'd + + + align:start position:0% +theorem for this surface so that is I'd +like you to compute the surface integral + + align:start position:0% +like you to compute the surface integral + + + align:start position:0% +like you to compute the surface integral +that comes from Stokes theorem for this + + align:start position:0% +that comes from Stokes theorem for this + + + align:start position:0% +that comes from Stokes theorem for this +surface and the line integral that comes + + align:start position:0% +surface and the line integral that comes + + + align:start position:0% +surface and the line integral that comes +from Stokes theorem for this surface and + + align:start position:0% +from Stokes theorem for this surface and + + + align:start position:0% +from Stokes theorem for this surface and +check that they're really equal to each + + align:start position:0% +check that they're really equal to each + + + align:start position:0% +check that they're really equal to each +other now before we start we should just + + align:start position:0% +other now before we start we should just + + + align:start position:0% +other now before we start we should just +say one brief thing about compatible + + align:start position:0% +say one brief thing about compatible + + + align:start position:0% +say one brief thing about compatible +orientation so I didn't give you any + + align:start position:0% +orientation so I didn't give you any + + + align:start position:0% +orientation so I didn't give you any +orientations but of course it doesn't + + align:start position:0% +orientations but of course it doesn't + + + align:start position:0% +orientations but of course it doesn't +matter as long as you choose ones that + + align:start position:0% +matter as long as you choose ones that + + + align:start position:0% +matter as long as you choose ones that +are compatible so if you if you think + + align:start position:0% +are compatible so if you if you think + + + align:start position:0% +are compatible so if you if you think +about your rules that you have for + + align:start position:0% +about your rules that you have for + + + align:start position:0% +about your rules that you have for +finding them so if you imagine yourself + + align:start position:0% +finding them so if you imagine yourself + + + align:start position:0% +finding them so if you imagine yourself +walking along this boundary circle with + + align:start position:0% +walking along this boundary circle with + + + align:start position:0% +walking along this boundary circle with +your left hand out over that sphere so + + align:start position:0% +your left hand out over that sphere so + + + align:start position:0% +your left hand out over that sphere so +you'll be walking in this + + align:start position:0% +you'll be walking in this + + + align:start position:0% +you'll be walking in this +counterclockwise Direction when your + + align:start position:0% +counterclockwise Direction when your + + + align:start position:0% +counterclockwise Direction when your +head is sticking out of the sphere all + + align:start position:0% +head is sticking out of the sphere all + + + align:start position:0% +head is sticking out of the sphere all +right so in other words the outward + + align:start position:0% +right so in other words the outward + + + align:start position:0% +right so in other words the outward +orientation on the sphere is compatible + + align:start position:0% +orientation on the sphere is compatible + + + align:start position:0% +orientation on the sphere is compatible +with the counterclockwise orientation on + + align:start position:0% +with the counterclockwise orientation on + + + align:start position:0% +with the counterclockwise orientation on +the on the circle that is the that is + + align:start position:0% +the on the circle that is the that is + + + align:start position:0% +the on the circle that is the that is +the boundary so let's actually put in a + + align:start position:0% +the boundary so let's actually put in a + + + align:start position:0% +the boundary so let's actually put in a +little arrow here to just indicate + + align:start position:0% +little arrow here to just indicate + + + align:start position:0% +little arrow here to just indicate +that's our orientation for the circle + + align:start position:0% +that's our orientation for the circle + + + align:start position:0% +that's our orientation for the circle +and and our normal is an outward + + align:start position:0% +and and our normal is an outward + + + align:start position:0% +and and our normal is an outward +pointing normal and let's call our + + align:start position:0% +pointing normal and let's call our + + + align:start position:0% +pointing normal and let's call our +Circle C and our s is our sphere is our + + align:start position:0% +Circle C and our s is our sphere is our + + + align:start position:0% +Circle C and our s is our sphere is our +surface okay so just so we have the same + + align:start position:0% +surface okay so just so we have the same + + + align:start position:0% +surface okay so just so we have the same +notation um good so why don't you work + + align:start position:0% +notation um good so why don't you work + + + align:start position:0% +notation um good so why don't you work +this out compute the line integral + + align:start position:0% +this out compute the line integral + + + align:start position:0% +this out compute the line integral +compute the surface integral come back + + align:start position:0% +compute the surface integral come back + + + align:start position:0% +compute the surface integral come back +and we can work them out together + + align:start position:0% + + + + align:start position:0% + +hopefully you had some luck working on + + align:start position:0% +hopefully you had some luck working on + + + align:start position:0% +hopefully you had some luck working on +this problem we have two things to + + align:start position:0% +this problem we have two things to + + + align:start position:0% +this problem we have two things to +compute I think I'm going to start with + + align:start position:0% +compute I think I'm going to start with + + + align:start position:0% +compute I think I'm going to start with +the with the line integral so to compute + + align:start position:0% +the with the line integral so to compute + + + align:start position:0% +the with the line integral so to compute +the line so let me write that down line + + align:start position:0% + + + + align:start position:0% + +integral so what I need to do to compute + + align:start position:0% +integral so what I need to do to compute + + + align:start position:0% +integral so what I need to do to compute +the line integral is I need to compute + + align:start position:0% +the line integral is I need to compute + + + align:start position:0% +the line integral is I need to compute +so I want the + + align:start position:0% +so I want the + + + align:start position:0% +so I want the +integral over the curve + + align:start position:0% +integral over the curve + + + align:start position:0% +integral over the curve +C of f do + + align:start position:0% +C of f do + + + align:start position:0% +C of f do +Dr and so I know what f is on the on + + align:start position:0% +Dr and so I know what f is on the on + + + align:start position:0% +Dr and so I know what f is on the on +that Circle so I need to know what Dr is + + align:start position:0% +that Circle so I need to know what Dr is + + + align:start position:0% +that Circle so I need to know what Dr is +I so I need to know what R is I need a + + align:start position:0% +I so I need to know what R is I need a + + + align:start position:0% +I so I need to know what R is I need a +parameterization of that Circle well you + + align:start position:0% +parameterization of that Circle well you + + + align:start position:0% +parameterization of that Circle well you +know that's a pretty easy Circle to + + align:start position:0% +know that's a pretty easy Circle to + + + align:start position:0% +know that's a pretty easy Circle to +parameterize it's the unit circle in the + + align:start position:0% +parameterize it's the unit circle in the + + + align:start position:0% +parameterize it's the unit circle in the +XY plane so we have for C we have and + + align:start position:0% +XY plane so we have for C we have and + + + align:start position:0% +XY plane so we have for C we have and +it's and we're and we're wandering + + align:start position:0% +it's and we're and we're wandering + + + align:start position:0% +it's and we're and we're wandering +around it counterclockwise so it's it's + + align:start position:0% +around it counterclockwise so it's it's + + + align:start position:0% +around it counterclockwise so it's it's +our usual parameterization it's the one + + align:start position:0% +our usual parameterization it's the one + + + align:start position:0% +our usual parameterization it's the one +we like so we have x = cosine + + align:start position:0% +we like so we have x = cosine + + + align:start position:0% +we like so we have x = cosine +t y = sin t z where T goes from + + align:start position:0% +t y = sin t z where T goes from + + + align:start position:0% +t y = sin t z where T goes from +zero to 2 pi oh and this is in three + + align:start position:0% +zero to 2 pi oh and this is in three + + + align:start position:0% +zero to 2 pi oh and this is in three +dimensions so the other part of the + + align:start position:0% +dimensions so the other part of the + + + align:start position:0% +dimensions so the other part of the +parameterization is z equals z so this + + align:start position:0% +parameterization is z equals z so this + + + align:start position:0% +parameterization is z equals z so this +is my parameterization of this of this + + align:start position:0% +is my parameterization of this of this + + + align:start position:0% +is my parameterization of this of this +circle um okay so so let's go ahead and + + align:start position:0% +circle um okay so so let's go ahead and + + + align:start position:0% +circle um okay so so let's go ahead and +put that in so + + align:start position:0% +put that in so + + + align:start position:0% +put that in so +so the integral over + + align:start position:0% +so the integral over + + + align:start position:0% +so the integral over +C of f + + align:start position:0% +C of f + + + align:start position:0% +C of f +dot + + align:start position:0% +dot + + + align:start position:0% +dot +Dr well so it's the integral from 0 to 2 + + align:start position:0% +Dr well so it's the integral from 0 to 2 + + + align:start position:0% +Dr well so it's the integral from 0 to 2 +pi so we've got three parts so the first + + align:start position:0% +pi so we've got three parts so the first + + + align:start position:0% +pi so we've got three parts so the first +part so f is going to be we have to go + + align:start position:0% +part so f is going to be we have to go + + + align:start position:0% +part so f is going to be we have to go +let's see so it's 2 Z XY so it's 2z DX + + align:start position:0% +let's see so it's 2 Z XY so it's 2z DX + + + align:start position:0% +let's see so it's 2 Z XY so it's 2z DX +plus X Dy + y DZ but Z is zero on this + + align:start position:0% +plus X Dy + y DZ but Z is zero on this + + + align:start position:0% +plus X Dy + y DZ but Z is zero on this +whole circle so so that piece just dies + + align:start position:0% +whole circle so so that piece just dies + + + align:start position:0% +whole circle so so that piece just dies +and DZ is also zero so that piece just + + align:start position:0% +and DZ is also zero so that piece just + + + align:start position:0% +and DZ is also zero so that piece just +dies so we're just left with xdy so this + + align:start position:0% +dies so we're just left with xdy so this + + + align:start position:0% +dies so we're just left with xdy so this +is equal to the integral of + + align:start position:0% +is equal to the integral of + + + align:start position:0% +is equal to the integral of +x Dy oh so I guess this is not from 0 to + + align:start position:0% +x Dy oh so I guess this is not from 0 to + + + align:start position:0% +x Dy oh so I guess this is not from 0 to +2 pi this is still over C sorry about + + align:start position:0% +2 pi this is still over C sorry about + + + align:start position:0% +2 pi this is still over C sorry about +that okay and now when I + + align:start position:0% +that okay and now when I + + + align:start position:0% +that okay and now when I +change to + + align:start position:0% +change to + + + align:start position:0% +change to +my parameterization okay yes right so + + align:start position:0% +my parameterization okay yes right so + + + align:start position:0% +my parameterization okay yes right so +we're this is still in DX Dy d form so + + align:start position:0% +we're this is still in DX Dy d form so + + + align:start position:0% +we're this is still in DX Dy d form so +it's it's still over C now we switch to + + align:start position:0% +it's it's still over C now we switch to + + + align:start position:0% +it's it's still over C now we switch to +the DT form so now T is going from 0 to + + align:start position:0% +the DT form so now T is going from 0 to + + + align:start position:0% +the DT form so now T is going from 0 to +2 pi okay so now we have xdy so X is + + align:start position:0% +2 pi okay so now we have xdy so X is + + + align:start position:0% +2 pi okay so now we have xdy so X is +cosine T and Dy so Y is sin T So Dy is + + align:start position:0% +cosine T and Dy so Y is sin T So Dy is + + + align:start position:0% +cosine T and Dy so Y is sin T So Dy is +cosine T DT so this is cosine T * cosine + + align:start position:0% +cosine T DT so this is cosine T * cosine + + + align:start position:0% +cosine T DT so this is cosine T * cosine +T is cosine 2qu + + align:start position:0% +T is cosine 2qu + + + align:start position:0% +T is cosine 2qu +T DT gosh so now you have to remember + + align:start position:0% +T DT gosh so now you have to remember + + + align:start position:0% +T DT gosh so now you have to remember +way back in 1801 when you learned how to + + align:start position:0% +way back in 1801 when you learned how to + + + align:start position:0% +way back in 1801 when you learned how to +compute trig integrals like this so I + + align:start position:0% +compute trig integrals like this so I + + + align:start position:0% +compute trig integrals like this so I +think the thing that we do when we have + + align:start position:0% +think the thing that we do when we have + + + align:start position:0% +think the thing that we do when we have +a cosine Square t is we use a half angle + + align:start position:0% +a cosine Square t is we use a half angle + + + align:start position:0% +a cosine Square t is we use a half angle +formula so let me come back down here + + align:start position:0% +formula so let me come back down here + + + align:start position:0% +formula so let me come back down here +just to finish this off in one board + + align:start position:0% +just to finish this off in one board + + + align:start position:0% +just to finish this off in one board +okay so cosine squ T so that's the + + align:start position:0% +okay so cosine squ T so that's the + + + align:start position:0% +okay so cosine squ T so that's the +integral from 0 to 2 pi so cosine 2qu T + + align:start position:0% +integral from 0 to 2 pi so cosine 2qu T + + + align:start position:0% +integral from 0 to 2 pi so cosine 2qu T +is 1 + cosine 2T / + + align:start position:0% +is 1 + cosine 2T / + + + align:start position:0% +is 1 + cosine 2T / +2 DT and now cosine 2T as T goes between + + align:start position:0% +2 DT and now cosine 2T as T goes between + + + align:start position:0% +2 DT and now cosine 2T as T goes between +0 and 2 pi well that's two whole Loops + + align:start position:0% +0 and 2 pi well that's two whole Loops + + + align:start position:0% +0 and 2 pi well that's two whole Loops +of it right two whole periods of Co 2T + + align:start position:0% +of it right two whole periods of Co 2T + + + align:start position:0% +of it right two whole periods of Co 2T +and you know it's a trig function it's a + + align:start position:0% +and you know it's a trig function it's a + + + align:start position:0% +and you know it's a trig function it's a +nice cosine function so the positive + + align:start position:0% +nice cosine function so the positive + + + align:start position:0% +nice cosine function so the positive +parts and the negative Parts cancel so + + align:start position:0% +parts and the negative Parts cancel so + + + align:start position:0% +parts and the negative Parts cancel so +the cosine 2T part when we integrate it + + align:start position:0% +the cosine 2T part when we integrate it + + + align:start position:0% +the cosine 2T part when we integrate it +from 0 to 2 pi that gives us zero so + + align:start position:0% +from 0 to 2 pi that gives us zero so + + + align:start position:0% +from 0 to 2 pi that gives us zero so +we're left with 1 + + align:start position:0% +we're left with 1 + + + align:start position:0% +we're left with 1 +12 integrated from 0 to 2 pi and that's + + align:start position:0% +12 integrated from 0 to 2 pi and that's + + + align:start position:0% +12 integrated from 0 to 2 pi and that's +just going to give us 1 12 of 2 pi so + + align:start position:0% +just going to give us 1 12 of 2 pi so + + + align:start position:0% +just going to give us 1 12 of 2 pi so +that's Pi all right so good so that was + + align:start position:0% +that's Pi all right so good so that was + + + align:start position:0% +that's Pi all right so good so that was +the line integral very straightforward + + align:start position:0% +the line integral very straightforward + + + align:start position:0% +the line integral very straightforward +thing we had our Circle back here we had + + align:start position:0% +thing we had our Circle back here we had + + + align:start position:0% +thing we had our Circle back here we had +our Circle we had our field so we + + align:start position:0% +our Circle we had our field so we + + + align:start position:0% +our Circle we had our field so we +parameterized the curve that is the + + align:start position:0% +parameterized the curve that is the + + + align:start position:0% +parameterized the curve that is the +circle that is the boundary and then we + + align:start position:0% +circle that is the boundary and then we + + + align:start position:0% +circle that is the boundary and then we +just computed the line integral and it + + align:start position:0% +just computed the line integral and it + + + align:start position:0% +just computed the line integral and it +was a nice easy one to do you had to + + align:start position:0% +was a nice easy one to do you had to + + + align:start position:0% +was a nice easy one to do you had to +remember one little trig identity in + + align:start position:0% +remember one little trig identity in + + + align:start position:0% +remember one little trig identity in +order to do it all right that's the + + align:start position:0% +order to do it all right that's the + + + align:start position:0% +order to do it all right that's the +first one so let's + + align:start position:0% +first one so let's + + + align:start position:0% +first one so let's +uh let's go on to the surface + + align:start position:0% + + + + align:start position:0% + +integral so the surface integral that + + align:start position:0% +integral so the surface integral that + + + align:start position:0% +integral so the surface integral that +you have to compute in Stokes theorem is + + align:start position:0% +you have to compute in Stokes theorem is + + + align:start position:0% +you have to compute in Stokes theorem is +you have to compute the double + + align:start position:0% +you have to compute the double + + + align:start position:0% +you have to compute the double +integral over your + + align:start position:0% +integral over your + + + align:start position:0% +integral over your +surface of the curl of + + align:start position:0% +surface of the curl of + + + align:start position:0% +surface of the curl of +f + + align:start position:0% +f + + + align:start position:0% +f +dotn with respect to surface area so + + align:start position:0% +dotn with respect to surface area so + + + align:start position:0% +dotn with respect to surface area so +this is the this is the integral we want + + align:start position:0% +this is the this is the integral we want + + + align:start position:0% +this is the this is the integral we want +to compute here this so okay so first + + align:start position:0% +to compute here this so okay so first + + + align:start position:0% +to compute here this so okay so first +thing we're going to need we're going to + + align:start position:0% +thing we're going to need we're going to + + + align:start position:0% +thing we're going to need we're going to +we're going to need to find the curl of + + align:start position:0% +we're going to need to find the curl of + + + align:start position:0% +we're going to need to find the curl of +F Well let's see so F let's let me just + + align:start position:0% +F Well let's see so F let's let me just + + + align:start position:0% +F Well let's see so F let's let me just +write it here so we don't have to walk + + align:start position:0% +write it here so we don't have to walk + + + align:start position:0% +write it here so we don't have to walk +all the way back over there so f is what + + align:start position:0% +all the way back over there so f is what + + + align:start position:0% +all the way back over there so f is what +is it it's + + align:start position:0% +is it it's + + + align:start position:0% +is it it's +2z + + align:start position:0% +2z + + + align:start position:0% +2z +X Y so curl of f okay you should have + + align:start position:0% +X Y so curl of f okay you should have + + + align:start position:0% +X Y so curl of f okay you should have +lots of experience Computing Curls by + + align:start position:0% +lots of experience Computing Curls by + + + align:start position:0% +lots of experience Computing Curls by +now but let's see okay so it's going to + + align:start position:0% +now but let's see okay so it's going to + + + align:start position:0% +now but let's see okay so it's going to +be this I I always think of it so we've + + align:start position:0% +be this I I always think of it so we've + + + align:start position:0% +be this I I always think of it so we've +got these little 2 by two determinants + + align:start position:0% +got these little 2 by two determinants + + + align:start position:0% +got these little 2 by two determinants +with the partial derivatives in them but + + align:start position:0% +with the partial derivatives in them but + + + align:start position:0% +with the partial derivatives in them but +most of those are going to be zero we've + + align:start position:0% +most of those are going to be zero we've + + + align:start position:0% +most of those are going to be zero we've +got a dxx term that's coming up in k and + + align:start position:0% +got a dxx term that's coming up in k and + + + align:start position:0% +got a dxx term that's coming up in k and +a Dy y term that's coming up in I and a + + align:start position:0% +a Dy y term that's coming up in I and a + + + align:start position:0% +a Dy y term that's coming up in I and a +DZ 2z term term that's coming up in in J + + align:start position:0% +DZ 2z term term that's coming up in in J + + + align:start position:0% +DZ 2z term term that's coming up in in J +so okay so almost all half the terms are + + align:start position:0% +so okay so almost all half the terms are + + + align:start position:0% +so okay so almost all half the terms are +zero the others are really easy to + + align:start position:0% +zero the others are really easy to + + + align:start position:0% +zero the others are really easy to +compute I trust that you can also + + align:start position:0% +compute I trust that you can also + + + align:start position:0% +compute I trust that you can also +compute and get that the curl is one 12 + + align:start position:0% +compute and get that the curl is one 12 + + + align:start position:0% +compute and get that the curl is one 12 +one here okay so this is F this is curl + + align:start position:0% +one here okay so this is F this is curl + + + align:start position:0% +one here okay so this is F this is curl +of f great so okay so that's curl of f + + align:start position:0% +of f great so okay so that's curl of f + + + align:start position:0% +of f great so okay so that's curl of f +so now we need + + align:start position:0% +so now we need + + + align:start position:0% +so now we need +n well let's think so we need we need + + align:start position:0% +n well let's think so we need we need + + + align:start position:0% +n well let's think so we need we need +the unit normal to our surface and we + + align:start position:0% +the unit normal to our surface and we + + + align:start position:0% +the unit normal to our surface and we +said all right so back at the beginning + + align:start position:0% +said all right so back at the beginning + + + align:start position:0% +said all right so back at the beginning +before before we started we said it was + + align:start position:0% +before before we started we said it was + + + align:start position:0% +before before we started we said it was +the outward point normal so we need the + + align:start position:0% +the outward point normal so we need the + + + align:start position:0% +the outward point normal so we need the +outward pointing normal well this is a + + align:start position:0% +outward pointing normal well this is a + + + align:start position:0% +outward pointing normal well this is a +sphere right so so the normal is + + align:start position:0% +sphere right so so the normal is + + + align:start position:0% +sphere right so so the normal is +parallel to the position Vector so that + + align:start position:0% +parallel to the position Vector so that + + + align:start position:0% +parallel to the position Vector so that +means n should be parallel + + align:start position:0% +means n should be parallel + + + align:start position:0% +means n should be parallel +to should be parallel to the vector XYZ + + align:start position:0% +to should be parallel to the vector XYZ + + + align:start position:0% +to should be parallel to the vector XYZ +the position Vector so n should be + + align:start position:0% +the position Vector so n should be + + + align:start position:0% +the position Vector so n should be +parallel to this Vector XYZ but in fact + + align:start position:0% +parallel to this Vector XYZ but in fact + + + align:start position:0% +parallel to this Vector XYZ but in fact +it we're even better than that we're on + + align:start position:0% +it we're even better than that we're on + + + align:start position:0% +it we're even better than that we're on +a unit sphere so the the position Vector + + align:start position:0% +a unit sphere so the the position Vector + + + align:start position:0% +a unit sphere so the the position Vector +has length one so n should be pointing + + align:start position:0% +has length one so n should be pointing + + + align:start position:0% +has length one so n should be pointing +in the same direction is this vector and + + align:start position:0% +in the same direction is this vector and + + + align:start position:0% +in the same direction is this vector and +they both have length one so they better + + align:start position:0% +they both have length one so they better + + + align:start position:0% +they both have length one so they better +be equal to each + + align:start position:0% +be equal to each + + + align:start position:0% +be equal to each +other great so so this unit normal n is + + align:start position:0% +other great so so this unit normal n is + + + align:start position:0% +other great so so this unit normal n is +is just this very simple Vector XYZ you + + align:start position:0% +is just this very simple Vector XYZ you + + + align:start position:0% +is just this very simple Vector XYZ you +know if it had been a bigger sphere then + + align:start position:0% +know if it had been a bigger sphere then + + + align:start position:0% +know if it had been a bigger sphere then +you might have to you would have to + + align:start position:0% +you might have to you would have to + + + align:start position:0% +you might have to you would have to +divide this by by the radius to scale it + + align:start position:0% + + + + align:start position:0% + +appropriately all right so we've got + + align:start position:0% +appropriately all right so we've got + + + align:start position:0% +appropriately all right so we've got +curl F we've got n so the thing that we + + align:start position:0% +curl F we've got n so the thing that we + + + align:start position:0% +curl F we've got n so the thing that we +want okay so the integral that we + + align:start position:0% +want okay so the integral that we + + + align:start position:0% +want okay so the integral that we +want is + + align:start position:0% +want is + + + align:start position:0% +want is +this double + + align:start position:0% +this double + + + align:start position:0% +this double +integral over the surface okay of curl + + align:start position:0% +integral over the surface okay of curl + + + align:start position:0% +integral over the surface okay of curl +f.n so that's x + 2 y + + + align:start position:0% +f.n so that's x + 2 y + + + + align:start position:0% +f.n so that's x + 2 y + +z with respect to surface + + align:start position:0% +z with respect to surface + + + align:start position:0% +z with respect to surface +area okay well now we've just got a + + align:start position:0% +area okay well now we've just got a + + + align:start position:0% +area okay well now we've just got a +surface integral it's over a sphere not + + align:start position:0% +surface integral it's over a sphere not + + + align:start position:0% +surface integral it's over a sphere not +a Terri well a hemisphere not a terrible + + align:start position:0% +a Terri well a hemisphere not a terrible + + + align:start position:0% +a Terri well a hemisphere not a terrible +thing to parameterize so okay so that's + + align:start position:0% +thing to parameterize so okay so that's + + + align:start position:0% +thing to parameterize so okay so that's +what we should do we should go in we + + align:start position:0% +what we should do we should go in we + + + align:start position:0% +what we should do we should go in we +should parameterize it and then we + + align:start position:0% +should parameterize it and then we + + + align:start position:0% +should parameterize it and then we +should you know just compute it like a + + align:start position:0% +should you know just compute it like a + + + align:start position:0% +should you know just compute it like a +surface integral like we like we know + + align:start position:0% +surface integral like we like we know + + + align:start position:0% +surface integral like we like we know +how to do so um before we start though I + + align:start position:0% +how to do so um before we start though I + + + align:start position:0% +how to do so um before we start though I +want to make one little observation well + + align:start position:0% +want to make one little observation well + + + align:start position:0% +want to make one little observation well +maybe two little observations so we can + + align:start position:0% +maybe two little observations so we can + + + align:start position:0% +maybe two little observations so we can +simplify this all right + + align:start position:0% +simplify this all right + + + align:start position:0% +simplify this all right +X we're integrating X over the surface + + align:start position:0% +X we're integrating X over the surface + + + align:start position:0% +X we're integrating X over the surface +of a hemisphere centered at the origin + + align:start position:0% +of a hemisphere centered at the origin + + + align:start position:0% +of a hemisphere centered at the origin +this hemisphere is really symmetric and + + align:start position:0% +this hemisphere is really symmetric and + + + align:start position:0% +this hemisphere is really symmetric and +on the Nega the back side the part where + + align:start position:0% +on the Nega the back side the part where + + + align:start position:0% +on the Nega the back side the part where +X is negative we're getting negative + + align:start position:0% +X is negative we're getting negative + + + align:start position:0% +X is negative we're getting negative +contributions from X and on the front + + align:start position:0% +contributions from X and on the front + + + align:start position:0% +contributions from X and on the front +side where X is positive we're getting + + align:start position:0% +side where X is positive we're getting + + + align:start position:0% +side where X is positive we're getting +positive contributions from X and + + align:start position:0% +positive contributions from X and + + + align:start position:0% +positive contributions from X and +because this sphere is totally symmetric + + align:start position:0% +because this sphere is totally symmetric + + + align:start position:0% +because this sphere is totally symmetric +those just cancel out + + align:start position:0% +those just cancel out + + + align:start position:0% +those just cancel out +completely so when we integrate x over + + align:start position:0% +completely so when we integrate x over + + + align:start position:0% +completely so when we integrate x over +the whole + + align:start position:0% +the whole + + + align:start position:0% +the whole +sphere over the whole + + align:start position:0% +sphere over the whole + + + align:start position:0% +sphere over the whole +hemisphere it just it just kills itself + + align:start position:0% +hemisphere it just it just kills itself + + + align:start position:0% +hemisphere it just it just kills itself +I mean the negative Parts kill the + + align:start position:0% +I mean the negative Parts kill the + + + align:start position:0% +I mean the negative Parts kill the +positive parts we just get zero + + align:start position:0% +positive parts we just get zero + + + align:start position:0% +positive parts we just get zero +similarly this hemisphere is symmetric + + align:start position:0% +similarly this hemisphere is symmetric + + + align:start position:0% +similarly this hemisphere is symmetric +between its left side and its right side + + align:start position:0% +between its left side and its right side + + + align:start position:0% +between its left side and its right side +and so the parts where y are negative + + align:start position:0% +and so the parts where y are negative + + + align:start position:0% +and so the parts where y are negative +cancel out exactly where the parts where + + align:start position:0% +cancel out exactly where the parts where + + + align:start position:0% +cancel out exactly where the parts where +y are positive so a simplifying step we + + align:start position:0% +y are positive so a simplifying step we + + + align:start position:0% +y are positive so a simplifying step we +can realize right at the beginning that + + align:start position:0% +can realize right at the beginning that + + + align:start position:0% +can realize right at the beginning that +this is actually just the integral over + + align:start position:0% +this is actually just the integral over + + + align:start position:0% +this is actually just the integral over +s of + + align:start position:0% +s of + + + align:start position:0% +s of +Z with respect to surface area now if + + align:start position:0% +Z with respect to surface area now if + + + align:start position:0% +Z with respect to surface area now if +you didn't realize that that's okay what + + align:start position:0% +you didn't realize that that's okay what + + + align:start position:0% +you didn't realize that that's okay what +you would have done is you would have + + align:start position:0% +you would have done is you would have + + + align:start position:0% +you would have done is you would have +done the parameterization that we're + + align:start position:0% +done the parameterization that we're + + + align:start position:0% +done the parameterization that we're +about to do and in doing that + + align:start position:0% +about to do and in doing that + + + align:start position:0% +about to do and in doing that +parameterization you would have found + + align:start position:0% +parameterization you would have found + + + align:start position:0% +parameterization you would have found +that you were integrating something like + + align:start position:0% +that you were integrating something like + + + align:start position:0% +that you were integrating something like +cosine Theta between 0 and 2 pi or + + align:start position:0% +cosine Theta between 0 and 2 pi or + + + align:start position:0% +cosine Theta between 0 and 2 pi or +something like this and that would have + + align:start position:0% +something like this and that would have + + + align:start position:0% +something like this and that would have +given you zero so you would have you + + align:start position:0% +given you zero so you would have you + + + align:start position:0% +given you zero so you would have you +would have found this simp + + align:start position:0% +would have found this simp + + + align:start position:0% +would have found this simp +syry even if you didn't realize it right + + align:start position:0% +syry even if you didn't realize it right + + + align:start position:0% +syry even if you didn't realize it right +now you would have found it in the + + align:start position:0% +now you would have found it in the + + + align:start position:0% +now you would have found it in the +process of computing this this integral + + align:start position:0% +process of computing this this integral + + + align:start position:0% +process of computing this this integral +but but it's a little bit easier on us + + align:start position:0% +but but it's a little bit easier on us + + + align:start position:0% +but but it's a little bit easier on us +if we if we sort of can recognize that + + align:start position:0% +if we if we sort of can recognize that + + + align:start position:0% +if we if we sort of can recognize that +symmetry first now notice that Z doesn't + + align:start position:0% +symmetry first now notice that Z doesn't + + + align:start position:0% +symmetry first now notice that Z doesn't +cancel because this is just the top + + align:start position:0% +cancel because this is just the top + + + align:start position:0% +cancel because this is just the top +hemisphere so it doesn't have a bottom + + align:start position:0% +hemisphere so it doesn't have a bottom + + + align:start position:0% +hemisphere so it doesn't have a bottom +half to cancel out with right so the Z + + align:start position:0% +half to cancel out with right so the Z + + + align:start position:0% +half to cancel out with right so the Z +part we can't use this this easy + + align:start position:0% +part we can't use this this easy + + + align:start position:0% +part we can't use this this easy +analysis on if we were if we integrated + + align:start position:0% +analysis on if we were if we integrated + + + align:start position:0% +analysis on if we were if we integrated +this Z over the whole sphere if we had + + align:start position:0% +this Z over the whole sphere if we had + + + align:start position:0% +this Z over the whole sphere if we had +the other half of the sphere well then + + align:start position:0% +the other half of the sphere well then + + + align:start position:0% +the other half of the sphere well then +that would also give us zero but but we + + align:start position:0% +that would also give us zero but but we + + + align:start position:0% +that would also give us zero but but we +only have the half of the sphere the top + + align:start position:0% +only have the half of the sphere the top + + + align:start position:0% +only have the half of the sphere the top +half of the sphere so it's going to give + + align:start position:0% +half of the sphere so it's going to give + + + align:start position:0% +half of the sphere so it's going to give +us something positive because Z is + + align:start position:0% +us something positive because Z is + + + align:start position:0% +us something positive because Z is +always positive up there okay so let's + + align:start position:0% +always positive up there okay so let's + + + align:start position:0% +always positive up there okay so let's +let's actually set about parameterizing + + align:start position:0% +let's actually set about parameterizing + + + align:start position:0% +let's actually set about parameterizing +it we want to parameterize the unit + + align:start position:0% +it we want to parameterize the unit + + + align:start position:0% +it we want to parameterize the unit +sphere well okay so we have our standard + + align:start position:0% +sphere well okay so we have our standard + + + align:start position:0% +sphere well okay so we have our standard +parameterization that comes from + + align:start position:0% +parameterization that comes from + + + align:start position:0% +parameterization that comes from +spherical coordinates so row is just one + + align:start position:0% +spherical coordinates so row is just one + + + align:start position:0% +spherical coordinates so row is just one +right so + + align:start position:0% +right so + + + align:start position:0% +right so +X is equal to it's going to + + align:start position:0% +X is equal to it's going to + + + align:start position:0% +X is equal to it's going to +be cosine you know what I always get a + + align:start position:0% +be cosine you know what I always get a + + + align:start position:0% +be cosine you know what I always get a +little confused so I'm just going to + + align:start position:0% +little confused so I'm just going to + + + align:start position:0% +little confused so I'm just going to +check carefully that I'm doing doing + + align:start position:0% +check carefully that I'm doing doing + + + align:start position:0% +check carefully that I'm doing doing +this perfectly right X is going to be + + align:start position:0% +this perfectly right X is going to be + + + align:start position:0% +this perfectly right X is going to be +yes cosine Theta sin V good Y is going + + align:start position:0% +yes cosine Theta sin V good Y is going + + + align:start position:0% +yes cosine Theta sin V good Y is going +to be sin + + align:start position:0% +to be sin + + + align:start position:0% +to be sin +Theta sinine V and + + align:start position:0% +Theta sinine V and + + + align:start position:0% +Theta sinine V and +Z is going to be + + align:start position:0% +Z is going to be + + + align:start position:0% +Z is going to be +cosine Fe so that's our parameterization + + align:start position:0% +cosine Fe so that's our parameterization + + + align:start position:0% +cosine Fe so that's our parameterization +okay but this this we need bounds of + + align:start position:0% +okay but this this we need bounds of + + + align:start position:0% +okay but this this we need bounds of +course on Theta and v in order to + + align:start position:0% +course on Theta and v in order to + + + align:start position:0% +course on Theta and v in order to +properly describe just this hemisphere + + align:start position:0% +properly describe just this hemisphere + + + align:start position:0% +properly describe just this hemisphere +so let's think so Fe we want the + + align:start position:0% +so let's think so Fe we want the + + + align:start position:0% +so let's think so Fe we want the +hemisphere that goes from the Z axis + + align:start position:0% +hemisphere that goes from the Z axis + + + align:start position:0% +hemisphere that goes from the Z axis +down to the XY plane so that means we + + align:start position:0% +down to the XY plane so that means we + + + align:start position:0% +down to the XY plane so that means we +want + + align:start position:0% +want + + + align:start position:0% +want +0o to be less than or equal to F to be + + align:start position:0% +0o to be less than or equal to F to be + + + align:start position:0% +0o to be less than or equal to F to be +less than or equal to Pi / 2 right + + align:start position:0% +less than or equal to Pi / 2 right + + + align:start position:0% +less than or equal to Pi / 2 right +that'll give us that just that top half + + align:start position:0% +that'll give us that just that top half + + + align:start position:0% +that'll give us that just that top half +and we want the whole thing we want to + + align:start position:0% +and we want the whole thing we want to + + + align:start position:0% +and we want the whole thing we want to +go all the way around so we want zero + + align:start position:0% +go all the way around so we want zero + + + align:start position:0% +go all the way around so we want zero +less than or equal to Theta less than or + + align:start position:0% +less than or equal to Theta less than or + + + align:start position:0% +less than or equal to Theta less than or +equal to 2 + + align:start position:0% +equal to 2 + + + align:start position:0% +equal to 2 +pi so this is okay so this is our what x + + align:start position:0% +pi so this is okay so this is our what x + + + align:start position:0% +pi so this is okay so this is our what x +y and z are these are the bounds for our + + align:start position:0% +y and z are these are the bounds for our + + + align:start position:0% +y and z are these are the bounds for our +parameters the and Theta um now the only + + align:start position:0% +parameters the and Theta um now the only + + + align:start position:0% +parameters the and Theta um now the only +other thing we need is we need to know + + align:start position:0% +other thing we need is we need to know + + + align:start position:0% +other thing we need is we need to know +what DS is so in spherical coordinates + + align:start position:0% +what DS is so in spherical coordinates + + + align:start position:0% +what DS is so in spherical coordinates +we know that + + align:start position:0% +we know that + + + align:start position:0% +we know that +DS I'll put it right above here so DS is + + align:start position:0% +DS I'll put it right above here so DS is + + + align:start position:0% +DS I'll put it right above here so DS is +equal + + align:start position:0% +equal + + + align:start position:0% +equal +to sin + + align:start position:0% +to sin + + + align:start position:0% +to sin +v d Fe D Theta let me again just double + + align:start position:0% +v d Fe D Theta let me again just double + + + align:start position:0% +v d Fe D Theta let me again just double +check that that I'm not doing anything + + align:start position:0% +check that that I'm not doing anything + + + align:start position:0% +check that that I'm not doing anything +silly so DS is equal to sin v d v d + + align:start position:0% +silly so DS is equal to sin v d v d + + + align:start position:0% +silly so DS is equal to sin v d v d +Theta so we've got our parameterization + + align:start position:0% +Theta so we've got our parameterization + + + align:start position:0% +Theta so we've got our parameterization +we've got our bounds on our parameters + + align:start position:0% +we've got our bounds on our parameters + + + align:start position:0% +we've got our bounds on our parameters +we know what DS is and we have the + + align:start position:0% +we know what DS is and we have the + + + align:start position:0% +we know what DS is and we have the +integral that we want to compute so now + + align:start position:0% +integral that we want to compute so now + + + align:start position:0% +integral that we want to compute so now +we just have to substitute everything in + + align:start position:0% +we just have to substitute everything in + + + align:start position:0% +we just have to substitute everything in +and actually compute it as an iterated + + align:start position:0% +and actually compute it as an iterated + + + align:start position:0% +and actually compute it as an iterated +integral great so let's do that so this + + align:start position:0% +integral great so let's do that so this + + + align:start position:0% +integral great so let's do that so this +integral that we want I'm going to write + + align:start position:0% +integral that we want I'm going to write + + + align:start position:0% +integral that we want I'm going to write +a big equal sign that's going to carry + + align:start position:0% +a big equal sign that's going to carry + + + align:start position:0% +a big equal sign that's going to carry +me all the way up here + + align:start position:0% +me all the way up here + + + align:start position:0% +me all the way up here +that's an equal sign all right so our + + align:start position:0% +that's an equal sign all right so our + + + align:start position:0% +that's an equal sign all right so our +integral the integral over s of Z with + + align:start position:0% +integral the integral over s of Z with + + + align:start position:0% +integral the integral over s of Z with +respect to surface area so Z becomes + + align:start position:0% +respect to surface area so Z becomes + + + align:start position:0% +respect to surface area so Z becomes +cosine V so we've got our double + + align:start position:0% +cosine V so we've got our double + + + align:start position:0% +cosine V so we've got our double +integral becomes an iterated integral Z + + align:start position:0% +integral becomes an iterated integral Z + + + align:start position:0% +integral becomes an iterated integral Z +becomes cosine V DS becomes sin Fe d f d + + align:start position:0% +becomes cosine V DS becomes sin Fe d f d + + + align:start position:0% +becomes cosine V DS becomes sin Fe d f d +Theta sin + + align:start position:0% +Theta sin + + + align:start position:0% +Theta sin +v d + + align:start position:0% +v d + + + align:start position:0% +v d +v d Theta and our bound so let's see V + + align:start position:0% +v d Theta and our bound so let's see V + + + align:start position:0% +v d Theta and our bound so let's see V +we said is going from 0 to Pi / 2 0 to + + align:start position:0% +we said is going from 0 to Pi / 2 0 to + + + align:start position:0% +we said is going from 0 to Pi / 2 0 to +Pi / 2 and Theta is going from 0 to 2 + + align:start position:0% +Pi / 2 and Theta is going from 0 to 2 + + + align:start position:0% +Pi / 2 and Theta is going from 0 to 2 +pi okay so now we just have a nice + + align:start position:0% +pi okay so now we just have a nice + + + align:start position:0% +pi okay so now we just have a nice +straightforward iterated integral here + + align:start position:0% +straightforward iterated integral here + + + align:start position:0% +straightforward iterated integral here +to compute so let's do the inner one + + align:start position:0% +to compute so let's do the inner one + + + align:start position:0% +to compute so let's do the inner one +first so we're + + align:start position:0% +first so we're + + + align:start position:0% +first so we're +Computing the inner integral is the + + align:start position:0% +Computing the inner integral is the + + + align:start position:0% +Computing the inner integral is the +integral from + + align:start position:0% +integral from + + + align:start position:0% +integral from +0 to Pi / 2 of cosine + + align:start position:0% +0 to Pi / 2 of cosine + + + align:start position:0% +0 to Pi / 2 of cosine +F sin + + align:start position:0% +F sin + + + align:start position:0% +F sin +f d Fe and okay so this is you know + + align:start position:0% +f d Fe and okay so this is you know + + + align:start position:0% +f d Fe and okay so this is you know +bunch of different ways you could do + + align:start position:0% +bunch of different ways you could do + + + align:start position:0% +bunch of different ways you could do +this if you wanted to get fancy you + + align:start position:0% +this if you wanted to get fancy you + + + align:start position:0% +this if you wanted to get fancy you +could do a double angle formula here but + + align:start position:0% +could do a double angle formula here but + + + align:start position:0% +could do a double angle formula here but +that's really more fancy than you need + + align:start position:0% +that's really more fancy than you need + + + align:start position:0% +that's really more fancy than you need +because this is like sinine Fe time D + + align:start position:0% +because this is like sinine Fe time D + + + align:start position:0% +because this is like sinine Fe time D +sin Fe right so this is equal to you + + align:start position:0% +sin Fe right so this is equal to you + + + align:start position:0% +sin Fe right so this is equal to you +know you could another way of saying + + align:start position:0% +know you could another way of saying + + + align:start position:0% +know you could another way of saying +that is you can make the substitution U + + align:start position:0% +that is you can make the substitution U + + + align:start position:0% +that is you can make the substitution U +equals sin V anyhow you this is all Cal + + align:start position:0% +equals sin V anyhow you this is all Cal + + + align:start position:0% +equals sin V anyhow you this is all Cal +one stuff that hopefully you're pretty + + align:start position:0% +one stuff that hopefully you're pretty + + + align:start position:0% +one stuff that hopefully you're pretty +familiar with so okay so this is equal + + align:start position:0% +familiar with so okay so this is equal + + + align:start position:0% +familiar with so okay so this is equal +to all right so in the end we get sin^2 + + align:start position:0% +to all right so in the end we get sin^2 + + + align:start position:0% +to all right so in the end we get sin^2 +F / 2 between 0 and pi/ 2 okay so we + + align:start position:0% +F / 2 between 0 and pi/ 2 okay so we + + + align:start position:0% +F / 2 between 0 and pi/ 2 okay so we +plug this in so sin^2 Pi / 2 that's 12 + + align:start position:0% +plug this in so sin^2 Pi / 2 that's 12 + + + align:start position:0% +plug this in so sin^2 Pi / 2 that's 12 +minus sin^2 0/ 2 is 0 over 2 so it's + + align:start position:0% +minus sin^2 0/ 2 is 0 over 2 so it's + + + align:start position:0% +minus sin^2 0/ 2 is 0 over 2 so it's +just 1/2 right so the inner integral is + + align:start position:0% +just 1/2 right so the inner integral is + + + align:start position:0% +just 1/2 right so the inner integral is +1/2 so let's see about the outer one + + align:start position:0% +1/2 so let's see about the outer one + + + align:start position:0% +1/2 so let's see about the outer one +outer integral is just the integral from + + align:start position:0% +outer integral is just the integral from + + + align:start position:0% +outer integral is just the integral from +0 to 2 pi D Theta of whatever the inner + + align:start position:0% +0 to 2 pi D Theta of whatever the inner + + + align:start position:0% +0 to 2 pi D Theta of whatever the inner +integral was well the inner integral was + + align:start position:0% +integral was well the inner integral was + + + align:start position:0% +integral was well the inner integral was +1/2 so the integral from 0 to 2 pi of + + align:start position:0% +1/2 so the integral from 0 to 2 pi of + + + align:start position:0% +1/2 so the integral from 0 to 2 pi of +1/2 is pi straight forward good so okay + + align:start position:0% +1/2 is pi straight forward good so okay + + + align:start position:0% +1/2 is pi straight forward good so okay +so that's what the service integral + + align:start position:0% +so that's what the service integral + + + align:start position:0% +so that's what the service integral +gives us so let's go back here and + + align:start position:0% +gives us so let's go back here and + + + align:start position:0% +gives us so let's go back here and +compare so way back at the + + align:start position:0% +compare so way back at the + + + align:start position:0% +compare so way back at the +beginning of this recitation we did the + + align:start position:0% +beginning of this recitation we did the + + + align:start position:0% +beginning of this recitation we did the +line inter integral for this for this + + align:start position:0% +line inter integral for this for this + + + align:start position:0% +line inter integral for this for this +circle that's the boundary of this + + align:start position:0% +circle that's the boundary of this + + + align:start position:0% +circle that's the boundary of this +Hemisphere and we got pi and just now + + align:start position:0% +Hemisphere and we got pi and just now + + + align:start position:0% +Hemisphere and we got pi and just now +what we did is we had the surface + + align:start position:0% +what we did is we had the surface + + + align:start position:0% +what we did is we had the surface +integral the associated surface integral + + align:start position:0% +integral the associated surface integral + + + align:start position:0% +integral the associated surface integral +that we get from Stokes theorem this + + align:start position:0% +that we get from Stokes theorem this + + + align:start position:0% +that we get from Stokes theorem this +curl f.n DS so we had okay we computed F + + align:start position:0% +curl f.n DS so we had okay we computed F + + + align:start position:0% +curl f.n DS so we had okay we computed F +and curl F and N and then we' we' + + align:start position:0% +and curl F and N and then we' we' + + + align:start position:0% +and curl F and N and then we' we' +noticed a little nice symmetry here + + align:start position:0% +noticed a little nice symmetry here + + + align:start position:0% +noticed a little nice symmetry here +although if you didn't notice it you + + align:start position:0% +although if you didn't notice it you + + + align:start position:0% +although if you didn't notice it you +should have been had no trouble + + align:start position:0% +should have been had no trouble + + + align:start position:0% +should have been had no trouble +Computing the the extra terms in the + + align:start position:0% +Computing the the extra terms in the + + + align:start position:0% +Computing the the extra terms in the +integral that you actually ended up with + + align:start position:0% +integral that you actually ended up with + + + align:start position:0% +integral that you actually ended up with +it would have been you know another + + align:start position:0% +it would have been you know another + + + align:start position:0% +it would have been you know another +couple of trig terms there after you + + align:start position:0% +couple of trig terms there after you + + + align:start position:0% +couple of trig terms there after you +made the substitution so we + + align:start position:0% +made the substitution so we + + + align:start position:0% +made the substitution so we +parameterized our surface nicely because + + align:start position:0% +parameterized our surface nicely because + + + align:start position:0% +parameterized our surface nicely because +it's a sphere it's easy to do um and + + align:start position:0% +it's a sphere it's easy to do um and + + + align:start position:0% +it's a sphere it's easy to do um and +then we computed the double integral and + + align:start position:0% +then we computed the double integral and + + + align:start position:0% +then we computed the double integral and +we also came out with pi and we better + + align:start position:0% +we also came out with pi and we better + + + align:start position:0% +we also came out with pi and we better +have also come out with pi because + + align:start position:0% +have also come out with pi because + + + align:start position:0% +have also come out with pi because +Stokes theorem tells us that the line + + align:start position:0% +Stokes theorem tells us that the line + + + align:start position:0% +Stokes theorem tells us that the line +integral and the surface integral have + + align:start position:0% +integral and the surface integral have + + + align:start position:0% +integral and the surface integral have +to give us the same value so that's + + align:start position:0% +to give us the same value so that's + + + align:start position:0% +to give us the same value so that's +great so that's that's exactly what we + + align:start position:0% +great so that's that's exactly what we + + + align:start position:0% +great so that's that's exactly what we +were hoping would happen and now we've + + align:start position:0% +were hoping would happen and now we've + + + align:start position:0% +were hoping would happen and now we've +sort of convinced ourselves hopefully + + align:start position:0% +sort of convinced ourselves hopefully + + + align:start position:0% +sort of convinced ourselves hopefully +that that you know through a through an + + align:start position:0% +that that you know through a through an + + + align:start position:0% +that that you know through a through an +example now we have a maybe feel for + + align:start position:0% +example now we have a maybe feel for + + + align:start position:0% +example now we have a maybe feel for +what sorts of things Stokes theorem can + + align:start position:0% +what sorts of things Stokes theorem can + + + align:start position:0% +what sorts of things Stokes theorem can +do for us I'll end there \ No newline at end of file diff --git a/3SkCNpFOshk.txt b/3SkCNpFOshk.txt new file mode 100644 index 0000000000000000000000000000000000000000..9981758b64efd48dc0f6fcd7f0591144d3a3695d --- /dev/null +++ b/3SkCNpFOshk.txt @@ -0,0 +1,2090 @@ +align:start position:0% + +hi welcome back to recitation in the + + align:start position:0% +hi welcome back to recitation in the + + + align:start position:0% +hi welcome back to recitation in the +lecture we've learned very important + + align:start position:0% +lecture we've learned very important + + + align:start position:0% +lecture we've learned very important +Concepts linear space and linear + + align:start position:0% +Concepts linear space and linear + + + align:start position:0% +Concepts linear space and linear +Subspace well as you can imagine if we + + align:start position:0% +Subspace well as you can imagine if we + + + align:start position:0% +Subspace well as you can imagine if we +call something a space we're putting a + + align:start position:0% +call something a space we're putting a + + + align:start position:0% +call something a space we're putting a +lot of things a lot of objects into one + + align:start position:0% +lot of things a lot of objects into one + + + align:start position:0% +lot of things a lot of objects into one +set but for linear space we want to put + + align:start position:0% +set but for linear space we want to put + + + align:start position:0% +set but for linear space we want to put +them in according to a particular manner + + align:start position:0% +them in according to a particular manner + + + align:start position:0% +them in according to a particular manner +so can you recall what are the + + align:start position:0% +so can you recall what are the + + + align:start position:0% +so can you recall what are the +conditions for a set to be a linear + + align:start position:0% +conditions for a set to be a linear + + + align:start position:0% +conditions for a set to be a linear +space you take any two elements from + + align:start position:0% +space you take any two elements from + + + align:start position:0% +space you take any two elements from +that set take the sum of them you want + + align:start position:0% +that set take the sum of them you want + + + align:start position:0% +that set take the sum of them you want +the sum to be still in the same set + + align:start position:0% +the sum to be still in the same set + + + align:start position:0% +the sum to be still in the same set +that's the first condition second you + + align:start position:0% +that's the first condition second you + + + align:start position:0% +that's the first condition second you +take any multiple of any element from + + align:start position:0% +take any multiple of any element from + + + align:start position:0% +take any multiple of any element from +that set the result will still be in + + align:start position:0% +that set the result will still be in + + + align:start position:0% +that set the result will still be in +that set well that's the second + + align:start position:0% +that set well that's the second + + + align:start position:0% +that set well that's the second +condition okay and if within a linear + + align:start position:0% +condition okay and if within a linear + + + align:start position:0% +condition okay and if within a linear +space you can find a subset set which + + align:start position:0% +space you can find a subset set which + + + align:start position:0% +space you can find a subset set which +also satisfy the two conditions then + + align:start position:0% +also satisfy the two conditions then + + + align:start position:0% +also satisfy the two conditions then +that will give you a + + align:start position:0% +that will give you a + + + align:start position:0% +that will give you a +Subspace today we're going to look at + + align:start position:0% +Subspace today we're going to look at + + + align:start position:0% +Subspace today we're going to look at +this example to review these two + + align:start position:0% +this example to review these two + + + align:start position:0% +this example to review these two +important properties of linear space and + + align:start position:0% +important properties of linear space and + + + align:start position:0% +important properties of linear space and +Subspace okay I have two vectors X1 and + + align:start position:0% +Subspace okay I have two vectors X1 and + + + align:start position:0% +Subspace okay I have two vectors X1 and +X2 both of them are vectors in R3 so as + + align:start position:0% +X2 both of them are vectors in R3 so as + + + align:start position:0% +X2 both of them are vectors in R3 so as +you can see I've drawn them here this is + + align:start position:0% +you can see I've drawn them here this is + + + align:start position:0% +you can see I've drawn them here this is +X1 and this is X2 + + align:start position:0% +X1 and this is X2 + + + align:start position:0% +X1 and this is X2 +so first we want to find the Subspace + + align:start position:0% +so first we want to find the Subspace + + + align:start position:0% +so first we want to find the Subspace +generated by X1 I call it V1 let me say + + align:start position:0% +generated by X1 I call it V1 let me say + + + align:start position:0% +generated by X1 I call it V1 let me say +a word about this generated by so what + + align:start position:0% +a word about this generated by so what + + + align:start position:0% +a word about this generated by so what +do I mean by a Subspace generated by + + align:start position:0% +do I mean by a Subspace generated by + + + align:start position:0% +do I mean by a Subspace generated by +X1 I'm looking for the smallest Subspace + + align:start position:0% +X1 I'm looking for the smallest Subspace + + + align:start position:0% +X1 I'm looking for the smallest Subspace +that contains X1 as small as you can get + + align:start position:0% +that contains X1 as small as you can get + + + align:start position:0% +that contains X1 as small as you can get +okay similarly I want to find out the + + align:start position:0% +okay similarly I want to find out the + + + align:start position:0% +okay similarly I want to find out the +Subspace generated by X 2 call it + + align:start position:0% +Subspace generated by X 2 call it + + + align:start position:0% +Subspace generated by X 2 call it +V2 okay then we want to say something + + align:start position:0% +V2 okay then we want to say something + + + align:start position:0% +V2 okay then we want to say something +about the intersection of V1 and V2 + + align:start position:0% +about the intersection of V1 and V2 + + + align:start position:0% +about the intersection of V1 and V2 +that's the first question and the second + + align:start position:0% +that's the first question and the second + + + align:start position:0% +that's the first question and the second +question we want to put Vector X1 and X2 + + align:start position:0% +question we want to put Vector X1 and X2 + + + align:start position:0% +question we want to put Vector X1 and X2 +together and look at the Subspace + + align:start position:0% +together and look at the Subspace + + + align:start position:0% +together and look at the Subspace +generated by X1 and X2 at the same time + + align:start position:0% +generated by X1 and X2 at the same time + + + align:start position:0% +generated by X1 and X2 at the same time +so I call it + + align:start position:0% +so I call it + + + align:start position:0% +so I call it +V3 and a good question to be asked here + + align:start position:0% +V3 and a good question to be asked here + + + align:start position:0% +V3 and a good question to be asked here +is what is the relation of V3 to V1 un + + align:start position:0% +is what is the relation of V3 to V1 un + + + align:start position:0% +is what is the relation of V3 to V1 un +V2 do you think they're + + align:start position:0% +V2 do you think they're + + + align:start position:0% +V2 do you think they're +equal um within the second question I + + align:start position:0% +equal um within the second question I + + + align:start position:0% +equal um within the second question I +would also like you to find a Subspace + + align:start position:0% +would also like you to find a Subspace + + + align:start position:0% +would also like you to find a Subspace +call it s of V3 such that neither X1 nor + + align:start position:0% +call it s of V3 such that neither X1 nor + + + align:start position:0% +call it s of V3 such that neither X1 nor +X2 is in + + align:start position:0% +X2 is in + + + align:start position:0% +X2 is in +s and the last question is I'd like you + + align:start position:0% +s and the last question is I'd like you + + + align:start position:0% +s and the last question is I'd like you +to say something about the intersection + + align:start position:0% +to say something about the intersection + + + align:start position:0% +to say something about the intersection +of V3 with the XY plane + + align:start position:0% +of V3 with the XY plane + + + align:start position:0% +of V3 with the XY plane +so notice that of course XY plane is + + align:start position:0% +so notice that of course XY plane is + + + align:start position:0% +so notice that of course XY plane is +also a Subspace of R3 so again I'm + + align:start position:0% +also a Subspace of R3 so again I'm + + + align:start position:0% +also a Subspace of R3 so again I'm +looking at the intersection of two + + align:start position:0% +looking at the intersection of two + + + align:start position:0% +looking at the intersection of two +subspaces all right why don't you hit + + align:start position:0% +subspaces all right why don't you hit + + + align:start position:0% +subspaces all right why don't you hit +the pause now and try to solve these + + align:start position:0% +the pause now and try to solve these + + + align:start position:0% +the pause now and try to solve these +three problems on your own and i' like + + align:start position:0% +three problems on your own and i' like + + + align:start position:0% +three problems on your own and i' like +you to identify your answers in this + + align:start position:0% +you to identify your answers in this + + + align:start position:0% +you to identify your answers in this +picture whenever you can I'll come back + + align:start position:0% +picture whenever you can I'll come back + + + align:start position:0% +picture whenever you can I'll come back +later and continue working with + + align:start position:0% +later and continue working with + + + align:start position:0% +later and continue working with +you + + align:start position:0% + + + + align:start position:0% + +okay how did our drawing go let's look + + align:start position:0% +okay how did our drawing go let's look + + + align:start position:0% +okay how did our drawing go let's look +at this together first we want to find + + align:start position:0% +at this together first we want to find + + + align:start position:0% +at this together first we want to find +Subspace generated by X1 so here is X1 + + align:start position:0% +Subspace generated by X1 so here is X1 + + + align:start position:0% +Subspace generated by X1 so here is X1 +let's keep in mind the two conditions + + align:start position:0% +let's keep in mind the two conditions + + + align:start position:0% +let's keep in mind the two conditions +that a Subspace has to satisfy well if I + + align:start position:0% +that a Subspace has to satisfy well if I + + + align:start position:0% +that a Subspace has to satisfy well if I +want to obtain the Subspace at least I + + align:start position:0% +want to obtain the Subspace at least I + + + align:start position:0% +want to obtain the Subspace at least I +have to be able to take any multi + + align:start position:0% +have to be able to take any multi + + + align:start position:0% +have to be able to take any multi +multiple of X1 right so that means at + + align:start position:0% +multiple of X1 right so that means at + + + align:start position:0% +multiple of X1 right so that means at +least I have to include the straight + + align:start position:0% +least I have to include the straight + + + align:start position:0% +least I have to include the straight +line that contains X1 so I'm going to + + align:start position:0% +line that contains X1 so I'm going to + + + align:start position:0% +line that contains X1 so I'm going to +try to draw this straight line here so + + align:start position:0% +try to draw this straight line here so + + + align:start position:0% +try to draw this straight line here so +I'm just simply going to extend this X1 + + align:start position:0% +I'm just simply going to extend this X1 + + + align:start position:0% +I'm just simply going to extend this X1 +along to both directions so + + align:start position:0% + + + + align:start position:0% + +X1 I will try very hard to make it + + align:start position:0% +X1 I will try very hard to make it + + + align:start position:0% +X1 I will try very hard to make it +straight but to be honest it's really + + align:start position:0% +straight but to be honest it's really + + + align:start position:0% +straight but to be honest it's really +hard for me to draw straight lines on + + align:start position:0% +hard for me to draw straight lines on + + + align:start position:0% +hard for me to draw straight lines on +the board okay is that straight seems + + align:start position:0% +the board okay is that straight seems + + + align:start position:0% +the board okay is that straight seems +fine all right so this entire line + + align:start position:0% +fine all right so this entire line + + + align:start position:0% +fine all right so this entire line +contains X1 so at least this line has to + + align:start position:0% +contains X1 so at least this line has to + + + align:start position:0% +contains X1 so at least this line has to +be in V1 is there any anything else + + align:start position:0% +be in V1 is there any anything else + + + align:start position:0% +be in V1 is there any anything else +Beyond this line now let's turn to the + + align:start position:0% +Beyond this line now let's turn to the + + + align:start position:0% +Beyond this line now let's turn to the +second condition the second condition + + align:start position:0% +second condition the second condition + + + align:start position:0% +second condition the second condition +says that we have to be able to take any + + align:start position:0% +says that we have to be able to take any + + + align:start position:0% +says that we have to be able to take any +two elements take the sum and the sum + + align:start position:0% +two elements take the sum and the sum + + + align:start position:0% +two elements take the sum and the sum +will remain in that set does it work for + + align:start position:0% +will remain in that set does it work for + + + align:start position:0% +will remain in that set does it work for +this line you take any + + align:start position:0% +this line you take any + + + align:start position:0% +this line you take any +two vectors on this line or you can say + + align:start position:0% +two vectors on this line or you can say + + + align:start position:0% +two vectors on this line or you can say +any two points on this line and then you + + align:start position:0% +any two points on this line and then you + + + align:start position:0% +any two points on this line and then you +take the sum of them of course you still + + align:start position:0% +take the sum of them of course you still + + + align:start position:0% +take the sum of them of course you still +get something on this line you won't be + + align:start position:0% +get something on this line you won't be + + + align:start position:0% +get something on this line you won't be +able to escape from it right which means + + align:start position:0% +able to escape from it right which means + + + align:start position:0% +able to escape from it right which means +this line is a perfect set that satisfy + + align:start position:0% +this line is a perfect set that satisfy + + + align:start position:0% +this line is a perfect set that satisfy +the two conditions so this line simply + + align:start position:0% +the two conditions so this line simply + + + align:start position:0% +the two conditions so this line simply +gives me + + align:start position:0% +gives me + + + align:start position:0% +gives me +V1 that is the smallest Subspace that + + align:start position:0% +V1 that is the smallest Subspace that + + + align:start position:0% +V1 that is the smallest Subspace that +contains X1 so in other words the + + align:start position:0% +contains X1 so in other words the + + + align:start position:0% +contains X1 so in other words the +Subspace generated by X1 is V1 so + + align:start position:0% +Subspace generated by X1 is V1 so + + + align:start position:0% +Subspace generated by X1 is V1 so +similarly let's look at X2 what is the + + align:start position:0% +similarly let's look at X2 what is the + + + align:start position:0% +similarly let's look at X2 what is the +Subspace generated by X2 again you get + + align:start position:0% +Subspace generated by X2 again you get + + + align:start position:0% +Subspace generated by X2 again you get +the entire straight line that contains + + align:start position:0% +the entire straight line that contains + + + align:start position:0% +the entire straight line that contains +X2 so I'm going to ex extend + + align:start position:0% +X2 so I'm going to ex extend + + + align:start position:0% +X2 so I'm going to ex extend +x2 in both + + align:start position:0% +x2 in both + + + align:start position:0% +x2 in both +directions + + align:start position:0% + + + + align:start position:0% + +I hope it's + + align:start position:0% + + + + align:start position:0% + +straight not too + + align:start position:0% +straight not too + + + align:start position:0% +straight not too +bad that will give me V2 all right V1 V2 + + align:start position:0% +bad that will give me V2 all right V1 V2 + + + align:start position:0% +bad that will give me V2 all right V1 V2 +both of them are subspaces of + + align:start position:0% +both of them are subspaces of + + + align:start position:0% +both of them are subspaces of +R3 now let's look at the intersection of + + align:start position:0% +R3 now let's look at the intersection of + + + align:start position:0% +R3 now let's look at the intersection of +V1 and V2 so we know that both of them + + align:start position:0% +V1 and V2 so we know that both of them + + + align:start position:0% +V1 and V2 so we know that both of them +are straight lines and clearly they're + + align:start position:0% +are straight lines and clearly they're + + + align:start position:0% +are straight lines and clearly they're +not parallel because X1 and X2 are not + + align:start position:0% +not parallel because X1 and X2 are not + + + align:start position:0% +not parallel because X1 and X2 are not +parallel right so what is the + + align:start position:0% +parallel right so what is the + + + align:start position:0% +parallel right so what is the +intersection of V1 and + + align:start position:0% +intersection of V1 and + + + align:start position:0% +intersection of V1 and +vs2 the intersection of V1 and + + align:start position:0% +vs2 the intersection of V1 and + + + align:start position:0% +vs2 the intersection of V1 and +V2 is the only + + align:start position:0% +V2 is the only + + + align:start position:0% +V2 is the only +point at which they cross and where is + + align:start position:0% +point at which they cross and where is + + + align:start position:0% +point at which they cross and where is +that + + align:start position:0% +that + + + align:start position:0% +that +point it's here right at the origin + + align:start position:0% +point it's here right at the origin + + + align:start position:0% +point it's here right at the origin +because both of them pass the origin so + + align:start position:0% +because both of them pass the origin so + + + align:start position:0% +because both of them pass the origin so +that's I'm going to use o to denote + + align:start position:0% +that's I'm going to use o to denote + + + align:start position:0% +that's I'm going to use o to denote +that's the intersection of V1 and + + align:start position:0% +that's the intersection of V1 and + + + align:start position:0% +that's the intersection of V1 and +vs2 this is a set with only one element + + align:start position:0% +vs2 this is a set with only one element + + + align:start position:0% +vs2 this is a set with only one element +what can you say about this + + align:start position:0% +what can you say about this + + + align:start position:0% +what can you say about this +set I claim this is also a Subspace of + + align:start position:0% +set I claim this is also a Subspace of + + + align:start position:0% +set I claim this is also a Subspace of +R3 although by saying space we usually + + align:start position:0% +R3 although by saying space we usually + + + align:start position:0% +R3 although by saying space we usually +mean a lot of objects together but look + + align:start position:0% +mean a lot of objects together but look + + + align:start position:0% +mean a lot of objects together but look +at this set this set fits perfectly into + + align:start position:0% +at this set this set fits perfectly into + + + align:start position:0% +at this set this set fits perfectly into +the conditions of being a linear space + + align:start position:0% +the conditions of being a linear space + + + align:start position:0% +the conditions of being a linear space +you take any multiple of zero + + align:start position:0% +you take any multiple of zero + + + align:start position:0% +you take any multiple of zero +again you get zero 0 + 0 you get zero so + + align:start position:0% +again you get zero 0 + 0 you get zero so + + + align:start position:0% +again you get zero 0 + 0 you get zero so +that's a perfectly fine Subspace of R3 + + align:start position:0% +that's a perfectly fine Subspace of R3 + + + align:start position:0% +that's a perfectly fine Subspace of R3 +all right so what we have got here is I + + align:start position:0% +all right so what we have got here is I + + + align:start position:0% +all right so what we have got here is I +take the intersection of V1 and V2 and + + align:start position:0% +take the intersection of V1 and V2 and + + + align:start position:0% +take the intersection of V1 and V2 and +the result again becomes a Subspace + + align:start position:0% +the result again becomes a Subspace + + + align:start position:0% +the result again becomes a Subspace +which only contains the + + align:start position:0% +which only contains the + + + align:start position:0% +which only contains the +origin that completes the first question + + align:start position:0% +origin that completes the first question + + + align:start position:0% +origin that completes the first question +let's look at the second one in the + + align:start position:0% +let's look at the second one in the + + + align:start position:0% +let's look at the second one in the +second question I want to put X1 and X2 + + align:start position:0% +second question I want to put X1 and X2 + + + align:start position:0% +second question I want to put X1 and X2 +together and look at the Subspace + + align:start position:0% +together and look at the Subspace + + + align:start position:0% +together and look at the Subspace +generated by X1 and + + align:start position:0% +generated by X1 and + + + align:start position:0% +generated by X1 and +X2 and I would also like you to say + + align:start position:0% +X2 and I would also like you to say + + + align:start position:0% +X2 and I would also like you to say +something about the relation between V1 + + align:start position:0% +something about the relation between V1 + + + align:start position:0% +something about the relation between V1 +Union V2 to the sub space generated by + + align:start position:0% +Union V2 to the sub space generated by + + + align:start position:0% +Union V2 to the sub space generated by +x1x2 let's try to answer the second + + align:start position:0% +x1x2 let's try to answer the second + + + align:start position:0% +x1x2 let's try to answer the second +question first is there a chance that V1 + + align:start position:0% +question first is there a chance that V1 + + + align:start position:0% +question first is there a chance that V1 +Union V2 equal to + + align:start position:0% +Union V2 equal to + + + align:start position:0% +Union V2 equal to +V3 okay so what is V1 unit V2 that's + + align:start position:0% +V3 okay so what is V1 unit V2 that's + + + align:start position:0% +V3 okay so what is V1 unit V2 that's +clearly just two lines right this line + + align:start position:0% +clearly just two lines right this line + + + align:start position:0% +clearly just two lines right this line +Union this + + align:start position:0% +Union this + + + align:start position:0% +Union this +line is there a chance that this Union + + align:start position:0% +line is there a chance that this Union + + + align:start position:0% +line is there a chance that this Union +will be a + + align:start position:0% +will be a + + + align:start position:0% +will be a +Subspace let's check the two conditions + + align:start position:0% +Subspace let's check the two conditions + + + align:start position:0% +Subspace let's check the two conditions +first you take any multiple of the + + align:start position:0% +first you take any multiple of the + + + align:start position:0% +first you take any multiple of the +elements in this + + align:start position:0% +elements in this + + + align:start position:0% +elements in this +Union it's either on V it's either on + + align:start position:0% +Union it's either on V it's either on + + + align:start position:0% +Union it's either on V it's either on +this line or on this line since that the + + align:start position:0% +this line or on this line since that the + + + align:start position:0% +this line or on this line since that the +multiple is still going to stay inside + + align:start position:0% +multiple is still going to stay inside + + + align:start position:0% +multiple is still going to stay inside +the union so the first condition is + + align:start position:0% +the union so the first condition is + + + align:start position:0% +the union so the first condition is +actually satisfied what about the second + + align:start position:0% +actually satisfied what about the second + + + align:start position:0% +actually satisfied what about the second +one the second one says that I have to + + align:start position:0% +one the second one says that I have to + + + align:start position:0% +one the second one says that I have to +be able to take any sum the sum of any + + align:start position:0% +be able to take any sum the sum of any + + + align:start position:0% +be able to take any sum the sum of any +two elements from these two lines let's + + align:start position:0% +two elements from these two lines let's + + + align:start position:0% +two elements from these two lines let's +just try a simple sum X1 + X2 so what is + + align:start position:0% +just try a simple sum X1 + X2 so what is + + + align:start position:0% +just try a simple sum X1 + X2 so what is +X1 + + + align:start position:0% + + + + align:start position:0% + +X2 you just sum up each coordinate that + + align:start position:0% +X2 you just sum up each coordinate that + + + align:start position:0% +X2 you just sum up each coordinate that +will give you + + align:start position:0% +will give you + + + align:start position:0% +will give you +two + + align:start position:0% +two + + + align:start position:0% +two + + align:start position:0% + + + + align:start position:0% + +3 in this picture can I draw it in this + + align:start position:0% +3 in this picture can I draw it in this + + + align:start position:0% +3 in this picture can I draw it in this +picture it's going to be + + align:start position:0% + + + + align:start position:0% + +somewhere + + align:start position:0% + + + + align:start position:0% + +here okay that's + + align:start position:0% +here okay that's + + + align:start position:0% +here okay that's +X1 plus + + align:start position:0% +X1 plus + + + align:start position:0% +X1 plus +X3 did you notice + + align:start position:0% +X3 did you notice + + + align:start position:0% +X3 did you notice +something you clearly have got out of + + align:start position:0% +something you clearly have got out of + + + align:start position:0% +something you clearly have got out of +this + + align:start position:0% +this + + + align:start position:0% +this +Union so this sum is not + + align:start position:0% +Union so this sum is not + + + align:start position:0% +Union so this sum is not +inside V1 Union + + align:start position:0% +inside V1 Union + + + align:start position:0% +inside V1 Union +V2 which means V1 Union V2 is not a + + align:start position:0% +V2 which means V1 Union V2 is not a + + + align:start position:0% +V2 which means V1 Union V2 is not a +Subspace then it's impossible that this + + align:start position:0% +Subspace then it's impossible that this + + + align:start position:0% +Subspace then it's impossible that this +Union will equal to + + align:start position:0% +Union will equal to + + + align:start position:0% +Union will equal to +V3 so the second question the answer to + + align:start position:0% +V3 so the second question the answer to + + + align:start position:0% +V3 so the second question the answer to +the second question is no V3 is not + + align:start position:0% +the second question is no V3 is not + + + align:start position:0% +the second question is no V3 is not +equal to V1 un V2 now now let's identify + + align:start position:0% +equal to V1 un V2 now now let's identify + + + align:start position:0% +equal to V1 un V2 now now let's identify +V3 well as you can see since we have + + align:start position:0% +V3 well as you can see since we have + + + align:start position:0% +V3 well as you can see since we have +seen from this argument that we have to + + align:start position:0% +seen from this argument that we have to + + + align:start position:0% +seen from this argument that we have to +be included to be able to include this + + align:start position:0% +be included to be able to include this + + + align:start position:0% +be included to be able to include this +diagonal Vector here but in fact as you + + align:start position:0% +diagonal Vector here but in fact as you + + + align:start position:0% +diagonal Vector here but in fact as you +can see since we can take any elements + + align:start position:0% +can see since we can take any elements + + + align:start position:0% +can see since we can take any elements +from these two lines we're actually + + align:start position:0% +from these two lines we're actually + + + align:start position:0% +from these two lines we're actually +including every Vector on the plane + + align:start position:0% +including every Vector on the plane + + + align:start position:0% +including every Vector on the plane +spent by V1 and V2 so in other words I'm + + align:start position:0% +spent by V1 and V2 so in other words I'm + + + align:start position:0% +spent by V1 and V2 so in other words I'm +actually looking at this huge + + align:start position:0% +actually looking at this huge + + + align:start position:0% +actually looking at this huge +plane + + align:start position:0% + + + + align:start position:0% + +that is spent by + + align:start position:0% +that is spent by + + + align:start position:0% +that is spent by +V1 and + + align:start position:0% +V1 and + + + align:start position:0% +V1 and +V2 that will give me + + align:start position:0% + + + + align:start position:0% + +B3 okay so that's reasonable I'm looking + + align:start position:0% +B3 okay so that's reasonable I'm looking + + + align:start position:0% +B3 okay so that's reasonable I'm looking +at the Subspace generated by two line in + + align:start position:0% +at the Subspace generated by two line in + + + align:start position:0% +at the Subspace generated by two line in +R3 and that two line will be able to + + align:start position:0% +R3 and that two line will be able to + + + align:start position:0% +R3 and that two line will be able to +spend a plane in + + align:start position:0% +spend a plane in + + + align:start position:0% +spend a plane in +R3 okay now um for the last part of + + align:start position:0% +R3 okay now um for the last part of + + + align:start position:0% +R3 okay now um for the last part of +question two I want to find a Subspace + + align:start position:0% +question two I want to find a Subspace + + + align:start position:0% +question two I want to find a Subspace +is s of V3 so I want to find the + + align:start position:0% +is s of V3 so I want to find the + + + align:start position:0% +is s of V3 so I want to find the +Subspace of this plane such that X1 is + + align:start position:0% +Subspace of this plane such that X1 is + + + align:start position:0% +Subspace of this plane such that X1 is +not in s X2 is not in s either so I want + + align:start position:0% +not in s X2 is not in s either so I want + + + align:start position:0% +not in s X2 is not in s either so I want +to stay away from this line and this + + align:start position:0% +to stay away from this line and this + + + align:start position:0% +to stay away from this line and this +line can you find such a Subspace of + + align:start position:0% +line can you find such a Subspace of + + + align:start position:0% +line can you find such a Subspace of +V3 it's right here right because if you + + align:start position:0% +V3 it's right here right because if you + + + align:start position:0% +V3 it's right here right because if you +look at this Vector X1 + X2 sorry that + + align:start position:0% +look at this Vector X1 + X2 sorry that + + + align:start position:0% +look at this Vector X1 + X2 sorry that +should be + + align:start position:0% + + + + align:start position:0% + +X2 + + align:start position:0% +X2 + + + align:start position:0% +X2 +if you look at this vector and if you + + align:start position:0% +if you look at this vector and if you + + + align:start position:0% +if you look at this vector and if you +look at the Subspace generated by this + + align:start position:0% +look at the Subspace generated by this + + + align:start position:0% +look at the Subspace generated by this +Vector again you know it's going to be a + + align:start position:0% +Vector again you know it's going to be a + + + align:start position:0% +Vector again you know it's going to be a +line and this line is right + + align:start position:0% + + + + align:start position:0% + +here this line forms a perfect Subspace + + align:start position:0% +here this line forms a perfect Subspace + + + align:start position:0% +here this line forms a perfect Subspace +of V3 but neither X1 nor X2 is inside + + align:start position:0% +of V3 but neither X1 nor X2 is inside + + + align:start position:0% +of V3 but neither X1 nor X2 is inside +the Subspace so let's just + + align:start position:0% +the Subspace so let's just + + + align:start position:0% +the Subspace so let's just +make it + + align:start position:0% +make it + + + align:start position:0% +make it +s of course the choice is not unique you + + align:start position:0% +s of course the choice is not unique you + + + align:start position:0% +s of course the choice is not unique you +can take twice X1 plus X2 or X1 + twice + + align:start position:0% +can take twice X1 plus X2 or X1 + twice + + + align:start position:0% +can take twice X1 plus X2 or X1 + twice +X2 okay we have completed the second + + align:start position:0% +X2 okay we have completed the second + + + align:start position:0% +X2 okay we have completed the second +problem the last problems ask us to find + + align:start position:0% +problem the last problems ask us to find + + + align:start position:0% +problem the last problems ask us to find +the intersection of V3 with XY plane + + align:start position:0% +the intersection of V3 with XY plane + + + align:start position:0% +the intersection of V3 with XY plane +well just think about that we have + + align:start position:0% +well just think about that we have + + + align:start position:0% +well just think about that we have +identified X V3 as this plane spent by + + align:start position:0% +identified X V3 as this plane spent by + + + align:start position:0% +identified X V3 as this plane spent by +line V1 and V2 + + align:start position:0% +line V1 and V2 + + + align:start position:0% +line V1 and V2 +and XY is also plane so we're talking + + align:start position:0% +and XY is also plane so we're talking + + + align:start position:0% +and XY is also plane so we're talking +about the intersection of two planes in + + align:start position:0% +about the intersection of two planes in + + + align:start position:0% +about the intersection of two planes in +R3 what would that be so you have two + + align:start position:0% +R3 what would that be so you have two + + + align:start position:0% +R3 what would that be so you have two +planes intersect the intersection will + + align:start position:0% +planes intersect the intersection will + + + align:start position:0% +planes intersect the intersection will +be a straight line again right so let's + + align:start position:0% +be a straight line again right so let's + + + align:start position:0% +be a straight line again right so let's +Lo locate that straight line we want to + + align:start position:0% +Lo locate that straight line we want to + + + align:start position:0% +Lo locate that straight line we want to +find something that is inside V3 and XY + + align:start position:0% +find something that is inside V3 and XY + + + align:start position:0% +find something that is inside V3 and XY +plane at the same time what can you say + + align:start position:0% +plane at the same time what can you say + + + align:start position:0% +plane at the same time what can you say +about lines in X what can you say about + + align:start position:0% +about lines in X what can you say about + + + align:start position:0% +about lines in X what can you say about +the points in XY plan + + align:start position:0% +the points in XY plan + + + align:start position:0% +the points in XY plan +the Z coordinate has to be zero okay and + + align:start position:0% +the Z coordinate has to be zero okay and + + + align:start position:0% +the Z coordinate has to be zero okay and +at the same time we know that at least + + align:start position:0% +at the same time we know that at least + + + align:start position:0% +at the same time we know that at least +X1 and X2 are in V3 so did you notice + + align:start position:0% +X1 and X2 are in V3 so did you notice + + + align:start position:0% +X1 and X2 are in V3 so did you notice +that X2 is a vector that lies in V3 but + + align:start position:0% +that X2 is a vector that lies in V3 but + + + align:start position:0% +that X2 is a vector that lies in V3 but +at the same time the Z coordinate of X2 + + align:start position:0% +at the same time the Z coordinate of X2 + + + align:start position:0% +at the same time the Z coordinate of X2 +is + + align:start position:0% +is + + + align:start position:0% +is +zero that is what we're looking for so + + align:start position:0% +zero that is what we're looking for so + + + align:start position:0% +zero that is what we're looking for so +the + + align:start position:0% +the + + + align:start position:0% +the +intersection of + + align:start position:0% + + + + align:start position:0% + +V3 with XY plane will simply + + align:start position:0% +V3 with XY plane will simply + + + align:start position:0% +V3 with XY plane will simply +be the line that contains X2 and here + + align:start position:0% +be the line that contains X2 and here + + + align:start position:0% +be the line that contains X2 and here +we've identified that as + + align:start position:0% +we've identified that as + + + align:start position:0% +we've identified that as +V2 that's it this is a Subspace of R3 + + align:start position:0% +V2 that's it this is a Subspace of R3 + + + align:start position:0% +V2 that's it this is a Subspace of R3 +and this is the sub of R3 the + + align:start position:0% +and this is the sub of R3 the + + + align:start position:0% +and this is the sub of R3 the +intersection is again a Subspace of + + align:start position:0% +intersection is again a Subspace of + + + align:start position:0% +intersection is again a Subspace of +R3 okay I hope you've learned a way to + + align:start position:0% +R3 okay I hope you've learned a way to + + + align:start position:0% +R3 okay I hope you've learned a way to +somehow visualize this linear space and + + align:start position:0% +somehow visualize this linear space and + + + align:start position:0% +somehow visualize this linear space and +Subspace through this + + align:start position:0% +Subspace through this + + + align:start position:0% +Subspace through this +exercise okay thank you for watching and + + align:start position:0% +exercise okay thank you for watching and + + + align:start position:0% +exercise okay thank you for watching and +I'll see you next + + align:start position:0% +I'll see you next + + + align:start position:0% +I'll see you next +time \ No newline at end of file diff --git a/3cN7bSffVm4.txt b/3cN7bSffVm4.txt new file mode 100644 index 0000000000000000000000000000000000000000..1df0c8251546a873bc4924055ed2ca921cc45f63 --- /dev/null +++ b/3cN7bSffVm4.txt @@ -0,0 +1,411 @@ +align:start position:0% + +in the previous video we generated a + + align:start position:0% +in the previous video we generated a + + + align:start position:0% +in the previous video we generated a +cart tree with three splits but why not + + align:start position:0% +cart tree with three splits but why not + + + align:start position:0% +cart tree with three splits but why not +two or four or even five there are + + align:start position:0% +two or four or even five there are + + + align:start position:0% +two or four or even five there are +different ways to control how many + + align:start position:0% +different ways to control how many + + + align:start position:0% +different ways to control how many +splits are generated one way is by + + align:start position:0% +splits are generated one way is by + + + align:start position:0% +splits are generated one way is by +setting a lower bound for the number of + + align:start position:0% +setting a lower bound for the number of + + + align:start position:0% +setting a lower bound for the number of +data points in each subset in R this is + + align:start position:0% +data points in each subset in R this is + + + align:start position:0% +data points in each subset in R this is +called the min bucket parameter for the + + align:start position:0% +called the min bucket parameter for the + + + align:start position:0% +called the min bucket parameter for the +minimum number of observations in each + + align:start position:0% +minimum number of observations in each + + + align:start position:0% +minimum number of observations in each +bucket or subset the smaller min bucket + + align:start position:0% +bucket or subset the smaller min bucket + + + align:start position:0% +bucket or subset the smaller min bucket +is the more splits will be generated but + + align:start position:0% +is the more splits will be generated but + + + align:start position:0% +is the more splits will be generated but +if it's too small overfitting will occur + + align:start position:0% +if it's too small overfitting will occur + + + align:start position:0% +if it's too small overfitting will occur +this means that cart will fit the + + align:start position:0% +this means that cart will fit the + + + align:start position:0% +this means that cart will fit the +training set almost perfectly but this + + align:start position:0% +training set almost perfectly but this + + + align:start position:0% +training set almost perfectly but this +is bad because then the model will + + align:start position:0% +is bad because then the model will + + + align:start position:0% +is bad because then the model will +probably not perform well on test set + + align:start position:0% +probably not perform well on test set + + + align:start position:0% +probably not perform well on test set +data or new data on the other hand if + + align:start position:0% +data or new data on the other hand if + + + align:start position:0% +data or new data on the other hand if +the min bucket parameter is too large + + align:start position:0% +the min bucket parameter is too large + + + align:start position:0% +the min bucket parameter is too large +the model will be too simple and the + + align:start position:0% +the model will be too simple and the + + + align:start position:0% +the model will be too simple and the +accuracy will be poor later in the + + align:start position:0% +accuracy will be poor later in the + + + align:start position:0% +accuracy will be poor later in the +lecture we'll learn about a nice method + + align:start position:0% +lecture we'll learn about a nice method + + + align:start position:0% +lecture we'll learn about a nice method +for selecting the stopping parameter in + + align:start position:0% +for selecting the stopping parameter in + + + align:start position:0% +for selecting the stopping parameter in +each subset of a cart tree we have a + + align:start position:0% +each subset of a cart tree we have a + + + align:start position:0% +each subset of a cart tree we have a +bucket of observations which may contain + + align:start position:0% +bucket of observations which may contain + + + align:start position:0% +bucket of observations which may contain +both possible outcomes in the small + + align:start position:0% +both possible outcomes in the small + + + align:start position:0% +both possible outcomes in the small +example we showed in the previous video + + align:start position:0% +example we showed in the previous video + + + align:start position:0% +example we showed in the previous video +we classify each subset as either red or + + align:start position:0% +we classify each subset as either red or + + + align:start position:0% +we classify each subset as either red or +gray depending on the majority in that + + align:start position:0% +gray depending on the majority in that + + + align:start position:0% +gray depending on the majority in that +subset in the Supreme Court case we'll + + align:start position:0% +subset in the Supreme Court case we'll + + + align:start position:0% +subset in the Supreme Court case we'll +be classifying observations as either + + align:start position:0% +be classifying observations as either + + + align:start position:0% +be classifying observations as either +affirm or reverse instead of just taking + + align:start position:0% +affirm or reverse instead of just taking + + + align:start position:0% +affirm or reverse instead of just taking +the majority outcome to be the + + align:start position:0% +the majority outcome to be the + + + align:start position:0% +the majority outcome to be the +prediction we can compute the percentage + + align:start position:0% +prediction we can compute the percentage + + + align:start position:0% +prediction we can compute the percentage +of data in a subset of each type of + + align:start position:0% +of data in a subset of each type of + + + align:start position:0% +of data in a subset of each type of +outcome as an example if we have a + + align:start position:0% +outcome as an example if we have a + + + align:start position:0% +outcome as an example if we have a +subset with ten affirms and two reverses + + align:start position:0% +subset with ten affirms and two reverses + + + align:start position:0% +subset with ten affirms and two reverses +then 87% of the data is affirmed then + + align:start position:0% +then 87% of the data is affirmed then + + + align:start position:0% +then 87% of the data is affirmed then +just like in logistic regression we can + + align:start position:0% +just like in logistic regression we can + + + align:start position:0% +just like in logistic regression we can +use a threshold value to obtain our + + align:start position:0% +use a threshold value to obtain our + + + align:start position:0% +use a threshold value to obtain our +prediction for this example we would + + align:start position:0% +prediction for this example we would + + + align:start position:0% +prediction for this example we would +predict a firm with a threshold of 0.5 + + align:start position:0% +predict a firm with a threshold of 0.5 + + + align:start position:0% +predict a firm with a threshold of 0.5 +since the majority is affirmed but if we + + align:start position:0% +since the majority is affirmed but if we + + + align:start position:0% +since the majority is affirmed but if we +increase that threshold to 0.9 we would + + align:start position:0% +increase that threshold to 0.9 we would + + + align:start position:0% +increase that threshold to 0.9 we would +predict reverse for this example then by + + align:start position:0% +predict reverse for this example then by + + + align:start position:0% +predict reverse for this example then by +varying the threat + + align:start position:0% +varying the threat + + + align:start position:0% +varying the threat +shoulde value we can compute an ROC + + align:start position:0% +shoulde value we can compute an ROC + + + align:start position:0% +shoulde value we can compute an ROC +curve and compute an AUC value to + + align:start position:0% +curve and compute an AUC value to + + + align:start position:0% +curve and compute an AUC value to +evaluate our model in the next video + + align:start position:0% +evaluate our model in the next video + + + align:start position:0% +evaluate our model in the next video +we'll build a cart tree in our to + + align:start position:0% +we'll build a cart tree in our to + + + align:start position:0% +we'll build a cart tree in our to +predict the decisions of justice Stevens + + align:start position:0% +predict the decisions of justice Stevens + + + align:start position:0% +predict the decisions of justice Stevens +and evaluate our model using an ROC + + align:start position:0% +and evaluate our model using an ROC + + + align:start position:0% +and evaluate our model using an ROC +curve \ No newline at end of file diff --git a/4PlHFcfB8DA.txt b/4PlHFcfB8DA.txt new file mode 100644 index 0000000000000000000000000000000000000000..b8ea035f72f6340c6fd61c60050bcc1061e1dd56 --- /dev/null +++ b/4PlHFcfB8DA.txt @@ -0,0 +1,8616 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit MIT opencourseware + + align:start position:0% +of MIT courses visit MIT opencourseware + + + align:start position:0% +of MIT courses visit MIT opencourseware +at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu + + align:start position:0% +ocw.mit.edu + + + align:start position:0% +ocw.mit.edu +okay so last time the idea was to think + + align:start position:0% +okay so last time the idea was to think + + + align:start position:0% +okay so last time the idea was to think +through a different way or in fact + + align:start position:0% +through a different way or in fact + + + align:start position:0% +through a different way or in fact +several different + + align:start position:0% +several different + + + align:start position:0% +several different +ways to think about discreet time + + align:start position:0% +ways to think about discreet time + + + align:start position:0% +ways to think about discreet time +systems today is a crash + + align:start position:0% +systems today is a crash + + + align:start position:0% +systems today is a crash +course to do the same thing in CT + + align:start position:0% +course to do the same thing in CT + + + align:start position:0% +course to do the same thing in CT +systems so last time for the last week + + align:start position:0% +systems so last time for the last week + + + align:start position:0% +systems so last time for the last week +we've been looking at different kinds of + + align:start position:0% +we've been looking at different kinds of + + + align:start position:0% +we've been looking at different kinds of +representations for DT + + align:start position:0% +representations for DT + + + align:start position:0% +representations for DT +systems difference equations because + + align:start position:0% +systems difference equations because + + + align:start position:0% +systems difference equations because +they're concise and precise block + + align:start position:0% +they're concise and precise block + + + align:start position:0% +they're concise and precise block +diagrams because they let you visualize + + align:start position:0% +diagrams because they let you visualize + + + align:start position:0% +diagrams because they let you visualize +the signal flow paths and operator + + align:start position:0% +the signal flow paths and operator + + + align:start position:0% +the signal flow paths and operator +Expressions because it lets you treat + + align:start position:0% +Expressions because it lets you treat + + + align:start position:0% +Expressions because it lets you treat +systems like + + align:start position:0% +systems like + + + align:start position:0% +systems like +pols what we'll see today is that that + + align:start position:0% +pols what we'll see today is that that + + + align:start position:0% +pols what we'll see today is that that +same kind of strategy Works precisely + + align:start position:0% +same kind of strategy Works precisely + + + align:start position:0% +same kind of strategy Works precisely +the strategy not the answers the same + + align:start position:0% +the strategy not the answers the same + + + align:start position:0% +the strategy not the answers the same +strategy Works precisely for + + align:start position:0% +strategy Works precisely for + + + align:start position:0% +strategy Works precisely for +CT we'll have a concise precise + + align:start position:0% +CT we'll have a concise precise + + + align:start position:0% +CT we'll have a concise precise +representation in terms of differential + + align:start position:0% +representation in terms of differential + + + align:start position:0% +representation in terms of differential +equations which I'm sure you already + + align:start position:0% +equations which I'm sure you already + + + align:start position:0% +equations which I'm sure you already +know all all + + align:start position:0% +know all all + + + align:start position:0% +know all all +about but we will also develop the + + align:start position:0% +about but we will also develop the + + + align:start position:0% +about but we will also develop the +notion of a block diagram so you can + + align:start position:0% +notion of a block diagram so you can + + + align:start position:0% +notion of a block diagram so you can +visualize signal flow + + align:start position:0% +visualize signal flow + + + align:start position:0% +visualize signal flow +paths and we'll have an analogous + + align:start position:0% +paths and we'll have an analogous + + + align:start position:0% +paths and we'll have an analogous +operator the a operator that will let us + + align:start position:0% +operator the a operator that will let us + + + align:start position:0% +operator the a operator that will let us +treat the systems as pols so that's the + + align:start position:0% +treat the systems as pols so that's the + + + align:start position:0% +treat the systems as pols so that's the +overview because it's so similar we'll + + align:start position:0% +overview because it's so similar we'll + + + align:start position:0% +overview because it's so similar we'll +be able to do all of this in one lecture + + align:start position:0% +be able to do all of this in one lecture + + + align:start position:0% +be able to do all of this in one lecture +okay so this is what that's what I mean + + align:start position:0% +okay so this is what that's what I mean + + + align:start position:0% +okay so this is what that's what I mean +by a crash course so this is + + align:start position:0% +by a crash course so this is + + + align:start position:0% +by a crash course so this is +Introduction to CT in 50 + + align:start position:0% +Introduction to CT in 50 + + + align:start position:0% +Introduction to CT in 50 +minutes so you already know a lot about + + align:start position:0% +minutes so you already know a lot about + + + align:start position:0% +minutes so you already know a lot about +how you would represent systems as + + align:start position:0% +how you would represent systems as + + + align:start position:0% +how you would represent systems as +differential equations you've seen this + + align:start position:0% +differential equations you've seen this + + + align:start position:0% +differential equations you've seen this +in other classes uh you should have seen + + align:start position:0% +in other classes uh you should have seen + + + align:start position:0% +in other classes uh you should have seen +this sort of approach in physics you + + align:start position:0% +this sort of approach in physics you + + + align:start position:0% +this sort of approach in physics you +should have seen this sort of approach + + align:start position:0% +should have seen this sort of approach + + + align:start position:0% +should have seen this sort of approach +in math in + + align:start position:0% +in math in + + + align:start position:0% +in math in +1803 uh so we're going to assume that + + align:start position:0% +1803 uh so we're going to assume that + + + align:start position:0% +1803 uh so we're going to assume that +you already know how to think about + + align:start position:0% +you already know how to think about + + + align:start position:0% +you already know how to think about +differential equations and what we're + + align:start position:0% +differential equations and what we're + + + align:start position:0% +differential equations and what we're +going to do is Skip ahead and think + + align:start position:0% +going to do is Skip ahead and think + + + align:start position:0% +going to do is Skip ahead and think +about the alternative representations + + align:start position:0% +about the alternative representations + + + align:start position:0% +about the alternative representations +instead so just like in DT where we + + align:start position:0% +instead so just like in DT where we + + + align:start position:0% +instead so just like in DT where we +thought about block diagrams which gave + + align:start position:0% +thought about block diagrams which gave + + + align:start position:0% +thought about block diagrams which gave +us a way of thinking about signal flow + + align:start position:0% +us a way of thinking about signal flow + + + align:start position:0% +us a way of thinking about signal flow +paths we'll have the same sort of idea + + align:start position:0% +paths we'll have the same sort of idea + + + align:start position:0% +paths we'll have the same sort of idea +in + + align:start position:0% +in + + + align:start position:0% +in +CT the big difference you can anticipate + + align:start position:0% +CT the big difference you can anticipate + + + align:start position:0% +CT the big difference you can anticipate +I mean if the uh CT so in the D in the + + align:start position:0% +I mean if the uh CT so in the D in the + + + align:start position:0% +I mean if the uh CT so in the D in the +difference equation the fundamental + + align:start position:0% +difference equation the fundamental + + + align:start position:0% +difference equation the fundamental +operation in the difference equation was + + align:start position:0% +operation in the difference equation was + + + align:start position:0% +operation in the difference equation was +a delay + + align:start position:0% +a delay + + + align:start position:0% +a delay +operation if you contrast that to a CT + + align:start position:0% +operation if you contrast that to a CT + + + align:start position:0% +operation if you contrast that to a CT +system the fundamental operation is not + + align:start position:0% +system the fundamental operation is not + + + align:start position:0% +system the fundamental operation is not +delay you know from 1803 you know from + + align:start position:0% +delay you know from 1803 you know from + + + align:start position:0% +delay you know from 1803 you know from +physics you know from lots of uh other + + align:start position:0% +physics you know from lots of uh other + + + align:start position:0% +physics you know from lots of uh other +exposures that the fundamental operation + + align:start position:0% +exposures that the fundamental operation + + + align:start position:0% +exposures that the fundamental operation +is + + align:start position:0% +is + + + align:start position:0% +is +differentiation and so the blocks will + + align:start position:0% +differentiation and so the blocks will + + + align:start position:0% +differentiation and so the blocks will +not be built out of delays but will + + align:start position:0% +not be built out of delays but will + + + align:start position:0% +not be built out of delays but will +instead be built out of + + align:start position:0% +instead be built out of + + + align:start position:0% +instead be built out of +integrators apart from that the block + + align:start position:0% +integrators apart from that the block + + + align:start position:0% +integrators apart from that the block +diagram structure looks extremely + + align:start position:0% +diagram structure looks extremely + + + align:start position:0% +diagram structure looks extremely +similar and we'll be able to apply the + + align:start position:0% +similar and we'll be able to apply the + + + align:start position:0% +similar and we'll be able to apply the +same idea that we did in + + align:start position:0% +same idea that we did in + + + align:start position:0% +same idea that we did in +DT to simplify the representation of the + + align:start position:0% +DT to simplify the representation of the + + + align:start position:0% +DT to simplify the representation of the +block diagram by thinking in terms of + + align:start position:0% +block diagram by thinking in terms of + + + align:start position:0% +block diagram by thinking in terms of +operators the operator has to similarly + + align:start position:0% +operators the operator has to similarly + + + align:start position:0% +operators the operator has to similarly +change so the new operator the operator + + align:start position:0% +change so the new operator the operator + + + align:start position:0% +change so the new operator the operator +that we use to represent a CT system + + align:start position:0% +that we use to represent a CT system + + + align:start position:0% +that we use to represent a CT system +we'll call the a operator a is intended + + align:start position:0% +we'll call the a operator a is intended + + + align:start position:0% +we'll call the a operator a is intended +to mean + + align:start position:0% +to mean + + + align:start position:0% +to mean +accumulator the thing that's in my mind + + align:start position:0% +accumulator the thing that's in my mind + + + align:start position:0% +accumulator the thing that's in my mind +when I say the I the a operator is this + + align:start position:0% +when I say the I the a operator is this + + + align:start position:0% +when I say the I the a operator is this +tank this tank accumulates water and you + + align:start position:0% +tank this tank accumulates water and you + + + align:start position:0% +tank this tank accumulates water and you +can think about the relationship between + + align:start position:0% +can think about the relationship between + + + align:start position:0% +can think about the relationship between +the height of the water and the input + + align:start position:0% +the height of the water and the input + + + align:start position:0% +the height of the water and the input +and output rates by some differential + + align:start position:0% +and output rates by some differential + + + align:start position:0% +and output rates by some differential +equation but the point is that the tank + + align:start position:0% +equation but the point is that the tank + + + align:start position:0% +equation but the point is that the tank +itself the + + align:start position:0% +itself the + + + align:start position:0% +itself the +system accumulates and that's what we + + align:start position:0% +system accumulates and that's what we + + + align:start position:0% +system accumulates and that's what we +want to have in our heads when we think + + align:start position:0% +want to have in our heads when we think + + + align:start position:0% +want to have in our heads when we think +about the a oper op Ator so the a + + align:start position:0% +about the a oper op Ator so the a + + + align:start position:0% +about the a oper op Ator so the a +operator is going to be like the r + + align:start position:0% +operator is going to be like the r + + + align:start position:0% +operator is going to be like the r +operator you'll apply the r operator to + + align:start position:0% +operator you'll apply the r operator to + + + align:start position:0% +operator you'll apply the r operator to +a discrete time signal to generate a new + + align:start position:0% +a discrete time signal to generate a new + + + align:start position:0% +a discrete time signal to generate a new +discrete time signal that was shifted to + + align:start position:0% +discrete time signal that was shifted to + + + align:start position:0% +discrete time signal that was shifted to +the right that's what R meant R was + + align:start position:0% +the right that's what R meant R was + + + align:start position:0% +the right that's what R meant R was +right so right shift + + align:start position:0% +right so right shift + + + align:start position:0% +right so right shift +operator here you'll apply the a + + align:start position:0% +operator here you'll apply the a + + + align:start position:0% +operator here you'll apply the a +operator to the X signal X is now CT + + align:start position:0% +operator to the X signal X is now CT + + + align:start position:0% +operator to the X signal X is now CT +continuous + + align:start position:0% +continuous + + + align:start position:0% +continuous +time and when you apply the a operator + + align:start position:0% +time and when you apply the a operator + + + align:start position:0% +time and when you apply the a operator +to a signal X it generates a whole new + + align:start position:0% +to a signal X it generates a whole new + + + align:start position:0% +to a signal X it generates a whole new +signal y that is everywhere equal to the + + align:start position:0% +signal y that is everywhere equal to the + + + align:start position:0% +signal y that is everywhere equal to the +indefinite integral of the input signal + + align:start position:0% +indefinite integral of the input signal + + + align:start position:0% +indefinite integral of the input signal +so the a operator is start with the + + align:start position:0% +so the a operator is start with the + + + align:start position:0% +so the a operator is start with the +input signal X and integrate it with + + align:start position:0% +input signal X and integrate it with + + + align:start position:0% +input signal X and integrate it with +regard to time starting at minus + + align:start position:0% +regard to time starting at minus + + + align:start position:0% +regard to time starting at minus +infinity and going up to T that's the + + align:start position:0% +infinity and going up to T that's the + + + align:start position:0% +infinity and going up to T that's the +teeth + + align:start position:0% +teeth + + + align:start position:0% +teeth +value of the output + + align:start position:0% +value of the output + + + align:start position:0% +value of the output +signal okay + + align:start position:0% +signal okay + + + align:start position:0% +signal okay +simple so let's see how simple + + align:start position:0% +simple so let's see how simple + + + align:start position:0% +simple so let's see how simple +so here's a bunch of block diagrams + + align:start position:0% +so here's a bunch of block diagrams + + + align:start position:0% +so here's a bunch of block diagrams +written in terms of a here's a here's a + + align:start position:0% +written in terms of a here's a here's a + + + align:start position:0% +written in terms of a here's a here's a +bunch of differential equations figure + + align:start position:0% +bunch of differential equations figure + + + align:start position:0% +bunch of differential equations figure +out the correspondence if + + align:start position:0% +out the correspondence if + + + align:start position:0% +out the correspondence if +any okay traditionally it seems that + + align:start position:0% +any okay traditionally it seems that + + + align:start position:0% +any okay traditionally it seems that +people are quiet so before you start say + + align:start position:0% +people are quiet so before you start say + + + align:start position:0% +people are quiet so before you start say +something that has nothing to do with3 + + align:start position:0% +something that has nothing to do with3 + + + align:start position:0% +something that has nothing to do with3 +to your next door neighbor it has to + + align:start position:0% +to your next door neighbor it has to + + + align:start position:0% +to your next door neighbor it has to +have nothing to do + + align:start position:0% +have nothing to do + + + align:start position:0% +have nothing to do +with3 and then figure out which of these + + align:start position:0% +with3 and then figure out which of these + + + align:start position:0% +with3 and then figure out which of these +bottom diagrams number 1 2 3 4 or none + + align:start position:0% +bottom diagrams number 1 2 3 4 or none + + + align:start position:0% +bottom diagrams number 1 2 3 4 or none +of them corresponds best to the + + align:start position:0% + + + + align:start position:0% + +correspondence + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +okay you've got 30 seconds to answer the + + align:start position:0% +okay you've got 30 seconds to answer the + + + align:start position:0% +okay you've got 30 seconds to answer the +question now + + align:start position:0% + + + + align:start position:0% + +well that killed + + align:start position:0% + + + + align:start position:0% + +everything + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +[Applause] + + align:start position:0% + + + + align:start position:0% + +okay everybody raise your hand and tell + + align:start position:0% +okay everybody raise your hand and tell + + + align:start position:0% +okay everybody raise your hand and tell +me which of the five available answers + + align:start position:0% +me which of the five available answers + + + align:start position:0% +me which of the five available answers +one through five best illustrates the + + align:start position:0% +one through five best illustrates the + + + align:start position:0% +one through five best illustrates the +correspondence raise your hands let me + + align:start position:0% +correspondence raise your hands let me + + + align:start position:0% +correspondence raise your hands let me +see how many of you figured it + + align:start position:0% +see how many of you figured it + + + align:start position:0% +see how many of you figured it +out remember if you're wrong you can + + align:start position:0% +out remember if you're wrong you can + + + align:start position:0% +out remember if you're wrong you can +blame it on your partner + + align:start position:0% +blame it on your partner + + + align:start position:0% +blame it on your partner +okay it's more than 95% correct how do + + align:start position:0% +okay it's more than 95% correct how do + + + align:start position:0% +okay it's more than 95% correct how do +you think about it what do I do + + align:start position:0% + + + + align:start position:0% + +first equation write an so which what do + + align:start position:0% +first equation write an so which what do + + + align:start position:0% +first equation write an so which what do +you want me to look at first this + + align:start position:0% +you want me to look at first this + + + align:start position:0% +you want me to look at first this +diagram that equation this diagram that + + align:start position:0% +diagram that equation this diagram that + + + align:start position:0% +diagram that equation this diagram that +equation write an equation for each of + + align:start position:0% +equation write an equation for each of + + + align:start position:0% +equation write an equation for each of +the diagrams how would I figure out an + + align:start position:0% +the diagrams how would I figure out an + + + align:start position:0% +the diagrams how would I figure out an +equation for that + + align:start position:0% +equation for that + + + align:start position:0% +equation for that +diagram yeah at what coming in out sign + + align:start position:0% +diagram yeah at what coming in out sign + + + align:start position:0% +diagram yeah at what coming in out sign +so look at what's coming in and out of + + align:start position:0% +so look at what's coming in and out of + + + align:start position:0% +so look at what's coming in and out of +the plus sign that's very good so so + + align:start position:0% +the plus sign that's very good so so + + + align:start position:0% +the plus sign that's very good so so +let's focus on the coming out first + + align:start position:0% +let's focus on the coming out first + + + align:start position:0% +let's focus on the coming out first +what's the name of that + + align:start position:0% + + + + align:start position:0% + +signal well I can think of two names + + align:start position:0% +signal well I can think of two names + + + align:start position:0% +signal well I can think of two names +right that's why it's a good idea to + + align:start position:0% +right that's why it's a good idea to + + + align:start position:0% +right that's why it's a good idea to +look at what's coming in and + + align:start position:0% +look at what's coming in and + + + align:start position:0% +look at what's coming in and +out one way that I could name this would + + align:start position:0% +out one way that I could name this would + + + align:start position:0% +out one way that I could name this would +be with reference to the a + + align:start position:0% +be with reference to the a + + + align:start position:0% +be with reference to the a +operator if I know that what comes out + + align:start position:0% +operator if I know that what comes out + + + align:start position:0% +operator if I know that what comes out +of the a operator is capital Y what goes + + align:start position:0% +of the a operator is capital Y what goes + + + align:start position:0% +of the a operator is capital Y what goes +into the a + + align:start position:0% + + + + align:start position:0% + +operator the + + align:start position:0% +operator the + + + align:start position:0% +operator the +derivative so if I know that what comes + + align:start position:0% +derivative so if I know that what comes + + + align:start position:0% +derivative so if I know that what comes +out is y then that what goes in must + + align:start position:0% +out is y then that what goes in must + + + align:start position:0% +out is y then that what goes in must +have been y + + align:start position:0% +have been y + + + align:start position:0% +have been y +dot right but that also has to be the + + align:start position:0% +dot right but that also has to be the + + + align:start position:0% +dot right but that also has to be the +output of the adder so what were the two + + align:start position:0% +output of the adder so what were the two + + + align:start position:0% +output of the adder so what were the two +inputs of the + + align:start position:0% +inputs of the + + + align:start position:0% +inputs of the +adder X + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +py + + align:start position:0% +py + + + align:start position:0% +py +right so y dot the thing that goes into + + align:start position:0% +right so y dot the thing that goes into + + + align:start position:0% +right so y dot the thing that goes into +the accumulator has to be the same as X + + align:start position:0% +the accumulator has to be the same as X + + + align:start position:0% +the accumulator has to be the same as X +Plus py okay so y dot is X Plus py so + + align:start position:0% +Plus py okay so y dot is X Plus py so + + + align:start position:0% +Plus py okay so y dot is X Plus py so +there's a correspondence between these + + align:start position:0% +there's a correspondence between these + + + align:start position:0% +there's a correspondence between these +two everybody sort of get the + + align:start position:0% +two everybody sort of get the + + + align:start position:0% +two everybody sort of get the +idea we can do the same sort of thing + + align:start position:0% +idea we can do the same sort of thing + + + align:start position:0% +idea we can do the same sort of thing +here what's the name of that + + align:start position:0% + + + + align:start position:0% + +signal + + align:start position:0% +signal + + + align:start position:0% +signal +sh y do over P exactly so that that + + align:start position:0% +sh y do over P exactly so that that + + + align:start position:0% +sh y do over P exactly so that that +one's going to be y dot over p and + + align:start position:0% +one's going to be y dot over p and + + + align:start position:0% +one's going to be y dot over p and +that's going to have to be the same as + + align:start position:0% +that's going to have to be the same as + + + align:start position:0% +that's going to have to be the same as +uh X Plus + + align:start position:0% +uh X Plus + + + align:start position:0% +uh X Plus +y so if you cleared the fraction here + + align:start position:0% +y so if you cleared the fraction here + + + align:start position:0% +y so if you cleared the fraction here +you would find that y dot is PX plus py + + align:start position:0% +you would find that y dot is PX plus py + + + align:start position:0% +you would find that y dot is PX plus py +so there's a correspondence that + + align:start position:0% + + + + align:start position:0% + +way + + align:start position:0% +way + + + align:start position:0% +way +right and you can do the same sort of + + align:start position:0% +right and you can do the same sort of + + + align:start position:0% +right and you can do the same sort of +thing down here right it's it looks a + + align:start position:0% +thing down here right it's it looks a + + + align:start position:0% +thing down here right it's it looks a +little bit different what's this this + + align:start position:0% +little bit different what's this this + + + align:start position:0% +little bit different what's this this +says that the output of the adder + + align:start position:0% +says that the output of the adder + + + align:start position:0% +says that the output of the adder +y right the output of the adder here is + + align:start position:0% +y right the output of the adder here is + + + align:start position:0% +y right the output of the adder here is +y so y must have been X Plus + + align:start position:0% + + + + align:start position:0% + +what so P * the + + align:start position:0% +what so P * the + + + align:start position:0% +what so P * the +integral of + + align:start position:0% +integral of + + + align:start position:0% +integral of +Y right and I'd like to write that in a + + align:start position:0% +Y right and I'd like to write that in a + + + align:start position:0% +Y right and I'd like to write that in a +differential form so I could + + align:start position:0% +differential form so I could + + + align:start position:0% +differential form so I could +differentiate term by term to say that + + align:start position:0% +differentiate term by term to say that + + + align:start position:0% +differentiate term by term to say that +that's the same thing as y dot is X do + + align:start position:0% +that's the same thing as y dot is X do + + + align:start position:0% +that's the same thing as y dot is X do +plus + + align:start position:0% +plus + + + align:start position:0% +plus +py uh so y dot is x dot plus py so those + + align:start position:0% +py uh so y dot is x dot plus py so those + + + align:start position:0% +py uh so y dot is x dot plus py so those +correspondence that way so the answer is + + align:start position:0% +correspondence that way so the answer is + + + align:start position:0% +correspondence that way so the answer is +one okay everybody's happy with that so + + align:start position:0% +one okay everybody's happy with that so + + + align:start position:0% +one okay everybody's happy with that so +the point is that the differential + + align:start position:0% +the point is that the differential + + + align:start position:0% +the point is that the differential +operators look very much the same you + + align:start position:0% +operators look very much the same you + + + align:start position:0% +operators look very much the same you +can use the same kind of reasoning that + + align:start position:0% +can use the same kind of reasoning that + + + align:start position:0% +can use the same kind of reasoning that +you did for difference equations with + + align:start position:0% +you did for difference equations with + + + align:start position:0% +you did for difference equations with +r of course the operators are + + align:start position:0% +r of course the operators are + + + align:start position:0% +r of course the operators are +different and just like + + align:start position:0% +different and just like + + + align:start position:0% +different and just like +R you can think about these things as + + align:start position:0% +R you can think about these things as + + + align:start position:0% +R you can think about these things as +pols so if you think about this feed + + align:start position:0% +pols so if you think about this feed + + + align:start position:0% +pols so if you think about this feed +forward + + align:start position:0% +forward + + + align:start position:0% +forward +system that's now CT not DT the feed + + align:start position:0% +system that's now CT not DT the feed + + + align:start position:0% +system that's now CT not DT the feed +forward system says that I could + + align:start position:0% +forward system says that I could + + + align:start position:0% +forward system says that I could +construct W by taking uh X plus a x X + + align:start position:0% +construct W by taking uh X plus a x X + + + align:start position:0% +construct W by taking uh X plus a x X +Plus ax or that's X plus the derivative + + align:start position:0% +Plus ax or that's X plus the derivative + + + align:start position:0% +Plus ax or that's X plus the derivative +the integral of x + + align:start position:0% +the integral of x + + + align:start position:0% +the integral of x +right then I could think about the Y + + align:start position:0% +right then I could think about the Y + + + align:start position:0% +right then I could think about the Y +signal as W plus the integral of + + align:start position:0% +signal as W plus the integral of + + + align:start position:0% +signal as W plus the integral of +w so that's this one y is W plus the + + align:start position:0% +w so that's this one y is W plus the + + + align:start position:0% +w so that's this one y is W plus the +integral of w and now I can substitute + + align:start position:0% +integral of w and now I can substitute + + + align:start position:0% +integral of w and now I can substitute +instances of this into + + align:start position:0% +instances of this into + + + align:start position:0% +instances of this into +here right so this W expression could go + + align:start position:0% +here right so this W expression could go + + + align:start position:0% +here right so this W expression could go +in there and that gives me + + align:start position:0% +in there and that gives me + + + align:start position:0% +in there and that gives me +this if I integrated this W expression + + align:start position:0% +this if I integrated this W expression + + + align:start position:0% +this if I integrated this W expression +once then I would get the integral of + + align:start position:0% +once then I would get the integral of + + + align:start position:0% +once then I would get the integral of +that plus the double integral of that so + + align:start position:0% +that plus the double integral of that so + + + align:start position:0% +that plus the double integral of that so +that gives me + + align:start position:0% +that gives me + + + align:start position:0% +that gives me +these and now I think about those things + + align:start position:0% +these and now I think about those things + + + align:start position:0% +these and now I think about those things +in terms of A's and I get precisely the + + align:start position:0% +in terms of A's and I get precisely the + + + align:start position:0% +in terms of A's and I get precisely the +same + + align:start position:0% +same + + + align:start position:0% +same +expression so the idea is just like R + + align:start position:0% +expression so the idea is just like R + + + align:start position:0% +expression so the idea is just like R +you can manipulate + + align:start position:0% +you can manipulate + + + align:start position:0% +you can manipulate +operator U expressions in R like they + + align:start position:0% +operator U expressions in R like they + + + align:start position:0% +operator U expressions in R like they +were pols you can you can um manipulate + + align:start position:0% +were pols you can you can um manipulate + + + align:start position:0% +were pols you can you can um manipulate +operator expressions in + + align:start position:0% +operator expressions in + + + align:start position:0% +operator expressions in +a just like they were + + align:start position:0% +a just like they were + + + align:start position:0% +a just like they were +polinomial and the reason I can say that + + align:start position:0% +polinomial and the reason I can say that + + + align:start position:0% +polinomial and the reason I can say that +is that if I think through all the + + align:start position:0% +is that if I think through all the + + + align:start position:0% +is that if I think through all the +properties of polinomial I can draw an + + align:start position:0% +properties of polinomial I can draw an + + + align:start position:0% +properties of polinomial I can draw an +isomorphism between the way the system + + align:start position:0% +isomorphism between the way the system + + + align:start position:0% +isomorphism between the way the system +would have behaved and the way the + + align:start position:0% +would have behaved and the way the + + + align:start position:0% +would have behaved and the way the +polinomial would have behaved and in + + align:start position:0% +polinomial would have behaved and in + + + align:start position:0% +polinomial would have behaved and in +particular here's three statements that + + align:start position:0% +particular here's three statements that + + + align:start position:0% +particular here's three statements that +have to be + + align:start position:0% +have to be + + + align:start position:0% +have to be +true if the operator Expressions were + + align:start position:0% +true if the operator Expressions were + + + align:start position:0% +true if the operator Expressions were +supposed to behave like polinomial + + align:start position:0% +supposed to behave like polinomial + + + align:start position:0% +supposed to behave like polinomial +polinomial have the property that the + + align:start position:0% +polinomial have the property that the + + + align:start position:0% +polinomial have the property that the +the that uh polinomial in a should + + align:start position:0% +the that uh polinomial in a should + + + align:start position:0% +the that uh polinomial in a should +commute polinomial should have the the a + + align:start position:0% +commute polinomial should have the the a + + + align:start position:0% +commute polinomial should have the the a +should have the distributive property + + align:start position:0% +should have the distributive property + + + align:start position:0% +should have the distributive property +multiplication over addition + + align:start position:0% +multiplication over addition + + + align:start position:0% +multiplication over addition +and uh polinomial should associate and + + align:start position:0% +and uh polinomial should associate and + + + align:start position:0% +and uh polinomial should associate and +if you think about each of those in + + align:start position:0% +if you think about each of those in + + + align:start position:0% +if you think about each of those in +detail the operations that would + + align:start position:0% +detail the operations that would + + + align:start position:0% +detail the operations that would +correspond to what you put in the block + + align:start position:0% +correspond to what you put in the block + + + align:start position:0% +correspond to what you put in the block +diagram have precisely those same + + align:start position:0% +diagram have precisely those same + + + align:start position:0% +diagram have precisely those same +relations so that's the the outline of + + align:start position:0% +relations so that's the the outline of + + + align:start position:0% +relations so that's the the outline of +how you would go about proving something + + align:start position:0% +how you would go about proving something + + + align:start position:0% +how you would go about proving something +like this but the takeaway message is + + align:start position:0% +like this but the takeaway message is + + + align:start position:0% +like this but the takeaway message is +the operator expressions in + + align:start position:0% +the operator expressions in + + + align:start position:0% +the operator expressions in +a obey all the rules that you would + + align:start position:0% +a obey all the rules that you would + + + align:start position:0% +a obey all the rules that you would +expect from a + + align:start position:0% +expect from a + + + align:start position:0% +expect from a +polinomial so + + align:start position:0% +polinomial so + + + align:start position:0% +polinomial so +second question think about these two + + align:start position:0% +second question think about these two + + + align:start position:0% +second question think about these two +systems and think about the notion of + + align:start position:0% +systems and think about the notion of + + + align:start position:0% +systems and think about the notion of +equivalent equivalent + + align:start position:0% +equivalent equivalent + + + align:start position:0% +equivalent equivalent +here is going to be just the same as it + + align:start position:0% +here is going to be just the same as it + + + align:start position:0% +here is going to be just the same as it +was in D in DT and DT equivalent meant + + align:start position:0% +was in D in DT and DT equivalent meant + + + align:start position:0% +was in D in DT and DT equivalent meant +if all of the right shift operators + + align:start position:0% +if all of the right shift operators + + + align:start position:0% +if all of the right shift operators +started at rest that is to say their + + align:start position:0% +started at rest that is to say their + + + align:start position:0% +started at rest that is to say their +output was Zero we will have the same + + align:start position:0% +output was Zero we will have the same + + + align:start position:0% +output was Zero we will have the same +kind of notion + + align:start position:0% +kind of notion + + + align:start position:0% +kind of notion +here at rest is going to mean all the + + align:start position:0% +here at rest is going to mean all the + + + align:start position:0% +here at rest is going to mean all the +integrators integrators have a starting + + align:start position:0% +integrators integrators have a starting + + + align:start position:0% +integrators integrators have a starting +value an initial value + + align:start position:0% +value an initial value + + + align:start position:0% +value an initial value +if those initial values are all zero + + align:start position:0% +if those initial values are all zero + + + align:start position:0% +if those initial values are all zero +then we say that the system started at + + align:start position:0% +then we say that the system started at + + + align:start position:0% +then we say that the system started at +rest we have that same kind of Proviso + + align:start position:0% +rest we have that same kind of Proviso + + + align:start position:0% +rest we have that same kind of Proviso +given that Proviso then all of the + + align:start position:0% +given that Proviso then all of the + + + align:start position:0% +given that Proviso then all of the +operator Expressions behave like pols so + + align:start position:0% +operator Expressions behave like pols so + + + align:start position:0% +operator Expressions behave like pols so +tell me uh determine K1 so that these + + align:start position:0% +tell me uh determine K1 so that these + + + align:start position:0% +tell me uh determine K1 so that these +two systems are equivalent given that + + align:start position:0% +two systems are equivalent given that + + + align:start position:0% +two systems are equivalent given that +definition of + + align:start position:0% + + + + align:start position:0% + +equivalence + + align:start position:0% + + + + align:start position:0% + +for + + align:start position:0% + + + + align:start position:0% + +for + + align:start position:0% + + + + align:start position:0% + +for + + align:start position:0% + + + + align:start position:0% + +for + + align:start position:0% + + + + align:start position:0% + +for + + align:start position:0% + + + + align:start position:0% + +so anyone have an + + align:start position:0% +so anyone have an + + + align:start position:0% +so anyone have an +answer so how should I choose K1 if I + + align:start position:0% +answer so how should I choose K1 if I + + + align:start position:0% +answer so how should I choose K1 if I +want those two systems to be equivalent + + align:start position:0% +want those two systems to be equivalent + + + align:start position:0% +want those two systems to be equivalent +yes raise your + + align:start position:0% + + + + align:start position:0% + +hands okay it was a trick question so + + align:start position:0% +hands okay it was a trick question so + + + align:start position:0% +hands okay it was a trick question so +now given the additional information + + align:start position:0% +now given the additional information + + + align:start position:0% +now given the additional information +that it was a trick question revise your + + align:start position:0% +that it was a trick question revise your + + + align:start position:0% +that it was a trick question revise your +answers ah excellent excellent instant + + align:start position:0% +answers ah excellent excellent instant + + + align:start position:0% +answers ah excellent excellent instant +revisions wonderful okay what was the + + align:start position:0% +revisions wonderful okay what was the + + + align:start position:0% +revisions wonderful okay what was the +trick + + align:start position:0% + + + + align:start position:0% + +oh come on you all got it what was the + + align:start position:0% +oh come on you all got it what was the + + + align:start position:0% +oh come on you all got it what was the +trick yeah beus 1.6 it should have been + + align:start position:0% +trick yeah beus 1.6 it should have been + + + align:start position:0% +trick yeah beus 1.6 it should have been +minus 1.6 yes so H how so what do you do + + align:start position:0% +minus 1.6 yes so H how so what do you do + + + align:start position:0% +minus 1.6 yes so H how so what do you do +what do I do first in order to answer a + + align:start position:0% +what do I do first in order to answer a + + + align:start position:0% +what do I do first in order to answer a +question like + + align:start position:0% + + + + align:start position:0% + +this well come on right so translate the + + align:start position:0% +this well come on right so translate the + + + align:start position:0% +this well come on right so translate the +block diagrams into a differential + + align:start position:0% +block diagrams into a differential + + + align:start position:0% +block diagrams into a differential +equation that's a good approach right + + align:start position:0% +equation that's a good approach right + + + align:start position:0% +equation that's a good approach right +because what we like to do is figure out + + align:start position:0% +because what we like to do is figure out + + + align:start position:0% +because what we like to do is figure out +an equivalence + + align:start position:0% +an equivalence + + + align:start position:0% +an equivalence +the equivalence is not + + align:start position:0% +the equivalence is not + + + align:start position:0% +the equivalence is not +trivial so in fact the equivalence is + + align:start position:0% +trivial so in fact the equivalence is + + + align:start position:0% +trivial so in fact the equivalence is +easier to think about if you do + + align:start position:0% +easier to think about if you do + + + align:start position:0% +easier to think about if you do +polinomial you could try to manipulate + + align:start position:0% +polinomial you could try to manipulate + + + align:start position:0% +polinomial you could try to manipulate +the blocks to make them look the same + + align:start position:0% +the blocks to make them look the same + + + align:start position:0% +the blocks to make them look the same +that's actually + + align:start position:0% +that's actually + + + align:start position:0% +that's actually +hard but it's pretty easy to do it if + + align:start position:0% +hard but it's pretty easy to do it if + + + align:start position:0% +hard but it's pretty easy to do it if +you think about the um block diagrams + + align:start position:0% +you think about the um block diagrams + + + align:start position:0% +you think about the um block diagrams +being represented as um functional oper + + align:start position:0% +being represented as um functional oper + + + align:start position:0% +being represented as um functional oper +as operators so you can look at the + + align:start position:0% +as operators so you can look at the + + + align:start position:0% +as operators so you can look at the +first one and you can say Okay w is the + + align:start position:0% +first one and you can say Okay w is the + + + align:start position:0% +first one and you can say Okay w is the +signal that when that comes out of a + + align:start position:0% +signal that when that comes out of a + + + align:start position:0% +signal that when that comes out of a +operating on x + + align:start position:0% +operating on x + + + align:start position:0% +operating on x +minus 7 W right that's what that Adder + + align:start position:0% +minus 7 W right that's what that Adder + + + align:start position:0% +minus 7 W right that's what that Adder +says + + align:start position:0% +says + + + align:start position:0% +says +right and you can similarly do this box + + align:start position:0% +right and you can similarly do this box + + + align:start position:0% +right and you can similarly do this box +it looks the same treat them as pols and + + align:start position:0% +it looks the same treat them as pols and + + + align:start position:0% +it looks the same treat them as pols and +you can reduce it to some equivalent + + align:start position:0% + + + + align:start position:0% + +form everyone have the gist of what I'm + + align:start position:0% +form everyone have the gist of what I'm + + + align:start position:0% +form everyone have the gist of what I'm +what's going on same thing down here the + + align:start position:0% +what's going on same thing down here the + + + align:start position:0% +what's going on same thing down here the +equations look a little bit different + + align:start position:0% +equations look a little bit different + + + align:start position:0% +equations look a little bit different +but it's the same idea you figure out + + align:start position:0% +but it's the same idea you figure out + + + align:start position:0% +but it's the same idea you figure out +what are the constraints imposed by the + + align:start position:0% +what are the constraints imposed by the + + + align:start position:0% +what are the constraints imposed by the +blocks the output of every a has to be + + align:start position:0% +blocks the output of every a has to be + + + align:start position:0% +blocks the output of every a has to be +the integral of the thing that went into + + align:start position:0% +the integral of the thing that went into + + + align:start position:0% +the integral of the thing that went into +it the output of every Adder has to be + + align:start position:0% +it the output of every Adder has to be + + + align:start position:0% +it the output of every Adder has to be +the sum of the two things that went into + + align:start position:0% +the sum of the two things that went into + + + align:start position:0% +the sum of the two things that went into +it figure out all those constraints + + align:start position:0% +it figure out all those constraints + + + align:start position:0% +it figure out all those constraints +reduce them to pols and then manipulate + + align:start position:0% +reduce them to pols and then manipulate + + + align:start position:0% +reduce them to pols and then manipulate +them as though they were pols and the + + align:start position:0% +them as though they were pols and the + + + align:start position:0% +them as though they were pols and the +polinomial manipulation shows that minus + + align:start position:0% +polinomial manipulation shows that minus + + + align:start position:0% +polinomial manipulation shows that minus +K1 should be 1.6 so K1 should be minus + + align:start position:0% +K1 should be 1.6 so K1 should be minus + + + align:start position:0% +K1 should be 1.6 so K1 should be minus +1.6 right point is it's easy right if + + align:start position:0% +1.6 right point is it's easy right if + + + align:start position:0% +1.6 right point is it's easy right if +you know pols you know the answer that's + + align:start position:0% +you know pols you know the answer that's + + + align:start position:0% +you know pols you know the answer that's +pretty good right so we're doing + + align:start position:0% +pretty good right so we're doing + + + align:start position:0% +pretty good right so we're doing +something completely different from + + align:start position:0% +something completely different from + + + align:start position:0% +something completely different from +pols but we're able to use the + + align:start position:0% +pols but we're able to use the + + + align:start position:0% +pols but we're able to use the +intuitions that we get from polinomial + + align:start position:0% +intuitions that we get from polinomial + + + align:start position:0% +intuitions that we get from polinomial +in order to do the + + align:start position:0% +in order to do the + + + align:start position:0% +in order to do the +problem there's one remaining + + align:start position:0% +problem there's one remaining + + + align:start position:0% +problem there's one remaining +problem something that is harder than it + + align:start position:0% +problem something that is harder than it + + + align:start position:0% +problem something that is harder than it +is in DT probably the hardest part of CT + + align:start position:0% +is in DT probably the hardest part of CT + + + align:start position:0% +is in DT probably the hardest part of CT +and that involves thinking about what + + align:start position:0% +and that involves thinking about what + + + align:start position:0% +and that involves thinking about what +should be our basis + + align:start position:0% +should be our basis + + + align:start position:0% +should be our basis +signals in DT there was a really good + + align:start position:0% +signals in DT there was a really good + + + align:start position:0% +signals in DT there was a really good +candidate for that which we call the + + align:start position:0% +candidate for that which we call the + + + align:start position:0% +candidate for that which we call the +unit sample + + align:start position:0% +unit sample + + + align:start position:0% +unit sample +signal the unit sample signal is the + + align:start position:0% +signal the unit sample signal is the + + + align:start position:0% +signal the unit sample signal is the +simplest possible non-trivial DT signal + + align:start position:0% +simplest possible non-trivial DT signal + + + align:start position:0% +simplest possible non-trivial DT signal +by which I mean it is zero everywhere + + align:start position:0% +by which I mean it is zero everywhere + + + align:start position:0% +by which I mean it is zero everywhere +except one place if it were zero + + align:start position:0% +except one place if it were zero + + + align:start position:0% +except one place if it were zero +everywhere we would call it + + align:start position:0% + + + + align:start position:0% + +trivial so in order for it not to be + + align:start position:0% +trivial so in order for it not to be + + + align:start position:0% +trivial so in order for it not to be +trivial it has to be nonzero at least + + align:start position:0% +trivial it has to be nonzero at least + + + align:start position:0% +trivial it has to be nonzero at least +someplace the place is non-trivial is at + + align:start position:0% +someplace the place is non-trivial is at + + + align:start position:0% +someplace the place is non-trivial is at +n equal + + align:start position:0% +n equal + + + align:start position:0% +n equal +0 and the value that it is given that it + + align:start position:0% +0 and the value that it is given that it + + + align:start position:0% +0 and the value that it is given that it +can't be zero is one okay so the unit + + align:start position:0% +can't be zero is one okay so the unit + + + align:start position:0% +can't be zero is one okay so the unit +sample signal is the most simple + + align:start position:0% +sample signal is the most simple + + + align:start position:0% +sample signal is the most simple +non-trivial DT signal so what we need is + + align:start position:0% +non-trivial DT signal so what we need is + + + align:start position:0% +non-trivial DT signal so what we need is +the equivalent for + + align:start position:0% +the equivalent for + + + align:start position:0% +the equivalent for +CT so here it + + align:start position:0% +CT so here it + + + align:start position:0% +CT so here it +is Define a signal in + + align:start position:0% +is Define a signal in + + + align:start position:0% +is Define a signal in +CT that is zero everywhere except zero + + align:start position:0% +CT that is zero everywhere except zero + + + align:start position:0% +CT that is zero everywhere except zero +and that zero make it + + align:start position:0% + + + + align:start position:0% + +one so is that a good choice and I hope + + align:start position:0% +one so is that a good choice and I hope + + + align:start position:0% +one so is that a good choice and I hope +I've sort of biased my presentation + + align:start position:0% +I've sort of biased my presentation + + + align:start position:0% +I've sort of biased my presentation +enough so that the answer is + + align:start position:0% +enough so that the answer is + + + align:start position:0% +enough so that the answer is +obviously no so the real question is why + + align:start position:0% +obviously no so the real question is why + + + align:start position:0% +obviously no so the real question is why +not can somebody think of a good reason + + align:start position:0% +not can somebody think of a good reason + + + align:start position:0% +not can somebody think of a good reason +why this is a poor choice for a building + + align:start position:0% +why this is a poor choice for a building + + + align:start position:0% +why this is a poor choice for a building +block signal + + align:start position:0% + + + + align:start position:0% + +yes so you you would need infinite gain + + align:start position:0% +yes so you you would need infinite gain + + + align:start position:0% +yes so you you would need infinite gain +to go from zero to one that's sort of + + align:start position:0% +to go from zero to one that's sort of + + + align:start position:0% +to go from zero to one that's sort of +true for the r thing + + align:start position:0% +true for the r thing + + + align:start position:0% +true for the r thing +two right you have to go from 0 to + + align:start position:0% +two right you have to go from 0 to + + + align:start position:0% +two right you have to go from 0 to +one it's in zero time that seems hard + + align:start position:0% +one it's in zero time that seems hard + + + align:start position:0% +one it's in zero time that seems hard +any other ideas + + align:start position:0% +any other ideas + + + align:start position:0% +any other ideas +yeah not + + align:start position:0% +yeah not + + + align:start position:0% +yeah not +continuous uh that's also + + align:start position:0% +continuous uh that's also + + + align:start position:0% +continuous uh that's also +true + + align:start position:0% +true + + + align:start position:0% +true +yes the integral is always zero that's a + + align:start position:0% +yes the integral is always zero that's a + + + align:start position:0% +yes the integral is always zero that's a +problem so what kind of so it's not it's + + align:start position:0% +problem so what kind of so it's not it's + + + align:start position:0% +problem so what kind of so it's not it's +just not going to be a very useful + + align:start position:0% +just not going to be a very useful + + + align:start position:0% +just not going to be a very useful +signal okay what am I doing I'm trying + + align:start position:0% +signal okay what am I doing I'm trying + + + align:start position:0% +signal okay what am I doing I'm trying +to figure out a basis + + align:start position:0% +to figure out a basis + + + align:start position:0% +to figure out a basis +signal that I would use in Block + + align:start position:0% +signal that I would use in Block + + + align:start position:0% +signal that I would use in Block +diagrams my basic block diagram is this + + align:start position:0% +diagrams my basic block diagram is this + + + align:start position:0% +diagrams my basic block diagram is this +integrator + + align:start position:0% +integrator + + + align:start position:0% +integrator +thing minus infinity to T on + + align:start position:0% +thing minus infinity to T on + + + align:start position:0% +thing minus infinity to T on +to so I'd like to put something in here + + align:start position:0% +to so I'd like to put something in here + + + align:start position:0% +to so I'd like to put something in here +but if I put that signal what did I call + + align:start position:0% +but if I put that signal what did I call + + + align:start position:0% +but if I put that signal what did I call +it w if I put + + align:start position:0% +it w if I put + + + align:start position:0% +it w if I put +W into an integrator what's the output + + align:start position:0% +W into an integrator what's the output + + + align:start position:0% +W into an integrator what's the output +of the integrator after you integrate + + align:start position:0% +of the integrator after you integrate + + + align:start position:0% +of the integrator after you integrate +W zero well that's a problem it's not a + + align:start position:0% +W zero well that's a problem it's not a + + + align:start position:0% +W zero well that's a problem it's not a +very good basis function if the very + + align:start position:0% +very good basis function if the very + + + align:start position:0% +very good basis function if the very +first operator I go through turns it + + align:start position:0% +first operator I go through turns it + + + align:start position:0% +first operator I go through turns it +into + + align:start position:0% +into + + + align:start position:0% +into +zero everyone see that that's kind of a + + align:start position:0% +zero everyone see that that's kind of a + + + align:start position:0% +zero everyone see that that's kind of a +problem this is the problem in CT if you + + align:start position:0% +problem this is the problem in CT if you + + + align:start position:0% +problem this is the problem in CT if you +guys figure out the next slide you're + + align:start position:0% +guys figure out the next slide you're + + + align:start position:0% +guys figure out the next slide you're +done CT is easy so what we + + align:start position:0% +done CT is easy so what we + + + align:start position:0% +done CT is easy so what we +do is think about defining a + + align:start position:0% +do is think about defining a + + + align:start position:0% +do is think about defining a +signal that would have the property that + + align:start position:0% +signal that would have the property that + + + align:start position:0% +signal that would have the property that +it behaved as though it had those + + align:start position:0% +it behaved as though it had those + + + align:start position:0% +it behaved as though it had those +desirable properties what would have to + + align:start position:0% +desirable properties what would have to + + + align:start position:0% +desirable properties what would have to +happen we'd like a signal that had some + + align:start position:0% +happen we'd like a signal that had some + + + align:start position:0% +happen we'd like a signal that had some +amount of area because that's what this + + align:start position:0% +amount of area because that's what this + + + align:start position:0% +amount of area because that's what this +thing is this is an area + + align:start position:0% +thing is this is an area + + + align:start position:0% +thing is this is an area +operator we would like a signal that + + align:start position:0% +operator we would like a signal that + + + align:start position:0% +operator we would like a signal that +didn't have zero area the the W signal + + align:start position:0% +didn't have zero area the the W signal + + + align:start position:0% +didn't have zero area the the W signal +has zero area + + align:start position:0% +has zero area + + + align:start position:0% +has zero area +bad we'd like a signal that doesn't have + + align:start position:0% +bad we'd like a signal that doesn't have + + + align:start position:0% +bad we'd like a signal that doesn't have +zero area in fact if we wanted it to be + + align:start position:0% +zero area in fact if we wanted it to be + + + align:start position:0% +zero area in fact if we wanted it to be +kind of the simplest possible thing it + + align:start position:0% +kind of the simplest possible thing it + + + align:start position:0% +kind of the simplest possible thing it +should have an area of one right but + + align:start position:0% +should have an area of one right but + + + align:start position:0% +should have an area of one right but +we'd like it to be zero almost + + align:start position:0% +we'd like it to be zero almost + + + align:start position:0% +we'd like it to be zero almost +everywhere how do you do that + + align:start position:0% +everywhere how do you do that + + + align:start position:0% +everywhere how do you do that +okay well the way you can do it and the + + align:start position:0% +okay well the way you can do it and the + + + align:start position:0% +okay well the way you can do it and the +way we will do it is think about a + + align:start position:0% +way we will do it is think about a + + + align:start position:0% +way we will do it is think about a +building a signal in a + + align:start position:0% +building a signal in a + + + align:start position:0% +building a signal in a +limit what if I had a a pulse signal + + align:start position:0% +limit what if I had a a pulse signal + + + align:start position:0% +limit what if I had a a pulse signal +that was 2 Epsilon wide and 1 over 2 + + align:start position:0% +that was 2 Epsilon wide and 1 over 2 + + + align:start position:0% +that was 2 Epsilon wide and 1 over 2 +Epsilon High the area would be one + + align:start position:0% +Epsilon High the area would be one + + + align:start position:0% +Epsilon High the area would be one +regardless of the value of + + align:start position:0% +regardless of the value of + + + align:start position:0% +regardless of the value of +Epsilon and if I shrunk Epsilon to be a + + align:start position:0% +Epsilon and if I shrunk Epsilon to be a + + + align:start position:0% +Epsilon and if I shrunk Epsilon to be a +very small + + align:start position:0% +very small + + + align:start position:0% +very small +number say + + align:start position:0% +number say + + + align:start position:0% +number say +zero if I think about the limit as EPS + + align:start position:0% +zero if I think about the limit as EPS + + + align:start position:0% +zero if I think about the limit as EPS +get smaller small and smaller and + + align:start position:0% +get smaller small and smaller and + + + align:start position:0% +get smaller small and smaller and +smaller and smaller then I approach the + + align:start position:0% +smaller and smaller then I approach the + + + align:start position:0% +smaller and smaller then I approach the +condition I'd like to have the signal is + + align:start position:0% +condition I'd like to have the signal is + + + align:start position:0% +condition I'd like to have the signal is +zero everywhere except zero now it has a + + align:start position:0% +zero everywhere except zero now it has a + + + align:start position:0% +zero everywhere except zero now it has a +horrendous value at zero but oh well + + align:start position:0% +horrendous value at zero but oh well + + + align:start position:0% +horrendous value at zero but oh well +I'll sweep that under the rug the + + align:start position:0% +I'll sweep that under the rug the + + + align:start position:0% +I'll sweep that under the rug the +important thing is that when I integrate + + align:start position:0% +important thing is that when I integrate + + + align:start position:0% +important thing is that when I integrate +it I'd like it to give me one that's the + + align:start position:0% +it I'd like it to give me one that's the + + + align:start position:0% +it I'd like it to give me one that's the +important thing everyone with me that's + + align:start position:0% +important thing everyone with me that's + + + align:start position:0% +important thing everyone with me that's +the hardest part in this part of the + + align:start position:0% +the hardest part in this part of the + + + align:start position:0% +the hardest part in this part of the +course if you get this CT systems are a + + align:start position:0% +course if you get this CT systems are a + + + align:start position:0% +course if you get this CT systems are a +breeze so this is kind of a different + + align:start position:0% +breeze so this is kind of a different + + + align:start position:0% +breeze so this is kind of a different +kind of + + align:start position:0% +kind of + + + align:start position:0% +kind of +signal the idea is to incorporate in it + + align:start position:0% +signal the idea is to incorporate in it + + + align:start position:0% +signal the idea is to incorporate in it +two seemingly uh contradictory things it + + align:start position:0% +two seemingly uh contradictory things it + + + align:start position:0% +two seemingly uh contradictory things it +should be zero almost + + align:start position:0% +should be zero almost + + + align:start position:0% +should be zero almost +everywhere and the integral should be + + align:start position:0% +everywhere and the integral should be + + + align:start position:0% +everywhere and the integral should be +one so there is no such thing right this + + align:start position:0% +one so there is no such thing right this + + + align:start position:0% +one so there is no such thing right this +is an idealized signal this is something + + align:start position:0% +is an idealized signal this is something + + + align:start position:0% +is an idealized signal this is something +that we think about in the limit it + + align:start position:0% +that we think about in the limit it + + + align:start position:0% +that we think about in the limit it +turns out that we can get a lot of + + align:start position:0% +turns out that we can get a lot of + + + align:start position:0% +turns out that we can get a lot of +insight by thinking about this + + align:start position:0% +insight by thinking about this + + + align:start position:0% +insight by thinking about this +signal but it is important to realize + + align:start position:0% +signal but it is important to realize + + + align:start position:0% +signal but it is important to realize +that it only def is only defined in a + + align:start position:0% +that it only def is only defined in a + + + align:start position:0% +that it only def is only defined in a +limit so um we will write it since it's + + align:start position:0% +limit so um we will write it since it's + + + align:start position:0% +limit so um we will write it since it's +so useful we will write it this way + + align:start position:0% +so useful we will write it this way + + + align:start position:0% +so useful we will write it this way +we'll draw a little arrow the arrow is + + align:start position:0% +we'll draw a little arrow the arrow is + + + align:start position:0% +we'll draw a little arrow the arrow is +supposed to canote in your mind this + + align:start position:0% +supposed to canote in your mind this + + + align:start position:0% +supposed to canote in your mind this +thing goes really + + align:start position:0% +thing goes really + + + align:start position:0% +thing goes really +high it goes so high that telling you + + align:start position:0% +high it goes so high that telling you + + + align:start position:0% +high it goes so high that telling you +how high it is is meaningless so instead + + align:start position:0% +how high it is is meaningless so instead + + + align:start position:0% +how high it is is meaningless so instead +to the side we tell you what's the area + + align:start position:0% +to the side we tell you what's the area + + + align:start position:0% +to the side we tell you what's the area +of + + align:start position:0% +of + + + align:start position:0% +of +it what would come out if you integrated + + align:start position:0% +it what would come out if you integrated + + + align:start position:0% +it what would come out if you integrated +it yes for DT signal like decompose any + + align:start position:0% +it yes for DT signal like decompose any + + + align:start position:0% +it yes for DT signal like decompose any +DT signal into a series of can you do + + align:start position:0% +DT signal into a series of can you do + + + align:start position:0% +DT signal into a series of can you do +the same thing with yes and that will be + + align:start position:0% +the same thing with yes and that will be + + + align:start position:0% +the same thing with yes and that will be +something that we spend a lot of time on + + align:start position:0% +something that we spend a lot of time on + + + align:start position:0% +something that we spend a lot of time on +because that decomposition is not + + align:start position:0% +because that decomposition is not + + + align:start position:0% +because that decomposition is not +trivial but it is + + align:start position:0% +trivial but it is + + + align:start position:0% +trivial but it is +possible so the question was can we + + align:start position:0% +possible so the question was can we + + + align:start position:0% +possible so the question was can we +decompose arbitrary signals into sums of + + align:start position:0% +decompose arbitrary signals into sums of + + + align:start position:0% +decompose arbitrary signals into sums of +these things and the answer is + + align:start position:0% +these things and the answer is + + + align:start position:0% +these things and the answer is +absolutely + + align:start position:0% +absolutely + + + align:start position:0% +absolutely +yes that's why we like + + align:start position:0% +yes that's why we like + + + align:start position:0% +yes that's why we like +it + + align:start position:0% +it + + + align:start position:0% +it +okay uh so the first thing think about + + align:start position:0% +okay uh so the first thing think about + + + align:start position:0% +okay uh so the first thing think about +is what happens if you put now instead + + align:start position:0% +is what happens if you put now instead + + + align:start position:0% +is what happens if you put now instead +of + + align:start position:0% +of + + + align:start position:0% +of +w let's put Delta of + + align:start position:0% +w let's put Delta of + + + align:start position:0% +w let's put Delta of +T the unit impulse + + align:start position:0% +T the unit impulse + + + align:start position:0% +T the unit impulse +function what happens if you put the + + align:start position:0% +function what happens if you put the + + + align:start position:0% +function what happens if you put the +unit impulse function into an integrator + + align:start position:0% +unit impulse function into an integrator + + + align:start position:0% +unit impulse function into an integrator +well if you integrate the Delta of T so + + align:start position:0% +well if you integrate the Delta of T so + + + align:start position:0% +well if you integrate the Delta of T so +if my input X of T is Delta of T and if + + align:start position:0% +if my input X of T is Delta of T and if + + + align:start position:0% +if my input X of T is Delta of T and if +I want to think about y of T which is + + align:start position:0% +I want to think about y of T which is + + + align:start position:0% +I want to think about y of T which is +going to be a operating on x so think + + align:start position:0% +going to be a operating on x so think + + + align:start position:0% +going to be a operating on x so think +about what would be the answer to this + + align:start position:0% +about what would be the answer to this + + + align:start position:0% +about what would be the answer to this +integral for times less than zero well + + align:start position:0% +integral for times less than zero well + + + align:start position:0% +integral for times less than zero well +the system started at rest if the + + align:start position:0% +the system started at rest if the + + + align:start position:0% +the system started at rest if the +integrator turned on at + + align:start position:0% +integrator turned on at + + + align:start position:0% +integrator turned on at +zero What's the value of the answer of + + align:start position:0% +zero What's the value of the answer of + + + align:start position:0% +zero What's the value of the answer of +the integrator + + align:start position:0% +the integrator + + + align:start position:0% +the integrator +here zero it started at zero back at + + align:start position:0% +here zero it started at zero back at + + + align:start position:0% +here zero it started at zero back at +minus infinity sometime started at rest + + align:start position:0% +minus infinity sometime started at rest + + + align:start position:0% +minus infinity sometime started at rest +there was no + + align:start position:0% +there was no + + + align:start position:0% +there was no +input so the answer is zero so the + + align:start position:0% +input so the answer is zero so the + + + align:start position:0% +input so the answer is zero so the +answer is going to be zero up until + + align:start position:0% +answer is going to be zero up until + + + align:start position:0% +answer is going to be zero up until +something + + align:start position:0% +something + + + align:start position:0% +something +happens during that brief of + + align:start position:0% +happens during that brief of + + + align:start position:0% +happens during that brief of +time a unit of area went in so what's + + align:start position:0% +time a unit of area went in so what's + + + align:start position:0% +time a unit of area went in so what's +the output of the integrator + + align:start position:0% +the output of the integrator + + + align:start position:0% +the output of the integrator +become + + align:start position:0% +become + + + align:start position:0% +become +one so at that time it became + + align:start position:0% + + + + align:start position:0% + +one and then what's the value as you go + + align:start position:0% +one and then what's the value as you go + + + align:start position:0% +one and then what's the value as you go +forward in + + align:start position:0% +forward in + + + align:start position:0% +forward in +time one right it got stuck at one so + + align:start position:0% +time one right it got stuck at one so + + + align:start position:0% +time one right it got stuck at one so +the most primitive signal that we'll + + align:start position:0% +the most primitive signal that we'll + + + align:start position:0% +the most primitive signal that we'll +think about is the unit impulse function + + align:start position:0% +think about is the unit impulse function + + + align:start position:0% +think about is the unit impulse function +we'll denote that by Delta of t + + align:start position:0% +we'll denote that by Delta of t + + + align:start position:0% +we'll denote that by Delta of t +and it has the property that it goes + + align:start position:0% +and it has the property that it goes + + + align:start position:0% +and it has the property that it goes +through our most primitive + + align:start position:0% +through our most primitive + + + align:start position:0% +through our most primitive +block Delta goes to a unit step and the + + align:start position:0% +block Delta goes to a unit step and the + + + align:start position:0% +block Delta goes to a unit step and the +unit step is so useful that we'll give + + align:start position:0% +unit step is so useful that we'll give + + + align:start position:0% +unit step is so useful that we'll give +it a special name U of T U means unit + + align:start position:0% +it a special name U of T U means unit + + + align:start position:0% +it a special name U of T U means unit +step + + align:start position:0% +step + + + align:start position:0% +step +okay and with that all of these systems + + align:start position:0% +okay and with that all of these systems + + + align:start position:0% +okay and with that all of these systems +now make sense in the same sense that uh + + align:start position:0% +now make sense in the same sense that uh + + + align:start position:0% +now make sense in the same sense that uh +DT systems did so for example if I have + + align:start position:0% +DT systems did so for example if I have + + + align:start position:0% +DT systems did so for example if I have +a feed forward + + align:start position:0% +a feed forward + + + align:start position:0% +a feed forward +system I can think about that as having + + align:start position:0% +system I can think about that as having + + + align:start position:0% +system I can think about that as having +several signal flow paths going + + align:start position:0% +several signal flow paths going + + + align:start position:0% +several signal flow paths going +forward and the output of the signal + + align:start position:0% +forward and the output of the signal + + + align:start position:0% +forward and the output of the signal +when stimulated with a Delta + + align:start position:0% +when stimulated with a Delta + + + align:start position:0% +when stimulated with a Delta +function is the sum of all those + + align:start position:0% +function is the sum of all those + + + align:start position:0% +function is the sum of all those +different signal paths that I can think + + align:start position:0% +different signal paths that I can think + + + align:start position:0% +different signal paths that I can think +of so I can express the input output + + align:start position:0% +of so I can express the input output + + + align:start position:0% +of so I can express the input output +relationship by this functional + + align:start position:0% +relationship by this functional + + + align:start position:0% +relationship by this functional +relationship right everybody sees + + align:start position:0% +relationship right everybody sees + + + align:start position:0% +relationship right everybody sees +that or I can just think about all the + + align:start position:0% +that or I can just think about all the + + + align:start position:0% +that or I can just think about all the +different signal flow paths through here + + align:start position:0% +different signal flow paths through here + + + align:start position:0% +different signal flow paths through here +what would happen if I had a Delta + + align:start position:0% +what would happen if I had a Delta + + + align:start position:0% +what would happen if I had a Delta +function here well here's a signal flow + + align:start position:0% +function here well here's a signal flow + + + align:start position:0% +function here well here's a signal flow +path here's another one here's another + + align:start position:0% +path here's another one here's another + + + align:start position:0% +path here's another one here's another +one here's one four signal flow paths I + + align:start position:0% +one here's one four signal flow paths I + + + align:start position:0% +one here's one four signal flow paths I +have to think about four ways the input + + align:start position:0% +have to think about four ways the input + + + align:start position:0% +have to think about four ways the input +could turn into the output if the input + + align:start position:0% +could turn into the output if the input + + + align:start position:0% +could turn into the output if the input +went through the top path the output + + align:start position:0% +went through the top path the output + + + align:start position:0% +went through the top path the output +would + + align:start position:0% +would + + + align:start position:0% +would +be + + align:start position:0% +be + + + align:start position:0% +be +Delta if the input went through this + + align:start position:0% +Delta if the input went through this + + + align:start position:0% +Delta if the input went through this +path the output would + + align:start position:0% +path the output would + + + align:start position:0% +path the output would +be + + align:start position:0% +be + + + align:start position:0% +be +U if the if the input went through this + + align:start position:0% +U if the if the input went through this + + + align:start position:0% +U if the if the input went through this +path + + align:start position:0% +path + + + align:start position:0% +path +you if the input went through this it + + align:start position:0% +you if the input went through this it + + + align:start position:0% +you if the input went through this it +turns into U and then it goes through + + align:start position:0% +turns into U and then it goes through + + + align:start position:0% +turns into U and then it goes through +another accumulator what happens if you + + align:start position:0% +another accumulator what happens if you + + + align:start position:0% +another accumulator what happens if you +integrate + + align:start position:0% +integrate + + + align:start position:0% +integrate +u + + align:start position:0% +u + + + align:start position:0% +u +t right if this is + + align:start position:0% +t right if this is + + + align:start position:0% +t right if this is +U and if you put that into an into an + + align:start position:0% +U and if you put that into an into an + + + align:start position:0% +U and if you put that into an into an +integrator that integrator like all the + + align:start position:0% +integrator that integrator like all the + + + align:start position:0% +integrator that integrator like all the +other integrators that we'll talk about + + align:start position:0% +other integrators that we'll talk about + + + align:start position:0% +other integrators that we'll talk about +unless we tell you otherwise is + + align:start position:0% +unless we tell you otherwise is + + + align:start position:0% +unless we tell you otherwise is +initially at rest therefore the output + + align:start position:0% +initially at rest therefore the output + + + align:start position:0% +initially at rest therefore the output +started at + + align:start position:0% +started at + + + align:start position:0% +started at +zero because U is z for T less than Z it + + align:start position:0% +zero because U is z for T less than Z it + + + align:start position:0% +zero because U is z for T less than Z it +zero until something happens at T equals + + align:start position:0% +zero until something happens at T equals + + + align:start position:0% +zero until something happens at T equals +z at which point the input becomes one + + align:start position:0% +z at which point the input becomes one + + + align:start position:0% +z at which point the input becomes one +and the integral of one is + + align:start position:0% +and the integral of one is + + + align:start position:0% +and the integral of one is +T so we will usually write that this + + align:start position:0% +T so we will usually write that this + + + align:start position:0% +T so we will usually write that this +way meaning it's t so we we will write + + align:start position:0% +way meaning it's t so we we will write + + + align:start position:0% +way meaning it's t so we we will write +as a short hand times U that's kind of a + + align:start position:0% +as a short hand times U that's kind of a + + + align:start position:0% +as a short hand times U that's kind of a +strange strange thing to do it's just + + align:start position:0% +strange strange thing to do it's just + + + align:start position:0% +strange strange thing to do it's just +very + + align:start position:0% +very + + + align:start position:0% +very +convenient it's convenient because + + align:start position:0% +convenient it's convenient because + + + align:start position:0% +convenient it's convenient because +normally when you have a function so + + align:start position:0% +normally when you have a function so + + + align:start position:0% +normally when you have a function so +that last + + align:start position:0% +that last + + + align:start position:0% +that last +function this one is a signal + + align:start position:0% +function this one is a signal + + + align:start position:0% +function this one is a signal +that does + + align:start position:0% +that does + + + align:start position:0% +that does +this so we will call that Tu of T + + align:start position:0% +this so we will call that Tu of T + + + align:start position:0% +this so we will call that Tu of T +because obviously T is that signal we + + align:start position:0% +because obviously T is that signal we + + + align:start position:0% +because obviously T is that signal we +don't mean that right we want to Lop off + + align:start position:0% +don't mean that right we want to Lop off + + + align:start position:0% +don't mean that right we want to Lop off +the part that came before zero U of T + + align:start position:0% +the part that came before zero U of T + + + align:start position:0% +the part that came before zero U of T +multiplying by U of T is a quick way of + + align:start position:0% +multiplying by U of T is a quick way of + + + align:start position:0% +multiplying by U of T is a quick way of +writing Lop off the stuff that came + + align:start position:0% +writing Lop off the stuff that came + + + align:start position:0% +writing Lop off the stuff that came +before + + align:start position:0% +before + + + align:start position:0% +before +zero that's all that means so we'll + + align:start position:0% +zero that's all that means so we'll + + + align:start position:0% +zero that's all that means so we'll +we'll write that that way and you can + + align:start position:0% +we'll write that that way and you can + + + align:start position:0% +we'll write that that way and you can +see that by thinking about signal flow + + align:start position:0% +see that by thinking about signal flow + + + align:start position:0% +see that by thinking about signal flow +path and by thinking about how this + + align:start position:0% +path and by thinking about how this + + + align:start position:0% +path and by thinking about how this +basic signal this basis function goes + + align:start position:0% +basic signal this basis function goes + + + align:start position:0% +basic signal this basis function goes +through the system it's easy to figure + + align:start position:0% +through the system it's easy to figure + + + align:start position:0% +through the system it's easy to figure +out U the the response of such a + + align:start position:0% + + + + align:start position:0% + +system just like in DP feedback is + + align:start position:0% +system just like in DP feedback is + + + align:start position:0% +system just like in DP feedback is +different so now we have to think about + + align:start position:0% +different so now we have to think about + + + align:start position:0% +different so now we have to think about +what would happen if there's a feedback + + align:start position:0% +what would happen if there's a feedback + + + align:start position:0% +what would happen if there's a feedback +loop so it was crucial when I was doing + + align:start position:0% +loop so it was crucial when I was doing + + + align:start position:0% +loop so it was crucial when I was doing +this kind of an illustration that it was + + align:start position:0% +this kind of an illustration that it was + + + align:start position:0% +this kind of an illustration that it was +feed forward + + align:start position:0% +feed forward + + + align:start position:0% +feed forward +only I could I could I could decompose + + align:start position:0% +only I could I could I could decompose + + + align:start position:0% +only I could I could I could decompose +all of the signal flow paths into a + + align:start position:0% +all of the signal flow paths into a + + + align:start position:0% +all of the signal flow paths into a +finite number of forward goinging paths + + align:start position:0% +finite number of forward goinging paths + + + align:start position:0% +finite number of forward goinging paths +this is + + align:start position:0% + + + + align:start position:0% + +harder so this happened in dt2 we had to + + align:start position:0% +harder so this happened in dt2 we had to + + + align:start position:0% +harder so this happened in dt2 we had to +figure out how the DT system was going + + align:start position:0% +figure out how the DT system was going + + + align:start position:0% +figure out how the DT system was going +to work when we had a feedback path and + + align:start position:0% +to work when we had a feedback path and + + + align:start position:0% +to work when we had a feedback path and +it was more complicated and we had to + + align:start position:0% +it was more complicated and we had to + + + align:start position:0% +it was more complicated and we had to +fall back on thinking about sample by + + align:start position:0% +fall back on thinking about sample by + + + align:start position:0% +fall back on thinking about sample by +sample propagation of the signal through + + align:start position:0% +sample propagation of the signal through + + + align:start position:0% +sample propagation of the signal through +the system and we'll do the same thing + + align:start position:0% +the system and we'll do the same thing + + + align:start position:0% +the system and we'll do the same thing +here in order to figure out how to think + + align:start position:0% +here in order to figure out how to think + + + align:start position:0% +here in order to figure out how to think +about signal flow through such a + + align:start position:0% +about signal flow through such a + + + align:start position:0% +about signal flow through such a +diagram through a diagram that has + + align:start position:0% +diagram through a diagram that has + + + align:start position:0% +diagram through a diagram that has +feedback + + align:start position:0% +feedback + + + align:start position:0% +feedback +we'll think about falling back to 1803 + + align:start position:0% +we'll think about falling back to 1803 + + + align:start position:0% +we'll think about falling back to 1803 +right something we can trust something + + align:start position:0% +right something we can trust something + + + align:start position:0% +right something we can trust something +we all loved right nod nod your heads + + align:start position:0% +we all loved right nod nod your heads + + + align:start position:0% +we all loved right nod nod your heads +yes make me this reassures me right fond + + align:start position:0% +yes make me this reassures me right fond + + + align:start position:0% +yes make me this reassures me right fond +memories of 1803 right so it's pretty + + align:start position:0% +memories of 1803 right so it's pretty + + + align:start position:0% +memories of 1803 right so it's pretty +simple to think about how you would + + align:start position:0% +simple to think about how you would + + + align:start position:0% +simple to think about how you would +solve that system by using an 1803 type + + align:start position:0% +solve that system by using an 1803 type + + + align:start position:0% +solve that system by using an 1803 type +approach convert the system into a + + align:start position:0% +approach convert the system into a + + + align:start position:0% +approach convert the system into a +differential equation we've already done + + align:start position:0% +differential equation we've already done + + + align:start position:0% +differential equation we've already done +that + + align:start position:0% + + + + align:start position:0% + +one then from the form well we will + + align:start position:0% +one then from the form well we will + + + align:start position:0% +one then from the form well we will +usually in this class use the uh method + + align:start position:0% +usually in this class use the uh method + + + align:start position:0% +usually in this class use the uh method +the general method of solving + + align:start position:0% +the general method of solving + + + align:start position:0% +the general method of solving +differential equations which + + align:start position:0% +differential equations which + + + align:start position:0% +differential equations which +is what's the general method for solving + + align:start position:0% +is what's the general method for solving + + + align:start position:0% +is what's the general method for solving +differential + + align:start position:0% +differential + + + align:start position:0% +differential +equations they may not have told you in + + align:start position:0% +equations they may not have told you in + + + align:start position:0% +equations they may not have told you in +1803 what's the what's the general + + align:start position:0% +1803 what's the what's the general + + + align:start position:0% +1803 what's the what's the general +method of solving differential + + align:start position:0% +method of solving differential + + + align:start position:0% +method of solving differential +equations guess yes so the general + + align:start position:0% +equations guess yes so the general + + + align:start position:0% +equations guess yes so the general +method is + + align:start position:0% +method is + + + align:start position:0% +method is +guess if you can guess plug it in and it + + align:start position:0% +guess if you can guess plug it in and it + + + align:start position:0% +guess if you can guess plug it in and it +works you're + + align:start position:0% +works you're + + + align:start position:0% +works you're +done the kinds of systems that we will + + align:start position:0% +done the kinds of systems that we will + + + align:start position:0% +done the kinds of systems that we will +look at will be linear systems they will + + align:start position:0% +look at will be linear systems they will + + + align:start position:0% +look at will be linear systems they will +have a single unique solution if you can + + align:start position:0% +have a single unique solution if you can + + + align:start position:0% +have a single unique solution if you can +find it by guessing you're done and we + + align:start position:0% +find it by guessing you're done and we + + + align:start position:0% +find it by guessing you're done and we +will prove later in the course that all + + align:start position:0% +will prove later in the course that all + + + align:start position:0% +will prove later in the course that all +systems of this class where I haven't + + align:start position:0% +systems of this class where I haven't + + + align:start position:0% +systems of this class where I haven't +really defined what this class is but if + + align:start position:0% +really defined what this class is but if + + + align:start position:0% +really defined what this class is but if +you made a system out of adders gains + + align:start position:0% +you made a system out of adders gains + + + align:start position:0% +you made a system out of adders gains +and + + align:start position:0% +and + + + align:start position:0% +and +integrators and only those + + align:start position:0% +integrators and only those + + + align:start position:0% +integrators and only those +parts then that system will always be + + align:start position:0% +parts then that system will always be + + + align:start position:0% +parts then that system will always be +linear and the solutions can always be + + align:start position:0% +linear and the solutions can always be + + + align:start position:0% +linear and the solutions can always be +written as complex exponentials + + align:start position:0% +written as complex exponentials + + + align:start position:0% +written as complex exponentials +we'll prove that later I'm not going to + + align:start position:0% +we'll prove that later I'm not going to + + + align:start position:0% +we'll prove that later I'm not going to +bother with it now for now you would say + + align:start position:0% +bother with it now for now you would say + + + align:start position:0% +bother with it now for now you would say +Okay first order linear differential + + align:start position:0% +Okay first order linear differential + + + align:start position:0% +Okay first order linear differential +equation with constant coefficiency + + align:start position:0% +equation with constant coefficiency + + + align:start position:0% +equation with constant coefficiency +obvious the answer is obviously an + + align:start position:0% +obvious the answer is obviously an + + + align:start position:0% +obvious the answer is obviously an +exponential + + align:start position:0% +exponential + + + align:start position:0% +exponential +function so you plug that into the + + align:start position:0% +function so you plug that into the + + + align:start position:0% +function so you plug that into the +differential equation you figure out the + + align:start position:0% +differential equation you figure out the + + + align:start position:0% +differential equation you figure out the +constraints that would have to be uh + + align:start position:0% +constraints that would have to be uh + + + align:start position:0% +constraints that would have to be uh +solved for this to be true and the + + align:start position:0% +solved for this to be true and the + + + align:start position:0% +solved for this to be true and the +answer is that y should be e to the PT U + + align:start position:0% +answer is that y should be e to the PT U + + + align:start position:0% +answer is that y should be e to the PT U +of T should start at + + align:start position:0% +of T should start at + + + align:start position:0% +of T should start at +zero and there it should be an + + align:start position:0% +zero and there it should be an + + + align:start position:0% +zero and there it should be an +exponential after that and the P shows + + align:start position:0% +exponential after that and the P shows + + + align:start position:0% +exponential after that and the P shows +up as the exponent in the + + align:start position:0% +up as the exponent in the + + + align:start position:0% +up as the exponent in the +exponential okay what we'd like to do is + + align:start position:0% +exponential okay what we'd like to do is + + + align:start position:0% +exponential okay what we'd like to do is +develop an alternative way of thinking + + align:start position:0% +develop an alternative way of thinking + + + align:start position:0% +develop an alternative way of thinking +about that using the operator + + align:start position:0% + + + + align:start position:0% + +approach so a completely different way + + align:start position:0% +approach so a completely different way + + + align:start position:0% +approach so a completely different way +to solve that problem would be to think + + align:start position:0% +to solve that problem would be to think + + + align:start position:0% +to solve that problem would be to think +about write an operator expression for + + align:start position:0% +about write an operator expression for + + + align:start position:0% +about write an operator expression for +this okay so Y is a times the signal + + align:start position:0% +this okay so Y is a times the signal + + + align:start position:0% +this okay so Y is a times the signal +that results when you add X to + + align:start position:0% + + + + align:start position:0% + +py + + align:start position:0% +py + + + align:start position:0% +py +solve for the ratio Y byx and you get an + + align:start position:0% +solve for the ratio Y byx and you get an + + + align:start position:0% +solve for the ratio Y byx and you get an +operator expression a over 1 minus + + align:start position:0% + + + + align:start position:0% + +PA just like in DT we have to figure out + + align:start position:0% +PA just like in DT we have to figure out + + + align:start position:0% +PA just like in DT we have to figure out +how we would think about + + align:start position:0% +how we would think about + + + align:start position:0% +how we would think about +that it's an implicit operation right + + align:start position:0% +that it's an implicit operation right + + + align:start position:0% +that it's an implicit operation right +it's telling me that if I knew the + + align:start position:0% +it's telling me that if I knew the + + + align:start position:0% +it's telling me that if I knew the +answer the answer is the signal that + + align:start position:0% +answer the answer is the signal that + + + align:start position:0% +answer the answer is the signal that +when operated on by one minus p is the + + align:start position:0% +when operated on by one minus p is the + + + align:start position:0% +when operated on by one minus p is the +input is the integral of the input but I + + align:start position:0% +input is the integral of the input but I + + + align:start position:0% +input is the integral of the input but I +don't know the answer so that reasoning + + align:start position:0% +don't know the answer so that reasoning + + + align:start position:0% +don't know the answer so that reasoning +doesn't quite work the reasoning that I + + align:start position:0% +doesn't quite work the reasoning that I + + + align:start position:0% +doesn't quite work the reasoning that I +used to solve the feed forward question + + align:start position:0% +used to solve the feed forward question + + + align:start position:0% +used to solve the feed forward question +doesn't quite work so I have to think of + + align:start position:0% +doesn't quite work so I have to think of + + + align:start position:0% +doesn't quite work so I have to think of +a different way of doing it just like we + + align:start position:0% +a different way of doing it just like we + + + align:start position:0% +a different way of doing it just like we +did in + + align:start position:0% +did in + + + align:start position:0% +did in +DT and the same solution works not + + align:start position:0% +DT and the same solution works not + + + align:start position:0% +DT and the same solution works not +surprisingly right a behaves like a + + align:start position:0% +surprisingly right a behaves like a + + + align:start position:0% +surprisingly right a behaves like a +polinomial r behaves like a polom after + + align:start position:0% +polinomial r behaves like a polom after + + + align:start position:0% +polinomial r behaves like a polom after +you turn it into a + + align:start position:0% +you turn it into a + + + align:start position:0% +you turn it into a +polinomial you can't tell if you started + + align:start position:0% +polinomial you can't tell if you started + + + align:start position:0% +polinomial you can't tell if you started +with a or R it's a + + align:start position:0% +with a or R it's a + + + align:start position:0% +with a or R it's a +polom so for that reason exactly the + + align:start position:0% +polom so for that reason exactly the + + + align:start position:0% +polom so for that reason exactly the +same stuff that you didn't in DT works + + align:start position:0% +same stuff that you didn't in DT works + + + align:start position:0% +same stuff that you didn't in DT works +that's why we can solve everything in 50 + + align:start position:0% +that's why we can solve everything in 50 + + + align:start position:0% +that's why we can solve everything in 50 +minutes it's all the + + align:start position:0% +minutes it's all the + + + align:start position:0% +minutes it's all the +same so in DT we thought about this as + + align:start position:0% +same so in DT we thought about this as + + + align:start position:0% +same so in DT we thought about this as +being a + + align:start position:0% +being a + + + align:start position:0% +being a +series you could figure out an ascending + + align:start position:0% +series you could figure out an ascending + + + align:start position:0% +series you could figure out an ascending +series a power series that's equivalent + + align:start position:0% +series a power series that's equivalent + + + align:start position:0% +series a power series that's equivalent +by thinking about something like + + align:start position:0% +by thinking about something like + + + align:start position:0% +by thinking about something like +synthetic division tailor series + + align:start position:0% +synthetic division tailor series + + + align:start position:0% +synthetic division tailor series +whatever you're comfortable with but + + align:start position:0% +whatever you're comfortable with but + + + align:start position:0% +whatever you're comfortable with but +whatever you're comfortable with this a + + align:start position:0% +whatever you're comfortable with this a + + + align:start position:0% +whatever you're comfortable with this a +over 1 minus PA Take the A out front + + align:start position:0% +over 1 minus PA Take the A out front + + + align:start position:0% +over 1 minus PA Take the A out front +then you're left with 1 over 1us + + align:start position:0% +then you're left with 1 over 1us + + + align:start position:0% +then you're left with 1 over 1us +PA you think about that as a tailor + + align:start position:0% +PA you think about that as a tailor + + + align:start position:0% +PA you think about that as a tailor +series that's 1 + PA a plus p s a s plus + + align:start position:0% +series that's 1 + PA a plus p s a s plus + + + align:start position:0% +series that's 1 + PA a plus p s a s plus +PB a cub Etc + + align:start position:0% + + + + align:start position:0% + +done okay now I know what the system + + align:start position:0% +done okay now I know what the system + + + align:start position:0% +done okay now I know what the system +functional looks like now I've got a + + align:start position:0% +functional looks like now I've got a + + + align:start position:0% +functional looks like now I've got a +feed forward system so I can use the + + align:start position:0% +feed forward system so I can use the + + + align:start position:0% +feed forward system so I can use the +technique from the other side what + + align:start position:0% +technique from the other side what + + + align:start position:0% +technique from the other side what +happens if you put Delta into a system + + align:start position:0% +happens if you put Delta into a system + + + align:start position:0% +happens if you put Delta into a system +whose um functional representation is + + align:start position:0% + + + + align:start position:0% + +a you get a so you get a u let me skip + + align:start position:0% +a you get a so you get a u let me skip + + + align:start position:0% +a you get a so you get a u let me skip +that one that's on the next p slide uh + + align:start position:0% +that one that's on the next p slide uh + + + align:start position:0% +that one that's on the next p slide uh +what happens if you put um uh so what if + + align:start position:0% +what happens if you put um uh so what if + + + align:start position:0% +what happens if you put um uh so what if +what happens if you put in a no that's + + align:start position:0% +what happens if you put in a no that's + + + align:start position:0% +what happens if you put in a no that's +right I did that right okay one U sorry + + align:start position:0% +right I did that right okay one U sorry + + + align:start position:0% +right I did that right okay one U sorry +I'm confusing + + align:start position:0% +I'm confusing + + + align:start position:0% +I'm confusing +myself this a turned into that + + align:start position:0% +myself this a turned into that + + + align:start position:0% +myself this a turned into that +U right what happens if you put it into + + align:start position:0% +U right what happens if you put it into + + + align:start position:0% +U right what happens if you put it into +PA a + + align:start position:0% +PA a + + + align:start position:0% +PA a +s well the first so the first a turned + + align:start position:0% +s well the first so the first a turned + + + align:start position:0% +s well the first so the first a turned +Delta into U the second a turns Delta + + align:start position:0% +Delta into U the second a turns Delta + + + align:start position:0% +Delta into U the second a turns Delta +turns U into + + align:start position:0% +turns U into + + + align:start position:0% +turns U into +Tu and so I get this term so the PA a s + + align:start position:0% +Tu and so I get this term so the PA a s + + + align:start position:0% +Tu and so I get this term so the PA a s +turns into + + align:start position:0% +turns into + + + align:start position:0% +turns into +PTU the p^ 2 a cubed turns into half p^2 + + align:start position:0% +PTU the p^ 2 a cubed turns into half p^2 + + + align:start position:0% +PTU the p^ 2 a cubed turns into half p^2 +t^2 U + + align:start position:0% +t^2 U + + + align:start position:0% +t^2 U +Etc so what I've done is I've thought of + + align:start position:0% +Etc so what I've done is I've thought of + + + align:start position:0% +Etc so what I've done is I've thought of +a way of constructing this output signal + + align:start position:0% +a way of constructing this output signal + + + align:start position:0% +a way of constructing this output signal +from the input signal without ever using + + align:start position:0% + + + + align:start position:0% + +calculus okay I started with a solution + + align:start position:0% +calculus okay I started with a solution + + + align:start position:0% +calculus okay I started with a solution +based on 1803 that's strictly + + align:start position:0% +based on 1803 that's strictly + + + align:start position:0% +based on 1803 that's strictly +calculus I just redid the whole problem + + align:start position:0% +calculus I just redid the whole problem + + + align:start position:0% +calculus I just redid the whole problem +and didn't use any + + align:start position:0% +and didn't use any + + + align:start position:0% +and didn't use any +calculus and I and the method works just + + align:start position:0% +calculus and I and the method works just + + + align:start position:0% +calculus and I and the method works just +the same reason that the r method + + align:start position:0% +the same reason that the r method + + + align:start position:0% +the same reason that the r method +worked in the r method when we were + + align:start position:0% +worked in the r method when we were + + + align:start position:0% +worked in the r method when we were +thinking about the simple feedback with + + align:start position:0% +thinking about the simple feedback with + + + align:start position:0% +thinking about the simple feedback with +an our system system every loop around + + align:start position:0% +an our system system every loop around + + + align:start position:0% +an our system system every loop around +the feedback loop generated one new + + align:start position:0% +the feedback loop generated one new + + + align:start position:0% +the feedback loop generated one new +sample here every loop around the CT + + align:start position:0% +sample here every loop around the CT + + + align:start position:0% +sample here every loop around the CT +Loop generates one more contribution to + + align:start position:0% +Loop generates one more contribution to + + + align:start position:0% +Loop generates one more contribution to +the output you put uh a Delta function + + align:start position:0% +the output you put uh a Delta function + + + align:start position:0% +the output you put uh a Delta function +in it gets integrated once and you get a + + align:start position:0% +in it gets integrated once and you get a + + + align:start position:0% +in it gets integrated once and you get a +u function + + align:start position:0% +u function + + + align:start position:0% +u function +out so first in in the symbolic + + align:start position:0% +out so first in in the symbolic + + + align:start position:0% +out so first in in the symbolic +representation so the first thing that + + align:start position:0% +representation so the first thing that + + + align:start position:0% +representation so the first thing that +comes out is uh a times the + + align:start position:0% +comes out is uh a times the + + + align:start position:0% +comes out is uh a times the +input second thing that comes out is a + + align:start position:0% +input second thing that comes out is a + + + align:start position:0% +input second thing that comes out is a +squ p times the input third thing that + + align:start position:0% +squ p times the input third thing that + + + align:start position:0% +squ p times the input third thing that +comes out + + align:start position:0% +comes out + + + align:start position:0% +comes out +uh p^2 a cubed Etc every time you go + + align:start position:0% +uh p^2 a cubed Etc every time you go + + + align:start position:0% +uh p^2 a cubed Etc every time you go +through the loop you pick up one more + + align:start position:0% +through the loop you pick up one more + + + align:start position:0% +through the loop you pick up one more +term now think about it in the time + + align:start position:0% +term now think about it in the time + + + align:start position:0% +term now think about it in the time +domain you put in a Delta function the + + align:start position:0% +domain you put in a Delta function the + + + align:start position:0% +domain you put in a Delta function the +first thing that comes out is a + + align:start position:0% + + + + align:start position:0% + +step the second thing that comes + + align:start position:0% +step the second thing that comes + + + align:start position:0% +step the second thing that comes +out and gets added to the first thing + + align:start position:0% +out and gets added to the first thing + + + align:start position:0% +out and gets added to the first thing +that comes + + align:start position:0% +that comes + + + align:start position:0% +that comes +out is integrate multiply by P and + + align:start position:0% +out is integrate multiply by P and + + + align:start position:0% +out is integrate multiply by P and +integrate again + + align:start position:0% + + + + align:start position:0% + +so that's this term P * + + align:start position:0% +so that's this term P * + + + align:start position:0% +so that's this term P * +T so we get the unit step from the first + + align:start position:0% +T so we get the unit step from the first + + + align:start position:0% +T so we get the unit step from the first +term which looks like this we get the + + align:start position:0% +term which looks like this we get the + + + align:start position:0% +term which looks like this we get the +linear increase from the second term we + + align:start position:0% +linear increase from the second term we + + + align:start position:0% +linear increase from the second term we +get a squared term we get a cube + + align:start position:0% +get a squared term we get a cube + + + align:start position:0% +get a squared term we get a cube +term and + + align:start position:0% +term and + + + align:start position:0% +term and +voila we get the series expansion for e + + align:start position:0% +voila we get the series expansion for e + + + align:start position:0% +voila we get the series expansion for e +to the + + align:start position:0% +to the + + + align:start position:0% +to the +PT no calculus right it's purely + + align:start position:0% +PT no calculus right it's purely + + + align:start position:0% +PT no calculus right it's purely +thinking about how you would think about + + align:start position:0% +thinking about how you would think about + + + align:start position:0% +thinking about how you would think about +constructing the system con constructing + + align:start position:0% +constructing the system con constructing + + + align:start position:0% +constructing the system con constructing +the system by u a series representation + + align:start position:0% +the system by u a series representation + + + align:start position:0% +the system by u a series representation +for spinning around the feedback + + align:start position:0% +for spinning around the feedback + + + align:start position:0% +for spinning around the feedback +loop okay so that's an Insight that + + align:start position:0% +loop okay so that's an Insight that + + + align:start position:0% +loop okay so that's an Insight that +comes from thinking about um the system + + align:start position:0% +comes from thinking about um the system + + + align:start position:0% +comes from thinking about um the system +as a um functional representation as a + + align:start position:0% +as a um functional representation as a + + + align:start position:0% +as a um functional representation as a +polom pols can be expanded in tailor + + align:start position:0% +polom pols can be expanded in tailor + + + align:start position:0% +polom pols can be expanded in tailor +series therefore systems can be expanded + + align:start position:0% +series therefore systems can be expanded + + + align:start position:0% +series therefore systems can be expanded +in tailor + + align:start position:0% +in tailor + + + align:start position:0% +in tailor +series if you change the sign of + + align:start position:0% +series if you change the sign of + + + align:start position:0% +series if you change the sign of +P you notice that that previous example + + align:start position:0% +P you notice that that previous example + + + align:start position:0% +P you notice that that previous example +exploded right so we got an increasing + + align:start position:0% +exploded right so we got an increasing + + + align:start position:0% +exploded right so we got an increasing +exponential if you change the sign of p + + align:start position:0% +exponential if you change the sign of p + + + align:start position:0% +exponential if you change the sign of p +is not too surprising that what will + + align:start position:0% +is not too surprising that what will + + + align:start position:0% +is not too surprising that what will +happen is that it will + + align:start position:0% +happen is that it will + + + align:start position:0% +happen is that it will +converge so here symbolically the first + + align:start position:0% +converge so here symbolically the first + + + align:start position:0% +converge so here symbolically the first +signal is a unit step just like + + align:start position:0% +signal is a unit step just like + + + align:start position:0% +signal is a unit step just like +before but now because of the minus sign + + align:start position:0% +before but now because of the minus sign + + + align:start position:0% +before but now because of the minus sign +there's a negative on this PT so you get + + align:start position:0% +there's a negative on this PT so you get + + + align:start position:0% +there's a negative on this PT so you get +sloping + + align:start position:0% + + + + align:start position:0% + +downward in the Square term it's still + + align:start position:0% +downward in the Square term it's still + + + align:start position:0% +downward in the Square term it's still +positive so that breaks up + + align:start position:0% +positive so that breaks up + + + align:start position:0% +positive so that breaks up +up but the cubic is now downward + + align:start position:0% +up but the cubic is now downward + + + align:start position:0% +up but the cubic is now downward +again and you add an infinite number of + + align:start position:0% +again and you add an infinite number of + + + align:start position:0% +again and you add an infinite number of +those and you get another exponential + + align:start position:0% +those and you get another exponential + + + align:start position:0% +those and you get another exponential +this time a convergent + + align:start position:0% +this time a convergent + + + align:start position:0% +this time a convergent +one so the point is that it works + + align:start position:0% +one so the point is that it works + + + align:start position:0% +one so the point is that it works +extremely like the way the DT stuff did + + align:start position:0% +extremely like the way the DT stuff did + + + align:start position:0% +extremely like the way the DT stuff did +except now the basis functions are + + align:start position:0% +except now the basis functions are + + + align:start position:0% +except now the basis functions are +different the basis functions are + + align:start position:0% +different the basis functions are + + + align:start position:0% +different the basis functions are +derived from this thing which is the + + align:start position:0% +derived from this thing which is the + + + align:start position:0% +derived from this thing which is the +unit impulse + + align:start position:0% +unit impulse + + + align:start position:0% +unit impulse +function and the things that come out of + + align:start position:0% +function and the things that come out of + + + align:start position:0% +function and the things that come out of +the integrator are steps and ramps and + + align:start position:0% +the integrator are steps and ramps and + + + align:start position:0% +the integrator are steps and ramps and +Par parabas and stuff like + + align:start position:0% +Par parabas and stuff like + + + align:start position:0% +Par parabas and stuff like +that so in R the basic input signal was + + align:start position:0% +that so in R the basic input signal was + + + align:start position:0% +that so in R the basic input signal was +the um unit sample + + align:start position:0% +the um unit sample + + + align:start position:0% +the um unit sample +signal and what came out on each uh + + align:start position:0% +signal and what came out on each uh + + + align:start position:0% +signal and what came out on each uh +revolution around um uh for each cycle + + align:start position:0% +revolution around um uh for each cycle + + + align:start position:0% +revolution around um uh for each cycle +in a feedback system what came out was a + + align:start position:0% +in a feedback system what came out was a + + + align:start position:0% +in a feedback system what came out was a +successive delay here we get a + + align:start position:0% +successive delay here we get a + + + align:start position:0% +successive delay here we get a +successive + + align:start position:0% +successive + + + align:start position:0% +successive +integration okay delay was the + + align:start position:0% +integration okay delay was the + + + align:start position:0% +integration okay delay was the +fundamental operator integration is the + + align:start position:0% +fundamental operator integration is the + + + align:start position:0% +fundamental operator integration is the +fundamental operator successive delays + + align:start position:0% +fundamental operator successive delays + + + align:start position:0% +fundamental operator successive delays +successive + + align:start position:0% +successive + + + align:start position:0% +successive +Integrations and we get the idea that we + + align:start position:0% +Integrations and we get the idea that we + + + align:start position:0% +Integrations and we get the idea that we +have convergence and Divergence just + + align:start position:0% +have convergence and Divergence just + + + align:start position:0% +have convergence and Divergence just +like we did in DT except now the shapes + + align:start position:0% +like we did in DT except now the shapes + + + align:start position:0% +like we did in DT except now the shapes +of the regions are + + align:start position:0% + + + + align:start position:0% + +different so if the P which we will + + align:start position:0% +different so if the P which we will + + + align:start position:0% +different so if the P which we will +later call the + + align:start position:0% +later call the + + + align:start position:0% +later call the +pole by complete analogy to what we did + + align:start position:0% +pole by complete analogy to what we did + + + align:start position:0% +pole by complete analogy to what we did +in DT if the pole is in the right half + + align:start position:0% +in DT if the pole is in the right half + + + align:start position:0% +in DT if the pole is in the right half +plane then the systems response is + + align:start position:0% +plane then the systems response is + + + align:start position:0% +plane then the systems response is +Divergent if the pole is in the left + + align:start position:0% +Divergent if the pole is in the left + + + align:start position:0% +Divergent if the pole is in the left +half plane the system's response is + + align:start position:0% +half plane the system's response is + + + align:start position:0% +half plane the system's response is +convergent + + align:start position:0% +convergent + + + align:start position:0% +convergent +so it looks just like DT we think about + + align:start position:0% +so it looks just like DT we think about + + + align:start position:0% +so it looks just like DT we think about +this as signal flow pass we think about + + align:start position:0% +this as signal flow pass we think about + + + align:start position:0% +this as signal flow pass we think about +how feedback gives rise to an infinite + + align:start position:0% +how feedback gives rise to an infinite + + + align:start position:0% +how feedback gives rise to an infinite +number of + + align:start position:0% +number of + + + align:start position:0% +number of +those in DT each time through it gave + + align:start position:0% +those in DT each time through it gave + + + align:start position:0% +those in DT each time through it gave +one unit of delay in CT it gave um one + + align:start position:0% +one unit of delay in CT it gave um one + + + align:start position:0% +one unit of delay in CT it gave um one +unit of + + align:start position:0% +unit of + + + align:start position:0% +unit of +integration the method is the same the + + align:start position:0% +integration the method is the same the + + + align:start position:0% +integration the method is the same the +answer is + + align:start position:0% +answer is + + + align:start position:0% +answer is +different so what we got is tremendous + + align:start position:0% +different so what we got is tremendous + + + align:start position:0% +different so what we got is tremendous +similarities differential equation + + align:start position:0% +similarities differential equation + + + align:start position:0% +similarities differential equation +compared to difference equation block + + align:start position:0% +compared to difference equation block + + + align:start position:0% +compared to difference equation block +diagram compared to block diagram + + align:start position:0% +diagram compared to block diagram + + + align:start position:0% +diagram compared to block diagram +integrators instead of + + align:start position:0% +integrators instead of + + + align:start position:0% +integrators instead of +delays functional functional A's instead + + align:start position:0% +delays functional functional A's instead + + + align:start position:0% +delays functional functional A's instead +of + + align:start position:0% +of + + + align:start position:0% +of +RS pole + + align:start position:0% + + + + align:start position:0% + +pole mode mode fundamental + + align:start position:0% +pole mode mode fundamental + + + align:start position:0% +pole mode mode fundamental +mode here the fundamental mode was a a + + align:start position:0% +mode here the fundamental mode was a a + + + align:start position:0% +mode here the fundamental mode was a a +geometric sequence here it's an + + align:start position:0% +geometric sequence here it's an + + + align:start position:0% +geometric sequence here it's an +exponential function of time and we got + + align:start position:0% +exponential function of time and we got + + + align:start position:0% +exponential function of time and we got +different kinds of regional convergence + + align:start position:0% +different kinds of regional convergence + + + align:start position:0% +different kinds of regional convergence +signal converges for for poles and left + + align:start position:0% +signal converges for for poles and left + + + align:start position:0% +signal converges for for poles and left +half + + align:start position:0% +half + + + align:start position:0% +half +plane signals converge for poles inside + + align:start position:0% +plane signals converge for poles inside + + + align:start position:0% +plane signals converge for poles inside +the unit + + align:start position:0% +the unit + + + align:start position:0% +the unit +circle same + + align:start position:0% +circle same + + + align:start position:0% +circle same +idea but some + + align:start position:0% +idea but some + + + align:start position:0% +idea but some +differences okay + + align:start position:0% +differences okay + + + align:start position:0% +differences okay +so + + align:start position:0% + + + + align:start position:0% + +uh barely have time think about this for + + align:start position:0% +uh barely have time think about this for + + + align:start position:0% +uh barely have time think about this for + + align:start position:0% + + + align:start position:0% +seconds we now have two representations + + align:start position:0% +seconds we now have two representations + + + align:start position:0% +seconds we now have two representations +our pooms and a + + align:start position:0% +our pooms and a + + + align:start position:0% +our pooms and a +pooms I'm giving you four examples to + + align:start position:0% +pooms I'm giving you four examples to + + + align:start position:0% +pooms I'm giving you four examples to +think through and your job is to figure + + align:start position:0% +think through and your job is to figure + + + align:start position:0% +think through and your job is to figure +out which of those functionals + + align:start position:0% +out which of those functionals + + + align:start position:0% +out which of those functionals +correspond to + + align:start position:0% +correspond to + + + align:start position:0% +correspond to +convergent responses when excited by a + + align:start position:0% +convergent responses when excited by a + + + align:start position:0% +convergent responses when excited by a +unit sample or a unit impulse + + align:start position:0% + + + + align:start position:0% + +signal + + align:start position:0% + + + + align:start position:0% + +for + + align:start position:0% + + + + align:start position:0% + +so how do I think about this how do I is + + align:start position:0% +so how do I think about this how do I is + + + align:start position:0% +so how do I think about this how do I is +this convergent or + + align:start position:0% +this convergent or + + + align:start position:0% +this convergent or +Divergent what do I think + + align:start position:0% +Divergent what do I think + + + align:start position:0% +Divergent what do I think +about step + + align:start position:0% +about step + + + align:start position:0% +about step +one convergent how' you get that yeah is + + align:start position:0% +one convergent how' you get that yeah is + + + align:start position:0% +one convergent how' you get that yeah is +this + + align:start position:0% + + + + align:start position:0% + +one so factor it's polinomial you get a + + align:start position:0% +one so factor it's polinomial you get a + + + align:start position:0% +one so factor it's polinomial you get a +pole at minus a half and a pole at plus + + align:start position:0% +pole at minus a half and a pole at plus + + + align:start position:0% +pole at minus a half and a pole at plus +a half they're both inside you in a + + align:start position:0% +a half they're both inside you in a + + + align:start position:0% +a half they're both inside you in a +circle they both + + align:start position:0% +circle they both + + + align:start position:0% +circle they both +converge how about this + + align:start position:0% +converge how about this + + + align:start position:0% +converge how about this +one same equations same + + align:start position:0% +one same equations same + + + align:start position:0% +one same equations same +answer kind + + align:start position:0% +answer kind + + + align:start position:0% +answer kind +of same poles minus a half and plus a + + align:start position:0% +of same poles minus a half and plus a + + + align:start position:0% +of same poles minus a half and plus a +half convergent or + + align:start position:0% +half convergent or + + + align:start position:0% +half convergent or +Divergent Divergent because the regions + + align:start position:0% +Divergent Divergent because the regions + + + align:start position:0% +Divergent Divergent because the regions +are different right one of the poles is + + align:start position:0% +are different right one of the poles is + + + align:start position:0% +are different right one of the poles is +in the right half + + align:start position:0% +in the right half + + + align:start position:0% +in the right half +plane Divergent how about this + + align:start position:0% +plane Divergent how about this + + + align:start position:0% +plane Divergent how about this +one where were the + + align:start position:0% +one where were the + + + align:start position:0% +one where were the +poles minus a half minus three + + align:start position:0% +poles minus a half minus three + + + align:start position:0% +poles minus a half minus three +halves outside the unit + + align:start position:0% +halves outside the unit + + + align:start position:0% +halves outside the unit +circle one of the poles is outside the + + align:start position:0% +circle one of the poles is outside the + + + align:start position:0% +circle one of the poles is outside the +UN Circle diverges because of that + + align:start position:0% +UN Circle diverges because of that + + + align:start position:0% +UN Circle diverges because of that +pole minus a half and minus three halves + + align:start position:0% +pole minus a half and minus three halves + + + align:start position:0% +pole minus a half and minus three halves +same poles both in the left half + + align:start position:0% +same poles both in the left half + + + align:start position:0% +same poles both in the left half +plane converges that's the point okay so + + align:start position:0% +plane converges that's the point okay so + + + align:start position:0% +plane converges that's the point okay so +they work very similar but there are + + align:start position:0% +they work very similar but there are + + + align:start position:0% +they work very similar but there are +differences and now in the last three + + align:start position:0% +differences and now in the last three + + + align:start position:0% +differences and now in the last three +minutes the last thing I want to tell + + align:start position:0% +minutes the last thing I want to tell + + + align:start position:0% +minutes the last thing I want to tell +you about is that even complex numbers + + align:start position:0% +you about is that even complex numbers + + + align:start position:0% +you about is that even complex numbers +work just the same as in + + align:start position:0% +work just the same as in + + + align:start position:0% +work just the same as in +DT so think about a system that's + + align:start position:0% +DT so think about a system that's + + + align:start position:0% +DT so think about a system that's +slightly harder here I can represent + + align:start position:0% +slightly harder here I can represent + + + align:start position:0% +slightly harder here I can represent +this by this kind of a relationship so + + align:start position:0% +this by this kind of a relationship so + + + align:start position:0% +this by this kind of a relationship so +FAL + + align:start position:0% +FAL + + + align:start position:0% +FAL +KX but f is + + align:start position:0% +KX but f is + + + align:start position:0% +KX but f is +ma right so + + align:start position:0% +ma right so + + + align:start position:0% +ma right so +801 and so I generate a block diagram or + + align:start position:0% +801 and so I generate a block diagram or + + + align:start position:0% +801 and so I generate a block diagram or +a differential equation or however I + + align:start position:0% +a differential equation or however I + + + align:start position:0% +a differential equation or however I +want to think about it and I can solve + + align:start position:0% +want to think about it and I can solve + + + align:start position:0% +want to think about it and I can solve +for the answer what I'd like to do is + + align:start position:0% +for the answer what I'd like to do is + + + align:start position:0% +for the answer what I'd like to do is +think about it in terms of the + + align:start position:0% +think about it in terms of the + + + align:start position:0% +think about it in terms of the +functional + + align:start position:0% +functional + + + align:start position:0% +functional +representation so I just think about + + align:start position:0% +representation so I just think about + + + align:start position:0% +representation so I just think about +take this system that you're familiar + + align:start position:0% +take this system that you're familiar + + + align:start position:0% +take this system that you're familiar +with we did this on on the first lecture + + align:start position:0% +with we did this on on the first lecture + + + align:start position:0% +with we did this on on the first lecture +turn it into a differential + + align:start position:0% +turn it into a differential + + + align:start position:0% +turn it into a differential +equation turn that into a functional + + align:start position:0% +equation turn that into a functional + + + align:start position:0% +equation turn that into a functional +representation and now I want to think + + align:start position:0% +representation and now I want to think + + + align:start position:0% +representation and now I want to think +about how you would solve the functional + + align:start position:0% +about how you would solve the functional + + + align:start position:0% +about how you would solve the functional +representation the idea is just like + + align:start position:0% +representation the idea is just like + + + align:start position:0% +representation the idea is just like +before Factor but now the trick + + align:start position:0% +before Factor but now the trick + + + align:start position:0% +before Factor but now the trick +is that the + + align:start position:0% +is that the + + + align:start position:0% +is that the +factors uh become + + align:start position:0% +factors uh become + + + align:start position:0% +factors uh become +complex so one way you can think about + + align:start position:0% +complex so one way you can think about + + + align:start position:0% +complex so one way you can think about +this is to force the second order system + + align:start position:0% +this is to force the second order system + + + align:start position:0% +this is to force the second order system +into a canonical form the canonical form + + align:start position:0% +into a canonical form the canonical form + + + align:start position:0% +into a canonical form the canonical form +for uh + + align:start position:0% +for uh + + + align:start position:0% +for uh +DT was 1 over 1us p r for CT is a over 1 + + align:start position:0% +DT was 1 over 1us p r for CT is a over 1 + + + align:start position:0% +DT was 1 over 1us p r for CT is a over 1 +minus p a so I want to make factors that + + align:start position:0% +minus p a so I want to make factors that + + + align:start position:0% +minus p a so I want to make factors that +look like that because I know that here + + align:start position:0% +look like that because I know that here + + + align:start position:0% +look like that because I know that here +the response looks like P to the N here + + align:start position:0% +the response looks like P to the N here + + + align:start position:0% +the response looks like P to the N here +the response looks like e to the p t if + + align:start position:0% +the response looks like e to the p t if + + + align:start position:0% +the response looks like e to the p t if +I can coers it into that form I already + + align:start position:0% +I can coers it into that form I already + + + align:start position:0% +I can coers it into that form I already +know the + + align:start position:0% +know the + + + align:start position:0% +know the +answer so that's what's Illustrated here + + align:start position:0% +answer so that's what's Illustrated here + + + align:start position:0% +answer so that's what's Illustrated here +I coers this into that form + + align:start position:0% +I coers this into that form + + + align:start position:0% +I coers this into that form +and then I know uh then I'll know what + + align:start position:0% +and then I know uh then I'll know what + + + align:start position:0% +and then I know uh then I'll know what +the answer looks + + align:start position:0% +the answer looks + + + align:start position:0% +the answer looks +like just like we could in DT substitute + + align:start position:0% +like just like we could in DT substitute + + + align:start position:0% +like just like we could in DT substitute +R goes to one over Z in CT we can + + align:start position:0% +R goes to one over Z in CT we can + + + align:start position:0% +R goes to one over Z in CT we can +substitute a goes to one / s and solve + + align:start position:0% +substitute a goes to one / s and solve + + + align:start position:0% +substitute a goes to one / s and solve +for S we get the same answer same as we + + align:start position:0% +for S we get the same answer same as we + + + align:start position:0% +for S we get the same answer same as we +did in DT except now we call it + + align:start position:0% +did in DT except now we call it + + + align:start position:0% +did in DT except now we call it +s so the poles to this system are plus + + align:start position:0% +s so the poles to this system are plus + + + align:start position:0% +s so the poles to this system are plus +or minus J constant for convenience I'll + + align:start position:0% +or minus J constant for convenience I'll + + + align:start position:0% +or minus J constant for convenience I'll +call the constant Omega + + align:start position:0% +call the constant Omega + + + align:start position:0% +call the constant Omega +KN so then I have a pole at e to the J + + align:start position:0% +KN so then I have a pole at e to the J + + + align:start position:0% +KN so then I have a pole at e to the J +Omega kn + + align:start position:0% +Omega kn + + + align:start position:0% +Omega kn +and another one so I have a poll at J + + align:start position:0% +and another one so I have a poll at J + + + align:start position:0% +and another one so I have a poll at J +Omega KN and a second poll at minus J + + align:start position:0% +Omega KN and a second poll at minus J + + + align:start position:0% +Omega KN and a second poll at minus J +Omega KN by that + + align:start position:0% +Omega KN by that + + + align:start position:0% +Omega KN by that +argument the fundamental modes are e to + + align:start position:0% +argument the fundamental modes are e to + + + align:start position:0% +argument the fundamental modes are e to +the J Omega T and e to the minus J Omega + + align:start position:0% +the J Omega T and e to the minus J Omega + + + align:start position:0% +the J Omega T and e to the minus J Omega +T just like in DT the complex poles gave + + align:start position:0% +T just like in DT the complex poles gave + + + align:start position:0% +T just like in DT the complex poles gave +complex + + align:start position:0% +complex + + + align:start position:0% +complex +modes here the complex pole J Omega KN + + align:start position:0% +modes here the complex pole J Omega KN + + + align:start position:0% +modes here the complex pole J Omega KN +gave a complex mode cos Omega t plus J + + align:start position:0% +gave a complex mode cos Omega t plus J + + + align:start position:0% +gave a complex mode cos Omega t plus J +sin Omega t + + align:start position:0% + + + + align:start position:0% + +and just like DT the system + + align:start position:0% +and just like DT the system + + + align:start position:0% +and just like DT the system +conspires so that started out being a + + align:start position:0% +conspires so that started out being a + + + align:start position:0% +conspires so that started out being a +mass spring system obviously it's not + + align:start position:0% +mass spring system obviously it's not + + + align:start position:0% +mass spring system obviously it's not +going to have an imaginary + + align:start position:0% +going to have an imaginary + + + align:start position:0% +going to have an imaginary +output the system conspires so that the + + align:start position:0% +output the system conspires so that the + + + align:start position:0% +output the system conspires so that the +imaginary parts of the different + + align:start position:0% +imaginary parts of the different + + + align:start position:0% +imaginary parts of the different +fundamental modes kill each other off + + align:start position:0% +fundamental modes kill each other off + + + align:start position:0% +fundamental modes kill each other off +and the answer is U is a real number so + + align:start position:0% +and the answer is U is a real number so + + + align:start position:0% +and the answer is U is a real number so +even though the mode even though the + + align:start position:0% +even though the mode even though the + + + align:start position:0% +even though the mode even though the +pole is complex the multipliers are + + align:start position:0% +pole is complex the multipliers are + + + align:start position:0% +pole is complex the multipliers are +complex this sum is real and if you just + + align:start position:0% +complex this sum is real and if you just + + + align:start position:0% +complex this sum is real and if you just +think about what that sum is by thinking + + align:start position:0% +think about what that sum is by thinking + + + align:start position:0% +think about what that sum is by thinking +about uh uh how complex numbers work you + + align:start position:0% +about uh uh how complex numbers work you + + + align:start position:0% +about uh uh how complex numbers work you +get an expression that looks like Omega + + align:start position:0% +get an expression that looks like Omega + + + align:start position:0% +get an expression that looks like Omega +sin Omega + + align:start position:0% +sin Omega + + + align:start position:0% +sin Omega +T it's kind of a little more fun to + + align:start position:0% +T it's kind of a little more fun to + + + align:start position:0% +T it's kind of a little more fun to +think about how that evolves as a series + + align:start position:0% +think about how that evolves as a series + + + align:start position:0% +think about how that evolves as a series +if we do a tailor series for this we can + + align:start position:0% +if we do a tailor series for this we can + + + align:start position:0% +if we do a tailor series for this we can +represent it that + + align:start position:0% +represent it that + + + align:start position:0% +represent it that +way and the series then the first term + + align:start position:0% +way and the series then the first term + + + align:start position:0% +way and the series then the first term +is + + align:start position:0% + + + + align:start position:0% + +T the second term is a t cubed which + + align:start position:0% +T the second term is a t cubed which + + + align:start position:0% +T the second term is a t cubed which +goes down + + align:start position:0% +goes down + + + align:start position:0% +goes down +then there's a + + align:start position:0% +then there's a + + + align:start position:0% +then there's a +fifth and a + + align:start position:0% +fifth and a + + + align:start position:0% +fifth and a +seventh and a + + align:start position:0% +seventh and a + + + align:start position:0% +seventh and a +ninth and if you keep adding up the + + align:start position:0% +ninth and if you keep adding up the + + + align:start position:0% +ninth and if you keep adding up the +terms amazingly enough the series + + align:start position:0% +terms amazingly enough the series + + + align:start position:0% +terms amazingly enough the series +representation for the operator + + align:start position:0% +representation for the operator + + + align:start position:0% +representation for the operator +expression is the tailor series + + align:start position:0% +expression is the tailor series + + + align:start position:0% +expression is the tailor series +expansion of a sine + + align:start position:0% +expansion of a sine + + + align:start position:0% +expansion of a sine +wave just like we would have expected + + align:start position:0% +wave just like we would have expected + + + align:start position:0% +wave just like we would have expected +again here the response looks like e to + + align:start position:0% +again here the response looks like e to + + + align:start position:0% +again here the response looks like e to +the p t if I can coer it into that form + + align:start position:0% +the p t if I can coer it into that form + + + align:start position:0% +the p t if I can coer it into that form +I already know the + + align:start position:0% +I already know the + + + align:start position:0% +I already know the +answer so that's what's Illustrated here + + align:start position:0% +answer so that's what's Illustrated here + + + align:start position:0% +answer so that's what's Illustrated here +I coers this into that + + align:start position:0% +I coers this into that + + + align:start position:0% +I coers this into that +form and then I know uh then I'll know + + align:start position:0% +form and then I know uh then I'll know + + + align:start position:0% +form and then I know uh then I'll know +what the answer looks + + align:start position:0% +what the answer looks + + + align:start position:0% +what the answer looks +like just like we could in DT substitute + + align:start position:0% +like just like we could in DT substitute + + + align:start position:0% +like just like we could in DT substitute +R goes to one over Z in CT we can + + align:start position:0% +R goes to one over Z in CT we can + + + align:start position:0% +R goes to one over Z in CT we can +substitute a goes to one/ S and solve + + align:start position:0% +substitute a goes to one/ S and solve + + + align:start position:0% +substitute a goes to one/ S and solve +for S we get the same answer same as we + + align:start position:0% +for S we get the same answer same as we + + + align:start position:0% +for S we get the same answer same as we +did in DT except now we call it + + align:start position:0% +did in DT except now we call it + + + align:start position:0% +did in DT except now we call it +s so the poles to this system are plus + + align:start position:0% +s so the poles to this system are plus + + + align:start position:0% +s so the poles to this system are plus +or minus J constant for convenience I'll + + align:start position:0% +or minus J constant for convenience I'll + + + align:start position:0% +or minus J constant for convenience I'll +call the constant Omega + + align:start position:0% +call the constant Omega + + + align:start position:0% +call the constant Omega +KN so then I have a pole at e to the J + + align:start position:0% +KN so then I have a pole at e to the J + + + align:start position:0% +KN so then I have a pole at e to the J +Omega + + align:start position:0% +Omega + + + align:start position:0% +Omega +KN and another one so I have a poll at J + + align:start position:0% +KN and another one so I have a poll at J + + + align:start position:0% +KN and another one so I have a poll at J +Omega KN and a second pole at minus J + + align:start position:0% +Omega KN and a second pole at minus J + + + align:start position:0% +Omega KN and a second pole at minus J +Omega by that + + align:start position:0% +Omega by that + + + align:start position:0% +Omega by that +argument the fundamental modes are e to + + align:start position:0% +argument the fundamental modes are e to + + + align:start position:0% +argument the fundamental modes are e to +the J Omega T and e to the minus J Omega + + align:start position:0% +the J Omega T and e to the minus J Omega + + + align:start position:0% +the J Omega T and e to the minus J Omega +T just like in DT the complex poles gave + + align:start position:0% +T just like in DT the complex poles gave + + + align:start position:0% +T just like in DT the complex poles gave +complex + + align:start position:0% +complex + + + align:start position:0% +complex +modes here the complex pole J Omega KN + + align:start position:0% +modes here the complex pole J Omega KN + + + align:start position:0% +modes here the complex pole J Omega KN +gave a complex mode cos Omega t plus J + + align:start position:0% +gave a complex mode cos Omega t plus J + + + align:start position:0% +gave a complex mode cos Omega t plus J +sin Omega + + align:start position:0% + + + + align:start position:0% + +T and just like DT the system + + align:start position:0% +T and just like DT the system + + + align:start position:0% +T and just like DT the system +conspires so that start without being a + + align:start position:0% +conspires so that start without being a + + + align:start position:0% +conspires so that start without being a +mass spring system obviously it's not + + align:start position:0% +mass spring system obviously it's not + + + align:start position:0% +mass spring system obviously it's not +going to have an imaginary + + align:start position:0% +going to have an imaginary + + + align:start position:0% +going to have an imaginary +output the system conspires so that the + + align:start position:0% +output the system conspires so that the + + + align:start position:0% +output the system conspires so that the +imaginary parts of the different + + align:start position:0% +imaginary parts of the different + + + align:start position:0% +imaginary parts of the different +fundamental modes kill each other off + + align:start position:0% +fundamental modes kill each other off + + + align:start position:0% +fundamental modes kill each other off +and the answer is um is a real number so + + align:start position:0% +and the answer is um is a real number so + + + align:start position:0% +and the answer is um is a real number so +even though the mode even though the + + align:start position:0% +even though the mode even though the + + + align:start position:0% +even though the mode even though the +poll is complex the multipliers are + + align:start position:0% +poll is complex the multipliers are + + + align:start position:0% +poll is complex the multipliers are +complex the sum is real and if you just + + align:start position:0% +complex the sum is real and if you just + + + align:start position:0% +complex the sum is real and if you just +think about what that sum is by thinking + + align:start position:0% +think about what that sum is by thinking + + + align:start position:0% +think about what that sum is by thinking +about uh uh how complex numbers work you + + align:start position:0% +about uh uh how complex numbers work you + + + align:start position:0% +about uh uh how complex numbers work you +get an expression that looks like Omega + + align:start position:0% +get an expression that looks like Omega + + + align:start position:0% +get an expression that looks like Omega +not sin Omega + + align:start position:0% +not sin Omega + + + align:start position:0% +not sin Omega +T it's kind of a little more fun to + + align:start position:0% +T it's kind of a little more fun to + + + align:start position:0% +T it's kind of a little more fun to +think about how that evolves as a series + + align:start position:0% +think about how that evolves as a series + + + align:start position:0% +think about how that evolves as a series +if we do a tailor series for this we can + + align:start position:0% +if we do a tailor series for this we can + + + align:start position:0% +if we do a tailor series for this we can +represent it that + + align:start position:0% +represent it that + + + align:start position:0% +represent it that +way and the series then the first term + + align:start position:0% +way and the series then the first term + + + align:start position:0% +way and the series then the first term +is + + align:start position:0% + + + + align:start position:0% + +T the second term is a t cubed which + + align:start position:0% +T the second term is a t cubed which + + + align:start position:0% +T the second term is a t cubed which +goes + + align:start position:0% +goes + + + align:start position:0% +goes +down then there's a + + align:start position:0% +down then there's a + + + align:start position:0% +down then there's a +fifth and a + + align:start position:0% +fifth and a + + + align:start position:0% +fifth and a +seventh and a + + align:start position:0% +seventh and a + + + align:start position:0% +seventh and a +ninth and if you keep adding up the + + align:start position:0% +ninth and if you keep adding up the + + + align:start position:0% +ninth and if you keep adding up the +terms amazingly enough the series + + align:start position:0% +terms amazingly enough the series + + + align:start position:0% +terms amazingly enough the series +representation for the operator + + align:start position:0% +representation for the operator + + + align:start position:0% +representation for the operator +expression is the tailor series + + align:start position:0% +expression is the tailor series + + + align:start position:0% +expression is the tailor series +expansion of a sine + + align:start position:0% +expansion of a sine + + + align:start position:0% +expansion of a sine +wave just like we would have expected + + align:start position:0% +wave just like we would have expected + + + align:start position:0% +wave just like we would have expected +again I solved a differential equation a + + align:start position:0% +again I solved a differential equation a + + + align:start position:0% +again I solved a differential equation a +second order differential equation this + + align:start position:0% +second order differential equation this + + + align:start position:0% +second order differential equation this +time without calculus all I did was + + align:start position:0% +time without calculus all I did was + + + align:start position:0% +time without calculus all I did was +polinomial math and so with that I'll + + align:start position:0% +polinomial math and so with that I'll + + + align:start position:0% +polinomial math and so with that I'll +finish just by saying today what we did + + align:start position:0% +finish just by saying today what we did + + + align:start position:0% +finish just by saying today what we did +was introduce and basically finish + + align:start position:0% +was introduce and basically finish + + + align:start position:0% +was introduce and basically finish +CT because there's such a strong analogy + + align:start position:0% +CT because there's such a strong analogy + + + align:start position:0% +CT because there's such a strong analogy +between what we did in DT and how we'll + + align:start position:0% +between what we did in DT and how we'll + + + align:start position:0% +between what we did in DT and how we'll +approach thinking about + + align:start position:0% + + + + align:start position:0% + +CT \ No newline at end of file diff --git a/4nXw-f6NJ9s.txt b/4nXw-f6NJ9s.txt new file mode 100644 index 0000000000000000000000000000000000000000..1028880e0a6078df47d20895963dea8395a3616b --- /dev/null +++ b/4nXw-f6NJ9s.txt @@ -0,0 +1,14266 @@ +align:start position:0% + +hi everybody + + align:start position:0% +hi everybody + + + align:start position:0% +hi everybody +uh welcome to the last lecture of 6006 + + align:start position:0% +uh welcome to the last lecture of 6006 + + + align:start position:0% +uh welcome to the last lecture of 6006 +last lecture we talked about + + align:start position:0% +last lecture we talked about + + + align:start position:0% +last lecture we talked about +summing up this class and talking about + + align:start position:0% +summing up this class and talking about + + + align:start position:0% +summing up this class and talking about +future courses in the department + + align:start position:0% +future courses in the department + + + align:start position:0% +future courses in the department +that use this material um + + align:start position:0% +that use this material um + + + align:start position:0% +that use this material um +just as a pointer to some of those + + align:start position:0% +just as a pointer to some of those + + + align:start position:0% +just as a pointer to some of those +classes i have a little slide here i + + align:start position:0% +classes i have a little slide here i + + + align:start position:0% +classes i have a little slide here i +didn't get to + + align:start position:0% +didn't get to + + + align:start position:0% +didn't get to +uh at the last lecture talking about + + align:start position:0% +uh at the last lecture talking about + + + align:start position:0% +uh at the last lecture talking about +kind of what i was talking about the end + + align:start position:0% +kind of what i was talking about the end + + + align:start position:0% +kind of what i was talking about the end +of last lecture about + + align:start position:0% +of last lecture about + + + align:start position:0% +of last lecture about +different models uh different + + align:start position:0% +different models uh different + + + align:start position:0% +different models uh different +specialized classes + + align:start position:0% +specialized classes + + + align:start position:0% +specialized classes +on different aspects of o6 material + + align:start position:0% +on different aspects of o6 material + + + align:start position:0% +on different aspects of o6 material +for example more graph stuff + + align:start position:0% +for example more graph stuff + + + align:start position:0% +for example more graph stuff +different models of computation + + align:start position:0% +different models of computation + + + align:start position:0% +different models of computation +randomness + + align:start position:0% +randomness + + + align:start position:0% +randomness +uh complexity all of these things have + + align:start position:0% +uh complexity all of these things have + + + align:start position:0% +uh complexity all of these things have +their own specialized classes + + align:start position:0% +their own specialized classes + + + align:start position:0% +their own specialized classes +in the department uh as well as a lot of + + align:start position:0% +in the department uh as well as a lot of + + + align:start position:0% +in the department uh as well as a lot of +applications + + align:start position:0% +applications + + + align:start position:0% +applications +uh for this material in subjects like + + align:start position:0% +uh for this material in subjects like + + + align:start position:0% +uh for this material in subjects like +biology cryptography + + align:start position:0% +biology cryptography + + + align:start position:0% +biology cryptography +and in particular for your instructors + + align:start position:0% +and in particular for your instructors + + + align:start position:0% +and in particular for your instructors +uh the the realm of graphics and + + align:start position:0% +uh the the realm of graphics and + + + align:start position:0% +uh the the realm of graphics and +geometry + + align:start position:0% +geometry + + + align:start position:0% +geometry +okay so all of all of your instructors + + align:start position:0% +okay so all of all of your instructors + + + align:start position:0% +okay so all of all of your instructors +this term happen to be + + align:start position:0% +this term happen to be + + + align:start position:0% +this term happen to be +geometers and have uh be interested in + + align:start position:0% +geometers and have uh be interested in + + + align:start position:0% +geometers and have uh be interested in +geometry related problems um + + align:start position:0% +geometry related problems um + + + align:start position:0% +geometry related problems um +me in particular i didn't start out in + + align:start position:0% +me in particular i didn't start out in + + + align:start position:0% +me in particular i didn't start out in +computer science + + align:start position:0% +computer science + + + align:start position:0% +computer science +i started out in mechanical engineering + + align:start position:0% +i started out in mechanical engineering + + + align:start position:0% +i started out in mechanical engineering +uh + + align:start position:0% +uh + + + align:start position:0% +uh +and the thing that was my passion um + + align:start position:0% +and the thing that was my passion um + + + align:start position:0% +and the thing that was my passion um +coming into mit + + align:start position:0% +coming into mit + + + align:start position:0% +coming into mit +was origami and so here's a couple of + + align:start position:0% +was origami and so here's a couple of + + + align:start position:0% +was origami and so here's a couple of +uh pieces that uh i designed um + + align:start position:0% +uh pieces that uh i designed um + + + align:start position:0% +uh pieces that uh i designed um +origami pieces one square sheet of paper + + align:start position:0% +origami pieces one square sheet of paper + + + align:start position:0% +origami pieces one square sheet of paper +without cutting here's a + + align:start position:0% +without cutting here's a + + + align:start position:0% +without cutting here's a +a lobster and here's a + + align:start position:0% +a lobster and here's a + + + align:start position:0% +a lobster and here's a +you know a copyrighted dinosaur from a + + align:start position:0% +you know a copyrighted dinosaur from a + + + align:start position:0% +you know a copyrighted dinosaur from a +particular movie of the year that i + + align:start position:0% +particular movie of the year that i + + + align:start position:0% +particular movie of the year that i +designed it + + align:start position:0% +designed it + + + align:start position:0% +designed it +um i + + align:start position:0% +um i + + + align:start position:0% +um i +uh when i was young in high school i + + align:start position:0% +uh when i was young in high school i + + + align:start position:0% +uh when i was young in high school i +started designing my own origami models + + align:start position:0% +started designing my own origami models + + + align:start position:0% +started designing my own origami models +and what i didn't realize was the + + align:start position:0% +and what i didn't realize was the + + + align:start position:0% +and what i didn't realize was the +procedures + + align:start position:0% +procedures + + + align:start position:0% +procedures +that i went about designing these models + + align:start position:0% +that i went about designing these models + + + align:start position:0% +that i went about designing these models +was + + align:start position:0% +was + + + align:start position:0% +was +actually algorithms right i just didn't + + align:start position:0% +actually algorithms right i just didn't + + + align:start position:0% +actually algorithms right i just didn't +have the mathematical language + + align:start position:0% +have the mathematical language + + + align:start position:0% +have the mathematical language +to to understand exactly what i was + + align:start position:0% +to to understand exactly what i was + + + align:start position:0% +to to understand exactly what i was +doing but i could gain some intuition as + + align:start position:0% +doing but i could gain some intuition as + + + align:start position:0% +doing but i could gain some intuition as +an origami artist + + align:start position:0% +an origami artist + + + align:start position:0% +an origami artist +and design these things by using some of + + align:start position:0% +and design these things by using some of + + + align:start position:0% +and design these things by using some of +those algorithmic techniques it wasn't + + align:start position:0% +those algorithmic techniques it wasn't + + + align:start position:0% +those algorithmic techniques it wasn't +until + + align:start position:0% +until + + + align:start position:0% +until +grad school as a mechanical engineer + + align:start position:0% +grad school as a mechanical engineer + + + align:start position:0% +grad school as a mechanical engineer +that + + align:start position:0% +that + + + align:start position:0% +that +i started talking + + align:start position:0% +i started talking + + + align:start position:0% +i started talking +with uh our other instructor here + + align:start position:0% +with uh our other instructor here + + + align:start position:0% +with uh our other instructor here +professor domain + + align:start position:0% +professor domain + + + align:start position:0% +professor domain +about uh using algorithms in computer + + align:start position:0% +about uh using algorithms in computer + + + align:start position:0% +about uh using algorithms in computer +science + + align:start position:0% +science + + + align:start position:0% +science +to design not just origami + + align:start position:0% +to design not just origami + + + align:start position:0% +to design not just origami +uh which we both do but also uh + + align:start position:0% +uh which we both do but also uh + + + align:start position:0% +uh which we both do but also uh +folded structures that can be used for + + align:start position:0% +folded structures that can be used for + + + align:start position:0% +folded structures that can be used for +mechanical applications like space + + align:start position:0% +mechanical applications like space + + + align:start position:0% +mechanical applications like space +flight um uh deployable bridges + + align:start position:0% +flight um uh deployable bridges + + + align:start position:0% +flight um uh deployable bridges +in in like um in times when you + + align:start position:0% +in in like um in times when you + + + align:start position:0% +in in like um in times when you +you can't you need a temporary + + align:start position:0% +you can't you need a temporary + + + align:start position:0% +you can't you need a temporary +bridge or shelter or something like that + + align:start position:0% +bridge or shelter or something like that + + + align:start position:0% +bridge or shelter or something like that +deployable structures + + align:start position:0% +deployable structures + + + align:start position:0% +deployable structures +where you might need to make folded + + align:start position:0% +where you might need to make folded + + + align:start position:0% +where you might need to make folded +structures transformable structures + + align:start position:0% +structures transformable structures + + + align:start position:0% +structures transformable structures +that can have different applications + + align:start position:0% +that can have different applications + + + align:start position:0% +that can have different applications +for different purposes need to + + align:start position:0% +for different purposes need to + + + align:start position:0% +for different purposes need to +reconfigure the dream being that + + align:start position:0% +reconfigure the dream being that + + + align:start position:0% +reconfigure the dream being that +we have these powerful devices in our + + align:start position:0% +we have these powerful devices in our + + + align:start position:0% +we have these powerful devices in our +pockets right now + + align:start position:0% +pockets right now + + + align:start position:0% +pockets right now +cell phones uh which uh you know are + + align:start position:0% +cell phones uh which uh you know are + + + align:start position:0% +cell phones uh which uh you know are +really powerful because we can + + align:start position:0% +really powerful because we can + + + align:start position:0% +really powerful because we can +reconfigure + + align:start position:0% +reconfigure + + + align:start position:0% +reconfigure +the bits in them to make software of all + + align:start position:0% +the bits in them to make software of all + + + align:start position:0% +the bits in them to make software of all +different kinds right + + align:start position:0% +different kinds right + + + align:start position:0% +different kinds right +there's a there's a exponential number + + align:start position:0% +there's a there's a exponential number + + + align:start position:0% +there's a there's a exponential number +of different programs that we can write + + align:start position:0% +of different programs that we can write + + + align:start position:0% +of different programs that we can write +and that's part of why you're here is to + + align:start position:0% +and that's part of why you're here is to + + + align:start position:0% +and that's part of why you're here is to +write the next best one + + align:start position:0% +write the next best one + + + align:start position:0% +write the next best one +right so that's how to how to make uh + + align:start position:0% +right so that's how to how to make uh + + + align:start position:0% +right so that's how to how to make uh +kind of a universal a device uh + + align:start position:0% +kind of a universal a device uh + + + align:start position:0% +kind of a universal a device uh +at the electronic level what if we could + + align:start position:0% +at the electronic level what if we could + + + align:start position:0% +at the electronic level what if we could +do that + + align:start position:0% +do that + + + align:start position:0% +do that +in a material from a material standpoint + + align:start position:0% +in a material from a material standpoint + + + align:start position:0% +in a material from a material standpoint +what if i could + + align:start position:0% +what if i could + + + align:start position:0% +what if i could +reprogram the matter in my phone so that + + align:start position:0% +reprogram the matter in my phone so that + + + align:start position:0% +reprogram the matter in my phone so that +not only + + align:start position:0% +not only + + + align:start position:0% +not only +uh could i reprogram the app that's on + + align:start position:0% +uh could i reprogram the app that's on + + + align:start position:0% +uh could i reprogram the app that's on +your phone + + align:start position:0% +your phone + + + align:start position:0% +your phone +but instead of having the say the iphone + + align:start position:0% +but instead of having the say the iphone + + + align:start position:0% +but instead of having the say the iphone +10 or whatever that you have and and you + + align:start position:0% +10 or whatever that you have and and you + + + align:start position:0% +10 or whatever that you have and and you +want to go buy the iphone 11 instead you + + align:start position:0% +want to go buy the iphone 11 instead you + + + align:start position:0% +want to go buy the iphone 11 instead you +you download a software app that then + + align:start position:0% +you download a software app that then + + + align:start position:0% +you download a software app that then +reconfigures the matter in your phone it + + align:start position:0% +reconfigures the matter in your phone it + + + align:start position:0% +reconfigures the matter in your phone it +folds or reconfigures + + align:start position:0% +folds or reconfigures + + + align:start position:0% +folds or reconfigures +into the next generation iphone + + align:start position:0% +into the next generation iphone + + + align:start position:0% +into the next generation iphone +you you don't have to throw away that + + align:start position:0% +you you don't have to throw away that + + + align:start position:0% +you you don't have to throw away that +old one you can essentially recycle the + + align:start position:0% +old one you can essentially recycle the + + + align:start position:0% +old one you can essentially recycle the +material that you have + + align:start position:0% +material that you have + + + align:start position:0% +material that you have +uh to potentially uh save material save + + align:start position:0% +uh to potentially uh save material save + + + align:start position:0% +uh to potentially uh save material save +cost + + align:start position:0% +cost + + + align:start position:0% +cost +and be better for the environment + + align:start position:0% +and be better for the environment + + + align:start position:0% +and be better for the environment +potentially so uh + + align:start position:0% +potentially so uh + + + align:start position:0% +potentially so uh +i started moving into computer science + + align:start position:0% +i started moving into computer science + + + align:start position:0% +i started moving into computer science +because i found that it was + + align:start position:0% +because i found that it was + + + align:start position:0% +because i found that it was +a really good way to model the world and + + align:start position:0% +a really good way to model the world and + + + align:start position:0% +a really good way to model the world and +solve some really interesting problems + + align:start position:0% +solve some really interesting problems + + + align:start position:0% +solve some really interesting problems +uh about folding that i i really enjoyed + + align:start position:0% +uh about folding that i i really enjoyed + + + align:start position:0% +uh about folding that i i really enjoyed +so um the the three of us today + + align:start position:0% +so um the the three of us today + + + align:start position:0% +so um the the three of us today +are going to spend some time talking a + + align:start position:0% +are going to spend some time talking a + + + align:start position:0% +are going to spend some time talking a +little bit about how we can use + + align:start position:0% +little bit about how we can use + + + align:start position:0% +little bit about how we can use +algorithms + + align:start position:0% +algorithms + + + align:start position:0% +algorithms +606 material and beyond in our own + + align:start position:0% +606 material and beyond in our own + + + align:start position:0% +606 material and beyond in our own +research + + align:start position:0% +research + + + align:start position:0% +research +and we're going to start off with + + align:start position:0% +and we're going to start off with + + + align:start position:0% +and we're going to start off with +professor domain + + align:start position:0% +professor domain + + + align:start position:0% +professor domain +and then professor solomon + + align:start position:0% + + + + align:start position:0% + +sweet so why don't i just jump into + + align:start position:0% +sweet so why don't i just jump into + + + align:start position:0% +sweet so why don't i just jump into +uh computational origami and geometric + + align:start position:0% +uh computational origami and geometric + + + align:start position:0% +uh computational origami and geometric +folding algorithms is sort of a broader + + align:start position:0% +folding algorithms is sort of a broader + + + align:start position:0% +folding algorithms is sort of a broader +umbrella for folding + + align:start position:0% +umbrella for folding + + + align:start position:0% +umbrella for folding +related things which is encapsulated by + + align:start position:0% +related things which is encapsulated by + + + align:start position:0% +related things which is encapsulated by +this class 6.849 + + align:start position:0% +this class 6.849 + + + align:start position:0% +this class 6.849 +which is happening next fall so you + + align:start position:0% +which is happening next fall so you + + + align:start position:0% +which is happening next fall so you +should all take it + + align:start position:0% +should all take it + + + align:start position:0% +should all take it +06 should be a reasonable background + + align:start position:0% +06 should be a reasonable background + + + align:start position:0% +06 should be a reasonable background +and in general we're interested in two + + align:start position:0% +and in general we're interested in two + + + align:start position:0% +and in general we're interested in two +kinds of problems one + + align:start position:0% +kinds of problems one + + + align:start position:0% +kinds of problems one +the big one is origami design or general + + align:start position:0% +the big one is origami design or general + + + align:start position:0% +the big one is origami design or general +folding design where you have some + + align:start position:0% +folding design where you have some + + + align:start position:0% +folding design where you have some +specifications of what you'd like to + + align:start position:0% +specifications of what you'd like to + + + align:start position:0% +specifications of what you'd like to +build + + align:start position:0% +build + + + align:start position:0% +build +in this case i wanted to make a logo for + + align:start position:0% +in this case i wanted to make a logo for + + + align:start position:0% +in this case i wanted to make a logo for + + align:start position:0% + + + align:start position:0% +and i imagined extruding that text + + align:start position:0% +and i imagined extruding that text + + + align:start position:0% +and i imagined extruding that text +into third third dimension and then i + + align:start position:0% +into third third dimension and then i + + + align:start position:0% +into third third dimension and then i +wanted an algorithm + + align:start position:0% +wanted an algorithm + + + align:start position:0% +wanted an algorithm +to figure tell me how to fold that + + align:start position:0% +to figure tell me how to fold that + + + align:start position:0% +to figure tell me how to fold that +structure and so there is an algorithm + + align:start position:0% +structure and so there is an algorithm + + + align:start position:0% +structure and so there is an algorithm +which i'll talk about in a moment that + + align:start position:0% +which i'll talk about in a moment that + + + align:start position:0% +which i'll talk about in a moment that +gives you a crease pattern and then + + align:start position:0% +gives you a crease pattern and then + + + align:start position:0% +gives you a crease pattern and then +currently you fold it by hand the dream + + align:start position:0% +currently you fold it by hand the dream + + + align:start position:0% +currently you fold it by hand the dream +is we'll eventually have folding + + align:start position:0% +is we'll eventually have folding + + + align:start position:0% +is we'll eventually have folding +machines that do it all for us + + align:start position:0% +machines that do it all for us + + + align:start position:0% +machines that do it all for us +um and so that's the origami design + + align:start position:0% +um and so that's the origami design + + + align:start position:0% +um and so that's the origami design +where you go from the + + align:start position:0% +where you go from the + + + align:start position:0% +where you go from the +the target shape back to the + + align:start position:0% +the target shape back to the + + + align:start position:0% +the target shape back to the +um to the crease pattern the reverse + + align:start position:0% +um to the crease pattern the reverse + + + align:start position:0% +um to the crease pattern the reverse +direction is sort of foldability if i + + align:start position:0% +direction is sort of foldability if i + + + align:start position:0% +direction is sort of foldability if i +gave you a structure + + align:start position:0% +gave you a structure + + + align:start position:0% +gave you a structure +like this and i wanted to know does it + + align:start position:0% +like this and i wanted to know does it + + + align:start position:0% +like this and i wanted to know does it +fold + + align:start position:0% +fold + + + align:start position:0% +fold +that's a problem we call foldability in + + align:start position:0% +that's a problem we call foldability in + + + align:start position:0% +that's a problem we call foldability in +general + + align:start position:0% +general + + + align:start position:0% +general +a class of problems and sadly most of + + align:start position:0% +a class of problems and sadly most of + + + align:start position:0% +a class of problems and sadly most of +those problems are np hard + + align:start position:0% +those problems are np hard + + + align:start position:0% +those problems are np hard +jason and i proved that foldability is + + align:start position:0% +jason and i proved that foldability is + + + align:start position:0% +jason and i proved that foldability is +hard for a general given a crease + + align:start position:0% +hard for a general given a crease + + + align:start position:0% +hard for a general given a crease +pattern like that + + align:start position:0% +pattern like that + + + align:start position:0% +pattern like that +telling you whether it folds into + + align:start position:0% +telling you whether it folds into + + + align:start position:0% +telling you whether it folds into +anything it turns out to be np hard so + + align:start position:0% +anything it turns out to be np hard so + + + align:start position:0% +anything it turns out to be np hard so +that's + + align:start position:0% +that's + + + align:start position:0% +that's +bad news so we focus a lot on the design + + align:start position:0% +bad news so we focus a lot on the design + + + align:start position:0% +bad news so we focus a lot on the design +problem because that + + align:start position:0% +problem because that + + + align:start position:0% +problem because that +actually tends to be easier we can solve + + align:start position:0% +actually tends to be easier we can solve + + + align:start position:0% +actually tends to be easier we can solve +it with algorithms like + + align:start position:0% +it with algorithms like + + + align:start position:0% +it with algorithms like +that one you're seeing um and so + + align:start position:0% +that one you're seeing um and so + + + align:start position:0% +that one you're seeing um and so +a long time ago we proved that you can + + align:start position:0% +a long time ago we proved that you can + + + align:start position:0% +a long time ago we proved that you can +fold everything + + align:start position:0% +fold everything + + + align:start position:0% +fold everything +if i give you a square piece of paper + + align:start position:0% +if i give you a square piece of paper + + + align:start position:0% +if i give you a square piece of paper +and you take + + align:start position:0% +and you take + + + align:start position:0% +and you take +any polygon you want to make or maybe + + align:start position:0% +any polygon you want to make or maybe + + + align:start position:0% +any polygon you want to make or maybe +the paper's white on one side black on + + align:start position:0% +the paper's white on one side black on + + + align:start position:0% +the paper's white on one side black on +the other + + align:start position:0% +the other + + + align:start position:0% +the other +you you want to fold some two color + + align:start position:0% +you you want to fold some two color + + + align:start position:0% +you you want to fold some two color +pattern like a zebra or in general some + + align:start position:0% +pattern like a zebra or in general some + + + align:start position:0% +pattern like a zebra or in general some +three-dimensional surface + + align:start position:0% +three-dimensional surface + + + align:start position:0% +three-dimensional surface +like these guys there is a way to fold + + align:start position:0% +like these guys there is a way to fold + + + align:start position:0% +like these guys there is a way to fold +it from a large enough square of paper + + align:start position:0% +it from a large enough square of paper + + + align:start position:0% +it from a large enough square of paper +and it's actually really easy to prove + + align:start position:0% +and it's actually really easy to prove + + + align:start position:0% +and it's actually really easy to prove +that with an algorithm i have + + align:start position:0% +that with an algorithm i have + + + align:start position:0% +that with an algorithm i have +a sketch of the two pages of proof that + + align:start position:0% +a sketch of the two pages of proof that + + + align:start position:0% +a sketch of the two pages of proof that +we go over in 6849 + + align:start position:0% +we go over in 6849 + + + align:start position:0% +we go over in 6849 +but i'll just hand wave a little bit uh + + align:start position:0% +but i'll just hand wave a little bit uh + + + align:start position:0% +but i'll just hand wave a little bit uh +if you take a piece of paper + + align:start position:0% +if you take a piece of paper + + + align:start position:0% +if you take a piece of paper +like my lecture notes here the first + + align:start position:0% +like my lecture notes here the first + + + align:start position:0% +like my lecture notes here the first +thing you do + + align:start position:0% +thing you do + + + align:start position:0% +thing you do +is fold it down into a very long narrow + + align:start position:0% +is fold it down into a very long narrow + + + align:start position:0% +is fold it down into a very long narrow +strip + + align:start position:0% +strip + + + align:start position:0% +strip +much longer and narrower than this one + + align:start position:0% +much longer and narrower than this one + + + align:start position:0% +much longer and narrower than this one +wasting most of the material + + align:start position:0% +wasting most of the material + + + align:start position:0% +wasting most of the material +and then you take your strip and you + + align:start position:0% +and then you take your strip and you + + + align:start position:0% +and then you take your strip and you +just figure out how to + + align:start position:0% +just figure out how to + + + align:start position:0% +just figure out how to +turn it in some general way and then you + + align:start position:0% +turn it in some general way and then you + + + align:start position:0% +turn it in some general way and then you +just sort of zigzag back and forth along + + align:start position:0% +just sort of zigzag back and forth along + + + align:start position:0% +just sort of zigzag back and forth along +the surface + + align:start position:0% +the surface + + + align:start position:0% +the surface +so it's very cool in that you can prove + + align:start position:0% +so it's very cool in that you can prove + + + align:start position:0% +so it's very cool in that you can prove +with an algorithm in a very short amount + + align:start position:0% +with an algorithm in a very short amount + + + align:start position:0% +with an algorithm in a very short amount +of time + + align:start position:0% +of time + + + align:start position:0% +of time +to someone you can actually fold + + align:start position:0% +to someone you can actually fold + + + align:start position:0% +to someone you can actually fold +everything of course it's a terrible + + align:start position:0% +everything of course it's a terrible + + + align:start position:0% +everything of course it's a terrible +folding because in the very first step + + align:start position:0% +folding because in the very first step + + + align:start position:0% +folding because in the very first step +we throw away + + align:start position:0% +we throw away + + + align:start position:0% +we throw away +all but epsilon of the material but it's + + align:start position:0% +all but epsilon of the material but it's + + + align:start position:0% +all but epsilon of the material but it's +a starting point and then that was back + + align:start position:0% +a starting point and then that was back + + + align:start position:0% +a starting point and then that was back +in the 90s late 90s + + align:start position:0% +in the 90s late 90s + + + align:start position:0% +in the 90s late 90s +one of the first results in + + align:start position:0% +one of the first results in + + + align:start position:0% +one of the first results in +computational origami and + + align:start position:0% +computational origami and + + + align:start position:0% +computational origami and +in modern times we look for better + + align:start position:0% +in modern times we look for better + + + align:start position:0% +in modern times we look for better +algorithms that are more efficient that + + align:start position:0% +algorithms that are more efficient that + + + align:start position:0% +algorithms that are more efficient that +try to minimize the scale factor from + + align:start position:0% +try to minimize the scale factor from + + + align:start position:0% +try to minimize the scale factor from +how big of a piece of paper do i start + + align:start position:0% +how big of a piece of paper do i start + + + align:start position:0% +how big of a piece of paper do i start +from + + align:start position:0% +from + + + align:start position:0% +from +to how big of a model do i get um and + + align:start position:0% +to how big of a model do i get um and + + + align:start position:0% +to how big of a model do i get um and +one of the cool ways + + align:start position:0% +one of the cool ways + + + align:start position:0% +one of the cool ways +these days which was invented by + + align:start position:0% +these days which was invented by + + + align:start position:0% +these days which was invented by +tomihirotachi and then analyzed by the + + align:start position:0% +tomihirotachi and then analyzed by the + + + align:start position:0% +tomihirotachi and then analyzed by the +two of us + + align:start position:0% +two of us + + + align:start position:0% +two of us +it's called orgamizer it's free software + + align:start position:0% +it's called orgamizer it's free software + + + align:start position:0% +it's called orgamizer it's free software +you take a 3d model + + align:start position:0% +you take a 3d model + + + align:start position:0% +you take a 3d model +and you can it makes it into a crease + + align:start position:0% +and you can it makes it into a crease + + + align:start position:0% +and you can it makes it into a crease +pattern that you fold from a square in + + align:start position:0% +pattern that you fold from a square in + + + align:start position:0% +pattern that you fold from a square in +this case it uses 22 percent of the area + + align:start position:0% +this case it uses 22 percent of the area + + + align:start position:0% +this case it uses 22 percent of the area +which is pretty good + + align:start position:0% +which is pretty good + + + align:start position:0% +which is pretty good +um similar to these guys + + align:start position:0% +um similar to these guys + + + align:start position:0% +um similar to these guys +in terms of efficiency but very very + + align:start position:0% +in terms of efficiency but very very + + + align:start position:0% +in terms of efficiency but very very +different kind of folding + + align:start position:0% +different kind of folding + + + align:start position:0% +different kind of folding +than what you would get from more + + align:start position:0% +than what you would get from more + + + align:start position:0% +than what you would get from more +traditional origami design which uses + + align:start position:0% +traditional origami design which uses + + + align:start position:0% +traditional origami design which uses +different algorithms which i'm not going + + align:start position:0% +different algorithms which i'm not going + + + align:start position:0% +different algorithms which i'm not going +to talk about but you should take the + + align:start position:0% +to talk about but you should take the + + + align:start position:0% +to talk about but you should take the +class jason gives a lecture in the class + + align:start position:0% +class jason gives a lecture in the class + + + align:start position:0% +class jason gives a lecture in the class +that you can + + align:start position:0% +that you can + + + align:start position:0% +that you can +learn from him but the you know the + + align:start position:0% +learn from him but the you know the + + + align:start position:0% +learn from him but the you know the +vision is we can take any sheet of + + align:start position:0% +vision is we can take any sheet of + + + align:start position:0% +vision is we can take any sheet of +material that can hold a crease + + align:start position:0% +material that can hold a crease + + + align:start position:0% +material that can hold a crease +like this sheet of steel that tomohiro + + align:start position:0% +like this sheet of steel that tomohiro + + + align:start position:0% +like this sheet of steel that tomohiro +is folding i was cut + + align:start position:0% +is folding i was cut + + + align:start position:0% +is folding i was cut +by a big laser cutter at mit and this is + + align:start position:0% +by a big laser cutter at mit and this is + + + align:start position:0% +by a big laser cutter at mit and this is +him in this data center several years + + align:start position:0% +him in this data center several years + + + align:start position:0% +him in this data center several years +ago + + align:start position:0% +ago + + + align:start position:0% +ago +folding it into a steel bunny + + align:start position:0% +folding it into a steel bunny + + + align:start position:0% +folding it into a steel bunny +and so this is like a totally new way to + + align:start position:0% +and so this is like a totally new way to + + + align:start position:0% +and so this is like a totally new way to +manufacture + + align:start position:0% +manufacture + + + align:start position:0% +manufacture +3d objects and you can make particularly + + align:start position:0% +3d objects and you can make particularly + + + align:start position:0% +3d objects and you can make particularly +interesting objects that + + align:start position:0% +interesting objects that + + + align:start position:0% +interesting objects that +either collapse flat for uh + + align:start position:0% +either collapse flat for uh + + + align:start position:0% +either collapse flat for uh +transportation + + align:start position:0% +transportation + + + align:start position:0% +transportation +uh or transform like jason was talking + + align:start position:0% +uh or transform like jason was talking + + + align:start position:0% +uh or transform like jason was talking +about + + align:start position:0% +about + + + align:start position:0% +about +but i'm just giving you a flavor uh the + + align:start position:0% +but i'm just giving you a flavor uh the + + + align:start position:0% +but i'm just giving you a flavor uh the +i think the first paper we wrote + + align:start position:0% +i think the first paper we wrote + + + align:start position:0% +i think the first paper we wrote +together + + align:start position:0% +together + + + align:start position:0% +together +was on maize folding so this is an + + align:start position:0% +was on maize folding so this is an + + + align:start position:0% +was on maize folding so this is an +example of folding + + align:start position:0% +example of folding + + + align:start position:0% +example of folding +a maze from a rectangle of paper and you + + align:start position:0% +a maze from a rectangle of paper and you + + + align:start position:0% +a maze from a rectangle of paper and you +can all + + align:start position:0% +can all + + + align:start position:0% +can all +try this out you just + + align:start position:0% +try this out you just + + + align:start position:0% +try this out you just +google for our maze folder you can + + align:start position:0% +google for our maze folder you can + + + align:start position:0% +google for our maze folder you can +generate a random maze + + align:start position:0% +generate a random maze + + + align:start position:0% +generate a random maze +and this 3d structure can be folded + + align:start position:0% +and this 3d structure can be folded + + + align:start position:0% +and this 3d structure can be folded +from this crease pattern that's a really + + align:start position:0% +from this crease pattern that's a really + + + align:start position:0% +from this crease pattern that's a really +hard one so + + align:start position:0% +hard one so + + + align:start position:0% +hard one so +try maybe try something smaller you can + + align:start position:0% +try maybe try something smaller you can + + + align:start position:0% +try maybe try something smaller you can +also write your favorite message + + align:start position:0% +also write your favorite message + + + align:start position:0% +also write your favorite message +and fold this maze extruded graph + + align:start position:0% +and fold this maze extruded graph + + + align:start position:0% +and fold this maze extruded graph +from this crease pattern might want to + + align:start position:0% +from this crease pattern might want to + + + align:start position:0% +from this crease pattern might want to +start with something smaller + + align:start position:0% +start with something smaller + + + align:start position:0% +start with something smaller +but that's the general idea and it's + + align:start position:0% +but that's the general idea and it's + + + align:start position:0% +but that's the general idea and it's +actually quite easy to prove this + + align:start position:0% +actually quite easy to prove this + + + align:start position:0% +actually quite easy to prove this +algorithmically + + align:start position:0% +algorithmically + + + align:start position:0% +algorithmically +if you have a really good origamis like + + align:start position:0% +if you have a really good origamis like + + + align:start position:0% +if you have a really good origamis like +jason on your team + + align:start position:0% +jason on your team + + + align:start position:0% +jason on your team +what you do is design how to fold each + + align:start position:0% +what you do is design how to fold each + + + align:start position:0% +what you do is design how to fold each +type of vertex this is just a graph on a + + align:start position:0% +type of vertex this is just a graph on a + + + align:start position:0% +type of vertex this is just a graph on a +grid + + align:start position:0% +grid + + + align:start position:0% +grid +so there are you know some constant + + align:start position:0% +so there are you know some constant + + + align:start position:0% +so there are you know some constant +number of different ways that each + + align:start position:0% +number of different ways that each + + + align:start position:0% +number of different ways that each +vertex could look it could be degree + + align:start position:0% +vertex could look it could be degree + + + align:start position:0% +vertex could look it could be degree +four it could be degree three + + align:start position:0% +four it could be degree three + + + align:start position:0% +four it could be degree three +uh in as a t it could be degree two + + align:start position:0% +uh in as a t it could be degree two + + + align:start position:0% +uh in as a t it could be degree two +either as a turn or a straight + + align:start position:0% +either as a turn or a straight + + + align:start position:0% +either as a turn or a straight +and you design little gadgets little + + align:start position:0% +and you design little gadgets little + + + align:start position:0% +and you design little gadgets little +crease patterns that fold into each of + + align:start position:0% +crease patterns that fold into each of + + + align:start position:0% +crease patterns that fold into each of +those little structures + + align:start position:0% +those little structures + + + align:start position:0% +those little structures +and if you can do it in a way that these + + align:start position:0% +and if you can do it in a way that these + + + align:start position:0% +and if you can do it in a way that these +boundaries are compatible + + align:start position:0% +boundaries are compatible + + + align:start position:0% +boundaries are compatible +then to fold the whole thing you just + + align:start position:0% +then to fold the whole thing you just + + + align:start position:0% +then to fold the whole thing you just +sort of glue together those crease + + align:start position:0% +sort of glue together those crease + + + align:start position:0% +sort of glue together those crease +patterns and that's how that software + + align:start position:0% +patterns and that's how that software + + + align:start position:0% +patterns and that's how that software +works + + align:start position:0% +works + + + align:start position:0% +works +and so that was this is particularly + + align:start position:0% +and so that was this is particularly + + + align:start position:0% +and so that was this is particularly +interesting because you can fold an + + align:start position:0% +interesting because you can fold an + + + align:start position:0% +interesting because you can fold an +arbitrarily complicated graph + + align:start position:0% +arbitrarily complicated graph + + + align:start position:0% +arbitrarily complicated graph +uh arbitrarily complicated maze m by n + + align:start position:0% +uh arbitrarily complicated maze m by n + + + align:start position:0% +uh arbitrarily complicated maze m by n +with a + + align:start position:0% +with a + + + align:start position:0% +with a +constant scale factor as long as the + + align:start position:0% +constant scale factor as long as the + + + align:start position:0% +constant scale factor as long as the +height that you're extruding that maze + + align:start position:0% +height that you're extruding that maze + + + align:start position:0% +height that you're extruding that maze +is constant + + align:start position:0% +is constant + + + align:start position:0% +is constant +then this is one family of shapes we + + align:start position:0% +then this is one family of shapes we + + + align:start position:0% +then this is one family of shapes we +know how to fold really well + + align:start position:0% +know how to fold really well + + + align:start position:0% +know how to fold really well +in general we're trying to understand + + align:start position:0% +in general we're trying to understand + + + align:start position:0% +in general we're trying to understand +you know what makes + + align:start position:0% +you know what makes + + + align:start position:0% +you know what makes +this lobster a nice shape in that it can + + align:start position:0% +this lobster a nice shape in that it can + + + align:start position:0% +this lobster a nice shape in that it can +be represented with a not too large + + align:start position:0% +be represented with a not too large + + + align:start position:0% +be represented with a not too large +piece of paper and we don't have general + + align:start position:0% +piece of paper and we don't have general + + + align:start position:0% +piece of paper and we don't have general +answers to that + + align:start position:0% +answers to that + + + align:start position:0% +answers to that +that problem i think that was a + + align:start position:0% +that problem i think that was a + + + align:start position:0% +that problem i think that was a +whirlwind tour of computational origami + + align:start position:0% +whirlwind tour of computational origami + + + align:start position:0% +whirlwind tour of computational origami +i also play a lot in the + + align:start position:0% +i also play a lot in the + + + align:start position:0% +i also play a lot in the +in algorithmic sculpture one of the + + align:start position:0% +in algorithmic sculpture one of the + + + align:start position:0% +in algorithmic sculpture one of the +leading edges in comp + + align:start position:0% +leading edges in comp + + + align:start position:0% +leading edges in comp +in origami and origami math is + + align:start position:0% +in origami and origami math is + + + align:start position:0% +in origami and origami math is +understanding how curved creases work + + align:start position:0% +understanding how curved creases work + + + align:start position:0% +understanding how curved creases work +and one of our favorite models is this + + align:start position:0% +and one of our favorite models is this + + + align:start position:0% +and one of our favorite models is this +one where you fold concentric circles + + align:start position:0% +one where you fold concentric circles + + + align:start position:0% +one where you fold concentric circles +alternating mountain and valley + + align:start position:0% +alternating mountain and valley + + + align:start position:0% +alternating mountain and valley +cut a circular hole out and it folds + + align:start position:0% +cut a circular hole out and it folds + + + align:start position:0% +cut a circular hole out and it folds +into this kind of + + align:start position:0% +into this kind of + + + align:start position:0% +into this kind of +pringle shape as a nice physics + + align:start position:0% +pringle shape as a nice physics + + + align:start position:0% +pringle shape as a nice physics +equilibrium thing and then you can turn + + align:start position:0% +equilibrium thing and then you can turn + + + align:start position:0% +equilibrium thing and then you can turn +it into fun sculptures like + + align:start position:0% +it into fun sculptures like + + + align:start position:0% +it into fun sculptures like +this these are done with my dad martin + + align:start position:0% +this these are done with my dad martin + + + align:start position:0% +this these are done with my dad martin +domain + + align:start position:0% +domain + + + align:start position:0% +domain +who's also here at mit or this guy this + + align:start position:0% +who's also here at mit or this guy this + + + align:start position:0% +who's also here at mit or this guy this +paper has been printed with a pattern + + align:start position:0% +paper has been printed with a pattern + + + align:start position:0% +paper has been printed with a pattern +according to + + align:start position:0% +according to + + + align:start position:0% +according to +getting burned by glass and then it gets + + align:start position:0% +getting burned by glass and then it gets + + + align:start position:0% +getting burned by glass and then it gets +folded and then put inside + + align:start position:0% +folded and then put inside + + + align:start position:0% +folded and then put inside +glass also made here at mit + + align:start position:0% +glass also made here at mit + + + align:start position:0% +glass also made here at mit +uh and so we use sculpture to try to + + align:start position:0% +uh and so we use sculpture to try to + + + align:start position:0% +uh and so we use sculpture to try to +explore and understand intuitively how + + align:start position:0% +explore and understand intuitively how + + + align:start position:0% +explore and understand intuitively how +curve creases work and then we get + + align:start position:0% +curve creases work and then we get + + + align:start position:0% +curve creases work and then we get +better and better + + align:start position:0% +better and better + + + align:start position:0% +better and better +understanding of the mathematics of even + + align:start position:0% +understanding of the mathematics of even + + + align:start position:0% +understanding of the mathematics of even +we don't even know whether this surface + + align:start position:0% +we don't even know whether this surface + + + align:start position:0% +we don't even know whether this surface +exists whether it's possible to fold in + + align:start position:0% +exists whether it's possible to fold in + + + align:start position:0% +exists whether it's possible to fold in +this way although + + align:start position:0% +this way although + + + align:start position:0% +this way although +getting close to proving it uh + + align:start position:0% +getting close to proving it uh + + + align:start position:0% +getting close to proving it uh +so that was sort of in the top level of + + align:start position:0% +so that was sort of in the top level of + + + align:start position:0% +so that was sort of in the top level of +this + + align:start position:0% +this + + + align:start position:0% +this +hierarchy computational geometry is a + + align:start position:0% +hierarchy computational geometry is a + + + align:start position:0% +hierarchy computational geometry is a +bigger umbrella + + align:start position:0% +bigger umbrella + + + align:start position:0% +bigger umbrella +which is represented by another class + + align:start position:0% +which is represented by another class + + + align:start position:0% +which is represented by another class +6850 that's being taught this term + + align:start position:0% +6850 that's being taught this term + + + align:start position:0% +6850 that's being taught this term +and then i talked about geometric + + align:start position:0% +and then i talked about geometric + + + align:start position:0% +and then i talked about geometric +folding within that branch + + align:start position:0% +folding within that branch + + + align:start position:0% +folding within that branch +let me briefly tell you about another + + align:start position:0% +let me briefly tell you about another + + + align:start position:0% +let me briefly tell you about another +world of geometry very different + + align:start position:0% +world of geometry very different + + + align:start position:0% +world of geometry very different +in terms of model of computation oh i'm + + align:start position:0% +in terms of model of computation oh i'm + + + align:start position:0% +in terms of model of computation oh i'm +jumped ahead a little bit + + align:start position:0% +jumped ahead a little bit + + + align:start position:0% +jumped ahead a little bit +uh rewind let me show you one more fun + + align:start position:0% +uh rewind let me show you one more fun + + + align:start position:0% +uh rewind let me show you one more fun +demo + + align:start position:0% +demo + + + align:start position:0% +demo +which uh if i find my scissors + + align:start position:0% + + + + align:start position:0% + +so if i take a rectangle of paper and i + + align:start position:0% +so if i take a rectangle of paper and i + + + align:start position:0% +so if i take a rectangle of paper and i +fold it flat + + align:start position:0% +fold it flat + + + align:start position:0% +fold it flat +and make one straight cut what shapes + + align:start position:0% +and make one straight cut what shapes + + + align:start position:0% +and make one straight cut what shapes +can i get + + align:start position:0% +can i get + + + align:start position:0% +can i get +this is called the fold and cut problem + + align:start position:0% +this is called the fold and cut problem + + + align:start position:0% +this is called the fold and cut problem +hundreds of years old + + align:start position:0% +hundreds of years old + + + align:start position:0% +hundreds of years old +here for example i get a + + align:start position:0% +here for example i get a + + + align:start position:0% +here for example i get a +swan here i get + + align:start position:0% + + + + align:start position:0% + +one straight cut i unfold and get + + align:start position:0% +one straight cut i unfold and get + + + align:start position:0% +one straight cut i unfold and get +an angelfish tough audience + + align:start position:0% +an angelfish tough audience + + + align:start position:0% +an angelfish tough audience +today i keep going i've seen all these + + align:start position:0% +today i keep going i've seen all these + + + align:start position:0% +today i keep going i've seen all these +before + + align:start position:0% +before + + + align:start position:0% +before +this is this one is um a particularly + + align:start position:0% +this is this one is um a particularly + + + align:start position:0% +this is this one is um a particularly +difficult one to fold + + align:start position:0% +difficult one to fold + + + align:start position:0% +difficult one to fold +only full and to cut yeah + + align:start position:0% +only full and to cut yeah + + + align:start position:0% +only full and to cut yeah +okay hopefully that works well + + align:start position:0% + + + + align:start position:0% + +this is + + align:start position:0% + + + + align:start position:0% + +the mit logo + + align:start position:0% + + + + align:start position:0% + +yeah go mit all right so + + align:start position:0% +yeah go mit all right so + + + align:start position:0% +yeah go mit all right so +um that's that's actually the first + + align:start position:0% +um that's that's actually the first + + + align:start position:0% +um that's that's actually the first +problem i worked on in computational + + align:start position:0% +problem i worked on in computational + + + align:start position:0% +problem i worked on in computational +origami it's a lot of fun + + align:start position:0% +origami it's a lot of fun + + + align:start position:0% +origami it's a lot of fun +and there's a really interesting + + align:start position:0% +and there's a really interesting + + + align:start position:0% +and there's a really interesting +algorithm here also for computing + + align:start position:0% +algorithm here also for computing + + + align:start position:0% +algorithm here also for computing +the crease pattern how to fold your + + align:start position:0% +the crease pattern how to fold your + + + align:start position:0% +the crease pattern how to fold your +piece of paper to align + + align:start position:0% +piece of paper to align + + + align:start position:0% +piece of paper to align +in fact any graph you draw on a piece of + + align:start position:0% +in fact any graph you draw on a piece of + + + align:start position:0% +in fact any graph you draw on a piece of +paper + + align:start position:0% +paper + + + align:start position:0% +paper +you can align all those edges and + + align:start position:0% +you can align all those edges and + + + align:start position:0% +you can align all those edges and +nothing else so you cut along the line + + align:start position:0% +nothing else so you cut along the line + + + align:start position:0% +nothing else so you cut along the line +you get exactly what you want + + align:start position:0% +you get exactly what you want + + + align:start position:0% +you get exactly what you want +cool all right now i want to talk about + + align:start position:0% +cool all right now i want to talk about + + + align:start position:0% +cool all right now i want to talk about +something completely different which is + + align:start position:0% +something completely different which is + + + align:start position:0% +something completely different which is +self-assembly + + align:start position:0% +self-assembly + + + align:start position:0% +self-assembly +a fun thing you can do with dna which we + + align:start position:0% +a fun thing you can do with dna which we + + + align:start position:0% +a fun thing you can do with dna which we +all have + + align:start position:0% +all have + + + align:start position:0% +all have +just pick out some cool dna strands and + + align:start position:0% +just pick out some cool dna strands and + + + align:start position:0% +just pick out some cool dna strands and +design them in a clever way so they fit + + align:start position:0% +design them in a clever way so they fit + + + align:start position:0% +design them in a clever way so they fit +together to form a kind of square + + align:start position:0% +together to form a kind of square + + + align:start position:0% +together to form a kind of square +with dangling ends which i'll call glues + + align:start position:0% +with dangling ends which i'll call glues + + + align:start position:0% +with dangling ends which i'll call glues +and each of those dangling ends can have + + align:start position:0% +and each of those dangling ends can have + + + align:start position:0% +and each of those dangling ends can have +a particular pattern and only + + align:start position:0% +a particular pattern and only + + + align:start position:0% +a particular pattern and only +identical or complementary patterns will + + align:start position:0% +identical or complementary patterns will + + + align:start position:0% +identical or complementary patterns will +attach to each other + + align:start position:0% +attach to each other + + + align:start position:0% +attach to each other +and so you can use this to design your + + align:start position:0% +and so you can use this to design your + + + align:start position:0% +and so you can use this to design your +own self-assembling system + + align:start position:0% +own self-assembling system + + + align:start position:0% +own self-assembling system +like biology does but engineered for + + align:start position:0% +like biology does but engineered for + + + align:start position:0% +like biology does but engineered for +example to build a computer this is an + + align:start position:0% +example to build a computer this is an + + + align:start position:0% +example to build a computer this is an +example of taking a bunch of these + + align:start position:0% +example of taking a bunch of these + + + align:start position:0% +example of taking a bunch of these +square tiles + + align:start position:0% +square tiles + + + align:start position:0% +square tiles +and building a binary counter this thing + + align:start position:0% +and building a binary counter this thing + + + align:start position:0% +and building a binary counter this thing +is roughly counting in binary + + align:start position:0% +is roughly counting in binary + + + align:start position:0% +is roughly counting in binary +along the diagonal it's a little skewed + + align:start position:0% +along the diagonal it's a little skewed + + + align:start position:0% +along the diagonal it's a little skewed +so it's hard to see + + align:start position:0% +so it's hard to see + + + align:start position:0% +so it's hard to see +but the general model is + + align:start position:0% +but the general model is + + + align:start position:0% +but the general model is +you have + + align:start position:0% + + + + align:start position:0% + +squares this is sort of the + + align:start position:0% +squares this is sort of the + + + align:start position:0% +squares this is sort of the +computational model + + align:start position:0% +computational model + + + align:start position:0% +computational model +with four different glues and you can + + align:start position:0% +with four different glues and you can + + + align:start position:0% +with four different glues and you can +build any square you want + + align:start position:0% +build any square you want + + + align:start position:0% +build any square you want +but you don't have very many of these + + align:start position:0% +but you don't have very many of these + + + align:start position:0% +but you don't have very many of these +different glues ideally + + align:start position:0% +different glues ideally + + + align:start position:0% +different glues ideally +and then if you have two tiles with + + align:start position:0% +and then if you have two tiles with + + + align:start position:0% +and then if you have two tiles with +complementary glues they'll want to + + align:start position:0% +complementary glues they'll want to + + + align:start position:0% +complementary glues they'll want to +match together but it depends how strong + + align:start position:0% +match together but it depends how strong + + + align:start position:0% +match together but it depends how strong +this glue + + align:start position:0% +this glue + + + align:start position:0% +this glue +is how much affinity there is for how + + align:start position:0% +is how much affinity there is for how + + + align:start position:0% +is how much affinity there is for how +long those dna dangling ends are + + align:start position:0% +long those dna dangling ends are + + + align:start position:0% +long those dna dangling ends are +and also the temperature of your system + + align:start position:0% +and also the temperature of your system + + + align:start position:0% +and also the temperature of your system +if you have really high temperature + + align:start position:0% +if you have really high temperature + + + align:start position:0% +if you have really high temperature +nothing will stick together + + align:start position:0% +nothing will stick together + + + align:start position:0% +nothing will stick together +low temperature things will stick + + align:start position:0% +low temperature things will stick + + + align:start position:0% +low temperature things will stick +together even if they're not supposed to + + align:start position:0% +together even if they're not supposed to + + + align:start position:0% +together even if they're not supposed to +and so you can if you tune your system + + align:start position:0% +and so you can if you tune your system + + + align:start position:0% +and so you can if you tune your system +really well + + align:start position:0% +really well + + + align:start position:0% +really well +you can design uh a system so that maybe + + align:start position:0% +you can design uh a system so that maybe + + + align:start position:0% +you can design uh a system so that maybe +these guys + + align:start position:0% +these guys + + + align:start position:0% +these guys +these glues are really strong and so + + align:start position:0% +these glues are really strong and so + + + align:start position:0% +these glues are really strong and so +let's + + align:start position:0% +let's + + + align:start position:0% +let's +i don't know right e here eric + + align:start position:0% +i don't know right e here eric + + + align:start position:0% +i don't know right e here eric +and so these tiles will always glue + + align:start position:0% +and so these tiles will always glue + + + align:start position:0% +and so these tiles will always glue +together but only when all three of + + align:start position:0% +together but only when all three of + + + align:start position:0% +together but only when all three of +these + + align:start position:0% +these + + + align:start position:0% +these +are glued together can this tile which + + align:start position:0% +are glued together can this tile which + + + align:start position:0% +are glued together can this tile which +has c + + align:start position:0% +has c + + + align:start position:0% +has c +complement and f complement + + align:start position:0% +complement and f complement + + + align:start position:0% +complement and f complement +then it will if you set the temperatures + + align:start position:0% +then it will if you set the temperatures + + + align:start position:0% +then it will if you set the temperatures +just right only because both of these + + align:start position:0% +just right only because both of these + + + align:start position:0% +just right only because both of these +edges match + + align:start position:0% +edges match + + + align:start position:0% +edges match +will this style be able to come in and + + align:start position:0% +will this style be able to come in and + + + align:start position:0% +will this style be able to come in and +that's the basis for that + + align:start position:0% +that's the basis for that + + + align:start position:0% +that's the basis for that +building that binary counter and so this + + align:start position:0% +building that binary counter and so this + + + align:start position:0% +building that binary counter and so this +is a very different model of computation + + align:start position:0% +is a very different model of computation + + + align:start position:0% +is a very different model of computation +from what we're used to in this class + + align:start position:0% +from what we're used to in this class + + + align:start position:0% +from what we're used to in this class +where you think of instructions and they + + align:start position:0% +where you think of instructions and they + + + align:start position:0% +where you think of instructions and they +run one at a time here the + + align:start position:0% +run one at a time here the + + + align:start position:0% +run one at a time here the +model of computation is geometric it's + + align:start position:0% +model of computation is geometric it's + + + align:start position:0% +model of computation is geometric it's +these squares that are just floating + + align:start position:0% +these squares that are just floating + + + align:start position:0% +these squares that are just floating +around + + align:start position:0% +around + + + align:start position:0% +around +and gluing together and so your program + + align:start position:0% +and gluing together and so your program + + + align:start position:0% +and gluing together and so your program +at any moment is some + + align:start position:0% +at any moment is some + + + align:start position:0% +at any moment is some +conglomerate of squares and so i just + + align:start position:0% +conglomerate of squares and so i just + + + align:start position:0% +conglomerate of squares and so i just +wanted to mention it because it's a + + align:start position:0% +wanted to mention it because it's a + + + align:start position:0% +wanted to mention it because it's a +really fun model + + align:start position:0% +really fun model + + + align:start position:0% +really fun model +you can prove cool things in this model + + align:start position:0% +you can prove cool things in this model + + + align:start position:0% +you can prove cool things in this model +like how to build any shape + + align:start position:0% +like how to build any shape + + + align:start position:0% +like how to build any shape +by a sequence of pores mixings between + + align:start position:0% +by a sequence of pores mixings between + + + align:start position:0% +by a sequence of pores mixings between +tiles + + align:start position:0% +tiles + + + align:start position:0% +tiles +that you can execute in parallel and so + + align:start position:0% +that you can execute in parallel and so + + + align:start position:0% +that you can execute in parallel and so +it only takes log n time + + align:start position:0% +it only takes log n time + + + align:start position:0% +it only takes log n time +in parallel steps a linear number of + + align:start position:0% +in parallel steps a linear number of + + + align:start position:0% +in parallel steps a linear number of +different mix + + align:start position:0% +different mix + + + align:start position:0% +different mix +operations to make an arbitrary shape + + align:start position:0% +operations to make an arbitrary shape + + + align:start position:0% +operations to make an arbitrary shape +even using + + align:start position:0% +even using + + + align:start position:0% +even using +a constant number of different glues + + align:start position:0% +a constant number of different glues + + + align:start position:0% +a constant number of different glues +which is + + align:start position:0% +which is + + + align:start position:0% +which is +cool and may be practical + + align:start position:0% +cool and may be practical + + + align:start position:0% +cool and may be practical +you can also use it to build a + + align:start position:0% +you can also use it to build a + + + align:start position:0% +you can also use it to build a +replicator where you're given an object + + align:start position:0% +replicator where you're given an object + + + align:start position:0% +replicator where you're given an object +like this + + align:start position:0% +like this + + + align:start position:0% +like this +that you don't know the shape of like we + + align:start position:0% +that you don't know the shape of like we + + + align:start position:0% +that you don't know the shape of like we +don't know whether this exists + + align:start position:0% +don't know whether this exists + + + align:start position:0% +don't know whether this exists +and we can't model it mathematically + + align:start position:0% +and we can't model it mathematically + + + align:start position:0% +and we can't model it mathematically +very well and you would stick it in a + + align:start position:0% +very well and you would stick it in a + + + align:start position:0% +very well and you would stick it in a +vat and all these tiles would attach and + + align:start position:0% +vat and all these tiles would attach and + + + align:start position:0% +vat and all these tiles would attach and +basically build a mold + + align:start position:0% +basically build a mold + + + align:start position:0% +basically build a mold +and then start photocopying in 3d that + + align:start position:0% +and then start photocopying in 3d that + + + align:start position:0% +and then start photocopying in 3d that +mold and you can build that + + align:start position:0% +mold and you can build that + + + align:start position:0% +mold and you can build that +with a system with only two steps i + + align:start position:0% +with a system with only two steps i + + + align:start position:0% +with a system with only two steps i +believe + + align:start position:0% +believe + + + align:start position:0% +believe +and a constant number of tile types and + + align:start position:0% +and a constant number of tile types and + + + align:start position:0% +and a constant number of tile types and +it does all of that + + align:start position:0% +it does all of that + + + align:start position:0% +it does all of that +in this model in constant time in + + align:start position:0% +in this model in constant time in + + + align:start position:0% +in this model in constant time in +reality you'd have to feed this machine + + align:start position:0% +reality you'd have to feed this machine + + + align:start position:0% +reality you'd have to feed this machine +and wait for it to print out all these + + align:start position:0% +and wait for it to print out all these + + + align:start position:0% +and wait for it to print out all these +things and and these experiments take + + align:start position:0% +things and and these experiments take + + + align:start position:0% +things and and these experiments take +hours if not days to run but in theory + + align:start position:0% +hours if not days to run but in theory + + + align:start position:0% +hours if not days to run but in theory +it's really cool and you get some really + + align:start position:0% +it's really cool and you get some really + + + align:start position:0% +it's really cool and you get some really +fun models and very general results + + align:start position:0% +fun models and very general results + + + align:start position:0% +fun models and very general results +you can also use it to build a + + align:start position:0% +you can also use it to build a + + + align:start position:0% +you can also use it to build a +miniaturizer or a magnifier and + + align:start position:0% +miniaturizer or a magnifier and + + + align:start position:0% +miniaturizer or a magnifier and +other other fun stuff okay + + align:start position:0% +other other fun stuff okay + + + align:start position:0% +other other fun stuff okay +um so that was a brief tour of + + align:start position:0% +um so that was a brief tour of + + + align:start position:0% +um so that was a brief tour of +computational geometry + + align:start position:0% +computational geometry + + + align:start position:0% +computational geometry +i work mostly in four different areas of + + align:start position:0% +i work mostly in four different areas of + + + align:start position:0% +i work mostly in four different areas of +algorithms + + align:start position:0% +algorithms + + + align:start position:0% +algorithms +geometry data structures graph + + align:start position:0% +geometry data structures graph + + + align:start position:0% +geometry data structures graph +algorithms and what i call recreational + + align:start position:0% +algorithms and what i call recreational + + + align:start position:0% +algorithms and what i call recreational +algorithms + + align:start position:0% +algorithms + + + align:start position:0% +algorithms +i think i made up that term and + + align:start position:0% +i think i made up that term and + + + align:start position:0% +i think i made up that term and +let's go into data structures which is + + align:start position:0% +let's go into data structures which is + + + align:start position:0% +let's go into data structures which is +represented by this class 6851 + + align:start position:0% +represented by this class 6851 + + + align:start position:0% +represented by this class 6851 +all of the classes i mentioned have + + align:start position:0% +all of the classes i mentioned have + + + align:start position:0% +all of the classes i mentioned have +online video lectures so especially for + + align:start position:0% +online video lectures so especially for + + + align:start position:0% +online video lectures so especially for +those + + align:start position:0% +those + + + align:start position:0% +those +watching at home on opencourseware most + + align:start position:0% +watching at home on opencourseware most + + + align:start position:0% +watching at home on opencourseware most +of these classes are on opencourseware + + align:start position:0% +of these classes are on opencourseware + + + align:start position:0% +of these classes are on opencourseware +and if not + + align:start position:0% +and if not + + + align:start position:0% +and if not +they're on my webpage so 6851 advanced + + align:start position:0% +they're on my webpage so 6851 advanced + + + align:start position:0% +they're on my webpage so 6851 advanced +data structures + + align:start position:0% +data structures + + + align:start position:0% +data structures +is an extension of the sorts of data + + align:start position:0% +is an extension of the sorts of data + + + align:start position:0% +is an extension of the sorts of data +structures you've seen in + + align:start position:0% +structures you've seen in + + + align:start position:0% +structures you've seen in +here in 06 and the ones you will see in + + align:start position:0% +here in 06 and the ones you will see in + + + align:start position:0% +here in 06 and the ones you will see in + + align:start position:0% + + + align:start position:0% +i thought i'd give you a flavor of one + + align:start position:0% +i thought i'd give you a flavor of one + + + align:start position:0% +i thought i'd give you a flavor of one +such result + + align:start position:0% + + + + align:start position:0% + +which is + + align:start position:0% + + + + align:start position:0% + +a problem we've seen in this class + + align:start position:0% +a problem we've seen in this class + + + align:start position:0% +a problem we've seen in this class +done better so suppose you want to store + + align:start position:0% +done better so suppose you want to store + + + align:start position:0% +done better so suppose you want to store +a dynamic ordered set + + align:start position:0% + + + + align:start position:0% + +so this is the set interface dynamic in + + align:start position:0% +so this is the set interface dynamic in + + + align:start position:0% +so this is the set interface dynamic in +the sense that i have + + align:start position:0% +the sense that i have + + + align:start position:0% +the sense that i have +insert and delete + + align:start position:0% + + + + align:start position:0% + +and ordered in the sense that i want to + + align:start position:0% +and ordered in the sense that i want to + + + align:start position:0% +and ordered in the sense that i want to +support find next and finds previous + + align:start position:0% + + + + align:start position:0% + +okay so exactly which subset of the set + + align:start position:0% +okay so exactly which subset of the set + + + align:start position:0% +okay so exactly which subset of the set +interface you choose + + align:start position:0% +interface you choose + + + align:start position:0% +interface you choose +influences what what data structure + + align:start position:0% +influences what what data structure + + + align:start position:0% +influences what what data structure +you've seen we've seen for dynamic sets + + align:start position:0% +you've seen we've seen for dynamic sets + + + align:start position:0% +you've seen we've seen for dynamic sets +you want to use + + align:start position:0% +you want to use + + + align:start position:0% +you want to use +hashing if you don't care about find + + align:start position:0% +hashing if you don't care about find + + + align:start position:0% +hashing if you don't care about find +next if you just care about + + align:start position:0% +next if you just care about + + + align:start position:0% +next if you just care about +find then hashing is great constant + + align:start position:0% +find then hashing is great constant + + + align:start position:0% +find then hashing is great constant +expected + + align:start position:0% +expected + + + align:start position:0% +expected +you can prove stronger things about + + align:start position:0% +you can prove stronger things about + + + align:start position:0% +you can prove stronger things about +hashing we do in that class + + align:start position:0% +hashing we do in that class + + + align:start position:0% +hashing we do in that class +but if you want dynamic and ordered + + align:start position:0% +but if you want dynamic and ordered + + + align:start position:0% +but if you want dynamic and ordered +you cannot do constant time for + + align:start position:0% +you cannot do constant time for + + + align:start position:0% +you cannot do constant time for +operation you can prove that + + align:start position:0% +operation you can prove that + + + align:start position:0% +operation you can prove that +which is cool but and so what data + + align:start position:0% +which is cool but and so what data + + + align:start position:0% +which is cool but and so what data +structure have we seen that solves this + + align:start position:0% +structure have we seen that solves this + + + align:start position:0% +structure have we seen that solves this +problem + + align:start position:0% +problem + + + align:start position:0% +problem +pretty well set avl trees which solve + + align:start position:0% +pretty well set avl trees which solve + + + align:start position:0% +pretty well set avl trees which solve +everything + + align:start position:0% +everything + + + align:start position:0% +everything +in log n so log n + + align:start position:0% +in log n so log n + + + align:start position:0% +in log n so log n +one competitor + + align:start position:0% + + + + align:start position:0% + +yeah i am interested in this in the + + align:start position:0% +yeah i am interested in this in the + + + align:start position:0% +yeah i am interested in this in the +word ram model + + align:start position:0% +word ram model + + + align:start position:0% +word ram model +which is the only model we've seen in + + align:start position:0% +which is the only model we've seen in + + + align:start position:0% +which is the only model we've seen in +this class this happens to work in a + + align:start position:0% +this class this happens to work in a + + + align:start position:0% +this class this happens to work in a +stronger model + + align:start position:0% +stronger model + + + align:start position:0% +stronger model +um and we can do better than log n + + align:start position:0% +um and we can do better than log n + + + align:start position:0% +um and we can do better than log n +in the following it'll take me a while + + align:start position:0% +in the following it'll take me a while + + + align:start position:0% +in the following it'll take me a while +before i get better but here's at least + + align:start position:0% +before i get better but here's at least + + + align:start position:0% +before i get better but here's at least +a different bound we can get + + align:start position:0% +a different bound we can get + + + align:start position:0% +a different bound we can get +log w uh this is via a structure called + + align:start position:0% +log w uh this is via a structure called + + + align:start position:0% +log w uh this is via a structure called +venom nubos + + align:start position:0% + + + + align:start position:0% + +who's a person avl is two people + + align:start position:0% +who's a person avl is two people + + + align:start position:0% +who's a person avl is two people +ben under both i've actually met so log + + align:start position:0% +ben under both i've actually met so log + + + align:start position:0% +ben under both i've actually met so log +w + + align:start position:0% +w + + + align:start position:0% +w +remember w is our word size so this is a + + align:start position:0% +remember w is our word size so this is a + + + align:start position:0% +remember w is our word size so this is a +bit of a weird running time it's great + + align:start position:0% +bit of a weird running time it's great + + + align:start position:0% +bit of a weird running time it's great +if w is like log n + + align:start position:0% +if w is like log n + + + align:start position:0% +if w is like log n +then this is log log n and we know w is + + align:start position:0% +then this is log log n and we know w is + + + align:start position:0% +then this is log log n and we know w is +at least log n but it could be bigger + + align:start position:0% +at least log n but it could be bigger + + + align:start position:0% +at least log n but it could be bigger +we don't really have a sense of how big + + align:start position:0% +we don't really have a sense of how big + + + align:start position:0% +we don't really have a sense of how big +w can get maybe it's even + + align:start position:0% +w can get maybe it's even + + + align:start position:0% +w can get maybe it's even +n maybe it's big and then these are the + + align:start position:0% +n maybe it's big and then these are the + + + align:start position:0% +n maybe it's big and then these are the +same maybe it's bigger than n + + align:start position:0% +same maybe it's bigger than n + + + align:start position:0% +same maybe it's bigger than n +and then this is maybe worse but for + + align:start position:0% +and then this is maybe worse but for + + + align:start position:0% +and then this is maybe worse but for +most w's this is actually + + align:start position:0% +most w's this is actually + + + align:start position:0% +most w's this is actually +pretty good and indeed optimal + + align:start position:0% +pretty good and indeed optimal + + + align:start position:0% +pretty good and indeed optimal +but it's not strictly better in any + + align:start position:0% +but it's not strictly better in any + + + align:start position:0% +but it's not strictly better in any +sense yet on the other hand + + align:start position:0% +sense yet on the other hand + + + align:start position:0% +sense yet on the other hand +there's another data structure which + + align:start position:0% +there's another data structure which + + + align:start position:0% +there's another data structure which +runs in log n divided by log w + + align:start position:0% +runs in log n divided by log w + + + align:start position:0% +runs in log n divided by log w +this is called fusion trees this was + + align:start position:0% +this is called fusion trees this was + + + align:start position:0% +this is called fusion trees this was +invented around the time that cold + + align:start position:0% +invented around the time that cold + + + align:start position:0% +invented around the time that cold +fusion was in the news and so + + align:start position:0% +fusion was in the news and so + + + align:start position:0% +fusion was in the news and so +they wanted data structures to represent + + align:start position:0% +they wanted data structures to represent + + + align:start position:0% +they wanted data structures to represent +and so we can achieve this bound or we + + align:start position:0% +and so we can achieve this bound or we + + + align:start position:0% +and so we can achieve this bound or we +can achieve this bound + + align:start position:0% +can achieve this bound + + + align:start position:0% +can achieve this bound +and this bound as good is if w is large + + align:start position:0% +and this bound as good is if w is large + + + align:start position:0% +and this bound as good is if w is large +this bound is good if w is small and so + + align:start position:0% +this bound is good if w is small and so + + + align:start position:0% +this bound is good if w is small and so +you can always take the min + + align:start position:0% +you can always take the min + + + align:start position:0% +you can always take the min +of the two whatever's better and in + + align:start position:0% +of the two whatever's better and in + + + align:start position:0% +of the two whatever's better and in +particular + + align:start position:0% +particular + + + align:start position:0% +particular +the min + + align:start position:0% +the min + + + align:start position:0% +the min +uh the min of those two things + + align:start position:0% +uh the min of those two things + + + align:start position:0% +uh the min of those two things +is at most i think it's square root log + + align:start position:0% +is at most i think it's square root log + + + align:start position:0% +is at most i think it's square root log +n over log log n + + align:start position:0% +n over log log n + + + align:start position:0% +n over log log n +if you want to bound just in terms of n + + align:start position:0% +if you want to bound just in terms of n + + + align:start position:0% +if you want to bound just in terms of n +then the crossover point between these + + align:start position:0% +then the crossover point between these + + + align:start position:0% +then the crossover point between these +two is this place and so you're always + + align:start position:0% +two is this place and so you're always + + + align:start position:0% +two is this place and so you're always +at most this which is + + align:start position:0% +at most this which is + + + align:start position:0% +at most this which is +quite a bit better than the log n of avl + + align:start position:0% +quite a bit better than the log n of avl + + + align:start position:0% +quite a bit better than the log n of avl +we've got a square root + + align:start position:0% +we've got a square root + + + align:start position:0% +we've got a square root +and we've got a slight thing in the + + align:start position:0% +and we've got a slight thing in the + + + align:start position:0% +and we've got a slight thing in the +denominator pretty tiny + + align:start position:0% +denominator pretty tiny + + + align:start position:0% +denominator pretty tiny +but the big thing is the square root and + + align:start position:0% +but the big thing is the square root and + + + align:start position:0% +but the big thing is the square root and +that's kind of cool and it turns out + + align:start position:0% +that's kind of cool and it turns out + + + align:start position:0% +that's kind of cool and it turns out +that's + + align:start position:0% +that's + + + align:start position:0% +that's +pretty much optimal in terms of an n + + align:start position:0% +pretty much optimal in terms of an n + + + align:start position:0% +pretty much optimal in terms of an n +bound this is optimal + + align:start position:0% +bound this is optimal + + + align:start position:0% +bound this is optimal +the min of these two in general is + + align:start position:0% +the min of these two in general is + + + align:start position:0% +the min of these two in general is +roughly optimal up to like log log terms + + align:start position:0% +roughly optimal up to like log log terms + + + align:start position:0% +roughly optimal up to like log log terms +i for fun + + align:start position:0% +i for fun + + + align:start position:0% +i for fun +i threw up the actual formula for the + + align:start position:0% +i threw up the actual formula for the + + + align:start position:0% +i threw up the actual formula for the +right bound + + align:start position:0% +right bound + + + align:start position:0% +right bound +uh which is tight up to constant factors + + align:start position:0% +uh which is tight up to constant factors + + + align:start position:0% +uh which is tight up to constant factors +there's matching upper and lower bounds + + align:start position:0% +there's matching upper and lower bounds + + + align:start position:0% +there's matching upper and lower bounds +which we talk about it's min of three + + align:start position:0% +which we talk about it's min of three + + + align:start position:0% +which we talk about it's min of three +things + + align:start position:0% +things + + + align:start position:0% +things +four things uh including log of w over a + + align:start position:0% +four things uh including log of w over a + + + align:start position:0% +four things uh including log of w over a +divided by log of log w over a over log + + align:start position:0% +divided by log of log w over a over log + + + align:start position:0% +divided by log of log w over a over log +of log n over a + + align:start position:0% +of log n over a + + + align:start position:0% +of log n over a +uh that's the last term that i just read + + align:start position:0% +uh that's the last term that i just read + + + align:start position:0% +uh that's the last term that i just read +is messy + + align:start position:0% +is messy + + + align:start position:0% +is messy +uh surprisingly that is the right answer + + align:start position:0% +uh surprisingly that is the right answer + + + align:start position:0% +uh surprisingly that is the right answer +for this very + + align:start position:0% +for this very + + + align:start position:0% +for this very +particular problem a very natural + + align:start position:0% +particular problem a very natural + + + align:start position:0% +particular problem a very natural +problem + + align:start position:0% +problem + + + align:start position:0% +problem +uh a is the log of the space you're + + align:start position:0% +uh a is the log of the space you're + + + align:start position:0% +uh a is the log of the space you're +using + + align:start position:0% +using + + + align:start position:0% +using +so it's the address size uh good + + align:start position:0% +so it's the address size uh good + + + align:start position:0% +so it's the address size uh good +question + + align:start position:0% +question + + + align:start position:0% +question +um if you throw so it depends if you + + align:start position:0% +um if you throw so it depends if you + + + align:start position:0% +um if you throw so it depends if you +have a polynomial space data structure + + align:start position:0% +have a polynomial space data structure + + + align:start position:0% +have a polynomial space data structure +then basically + + align:start position:0% +then basically + + + align:start position:0% +then basically +these are optimal and this is + + align:start position:0% +these are optimal and this is + + + align:start position:0% +these are optimal and this is +generalizing to beyond that + + align:start position:0% +generalizing to beyond that + + + align:start position:0% +generalizing to beyond that +maybe you have a little bit more than + + align:start position:0% +maybe you have a little bit more than + + + align:start position:0% +maybe you have a little bit more than +polynomial space + + align:start position:0% +polynomial space + + + align:start position:0% +polynomial space +cool um so that's data structures + + align:start position:0% +cool um so that's data structures + + + align:start position:0% +cool um so that's data structures +i'm going to jump ahead to graph + + align:start position:0% +i'm going to jump ahead to graph + + + align:start position:0% +i'm going to jump ahead to graph +algorithms + + align:start position:0% +algorithms + + + align:start position:0% +algorithms +which if you want to take this class i + + align:start position:0% +which if you want to take this class i + + + align:start position:0% +which if you want to take this class i +recommend a time travel device + + align:start position:0% +recommend a time travel device + + + align:start position:0% +recommend a time travel device +go back to fall 2011 it may never get + + align:start position:0% +go back to fall 2011 it may never get + + + align:start position:0% +go back to fall 2011 it may never get +taught again but + + align:start position:0% +taught again but + + + align:start position:0% +taught again but +it has videos so you can watch instead + + align:start position:0% +it has videos so you can watch instead + + + align:start position:0% +it has videos so you can watch instead +of time traveling + + align:start position:0% +of time traveling + + + align:start position:0% +of time traveling +if you don't want to watch it live you + + align:start position:0% +if you don't want to watch it live you + + + align:start position:0% +if you don't want to watch it live you +can just watch the recorded version + + align:start position:0% +can just watch the recorded version + + + align:start position:0% +can just watch the recorded version +it was taught by a bunch of postdocs + + align:start position:0% +it was taught by a bunch of postdocs + + + align:start position:0% +it was taught by a bunch of postdocs +that were here uh and and + + align:start position:0% +that were here uh and and + + + align:start position:0% +that were here uh and and +myself uh and so what i like to do with + + align:start position:0% +myself uh and so what i like to do with + + + align:start position:0% +myself uh and so what i like to do with +graphs + + align:start position:0% +graphs + + + align:start position:0% +graphs +is the world of planar graphs or near + + align:start position:0% +is the world of planar graphs or near + + + align:start position:0% +is the world of planar graphs or near +planar graphs + + align:start position:0% + + + + align:start position:0% + +so we've talked a lot about this class + + align:start position:0% +so we've talked a lot about this class + + + align:start position:0% +so we've talked a lot about this class +algorithms that work for arbitrary + + align:start position:0% +algorithms that work for arbitrary + + + align:start position:0% +algorithms that work for arbitrary +graphs + + align:start position:0% +graphs + + + align:start position:0% +graphs +and the algorithms we've seen in this + + align:start position:0% +and the algorithms we've seen in this + + + align:start position:0% +and the algorithms we've seen in this +class are pretty much the best we know + + align:start position:0% +class are pretty much the best we know + + + align:start position:0% +class are pretty much the best we know +for a lot of problems for + + align:start position:0% +for a lot of problems for + + + align:start position:0% +for a lot of problems for +for arbitrary graphs but if your graph + + align:start position:0% +for arbitrary graphs but if your graph + + + align:start position:0% +for arbitrary graphs but if your graph +has some structure like + + align:start position:0% +has some structure like + + + align:start position:0% +has some structure like +it's a road network and there aren't too + + align:start position:0% +it's a road network and there aren't too + + + align:start position:0% +it's a road network and there aren't too +many overpasses you can usually + + align:start position:0% +many overpasses you can usually + + + align:start position:0% +many overpasses you can usually +draw these graphs in the plane without + + align:start position:0% +draw these graphs in the plane without + + + align:start position:0% +draw these graphs in the plane without +crossings that's the meaning of planar + + align:start position:0% +crossings that's the meaning of planar + + + align:start position:0% +crossings that's the meaning of planar +maybe not exactly maybe just a few + + align:start position:0% +maybe not exactly maybe just a few + + + align:start position:0% +maybe not exactly maybe just a few +crossings there's a generalization of + + align:start position:0% +crossings there's a generalization of + + + align:start position:0% +crossings there's a generalization of +this which i won't get into + + align:start position:0% +this which i won't get into + + + align:start position:0% +this which i won't get into +but let's just think about planar graphs + + align:start position:0% +but let's just think about planar graphs + + + align:start position:0% +but let's just think about planar graphs +planar graphs have some nice features + + align:start position:0% +planar graphs have some nice features + + + align:start position:0% +planar graphs have some nice features +like + + align:start position:0% +like + + + align:start position:0% +like +they always have a linear number of + + align:start position:0% +they always have a linear number of + + + align:start position:0% +they always have a linear number of +edges they're always sparse + + align:start position:0% + + + + align:start position:0% + +so you can immediately plug that into + + align:start position:0% +so you can immediately plug that into + + + align:start position:0% +so you can immediately plug that into +our existing bounds but even so you know + + align:start position:0% +our existing bounds but even so you know + + + align:start position:0% +our existing bounds but even so you know +dijkstra + + align:start position:0% +dijkstra + + + align:start position:0% +dijkstra +uh this would take in this such a graph + + align:start position:0% +uh this would take in this such a graph + + + align:start position:0% +uh this would take in this such a graph +would take + + align:start position:0% +would take + + + align:start position:0% +would take +v log v time for planar graphs you can + + align:start position:0% +v log v time for planar graphs you can + + + align:start position:0% +v log v time for planar graphs you can +do + + align:start position:0% +do + + + align:start position:0% +do +the equivalent of dijkstra meaning i can + + align:start position:0% +the equivalent of dijkstra meaning i can + + + align:start position:0% +the equivalent of dijkstra meaning i can +compute single source shortest paths + + align:start position:0% +compute single source shortest paths + + + align:start position:0% +compute single source shortest paths +with non-negative edge weights + + align:start position:0% +with non-negative edge weights + + + align:start position:0% +with non-negative edge weights +in linear time + + align:start position:0% + + + + align:start position:0% + +no log okay not that impressive but + + align:start position:0% +no log okay not that impressive but + + + align:start position:0% +no log okay not that impressive but +remove a log more impressive is we can + + align:start position:0% +remove a log more impressive is we can + + + align:start position:0% +remove a log more impressive is we can +do the equivalent of bellman ford + + align:start position:0% +do the equivalent of bellman ford + + + align:start position:0% +do the equivalent of bellman ford +uh which is single source shortest paths + + align:start position:0% +uh which is single source shortest paths + + + align:start position:0% +uh which is single source shortest paths +with arbitrary edge weights + + align:start position:0% +with arbitrary edge weights + + + align:start position:0% +with arbitrary edge weights +in a planar graph in uh + + align:start position:0% +in a planar graph in uh + + + align:start position:0% +in a planar graph in uh +sometime almost linear time + + align:start position:0% +sometime almost linear time + + + align:start position:0% +sometime almost linear time +v log squared v over + + align:start position:0% +v log squared v over + + + align:start position:0% +v log squared v over +log log v okay so there's a couple log + + align:start position:0% +log log v okay so there's a couple log + + + align:start position:0% +log log v okay so there's a couple log +factors here + + align:start position:0% +factors here + + + align:start position:0% +factors here +but for the almost linear time whereas + + align:start position:0% +but for the almost linear time whereas + + + align:start position:0% +but for the almost linear time whereas +bellman ford would take v squared time + + align:start position:0% +bellman ford would take v squared time + + + align:start position:0% +bellman ford would take v squared time +so this is a huge improvement over what + + align:start position:0% +so this is a huge improvement over what + + + align:start position:0% +so this is a huge improvement over what +we've seen in the class + + align:start position:0% +we've seen in the class + + + align:start position:0% +we've seen in the class +these are quite complicated algorithms + + align:start position:0% +these are quite complicated algorithms + + + align:start position:0% +these are quite complicated algorithms +but they're covered in that class if + + align:start position:0% +but they're covered in that class if + + + align:start position:0% +but they're covered in that class if +you're interested in them + + align:start position:0% +you're interested in them + + + align:start position:0% +you're interested in them +then the the area i work in a lot is + + align:start position:0% +then the the area i work in a lot is + + + align:start position:0% +then the the area i work in a lot is +approximation algorithms for + + align:start position:0% +approximation algorithms for + + + align:start position:0% +approximation algorithms for +planar graphs and let me just give you a + + align:start position:0% +planar graphs and let me just give you a + + + align:start position:0% +planar graphs and let me just give you a +fun + + align:start position:0% +fun + + + align:start position:0% +fun +flavor using something we know which is + + align:start position:0% +flavor using something we know which is + + + align:start position:0% +flavor using something we know which is +uh breadth first search + + align:start position:0% +uh breadth first search + + + align:start position:0% +uh breadth first search +so breadth research you can think of as + + align:start position:0% +so breadth research you can think of as + + + align:start position:0% +so breadth research you can think of as +building these sort of rings around + + align:start position:0% +building these sort of rings around + + + align:start position:0% +building these sort of rings around +a single root node + + align:start position:0% + + + + align:start position:0% + +and there's this general approach as + + align:start position:0% +and there's this general approach as + + + align:start position:0% +and there's this general approach as +introduced by baker in 1994 + + align:start position:0% +introduced by baker in 1994 + + + align:start position:0% +introduced by baker in 1994 +we've used for lots of different + + align:start position:0% +we've used for lots of different + + + align:start position:0% +we've used for lots of different +problems you want to solve some + + align:start position:0% +problems you want to solve some + + + align:start position:0% +problems you want to solve some +np hard problem on on a graph so just + + align:start position:0% +np hard problem on on a graph so just + + + align:start position:0% +np hard problem on on a graph so just +run + + align:start position:0% +run + + + align:start position:0% +run +breadth first search from an arbitrary + + align:start position:0% +breadth first search from an arbitrary + + + align:start position:0% +breadth first search from an arbitrary +vertex and decompose your graph into + + align:start position:0% +vertex and decompose your graph into + + + align:start position:0% +vertex and decompose your graph into +these layers + + align:start position:0% +these layers + + + align:start position:0% +these layers +you could number them you know zero one + + align:start position:0% +you could number them you know zero one + + + align:start position:0% +you could number them you know zero one +two + + align:start position:0% +two + + + align:start position:0% +two +three these are the levels + + align:start position:0% +three these are the levels + + + align:start position:0% +three these are the levels +and let's just like delete some of those + + align:start position:0% +and let's just like delete some of those + + + align:start position:0% +and let's just like delete some of those +layers let's say let's delete every + + align:start position:0% +layers let's say let's delete every + + + align:start position:0% +layers let's say let's delete every +fourth layer + + align:start position:0% +fourth layer + + + align:start position:0% +fourth layer +so maybe i delete this one i delete all + + align:start position:0% +so maybe i delete this one i delete all + + + align:start position:0% +so maybe i delete this one i delete all +the vertices in that layer + + align:start position:0% +the vertices in that layer + + + align:start position:0% +the vertices in that layer +and then i delete all the things in + + align:start position:0% +and then i delete all the things in + + + align:start position:0% +and then i delete all the things in +layer 8 and layer 12 + + align:start position:0% +layer 8 and layer 12 + + + align:start position:0% +layer 8 and layer 12 +and so on guessing + + align:start position:0% +and so on guessing + + + align:start position:0% +and so on guessing +i don't know which one to start with but + + align:start position:0% +i don't know which one to start with but + + + align:start position:0% +i don't know which one to start with but +from i'll just try them all + + align:start position:0% +from i'll just try them all + + + align:start position:0% +from i'll just try them all +and then i delete every fourth layer + + align:start position:0% +and then i delete every fourth layer + + + align:start position:0% +and then i delete every fourth layer +after that + + align:start position:0% +after that + + + align:start position:0% +after that +so i've deleted on average about a + + align:start position:0% +so i've deleted on average about a + + + align:start position:0% +so i've deleted on average about a +quarter of the graph + + align:start position:0% +quarter of the graph + + + align:start position:0% +quarter of the graph +and it turns out for a lot of problems + + align:start position:0% +and it turns out for a lot of problems + + + align:start position:0% +and it turns out for a lot of problems +that you care about + + align:start position:0% +that you care about + + + align:start position:0% +that you care about +like choosing where to place fire + + align:start position:0% +like choosing where to place fire + + + align:start position:0% +like choosing where to place fire +stations in this graph to minimize + + align:start position:0% +stations in this graph to minimize + + + align:start position:0% +stations in this graph to minimize +uh you know travel time for if there's a + + align:start position:0% +uh you know travel time for if there's a + + + align:start position:0% +uh you know travel time for if there's a +fire somewhere in the graph + + align:start position:0% +fire somewhere in the graph + + + align:start position:0% +fire somewhere in the graph +this happens you know fires and graphs + + align:start position:0% +this happens you know fires and graphs + + + align:start position:0% +this happens you know fires and graphs +then + + align:start position:0% +then + + + align:start position:0% +then +this will only hurt your solution by + + align:start position:0% +this will only hurt your solution by + + + align:start position:0% +this will only hurt your solution by +like a factor + + align:start position:0% +like a factor + + + align:start position:0% +like a factor +of uh one plus a quarter + + align:start position:0% +of uh one plus a quarter + + + align:start position:0% +of uh one plus a quarter +uh so you'll get a solution that's uh + + align:start position:0% +uh so you'll get a solution that's uh + + + align:start position:0% +uh so you'll get a solution that's uh +within + + align:start position:0% +within + + + align:start position:0% +within +25 of the optimal for a lot of problems + + align:start position:0% +25 of the optimal for a lot of problems + + + align:start position:0% +25 of the optimal for a lot of problems +um and uh + + align:start position:0% +um and uh + + + align:start position:0% +um and uh +that works for any value of four so i + + align:start position:0% +that works for any value of four so i + + + align:start position:0% +that works for any value of four so i +could do it for ten + + align:start position:0% +could do it for ten + + + align:start position:0% +could do it for ten +and then i'd get within ten percent of + + align:start position:0% +and then i'd get within ten percent of + + + align:start position:0% +and then i'd get within ten percent of +the optimal solution + + align:start position:0% +the optimal solution + + + align:start position:0% +the optimal solution +uh okay but how do i actually solve the + + align:start position:0% +uh okay but how do i actually solve the + + + align:start position:0% +uh okay but how do i actually solve the +problem once i delete every fourth + + align:start position:0% +problem once i delete every fourth + + + align:start position:0% +problem once i delete every fourth +layer well then your graph has this + + align:start position:0% +layer well then your graph has this + + + align:start position:0% +layer well then your graph has this +extra special structure + + align:start position:0% +extra special structure + + + align:start position:0% +extra special structure +which is a constant number of layers + + align:start position:0% +which is a constant number of layers + + + align:start position:0% +which is a constant number of layers +let's say a constant number of breadth + + align:start position:0% +let's say a constant number of breadth + + + align:start position:0% +let's say a constant number of breadth +first search layers if you just look at + + align:start position:0% +first search layers if you just look at + + + align:start position:0% +first search layers if you just look at +this portion this connected component + + align:start position:0% +this portion this connected component + + + align:start position:0% +this portion this connected component +or this connected component in here you + + align:start position:0% +or this connected component in here you + + + align:start position:0% +or this connected component in here you +can + + align:start position:0% +can + + + align:start position:0% +can +your graph is almost like a cycle + + align:start position:0% +your graph is almost like a cycle + + + align:start position:0% +your graph is almost like a cycle +it's like four cycles kind of stacked up + + align:start position:0% +it's like four cycles kind of stacked up + + + align:start position:0% +it's like four cycles kind of stacked up +together with some connections between + + align:start position:0% +together with some connections between + + + align:start position:0% +together with some connections between +them + + align:start position:0% +them + + + align:start position:0% +them +and it turns out that's something you + + align:start position:0% +and it turns out that's something you + + + align:start position:0% +and it turns out that's something you +can solve with very fancy dynamic + + align:start position:0% +can solve with very fancy dynamic + + + align:start position:0% +can solve with very fancy dynamic +programming + + align:start position:0% +programming + + + align:start position:0% +programming +like the stuff we've seen before in this + + align:start position:0% +like the stuff we've seen before in this + + + align:start position:0% +like the stuff we've seen before in this +class which focuses on just a single + + align:start position:0% +class which focuses on just a single + + + align:start position:0% +class which focuses on just a single +path or a single cycle + + align:start position:0% +path or a single cycle + + + align:start position:0% +path or a single cycle +if you just have a constant number of + + align:start position:0% +if you just have a constant number of + + + align:start position:0% +if you just have a constant number of +cycles with more work you can still do + + align:start position:0% +cycles with more work you can still do + + + align:start position:0% +cycles with more work you can still do +everything in polynomial time + + align:start position:0% +everything in polynomial time + + + align:start position:0% +everything in polynomial time +and so this is a very general approach + + align:start position:0% +and so this is a very general approach + + + align:start position:0% +and so this is a very general approach +for getting + + align:start position:0% +for getting + + + align:start position:0% +for getting +arbitrarily good approximation + + align:start position:0% +arbitrarily good approximation + + + align:start position:0% +arbitrarily good approximation +algorithms we call these one plus + + align:start position:0% +algorithms we call these one plus + + + align:start position:0% +algorithms we call these one plus +epsilon approximation for any epsilon + + align:start position:0% +epsilon approximation for any epsilon + + + align:start position:0% +epsilon approximation for any epsilon +but the larger the epsilon the more time + + align:start position:0% +but the larger the epsilon the more time + + + align:start position:0% +but the larger the epsilon the more time +you take it's something like + + align:start position:0% +you take it's something like + + + align:start position:0% +you take it's something like +two to the order one over epsilon times + + align:start position:0% +two to the order one over epsilon times + + + align:start position:0% +two to the order one over epsilon times +polynomial and n so as long as epsilon's + + align:start position:0% +polynomial and n so as long as epsilon's + + + align:start position:0% +polynomial and n so as long as epsilon's +constant this is polynomial time + + align:start position:0% +constant this is polynomial time + + + align:start position:0% +constant this is polynomial time +this is called a p-tess + + align:start position:0% + + + + align:start position:0% + +anyway those graph algorithms last topic + + align:start position:0% +anyway those graph algorithms last topic + + + align:start position:0% +anyway those graph algorithms last topic +is recreational algorithms which is + + align:start position:0% +is recreational algorithms which is + + + align:start position:0% +is recreational algorithms which is +maybe best encompassed by this class + + align:start position:0% +maybe best encompassed by this class + + + align:start position:0% +maybe best encompassed by this class +6892 is its latest name it changes names + + align:start position:0% +6892 is its latest name it changes names + + + align:start position:0% +6892 is its latest name it changes names +every once in a while + + align:start position:0% +every once in a while + + + align:start position:0% +every once in a while +and i mentioned it in the hardness + + align:start position:0% +and i mentioned it in the hardness + + + align:start position:0% +and i mentioned it in the hardness +complexity lecture because this class is + + align:start position:0% +complexity lecture because this class is + + + align:start position:0% +complexity lecture because this class is +all about + + align:start position:0% +all about + + + align:start position:0% +all about +hardness proofs analyzing fun games and + + align:start position:0% +hardness proofs analyzing fun games and + + + align:start position:0% +hardness proofs analyzing fun games and +puzzles we saw the tetris + + align:start position:0% +puzzles we saw the tetris + + + align:start position:0% +puzzles we saw the tetris +np hardness in that lecture but you can + + align:start position:0% +np hardness in that lecture but you can + + + align:start position:0% +np hardness in that lecture but you can +also prove + + align:start position:0% +also prove + + + align:start position:0% +also prove +super mario brothers is hard or portal + + align:start position:0% +super mario brothers is hard or portal + + + align:start position:0% +super mario brothers is hard or portal +is hard or mario kart is hard + + align:start position:0% +is hard or mario kart is hard + + + align:start position:0% +is hard or mario kart is hard +or the witness some modern video game is + + align:start position:0% +or the witness some modern video game is + + + align:start position:0% +or the witness some modern video game is +hard + + align:start position:0% +hard + + + align:start position:0% +hard +or one of our latest results is that + + align:start position:0% +or one of our latest results is that + + + align:start position:0% +or one of our latest results is that +recursed that game in the top right + + align:start position:0% +recursed that game in the top right + + + align:start position:0% +recursed that game in the top right +is undecidable there's no algorithm to + + align:start position:0% +is undecidable there's no algorithm to + + + align:start position:0% +is undecidable there's no algorithm to +play that game perfectly + + align:start position:0% +play that game perfectly + + + align:start position:0% +play that game perfectly +so and you can even download the level + + align:start position:0% +so and you can even download the level + + + align:start position:0% +so and you can even download the level +and an example of the level and play it + + align:start position:0% +and an example of the level and play it + + + align:start position:0% +and an example of the level and play it +if you + + align:start position:0% +if you + + + align:start position:0% +if you +if you dare um so + + align:start position:0% +if you dare um so + + + align:start position:0% +if you dare um so +uh that's a lot of we have a lot of fun + + align:start position:0% +uh that's a lot of we have a lot of fun + + + align:start position:0% +uh that's a lot of we have a lot of fun +in that world + + align:start position:0% +in that world + + + align:start position:0% +in that world +of hardness of different games and + + align:start position:0% +of hardness of different games and + + + align:start position:0% +of hardness of different games and +puzzles + + align:start position:0% +puzzles + + + align:start position:0% +puzzles +uh where do i want to go next uh + + align:start position:0% +uh where do i want to go next uh + + + align:start position:0% +uh where do i want to go next uh +okay next topic is balloon twisting + + align:start position:0% +okay next topic is balloon twisting + + + align:start position:0% +okay next topic is balloon twisting +totally different + + align:start position:0% +totally different + + + align:start position:0% +totally different +this is recreational but not about + + align:start position:0% +this is recreational but not about + + + align:start position:0% +this is recreational but not about +hardness so this is an octahedron + + align:start position:0% +hardness so this is an octahedron + + + align:start position:0% +hardness so this is an octahedron +twisted from one balloon i mean another + + align:start position:0% +twisted from one balloon i mean another + + + align:start position:0% +twisted from one balloon i mean another +one + + align:start position:0% +one + + + align:start position:0% +one +on a stick and so each of these is made + + align:start position:0% +on a stick and so each of these is made + + + align:start position:0% +on a stick and so each of these is made +from one balloon what graphs can you + + align:start position:0% +from one balloon what graphs can you + + + align:start position:0% +from one balloon what graphs can you +make + + align:start position:0% +make + + + align:start position:0% +make +for one balloon well you should read our + + align:start position:0% +for one balloon well you should read our + + + align:start position:0% +for one balloon well you should read our +paper + + align:start position:0% +paper + + + align:start position:0% +paper +and you can characterize how many + + align:start position:0% +and you can characterize how many + + + align:start position:0% +and you can characterize how many +balloons you need to make each + + align:start position:0% +balloons you need to make each + + + align:start position:0% +balloons you need to make each +each polyhedron and some of these + + align:start position:0% +each polyhedron and some of these + + + align:start position:0% +each polyhedron and some of these +problems are np hard + + align:start position:0% +problems are np hard + + + align:start position:0% +problems are np hard +and it's a lot of fun + + align:start position:0% +and it's a lot of fun + + + align:start position:0% +and it's a lot of fun +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +cool i think that's the end of the + + align:start position:0% +cool i think that's the end of the + + + align:start position:0% +cool i think that's the end of the +slides uh the last thing i wanted to + + align:start position:0% +slides uh the last thing i wanted to + + + align:start position:0% +slides uh the last thing i wanted to +show you + + align:start position:0% +show you + + + align:start position:0% +show you +is a + + align:start position:0% +is a + + + align:start position:0% +is a +problem a puzzle slash magic trick comes + + align:start position:0% +problem a puzzle slash magic trick comes + + + align:start position:0% +problem a puzzle slash magic trick comes +from the puzzle world + + align:start position:0% +from the puzzle world + + + align:start position:0% +from the puzzle world +called the picture hanging problem so + + align:start position:0% +called the picture hanging problem so + + + align:start position:0% +called the picture hanging problem so +imagine you have a picture + + align:start position:0% +imagine you have a picture + + + align:start position:0% +imagine you have a picture +you want to hang it on a wall so you + + align:start position:0% +you want to hang it on a wall so you + + + align:start position:0% +you want to hang it on a wall so you +invested in some nice rope + + align:start position:0% +invested in some nice rope + + + align:start position:0% +invested in some nice rope +and you hang it and then if the on a + + align:start position:0% +and you hang it and then if the on a + + + align:start position:0% +and you hang it and then if the on a +nail + + align:start position:0% +nail + + + align:start position:0% +nail +if the nail falls out the picture falls + + align:start position:0% +if the nail falls out the picture falls + + + align:start position:0% +if the nail falls out the picture falls +and you're set + + align:start position:0% +and you're set + + + align:start position:0% +and you're set +so you invest in two nails like i have + + align:start position:0% +so you invest in two nails like i have + + + align:start position:0% +so you invest in two nails like i have +here + + align:start position:0% +here + + + align:start position:0% +here +and maybe you hang your picture on both + + align:start position:0% +and maybe you hang your picture on both + + + align:start position:0% +and maybe you hang your picture on both +those nails now if one of the nails + + align:start position:0% +those nails now if one of the nails + + + align:start position:0% +those nails now if one of the nails +falls out you still have a crookedly + + align:start position:0% +falls out you still have a crookedly + + + align:start position:0% +falls out you still have a crookedly +hung picture + + align:start position:0% +hung picture + + + align:start position:0% +hung picture +the other nail falls out okay it's gone + + align:start position:0% +the other nail falls out okay it's gone + + + align:start position:0% +the other nail falls out okay it's gone +i want to hang a picture on two nails + + align:start position:0% +i want to hang a picture on two nails + + + align:start position:0% +i want to hang a picture on two nails +such that if i remove either nail the + + align:start position:0% +such that if i remove either nail the + + + align:start position:0% +such that if i remove either nail the +picture falls so jason pick a nail left + + align:start position:0% +picture falls so jason pick a nail left + + + align:start position:0% +picture falls so jason pick a nail left +or right + + align:start position:0% +or right + + + align:start position:0% +or right +left we remove make sure this doesn't + + align:start position:0% +left we remove make sure this doesn't + + + align:start position:0% +left we remove make sure this doesn't +fall off + + align:start position:0% +fall off + + + align:start position:0% +fall off +and boom the picture falls same wrapping + + align:start position:0% +and boom the picture falls same wrapping + + + align:start position:0% +and boom the picture falls same wrapping +you can check you can rewind the video + + align:start position:0% +you can check you can rewind the video + + + align:start position:0% +you can check you can rewind the video +make sure i did the same wrapping + + align:start position:0% +make sure i did the same wrapping + + + align:start position:0% +make sure i did the same wrapping +okay take out the right one good choice + + align:start position:0% +okay take out the right one good choice + + + align:start position:0% +okay take out the right one good choice +uh + + align:start position:0% +uh + + + align:start position:0% +uh +then also the picture false + + align:start position:0% +then also the picture false + + + align:start position:0% +then also the picture false +uh and so this is a classic puzzle but + + align:start position:0% +uh and so this is a classic puzzle but + + + align:start position:0% +uh and so this is a classic puzzle but +you can generalize it so let me do it to + + align:start position:0% +you can generalize it so let me do it to + + + align:start position:0% +you can generalize it so let me do it to +for three nails which is all i have here + + align:start position:0% +for three nails which is all i have here + + + align:start position:0% +for three nails which is all i have here +this nail sagging a little bit uh y + + align:start position:0% +this nail sagging a little bit uh y + + + align:start position:0% +this nail sagging a little bit uh y +x and y inverse x inverse okay i think + + align:start position:0% +x and y inverse x inverse okay i think + + + align:start position:0% +x and y inverse x inverse okay i think +that's right + + align:start position:0% +that's right + + + align:start position:0% +that's right +uh so this is one way to hang a picture + + align:start position:0% +uh so this is one way to hang a picture + + + align:start position:0% +uh so this is one way to hang a picture +on three nails such as if i remove any + + align:start position:0% +on three nails such as if i remove any + + + align:start position:0% +on three nails such as if i remove any +of the nails + + align:start position:0% +of the nails + + + align:start position:0% +of the nails +picture falls uh just justin uh one two + + align:start position:0% +picture falls uh just justin uh one two + + + align:start position:0% +picture falls uh just justin uh one two +or three + + align:start position:0% +or three + + + align:start position:0% +or three +two two okay + + align:start position:0% +two two okay + + + align:start position:0% +two two okay +yeah i wanna get out of the way make + + align:start position:0% +yeah i wanna get out of the way make + + + align:start position:0% +yeah i wanna get out of the way make +sure make sure i don't go + + align:start position:0% +sure make sure i don't go + + + align:start position:0% +sure make sure i don't go +over the edge here + + align:start position:0% + + + + align:start position:0% + +yeah it's a lot easier to make this one + + align:start position:0% +yeah it's a lot easier to make this one + + + align:start position:0% +yeah it's a lot easier to make this one +work + + align:start position:0% +work + + + align:start position:0% +work +but you can see boom picture falls there + + align:start position:0% +but you can see boom picture falls there + + + align:start position:0% +but you can see boom picture falls there +and of course + + align:start position:0% +and of course + + + align:start position:0% +and of course +imagine infinite gravity and the picture + + align:start position:0% +imagine infinite gravity and the picture + + + align:start position:0% +imagine infinite gravity and the picture +falls tada + + align:start position:0% +falls tada + + + align:start position:0% +falls tada +and so you can generalize this to do + + align:start position:0% +and so you can generalize this to do + + + align:start position:0% +and so you can generalize this to do +essentially any + + align:start position:0% +essentially any + + + align:start position:0% +essentially any +it's called a monotone boolean function + + align:start position:0% +it's called a monotone boolean function + + + align:start position:0% +it's called a monotone boolean function +on any set of nails + + align:start position:0% +on any set of nails + + + align:start position:0% +on any set of nails +i mean you can make any subset of the + + align:start position:0% +i mean you can make any subset of the + + + align:start position:0% +i mean you can make any subset of the +nails cause the picture to fall + + align:start position:0% +nails cause the picture to fall + + + align:start position:0% +nails cause the picture to fall +and any collection of subsets of nails + + align:start position:0% +and any collection of subsets of nails + + + align:start position:0% +and any collection of subsets of nails +to make it fall of course if you remove + + align:start position:0% +to make it fall of course if you remove + + + align:start position:0% +to make it fall of course if you remove +more nails it's still going to fall + + align:start position:0% +more nails it's still going to fall + + + align:start position:0% +more nails it's still going to fall +that's the monotone sense but otherwise + + align:start position:0% +that's the monotone sense but otherwise + + + align:start position:0% +that's the monotone sense but otherwise +you can do an arbitrary + + align:start position:0% +you can do an arbitrary + + + align:start position:0% +you can do an arbitrary +pattern which is fun that's actually + + align:start position:0% +pattern which is fun that's actually + + + align:start position:0% +pattern which is fun that's actually +result with ron rivest and a bunch of + + align:start position:0% +result with ron rivest and a bunch of + + + align:start position:0% +result with ron rivest and a bunch of +other + + align:start position:0% +other + + + align:start position:0% +other +other people um i think + + align:start position:0% +other people um i think + + + align:start position:0% +other people um i think +i'm approximately on time so that was a + + align:start position:0% +i'm approximately on time so that was a + + + align:start position:0% +i'm approximately on time so that was a +quick tour + + align:start position:0% +quick tour + + + align:start position:0% +quick tour +and there are obviously various classes + + align:start position:0% +and there are obviously various classes + + + align:start position:0% +and there are obviously various classes +here you can take + + align:start position:0% +here you can take + + + align:start position:0% +here you can take +6892 the hardness class was just offered + + align:start position:0% +6892 the hardness class was just offered + + + align:start position:0% +6892 the hardness class was just offered +last semester so probably won't be for a + + align:start position:0% +last semester so probably won't be for a + + + align:start position:0% +last semester so probably won't be for a +while + + align:start position:0% +while + + + align:start position:0% +while +all these classes are online watch the + + align:start position:0% +all these classes are online watch the + + + align:start position:0% +all these classes are online watch the +videos feel free to ask me questions + + align:start position:0% +videos feel free to ask me questions + + + align:start position:0% +videos feel free to ask me questions +and now we have justin i left you space + + align:start position:0% +and now we have justin i left you space + + + align:start position:0% +and now we have justin i left you space +here + + align:start position:0% +here + + + align:start position:0% +here +for your outline + + align:start position:0% + + + + align:start position:0% + +you don't have to + + align:start position:0% +you don't have to + + + align:start position:0% +you don't have to +but i'll put your name out thank you + + align:start position:0% + + + + align:start position:0% + +so jess justin is also a jabiter yeah + + align:start position:0% +so jess justin is also a jabiter yeah + + + align:start position:0% +so jess justin is also a jabiter yeah +we've got a lot of geometry people in + + align:start position:0% +we've got a lot of geometry people in + + + align:start position:0% +we've got a lot of geometry people in +double six this semester thank you + + align:start position:0% +double six this semester thank you + + + align:start position:0% +double six this semester thank you +okay you know it's like i can't help but + + align:start position:0% +okay you know it's like i can't help but + + + align:start position:0% +okay you know it's like i can't help but +share that on our + + align:start position:0% +share that on our + + + align:start position:0% +share that on our +instructor chat eric was texting that he + + align:start position:0% +instructor chat eric was texting that he + + + align:start position:0% +instructor chat eric was texting that he +was going to be + + align:start position:0% +was going to be + + + align:start position:0% +was going to be +he was somehow nervous that the applied + + align:start position:0% +he was somehow nervous that the applied + + + align:start position:0% +he was somehow nervous that the applied +guy would have all the like the cool + + align:start position:0% +guy would have all the like the cool + + + align:start position:0% +guy would have all the like the cool +stuff to show off + + align:start position:0% +stuff to show off + + + align:start position:0% +stuff to show off +and now i feel totally boring uh + + align:start position:0% +and now i feel totally boring uh + + + align:start position:0% +and now i feel totally boring uh +right yeah so yeah we have three + + align:start position:0% +right yeah so yeah we have three + + + align:start position:0% +right yeah so yeah we have three +different geometry instructors uh + + align:start position:0% +different geometry instructors uh + + + align:start position:0% +different geometry instructors uh +in in this class we have many different + + align:start position:0% +in in this class we have many different + + + align:start position:0% +in in this class we have many different +flavors of geometry that are kind of + + align:start position:0% +flavors of geometry that are kind of + + + align:start position:0% +flavors of geometry that are kind of +represented in this this room here from + + align:start position:0% +represented in this this room here from + + + align:start position:0% +represented in this this room here from +mechanical engineering to + + align:start position:0% +mechanical engineering to + + + align:start position:0% +mechanical engineering to +theory plus lots of other cool stuff to + + align:start position:0% +theory plus lots of other cool stuff to + + + align:start position:0% +theory plus lots of other cool stuff to +uh whatever it is that i do + + align:start position:0% +uh whatever it is that i do + + + align:start position:0% +uh whatever it is that i do +um all right so i'm a professor also + + align:start position:0% +um all right so i'm a professor also + + + align:start position:0% +um all right so i'm a professor also +from brazil and lead a group that + + align:start position:0% +from brazil and lead a group that + + + align:start position:0% +from brazil and lead a group that +studies + + align:start position:0% +studies + + + align:start position:0% +studies +slightly more applied geometry problems + + align:start position:0% +slightly more applied geometry problems + + + align:start position:0% +slightly more applied geometry problems +in some sense + + align:start position:0% +in some sense + + + align:start position:0% +in some sense +in seasonal we kind of cross a lot of + + align:start position:0% +in seasonal we kind of cross a lot of + + + align:start position:0% +in seasonal we kind of cross a lot of +boundaries actually closer to the math + + align:start position:0% +boundaries actually closer to the math + + + align:start position:0% +boundaries actually closer to the math +department than to the theory group in + + align:start position:0% +department than to the theory group in + + + align:start position:0% +department than to the theory group in +computer science + + align:start position:0% +computer science + + + align:start position:0% +computer science +which i would argue is largely a + + align:start position:0% +which i would argue is largely a + + + align:start position:0% +which i would argue is largely a +historical artifact rather than anything + + align:start position:0% +historical artifact rather than anything + + + align:start position:0% +historical artifact rather than anything +interesting about computer science or + + align:start position:0% +interesting about computer science or + + + align:start position:0% +interesting about computer science or +math um + + align:start position:0% +math um + + + align:start position:0% +math um +so continuing in our whirlwind tour of + + align:start position:0% +so continuing in our whirlwind tour of + + + align:start position:0% +so continuing in our whirlwind tour of +interesting geometry classes here at mit + + align:start position:0% +interesting geometry classes here at mit + + + align:start position:0% +interesting geometry classes here at mit +uh i have some more fun things to to add + + align:start position:0% +uh i have some more fun things to to add + + + align:start position:0% +uh i have some more fun things to to add +to the list and we'll introduce some of + + align:start position:0% +to the list and we'll introduce some of + + + align:start position:0% +to the list and we'll introduce some of +the ideas in the next couple slides here + + align:start position:0% +the ideas in the next couple slides here + + + align:start position:0% +the ideas in the next couple slides here +uh so uh normally every fall i teach + + align:start position:0% +uh so uh normally every fall i teach + + + align:start position:0% +uh so uh normally every fall i teach + + align:start position:0% + + + align:start position:0% +uh which is the introduction to computer + + align:start position:0% +uh which is the introduction to computer + + + align:start position:0% +uh which is the introduction to computer +graphics course in fact my + + align:start position:0% +graphics course in fact my + + + align:start position:0% +graphics course in fact my +background was was working in an + + align:start position:0% +background was was working in an + + + align:start position:0% +background was was working in an +animation studio for a little bit of + + align:start position:0% +animation studio for a little bit of + + + align:start position:0% +animation studio for a little bit of +time and and + + align:start position:0% +time and and + + + align:start position:0% +time and and +uh got one movie credit out of it until + + align:start position:0% +uh got one movie credit out of it until + + + align:start position:0% +uh got one movie credit out of it until +they changed the standards for movie + + align:start position:0% +they changed the standards for movie + + + align:start position:0% +they changed the standards for movie +credits and then that stopped happening + + align:start position:0% +credits and then that stopped happening + + + align:start position:0% +credits and then that stopped happening +uh but but in any event uh if you watch + + align:start position:0% +uh but but in any event uh if you watch + + + align:start position:0% +uh but but in any event uh if you watch +what's that movie up with the old man + + align:start position:0% +what's that movie up with the old man + + + align:start position:0% +what's that movie up with the old man +if you hit pause at just the right + + align:start position:0% +if you hit pause at just the right + + + align:start position:0% +if you hit pause at just the right +moment you can find me right above the + + align:start position:0% +moment you can find me right above the + + + align:start position:0% +moment you can find me right above the +list of babies that were born during + + align:start position:0% +list of babies that were born during + + + align:start position:0% +list of babies that were born during +uh production uh but in any event um + + align:start position:0% +uh production uh but in any event um + + + align:start position:0% +uh production uh but in any event um +although computer graphics might not + + align:start position:0% +although computer graphics might not + + + align:start position:0% +although computer graphics might not +sound like an algorithmic discipline + + align:start position:0% +sound like an algorithmic discipline + + + align:start position:0% +sound like an algorithmic discipline +i'll try to convince you guys that + + align:start position:0% +i'll try to convince you guys that + + + align:start position:0% +i'll try to convince you guys that +in some sense you can take just about + + align:start position:0% +in some sense you can take just about + + + align:start position:0% +in some sense you can take just about +anybody in our department have them + + align:start position:0% +anybody in our department have them + + + align:start position:0% +anybody in our department have them +teach 606 and give a similar talk that + + align:start position:0% +teach 606 and give a similar talk that + + + align:start position:0% +teach 606 and give a similar talk that +like + + align:start position:0% +like + + + align:start position:0% +like +the material that you've encountered in + + align:start position:0% +the material that you've encountered in + + + align:start position:0% +the material that you've encountered in +this course is going to be relevant to + + align:start position:0% +this course is going to be relevant to + + + align:start position:0% +this course is going to be relevant to +your life + + align:start position:0% +your life + + + align:start position:0% +your life +uh the other course that i teach that + + align:start position:0% +uh the other course that i teach that + + + align:start position:0% +uh the other course that i teach that +might be of interest uh + + align:start position:0% +might be of interest uh + + + align:start position:0% +might be of interest uh +and actually is a little more + + align:start position:0% +and actually is a little more + + + align:start position:0% +and actually is a little more +theoretically flavored uh that i teach + + align:start position:0% +theoretically flavored uh that i teach + + + align:start position:0% +theoretically flavored uh that i teach +is a six eight three eight + + align:start position:0% +is a six eight three eight + + + align:start position:0% +is a six eight three eight +so since eric so kindly put my board my + + align:start position:0% +so since eric so kindly put my board my + + + align:start position:0% +so since eric so kindly put my board my +name on the board here i guess i can + + align:start position:0% +name on the board here i guess i can + + + align:start position:0% +name on the board here i guess i can +draw a picture + + align:start position:0% +draw a picture + + + align:start position:0% +draw a picture +so the main object of interest in six + + align:start position:0% +so the main object of interest in six + + + align:start position:0% +so the main object of interest in six +eight three eight + + align:start position:0% +eight three eight + + + align:start position:0% +eight three eight +is a particular thing called a + + align:start position:0% +is a particular thing called a + + + align:start position:0% +is a particular thing called a +simplicial complex + + align:start position:0% + + + + align:start position:0% + +so um usually uh in 606 we spend a lot + + align:start position:0% +so um usually uh in 606 we spend a lot + + + align:start position:0% +so um usually uh in 606 we spend a lot +of time thinking about graphs + + align:start position:0% +of time thinking about graphs + + + align:start position:0% +of time thinking about graphs +so let me draw you a graph so i'm going + + align:start position:0% +so let me draw you a graph so i'm going + + + align:start position:0% +so let me draw you a graph so i'm going +to take a square + + align:start position:0% +to take a square + + + align:start position:0% +to take a square +and subdivide it and now let's say i put + + align:start position:0% +and subdivide it and now let's say i put + + + align:start position:0% +and subdivide it and now let's say i put +edges diagonally + + align:start position:0% +edges diagonally + + + align:start position:0% +edges diagonally +like that now + + align:start position:0% +like that now + + + align:start position:0% +like that now +and pick from the most important thing + + align:start position:0% +and pick from the most important thing + + + align:start position:0% +and pick from the most important thing +is a bunch of notes can + + align:start position:0% +is a bunch of notes can + + + align:start position:0% +is a bunch of notes can +connect my edges in fact if i took this + + align:start position:0% +connect my edges in fact if i took this + + + align:start position:0% +connect my edges in fact if i took this +edge and i like moved it down or + + align:start position:0% +edge and i like moved it down or + + + align:start position:0% +edge and i like moved it down or +something it would be the same graph + + align:start position:0% +something it would be the same graph + + + align:start position:0% +something it would be the same graph +uh but of course in a lot of uh computer + + align:start position:0% +uh but of course in a lot of uh computer + + + align:start position:0% +uh but of course in a lot of uh computer +graphics applications this thing also + + align:start position:0% +graphics applications this thing also + + + align:start position:0% +graphics applications this thing also +looks an awful lot like a square uh and + + align:start position:0% +looks an awful lot like a square uh and + + + align:start position:0% +looks an awful lot like a square uh and +the reason + + align:start position:0% +the reason + + + align:start position:0% +the reason +is that of course the graph here + + align:start position:0% +is that of course the graph here + + + align:start position:0% +is that of course the graph here +contains triangles inside of it + + align:start position:0% +contains triangles inside of it + + + align:start position:0% +contains triangles inside of it +uh and so for instance um maybe + + align:start position:0% +uh and so for instance um maybe + + + align:start position:0% +uh and so for instance um maybe +i think of my graph as a collection of + + align:start position:0% +i think of my graph as a collection of + + + align:start position:0% +i think of my graph as a collection of +vertices clutching edges this is the + + align:start position:0% +vertices clutching edges this is the + + + align:start position:0% +vertices clutching edges this is the +sort of notation we've seen before + + align:start position:0% +sort of notation we've seen before + + + align:start position:0% +sort of notation we've seen before +and then i add a third thing to my trip + + align:start position:0% +and then i add a third thing to my trip + + + align:start position:0% +and then i add a third thing to my trip +uh to my + + align:start position:0% +uh to my + + + align:start position:0% +uh to my +description which is a set of triplets + + align:start position:0% +description which is a set of triplets + + + align:start position:0% +description which is a set of triplets +uh that's a set of triangles here + + align:start position:0% +uh that's a set of triangles here + + + align:start position:0% +uh that's a set of triangles here +right and we can take a lot of the + + align:start position:0% +right and we can take a lot of the + + + align:start position:0% +right and we can take a lot of the +algorithms that we've talked about in + + align:start position:0% +algorithms that we've talked about in + + + align:start position:0% +algorithms that we've talked about in +this class and extend it to this case so + + align:start position:0% +this class and extend it to this case so + + + align:start position:0% +this class and extend it to this case so +for example + + align:start position:0% +for example + + + align:start position:0% +for example +um here's a deceptively annoying one uh + + align:start position:0% +um here's a deceptively annoying one uh + + + align:start position:0% +um here's a deceptively annoying one uh +let's say that i want the shortest path + + align:start position:0% +let's say that i want the shortest path + + + align:start position:0% +let's say that i want the shortest path +between two vertices on my graph + + align:start position:0% +between two vertices on my graph + + + align:start position:0% +between two vertices on my graph +yeah so we certainly have learned + + align:start position:0% +yeah so we certainly have learned + + + align:start position:0% +yeah so we certainly have learned +dijkstra's algorithm as one technique to + + align:start position:0% +dijkstra's algorithm as one technique to + + + align:start position:0% +dijkstra's algorithm as one technique to +do that + + align:start position:0% +do that + + + align:start position:0% +do that +and indeed common practice in computer + + align:start position:0% +and indeed common practice in computer + + + align:start position:0% +and indeed common practice in computer +graphics which is shameful + + align:start position:0% +graphics which is shameful + + + align:start position:0% +graphics which is shameful +uh is on your triangle mesh if you want + + align:start position:0% +uh is on your triangle mesh if you want + + + align:start position:0% +uh is on your triangle mesh if you want +the shortest path between two vertices + + align:start position:0% +the shortest path between two vertices + + + align:start position:0% +the shortest path between two vertices +run dijkstra's algorithm on the edges + + align:start position:0% +run dijkstra's algorithm on the edges + + + align:start position:0% +run dijkstra's algorithm on the edges +and let's see if that works really quick + + align:start position:0% +and let's see if that works really quick + + + align:start position:0% +and let's see if that works really quick +so let's say that i want the shortest + + align:start position:0% +so let's say that i want the shortest + + + align:start position:0% +so let's say that i want the shortest +path between + + align:start position:0% +path between + + + align:start position:0% +path between +and by the way i'm going to assume the + + align:start position:0% +and by the way i'm going to assume the + + + align:start position:0% +and by the way i'm going to assume the +lengths of my edges are like the lengths + + align:start position:0% +lengths of my edges are like the lengths + + + align:start position:0% +lengths of my edges are like the lengths +as i've drawn them on the board here so + + align:start position:0% +as i've drawn them on the board here so + + + align:start position:0% +as i've drawn them on the board here so +it's like 1 + + align:start position:0% +it's like 1 + + + align:start position:0% +it's like 1 +1 square root of 2. okay so let's say i + + align:start position:0% +1 square root of 2. okay so let's say i + + + align:start position:0% +1 square root of 2. okay so let's say i +want the shortest path between the + + align:start position:0% +want the shortest path between the + + + align:start position:0% +want the shortest path between the +bottom left and the upper right + + align:start position:0% +bottom left and the upper right + + + align:start position:0% +bottom left and the upper right +for run dijkstra's algorithm we're in + + align:start position:0% +for run dijkstra's algorithm we're in + + + align:start position:0% +for run dijkstra's algorithm we're in +good shape right we could uh you can + + align:start position:0% +good shape right we could uh you can + + + align:start position:0% +good shape right we could uh you can +i'll let you do the computations at home + + align:start position:0% +i'll let you do the computations at home + + + align:start position:0% +i'll let you do the computations at home +you'll get the path + + align:start position:0% +you'll get the path + + + align:start position:0% +you'll get the path +that is these two edges but here's a + + align:start position:0% +that is these two edges but here's a + + + align:start position:0% +that is these two edges but here's a +really annoying thing + + align:start position:0% +really annoying thing + + + align:start position:0% +really annoying thing +let's say instead i wanted the shortest + + align:start position:0% +let's say instead i wanted the shortest + + + align:start position:0% +let's say instead i wanted the shortest +path from the upper + + align:start position:0% +path from the upper + + + align:start position:0% +path from the upper +left to the lower right if i run + + align:start position:0% +left to the lower right if i run + + + align:start position:0% +left to the lower right if i run +dijkstra's algorithm on this + + align:start position:0% +dijkstra's algorithm on this + + + align:start position:0% +dijkstra's algorithm on this +triangulated square + + align:start position:0% +triangulated square + + + align:start position:0% +triangulated square +what's going to be the shortest path + + align:start position:0% +what's going to be the shortest path + + + align:start position:0% +what's going to be the shortest path +yeah in fact there's a bunch of them + + align:start position:0% +yeah in fact there's a bunch of them + + + align:start position:0% +yeah in fact there's a bunch of them +one of them might go all the way down + + align:start position:0% +one of them might go all the way down + + + align:start position:0% +one of them might go all the way down +and then all the way to the right + + align:start position:0% +and then all the way to the right + + + align:start position:0% +and then all the way to the right +what's the length of this path one two + + align:start position:0% +what's the length of this path one two + + + align:start position:0% +what's the length of this path one two +three four + + align:start position:0% +three four + + + align:start position:0% +three four +is that the length of the shortest path + + align:start position:0% +is that the length of the shortest path + + + align:start position:0% +is that the length of the shortest path +well probably not well we'd like our + + align:start position:0% +well probably not well we'd like our + + + align:start position:0% +well probably not well we'd like our +shortest path + + align:start position:0% +shortest path + + + align:start position:0% +shortest path +to do something like that but graphs + + align:start position:0% +to do something like that but graphs + + + align:start position:0% +to do something like that but graphs +don't know how to talk to + + align:start position:0% +don't know how to talk to + + + align:start position:0% +don't know how to talk to +triangles and this is going to be a + + align:start position:0% +triangles and this is going to be a + + + align:start position:0% +triangles and this is going to be a +problem + + align:start position:0% +problem + + + align:start position:0% +problem +in fact it wasn't until + + align:start position:0% +in fact it wasn't until + + + align:start position:0% +in fact it wasn't until +history terms that we were able to kind + + align:start position:0% +history terms that we were able to kind + + + align:start position:0% +history terms that we were able to kind +of work out the correct + + align:start position:0% +of work out the correct + + + align:start position:0% +of work out the correct +algorithm for a shortness of a + + align:start position:0% +algorithm for a shortness of a + + + align:start position:0% +algorithm for a shortness of a +triangulated domain like this um + + align:start position:0% +triangulated domain like this um + + + align:start position:0% +triangulated domain like this um +that's the runtime that we would expect + + align:start position:0% +that's the runtime that we would expect + + + align:start position:0% +that's the runtime that we would expect +this is called uh mnp + + align:start position:0% +this is called uh mnp + + + align:start position:0% +this is called uh mnp +i'm guessing eric and jason could do a + + align:start position:0% +i'm guessing eric and jason could do a + + + align:start position:0% +i'm guessing eric and jason could do a +better job describing it than i can + + align:start position:0% +better job describing it than i can + + + align:start position:0% +better job describing it than i can +but the basic idea of the mmp algorithm + + align:start position:0% +but the basic idea of the mmp algorithm + + + align:start position:0% +but the basic idea of the mmp algorithm +actually is a really + + align:start position:0% +actually is a really + + + align:start position:0% +actually is a really +happens to be a nice extension of the + + align:start position:0% +happens to be a nice extension of the + + + align:start position:0% +happens to be a nice extension of the +way that we taught uh dijkstra's + + align:start position:0% +way that we taught uh dijkstra's + + + align:start position:0% +way that we taught uh dijkstra's +algorithm in 6.06 because they really do + + align:start position:0% +algorithm in 6.06 because they really do + + + align:start position:0% +algorithm in 6.06 because they really do +keep track of these sort of level sets + + align:start position:0% +keep track of these sort of level sets + + + align:start position:0% +keep track of these sort of level sets +of the distance function + + align:start position:0% +of the distance function + + + align:start position:0% +of the distance function +but now the level sets have to like oops + + align:start position:0% +but now the level sets have to like oops + + + align:start position:0% +but now the level sets have to like oops +i have to window an + + align:start position:0% +i have to window an + + + align:start position:0% +i have to window an +edge like that when i uh compute short + + align:start position:0% +edge like that when i uh compute short + + + align:start position:0% +edge like that when i uh compute short +its path which is a giant headache + + align:start position:0% +its path which is a giant headache + + + align:start position:0% +its path which is a giant headache +this is one of these algorithms that was + + align:start position:0% +this is one of these algorithms that was + + + align:start position:0% +this is one of these algorithms that was +known in theory about 10 years before + + align:start position:0% +known in theory about 10 years before + + + align:start position:0% +known in theory about 10 years before +anybody bothered to implement it in a + + align:start position:0% +anybody bothered to implement it in a + + + align:start position:0% +anybody bothered to implement it in a +way that they could convince + + align:start position:0% +way that they could convince + + + align:start position:0% +way that they could convince +them themselves really random n log n + + align:start position:0% +them themselves really random n log n + + + align:start position:0% +them themselves really random n log n +time uh and nowadays is a cottage + + align:start position:0% +time uh and nowadays is a cottage + + + align:start position:0% +time uh and nowadays is a cottage +industry in + + align:start position:0% +industry in + + + align:start position:0% +industry in +in computer graphics research papers to + + align:start position:0% +in computer graphics research papers to + + + align:start position:0% +in computer graphics research papers to +implement this and then speed it up in + + align:start position:0% +implement this and then speed it up in + + + align:start position:0% +implement this and then speed it up in +different ways and + + align:start position:0% +different ways and + + + align:start position:0% +different ways and +sadly the reality is that a different + + align:start position:0% +sadly the reality is that a different + + + align:start position:0% +sadly the reality is that a different +number we cover in 6838 called fast + + align:start position:0% +number we cover in 6838 called fast + + + align:start position:0% +number we cover in 6838 called fast +marching which doesn't actually give you + + align:start position:0% +marching which doesn't actually give you + + + align:start position:0% +marching which doesn't actually give you +the shortest path but some approximation + + align:start position:0% +the shortest path but some approximation + + + align:start position:0% +the shortest path but some approximation +thereof + + align:start position:0% +thereof + + + align:start position:0% +thereof +uh is faster easier to use and basically + + align:start position:0% +uh is faster easier to use and basically + + + align:start position:0% +uh is faster easier to use and basically +indistinguishable um so in any event um + + align:start position:0% +indistinguishable um so in any event um + + + align:start position:0% +indistinguishable um so in any event um +in 683 we kind of have an interesting + + align:start position:0% +in 683 we kind of have an interesting + + + align:start position:0% +in 683 we kind of have an interesting +we'll talk about a lot of algorithms + + align:start position:0% +we'll talk about a lot of algorithms + + + align:start position:0% +we'll talk about a lot of algorithms +that look like what we've done + + align:start position:0% +that look like what we've done + + + align:start position:0% +that look like what we've done +in whatever this class it's uh 6.006 + + align:start position:0% +in whatever this class it's uh 6.006 + + + align:start position:0% +in whatever this class it's uh 6.006 +um but at the same time start to have a + + align:start position:0% +um but at the same time start to have a + + + align:start position:0% +um but at the same time start to have a +more geometric flavor and we + + align:start position:0% +more geometric flavor and we + + + align:start position:0% +more geometric flavor and we +don't worry quite as much about uh so in + + align:start position:0% +don't worry quite as much about uh so in + + + align:start position:0% +don't worry quite as much about uh so in +our computation model oftentimes we're + + align:start position:0% +our computation model oftentimes we're + + + align:start position:0% +our computation model oftentimes we're +kind of okay with real numbers because + + align:start position:0% +kind of okay with real numbers because + + + align:start position:0% +kind of okay with real numbers because +that's not where + + align:start position:0% +that's not where + + + align:start position:0% +that's not where +the headache is and of course when you + + align:start position:0% +the headache is and of course when you + + + align:start position:0% +the headache is and of course when you +write your code in this class you use + + align:start position:0% +write your code in this class you use + + + align:start position:0% +write your code in this class you use +double precision floating point + + align:start position:0% +double precision floating point + + + align:start position:0% +double precision floating point +if you're more responsible like in in + + align:start position:0% +if you're more responsible like in in + + + align:start position:0% +if you're more responsible like in in +jason's previous lecture you should + + align:start position:0% +jason's previous lecture you should + + + align:start position:0% +jason's previous lecture you should +probably keep track of + + align:start position:0% +probably keep track of + + + align:start position:0% +probably keep track of +the number of operations to make sure + + align:start position:0% +the number of operations to make sure + + + align:start position:0% +the number of operations to make sure +that your error is bounded but no i'm + + align:start position:0% +that your error is bounded but no i'm + + + align:start position:0% +that your error is bounded but no i'm +not sure that we + + align:start position:0% +not sure that we + + + align:start position:0% +not sure that we +really bother with that um in any event + + align:start position:0% +really bother with that um in any event + + + align:start position:0% +really bother with that um in any event +this allows us to kind of have two + + align:start position:0% +this allows us to kind of have two + + + align:start position:0% +this allows us to kind of have two +different mindsets right there's one + + align:start position:0% +different mindsets right there's one + + + align:start position:0% +different mindsets right there's one +mindset which is discreet + + align:start position:0% +mindset which is discreet + + + align:start position:0% +mindset which is discreet +there's another mindset which is smooth + + align:start position:0% +there's another mindset which is smooth + + + align:start position:0% +there's another mindset which is smooth +right so we think about + + align:start position:0% +right so we think about + + + align:start position:0% +right so we think about +understanding geometry like these + + align:start position:0% +understanding geometry like these + + + align:start position:0% +understanding geometry like these +triangulated domains as an approximation + + align:start position:0% +triangulated domains as an approximation + + + align:start position:0% +triangulated domains as an approximation +of a smooth surface + + align:start position:0% +of a smooth surface + + + align:start position:0% +of a smooth surface +and then we might want to do stuff like + + align:start position:0% +and then we might want to do stuff like + + + align:start position:0% +and then we might want to do stuff like +compute curvature and so on which is + + align:start position:0% +compute curvature and so on which is + + + align:start position:0% +compute curvature and so on which is +really associated with computing + + align:start position:0% +really associated with computing + + + align:start position:0% +really associated with computing +derivatives + + align:start position:0% +derivatives + + + align:start position:0% +derivatives +which of course we don't have on these + + align:start position:0% +which of course we don't have on these + + + align:start position:0% +which of course we don't have on these +kinds of special objects + + align:start position:0% +kinds of special objects + + + align:start position:0% +kinds of special objects +and that leads to this really fun area + + align:start position:0% +and that leads to this really fun area + + + align:start position:0% +and that leads to this really fun area +of math computer science + + align:start position:0% +of math computer science + + + align:start position:0% +of math computer science +whatever called discrete differential + + align:start position:0% +whatever called discrete differential + + + align:start position:0% +whatever called discrete differential +geometry which sounds like a + + align:start position:0% +geometry which sounds like a + + + align:start position:0% +geometry which sounds like a +contradiction in terms + + align:start position:0% +contradiction in terms + + + align:start position:0% +contradiction in terms +um and it's something that we cover in + + align:start position:0% +um and it's something that we cover in + + + align:start position:0% +um and it's something that we cover in +quite some detail in this course so we + + align:start position:0% +quite some detail in this course so we + + + align:start position:0% +quite some detail in this course so we +build up + + align:start position:0% +build up + + + align:start position:0% +build up +all of calculus the only calculations + + align:start position:0% +all of calculus the only calculations + + + align:start position:0% +all of calculus the only calculations +you're allowed to do + + align:start position:0% +you're allowed to do + + + align:start position:0% +you're allowed to do +are on the vertices edges and triangles + + align:start position:0% +are on the vertices edges and triangles + + + align:start position:0% +are on the vertices edges and triangles +of a triangle mesh + + align:start position:0% +of a triangle mesh + + + align:start position:0% +of a triangle mesh +uh and get pretty far including some + + align:start position:0% +uh and get pretty far including some + + + align:start position:0% +uh and get pretty far including some +some constructions of topology like the + + align:start position:0% +some constructions of topology like the + + + align:start position:0% +some constructions of topology like the +durant complex and so on + + align:start position:0% +durant complex and so on + + + align:start position:0% +durant complex and so on +i would argue actually if you take our + + align:start position:0% +i would argue actually if you take our + + + align:start position:0% +i would argue actually if you take our +course and then the differential + + align:start position:0% +course and then the differential + + + align:start position:0% +course and then the differential +geometry courses in that department + + align:start position:0% +geometry courses in that department + + + align:start position:0% +geometry courses in that department +somehow some of the indices and + + align:start position:0% +somehow some of the indices and + + + align:start position:0% +somehow some of the indices and +headaches that you often encounter + + align:start position:0% +headaches that you often encounter + + + align:start position:0% +headaches that you often encounter +in that world are much more concrete + + align:start position:0% +in that world are much more concrete + + + align:start position:0% +in that world are much more concrete +when you try to make them work on a mesh + + align:start position:0% +when you try to make them work on a mesh + + + align:start position:0% +when you try to make them work on a mesh +in any event i think i've already spent + + align:start position:0% +in any event i think i've already spent + + + align:start position:0% +in any event i think i've already spent +all of my time i can tell you a little + + align:start position:0% +all of my time i can tell you a little + + + align:start position:0% +all of my time i can tell you a little +bit about uh + + align:start position:0% +bit about uh + + + align:start position:0% +bit about uh +research uh in our group um so i + + align:start position:0% +research uh in our group um so i + + + align:start position:0% +research uh in our group um so i +leave kind of a weird extremely broad + + align:start position:0% +leave kind of a weird extremely broad + + + align:start position:0% +leave kind of a weird extremely broad +group where some of our students are + + align:start position:0% +group where some of our students are + + + align:start position:0% +group where some of our students are +essentially theory students + + align:start position:0% +essentially theory students + + + align:start position:0% +essentially theory students +what's your keyboard i'm sorry it was a + + align:start position:0% +what's your keyboard i'm sorry it was a + + + align:start position:0% +what's your keyboard i'm sorry it was a +reflex + + align:start position:0% +reflex + + + align:start position:0% +reflex +um but it was fast uh all right so + + align:start position:0% +um but it was fast uh all right so + + + align:start position:0% +um but it was fast uh all right so +we have some students whose background + + align:start position:0% +we have some students whose background + + + align:start position:0% +we have some students whose background +is not other ones that like we're in + + align:start position:0% +is not other ones that like we're in + + + align:start position:0% +is not other ones that like we're in +autonomous driving industry and decided + + align:start position:0% +autonomous driving industry and decided + + + align:start position:0% +autonomous driving industry and decided +to come back and + + align:start position:0% +to come back and + + + align:start position:0% +to come back and +uh uh work in research and so + + align:start position:0% +uh uh work in research and so + + + align:start position:0% +uh uh work in research and so +because of that we have this extremely + + align:start position:0% +because of that we have this extremely + + + align:start position:0% +because of that we have this extremely +broad set of research problems + + align:start position:0% +broad set of research problems + + + align:start position:0% +broad set of research problems +everything from + + align:start position:0% +everything from + + + align:start position:0% +everything from +the sort of classic machine learning + + align:start position:0% +the sort of classic machine learning + + + align:start position:0% +the sort of classic machine learning +problems you might encounter in + + align:start position:0% +problems you might encounter in + + + align:start position:0% +problems you might encounter in +in geometry world like if i have a + + align:start position:0% +in geometry world like if i have a + + + align:start position:0% +in geometry world like if i have a +self-driving car and i want to identify + + align:start position:0% +self-driving car and i want to identify + + + align:start position:0% +self-driving car and i want to identify +pedestrians and + + align:start position:0% +pedestrians and + + + align:start position:0% +pedestrians and +other cars on the road in an efficient + + align:start position:0% +other cars on the road in an efficient + + + align:start position:0% +other cars on the road in an efficient +and accurate fashion + + align:start position:0% +and accurate fashion + + + align:start position:0% +and accurate fashion +um by the way part of that is machine + + align:start position:0% +um by the way part of that is machine + + + align:start position:0% +um by the way part of that is machine +learning and deep + + align:start position:0% +learning and deep + + + align:start position:0% +learning and deep +whatever but there's another part which + + align:start position:0% +whatever but there's another part which + + + align:start position:0% +whatever but there's another part which +is algorithms because actually what + + align:start position:0% +is algorithms because actually what + + + align:start position:0% +is algorithms because actually what +comes into your lidar scanner + + align:start position:0% +comes into your lidar scanner + + + align:start position:0% +comes into your lidar scanner +is on the order of like thousands of + + align:start position:0% +is on the order of like thousands of + + + align:start position:0% +is on the order of like thousands of +points and some + + align:start position:0% +points and some + + + align:start position:0% +points and some +minuscule fraction of time and time + + align:start position:0% +minuscule fraction of time and time + + + align:start position:0% +minuscule fraction of time and time +complexity + + align:start position:0% +complexity + + + align:start position:0% +complexity +of your learning algorithm actually is + + align:start position:0% +of your learning algorithm actually is + + + align:start position:0% +of your learning algorithm actually is +really critical to get right + + align:start position:0% +really critical to get right + + + align:start position:0% +really critical to get right +and something that there are a lot of + + align:start position:0% +and something that there are a lot of + + + align:start position:0% +and something that there are a lot of +open problems right now because it's + + align:start position:0% +open problems right now because it's + + + align:start position:0% +open problems right now because it's +really not compatible with the hardware + + align:start position:0% +really not compatible with the hardware + + + align:start position:0% +really not compatible with the hardware +architecture that + + align:start position:0% +architecture that + + + align:start position:0% +architecture that +these cars often use uh we also look at + + align:start position:0% +these cars often use uh we also look at + + + align:start position:0% +these cars often use uh we also look at +geometry problems like if i give you + + align:start position:0% +geometry problems like if i give you + + + align:start position:0% +geometry problems like if i give you +data can i find a geometric structure + + align:start position:0% +data can i find a geometric structure + + + align:start position:0% +data can i find a geometric structure +uh so a sort of classic example of + + align:start position:0% +uh so a sort of classic example of + + + align:start position:0% +uh so a sort of classic example of +natural language processing + + align:start position:0% +natural language processing + + + align:start position:0% +natural language processing +where we use words like near and far you + + align:start position:0% +where we use words like near and far you + + + align:start position:0% +where we use words like near and far you +know in terms of semantics and meaning + + align:start position:0% +know in terms of semantics and meaning + + + align:start position:0% +know in terms of semantics and meaning +all the time + + align:start position:0% +all the time + + + align:start position:0% +all the time +the question is can we actually find an + + align:start position:0% +the question is can we actually find an + + + align:start position:0% +the question is can we actually find an +embedding of our + + align:start position:0% +embedding of our + + + align:start position:0% +embedding of our +you know word data into a geometric + + align:start position:0% +you know word data into a geometric + + + align:start position:0% +you know word data into a geometric +space to facilitate the kind of + + align:start position:0% +space to facilitate the kind of + + + align:start position:0% +space to facilitate the kind of +statistical algorithms that we care + + align:start position:0% +statistical algorithms that we care + + + align:start position:0% +statistical algorithms that we care +about + + align:start position:0% +about + + + align:start position:0% +about +and of course we apply geometry to lots + + align:start position:0% +and of course we apply geometry to lots + + + align:start position:0% +and of course we apply geometry to lots +of practical problems everything from + + align:start position:0% +of practical problems everything from + + + align:start position:0% +of practical problems everything from +meshing and scientific computing which i + + align:start position:0% +meshing and scientific computing which i + + + align:start position:0% +meshing and scientific computing which i +think is sort of a classic + + align:start position:0% +think is sort of a classic + + + align:start position:0% +think is sort of a classic +uh one in fact i think we're the first + + align:start position:0% +uh one in fact i think we're the first + + + align:start position:0% +uh one in fact i think we're the first +group that sort of enumerated all the + + align:start position:0% +group that sort of enumerated all the + + + align:start position:0% +group that sort of enumerated all the +cool things that they happened to + + align:start position:0% +cool things that they happened to + + + align:start position:0% +cool things that they happened to +draw matches um which is the sort of + + align:start position:0% +draw matches um which is the sort of + + + align:start position:0% +draw matches um which is the sort of +bottom finger here i should share this + + align:start position:0% +bottom finger here i should share this + + + align:start position:0% +bottom finger here i should share this +with you because there's some fun things + + align:start position:0% +with you because there's some fun things + + + align:start position:0% +with you because there's some fun things +to look at there + + align:start position:0% +to look at there + + + align:start position:0% +to look at there +um to uh other practical problems like + + align:start position:0% +um to uh other practical problems like + + + align:start position:0% +um to uh other practical problems like +taking a + + align:start position:0% +taking a + + + align:start position:0% +taking a +you know eric took a zebra and folded it + + align:start position:0% +you know eric took a zebra and folded it + + + align:start position:0% +you know eric took a zebra and folded it +we can take a zebra and + + align:start position:0% +we can take a zebra and + + + align:start position:0% +we can take a zebra and +move its texture onto a cat or a pig or + + align:start position:0% +move its texture onto a cat or a pig or + + + align:start position:0% +move its texture onto a cat or a pig or +actually + + align:start position:0% +actually + + + align:start position:0% +actually +off the side of the screen but if you + + align:start position:0% +off the side of the screen but if you + + + align:start position:0% +off the side of the screen but if you +download the paper is it all for the 3d + + align:start position:0% +download the paper is it all for the 3d + + + align:start position:0% +download the paper is it all for the 3d +scan + + align:start position:0% +scan + + + align:start position:0% +scan +of one of my gratitude um so + + align:start position:0% +of one of my gratitude um so + + + align:start position:0% +of one of my gratitude um so +in any event in uh my five minutes + + align:start position:0% +in any event in uh my five minutes + + + align:start position:0% +in any event in uh my five minutes +remaining here i thought + + align:start position:0% +remaining here i thought + + + align:start position:0% +remaining here i thought +i'd dig into a little bit of a detail of + + align:start position:0% +i'd dig into a little bit of a detail of + + + align:start position:0% +i'd dig into a little bit of a detail of +two or maybe one application depending + + align:start position:0% +two or maybe one application depending + + + align:start position:0% +two or maybe one application depending +on when jason and eric get bored uh + + align:start position:0% +on when jason and eric get bored uh + + + align:start position:0% +on when jason and eric get bored uh +uh and essentially my message for you + + align:start position:0% +uh and essentially my message for you + + + align:start position:0% +uh and essentially my message for you +guys is of course + + align:start position:0% +guys is of course + + + align:start position:0% +guys is of course +you know it's not broken i'm not really + + align:start position:0% +you know it's not broken i'm not really + + + align:start position:0% +you know it's not broken i'm not really +a central + + align:start position:0% +a central + + + align:start position:0% +a central +cs theory group member here at mit uh + + align:start position:0% +cs theory group member here at mit uh + + + align:start position:0% +cs theory group member here at mit uh +but unfortunately for you guys 6.06 is + + align:start position:0% +but unfortunately for you guys 6.06 is + + + align:start position:0% +but unfortunately for you guys 6.06 is +unavoidable even if you want to go into + + align:start position:0% +unavoidable even if you want to go into + + + align:start position:0% +unavoidable even if you want to go into +deep learning statistics whatever data + + align:start position:0% +deep learning statistics whatever data + + + align:start position:0% +deep learning statistics whatever data +science + + align:start position:0% +science + + + align:start position:0% +science +you're going to encounter the material + + align:start position:0% +you're going to encounter the material + + + align:start position:0% +you're going to encounter the material +that you've seen in this course and in + + align:start position:0% +that you've seen in this course and in + + + align:start position:0% +that you've seen in this course and in +fact it's really + + align:start position:0% +fact it's really + + + align:start position:0% +fact it's really +the bread and butter of just about + + align:start position:0% +the bread and butter of just about + + + align:start position:0% +the bread and butter of just about +everything everybody does here in this + + align:start position:0% +everything everybody does here in this + + + align:start position:0% +everything everybody does here in this +data center + + align:start position:0% +data center + + + align:start position:0% +data center +so i thought i'd give you two quick + + align:start position:0% +so i thought i'd give you two quick + + + align:start position:0% +so i thought i'd give you two quick +examples one of which lifted from my + + align:start position:0% +examples one of which lifted from my + + + align:start position:0% +examples one of which lifted from my +teaching one for my research + + align:start position:0% +teaching one for my research + + + align:start position:0% +teaching one for my research +so uh if you continue with me next fall + + align:start position:0% +so uh if you continue with me next fall + + + align:start position:0% +so uh if you continue with me next fall +uh we'll teach + + align:start position:0% +uh we'll teach + + + align:start position:0% +uh we'll teach +6837 which is the intro to computer + + align:start position:0% +6837 which is the intro to computer + + + align:start position:0% +6837 which is the intro to computer +graphics course + + align:start position:0% +graphics course + + + align:start position:0% +graphics course +one thing that's always amazing to + + align:start position:0% +one thing that's always amazing to + + + align:start position:0% +one thing that's always amazing to +students is these algorithms that + + align:start position:0% +students is these algorithms that + + + align:start position:0% +students is these algorithms that +produce these + + align:start position:0% +produce these + + + align:start position:0% +produce these +images can fit in about 10 20 lines of + + align:start position:0% +images can fit in about 10 20 lines of + + + align:start position:0% +images can fit in about 10 20 lines of +code um so a really + + align:start position:0% +code um so a really + + + align:start position:0% +code um so a really +this is totally facetious because if you + + align:start position:0% +this is totally facetious because if you + + + align:start position:0% +this is totally facetious because if you +want those beautiful images and you use + + align:start position:0% +want those beautiful images and you use + + + align:start position:0% +want those beautiful images and you use +those 20 lines of code + + align:start position:0% +those 20 lines of code + + + align:start position:0% +those 20 lines of code +you'll be waiting until the universe to + + align:start position:0% +you'll be waiting until the universe to + + + align:start position:0% +you'll be waiting until the universe to +actually compute these things but in any + + align:start position:0% +actually compute these things but in any + + + align:start position:0% +actually compute these things but in any +event uh one nice one for rendering so + + align:start position:0% +event uh one nice one for rendering so + + + align:start position:0% +event uh one nice one for rendering so +drawing a bunch of shapes on your screen + + align:start position:0% +drawing a bunch of shapes on your screen + + + align:start position:0% +drawing a bunch of shapes on your screen +something called ray casting + + align:start position:0% +something called ray casting + + + align:start position:0% +something called ray casting +um or it's better known cousin ray + + align:start position:0% +um or it's better known cousin ray + + + align:start position:0% +um or it's better known cousin ray +tracing + + align:start position:0% +tracing + + + align:start position:0% +tracing +typically the difference is whether your + + align:start position:0% +typically the difference is whether your + + + align:start position:0% +typically the difference is whether your +rays can bounce off of the surface and + + align:start position:0% +rays can bounce off of the surface and + + + align:start position:0% +rays can bounce off of the surface and +have a secondary thing + + align:start position:0% +have a secondary thing + + + align:start position:0% +have a secondary thing +uh right so here's the raycasting + + align:start position:0% +uh right so here's the raycasting + + + align:start position:0% +uh right so here's the raycasting +algorithm let's say i have a scene + + align:start position:0% +algorithm let's say i have a scene + + + align:start position:0% +algorithm let's say i have a scene +built out of spheres and cues i'm gonna + + align:start position:0% +built out of spheres and cues i'm gonna + + + align:start position:0% +built out of spheres and cues i'm gonna +have a for loop over every pixel + + align:start position:0% +have a for loop over every pixel + + + align:start position:0% +have a for loop over every pixel +on the computer screen for every pixel i + + align:start position:0% +on the computer screen for every pixel i + + + align:start position:0% +on the computer screen for every pixel i +got to discover what color that should + + align:start position:0% +got to discover what color that should + + + align:start position:0% +got to discover what color that should +be + + align:start position:0% +be + + + align:start position:0% +be +so i shoot a ray from my eyeball through + + align:start position:0% +so i shoot a ray from my eyeball through + + + align:start position:0% +so i shoot a ray from my eyeball through +that pixel + + align:start position:0% +that pixel + + + align:start position:0% +that pixel +and find the first object that it runs + + align:start position:0% +and find the first object that it runs + + + align:start position:0% +and find the first object that it runs +into + + align:start position:0% +into + + + align:start position:0% +into +it's not so hard to intersect a line + + align:start position:0% +it's not so hard to intersect a line + + + align:start position:0% +it's not so hard to intersect a line +with a sphere or a line in the cube + + align:start position:0% +with a sphere or a line in the cube + + + align:start position:0% +with a sphere or a line in the cube +so what is that algorithm well i've + + align:start position:0% +so what is that algorithm well i've + + + align:start position:0% +so what is that algorithm well i've +given it to you on the screen here + + align:start position:0% +given it to you on the screen here + + + align:start position:0% +given it to you on the screen here +not too bad to think about and i think + + align:start position:0% +not too bad to think about and i think + + + align:start position:0% +not too bad to think about and i think +you guys are all extremely well equipped + + align:start position:0% +you guys are all extremely well equipped + + + align:start position:0% +you guys are all extremely well equipped +to analyze the runtime of this + + align:start position:0% +to analyze the runtime of this + + + align:start position:0% +to analyze the runtime of this +which is roughly the uh number of pixels + + align:start position:0% +which is roughly the uh number of pixels + + + align:start position:0% +which is roughly the uh number of pixels +times the number of objects right + + align:start position:0% +times the number of objects right + + + align:start position:0% +times the number of objects right +because for every pixel + + align:start position:0% +because for every pixel + + + align:start position:0% +because for every pixel +i gotta decide what object the ray out + + align:start position:0% +i gotta decide what object the ray out + + + align:start position:0% +i gotta decide what object the ray out +of my eyeball hits first + + align:start position:0% +of my eyeball hits first + + + align:start position:0% +of my eyeball hits first +so i need a for loop over every object + + align:start position:0% +so i need a for loop over every object + + + align:start position:0% +so i need a for loop over every object +make sense + + align:start position:0% +make sense + + + align:start position:0% +make sense +cool so let's uh look at sort of a basic + + align:start position:0% +cool so let's uh look at sort of a basic + + + align:start position:0% +cool so let's uh look at sort of a basic +uh rendering + + align:start position:0% +uh rendering + + + align:start position:0% +uh rendering +problem in fact eric already uh secretly + + align:start position:0% +problem in fact eric already uh secretly + + + align:start position:0% +problem in fact eric already uh secretly +stuck this one + + align:start position:0% +stuck this one + + + align:start position:0% +stuck this one +in here so there's a very famous 3d + + align:start position:0% +in here so there's a very famous 3d + + + align:start position:0% +in here so there's a very famous 3d +model called the stanford bunny + + align:start position:0% +model called the stanford bunny + + + align:start position:0% +model called the stanford bunny +um the stanford bunny is actually a + + align:start position:0% +um the stanford bunny is actually a + + + align:start position:0% +um the stanford bunny is actually a +great example of a simplicial complex + + align:start position:0% +great example of a simplicial complex + + + align:start position:0% +great example of a simplicial complex +it's + + align:start position:0% +it's + + + align:start position:0% +it's +in fact a manifold one triangulated + + align:start position:0% +in fact a manifold one triangulated + + + align:start position:0% +in fact a manifold one triangulated +surface + + align:start position:0% +surface + + + align:start position:0% +surface +um actually i'm not sure it's manifold + + align:start position:0% +um actually i'm not sure it's manifold + + + align:start position:0% +um actually i'm not sure it's manifold +in its original + + align:start position:0% +in its original + + + align:start position:0% +in its original +form but but usually it is uh and this + + align:start position:0% +form but but usually it is uh and this + + + align:start position:0% +form but but usually it is uh and this +uh innocent looking + + align:start position:0% +uh innocent looking + + + align:start position:0% +uh innocent looking +extremely famous 3d model uh is actually + + align:start position:0% +extremely famous 3d model uh is actually + + + align:start position:0% +extremely famous 3d model uh is actually +quite uh pernicious + + align:start position:0% +quite uh pernicious + + + align:start position:0% +quite uh pernicious +it's composed of 69 000 + + align:start position:0% +it's composed of 69 000 + + + align:start position:0% +it's composed of 69 000 +triangles and if i wanted 1080p like you + + align:start position:0% +triangles and if i wanted 1080p like you + + + align:start position:0% +triangles and if i wanted 1080p like you +know a high def + + align:start position:0% +know a high def + + + align:start position:0% +know a high def +uh rendering of my triangle then of + + align:start position:0% +uh rendering of my triangle then of + + + align:start position:0% +uh rendering of my triangle then of +course there's there's two million + + align:start position:0% +course there's there's two million + + + align:start position:0% +course there's there's two million +pixels on the screen + + align:start position:0% +pixels on the screen + + + align:start position:0% +pixels on the screen +so if we look at our big o expression + + align:start position:0% +so if we look at our big o expression + + + align:start position:0% +so if we look at our big o expression +roughly our computation time scales like + + align:start position:0% +roughly our computation time scales like + + + align:start position:0% +roughly our computation time scales like +the product of those two big numbers + + align:start position:0% +the product of those two big numbers + + + align:start position:0% +the product of those two big numbers +uh so just to render this ugly gray + + align:start position:0% +uh so just to render this ugly gray + + + align:start position:0% +uh so just to render this ugly gray +bunny it takes me + + align:start position:0% +bunny it takes me + + + align:start position:0% +bunny it takes me +a pretty large amount of time yeah and + + align:start position:0% +a pretty large amount of time yeah and + + + align:start position:0% +a pretty large amount of time yeah and +in fact uh the real + + align:start position:0% +in fact uh the real + + + align:start position:0% +in fact uh the real +by the way the bunny is like this famous + + align:start position:0% +by the way the bunny is like this famous + + + align:start position:0% +by the way the bunny is like this famous +test case in computer graphics so if you + + align:start position:0% +test case in computer graphics so if you + + + align:start position:0% +test case in computer graphics so if you +take my class you'll be rendering + + align:start position:0% +take my class you'll be rendering + + + align:start position:0% +take my class you'll be rendering +bunnies all day + + align:start position:0% +bunnies all day + + + align:start position:0% +bunnies all day +um you know the reality is we don't want + + align:start position:0% +um you know the reality is we don't want + + + align:start position:0% +um you know the reality is we don't want +just like gray flat shaded bunnies we + + align:start position:0% +just like gray flat shaded bunnies we + + + align:start position:0% +just like gray flat shaded bunnies we +want + + align:start position:0% +want + + + align:start position:0% +want +bunnies that are transparent and + + align:start position:0% +bunnies that are transparent and + + + align:start position:0% +bunnies that are transparent and +reflecting stuff + + align:start position:0% +reflecting stuff + + + align:start position:0% +reflecting stuff +and you know i shoot my bunny with a + + align:start position:0% +and you know i shoot my bunny with a + + + align:start position:0% +and you know i shoot my bunny with a +bullet and it shatters into a million + + align:start position:0% +bullet and it shatters into a million + + + align:start position:0% +bullet and it shatters into a million +pieces and all these cool things + + align:start position:0% +pieces and all these cool things + + + align:start position:0% +pieces and all these cool things +so of course that raycasting algorithm + + align:start position:0% +so of course that raycasting algorithm + + + align:start position:0% +so of course that raycasting algorithm +and each one of these new graphics + + align:start position:0% +and each one of these new graphics + + + align:start position:0% +and each one of these new graphics +features i add + + align:start position:0% +features i add + + + align:start position:0% +features i add +only adds the time complexity of of the + + align:start position:0% +only adds the time complexity of of the + + + align:start position:0% +only adds the time complexity of of the +technique uh that i implemented + + align:start position:0% +technique uh that i implemented + + + align:start position:0% +technique uh that i implemented +so pretty quickly and indeed if you + + align:start position:0% +so pretty quickly and indeed if you + + + align:start position:0% +so pretty quickly and indeed if you +write your own ray tracer at home which + + align:start position:0% +write your own ray tracer at home which + + + align:start position:0% +write your own ray tracer at home which +i strongly encourage you to do + + align:start position:0% +i strongly encourage you to do + + + align:start position:0% +i strongly encourage you to do +what you'll discover uh is that a + + align:start position:0% +what you'll discover uh is that a + + + align:start position:0% +what you'll discover uh is that a +teleslope would be the + + align:start position:0% +teleslope would be the + + + align:start position:0% +teleslope would be the +technical phrase uh so what is our way + + align:start position:0% +technical phrase uh so what is our way + + + align:start position:0% +technical phrase uh so what is our way +out of this well + + align:start position:0% +out of this well + + + align:start position:0% +out of this well +if you take uh a37 you'll see that our + + align:start position:0% +if you take uh a37 you'll see that our + + + align:start position:0% +if you take uh a37 you'll see that our +way out of these problems and graphics + + align:start position:0% +way out of these problems and graphics + + + align:start position:0% +way out of these problems and graphics +is data structures and algorithms + + align:start position:0% +is data structures and algorithms + + + align:start position:0% +is data structures and algorithms +it's completely unavoidable so for + + align:start position:0% +it's completely unavoidable so for + + + align:start position:0% +it's completely unavoidable so for +instance obviously we spent + + align:start position:0% +instance obviously we spent + + + align:start position:0% +instance obviously we spent +quite a bit of time in this course uh + + align:start position:0% +quite a bit of time in this course uh + + + align:start position:0% +quite a bit of time in this course uh +talking about avl trees + + align:start position:0% +talking about avl trees + + + align:start position:0% +talking about avl trees +uh in age seven we'll spend a big chunk + + align:start position:0% +uh in age seven we'll spend a big chunk + + + align:start position:0% +uh in age seven we'll spend a big chunk +of our tours talking about space + + align:start position:0% +of our tours talking about space + + + align:start position:0% +of our tours talking about space +partitioning trees + + align:start position:0% +partitioning trees + + + align:start position:0% +partitioning trees +uh so here i've actually forgot what + + align:start position:0% +uh so here i've actually forgot what + + + align:start position:0% +uh so here i've actually forgot what +kind of tree this + + align:start position:0% +kind of tree this + + + align:start position:0% +kind of tree this +is i think it's a kg tree + + align:start position:0% +is i think it's a kg tree + + + align:start position:0% +is i think it's a kg tree +doesn't matter um in any event uh one + + align:start position:0% +doesn't matter um in any event uh one + + + align:start position:0% +doesn't matter um in any event uh one +thing i could do is take all the + + align:start position:0% +thing i could do is take all the + + + align:start position:0% +thing i could do is take all the +uh triangles in my bunny and i could put + + align:start position:0% +uh triangles in my bunny and i could put + + + align:start position:0% +uh triangles in my bunny and i could put +the entire bunny in a giant cube + + align:start position:0% +the entire bunny in a giant cube + + + align:start position:0% +the entire bunny in a giant cube +right then with the property that the + + align:start position:0% +right then with the property that the + + + align:start position:0% +right then with the property that the +cube is outside of my let's say i + + align:start position:0% +cube is outside of my let's say i + + + align:start position:0% +cube is outside of my let's say i +cast a ray and the ray doesn't touch the + + align:start position:0% +cast a ray and the ray doesn't touch the + + + align:start position:0% +cast a ray and the ray doesn't touch the +cube + + align:start position:0% +cube + + + align:start position:0% +cube +can the ray touch the bunny no right + + align:start position:0% +can the ray touch the bunny no right + + + align:start position:0% +can the ray touch the bunny no right +zing's right pass it + + align:start position:0% +zing's right pass it + + + align:start position:0% +zing's right pass it +right so suddenly i just saved myself a + + align:start position:0% +right so suddenly i just saved myself a + + + align:start position:0% +right so suddenly i just saved myself a +lot of computation time right i don't + + align:start position:0% +lot of computation time right i don't + + + align:start position:0% +lot of computation time right i don't +have to iterate over all the triangles + + align:start position:0% +have to iterate over all the triangles + + + align:start position:0% +have to iterate over all the triangles +inside of the bunny to see whether they + + align:start position:0% +inside of the bunny to see whether they + + + align:start position:0% +inside of the bunny to see whether they +hit the ray or not because i already + + align:start position:0% +hit the ray or not because i already + + + align:start position:0% +hit the ray or not because i already +convinced myself by this conservative + + align:start position:0% +convinced myself by this conservative + + + align:start position:0% +convinced myself by this conservative +test + + align:start position:0% +test + + + align:start position:0% +test +that i didn't hit even the bounding box + + align:start position:0% +that i didn't hit even the bounding box + + + align:start position:0% +that i didn't hit even the bounding box +of the whole body + + align:start position:0% +of the whole body + + + align:start position:0% +of the whole body +yeah well that's sort of a nice order + + align:start position:0% +yeah well that's sort of a nice order + + + align:start position:0% +yeah well that's sort of a nice order +one speed up but depending on how big + + align:start position:0% +one speed up but depending on how big + + + align:start position:0% +one speed up but depending on how big +the bunny + + align:start position:0% +the bunny + + + align:start position:0% +the bunny +is relative to the size of my rendered + + align:start position:0% +is relative to the size of my rendered + + + align:start position:0% +is relative to the size of my rendered +image that might not be a super useful + + align:start position:0% +image that might not be a super useful + + + align:start position:0% +image that might not be a super useful +uh efficiency test but of course what + + align:start position:0% +uh efficiency test but of course what + + + align:start position:0% +uh efficiency test but of course what +could i do i could take the + + align:start position:0% +could i do i could take the + + + align:start position:0% +could i do i could take the +box containing the bunny i could slice + + align:start position:0% +box containing the bunny i could slice + + + align:start position:0% +box containing the bunny i could slice +it in half and i would say it does my + + align:start position:0% +it in half and i would say it does my + + + align:start position:0% +it in half and i would say it does my +you know does my ray hit the front or + + align:start position:0% +you know does my ray hit the front or + + + align:start position:0% +you know does my ray hit the front or +the back of the bunny or maybe both + + align:start position:0% +the back of the bunny or maybe both + + + align:start position:0% +the back of the bunny or maybe both +that's where you got it that's where + + align:start position:0% +that's where you got it that's where + + + align:start position:0% +that's where you got it that's where +things get done + + align:start position:0% +things get done + + + align:start position:0% +things get done +um and and so on so now you have this + + align:start position:0% +um and and so on so now you have this + + + align:start position:0% +um and and so on so now you have this +nice recursive + + align:start position:0% +nice recursive + + + align:start position:0% +nice recursive +tree structure where i keep taking the + + align:start position:0% +tree structure where i keep taking the + + + align:start position:0% +tree structure where i keep taking the +box containing my bunny and chopping it + + align:start position:0% +box containing my bunny and chopping it + + + align:start position:0% +box containing my bunny and chopping it +in half + + align:start position:0% +in half + + + align:start position:0% +in half +and placing uh in some sense usually the + + align:start position:0% +and placing uh in some sense usually the + + + align:start position:0% +and placing uh in some sense usually the +the triangles maybe not the leaves of my + + align:start position:0% +the triangles maybe not the leaves of my + + + align:start position:0% +the triangles maybe not the leaves of my +tree but that's exactly that that's + + align:start position:0% +tree but that's exactly that that's + + + align:start position:0% +tree but that's exactly that that's +probably good enough + + align:start position:0% +probably good enough + + + align:start position:0% +probably good enough +and you get a structure like what you + + align:start position:0% +and you get a structure like what you + + + align:start position:0% +and you get a structure like what you +see on the uh the screen here + + align:start position:0% +see on the uh the screen here + + + align:start position:0% +see on the uh the screen here +and why should you do that well remember + + align:start position:0% +and why should you do that well remember + + + align:start position:0% +and why should you do that well remember +it takes sort of pn + + align:start position:0% +it takes sort of pn + + + align:start position:0% +it takes sort of pn +time to render my image of my bunny + + align:start position:0% +time to render my image of my bunny + + + align:start position:0% +time to render my image of my bunny +normally + + align:start position:0% +normally + + + align:start position:0% +normally +well now the picture is actually + + align:start position:0% +well now the picture is actually + + + align:start position:0% +well now the picture is actually +misleadingly suggestive + + align:start position:0% +misleadingly suggestive + + + align:start position:0% +misleadingly suggestive +but you might think that maybe it takes + + align:start position:0% +but you might think that maybe it takes + + + align:start position:0% +but you might think that maybe it takes +roughly remember and as + + align:start position:0% +roughly remember and as + + + align:start position:0% +roughly remember and as +the number of objects in my scene p + + align:start position:0% +the number of objects in my scene p + + + align:start position:0% +the number of objects in my scene p +login time to render my bunny now + + align:start position:0% +login time to render my bunny now + + + align:start position:0% +login time to render my bunny now +because i can kind of traverse + + align:start position:0% +because i can kind of traverse + + + align:start position:0% +because i can kind of traverse +this tree of objects in my scene of + + align:start position:0% +this tree of objects in my scene of + + + align:start position:0% +this tree of objects in my scene of +course notice i put a question mark here + + align:start position:0% +course notice i put a question mark here + + + align:start position:0% +course notice i put a question mark here +and and the devil's in the details here + + align:start position:0% +and and the devil's in the details here + + + align:start position:0% +and and the devil's in the details here +in fact i think computer graphics people + + align:start position:0% +in fact i think computer graphics people + + + align:start position:0% +in fact i think computer graphics people +often believe that the rendering + + align:start position:0% +often believe that the rendering + + + align:start position:0% +often believe that the rendering +algorithm takes + + align:start position:0% +algorithm takes + + + align:start position:0% +algorithm takes +p log in time that's often not possible + + align:start position:0% +p log in time that's often not possible + + + align:start position:0% +p log in time that's often not possible +although kind of there's an interesting + + align:start position:0% +although kind of there's an interesting + + + align:start position:0% +although kind of there's an interesting +question which is that + + align:start position:0% +question which is that + + + align:start position:0% +question which is that +the heuristics they use for building + + align:start position:0% +the heuristics they use for building + + + align:start position:0% +the heuristics they use for building +these sorts of trees often do on average + + align:start position:0% +these sorts of trees often do on average + + + align:start position:0% +these sorts of trees often do on average +give them lock-in time + + align:start position:0% +give them lock-in time + + + align:start position:0% +give them lock-in time +and so there's something about their + + align:start position:0% +and so there's something about their + + + align:start position:0% +and so there's something about their +data that's making this problem easier + + align:start position:0% +data that's making this problem easier + + + align:start position:0% +data that's making this problem easier +than it might seem + + align:start position:0% +than it might seem + + + align:start position:0% +than it might seem +so we'll dig into that a little bit in + + align:start position:0% +so we'll dig into that a little bit in + + + align:start position:0% +so we'll dig into that a little bit in +the graphics class of course you're not + + align:start position:0% +the graphics class of course you're not + + + align:start position:0% +the graphics class of course you're not +going to prove as many pounds as you + + align:start position:0% +going to prove as many pounds as you + + + align:start position:0% +going to prove as many pounds as you +might in a + + align:start position:0% +might in a + + + align:start position:0% +might in a +theory course um but we're certainly + + align:start position:0% +theory course um but we're certainly + + + align:start position:0% +theory course um but we're certainly +building on the intuition that you've + + align:start position:0% +building on the intuition that you've + + + align:start position:0% +building on the intuition that you've +seen in this class + + align:start position:0% +seen in this class + + + align:start position:0% +seen in this class +to build up practical data structures + + align:start position:0% +to build up practical data structures + + + align:start position:0% +to build up practical data structures +and these data structures appear + + align:start position:0% +and these data structures appear + + + align:start position:0% +and these data structures appear +everywhere in computer graphics so for + + align:start position:0% +everywhere in computer graphics so for + + + align:start position:0% +everywhere in computer graphics so for +instance directive a6 + + align:start position:0% +instance directive a6 + + + align:start position:0% +instance directive a6 +black directed acyclic graphs appear + + align:start position:0% +black directed acyclic graphs appear + + + align:start position:0% +black directed acyclic graphs appear +all over the place in computer graphics + + align:start position:0% +all over the place in computer graphics + + + align:start position:0% +all over the place in computer graphics +literature to describe 3d + + align:start position:0% +literature to describe 3d + + + align:start position:0% +literature to describe 3d +scenes so for example this classroom is + + align:start position:0% +scenes so for example this classroom is + + + align:start position:0% +scenes so for example this classroom is +a stark reminder of why we need + + align:start position:0% +a stark reminder of why we need + + + align:start position:0% +a stark reminder of why we need +dags and computer graphics because we + + align:start position:0% +dags and computer graphics because we + + + align:start position:0% +dags and computer graphics because we +have all of these empty seats here + + align:start position:0% +have all of these empty seats here + + + align:start position:0% +have all of these empty seats here +and they're all copies of one another so + + align:start position:0% +and they're all copies of one another so + + + align:start position:0% +and they're all copies of one another so +would it make sense for me + + align:start position:0% +would it make sense for me + + + align:start position:0% +would it make sense for me +to store however many like 100 3d models + + align:start position:0% +to store however many like 100 3d models + + + align:start position:0% +to store however many like 100 3d models +of the same chair + + align:start position:0% +of the same chair + + + align:start position:0% +of the same chair +probably not right so instead what do i + + align:start position:0% +probably not right so instead what do i + + + align:start position:0% +probably not right so instead what do i +do i have + + align:start position:0% +do i have + + + align:start position:0% +do i have +i store one instance of a chair and then + + align:start position:0% +i store one instance of a chair and then + + + align:start position:0% +i store one instance of a chair and then +some instructions on how to tile it + + align:start position:0% +some instructions on how to tile it + + + align:start position:0% +some instructions on how to tile it +into my entire scene so one way that i + + align:start position:0% +into my entire scene so one way that i + + + align:start position:0% +into my entire scene so one way that i +can do that + + align:start position:0% +can do that + + + align:start position:0% +can do that +is to think of there being a node which + + align:start position:0% +is to think of there being a node which + + + align:start position:0% +is to think of there being a node which +in a graph which knows how to draw one + + align:start position:0% +in a graph which knows how to draw one + + + align:start position:0% +in a graph which knows how to draw one +chair and now i can have a bunch of + + align:start position:0% +chair and now i can have a bunch of + + + align:start position:0% +chair and now i can have a bunch of +different nodes in my scene for all the + + align:start position:0% +different nodes in my scene for all the + + + align:start position:0% +different nodes in my scene for all the +instances of the chair that store like a + + align:start position:0% +instances of the chair that store like a + + + align:start position:0% +instances of the chair that store like a +different transformation for each one + + align:start position:0% +different transformation for each one + + + align:start position:0% +different transformation for each one +so what if you think about the graph + + align:start position:0% +so what if you think about the graph + + + align:start position:0% +so what if you think about the graph +structure here each of those is going to + + align:start position:0% +structure here each of those is going to + + + align:start position:0% +structure here each of those is going to +point + + align:start position:0% +point + + + align:start position:0% +point +into the same 3d model of the chair for + + align:start position:0% +into the same 3d model of the chair for + + + align:start position:0% +into the same 3d model of the chair for +rendering + + align:start position:0% +rendering + + + align:start position:0% +rendering +and that makes a direct and acyclic + + align:start position:0% +and that makes a direct and acyclic + + + align:start position:0% +and that makes a direct and acyclic +graph structure um called a scene graph + + align:start position:0% +graph structure um called a scene graph + + + align:start position:0% +graph structure um called a scene graph +which we'll spend quite a bit of time + + align:start position:0% +which we'll spend quite a bit of time + + + align:start position:0% +which we'll spend quite a bit of time +talking about in a37 how to + + align:start position:0% +talking about in a37 how to + + + align:start position:0% +talking about in a37 how to +traverse construct all that good stuff + + align:start position:0% +traverse construct all that good stuff + + + align:start position:0% +traverse construct all that good stuff +um and there are lots of different + + align:start position:0% +um and there are lots of different + + + align:start position:0% +um and there are lots of different +models of computation + + align:start position:0% +models of computation + + + align:start position:0% +models of computation +in that universe as well um your + + align:start position:0% +in that universe as well um your + + + align:start position:0% +in that universe as well um your +graphics card + + align:start position:0% +graphics card + + + align:start position:0% +graphics card +is a very specific kind of parallel + + align:start position:0% +is a very specific kind of parallel + + + align:start position:0% +is a very specific kind of parallel +processor that's kind of like + + align:start position:0% +processor that's kind of like + + + align:start position:0% +processor that's kind of like +lucille ball on the conveyor belt you + + align:start position:0% +lucille ball on the conveyor belt you + + + align:start position:0% +lucille ball on the conveyor belt you +know hammering at the same object over + + align:start position:0% +know hammering at the same object over + + + align:start position:0% +know hammering at the same object over +and over again + + align:start position:0% +and over again + + + align:start position:0% +and over again +but if you ask it to do anything other + + align:start position:0% +but if you ask it to do anything other + + + align:start position:0% +but if you ask it to do anything other +than one thing it knows how to do it's a + + align:start position:0% +than one thing it knows how to do it's a + + + align:start position:0% +than one thing it knows how to do it's a +bunch of data at a time + + align:start position:0% +bunch of data at a time + + + align:start position:0% +bunch of data at a time +uh then all of your computation grants + + align:start position:0% +uh then all of your computation grants + + + align:start position:0% +uh then all of your computation grants +for health this is called + + align:start position:0% +for health this is called + + + align:start position:0% +for health this is called +single instruction multiple data + + align:start position:0% +single instruction multiple data + + + align:start position:0% +single instruction multiple data +parallelism sim d + + align:start position:0% +parallelism sim d + + + align:start position:0% +parallelism sim d +numerical algorithms matter a lot for + + align:start position:0% +numerical algorithms matter a lot for + + + align:start position:0% +numerical algorithms matter a lot for +things like fluid simulation + + align:start position:0% +things like fluid simulation + + + align:start position:0% +things like fluid simulation +in approximate approximation algorithms + + align:start position:0% +in approximate approximation algorithms + + + align:start position:0% +in approximate approximation algorithms +are quite critical too + + align:start position:0% +are quite critical too + + + align:start position:0% +are quite critical too +um in computer graphics the the + + align:start position:0% +um in computer graphics the the + + + align:start position:0% +um in computer graphics the the +complexity is kind of interesting + + align:start position:0% +complexity is kind of interesting + + + align:start position:0% +complexity is kind of interesting +because of course + + align:start position:0% +because of course + + + align:start position:0% +because of course +your eyeball is sensitive to about 29.97 + + align:start position:0% +your eyeball is sensitive to about 29.97 + + + align:start position:0% +your eyeball is sensitive to about 29.97 +frames per second worth of material + + align:start position:0% +frames per second worth of material + + + align:start position:0% +frames per second worth of material +um you can choose that time to do like + + align:start position:0% +um you can choose that time to do like + + + align:start position:0% +um you can choose that time to do like +really well rendering one object but + + align:start position:0% +really well rendering one object but + + + align:start position:0% +really well rendering one object but +then you take out of the time rendering + + align:start position:0% +then you take out of the time rendering + + + align:start position:0% +then you take out of the time rendering +something else + + align:start position:0% +something else + + + align:start position:0% +something else +so there's kind of an interesting + + align:start position:0% +so there's kind of an interesting + + + align:start position:0% +so there's kind of an interesting +conservation law that you have to + + align:start position:0% +conservation law that you have to + + + align:start position:0% +conservation law that you have to +balance when you solve these kinds of + + align:start position:0% +balance when you solve these kinds of + + + align:start position:0% +balance when you solve these kinds of +problems + + align:start position:0% +problems + + + align:start position:0% +problems +which is an interesting balance now + + align:start position:0% +which is an interesting balance now + + + align:start position:0% +which is an interesting balance now +between like complexity and runtime of + + align:start position:0% +between like complexity and runtime of + + + align:start position:0% +between like complexity and runtime of +your algorithm + + align:start position:0% +your algorithm + + + align:start position:0% +your algorithm +and perception like what things can you + + align:start position:0% +and perception like what things can you + + + align:start position:0% +and perception like what things can you +get away with when you draw a scene + + align:start position:0% +get away with when you draw a scene + + + align:start position:0% +get away with when you draw a scene +and maybe like i can do tons of extra + + align:start position:0% +and maybe like i can do tons of extra + + + align:start position:0% +and maybe like i can do tons of extra +computation to get that extra shadow but + + align:start position:0% +computation to get that extra shadow but + + + align:start position:0% +computation to get that extra shadow but +it's just not worth it so i'll quickly + + align:start position:0% +it's just not worth it so i'll quickly + + + align:start position:0% +it's just not worth it so i'll quickly +sketch out another + + align:start position:0% +sketch out another + + + align:start position:0% +sketch out another +uh completely different application of + + align:start position:0% +uh completely different application of + + + align:start position:0% +uh completely different application of +uh the material that we've covered in + + align:start position:0% +uh the material that we've covered in + + + align:start position:0% +uh the material that we've covered in +6006 from my own research uh + + align:start position:0% +6006 from my own research uh + + + align:start position:0% +6006 from my own research uh +again just like eric i guess in a funny + + align:start position:0% +again just like eric i guess in a funny + + + align:start position:0% +again just like eric i guess in a funny +way both of our groups i think are kind + + align:start position:0% +way both of our groups i think are kind + + + align:start position:0% +way both of our groups i think are kind +of raw in terms of subject material like + + align:start position:0% +of raw in terms of subject material like + + + align:start position:0% +of raw in terms of subject material like +rather than + + align:start position:0% +rather than + + + align:start position:0% +rather than +some of our colleagues have like really + + align:start position:0% +some of our colleagues have like really + + + align:start position:0% +some of our colleagues have like really +laser focused on one + + align:start position:0% +laser focused on one + + + align:start position:0% +laser focused on one +topic or another um another research + + align:start position:0% +topic or another um another research + + + align:start position:0% +topic or another um another research +area that i + + align:start position:0% +area that i + + + align:start position:0% +area that i +sort of backed into uh is the area of + + align:start position:0% +sort of backed into uh is the area of + + + align:start position:0% +sort of backed into uh is the area of +political redistricting um + + align:start position:0% +political redistricting um + + + align:start position:0% +political redistricting um +this is relevant in the united states uh + + align:start position:0% +this is relevant in the united states uh + + + align:start position:0% +this is relevant in the united states uh +recently i've been reading some + + align:start position:0% +recently i've been reading some + + + align:start position:0% +recently i've been reading some +proposals about other countries which is + + align:start position:0% +proposals about other countries which is + + + align:start position:0% +proposals about other countries which is +really interesting how they do this + + align:start position:0% +really interesting how they do this + + + align:start position:0% +really interesting how they do this +stuff + + align:start position:0% +stuff + + + align:start position:0% +stuff +so in the u.s when we vote for people uh + + align:start position:0% +so in the u.s when we vote for people uh + + + align:start position:0% +so in the u.s when we vote for people uh +in congress + + align:start position:0% +in congress + + + align:start position:0% +in congress +by the way not necessarily for president + + align:start position:0% +by the way not necessarily for president + + + align:start position:0% +by the way not necessarily for president +this is a common uh + + align:start position:0% +this is a common uh + + + align:start position:0% +this is a common uh +misconception but uh certainly for for + + align:start position:0% +misconception but uh certainly for for + + + align:start position:0% +misconception but uh certainly for for +congress + + align:start position:0% +congress + + + align:start position:0% +congress +um your state gets divided into little + + align:start position:0% +um your state gets divided into little + + + align:start position:0% +um your state gets divided into little +regions each of which elects one member + + align:start position:0% +regions each of which elects one member + + + align:start position:0% +regions each of which elects one member +of the house + + align:start position:0% +of the house + + + align:start position:0% +of the house +and this there's sort of a subtle + + align:start position:0% +and this there's sort of a subtle + + + align:start position:0% +and this there's sort of a subtle +problem if you're not used to thinking + + align:start position:0% +problem if you're not used to thinking + + + align:start position:0% +problem if you're not used to thinking +about it or one that's like staring you + + align:start position:0% +about it or one that's like staring you + + + align:start position:0% +about it or one that's like staring you +in the face and screaming depending on + + align:start position:0% +in the face and screaming depending on + + + align:start position:0% +in the face and screaming depending on +on + + align:start position:0% +on + + + align:start position:0% +on +how often you read the the news uh in + + align:start position:0% +how often you read the the news uh in + + + align:start position:0% +how often you read the the news uh in +politics which is an issue called + + align:start position:0% +politics which is an issue called + + + align:start position:0% +politics which is an issue called +gerrymandering + + align:start position:0% +gerrymandering + + + align:start position:0% +gerrymandering +where your legislature draws the lines + + align:start position:0% +where your legislature draws the lines + + + align:start position:0% +where your legislature draws the lines +for what area on the map elects + + align:start position:0% +for what area on the map elects + + + align:start position:0% +for what area on the map elects +a member of congress and depending on + + align:start position:0% +a member of congress and depending on + + + align:start position:0% +a member of congress and depending on +how you draw the lines + + align:start position:0% +how you draw the lines + + + align:start position:0% +how you draw the lines +you can engineer different results for + + align:start position:0% +you can engineer different results for + + + align:start position:0% +you can engineer different results for +who's likely to get elected + + align:start position:0% +who's likely to get elected + + + align:start position:0% +who's likely to get elected +so for instance maybe there's some + + align:start position:0% +so for instance maybe there's some + + + align:start position:0% +so for instance maybe there's some +minority i can cluster them all together + + align:start position:0% +minority i can cluster them all together + + + align:start position:0% +minority i can cluster them all together +into one voting district + + align:start position:0% +into one voting district + + + align:start position:0% +into one voting district +then they'll only get the opportunity to + + align:start position:0% +then they'll only get the opportunity to + + + align:start position:0% +then they'll only get the opportunity to +elect one person but + + align:start position:0% +elect one person but + + + align:start position:0% +elect one person but +maybe if i divide the space where they + + align:start position:0% +maybe if i divide the space where they + + + align:start position:0% +maybe if i divide the space where they +live into two i could manage to engineer + + align:start position:0% +live into two i could manage to engineer + + + align:start position:0% +live into two i could manage to engineer +two districts + + align:start position:0% +two districts + + + align:start position:0% +two districts +with a high probability of electing + + align:start position:0% +with a high probability of electing + + + align:start position:0% +with a high probability of electing +somebody with their political interests + + align:start position:0% +somebody with their political interests + + + align:start position:0% +somebody with their political interests +in mind + + align:start position:0% +in mind + + + align:start position:0% +in mind +so it turns out that uh political + + align:start position:0% +so it turns out that uh political + + + align:start position:0% +so it turns out that uh political +redistricting in a broad sense is a + + align:start position:0% +redistricting in a broad sense is a + + + align:start position:0% +redistricting in a broad sense is a +great problem + + align:start position:0% +great problem + + + align:start position:0% +great problem +computationally even if you're a totally + + align:start position:0% +computationally even if you're a totally + + + align:start position:0% +computationally even if you're a totally +heartless theorist there's some really + + align:start position:0% +heartless theorist there's some really + + + align:start position:0% +heartless theorist there's some really +fun problems here + + align:start position:0% +fun problems here + + + align:start position:0% +fun problems here +um so for example the state of iowa we + + align:start position:0% +um so for example the state of iowa we + + + align:start position:0% +um so for example the state of iowa we +all pick on iowa because + + align:start position:0% +all pick on iowa because + + + align:start position:0% +all pick on iowa because +it has a unique law which is that your + + align:start position:0% +it has a unique law which is that your + + + align:start position:0% +it has a unique law which is that your +districts have to be built out of + + align:start position:0% +districts have to be built out of + + + align:start position:0% +districts have to be built out of +counties which are much larger than the + + align:start position:0% +counties which are much larger than the + + + align:start position:0% +counties which are much larger than the +typical census unit so computationally + + align:start position:0% +typical census unit so computationally + + + align:start position:0% +typical census unit so computationally +is easier + + align:start position:0% +is easier + + + align:start position:0% +is easier +but even in iowa um which is a giant + + align:start position:0% +but even in iowa um which is a giant + + + align:start position:0% +but even in iowa um which is a giant +grid with the exception of one + + align:start position:0% +grid with the exception of one + + + align:start position:0% +grid with the exception of one +shift in the middle which is fascinating + + align:start position:0% +shift in the middle which is fascinating + + + align:start position:0% +shift in the middle which is fascinating +um + + align:start position:0% +um + + + align:start position:0% +um +i know a lot of times this is a fun fact + + align:start position:0% +i know a lot of times this is a fun fact + + + align:start position:0% +i know a lot of times this is a fun fact +like literally people were + + align:start position:0% +like literally people were + + + align:start position:0% +like literally people were +making the map of iowa and they work + + align:start position:0% +making the map of iowa and they work + + + align:start position:0% +making the map of iowa and they work +from the bottom up and the top down and + + align:start position:0% +from the bottom up and the top down and + + + align:start position:0% +from the bottom up and the top down and +it meets in the middle and their grids + + align:start position:0% +it meets in the middle and their grids + + + align:start position:0% +it meets in the middle and their grids +were shifted and now we're stuck with + + align:start position:0% +were shifted and now we're stuck with + + + align:start position:0% +were shifted and now we're stuck with +that + + align:start position:0% +that + + + align:start position:0% +that +and it has an interesting effect on the + + align:start position:0% +and it has an interesting effect on the + + + align:start position:0% +and it has an interesting effect on the +topology of your graph because it looks + + align:start position:0% +topology of your graph because it looks + + + align:start position:0% +topology of your graph because it looks +like squares although there's triangles + + align:start position:0% +like squares although there's triangles + + + align:start position:0% +like squares although there's triangles +in the middle + + align:start position:0% +in the middle + + + align:start position:0% +in the middle +uh but in any event um even though + + align:start position:0% +uh but in any event um even though + + + align:start position:0% +uh but in any event um even though +there's only 99 counties in four + + align:start position:0% +there's only 99 counties in four + + + align:start position:0% +there's only 99 counties in four +districts there's approximately + + align:start position:0% +districts there's approximately + + + align:start position:0% +districts there's approximately +quintillions of possible ways you can + + align:start position:0% +quintillions of possible ways you can + + + align:start position:0% +quintillions of possible ways you can +divide that state into four contiguous + + align:start position:0% +divide that state into four contiguous + + + align:start position:0% +divide that state into four contiguous +districts that satisfy the rules as they + + align:start position:0% +districts that satisfy the rules as they + + + align:start position:0% +districts that satisfy the rules as they +were + + align:start position:0% +were + + + align:start position:0% +were +at least if you read them kind of + + align:start position:0% +at least if you read them kind of + + + align:start position:0% +at least if you read them kind of +literally in the uh the the law + + align:start position:0% +literally in the uh the the law + + + align:start position:0% +literally in the uh the the law +um so it seems like computers are useful + + align:start position:0% +um so it seems like computers are useful + + + align:start position:0% +um so it seems like computers are useful +but unfortunately it's a little subtle + + align:start position:0% +but unfortunately it's a little subtle + + + align:start position:0% +but unfortunately it's a little subtle +how right so for instance + + align:start position:0% +how right so for instance + + + align:start position:0% +how right so for instance +there's no single best districting + + align:start position:0% +there's no single best districting + + + align:start position:0% +there's no single best districting +planner out there um + + align:start position:0% +planner out there um + + + align:start position:0% +planner out there um +i can't think of a single state with a + + align:start position:0% +i can't think of a single state with a + + + align:start position:0% +i can't think of a single state with a +law that gives you an objective function + + align:start position:0% +law that gives you an objective function + + + align:start position:0% +law that gives you an objective function +you know similar to + + align:start position:0% +you know similar to + + + align:start position:0% +you know similar to +you know whatever cute you know + + align:start position:0% +you know whatever cute you know + + + align:start position:0% +you know whatever cute you know +characters that we've had in 6706 you + + align:start position:0% +characters that we've had in 6706 you + + + align:start position:0% +characters that we've had in 6706 you +know they often have + + align:start position:0% +know they often have + + + align:start position:0% +know they often have +very clear objectives in life but + + align:start position:0% +very clear objectives in life but + + + align:start position:0% +very clear objectives in life but +unfortunately redistricting uh that's + + align:start position:0% +unfortunately redistricting uh that's + + + align:start position:0% +unfortunately redistricting uh that's +very rarely the case you know you have + + align:start position:0% +very rarely the case you know you have + + + align:start position:0% +very rarely the case you know you have +to balance continuity population balance + + align:start position:0% +to balance continuity population balance + + + align:start position:0% +to balance continuity population balance +compactness all these different things + + align:start position:0% +compactness all these different things + + + align:start position:0% +compactness all these different things +uh reality check number two is that + + align:start position:0% +uh reality check number two is that + + + align:start position:0% +uh reality check number two is that +even if somebody did give you an + + align:start position:0% +even if somebody did give you an + + + align:start position:0% +even if somebody did give you an +objective function for just about any + + align:start position:0% +objective function for just about any + + + align:start position:0% +objective function for just about any +interesting objective function it's very + + align:start position:0% +interesting objective function it's very + + + align:start position:0% +interesting objective function it's very +obvious that + + align:start position:0% +obvious that + + + align:start position:0% +obvious that +generating the best possible districting + + align:start position:0% +generating the best possible districting + + + align:start position:0% +generating the best possible districting +plan is empty hard + + align:start position:0% +plan is empty hard + + + align:start position:0% +plan is empty hard +um and by the way it doesn't even matter + + align:start position:0% +um and by the way it doesn't even matter + + + align:start position:0% +um and by the way it doesn't even matter +because the law + + align:start position:0% +because the law + + + align:start position:0% +because the law +doesn't say that computers have to draw + + align:start position:0% +doesn't say that computers have to draw + + + align:start position:0% +doesn't say that computers have to draw +the best district right so + + align:start position:0% +the best district right so + + + align:start position:0% +the best district right so +even if p equals np you really could + + align:start position:0% +even if p equals np you really could + + + align:start position:0% +even if p equals np you really could +extract the best possible districting + + align:start position:0% +extract the best possible districting + + + align:start position:0% +extract the best possible districting +plan using an algorithm + + align:start position:0% +plan using an algorithm + + + align:start position:0% +plan using an algorithm +um it doesn't mean you have to use it at + + align:start position:0% +um it doesn't mean you have to use it at + + + align:start position:0% +um it doesn't mean you have to use it at +least the way the law is written now + + align:start position:0% +least the way the law is written now + + + align:start position:0% +least the way the law is written now +interestingly this is not true in + + align:start position:0% +interestingly this is not true in + + + align:start position:0% +interestingly this is not true in +certain parts of mexico where they + + align:start position:0% +certain parts of mexico where they + + + align:start position:0% +certain parts of mexico where they +actually make you + + align:start position:0% +actually make you + + + align:start position:0% +actually make you +compare your districting plan against + + align:start position:0% +compare your districting plan against + + + align:start position:0% +compare your districting plan against +the computer-generated one which is + + align:start position:0% +the computer-generated one which is + + + align:start position:0% +the computer-generated one which is +philosophically really interesting + + align:start position:0% +philosophically really interesting + + + align:start position:0% +philosophically really interesting +although practice it doesn't work + + align:start position:0% +although practice it doesn't work + + + align:start position:0% +although practice it doesn't work +terribly + + align:start position:0% +terribly + + + align:start position:0% +terribly +um right so uh our research has studied + + align:start position:0% +um right so uh our research has studied + + + align:start position:0% +um right so uh our research has studied +analysis of distributing plans instead + + align:start position:0% +analysis of distributing plans instead + + + align:start position:0% +analysis of distributing plans instead +so instead of writing a piece of + + align:start position:0% +so instead of writing a piece of + + + align:start position:0% +so instead of writing a piece of +software that takes in your state + + align:start position:0% +software that takes in your state + + + align:start position:0% +software that takes in your state +draws your districts and then you're + + align:start position:0% +draws your districts and then you're + + + align:start position:0% +draws your districts and then you're +done uh instead we ask statistical + + align:start position:0% +done uh instead we ask statistical + + + align:start position:0% +done uh instead we ask statistical +questions about + + align:start position:0% +questions about + + + align:start position:0% +questions about +i propose a districting plan and what + + align:start position:0% +i propose a districting plan and what + + + align:start position:0% +i propose a districting plan and what +does it look like relative to the space + + align:start position:0% +does it look like relative to the space + + + align:start position:0% +does it look like relative to the space +of the uh + + align:start position:0% +of the uh + + + align:start position:0% +of the uh +possibilities um so that of course begs + + align:start position:0% +possibilities um so that of course begs + + + align:start position:0% +possibilities um so that of course begs +the question of what are the + + align:start position:0% +the question of what are the + + + align:start position:0% +the question of what are the +possibilities + + align:start position:0% +possibilities + + + align:start position:0% +possibilities +so these are like connected graph + + align:start position:0% +so these are like connected graph + + + align:start position:0% +so these are like connected graph +partitions meaning you have a graph + + align:start position:0% +partitions meaning you have a graph + + + align:start position:0% +partitions meaning you have a graph +and now you take the vertices and you + + align:start position:0% +and now you take the vertices and you + + + align:start position:0% +and now you take the vertices and you +cluster them together + + align:start position:0% +cluster them together + + + align:start position:0% +cluster them together +in a way where they're connected to one + + align:start position:0% +in a way where they're connected to one + + + align:start position:0% +in a way where they're connected to one +another the one thing that we all agree + + align:start position:0% +another the one thing that we all agree + + + align:start position:0% +another the one thing that we all agree +on + + align:start position:0% +on + + + align:start position:0% +on +actually philosophically it's + + align:start position:0% +actually philosophically it's + + + align:start position:0% +actually philosophically it's +questionable why um + + align:start position:0% +questionable why um + + + align:start position:0% +questionable why um +is that you should be able to start at + + align:start position:0% +is that you should be able to start at + + + align:start position:0% +is that you should be able to start at +any point in your district and walk to + + align:start position:0% +any point in your district and walk to + + + align:start position:0% +any point in your district and walk to +any other one without leaving + + align:start position:0% +any other one without leaving + + + align:start position:0% +any other one without leaving +these days with the internet it's not + + align:start position:0% +these days with the internet it's not + + + align:start position:0% +these days with the internet it's not +clear that that's actually the best + + align:start position:0% +clear that that's actually the best + + + align:start position:0% +clear that that's actually the best +criteria but that's a lot that i think + + align:start position:0% +criteria but that's a lot that i think + + + align:start position:0% +criteria but that's a lot that i think +is never going to get passed in + + align:start position:0% +is never going to get passed in + + + align:start position:0% +is never going to get passed in +in your future so anyway i think i'm out + + align:start position:0% +in your future so anyway i think i'm out + + + align:start position:0% +in your future so anyway i think i'm out +of time so i don't think i'll walk you + + align:start position:0% +of time so i don't think i'll walk you + + + align:start position:0% +of time so i don't think i'll walk you +guys through the + + align:start position:0% +guys through the + + + align:start position:0% +guys through the +the theory here um if maybe i'll leave + + align:start position:0% +the theory here um if maybe i'll leave + + + align:start position:0% +the theory here um if maybe i'll leave +it in the slides uh there's a + + align:start position:0% +it in the slides uh there's a + + + align:start position:0% +it in the slides uh there's a +very simple proof that can show that at + + align:start position:0% +very simple proof that can show that at + + + align:start position:0% +very simple proof that can show that at +least the very simplest thing you might + + align:start position:0% +least the very simplest thing you might + + + align:start position:0% +least the very simplest thing you might +think of for analyzing your districting + + align:start position:0% +think of for analyzing your districting + + + align:start position:0% +think of for analyzing your districting +plan which is to say + + align:start position:0% +plan which is to say + + + align:start position:0% +plan which is to say +you propose a plan and now i want your + + align:start position:0% +you propose a plan and now i want your + + + align:start position:0% +you propose a plan and now i want your +plan to be at least + + align:start position:0% +plan to be at least + + + align:start position:0% +plan to be at least +as good under some axis that's just a + + align:start position:0% +as good under some axis that's just a + + + align:start position:0% +as good under some axis that's just a +randomly drawn one from the space of all + + align:start position:0% +randomly drawn one from the space of all + + + align:start position:0% +randomly drawn one from the space of all +possible connected partitions + + align:start position:0% +possible connected partitions + + + align:start position:0% +possible connected partitions +all possible ways i could draw the lines + + align:start position:0% +all possible ways i could draw the lines + + + align:start position:0% +all possible ways i could draw the lines +well then it might be useful to have a + + align:start position:0% +well then it might be useful to have a + + + align:start position:0% +well then it might be useful to have a +piece of software that could just + + align:start position:0% +piece of software that could just + + + align:start position:0% +piece of software that could just +randomly draw such a thing so in other + + align:start position:0% +randomly draw such a thing so in other + + + align:start position:0% +randomly draw such a thing so in other +words to draw something where the + + align:start position:0% +words to draw something where the + + + align:start position:0% +words to draw something where the +probability of any one partition + + align:start position:0% +probability of any one partition + + + align:start position:0% +probability of any one partition +is one over the number of partitions um + + align:start position:0% +is one over the number of partitions um + + + align:start position:0% +is one over the number of partitions um +this seems innocent in fact actually + + align:start position:0% +this seems innocent in fact actually + + + align:start position:0% +this seems innocent in fact actually +there's a number of papers that claim to + + align:start position:0% +there's a number of papers that claim to + + + align:start position:0% +there's a number of papers that claim to +do things like this + + align:start position:0% +do things like this + + + align:start position:0% +do things like this +but it turns out that it's a + + align:start position:0% +but it turns out that it's a + + + align:start position:0% +but it turns out that it's a +computationally uh + + align:start position:0% +computationally uh + + + align:start position:0% +computationally uh +difficult uh assuming that you believe + + align:start position:0% +difficult uh assuming that you believe + + + align:start position:0% +difficult uh assuming that you believe +that p doesn't equal np + + align:start position:0% +that p doesn't equal np + + + align:start position:0% +that p doesn't equal np +so i'll maybe leave some suggestive + + align:start position:0% +so i'll maybe leave some suggestive + + + align:start position:0% +so i'll maybe leave some suggestive +pictures uh in the slides and we can + + align:start position:0% +pictures uh in the slides and we can + + + align:start position:0% +pictures uh in the slides and we can +if you guys text me or during if we have + + align:start position:0% +if you guys text me or during if we have + + + align:start position:0% +if you guys text me or during if we have +a you know professor student chat i'm + + align:start position:0% +a you know professor student chat i'm + + + align:start position:0% +a you know professor student chat i'm +happy to sketch it out to you then + + align:start position:0% +happy to sketch it out to you then + + + align:start position:0% +happy to sketch it out to you then +um there's a very nice easy proof uh + + align:start position:0% +um there's a very nice easy proof uh + + + align:start position:0% +um there's a very nice easy proof uh +that reduces the hamiltonian cycle + + align:start position:0% +that reduces the hamiltonian cycle + + + align:start position:0% +that reduces the hamiltonian cycle +um and shows you that maybe you + + align:start position:0% +um and shows you that maybe you + + + align:start position:0% +um and shows you that maybe you +shouldn't trust these tools uh + + align:start position:0% +shouldn't trust these tools uh + + + align:start position:0% +shouldn't trust these tools uh +as much as they're argued about + + align:start position:0% +as much as they're argued about + + + align:start position:0% +as much as they're argued about +literally the supreme court a couple + + align:start position:0% +literally the supreme court a couple + + + align:start position:0% +literally the supreme court a couple +months ago + + align:start position:0% +months ago + + + align:start position:0% +months ago +by the way it was it was pretty fun like + + align:start position:0% +by the way it was it was pretty fun like + + + align:start position:0% +by the way it was it was pretty fun like +our uh expert report was referenced in + + align:start position:0% +our uh expert report was referenced in + + + align:start position:0% +our uh expert report was referenced in +the descent of the the case last summer + + align:start position:0% +the descent of the the case last summer + + + align:start position:0% +the descent of the the case last summer +um and when you read the discussion like + + align:start position:0% +um and when you read the discussion like + + + align:start position:0% +um and when you read the discussion like +you can see the judges trying to talk + + align:start position:0% +you can see the judges trying to talk + + + align:start position:0% +you can see the judges trying to talk +their way around complexity and + + align:start position:0% +their way around complexity and + + + align:start position:0% +their way around complexity and +um it's an interesting if somewhat dry + + align:start position:0% +um it's an interesting if somewhat dry + + + align:start position:0% +um it's an interesting if somewhat dry +uh read + + align:start position:0% +uh read + + + align:start position:0% +uh read +so in any event that's just the starting + + align:start position:0% +so in any event that's just the starting + + + align:start position:0% +so in any event that's just the starting +point for our research which says that + + align:start position:0% +point for our research which says that + + + align:start position:0% +point for our research which says that +of course these + + align:start position:0% +of course these + + + align:start position:0% +of course these +sampling problems are really hard and + + align:start position:0% +sampling problems are really hard and + + + align:start position:0% +sampling problems are really hard and +the question is what can you do like you + + align:start position:0% +the question is what can you do like you + + + align:start position:0% +the question is what can you do like you +throw the baby out with bath water or + + align:start position:0% +throw the baby out with bath water or + + + align:start position:0% +throw the baby out with bath water or +not + + align:start position:0% +not + + + align:start position:0% +not +um but the uh the real message here is + + align:start position:0% +um but the uh the real message here is + + + align:start position:0% +um but the uh the real message here is +of course the + + align:start position:0% +of course the + + + align:start position:0% +of course the +this course is unavoidable even in these + + align:start position:0% +this course is unavoidable even in these + + + align:start position:0% +this course is unavoidable even in these +extremely applied problems showing up in + + align:start position:0% +extremely applied problems showing up in + + + align:start position:0% +extremely applied problems showing up in +court cases or on your graphics card + + align:start position:0% +court cases or on your graphics card + + + align:start position:0% +court cases or on your graphics card +uh you're still complexity and + + align:start position:0% +uh you're still complexity and + + + align:start position:0% +uh you're still complexity and +algorithms and data structures + + align:start position:0% +algorithms and data structures + + + align:start position:0% +algorithms and data structures +are going to come back to play um so + + align:start position:0% +are going to come back to play um so + + + align:start position:0% +are going to come back to play um so +with that + + align:start position:0% +with that + + + align:start position:0% +with that +uh find our other two instructors up + + align:start position:0% +uh find our other two instructors up + + + align:start position:0% +uh find our other two instructors up +here for our final uh farewell + + align:start position:0% +here for our final uh farewell + + + align:start position:0% +here for our final uh farewell +suitably distance so algorithms are + + align:start position:0% +suitably distance so algorithms are + + + align:start position:0% +suitably distance so algorithms are +everywhere + + align:start position:0% +everywhere + + + align:start position:0% +everywhere +i hope you enjoyed this class it's been + + align:start position:0% +i hope you enjoyed this class it's been + + + align:start position:0% +i hope you enjoyed this class it's been +a lot of fun teaching you and having you + + align:start position:0% +a lot of fun teaching you and having you + + + align:start position:0% +a lot of fun teaching you and having you +as students + + align:start position:0% +as students + + + align:start position:0% +as students +even though you're not here physically + + align:start position:0% +even though you're not here physically + + + align:start position:0% +even though you're not here physically +in the room we still feel your presence + + align:start position:0% +in the room we still feel your presence + + + align:start position:0% +in the room we still feel your presence +and uh i look forward to seeing you all + + align:start position:0% +and uh i look forward to seeing you all + + + align:start position:0% +and uh i look forward to seeing you all +soon + + align:start position:0% +soon + + + align:start position:0% +soon +thanks for being a part of this fun + + align:start position:0% +thanks for being a part of this fun + + + align:start position:0% +thanks for being a part of this fun +thing i want to thank our to uh my + + align:start position:0% +thing i want to thank our to uh my + + + align:start position:0% +thing i want to thank our to uh my +co-two co-instructors for an awesome + + align:start position:0% +co-two co-instructors for an awesome + + + align:start position:0% +co-two co-instructors for an awesome +time this semester it's been a lot of + + align:start position:0% +time this semester it's been a lot of + + + align:start position:0% +time this semester it's been a lot of +fun teaching to you guys and + + align:start position:0% +fun teaching to you guys and + + + align:start position:0% +fun teaching to you guys and +thanks for uh spending 006 with us this + + align:start position:0% +thanks for uh spending 006 with us this + + + align:start position:0% +thanks for uh spending 006 with us this +term yeah thank you and hopefully we'll + + align:start position:0% +term yeah thank you and hopefully we'll + + + align:start position:0% +term yeah thank you and hopefully we'll +see you again soon + + align:start position:0% + + + + align:start position:0% + +bye + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/5a2Poe_N0sQ.txt b/5a2Poe_N0sQ.txt new file mode 100644 index 0000000000000000000000000000000000000000..add5fd4da12b1092187506f76d69408a7a0e6f26 --- /dev/null +++ b/5a2Poe_N0sQ.txt @@ -0,0 +1,12032 @@ +align:start position:0% + +okay for lecture + + align:start position:0% +okay for lecture + + + align:start position:0% +okay for lecture +30 uh which is you could say special + + align:start position:0% +30 uh which is you could say special + + + align:start position:0% +30 uh which is you could say special +cases of linear programming you could + + align:start position:0% +cases of linear programming you could + + + align:start position:0% +cases of linear programming you could +say special cases of integer programming + + align:start position:0% +say special cases of integer programming + + + align:start position:0% +say special cases of integer programming +but you got to say that word special + + align:start position:0% +but you got to say that word special + + + align:start position:0% +but you got to say that word special +because these are + + align:start position:0% +because these are + + + align:start position:0% +because these are +problems which fit where the answers the + + align:start position:0% +problems which fit where the answers the + + + align:start position:0% +problems which fit where the answers the +the the the the options are zero and + + align:start position:0% +the the the the options are zero and + + + align:start position:0% +the the the the options are zero and +one for the unknown X's so that in that + + align:start position:0% +one for the unknown X's so that in that + + + align:start position:0% +one for the unknown X's so that in that +way they're integer problems + + align:start position:0% +way they're integer problems + + + align:start position:0% +way they're integer problems +you a uh um we're looking at a zero or + + align:start position:0% +you a uh um we're looking at a zero or + + + align:start position:0% +you a uh um we're looking at a zero or +one marriages people are matched or + + align:start position:0% +one marriages people are matched or + + + align:start position:0% +one marriages people are matched or +they're not matched and usually integer + + align:start position:0% +they're not matched and usually integer + + + align:start position:0% +they're not matched and usually integer +programs are much harder than linear + + align:start position:0% + + + + align:start position:0% + +programs because uh the Simplex method + + align:start position:0% +programs because uh the Simplex method + + + align:start position:0% +programs because uh the Simplex method +for example for linear programs you you + + align:start position:0% +for example for linear programs you you + + + align:start position:0% +for example for linear programs you you +allowed all those fractions in between + + align:start position:0% +allowed all those fractions in between + + + align:start position:0% +allowed all those fractions in between +until you hit a corner and you didn't + + align:start position:0% +until you hit a corner and you didn't + + + align:start position:0% +until you hit a corner and you didn't +know whether that corner had integer + + align:start position:0% +know whether that corner had integer + + + align:start position:0% +know whether that corner had integer +values now it's true in the + + align:start position:0% +values now it's true in the + + + align:start position:0% +values now it's true in the +particular exam example I chose it + + align:start position:0% +particular exam example I chose it + + + align:start position:0% +particular exam example I chose it +turned out that the graduate student + + align:start position:0% +turned out that the graduate student + + + align:start position:0% +turned out that the graduate student +worked + + align:start position:0% +worked + + + align:start position:0% +worked +for 4 hours + + align:start position:0% +for 4 hours + + + align:start position:0% +for 4 hours +integer and the uh others worked for + + align:start position:0% +integer and the uh others worked for + + + align:start position:0% +integer and the uh others worked for +zero + + align:start position:0% +zero + + + align:start position:0% +zero +hours but uh the general linear program + + align:start position:0% +hours but uh the general linear program + + + align:start position:0% +hours but uh the general linear program +with ax equal B is not integer at all + + align:start position:0% +with ax equal B is not integer at all + + + align:start position:0% +with ax equal B is not integer at all +and we don't have to think about that + + align:start position:0% +and we don't have to think about that + + + align:start position:0% +and we don't have to think about that +which makes life much easier we just + + align:start position:0% +which makes life much easier we just + + + align:start position:0% +which makes life much easier we just +solve ax equal B if I add the constraint + + align:start position:0% +solve ax equal B if I add the constraint + + + align:start position:0% +solve ax equal B if I add the constraint +that the X's have to be integers that is + + align:start position:0% +that the X's have to be integers that is + + + align:start position:0% +that the X's have to be integers that is +a normally a very serious difficulty I + + align:start position:0% +a normally a very serious difficulty I + + + align:start position:0% +a normally a very serious difficulty I +get + + align:start position:0% + + + + align:start position:0% + +into + + align:start position:0% +into + + + align:start position:0% +into +exponential algorithms there aren't + + align:start position:0% +exponential algorithms there aren't + + + align:start position:0% +exponential algorithms there aren't +polinomial algorithms in fact the one of + + align:start position:0% +polinomial algorithms in fact the one of + + + align:start position:0% +polinomial algorithms in fact the one of +the million dooll problems + + align:start position:0% +the million dooll problems + + + align:start position:0% +the million dooll problems +uh + + align:start position:0% +uh + + + align:start position:0% +uh +offered uh proposed by the clay math + + align:start position:0% +offered uh proposed by the clay math + + + align:start position:0% +offered uh proposed by the clay math +Institute uh one of the seven is this + + align:start position:0% +Institute uh one of the seven is this + + + align:start position:0% +Institute uh one of the seven is this +problem uh P whether P equals + + align:start position:0% +problem uh P whether P equals + + + align:start position:0% +problem uh P whether P equals +NP so that P stands for polinomial and + + align:start position:0% +NP so that P stands for polinomial and + + + align:start position:0% +NP so that P stands for polinomial and +the n p stands for non-p polinomial the + + align:start position:0% +the n p stands for non-p polinomial the + + + align:start position:0% +the n p stands for non-p polinomial the +question is to prove that there is no + + align:start position:0% +question is to prove that there is no + + + align:start position:0% +question is to prove that there is no +algorithm of polinomial time for certain + + align:start position:0% +algorithm of polinomial time for certain + + + align:start position:0% +algorithm of polinomial time for certain +integer + + align:start position:0% +integer + + + align:start position:0% +integer +programs and that's an outstanding + + align:start position:0% +programs and that's an outstanding + + + align:start position:0% +programs and that's an outstanding +problem everybody thinks well I won't + + align:start position:0% +problem everybody thinks well I won't + + + align:start position:0% +problem everybody thinks well I won't +say everybody most people think that + + align:start position:0% +say everybody most people think that + + + align:start position:0% +say everybody most people think that +probably P doesn't equal NP that there + + align:start position:0% +probably P doesn't equal NP that there + + + align:start position:0% +probably P doesn't equal NP that there +are some polinomial Pro there are some + + align:start position:0% +are some polinomial Pro there are some + + + align:start position:0% +are some polinomial Pro there are some +there are + + align:start position:0% +there are + + + align:start position:0% +there are +some of these standard problems that + + align:start position:0% +some of these standard problems that + + + align:start position:0% +some of these standard problems that +can't be solved you can't there is + + align:start position:0% +can't be solved you can't there is + + + align:start position:0% +can't be solved you can't there is +nobody there is no algorithm of + + align:start position:0% +nobody there is no algorithm of + + + align:start position:0% +nobody there is no algorithm of +polinomial length polinomial running + + align:start position:0% +polinomial length polinomial running + + + align:start position:0% +polinomial length polinomial running +time that would do it but to to consider + + align:start position:0% +time that would do it but to to consider + + + align:start position:0% +time that would do it but to to consider +all possible algorithms and show that + + align:start position:0% +all possible algorithms and show that + + + align:start position:0% +all possible algorithms and show that +they all let you down is an unsolved + + align:start position:0% +they all let you down is an unsolved + + + align:start position:0% +they all let you down is an unsolved +problem so + + align:start position:0% +problem so + + + align:start position:0% +problem so +um but we do know so what do we know we + + align:start position:0% +um but we do know so what do we know we + + + align:start position:0% +um but we do know so what do we know we +have some problems like linear + + align:start position:0% +have some problems like linear + + + align:start position:0% +have some problems like linear +programming that we know are polinomial + + align:start position:0% +programming that we know are polinomial + + + align:start position:0% +programming that we know are polinomial +this one is + + align:start position:0% +this one is + + + align:start position:0% +this one is +polinomial we have a bunch of other + + align:start position:0% +polinomial we have a bunch of other + + + align:start position:0% +polinomial we have a bunch of other +problems that we know if we could solve + + align:start position:0% +problems that we know if we could solve + + + align:start position:0% +problems that we know if we could solve +one of them they they're equivalent you + + align:start position:0% +one of them they they're equivalent you + + + align:start position:0% +one of them they they're equivalent you +could say if there was an for one of + + align:start position:0% +could say if there was an for one of + + + align:start position:0% +could say if there was an for one of +them in polinomial time then all the + + align:start position:0% +them in polinomial time then all the + + + align:start position:0% +them in polinomial time then all the +whole lot we could solve so that's a + + align:start position:0% +whole lot we could solve so that's a + + + align:start position:0% +whole lot we could solve so that's a +whole bunch of problems that we believe + + align:start position:0% +whole bunch of problems that we believe + + + align:start position:0% +whole bunch of problems that we believe +can't be solved in polinomial time and + + align:start position:0% +can't be solved in polinomial time and + + + align:start position:0% +can't be solved in polinomial time and +the best we've been able to do is to is + + align:start position:0% +the best we've been able to do is to is + + + align:start position:0% +the best we've been able to do is to is +to get them in a in a group and say if + + align:start position:0% +to get them in a in a group and say if + + + align:start position:0% +to get them in a in a group and say if +one could do it they all could do it if + + align:start position:0% +one could do it they all could do it if + + + align:start position:0% +one could do it they all could do it if +one can't none of them can okay now I'm + + align:start position:0% +one can't none of them can okay now I'm + + + align:start position:0% +one can't none of them can okay now I'm +want to speak about these special + + align:start position:0% +want to speak about these special + + + align:start position:0% +want to speak about these special +problems that's the subject and here + + align:start position:0% +problems that's the subject and here + + + align:start position:0% +problems that's the subject and here +I've picked a coup Three Special + + align:start position:0% +I've picked a coup Three Special + + + align:start position:0% +I've picked a coup Three Special +problems + + align:start position:0% +problems + + + align:start position:0% +problems +one two and barely May a chance to + + align:start position:0% +one two and barely May a chance to + + + align:start position:0% +one two and barely May a chance to +mention number three uh so let me tell + + align:start position:0% +mention number three uh so let me tell + + + align:start position:0% +mention number three uh so let me tell +you the marriage + + align:start position:0% +you the marriage + + + align:start position:0% +you the marriage +problem first in + + align:start position:0% +problem first in + + + align:start position:0% +problem first in +words uh so the marriage + + align:start position:0% +words uh so the marriage + + + align:start position:0% +words uh so the marriage +problem you have uh bunch of shall I say + + align:start position:0% +problem you have uh bunch of shall I say + + + align:start position:0% +problem you have uh bunch of shall I say +girls this sounds a little quaint Right + + align:start position:0% +girls this sounds a little quaint Right + + + align:start position:0% +girls this sounds a little quaint Right +girls and + + align:start position:0% + + + + align:start position:0% + +boys uh + + align:start position:0% +boys uh + + + align:start position:0% +boys uh +G1 G2 + + align:start position:0% +G1 G2 + + + align:start position:0% +G1 G2 +G3 say four four and four boys I'll take + + align:start position:0% +G3 say four four and four boys I'll take + + + align:start position:0% +G3 say four four and four boys I'll take +the problem that is described uh I think + + align:start position:0% +the problem that is described uh I think + + + align:start position:0% +the problem that is described uh I think +it's + + align:start position:0% +it's + + + align:start position:0% +it's +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +page 622 of the book I + + align:start position:0% +page 622 of the book I + + + align:start position:0% +page 622 of the book I +think okay now so certain marriages + + align:start position:0% +think okay now so certain marriages + + + align:start position:0% +think okay now so certain marriages +certain + + align:start position:0% +certain + + + align:start position:0% +certain +matchings are okay others are + + align:start position:0% +matchings are okay others are + + + align:start position:0% +matchings are okay others are +not so + + align:start position:0% +not so + + + align:start position:0% +not so +suppose all those matchings are okay in + + align:start position:0% +suppose all those matchings are okay in + + + align:start position:0% +suppose all those matchings are okay in +words all four boys are acceptable for + + align:start position:0% +words all four boys are acceptable for + + + align:start position:0% +words all four boys are acceptable for +this girl so any any matching is + + align:start position:0% +this girl so any any matching is + + + align:start position:0% +this girl so any any matching is +possible but now let me look and see + + align:start position:0% +possible but now let me look and see + + + align:start position:0% +possible but now let me look and see +what the others were in this + + align:start position:0% +what the others were in this + + + align:start position:0% +what the others were in this +example uh girl two only boy four maybe + + align:start position:0% +example uh girl two only boy four maybe + + + align:start position:0% +example uh girl two only boy four maybe +I use some yellow chalk so girl two only + + align:start position:0% +I use some yellow chalk so girl two only + + + align:start position:0% +I use some yellow chalk so girl two only +boy + + align:start position:0% +boy + + + align:start position:0% +boy +four girl + + align:start position:0% +four girl + + + align:start position:0% +four girl +three two and + + align:start position:0% + + + + align:start position:0% + +four and girl four for + + align:start position:0% +four and girl four for + + + align:start position:0% +four and girl four for +only number + + align:start position:0% +only number + + + align:start position:0% +only number +two I'll make that a dash line not + + align:start position:0% +two I'll make that a dash line not + + + align:start position:0% +two I'll make that a dash line not +because it's different but just to just + + align:start position:0% +because it's different but just to just + + + align:start position:0% +because it's different but just to just +to + + align:start position:0% +to + + + align:start position:0% +to +uh so I of course I'd like to create a + + align:start position:0% +uh so I of course I'd like to create a + + + align:start position:0% +uh so I of course I'd like to create a +matrix that describes + + align:start position:0% + + + + align:start position:0% + +this this uh it's sort of a graph right + + align:start position:0% +this this uh it's sort of a graph right + + + align:start position:0% +this this uh it's sort of a graph right +this this is called actually the + + align:start position:0% +this this is called actually the + + + align:start position:0% +this this is called actually the +official name for this would be a + + align:start position:0% +official name for this would be a + + + align:start position:0% +official name for this would be a +bipartite graph so so these are nodes in + + align:start position:0% +bipartite graph so so these are nodes in + + + align:start position:0% +bipartite graph so so these are nodes in +the + + align:start position:0% + + + + align:start position:0% + +graph and the word bipartite means + + align:start position:0% +graph and the word bipartite means + + + align:start position:0% +graph and the word bipartite means +that's it's got two parts the girls and + + align:start position:0% +that's it's got two parts the girls and + + + align:start position:0% +that's it's got two parts the girls and +the boys and all edges go between the + + align:start position:0% +the boys and all edges go between the + + + align:start position:0% +the boys and all edges go between the +two parts never anyway that's bipartite + + align:start position:0% +two parts never anyway that's bipartite + + + align:start position:0% +two parts never anyway that's bipartite +graphs this is these everything I say + + align:start position:0% +graphs this is these everything I say + + + align:start position:0% +graphs this is these everything I say +today there's a host of + + align:start position:0% +today there's a host of + + + align:start position:0% +today there's a host of +people that are just have the neck of + + align:start position:0% +people that are just have the neck of + + + align:start position:0% +people that are just have the neck of +these combinatorial questions that um + + align:start position:0% +these combinatorial questions that um + + + align:start position:0% +these combinatorial questions that um +that it's become uh a very significant + + align:start position:0% +that it's become uh a very significant + + + align:start position:0% +that it's become uh a very significant +part of modern modern mathematics pure + + align:start position:0% +part of modern modern mathematics pure + + + align:start position:0% +part of modern modern mathematics pure +and + + align:start position:0% +and + + + align:start position:0% +and +applied okay so let me Express the graph + + align:start position:0% +applied okay so let me Express the graph + + + align:start position:0% +applied okay so let me Express the graph +this way the first row will + + align:start position:0% +this way the first row will + + + align:start position:0% +this way the first row will +tell + + align:start position:0% +tell + + + align:start position:0% +tell +the that the all four boys are allowed + + align:start position:0% +the that the all four boys are allowed + + + align:start position:0% +the that the all four boys are allowed +the second row will tell us that only + + align:start position:0% +the second row will tell us that only + + + align:start position:0% +the second row will tell us that only +boy one is allow boy four the second + + align:start position:0% +boy one is allow boy four the second + + + align:start position:0% +boy one is allow boy four the second +will tell us that two and four four are + + align:start position:0% +will tell us that two and four four are + + + align:start position:0% +will tell us that two and four four are +allowed and the third that only two is + + align:start position:0% +allowed and the third that only two is + + + align:start position:0% +allowed and the third that only two is +allowed that would be the Matrix that so + + align:start position:0% +allowed that would be the Matrix that so + + + align:start position:0% +allowed that would be the Matrix that so +so AIG J equals 1 AI J equals 1 if girl + + align:start position:0% +so AIG J equals 1 AI J equals 1 if girl + + + align:start position:0% +so AIG J equals 1 AI J equals 1 if girl +I and boy J are okay and otherwise + + align:start position:0% + + + + align:start position:0% + +zero + + align:start position:0% +zero + + + align:start position:0% +zero +right zero + + align:start position:0% + + + + align:start position:0% + +else if not okay okay no + + align:start position:0% +else if not okay okay no + + + align:start position:0% +else if not okay okay no +Edge and what's our job well a complete + + align:start position:0% +Edge and what's our job well a complete + + + align:start position:0% +Edge and what's our job well a complete +matching so let me introduce few of + + align:start position:0% +matching so let me introduce few of + + + align:start position:0% +matching so let me introduce few of +these words a complete matching would be + + align:start position:0% +these words a complete matching would be + + + align:start position:0% +these words a complete matching would be +get everybody o get everybody + + align:start position:0% + + + + align:start position:0% + +married and the marriage problem + + align:start position:0% +married and the marriage problem + + + align:start position:0% +married and the marriage problem +is when can that be done can it be done + + align:start position:0% +is when can that be done can it be done + + + align:start position:0% +is when can that be done can it be done +in this example and what's a necessary + + align:start position:0% +in this example and what's a necessary + + + align:start position:0% +in this example and what's a necessary +and sufficient condition for doing + + align:start position:0% +and sufficient condition for doing + + + align:start position:0% +and sufficient condition for doing +it okay so the the ma and and of course + + align:start position:0% +it okay so the the ma and and of course + + + align:start position:0% +it okay so the the ma and and of course +you'll want a after the last lecture + + align:start position:0% +you'll want a after the last lecture + + + align:start position:0% +you'll want a after the last lecture +you'll want a maximization problem + + align:start position:0% +you'll want a maximization problem + + + align:start position:0% +you'll want a maximization problem +really here so the maximization problem + + align:start position:0% +really here so the maximization problem + + + align:start position:0% +really here so the maximization problem +would be how many marriages can we get + + align:start position:0% +would be how many marriages can we get + + + align:start position:0% +would be how many marriages can we get +maximize the number of marriages a + + align:start position:0% +maximize the number of marriages a + + + align:start position:0% +maximize the number of marriages a +complete matching means all married our + + align:start position:0% +complete matching means all married our + + + align:start position:0% +complete matching means all married our +problem would be to our our if we can't + + align:start position:0% +problem would be to our our if we can't + + + align:start position:0% +problem would be to our our if we can't +our problem would be to maximize the + + align:start position:0% +our problem would be to maximize the + + + align:start position:0% +our problem would be to maximize the +number of + + align:start position:0% + + + + align:start position:0% + +matches so this is like a specific + + align:start position:0% +matches so this is like a specific + + + align:start position:0% +matches so this is like a specific +question can everybody get + + align:start position:0% +question can everybody get + + + align:start position:0% +question can everybody get +matched and then if not the optimization + + align:start position:0% +matched and then if not the optimization + + + align:start position:0% +matched and then if not the optimization +problem the maximum problem would be to + + align:start position:0% +problem the maximum problem would be to + + + align:start position:0% +problem the maximum problem would be to +maximize the number of matches and + + align:start position:0% +maximize the number of matches and + + + align:start position:0% +maximize the number of matches and +there's going to be some minimum problem + + align:start position:0% +there's going to be some minimum problem + + + align:start position:0% +there's going to be some minimum problem +and the max will match them in at uh + + align:start position:0% +and the max will match them in at uh + + + align:start position:0% +and the max will match them in at uh +Duality at at at the winners okay now + + align:start position:0% +Duality at at at the winners okay now + + + align:start position:0% +Duality at at at the winners okay now +for this specific I would like first to + + align:start position:0% +for this specific I would like first to + + + align:start position:0% +for this specific I would like first to +ask this question is a complete is a + + align:start position:0% +ask this question is a complete is a + + + align:start position:0% +ask this question is a complete is a +complete or when is a complete matching + + align:start position:0% + + + + align:start position:0% + +possible + + align:start position:0% +possible + + + align:start position:0% +possible +sorry uh let's see um oh good + + align:start position:0% +sorry uh let's see um oh good + + + align:start position:0% +sorry uh let's see um oh good +question because it certainly will have + + align:start position:0% +question because it certainly will have + + + align:start position:0% +question because it certainly will have +a matrix + + align:start position:0% +a matrix + + + align:start position:0% +a matrix +answer well of course the Matrix of all + + align:start position:0% +answer well of course the Matrix of all + + + align:start position:0% +answer well of course the Matrix of all +one + + align:start position:0% + + + + align:start position:0% + +would so that would be a case where + + align:start position:0% +would so that would be a case where + + + align:start position:0% +would so that would be a case where +everybody's willing to marry everybody + + align:start position:0% +everybody's willing to marry everybody + + + align:start position:0% +everybody's willing to marry everybody +and the rank is + + align:start position:0% +and the rank is + + + align:start position:0% +and the rank is +one was my first thought was well what + + align:start position:0% +one was my first thought was well what + + + align:start position:0% +one was my first thought was well what +about the identity Matrix well the + + align:start position:0% +about the identity Matrix well the + + + align:start position:0% +about the identity Matrix well the +identity Matrix of course that's a + + align:start position:0% +identity Matrix of course that's a + + + align:start position:0% +identity Matrix of course that's a +perfect we have a perfect matching girl + + align:start position:0% +perfect we have a perfect matching girl + + + align:start position:0% +perfect we have a perfect matching girl +one on Bo only I mean they're match + + align:start position:0% +one on Bo only I mean they're match + + + align:start position:0% +one on Bo only I mean they're match +their match their match their match + + align:start position:0% +their match their match their match + + + align:start position:0% +their match their match their match +great um yeah so somehow rank is + + align:start position:0% +great um yeah so somehow rank is + + + align:start position:0% +great um yeah so somehow rank is +somewhere hiding here + + align:start position:0% +somewhere hiding here + + + align:start position:0% +somewhere hiding here +uh what about this specific + + align:start position:0% +uh what about this specific + + + align:start position:0% +uh what about this specific +example could I do a complete matching + + align:start position:0% +example could I do a complete matching + + + align:start position:0% +example could I do a complete matching +and and if you tell me why not we + + align:start position:0% +and and if you tell me why not we + + + align:start position:0% +and and if you tell me why not we +probably have a guess at the general + + align:start position:0% +probably have a guess at the general + + + align:start position:0% +probably have a guess at the general +theorem why not the answer is no no and + + align:start position:0% +theorem why not the answer is no no and + + + align:start position:0% +theorem why not the answer is no no and +what's tell me the reason not all + + align:start position:0% +what's tell me the reason not all + + + align:start position:0% +what's tell me the reason not all +independent + + align:start position:0% +independent + + + align:start position:0% +independent +col well let's that's this question of + + align:start position:0% +col well let's that's this question of + + + align:start position:0% +col well let's that's this question of +rank uh + + align:start position:0% +rank uh + + + align:start position:0% +rank uh +I'll in these in this language here of + + align:start position:0% +I'll in these in this language here of + + + align:start position:0% +I'll in these in this language here of +of + + align:start position:0% +of + + + align:start position:0% +of +edges would be maybe the way I'm looking + + align:start position:0% +edges would be maybe the way I'm looking + + + align:start position:0% +edges would be maybe the way I'm looking +and the words I yeah logically girl two + + align:start position:0% +and the words I yeah logically girl two + + + align:start position:0% +and the words I yeah logically girl two +and boy four have you got to take them + + align:start position:0% +and boy four have you got to take them + + + align:start position:0% +and boy four have you got to take them +out then the next two roads one's gone + + align:start position:0% +out then the next two roads one's gone + + + align:start position:0% +out then the next two roads one's gone +and and you've got a competition for boy + + align:start position:0% +and and you've got a competition for boy + + + align:start position:0% +and and you've got a competition for boy +too at that point right okay so now can + + align:start position:0% +too at that point right okay so now can + + + align:start position:0% +too at that point right okay so now can +we express the that put that into a way + + align:start position:0% +we express the that put that into a way + + + align:start position:0% +we express the that put that into a way +that doesn't pick out girl two as like + + align:start position:0% +that doesn't pick out girl two as like + + + align:start position:0% +that doesn't pick out girl two as like +guilty or boy four of course I should + + align:start position:0% +guilty or boy four of course I should + + + align:start position:0% +guilty or boy four of course I should +say + + align:start position:0% + + + + align:start position:0% + +whatever + + align:start position:0% + + + + align:start position:0% + +yeah okay + + align:start position:0% +yeah okay + + + align:start position:0% +yeah okay +but uh + + align:start position:0% +but uh + + + align:start position:0% +but uh +I let let me let me start this sentence + + align:start position:0% +I let let me let me start this sentence + + + align:start position:0% +I let let me let me start this sentence +the problem is that girls tooth three + + align:start position:0% +the problem is that girls tooth three + + + align:start position:0% +the problem is that girls tooth three +and + + align:start position:0% + + + + align:start position:0% + +four say it again and louder two boys + + align:start position:0% +four say it again and louder two boys + + + align:start position:0% +four say it again and louder two boys +only like this only like two + + align:start position:0% +only like this only like two + + + align:start position:0% +only like this only like two +boys we got three girls + + align:start position:0% +boys we got three girls + + + align:start position:0% +boys we got three girls +there that only can + + align:start position:0% +there that only can + + + align:start position:0% +there that only can +match are only acceptable only the only + + align:start position:0% +match are only acceptable only the only + + + align:start position:0% +match are only acceptable only the only +only matches are with two boys so you + + align:start position:0% +only matches are with two boys so you + + + align:start position:0% +only matches are with two boys so you +can't do + + align:start position:0% +can't do + + + align:start position:0% +can't do +it there's something but but I I I'll + + align:start position:0% +it there's something but but I I I'll + + + align:start position:0% +it there's something but but I I I'll +stay with that language so my my my + + align:start position:0% +stay with that language so my my my + + + align:start position:0% +stay with that language so my my my +theorem will be complete matching as + + align:start position:0% +theorem will be complete matching as + + + align:start position:0% +theorem will be complete matching as +possible if and only + + align:start position:0% +possible if and only + + + align:start position:0% +possible if and only +if now how shall I express it + + align:start position:0% + + + + align:start position:0% + +every set why don't better right + + align:start position:0% +every set why don't better right + + + align:start position:0% +every set why don't better right +right-handed here of + + align:start position:0% +right-handed here of + + + align:start position:0% +right-handed here of +girls + + align:start position:0% +girls + + + align:start position:0% +girls +say say k + + align:start position:0% +say say k + + + align:start position:0% +say say k +girls or R + + align:start position:0% +girls or R + + + align:start position:0% +girls or R +girls every set of girls every subset of + + align:start position:0% +girls every set of girls every subset of + + + align:start position:0% +girls every set of girls every subset of +girls whatever I'm thinking you take + + align:start position:0% +girls whatever I'm thinking you take + + + align:start position:0% +girls whatever I'm thinking you take +take any group of girls say k of them K + + align:start position:0% +take any group of girls say k of them K + + + align:start position:0% +take any group of girls say k of them K +of + + align:start position:0% + + + + align:start position:0% + +them must + + align:start position:0% + + + + align:start position:0% + +what much match there must be at least K + + align:start position:0% +what much match there must be at least K + + + align:start position:0% +what much match there must be at least K +booys that's + + align:start position:0% +booys that's + + + align:start position:0% +booys that's +clearly + + align:start position:0% +clearly + + + align:start position:0% +clearly +necessary right if I have a set of K + + align:start position:0% +necessary right if I have a set of K + + + align:start position:0% +necessary right if I have a set of K +girls that among them like these three + + align:start position:0% +girls that among them like these three + + + align:start position:0% +girls that among them like these three +that among them only connect + + align:start position:0% +that among them only connect + + + align:start position:0% +that among them only connect +except two boys then I can't do it so + + align:start position:0% +except two boys then I can't do it so + + + align:start position:0% +except two boys then I can't do it so +I've got it it's like that Duality weak + + align:start position:0% +I've got it it's like that Duality weak + + + align:start position:0% +I've got it it's like that Duality weak +Duality that I had before in some way + + align:start position:0% +Duality that I had before in some way + + + align:start position:0% +Duality that I had before in some way +half of the theorem is going to be easy + + align:start position:0% +half of the theorem is going to be easy + + + align:start position:0% +half of the theorem is going to be easy +let me finish the statement every set of + + align:start position:0% +let me finish the statement every set of + + + align:start position:0% +let me finish the statement every set of +girls K of them + + align:start position:0% +girls K of them + + + align:start position:0% +girls K of them +likes together collectively + + align:start position:0% + + + + align:start position:0% + +collectively at + + align:start position:0% +collectively at + + + align:start position:0% +collectively at +least + + align:start position:0% +least + + + align:start position:0% +least +K + + align:start position:0% + + + + align:start position:0% + +boys certainly + + align:start position:0% +boys certainly + + + align:start position:0% +boys certainly +necessary not clear at all that + + align:start position:0% +necessary not clear at all that + + + align:start position:0% +necessary not clear at all that +it's sufficient that + + align:start position:0% +it's sufficient that + + + align:start position:0% +it's sufficient that +if this worked if every set of girls did + + align:start position:0% +if this worked if every set of girls did + + + align:start position:0% +if this worked if every set of girls did +like at least K boys but that's the + + align:start position:0% +like at least K boys but that's the + + + align:start position:0% +like at least K boys but that's the +theorem and that's that's the solution + + align:start position:0% +theorem and that's that's the solution + + + align:start position:0% +theorem and that's that's the solution +to the marriage problem that that that + + align:start position:0% +to the marriage problem that that that + + + align:start position:0% +to the marriage problem that that that +this condition is certainly necessary if + + align:start position:0% +this condition is certainly necessary if + + + align:start position:0% +this condition is certainly necessary if +I have a set of girls that don't like + + align:start position:0% +I have a set of girls that don't like + + + align:start position:0% +I have a set of girls that don't like +enough boys there's no way I could + + align:start position:0% +enough boys there's no way I could + + + align:start position:0% +enough boys there's no way I could +complete the + + align:start position:0% +complete the + + + align:start position:0% +complete the +matching + + align:start position:0% +matching + + + align:start position:0% +matching +other uh the boy well these matches + + align:start position:0% +other uh the boy well these matches + + + align:start position:0% +other uh the boy well these matches +are made in heaven so to speak uh + + align:start position:0% +are made in heaven so to speak uh + + + align:start position:0% +are made in heaven so to speak uh +they're + + align:start position:0% +they're + + + align:start position:0% +they're +yeah I I I could yeah I could put an + + align:start position:0% +yeah I I I could yeah I could put an + + + align:start position:0% +yeah I I I could yeah I could put an +equivalent statement I guess that might + + align:start position:0% +equivalent statement I guess that might + + + align:start position:0% +equivalent statement I guess that might +be look different but it hopefully it + + align:start position:0% +be look different but it hopefully it + + + align:start position:0% +be look different but it hopefully it +would tie up that if every set of K + + align:start position:0% +would tie up that if every set of K + + + align:start position:0% +would tie up that if every set of K +boys like collectively at least K girls + + align:start position:0% +boys like collectively at least K girls + + + align:start position:0% +boys like collectively at least K girls +then that would be enough yeah so I + + align:start position:0% +then that would be enough yeah so I + + + align:start position:0% +then that would be enough yeah so I +don't have to work both directions it's + + align:start position:0% +don't have to work both directions it's + + + align:start position:0% +don't have to work both directions it's +enough to put it only in this direction + + align:start position:0% +enough to put it only in this direction + + + align:start position:0% +enough to put it only in this direction +so so that's the theorem that that uh + + align:start position:0% +so so that's the theorem that that uh + + + align:start position:0% +so so that's the theorem that that uh +and we could create other examples + + align:start position:0% +and we could create other examples + + + align:start position:0% +and we could create other examples +here um of course if I fix this one by + + align:start position:0% +here um of course if I fix this one by + + + align:start position:0% +here um of course if I fix this one by +allowing by this this set of three girls + + align:start position:0% +allowing by this this set of three girls + + + align:start position:0% +allowing by this this set of three girls +by getting a third boy into the picture + + align:start position:0% +by getting a third boy into the picture + + + align:start position:0% +by getting a third boy into the picture +for those three girls then I won't have + + align:start position:0% +for those three girls then I won't have + + + align:start position:0% +for those three girls then I won't have +any trouble to complete a matching where + + align:start position:0% +any trouble to complete a matching where + + + align:start position:0% +any trouble to complete a matching where +shall I do it well I could connect girl + + align:start position:0% +shall I do it well I could connect girl + + + align:start position:0% +shall I do it well I could connect girl +two to somewhere else okay now a + + align:start position:0% +two to somewhere else okay now a + + + align:start position:0% +two to somewhere else okay now a +complete matching is certainly possible + + align:start position:0% +complete matching is certainly possible + + + align:start position:0% +complete matching is certainly possible +I just put a one in the position in the + + align:start position:0% +I just put a one in the position in the + + + align:start position:0% +I just put a one in the position in the +21 position I just put a one + + align:start position:0% +21 position I just put a one + + + align:start position:0% +21 position I just put a one +there by matching girl two and boy + + align:start position:0% +there by matching girl two and boy + + + align:start position:0% +there by matching girl two and boy +one and now um uh complete match a + + align:start position:0% +one and now um uh complete match a + + + align:start position:0% +one and now um uh complete match a +complete match so now what's the + + align:start position:0% +complete match so now what's the + + + align:start position:0% +complete match so now what's the +complete + + align:start position:0% +complete + + + align:start position:0% +complete +matching uh how well this little set of + + align:start position:0% +matching uh how well this little set of + + + align:start position:0% +matching uh how well this little set of +three + + align:start position:0% + + + + align:start position:0% + +troublemakers is like they only like the + + align:start position:0% +troublemakers is like they only like the + + + align:start position:0% +troublemakers is like they only like the +only three boys there so I had better on + + align:start position:0% +only three boys there so I had better on + + + align:start position:0% +only three boys there so I had better on +that said I that probably uh I know that + + align:start position:0% +that said I that probably uh I know that + + + align:start position:0% +that said I that probably uh I know that +they have got to match for those three + + align:start position:0% +they have got to match for those three + + + align:start position:0% +they have got to match for those three +boys and the theorem will say I could do + + align:start position:0% +boys and the theorem will say I could do + + + align:start position:0% +boys and the theorem will say I could do +it so how can I do it I guess well let's + + align:start position:0% +it so how can I do it I guess well let's + + + align:start position:0% +it so how can I do it I guess well let's +use this new Edge girl three could + + align:start position:0% +use this new Edge girl three could + + + align:start position:0% +use this new Edge girl three could +connect with that + + align:start position:0% +connect with that + + + align:start position:0% +connect with that +one no it can't no it can't + + align:start position:0% +one no it can't no it can't + + + align:start position:0% +one no it can't no it can't +three has to go three has to go with + + align:start position:0% +three has to go three has to go with + + + align:start position:0% +three has to go three has to go with +four in this + + align:start position:0% +four in this + + + align:start position:0% +four in this +case four has to go with two good yeah + + align:start position:0% +case four has to go with two good yeah + + + align:start position:0% +case four has to go with two good yeah +put it that that's better okay so I got + + align:start position:0% +put it that that's better okay so I got + + + align:start position:0% +put it that that's better okay so I got +a match and then of course one who + + align:start position:0% +a match and then of course one who + + + align:start position:0% +a match and then of course one who +helped us out here is happy with + + align:start position:0% +helped us out here is happy with + + + align:start position:0% +helped us out here is happy with +three so is that have I + + align:start position:0% +three so is that have I + + + align:start position:0% +three so is that have I +now have I done it right I don't know + + align:start position:0% +now have I done it right I don't know + + + align:start position:0% +now have I done it right I don't know +I've colored it well oh because I used + + align:start position:0% +I've colored it well oh because I used + + + align:start position:0% +I've colored it well oh because I used +yellow for before before the optimum was + + align:start position:0% +yellow for before before the optimum was + + + align:start position:0% +yellow for before before the optimum was +written Brad yeah yeah it's like right + + align:start position:0% +written Brad yeah yeah it's like right + + + align:start position:0% +written Brad yeah yeah it's like right +that's right okay so uh so I could go + + align:start position:0% +that's right okay so uh so I could go + + + align:start position:0% +that's right okay so uh so I could go +through the proof which is quite neat + + align:start position:0% +through the proof which is quite neat + + + align:start position:0% +through the proof which is quite neat +and + + align:start position:0% +and + + + align:start position:0% +and +pleasant that oh I can outline the proof + + align:start position:0% +pleasant that oh I can outline the proof + + + align:start position:0% +pleasant that oh I can outline the proof +for + + align:start position:0% +for + + + align:start position:0% +for +you can I outline the proof that this + + align:start position:0% +you can I outline the proof that this + + + align:start position:0% +you can I outline the proof that this +that if this condition is satisfied for + + align:start position:0% +that if this condition is satisfied for + + + align:start position:0% +that if this condition is satisfied for +every it has to be satisfied for every + + align:start position:0% +every it has to be satisfied for every + + + align:start position:0% +every it has to be satisfied for every +set of girls so notice to check whether + + align:start position:0% +set of girls so notice to check whether + + + align:start position:0% +set of girls so notice to check whether +it's satisfied we haven't got a good way + + align:start position:0% +it's satisfied we haven't got a good way + + + align:start position:0% +it's satisfied we haven't got a good way +to do that yet but but if it's satisfied + + align:start position:0% +to do that yet but but if it's satisfied + + + align:start position:0% +to do that yet but but if it's satisfied +for every set of girls then I could + + align:start position:0% +for every set of girls then I could + + + align:start position:0% +for every set of girls then I could +match them + + align:start position:0% +match them + + + align:start position:0% +match them +all uh can I + + align:start position:0% +all uh can I + + + align:start position:0% +all uh can I +just mentally think of two cases one + + align:start position:0% +just mentally think of two cases one + + + align:start position:0% +just mentally think of two cases one +case would be where every set of girls + + align:start position:0% +case would be where every set of girls + + + align:start position:0% +case would be where every set of girls +likes more than kboys like so this is + + align:start position:0% +likes more than kboys like so this is + + + align:start position:0% +likes more than kboys like so this is +the room to maneuver case how how do you + + align:start position:0% +the room to maneuver case how how do you + + + align:start position:0% +the room to maneuver case how how do you +propose that I deal with that case in + + align:start position:0% +propose that I deal with that case in + + + align:start position:0% +propose that I deal with that case in +the room to maneuver case where every + + align:start position:0% +the room to maneuver case where every + + + align:start position:0% +the room to maneuver case where every +set of K girls likes I'm going to prove + + align:start position:0% +set of K girls likes I'm going to prove + + + align:start position:0% +set of K girls likes I'm going to prove +this by IND ction on the number here + + align:start position:0% +this by IND ction on the number here + + + align:start position:0% +this by IND ction on the number here +okay so if every set of girls likes more + + align:start position:0% +okay so if every set of girls likes more + + + align:start position:0% +okay so if every set of girls likes more +than enough + + align:start position:0% +than enough + + + align:start position:0% +than enough +boys what shall I + + align:start position:0% +boys what shall I + + + align:start position:0% +boys what shall I +do well set for every set full set yeah + + align:start position:0% +do well set for every set full set yeah + + + align:start position:0% +do well set for every set full set yeah +for every set well that's true the full + + align:start position:0% +for every set well that's true the full + + + align:start position:0% +for every set well that's true the full +set the full end girls will like exactly + + align:start position:0% +set the full end girls will like exactly + + + align:start position:0% +set the full end girls will like exactly +and boys but all subsets I've got give + + align:start position:0% +and boys but all subsets I've got give + + + align:start position:0% +and boys but all subsets I've got give +suppose that happens what shall I do + + align:start position:0% +suppose that happens what shall I do + + + align:start position:0% +suppose that happens what shall I do +well I just take the first girl she can + + align:start position:0% +well I just take the first girl she can + + + align:start position:0% +well I just take the first girl she can +marry anybody who's accept cble and then + + align:start position:0% +marry anybody who's accept cble and then + + + align:start position:0% +marry anybody who's accept cble and then +I look at the smaller the remaining n + + align:start position:0% +I look at the smaller the remaining n + + + align:start position:0% +I look at the smaller the remaining n +minus one problem and what's happening + + align:start position:0% +minus one problem and what's happening + + + align:start position:0% +minus one problem and what's happening +there now every set of those girls well + + align:start position:0% +there now every set of those girls well + + + align:start position:0% +there now every set of those girls well +I've only used up one boy and I I said + + align:start position:0% +I've only used up one boy and I I said + + + align:start position:0% +I've only used up one boy and I I said +in this case that I had room to maneuver + + align:start position:0% +in this case that I had room to maneuver + + + align:start position:0% +in this case that I had room to maneuver +so I still am okay all right with that + + align:start position:0% +so I still am okay all right with that + + + align:start position:0% +so I still am okay all right with that +that's the easy + + align:start position:0% +that's the easy + + + align:start position:0% +that's the easy +one then the harder case is when there's + + align:start position:0% +one then the harder case is when there's + + + align:start position:0% +one then the harder case is when there's +some I'm giving this proof you without + + align:start position:0% +some I'm giving this proof you without + + + align:start position:0% +some I'm giving this proof you without +writing here so should I write that case + + align:start position:0% +writing here so should I write that case + + + align:start position:0% +writing here so should I write that case +one which I just dealt with was uh that + + align:start position:0% +one which I just dealt with was uh that + + + align:start position:0% +one which I just dealt with was uh that +for K less than n that uh + + align:start position:0% +for K less than n that uh + + + align:start position:0% +for K less than n that uh +uh + + align:start position:0% +uh + + + align:start position:0% +uh +every + + align:start position:0% +every + + + align:start position:0% +every +subset has subset has uh uh more room to + + align:start position:0% +subset has subset has uh uh more room to + + + align:start position:0% +subset has subset has uh uh more room to +maneuver an extra boy or more is is okay + + align:start position:0% +maneuver an extra boy or more is is okay + + + align:start position:0% +maneuver an extra boy or more is is okay +and and then we can just make an + + align:start position:0% +and and then we can just make an + + + align:start position:0% +and and then we can just make an +assignment get to a smaller problem + + align:start position:0% +assignment get to a smaller problem + + + align:start position:0% +assignment get to a smaller problem +we're okay now this the harder case is + + align:start position:0% +we're okay now this the harder case is + + + align:start position:0% +we're okay now this the harder case is +some set + + align:start position:0% +some set + + + align:start position:0% +some set +of K + + align:start position:0% +of K + + + align:start position:0% +of K +girls some for some K less than n likes + + align:start position:0% +girls some for some K less than n likes + + + align:start position:0% +girls some for some K less than n likes +only n boys only exactly and boys okay + + align:start position:0% +only n boys only exactly and boys okay + + + align:start position:0% +only n boys only exactly and boys okay +how do I deal with that case k + + align:start position:0% +how do I deal with that case k + + + align:start position:0% +how do I deal with that case k +boys how do I deal with that + + align:start position:0% + + + + align:start position:0% + +case and and and still + + align:start position:0% +case and and and still + + + align:start position:0% +case and and and still +all you know what I'm doing so I'm + + align:start position:0% +all you know what I'm doing so I'm + + + align:start position:0% +all you know what I'm doing so I'm +assuming this true so all sets it's not + + align:start position:0% +assuming this true so all sets it's not + + + align:start position:0% +assuming this true so all sets it's not +enough just to check any single set all + + align:start position:0% +enough just to check any single set all + + + align:start position:0% +enough just to check any single set all +sets like enough and some particular + + align:start position:0% +sets like enough and some particular + + + align:start position:0% +sets like enough and some particular +subset likes just barely enough now what + + align:start position:0% +subset likes just barely enough now what + + + align:start position:0% +subset likes just barely enough now what +shall I do okay well the claim is that + + align:start position:0% +shall I do okay well the claim is that + + + align:start position:0% +shall I do okay well the claim is that +those K girls I can match them to those + + align:start position:0% +those K girls I can match them to those + + + align:start position:0% +those K girls I can match them to those +K boys which I better do now why am I + + align:start position:0% +K boys which I better do now why am I + + + align:start position:0% +K boys which I better do now why am I +able to do + + align:start position:0% +able to do + + + align:start position:0% +able to do +that that's the induction step + + align:start position:0% +that that's the induction step + + + align:start position:0% +that that's the induction step +that's this is a smaller than n + + align:start position:0% +that's this is a smaller than n + + + align:start position:0% +that's this is a smaller than n +group and it's the hypothesis is + + align:start position:0% +group and it's the hypothesis is + + + align:start position:0% +group and it's the hypothesis is +satisfied so + + align:start position:0% +satisfied so + + + align:start position:0% +satisfied so +by so it's a smaller problem and I'm + + align:start position:0% +by so it's a smaller problem and I'm + + + align:start position:0% +by so it's a smaller problem and I'm +assuming that I've solved all smaller + + align:start position:0% +assuming that I've solved all smaller + + + align:start position:0% +assuming that I've solved all smaller +problems and I'm now coming to n the + + align:start position:0% +problems and I'm now coming to n the + + + align:start position:0% +problems and I'm now coming to n the +case of n boys girls and boys okay so so + + align:start position:0% +case of n boys girls and boys okay so so + + + align:start position:0% +case of n boys girls and boys okay so so +a match them + + align:start position:0% + + + + align:start position:0% + +off this was a smaller problem + + align:start position:0% +off this was a smaller problem + + + align:start position:0% +off this was a smaller problem +so already presumed solved and now I + + align:start position:0% +so already presumed solved and now I + + + align:start position:0% +so already presumed solved and now I +have + + align:start position:0% +have + + + align:start position:0% +have +to what do I have to do now I've got to + + align:start position:0% +to what do I have to do now I've got to + + + align:start position:0% +to what do I have to do now I've got to +I've got the rest the other n minus + + align:start position:0% +I've got the rest the other n minus + + + align:start position:0% +I've got the rest the other n minus +K other n minus K how do I deal with + + align:start position:0% + + + + align:start position:0% + +them well I guess if I want to use + + align:start position:0% +them well I guess if I want to use + + + align:start position:0% +them well I guess if I want to use +that's a smaller problem + + align:start position:0% +that's a smaller problem + + + align:start position:0% +that's a smaller problem +too but I then I would have to check + + align:start position:0% +too but I then I would have to check + + + align:start position:0% +too but I then I would have to check +that this condition + + align:start position:0% +that this condition + + + align:start position:0% +that this condition +but K of the boys are now + + align:start position:0% +but K of the boys are now + + + align:start position:0% +but K of the boys are now +used so I have to check the other n + + align:start position:0% +used so I have to check the other n + + + align:start position:0% +used so I have to check the other n +minus K I have to check this condition + + align:start position:0% +minus K I have to check this condition + + + align:start position:0% +minus K I have to check this condition +can I call this Hall's condition there + + align:start position:0% +can I call this Hall's condition there + + + align:start position:0% +can I call this Hall's condition there +was a a guy named Hall who Halls + + align:start position:0% +was a a guy named Hall who Halls + + + align:start position:0% +was a a guy named Hall who Halls +condition I have to + + align:start position:0% +condition I have to + + + align:start position:0% +condition I have to +check + + align:start position:0% +check + + + align:start position:0% +check +check + + align:start position:0% +check + + + align:start position:0% +check +Hall on the these remaining on these on + + align:start position:0% +Hall on the these remaining on these on + + + align:start position:0% +Hall on the these remaining on these on +the on the unmarried + + align:start position:0% +the on the unmarried + + + align:start position:0% +the on the unmarried +ones isn't that the same + + align:start position:0% + + + + align:start position:0% + +let's see sorry isn't that the same as + + align:start position:0% +let's see sorry isn't that the same as + + + align:start position:0% +let's see sorry isn't that the same as +your there + + align:start position:0% + + + + align:start position:0% + +call for these other guys yeah let's see + + align:start position:0% +call for these other guys yeah let's see + + + align:start position:0% +call for these other guys yeah let's see +the thing + + align:start position:0% +the thing + + + align:start position:0% +the thing +is we we can't match them off with boys + + align:start position:0% +is we we can't match them off with boys + + + align:start position:0% +is we we can't match them off with boys +that were used right by the first case + + align:start position:0% +that were used right by the first case + + + align:start position:0% +that were used right by the first case +so we have to be darn sure that these + + align:start position:0% +so we have to be darn sure that these + + + align:start position:0% +so we have to be darn sure that these +remaining girls + + align:start position:0% +remaining girls + + + align:start position:0% +remaining girls +like new boys I guess that's what I was + + align:start position:0% +like new boys I guess that's what I was + + + align:start position:0% +like new boys I guess that's what I was +thinking that you Tagg the K boys + + align:start position:0% +thinking that you Tagg the K boys + + + align:start position:0% +thinking that you Tagg the K boys +they're out of the picture they're out + + align:start position:0% +they're out of the picture they're out + + + align:start position:0% +they're out of the picture they're out +of the picture so the other nus K girls + + align:start position:0% +of the picture so the other nus K girls + + + align:start position:0% +of the picture so the other nus K girls +yes like this was K girls and K boys + + align:start position:0% +yes like this was K girls and K boys + + + align:start position:0% +yes like this was K girls and K boys +like the remaining nus K boys so you + + align:start position:0% +like the remaining nus K boys so you + + + align:start position:0% +like the remaining nus K boys so you +know but do I know that how do I know + + align:start position:0% +know but do I know that how do I know + + + align:start position:0% +know but do I know that how do I know +that those remaining + + align:start position:0% +that those remaining + + + align:start position:0% +that those remaining +girls that's the condition I mean in + + align:start position:0% +girls that's the condition I mean in + + + align:start position:0% +girls that's the condition I mean in +other words if you don't have that you + + align:start position:0% +other words if you don't have that you + + + align:start position:0% +other words if you don't have that you +can't you can't continue I can't + + align:start position:0% +can't you can't continue I can't + + + align:start position:0% +can't you can't continue I can't +continue but I have to check that I have + + align:start position:0% +continue but I have to check that I have + + + align:start position:0% +continue but I have to check that I have +that somehow from the original from + + align:start position:0% +that somehow from the original from + + + align:start position:0% +that somehow from the original from +knowing on the original big set I'm um + + align:start position:0% +knowing on the original big set I'm um + + + align:start position:0% +knowing on the original big set I'm um +see what I mean what what I have to + + align:start position:0% +see what I mean what what I have to + + + align:start position:0% +see what I mean what what I have to +worry about is hey maybe some of these + + align:start position:0% +worry about is hey maybe some of these + + + align:start position:0% +worry about is hey maybe some of these +remaining girls only liked those same K + + align:start position:0% + + + + align:start position:0% + +boys and there would be something + + align:start position:0% +boys and there would be something + + + align:start position:0% +boys and there would be something +well girls like boys and that would + + align:start position:0% +well girls like boys and that would + + + align:start position:0% +well girls like boys and that would +violate but did we assume that was the + + align:start position:0% +violate but did we assume that was the + + + align:start position:0% +violate but did we assume that was the +largest set of K girls no I haven't I + + align:start position:0% +largest set of K girls no I haven't I + + + align:start position:0% +largest set of K girls no I haven't I +haven't but but I if necessary I could + + align:start position:0% +haven't but but I if necessary I could + + + align:start position:0% +haven't but but I if necessary I could +have but I didn't yeah but I mean yeah + + align:start position:0% +have but I didn't yeah but I mean yeah + + + align:start position:0% +have but I didn't yeah but I mean yeah +we're we're right in the middle exactly + + align:start position:0% +we're we're right in the middle exactly + + + align:start position:0% +we're we're right in the middle exactly +cooking + + align:start position:0% +cooking + + + align:start position:0% +cooking +this that only + + align:start position:0% + + + + align:start position:0% + +already would have violated I mean + + align:start position:0% +already would have violated I mean + + + align:start position:0% +already would have violated I mean +there's you're you're in the I mean so + + align:start position:0% +there's you're you're in the I mean so + + + align:start position:0% +there's you're you're in the I mean so +basically vac + + align:start position:0% +basically vac + + + align:start position:0% +basically vac +for + + align:start position:0% +for + + + align:start position:0% +for +all that's right that's it that's it + + align:start position:0% +all that's right that's it that's it + + + align:start position:0% +all that's right that's it that's it +including this condition in has to hold + + align:start position:0% +including this condition in has to hold + + + align:start position:0% +including this condition in has to hold +for sets of girls which included these K + + align:start position:0% +for sets of girls which included these K + + + align:start position:0% +for sets of girls which included these K +and some of + + align:start position:0% +and some of + + + align:start position:0% +and some of +these and it's yeah then it becomes fun + + align:start position:0% +these and it's yeah then it becomes fun + + + align:start position:0% +these and it's yeah then it becomes fun +I won't like spoil everybody's fun here + + align:start position:0% +I won't like spoil everybody's fun here + + + align:start position:0% +I won't like spoil everybody's fun here +it's just beautiful that it works out + + align:start position:0% +it's just beautiful that it works out + + + align:start position:0% +it's just beautiful that it works out +that that if I if I look at a set of + + align:start position:0% +that that if I if I look at a set of + + + align:start position:0% +that that if I if I look at a set of +some of these remaining K and then I add + + align:start position:0% +some of these remaining K and then I add + + + align:start position:0% +some of these remaining K and then I add +in these original K and then I have then + + align:start position:0% +in these original K and then I have then + + + align:start position:0% +in these original K and then I have then +I look at the hypothesis on that and + + align:start position:0% +I look at the hypothesis on that and + + + align:start position:0% +I look at the hypothesis on that and +anyway it's + + align:start position:0% +anyway it's + + + align:start position:0% +anyway it's +beautiful it's beautiful I it's so I'll + + align:start position:0% +beautiful it's beautiful I it's so I'll + + + align:start position:0% +beautiful it's beautiful I it's so I'll +put it's check and and then we didn't + + align:start position:0% +put it's check and and then we didn't + + + align:start position:0% +put it's check and and then we didn't +maybe say all the words that need to be + + align:start position:0% +maybe say all the words that need to be + + + align:start position:0% +maybe say all the words that need to be +said but it's it's really nice it's + + align:start position:0% +said but it's it's really nice it's + + + align:start position:0% +said but it's it's really nice it's +really nice okay this is kind of off + + align:start position:0% +really nice okay this is kind of off + + + align:start position:0% +really nice okay this is kind of off +subject yes does it sort of relate like + + align:start position:0% +subject yes does it sort of relate like + + + align:start position:0% +subject yes does it sort of relate like +I'm looking at that 4x4 Matrix all right + + align:start position:0% +I'm looking at that 4x4 Matrix all right + + + align:start position:0% +I'm looking at that 4x4 Matrix all right +I'm ready to look back at that too think + + align:start position:0% +I'm ready to look back at that too think + + + align:start position:0% +I'm ready to look back at that too think +that the is non singular is that a + + align:start position:0% +that the is non singular is that a + + + align:start position:0% +that the is non singular is that a +factor for example if two of those rows + + align:start position:0% +factor for example if two of those rows + + + align:start position:0% +factor for example if two of those rows +of the Matrix had 0 1 0 Z yes there's no + + align:start position:0% +of the Matrix had 0 1 0 Z yes there's no + + + align:start position:0% +of the Matrix had 0 1 0 Z yes there's no +way you can satisfy the condition we + + align:start position:0% +way you can satisfy the condition we + + + align:start position:0% +way you can satisfy the condition we +just talking about that's + + align:start position:0% +just talking about that's + + + align:start position:0% +just talking about that's +true yeah and that's all they want right + + align:start position:0% +true yeah and that's all they want right + + + align:start position:0% +true yeah and that's all they want right +but I I don't + + align:start position:0% +but I I don't + + + align:start position:0% +but I I don't +totally yeah I don't I don't there isn't + + align:start position:0% +totally yeah I don't I don't there isn't + + + align:start position:0% +totally yeah I don't I don't there isn't +a perfect match between Singularity of + + align:start position:0% +a perfect match between Singularity of + + + align:start position:0% +a perfect match between Singularity of +the Matrix or or dependence of the rows + + align:start position:0% +the Matrix or or dependence of the rows + + + align:start position:0% +the Matrix or or dependence of the rows +and this and let me show you actually + + align:start position:0% +and this and let me show you actually + + + align:start position:0% +and this and let me show you actually +what comes in with this Matrix cuz it's + + align:start position:0% +what comes in with this Matrix cuz it's + + + align:start position:0% +what comes in with this Matrix cuz it's +quite fun uh imagine those ones are + + align:start position:0% +quite fun uh imagine those ones are + + + align:start position:0% +quite fun uh imagine those ones are +Rooks in a in a chess game or well let + + align:start position:0% +Rooks in a in a chess game or well let + + + align:start position:0% +Rooks in a in a chess game or well let +me here let me State the problem let me + + align:start position:0% +me here let me State the problem let me + + + align:start position:0% +me here let me State the problem let me +State the problem this way how many line + + align:start position:0% +State the problem this way how many line + + + align:start position:0% +State the problem this way how many line +can I go back to zero here my original + + align:start position:0% +can I go back to zero here my original + + + align:start position:0% +can I go back to zero here my original +one where it was trouble where I could + + align:start position:0% +one where it was trouble where I could + + + align:start position:0% +one where it was trouble where I could +only mat where I couldn't match all four + + align:start position:0% +only mat where I couldn't match all four + + + align:start position:0% +only mat where I couldn't match all four +then the question is how many could I + + align:start position:0% +then the question is how many could I + + + align:start position:0% +then the question is how many could I +match Ma so the maximum number of mat + + align:start position:0% +match Ma so the maximum number of mat + + + align:start position:0% +match Ma so the maximum number of mat +matching here here's the great theorem + + align:start position:0% +matching here here's the great theorem + + + align:start position:0% +matching here here's the great theorem +because maximum is going to equal a + + align:start position:0% +because maximum is going to equal a + + + align:start position:0% +because maximum is going to equal a +minimum in this thing is the minimum + + align:start position:0% +minimum in this thing is the minimum + + + align:start position:0% +minimum in this thing is the minimum +number of + + align:start position:0% +number of + + + align:start position:0% +number of +lines that cover the ones + + align:start position:0% +lines that cover the ones + + + align:start position:0% +lines that cover the ones +to and I'll put this in yellow to + + align:start position:0% + + + + align:start position:0% + +cover all the ones in the Matrix now + + align:start position:0% +cover all the ones in the Matrix now + + + align:start position:0% +cover all the ones in the Matrix now +what do I mean by that I mean we think + + align:start position:0% +what do I mean by that I mean we think + + + align:start position:0% +what do I mean by that I mean we think +how many do you think was the maximum + + align:start position:0% +how many do you think was the maximum + + + align:start position:0% +how many do you think was the maximum +number number of marriages in this + + align:start position:0% +number number of marriages in this + + + align:start position:0% +number number of marriages in this +original sorry that I've screwed up the + + align:start position:0% +original sorry that I've screwed up the + + + align:start position:0% +original sorry that I've screwed up the +picture you remember the original with + + align:start position:0% +picture you remember the original with + + + align:start position:0% +picture you remember the original with +that Matrix how many how many could we + + align:start position:0% +that Matrix how many how many could we + + + align:start position:0% +that Matrix how many how many could we +marry off three three right so I believe + + align:start position:0% +marry off three three right so I believe + + + align:start position:0% +marry off three three right so I believe +that I can + + align:start position:0% +that I can + + + align:start position:0% +that I can +cover all the ones with three + + align:start position:0% +cover all the ones with three + + + align:start position:0% +cover all the ones with three +lines lines are horizontals or verticals + + align:start position:0% +lines lines are horizontals or verticals + + + align:start position:0% +lines lines are horizontals or verticals +so that's where there's a Twist somehow + + align:start position:0% +so that's where there's a Twist somehow + + + align:start position:0% +so that's where there's a Twist somehow +both boys and girls are in this picture + + align:start position:0% +both boys and girls are in this picture + + + align:start position:0% +both boys and girls are in this picture +so how could I cover all those + + align:start position:0% +so how could I cover all those + + + align:start position:0% +so how could I cover all those +ones + + align:start position:0% + + + + align:start position:0% + +wouldn't be hard right first + + align:start position:0% +wouldn't be hard right first + + + align:start position:0% +wouldn't be hard right first +row and what column second and fourth + + align:start position:0% +row and what column second and fourth + + + align:start position:0% +row and what column second and fourth +column + + align:start position:0% +column + + + align:start position:0% +column +right and I bet you somehow that tells + + align:start position:0% +right and I bet you somehow that tells + + + align:start position:0% +right and I bet you somehow that tells +me who's making + + align:start position:0% +me who's making + + + align:start position:0% +me who's making +trouble or something or who isn't or + + align:start position:0% +trouble or something or who isn't or + + + align:start position:0% +trouble or something or who isn't or +whatever yeah maybe the oh yeah the + + align:start position:0% +whatever yeah maybe the oh yeah the + + + align:start position:0% +whatever yeah maybe the oh yeah the +zeros tell me who's making TR of course + + align:start position:0% +zeros tell me who's making TR of course + + + align:start position:0% +zeros tell me who's making TR of course +trouble's coming from zeros so where are + + align:start position:0% +trouble's coming from zeros so where are + + + align:start position:0% +trouble's coming from zeros so where are +the + + align:start position:0% +the + + + align:start position:0% +the +zeros the zeros are in Girls 2 three and + + align:start position:0% +zeros the zeros are in Girls 2 three and + + + align:start position:0% +zeros the zeros are in Girls 2 three and +four + + align:start position:0% +four + + + align:start position:0% +four +and boys one and + + align:start position:0% +and boys one and + + + align:start position:0% +and boys one and +three and what was the problem + + align:start position:0% +three and what was the problem + + + align:start position:0% +three and what was the problem +there I had three girls and there's two + + align:start position:0% +there I had three girls and there's two + + + align:start position:0% +there I had three girls and there's two +boys they won't don't + + align:start position:0% +boys they won't don't + + + align:start position:0% +boys they won't don't +marry and yeah so the zeros I + + align:start position:0% + + + + align:start position:0% + +have yeah you you see it okay so yeah + + align:start position:0% +have yeah you you see it okay so yeah + + + align:start position:0% +have yeah you you see it okay so yeah +some so somehow that's the if I have a + + align:start position:0% +some so somehow that's the if I have a + + + align:start position:0% +some so somehow that's the if I have a +so there's now the general problem if I + + align:start position:0% +so there's now the general problem if I + + + align:start position:0% +so there's now the general problem if I +have a matrix of ones and zeros + + align:start position:0% +have a matrix of ones and zeros + + + align:start position:0% +have a matrix of ones and zeros +I can + + align:start position:0% +I can + + + align:start position:0% +I can +ask how many lines it takes to cover + + align:start position:0% +ask how many lines it takes to cover + + + align:start position:0% +ask how many lines it takes to cover +them shall we create I've never done + + align:start position:0% +them shall we create I've never done + + + align:start position:0% +them shall we create I've never done +this but should we just have another + + align:start position:0% +this but should we just have another + + + align:start position:0% +this but should we just have another +example up here of a bigger Matrix can I + + align:start position:0% +example up here of a bigger Matrix can I + + + align:start position:0% +example up here of a bigger Matrix can I +I'll just put in some ones and zeros at + + align:start position:0% + + + + align:start position:0% + +random sorry I'm just doing this totally + + align:start position:0% +random sorry I'm just doing this totally + + + align:start position:0% +random sorry I'm just doing this totally +at random without a without figur out + + align:start position:0% +at random without a without figur out + + + align:start position:0% +at random without a without figur out +ahead of time how many lines would cover + + align:start position:0% +ahead of time how many lines would cover + + + align:start position:0% +ahead of time how many lines would cover +them all right I don't know do you you + + align:start position:0% +them all right I don't know do you you + + + align:start position:0% +them all right I don't know do you you +think we could marry these get a perfect + + align:start position:0% +think we could marry these get a perfect + + + align:start position:0% +think we could marry these get a perfect +matching out of + + align:start position:0% + + + + align:start position:0% + +that + + align:start position:0% +that + + + align:start position:0% +that +well I guess it's stupid for me to have + + align:start position:0% +well I guess it's stupid for me to have + + + align:start position:0% +well I guess it's stupid for me to have +started here because this 5x5 problem is + + align:start position:0% +started here because this 5x5 problem is + + + align:start position:0% +started here because this 5x5 problem is +not probably solvable in an instant time + + align:start position:0% +not probably solvable in an instant time + + + align:start position:0% +not probably solvable in an instant time +uh or could I cover it with less than + + align:start position:0% +uh or could I cover it with less than + + + align:start position:0% +uh or could I cover it with less than +four lines Well everybody's looking + + align:start position:0% +four lines Well everybody's looking + + + align:start position:0% +four lines Well everybody's looking +uh I bet none of us I bet got at least + + align:start position:0% +uh I bet none of us I bet got at least + + + align:start position:0% +uh I bet none of us I bet got at least +four horizontal lines + + align:start position:0% +four horizontal lines + + + align:start position:0% +four horizontal lines +right say I need at least four and + + align:start position:0% +right say I need at least four and + + + align:start position:0% +right say I need at least four and +probably I need five do I need five + + align:start position:0% +probably I need five do I need five + + + align:start position:0% +probably I need five do I need five +lines to cover that yeah maybe even six + + align:start position:0% +lines to cover that yeah maybe even six + + + align:start position:0% +lines to cover that yeah maybe even six +oh don't W take me six I mean even I can + + align:start position:0% +oh don't W take me six I mean even I can + + + align:start position:0% +oh don't W take me six I mean even I can +do it with five right yes right and that + + align:start position:0% +do it with five right yes right and that + + + align:start position:0% +do it with five right yes right and that +would mean that I could find a matching + + align:start position:0% +would mean that I could find a matching + + + align:start position:0% +would mean that I could find a matching +let's look for a matching hey there + + align:start position:0% +let's look for a matching hey there + + + align:start position:0% +let's look for a matching hey there +might be one of course what will a + + align:start position:0% +might be one of course what will a + + + align:start position:0% +might be one of course what will a +matching be a matching will be a + + align:start position:0% +matching be a matching will be a + + + align:start position:0% +matching be a matching will be a +marriage a set of marriages and that + + align:start position:0% +marriage a set of marriages and that + + + align:start position:0% +marriage a set of marriages and that +means that the ones have to come from + + align:start position:0% +means that the ones have to come from + + + align:start position:0% +means that the ones have to come from +different rows and columns CU each + + align:start position:0% +different rows and columns CU each + + + align:start position:0% +different rows and columns CU each +marriage is like unique so maybe suppose + + align:start position:0% +marriage is like unique so maybe suppose + + + align:start position:0% +marriage is like unique so maybe suppose +I yeah let me try to marry them marry + + align:start position:0% +I yeah let me try to marry them marry + + + align:start position:0% +I yeah let me try to marry them marry +them marry them oops better not let's + + align:start position:0% + + + + align:start position:0% + +see move the top one yes move that way + + align:start position:0% +see move the top one yes move that way + + + align:start position:0% +see move the top one yes move that way +over + + align:start position:0% +over + + + align:start position:0% +over +here then this is okay and all right + + align:start position:0% +here then this is okay and all right + + + align:start position:0% +here then this is okay and all right +yeah so there I + + align:start position:0% +yeah so there I + + + align:start position:0% +yeah so there I +see that uh I can marry all + + align:start position:0% +see that uh I can marry all + + + align:start position:0% +see that uh I can marry all +five and I believe that tells me it + + align:start position:0% +five and I believe that tells me it + + + align:start position:0% +five and I believe that tells me it +takes me five lines now somebody tell me + + align:start position:0% +takes me five lines now somebody tell me + + + align:start position:0% +takes me five lines now somebody tell me +the reasoning there how do I now know + + align:start position:0% +the reasoning there how do I now know + + + align:start position:0% +the reasoning there how do I now know +that I cannot cover + + align:start position:0% +that I cannot cover + + + align:start position:0% +that I cannot cover +those all the + + align:start position:0% +those all the + + + align:start position:0% +those all the +ones with less than five lines how do I + + align:start position:0% +ones with less than five lines how do I + + + align:start position:0% +ones with less than five lines how do I +now know that don't tell don't say it + + align:start position:0% +now know that don't tell don't say it + + + align:start position:0% +now know that don't tell don't say it +for a minute how do I now know so the + + align:start position:0% +for a minute how do I now know so the + + + align:start position:0% +for a minute how do I now know so the +the answer I claim was five + + align:start position:0% +the answer I claim was five + + + align:start position:0% +the answer I claim was five +I could get five matches and I showed + + align:start position:0% +I could get five matches and I showed + + + align:start position:0% +I could get five matches and I showed +what they were and I believe that the + + align:start position:0% +what they were and I believe that the + + + align:start position:0% +what they were and I believe that the +minimum number of lines so this is like + + align:start position:0% +minimum number of lines so this is like + + + align:start position:0% +minimum number of lines so this is like +weak Duality again the minimum is five I + + align:start position:0% +weak Duality again the minimum is five I + + + align:start position:0% +weak Duality again the minimum is five I +can't do it with less how do how do you + + align:start position:0% +can't do it with less how do how do you + + + align:start position:0% +can't do it with less how do how do you +see that I cannot cover those with five + + align:start position:0% +see that I cannot cover those with five + + + align:start position:0% +see that I cannot cover those with five +lines + + align:start position:0% + + + + align:start position:0% + +okay right that's right my line will + + align:start position:0% +okay right that's right my line will + + + align:start position:0% +okay right that's right my line will +have to my lines have to cover all five + + align:start position:0% +have to my lines have to cover all five + + + align:start position:0% +have to my lines have to cover all five +of those those circled ones I don't even + + align:start position:0% +of those those circled ones I don't even + + + align:start position:0% +of those those circled ones I don't even +care about I mean just to cover those + + align:start position:0% +care about I mean just to cover those + + + align:start position:0% +care about I mean just to cover those +five circled ones is going to take me + + align:start position:0% +five circled ones is going to take me + + + align:start position:0% +five circled ones is going to take me +five + + align:start position:0% +five + + + align:start position:0% +five +lines right so that's why that's the + + align:start position:0% +lines right so that's why that's the + + + align:start position:0% +lines right so that's why that's the +weak Duality that the number of matches + + align:start position:0% +weak Duality that the number of matches + + + align:start position:0% +weak Duality that the number of matches +is always less or + + align:start position:0% +is always less or + + + align:start position:0% +is always less or +equal the number of lines because + + align:start position:0% +equal the number of lines because + + + align:start position:0% +equal the number of lines because +anytime I've got a match I've got some + + align:start position:0% +anytime I've got a match I've got some + + + align:start position:0% +anytime I've got a match I've got some +ones that I need that many lines to + + align:start position:0% +ones that I need that many lines to + + + align:start position:0% +ones that I need that many lines to +cover because a line can't cover two in + + align:start position:0% +cover because a line can't cover two in + + + align:start position:0% +cover because a line can't cover two in +a match right a line no line could cover + + align:start position:0% +a match right a line no line could cover + + + align:start position:0% +a match right a line no line could cover +two of these at once a line could only + + align:start position:0% +two of these at once a line could only + + + align:start position:0% +two of these at once a line could only +cover one marriage and and maybe some + + align:start position:0% +cover one marriage and and maybe some + + + align:start position:0% +cover one marriage and and maybe some +extra stuff but it's going to take me + + align:start position:0% +extra stuff but it's going to take me + + + align:start position:0% +extra stuff but it's going to take me +five lines to cover five matches you see + + align:start position:0% +five lines to cover five matches you see + + + align:start position:0% +five lines to cover five matches you see +that weak Duality then has an easy + + align:start position:0% +that weak Duality then has an easy + + + align:start position:0% +that weak Duality then has an easy +argument but the equation the fact that + + align:start position:0% +argument but the equation the fact that + + + align:start position:0% +argument but the equation the fact that +the number of so I made it I made let's + + align:start position:0% +the number of so I made it I made let's + + + align:start position:0% +the number of so I made it I made let's +see let me let me can I change this + + align:start position:0% +see let me let me can I change this + + + align:start position:0% +see let me let me can I change this +problem by changing some of these to + + align:start position:0% +problem by changing some of these to + + + align:start position:0% +problem by changing some of these to +zeros does that now does that now + + align:start position:0% +zeros does that now does that now + + + align:start position:0% +zeros does that now does that now +prevent event five + + align:start position:0% +prevent event five + + + align:start position:0% +prevent event five +matches row fourth row okay let me make + + align:start position:0% +matches row fourth row okay let me make + + + align:start position:0% +matches row fourth row okay let me make +that a zero + + align:start position:0% +that a zero + + + align:start position:0% +that a zero +also all right no + + align:start position:0% +also all right no + + + align:start position:0% +also all right no +problem and the thir one goes the way to + + align:start position:0% +problem and the thir one goes the way to + + + align:start position:0% +problem and the thir one goes the way to +the right and the first one so what else + + align:start position:0% +the right and the first one so what else + + + align:start position:0% +the right and the first one so what else +do you want me to turn into a zero th + + align:start position:0% +do you want me to turn into a zero th + + + align:start position:0% +do you want me to turn into a zero th +this one yeah so if I make I make that a + + align:start position:0% +this one yeah so if I make I make that a + + + align:start position:0% +this one yeah so if I make I make that a +zero that's not a problem because + + align:start position:0% +zero that's not a problem because + + + align:start position:0% +zero that's not a problem because +the + + align:start position:0% +the + + + align:start position:0% +the +right so tell me what to make a zero + + align:start position:0% +right so tell me what to make a zero + + + align:start position:0% +right so tell me what to make a zero +that last that a zero oh if I put a zero + + align:start position:0% +that last that a zero oh if I put a zero + + + align:start position:0% +that last that a zero oh if I put a zero +there yeah but anybody can do that uh I + + align:start position:0% +there yeah but anybody can do that uh I + + + align:start position:0% +there yeah but anybody can do that uh I +want to put one somewhere else well all + + align:start position:0% +want to put one somewhere else well all + + + align:start position:0% +want to put one somewhere else well all +right I'll do one and then you'll tell + + align:start position:0% +right I'll do one and then you'll tell + + + align:start position:0% +right I'll do one and then you'll tell +me that that's not enough right that's + + align:start position:0% +me that that's not enough right that's + + + align:start position:0% +me that that's not enough right that's +definitely not enough definitely all + + align:start position:0% +definitely not enough definitely all + + + align:start position:0% +definitely not enough definitely all +right all right so you you say that's + + align:start position:0% +right all right so you you say that's + + + align:start position:0% +right all right so you you say that's +not + + align:start position:0% + + + + align:start position:0% + +enough it is enough yeah I think so it's + + align:start position:0% +enough it is enough yeah I think so it's + + + align:start position:0% +enough it is enough yeah I think so it's +getting there I'm getting there I'm I'm + + align:start position:0% +getting there I'm getting there I'm I'm + + + align:start position:0% +getting there I'm getting there I'm I'm +removing uh remember the bottom row yeah + + align:start position:0% +removing uh remember the bottom row yeah + + + align:start position:0% +removing uh remember the bottom row yeah +this so this + + align:start position:0% +this so this + + + align:start position:0% +this so this +right okay is that is a match possible + + align:start position:0% +right okay is that is a match possible + + + align:start position:0% +right okay is that is a match possible +there yes still one over the way to the + + align:start position:0% +there yes still one over the way to the + + + align:start position:0% +there yes still one over the way to the +right it's you still got a way to match + + align:start position:0% +right it's you still got a way to match + + + align:start position:0% +right it's you still got a way to match +those all right I'll take another one + + align:start position:0% +those all right I'll take another one + + + align:start position:0% +those all right I'll take another one +away + + align:start position:0% +away + + + align:start position:0% +away +uh well which I'll take one of these + + align:start position:0% +uh well which I'll take one of these + + + align:start position:0% +uh well which I'll take one of these +away yeah like that one no no no that + + align:start position:0% +away yeah like that one no no no that + + + align:start position:0% +away yeah like that one no no no that +didn't hurt like that one the first or + + align:start position:0% +didn't hurt like that one the first or + + + align:start position:0% +didn't hurt like that one the first or +the all right now we've got it okay now + + align:start position:0% +the all right now we've got it okay now + + + align:start position:0% +the all right now we've got it okay now +we believe that only the four the the we + + align:start position:0% +we believe that only the four the the we + + + align:start position:0% +we believe that only the four the the we +can only marry off four + + align:start position:0% +can only marry off four + + + align:start position:0% +can only marry off four +right but now how do we prove it because + + align:start position:0% +right but now how do we prove it because + + + align:start position:0% +right but now how do we prove it because +because you got to find four lines that + + align:start position:0% +because you got to find four lines that + + + align:start position:0% +because you got to find four lines that +cover + + align:start position:0% +cover + + + align:start position:0% +cover +everybody and that would + + align:start position:0% +everybody and that would + + + align:start position:0% +everybody and that would +say now what are four lines first two + + align:start position:0% +say now what are four lines first two + + + align:start position:0% +say now what are four lines first two +columns yeah just let me ask this + + align:start position:0% +columns yeah just let me ask this + + + align:start position:0% +columns yeah just let me ask this +question well no I won't but so if I + + align:start position:0% +question well no I won't but so if I + + + align:start position:0% +question well no I won't but so if I +find four lines that cover everybody + + align:start position:0% +find four lines that cover everybody + + + align:start position:0% +find four lines that cover everybody +then there could only be four matches + + align:start position:0% +then there could only be four matches + + + align:start position:0% +then there could only be four matches +cuz if there were five matches I could + + align:start position:0% +cuz if there were five matches I could + + + align:start position:0% +cuz if there were five matches I could +not cover all five all right now you now + + align:start position:0% +not cover all five all right now you now + + + align:start position:0% +not cover all five all right now you now +I'm ready to listen what + + align:start position:0% +I'm ready to listen what + + + align:start position:0% +I'm ready to listen what +for sorry two columns first two + + align:start position:0% +for sorry two columns first two + + + align:start position:0% +for sorry two columns first two +columns and then two + + align:start position:0% + + + + align:start position:0% + +rows okay and that left me a matrix of + + align:start position:0% +rows okay and that left me a matrix of + + + align:start position:0% +rows okay and that left me a matrix of +zeros a submatrix of zeros which should + + align:start position:0% +zeros a submatrix of zeros which should + + + align:start position:0% +zeros a submatrix of zeros which should +should tell me that trouble where the + + align:start position:0% +should tell me that trouble where the + + + align:start position:0% +should tell me that trouble where the +trouble is this this Matrix of zeros + + align:start position:0% +trouble is this this Matrix of zeros + + + align:start position:0% +trouble is this this Matrix of zeros +tells me that girls girls one 2 and four + + align:start position:0% +tells me that girls girls one 2 and four + + + align:start position:0% +tells me that girls girls one 2 and four +won't uh don't obviously tells me that + + align:start position:0% +won't uh don't obviously tells me that + + + align:start position:0% +won't uh don't obviously tells me that +boys three four and five are no good are + + align:start position:0% +boys three four and five are no good are + + + align:start position:0% +boys three four and five are no good are +not acceptable and + + align:start position:0% +not acceptable and + + + align:start position:0% +not acceptable and +therefore uh so the only boys that are + + align:start position:0% +therefore uh so the only boys that are + + + align:start position:0% +therefore uh so the only boys that are +acceptable for I have three girls and + + align:start position:0% +acceptable for I have three girls and + + + align:start position:0% +acceptable for I have three girls and +the only boys that are acceptable are + + align:start position:0% +the only boys that are acceptable are + + + align:start position:0% +the only boys that are acceptable are +the remaining one and two yeah which + + align:start position:0% + + + + align:start position:0% + +is was this one two + + align:start position:0% +is was this one two + + + align:start position:0% +is was this one two +five girls + + align:start position:0% +five girls + + + align:start position:0% +five girls +one let's + + align:start position:0% + + + + align:start position:0% + +see I thought these zeros and these + + align:start position:0% +see I thought these zeros and these + + + align:start position:0% +see I thought these zeros and these +zeros and these zeros refer to oh yeah + + align:start position:0% +zeros and these zeros refer to oh yeah + + + align:start position:0% +zeros and these zeros refer to oh yeah +refers to girls 125 right right refers + + align:start position:0% +refers to girls 125 right right refers + + + align:start position:0% +refers to girls 125 right right refers +to girls 125 and they will + + align:start position:0% + + + + align:start position:0% + +not match boys 345 they only match boys + + align:start position:0% +not match boys 345 they only match boys + + + align:start position:0% +not match boys 345 they only match boys +one two and here I have a set of three + + align:start position:0% +one two and here I have a set of three + + + align:start position:0% +one two and here I have a set of three +girls and only two boys one two and five + + align:start position:0% +girls and only two boys one two and five + + + align:start position:0% +girls and only two boys one two and five +the only two boys are these two + + align:start position:0% +the only two boys are these two + + + align:start position:0% +the only two boys are these two +boys yeah Haven you saw + + align:start position:0% +boys yeah Haven you saw + + + align:start position:0% +boys yeah Haven you saw +partition here yes yes I could express + + align:start position:0% +partition here yes yes I could express + + + align:start position:0% +partition here yes yes I could express +this in graph language too that's right + + align:start position:0% +this in graph language too that's right + + + align:start position:0% +this in graph language too that's right +that's right yeah uh it's it's yeah it's + + align:start position:0% +that's right yeah uh it's it's yeah it's + + + align:start position:0% +that's right yeah uh it's it's yeah it's +it's + + align:start position:0% +it's + + + align:start position:0% +it's +a you know the problem sounds like a j + + align:start position:0% +a you know the problem sounds like a j + + + align:start position:0% +a you know the problem sounds like a j +problem but it appears all over the + + align:start position:0% +problem but it appears all over the + + + align:start position:0% +problem but it appears all over the +place as it's a very quite a fundamental + + align:start position:0% +place as it's a very quite a fundamental + + + align:start position:0% +place as it's a very quite a fundamental +matching so that's why matching is the + + align:start position:0% +matching so that's why matching is the + + + align:start position:0% +matching so that's why matching is the +or assign sometimes assignment problem + + align:start position:0% +or assign sometimes assignment problem + + + align:start position:0% +or assign sometimes assignment problem +is were used but matching is and a + + align:start position:0% +is were used but matching is and a + + + align:start position:0% +is were used but matching is and a +perfect matching is is complete matching + + align:start position:0% +perfect matching is is complete matching + + + align:start position:0% +perfect matching is is complete matching +yeah so it's uh so that's the matching + + align:start position:0% +yeah so it's uh so that's the matching + + + align:start position:0% +yeah so it's uh so that's the matching +problem so maybe I could and and it + + align:start position:0% +problem so maybe I could and and it + + + align:start position:0% +problem so maybe I could and and it +connects to this type of bipar I + + align:start position:0% +connects to this type of bipar I + + + align:start position:0% +connects to this type of bipar I +two-part graph okay um can I go to a + + align:start position:0% +two-part graph okay um can I go to a + + + align:start position:0% +two-part graph okay um can I go to a +second problem but any question on this + + align:start position:0% +second problem but any question on this + + + align:start position:0% +second problem but any question on this +one yeah yeah what happens if you like + + align:start position:0% +one yeah yeah what happens if you like + + + align:start position:0% +one yeah yeah what happens if you like +add + + align:start position:0% +add + + + align:start position:0% +add +another put three groups yes that so + + align:start position:0% +another put three groups yes that so + + + align:start position:0% +another put three groups yes that so +tripartite graph I don't + + align:start position:0% +tripartite graph I don't + + + align:start position:0% +tripartite graph I don't +know I don't know I mean it's that + + align:start position:0% +know I don't know I mean it's that + + + align:start position:0% +know I don't know I mean it's that +you're thinking like a graph theorist I + + align:start position:0% +you're thinking like a graph theorist I + + + align:start position:0% +you're thinking like a graph theorist I +mean this is how this subject + + align:start position:0% +mean this is how this subject + + + align:start position:0% +mean this is how this subject +grows um uh and uh and some directions + + align:start position:0% +grows um uh and uh and some directions + + + align:start position:0% +grows um uh and uh and some directions +lead to a beautiful theorem they're all + + align:start position:0% +lead to a beautiful theorem they're all + + + align:start position:0% +lead to a beautiful theorem they're all +going to lead to some Duality if you + + align:start position:0% +going to lead to some Duality if you + + + align:start position:0% +going to lead to some Duality if you +give me a linear program uh but + + align:start position:0% +give me a linear program uh but + + + align:start position:0% +give me a linear program uh but +um + + align:start position:0% +um + + + align:start position:0% +um +uh as I say I could have formulated this + + align:start position:0% +uh as I say I could have formulated this + + + align:start position:0% +uh as I say I could have formulated this +problem as a linear programming problem + + align:start position:0% +problem as a linear programming problem + + + align:start position:0% +problem as a linear programming problem +but and what's special about it is the + + align:start position:0% +but and what's special about it is the + + + align:start position:0% +but and what's special about it is the +corners would have turned out to be + + align:start position:0% +corners would have turned out to be + + + align:start position:0% +corners would have turned out to be +integers so that I only really had to + + align:start position:0% +integers so that I only really had to + + + align:start position:0% +integers so that I only really had to +look at integers and of course that's + + align:start position:0% +look at integers and of course that's + + + align:start position:0% +look at integers and of course that's +all I did just zeros and ones okay could + + align:start position:0% +all I did just zeros and ones okay could + + + align:start position:0% +all I did just zeros and ones okay could +I try to tell you about this Max flow + + align:start position:0% +I try to tell you about this Max flow + + + align:start position:0% +I try to tell you about this Max flow +problem uh I'll take let me take the + + align:start position:0% +problem uh I'll take let me take the + + + align:start position:0% +problem uh I'll take let me take the +example so now I'm going to have a + + align:start position:0% +example so now I'm going to have a + + + align:start position:0% +example so now I'm going to have a +network so now I'm doing Max flow well + + align:start position:0% +network so now I'm doing Max flow well + + + align:start position:0% +network so now I'm doing Max flow well +trees and graphs and and the example + + align:start position:0% +trees and graphs and and the example + + + align:start position:0% +trees and graphs and and the example +will be Max flow okay so so so + + align:start position:0% +will be Max flow okay so so so + + + align:start position:0% +will be Max flow okay so so so +graphs networks really networks and + + align:start position:0% +graphs networks really networks and + + + align:start position:0% +graphs networks really networks and +maximum flow okay okay so I'm going to + + align:start position:0% +maximum flow okay okay so I'm going to + + + align:start position:0% +maximum flow okay okay so I'm going to +draw a network here and it will have + + align:start position:0% +draw a network here and it will have + + + align:start position:0% +draw a network here and it will have +have uh a + + align:start position:0% +have uh a + + + align:start position:0% +have uh a +source and then + + align:start position:0% +source and then + + + align:start position:0% +source and then +edges through the network maybe maybe + + align:start position:0% +edges through the network maybe maybe + + + align:start position:0% +edges through the network maybe maybe +some more intermediate nodes and maybe + + align:start position:0% +some more intermediate nodes and maybe + + + align:start position:0% +some more intermediate nodes and maybe +some more intermediate nodes and then + + align:start position:0% +some more intermediate nodes and then + + + align:start position:0% +some more intermediate nodes and then +coming maybe some more nodes coming down + + align:start position:0% +coming maybe some more nodes coming down + + + align:start position:0% +coming maybe some more nodes coming down +to a + + align:start position:0% +to a + + + align:start position:0% +to a +sync S + + align:start position:0% +sync S + + + align:start position:0% +sync S +Prime now and I could connect some more + + align:start position:0% +Prime now and I could connect some more + + + align:start position:0% +Prime now and I could connect some more +of those I've forgotten whether I do in + + align:start position:0% +of those I've forgotten whether I do in + + + align:start position:0% +of those I've forgotten whether I do in +the uh in the problem + + align:start position:0% +the uh in the problem + + + align:start position:0% +the uh in the problem +here uh let me just F I'm just going to + + align:start position:0% +here uh let me just F I'm just going to + + + align:start position:0% +here uh let me just F I'm just going to +take the example that's in the + + align:start position:0% +take the example that's in the + + + align:start position:0% +take the example that's in the +book yeah few more connections are in + + align:start position:0% +book yeah few more connections are in + + + align:start position:0% +book yeah few more connections are in +here here to here here to here there + + align:start position:0% +here here to here here to here there + + + align:start position:0% +here here to here here to here there +okay now the point is I'm going to give + + align:start position:0% +okay now the point is I'm going to give + + + align:start position:0% +okay now the point is I'm going to give +capacities all those + + align:start position:0% +capacities all those + + + align:start position:0% +capacities all those +edges the edges that are not in there + + align:start position:0% +edges the edges that are not in there + + + align:start position:0% +edges the edges that are not in there +have capacity zero can't send any flow + + align:start position:0% +have capacity zero can't send any flow + + + align:start position:0% +have capacity zero can't send any flow +and all the other edges I'm going to put + + align:start position:0% +and all the other edges I'm going to put + + + align:start position:0% +and all the other edges I'm going to put +in capacities and let me put those in in + + align:start position:0% +in capacities and let me put those in in + + + align:start position:0% +in capacities and let me put those in in +yellow so here here are the capacities + + align:start position:0% +yellow so here here are the capacities + + + align:start position:0% +yellow so here here are the capacities +of these edges five 7 and N so this was + + align:start position:0% +of these edges five 7 and N so this was + + + align:start position:0% +of these edges five 7 and N so this was +the sink the source + + align:start position:0% +the sink the source + + + align:start position:0% +the sink the source +source 57 9 2 two on those vertical + + align:start position:0% +source 57 9 2 two on those vertical + + + align:start position:0% +source 57 9 2 two on those vertical +edges 1 14 and + + align:start position:0% +edges 1 14 and + + + align:start position:0% +edges 1 14 and +1 one and one on those edges and 68 and + + align:start position:0% +1 one and one on those edges and 68 and + + + align:start position:0% +1 one and one on those edges and 68 and +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +five on those + + align:start position:0% +five on those + + + align:start position:0% +five on those +edges and I'm just going to ask you send + + align:start position:0% +edges and I'm just going to ask you send + + + align:start position:0% +edges and I'm just going to ask you send +as much as possible from the sink source + + align:start position:0% +as much as possible from the sink source + + + align:start position:0% +as much as possible from the sink source +to the + + align:start position:0% +to the + + + align:start position:0% +to the +sink how much flow so that's the maximum + + align:start position:0% +sink how much flow so that's the maximum + + + align:start position:0% +sink how much flow so that's the maximum +flow problem Max flow maximize flow + + align:start position:0% +flow problem Max flow maximize flow + + + align:start position:0% +flow problem Max flow maximize flow +from source to + + align:start position:0% + + + + align:start position:0% + +sink and of course what's the + + align:start position:0% +sink and of course what's the + + + align:start position:0% +sink and of course what's the +constraint the flows have to be so + + align:start position:0% +constraint the flows have to be so + + + align:start position:0% +constraint the flows have to be so +there's a flow on these edges and the + + align:start position:0% +there's a flow on these edges and the + + + align:start position:0% +there's a flow on these edges and the +flows have to be non- + + align:start position:0% +flows have to be non- + + + align:start position:0% +flows have to be non- +negative let's say but they can't exceed + + align:start position:0% +negative let's say but they can't exceed + + + align:start position:0% +negative let's say but they can't exceed +the capacity the + + align:start position:0% +the capacity the + + + align:start position:0% +the capacity the +flow less or equal to the capacity + + align:start position:0% +flow less or equal to the capacity + + + align:start position:0% +flow less or equal to the capacity +that's where our inequality really comes + + align:start position:0% +that's where our inequality really comes + + + align:start position:0% +that's where our inequality really comes +on each Edge each + + align:start position:0% + + + + align:start position:0% + +Edge the flow has to be less or equal + + align:start position:0% +Edge the flow has to be less or equal + + + align:start position:0% +Edge the flow has to be less or equal +the + + align:start position:0% + + + + align:start position:0% + +capacity + + align:start position:0% +capacity + + + align:start position:0% +capacity +uh I yes I I it's like steady state or + + align:start position:0% +uh I yes I I it's like steady state or + + + align:start position:0% +uh I yes I I it's like steady state or +something I I'm thinking of those yeah + + align:start position:0% +something I I'm thinking of those yeah + + + align:start position:0% +something I I'm thinking of those yeah +I've got a bunch of stuff at the + + align:start position:0% +I've got a bunch of stuff at the + + + align:start position:0% +I've got a bunch of stuff at the +source like um trucks or whatever and + + align:start position:0% +source like um trucks or whatever and + + + align:start position:0% +source like um trucks or whatever and +I've got to send them to the sink + + align:start position:0% +I've got to send them to the sink + + + align:start position:0% +I've got to send them to the sink +and I can't send more so for example I + + align:start position:0% +and I can't send more so for example I + + + align:start position:0% +and I can't send more so for example I +absolutely my my capacity is certainly + + align:start position:0% +absolutely my my capacity is certainly + + + align:start position:0% +absolutely my my capacity is certainly +my flow is less than what I certainly + + align:start position:0% +my flow is less than what I certainly + + + align:start position:0% +my flow is less than what I certainly +can't send more than 5 S9 + + align:start position:0% +can't send more than 5 S9 + + + align:start position:0% +can't send more than 5 S9 +21 absolutely but can I send 21 + + align:start position:0% +21 absolutely but can I send 21 + + + align:start position:0% +21 absolutely but can I send 21 +why + + align:start position:0% +why + + + align:start position:0% +why +not solving my problem + + align:start position:0% + + + + align:start position:0% + +already at the sink I could only get 19 + + align:start position:0% +already at the sink I could only get 19 + + + align:start position:0% +already at the sink I could only get 19 +to the sink + + align:start position:0% +to the sink + + + align:start position:0% +to the sink +okay I can't even send 19 across the + + align:start position:0% +okay I can't even send 19 across the + + + align:start position:0% +okay I can't even send 19 across the +middle I could send + + align:start position:0% +middle I could send + + + align:start position:0% +middle I could send +16 you but I can't get 16 through no + + align:start position:0% +16 you but I can't get 16 through no + + + align:start position:0% +16 you but I can't get 16 through no +yeah this is fun right yes + + align:start position:0% +yeah this is fun right yes + + + align:start position:0% +yeah this is fun right yes +basically what how so what's your since + + align:start position:0% +basically what how so what's your since + + + align:start position:0% +basically what how so what's your since +you spoke up first you one second across + + align:start position:0% +you spoke up first you one second across + + + align:start position:0% +you spoke up first you one second across +the + + align:start position:0% + + + + align:start position:0% + +yes that's + + align:start position:0% + + + + align:start position:0% + +right up and one + + align:start position:0% + + + + align:start position:0% + +down right so your total your Capa your + + align:start position:0% +down right so your total your Capa your + + + align:start position:0% +down right so your total your Capa your +maximum is 12 that looks all right I + + align:start position:0% +maximum is 12 that looks all right I + + + align:start position:0% +maximum is 12 that looks all right I +think that sounds right so just to + + align:start position:0% +think that sounds right so just to + + + align:start position:0% +think that sounds right so just to +repeat + + align:start position:0% + + + + align:start position:0% + +the 's I'm going to create a + + align:start position:0% +the 's I'm going to create a + + + align:start position:0% +the 's I'm going to create a +cut and and make the whole point here + + align:start position:0% +cut and and make the whole point here + + + align:start position:0% +cut and and make the whole point here +there's a cut here if I cut the network + + align:start position:0% +there's a cut here if I cut the network + + + align:start position:0% +there's a cut here if I cut the network +along + + align:start position:0% +along + + + align:start position:0% +along +that line so these guys are with the + + align:start position:0% +that line so these guys are with the + + + align:start position:0% +that line so these guys are with the +source and these guys are with the + + align:start position:0% +source and these guys are with the + + + align:start position:0% +source and these guys are with the +sink then I'm going to look how many can + + align:start position:0% +sink then I'm going to look how many can + + + align:start position:0% +sink then I'm going to look how many can +I get across the cut because I have to + + align:start position:0% +I get across the cut because I have to + + + align:start position:0% +I get across the cut because I have to +get it across the + + align:start position:0% + + + + align:start position:0% + +cut + + align:start position:0% +cut + + + align:start position:0% +cut +and if I can do it the what's so what's + + align:start position:0% +and if I can do it the what's so what's + + + align:start position:0% +and if I can do it the what's so what's +the capacity of that cut 12 12 the the + + align:start position:0% +the capacity of that cut 12 12 the the + + + align:start position:0% +the capacity of that cut 12 12 the the +total that can cross is if I Cross by + + align:start position:0% +total that can cross is if I Cross by + + + align:start position:0% +total that can cross is if I Cross by +that edge one can cross if I Cross by + + align:start position:0% +that edge one can cross if I Cross by + + + align:start position:0% +that edge one can cross if I Cross by +that edge one more this way eight this + + align:start position:0% +that edge one more this way eight this + + + align:start position:0% +that edge one more this way eight this +way one this way one so if I'm going + + align:start position:0% +way one this way one so if I'm going + + + align:start position:0% +way one this way one so if I'm going +from this side of the cut to that side I + + align:start position:0% +from this side of the cut to that side I + + + align:start position:0% +from this side of the cut to that side I +cannot get more than 12 just the way I + + align:start position:0% +cannot get more than 12 just the way I + + + align:start position:0% +cannot get more than 12 just the way I +couldn't get more than 21 I mean we did + + align:start position:0% +couldn't get more than 21 I mean we did + + + align:start position:0% +couldn't get more than 21 I mean we did +a and you see the weak + + align:start position:0% +a and you see the weak + + + align:start position:0% +a and you see the weak +Duality as soon as I say hey I can't get + + align:start position:0% +Duality as soon as I say hey I can't get + + + align:start position:0% +Duality as soon as I say hey I can't get +more than 21 obvious I can't get more + + align:start position:0% +more than 21 obvious I can't get more + + + align:start position:0% +more than 21 obvious I can't get more +than 19 almost as obvious I can't get + + align:start position:0% +than 19 almost as obvious I can't get + + + align:start position:0% +than 19 almost as obvious I can't get +more than 16 almost as obvious I can't + + align:start position:0% +more than 16 almost as obvious I can't + + + align:start position:0% +more than 16 almost as obvious I can't +get more than + + align:start position:0% +get more than + + + align:start position:0% +get more than +12 less + + align:start position:0% + + + + align:start position:0% + +obvious sorry the way you dra + + align:start position:0% +obvious sorry the way you dra + + + align:start position:0% +obvious sorry the way you dra +yes that it's less + + align:start position:0% +yes that it's less + + + align:start position:0% +yes that it's less +obvious you could yeah + + align:start position:0% +obvious you could yeah + + + align:start position:0% +obvious you could yeah +yeah I could have made that cut jump out + + align:start position:0% +yeah I could have made that cut jump out + + + align:start position:0% +yeah I could have made that cut jump out +all right yes but of course to the + + align:start position:0% +all right yes but of course to the + + + align:start position:0% +all right yes but of course to the +computer nothing is going to jump out so + + align:start position:0% +computer nothing is going to jump out so + + + align:start position:0% +computer nothing is going to jump out so +so we so in the end uh to solve a big + + align:start position:0% +so we so in the end uh to solve a big + + + align:start position:0% +so we so in the end uh to solve a big +problem which would be beyond our + + align:start position:0% +problem which would be beyond our + + + align:start position:0% +problem which would be beyond our +capacity we're going to hand it to the + + align:start position:0% +capacity we're going to hand it to the + + + align:start position:0% +capacity we're going to hand it to the +computer so we're going to the + + align:start position:0% +computer so we're going to the + + + align:start position:0% +computer so we're going to the +computer's going to be given the + + align:start position:0% +computer's going to be given the + + + align:start position:0% +computer's going to be given the +statement will be the capacities on all + + align:start position:0% +statement will be the capacities on all + + + align:start position:0% +statement will be the capacities on all +the + + align:start position:0% +the + + + align:start position:0% +the +edges and zero zero capacity on the on + + align:start position:0% +edges and zero zero capacity on the on + + + align:start position:0% +edges and zero zero capacity on the on +the uh absent + + align:start position:0% +the uh absent + + + align:start position:0% +the uh absent +edges and and of course as you can + + align:start position:0% +edges and and of course as you can + + + align:start position:0% +edges and and of course as you can +imagine we could allow ow different + + align:start position:0% +imagine we could allow ow different + + + align:start position:0% +imagine we could allow ow different +capacities in the two directions which + + align:start position:0% +capacities in the two directions which + + + align:start position:0% +capacities in the two directions which +would make the problem a little harder + + align:start position:0% +would make the problem a little harder + + + align:start position:0% +would make the problem a little harder +it be twice as many + + align:start position:0% +it be twice as many + + + align:start position:0% +it be twice as many +input for the for the program to deal + + align:start position:0% +input for the for the program to deal + + + align:start position:0% +input for the for the program to deal +with but still it would be a + + align:start position:0% +with but still it would be a + + + align:start position:0% +with but still it would be a +inequality set of inequality constraints + + align:start position:0% +inequality set of inequality constraints + + + align:start position:0% +inequality set of inequality constraints +and that it'd be a linear + + align:start position:0% +and that it'd be a linear + + + align:start position:0% +and that it'd be a linear +program and the beauty so the what's + + align:start position:0% +program and the beauty so the what's + + + align:start position:0% +program and the beauty so the what's +what's my main theorem here well I've + + align:start position:0% +what's my main theorem here well I've + + + align:start position:0% +what's my main theorem here well I've +stated it that maximum flow equals + + align:start position:0% +stated it that maximum flow equals + + + align:start position:0% +stated it that maximum flow equals +minimum + + align:start position:0% +minimum + + + align:start position:0% +minimum +That's The + + align:start position:0% +That's The + + + align:start position:0% +That's The +Duality the fact that maximum flow is + + align:start position:0% +Duality the fact that maximum flow is + + + align:start position:0% +Duality the fact that maximum flow is +less or equal that every flow is less + + align:start position:0% +less or equal that every flow is less + + + align:start position:0% +less or equal that every flow is less +than or equal to any cut is clear that's + + align:start position:0% +than or equal to any cut is clear that's + + + align:start position:0% +than or equal to any cut is clear that's +the weak Duality that's easy I can't + + align:start position:0% +the weak Duality that's easy I can't + + + align:start position:0% +the weak Duality that's easy I can't +send more flow across + + align:start position:0% +send more flow across + + + align:start position:0% +send more flow across +that that barbwire fence than the + + align:start position:0% +that that barbwire fence than the + + + align:start position:0% +that that barbwire fence than the +capacity of all the edges that cross it + + align:start position:0% +capacity of all the edges that cross it + + + align:start position:0% +capacity of all the edges that cross it +you see what the capacity of the cut is + + align:start position:0% +you see what the capacity of the cut is + + + align:start position:0% +you see what the capacity of the cut is +so the Capac what's what do I mean by + + align:start position:0% +so the Capac what's what do I mean by + + + align:start position:0% +so the Capac what's what do I mean by +the capacity of a + + align:start position:0% +the capacity of a + + + align:start position:0% +the capacity of a +cut of a of a cut first of all what is a + + align:start position:0% + + + + align:start position:0% + +cut a cut is and it didn't look quite as + + align:start position:0% +cut a cut is and it didn't look quite as + + + align:start position:0% +cut a cut is and it didn't look quite as +neat as don't think I didn't you thought + + align:start position:0% +neat as don't think I didn't you thought + + + align:start position:0% +neat as don't think I didn't you thought +I made that picture hard but at least + + align:start position:0% +I made that picture hard but at least + + + align:start position:0% +I made that picture hard but at least +the cut looked reasonable so a cut is + + align:start position:0% +the cut looked reasonable so a cut is + + + align:start position:0% +the cut looked reasonable so a cut is +any any way of separating The Source + + align:start position:0% +any any way of separating The Source + + + align:start position:0% +any any way of separating The Source +from the sink anything that I have to + + align:start position:0% +from the sink anything that I have to + + + align:start position:0% +from the sink anything that I have to +Traverse any like boundary and the cap + + align:start position:0% +Traverse any like boundary and the cap + + + align:start position:0% +Traverse any like boundary and the cap +what's the capacity of a + + align:start position:0% +what's the capacity of a + + + align:start position:0% +what's the capacity of a +cut it's the sum across it's how much + + align:start position:0% +cut it's the sum across it's how much + + + align:start position:0% +cut it's the sum across it's how much +it's the sum I look at all the edges + + align:start position:0% +it's the sum I look at all the edges + + + align:start position:0% +it's the sum I look at all the edges +that cross the cut how much can I send + + align:start position:0% +that cross the cut how much can I send + + + align:start position:0% +that cross the cut how much can I send +that's the capacity of a cut and then + + align:start position:0% +that's the capacity of a cut and then + + + align:start position:0% +that's the capacity of a cut and then +I'm look for the cut that's tightest so + + align:start position:0% +I'm look for the cut that's tightest so + + + align:start position:0% +I'm look for the cut that's tightest so +then the Dual problem is of course is a + + align:start position:0% +then the Dual problem is of course is a + + + align:start position:0% +then the Dual problem is of course is a +minimum problem find the cut of smallest + + align:start position:0% +minimum problem find the cut of smallest + + + align:start position:0% +minimum problem find the cut of smallest +capacity so the capacity of the tightest + + align:start position:0% +capacity so the capacity of the tightest + + + align:start position:0% +capacity so the capacity of the tightest +cut equals + + align:start position:0% +cut equals + + + align:start position:0% +cut equals +the maximum flow I can send what about + + align:start position:0% +the maximum flow I can send what about + + + align:start position:0% +the maximum flow I can send what about +correction those up going always going + + align:start position:0% +correction those up going always going + + + align:start position:0% +correction those up going always going +up always going from from source to sync + + align:start position:0% +up always going from from source to sync + + + align:start position:0% +up always going from from source to sync +that's that's right if if the capacity + + align:start position:0% +that's that's right if if the capacity + + + align:start position:0% +that's that's right if if the capacity +was different both the two ways I'm only + + align:start position:0% +was different both the two ways I'm only + + + align:start position:0% +was different both the two ways I'm only +going to look at the capacity that's + + align:start position:0% +going to look at the capacity that's + + + align:start position:0% +going to look at the capacity that's +going from the S sink source side to the + + align:start position:0% +going from the S sink source side to the + + + align:start position:0% +going from the S sink source side to the +sink + + align:start position:0% + + + + align:start position:0% + +side why do you think is that always the + + align:start position:0% +side why do you think is that always the + + + align:start position:0% +side why do you think is that always the +way + + align:start position:0% +way + + + align:start position:0% +way +the CH those cap + + align:start position:0% +the CH those cap + + + align:start position:0% +the CH those cap +maybe oh yeah the optimal + + align:start position:0% +maybe oh yeah the optimal + + + align:start position:0% +maybe oh yeah the optimal +flow all I'm saying is that once I have + + align:start position:0% +flow all I'm saying is that once I have + + + align:start position:0% +flow all I'm saying is that once I have +found the minimal cut that's the that's + + align:start position:0% +found the minimal cut that's the that's + + + align:start position:0% +found the minimal cut that's the that's +the tight one and I better send + + align:start position:0% +the tight one and I better send + + + align:start position:0% +the tight one and I better send +everything I have to send to to to + + align:start position:0% +everything I have to send to to to + + + align:start position:0% +everything I have to send to to to +achieve so the claim is that there's + + align:start position:0% +achieve so the claim is that there's + + + align:start position:0% +achieve so the claim is that there's +some flow that that if this is the + + align:start position:0% +some flow that that if this is the + + + align:start position:0% +some flow that that if this is the +minimal cut that I can fix up stuff here + + align:start position:0% +minimal cut that I can fix up stuff here + + + align:start position:0% +minimal cut that I can fix up stuff here +which isn't doing the minimum and fix up + + align:start position:0% +which isn't doing the minimum and fix up + + + align:start position:0% +which isn't doing the minimum and fix up +stuff here and maybe send it whatever + + align:start position:0% +stuff here and maybe send it whatever + + + align:start position:0% +stuff here and maybe send it whatever +way you're right I I'm not I'm only + + align:start position:0% +way you're right I I'm not I'm only + + + align:start position:0% +way you're right I I'm not I'm only +saying that across the cut I'm going to + + align:start position:0% +saying that across the cut I'm going to + + + align:start position:0% +saying that across the cut I'm going to +go from source to sync I'm not saying + + align:start position:0% +go from source to sync I'm not saying + + + align:start position:0% +go from source to sync I'm not saying +which way or how much flow goes on these + + align:start position:0% +which way or how much flow goes on these + + + align:start position:0% +which way or how much flow goes on these +other edges because that's where things + + align:start position:0% +other edges because that's where things + + + align:start position:0% +other edges because that's where things +are slack I've got extra capacity it's + + align:start position:0% +are slack I've got extra capacity it's + + + align:start position:0% +are slack I've got extra capacity it's +like having extra ones here I don't you + + align:start position:0% +like having extra ones here I don't you + + + align:start position:0% +like having extra ones here I don't you +know they're there but I don't use them + + align:start position:0% +know they're there but I don't use them + + + align:start position:0% +know they're there but I don't use them +but the ones that the matching the ones + + align:start position:0% +but the ones that the matching the ones + + + align:start position:0% +but the ones that the matching the ones +that I needed I needed and the capacity + + align:start position:0% +that I needed I needed and the capacity + + + align:start position:0% +that I needed I needed and the capacity +across that cut I need + + align:start position:0% +across that cut I need + + + align:start position:0% +across that cut I need +it yeah if you made that capacity n + + align:start position:0% +it yeah if you made that capacity n + + + align:start position:0% +it yeah if you made that capacity n +instead of 14 all right let me change + + align:start position:0% +instead of 14 all right let me change + + + align:start position:0% +instead of 14 all right let me change +would that mean you can only get a + + align:start position:0% +would that mean you can only get a + + + align:start position:0% +would that mean you can only get a +maximum of + + align:start position:0% +maximum of + + + align:start position:0% +maximum of +11 well because you can't Supply 10 that + + align:start position:0% +11 well because you can't Supply 10 that + + + align:start position:0% +11 well because you can't Supply 10 that +looks so you're saying is the minimal + + align:start position:0% +looks so you're saying is the minimal + + + align:start position:0% +looks so you're saying is the minimal +cut + + align:start position:0% +cut + + + align:start position:0% +cut +now now this no I mean is is the maximum + + align:start position:0% +now now this no I mean is is the maximum + + + align:start position:0% +now now this no I mean is is the maximum +through put down to the think S Prime is + + align:start position:0% +through put down to the think S Prime is + + + align:start position:0% +through put down to the think S Prime is +that going to be 11 instead of well I I + + align:start position:0% +that going to be 11 instead of well I I + + + align:start position:0% +that going to be 11 instead of well I I +asked the same question yeah yeah yeah + + align:start position:0% +asked the same question yeah yeah yeah + + + align:start position:0% +asked the same question yeah yeah yeah +have have you have we reduced have we + + align:start position:0% +have have you have we reduced have we + + + align:start position:0% +have have you have we reduced have we +now found a cut whose capacity is only + + align:start position:0% +now found a cut whose capacity is only + + + align:start position:0% +now found a cut whose capacity is only +11 so the theorem would say if that's + + align:start position:0% +11 so the theorem would say if that's + + + align:start position:0% +11 so the theorem would say if that's +the smallest and probably it is the + + align:start position:0% +the smallest and probably it is the + + + align:start position:0% +the smallest and probably it is the +theorem would say well we can get 11 + + align:start position:0% +theorem would say well we can get 11 + + + align:start position:0% +theorem would say well we can get 11 +through that's the the if that's the + + align:start position:0% +through that's the the if that's the + + + align:start position:0% +through that's the the if that's the +smallest capacity if the if the tight + + align:start position:0% +smallest capacity if the if the tight + + + align:start position:0% +smallest capacity if the if the tight +one now is is is this + + align:start position:0% +one now is is is this + + + align:start position:0% +one now is is is this +cut + + align:start position:0% +cut + + + align:start position:0% +cut +then the cap we can send no more than 11 + + align:start position:0% +then the cap we can send no more than 11 + + + align:start position:0% +then the cap we can send no more than 11 +and the theorem would say yep we can get + + align:start position:0% +and the theorem would say yep we can get + + + align:start position:0% +and the theorem would say yep we can get +11 through if that's the tightest cut do + + align:start position:0% +11 through if that's the tightest cut do + + + align:start position:0% +11 through if that's the tightest cut do +you see that like the beauty of the the + + align:start position:0% +you see that like the beauty of the the + + + align:start position:0% +you see that like the beauty of the the +Elegance of the answer that that uh that + + align:start position:0% +Elegance of the answer that that uh that + + + align:start position:0% +Elegance of the answer that that uh that +tightest cut is exactly what you can get + + align:start position:0% +tightest cut is exactly what you can get + + + align:start position:0% +tightest cut is exactly what you can get +through and and and you see that is + + align:start position:0% +through and and and you see that is + + + align:start position:0% +through and and and you see that is +exactly constrain it's the tight + + align:start position:0% +exactly constrain it's the tight + + + align:start position:0% +exactly constrain it's the tight +constraint yeah that was a good idea to + + align:start position:0% +constraint yeah that was a good idea to + + + align:start position:0% +constraint yeah that was a good idea to +change a number should I change a a + + align:start position:0% +change a number should I change a a + + + align:start position:0% +change a number should I change a a +different number just solve the problem + + align:start position:0% +different number just solve the problem + + + align:start position:0% +different number just solve the problem +once + + align:start position:0% +once + + + align:start position:0% +once +more so let me go back to 14 + + align:start position:0% +more so let me go back to 14 + + + align:start position:0% +more so let me go back to 14 +here and let me change a few other + + align:start position:0% +here and let me change a few other + + + align:start position:0% +here and let me change a few other +numbers let me increase this one to a + + align:start position:0% +numbers let me increase this one to a + + + align:start position:0% +numbers let me increase this one to a +three I'm just doing this at random and + + align:start position:0% +three I'm just doing this at random and + + + align:start position:0% +three I'm just doing this at random and +reduce that two to a one and this nine + + align:start position:0% +reduce that two to a one and this nine + + + align:start position:0% +reduce that two to a one and this nine +to a six + + align:start position:0% +to a six + + + align:start position:0% +to a six +okay is it clear enough can you see what + + align:start position:0% +okay is it clear enough can you see what + + + align:start position:0% +okay is it clear enough can you see what +those numbers are + + align:start position:0% +those numbers are + + + align:start position:0% +those numbers are +so that's still a + + align:start position:0% +so that's still a + + + align:start position:0% +so that's still a +one well I'm asking you to solve a + + align:start position:0% +one well I'm asking you to solve a + + + align:start position:0% +one well I'm asking you to solve a +problem on the Fly here but then you you + + align:start position:0% +problem on the Fly here but then you you + + + align:start position:0% +problem on the Fly here but then you you +think 12 is now the + + align:start position:0% +think 12 is now the + + + align:start position:0% +think 12 is now the +minimum have seven and which 12 where's + + align:start position:0% +minimum have seven and which 12 where's + + + align:start position:0% +minimum have seven and which 12 where's +the cut go through the seven + + align:start position:0% +the cut go through the seven + + + align:start position:0% +the cut go through the seven +and the seven one one to and oh through + + align:start position:0% +and the seven one one to and oh through + + + align:start position:0% +and the seven one one to and oh through +down here through that one through that + + align:start position:0% +down here through that one through that + + + align:start position:0% +down here through that one through that +seven through that two and that one yeah + + align:start position:0% +seven through that two and that one yeah + + + align:start position:0% +seven through that two and that one yeah +so 2 1 + + align:start position:0% + + + + align:start position:0% + + + align:start position:0% + + + align:start position:0% +12 and that if that's a minimal cut then + + align:start position:0% +12 and that if that's a minimal cut then + + + align:start position:0% +12 and that if that's a minimal cut then +I can get 12 through minim C well you + + align:start position:0% +I can get 12 through minim C well you + + + align:start position:0% +I can get 12 through minim C well you +just added to the other cut that was the + + align:start position:0% +just added to the other cut that was the + + + align:start position:0% +just added to the other cut that was the +minimal cut so therefore that + + align:start position:0% +minimal cut so therefore that + + + align:start position:0% +minimal cut so therefore that +cut yeah let's see this old cut how many + + align:start position:0% +cut yeah let's see this old cut how many + + + align:start position:0% +cut yeah let's see this old cut how many +can get through there one and one and + + align:start position:0% +can get through there one and one and + + + align:start position:0% +can get through there one and one and +eight and three and one oh I did I leave + + align:start position:0% +eight and three and one oh I did I leave + + + align:start position:0% +eight and three and one oh I did I leave +no I I increased that didn't I yeah so + + align:start position:0% +no I I increased that didn't I yeah so + + + align:start position:0% +no I I increased that didn't I yeah so +14 was that old cut but now I by + + align:start position:0% +14 was that old cut but now I by + + + align:start position:0% +14 was that old cut but now I by +reducing this seven reducing oh reducing + + align:start position:0% +reducing this seven reducing oh reducing + + + align:start position:0% +reducing this seven reducing oh reducing +some of these others I reduce some other + + align:start position:0% +some of these others I reduce some other + + + align:start position:0% +some of these others I reduce some other +cut to 12 we said so then the theorem + + align:start position:0% +cut to 12 we said so then the theorem + + + align:start position:0% +cut to 12 we said so then the theorem +would say the and we don't see + + align:start position:0% +would say the and we don't see + + + align:start position:0% +would say the and we don't see +immediately how but with a little + + align:start position:0% +immediately how but with a little + + + align:start position:0% +immediately how but with a little +patience we would figure out a way to + + align:start position:0% +patience we would figure out a way to + + + align:start position:0% +patience we would figure out a way to +send 12 through if if that's really we + + align:start position:0% +send 12 through if if that's really we + + + align:start position:0% +send 12 through if if that's really we +couldn't send more than 12 that's for + + align:start position:0% +couldn't send more than 12 that's for + + + align:start position:0% +couldn't send more than 12 that's for +sure because you've identified a cut + + align:start position:0% +sure because you've identified a cut + + + align:start position:0% +sure because you've identified a cut +with capacity 12 and then + + align:start position:0% +with capacity 12 and then + + + align:start position:0% +with capacity 12 and then +we've got some so we would we certainly + + align:start position:0% +we've got some so we would we certainly + + + align:start position:0% +we've got some so we would we certainly +know then we we got to send full amount + + align:start position:0% +know then we we got to send full amount + + + align:start position:0% +know then we we got to send full amount +across that cut we've got to send you + + align:start position:0% +across that cut we've got to send you + + + align:start position:0% +across that cut we've got to send you +know we've got to start on the answer + + align:start position:0% +know we've got to start on the answer + + + align:start position:0% +know we've got to start on the answer +because we know that we have to send + + align:start position:0% +because we know that we have to send + + + align:start position:0% +because we know that we have to send +seven that way and so forth and and and + + align:start position:0% +seven that way and so forth and and and + + + align:start position:0% +seven that way and so forth and and and +you know we know what all these ones + + align:start position:0% +you know we know what all these ones + + + align:start position:0% +you know we know what all these ones +should be and then we can fix the others + + align:start position:0% +should be and then we can fix the others + + + align:start position:0% +should be and then we can fix the others +to supply them where there's extra + + align:start position:0% +to supply them where there's extra + + + align:start position:0% +to supply them where there's extra +capacity that's a beautiful theorem and + + align:start position:0% +capacity that's a beautiful theorem and + + + align:start position:0% +capacity that's a beautiful theorem and +uh it would follow from some general + + align:start position:0% +uh it would follow from some general + + + align:start position:0% +uh it would follow from some general +Duality theorem of linear programming + + align:start position:0% +Duality theorem of linear programming + + + align:start position:0% +Duality theorem of linear programming +but then there would also be some + + align:start position:0% +but then there would also be some + + + align:start position:0% +but then there would also be some +special + + align:start position:0% +special + + + align:start position:0% +special +um uh argument like + + align:start position:0% +um uh argument like + + + align:start position:0% +um uh argument like +Halls uh condition that would apply and + + align:start position:0% +Halls uh condition that would apply and + + + align:start position:0% +Halls uh condition that would apply and +maybe I mentioned the the this Max flow + + align:start position:0% +maybe I mentioned the the this Max flow + + + align:start position:0% +maybe I mentioned the the this Max flow +Min cut is associated with Ford and + + align:start position:0% +Min cut is associated with Ford and + + + align:start position:0% +Min cut is associated with Ford and +Fulkerson where the sort of like + + align:start position:0% +Fulkerson where the sort of like + + + align:start position:0% +Fulkerson where the sort of like +comori Sparks to uh identify that uh + + align:start position:0% +comori Sparks to uh identify that uh + + + align:start position:0% +comori Sparks to uh identify that uh +um problem is there some systematic way + + align:start position:0% +um problem is there some systematic way + + + align:start position:0% +um problem is there some systematic way +of determining what the cut is besides + + align:start position:0% +of determining what the cut is besides + + + align:start position:0% +of determining what the cut is besides +yes that there would be right yes so the + + align:start position:0% +yes that there would be right yes so the + + + align:start position:0% +yes that there would be right yes so the +book would speak about that uh I + + align:start position:0% +book would speak about that uh I + + + align:start position:0% +book would speak about that uh I +mean one way is say I could write the + + align:start position:0% +mean one way is say I could write the + + + align:start position:0% +mean one way is say I could write the +whole thing as a linear program and use + + align:start position:0% +whole thing as a linear program and use + + + align:start position:0% +whole thing as a linear program and use +a Simplex + + align:start position:0% +a Simplex + + + align:start position:0% +a Simplex +method but then somehow the Simplex + + align:start position:0% +method but then somehow the Simplex + + + align:start position:0% +method but then somehow the Simplex +method should specialize to this problem + + align:start position:0% +method should specialize to this problem + + + align:start position:0% +method should specialize to this problem +and and uh + + align:start position:0% +and and uh + + + align:start position:0% +and and uh +um you know those those corners and so + + align:start position:0% +um you know those those corners and so + + + align:start position:0% +um you know those those corners and so +on should have a specific meaning in + + align:start position:0% +on should have a specific meaning in + + + align:start position:0% +on should have a specific meaning in +terms of flows and cuts yeah + + align:start position:0% + + + + align:start position:0% + +yeah particular example if you had one + + align:start position:0% +yeah particular example if you had one + + + align:start position:0% +yeah particular example if you had one +source and one sink yes you should only + + align:start position:0% +source and one sink yes you should only + + + align:start position:0% +source and one sink yes you should only +have one pipe so + + align:start position:0% +have one pipe so + + + align:start position:0% +have one pipe so +um well no think hey he I'm I'm a oil + + align:start position:0% +um well no think hey he I'm I'm a oil + + + align:start position:0% +um well no think hey he I'm I'm a oil +and gas I'm George Bush in a previous + + align:start position:0% +and gas I'm George Bush in a previous + + + align:start position:0% +and gas I'm George Bush in a previous +Incarnation yeah oh yeah I've got I'm + + align:start position:0% +Incarnation yeah oh yeah I've got I'm + + + align:start position:0% +Incarnation yeah oh yeah I've got I'm +getting natural gas off the G out of the + + align:start position:0% +getting natural gas off the G out of the + + + align:start position:0% +getting natural gas off the G out of the +Gulf of Mexico I've got pipelines going + + align:start position:0% +Gulf of Mexico I've got pipelines going + + + align:start position:0% +Gulf of Mexico I've got pipelines going +into the mainland and I've got + + align:start position:0% +into the mainland and I've got + + + align:start position:0% +into the mainland and I've got +refineries there with capacities and + + align:start position:0% +refineries there with capacities and + + + align:start position:0% +refineries there with capacities and +those pipelines are a real network of + + align:start position:0% +those pipelines are a real network of + + + align:start position:0% +those pipelines are a real network of +pipelines about yeah Elric yeah yeah + + align:start position:0% +pipelines about yeah Elric yeah yeah + + + align:start position:0% +pipelines about yeah Elric yeah yeah +that's sending electricity believe + + align:start position:0% +that's sending electricity believe + + + align:start position:0% +that's sending electricity believe +absolutely sending electricity + + align:start position:0% + + + + align:start position:0% + +California in this problem yeah oh I so + + align:start position:0% +California in this problem yeah oh I so + + + align:start position:0% +California in this problem yeah oh I so +I'm not claiming that's most General + + align:start position:0% +I'm not claiming that's most General + + + align:start position:0% +I'm not claiming that's most General +that this problem would fit every need + + align:start position:0% +that this problem would fit every need + + + align:start position:0% +that this problem would fit every need +no but you could make become a sync and + + align:start position:0% +no but you could make become a sync and + + + align:start position:0% +no but you could make become a sync and +then you could ask the same question I + + align:start position:0% +then you could ask the same question I + + + align:start position:0% +then you could ask the same question I +could have multiple sources and syncs + + align:start position:0% +could have multiple sources and syncs + + + align:start position:0% +could have multiple sources and syncs +and make the problem more General but + + align:start position:0% +and make the problem more General but + + + align:start position:0% +and make the problem more General but +more + + align:start position:0% + + + + align:start position:0% + +difficult + + align:start position:0% + + + + align:start position:0% + +true true + + align:start position:0% +true true + + + align:start position:0% +true true +true from York California + + align:start position:0% + + + + align:start position:0% + +yeah so it could be phone + + align:start position:0% + + + + align:start position:0% + +calls but if if you're calling one + + align:start position:0% +calls but if if you're calling one + + + align:start position:0% +calls but if if you're calling one +person in California then and you're + + align:start position:0% +person in California then and you're + + + align:start position:0% +person in California then and you're +sending a packet which can get split up + + align:start position:0% +sending a packet which can get split up + + + align:start position:0% +sending a packet which can get split up +in different ways and gets in fact isn't + + align:start position:0% +in different ways and gets in fact isn't + + + align:start position:0% +in different ways and gets in fact isn't +that what what AT&T is doing it's taking + + align:start position:0% +that what what AT&T is doing it's taking + + + align:start position:0% +that what what AT&T is doing it's taking +your phone message splitting it up into + + align:start position:0% +your phone message splitting it up into + + + align:start position:0% +your phone message splitting it up into +the packet sending them cheap ways and + + align:start position:0% +the packet sending them cheap ways and + + + align:start position:0% +the packet sending them cheap ways and +uh of course it's sending other packets + + align:start position:0% +uh of course it's sending other packets + + + align:start position:0% +uh of course it's sending other packets +at the same time so there there's + + align:start position:0% +at the same time so there there's + + + align:start position:0% +at the same time so there there's +another generalization we've got a bunch + + align:start position:0% +another generalization we've got a bunch + + + align:start position:0% +another generalization we've got a bunch +of different pairs Source sync pairs + + align:start position:0% +of different pairs Source sync pairs + + + align:start position:0% +of different pairs Source sync pairs +simultaneously trying to get their uh + + align:start position:0% +simultaneously trying to get their uh + + + align:start position:0% +simultaneously trying to get their uh +message through and then there's what's + + align:start position:0% + + + + align:start position:0% + +the right yeah that's my + + align:start position:0% +the right yeah that's my + + + align:start position:0% +the right yeah that's my +network yes obviously whoever designed + + align:start position:0% +network yes obviously whoever designed + + + align:start position:0% +network yes obviously whoever designed +this network right put too many put yeah + + align:start position:0% +this network right put too many put yeah + + + align:start position:0% +this network right put too many put yeah +whoever that that network isn't perfect + + align:start position:0% +whoever that that network isn't perfect + + + align:start position:0% +whoever that that network isn't perfect +because somebody paid extra for this + + align:start position:0% +because somebody paid extra for this + + + align:start position:0% +because somebody paid extra for this +paid for extra capacity that can't be + + align:start position:0% +paid for extra capacity that can't be + + + align:start position:0% +paid for extra capacity that can't be +used oh yeah that's right but actually + + align:start position:0% +used oh yeah that's right but actually + + + align:start position:0% +used oh yeah that's right but actually +in reality that happens all the time + + align:start position:0% +in reality that happens all the time + + + align:start position:0% +in reality that happens all the time +right if I mean a new pipeline is built + + align:start position:0% +right if I mean a new pipeline is built + + + align:start position:0% +right if I mean a new pipeline is built +from from Iraq to through turkey or + + align:start position:0% +from from Iraq to through turkey or + + + align:start position:0% +from from Iraq to through turkey or +wherever uh adds more capacity well then + + align:start position:0% +wherever uh adds more capacity well then + + + align:start position:0% +wherever uh adds more capacity well then +it turns out that that maybe you know + + align:start position:0% +it turns out that that maybe you know + + + align:start position:0% +it turns out that that maybe you know +now they've got excess Capac it but the + + align:start position:0% +now they've got excess Capac it but the + + + align:start position:0% +now they've got excess Capac it but the +minimum cut is what's determining how + + align:start position:0% +minimum cut is what's determining how + + + align:start position:0% +minimum cut is what's determining how +much flow gets you know from the oil + + align:start position:0% +much flow gets you know from the oil + + + align:start position:0% +much flow gets you know from the oil +fields to the to the + + align:start position:0% +fields to the to the + + + align:start position:0% +fields to the to the +refineries yeah and I could add a cost + + align:start position:0% +refineries yeah and I could add a cost + + + align:start position:0% +refineries yeah and I could add a cost +per node to to to go through that node + + align:start position:0% +per node to to to go through that node + + + align:start position:0% +per node to to to go through that node +oh you can imagine that I as long as I + + align:start position:0% +oh you can imagine that I as long as I + + + align:start position:0% +oh you can imagine that I as long as I +stay linear I I I I can make these + + align:start position:0% +stay linear I I I I can make these + + + align:start position:0% +stay linear I I I I can make these +things more General yeah yeah so I mean + + align:start position:0% +things more General yeah yeah so I mean + + + align:start position:0% +things more General yeah yeah so I mean +this this is really a good discussion + + align:start position:0% +this this is really a good discussion + + + align:start position:0% +this this is really a good discussion +that you know this is a model problem + + align:start position:0% +that you know this is a model problem + + + align:start position:0% +that you know this is a model problem +but but uh if we think about natural + + align:start position:0% +but but uh if we think about natural + + + align:start position:0% +but but uh if we think about natural +ways to make it closer and closer to + + align:start position:0% +ways to make it closer and closer to + + + align:start position:0% +ways to make it closer and closer to +reality we still stay with we still stay + + align:start position:0% +reality we still stay with we still stay + + + align:start position:0% +reality we still stay with we still stay +with uh this linear programming + + align:start position:0% +with uh this linear programming + + + align:start position:0% +with uh this linear programming +framework we can we can get a lot in + + align:start position:0% +framework we can we can get a lot in + + + align:start position:0% +framework we can we can get a lot in +well now I have to say though that + + align:start position:0% +well now I have to say though that + + + align:start position:0% +well now I have to say though that +multi-purpose you know so optimizing for + + align:start position:0% +multi-purpose you know so optimizing for + + + align:start position:0% +multi-purpose you know so optimizing for +multiple uses there that's that is + + align:start position:0% +multiple uses there that's that is + + + align:start position:0% +multiple uses there that's that is +really a different problem you know know + + align:start position:0% +really a different problem you know know + + + align:start position:0% +really a different problem you know know +if if I'm optimizing if I'm choosing the + + align:start position:0% +if if I'm optimizing if I'm choosing the + + + align:start position:0% +if if I'm optimizing if I'm choosing the +X's that optimize some function for + + align:start position:0% +X's that optimize some function for + + + align:start position:0% +X's that optimize some function for +several purposes op optimize several + + align:start position:0% +several purposes op optimize several + + + align:start position:0% +several purposes op optimize several +functions at once in some way uh that + + align:start position:0% +functions at once in some way uh that + + + align:start position:0% +functions at once in some way uh that +there I'm uh getting in you know by the + + align:start position:0% +there I'm uh getting in you know by the + + + align:start position:0% +there I'm uh getting in you know by the +way game + + align:start position:0% +way game + + + align:start position:0% +way game +theory is another example of linear + + align:start position:0% +theory is another example of linear + + + align:start position:0% +theory is another example of linear +programming and and vanoyan discovered + + align:start position:0% +programming and and vanoyan discovered + + + align:start position:0% +programming and and vanoyan discovered +that slightly + + align:start position:0% +that slightly + + + align:start position:0% +that slightly +before uh linear programming was + + align:start position:0% +before uh linear programming was + + + align:start position:0% +before uh linear programming was +discovered but almost the same time and + + align:start position:0% +discovered but almost the same time and + + + align:start position:0% +discovered but almost the same time and +people in the First Years even V noyman + + align:start position:0% +people in the First Years even V noyman + + + align:start position:0% +people in the First Years even V noyman +didn't instantly know and he instantly + + align:start position:0% +didn't instantly know and he instantly + + + align:start position:0% +didn't instantly know and he instantly +knew everything uh whe that it was the + + align:start position:0% +knew everything uh whe that it was the + + + align:start position:0% +knew everything uh whe that it was the +same and you do you remember the name of + + align:start position:0% +same and you do you remember the name of + + + align:start position:0% +same and you do you remember the name of +the fundamentals well I could talk about + + align:start position:0% +the fundamentals well I could talk about + + + align:start position:0% +the fundamentals well I could talk about +Game Theory I mean next time if you + + align:start position:0% +Game Theory I mean next time if you + + + align:start position:0% +Game Theory I mean next time if you +wanted among other problems uh the + + align:start position:0% +wanted among other problems uh the + + + align:start position:0% +wanted among other problems uh the +fundamental Duality there is called the + + align:start position:0% +fundamental Duality there is called the + + + align:start position:0% +fundamental Duality there is called the +Minimax theorem there's a Minimax equals + + align:start position:0% +Minimax theorem there's a Minimax equals + + + align:start position:0% +Minimax theorem there's a Minimax equals +a maxim + + align:start position:0% +a maxim + + + align:start position:0% +a maxim +Min in the in the world of Game Theory + + align:start position:0% +Min in the in the world of Game Theory + + + align:start position:0% +Min in the in the world of Game Theory +proved by V noyman the Minx theorem a + + align:start position:0% +proved by V noyman the Minx theorem a + + + align:start position:0% +proved by V noyman the Minx theorem a +minimum of a maximum of something is the + + align:start position:0% +minimum of a maximum of something is the + + + align:start position:0% +minimum of a maximum of something is the +maximum of the minimum of of something + + align:start position:0% + + + + align:start position:0% + +and uh in two in the twers game theory + + align:start position:0% +and uh in two in the twers game theory + + + align:start position:0% +and uh in two in the twers game theory +that vanman + + align:start position:0% +that vanman + + + align:start position:0% +that vanman +was about that would match a linear so + + align:start position:0% +was about that would match a linear so + + + align:start position:0% +was about that would match a linear so +that would match a linear program I + + align:start position:0% +that would match a linear program I + + + align:start position:0% +that would match a linear program I +could + + align:start position:0% + + + + align:start position:0% + +think this uh probably not + + align:start position:0% +think this uh probably not + + + align:start position:0% +think this uh probably not +I + + align:start position:0% +I + + + align:start position:0% +I +mean + + align:start position:0% + + + + align:start position:0% + +yeah yeah I well + + align:start position:0% +yeah yeah I well + + + align:start position:0% +yeah yeah I well +um the answer is yeah there's a duality + + align:start position:0% +um the answer is yeah there's a duality + + + align:start position:0% +um the answer is yeah there's a duality +in nonlinear + + align:start position:0% +in nonlinear + + + align:start position:0% +in nonlinear +programming there is but to tell you + + align:start position:0% +programming there is but to tell you + + + align:start position:0% +programming there is but to tell you +what the if you tell me one of the + + align:start position:0% +what the if you tell me one of the + + + align:start position:0% +what the if you tell me one of the +functions to tell you what the other is + + align:start position:0% +functions to tell you what the other is + + + align:start position:0% +functions to tell you what the other is +it's going to take me next week to do it + + align:start position:0% +it's going to take me next week to do it + + + align:start position:0% +it's going to take me next week to do it +uh it's not just like easy you see I I + + align:start position:0% +uh it's not just like easy you see I I + + + align:start position:0% +uh it's not just like easy you see I I +came up with that dual problem out of + + align:start position:0% +came up with that dual problem out of + + + align:start position:0% +came up with that dual problem out of +the blue really and but it wasn't + + align:start position:0% +the blue really and but it wasn't + + + align:start position:0% +the blue really and but it wasn't +totally out of the blue there was a + + align:start position:0% +totally out of the blue there was a + + + align:start position:0% +totally out of the blue there was a +there was a method there that could + + align:start position:0% +there was a method there that could + + + align:start position:0% +there was a method there that could +apply in nonlinear cases but not obvious + + align:start position:0% +apply in nonlinear cases but not obvious + + + align:start position:0% +apply in nonlinear cases but not obvious +anyway Game Theory two-person Game + + align:start position:0% +anyway Game Theory two-person Game + + + align:start position:0% +anyway Game Theory two-person Game +Theory would fit this U this setup and + + align:start position:0% +Theory would fit this U this setup and + + + align:start position:0% +Theory would fit this U this setup and +so the Minimax theorem is a is The + + align:start position:0% +so the Minimax theorem is a is The + + + align:start position:0% +so the Minimax theorem is a is The +Duality theorem threepers + + align:start position:0% +Duality theorem threepers + + + align:start position:0% +Duality theorem threepers +games you you know that's what John Nash + + align:start position:0% +games you you know that's what John Nash + + + align:start position:0% +games you you know that's what John Nash +won the Nobel Prize for he wrote a + + align:start position:0% +won the Nobel Prize for he wrote a + + + align:start position:0% +won the Nobel Prize for he wrote a +thesis so I didn't mention the other key + + align:start position:0% +thesis so I didn't mention the other key + + + align:start position:0% +thesis so I didn't mention the other key +names the this optimality condition is + + align:start position:0% +names the this optimality condition is + + + align:start position:0% +names the this optimality condition is +associated with and Tucker and now + + align:start position:0% +associated with and Tucker and now + + + align:start position:0% +associated with and Tucker and now +I've written down the great names in + + align:start position:0% +I've written down the great names in + + + align:start position:0% +I've written down the great names in +this subject and then uh John Nash who + + align:start position:0% +this subject and then uh John Nash who + + + align:start position:0% +this subject and then uh John Nash who +uh wrote his PhD ceases at Princeton + + align:start position:0% +uh wrote his PhD ceases at Princeton + + + align:start position:0% +uh wrote his PhD ceases at Princeton +under Tucker to everybody's surprise + + align:start position:0% +under Tucker to everybody's surprise + + + align:start position:0% +under Tucker to everybody's surprise +because Nash was a real character have + + align:start position:0% +because Nash was a real character have + + + align:start position:0% +because Nash was a real character have +you do you know this book The Beautiful + + align:start position:0% +you do you know this book The Beautiful + + + align:start position:0% +you do you know this book The Beautiful +a beautiful mind about John Nash who uh + + align:start position:0% +a beautiful mind about John Nash who uh + + + align:start position:0% +a beautiful mind about John Nash who uh +it's it may become a movie also movie + + align:start position:0% +it's it may become a movie also movie + + + align:start position:0% +it's it may become a movie also movie +movie rights have been B purchased um + + align:start position:0% +movie rights have been B purchased um + + + align:start position:0% +movie rights have been B purchased um +it's by Sylvia Nassar and it was on the + + align:start position:0% +it's by Sylvia Nassar and it was on the + + + align:start position:0% +it's by Sylvia Nassar and it was on the +best seller list so it's a biography of + + align:start position:0% +best seller list so it's a biography of + + + align:start position:0% +best seller list so it's a biography of +John Nash called A Beautiful + + align:start position:0% +John Nash called A Beautiful + + + align:start position:0% +John Nash called A Beautiful +Mind + + align:start position:0% +Mind + + + align:start position:0% +Mind +um uh so he won the Nobel Prize a few + + align:start position:0% +um uh so he won the Nobel Prize a few + + + align:start position:0% +um uh so he won the Nobel Prize a few +years ago but his life was a tra tragic + + align:start position:0% +years ago but his life was a tra tragic + + + align:start position:0% +years ago but his life was a tra tragic +story um well he was brilliant and + + align:start position:0% +story um well he was brilliant and + + + align:start position:0% +story um well he was brilliant and +actually for most mathem acian for all + + align:start position:0% +actually for most mathem acian for all + + + align:start position:0% +actually for most mathem acian for all +mathematicians the the what he got the + + align:start position:0% +mathematicians the the what he got the + + + align:start position:0% +mathematicians the the what he got the +his PhD thesis that he got the Nobel + + align:start position:0% +his PhD thesis that he got the Nobel + + + align:start position:0% +his PhD thesis that he got the Nobel +Prize for was not in any way the most + + align:start position:0% +Prize for was not in any way the most + + + align:start position:0% +Prize for was not in any way the most +deep and difficult work he did he went + + align:start position:0% +deep and difficult work he did he went + + + align:start position:0% +deep and difficult work he did he went +on to do prove + + align:start position:0% +on to do prove + + + align:start position:0% +on to do prove +remarkable facts in in high + + align:start position:0% +remarkable facts in in high + + + align:start position:0% +remarkable facts in in high +dimensional + + align:start position:0% +dimensional + + + align:start position:0% +dimensional +analysis and then uh + + align:start position:0% +analysis and then uh + + + align:start position:0% +analysis and then uh +schizophrenia uh took over so he had + + align:start position:0% +schizophrenia uh took over so he had + + + align:start position:0% +schizophrenia uh took over so he had +many many years when he was first around + + align:start position:0% +many many years when he was first around + + + align:start position:0% +many many years when he was first around +the MIT math department and then around + + align:start position:0% +the MIT math department and then around + + + align:start position:0% +the MIT math department and then around +around the longest time around the + + align:start position:0% +around the longest time around the + + + align:start position:0% +around the longest time around the +Princeton math department but really out + + align:start position:0% +Princeton math department but really out + + + align:start position:0% +Princeton math department but really out +of + + align:start position:0% +of + + + align:start position:0% +of +U communication with people uh it was + + align:start position:0% +U communication with people uh it was + + + align:start position:0% +U communication with people uh it was +difficult and then incredibly um + + align:start position:0% +difficult and then incredibly um + + + align:start position:0% +difficult and then incredibly um +recovered so he gave a lecture at MIT a + + align:start position:0% +recovered so he gave a lecture at MIT a + + + align:start position:0% +recovered so he gave a lecture at MIT a +few weeks ago in fact which uh where he + + align:start position:0% +few weeks ago in fact which uh where he + + + align:start position:0% +few weeks ago in fact which uh where he +had a standing room only audience + + align:start position:0% +had a standing room only audience + + + align:start position:0% +had a standing room only audience +um I I think people would feel he hasn't + + align:start position:0% +um I I think people would feel he hasn't + + + align:start position:0% +um I I think people would feel he hasn't +recovered to the incredible that he had + + align:start position:0% +recovered to the incredible that he had + + + align:start position:0% +recovered to the incredible that he had +reached before his illness but uh still + + align:start position:0% +reached before his illness but uh still + + + align:start position:0% +reached before his illness but uh still +amazing to have recovered so he was able + + align:start position:0% +amazing to have recovered so he was able + + + align:start position:0% +amazing to have recovered so he was able +to go to the Nobel Prize ceremony and + + align:start position:0% +to go to the Nobel Prize ceremony and + + + align:start position:0% +to go to the Nobel Prize ceremony and +the book is quite + + align:start position:0% +the book is quite + + + align:start position:0% +the book is quite +uh really uh good reporting uh I think + + align:start position:0% +uh really uh good reporting uh I think + + + align:start position:0% +uh really uh good reporting uh I think +um by Sylvia + + align:start position:0% +um by Sylvia + + + align:start position:0% +um by Sylvia +Nassar + + align:start position:0% +Nassar + + + align:start position:0% +Nassar +um so that's the story of uh Ora few + + align:start position:0% +um so that's the story of uh Ora few + + + align:start position:0% +um so that's the story of uh Ora few +words about John Nash and then the + + align:start position:0% +words about John Nash and then the + + + align:start position:0% +words about John Nash and then the +reason I mentioned it is that he the + + align:start position:0% +reason I mentioned it is that he the + + + align:start position:0% +reason I mentioned it is that he the +problem he + + align:start position:0% +problem he + + + align:start position:0% +problem he +studied + + align:start position:0% +studied + + + align:start position:0% +studied +was nerson + + align:start position:0% +was nerson + + + align:start position:0% +was nerson +games so if you have n + + align:start position:0% +games so if you have n + + + align:start position:0% +games so if you have n +people three people is enough trying + + align:start position:0% +people three people is enough trying + + + align:start position:0% +people three people is enough trying +to maximize + + align:start position:0% +to maximize + + + align:start position:0% +to maximize +their + + align:start position:0% +their + + + align:start position:0% +their +profits + + align:start position:0% +profits + + + align:start position:0% +profits +that's much much harder than linear + + align:start position:0% +that's much much harder than linear + + + align:start position:0% +that's much much harder than linear +programming uh because they can form + + align:start position:0% +programming uh because they can form + + + align:start position:0% +programming uh because they can form +coalitions you know any two could join + + align:start position:0% +coalitions you know any two could join + + + align:start position:0% +coalitions you know any two could join +up and say okay we'll we'll be a team + + align:start position:0% +up and say okay we'll we'll be a team + + + align:start position:0% +up and say okay we'll we'll be a team +but then if you if then it may after a + + align:start position:0% +but then if you if then it may after a + + + align:start position:0% +but then if you if then it may after a +little while a person says as they do in + + align:start position:0% +little while a person says as they do in + + + align:start position:0% +little while a person says as they do in +reality hey I'd be better off this other + + align:start position:0% +reality hey I'd be better off this other + + + align:start position:0% +reality hey I'd be better off this other +person will bribe me to join him and uh + + align:start position:0% +person will bribe me to join him and uh + + + align:start position:0% +person will bribe me to join him and uh +so Coalition changes and what's the best + + align:start position:0% +so Coalition changes and what's the best + + + align:start position:0% +so Coalition changes and what's the best +what's the optimal strategy it's so I + + align:start position:0% +what's the optimal strategy it's so I + + + align:start position:0% +what's the optimal strategy it's so I +could speak if you send me an email + + align:start position:0% +could speak if you send me an email + + + align:start position:0% +could speak if you send me an email +choose maybe two person games I couldn't + + align:start position:0% +choose maybe two person games I couldn't + + + align:start position:0% +choose maybe two person games I couldn't +do three person games uh next it's next + + align:start position:0% +do three person games uh next it's next + + + align:start position:0% +do three person games uh next it's next +Wednesday morning at 99: uh it's the + + align:start position:0% +Wednesday morning at 99: uh it's the + + + align:start position:0% +Wednesday morning at 99: uh it's the +final pair of lectures and uh if you're + + align:start position:0% +final pair of lectures and uh if you're + + + align:start position:0% +final pair of lectures and uh if you're +willing to stay one more minute can I + + align:start position:0% +willing to stay one more minute can I + + + align:start position:0% +willing to stay one more minute can I +tell you about a problem which maybe + + align:start position:0% +tell you about a problem which maybe + + + align:start position:0% +tell you about a problem which maybe +will be solved by next Wednesday but + + align:start position:0% +will be solved by next Wednesday but + + + align:start position:0% +will be solved by next Wednesday but +maybe not uh it's a commentator thing + + align:start position:0% +maybe not uh it's a commentator thing + + + align:start position:0% +maybe not uh it's a commentator thing +and and I'll just put it in the record + + align:start position:0% +and and I'll just put it in the record + + + align:start position:0% +and and I'll just put it in the record +even though I'm I don't know how this is + + align:start position:0% +even though I'm I don't know how this is + + + align:start position:0% +even though I'm I don't know how this is +going to come out so the question is I + + align:start position:0% +going to come out so the question is I + + + align:start position:0% +going to come out so the question is I +got into this in a discussion this week + + align:start position:0% +got into this in a discussion this week + + + align:start position:0% +got into this in a discussion this week +I'd like to know if I if I knew some + + align:start position:0% +I'd like to know if I if I knew some + + + align:start position:0% +I'd like to know if I if I knew some +entries in a + + align:start position:0% +entries in a + + + align:start position:0% +entries in a +matrix could I complete the rest of the + + align:start position:0% +matrix could I complete the rest of the + + + align:start position:0% +matrix could I complete the rest of the +entries say so that the Matrix had rank + + align:start position:0% +entries say so that the Matrix had rank + + + align:start position:0% +entries say so that the Matrix had rank +one so suppose I + + align:start position:0% +one so suppose I + + + align:start position:0% +one so suppose I +knew suppose I knew + + align:start position:0% +knew suppose I knew + + + align:start position:0% +knew suppose I knew +these oh let me make my life easy + + align:start position:0% +these oh let me make my life easy + + + align:start position:0% +these oh let me make my life easy +suppose I knew those entries in a matrix + + align:start position:0% +suppose I knew those entries in a matrix + + + align:start position:0% +suppose I knew those entries in a matrix +I let me say + + align:start position:0% +I let me say + + + align:start position:0% +I let me say +those suppose I know well let me yeah + + align:start position:0% +those suppose I know well let me yeah + + + align:start position:0% +those suppose I know well let me yeah +well let me let me put in another entry + + align:start position:0% +well let me let me put in another entry + + + align:start position:0% +well let me let me put in another entry +okay suppose I know those those say + + align:start position:0% +okay suppose I know those those say + + + align:start position:0% +okay suppose I know those those say +those six entries could be anything + + align:start position:0% +those six entries could be anything + + + align:start position:0% +those six entries could be anything +could I finish the other + + align:start position:0% +could I finish the other + + + align:start position:0% +could I finish the other +three so that the Matrix was rank + + align:start position:0% +three so that the Matrix was rank + + + align:start position:0% +three so that the Matrix was rank +one what does rank one mean means every + + align:start position:0% +one what does rank one mean means every + + + align:start position:0% +one what does rank one mean means every +row is a multiple of every other row it + + align:start position:0% +row is a multiple of every other row it + + + align:start position:0% +row is a multiple of every other row it +means every 2x two determinant is + + align:start position:0% + + + + align:start position:0% + +zero every 2x two determinant because + + align:start position:0% +zero every 2x two determinant because + + + align:start position:0% +zero every 2x two determinant because +typical rank one Matrix let's see let me + + align:start position:0% +typical rank one Matrix let's see let me + + + align:start position:0% +typical rank one Matrix let's see let me +draw just write down a typical rank one + + align:start position:0% +draw just write down a typical rank one + + + align:start position:0% +draw just write down a typical rank one +Matrix a 132 and then some multiple of + + align:start position:0% +Matrix a 132 and then some multiple of + + + align:start position:0% +Matrix a 132 and then some multiple of +that and then some other multiple of + + align:start position:0% +that and then some other multiple of + + + align:start position:0% +that and then some other multiple of +that say + + align:start position:0% +that say + + + align:start position:0% +that say +396 okay every row is a multiple of the + + align:start position:0% +396 okay every row is a multiple of the + + + align:start position:0% +396 okay every row is a multiple of the +same row every column is a multiple of + + align:start position:0% +same row every column is a multiple of + + + align:start position:0% +same row every column is a multiple of +the same column the rank is one and + + align:start position:0% +the same column the rank is one and + + + align:start position:0% +the same column the rank is one and +every 2x two determinant say 3 2 9 6 is + + align:start position:0% +every 2x two determinant say 3 2 9 6 is + + + align:start position:0% +every 2x two determinant say 3 2 9 6 is +18 - 18 + + align:start position:0% +18 - 18 + + + align:start position:0% +18 - 18 +every 2x two determinant has to be zero + + align:start position:0% +every 2x two determinant has to be zero + + + align:start position:0% +every 2x two determinant has to be zero +so if I give if if I'm if I'm given any + + align:start position:0% +so if I give if if I'm if I'm given any + + + align:start position:0% +so if I give if if I'm if I'm given any +six numbers here can I finish the + + align:start position:0% +six numbers here can I finish the + + + align:start position:0% +six numbers here can I finish the +remaining + + align:start position:0% +remaining + + + align:start position:0% +remaining +three to be rank one I don't think so + + align:start position:0% +three to be rank one I don't think so + + + align:start position:0% +three to be rank one I don't think so +why + + align:start position:0% + + + + align:start position:0% + +not this + + align:start position:0% +not this + + + align:start position:0% +not this +guy right right okay so this guy would + + align:start position:0% +guy right right okay so this guy would + + + align:start position:0% +guy right right okay so this guy would +be trouble right because he's the + + align:start position:0% +be trouble right because he's the + + + align:start position:0% +be trouble right because he's the +determined by making that 2 x two + + align:start position:0% +determined by making that 2 x two + + + align:start position:0% +determined by making that 2 x two +determinant and also by making this + + align:start position:0% +determinant and also by making this + + + align:start position:0% +determinant and also by making this +one + + align:start position:0% +one + + + align:start position:0% +one +oh last row get a 2 by DET oh here I've + + align:start position:0% +oh last row get a 2 by DET oh here I've + + + align:start position:0% +oh last row get a 2 by DET oh here I've +got a 2 by two determin oh yeah I'm + + align:start position:0% +got a 2 by two determin oh yeah I'm + + + align:start position:0% +got a 2 by two determin oh yeah I'm +already in trouble okay so let's take + + align:start position:0% +already in trouble okay so let's take + + + align:start position:0% +already in trouble okay so let's take +out this + + align:start position:0% +out this + + + align:start position:0% +out this +guy okay got to have other conditions + + align:start position:0% +guy okay got to have other conditions + + + align:start position:0% +guy okay got to have other conditions +about that that these aren't already + + align:start position:0% +about that that these aren't already + + + align:start position:0% +about that that these aren't already +part + + align:start position:0% +part + + + align:start position:0% +part +okay somehow right so now yeah so like + + align:start position:0% +okay somehow right so now yeah so like + + + align:start position:0% +okay somehow right so now yeah so like +our our marriage problem okay what about + + align:start position:0% +our our marriage problem okay what about + + + align:start position:0% +our our marriage problem okay what about +those five could I do it in that + + align:start position:0% +those five could I do it in that + + + align:start position:0% +those five could I do it in that +case + + align:start position:0% +case + + + align:start position:0% +case +and or not let me + + align:start position:0% + + + + align:start position:0% + +see many optim oh yeah I mean if so if I + + align:start position:0% +see many optim oh yeah I mean if so if I + + + align:start position:0% +see many optim oh yeah I mean if so if I +think of it big picture I'm given the + + align:start position:0% +think of it big picture I'm given the + + + align:start position:0% +think of it big picture I'm given the +first row yeah so then I take the second + + align:start position:0% +first row yeah so then I take the second + + + align:start position:0% +first row yeah so then I take the second +row the right multiple to make that come + + align:start position:0% +row the right multiple to make that come + + + align:start position:0% +row the right multiple to make that come +out right yeah and the third row to make + + align:start position:0% +out right yeah and the third row to make + + + align:start position:0% +out right yeah and the third row to make +that come out right or in terms of 2x + + align:start position:0% +that come out right or in terms of 2x + + + align:start position:0% +that come out right or in terms of 2x +two determinants which you can see I'm + + align:start position:0% +two determinants which you can see I'm + + + align:start position:0% +two determinants which you can see I'm +plugging away there's a little 2x two so + + align:start position:0% +plugging away there's a little 2x two so + + + align:start position:0% +plugging away there's a little 2x two so +that's determined there's a little 2 by + + align:start position:0% +that's determined there's a little 2 by + + + align:start position:0% +that's determined there's a little 2 by +two so that's determined then that's + + align:start position:0% +two so that's determined then that's + + + align:start position:0% +two so that's determined then that's +determined then that's determined once + + align:start position:0% +determined then that's determined once + + + align:start position:0% +determined then that's determined once +you deter that you still have problems + + align:start position:0% +you deter that you still have problems + + + align:start position:0% +you deter that you still have problems +with the first two entries in the First + + align:start position:0% +with the first two entries in the First + + + align:start position:0% +with the first two entries in the First +Column and the first two let's see uh + + align:start position:0% +Column and the first two let's see uh + + + align:start position:0% +Column and the first two let's see uh +should I erase these yellow ones + + align:start position:0% +should I erase these yellow ones + + + align:start position:0% +should I erase these yellow ones +and listen that the first the last one + + align:start position:0% +and listen that the first the last one + + + align:start position:0% +and listen that the first the last one +you eras + + align:start position:0% +you eras + + + align:start position:0% +you eras +you say that was + + align:start position:0% +you say that was + + + align:start position:0% +you say that was +deted row two column row two column 3 + + align:start position:0% +deted row two column row two column 3 + + + align:start position:0% +deted row two column row two column 3 +that seems determined by this one + + align:start position:0% + + + + align:start position:0% + +yeah has to satisfy two conditions but + + align:start position:0% +yeah has to satisfy two conditions but + + + align:start position:0% +yeah has to satisfy two conditions but +but it might luck out it might be that + + align:start position:0% +but it might luck out it might be that + + + align:start position:0% +but it might luck out it might be that +the number we needed in there was the + + align:start position:0% +the number we needed in there was the + + + align:start position:0% +the number we needed in there was the +number that yeah so I mean this is + + align:start position:0% +number that yeah so I mean this is + + + align:start position:0% +number that yeah so I mean this is +exactly the reasoning we went through we + + align:start position:0% +exactly the reasoning we went through we + + + align:start position:0% +exactly the reasoning we went through we +thought oh we're lost lost but then we + + align:start position:0% +thought oh we're lost lost but then we + + + align:start position:0% +thought oh we're lost lost but then we +recovered yeah so I think actually it + + align:start position:0% +recovered yeah so I think actually it + + + align:start position:0% +recovered yeah so I think actually it +would work I mean because it what we put + + align:start position:0% +would work I mean because it what we put + + + align:start position:0% +would work I mean because it what we put +in there made that a multiple of + + align:start position:0% + + + + align:start position:0% + +that and + + align:start position:0% +that and + + + align:start position:0% +that and +then it's got to + + align:start position:0% +then it's got to + + + align:start position:0% +then it's got to +satisfy two you're right the first + + align:start position:0% +satisfy two you're right the first + + + align:start position:0% +satisfy two you're right the first +square and the and the second square and + + align:start position:0% +square and the and the second square and + + + align:start position:0% +square and the and the second square and +I'm saying + + align:start position:0% +I'm saying + + + align:start position:0% +I'm saying +that when we put that number in to make + + align:start position:0% +that when we put that number in to make + + + align:start position:0% +that when we put that number in to make +this Square okay we put in the right + + align:start position:0% +this Square okay we put in the right + + + align:start position:0% +this Square okay we put in the right +number so that + + align:start position:0% +number so that + + + align:start position:0% +number so that +it'll it'll be it'll be kosher with both + + align:start position:0% +it'll it'll be it'll be kosher with both + + + align:start position:0% +it'll it'll be it'll be kosher with both +but you're absolutely right that's the + + align:start position:0% +but you're absolutely right that's the + + + align:start position:0% +but you're absolutely right that's the +right + + align:start position:0% +right + + + align:start position:0% +right +thinking so yeah so that number that we + + align:start position:0% +thinking so yeah so that number that we + + + align:start position:0% +thinking so yeah so that number that we +put in + + align:start position:0% +put in + + + align:start position:0% +put in +there made these two made these two + + align:start position:0% +there made these two made these two + + + align:start position:0% +there made these two made these two +little vectors in the same direction so + + align:start position:0% +little vectors in the same direction so + + + align:start position:0% +little vectors in the same direction so +that we can get a number in + + align:start position:0% +that we can get a number in + + + align:start position:0% +that we can get a number in +there + + align:start position:0% +there + + + align:start position:0% +there +yeah + + align:start position:0% + + + + align:start position:0% + +so so now you see the problem so how do + + align:start position:0% +so so now you see the problem so how do + + + align:start position:0% +so so now you see the problem so how do +you find what are the conditions under + + align:start position:0% +you find what are the conditions under + + + align:start position:0% +you find what are the conditions under +which you can do it or can't do it + + align:start position:0% +which you can do it or can't do it + + + align:start position:0% +which you can do it or can't do it +should I do one more + + align:start position:0% +should I do one more + + + align:start position:0% +should I do one more +example uh at least I the you're really + + align:start position:0% +example uh at least I the you're really + + + align:start position:0% +example uh at least I the you're really +seeing this just as it's being done so + + align:start position:0% +seeing this just as it's being done so + + + align:start position:0% +seeing this just as it's being done so +we don't know let's see well I better + + align:start position:0% +we don't know let's see well I better + + + align:start position:0% +we don't know let's see well I better +stay with + + align:start position:0% +stay with + + + align:start position:0% +stay with +3x3 I think I can't get six I can't + + align:start position:0% +3x3 I think I can't get six I can't + + + align:start position:0% +3x3 I think I can't get six I can't +specify six this is first step of my + + align:start position:0% +specify six this is first step of my + + + align:start position:0% +specify six this is first step of my +theorem + + align:start position:0% + + + + align:start position:0% + +have an undetermined one right but but + + align:start position:0% +have an undetermined one right but but + + + align:start position:0% +have an undetermined one right but but +now I think I can't here's let's see so + + align:start position:0% + + + + align:start position:0% + +here's okay there's six how many inde 2 + + align:start position:0% +here's okay there's six how many inde 2 + + + align:start position:0% +here's okay there's six how many inde 2 +by are well that's sort of the question + + align:start position:0% +by are well that's sort of the question + + + align:start position:0% +by are well that's sort of the question +yeah how many independent 2 by tws that + + align:start position:0% +yeah how many independent 2 by tws that + + + align:start position:0% +yeah how many independent 2 by tws that +that is maybe the question and I claim + + align:start position:0% +that is maybe the question and I claim + + + align:start position:0% +that is maybe the question and I claim +there aren't six I think that one I + + align:start position:0% +there aren't six I think that one I + + + align:start position:0% +there aren't six I think that one I +can't do but now tell me why oh maybe + + align:start position:0% +can't do but now tell me why oh maybe + + + align:start position:0% +can't do but now tell me why oh maybe +you can see why I + + align:start position:0% +you can see why I + + + align:start position:0% +you can see why I +can't + + align:start position:0% +can't + + + align:start position:0% +can't +why if you use your thinking now I'll + + align:start position:0% +why if you use your thinking now I'll + + + align:start position:0% +why if you use your thinking now I'll +I'll have to give + + align:start position:0% + + + + align:start position:0% + +in this guy is determined by this one + + align:start position:0% +in this guy is determined by this one + + + align:start position:0% +in this guy is determined by this one +but is there anybody fighting it right + + align:start position:0% +but is there anybody fighting it right + + + align:start position:0% +but is there anybody fighting it right +yes the + + align:start position:0% +yes the + + + align:start position:0% +yes the +last oh and these guys are fighting it + + align:start position:0% +last oh and these guys are fighting it + + + align:start position:0% +last oh and these guys are fighting it +and + + align:start position:0% +and + + + align:start position:0% +and +bottom as well well as this yeah okay + + align:start position:0% +bottom as well well as this yeah okay + + + align:start position:0% +bottom as well well as this yeah okay +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +so so at this point we conjecture we + + align:start position:0% +so so at this point we conjecture we + + + align:start position:0% +so so at this point we conjecture we +can't get six in there we can't specify + + align:start position:0% +can't get six in there we can't specify + + + align:start position:0% +can't get six in there we can't specify +six so that would be my guess I they + + align:start position:0% +six so that would be my guess I they + + + align:start position:0% +six so that would be my guess I they +couldn't couldn't specify + + align:start position:0% +couldn't couldn't specify + + + align:start position:0% +couldn't couldn't specify +six yeah this is this won't work but + + align:start position:0% +six yeah this is this won't work but + + + align:start position:0% +six yeah this is this won't work but +five could work but five won't + + align:start position:0% +five could work but five won't + + + align:start position:0% +five could work but five won't +necessarily work right you could give me + + align:start position:0% +necessarily work right you could give me + + + align:start position:0% +necessarily work right you could give me +five that where I couldn't do it + + align:start position:0% +five that where I couldn't do it + + + align:start position:0% +five that where I couldn't do it +right if I had a 2 by two in there it + + align:start position:0% +right if I had a 2 by two in there it + + + align:start position:0% +right if I had a 2 by two in there it +would fail so you see it's one of these + + align:start position:0% +would fail so you see it's one of these + + + align:start position:0% +would fail so you see it's one of these +cases where you where every size or the + + align:start position:0% +cases where you where every size or the + + + align:start position:0% +cases where you where every size or the +condition is that every size has to be + + align:start position:0% +condition is that every size has to be + + + align:start position:0% +condition is that every size has to be +okay so here's my theorem half proved + + align:start position:0% +okay so here's my theorem half proved + + + align:start position:0% +okay so here's my theorem half proved +that can be done marriage or whatever + + align:start position:0% +that can be done marriage or whatever + + + align:start position:0% +that can be done marriage or whatever +let's rank one as possible if um + + align:start position:0% +let's rank one as possible if um + + + align:start position:0% +let's rank one as possible if um +every uh K by K submatrix has less or + + align:start position:0% +every uh K by K submatrix has less or + + + align:start position:0% +every uh K by K submatrix has less or +equal to 2 K - one uh specified + + align:start position:0% + + + + align:start position:0% + +x's in other words when K was three and + + align:start position:0% +x's in other words when K was three and + + + align:start position:0% +x's in other words when K was three and +I was looking at the whole Matrix five + + align:start position:0% +I was looking at the whole Matrix five + + + align:start position:0% +I was looking at the whole Matrix five +was the maximum but then I also have to + + align:start position:0% +was the maximum but then I also have to + + + align:start position:0% +was the maximum but then I also have to +look at smaller matrices 2 by tws and be + + align:start position:0% +look at smaller matrices 2 by tws and be + + + align:start position:0% +look at smaller matrices 2 by tws and be +sure + + align:start position:0% +sure + + + align:start position:0% +sure +that I have less or equal three of + + align:start position:0% +that I have less or equal three of + + + align:start position:0% +that I have less or equal three of +those in any 2 by two I'm only allowed + + align:start position:0% +those in any 2 by two I'm only allowed + + + align:start position:0% +those in any 2 by two I'm only allowed +to specify three not all four + + align:start position:0% + + + + align:start position:0% + +so I'm I offer a prize I guess for the + + align:start position:0% +so I'm I offer a prize I guess for the + + + align:start position:0% +so I'm I offer a prize I guess for the +proof that so I can prove that this is + + align:start position:0% +proof that so I can prove that this is + + + align:start position:0% +proof that so I can prove that this is +required I can prove that in a k byk i + + align:start position:0% +required I can prove that in a k byk i + + + align:start position:0% +required I can prove that in a k byk i +can't fit in 2K of them it has to be + + align:start position:0% +can't fit in 2K of them it has to be + + + align:start position:0% +can't fit in 2K of them it has to be +less or equal 2K minus one so this would + + align:start position:0% +less or equal 2K minus one so this would + + + align:start position:0% +less or equal 2K minus one so this would +be an example I can't fit six in but + + align:start position:0% +be an example I can't fit six in but + + + align:start position:0% +be an example I can't fit six in but +five I can fit right that that would be + + align:start position:0% +five I can fit right that that would be + + + align:start position:0% +five I can fit right that that would be +no problem can can we just do that case + + align:start position:0% +no problem can can we just do that case + + + align:start position:0% +no problem can can we just do that case +doesn't mean any five would work but + + align:start position:0% +doesn't mean any five would work but + + + align:start position:0% +doesn't mean any five would work but +these five will work because there's no + + align:start position:0% +these five will work because there's no + + + align:start position:0% +these five will work because there's no +reason they shouldn't that's what that's + + align:start position:0% +reason they shouldn't that's what that's + + + align:start position:0% +reason they shouldn't that's what that's +what this Duality is it works if there's + + align:start position:0% +what this Duality is it works if there's + + + align:start position:0% +what this Duality is it works if there's +no reason why + + align:start position:0% +no reason why + + + align:start position:0% +no reason why +not do you see that that would + + align:start position:0% + + + + align:start position:0% + +work yes because well anyway you see it + + align:start position:0% +work yes because well anyway you see it + + + align:start position:0% +work yes because well anyway you see it +the these two these three would + + align:start position:0% +the these two these three would + + + align:start position:0% +the these two these three would +determine that these three would + + align:start position:0% +determine that these three would + + + align:start position:0% +determine that these three would +determine that these three would + + align:start position:0% +determine that these three would + + + align:start position:0% +determine that these three would +determine that these three would + + align:start position:0% +determine that these three would + + + align:start position:0% +determine that these three would +determine that and then true enough + + align:start position:0% +determine that and then true enough + + + align:start position:0% +determine that and then true enough +these would determine it but it we got a + + align:start position:0% +these would determine it but it we got a + + + align:start position:0% +these would determine it but it we got a +good chance and it well it just has to + + align:start position:0% +good chance and it well it just has to + + + align:start position:0% +good chance and it well it just has to +do + + align:start position:0% +do + + + align:start position:0% +do +there's to determined by + + align:start position:0% +there's to determined by + + + align:start position:0% +there's to determined by +one of given of of given ones yeah + + align:start position:0% +one of given of of given ones yeah + + + align:start position:0% +one of given of of given ones yeah +that's right that's right the condition + + align:start position:0% +that's right that's right the condition + + + align:start position:0% +that's right that's right the condition +because otherwise all the other are + + align:start position:0% +because otherwise all the other are + + + align:start position:0% +because otherwise all the other are +specified in terms how many yeah so how + + align:start position:0% +specified in terms how many yeah so how + + + align:start position:0% +specified in terms how many yeah so how +many does that give you you have K by K + + align:start position:0% +many does that give you you have K by K + + + align:start position:0% +many does that give you you have K by K +how + + align:start position:0% +how + + + align:start position:0% +how +many if I have a 10x10 + + align:start position:0% +many if I have a 10x10 + + + align:start position:0% +many if I have a 10x10 +Matrix the max maximum number I could + + align:start position:0% +Matrix the max maximum number I could + + + align:start position:0% +Matrix the max maximum number I could +specify would be + + align:start position:0% +specify would be + + + align:start position:0% +specify would be +19 but then those 19 that I specify I + + align:start position:0% +19 but then those 19 that I specify I + + + align:start position:0% +19 but then those 19 that I specify I +can't specify any 19 any 9 by9 Matrix in + + align:start position:0% +can't specify any 19 any 9 by9 Matrix in + + + align:start position:0% +can't specify any 19 any 9 by9 Matrix in +that Matrix can only have 17 of them and + + align:start position:0% +that Matrix can only have 17 of them and + + + align:start position:0% +that Matrix can only have 17 of them and +any 5x5 Matrix could only have nine of + + align:start position:0% +any 5x5 Matrix could only have nine of + + + align:start position:0% +any 5x5 Matrix could only have nine of +them and any 2x two Matrix could only + + align:start position:0% +them and any 2x two Matrix could only + + + align:start position:0% +them and any 2x two Matrix could only +have three of them otherwise I'd be dead + + align:start position:0% +have three of them otherwise I'd be dead + + + align:start position:0% +have three of them otherwise I'd be dead +at that lower level like the marriage + + align:start position:0% +at that lower level like the marriage + + + align:start position:0% +at that lower level like the marriage +problem it's where where that smaller + + align:start position:0% +problem it's where where that smaller + + + align:start position:0% +problem it's where where that smaller +set of + + align:start position:0% +set of + + + align:start position:0% +set of +or like the maximum cut problem where a + + align:start position:0% +or like the maximum cut problem where a + + + align:start position:0% +or like the maximum cut problem where a +small number smaller subset was was uh + + align:start position:0% +small number smaller subset was was uh + + + align:start position:0% +small number smaller subset was was uh +putting the limit + + align:start position:0% + + + + align:start position:0% + +on no if I think we had a case where + + align:start position:0% +on no if I think we had a case where + + + align:start position:0% +on no if I think we had a case where +there were no 2 by + + align:start position:0% +there were no 2 by + + + align:start position:0% +there were no 2 by +tws but that was a case with no no 2 x + + align:start position:0% +tws but that was a case with no no 2 x + + + align:start position:0% +tws but that was a case with no no 2 x +two screw-ups but a 3X3 screw + + align:start position:0% +two screw-ups but a 3X3 screw + + + align:start position:0% +two screw-ups but a 3X3 screw +up and so you have to check screw up at + + align:start position:0% +up and so you have to check screw up at + + + align:start position:0% +up and so you have to check screw up at +every size then the theorem is if you + + align:start position:0% +every size then the theorem is if you + + + align:start position:0% +every size then the theorem is if you +don't screw up at any size just in + + align:start position:0% +don't screw up at any size just in + + + align:start position:0% +don't screw up at any size just in +counting numbers then you can do it so + + align:start position:0% +counting numbers then you can do it so + + + align:start position:0% +counting numbers then you can do it so +what's the what's the question what's + + align:start position:0% +what's the what's the question what's + + + align:start position:0% +what's the what's the question what's +what the + + align:start position:0% +what the + + + align:start position:0% +what the +proof if if I could I don't know how to + + align:start position:0% +proof if if I could I don't know how to + + + align:start position:0% +proof if if I could I don't know how to +put in the X's right I don't know how to + + align:start position:0% +put in the X's right I don't know how to + + + align:start position:0% +put in the X's right I don't know how to +show yet anyway hopefully next Wednesday + + align:start position:0% +show yet anyway hopefully next Wednesday + + + align:start position:0% +show yet anyway hopefully next Wednesday +is the + + align:start position:0% +is the + + + align:start position:0% +is the +different situation that if that if all + + align:start position:0% +different situation that if that if all + + + align:start position:0% +different situation that if that if all +these if I don't have too many of any in + + align:start position:0% +these if I don't have too many of any in + + + align:start position:0% +these if I don't have too many of any in +any size submatrix then I can do + + align:start position:0% +any size submatrix then I can do + + + align:start position:0% +any size submatrix then I can do +it both of the examples you showed it + + align:start position:0% +it both of the examples you showed it + + + align:start position:0% +it both of the examples you showed it +was easier to verify you could do it + + align:start position:0% +was easier to verify you could do it + + + align:start position:0% +was easier to verify you could do it +true by looking at the rows as multiple + + align:start position:0% +true by looking at the rows as multiple + + + align:start position:0% +true by looking at the rows as multiple +of other rows that true but that was + + align:start position:0% +of other rows that true but that was + + + align:start position:0% +of other rows that true but that was +because those were little + + align:start position:0% + + + + align:start position:0% + +examples you're not believing my theorem + + align:start position:0% +examples you're not believing my theorem + + + align:start position:0% +examples you're not believing my theorem +right well that's the best way actually + + align:start position:0% +right well that's the best way actually + + + align:start position:0% +right well that's the best way actually +no no I + + align:start position:0% + + + + align:start position:0% + +I'm well yeah it's so it's like the + + align:start position:0% +I'm well yeah it's so it's like the + + + align:start position:0% +I'm well yeah it's so it's like the +marriage it's exactly like the marriage + + align:start position:0% +marriage it's exactly like the marriage + + + align:start position:0% +marriage it's exactly like the marriage +problem and that I have some condition + + align:start position:0% +problem and that I have some condition + + + align:start position:0% +problem and that I have some condition +which I hope is the right one that just + + align:start position:0% +which I hope is the right one that just + + + align:start position:0% +which I hope is the right one that just +involves a little + + align:start position:0% +involves a little + + + align:start position:0% +involves a little +counting and then the conclusion is that + + align:start position:0% +counting and then the conclusion is that + + + align:start position:0% +counting and then the conclusion is that +the whole thing can be completed the + + align:start position:0% +the whole thing can be completed the + + + align:start position:0% +the whole thing can be completed the +whole puzzle whole puzzle can be + + align:start position:0% +whole puzzle whole puzzle can be + + + align:start position:0% +whole puzzle whole puzzle can be +completed and uh + + align:start position:0% +completed and uh + + + align:start position:0% +completed and uh +it was + + align:start position:0% + + + + align:start position:0% + +exactly why is it different yeah I mean + + align:start position:0% +exactly why is it different yeah I mean + + + align:start position:0% +exactly why is it different yeah I mean +soor maybe it could + + align:start position:0% + + + + align:start position:0% + +be turned into the marriage problem I + + align:start position:0% +be turned into the marriage problem I + + + align:start position:0% +be turned into the marriage problem I +don't know I don't know how to do + + align:start position:0% +don't know I don't know how to do + + + align:start position:0% +don't know I don't know how to do +that I haven't actually I mean I + + align:start position:0% +that I haven't actually I mean I + + + align:start position:0% +that I haven't actually I mean I +realized right away that the condition + + align:start position:0% +realized right away that the condition + + + align:start position:0% +realized right away that the condition +we have is is a marriage + + align:start position:0% +we have is is a marriage + + + align:start position:0% +we have is is a marriage +likee marriage problem like matching + + align:start position:0% +likee marriage problem like matching + + + align:start position:0% +likee marriage problem like matching +like condition so there ought to be a + + align:start position:0% +like condition so there ought to be a + + + align:start position:0% +like condition so there ought to be a +way but I haven't seen it yet haven't + + align:start position:0% +way but I haven't seen it yet haven't + + + align:start position:0% +way but I haven't seen it yet haven't +had time to tell the truth I'm uh + + align:start position:0% +had time to tell the truth I'm uh + + + align:start position:0% +had time to tell the truth I'm uh +normally I wouldn't reveal half prooved + + align:start position:0% +normally I wouldn't reveal half prooved + + + align:start position:0% +normally I wouldn't reveal half prooved +theorem uh but + + align:start position:0% +theorem uh but + + + align:start position:0% +theorem uh but +uh it seemed appropriate here if I have + + align:start position:0% +uh it seemed appropriate here if I have + + + align:start position:0% +uh it seemed appropriate here if I have +a 2 by two Matrix in the upper corner + + align:start position:0% +a 2 by two Matrix in the upper corner + + + align:start position:0% +a 2 by two Matrix in the upper corner +doesn't have zero determinator AR a 2 by + + align:start position:0% +doesn't have zero determinator AR a 2 by + + + align:start position:0% +doesn't have zero determinator AR a 2 by +two Matrix that the upper the upper left + + align:start position:0% +two Matrix that the upper the upper left + + + align:start position:0% +two Matrix that the upper the upper left +hand corner 2 by two 2 by two you know I + + align:start position:0% +hand corner 2 by two 2 by two you know I + + + align:start position:0% +hand corner 2 by two 2 by two you know I +fill in + + align:start position:0% +fill in + + + align:start position:0% +fill in +the first two entries and the first two + + align:start position:0% +the first two entries and the first two + + + align:start position:0% +the first two entries and the first two +rows wait a minute how big is this it's + + align:start position:0% +rows wait a minute how big is this it's + + + align:start position:0% +rows wait a minute how big is this it's +a 3 by3 3 by3 okay four in the + + align:start position:0% +a 3 by3 3 by3 okay four in the + + + align:start position:0% +a 3 by3 3 by3 okay four in the +upper the upper left corner 3x3 put + + align:start position:0% +upper the upper left corner 3x3 put + + + align:start position:0% +upper the upper left corner 3x3 put +in sorry tell me where to put so you're + + align:start position:0% +in sorry tell me where to put so you're + + + align:start position:0% +in sorry tell me where to put so you're +specifying these yeah those four then + + align:start position:0% +specifying these yeah those four then + + + align:start position:0% +specifying these yeah those four then +you're dead yeah right okay okay I'm + + align:start position:0% +you're dead yeah right okay okay I'm + + + align:start position:0% +you're dead yeah right okay okay I'm +saying you're dead because there's a + + align:start position:0% +saying you're dead because there's a + + + align:start position:0% +saying you're dead because there's a +because there's a submatrix of size two + + align:start position:0% +because there's a submatrix of size two + + + align:start position:0% +because there's a submatrix of size two +with two + + align:start position:0% +with two + + + align:start position:0% +with two +with too many specified yeah right you + + align:start position:0% +with too many specified yeah right you + + + align:start position:0% +with too many specified yeah right you +need + + align:start position:0% +need + + + align:start position:0% +need +toy + + align:start position:0% +toy + + + align:start position:0% +toy +youy the by I mean in these cases in all + + align:start position:0% +youy the by I mean in these cases in all + + + align:start position:0% +youy the by I mean in these cases in all +the cases that we found two maor that + + align:start position:0% +the cases that we found two maor that + + + align:start position:0% +the cases that we found two maor that +specify the same point + + align:start position:0% +specify the same point + + + align:start position:0% +specify the same point +yes everybody is free to leave it's 10 + + align:start position:0% +yes everybody is free to leave it's 10 + + + align:start position:0% +yes everybody is free to leave it's 10 +to five now right uh uh yeah so let's + + align:start position:0% +to five now right uh uh yeah so let's + + + align:start position:0% +to five now right uh uh yeah so let's +let's come back to this hopefully with + + align:start position:0% +let's come back to this hopefully with + + + align:start position:0% +let's come back to this hopefully with +some new idea uh 9:00 Wednesday okay + + align:start position:0% +some new idea uh 9:00 Wednesday okay + + + align:start position:0% +some new idea uh 9:00 Wednesday okay +thanks oh that's answer actually \ No newline at end of file diff --git a/5qTCy2wTL_s.txt b/5qTCy2wTL_s.txt new file mode 100644 index 0000000000000000000000000000000000000000..36b5ef7f8a0b9ed014fee91a30bd62c6a066e1af --- /dev/null +++ b/5qTCy2wTL_s.txt @@ -0,0 +1,2831 @@ +The following content is +provided under a Creative + +Commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high quality educational +resources for free. + +To make a donation or view +additional materials from + +hundreds of MIT courses, visit +MIT OpenCourseWare at + +ocw.mit.edu. + +PROFESSOR: All right. + +It's 12:05, so why don't you +go ahead and take 10 more + +seconds on the clicker +question today. + +This is about the periodic +trends that we + +discussed on Wednesday. + +So specifically, what we're +asking here is as we go across + +the periodic table, we want to +consider which has the smaller + +ionization energy. + +All right. + +So, let's focus our attention +up here now, whether it's + +between aluminum or whether +it's between phosphorous. + +And I also wanted you to +identify why it's also + +important to understand why we +have these trends, not just to + +memorize the trend itself. + +So, it turns out that the +majority of you got the + +correct answer, which is +that it's aluminum. + +The reason it's aluminum is +because aluminum has a lower z + +effective, so it's not being +pulled in as tightly by the + +nucleus, and if it's not being +pulled in as tightly, you're + +going to have to put in less +energy in order to ionize it, + +so that's why it's actually +going to have the smaller + +ionization energy. + +So it looks like not too many +more than half of you got this + +correct, so make sure you can +look at your periodic table + +and figure out how to think +about ionization energy in + +terms of z effective, not just +in terms of memorizing what + +that trend is. + +All right, so we can go to +today's notes, and in terms of + +the notes, what we're going +to start with is finishing + +material that's going to be +relevant for exam 1, and I + +told you on Wednesday that +actually I'd give you some + +information today in terms of +what you need to do to prepare + +for exam 1. + +So you should have gotten two +handouts as you came in, and + +if you didn't, please raise your +hand and a TA will come + +to you and get you that +second handout. + +But the second one says "exam +instructions and logistics." + +So, if everyone can +pull that out. + +So this is going to tell you +pretty much everything you + +need to know in terms of getting +ready for the exam, + +which is next Wednesday. + +So when you go home today or +some time this weekend, make + +sure you read this +page in detail. + +I'm just going to go over a few +of the main points here. + +So, the first is that what we're +going over notes today + +and also on Monday, the exam +material ends at the end + +lecture notes from lecture 9. + +So that was Wednesday's class +-- not at the end of + +Wednesday's class, but at the +end of the lecture notes. + +So we're going to finish +up with those today. + +I'll be really, really clear +when we get through them, and + +that's where you can stop in +terms of studying for this. + +Also, on everything that was on +problem-sets 1 through 3. + +So, you turned in p-set 3 today, +but we'll have the + +answers posted for you this +afternoon, so you can start + +studying from p-set 3, even as +early as tonight, if you want + +to, because those answers +will be there for you. + +So, in terms of what it is that +you need to prepare and + +bring with you for the exam, you +need to bring your MIT ID, + +especially if you haven't been +showing up regularly to your + +recitations and you aren't 100% +sure if your TA knows + +exactly who you are, you need to +make sure you have your MIT + +ID with you. + +You can't take the exam unless +you're registered for the + +class, and we need to make +sure we can verify that. + +You also need to bring a +calculator, of course, because + +we'll be solving problems that +involve calculations. + +You can bring any calculator +you want, we don't actually + +have restrictions for calculator +types here, but + +what you can't do, is you can't +program any relevant + +chemical or information about +constants in there. + +It's OK to use certain +fundamental constants that + +come in a lot of calculators, +so there's nothing we can do + +about that. + +That's OK. + +If you're wondering what's OK +or what's not OK, it's very + +clearly written out in this +handout, so make sure you read + +through it, because it is your +responsibility to make sure + +that your calculator does +not have anything extra + +programmed in it. + +And if you have your calculator +all set up as you + +love and you don't want to +change it, then maybe you + +should just go and get an $8.00 +scientific calculator + +that doesn't have any of the +graphing functions, because + +you don't actually need them, so +that's a better option for + +you, you can do that as well. + +And I had mentioned several +times that you do not need to + +memorize the majority of the +equations and you don't need + +to memorize any physical +constants. + +So if you flip the info page +over on the back here, what + +you'll see is the periodic +table, this is the same one + +that I've handed out in the +last two lectures -- the + +periodic table without any +electron configurations. + +This is exactly the sheet here, +it's exactly what you'll + +get on exam day. + +You'll also see that they have +all the physical constants + +that you're going to need, and +also a bunch of the actual + +equations that we've been using +in the first couple + +weeks here. + +So you don't need to memorize +any of this, you're actually + +going to be handed this. + +There are a few equations that +you need to memorize -- those + +are the very simple -- very, +very simple equations, such as + +e equals h times nu -- hopefully +you don't have to + +sit down and try to memorize +that, hopefully we all know + +that already. + +But just to be really clear, +I've written out exactly which + +equations you do have to +memorize on the front here, so + +long as you know those, the +rest you can just look up. + +And in terms of using these +equations in solving problems + +on the exam, and also using +these constants, make sure if + +you think there might be any +chance you're going to get any + +little part of a problem wrong +or do a calculation + +inaccurately, you need to write +out every single step of + +your thinking as you write out +these problems. We can't give + +you any partial credit +whatsoever if we can't see + +your thought process. + +So it's important to write out +the equation you use, you need + +to write out the constants +that you use to + +fill in that equation. + +And that we need to see your +work to get full credit, and + +then especially if you get +things wrong, we need to know + +where it went wrong, because +we do try to give as much + +partial credit as possible in +these exams, since there are a + +lot of places where small +mistakes can result in the + +wrong answer. + +So also, along those lines in +terms of test taking, make + +sure you also box your answers +and that you keep track of + +significant figures and that you +also remember to include + +your units. + +These are just little things +that can add up, so you just + +want to make sure you're +on top of those. + +And your TAs on Tuesday are +going to share a lot of other + +types of sort of exam strategies +in thinking about + +how you can approach an exam +when we're in a time situation + +like we are, so they'll share +some of their experience with + +you in terms of taking +these timed exams. + +So, in terms of practicing this +weekend, I mentioned that + +instead of getting a problem-set +today, what I am + +going to be posting is optional +extra problems. So + +they're optional, but they're +very, very, very highly + +encouraged that you do these, +because this is going to give + +you practice for the types of +problems that are going to be + +on the exam. + +We're also posting a practice +exam for you to take, so after + +you're completely done your +studying, it's good to have + +everything done before you take +the practice exam, and + +then sit down just with this +sheet here and your + +calculator, and ideally a timer, +and make sure you can + +do the practice exam in the +allotted amount of time. + +So that way you can have an +idea if, oh, I do really + +understand this but I'm a little +bit slow, maybe I need + +to practice this one type of +problem a little bit longer so + +I can get up to speed so I'm +going to be able to get + +through all this in terms +of the exam time. + +All right. + +So let's move on to +today's topics. + +So, as I said, we're finishing +up with what we left off with + +yesterday -- or excuse +me, on Wednesday. + +This includes atomic radius and +the idea of isoelectronic + +atoms. So that's going to +be the end of the exam 1 + +material, and then we'll move +on to exam 2 material, which + +is kind of exciting, because +we've been talking about just + +individual atoms and ions up to +this point, and now we can + +talk about molecules, so +we're going to start + +talking about bonding. + +So for some you that are less +interested in maybe the + +physical structure of an +individual atom, now some more + +exciting material for you might +be coming up if you like + +to think about how, instead, +molecules behave, either + +within bonding, within +themselves, or with other + +molecules, that's what we're +going to be heading to + +in this next unit. + +So, we need to finish up +with periodic trends. + +And first, on your +lecture notes, I + +start with atomic radius. + +I was so proud of myself getting +the lecture notes + +finished early and handing them +in to CopyTech, and then + +I realized we didn't do + +electronegativity on Wednesday. + +So, if you can flip your lecture +notes over and just + +write on the blank space, +we're going to cover + +electronegativity first here, +and specifically, you can go + +back and fill this in to your +lecture 9 notes, if you want + +to stay organized, but I just +suggest just writing it on + +lecture 10 notes now +and going back. + +You can still keep organized, +which hopefully most of you + +like to do, and get it in the +right place in the notes. + +So, when we're talking about the +idea of electronegativity, + +essentially what we're talking +about is the ability for an + +atom to attract electron density +from another atom. + +So it's just a measure of how +much does one given atom want + +to pull away electron +density from, let's + +say, an adjacent atom. + +So it's actually very related +to what we're talking about + +when we said electron affinity, +and it's also + +related to ionization energy, +and we can call + +electronegativity by symbol +here, and it turns out that + +it's going to be proportional +to 1/2 of the electron + +affinity of a given atom, plus +the ionization energy. + +So, in other words, we +can just think of + +electronegativity as being the +average of that ionization + +energy and the electron +affinity. + +This should make sense, because +if an atom has a very + +high electron affinity, that +means it's really happy taking + +an electron from another atom, +or taking a free electron -- + +that that's very favorable. + +If something has a high +ionization energy, it means + +that it really, really, +really does not want + +to give up an electron. + +So you can think about how these +2 things combined are + +going to be electronegativity, +which is a measure of how much + +an atom wants to pull electron +density away + +from another atom. + +So, if we think about +electronegativity as a + +periodic trend, we can just draw +our nice periodic table + +here, and let's separate +it into quadrants. + +So if we think about the upper +right hand part of the + +quadrant, well, this is where +we're going to have high + +electron affinity and high +ionization energy, so we're + +also going to see high +electronegativity here. + +And in contrast, in the lower +left hand part of the periodic + +table, these 2 quantities are +low, so also what we're going + +to see is low electronegativity. + +And if we talk about what's +going on in areas, or with + +atoms that have high +electronegativity, and we + +think about whether they're +electron donors or electron + +acceptors, what would you expect +for an atom that has + +high electronegativity? + +Is it going to be an electron +donor or acceptor? + +Great. + +Yup, it's going to be an +electron acceptor, it wants to + +accept electrons, it wants to +accept electron density. + +So, in contrast, if it has a +low electronegativity, this + +then is going to be +an electron donor. + +All right, so it's very +common to talk about + +electronegativity of different +atoms, and you can look up + +tables of these. + +Often what you'll see is not +a table based on this + +definition, but something that's +called the Pauling + +definition of electronegativity, +but it's + +exactly the same idea and the +same trend as this more + +numerical way to think about +what the meaning of + +electronegativity is. + +All right, so now we can move +on to the start of today's + +notes, which is atomic radius. + +So this, in fact, is going to +be our last principle that + +we're going to talk about in +terms of periodic trends. + +So this is actually the most +straightforward, so sometimes + +it's nice to end with the +easiest concept, and that's + +what we're doing here. + +And if we're talking about +atomic radius, essentially + +we're talking about +atomic size. + +And immediately it should +probably come into your head + +that we don't actually have an +atomic radius that we can talk + +about, right? + +What I just spent many lectures +discussing is the + +fact that we can not know how +far away an electron is from + +the nucleus, so we can't +actually know the radius of a + +certain atom. + +And that's true. + +An atom's not a defined +sphere, for example. + +We can't define it as an exact +radius in terms of the + +definition we might think +of classically. + +So, keep that in mind when we're +talking about atomic + +radius, I'm not suddenly +changing my story and saying, + +yes, we do have a +distinct radius. + +Instead, what people have done +is come up with different ways + +to think about how they +can define a radius. + +And one common way to think +about it, is to think about + +the value of r, or the radius, +below which 90% of that + +electron density is going +to be contained. + +So we're not saying it's +all the electron + +density, it's just 90%. + +Because we know as we go to +infinity, even though the + +density gets smaller and smaller +and smaller, we still + +have electron density very far +away from the nucleus. + +So, what we're going to define +is just let's just capture 90% + +of that electron density. + +So, that's one way to think +about it, and there's also + +another way, and this +is the way that your + +book presents it. + +If you, in fact, have two of +the same atom right next to + +each other, let's say you have a +crystal, or let's say you're + +talking about a metal, what you +can do is just look at the + +distance between the two nuclei, +and split that in 1/2, + +and take the atomic +radius that way. + +So, these are two different +definitions of how to think + +about atomic radius, but really +what you find when + +these are measured is they +come up with almost the + +identical values, so there are +tables you can look up of + +atomic radii and see these +values, and you can trust them + +that, yes, they work for both +this definition and for this + +definition here, +in most cases. + +And what we've been talking +about with all of these + +properties are, of course, how +can we figure out what that is + +for a certain atom by looking +at the periodic table, so we + +want to think about +the periodic + +trend for atomic radius. + +And we know as we go across a +row in the periodic table, + +what's happening is that z +effective or the effective + +pull on the nucleus +is increasing. + +So would you expect, therefore, +as we go across a + +row for the atomic radius, to +increase or to decrease? + +Good. + +OK, yes. + +We are expecting to see that +it decreases because it's + +feeling a stronger pull, all the +electrons are being pulled + +in closer to the nucleus, so +that atomic size is going to + +get smaller. + +This is in contrast to what's +happening as we go down a + +periodic table. + +So as we go down we're now +adding electrons to further + +and further away shells, so +what we're going to see is + +that the atomic radius is going +to increase as we're + +going down the periodic table. + +And we can look at +an example here. + +If we start in the upper left +hand corner of the periodic + +table with lithium, you can +see that as we go down the + +table, what you're seeing is +that that atomic radius is + +actually increasing, +as we would expect. + +Whereas, if we go across a row, +what we see is that the + +atomic radius is decreasing. + +So, again, this is one of the +more straightforward trends. + +You just need to remember +what's happening to z + +effective, which really tells +us what's happening with all + +the trends, and once you know +z effective, you can figure + +out, for example, what direction +the atomic radius + +should be going into. + +So, that's it for +periodic trends. + +We have talked about four +different ones. + +We talked about ionization +energy, electron affinity, we + +talked about electronegativity, +which is + +just kind of a combination of +the first two, and then ended + +with atomic radius here. + +And what you might have noted +is although we described how + +to make predictions about these +properties, I didn't + +talk too much about what it +actually means, what the + +ramifications of these different +properties are. + +And the reason we didn't do that +is because we're actually + +going to spend much of the rest +of the course relating + +these different properties to +the properties of molecules in + +terms of bonding, and also in +terms of chemical reactions. + +So, for example, if we have a +very electronegative atom + +within a certain molecule, what +you'll actually find is + +that it does affect how the +molecule is going to take part + +in different chemical or +biological reactions. + +And this will become more and +more clear as we actually talk + +about these reactions and +talk about bonding. + +But you need to be able to +predict what kind of + +properties a certain atom's +going to have within a + +molecule, whether you're talking +about something, for + +example, that's very +electronegative, or something + +that is not electronegative at +all, it is going to make a + +difference in terms of thinking +about how molecules + +are structured and +also how they + +interact with other molecules. + +However, I can give you at least +one example while we're + +still on just talking about +atoms. So we haven't gotten to + +molecules yet, we're just +talking about single atoms or + +single ions, but what's nice +is just talking about this + +very straightforward principle +of atomic radius. + +We can already use that in terms +of single ions to think + +about a really complex +biological issue, which is to + +talk about ion channels. + +So, that is just a quick example +for some of you, you + +might be very familiar with ion +channels, others might not + +know what these are, so I'll +just tell you quite briefly + +that ion channels are +these very massive + +transmembrane proteins. + +Essentially, what they are is +it's a protein that spans the + +membrane of a cell. + +And what they do is they +regulate the influx of ions + +across that cell. + +So the influx of ions from the +outside of the cell to the + +inside of the cell, +for example. + +And you can think of ion +channels as being gated, by + +gated it means the gate can be +closed and no ions are going + +through, as in this case here. + +Or you can talk about the gate +being open, and in this case, + +you can see that you will +have an influx of ions. + +So, ion channels are important +for maintaining a voltage + +difference between the inside of +the cell and outside of the + +cell, and they're found in all +sorts of cell types in your + +body, but if you think about +where they're most prevalent, + +it turns out that they're most +prevalent in muscle cells and + +also in nerve cells, +so in your neurons. + +And essentially, what they do +in neurons is they underlie + +those nerve impulses, or those, +essentially what we + +call electrical signaling +between neurons -- you might + +also call that the action +potential of the neurons. + +So essentially, they regulate +this action potential, and + +they do so by helping to +establish and then control the + +voltage gradient within the +cells. so, essentially, + +they're establishing or +controlling or changing the + +difference between the charge +inside the cell and the charge + +outside cell. + +And when we talk about any type +of ion channel, there are + +just tons of different kinds of +ion channels, and you can + +characterize them in a +few different ways. + +So, for example, you could +characterize them in terms of + +how they're gated, and basically +how they open or + +close -- that's one way to talk +about different types. + +Another way to talk about +different types is to think + +about which ion they're +selected for. + +And all ion channels are +selective for a single type of + +ion, and we can think about +how that selectivity takes + +place, and that's where this +idea of atomic radius is going + +to become very important. + +So, for example, if we look at +sodium channels, and sodium + +channels are some of the +particularly prevalent ones + +when we're talking about +neurons, if you think about + +the cell membrane, and this +little green cartoon is me + +trying to show a sodium channel +here, and in this + +case, you can see that it's +closed, such that no ions are + +getting through. + +However, when that gate is +opened, the sodium channel is + +now going to be incredibly +selective and only let through + +sodium ions and no other +type of ion. + +And this is really interesting +to think about because you can + +imagine in our body we have +concentrations of all types of + +ions, and specifically, some +seem very, very similar to + +each other. + +So we could think about +comparing the potassium ion to + +a sodium ion. + +They have the same charge +of plus one. + +The only thing that's different +is that they're one + +down on the periodic table, +potassium is down one row, so + +it's going to be a little +bigger, but when we're + +thinking about size, it maybe +does not seem that significant + +to talk about the size. + +But what we find out +is that it is. + +So, what happens, this is +another view of a sodium + +channel, so this is actually +looking a little bit more at + +the protein structure. + +What all of these channels +have is what's called a + +selectivity filter, so this +filter filters out the type of + +ion that's going to be +allowed through. + +And there's two parts +of the filter. + +First we need to select +for actual charge. + +So the way that it does this +is the filter is actually + +lined with all of this negative +charge, and for those + +of you that are more into +biology or biochemistry, + +that's because of negatively +charged amino acid residues, + +but all you need to think about +is that it has negative + +charge in the inside of this +pore, and what happens then is + +that if something has a positive +charge, it's going to + +be stabilized to enter this +pore, whereas any negative + +ions are going to be repelled. + +So that's the first step in +being selective, but now how + +do we differentiate between +these sodium + +and potassium ions. + +And the answer is just really +beautifully simple, and it's + +just that the pore gets really, +really tiny, to the + +point that it gets so small that +all that can fit through + +this pore is one a single ion, +one single sodium ion, + +solvated by one single +water molecule. + +And that's all that's big enough +to pass through or + +small enough to pass through. + +And if we go up even just one +row on the periodic table to + +potassium, what we actually see +is now that it's going to + +be too large, and, in fact, a +potassium solvated with one + +water molecule won't go +through our channel. + +So, this is just one example +of how these properties can + +already, even our understanding +just talking + +about single atoms, can already +make an impact in + +these biological systems. And +actually, a question that + +might come up, I just explained, +the sodium channel, + +you might say, well, how do +potassium channels work then, + +because I can understand how you +can filter something big + +out, but how do you filter +out something small. + +And it turns out that size +exclusion is also the + +principle that's in play with +potassium channels as well, + +but in this case it's a little +more complex, because what + +happens is these negative +residues the are in the pore + +need to stabilize the potassium +as it goes through, + +and the potassium is large +enough to make all the + +contacts it needs, but the +sodium, which you can picture + +being smaller, actually can't +reach all of the stabilizing + +charges that it needs to to +get through the pore. + +So, again, it is based on size, +it's a little bit less + +intuitive than the idea of just +straining out all of the + +potassium ions. + +But again, many of these ion +channels have this size + +exclusion pore, it's a very +important part of them. + +All right, so that was a quick +aside on thinking about how + +these properties can, +in fact, relate to + +something in our body. + +Let's move on to the last topic +in terms of this first + +exam, which is thinking about +the idea of isoelectronic + +atoms, or isoelectronic ions. + +And isoelectronic is very +straightforward, it just means + +having the same electron +configuration. + +The easiest way to look at this +is just to do an example. + +So let's take the +example of neon. + +This has the electron +configuration of 1 s 2, 2 + +s 2, and 2 p 6. + +It looks like we're cut off the +screen a little bit here, + +but you can see I've just +circled it there. + +So we can go ahead and think +about, well, are there any + +other atoms that are going +to have the same electron + +configuration? + +The answer to that is definitely +no -- if they had + +the same electron configuration, +they would, in + +fact, be neon. + +But we can think about different +ions that have this + +electron configuration. + +So for example, if we think +about fluorine, that has an + +electron configuration of 1 s +2, 2 s 2, 2 p 5, so all we + +would need to do is add one more +electron to get the same + +configuration as for neon. + +So if we want to write out what +that would be, it would + +just be to say that f minus is +isoelectronic with neon. + +So, we can say that -- if we +have neon here and we want to + +think about what's +isoelectronic, f minus would + +be isoelectronic. + +We also have oxygen -- what +would the charge on oxygen be? + +Um-hmm, right. + +2 minus. + +Then also, nitrogen, 3 minus -- +these are all going to be + +isoelectronic with neon. + +We can go in the other +direction, so let's go to + +sodium, but we would need to +take away an electron to make + +it isoelectronic. + +So we would say sodium plus, +or magnesium 2 plus, we can + +just keep going -- aluminum 3 +plus, silicone 4 plus, and we + +can go on and on in either +direction all the way across + +and down the periodic table. + +So, that's the idea of +isoelectronic ions. + +These are all isoelectronic, +they all have the same + +electron configuration. + +And we can also think +about going back to + +atomic size for a second. + +What the relationship is between +these ions and their + +parent atoms. So, for example, +if we think of the fluorine + +minus case, would you expect +fluorine minus to be larger or + +smaller than neutral fluorine? + +Okay. + +I heard mostly larger, but a +little bit of a mix in there, + +and it turns out that +larger is correct. + +And we can think about why -- +essentially we have fluorine + +and now we're adding +another electron. + +So you can picture that fluorine +is going to get + +larger in this case. + +And that would be true +for all of the + +negatively charged ions. + +So, by the same logic, that +means that all of our + +positively charged ions are, in +fact, going to be smaller + +in terms of radius, compared +to their neutral parents. + +Not only are we taking away an +electron here, but we're also + +going to decrease shielding, +so the electrons that are + +already in there are going to +feel a higher z effective and + +will be pulling and the atom +will be getting smaller. + +And this is just a picture +showing some of these sizes + +with their parent. + +So, for example, a lithium here, +you can see how lithium + +plus is smaller than the actual +lithium atom in its + +neutral state. + +Whereas for fluorine, fluorine +is smaller than f minus is the + +one that's the outer +shell shown here. + +So, let's do a clicker question +on isoelectronic + +atoms. And now we're asking you +to look at krypton, so the + +atomic mass is 36. + +You can actually just grab +that handout, the second + +handout on the exam and look at +the periodic table there. + +So, which of the following ions +listed is isoelectronic + +with krypton? + +OK, let's take 10 +seconds on that. + +OK, good. + +This might be our all-time +high, 89% got this right. + +This is great. + +So, selenium 2 minus is what's +going to be isoelectronic, + +because if you add two electrons +to selenium, you'll + +get the same electron +configuration that you have + +for krypton here. + +OK, I think we can safely +go back to notes. + +So, I said I would announce +it, that's the + +end of exam 1 material. + +So, if you compartmentalize +things in your brain in + +certain ways, put that off into +the end of the exam 1 + +part of your brain, and +now we're going to + +move on to exam 2. + +Remember, for exam 2, you +still need to know and + +understand everything you +learned in exam 1, but you can + +put off learning it completely +until we get through, at + +least, next Wednesday before we +start maybe spending time + +on these concepts outside +of class. + +So, we're going to start with +talking about bonding, and any + +time we have a chemical bond, +basically what we're talking + +about is having two atoms where +the arrangement of their + +nuclei and they're electrons are +such that the bonded atoms + +results in a lower energy than +for the separate atoms. So we + +know we always want to have +our systems in as low an + +energy as possible, so it makes +sense that a bond would + +happen any time we got a lower +energy when we combine two + +atoms, versus when we +keep them separate. + +So specifically, today +we're going to talk + +about covalent bonds. + +A covalent bond is any time we +have a pair of electrons that + +is shared between two different +atoms. And the key + +word for covalent bonds is +the idea of being shared. + +The two electrons, for example, +we see in the h 2 + +molecule, they don't belong to +one or the other atom, they're + +actually shared. + +And what we'll see later, is +that the sharing is not always + +equal -- in the case +of h 2, it is + +completely equal sharing. + +In some cases, because of things +like electronegativity, + +one atom will take away more of +the electron density than + +the other atom, but they're +still shared, even if they're + +not always evenly shared. + +So, in talking about covalent +bonds, we should be able to + +still apply a more general +definition of a chemical bond, + +which should tell us that the +h 2 molecule is going to be + +lower in energy than if we +looked at 2 separate hydrogen + +atom molecules. + +So, let's see if that's +actually the case. + +So if I tell you that the energy +for single hydrogen + +atom is negative 13 12 +kilojoules per mole. + +If we want to talk about two +hydrogen atoms, then we just + +need to double that, so that's +going to be negative 2 6 2 4 + +kilojoules per mole that we're +talking about in terms of a + +single hydrogen atom. + +So, let's compare this to the +energy of the h 2 molecule, + +and we find that that's +negative 3,048 + +kilojoules per mole. + +So, in fact, yes, we did confirm +that these covalent + +bond, at least in the case of +hydrogen, we have confirmed by + +the numbers that we are at a +lower energy state when we + +talk about the bonded atom +versus the individual atom. + +And when we talk about covalent +bonds, there's 2 + +properties that we'll mostly +focus on, and that's going to + +be thinking about the bond +strength or the energy by + +which it stabilized +when it bonds. + +And we can also talk about the +bond length, so we might be + +interested in what the bond +length is, what the distance + +between these two nuclei are. + +And we can actually better +visualize this if we plot how + +that energy changes +as a function of + +internuclear distance. + +And when I say internuclear +distance, we actually call + +this r here. + +It's kind of ironic that we put +this in the same lecture + +as we talk about atomic radii, +which we also call r, but + +they're two different r's, +so you need to keep them + +separated in terms of what +you're talking about. + +When we're talking about r for +internuclear distance, we're + +talking about the distance +between two different nuclei + +in a bond, in a covalent bond. + +So, if we look at this graph +where what we're charting is + +the internuclear distance, so +the distance between these two + +hydrogen atoms, as a function +of energy, what we are going + +to see is a curve that looks +like this -- this is the + +general curve that you'll see +for any covalent bond, and + +we'll explain where that +comes from in a minute. + +I want to point out that the +zero energy is defined as when + +you have a naked proton where +the electron has popped out -- + +that's what we've defined as +zero energy up to this point + +when we're talking about single +atoms. So, for starters + +we'll keep that as our zero +energy, we're going to change + +it soon to make something that +makes more sense in terms of + +bonding, but we'll keep +that as zero for now. + +So, we see that the two h atoms +separate have a certain + +energy that's lower than +when the electron's + +not with the atom. + +And then even lower +down, we have our + +bonded hydrogen molecule. + +So, we can think about the +different kinds of + +interactions that are +taking place. + +I said what hold the bonds +together, what holds two atoms + +together is the attractive force +we have between each + +electron and the +other nucleus. + +That's the huge force that we're +talking about in terms + +of making a bond stable, but +there are also repulsive + +forces, so you can imagine +we're going to have + +electron-electron repulsion +between the two electrons if + +we're bringing them +closer together. + +And the real killer is if we get +too close we're even going + +to have nuclear-nuclear +repulsion between the nuclei + +of the two atoms. + +So, this makes this chart shown +in pink make a lot more + +sense, because if we're way +out at very far distances, + +essentially what we have here +is we're talking about two + +separate atoms. They're not +interacting at all so that's + +why the energy is the same as +that for two individual atoms, + +that's what we're +dealing with. + +As we get closer together, +we start get lower + +and lower in energy. + +The reason is because the +predominant force at this + +point is going to be the +attraction that's being felt + +between the nuclei and the +electrons in each of the + +atoms. At some point you're +going to hit a well here, + +which is the point where it's +most stabilized or at it's + +lowest energy. + +So, when we think about a bond +length, this is going to be + +the length of our bond here, +that makes sense because it's + +going to want to be at +that distance that + +minimizes the energy. + +But as we keep getting closer, +even though as we get closer, + +the attraction is going to get +stronger between the two + +nuclei and the electrons. + +We're also going to start to +have the repulsive forces + +become more prominent here, and, +in fact, they take over + +at some point, becoming the more +prevalent of the forces, + +so as you get closer, the +electron-electron repulsions, + +and eventually the +nucleus-nucleus repulsion is + +going to mean that your energy +is just absolutely + +skyrocketing, so it just keeps +going up and up as you get + +closer to zero here. + +So, when we want to talk about +the information that we can + +get out of looking at a chart +like this, well, the first + +thing I did tell you was that +this is going to be the bond + +length, so the distance r where +the energy is lowest, + +but we can also talk about +something called dissociation + +energy, that's going to be this +distance right here or + +the energy that is this value. + +And the dissociation energy is +very intuitive in terms of + +what it means, it means how much +energy you need to put + +into the molecule in order to +disassociate it into its + +individual atoms. And so we can +actually think about how + +do we calculate what the +dissociation energy should be + +for h 2, so let's go +ahead and do this. + +So, if we talk about +dissociating h 2, we're going + +from the h 2 molecule, and +breaking this bond right in + +half, so we now have +two individual + +hydrogen atoms here. + +So we need to take the energy +for the two atoms, which we + +know is -- so let's take our +dissociation energy is going + +to be equal to negative 2 6 2 4 +kilojoules per mole, and we + +want to subtract the energy of +the hydrogen molecule itself, + +so that's going to be negative +3 0 4 8 kilojoules per mole. + +So, what we get for the +disassociation energy for a + +hydrogen atom is 424 kilojoules +per mole. + +So what that means is that's how +much energy we would have + +to put in to a hydrogen molecule +in order to get it to + +split apart into +its two atoms. + +So, another way to talk about +dissociation energy is simply + +to call it bond strength, it's +the same thing, they're equal + +to each other. + +If we know that this is it the +dissociation energy for a + +hydrogen atom, we can also say +the bond strength for hydrogen + +molecule is 424. + +So, there's actually another way +to graph it where we can + +directly graph the dissociation +energy or the + +bond strengths. + +So I said before when we were +talking about single atoms, we + +always define the zero energy +as when an electron was + +actually ejected, but now, when +we talk about chemical + +reactions taking place, it's +very, very rare that we're + +actually going to be talking +about anything that gets to + +this point here. + +It's much more relevant to set +our zero point energy as the + +separation of a bond in terms of +talking about the reactions + +that we'll usually be +dealing with here. + +So, let's change our graph where +we now have this zero + +point set as the two individuals +hydrogen atoms, + +and then we see that our h 2 +molecule is at the negative of + +the dissociation energy, or the +negative what that bond + +strength is. + +So we know what that number +would be, it would be negative + +424 kilojoules per mole +that we see here. + +So, what this let's us do now +is directly compare, for + +example, the strength of a bond +in terms of a hydrogen + +atom and hydrogen molecule, +compared to any kind of + +molecule that we want to +graph on top of it. + +So, let's, for example, +look at nitrogen. + +So n 2, we can do the chart +here in green, so it's the + +green dotted line, and what +we see is that we have now + +defined this energy +as where the 2 + +nitrogen atoms are separated. + +So what we can actually directly +compare is the + +dissociation energy or the +bond strength of nitrogen + +versus hydrogen. + +So, if we think about this, +which would you say has a + +stronger bond? + +Is it going to be hydrogen +or nitrogen? + +Yup, it's going to +be nitrogen. + +And the reason we can see that +by looking at this graph is + +that we see that nitrogen when +it's bonded is in an even + +lower well than we +saw for hydrogen. + +It's going to be a stronger +bond because it's more + +stabilized when it when it comes +together as a molecule. + +We can also think about the +distance, the bond distance. + +So, which would you +say is going to be + +shorter in this case? + +Is a hydrogen bond shorter, or +is a nitrogen-nitrogen triple + +bond going to be shorter? + +Um-hmm, again, we can +get this information + +directly from our graph. + +We see that the radius is +shorter, so that means that + +the nitrogen-nitrogen bond +is going to be shorter. + +We can know this information +even if we just knew that the + +bond was stronger, we wouldn't +need to look at a graph here, + +because it turns out that if you +have a stronger bond, that + +also means that you have a +shorter bond -- those ywo are + +correlated. + +And something that we'll see +later on is that triple bonds, + +for example, are going to be +stronger than a corresponding + +double bond or a corresponding +single bond. + +So, if we talked about a +nitrogen-nitrogen single + +versus double versus triple +bond, the triple bond will be + +the shortest and it will +be the strongest. + +So, that's basically the idea +of how we are going to be + +thinking about covalent bonds. + +It's also important, once we +start talking about molecules, + +to have a way to represent them, +and also to be able to + +look at a shorthand notation +for a certain molecule and + +understand what the bond is. + +So, for example, down here I +wrote that it was n 2 and that + +it was h 2, but when I re-wrote +the molecules up + +here, you saw that it's an h +h single bond where it's a + +nitrogen-nitrogen triple bond. + +So any chemist should be able +to just look at n 2 and know + +that it's a triple bond, but +that's not something that + +we've learned how did to do +yet, so let's go ahead and + +start a new topic that's going +to allow us to have some sort + +of sense of what the valence +electron configuration, which + +includes whether something's a +single or double or a triple + +bond can be figured out for +any given molecule. + +So, to do this, what I'm going +to do is introduce the topic + +of Lewis structures. + +We're going to really get into +this next class, but I just + +want to introduce it to you to +give us a start, and many of + +you have used Lewis structures +in high school, but we'll be + +doing some much more challenging +Lewis structures, + +I can assure you, in +this class here. + +So, a Lewis structure is +basically an organizing + +property of bonding, of +molecules, which is the idea + +that when we're thinking about +bonding, the key is to achieve + +a full valence shell in each of +the individual atoms. So we + +want to have in an h h bond, for +example, a full shell for + +each of the hydrogen atoms. +And G.N. Lewis is the + +scientist that is credited, and +who did, in fact, come up + +with this idea for the way to +represent this, so the other + +parts of this idea, another way +to phrase it is that the + +electrons are going to be +distributed in such a way that + +we have what are called full +octets for each of the atoms, + +and basically that's the same +thing as saying we have a full + +valence shell, and this is +something that Lewis was able + +to recognize very, very early, +way before we had quantum + +mechanics to describe what these +orbitals were, but it + +makes sense a full valence shell +means for most atoms + +that we have a full s orbital +plus a full p orbital, so + +we're going to have a total of +four orbitals that are each + +filled with eight electrons, so +that's why we see that we + +need an octet here. + +And the idea is that when you do +these Lewis dot structures, + +we're representing electrons +with dots, which we'll see in + +a minute, and each +dot is going to + +represent a valence electron. + +So, hopefully, you remember +what we mean by valence + +electrons versus +core electrons. + +Core electrons are all those +electrons held in really tight + +with the nucleus in the inner +shells, whereas the valence + +electrons are only those +electrons that are in the + +outer-most shell, or at your +highest value of n of the + +principal quantum number. + +So, Lewis structures are really +a model for a way to + +think about what the valence +electron configuration is, and + +as I said, it's not based on +quantum mechanics, it's + +something that Lewis observed +far, far before quantum + +mechanics were discovered. + +So he came up with the ideas +that led to the idea of Lewis + +structures in the very +early 1900's. + +So you might ask well, why are +we using this model if it + +clearly doesn't take into +account quantum mechanics? + +And the reason that we use it +is that it is incredibly + +accurate, and allows us to very, +very quickly predict and + +to predict accurately, in most +cases, what the electron + +configuration of molecules +are going to be. + +So this is really useful. + +We don't always want to go +and solve the Schrodinger + +equation, and in fact, once we +start talking about molecules, + +I can imagine none of you, as +much as you love math or + +physics, want to be trying +to solve this Schrodinger + +equation in that case either. + +So, what Lewis structures allow +us to do is over 90% of + +the time be correct in terms +of figuring out what the + +electron configuration is. + +And we won't just use +them in this class. + +If you actually go to any of the +chemistry labs at MIT, if + +you go over to building 18 and +look in the organic labs where + +they're synthesizing new +molecules or making up new + +reactions, what you'll see if +you open anyone's notebook, + +their lab notebook, assuming +they keep a nice lab notebook, + +is that they will have Lewis +structures drawn in there that + +explain the reactions that +they're going to be + +doing for that day. + +And I mean this means way past +all the chemistry they've + +taken, they're now graduate +students or they're now + +professors, and they're still +writing out Lewis structures. + +Now they're writing a more +abbreviated form, which you'll + +probably get to if you take +organic chemistry, but really + +it's the exact same idea. + +And this goes all the +way back to 1902. + +In fact, Lewis was an American +scientist, so he was trained + +in America, and he actually was +a professor here at MIT + +from 1905 all the way to about +1911 or 1912, and these are + +some notes from 1902, and you +can't see them very well, but + +this was essentially an early +form of Lewis structures, and + +this was called the +cubicle atom. + +So, basically what he's showing +in these cubes is that + +there are eight spaces that +need to be filled up + +to have a full cube. + +So in order to fill them, he +would have to have eight + +electrons or an octet +around the cubes. + +So what we're seeing is this +is notes from 1902 -- he + +actually didn't publish any of +this work or these ideas that + +led to Lewis structures until +1916, but his early class + +notes were used as evidence +about how long ago he actually + +came up with the idea of it. + +So it's really neat to think +that your counterparts 100 + +years ago right here at MIT +could have been sitting in a + +class where they had Lewis as +their lecturer, and he's + +putting forth these ideas -- +these are actually his lecture + +notes, even though it wasn't +even published yet, and giving + +this idea of Lewis structure, +which is exactly what we keep + +using today in order to make +a lot of these predictions. + +So, let's see how some of this +works, and hopefully your + +counterparts from 100 years +ago would also be able to + +think about how this works, even +if they don't have the + +quantum mechanics behind +the individual electron + +configurations for atoms. So +I said that we want to be + +talking about valence electrons +here, so that means + +if we're talking about, for +example, the octet rule for an + +f f molecule where we have two +fluorine atoms, we need to + +write the valence electrons +as dots around them. + +So let's do a quick clicker +question, and you tell me how + +many valence electrons +does fluorine have? + +Remember, valence electrons +are different from core, + +they're only the outer-most +electrons in + +the outer-most shell. + +So, 10 seconds on this, +this should + +be fast. OK, great. + +Good job on the clicker +questions today. + +So we have seven valence +electrons. + +So, let's go back to the notes, +and let's fill these + +in, seven electrons. + +Another way you could have +known them was to look at + +Lewis' notes here, where if look +at this box carefully you + +see there are seven dots around +the cube, so there are + +his seven valence electrons. + +So, we see is when we use the +octet rule to look at fluorine + +molecule, we're combining two +fluorine atoms, and what we + +end up with is an f f molecule +where they're sharing two + +electrons, so making +that covalent bond. + +But that each individual +fluorine atom has eight + +electrons, or full +octet around it. + +We can think about where those +electrons came from, so we got + +seven from the blue electrons +here, seven as shown in green + +here, but each individual +fluorine atom has eight, even + +though two of those are being +shared between both of them. + +So, the octet rule is a general +rule that you'll for + +all of the atoms. There are some +exceptions, which we'll + +get to later, but the only a +big exception here is with + +hydrogen, which has a special +stability that's associated + +with two electrons. + +This should make a lot of sense, +because we know that a + +hydrogen has 1 s as it's +outer-most or valence orbital, + +so it can be filled up just +with two 1 s electrons. + +And we give different names, +depending on what kind of + +electrons we're dealing with, +so, for example, with h c l + +here, we can talk about +having bonded + +versus lone pair electrons. + +So, in terms of the c l atom, +we need to talk about each + +atom individually. + +How many bonding electrons +does c l have? + +All right. + +Let's see, we've got a mixed +response here, it turns out it + +has two bonding electrons. + +I heard some people say one, +and that's a good guess, + +remember they're actually +sharing. + +So these two electrons, they +belong to chlorine, they also + +belong to hydrogen, but they +do, in fact, belong to + +chlorine as well. + +There's no one person owning +them, so they both have two + +electrons here that +are bonding. + +So how many lone pair electrons +do we have? + +OK. + +I hear six and three, so both +are sort of right, we have 6 + +lone pair electrons, +which means that we + +have three lone pairs. + +So, in terms of thinking about +how to draw a Lewis structure, + +I won't go through this today +or any day in terms of just + +reading through the rules, you +can read that yourself. + +But what we'll do is go through +each of these rules in + +terms of an example. + +So, what will start with on +Monday is doing the most + +simple example of methane +using these + +Lewis structure rules. + +So, don't forget to study this +weekend and get those extra + +practice problems from +the course website. \ No newline at end of file diff --git a/5wCZqdCDafc.txt b/5wCZqdCDafc.txt new file mode 100644 index 0000000000000000000000000000000000000000..17432bdb79966a6d839689886fb44d38ac2c8b2c --- /dev/null +++ b/5wCZqdCDafc.txt @@ -0,0 +1,1499 @@ +align:start position:0% + +so connectivity is more than just an All + + align:start position:0% +so connectivity is more than just an All + + + align:start position:0% +so connectivity is more than just an All +or Nothing Affair we can talk about how + + align:start position:0% +or Nothing Affair we can talk about how + + + align:start position:0% +or Nothing Affair we can talk about how +connected a graph is so let's begin with + + align:start position:0% +connected a graph is so let's begin with + + + align:start position:0% +connected a graph is so let's begin with +two vertices two vertices are said to be + + align:start position:0% +two vertices two vertices are said to be + + + align:start position:0% +two vertices two vertices are said to be +K Edge connected if they remain + + align:start position:0% +K Edge connected if they remain + + + align:start position:0% +K Edge connected if they remain +connected if you remove fewer than K + + align:start position:0% +connected if you remove fewer than K + + + align:start position:0% +connected if you remove fewer than K +edges from the + + align:start position:0% +edges from the + + + align:start position:0% +edges from the +graph let's look at an example so here's + + align:start position:0% +graph let's look at an example so here's + + + align:start position:0% +graph let's look at an example so here's +a graph and let's focus on those two + + align:start position:0% +a graph and let's focus on those two + + + align:start position:0% +a graph and let's focus on those two +vertices that I've highlighted in + + align:start position:0% +vertices that I've highlighted in + + + align:start position:0% +vertices that I've highlighted in +magenta they are one EDG connected + + align:start position:0% +magenta they are one EDG connected + + + align:start position:0% +magenta they are one EDG connected +because they're connected and if you + + align:start position:0% +because they're connected and if you + + + align:start position:0% +because they're connected and if you +remove one Edge they become disconnected + + align:start position:0% +remove one Edge they become disconnected + + + align:start position:0% +remove one Edge they become disconnected +so they're one Edge connected but + + align:start position:0% +so they're one Edge connected but + + + align:start position:0% +so they're one Edge connected but +they're not two Edge connected if in + + align:start position:0% +they're not two Edge connected if in + + + align:start position:0% +they're not two Edge connected if in +particular if I delete that edge um then + + align:start position:0% +particular if I delete that edge um then + + + align:start position:0% +particular if I delete that edge um then +they no longer is a path between the two + + align:start position:0% +they no longer is a path between the two + + + align:start position:0% +they no longer is a path between the two +magenta + + align:start position:0% +magenta + + + align:start position:0% +magenta +vertices um here's an example of two + + align:start position:0% +vertices um here's an example of two + + + align:start position:0% +vertices um here's an example of two +vertices these two green vertices that + + align:start position:0% +vertices these two green vertices that + + + align:start position:0% +vertices these two green vertices that +are two Edge connected that means that I + + align:start position:0% +are two Edge connected that means that I + + + align:start position:0% +are two Edge connected that means that I +can remove any number of edges less than + + align:start position:0% +can remove any number of edges less than + + + align:start position:0% +can remove any number of edges less than +two which is to say one Edge and they'll + + align:start position:0% +two which is to say one Edge and they'll + + + align:start position:0% +two which is to say one Edge and they'll +stay connected so I could try but if if + + align:start position:0% +stay connected so I could try but if if + + + align:start position:0% +stay connected so I could try but if if +I do remove two vertices they become + + align:start position:0% +I do remove two vertices they become + + + align:start position:0% +I do remove two vertices they become +disconnected so with those two vertices + + align:start position:0% +disconnected so with those two vertices + + + align:start position:0% +disconnected so with those two vertices +now I uh those two edges judiciously + + align:start position:0% +now I uh those two edges judiciously + + + align:start position:0% +now I uh those two edges judiciously +selected there will no longer be a path + + align:start position:0% +selected there will no longer be a path + + + align:start position:0% +selected there will no longer be a path +between the two green + + align:start position:0% + + + + align:start position:0% + +vertices uh for a three-edge connected + + align:start position:0% +vertices uh for a three-edge connected + + + align:start position:0% +vertices uh for a three-edge connected +example we can look at these two uh + + align:start position:0% +example we can look at these two uh + + + align:start position:0% +example we can look at these two uh +vertices highlighted in purple and + + align:start position:0% +vertices highlighted in purple and + + + align:start position:0% +vertices highlighted in purple and +discover that we can remove any two + + align:start position:0% +discover that we can remove any two + + + align:start position:0% +discover that we can remove any two +edges and they're still going to be + + align:start position:0% +edges and they're still going to be + + + align:start position:0% +edges and they're still going to be +stuck together you can kind of see that + + align:start position:0% +stuck together you can kind of see that + + + align:start position:0% +stuck together you can kind of see that +because they're in a cycle here and in a + + align:start position:0% +because they're in a cycle here and in a + + + align:start position:0% +because they're in a cycle here and in a +cycle there and in order to break them + + align:start position:0% +cycle there and in order to break them + + + align:start position:0% +cycle there and in order to break them +you're going to have to break both + + align:start position:0% +you're going to have to break both + + + align:start position:0% +you're going to have to break both +Cycles um which means uh breaking uh two + + align:start position:0% +Cycles um which means uh breaking uh two + + + align:start position:0% +Cycles um which means uh breaking uh two +edges to break two + + align:start position:0% +edges to break two + + + align:start position:0% +edges to break two +cycles + + align:start position:0% +cycles + + + align:start position:0% +cycles +and uh if you remove three on the other + + align:start position:0% +and uh if you remove three on the other + + + align:start position:0% +and uh if you remove three on the other +hand you can't separate them so if I cut + + align:start position:0% +hand you can't separate them so if I cut + + + align:start position:0% +hand you can't separate them so if I cut +these three + + align:start position:0% +these three + + + align:start position:0% +these three +edges um I might have been more obvious + + align:start position:0% +edges um I might have been more obvious + + + align:start position:0% +edges um I might have been more obvious +to cut that one but I'm doing it this + + align:start position:0% +to cut that one but I'm doing it this + + + align:start position:0% +to cut that one but I'm doing it this +way to make it interesting if I cut + + align:start position:0% +way to make it interesting if I cut + + + align:start position:0% +way to make it interesting if I cut +these three edges then in fact I wind up + + align:start position:0% +these three edges then in fact I wind up + + + align:start position:0% +these three edges then in fact I wind up +with no path between those two vertices + + align:start position:0% +with no path between those two vertices + + + align:start position:0% +with no path between those two vertices +so they are two Edge connected um uh + + align:start position:0% +so they are two Edge connected um uh + + + align:start position:0% +so they are two Edge connected um uh +they are three Edge connected but not + + align:start position:0% +they are three Edge connected but not + + + align:start position:0% +they are three Edge connected but not +four Edge connected meaning you can + + align:start position:0% +four Edge connected meaning you can + + + align:start position:0% +four Edge connected meaning you can +remove two but you can't remove three + + align:start position:0% +remove two but you can't remove three + + + align:start position:0% +remove two but you can't remove three +and keep them connected for a whole + + align:start position:0% +and keep them connected for a whole + + + align:start position:0% +and keep them connected for a whole +graph um a whole graph is kedge + + align:start position:0% +graph um a whole graph is kedge + + + align:start position:0% +graph um a whole graph is kedge +connected if every two vertices are + + align:start position:0% +connected if every two vertices are + + + align:start position:0% +connected if every two vertices are +kedge connected um uh and the point of + + align:start position:0% +kedge connected um uh and the point of + + + align:start position:0% +kedge connected um uh and the point of +this degree of connectivity is to + + align:start position:0% +this degree of connectivity is to + + + align:start position:0% +this degree of connectivity is to +measure one one motivation of it is it + + align:start position:0% +measure one one motivation of it is it + + + align:start position:0% +measure one one motivation of it is it +if you think of this graph as indicating + + align:start position:0% +if you think of this graph as indicating + + + align:start position:0% +if you think of this graph as indicating +uh a communication Network where + + align:start position:0% +uh a communication Network where + + + align:start position:0% +uh a communication Network where +vertices are centers that are sending + + align:start position:0% +vertices are centers that are sending + + + align:start position:0% +vertices are centers that are sending +and receiving data and an edge + + align:start position:0% +and receiving data and an edge + + + align:start position:0% +and receiving data and an edge +corresponds to having some kind of a + + align:start position:0% +corresponds to having some kind of a + + + align:start position:0% +corresponds to having some kind of a +Channel or cable between uh adjacent + + align:start position:0% +Channel or cable between uh adjacent + + + align:start position:0% +Channel or cable between uh adjacent +centers then connectivity is a measure + + align:start position:0% +centers then connectivity is a measure + + + align:start position:0% +centers then connectivity is a measure +of how many of your channels or cables + + align:start position:0% +of how many of your channels or cables + + + align:start position:0% +of how many of your channels or cables +can go down and still have the property + + align:start position:0% +can go down and still have the property + + + align:start position:0% +can go down and still have the property +that every Center of information can + + align:start position:0% +that every Center of information can + + + align:start position:0% +that every Center of information can +communicate with every other Center of + + align:start position:0% +communicate with every other Center of + + + align:start position:0% +communicate with every other Center of +information so how many connections can + + align:start position:0% +information so how many connections can + + + align:start position:0% +information so how many connections can +fail without cutting off + + align:start position:0% +fail without cutting off + + + align:start position:0% +fail without cutting off +communication here's an example of a + + align:start position:0% +communication here's an example of a + + + align:start position:0% +communication here's an example of a +graph that globally this is was the + + align:start position:0% +graph that globally this is was the + + + align:start position:0% +graph that globally this is was the +graph that we saw before that has some + + align:start position:0% +graph that we saw before that has some + + + align:start position:0% +graph that we saw before that has some +vertices that are one Edge connected + + align:start position:0% +vertices that are one Edge connected + + + align:start position:0% +vertices that are one Edge connected +others that are two other others that + + align:start position:0% +others that are two other others that + + + align:start position:0% +others that are two other others that +are three but the graph as a whole is + + align:start position:0% +are three but the graph as a whole is + + + align:start position:0% +are three but the graph as a whole is +only one Edge connected because there's + + align:start position:0% +only one Edge connected because there's + + + align:start position:0% +only one Edge connected because there's +this one Edge that can be removed that + + align:start position:0% +this one Edge that can be removed that + + + align:start position:0% +this one Edge that can be removed that +splits it in + + align:start position:0% +splits it in + + + align:start position:0% +splits it in +two this graph on the other hand a + + align:start position:0% +two this graph on the other hand a + + + align:start position:0% +two this graph on the other hand a +modification of it is two Edge connected + + align:start position:0% +modification of it is two Edge connected + + + align:start position:0% +modification of it is two Edge connected +now I can remove any one Edge and no + + align:start position:0% +now I can remove any one Edge and no + + + align:start position:0% +now I can remove any one Edge and no +matter what single edge I remove this + + align:start position:0% +matter what single edge I remove this + + + align:start position:0% +matter what single edge I remove this +will remain a connected graph which + + align:start position:0% +will remain a connected graph which + + + align:start position:0% +will remain a connected graph which +makes it two Edge connected now there's + + align:start position:0% +makes it two Edge connected now there's + + + align:start position:0% +makes it two Edge connected now there's +a corresponding definition of vertex + + align:start position:0% +a corresponding definition of vertex + + + align:start position:0% +a corresponding definition of vertex +connected uh meaning it's K vertex + + align:start position:0% +connected uh meaning it's K vertex + + + align:start position:0% +connected uh meaning it's K vertex +connected if you can remove any number + + align:start position:0% +connected if you can remove any number + + + align:start position:0% +connected if you can remove any number +of vertices up to uh K and it will stay + + align:start position:0% +of vertices up to uh K and it will stay + + + align:start position:0% +of vertices up to uh K and it will stay +connected if it's K vertex connected + + align:start position:0% +connected if it's K vertex connected + + + align:start position:0% +connected if it's K vertex connected +it's certainly K Edge connected but not + + align:start position:0% +it's certainly K Edge connected but not + + + align:start position:0% +it's certainly K Edge connected but not +conversely um if here's a graph that is + + align:start position:0% +conversely um if here's a graph that is + + + align:start position:0% +conversely um if here's a graph that is +two uh Edge vertex connected but one + + align:start position:0% +two uh Edge vertex connected but one + + + align:start position:0% +two uh Edge vertex connected but one +vertex connected if you remove uh one + + align:start position:0% +vertex connected if you remove uh one + + + align:start position:0% +vertex connected if you remove uh one +vertex it breaks if you remove that + + align:start position:0% +vertex it breaks if you remove that + + + align:start position:0% +vertex it breaks if you remove that +vertex it breaks but on the other hand + + align:start position:0% +vertex it breaks but on the other hand + + + align:start position:0% +vertex it breaks but on the other hand +it needs two edges to be cut in order to + + align:start position:0% +it needs two edges to be cut in order to + + + align:start position:0% +it needs two edges to be cut in order to +uh split the graph in + + align:start position:0% +uh split the graph in + + + align:start position:0% +uh split the graph in +two the complete graph on N vertices um + + align:start position:0% +two the complete graph on N vertices um + + + align:start position:0% +two the complete graph on N vertices um +is uh uh to cut it up it + + align:start position:0% +is uh uh to cut it up it + + + align:start position:0% +is uh uh to cut it up it +requires cutting uh n minus one edges + + align:start position:0% +requires cutting uh n minus one edges + + + align:start position:0% +requires cutting uh n minus one edges +and in fact n minus one vertices to + + align:start position:0% +and in fact n minus one vertices to + + + align:start position:0% +and in fact n minus one vertices to +break it up because everything is + + align:start position:0% +break it up because everything is + + + align:start position:0% +break it up because everything is +connected to everything else so knen is + + align:start position:0% +connected to everything else so knen is + + + align:start position:0% +connected to everything else so knen is +as a connected a graph on N vertices as + + align:start position:0% +as a connected a graph on N vertices as + + + align:start position:0% +as a connected a graph on N vertices as +you can possibly have but of course it's + + align:start position:0% +you can possibly have but of course it's + + + align:start position:0% +you can possibly have but of course it's +got a lot of edges it's got n choose two + + align:start position:0% +got a lot of edges it's got n choose two + + + align:start position:0% +got a lot of edges it's got n choose two +edges or about n * n minus one over two + + align:start position:0% +edges or about n * n minus one over two + + + align:start position:0% +edges or about n * n minus one over two +edges another interesting structure is + + align:start position:0% +edges another interesting structure is + + + align:start position:0% +edges another interesting structure is +the n-dimensional hyper Cube so the + + align:start position:0% +the n-dimensional hyper Cube so the + + + align:start position:0% +the n-dimensional hyper Cube so the +square is a two-dimensional and the cube + + align:start position:0% +square is a two-dimensional and the cube + + + align:start position:0% +square is a two-dimensional and the cube +the the ordinary cube is the H3 has uh + + align:start position:0% +the the ordinary cube is the H3 has uh + + + align:start position:0% +the the ordinary cube is the H3 has uh +has eight vertices and looks like a cube + + align:start position:0% +has eight vertices and looks like a cube + + + align:start position:0% +has eight vertices and looks like a cube +uh and in enal the way we Define hn is + + align:start position:0% +uh and in enal the way we Define hn is + + + align:start position:0% +uh and in enal the way we Define hn is +that its vertices are the binary strings + + align:start position:0% +that its vertices are the binary strings + + + align:start position:0% +that its vertices are the binary strings +of length n and two vertices are + + align:start position:0% +of length n and two vertices are + + + align:start position:0% +of length n and two vertices are +adjacent if they differ in one bit + + align:start position:0% +adjacent if they differ in one bit + + + align:start position:0% +adjacent if they differ in one bit +they're the same except that in one + + align:start position:0% +they're the same except that in one + + + align:start position:0% +they're the same except that in one +coordinate one of them has a one and the + + align:start position:0% +coordinate one of them has a one and the + + + align:start position:0% +coordinate one of them has a one and the +other has a zero in that case you can + + align:start position:0% +other has a zero in that case you can + + + align:start position:0% +other has a zero in that case you can +make the edges + + align:start position:0% +make the edges + + + align:start position:0% +make the edges +adjacent um it turns out that the uh the + + align:start position:0% +adjacent um it turns out that the uh the + + + align:start position:0% +adjacent um it turns out that the uh the +n-dimensional hypergraph is n vertex + + align:start position:0% +n-dimensional hypergraph is n vertex + + + align:start position:0% +n-dimensional hypergraph is n vertex +connected and this is worked out in a + + align:start position:0% +connected and this is worked out in a + + + align:start position:0% +connected and this is worked out in a +homework or class problem so to + + align:start position:0% +homework or class problem so to + + + align:start position:0% +homework or class problem so to +summarize um well actually before we + + align:start position:0% +summarize um well actually before we + + + align:start position:0% +summarize um well actually before we +summarize there's a basic theorem that + + align:start position:0% +summarize there's a basic theorem that + + + align:start position:0% +summarize there's a basic theorem that +we're not going to prove it's just a + + align:start position:0% +we're not going to prove it's just a + + + align:start position:0% +we're not going to prove it's just a +little bit too much of a challenge for + + align:start position:0% +little bit too much of a challenge for + + + align:start position:0% +little bit too much of a challenge for +us to get into uh would take maybe a + + align:start position:0% +us to get into uh would take maybe a + + + align:start position:0% +us to get into uh would take maybe a +couple of lectures is to prove manger + + align:start position:0% +couple of lectures is to prove manger + + + align:start position:0% +couple of lectures is to prove manger +theorem uh which says that um a graph is + + align:start position:0% +theorem uh which says that um a graph is + + + align:start position:0% +theorem uh which says that um a graph is +K uh vertex + + align:start position:0% +K uh vertex + + + align:start position:0% +K uh vertex +connected uh if and only if uh you can + + align:start position:0% +connected uh if and only if uh you can + + + align:start position:0% +connected uh if and only if uh you can +connect any two vertices with completely + + align:start position:0% +connect any two vertices with completely + + + align:start position:0% +connect any two vertices with completely +nonoverlapping different paths K of them + + align:start position:0% +nonoverlapping different paths K of them + + + align:start position:0% +nonoverlapping different paths K of them +so um if two vertices are K connected + + align:start position:0% +so um if two vertices are K connected + + + align:start position:0% +so um if two vertices are K connected +then they're are uh completely separate + + align:start position:0% +then they're are uh completely separate + + + align:start position:0% +then they're are uh completely separate +K separate paths connecting them which + + align:start position:0% +K separate paths connecting them which + + + align:start position:0% +K separate paths connecting them which +means of course that you have to cut + + align:start position:0% +means of course that you have to cut + + + align:start position:0% +means of course that you have to cut +each of the paths in order to separate + + align:start position:0% +each of the paths in order to separate + + + align:start position:0% +each of the paths in order to separate +them and a similar theorem goes for Edge + + align:start position:0% +them and a similar theorem goes for Edge + + + align:start position:0% +them and a similar theorem goes for Edge +connected so to summarize uh about some + + align:start position:0% +connected so to summarize uh about some + + + align:start position:0% +connected so to summarize uh about some +graphs that we know about uh if given + + align:start position:0% +graphs that we know about uh if given + + + align:start position:0% +graphs that we know about uh if given +that connectivity measures fa tolerance + + align:start position:0% +that connectivity measures fa tolerance + + + align:start position:0% +that connectivity measures fa tolerance +in a network we're interested in well + + align:start position:0% +in a network we're interested in well + + + align:start position:0% +in a network we're interested in well +how many edges did it take to a achieve + + align:start position:0% +how many edges did it take to a achieve + + + align:start position:0% +how many edges did it take to a achieve +this level of connectivity so the number + + align:start position:0% +this level of connectivity so the number + + + align:start position:0% +this level of connectivity so the number +of edges is kind of a measure of the + + align:start position:0% +of edges is kind of a measure of the + + + align:start position:0% +of edges is kind of a measure of the +cost and the complete graph on N + + align:start position:0% +cost and the complete graph on N + + + align:start position:0% +cost and the complete graph on N +vertices is n minus one connected but it + + align:start position:0% +vertices is n minus one connected but it + + + align:start position:0% +vertices is n minus one connected but it +has about n^2 over two edges the hyper + + align:start position:0% +has about n^2 over two edges the hyper + + + align:start position:0% +has about n^2 over two edges the hyper +Cube now if we're going to be talking + + align:start position:0% +Cube now if we're going to be talking + + + align:start position:0% +Cube now if we're going to be talking +about graphs of size n to be uniform the + + align:start position:0% +about graphs of size n to be uniform the + + + align:start position:0% +about graphs of size n to be uniform the +hyper Cube on hn has two to the N + + align:start position:0% +hyper Cube on hn has two to the N + + + align:start position:0% +hyper Cube on hn has two to the N +vertices so if we want an N vertex + + align:start position:0% +vertices so if we want an N vertex + + + align:start position:0% +vertices so if we want an N vertex +version we're talking about H sub log n + + align:start position:0% +version we're talking about H sub log n + + + align:start position:0% +version we're talking about H sub log n +which has n vertices uh and then it has + + align:start position:0% +which has n vertices uh and then it has + + + align:start position:0% +which has n vertices uh and then it has +about n log n over two edges so it's got + + align:start position:0% +about n log n over two edges so it's got + + + align:start position:0% +about n log n over two edges so it's got +fewer edges than the complete graph but + + align:start position:0% +fewer edges than the complete graph but + + + align:start position:0% +fewer edges than the complete graph but +uh a significantly less um exponentially + + align:start position:0% +uh a significantly less um exponentially + + + align:start position:0% +uh a significantly less um exponentially +less + + align:start position:0% +less + + + align:start position:0% +less +connectivity the grid is simply um uh + + align:start position:0% +connectivity the grid is simply um uh + + + align:start position:0% +connectivity the grid is simply um uh +like the XY uh axis uh or the XY plane + + align:start position:0% +like the XY uh axis uh or the XY plane + + + align:start position:0% +like the XY uh axis uh or the XY plane +with points at integers so that every + + align:start position:0% +with points at integers so that every + + + align:start position:0% +with points at integers so that every +node is connected to every uh to four + + align:start position:0% +node is connected to every uh to four + + + align:start position:0% +node is connected to every uh to four +adjacent nodes to one up one down one + + align:start position:0% +adjacent nodes to one up one down one + + + align:start position:0% +adjacent nodes to one up one down one +right and one left now of course when + + align:start position:0% +right and one left now of course when + + + align:start position:0% +right and one left now of course when +you get to the the edge of it if you + + align:start position:0% +you get to the the edge of it if you + + + align:start position:0% +you get to the the edge of it if you +make it finite the ones on the edge are + + align:start position:0% +make it finite the ones on the edge are + + + align:start position:0% +make it finite the ones on the edge are +only going to be two connected so you + + align:start position:0% +only going to be two connected so you + + + align:start position:0% +only going to be two connected so you +have to wrap it around in the shape of a + + align:start position:0% +have to wrap it around in the shape of a + + + align:start position:0% +have to wrap it around in the shape of a +donut to really make it work with a + + align:start position:0% +donut to really make it work with a + + + align:start position:0% +donut to really make it work with a +finite graph but if you do that then the + + align:start position:0% +finite graph but if you do that then the + + + align:start position:0% +finite graph but if you do that then the +thing is four connected um four uh Edge + + align:start position:0% +thing is four connected um four uh Edge + + + align:start position:0% +thing is four connected um four uh Edge +connected but and only has two n edges + + align:start position:0% +connected but and only has two n edges + + + align:start position:0% +connected but and only has two n edges +and then a cycle is two connected a + + align:start position:0% +and then a cycle is two connected a + + + align:start position:0% +and then a cycle is two connected a +cycle of size n is two connected with n + + align:start position:0% +cycle of size n is two connected with n + + + align:start position:0% +cycle of size n is two connected with n +vertices and finally trees which we'll + + align:start position:0% +vertices and finally trees which we'll + + + align:start position:0% +vertices and finally trees which we'll +talk about next time um are the smallest + + align:start position:0% +talk about next time um are the smallest + + + align:start position:0% +talk about next time um are the smallest +possible connected graphs they are one + + align:start position:0% +possible connected graphs they are one + + + align:start position:0% +possible connected graphs they are one +connected indeed everything is in a tree + + align:start position:0% +connected indeed everything is in a tree + + + align:start position:0% +connected indeed everything is in a tree +is connected um and they only have n + + align:start position:0% +is connected um and they only have n + + + align:start position:0% +is connected um and they only have n +minus one edges but if you remove one + + align:start position:0% +minus one edges but if you remove one + + + align:start position:0% +minus one edges but if you remove one +Edge it splits and that's sort of the + + align:start position:0% +Edge it splits and that's sort of the + + + align:start position:0% +Edge it splits and that's sort of the +summary of the K connectivity story \ No newline at end of file diff --git a/62FdhX-zS2Y.txt b/62FdhX-zS2Y.txt new file mode 100644 index 0000000000000000000000000000000000000000..449024cbc049d4cb5578939018eb911953d489ec --- /dev/null +++ b/62FdhX-zS2Y.txt @@ -0,0 +1,7003 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit MIT opencourseware + + align:start position:0% +of MIT courses visit MIT opencourseware + + + align:start position:0% +of MIT courses visit MIT opencourseware +at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu I want to discuss with you + + align:start position:0% +ocw.mit.edu I want to discuss with you + + + align:start position:0% +ocw.mit.edu I want to discuss with you +today + + align:start position:0% +today + + + align:start position:0% +today +a very topical and interesting + + align:start position:0% +a very topical and interesting + + + align:start position:0% +a very topical and interesting +question which is the notion of stem + + align:start position:0% + + + + align:start position:0% + +cells in fact I'm going to discuss two + + align:start position:0% +cells in fact I'm going to discuss two + + + align:start position:0% +cells in fact I'm going to discuss two +things the first of which is another + + align:start position:0% +things the first of which is another + + + align:start position:0% +things the first of which is another +concept that you need following on from + + align:start position:0% +concept that you need following on from + + + align:start position:0% +concept that you need following on from +the concepts we had right at the + + align:start position:0% +the concepts we had right at the + + + align:start position:0% +the concepts we had right at the +beginning of + + align:start position:0% +beginning of + + + align:start position:0% +beginning of +lecture I feel like this + + align:start position:0% +lecture I feel like this + + + align:start position:0% +lecture I feel like this +microphone + + align:start position:0% +microphone + + + align:start position:0% +microphone +the first is a concept that you'll need + + align:start position:0% +the first is a concept that you'll need + + + align:start position:0% +the first is a concept that you'll need +in addition to the ones we started + + align:start position:0% +in addition to the ones we started + + + align:start position:0% +in addition to the ones we started +lecture with and then we'll talk about + + align:start position:0% +lecture with and then we'll talk about + + + align:start position:0% +lecture with and then we'll talk about +stem cells so + + align:start position:0% + + + + align:start position:0% + +today we'll talk about + + align:start position:0% + + + + align:start position:0% + +potency and then we'll talk about stem + + align:start position:0% + + + + align:start position:0% + +cells potency along with fate + + align:start position:0% +cells potency along with fate + + + align:start position:0% +cells potency along with fate +determination and differentiation ation + + align:start position:0% +determination and differentiation ation + + + align:start position:0% +determination and differentiation ation +is one of those terms that you need to + + align:start position:0% +is one of those terms that you need to + + + align:start position:0% +is one of those terms that you need to +know and you need to understand in order + + align:start position:0% +know and you need to understand in order + + + align:start position:0% +know and you need to understand in order +to understand stem + + align:start position:0% + + + + align:start position:0% + +cells potency refers to the number of + + align:start position:0% +cells potency refers to the number of + + + align:start position:0% +cells potency refers to the number of +possible fates that a cell can + + align:start position:0% + + + + align:start position:0% + +acquire number of possible + + align:start position:0% + + + + align:start position:0% + +fates + + align:start position:0% + + + + align:start position:0% + +open to a + + align:start position:0% + + + + align:start position:0% + +cell and this is a very important + + align:start position:0% +cell and this is a very important + + + align:start position:0% +cell and this is a very important +concept of development because in + + align:start position:0% +concept of development because in + + + align:start position:0% +concept of development because in +general potency decreases with age and + + align:start position:0% +general potency decreases with age and + + + align:start position:0% +general potency decreases with age and +decreases as different parts of the + + align:start position:0% +decreases as different parts of the + + + align:start position:0% +decreases as different parts of the +organism become + + align:start position:0% +organism become + + + align:start position:0% +organism become +specialized so in general potency + + align:start position:0% +specialized so in general potency + + + align:start position:0% +specialized so in general potency +decreases with age + + align:start position:0% + + + + align:start position:0% + +but I will put in here and we'll explore + + align:start position:0% +but I will put in here and we'll explore + + + align:start position:0% +but I will put in here and we'll explore +this more in a + + align:start position:0% + + + + align:start position:0% + +moment + + align:start position:0% +moment + + + align:start position:0% +moment +except + + align:start position:0% +except + + + align:start position:0% +except +for + + align:start position:0% + + + + align:start position:0% + +some stem + + align:start position:0% +some stem + + + align:start position:0% +some stem +cells and we haven't defined a stem cell + + align:start position:0% +cells and we haven't defined a stem cell + + + align:start position:0% +cells and we haven't defined a stem cell +yet but we + + align:start position:0% +yet but we + + + align:start position:0% +yet but we +will what kinds of potencies are there + + align:start position:0% +will what kinds of potencies are there + + + align:start position:0% +will what kinds of potencies are there +there's the big one to poy + + align:start position:0% +there's the big one to poy + + + align:start position:0% +there's the big one to poy +potent where a cell can become + + align:start position:0% + + + + align:start position:0% + +orates and there's really only one cell + + align:start position:0% +orates and there's really only one cell + + + align:start position:0% +orates and there's really only one cell +that can do this in the normal animal + + align:start position:0% +that can do this in the normal animal + + + align:start position:0% +that can do this in the normal animal +and that is the + + align:start position:0% + + + + align:start position:0% + +zygote and in most animals even as the + + align:start position:0% +zygote and in most animals even as the + + + align:start position:0% +zygote and in most animals even as the +zygote becomes just two cells or a few + + align:start position:0% +zygote becomes just two cells or a few + + + align:start position:0% +zygote becomes just two cells or a few +cells that full potency is + + align:start position:0% +cells that full potency is + + + align:start position:0% +cells that full potency is +lost and cells instead + + align:start position:0% +lost and cells instead + + + align:start position:0% +lost and cells instead +in the embryo are multi or plur + + align:start position:0% +in the embryo are multi or plur + + + align:start position:0% +in the embryo are multi or plur +potent which means that they can acquire + + align:start position:0% +potent which means that they can acquire + + + align:start position:0% +potent which means that they can acquire +many Fates but not all + + align:start position:0% + + + + align:start position:0% + +Fates or embryonic cells especially in + + align:start position:0% +Fates or embryonic cells especially in + + + align:start position:0% +Fates or embryonic cells especially in +the early + + align:start position:0% +the early + + + align:start position:0% +the early +embryo and many stem cells can also + + align:start position:0% +embryo and many stem cells can also + + + align:start position:0% +embryo and many stem cells can also +become are also multi poent or Pur poent + + align:start position:0% +become are also multi poent or Pur poent + + + align:start position:0% +become are also multi poent or Pur poent +and then as time progresses is that a + + align:start position:0% +and then as time progresses is that a + + + align:start position:0% +and then as time progresses is that a +hand up yes + + align:start position:0% + + + + align:start position:0% + +sir that's a great question the question + + align:start position:0% +sir that's a great question the question + + + align:start position:0% +sir that's a great question the question +is how do I reconcile what I'm telling + + align:start position:0% +is how do I reconcile what I'm telling + + + align:start position:0% +is how do I reconcile what I'm telling +you with the fact that you can get + + align:start position:0% +you with the fact that you can get + + + align:start position:0% +you with the fact that you can get +identical sex tlets or octuplets + + align:start position:0% +identical sex tlets or octuplets + + + align:start position:0% +identical sex tlets or octuplets +actually it's a good question that's + + align:start position:0% +actually it's a good question that's + + + align:start position:0% +actually it's a good question that's +true in different animals the ear very + + align:start position:0% +true in different animals the ear very + + + align:start position:0% +true in different animals the ear very +early embryonic cells are sometimes + + align:start position:0% +early embryonic cells are sometimes + + + align:start position:0% +early embryonic cells are sometimes +times toy potent up to a while okay and + + align:start position:0% +times toy potent up to a while okay and + + + align:start position:0% +times toy potent up to a while okay and +so for example in armadillo here's a + + align:start position:0% +so for example in armadillo here's a + + + align:start position:0% +so for example in armadillo here's a +piece of you know fact for your back + + align:start position:0% +piece of you know fact for your back + + + align:start position:0% +piece of you know fact for your back +pockets in the armadillo the eight cell + + align:start position:0% +pockets in the armadillo the eight cell + + + align:start position:0% +pockets in the armadillo the eight cell +embryo almost always splits into eight + + align:start position:0% +embryo almost always splits into eight + + + align:start position:0% +embryo almost always splits into eight +single cells Each of which becomes a + + align:start position:0% +single cells Each of which becomes a + + + align:start position:0% +single cells Each of which becomes a +baby armadillo okay so those cells are + + align:start position:0% +baby armadillo okay so those cells are + + + align:start position:0% +baby armadillo okay so those cells are +toy potent in mice even at the two cell + + align:start position:0% +toy potent in mice even at the two cell + + + align:start position:0% +toy potent in mice even at the two cell +stage the two mouth cells are probably + + align:start position:0% +stage the two mouth cells are probably + + + align:start position:0% +stage the two mouth cells are probably +not equivalently potent and they're not + + align:start position:0% +not equivalently potent and they're not + + + align:start position:0% +not equivalently potent and they're not +to potent so you very very seldom almost + + align:start position:0% +to potent so you very very seldom almost + + + align:start position:0% +to potent so you very very seldom almost +never get identical Mouse + + align:start position:0% +never get identical Mouse + + + align:start position:0% +never get identical Mouse +twins okay so it's you know it's it's + + align:start position:0% +twins okay so it's you know it's it's + + + align:start position:0% +twins okay so it's you know it's it's +one of these generalities and if you ask + + align:start position:0% +one of these generalities and if you ask + + + align:start position:0% +one of these generalities and if you ask +me you get the specifics are a bit + + align:start position:0% +me you get the specifics are a bit + + + align:start position:0% +me you get the specifics are a bit +different as cell fate restriction + + align:start position:0% +different as cell fate restriction + + + align:start position:0% +different as cell fate restriction +continues cells can become bip poent or + + align:start position:0% +continues cells can become bip poent or + + + align:start position:0% +continues cells can become bip poent or +uni + + align:start position:0% +uni + + + align:start position:0% +uni +poent + + align:start position:0% +poent + + + align:start position:0% +poent +whereby one or just two Fates are open + + align:start position:0% +whereby one or just two Fates are open + + + align:start position:0% +whereby one or just two Fates are open +to + + align:start position:0% +to + + + align:start position:0% +to +them and so if we + + align:start position:0% +them and so if we + + + align:start position:0% +them and so if we +look taking this concept let's now start + + align:start position:0% +look taking this concept let's now start + + + align:start position:0% +look taking this concept let's now start +the lecture about stem + + align:start position:0% +the lecture about stem + + + align:start position:0% +the lecture about stem +cells you're going to need this concept + + align:start position:0% +cells you're going to need this concept + + + align:start position:0% +cells you're going to need this concept +stem cells I'll point out whatever they + + align:start position:0% +stem cells I'll point out whatever they + + + align:start position:0% +stem cells I'll point out whatever they +are got almost 3,000 hits yesterday on + + align:start position:0% +are got almost 3,000 hits yesterday on + + + align:start position:0% +are got almost 3,000 hits yesterday on +Google News this is way below baseball + + align:start position:0% +Google News this is way below baseball + + + align:start position:0% +Google News this is way below baseball +which got 45,000 I checked but still you + + align:start position:0% +which got 45,000 I checked but still you + + + align:start position:0% +which got 45,000 I checked but still you +know as science topics go stem cells are + + align:start position:0% +know as science topics go stem cells are + + + align:start position:0% +know as science topics go stem cells are +really up there and they're on the + + align:start position:0% +really up there and they're on the + + + align:start position:0% +really up there and they're on the +covers of magazines over and over again + + align:start position:0% +covers of magazines over and over again + + + align:start position:0% +covers of magazines over and over again +and we'll talk more about why that is + + align:start position:0% +and we'll talk more about why that is + + + align:start position:0% +and we'll talk more about why that is +here's a diagram it's not on your + + align:start position:0% +here's a diagram it's not on your + + + align:start position:0% +here's a diagram it's not on your +handouts that I drew for you let's not + + align:start position:0% +handouts that I drew for you let's not + + + align:start position:0% +handouts that I drew for you let's not +dwell on it but let's now move on to + + align:start position:0% +dwell on it but let's now move on to + + + align:start position:0% +dwell on it but let's now move on to +topic number + + align:start position:0% +topic number + + + align:start position:0% +topic number +two which will fold in this concept of + + align:start position:0% +two which will fold in this concept of + + + align:start position:0% +two which will fold in this concept of +potency and the concepts of Fate + + align:start position:0% +potency and the concepts of Fate + + + align:start position:0% +potency and the concepts of Fate +determination and + + align:start position:0% +determination and + + + align:start position:0% +determination and +differentiation and talk about stem + + align:start position:0% + + + + align:start position:0% + +cells + + align:start position:0% + + + + align:start position:0% + +and let's do as is our custom let's + + align:start position:0% +and let's do as is our custom let's + + + align:start position:0% +and let's do as is our custom let's +define what a stem cell is I think that + + align:start position:0% +define what a stem cell is I think that + + + align:start position:0% +define what a stem cell is I think that +a stem cell can be defined as a cell of + + align:start position:0% +a stem cell can be defined as a cell of + + + align:start position:0% +a stem cell can be defined as a cell of +variable potency that has the capacity + + align:start position:0% +variable potency that has the capacity + + + align:start position:0% +variable potency that has the capacity +to + + align:start position:0% + + + + align:start position:0% + +self-renew + + align:start position:0% +self-renew + + + align:start position:0% +self-renew +cells of + + align:start position:0% + + + + align:start position:0% + +variable + + align:start position:0% +variable + + + align:start position:0% +variable +potency + + align:start position:0% + + + + align:start position:0% + +that can + + align:start position:0% +that can + + + align:start position:0% +that can +self-renew they can make more of + + align:start position:0% + + + + align:start position:0% + +themselves despite the hype despite + + align:start position:0% +themselves despite the hype despite + + + align:start position:0% +themselves despite the hype despite +covers of Time Magazine and almost every + + align:start position:0% +covers of Time Magazine and almost every + + + align:start position:0% +covers of Time Magazine and almost every +front page of every newspaper across the + + align:start position:0% +front page of every newspaper across the + + + align:start position:0% +front page of every newspaper across the +world stem cells are normally found in + + align:start position:0% +world stem cells are normally found in + + + align:start position:0% +world stem cells are normally found in +our bodies and + + align:start position:0% + + + + align:start position:0% + +normally + + align:start position:0% +normally + + + align:start position:0% +normally +as we'll explore they're used for organ + + align:start position:0% +as we'll explore they're used for organ + + + align:start position:0% +as we'll explore they're used for organ +maintenance and + + align:start position:0% + + + + align:start position:0% + +repair organ maintenance and + + align:start position:0% + + + + align:start position:0% + +repair but the thing you know that has + + align:start position:0% +repair but the thing you know that has + + + align:start position:0% +repair but the thing you know that has +everyone fired up is that you can + + align:start position:0% +everyone fired up is that you can + + + align:start position:0% +everyone fired up is that you can +somehow harness these cells for + + align:start position:0% +somehow harness these cells for + + + align:start position:0% +somehow harness these cells for +therapeutic purposes and that you can + + align:start position:0% +therapeutic purposes and that you can + + + align:start position:0% +therapeutic purposes and that you can +repair + + align:start position:0% +repair + + + align:start position:0% +repair +what the body cannot by being clever and + + align:start position:0% +what the body cannot by being clever and + + + align:start position:0% +what the body cannot by being clever and +using the power of these + + align:start position:0% +using the power of these + + + align:start position:0% +using the power of these +cells as they normally have it or as you + + align:start position:0% +cells as they normally have it or as you + + + align:start position:0% +cells as they normally have it or as you +can give it to them and so there's this + + align:start position:0% +can give it to them and so there's this + + + align:start position:0% +can give it to them and so there's this +question of therapy and therapeutic stem + + align:start position:0% +question of therapy and therapeutic stem + + + align:start position:0% +question of therapy and therapeutic stem +cells where the idea again is that you + + align:start position:0% +cells where the idea again is that you + + + align:start position:0% +cells where the idea again is that you +would + + align:start position:0% +would + + + align:start position:0% +would +repair a damaged + + align:start position:0% + + + + align:start position:0% + +organ + + align:start position:0% +organ + + + align:start position:0% +organ +by + + align:start position:0% + + + + align:start position:0% + +introducing somehow injecting or + + align:start position:0% +introducing somehow injecting or + + + align:start position:0% +introducing somehow injecting or +otherwise + + align:start position:0% + + + + align:start position:0% + +introducing extra or somehow special + + align:start position:0% +introducing extra or somehow special + + + align:start position:0% +introducing extra or somehow special +stem cells which I am going to + + align:start position:0% +stem cells which I am going to + + + align:start position:0% +stem cells which I am going to +abbreviate here to for as SC by indu by + + align:start position:0% +abbreviate here to for as SC by indu by + + + align:start position:0% +abbreviate here to for as SC by indu by +introducing extra stem cells into a + + align:start position:0% +introducing extra stem cells into a + + + align:start position:0% +introducing extra stem cells into a +damaged + + align:start position:0% +damaged + + + align:start position:0% +damaged +body does this work it does work it + + align:start position:0% +body does this work it does work it + + + align:start position:0% +body does this work it does work it +works + + align:start position:0% +works + + + align:start position:0% +works +for the hematopoetic system as in bone + + align:start position:0% +for the hematopoetic system as in bone + + + align:start position:0% +for the hematopoetic system as in bone +marrow + + align:start position:0% + + + + align:start position:0% + +transplants and it also works for skin + + align:start position:0% +transplants and it also works for skin + + + align:start position:0% +transplants and it also works for skin +cell + + align:start position:0% + + + + align:start position:0% + +transplants um what is just put skin + + align:start position:0% +transplants um what is just put skin + + + align:start position:0% +transplants um what is just put skin +cells + + align:start position:0% +cells + + + align:start position:0% +cells +okay + + align:start position:0% + + + + align:start position:0% + +skin stem cells can be grown from your + + align:start position:0% +skin stem cells can be grown from your + + + align:start position:0% +skin stem cells can be grown from your +own skin and in the case of burn victims + + align:start position:0% +own skin and in the case of burn victims + + + align:start position:0% +own skin and in the case of burn victims +this has really saved countless lives + + align:start position:0% +this has really saved countless lives + + + align:start position:0% +this has really saved countless lives +the original technology began to be + + align:start position:0% +the original technology began to be + + + align:start position:0% +the original technology began to be +developed here at MIT by Professor + + align:start position:0% +developed here at MIT by Professor + + + align:start position:0% +developed here at MIT by Professor +Howard green who's now at Harvard but + + align:start position:0% +Howard green who's now at Harvard but + + + align:start position:0% +Howard green who's now at Harvard but +the idea is to take your skin and grow + + align:start position:0% +the idea is to take your skin and grow + + + align:start position:0% +the idea is to take your skin and grow +it on something like G or some kind of + + align:start position:0% +it on something like G or some kind of + + + align:start position:0% +it on something like G or some kind of +solid support and then to cover a burn + + align:start position:0% +solid support and then to cover a burn + + + align:start position:0% +solid support and then to cover a burn +patient + + align:start position:0% +patient + + + align:start position:0% +patient +with layers of support on which there + + align:start position:0% +with layers of support on which there + + + align:start position:0% +with layers of support on which there +are some stem cells and these stem cells + + align:start position:0% +are some stem cells and these stem cells + + + align:start position:0% +are some stem cells and these stem cells +will help fill in the holes in the skin + + align:start position:0% +will help fill in the holes in the skin + + + align:start position:0% +will help fill in the holes in the skin +left by the burn normally when a wound + + align:start position:0% +left by the burn normally when a wound + + + align:start position:0% +left by the burn normally when a wound +heals as I'm sure you've noticed it + + align:start position:0% +heals as I'm sure you've noticed it + + + align:start position:0% +heals as I'm sure you've noticed it +heals from the sides the only way a + + align:start position:0% +heals from the sides the only way a + + + align:start position:0% +heals from the sides the only way a +wound can heal is from the side and if + + align:start position:0% +wound can heal is from the side and if + + + align:start position:0% +wound can heal is from the side and if +it's a big wound it can take a very very + + align:start position:0% +it's a big wound it can take a very very + + + align:start position:0% +it's a big wound it can take a very very +long time to heal and you can get + + align:start position:0% +long time to heal and you can get + + + align:start position:0% +long time to heal and you can get +infections and so on while the healing + + align:start position:0% +infections and so on while the healing + + + align:start position:0% +infections and so on while the healing +process is going on so seeding the + + align:start position:0% +process is going on so seeding the + + + align:start position:0% +process is going on so seeding the +inside of a wound with stem cells that + + align:start position:0% +inside of a wound with stem cells that + + + align:start position:0% +inside of a wound with stem cells that +can start the skin regeneration process + + align:start position:0% +can start the skin regeneration process + + + align:start position:0% +can start the skin regeneration process +and seal up the body against infection + + align:start position:0% +and seal up the body against infection + + + align:start position:0% +and seal up the body against infection +has been incredibly useful and we'll + + align:start position:0% +has been incredibly useful and we'll + + + align:start position:0% +has been incredibly useful and we'll +talk more about bone marrow transplants + + align:start position:0% +talk more about bone marrow transplants + + + align:start position:0% +talk more about bone marrow transplants +in a + + align:start position:0% +in a + + + align:start position:0% +in a +moment + + align:start position:0% +moment + + + align:start position:0% +moment +okay we previously talked about this + + align:start position:0% +okay we previously talked about this + + + align:start position:0% +okay we previously talked about this +process by which cells decide or + + align:start position:0% +process by which cells decide or + + + align:start position:0% +process by which cells decide or +undecided initially they decide what + + align:start position:0% +undecided initially they decide what + + + align:start position:0% +undecided initially they decide what +they're going to become and then they + + align:start position:0% +they're going to become and then they + + + align:start position:0% +they're going to become and then they +differentiate into their final function + + align:start position:0% +differentiate into their final function + + + align:start position:0% +differentiate into their final function +stem cells fit into this litany + + align:start position:0% +stem cells fit into this litany + + + align:start position:0% +stem cells fit into this litany +somewhere between the commitment stage + + align:start position:0% +somewhere between the commitment stage + + + align:start position:0% +somewhere between the commitment stage +and the differentiation stage and in + + align:start position:0% +and the differentiation stage and in + + + align:start position:0% +and the differentiation stage and in +this diagram these multiple arrows are + + align:start position:0% +this diagram these multiple arrows are + + + align:start position:0% +this diagram these multiple arrows are +there for a reason there are multiple + + align:start position:0% +there for a reason there are multiple + + + align:start position:0% +there for a reason there are multiple +steps between commitment and + + align:start position:0% +steps between commitment and + + + align:start position:0% +steps between commitment and +differentiation and somewhere along the + + align:start position:0% +differentiation and somewhere along the + + + align:start position:0% +differentiation and somewhere along the +way a group of cells with capacities + + align:start position:0% +way a group of cells with capacities + + + align:start position:0% +way a group of cells with capacities +will talk + + align:start position:0% +will talk + + + align:start position:0% +will talk +about Le leaves this lineage and sits + + align:start position:0% +about Le leaves this lineage and sits + + + align:start position:0% +about Le leaves this lineage and sits +around and waits partially determined so + + align:start position:0% +around and waits partially determined so + + + align:start position:0% +around and waits partially determined so +that it can go on and make more + + align:start position:0% +that it can go on and make more + + + align:start position:0% +that it can go on and make more +differentiated cells when they're + + align:start position:0% + + + + align:start position:0% + +needed and I've added on there the + + align:start position:0% +needed and I've added on there the + + + align:start position:0% +needed and I've added on there the +potency timeline decreasing with age + + align:start position:0% +potency timeline decreasing with age + + + align:start position:0% +potency timeline decreasing with age +of the developing + + align:start position:0% +of the developing + + + align:start position:0% +of the developing +animal but let's Di diagram the notion + + align:start position:0% +animal but let's Di diagram the notion + + + align:start position:0% +animal but let's Di diagram the notion +of stem cells on the + + align:start position:0% +of stem cells on the + + + align:start position:0% +of stem cells on the +board stem cells generally divide + + align:start position:0% + + + + align:start position:0% + +slowly here's + + align:start position:0% + + + + align:start position:0% + +one it's a variable potency it may be + + align:start position:0% +one it's a variable potency it may be + + + align:start position:0% +one it's a variable potency it may be +multi potent it may be bip + + align:start position:0% +multi potent it may be bip + + + align:start position:0% +multi potent it may be bip +potential and it is somewhat + + align:start position:0% + + + + align:start position:0% + +committed + + align:start position:0% + + + + align:start position:0% + +which is a slightly difficult concept + + align:start position:0% +which is a slightly difficult concept + + + align:start position:0% +which is a slightly difficult concept +because last time we talked about + + align:start position:0% +because last time we talked about + + + align:start position:0% +because last time we talked about +committed versus uncommitted but now I'm + + align:start position:0% +committed versus uncommitted but now I'm + + + align:start position:0% +committed versus uncommitted but now I'm +telling you something can be somewhat + + align:start position:0% +telling you something can be somewhat + + + align:start position:0% +telling you something can be somewhat +committed and that gets to this multiple + + align:start position:0% +committed and that gets to this multiple + + + align:start position:0% +committed and that gets to this multiple +arrows there where as cells progress in + + align:start position:0% +arrows there where as cells progress in + + + align:start position:0% +arrows there where as cells progress in +their fate decisions they change their + + align:start position:0% +their fate decisions they change their + + + align:start position:0% +their fate decisions they change their +molecular signature and they really do + + align:start position:0% +molecular signature and they really do + + + align:start position:0% +molecular signature and they really do +become closer and closer to a cell + + align:start position:0% +become closer and closer to a cell + + + align:start position:0% +become closer and closer to a cell +that's made a decision but it's kind of + + align:start position:0% +that's made a decision but it's kind of + + + align:start position:0% +that's made a decision but it's kind of +like you know if you weighing up going + + align:start position:0% +like you know if you weighing up going + + + align:start position:0% +like you know if you weighing up going +to med school or going to graduate + + align:start position:0% +to med school or going to graduate + + + align:start position:0% +to med school or going to graduate +school in bioengineering you know you've + + align:start position:0% +school in bioengineering you know you've + + + align:start position:0% +school in bioengineering you know you've +decided that it'll be one or the other + + align:start position:0% +decided that it'll be one or the other + + + align:start position:0% +decided that it'll be one or the other +but you haven't decided which you're + + align:start position:0% +but you haven't decided which you're + + + align:start position:0% +but you haven't decided which you're +somewhat committed and then when you + + align:start position:0% +somewhat committed and then when you + + + align:start position:0% +somewhat committed and then when you +make the decision to go to graduate + + align:start position:0% +make the decision to go to graduate + + + align:start position:0% +make the decision to go to graduate +school you've now become committed okay + + align:start position:0% +school you've now become committed okay + + + align:start position:0% +school you've now become committed okay +so the cell is doing the same kind of + + align:start position:0% +so the cell is doing the same kind of + + + align:start position:0% +so the cell is doing the same kind of +notion + + align:start position:0% +notion + + + align:start position:0% +notion +there there's your stem cell variable + + align:start position:0% +there there's your stem cell variable + + + align:start position:0% +there there's your stem cell variable +potency under the correct stimulus that + + align:start position:0% +potency under the correct stimulus that + + + align:start position:0% +potency under the correct stimulus that +stem cell will + + align:start position:0% +stem cell will + + + align:start position:0% +stem cell will +divide to give rise to two different + + align:start position:0% +divide to give rise to two different + + + align:start position:0% +divide to give rise to two different +cells one is another stem + + align:start position:0% + + + + align:start position:0% + +cell and the other is something we'll + + align:start position:0% +cell and the other is something we'll + + + align:start position:0% +cell and the other is something we'll +call a + + align:start position:0% + + + + align:start position:0% + +progenitor the progenitor is more + + align:start position:0% +progenitor the progenitor is more + + + align:start position:0% +progenitor the progenitor is more +committed than the stem + + align:start position:0% + + + + align:start position:0% + +cell the progenitor cell is going to go + + align:start position:0% +cell the progenitor cell is going to go + + + align:start position:0% +cell the progenitor cell is going to go +on and divide usually a + + align:start position:0% + + + + align:start position:0% + +lot so progenitors divide + + align:start position:0% + + + + align:start position:0% + +rapidly and their progeny will + + align:start position:0% +rapidly and their progeny will + + + align:start position:0% +rapidly and their progeny will +eventually go on and + + align:start position:0% +eventually go on and + + + align:start position:0% +eventually go on and +differentiate into one or more different + + align:start position:0% +differentiate into one or more different + + + align:start position:0% +differentiate into one or more different +kinds of + + align:start position:0% + + + + align:start position:0% + +cells + + align:start position:0% +cells + + + align:start position:0% +cells +maybe a stripey cell and a spotted cell + + align:start position:0% +maybe a stripey cell and a spotted cell + + + align:start position:0% +maybe a stripey cell and a spotted cell +type and a cell type with + + align:start position:0% +type and a cell type with + + + align:start position:0% +type and a cell type with +squiggles and so here are the + + align:start position:0% +squiggles and so here are the + + + align:start position:0% +squiggles and so here are the +differentiated cell + + align:start position:0% + + + + align:start position:0% + +types and the number of different + + align:start position:0% +types and the number of different + + + align:start position:0% +types and the number of different +differentiated cells that comes out of + + align:start position:0% +differentiated cells that comes out of + + + align:start position:0% +differentiated cells that comes out of +this process is a reflection of the + + align:start position:0% +this process is a reflection of the + + + align:start position:0% +this process is a reflection of the +potency of the stem cell okay so here + + align:start position:0% +potency of the stem cell okay so here + + + align:start position:0% +potency of the stem cell okay so here +you've got these progenitors the idea is + + align:start position:0% +you've got these progenitors the idea is + + + align:start position:0% +you've got these progenitors the idea is +that these + + align:start position:0% +that these + + + align:start position:0% +that these +progenitors will have similar potency + + align:start position:0% +progenitors will have similar potency + + + align:start position:0% +progenitors will have similar potency +but as I'll show you there's a whole + + align:start position:0% +but as I'll show you there's a whole + + + align:start position:0% +but as I'll show you there's a whole +variation on this but here the + + align:start position:0% +variation on this but here the + + + align:start position:0% +variation on this but here the +number of differentiated cell + + align:start position:0% +number of differentiated cell + + + align:start position:0% +number of differentiated cell +types the number of cell types + + align:start position:0% + + + + align:start position:0% + +reflects + + align:start position:0% + + + + align:start position:0% + +potency of the stem + + align:start position:0% +potency of the stem + + + align:start position:0% +potency of the stem +cell + + align:start position:0% + + + + align:start position:0% + +okay this kind of diagram is called a + + align:start position:0% +okay this kind of diagram is called a + + + align:start position:0% +okay this kind of diagram is called a +lineage diagram it tells you what not + + align:start position:0% +lineage diagram it tells you what not + + + align:start position:0% +lineage diagram it tells you what not +only what the final fate of the cell is + + align:start position:0% +only what the final fate of the cell is + + + align:start position:0% +only what the final fate of the cell is +it tells you something about the + + align:start position:0% +it tells you something about the + + + align:start position:0% +it tells you something about the +progress towards that final fate so a + + align:start position:0% + + + + align:start position:0% + +lineage we can Define as the set of cell + + align:start position:0% + + + + align:start position:0% + +types + + align:start position:0% +types + + + align:start position:0% +types +arising from a stem cell or a + + align:start position:0% + + + + align:start position:0% + +progenitor + + align:start position:0% + + + + align:start position:0% + +okay let's talk about the discovery of + + align:start position:0% +okay let's talk about the discovery of + + + align:start position:0% +okay let's talk about the discovery of +stem cells because this is something + + align:start position:0% +stem cells because this is something + + + align:start position:0% +stem cells because this is something +that really was pivotal in helping + + align:start position:0% +that really was pivotal in helping + + + align:start position:0% +that really was pivotal in helping +understand whether or not there was some + + align:start position:0% +understand whether or not there was some + + + align:start position:0% +understand whether or not there was some +way that the body normally repaired + + align:start position:0% +way that the body normally repaired + + + align:start position:0% +way that the body normally repaired +itself it was clear that during early + + align:start position:0% +itself it was clear that during early + + + align:start position:0% +itself it was clear that during early +development there was lots of cell + + align:start position:0% +development there was lots of cell + + + align:start position:0% +development there was lots of cell +division and lots of changes cell types + + align:start position:0% +division and lots of changes cell types + + + align:start position:0% +division and lots of changes cell types +were formed and organs were formed but + + align:start position:0% +were formed and organs were formed but + + + align:start position:0% +were formed and organs were formed but +it really wasn't clear in the adult how + + align:start position:0% +it really wasn't clear in the adult how + + + align:start position:0% +it really wasn't clear in the adult how +much repair there was how much turnover + + align:start position:0% +much repair there was how much turnover + + + align:start position:0% +much repair there was how much turnover +of tissues there were and really what + + align:start position:0% +of tissues there were and really what + + + align:start position:0% +of tissues there were and really what +the whole dynamic process of maintaining + + align:start position:0% +the whole dynamic process of maintaining + + + align:start position:0% +the whole dynamic process of maintaining +the adult + + align:start position:0% + + + + align:start position:0% + +Wars + + align:start position:0% + + + + align:start position:0% + +and the discovery of stem cells came + + align:start position:0% +and the discovery of stem cells came + + + align:start position:0% +and the discovery of stem cells came +about because people looked to see how + + align:start position:0% +about because people looked to see how + + + align:start position:0% +about because people looked to see how +long cells lived and what they + + align:start position:0% +long cells lived and what they + + + align:start position:0% +long cells lived and what they +found was found using a turnover + + align:start position:0% + + + + align:start position:0% + +assay that measures the half life of + + align:start position:0% + + + + align:start position:0% + +cells and they found that in all almost + + align:start position:0% +cells and they found that in all almost + + + align:start position:0% +cells and they found that in all almost +all organs in fact probably in all + + align:start position:0% +all organs in fact probably in all + + + align:start position:0% +all organs in fact probably in all +organs cells did not live forever they + + align:start position:0% +organs cells did not live forever they + + + align:start position:0% +organs cells did not live forever they +turned over they died and they were + + align:start position:0% +turned over they died and they were + + + align:start position:0% +turned over they died and they were +replaced by new + + align:start position:0% + + + + align:start position:0% + +cells and this turnover assay implied + + align:start position:0% +cells and this turnover assay implied + + + align:start position:0% +cells and this turnover assay implied +that there was some kind of + + align:start position:0% +that there was some kind of + + + align:start position:0% +that there was some kind of +replacement and the cells doing the + + align:start position:0% +replacement and the cells doing the + + + align:start position:0% +replacement and the cells doing the +replacement were called stem + + align:start position:0% + + + + align:start position:0% + +cells you find this by a pulse Chase + + align:start position:0% + + + + align:start position:0% + +assay which will go over on your handout + + align:start position:0% +assay which will go over on your handout + + + align:start position:0% +assay which will go over on your handout +in a + + align:start position:0% +in a + + + align:start position:0% +in a +moment and what was found was really + + align:start position:0% +moment and what was found was really + + + align:start position:0% +moment and what was found was really +variable for different organs + + align:start position:0% +variable for different organs + + + align:start position:0% +variable for different organs +firstly all organs + + align:start position:0% + + + + align:start position:0% + +about show cell + + align:start position:0% +about show cell + + + align:start position:0% +about show cell +turnover + + align:start position:0% + + + + align:start position:0% + +red blood cells have a half life of + + align:start position:0% +red blood cells have a half life of + + + align:start position:0% +red blood cells have a half life of +about 120 + + align:start position:0% + + + + align:start position:0% + +days there are a lot of red blood cells + + align:start position:0% +days there are a lot of red blood cells + + + align:start position:0% +days there are a lot of red blood cells +in your + + align:start position:0% + + + + align:start position:0% + +body and in fact that implies that there + + align:start position:0% +body and in fact that implies that there + + + align:start position:0% +body and in fact that implies that there +are about 10 to the 7th new red blood + + align:start position:0% +are about 10 to the 7th new red blood + + + align:start position:0% +are about 10 to the 7th new red blood +cells made a + + align:start position:0% + + + + align:start position:0% + +day + + align:start position:0% +day + + + align:start position:0% +day +in your intestine the half life of cells + + align:start position:0% +in your intestine the half life of cells + + + align:start position:0% +in your intestine the half life of cells +is 3 to 5 days in the small + + align:start position:0% + + + + align:start position:0% + +intestine and the hair on your + + align:start position:0% +intestine and the hair on your + + + align:start position:0% +intestine and the hair on your +head has a half life of about four + + align:start position:0% + + + + align:start position:0% + +years so it's variable for different + + align:start position:0% +years so it's variable for different + + + align:start position:0% +years so it's variable for different +kinds of + + align:start position:0% +kinds of + + + align:start position:0% +kinds of +cells if you look at your your first + + align:start position:0% +cells if you look at your your first + + + align:start position:0% +cells if you look at your your first +handout it diagrams a pulse Chase assay + + align:start position:0% +handout it diagrams a pulse Chase assay + + + align:start position:0% +handout it diagrams a pulse Chase assay +where a cell + + align:start position:0% + + + + align:start position:0% + +population is labeled with a nucleotide + + align:start position:0% +population is labeled with a nucleotide + + + align:start position:0% +population is labeled with a nucleotide +analog it's a normal nucleotide but it's + + align:start position:0% +analog it's a normal nucleotide but it's + + + align:start position:0% +analog it's a normal nucleotide but it's +got a bromine added to it and it acts + + align:start position:0% +got a bromine added to it and it acts + + + align:start position:0% +got a bromine added to it and it acts +like + + align:start position:0% +like + + + align:start position:0% +like +deoxythymidine gets incorporated into + + align:start position:0% +deoxythymidine gets incorporated into + + + align:start position:0% +deoxythymidine gets incorporated into +DNA and you give just a short pulse of + + align:start position:0% +DNA and you give just a short pulse of + + + align:start position:0% +DNA and you give just a short pulse of +this nucleotide analog so only some of + + align:start position:0% +this nucleotide analog so only some of + + + align:start position:0% +this nucleotide analog so only some of +the cells get labeled and you only give + + align:start position:0% +the cells get labeled and you only give + + + align:start position:0% +the cells get labeled and you only give +it for a short time so you get a labeled + + align:start position:0% +it for a short time so you get a labeled + + + align:start position:0% +it for a short time so you get a labeled +cell population and then you stop the + + align:start position:0% +cell population and then you stop the + + + align:start position:0% +cell population and then you stop the +labeling by adding lots of unlabeled + + align:start position:0% +labeling by adding lots of unlabeled + + + align:start position:0% +labeling by adding lots of unlabeled +thymidine and that's called a Chase and + + align:start position:0% +thymidine and that's called a Chase and + + + align:start position:0% +thymidine and that's called a Chase and +you follow the cells over this long + + align:start position:0% +you follow the cells over this long + + + align:start position:0% +you follow the cells over this long +Chase period and then you can watch and + + align:start position:0% +Chase period and then you can watch and + + + align:start position:0% +Chase period and then you can watch and +see what happens to those cells that you + + align:start position:0% +see what happens to those cells that you + + + align:start position:0% +see what happens to those cells that you +initially labeled over a very short time + + align:start position:0% +initially labeled over a very short time + + + align:start position:0% +initially labeled over a very short time +and so in this example I've got four + + align:start position:0% +and so in this example I've got four + + + align:start position:0% +and so in this example I've got four +cells initially labeled over time there + + align:start position:0% +cells initially labeled over time there + + + align:start position:0% +cells initially labeled over time there +are only two cells left and if if you + + align:start position:0% +are only two cells left and if if you + + + align:start position:0% +are only two cells left and if if you +measure the time from going from four + + align:start position:0% +measure the time from going from four + + + align:start position:0% +measure the time from going from four +cells to two cells you can get to the + + align:start position:0% +cells to two cells you can get to the + + + align:start position:0% +cells to two cells you can get to the +half life of that cell + + align:start position:0% +half life of that cell + + + align:start position:0% +half life of that cell +population + + align:start position:0% +population + + + align:start position:0% +population +okay you can also you don't have a + + align:start position:0% +okay you can also you don't have a + + + align:start position:0% +okay you can also you don't have a +handout for this just look on the screen + + align:start position:0% +handout for this just look on the screen + + + align:start position:0% +handout for this just look on the screen +you can also follow this labeled cell + + align:start position:0% +you can also follow this labeled cell + + + align:start position:0% +you can also follow this labeled cell +population and see what those cells + + align:start position:0% +population and see what those cells + + + align:start position:0% +population and see what those cells +become and you can see that they go on + + align:start position:0% +become and you can see that they go on + + + align:start position:0% +become and you can see that they go on +to differentiate as particular cell + + align:start position:0% +to differentiate as particular cell + + + align:start position:0% +to differentiate as particular cell +types so this is a kind of way of + + align:start position:0% +types so this is a kind of way of + + + align:start position:0% +types so this is a kind of way of +labeling the lineage of these cells and + + align:start position:0% +labeling the lineage of these cells and + + + align:start position:0% +labeling the lineage of these cells and +that is useful too + + align:start position:0% + + + + align:start position:0% + +this was the theory behind stem cell + + align:start position:0% +this was the theory behind stem cell + + + align:start position:0% +this was the theory behind stem cell +definition but what is a stem cell look + + align:start position:0% +definition but what is a stem cell look + + + align:start position:0% +definition but what is a stem cell look +like and how do you isolate + + align:start position:0% + + + + align:start position:0% + +one it turns out that that's really + + align:start position:0% +one it turns out that that's really + + + align:start position:0% +one it turns out that that's really +difficult so isolation and + + align:start position:0% + + + + align:start position:0% + +assay in the adult stem cells are very + + align:start position:0% +assay in the adult stem cells are very + + + align:start position:0% +assay in the adult stem cells are very +very + + align:start position:0% + + + + align:start position:0% + +rare and that is one of the + + align:start position:0% +rare and that is one of the + + + align:start position:0% +rare and that is one of the +issues with using stem cells for therapy + + align:start position:0% +issues with using stem cells for therapy + + + align:start position:0% +issues with using stem cells for therapy +there are very few of them and they're + + align:start position:0% +there are very few of them and they're + + + align:start position:0% +there are very few of them and they're +hard to isolate hematopoetic stem + + align:start position:0% + + + + align:start position:0% + +cells comprise about 0 1% of the bone + + align:start position:0% +cells comprise about 0 1% of the bone + + + align:start position:0% +cells comprise about 0 1% of the bone +marrow which is where the stem cells + + align:start position:0% +marrow which is where the stem cells + + + align:start position:0% +marrow which is where the stem cells +reside and where the precursors of your + + align:start position:0% +reside and where the precursors of your + + + align:start position:0% +reside and where the precursors of your +whole blood and immune system + + align:start position:0% + + + + align:start position:0% + +reside the way that this was dealt with + + align:start position:0% +reside the way that this was dealt with + + + align:start position:0% +reside the way that this was dealt with +was through a really clever technique + + align:start position:0% +was through a really clever technique + + + align:start position:0% +was through a really clever technique +that has the acronym of fact I'll give + + align:start position:0% +that has the acronym of fact I'll give + + + align:start position:0% +that has the acronym of fact I'll give +you a slide in a moment it stands for + + align:start position:0% +you a slide in a moment it stands for + + + align:start position:0% +you a slide in a moment it stands for +fluoresence activated cell sorting we'll + + align:start position:0% +fluoresence activated cell sorting we'll + + + align:start position:0% +fluoresence activated cell sorting we'll +go to a slide in a moment so we don't + + align:start position:0% +go to a slide in a moment so we don't + + + align:start position:0% +go to a slide in a moment so we don't +have to spell it out and the idea behind + + align:start position:0% +have to spell it out and the idea behind + + + align:start position:0% +have to spell it out and the idea behind +facts is that you + + align:start position:0% +facts is that you + + + align:start position:0% +facts is that you +label stem cells and you might be + + align:start position:0% +label stem cells and you might be + + + align:start position:0% +label stem cells and you might be +guessing what to label them with but you + + align:start position:0% +guessing what to label them with but you + + + align:start position:0% +guessing what to label them with but you +label them usually via their cell + + align:start position:0% +label them usually via their cell + + + align:start position:0% +label them usually via their cell +surface + + align:start position:0% + + + + align:start position:0% + +proteins with some kind of + + align:start position:0% +proteins with some kind of + + + align:start position:0% +proteins with some kind of +tag often an antibody + + align:start position:0% + + + + align:start position:0% + +tag and then you can use that tag to + + align:start position:0% +tag and then you can use that tag to + + + align:start position:0% +tag and then you can use that tag to +make them different colors and you can + + align:start position:0% +make them different colors and you can + + + align:start position:0% +make them different colors and you can +then sort them cell by cell through this + + align:start position:0% +then sort them cell by cell through this + + + align:start position:0% +then sort them cell by cell through this +special fluorescent activated cell + + align:start position:0% +special fluorescent activated cell + + + align:start position:0% +special fluorescent activated cell +sorder sort individual + + align:start position:0% + + + + align:start position:0% + +cells and then you can + + align:start position:0% +cells and then you can + + + align:start position:0% +cells and then you can +assay individual cells or small groups + + align:start position:0% +assay individual cells or small groups + + + align:start position:0% +assay individual cells or small groups +of them for stem cell + + align:start position:0% + + + + align:start position:0% + +properties let's look at a slide of how + + align:start position:0% +properties let's look at a slide of how + + + align:start position:0% +properties let's look at a slide of how +the facts the fluorescence activated + + align:start position:0% +the facts the fluorescence activated + + + align:start position:0% +the facts the fluorescence activated +cell sort of works no let's not I've + + align:start position:0% +cell sort of works no let's not I've + + + align:start position:0% +cell sort of works no let's not I've +really gotten ahead of myself here and + + align:start position:0% +really gotten ahead of myself here and + + + align:start position:0% +really gotten ahead of myself here and +I'm going to to go back because I want + + align:start position:0% +I'm going to to go back because I want + + + align:start position:0% +I'm going to to go back because I want +to show you + + align:start position:0% +to show you + + + align:start position:0% +to show you +this hold on to that thought and let's + + align:start position:0% +this hold on to that thought and let's + + + align:start position:0% +this hold on to that thought and let's +go back to this notion of a pulse Chase + + align:start position:0% +go back to this notion of a pulse Chase + + + align:start position:0% +go back to this notion of a pulse Chase +assay I forgot that I had this here this + + align:start position:0% +assay I forgot that I had this here this + + + align:start position:0% +assay I forgot that I had this here this +is really important this is a pulse + + align:start position:0% +is really important this is a pulse + + + align:start position:0% +is really important this is a pulse +Chase assay of intestinal cells and so + + align:start position:0% +Chase assay of intestinal cells and so + + + align:start position:0% +Chase assay of intestinal cells and so +your small + + align:start position:0% +your small + + + align:start position:0% +your small +intestine + + align:start position:0% +intestine + + + align:start position:0% +intestine +lies inside your + + align:start position:0% +lies inside your + + + align:start position:0% +lies inside your +belly and if you look at its Anatomy it + + align:start position:0% +belly and if you look at its Anatomy it + + + align:start position:0% +belly and if you look at its Anatomy it +contains many tubes + + align:start position:0% +contains many tubes + + + align:start position:0% +contains many tubes +whose folds are throw whose whose + + align:start position:0% +whose folds are throw whose whose + + + align:start position:0% +whose folds are throw whose whose +surface is thrown into folds to increase + + align:start position:0% +surface is thrown into folds to increase + + + align:start position:0% +surface is thrown into folds to increase +the surface area for food absorption and + + align:start position:0% +the surface area for food absorption and + + + align:start position:0% +the surface area for food absorption and +if you look at these folds they are very + + align:start position:0% +if you look at these folds they are very + + + align:start position:0% +if you look at these folds they are very +closely packed so you get a huge surface + + align:start position:0% +closely packed so you get a huge surface + + + align:start position:0% +closely packed so you get a huge surface +area increase and the cells of these + + align:start position:0% +area increase and the cells of these + + + align:start position:0% +area increase and the cells of these +folds that are doing the food absorption + + align:start position:0% +folds that are doing the food absorption + + + align:start position:0% +folds that are doing the food absorption +turn over every 3 to 5 days those are + + align:start position:0% +turn over every 3 to 5 days those are + + + align:start position:0% +turn over every 3 to 5 days those are +the ones I was talking about so if you + + align:start position:0% +the ones I was talking about so if you + + + align:start position:0% +the ones I was talking about so if you +blow up one of these folds which is + + align:start position:0% +blow up one of these folds which is + + + align:start position:0% +blow up one of these folds which is +called a villis there's the part that's + + align:start position:0% +called a villis there's the part that's + + + align:start position:0% +called a villis there's the part that's +sticking up into the cavity into the + + align:start position:0% +sticking up into the cavity into the + + + align:start position:0% +sticking up into the cavity into the +Lumen of the small intestine and then + + align:start position:0% +Lumen of the small intestine and then + + + align:start position:0% +Lumen of the small intestine and then +there's this part that kind of dips down + + align:start position:0% +there's this part that kind of dips down + + + align:start position:0% +there's this part that kind of dips down +into the lining of the intestine which + + align:start position:0% +into the lining of the intestine which + + + align:start position:0% +into the lining of the intestine which +is called a crypt the stem cells lie + + align:start position:0% +is called a crypt the stem cells lie + + + align:start position:0% +is called a crypt the stem cells lie +somewhere at the base of the crypt it's + + align:start position:0% +somewhere at the base of the crypt it's + + + align:start position:0% +somewhere at the base of the crypt it's +not exactly clear where but if you but + + align:start position:0% +not exactly clear where but if you but + + + align:start position:0% +not exactly clear where but if you but +the idea is that somewhere at the bottom + + align:start position:0% +the idea is that somewhere at the bottom + + + align:start position:0% +the idea is that somewhere at the bottom +of this Crypt there these stem cells + + align:start position:0% +of this Crypt there these stem cells + + + align:start position:0% +of this Crypt there these stem cells +that under specific conditions will + + align:start position:0% +that under specific conditions will + + + align:start position:0% +that under specific conditions will +start to proliferate and they will move + + align:start position:0% +start to proliferate and they will move + + + align:start position:0% +start to proliferate and they will move +up into the villis and replace the + + align:start position:0% +up into the villis and replace the + + + align:start position:0% +up into the villis and replace the +villis cells that are dying you can + + align:start position:0% +villis cells that are dying you can + + + align:start position:0% +villis cells that are dying you can +monitor this by doing a pulse Chase + + align:start position:0% +monitor this by doing a pulse Chase + + + align:start position:0% +monitor this by doing a pulse Chase +experiment so here's the Crypt and + + align:start position:0% +experiment so here's the Crypt and + + + align:start position:0% +experiment so here's the Crypt and +they've given in this experiment a pulse + + align:start position:0% +they've given in this experiment a pulse + + + align:start position:0% +they've given in this experiment a pulse +of thymidine has been given and you're + + align:start position:0% +of thymidine has been given and you're + + + align:start position:0% +of thymidine has been given and you're +looking kind of at time zero right after + + align:start position:0% +looking kind of at time zero right after + + + align:start position:0% +looking kind of at time zero right after +the pulse of of thymidine has been given + + align:start position:0% +the pulse of of thymidine has been given + + + align:start position:0% +the pulse of of thymidine has been given +here are the cells the black cells in + + align:start position:0% +here are the cells the black cells in + + + align:start position:0% +here are the cells the black cells in +the cryp they're labeled and then if you + + align:start position:0% +the cryp they're labeled and then if you + + + align:start position:0% +the cryp they're labeled and then if you +look over time you can see that these + + align:start position:0% +look over time you can see that these + + + align:start position:0% +look over time you can see that these +black cells move away from the Crypt + + align:start position:0% +black cells move away from the Crypt + + + align:start position:0% +black cells move away from the Crypt +they're moving up into the villa and + + align:start position:0% +they're moving up into the villa and + + + align:start position:0% +they're moving up into the villa and +here they are actually right on top of + + align:start position:0% +here they are actually right on top of + + + align:start position:0% +here they are actually right on top of +the villis replacing the cells that were + + align:start position:0% +the villis replacing the cells that were + + + align:start position:0% +the villis replacing the cells that were +turning over so that's a really + + align:start position:0% +turning over so that's a really + + + align:start position:0% +turning over so that's a really +beautiful demonstration of a pulse Chase + + align:start position:0% +beautiful demonstration of a pulse Chase + + + align:start position:0% +beautiful demonstration of a pulse Chase +assay okay now we can go to our + + align:start position:0% +assay okay now we can go to our + + + align:start position:0% +assay okay now we can go to our +fluorescence activated cell + + align:start position:0% + + + + align:start position:0% + +sorder the idea is that you take a mix + + align:start position:0% +sorder the idea is that you take a mix + + + align:start position:0% +sorder the idea is that you take a mix +of cells you don't have this on your + + align:start position:0% +of cells you don't have this on your + + + align:start position:0% +of cells you don't have this on your +handout just look on the screen the + + align:start position:0% +handout just look on the screen the + + + align:start position:0% +handout just look on the screen the +cells are labeled with fluorescent + + align:start position:0% +cells are labeled with fluorescent + + + align:start position:0% +cells are labeled with fluorescent +antibodies and you put them into a + + align:start position:0% +antibodies and you put them into a + + + align:start position:0% +antibodies and you put them into a +reservoir and droplet Generator and the + + align:start position:0% +reservoir and droplet Generator and the + + + align:start position:0% +reservoir and droplet Generator and the +cells drop out of this reservoir one at + + align:start position:0% +cells drop out of this reservoir one at + + + align:start position:0% +cells drop out of this reservoir one at +a time and as they drop out they go past + + align:start position:0% +a time and as they drop out they go past + + + align:start position:0% +a time and as they drop out they go past +a laser and you can tune the laser to + + align:start position:0% +a laser and you can tune the laser to + + + align:start position:0% +a laser and you can tune the laser to +whatever wavelengths you want it excites + + align:start position:0% +whatever wavelengths you want it excites + + + align:start position:0% +whatever wavelengths you want it excites +the cells and if the cells emit in the + + align:start position:0% +the cells and if the cells emit in the + + + align:start position:0% +the cells and if the cells emit in the +particular wavelength you're interested + + align:start position:0% +particular wavelength you're interested + + + align:start position:0% +particular wavelength you're interested +in the detector will detect that and + + align:start position:0% +in the detector will detect that and + + + align:start position:0% +in the detector will detect that and +then it actually gives a charge to the + + align:start position:0% +then it actually gives a charge to the + + + align:start position:0% +then it actually gives a charge to the +cell that it is the correct fluoresence + + align:start position:0% +cell that it is the correct fluoresence + + + align:start position:0% +cell that it is the correct fluoresence +and as the cells are dropping down the + + align:start position:0% +and as the cells are dropping down the + + + align:start position:0% +and as the cells are dropping down the +cells of the correct color are deflected + + align:start position:0% +cells of the correct color are deflected + + + align:start position:0% +cells of the correct color are deflected +by an electric charge and different + + align:start position:0% +by an electric charge and different + + + align:start position:0% +by an electric charge and different +color cells can be collected into + + align:start position:0% +color cells can be collected into + + + align:start position:0% +color cells can be collected into +different flasks okay this really works + + align:start position:0% +different flasks okay this really works + + + align:start position:0% +different flasks okay this really works +it's a fantastic machine you can collect + + align:start position:0% +it's a fantastic machine you can collect + + + align:start position:0% +it's a fantastic machine you can collect +cells about you know you can collect + + align:start position:0% +cells about you know you can collect + + + align:start position:0% +cells about you know you can collect +millions of cells an hour it's pretty + + align:start position:0% +millions of cells an hour it's pretty + + + align:start position:0% +millions of cells an hour it's pretty +quick but you do it one cell at a time + + align:start position:0% +quick but you do it one cell at a time + + + align:start position:0% +quick but you do it one cell at a time +and in that way you can isolate cells + + align:start position:0% +and in that way you can isolate cells + + + align:start position:0% +and in that way you can isolate cells +which have got stem cell properties + + align:start position:0% +which have got stem cell properties + + + align:start position:0% +which have got stem cell properties +okay so you've used your fax machine + + align:start position:0% +okay so you've used your fax machine + + + align:start position:0% +okay so you've used your fax machine +you've got cells that look as though + + align:start position:0% +you've got cells that look as though + + + align:start position:0% +you've got cells that look as though +they've got stem cell properties and + + align:start position:0% + + + + align:start position:0% + +now let's look at the + + align:start position:0% + + + + align:start position:0% + +assays that may be used and there are + + align:start position:0% +assays that may be used and there are + + + align:start position:0% +assays that may be used and there are +three assays that you should know one is + + align:start position:0% +three assays that you should know one is + + + align:start position:0% +three assays that you should know one is +a repopulation + + align:start position:0% +a repopulation + + + align:start position:0% +a repopulation +assay to test stem + + align:start position:0% + + + + align:start position:0% + +cellus and this is a transplant assay + + align:start position:0% +cellus and this is a transplant assay + + + align:start position:0% +cellus and this is a transplant assay +where you're + + align:start position:0% +where you're + + + align:start position:0% +where you're +transplanting + + align:start position:0% +transplanting + + + align:start position:0% +transplanting +test cells test stem + + align:start position:0% +test cells test stem + + + align:start position:0% +test cells test stem +cells into the + + align:start position:0% + + + + align:start position:0% + +adult and you have removed from the + + align:start position:0% + + + + align:start position:0% + +adult endogenous cells that might be + + align:start position:0% +adult endogenous cells that might be + + + align:start position:0% +adult endogenous cells that might be +competing with those stem + + align:start position:0% + + + + align:start position:0% + +cells that would include the stem cells + + align:start position:0% +cells that would include the stem cells + + + align:start position:0% +cells that would include the stem cells +we'll go through a slide in a moment I'm + + align:start position:0% +we'll go through a slide in a moment I'm + + + align:start position:0% +we'll go through a slide in a moment I'm +going to list them here another one is + + align:start position:0% +going to list them here another one is + + + align:start position:0% +going to list them here another one is +an invitro induction + + align:start position:0% + + + + align:start position:0% + +assay where you're going to take + + align:start position:0% +assay where you're going to take + + + align:start position:0% +assay where you're going to take +isolated + + align:start position:0% +isolated + + + align:start position:0% +isolated +cells and you're going to treat them + + align:start position:0% +cells and you're going to treat them + + + align:start position:0% +cells and you're going to treat them +with various inducers various signaling + + align:start position:0% +with various inducers various signaling + + + align:start position:0% +with various inducers various signaling +molecules and you're going to test and + + align:start position:0% +molecules and you're going to test and + + + align:start position:0% +molecules and you're going to test and +see what Fates those cells can + + align:start position:0% +see what Fates those cells can + + + align:start position:0% +see what Fates those cells can +acquire and a third assay is called an + + align:start position:0% +acquire and a third assay is called an + + + align:start position:0% +acquire and a third assay is called an +embryo incorporation assay + + align:start position:0% + + + + align:start position:0% + +where you're going to take cells that + + align:start position:0% +where you're going to take cells that + + + align:start position:0% +where you're going to take cells that +may be stem + + align:start position:0% +may be stem + + + align:start position:0% +may be stem +cells and you're going to test + + align:start position:0% +cells and you're going to test + + + align:start position:0% +cells and you're going to test +them in a chimeric + + align:start position:0% + + + + align:start position:0% + +embryo let's go through your next + + align:start position:0% +embryo let's go through your next + + + align:start position:0% +embryo let's go through your next +slides to discuss each of these + + align:start position:0% +slides to discuss each of these + + + align:start position:0% +slides to discuss each of these +points bone marrow transplants resulted + + align:start position:0% +points bone marrow transplants resulted + + + align:start position:0% +points bone marrow transplants resulted +in a Nobel Prize in 1990 for Eon Thomas + + align:start position:0% +in a Nobel Prize in 1990 for Eon Thomas + + + align:start position:0% +in a Nobel Prize in 1990 for Eon Thomas +and Joseph Murray it's a technique that + + align:start position:0% +and Joseph Murray it's a technique that + + + align:start position:0% +and Joseph Murray it's a technique that +say + + align:start position:0% +say + + + align:start position:0% +say +millions of lives and here how it works + + align:start position:0% +millions of lives and here how it works + + + align:start position:0% +millions of lives and here how it works +in a mouse you take the mouse and you + + align:start position:0% +in a mouse you take the mouse and you + + + align:start position:0% +in a mouse you take the mouse and you +irradiate the mouse to destroy the bone + + align:start position:0% +irradiate the mouse to destroy the bone + + + align:start position:0% +irradiate the mouse to destroy the bone +marrow and the stem cells associated + + align:start position:0% +marrow and the stem cells associated + + + align:start position:0% +marrow and the stem cells associated +with the bone marrow if it's a person to + + align:start position:0% +with the bone marrow if it's a person to + + + align:start position:0% +with the bone marrow if it's a person to +destroy the diseased burnt bone + + align:start position:0% +destroy the diseased burnt bone + + + align:start position:0% +destroy the diseased burnt bone +marrow and then you replace that bone + + align:start position:0% +marrow and then you replace that bone + + + align:start position:0% +marrow and then you replace that bone +marrow with normal bone marrow to either + + align:start position:0% +marrow with normal bone marrow to either + + + align:start position:0% +marrow with normal bone marrow to either +try to make the person better or in this + + align:start position:0% +try to make the person better or in this + + + align:start position:0% +try to make the person better or in this +case to test something about stem cells + + align:start position:0% +case to test something about stem cells + + + align:start position:0% +case to test something about stem cells +the irradiated mouse or person would die + + align:start position:0% +the irradiated mouse or person would die + + + align:start position:0% +the irradiated mouse or person would die +but the normal bone marrow will cause + + align:start position:0% +but the normal bone marrow will cause + + + align:start position:0% +but the normal bone marrow will cause +the mouse to live and if you've put stem + + align:start position:0% +the mouse to live and if you've put stem + + + align:start position:0% +the mouse to live and if you've put stem +cells into that Mouse you can start + + align:start position:0% +cells into that Mouse you can start + + + align:start position:0% +cells into that Mouse you can start +getting them out of that Mouse whose + + align:start position:0% +getting them out of that Mouse whose + + + align:start position:0% +getting them out of that Mouse whose +life you've saved and isolate more stem + + align:start position:0% +life you've saved and isolate more stem + + + align:start position:0% +life you've saved and isolate more stem +cells those kinds of assays led to the + + align:start position:0% +cells those kinds of assays led to the + + + align:start position:0% +cells those kinds of assays led to the +definition of the hematopoetic stem cell + + align:start position:0% +definition of the hematopoetic stem cell + + + align:start position:0% +definition of the hematopoetic stem cell +here it is it's a plur poent stem cell + + align:start position:0% +here it is it's a plur poent stem cell + + + align:start position:0% +here it is it's a plur poent stem cell +that gives rise to all of these + + align:start position:0% +that gives rise to all of these + + + align:start position:0% +that gives rise to all of these +different kinds of cells the immune + + align:start position:0% +different kinds of cells the immune + + + align:start position:0% +different kinds of cells the immune +cells and all of the blood cells it's a + + align:start position:0% +cells and all of the blood cells it's a + + + align:start position:0% +cells and all of the blood cells it's a +very very powerful stem cell and the the + + align:start position:0% +very very powerful stem cell and the the + + + align:start position:0% +very very powerful stem cell and the the +ability to actually make this diagram + + align:start position:0% +ability to actually make this diagram + + + align:start position:0% +ability to actually make this diagram +and say that there was a single cell + + align:start position:0% +and say that there was a single cell + + + align:start position:0% +and say that there was a single cell +that gave rise to all these different + + align:start position:0% +that gave rise to all these different + + + align:start position:0% +that gave rise to all these different +lineages was because of a titration + + align:start position:0% +lineages was because of a titration + + + align:start position:0% +lineages was because of a titration +assay where you could take these + + align:start position:0% +assay where you could take these + + + align:start position:0% +assay where you could take these +putative hematopoetic stem cells that + + align:start position:0% +putative hematopoetic stem cells that + + + align:start position:0% +putative hematopoetic stem cells that +were difficult to isolate and still + + align:start position:0% +were difficult to isolate and still + + + align:start position:0% +were difficult to isolate and still +haven't been isolated in their purity + + align:start position:0% +haven't been isolated in their purity + + + align:start position:0% +haven't been isolated in their purity +but you can titrate them down and you + + align:start position:0% +but you can titrate them down and you + + + align:start position:0% +but you can titrate them down and you +can introduce what you think is one stem + + align:start position:0% +can introduce what you think is one stem + + + align:start position:0% +can introduce what you think is one stem +cell 10 stem cells 100 stem cells and so + + align:start position:0% +cell 10 stem cells 100 stem cells and so + + + align:start position:0% +cell 10 stem cells 100 stem cells and so +on into an irradiated Mouse and ask how + + align:start position:0% +on into an irradiated Mouse and ask how + + + align:start position:0% +on into an irradiated Mouse and ask how +many stem cells does it take to + + align:start position:0% +many stem cells does it take to + + + align:start position:0% +many stem cells does it take to +repopulate the entire blood system and + + align:start position:0% +repopulate the entire blood system and + + + align:start position:0% +repopulate the entire blood system and +immune system and it turns out you have + + align:start position:0% +immune system and it turns out you have + + + align:start position:0% +immune system and it turns out you have +to mix these cells with carrier cells + + align:start position:0% +to mix these cells with carrier cells + + + align:start position:0% +to mix these cells with carrier cells +otherwise it doesn't work but it turns + + align:start position:0% +otherwise it doesn't work but it turns + + + align:start position:0% +otherwise it doesn't work but it turns +out that one cell can repopulate the + + align:start position:0% +out that one cell can repopulate the + + + align:start position:0% +out that one cell can repopulate the +entire hematopoetic system which is + + align:start position:0% +entire hematopoetic system which is + + + align:start position:0% +entire hematopoetic system which is +really extraordinary and led to the + + align:start position:0% +really extraordinary and led to the + + + align:start position:0% +really extraordinary and led to the +diagram that I showed you in the slide + + align:start position:0% +diagram that I showed you in the slide + + + align:start position:0% +diagram that I showed you in the slide +before okay here's another assay this is + + align:start position:0% +before okay here's another assay this is + + + align:start position:0% +before okay here's another assay this is +an initro induction assay and the idea + + align:start position:0% +an initro induction assay and the idea + + + align:start position:0% +an initro induction assay and the idea +here is that you start off with + + align:start position:0% +here is that you start off with + + + align:start position:0% +here is that you start off with +something which you think might be stem + + align:start position:0% +something which you think might be stem + + + align:start position:0% +something which you think might be stem +cells by various criteria and then to + + align:start position:0% +cells by various criteria and then to + + + align:start position:0% +cells by various criteria and then to +test what these cells can do you put + + align:start position:0% +test what these cells can do you put + + + align:start position:0% +test what these cells can do you put +them into plastic tissue culture dishes + + align:start position:0% +them into plastic tissue culture dishes + + + align:start position:0% +them into plastic tissue culture dishes +and you add some nutrients and so on to + + align:start position:0% +and you add some nutrients and so on to + + + align:start position:0% +and you add some nutrients and so on to +allow the cells to divide and then you + + align:start position:0% +allow the cells to divide and then you + + + align:start position:0% +allow the cells to divide and then you +add some inducers and you remember a + + align:start position:0% +add some inducers and you remember a + + + align:start position:0% +add some inducers and you remember a +couple of lectures back inducers are + + align:start position:0% +couple of lectures back inducers are + + + align:start position:0% +couple of lectures back inducers are +just ligans for various signaling + + align:start position:0% +just ligans for various signaling + + + align:start position:0% +just ligans for various signaling +systems you might add fiberblast growth + + align:start position:0% +systems you might add fiberblast growth + + + align:start position:0% +systems you might add fiberblast growth +factor to this one and retinoic acid to + + align:start position:0% +factor to this one and retinoic acid to + + + align:start position:0% +factor to this one and retinoic acid to +that one and then you ask what happens + + align:start position:0% +that one and then you ask what happens + + + align:start position:0% +that one and then you ask what happens +to the cells they will go on in general + + align:start position:0% +to the cells they will go on in general + + + align:start position:0% +to the cells they will go on in general +to differentiate into different cell + + align:start position:0% +to differentiate into different cell + + + align:start position:0% +to differentiate into different cell +types and depending on what they + + align:start position:0% +types and depending on what they + + + align:start position:0% +types and depending on what they +differentiate into you can say something + + align:start position:0% +differentiate into you can say something + + + align:start position:0% +differentiate into you can say something +about the potency of these putative stem + + align:start position:0% +about the potency of these putative stem + + + align:start position:0% +about the potency of these putative stem +cells you can't test if they're really + + align:start position:0% +cells you can't test if they're really + + + align:start position:0% +cells you can't test if they're really +stem cells but you can say something + + align:start position:0% +stem cells but you can say something + + + align:start position:0% +stem cells but you can say something +about their + + align:start position:0% +about their + + + align:start position:0% +about their +potency can do a similar experiment but + + align:start position:0% +potency can do a similar experiment but + + + align:start position:0% +potency can do a similar experiment but +in a whole + + align:start position:0% +in a whole + + + align:start position:0% +in a whole +Mouse the mouse is made from the embryo + + align:start position:0% +Mouse the mouse is made from the embryo + + + align:start position:0% +Mouse the mouse is made from the embryo +is made from a part of the the very + + align:start position:0% +is made from a part of the the very + + + align:start position:0% +is made from a part of the the very +early embryo called the Inner Cell mass + + align:start position:0% +early embryo called the Inner Cell mass + + + align:start position:0% +early embryo called the Inner Cell mass +and you can inject labeled putative stem + + align:start position:0% +and you can inject labeled putative stem + + + align:start position:0% +and you can inject labeled putative stem +cells into an early Mouse embryo into + + align:start position:0% +cells into an early Mouse embryo into + + + align:start position:0% +cells into an early Mouse embryo into +this Inner Cell Mass part of the embryo + + align:start position:0% +this Inner Cell Mass part of the embryo + + + align:start position:0% +this Inner Cell Mass part of the embryo +put it into a um a mother a a recipient + + align:start position:0% +put it into a um a mother a a recipient + + + align:start position:0% +put it into a um a mother a a recipient +mother and then ask what comes out what + + align:start position:0% +mother and then ask what comes out what + + + align:start position:0% +mother and then ask what comes out what +kind of embryo comes out of that process + + align:start position:0% +kind of embryo comes out of that process + + + align:start position:0% +kind of embryo comes out of that process +and if you see that the baby that comes + + align:start position:0% +and if you see that the baby that comes + + + align:start position:0% +and if you see that the baby that comes +out of this chimic embryo + + align:start position:0% +out of this chimic embryo + + + align:start position:0% +out of this chimic embryo +has got a green liver and green ears and + + align:start position:0% +has got a green liver and green ears and + + + align:start position:0% +has got a green liver and green ears and +green whiskers you'll know that these + + align:start position:0% +green whiskers you'll know that these + + + align:start position:0% +green whiskers you'll know that these +cells that you put into the chimeric + + align:start position:0% +cells that you put into the chimeric + + + align:start position:0% +cells that you put into the chimeric +embryo that you made the chimeric embryo + + align:start position:0% +embryo that you made the chimeric embryo + + + align:start position:0% +embryo that you made the chimeric embryo +with had the capacity to give liver ears + + align:start position:0% +with had the capacity to give liver ears + + + align:start position:0% +with had the capacity to give liver ears +and + + align:start position:0% +and + + + align:start position:0% +and +whiskers okay so this is a powerful + + align:start position:0% +whiskers okay so this is a powerful + + + align:start position:0% +whiskers okay so this is a powerful +essay to again look at the potency of + + align:start position:0% +essay to again look at the potency of + + + align:start position:0% +essay to again look at the potency of +cells not in this case the stem cell of + + align:start position:0% +cells not in this case the stem cell of + + + align:start position:0% +cells not in this case the stem cell of +of + + align:start position:0% + + + + align:start position:0% + +cells one of the things about stem + + align:start position:0% +cells one of the things about stem + + + align:start position:0% +cells one of the things about stem +cells is that you only want them to work + + align:start position:0% +cells is that you only want them to work + + + align:start position:0% +cells is that you only want them to work +when you want them to work if you cut + + align:start position:0% +when you want them to work if you cut + + + align:start position:0% +when you want them to work if you cut +yourself in the normal process of + + align:start position:0% +yourself in the normal process of + + + align:start position:0% +yourself in the normal process of +keeping your liver the right size in the + + align:start position:0% +keeping your liver the right size in the + + + align:start position:0% +keeping your liver the right size in the +normal process of keeping your heart + + align:start position:0% +normal process of keeping your heart + + + align:start position:0% +normal process of keeping your heart +muscle correct you want your stem cells + + align:start position:0% +muscle correct you want your stem cells + + + align:start position:0% +muscle correct you want your stem cells +to be working and keeping everything + + align:start position:0% +to be working and keeping everything + + + align:start position:0% +to be working and keeping everything +homeostatic you don't want them to be + + align:start position:0% +homeostatic you don't want them to be + + + align:start position:0% +homeostatic you don't want them to be +dividing out of control because then + + align:start position:0% +dividing out of control because then + + + align:start position:0% +dividing out of control because then +you'll get cancer and so something has + + align:start position:0% +you'll get cancer and so something has + + + align:start position:0% +you'll get cancer and so something has +to control what stem cells do and when + + align:start position:0% +to control what stem cells do and when + + + align:start position:0% +to control what stem cells do and when +they do it and this is a question of + + align:start position:0% + + + + align:start position:0% + +Regulation and the + + align:start position:0% + + + + align:start position:0% + +notion of a stem cell + + align:start position:0% +notion of a stem cell + + + align:start position:0% +notion of a stem cell +Niche stem cells are kept + + align:start position:0% + + + + align:start position:0% + +quiescent usually in + + align:start position:0% +quiescent usually in + + + align:start position:0% +quiescent usually in +g0 that we talked about in the cell + + align:start position:0% +g0 that we talked about in the cell + + + align:start position:0% +g0 that we talked about in the cell +cycle + + align:start position:0% +cycle + + + align:start position:0% +cycle +lecture and they're kept quiescent by + + align:start position:0% +lecture and they're kept quiescent by + + + align:start position:0% +lecture and they're kept quiescent by +signals from the surrounding cells so + + align:start position:0% +signals from the surrounding cells so + + + align:start position:0% +signals from the surrounding cells so +there's cell cell + + align:start position:0% + + + + align:start position:0% + +interaction and by + + align:start position:0% +interaction and by + + + align:start position:0% +interaction and by +signals + + align:start position:0% +signals + + + align:start position:0% +signals +from the surrounding cells and those are + + align:start position:0% +from the surrounding cells and those are + + + align:start position:0% +from the surrounding cells and those are +given a special name by stem cell + + align:start position:0% +given a special name by stem cell + + + align:start position:0% +given a special name by stem cell +biologists they're not that special but + + align:start position:0% +biologists they're not that special but + + + align:start position:0% +biologists they're not that special but +they're given a special + + align:start position:0% +they're given a special + + + align:start position:0% +they're given a special +name they're called Niche cells or the + + align:start position:0% +name they're called Niche cells or the + + + align:start position:0% +name they're called Niche cells or the +niche okay they're just surrounding + + align:start position:0% +niche okay they're just surrounding + + + align:start position:0% +niche okay they're just surrounding +cells that are secreting + + align:start position:0% +cells that are secreting + + + align:start position:0% +cells that are secreting +signals on some kind of activation you + + align:start position:0% +signals on some kind of activation you + + + align:start position:0% +signals on some kind of activation you +cut + + align:start position:0% +cut + + + align:start position:0% +cut +yourself your organ normally needs + + align:start position:0% +yourself your organ normally needs + + + align:start position:0% +yourself your organ normally needs +repair things change so on + + align:start position:0% + + + + align:start position:0% + +activation by some kind of environmental + + align:start position:0% +activation by some kind of environmental + + + align:start position:0% +activation by some kind of environmental +input local or less + + align:start position:0% +input local or less + + + align:start position:0% +input local or less +local the niche + + align:start position:0% +local the niche + + + align:start position:0% +local the niche +cells induce the stem cells to + + align:start position:0% +cells induce the stem cells to + + + align:start position:0% +cells induce the stem cells to +divide + + align:start position:0% + + + + align:start position:0% + +and they do this and they induce the + + align:start position:0% +and they do this and they induce the + + + align:start position:0% +and they do this and they induce the +stem cells to divide into a stem cell + + align:start position:0% +stem cells to divide into a stem cell + + + align:start position:0% +stem cells to divide into a stem cell +plus a progenitor which then goes + + align:start position:0% +plus a progenitor which then goes + + + align:start position:0% +plus a progenitor which then goes +on to do all the things that I + + align:start position:0% +on to do all the things that I + + + align:start position:0% +on to do all the things that I +diagrammed that progenitors do on the + + align:start position:0% +diagrammed that progenitors do on the + + + align:start position:0% +diagrammed that progenitors do on the +first + + align:start position:0% +first + + + align:start position:0% +first +board and the niche cells do this + + align:start position:0% +board and the niche cells do this + + + align:start position:0% +board and the niche cells do this +because they've changed their + + align:start position:0% + + + + align:start position:0% + +signaling + + align:start position:0% + + + + align:start position:0% + +this is yet another use or very related + + align:start position:0% +this is yet another use or very related + + + align:start position:0% +this is yet another use or very related +use of the notion of cell cell signaling + + align:start position:0% +use of the notion of cell cell signaling + + + align:start position:0% +use of the notion of cell cell signaling +in controlling life here's a diagram + + align:start position:0% +in controlling life here's a diagram + + + align:start position:0% +in controlling life here's a diagram +here are Niche cells you don't have this + + align:start position:0% +here are Niche cells you don't have this + + + align:start position:0% +here are Niche cells you don't have this +just look on the screen surrounding + + align:start position:0% +just look on the screen surrounding + + + align:start position:0% +just look on the screen surrounding +cells maintaining stem cells quiet when + + align:start position:0% +cells maintaining stem cells quiet when + + + align:start position:0% +cells maintaining stem cells quiet when +there's an Environ environmental input + + align:start position:0% +there's an Environ environmental input + + + align:start position:0% +there's an Environ environmental input +the niche cells change they activate the + + align:start position:0% +the niche cells change they activate the + + + align:start position:0% +the niche cells change they activate the +stem cells to divide and form more stem + + align:start position:0% +stem cells to divide and form more stem + + + align:start position:0% +stem cells to divide and form more stem +cells and progenitor + + align:start position:0% + + + + align:start position:0% + +cells one really fantastic example of + + align:start position:0% +cells one really fantastic example of + + + align:start position:0% +cells one really fantastic example of +the niche and the interaction between + + align:start position:0% +the niche and the interaction between + + + align:start position:0% +the niche and the interaction between +stem cells and the niche is in the hair + + align:start position:0% +stem cells and the niche is in the hair + + + align:start position:0% +stem cells and the niche is in the hair +this is from my colleague elain fuches + + align:start position:0% +this is from my colleague elain fuches + + + align:start position:0% +this is from my colleague elain fuches +at Rockefeller who over many years has + + align:start position:0% +at Rockefeller who over many years has + + + align:start position:0% +at Rockefeller who over many years has +figured out that in the hair follicle + + align:start position:0% +figured out that in the hair follicle + + + align:start position:0% +figured out that in the hair follicle +this is the hair sticking out of the + + align:start position:0% +this is the hair sticking out of the + + + align:start position:0% +this is the hair sticking out of the +skin in the hair there is a small group + + align:start position:0% +skin in the hair there is a small group + + + align:start position:0% +skin in the hair there is a small group +of cells on one side of the hair shaft + + align:start position:0% +of cells on one side of the hair shaft + + + align:start position:0% +of cells on one side of the hair shaft +called The Bulge cells and these bulge + + align:start position:0% +called The Bulge cells and these bulge + + + align:start position:0% +called The Bulge cells and these bulge +cells are the stem + + align:start position:0% +cells are the stem + + + align:start position:0% +cells are the stem +cells her investigators isolated these + + align:start position:0% +cells her investigators isolated these + + + align:start position:0% +cells her investigators isolated these +bulge cells and did the following + + align:start position:0% +bulge cells and did the following + + + align:start position:0% +bulge cells and did the following +experiment to show that they were hair + + align:start position:0% +experiment to show that they were hair + + + align:start position:0% +experiment to show that they were hair +stem cells there's a kind of a mouse + + align:start position:0% +stem cells there's a kind of a mouse + + + align:start position:0% +stem cells there's a kind of a mouse +called a nude mouse that has a very bad + + align:start position:0% +called a nude mouse that has a very bad + + + align:start position:0% +called a nude mouse that has a very bad +immune system so it's useful for immune + + align:start position:0% +immune system so it's useful for immune + + + align:start position:0% +immune system so it's useful for immune +system experiments but it also has no + + align:start position:0% +system experiments but it also has no + + + align:start position:0% +system experiments but it also has no +hair and you can do a transplant into + + align:start position:0% +hair and you can do a transplant into + + + align:start position:0% +hair and you can do a transplant into +this mouse of these bulge cells and you + + align:start position:0% +this mouse of these bulge cells and you + + + align:start position:0% +this mouse of these bulge cells and you +get little Tufts of hair growing where + + align:start position:0% +get little Tufts of hair growing where + + + align:start position:0% +get little Tufts of hair growing where +the rest of the mouse is nude and you've + + align:start position:0% +the rest of the mouse is nude and you've + + + align:start position:0% +the rest of the mouse is nude and you've +done a careful experiment where you've + + align:start position:0% +done a careful experiment where you've + + + align:start position:0% +done a careful experiment where you've +labeled the cells you've transplanted in + + align:start position:0% +labeled the cells you've transplanted in + + + align:start position:0% +labeled the cells you've transplanted in +so that you can show that they actually + + align:start position:0% +so that you can show that they actually + + + align:start position:0% +so that you can show that they actually +came from the transplanted tissue and + + align:start position:0% +came from the transplanted tissue and + + + align:start position:0% +came from the transplanted tissue and +not from the mouse the nude Mouse tissue + + align:start position:0% +not from the mouse the nude Mouse tissue + + + align:start position:0% +not from the mouse the nude Mouse tissue +and you can do that because you label + + align:start position:0% +and you can do that because you label + + + align:start position:0% +and you can do that because you label +them with gfp and they're green so + + align:start position:0% +them with gfp and they're green so + + + align:start position:0% +them with gfp and they're green so +there's the green hair and it shows you + + align:start position:0% +there's the green hair and it shows you + + + align:start position:0% +there's the green hair and it shows you +that these bulge cells are stem + + align:start position:0% +that these bulge cells are stem + + + align:start position:0% +that these bulge cells are stem +cells during the life of a hair your + + align:start position:0% +cells during the life of a hair your + + + align:start position:0% +cells during the life of a hair your +hair has a life we discussed four years + + align:start position:0% +hair has a life we discussed four years + + + align:start position:0% +hair has a life we discussed four years +on your hair head during the life of a + + align:start position:0% +on your hair head during the life of a + + + align:start position:0% +on your hair head during the life of a +hair the Bulge cells and the niche cells + + align:start position:0% +hair the Bulge cells and the niche cells + + + align:start position:0% +hair the Bulge cells and the niche cells +are of different are in different places + + align:start position:0% +are of different are in different places + + + align:start position:0% +are of different are in different places +and depending on whether they're + + align:start position:0% +and depending on whether they're + + + align:start position:0% +and depending on whether they're +touching or far apart from one another + + align:start position:0% +touching or far apart from one another + + + align:start position:0% +touching or far apart from one another +there's induction of hair growth or not + + align:start position:0% +there's induction of hair growth or not + + + align:start position:0% +there's induction of hair growth or not +so at a particular stage of the hair + + align:start position:0% +so at a particular stage of the hair + + + align:start position:0% +so at a particular stage of the hair +cycle this is called the hair cycle look + + align:start position:0% +cycle this is called the hair cycle look + + + align:start position:0% +cycle this is called the hair cycle look +on the bottom of the screen here the + + align:start position:0% +on the bottom of the screen here the + + + align:start position:0% +on the bottom of the screen here the +Bulge cells and a group of cells called + + align:start position:0% +Bulge cells and a group of cells called + + + align:start position:0% +Bulge cells and a group of cells called +the dermal pillar that lies right at the + + align:start position:0% +the dermal pillar that lies right at the + + + align:start position:0% +the dermal pillar that lies right at the +bottom of the hair shaft are touch ing + + align:start position:0% +bottom of the hair shaft are touch ing + + + align:start position:0% +bottom of the hair shaft are touch ing +one another and at that point a + + align:start position:0% +one another and at that point a + + + align:start position:0% +one another and at that point a +particular signaling pathway called the + + align:start position:0% +particular signaling pathway called the + + + align:start position:0% +particular signaling pathway called the +wi pathway is activated and these dermal + + align:start position:0% +wi pathway is activated and these dermal + + + align:start position:0% +wi pathway is activated and these dermal +pil cells tell the buge Bulge cells to + + align:start position:0% +pil cells tell the buge Bulge cells to + + + align:start position:0% +pil cells tell the buge Bulge cells to +start dividing and start making a new + + align:start position:0% +start dividing and start making a new + + + align:start position:0% +start dividing and start making a new +hair shaft after that's happened the + + align:start position:0% +hair shaft after that's happened the + + + align:start position:0% +hair shaft after that's happened the +Bulge cells move away from the dermal + + align:start position:0% +Bulge cells move away from the dermal + + + align:start position:0% +Bulge cells move away from the dermal +pil cells here they are during growth + + align:start position:0% +pil cells here they are during growth + + + align:start position:0% +pil cells here they are during growth +the growth period you see the Bulge and + + align:start position:0% +the growth period you see the Bulge and + + + align:start position:0% +the growth period you see the Bulge and +the dermal pil cells are no longer + + align:start position:0% +the dermal pil cells are no longer + + + align:start position:0% +the dermal pil cells are no longer +touching at this point the stem cells + + align:start position:0% +touching at this point the stem cells + + + align:start position:0% +touching at this point the stem cells +become quiescent and there are enough + + align:start position:0% +become quiescent and there are enough + + + align:start position:0% +become quiescent and there are enough +progenitor cells in the hair shaft to + + align:start position:0% +progenitor cells in the hair shaft to + + + align:start position:0% +progenitor cells in the hair shaft to +give you formation of the hair and then + + align:start position:0% +give you formation of the hair and then + + + align:start position:0% +give you formation of the hair and then +the stem cells remain quiescent until + + align:start position:0% +the stem cells remain quiescent until + + + align:start position:0% +the stem cells remain quiescent until +the next hair cycle starts and they get + + align:start position:0% +the next hair cycle starts and they get + + + align:start position:0% +the next hair cycle starts and they get +in contact with the dommal pillar again + + align:start position:0% +in contact with the dommal pillar again + + + align:start position:0% +in contact with the dommal pillar again +and start making new hair this is a + + align:start position:0% +and start making new hair this is a + + + align:start position:0% +and start making new hair this is a +really beautiful story that's shown us + + align:start position:0% +really beautiful story that's shown us + + + align:start position:0% +really beautiful story that's shown us +quite clearly how the niche cells can + + align:start position:0% +quite clearly how the niche cells can + + + align:start position:0% +quite clearly how the niche cells can +control these stem + + align:start position:0% +control these stem + + + align:start position:0% +control these stem +cells all right so let's spend the last + + align:start position:0% +cells all right so let's spend the last + + + align:start position:0% +cells all right so let's spend the last +minutes talking about + + align:start position:0% +minutes talking about + + + align:start position:0% +minutes talking about +Therapeutics + + align:start position:0% + + + + align:start position:0% + +here's the + + align:start position:0% +here's the + + + align:start position:0% +here's the +dream you know the dream is that you + + align:start position:0% +dream you know the dream is that you + + + align:start position:0% +dream you know the dream is that you +have a stem cell population for every + + align:start position:0% +have a stem cell population for every + + + align:start position:0% +have a stem cell population for every +organ in the + + align:start position:0% +organ in the + + + align:start position:0% +organ in the +body including things like + + align:start position:0% +body including things like + + + align:start position:0% +body including things like +limbs such that if your limb gets + + align:start position:0% +limbs such that if your limb gets + + + align:start position:0% +limbs such that if your limb gets +severed or your heart becomes really + + align:start position:0% +severed or your heart becomes really + + + align:start position:0% +severed or your heart becomes really +diseased Ed or your spinal cord is + + align:start position:0% +diseased Ed or your spinal cord is + + + align:start position:0% +diseased Ed or your spinal cord is +injured and you can't walk anymore that + + align:start position:0% +injured and you can't walk anymore that + + + align:start position:0% +injured and you can't walk anymore that +you can just inject into a patient the + + align:start position:0% +you can just inject into a patient the + + + align:start position:0% +you can just inject into a patient the +correct stem cells and everything gets + + align:start position:0% +correct stem cells and everything gets + + + align:start position:0% +correct stem cells and everything gets +repaired that's the dream and that's + + align:start position:0% +repaired that's the dream and that's + + + align:start position:0% +repaired that's the dream and that's +really the Holy Grail of what thousands + + align:start position:0% +really the Holy Grail of what thousands + + + align:start position:0% +really the Holy Grail of what thousands +and thousands of investigators are going + + align:start position:0% +and thousands of investigators are going + + + align:start position:0% +and thousands of investigators are going +after and it's given precedence by bone + + align:start position:0% +after and it's given precedence by bone + + + align:start position:0% +after and it's given precedence by bone +marrow transplants which really are very + + align:start position:0% +marrow transplants which really are very + + + align:start position:0% +marrow transplants which really are very +successful turns out that it's kind of + + align:start position:0% +successful turns out that it's kind of + + + align:start position:0% +successful turns out that it's kind of +tough it's tough because these are ad + + align:start position:0% +tough it's tough because these are ad + + + align:start position:0% +tough it's tough because these are ad +stem cells are really rare the + + align:start position:0% +stem cells are really rare the + + + align:start position:0% +stem cells are really rare the +hematopoetic stem cells are special + + align:start position:0% +hematopoetic stem cells are special + + + align:start position:0% +hematopoetic stem cells are special +because they're kind of liquid they're + + align:start position:0% +because they're kind of liquid they're + + + align:start position:0% +because they're kind of liquid they're +single cells they're not attached to + + align:start position:0% +single cells they're not attached to + + + align:start position:0% +single cells they're not attached to +anything and they are relatively easy to + + align:start position:0% +anything and they are relatively easy to + + + align:start position:0% +anything and they are relatively easy to +identify but other stem cells are very + + align:start position:0% +identify but other stem cells are very + + + align:start position:0% +identify but other stem cells are very +difficult so the + + align:start position:0% +difficult so the + + + align:start position:0% +difficult so the +idea is that you inject stem + + align:start position:0% + + + + align:start position:0% + +cells to repair a damaged + + align:start position:0% + + + + align:start position:0% + +organ + + align:start position:0% + + + + align:start position:0% + +you need stem cells of the correct + + align:start position:0% +you need stem cells of the correct + + + align:start position:0% +you need stem cells of the correct +potency otherwise you're not going to + + align:start position:0% +potency otherwise you're not going to + + + align:start position:0% +potency otherwise you're not going to +repair the specific + + align:start position:0% + + + + align:start position:0% + +organ but adult stem cells are very + + align:start position:0% + + + + align:start position:0% + +rare and so the quest has been to find + + align:start position:0% +rare and so the quest has been to find + + + align:start position:0% +rare and so the quest has been to find +some kind of substitute for adult stem + + align:start position:0% +some kind of substitute for adult stem + + + align:start position:0% +some kind of substitute for adult stem +cells + + align:start position:0% + + + + align:start position:0% + +and those + + align:start position:0% + + + + align:start position:0% + +substitutes come in two + + align:start position:0% +substitutes come in two + + + align:start position:0% +substitutes come in two +flavors one Are embryonic stem + + align:start position:0% + + + + align:start position:0% + +cells abbreviated + + align:start position:0% +cells abbreviated + + + align:start position:0% +cells abbreviated +esc's embryonic stem cells are cells + + align:start position:0% +esc's embryonic stem cells are cells + + + align:start position:0% +esc's embryonic stem cells are cells +that grow from the Inner Cell mass of an + + align:start position:0% +that grow from the Inner Cell mass of an + + + align:start position:0% +that grow from the Inner Cell mass of an +early mamalian embryo and you can grow + + align:start position:0% +early mamalian embryo and you can grow + + + align:start position:0% +early mamalian embryo and you can grow +from the them groups of cells that will + + align:start position:0% +from the them groups of cells that will + + + align:start position:0% +from the them groups of cells that will +keep growing in the laboratory for a + + align:start position:0% +keep growing in the laboratory for a + + + align:start position:0% +keep growing in the laboratory for a +long time and have variable potency so + + align:start position:0% +long time and have variable potency so + + + align:start position:0% +long time and have variable potency so +the embryon stem cells are + + align:start position:0% +the embryon stem cells are + + + align:start position:0% +the embryon stem cells are +derived from the Inner Cell + + align:start position:0% +derived from the Inner Cell + + + align:start position:0% +derived from the Inner Cell +mass of an early mamalian + + align:start position:0% + + + + align:start position:0% + +embryo human in the case of + + align:start position:0% +embryo human in the case of + + + align:start position:0% +embryo human in the case of +human + + align:start position:0% +human + + + align:start position:0% +human +and you grow + + align:start position:0% + + + + align:start position:0% + +out so-called ESC + + align:start position:0% +out so-called ESC + + + align:start position:0% +out so-called ESC +lines which means that these cells grow + + align:start position:0% + + + + align:start position:0% + +continuously in + + align:start position:0% + + + + align:start position:0% + +culture and each embryonic stem cell + + align:start position:0% +culture and each embryonic stem cell + + + align:start position:0% +culture and each embryonic stem cell +line has a unique potency + + align:start position:0% + + + + align:start position:0% + +and can be used to do different things + + align:start position:0% +and can be used to do different things + + + align:start position:0% +and can be used to do different things +in terms of theoretical repair if you + + align:start position:0% +in terms of theoretical repair if you + + + align:start position:0% +in terms of theoretical repair if you +look on your next handout the idea is + + align:start position:0% +look on your next handout the idea is + + + align:start position:0% +look on your next handout the idea is +that you take this Inner Cell Mass you + + align:start position:0% +that you take this Inner Cell Mass you + + + align:start position:0% +that you take this Inner Cell Mass you +plate the cells as single + + align:start position:0% +plate the cells as single + + + align:start position:0% +plate the cells as single +cells they grow and grow and + + align:start position:0% +cells they grow and grow and + + + align:start position:0% +cells they grow and grow and +grow and if you treat them with various + + align:start position:0% +grow and if you treat them with various + + + align:start position:0% +grow and if you treat them with various +indues you can get them to become hot or + + align:start position:0% +indues you can get them to become hot or + + + align:start position:0% +indues you can get them to become hot or +neuron genitors inject those into + + align:start position:0% +neuron genitors inject those into + + + align:start position:0% +neuron genitors inject those into +animals and make them better there's + + align:start position:0% +animals and make them better there's + + + align:start position:0% +animals and make them better there's +some issues with embryonic stem + + align:start position:0% +some issues with embryonic stem + + + align:start position:0% +some issues with embryonic stem +cells and the + + align:start position:0% +cells and the + + + align:start position:0% +cells and the +problems are + + align:start position:0% + + + + align:start position:0% + +twofold one is + + align:start position:0% +twofold one is + + + align:start position:0% +twofold one is +ethical in + + align:start position:0% +ethical in + + + align:start position:0% +ethical in +that you have to harest human embryos + + align:start position:0% +that you have to harest human embryos + + + align:start position:0% +that you have to harest human embryos +you have to obtain and harvest human + + align:start position:0% +you have to obtain and harvest human + + + align:start position:0% +you have to obtain and harvest human +embryos to get these human stem cells + + align:start position:0% + + + + align:start position:0% + +lines and currently you're really not + + align:start position:0% +lines and currently you're really not + + + align:start position:0% +lines and currently you're really not +allowed to do much human embryo work to + + align:start position:0% +allowed to do much human embryo work to + + + align:start position:0% +allowed to do much human embryo work to +obtain human stem cells but the second + + align:start position:0% +obtain human stem cells but the second + + + align:start position:0% +obtain human stem cells but the second +even if you were is that these cells are + + align:start position:0% +even if you were is that these cells are + + + align:start position:0% +even if you were is that these cells are +non + + align:start position:0% +non + + + align:start position:0% +non +autologous they do not + + align:start position:0% +autologous they do not + + + align:start position:0% +autologous they do not +match the + + align:start position:0% +match the + + + align:start position:0% +match the +person into which you're putting them + + align:start position:0% +person into which you're putting them + + + align:start position:0% +person into which you're putting them +they do not match the immune system of + + align:start position:0% +they do not match the immune system of + + + align:start position:0% +they do not match the immune system of +the recipient and so they'll be rejected + + align:start position:0% +the recipient and so they'll be rejected + + + align:start position:0% +the recipient and so they'll be rejected +and it's the same as an organ transplant + + align:start position:0% +and it's the same as an organ transplant + + + align:start position:0% +and it's the same as an organ transplant +you have lots of problems of + + align:start position:0% +you have lots of problems of + + + align:start position:0% +you have lots of problems of +rejection so the latest thing that is + + align:start position:0% +rejection so the latest thing that is + + + align:start position:0% +rejection so the latest thing that is +very exciting and wonderful and + + align:start position:0% +very exciting and wonderful and + + + align:start position:0% +very exciting and wonderful and +potentially might be very useful is the + + align:start position:0% +potentially might be very useful is the + + + align:start position:0% +potentially might be very useful is the +use + + align:start position:0% + + + + align:start position:0% + +of things called IPS cells + + align:start position:0% + + + + align:start position:0% + +in which you convert adult + + align:start position:0% + + + + align:start position:0% + +cells into stem + + align:start position:0% +cells into stem + + + align:start position:0% +cells into stem +cells and you do so as I'll Tell You by + + align:start position:0% +cells and you do so as I'll Tell You by + + + align:start position:0% +cells and you do so as I'll Tell You by +adding some transcription factors to + + align:start position:0% +adding some transcription factors to + + + align:start position:0% +adding some transcription factors to +them the advantage of these is that they + + align:start position:0% +them the advantage of these is that they + + + align:start position:0% +them the advantage of these is that they +are + + align:start position:0% +are + + + align:start position:0% +are +self cells you could do them from + + align:start position:0% +self cells you could do them from + + + align:start position:0% +self cells you could do them from +yourself the disadvantage is that + + align:start position:0% +yourself the disadvantage is that + + + align:start position:0% +yourself the disadvantage is that +they're really not proven + + align:start position:0% +they're really not proven + + + align:start position:0% +they're really not proven +and there are still I will just say lots + + align:start position:0% +and there are still I will just say lots + + + align:start position:0% +and there are still I will just say lots +of + + align:start position:0% + + + + align:start position:0% + +problems but there are a lot of people + + align:start position:0% +problems but there are a lot of people + + + align:start position:0% +problems but there are a lot of people +including some of the top investigators + + align:start position:0% +including some of the top investigators + + + align:start position:0% +including some of the top investigators +in the world working on these IPS cells + + align:start position:0% +in the world working on these IPS cells + + + align:start position:0% +in the world working on these IPS cells +so look at your last + + align:start position:0% +so look at your last + + + align:start position:0% +so look at your last +handout we will remove + + align:start position:0% +handout we will remove + + + align:start position:0% +handout we will remove +our interesting calendar reminders there + + align:start position:0% +our interesting calendar reminders there + + + align:start position:0% +our interesting calendar reminders there +adult differentiated cells which are + + align:start position:0% +adult differentiated cells which are + + + align:start position:0% +adult differentiated cells which are +unipotent can be treated with three or + + align:start position:0% +unipotent can be treated with three or + + + align:start position:0% +unipotent can be treated with three or +four transcription factors and finding + + align:start position:0% +four transcription factors and finding + + + align:start position:0% +four transcription factors and finding +these transcription factors was the key + + align:start position:0% +these transcription factors was the key + + + align:start position:0% +these transcription factors was the key +and once you express these transcription + + align:start position:0% +and once you express these transcription + + + align:start position:0% +and once you express these transcription +factors in these adult cells like magic + + align:start position:0% +factors in these adult cells like magic + + + align:start position:0% +factors in these adult cells like magic +they become stem cells it really was + + align:start position:0% +they become stem cells it really was + + + align:start position:0% +they become stem cells it really was +like + + align:start position:0% +like + + + align:start position:0% +like +magic you can test the potency of these + + align:start position:0% +magic you can test the potency of these + + + align:start position:0% +magic you can test the potency of these +stem cells in the same way we discussed + + align:start position:0% +stem cells in the same way we discussed + + + align:start position:0% +stem cells in the same way we discussed +and professor yamanaka in Japan and + + align:start position:0% +and professor yamanaka in Japan and + + + align:start position:0% +and professor yamanaka in Japan and +Professor yanish here have shown that + + align:start position:0% +Professor yanish here have shown that + + + align:start position:0% +Professor yanish here have shown that +these are really very powerful cells + + align:start position:0% +these are really very powerful cells + + + align:start position:0% +these are really very powerful cells +and those are the promise of the future + + align:start position:0% +and those are the promise of the future + + + align:start position:0% +and those are the promise of the future +and we'll stop there and meet on + + align:start position:0% + + + + align:start position:0% + +Friday \ No newline at end of file diff --git a/6BPDK1b3jDg.txt b/6BPDK1b3jDg.txt new file mode 100644 index 0000000000000000000000000000000000000000..f4d6f3f78d310de9a0a5a2e5629ad27bc5dd4226 --- /dev/null +++ b/6BPDK1b3jDg.txt @@ -0,0 +1,8651 @@ +align:start position:0% + +so the big issue that we're trying I was + + align:start position:0% +so the big issue that we're trying I was + + + align:start position:0% +so the big issue that we're trying I was +trying to take on yesterday and this is + + align:start position:0% +trying to take on yesterday and this is + + + align:start position:0% +trying to take on yesterday and this is +of really fundamental importance to + + align:start position:0% +of really fundamental importance to + + + align:start position:0% +of really fundamental importance to +biology is you saw from that that + + align:start position:0% +biology is you saw from that that + + + align:start position:0% +biology is you saw from that that +molecular composition of cells 80% water + + align:start position:0% +molecular composition of cells 80% water + + + align:start position:0% +molecular composition of cells 80% water +of the rest of it about 50% of what + + align:start position:0% +of the rest of it about 50% of what + + + align:start position:0% +of the rest of it about 50% of what +there what's there by mass is is protein + + align:start position:0% +there what's there by mass is is protein + + + align:start position:0% +there what's there by mass is is protein +proteins do most of the really + + align:start position:0% +proteins do most of the really + + + align:start position:0% +proteins do most of the really +interesting stuff in the cell they're + + align:start position:0% +interesting stuff in the cell they're + + + align:start position:0% +interesting stuff in the cell they're +the ones that are able to catalyze + + align:start position:0% +the ones that are able to catalyze + + + align:start position:0% +the ones that are able to catalyze +specific chemical reactions with lets + + align:start position:0% +specific chemical reactions with lets + + + align:start position:0% +specific chemical reactions with lets +all this amazing chemistry + + align:start position:0% +all this amazing chemistry + + + align:start position:0% +all this amazing chemistry +Tak uh that's needed for Life take place + + align:start position:0% +Tak uh that's needed for Life take place + + + align:start position:0% +Tak uh that's needed for Life take place +at physiological conditions um their + + align:start position:0% +at physiological conditions um their + + + align:start position:0% +at physiological conditions um their +structural components of the cells they + + align:start position:0% +structural components of the cells they + + + align:start position:0% +structural components of the cells they +are all kinds of amazing machines I've + + align:start position:0% +are all kinds of amazing machines I've + + + align:start position:0% +are all kinds of amazing machines I've +showed you the little flugel motor that + + align:start position:0% +showed you the little flugel motor that + + + align:start position:0% +showed you the little flugel motor that +turns it but that's just one of many + + align:start position:0% +turns it but that's just one of many + + + align:start position:0% +turns it but that's just one of many +many nanom machines that are necessary + + align:start position:0% +many nanom machines that are necessary + + + align:start position:0% +many nanom machines that are necessary +uh for life they have in Exquisite + + align:start position:0% +uh for life they have in Exquisite + + + align:start position:0% +uh for life they have in Exquisite +specificity when you get sick and you + + align:start position:0% +specificity when you get sick and you + + + align:start position:0% +specificity when you get sick and you +get an immune response you develop + + align:start position:0% +get an immune response you develop + + + align:start position:0% +get an immune response you develop +antibodies and other cells that are able + + align:start position:0% +antibodies and other cells that are able + + + align:start position:0% +antibodies and other cells that are able +to rec recognize exactly the some piece + + align:start position:0% +to rec recognize exactly the some piece + + + align:start position:0% +to rec recognize exactly the some piece +of that virus or or + + align:start position:0% +of that virus or or + + + align:start position:0% +of that virus or or +um or bacterium that's infected you and + + align:start position:0% +um or bacterium that's infected you and + + + align:start position:0% +um or bacterium that's infected you and +mount an immune response but all of the + + align:start position:0% +mount an immune response but all of the + + + align:start position:0% +mount an immune response but all of the +things that are doing that are + + align:start position:0% +things that are doing that are + + + align:start position:0% +things that are doing that are +proteins and the sort of most of you I + + align:start position:0% +proteins and the sort of most of you I + + + align:start position:0% +proteins and the sort of most of you I +think know that we've sort of said that + + align:start position:0% +think know that we've sort of said that + + + align:start position:0% +think know that we've sort of said that +amino acids are just a + + align:start position:0% +amino acids are just a + + + align:start position:0% +amino acids are just a +chain of one amino acid joined to + + align:start position:0% +chain of one amino acid joined to + + + align:start position:0% +chain of one amino acid joined to +another amino + + align:start position:0% +another amino + + + align:start position:0% +another amino +acid to another amino + + align:start position:0% +acid to another amino + + + align:start position:0% +acid to another amino +acid and then and and so on and the + + align:start position:0% +acid and then and and so on and the + + + align:start position:0% +acid and then and and so on and the +what's so the backbone that peptide bond + + align:start position:0% +what's so the backbone that peptide bond + + + align:start position:0% +what's so the backbone that peptide bond +that I showed the other day is + + align:start position:0% +that I showed the other day is + + + align:start position:0% +that I showed the other day is +absolutely regular piece of backbone and + + align:start position:0% +absolutely regular piece of backbone and + + + align:start position:0% +absolutely regular piece of backbone and +what gives the the + + align:start position:0% +what gives the the + + + align:start position:0% +what gives the the +uh the thing the amino acids their + + align:start position:0% +uh the thing the amino acids their + + + align:start position:0% +uh the thing the amino acids their +character is the side chain that hangs + + align:start position:0% +character is the side chain that hangs + + + align:start position:0% +character is the side chain that hangs +off and you'll have different side + + align:start position:0% +off and you'll have different side + + + align:start position:0% +off and you'll have different side +chains hanging off depending on what the + + align:start position:0% +chains hanging off depending on what the + + + align:start position:0% +chains hanging off depending on what the +amino acid is and and you will not have + + align:start position:0% +amino acid is and and you will not have + + + align:start position:0% +amino acid is and and you will not have +to memorize all of those uh structures + + align:start position:0% +to memorize all of those uh structures + + + align:start position:0% +to memorize all of those uh structures +but the important thing is that these + + align:start position:0% +but the important thing is that these + + + align:start position:0% +but the important thing is that these +various amino acids fit into chemical + + align:start position:0% +various amino acids fit into chemical + + + align:start position:0% +various amino acids fit into chemical +categories that give them properties + + align:start position:0% +categories that give them properties + + + align:start position:0% +categories that give them properties +they either have a plus charge and + + align:start position:0% +they either have a plus charge and + + + align:start position:0% +they either have a plus charge and +negative charge um they're hydrophobic + + align:start position:0% +negative charge um they're hydrophobic + + + align:start position:0% +negative charge um they're hydrophobic +they don't like to with water they're + + align:start position:0% +they don't like to with water they're + + + align:start position:0% +they don't like to with water they're +polar they can't interact with water and + + align:start position:0% +polar they can't interact with water and + + + align:start position:0% +polar they can't interact with water and +so on and it's clear to you clear from a + + align:start position:0% +so on and it's clear to you clear from a + + + align:start position:0% +so on and it's clear to you clear from a +couple of your comments some of you why + + align:start position:0% +couple of your comments some of you why + + + align:start position:0% +couple of your comments some of you why +are we going through all of this well + + align:start position:0% +are we going through all of this well + + + align:start position:0% +are we going through all of this well +the reason we're going through all of + + align:start position:0% +the reason we're going through all of + + + align:start position:0% +the reason we're going through all of +this is all amino acids look like this + + align:start position:0% +this is all amino acids look like this + + + align:start position:0% +this is all amino acids look like this +it doesn't matter if they're going to be + + align:start position:0% +it doesn't matter if they're going to be + + + align:start position:0% +it doesn't matter if they're going to be +an enzyme part of a motor a structural + + align:start position:0% +an enzyme part of a motor a structural + + + align:start position:0% +an enzyme part of a motor a structural +part of your cells they all consist of + + align:start position:0% +part of your cells they all consist of + + + align:start position:0% +part of your cells they all consist of +the same backbone made up of those 20 + + align:start position:0% +the same backbone made up of those 20 + + + align:start position:0% +the same backbone made up of those 20 +amino acids and what gives the makes uh + + align:start position:0% +amino acids and what gives the makes uh + + + align:start position:0% +amino acids and what gives the makes uh +um the proteins so important is the + + align:start position:0% +um the proteins so important is the + + + align:start position:0% +um the proteins so important is the +ultimate three-dimensional structure I'm + + align:start position:0% +ultimate three-dimensional structure I'm + + + align:start position:0% +ultimate three-dimensional structure I'm +not sure what the sound + + align:start position:0% +not sure what the sound + + + align:start position:0% +not sure what the sound +is okay let's try standing back here um + + align:start position:0% +is okay let's try standing back here um + + + align:start position:0% +is okay let's try standing back here um +uh what gives the uh all these proteins + + align:start position:0% +uh what gives the uh all these proteins + + + align:start position:0% +uh what gives the uh all these proteins +their individual character is how this + + align:start position:0% +their individual character is how this + + + align:start position:0% +their individual character is how this +chain of amino acids you could just + + align:start position:0% +chain of amino acids you could just + + + align:start position:0% +chain of amino acids you could just +think of them like this folds up into + + align:start position:0% +think of them like this folds up into + + + align:start position:0% +think of them like this folds up into +some three-dimensional structure that + + align:start position:0% +some three-dimensional structure that + + + align:start position:0% +some three-dimensional structure that +ultimately is able to to do the + + align:start position:0% +ultimately is able to to do the + + + align:start position:0% +ultimately is able to to do the +biological function that we're um we're + + align:start position:0% +biological function that we're um we're + + + align:start position:0% +biological function that we're um we're +trying to understand and one of the real + + align:start position:0% +trying to understand and one of the real + + + align:start position:0% +trying to understand and one of the real +holy Grails still in biology is how to + + align:start position:0% +holy Grails still in biology is how to + + + align:start position:0% +holy Grails still in biology is how to +look at the sequence of amino acids that + + align:start position:0% +look at the sequence of amino acids that + + + align:start position:0% +look at the sequence of amino acids that +constitute a protein and figure out what + + align:start position:0% +constitute a protein and figure out what + + + align:start position:0% +constitute a protein and figure out what +the three-dimensional structure is it's + + align:start position:0% +the three-dimensional structure is it's + + + align:start position:0% +the three-dimensional structure is it's +one of the Holy Grails that hasn't been + + align:start position:0% +one of the Holy Grails that hasn't been + + + align:start position:0% +one of the Holy Grails that hasn't been +solved one of you may have a key Insight + + align:start position:0% +solved one of you may have a key Insight + + + align:start position:0% +solved one of you may have a key Insight +that that will solve this if we could do + + align:start position:0% +that that will solve this if we could do + + + align:start position:0% +that that will solve this if we could do +that uh would really be a huge Advance + + align:start position:0% +that uh would really be a huge Advance + + + align:start position:0% +that uh would really be a huge Advance +because what you can get out of the + + align:start position:0% +because what you can get out of the + + + align:start position:0% +because what you can get out of the +genome uh sequences is you can read the + + align:start position:0% +genome uh sequences is you can read the + + + align:start position:0% +genome uh sequences is you can read the +sequence of every Gene and you can + + align:start position:0% +sequence of every Gene and you can + + + align:start position:0% +sequence of every Gene and you can +predict the sequence of amino acids in + + align:start position:0% +predict the sequence of amino acids in + + + align:start position:0% +predict the sequence of amino acids in +the protein but all it tells you is the + + align:start position:0% +the protein but all it tells you is the + + + align:start position:0% +the protein but all it tells you is the +linear the linear sequence of the uh + + align:start position:0% +linear the linear sequence of the uh + + + align:start position:0% +linear the linear sequence of the uh +amino acids it doesn't tell you what the + + align:start position:0% +amino acids it doesn't tell you what the + + + align:start position:0% +amino acids it doesn't tell you what the +three-dimensional structure is and how + + align:start position:0% +three-dimensional structure is and how + + + align:start position:0% +three-dimensional structure is and how +it gets how an amino acid gets from a + + align:start position:0% +it gets how an amino acid gets from a + + + align:start position:0% +it gets how an amino acid gets from a +sort of floppy chain in the linear + + align:start position:0% +sort of floppy chain in the linear + + + align:start position:0% +sort of floppy chain in the linear +structure to the three-dimensional thing + + align:start position:0% +structure to the three-dimensional thing + + + align:start position:0% +structure to the three-dimensional thing +is complicated and you have to + + align:start position:0% +is complicated and you have to + + + align:start position:0% +is complicated and you have to +understand several kinds of of forces + + align:start position:0% +understand several kinds of of forces + + + align:start position:0% +understand several kinds of of forces +and so I introduced a few terms the when + + align:start position:0% +and so I introduced a few terms the when + + + align:start position:0% +and so I introduced a few terms the when +we think about protein structure the + + align:start position:0% +we think about protein structure the + + + align:start position:0% +we think about protein structure the +primary structure that's just the linear + + align:start position:0% + + + + align:start position:0% + +sequence + + align:start position:0% + + + + align:start position:0% + +of amino acids so veiling followed by a + + align:start position:0% +of amino acids so veiling followed by a + + + align:start position:0% +of amino acids so veiling followed by a +tryptophane followed by a ProLine + + align:start position:0% +tryptophane followed by a ProLine + + + align:start position:0% +tryptophane followed by a ProLine +followed by a thine whatever it would be + + align:start position:0% +followed by a thine whatever it would be + + + align:start position:0% +followed by a thine whatever it would be +that doesn't tell you very much then the + + align:start position:0% +that doesn't tell you very much then the + + + align:start position:0% +that doesn't tell you very much then the +first key part of understanding how + + align:start position:0% +first key part of understanding how + + + align:start position:0% +first key part of understanding how +proteins get to a three-dimensional + + align:start position:0% +proteins get to a three-dimensional + + + align:start position:0% +proteins get to a three-dimensional +structure was the discovery of what's + + align:start position:0% +structure was the discovery of what's + + + align:start position:0% +structure was the discovery of what's +termed secondary + + align:start position:0% + + + + align:start position:0% + +structure and these are the things I + + align:start position:0% +structure and these are the things I + + + align:start position:0% +structure and these are the things I +introduced to the other day there's two + + align:start position:0% +introduced to the other day there's two + + + align:start position:0% +introduced to the other day there's two +important ones an Al Alpha + + align:start position:0% + + + + align:start position:0% + +Helix and a beta sheet and this is a + + align:start position:0% +Helix and a beta sheet and this is a + + + align:start position:0% +Helix and a beta sheet and this is a +propensity of a certain string of amino + + align:start position:0% +propensity of a certain string of amino + + + align:start position:0% +propensity of a certain string of amino +acids in this linear sequence to adopt + + align:start position:0% +acids in this linear sequence to adopt + + + align:start position:0% +acids in this linear sequence to adopt +one of + + align:start position:0% +one of + + + align:start position:0% +one of +two uh very common protein structures + + align:start position:0% +two uh very common protein structures + + + align:start position:0% +two uh very common protein structures +and then the important thing about these + + align:start position:0% +and then the important thing about these + + + align:start position:0% +and then the important thing about these +uh elements the the Alpha helices and + + align:start position:0% +uh elements the the Alpha helices and + + + align:start position:0% +uh elements the the Alpha helices and +the beta sheets is they are not not + + align:start position:0% +the beta sheets is they are not not + + + align:start position:0% +the beta sheets is they are not not +dependent on the side chain so they're + + align:start position:0% + + + + align:start position:0% + +not they're instead dependent on + + align:start position:0% +not they're instead dependent on + + + align:start position:0% +not they're instead dependent on +hydrogen + + align:start position:0% + + + + align:start position:0% + +bonds + + align:start position:0% + + + + align:start position:0% + +um between + + align:start position:0% + + + + align:start position:0% + +NH and and the uh carbon double bond + + align:start position:0% +NH and and the uh carbon double bond + + + align:start position:0% +NH and and the uh carbon double bond +oxygen in the + + align:start position:0% + + + + align:start position:0% + +backbone and that was how um lonus + + align:start position:0% +backbone and that was how um lonus + + + align:start position:0% +backbone and that was how um lonus +Pauling figured out originally the alpha + + align:start position:0% +Pauling figured out originally the alpha + + + align:start position:0% +Pauling figured out originally the alpha +Helix he decided to ignore all the side + + align:start position:0% +Helix he decided to ignore all the side + + + align:start position:0% +Helix he decided to ignore all the side +chains and he worked out that you could + + align:start position:0% +chains and he worked out that you could + + + align:start position:0% +chains and he worked out that you could +arrange the backbone of a protein the + + align:start position:0% +arrange the backbone of a protein the + + + align:start position:0% +arrange the backbone of a protein the +peptide bonds into these repeating + + align:start position:0% +peptide bonds into these repeating + + + align:start position:0% +peptide bonds into these repeating +structures that would account for the + + align:start position:0% +structures that would account for the + + + align:start position:0% +structures that would account for the +reflections he'd seen when we get to + + align:start position:0% +reflections he'd seen when we get to + + + align:start position:0% +reflections he'd seen when we get to +talking about how Watson and Crick + + align:start position:0% +talking about how Watson and Crick + + + align:start position:0% +talking about how Watson and Crick +worked out the structure that's how they + + align:start position:0% +worked out the structure that's how they + + + align:start position:0% +worked out the structure that's how they +started out too they decided to ignore + + align:start position:0% +started out too they decided to ignore + + + align:start position:0% +started out too they decided to ignore +if you will the side chain which are the + + align:start position:0% +if you will the side chain which are the + + + align:start position:0% +if you will the side chain which are the +A and G's and C's and T's which turned + + align:start position:0% +A and G's and C's and T's which turned + + + align:start position:0% +A and G's and C's and T's which turned +out to be not a productive way to go + + align:start position:0% +out to be not a productive way to go + + + align:start position:0% +out to be not a productive way to go +after the structure of DNA but in any + + align:start position:0% +after the structure of DNA but in any + + + align:start position:0% +after the structure of DNA but in any +case that was part of + + align:start position:0% +case that was part of + + + align:start position:0% +case that was part of +what lonus Pauling did in working these + + align:start position:0% +what lonus Pauling did in working these + + + align:start position:0% +what lonus Pauling did in working these +out and so those little movies I I + + align:start position:0% +out and so those little movies I I + + + align:start position:0% +out and so those little movies I I +showed you this is an alpha Helix now + + align:start position:0% +showed you this is an alpha Helix now + + + align:start position:0% +showed you this is an alpha Helix now +what has what's been done in this + + align:start position:0% +what has what's been done in this + + + align:start position:0% +what has what's been done in this +picture is all the side chains have been + + align:start position:0% +picture is all the side chains have been + + + align:start position:0% +picture is all the side chains have been +taken off and so you can look at look at + + align:start position:0% +taken off and so you can look at look at + + + align:start position:0% +taken off and so you can look at look at +this in your textbook you'll you you'll + + align:start position:0% +this in your textbook you'll you you'll + + + align:start position:0% +this in your textbook you'll you you'll +see pictures but these hydrogen bonds + + align:start position:0% +see pictures but these hydrogen bonds + + + align:start position:0% +see pictures but these hydrogen bonds +are the the the amino acid is just in + + align:start position:0% +are the the the amino acid is just in + + + align:start position:0% +are the the the amino acid is just in +this Helix it's coiling around and at + + align:start position:0% +this Helix it's coiling around and at + + + align:start position:0% +this Helix it's coiling around and at +regular intervals there's the + + align:start position:0% +regular intervals there's the + + + align:start position:0% +regular intervals there's the +opportunity for forming a hydrogen bond + + align:start position:0% +opportunity for forming a hydrogen bond + + + align:start position:0% +opportunity for forming a hydrogen bond +and we can with some success but + + align:start position:0% +and we can with some success but + + + align:start position:0% +and we can with some success but +certainly not certainty predict that a + + align:start position:0% +certainly not certainty predict that a + + + align:start position:0% +certainly not certainty predict that a +particular sequence of amino acids is + + align:start position:0% +particular sequence of amino acids is + + + align:start position:0% +particular sequence of amino acids is +going to uh form an alpha Helix and part + + align:start position:0% +going to uh form an alpha Helix and part + + + align:start position:0% +going to uh form an alpha Helix and part +of what that's based on is there's some + + align:start position:0% +of what that's based on is there's some + + + align:start position:0% +of what that's based on is there's some +amino acids that don't fit easily into + + align:start position:0% +amino acids that don't fit easily into + + + align:start position:0% +amino acids that don't fit easily into +an alpha Helix so they'll disrupt one if + + align:start position:0% +an alpha Helix so they'll disrupt one if + + + align:start position:0% +an alpha Helix so they'll disrupt one if +it would ever tried to form so that's + + align:start position:0% +it would ever tried to form so that's + + + align:start position:0% +it would ever tried to form so that's +one of the elements of protein + + align:start position:0% +one of the elements of protein + + + align:start position:0% +one of the elements of protein +structures so what you might get from + + align:start position:0% +structures so what you might get from + + + align:start position:0% +structures so what you might get from +this is the idea that somewhere along + + align:start position:0% +this is the idea that somewhere along + + + align:start position:0% +this is the idea that somewhere along +here this little piece of the linear + + align:start position:0% +here this little piece of the linear + + + align:start position:0% +here this little piece of the linear +sequence is apt to be an alah Helix and + + align:start position:0% +sequence is apt to be an alah Helix and + + + align:start position:0% +sequence is apt to be an alah Helix and +you can represent that as this little + + align:start position:0% +you can represent that as this little + + + align:start position:0% +you can represent that as this little +sort of coil that you've seen in these + + align:start position:0% +sort of coil that you've seen in these + + + align:start position:0% +sort of coil that you've seen in these +three-dimensional structures the other + + align:start position:0% +three-dimensional structures the other + + + align:start position:0% +three-dimensional structures the other +one which is the beta sheet now that + + align:start position:0% +one which is the beta sheet now that + + + align:start position:0% +one which is the beta sheet now that +involves interactions between + + align:start position:0% +involves interactions between + + + align:start position:0% +involves interactions between +two pieces of uh two stretches of amino + + align:start position:0% +two pieces of uh two stretches of amino + + + align:start position:0% +two pieces of uh two stretches of amino +acids maybe there was a loop in + + align:start position:0% +acids maybe there was a loop in + + + align:start position:0% +acids maybe there was a loop in +between and then you can get + + align:start position:0% +between and then you can get + + + align:start position:0% +between and then you can get +interactions between them and that oh so + + align:start position:0% +interactions between them and that oh so + + + align:start position:0% +interactions between them and that oh so +let me just + + align:start position:0% +let me just + + + align:start position:0% +let me just +go there's the uh there's the the beta + + align:start position:0% +go there's the uh there's the the beta + + + align:start position:0% +go there's the uh there's the the beta +sheet interaction now those are + + align:start position:0% +sheet interaction now those are + + + align:start position:0% +sheet interaction now those are +represented as arrows you now it takes + + align:start position:0% +represented as arrows you now it takes + + + align:start position:0% +represented as arrows you now it takes +two of them to go so you got to have to + + align:start position:0% +two of them to go so you got to have to + + + align:start position:0% +two of them to go so you got to have to +to represent a beta sheet in a + + align:start position:0% +to represent a beta sheet in a + + + align:start position:0% +to represent a beta sheet in a +three-dimensional structure you have + + align:start position:0% +three-dimensional structure you have + + + align:start position:0% +three-dimensional structure you have +have to have two of those broad arrows + + align:start position:0% +have to have two of those broad arrows + + + align:start position:0% +have to have two of those broad arrows +and there was a question why were there + + align:start position:0% +and there was a question why were there + + + align:start position:0% +and there was a question why were there +arrows on them well one of the things I + + align:start position:0% +arrows on them well one of the things I + + + align:start position:0% +arrows on them well one of the things I +think you can see if you look at those + + align:start position:0% +think you can see if you look at those + + + align:start position:0% +think you can see if you look at those +backbones is that both nucleic acid and + + align:start position:0% +backbones is that both nucleic acid and + + + align:start position:0% +backbones is that both nucleic acid and +protein backbones there's a polarity if + + align:start position:0% +protein backbones there's a polarity if + + + align:start position:0% +protein backbones there's a polarity if +you start this direction say the the + + align:start position:0% +you start this direction say the the + + + align:start position:0% +you start this direction say the the +amino Terminus it's got a tri a + + align:start position:0% +amino Terminus it's got a tri a + + + align:start position:0% +amino Terminus it's got a tri a +particular direction it's not symmetric + + align:start position:0% +particular direction it's not symmetric + + + align:start position:0% +particular direction it's not symmetric +if you come back the other way you find + + align:start position:0% +if you come back the other way you find + + + align:start position:0% +if you come back the other way you find +carboxy Amino the alpha carbon and + + align:start position:0% +carboxy Amino the alpha carbon and + + + align:start position:0% +carboxy Amino the alpha carbon and +you'll find it in the opposite order if + + align:start position:0% +you'll find it in the opposite order if + + + align:start position:0% +you'll find it in the opposite order if +you come back the other way so there's + + align:start position:0% +you come back the other way so there's + + + align:start position:0% +you come back the other way so there's +an inherent polarity the arrows aren't + + align:start position:0% +an inherent polarity the arrows aren't + + + align:start position:0% +an inherent polarity the arrows aren't +represented on here but they are + + align:start position:0% +represented on here but they are + + + align:start position:0% +represented on here but they are +um they are um when you look at it in + + align:start position:0% +um they are um when you look at it in + + + align:start position:0% +um they are um when you look at it in +three three dimensions and you can + + align:start position:0% +three three dimensions and you can + + + align:start position:0% +three three dimensions and you can +either form beta sheets where the two + + align:start position:0% +either form beta sheets where the two + + + align:start position:0% +either form beta sheets where the two +strands have the same polarity or if in + + align:start position:0% +strands have the same polarity or if in + + + align:start position:0% +strands have the same polarity or if in +a case like that where they loop back + + align:start position:0% +a case like that where they loop back + + + align:start position:0% +a case like that where they loop back +then of course if if this one was + + align:start position:0% +then of course if if this one was + + + align:start position:0% +then of course if if this one was +pointing in this direction as it goes + + align:start position:0% +pointing in this direction as it goes + + + align:start position:0% +pointing in this direction as it goes +through the loop then the opposite + + align:start position:0% +through the loop then the opposite + + + align:start position:0% +through the loop then the opposite +strand will will be of the um pointing + + align:start position:0% +strand will will be of the um pointing + + + align:start position:0% +strand will will be of the um pointing +in the other polarity one going this way + + align:start position:0% +in the other polarity one going this way + + + align:start position:0% +in the other polarity one going this way +and one going that way um so + + align:start position:0% +and one going that way um so + + + align:start position:0% +and one going that way um so +the the this part is is sort of helpful + + align:start position:0% +the the this part is is sort of helpful + + + align:start position:0% +the the this part is is sort of helpful +you can make guesses that maybe this + + align:start position:0% +you can make guesses that maybe this + + + align:start position:0% +you can make guesses that maybe this +part has a tendency over here to form a + + align:start position:0% +part has a tendency over here to form a + + + align:start position:0% +part has a tendency over here to form a +beta + + align:start position:0% +beta + + + align:start position:0% +beta +sheet but you still haven't gotten very + + align:start position:0% +sheet but you still haven't gotten very + + + align:start position:0% +sheet but you still haven't gotten very +far towards understanding how you get to + + align:start position:0% +far towards understanding how you get to + + + align:start position:0% +far towards understanding how you get to +the threedimensional structure and I + + align:start position:0% +the threedimensional structure and I + + + align:start position:0% +the threedimensional structure and I +just by putting on um and superimposing + + align:start position:0% +just by putting on um and superimposing + + + align:start position:0% +just by putting on um and superimposing +some amino acids onto that um a sec here + + align:start position:0% +some amino acids onto that um a sec here + + + align:start position:0% +some amino acids onto that um a sec here +let's just get that onto that Alpha + + align:start position:0% +let's just get that onto that Alpha + + + align:start position:0% +let's just get that onto that Alpha +Helix then you can see what happens that + + align:start position:0% +Helix then you can see what happens that + + + align:start position:0% +Helix then you can see what happens that +if you form an alpha Helix what happen + + align:start position:0% +if you form an alpha Helix what happen + + + align:start position:0% +if you form an alpha Helix what happen +happens is all the side chains stick out + + align:start position:0% +happens is all the side chains stick out + + + align:start position:0% +happens is all the side chains stick out +and now I think you can see those of you + + align:start position:0% +and now I think you can see those of you + + + align:start position:0% +and now I think you can see those of you +Engineers anyway if you wanted to build + + align:start position:0% +Engineers anyway if you wanted to build + + + align:start position:0% +Engineers anyway if you wanted to build +something you have a cylinder and you + + align:start position:0% +something you have a cylinder and you + + + align:start position:0% +something you have a cylinder and you +can stick amino acids out that have + + align:start position:0% +can stick amino acids out that have + + + align:start position:0% +can stick amino acids out that have +particular chemical characteristics and + + align:start position:0% +particular chemical characteristics and + + + align:start position:0% +particular chemical characteristics and +depending on the characteristics of + + align:start position:0% +depending on the characteristics of + + + align:start position:0% +depending on the characteristics of +those amino acids whether they have + + align:start position:0% +those amino acids whether they have + + + align:start position:0% +those amino acids whether they have +charges on them or they hate water or + + align:start position:0% +charges on them or they hate water or + + + align:start position:0% +charges on them or they hate water or +something that will influence what + + align:start position:0% +something that will influence what + + + align:start position:0% +something that will influence what +happens to that component of the of the + + align:start position:0% +happens to that component of the of the + + + align:start position:0% +happens to that component of the of the +protein structure when it gets into a + + align:start position:0% +protein structure when it gets into a + + + align:start position:0% +protein structure when it gets into a +three-dimensional uh threedimensional + + align:start position:0% +three-dimensional uh threedimensional + + + align:start position:0% +three-dimensional uh threedimensional +thing and as I think I I showed you the + + align:start position:0% +thing and as I think I I showed you the + + + align:start position:0% +thing and as I think I I showed you the +other day when we caught it on looking + + align:start position:0% +other day when we caught it on looking + + + align:start position:0% +other day when we caught it on looking +down the end on this particular example + + align:start position:0% +down the end on this particular example + + + align:start position:0% +down the end on this particular example +here are a couple of aromatic amino + + align:start position:0% +here are a couple of aromatic amino + + + align:start position:0% +here are a couple of aromatic amino +acids right here they're on the same + + align:start position:0% +acids right here they're on the same + + + align:start position:0% +acids right here they're on the same +side of the Helix and they would hate + + align:start position:0% +side of the Helix and they would hate + + + align:start position:0% +side of the Helix and they would hate +water whereas some of the other amino + + align:start position:0% +water whereas some of the other amino + + + align:start position:0% +water whereas some of the other amino +acids up here are ones that have charges + + align:start position:0% +acids up here are ones that have charges + + + align:start position:0% +acids up here are ones that have charges +so those would love water so what this + + align:start position:0% +so those would love water so what this + + + align:start position:0% +so those would love water so what this +would look like is a cylinder part of + + align:start position:0% +would look like is a cylinder part of + + + align:start position:0% +would look like is a cylinder part of +which heat heated water and part of + + align:start position:0% +which heat heated water and part of + + + align:start position:0% +which heat heated water and part of +which loved water and you might guess as + + align:start position:0% +which loved water and you might guess as + + + align:start position:0% +which loved water and you might guess as +if it folded up in three-dimensional + + align:start position:0% +if it folded up in three-dimensional + + + align:start position:0% +if it folded up in three-dimensional +space the part that hat hated water + + align:start position:0% +space the part that hat hated water + + + align:start position:0% +space the part that hat hated water +might fold towards the inside of the + + align:start position:0% +might fold towards the inside of the + + + align:start position:0% +might fold towards the inside of the +protein and the part of the cylinder the + + align:start position:0% +protein and the part of the cylinder the + + + align:start position:0% +protein and the part of the cylinder the +loved water would face to the outside so + + align:start position:0% +loved water would face to the outside so + + + align:start position:0% +loved water would face to the outside so +that's sort of the underlying principle + + align:start position:0% +that's sort of the underlying principle + + + align:start position:0% +that's sort of the underlying principle +but so the rest of the the other forces + + align:start position:0% +but so the rest of the the other forces + + + align:start position:0% +but so the rest of the the other forces +that we had to + + align:start position:0% +that we had to + + + align:start position:0% +that we had to +understand in order to get to the terti + + align:start position:0% +understand in order to get to the terti + + + align:start position:0% +understand in order to get to the terti +What's called the tertiary + + align:start position:0% + + + + align:start position:0% + +structure this is the + + align:start position:0% +structure this is the + + + align:start position:0% +structure this is the +full + + align:start position:0% +full + + + align:start position:0% +full +3d structure which we can now determine + + align:start position:0% +3d structure which we can now determine + + + align:start position:0% +3d structure which we can now determine +by a variety of of methods x-ray + + align:start position:0% +by a variety of of methods x-ray + + + align:start position:0% +by a variety of of methods x-ray +crystallography of proteins is is the + + align:start position:0% +crystallography of proteins is is the + + + align:start position:0% +crystallography of proteins is is the +probably the most common but NMR for + + align:start position:0% +probably the most common but NMR for + + + align:start position:0% +probably the most common but NMR for +example can be used to derive a + + align:start position:0% +example can be used to derive a + + + align:start position:0% +example can be used to derive a +three-dimensional structure as well and + + align:start position:0% +three-dimensional structure as well and + + + align:start position:0% +three-dimensional structure as well and +the other forces then that go into this + + align:start position:0% +the other forces then that go into this + + + align:start position:0% +the other forces then that go into this +are ionic forces uh someone seemed + + align:start position:0% +are ionic forces uh someone seemed + + + align:start position:0% +are ionic forces uh someone seemed +confused by this but if you have a plus + + align:start position:0% +confused by this but if you have a plus + + + align:start position:0% +confused by this but if you have a plus +charge on this part of an amino acid and + + align:start position:0% +charge on this part of an amino acid and + + + align:start position:0% +charge on this part of an amino acid and +a minus charge here if in + + align:start position:0% +a minus charge here if in + + + align:start position:0% +a minus charge here if in +three-dimensional space the plus charge + + align:start position:0% +three-dimensional space the plus charge + + + align:start position:0% +three-dimensional space the plus charge +got somewhere near the the minus charge + + align:start position:0% +got somewhere near the the minus charge + + + align:start position:0% +got somewhere near the the minus charge +then that would form an ionic bond and I + + align:start position:0% +then that would form an ionic bond and I + + + align:start position:0% +then that would form an ionic bond and I +think most of you know enough + + align:start position:0% +think most of you know enough + + + align:start position:0% +think most of you know enough +electricity and magnetism that wouldn't + + align:start position:0% +electricity and magnetism that wouldn't + + + align:start position:0% +electricity and magnetism that wouldn't +surprise you that that those would those + + align:start position:0% +surprise you that that those would those + + + align:start position:0% +surprise you that that those would those +two would be attracted the one that I + + align:start position:0% +two would be attracted the one that I + + + align:start position:0% +two would be attracted the one that I +think is has been harder to understand + + align:start position:0% +think is has been harder to understand + + + align:start position:0% +think is has been harder to understand +um is the Vander + + align:start position:0% +um is the Vander + + + align:start position:0% +um is the Vander +bals interactions that we talked about + + align:start position:0% +bals interactions that we talked about + + + align:start position:0% +bals interactions that we talked about +which is the other day which is is + + align:start position:0% +which is the other day which is is + + + align:start position:0% +which is the other day which is is +tricky in the sense that it's I I don't + + align:start position:0% +tricky in the sense that it's I I don't + + + align:start position:0% +tricky in the sense that it's I I don't +for this course you don't particularly + + align:start position:0% +for this course you don't particularly + + + align:start position:0% +for this course you don't particularly +really need to understand understand the + + align:start position:0% +really need to understand understand the + + + align:start position:0% +really need to understand understand the +underlying chemistry but the principle + + align:start position:0% +underlying chemistry but the principle + + + align:start position:0% +underlying chemistry but the principle +of it is that if you have a non-polar + + align:start position:0% +of it is that if you have a non-polar + + + align:start position:0% +of it is that if you have a non-polar +Bond one that isn't got any particular + + align:start position:0% +Bond one that isn't got any particular + + + align:start position:0% +Bond one that isn't got any particular +attraction to it gets very very close to + + align:start position:0% +attraction to it gets very very close to + + + align:start position:0% +attraction to it gets very very close to +another one then the FL the transient + + align:start position:0% +another one then the FL the transient + + + align:start position:0% +another one then the FL the transient +fluctuations in one indu something in + + align:start position:0% +fluctuations in one indu something in + + + align:start position:0% +fluctuations in one indu something in +the other one that makes them stick + + align:start position:0% +the other one that makes them stick + + + align:start position:0% +the other one that makes them stick +together and the whole point about this + + align:start position:0% +together and the whole point about this + + + align:start position:0% +together and the whole point about this +is if you get two molecular surfaces + + align:start position:0% +is if you get two molecular surfaces + + + align:start position:0% +is if you get two molecular surfaces +that are very very close together about + + align:start position:0% +that are very very close together about + + + align:start position:0% +that are very very close together about +you know maybe two times the length of a + + align:start position:0% +you know maybe two times the length of a + + + align:start position:0% +you know maybe two times the length of a +of a calent bond or something then you + + align:start position:0% +of a calent bond or something then you + + + align:start position:0% +of a calent bond or something then you +can generate uh very powerful forces + + align:start position:0% +can generate uh very powerful forces + + + align:start position:0% +can generate uh very powerful forces +because even though the very each + + align:start position:0% +because even though the very each + + + align:start position:0% +because even though the very each +individual interaction is weak about a + + align:start position:0% +individual interaction is weak about a + + + align:start position:0% +individual interaction is weak about a +quarter or a third of a hydrogen bond + + align:start position:0% +quarter or a third of a hydrogen bond + + + align:start position:0% +quarter or a third of a hydrogen bond +summing them up can make them very very + + align:start position:0% +summing them up can make them very very + + + align:start position:0% +summing them up can make them very very +strong and so that's another kind of + + align:start position:0% +strong and so that's another kind of + + + align:start position:0% +strong and so that's another kind of +force that's important when a linear + + align:start position:0% +force that's important when a linear + + + align:start position:0% +force that's important when a linear +molecule is trying to figure out how in + + align:start position:0% +molecule is trying to figure out how in + + + align:start position:0% +molecule is trying to figure out how in +space it's going to fold up the point of + + align:start position:0% +space it's going to fold up the point of + + + align:start position:0% +space it's going to fold up the point of +the gecko thing was it's only recently + + align:start position:0% +the gecko thing was it's only recently + + + align:start position:0% +the gecko thing was it's only recently +relative recently been discovered that + + align:start position:0% +relative recently been discovered that + + + align:start position:0% +relative recently been discovered that +the reason those lizards can stick to + + align:start position:0% +the reason those lizards can stick to + + + align:start position:0% +the reason those lizards can stick to +walls is they have sort of incredible + + align:start position:0% +walls is they have sort of incredible + + + align:start position:0% +walls is they have sort of incredible +split + + align:start position:0% +split + + + align:start position:0% +split +ends noticed a couple of you came to the + + align:start position:0% +ends noticed a couple of you came to the + + + align:start position:0% +ends noticed a couple of you came to the +uh to Bob F's talk the other day and you + + align:start position:0% +uh to Bob F's talk the other day and you + + + align:start position:0% +uh to Bob F's talk the other day and you +got to hear the full treatment but + + align:start position:0% +got to hear the full treatment but + + + align:start position:0% +got to hear the full treatment but +because their hairs on their on their + + align:start position:0% +because their hairs on their on their + + + align:start position:0% +because their hairs on their on their +feet are so split they're very fine and + + align:start position:0% +feet are so split they're very fine and + + + align:start position:0% +feet are so split they're very fine and +these these uh the molecules are able to + + align:start position:0% +these these uh the molecules are able to + + + align:start position:0% +these these uh the molecules are able to +make very close interaction vender + + align:start position:0% +make very close interaction vender + + + align:start position:0% +make very close interaction vender +Fall's interactions with the surface and + + align:start position:0% +Fall's interactions with the surface and + + + align:start position:0% +Fall's interactions with the surface and +that's what's holding the gecko to the + + align:start position:0% +that's what's holding the gecko to the + + + align:start position:0% +that's what's holding the gecko to the +wall and there's just so many of of them + + align:start position:0% +wall and there's just so many of of them + + + align:start position:0% +wall and there's just so many of of them +that it can support a whole Gecko and + + align:start position:0% +that it can support a whole Gecko and + + + align:start position:0% +that it can support a whole Gecko and +that's what could be the basis he say + + align:start position:0% +that's what could be the basis he say + + + align:start position:0% +that's what could be the basis he say +said to me of a somewhere 30 to 50 + + align:start position:0% +said to me of a somewhere 30 to 50 + + + align:start position:0% +said to me of a somewhere 30 to 50 +billion adhesive industry a + + align:start position:0% +billion adhesive industry a + + + align:start position:0% +billion adhesive industry a +self-cleaning dry adhesive and it's it's + + align:start position:0% +self-cleaning dry adhesive and it's it's + + + align:start position:0% +self-cleaning dry adhesive and it's it's +not something magic only the gecko hair + + align:start position:0% +not something magic only the gecko hair + + + align:start position:0% +not something magic only the gecko hair +will do you can design synthetic + + align:start position:0% +will do you can design synthetic + + + align:start position:0% +will do you can design synthetic +molecules that have the same property + + align:start position:0% +molecules that have the same property + + + align:start position:0% +molecules that have the same property +you're able to make these millions of + + align:start position:0% +you're able to make these millions of + + + align:start position:0% +you're able to make these millions of +Vander Falls interactions so that's two + + align:start position:0% +Vander Falls interactions so that's two + + + align:start position:0% +Vander Falls interactions so that's two +of the other things and the final thing + + align:start position:0% +of the other things and the final thing + + + align:start position:0% +of the other things and the final thing +was which isn't really a force but goes + + align:start position:0% +was which isn't really a force but goes + + + align:start position:0% +was which isn't really a force but goes +into this is this + + align:start position:0% +into this is this + + + align:start position:0% +into this is this +hydrophobic effect and that is that if + + align:start position:0% +hydrophobic effect and that is that if + + + align:start position:0% +hydrophobic effect and that is that if +we have things amino acids such as veine + + align:start position:0% +we have things amino acids such as veine + + + align:start position:0% +we have things amino acids such as veine +or something that doesn't like to mix + + align:start position:0% +or something that doesn't like to mix + + + align:start position:0% +or something that doesn't like to mix +with + + align:start position:0% +with + + + align:start position:0% +with +water then when the protein folds up the + + align:start position:0% +water then when the protein folds up the + + + align:start position:0% +water then when the protein folds up the +things that don't like to interact with + + align:start position:0% +things that don't like to interact with + + + align:start position:0% +things that don't like to interact with +water will kind of go together just the + + align:start position:0% +water will kind of go together just the + + + align:start position:0% +water will kind of go together just the +way if you put a lot of oil in the water + + align:start position:0% +way if you put a lot of oil in the water + + + align:start position:0% +way if you put a lot of oil in the water +it'll sort of pull together because + + align:start position:0% +it'll sort of pull together because + + + align:start position:0% +it'll sort of pull together because +anytime you have something that gets + + align:start position:0% +anytime you have something that gets + + + align:start position:0% +anytime you have something that gets +stuck in water it disrupts hydrogen + + align:start position:0% +stuck in water it disrupts hydrogen + + + align:start position:0% +stuck in water it disrupts hydrogen +bonds and and that's energetically + + align:start position:0% +bonds and and that's energetically + + + align:start position:0% +bonds and and that's energetically +unfavorable so the things that hate + + align:start position:0% +unfavorable so the things that hate + + + align:start position:0% +unfavorable so the things that hate +water will tend to Lump Lump together + + align:start position:0% +water will tend to Lump Lump together + + + align:start position:0% +water will tend to Lump Lump together +and you're all used to seeing little + + align:start position:0% +and you're all used to seeing little + + + align:start position:0% +and you're all used to seeing little +drops of of oil and stuff floating + + align:start position:0% +drops of of oil and stuff floating + + + align:start position:0% +drops of of oil and stuff floating +around and so um let me just switch over + + align:start position:0% +around and so um let me just switch over + + + align:start position:0% +around and so um let me just switch over +to this other thing + + align:start position:0% + + + + align:start position:0% + +now so this was just showing you one of + + align:start position:0% +now so this was just showing you one of + + + align:start position:0% +now so this was just showing you one of +these protein chains that's folded up + + align:start position:0% +these protein chains that's folded up + + + align:start position:0% +these protein chains that's folded up +into a three-dimensional structure this + + align:start position:0% +into a three-dimensional structure this + + + align:start position:0% +into a three-dimensional structure this +happens to be uh something with with an + + align:start position:0% +happens to be uh something with with an + + + align:start position:0% +happens to be uh something with with an +enzymatic activity but the important + + align:start position:0% +enzymatic activity but the important + + + align:start position:0% +enzymatic activity but the important +thing for right now is what's been + + align:start position:0% +thing for right now is what's been + + + align:start position:0% +thing for right now is what's been +colored in here are the amino acids that + + align:start position:0% +colored in here are the amino acids that + + + align:start position:0% +colored in here are the amino acids that +if you looked back on the the list of + + align:start position:0% +if you looked back on the the list of + + + align:start position:0% +if you looked back on the the list of +amino acids and what categories are + + align:start position:0% +amino acids and what categories are + + + align:start position:0% +amino acids and what categories are +you'd see some of them are called said + + align:start position:0% +you'd see some of them are called said + + + align:start position:0% +you'd see some of them are called said +to have hydrophobic side chains and this + + align:start position:0% +to have hydrophobic side chains and this + + + align:start position:0% +to have hydrophobic side chains and this +is quite you can see quite strikingly + + align:start position:0% +is quite you can see quite strikingly + + + align:start position:0% +is quite you can see quite strikingly +how the amino acids in the interior part + + align:start position:0% +how the amino acids in the interior part + + + align:start position:0% +how the amino acids in the interior part +of this protein have clustered together + + align:start position:0% +of this protein have clustered together + + + align:start position:0% +of this protein have clustered together +they don't like to interact with water + + align:start position:0% +they don't like to interact with water + + + align:start position:0% +they don't like to interact with water +they interact very well with each other + + align:start position:0% +they interact very well with each other + + + align:start position:0% +they interact very well with each other +just like you can mix butter and oil + + align:start position:0% +just like you can mix butter and oil + + + align:start position:0% +just like you can mix butter and oil +they mix together together very well and + + align:start position:0% +they mix together together very well and + + + align:start position:0% +they mix together together very well and +so that is another factor that + + align:start position:0% +so that is another factor that + + + align:start position:0% +so that is another factor that +contributes to the three-dimensional + + align:start position:0% +contributes to the three-dimensional + + + align:start position:0% +contributes to the three-dimensional +structure of these uh of these proteins + + align:start position:0% +structure of these uh of these proteins + + + align:start position:0% +structure of these uh of these proteins +so understanding what proteins are all + + align:start position:0% +so understanding what proteins are all + + + align:start position:0% +so understanding what proteins are all +about means ultimately understanding + + align:start position:0% +about means ultimately understanding + + + align:start position:0% +about means ultimately understanding +their three-dimensional structure and as + + align:start position:0% +their three-dimensional structure and as + + + align:start position:0% +their three-dimensional structure and as +I say a big unsolved problem right at + + align:start position:0% +I say a big unsolved problem right at + + + align:start position:0% +I say a big unsolved problem right at +the moment is how do you get from a + + align:start position:0% +the moment is how do you get from a + + + align:start position:0% +the moment is how do you get from a +linear chain of amino acids to one of + + align:start position:0% +linear chain of amino acids to one of + + + align:start position:0% +linear chain of amino acids to one of +these uh three-dimensional structures + + align:start position:0% +these uh three-dimensional structures + + + align:start position:0% +these uh three-dimensional structures +and you can imagine with 20 different + + align:start position:0% +and you can imagine with 20 different + + + align:start position:0% +and you can imagine with 20 different +side chains there's + + align:start position:0% +side chains there's + + + align:start position:0% +side chains there's +unbelievable number of combinations that + + align:start position:0% +unbelievable number of combinations that + + + align:start position:0% +unbelievable number of combinations that +you can make yet almost every protein + + align:start position:0% +you can make yet almost every protein + + + align:start position:0% +you can make yet almost every protein +has that's in nature has one unique or + + align:start position:0% +has that's in nature has one unique or + + + align:start position:0% +has that's in nature has one unique or +one or two or something you uh + + align:start position:0% +one or two or something you uh + + + align:start position:0% +one or two or something you uh +confirmations that takes out out of all + + align:start position:0% +confirmations that takes out out of all + + + align:start position:0% +confirmations that takes out out of all +the kinds of things that you could do + + align:start position:0% +the kinds of things that you could do + + + align:start position:0% +the kinds of things that you could do +and it's this combination of forces that + + align:start position:0% +and it's this combination of forces that + + + align:start position:0% +and it's this combination of forces that +does that does that now the final let me + + align:start position:0% +does that does that now the final let me + + + align:start position:0% +does that does that now the final let me +just go back for one sec so the final + + align:start position:0% +just go back for one sec so the final + + + align:start position:0% +just go back for one sec so the final +thing that one talks about when you're + + align:start position:0% +thing that one talks about when you're + + + align:start position:0% +thing that one talks about when you're +talking about proteins are quaternary + + align:start position:0% +talking about proteins are quaternary + + + align:start position:0% +talking about proteins are quaternary +structure + + align:start position:0% + + + + align:start position:0% + +and what that means is when you have + + align:start position:0% +and what that means is when you have + + + align:start position:0% +and what that means is when you have +more than + + align:start position:0% +more than + + + align:start position:0% +more than +one um poly + + align:start position:0% + + + + align:start position:0% + +peptide chain so if we have two + + align:start position:0% +peptide chain so if we have two + + + align:start position:0% +peptide chain so if we have two +different uh proteins that interact this + + align:start position:0% +different uh proteins that interact this + + + align:start position:0% +different uh proteins that interact this +is protein number one and this is + + align:start position:0% +is protein number one and this is + + + align:start position:0% +is protein number one and this is +protein number two then there has to be + + align:start position:0% +protein number two then there has to be + + + align:start position:0% +protein number two then there has to be +some sort of interaction between each of + + align:start position:0% +some sort of interaction between each of + + + align:start position:0% +some sort of interaction between each of +these three-dimensional structures in + + align:start position:0% +these three-dimensional structures in + + + align:start position:0% +these three-dimensional structures in +order for the proteins to stick together + + align:start position:0% +order for the proteins to stick together + + + align:start position:0% +order for the proteins to stick together +and something like that felar motor that + + align:start position:0% +and something like that felar motor that + + + align:start position:0% +and something like that felar motor that +makes let the bacteria swim has many + + align:start position:0% +makes let the bacteria swim has many + + + align:start position:0% +makes let the bacteria swim has many +many parts all of which have to fit + + align:start position:0% +many parts all of which have to fit + + + align:start position:0% +many parts all of which have to fit +together just the same way all the + + align:start position:0% +together just the same way all the + + + align:start position:0% +together just the same way all the +different parts of an engine have to fit + + align:start position:0% +different parts of an engine have to fit + + + align:start position:0% +different parts of an engine have to fit +together now this next one this next + + align:start position:0% +together now this next one this next + + + align:start position:0% +together now this next one this next +little movie is just a a dier it's + + align:start position:0% +little movie is just a a dier it's + + + align:start position:0% +little movie is just a a dier it's +actually a heterodimer so it's made of + + align:start position:0% +actually a heterodimer so it's made of + + + align:start position:0% +actually a heterodimer so it's made of +two proteins they're different but + + align:start position:0% +two proteins they're different but + + + align:start position:0% +two proteins they're different but +they're come they've come together and + + align:start position:0% +they're come they've come together and + + + align:start position:0% +they're come they've come together and +they're um they're interacting so what + + align:start position:0% +they're um they're interacting so what + + + align:start position:0% +they're um they're interacting so what +you will first see is the + + align:start position:0% +you will first see is the + + + align:start position:0% +you will first see is the +three-dimensional structure of the uh of + + align:start position:0% +three-dimensional structure of the uh of + + + align:start position:0% +three-dimensional structure of the uh of +each protein um showing the alpha heles + + align:start position:0% +each protein um showing the alpha heles + + + align:start position:0% +each protein um showing the alpha heles +the beta sheets and nothing else is + + align:start position:0% +the beta sheets and nothing else is + + + align:start position:0% +the beta sheets and nothing else is +shown the side chains aren't shown the + + align:start position:0% +shown the side chains aren't shown the + + + align:start position:0% +shown the side chains aren't shown the +other the molecular surfaces aren't + + align:start position:0% +other the molecular surfaces aren't + + + align:start position:0% +other the molecular surfaces aren't +shown you can just see the backbone + + align:start position:0% +shown you can just see the backbone + + + align:start position:0% +shown you can just see the backbone +you'll see Alpha Helix a turn some beta + + align:start position:0% +you'll see Alpha Helix a turn some beta + + + align:start position:0% +you'll see Alpha Helix a turn some beta +sheets just the kind of stuff you were + + align:start position:0% +sheets just the kind of stuff you were + + + align:start position:0% +sheets just the kind of stuff you were +seeing the other day but you'll see that + + align:start position:0% +seeing the other day but you'll see that + + + align:start position:0% +seeing the other day but you'll see that +the two proteins are together and this + + align:start position:0% +the two proteins are together and this + + + align:start position:0% +the two proteins are together and this +is actually a movie made by Tom Schwarz + + align:start position:0% +is actually a movie made by Tom Schwarz + + + align:start position:0% +is actually a movie made by Tom Schwarz +who's a crystallographer who just + + align:start position:0% +who's a crystallographer who just + + + align:start position:0% +who's a crystallographer who just +started you on our faculty this this + + align:start position:0% +started you on our faculty this this + + + align:start position:0% +started you on our faculty this this +fall in the biology department is one of + + align:start position:0% +fall in the biology department is one of + + + align:start position:0% +fall in the biology department is one of +the proteins he studied and then after + + align:start position:0% +the proteins he studied and then after + + + align:start position:0% +the proteins he studied and then after +that and he rotates it around so you can + + align:start position:0% +that and he rotates it around so you can + + + align:start position:0% +that and he rotates it around so you can +see it after that he then puts on the + + align:start position:0% +see it after that he then puts on the + + + align:start position:0% +see it after that he then puts on the +side chains and then traces the surface + + align:start position:0% +side chains and then traces the surface + + + align:start position:0% +side chains and then traces the surface +so this is what they call the Vander + + align:start position:0% +so this is what they call the Vander + + + align:start position:0% +so this is what they call the Vander +valal surface so this is what the + + align:start position:0% +valal surface so this is what the + + + align:start position:0% +valal surface so this is what the +protein would actually look like and + + align:start position:0% +protein would actually look like and + + + align:start position:0% +protein would actually look like and +what I'd like you to what I think you'll + + align:start position:0% +what I'd like you to what I think you'll + + + align:start position:0% +what I'd like you to what I think you'll +see from this is how incredibly well the + + align:start position:0% +see from this is how incredibly well the + + + align:start position:0% +see from this is how incredibly well the +proteins fit together I mean they by the + + align:start position:0% +proteins fit together I mean they by the + + + align:start position:0% +proteins fit together I mean they by the +theme of sort of probably keep saying + + align:start position:0% +theme of sort of probably keep saying + + + align:start position:0% +theme of sort of probably keep saying +all the way through the course is + + align:start position:0% +all the way through the course is + + + align:start position:0% +all the way through the course is +biology works from fitting shapes and + + align:start position:0% +biology works from fitting shapes and + + + align:start position:0% +biology works from fitting shapes and +things have to work incredibly well and + + align:start position:0% +things have to work incredibly well and + + + align:start position:0% +things have to work incredibly well and +that's also why these Vander valal + + align:start position:0% +that's also why these Vander valal + + + align:start position:0% +that's also why these Vander valal +forces become so important because + + align:start position:0% +forces become so important because + + + align:start position:0% +forces become so important because +Evolution has ended up making things + + align:start position:0% +Evolution has ended up making things + + + align:start position:0% +Evolution has ended up making things +that just go together just like a hand + + align:start position:0% +that just go together just like a hand + + + align:start position:0% +that just go together just like a hand +and a perfectly fit glove that's the way + + align:start position:0% +and a perfectly fit glove that's the way + + + align:start position:0% +and a perfectly fit glove that's the way +most of these interactions are so watch + + align:start position:0% +most of these interactions are so watch + + + align:start position:0% +most of these interactions are so watch +this little movie so you see the light + + align:start position:0% +this little movie so you see the light + + + align:start position:0% +this little movie so you see the light +blue is one of the proteins there's an + + align:start position:0% +blue is one of the proteins there's an + + + align:start position:0% +blue is one of the proteins there's an +alpha Helix there's a lot of alpha + + align:start position:0% +alpha Helix there's a lot of alpha + + + align:start position:0% +alpha Helix there's a lot of alpha +helices in this one the purple one's the + + align:start position:0% +helices in this one the purple one's the + + + align:start position:0% +helices in this one the purple one's the +other protein and you can see that in + + align:start position:0% +other protein and you can see that in + + + align:start position:0% +other protein and you can see that in +between them there's a there's an + + align:start position:0% +between them there's a there's an + + + align:start position:0% +between them there's a there's an +interface and so those must be + + align:start position:0% +interface and so those must be + + + align:start position:0% +interface and so those must be +interacting but when when he + + align:start position:0% +interacting but when when he + + + align:start position:0% +interacting but when when he +superimposes now + + align:start position:0% +superimposes now + + + align:start position:0% +superimposes now +the all the amino acids in the surface + + align:start position:0% +the all the amino acids in the surface + + + align:start position:0% +the all the amino acids in the surface +now what he's going to do he's going to + + align:start position:0% +now what he's going to do he's going to + + + align:start position:0% +now what he's going to do he's going to +pull those apart so you can see where + + align:start position:0% +pull those apart so you can see where + + + align:start position:0% +pull those apart so you can see where +they were + + align:start position:0% + + + + align:start position:0% + +interacting you get the idea now of how + + align:start position:0% +interacting you get the idea now of how + + + align:start position:0% +interacting you get the idea now of how +beautifully these things have folded up + + align:start position:0% +beautifully these things have folded up + + + align:start position:0% +beautifully these things have folded up +in three-dimensional space and position + + align:start position:0% +in three-dimensional space and position + + + align:start position:0% +in three-dimensional space and position +so that they can fit together and work + + align:start position:0% +so that they can fit together and work + + + align:start position:0% +so that they can fit together and work +together as a machine just the same way + + align:start position:0% +together as a machine just the same way + + + align:start position:0% +together as a machine just the same way +if you were building a machine and you + + align:start position:0% +if you were building a machine and you + + + align:start position:0% +if you were building a machine and you +needed to have two parts that haded you + + align:start position:0% +needed to have two parts that haded you + + + align:start position:0% +needed to have two parts that haded you +had to Jo joing together you've got to + + align:start position:0% +had to Jo joing together you've got to + + + align:start position:0% +had to Jo joing together you've got to +Tool things so that the surfaces go + + align:start position:0% +Tool things so that the surfaces go + + + align:start position:0% +Tool things so that the surfaces go +exactly together that's what uh um + + align:start position:0% +exactly together that's what uh um + + + align:start position:0% +exactly together that's what uh um +nature does that's also why this why I'm + + align:start position:0% +nature does that's also why this why I'm + + + align:start position:0% +nature does that's also why this why I'm +making such a deal out of this + + align:start position:0% +making such a deal out of this + + + align:start position:0% +making such a deal out of this +three-dimensional structure of of + + align:start position:0% +three-dimensional structure of of + + + align:start position:0% +three-dimensional structure of of +proteins and how it got there I could + + align:start position:0% +proteins and how it got there I could + + + align:start position:0% +proteins and how it got there I could +just say it gets there by Magic but it + + align:start position:0% +just say it gets there by Magic but it + + + align:start position:0% +just say it gets there by Magic but it +doesn't it's determined by this set of + + align:start position:0% +doesn't it's determined by this set of + + + align:start position:0% +doesn't it's determined by this set of +forces and one of the things we can't do + + align:start position:0% +forces and one of the things we can't do + + + align:start position:0% +forces and one of the things we can't do +at this point is predict here's a linear + + align:start position:0% +at this point is predict here's a linear + + + align:start position:0% +at this point is predict here's a linear +sequence of amino acids here's the 3D + + align:start position:0% +sequence of amino acids here's the 3D + + + align:start position:0% +sequence of amino acids here's the 3D +structure that would be a huge advance + + align:start position:0% +structure that would be a huge advance + + + align:start position:0% +structure that would be a huge advance +in biology if one of you guys could + + align:start position:0% +in biology if one of you guys could + + + align:start position:0% +in biology if one of you guys could +figure figure out how to do that during + + align:start position:0% +figure figure out how to do that during + + + align:start position:0% +figure figure out how to do that during +your + + align:start position:0% +your + + + align:start position:0% +your +career + + align:start position:0% +career + + + align:start position:0% +career +okay um + + align:start position:0% +okay um + + + align:start position:0% +okay um +so just want + + align:start position:0% +so just want + + + align:start position:0% +so just want +to reiterate some of the things that + + align:start position:0% +to reiterate some of the things that + + + align:start position:0% +to reiterate some of the things that +proteins do because we'll be talking + + align:start position:0% +proteins do because we'll be talking + + + align:start position:0% +proteins do because we'll be talking +about them as we go + + align:start position:0% +about them as we go + + + align:start position:0% +about them as we go +along one thing they do they they act as + + align:start position:0% +along one thing they do they they act as + + + align:start position:0% +along one thing they do they they act as +enzymes which are + + align:start position:0% +enzymes which are + + + align:start position:0% +enzymes which are +catalysts for biological reactions that + + align:start position:0% +catalysts for biological reactions that + + + align:start position:0% +catalysts for biological reactions that +take place under physiological + + align:start position:0% +take place under physiological + + + align:start position:0% +take place under physiological +conditions and will give you a lot of of + + align:start position:0% +conditions and will give you a lot of of + + + align:start position:0% +conditions and will give you a lot of of +examples of those enzymes starting uh + + align:start position:0% +examples of those enzymes starting uh + + + align:start position:0% +examples of those enzymes starting uh +very soon um they play structural + + align:start position:0% + + + + align:start position:0% + +roles our hair our fingernails made of + + align:start position:0% +roles our hair our fingernails made of + + + align:start position:0% +roles our hair our fingernails made of +protein are the the hairs on the gecko's + + align:start position:0% +protein are the the hairs on the gecko's + + + align:start position:0% +protein are the the hairs on the gecko's +feet are made of keratin which is the + + align:start position:0% +feet are made of keratin which is the + + + align:start position:0% +feet are made of keratin which is the +same stuff our hair is made of except + + align:start position:0% +same stuff our hair is made of except + + + align:start position:0% +same stuff our hair is made of except +they basically got a whole lot of split + + align:start position:0% +they basically got a whole lot of split + + + align:start position:0% +they basically got a whole lot of split +ends they're finer hairs to begin with + + align:start position:0% +ends they're finer hairs to begin with + + + align:start position:0% +ends they're finer hairs to begin with +and a lot of split ends and that's what + + align:start position:0% +and a lot of split ends and that's what + + + align:start position:0% +and a lot of split ends and that's what +makes these very very fine things that + + align:start position:0% +makes these very very fine things that + + + align:start position:0% +makes these very very fine things that +can make + + align:start position:0% +can make + + + align:start position:0% +can make +vendal interactions with with surfaces + + align:start position:0% +vendal interactions with with surfaces + + + align:start position:0% +vendal interactions with with surfaces +um they play roles + + align:start position:0% +um they play roles + + + align:start position:0% +um they play roles +in specificity for example mentioned the + + align:start position:0% +in specificity for example mentioned the + + + align:start position:0% +in specificity for example mentioned the +antibodies and we'll talk about the + + align:start position:0% +antibodies and we'll talk about the + + + align:start position:0% +antibodies and we'll talk about the +immune response in some detail at the + + align:start position:0% +immune response in some detail at the + + + align:start position:0% +immune response in some detail at the +end of + + align:start position:0% +end of + + + align:start position:0% +end of +the uh end of the uh course and one of + + align:start position:0% +the uh end of the uh course and one of + + + align:start position:0% +the uh end of the uh course and one of +the really magic things that we've come + + align:start position:0% +the really magic things that we've come + + + align:start position:0% +the really magic things that we've come +to understand in biology recently is how + + align:start position:0% +to understand in biology recently is how + + + align:start position:0% +to understand in biology recently is how +it is that your body has uh this immune + + align:start position:0% +it is that your body has uh this immune + + + align:start position:0% +it is that your body has uh this immune +system that's able to recognize + + align:start position:0% +system that's able to recognize + + + align:start position:0% +system that's able to recognize +literally any molecule any molecule + + align:start position:0% +literally any molecule any molecule + + + align:start position:0% +literally any molecule any molecule +doesn't matter whether it's existed or + + align:start position:0% +doesn't matter whether it's existed or + + + align:start position:0% +doesn't matter whether it's existed or +you in your PhD thesis and chemistry + + align:start position:0% +you in your PhD thesis and chemistry + + + align:start position:0% +you in your PhD thesis and chemistry +synthesize something the world has never + + align:start position:0% +synthesize something the world has never + + + align:start position:0% +synthesize something the world has never +seen before your immune system can + + align:start position:0% +seen before your immune system can + + + align:start position:0% +seen before your immune system can +create an antibody or something that + + align:start position:0% +create an antibody or something that + + + align:start position:0% +create an antibody or something that +will very very specifically recognize + + align:start position:0% +will very very specifically recognize + + + align:start position:0% +will very very specifically recognize +that particular shape and just the same + + align:start position:0% +that particular shape and just the same + + + align:start position:0% +that particular shape and just the same +sort of way that you saw the the shape + + align:start position:0% +sort of way that you saw the the shape + + + align:start position:0% +sort of way that you saw the the shape +on that uh on that movie and you might + + align:start position:0% +on that uh on that movie and you might + + + align:start position:0% +on that uh on that movie and you might +think You' need to Cod a zillion pieces + + align:start position:0% +think You' need to Cod a zillion pieces + + + align:start position:0% +think You' need to Cod a zillion pieces +of miles of DNA in order to do that but + + align:start position:0% +of miles of DNA in order to do that but + + + align:start position:0% +of miles of DNA in order to do that but +there's a trick using combination and uh + + align:start position:0% +there's a trick using combination and uh + + + align:start position:0% +there's a trick using combination and uh +combinatorial functions and uh and + + align:start position:0% +combinatorial functions and uh and + + + align:start position:0% +combinatorial functions and uh and +mutation that lets your body your body + + align:start position:0% +mutation that lets your body your body + + + align:start position:0% +mutation that lets your body your body +do that and final another example which + + align:start position:0% +do that and final another example which + + + align:start position:0% +do that and final another example which +I've was showing you + + align:start position:0% +I've was showing you + + + align:start position:0% +I've was showing you +where uh they can do all sorts of little + + align:start position:0% +where uh they can do all sorts of little + + + align:start position:0% +where uh they can do all sorts of little +Motors and machines i' showed you the + + align:start position:0% +Motors and machines i' showed you the + + + align:start position:0% +Motors and machines i' showed you the +bacteria uh swimming around these these + + align:start position:0% +bacteria uh swimming around these these + + + align:start position:0% +bacteria uh swimming around these these +are just eoli and you can't see the + + align:start position:0% +are just eoli and you can't see the + + + align:start position:0% +are just eoli and you can't see the +Feller Motors but you can see them + + align:start position:0% +Feller Motors but you can see them + + + align:start position:0% +Feller Motors but you can see them +buzzing around on uh just under a cover + + align:start position:0% +buzzing around on uh just under a cover + + + align:start position:0% +buzzing around on uh just under a cover +slip some of them are stuck to the cover + + align:start position:0% +slip some of them are stuck to the cover + + + align:start position:0% +slip some of them are stuck to the cover +slip and um well there we go uh in this + + align:start position:0% +slip and um well there we go uh in this + + + align:start position:0% +slip and um well there we go uh in this +one which was taken by Howard Berg who's + + align:start position:0% +one which was taken by Howard Berg who's + + + align:start position:0% +one which was taken by Howard Berg who's +a professor at Harvard this is on his + + align:start position:0% +a professor at Harvard this is on his + + + align:start position:0% +a professor at Harvard this is on his +web just took this off his website you + + align:start position:0% +web just took this off his website you + + + align:start position:0% +web just took this off his website you +can see the the bacteria Swimming by + + align:start position:0% +can see the the bacteria Swimming by + + + align:start position:0% +can see the the bacteria Swimming by +having these flagella which are + + align:start position:0% +having these flagella which are + + + align:start position:0% +having these flagella which are +basically like sort of propellers more + + align:start position:0% +basically like sort of propellers more + + + align:start position:0% +basically like sort of propellers more +or less that they turn um here's one + + align:start position:0% +or less that they turn um here's one + + + align:start position:0% +or less that they turn um here's one +where he used the strobe so you can get + + align:start position:0% +where he used the strobe so you can get + + + align:start position:0% +where he used the strobe so you can get +a little bit better view of it and I + + align:start position:0% +a little bit better view of it and I + + + align:start position:0% +a little bit better view of it and I +showed you this picture of or in the in + + align:start position:0% +showed you this picture of or in the in + + + align:start position:0% +showed you this picture of or in the in +the first lecture so that's a machine + + align:start position:0% +the first lecture so that's a machine + + + align:start position:0% +the first lecture so that's a machine +but every single part of that machine is + + align:start position:0% +but every single part of that machine is + + + align:start position:0% +but every single part of that machine is +is made of a protein that's got a very + + align:start position:0% +is made of a protein that's got a very + + + align:start position:0% +is made of a protein that's got a very +thre diim certain threedimensional space + + align:start position:0% +thre diim certain threedimensional space + + + align:start position:0% +thre diim certain threedimensional space +and we're going to start talking about + + align:start position:0% +and we're going to start talking about + + + align:start position:0% +and we're going to start talking about +energetics uh how does a cell get energy + + align:start position:0% +energetics uh how does a cell get energy + + + align:start position:0% +energetics uh how does a cell get energy +and one of the things you might wonder + + align:start position:0% +and one of the things you might wonder + + + align:start position:0% +and one of the things you might wonder +is if you were to design such a nanom + + align:start position:0% +is if you were to design such a nanom + + + align:start position:0% +is if you were to design such a nanom +machine how would you power + + align:start position:0% +machine how would you power + + + align:start position:0% +machine how would you power +it they exist I mean it's + + align:start position:0% +it they exist I mean it's + + + align:start position:0% +it they exist I mean it's +here uh but that's why in part part I'm + + align:start position:0% +here uh but that's why in part part I'm + + + align:start position:0% +here uh but that's why in part part I'm +going to start telling talking about + + align:start position:0% +going to start telling talking about + + + align:start position:0% +going to start telling talking about +energy and how cells make energy because + + align:start position:0% +energy and how cells make energy because + + + align:start position:0% +energy and how cells make energy because +this is one of the things they have to + + align:start position:0% +this is one of the things they have to + + + align:start position:0% +this is one of the things they have to +do and that was I said was a an averaged + + align:start position:0% +do and that was I said was a an averaged + + + align:start position:0% +do and that was I said was a an averaged +electron micrograph of a lot of those + + align:start position:0% +electron micrograph of a lot of those + + + align:start position:0% +electron micrograph of a lot of those +Motors so you can see that although um + + align:start position:0% +Motors so you can see that although um + + + align:start position:0% +Motors so you can see that although um +you know that's the textbook thing the + + align:start position:0% +you know that's the textbook thing the + + + align:start position:0% +you know that's the textbook thing the +actual thing uh is pretty much the same + + align:start position:0% +actual thing uh is pretty much the same + + + align:start position:0% +actual thing uh is pretty much the same +shape this is not at a resolution where + + align:start position:0% +shape this is not at a resolution where + + + align:start position:0% +shape this is not at a resolution where +you can make out the individual proteins + + align:start position:0% +you can make out the individual proteins + + + align:start position:0% +you can make out the individual proteins +that put it together but those are know + + align:start position:0% +that put it together but those are know + + + align:start position:0% +that put it together but those are know +some of those are starting to be known + + align:start position:0% +some of those are starting to be known + + + align:start position:0% +some of those are starting to be known +in three-dimensional detail and just I + + align:start position:0% +in three-dimensional detail and just I + + + align:start position:0% +in three-dimensional detail and just I +thought you might enjoy seeing this just + + align:start position:0% +thought you might enjoy seeing this just + + + align:start position:0% +thought you might enjoy seeing this just +to convince you at some motor in this + + align:start position:0% +to convince you at some motor in this + + + align:start position:0% +to convince you at some motor in this +thing what Howard Berg did was he stuck + + align:start position:0% +thing what Howard Berg did was he stuck + + + align:start position:0% +thing what Howard Berg did was he stuck +the propeller if you will the flagella + + align:start position:0% +the propeller if you will the flagella + + + align:start position:0% +the propeller if you will the flagella +to a cover slip using using an antibody + + align:start position:0% +to a cover slip using using an antibody + + + align:start position:0% +to a cover slip using using an antibody +and then um he let them do their thing + + align:start position:0% +and then um he let them do their thing + + + align:start position:0% +and then um he let them do their thing +and normally they would be turning the + + align:start position:0% +and normally they would be turning the + + + align:start position:0% +and normally they would be turning the +propeller and in swimming but if the + + align:start position:0% +propeller and in swimming but if the + + + align:start position:0% +propeller and in swimming but if the +propeller is attached the same thing + + align:start position:0% +propeller is attached the same thing + + + align:start position:0% +propeller is attached the same thing +would happen if you held on the + + align:start position:0% +would happen if you held on the + + + align:start position:0% +would happen if you held on the +propeller of a boat and turned on the + + align:start position:0% +propeller of a boat and turned on the + + + align:start position:0% +propeller of a boat and turned on the +motor the boat would start twirling + + align:start position:0% +motor the boat would start twirling + + + align:start position:0% +motor the boat would start twirling +around and what you seeing here is + + align:start position:0% +around and what you seeing here is + + + align:start position:0% +around and what you seeing here is +bacteria they're twirling around because + + align:start position:0% +bacteria they're twirling around because + + + align:start position:0% +bacteria they're twirling around because +they're fella are stuck on and those of + + align:start position:0% +they're fella are stuck on and those of + + + align:start position:0% +they're fella are stuck on and those of +you who are observant will notice even + + align:start position:0% +you who are observant will notice even + + + align:start position:0% +you who are observant will notice even +that they change direction and that's + + align:start position:0% +that they change direction and that's + + + align:start position:0% +that they change direction and that's +part of the way the part of the system + + align:start position:0% +part of the way the part of the system + + + align:start position:0% +part of the way the part of the system +that bacteria use so they can swim + + align:start position:0% +that bacteria use so they can swim + + + align:start position:0% +that bacteria use so they can swim +towards a food source or away from from + + align:start position:0% +towards a food source or away from from + + + align:start position:0% +towards a food source or away from from +uh another one okay here's just + + align:start position:0% +uh another one okay here's just + + + align:start position:0% +uh another one okay here's just +something to let you uh guys think about + + align:start position:0% +something to let you uh guys think about + + + align:start position:0% +something to let you uh guys think about +it if anybody can figure this one out + + align:start position:0% +it if anybody can figure this one out + + + align:start position:0% +it if anybody can figure this one out +send me an email here's something else + + align:start position:0% +send me an email here's something else + + + align:start position:0% +send me an email here's something else +the phenomenon I'm going to show you is + + align:start position:0% +the phenomenon I'm going to show you is + + + align:start position:0% +the phenomenon I'm going to show you is +due to a protein made by a soil + + align:start position:0% +due to a protein made by a soil + + + align:start position:0% +due to a protein made by a soil +bacterium it's called Pamona singi you + + align:start position:0% +bacterium it's called Pamona singi you + + + align:start position:0% +bacterium it's called Pamona singi you +don't need to know that it Associates + + align:start position:0% +don't need to know that it Associates + + + align:start position:0% +don't need to know that it Associates +with plants and uh what you're going to + + align:start position:0% +with plants and uh what you're going to + + + align:start position:0% +with plants and uh what you're going to +see is a little movie made by a couple + + align:start position:0% +see is a little movie made by a couple + + + align:start position:0% +see is a little movie made by a couple +of the posts in my lab where we they + + align:start position:0% +of the posts in my lab where we they + + + align:start position:0% +of the posts in my lab where we they +took pure water and if it's pure water + + align:start position:0% +took pure water and if it's pure water + + + align:start position:0% +took pure water and if it's pure water +you can cool it below freezing you can + + align:start position:0% +you can cool it below freezing you can + + + align:start position:0% +you can cool it below freezing you can +get it down to I don't know- 8° + + align:start position:0% +get it down to I don't know- 8° + + + align:start position:0% +get it down to I don't know- 8° +centigrade and it still will be a liquid + + align:start position:0% +centigrade and it still will be a liquid + + + align:start position:0% +centigrade and it still will be a liquid +even though you know water freezes at uh + + align:start position:0% +even though you know water freezes at uh + + + align:start position:0% +even though you know water freezes at uh +at 0° centigrade and what it has to do + + align:start position:0% +at 0° centigrade and what it has to do + + + align:start position:0% +at 0° centigrade and what it has to do +in in order to turn into ice somewhere + + align:start position:0% +in in order to turn into ice somewhere + + + align:start position:0% +in in order to turn into ice somewhere +you have to nucleate the formation of an + + align:start position:0% +you have to nucleate the formation of an + + + align:start position:0% +you have to nucleate the formation of an +Ice Crystal once it goes uh going so + + align:start position:0% +Ice Crystal once it goes uh going so + + + align:start position:0% +Ice Crystal once it goes uh going so +anyway what you're going to see is some + + align:start position:0% +anyway what you're going to see is some + + + align:start position:0% +anyway what you're going to see is some +super cooled water they've made you can + + align:start position:0% +super cooled water they've made you can + + + align:start position:0% +super cooled water they've made you can +see there's uh 0 degrees there and this + + align:start position:0% +see there's uh 0 degrees there and this + + + align:start position:0% +see there's uh 0 degrees there and this +is Mei taga one of the post dogs in my + + align:start position:0% +is Mei taga one of the post dogs in my + + + align:start position:0% +is Mei taga one of the post dogs in my +lab that's the super cooled water she's + + align:start position:0% +lab that's the super cooled water she's + + + align:start position:0% +lab that's the super cooled water she's +taking a little bit of culture of this + + align:start position:0% +taking a little bit of culture of this + + + align:start position:0% +taking a little bit of culture of this +uh Pamona singi and she's just going to + + align:start position:0% +uh Pamona singi and she's just going to + + + align:start position:0% +uh Pamona singi and she's just going to +put it in give a little tiny squirt of a + + align:start position:0% +put it in give a little tiny squirt of a + + + align:start position:0% +put it in give a little tiny squirt of a +few microliters into that uh + + align:start position:0% +few microliters into that uh + + + align:start position:0% +few microliters into that uh +water now it's going all cloudy you know + + align:start position:0% +water now it's going all cloudy you know + + + align:start position:0% +water now it's going all cloudy you know +you might wonder what's uh what's + + align:start position:0% +you might wonder what's uh what's + + + align:start position:0% +you might wonder what's uh what's +happening there but as you'll discover + + align:start position:0% +happening there but as you'll discover + + + align:start position:0% +happening there but as you'll discover +what happened is that what was liquid + + align:start position:0% +what happened is that what was liquid + + + align:start position:0% +what happened is that what was liquid +water is now + + align:start position:0% + + + + align:start position:0% + +ice now that is due to one + + align:start position:0% +ice now that is due to one + + + align:start position:0% +ice now that is due to one +protein that this bacteria makes and + + align:start position:0% +protein that this bacteria makes and + + + align:start position:0% +protein that this bacteria makes and +displays on its surface here's a control + + align:start position:0% +displays on its surface here's a control + + + align:start position:0% +displays on its surface here's a control +experiment this is putting in a little + + align:start position:0% +experiment this is putting in a little + + + align:start position:0% +experiment this is putting in a little +bit of um Raz oium melotti another soil + + align:start position:0% +bit of um Raz oium melotti another soil + + + align:start position:0% +bit of um Raz oium melotti another soil +organism and same amount of bacteria + + align:start position:0% +organism and same amount of bacteria + + + align:start position:0% +organism and same amount of bacteria +didn't happen Okay so that's due to a + + align:start position:0% +didn't happen Okay so that's due to a + + + align:start position:0% +didn't happen Okay so that's due to a +protein uh that was on + + align:start position:0% +protein uh that was on + + + align:start position:0% +protein uh that was on +um uh on the surface of that bacterium + + align:start position:0% +um uh on the surface of that bacterium + + + align:start position:0% +um uh on the surface of that bacterium +anybody have any idea what that could do + + align:start position:0% +anybody have any idea what that could do + + + align:start position:0% +anybody have any idea what that could do +send me an + + align:start position:0% +send me an + + + align:start position:0% +send me an +email + + align:start position:0% +email + + + align:start position:0% +email +okay there's one last class of a bial + + align:start position:0% +okay there's one last class of a bial + + + align:start position:0% +okay there's one last class of a bial +Macro + + align:start position:0% +Macro + + + align:start position:0% +Macro +Molecule + + align:start position:0% + + + + align:start position:0% + +those are + + align:start position:0% +those are + + + align:start position:0% +those are +lipids these + + align:start position:0% +lipids these + + + align:start position:0% +lipids these +are a little they're a little different + + align:start position:0% +are a little they're a little different + + + align:start position:0% +are a little they're a little different +in the sense that this is not now a long + + align:start position:0% +in the sense that this is not now a long + + + align:start position:0% +in the sense that this is not now a long +chain made by joining together subunits + + align:start position:0% +chain made by joining together subunits + + + align:start position:0% +chain made by joining together subunits +as we've seen with the proteins and + + align:start position:0% +as we've seen with the proteins and + + + align:start position:0% +as we've seen with the proteins and +nucleic acids but putting together the + + align:start position:0% +nucleic acids but putting together the + + + align:start position:0% +nucleic acids but putting together the +parts necessary to make uh a lipid + + align:start position:0% +parts necessary to make uh a lipid + + + align:start position:0% +parts necessary to make uh a lipid +involve the same principle that you end + + align:start position:0% +involve the same principle that you end + + + align:start position:0% +involve the same principle that you end +up splitting out water molecules that's + + align:start position:0% +up splitting out water molecules that's + + + align:start position:0% +up splitting out water molecules that's +a theme you've heard over and over again + + align:start position:0% +a theme you've heard over and over again + + + align:start position:0% +a theme you've heard over and over again +and if we take three lung chain three + + align:start position:0% +and if we take three lung chain three + + + align:start position:0% +and if we take three lung chain three +Three fatty acids + + align:start position:0% +Three fatty acids + + + align:start position:0% +Three fatty acids +uh some number + + align:start position:0% + + + + align:start position:0% + +of some number of + + align:start position:0% + + + + align:start position:0% + +carbons just some arbitrary + + align:start position:0% +carbons just some arbitrary + + + align:start position:0% +carbons just some arbitrary +number + + align:start position:0% +number + + + align:start position:0% +number +here and then we take a + + align:start position:0% +here and then we take a + + + align:start position:0% +here and then we take a +three + + align:start position:0% + + + + align:start position:0% + +carbon compound that has three hydroxy + + align:start position:0% + + + + align:start position:0% + +groups now this is not a carbohydrate + + align:start position:0% +groups now this is not a carbohydrate + + + align:start position:0% +groups now this is not a carbohydrate +because you'll notice there's not a + + align:start position:0% +because you'll notice there's not a + + + align:start position:0% +because you'll notice there's not a +double uh there's not a double bond + + align:start position:0% +double uh there's not a double bond + + + align:start position:0% +double uh there's not a double bond +oxygen um as we uh as you saw in the + + align:start position:0% +oxygen um as we uh as you saw in the + + + align:start position:0% +oxygen um as we uh as you saw in the +carbohydrates It's actually an alcohol + + align:start position:0% +carbohydrates It's actually an alcohol + + + align:start position:0% +carbohydrates It's actually an alcohol +it's known as glycerol + + align:start position:0% + + + + align:start position:0% + +and if we split out + + align:start position:0% + + + + align:start position:0% + +water like + + align:start position:0% + + + + align:start position:0% + +this what you get is a + + align:start position:0% +this what you get is a + + + align:start position:0% +this what you get is a +fat something you're you're familiar + + align:start position:0% +fat something you're you're familiar + + + align:start position:0% +fat something you're you're familiar +with from B fat or if you get something + + align:start position:0% +with from B fat or if you get something + + + align:start position:0% +with from B fat or if you get something +like olive oil you've heard the term + + align:start position:0% +like olive oil you've heard the term + + + align:start position:0% +like olive oil you've heard the term +unsaturated fats + + align:start position:0% +unsaturated fats + + + align:start position:0% +unsaturated fats +um maybe you recall from the second + + align:start position:0% +um maybe you recall from the second + + + align:start position:0% +um maybe you recall from the second +lecture that if we had a single calent + + align:start position:0% +lecture that if we had a single calent + + + align:start position:0% +lecture that if we had a single calent +Bond uh or if we had a double or a + + align:start position:0% +Bond uh or if we had a double or a + + + align:start position:0% +Bond uh or if we had a double or a +triple bond that was called an + + align:start position:0% +triple bond that was called an + + + align:start position:0% +triple bond that was called an +unsaturated uh fatty uh unsaturated Bond + + align:start position:0% +unsaturated uh fatty uh unsaturated Bond + + + align:start position:0% +unsaturated uh fatty uh unsaturated Bond +so if you have an + + align:start position:0% +so if you have an + + + align:start position:0% +so if you have an +unsaturated bond in here somewhere then + + align:start position:0% +unsaturated bond in here somewhere then + + + align:start position:0% +unsaturated bond in here somewhere then +you end up with an unsaturated fat and + + align:start position:0% +you end up with an unsaturated fat and + + + align:start position:0% +you end up with an unsaturated fat and +most of you know probably something like + + align:start position:0% +most of you know probably something like + + + align:start position:0% +most of you know probably something like +beef fat is solid if you put it in the + + align:start position:0% +beef fat is solid if you put it in the + + + align:start position:0% +beef fat is solid if you put it in the +refrigerator and something like peanut + + align:start position:0% +refrigerator and something like peanut + + + align:start position:0% +refrigerator and something like peanut +oil will stay liquid and that's because + + align:start position:0% +oil will stay liquid and that's because + + + align:start position:0% +oil will stay liquid and that's because +if you you have just + + align:start position:0% +if you you have just + + + align:start position:0% +if you you have just +saturated uh side chains on from this + + align:start position:0% +saturated uh side chains on from this + + + align:start position:0% +saturated uh side chains on from this +then they pack together very very + + align:start position:0% +then they pack together very very + + + align:start position:0% +then they pack together very very +tightly and they they will form a solid + + align:start position:0% +tightly and they they will form a solid + + + align:start position:0% +tightly and they they will form a solid +if you put a double bond in then there's + + align:start position:0% +if you put a double bond in then there's + + + align:start position:0% +if you put a double bond in then there's +a kink in the backbone and it's hard for + + align:start position:0% +a kink in the backbone and it's hard for + + + align:start position:0% +a kink in the backbone and it's hard for +these things to uh pack packed together + + align:start position:0% +these things to uh pack packed together + + + align:start position:0% +these things to uh pack packed together +and that's why they're called um called + + align:start position:0% +and that's why they're called um called + + + align:start position:0% +and that's why they're called um called +unsaturated uh unsaturated fats now + + align:start position:0% +unsaturated uh unsaturated fats now + + + align:start position:0% +unsaturated uh unsaturated fats now +there's a very particular kind of of + + align:start position:0% +there's a very particular kind of of + + + align:start position:0% +there's a very particular kind of of +lipid that's of unbelievable importance + + align:start position:0% +lipid that's of unbelievable importance + + + align:start position:0% +lipid that's of unbelievable importance +in bi ology and that's known as a + + align:start position:0% + + + + align:start position:0% + +phospho lipid and the reason that's so + + align:start position:0% +phospho lipid and the reason that's so + + + align:start position:0% +phospho lipid and the reason that's so +important is that that is the boundary + + align:start position:0% +important is that that is the boundary + + + align:start position:0% +important is that that is the boundary +that determines the outside of a of a + + align:start position:0% +that determines the outside of a of a + + + align:start position:0% +that determines the outside of a of a +cell so every cell every organism either + + align:start position:0% +cell so every cell every organism either + + + align:start position:0% +cell so every cell every organism either +is a single cell or is made up of + + align:start position:0% +is a single cell or is made up of + + + align:start position:0% +is a single cell or is made up of +multiple cells and I said it the in the + + align:start position:0% +multiple cells and I said it the in the + + + align:start position:0% +multiple cells and I said it the in the +first lecture that the one of the + + align:start position:0% +first lecture that the one of the + + + align:start position:0% +first lecture that the one of the +secrets to life is having a boundary + + align:start position:0% +secrets to life is having a boundary + + + align:start position:0% +secrets to life is having a boundary +that goes around your insides that + + align:start position:0% +that goes around your insides that + + + align:start position:0% +that goes around your insides that +separates your sides from all the rest + + align:start position:0% +separates your sides from all the rest + + + align:start position:0% +separates your sides from all the rest +of the of the universe and the way the + + align:start position:0% +of the of the universe and the way the + + + align:start position:0% +of the of the universe and the way the +these uh + + align:start position:0% +these uh + + + align:start position:0% +these uh +membranes is they're called are made + + align:start position:0% +membranes is they're called are made + + + align:start position:0% +membranes is they're called are made +of it's what's known as a + + align:start position:0% + + + + align:start position:0% + +phospho lipid by layer and it's the same + + align:start position:0% +phospho lipid by layer and it's the same + + + align:start position:0% +phospho lipid by layer and it's the same +Principle as before it uses a a + + align:start position:0% +Principle as before it uses a a + + + align:start position:0% +Principle as before it uses a a +glycerol except that one of + + align:start position:0% +glycerol except that one of + + + align:start position:0% +glycerol except that one of +the + + align:start position:0% + + + + align:start position:0% + +one of the fatty acids is replaced by a + + align:start position:0% +one of the fatty acids is replaced by a + + + align:start position:0% +one of the fatty acids is replaced by a +phosphate group that will have some kind + + align:start position:0% +phosphate group that will have some kind + + + align:start position:0% +phosphate group that will have some kind +of decoration uh added onto it and the + + align:start position:0% +of decoration uh added onto it and the + + + align:start position:0% +of decoration uh added onto it and the +other will + + align:start position:0% + + + + align:start position:0% + +have fatty acids at the other two + + align:start position:0% + + + + align:start position:0% + +positions + + align:start position:0% +positions + + + align:start position:0% +positions +now you'll notice by splitting out water + + align:start position:0% +now you'll notice by splitting out water + + + align:start position:0% +now you'll notice by splitting out water +here what we the kind of bond we have + + align:start position:0% +here what we the kind of bond we have + + + align:start position:0% +here what we the kind of bond we have +created the chemical name of this is an + + align:start position:0% +created the chemical name of this is an + + + align:start position:0% +created the chemical name of this is an +ester + + align:start position:0% +ester + + + align:start position:0% +ester +Bond if we wanted to add it uh break it + + align:start position:0% +Bond if we wanted to add it uh break it + + + align:start position:0% +Bond if we wanted to add it uh break it +we could add uh Add Water back across it + + align:start position:0% +we could add uh Add Water back across it + + + align:start position:0% +we could add uh Add Water back across it +um so what's important about the this + + align:start position:0% +um so what's important about the this + + + align:start position:0% +um so what's important about the this +molecule is this part of the + + align:start position:0% +molecule is this part of the + + + align:start position:0% +molecule is this part of the +molecule if you will + + align:start position:0% +molecule if you will + + + align:start position:0% +molecule if you will +is water loving because there the uh + + align:start position:0% +is water loving because there the uh + + + align:start position:0% +is water loving because there the uh +very polar bonds here the the oxygen had + + align:start position:0% +very polar bonds here the the oxygen had + + + align:start position:0% +very polar bonds here the the oxygen had +here would have a negative charge on it + + align:start position:0% +here would have a negative charge on it + + + align:start position:0% +here would have a negative charge on it +it under physiological + + align:start position:0% +it under physiological + + + align:start position:0% +it under physiological +conditions and this part is if you will + + align:start position:0% +conditions and this part is if you will + + + align:start position:0% +conditions and this part is if you will +is water + + align:start position:0% +is water + + + align:start position:0% +is water +hating so this is phospholipids are off + + align:start position:0% +hating so this is phospholipids are off + + + align:start position:0% +hating so this is phospholipids are off +opposite often represented in the + + align:start position:0% +opposite often represented in the + + + align:start position:0% +opposite often represented in the +following way where this is the water + + align:start position:0% + + + + align:start position:0% + +loving + + align:start position:0% +loving + + + align:start position:0% +loving +and then this would be the water hating + + align:start position:0% +and then this would be the water hating + + + align:start position:0% +and then this would be the water hating +part here and so if you take + + align:start position:0% +part here and so if you take + + + align:start position:0% +part here and so if you take +phospholipids and you just try and + + align:start position:0% +phospholipids and you just try and + + + align:start position:0% +phospholipids and you just try and +disperse them in water they + + align:start position:0% +disperse them in water they + + + align:start position:0% +disperse them in water they +spontaneously self assemble into + + align:start position:0% +spontaneously self assemble into + + + align:start position:0% +spontaneously self assemble into +structures that bring the + + align:start position:0% +structures that bring the + + + align:start position:0% +structures that bring the +water loving + + align:start position:0% +water loving + + + align:start position:0% +water loving +Parts together + + align:start position:0% +Parts together + + + align:start position:0% +Parts together +and the water hating Parts together and + + align:start position:0% +and the water hating Parts together and + + + align:start position:0% +and the water hating Parts together and +by so doing + + align:start position:0% + + + + align:start position:0% + +this they form what's known as a + + align:start position:0% + + + + align:start position:0% + +phospholipid by layer and that's what + + align:start position:0% +phospholipid by layer and that's what + + + align:start position:0% +phospholipid by layer and that's what +this membrane is made of membrane of a + + align:start position:0% +this membrane is made of membrane of a + + + align:start position:0% +this membrane is made of membrane of a +bacterial cell the membrane of our cells + + align:start position:0% +bacterial cell the membrane of our cells + + + align:start position:0% +bacterial cell the membrane of our cells +virtually the the same same thing it has + + align:start position:0% +virtually the the same same thing it has + + + align:start position:0% +virtually the the same same thing it has +the property that is not permeable to + + align:start position:0% +the property that is not permeable to + + + align:start position:0% +the property that is not permeable to +very much water can get across it a very + + align:start position:0% +very much water can get across it a very + + + align:start position:0% +very much water can get across it a very +limited number of of other chemical + + align:start position:0% +limited number of of other chemical + + + align:start position:0% +limited number of of other chemical +compounds but most things can't and so + + align:start position:0% +compounds but most things can't and so + + + align:start position:0% +compounds but most things can't and so +so what the cell by having this membrane + + align:start position:0% +so what the cell by having this membrane + + + align:start position:0% +so what the cell by having this membrane +what the what the cell is able to do + + align:start position:0% +what the what the cell is able to do + + + align:start position:0% +what the what the cell is able to do +then is control who comes in and who + + align:start position:0% +then is control who comes in and who + + + align:start position:0% +then is control who comes in and who +comes out and the way it does that is it + + align:start position:0% +comes out and the way it does that is it + + + align:start position:0% +comes out and the way it does that is it +has to put particular importers or + + align:start position:0% +has to put particular importers or + + + align:start position:0% +has to put particular importers or +exporters embedded in the membrane that + + align:start position:0% +exporters embedded in the membrane that + + + align:start position:0% +exporters embedded in the membrane that +can carry out those functions because as + + align:start position:0% +can carry out those functions because as + + + align:start position:0% +can carry out those functions because as +you would guess any system would have to + + align:start position:0% +you would guess any system would have to + + + align:start position:0% +you would guess any system would have to +bring stuff in get rid of waste you have + + align:start position:0% +bring stuff in get rid of waste you have + + + align:start position:0% +bring stuff in get rid of waste you have +to be able to go back and forth the + + align:start position:0% +to be able to go back and forth the + + + align:start position:0% +to be able to go back and forth the +things that do all those transports + + align:start position:0% +things that do all those transports + + + align:start position:0% +things that do all those transports +across the membrane what kind of + + align:start position:0% +across the membrane what kind of + + + align:start position:0% +across the membrane what kind of +molecule do you think it would likely to + + align:start position:0% +molecule do you think it would likely to + + + align:start position:0% +molecule do you think it would likely to +be if you were going to Nature was going + + align:start position:0% +be if you were going to Nature was going + + + align:start position:0% +be if you were going to Nature was going +to design something that was a pump to + + align:start position:0% +to design something that was a pump to + + + align:start position:0% +to design something that was a pump to +get something in or something that would + + align:start position:0% +get something in or something that would + + + align:start position:0% +get something in or something that would +get something out any + + align:start position:0% +get something out any + + + align:start position:0% +get something out any +idea what kind of + + align:start position:0% +idea what kind of + + + align:start position:0% +idea what kind of +molecule take a gas I've said so + + align:start position:0% + + + + align:start position:0% + +far protein yeah absolutely and um let + + align:start position:0% +far protein yeah absolutely and um let + + + align:start position:0% +far protein yeah absolutely and um let +me just sort of show you a couple little + + align:start position:0% +me just sort of show you a couple little + + + align:start position:0% +me just sort of show you a couple little +pictures here so here's a representation + + align:start position:0% +pictures here so here's a representation + + + align:start position:0% +pictures here so here's a representation +of this phospholipid Bayer this is + + align:start position:0% +of this phospholipid Bayer this is + + + align:start position:0% +of this phospholipid Bayer this is +pretty standard stuff this is what you'd + + align:start position:0% +pretty standard stuff this is what you'd + + + align:start position:0% +pretty standard stuff this is what you'd +put on a Blackboard here's in Gray now + + align:start position:0% +put on a Blackboard here's in Gray now + + + align:start position:0% +put on a Blackboard here's in Gray now +the phospholipid and here's one of these + + align:start position:0% +the phospholipid and here's one of these + + + align:start position:0% +the phospholipid and here's one of these +proteins a picture one of these proteins + + align:start position:0% +proteins a picture one of these proteins + + + align:start position:0% +proteins a picture one of these proteins +that that functions to get things across + + align:start position:0% +that that functions to get things across + + + align:start position:0% +that that functions to get things across +the membrane and hopefully what you can + + align:start position:0% +the membrane and hopefully what you can + + + align:start position:0% +the membrane and hopefully what you can +see now is that it's made up of a whole + + align:start position:0% +see now is that it's made up of a whole + + + align:start position:0% +see now is that it's made up of a whole +lot of Alpha helices and they pack + + align:start position:0% +lot of Alpha helices and they pack + + + align:start position:0% +lot of Alpha helices and they pack +together to give sort of a cylinder made + + align:start position:0% +together to give sort of a cylinder made + + + align:start position:0% +together to give sort of a cylinder made +up of different Alpha helices that weave + + align:start position:0% +up of different Alpha helices that weave + + + align:start position:0% +up of different Alpha helices that weave +in and out of like this and then you by + + align:start position:0% +in and out of like this and then you by + + + align:start position:0% +in and out of like this and then you by +this sort of trick the protein is able + + align:start position:0% +this sort of trick the protein is able + + + align:start position:0% +this sort of trick the protein is able +to create a channel that runs up and + + align:start position:0% +to create a channel that runs up and + + + align:start position:0% +to create a channel that runs up and +down the middle of the of this Protein + + align:start position:0% +down the middle of the of this Protein + + + align:start position:0% +down the middle of the of this Protein +that's embedded in the membrane and then + + align:start position:0% +that's embedded in the membrane and then + + + align:start position:0% +that's embedded in the membrane and then +depending on the characteristics of that + + align:start position:0% +depending on the characteristics of that + + + align:start position:0% +depending on the characteristics of that +challenge it can of that channel it can + + align:start position:0% +challenge it can of that channel it can + + + align:start position:0% +challenge it can of that channel it can +either be used to bring stuff in or or + + align:start position:0% +either be used to bring stuff in or or + + + align:start position:0% +either be used to bring stuff in or or +or get rid of it now there is a a more + + align:start position:0% +or get rid of it now there is a a more + + + align:start position:0% +or get rid of it now there is a a more +fanciful depiction of it this is not + + align:start position:0% +fanciful depiction of it this is not + + + align:start position:0% +fanciful depiction of it this is not +reality but there you are with the water + + align:start position:0% +reality but there you are with the water + + + align:start position:0% +reality but there you are with the water +loving Parts here the fatty acids going + + align:start position:0% +loving Parts here the fatty acids going + + + align:start position:0% +loving Parts here the fatty acids going +in and this is supposed to be one of + + align:start position:0% +in and this is supposed to be one of + + + align:start position:0% +in and this is supposed to be one of +these membrane proteins now this next + + align:start position:0% +these membrane proteins now this next + + + align:start position:0% +these membrane proteins now this next +movie is + + align:start position:0% +movie is + + + align:start position:0% +movie is +trying to pretend here that it's looking + + align:start position:0% +trying to pretend here that it's looking + + + align:start position:0% +trying to pretend here that it's looking +at one of these membrane proteins + + align:start position:0% +at one of these membrane proteins + + + align:start position:0% +at one of these membrane proteins +colored here in red as it spans the + + align:start position:0% +colored here in red as it spans the + + + align:start position:0% +colored here in red as it spans the +membrane so here's looking from the + + align:start position:0% +membrane so here's looking from the + + + align:start position:0% +membrane so here's looking from the +membrane surface on and now it's going + + align:start position:0% +membrane surface on and now it's going + + + align:start position:0% +membrane surface on and now it's going +to dive into this thing as it crosses + + align:start position:0% +to dive into this thing as it crosses + + + align:start position:0% +to dive into this thing as it crosses +the membrane and it's basically what + + align:start position:0% +the membrane and it's basically what + + + align:start position:0% +the membrane and it's basically what +this movie is letting you do is feel + + align:start position:0% +this movie is letting you do is feel + + + align:start position:0% +this movie is letting you do is feel +like if you were the molecule that's + + align:start position:0% +like if you were the molecule that's + + + align:start position:0% +like if you were the molecule that's +being transported across the membrane + + align:start position:0% +being transported across the membrane + + + align:start position:0% +being transported across the membrane +you see how you'd go right down through + + align:start position:0% +you see how you'd go right down through + + + align:start position:0% +you see how you'd go right down through +uh a channel in the middle of the of the + + align:start position:0% +uh a channel in the middle of the of the + + + align:start position:0% +uh a channel in the middle of the of the +protein so + + align:start position:0% +protein so + + + align:start position:0% +protein so +that's one of the + + align:start position:0% +that's one of the + + + align:start position:0% +that's one of the +underlying principles then is + + align:start position:0% +underlying principles then is + + + align:start position:0% +underlying principles then is +that you have a phospholipid boundary + + align:start position:0% +that you have a phospholipid boundary + + + align:start position:0% +that you have a phospholipid boundary +that's that's critical for life but then + + align:start position:0% +that's that's critical for life but then + + + align:start position:0% +that's that's critical for life but then +to have everything else that needs to + + align:start position:0% +to have everything else that needs to + + + align:start position:0% +to have everything else that needs to +happen the the cell makes a series of + + align:start position:0% +happen the the cell makes a series of + + + align:start position:0% +happen the the cell makes a series of +proteins that function either to bring + + align:start position:0% +proteins that function either to bring + + + align:start position:0% +proteins that function either to bring +stuff in or to bring it out or in the + + align:start position:0% +stuff in or to bring it out or in the + + + align:start position:0% +stuff in or to bring it out or in the +case of something like the Feller motor + + align:start position:0% +case of something like the Feller motor + + + align:start position:0% +case of something like the Feller motor +uh that we talked about it has to embed + + align:start position:0% +uh that we talked about it has to embed + + + align:start position:0% +uh that we talked about it has to embed +part of the Machinery right in the in + + align:start position:0% +part of the Machinery right in the in + + + align:start position:0% +part of the Machinery right in the in +the membrane and one last picture I just + + align:start position:0% +the membrane and one last picture I just + + + align:start position:0% +the membrane and one last picture I just +want to show you usually uh even on that + + align:start position:0% +want to show you usually uh even on that + + + align:start position:0% +want to show you usually uh even on that +movie you tend to see the cell + + align:start position:0% +movie you tend to see the cell + + + align:start position:0% +movie you tend to see the cell +represented something like this with a + + align:start position:0% +represented something like this with a + + + align:start position:0% +represented something like this with a +membrane and every once in a while + + align:start position:0% +membrane and every once in a while + + + align:start position:0% +membrane and every once in a while +there's a protein this is a what it's a + + align:start position:0% +there's a protein this is a what it's a + + + align:start position:0% +there's a protein this is a what it's a +cartoon but it it is a much more much + + align:start position:0% +cartoon but it it is a much more much + + + align:start position:0% +cartoon but it it is a much more much +closer to um scale to scale drawing this + + align:start position:0% +closer to um scale to scale drawing this + + + align:start position:0% +closer to um scale to scale drawing this +is a back an eoli cell now they have an + + align:start position:0% +is a back an eoli cell now they have an + + + align:start position:0% +is a back an eoli cell now they have an +extra membrane that we won't worry about + + align:start position:0% +extra membrane that we won't worry about + + + align:start position:0% +extra membrane that we won't worry about +right for the moment but right there + + align:start position:0% +right for the moment but right there + + + align:start position:0% +right for the moment but right there +there's this little piece we can see + + align:start position:0% +there's this little piece we can see + + + align:start position:0% +there's this little piece we can see +little bits of is the the cell's + + align:start position:0% +little bits of is the the cell's + + + align:start position:0% +little bits of is the the cell's +membrane and what this picture is + + align:start position:0% +membrane and what this picture is + + + align:start position:0% +membrane and what this picture is +showing that this membrane is just + + align:start position:0% +showing that this membrane is just + + + align:start position:0% +showing that this membrane is just +absolutely studded with membrane + + align:start position:0% +absolutely studded with membrane + + + align:start position:0% +absolutely studded with membrane +proteins that are going to carry out + + align:start position:0% +proteins that are going to carry out + + + align:start position:0% +proteins that are going to carry out +very F various functions and here + + align:start position:0% +very F various functions and here + + + align:start position:0% +very F various functions and here +actually we're seeing that that motor + + align:start position:0% +actually we're seeing that that motor + + + align:start position:0% +actually we're seeing that that motor +which is embedded both in the inner and + + align:start position:0% +which is embedded both in the inner and + + + align:start position:0% +which is embedded both in the inner and +outer membrane and there's the the motor + + align:start position:0% +outer membrane and there's the the motor + + + align:start position:0% +outer membrane and there's the the motor +going off but a couple of things maybe + + align:start position:0% +going off but a couple of things maybe + + + align:start position:0% +going off but a couple of things maybe +you can take home from this there's a + + align:start position:0% +you can take home from this there's a + + + align:start position:0% +you can take home from this there's a +lot of membrane proteins a lot of + + align:start position:0% +lot of membrane proteins a lot of + + + align:start position:0% +lot of membrane proteins a lot of +proteins stuck in those membranes that + + align:start position:0% +proteins stuck in those membranes that + + + align:start position:0% +proteins stuck in those membranes that +control what goes in and out you also + + align:start position:0% +control what goes in and out you also + + + align:start position:0% +control what goes in and out you also +get a sense from here of how crowded the + + align:start position:0% +get a sense from here of how crowded the + + + align:start position:0% +get a sense from here of how crowded the +cytoplasm in is the proteins are really + + align:start position:0% +cytoplasm in is the proteins are really + + + align:start position:0% +cytoplasm in is the proteins are really +at amazingly high concentrations when + + align:start position:0% +at amazingly high concentrations when + + + align:start position:0% +at amazingly high concentrations when +they're in inside of the the uh the + + align:start position:0% +they're in inside of the the uh the + + + align:start position:0% +they're in inside of the the uh the +cytoplasm Okay so we've talked up till + + align:start position:0% +cytoplasm Okay so we've talked up till + + + align:start position:0% +cytoplasm Okay so we've talked up till +that's sort of a quick + + align:start position:0% +that's sort of a quick + + + align:start position:0% +that's sort of a quick +survey it's nothing more than a really + + align:start position:0% +survey it's nothing more than a really + + + align:start position:0% +survey it's nothing more than a really +superficial introduction to the four + + align:start position:0% +superficial introduction to the four + + + align:start position:0% +superficial introduction to the four +classes of of biomolecules but to go uh + + align:start position:0% +classes of of biomolecules but to go uh + + + align:start position:0% +classes of of biomolecules but to go uh +any further we're going to have to think + + align:start position:0% +any further we're going to have to think + + + align:start position:0% +any further we're going to have to think +a little bit about now the + + align:start position:0% +a little bit about now the + + + align:start position:0% +a little bit about now the +characteristics of living cells now I + + align:start position:0% +characteristics of living cells now I + + + align:start position:0% +characteristics of living cells now I +don't know if any of you know what this + + align:start position:0% +don't know if any of you know what this + + + align:start position:0% +don't know if any of you know what this +is but uh this is baker's yeast but you + + align:start position:0% +is but uh this is baker's yeast but you + + + align:start position:0% +is but uh this is baker's yeast but you +if you were making bread you know you + + align:start position:0% +if you were making bread you know you + + + align:start position:0% +if you were making bread you know you +put some yeast in it and it divides and + + align:start position:0% +put some yeast in it and it divides and + + + align:start position:0% +put some yeast in it and it divides and +it gives out carbon dioxide as a waste + + align:start position:0% +it gives out carbon dioxide as a waste + + + align:start position:0% +it gives out carbon dioxide as a waste +product and makes the the um the yeast + + align:start position:0% +product and makes the the um the yeast + + + align:start position:0% +product and makes the the um the yeast +uh makes the bread rise and what's + + align:start position:0% +uh makes the bread rise and what's + + + align:start position:0% +uh makes the bread rise and what's +happened in that little movie you just + + align:start position:0% +happened in that little movie you just + + + align:start position:0% +happened in that little movie you just +saw where two cells dividing to give + + align:start position:0% +saw where two cells dividing to give + + + align:start position:0% +saw where two cells dividing to give +four and four dividing to give eight and + + align:start position:0% +four and four dividing to give eight and + + + align:start position:0% +four and four dividing to give eight and +I don't know what we're up to here but + + align:start position:0% +I don't know what we're up to here but + + + align:start position:0% +I don't know what we're up to here but +um you can see a cell grow that's sped + + align:start position:0% +um you can see a cell grow that's sped + + + align:start position:0% +um you can see a cell grow that's sped +up it takes um probably something closer + + align:start position:0% +up it takes um probably something closer + + + align:start position:0% +up it takes um probably something closer +to an hour for a cell division to take + + align:start position:0% +to an hour for a cell division to take + + + align:start position:0% +to an hour for a cell division to take +place but this is the kind of thing that + + align:start position:0% +place but this is the kind of thing that + + + align:start position:0% +place but this is the kind of thing that +microorganisms do when they grow is you + + align:start position:0% +microorganisms do when they grow is you + + + align:start position:0% +microorganisms do when they grow is you +can start with a single + + align:start position:0% +can start with a single + + + align:start position:0% +can start with a single +cell and it will make two cells that are + + align:start position:0% +cell and it will make two cells that are + + + align:start position:0% +cell and it will make two cells that are +identical to + + align:start position:0% +identical to + + + align:start position:0% +identical to +itself and those will + + align:start position:0% +itself and those will + + + align:start position:0% +itself and those will +make four and what happen happens when + + align:start position:0% +make four and what happen happens when + + + align:start position:0% +make four and what happen happens when +we start out as a single cell we start + + align:start position:0% +we start out as a single cell we start + + + align:start position:0% +we start out as a single cell we start +out initially like this and we make + + align:start position:0% +out initially like this and we make + + + align:start position:0% +out initially like this and we make +cells that are identical at the + + align:start position:0% +cells that are identical at the + + + align:start position:0% +cells that are identical at the +beginning and those are the famous + + align:start position:0% +beginning and those are the famous + + + align:start position:0% +beginning and those are the famous +embryonic stem cells because at this + + align:start position:0% +embryonic stem cells because at this + + + align:start position:0% +embryonic stem cells because at this +point they can become any cell in your + + align:start position:0% +point they can become any cell in your + + + align:start position:0% +point they can become any cell in your +body and if if you're a yeast it doesn't + + align:start position:0% +body and if if you're a yeast it doesn't + + + align:start position:0% +body and if if you're a yeast it doesn't +matter everything you make is the same + + align:start position:0% +matter everything you make is the same + + + align:start position:0% +matter everything you make is the same +if it's if it's one of it's a human once + + align:start position:0% +if it's if it's one of it's a human once + + + align:start position:0% +if it's if it's one of it's a human once +you start dividing at some point cells + + align:start position:0% +you start dividing at some point cells + + + align:start position:0% +you start dividing at some point cells +are going to have to start making + + align:start position:0% +are going to have to start making + + + align:start position:0% +are going to have to start making +decisions and they're going to have to + + align:start position:0% +decisions and they're going to have to + + + align:start position:0% +decisions and they're going to have to +start the progyny will have to start to + + align:start position:0% +start the progyny will have to start to + + + align:start position:0% +start the progyny will have to start to +be different of each other so that you + + align:start position:0% +be different of each other so that you + + + align:start position:0% +be different of each other so that you +can have something that's an eye and + + align:start position:0% +can have something that's an eye and + + + align:start position:0% +can have something that's an eye and +another cell that's in the liver and so + + align:start position:0% +another cell that's in the liver and so + + + align:start position:0% +another cell that's in the liver and so +on and we'll talk a little bit about + + align:start position:0% +on and we'll talk a little bit about + + + align:start position:0% +on and we'll talk a little bit about +that as we go on but the major Point uh + + align:start position:0% +that as we go on but the major Point uh + + + align:start position:0% +that as we go on but the major Point uh +right at this point is that all of life + + align:start position:0% +right at this point is that all of life + + + align:start position:0% +right at this point is that all of life +involves one cell dividing and giving a + + align:start position:0% +involves one cell dividing and giving a + + + align:start position:0% +involves one cell dividing and giving a +couple of other cells and then those + + align:start position:0% +couple of other cells and then those + + + align:start position:0% +couple of other cells and then those +going on so um these cells as we said + + align:start position:0% +going on so um these cells as we said + + + align:start position:0% +going on so um these cells as we said +characteristics of of organisms which + + align:start position:0% +characteristics of of organisms which + + + align:start position:0% +characteristics of of organisms which +are to be true there at their cellular + + align:start position:0% +are to be true there at their cellular + + + align:start position:0% +are to be true there at their cellular +level as well is that they carry out + + align:start position:0% +level as well is that they carry out + + + align:start position:0% +level as well is that they carry out +metabolism they undergo regulated growth + + align:start position:0% +metabolism they undergo regulated growth + + + align:start position:0% +metabolism they undergo regulated growth +and you have a nice example of yeast + + align:start position:0% +and you have a nice example of yeast + + + align:start position:0% +and you have a nice example of yeast +undergoing regulated growth and they + + align:start position:0% +undergoing regulated growth and they + + + align:start position:0% +undergoing regulated growth and they +reproduce which in the case of a single + + align:start position:0% +reproduce which in the case of a single + + + align:start position:0% +reproduce which in the case of a single +celled organism is the same is the same + + align:start position:0% +celled organism is the same is the same + + + align:start position:0% +celled organism is the same is the same +as cell division for us reproducing is a + + align:start position:0% +as cell division for us reproducing is a + + + align:start position:0% +as cell division for us reproducing is a +lot more complicated because we have to + + align:start position:0% +lot more complicated because we have to + + + align:start position:0% +lot more complicated because we have to +make a whole other mic uh whole other uh + + align:start position:0% +make a whole other mic uh whole other uh + + + align:start position:0% +make a whole other mic uh whole other uh +multicellular organism where the the uh + + align:start position:0% +multicellular organism where the the uh + + + align:start position:0% +multicellular organism where the the uh +cells have differentiated functions but + + align:start position:0% +cells have differentiated functions but + + + align:start position:0% +cells have differentiated functions but +the point about that is there has to be + + align:start position:0% +the point about that is there has to be + + + align:start position:0% +the point about that is there has to be +an unbelievable amount of + + align:start position:0% +an unbelievable amount of + + + align:start position:0% +an unbelievable amount of +synthesis the DNA in our body we start + + align:start position:0% +synthesis the DNA in our body we start + + + align:start position:0% +synthesis the DNA in our body we start +out with two meters in a fertilized cell + + align:start position:0% +out with two meters in a fertilized cell + + + align:start position:0% +out with two meters in a fertilized cell +and we have uh 10 to the 14th cells by + + align:start position:0% +and we have uh 10 to the 14th cells by + + + align:start position:0% +and we have uh 10 to the 14th cells by +the time we're an adult so we've had to + + align:start position:0% +the time we're an adult so we've had to + + + align:start position:0% +the time we're an adult so we've had to +make a tremendous amount of DNA let + + align:start position:0% +make a tremendous amount of DNA let + + + align:start position:0% +make a tremendous amount of DNA let +alone protein and everything else and + + align:start position:0% +alone protein and everything else and + + + align:start position:0% +alone protein and everything else and +something almost all of you know from + + align:start position:0% +something almost all of you know from + + + align:start position:0% +something almost all of you know from +your engineering background at this + + align:start position:0% +your engineering background at this + + + align:start position:0% +your engineering background at this +place is that you need energy in order + + align:start position:0% +place is that you need energy in order + + + align:start position:0% +place is that you need energy in order +to + + align:start position:0% +to + + + align:start position:0% +to +synthesize uh synthesize uh material and + + align:start position:0% +synthesize uh synthesize uh material and + + + align:start position:0% +synthesize uh synthesize uh material and +what will uh start to to talk about in + + align:start position:0% +what will uh start to to talk about in + + + align:start position:0% +what will uh start to to talk about in +the in the next phase of this uh of this + + align:start position:0% +the in the next phase of this uh of this + + + align:start position:0% +the in the next phase of this uh of this +course then is how do cells make uh make + + align:start position:0% +course then is how do cells make uh make + + + align:start position:0% +course then is how do cells make uh make +energy and how do they uh carry out + + align:start position:0% +energy and how do they uh carry out + + + align:start position:0% +energy and how do they uh carry out +metabolism so I'm going to just before + + align:start position:0% +metabolism so I'm going to just before + + + align:start position:0% +metabolism so I'm going to just before +we do that I'll introduce to you very + + align:start position:0% +we do that I'll introduce to you very + + + align:start position:0% +we do that I'll introduce to you very +quickly to close out here two classes of + + align:start position:0% +quickly to close out here two classes of + + + align:start position:0% +quickly to close out here two classes of +cells of organisms we find in in nature + + align:start position:0% +cells of organisms we find in in nature + + + align:start position:0% +cells of organisms we find in in nature +we find uh organisms that are known as + + align:start position:0% +we find uh organisms that are known as + + + align:start position:0% +we find uh organisms that are known as +autot tropes these are certain + + align:start position:0% +autot tropes these are certain + + + align:start position:0% +autot tropes these are certain +bacteria and they're able to make + + align:start position:0% +bacteria and they're able to make + + + align:start position:0% +bacteria and they're able to make +everything they + + align:start position:0% + + + + align:start position:0% + +need starting with + + align:start position:0% +need starting with + + + align:start position:0% +need starting with +CO2 + + align:start position:0% +CO2 + + + align:start position:0% +CO2 +ammonia + + align:start position:0% +ammonia + + + align:start position:0% +ammonia +phosphate + + align:start position:0% +phosphate + + + align:start position:0% +phosphate +water a few things but that's all they + + align:start position:0% +water a few things but that's all they + + + align:start position:0% +water a few things but that's all they +need so for for example an organism that + + align:start position:0% +need so for for example an organism that + + + align:start position:0% +need so for for example an organism that +lives a bacterium that lives out in the + + align:start position:0% +lives a bacterium that lives out in the + + + align:start position:0% +lives a bacterium that lives out in the +open ocean is able to make everything + + align:start position:0% +open ocean is able to make everything + + + align:start position:0% +open ocean is able to make everything +from those very very simple basic uh + + align:start position:0% +from those very very simple basic uh + + + align:start position:0% +from those very very simple basic uh +building + + align:start position:0% +building + + + align:start position:0% +building +blocks heterotrofos + + align:start position:0% + + + + align:start position:0% + +need to + + align:start position:0% + + + + align:start position:0% + +eat some things + + align:start position:0% + + + + align:start position:0% + +made by other organisms + + align:start position:0% + + + + align:start position:0% + +example of a heter trro uh that you're + + align:start position:0% +example of a heter trro uh that you're + + + align:start position:0% +example of a heter trro uh that you're +familiar with I'm familiar with is US + + align:start position:0% +familiar with I'm familiar with is US + + + align:start position:0% +familiar with I'm familiar with is US +probably remember your mother uh + + align:start position:0% +probably remember your mother uh + + + align:start position:0% +probably remember your mother uh +reminding you as you about to have yet + + align:start position:0% +reminding you as you about to have yet + + + align:start position:0% +reminding you as you about to have yet +another hot dog that it was important to + + align:start position:0% +another hot dog that it was important to + + + align:start position:0% +another hot dog that it was important to +eat your vitamins the reason you need to + + align:start position:0% +eat your vitamins the reason you need to + + + align:start position:0% +eat your vitamins the reason you need to +vitamins those are things we absolutely + + align:start position:0% +vitamins those are things we absolutely + + + align:start position:0% +vitamins those are things we absolutely +need for our life but we can't um make + + align:start position:0% +need for our life but we can't um make + + + align:start position:0% +need for our life but we can't um make +them ourselves uh vitamin C is one you + + align:start position:0% +them ourselves uh vitamin C is one you + + + align:start position:0% +them ourselves uh vitamin C is one you +probably know it has an interesting + + align:start position:0% +probably know it has an interesting + + + align:start position:0% +probably know it has an interesting +history how people figured this out it + + align:start position:0% +history how people figured this out it + + + align:start position:0% +history how people figured this out it +was Sailors at Sea got really really + + align:start position:0% +was Sailors at Sea got really really + + + align:start position:0% +was Sailors at Sea got really really +sick their teeth would start to loosen + + align:start position:0% +sick their teeth would start to loosen + + + align:start position:0% +sick their teeth would start to loosen +they would start to bleed and they would + + align:start position:0% +they would start to bleed and they would + + + align:start position:0% +they would start to bleed and they would +die um and some of the famous sea + + align:start position:0% +die um and some of the famous sea + + + align:start position:0% +die um and some of the famous sea +voyages you heard about in high in high + + align:start position:0% +voyages you heard about in high in high + + + align:start position:0% +voyages you heard about in high in high +school were very I think the Cape of + + align:start position:0% +school were very I think the Cape of + + + align:start position:0% +school were very I think the Cape of +Good Hope on the trip where that was + + align:start position:0% +Good Hope on the trip where that was + + + align:start position:0% +Good Hope on the trip where that was +discovered 100 out of the 160 Sailors + + align:start position:0% +discovered 100 out of the 160 Sailors + + + align:start position:0% +discovered 100 out of the 160 Sailors +died at Sea because of scurvy now scurvy + + align:start position:0% +died at Sea because of scurvy now scurvy + + + align:start position:0% +died at Sea because of scurvy now scurvy +turns out to be due to not not having + + align:start position:0% +turns out to be due to not not having + + + align:start position:0% +turns out to be due to not not having +vitamin C and there was uh finally a guy + + align:start position:0% +vitamin C and there was uh finally a guy + + + align:start position:0% +vitamin C and there was uh finally a guy +about the + + align:start position:0% +about the + + + align:start position:0% +about the +um Lind I'm just blanking on his first + + align:start position:0% +um Lind I'm just blanking on his first + + + align:start position:0% +um Lind I'm just blanking on his first +uh name uh at the moment uh about the + + align:start position:0% +uh name uh at the moment uh about the + + + align:start position:0% +uh name uh at the moment uh about the +1700s who was a naval surgeon in the + + align:start position:0% +1700s who was a naval surgeon in the + + + align:start position:0% +1700s who was a naval surgeon in the +British Navy and actually figured out + + align:start position:0% +British Navy and actually figured out + + + align:start position:0% +British Navy and actually figured out +that if you gave Sailors lemon juice + + align:start position:0% +that if you gave Sailors lemon juice + + + align:start position:0% +that if you gave Sailors lemon juice +that they didn't get scurvy it was a + + align:start position:0% +that they didn't get scurvy it was a + + + align:start position:0% +that they didn't get scurvy it was a +controlled experiment it took about uh + + align:start position:0% +controlled experiment it took about uh + + + align:start position:0% +controlled experiment it took about uh +50 years I think it was 1795 when they + + align:start position:0% +50 years I think it was 1795 when they + + + align:start position:0% +50 years I think it was 1795 when they +started to finally give the sailors + + align:start position:0% +started to finally give the sailors + + + align:start position:0% +started to finally give the sailors +lemon juice and stopped having this + + align:start position:0% +lemon juice and stopped having this + + + align:start position:0% +lemon juice and stopped having this +terrible sickness amongst their Sailors + + align:start position:0% +terrible sickness amongst their Sailors + + + align:start position:0% +terrible sickness amongst their Sailors +and then in about 1850 they substituted + + align:start position:0% +and then in about 1850 they substituted + + + align:start position:0% +and then in about 1850 they substituted +lime juice and some of you may still + + align:start position:0% +lime juice and some of you may still + + + align:start position:0% +lime juice and some of you may still +know the British Sailors are called + + align:start position:0% +know the British Sailors are called + + + align:start position:0% +know the British Sailors are called +called limes and that was because of of + + align:start position:0% +called limes and that was because of of + + + align:start position:0% +called limes and that was because of of +uh this solution they found to avoiding + + align:start position:0% +uh this solution they found to avoiding + + + align:start position:0% +uh this solution they found to avoiding +scurvy and what was really happening was + + align:start position:0% +scurvy and what was really happening was + + + align:start position:0% +scurvy and what was really happening was +they were finding a way to provide + + align:start position:0% +they were finding a way to provide + + + align:start position:0% +they were finding a way to provide +vitamin C which is in fresh fruits and + + align:start position:0% +vitamin C which is in fresh fruits and + + + align:start position:0% +vitamin C which is in fresh fruits and +vegetables which wasn't part of the + + align:start position:0% +vegetables which wasn't part of the + + + align:start position:0% +vegetables which wasn't part of the +classic sailor diet which was sort of + + align:start position:0% +classic sailor diet which was sort of + + + align:start position:0% +classic sailor diet which was sort of +biscuits and and dried meat during long + + align:start position:0% +biscuits and and dried meat during long + + + align:start position:0% +biscuits and and dried meat during long +voyages at Sea there's several other + + align:start position:0% +voyages at Sea there's several other + + + align:start position:0% +voyages at Sea there's several other +vitamins but the reason they're called + + align:start position:0% +vitamins but the reason they're called + + + align:start position:0% +vitamins but the reason they're called +vitamins are things that your body can't + + align:start position:0% +vitamins are things that your body can't + + + align:start position:0% +vitamins are things that your body can't +make but other organisms can the other + + align:start position:0% +make but other organisms can the other + + + align:start position:0% +make but other organisms can the other +thing that + + align:start position:0% +thing that + + + align:start position:0% +thing that +we that we can't make we can make some + + align:start position:0% +we that we can't make we can make some + + + align:start position:0% +we that we can't make we can make some +of our 20 amino acids but there are + + align:start position:0% +of our 20 amino acids but there are + + + align:start position:0% +of our 20 amino acids but there are +eight uh amino acids that um that we + + align:start position:0% +eight uh amino acids that um that we + + + align:start position:0% +eight uh amino acids that um that we +can't make um + + align:start position:0% + + + + align:start position:0% + +lysine + + align:start position:0% +lysine + + + align:start position:0% +lysine +methionine + + align:start position:0% +methionine + + + align:start position:0% +methionine +Lucine + + align:start position:0% +Lucine + + + align:start position:0% +Lucine +isoline + + align:start position:0% +isoline + + + align:start position:0% +isoline +veine + + align:start position:0% +veine + + + align:start position:0% +veine +thine phenyalanine + + align:start position:0% +thine phenyalanine + + + align:start position:0% +thine phenyalanine +and tryptophane and this actually has + + align:start position:0% +and tryptophane and this actually has + + + align:start position:0% +and tryptophane and this actually has +consequences uh for us because um there + + align:start position:0% +consequences uh for us because um there + + + align:start position:0% +consequences uh for us because um there +are those of you who are vegetarians + + align:start position:0% +are those of you who are vegetarians + + + align:start position:0% +are those of you who are vegetarians +probably know you have to be kind of + + align:start position:0% +probably know you have to be kind of + + + align:start position:0% +probably know you have to be kind of +careful about your diet if you're eating + + align:start position:0% +careful about your diet if you're eating + + + align:start position:0% +careful about your diet if you're eating +animal protein um you're getting + + align:start position:0% +animal protein um you're getting + + + align:start position:0% +animal protein um you're getting +essentially all the different amino + + align:start position:0% +essentially all the different amino + + + align:start position:0% +essentially all the different amino +acids but if you uh if you're a + + align:start position:0% +acids but if you uh if you're a + + + align:start position:0% +acids but if you uh if you're a +vegetarian you have to be careful + + align:start position:0% +vegetarian you have to be careful + + + align:start position:0% +vegetarian you have to be careful +because the major + + align:start position:0% +because the major + + + align:start position:0% +because the major +uh food crops such as wheat and and rice + + align:start position:0% +uh food crops such as wheat and and rice + + + align:start position:0% +uh food crops such as wheat and and rice +for example are very low in lysing so if + + align:start position:0% +for example are very low in lysing so if + + + align:start position:0% +for example are very low in lysing so if +you just eat those you end up with uh a + + align:start position:0% +you just eat those you end up with uh a + + + align:start position:0% +you just eat those you end up with uh a +lysine deficiency that's that's not good + + align:start position:0% +lysine deficiency that's that's not good + + + align:start position:0% +lysine deficiency that's that's not good +but on the other hand beans lentils the + + align:start position:0% +but on the other hand beans lentils the + + + align:start position:0% +but on the other hand beans lentils the +various leguminous plants were also + + align:start position:0% +various leguminous plants were also + + + align:start position:0% +various leguminous plants were also +which also those ones that form the + + align:start position:0% +which also those ones that form the + + + align:start position:0% +which also those ones that form the +special associations with bacteria that + + align:start position:0% +special associations with bacteria that + + + align:start position:0% +special associations with bacteria that +let them convert atmospheric um nitrogen + + align:start position:0% +let them convert atmospheric um nitrogen + + + align:start position:0% +let them convert atmospheric um nitrogen +into ammonia those legumes are high in + + align:start position:0% +into ammonia those legumes are high in + + + align:start position:0% +into ammonia those legumes are high in +lysine but low in methionine so uh + + align:start position:0% +lysine but low in methionine so uh + + + align:start position:0% +lysine but low in methionine so uh +peoples all over the world figured this + + align:start position:0% +peoples all over the world figured this + + + align:start position:0% +peoples all over the world figured this +out by trial and error so um the Mexican + + align:start position:0% +out by trial and error so um the Mexican + + + align:start position:0% +out by trial and error so um the Mexican +diet is you know rice and beans there's + + align:start position:0% +diet is you know rice and beans there's + + + align:start position:0% +diet is you know rice and beans there's +a reason for it what's happening + + align:start position:0% +a reason for it what's happening + + + align:start position:0% +a reason for it what's happening +actually is you're just in the rice + + align:start position:0% +actually is you're just in the rice + + + align:start position:0% +actually is you're just in the rice +you're low and lysine but by having + + align:start position:0% +you're low and lysine but by having + + + align:start position:0% +you're low and lysine but by having +beans at the same time you're balancing + + align:start position:0% +beans at the same time you're balancing + + + align:start position:0% +beans at the same time you're balancing +out the two or the the native um + + align:start position:0% +out the two or the the native um + + + align:start position:0% +out the two or the the native um +Americans in in this part of of the + + align:start position:0% +Americans in in this part of of the + + + align:start position:0% +Americans in in this part of of the +country had the three sisters with the + + align:start position:0% +country had the three sisters with the + + + align:start position:0% +country had the three sisters with the +corn the squash and the beans and again + + align:start position:0% +corn the squash and the beans and again + + + align:start position:0% +corn the squash and the beans and again +they were balancing out the diet by + + align:start position:0% +they were balancing out the diet by + + + align:start position:0% +they were balancing out the diet by +making sure that they got the various + + align:start position:0% +making sure that they got the various + + + align:start position:0% +making sure that they got the various +amino acids uh a balance of all the + + align:start position:0% +amino acids uh a balance of all the + + + align:start position:0% +amino acids uh a balance of all the +amino acids that were necessary uh for + + align:start position:0% +amino acids that were necessary uh for + + + align:start position:0% +amino acids that were necessary uh for +life it also actually was really good + + align:start position:0% +life it also actually was really good + + + align:start position:0% +life it also actually was really good +gardening practice because the beans + + align:start position:0% +gardening practice because the beans + + + align:start position:0% +gardening practice because the beans +were able to convert atmospheric + + align:start position:0% +were able to convert atmospheric + + + align:start position:0% +were able to convert atmospheric +nitrogen into ammonia which was + + align:start position:0% +nitrogen into ammonia which was + + + align:start position:0% +nitrogen into ammonia which was +fertilizer and the squash leaves shaded + + align:start position:0% +fertilizer and the squash leaves shaded + + + align:start position:0% +fertilizer and the squash leaves shaded +the the ground so the ground didn't dry + + align:start position:0% +the the ground so the ground didn't dry + + + align:start position:0% +the the ground so the ground didn't dry +out and the corn could grow even when it + + align:start position:0% +out and the corn could grow even when it + + + align:start position:0% +out and the corn could grow even when it +was short on on + + align:start position:0% +was short on on + + + align:start position:0% +was short on on +uh on water but what was really + + align:start position:0% +uh on water but what was really + + + align:start position:0% +uh on water but what was really +happening in these as as people grew + + align:start position:0% +happening in these as as people grew + + + align:start position:0% +happening in these as as people grew +without even understanding the + + align:start position:0% +without even understanding the + + + align:start position:0% +without even understanding the +biochemistry they were compensating for + + align:start position:0% +biochemistry they were compensating for + + + align:start position:0% +biochemistry they were compensating for +the fact that were heterotrophs and + + align:start position:0% +the fact that were heterotrophs and + + + align:start position:0% +the fact that were heterotrophs and +needed to to do this so we'll start in + + align:start position:0% +needed to to do this so we'll start in + + + align:start position:0% +needed to to do this so we'll start in +uh at the next lecture on trying to talk + + align:start position:0% +uh at the next lecture on trying to talk + + + align:start position:0% +uh at the next lecture on trying to talk +about how cells make energy and how it + + align:start position:0% +about how cells make energy and how it + + + align:start position:0% +about how cells make energy and how it +makes some of this amazing stuff + + align:start position:0% + + + + align:start position:0% + +happen \ No newline at end of file diff --git a/6HrTfI8R_9A.txt b/6HrTfI8R_9A.txt new file mode 100644 index 0000000000000000000000000000000000000000..df170ef7844e31243cdeab0fb2d7d08de3777e98 --- /dev/null +++ b/6HrTfI8R_9A.txt @@ -0,0 +1,3061 @@ +The following +content is provided + +under a Creative +Commons license. + +Your support will help MIT +OpenCourseWare continue + +to offer high quality +educational resources for free. + +To make a donation or +view additional materials + +from hundreds of MIT courses, +visit MIT OpenCourseWare + +at ocw.mit.edu. + +OK, let's start. + +So let's go back to +our starting point + +for the past couple of weeks. + +The square lattice, let's +say, where each side + +we assign a binary variable +sigma, which is minus 1. + +And a weight that tends +to make subsequent nearest + +neighbors [? things ?] to +be parallel to each other. + +So into the plus k, +they are parallel. + +Penalized into the minus k +if they are anti-parallel. + +And of course, over all +pairs of nearest neighbors. + +And the partition function that +is obtained by summing over 2 + +to the n configurations. + +Let's make this up +to give us a function + +of the rate of this +coupling, which + +is some energy provided +by temperature. + +And we expect this-- at least, +in two and higher dimensions-- + +to capture a phase transition. + +And the way that we have +been proceeding with this + +to derive this factor as +the hyperbolic cosine of k. + +1 plus r variable t, which is +the hyperbolic [? sine ?] of k. + +Sigma i, sigma j. + +And then this becomes +a cos k to the number + +of bonds, which is 2n +on the square lattice. + +And then expanding +these factors, + +we saw that we could get +things that are either + +1 from each bond +or a factor that + +was something like +t sigma sigma. + +And then summing over +the two values of sigma + +would give us 0 unless we +added another factor of sigma + +through another bond. + +And going forth, we had to +draw these kinds of diagrams + +where at each site, I have an +even number of 1's selected. + +Then summing over the sigmas +would give me a factor of 2 + +to the n. + +And so then I have a sum over a +whole bunch of configurations. + +[? There are ?] +[? certainly ?] one. + +There are configurations +that are composed + +of one way of drawing +an object on the lattice + +such as this one, +or objects that + +correspond to doing two of +these loops, and so forth. + +So that's the expression +for the partition function. + +And what we are +really interested + +is the log of the partition +function, which gives us + +the free energy in terms +of thermodynamic quantities + +that potentially will tell +us about phase transition. + +So here we will get +a log 2 to the n. + +Well actually, you want +to divide everything by n + +so that we get the +intensive part. + +So here we get log 2 +hyperbolic cosine squared of k. + +And then I have to take the +log of this expression that + +includes things +that are one loop, + +disjointed loop, et cetera. + +And we've seen that +the particular loop + +I can slide all over the place-- +so if you have a factor of n-- + +whereas things that +are multiple loops + +have factors of n +squared, et cetera, + +which are incompatible +with this. + +So it was very tempting for +us to do the usual thing + +and say that the +log of a sum that + +includes these multiple +occurrences of the loops + +is the same thing as sum +over the configurations + +that involve a single loop. + +And then we have to sum over +all shapes of these loops. + +And each loop will +get a factor of t + +per the number of bonds +that are occurring in that. + +Of course, what we said was +that this equality does not + +hold because if I +exponentiate this term, + +I will generate things where +the different loops will + +coincide with each +other, and therefore + +create types of terms that are +not created in the original sum + +that we had over there. + +So this sum over phantom +loops neglected the condition + +that these loops, in some sense, +have some material to them + +and don't want to +intersect with each other. + +Nonetheless, it was +useful, and we followed up + +this calculation. + +So that's repeat what the result +of this incorrect calculation + +is. + +So we have log of 2 hyperbolic +cosine squared k, 1 over n. + +Then we said the +particular way to organize + +the sum over the +loops is to sum over + +there the length of the loop. + +So I sum over the +length of the loop + +and count the number of +loops that have length l. + +All of them will be +giving me a contribution + +that is t to the l. + +So then I said, well, +let's, for example, + +pick a particular +point on the lattice. + +Let's call it r. + +And I count the number of +ways that I can start at r, + +do a walk of l steps, +and end at r again. + +We saw that for +these phantom loops, + +this w had a very +nice structure. + +It was simply what +was telling me + +about one step raised to the l. + +This was the Markovian property. + +There was, of course, +an important thing here + +which said that I could have +set the origin of this loop + +at any point along the loop. + +So there is an over-counting +by a factor of l + +because the same loop +would have been constructed + +with different points +indicated as the origin. + +And actually, I can go the loop +clockwise or anti-clockwise, + +so there was a factor of 2 +because of this degeneracy + +of going clockwise or +anti-clockwise when + +I perform a walk. + +And then over here, there's +also an implicit sum + +over this starting +point and endpoint. + +If I always start and +end at the origin, + +then I will get rid +of the factor of n. + +But it is useful to +explicitly include + +this sum over r because +then you can explicitly + +see that sum over +r of this object + +is the trace of that matrix. + +And I can actually +[INAUDIBLE] the order, + +the trace, and the +summation over l. + +And when that happens, I get +log 2 cos squared k exactly + +as before. + +And then I have 1 over n. + +I have sum over r replaced +by the trace operation. + +And then sum over l-- t, T +raised to the l divided by + +l-- is the expansion for +minus log of 1 minus t T. + +And there's the +factor of 2 over there + +that I have to put over here. + +So note that this +plus became minus + +because of the expansion +for log of 1 minus + +x is minus x minus +x squared over 2 + +minus x cubed over 3, et cetera. + +And the final step +that we did was + +to note that the trace I +can calculate in any basis. + +And in particular, this +matrix t is diagonalized + +by going to Fourier +representation. + +In the Fourier representation, +the trace operation + +becomes sum over all q values. + +Sum over all q values, +I go to the continuum + +and write as n integral +over q, so the n's cancel. + +I will get 2 integration over q. + +These are essentially each +one of them, qz and qz, + +in the interval. + +Let's say 0 to 2 pi or minus +pi to 2 pi, doesn't matter. + +Interval of size of 2pi. + +So that's the trace operation. + +Log of 1 minus t. + +Then the matrix that represents +walking along the lattice + +represented in Fourier. + +And so basically at +the particular site, + +we can step to the +right or to the left. + +So that's e to the i qx, e to +the minus i qx, e to the i qy, + +e to the minus i qy. + +Adding all of those up, +you get 2 cosine of qz + +plus cosine of qy. + +So that was our expression. + +And then we realized, +interestingly, + +that whereas this final +expression certainly + +was not the Ising partition +function that we were after, + +that it was, in +fact, the partition + +function of a Gaussian +model where at each site + +I had a variable +whose variance was 1, + +and then I had this +kind of coupling + +rather than with +the sigma variable, + +with these Gaussian +variables that + +will go from minus to infinity. + +But then we said, OK, we +can do better than that. + +And we said that log +z over n actually + +does equal a very similar sum. + +It is log 2 hyperbolic +cosine squared k, + +and then I have 1 over n. + +Sum over all kinds +of loops where + +I have a similar diagram that +I draw, but I put a star. + +And this star +implied two things-- + +that just like before, I draw +all kinds of individual loops, + +but I make sure +that my loops never + +have a step that goes +forward and backward. + +So there was no U-turn. + +And importantly, there +was a factor of minus 1 + +to the number of times that +the walk crossed itself. + +And we showed that +when we incorporate + +both of these conditions, +the can indeed + +exponentiate this expression and +get exactly the same diagrams + +as we had on the +first line, all coming + +with the correct +weights, and none + +of the diagrams that had +multiple occurrences of a bond + +would occur. + +So then the question +was, how do you + +calculate this +given that we have + +this dependence on the number +of crossings, which offhand may + +look as if it is something +that requires memory? + +And then we saw that, indeed, +just like the previous case, + +we could write the +result as a sum over + +walks that have a +particular length l. + +Right here, we have the +factor of t to the l. + +Those walks could start and +end at the particular point r. + +But we also specified +the direction mu + +along which you started. + +So previously I only +specified the origin. + +Now I have to specify the +starting point as well + +as the direction. + +I have to end at the same point +and along the same direction + +to complete the loop. + +And these were accomplished by +having these factors of walks + +that are length l. + +So to do that, we can certainly +incorporate this condition + +of no U-turn in the description +of the steps that I take. + +So for each step, I +know where I came from. + +I just make sure I don't +step back, so that's easy. + +And we found that this +minus 1 to the power of nc + +can be incorporated +through a factor of e + +to the i sum over the changes of +the orientation of the walker-- + +as I step through the lattice-- +provided that I included also + +an additional factor of minus. + +So that factor of minus I +could actually put out front. + +It's an important factor. + +And then there's +the over-counting, + +but as before, the walk can go +in either one of two directions + +and can have l starting points. + +OK, so now we can +proceed just as before. + +log 2 hyperbolic +cosine squared k, + +and then we have +a sum over l here, + +which we can, again, represent +as the log of 1 minus + +t-- this 4 by 4 matrix t star. + +Going through the log +operation will change this sign + +from minus to plus. + +I have the 1 over 2n as before. + +And I have to sum over r and +mu, which are the elements that + +characterize this +4n by 4n matrix. + +So this amounts to doing +the trace log operation. + +And then taking advantage of +the fact that, just as before, + +Fourier transforms can +at least partially block + +diagonalize this +4n by 4n matrix. + +I go to that basis, +and the trace + +becomes an integral over q. + +And then I would have to do +the trace of a log of a 4 + +by 4 matrix. + +And for that, I use the +identity that a trace + +of log of any matrix is +the log of the determinant + +of that same matrix. + +And so the thing that +I have to integrate + +is the log of the +determinant of a 4 + +by 4 matrix that +captures these steps + +that I take on the +square lattice. + +And we saw that, +for example, going + +in the horizontal direction +would give me a factor of t + +e to the minus i qx. + +Going in the vertical +direction-- up-- y qy. + +Going in the horizontal +direction-- down. + +These are the diagonal elements. + +And then there were +off-diagonal elements, + +so the next turn here was +to go and then bend upward. + +So that gave me in addition +to e to the minus i qx, + +which is the same +forward step here. + +A factor of, let's +call it omega so I + +don't have to write +it all over the place. + +Omega is e to the pi pi over 4. + +And the next one was a U-turn. + +The next one was minus t +e minus i qx omega star. + +And we could fill out similarly +all of the other places + +in this 4 by 4 matrix. + +And then the whole problem comes +down to having to evaluate a 4 + +by 4 determinant, +which you can do + +by hand with a couple of sheets +of paper to do your algebra. + +And I wrote for you +the final answer, + +is 1/2 2 integrals +from minus pi 2 pi + +over qx and qy divided +by 2 pi squared. + +And then the result of +this, which is log of 1 + +plus t squared squared minus 2t +1 minus t squared cosine of qx + +plus cosine of qy. + +This was the expression +for the partition function. + +OK, so this is where +we ended up last time. + +Now the question is we +have here on the board + +two expressions, the project +one and the incorrect one-- + +the Gaussian model and the +2-dimensionalizing one. + +They look surprisingly +similar, and that + +should start to worry us +potentially because we expect + +that many when we +have some functional + +form, that functional +form carries + +within it certain singularities. + +And you say, well, these +two functions, both of them + +are a double integral +of log of something + +minus something +cosine plus cosine. + +So after all of +this work, did we + +end up with an expression +that has the same singular + +behavior as the Gaussian model? + +OK, so let's go and look +at things more carefully. + +So in both cases, what I need +to do is to integrate A function + +a that appears inside the log. + +There is an A for the +Gaussian, and then there + +is this object-- +let's call it A star-- + +for the correct solution. + +So the thing that I have to +integrate is, of course, q. + +So this is a function +of the vector q, + +as well as the parameter that +is a function of which I expect + +to have a phase +transition, which is t. + +Now where could I potentially +get some kind of a singularity? + +The only place that I +can get a singularity + +is if the argument of the log +goes to 0 because log of 0 + +is something that's derivatives +of singularities, et cetera. + +So you may say, OK, that's +where I should be looking at. + +So where is it this +most likely to happen + +when I'm integrating over q? + +So basically, I'm +integrating over qx and qy + +over a [INAUDIBLE] +[? zone ?] that + +goes from minus pi to +pi in both directions. + +And potentially somewhere in +this I encounter a singularity. + +Let's come from the site +of high temperatures + +where t is close to 0. + +Then I have log +of 1, no problem. + +As I go to lower and +lower temperatures, + +the t becomes larger. + +Then from the 1, I start +to subtract more and more + +with these cosines. + +And clearly the place +that I'm subtracting + +most is right at the +center of q equals to 0. + +So let's expand this +in the vicinity of q + +goes to 0 in the +vicinity of this place. + +And there what I see +is it is 1 minus. + +Cosines are approximately +1 minus q squared over 2. + +So I have 1 minus +4t, and then I have + +plus t qx squared plus qy +squared, which is essentially + +the net q squared. + +And then I have order of +higher power z, qx and qy. + +Fine. + +So this part is +positive, no problem. + +I see that this +part goes through 0 + +when I hit tc, which is 1/4. + +And this we had already +seen, that basically this + +is the place where the +exponentially increasing + +number of walks-- as 4 +to the number of steps-- + +overcomes the +exponentially decreasing + +fidelity of information carried +through each walk, which + +was t to the l. + +So 4dt being 1, tc +is of the order 1/4. + +We are interested +in the singularities + +in the vicinity of +this phase transition, + +so we additionally +go and look at what + +happens when t approaches +tc, but from this side above, + +because clearly if I go to +t that is larger than 1/4, + +it doesn't make any sense. + +So t has to be less than 1/4. + +And so then what I have here is +that I can write this as 4tc, + +so this is 4 times tc minus t. + +And this to the lowest order +I can replace as tc-- q + +squared plus higher orders. + +This 4 I can write as 1 over tc. + +So the whole thing +I can write as q + +squared plus delta t divided by +tc, and there's a factor of 4. + +And delta t I have +defined to be tc minus 10. + +How close I am to the location +where this singularity takes + +places. + +So what I'm interested +is not in the whole form + +of this function, but +only the singularities + +that it expresses. + +So I focus on the singular part +of this Gaussian expression. + +I don't have to worry +about that term. + +So I have minus 1/2. + +I have double integral. + +The argument of +the log, I expanded + +in the vicinity of +the point that I + +see a singularity to take place. + +And I'll write the answer as q +squared plus 4 delta t over tc. + +If I am sufficiently close in +my integration to the origin + +so that the expansion +in q is acceptable, + +there is an additional +factor of tc. + +But if I take a log of +tc, it's just a constant. + +I can integrate that out. + +It's going to not contribute +to the singular part, just + +an additional regular component. + +Now if I am in the +vicinity of q equals to 0 + +where all of the action is, +at this order, the thing + +that I'm integrating +has circular symmetry so + +that 2-dimensional integration. + +I can write whether +or not it's d qx, d qy + +as 2 pi q dq divided +by 2 pi squared, + +which was the density of state. + +And this approximation +of a thing being + +isotropic and +circular only holds + +when I'm sufficiently +close to the origin, + +let's say up to some value +that I will call lambda. + +So I will impose +some cut-off here, + +lambda, which is +certainly less than one + +of the order of pi-- +let's say pi over 10. + +It doesn't matter what it is. + +As we will see, +the singular part, + +it ultimately does not +matter what I put for lambda. + +But the rest of the integration +that I haven't exclusively + +written down from +all of this-- again, + +in analogy to what we had seen +before for the Landau-Ginzburg + +calculation will +give me something + +that is perfectly analytic. + +So I have extracted from this +expression the singular part. + +OK, now let's do this +integral carefully. + +So what do I have? + +I have 1 over 2 pi with +minus 1/2, so I have minus 1 + +over 4 pi. + +If I call this whole +object here x-- so x is q + +squared plus this +something-- then + +we can see that dx is 2 q dq. + +So what I have to do is +the integral of dx log x, + +which is x log x minus x. + +So essentially, let's keep the +2 up there and make this 8 pi. + +And then what I have is +x log x minus x itself, + +which I can write as log of e. + +And then this whole thing has +to be evaluated between the two + +limits of integration, +lambda and [INAUDIBLE]. + +Now you explicitly see +that if I substitute + +in this expression for q +the upper part of lambda, + +it will give me +something like lambda + +squared plus delta +t-- an expandable + +and analytical function. + +Log of a constant plus delta t +that I can start analytically + +expanding. + +So anything that I get +from the other cut-off + +of the integration is +perfectly analytic. + +I don't have to worry about it. + +If I'm interested in +the singular part, + +I basically need to evaluate +this as it's lower cut-off. + +So I evaluate it +at q equals to 0. + +Well first off all, I +will get a sign change + +because I'm at +the lower cut-off. + +I will get from here +4 delta t over tc. + +And from here, I will get +log of a bunch of constants. + +It doesn't really matter. + +4 over e delta t over tc. + +What is the leading singularity? + +Is delta t log t-- log delta t? + +And so again, the +leading singularity + +is delta t log of delta t. + +There's an overall factor of 1 +over pi. [? Doesn't match. ?] + +You take two derivatives. + +You find that the +heat capacity, let's + +say that is proportion +to two derivatives of log + +z by delta t squared. + +You take one derivative, +it goes like the log. + +You take another +derivative of the log, + +you find that the singularity +is 1 over delta t. + +That corresponds to a +heat capacity divergence + +with an exponent +of unity, which is + +quite consistent with the +generally Gaussian formula + +that we had in d dimensions, +which was 2 minus t over 2. + +So that's the Gaussian. + +And of course, this +whole theory breaks down + +for t that is greater than tc. + +Once I go beyond +tc, my expressions + +just don't make sense. + +I can't integrate a lot +of a negative number. + +And we understand why that is. + +That's because we are including +all of these loops that + +can go over each +other multiple times. + +The whole theory +does not make sense. + +So we did this one to death. + +Will the exact result +be any different? + +So let's carry out the +corresponding procedure-- + +for A star that is a +function of q and t. + +And again, singularities +should come from the place + +where this is most +likely to go to 0. + +You can see it's 1 +something minus something. + +And clearly when the +q's are close to 0 + +is when you subtract +most, and you're + +likely to become negative. + +So let's expand it around 0. + +This as q goes to 0 is 1 +plus t squared squared. + +And then I have minus. + +Each one of the cosines +starts at unity, + +so I will have 4t +1 minus t squared. + +And then from the qx squared +over 2 qy squared over 2, + +I will get a plus +t 1 minus t squared + +q squared-- qx squared plus +qy squared-- plus order of q + +to the fourth. + +So the way that we identified +the location of the singular + +part before was to focus +on exactly q equals to 0. + +And what we find is that +A star at q equals to 0 + +is essentially this part. + +This part I'm going to rewrite +the first end slightly. + +1 plus t squared squared +is the same thing + +as 1 minus t squared +squared plus 4t squared. + +The difference +between the expansion + +of each one of +these two terms is + +that this has plus 2t squared, +this has minus 2t squared, + +which I have added here. + +And then minus 4t +1 minus t squared. + +And the reason +that I did that is + +that you can now see +that this term is twice + +this times this when +I take the square. + +So the whole thing is the same +thing as 1 minus t squared + +minus 2t squared. + +So the first thing that gives +us reassurance happens now, + +whereas previously for the +Gaussian model 1 minus 4t could + +be both positive and +negative, this you can see + +is always positive. + +So there is no +problem with me not + +being able to go from one +side of the phase transition + +to another side of +the phase transition. + +This expression will +encounter no difficulties. + +But there is a special +point when this thing is 0. + +So there is a point when 1 +minus 2t c plus tc squared + +is equal to 0. + +The whole thing goes to 0. + +And you can figure +out where that is. + +tc is 1. + +It's a quadratic form. + +It has two solutions-- 1 +minus plus square root of 2. + +A negative solution +is not acceptable. + +Minus. + +I have to recast this slightly. + +Knowing the answer sometimes +makes you go too fast. + +tc squared plus 2tc +minus 1 equals to 0. + +tc is minus 1 plus or +minus square root of 2. + +The minus solution +is not acceptable. + +The plus solution would +give me root 2 minus 1. + +Just to remind you, +we calculated a value + +for the critical point +based on duality. + +So let's just recap +that duality argument. + +We saw that the series +that we had calculated, + +which was an expansion in +high temperatures times k, + +reproduced the expansion that +we had for 0 temperature, + +including islands of +minus in a sea of plus, + +where the contribution of each +bond was going from e to the k + +to e to the minus k. + +So there was a correspondence +between a dual coupling. + +And the actual coupling, +that was like this. + +At a critical point, +we said the two of them + +have to be the same. + +And what we had +calculated based on that, + +since the hyperbolic +tang I can write in terms + +of the exponentials was that +the value of e to the minus + +e to the plus 2kc was, in +fact, square root of 2 plus 1. + +And the inverse of this will +be square root of 2 minus 1, + +and that's the same as the tang. + +That's the same +thing as the things + +that we have already written. + +So the calculation +that we had done + +before-- obtain this +critical temperature based + +on this Kramers-Wannier +duality-- + +gave us a critical point here, +which is precisely the place + +that we can identify as the +origin of the singularity + +in this expression. + +So what did we do next? + +The next thing that we did +was having identified up there + +where the critical point +was-- which was at 14-- + +was to expand our +A, the integrand, + +inside the log in the +vicinity of that point. + +So what I want to do +is similarly expand + +a star of q for t that +goes into vicinity of tc. + +And what do I have to do? + +So what I can do, let's write +it as t is tc plus delta t + +and make an expansion +for delta t small. + +So I have to make an expansion +or delta t small, first + +of all, of this quantity. + +So if I make a +small change in t, + +I'll have to take a +derivative inside here. + +So I have minus 2t minus +2, evaluate it at tc, + +times the change in delta t. + +So that's the change +of this expression + +if I go slightly away from +the point where it is 0. + +Yes? + +AUDIENCE: I have a question. + +T here is [? tangent ?] +of k where we calculated + +the [INAUDIBLE] to +[? be as ?] temperature. + +PROFESSOR: Now all +of these things + +are analytical +functions of each other. + +So the k is, in fact, some +unit of energy divided by kt. + +So Really, the +temperature is here. + +And my t is tang of +the above objects, + +so it's tang of j divided by kt. + +So the point is +that whenever I look + +at the delta in +temperature, I can translate + +that delta in temperature to +a delta int times the value + +of the derivative at +the location of this, + +which is some finite number. + +Of basically up +to some constant, + +taking derivatives with +respect to temperature, + +with respect to k, +with respect to tang k, + +with respect to beta. + +Evaluate it at the +finite temperature, + +which is the location +of the critical point. + +They're all the same up to +proportionality constants, + +and that's why I wrote +"proportionality" there. + +One thing that you +have to make sure-- + +and I spent actually half an +hour this morning checking-- + +is that the signs work out fine. + +So I didn't want to write +an expression for the heat + +capacity that was negative. + +So proportionalities +aside, that's + +the one thing that +I better have, + +is that the sign of the heat +capacity, that is positive. + +So that's the expansion of +the term that corresponds to q + +equals to 0. + +The term that was +proportional to q squared, + +look at what we did in +the above expression + +for the Gaussian model. + +Since it was lower +order, it was already + +proportional to q squared. + +We evaluated it at +exactly t equals to tc. + +So I will put here tc 1 +minus tc squared q squared, + +and then I will +have high orders. + +Now fortunately, we +have a value for tc + +that we can substitute in +a couple of places here. + +You can see that this is, +in fact, twice tc plus 1, + +and tc plus 1 is root 2. + +So this is minus 2 root 2. + +I square that, and +this whole thing + +becomes 8 delta t squared. + +This object here, 1 +minus tc squared-- + +you can see if I put the 2 tc +on the other side-- 1 minus tc + +squared' is the +same thing as 2 tc. + +So I can write the whole thing +here as 2 tc squared q squared. + +And the reason I +do that is, like + +before, there's +an overall factor + +that I can take out +of this parentheses. + +And the answer will +be q squared now + +plus 4 delta t over tc squared. + +It's very similar to +what we had before, + +except that when we had q +squared plus 4 delta t over tc, + +we have q squared plus 4 +delta t over tc squared. + +Now this square was very +important for allowing + +us to go for both +positive and negative, + +but let's see its consequence +on the singularity. + +So now log z of the correct +form divided by n-- the singular + +part-- and we calculate +it just as before. + +First of all, rather than +minus 1/2 I have a plus 1/2. + +I have the same integral, which +in the vicinity of the origin + +is symmetric, so I will +write it as 2 pi qd + +q divided by 4 pi squared. + +And then I have log. + +I will forget about this +factor for consideration + +of singularities 4 +delta t over tc squared. + +And now again, it is +exactly the same structure + +as x dx that I had before. + +So it's the same integral. + +And what you will find is that I +evaluate it as 1/8 pi integral, + +essentially q squared plus +4 delta t over tc squared, + +log of q squared plus 4 +delta t over tc squared + +over e evaluated +between 0 and lambda. + +And the only singularity +comes from the evaluation + +that we have at the origin. + +And so that I will +get a factor of minus. + +So I will get 1/8 pi. + +Actually then, I +substitute this factor. + +The 4 and the 8 will give me 2. + +And then I evaluate the +log of delta t squared, + +so that's another factor of 2. + +So actually, only one +factor of pi survives. + +I will have delta t over tc +squared log of, let's say, + +absolute value of +delta t over tc. + +So the only thing that +changed was that whereas I + +had the linear term sitting +in front of the log, now + +have a quadratic term. + +But now when I take two +derivatives, and now + +we are sure that taking +derivatives does not really + +matter whether I'm doing it with +respect to temperature or delta + +t or any other variable. + +You can see that +the leading behavior + +will come taking two +derivatives out here + +and will be +proportional to the log. + +So I will get minus 1 over +pi log of delta t over tc. + +So that if I were to plug the +heat capacity of the system, + +as a function of, let's +say, this parameter t-- + +which is also something that +stands for temperature-- but t + +goes between, say, 0 and 1. + +It's a hyperbolic tangent. + +There's a location which is this +tc, which is root 2 minus 1. + +And the singular part +of the heat capacity-- + +there will be some other +part of the heat capacity + +that is regular-- but +the singular part we see + +has a [INAUDIBLE] divergence. + +And furthermore, you can +see that the amplitudes-- so + +essentially this +goes approaching + +from different sides of the +transition, A plus or A minus + +log of absolute +value of delta a. + +And the ratio of the +amplitudes, which we have also + +said is universal, +is equal to 1. + +And you had +anticipated that based + +on [? duality ?] [INAUDIBLE]. + +All right, so indeed, there +is a different behavior + +between the two models. + +The exact solution allows +us to go both above + +and below, has this +logarithmic singularity. + +And this expression was +first written down-- well, + +first published Onsager in 1944. + +Even couple of +years before that, + +he had written the expression on +boards of various conferences, + +saying that this is +the answer, but he + +didn't publish the paper. + +The way that he did it is based +on the transfer matrix network, + +as we said. + +Basically, we can +imagine that we + +have a lattice that is, +let's say, I parallel + +in one direction, +l perpendicular + +in the other direction. + +And then for the problems +that you had to do, + +the transform matrix for +one dimensional model, + +we can easy to do it +for a [? ladder ?]. + +It's a 4 by 4. + +For this, it becomes a 2 to +the l by 2 to the l matrix. + +And of course, you are +interested in the limit where + +l goes to infinity so that +you can come 2-dimensional. + +And so he was able to sort +of look at this structure + +of this matrix, recognize that +the elements of this matrix + +could be represented in +terms of other matrices + +that had some +interesting algebra. + +And then he arguably +could figure out + +what the diagonalization looked +like in general for arbitrary + +l, and then calculate +log z in terms + +of the log of the +largest eigenvalue. + +I guess we have to +multiply by l parallel. + +And showed that, indeed, +it corresponds to this + +and has this phase transition. + +And before this solution, +people were not even sure + +that when you sum an expression +such as that for partition + +function if you ever get +a singularity because, + +again, on the face +of it, it's basically + +a sum of exponential functions. + +Each one of them is +perfectly analytic, + +sums of analytical functions. + +It's supposed to be analytical. + +The whole key lies in the limit +of taking, say, l to infinity + +and n to infinity, +and then you'll + +be able to see these +kinds of singularities. + +And then again, +some people thought + +that the only type +of singularities + +that you will be able to +get are the kinds of things + +that we saw [INAUDIBLE] point. + +So to see a different +type of singularity + +with a heat capacity that was +actually divergent and could + +explicitly be shown +through mathematics + +was quite an +interesting revelation. + +So the kind of +relative importance + +of that is that +after the war-- you + +can see this is all around the +time of World War II-- Casimir + +wrote to Pauli saying that I +have been away from thinking + +about physics the past few years +with the war and all of that. + +Anything interesting happening +in theoretical physics? + +And Pauli responded, well, +not much except that Onsager + +solved the +2-dimensionalizing model. + +Of course, the solution that +he has is quite obscure. + +And I don't think many +people understand that. + +Then before, the form that +people refer to was presented + +is actually kind of interesting, +because this paper has + +something about +crystal statistics, + +and then there's the following +paper by a different author-- + +Bruria Kaufman, 1949-- +has this same title + +except it goes from +number two or something. + +So they were clearly +talking to each other, + +but what she was able +to show, Bruria Kaufman, + +was that the structure +of these matrices + +can be simplified +much further and can + +be made to look +like spinners that + +are familiar from other +branches of physics. + +And so this kind +of 50-page paper + +was kind of reduced to +something like a 20-page paper. + +And that's the solution that +is reproduced in Wong's book. + +Chapter 15 of Wong has +essentially a reproduction + +of this. + +I was looking at this +because there aren't really + +that many women +mathematical physicists, + +so I was kind of +looking at her history, + +and she's quite +an unusual person. + +So it turns out +that for a while, + +she was mathematical +assistant to Albert Einstein. + +She was first married to one of +the most well known linguists + +of the 20th century. + +And for a while, they were +both in Israel in a kibbutz + +where this important linguist +was acting as a chauffeur + +and driving people around. + +And then later in life, +she married briefly + +Willis Lamb, of Lamb shift. + +He turned out the term, 1949. + +She had done some calculation +that if Lamb had paid attention + +to, he would have +also potentially won + +a Nobel Prize for +Mossbauer effect, + +but at that time +didn't pay attention + +to it so somebody +else got there first. + +So very interesting person. + +So to my mind, a good +project for somebody + +is to write a biography +for this person. + +It doesn't seem to exist. + +OK, so then both of these are +based on this transfer matrix + +method. + +The method that +I have given you, + +which is the graphical +solution, was first + +presented by Kac +and Ward in 1952. + +And it is reproduced +in Feynman's book. + +So Feynman apparently also +had one of these crucial steps + +of the conjecture with +his factor of minus 1 + +to the power of the +number of crossings, + +giving you the correct +factor to do the counting. + +Now it turns out that I also +did not prove that statement, + +so there is a missing +mathematical link + +to make my proof of this +expression complete. + +And that was provided by a +mathematician called Sherman, + +1960, that essentially +shows very rigorously + +that these factors of minus +1 to the number of crossings + +will work out and magically +make everything happen. + +Now the question to +ask is the following. + +We expect things to +be exactly solvable + +when they are trivial +in some sense. + +Gaussian model is +exactly solvable + +because there is no +interaction among the modes. + +So why is it that the +2-dimensionalizing model + +is solvable? + +And one of the keys to +that is a realization + +of another way of looking +at the problem that + +appeared by Lieb, Mattis, +and Schultz in 1964. + +And so basically what +they said is let's + +take a look at these +pictures that I + +have been drawing +for the graphs. + +And so I have graphs +that basically + +on a kind of coarse level, they +look something like this maybe. + +And what they said was that +if we look at the transfer + +matrix-- the one that +Onsager and Bruria + +Kaufman were looking at. + +And the reason it was +solvable, it looked very much + +like you had a +system of fermions. + +And then the insight is that +if we look at these pictures, + +you can regard this as +a 1-dimensional system + +of fermions that is +evolving in time. + +And what you are looking at +these borderline histories + +of two particles +that are propagating. + +Here they annihilate each other. + +Here they annihilate each other. + +Another pair gets +created, et cetera. + +But in one dimensions, fermions +you can regard two ways-- + +either they cannot occupy the +same site or you can say, well, + +let them occupy in same site, +but then I introduce these + +factors of minus 1 for +the exchange of fermions. + +So when two fermions cross +each other in one dimension, + +their position +has been exchanged + +so you have to put a +minus 1 for crossing. + +And then when you sum over all +histories for every crossing, + +there will be one that +touches and goes away. + +And the sum total of +the two of them is 0. + +So the point is that +at the end of the day, + +this theory is a theory +of three fermions. + +So we have not solved, +in fact, an interacting + +complicated problem. + +It is. + +But in the right +perspective, it looks + +like a bunch of fermions that +completely non-interacting pass + +through each other +as long as we're + +willing to put the minus 1 phase +that you have for crossings. + +One last aspect to +think about that you + +learn from this +fermionic perspective. + +Look at this expression. + +Why did I say that this +is a Gaussian model? + +We saw that we could +get this, z Gaussian, + +by doing an integral +essentially over weights + +that were continuous by i. + +And the weight I could click +here as kij phi i phi j. + +Because in principle, if I +only count an interaction once, + +let's say I count it twice. + +I could put a factor of 1/2 +if I allow i and j to be some. + +Especially I said the weight +that I have to put here + +is something like +phi i squared over 2. + +So this essentially you +can see z of the Gaussian + +ultimately always +becomes something like z + +of the Gaussian is going to +be 1 over the square root + +of a determinant of whatever +the quadratic form is up there. + +And when you take the log +of the partition function, + +the square root of the +determinant becomes minus 1/2 + +of the log of the +determinant, which + +is what we've been calculating. + +So that's obvious. + +You say this object +over here that you + +write as an answer is also +log of some determinant. + +So can I think of these as +some kind of a rock that + +is prescribed according to +these rules on a lattice, + +give weights to jump +according to what I have, + +then do a kind of +Gaussian integration + +and get the same answer? + +Well, the difficulty +is precisely + +this 1/2 versus minus +1/2, because when + +you do the Gaussian +integration, you + +get the determinant +in the denominator. + +So is there a trick to get the +determinant in the numerator? + +And the answer is +that people who + +do have integral formulations +for fermionic systems + +rely on coherent +states that involve + +anti-commuting variables, +called Grassmann variables. + +And the very interesting thing +about Grassmann variables + +is that if I do the analog +of the Gaussian integration, + +the answer-- rather than +being in the determinant, + +in the denominator-- +goes into the numerator. + +And so one can, in fact, +rewrite this partition function, + +sort of working +backward, in terms + +of an integration over +Gaussian distributed + +Grassmannian variables +on the lattice, + +which is also equivalent +to another way of thinking + +about fermions. + +Let's see. + +What else is known +about this model? + +So I said that the specific +heat singularity is known, + +so we have this +alpha which is 0 log. + +Given that the +structure that we have + +involves inside the log +something that is like this, + +you won't be surprised that if I +think in terms of a correlation + +length-- so typically q's +would be an inverse correlation + +length, some kind of a q +at which I will be reaching + +appropriate saturation for +a delta t-- I will arrive + +at a correlation range +that diverge as delta t + +to the minus 1. + +Again, I can write it +more precisely as b plus b + +minus to the minus mu minus. + +The ratio of the b's +this is 1, and the mus + +are the same and equal to 1. + +So the correlation length +diverges with an exponent 1, + +and one can [INAUDIBLE] +this exactly. + +One can then also calculate +actual correlations + +at criticality and show that +that criticality correlations + +decay with separation +between the points + +that you are looking at +as 1 over r to the 1/4. + +So the exponent that we call +mu is 1/4 in 2 dimensions. + +Once you have +correlations, you certainly + +know that you can calculate +the susceptibility + +as an integral of the +correlation function. + +And so it's going to be an +integral b 2r over r to the 1/4 + +that is cut off at the +correlation length. + +So that's going to give me c +to the power of 2 minus 1/4, + +which is 7/4. + +So that's going to diverge as +delta t 2 to the minus gamma. + +Gamma is, again, 7/4. + +So these things-- +correlations-- can + +be calculated like +you saw already + +for the case of +the Gaussian model + +with a appropriate modification. + +That is, I have to +look at walks that + +don't come back and +close on themselves, + +but walks that go from one +point to another point. + +So the same types of techniques +that is described here + +will allow you to get to +all of these other results. + +AUDIENCE: Question? + +PROFESSOR: Yes? + +AUDIENCE: Do people try to +experiment on the builds + +as things that should be +[INAUDIBLE] to the Ising model? + +PROFESSOR: There are by now +many experimental realizations + +of [INAUDIBLE] Ising model +in which these exponents-- + +actually, the next +one that I will + +tell you have been +confirmed very nicely. + +So there are a number of +2-dimensional absorb, systems, + +a number of systems of +mixtures in 2 dimensions + +that phase separate. + +So there's a huge number of +experimental realizations. + +At that time, no, because +we're talking about 70 years. + +So the last thing +that I want to mention + +is, of course, when +you go below tc, + +we expect that-- let's +call it temperate-- + +when I go below temperature, +there will be a magnetization. + +That has always been our +signature of symmetry breaking. + +And so the question is, +what is the magnetization? + +And then this is another +interesting story, + +that around 1950s in a +couple of conferences, + +at the end of somebody's talk, +Onsager went to the board + +and said that he +and Bruria Kaufman + +have found this expression for +the magnetization of the system + +at low temperature as a +function of temperature + +or the coupling constant. + +But they never wrote the +solution down until in 1952, + +actually CN Yang +published a paper + +that has derived this result. + +And since this goes to 1 +at the critical point-- why + +duality [INAUDIBLE] +2k [INAUDIBLE] 2k-- + +[? dual ?] plus 1. + +This vanishes with +an exponent beta, + +which is 1/8, which is the +other exponent in this series. + +So as I said, there +are many people + +who since the '50s and +'60s devoted their life + +to looking at various +generalizations, extensions + +of the Ising model. + +There are many people +who try to solve it + +with a finite in 2 dimensions, +a finite magnetic field. + +You can't do that. + +This magnetization +is obtained only + +at the limit of +[INAUDIBLE] going to 0. + +And clearly, people +have thought a lot + +about doing things in 3 +dimensions or higher dimensions + +without much success. + +So this is basically +the end of the portion + +that I had to give with +discrete models and lattices. + +And as of next lecture, we +will change our perspective + +one more time. + +We'll go back to +the continuum and we + +will look at n component +models in the low temperature + +expansion and see what +happens over there. + +Are there any questions? + +OK, I will give you +a preview of what + +I will be doing in +the next few minutes. + +So we have been looking at these +lattice models in the high t + +limit where expansion +was graphical, + +such as the one that +I have over there. + +But the partition +function turned out + +to be something of +two constants, as 1 + +plus something that involves +loops and things that + +involve multiple +loops, et cetera. + +This was for the Ising model. + +It turns out that if I +go from the Ising model + +to n component space. + +So at each side +of the lattice, I + +put something that +has n components + +subject to the condition +that it's a unit vector. + +And I try to calculate +the partition function + +by integrating over all +of these unit vectors + +in n dimension of a +weight that is just + +a generalization of the Ising, +except that I would have + +the dot product of these things. + +And I start making appropriate +high temperature expansions + +for these models. + +I will generate a +very similar series, + +except that whenever +I see a loop, + +I have to put a +factor of n where + +n is the number of components. + +And this we already +saw when we were + +doing Landau-Ginzburg +expansions. + +We saw that the expansions +that we had over here + +could be graphically +interpreted as representations + +of the various terms that we +had in the Landau-Ginzburg + +expansion. + +And essentially, this factor +of n is the one difficulty. + +You can use the same methods +for numerical expansions + +for all n models that are +these n component models. + +You can't do anything +exactly with them. + +Now the low temperature +expansion for Ising + +like models we saw involved +starting with some ground + +state-- for example, all up-- +and then including excitations + +that were islands of +minus in a sea of plus. + +And so then there higher +order in this series. + +Now for other discrete models, +such as the Potts model, + +you can use the same procedure. + +And again, you see that +in some of the problems + +that you've had to solve. + +But this will not work when we +come to these continuous spin + +markets, because for +continuous spin models, + +the ground state would be when +everybody is pointing in one + +direction, but the excitations +on this ground state + +are not islands that +are flipped over. + +They are these long +wavelength Goldstone modes, + +which we described +earlier in class. + +So if we want to +make an expansion + +to look at the low temperature +[INAUDIBLE] for systems with n + +greater than 1, we have to +make an expansion involving + +Goldstone modes +and, as we will see, + +interactions among +Goldstone modes. + +So you can no longer regard +at that appropriate level + +of sophistication as the +Goldstone modes maintain + +independence from each other. + +And very roughly, the main +difference between discrete + +and these continuous symmetry +models is captured as follows. + +Suppose I have a huge +system that is L by L + +and I impose boundary conditions +on one side where all of this + +spins in one +direction, and ask what + +happens if I impose a different +condition on the other side. + +Well, what would happen is you +would have a domain boundary. + +And the cost of +that domain boundary + +will be proportional to +the area of the boundary + +in d dimensions. + +So the cost is +proportional to some energy + +per bond times L +to the d minus 1. + +Whereas if I try to do the same +thing for a continuous spin + +system, if I align one side like +this, the other side like this, + +but in-between I can gradually +change from one direction + +to another direction. + +And the cost would +be the gradient, + +which is 1 over L +squared times integrated + +over the entire system. + +So the energy cost +of this excitation + +will be some parameter +j, 1 over L-- which + +is the shift-- squared-- which +is the [? strain ?] squared-- + +integrated over +the entire volume, + +so it goes L to the d minus 2. + +So we can see that these +systems are much softer + +than discrete systems. + +For discrete systems, +thermal fluctuations + +are sufficient to destroy +order at low temperature + +as soon as this cost is of the +order of kt, which for large L + +can only happen in d +[INAUDIBLE] 1 and lower. + +Whereas for these systems, it +happens in d of 2 and lower. + +So the lower critical +dimension for these models. + +With continuous symmetry, +we already saw it's 2. + +For these models, it is 1. + +Now we are going to be +interested in this class + +of models. + +I have told you that +in 2 dimensions, + +they should not order. + +So presumably, the critical +temperature-- if I continuously + +regard it as a +function of dimension, + +will go to 0 as a function +of dimension as d minus 2. + +So the insight of +Polyakov was that maybe we + +can look at the interactions +of these old Goldstone modes + +and do a systematic low +temperature expansion that + +reaches the phase transition of +a critical point systematically + +ind minus 2. + +And that's what we will +attempt in the future. \ No newline at end of file diff --git a/6nDqY8MPLDM.txt b/6nDqY8MPLDM.txt new file mode 100644 index 0000000000000000000000000000000000000000..c683f137831977b2dcf2df16fcac275a78c7930e --- /dev/null +++ b/6nDqY8MPLDM.txt @@ -0,0 +1,7363 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license + + align:start position:0% +a Creative Commons license + + + align:start position:0% +a Creative Commons license +your support will help MIT + + align:start position:0% +your support will help MIT + + + align:start position:0% +your support will help MIT +OpenCourseWare continue to offer high + + align:start position:0% +OpenCourseWare continue to offer high + + + align:start position:0% +OpenCourseWare continue to offer high +quality educational resources for free + + align:start position:0% +quality educational resources for free + + + align:start position:0% +quality educational resources for free +to make a donation or view additional + + align:start position:0% +to make a donation or view additional + + + align:start position:0% +to make a donation or view additional +materials from hundreds of MIT courses + + align:start position:0% +materials from hundreds of MIT courses + + + align:start position:0% +materials from hundreds of MIT courses +visit MIT opencourseware at ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +hope everyone had a great Veterans Day + + align:start position:0% +hope everyone had a great Veterans Day + + + align:start position:0% +hope everyone had a great Veterans Day +break yesterday spending it of course as + + align:start position:0% +break yesterday spending it of course as + + + align:start position:0% +break yesterday spending it of course as +I checked my tests on Ian's spending it + + align:start position:0% +I checked my tests on Ian's spending it + + + align:start position:0% +I checked my tests on Ian's spending it +mostly doing your opera research or + + align:start position:0% +mostly doing your opera research or + + + align:start position:0% +mostly doing your opera research or +psets but at least one person got to + + align:start position:0% +psets but at least one person got to + + + align:start position:0% +psets but at least one person got to +watch TV so at least one person got to + + align:start position:0% +watch TV so at least one person got to + + + align:start position:0% +watch TV so at least one person got to +have a real break and that's something + + align:start position:0% +have a real break and that's something + + + align:start position:0% +have a real break and that's something +truly amazing and special so now we're + + align:start position:0% +truly amazing and special so now we're + + + align:start position:0% +truly amazing and special so now we're +going to talk about svms + + align:start position:0% +going to talk about svms + + + align:start position:0% +going to talk about svms +they're pretty much the hardest thing in + + align:start position:0% +they're pretty much the hardest thing in + + + align:start position:0% +they're pretty much the hardest thing in +6:54 however in recent in recent years a + + align:start position:0% +6:54 however in recent in recent years a + + + align:start position:0% +6:54 however in recent in recent years a +few shortcuts have popped up that will + + align:start position:0% +few shortcuts have popped up that will + + + align:start position:0% +few shortcuts have popped up that will +sometimes allow you to solve the + + align:start position:0% +sometimes allow you to solve the + + + align:start position:0% +sometimes allow you to solve the +question depending on what they're + + align:start position:0% +question depending on what they're + + + align:start position:0% +question depending on what they're +asking for without solving some vast + + align:start position:0% +asking for without solving some vast + + + align:start position:0% +asking for without solving some vast +ugly set of equations with the vast + + align:start position:0% +ugly set of equations with the vast + + + align:start position:0% +ugly set of equations with the vast +Uglies number of unknowns so I'm going + + align:start position:0% +Uglies number of unknowns so I'm going + + + align:start position:0% +Uglies number of unknowns so I'm going +to show that to you guys + + align:start position:0% +to show that to you guys + + + align:start position:0% +to show that to you guys +I'm also going to try to explain all the + + align:start position:0% +I'm also going to try to explain all the + + + align:start position:0% +I'm also going to try to explain all the +alphabet soup that's in neural nets and + + align:start position:0% +alphabet soup that's in neural nets and + + + align:start position:0% +alphabet soup that's in neural nets and +what all the letters stand for because I + + align:start position:0% +what all the letters stand for because I + + + align:start position:0% +what all the letters stand for because I +took me a few times going to North go to + + align:start position:0% +took me a few times going to North go to + + + align:start position:0% +took me a few times going to North go to +the S campus it took me a few times + + align:start position:0% +the S campus it took me a few times + + + align:start position:0% +the S campus it took me a few times +going through SVM's to actually find out + + align:start position:0% +going through SVM's to actually find out + + + align:start position:0% +going through SVM's to actually find out +for sure what all those letters stood + + align:start position:0% +for sure what all those letters stood + + + align:start position:0% +for sure what all those letters stood +for and if you guys figure it out first + + align:start position:0% +for and if you guys figure it out first + + + align:start position:0% +for and if you guys figure it out first +try that's going to be great and you + + align:start position:0% +try that's going to be great and you + + + align:start position:0% +try that's going to be great and you +guys will be just fine so let's take a + + align:start position:0% +guys will be just fine so let's take a + + + align:start position:0% +guys will be just fine so let's take a +look at the problem is perhaps most + + align:start position:0% +look at the problem is perhaps most + + + align:start position:0% +look at the problem is perhaps most +optimized for using some of the + + align:start position:0% +optimized for using some of the + + + align:start position:0% +optimized for using some of the +shortcuts to solving it and not putting + + align:start position:0% +shortcuts to solving it and not putting + + + align:start position:0% +shortcuts to solving it and not putting +up all the equations then I will because + + align:start position:0% +up all the equations then I will because + + + align:start position:0% +up all the equations then I will because +I am not because I'm sadistic but + + align:start position:0% +I am not because I'm sadistic but + + + align:start position:0% +I am not because I'm sadistic but +because I'm being nice I will force you + + align:start position:0% +because I'm being nice I will force you + + + align:start position:0% +because I'm being nice I will force you +with me to solve some of the things they + + align:start position:0% +with me to solve some of the things they + + + align:start position:0% +with me to solve some of the things they +didn't ask for us to solve so that you + + align:start position:0% +didn't ask for us to solve so that you + + + align:start position:0% +didn't ask for us to solve so that you +can see that we can't get away with + + align:start position:0% +can see that we can't get away with + + + align:start position:0% +can see that we can't get away with +everything without doing some of the + + align:start position:0% +everything without doing some of the + + + align:start position:0% +everything without doing some of the +harder stuff and + + align:start position:0% +harder stuff and + + + align:start position:0% +harder stuff and +of course definitely ask questions as + + align:start position:0% +of course definitely ask questions as + + + align:start position:0% +of course definitely ask questions as +always but this time even more so you + + align:start position:0% +always but this time even more so you + + + align:start position:0% +always but this time even more so you +guys well if you were looking around you + + align:start position:0% +guys well if you were looking around you + + + align:start position:0% +guys well if you were looking around you +saw nobody in this entire lecture hall + + align:start position:0% +saw nobody in this entire lecture hall + + + align:start position:0% +saw nobody in this entire lecture hall +raise their hand that they're already + + align:start position:0% +raise their hand that they're already + + + align:start position:0% +raise their hand that they're already +set and ready and no svm so if you have + + align:start position:0% +set and ready and no svm so if you have + + + align:start position:0% +set and ready and no svm so if you have +a question maybe everybody else does + + align:start position:0% +a question maybe everybody else does + + + align:start position:0% +a question maybe everybody else does +so let's go + + align:start position:0% +so let's go + + + align:start position:0% +so let's go +you'll start right here as always + + align:start position:0% +you'll start right here as always + + + align:start position:0% +you'll start right here as always +pretend that I can draw and therefore + + align:start position:0% +pretend that I can draw and therefore + + + align:start position:0% +pretend that I can draw and therefore +all the pluses and minuses are only on + + align:start position:0% +all the pluses and minuses are only on + + + align:start position:0% +all the pluses and minuses are only on +integer coordinates so we are asked in + + align:start position:0% +integer coordinates so we are asked in + + + align:start position:0% +integer coordinates so we are asked in +this problem to circle the support + + align:start position:0% +this problem to circle the support + + + align:start position:0% +this problem to circle the support +vectors draw the edges of the street and + + align:start position:0% +vectors draw the edges of the street and + + + align:start position:0% +vectors draw the edges of the street and +then the dotted line in the middle that + + align:start position:0% +then the dotted line in the middle that + + + align:start position:0% +then the dotted line in the middle that +separates them the separator as a dashed + + align:start position:0% +separates them the separator as a dashed + + + align:start position:0% +separates them the separator as a dashed +line and then to give both W and B so + + align:start position:0% +line and then to give both W and B so + + + align:start position:0% +line and then to give both W and B so +what are W and B well there's a few + + align:start position:0% +what are W and B well there's a few + + + align:start position:0% +what are W and B well there's a few +important equations in in svms that we + + align:start position:0% +important equations in in svms that we + + + align:start position:0% +important equations in in svms that we +really hope and I'm going to tell you + + align:start position:0% +really hope and I'm going to tell you + + + align:start position:0% +really hope and I'm going to tell you +we're lucky in this because we don't + + align:start position:0% +we're lucky in this because we don't + + + align:start position:0% +we're lucky in this because we don't +have to but we really hope that we don't + + align:start position:0% +have to but we really hope that we don't + + + align:start position:0% +have to but we really hope that we don't +have to use because they provide a huge + + align:start position:0% +have to use because they provide a huge + + + align:start position:0% +have to use because they provide a huge +number of variables so one of those + + align:start position:0% +number of variables so one of those + + + align:start position:0% +number of variables so one of those +crucial equations is that for a spur a + + align:start position:0% +crucial equations is that for a spur a + + + align:start position:0% +crucial equations is that for a spur a +plus support vector W vector dot X plus + + align:start position:0% +plus support vector W vector dot X plus + + + align:start position:0% +plus support vector W vector dot X plus +the plus support vector plus B equals 1 + + align:start position:0% + + + + align:start position:0% + +WX minus plus B with minus 1 and W dot + + align:start position:0% +WX minus plus B with minus 1 and W dot + + + align:start position:0% +WX minus plus B with minus 1 and W dot +that dotted line I don't know we'll call + + align:start position:0% +that dotted line I don't know we'll call + + + align:start position:0% +that dotted line I don't know we'll call +it dot dot plus B equals 0 so what does + + align:start position:0% +it dot dot plus B equals 0 so what does + + + align:start position:0% +it dot dot plus B equals 0 so what does +this mean there are a lot of vectors + + align:start position:0% +this mean there are a lot of vectors + + + align:start position:0% +this mean there are a lot of vectors +well I mean we're usually in + + align:start position:0% +well I mean we're usually in + + + align:start position:0% +well I mean we're usually in +two-dimensional space so we can + + align:start position:0% +two-dimensional space so we can + + + align:start position:0% +two-dimensional space so we can +basically just say that there's two + + align:start position:0% +basically just say that there's two + + + align:start position:0% +basically just say that there's two +components of this W vector W 1 and W 2 + + align:start position:0% +components of this W vector W 1 and W 2 + + + align:start position:0% +components of this W vector W 1 and W 2 +and they're just two coefficients and a + + align:start position:0% +and they're just two coefficients and a + + + align:start position:0% +and they're just two coefficients and a +linear equation so to get for instance + + align:start position:0% +linear equation so to get for instance + + + align:start position:0% +linear equation so to get for instance +what we're interested in finding this + + align:start position:0% +what we're interested in finding this + + + align:start position:0% +what we're interested in finding this +that dot line we'll just call that X + + align:start position:0% +that dot line we'll just call that X + + + align:start position:0% +that dot line we'll just call that X +with nothing on it actually maybe + + align:start position:0% +with nothing on it actually maybe + + + align:start position:0% +with nothing on it actually maybe +that'll be easier this is equivalent to + + align:start position:0% +that'll be easier this is equivalent to + + + align:start position:0% +that'll be easier this is equivalent to +saying W 1 X 1 plus W 2 X 2 plus B + + align:start position:0% +saying W 1 X 1 plus W 2 X 2 plus B + + + align:start position:0% +saying W 1 X 1 plus W 2 X 2 plus B +equals 0 where X 1 is this and X 2 is + + align:start position:0% +equals 0 where X 1 is this and X 2 is + + + align:start position:0% +equals 0 where X 1 is this and X 2 is +this we would possibly call them x and y + + align:start position:0% +this we would possibly call them x and y + + + align:start position:0% +this we would possibly call them x and y +so one way to think about it is you know + + align:start position:0% +so one way to think about it is you know + + + align:start position:0% +so one way to think about it is you know +W 1 we call a a x+ called W to be B Y oh + + align:start position:0% +W 1 we call a a x+ called W to be B Y oh + + + align:start position:0% +W 1 we call a a x+ called W to be B Y oh +don't call it B + + align:start position:0% +don't call it B + + + align:start position:0% +don't call it B +well a X plus CY plus B equals put this + + align:start position:0% +well a X plus CY plus B equals put this + + + align:start position:0% +well a X plus CY plus B equals put this +on parenthesis this is basically an + + align:start position:0% +on parenthesis this is basically an + + + align:start position:0% +on parenthesis this is basically an +equation like this or you know y equals + + align:start position:0% + + + + align:start position:0% + +negative a over C X minus B over C it's + + align:start position:0% +negative a over C X minus B over C it's + + + align:start position:0% +negative a over C X minus B over C it's +basically y equals MX plus B does + + align:start position:0% +basically y equals MX plus B does + + + align:start position:0% +basically y equals MX plus B does +everyone see that this thing that we're + + align:start position:0% +everyone see that this thing that we're + + + align:start position:0% +everyone see that this thing that we're +looking for this w dot X plus B equals 0 + + align:start position:0% +looking for this w dot X plus B equals 0 + + + align:start position:0% +looking for this w dot X plus B equals 0 +is the equation of a line on in + + align:start position:0% +is the equation of a line on in + + + align:start position:0% +is the equation of a line on in +Cartesian coordinates it just looks + + align:start position:0% +Cartesian coordinates it just looks + + + align:start position:0% +Cartesian coordinates it just looks +uglier normally when we're doing all + + align:start position:0% +uglier normally when we're doing all + + + align:start position:0% +uglier normally when we're doing all +this solving for W and B we'd have to + + align:start position:0% +this solving for W and B we'd have to + + + align:start position:0% +this solving for W and B we'd have to +put in equations with the you tons of + + align:start position:0% +put in equations with the you tons of + + + align:start position:0% +put in equations with the you tons of +equations plug in all the support + + align:start position:0% +equations plug in all the support + + + align:start position:0% +equations plug in all the support +vectors in there and we have to use + + align:start position:0% +vectors in there and we have to use + + + align:start position:0% +vectors in there and we have to use +these little devils called alphas which + + align:start position:0% +these little devils called alphas which + + + align:start position:0% +these little devils called alphas which +alphas essentially if it wasn't clear in + + align:start position:0% +alphas essentially if it wasn't clear in + + + align:start position:0% +alphas essentially if it wasn't clear in +the lecture which it usually isn't + + align:start position:0% +the lecture which it usually isn't + + + align:start position:0% +the lecture which it usually isn't +completely clear to everyone wasn't + + align:start position:0% +completely clear to everyone wasn't + + + align:start position:0% +completely clear to everyone wasn't +clear to me completely alphas way I'd + + align:start position:0% +clear to me completely alphas way I'd + + + align:start position:0% +clear to me completely alphas way I'd +like to think about them the Alpha is in + + align:start position:0% +like to think about them the Alpha is in + + + align:start position:0% +like to think about them the Alpha is in +this problem is they are the weight of + + align:start position:0% +this problem is they are the weight of + + + align:start position:0% +this problem is they are the weight of +how significant any particular point on + + align:start position:0% +how significant any particular point on + + + align:start position:0% +how significant any particular point on +the graph is towards creating the + + align:start position:0% +the graph is towards creating the + + + align:start position:0% +the graph is towards creating the +boundary this the higher the alpha is + + align:start position:0% +boundary this the higher the alpha is + + + align:start position:0% +boundary this the higher the alpha is +the more that that point narrows in the + + align:start position:0% +the more that that point narrows in the + + + align:start position:0% +the more that that point narrows in the +boundary the lower the alpha is the less + + align:start position:0% +boundary the lower the alpha is the less + + + align:start position:0% +boundary the lower the alpha is the less +at that point narrows in the boundary + + align:start position:0% +at that point narrows in the boundary + + + align:start position:0% +at that point narrows in the boundary +the wider the road can be and if that + + align:start position:0% +the wider the road can be and if that + + + align:start position:0% +the wider the road can be and if that +point + + align:start position:0% +point + + + align:start position:0% +point +do anything if that point is irrelevant + + align:start position:0% +do anything if that point is irrelevant + + + align:start position:0% +do anything if that point is irrelevant +and could be removed it wouldn't affect + + align:start position:0% +and could be removed it wouldn't affect + + + align:start position:0% +and could be removed it wouldn't affect +the boundary the Alpha is everyone zero + + align:start position:0% +the boundary the Alpha is everyone zero + + + align:start position:0% +the boundary the Alpha is everyone zero +well that was one person but you can + + align:start position:0% +well that was one person but you can + + + align:start position:0% +well that was one person but you can +suffice for everyone the Alpha is zero + + align:start position:0% +suffice for everyone the Alpha is zero + + + align:start position:0% +suffice for everyone the Alpha is zero +and that means if it's not a support + + align:start position:0% +and that means if it's not a support + + + align:start position:0% +and that means if it's not a support +vector if it's not one of the vectors on + + align:start position:0% +vector if it's not one of the vectors on + + + align:start position:0% +vector if it's not one of the vectors on +the boundary lines it will always have + + align:start position:0% +the boundary lines it will always have + + + align:start position:0% +the boundary lines it will always have +an alpha of zero because it doesn't + + align:start position:0% +an alpha of zero because it doesn't + + + align:start position:0% +an alpha of zero because it doesn't +affect so keeping that in mind there's a + + align:start position:0% +affect so keeping that in mind there's a + + + align:start position:0% +affect so keeping that in mind there's a +few fun and important equations about + + align:start position:0% +few fun and important equations about + + + align:start position:0% +few fun and important equations about +alphas that will mean if we're solving + + align:start position:0% +alphas that will mean if we're solving + + + align:start position:0% +alphas that will mean if we're solving +many equations for many unknowns which + + align:start position:0% +many equations for many unknowns which + + + align:start position:0% +many equations for many unknowns which +hopefully we won't have to do the sum + + align:start position:0% +hopefully we won't have to do the sum + + + align:start position:0% +hopefully we won't have to do the sum +over the positive alphas equals the sum + + align:start position:0% +over the positive alphas equals the sum + + + align:start position:0% +over the positive alphas equals the sum +over and the alphas of the negative + + align:start position:0% +over and the alphas of the negative + + + align:start position:0% +over and the alphas of the negative +points this is true over all the points + + align:start position:0% +points this is true over all the points + + + align:start position:0% +points this is true over all the points +but since all the alphas are 0 except + + align:start position:0% +but since all the alphas are 0 except + + + align:start position:0% +but since all the alphas are 0 except +for the support vectors it also means + + align:start position:0% +for the support vectors it also means + + + align:start position:0% +for the support vectors it also means +the alphas of the positive support + + align:start position:0% +the alphas of the positive support + + + align:start position:0% +the alphas of the positive support +vectors are equal to the alphas of the + + align:start position:0% +vectors are equal to the alphas of the + + + align:start position:0% +vectors are equal to the alphas of the +negative support vectors additionally + + align:start position:0% +negative support vectors additionally + + + align:start position:0% +negative support vectors additionally +our buddy the W vector is equal to the + + align:start position:0% +our buddy the W vector is equal to the + + + align:start position:0% +our buddy the W vector is equal to the +sum over the all I that R plus vectors + + align:start position:0% +sum over the all I that R plus vectors + + + align:start position:0% +sum over the all I that R plus vectors +of WI alpha I minus M over J minus + + align:start position:0% +of WI alpha I minus M over J minus + + + align:start position:0% +of WI alpha I minus M over J minus +vectors of W J alpha J now all these + + align:start position:0% +vectors of W J alpha J now all these + + + align:start position:0% +vectors of W J alpha J now all these +equations can be used in a bloody mess + + align:start position:0% +equations can be used in a bloody mess + + + align:start position:0% +equations can be used in a bloody mess +to figure out the answer to what we're + + align:start position:0% +to figure out the answer to what we're + + + align:start position:0% +to figure out the answer to what we're +trying to find which is circle as well + + align:start position:0% +trying to find which is circle as well + + + align:start position:0% +trying to find which is circle as well +actually they can't be used to circle of + + align:start position:0% +actually they can't be used to circle of + + + align:start position:0% +actually they can't be used to circle of +support vectors and draw the draw the + + align:start position:0% +support vectors and draw the draw the + + + align:start position:0% +support vectors and draw the draw the +dotted line but once we do that all + + align:start position:0% +dotted line but once we do that all + + + align:start position:0% +dotted line but once we do that all +these equations can be used in a bloody + + align:start position:0% +these equations can be used in a bloody + + + align:start position:0% +these equations can be used in a bloody +mess to give us the but the next thing + + align:start position:0% +mess to give us the but the next thing + + + align:start position:0% +mess to give us the but the next thing +that we want which is W and B so + + align:start position:0% +that we want which is W and B so + + + align:start position:0% +that we want which is W and B so +fortunately there's another way to get W + + align:start position:0% +fortunately there's another way to get W + + + align:start position:0% +fortunately there's another way to get W +and B if you guys really want at the at + + align:start position:0% +and B if you guys really want at the at + + + align:start position:0% +and B if you guys really want at the at +the end of the hour we can also try to + + align:start position:0% +the end of the hour we can also try to + + + align:start position:0% +the end of the hour we can also try to +get try to drive W and B using the many + + align:start position:0% +get try to drive W and B using the many + + + align:start position:0% +get try to drive W and B using the many +equations and many unknowns but it's a + + align:start position:0% +equations and many unknowns but it's a + + + align:start position:0% +equations and many unknowns but it's a +bit painful we'll try to do it the cool + + align:start position:0% +bit painful we'll try to do it the cool + + + align:start position:0% +bit painful we'll try to do it the cool +way so let's start + + align:start position:0% +way so let's start + + + align:start position:0% +way so let's start +this is the one we're looking at we need + + align:start position:0% +this is the one we're looking at we need + + + align:start position:0% +this is the one we're looking at we need +to find what the support vectors are so + + align:start position:0% +to find what the support vectors are so + + + align:start position:0% +to find what the support vectors are so +first thing we need to do is simply I it + + align:start position:0% +first thing we need to do is simply I it + + + align:start position:0% +first thing we need to do is simply I it +fortunately on the test there will + + align:start position:0% +fortunately on the test there will + + + align:start position:0% +fortunately on the test there will +always be ones that you can I if you're + + align:start position:0% +always be ones that you can I if you're + + + align:start position:0% +always be ones that you can I if you're +supposed to circle the support vectors + + align:start position:0% +supposed to circle the support vectors + + + align:start position:0% +supposed to circle the support vectors +there's obviously some number of pluses + + align:start position:0% +there's obviously some number of pluses + + + align:start position:0% +there's obviously some number of pluses +and some number of minuses I say + + align:start position:0% +and some number of minuses I say + + + align:start position:0% +and some number of minuses I say +obviously but maybe not but hopefully + + align:start position:0% +obviously but maybe not but hopefully + + + align:start position:0% +obviously but maybe not but hopefully +obviously and we'll find out because I'm + + align:start position:0% +obviously and we'll find out because I'm + + + align:start position:0% +obviously and we'll find out because I'm +going to call them random people so give + + align:start position:0% +going to call them random people so give + + + align:start position:0% +going to call them random people so give +me a positive support vector yeah + + align:start position:0% +me a positive support vector yeah + + + align:start position:0% +me a positive support vector yeah +perfect that's good all right that's + + align:start position:0% +perfect that's good all right that's + + + align:start position:0% +perfect that's good all right that's +what ah not give me a native support Oh + + align:start position:0% + + + + align:start position:0% + +No ah that is a good question + + align:start position:0% +No ah that is a good question + + + align:start position:0% +No ah that is a good question +question is what is a support vector how + + align:start position:0% +question is what is a support vector how + + + align:start position:0% +question is what is a support vector how +many other people are will meant to + + align:start position:0% +many other people are will meant to + + + align:start position:0% +many other people are will meant to +having this question see you're not + + align:start position:0% +having this question see you're not + + + align:start position:0% +having this question see you're not +alone okay before I go on I'm going to + + align:start position:0% +alone okay before I go on I'm going to + + + align:start position:0% +alone okay before I go on I'm going to +assume guys make sure I'm correct money + + align:start position:0% +assume guys make sure I'm correct money + + + align:start position:0% +assume guys make sure I'm correct money +was uh just being served so I can tailor + + align:start position:0% +was uh just being served so I can tailor + + + align:start position:0% +was uh just being served so I can tailor +based on this Monday was the support + + align:start position:0% +based on this Monday was the support + + + align:start position:0% +based on this Monday was the support +vector machine lecture but it was also + + align:start position:0% +vector machine lecture but it was also + + + align:start position:0% +vector machine lecture but it was also +very difficult to follow that's what I + + align:start position:0% +very difficult to follow that's what I + + + align:start position:0% +very difficult to follow that's what I +that's what I usually expect so um what + + align:start position:0% +that's what I usually expect so um what + + + align:start position:0% +that's what I usually expect so um what +is a support vector well all these + + align:start position:0% +is a support vector well all these + + + align:start position:0% +is a support vector well all these +pluses and minuses if we were if we were + + align:start position:0% +pluses and minuses if we were if we were + + + align:start position:0% +pluses and minuses if we were if we were +me and we if I guess yeah if we were me + + align:start position:0% +me and we if I guess yeah if we were me + + + align:start position:0% +me and we if I guess yeah if we were me +and I was describing this problem the + + align:start position:0% +and I was describing this problem the + + + align:start position:0% +and I was describing this problem the +one that we work out in class I would + + align:start position:0% +one that we work out in class I would + + + align:start position:0% +one that we work out in class I would +call them points because they're on the + + align:start position:0% +call them points because they're on the + + + align:start position:0% +call them points because they're on the +graph their points their data points I + + align:start position:0% +graph their points their data points I + + + align:start position:0% +graph their points their data points I +would cut but however in more difficult + + align:start position:0% +would cut but however in more difficult + + + align:start position:0% +would cut but however in more difficult +versions of this problem that have n + + align:start position:0% +versions of this problem that have n + + + align:start position:0% +versions of this problem that have n +dimensions where n is some ridiculous + + align:start position:0% +dimensions where n is some ridiculous + + + align:start position:0% +dimensions where n is some ridiculous +number of dimension + + align:start position:0% +number of dimension + + + align:start position:0% +number of dimension +that you're never going to graph like + + align:start position:0% +that you're never going to graph like + + + align:start position:0% +that you're never going to graph like +say you know some of the research I'm + + align:start position:0% +say you know some of the research I'm + + + align:start position:0% +say you know some of the research I'm +doing now I could use support vector + + align:start position:0% +doing now I could use support vector + + + align:start position:0% +doing now I could use support vector +machines on some of these articles that + + align:start position:0% +machines on some of these articles that + + + align:start position:0% +machines on some of these articles that +I'm reading about cyber events to try to + + align:start position:0% +I'm reading about cyber events to try to + + + align:start position:0% +I'm reading about cyber events to try to +figure out if there's a real event or if + + align:start position:0% +figure out if there's a real event or if + + + align:start position:0% +figure out if there's a real event or if +it's just someone complaining about how + + align:start position:0% +it's just someone complaining about how + + + align:start position:0% +it's just someone complaining about how +we're really vulnerable or something + + align:start position:0% +we're really vulnerable or something + + + align:start position:0% +we're really vulnerable or something +like that and no event actually happened + + align:start position:0% +like that and no event actually happened + + + align:start position:0% +like that and no event actually happened +so the reason why they call these guys + + align:start position:0% +so the reason why they call these guys + + + align:start position:0% +so the reason why they call these guys +vectors is when you're not able to graph + + align:start position:0% +vectors is when you're not able to graph + + + align:start position:0% +vectors is when you're not able to graph +them on a Cartesian plane there's still + + align:start position:0% +them on a Cartesian plane there's still + + + align:start position:0% +them on a Cartesian plane there's still +this long you know vector of many + + align:start position:0% +this long you know vector of many + + + align:start position:0% +this long you know vector of many +different dimensions right now though + + align:start position:0% +different dimensions right now though + + + align:start position:0% +different dimensions right now though +these points represent the vectors it's + + align:start position:0% +these points represent the vectors it's + + + align:start position:0% +these points represent the vectors it's +very simple it's easier to view them + + align:start position:0% +very simple it's easier to view them + + + align:start position:0% +very simple it's easier to view them +this way but for instance that plus at + + align:start position:0% +this way but for instance that plus at + + + align:start position:0% +this way but for instance that plus at +negative 1/2 represents the fact that + + align:start position:0% +negative 1/2 represents the fact that + + + align:start position:0% +negative 1/2 represents the fact that +there's a vector going in the direction + + align:start position:0% +there's a vector going in the direction + + + align:start position:0% +there's a vector going in the direction +of negative 1/2 with the magnitudes such + + align:start position:0% +of negative 1/2 with the magnitudes such + + + align:start position:0% +of negative 1/2 with the magnitudes such +that it reaches negative 1/2 so all + + align:start position:0% +that it reaches negative 1/2 so all + + + align:start position:0% +that it reaches negative 1/2 so all +these points are just a point + + align:start position:0% +these points are just a point + + + align:start position:0% +these points are just a point +representation in vector you probably in + + align:start position:0% +representation in vector you probably in + + + align:start position:0% +representation in vector you probably in +any class that worked with vectors saw + + align:start position:0% +any class that worked with vectors saw + + + align:start position:0% +any class that worked with vectors saw +this saw vectors being represented as + + align:start position:0% +this saw vectors being represented as + + + align:start position:0% +this saw vectors being represented as +points question hi the question is all + + align:start position:0% +points question hi the question is all + + + align:start position:0% +points question hi the question is all +respect to the origin answers + + align:start position:0% +respect to the origin answers + + + align:start position:0% +respect to the origin answers +economically when directions are + + align:start position:0% +economically when directions are + + + align:start position:0% +economically when directions are +represented at points yes it's always + + align:start position:0% +represented at points yes it's always + + + align:start position:0% +represented at points yes it's always +good respect to the origin so that's the + + align:start position:0% +good respect to the origin so that's the + + + align:start position:0% +good respect to the origin so that's the +basic idea is that all these points are + + align:start position:0% +basic idea is that all these points are + + + align:start position:0% +basic idea is that all these points are +vectors so what are support vectors well + + align:start position:0% +vectors so what are support vectors well + + + align:start position:0% +vectors so what are support vectors well +we could call them support points for + + align:start position:0% +we could call them support points for + + + align:start position:0% +we could call them support points for +this case but the reason we call the + + align:start position:0% +this case but the reason we call the + + + align:start position:0% +this case but the reason we call the +support vectors is again in the + + align:start position:0% +support vectors is again in the + + + align:start position:0% +support vectors is again in the +generalized case that you might be doing + + align:start position:0% +generalized case that you might be doing + + + align:start position:0% +generalized case that you might be doing +in the real world with real AI you're + + align:start position:0% +in the real world with real AI you're + + + align:start position:0% +in the real world with real AI you're +going to have the giant vector it's not + + align:start position:0% +going to have the giant vector it's not + + + align:start position:0% +going to have the giant vector it's not +just going to be points on a graph well + + align:start position:0% +just going to be points on a graph well + + + align:start position:0% +just going to be points on a graph well +usually so the support vectors the + + align:start position:0% +usually so the support vectors the + + + align:start position:0% +usually so the support vectors the +support points we found one of them + + align:start position:0% +support points we found one of them + + + align:start position:0% +support points we found one of them +correctly + + align:start position:0% +correctly + + + align:start position:0% +correctly +it's this guy they're going to be the + + align:start position:0% +it's this guy they're going to be the + + + align:start position:0% +it's this guy they're going to be the +ones that again they don't have an alpha + + align:start position:0% +ones that again they don't have an alpha + + + align:start position:0% +ones that again they don't have an alpha +of 0 they're the ones that bind in the + + align:start position:0% +of 0 they're the ones that bind in the + + + align:start position:0% +of 0 they're the ones that bind in the +as petracles of the road the boundary + + align:start position:0% +as petracles of the road the boundary + + + align:start position:0% +as petracles of the road the boundary +lines they're going to be on the edge of + + align:start position:0% +lines they're going to be on the edge of + + + align:start position:0% +lines they're going to be on the edge of +plus whichever direction we draw it this + + align:start position:0% +plus whichever direction we draw it this + + + align:start position:0% +plus whichever direction we draw it this +plus is the edge of the plus region if + + align:start position:0% +plus is the edge of the plus region if + + + align:start position:0% +plus is the edge of the plus region if +we made this the edge of the plus region + + align:start position:0% +we made this the edge of the plus region + + + align:start position:0% +we made this the edge of the plus region +and everything on this side is plus + + align:start position:0% +and everything on this side is plus + + + align:start position:0% +and everything on this side is plus +everything on this size - we'd be + + align:start position:0% +everything on this size - we'd be + + + align:start position:0% +everything on this size - we'd be +screwed because there's two pluses on + + align:start position:0% +screwed because there's two pluses on + + + align:start position:0% +screwed because there's two pluses on +the on the other side of that generally + + align:start position:0% +the on the other side of that generally + + + align:start position:0% +the on the other side of that generally +when trying to find + + align:start position:0% +when trying to find + + + align:start position:0% +when trying to find +support vectors you do something a + + align:start position:0% +support vectors you do something a + + + align:start position:0% +support vectors you do something a +little bit similar to my crazy method of + + align:start position:0% +little bit similar to my crazy method of + + + align:start position:0% +little bit similar to my crazy method of +doing nearest neighbors and try to find + + align:start position:0% +doing nearest neighbors and try to find + + + align:start position:0% +doing nearest neighbors and try to find +a plus my excuse me a plus minus pair + + align:start position:0% +a plus my excuse me a plus minus pair + + + align:start position:0% +a plus my excuse me a plus minus pair +that's close to each other sometimes + + align:start position:0% +that's close to each other sometimes + + + align:start position:0% +that's close to each other sometimes +though it's not just two points because + + align:start position:0% +though it's not just two points because + + + align:start position:0% +though it's not just two points because +sometimes if you try to draw the + + align:start position:0% +sometimes if you try to draw the + + + align:start position:0% +sometimes if you try to draw the +simple-minded thing which is sort of the + + align:start position:0% +simple-minded thing which is sort of the + + + align:start position:0% +simple-minded thing which is sort of the +perpendicular bisector of the two points + + align:start position:0% +perpendicular bisector of the two points + + + align:start position:0% +perpendicular bisector of the two points +you get screwed because there's another + + align:start position:0% +you get screwed because there's another + + + align:start position:0% +you get screwed because there's another +point in your way so now that I've given + + align:start position:0% +point in your way so now that I've given + + + align:start position:0% +point in your way so now that I've given +away a clue let's go + + align:start position:0% +away a clue let's go + + + align:start position:0% +away a clue let's go +and hopefully that made sense to you + + align:start position:0% +and hopefully that made sense to you + + + align:start position:0% +and hopefully that made sense to you +guys the support vectors are the ones on + + align:start position:0% +guys the support vectors are the ones on + + + align:start position:0% +guys the support vectors are the ones on +the edges they're just barely a plus for + + align:start position:0% +the edges they're just barely a plus for + + + align:start position:0% +the edges they're just barely a plus for +sure but barely - for sure let's go back + + align:start position:0% +sure but barely - for sure let's go back + + + align:start position:0% +sure but barely - for sure let's go back +can you give me a negative support + + align:start position:0% +can you give me a negative support + + + align:start position:0% +can you give me a negative support +vector the one on Paulo yeah and does + + align:start position:0% +vector the one on Paulo yeah and does + + + align:start position:0% +vector the one on Paulo yeah and does +anyone think that there's a third + + align:start position:0% +anyone think that there's a third + + + align:start position:0% +anyone think that there's a third +support vector well let's simple-minded + + align:start position:0% +support vector well let's simple-minded + + + align:start position:0% +support vector well let's simple-minded +Lee try the thing that remember support + + align:start position:0% +Lee try the thing that remember support + + + align:start position:0% +Lee try the thing that remember support +vectors always attempt to have the + + align:start position:0% +vectors always attempt to have the + + + align:start position:0% +vectors always attempt to have the +widest possible space between the pluses + + align:start position:0% +widest possible space between the pluses + + + align:start position:0% +widest possible space between the pluses +and the minuses that they can so let's + + align:start position:0% +and the minuses that they can so let's + + + align:start position:0% +and the minuses that they can so let's +simple-minded Lee try to do the + + align:start position:0% +simple-minded Lee try to do the + + + align:start position:0% +simple-minded Lee try to do the +perpendicular bisector and see if it see + + align:start position:0% +perpendicular bisector and see if it see + + + align:start position:0% +perpendicular bisector and see if it see +if it screws us over so when we + + align:start position:0% +if it screws us over so when we + + + align:start position:0% +if it screws us over so when we +simple-minded Lee do the perpendicular + + align:start position:0% +simple-minded Lee do the perpendicular + + + align:start position:0% +simple-minded Lee do the perpendicular +bisector it goes through like here like + + align:start position:0% +bisector it goes through like here like + + + align:start position:0% +bisector it goes through like here like +this and it's just fine so these are the + + align:start position:0% +this and it's just fine so these are the + + + align:start position:0% +this and it's just fine so these are the +only two support vectors + + align:start position:0% + + + + align:start position:0% + +and there's our divider line so we're on + + align:start position:0% +and there's our divider line so we're on + + + align:start position:0% +and there's our divider line so we're on +the homestretch but we have to find W + + align:start position:0% +the homestretch but we have to find W + + + align:start position:0% +the homestretch but we have to find W +and B in olden days we would find W and + + align:start position:0% +and B in olden days we would find W and + + + align:start position:0% +and B in olden days we would find W and +B by plugging in W dot the plus support + + align:start position:0% +B by plugging in W dot the plus support + + + align:start position:0% +B by plugging in W dot the plus support +vector plus B equals one that's very + + align:start position:0% +vector plus B equals one that's very + + + align:start position:0% +vector plus B equals one that's very +crucial these W dot X plus X minus our + + align:start position:0% +crucial these W dot X plus X minus our + + + align:start position:0% +crucial these W dot X plus X minus our +only true equaling one or negative one + + align:start position:0% +only true equaling one or negative one + + + align:start position:0% +only true equaling one or negative one +are only true for support vectors it's + + align:start position:0% +are only true for support vectors it's + + + align:start position:0% +are only true for support vectors it's +always true that W dot any positive + + align:start position:0% +always true that W dot any positive + + + align:start position:0% +always true that W dot any positive +point plus B will be some positive + + align:start position:0% +point plus B will be some positive + + + align:start position:0% +point plus B will be some positive +number but it won't always be supportive + + align:start position:0% +number but it won't always be supportive + + + align:start position:0% +number but it won't always be supportive +it don't won't always be one in fact it + + align:start position:0% +it don't won't always be one in fact it + + + align:start position:0% +it don't won't always be one in fact it +will always be the greater than one up + + align:start position:0% +will always be the greater than one up + + + align:start position:0% +will always be the greater than one up +over here it will always be less than + + align:start position:0% +over here it will always be less than + + + align:start position:0% +over here it will always be less than +negative one down over there + + align:start position:0% +negative one down over there + + + align:start position:0% +negative one down over there +so in olden days we would plug in + + align:start position:0% +so in olden days we would plug in + + + align:start position:0% +so in olden days we would plug in +negative 1/2 into this equation we plug + + align:start position:0% +negative 1/2 into this equation we plug + + + align:start position:0% +negative 1/2 into this equation we plug +in 3 negative 2 into this equation we + + align:start position:0% +in 3 negative 2 into this equation we + + + align:start position:0% +in 3 negative 2 into this equation we +plug in alpha plus equals alpha minus + + align:start position:0% +plug in alpha plus equals alpha minus + + + align:start position:0% +plug in alpha plus equals alpha minus +it's the sums and since there's only one + + align:start position:0% +it's the sums and since there's only one + + + align:start position:0% +it's the sums and since there's only one +plus or minus we know that they were + + align:start position:0% +plus or minus we know that they were + + + align:start position:0% +plus or minus we know that they were +equal and then we fidget around with + + align:start position:0% +equal and then we fidget around with + + + align:start position:0% +equal and then we fidget around with +this W equation however there is a + + align:start position:0% +this W equation however there is a + + + align:start position:0% +this W equation however there is a +better way to do it and so let's use + + align:start position:0% +better way to do it and so let's use + + + align:start position:0% +better way to do it and so let's use +this cheap strategy to solve to solve + + align:start position:0% +this cheap strategy to solve to solve + + + align:start position:0% +this cheap strategy to solve to solve +this version of the SVM here's how first + + align:start position:0% +this version of the SVM here's how first + + + align:start position:0% +this version of the SVM here's how first +and I know I didn't draw these + + align:start position:0% +and I know I didn't draw these + + + align:start position:0% +and I know I didn't draw these +completely straight sorry but can anyone + + align:start position:0% +completely straight sorry but can anyone + + + align:start position:0% +completely straight sorry but can anyone +by looking at the fact that this is 3 + + align:start position:0% +by looking at the fact that this is 3 + + + align:start position:0% +by looking at the fact that this is 3 +negative 2 and this is negative 1/2 can + + align:start position:0% +negative 2 and this is negative 1/2 can + + + align:start position:0% +negative 2 and this is negative 1/2 can +anyone tell me what the equation uh if + + align:start position:0% +anyone tell me what the equation uh if + + + align:start position:0% +anyone tell me what the equation uh if +you can do y equals MX plus B can anyone + + align:start position:0% +you can do y equals MX plus B can anyone + + + align:start position:0% +you can do y equals MX plus B can anyone +tell me what the equation of that dotted + + align:start position:0% +tell me what the equation of that dotted + + + align:start position:0% +tell me what the equation of that dotted +line is supposed to be if I was a good + + align:start position:0% +line is supposed to be if I was a good + + + align:start position:0% +line is supposed to be if I was a good +at drawing you said Y minus 1 and I say + + align:start position:0% +at drawing you said Y minus 1 and I say + + + align:start position:0% +at drawing you said Y minus 1 and I say +yes why I'm just - why so therefore the + + align:start position:0% +yes why I'm just - why so therefore the + + + align:start position:0% +yes why I'm just - why so therefore the +pluses would be y is greater than or + + align:start position:0% +pluses would be y is greater than or + + + align:start position:0% +pluses would be y is greater than or +equal to X minus X minus 1 + + align:start position:0% +equal to X minus X minus 1 + + + align:start position:0% +equal to X minus X minus 1 +indeed so we've already seen that WX + + align:start position:0% +indeed so we've already seen that WX + + + align:start position:0% +indeed so we've already seen that WX +plus B like somehow can be converted + + align:start position:0% +plus B like somehow can be converted + + + align:start position:0% +plus B like somehow can be converted +into this form right so therefore if we + + align:start position:0% +into this form right so therefore if we + + + align:start position:0% +into this form right so therefore if we +have y equals X minus 1 then we know + + align:start position:0% +have y equals X minus 1 then we know + + + align:start position:0% +have y equals X minus 1 then we know +that + + align:start position:0% +that + + + align:start position:0% +that +we have in w1 that we know that we have + + align:start position:0% +we have in w1 that we know that we have + + + align:start position:0% +we have in w1 that we know that we have +W X plus B equals zero let's do that + + align:start position:0% +W X plus B equals zero let's do that + + + align:start position:0% +W X plus B equals zero let's do that +here so we know that W 1 W 1 X 1 being + + align:start position:0% +here so we know that W 1 W 1 X 1 being + + + align:start position:0% +here so we know that W 1 W 1 X 1 being +even call it X and why I think it'll be + + align:start position:0% +even call it X and why I think it'll be + + + align:start position:0% +even call it X and why I think it'll be +fine no one will come after us + + align:start position:0% +fine no one will come after us + + + align:start position:0% +fine no one will come after us +w 2 y plus B equals 0 but we also know + + align:start position:0% +w 2 y plus B equals 0 but we also know + + + align:start position:0% +w 2 y plus B equals 0 but we also know +that y equals x minus 1 which means that + + align:start position:0% + + + + align:start position:0% + +if y equals X minus 1 then that means + + align:start position:0% +if y equals X minus 1 then that means + + + align:start position:0% +if y equals X minus 1 then that means +that according to this thing that we + + align:start position:0% +that according to this thing that we + + + align:start position:0% +that according to this thing that we +have over here then negative w1 over w2 + + align:start position:0% +have over here then negative w1 over w2 + + + align:start position:0% +have over here then negative w1 over w2 +equals so we know that negative w1 over + + align:start position:0% +equals so we know that negative w1 over + + + align:start position:0% +equals so we know that negative w1 over +w2 and we have negative negative B over + + align:start position:0% +w2 and we have negative negative B over + + + align:start position:0% +w2 and we have negative negative B over +w2 so y equals x minus 1 and if we solve + + align:start position:0% +w2 so y equals x minus 1 and if we solve + + + align:start position:0% +w2 so y equals x minus 1 and if we solve +this equation to make it look like this + + align:start position:0% +this equation to make it look like this + + + align:start position:0% +this equation to make it look like this +we would have y equals negative w1 over + + align:start position:0% +we would have y equals negative w1 over + + + align:start position:0% +we would have y equals negative w1 over +w2 minus B over w2 so we know that in + + align:start position:0% +w2 minus B over w2 so we know that in + + + align:start position:0% +w2 minus B over w2 so we know that in +some way shape or form that we know that + + align:start position:0% +some way shape or form that we know that + + + align:start position:0% +some way shape or form that we know that +Nick did then therefore w1 over w2 is + + align:start position:0% +Nick did then therefore w1 over w2 is + + + align:start position:0% +Nick did then therefore w1 over w2 is +some scalar multiple of minus 1 and we + + align:start position:0% +some scalar multiple of minus 1 and we + + + align:start position:0% +some scalar multiple of minus 1 and we +know that B over w2 is in fact some + + align:start position:0% +know that B over w2 is in fact some + + + align:start position:0% +know that B over w2 is in fact some +scalar multiple of positive one scalar + + align:start position:0% +scalar multiple of positive one scalar + + + align:start position:0% +scalar multiple of positive one scalar +multiple scalar multiple well why is it + + align:start position:0% +multiple scalar multiple well why is it + + + align:start position:0% +multiple scalar multiple well why is it +a scalar multiple why is it it just + + align:start position:0% +a scalar multiple why is it it just + + + align:start position:0% +a scalar multiple why is it it just +going to be negative 1 or positive 1 + + align:start position:0% +going to be negative 1 or positive 1 + + + align:start position:0% +going to be negative 1 or positive 1 +because just because in this equation we + + align:start position:0% +because just because in this equation we + + + align:start position:0% +because just because in this equation we +can multiply the entire equation by any + + align:start position:0% +can multiply the entire equation by any + + + align:start position:0% +can multiply the entire equation by any +number and it will still have the same + + align:start position:0% +number and it will still have the same + + + align:start position:0% +number and it will still have the same +boundary line you guys see that if you + + align:start position:0% +boundary line you guys see that if you + + + align:start position:0% +boundary line you guys see that if you +know if X here if we multiplied + + align:start position:0% +know if X here if we multiplied + + + align:start position:0% +know if X here if we multiplied +everything since it's all divided by + + align:start position:0% +everything since it's all divided by + + + align:start position:0% +everything since it's all divided by +- if we double w - but also w BB and w1 + + align:start position:0% +- if we double w - but also w BB and w1 + + + align:start position:0% +- if we double w - but also w BB and w1 +it would be the exact same question do + + align:start position:0% +it would be the exact same question do + + + align:start position:0% +it would be the exact same question do +you guys agree so there's in fact the + + align:start position:0% +you guys agree so there's in fact the + + + align:start position:0% +you guys agree so there's in fact the +infinitely many possible equations you + + align:start position:0% +infinitely many possible equations you + + + align:start position:0% +infinitely many possible equations you +say well great mark you figured out what + + align:start position:0% +say well great mark you figured out what + + + align:start position:0% +say well great mark you figured out what +form it is so you figured out that w1 + + align:start position:0% +form it is so you figured out that w1 + + + align:start position:0% +form it is so you figured out that w1 +over w2 equals on some scalar multiple + + align:start position:0% +over w2 equals on some scalar multiple + + + align:start position:0% +over w2 equals on some scalar multiple +of negative one so it's negative one + + align:start position:0% +of negative one so it's negative one + + + align:start position:0% +of negative one so it's negative one +times what's everyone's favorite letter + + align:start position:0% +times what's everyone's favorite letter + + + align:start position:0% +times what's everyone's favorite letter +okay + + align:start position:0% +okay + + + align:start position:0% +okay +negative 1 times K and we figured out + + align:start position:0% +negative 1 times K and we figured out + + + align:start position:0% +negative 1 times K and we figured out +that B over w2 is I guess we can just do + + align:start position:0% +that B over w2 is I guess we can just do + + + align:start position:0% +that B over w2 is I guess we can just do +negative K is positive K but what's K + + align:start position:0% +negative K is positive K but what's K + + + align:start position:0% +negative K is positive K but what's K +how are we going to figure it out well + + align:start position:0% +how are we going to figure it out well + + + align:start position:0% +how are we going to figure it out well +it's a good question I will tell you how + + align:start position:0% + + + + align:start position:0% + +I'll assert the following fact as true + + align:start position:0% +I'll assert the following fact as true + + + align:start position:0% +I'll assert the following fact as true +without proof then I will not prove it + + align:start position:0% + + + + align:start position:0% + +1 over the magnitude of W which is this + + align:start position:0% +1 over the magnitude of W which is this + + + align:start position:0% +1 over the magnitude of W which is this +vector here duck with w1 w2 equals this + + align:start position:0% + + + + align:start position:0% + +where this is that line that I just drew + + align:start position:0% +where this is that line that I just drew + + + align:start position:0% +where this is that line that I just drew +the line from here to this point 1 over + + align:start position:0% +the line from here to this point 1 over + + + align:start position:0% +the line from here to this point 1 over +the magnitude of W equals this therefore + + align:start position:0% +the magnitude of W equals this therefore + + + align:start position:0% +the magnitude of W equals this therefore +since 1 over the magnitude of W equals + + align:start position:0% +since 1 over the magnitude of W equals + + + align:start position:0% +since 1 over the magnitude of W equals +this and this equals I believe 2 root 2 + + align:start position:0% +this and this equals I believe 2 root 2 + + + align:start position:0% +this and this equals I believe 2 root 2 +because we're going over to down to + + align:start position:0% +because we're going over to down to + + + align:start position:0% +because we're going over to down to +Pythagorean theorem 2 or 2 so therefore + + align:start position:0% +Pythagorean theorem 2 or 2 so therefore + + + align:start position:0% +Pythagorean theorem 2 or 2 so therefore +flip everything over magnitude of W + + align:start position:0% +flip everything over magnitude of W + + + align:start position:0% +flip everything over magnitude of W +equals 1 over 2 root 2 so therefore + + align:start position:0% +equals 1 over 2 root 2 so therefore + + + align:start position:0% +equals 1 over 2 root 2 so therefore +magnitude of W equals root 2 over 4 but + + align:start position:0% +magnitude of W equals root 2 over 4 but + + + align:start position:0% +magnitude of W equals root 2 over 4 but +why are we okay well how do we calculate + + align:start position:0% +why are we okay well how do we calculate + + + align:start position:0% +why are we okay well how do we calculate +the magnitude of W do people know in + + align:start position:0% +the magnitude of W do people know in + + + align:start position:0% +the magnitude of W do people know in +general magnitudes of vectors generally + + align:start position:0% +general magnitudes of vectors generally + + + align:start position:0% +general magnitudes of vectors generally +for these vectors we do it by thing the + + align:start position:0% +for these vectors we do it by thing the + + + align:start position:0% +for these vectors we do it by thing the +square root + + align:start position:0% +square root + + + align:start position:0% +square root +of the sum of the components squared so + + align:start position:0% +of the sum of the components squared so + + + align:start position:0% +of the sum of the components squared so +the square root of W 1 squared plus W 2 + + align:start position:0% +the square root of W 1 squared plus W 2 + + + align:start position:0% +the square root of W 1 squared plus W 2 +squared equals root 2 over 4 but that's + + align:start position:0% +squared equals root 2 over 4 but that's + + + align:start position:0% +squared equals root 2 over 4 but that's +not all that's not all we say because we + + align:start position:0% +not all that's not all we say because we + + + align:start position:0% +not all that's not all we say because we +know from this over here that the ratio + + align:start position:0% +know from this over here that the ratio + + + align:start position:0% +know from this over here that the ratio +of W 1 and W 2 is yeah the ratio of the + + align:start position:0% +of W 1 and W 2 is yeah the ratio of the + + + align:start position:0% +of W 1 and W 2 is yeah the ratio of the +ratio of W 1 and W 2 is going to be + + align:start position:0% +ratio of W 1 and W 2 is going to be + + + align:start position:0% +ratio of W 1 and W 2 is going to be +actually sorry I shouldn't put a K here + + align:start position:0% +actually sorry I shouldn't put a K here + + + align:start position:0% +actually sorry I shouldn't put a K here +I realize I probably should have been + + align:start position:0% +I realize I probably should have been + + + align:start position:0% +I realize I probably should have been +confusing you guys a lot w1 over w2 is + + align:start position:0% +confusing you guys a lot w1 over w2 is + + + align:start position:0% +confusing you guys a lot w1 over w2 is +just negative 1 B over w2 is just 1 + + align:start position:0% +just negative 1 B over w2 is just 1 + + + align:start position:0% +just negative 1 B over w2 is just 1 +that's just the fact there's no K the K + + align:start position:0% +that's just the fact there's no K the K + + + align:start position:0% +that's just the fact there's no K the K +is to determine what W 1 and W 2 is w1 + + align:start position:0% +is to determine what W 1 and W 2 is w1 + + + align:start position:0% +is to determine what W 1 and W 2 is w1 +and w2 are so W 1 equals like negative K + + align:start position:0% +and w2 are so W 1 equals like negative K + + + align:start position:0% +and w2 are so W 1 equals like negative K +and W 2 equals positive K and then B + + align:start position:0% +and W 2 equals positive K and then B + + + align:start position:0% +and W 2 equals positive K and then B +equals also positive pay by the way + + align:start position:0% +equals also positive pay by the way + + + align:start position:0% +equals also positive pay by the way +here's a question for you could I have + + align:start position:0% +here's a question for you could I have + + + align:start position:0% +here's a question for you could I have +put the K the negative sign on a + + align:start position:0% +put the K the negative sign on a + + + align:start position:0% +put the K the negative sign on a +different I'm going to put the negative + + align:start position:0% +different I'm going to put the negative + + + align:start position:0% +different I'm going to put the negative +sign on W 2 and B instead of on W 1 so + + align:start position:0% +sign on W 2 and B instead of on W 1 so + + + align:start position:0% +sign on W 2 and B instead of on W 1 so +maybe people said yes that's a very + + align:start position:0% +maybe people said yes that's a very + + + align:start position:0% +maybe people said yes that's a very +strange actually not because of the fact + + align:start position:0% +strange actually not because of the fact + + + align:start position:0% +strange actually not because of the fact +that the pluses are on the negative + + align:start position:0% +that the pluses are on the negative + + + align:start position:0% +that the pluses are on the negative +x-axis it's just a little trick I picked + + align:start position:0% +x-axis it's just a little trick I picked + + + align:start position:0% +x-axis it's just a little trick I picked +up when one of them is negative in the + + align:start position:0% +up when one of them is negative in the + + + align:start position:0% +up when one of them is negative in the +other one is it follow the pluses so we + + align:start position:0% +other one is it follow the pluses so we + + + align:start position:0% +other one is it follow the pluses so we +know that W 1 is negative K W 2 is + + align:start position:0% +know that W 1 is negative K W 2 is + + + align:start position:0% +know that W 1 is negative K W 2 is +positive K and B is positive K w1 over + + align:start position:0% +positive K and B is positive K w1 over + + + align:start position:0% +positive K and B is positive K w1 over +w2 is negative 1 B over W 2 is positive + + align:start position:0% +w2 is negative 1 B over W 2 is positive + + + align:start position:0% +w2 is negative 1 B over W 2 is positive +1 so what do we know about the ratio of + + align:start position:0% +1 so what do we know about the ratio of + + + align:start position:0% +1 so what do we know about the ratio of +W 1 and W 2 it's equal to negative 1 and + + align:start position:0% +W 1 and W 2 it's equal to negative 1 and + + + align:start position:0% +W 1 and W 2 it's equal to negative 1 and +that means that when we square it W 1 + + align:start position:0% +that means that when we square it W 1 + + + align:start position:0% +that means that when we square it W 1 +squared equals W 2 squared so therefore + + align:start position:0% +squared equals W 2 squared so therefore + + + align:start position:0% +squared equals W 2 squared so therefore +this is the square root of 2 W 1 squared + + align:start position:0% +this is the square root of 2 W 1 squared + + + align:start position:0% +this is the square root of 2 W 1 squared +which equals root 2 W 1 equivalently + + align:start position:0% +which equals root 2 W 1 equivalently + + + align:start position:0% +which equals root 2 W 1 equivalently +well actually + + align:start position:0% +well actually + + + align:start position:0% +well actually +no it doesn't equal root 2 w 1 because W + + align:start position:0% +no it doesn't equal root 2 w 1 because W + + + align:start position:0% +no it doesn't equal root 2 w 1 because W +1 is actually negative so it we you know + + align:start position:0% +1 is actually negative so it we you know + + + align:start position:0% +1 is actually negative so it we you know +it's negative 2 W when it doesn't matter + + align:start position:0% +it's negative 2 W when it doesn't matter + + + align:start position:0% +it's negative 2 W when it doesn't matter +the point is that if that equals root 2 + + align:start position:0% +the point is that if that equals root 2 + + + align:start position:0% +the point is that if that equals root 2 +over 4 then W 1 is everyone negative 1/4 + + align:start position:0% +over 4 then W 1 is everyone negative 1/4 + + + align:start position:0% +over 4 then W 1 is everyone negative 1/4 +bingo + + align:start position:0% +bingo + + + align:start position:0% +bingo +and if W 1 is negative 1/4 everything + + align:start position:0% +and if W 1 is negative 1/4 everything + + + align:start position:0% +and if W 1 is negative 1/4 everything +else falls into place + + align:start position:0% +else falls into place + + + align:start position:0% +else falls into place +butter W 2 and B everyone positive 1/4 + + align:start position:0% +butter W 2 and B everyone positive 1/4 + + + align:start position:0% +butter W 2 and B everyone positive 1/4 +we got it we've done with this part of + + align:start position:0% +we got it we've done with this part of + + + align:start position:0% +we got it we've done with this part of +the problem however bonus let's do + + align:start position:0% +the problem however bonus let's do + + + align:start position:0% +the problem however bonus let's do +conquer the alphas which they didn't ask + + align:start position:0% +conquer the alphas which they didn't ask + + + align:start position:0% +conquer the alphas which they didn't ask +you to calculate actually you know what + + align:start position:0% +you to calculate actually you know what + + + align:start position:0% +you to calculate actually you know what +we'll do the office if we have enough + + align:start position:0% +we'll do the office if we have enough + + + align:start position:0% +we'll do the office if we have enough +time since they didn't actually ask you + + align:start position:0% +time since they didn't actually ask you + + + align:start position:0% +time since they didn't actually ask you +to calculate them however my + + align:start position:0% +to calculate them however my + + + align:start position:0% +to calculate them however my +recommendation is since there's only one + + align:start position:0% +recommendation is since there's only one + + + align:start position:0% +recommendation is since there's only one +alpha plus and 1 alpha minus they must + + align:start position:0% +alpha plus and 1 alpha minus they must + + + align:start position:0% +alpha plus and 1 alpha minus they must +be equal from this equation + + align:start position:0% +be equal from this equation + + + align:start position:0% +be equal from this equation +since this is some of the alpha plus + + align:start position:0% +since this is some of the alpha plus + + + align:start position:0% +since this is some of the alpha plus +equals the sum of the alpha minus and so + + align:start position:0% +equals the sum of the alpha minus and so + + + align:start position:0% +equals the sum of the alpha minus and so +therefore some of the W or say W equals + + align:start position:0% +therefore some of the W or say W equals + + + align:start position:0% +therefore some of the W or say W equals +the sum of W sorry should be an X of + + align:start position:0% +the sum of W sorry should be an X of + + + align:start position:0% +the sum of W sorry should be an X of +course there's not a million w's in this + + align:start position:0% +course there's not a million w's in this + + + align:start position:0% +course there's not a million w's in this +equation the sum of the points the + + align:start position:0% +equation the sum of the points the + + + align:start position:0% +equation the sum of the points the +positive data points times their alpha + + align:start position:0% +positive data points times their alpha + + + align:start position:0% +positive data points times their alpha +is minus the negative data points times + + align:start position:0% +is minus the negative data points times + + + align:start position:0% +is minus the negative data points times +their office so we're looking at here on + + align:start position:0% +their office so we're looking at here on + + + align:start position:0% +their office so we're looking at here on +negative 1/4 1/4 equals um what do we + + align:start position:0% +negative 1/4 1/4 equals um what do we + + + align:start position:0% +negative 1/4 1/4 equals um what do we +got here positive point negative 1/2 so + + align:start position:0% +got here positive point negative 1/2 so + + + align:start position:0% +got here positive point negative 1/2 so +we've got alpha plus or alpha of that + + align:start position:0% +we've got alpha plus or alpha of that + + + align:start position:0% +we've got alpha plus or alpha of that +point negative 1/2 minus alpha of that + + align:start position:0% +point negative 1/2 minus alpha of that + + + align:start position:0% +point negative 1/2 minus alpha of that +minus point and what is that it's 3 + + align:start position:0% +minus point and what is that it's 3 + + + align:start position:0% +minus point and what is that it's 3 +negative 2 3 negative 2 so if both of + + align:start position:0% +negative 2 3 negative 2 so if both of + + + align:start position:0% +negative 2 3 negative 2 so if both of +the alphas which are equal were 1 we'd + + align:start position:0% +the alphas which are equal were 1 we'd + + + align:start position:0% +the alphas which are equal were 1 we'd +have negative 4 and we'd have negative 4 + + align:start position:0% +have negative 4 and we'd have negative 4 + + + align:start position:0% +have negative 4 and we'd have negative 4 +4 but we want negative 1/4 1/4 so + + align:start position:0% +4 but we want negative 1/4 1/4 so + + + align:start position:0% +4 but we want negative 1/4 1/4 so +actually both of the alphas are 1/16 and + + align:start position:0% +actually both of the alphas are 1/16 and + + + align:start position:0% +actually both of the alphas are 1/16 and +that's the answer + + align:start position:0% +that's the answer + + + align:start position:0% +that's the answer +we'll do that boring gap if we have time + + align:start position:0% +we'll do that boring gap if we have time + + + align:start position:0% +we'll do that boring gap if we have time +but we won't so let's do number two so + + align:start position:0% +but we won't so let's do number two so + + + align:start position:0% +but we won't so let's do number two so +let's go into faster mode number two + + align:start position:0% +let's go into faster mode number two + + + align:start position:0% +let's go into faster mode number two +very similar to number one in many ways + + align:start position:0% +very similar to number one in many ways + + + align:start position:0% +very similar to number one in many ways +but as you can see one of the main + + align:start position:0% +but as you can see one of the main + + + align:start position:0% +but as you can see one of the main +things that they added an extra minus + + align:start position:0% +things that they added an extra minus + + + align:start position:0% +things that they added an extra minus +sign at two negative one so I think we + + align:start position:0% +sign at two negative one so I think we + + + align:start position:0% +sign at two negative one so I think we +can all agree that this will still be + + align:start position:0% +can all agree that this will still be + + + align:start position:0% +can all agree that this will still be +our plus actually add another plus sign + + align:start position:0% +our plus actually add another plus sign + + + align:start position:0% +our plus actually add another plus sign +there too so maybe this plus sign is a + + align:start position:0% +there too so maybe this plus sign is a + + + align:start position:0% +there too so maybe this plus sign is a +split vector but it's not this plus sign + + align:start position:0% +split vector but it's not this plus sign + + + align:start position:0% +split vector but it's not this plus sign +is the support vector what do you guys + + align:start position:0% +is the support vector what do you guys + + + align:start position:0% +is the support vector what do you guys +think about the new negative sign will + + align:start position:0% +think about the new negative sign will + + + align:start position:0% +think about the new negative sign will +it become the support vector since it is + + align:start position:0% +it become the support vector since it is + + + align:start position:0% +it become the support vector since it is +like strictly closer to the pluses yup + + align:start position:0% +like strictly closer to the pluses yup + + + align:start position:0% +like strictly closer to the pluses yup +you're right + + align:start position:0% +you're right + + + align:start position:0% +you're right +okay so this is a very beautiful + + align:start position:0% +okay so this is a very beautiful + + + align:start position:0% +okay so this is a very beautiful +division because if I do this correctly + + align:start position:0% +division because if I do this correctly + + + align:start position:0% +division because if I do this correctly +which I didn't but if we pretend that I + + align:start position:0% +which I didn't but if we pretend that I + + + align:start position:0% +which I didn't but if we pretend that I +did then the dotted line is y equals x + + align:start position:0% + + + + align:start position:0% + +okay so with the dotted line at y equals + + align:start position:0% +okay so with the dotted line at y equals + + + align:start position:0% +okay so with the dotted line at y equals +x then we know that just like we did up + + align:start position:0% +x then we know that just like we did up + + + align:start position:0% +x then we know that just like we did up +here we know that if y equals x plus 0 + + align:start position:0% +here we know that if y equals x plus 0 + + + align:start position:0% +here we know that if y equals x plus 0 +we know that first of all B equals 0 + + align:start position:0% +we know that first of all B equals 0 + + + align:start position:0% +we know that first of all B equals 0 +second of all we know that we've got + + align:start position:0% +second of all we know that we've got + + + align:start position:0% +second of all we know that we've got +just with y equals x then we know that + + align:start position:0% +just with y equals x then we know that + + + align:start position:0% +just with y equals x then we know that +negative w1 over w2 equals 1 the plus + + align:start position:0% +negative w1 over w2 equals 1 the plus + + + align:start position:0% +negative w1 over w2 equals 1 the plus +are still on the left and up so we know + + align:start position:0% +are still on the left and up so we know + + + align:start position:0% +are still on the left and up so we know +that w1 is some negative number negative + + align:start position:0% +that w1 is some negative number negative + + + align:start position:0% +that w1 is some negative number negative +K w2 is some positive number K great how + + align:start position:0% +K w2 is some positive number K great how + + + align:start position:0% +K w2 is some positive number K great how +are we going to figure it out well let's + + align:start position:0% +are we going to figure it out well let's + + + align:start position:0% +are we going to figure it out well let's +call that this D for distance or + + align:start position:0% +call that this D for distance or + + + align:start position:0% +call that this D for distance or +whatever you want to call it so on over + + align:start position:0% +whatever you want to call it so on over + + + align:start position:0% +whatever you want to call it so on over +W equals D D in this case is not on 2 + + align:start position:0% +W equals D D in this case is not on 2 + + + align:start position:0% +W equals D D in this case is not on 2 +root 2 can everyone tell what D is here + + align:start position:0% + + + + align:start position:0% + +it's actually so it goes over two and + + align:start position:0% +it's actually so it goes over two and + + + align:start position:0% +it's actually so it goes over two and +one so it should be one and a half root + + align:start position:0% +one so it should be one and a half root + + + align:start position:0% +one so it should be one and a half root +two + + align:start position:0% +two + + + align:start position:0% +two +since this with distance which is twice + + align:start position:0% +since this with distance which is twice + + + align:start position:0% +since this with distance which is twice +as much goes over 3 and 3 which is 3 + + align:start position:0% +as much goes over 3 and 3 which is 3 + + + align:start position:0% +as much goes over 3 and 3 which is 3 +root 2 so it's one and a half root 2 I + + align:start position:0% +root 2 so it's one and a half root 2 I + + + align:start position:0% +root 2 so it's one and a half root 2 I +don't like putting in decimals and stuff + + align:start position:0% +don't like putting in decimals and stuff + + + align:start position:0% +don't like putting in decimals and stuff +there so we'll say that 2 over negative + + align:start position:0% +there so we'll say that 2 over negative + + + align:start position:0% +there so we'll say that 2 over negative +W equals to D equals 3 root 2 so + + align:start position:0% +W equals to D equals 3 root 2 so + + + align:start position:0% +W equals to D equals 3 root 2 so +therefore right high-diving 1 2 3 1 2 3 + + align:start position:0% +therefore right high-diving 1 2 3 1 2 3 + + + align:start position:0% +therefore right high-diving 1 2 3 1 2 3 +3 root 2 so therefore magnitude of W + + align:start position:0% +3 root 2 so therefore magnitude of W + + + align:start position:0% +3 root 2 so therefore magnitude of W +equals let's see switch them over we + + align:start position:0% +equals let's see switch them over we + + + align:start position:0% +equals let's see switch them over we +should get root 2 over 3 and it's + + align:start position:0% +should get root 2 over 3 and it's + + + align:start position:0% +should get root 2 over 3 and it's +magnitude of W is root 2 over 3 we can + + align:start position:0% +magnitude of W is root 2 over 3 we can + + + align:start position:0% +magnitude of W is root 2 over 3 we can +do our same trick from before square + + align:start position:0% +do our same trick from before square + + + align:start position:0% +do our same trick from before square +root of 2 W 2 squared equals root 2 over + + align:start position:0% +root of 2 W 2 squared equals root 2 over + + + align:start position:0% +root of 2 W 2 squared equals root 2 over +3 and this is just root 2 times W 2 + + align:start position:0% +3 and this is just root 2 times W 2 + + + align:start position:0% +3 and this is just root 2 times W 2 +equals root 2 over 3 so therefore W 2 is + + align:start position:0% +equals root 2 over 3 so therefore W 2 is + + + align:start position:0% +equals root 2 over 3 so therefore W 2 is +1/3 and W 1 is negative 1/3 bingo we've + + align:start position:0% +1/3 and W 1 is negative 1/3 bingo we've + + + align:start position:0% +1/3 and W 1 is negative 1/3 bingo we've +got W 1 we've got W - we know that B was + + align:start position:0% +got W 1 we've got W - we know that B was + + + align:start position:0% +got W 1 we've got W - we know that B was +0 because obviously at 0 its y equals x + + align:start position:0% +0 because obviously at 0 its y equals x + + + align:start position:0% +0 because obviously at 0 its y equals x +and we're done + + align:start position:0% +and we're done + + + align:start position:0% +and we're done +ah that was fast the alphas might have + + align:start position:0% +ah that was fast the alphas might have + + + align:start position:0% +ah that was fast the alphas might have +taken longer actually the alphas on this + + align:start position:0% +taken longer actually the alphas on this + + + align:start position:0% +taken longer actually the alphas on this +one or more of a pain in the ass than + + align:start position:0% +one or more of a pain in the ass than + + + align:start position:0% +one or more of a pain in the ass than +anywhere else because let's take a look + + align:start position:0% +anywhere else because let's take a look + + + align:start position:0% +anywhere else because let's take a look +at this one if you can see it we've + + align:start position:0% +at this one if you can see it we've + + + align:start position:0% +at this one if you can see it we've +added yet some new points we've got this + + align:start position:0% +added yet some new points we've got this + + + align:start position:0% +added yet some new points we've got this +point up here this point down there so I + + align:start position:0% +point up here this point down there so I + + + align:start position:0% +point up here this point down there so I +think pretty clearly these plus and + + align:start position:0% +think pretty clearly these plus and + + + align:start position:0% +think pretty clearly these plus and +minus are the closest to each other but + + align:start position:0% +minus are the closest to each other but + + + align:start position:0% +minus are the closest to each other but +what happens if we take the + + align:start position:0% +what happens if we take the + + + align:start position:0% +what happens if we take the +perpendicular bisector between these two + + align:start position:0% +perpendicular bisector between these two + + + align:start position:0% +perpendicular bisector between these two +and dude like this this plus is in the + + align:start position:0% +and dude like this this plus is in the + + + align:start position:0% +and dude like this this plus is in the +middle so we're going to have 2 feet so + + align:start position:0% +middle so we're going to have 2 feet so + + + align:start position:0% +middle so we're going to have 2 feet so +therefore this plus is going to have to + + align:start position:0% +therefore this plus is going to have to + + + align:start position:0% +therefore this plus is going to have to +also be support vector so we can't just + + align:start position:0% +also be support vector so we can't just + + + align:start position:0% +also be support vector so we can't just +draw this line we have to include this + + align:start position:0% +draw this line we have to include this + + + align:start position:0% +draw this line we have to include this +what's our best division + + align:start position:0% + + + + align:start position:0% + +vertical lines that's right vertical + + align:start position:0% +vertical lines that's right vertical + + + align:start position:0% +vertical lines that's right vertical +lines just saw and that means that the + + align:start position:0% +lines just saw and that means that the + + + align:start position:0% +lines just saw and that means that the +equation of our equation of our boundary + + align:start position:0% +equation of our equation of our boundary + + + align:start position:0% +equation of our equation of our boundary +the dotted line here y-axis so the + + align:start position:0% +the dotted line here y-axis so the + + + align:start position:0% +the dotted line here y-axis so the +equation of the boundary of the y-axis + + align:start position:0% +equation of the boundary of the y-axis + + + align:start position:0% +equation of the boundary of the y-axis +then B equals zero and how W 2 equals + + align:start position:0% +then B equals zero and how W 2 equals + + + align:start position:0% +then B equals zero and how W 2 equals +zero so the only thing that is not W 2 + + align:start position:0% +zero so the only thing that is not W 2 + + + align:start position:0% +zero so the only thing that is not W 2 +equals 0 so W 2 equals 0 B equals 0 but + + align:start position:0% +equals 0 so W 2 equals 0 B equals 0 but + + + align:start position:0% +equals 0 so W 2 equals 0 B equals 0 but +W 1 is not equal to 0 because it's just + + align:start position:0% +W 1 is not equal to 0 because it's just + + + align:start position:0% +W 1 is not equal to 0 because it's just +the equation of the y-axis so we + + align:start position:0% +the equation of the y-axis so we + + + align:start position:0% +the equation of the y-axis so we +therefore know that the equation is just + + align:start position:0% + + + + align:start position:0% + +W 1 times x equals 0 + + align:start position:0% + + + + align:start position:0% + +so if w1 times x equals zero and we know + + align:start position:0% +so if w1 times x equals zero and we know + + + align:start position:0% +so if w1 times x equals zero and we know +that that just means essentially that X + + align:start position:0% +that that just means essentially that X + + + align:start position:0% +that that just means essentially that X +is going to be some K it's also going to + + align:start position:0% +is going to be some K it's also going to + + + align:start position:0% +is going to be some K it's also going to +be negative because of the fact that + + align:start position:0% +be negative because of the fact that + + + align:start position:0% +be negative because of the fact that +that plus is our store on the left then + + align:start position:0% +that plus is our store on the left then + + + align:start position:0% +that plus is our store on the left then +we're going to figure out what that K is + + align:start position:0% +we're going to figure out what that K is + + + align:start position:0% +we're going to figure out what that K is +we'll use our old trick + + align:start position:0% +we'll use our old trick + + + align:start position:0% +we'll use our old trick +by this point old hopefully one over + + align:start position:0% +by this point old hopefully one over + + + align:start position:0% +by this point old hopefully one over +magnitude of W equals D this time D is + + align:start position:0% +magnitude of W equals D this time D is + + + align:start position:0% +magnitude of W equals D this time D is +just 1 so therefore magnitude of W + + align:start position:0% +just 1 so therefore magnitude of W + + + align:start position:0% +just 1 so therefore magnitude of W +equals one there's only one component in + + align:start position:0% +equals one there's only one component in + + + align:start position:0% +equals one there's only one component in +W so therefore W 1 is minus 1 because + + align:start position:0% +W so therefore W 1 is minus 1 because + + + align:start position:0% +W so therefore W 1 is minus 1 because +the plus is on the left people see that + + align:start position:0% +the plus is on the left people see that + + + align:start position:0% +the plus is on the left people see that +not too bad + + align:start position:0% +not too bad + + + align:start position:0% +not too bad +this one's easy to calculate a W but + + align:start position:0% +this one's easy to calculate a W but + + + align:start position:0% +this one's easy to calculate a W but +it's not as easy to get all the alphas + + align:start position:0% +it's not as easy to get all the alphas + + + align:start position:0% +it's not as easy to get all the alphas +but let's move on to a new and even more + + align:start position:0% +but let's move on to a new and even more + + + align:start position:0% +but let's move on to a new and even more +fun maybe not + + align:start position:0% +fun maybe not + + + align:start position:0% +fun maybe not +um question which is this guy as you can + + align:start position:0% +um question which is this guy as you can + + + align:start position:0% +um question which is this guy as you can +see this is a lease this well maybe not + + align:start position:0% +see this is a lease this well maybe not + + + align:start position:0% +see this is a lease this well maybe not +this is a one-dimensional vector these + + align:start position:0% +this is a one-dimensional vector these + + + align:start position:0% +this is a one-dimensional vector these +vectors only have a single dimension so + + align:start position:0% +vectors only have a single dimension so + + + align:start position:0% +vectors only have a single dimension so +it just looks like a number line here + + align:start position:0% +it just looks like a number line here + + + align:start position:0% +it just looks like a number line here +that dimension varies from it looks like + + align:start position:0% +that dimension varies from it looks like + + + align:start position:0% +that dimension varies from it looks like +negative 9 to positive 9 either just has + + align:start position:0% +negative 9 to positive 9 either just has + + + align:start position:0% +negative 9 to positive 9 either just has +one component you don't have to worry + + align:start position:0% +one component you don't have to worry + + + align:start position:0% +one component you don't have to worry +about any of these crazy magnitudes with + + align:start position:0% +about any of these crazy magnitudes with + + + align:start position:0% +about any of these crazy magnitudes with +two components just everything as a + + align:start position:0% +two components just everything as a + + + align:start position:0% +two components just everything as a +single component however it's obvious + + align:start position:0% +single component however it's obvious + + + align:start position:0% +single component however it's obvious +that a linear basis line is going to + + align:start position:0% +that a linear basis line is going to + + + align:start position:0% +that a linear basis line is going to +completely screw us up here since lines + + align:start position:0% +completely screw us up here since lines + + + align:start position:0% +completely screw us up here since lines +at this point are just like glump all + + align:start position:0% +at this point are just like glump all + + + align:start position:0% +at this point are just like glump all +these are pluses all these are Mises + + align:start position:0% +these are pluses all these are Mises + + + align:start position:0% +these are pluses all these are Mises +well not great that doesn't get them off + + align:start position:0% +well not great that doesn't get them off + + + align:start position:0% +well not great that doesn't get them off +so how are we going to do it well we're + + align:start position:0% +so how are we going to do it well we're + + + align:start position:0% +so how are we going to do it well we're +going to use what is usually perhaps the + + align:start position:0% +going to use what is usually perhaps the + + + align:start position:0% +going to use what is usually perhaps the +hardest thing in SVM's but in this case + + align:start position:0% +hardest thing in SVM's but in this case + + + align:start position:0% +hardest thing in SVM's but in this case +is not going to be too bad for us we're + + align:start position:0% +is not going to be too bad for us we're + + + align:start position:0% +is not going to be too bad for us we're +going to use a kernel now based on how + + align:start position:0% +going to use a kernel now based on how + + + align:start position:0% +going to use a kernel now based on how +little I understood kernels the first + + align:start position:0% +little I understood kernels the first + + + align:start position:0% +little I understood kernels the first +time I've took this class I'm guessing + + align:start position:0% +time I've took this class I'm guessing + + + align:start position:0% +time I've took this class I'm guessing +that you guys would like to have some + + align:start position:0% +that you guys would like to have some + + + align:start position:0% +that you guys would like to have some +explanation on these kernels you + + align:start position:0% +explanation on these kernels you + + + align:start position:0% +explanation on these kernels you +probably saw them you remember the + + align:start position:0% +probably saw them you remember the + + + align:start position:0% +probably saw them you remember the +kernels from Patrick's lecture vaguely + + align:start position:0% +kernels from Patrick's lecture vaguely + + + align:start position:0% +kernels from Patrick's lecture vaguely +they're like this Phi and then there's + + align:start position:0% +they're like this Phi and then there's + + + align:start position:0% +they're like this Phi and then there's +this K and then they get really + + align:start position:0% +this K and then they get really + + + align:start position:0% +this K and then they get really +complicated okay so here's how the + + align:start position:0% +complicated okay so here's how the + + + align:start position:0% +complicated okay so here's how the +kernel works the basic idea is this + + align:start position:0% +kernel works the basic idea is this + + + align:start position:0% +kernel works the basic idea is this +and I'll write it over here + + align:start position:0% +and I'll write it over here + + + align:start position:0% +and I'll write it over here +oh wow there's more stuff okay I'll + + align:start position:0% +oh wow there's more stuff okay I'll + + + align:start position:0% +oh wow there's more stuff okay I'll +write it right here the basic idea is + + align:start position:0% +write it right here the basic idea is + + + align:start position:0% +write it right here the basic idea is +this we're taking the normal space which + + align:start position:0% +this we're taking the normal space which + + + align:start position:0% +this we're taking the normal space which +is you know this number line or it could + + align:start position:0% +is you know this number line or it could + + + align:start position:0% +is you know this number line or it could +be any kind of normal space and we're + + align:start position:0% +be any kind of normal space and we're + + + align:start position:0% +be any kind of normal space and we're +going to take a vector we're going to + + align:start position:0% +going to take a vector we're going to + + + align:start position:0% +going to take a vector we're going to +put it into it of a function called Phi + + align:start position:0% +put it into it of a function called Phi + + + align:start position:0% +put it into it of a function called Phi +and Phi of vector X brings X into some + + align:start position:0% +and Phi of vector X brings X into some + + + align:start position:0% +and Phi of vector X brings X into some +new dimension Phi or fee if you like it + + align:start position:0% +new dimension Phi or fee if you like it + + + align:start position:0% +new dimension Phi or fee if you like it +better is usually a nasty piece of work + + align:start position:0% +better is usually a nasty piece of work + + + align:start position:0% +better is usually a nasty piece of work +and something that you'd never ever want + + align:start position:0% +and something that you'd never ever want + + + align:start position:0% +and something that you'd never ever want +to look at sometimes it's not too bad + + align:start position:0% +to look at sometimes it's not too bad + + + align:start position:0% +to look at sometimes it's not too bad +Phi is the function that brings it into + + align:start position:0% +Phi is the function that brings it into + + + align:start position:0% +Phi is the function that brings it into +the new dimension okay and when you + + align:start position:0% +the new dimension okay and when you + + + align:start position:0% +the new dimension okay and when you +brought the data into a new dimension + + align:start position:0% +brought the data into a new dimension + + + align:start position:0% +brought the data into a new dimension +sometimes you can just cut a straight + + align:start position:0% +sometimes you can just cut a straight + + + align:start position:0% +sometimes you can just cut a straight +line in that dimension and you'll just + + align:start position:0% +line in that dimension and you'll just + + + align:start position:0% +line in that dimension and you'll just +be happy however something that was + + align:start position:0% +be happy however something that was + + + align:start position:0% +be happy however something that was +noted by the very very smart inventor of + + align:start position:0% +noted by the very very smart inventor of + + + align:start position:0% +noted by the very very smart inventor of +support vector machines is that you + + align:start position:0% +support vector machines is that you + + + align:start position:0% +support vector machines is that you +don't actually need to to work with + + align:start position:0% +don't actually need to to work with + + + align:start position:0% +don't actually need to to work with +function Phi + + align:start position:0% +function Phi + + + align:start position:0% +function Phi +even if Phi is an absolutely horrible + + align:start position:0% +even if Phi is an absolutely horrible + + + align:start position:0% +even if Phi is an absolutely horrible +monstrosity because of the fact that you + + align:start position:0% +monstrosity because of the fact that you + + + align:start position:0% +monstrosity because of the fact that you +never need to know what the vector X + + align:start position:0% +never need to know what the vector X + + + align:start position:0% +never need to know what the vector X +what all these vectors X actually are in + + align:start position:0% +what all these vectors X actually are in + + + align:start position:0% +what all these vectors X actually are in +the new space at least not directly in + + align:start position:0% +the new space at least not directly in + + + align:start position:0% +the new space at least not directly in +none of these equations up here do we + + align:start position:0% +none of these equations up here do we + + + align:start position:0% +none of these equations up here do we +ever use X by itself however we do use X + + align:start position:0% +ever use X by itself however we do use X + + + align:start position:0% +ever use X by itself however we do use X +being dot product with something else so + + align:start position:0% +being dot product with something else so + + + align:start position:0% +being dot product with something else so +he figured out a very sneaky and + + align:start position:0% +he figured out a very sneaky and + + + align:start position:0% +he figured out a very sneaky and +excellent shortcut okay so I shouldn't + + align:start position:0% +excellent shortcut okay so I shouldn't + + + align:start position:0% +excellent shortcut okay so I shouldn't +use x1 x2 L use X and Z so if you have + + align:start position:0% +use x1 x2 L use X and Z so if you have + + + align:start position:0% +use x1 x2 L use X and Z so if you have +two vectors X and Z which are in a + + align:start position:0% +two vectors X and Z which are in a + + + align:start position:0% +two vectors X and Z which are in a +regular space you put them into this + + align:start position:0% +regular space you put them into this + + + align:start position:0% +regular space you put them into this +function called the kernel then it will + + align:start position:0% +function called the kernel then it will + + + align:start position:0% +function called the kernel then it will +tell you Phi of X dotted with 5z + + align:start position:0% +tell you Phi of X dotted with 5z + + + align:start position:0% +tell you Phi of X dotted with 5z +and if you have that you don't need five + + align:start position:0% +and if you have that you don't need five + + + align:start position:0% +and if you have that you don't need five +does everyone see that + + align:start position:0% +does everyone see that + + + align:start position:0% +does everyone see that +does everyone see why we don't need five + + align:start position:0% +does everyone see why we don't need five + + + align:start position:0% +does everyone see why we don't need five +look at all these equations up here we + + align:start position:0% +look at all these equations up here we + + + align:start position:0% +look at all these equations up here we +never look at X by itself in these in + + align:start position:0% +never look at X by itself in these in + + + align:start position:0% +never look at X by itself in these in +these vector equations at least now + + align:start position:0% +these vector equations at least now + + + align:start position:0% +these vector equations at least now +calculating alphas yeah that gets a + + align:start position:0% +calculating alphas yeah that gets a + + + align:start position:0% +calculating alphas yeah that gets a +little bit fuzzy but in the vector but + + align:start position:0% +little bit fuzzy but in the vector but + + + align:start position:0% +little bit fuzzy but in the vector but +in the vector equations also you get you + + align:start position:0% +in the vector equations also you get you + + + align:start position:0% +in the vector equations also you get you +may ask like why would you do this you + + align:start position:0% +may ask like why would you do this you + + + align:start position:0% +may ask like why would you do this you +can't complete the alphas it turns out + + align:start position:0% +can't complete the alphas it turns out + + + align:start position:0% +can't complete the alphas it turns out +we're um that actually other than for + + align:start position:0% +we're um that actually other than for + + + align:start position:0% +we're um that actually other than for +these very simple linear problems human + + align:start position:0% +these very simple linear problems human + + + align:start position:0% +these very simple linear problems human +minds cannot calculate the alphas in + + align:start position:0% +minds cannot calculate the alphas in + + + align:start position:0% +minds cannot calculate the alphas in +fact you run a very complicated + + align:start position:0% +fact you run a very complicated + + + align:start position:0% +fact you run a very complicated +quadratic optimization in fact finding + + align:start position:0% +quadratic optimization in fact finding + + + align:start position:0% +quadratic optimization in fact finding +out the best alphas is the thing that + + align:start position:0% +out the best alphas is the thing that + + + align:start position:0% +out the best alphas is the thing that +you will climb on when you're doing + + align:start position:0% +you will climb on when you're doing + + + align:start position:0% +you will climb on when you're doing +SVM's + + align:start position:0% +SVM's + + + align:start position:0% +SVM's +in the real world you say alright I'll + + align:start position:0% +in the real world you say alright I'll + + + align:start position:0% +in the real world you say alright I'll +run my algorithm and I know there's only + + align:start position:0% +run my algorithm and I know there's only + + + align:start position:0% +run my algorithm and I know there's only +one peak which is very very good because + + align:start position:0% +one peak which is very very good because + + + align:start position:0% +one peak which is very very good because +it's quadratic optimization let me + + align:start position:0% +it's quadratic optimization let me + + + align:start position:0% +it's quadratic optimization let me +figure out the office so in fact it + + align:start position:0% +figure out the office so in fact it + + + align:start position:0% +figure out the office so in fact it +doesn't matter that you can't do that + + align:start position:0% +doesn't matter that you can't do that + + + align:start position:0% +doesn't matter that you can't do that +use these alpha places to figure out the + + align:start position:0% +use these alpha places to figure out the + + + align:start position:0% +use these alpha places to figure out the +alphas um if you've gone into if you + + align:start position:0% +alphas um if you've gone into if you + + + align:start position:0% +alphas um if you've gone into if you +only know the kernel function out the + + align:start position:0% +only know the kernel function out the + + + align:start position:0% +only know the kernel function out the +Phi function because normally the + + align:start position:0% +Phi function because normally the + + + align:start position:0% +Phi function because normally the +computer figures out the alphas for you + + align:start position:0% +computer figures out the alphas for you + + + align:start position:0% +computer figures out the alphas for you +with quadratic optimization just in + + align:start position:0% +with quadratic optimization just in + + + align:start position:0% +with quadratic optimization just in +these simple problems we know you can + + align:start position:0% +these simple problems we know you can + + + align:start position:0% +these simple problems we know you can +calculate the alphas so we have the + + align:start position:0% +calculate the alphas so we have the + + + align:start position:0% +calculate the alphas so we have the +kernel which replaces that basically + + align:start position:0% +kernel which replaces that basically + + + align:start position:0% +kernel which replaces that basically +gives us the dot product of the things + + align:start position:0% +gives us the dot product of the things + + + align:start position:0% +gives us the dot product of the things +in the new space so being that as it may + + align:start position:0% +in the new space so being that as it may + + + align:start position:0% +in the new space so being that as it may +I'll give you the kernel here I'd like + + align:start position:0% +I'll give you the kernel here I'd like + + + align:start position:0% +I'll give you the kernel here I'd like +you to give me the Phi so a kernel for + + align:start position:0% +you to give me the Phi so a kernel for + + + align:start position:0% +you to give me the Phi so a kernel for +that someone got an idea whose name was + + align:start position:0% +that someone got an idea whose name was + + + align:start position:0% +that someone got an idea whose name was +Susan Q random student apparently she + + align:start position:0% +Susan Q random student apparently she + + + align:start position:0% +Susan Q random student apparently she +got an idea that if we had a kernel for + + align:start position:0% +got an idea that if we had a kernel for + + + align:start position:0% +got an idea that if we had a kernel for +X and Z actually they're not vectors I + + align:start position:0% +X and Z actually they're not vectors I + + + align:start position:0% +X and Z actually they're not vectors I +guess they're just single components and + + align:start position:0% +guess they're just single components and + + + align:start position:0% +guess they're just single components and +the kernel equals cosine PI over 4 x + + align:start position:0% +the kernel equals cosine PI over 4 x + + + align:start position:0% +the kernel equals cosine PI over 4 x +times cosine pi over 4z plus sine PI + + align:start position:0% +times cosine pi over 4z plus sine PI + + + align:start position:0% +times cosine pi over 4z plus sine PI +over 4 X plus + + align:start position:0% +over 4 X plus + + + align:start position:0% +over 4 X plus +pi over 4z so that is the new dot + + align:start position:0% +pi over 4z so that is the new dot + + + align:start position:0% +pi over 4z so that is the new dot +product cosine PI over 4x + + align:start position:0% +product cosine PI over 4x + + + align:start position:0% +product cosine PI over 4x +oh wait sorry I put one of the disease + + align:start position:0% +oh wait sorry I put one of the disease + + + align:start position:0% +oh wait sorry I put one of the disease +not inside the parenthesis that was + + align:start position:0% +not inside the parenthesis that was + + + align:start position:0% +not inside the parenthesis that was +still with me so cosine of the quantity + + align:start position:0% +still with me so cosine of the quantity + + + align:start position:0% +still with me so cosine of the quantity +PI over 4 x times cosine is upon T pi + + align:start position:0% +PI over 4 x times cosine is upon T pi + + + align:start position:0% +PI over 4 x times cosine is upon T pi +over 4z plus sine is upon T PI over 4 X + + align:start position:0% +over 4z plus sine is upon T PI over 4 X + + + align:start position:0% +over 4z plus sine is upon T PI over 4 X +plus sine of the quantity PI over 4 z is + + align:start position:0% +plus sine of the quantity PI over 4 z is + + + align:start position:0% +plus sine of the quantity PI over 4 z is +the new dot product so that begs the + + align:start position:0% +the new dot product so that begs the + + + align:start position:0% +the new dot product so that begs the +question in this one this is an easy one + + align:start position:0% +question in this one this is an easy one + + + align:start position:0% +question in this one this is an easy one +so we can calculate the 5 what is Phi of + + align:start position:0% +so we can calculate the 5 what is Phi of + + + align:start position:0% +so we can calculate the 5 what is Phi of +X we're actually taking it from one + + align:start position:0% +X we're actually taking it from one + + + align:start position:0% +X we're actually taking it from one +dimension and we may be playing around + + align:start position:0% +dimension and we may be playing around + + + align:start position:0% +dimension and we may be playing around +with it a lot to get this this thing has + + align:start position:0% +with it a lot to get this this thing has + + + align:start position:0% +with it a lot to get this this thing has +become a new dot product it replaces dot + + align:start position:0% +become a new dot product it replaces dot + + + align:start position:0% +become a new dot product it replaces dot +product now remember the dot part for + + align:start position:0% +product now remember the dot part for + + + align:start position:0% +product now remember the dot part for +scalars would have just been multiplying + + align:start position:0% +scalars would have just been multiplying + + + align:start position:0% +scalars would have just been multiplying +the two numbers together so it actually + + align:start position:0% +the two numbers together so it actually + + + align:start position:0% +the two numbers together so it actually +makes it a little bit more complicated + + align:start position:0% +makes it a little bit more complicated + + + align:start position:0% +makes it a little bit more complicated +does anyone think they know the Phi + + align:start position:0% +does anyone think they know the Phi + + + align:start position:0% +does anyone think they know the Phi +ah we got one what do you think you need + + align:start position:0% +ah we got one what do you think you need + + + align:start position:0% +ah we got one what do you think you need +to come back two dimensional absolutely + + align:start position:0% +to come back two dimensional absolutely + + + align:start position:0% +to come back two dimensional absolutely +that's exactly correct how would you + + align:start position:0% +that's exactly correct how would you + + + align:start position:0% +that's exactly correct how would you +solve this on the next whole quiz if + + align:start position:0% +solve this on the next whole quiz if + + + align:start position:0% +solve this on the next whole quiz if +you're not our brave volunteer + + align:start position:0% +you're not our brave volunteer + + + align:start position:0% +you're not our brave volunteer +well that K if you squint at it not very + + align:start position:0% +well that K if you squint at it not very + + + align:start position:0% +well that K if you squint at it not very +much actually it's pretty much a dot + + align:start position:0% +much actually it's pretty much a dot + + + align:start position:0% +much actually it's pretty much a dot +product between cosine PI over 4 s and + + align:start position:0% +product between cosine PI over 4 s and + + + align:start position:0% +product between cosine PI over 4 s and +sine PI over 4 is I mean look at it dot + + align:start position:0% +sine PI over 4 is I mean look at it dot + + + align:start position:0% +sine PI over 4 is I mean look at it dot +product is just remember if the dot + + align:start position:0% +product is just remember if the dot + + + align:start position:0% +product is just remember if the dot +product of X and Z vectors is X 1 is X 1 + + align:start position:0% +product of X and Z vectors is X 1 is X 1 + + + align:start position:0% +product of X and Z vectors is X 1 is X 1 +Z 1 plus X 2 Z 2 so that basically is X + + align:start position:0% +Z 1 plus X 2 Z 2 so that basically is X + + + align:start position:0% +Z 1 plus X 2 Z 2 so that basically is X +1 Z 1 plus X 2 Z 2 o this should have + + align:start position:0% +1 Z 1 plus X 2 Z 2 o this should have + + + align:start position:0% +1 Z 1 plus X 2 Z 2 o this should have +been many times + + align:start position:0% +been many times + + + align:start position:0% +been many times +yeah there's trillion times sorry + + align:start position:0% +yeah there's trillion times sorry + + + align:start position:0% +yeah there's trillion times sorry +there's a plus there anyone who missed + + align:start position:0% +there's a plus there anyone who missed + + + align:start position:0% +there's a plus there anyone who missed +it because of that my bad that should + + align:start position:0% +it because of that my bad that should + + + align:start position:0% +it because of that my bad that should +have been a x there should've been times + + align:start position:0% +have been a x there should've been times + + + align:start position:0% +have been a x there should've been times +up there the plot only plus is its + + align:start position:0% +up there the plot only plus is its + + + align:start position:0% +up there the plot only plus is its +cosine PI over 4 X cosine 2 pi over 4z + + align:start position:0% +cosine PI over 4 X cosine 2 pi over 4z + + + align:start position:0% +cosine PI over 4 X cosine 2 pi over 4z +plus sine PI over 4 x times sine PI over + + align:start position:0% +plus sine PI over 4 x times sine PI over + + + align:start position:0% +plus sine PI over 4 x times sine PI over +4 Z so yeah it's basically the dot + + align:start position:0% +4 Z so yeah it's basically the dot + + + align:start position:0% +4 Z so yeah it's basically the dot +product between cosine PI over 4 X and + + align:start position:0% +product between cosine PI over 4 X and + + + align:start position:0% +product between cosine PI over 4 X and +sine PI + + align:start position:0% +sine PI + + + align:start position:0% +sine PI +for bingo all right last thing and then + + align:start position:0% +for bingo all right last thing and then + + + align:start position:0% +for bingo all right last thing and then +we well we're not done yet because we're + + align:start position:0% +we well we're not done yet because we're + + + align:start position:0% +we well we're not done yet because we're +going to maybe ask some questions and + + align:start position:0% +going to maybe ask some questions and + + + align:start position:0% +going to maybe ask some questions and +then we're going to see if we can + + align:start position:0% +then we're going to see if we can + + + align:start position:0% +then we're going to see if we can +conquer those alphas but last thing + + align:start position:0% +conquer those alphas but last thing + + + align:start position:0% +conquer those alphas but last thing +let's graph in this new dimension all + + align:start position:0% +let's graph in this new dimension all + + + align:start position:0% +let's graph in this new dimension all +the points + + align:start position:0% +the points + + + align:start position:0% +the points +so obviously cosines and sines so we're + + align:start position:0% +so obviously cosines and sines so we're + + + align:start position:0% +so obviously cosines and sines so we're +going to get results between 1 and minus + + align:start position:0% +going to get results between 1 and minus + + + align:start position:0% +going to get results between 1 and minus +1 let's see maybe I can graph it um can + + align:start position:0% +1 let's see maybe I can graph it um can + + + align:start position:0% +1 let's see maybe I can graph it um can +I write on all these wait maybe this one + + align:start position:0% +I write on all these wait maybe this one + + + align:start position:0% +I write on all these wait maybe this one +oh no people do weird stick figures + + align:start position:0% +oh no people do weird stick figures + + + align:start position:0% +oh no people do weird stick figures +there ok + + align:start position:0% +there ok + + + align:start position:0% +there ok +oh yeah this one's kind of messy but + + align:start position:0% +oh yeah this one's kind of messy but + + + align:start position:0% +oh yeah this one's kind of messy but +we'll do it on this ok so we've got this + + align:start position:0% +we'll do it on this ok so we've got this + + + align:start position:0% +we'll do it on this ok so we've got this +is 1 negative 1 1 half and 1 or so 1/2 + + align:start position:0% +is 1 negative 1 1 half and 1 or so 1/2 + + + align:start position:0% +is 1 negative 1 1 half and 1 or so 1/2 +negative 1/2 1 negative 1 negative 1/2 + + align:start position:0% +negative 1/2 1 negative 1 negative 1/2 + + + align:start position:0% +negative 1/2 1 negative 1 negative 1/2 +1/2 + + align:start position:0% +1/2 + + + align:start position:0% +1/2 +ok so given that let's try to graph all + + align:start position:0% +ok so given that let's try to graph all + + + align:start position:0% +ok so given that let's try to graph all +these points on this number line into + + align:start position:0% +these points on this number line into + + + align:start position:0% +these points on this number line into +this new brave new dimension by using + + align:start position:0% +this new brave new dimension by using + + + align:start position:0% +this new brave new dimension by using +their cosine sine PI over 4 so all right + + align:start position:0% +their cosine sine PI over 4 so all right + + + align:start position:0% +their cosine sine PI over 4 so all right +great so let's do the pluses first what + + align:start position:0% +great so let's do the pluses first what + + + align:start position:0% +great so let's do the pluses first what +about the plus X 0 is cosine 0 sine 0 so + + align:start position:0% +about the plus X 0 is cosine 0 sine 0 so + + + align:start position:0% +about the plus X 0 is cosine 0 sine 0 so +what is that that's 1 0 that's right + + align:start position:0% + + + + align:start position:0% + +in fact the 8 and the minus 8 are also + + align:start position:0% +in fact the 8 and the minus 8 are also + + + align:start position:0% +in fact the 8 and the minus 8 are also +that times 3 the eight of the minus 8 + + align:start position:0% +that times 3 the eight of the minus 8 + + + align:start position:0% +that times 3 the eight of the minus 8 +are also that because then it's just 2 + + align:start position:0% +are also that because then it's just 2 + + + align:start position:0% +are also that because then it's just 2 +pi n minus 2 pi which well cosine and + + align:start position:0% +pi n minus 2 pi which well cosine and + + + align:start position:0% +pi n minus 2 pi which well cosine and +sine are periodic ok great + + align:start position:0% +sine are periodic ok great + + + align:start position:0% +sine are periodic ok great +what about the one well that's cosine PI + + align:start position:0% +what about the one well that's cosine PI + + + align:start position:0% +what about the one well that's cosine PI +over 4 sine PI over 4 what's that + + align:start position:0% + + + + align:start position:0% + +yeah it's root 2 over 2 root 2 over 2 so + + align:start position:0% +yeah it's root 2 over 2 root 2 over 2 so + + + align:start position:0% +yeah it's root 2 over 2 root 2 over 2 so +it's something like here we'll say and + + align:start position:0% +it's something like here we'll say and + + + align:start position:0% +it's something like here we'll say and +in fact the 9 and the 9 and the negative + + align:start position:0% +in fact the 9 and the 9 and the negative + + + align:start position:0% +in fact the 9 and the 9 and the negative +7 are also that so there's three of + + align:start position:0% +7 are also that so there's three of + + + align:start position:0% +7 are also that so there's three of +these two okay what about the negative + + align:start position:0% +these two okay what about the negative + + + align:start position:0% +these two okay what about the negative +one that's cosine negative PI over 4 + + align:start position:0% +one that's cosine negative PI over 4 + + + align:start position:0% +one that's cosine negative PI over 4 +sine PI over 4 that's right the x value + + align:start position:0% +sine PI over 4 that's right the x value + + + align:start position:0% +sine PI over 4 that's right the x value +is positive root 2 over 2 and the y + + align:start position:0% +is positive root 2 over 2 and the y + + + align:start position:0% +is positive root 2 over 2 and the y +value is negative so and again there's + + align:start position:0% +value is negative so and again there's + + + align:start position:0% +value is negative so and again there's +three of them all right great now let's + + align:start position:0% +three of them all right great now let's + + + align:start position:0% +three of them all right great now let's +do the minuses + + align:start position:0% +do the minuses + + + align:start position:0% +do the minuses +there's the minus at 3 which is also the + + align:start position:0% +there's the minus at 3 which is also the + + + align:start position:0% +there's the minus at 3 which is also the +same as I minus at negative 7 minus at 3 + + align:start position:0% +same as I minus at negative 7 minus at 3 + + + align:start position:0% +same as I minus at negative 7 minus at 3 +is cosine 3 PI over 4 sine 3 PI over 4 + + align:start position:0% +is cosine 3 PI over 4 sine 3 PI over 4 + + + align:start position:0% +is cosine 3 PI over 4 sine 3 PI over 4 +which one is that + + align:start position:0% + + + + align:start position:0% + +so that's in a second ah yeah that's + + align:start position:0% +so that's in a second ah yeah that's + + + align:start position:0% +so that's in a second ah yeah that's +going to be the second quadrant we're + + align:start position:0% +going to be the second quadrant we're + + + align:start position:0% +going to be the second quadrant we're +going to have the cosine is going to be + + align:start position:0% +going to have the cosine is going to be + + + align:start position:0% +going to have the cosine is going to be +negative but the sine is going to be + + align:start position:0% +negative but the sine is going to be + + + align:start position:0% +negative but the sine is going to be +positive and so we get three points here + + align:start position:0% +positive and so we get three points here + + + align:start position:0% +positive and so we get three points here +and as you may predicted the other one + + align:start position:0% +and as you may predicted the other one + + + align:start position:0% +and as you may predicted the other one +the 5 PI over 4 is in the third quadrant + + align:start position:0% +the 5 PI over 4 is in the third quadrant + + + align:start position:0% +the 5 PI over 4 is in the third quadrant +we get three points here why are the + + align:start position:0% +we get three points here why are the + + + align:start position:0% +we get three points here why are the +support vectors + + align:start position:0% + + + + align:start position:0% + +but I understand where you're getting + + align:start position:0% +but I understand where you're getting + + + align:start position:0% +but I understand where you're getting +three of these of plus the person's + + align:start position:0% + + + + align:start position:0% + +already lonely to keep ah there's two + + align:start position:0% +already lonely to keep ah there's two + + + align:start position:0% +already lonely to keep ah there's two +negatives here and there's two natives + + align:start position:0% +negatives here and there's two natives + + + align:start position:0% +negatives here and there's two natives +here good cop doesn't change the problem + + align:start position:0% +here good cop doesn't change the problem + + + align:start position:0% +here good cop doesn't change the problem +in fact if we just grapple points there + + align:start position:0% +in fact if we just grapple points there + + + align:start position:0% +in fact if we just grapple points there +might have been more but there's a very + + align:start position:0% +might have been more but there's a very + + + align:start position:0% +might have been more but there's a very +subtle and important distinction there + + align:start position:0% +subtle and important distinction there + + + align:start position:0% +subtle and important distinction there +are two negatives but otherwise yeah + + align:start position:0% +are two negatives but otherwise yeah + + + align:start position:0% +are two negatives but otherwise yeah +these are grasped correctly does anyone + + align:start position:0% +these are grasped correctly does anyone + + + align:start position:0% +these are grasped correctly does anyone +see where the support vectors are some + + align:start position:0% +see where the support vectors are some + + + align:start position:0% +see where the support vectors are some +popular minus and plus will try to do + + align:start position:0% +popular minus and plus will try to do + + + align:start position:0% +popular minus and plus will try to do +the perpendicular bisector let's see it + + align:start position:0% + + + + align:start position:0% + +that works but guess what these guys are + + align:start position:0% +that works but guess what these guys are + + + align:start position:0% +that works but guess what these guys are +on the same line so we'd better circle + + align:start position:0% +on the same line so we'd better circle + + + align:start position:0% +on the same line so we'd better circle +them so it's actually the question is + + align:start position:0% +them so it's actually the question is + + + align:start position:0% +them so it's actually the question is +what isn't a support vector only this + + align:start position:0% +what isn't a support vector only this + + + align:start position:0% +what isn't a support vector only this +only those big question this is one + + align:start position:0% +only those big question this is one + + + align:start position:0% +only those big question this is one +affection I mean you just proved that + + align:start position:0% +affection I mean you just proved that + + + align:start position:0% +affection I mean you just proved that +actually just show that those land on + + align:start position:0% +actually just show that those land on + + + align:start position:0% +actually just show that those land on +the same line so you really need like + + align:start position:0% +the same line so you really need like + + + align:start position:0% +the same line so you really need like +the cosine term and a side + + align:start position:0% +the cosine term and a side + + + align:start position:0% +the cosine term and a side +just the cosine alright classic is so + + align:start position:0% +just the cosine alright classic is so + + + align:start position:0% +just the cosine alright classic is so +then we've done this in one dimension + + align:start position:0% +then we've done this in one dimension + + + align:start position:0% +then we've done this in one dimension +all we do is do only the cosine so if we + + align:start position:0% +all we do is do only the cosine so if we + + + align:start position:0% +all we do is do only the cosine so if we +did only the cosine then they would have + + align:start position:0% +did only the cosine then they would have + + + align:start position:0% +did only the cosine then they would have +still been divided easily divisible the + + align:start position:0% +still been divided easily divisible the + + + align:start position:0% +still been divided easily divisible the +answer is absolutely we could have + + align:start position:0% +answer is absolutely we could have + + + align:start position:0% +answer is absolutely we could have +however the question did not because + + align:start position:0% +however the question did not because + + + align:start position:0% +however the question did not because +Susan Q random student decided to do + + align:start position:0% +Susan Q random student decided to do + + + align:start position:0% +Susan Q random student decided to do +cosine inside but yes if we had said you + + align:start position:0% +cosine inside but yes if we had said you + + + align:start position:0% +cosine inside but yes if we had said you +654 student find a fine that will work + + align:start position:0% +654 student find a fine that will work + + + align:start position:0% +654 student find a fine that will work +for this you could have found a Phi that + + align:start position:0% +for this you could have found a Phi that + + + align:start position:0% +for this you could have found a Phi that +was just cosine that would be easier + + align:start position:0% +was just cosine that would be easier + + + align:start position:0% +was just cosine that would be easier +however it's important to be able to + + align:start position:0% +however it's important to be able to + + + align:start position:0% +however it's important to be able to +work with what somebody else gives you + + align:start position:0% +work with what somebody else gives you + + + align:start position:0% +work with what somebody else gives you +in this case they gave you they give you + + align:start position:0% +in this case they gave you they give you + + + align:start position:0% +in this case they gave you they give you +that transformation which yeah was a + + align:start position:0% +that transformation which yeah was a + + + align:start position:0% +that transformation which yeah was a +wasteful with an extra dimension you + + align:start position:0% +wasteful with an extra dimension you + + + align:start position:0% +wasteful with an extra dimension you +didn't need the sine because you didn't + + align:start position:0% +didn't need the sine because you didn't + + + align:start position:0% +didn't need the sine because you didn't +need the y-axis really here you just + + align:start position:0% +need the y-axis really here you just + + + align:start position:0% +need the y-axis really here you just +needed the X does everyone see this how + + align:start position:0% +needed the X does everyone see this how + + + align:start position:0% +needed the X does everyone see this how +this works can maybe transform + + align:start position:0% +this works can maybe transform + + + align:start position:0% +this works can maybe transform +dimensions the main hardest part is + + align:start position:0% +dimensions the main hardest part is + + + align:start position:0% +dimensions the main hardest part is +they'll usually give you a K and ask for + + align:start position:0% +they'll usually give you a K and ask for + + + align:start position:0% +they'll usually give you a K and ask for +a fire or give you a fire ask for a K + + align:start position:0% +a fire or give you a fire ask for a K + + + align:start position:0% +a fire or give you a fire ask for a K +it's not too bad just remember if they + + align:start position:0% +it's not too bad just remember if they + + + align:start position:0% +it's not too bad just remember if they +give you a Phi do a dot product with it + + align:start position:0% +give you a Phi do a dot product with it + + + align:start position:0% +give you a Phi do a dot product with it +and if they give you a fire that's just + + align:start position:0% +and if they give you a fire that's just + + + align:start position:0% +and if they give you a fire that's just +one component dot product of one + + align:start position:0% +one component dot product of one + + + align:start position:0% +one component dot product of one +component just multiplying it together + + align:start position:0% +component just multiplying it together + + + align:start position:0% +component just multiplying it together +easy enough so they give you a K treat + + align:start position:0% +easy enough so they give you a K treat + + + align:start position:0% +easy enough so they give you a K treat +it as a dot product and try to + + align:start position:0% +it as a dot product and try to + + + align:start position:0% +it as a dot product and try to +reverse-engineer it's usually something + + align:start position:0% +reverse-engineer it's usually something + + + align:start position:0% +reverse-engineer it's usually something +like this that's easy to + + align:start position:0% +like this that's easy to + + + align:start position:0% +like this that's easy to +reverse-engineer I really haven't seen + + align:start position:0% +reverse-engineer I really haven't seen + + + align:start position:0% +reverse-engineer I really haven't seen +it where it's not so it may look it + + align:start position:0% +it where it's not so it may look it + + + align:start position:0% +it where it's not so it may look it +often looks like the scariest problem + + align:start position:0% +often looks like the scariest problem + + + align:start position:0% +often looks like the scariest problem +but it's usually not too bad to go + + align:start position:0% +but it's usually not too bad to go + + + align:start position:0% +but it's usually not too bad to go +between five and KS does anyone have any + + align:start position:0% +between five and KS does anyone have any + + + align:start position:0% +between five and KS does anyone have any +questions on anything that we did on + + align:start position:0% +questions on anything that we did on + + + align:start position:0% +questions on anything that we did on +spectrum change + + align:start position:0% + + + + align:start position:0% + +but what is some what's the intuition + + align:start position:0% +but what is some what's the intuition + + + align:start position:0% +but what is some what's the intuition +behind the building like we solve it and + + align:start position:0% +behind the building like we solve it and + + + align:start position:0% +behind the building like we solve it and +figure out numbers integrations what is + + align:start position:0% +figure out numbers integrations what is + + + align:start position:0% +figure out numbers integrations what is +it but what is intuition what is w w is + + align:start position:0% +it but what is intuition what is w w is + + + align:start position:0% +it but what is intuition what is w w is +the dividing line it's the drop-dead + + align:start position:0% +the dividing line it's the drop-dead + + + align:start position:0% +the dividing line it's the drop-dead +dividing line when I say the drop-dead + + align:start position:0% +dividing line when I say the drop-dead + + + align:start position:0% +dividing line when I say the drop-dead +dividing line you like those big bold + + align:start position:0% +dividing line you like those big bold + + + align:start position:0% +dividing line you like those big bold +solid lines over there those are you're + + align:start position:0% +solid lines over there those are you're + + + align:start position:0% +solid lines over there those are you're +pretty certain lines everything passed + + align:start position:0% +pretty certain lines everything passed + + + align:start position:0% +pretty certain lines everything passed +that was a minus and you're doing your + + align:start position:0% +that was a minus and you're doing your + + + align:start position:0% +that was a minus and you're doing your +training is that everything has to plus + + align:start position:0% +training is that everything has to plus + + + align:start position:0% +training is that everything has to plus +the big bold line there was a plus in + + align:start position:0% +the big bold line there was a plus in + + + align:start position:0% +the big bold line there was a plus in +your training separate the dotted line + + align:start position:0% +your training separate the dotted line + + + align:start position:0% +your training separate the dotted line +is the one you're really going to use in + + align:start position:0% +is the one you're really going to use in + + + align:start position:0% +is the one you're really going to use in +the test data in the test data when push + + align:start position:0% +the test data in the test data when push + + + align:start position:0% +the test data in the test data when push +comes to shove you might get something + + align:start position:0% +comes to shove you might get something + + + align:start position:0% +comes to shove you might get something +that's inside of that gutter and if it's + + align:start position:0% +that's inside of that gutter and if it's + + + align:start position:0% +that's inside of that gutter and if it's +on the say of that one up there it's on + + align:start position:0% +on the say of that one up there it's on + + + align:start position:0% +on the say of that one up there it's on +the up left side that dotted line you're + + align:start position:0% +the up left side that dotted line you're + + + align:start position:0% +the up left side that dotted line you're +going to call it a plus so that dotted + + align:start position:0% +going to call it a plus so that dotted + + + align:start position:0% +going to call it a plus so that dotted +line is your decision boundary and that + + align:start position:0% +line is your decision boundary and that + + + align:start position:0% +line is your decision boundary and that +is that is basically the idea and in + + align:start position:0% +is that is basically the idea and in + + + align:start position:0% +is that is basically the idea and in +fact the way that the algorithm would do + + align:start position:0% +fact the way that the algorithm would do + + + align:start position:0% +fact the way that the algorithm would do +it on the computer is it would contract + + align:start position:0% +it on the computer is it would contract + + + align:start position:0% +it on the computer is it would contract +the optimize the Alfa's which messes + + align:start position:0% +the optimize the Alfa's which messes + + + align:start position:0% +the optimize the Alfa's which messes +around with the dotted line and by + + align:start position:0% +around with the dotted line and by + + + align:start position:0% +around with the dotted line and by +quadratically i'll math-amazing the out + + align:start position:0% +quadratically i'll math-amazing the out + + + align:start position:0% +quadratically i'll math-amazing the out +those alphas you see how the alphas add + + align:start position:0% +those alphas you see how the alphas add + + + align:start position:0% +those alphas you see how the alphas add +up to a w it just checks it around and + + align:start position:0% +up to a w it just checks it around and + + + align:start position:0% +up to a w it just checks it around and +eventually it finds Oh making the alpha + + align:start position:0% +eventually it finds Oh making the alpha + + + align:start position:0% +eventually it finds Oh making the alpha +of this one zero makes that that makes + + align:start position:0% +of this one zero makes that that makes + + + align:start position:0% +of this one zero makes that that makes +it a better optimization you're trying + + align:start position:0% +it a better optimization you're trying + + + align:start position:0% +it a better optimization you're trying +to get the widest possible road it would + + align:start position:0% +to get the widest possible road it would + + + align:start position:0% +to get the widest possible road it would +eventually come out to this this is + + align:start position:0% +eventually come out to this this is + + + align:start position:0% +eventually come out to this this is +trivial for a human to eyeball but some + + align:start position:0% +trivial for a human to eyeball but some + + + align:start position:0% +trivial for a human to eyeball but some +real problems with two hundred data + + align:start position:0% +real problems with two hundred data + + + align:start position:0% +real problems with two hundred data +points that have to get one or two of + + align:start position:0% +points that have to get one or two of + + + align:start position:0% +points that have to get one or two of +them wrong classified and so you may be + + align:start position:0% +them wrong classified and so you may be + + + align:start position:0% +them wrong classified and so you may be +using a quadratic kernel or something + + align:start position:0% +using a quadratic kernel or something + + + align:start position:0% +using a quadratic kernel or something +like that + + align:start position:0% +like that + + + align:start position:0% +like that +you can't do that you just can't well + + align:start position:0% +you can't do that you just can't well + + + align:start position:0% +you can't do that you just can't well +maybe you can in which case you should + + align:start position:0% +maybe you can in which case you should + + + align:start position:0% +maybe you can in which case you should +be getting a MacArthur Fellowship or + + align:start position:0% +be getting a MacArthur Fellowship or + + + align:start position:0% +be getting a MacArthur Fellowship or +something like that but the computer + + align:start position:0% +something like that but the computer + + + align:start position:0% +something like that but the computer +can't and the basic idea is when it + + align:start position:0% +can't and the basic idea is when it + + + align:start position:0% +can't and the basic idea is when it +comes down to it it figures out the + + align:start position:0% +comes down to it it figures out the + + + align:start position:0% +comes down to it it figures out the +Alpha is to give it the bet the best W + + align:start position:0% +Alpha is to give it the bet the best W + + + align:start position:0% +Alpha is to give it the bet the best W +for widest road in the W is your + + align:start position:0% +for widest road in the W is your + + + align:start position:0% +for widest road in the W is your +decision about it good question any + + align:start position:0% +decision about it good question any + + + align:start position:0% +decision about it good question any +other questions about our old friend SVM + + align:start position:0% +other questions about our old friend SVM + + + align:start position:0% +other questions about our old friend SVM +I have a question for you um after + + align:start position:0% +I have a question for you um after + + + align:start position:0% +I have a question for you um after +seeing this and let's pretend that they + + align:start position:0% +seeing this and let's pretend that they + + + align:start position:0% +seeing this and let's pretend that they +only ask you to solve for WS B's you + + align:start position:0% +only ask you to solve for WS B's you + + + align:start position:0% +only ask you to solve for WS B's you +know these kind of criminals and Pfizer + + align:start position:0% +know these kind of criminals and Pfizer + + + align:start position:0% +know these kind of criminals and Pfizer +typical things how many people now think + + align:start position:0% +typical things how many people now think + + + align:start position:0% +typical things how many people now think +that you can go through and work an SVM + + align:start position:0% +that you can go through and work an SVM + + + align:start position:0% +that you can go through and work an SVM +problem alright we've got we've got a + + align:start position:0% +problem alright we've got we've got a + + + align:start position:0% +problem alright we've got we've got a +few we + + align:start position:0% +few we + + + align:start position:0% +few we +a happy few band of brothers maybe eight + + align:start position:0% +a happy few band of brothers maybe eight + + + align:start position:0% +a happy few band of brothers maybe eight +people raised their hand there that's + + align:start position:0% +people raised their hand there that's + + + align:start position:0% +people raised their hand there that's +good + + align:start position:0% +good + + + align:start position:0% +good +how many people know what a support + + align:start position:0% +how many people know what a support + + + align:start position:0% +how many people know what a support +vector is now that's really good because + + align:start position:0% +vector is now that's really good because + + + align:start position:0% +vector is now that's really good because +that if that's all you learn from + + align:start position:0% +that if that's all you learn from + + + align:start position:0% +that if that's all you learn from +today's minor sensation is still good + + align:start position:0% +today's minor sensation is still good + + + align:start position:0% +today's minor sensation is still good +it really is I'm telling you I had to + + align:start position:0% +it really is I'm telling you I had to + + + align:start position:0% +it really is I'm telling you I had to +take two classes on this and then ta it + + align:start position:0% +take two classes on this and then ta it + + + align:start position:0% +take two classes on this and then ta it +before I really really understood it so + + align:start position:0% +before I really really understood it so + + + align:start position:0% +before I really really understood it so +you guys are ahead of me all right take + + align:start position:0% +you guys are ahead of me all right take + + + align:start position:0% +you guys are ahead of me all right take +care have a great weekend and we'll see + + align:start position:0% +care have a great weekend and we'll see + + + align:start position:0% +care have a great weekend and we'll see +you for boosting and vampires next week \ No newline at end of file diff --git a/6uLKZSoHnrc.txt b/6uLKZSoHnrc.txt new file mode 100644 index 0000000000000000000000000000000000000000..735e59356fdc01ce48470e6259f0559b8bc6bc85 --- /dev/null +++ b/6uLKZSoHnrc.txt @@ -0,0 +1,1977 @@ +The following content is +provided under a Creative + +Commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high-quality educational +resources for free. + +To make a donation or view +additional materials from + +hundreds of MIT courses, visit +MIT OpenCourseWare at + +ocw.mit.edu. + +PROFESSOR NELSON: Well, so last +time we did a little bit + +more work on thermodynamic +cycles, and basically went + +around a cycle and looked at +some state functions, delta u + +and delta H. Saw that around +a closed cycle those zero + +because they're state +functions. + +So if you start and end at the +same place, they've got end at + +the same place that +they started. + +There's no change in them, and +then we also looked at some at + +non-state functions, work and +heat, and saw that those + +aren't zero going +around a cycle. + +Of course you can do work in a +cyclic process, and heat can + +be exchanged with the +environment at the same time. + +So we calculated those +values too. + +And we also looked at this other +funny function that's + +our special function. + +We looked at this integral dq +over T. It's so special that + +we called this derivative dS, +and saw that at least for the + +cycle we looked at, it +also behaved as a + +state function behaves. + +That is, going around the cycle, +it had no net change, + +and we'll see this come +back later on. + +Then we went on to look at +thermochemistry, and that's + +what I want to continue today. + +So really, the main result that +we saw last time is that + +we can describe the enthalpy +of reaction, so if we have + +reactants going to products, and +we'd like to know our heat + +of reaction or enthalpy of +reaction, remember it's a + +constant pressure as we're +considering it, so it's + +equivalent to heat of reaction, +than the way we can + +do this is construct a cycle +where we're going to express + +these in terms of their +constituent elements. + +We're going to all the way +back to the atoms. + +Right, so if we have the +elements in their standard + +states, that is their most +stable forms at room + +temperature and pressure, then +what we're really doing is + +we're saying let's take the +reactants and let's pull them + +all apart into their +separate elements, + +they're separate atoms. + +And then put them back together +this way, and we'll + +calculate the enthalpy +of this process, the + +enthalpy of this process. + +It's a cycle, so that'll +give us the enthalpy of + +reaction, all right? + +So this delta H is our sum for +delta H of formation for the + +reactants, right. + +And this is our sum of +the quantity for + +the products, right. + +And in this way, then we can +express our delta H of + +reaction is just going to be +given a sum of the heats of + +formation or the difference +between the heats of formation + +of the products and the +reactants, right? + +Now, of course, we have to +weight this by the number of + +moles of each reactant +to each product + +involved in the reaction. + +So to write this a little more +carefully, it's, you want to + +write the sum over i of nu i +delta H naught of formation of + +i summed over the products. + +This is per mole minus sum over +i, nu i here over the + +reactants in the +same quantity. + +Delta H per mole f i, right? + +So in other words, were taking +each of the products and we're + +going to weight them by their +stoichiomeric coefficients, + +and we're going to have in this +delta H of reaction their + +heats of formation, and then +we're going to have the + +negative heats of formation of +the reactants, because that's + +being subtracted, okay? + +So, just to go through a basic +example, let's just look at + +the burning of methane. + +So we've got methane gas, +combining with oxygen gas, so + +you have carbon dioxide gas and +liquid water, and we'll + +consider the whole thing +at room temperature + +and pressure, right. + +So let's just undertake +this set of processes. + +Let's decompose these +to the elements. + +So in other words, our methane +gas, we're going to write the + +chemical equilibrium between +this and the solid carbon. + +That is to say let's specify +graphite, it's not diamond, + +right, graphite is the stable +form of carbon at room + +temperature and pressure. + +And then, hydrogen gas two +moles of hydrogen gas and + +we're going to have a delta +H of formation. + +This is for CH4 in the +gas phase, right? + +And then over here, we have our +oxygen but 2 O2 gas going + +to, well 2 O2 gas -- the point +is oxygen already is in it's + +stable form at room temperature + +and pressure, right? + +That is the elemental form of +oxygen, of course, is as + +oxygen molecules in the gas so +there's no delta H formation + +for oxygen. + +The gas is zero, right. + +And then second phase of this, +now we're going to take the + +elements that we've produced, +and we're going to put them + +back to make products, right? + +So there we've got carbon as +graphite, and a solid plus an + +oxygen gas goes to make +CO2 gas, right. + +And we've got our positive +delta H of formation + +associated with that. + +And finally we've got hydrogen +gas plus oxygen gas giving us + +two water molecules and this +is in the liquid phase, and + +there's some delta heat of +formation associated with + +that, okay. + +So there is our set of +individual processes that's + +going to constitute +our cycle, right. + +If we take the combination of +all those, which is to say we + +just take both steps in this +cycle, then we'll have our net + +reaction, which is to say +we'll have this, right. + +So what that says is our heat +of reaction is our heat of + +formation per mole of +CO2 gas, right. + +Plus 2 times the heat of +reaction or heat of formation + +per mole of liquid water minus +heat of formation per mole of + +methane, right. + +And things we can +easily look up. + +So in a simple way, we can +determine, we can calculate + +what the heat of +reaction is for + +something like this, right. + +And you'll see in the back +of your book, you'll see + +moderately extensive tables of +heats of formation, and if you + +go online you'll see, you can +find extremely extensive + +tabulated values of heats of +formation, that have been + +measured for an enormous +number of compounds. + +And from that, then you can look +at enthalpies of reaction + +for countless numbers +of reactions, right. + +So by using the tabulated data, +we can really determined + +heats of formation for most +reactions that you might + +contemplate, OK? + +Of course, the cyclic steps that +we've taken to do this + +apply not just for breaking +down reactants and product + +into the elements in their +standards states, but of + +course we could also look at +whole sets of reactions and + +write cycles as well, right. + +So for example, if we wanted +to look at the reaction of + +something like carbon graphite +plus oxygen gas to make carbon + +monoxide gas, well normally +this isn't the way the + +reaction would work. + +Normally if you just tried to +make this happen what you + +would wind up with the +CO2, not CO, right. + +But one way to approach this +is you could look at the + +individual reactions of going, +you could go to CO2 and then + +you can go with CO2 and oxygen +and combine, or combine CO and + +oxygen to get CO2, right? + +So normally, CO2 is formed, but +you could calculate the + +heat of reaction. + +Of course you could go back to +the elements, but you can also + +say well, let's just take a +known heat of reaction for, or + +heat of formation for CO2, and +then also combine that with + +the heat of reaction for CO plus +oxygen forming CO2 and + +determine this that way, all +right, OK, so once you have + +done this, once we've got the +heat of reaction then there + +are a few simple results +that are useful. + +One is we know immediately +whether when we run a reaction + +heat is going to be released +in the process out to the + +environment, or whether +heat is going to + +be taken in, right. + +So, and of course if you ever +used a hot pack or a chemical + +hot pack or cold pack, you've +seen examples of the two of + +those, where the constituents +are selected to give you + +either heat released or +heat taken up, right. + +So in particular delta H of +reaction less than zero, that + +means a negative amount of heat, +which means that heat is + +released, right. + +Yes, that is it's exothermic. + +Positive enthalpy of reaction, +which is to say a heat of + +reaction is positive. + +Remember the way we define heat +is positive it means that + +there is heat that is coming +from the environment into the + +system, right. + +In other words heat is absorbed +or taken up by the + +reacting system. + +That's endothermic, okay. + +All right, one more important +aspect of this that we need to + +be able to deal with, and that +is the heats of formation that + +you'll find tabulated typically +are going to be + +given for room temperature +and pressure. + +And it's very common that you +might want to know the + +thermodynamic condition for +reactions, especially at other + +temperatures, very common, +of course. + +And it's not hard to see how the +heat of reaction at room + +temperature can be related to +they heat of reaction at other + +temperatures. + +So let's just look at that. + +So remember your fundamental +relation, dH, if you write + +that as a function of +temperature and pressure, + +partial of H with respect to T, +constant pressure, dT, plus + +partial of H with respect to p +at constant temperature, dp. + +But if we're working +at constant + +pressure then dp is zero. + +So we just got the derivative +with respect to temperature. + +That's our heat capacity, +right, Cp. + +And we may have tabulated values +of Cp for an enormous + +number of materials. + +So now, if we look at the +temperature dependence of + +delta H for reaction, really +what we're going to need to do + +is look at how that heat +capacity changes going from + +reactants to products, right? + +So in other words, d delta H of +reaction, with respect to + +temperature. + +That's what we want to +find out, right? + +So how does delta H change if +we change the temperature? + +Well, it's just given by Cp dT +for the reactants and the + +products, right? + +For the products minus the +reaction, that is it's delta + +Cp, we need the sum +over the products. + +Nu i, Cp i minus same +sum over reactants, + +i, nu i Cp i, right. + +Similar to what we saw before. + +Now we need to integrate, +right. + +So if we integrate between some +pair of temperatures, T1 + +and T2, we do this and we have +this quantity, d delta H of + +reaction with respect to +temperature, dT, all this is + +at constant pressure, right. + +Let's just be careful +to specify that. + +Well, so of course, this is then +just delta H of reaction + +at T2 minus delta H +of reaction at T1. + +This is looking good. + +This is what we want to get, +is our heat of reaction at + +some new temperature T2. + +If we already know it at some +initial temperature, usually + +room temperature, T1. + +And it's just given by the +integral from T1 to T2 of + +delta Cp dT. + +Now in general, this is as far +as we can go, but at least if + +the temperature change isn't +too big, for most materials + +that heat capacities doesn't +depend very strongly on + +temperature, right. + +If you take some material, and +you measure its heat capacity, + +right, how much heat do I have +to put into it in order to + +change its temperature +by a degree, right. + +And I make that measurement +at room temperature. + +And then maybe I raise the +temperature to whatever, room + +temperature, maybe 20 degrees +hotter than room temperature. + +And I again say OK, now how much +heat do I need to raise + +this thing's temperature +by 1 degree? + +The amount of heat I need to put +in to do that is not very + +different from what it was at +room temperature right. + +In other words the +heat capacity + +didn't change very much. + +So, the result of that is +that at least for modest + +temperature excursions, it may +be the case that we can + +simplify this and simply say +it's just the difference in + +heat capacities times the +temperature change. + +Again, we can't always be +assured of that, but it's + +often the case. + +Any questions on any +of this so far? + +OK, now what I want to do is +just describe a little bit of + +how do you measure all +this stuff, right? + +So what we've done so far is +just lay out in principle how + +we should describe heats of +reaction, and of course + +assuming that we've got +everything in tables we can + +always look them up, but +sometimes you want to make new + +compounds, right. + +Sometimes you'd like to know +what the energetics are + +involved there, right, and so +it's useful to be able to + +actually measure something. + +So how do we do It? + +This is what's called +calorimetry. + +So we're going to make +measurements to determine heat + +of reaction values. + +Actually, calorimetry is used +for all sorts of things. + +It can be used to determine, for +example, the energetics of + +phase transitions. + +Maybe you're not looking at a +reaction, but you've got some + +new compound, and you're looking +at it go from liquid + +to solid or to gas. + +And you can see what the heat +involved in a process like + +that is as well. + +So what happens? + +Well, the objective in the case +of a reaction, we have + +reactants at some temperature +going to products at that + +temperature, and that is our +heat of reaction at that + +temperature. + +That's how it's defined, +right, at constant + +temperature. + +OK? + +What do we actually measure? + +Well, what we can really do is +we can put the reactants in + +some container, put the whole +thing in an insulated place, + +you know, hold things in +a big insulated box. + +Run the reaction. + +Maybe it produces heat. + +If it does, then the whole thing +will heat up, right? + +The stuff that's inside the +reacting volume, and + +whatever's right around it there +inside the big box, it's + +all going to heat up. + +So I'll start at some initial +temperature, T1. + +I won't end up at the +same temperature. + +It'll be hotter. + +How much hotter? + +Well, that depends on how +much heat was produced. + +So in principle, if I measure +how much hotter, I can + +determine how much heat was +produced, and from that, I + +should be able to calculate +delta H at T1. + +So let's think about how +that's really working. + +I've really got reactants at T1, +plus a calorimeter at T1, + +and I'm going to end up with +products -- well let's let me + +just write that's over. + +In fact, let's start by just +putting a little sketch of the + +whole thing up. + +So here's my reacting stuff, +maybe it's a liquid. + +It's going to take +place in there. + +It's going to be a constant +pressure, it might be open to + +the air, or even if it isn't, +there might be plenty of room, + +and it's a liquid anyway, so +the pressure isn't going to + +change significantly. + +I want to measure +the temperature. + +And the whole thing is +insulated right. + +I don't want to have to deal +with heat escaping to the + +outside environment in a way +that might be difficult or + +complicated to measure +or calculate. + +OK, so this, what I've sketched +here would be a + +constant pressure calorimeter. + +There's a reaction. + +Normally this is used for a +reaction in the condensed + +phases and liquid usually. + +So this is a constant pressure +calorimeter. + +It's set up to be + +well-insulated so it's adiabatic. + +That's the set up. + +We're going to run the +reactants, the reaction. + +The reactants are going +to turn into products. + +Let's look at what happens. + +So what happens is my +reactants at T1 plus + +calorimeter at T1 turn into +products at T2 plus my + +calorimeter at T2, right. + +That's my process. + +That's what really happens. + +Now that, the enthalpy of that +process isn't what I want, + +right, because the temperature +has changed, also the + +calorimeter is heated up. + +So I need to relate this +to what I do want. + +Let's label this one. + +It is adiabatic. + +It is taking place inside this +thing, and it's a constant + +pressure, and we'll do +it reversibly, right. + +So that's what we've got. + +Now, we can always take these +things the products and the + +calorimeter at temperature T2 +and cool them or warm them to + +get to products plus calorimeter +at T1, right. + +Let's label that two. + +It's still at constant +pressure. + +It's reversible. + +It's a temperature change. + +Now to make that happen, it's +not adiabatic, right. + +If I wanted to do that, I'd +need a heating element or + +something to cool, so I could +make that temperature change + +happen, right. + +Well, so now I can complete +the cycle. + +I've got reactants and +calorimeter at T1. + +Fewer products and calorimeter +at T1, right. + +Calorimeter doesn't change +in this process. + +So here I've got some delta H +associated with changing the + +temperature. + +This delta H though, this +is what I want. + +This is delta H of reaction +at T1, right? + +It's isothermal, constant +pressure, reversible. + +Just what I want. + +That's how I've defined +delta H of reaction. + +This is what I'm after. + +All right, so now let's see how +we execute it, and do the + +calculations that allow +us to calculate this. + +So, one, what's delta +H in step one? + +Yes, exactly, it's adiabatic, +right constant pressure. + +it's zero. + +Delta H1 is zero, right. + +What we're really going to do in +practice is we're going to + +measure, we're going to use our +thermometer and say great, + +how much did the temperature +change, right. + +So now, then we're going to use +what we're going to learn + +from step two in order to +calculate this part, what we + +could call step three. + +OK, so two, that's +the crucial part. + +It's constant pressure. + +It's just given by the +corresponding heat, and it's + +just a temperature +change, right. + +So we know how to do this, +integral from well it's T1 to + +T2, depending on which way +we go of Cp for the + +whole system dT. + +OK? + +It's just how much heat is +involved when we change the + +temperature. + +Now, the products have some heat +capacity associated with + +them right, it takes a certain +amount of heat if we make + +their temperature change, to +either put it in or take it + +away, depending on which +direction the + +temperature is changing. + +Same with the calorimeter, OK. + +In actual practice though, the +calorimeter, is going to be + +this big hunk of metal, and +really what's going to, + +there's going to be some stuff +in here, right, they'll be a + +fluid, it will usually +be some sort of oil. + +There's a pretty big +thermal mass. + +Now we run the reaction +and it produces heat. + +Most of the heat is going to +warm up or cool off all that + +oil and stuff. + +There's a moderate amount +of material + +in the actual reaction. + +You want to design the +calorimeter to fulfill that + +condition, + +Of course, you can't make it +so enormous that even for, + +that for any ordinary reaction +there's not even a measurable + +temperature change, right, +because if you have your + +enough oil to fill up this room, +it would take a huge + +amount of heat to change it by +even a tiny, it's temperature + +but even a tiny amount. + +So the calorimeter is designed +sort of to scale to match the + +maybe the ordinary volume of +reactants that you'll put in + +there, such that, pretty much +all the heat's just going to + +heat up the calorimeter, and +there's only a small amount + +that's going toward heating +up the products, right. + +So in general, or at least +usually it'll be the case, + +that this is approximately equal +to integral from T1 to + +T2 Cp of just the +calorimeter dT. + +And that generally is just given +by the heat capacity the + +calorimeter times +delta T, right.. + +Because the heat capacity of the +calorimeter just like this + +thing is not strongly +temperature dependent, OK. + +So the point is we can calculate +delta H associated + +with this process pretty +readily, OK. + +That leaves three, right. + +But delta H for step three must +just be the opposite of + +this delta H because this was +zero and we know that were + +going around a cycle, right. + +And that's our heat +of reaction. + +So we're going to be able +to do this, right? + +OK, now this is one way to +do calorimetry, and it's + +practical as long as all the +materials are in condensed + +phases, solids and liquids. + +If gases are involved it can +work, but it can be tricky to + +keep the pressure constant, +right, because that means that + +now the moles of gas might be +changing, and that means in + +some way the volume has +to be adjustable. + +You'd need some sort of balloon +or membrane that will + +allow that to happen. + +Could be done, but easier is to +just do the whole thing at + +constant volume, right, and just +run the reaction that way + +and redo the calculation to be +a constant volume rather than + +constant pressure calorimeter, +right. + +And it's not hard to do that. + +So let's just look at what +happens in that case. + +It's almost the same. + +So let's see, just to finish the +job here though, all this + +says is delta H of reaction is +just negative Cp for the + +calorimeter times delta T, all +right. so that's what we think + +we know in constant pressure +calorimetry. + +Yes, and if we have gases +involved, it's pretty similar, + +but now what will have is +something like this. + +We'll have a reaction vessel +that's sealed, + +it's constant volume. + +That'll be inside +our calorimeter. + +It's insulated, and there's +still a thermometer, so we can + +measure the temperature. + +So this is still adiabatic. + +It's insulated, but now it's +constant volume, OK. + +Now, you know with constant +volume, now it's not going to + +be delta H that's +straightforward to measure, + +it's going to be dealt +u, all right. + +But it's going to be almost +the same, right? + +So let's just think about +what happens here. + +Now it's the cycle that +we've got will still + +basically look the same. + +That is its reactants at T1 plus +calorimeter at T1, going + +to products at T2 plus +calorimeter at T2, right? + +And it's still adiabatic, but +now it's constant volume. + +And it's also reversal right. + +So this is our process one. + +Now, process two, we're going +to end up here with our + +products, again at T1 plus our +calorimeter at T1, right. + +So now we have a +constant volume + +reversible temperature change. + +And so this part now isn't +exactly what we want to + +determine delta H, because it's +a isothermal constant + +volume, reversible products or +reversible process that takes + +a reactant to T1 to +a product of T1. + +What these are going to give +us are delta u values. + +This'll give us delta u of +reaction, right, T1, right. + +It's a constant volume. + +All right, so in the end, we're +going to determine delta + +u here, and then in the end, +we're going to have to relate + +that to delta H, but that's +straight forward enough to do. + +So let's look at how we'll +analyze what happens. + +So one adiabatic, constant +volume process, right. + +What's zero in that case? + +In this case delta +H was zero in the + +constant pressure example. + +Now we've got a constant +volume process. + +What's zero? + +It's u, because u is to q plus +w right, heat and work, but + +it's adiabatic. + +So there's no heat, exchange +with the environment, and it's + +constant volume, so there's +no p dV work, right. + +So q is zero adiabatic. + +Work is zero. + +Delta u1 is zero. + +And again just in the constant +pressure case, what happens + +that we're going to measure in +step one, which is to say in + +actually running the +reaction is the + +temperature's going to change. + +Right? + +The whole thing's going to come +to some new equilibrium + +temperature between the products +and the oil or + +whatever's around it, and we're +going to measure that. + +OK, two, now it's a temperature +change, right? + +We know how to calculate delta +u for a temperature change. + +It's very similar here, but +what's going to be different + +from the case with constant +pressure? + +There's a real important detail +that's different if you + +want to calculate what happens +at constant pressure when you + +change the temperature? + +What happens at constant +volume? + +Looking at this expression, +what's got to be different? + +Cv, right. + +We're not going to have the +constant pressure heat + +capacity, we're going to have +the constant volume heat + +capacity, right. + +So delta u for step two, that's +our q under constant + +volume conditions, integral +from T1 to T2 Cv for our + +whole system dT. + +Integral from T2 to T2, and now +I can separate again the + +calorimeter from the product, +and at least approximately, + +again, it'll be Cv for the +calorimeter dT, which is to + +say then it's Cv of +the calorimeter + +times delta T. Great. + +Three, well delta u1 was zero. + +Delta u2 was there Cv delta T, +so now all we need since the + +whole thing is going around in +a cycle, Since we know delta + +u3 must be negative delta u2, +and that is our delta u of + +reaction, right? + +So delta u of reaction is +approximately equal to + +negative Cv for the calorimeter +times delta T. So, + +this is what we're going to +measure, and this is what + +we're going to determine. + +And now we're almost done, +except what we really want is + +delta H and not delta +V, right. + +So now we're going to use the +fact that H is u plus pV. + +Delta H is delta u plus delta +pV, and now this is all at + +constant temperature +in the end, right? + +We've determined delta u for +some temperature T1, right. + +So what happens then +we're going to use + +the ideal gas law. + +So it's approximately delta +u plus delta nRT. + +That's a constant. + +That's a constant. + +So it's delta u plus RT, we can +say T1 is the temperature + +we've used here, delta +n of the gas. + +In other words, what matters +here in changing the pressure + +volume product? + +What matters is we turned some +reactants into some products. + +How many moles of gas are +there in each case, in + +reactants and products? + +If that changes, of course you +know that the pressure in + +there is going to change at +constant volume if the amount + +of gas in there is changing. + +And nothing else is going +to make a significant + +contribution to it, OK? + +So finally, then delta H of +reaction for our temperature + +T1 is approximately minus Cv of +the calorimeter times delta + +T plus R T1 delta n of gas. + +Change of the number of +moles of gas, right. + +We're going to measure that, +and now we're going to + +determine this. + +In practice, we'll already know +the heat capacity of our + +calorimeter, when we +buy it, right? + +So we don't really need to put +in a certain amount of heat + +and change the temperature +of the products and the + +calorimeter and so on. + +What we need to do is just +measure how much the + +temperature changed, OK. + +It's worth getting just sort of +roughly calibrated how big + +is this compared to the +rest of this stuff. + +That is, how different +is delta u from + +delta H, all right. + +And of course it's +straightforward to do this, + +and I've written this out in the +notes, so I won't re-write + +the numbers here. + +But I gave an example +looking at combining + +HCl and oxygen right. + +So 4 HCl plus oxygen gas. + +This two in the gas going to +water and the liquid, plus + +chlorine gas at room +temperature. + +Well, what you find out is delta +u of reaction is minus + +195 kilojoules for the +reaction as written. + +And it turns out, as written, if +you say OK, how much, what + +changed for the pV product? + +Well here we've got four moles +of gas, five moles of gas. + +Here just two, so we changed +the number of + +moles of gas by three. + +All right, how much did +it matter, right? + +Well it matters. + +It's measurable. + +So now delta H of reaction +turns out to be minus 202 + +kilojoules. + +So, you know, seven out of a +couple of a hundred, right, a + +few percent, kind of typical. + +In other words, if you look +at energetics of ordinary + +reactions where you're, you +know, you're making and + +breaking covalent bonds, there's +a fair amount of + +energy stored in those, right? + +The additional change due to +changing pressure volume is + +certainly measurable. + +You don't want to just ignore +it, but in cases like that, + +it's usually a small fraction +of the total. + +A few percent is +typical, okay. + +All right, let me just go +through one numerical example + +of a calorimetry calculation, +OK. + +I won't put all the numbers up +on the board because our time + +is running short, but I just +want to outline it. + +All I really want to do is +calibrate you a little bit for + +what happens with ordinary +calorimeter heat capacities + +that makes the calculation +turn out to be relatively + +easy, right. + +So let's just write it out. + +Let's take iron sulfide as a +solid, plus 11 halves oxygen + +gas to make iron oxide, +also a solid, plus + +sulphur dioxide gas. + +All right. + +We'll start at T1 +is 298 Kelvin. + +T2, maybe we don't know +it yet, right. + +OK, so we know how to calculate +what's going to + +happen, delta H and delta u, +because we can look up the + +heats of formation and +so forth of all + +the compounds, right. + +So if we do that, what we +discover is that delta H of + +formation whoops, something's +wrong here. + +This is sulphur -- what am I +doing, boy, S and it's a two, + +sorry, and the heat of formation +is minus 180 + +kilojoules per mole, that's +oxygen, it's zero. + +Boy, I'm, I don't know what is +about this reaction that's + +vexing me but it's not +that complicated. + +Here it's minus 824 kilojoules +per mole minus 297 kilojoules + +per mole, right. + +So that's our input +thermodynamic data. + +So first of all, let's just +do a heat of reaction + +calculation, right. + +Taking the product minus +the reaction, right. + +So it's minus 824 plus 4 +times minus 297 minus + +2 times minus 180. + +Right? + +In other words I've got the +stoichiometric coefficients in + +there and the values, and I'm +subtracting the reactants from + +products wind up with minus +1652 kilojoules per mole. + +Well, it depends on what we +write, what we consider mole, + +right, maybe I should just write +kilojoules as written. + +OK, I'm going to skip the delta +and get the change in + +moles of gas calculation. + +It's straightforward to do. + +What I really want to do is just +give an example of what + +happens when you throw the +thing, the material into a + +calorimeter and see how much +the temperature changes. + +So let's imagine we start with +0.1 moles of our iron sulfide, + +and then we have a +stoichiometric amount of + +oxygen, and the whole thing is +done in a constant volume + +calorimeter, and we +see what happens. + +Now the crucial element is what +is the heat capacity of + +the calorimeter, right? + +And it's, again it's a +macroscopic pretty big thing, + +so typical might be 10 +kilojoules per Kelvin, and + +that's pretty big, right? + +Noticed that's not +per mole, right. + +I mean the calorimeter is a big +thing filled the little + +oil or whatever is +inside it, right? + +And it's for that whole +unit that you've + +got some heat capacity. + +How much heat does it take the +warm the entire thing up or + +the insides of the thing +up by a degree? + +It's that number right. + +Ordinary heat capacities are +in Joule's per Kelvin mole, + +not kilojoules, right. + +And what that's telling you is +probably your reactants and + +products, so the amount of +heat that's involved in + +changing the air temperature +is going to be negligible + +compared to what happens to +the whole calorimeter. + +OK? + +So now if we say, OK, we we've +done this calculation starting + +with 2 moles of this, but now +we're going to be at 0.1 mole, + +so we're going to need to +divide by 20, right. + +So instead of minus 1652, it's +going to turn out delta u is + +minus 1648 kilojoules, so, and +then divide by twenty, we end + +up with minus 82.4 kilojoules, +that is, that's the delta u of + +reaction for what happens if +you'd put in not two moles of + +this, but 0.1 mole +of this, right. + +Practical amounts is the reason +I'm using numbers like + +this, right. + +So now, what's delta T? + +Well here's Cv, right, so delta +T is just our minus 10 + +kilojoules per degree oh sorry, +it's our minus 82.4 + +kilojoules. + +That's the heat released, +divided by minus 10 or 10 + +kilojoules per Kelvin, right. + +It's 8.2 Kelvin. + +In other words, how much does +the temperature of the whole + +thing change when you put an +ordinary amount of material in + +there and run a reaction, +right. + +Well, what do you do? + +You calculate how much heat is +released in the reaction. + +And then what's going to matter +is what's the heat + +capacity of the whole, +of the calorimeter? + +I didn't even need to know +that heat capacity of the + +product, right. + +Because it's effect the thermal +mass of the product is + +negligible compared to the +thermal mass of the + +calorimeter. + +Now in real practice, I'll do +the calculation in reverse. + +I'll measure how much the +temperature changed in the + +calorimeter, right. + +I'll know the heat capacity, +and what I'll really be + +calculating is OK, how much heat +must have been released + +in the reaction to make that +temperature change happen? + +And that in the case of constant +volume, in this case + +that's my delta u, and then +I'll add my little delta n + +term to get delta H. + +Any questions on calorimetry? + +OK. + +See you Friday. + +We'll finish on calorimetry and +thermochemistry and then + +we'll start in on one of the +really most difficult topics + +that we'll deal with all +semester, which is a second + +law and our special function +that we've seen just a little + +bit so far. \ No newline at end of file diff --git a/75PZmUc0TK0.txt b/75PZmUc0TK0.txt new file mode 100644 index 0000000000000000000000000000000000000000..93d921ff6357d9b8aa5f13c6454336e0f91ea509 --- /dev/null +++ b/75PZmUc0TK0.txt @@ -0,0 +1,8739 @@ +align:start position:0% + +Uh last time we talked about the picard + + align:start position:0% +Uh last time we talked about the picard + + + align:start position:0% +Uh last time we talked about the picard +uh lindelof theorem. + + align:start position:0% + + + + align:start position:0% + +And so this theorem is about uh + + align:start position:0% +And so this theorem is about uh + + + align:start position:0% +And so this theorem is about uh +solutions uh to + + align:start position:0% + + + + align:start position:0% + +to ODEs. + + align:start position:0% + + + + align:start position:0% + +And so specifically it's it's asking + + align:start position:0% +And so specifically it's it's asking + + + align:start position:0% +And so specifically it's it's asking +that so you have a function uh f + + align:start position:0% +that so you have a function uh f + + + align:start position:0% +that so you have a function uh f +and a function g + + align:start position:0% + + + + align:start position:0% + +and uh f here is is is differentiable + + align:start position:0% + + + + align:start position:0% + +and the derivative of of f as well as g + + align:start position:0% +and the derivative of of f as well as g + + + align:start position:0% +and the derivative of of f as well as g +are continuous. + + align:start position:0% + + + + align:start position:0% + +And then the problem is that you're + + align:start position:0% +And then the problem is that you're + + + align:start position:0% +And then the problem is that you're +looking for solutions. So you want a + + align:start position:0% +looking for solutions. So you want a + + + align:start position:0% +looking for solutions. So you want a +solution. So looking + + align:start position:0% + + + + align:start position:0% + +for a solution + + align:start position:0% + + + + align:start position:0% + +y to the OD + + align:start position:0% + + + + align:start position:0% + +where the and the OD is that the + + align:start position:0% +where the and the OD is that the + + + align:start position:0% +where the and the OD is that the +derivative + + align:start position:0% +derivative + + + align:start position:0% +derivative +should be equal to f of y. + + align:start position:0% +should be equal to f of y. + + + align:start position:0% +should be equal to f of y. +So at some point uh x + + align:start position:0% +So at some point uh x + + + align:start position:0% +So at some point uh x +uh the derivative of y should be equal + + align:start position:0% +uh the derivative of y should be equal + + + align:start position:0% +uh the derivative of y should be equal +to f of y of x plus g of x + + align:start position:0% +to f of y of x plus g of x + + + align:start position:0% +to f of y of x plus g of x +and uh you are looking for that uh that + + align:start position:0% +and uh you are looking for that uh that + + + align:start position:0% +and uh you are looking for that uh that +this function that y of zero say is + + align:start position:0% +this function that y of zero say is + + + align:start position:0% +this function that y of zero say is +equal to a. Okay. So this is what's + + align:start position:0% +equal to a. Okay. So this is what's + + + align:start position:0% +equal to a. Okay. So this is what's +called the initial condition, + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +right? And this is so the this is equal + + align:start position:0% +right? And this is so the this is equal + + + align:start position:0% +right? And this is so the this is equal +to that. + + align:start position:0% + + + + align:start position:0% + +And so in order to uh so we want ex you + + align:start position:0% +And so in order to uh so we want ex you + + + align:start position:0% +And so in order to uh so we want ex you +uh existence. So want + + align:start position:0% +uh existence. So want + + + align:start position:0% +uh existence. So want +existence + + align:start position:0% + + + + align:start position:0% + +and uniqueness. + + align:start position:0% + + + + align:start position:0% + +So existence just means that there is a + + align:start position:0% +So existence just means that there is a + + + align:start position:0% +So existence just means that there is a +solution for a given a there is a + + align:start position:0% +solution for a given a there is a + + + align:start position:0% +solution for a given a there is a +solution. Uniqueness means that if you + + align:start position:0% +solution. Uniqueness means that if you + + + align:start position:0% +solution. Uniqueness means that if you +have two solutions + + align:start position:0% +have two solutions + + + align:start position:0% +have two solutions +uh to this uh od then they will have to + + align:start position:0% +uh to this uh od then they will have to + + + align:start position:0% +uh to this uh od then they will have to +coincide. + + align:start position:0% +coincide. + + + align:start position:0% +coincide. +And so uh we uh the way we were setting + + align:start position:0% +And so uh we uh the way we were setting + + + align:start position:0% +And so uh we uh the way we were setting +it up was that we were using so using + + align:start position:0% +it up was that we were using so using + + + align:start position:0% +it up was that we were using so using +the contracting mapping theorem. + + align:start position:0% + + + + align:start position:0% + +So the contracting mapping theorem is + + align:start position:0% +So the contracting mapping theorem is + + + align:start position:0% +So the contracting mapping theorem is +the following that if you take a metric + + align:start position:0% +the following that if you take a metric + + + align:start position:0% +the following that if you take a metric +space + + align:start position:0% +space + + + align:start position:0% +space +X and this metric space is so X comma D + + align:start position:0% +X and this metric space is so X comma D + + + align:start position:0% +X and this metric space is so X comma D +is a metric space is a cushy + + align:start position:0% + + + + align:start position:0% + +complete + + align:start position:0% + + + + align:start position:0% + +uh metric space + + align:start position:0% + + + + align:start position:0% + +uh then a contracting map. So a + + align:start position:0% +uh then a contracting map. So a + + + align:start position:0% +uh then a contracting map. So a +contracting map + + align:start position:0% + + + + align:start position:0% + +um is a map + + align:start position:0% + + + + align:start position:0% + +t from this metric space into itself. + + align:start position:0% +t from this metric space into itself. + + + align:start position:0% +t from this metric space into itself. +So that um um and a constant + + align:start position:0% + + + + align:start position:0% + +C strictly less than one. So that if you + + align:start position:0% +C strictly less than one. So that if you + + + align:start position:0% +C strictly less than one. So that if you +measure the distance between the images, + + align:start position:0% + + + + align:start position:0% + +the images are squeezed together. So + + align:start position:0% +the images are squeezed together. So + + + align:start position:0% +the images are squeezed together. So +this means that the the distance between + + align:start position:0% +this means that the the distance between + + + align:start position:0% +this means that the the distance between +the images is this constant that is + + align:start position:0% +the images is this constant that is + + + align:start position:0% +the images is this constant that is +strictly less than one times the + + align:start position:0% +strictly less than one times the + + + align:start position:0% +strictly less than one times the +distance between x and y. So this is a + + align:start position:0% +distance between x and y. So this is a + + + align:start position:0% +distance between x and y. So this is a +contracting map. + + align:start position:0% +contracting map. + + + align:start position:0% +contracting map. +And the contracting mapping theorem say. + + align:start position:0% +And the contracting mapping theorem say. + + + align:start position:0% +And the contracting mapping theorem say. +[Applause] + + align:start position:0% + + + + align:start position:0% + +So the contracting mapping theorem uh is + + align:start position:0% +So the contracting mapping theorem uh is + + + align:start position:0% +So the contracting mapping theorem uh is +is the following + + align:start position:0% + + + + align:start position:0% + +that uh there exist if you have a cushy + + align:start position:0% +that uh there exist if you have a cushy + + + align:start position:0% +that uh there exist if you have a cushy +complete metric space and you have a + + align:start position:0% +complete metric space and you have a + + + align:start position:0% +complete metric space and you have a +contracting map like this then uh t + + align:start position:0% +contracting map like this then uh t + + + align:start position:0% +contracting map like this then uh t +has + + align:start position:0% +has + + + align:start position:0% +has +a unique + + align:start position:0% + + + + align:start position:0% + +fix point + + align:start position:0% + + + + align:start position:0% + +and remember that a fixed point. So a + + align:start position:0% +and remember that a fixed point. So a + + + align:start position:0% +and remember that a fixed point. So a +fixed point + + align:start position:0% + + + + align:start position:0% + +this is a x in this space so that t + + align:start position:0% +this is a x in this space so that t + + + align:start position:0% +this is a x in this space so that t +leaves it invariant. + + align:start position:0% +leaves it invariant. + + + align:start position:0% +leaves it invariant. +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +And so we proved this we proved the + + align:start position:0% +And so we proved this we proved the + + + align:start position:0% +And so we proved this we proved the +contracting mapping theorem last time. + + align:start position:0% +contracting mapping theorem last time. + + + align:start position:0% +contracting mapping theorem last time. +Now + + align:start position:0% +Now + + + align:start position:0% +Now +how were we going to use this for this + + align:start position:0% +how were we going to use this for this + + + align:start position:0% +how were we going to use this for this +OD? + + align:start position:0% +OD? + + + align:start position:0% +OD? +So we define so if if um if I here is an + + align:start position:0% +So we define so if if um if I here is an + + + align:start position:0% +So we define so if if um if I here is an +interval + + align:start position:0% + + + + align:start position:0% + +containing + + align:start position:0% + + + + align:start position:0% + +containing uh + + align:start position:0% +containing uh + + + align:start position:0% +containing uh +a zero. Then we defined uh + + align:start position:0% +a zero. Then we defined uh + + + align:start position:0% +a zero. Then we defined uh +n u is a function. So n u and sorry y is + + align:start position:0% +n u is a function. So n u and sorry y is + + + align:start position:0% +n u is a function. So n u and sorry y is +a continuous function. + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +Then we defined t of y. So this is a + + align:start position:0% +Then we defined t of y. So this is a + + + align:start position:0% +Then we defined t of y. So this is a +continuous function on on the interval + + align:start position:0% +continuous function on on the interval + + + align:start position:0% +continuous function on on the interval +on i. + + align:start position:0% +on i. + + + align:start position:0% +on i. +Then we defined a another continuous + + align:start position:0% +Then we defined a another continuous + + + align:start position:0% +Then we defined a another continuous +function on the same interval as follow + + align:start position:0% +function on the same interval as follow + + + align:start position:0% +function on the same interval as follow +that the + + align:start position:0% +that the + + + align:start position:0% +that the +t of y. So this is going to be a + + align:start position:0% +t of y. So this is going to be a + + + align:start position:0% +t of y. So this is going to be a +continuous function. + + align:start position:0% +continuous function. + + + align:start position:0% +continuous function. +So in in x + + align:start position:0% +So in in x + + + align:start position:0% +So in in x +this thing here is this is a + + align:start position:0% + + + + align:start position:0% + +because we want it to have value at zero + + align:start position:0% +because we want it to have value at zero + + + align:start position:0% +because we want it to have value at zero +a and then we're integrating from zero + + align:start position:0% +a and then we're integrating from zero + + + align:start position:0% +a and then we're integrating from zero +to x of f + + align:start position:0% +to x of f + + + align:start position:0% +to x of f +of uh y of s + + align:start position:0% +of uh y of s + + + align:start position:0% +of uh y of s +plus g of s + + align:start position:0% +plus g of s + + + align:start position:0% +plus g of s +ds Right. + + align:start position:0% +ds Right. + + + align:start position:0% +ds Right. +And so this + + align:start position:0% +And so this + + + align:start position:0% +And so this +so this here gives you a map from t + + align:start position:0% +so this here gives you a map from t + + + align:start position:0% +so this here gives you a map from t +gives you a map from the continuous + + align:start position:0% +gives you a map from the continuous + + + align:start position:0% +gives you a map from the continuous +function on this interval into the + + align:start position:0% +function on this interval into the + + + align:start position:0% +function on this interval into the +continuous function on the interval. + + align:start position:0% +continuous function on the interval. + + + align:start position:0% +continuous function on the interval. +And it also has the property that if you + + align:start position:0% +And it also has the property that if you + + + align:start position:0% +And it also has the property that if you +take a function + + align:start position:0% +take a function + + + align:start position:0% +take a function +and you evaluate it at zero then you get + + align:start position:0% +and you evaluate it at zero then you get + + + align:start position:0% +and you evaluate it at zero then you get +a + + align:start position:0% +a + + + align:start position:0% +a +okay. And now we observe that in fact + + align:start position:0% +okay. And now we observe that in fact + + + align:start position:0% +okay. And now we observe that in fact +this the image here + + align:start position:0% +this the image here + + + align:start position:0% +this the image here +the image is if you define when you + + align:start position:0% +the image is if you define when you + + + align:start position:0% +the image is if you define when you +define it like this by the fundamental + + align:start position:0% +define it like this by the fundamental + + + align:start position:0% +define it like this by the fundamental +theorem of calculus this function here + + align:start position:0% +theorem of calculus this function here + + + align:start position:0% +theorem of calculus this function here +is differentiable. + + align:start position:0% + + + + align:start position:0% + +So this function is so it actually takes + + align:start position:0% +So this function is so it actually takes + + + align:start position:0% +So this function is so it actually takes +so t actually takes + + align:start position:0% +so t actually takes + + + align:start position:0% +so t actually takes +the space of continuous functions + + align:start position:0% +the space of continuous functions + + + align:start position:0% +the space of continuous functions +into the space of functions that are not + + align:start position:0% +into the space of functions that are not + + + align:start position:0% +into the space of functions that are not +just continuous but actually + + align:start position:0% +just continuous but actually + + + align:start position:0% +just continuous but actually +differentiable + + align:start position:0% +differentiable + + + align:start position:0% +differentiable +and even the derivative is continuous + + align:start position:0% +and even the derivative is continuous + + + align:start position:0% +and even the derivative is continuous +and the ones that are + + align:start position:0% +and the ones that are + + + align:start position:0% +and the ones that are +um so this here is a space of functions. + + align:start position:0% +um so this here is a space of functions. + + + align:start position:0% +um so this here is a space of functions. +So this is functions + + align:start position:0% + + + + align:start position:0% + +that are um that are where where the + + align:start position:0% +that are um that are where where the + + + align:start position:0% +that are um that are where where the +functions y so that y prime exist + + align:start position:0% + + + + align:start position:0% + +and is continuous. + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% + + + + align:start position:0% + +So + + align:start position:0% +So + + + align:start position:0% +So +right and so now what we saw last time + + align:start position:0% +right and so now what we saw last time + + + align:start position:0% +right and so now what we saw last time +was that by the fundamental theorem of + + align:start position:0% +was that by the fundamental theorem of + + + align:start position:0% +was that by the fundamental theorem of +calculus + + align:start position:0% + + + + align:start position:0% + +of calculus. + + align:start position:0% + + + + align:start position:0% + +Um + + align:start position:0% +Um + + + align:start position:0% +Um +the derivative + + align:start position:0% + + + + align:start position:0% + +Right? So by the fundamental therm + + align:start position:0% +Right? So by the fundamental therm + + + align:start position:0% +Right? So by the fundamental therm +calculus the derivative of this function + + align:start position:0% +calculus the derivative of this function + + + align:start position:0% +calculus the derivative of this function +if you take y and you take t of it this + + align:start position:0% +if you take y and you take t of it this + + + align:start position:0% +if you take y and you take t of it this +is now a function and it's + + align:start position:0% +is now a function and it's + + + align:start position:0% +is now a function and it's +differentiable and the derivative is f + + align:start position:0% +differentiable and the derivative is f + + + align:start position:0% +differentiable and the derivative is f +of y. + + align:start position:0% +of y. + + + align:start position:0% +of y. +So at x it's f of y of x plus g of x. + + align:start position:0% +So at x it's f of y of x plus g of x. + + + align:start position:0% +So at x it's f of y of x plus g of x. +And so this means that if so if + + align:start position:0% +And so this means that if so if + + + align:start position:0% +And so this means that if so if +y + + align:start position:0% +y + + + align:start position:0% +y +is a fixed point + + align:start position:0% +is a fixed point + + + align:start position:0% +is a fixed point +for the map t. So if it's a fixed point, + + align:start position:0% +for the map t. So if it's a fixed point, + + + align:start position:0% +for the map t. So if it's a fixed point, +this just means that t of y is equal to + + align:start position:0% +this just means that t of y is equal to + + + align:start position:0% +this just means that t of y is equal to +y. Well then + + align:start position:0% +y. Well then + + + align:start position:0% +y. Well then +then this thing here is the derivative + + align:start position:0% +then this thing here is the derivative + + + align:start position:0% +then this thing here is the derivative +of y. So then it means that y here + + align:start position:0% +of y. So then it means that y here + + + align:start position:0% +of y. So then it means that y here +solves the + + align:start position:0% + + + + align:start position:0% + +right. We have already checked that the + + align:start position:0% +right. We have already checked that the + + + align:start position:0% +right. We have already checked that the +initial value we did that uh somewhere + + align:start position:0% +initial value we did that uh somewhere + + + align:start position:0% +initial value we did that uh somewhere +here we already checked that the initial + + align:start position:0% +here we already checked that the initial + + + align:start position:0% +here we already checked that the initial +value is what it should be and if it's a + + align:start position:0% +value is what it should be and if it's a + + + align:start position:0% +value is what it should be and if it's a +fixed point then the derivative is also + + align:start position:0% +fixed point then the derivative is also + + + align:start position:0% +fixed point then the derivative is also +what it should be. Right? + + align:start position:0% +what it should be. Right? + + + align:start position:0% +what it should be. Right? +Okay. So we want to find a fixed point + + align:start position:0% +Okay. So we want to find a fixed point + + + align:start position:0% +Okay. So we want to find a fixed point +and so what we did last time was that we + + align:start position:0% +and so what we did last time was that we + + + align:start position:0% +and so what we did last time was that we +saw that if we if we restrict the + + align:start position:0% +saw that if we if we restrict the + + + align:start position:0% +saw that if we if we restrict the +interval. + + align:start position:0% +interval. + + + align:start position:0% +interval. +So last time + + align:start position:0% + + + + align:start position:0% + +what we proved is that if we restrict + + align:start position:0% +what we proved is that if we restrict + + + align:start position:0% +what we proved is that if we restrict +the interval. So last time we showed + + align:start position:0% +the interval. So last time we showed + + + align:start position:0% +the interval. So last time we showed +so we set + + align:start position:0% + + + + align:start position:0% + +m here equal to a absolute value of a + + + align:start position:0% +m here equal to a absolute value of a + + + + align:start position:0% +m here equal to a absolute value of a + +2. + + align:start position:0% +2. + + + align:start position:0% +2. +And then we saw that there exist a delta + + align:start position:0% +And then we saw that there exist a delta + + + align:start position:0% +And then we saw that there exist a delta +zero + + align:start position:0% + + + + align:start position:0% + +at delta zero greater than zero. So that + + align:start position:0% +at delta zero greater than zero. So that + + + align:start position:0% +at delta zero greater than zero. So that +such that + + align:start position:0% +such that + + + align:start position:0% +such that +if you restrict to the interval if + + align:start position:0% +if you restrict to the interval if + + + align:start position:0% +if you restrict to the interval if +you're looking at the interval of + + align:start position:0% +you're looking at the interval of + + + align:start position:0% +you're looking at the interval of +continuous function so the interval of + + align:start position:0% +continuous function so the interval of + + + align:start position:0% +continuous function so the interval of +continuous function on this little + + align:start position:0% +continuous function on this little + + + align:start position:0% +continuous function on this little +interval. + + align:start position:0% +interval. + + + align:start position:0% +interval. +So this is a interval around zero and + + align:start position:0% +So this is a interval around zero and + + + align:start position:0% +So this is a interval around zero and +you're looking at this map. + + align:start position:0% +you're looking at this map. + + + align:start position:0% +you're looking at this map. +Then this map here well first of all we + + align:start position:0% +Then this map here well first of all we + + + align:start position:0% +Then this map here well first of all we +already know that it takes this the + + align:start position:0% +already know that it takes this the + + + align:start position:0% +already know that it takes this the +space of continuous function into the + + align:start position:0% +space of continuous function into the + + + align:start position:0% +space of continuous function into the +space of continuous function. But we + + align:start position:0% +space of continuous function. But we + + + align:start position:0% +space of continuous function. But we +have something more that we have that if + + align:start position:0% +have something more that we have that if + + + align:start position:0% +have something more that we have that if +you're looking at the subspace of this + + align:start position:0% +you're looking at the subspace of this + + + align:start position:0% +you're looking at the subspace of this +which is a space of functions y that are + + align:start position:0% +which is a space of functions y that are + + + align:start position:0% +which is a space of functions y that are +here + + align:start position:0% + + + + align:start position:0% + +and you also require that the norm here + + align:start position:0% +and you also require that the norm here + + + align:start position:0% +and you also require that the norm here +is lesser equal to m. + + align:start position:0% +is lesser equal to m. + + + align:start position:0% +is lesser equal to m. +Then takes + + align:start position:0% +Then takes + + + align:start position:0% +Then takes +this space here into itself. Right? This + + align:start position:0% +this space here into itself. Right? This + + + align:start position:0% +this space here into itself. Right? This +is this lema that we proved last time, + + align:start position:0% +is this lema that we proved last time, + + + align:start position:0% +is this lema that we proved last time, +right? And and so okay. + + align:start position:0% +right? And and so okay. + + + align:start position:0% +right? And and so okay. +So so this this space here, right? You + + align:start position:0% +So so this this space here, right? You + + + align:start position:0% +So so this this space here, right? You +can think about this space here as we + + align:start position:0% +can think about this space here as we + + + align:start position:0% +can think about this space here as we +did last time as then we defined we + + align:start position:0% +did last time as then we defined we + + + align:start position:0% +did last time as then we defined we +defined + + align:start position:0% + + + + align:start position:0% + +we define + + align:start position:0% +we define + + + align:start position:0% +we define +uh capital R equal to + + align:start position:0% +uh capital R equal to + + + align:start position:0% +uh capital R equal to +uh no actually so we we defined uh we + + align:start position:0% +uh no actually so we we defined uh we + + + align:start position:0% +uh no actually so we we defined uh we +looked at the balls I guess just on on + + align:start position:0% +looked at the balls I guess just on on + + + align:start position:0% +looked at the balls I guess just on on +this so we looked at the ball of + + align:start position:0% +this so we looked at the ball of + + + align:start position:0% +this so we looked at the ball of +freighers capital n + + align:start position:0% +freighers capital n + + + align:start position:0% +freighers capital n +in in in this around the zero function. + + align:start position:0% +in in in this around the zero function. + + + align:start position:0% +in in in this around the zero function. +So this thing here is the closed ball + + align:start position:0% +So this thing here is the closed ball + + + align:start position:0% +So this thing here is the closed ball +in the space of continuous function with + + align:start position:0% +in the space of continuous function with + + + align:start position:0% +in the space of continuous function with +the metric that we've been using and + + align:start position:0% +the metric that we've been using and + + + align:start position:0% +the metric that we've been using and +this set here we can think about if we + + align:start position:0% +this set here we can think about if we + + + align:start position:0% +this set here we can think about if we +want as this set. Okay. + + align:start position:0% + + + + align:start position:0% + +Okay. So now what we have is so we have + + align:start position:0% +Okay. So now what we have is so we have + + + align:start position:0% +Okay. So now what we have is so we have +so the setup now is that we want to find + + align:start position:0% +so the setup now is that we want to find + + + align:start position:0% +so the setup now is that we want to find +a fixed point for this map T right we + + align:start position:0% +a fixed point for this map T right we + + + align:start position:0% +a fixed point for this map T right we +have a space that we want to look at and + + align:start position:0% +have a space that we want to look at and + + + align:start position:0% +have a space that we want to look at and +the space is again now we're going to + + align:start position:0% +the space is again now we're going to + + + align:start position:0% +the space is again now we're going to +think about so just to so this is the + + align:start position:0% +think about so just to so this is the + + + align:start position:0% +think about so just to so this is the +space we're looking at but this is what + + align:start position:0% +space we're looking at but this is what + + + align:start position:0% +space we're looking at but this is what +we before have denoted like the ball in + + align:start position:0% +we before have denoted like the ball in + + + align:start position:0% +we before have denoted like the ball in +this metric space it's a centered at the + + align:start position:0% +this metric space it's a centered at the + + + align:start position:0% +this metric space it's a centered at the +function function that is constant zero + + align:start position:0% +function function that is constant zero + + + align:start position:0% +function function that is constant zero +and this is the radius right + + align:start position:0% +and this is the radius right + + + align:start position:0% +and this is the radius right +and so I'm I'm now looking at this + + align:start position:0% +and so I'm I'm now looking at this + + + align:start position:0% +and so I'm I'm now looking at this +this map so we have now shown that it + + align:start position:0% +this map so we have now shown that it + + + align:start position:0% +this map so we have now shown that it +take this metric ball into itself okay + + align:start position:0% +take this metric ball into itself okay + + + align:start position:0% +take this metric ball into itself okay +and I want to find a fixed point want to + + align:start position:0% +and I want to find a fixed point want to + + + align:start position:0% +and I want to find a fixed point want to +find a fix + + align:start position:0% + + + + align:start position:0% + +fixed point + + align:start position:0% + + + + align:start position:0% + +of t. + + align:start position:0% +of t. + + + align:start position:0% +of t. +Okay. So I need to I need to show So we + + align:start position:0% +Okay. So I need to I need to show So we + + + align:start position:0% +Okay. So I need to I need to show So we +want to show + + align:start position:0% +want to show + + + align:start position:0% +want to show +want to show + + align:start position:0% + + + + align:start position:0% + +that T + + align:start position:0% +that T + + + align:start position:0% +that T +is a contracting map, + + align:start position:0% + + + + align:start position:0% + +right? Because if it is a contracting + + align:start position:0% +right? Because if it is a contracting + + + align:start position:0% +right? Because if it is a contracting +map, then we already know that if you + + align:start position:0% +map, then we already know that if you + + + align:start position:0% +map, then we already know that if you +take a closed interval like this + + align:start position:0% + + + + align:start position:0% + +and you equip it with the usual distance + + align:start position:0% +and you equip it with the usual distance + + + align:start position:0% +and you equip it with the usual distance +that we have, this here is this here is + + align:start position:0% +that we have, this here is this here is + + + align:start position:0% +that we have, this here is this here is +cushy complete, + + align:start position:0% + + + + align:start position:0% + +right? But now if you take a cushy + + align:start position:0% +right? But now if you take a cushy + + + align:start position:0% +right? But now if you take a cushy +complete space and you're taking a + + align:start position:0% +complete space and you're taking a + + + align:start position:0% +complete space and you're taking a +closed subset and this here is a closed + + align:start position:0% +closed subset and this here is a closed + + + align:start position:0% +closed subset and this here is a closed +subset then this here is also cushy + + align:start position:0% +subset then this here is also cushy + + + align:start position:0% +subset then this here is also cushy +complete this here is also + + align:start position:0% + + + + align:start position:0% + +okay. So if we could prove that t from + + align:start position:0% +okay. So if we could prove that t from + + + align:start position:0% +okay. So if we could prove that t from +this space into itself is a contracting + + align:start position:0% +this space into itself is a contracting + + + align:start position:0% +this space into itself is a contracting +map. So it means that the existence C + + align:start position:0% +map. So it means that the existence C + + + align:start position:0% +map. So it means that the existence C +strictly less than one. Then we would + + align:start position:0% +strictly less than one. Then we would + + + align:start position:0% +strictly less than one. Then we would +have a fixed point and we would have a + + align:start position:0% +have a fixed point and we would have a + + + align:start position:0% +have a fixed point and we would have a +solution to the OD. Right? The thing is + + align:start position:0% +solution to the OD. Right? The thing is + + + align:start position:0% +solution to the OD. Right? The thing is +that this is not quite going to do it. + + align:start position:0% +that this is not quite going to do it. + + + align:start position:0% +that this is not quite going to do it. +It's not quite a contracting map, + + align:start position:0% +It's not quite a contracting map, + + + align:start position:0% +It's not quite a contracting map, +but so so we will need so for it + + align:start position:0% + + + + align:start position:0% + +to be + + align:start position:0% +to be + + + align:start position:0% +to be +a contracting map. + + align:start position:0% + + + + align:start position:0% + +We need to restrict + + align:start position:0% + + + + align:start position:0% + +the interval + + align:start position:0% + + + + align:start position:0% + +further. + + align:start position:0% + + + + align:start position:0% + +Okay. So by that I mean that we so we + + align:start position:0% +Okay. So by that I mean that we so we + + + align:start position:0% +Okay. So by that I mean that we so we +need to find we need to + + align:start position:0% +need to find we need to + + + align:start position:0% +need to find we need to +we need a delta to be + + align:start position:0% +we need a delta to be + + + align:start position:0% +we need a delta to be +we need to show that there's some delta + + align:start position:0% +we need to show that there's some delta + + + align:start position:0% +we need to show that there's some delta +it will actually be less than so we need + + align:start position:0% +it will actually be less than so we need + + + align:start position:0% +it will actually be less than so we need +to show that there's some delta that is + + align:start position:0% +to show that there's some delta that is + + + align:start position:0% +to show that there's some delta that is +smaller than this delta zero and so that + + align:start position:0% +smaller than this delta zero and so that + + + align:start position:0% +smaller than this delta zero and so that +if you restrict to this space here now + + align:start position:0% +if you restrict to this space here now + + + align:start position:0% +if you restrict to this space here now +it's a continuous function I won't + + align:start position:0% +it's a continuous function I won't + + + align:start position:0% +it's a continuous function I won't +define the I won't I will denote the + + align:start position:0% +define the I won't I will denote the + + + align:start position:0% +define the I won't I will denote the +ball by the same but this here is + + align:start position:0% +ball by the same but this here is + + + align:start position:0% +ball by the same but this here is +actually a ball in a different metric + + align:start position:0% +actually a ball in a different metric + + + align:start position:0% +actually a ball in a different metric +space because this is now a ball in the + + align:start position:0% +space because this is now a ball in the + + + align:start position:0% +space because this is now a ball in the +continuous functions on this smaller + + align:start position:0% +continuous functions on this smaller + + + align:start position:0% +continuous functions on this smaller +interval. + + align:start position:0% + + + + align:start position:0% + +Okay, but it's for the same radius. + + align:start position:0% +Okay, but it's for the same radius. + + + align:start position:0% +Okay, but it's for the same radius. +Okay, so if we restrict the map to this + + align:start position:0% +Okay, so if we restrict the map to this + + + align:start position:0% +Okay, so if we restrict the map to this +space here then on this it is a + + align:start position:0% +space here then on this it is a + + + align:start position:0% +space here then on this it is a +contracting map. Okay. So we need to cut + + align:start position:0% +contracting map. Okay. So we need to cut + + + align:start position:0% +contracting map. Okay. So we need to cut +down the interval. Uh + + align:start position:0% +down the interval. Uh + + + align:start position:0% +down the interval. Uh +okay. So now how do we do that? So + + align:start position:0% +okay. So now how do we do that? So + + + align:start position:0% +okay. So now how do we do that? So +so we need a contracting property again. + + align:start position:0% +so we need a contracting property again. + + + align:start position:0% +so we need a contracting property again. +And so suppose you take two functions. + + align:start position:0% + + + + align:start position:0% + +These are continuous maps + + align:start position:0% +These are continuous maps + + + align:start position:0% +These are continuous maps +on some interval say from + + align:start position:0% + + + + align:start position:0% + +right here again delta is now that's the + + align:start position:0% +right here again delta is now that's the + + + align:start position:0% +right here again delta is now that's the +delta we're looking for and it would be + + align:start position:0% +delta we're looking for and it would be + + + align:start position:0% +delta we're looking for and it would be +smaller than delta zero so since it's + + align:start position:0% +smaller than delta zero so since it's + + + align:start position:0% +smaller than delta zero so since it's +smaller than delta zero we already know + + align:start position:0% +smaller than delta zero we already know + + + align:start position:0% +smaller than delta zero we already know +that t that so we have two maps like + + align:start position:0% +that t that so we have two maps like + + + align:start position:0% +that t that so we have two maps like +this they are both supposed to be in the + + align:start position:0% +this they are both supposed to be in the + + + align:start position:0% +this they are both supposed to be in the +ball so this means that this thing here + + align:start position:0% +ball so this means that this thing here + + + align:start position:0% +ball so this means that this thing here +is less than m and we know we have + + align:start position:0% +is less than m and we know we have + + + align:start position:0% +is less than m and we know we have +already proven just because delta is + + align:start position:0% +already proven just because delta is + + + align:start position:0% +already proven just because delta is +less than delta zero that t of this + + align:start position:0% +less than delta zero that t of this + + + align:start position:0% +less than delta zero that t of this +function here + + align:start position:0% +function here + + + align:start position:0% +function here +has norm less or equal to m. Okay. So, + + align:start position:0% +has norm less or equal to m. Okay. So, + + + align:start position:0% +has norm less or equal to m. Okay. So, +but now let's look at the difference. + + align:start position:0% +but now let's look at the difference. + + + align:start position:0% +but now let's look at the difference. +So, t of y1 + + align:start position:0% +So, t of y1 + + + align:start position:0% +So, t of y1 +uh of x minus t of y2 + + align:start position:0% +uh of x minus t of y2 + + + align:start position:0% +uh of x minus t of y2 +of x, + + align:start position:0% +of x, + + + align:start position:0% +of x, +right? And then we're interested in the + + align:start position:0% +right? And then we're interested in the + + + align:start position:0% +right? And then we're interested in the +norm here. + + align:start position:0% + + + + align:start position:0% + +And I and now x here is in this smaller + + align:start position:0% +And I and now x here is in this smaller + + + align:start position:0% +And I and now x here is in this smaller +interval. + + align:start position:0% + + + + align:start position:0% + +Okay. So now let's just write down what + + align:start position:0% +Okay. So now let's just write down what + + + align:start position:0% +Okay. So now let's just write down what +the map is. So the map here is the + + align:start position:0% +the map is. So the map here is the + + + align:start position:0% +the map is. So the map here is the +integral. So it's a sorry it's a plus + + align:start position:0% +integral. So it's a sorry it's a plus + + + align:start position:0% +integral. So it's a sorry it's a plus +the integral from zero to x of f of y1 + + align:start position:0% +the integral from zero to x of f of y1 + + + align:start position:0% +the integral from zero to x of f of y1 +s + + align:start position:0% +s + + + align:start position:0% +s +plus g of s + + align:start position:0% +plus g of s + + + align:start position:0% +plus g of s +d s + + align:start position:0% +d s + + + align:start position:0% +d s +minus + + align:start position:0% +minus + + + align:start position:0% +minus +a + the integral from zero to x of f of + + align:start position:0% +a + the integral from zero to x of f of + + + align:start position:0% +a + the integral from zero to x of f of +y 2 s + G of S + + align:start position:0% +y 2 s + G of S + + + align:start position:0% +y 2 s + G of S +DS, right? + + align:start position:0% +DS, right? + + + align:start position:0% +DS, right? +And now you see that the A's cancel, + + align:start position:0% +And now you see that the A's cancel, + + + align:start position:0% +And now you see that the A's cancel, +right? The A's here cancel + + align:start position:0% +right? The A's here cancel + + + align:start position:0% +right? The A's here cancel +and the G of S that those also cancel + + align:start position:0% +and the G of S that those also cancel + + + align:start position:0% +and the G of S that those also cancel +out, right? So you left with that this + + align:start position:0% +out, right? So you left with that this + + + align:start position:0% +out, right? So you left with that this +thing here is the absolute value of the + + align:start position:0% +thing here is the absolute value of the + + + align:start position:0% +thing here is the absolute value of the +integral from 0 to x of f of um y1 of s + + align:start position:0% +integral from 0 to x of f of um y1 of s + + + align:start position:0% +integral from 0 to x of f of um y1 of s +minus uh um f of y2 + + align:start position:0% +minus uh um f of y2 + + + align:start position:0% +minus uh um f of y2 +of s + + align:start position:0% +of s + + + align:start position:0% +of s +ds. + + align:start position:0% + + + + align:start position:0% + +Now + + align:start position:0% +Now + + + align:start position:0% +Now +we + + align:start position:0% + + + + align:start position:0% + +So last time + + align:start position:0% + + + + align:start position:0% + +when we proved that at the map + + align:start position:0% +when we proved that at the map + + + align:start position:0% +when we proved that at the map +He takes this ball into this ball we + + align:start position:0% +He takes this ball into this ball we + + + align:start position:0% +He takes this ball into this ball we +used we defined. So let me just define + + align:start position:0% +used we defined. So let me just define + + + align:start position:0% +used we defined. So let me just define +that again. We defined L1 + + align:start position:0% +that again. We defined L1 + + + align:start position:0% +that again. We defined L1 +and N1 was the the maximum + + align:start position:0% +and N1 was the the maximum + + + align:start position:0% +and N1 was the the maximum +of actually uh + + align:start position:0% +of actually uh + + + align:start position:0% +of actually uh +uh + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% +um + + + align:start position:0% +um +I don't remember whether it was called + + align:start position:0% +I don't remember whether it was called + + + align:start position:0% +I don't remember whether it was called +L1. Let me just call it L uh to not call + + align:start position:0% +L1. Let me just call it L uh to not call + + + align:start position:0% +L1. Let me just call it L uh to not call +it some. So uh L here is the maximum of + + align:start position:0% +it some. So uh L here is the maximum of + + + align:start position:0% +it some. So uh L here is the maximum of +FP prime + + align:start position:0% +FP prime + + + align:start position:0% +FP prime +um of of offset + + align:start position:0% +um of of offset + + + align:start position:0% +um of of offset +where set here + + align:start position:0% +where set here + + + align:start position:0% +where set here +has no less or equal to M. Okay. + + align:start position:0% +has no less or equal to M. Okay. + + + align:start position:0% +has no less or equal to M. Okay. +So this is so f prime exists and is + + align:start position:0% +So this is so f prime exists and is + + + align:start position:0% +So this is so f prime exists and is +continuous. So on this interval here it + + align:start position:0% +continuous. So on this interval here it + + + align:start position:0% +continuous. So on this interval here it +has a maximum. Okay. So it's a nice + + align:start position:0% +has a maximum. Okay. So it's a nice + + + align:start position:0% +has a maximum. Okay. So it's a nice +finite number. And so now we use the so + + align:start position:0% +finite number. And so now we use the so + + + align:start position:0% +finite number. And so now we use the so +by the mean value theorem + + align:start position:0% +by the mean value theorem + + + align:start position:0% +by the mean value theorem +the mean value theorem. + + align:start position:0% + + + + align:start position:0% + +By the mean value theorem, we have that + + align:start position:0% +By the mean value theorem, we have that + + + align:start position:0% +By the mean value theorem, we have that +f of set one + + align:start position:0% +f of set one + + + align:start position:0% +f of set one +minus f of set 2. As long as set one and + + align:start position:0% +minus f of set 2. As long as set one and + + + align:start position:0% +minus f of set 2. As long as set one and +set two + + align:start position:0% +set two + + + align:start position:0% +set two +are uh are in the interval from minus m + + align:start position:0% +are uh are in the interval from minus m + + + align:start position:0% +are uh are in the interval from minus m +to m. Then we have that this difference + + align:start position:0% +to m. Then we have that this difference + + + align:start position:0% +to m. Then we have that this difference +here is equal to the derivative in some + + align:start position:0% +here is equal to the derivative in some + + + align:start position:0% +here is equal to the derivative in some +intermediate point set sigma + + align:start position:0% +intermediate point set sigma + + + align:start position:0% +intermediate point set sigma +s I guess s times the difference between + + align:start position:0% +s I guess s times the difference between + + + align:start position:0% +s I guess s times the difference between +the two set one minus set two. So we + + align:start position:0% +the two set one minus set two. So we + + + align:start position:0% +the two set one minus set two. So we +have this right this is the mean math + + align:start position:0% +have this right this is the mean math + + + align:start position:0% +have this right this is the mean math +theorem + + align:start position:0% +theorem + + + align:start position:0% +theorem +and so we have that uh therefore we have + + align:start position:0% +and so we have that uh therefore we have + + + align:start position:0% +and so we have that uh therefore we have +that the norm here of the difference + + align:start position:0% + + + + align:start position:0% + +is bounded by this here when we take the + + align:start position:0% +is bounded by this here when we take the + + + align:start position:0% +is bounded by this here when we take the +absolute value of this we're getting the + + align:start position:0% +absolute value of this we're getting the + + + align:start position:0% +absolute value of this we're getting the +absolute value. So this here is is equal + + align:start position:0% +absolute value. So this here is is equal + + + align:start position:0% +absolute value. So this here is is equal +to the absolute value of frime sigma + + align:start position:0% +to the absolute value of frime sigma + + + align:start position:0% +to the absolute value of frime sigma +time z 1 minus z 2. + + align:start position:0% + + + + align:start position:0% + +This thing here + + align:start position:0% +This thing here + + + align:start position:0% +This thing here +because these two are in this interval + + align:start position:0% +because these two are in this interval + + + align:start position:0% +because these two are in this interval +this is bounded by by capital L. So + + align:start position:0% +this is bounded by by capital L. So + + + align:start position:0% +this is bounded by by capital L. So +you're getting this. + + align:start position:0% + + + + align:start position:0% + +And so now if you use this fact here + + align:start position:0% +And so now if you use this fact here + + + align:start position:0% +And so now if you use this fact here +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +and you use this on this. So this thing + + align:start position:0% +and you use this on this. So this thing + + + align:start position:0% +and you use this on this. So this thing +here is less or equal to the integral + + align:start position:0% +here is less or equal to the integral + + + align:start position:0% +here is less or equal to the integral +from zero to x and I can take the + + align:start position:0% +from zero to x and I can take the + + + align:start position:0% +from zero to x and I can take the +absolute value in under the integration + + align:start position:0% +absolute value in under the integration + + + align:start position:0% +absolute value in under the integration +sign. So I get f of y1 + + align:start position:0% +sign. So I get f of y1 + + + align:start position:0% +sign. So I get f of y1 +s minus + + align:start position:0% +s minus + + + align:start position:0% +s minus +uh f of y2 + + align:start position:0% +uh f of y2 + + + align:start position:0% +uh f of y2 +s + + align:start position:0% +s + + + align:start position:0% +s +ds right + + align:start position:0% +ds right + + + align:start position:0% +ds right +and so now I can continue this string so + + align:start position:0% +and so now I can continue this string so + + + align:start position:0% +and so now I can continue this string so +I have what I'm interested in is g of y1 + + align:start position:0% +I have what I'm interested in is g of y1 + + + align:start position:0% +I have what I'm interested in is g of y1 +at x minus g of y2 + + align:start position:0% +at x minus g of y2 + + + align:start position:0% +at x minus g of y2 +of x and I'm interested in the abs bound + + align:start position:0% +of x and I'm interested in the abs bound + + + align:start position:0% +of x and I'm interested in the abs bound +for the absolute value and I have that + + align:start position:0% +for the absolute value and I have that + + + align:start position:0% +for the absolute value and I have that +this is less or equal to the integral + + align:start position:0% +this is less or equal to the integral + + + align:start position:0% +this is less or equal to the integral +from 0 to x of f of y1 + + align:start position:0% +from 0 to x of f of y1 + + + align:start position:0% +from 0 to x of f of y1 +s plus f of y 2 + + align:start position:0% +s plus f of y 2 + + + align:start position:0% +s plus f of y 2 +s + + align:start position:0% +s + + + align:start position:0% +s +ds + + align:start position:0% +ds + + + align:start position:0% +ds +and now I know that this interval here + + align:start position:0% +and now I know that this interval here + + + align:start position:0% +and now I know that this interval here +right x is supposed to lie in this + + align:start position:0% +right x is supposed to lie in this + + + align:start position:0% +right x is supposed to lie in this +interval here so this means is that that + + align:start position:0% +interval here so this means is that that + + + align:start position:0% +interval here so this means is that that +this the length of this interval from + + align:start position:0% +this the length of this interval from + + + align:start position:0% +this the length of this interval from +zero to is at most delta. So delta and + + align:start position:0% +zero to is at most delta. So delta and + + + align:start position:0% +zero to is at most delta. So delta and +then I can take the maximum of this + + align:start position:0% +then I can take the maximum of this + + + align:start position:0% +then I can take the maximum of this +or I can take the uh that's right I can + + align:start position:0% +or I can take the uh that's right I can + + + align:start position:0% +or I can take the uh that's right I can +take the the maximum of this but you see + + align:start position:0% +take the the maximum of this but you see + + + align:start position:0% +take the the maximum of this but you see +that this thing here is bounded by so + + align:start position:0% +that this thing here is bounded by so + + + align:start position:0% +that this thing here is bounded by so +this is the maximum is the maximum + + align:start position:0% +this is the maximum is the maximum + + + align:start position:0% +this is the maximum is the maximum +and if I use this inequality here it's + + align:start position:0% +and if I use this inequality here it's + + + align:start position:0% +and if I use this inequality here it's +bounded by L and then it's applied this + + align:start position:0% +bounded by L and then it's applied this + + + align:start position:0% +bounded by L and then it's applied this +here you should think about as set one + + align:start position:0% +here you should think about as set one + + + align:start position:0% +here you should think about as set one +and this here for each x you can s you + + align:start position:0% +and this here for each x you can s you + + + align:start position:0% +and this here for each x you can s you +can think about this as set one and set + + align:start position:0% +can think about this as set one and set + + + align:start position:0% +can think about this as set one and set +two and so you're getting this thing + + align:start position:0% +two and so you're getting this thing + + + align:start position:0% +two and so you're getting this thing +here times y1 + + align:start position:0% +here times y1 + + + align:start position:0% +here times y1 +s - y 2 + + align:start position:0% +s - y 2 + + + align:start position:0% +s - y 2 +s and here s will now lie in the + + align:start position:0% +s and here s will now lie in the + + + align:start position:0% +s and here s will now lie in the +interval + + align:start position:0% +interval + + + align:start position:0% +interval +um + + align:start position:0% +um + + + align:start position:0% +um +in this interval here + + align:start position:0% +in this interval here + + + align:start position:0% +in this interval here +oops + + align:start position:0% +oops + + + align:start position:0% +oops +Right? And so now you see that this is + + align:start position:0% +Right? And so now you see that this is + + + align:start position:0% +Right? And so now you see that this is +just a constant. So this is equal to + + align:start position:0% +just a constant. So this is equal to + + + align:start position:0% +just a constant. So this is equal to +delta L. And then this maximum + + align:start position:0% +delta L. And then this maximum + + + align:start position:0% +delta L. And then this maximum +S lesser equal to delta + + align:start position:0% +S lesser equal to delta + + + align:start position:0% +S lesser equal to delta +Y1 + + align:start position:0% +Y1 + + + align:start position:0% +Y1 +minus Y2 + + align:start position:0% +minus Y2 + + + align:start position:0% +minus Y2 +like this. Right? This is evaluated in + + align:start position:0% +like this. Right? This is evaluated in + + + align:start position:0% +like this. Right? This is evaluated in +S. But I wouldn't I don't write that. + + align:start position:0% +S. But I wouldn't I don't write that. + + + align:start position:0% +S. But I wouldn't I don't write that. +Okay? And this thing here. But this is + + align:start position:0% +Okay? And this thing here. But this is + + + align:start position:0% +Okay? And this thing here. But this is +just delta L. This maximum here is just + + align:start position:0% +just delta L. This maximum here is just + + + align:start position:0% +just delta L. This maximum here is just +the distance between this function and + + align:start position:0% +the distance between this function and + + + align:start position:0% +the distance between this function and +that function. That's how we define this + + align:start position:0% +that function. That's how we define this + + + align:start position:0% +that function. That's how we define this +distance. Right? + + align:start position:0% +distance. Right? + + + align:start position:0% +distance. Right? +And so you see that this right hand side + + align:start position:0% +And so you see that this right hand side + + + align:start position:0% +And so you see that this right hand side +is now holds for all x. So this means + + align:start position:0% +is now holds for all x. So this means + + + align:start position:0% +is now holds for all x. So this means +that we have that the maximum of this + + align:start position:0% +that we have that the maximum of this + + + align:start position:0% +that we have that the maximum of this +thing here over x where x is in the + + align:start position:0% +thing here over x where x is in the + + + align:start position:0% +thing here over x where x is in the +interval between zero and delta. So this + + align:start position:0% +interval between zero and delta. So this + + + align:start position:0% +interval between zero and delta. So this +means that we have that the distance + + align:start position:0% +means that we have that the distance + + + align:start position:0% +means that we have that the distance +between t of y1 + + align:start position:0% +between t of y1 + + + align:start position:0% +between t of y1 +and t of y2. + + align:start position:0% +and t of y2. + + + align:start position:0% +and t of y2. +This thing here is equal to the maximum. + + align:start position:0% +This thing here is equal to the maximum. + + + align:start position:0% +This thing here is equal to the maximum. +This is how we define that distance + + align:start position:0% +This is how we define that distance + + + align:start position:0% +This is how we define that distance +after all. + + align:start position:0% + + + + align:start position:0% + +Um and then it's of this thing here + + align:start position:0% + + + + align:start position:0% + +sorry uh x + + align:start position:0% +sorry uh x + + + align:start position:0% +sorry uh x +minus t of y 2 + + align:start position:0% +minus t of y 2 + + + align:start position:0% +minus t of y 2 +in x + + align:start position:0% +in x + + + align:start position:0% +in x +right so we have that this and this + + align:start position:0% +right so we have that this and this + + + align:start position:0% +right so we have that this and this +inequality say that it's less or equal + + align:start position:0% +inequality say that it's less or equal + + + align:start position:0% +inequality say that it's less or equal +to + + align:start position:0% +to + + + align:start position:0% +to +delta uh L D Y1 comma Y2 + + align:start position:0% +delta uh L D Y1 comma Y2 + + + align:start position:0% +delta uh L D Y1 comma Y2 +and so you see that now if you so L here + + align:start position:0% +and so you see that now if you so L here + + + align:start position:0% +and so you see that now if you so L here +was just a fixed constant right if I now + + align:start position:0% +was just a fixed constant right if I now + + + align:start position:0% +was just a fixed constant right if I now +set delta just to make sure that there's + + align:start position:0% +set delta just to make sure that there's + + + align:start position:0% +set delta just to make sure that there's +no problem I'm setting delta equal to 1 + + align:start position:0% +no problem I'm setting delta equal to 1 + + + align:start position:0% +no problem I'm setting delta equal to 1 +/ 2 L I don't really need the one but I + + align:start position:0% +/ 2 L I don't really need the one but I + + + align:start position:0% +/ 2 L I don't really need the one but I +I I'll just do it like this so I don't + + align:start position:0% +I I'll just do it like this so I don't + + + align:start position:0% +I I'll just do it like this so I don't +have zero in the denominator if I choose + + align:start position:0% +have zero in the denominator if I choose + + + align:start position:0% +have zero in the denominator if I choose +the delta to be equal to this. Right? + + align:start position:0% +the delta to be equal to this. Right? + + + align:start position:0% +the delta to be equal to this. Right? +Well, then you see that this thing here + + align:start position:0% +Well, then you see that this thing here + + + align:start position:0% +Well, then you see that this thing here +the the inner product of these two is + + align:start position:0% +the the inner product of these two is + + + align:start position:0% +the the inner product of these two is +less or the the product of these two is + + align:start position:0% +less or the the product of these two is + + + align:start position:0% +less or the the product of these two is +less than a half. So this is less or + + align:start position:0% +less than a half. So this is less or + + + align:start position:0% +less than a half. So this is less or +equal to I can just place it by a half + + align:start position:0% + + + + align:start position:0% + +like that. Right? + + align:start position:0% +like that. Right? + + + align:start position:0% +like that. Right? +And so you see this is exactly what it + + align:start position:0% +And so you see this is exactly what it + + + align:start position:0% +And so you see this is exactly what it +means to be a contracting mapping. In + + align:start position:0% +means to be a contracting mapping. In + + + align:start position:0% +means to be a contracting mapping. In +fact, it's a contracting mapping which + + align:start position:0% +fact, it's a contracting mapping which + + + align:start position:0% +fact, it's a contracting mapping which +is pretty nice + + align:start position:0% +is pretty nice + + + align:start position:0% +is pretty nice +that the constant it's not just strictly + + align:start position:0% +that the constant it's not just strictly + + + align:start position:0% +that the constant it's not just strictly +some constant strictly less than one but + + align:start position:0% +some constant strictly less than one but + + + align:start position:0% +some constant strictly less than one but +it's actually a half right. So it's a + + align:start position:0% +it's actually a half right. So it's a + + + align:start position:0% +it's actually a half right. So it's a +contracting mapping theorem a + + align:start position:0% +contracting mapping theorem a + + + align:start position:0% +contracting mapping theorem a +contracting map and so now by the + + align:start position:0% +contracting map and so now by the + + + align:start position:0% +contracting map and so now by the +contracting mapping theorem we have a + + align:start position:0% +contracting mapping theorem we have a + + + align:start position:0% +contracting mapping theorem we have a +fixed point. Okay. + + align:start position:0% +fixed point. Okay. + + + align:start position:0% +fixed point. Okay. +So this solve the OD. Okay. And it do + + align:start position:0% +So this solve the OD. Okay. And it do + + + align:start position:0% +So this solve the OD. Okay. And it do +does more than that because a + + align:start position:0% +does more than that because a + + + align:start position:0% +does more than that because a +contracting mapping theorem says that it + + align:start position:0% +contracting mapping theorem says that it + + + align:start position:0% +contracting mapping theorem says that it +has a unique + + align:start position:0% +has a unique + + + align:start position:0% +has a unique +uh unique fix point. Right? So this + + align:start position:0% +uh unique fix point. Right? So this + + + align:start position:0% +uh unique fix point. Right? So this +means that and and if you have a + + align:start position:0% +means that and and if you have a + + + align:start position:0% +means that and and if you have a +solution to this, right? If you have a + + align:start position:0% +solution to this, right? If you have a + + + align:start position:0% +solution to this, right? If you have a +solution to this, then we saw last time + + align:start position:0% +solution to this, then we saw last time + + + align:start position:0% +solution to this, then we saw last time +that if it is a solution, then it is a + + align:start position:0% +that if it is a solution, then it is a + + + align:start position:0% +that if it is a solution, then it is a +fixed point, right? + + align:start position:0% +fixed point, right? + + + align:start position:0% +fixed point, right? +Okay. So now we almost have existence + + align:start position:0% +Okay. So now we almost have existence + + + align:start position:0% +Okay. So now we almost have existence +and uniqueness. + + align:start position:0% +and uniqueness. + + + align:start position:0% +and uniqueness. +Uh let me explain what is missing to the + + align:start position:0% +Uh let me explain what is missing to the + + + align:start position:0% +Uh let me explain what is missing to the +existence of uniqueness. + + align:start position:0% + + + + align:start position:0% + +So for that + + align:start position:0% +So for that + + + align:start position:0% +So for that +let me + + align:start position:0% + + + + align:start position:0% + +backtrack a little bit and talk about + + align:start position:0% +backtrack a little bit and talk about + + + align:start position:0% +backtrack a little bit and talk about +something about metric spaces. + + align:start position:0% + + + + align:start position:0% + +bases specifically uh about connected + + align:start position:0% +bases specifically uh about connected + + + align:start position:0% +bases specifically uh about connected +matrix bases. + + align:start position:0% + + + + align:start position:0% + +Okay. So suppose you have a metric space + + align:start position:0% + + + + align:start position:0% + +then we say + + align:start position:0% + + + + align:start position:0% + +that + + align:start position:0% +that + + + align:start position:0% +that +It is connected + + align:start position:0% + + + + align:start position:0% + +if um if x here is the only subset + + align:start position:0% +if um if x here is the only subset + + + align:start position:0% +if um if x here is the only subset +only subset. So, so the whole set itself + + align:start position:0% +only subset. So, so the whole set itself + + + align:start position:0% +only subset. So, so the whole set itself +is the only subset + + align:start position:0% +is the only subset + + + align:start position:0% +is the only subset +of of X that is + + align:start position:0% +of of X that is + + + align:start position:0% +of of X that is +is both open and closed. + + align:start position:0% + + + + align:start position:0% + +Right? Remember that if you take a + + align:start position:0% +Right? Remember that if you take a + + + align:start position:0% +Right? Remember that if you take a +metric space then the sorry if + + align:start position:0% +metric space then the sorry if + + + align:start position:0% +metric space then the sorry if +if X and sorry and and the empty set are + + align:start position:0% +if X and sorry and and the empty set are + + + align:start position:0% +if X and sorry and and the empty set are +the only + + align:start position:0% +the only + + + align:start position:0% +the only +uh subset of X that are both open and + + align:start position:0% +uh subset of X that are both open and + + + align:start position:0% +uh subset of X that are both open and +closed. Right? Remember that if you take + + align:start position:0% +closed. Right? Remember that if you take + + + align:start position:0% +closed. Right? Remember that if you take +a metric space and if you take the whole + + align:start position:0% +a metric space and if you take the whole + + + align:start position:0% +a metric space and if you take the whole +set or the empty set, those are all + + align:start position:0% +set or the empty set, those are all + + + align:start position:0% +set or the empty set, those are all +they're both always closed and open, + + align:start position:0% +they're both always closed and open, + + + align:start position:0% +they're both always closed and open, +right? And so it's connected if those + + align:start position:0% +right? And so it's connected if those + + + align:start position:0% +right? And so it's connected if those +are the only two subsets that are at the + + align:start position:0% +are the only two subsets that are at the + + + align:start position:0% +are the only two subsets that are at the +same time open and closed. Okay? + + align:start position:0% +same time open and closed. Okay? + + + align:start position:0% +same time open and closed. Okay? +And so now + + align:start position:0% +And so now + + + align:start position:0% +And so now +we have that we have the following + + align:start position:0% + + + + align:start position:0% + +we have the following lema + + align:start position:0% +we have the following lema + + + align:start position:0% +we have the following lema +or theorem just call it theorem + + align:start position:0% + + + + align:start position:0% + +that if you take a interval here with a + + align:start position:0% +that if you take a interval here with a + + + align:start position:0% +that if you take a interval here with a +usual metric here so this is so I here + + align:start position:0% +usual metric here so this is so I here + + + align:start position:0% +usual metric here so this is so I here +is a interval + + align:start position:0% + + + + align:start position:0% + +then uh the theorem is that that that + + align:start position:0% +then uh the theorem is that that that + + + align:start position:0% +then uh the theorem is that that that +uh this metric space here so is + + align:start position:0% +uh this metric space here so is + + + align:start position:0% +uh this metric space here so is +connected. + + align:start position:0% + + + + align:start position:0% + +Okay. So let's try to prove that. + + align:start position:0% + + + + align:start position:0% + +So I take now a subset + + align:start position:0% +So I take now a subset + + + align:start position:0% +So I take now a subset +here uh that is + + align:start position:0% +here uh that is + + + align:start position:0% +here uh that is +is both open + + align:start position:0% +is both open + + + align:start position:0% +is both open +open and closed. + + align:start position:0% + + + + align:start position:0% + +And we want to show + + align:start position:0% +And we want to show + + + align:start position:0% +And we want to show +want to show + + align:start position:0% + + + + align:start position:0% + +that + + align:start position:0% +that + + + align:start position:0% +that +if a here is non- empty + + align:start position:0% +if a here is non- empty + + + align:start position:0% +if a here is non- empty +then it implies that a + + align:start position:0% +then it implies that a + + + align:start position:0% +then it implies that a +is is everything. Right? So we're + + align:start position:0% +is is everything. Right? So we're + + + align:start position:0% +is is everything. Right? So we're +assuming that it's non- empty and then + + align:start position:0% +assuming that it's non- empty and then + + + align:start position:0% +assuming that it's non- empty and then +we should apply uh to try to prove that + + align:start position:0% +we should apply uh to try to prove that + + + align:start position:0% +we should apply uh to try to prove that +a is everything. + + align:start position:0% + + + + align:start position:0% + +So we let + + align:start position:0% +So we let + + + align:start position:0% +So we let +x0 be an element in a right but right + + align:start position:0% +x0 be an element in a right but right + + + align:start position:0% +x0 be an element in a right but right +we're assuming it's not empty so we can + + align:start position:0% +we're assuming it's not empty so we can + + + align:start position:0% +we're assuming it's not empty so we can +let x0 be an element in a + + align:start position:0% +let x0 be an element in a + + + align:start position:0% +let x0 be an element in a +and now I want to define + + align:start position:0% +and now I want to define + + + align:start position:0% +and now I want to define +um I want to + + align:start position:0% + + + + align:start position:0% + +I want to so I have here I have here my + + align:start position:0% +I want to so I have here I have here my + + + align:start position:0% +I want to so I have here I have here my +interval this is my interval I + + align:start position:0% +interval this is my interval I + + + align:start position:0% +interval this is my interval I +have here x0 + + align:start position:0% +have here x0 + + + align:start position:0% +have here x0 +and I take uh and I'm looking at the the + + align:start position:0% +and I take uh and I'm looking at the the + + + align:start position:0% +and I take uh and I'm looking at the the +y + + align:start position:0% + + + + align:start position:0% + +uh in + + align:start position:0% +uh in + + + align:start position:0% +uh in +in a + + align:start position:0% +in a + + + align:start position:0% +in a +so that um + + align:start position:0% +so that um + + + align:start position:0% +so that um +that if you take everything + + align:start position:0% +that if you take everything + + + align:start position:0% +that if you take everything +uh so that so y is an a and I'm going to + + align:start position:0% +uh so that so y is an a and I'm going to + + + align:start position:0% +uh so that so y is an a and I'm going to +look at y in a with + + align:start position:0% +look at y in a with + + + align:start position:0% +look at y in a with +y bigger equal to x0 and I'm going to + + align:start position:0% +y bigger equal to x0 and I'm going to + + + align:start position:0% +y bigger equal to x0 and I'm going to +look at the y so that that this whole + + align:start position:0% +look at the y so that that this whole + + + align:start position:0% +look at the y so that that this whole +interval here from x0 to y + + align:start position:0% +interval here from x0 to y + + + align:start position:0% +interval here from x0 to y +is contained in a + + align:start position:0% +is contained in a + + + align:start position:0% +is contained in a +so I'm defining so + + align:start position:0% +so I'm defining so + + + align:start position:0% +so I'm defining so +so define + + align:start position:0% + + + + align:start position:0% + +as subset here + + align:start position:0% + + + + align:start position:0% + +B + + align:start position:0% +B + + + align:start position:0% +B +of of I + + align:start position:0% + + + + align:start position:0% + +so that uh it's the y this subset b is + + align:start position:0% +so that uh it's the y this subset b is + + + align:start position:0% +so that uh it's the y this subset b is +the y in a with a property that it is + + align:start position:0% +the y in a with a property that it is + + + align:start position:0% +the y in a with a property that it is +that y here is big or equal to x0 and + + align:start position:0% +that y here is big or equal to x0 and + + + align:start position:0% +that y here is big or equal to x0 and +and you have + + align:start position:0% +and you have + + + align:start position:0% +and you have +And this interval here + + align:start position:0% +And this interval here + + + align:start position:0% +And this interval here +is contained in a + + align:start position:0% +is contained in a + + + align:start position:0% +is contained in a +okay + + align:start position:0% + + + + align:start position:0% + +and now I want to show that so let's say + + align:start position:0% +and now I want to show that so let's say + + + align:start position:0% +and now I want to show that so let's say +let's say for the sake of argument let + + align:start position:0% +let's say for the sake of argument let + + + align:start position:0% +let's say for the sake of argument let +me assume + + align:start position:0% +me assume + + + align:start position:0% +me assume +that this interval is a closed interval + + align:start position:0% +that this interval is a closed interval + + + align:start position:0% +that this interval is a closed interval +like this it works equally well the + + align:start position:0% +like this it works equally well the + + + align:start position:0% +like this it works equally well the +argument with obvious modification + + align:start position:0% +argument with obvious modification + + + align:start position:0% +argument with obvious modification +work each equally well if it's open or + + align:start position:0% +work each equally well if it's open or + + + align:start position:0% +work each equally well if it's open or +half open uh interval. + + align:start position:0% + + + + align:start position:0% + +Okay. So I take some y here and I have + + align:start position:0% +Okay. So I take some y here and I have + + + align:start position:0% +Okay. So I take some y here and I have +so I have a y + + align:start position:0% + + + + align:start position:0% + +and I and y is so it's a set so that + + align:start position:0% +and I and y is so it's a set so that + + + align:start position:0% +and I and y is so it's a set so that +this whole interval is contained in a + + align:start position:0% +this whole interval is contained in a + + + align:start position:0% +this whole interval is contained in a +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and what I want to show is so want to + + align:start position:0% +and what I want to show is so want to + + + align:start position:0% +and what I want to show is so want to +show + + align:start position:0% + + + + align:start position:0% + +that y is in a And this is the first + + align:start position:0% +that y is in a And this is the first + + + align:start position:0% +that y is in a And this is the first +thing I want to show. One is that y is + + align:start position:0% +thing I want to show. One is that y is + + + align:start position:0% +thing I want to show. One is that y is +in a + + align:start position:0% +in a + + + align:start position:0% +in a +and then I want the second thing I want + + align:start position:0% +and then I want the second thing I want + + + align:start position:0% +and then I want the second thing I want +to show is that y + + align:start position:0% +to show is that y + + + align:start position:0% +to show is that y +is equal to b. + + align:start position:0% +is equal to b. + + + align:start position:0% +is equal to b. +You see if I had proven both of these + + align:start position:0% +You see if I had proven both of these + + + align:start position:0% +You see if I had proven both of these +property right then it would be that so + + align:start position:0% +property right then it would be that so + + + align:start position:0% +property right then it would be that so +then um then + + align:start position:0% +then um then + + + align:start position:0% +then um then +um it would mean that everything here + + align:start position:0% +um it would mean that everything here + + + align:start position:0% +um it would mean that everything here +would be in a and including this last + + align:start position:0% +would be in a and including this last + + + align:start position:0% +would be in a and including this last +point right and so this means that we + + align:start position:0% +point right and so this means that we + + + align:start position:0% +point right and so this means that we +have this entire interval is in a is in + + align:start position:0% +have this entire interval is in a is in + + + align:start position:0% +have this entire interval is in a is in +I sorry and then likewise we could argue + + align:start position:0% +I sorry and then likewise we could argue + + + align:start position:0% +I sorry and then likewise we could argue +on the other side Okay. + + align:start position:0% +on the other side Okay. + + + align:start position:0% +on the other side Okay. +So now how do we prove this? So + + align:start position:0% +So now how do we prove this? So + + + align:start position:0% +So now how do we prove this? So +well the first thing is that if if um + + align:start position:0% +well the first thing is that if if um + + + align:start position:0% +well the first thing is that if if um +if we take so if we set + + align:start position:0% +if we take so if we set + + + align:start position:0% +if we take so if we set +sorry this is no sorry but that's this + + align:start position:0% +sorry this is no sorry but that's this + + + align:start position:0% +sorry this is no sorry but that's this +here should have been + + align:start position:0% +here should have been + + + align:start position:0% +here should have been +this here should have been y zero and + + align:start position:0% +this here should have been y zero and + + + align:start position:0% +this here should have been y zero and +this should have been the soup + + align:start position:0% +this should have been the soup + + + align:start position:0% +this should have been the soup +of y in Okay. + + align:start position:0% + + + + align:start position:0% + +So these guys + + align:start position:0% +So these guys + + + align:start position:0% +So these guys +and then this here and we want to prove + + align:start position:0% +and then this here and we want to prove + + + align:start position:0% +and then this here and we want to prove +that this thing here is in in a + + align:start position:0% +that this thing here is in in a + + + align:start position:0% +that this thing here is in in a +and uh and the second thing is we want + + align:start position:0% +and uh and the second thing is we want + + + align:start position:0% +and uh and the second thing is we want +to prove that this soup is actually + + align:start position:0% +to prove that this soup is actually + + + align:start position:0% +to prove that this soup is actually +equal to B. Okay, that's what we want to + + align:start position:0% +equal to B. Okay, that's what we want to + + + align:start position:0% +equal to B. Okay, that's what we want to +prove. + + align:start position:0% + + + + align:start position:0% + +So the soup of these well if you have if + + align:start position:0% +So the soup of these well if you have if + + + align:start position:0% +So the soup of these well if you have if +y z is a soup of elements then you have + + align:start position:0% +y z is a soup of elements then you have + + + align:start position:0% +y z is a soup of elements then you have +a sequence. So here you have y z and + + align:start position:0% +a sequence. So here you have y z and + + + align:start position:0% +a sequence. So here you have y z and +this means that you have a sequence of + + align:start position:0% +this means that you have a sequence of + + + align:start position:0% +this means that you have a sequence of +elements + + align:start position:0% +elements + + + align:start position:0% +elements +which are then in elements in the set B. + + align:start position:0% +which are then in elements in the set B. + + + align:start position:0% +which are then in elements in the set B. +This is soup of B. + + align:start position:0% +This is soup of B. + + + align:start position:0% +This is soup of B. +Mine is the same as soup of B. Sorry, + + align:start position:0% +Mine is the same as soup of B. Sorry, + + + align:start position:0% +Mine is the same as soup of B. Sorry, +soup of B. + + align:start position:0% +soup of B. + + + align:start position:0% +soup of B. +I write like this. + + align:start position:0% +I write like this. + + + align:start position:0% +I write like this. +So I take this set and these are the Y + + align:start position:0% +So I take this set and these are the Y + + + align:start position:0% +So I take this set and these are the Y +so that this entire interval is + + align:start position:0% +so that this entire interval is + + + align:start position:0% +so that this entire interval is +contained in a right and then I take the + + align:start position:0% +contained in a right and then I take the + + + align:start position:0% +contained in a right and then I take the +soup of this set and I want to prove + + align:start position:0% +soup of this set and I want to prove + + + align:start position:0% +soup of this set and I want to prove +that this soup is in A. And then I want + + align:start position:0% +that this soup is in A. And then I want + + + align:start position:0% +that this soup is in A. And then I want +to prove that in fact the soup is B. + + align:start position:0% +to prove that in fact the soup is B. + + + align:start position:0% +to prove that in fact the soup is B. +Okay. + + align:start position:0% + + + + align:start position:0% + +So that it's a soup of of such + + align:start position:0% +So that it's a soup of of such + + + align:start position:0% +So that it's a soup of of such +elements in capital B means that there + + align:start position:0% +elements in capital B means that there + + + align:start position:0% +elements in capital B means that there +exists a sequence + + align:start position:0% +exists a sequence + + + align:start position:0% +exists a sequence +of elements + + align:start position:0% +of elements + + + align:start position:0% +of elements +in B. + + align:start position:0% +in B. + + + align:start position:0% +in B. +So, so that y here y0 + + align:start position:0% +So, so that y here y0 + + + align:start position:0% +So, so that y here y0 +is the soup of b. This here implies that + + align:start position:0% +is the soup of b. This here implies that + + + align:start position:0% +is the soup of b. This here implies that +there exist a sequence y + + align:start position:0% +there exist a sequence y + + + align:start position:0% +there exist a sequence y +and these yn + + align:start position:0% +and these yn + + + align:start position:0% +and these yn +are in a and you have that + + align:start position:0% +are in a and you have that + + + align:start position:0% +are in a and you have that +x0 + + align:start position:0% +x0 + + + align:start position:0% +x0 +y + + align:start position:0% +y + + + align:start position:0% +y +is contained in a and and then you have + + align:start position:0% +is contained in a and and then you have + + + align:start position:0% +is contained in a and and then you have +that these guys converge to y z. + + align:start position:0% +that these guys converge to y z. + + + align:start position:0% +that these guys converge to y z. +Right? This is what you get from that is + + align:start position:0% +Right? This is what you get from that is + + + align:start position:0% +Right? This is what you get from that is +a soup. Right? These two things are that + + align:start position:0% +a soup. Right? These two things are that + + + align:start position:0% +a soup. Right? These two things are that +the elements + + align:start position:0% +the elements + + + align:start position:0% +the elements +are in that these elements. So this here + + align:start position:0% +are in that these elements. So this here + + + align:start position:0% +are in that these elements. So this here +is just that's the y in on b. + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% + + + + align:start position:0% + +So now what you have so this here means + + align:start position:0% +So now what you have so this here means + + + align:start position:0% +So now what you have so this here means +so here I have x0 + + align:start position:0% +so here I have x0 + + + align:start position:0% +so here I have x0 +here I have y z and I have these uh + + align:start position:0% +here I have y z and I have these uh + + + align:start position:0% +here I have y z and I have these uh +these elements + + align:start position:0% +these elements + + + align:start position:0% +these elements +y in + + align:start position:0% +y in + + + align:start position:0% +y in +and they are in particular they are in a + + align:start position:0% +and they are in particular they are in a + + + align:start position:0% +and they are in particular they are in a +okay but a is closed right since a is + + align:start position:0% +okay but a is closed right since a is + + + align:start position:0% +okay but a is closed right since a is +closed since + + align:start position:0% +closed since + + + align:start position:0% +closed since +y is in a + + align:start position:0% +y is in a + + + align:start position:0% +y is in a +and + + align:start position:0% +and + + + align:start position:0% +and +Y in and a is closed + + align:start position:0% +Y in and a is closed + + + align:start position:0% +Y in and a is closed +is a closed + + align:start position:0% +is a closed + + + align:start position:0% +is a closed +is a closed subset. + + align:start position:0% +is a closed subset. + + + align:start position:0% +is a closed subset. +This means that that the limit here the + + align:start position:0% +This means that that the limit here the + + + align:start position:0% +This means that that the limit here the +limit y z which is the limit this here + + align:start position:0% +limit y z which is the limit this here + + + align:start position:0% +limit y z which is the limit this here +must also be in a right. + + align:start position:0% +must also be in a right. + + + align:start position:0% +must also be in a right. +Okay. So we have proven the first + + align:start position:0% +Okay. So we have proven the first + + + align:start position:0% +Okay. So we have proven the first +property right + + align:start position:0% + + + + align:start position:0% + +we proven that that right so well so + + align:start position:0% +we proven that that right so well so + + + align:start position:0% +we proven that that right so well so +we've proven that y0 is in a but now you + + align:start position:0% +we've proven that y0 is in a but now you + + + align:start position:0% +we've proven that y0 is in a but now you +see that we have that for each of the y + + align:start position:0% +see that we have that for each of the y + + + align:start position:0% +see that we have that for each of the y +in we have that this interval here lie + + align:start position:0% +in we have that this interval here lie + + + align:start position:0% +in we have that this interval here lie +in a right and they converge to this so + + align:start position:0% +in a right and they converge to this so + + + align:start position:0% +in a right and they converge to this so +it means that if you take anything to + + align:start position:0% +it means that if you take anything to + + + align:start position:0% +it means that if you take anything to +the left + + align:start position:0% +the left + + + align:start position:0% +the left +of y0. Well, then eventually there's + + align:start position:0% +of y0. Well, then eventually there's + + + align:start position:0% +of y0. Well, then eventually there's +some y in to the right of that and so + + align:start position:0% +some y in to the right of that and so + + + align:start position:0% +some y in to the right of that and so +this whole interval is in a right. So + + align:start position:0% +this whole interval is in a right. So + + + align:start position:0% +this whole interval is in a right. So +you see that this it now means that not + + align:start position:0% +you see that this it now means that not + + + align:start position:0% +you see that this it now means that not +only is y z in a but y z is really in + + align:start position:0% +only is y z in a but y z is really in + + + align:start position:0% +only is y z in a but y z is really in +the set b. + + align:start position:0% +the set b. + + + align:start position:0% +the set b. +Okay, + + align:start position:0% + + + + align:start position:0% + +this here only used that A was closed, + + align:start position:0% +this here only used that A was closed, + + + align:start position:0% +this here only used that A was closed, +right? + + align:start position:0% +right? + + + align:start position:0% +right? +So now we need to use that A is open, + + align:start position:0% +So now we need to use that A is open, + + + align:start position:0% +So now we need to use that A is open, +right? + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +So now + + align:start position:0% +So now + + + align:start position:0% +So now +suppose we take a element + + align:start position:0% +suppose we take a element + + + align:start position:0% +suppose we take a element +suppose. So now here we have x0 + + align:start position:0% + + + + align:start position:0% + +we have here b and we want to show that + + align:start position:0% +we have here b and we want to show that + + + align:start position:0% +we have here b and we want to show that +this y0 we define to be the soup of this + + align:start position:0% +this y0 we define to be the soup of this + + + align:start position:0% +this y0 we define to be the soup of this +set capital b. We want to prove that + + align:start position:0% +set capital b. We want to prove that + + + align:start position:0% +set capital b. We want to prove that +this thing here is in fact y zero. + + align:start position:0% +this thing here is in fact y zero. + + + align:start position:0% +this thing here is in fact y zero. +Right? + + align:start position:0% +Right? + + + align:start position:0% +Right? +Suppose not suppose that suppose not. So + + align:start position:0% +Suppose not suppose that suppose not. So + + + align:start position:0% +Suppose not suppose that suppose not. So +suppose that you have here strictly + + align:start position:0% +suppose that you have here strictly + + + align:start position:0% +suppose that you have here strictly +between these two this here is y z + + align:start position:0% + + + + align:start position:0% + +now we already know that y0 + + align:start position:0% +now we already know that y0 + + + align:start position:0% +now we already know that y0 +is in a. This is what we proved here. + + align:start position:0% +is in a. This is what we proved here. + + + align:start position:0% +is in a. This is what we proved here. +Right? + + align:start position:0% +Right? + + + align:start position:0% +Right? +So but since since + + align:start position:0% +So but since since + + + align:start position:0% +So but since since +um uh a here is open + + align:start position:0% +um uh a here is open + + + align:start position:0% +um uh a here is open +there exist some tiny little interval + + align:start position:0% +there exist some tiny little interval + + + align:start position:0% +there exist some tiny little interval +there exist + + align:start position:0% + + + + align:start position:0% + +some interval here + + align:start position:0% +some interval here + + + align:start position:0% +some interval here +around this y z. So if you take y z and + + align:start position:0% +around this y z. So if you take y z and + + + align:start position:0% +around this y z. So if you take y z and +you subtract this epsilon + + align:start position:0% +you subtract this epsilon + + + align:start position:0% +you subtract this epsilon +so there exists some epsilon greater + + align:start position:0% +so there exists some epsilon greater + + + align:start position:0% +so there exists some epsilon greater +than zero. So that if you're looking at + + align:start position:0% +than zero. So that if you're looking at + + + align:start position:0% +than zero. So that if you're looking at +this tiny little interval centered at y + + align:start position:0% +this tiny little interval centered at y + + + align:start position:0% +this tiny little interval centered at y +z + + align:start position:0% + + + + align:start position:0% + +then this here is contained in a. This + + align:start position:0% +then this here is contained in a. This + + + align:start position:0% +then this here is contained in a. This +is just because a was open right. + + align:start position:0% +is just because a was open right. + + + align:start position:0% +is just because a was open right. +But this means that that now you have + + align:start position:0% +But this means that that now you have + + + align:start position:0% +But this means that that now you have +that. So this here is you assume this is + + align:start position:0% +that. So this here is you assume this is + + + align:start position:0% +that. So this here is you assume this is +y z. So you have that this thing here + + align:start position:0% +y z. So you have that this thing here + + + align:start position:0% +y z. So you have that this thing here +lie in the set capital A and this here I + + align:start position:0% +lie in the set capital A and this here I + + + align:start position:0% +lie in the set capital A and this here I +guarantee you that you can actually go a + + align:start position:0% +guarantee you that you can actually go a + + + align:start position:0% +guarantee you that you can actually go a +little bit past it right that even if + + align:start position:0% +little bit past it right that even if + + + align:start position:0% +little bit past it right that even if +you go a little bit past it if you go a + + align:start position:0% +you go a little bit past it if you go a + + + align:start position:0% +you go a little bit past it if you go a +little bit past it here then these are + + align:start position:0% +little bit past it here then these are + + + align:start position:0% +little bit past it here then these are +still in A right so this means that this + + align:start position:0% +still in A right so this means that this + + + align:start position:0% +still in A right so this means that this +could not be the soup right so therefore + + align:start position:0% +could not be the soup right so therefore + + + align:start position:0% +could not be the soup right so therefore +this point here had to be B right it had + + align:start position:0% +this point here had to be B right it had + + + align:start position:0% +this point here had to be B right it had +to be the final point. + + align:start position:0% +to be the final point. + + + align:start position:0% +to be the final point. +Okay, so this proved these two property, + + align:start position:0% +Okay, so this proved these two property, + + + align:start position:0% +Okay, so this proved these two property, +right? And so once you have these two + + align:start position:0% +right? And so once you have these two + + + align:start position:0% +right? And so once you have these two +property, you have that the interval is + + align:start position:0% +property, you have that the interval is + + + align:start position:0% +property, you have that the interval is +connected, right? That the only non-enty + + align:start position:0% +connected, right? That the only non-enty + + + align:start position:0% +connected, right? That the only non-enty +subset of the interval that is both open + + align:start position:0% +subset of the interval that is both open + + + align:start position:0% +subset of the interval that is both open +and closed is itself. Okay. + + align:start position:0% +and closed is itself. Okay. + + + align:start position:0% +and closed is itself. Okay. +Now why is this related to what we want? + + align:start position:0% +Now why is this related to what we want? + + + align:start position:0% +Now why is this related to what we want? +So this is just so we have + + align:start position:0% +So this is just so we have + + + align:start position:0% +So this is just so we have +suppose you take two functions. + + align:start position:0% + + + + align:start position:0% + +So why is this related to the uniqueness + + align:start position:0% +So why is this related to the uniqueness + + + align:start position:0% +So why is this related to the uniqueness +for the OD? + + align:start position:0% +for the OD? + + + align:start position:0% +for the OD? +So this is the following lema. + + align:start position:0% + + + + align:start position:0% + +Suppose you have a interval. So this is + + align:start position:0% +Suppose you have a interval. So this is + + + align:start position:0% +Suppose you have a interval. So this is +a interval + + align:start position:0% +a interval + + + align:start position:0% +a interval +in R and suppose you have two functions + + align:start position:0% +in R and suppose you have two functions + + + align:start position:0% +in R and suppose you have two functions +U1 and U2 + + align:start position:0% +U1 and U2 + + + align:start position:0% +U1 and U2 +they're functions on the interval + + align:start position:0% +they're functions on the interval + + + align:start position:0% +they're functions on the interval +and they are both continuous + + align:start position:0% + + + + align:start position:0% + +and then assume that for some assume + + align:start position:0% + + + + align:start position:0% + +that + + align:start position:0% +that + + + align:start position:0% +that +for some X0 0 + + align:start position:0% +for some X0 0 + + + align:start position:0% +for some X0 0 +in the interval + + align:start position:0% +in the interval + + + align:start position:0% +in the interval +uh u 1 of x0 is equal to u2 of x0. So + + align:start position:0% +uh u 1 of x0 is equal to u2 of x0. So + + + align:start position:0% +uh u 1 of x0 is equal to u2 of x0. So +they coincide in one point. + + align:start position:0% + + + + align:start position:0% + +And assume you have a second condition. + + align:start position:0% +And assume you have a second condition. + + + align:start position:0% +And assume you have a second condition. +And the second condition is + + align:start position:0% +And the second condition is + + + align:start position:0% +And the second condition is +that if + + align:start position:0% +that if + + + align:start position:0% +that if +uh if u + + align:start position:0% +uh if u + + + align:start position:0% +uh if u +uh of u1 of x is equal to u2 + + align:start position:0% +uh of u1 of x is equal to u2 + + + align:start position:0% +uh of u1 of x is equal to u2 +of x then there exist + + align:start position:0% + + + + align:start position:0% + +there exist + + align:start position:0% +there exist + + + align:start position:0% +there exist +a neighborhood so a epsilon + + align:start position:0% +a neighborhood so a epsilon + + + align:start position:0% +a neighborhood so a epsilon +where this is allowed. not to depend on + + align:start position:0% +where this is allowed. not to depend on + + + align:start position:0% +where this is allowed. not to depend on +x. + + align:start position:0% +x. + + + align:start position:0% +x. +So that uh u 1 is equal to u2 in not + + align:start position:0% +So that uh u 1 is equal to u2 in not + + + align:start position:0% +So that uh u 1 is equal to u2 in not +just at x but actually uh on this little + + align:start position:0% +just at x but actually uh on this little + + + align:start position:0% +just at x but actually uh on this little +interval x minus epsilon x + epsilon. + + align:start position:0% +interval x minus epsilon x + epsilon. + + + align:start position:0% +interval x minus epsilon x + epsilon. +Okay. So you have these two properties. + + align:start position:0% +Okay. So you have these two properties. + + + align:start position:0% +Okay. So you have these two properties. +So you have two continuous functions on + + align:start position:0% +So you have two continuous functions on + + + align:start position:0% +So you have two continuous functions on +an interval. They agree at one point and + + align:start position:0% +an interval. They agree at one point and + + + align:start position:0% +an interval. They agree at one point and +if they agree at any point in this + + align:start position:0% +if they agree at any point in this + + + align:start position:0% +if they agree at any point in this +interval then they agree on a little + + align:start position:0% +interval then they agree on a little + + + align:start position:0% +interval then they agree on a little +neighborhood of that point. Okay. But + + align:start position:0% +neighborhood of that point. Okay. But + + + align:start position:0% +neighborhood of that point. Okay. But +the neighborhood may depend on the + + align:start position:0% +the neighborhood may depend on the + + + align:start position:0% +the neighborhood may depend on the +point. Okay. And then the statement is + + align:start position:0% +point. Okay. And then the statement is + + + align:start position:0% +point. Okay. And then the statement is +so the claim is that + + align:start position:0% + + + + align:start position:0% + +that U1 + + align:start position:0% +that U1 + + + align:start position:0% +that U1 +is actually equal to U2 everywhere. + + align:start position:0% + + + + align:start position:0% + +in in the interval where they defined. + + align:start position:0% +in in the interval where they defined. + + + align:start position:0% +in in the interval where they defined. +Okay, that's a claim. Okay. And so now + + align:start position:0% +Okay, that's a claim. Okay. And so now + + + align:start position:0% +Okay, that's a claim. Okay. And so now +you see that if you take + + align:start position:0% + + + + align:start position:0% + +if you're looking at so the proof of + + align:start position:0% +if you're looking at so the proof of + + + align:start position:0% +if you're looking at so the proof of +this is + + align:start position:0% +this is + + + align:start position:0% +this is +that suppose so proof + + align:start position:0% + + + + align:start position:0% + +suppose you define a function + + align:start position:0% + + + + align:start position:0% + +uh and this function here is u1 of x + + align:start position:0% +uh and this function here is u1 of x + + + align:start position:0% +uh and this function here is u1 of x +minus u2 of x. If you define it like + + align:start position:0% +minus u2 of x. If you define it like + + + align:start position:0% +minus u2 of x. If you define it like +this, u1 and u2 are continuous. So f + + align:start position:0% +this, u1 and u2 are continuous. So f + + + align:start position:0% +this, u1 and u2 are continuous. So f +here is continuous. + + align:start position:0% + + + + align:start position:0% + +You also have that f of x0. Well, this + + align:start position:0% +You also have that f of x0. Well, this + + + align:start position:0% +You also have that f of x0. Well, this +is u1 of x0 minus u2 of x0. + + align:start position:0% +is u1 of x0 minus u2 of x0. + + + align:start position:0% +is u1 of x0 minus u2 of x0. +And these two function coincided at x0. + + align:start position:0% +And these two function coincided at x0. + + + align:start position:0% +And these two function coincided at x0. +So this is zero. + + align:start position:0% +So this is zero. + + + align:start position:0% +So this is zero. +You also have that if f ofx + + align:start position:0% +You also have that if f ofx + + + align:start position:0% +You also have that if f ofx +so if f of x is equal to zero. + + align:start position:0% +so if f of x is equal to zero. + + + align:start position:0% +so if f of x is equal to zero. +Well + + align:start position:0% + + + + align:start position:0% + +right now then then you have by this + + align:start position:0% +right now then then you have by this + + + align:start position:0% +right now then then you have by this +second property here this property here. + + align:start position:0% +second property here this property here. + + + align:start position:0% +second property here this property here. +So if f is zero this is just meaning + + align:start position:0% +So if f is zero this is just meaning + + + align:start position:0% +So if f is zero this is just meaning +that the two function coincided at that + + align:start position:0% +that the two function coincided at that + + + align:start position:0% +that the two function coincided at that +x just means that there exist they exist + + align:start position:0% +x just means that there exist they exist + + + align:start position:0% +x just means that there exist they exist +a delta + + align:start position:0% +a delta + + + align:start position:0% +a delta +epsilon sorry epsilon greater than zero + + align:start position:0% +epsilon sorry epsilon greater than zero + + + align:start position:0% +epsilon sorry epsilon greater than zero +such that + + align:start position:0% +such that + + + align:start position:0% +such that +uh f + + align:start position:0% +uh f + + + align:start position:0% +uh f +um of um of y is equal to zero in this + + align:start position:0% +um of um of y is equal to zero in this + + + align:start position:0% +um of um of y is equal to zero in this +little + + align:start position:0% + + + + align:start position:0% + +interval around + + align:start position:0% +interval around + + + align:start position:0% +interval around +X and so you have that + + align:start position:0% +X and so you have that + + + align:start position:0% +X and so you have that +and now I claim that so now the claim is + + align:start position:0% +and now I claim that so now the claim is + + + align:start position:0% +and now I claim that so now the claim is +that the zero set so the set where the + + align:start position:0% +that the zero set so the set where the + + + align:start position:0% +that the zero set so the set where the +function f is zero this is both open and + + align:start position:0% +function f is zero this is both open and + + + align:start position:0% +function f is zero this is both open and +closed. + + align:start position:0% +closed. + + + align:start position:0% +closed. +So the claim here is + + align:start position:0% + + + + align:start position:0% + +that that the set + + align:start position:0% +that that the set + + + align:start position:0% +that that the set +u capital a + + align:start position:0% +u capital a + + + align:start position:0% +u capital a +this is the set of x in the interval + + align:start position:0% +this is the set of x in the interval + + + align:start position:0% +this is the set of x in the interval +where f of x is equal to zero + + align:start position:0% +where f of x is equal to zero + + + align:start position:0% +where f of x is equal to zero +that this here is both + + align:start position:0% +that this here is both + + + align:start position:0% +that this here is both +open and closed. + + align:start position:0% + + + + align:start position:0% + +Right? We already know that this set + + align:start position:0% +Right? We already know that this set + + + align:start position:0% +Right? We already know that this set +this is follow up here that that x0 is + + align:start position:0% +this is follow up here that that x0 is + + + align:start position:0% +this is follow up here that that x0 is +so since + + align:start position:0% +so since + + + align:start position:0% +so since +since x0 is in this set then we have and + + align:start position:0% +since x0 is in this set then we have and + + + align:start position:0% +since x0 is in this set then we have and +the integral is connected and + + align:start position:0% +the integral is connected and + + + align:start position:0% +the integral is connected and +I is connected. + + align:start position:0% + + + + align:start position:0% + +If this set is both open and closed, + + align:start position:0% +If this set is both open and closed, + + + align:start position:0% +If this set is both open and closed, +then we have that then uh a is equal to + + align:start position:0% +then we have that then uh a is equal to + + + align:start position:0% +then we have that then uh a is equal to +the whole interval. Right? So this means + + align:start position:0% +the whole interval. Right? So this means + + + align:start position:0% +the whole interval. Right? So this means +that the that f is constant zero which + + align:start position:0% +that the that f is constant zero which + + + align:start position:0% +that the that f is constant zero which +means that the two functions coincided + + align:start position:0% +means that the two functions coincided + + + align:start position:0% +means that the two functions coincided +everywhere. Right? And so we just need + + align:start position:0% +everywhere. Right? And so we just need + + + align:start position:0% +everywhere. Right? And so we just need +to prove that f is + + align:start position:0% +to prove that f is + + + align:start position:0% +to prove that f is +both uh open and closed. But the zero + + align:start position:0% +both uh open and closed. But the zero + + + align:start position:0% +both uh open and closed. But the zero +set if you take a continuous function + + align:start position:0% +set if you take a continuous function + + + align:start position:0% +set if you take a continuous function +right. So if if f here is continuous + + align:start position:0% + + + + align:start position:0% + +and you have a sequence + + align:start position:0% +and you have a sequence + + + align:start position:0% +and you have a sequence +so that each element here in the + + align:start position:0% +so that each element here in the + + + align:start position:0% +so that each element here in the +sequence is zero and these xn converts + + align:start position:0% +sequence is zero and these xn converts + + + align:start position:0% +sequence is zero and these xn converts +to some x. Well then by continuity right + + align:start position:0% +to some x. Well then by continuity right + + + align:start position:0% +to some x. Well then by continuity right +by by continuity + + align:start position:0% +by by continuity + + + align:start position:0% +by by continuity +f of x would also be zero. This is by + + align:start position:0% +f of x would also be zero. This is by + + + align:start position:0% +f of x would also be zero. This is by +continuity + + align:start position:0% +continuity + + + align:start position:0% +continuity +right we already + + align:start position:0% + + + + align:start position:0% + +so this means that this set here is + + align:start position:0% +so this means that this set here is + + + align:start position:0% +so this means that this set here is +definitely closed right and the open + + align:start position:0% +definitely closed right and the open + + + align:start position:0% +definitely closed right and the open +thing with the open is just exactly this + + align:start position:0% +thing with the open is just exactly this + + + align:start position:0% +thing with the open is just exactly this +property that we're assuming that if you + + align:start position:0% +property that we're assuming that if you + + + align:start position:0% +property that we're assuming that if you +have an element in it each element is + + align:start position:0% +have an element in it each element is + + + align:start position:0% +have an element in it each element is +interior which means that there is this + + align:start position:0% +interior which means that there is this + + + align:start position:0% +interior which means that there is this +little interval around it right so you + + align:start position:0% +little interval around it right so you + + + align:start position:0% +little interval around it right so you +have we have proven that it's both uh + + align:start position:0% +have we have proven that it's both uh + + + align:start position:0% +have we have proven that it's both uh +closed. We prove that first and also + + align:start position:0% +closed. We prove that first and also + + + align:start position:0% +closed. We prove that first and also +open. And so we have that that if you + + align:start position:0% +open. And so we have that that if you + + + align:start position:0% +open. And so we have that that if you +have two such function + + align:start position:0% +have two such function + + + align:start position:0% +have two such function +defined both continuous and defined on + + align:start position:0% +defined both continuous and defined on + + + align:start position:0% +defined both continuous and defined on +an interval they coincide at one point + + align:start position:0% +an interval they coincide at one point + + + align:start position:0% +an interval they coincide at one point +and if they coincide at one point then + + align:start position:0% +and if they coincide at one point then + + + align:start position:0% +and if they coincide at one point then +they coincide in a little neighborhood. + + align:start position:0% +they coincide in a little neighborhood. + + + align:start position:0% +they coincide in a little neighborhood. +If you have two function with this + + align:start position:0% +If you have two function with this + + + align:start position:0% +If you have two function with this +property then they must be equal in the + + align:start position:0% +property then they must be equal in the + + + align:start position:0% +property then they must be equal in the +whole interval. Right? Okay. So now how + + align:start position:0% +whole interval. Right? Okay. So now how + + + align:start position:0% +whole interval. Right? Okay. So now how +does this relate to the the uniqueness + + align:start position:0% +does this relate to the the uniqueness + + + align:start position:0% +does this relate to the the uniqueness +that we wanted to prove? + + align:start position:0% + + + + align:start position:0% + +So we're starting again. So we have the + + align:start position:0% +So we're starting again. So we have the + + + align:start position:0% +So we're starting again. So we have the +so we have so this is again the picard + + align:start position:0% +so we have so this is again the picard + + + align:start position:0% +so we have so this is again the picard +linder theorem and this is the + + align:start position:0% +linder theorem and this is the + + + align:start position:0% +linder theorem and this is the +uniqueness part. + + align:start position:0% + + + + align:start position:0% + +And so you're looking at again you're + + align:start position:0% +And so you're looking at again you're + + + align:start position:0% +And so you're looking at again you're +looking at solutions + + align:start position:0% +looking at solutions + + + align:start position:0% +looking at solutions +to to this OD. + + align:start position:0% + + + + align:start position:0% + +Um and we have that now we had that um + + align:start position:0% +Um and we have that now we had that um + + + align:start position:0% +Um and we have that now we had that um +in a we have that in a so and then we + + align:start position:0% +in a we have that in a so and then we + + + align:start position:0% +in a we have that in a so and then we +let sorry and let y1 + + align:start position:0% +let sorry and let y1 + + + align:start position:0% +let sorry and let y1 +and y2 be solutions + + align:start position:0% + + + + align:start position:0% + +and let's say that these two they may be + + align:start position:0% +and let's say that these two they may be + + + align:start position:0% +and let's say that these two they may be +defined on different interval of course + + align:start position:0% +defined on different interval of course + + + align:start position:0% +defined on different interval of course +you know but but you just take the + + align:start position:0% +you know but but you just take the + + + align:start position:0% +you know but but you just take the +intersection of the two intervals that + + align:start position:0% +intersection of the two intervals that + + + align:start position:0% +intersection of the two intervals that +they're defined. So suppose that they're + + align:start position:0% +they're defined. So suppose that they're + + + align:start position:0% +they're defined. So suppose that they're +both defined say on the same interval + + align:start position:0% + + + + align:start position:0% + +like this + + align:start position:0% +like this + + + align:start position:0% +like this +and this interval here and I of course + + align:start position:0% +and this interval here and I of course + + + align:start position:0% +and this interval here and I of course +has to include the zero where we want + + align:start position:0% +has to include the zero where we want + + + align:start position:0% +has to include the zero where we want +this condition. + + align:start position:0% +this condition. + + + align:start position:0% +this condition. +Well then we have what do we have? So we + + align:start position:0% +Well then we have what do we have? So we + + + align:start position:0% +Well then we have what do we have? So we +have a interval and we have two + + align:start position:0% +have a interval and we have two + + + align:start position:0% +have a interval and we have two +continuous functions. They're actually + + align:start position:0% +continuous functions. They're actually + + + align:start position:0% +continuous functions. They're actually +better than continuous. They're + + align:start position:0% +better than continuous. They're + + + align:start position:0% +better than continuous. They're +differentiable + + align:start position:0% +differentiable + + + align:start position:0% +differentiable +and even the derivative is continuous. + + align:start position:0% +and even the derivative is continuous. + + + align:start position:0% +and even the derivative is continuous. +But but never mind that. Uh we have that + + align:start position:0% +But but never mind that. Uh we have that + + + align:start position:0% +But but never mind that. Uh we have that +we have that y1 of zero is equal to a + + align:start position:0% +we have that y1 of zero is equal to a + + + align:start position:0% +we have that y1 of zero is equal to a +and that's equal to y2 of zero. So they + + align:start position:0% +and that's equal to y2 of zero. So they + + + align:start position:0% +and that's equal to y2 of zero. So they +coincide at one point. + + align:start position:0% +coincide at one point. + + + align:start position:0% +coincide at one point. +And now the you the Picard Lindelof + + align:start position:0% +And now the you the Picard Lindelof + + + align:start position:0% +And now the you the Picard Lindelof +theorem said that because there were two + + align:start position:0% +theorem said that because there were two + + + align:start position:0% +theorem said that because there were two +solutions if you restrict the interval + + align:start position:0% +solutions if you restrict the interval + + + align:start position:0% +solutions if you restrict the interval +right to looking at this little interval + + align:start position:0% +right to looking at this little interval + + + align:start position:0% +right to looking at this little interval +around zero but then there was a unique + + align:start position:0% +around zero but then there was a unique + + + align:start position:0% +around zero but then there was a unique +fixed point right so it means that in a + + align:start position:0% +fixed point right so it means that in a + + + align:start position:0% +fixed point right so it means that in a +small neighborhood + + align:start position:0% +small neighborhood + + + align:start position:0% +small neighborhood +of the origin so two in a small + + align:start position:0% + + + + align:start position:0% + +neighborhood + + align:start position:0% + + + + align:start position:0% + +of the + + align:start position:0% +of the + + + align:start position:0% +of the +origin. This is again this is thanks to + + align:start position:0% +origin. This is again this is thanks to + + + align:start position:0% +origin. This is again this is thanks to +that in the contracting mapping theorem + + align:start position:0% +that in the contracting mapping theorem + + + align:start position:0% +that in the contracting mapping theorem +you had a unique fixed point in a small + + align:start position:0% +you had a unique fixed point in a small + + + align:start position:0% +you had a unique fixed point in a small +neighborhood of the origin y1 + + align:start position:0% +neighborhood of the origin y1 + + + align:start position:0% +neighborhood of the origin y1 +is equal to y2 right but actually the + + align:start position:0% +is equal to y2 right but actually the + + + align:start position:0% +is equal to y2 right but actually the +pical line the argument would work at + + align:start position:0% +pical line the argument would work at + + + align:start position:0% +pical line the argument would work at +any other point right suppose you take + + align:start position:0% +any other point right suppose you take + + + align:start position:0% +any other point right suppose you take +any other point then you and you take a + + align:start position:0% +any other point then you and you take a + + + align:start position:0% +any other point then you and you take a +solution to the OD well if If you take + + align:start position:0% +solution to the OD well if If you take + + + align:start position:0% +solution to the OD well if If you take +another point then the value so suppose + + align:start position:0% +another point then the value so suppose + + + align:start position:0% +another point then the value so suppose +so so if you take so take you any other + + align:start position:0% +so so if you take so take you any other + + + align:start position:0% +so so if you take so take you any other +point so here you have zero + + align:start position:0% +point so here you have zero + + + align:start position:0% +point so here you have zero +and so now take any other points let's + + align:start position:0% +and so now take any other points let's + + + align:start position:0% +and so now take any other points let's +call it x0 + + align:start position:0% +call it x0 + + + align:start position:0% +call it x0 +and if you assume that these two + + align:start position:0% +and if you assume that these two + + + align:start position:0% +and if you assume that these two +functions coincide at this point so + + align:start position:0% +functions coincide at this point so + + + align:start position:0% +functions coincide at this point so +suppose that y1 + + align:start position:0% +suppose that y1 + + + align:start position:0% +suppose that y1 +of x0 is equal to y2 + + align:start position:0% +of x0 is equal to y2 + + + align:start position:0% +of x0 is equal to y2 +of x0. If you now restrict this + + align:start position:0% +of x0. If you now restrict this + + + align:start position:0% +of x0. If you now restrict this +interval, + + align:start position:0% +interval, + + + align:start position:0% +interval, +make it sufficiently small, then the + + align:start position:0% +make it sufficiently small, then the + + + align:start position:0% +make it sufficiently small, then the +argument of picard lindelof tells you + + align:start position:0% +argument of picard lindelof tells you + + + align:start position:0% +argument of picard lindelof tells you +that you had this unique fixed point. So + + align:start position:0% +that you had this unique fixed point. So + + + align:start position:0% +that you had this unique fixed point. So +you had a unique solution on this little + + align:start position:0% +you had a unique solution on this little + + + align:start position:0% +you had a unique solution on this little +interval. But since they coincide at + + align:start position:0% +interval. But since they coincide at + + + align:start position:0% +interval. But since they coincide at +this point, it means that they must be + + align:start position:0% +this point, it means that they must be + + + align:start position:0% +this point, it means that they must be +the same in this little interval. And so + + align:start position:0% +the same in this little interval. And so + + + align:start position:0% +the same in this little interval. And so +you see that now we have the condition + + align:start position:0% +you see that now we have the condition + + + align:start position:0% +you see that now we have the condition +for for the lema okay for the lema that + + align:start position:0% +for for the lema okay for the lema that + + + align:start position:0% +for for the lema okay for the lema that +said that so you have these two + + align:start position:0% +said that so you have these two + + + align:start position:0% +said that so you have these two +continuous function and they were equal + + align:start position:0% +continuous function and they were equal + + + align:start position:0% +continuous function and they were equal +at one point and if they're equal at a + + align:start position:0% +at one point and if they're equal at a + + + align:start position:0% +at one point and if they're equal at a +point then they're equal in a whole + + align:start position:0% +point then they're equal in a whole + + + align:start position:0% +point then they're equal in a whole +neighborhood. Okay so these two + + align:start position:0% +neighborhood. Okay so these two + + + align:start position:0% +neighborhood. Okay so these two +functions these two solutions are equal + + align:start position:0% +functions these two solutions are equal + + + align:start position:0% +functions these two solutions are equal +on the on the interval where they're + + align:start position:0% +on the on the interval where they're + + + align:start position:0% +on the on the interval where they're +both defined. Okay. + + align:start position:0% +both defined. Okay. + + + align:start position:0% +both defined. Okay. +Now Okay. Okay. So now you might and and + + align:start position:0% +Now Okay. Okay. So now you might and and + + + align:start position:0% +Now Okay. Okay. So now you might and and +then I want to do a little bit of review + + align:start position:0% +then I want to do a little bit of review + + + align:start position:0% +then I want to do a little bit of review +at the end. So at least say something + + align:start position:0% +at the end. So at least say something + + + align:start position:0% +at the end. So at least say something +about the the final. But before we get + + align:start position:0% +about the the final. But before we get + + + align:start position:0% +about the the final. But before we get +to that, let me just make one more + + align:start position:0% +to that, let me just make one more + + + align:start position:0% +to that, let me just make one more +observation + + align:start position:0% +observation + + + align:start position:0% +observation +about the picard line. + + align:start position:0% +about the picard line. + + + align:start position:0% +about the picard line. +So you may + + align:start position:0% +So you may + + + align:start position:0% +So you may +say that in the proof of the picard + + align:start position:0% +say that in the proof of the picard + + + align:start position:0% +say that in the proof of the picard +linder we kind of had to restrict the + + align:start position:0% +linder we kind of had to restrict the + + + align:start position:0% +linder we kind of had to restrict the +interval. Is that really necessary? Why + + align:start position:0% +interval. Is that really necessary? Why + + + align:start position:0% +interval. Is that really necessary? Why +should we restrict? Why should we only + + align:start position:0% +should we restrict? Why should we only + + + align:start position:0% +should we restrict? Why should we only +be able to say that we had a solution in + + align:start position:0% +be able to say that we had a solution in + + + align:start position:0% +be able to say that we had a solution in +a very small interval? And so if you're + + align:start position:0% +a very small interval? And so if you're + + + align:start position:0% +a very small interval? And so if you're +looking at the example, suppose you're + + align:start position:0% +looking at the example, suppose you're + + + align:start position:0% +looking at the example, suppose you're +looking at the example + + align:start position:0% +looking at the example + + + align:start position:0% +looking at the example +where y where f + + align:start position:0% +where y where f + + + align:start position:0% +where y where f +so f of y + + align:start position:0% +so f of y + + + align:start position:0% +so f of y +is equal to y 2 g of x is equal to zero. + + align:start position:0% +is equal to y 2 g of x is equal to zero. + + + align:start position:0% +is equal to y 2 g of x is equal to zero. +And so you're looking at the OD the + + align:start position:0% +And so you're looking at the OD the + + + align:start position:0% +And so you're looking at the OD the +solutions here y so that's uh y prime is + + align:start position:0% +solutions here y so that's uh y prime is + + + align:start position:0% +solutions here y so that's uh y prime is +equal to + + align:start position:0% +equal to + + + align:start position:0% +equal to +y 2 and uh let's say equal to a + + align:start position:0% +y 2 and uh let's say equal to a + + + align:start position:0% +y 2 and uh let's say equal to a +uh form + + align:start position:0% +uh form + + + align:start position:0% +uh form +uh x + + align:start position:0% +uh x + + + align:start position:0% +uh x +uh equal to x0 + + align:start position:0% +uh equal to x0 + + + align:start position:0% +uh equal to x0 +okay so suppose you're looking at a like + + align:start position:0% +okay so suppose you're looking at a like + + + align:start position:0% +okay so suppose you're looking at a like +this + + align:start position:0% +this + + + align:start position:0% +this +right so at this x0 you want the value + + align:start position:0% +right so at this x0 you want the value + + + align:start position:0% +right so at this x0 you want the value +of the function to be so you want sorry + + align:start position:0% +of the function to be so you want sorry + + + align:start position:0% +of the function to be so you want sorry +y of uh x0 + + align:start position:0% +y of uh x0 + + + align:start position:0% +y of uh x0 +uh equal to + + align:start position:0% +uh equal to + + + align:start position:0% +uh equal to +want maybe I should maybe this is a + + align:start position:0% +want maybe I should maybe this is a + + + align:start position:0% +want maybe I should maybe this is a +little bit bad notation so I want a a + + align:start position:0% +little bit bad notation so I want a a + + + align:start position:0% +little bit bad notation so I want a a +function so that y prime is equal to y^ + + align:start position:0% +function so that y prime is equal to y^ + + + align:start position:0% +function so that y prime is equal to y^ +2 and I want y of x0 = a Right. + + align:start position:0% + + + + align:start position:0% + +Okay. Now let's say that x0 + + align:start position:0% +Okay. Now let's say that x0 + + + align:start position:0% +Okay. Now let's say that x0 +and a are both positive. + + align:start position:0% +and a are both positive. + + + align:start position:0% +and a are both positive. +So if you're looking at this OD + + align:start position:0% +So if you're looking at this OD + + + align:start position:0% +So if you're looking at this OD +then + + align:start position:0% +then + + + align:start position:0% +then +then you can just this one here is easy + + align:start position:0% +then you can just this one here is easy + + + align:start position:0% +then you can just this one here is easy +to solve + + align:start position:0% +to solve + + + align:start position:0% +to solve +because you have a function + + align:start position:0% +because you have a function + + + align:start position:0% +because you have a function +you have a function y prime + + align:start position:0% +you have a function y prime + + + align:start position:0% +you have a function y prime +equal to y² + + align:start position:0% + + + + align:start position:0% + +and now let's try to find a solution in + + align:start position:0% +and now let's try to find a solution in + + + align:start position:0% +and now let's try to find a solution in +a neighborhood of x0 but there supposed + + align:start position:0% +a neighborhood of x0 but there supposed + + + align:start position:0% +a neighborhood of x0 but there supposed +to be positive. So in a small + + align:start position:0% +to be positive. So in a small + + + align:start position:0% +to be positive. So in a small +neighborhood it's positive. So I can + + align:start position:0% +neighborhood it's positive. So I can + + + align:start position:0% +neighborhood it's positive. So I can +divide by y^2. So I can looking at so + + align:start position:0% +divide by y^2. So I can looking at so + + + align:start position:0% +divide by y^2. So I can looking at so +this thing here is equivalent to that y + + align:start position:0% +this thing here is equivalent to that y + + + align:start position:0% +this thing here is equivalent to that y +prime over y^ 2 is equal to 1. + + align:start position:0% +prime over y^ 2 is equal to 1. + + + align:start position:0% +prime over y^ 2 is equal to 1. +And this thing here I can write as 1 / y + + align:start position:0% +And this thing here I can write as 1 / y + + + align:start position:0% +And this thing here I can write as 1 / y +prime * -1. this thing here, if you're + + align:start position:0% +prime * -1. this thing here, if you're + + + align:start position:0% +prime * -1. this thing here, if you're +looking at this function here by the + + align:start position:0% +looking at this function here by the + + + align:start position:0% +looking at this function here by the +chain rule, it's equal to that, right? + + align:start position:0% +chain rule, it's equal to that, right? + + + align:start position:0% +chain rule, it's equal to that, right? +And so this means that now you can apply + + align:start position:0% +And so this means that now you can apply + + + align:start position:0% +And so this means that now you can apply +the fundamental theorem of calculus. And + + align:start position:0% +the fundamental theorem of calculus. And + + + align:start position:0% +the fundamental theorem of calculus. And +if you're integrating this function here + + align:start position:0% +if you're integrating this function here + + + align:start position:0% +if you're integrating this function here +and you're integrating it from + + align:start position:0% +and you're integrating it from + + + align:start position:0% +and you're integrating it from +uh two values uh x0 to x + + align:start position:0% +uh two values uh x0 to x + + + align:start position:0% +uh two values uh x0 to x +uh d + + align:start position:0% +uh d + + + align:start position:0% +uh d +uh uh d of s sorry this is the prime. + + align:start position:0% + + + + align:start position:0% + +Then what you get is that this thing + + align:start position:0% +Then what you get is that this thing + + + align:start position:0% +Then what you get is that this thing +here is equal to well on one hand by the + + align:start position:0% +here is equal to well on one hand by the + + + align:start position:0% +here is equal to well on one hand by the +fundamental theorem of calculus it's 1 / + + align:start position:0% +fundamental theorem of calculus it's 1 / + + + align:start position:0% +fundamental theorem of calculus it's 1 / +y of x minus and then there's a minus + + align:start position:0% +y of x minus and then there's a minus + + + align:start position:0% +y of x minus and then there's a minus +sign sorry this here because of this + + align:start position:0% +sign sorry this here because of this + + + align:start position:0% +sign sorry this here because of this +minus sign. So it's minus this plus 1 / + + align:start position:0% +minus sign. So it's minus this plus 1 / + + + align:start position:0% +minus sign. So it's minus this plus 1 / +y of x0 + + align:start position:0% +y of x0 + + + align:start position:0% +y of x0 +and on the other hand it's equal to this + + align:start position:0% +and on the other hand it's equal to this + + + align:start position:0% +and on the other hand it's equal to this +and when you're integrating this on this + + align:start position:0% +and when you're integrating this on this + + + align:start position:0% +and when you're integrating this on this +interval here so this also equal to x0 x + + align:start position:0% +interval here so this also equal to x0 x + + + align:start position:0% +interval here so this also equal to x0 x +um and then one d s this thing here is + + align:start position:0% +um and then one d s this thing here is + + + align:start position:0% +um and then one d s this thing here is +just x - x0 + + align:start position:0% +just x - x0 + + + align:start position:0% +just x - x0 +x - x0 + + align:start position:0% +x - x0 + + + align:start position:0% +x - x0 +okay So if you solve it then let me just + + align:start position:0% +okay So if you solve it then let me just + + + align:start position:0% +okay So if you solve it then let me just +write the result. If you check what this + + align:start position:0% +write the result. If you check what this + + + align:start position:0% +write the result. If you check what this +gives you, + + align:start position:0% +gives you, + + + align:start position:0% +gives you, +this gives you that um when you solve it + + align:start position:0% +this gives you that um when you solve it + + + align:start position:0% +this gives you that um when you solve it +like this, uh you're getting + + align:start position:0% +like this, uh you're getting + + + align:start position:0% +like this, uh you're getting +you're getting that y here is so you + + align:start position:0% +you're getting that y here is so you + + + align:start position:0% +you're getting that y here is so you +have this od here + + align:start position:0% +have this od here + + + align:start position:0% +have this od here +and you're assuming that these things + + align:start position:0% +and you're assuming that these things + + + align:start position:0% +and you're assuming that these things +here are positive and then the solutions + + align:start position:0% +here are positive and then the solutions + + + align:start position:0% +here are positive and then the solutions +are of the form y of x + + align:start position:0% +are of the form y of x + + + align:start position:0% +are of the form y of x += a over 1 + a + + align:start position:0% += a over 1 + a + + + align:start position:0% += a over 1 + a +uh x0 - x right + + align:start position:0% +uh x0 - x right + + + align:start position:0% +uh x0 - x right +and so what you should observe here is + + align:start position:0% +and so what you should observe here is + + + align:start position:0% +and so what you should observe here is +that this thing here right as this is + + align:start position:0% +that this thing here right as this is + + + align:start position:0% +that this thing here right as this is +not defined. So this is note + + align:start position:0% + + + + align:start position:0% + +that y is not defined + + align:start position:0% +that y is not defined + + + align:start position:0% +that y is not defined +uh + + align:start position:0% + + + + align:start position:0% + +on all of r. But instead as x here goes + + align:start position:0% +on all of r. But instead as x here goes + + + align:start position:0% +on all of r. But instead as x here goes +to uh x0 + + align:start position:0% +to uh x0 + + + align:start position:0% +to uh x0 +um + 1. + + align:start position:0% +um + 1. + + + align:start position:0% +um + 1. +As x0 goes to this, this thing here goes + + align:start position:0% +As x0 goes to this, this thing here goes + + + align:start position:0% +As x0 goes to this, this thing here goes +to minus one. So the denominator goes to + + align:start position:0% +to minus one. So the denominator goes to + + + align:start position:0% +to minus one. So the denominator goes to +zero. So the function blows up. Right? + + align:start position:0% +zero. So the function blows up. Right? + + + align:start position:0% +zero. So the function blows up. Right? +So this is so this here show you that it + + align:start position:0% +So this is so this here show you that it + + + align:start position:0% +So this is so this here show you that it +does in a neighborhood of this point. It + + align:start position:0% +does in a neighborhood of this point. It + + + align:start position:0% +does in a neighborhood of this point. It +has a solution but that neighborhood is + + align:start position:0% +has a solution but that neighborhood is + + + align:start position:0% +has a solution but that neighborhood is +not you know it's some relatively small + + align:start position:0% +not you know it's some relatively small + + + align:start position:0% +not you know it's some relatively small +neighborhoods and the function you + + align:start position:0% +neighborhoods and the function you + + + align:start position:0% +neighborhoods and the function you +cannot extend it past a you know past as + + align:start position:0% +cannot extend it past a you know past as + + + align:start position:0% +cannot extend it past a you know past as +a a certain value you can't extend it + + align:start position:0% +a a certain value you can't extend it + + + align:start position:0% +a a certain value you can't extend it +past in this case you can't extend it + + align:start position:0% +past in this case you can't extend it + + + align:start position:0% +past in this case you can't extend it +past this point here so to the left of + + align:start position:0% +past this point here so to the left of + + + align:start position:0% +past this point here so to the left of +this point + + align:start position:0% + + + + align:start position:0% + +to the sorry to the to the right I guess + + align:start position:0% +to the sorry to the to the right I guess + + + align:start position:0% +to the sorry to the to the right I guess +of that + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +Okay. So now I want to say a little bit + + align:start position:0% +Okay. So now I want to say a little bit + + + align:start position:0% +Okay. So now I want to say a little bit +about the the final. Yeah. Sorry. + + align:start position:0% +about the the final. Yeah. Sorry. + + + align:start position:0% +about the the final. Yeah. Sorry. +>> Why is it that you can't um once you + + align:start position:0% +>> Why is it that you can't um once you + + + align:start position:0% +>> Why is it that you can't um once you +reach that point where it blows up does + + align:start position:0% +reach that point where it blows up does + + + align:start position:0% +reach that point where it blows up does +it like it never solves differential + + align:start position:0% +it like it never solves differential + + + align:start position:0% +it like it never solves differential +equation past that point? + + align:start position:0% +equation past that point? + + + align:start position:0% +equation past that point? +>> Yeah, that's right. So so the thing is + + align:start position:0% +>> Yeah, that's right. So so the thing is + + + align:start position:0% +>> Yeah, that's right. So so the thing is +so + + align:start position:0% +so + + + align:start position:0% +so +so right. So this here this OD is going + + align:start position:0% +so right. So this here this OD is going + + + align:start position:0% +so right. So this here this OD is going +to force it to once this here once Y + + align:start position:0% +to force it to once this here once Y + + + align:start position:0% +to force it to once this here once Y +become large then why become really + + align:start position:0% +become large then why become really + + + align:start position:0% +become large then why become really +really large so it become large too + + align:start position:0% +really large so it become large too + + + align:start position:0% +really large so it become large too +quickly so it becomes quickly so that so + + align:start position:0% +quickly so it becomes quickly so that so + + + align:start position:0% +quickly so it becomes quickly so that so +it would give you some sort of OD like + + align:start position:0% +it would give you some sort of OD like + + + align:start position:0% +it would give you some sort of OD like +this that you have some critical value + + align:start position:0% +this that you have some critical value + + + align:start position:0% +this that you have some critical value +where you couldn't extend it past that + + align:start position:0% +where you couldn't extend it past that + + + align:start position:0% +where you couldn't extend it past that +because it is it will have like a a + + align:start position:0% +because it is it will have like a a + + + align:start position:0% +because it is it will have like a a +tangent that is that is going vertical + + align:start position:0% +tangent that is that is going vertical + + + align:start position:0% +tangent that is that is going vertical +like this. Okay. And + + align:start position:0% +like this. Okay. And + + + align:start position:0% +like this. Okay. And +>> so you can't So, so this means that + + align:start position:0% +>> so you can't So, so this means that + + + align:start position:0% +>> so you can't So, so this means that +there's, you know, that's right. So, so + + align:start position:0% +there's, you know, that's right. So, so + + + align:start position:0% +there's, you know, that's right. So, so +um but so, so you have a solution that + + align:start position:0% +um but so, so you have a solution that + + + align:start position:0% +um but so, so you have a solution that +exists on some interval, but it doesn't + + align:start position:0% +exists on some interval, but it doesn't + + + align:start position:0% +exists on some interval, but it doesn't +exist past this point. So, you can't + + align:start position:0% +exist past this point. So, you can't + + + align:start position:0% +exist past this point. So, you can't +have a solution, + + align:start position:0% +have a solution, + + + align:start position:0% +have a solution, +uh, you know, on some interval larger + + align:start position:0% +uh, you know, on some interval larger + + + align:start position:0% +uh, you know, on some interval larger +than than this to the left. and and this + + align:start position:0% +than than this to the left. and and this + + + align:start position:0% +than than this to the left. and and this +is probably a similar phenomena on the + + align:start position:0% +is probably a similar phenomena on the + + + align:start position:0% +is probably a similar phenomena on the +other side, right? + + align:start position:0% +other side, right? + + + align:start position:0% +other side, right? +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +But and it's like a kind of standard + + align:start position:0% +But and it's like a kind of standard + + + align:start position:0% +But and it's like a kind of standard +prop, you know, standard uh issue that + + align:start position:0% +prop, you know, standard uh issue that + + + align:start position:0% +prop, you know, standard uh issue that +for uh differential equations you can + + align:start position:0% +for uh differential equations you can + + + align:start position:0% +for uh differential equations you can +get blowups like this that that this is + + align:start position:0% +get blowups like this that that this is + + + align:start position:0% +get blowups like this that that this is +a particular simple examp. Any other + + align:start position:0% +a particular simple examp. Any other + + + align:start position:0% +a particular simple examp. Any other +questions? + + align:start position:0% + + + + align:start position:0% + +Um okay, great. \ No newline at end of file diff --git a/79GY-hI_emE.txt b/79GY-hI_emE.txt new file mode 100644 index 0000000000000000000000000000000000000000..46c4ee4176370b01bc39d2c898f0ab58bd64a6fe --- /dev/null +++ b/79GY-hI_emE.txt @@ -0,0 +1,659 @@ +align:start position:0% + +there's one more property of this thing + + align:start position:0% +there's one more property of this thing + + + align:start position:0% +there's one more property of this thing +that is important and it's something + + align:start position:0% +that is important and it's something + + + align:start position:0% +that is important and it's something +called the correspondence principle + + align:start position:0% +called the correspondence principle + + + align:start position:0% +called the correspondence principle +which is another classical intuition and + + align:start position:0% +which is another classical intuition and + + + align:start position:0% +which is another classical intuition and +it says that the wave function and it + + align:start position:0% +it says that the wave function and it + + + align:start position:0% +it says that the wave function and it +addresses the question of what happens + + align:start position:0% +addresses the question of what happens + + + align:start position:0% +addresses the question of what happens +to the amplitude of the wave function it + + align:start position:0% +to the amplitude of the wave function it + + + align:start position:0% +to the amplitude of the wave function it +says that the wave function should be + + align:start position:0% +says that the wave function should be + + + align:start position:0% +says that the wave function should be +larger in the regions where the particle + + align:start position:0% +larger in the regions where the particle + + + align:start position:0% +larger in the regions where the particle +spends more time so in this problem you + + align:start position:0% +spends more time so in this problem you + + + align:start position:0% +spends more time so in this problem you +have the particle going here it's + + align:start position:0% +have the particle going here it's + + + align:start position:0% +have the particle going here it's +bouncing and it's going slowly here it's + + align:start position:0% +bouncing and it's going slowly here it's + + + align:start position:0% +bouncing and it's going slowly here it's +going very fast here so it's very small + + align:start position:0% +going very fast here so it's very small + + + align:start position:0% +going very fast here so it's very small +time here spent a lot of time here + + align:start position:0% +time here spent a lot of time here + + + align:start position:0% +time here spent a lot of time here +spends a lot of time here so it should + + align:start position:0% +spends a lot of time here so it should + + + align:start position:0% +spends a lot of time here so it should +be bigger in this region and smaller in + + align:start position:0% +be bigger in this region and smaller in + + + align:start position:0% +be bigger in this region and smaller in +the regions that spends little time so + + align:start position:0% +the regions that spends little time so + + + align:start position:0% +the regions that spends little time so +this was folded correspondence principle + + align:start position:0% +this was folded correspondence principle + + + align:start position:0% +this was folded correspondence principle +which is a big name for a somewhat vague + + align:start position:0% +which is a big name for a somewhat vague + + + align:start position:0% +which is a big name for a somewhat vague +idea and but nevertheless is a + + align:start position:0% +idea and but nevertheless is a + + + align:start position:0% +idea and but nevertheless is a +interesting thing and it's true as well + + align:start position:0% +interesting thing and it's true as well + + + align:start position:0% +interesting thing and it's true as well +so let me explain this a little more and + + align:start position:0% +so let me explain this a little more and + + + align:start position:0% +so let me explain this a little more and +get the key point about this so we say + + align:start position:0% +get the key point about this so we say + + + align:start position:0% +get the key point about this so we say +if you have a potential of X and X plus + + align:start position:0% +if you have a potential of X and X plus + + + align:start position:0% +if you have a potential of X and X plus +B X this is the X the probability to be + + align:start position:0% +B X this is the X the probability to be + + + align:start position:0% +B X this is the X the probability to be +found in the X is equal to Y square DX + + align:start position:0% +found in the X is equal to Y square DX + + + align:start position:0% +found in the X is equal to Y square DX +and it's proportional to the darling + + align:start position:0% +and it's proportional to the darling + + + align:start position:0% +and it's proportional to the darling +spent there so we'll say that it's will + + align:start position:0% +spent there so we'll say that it's will + + + align:start position:0% +spent there so we'll say that it's will +write it in the following way it's + + align:start position:0% +write it in the following way it's + + + align:start position:0% +write it in the following way it's +proportional to the fraction of time + + align:start position:0% +proportional to the fraction of time + + + align:start position:0% +proportional to the fraction of time +spent in DX and that we will call the + + align:start position:0% +spent in DX and that we will call the + + + align:start position:0% +spent in DX and that we will call the +little T over the period of the motion + + align:start position:0% +little T over the period of the motion + + + align:start position:0% +little T over the period of the motion +in this oscillation the classical + + align:start position:0% +in this oscillation the classical + + + align:start position:0% +in this oscillation the classical +particle is doing that's a fraction of + + align:start position:0% +particle is doing that's a fraction of + + + align:start position:0% +particle is doing that's a fraction of +time it spends there up to factors of + + align:start position:0% +time it spends there up to factors of + + + align:start position:0% +time it spends there up to factors of +two maybe because spends more in there + + align:start position:0% +two maybe because spends more in there + + + align:start position:0% +two maybe because spends more in there +and therefore o period doesn't matter + + align:start position:0% +and therefore o period doesn't matter + + + align:start position:0% +and therefore o period doesn't matter +anyway approximate it's a classical + + align:start position:0% +anyway approximate it's a classical + + + align:start position:0% +anyway approximate it's a classical +intuition expressed with the + + align:start position:0% +intuition expressed with the + + + align:start position:0% +intuition expressed with the +correspondence principle so this is + + align:start position:0% +correspondence principle so this is + + + align:start position:0% +correspondence principle so this is +equal to DX over V over the velocity the + + align:start position:0% +equal to DX over V over the velocity the + + + align:start position:0% +equal to DX over V over the velocity the +position dependent velocity T and this + + align:start position:0% +position dependent velocity T and this + + + align:start position:0% +position dependent velocity T and this +is therefore VX and the velocity is P + + align:start position:0% +is therefore VX and the velocity is P + + + align:start position:0% +is therefore VX and the velocity is P +over N so the mass over period and the + + align:start position:0% +over N so the mass over period and the + + + align:start position:0% +over N so the mass over period and the +momentum so here we go here is the + + align:start position:0% +momentum so here we go here is the + + + align:start position:0% +momentum so here we go here is the +interesting thing we found that the + + align:start position:0% +interesting thing we found that the + + + align:start position:0% +interesting thing we found that the +magnitude of the wave function should be + + align:start position:0% +magnitude of the wave function should be + + + align:start position:0% +magnitude of the wave function should be +proportional to 1 over P of X or lambda + + align:start position:0% +proportional to 1 over P of X or lambda + + + align:start position:0% +proportional to 1 over P of X or lambda +over H bar so then the key result is the + + align:start position:0% +over H bar so then the key result is the + + + align:start position:0% +over H bar so then the key result is the +magnitude of the wave function goes like + + align:start position:0% +magnitude of the wave function goes like + + + align:start position:0% +magnitude of the wave function goes like +the square root of the position + + align:start position:0% +the square root of the position + + + align:start position:0% +the square root of the position +dependent the Broglie wavelength so if + + align:start position:0% +dependent the Broglie wavelength so if + + + align:start position:0% +dependent the Broglie wavelength so if +here + + align:start position:0% + + + + align:start position:0% + +then the broadly away from is becoming + + align:start position:0% +then the broadly away from is becoming + + + align:start position:0% +then the broadly away from is becoming +bigger because the momentum is becoming + + align:start position:0% +bigger because the momentum is becoming + + + align:start position:0% +bigger because the momentum is becoming +smaller the logic here says that yes + + align:start position:0% +smaller the logic here says that yes + + + align:start position:0% +smaller the logic here says that yes +indeed in here the particle is spending + + align:start position:0% +indeed in here the particle is spending + + + align:start position:0% +indeed in here the particle is spending +more time here so actually I should be + + align:start position:0% +more time here so actually I should be + + + align:start position:0% +more time here so actually I should be +drawing it a little bigger so when I try + + align:start position:0% +drawing it a little bigger so when I try + + + align:start position:0% +drawing it a little bigger so when I try +to sketch a wave function in a potential + + align:start position:0% +to sketch a wave function in a potential + + + align:start position:0% +to sketch a wave function in a potential +this is my best guess of how it would be + + align:start position:0% +this is my best guess of how it would be + + + align:start position:0% +this is my best guess of how it would be +and you will be doing a lot of numerical + + align:start position:0% +and you will be doing a lot of numerical + + + align:start position:0% +and you will be doing a lot of numerical +experimentation with Mathematica and get + + align:start position:0% +experimentation with Mathematica and get + + + align:start position:0% +experimentation with Mathematica and get +that kind of insight they pose position + + align:start position:0% +that kind of insight they pose position + + + align:start position:0% +that kind of insight they pose position +dependent the broad new wave length as + + align:start position:0% +dependent the broad new wave length as + + + align:start position:0% +dependent the broad new wave length as +you have it is is a function of the + + align:start position:0% +you have it is is a function of the + + + align:start position:0% +you have it is is a function of the +canary the local kinetic energy and + + align:start position:0% +canary the local kinetic energy and + + + align:start position:0% +canary the local kinetic energy and +that's what it gives for you okay so + + align:start position:0% +that's what it gives for you okay so + + + align:start position:0% +that's what it gives for you okay so +that is one key insight into the plot of + + align:start position:0% +that is one key insight into the plot of + + + align:start position:0% +that is one key insight into the plot of +the wave function without solving + + align:start position:0% +the wave function without solving + + + align:start position:0% +the wave function without solving +anything you can estimate how the wave + + align:start position:0% +anything you can estimate how the wave + + + align:start position:0% +anything you can estimate how the wave +length goes and probably to what degree + + align:start position:0% +length goes and probably to what degree + + + align:start position:0% +length goes and probably to what degree +the amplitude goes what else do you know + + align:start position:0% +the amplitude goes what else do you know + + + align:start position:0% +the amplitude goes what else do you know +there's a node theorem that we mentioned + + align:start position:0% +there's a node theorem that we mentioned + + + align:start position:0% +there's a node theorem that we mentioned +again in the case of the square well the + + align:start position:0% +again in the case of the square well the + + + align:start position:0% +again in the case of the square well the +ground state the bound state the ground + + align:start position:0% +ground state the bound state the ground + + + align:start position:0% +ground state the bound state the ground +state bound state is a state without a + + align:start position:0% +state bound state is a state without a + + + align:start position:0% +state bound state is a state without a +node the first excited state has one now + + align:start position:0% +node the first excited state has one now + + + align:start position:0% +node the first excited state has one now +that makes excited state has two nodes + + align:start position:0% +that makes excited state has two nodes + + + align:start position:0% +that makes excited state has two nodes +and that's three nodes and the number of + + align:start position:0% +and that's three nodes and the number of + + + align:start position:0% +and that's three nodes and the number of +nodes increase with that information it + + align:start position:0% +nodes increase with that information it + + + align:start position:0% +nodes increase with that information it +already becomes kind of plausible that + + align:start position:0% +already becomes kind of plausible that + + + align:start position:0% +already becomes kind of plausible that +you can sketch a general wave function \ No newline at end of file diff --git a/7GF78YQz62w.txt b/7GF78YQz62w.txt new file mode 100644 index 0000000000000000000000000000000000000000..53a70013563d7880091bea441c2e2b135015ac0a --- /dev/null +++ b/7GF78YQz62w.txt @@ -0,0 +1,891 @@ +align:start position:0% + +So Andrew, before the show, we asked you + + align:start position:0% +So Andrew, before the show, we asked you + + + align:start position:0% +So Andrew, before the show, we asked you +to respond to a question which we'll we + + align:start position:0% +to respond to a question which we'll we + + + align:start position:0% +to respond to a question which we'll we +will now reveal the answer to. So the + + align:start position:0% +will now reveal the answer to. So the + + + align:start position:0% +will now reveal the answer to. So the +question was, should I Sarah Hansen use + + align:start position:0% +question was, should I Sarah Hansen use + + + align:start position:0% +question was, should I Sarah Hansen use +chat GPT right now to plan my + + align:start position:0% +chat GPT right now to plan my + + + align:start position:0% +chat GPT right now to plan my +retirement? What's our answer? + + align:start position:0% +retirement? What's our answer? + + + align:start position:0% +retirement? What's our answer? +Not yet. Okay, please explain. Not yet. + + align:start position:0% +Not yet. Okay, please explain. Not yet. + + + align:start position:0% +Not yet. Okay, please explain. Not yet. +Because large language models are not + + align:start position:0% +Because large language models are not + + + align:start position:0% +Because large language models are not +yet ready to be able to do delegated + + align:start position:0% +yet ready to be able to do delegated + + + align:start position:0% +yet ready to be able to do delegated +financial decision-m for us. M turns out + + align:start position:0% +financial decision-m for us. M turns out + + + align:start position:0% +financial decision-m for us. M turns out +that saving for retirement is one set of + + align:start position:0% +that saving for retirement is one set of + + + align:start position:0% +that saving for retirement is one set of +activities but then spending while in + + align:start position:0% +activities but then spending while in + + + align:start position:0% +activities but then spending while in +retirement that's a whole different set + + align:start position:0% +retirement that's a whole different set + + + align:start position:0% +retirement that's a whole different set +of activities and many of us have become + + align:start position:0% +of activities and many of us have become + + + align:start position:0% +of activities and many of us have become +good at saving but you know we've been + + align:start position:0% +good at saving but you know we've been + + + align:start position:0% +good at saving but you know we've been +such good savers that we forget that at + + align:start position:0% +such good savers that we forget that at + + + align:start position:0% +such good savers that we forget that at +some point we need to spend and and we + + align:start position:0% +some point we need to spend and and we + + + align:start position:0% +some point we need to spend and and we +have to spend at the right rate for the + + align:start position:0% +have to spend at the right rate for the + + + align:start position:0% +have to spend at the right rate for the +right things at the right times. So what + + align:start position:0% +right things at the right times. So what + + + align:start position:0% +right things at the right times. So what +my colleagues and I are trying to + + align:start position:0% +my colleagues and I are trying to + + + align:start position:0% +my colleagues and I are trying to +understand now is not only what those + + align:start position:0% +understand now is not only what those + + + align:start position:0% +understand now is not only what those +optimal decisions are. I think we now + + align:start position:0% +optimal decisions are. I think we now + + + align:start position:0% +optimal decisions are. I think we now +have a lot of information about that. + + align:start position:0% +have a lot of information about that. + + + align:start position:0% +have a lot of information about that. +There's been a lot of research done on + + align:start position:0% +There's been a lot of research done on + + + align:start position:0% +There's been a lot of research done on +that. But the more challenging issue is + + align:start position:0% +that. But the more challenging issue is + + + align:start position:0% +that. But the more challenging issue is +how do we communicate that to people who + + align:start position:0% +how do we communicate that to people who + + + align:start position:0% +how do we communicate that to people who +don't have any finance background and + + align:start position:0% +don't have any finance background and + + + align:start position:0% +don't have any finance background and +and moreover can't afford to hire the + + align:start position:0% +and moreover can't afford to hire the + + + align:start position:0% +and moreover can't afford to hire the +financial adviserss that some of the + + align:start position:0% +financial adviserss that some of the + + + align:start position:0% +financial adviserss that some of the +higher net worth individuals have access + + align:start position:0% +higher net worth individuals have access + + + align:start position:0% +higher net worth individuals have access +to. So we're working on an AI solution + + align:start position:0% +to. So we're working on an AI solution + + + align:start position:0% +to. So we're working on an AI solution +uh an AI financial adviser that can + + align:start position:0% +uh an AI financial adviser that can + + + align:start position:0% +uh an AI financial adviser that can +satisfy the most important criterion of + + align:start position:0% +satisfy the most important criterion of + + + align:start position:0% +satisfy the most important criterion of +financial advice that regulators impose + + align:start position:0% +financial advice that regulators impose + + + align:start position:0% +financial advice that regulators impose +which is something called fiduciary + + align:start position:0% +which is something called fiduciary + + + align:start position:0% +which is something called fiduciary +duty. A fiduciary is somebody who is + + align:start position:0% +duty. A fiduciary is somebody who is + + + align:start position:0% +duty. A fiduciary is somebody who is +appointed to help you further your + + align:start position:0% +appointed to help you further your + + + align:start position:0% +appointed to help you further your +goals, will look out for your best + + align:start position:0% +goals, will look out for your best + + + align:start position:0% +goals, will look out for your best +interests uh above and beyond their own. + + align:start position:0% +interests uh above and beyond their own. + + + align:start position:0% +interests uh above and beyond their own. +And so very often people get a little + + align:start position:0% +And so very often people get a little + + + align:start position:0% +And so very often people get a little +bit concerned about you know financial + + align:start position:0% +bit concerned about you know financial + + + align:start position:0% +bit concerned about you know financial +planners and other people in the + + align:start position:0% +planners and other people in the + + + align:start position:0% +planners and other people in the +financial industry because they don't + + align:start position:0% +financial industry because they don't + + + align:start position:0% +financial industry because they don't +want to be taken advantage of. And you + + align:start position:0% +want to be taken advantage of. And you + + + align:start position:0% +want to be taken advantage of. And you +know there are many good financial + + align:start position:0% +know there are many good financial + + + align:start position:0% +know there are many good financial +planners out there but not everybody can + + align:start position:0% +planners out there but not everybody can + + + align:start position:0% +planners out there but not everybody can +afford one. So the question is can you + + align:start position:0% +afford one. So the question is can you + + + align:start position:0% +afford one. So the question is can you +for those people who can't afford + + align:start position:0% +for those people who can't afford + + + align:start position:0% +for those people who can't afford +financial planning and for the financial + + align:start position:0% +financial planning and for the financial + + + align:start position:0% +financial planning and for the financial +institutions that don't want to spend + + align:start position:0% +institutions that don't want to spend + + + align:start position:0% +institutions that don't want to spend +their resources of financial advice to + + align:start position:0% +their resources of financial advice to + + + align:start position:0% +their resources of financial advice to +those who aren't going to generate + + align:start position:0% +those who aren't going to generate + + + align:start position:0% +those who aren't going to generate +enough commissions for them for these + + align:start position:0% +enough commissions for them for these + + + align:start position:0% +enough commissions for them for these +people can we come up with uh financial + + align:start position:0% +people can we come up with uh financial + + + align:start position:0% +people can we come up with uh financial +advice from an AI platform that + + align:start position:0% +advice from an AI platform that + + + align:start position:0% +advice from an AI platform that +satisfies a definition of a fiduciary + + align:start position:0% +satisfies a definition of a fiduciary + + + align:start position:0% +satisfies a definition of a fiduciary +some some program that you can trust to + + align:start position:0% +some some program that you can trust to + + + align:start position:0% +some some program that you can trust to +look out for your best interest. We're + + align:start position:0% +look out for your best interest. We're + + + align:start position:0% +look out for your best interest. We're +not there yet. However, I believe that + + align:start position:0% +not there yet. However, I believe that + + + align:start position:0% +not there yet. However, I believe that +everybody should use large language + + align:start position:0% +everybody should use large language + + + align:start position:0% +everybody should use large language +models to help them think through + + align:start position:0% +models to help them think through + + + align:start position:0% +models to help them think through +retirement issues more seriously. For + + align:start position:0% +retirement issues more seriously. For + + + align:start position:0% +retirement issues more seriously. For +example, ask JBT, "What are the biggest + + align:start position:0% +example, ask JBT, "What are the biggest + + + align:start position:0% +example, ask JBT, "What are the biggest +issues that I need to focus on for my + + align:start position:0% +issues that I need to focus on for my + + + align:start position:0% +issues that I need to focus on for my +retirement? How much time do I have? + + align:start position:0% +retirement? How much time do I have? + + + align:start position:0% +retirement? How much time do I have? +What kind of ideas and products and + + align:start position:0% +What kind of ideas and products and + + + align:start position:0% +What kind of ideas and products and +services should I make use of? How do I + + align:start position:0% +services should I make use of? How do I + + + align:start position:0% +services should I make use of? How do I +get better financial information? How do + + align:start position:0% +get better financial information? How do + + + align:start position:0% +get better financial information? How do +I learn more about these problems?" All + + align:start position:0% +I learn more about these problems?" All + + + align:start position:0% +I learn more about these problems?" All +of those things I think ChatBT can do a + + align:start position:0% +of those things I think ChatBT can do a + + + align:start position:0% +of those things I think ChatBT can do a +pretty good job at, but I wouldn't let + + align:start position:0% +pretty good job at, but I wouldn't let + + + align:start position:0% +pretty good job at, but I wouldn't let +it make your decisions for you. Real + + align:start position:0% +it make your decisions for you. Real + + + align:start position:0% +it make your decisions for you. Real +question for you. I know a lot of times + + align:start position:0% +question for you. I know a lot of times + + + align:start position:0% +question for you. I know a lot of times +when I put in a prompt that's um within + + align:start position:0% +when I put in a prompt that's um within + + + align:start position:0% +when I put in a prompt that's um within +my domain of expertise, some of it will + + align:start position:0% +my domain of expertise, some of it will + + + align:start position:0% +my domain of expertise, some of it will +be good, but some of it's kind of + + align:start position:0% +be good, but some of it's kind of + + + align:start position:0% +be good, but some of it's kind of +garbage and not all that accurate. So, + + align:start position:0% +garbage and not all that accurate. So, + + + align:start position:0% +garbage and not all that accurate. So, +as a person who doesn't know finance, + + align:start position:0% +as a person who doesn't know finance, + + + align:start position:0% +as a person who doesn't know finance, +how do I know I can trust the answers + + align:start position:0% +how do I know I can trust the answers + + + align:start position:0% +how do I know I can trust the answers +that are coming back even about those + + align:start position:0% +that are coming back even about those + + + align:start position:0% +that are coming back even about those +general type of questions? Well, so + + align:start position:0% +general type of questions? Well, so + + + align:start position:0% +general type of questions? Well, so +that's really why you need to have + + align:start position:0% +that's really why you need to have + + + align:start position:0% +that's really why you need to have +additional time and effort employed in + + align:start position:0% +additional time and effort employed in + + + align:start position:0% +additional time and effort employed in +thinking through these issues, not just + + align:start position:0% +thinking through these issues, not just + + + align:start position:0% +thinking through these issues, not just +by yourself, but with friends and + + align:start position:0% +by yourself, but with friends and + + + align:start position:0% +by yourself, but with friends and +family. Yeah. So we need human support + + align:start position:0% +family. Yeah. So we need human support + + + align:start position:0% +family. Yeah. So we need human support +for thinking about how large language + + align:start position:0% +for thinking about how large language + + + align:start position:0% +for thinking about how large language +models can work either well or in some + + align:start position:0% +models can work either well or in some + + + align:start position:0% +models can work either well or in some +cases not so well. And in any case, if + + align:start position:0% +cases not so well. And in any case, if + + + align:start position:0% +cases not so well. And in any case, if +you are planning for your retirement, at + + align:start position:0% +you are planning for your retirement, at + + + align:start position:0% +you are planning for your retirement, at +some point or another, you're going to + + align:start position:0% +some point or another, you're going to + + + align:start position:0% +some point or another, you're going to +have to engage with people from the + + align:start position:0% +have to engage with people from the + + + align:start position:0% +have to engage with people from the +financial institutions. Yeah. They will + + align:start position:0% +financial institutions. Yeah. They will + + + align:start position:0% +financial institutions. Yeah. They will +be able to help deal with some of the + + align:start position:0% +be able to help deal with some of the + + + align:start position:0% +be able to help deal with some of the +so-called hallucination problems with + + align:start position:0% +so-called hallucination problems with + + + align:start position:0% +so-called hallucination problems with +these large language models. But the + + align:start position:0% +these large language models. But the + + + align:start position:0% +these large language models. But the +answer is like anything else that we do. + + align:start position:0% +answer is like anything else that we do. + + + align:start position:0% +answer is like anything else that we do. +You know, how do you know that your + + align:start position:0% +You know, how do you know that your + + + align:start position:0% +You know, how do you know that your +doctor is always giving you the best + + align:start position:0% +doctor is always giving you the best + + + align:start position:0% +doctor is always giving you the best +information? Doctors are very highly + + align:start position:0% +information? Doctors are very highly + + + align:start position:0% +information? Doctors are very highly +trained, but they do make mistakes. So + + align:start position:0% +trained, but they do make mistakes. So + + + align:start position:0% +trained, but they do make mistakes. So +get a second opinion, get a third + + align:start position:0% +get a second opinion, get a third + + + align:start position:0% +get a second opinion, get a third +opinion, talk to your family members. + + align:start position:0% +opinion, talk to your family members. + + + align:start position:0% +opinion, talk to your family members. +Ultimately, you're going to be + + align:start position:0% +Ultimately, you're going to be + + + align:start position:0% +Ultimately, you're going to be +responsible for your own decisions. But + + align:start position:0% +responsible for your own decisions. But + + + align:start position:0% +responsible for your own decisions. But +the more informed you can be and the + + align:start position:0% +the more informed you can be and the + + + align:start position:0% +the more informed you can be and the +more you can check the uh accuracy of + + align:start position:0% +more you can check the uh accuracy of + + + align:start position:0% +more you can check the uh accuracy of +the information and that information + + align:start position:0% +the information and that information + + + align:start position:0% +the information and that information +come from humans or from chat bots, I + + align:start position:0% +come from humans or from chat bots, I + + + align:start position:0% +come from humans or from chat bots, I +think those are the ways that we've + + align:start position:0% +think those are the ways that we've + + + align:start position:0% +think those are the ways that we've +developed for making sure that we make + + align:start position:0% +developed for making sure that we make + + + align:start position:0% +developed for making sure that we make +the best decisions possible. \ No newline at end of file diff --git a/7aNYj3zyVkc.txt b/7aNYj3zyVkc.txt new file mode 100644 index 0000000000000000000000000000000000000000..c3894b4ebcb9a76f22fcd6450a1fdca5968b9842 --- /dev/null +++ b/7aNYj3zyVkc.txt @@ -0,0 +1,7571 @@ +align:start position:0% + +um I've emphasized in the first lecture + + align:start position:0% +um I've emphasized in the first lecture + + + align:start position:0% +um I've emphasized in the first lecture +you know that this is there's a lot of + + align:start position:0% +you know that this is there's a lot of + + + align:start position:0% +you know that this is there's a lot of +stuff that happens uh just in your + + align:start position:0% +stuff that happens uh just in your + + + align:start position:0% +stuff that happens uh just in your +ordinary life I saw two examples of this + + align:start position:0% +ordinary life I saw two examples of this + + + align:start position:0% +ordinary life I saw two examples of this +yesterday yesterday's Boston Globe just + + align:start position:0% +yesterday yesterday's Boston Globe just + + + align:start position:0% +yesterday yesterday's Boston Globe just +on the front page uh there was a + + align:start position:0% +on the front page uh there was a + + + align:start position:0% +on the front page uh there was a +discovery uh about heart cell Discovery + + align:start position:0% +discovery uh about heart cell Discovery + + + align:start position:0% +discovery uh about heart cell Discovery +raises treatment hopes scientists + + align:start position:0% +raises treatment hopes scientists + + + align:start position:0% +raises treatment hopes scientists +announced yesterday discovery of cells + + align:start position:0% +announced yesterday discovery of cells + + + align:start position:0% +announced yesterday discovery of cells +in the heart that can create new muscle + + align:start position:0% +in the heart that can create new muscle + + + align:start position:0% +in the heart that can create new muscle +cells raising hopes that doctors may + + align:start position:0% +cells raising hopes that doctors may + + + align:start position:0% +cells raising hopes that doctors may +find dramatic new ways to treat heart + + align:start position:0% +find dramatic new ways to treat heart + + + align:start position:0% +find dramatic new ways to treat heart +disease uh they're show the team showed + + align:start position:0% +disease uh they're show the team showed + + + align:start position:0% +disease uh they're show the team showed +that the cells which are similar to sem + + align:start position:0% +that the cells which are similar to sem + + + align:start position:0% +that the cells which are similar to sem +cells can be expanded from just a few + + align:start position:0% +cells can be expanded from just a few + + + align:start position:0% +cells can be expanded from just a few +hundred in a laboratory dish up to uh to + + align:start position:0% +hundred in a laboratory dish up to uh to + + + align:start position:0% +hundred in a laboratory dish up to uh to +more than a million and these can be + + align:start position:0% +more than a million and these can be + + + align:start position:0% +more than a million and these can be +guided into becoming the pulsing mus + + align:start position:0% +guided into becoming the pulsing mus + + + align:start position:0% +guided into becoming the pulsing mus +muscles that power the heart so we were + + align:start position:0% +muscles that power the heart so we were + + + align:start position:0% +muscles that power the heart so we were +talking about those yeast dividing and + + align:start position:0% +talking about those yeast dividing and + + + align:start position:0% +talking about those yeast dividing and +saying how one cell becomes two this is + + align:start position:0% +saying how one cell becomes two this is + + + align:start position:0% +saying how one cell becomes two this is +a general principle throughout life that + + align:start position:0% +a general principle throughout life that + + + align:start position:0% +a general principle throughout life that +cells come from other cells and they + + align:start position:0% +cells come from other cells and they + + + align:start position:0% +cells come from other cells and they +divide and you can will see the + + align:start position:0% +divide and you can will see the + + + align:start position:0% +divide and you can will see the +relationship to that with DNA + + align:start position:0% +relationship to that with DNA + + + align:start position:0% +relationship to that with DNA +replication as we go along case of a + + align:start position:0% +replication as we go along case of a + + + align:start position:0% +replication as we go along case of a +yeast as I said they're just always the + + align:start position:0% +yeast as I said they're just always the + + + align:start position:0% +yeast as I said they're just always the +same you're probably are always the same + + align:start position:0% +same you're probably are always the same + + + align:start position:0% +same you're probably are always the same +but in something like our own cells we + + align:start position:0% +but in something like our own cells we + + + align:start position:0% +but in something like our own cells we +start out as a single fertilized cell + + align:start position:0% +start out as a single fertilized cell + + + align:start position:0% +start out as a single fertilized cell +but somewhere along the way the cells + + align:start position:0% +but somewhere along the way the cells + + + align:start position:0% +but somewhere along the way the cells +have to become specialized so the very + + align:start position:0% +have to become specialized so the very + + + align:start position:0% +have to become specialized so the very +early ones are the embryonic stem cells + + align:start position:0% +early ones are the embryonic stem cells + + + align:start position:0% +early ones are the embryonic stem cells +they have the potential to become any + + align:start position:0% +they have the potential to become any + + + align:start position:0% +they have the potential to become any +cell in the body but at some point uh + + align:start position:0% +cell in the body but at some point uh + + + align:start position:0% +cell in the body but at some point uh +there's at one of these cell divisions + + align:start position:0% +there's at one of these cell divisions + + + align:start position:0% +there's at one of these cell divisions +the cells are going to have to start to + + align:start position:0% +the cells are going to have to start to + + + align:start position:0% +the cells are going to have to start to +become more specialized and for example + + align:start position:0% +become more specialized and for example + + + align:start position:0% +become more specialized and for example +this one might be a lineage that would + + align:start position:0% +this one might be a lineage that would + + + align:start position:0% +this one might be a lineage that would +lead to the heart muscle or to becom a + + align:start position:0% +lead to the heart muscle or to becom a + + + align:start position:0% +lead to the heart muscle or to becom a +nerve or something and at that point it + + align:start position:0% +nerve or something and at that point it + + + align:start position:0% +nerve or something and at that point it +loses its ability to become any cell in + + align:start position:0% +loses its ability to become any cell in + + + align:start position:0% +loses its ability to become any cell in +the body and in many cases by the time + + align:start position:0% +the body and in many cases by the time + + + align:start position:0% +the body and in many cases by the time +you get out ultimately to the + + align:start position:0% +you get out ultimately to the + + + align:start position:0% +you get out ultimately to the +final um cell that's making up the + + align:start position:0% +final um cell that's making up the + + + align:start position:0% +final um cell that's making up the +muscle or the nerve or something it has + + align:start position:0% +muscle or the nerve or something it has + + + align:start position:0% +muscle or the nerve or something it has +no capacity to regenerate so that's why + + align:start position:0% +no capacity to regenerate so that's why + + + align:start position:0% +no capacity to regenerate so that's why +for example spinal cord injuries are so + + align:start position:0% +for example spinal cord injuries are so + + + align:start position:0% +for example spinal cord injuries are so +damaging because nerves at this point + + align:start position:0% +damaging because nerves at this point + + + align:start position:0% +damaging because nerves at this point +can't be regenerated or heart disease + + align:start position:0% +can't be regenerated or heart disease + + + align:start position:0% +can't be regenerated or heart disease +you get a damaged heart or stuck this is + + align:start position:0% +you get a damaged heart or stuck this is + + + align:start position:0% +you get a damaged heart or stuck this is +why this result is exciting because + + align:start position:0% +why this result is exciting because + + + align:start position:0% +why this result is exciting because +there seem to be at least a few cells in + + align:start position:0% +there seem to be at least a few cells in + + + align:start position:0% +there seem to be at least a few cells in +the heart in the heart that have the + + align:start position:0% +the heart in the heart that have the + + + align:start position:0% +the heart in the heart that have the +capacity to regenerate more more heart + + align:start position:0% +capacity to regenerate more more heart + + + align:start position:0% +capacity to regenerate more more heart +heart muscle now this is early on it + + align:start position:0% +heart muscle now this is early on it + + + align:start position:0% +heart muscle now this is early on it +hasn't been rigorously shown to be a + + align:start position:0% +hasn't been rigorously shown to be a + + + align:start position:0% +hasn't been rigorously shown to be a +stem cell but there's an example from + + align:start position:0% +stem cell but there's an example from + + + align:start position:0% +stem cell but there's an example from +yesterday's front of yesterday's paper + + align:start position:0% +yesterday's front of yesterday's paper + + + align:start position:0% +yesterday's front of yesterday's paper +about something we were virtually + + align:start position:0% +about something we were virtually + + + align:start position:0% +about something we were virtually +alluding to in class there was oops + + align:start position:0% +alluding to in class there was oops + + + align:start position:0% +alluding to in class there was oops +there was also that an article about + + align:start position:0% +there was also that an article about + + + align:start position:0% +there was also that an article about +AIDS testing again you know that we'll + + align:start position:0% +AIDS testing again you know that we'll + + + align:start position:0% +AIDS testing again you know that we'll +talk more about the H hiv1 virus and + + align:start position:0% +talk more about the H hiv1 virus and + + + align:start position:0% +talk more about the H hiv1 virus and +then today on the on the front page AG + + align:start position:0% +then today on the on the front page AG + + + align:start position:0% +then today on the on the front page AG +of the Boston Globe yet again as Romney + + align:start position:0% +of the Boston Globe yet again as Romney + + + align:start position:0% +of the Boston Globe yet again as Romney +draws fire on stem cells and um you you + + align:start position:0% +draws fire on stem cells and um you you + + + align:start position:0% +draws fire on stem cells and um you you +you can look at this uh but you know + + align:start position:0% +you can look at this uh but you know + + + align:start position:0% +you can look at this uh but you know +he's sort of trying to straddle I guess + + align:start position:0% +he's sort of trying to straddle I guess + + + align:start position:0% +he's sort of trying to straddle I guess +between uh being supportive of research + + align:start position:0% +between uh being supportive of research + + + align:start position:0% +between uh being supportive of research +in the one hand and the concerns of uh + + align:start position:0% +in the one hand and the concerns of uh + + + align:start position:0% +in the one hand and the concerns of uh +the conservatives and religious right on + + align:start position:0% +the conservatives and religious right on + + + align:start position:0% +the conservatives and religious right on +the other hand and he's drawing fire + + align:start position:0% +the other hand and he's drawing fire + + + align:start position:0% +the other hand and he's drawing fire +from from both sides but it's an issue + + align:start position:0% +from from both sides but it's an issue + + + align:start position:0% +from from both sides but it's an issue +that is in our society today you're + + align:start position:0% +that is in our society today you're + + + align:start position:0% +that is in our society today you're +going to be expected to make decisions + + align:start position:0% +going to be expected to make decisions + + + align:start position:0% +going to be expected to make decisions +on it to know about it and understand + + align:start position:0% +on it to know about it and understand + + + align:start position:0% +on it to know about it and understand +just trying to drive home that this what + + align:start position:0% +just trying to drive home that this what + + + align:start position:0% +just trying to drive home that this what +we're talking about isn't taking place + + align:start position:0% +we're talking about isn't taking place + + + align:start position:0% +we're talking about isn't taking place +in a + + align:start position:0% +in a + + + align:start position:0% +in a +vacuum um nobody emailed + + align:start position:0% +vacuum um nobody emailed + + + align:start position:0% +vacuum um nobody emailed +me um an idea as to what happened here I + + align:start position:0% +me um an idea as to what happened here I + + + align:start position:0% +me um an idea as to what happened here I +showed you this little movie this sing + + align:start position:0% +showed you this little movie this sing + + + align:start position:0% +showed you this little movie this sing +this uh is water that's cooled below the + + align:start position:0% +this uh is water that's cooled below the + + + align:start position:0% +this uh is water that's cooled below the +freezing point but it hasn't uh formed + + align:start position:0% +freezing point but it hasn't uh formed + + + align:start position:0% +freezing point but it hasn't uh formed +ice crystals but if we put a little bit + + align:start position:0% +ice crystals but if we put a little bit + + + align:start position:0% +ice crystals but if we put a little bit +of this + + align:start position:0% +of this + + + align:start position:0% +of this +pomonis uh singi in it then it uh + + align:start position:0% +pomonis uh singi in it then it uh + + + align:start position:0% +pomonis uh singi in it then it uh +somehow that super cooled water turned + + align:start position:0% +somehow that super cooled water turned + + + align:start position:0% +somehow that super cooled water turned +into ice and I told you it was a protein + + align:start position:0% +into ice and I told you it was a protein + + + align:start position:0% +into ice and I told you it was a protein +on the surface nobody had any ideas so + + align:start position:0% +on the surface nobody had any ideas so + + + align:start position:0% +on the surface nobody had any ideas so +why don't you turn to whoever's close to + + align:start position:0% +why don't you turn to whoever's close to + + + align:start position:0% +why don't you turn to whoever's close to +you and you can talk about it for 30 + + align:start position:0% +you and you can talk about it for 30 + + + align:start position:0% +you and you can talk about it for 30 +seconds see if anybody can come up with + + align:start position:0% +seconds see if anybody can come up with + + + align:start position:0% +seconds see if anybody can come up with +an idea as to why right I won't look you + + align:start position:0% +an idea as to why right I won't look you + + + align:start position:0% +an idea as to why right I won't look you +know just go ahead talk to somebody see + + align:start position:0% +know just go ahead talk to somebody see + + + align:start position:0% +know just go ahead talk to somebody see +what come up with an + + align:start position:0% + + + + align:start position:0% + +idea + + align:start position:0% + + + + align:start position:0% + +for + + align:start position:0% + + + + align:start position:0% + +okay well let's see we manage to get any + + align:start position:0% +okay well let's see we manage to get any + + + align:start position:0% +okay well let's see we manage to get any +any ideas anybody got the courage to try + + align:start position:0% +any ideas anybody got the courage to try + + + align:start position:0% +any ideas anybody got the courage to try +and uh guess what that protein might be + + align:start position:0% +and uh guess what that protein might be + + + align:start position:0% +and uh guess what that protein might be +doing it's a molecule okay it's a + + align:start position:0% +doing it's a molecule okay it's a + + + align:start position:0% +doing it's a molecule okay it's a +nonpolar molecule it's disturbing the + + align:start position:0% +nonpolar molecule it's disturbing the + + + align:start position:0% +nonpolar molecule it's disturbing the +bonds it's a non-polar molecule it's not + + align:start position:0% +bonds it's a non-polar molecule it's not + + + align:start position:0% +bonds it's a non-polar molecule it's not +disturbing the + + align:start position:0% +disturbing the + + + align:start position:0% +disturbing the +bonds um it's interesting idea do you + + align:start position:0% +bonds um it's interesting idea do you + + + align:start position:0% +bonds um it's interesting idea do you +have an idea then able to extend that as + + align:start position:0% +have an idea then able to extend that as + + + align:start position:0% +have an idea then able to extend that as +to why then ice would start to + + align:start position:0% +to why then ice would start to + + + align:start position:0% +to why then ice would start to +form I mean certainly true that + + align:start position:0% +form I mean certainly true that + + + align:start position:0% +form I mean certainly true that +non-polar bonds sort of interfere with + + align:start position:0% +non-polar bonds sort of interfere with + + + align:start position:0% +non-polar bonds sort of interfere with +the water that's something we' we've + + align:start position:0% +the water that's something we' we've + + + align:start position:0% +the water that's something we' we've +talked about um let's see any other + + align:start position:0% +talked about um let's see any other + + + align:start position:0% +talked about um let's see any other +ideas + + align:start position:0% + + + + align:start position:0% + +yeah that's that's a version of the same + + align:start position:0% +yeah that's that's a version of the same + + + align:start position:0% +yeah that's that's a version of the same +idea I think hydrophobic you think he + + align:start position:0% +idea I think hydrophobic you think he + + + align:start position:0% +idea I think hydrophobic you think he +wants to repel the water and push it + + align:start position:0% +wants to repel the water and push it + + + align:start position:0% +wants to repel the water and push it +together that's that's an interesting + + align:start position:0% +together that's that's an interesting + + + align:start position:0% +together that's that's an interesting +you're sort of getting closer on these + + align:start position:0% +you're sort of getting closer on these + + + align:start position:0% +you're sort of getting closer on these +yeah you + + align:start position:0% + + + + align:start position:0% + +said + + align:start position:0% + + + + align:start position:0% + +yeah there there it is if you were to + + align:start position:0% +yeah there there it is if you were to + + + align:start position:0% +yeah there there it is if you were to +design a protein that basically could + + align:start position:0% +design a protein that basically could + + + align:start position:0% +design a protein that basically could +bind water + + align:start position:0% +bind water + + + align:start position:0% +bind water +molecules in a lattice that mimicked + + align:start position:0% +molecules in a lattice that mimicked + + + align:start position:0% +molecules in a lattice that mimicked +what you found in ice then the water + + align:start position:0% +what you found in ice then the water + + + align:start position:0% +what you found in ice then the water +molecules coming up and binding to these + + align:start position:0% +molecules coming up and binding to these + + + align:start position:0% +molecules coming up and binding to these +little pockets in the protein would + + align:start position:0% +little pockets in the protein would + + + align:start position:0% +little pockets in the protein would +present then a little field of stable + + align:start position:0% +present then a little field of stable + + + align:start position:0% +present then a little field of stable +water molecules that looked to the next + + align:start position:0% +water molecules that looked to the next + + + align:start position:0% +water molecules that looked to the next +water molecule like it was an ice part + + align:start position:0% +water molecule like it was an ice part + + + align:start position:0% +water molecule like it was an ice part +of an Ice Crystal and that's that's + + align:start position:0% +of an Ice Crystal and that's that's + + + align:start position:0% +of an Ice Crystal and that's that's +indeed how that that bacterium does that + + align:start position:0% +indeed how that that bacterium does that + + + align:start position:0% +indeed how that that bacterium does that +trick it's called the ice nucleation + + align:start position:0% +trick it's called the ice nucleation + + + align:start position:0% +trick it's called the ice nucleation +protein and they do things like take + + align:start position:0% +protein and they do things like take + + + align:start position:0% +protein and they do things like take +this bacterium and they put it into + + align:start position:0% +this bacterium and they put it into + + + align:start position:0% +this bacterium and they put it into +things like when you're doing snow snow + + align:start position:0% +things like when you're doing snow snow + + + align:start position:0% +things like when you're doing snow snow +making um they can you put this in and + + align:start position:0% +making um they can you put this in and + + + align:start position:0% +making um they can you put this in and +then you spray the the cool the super + + align:start position:0% +then you spray the the cool the super + + + align:start position:0% +then you spray the the cool the super +cooled water and this makes it go into + + align:start position:0% +cooled water and this makes it go into + + + align:start position:0% +cooled water and this makes it go into +ice crystals and then it helps the the + + align:start position:0% +ice crystals and then it helps the the + + + align:start position:0% +ice crystals and then it helps the the +get nice snow for um + + align:start position:0% +get nice snow for um + + + align:start position:0% +get nice snow for um +for ski resorts and things that's that's + + align:start position:0% +for ski resorts and things that's that's + + + align:start position:0% +for ski resorts and things that's that's +at least one of the areas where it's + + align:start position:0% +at least one of the areas where it's + + + align:start position:0% +at least one of the areas where it's +where it's used okay so + + align:start position:0% + + + + align:start position:0% + +um so when I showed I'm just going to + + align:start position:0% +um so when I showed I'm just going to + + + align:start position:0% +um so when I showed I'm just going to +show you this movie again these are just + + align:start position:0% +show you this movie again these are just + + + align:start position:0% +show you this movie again these are just +baker's yeast sacr sis kind of single + + align:start position:0% +baker's yeast sacr sis kind of single + + + align:start position:0% +baker's yeast sacr sis kind of single +celled yeast that's used in in h baking + + align:start position:0% +celled yeast that's used in in h baking + + + align:start position:0% +celled yeast that's used in in h baking +bread or making beer and uh here we're + + align:start position:0% +bread or making beer and uh here we're + + + align:start position:0% +bread or making beer and uh here we're +seeing cells divide they and then this + + align:start position:0% +seeing cells divide they and then this + + + align:start position:0% +seeing cells divide they and then this +this particular kind of yeast uh has a + + align:start position:0% +this particular kind of yeast uh has a + + + align:start position:0% +this particular kind of yeast uh has a +way of doing it kind of buds the + + align:start position:0% +way of doing it kind of buds the + + + align:start position:0% +way of doing it kind of buds the +daughter off from the side some some + + align:start position:0% +daughter off from the side some some + + + align:start position:0% +daughter off from the side some some +double and then split down the middle + + align:start position:0% +double and then split down the middle + + + align:start position:0% +double and then split down the middle +but you can see what's going on there's + + align:start position:0% +but you can see what's going on there's + + + align:start position:0% +but you can see what's going on there's +a lot of cell growth going on and the + + align:start position:0% +a lot of cell growth going on and the + + + align:start position:0% +a lot of cell growth going on and the +issue that I I that we're going to + + align:start position:0% +issue that I I that we're going to + + + align:start position:0% +issue that I I that we're going to +address now is where does the energy + + align:start position:0% +address now is where does the energy + + + align:start position:0% +address now is where does the energy +come that's needed to do that you know + + align:start position:0% +come that's needed to do that you know + + + align:start position:0% +come that's needed to do that you know +from your own experience that to build + + align:start position:0% +from your own experience that to build + + + align:start position:0% +from your own experience that to build +things to make things takes takes energy + + align:start position:0% +things to make things takes takes energy + + + align:start position:0% +things to make things takes takes energy +you can't build put up a bridge you + + align:start position:0% +you can't build put up a bridge you + + + align:start position:0% +you can't build put up a bridge you +can't put up a building you can't design + + align:start position:0% +can't put up a building you can't design + + + align:start position:0% +can't put up a building you can't design +build a computer chip without some + + align:start position:0% +build a computer chip without some + + + align:start position:0% +build a computer chip without some +somehow putting energy in you're you're + + align:start position:0% +somehow putting energy in you're you're + + + align:start position:0% +somehow putting energy in you're you're +taking a bunch of matter in the universe + + align:start position:0% +taking a bunch of matter in the universe + + + align:start position:0% +taking a bunch of matter in the universe +and ordering it in a very uh specific + + align:start position:0% +and ordering it in a very uh specific + + + align:start position:0% +and ordering it in a very uh specific +way uh making new contacts didn't be + + align:start position:0% +way uh making new contacts didn't be + + + align:start position:0% +way uh making new contacts didn't be +there it's an energy requiring process + + align:start position:0% +there it's an energy requiring process + + + align:start position:0% +there it's an energy requiring process +and I'm going to talk today about where + + align:start position:0% +and I'm going to talk today about where + + + align:start position:0% +and I'm going to talk today about where +that energy comes from and and I want to + + align:start position:0% +that energy comes from and and I want to + + + align:start position:0% +that energy comes from and and I want to +tell you a little bit just very brief + + align:start position:0% +tell you a little bit just very brief + + + align:start position:0% +tell you a little bit just very brief +historical thing along the way because a + + align:start position:0% +historical thing along the way because a + + + align:start position:0% +historical thing along the way because a +point I've emphasized here is is biology + + align:start position:0% +point I've emphasized here is is biology + + + align:start position:0% +point I've emphasized here is is biology +is an experimental science and many of + + align:start position:0% +is an experimental science and many of + + + align:start position:0% +is an experimental science and many of +the greatest discoveries weren't because + + align:start position:0% +the greatest discoveries weren't because + + + align:start position:0% +the greatest discoveries weren't because +somebody had the idea and then and went + + align:start position:0% +somebody had the idea and then and went + + + align:start position:0% +somebody had the idea and then and went +out to prove it very often we didn't + + align:start position:0% +out to prove it very often we didn't + + + align:start position:0% +out to prove it very often we didn't +even understand how it worked and and + + align:start position:0% +even understand how it worked and and + + + align:start position:0% +even understand how it worked and and +somebody was investigating a phenomenon + + align:start position:0% +somebody was investigating a phenomenon + + + align:start position:0% +somebody was investigating a phenomenon +found some peculiar things and then + + align:start position:0% +found some peculiar things and then + + + align:start position:0% +found some peculiar things and then +began to get insights and the insights + + align:start position:0% +began to get insights and the insights + + + align:start position:0% +began to get insights and the insights +were what then + + align:start position:0% +were what then + + + align:start position:0% +were what then +um uh led to a fundamental uh increase + + align:start position:0% +um uh led to a fundamental uh increase + + + align:start position:0% +um uh led to a fundamental uh increase +in her understanding and this little bit + + align:start position:0% +in her understanding and this little bit + + + align:start position:0% +in her understanding and this little bit +of History involves some names that + + align:start position:0% +of History involves some names that + + + align:start position:0% +of History involves some names that +you've see on uh the MIT buildings + + align:start position:0% +you've see on uh the MIT buildings + + + align:start position:0% +you've see on uh the MIT buildings +around here one is laazer who is a + + align:start position:0% +around here one is laazer who is a + + + align:start position:0% +around here one is laazer who is a +French um + + align:start position:0% +French um + + + align:start position:0% +French um +a French scientist and he was + + align:start position:0% + + + + align:start position:0% + +studying what happened when + + align:start position:0% + + + + align:start position:0% + +grapes were converted into + + align:start position:0% +grapes were converted into + + + align:start position:0% +grapes were converted into +wine nice uh good topic for a French uh + + align:start position:0% +wine nice uh good topic for a French uh + + + align:start position:0% +wine nice uh good topic for a French uh +scientist to be studying so in essence + + align:start position:0% +scientist to be studying so in essence + + + align:start position:0% +scientist to be studying so in essence +what he was + + align:start position:0% +what he was + + + align:start position:0% +what he was +studying was + + align:start position:0% +studying was + + + align:start position:0% +studying was +glucose being converted to two two + + align:start position:0% +glucose being converted to two two + + + align:start position:0% +glucose being converted to two two +molecules + + align:start position:0% + + + + align:start position:0% + +uh excuse me + + align:start position:0% + + + + align:start position:0% + +of + + align:start position:0% + + + + align:start position:0% + +ethanol and two molecules of uh carbon + + align:start position:0% +ethanol and two molecules of uh carbon + + + align:start position:0% +ethanol and two molecules of uh carbon +dioxide this + + align:start position:0% +dioxide this + + + align:start position:0% +dioxide this +transformation there's C6 + + align:start position:0% +transformation there's C6 + + + align:start position:0% +transformation there's C6 +h12 06 remember + + align:start position:0% +h12 06 remember + + + align:start position:0% +h12 06 remember +carbohydrates have the have that uh + + align:start position:0% +carbohydrates have the have that uh + + + align:start position:0% +carbohydrates have the have that uh +that um composition um and so he was he + + align:start position:0% +that um composition um and so he was he + + + align:start position:0% +that um composition um and so he was he +was studying that he managed to figure + + align:start position:0% +was studying that he managed to figure + + + align:start position:0% +was studying that he managed to figure +out that's what happened to the sugar + + align:start position:0% +out that's what happened to the sugar + + + align:start position:0% +out that's what happened to the sugar +when you were making wine and at that + + align:start position:0% +when you were making wine and at that + + + align:start position:0% +when you were making wine and at that +point he got beheaded that terminated + + align:start position:0% +point he got beheaded that terminated + + + align:start position:0% +point he got beheaded that terminated +that part of uh his investigation but + + align:start position:0% +that part of uh his investigation but + + + align:start position:0% +that part of uh his investigation but +this was this problem was then picked up + + align:start position:0% +this was this problem was then picked up + + + align:start position:0% +this was this problem was then picked up +by uh L pester who uh again his uh his + + align:start position:0% +by uh L pester who uh again his uh his + + + align:start position:0% +by uh L pester who uh again his uh his +name is on one of the MIT buildings um + + align:start position:0% +name is on one of the MIT buildings um + + + align:start position:0% +name is on one of the MIT buildings um +he worked in France as well there's a + + align:start position:0% +he worked in France as well there's a + + + align:start position:0% +he worked in France as well there's a +pastor Institute in Paris there's a nice + + align:start position:0% +pastor Institute in Paris there's a nice + + + align:start position:0% +pastor Institute in Paris there's a nice +museum in Le in northern France that has + + align:start position:0% +museum in Le in northern France that has + + + align:start position:0% +museum in Le in northern France that has +a lot of this but he grew up in in ARB + + align:start position:0% +a lot of this but he grew up in in ARB + + + align:start position:0% +a lot of this but he grew up in in ARB +which is a town in sort of Eastern + + align:start position:0% +which is a town in sort of Eastern + + + align:start position:0% +which is a town in sort of Eastern +France that as you can see from the the + + align:start position:0% +France that as you can see from the the + + + align:start position:0% +France that as you can see from the the +from the little picture of the village + + align:start position:0% +from the little picture of the village + + + align:start position:0% +from the little picture of the village +wine making was a major industry so he + + align:start position:0% +wine making was a major industry so he + + + align:start position:0% +wine making was a major industry so he +was was interested in that probably from + + align:start position:0% +was was interested in that probably from + + + align:start position:0% +was was interested in that probably from +when he was a small small kid although + + align:start position:0% +when he was a small small kid although + + + align:start position:0% +when he was a small small kid although +probably not dressed like that but + + align:start position:0% +probably not dressed like that but + + + align:start position:0% +probably not dressed like that but +anyway so he one of the issues that he + + align:start position:0% +anyway so he one of the issues that he + + + align:start position:0% +anyway so he one of the issues that he +he took on which was a real problem for + + align:start position:0% +he took on which was a real problem for + + + align:start position:0% +he took on which was a real problem for +the wine growers in in his little town + + align:start position:0% +the wine growers in in his little town + + + align:start position:0% +the wine growers in in his little town +and in France in general was sometimes + + align:start position:0% +and in France in general was sometimes + + + align:start position:0% +and in France in general was sometimes +wines would go bad they'd come out sour + + align:start position:0% +wines would go bad they'd come out sour + + + align:start position:0% +wines would go bad they'd come out sour +and they they couldn't be drunk and then + + align:start position:0% +and they they couldn't be drunk and then + + + align:start position:0% +and they they couldn't be drunk and then +you'd lose all the all the profit that + + align:start position:0% +you'd lose all the all the profit that + + + align:start position:0% +you'd lose all the all the profit that +would have come from from that wine so + + align:start position:0% +would have come from from that wine so + + + align:start position:0% +would have come from from that wine so +there's a lot of interest in trying to + + align:start position:0% +there's a lot of interest in trying to + + + align:start position:0% +there's a lot of interest in trying to +figure out how to prevent uh wines from + + align:start position:0% +figure out how to prevent uh wines from + + + align:start position:0% +figure out how to prevent uh wines from +going bad and so Louis pester started to + + align:start position:0% +going bad and so Louis pester started to + + + align:start position:0% +going bad and so Louis pester started to +to study this and he discovered + + align:start position:0% +to study this and he discovered + + + align:start position:0% +to study this and he discovered +that uh that the there was this + + align:start position:0% +that uh that the there was this + + + align:start position:0% +that uh that the there was this +conversion + + align:start position:0% + + + + align:start position:0% + +that had been figured out now of + + align:start position:0% + + + + align:start position:0% + +two + + align:start position:0% +two + + + align:start position:0% +two +ethanol to carbon dioxide so this was a + + align:start position:0% + + + + align:start position:0% + +conversion and we now refer to it + + align:start position:0% +conversion and we now refer to it + + + align:start position:0% +conversion and we now refer to it +generally as a + + align:start position:0% + + + + align:start position:0% + +fermentation but what he discovered was + + align:start position:0% +fermentation but what he discovered was + + + align:start position:0% +fermentation but what he discovered was +this conversion + + align:start position:0% + + + + align:start position:0% + +occurred + + align:start position:0% + + + + align:start position:0% + +if yeast were + + align:start position:0% + + + + align:start position:0% + +present that the rate of this conversion + + align:start position:0% +present that the rate of this conversion + + + align:start position:0% +present that the rate of this conversion +varied as the number of yeast so it went + + align:start position:0% +varied as the number of yeast so it went + + + align:start position:0% +varied as the number of yeast so it went +faster if there were more yeast and the + + align:start position:0% +faster if there were more yeast and the + + + align:start position:0% +faster if there were more yeast and the +yeast stopped + + align:start position:0% + + + + align:start position:0% + +growing + + align:start position:0% + + + + align:start position:0% + +when the sugar ran + + align:start position:0% + + + + align:start position:0% + +out so what he discovered here was a + + align:start position:0% +out so what he discovered here was a + + + align:start position:0% +out so what he discovered here was a +correlation he hadn't proven anything he + + align:start position:0% +correlation he hadn't proven anything he + + + align:start position:0% +correlation he hadn't proven anything he +just saw that if you watch sugar go to + + align:start position:0% +just saw that if you watch sugar go to + + + align:start position:0% +just saw that if you watch sugar go to +ethanol there were yeast around if you + + align:start position:0% +ethanol there were yeast around if you + + + align:start position:0% +ethanol there were yeast around if you +had more yeast it went faster and when + + align:start position:0% +had more yeast it went faster and when + + + align:start position:0% +had more yeast it went faster and when +you ran out of sugar the yeast stopped + + align:start position:0% +you ran out of sugar the yeast stopped + + + align:start position:0% +you ran out of sugar the yeast stopped +growing it was something connected here + + align:start position:0% +growing it was something connected here + + + align:start position:0% +growing it was something connected here +so he came up with the idea that the + + align:start position:0% +so he came up with the idea that the + + + align:start position:0% +so he came up with the idea that the +yeast were responsible for this + + align:start position:0% +yeast were responsible for this + + + align:start position:0% +yeast were responsible for this +conversion was happening when you made + + align:start position:0% +conversion was happening when you made + + + align:start position:0% +conversion was happening when you made +wine and it was further uh helped out on + + align:start position:0% +wine and it was further uh helped out on + + + align:start position:0% +wine and it was further uh helped out on +this because he discovered an + + align:start position:0% + + + + align:start position:0% + +alternative conversion in which C6 + + align:start position:0% +alternative conversion in which C6 + + + align:start position:0% +alternative conversion in which C6 +h126 went instead to give two molecules + + align:start position:0% +h126 went instead to give two molecules + + + align:start position:0% +h126 went instead to give two molecules +of ch3 CH + + align:start position:0% +of ch3 CH + + + align:start position:0% +of ch3 CH +o + + align:start position:0% +o + + + align:start position:0% +o +this molecule which you + + align:start position:0% +this molecule which you + + + align:start position:0% +this molecule which you +know is lactic acid it too has C6 + + align:start position:0% +know is lactic acid it too has C6 + + + align:start position:0% +know is lactic acid it too has C6 +h126 on both sides of the equation but + + align:start position:0% +h126 on both sides of the equation but + + + align:start position:0% +h126 on both sides of the equation but +it's a different molecule and what he + + align:start position:0% +it's a different molecule and what he + + + align:start position:0% +it's a different molecule and what he +found was that this is the lactic acid + + align:start position:0% +found was that this is the lactic acid + + + align:start position:0% +found was that this is the lactic acid +um you know it it's what's in yogurt + + align:start position:0% +um you know it it's what's in yogurt + + + align:start position:0% +um you know it it's what's in yogurt +that makes yogurt sour or if you + + align:start position:0% +that makes yogurt sour or if you + + + align:start position:0% +that makes yogurt sour or if you +exercise really hard and your muscles + + align:start position:0% +exercise really hard and your muscles + + + align:start position:0% +exercise really hard and your muscles +are sore that's because you accumulate + + align:start position:0% +are sore that's because you accumulate + + + align:start position:0% +are sore that's because you accumulate +lactic acid in your muscles and tell you + + align:start position:0% +lactic acid in your muscles and tell you + + + align:start position:0% +lactic acid in your muscles and tell you +why that is in the next lecture but what + + align:start position:0% +why that is in the next lecture but what + + + align:start position:0% +why that is in the next lecture but what +uh the other thing that uh pester + + align:start position:0% +uh the other thing that uh pester + + + align:start position:0% +uh the other thing that uh pester +realized that was when you got this + + align:start position:0% +realized that was when you got this + + + align:start position:0% +realized that was when you got this +alternative conversion you didn't have + + align:start position:0% +alternative conversion you didn't have + + + align:start position:0% +alternative conversion you didn't have +yeast present you had some other + + align:start position:0% +yeast present you had some other + + + align:start position:0% +yeast present you had some other +organism and so that was a huge Advance + + align:start position:0% +organism and so that was a huge Advance + + + align:start position:0% +organism and so that was a huge Advance +uh just and of practical value to the + + align:start position:0% +uh just and of practical value to the + + + align:start position:0% +uh just and of practical value to the +wine makers because they knew they had + + align:start position:0% +wine makers because they knew they had + + + align:start position:0% +wine makers because they knew they had +to have yeast in there to get wine and + + align:start position:0% +to have yeast in there to get wine and + + + align:start position:0% +to have yeast in there to get wine and +their problems were coming when some + + align:start position:0% +their problems were coming when some + + + align:start position:0% +their problems were coming when some +other organism that wasn't yeast got in + + align:start position:0% +other organism that wasn't yeast got in + + + align:start position:0% +other organism that wasn't yeast got in +there and it did something different + + align:start position:0% +there and it did something different + + + align:start position:0% +there and it did something different +with the sugar and made it into lactic + + align:start position:0% +with the sugar and made it into lactic + + + align:start position:0% +with the sugar and made it into lactic +acid and instead of making an end + + align:start position:0% +acid and instead of making an end + + + align:start position:0% +acid and instead of making an end +ethanol and and carbon dioxide so there + + align:start position:0% +ethanol and and carbon dioxide so there + + + align:start position:0% +ethanol and and carbon dioxide so there +was pastur working away on a on a + + align:start position:0% +was pastur working away on a on a + + + align:start position:0% +was pastur working away on a on a +practical problem and um it was a you + + align:start position:0% +practical problem and um it was a you + + + align:start position:0% +practical problem and um it was a you +know a really major advance to the wine + + align:start position:0% +know a really major advance to the wine + + + align:start position:0% +know a really major advance to the wine +making industry for him him to do this + + align:start position:0% +making industry for him him to do this + + + align:start position:0% +making industry for him him to do this +but it also then sort of + + align:start position:0% +but it also then sort of + + + align:start position:0% +but it also then sort of +unexpectedly led to uh another issue and + + align:start position:0% +unexpectedly led to uh another issue and + + + align:start position:0% +unexpectedly led to uh another issue and +that was why were the yeast doing this + + align:start position:0% +that was why were the yeast doing this + + + align:start position:0% +that was why were the yeast doing this +because one of the things that L not and + + align:start position:0% +because one of the things that L not and + + + align:start position:0% +because one of the things that L not and +Pastor noticed was that you you did this + + align:start position:0% + + + + align:start position:0% + +conversion the two + + align:start position:0% +conversion the two + + + align:start position:0% +conversion the two +ethanol plus two carbon dioxide but you + + align:start position:0% +ethanol plus two carbon dioxide but you + + + align:start position:0% +ethanol plus two carbon dioxide but you +could account for virtually all of the + + align:start position:0% +could account for virtually all of the + + + align:start position:0% +could account for virtually all of the +the carbons and hydrogens and oxygens uh + + align:start position:0% +the carbons and hydrogens and oxygens uh + + + align:start position:0% +the carbons and hydrogens and oxygens uh +that started out of sugar seemed like + + align:start position:0% +that started out of sugar seemed like + + + align:start position:0% +that started out of sugar seemed like +virtually all of them showed up in the + + align:start position:0% +virtually all of them showed up in the + + + align:start position:0% +virtually all of them showed up in the +uh in the ethanol and carbon dioxide so + + align:start position:0% +uh in the ethanol and carbon dioxide so + + + align:start position:0% +uh in the ethanol and carbon dioxide so +why was the yeast doing this and the I + + align:start position:0% +why was the yeast doing this and the I + + + align:start position:0% +why was the yeast doing this and the I +idea began to develop out of that was + + align:start position:0% +idea began to develop out of that was + + + align:start position:0% +idea began to develop out of that was +that the uh rather than being used to + + align:start position:0% +that the uh rather than being used to + + + align:start position:0% +that the uh rather than being used to +make biomass in which case you would + + align:start position:0% +make biomass in which case you would + + + align:start position:0% +make biomass in which case you would +have expected to see a whole lot of mass + + align:start position:0% +have expected to see a whole lot of mass + + + align:start position:0% +have expected to see a whole lot of mass +in the yeast cells and not so much up + + align:start position:0% +in the yeast cells and not so much up + + + align:start position:0% +in the yeast cells and not so much up +here that instead most of this sugar was + + align:start position:0% +here that instead most of this sugar was + + + align:start position:0% +here that instead most of this sugar was +being used to make energy and that + + align:start position:0% +being used to make energy and that + + + align:start position:0% +being used to make energy and that +somehow the cell was getting the energy + + align:start position:0% +somehow the cell was getting the energy + + + align:start position:0% +somehow the cell was getting the energy +necessary to do all that synthetic work + + align:start position:0% +necessary to do all that synthetic work + + + align:start position:0% +necessary to do all that synthetic work +in that involved in cell division by + + align:start position:0% +in that involved in cell division by + + + align:start position:0% +in that involved in cell division by +carrying out uh this + + align:start position:0% +carrying out uh this + + + align:start position:0% +carrying out uh this +conversion and there's a fundamental uh + + align:start position:0% +conversion and there's a fundamental uh + + + align:start position:0% +conversion and there's a fundamental uh +relationship then between chemical + + align:start position:0% +relationship then between chemical + + + align:start position:0% +relationship then between chemical +energy and whether a reaction uh can + + align:start position:0% +energy and whether a reaction uh can + + + align:start position:0% +energy and whether a reaction uh can +proceed and I'll just uh take it through + + align:start position:0% +proceed and I'll just uh take it through + + + align:start position:0% +proceed and I'll just uh take it through +and in a sort of your typical + + align:start position:0% +and in a sort of your typical + + + align:start position:0% +and in a sort of your typical +introductory chemistry reaction a plus b + + align:start position:0% +introductory chemistry reaction a plus b + + + align:start position:0% +introductory chemistry reaction a plus b +going to C plus d now if this re there + + align:start position:0% +going to C plus d now if this re there + + + align:start position:0% +going to C plus d now if this re there +are certain classes of reactions that + + align:start position:0% +are certain classes of reactions that + + + align:start position:0% +are certain classes of reactions that +will go almost to + + align:start position:0% + + + + align:start position:0% + +completion + + align:start position:0% +completion + + + align:start position:0% +completion +probably an overstatement it say it's to + + align:start position:0% +probably an overstatement it say it's to + + + align:start position:0% +probably an overstatement it say it's to +go to completion but it's effectively + + align:start position:0% +go to completion but it's effectively + + + align:start position:0% +go to completion but it's effectively +over here those are termed irreversible + + align:start position:0% +over here those are termed irreversible + + + align:start position:0% +over here those are termed irreversible +reactions and there are certainly are + + align:start position:0% +reactions and there are certainly are + + + align:start position:0% +reactions and there are certainly are +are some of them if I have hydrogen and + + align:start position:0% +are some of them if I have hydrogen and + + + align:start position:0% +are some of them if I have hydrogen and +oxygen and I little light a little match + + align:start position:0% +oxygen and I little light a little match + + + align:start position:0% +oxygen and I little light a little match +we pretty much go all the way to making + + align:start position:0% +we pretty much go all the way to making + + + align:start position:0% +we pretty much go all the way to making +water with a great big boom and no + + align:start position:0% +water with a great big boom and no + + + align:start position:0% +water with a great big boom and no +hydrogen or not much hydrogen oxygen + + align:start position:0% +hydrogen or not much hydrogen oxygen + + + align:start position:0% +hydrogen or not much hydrogen oxygen +left on the other side however most + + align:start position:0% +left on the other side however most + + + align:start position:0% +left on the other side however most +reactions that one finds in nature don't + + align:start position:0% +reactions that one finds in nature don't + + + align:start position:0% +reactions that one finds in nature don't +have that quality instead they're going + + align:start position:0% +have that quality instead they're going + + + align:start position:0% +have that quality instead they're going +forward at some rate and back at another + + align:start position:0% +forward at some rate and back at another + + + align:start position:0% +forward at some rate and back at another +and they reach eventually an + + align:start position:0% + + + + align:start position:0% + +equilibrium it's + + align:start position:0% +equilibrium it's + + + align:start position:0% +equilibrium it's +characterized by what's known as an + + align:start position:0% +characterized by what's known as an + + + align:start position:0% +characterized by what's known as an +equilibrium constant which is + + align:start position:0% +equilibrium constant which is + + + align:start position:0% +equilibrium constant which is +the product of the + + align:start position:0% +the product of the + + + align:start position:0% +the product of the +concentrations of the products over the + + align:start position:0% +concentrations of the products over the + + + align:start position:0% +concentrations of the products over the +product of the + + align:start position:0% +product of the + + + align:start position:0% +product of the +concentration of the reactants and + + align:start position:0% +concentration of the reactants and + + + align:start position:0% +concentration of the reactants and +that's a char eristic of every uh + + align:start position:0% +that's a char eristic of every uh + + + align:start position:0% +that's a char eristic of every uh +particular chemical reaction and we + + align:start position:0% +particular chemical reaction and we + + + align:start position:0% +particular chemical reaction and we +really have to worry about this uh in + + align:start position:0% +really have to worry about this uh in + + + align:start position:0% +really have to worry about this uh in +biology because if everything was + + align:start position:0% +biology because if everything was + + + align:start position:0% +biology because if everything was +irreversible that would fine but in + + align:start position:0% +irreversible that would fine but in + + + align:start position:0% +irreversible that would fine but in +order to do all this synthetic work you + + align:start position:0% +order to do all this synthetic work you + + + align:start position:0% +order to do all this synthetic work you +have to um deal with a lot of reactions + + align:start position:0% +have to um deal with a lot of reactions + + + align:start position:0% +have to um deal with a lot of reactions +that aren't going to go to completion + + align:start position:0% +that aren't going to go to completion + + + align:start position:0% +that aren't going to go to completion +and nature has had to figure out a way + + align:start position:0% +and nature has had to figure out a way + + + align:start position:0% +and nature has had to figure out a way +of uh of doing that just the same way + + align:start position:0% +of uh of doing that just the same way + + + align:start position:0% +of uh of doing that just the same way +that Bridges and buildings don't + + align:start position:0% +that Bridges and buildings don't + + + align:start position:0% +that Bridges and buildings don't +spontaneously assemble in Engineers on + + align:start position:0% +spontaneously assemble in Engineers on + + + align:start position:0% +spontaneously assemble in Engineers on +earth have had to work out ways of + + align:start position:0% +earth have had to work out ways of + + + align:start position:0% +earth have had to work out ways of +putting all of those things together so + + align:start position:0% +putting all of those things together so + + + align:start position:0% +putting all of those things together so +at some level you see the same kind of + + align:start position:0% +at some level you see the same kind of + + + align:start position:0% +at some level you see the same kind of +problem now there's a there's a a way of + + align:start position:0% +problem now there's a there's a a way of + + + align:start position:0% +problem now there's a there's a a way of +expressing this energy associated with a + + align:start position:0% +expressing this energy associated with a + + + align:start position:0% +expressing this energy associated with a +chemical reaction that can be used to + + align:start position:0% +chemical reaction that can be used to + + + align:start position:0% +chemical reaction that can be used to +directly calculate whether uh a reaction + + align:start position:0% +directly calculate whether uh a reaction + + + align:start position:0% +directly calculate whether uh a reaction +is going to go or and how far it will go + + align:start position:0% +is going to go or and how far it will go + + + align:start position:0% +is going to go or and how far it will go +and um the person who did this work is + + align:start position:0% +and um the person who did this work is + + + align:start position:0% +and um the person who did this work is +another person who's on uh um one of the + + align:start position:0% +another person who's on uh um one of the + + + align:start position:0% +another person who's on uh um one of the +MIT buildings uh it was josea Gibbs who + + align:start position:0% +MIT buildings uh it was josea Gibbs who + + + align:start position:0% +MIT buildings uh it was josea Gibbs who +was a uh faculty member uh chemist who + + align:start position:0% +was a uh faculty member uh chemist who + + + align:start position:0% +was a uh faculty member uh chemist who +worked at Yale in the + + align:start position:0% +worked at Yale in the + + + align:start position:0% +worked at Yale in the +1980s 18 excuse me 18 uh 1800s and he + + align:start position:0% +1980s 18 excuse me 18 uh 1800s and he + + + align:start position:0% +1980s 18 excuse me 18 uh 1800s and he +um came up with expression that's now + + align:start position:0% +um came up with expression that's now + + + align:start position:0% +um came up with expression that's now +known as Gibs free + + align:start position:0% + + + + align:start position:0% + +energy and this is what's important + + align:start position:0% +energy and this is what's important + + + align:start position:0% +energy and this is what's important +about this uh this way of talking about + + align:start position:0% +about this uh this way of talking about + + + align:start position:0% +about this uh this way of talking about +the energy ex um Associated change + + align:start position:0% +the energy ex um Associated change + + + align:start position:0% +the energy ex um Associated change +associated with the chemical reaction is + + align:start position:0% +associated with the chemical reaction is + + + align:start position:0% +associated with the chemical reaction is +it combines not only uh the considers + + align:start position:0% +it combines not only uh the considers + + + align:start position:0% +it combines not only uh the considers +not only the internal energy of the + + align:start position:0% +not only the internal energy of the + + + align:start position:0% +not only the internal energy of the +system but also the change in disorder + + align:start position:0% +system but also the change in disorder + + + align:start position:0% +system but also the change in disorder +or another way of saying that for those + + align:start position:0% +or another way of saying that for those + + + align:start position:0% +or another way of saying that for those +of you who've run into the laws of + + align:start position:0% +of you who've run into the laws of + + + align:start position:0% +of you who've run into the laws of +thermodynamics it combines the first and + + align:start position:0% +thermodynamics it combines the first and + + + align:start position:0% +thermodynamics it combines the first and +second laws of thermodynamics and you + + align:start position:0% +second laws of thermodynamics and you + + + align:start position:0% +second laws of thermodynamics and you +have to consider both of those you're + + align:start position:0% +have to consider both of those you're + + + align:start position:0% +have to consider both of those you're +going to consider whether a uh a + + align:start position:0% +going to consider whether a uh a + + + align:start position:0% +going to consider whether a uh a +reaction will go and and + + align:start position:0% +reaction will go and and + + + align:start position:0% +reaction will go and and +it's that you can't measure an absolute + + align:start position:0% +it's that you can't measure an absolute + + + align:start position:0% +it's that you can't measure an absolute +free energy but you can measure a + + align:start position:0% + + + + align:start position:0% + +change and this was this is the equation + + align:start position:0% +change and this was this is the equation + + + align:start position:0% +change and this was this is the equation +it's uh the change associated with with + + align:start position:0% +it's uh the change associated with with + + + align:start position:0% +it's uh the change associated with with +a chemical reaction is is equal to the + + align:start position:0% +a chemical reaction is is equal to the + + + align:start position:0% +a chemical reaction is is equal to the +change associated with the chemical + + align:start position:0% +change associated with the chemical + + + align:start position:0% +change associated with the chemical +reaction under some set of standard + + align:start position:0% +reaction under some set of standard + + + align:start position:0% +reaction under some set of standard +conditions times RT times the log of the + + align:start position:0% +conditions times RT times the log of the + + + align:start position:0% +conditions times RT times the log of the +concentration of the products multiplied + + align:start position:0% +concentration of the products multiplied + + + align:start position:0% +concentration of the products multiplied +together over the concent ation of the + + align:start position:0% + + + + align:start position:0% + +reactants so if we just go to the same + + align:start position:0% +reactants so if we just go to the same + + + align:start position:0% +reactants so if we just go to the same +example we were just thinking about the + + align:start position:0% +example we were just thinking about the + + + align:start position:0% +example we were just thinking about the +assoc the energy change with that + + align:start position:0% +assoc the energy change with that + + + align:start position:0% +assoc the energy change with that +reaction that we were + + align:start position:0% +reaction that we were + + + align:start position:0% +reaction that we were +considering would have + + align:start position:0% + + + + align:start position:0% + +been + + align:start position:0% + + + + align:start position:0% + +this + + align:start position:0% +this + + + align:start position:0% +this +so this is the energy chain + + align:start position:0% + + + + align:start position:0% + +so associated with the + + align:start position:0% + + + + align:start position:0% + +concentrations the reactants and + + align:start position:0% +concentrations the reactants and + + + align:start position:0% +concentrations the reactants and +products that we're + + align:start position:0% + + + + align:start position:0% + +considering this is the energy + + align:start position:0% + + + + align:start position:0% + +change under + + align:start position:0% +change under + + + align:start position:0% +change under +standard what term standard + + align:start position:0% +standard what term standard + + + align:start position:0% +standard what term standard +conditions where every thing the each + + align:start position:0% +conditions where every thing the each + + + align:start position:0% +conditions where every thing the each +reactant each product is present under + + align:start position:0% +reactant each product is present under + + + align:start position:0% +reactant each product is present under +one molar concentrations so not + + align:start position:0% +one molar concentrations so not + + + align:start position:0% +one molar concentrations so not +something you'd ever find in most cases + + align:start position:0% +something you'd ever find in most cases + + + align:start position:0% +something you'd ever find in most cases +but it's a frame of reference and then + + align:start position:0% +but it's a frame of reference and then + + + align:start position:0% +but it's a frame of reference and then +this is the gas constant the universal + + align:start position:0% +this is the gas constant the universal + + + align:start position:0% +this is the gas constant the universal +gas + + align:start position:0% +gas + + + align:start position:0% +gas +constant + + align:start position:0% + + + + align:start position:0% + +which is 2 * + + align:start position:0% + + + + align:start position:0% + +10-3 kilo + + align:start position:0% +10-3 kilo + + + align:start position:0% +10-3 kilo +calories per mole per degree Kelvin the + + align:start position:0% +calories per mole per degree Kelvin the + + + align:start position:0% +calories per mole per degree Kelvin the +temperature in absolute this is the + + align:start position:0% +temperature in absolute this is the + + + align:start position:0% +temperature in absolute this is the +temp in degrees + + align:start position:0% +temp in degrees + + + align:start position:0% +temp in degrees +Kelvin and the temperature for most + + align:start position:0% +Kelvin and the temperature for most + + + align:start position:0% +Kelvin and the temperature for most +biology most life is around 25° Cen so + + align:start position:0% +biology most life is around 25° Cen so + + + align:start position:0% +biology most life is around 25° Cen so +that's equal to + + align:start position:0% +that's equal to + + + align:start position:0% +that's equal to +298° + + align:start position:0% +298° + + + align:start position:0% +298° +Kelvin which is about equal to 300° + + align:start position:0% +Kelvin which is about equal to 300° + + + align:start position:0% +Kelvin which is about equal to 300° +Kelvin so for most and since the range + + align:start position:0% +Kelvin so for most and since the range + + + align:start position:0% +Kelvin so for most and since the range +in which life can occur on an absolute + + align:start position:0% +in which life can occur on an absolute + + + align:start position:0% +in which life can occur on an absolute +temperature scale is really pretty small + + align:start position:0% +temperature scale is really pretty small + + + align:start position:0% +temperature scale is really pretty small +and sort of fluctuates in only very + + align:start position:0% +and sort of fluctuates in only very + + + align:start position:0% +and sort of fluctuates in only very +minor ways around 25° Centigrade then + + align:start position:0% +minor ways around 25° Centigrade then + + + align:start position:0% +minor ways around 25° Centigrade then +for most of the biological reactions + + align:start position:0% +for most of the biological reactions + + + align:start position:0% +for most of the biological reactions +we'll be thinking about this RT uh + + align:start position:0% +we'll be thinking about this RT uh + + + align:start position:0% +we'll be thinking about this RT uh +number number is is about 6 K + + align:start position:0% +number number is is about 6 K + + + align:start position:0% +number number is is about 6 K +Cals per per + + align:start position:0% + + + + align:start position:0% + +mole now biochemists actually have a + + align:start position:0% +mole now biochemists actually have a + + + align:start position:0% +mole now biochemists actually have a +special form of free energy they use + + align:start position:0% +special form of free energy they use + + + align:start position:0% +special form of free energy they use +which we put a a Delta + + align:start position:0% +which we put a a Delta + + + align:start position:0% +which we put a a Delta +G Prime and that's in this case the + + align:start position:0% +G Prime and that's in this case the + + + align:start position:0% +G Prime and that's in this case the +Delta G Prime is equal to Delta G Prime + + align:start position:0% +Delta G Prime is equal to Delta G Prime + + + align:start position:0% +Delta G Prime is equal to Delta G Prime +under a set of standard conditions plus + + align:start position:0% +under a set of standard conditions plus + + + align:start position:0% +under a set of standard conditions plus +RT + + align:start position:0% +RT + + + align:start position:0% +RT +natural log of C + + align:start position:0% +natural log of C + + + align:start position:0% +natural log of C +products over the + + align:start position:0% + + + + align:start position:0% + +reactants but the assumption is made + + align:start position:0% +reactants but the assumption is made + + + align:start position:0% +reactants but the assumption is made +that the + + align:start position:0% +that the + + + align:start position:0% +that the +reactions the + + align:start position:0% +reactions the + + + align:start position:0% +reactions the +reaction is in + + align:start position:0% + + + + align:start position:0% + +water which is I mentioned the other day + + align:start position:0% +water which is I mentioned the other day + + + align:start position:0% +water which is I mentioned the other day +is 55 more + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% + + + + align:start position:0% + +this is this is the degree celsius I've + + align:start position:0% +this is this is the degree celsius I've + + + align:start position:0% +this is this is the degree celsius I've +just expressed it in degrees + + align:start position:0% + + + + align:start position:0% + +Kelvin sorry my + + align:start position:0% +Kelvin sorry my + + + align:start position:0% +Kelvin sorry my +mistake excuse + + align:start position:0% +mistake excuse + + + align:start position:0% +mistake excuse +me because I was wrong that's why okay + + align:start position:0% +me because I was wrong that's why okay + + + align:start position:0% +me because I was wrong that's why okay +um thanks for catching that uh all right + + align:start position:0% +um thanks for catching that uh all right + + + align:start position:0% +um thanks for catching that uh all right +so under the so water is very + + align:start position:0% +so under the so water is very + + + align:start position:0% +so under the so water is very +concentrated and so under these + + align:start position:0% +concentrated and so under these + + + align:start position:0% +concentrated and so under these +conditions the other convention is then + + align:start position:0% +conditions the other convention is then + + + align:start position:0% +conditions the other convention is then +you can + + align:start position:0% +you can + + + align:start position:0% +you can +set the hydrogen ions to and and water + + align:start position:0% +set the hydrogen ions to and and water + + + align:start position:0% +set the hydrogen ions to and and water +molecules to one and you don't have to + + align:start position:0% +molecules to one and you don't have to + + + align:start position:0% +molecules to one and you don't have to +think about them when you're we're doing + + align:start position:0% +think about them when you're we're doing + + + align:start position:0% +think about them when you're we're doing +this this is a convention that that uh + + align:start position:0% +this this is a convention that that uh + + + align:start position:0% +this this is a convention that that uh +that bio that biochemists do now this + + align:start position:0% +that bio that biochemists do now this + + + align:start position:0% +that bio that biochemists do now this +free + + align:start position:0% +free + + + align:start position:0% +free +energy the the the Delta G gies free + + align:start position:0% +energy the the the Delta G gies free + + + align:start position:0% +energy the the the Delta G gies free +energy is a thermodynamic + + align:start position:0% + + + + align:start position:0% + +property and I I want to I'll just give + + align:start position:0% +property and I I want to I'll just give + + + align:start position:0% +property and I I want to I'll just give +share with you mean the same visual + + align:start position:0% +share with you mean the same visual + + + align:start position:0% +share with you mean the same visual +image I've had since I was in undergrad + + align:start position:0% +image I've had since I was in undergrad + + + align:start position:0% +image I've had since I was in undergrad +which I think is not a bad way of + + align:start position:0% +which I think is not a bad way of + + + align:start position:0% +which I think is not a bad way of +thinking about it trying to un + + align:start position:0% +thinking about it trying to un + + + align:start position:0% +thinking about it trying to un +understand what happens that if we have + + align:start position:0% +understand what happens that if we have + + + align:start position:0% +understand what happens that if we have +a a plot of + + align:start position:0% +a a plot of + + + align:start position:0% +a a plot of +the the free + + align:start position:0% +the the free + + + align:start position:0% +the the free +energy as a function of what happens as + + align:start position:0% +energy as a function of what happens as + + + align:start position:0% +energy as a function of what happens as +the reaction goes along so that we + + align:start position:0% +the reaction goes along so that we + + + align:start position:0% +the reaction goes along so that we +have a + b here and C+ D down here uh + + align:start position:0% +have a + b here and C+ D down here uh + + + align:start position:0% +have a + b here and C+ D down here uh +when you go from reaction to products + + align:start position:0% +when you go from reaction to products + + + align:start position:0% +when you go from reaction to products +way of of drawn it there's free en some + + align:start position:0% +way of of drawn it there's free en some + + + align:start position:0% +way of of drawn it there's free en some +kind of energy is given off in this kind + + align:start position:0% +kind of energy is given off in this kind + + + align:start position:0% +kind of energy is given off in this kind +of reaction and the if you know that if + + align:start position:0% +of reaction and the if you know that if + + + align:start position:0% +of reaction and the if you know that if +you know that you will know then that + + align:start position:0% +you know that you will know then that + + + align:start position:0% +you know that you will know then that +the the reaction will be able to go + + align:start position:0% +the the reaction will be able to go + + + align:start position:0% +the the reaction will be able to go +forward because it's able to give off + + align:start position:0% +forward because it's able to give off + + + align:start position:0% +forward because it's able to give off +energy just just the same way hydrogen + + align:start position:0% +energy just just the same way hydrogen + + + align:start position:0% +energy just just the same way hydrogen +and oxygen give off a lot of heat and + + align:start position:0% +and oxygen give off a lot of heat and + + + align:start position:0% +and oxygen give off a lot of heat and +stuff and you know that reaction really + + align:start position:0% +stuff and you know that reaction really + + + align:start position:0% +stuff and you know that reaction really +goes a long way to completion so it's + + align:start position:0% +goes a long way to completion so it's + + + align:start position:0% +goes a long way to completion so it's +kind of as if uh you were out here on + + align:start position:0% +kind of as if uh you were out here on + + + align:start position:0% +kind of as if uh you were out here on +your spring break on your + + align:start position:0% +your spring break on your + + + align:start position:0% +your spring break on your +skis are ready to go down the uh Black + + align:start position:0% +skis are ready to go down the uh Black + + + align:start position:0% +skis are ready to go down the uh Black +Diamond Hill and it you you can sort of + + align:start position:0% +Diamond Hill and it you you can sort of + + + align:start position:0% +Diamond Hill and it you you can sort of +see it what what happened now because + + align:start position:0% +see it what what happened now because + + + align:start position:0% +see it what what happened now because +it's a thermodynamic property it doesn't + + align:start position:0% +it's a thermodynamic property it doesn't + + + align:start position:0% +it's a thermodynamic property it doesn't +matter what route you take to get from + + align:start position:0% +matter what route you take to get from + + + align:start position:0% +matter what route you take to get from +the reactants to the products so if you + + align:start position:0% +the reactants to the products so if you + + + align:start position:0% +the reactants to the products so if you +go down the Double Diamond slope or you + + align:start position:0% +go down the Double Diamond slope or you + + + align:start position:0% +go down the Double Diamond slope or you +go down the the bunny slope you still + + align:start position:0% +go down the the bunny slope you still + + + align:start position:0% +go down the the bunny slope you still +end up with the same amount of energy + + align:start position:0% +end up with the same amount of energy + + + align:start position:0% +end up with the same amount of energy +coming out of the reaction and that's + + align:start position:0% +coming out of the reaction and that's + + + align:start position:0% +coming out of the reaction and that's +important because if if if that wasn't + + align:start position:0% +important because if if if that wasn't + + + align:start position:0% +important because if if if that wasn't +true you could make a perpetual motion + + align:start position:0% +true you could make a perpetual motion + + + align:start position:0% +true you could make a perpetual motion +machine and you'd be very rich um the + + align:start position:0% +machine and you'd be very rich um the + + + align:start position:0% +machine and you'd be very rich um the +second thing that's important is that + + align:start position:0% +second thing that's important is that + + + align:start position:0% +second thing that's important is that +this + + align:start position:0% + + + + align:start position:0% + +uh the free energy will tell + + align:start position:0% +uh the free energy will tell + + + align:start position:0% +uh the free energy will tell +you what would happen if if the reaction + + align:start position:0% +you what would happen if if the reaction + + + align:start position:0% +you what would happen if if the reaction +went but it will not tell you whether it + + align:start position:0% +went but it will not tell you whether it + + + align:start position:0% +went but it will not tell you whether it +can go if I did a demo here and I + + align:start position:0% +can go if I did a demo here and I + + + align:start position:0% +can go if I did a demo here and I +brought some hydrogen and some oxygen + + align:start position:0% +brought some hydrogen and some oxygen + + + align:start position:0% +brought some hydrogen and some oxygen +and I mixed them together in a vessel in + + align:start position:0% +and I mixed them together in a vessel in + + + align:start position:0% +and I mixed them together in a vessel in +the front of the class we could all sit + + align:start position:0% +the front of the class we could all sit + + + align:start position:0% +the front of the class we could all sit +here waiting for it to explode but the + + align:start position:0% +here waiting for it to explode but the + + + align:start position:0% +here waiting for it to explode but the +likelihood is we would sit here for a + + align:start position:0% +likelihood is we would sit here for a + + + align:start position:0% +likelihood is we would sit here for a +very very long time and not see an + + align:start position:0% +very very long time and not see an + + + align:start position:0% +very very long time and not see an +explosion right and the reason is that + + align:start position:0% +explosion right and the reason is that + + + align:start position:0% +explosion right and the reason is that +in order to get that hydrogen oxygen to + + align:start position:0% +in order to get that hydrogen oxygen to + + + align:start position:0% +in order to get that hydrogen oxygen to +close enough together we had to give + + align:start position:0% +close enough together we had to give + + + align:start position:0% +close enough together we had to give +them some extra energy and push them so + + align:start position:0% +them some extra energy and push them so + + + align:start position:0% +them some extra energy and push them so +they overcome repulsion and stuff so if + + align:start position:0% +they overcome repulsion and stuff so if + + + align:start position:0% +they overcome repulsion and stuff so if +you were uh out here on your on your + + align:start position:0% +you were uh out here on your on your + + + align:start position:0% +you were uh out here on your on your +skis + + align:start position:0% +skis + + + align:start position:0% +skis +again getting all ready to go but in + + align:start position:0% +again getting all ready to go but in + + + align:start position:0% +again getting all ready to go but in +fact you got off at the wrong uh stop on + + align:start position:0% +fact you got off at the wrong uh stop on + + + align:start position:0% +fact you got off at the wrong uh stop on +the ski lift and you were there even + + align:start position:0% +the ski lift and you were there even + + + align:start position:0% +the ski lift and you were there even +though there would be energy getting + + align:start position:0% +though there would be energy getting + + + align:start position:0% +though there would be energy getting +down from here you're it's not going to + + align:start position:0% +down from here you're it's not going to + + + align:start position:0% +down from here you're it's not going to +happen at any discernable rate given the + + align:start position:0% +happen at any discernable rate given the + + + align:start position:0% +happen at any discernable rate given the +sort of little bounce and energy you + + align:start position:0% +sort of little bounce and energy you + + + align:start position:0% +sort of little bounce and energy you +have in your normal uh in your normal + + align:start position:0% +have in your normal uh in your normal + + + align:start position:0% +have in your normal uh in your normal +Liv so what we're doing doing when we do + + align:start position:0% +Liv so what we're doing doing when we do + + + align:start position:0% +Liv so what we're doing doing when we do +hydrogen oxygen we're giving by putting + + align:start position:0% +hydrogen oxygen we're giving by putting + + + align:start position:0% +hydrogen oxygen we're giving by putting +a match into it or something we're + + align:start position:0% +a match into it or something we're + + + align:start position:0% +a match into it or something we're +giving it enough energy that actually a + + align:start position:0% +giving it enough energy that actually a + + + align:start position:0% +giving it enough energy that actually a +few of the molecules get up here they + + align:start position:0% +few of the molecules get up here they + + + align:start position:0% +few of the molecules get up here they +drop down then they give up so much + + align:start position:0% +drop down then they give up so much + + + align:start position:0% +drop down then they give up so much +energy and heat that all the rest of + + align:start position:0% +energy and heat that all the rest of + + + align:start position:0% +energy and heat that all the rest of +them get pushed up and the thing goes + + align:start position:0% +them get pushed up and the thing goes + + + align:start position:0% +them get pushed up and the thing goes +but that's sort of a not a not a bad way + + align:start position:0% +but that's sort of a not a not a bad way + + + align:start position:0% +but that's sort of a not a not a bad way +of thinking about it and when we're + + align:start position:0% +of thinking about it and when we're + + + align:start position:0% +of thinking about it and when we're +going to talk in a minute about what + + align:start position:0% +going to talk in a minute about what + + + align:start position:0% +going to talk in a minute about what +determines how fast reactions go not how + + align:start position:0% +determines how fast reactions go not how + + + align:start position:0% +determines how fast reactions go not how +not whether they go or not and then of + + align:start position:0% +not whether they go or not and then of + + + align:start position:0% +not whether they go or not and then of +course we're going to have that point + + align:start position:0% +course we're going to have that point + + + align:start position:0% +course we're going to have that point +we're going to have to worry about this + + align:start position:0% +we're going to have to worry about this + + + align:start position:0% +we're going to have to worry about this +about this issue but before that um what + + align:start position:0% +about this issue but before that um what + + + align:start position:0% +about this issue but before that um what +I want to show you is that there's a + + align:start position:0% +I want to show you is that there's a + + + align:start position:0% +I want to show you is that there's a +direct + + align:start position:0% +direct + + + align:start position:0% +direct +relationship between this Gibs free uh + + align:start position:0% +relationship between this Gibs free uh + + + align:start position:0% +relationship between this Gibs free uh +Gibs free energy and the equilibrium + + align:start position:0% +Gibs free energy and the equilibrium + + + align:start position:0% +Gibs free energy and the equilibrium +constant so um so we have + + align:start position:0% +constant so um so we have + + + align:start position:0% +constant so um so we have +this well what we could do is we have + + align:start position:0% +this well what we could do is we have + + + align:start position:0% +this well what we could do is we have +you you have the reaction over there so + + align:start position:0% +you you have the reaction over there so + + + align:start position:0% +you you have the reaction over there so +let's consider that reaction has come to + + align:start position:0% +let's consider that reaction has come to + + + align:start position:0% +let's consider that reaction has come to +equilibrium and that means there'll be + + align:start position:0% +equilibrium and that means there'll be + + + align:start position:0% +equilibrium and that means there'll be +no further uh energy change + + align:start position:0% +no further uh energy change + + + align:start position:0% +no further uh energy change +uh so we'll just set the Delta G to zero + + align:start position:0% +uh so we'll just set the Delta G to zero + + + align:start position:0% +uh so we'll just set the Delta G to zero +and that would mean then that Delta G + + align:start position:0% +and that would mean then that Delta G + + + align:start position:0% +and that would mean then that Delta G +Prime 0 is equal to minus + + align:start position:0% + + + + align:start position:0% + +rtation C over D over + + align:start position:0% + + + + align:start position:0% + +concentration a b um you'll recognize + + align:start position:0% +concentration a b um you'll recognize + + + align:start position:0% +concentration a b um you'll recognize +this that's the equilibrium constant + + align:start position:0% +this that's the equilibrium constant + + + align:start position:0% +this that's the equilibrium constant +right so oop sorry there's a natural log + + align:start position:0% +right so oop sorry there's a natural log + + + align:start position:0% +right so oop sorry there's a natural log +in here didn't get it + + align:start position:0% +in here didn't get it + + + align:start position:0% +in here didn't get it +in okay so which is equal to minus RT + + align:start position:0% +in okay so which is equal to minus RT + + + align:start position:0% +in okay so which is equal to minus RT +the natural + + align:start position:0% +the natural + + + align:start position:0% +the natural +log of the equilibrium constant or the + + align:start position:0% +log of the equilibrium constant or the + + + align:start position:0% +log of the equilibrium constant or the +natural log of the equilibrium constant + + align:start position:0% +natural log of the equilibrium constant + + + align:start position:0% +natural log of the equilibrium constant +is is equal to minus Delta G Prime 0/ RT + + align:start position:0% +is is equal to minus Delta G Prime 0/ RT + + + align:start position:0% +is is equal to minus Delta G Prime 0/ RT +or another way of saying that is the K + + align:start position:0% +or another way of saying that is the K + + + align:start position:0% +or another way of saying that is the K +equilibrium is equal e + + align:start position:0% +equilibrium is equal e + + + align:start position:0% +equilibrium is equal e +Theus Delta G Prime + + align:start position:0% +Theus Delta G Prime + + + align:start position:0% +Theus Delta G Prime +0 over RT + + align:start position:0% +0 over RT + + + align:start position:0% +0 over RT +so if you think back to the consequences + + align:start position:0% +so if you think back to the consequences + + + align:start position:0% +so if you think back to the consequences +of an equilibrium constant if the + + align:start position:0% +of an equilibrium constant if the + + + align:start position:0% +of an equilibrium constant if the +reaction is going to go almost all the + + align:start position:0% +reaction is going to go almost all the + + + align:start position:0% +reaction is going to go almost all the +way then they're going to be mostly re + + align:start position:0% +way then they're going to be mostly re + + + align:start position:0% +way then they're going to be mostly re +mostly products very few reactants so + + align:start position:0% +mostly products very few reactants so + + + align:start position:0% +mostly products very few reactants so +the K equilibrium will be large so if a + + align:start position:0% +the K equilibrium will be large so if a + + + align:start position:0% +the K equilibrium will be large so if a +reaction is going to go a long way then + + align:start position:0% +reaction is going to go a long way then + + + align:start position:0% +reaction is going to go a long way then +the the equilibrium constant will be + + align:start position:0% +the the equilibrium constant will be + + + align:start position:0% +the the equilibrium constant will be +large and in order for an equilibrium + + align:start position:0% +large and in order for an equilibrium + + + align:start position:0% +large and in order for an equilibrium +constant to be uh large large then this + + align:start position:0% +constant to be uh large large then this + + + align:start position:0% +constant to be uh large large then this +Delta G is going to have to have a large + + align:start position:0% +Delta G is going to have to have a large + + + align:start position:0% +Delta G is going to have to have a large +a large negative sign so if the + + align:start position:0% + + + + align:start position:0% + +reaction is + + align:start position:0% + + + + align:start position:0% + +favorable then K equilibrium will be + + align:start position:0% +favorable then K equilibrium will be + + + align:start position:0% +favorable then K equilibrium will be +large and uh the Delta G Prime Z will + + align:start position:0% +large and uh the Delta G Prime Z will + + + align:start position:0% +large and uh the Delta G Prime Z will +have + + align:start position:0% +have + + + align:start position:0% +have +at least within the scale of an + + align:start position:0% +at least within the scale of an + + + align:start position:0% +at least within the scale of an +activation energy a large + + align:start position:0% + + + + align:start position:0% + +negative value and let me give you a + + align:start position:0% +negative value and let me give you a + + + align:start position:0% +negative value and let me give you a +couple of + + align:start position:0% +couple of + + + align:start position:0% +couple of +examples when we talked + + align:start position:0% +examples when we talked + + + align:start position:0% +examples when we talked +about carbohydrates I briefly told you + + align:start position:0% +about carbohydrates I briefly told you + + + align:start position:0% +about carbohydrates I briefly told you +sucrose was a what we call a + + align:start position:0% +sucrose was a what we call a + + + align:start position:0% +sucrose was a what we call a +disaccharide Two Sugars join + + align:start position:0% +disaccharide Two Sugars join + + + align:start position:0% +disaccharide Two Sugars join +together how do we Jo what do we do when + + align:start position:0% +together how do we Jo what do we do when + + + align:start position:0% +together how do we Jo what do we do when +we join two things together pretty much + + align:start position:0% +we join two things together pretty much + + + align:start position:0% +we join two things together pretty much +usually in nature you split out a + + align:start position:0% +usually in nature you split out a + + + align:start position:0% +usually in nature you split out a +molecule of water so we take a molecule + + align:start position:0% +molecule of water so we take a molecule + + + align:start position:0% +molecule of water so we take a molecule +of glucose a molecule of fructose both + + align:start position:0% +of glucose a molecule of fructose both + + + align:start position:0% +of glucose a molecule of fructose both +carbohydrates both stick them together + + align:start position:0% +carbohydrates both stick them together + + + align:start position:0% +carbohydrates both stick them together +we get table sugar if we want to reverse + + align:start position:0% +we get table sugar if we want to reverse + + + align:start position:0% +we get table sugar if we want to reverse +that reaction we have to put in a + + align:start position:0% +that reaction we have to put in a + + + align:start position:0% +that reaction we have to put in a +molecule of water and we can run it the + + align:start position:0% +molecule of water and we can run it the + + + align:start position:0% +molecule of water and we can run it the +other way we get + + align:start position:0% + + + + align:start position:0% + +glucose plus fructose the K equilibrium + + align:start position:0% +glucose plus fructose the K equilibrium + + + align:start position:0% +glucose plus fructose the K equilibrium +for that reaction is + + align:start position:0% +for that reaction is + + + align:start position:0% +for that reaction is +140,000 the um + + align:start position:0% +140,000 the um + + + align:start position:0% +140,000 the um +the Delta G Prime + + align:start position:0% + + + + align:start position:0% + +0 is min - 7 kilo calories per + + align:start position:0% +0 is min - 7 kilo calories per + + + align:start position:0% +0 is min - 7 kilo calories per +mole if we think about so that's an + + align:start position:0% +mole if we think about so that's an + + + align:start position:0% +mole if we think about so that's an +example of what I was just telling a + + align:start position:0% +example of what I was just telling a + + + align:start position:0% +example of what I was just telling a +fairly large negative value we think + + align:start position:0% +fairly large negative value we think + + + align:start position:0% +fairly large negative value we think +about a reaction that's + + align:start position:0% +about a reaction that's + + + align:start position:0% +about a reaction that's +not uh + + align:start position:0% +not uh + + + align:start position:0% +not uh +favorable here's acetic + + align:start position:0% +favorable here's acetic + + + align:start position:0% +favorable here's acetic +acid that's what makes vinegar sour and + + align:start position:0% +acid that's what makes vinegar sour and + + + align:start position:0% +acid that's what makes vinegar sour and +it can the hydrogen ion can come off + + align:start position:0% + + + + align:start position:0% + +here to give you a hydrogen ion and the + + align:start position:0% +here to give you a hydrogen ion and the + + + align:start position:0% +here to give you a hydrogen ion and the +negative ion of acetic acid or or + + align:start position:0% +negative ion of acetic acid or or + + + align:start position:0% +negative ion of acetic acid or or +acetate ion the uh equilibrium constant + + align:start position:0% +acetate ion the uh equilibrium constant + + + align:start position:0% +acetate ion the uh equilibrium constant +for that + + align:start position:0% +for that + + + align:start position:0% +for that +one is what is it two I + + align:start position:0% +one is what is it two I + + + align:start position:0% +one is what is it two I +think 2 * + + align:start position:0% + + + + align:start position:0% + +10us five so only a little tiny bit of + + align:start position:0% +10us five so only a little tiny bit of + + + align:start position:0% +10us five so only a little tiny bit of +the + + align:start position:0% +the + + + align:start position:0% +the +acidic acid actually ionizes and the K + + align:start position:0% +acidic acid actually ionizes and the K + + + align:start position:0% +acidic acid actually ionizes and the K +equilibrium constant then oh excuse me + + align:start position:0% +equilibrium constant then oh excuse me + + + align:start position:0% +equilibrium constant then oh excuse me +the um the uh Delta G Prime Z is plus + + align:start position:0% + + + + align:start position:0% + +6.3 kilo calories uh per mole so it's + + align:start position:0% +6.3 kilo calories uh per mole so it's + + + align:start position:0% +6.3 kilo calories uh per mole so it's +some they're buried in this example is + + align:start position:0% +some they're buried in this example is + + + align:start position:0% +some they're buried in this example is +not only an showing you that a fav + + align:start position:0% +not only an showing you that a fav + + + align:start position:0% +not only an showing you that a fav +reaction that's unfavorable have a POS + + align:start position:0% +reaction that's unfavorable have a POS + + + align:start position:0% +reaction that's unfavorable have a POS +positive free energy associated with it + + align:start position:0% +positive free energy associated with it + + + align:start position:0% +positive free energy associated with it +whereas one that's favorable will have a + + align:start position:0% +whereas one that's favorable will have a + + + align:start position:0% +whereas one that's favorable will have a +negative free energy this is also sort + + align:start position:0% +negative free energy this is also sort + + + align:start position:0% +negative free energy this is also sort +of telling you why you're a you don't + + align:start position:0% +of telling you why you're a you don't + + + align:start position:0% +of telling you why you're a you don't +die when you put salad dressing on your + + align:start position:0% +die when you put salad dressing on your + + + align:start position:0% +die when you put salad dressing on your +salads because if if if acetic acid + + align:start position:0% +salads because if if if acetic acid + + + align:start position:0% +salads because if if if acetic acid +ionized as thoroughly as as sulfuric + + align:start position:0% +ionized as thoroughly as as sulfuric + + + align:start position:0% +ionized as thoroughly as as sulfuric +acid and you put an equivalent amount of + + align:start position:0% +acid and you put an equivalent amount of + + + align:start position:0% +acid and you put an equivalent amount of +sulfuric acid on your salads none of us + + align:start position:0% +sulfuric acid on your salads none of us + + + align:start position:0% +sulfuric acid on your salads none of us +would be here it's only a little tiny + + align:start position:0% +would be here it's only a little tiny + + + align:start position:0% +would be here it's only a little tiny +bit that's going and and + + align:start position:0% +bit that's going and and + + + align:start position:0% +bit that's going and and +um + + align:start position:0% +um + + + align:start position:0% +um +uh it's happening so um what this really + + align:start position:0% +uh it's happening so um what this really + + + align:start position:0% +uh it's happening so um what this really +sets up for us though is this + + align:start position:0% +sets up for us though is this + + + align:start position:0% +sets up for us though is this +fundamental problem in biology and that + + align:start position:0% +fundamental problem in biology and that + + + align:start position:0% +fundamental problem in biology and that +is that this reaction here is you can + + align:start position:0% +is that this reaction here is you can + + + align:start position:0% +is that this reaction here is you can +see why it would go this one doesn't go + + align:start position:0% +see why it would go this one doesn't go + + + align:start position:0% +see why it would go this one doesn't go +but most of the reactions that you have + + align:start position:0% +but most of the reactions that you have + + + align:start position:0% +but most of the reactions that you have +to carry out in biology demand an energy + + align:start position:0% +to carry out in biology demand an energy + + + align:start position:0% +to carry out in biology demand an energy +input because they just won't go we + + align:start position:0% +input because they just won't go we + + + align:start position:0% +input because they just won't go we +could sort of force this a little bit we + + align:start position:0% +could sort of force this a little bit we + + + align:start position:0% +could sort of force this a little bit we +could raise the concentration of of the + + align:start position:0% +could raise the concentration of of the + + + align:start position:0% +could raise the concentration of of the +of the reactants would give us a little + + align:start position:0% +of the reactants would give us a little + + + align:start position:0% +of the reactants would give us a little +bit more product but that's not a useful + + align:start position:0% +bit more product but that's not a useful + + + align:start position:0% +bit more product but that's not a useful +solution to all the things so this was a + + align:start position:0% +solution to all the things so this was a + + + align:start position:0% +solution to all the things so this was a +really fundamental problem that had to + + align:start position:0% +really fundamental problem that had to + + + align:start position:0% +really fundamental problem that had to +be solved in evolution in order for life + + align:start position:0% +be solved in evolution in order for life + + + align:start position:0% +be solved in evolution in order for life +to um ever exist and I'll give you just + + align:start position:0% +to um ever exist and I'll give you just + + + align:start position:0% +to um ever exist and I'll give you just +an + + align:start position:0% + + + + align:start position:0% + +example if we take let's consider taking + + align:start position:0% +example if we take let's consider taking + + + align:start position:0% +example if we take let's consider taking +a couple of molecules of + + align:start position:0% +a couple of molecules of + + + align:start position:0% +a couple of molecules of +glutamate which is an uh one of the Amo + + align:start position:0% +glutamate which is an uh one of the Amo + + + align:start position:0% +glutamate which is an uh one of the Amo +acids we talked about a couple of + + align:start position:0% +acids we talked about a couple of + + + align:start position:0% +acids we talked about a couple of +molecules of ammonia and making it into + + align:start position:0% +molecules of ammonia and making it into + + + align:start position:0% +molecules of ammonia and making it into +a couple of molecules + + align:start position:0% + + + + align:start position:0% + +glutamine now this is an amino acid + + align:start position:0% +glutamine now this is an amino acid + + + align:start position:0% +glutamine now this is an amino acid +needed for making proteins this is an + + align:start position:0% +needed for making proteins this is an + + + align:start position:0% +needed for making proteins this is an +amino acid needed for making proteins + + align:start position:0% +amino acid needed for making proteins + + + align:start position:0% +amino acid needed for making proteins +cell has to have both of them + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% +um + + + align:start position:0% +um +glutamate has two methylene groups and + + align:start position:0% +glutamate has two methylene groups and + + + align:start position:0% +glutamate has two methylene groups and +then a carboxy group it's one of + + align:start position:0% +then a carboxy group it's one of + + + align:start position:0% +then a carboxy group it's one of +the acidic amino acids and glutamine the + + align:start position:0% +the acidic amino acids and glutamine the + + + align:start position:0% +the acidic amino acids and glutamine the +side + + align:start position:0% + + + + align:start position:0% + +chain is now an aid the Delta + + align:start position:0% +chain is now an aid the Delta + + + align:start position:0% +chain is now an aid the Delta +G from zero associated with this + + align:start position:0% +G from zero associated with this + + + align:start position:0% +G from zero associated with this +reaction is plus 7 kilo calories per + + align:start position:0% +reaction is plus 7 kilo calories per + + + align:start position:0% +reaction is plus 7 kilo calories per +mole so it's as unfavorable almost as + + align:start position:0% +mole so it's as unfavorable almost as + + + align:start position:0% +mole so it's as unfavorable almost as +the as that one we're looking at in it's + + align:start position:0% +the as that one we're looking at in it's + + + align:start position:0% +the as that one we're looking at in it's +worse than the one we're looking at over + + align:start position:0% +worse than the one we're looking at over + + + align:start position:0% +worse than the one we're looking at over +there the reason that this uh is sort of + + align:start position:0% +there the reason that this uh is sort of + + + align:start position:0% +there the reason that this uh is sort of +pushing the thing up uphill + + align:start position:0% +pushing the thing up uphill + + + align:start position:0% +pushing the thing up uphill +energetically is that this the electrons + + align:start position:0% +energetically is that this the electrons + + + align:start position:0% +energetically is that this the electrons +here actually distribute themselves back + + align:start position:0% +here actually distribute themselves back + + + align:start position:0% +here actually distribute themselves back +and forth so you can kind of think of + + align:start position:0% +and forth so you can kind of think of + + + align:start position:0% +and forth so you can kind of think of +the molecule as going back and forth + + align:start position:0% +the molecule as going back and forth + + + align:start position:0% +the molecule as going back and forth +between these two forms and that makes + + align:start position:0% +between these two forms and that makes + + + align:start position:0% +between these two forms and that makes +it more stable and when you stick on the + + align:start position:0% +it more stable and when you stick on the + + + align:start position:0% +it more stable and when you stick on the +am group to make the the amid it can't + + align:start position:0% +am group to make the the amid it can't + + + align:start position:0% +am group to make the the amid it can't +do that and so you're actually pushing + + align:start position:0% +do that and so you're actually pushing + + + align:start position:0% +do that and so you're actually pushing +everything energetically uphill so how + + align:start position:0% +everything energetically uphill so how + + + align:start position:0% +everything energetically uphill so how +does how does cell accomplish this + + align:start position:0% +does how does cell accomplish this + + + align:start position:0% +does how does cell accomplish this +there's energy available if we consider + + align:start position:0% +there's energy available if we consider + + + align:start position:0% +there's energy available if we consider +what happens + + align:start position:0% +what happens + + + align:start position:0% +what happens +with C6 + + align:start position:0% +with C6 + + + align:start position:0% +with C6 +h206 going to two + + align:start position:0% + + + + align:start position:0% + +lactate the Delta G Prime 0 associated + + align:start position:0% +lactate the Delta G Prime 0 associated + + + align:start position:0% +lactate the Delta G Prime 0 associated +with that is minus + + align:start position:0% + + + + align:start position:0% + +50 kilo calories per mole so the cells + + align:start position:0% +50 kilo calories per mole so the cells + + + align:start position:0% +50 kilo calories per mole so the cells +get a lot of energy out of making even + + align:start position:0% +get a lot of energy out of making even + + + align:start position:0% +get a lot of energy out of making even +that simple conversion of a sugar + + align:start position:0% +that simple conversion of a sugar + + + align:start position:0% +that simple conversion of a sugar +molecule into two + + align:start position:0% +molecule into two + + + align:start position:0% +molecule into two +lactate but you have to some somehow it + + align:start position:0% +lactate but you have to some somehow it + + + align:start position:0% +lactate but you have to some somehow it +has to figure out how to use that energy + + align:start position:0% +has to figure out how to use that energy + + + align:start position:0% +has to figure out how to use that energy +in order to drive these unfavorable + + align:start position:0% +in order to drive these unfavorable + + + align:start position:0% +in order to drive these unfavorable +reactions and the solution which is + + align:start position:0% +reactions and the solution which is + + + align:start position:0% +reactions and the solution which is +really one of the the secrets uh to life + + align:start position:0% +really one of the the secrets uh to life + + + align:start position:0% +really one of the the secrets uh to life +is + + align:start position:0% +is + + + align:start position:0% +is +the is to use coupled + + align:start position:0% + + + + align:start position:0% + +reactions + + align:start position:0% +reactions + + + align:start position:0% +reactions +with a common + + align:start position:0% + + + + align:start position:0% + +intermediate and if you look outside a + + align:start position:0% +intermediate and if you look outside a + + + align:start position:0% +intermediate and if you look outside a +cell as Lavoisier did or pester did this + + align:start position:0% +cell as Lavoisier did or pester did this + + + align:start position:0% +cell as Lavoisier did or pester did this +is what you see but if you could look + + align:start position:0% +is what you see but if you could look + + + align:start position:0% +is what you see but if you could look +inside the cell and see what's happening + + align:start position:0% +inside the cell and see what's happening + + + align:start position:0% +inside the cell and see what's happening +when that conversion is being made you + + align:start position:0% +when that conversion is being made you + + + align:start position:0% +when that conversion is being made you +discover that the the full reaction + + align:start position:0% +discover that the the full reaction + + + align:start position:0% +discover that the the full reaction +looks like this it's uh the sugar + + align:start position:0% +looks like this it's uh the sugar + + + align:start position:0% +looks like this it's uh the sugar +molecule plus two molecules of ADP Plus + + align:start position:0% +molecule plus two molecules of ADP Plus + + + align:start position:0% +molecule plus two molecules of ADP Plus +two molecules of inorganic phosphate + + align:start position:0% +two molecules of inorganic phosphate + + + align:start position:0% +two molecules of inorganic phosphate +going to give two molecules of + + align:start position:0% +going to give two molecules of + + + align:start position:0% +going to give two molecules of +lactate plus two molecules of + + align:start position:0% +lactate plus two molecules of + + + align:start position:0% +lactate plus two molecules of +ATP what's ATP it's a + + align:start position:0% + + + + align:start position:0% + +ribonucleotide + + align:start position:0% +ribonucleotide + + + align:start position:0% +ribonucleotide +that's + + align:start position:0% +that's + + + align:start position:0% +that's +0p and what happens when you make a TP + + align:start position:0% +0p and what happens when you make a TP + + + align:start position:0% +0p and what happens when you make a TP +is an extra phosphate gets added on to + + align:start position:0% +is an extra phosphate gets added on to + + + align:start position:0% +is an extra phosphate gets added on to +that end of the molecule so by having + + align:start position:0% +that end of the molecule so by having + + + align:start position:0% +that end of the molecule so by having +yet another phosphate on here we've got + + align:start position:0% +yet another phosphate on here we've got + + + align:start position:0% +yet another phosphate on here we've got +a whole row of negative charges this is + + align:start position:0% +a whole row of negative charges this is + + + align:start position:0% +a whole row of negative charges this is +a a molecule in which the various parts + + align:start position:0% +a a molecule in which the various parts + + + align:start position:0% +a a molecule in which the various parts +are not happy to be together because all + + align:start position:0% +are not happy to be together because all + + + align:start position:0% +are not happy to be together because all +these negative charges would like to + + align:start position:0% +these negative charges would like to + + + align:start position:0% +these negative charges would like to +push apart so when you break the bond of + + align:start position:0% +push apart so when you break the bond of + + + align:start position:0% +push apart so when you break the bond of +ATP then energy is released so using ATP + + align:start position:0% +ATP then energy is released so using ATP + + + align:start position:0% +ATP then energy is released so using ATP +key is a way of of sort of storing + + align:start position:0% +key is a way of of sort of storing + + + align:start position:0% +key is a way of of sort of storing +chemical energy so you can use it in in + + align:start position:0% +chemical energy so you can use it in in + + + align:start position:0% +chemical energy so you can use it in in +some other kind of context and so by uh + + align:start position:0% +some other kind of context and so by uh + + + align:start position:0% +some other kind of context and so by uh +Burning It by carrying out the reaction + + align:start position:0% +Burning It by carrying out the reaction + + + align:start position:0% +Burning It by carrying out the reaction +in this way a cell is able to not only + + align:start position:0% +in this way a cell is able to not only + + + align:start position:0% +in this way a cell is able to not only +make uh sugar molecule of sugar glucose + + align:start position:0% +make uh sugar molecule of sugar glucose + + + align:start position:0% +make uh sugar molecule of sugar glucose +into to lactate it's gener able to + + align:start position:0% +into to lactate it's gener able to + + + align:start position:0% +into to lactate it's gener able to +generate um ATP along the way and the + + align:start position:0% +generate um ATP along the way and the + + + align:start position:0% +generate um ATP along the way and the +Delta + + align:start position:0% +Delta + + + align:start position:0% +Delta +G Prime Z for this reaction is - 34 kilo + + align:start position:0% + + + + align:start position:0% + +calories per mole so even though it's + + align:start position:0% +calories per mole so even though it's + + + align:start position:0% +calories per mole so even though it's +taking out some of that energy and + + align:start position:0% +taking out some of that energy and + + + align:start position:0% +taking out some of that energy and +putting it in ATP this is a reaction + + align:start position:0% +putting it in ATP this is a reaction + + + align:start position:0% +putting it in ATP this is a reaction +that goes very very efficiently then + + align:start position:0% +that goes very very efficiently then + + + align:start position:0% +that goes very very efficiently then +instead of trying to carry out just that + + align:start position:0% +instead of trying to carry out just that + + + align:start position:0% +instead of trying to carry out just that +reaction what the cell is actually doing + + align:start position:0% +reaction what the cell is actually doing + + + align:start position:0% +reaction what the cell is actually doing +is taking the + + align:start position:0% +is taking the + + + align:start position:0% +is taking the +two glutamate plus the + + align:start position:0% +two glutamate plus the + + + align:start position:0% +two glutamate plus the +two molecules of ammonia plus 2 + + align:start position:0% +two molecules of ammonia plus 2 + + + align:start position:0% +two molecules of ammonia plus 2 +ATP and then this is converting it to + + align:start position:0% +ATP and then this is converting it to + + + align:start position:0% +ATP and then this is converting it to +two + + align:start position:0% + + + + align:start position:0% + +glutamine plus two water I think I + + align:start position:0% +glutamine plus two water I think I + + + align:start position:0% +glutamine plus two water I think I +failed to put that in here + + align:start position:0% +failed to put that in here + + + align:start position:0% +failed to put that in here +so you can correct it back + + align:start position:0% +so you can correct it back + + + align:start position:0% +so you can correct it back +there plus + + align:start position:0% +there plus + + + align:start position:0% +there plus +280p plus two molecules of inorganic + + align:start position:0% +280p plus two molecules of inorganic + + + align:start position:0% +280p plus two molecules of inorganic +phosphate and so the P subi very + + align:start position:0% +phosphate and so the P subi very + + + align:start position:0% +phosphate and so the P subi very +commonly used in bi chemistry to denote + + align:start position:0% +commonly used in bi chemistry to denote + + + align:start position:0% +commonly used in bi chemistry to denote +just inorganic phosphate ion so that uh + + align:start position:0% +just inorganic phosphate ion so that uh + + + align:start position:0% +just inorganic phosphate ion so that uh +what's happened here then are these two + + align:start position:0% +what's happened here then are these two + + + align:start position:0% +what's happened here then are these two +reactions going on this reaction uh now + + align:start position:0% +reactions going on this reaction uh now + + + align:start position:0% +reactions going on this reaction uh now +because um + + align:start position:0% +because um + + + align:start position:0% +because um +ATP is involved is now uh now favorable + + align:start position:0% +ATP is involved is now uh now favorable + + + align:start position:0% +ATP is involved is now uh now favorable +and the Delta G for this reaction + + align:start position:0% +and the Delta G for this reaction + + + align:start position:0% +and the Delta G for this reaction +is + + align:start position:0% +is + + + align:start position:0% +is +m- 9 kilo calories per mole so by having + + align:start position:0% +m- 9 kilo calories per mole so by having + + + align:start position:0% +m- 9 kilo calories per mole so by having +an ATP hydrolized as part of the + + align:start position:0% +an ATP hydrolized as part of the + + + align:start position:0% +an ATP hydrolized as part of the +reaction + + align:start position:0% +reaction + + + align:start position:0% +reaction +mechanism this reaction that used to be + + align:start position:0% +mechanism this reaction that used to be + + + align:start position:0% +mechanism this reaction that used to be +unfavorable is now favorable and then + + align:start position:0% +unfavorable is now favorable and then + + + align:start position:0% +unfavorable is now favorable and then +the kind of cute thing then is if you + + align:start position:0% +the kind of cute thing then is if you + + + align:start position:0% +the kind of cute thing then is if you +sum this all up the atps and the atps + + align:start position:0% +sum this all up the atps and the atps + + + align:start position:0% +sum this all up the atps and the atps +are on both + + align:start position:0% +are on both + + + align:start position:0% +are on both +sides of the equation so they just drop + + align:start position:0% +sides of the equation so they just drop + + + align:start position:0% +sides of the equation so they just drop +drop out and what you're left + + align:start position:0% +drop out and what you're left + + + align:start position:0% +drop out and what you're left +with the C6 + + align:start position:0% +with the C6 + + + align:start position:0% +with the C6 +h126 plus the two glutamines plus two + + align:start position:0% +h126 plus the two glutamines plus two + + + align:start position:0% +h126 plus the two glutamines plus two +ammonia is going to + + align:start position:0% +ammonia is going to + + + align:start position:0% +ammonia is going to +give two + + align:start position:0% +give two + + + align:start position:0% +give two +glutamines um excuse + + align:start position:0% +glutamines um excuse + + + align:start position:0% +glutamines um excuse +me two + + align:start position:0% +me two + + + align:start position:0% +me two +lactate plus two glutamines um plus the + + align:start position:0% +lactate plus two glutamines um plus the + + + align:start position:0% +lactate plus two glutamines um plus the +two + + align:start position:0% +two + + + align:start position:0% +two +waters and + + align:start position:0% +waters and + + + align:start position:0% +waters and +the Delta G Prime Z for this is minus + + align:start position:0% +the Delta G Prime Z for this is minus + + + align:start position:0% +the Delta G Prime Z for this is minus +43 kilo calories + + align:start position:0% +43 kilo calories + + + align:start position:0% +43 kilo calories +per mole so this is not an you can think + + align:start position:0% +per mole so this is not an you can think + + + align:start position:0% +per mole so this is not an you can think +of it of the using energy in the form of + + align:start position:0% +of it of the using energy in the form of + + + align:start position:0% +of it of the using energy in the form of +ATP like there a little the way we use + + align:start position:0% +ATP like there a little the way we use + + + align:start position:0% +ATP like there a little the way we use +money in our society um I do some work + + align:start position:0% +money in our society um I do some work + + + align:start position:0% +money in our society um I do some work +at MIT I don't get given food to eat or + + align:start position:0% +at MIT I don't get given food to eat or + + + align:start position:0% +at MIT I don't get given food to eat or +TV to watch the Super Bowl instead I get + + align:start position:0% +TV to watch the Super Bowl instead I get + + + align:start position:0% +TV to watch the Super Bowl instead I get +given money then I go to the store I + + align:start position:0% +given money then I go to the store I + + + align:start position:0% +given money then I go to the store I +give them the money I end up with the + + align:start position:0% +give them the money I end up with the + + + align:start position:0% +give them the money I end up with the +food or the the stuff and if you're + + align:start position:0% +food or the the stuff and if you're + + + align:start position:0% +food or the the stuff and if you're +watching it from the outside you see me + + align:start position:0% +watching it from the outside you see me + + + align:start position:0% +watching it from the outside you see me +do work at school and then food or TV or + + align:start position:0% +do work at school and then food or TV or + + + align:start position:0% +do work at school and then food or TV or +whatever shows up at home but what's + + align:start position:0% +whatever shows up at home but what's + + + align:start position:0% +whatever shows up at home but what's +happening is the money is serving as a + + align:start position:0% +happening is the money is serving as a + + + align:start position:0% +happening is the money is serving as a +common intermediate in those + + align:start position:0% +common intermediate in those + + + align:start position:0% +common intermediate in those +transactions and that's what basically + + align:start position:0% +transactions and that's what basically + + + align:start position:0% +transactions and that's what basically +ATP is in a Cell It's energy money and + + align:start position:0% +ATP is in a Cell It's energy money and + + + align:start position:0% +ATP is in a Cell It's energy money and +in making ATP the uh cell has to take + + align:start position:0% +in making ATP the uh cell has to take + + + align:start position:0% +in making ATP the uh cell has to take +this ribos with an adenine on it I think + + align:start position:0% +this ribos with an adenine on it I think + + + align:start position:0% +this ribos with an adenine on it I think +I didn't put the adenine on here + + align:start position:0% + + + + align:start position:0% + +realize uh and um + + align:start position:0% +realize uh and um + + + align:start position:0% +realize uh and um +the Adine sitting on the ribos now there + + align:start position:0% +the Adine sitting on the ribos now there + + + align:start position:0% +the Adine sitting on the ribos now there +there's two phosphates both of which + + align:start position:0% +there's two phosphates both of which + + + align:start position:0% +there's two phosphates both of which +have a negative charge on them and to + + align:start position:0% +have a negative charge on them and to + + + align:start position:0% +have a negative charge on them and to +create that third Bond it has to push it + + align:start position:0% +create that third Bond it has to push it + + + align:start position:0% +create that third Bond it has to push it +together so this very sort of unstable + + align:start position:0% +together so this very sort of unstable + + + align:start position:0% +together so this very sort of unstable +intrinsically unstable molecule when you + + align:start position:0% +intrinsically unstable molecule when you + + + align:start position:0% +intrinsically unstable molecule when you +break the bond it'll give you energy + + align:start position:0% +break the bond it'll give you energy + + + align:start position:0% +break the bond it'll give you energy +back and that's one of the the really uh + + align:start position:0% +back and that's one of the the really uh + + + align:start position:0% +back and that's one of the the really uh +amazing secrets to life and that's the + + align:start position:0% +amazing secrets to life and that's the + + + align:start position:0% +amazing secrets to life and that's the +the underlying principle of why it is + + align:start position:0% +the underlying principle of why it is + + + align:start position:0% +the underlying principle of why it is +that life can go can go forward now the + + align:start position:0% +that life can go can go forward now the + + + align:start position:0% +that life can go can go forward now the +second issue that we need to quick + + align:start position:0% +second issue that we need to quick + + + align:start position:0% +second issue that we need to quick +address here + + align:start position:0% + + + + align:start position:0% + +is oops where did maybe it's + + align:start position:0% + + + + align:start position:0% + +here + + align:start position:0% +here + + + align:start position:0% +here +is not only can a reaction go which is + + align:start position:0% +is not only can a reaction go which is + + + align:start position:0% +is not only can a reaction go which is +what thermodynamics tells us but how + + align:start position:0% +what thermodynamics tells us but how + + + align:start position:0% +what thermodynamics tells us but how +fast can it go and this epitomizes the + + align:start position:0% +fast can it go and this epitomizes the + + + align:start position:0% +fast can it go and this epitomizes the +problem that all chemical reactions face + + align:start position:0% +problem that all chemical reactions face + + + align:start position:0% +problem that all chemical reactions face +because literally every chemical + + align:start position:0% +because literally every chemical + + + align:start position:0% +because literally every chemical +reaction that you carry out involves + + align:start position:0% +reaction that you carry out involves + + + align:start position:0% +reaction that you carry out involves +bringing a couple of entities together + + align:start position:0% +bringing a couple of entities together + + + align:start position:0% +bringing a couple of entities together +and as they get closer and closer and + + align:start position:0% +and as they get closer and closer and + + + align:start position:0% +and as they get closer and closer and +closer it they don't want to be there so + + align:start position:0% +closer it they don't want to be there so + + + align:start position:0% +closer it they don't want to be there so +you have to sort of push them together + + align:start position:0% +you have to sort of push them together + + + align:start position:0% +you have to sort of push them together +in some kind of way or make sure they + + align:start position:0% +in some kind of way or make sure they + + + align:start position:0% +in some kind of way or make sure they +have enough energy to get together and + + align:start position:0% +have enough energy to get together and + + + align:start position:0% +have enough energy to get together and +that's what we see represented here and + + align:start position:0% +that's what we see represented here and + + + align:start position:0% +that's what we see represented here and +that's a special term called the + + align:start position:0% +that's a special term called the + + + align:start position:0% +that's a special term called the +activation + + align:start position:0% + + + + align:start position:0% + +energy it's given the term Delta G with + + align:start position:0% +energy it's given the term Delta G with + + + align:start position:0% +energy it's given the term Delta G with +a with a double dagger and that is what + + align:start position:0% +a with a double dagger and that is what + + + align:start position:0% +a with a double dagger and that is what +um + + align:start position:0% +um + + + align:start position:0% +um +it's the the size of that activation + + align:start position:0% +it's the the size of that activation + + + align:start position:0% +it's the the size of that activation +energy that limits how fast chemical + + align:start position:0% +energy that limits how fast chemical + + + align:start position:0% +energy that limits how fast chemical +reactions can go so the solution you use + + align:start position:0% +reactions can go so the solution you use + + + align:start position:0% +reactions can go so the solution you use +in chemistry most of you know it's a cat + + align:start position:0% +in chemistry most of you know it's a cat + + + align:start position:0% +in chemistry most of you know it's a cat +you use a catalyst the Catalyst doesn't + + align:start position:0% +you use a catalyst the Catalyst doesn't + + + align:start position:0% +you use a catalyst the Catalyst doesn't +change the outcome of the reaction it + + align:start position:0% +change the outcome of the reaction it + + + align:start position:0% +change the outcome of the reaction it +just changes how fast you get there so + + align:start position:0% +just changes how fast you get there so + + + align:start position:0% +just changes how fast you get there so +there are many reactions you heard about + + align:start position:0% +there are many reactions you heard about + + + align:start position:0% +there are many reactions you heard about +in chemistry just stick the thing at + + align:start position:0% +in chemistry just stick the thing at + + + align:start position:0% +in chemistry just stick the thing at +500° Centigrade put in a piece of + + align:start position:0% +500° Centigrade put in a piece of + + + align:start position:0% +500° Centigrade put in a piece of +platinum and some Platinum uh and now + + align:start position:0% +platinum and some Platinum uh and now + + + align:start position:0% +platinum and some Platinum uh and now +the reaction will go a whole lot faster + + align:start position:0% +the reaction will go a whole lot faster + + + align:start position:0% +the reaction will go a whole lot faster +by heating it up you the molecules have + + align:start position:0% +by heating it up you the molecules have + + + align:start position:0% +by heating it up you the molecules have +more energy so they have more energy + + align:start position:0% +more energy so they have more energy + + + align:start position:0% +more energy so they have more energy +they can get closer together just from + + align:start position:0% +they can get closer together just from + + + align:start position:0% +they can get closer together just from +that and then what the the Platinum + + align:start position:0% +that and then what the the Platinum + + + align:start position:0% +that and then what the the Platinum +surface would do would allow the + + align:start position:0% +surface would do would allow the + + + align:start position:0% +surface would do would allow the +molecules to both stick and it would + + align:start position:0% +molecules to both stick and it would + + + align:start position:0% +molecules to both stick and it would +bring them in proximity and also help + + align:start position:0% +bring them in proximity and also help + + + align:start position:0% +bring them in proximity and also help +them them come together we can't raise + + align:start position:0% +them them come together we can't raise + + + align:start position:0% +them them come together we can't raise +the temperature in a biological system + + align:start position:0% +the temperature in a biological system + + + align:start position:0% +the temperature in a biological system +but still you have to overcome this but + + align:start position:0% +but still you have to overcome this but + + + align:start position:0% +but still you have to overcome this but +the principle then what you have to do + + align:start position:0% +the principle then what you have to do + + + align:start position:0% +the principle then what you have to do +when you're carrying out a Catal what + + align:start position:0% +when you're carrying out a Catal what + + + align:start position:0% +when you're carrying out a Catal what +any Catalyst has would do is that it + + align:start position:0% +any Catalyst has would do is that it + + + align:start position:0% +any Catalyst has would do is that it +lowers + + align:start position:0% +lowers + + + align:start position:0% +lowers +this this activation + + align:start position:0% + + + + align:start position:0% + +energy and if you lower the activation + + align:start position:0% +energy and if you lower the activation + + + align:start position:0% +energy and if you lower the activation +energy then enough of the molecules just + + align:start position:0% +energy then enough of the molecules just + + + align:start position:0% +energy then enough of the molecules just +at whatever condition they're in will + + align:start position:0% +at whatever condition they're in will + + + align:start position:0% +at whatever condition they're in will +have enough energy to be able to go it + + align:start position:0% +have enough energy to be able to go it + + + align:start position:0% +have enough energy to be able to go it +won't change the size of the drop it + + align:start position:0% +won't change the size of the drop it + + + align:start position:0% +won't change the size of the drop it +just changes how fast you reach the that + + align:start position:0% +just changes how fast you reach the that + + + align:start position:0% +just changes how fast you reach the that +final equilibrium and there are two + + align:start position:0% +final equilibrium and there are two + + + align:start position:0% +final equilibrium and there are two +forms of U + + align:start position:0% +forms of U + + + align:start position:0% +forms of U +biological two molecules that are + + align:start position:0% +biological two molecules that are + + + align:start position:0% +biological two molecules that are +biological + + align:start position:0% + + + + align:start position:0% + +catalysts one of the molecules you know + + align:start position:0% +catalysts one of the molecules you know + + + align:start position:0% +catalysts one of the molecules you know +is as + + align:start position:0% + + + + align:start position:0% + +enzymes enzymes are made of a protein we + + align:start position:0% +enzymes enzymes are made of a protein we + + + align:start position:0% +enzymes enzymes are made of a protein we +spent a bunch of time um + + align:start position:0% +spent a bunch of time um + + + align:start position:0% +spent a bunch of time um +working at that one of the things I + + align:start position:0% +working at that one of the things I + + + align:start position:0% +working at that one of the things I +showed you the very first day uh this is + + align:start position:0% +showed you the very first day uh this is + + + align:start position:0% +showed you the very first day uh this is +a thing made by the anthrax bacterium + + align:start position:0% +a thing made by the anthrax bacterium + + + align:start position:0% +a thing made by the anthrax bacterium +Anthrax lethal Factor what it actually + + align:start position:0% +Anthrax lethal Factor what it actually + + + align:start position:0% +Anthrax lethal Factor what it actually +is it's a protein and it's an enzyme + + align:start position:0% +is it's a protein and it's an enzyme + + + align:start position:0% +is it's a protein and it's an enzyme +that's able to catalyze the cleavage of + + align:start position:0% +that's able to catalyze the cleavage of + + + align:start position:0% +that's able to catalyze the cleavage of +certain uh peptide bonds in proteins in + + align:start position:0% +certain uh peptide bonds in proteins in + + + align:start position:0% +certain uh peptide bonds in proteins in +our body and it particular it goes after + + align:start position:0% +our body and it particular it goes after + + + align:start position:0% +our body and it particular it goes after +molecules that are involved in in + + align:start position:0% +molecules that are involved in in + + + align:start position:0% +molecules that are involved in in +signaling processes inside of cells and + + align:start position:0% +signaling processes inside of cells and + + + align:start position:0% +signaling processes inside of cells and +we don't have those then we die more + + align:start position:0% +we don't have those then we die more + + + align:start position:0% +we don't have those then we die more +recently it was discovered that + + align:start position:0% +recently it was discovered that + + + align:start position:0% +recently it was discovered that +RNA can be a catalyst and these are + + align:start position:0% +RNA can be a catalyst and these are + + + align:start position:0% +RNA can be a catalyst and these are +called + + align:start position:0% + + + + align:start position:0% + +um if you have an RNA that's a catalyst + + align:start position:0% +um if you have an RNA that's a catalyst + + + align:start position:0% +um if you have an RNA that's a catalyst +it's it's called a + + align:start position:0% + + + + align:start position:0% + +ribosome and these seem pretty exotic + + align:start position:0% +ribosome and these seem pretty exotic + + + align:start position:0% +ribosome and these seem pretty exotic +for a little while when they first + + align:start position:0% +for a little while when they first + + + align:start position:0% +for a little while when they first +discovered the idea that a piece of RNA + + align:start position:0% +discovered the idea that a piece of RNA + + + align:start position:0% +discovered the idea that a piece of RNA +could serve as a catalyst in a + + align:start position:0% +could serve as a catalyst in a + + + align:start position:0% +could serve as a catalyst in a +biological system but uh it eventually + + align:start position:0% +biological system but uh it eventually + + + align:start position:0% +biological system but uh it eventually +turned out that the ribosome which we'll + + align:start position:0% +turned out that the ribosome which we'll + + + align:start position:0% +turned out that the ribosome which we'll +talk about in some detail which is a is + + align:start position:0% +talk about in some detail which is a is + + + align:start position:0% +talk about in some detail which is a is +the protein synthesizing Machinery that + + align:start position:0% +the protein synthesizing Machinery that + + + align:start position:0% +the protein synthesizing Machinery that +creates those peptide bonds between each + + align:start position:0% +creates those peptide bonds between each + + + align:start position:0% +creates those peptide bonds between each +of the amino acids to make the proteins + + align:start position:0% +of the amino acids to make the proteins + + + align:start position:0% +of the amino acids to make the proteins +it's a big conglomeration of RNA shown + + align:start position:0% +it's a big conglomeration of RNA shown + + + align:start position:0% +it's a big conglomeration of RNA shown +in Gray and a bunch of proteins + + align:start position:0% +in Gray and a bunch of proteins + + + align:start position:0% +in Gray and a bunch of proteins +different proteins that are shown in + + align:start position:0% +different proteins that are shown in + + + align:start position:0% +different proteins that are shown in +yellow but the actual formation of the + + align:start position:0% +yellow but the actual formation of the + + + align:start position:0% +yellow but the actual formation of the +peptide bond the thing that makes all + + align:start position:0% +peptide bond the thing that makes all + + + align:start position:0% +peptide bond the thing that makes all +proteins is actually catalyzed by a + + align:start position:0% +proteins is actually catalyzed by a + + + align:start position:0% +proteins is actually catalyzed by a +piece of RNA and so the ribosome is + + align:start position:0% +piece of RNA and so the ribosome is + + + align:start position:0% +piece of RNA and so the ribosome is +actually a ribozyme and it's ironic that + + align:start position:0% +actually a ribozyme and it's ironic that + + + align:start position:0% +actually a ribozyme and it's ironic that +that sense that a piece of RNA is + + align:start position:0% +that sense that a piece of RNA is + + + align:start position:0% +that sense that a piece of RNA is +catalyzing the bond that makes proteins + + align:start position:0% +catalyzing the bond that makes proteins + + + align:start position:0% +catalyzing the bond that makes proteins +possible so we'll finish this up and get + + align:start position:0% +possible so we'll finish this up and get + + + align:start position:0% +possible so we'll finish this up and get +in then to uh glycolysis which is the + + align:start position:0% +in then to uh glycolysis which is the + + + align:start position:0% +in then to uh glycolysis which is the +most evolutionary ancient of these uh + + align:start position:0% +most evolutionary ancient of these uh + + + align:start position:0% +most evolutionary ancient of these uh +energy producing systems on on Monday + + align:start position:0% + + + + align:start position:0% + +okay \ No newline at end of file diff --git a/7xJJU5HDCVE.txt b/7xJJU5HDCVE.txt new file mode 100644 index 0000000000000000000000000000000000000000..adf664f4bf691c908552a8e9d886b854ba7d481e --- /dev/null +++ b/7xJJU5HDCVE.txt @@ -0,0 +1,1293 @@ +The following +content is provided + +under a Creative +Commons License. + +Your support will help MIT +OpenCourseWare continue + +to offer high quality +educational resources for free. + +To make a donation or +view additional materials + +from hundreds of MIT courses, +visit MIT OpenCourseWare + +at ocw.mit.edu. + +SPEAKER 1: Welcome to +this Vensim tutorial. + +As a group of students engaged +in the system dynamics seminar + +at MIT Sloan, we +will present how + +to estimate model parameters +and the confidence interval + +in a dynamic model using Maximum +Likelihood Estimation, MLE, + +Likelihood Ratio, LR method. + +First, the basics of MLE +are described, as well as + +the advantages and +underlying assumptions. + +Next, the different methods +available for finding + +confidence intervals of +the estimated parameters + +are discussed. + +Then, a step-by-step guide +to a parameter estimation + +using MLE-- an assessment +of the uncertainty + +around parameter estimates using +Univariant Likelihood Ratio + +Method in Vensim-- is provided. + +This video is presented to you +by William, George, Sergey, + +and Jim under the guidance of +Professor Hazhir Rahmandad. + +The literature, Struben, +Sterman, and Keith, + +highlight that estimating model +parameters and the uncertainty + +of these parameters are central +to good dynamic modeling + +practice. + +Models must be grounded +in data if modelers + +are to provide reliable +advice to policymakers. + +Ideally, one should +estimate model parameters + +using data that are independent +of the model behavior. + +Often, however, such +direct estimation + +from independent +data is not possible. + +In practice, modelers +must frequently + +estimate at least +some model parameters + +using historical data itself, +finding the set of parameters + +that minimize the difference +between the historical and + +simulated time series. + +Only then can estimations +of model parameters + +and uncertainties +of these estimations + +serve to test model +hypotheses and quantify + +important uncertainties, which +are crucial for decision-making + +based on modeling outcome. + +Therefore, when modeling +a system in Vensim, + +if the purpose of this model +involves numerical testing + +or projection, robust +statistical parameter + +estimation is necessary. + +Confidence intervals also +serve as an important tool + +for decision-making based +on modeling outcomes. + +Various approaches are +available to estimate parameters + +in confidence intervals in +dynamic model, including, + +for estimation, the +generalized methods of moments + +in maximum likelihood, and +for confidence intervals, + +likelihood-based methods +and bootstrapping. + +Maximum Likelihood Estimation +is becoming increasingly + +important for +nonlinear models when + +estimating nonlinear +parameters that + +consist of non-normal, +autocorrelated errors, + +and heteroscedasticity. + +It is simpler to understand +the construct, yet + +at the same time, +requires relatively little + +computational power. + +MLE is best suitable for +using historical data + +to generate parameter +estimation and confidence + +intervals as long as +errors of estimation + +are independent and +identically distributed. + +When using MLE in +complex systems + +where these assumptions +are violated, + +and/or the analytical +likelihood function + +might be difficult +to find, one should + +use more advanced methods. + +This tutorial will not +address these cases. + +As the demonstration will +show, the average laptop + +in use in 2014 is capable +of running the analysis + +in a few minutes or less. + +This tutorial is based on the +following four references-- + +"Bootstrapping for confidence +interval estimation + +and hypothesis testing for +parameters of system dynamics + +models" by Dogan, "A behavioral +approach to feedback loop + +dominance analysis" by +Ford, "Modeling Managerial + +Behavior," also known as +"The Beer Game" by Sterman, + +and a soon-to-be published text +by Struben, Sterman, and Keith, + +"Parameter and Confidence +Interval Estimation in Dynamic + +Models-- Maximum Likelihood +and Bootstrapping Methods." + +More background and explanation +on the theory of MLE + +can be found in these works. + +This tutorial will focus on the +application of MLE in Vensim. + +The literature, Struben, +Sterman, and Keith, + +stresses that +modelers must not only + +estimate parameter values, +but also the uncertainty + +in the estimates so they +and others can determine + +how much confidence to +place in the estimates + +and select appropriate ranges +for sensitivity analysis + +in order to assess the +robustness of the conclusions. + +Estimating confidence +intervals can + +be thought of as +finding the shape + +of the inverted bowl, Figure 2. + +If for a given data set, +the likelihood function + +for a set of parameters +falls off very steeply + +for even small departures +from the best estimate, + +then one can have confidence +that the true parameters + +are close to the +estimated value. + +As always, assuming the +model is correctly specified, + +another maintained +hypothesis are satisfied. + +If the likelihood +falls off only slowly, + +other values of the parameters +are nearly as likely + +as the best estimates and one +cannot have much confidence + +in the estimated values. + +MLE methods provides +two major approaches + +to constructing confidence +intervals or confidence + +regions. + +The first is the +asymptotic method, AM, + +which assumes that the +likelihood function can + +be approximated by a parabola +around the estimated parameter. + +An assumption that is valid +for a very large sample. + +The second is the +likelihood ratio, LR method. + +The LR is the ratio of +the likelihood for a given + +set of parameter values to the +likelihood for the MLE values. + +The LR method involves searching +the actual likelihood surface + +to find values of the +likelihood function + +that yield a particular +value for the LR. + +That value is derived for +the probability distribution + +of the LR and the +confidence level + +desired, such as 95% chance that +the true parameter value lies + +within the confidence interval. + +This tutorial will use the +Univariate Likelihood Ratio + +for determining the MLE +competence interval in Vensim. + +The estimated parameter +and competence interval + +mean that for a specific +percentage of probability-- + +usually 95 or 99% that +the real parameter falls + +within the confidence interval +with the designated percent + +possibility. + +This is consistent with +general applications + +of statistics and probability. + +The LR our method of +confidence interval + +estimation compared to the +likelihood for the estimated + +parameter, theta hat, with +that of an alternative set, + +theta star. + +The likelihood ratio is +determined in equation one + +as R equals L theta hat +divided by L theta star. + +Asymptotically, the +likelihood ratio + +falls at chi square +distribution, equation two. + +This is valuable, because the +univariate method requires + +no new optimizations once +the MLE has been found. + +The critical parameter +value for all parameters + +is then simply using +equation three. + +A disadvantage of univariate +confidence interval estimates, + +however, is that the parameter +space is not fully explored. + +Hence, the effect of interaction +between the parameters on LL + +is ignored, + +The tutorial now switches +to a real simulation + +using Vensim 6.1. + +It will show how the +theory just described + +can be applied to estimating +parameters of decision-making + +in the Beer Distribution Game. + +SPEAKER 2: Hello. + +This tutorial is now going +to explore analytics, + +by estimating the parameters +for a well-analyzed model + +of decision-making used in +the Beer Distribution Game. + +The model is described in the +paper, "Modeling Managerial + +Behavior-- Misperception +of Feedback in a Dynamic + +Decision-Making Experiment" by +Professor Sterman from 1989. + +Participants in the beer +game choose how much beer + +to order each period in +a simulated supply chain. + +The challenge is to estimate +the parameters of a proposed + +decision rule for +participant orders. + +The screen shows +the simple model + +of beer game decision-making. + +The ordering decision rule +proposed by Professor Sterman + +is the following. + +The orders placed every week +are given by the maximum of zero + +and the sum of expected +customer orders-- the orders + +that participants +expect to receive + +next period from their +immediate customer and inventory + +discrepancy. + +The inventory discrepancy +is the difference + +between total desired +inventory and some + +of actual on-hand +inventory and supply + +line of on-order inventory. + +There are four +parameters that are + +used in the model-- [INAUDIBLE], +the weight on incoming orders + +in demand forecasting, +S prime, the desired + +on-hand and on-order +inventory, the fraction + +of the gap between desired and +actual on-hand and on-order + +inventory ordered each +week, and the fraction + +of the supply line the +subject accounts for. + +As modelers, we don't +know what the parameters + +of the actual game are. + +But we have the data for actual +orders placed by participants. + +And this data is read +from the Excel spreadsheet + +into the variable, +actual orders. + +Let's start from +some guesstimates + +and assign the following values. + +[INAUDIBLE], fraction +of discrepancy + +between desired and +actual inventory, + +and supply line fraction +are all equal to 0.5. + +S prime, the total desired +inventory, is 20 cases of beer. + +With these parameters, the +model runs and generates + +some alias of the +order placed, which + +can be seem on this graph. + +Let's compare them +against the actual orders + +observed in the beer game. + +We can see that although +the trend is generally + +correct at the high level, the +shape is totally different. + +This necessitates the question, +how can we effectively measure + +the fit of the data? + +The typical way is to calculate +the sum of squared errors, + +which are differences between +simulated and actual data + +points. + +Square, to make +sure negative values + +don't reduce the total sum. + +The basic statistics +of any variable + +can be found by +using statistics to + +from either object +output or bench tool. + +For this tutorial, I +have already defined it. + +And in this case, we can see +[INAUDIBLE] of sum of squares + +of residuals is 1700, +with a mean of about 35. + +This is pretty far +from a good fit, + +and we can confirm +it officially. + +Now let's see how to +run the optimization + +to find the parameters that +will bring the values of orders + +placed as close to the +actual orders as possible. + +The optimization +control panel is + +invoked by using optimized +tool on the toolbar. + +When you first open, you have +to specify the file name here. + +Also, it is necessary to specify +what type of optimization + +you're going to do. + +There are two types +that can be used. + +They differ in the way they +interpret and calculate + +the payoff value. + +A payoff is a single number +that summarize the simulation. + +In the case of +the simulation, it + +will be a measure +of fit, which can + +be a sum of squared +errors between the actual + +and the simulated +values, or it can + +be a true electrical function. + +If you are only interested +in finding the best + +fit without worrying about +confidence intervals, + +you can use the +calibration mode. + +For calibration, it is +not necessary to define + +the payoff functional mode. + +Instead, choose the model +variable and the data variable + +with which the model +variable will be compared. + +In Vensim, then +at each time step, + +the difference between the +data and the model variable + +is multiplied by the +weight specified. + +And this product +is then squared. + +This number, which +is always positive, + +is then subtracted +from the payoff, + +so that the payoff +is always negative. + +Maximizing the +payoff means getting + +it to be as close +to zero as possible. + +However, this is not a true +log-likelihood function, + +so the results cannot be used to +find the confidence intervals, + +which we need. + +Therefore, we're going +to use the policy mode. + +For policy mode, +the payoff function + +must be specified explicitly. + +At each time step, the +value of the variable + +or presenting a payoff function +is multiplied by the weight. + +Then it is multiplied by time +step and added to the payoff. + +The optimizer is designed +to maximize the payoff. + +So variables, for +which more is better, + +should be given +positive weights, + +and those, for which +less is better, + +should be given +negative weights. + +Here, [INAUDIBLE] are specified +in the sum of squared errors. + +Residuals are calculated as +the difference between orders + +placed and actual orders +at each time step. + +This squared value +is then accumulated + +in the stock sum +of residual square. + +The tricky part is the variable, +total sum of residual square. + +Please note that because +Vensim, in the policy mode, + +multiplies the values +of the payoff function + +by the time step, +the payoff value + +is the weighted combination +of the different payoff + +elements integrated +over the simulation. + +This is not what +we're looking for. + +We are interested in the final +value of a variable instead + +of the integrated value, because +the final value is exactly + +the total sum of squared +errors the way we defined it. + +Here's an example to +illustrate the concept. + +In this line is a +stock variable level. + +It can be seen that, if we +just use the stock of sum + +of residual squared in +the payoff function, + +we get the value, which is equal +to the area under the curve, + +instead of the final +value that we need. + +[INAUDIBLE] look at +only the final value. + +In a model, it is necessary +to introduce new variable + +for the payoff function and +use the following equation that + +makes its value to be +zero at each time step, + +except for the final step. + +Add the current value of the +residual squared to the stock + +level to account for the value +of the current time step. + +This effectually ignores +all the intermediate values + +and looks only at +the final value. + +So far, this is +nothing different + +from what Vensim was doing +in the calibration mode. + +We simply replicated what it +would be doing automatically. + +In order to get the true +likelihood function-- assuming + +normal distribution +of errors-- we + +need to divide the +sum of squared errors + +by two variances. + +This is what you can see in the +true low likelihood function + +variable. + +So far, in this +demonstration, we + +don't know what the +standard deviation of errors + +is going to be, because we +haven't optimized anything yet, + +so we're going to leave +this variable as 1. + +We are going to change +it to the actual value + +of the standard deviation of +errors later by the confidence + +interval. + +Now let's change the +run name and go back + +to Optimization Setup. + +And let's use our log-likelihood +function as the payoff element. + +Because this is +policy mode, we don't + +need to specify anything +in Compare To field. + +For the weight, because +this is policy mode, + +it is necessary to +assign a negative value. + +This tells Vensim +that we're looking + +to minimize the payoff function. + +If there are multiple +payoff functions, + +the weight value would +have been important. + +For one function, +it doesn't matter. + +But we don't want +to change the values + +of the log-likelihood function +to calculate true confidence + +internal values. + +Therefore, the log-likelihood +function will not be scaled, + +and the weight is +going to be minus 1. + +Next screen, the +Optimization Control Panel, + +we have to specify +the file name again. + +Then, make sure to +use multiple starts. + +This means the +analysis is less likely + +going to be stuck +at a local optimum + +if the surface is not complete. + +If multiple starts is +random, starting points + +for any optimizations are +picked randomly and uniformly + +over the range of +each parameter. + +Next field, optimizer, tells +Vensim to use probable method + +to find local minimum +function at each start. + +Technically, you could +ignore this parameter + +and just rely on +random starts to find + +the values of a payoff function. + +However, using multiple +starts together + +with optimization +of each time step + +produces better and +faster convergence. + +The other values are left +at the default levels. + +You can read more about these +parameter in Vensim help, + +but generally, they +control the optimization + +and are important for +complicated models + +where simulation +time is significant. + +Let's add now the parameters +that Vensim will vary in order + +to minimize the payoff function. + +Next, make sure Payoff Report +is selected and hit Finish. + +For random or other random +values of multiple start, + +the optimizer will +never stop unless you + +click on the Stop +button to interrupt it. + +If you don't choose +multiple starts, + +the next few steps +are not necessary + +as Vensim would be able +to complete optimization + +and sensitivity analysis, +which is performed + +in the final step +of optimization. + +However, as I mentioned, +the optimization + +can be stuck at a +local optimum, thus + +producing some optimal results. + +So it is recommended that you +use multiple starts unless you + +know the shape of +the payoff function + +and are sure that local optimum +is equal to the global optimum. + +So having chosen +random multiple starts, + +the question is, when to +stop the optimization. + +This requires some +experiments and depends + +on the shape of your +payoff function. + +In this case, the +values of the payoff + +have been changing quite +fast in the beginning + +and are now at the same +level for quite some time. + +So it's a good time to attempt +to interrupt the optimization + +and see if you like the results. + +As you can see, the shape +of the orders placed + +is much closer to the +actual order values. + +The statistics shows +a much better fit, + +with the total sum of squared +error significantly lower + +at the level of just 279, +with a mean of 5.813. + +The values of the rest of +the optimized parameter + +can be looked up in the +file with the same name + +as the run name and +the extension out. + +We can open this file from +Vensim using the Edit File + +command from File menu. + +So far, we only know the +optimal values, but not + +the confidence intervals. + +We need now to tell Vensim to +use the optimal values found + +and calculate the confidence +intervals around them. + +We are going to do it by using +the output of the optimization + +and changing +optimization parameters. + +To do this, first, we have to +modify the optimization control + +parameters and turn +of multiple starts, + +and optimize them, and save +it as the optimization control + +type file, BOC. + +Also, we need to change the +value of standard deviation + +to the actual value +to make sure we're + +looking at the true values of +the log-likelihood function. + +This value can be found in the +statistics [INAUDIBLE] again. + +We use it to change the +variable in the model. + +Open the Optimization +Control Panel again, + +and leave the payoff +function as it is. + +But on the Optimization +Control Screen, + +open the file that +was just created + +and check that multiple starts +and optimizer are turned off. + +In addition, specify [INAUDIBLE] +by choosing payoff value + +and entering the value by +which Vensim will change + +the optimal likelihood function +in order to find the constants + +controls. + +Because for likelihood +ratio method, + +the likelihood ratio +is approximated + +by the chi-square +distribution, it + +is necessary to find the value +of chi-square distribution + +[INAUDIBLE] for 95th percentile +for one degree of freedom, + +because we are doing +the univariate analysis. + +A disadvantage of univariate +confidence interval estimation + +is that the parameter space +is not fully explored. + +Hence, the effect of +interaction between parameters + +and log-likelihood +function is ignored. + +The value of chi-squared, +in this case, + +is approximately +3.84146, which we're + +going to use in the +sensitivity field. + +Now, the [INAUDIBLE] button. + +And as you see, +this time, we don't + +have to wait as Vensim +doesn't do any optimization. + +The results, +allocated in the file + +that has the name of +the run-- and the word + +sensitive with +the extension tab. + +Let's open this file and +see our estimated parameters + +and the confidence intervals. + +Since we are using too much +more likelihood function, + +the confidence bounds are +not necessarily symmetric. + +This is a very simple tutorial. + +I hope you are now more familiar +with [INAUDIBLE] for estimating + +parameters and confidence +intervals for your models. + +Thank you. + +SPEAKER 3: A summary of the +seven key steps involved + +in determining the MLE in Vensim +is contained on the slide. + +It can be printed and +serve as a useful reference + +and check for those +wishing to use the method. + +MLE has its advantages +and disadvantages + +in estimating parameters and +their confidence intervals + +when performing +dynamic modeling. + +In conclusion, +when the condition + +of errors being independent +and identically distributed + +are met, then MLE is a simple +and straightforward method + +for estimating +parameters in determining + +their statistical fit in system +dynamics models developed + +in Vensim. \ No newline at end of file diff --git a/7y67IP6XTPc.txt b/7y67IP6XTPc.txt new file mode 100644 index 0000000000000000000000000000000000000000..2e08243896f3311eddcf381060c5fe3ea3972628 --- /dev/null +++ b/7y67IP6XTPc.txt @@ -0,0 +1,4538 @@ +The following content is +provided under a Creative + +Commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high quality educational +resources for free. + +To make a donation or view +additional materials from + +hundreds of MIT courses, visit +MIT OpenCourseWare at + +ocw.mit.edu. + +PROFESSOR: Hi everyone. + +So I am Esther Duflo. + +I am the other person who +teaches this class. + +You had Abhijit for +the first class. + +I am going to start by doing +a bit of housekeeping. + +Keeping in mind that maybe +some people are going to + +arrive, so it is your +responsibility to inform + +everybody else of what +I said today. + +I got some requests of +clarifying what was the + +requirements for this +class, so I'll just + +go through it once. + +So we are going to post +essay topics. + +For 10 topics. + +And we are going to give +three or four choices. + +You can also make +your own essays. + +Whatever it is. + +You do have a chance to +write up to 10 essays. + +But you don't need to +write that many. + +You are going to be graded +out of the best five. + +So you can write any between +one and ten. + +And if you have one you're not +going to have a very high + +grade but-- + +Any between five and ten and +then we'll just take + +the best five, OK? + +I think the syllabus said seven +and Abhijit said five, + +so I went for the +easier thing. + +So that's one thing. + +The syllabus also said that we +might not grade all of them + +but, actually, we are going +to grade all of them. + +So I would suggest that you do +the first one so that you get + +used to it. + +Traditionally, it has been the +case that when students can + +decide how to arrange their +deadlines, they think that + +it's efficient to set all the + +deadlines late in the semester. + +I can tell you by experience +that it's actually exposed not + +to be such a good idea. + +So if I were you, I would +arrange things to do as many + +of them early as possible +so you don't get + +panicked by the end. + +So that's one. + +The other component of the +requirement for this class is + +to do the readings. + +And so to be prepared to +discuss in the class. + +One way in which we're going +to ensure that you're doing + +the reading is a very, +very short pop-quizes + +every once in awhile. + +It also means you have +to come to class. + +It's not a class that's +very difficult. + +But one thing that it requires +is that you actually come. + +And so we're going to have those +at any random times. + +Very simple. + +2, 3, 4 questions just to check +that you've actually + +read the thing. + +And today the questions for the +first topic were already + +posted on Stellar. + +So you already have access to +them as well as the deadline + +for the first thing. + +And that's it. + +Other than that, I think I gave +a version of this spiel + +in 14.74 yesterday. + +There are two development +classes. + +If you're wondering which one +you should be in, this one is + +going to be more based +on the readings and + +discussion and lectures. + +And the other one's going to go +more in the detail of the + +techniques of papers and +solving the models and + +replicating empirical +papers, et cetera. + +So this one's a better +introduction and the other one + +is better if you already have a +fair amount of economics and + +econometrics. + +So that's the trade off. + +Other than that, obviously, the +themes that are going to + +be covered are going to +be pretty similar. + +So my sense is, probably, that +you don't want to take both at + +the same time. + +Although you could think of +taking them both in sequence. + +Then you would do 73 +first, 74 second. + +I don't recognize any 74 +students, but you shouldn't + +want to take 74 and then 73. + +That would be a bit boring. + +So you're welcome to shop a +little bit for some time and + +then decide what's +more appropriate. + +You're welcome to take both but +I would have warned you + +that there will be some overlap +between the two. + +That's it for housekeeping so if +you have questions, that's + +a good time. + +I'm happy to answer questions by +email also but chances are + +that if you have a question on +the logistics, a lot of people + +share it as well. + +Any questions? + +No. + +The class is being recorded, +that's for OpenCourseWare. + +But don't worry about saying +anything embarrassing. + +That would be edited out. + +I'm the only one-- + +and Abhijit-- + +is going to be the only ones who +are being recorded on tape + +saying things embarrassing. + +I'm assuming if you say +something extremely smart we + +can keep it though. + +AUDIENCE: [LAUGHTER] + +PROFESSOR: So there +is no danger. + +Feel free. + +Just ignore them. + +And hopefully, the idea is that +if it works well, it will + +be one of these classes that +people can take on their own + +down the line. + +Anything else? + +Any questions? + +No questions? + +When you speak, at the +beginning, if you at least + +would state your name so +that I can possibly + +get to know who are. + +I can address you +by your name. + +That would be nice. + +And otherwise, we're +ready to roll. + +Shall we dive in? + +Let's dive in. + +So, in the video that you saw +last time, you saw quite a few + +people who were maybe trapped in +some kind of poverty trap. + +So for example, there was this +farmer who, before he was + +given fertilizer, had +very low yield. + +And because he had +very low yield he + +didn't have much money. + +Because he didn't have much +money, he couldn't buy + +fertilizer and, therefore, +he continued to + +have very low yield. + +And what the Millennium Village +Project did is to give + +him the fertilizer. + +And the hope was, that with this +first gift of fertilizer, + +his yield would increase by a +sufficient amount that, down + +the line, he would be able to +buy his own fertilizer. + +And grow more and more maize. + +And then, progressively, maybe +start feeding his children + +better and buying them books +and all of those things you + +want to think about. + +So in that video, the Sachs and +Jolie video that you saw + +last time, this argument that +there might be these poverty + +traps keep coming over +and over again. + +So for example, in the Kennedy +story with the farmers, you + +see it in the schools. + +The schools don't have computers +so the kids cannot + +really learn well. + +You start putting computers +and kids can learn better. + +They will then make +more money. + +They will then be able to buy +computers for their schools, + +et cetera, et cetera. + +So one of the things that we +are going to do a lot of in + +this class is to try to +understand when there are such + +poverty traps and +when, in fact, + +maybe it's not so obvious. + +And for that, we have to +understand what creates the + +conditions for such poverty +traps to emerge. + +So what I want to do today-- + +we are going to delve in on one +example of one particular + +poverty trap and how +that could work. + +Which is going to be the fact +that we are physical, + +biological bodies. + +But what we're going to go +over as a mechanism, it's + +going to carry us during +the entire class. + +We are going to have to be +looking for the same type of + +conditions. + +So I want to start with +a story of someone + +that actually I met. + +I met some guy called +Pak Solhin. + +Pak means mister. + +Mister Solhin. + +So people in Indonesia don't +really have a first + +name and last name. + +They just have a name. + +And so, for example, Mrs. +So-and-so is Ebu-- + +I would be Ebu Esther, +for example. + +So this guy is Pak Solhin. + +And I met him in a village +in Indonesia-- + +in Java, which is one of the +richest parts of Indonesia. + +This is the main island, most +densely populated-- + +in the summer of 2008. + +In the summer of 2008, I was-- + +probably for you it's already +ancient history, it's before + +the great collapse of the +world economy and stuff. + +--One of the key events at the +time, for the developing + +countries in particular, +was that the food + +prices were very high. + +Basically since 2005, food +prices have increased + +enormously in the world for +reasons that are not fully + +understood. + +And then they collapsed +again when the whole + +economy went berserk. + +The world economy went away, +the food prices also + +collapsed, and they have started +to increase again. + +Part of the hunger that +you see now-- + +in Egypt, Tunisia, et cetera, +all over the Middle East-- + +part of it is fueled by a +re-increase in the food prices + +which are almost reaching +the 2008 level. + +For people in urban areas, +this has, of course, + +immediately threatened +their livelihood. + +Because they don't +produce food. + +They buy food. + +So as soon as the food prices +increase, that immediately + +affects them. + +So the beginning of 2008, +2007 you observed this + +kind of food riots-- + +nothing like we are seeing +now in Egypt-- + +but dis-content in various +urban areas. + +And generally, people were +wondering what was happening + +to food prices. + +What people have been thinking +is that there are several + +factors that are responsible +for the + +increase of the food prices. + +One is there are many more +people in China and India + +making more money. + +And as they are making more +money, not only they eat more + +but, more that that, +they eat more meat. + +And it turns out that to produce +1,000 calories of + +meat, you need much more +grain than to produce + +1,000 calories of grain. + +That may sound strange, but it +turns out that the cow is not + +a very efficient way to +transform the calories from + +grain into calories +that we eat. + +The cow has started by using +a lot of it, et cetera. + +So to produce 1,000 calories +of cows, you need much more + +than 1,000 calories +worth of grain. + +So as China and India is +becoming richer and eating + +more meat, then there is a +demand for more grains. + +That's one. + +The second thing that is +happening is bio-fuels. + +With the increase in the world +prices of fuel there is more + +and more demand for bio-fuels, +so entire strips of Brazil + +have been covered into +maize that is being + +used to make ethanol. + +A third thing is oil is actually +an input into the + +production of food. + +Because oil is a very important +input into the + +production of fertilizer. + +So as the price of oil increase, +the price of + +fertilizer increase, +and therefore the + +price of food increases. + +So all of these factors are +fundamental forces which + +explains why, after the short +dip right after the crisis, + +the food prices again +started to increase. + +So that's the backdrop +of my visit to + +this village in Indonesia. + +And I met this guy. + +And he was all alone. + +He has a small, dingy, +little house. + +And he was a bit depressed, +or very depressed. + +And why was he depressed? + +Well he was depressed because +he was all alone at home. + +And he was all alone at home +because his wife had gone to + +the city to start working +as a maid. + +His oldest son had also gone to +the city to start working + +as an apprentice on a +construction site. + +And the two young kids were +with the grandparents. + +So he was all alone, he didn't +have anything in his house, he + +didn't do all that much, +and he wasn't happy. + +So the question is, why +did that happen? + +Why was he not working? + +And what he explained to me +is that he was not working + +because he didn't have a job. + +And he didn't have a job because +when the fertilizer + +prices increased, the farmers +that used to employ him + +decided that they had to do +something to cut costs. + +They weren't very sure whether +they were going to be able to + +sell their outputs and they were +facing those increases in + +expenditure. + +So they decided they +had to cut costs. + +And so they could have done +one of two things. + +What could they have done? + +Yeah? + +AUDIENCE: They could have cut +wages or cut the number of + +people employed. + +PROFESSOR: Right. + +They could have cut wages or +they could have cut the number + +of people who worked for them. + +So of course, if they had +cut wages, he still + +would have a job. + +But instead, they +cut employment. + +And why did they cut employment + +rather than cut wages? + +Well his theory was that if they +had cut wages, his wages + +would've been so low that he +would not have been able to + +buy enough food-- + +especially as the food prices +were rising at the same time-- + +with the equivalent of one day +of wage that would have been + +too little to sustain himself +to be strong enough to + +actually work for a whole day. + +So seeing that, the employer, +instead of cutting the wage + +and therefore making him unable +to work, then you give + +a wage of someone, let's +say, 1,000 rupiahs-- + +1,000 rupiahs is not enough to +get yourself energetic for a + +full day of work. + +So you've spent your 1,000 +rupiahs but the person can't + +feed himself for +a day of work. + +You get nothing out of him, +so there's no point. + +Yes? + +AUDIENCE: The question that came +to my mind was, is there + +any truth to his theory? + +Did you find any other examples +that would back up + +that that's the reason why the +farmer, that he used to work + +on his land, decided to cut +jobs instead of wages? + +PROFESSOR: Right. + +What you're asking +is whether-- + +that's fine-- whether maybe +it's a plausible theory. + +But is there any truth to it? + +We're going to spend a fair +amount of time on this very + +question, not on Tuesday, +but starting Thursday. + +In terms of the empirical truth +of his theory, in terms + +of the biological soundness +of it, it + +sounds plausible a priori. + +That you need to start with a +certain number of calories + +just to get going, right? + +Your body needs maybe 1,000 +calories just to survive. + +So the first thousand calories +that you're consuming are not + +very useful to you to help you +to actually start exercising. + +Then, once you are alive, +the next calories + +will start being useful. + +So a priori, maybe +there was some + +plausibility to this theory. + +That's only one theory. + +So that means that he +lost his job so he + +couldn't do much of anything. + +He was not doing nothing, +otherwise I would + +not have met him. + +He would be dead. + +But he was doing things that +was not taking too + +much effort for him. + +For example, he was sitting next +to the bank of a lake and + +he was fishing. + +He was getting a little +bit of rice from + +the government program. + +He was getting a little bit +of meals from his brother. + +But he was not really +living a full life. + +He was sort of surviving. + +So at the heart of +his theory-- + +and I think your question of +whether this is true or not is + +a very interesting question +which certainly came to my + +mind when I was talking +to him-- + +but at the heart of this +theory was this purely + +biological mechanism. + +And then on top of this +biological mechanism, other + +things crept up. + +One is the fact that he was not +doing anything, and that + +his kids were gone. + +That made him depressed so +then it gave him very low + +energy to actually +you do anything. + +So even if his theory was +wrong, he sort of became + +trapped in a poverty trap that +may have been more of a + +psychological one. + +Because he was there, sitting +all alone in his hut, unable + +to do anything, thinking that +he was worthless, therefore, + +in some sense, becoming +worthless. + +There are other parts of his +stories where we start seeing + +other bits of poverty trap. + +For example, what happened +with his kid. + +So the kid who had to drop out +of school to start working as + +a construction worker was +actually a bright kid. + +So that's another place +where you see now an + +inter-generational +poverty trap. + +Where because the parents are +poor, the kid has to drop out + +of school because he has to go +to work and therefore himself + +will probably make less +money down the line. + +And that's another thing where +we have to ask exactly the + +same question you were +asking before. + +Is it an isolated example? + +Or is it something that +is generalized. + +That it's actually something +like the inability to work for + +the parents, or the lack of +income, that forces kids to + +stay out of school that +could have otherwise + +have gotten an education. + +That's another place where we +can find, potentially, a + +poverty trap. + +Where the kid got +some schools. + +He got a few years of school but +maybe not enough for it to + +be sufficient for him to +actually get a good + +job down the line. + +And for himself, he couldn't +work as a construction worker + +because he was too weak for the +basic jobs which require + +some strength, and too unskilled +for the better jobs, + +and too old to be an apprentice +like his kid. + +He was kind of trapped. + +So what is happening in this +story that you would think-- + +even if we accept the biological +mechanism, which I + +want to go back into in +detail in a moment-- + +something else could +have happened. + +So for example-- + +if we're thinking that his +being out of a job is a + +temporary phenomenon-- + +maybe he could have gotten a +loan to sustain his family so + +that the kid could at least stay +in school until the time + +for him to graduate. + +Then at least you wouldn't +have that + +inter-generational trap. + +So at the heart of it, we have +this biological phenomenon and + +then other things sort of creep +in that maintain him in + +this position that creates +the poverty trap. + +So what I want to do now +is go through the + +biological story in detail. + +And then we're going to see how +the other things add up, + +creep in, and create +that trap. + +So let's go through the +biological poverty trap. + +I should say that it's +one of the most + +ancient ideas in economics. + +A very old idea . + +It dates at least +from the 1950s. + +And this is an old +idea exactly in + +this form of the biology. + +So the idea is that the first +few calories that you get to + +consume are used by your +body just to survive. + +So they don't make you strong. + +And then, when you start eating +enough to survive, the + +next calories start giving +you strength. + +So that's when you can start +working out or you can work. + +So someone who is very poor, +like Pak Solhin, may not have + +enough to eat to be very +productive but if he could eat + +more, then he would +become productive. + +So at the heart of this is this +idea of what they call a + +capacity curve. + +And a capacity curve has +something like this shape. + +It relates how much effort you +can exercise to how much + +income you have, and, of course, +how much income you + +have is supposed to be related +to how much you consume. + +So what is the assumption that +is underlying the fact I have + +put income here on the x-axis? + +Yep? + +AUDIENCE: The more money you +have the more you eat. + +PROFESSOR: Right. + +The more money you have +the more you eat. + +So for example, the simplest +case would be, all + +you have, you eat. + +Of course, we know that it's not +true because you also need + +to take care of your +basic needs. + +You need to clothe yourself. + +You need to pay your children's +school fee. + +Maybe you need something +for your housing. + +So maybe you will only consume +a part of your income. + +But maybe some fraction +of what you have, + +you're going to eat. + +So that creates a relationship +between the income you have + +today and how much +you get to eat. + +So instead of income here, we +could have calories consumed. + +And one first big question that +we'll have to answer next + +time is, how steep is this +relationship between how much + +income people have and how +much they are eating. + +Here we are assuming that there +is some relationship and + +it's formidably steep enough. + +So whenever you have income, +you start eating. + +And what we have here on the +left, on the x-axis is the + +work capacity. + +So how many bushels of wheat +are you able to harvest or + +something like that. + +How many trenches can you dig. + +So the work capacity, +you think of + +it as physical output. + +But of course, there could be +a relationship between this + +physical output and your +income tomorrow. + +Because, for example, you could +be paid by the piece. + +So if you're paid by the piece, +however many bushel of + +wheat you harvest, you +get that much income. + +That creates the work capacity +and your income tomorrow are + +related one for one. + +Right? + +So here we have income +today, work capacity. + +And instead, we could +have income + +today and income tomorrow. + +OK? + +Now why is this shaped +the way it is? + +What does the shape represent? + +AUDIENCE: The left part is the +part where your body is just + +able to survive. + +And then afterwards he gets a +chance to actually make more + +money tomorrow because +[INAUDIBLE]. + +PROFESSOR: Exactly. + +So the left part is the first +part where you're just getting + +enough to survive. + +You are just eating +enough to survive. + +So the first few calories are +good because they keep you + +alive so you can actually +move about. + +But after that it just keeps you +at this kind of low level. + +Right? + +And then you start having, maybe +1,200, 1,500 calories. + +And then suddenly, it's a good +breakfast you're eating before + +going out for your run. + +It shoots up and then, why does +it flatten out again? + +Yeah? + +AUDIENCE: Because after a while +you're satisfied and it + +levels out once [INAUDIBLE]. + +PROFESSOR: Right. + +After a while it satisfy +and it levels out. + +And if we had continued the +curve, what would happen? + +It would really go down. + +Just think of post-Thanksgiving +slump and + +she probably gets a deep +down going line. + +So that creates this kind of +funny shape between you're + +income today and your work +capacity and, therefore, + +between your income today and +your income tomorrow. + +Or it could be within a week or +something like that, right? + +Which seems to have a reasonable +biological sense. + +Now what happened when the +price of food went up? + +What does it do to the +work capacity? + +Yeah? + +AUDIENCE: I suppose it goes down +because those people have + +to spend more of their +income on food and + +then buy less food. + +PROFESSOR: Exactly. + +So what happens when the price +of food goes up is that, in + +terms of bushels of wheat, +that's the same thing. + +But in terms of actual income +that the bushel of wheat + +transform into-- how +much income-- that + +creates a jump down. + +Because to go from income to +work capacity, to create from + +income today to calorie, +that's more expensive. + +So the curve shifts down because +for every dollar that + +you spend, or rupiah that you +spend on food, that's fewer + +calories and, therefore, that +shifts down whatever you are + +able to achieve in terms +of capacity, right? + +So if we have it in the form +of income to work capacity, + +the prices of food going up +makes the curve going down. + +Yeah? + +AUDIENCE: Could you also, if +you were talking about + +students, instead of saying the +word capacity, I'd put the + +way you pay attention? + +Would they pay more attention +if they ate more? + +Or is it just physical spending +that [INAUDIBLE] + +PROFESSOR: Right. + +Here, if we're thinking of Pak +Solhin, we are thinking about + +physical [INAUDIBLE]. + +But if we're thinking about +Pak Solhin's children, for + +example, it could well be their + +capacity to focus in class. + +And it could easily have +the same shape. + +In fact, there are other thing +that competes also for + +calories for children. + +For example, whether or not they +have intestinal worms. + +And the intestinal worms also +shift your work capacity, your + +attention capacity, +down because they + +are eating your food. + +Therefore, that tends to make +the kids anemic and less + +likely to be listening. + +That's exactly right. + +Yeah? + +AUDIENCE: And so increase in +food prices, does that cause a + +shift or a stretch? + +PROFESSOR: It specifically +causes shift and a-- + +how would you call it, +west-southwest, right?-- + +It is both a shift +and a stretch. + +Which is, it will take more of +your income today to have you + +switch to the-- + +think of it going this way. + +And alternatively, +what happens when + +the wages go down? + +That's another thing +we can look at. + +What happens to the +work capacity? + +Not to the work capacity, but if +we put income on the y-axis + +now and the wages go down? + +AUDIENCE: It shifts lower. + +PROFESSOR: It again will do the +same thing because now the + +same work capacity will +translate into less income. + +So what was happening in +Indonesia in 2008 was, on the + +one hand, food prices +were going up. + +On the other hand, farmers were +stressed out because the + +input prices were going up. + +So at the same time they wanted +to reduce the wages + +when the prices were +increased. + +And both of these phenomenon +create this southwest shift in + +the capacity curve. + +Yeah? + +AUDIENCE: Why didn't the farmers +just increase the + +prices they were selling the +crops at [INAUDIBLE]? + +PROFESSOR: That's an excellent +question, so why didn't the + +farmer just increase +the prices? + +The thing is that with the +agricultural cycle, you + +produce and then-- so you put +your fertilizer in the ground, + +then you put your crop +in the ground and + +then you wait around. + +Then the crop comes and +you try to sell it. + +And you're exactly right, the +fact that the input prices + +have gone up while the demand, +in principal, would + +not have gone up. + +It would have meant that the +food prices sold by the farmer + +would probably go up. + +But what happened is that they +weren't very sure whether or + +not the food prices were going +to go up by the time they sold + +their food in proportion +to the input prices. + +So the situation that prevailed +in 2008 is a lot of + +volatility. + +The prices were high but they +were also increasing. + +And that was true for the input +prices and that was true + +for the output prices. + +And when you were talking to +the farmer, everybody felt + +that they were holding the +short end of the stick. + +The farmers were saying, +well, yes, the + +food prices will increase. + +But we don't know whether it +will increase enough to cover + +our input prices. + +Moreover, the farmers found +it difficult to + +get loans, for example. + +So even if they know that the +prices are going to go up for + +that input in the future, in the +meantime, they still have + +to buy the fertilizer. + +So they sort of had +to cut costs now. + +So this is a little bit +what was happening. + +It's a mismatch between the +price you have to pay for the + +fertilizer today. + +And you're going to realize +the output in the future. + +So that creates this uncertainty +plus the fact that + +you need to finance it +one way or the other. + +Which is why, at that time, +there were two things going on + +which were both against +the poor guy. + +So this is what we have with +the capacity curve. + +So we've had this reasoning for +food but let's think a bit + +about other reasons-- + +forget that we are talking about +physical work capacity. + +Think about other reasons why +there might be a relationship + +between your income today +and an income at some + +point in the future. + +Think of the next generation, +think of next month, or + +anything like that. + +Can you think of other reasons +why this kind of funnily + +shaped curve might appear? + +So food might be one. + +What would be other reasons why +this funnily shaped curve + +might appear? + +Yeah? + +AUDIENCE: Over the long +term, maybe education. + +PROFESSOR: So let's go through +the education one. + +Why do you think-- + +AUDIENCE: Before, the less long +you can afford to keep + +you're children in school. + +And so their income capacity +isn't as low as yours was. + +But the richer you are, the more +schooling you can get and + +the higher income you +can [INAUDIBLE]. + +PROFESSOR: So this is right. + +That there is probably a +relationship between how long + +you can keep the +kid in school-- + +because if there are school fees +you might or might not be + +able to afford them. + +Or there might also be an +opportunity cost for the child + +to be in school. + +Like Pak Solhin's son couldn't +afford to be in school because + +he had to work. + +So I think it's not very +controversial to say there + +might be a relationship between +your income today and + +how long your kid will +stay in school. + +And then, there is probably a +relationship between how long + +your kids can stay in school +and their income. + +Which will create a relationship +between your + +income today and the income +of the child. + +So that creates a relationship +of some form or another. + +But what would be necessary for +this relationship to have + +this S-shape? + +So what you have explained, I +think and I think most people + +would agree-- + +we can ask around-- but I think +what you have explained + +clearly is that we might expect +through education-- + +a relationship between +income today and + +income of the children. + +Now what else do you need for +that relationship to have this + +funny shape? + +AUDIENCE: At the start, you +need to invest more. + +So like if they just learn to +fifth grade, or if they just + +learn to second grade, it isn't +going to make that much + +of a difference. + +But as they finish middle school +and high school, it's a + +much steeper curve. + +But then, going to college +versus Ph.D. levels off. + +PROFESSOR: Yeah. + +Sadly, going to a Ph.D usually +leads to a drop in income + +compared to having gone +to a Master's. + +Especially if you choose +the Master's properly. + +But this is exactly +that, which is we + +need one more thing. + +What you're saying +is exactly right. + +What's your name? + +AUDIENCE: Yousef. + +PROFESSOR: Yousef. + +But what she told us is you +need one more thing. + +You also need for the benefits +of the first few years of + +education to be relatively +low. + +And that's an empirical question +that goes back to the + +plausibility question that +you were asking earlier. + +Is it the case that the first +few years of education are + +useless, or not very useful? + +Or is it the case that every +year of education + +is a year of education. + +And there will be an S-shaped +based on education if the + +first few years of education +are not that useful. + +And [INAUDIBLE], if in fact, +even the first few years of + +education are that useful. + +I'm not going to answer +this question now. + +But we are going to answer it in +due course, whether or not + +this is the case. + +You see that this is not +something that we can just + +think of in the abstract. + +We have to find out. + +There could be reasons +the other way. + +You could feel, for example, +that the first years of + +education are amazingly useful +because this is when + +you learn to read. + +And once you know how to read, +who cares about all of these + +things that I'm trying to teach +you because you can + +teach yourself everything +you need to know. + +Or you could think that +education is not useful unless + +you have a secondary degree. + +Because that's what opens +the door to you for + +various formal jobs. + +Right? + +It could easily cut one +way or the other. + +I don't know if you guys +have an insight. + +For example, what +is your view? + +Do you think that this is likely +that the first few + +years of education are +not so useful or-- + +AUDIENCE: I think the first +few years are very useful + +because some people +learn to develop, + +like, love for reading. + +And actually realize that they +can learn things by reading + +[INAUDIBLE]. + +PROFESSOR: So for example, you +think that, the first few + +years of education +are very useful. + +So there would be a relationship +between income + +today and income +of my children. + +But it wouldn't have this shape +if that is the case. + +In fact, it might have a +completely opposite shape + +where it's more like an inverted +L as opposed to an S. + +So education would be one. + +What would be another +possibility for this funnily + +looking shape to appear between +income today and + +income at some point +in the future? + +Is it on my income in the future +or the income of my + +children or my income +next year? + +What would be other sources +of such shapes? + +Yeah? + +AUDIENCE: Access in knowledge +of, like, the job market. + +In the sense that if you were +raised in a family that's a + +higher income and so, therefore, +your parents would + +teach you more from a younger +age and would allow you to + +have a higher income. + +PROFESSOR: Right. + +So for example, for access +to the job market, it is + +possible-- if I can rephrase +what you are saying-- that + +people who live in a village, +their horizon is the village. + +Where they are growing +whatever. + +They are growing stuff and they +are making some income. + +But they don't have the +perspective in mind that they + +could go to the city where +there a number + +of other jobs available. + +So in that case, for people who +have very little money and + +live in the village, well, their +children will again also + +live in the village and have +very little money. + +If suddenly something opens the +possibility to go to the + +city-- for example, someone +comes into some money, gets + +the option to buy a train +ticket, goes to the city and + +figures out the options there. + +Then suddenly you have access +to a number of other + +opportunities, potentially +much more rewarding, that + +would potentially create +this S-shape. + +Where the fact of being poor +means that you live in a + +relatively restricted +environment. + +You stay there. + +And then when you become just a +bit richer, that opens this + +opportunity that helps you +you become much richer. + +That's a very nice example. + +Yeah? + +AUDIENCE: Another option is +savings which depends on how + +much income you have. + +Because the more you save, the +more you invest and the higher + +income producing activities. + +So the poor people have +no money to save so + +they're stuck there. + +But as they get more income you +can afford to save more + +and invest more and it pushes +your future earnings. + +PROFESSOR: Right. + +So saving is a very interesting +example. + +Again you could say-- well, +suppose for example, that + +people saved some fixed fraction +of their income. + +Then if I have more income +today I will save more. + +Therefore, I will invest more, +therefore, I will be richer in + +the future. + +Now if it was a fixed fraction +of my income, again, I would + +definitely see a relationship +between income today and + +income tomorrow just because +I save more. + +But if it's a fixed fraction of +my income, what else do I + +need for this S-shape to come? + +Yes? + +AUDIENCE: You need for poor +people to not be able to save + +this fraction. + +Because they, for instance, +spend their money on food or + +things that they need +to buy today. + +And so are either a fraction +of [INAUDIBLE] + +income or it's just lower +for poor people. + +PROFESSOR: Right. + +So the first possibility for +an S-shape to appear due to + +savings is that actually people +do not save a fixed + +fraction of their income. + +Is that for some reason, the +poor save less than the rich. + +So if that's the case-- and +let's talk through whether we + +have reasons to think that +the poor would save + +less than the rich-- + +but let's first take it as given +for a moment, and let's + +assume the poor save +less than the rich. + +And if that's the case-- + +assume the poor save nothing-- + +then if you're very poor, you +have no income tomorrow coming + +out of investments. + +And then if you start saving +when you become a little + +richer and that money is +invested, that starts creating + +some return for that money and +you get into this steeper part + +of the S-shape. + +So that's a first mechanism +through which savings could + +create a relationship between +your income today and your + +income tomorrow that would +have this S-shape. + +Now what we do have to explain +is why is it the case that the + +poor would be able to save +less than the rich? + +And that is something that, I +think, we all have in mind. + +Say, yes, of course, the +poor don't save because + +they have no money. + +But one thing I want you to keep +in mind is that the poor + +have no money but they +have a present + +and they have a future. + +So unless they think that they +will have more money tomorrow + +or unless, for some reason, they +are extremely impatient, + +then the poor should want +to save as well. + +Because, of course, today +they have very + +little money for food. + +But tomorrow they'll have very +little for food as well. + +So we need to go a little +further than to say, well, of + +course the poor save because +they have no money. + +Right? + +Again, let's not go into +the details of that. + +I think there are good reasons +to think that the poor would + +be less able to save +than the rich. + +And we're going to have +a whole set of + +lectures about that. + +But just keep in mind that it's +not so obvious that the + +poor would be less +likely to save. + +Another-- + +sorry, you wanted to talk. + +AUDIENCE: [INAUDIBLE] + +access to healthcare +and medicine. + +PROFESSOR: Right. + +So let's go to health. + +Let's finish saving +and then I'll go + +back to you for health. + +Another reason why there might +be a relationship between + +income today and income +tomorrow of + +this form due to savings. + +Suppose that the poor and the +rich saved both a proportion + +of their income. + +There could still be a +relationship like that. + +Yeah? + +AUDIENCE: The rich could be able +to invest their savings + +more effectively. + +PROFESSOR: Exactly. + +It could be that the rich have +access to better investment + +opportunity. + +For example, it could be that +the bank is just not + +interested in very small +saving accounts. + +And in fact, it's the case +that the banks are not + +interested in very small +saving accounts. + +Because as soon as you're a bank +and you take the saving + +of someone, the government is on +your back to make sure that + +you don't run away +with the saving-- + +which is a good idea-- +but that costs money. + +So maintaining a saving account +for someone costs some + +amount of money. + +And regardless of the size of +the account, it still costs + +the same money because you need +to do all the paperwork. + +So as a result, if you come to a +bank with your five rupiahs, + +the bank is going to say, thank +you, but I don't want + +your five rupiahs. + +Whereas, if you come with your +5,000 rupiahs they're, sure, + +I'm going to put it in this very +nice account for you with + +a nice return. + +So that's one reason +right there. + +That the poor might have to save +under the mattress where + +the money might disappear. + +Where it might be stolen. + +And so the return on +saving for the poor + +might be very low. + +It might even be negative. + +Whereas, the return for the rich +might be higher, either + +because they have access to this +savings account or they + +can, for example, start +a small business. + +For example, when you want to +start a small business, is it + +worthwhile starting a tiny +business with almost nothing? + +Maybe not. + +Maybe it needs to be large +enough for it to be + +worthwhile. + +So even if the poor and the +rich were to save the same + +amount proportionally, there +might still be something + +related, not to how much they +save, but what's the + +productivity of those savings. + +You were talking about +health care. + +Why don't you tell us what +you're thinking about + +healthcare. + +AUDIENCE: So at lower incomes +you can't really + +buy a lot of medicine. + +And maybe you can reach a point +where you can start + +buying medicines or +buying healthcare. + +And maybe towards the end when +you have higher income, it + +levels off because you don't +encounter the health problems + +that you might at low incomes +in the first place. + +PROFESSOR: Right. + +So healthcare might be another +source of that. + +For example, if you're very +poor, you might not be able to + +purchase very simple, relatively +cheap technologies + +that prevent you from +getting sick. + +It could be a covering +for your water. + +It could be a water filter. + +It could be a bed net to put on +top of your kids when they + +sleep so that they don't +get malaria. + +So all of these things might +all be like some fixed + +investment that, if you +can't afford them, you + +can't afford them. + +And then you are getting sick +more, therefore you are less + +productive, therefore you make +less money, et cetera. + +So that's another source where +we would have this S-shape. + +Then we again have to think +about these goods as things + +that are a little bit lumpy. + +Like a bed net, for example. + +Or a water filter. + +That you can either afford +or not afford. + +So if you have enough money you +afford it and then you can + +be generally healthier. + +You don't lose all your calories +to diarrhea and other + +nice things like that. + +And if you're poor you would +be sick all the time. + +Or paying for the doctors, +for example. + +So for example, if someone is +sick and very poor they might + +not be able to pay +for the doctor. + +Then they'll stay sick so +they can't earn money. + +And again, a doctor visit is one +big lump investment which + +you may or may not be +able to afford. + +That would be another source +of an S-shape like that. + +So the reason why I went through +all of these examples + +is that we are going to have a +lot to say about the exact + +story that Pak Solhin told +me about the food. + +Whether this was a real story +in this case or whether it's + +some stuff that he was telling +himself to explain the + +situation he was in but, really, +there was something + +else behind his problems +like depression or + +something like that. + +But the first time it was +formalized was in this context + +of nutrition. + +And it's very natural to think +of it in the context of + +nutrition but it could apply. + +And a very important part of the +discussion that I want you + +to keep in mind is that it's not +enough for there to be a + +relationship between income +today and income tomorrow. + +To create a poverty +trap it needs to + +have this funny shape. + +And I want to discuss why. + +So the way that we are going to +think of it is we are going + +to think about what +is the dynamic of + +someone's income over time. + +So let's start with this picture +which brings inherited + +income on the x-axis-- + +so think of it as +income today-- + +and income from work. + +What I have plotted here +is this S-shaped curve. + +Think of it, for example, as +coming from nutrition. + +But any of the examples that you +talked about if you don't + +like the nutrition one. + +And the line that goes through +the diagonal is + +the 45-degree line. + +So why is the 45-degree line +relevant and interesting here + +is that, , on the 45-degree +line, income today is the same + +as income tomorrow. + +Right, so we're going +to make use of it. + +Now I want to try and look at +the dynamic of someone's + +income over time. + +So suppose someone got this +little income, y prime 0. + +Where do I read their income +in period one? + +Yep? + +AUDIENCE: It would be going +from curvy line to the + +45-degree line horizontally. + +PROFESSOR: Exactly. + +So to go from income y prime 0 +to y1, I go on the vertical + +line up to the curve. + +That tells me this is what +someone who starts his life + +with some income, yi0, can make +his decision about how + +much to eat, creates some +calories, creates some work + +capacity, goes to work, +generates an income that he + +takes home. + +That's the income that we +have on the curvy line. + +And then I want to say, well, +that becomes y1, right? + +And then y1 is going to become +the y0 of tomorrow. + +So to find it, I'm doing exactly +what you're saying + +which is I'm going +horizontally to + +the 45-degree line. + +And I could go down again. + +So from y0, I go to y1. + +Then horizontally +on the 45-degree + +line gives me y1 again. + +And then how do I find y2? + +I go vertical again, +that gives me y2. + +I go horizontal again to +the degree line and I + +continue like that. + +And where will I end up? + +AUDIENCE: Where the two +curves intersect. + +PROFESSOR: I will end up at +the intersection of the + +45-degree line and the +S-shape curve, right? + +At the first intersection. + +Now what if I start with +a higher income. + +If I start with the income +y 0 double prime. + +I go vertical to the curve. + +That gives me y1 double prime. + +I have to go horizontally +to find it when it + +becomes income tomorrow. + +Again vertically, et cetera. + +And I again end up at the +intersection of the 45-degree + +line and the S-shape curve +but now it's a higher + +intersection. + +Now what happens if I start at +the sixth point in the middle + +over there? + +Which way will that go? + +AUDIENCE: That will go down. + +PROFESSOR: That will go down. + +If I go to the sixth point, +I go vertical + +then left then down. + +So what is the key point after +which I will start going to + +the high point? + +Yeah? + +AUDIENCE: Where it intersects +the 45-degree line again. + +PROFESSOR: So the intersection +from below. + +So at this point P where the +capacity curve intersects the + +45-degree line from below. + +Anything to the right goes +to the high steady state. + +Anything to the left goes +to the low steady state. + +So this possibility that there +are two steady states + +depending on where you start +from is the formalization of + +the poverty curve. + +Which is anybody who is poorer +than the unstable equilibrium + +over there-- + +if someone starts with exactly +this income, where do they go? + +If someone starts with exactly +the intersection of the + +45-degree line and the S-shape +curve, do they go down or do + +they go up? + +They just stay there. + +So it is also a steady state but +it's a very unstable one. + +If anything happens, any +small perturbation. + +If they go slightly +to the left, they + +go all the way down. + +If they go slightly to the +right, they go all the way up. + +So we call that an unstable +statistic. + +So there is one unstable +statistic and two stable ones. + +And those two stable ones is +what we're talking about. + +They could be a poverty trap. + +Yes? + +AUDIENCE: Why are they moving +toward that 45-degree line? + +PROFESSOR: Can someone +explain that? + +You want to know why we are +going horizontal to the + +45-degree line? + +Yeah. + +Can someone explain that once? + +And then I'll re-explain +it as well. + +AUDIENCE: Because yesterday's +income is going to be your + +today's income. + +And your today's income +is going to be + +your tomorrow's income. + +So if we start with a value +zero, so that value + +can come from work. + +It's going to be tomorrow's +[INAUDIBLE]. + +So if you get the income from +work, the y-value of that will + +be your incurred income +tomorrow. + +So you have to go to +the 45-degree line. + +PROFESSOR: Exactly. + +The reason why we are using the +horizontal line is that-- + +so from y0, I know +that I go to y1. + +And then I want to know, +from y1 where do I go? + +For that I need to put +y1 on the x-axis. + +And the 45-degree line allows +me to do that because the + +45-degree line is where the +vertical is equal to the + +horizontal. + +So I'm going right to find y1 +on the horizontal line which + +helps me to find it +on the x-axis. + +And then I know that from +y1, I go to y2. + +And then again horizontal, and +then again vertical, and then + +again horizontal. + +That makes sense? + +Is it clear for everybody? + +It would be better if we were +all on the same page. + +That we have that here. + +This is not obvious. + +It's not meant to be obvious. + +Yeah? + +AUDIENCE: [INAUDIBLE] + +y0 or y1-- + +PROFESSOR: So, the first +one you mean? + +AUDIENCE: Oh, is that +because that's the-- + +PROFESSOR: That's the +capacity curve. + +Exactly. + +Your y0 is what you +start from. + +And then the curve gives us +what is the relationship + +between income today and +income tomorrow. + +So think of it with +the food example. + +You start with some income. + +You decide how much to eat-- +let's say you eat + +80 percent of it-- + +you eat it. + +That gives you some strength. + +You go work. + +That gives you some wage. + +That's your income from work. + +AUDIENCE: And then, when we're +determining the distance + +between y0 and y1, is that +determined just by the + +distance from the curve +to the 45-degree line? + +PROFESSOR: Exactly. + +So y0 goes to y1. + +Do you understand the first +vertical step here right? + +y0 goes to y1 for the +first vertical step. + +And then we're looking for y1 on +the vertical axis, but now + +we need to find a way +to put it back on + +the horizontal axis. + +And the 45-degree line helps us +to do that because on the + +45-degree line the vertical +distance is the same as the + +horizontal distance. + +So the horizontal line is just +a trick to help us find where + +is y1 on the horizontal axis, +which helps us go to y2. + +That make sense? + +So from y0, I go to +y1 vertically -- + +that's just a capacity curve. + +Then the horizontal line +is just to the left. + +Now what is the new y0? + +The new y0 is y1. + +And then again, we go +vertically to y2. + +Horizontally to find it on +the horizontal axis, + +vertically, et cetera. + +Yeah? + +AUDIENCE: What's the +unit of time-- + +PROFESSOR: The unit of time is +whatever we think is the right + +unit of time depending on the +problem we're looking at. + +So, for example, if it is food, +that might be the date. + +If it's the income of your +children, that may be a + +generation. + +In some sense, once we have +decided what problem we are + +looking at, the unit of time +doesn't really matter. + +We adjust to it. + +Yeah? + +AUDIENCE: How did you determine +which states were + +stable and which ones +were not stable? + +PROFESSOR: Well, look at it, +and for any point, you're + +figuring out whether or not +you're going to stay here. + +Whether things tend to bring you +back here or things tend + +to pull you away from it. + +Think of it, for example, +as magnets. + +Either they cling together or +they are trying to go away. + +Or think of it as a stick. + +Does it stay vertical or +does it fall down? + +Suppose that we start with +income and the first income we + +are getting is y3. + +That's going to pull you. + +You're going to go vertical +a little bit, horizontal a + +little bit, et cetera. + +That's going to pull +you exactly + +at that first statistic. + +Right? + +So now, if you start from the +first statistic and something + +slightly pushes you away from +it, it is going to bring you + +back to it. + +If you are a little bit richer +than the first statistic, + +you're going to, again, go back +to the first statistic. + +If you're slightly richer, +it's pulling you down. + +If you're slightly poorer, +it's pulling you up. + +Now, if you're looking at the +one that's here on top, that's + +the same thing. + +At the very top, if you're +slightly poorer, it's pulling + +you up towards it. + +If you're slightly richer, +it's pulling you + +down towards it. + +Now if you look at the one where +the line intersects from + +below, if you're exactly +at it, you stay at it. + +But if you're slightly poorer, +where do you go? + +All the way down. + +If you're slightly richer, +all the way up. + +So that one is not stable. + +So basically, you follow your +arrows wherever they are going + +to take you. + +OK? + +Any more question? + +Yeah? + +AUDIENCE: What are the +axis labels for it? + +Like income from work. + +I thought we were trying to +connect on a time scale-- + +PROFESSOR: Right, so it +doesn't really matter. + +Think of it as income today +versus income tomorrow. + +Or income that you inherited +versus income + +that you create yourself. + +Whatever scales we are +talking about. + +So in the food example, it would +be the income you had at + +the end of today. + +And then, that would be +inherited income you inherited + +from yesterday. + +And then the income from work +would be the income of the end + +of the day. + +So here the scale would +be one day. + +In the education example, you +would go from your income to + +what your children will make. + +That's a whole generation. + +So the time scale, it depends +on the problem. + +I think in the food example, +it's useful to think of a day. + +In the health example +it might be a month. + +AUDIENCE: Why is there a +tendency to move to the + +intersections? + +PROFESSOR: Well, that's where +the arrows are pulling you, + +aren't they? + +Because the closer of +the intersection + +is where you are-- + +first, you go from wherever +you start to the curve. + +And then the curve is +trying to go back to + +the 45-degree line. + +So the closer you are +to the intersection, + +the less you move. + +Which is why this +is, everything + +pulls you back there. + +--Not all the intersections. + +No, it's the stable ones. + +The one to the left and the +one to the right, not the + +middle one. + +Which you have a tendency +to go away from. + +Any other questions +on how this works? + +Yeah? + +AUDIENCE: How do you guys +actually gather the data to + +[INAUDIBLE]? + +PROFESSOR: So that's an +excellent question. + +Right now, I've just +asserted that it's + +the form of the curve. + +And then we have to go back to +the question that a neighbor-- + +whose name I don't know-- asked +earlier, which is what + +is, actually, the shape +of the curve? + +And that's a key question. + +That's going back to the +questions we were asking in + +the case of education, +for example. + +Is the relationship between +income today and income + +tomorrow due to education? + +Is it really of this shape or +is it of another shape? + +That's what we have to +assert empirically. + +And it's going to have +to be gathered on a + +case-by-case example. + +So for example, for food. + +To create this shape, to know +what is the form of the shape, + +we are going to need +to know two things. + +We need to know what is the +relationship between how much + +income you have and how many +calories you consume. + +And what is the relationship +between the calories you + +consume and your +work capacity? + +And the product of the two +will be that curve. + +And the shape it has-- + +God knows, I mean, actually even +we know, but we're going + +to cover that next time. + +So this is assuming that +the capacity curve + +indeed has this shape. + +Then we can see how the poverty +trap can emerge. + +Now, if instead, the capacity +curve had this shape-- + +think of your example +of education. + +And think that, in fact, the +first few years of education + +are very valuable and the next +years you guys are kind of + +wasting your time-- not to speak +of me-- and the next + +years of education are +not so valuable. + +What is really important is +to learn how to read. + +Imagine that's the case. + +Then it means that the +relationship between income + +today and income tomorrow +is not as steep anymore. + +It starts very high and +then it tapers off. + +And so we can play the same +game again that we were + +playing before. + +We can say, well, let's draw +the diagonal line. + +Let's start with some +income, a1. + +To find out income tomorrow +what do we do? + +We go vertical. + +We find income, a2. + +Then we have to go horizontal to +the 45-degree line to find + +it on the horizontal line. + +We go vertical again to +find it on the curve. + +Horizontal again, +vertical again. + +Where do we end up? + +q. + +Now suppose we had started +above q, where + +would we end up? + +q. + +Suppose we had started anywhere +in between, where + +would we end up? + +q. + +So there is no poverty +trap, in this case. + +If there is only one +intersection because the + +returns are first high and then +low, then there won't be + +a poverty trap. + +It doesn't mean that there is no +relationship between income + +today and income tomorrow. + +There is one. + +But the point is, that +relationship is first steep + +and then tapers off. + +So for example, imagine that +the only type of businesses + +that you can run are businesses + +that you can run yourself. + +That for some reason, you are in +a business where you can't + +really have employees. + +Imagine. + +So in that case, your first +investment will be quite + +valuable, right? + +But then, eventually, you can't +really add much more + +because you won't have +enough time to sell + +all of these things. + +So your first dollars invested +will have a very high return. + +And then less and less +and less and less. + +And so in that case, everybody +will end up at the same place. + +An example that could make it +clear, is going back to our + +Kenyan farmer from the MTV +video, Kennedy fertilizer. + +If you put fertilizer +on your crop-- + +well when you put just +a little bit, the + +effects are very high. + +But when you start putting more, +eventually, the soil + +can't absorb it so the +effects are less and + +less and less high. + +So even if you don't have enough +to put on your entire + +field to start with, you could +imagine that you would first + +put it in the most productive +part of your field. + +Because the first unit of +fertilizer you are putting is + +very high return. + +The second, you need less +because you're going to the + +place of your field that is +less productive anyway. + +At the third, you +need even less. + +The fourth is really not that +productive because, now, you + +end up putting more where +you started from + +in the first place. + +So that's not really +helpful anymore. + +So in that case, the returns +don't have this S-shape. + +They have this inverted +L-shape. + +So in that case, there +is no poverty trap. + +And so that is where the +question that you were asking + +is essential. + +Which is, how do we know what +the shape of this curve? + +Because the shape of this curve +is going to crucially + +determine whether or +not we have a trap. + +And what I want you to remember +is that that's more + +than a relationship +between income + +today and income tomorrow. + +It has to be this relationship +of this shape. + +So that's the first thing, which +is if the relationship + +is inverted-- + +L-shaped like that, which +is the canonical case in + +economics, most of our +economics model-- + +what you learn in 14.01-- + +has production function +of this form. + +Where this production function, +which we called, + +have decreasing returns. + +Where the first unit invested is +very profitable and then it + +becomes less and less +profitable. + +We've already discussed a number +of reasons why the + +returns might not would +always be decreasing. + +For example, we discussed the +case of calories where there + +might be an increasing zone and +then a decreasing zone. + +We discussed education might +or might not be that way. + +We got an interesting example +about businesses where you + +might not have a very profitable +opportunity for + +your business if you don't +have enough money. + +We discussed savings, which may +or may not have this form. + +Where nobody wants your +small savings. + +So there are reasons +why it may not + +always be inverted L-shaped. + +But if it is inverted L-shaped +there won't be a poverty trap. + +--You might be very bored with +me repeating the same thing + +for the fifth time now, but +the reason why I insist is + +that this is a confusion that +we hear over and over again + +among policy makers. + +In the policy discourse, +whenever they're thinking of a + +double feedback loop-- + +for example, kids who have +less education, make less + +money, and parents who have +less money send their kids + +less to school. + +Immediately, people think, ha! + +If there is a double feedback +loop like that, that creates a + +poverty trap. + +And the point is, that that's +not sufficient. + +That's necessary but that's +not sufficient. + +Because if the double feedback +loop gives you a nice inverted + +L-shape, eventually, everybody +will end up + +nicely in the same place. + +OK? + +So there is more, which is, here +is another case where we + +have an S-shaped curve. + +But the S-shaped curve is a +little different, it's a + +little higher. + +So why would it be a little +higher, for example? + +Why has it moved up compared +to what we had before? + +Why could it have moved up? + +Go back to the food example. + +Sorry? + +AUDIENCE: Lower food prices. + +PROFESSOR: Lower food prices. + +So for example, the productivity +of the land might + +have gone up. + +Maybe the government came and +built some irrigation dams and + +the productivity of +land has gone up. + +So to produce the same amount of +food you need less effort. + +So the work capacity translates +into a higher + +income for moi. + +So for whatever reason, +the curve shifts up. + +So then what happened-- + +we gave some person +some income, y0. + +We find y1 by going vertical. + +We find it again on the +horizontal line, y1. + +Going back to y2, horizontal +again. + +Et cetera, et cetera. + +Where do we end up? + +At the intersection. + +And now there's only +one intersection. + +So wherever we start, we are +going to end up at the same + +intersection. + +In that case, is there going +to be a poverty trap? + +No. + +In that case there is no poverty +trap because, again, + +there is one statistic. + +So an S-shape is not even a +sufficient condition for a + +poverty trap. + +It is necessary but it's +not sufficient. + +Let's find another example, +which is this one. + +Where in fact, now it's +the opposite. + +There was some flood +and the land is now + +completely washed out. + +So people are very +unproductive. + +They have to work very hard +to produce very little. + +So what happened to +my poor S-shape? + +It's shifted to the +southwest, right? + +So now if I start from y0-- + +quite high-- where do I go? + +So I go up, but then +it's not enough. + +The 45-degree line +is to the left. + +I have to go left, down +again, down again, + +down again, and again. + +I'm going to end up at the +single intersection where I'm + +always pulled up, which +is a very low income. + +So in a sense, there is no +poverty trap here either. + +Because it's not that if you're +poor, you'll stay poor, + +and if you're rich, +you'll stay rich. + +Regardless, you're +going to be poor. + +AUDIENCE: [LAUGHTER] + +PROFESSOR: So you could think +it's a universal poverty trap + +or you can think that's +just the way is. + +Because if you ignore the right +side, we almost are in + +the inverted L-shape except +there are stuff that are a + +little bit irrelevant +to the right. + +The reason why they are +irrelevant is that, + +eventually, everybody's +becoming poor anyway. + +So again, we don't have +a poverty trap. + +So let's look at those +three examples. + +That's an example with +a poverty trap. + +That's an example that +doesn't have one. + +That's another example that +doesn't have one. + +What is different between the +one example with the poverty + +trap and the one which +doesn't have one-- + +or two? + +Yes. + +Can you tell me your name? + +AUDIENCE: Zachary-- + +PROFESSOR: Zachary. + +AUDIENCE: --it crosses the +45-degree line twice. + +PROFESSOR: Exactly. + +Well, twice or-- + +AUDIENCE: Three times. + +PROFESSOR: Three times. + +It crosses the 45-degree +line once from below. + +So the rule is that you're going +to have a poverty trap + +if the capacity curve-- + +or whatever is the curve between +the income from work + +and the inherited income-- + +crosses the 45-degree line, +at least once, from below. + +That is, there is at least one +unstable equilibrium where + +you're crossing from below. + +And that is necessary for +having a poverty trap. + +So what you need, in other +words, is to have a zone where + +income is accelerating. + +And this zone must to be at a +place where the income was + +relatively low to start with. + +And it needs to accelerate +enough that it's becoming high + +to start with. + +In other words, it needs to be +a zone where, if you're below + +the zone, you're making +less tomorrow than you + +started from today. + +And when you're on the right +of the zone, you're making + +more tomorrow than you +started from today. + +And you need to have +this point. + +Otherwise, there is +no poverty trap. + +All right? + +So that's the mathematical +expression of it. + +And now, in a sense, the game +that we're going to play all + +around this class is +to be looking for-- + +are we in this situation where +whatever is the relationship + +between income today and income +tomorrow crosses the + +45-degree line from below. + +Or are we not in +this situation. + +And now we are in a much better +position to ask the + +question that Zach asked at the +beginning of the question + +which is, are we really +believing that there could be + +a poverty trap based on food? + +I didn't want to answer his +question to start with because + +I needed some time to specify +the question in a much more + +precise way. + +Now we can re-ask the question +and say, is it really possible + +that the relationship between +the calories I consume and my + +strength has this specific form +where it intersects the + +45-degree line from below? + +And how does that intersect with +the fact that I choose + +how much to consume? + +Because, of course, if there +is indeed a strong + +relationship between the +calories consumed and the work + +capacity, then people should +try and get out of it by + +eating as much as possible +when they are very poor. + +So to the extent that people +can choose how much to + +consume, how much food to eat, +they should eat more when they + +are very poor in order to try +and pull themselves to the + +right of this point. + +And when they are richer then +it wouldn't really matter. + +So they would eat less. + +So that would create a force +that goes against an S-shape + +for the capacity curve. + +So we have to see-- + +and that goes back to +your question, where + +do you get it from? + +Well, we get it from looking at +the data and looking at-- + +to what extent people who have +more money eat so much more, + +and to what extent people who +eat so much more are so much + +more productive. + +And that's what we +are going to do. + +We are going to do +it for food. + +But now that we understand the +principle for food, we are + +going to do it for education. + +We are going to do it for +health, we are going to do it + +for savings, for businesses, +et cetera. + +Yeah? + +AUDIENCE: To go back to the +example with the start of the + +class, would you say that-- + +I forgot his name but-- that +the man was at an unstable + +equilibrium since as soon as he +lost his job, he seemed to + +go down and not be able +to eat enough to get + +another job, et cetera? + +PROFESSOR: Right. + +So that's a very +good question. + +What we can try now is to +re-interpret Mister Solhin's + +story in the context of this. + +And you could say, well perhaps, +it was exactly + +something like that. + +So what would have +happened to him? + +Let's see, I want to-- + +oops. + +What would have happened +to him? + +So we discussed that one thing +that might have happened to + +him is that something happened +to the capacity curve, right? + +We were saying that coincident +decrease in the wage and + +increase in the food prices +means that the capacity curve + +tends to move to +the southwest. + +So assume that Pak Solhin +was at the high + +equilibrium up there. + +Right? + +But right there. + +And then the curve moves +slightly to the right. + +Then, with the same income, he +suddenly is now below what + +would correspond to the new +equilibrium and it would start + +falling down, down, +down, down. + +And once he starts going down, +there is no going up again. + +It could also have +eliminated-- + +we might also be in a situation +where, at the + +beginning there was just +one equilibrium-- + +so we were, for example +in this situation-- + +and then once the curve moves +down, they are now two + +equilibria, including +the unstable one. + +So we may have started, in the +former situation, where people + +were productive enough that they +were always moving up. + +And then, with the increase in +food prices and the decrease + +in wages, that curve shifts down +and now it creates two + +equilibria. + +So some people get trapped +like he was. + +What was interesting in Pak +Solhin's villages is that, in + +the same villages, I +met people who were + +happily eating enough. + +So it seemed that there was both +kinds, which makes you + +think that these two things +were coexisting. + +So maybe what happened with him +is that we started from a + +situation like that, and then +we moved left and we end up + +with this double situation. + +That's possible + +So what we had in the +Sachs-Jolie video is-- + +we said when we just +started the class-- + +lots of examples of +poverty traps. + +And in each case, we could try +and think, well, what makes us + +think that there is indeed a +poverty trap in this case? + +Or what makes us think that +maybe there is no poverty trap + +in this case? + +So one example is what +happened with the + +farmer that they meet. + +So they claim that there +was a poverty trap. + +So what is the implicit argument +that they had in mind + +that would help us think that, +for a farmer, the decision to + +use fertilizer corresponds +to that + +problem versus that problem? + +What do we need to know about +fertilizer and fertilizer use + +to try and sort out whether we +are in the situation that they + +talk about or in the +other situation. + +Yeah? + +You go ahead, I have +a problem. + +AUDIENCE: You need to know if +there is some minimum of + +fertilizer used that becomes +useful for the farmer. + +PROFESSOR: Right. + +So there could be that, minimum +fertilizer used. + +But why would there be a minimum +fertilizer used? + +Yeah? + +AUDIENCE: Maybe it's super +difficult to acquire small + +quantities of fertilizer. + +PROFESSOR: So for example, +it might be sold by + +the bag or 50 kg. + +So in that case, what we have +is not so much S-shaped but + +something which is a degenerated +S where you get + +nothing if you can't invest +enough and then you get the + +return which are, potentially, +very steep at the beginning. + +So instead of a nice little +curvy S, we have a flat part + +and then an inverted L. + +But if we have a flat part and +then the inverted L, it would + +still work like an S. Because +there would still be an + +intersection where the curve +intersects from above on the + +flat part, an intersection where +it intersects from below + +at the beginning of the +L-shape, and another + +intersection where it intersects +from above at the + +end of the L-shape. + +So the S doesn't have to be a +proper S. It could be a flat + +part and then an inverted L. So +this example could be one, + +which is you can only buy +fertilizer by the 50 kg. + +What other situation +could we find? + +Yeah? + +AUDIENCE: The percentage of +chance for success in using + +fertilizer. + +So if you only had [INAUDIBLE] +over a small plot of land, it + +is, like, 20% chance +of actually + +improving your crop yield. + +You would have to use a larger +quantity to actually get an + +improved crop yield. + +PROFESSOR: So that could be a +possibility if the chance of + +success depends on +how much you use. + +I think it's not very likely +that it would be a purely + +physical thing because +fertilizer is quite scalable. + +But one way in which we could +have your story is if, to use + +fertilizer it requires +some learning. + +And there's no point doing +all that learning-- + +and asking all of your neighbors +how they do it, and + +try to understand +how they do it. + +Maybe experiment a little bit, +maybe it won't work first. + +--Maybe there is no point to +go through all of this + +learning if, at the end of the +day, you know that, no matter + +what, you will always be able +to use just a little bit. + +So that would be one way +in which you would, + +again, create this. + +You're not going to use any +fertilizer if you know that + +you, eventually, would be able +to use it on the substantial + +part of your field. + +Yeah? + +AUDIENCE: I think that the main +point they made in the + +video is that there needed +to be an initial push. + +So they needed a lot of +fertilizer and you needed to + +put it on all of the crops for +it to make a big impact. + +And the fact is, if you have a +little bit of fertilizer-- the + +point was why couldn't +they invest? + +So save would be paying for a +little bit of fertilizer. + +And then buy more fertilizer and +then continue to grow it + +until [INAUDIBLE]. + +You know, if you started off +with a small amount, you + +couldn't really invest +and grow your yield + +to make more money. + +PROFESSOR: Right. + +Then the third possibility is +that if you invest just a + +little bit-- + +let's say fertilizer scales +nicely, so you can invest just + +a little bit and +you can do it. + +But then, you're going to make +just a little bit more money. + +And then we need some other +mechanism which means that + +saving a little bit more money +is not feasible, or people are + +not going to do it. + +So then we need to bring in +something else which is along + +the line of what we +were discussing + +earlier in the class. + +We need to bring in something +else which is, the banks are + +not going to take your small +amount of money. + +Or if you have a small amount +of money, you are + +going to waste it. + +But if you have a lot, now +that's enough money to be + +worthwhile and you're +going to keep it. + +All right. + +So we are going to end +here for today. + +So make sure you understand this +because we are not ready + +to go back to it formally a lot, +but this is going to be + +with us all the time. + +And on Tuesday, we are going +to go through experiments. \ No newline at end of file diff --git a/84LF3ze7Yvw.txt b/84LF3ze7Yvw.txt new file mode 100644 index 0000000000000000000000000000000000000000..fea06c2884ecb4a5198f7af189f6f0342e198993 --- /dev/null +++ b/84LF3ze7Yvw.txt @@ -0,0 +1,9707 @@ +align:start position:0% + +so today my plan is to finish the open + + align:start position:0% +so today my plan is to finish the open + + + align:start position:0% +so today my plan is to finish the open +economy part of the course and uh we + + align:start position:0% +economy part of the course and uh we + + + align:start position:0% +economy part of the course and uh we +will talk about exchange regimes but but + + align:start position:0% +will talk about exchange regimes but but + + + align:start position:0% +will talk about exchange regimes but but +before I do that I need to + + align:start position:0% +before I do that I need to + + + align:start position:0% +before I do that I need to +finish er a few things that we didn't in + + align:start position:0% +finish er a few things that we didn't in + + + align:start position:0% +finish er a few things that we didn't in +previous lecture and that will help us + + align:start position:0% +previous lecture and that will help us + + + align:start position:0% +previous lecture and that will help us +an introduction for the kind of things I + + align:start position:0% +an introduction for the kind of things I + + + align:start position:0% +an introduction for the kind of things I +want to talk about today and uh let me + + align:start position:0% +want to talk about today and uh let me + + + align:start position:0% +want to talk about today and uh let me +start just reviewing that last H slide + + align:start position:0% +start just reviewing that last H slide + + + align:start position:0% +start just reviewing that last H slide +that we discussed H which is the Mandel + + align:start position:0% +that we discussed H which is the Mandel + + + align:start position:0% +that we discussed H which is the Mandel +flaming model and the Mandel flaming + + align:start position:0% +flaming model and the Mandel flaming + + + align:start position:0% +flaming model and the Mandel flaming +model essentially is our old islm model + + align:start position:0% +model essentially is our old islm model + + + align:start position:0% +model essentially is our old islm model +in which the as is a little different + + align:start position:0% +in which the as is a little different + + + align:start position:0% +in which the as is a little different +because now we have a net exports term H + + align:start position:0% +because now we have a net exports term H + + + align:start position:0% +because now we have a net exports term H +which is a function of new things like + + align:start position:0% +which is a function of new things like + + + align:start position:0% +which is a function of new things like +foreign output foreign income and the + + align:start position:0% +foreign output foreign income and the + + + align:start position:0% +foreign output foreign income and the +and most importantly the real exchange + + align:start position:0% +and most importantly the real exchange + + + align:start position:0% +and most importantly the real exchange +rate and the real Exchange in itself + + align:start position:0% +rate and the real Exchange in itself + + + align:start position:0% +rate and the real Exchange in itself +because of the uip and coverity + + align:start position:0% +because of the uip and coverity + + + align:start position:0% +because of the uip and coverity +condition is a function of expected + + align:start position:0% +condition is a function of expected + + + align:start position:0% +condition is a function of expected +exchange rate the the intern foreign + + align:start position:0% +exchange rate the the intern foreign + + + align:start position:0% +exchange rate the the intern foreign +interest rate and it also gives yet + + align:start position:0% +interest rate and it also gives yet + + + align:start position:0% +interest rate and it also gives yet +another reason for why H the interest + + align:start position:0% +another reason for why H the interest + + + align:start position:0% +another reason for why H the interest +rate affects H domestic aggregate demand + + align:start position:0% +rate affects H domestic aggregate demand + + + align:start position:0% +rate affects H domestic aggregate demand +okay there's a there a there's a the + + align:start position:0% +okay there's a there a there's a the + + + align:start position:0% +okay there's a there a there's a the +traditional investment effect of an + + align:start position:0% +traditional investment effect of an + + + align:start position:0% +traditional investment effect of an +increase in interest rate but we also + + align:start position:0% +increase in interest rate but we also + + + align:start position:0% +increase in interest rate but we also +get um the appreciation effect of an + + align:start position:0% +get um the appreciation effect of an + + + align:start position:0% +get um the appreciation effect of an +increasing the interest rate which is + + align:start position:0% +increasing the interest rate which is + + + align:start position:0% +increasing the interest rate which is +contractionary from the point of view of + + align:start position:0% +contractionary from the point of view of + + + align:start position:0% +contractionary from the point of view of +agregate demand so but this is like that + + align:start position:0% +agregate demand so but this is like that + + + align:start position:0% +agregate demand so but this is like that +with this extra net export term and and + + align:start position:0% +with this extra net export term and and + + + align:start position:0% +with this extra net export term and and +in this diagram you know for this we + + align:start position:0% +in this diagram you know for this we + + + align:start position:0% +in this diagram you know for this we +have the same interest right here from + + align:start position:0% +have the same interest right here from + + + align:start position:0% +have the same interest right here from +this diagram which which portrays the + + align:start position:0% +this diagram which which portrays the + + + align:start position:0% +this diagram which which portrays the +uncovered interest by the condition we + + align:start position:0% +uncovered interest by the condition we + + + align:start position:0% +uncovered interest by the condition we +can get for any given International + + align:start position:0% +can get for any given International + + + align:start position:0% +can get for any given International +interest rate and expected exchange rate + + align:start position:0% +interest rate and expected exchange rate + + + align:start position:0% +interest rate and expected exchange rate +for next period uh we can get the + + align:start position:0% +for next period uh we can get the + + + align:start position:0% +for next period uh we can get the +current exchange okay so that was our + + align:start position:0% +current exchange okay so that was our + + + align:start position:0% +current exchange okay so that was our +model and we did a few experiments here + + align:start position:0% +model and we did a few experiments here + + + align:start position:0% +model and we did a few experiments here +the first one was well what happens if + + align:start position:0% +the first one was well what happens if + + + align:start position:0% +the first one was well what happens if +the spected exchang rate goes up the + + align:start position:0% +the spected exchang rate goes up the + + + align:start position:0% +the spected exchang rate goes up the +first thing is which curves move well if + + align:start position:0% +first thing is which curves move well if + + + align:start position:0% +first thing is which curves move well if +the expected exchange goes up then I + + align:start position:0% +the expected exchange goes up then I + + + align:start position:0% +the expected exchange goes up then I +know that for any given interest rate H + + align:start position:0% +know that for any given interest rate H + + + align:start position:0% +know that for any given interest rate H +the current exchanger will go up okay I + + align:start position:0% +the current exchanger will go up okay I + + + align:start position:0% +the current exchanger will go up okay I +know that this curve in other words will + + align:start position:0% +know that this curve in other words will + + + align:start position:0% +know that this curve in other words will +shift to the right why do I know that + + align:start position:0% +shift to the right why do I know that + + + align:start position:0% +shift to the right why do I know that +well because if the current exchange + + align:start position:0% +well because if the current exchange + + + align:start position:0% +well because if the current exchange +rate doesn't move by the same amount of + + align:start position:0% +rate doesn't move by the same amount of + + + align:start position:0% +rate doesn't move by the same amount of +expected exchange rate now I'm going to + + align:start position:0% +expected exchange rate now I'm going to + + + align:start position:0% +expected exchange rate now I'm going to +expect I'm going to have expected + + align:start position:0% +expect I'm going to have expected + + + align:start position:0% +expect I'm going to have expected +capital gain or loss which will be + + align:start position:0% +capital gain or loss which will be + + + align:start position:0% +capital gain or loss which will be +inconsistent with the previous parity of + + align:start position:0% +inconsistent with the previous parity of + + + align:start position:0% +inconsistent with the previous parity of +interest rate no so we had agreed that + + align:start position:0% +interest rate no so we had agreed that + + + align:start position:0% +interest rate no so we had agreed that +you know that we had certain expected + + align:start position:0% +you know that we had certain expected + + + align:start position:0% +you know that we had certain expected +appreciation let's make it very simple + + align:start position:0% +appreciation let's make it very simple + + + align:start position:0% +appreciation let's make it very simple +suppose that this interest rate happens + + align:start position:0% +suppose that this interest rate happens + + + align:start position:0% +suppose that this interest rate happens +to be equal to International interest + + align:start position:0% +to be equal to International interest + + + align:start position:0% +to be equal to International interest +rate then we know that this exchange + + align:start position:0% +rate then we know that this exchange + + + align:start position:0% +rate then we know that this exchange +rate has to be equal to the expected + + align:start position:0% +rate has to be equal to the expected + + + align:start position:0% +rate has to be equal to the expected +exchange rate because you cannot expect + + align:start position:0% +exchange rate because you cannot expect + + + align:start position:0% +exchange rate because you cannot expect +an appreciation or depreciation of the + + align:start position:0% +an appreciation or depreciation of the + + + align:start position:0% +an appreciation or depreciation of the +currency the interest rate that they + + align:start position:0% +currency the interest rate that they + + + align:start position:0% +currency the interest rate that they +same but if now the expected exchange + + align:start position:0% +same but if now the expected exchange + + + align:start position:0% +same but if now the expected exchange +Next Period goes up and it exchange rate + + align:start position:0% +Next Period goes up and it exchange rate + + + align:start position:0% +Next Period goes up and it exchange rate +today doesn't move that would mean that + + align:start position:0% +today doesn't move that would mean that + + + align:start position:0% +today doesn't move that would mean that +you expect also capital A an + + align:start position:0% +you expect also capital A an + + + align:start position:0% +you expect also capital A an +appreciation of the currency and which + + align:start position:0% +appreciation of the currency and which + + + align:start position:0% +appreciation of the currency and which +means that investing in domestic bonds + + align:start position:0% +means that investing in domestic bonds + + + align:start position:0% +means that investing in domestic bonds +would give you a higher return because + + align:start position:0% +would give you a higher return because + + + align:start position:0% +would give you a higher return because +the same interest rate plus expectation + + align:start position:0% +the same interest rate plus expectation + + + align:start position:0% +the same interest rate plus expectation +so we know that the uncovering condition + + align:start position:0% +so we know that the uncovering condition + + + align:start position:0% +so we know that the uncovering condition +will move to the right know as a result + + align:start position:0% +will move to the right know as a result + + + align:start position:0% +will move to the right know as a result +of the increase in expected exchange + + align:start position:0% +of the increase in expected exchange + + + align:start position:0% +of the increase in expected exchange +rate but that also means that any given + + align:start position:0% +rate but that also means that any given + + + align:start position:0% +rate but that also means that any given +interest rate you get a higher an an + + align:start position:0% +interest rate you get a higher an an + + + align:start position:0% +interest rate you get a higher an an +appreciated exchange relative to the + + align:start position:0% +appreciated exchange relative to the + + + align:start position:0% +appreciated exchange relative to the +previous one before the increase in the + + align:start position:0% +previous one before the increase in the + + + align:start position:0% +previous one before the increase in the +spected ex change rate which means that + + align:start position:0% +spected ex change rate which means that + + + align:start position:0% +spected ex change rate which means that +the is Will shift to the + + align:start position:0% +the is Will shift to the + + + align:start position:0% +the is Will shift to the +left so if the expected changer goes up + + align:start position:0% +left so if the expected changer goes up + + + align:start position:0% +left so if the expected changer goes up +that leads to an appreciation and that + + align:start position:0% +that leads to an appreciation and that + + + align:start position:0% +that leads to an appreciation and that +leads to contraction in aggregate + + align:start position:0% +leads to contraction in aggregate + + + align:start position:0% +leads to contraction in aggregate +demand okay + + align:start position:0% +demand okay + + + align:start position:0% +demand okay +good next experiment was well what + + align:start position:0% +good next experiment was well what + + + align:start position:0% +good next experiment was well what +happens if foreign output comes down + + align:start position:0% +happens if foreign output comes down + + + align:start position:0% +happens if foreign output comes down +well if foreign output comes down then + + align:start position:0% +well if foreign output comes down then + + + align:start position:0% +well if foreign output comes down then +that has nothing to do with the intar + + align:start position:0% +that has nothing to do with the intar + + + align:start position:0% +that has nothing to do with the intar +condition it's not doesn't show up in + + align:start position:0% +condition it's not doesn't show up in + + + align:start position:0% +condition it's not doesn't show up in +this expression but it does shift this + + align:start position:0% +this expression but it does shift this + + + align:start position:0% +this expression but it does shift this +no because it's usces our exports for + + align:start position:0% +no because it's usces our exports for + + + align:start position:0% +no because it's usces our exports for +any given level of interest rate and + + align:start position:0% +any given level of interest rate and + + + align:start position:0% +any given level of interest rate and +output and so they yes shift to the left + + align:start position:0% +output and so they yes shift to the left + + + align:start position:0% +output and so they yes shift to the left +that's contraction that's a way you + + align:start position:0% +that's contraction that's a way you + + + align:start position:0% +that's contraction that's a way you +import a recession from the rest of the + + align:start position:0% +import a recession from the rest of the + + + align:start position:0% +import a recession from the rest of the +world okay as I said before people + + align:start position:0% +world okay as I said before people + + + align:start position:0% +world okay as I said before people +around Asia and and Latin America are + + align:start position:0% +around Asia and and Latin America are + + + align:start position:0% +around Asia and and Latin America are +very very worried about the Chinese + + align:start position:0% +very very worried about the Chinese + + + align:start position:0% +very very worried about the Chinese +actually the Europeans as well because + + align:start position:0% +actually the Europeans as well because + + + align:start position:0% +actually the Europeans as well because +Germany exports a lot to China are very + + align:start position:0% +Germany exports a lot to China are very + + + align:start position:0% +Germany exports a lot to China are very +worried about contractions in China and + + align:start position:0% +worried about contractions in China and + + + align:start position:0% +worried about contractions in China and +so on because through that channel is + + align:start position:0% +so on because through that channel is + + + align:start position:0% +so on because through that channel is +contractionary as well now we're in the + + align:start position:0% +contractionary as well now we're in the + + + align:start position:0% +contractionary as well now we're in the +other part of the of the cycle because + + align:start position:0% +other part of the of the cycle because + + + align:start position:0% +other part of the of the cycle because +China is + + align:start position:0% +China is + + + align:start position:0% +China is +reopening and and that sort of gives + + align:start position:0% +reopening and and that sort of gives + + + align:start position:0% +reopening and and that sort of gives +lots of Hope to Europe and so on and and + + align:start position:0% +lots of Hope to Europe and so on and and + + + align:start position:0% +lots of Hope to Europe and so on and and +one of the reasons why the Euro has + + align:start position:0% +one of the reasons why the Euro has + + + align:start position:0% +one of the reasons why the Euro has +appreciated vaves the the dollar + + align:start position:0% +appreciated vaves the the dollar + + + align:start position:0% +appreciated vaves the the dollar +recently okay um and then the last + + align:start position:0% +recently okay um and then the last + + + align:start position:0% +recently okay um and then the last +experiment that I don't remember whether + + align:start position:0% +experiment that I don't remember whether + + + align:start position:0% +experiment that I don't remember whether +we finish or not I think I said it very + + align:start position:0% +we finish or not I think I said it very + + + align:start position:0% +we finish or not I think I said it very +quickly is well what happens if the + + align:start position:0% +quickly is well what happens if the + + + align:start position:0% +quickly is well what happens if the +international interest rate goes + + align:start position:0% +international interest rate goes + + + align:start position:0% +international interest rate goes +up what moves well the first thing that + + align:start position:0% +up what moves well the first thing that + + + align:start position:0% +up what moves well the first thing that +will move is this this was a parameter + + align:start position:0% +will move is this this was a parameter + + + align:start position:0% +will move is this this was a parameter +okay so what do I know that if I keep + + align:start position:0% +okay so what do I know that if I keep + + + align:start position:0% +okay so what do I know that if I keep +the interest rate constant and the + + align:start position:0% +the interest rate constant and the + + + align:start position:0% +the interest rate constant and the +international interest rate went up what + + align:start position:0% +international interest rate went up what + + + align:start position:0% +international interest rate went up what +has to happen to the exch and the + + align:start position:0% +has to happen to the exch and the + + + align:start position:0% +has to happen to the exch and the +spected exchange hasn't changed what has + + align:start position:0% +spected exchange hasn't changed what has + + + align:start position:0% +spected exchange hasn't changed what has +to happen to the exchanger today to be + + align:start position:0% +to happen to the exchanger today to be + + + align:start position:0% +to happen to the exchanger today to be +different between the two things the two + + align:start position:0% +different between the two things the two + + + align:start position:0% +different between the two things the two +bones so this is experiment suppose + + align:start position:0% +bones so this is experiment suppose + + + align:start position:0% +bones so this is experiment suppose +we're at any domestic interest rate we + + align:start position:0% +we're at any domestic interest rate we + + + align:start position:0% +we're at any domestic interest rate we +don't touch that now I increase + + align:start position:0% +don't touch that now I increase + + + align:start position:0% +don't touch that now I increase +International interest rate and I say + + align:start position:0% +International interest rate and I say + + + align:start position:0% +International interest rate and I say +the speed exchange rate is the same as + + align:start position:0% +the speed exchange rate is the same as + + + align:start position:0% +the speed exchange rate is the same as +it used to be what has to happen to the + + align:start position:0% +it used to be what has to happen to the + + + align:start position:0% +it used to be what has to happen to the +current exchange rate in order to be + + align:start position:0% +current exchange rate in order to be + + + align:start position:0% +current exchange rate in order to be +different between investing in the US + + align:start position:0% +different between investing in the US + + + align:start position:0% +different between investing in the US +Bond or the or the foreign + + align:start position:0% + + + + align:start position:0% + +bond exactly as to depreciate + + align:start position:0% + + + + align:start position:0% + +why that's correct but but why is that + + align:start position:0% +why that's correct but but why is that + + + align:start position:0% +why that's correct but but why is that +you need an a that the exchanger Falls + + align:start position:0% +you need an a that the exchanger Falls + + + align:start position:0% +you need an a that the exchanger Falls +today in order to restore to have the + + align:start position:0% +today in order to restore to have the + + + align:start position:0% +today in order to restore to have the +the interp condition + + align:start position:0% +the interp condition + + + align:start position:0% +the interp condition +holding okay so remember what happened + + align:start position:0% +holding okay so remember what happened + + + align:start position:0% +holding okay so remember what happened +is that you had the same interest rate + + align:start position:0% +is that you had the same interest rate + + + align:start position:0% +is that you had the same interest rate +and now the the international interest + + align:start position:0% +and now the the international interest + + + align:start position:0% +and now the the international interest +went up that means if nothing moves now + + align:start position:0% +went up that means if nothing moves now + + + align:start position:0% +went up that means if nothing moves now +you prefer you were indiffer before now + + align:start position:0% +you prefer you were indiffer before now + + + align:start position:0% +you prefer you were indiffer before now +you would prefer to invest in the + + align:start position:0% +you would prefer to invest in the + + + align:start position:0% +you would prefer to invest in the +international bond if I don't change the + + align:start position:0% +international bond if I don't change the + + + align:start position:0% +international bond if I don't change the +the US rate then I have to compensate + + align:start position:0% +the US rate then I have to compensate + + + align:start position:0% +the US rate then I have to compensate +you by some other mean the only way I + + align:start position:0% +you by some other mean the only way I + + + align:start position:0% +you by some other mean the only way I +can compensate you in this mod the only + + align:start position:0% +can compensate you in this mod the only + + + align:start position:0% +can compensate you in this mod the only +thing is endogenous is by an expected + + align:start position:0% +thing is endogenous is by an expected + + + align:start position:0% +thing is endogenous is by an expected +appreciation of the exchange rate + + align:start position:0% +appreciation of the exchange rate + + + align:start position:0% +appreciation of the exchange rate +because that would give you a capital + + align:start position:0% +because that would give you a capital + + + align:start position:0% +because that would give you a capital +gain from holding the bond the US Bond a + + align:start position:0% +gain from holding the bond the US Bond a + + + align:start position:0% +gain from holding the bond the US Bond a +currency capital gain now since expected + + align:start position:0% +currency capital gain now since expected + + + align:start position:0% +currency capital gain now since expected +change is given the only way I can give + + align:start position:0% +change is given the only way I can give + + + align:start position:0% +change is given the only way I can give +you that is depreciating the currency + + align:start position:0% +you that is depreciating the currency + + + align:start position:0% +you that is depreciating the currency +today so then you can expect an + + align:start position:0% +today so then you can expect an + + + align:start position:0% +today so then you can expect an +appreciation tomorrow from today to + + align:start position:0% +appreciation tomorrow from today to + + + align:start position:0% +appreciation tomorrow from today to +tomorrow okay that's that's the + + align:start position:0% +tomorrow okay that's that's the + + + align:start position:0% +tomorrow okay that's that's the +mechanism okay so that means that this + + align:start position:0% +mechanism okay so that means that this + + + align:start position:0% +mechanism okay so that means that this +curve here will shift to the right okay + + align:start position:0% +curve here will shift to the right okay + + + align:start position:0% +curve here will shift to the right okay +for any given interest rate you need a + + align:start position:0% +for any given interest rate you need a + + + align:start position:0% +for any given interest rate you need a +sorry to the left for any given I made + + align:start position:0% +sorry to the left for any given I made + + + align:start position:0% +sorry to the left for any given I made +that mistake in the previous lecture so + + align:start position:0% +that mistake in the previous lecture so + + + align:start position:0% +that mistake in the previous lecture so +for any given interest rate this Curve + + align:start position:0% +for any given interest rate this Curve + + + align:start position:0% +for any given interest rate this Curve +will have to move to the left okay so if + + align:start position:0% +will have to move to the left okay so if + + + align:start position:0% +will have to move to the left okay so if +the interest rate doesn't change and + + align:start position:0% +the interest rate doesn't change and + + + align:start position:0% +the interest rate doesn't change and +international interest is up you need an + + align:start position:0% +international interest is up you need an + + + align:start position:0% +international interest is up you need an +exchange rate today that is lower than + + align:start position:0% +exchange rate today that is lower than + + + align:start position:0% +exchange rate today that is lower than +it used to be so you can expect an + + align:start position:0% +it used to be so you can expect an + + + align:start position:0% +it used to be so you can expect an +appreciation from now to the next period + + align:start position:0% +appreciation from now to the next period + + + align:start position:0% +appreciation from now to the next period +okay so that's what moves to the left + + align:start position:0% +okay so that's what moves to the left + + + align:start position:0% +okay so that's what moves to the left +now what happens what else moves in that + + align:start position:0% + + + + align:start position:0% + +case and remember when I I'm asking the + + align:start position:0% +case and remember when I I'm asking the + + + align:start position:0% +case and remember when I I'm asking the +question what else + + align:start position:0% +question what else + + + align:start position:0% +question what else +moves I mean what curve moves what you + + align:start position:0% +moves I mean what curve moves what you + + + align:start position:0% +moves I mean what curve moves what you +need to do is just take something as + + align:start position:0% +need to do is just take something as + + + align:start position:0% +need to do is just take something as +given and then see what whether we get + + align:start position:0% +given and then see what whether we get + + + align:start position:0% +given and then see what whether we get +the same equilibrium output or not so + + align:start position:0% +the same equilibrium output or not so + + + align:start position:0% +the same equilibrium output or not so +take an interest r as given that's the + + align:start position:0% +take an interest r as given that's the + + + align:start position:0% +take an interest r as given that's the +easiest and then ask the question well + + align:start position:0% +easiest and then ask the question well + + + align:start position:0% +easiest and then ask the question well +will I get the same equilibrium output + + align:start position:0% +will I get the same equilibrium output + + + align:start position:0% +will I get the same equilibrium output +or not if I get the same equilibrium + + align:start position:0% +or not if I get the same equilibrium + + + align:start position:0% +or not if I get the same equilibrium +output that means that yes hasn't move + + align:start position:0% +output that means that yes hasn't move + + + align:start position:0% +output that means that yes hasn't move +but if I get a different equilibrium + + align:start position:0% +but if I get a different equilibrium + + + align:start position:0% +but if I get a different equilibrium +output it means that yes has move + + align:start position:0% +output it means that yes has move + + + align:start position:0% +output it means that yes has move +because for the same interest rate I'm + + align:start position:0% +because for the same interest rate I'm + + + align:start position:0% +because for the same interest rate I'm +getting a different equilibrium output + + align:start position:0% +getting a different equilibrium output + + + align:start position:0% +getting a different equilibrium output +so what happens in this + + align:start position:0% + + + + align:start position:0% + +case does say yes move or + + align:start position:0% +case does say yes move or + + + align:start position:0% +case does say yes move or +not when I star goes up + + align:start position:0% + + + + align:start position:0% + +going to simplify the question yes it + + align:start position:0% +going to simplify the question yes it + + + align:start position:0% +going to simplify the question yes it +does which + + align:start position:0% + + + + align:start position:0% + +way will I get more or less output when + + align:start position:0% +way will I get more or less output when + + + align:start position:0% +way will I get more or less output when +the international interest rate goes up + + align:start position:0% +the international interest rate goes up + + + align:start position:0% +the international interest rate goes up +and I'm taking look the kind of things + + align:start position:0% +and I'm taking look the kind of things + + + align:start position:0% +and I'm taking look the kind of things +I'm taking as even I'm also taking as + + align:start position:0% +I'm taking as even I'm also taking as + + + align:start position:0% +I'm taking as even I'm also taking as +given International output so I I'm not + + align:start position:0% +given International output so I I'm not + + + align:start position:0% +given International output so I I'm not +do y star I'm not not moving expected + + align:start position:0% +do y star I'm not not moving expected + + + align:start position:0% +do y star I'm not not moving expected +exchange rate ER and I'm asking the + + align:start position:0% +exchange rate ER and I'm asking the + + + align:start position:0% +exchange rate ER and I'm asking the +question if the domestic Central Bank + + align:start position:0% +question if the domestic Central Bank + + + align:start position:0% +question if the domestic Central Bank +the FED in the case of the US does not + + align:start position:0% +the FED in the case of the US does not + + + align:start position:0% +the FED in the case of the US does not +change the interest rate what happens to + + align:start position:0% +change the interest rate what happens to + + + align:start position:0% +change the interest rate what happens to +gum output does it go down or + + align:start position:0% +gum output does it go down or + + + align:start position:0% +gum output does it go down or +up if they other if the international + + align:start position:0% +up if they other if the international + + + align:start position:0% +up if they other if the international +interest rate goes up the domestic + + align:start position:0% +interest rate goes up the domestic + + + align:start position:0% +interest rate goes up the domestic +interest does not what has to happen to + + align:start position:0% +interest does not what has to happen to + + + align:start position:0% +interest does not what has to happen to +the exchange + + align:start position:0% + + + + align:start position:0% + +rate you answer it before has to go down + + align:start position:0% +rate you answer it before has to go down + + + align:start position:0% +rate you answer it before has to go down +that means it has to depreciate what + + align:start position:0% +that means it has to depreciate what + + + align:start position:0% +that means it has to depreciate what +happen to net exports when the exchange + + align:start position:0% +happen to net exports when the exchange + + + align:start position:0% +happen to net exports when the exchange +rate + + align:start position:0% + + + + align:start position:0% + +depreciates what does it mean that + + align:start position:0% +depreciates what does it mean that + + + align:start position:0% +depreciates what does it mean that +exchanger depreciate especially if we + + align:start position:0% +exchanger depreciate especially if we + + + align:start position:0% +exchanger depreciate especially if we +have the in this case we have the price + + align:start position:0% +have the in this case we have the price + + + align:start position:0% +have the in this case we have the price +is completely fixed so now if the + + align:start position:0% +is completely fixed so now if the + + + align:start position:0% +is completely fixed so now if the +nominal exchanger depreciates means that + + align:start position:0% +nominal exchanger depreciates means that + + + align:start position:0% +nominal exchanger depreciates means that +the real exchanger depreciates what does + + align:start position:0% +the real exchanger depreciates what does + + + align:start position:0% +the real exchanger depreciates what does +that + + align:start position:0% + + + + align:start position:0% + +mean what got + + align:start position:0% + + + + align:start position:0% + +cheaper okay you need lot to study for + + align:start position:0% +cheaper okay you need lot to study for + + + align:start position:0% +cheaper okay you need lot to study for +the quiz and + + align:start position:0% +the quiz and + + + align:start position:0% +the quiz and +domestic goods are cheaper so so that + + align:start position:0% +domestic goods are cheaper so so that + + + align:start position:0% +domestic goods are cheaper so so that +means that the and equivalently foreign + + align:start position:0% +means that the and equivalently foreign + + + align:start position:0% +means that the and equivalently foreign +Goods got more expensive that means for + + align:start position:0% +Goods got more expensive that means for + + + align:start position:0% +Goods got more expensive that means for +any given level of domestic interest + + align:start position:0% +any given level of domestic interest + + + align:start position:0% +any given level of domestic interest +rate now there will be less Imports and + + align:start position:0% +rate now there will be less Imports and + + + align:start position:0% +rate now there will be less Imports and +More exports that means net export will + + align:start position:0% +More exports that means net export will + + + align:start position:0% +More exports that means net export will +be more which means the is Will shift to + + align:start position:0% +be more which means the is Will shift to + + + align:start position:0% +be more which means the is Will shift to +the right + + align:start position:0% + + + + align:start position:0% + +okay good so these things you you need + + align:start position:0% +okay good so these things you you need + + + align:start position:0% +okay good so these things you you need +to control I understand that it's a + + align:start position:0% +to control I understand that it's a + + + align:start position:0% +to control I understand that it's a +little confusing to think about exchange + + align:start position:0% +little confusing to think about exchange + + + align:start position:0% +little confusing to think about exchange +rates and so on but but + + align:start position:0% + + + + align:start position:0% + +um so anything that happens here with + + align:start position:0% +um so anything that happens here with + + + align:start position:0% +um so anything that happens here with +the exchange that is just a relative + + align:start position:0% +the exchange that is just a relative + + + align:start position:0% +the exchange that is just a relative +price the more expensive are your goods + + align:start position:0% +price the more expensive are your goods + + + align:start position:0% +price the more expensive are your goods +the harder it will be to sell them you + + align:start position:0% +the harder it will be to sell them you + + + align:start position:0% +the harder it will be to sell them you +and and the more tempted you will be to + + align:start position:0% +and and the more tempted you will be to + + + align:start position:0% +and and the more tempted you will be to +buy foreign Goods that's that's that's + + align:start position:0% +buy foreign Goods that's that's that's + + + align:start position:0% +buy foreign Goods that's that's that's +what it does it's so that's contraction + + align:start position:0% +what it does it's so that's contraction + + + align:start position:0% +what it does it's so that's contraction +appreciation are contraction here or not + + align:start position:0% +appreciation are contraction here or not + + + align:start position:0% +appreciation are contraction here or not +here the story is a little different + + align:start position:0% +here the story is a little different + + + align:start position:0% +here the story is a little different +it's all about equalizing expected + + align:start position:0% +it's all about equalizing expected + + + align:start position:0% +it's all about equalizing expected +returns so you need to have an movement + + align:start position:0% +returns so you need to have an movement + + + align:start position:0% +returns so you need to have an movement +in the chain rate today so that you are + + align:start position:0% +in the chain rate today so that you are + + + align:start position:0% +in the chain rate today so that you are +always indiff between investing in one + + align:start position:0% +always indiff between investing in one + + + align:start position:0% +always indiff between investing in one +side or the other it's about the return + + align:start position:0% +side or the other it's about the return + + + align:start position:0% +side or the other it's about the return +the expected exchange and the exchange + + align:start position:0% +the expected exchange and the exchange + + + align:start position:0% +the expected exchange and the exchange +rate so okay + + align:start position:0% + + + + align:start position:0% + +good okay I got it's a little unclear + + align:start position:0% +good okay I got it's a little unclear + + + align:start position:0% +good okay I got it's a little unclear +but we'll keep + + align:start position:0% + + + + align:start position:0% + +trying is there anything particularly + + align:start position:0% +trying is there anything particularly + + + align:start position:0% +trying is there anything particularly +unclear oh it's all a blur here + + align:start position:0% +unclear oh it's all a blur here + + + align:start position:0% +unclear oh it's all a blur here +okay got + + align:start position:0% +okay got + + + align:start position:0% +okay got +it + + align:start position:0% +it + + + align:start position:0% +it +um well let me so all that I describe + + align:start position:0% +um well let me so all that I describe + + + align:start position:0% +um well let me so all that I describe +here is is + + align:start position:0% +here is is + + + align:start position:0% +here is is +um is allowing the exchanger to move + + align:start position:0% +um is allowing the exchanger to move + + + align:start position:0% +um is allowing the exchanger to move +we're saying look if we move something + + align:start position:0% +we're saying look if we move something + + + align:start position:0% +we're saying look if we move something +or the foreign foreigners move something + + align:start position:0% +or the foreign foreigners move something + + + align:start position:0% +or the foreign foreigners move something +then we ask the question well what does + + align:start position:0% +then we ask the question well what does + + + align:start position:0% +then we ask the question well what does +exchange it has to do today here okay + + align:start position:0% +exchange it has to do today here okay + + + align:start position:0% +exchange it has to do today here okay +and typically when when when that's done + + align:start position:0% +and typically when when when that's done + + + align:start position:0% +and typically when when when that's done +we call those regimes floating exchange + + align:start position:0% +we call those regimes floating exchange + + + align:start position:0% +we call those regimes floating exchange +rate systems meaning exchange rate can + + align:start position:0% +rate systems meaning exchange rate can + + + align:start position:0% +rate systems meaning exchange rate can +float that move around as interest rates + + align:start position:0% +float that move around as interest rates + + + align:start position:0% +float that move around as interest rates +in different parts of the world change + + align:start position:0% +in different parts of the world change + + + align:start position:0% +in different parts of the world change +then the exchange rate moves around okay + + align:start position:0% +then the exchange rate moves around okay + + + align:start position:0% +then the exchange rate moves around okay +typically call that flexible exchange + + align:start position:0% +typically call that flexible exchange + + + align:start position:0% +typically call that flexible exchange +rate I think the distinction is a lot + + align:start position:0% +rate I think the distinction is a lot + + + align:start position:0% +rate I think the distinction is a lot +harder to make in practice but for + + align:start position:0% +harder to make in practice but for + + + align:start position:0% +harder to make in practice but for +reasons I'll explain later but but + + align:start position:0% +reasons I'll explain later but but + + + align:start position:0% +reasons I'll explain later but but +that's what is meant as a as a floating + + align:start position:0% +that's what is meant as a as a floating + + + align:start position:0% +that's what is meant as a as a floating +exchange rate system one in which really + + align:start position:0% +exchange rate system one in which really + + + align:start position:0% +exchange rate system one in which really +you're doing your each country is doing + + align:start position:0% +you're doing your each country is doing + + + align:start position:0% +you're doing your each country is doing +its own policies and so on and the + + align:start position:0% +its own policies and so on and the + + + align:start position:0% +its own policies and so on and the +exchange it does what needs to do so so + + align:start position:0% +exchange it does what needs to do so so + + + align:start position:0% +exchange it does what needs to do so so +so the financial markets + + align:start position:0% +so the financial markets + + + align:start position:0% +so the financial markets +clear many countries however do + + align:start position:0% +clear many countries however do + + + align:start position:0% +clear many countries however do +something which is the polar opposite of + + align:start position:0% +something which is the polar opposite of + + + align:start position:0% +something which is the polar opposite of +that which is called a fixed exchange + + align:start position:0% +that which is called a fixed exchange + + + align:start position:0% +that which is called a fixed exchange +rate regime okay so some countries + + align:start position:0% +rate regime okay so some countries + + + align:start position:0% +rate regime okay so some countries +really Peg their currencies to a major + + align:start position:0% +really Peg their currencies to a major + + + align:start position:0% +really Peg their currencies to a major +currency an extreme case is the Euro + + align:start position:0% +currency an extreme case is the Euro + + + align:start position:0% +currency an extreme case is the Euro +Zone where they give up their individual + + align:start position:0% +Zone where they give up their individual + + + align:start position:0% +Zone where they give up their individual +currencies and they have a common + + align:start position:0% +currencies and they have a common + + + align:start position:0% +currencies and they have a common +currency okay so so Germany and and and + + align:start position:0% +currency okay so so Germany and and and + + + align:start position:0% +currency okay so so Germany and and and +and and and Italy have a Ultra Peg + + align:start position:0% +and and and Italy have a Ultra Peg + + + align:start position:0% +and and and Italy have a Ultra Peg +exchange rate because they have the same + + align:start position:0% +exchange rate because they have the same + + + align:start position:0% +exchange rate because they have the same +currency okay now most of the times + + align:start position:0% +currency okay now most of the times + + + align:start position:0% +currency okay now most of the times +fixed exchange rates are are are a + + align:start position:0% +fixed exchange rates are are are a + + + align:start position:0% +fixed exchange rates are are are a +little weaker than that for example the + + align:start position:0% +little weaker than that for example the + + + align:start position:0% +little weaker than that for example the +Hong Kong dollar has been ped to the + + align:start position:0% +Hong Kong dollar has been ped to the + + + align:start position:0% +Hong Kong dollar has been ped to the +dollar for a long time for the US dollar + + align:start position:0% +dollar for a long time for the US dollar + + + align:start position:0% +dollar for a long time for the US dollar +for a long time okay and I'll show you a + + align:start position:0% +for a long time okay and I'll show you a + + + align:start position:0% +for a long time okay and I'll show you a +few others many countries go through + + align:start position:0% +few others many countries go through + + + align:start position:0% +few others many countries go through +some phase where they try to pay the + + align:start position:0% +some phase where they try to pay the + + + align:start position:0% +some phase where they try to pay the +currency and it typically fails at some + + align:start position:0% +currency and it typically fails at some + + + align:start position:0% +currency and it typically fails at some +point but but they have periods in which + + align:start position:0% +point but but they have periods in which + + + align:start position:0% +point but but they have periods in which +the currency is is big but so let me + + align:start position:0% +the currency is is big but so let me + + + align:start position:0% +the currency is is big but so let me +suppose that you have a peg exchange + + align:start position:0% +suppose that you have a peg exchange + + + align:start position:0% +suppose that you have a peg exchange +rate let me show you some features of it + + align:start position:0% +rate let me show you some features of it + + + align:start position:0% +rate let me show you some features of it +suppose you are in a peg in a peg or a + + align:start position:0% +suppose you are in a peg in a peg or a + + + align:start position:0% +suppose you are in a peg in a peg or a +fixed exchanges regime P to another + + align:start position:0% +fixed exchanges regime P to another + + + align:start position:0% +fixed exchanges regime P to another +currency and suppose it's credible + + align:start position:0% +currency and suppose it's credible + + + align:start position:0% +currency and suppose it's credible +that's a big issue with fixed exchange + + align:start position:0% +that's a big issue with fixed exchange + + + align:start position:0% +that's a big issue with fixed exchange +rate but suppose it's credible there are + + align:start position:0% +rate but suppose it's credible there are + + + align:start position:0% +rate but suppose it's credible there are +some countries that have credible fixed + + align:start position:0% +some countries that have credible fixed + + + align:start position:0% +some countries that have credible fixed +exchange rate well if if you have a + + align:start position:0% +exchange rate well if if you have a + + + align:start position:0% +exchange rate well if if you have a +fixed exchange rate with respect to some + + align:start position:0% +fixed exchange rate with respect to some + + + align:start position:0% +fixed exchange rate with respect to some +other Cur currency and it's credible + + align:start position:0% +other Cur currency and it's credible + + + align:start position:0% +other Cur currency and it's credible +then you know that speced exchang it is + + align:start position:0% +then you know that speced exchang it is + + + align:start position:0% +then you know that speced exchang it is +equal to exchang and equal to a constant + + align:start position:0% +equal to exchang and equal to a constant + + + align:start position:0% +equal to exchang and equal to a constant +that's what it means to have a fixed + + align:start position:0% +that's what it means to have a fixed + + + align:start position:0% +that's what it means to have a fixed +exchange rate okay it's + + align:start position:0% +exchange rate okay it's + + + align:start position:0% +exchange rate okay it's +constant but if this is constant means + + align:start position:0% +constant but if this is constant means + + + align:start position:0% +constant but if this is constant means +you never can expect an appreciation or + + align:start position:0% +you never can expect an appreciation or + + + align:start position:0% +you never can expect an appreciation or +depreciation because it's constant it's + + align:start position:0% +depreciation because it's constant it's + + + align:start position:0% +depreciation because it's constant it's +fixed and if you can't expect an + + align:start position:0% +fixed and if you can't expect an + + + align:start position:0% +fixed and if you can't expect an +appreciation or appreciation the UN + + align:start position:0% +appreciation or appreciation the UN + + + align:start position:0% +appreciation or appreciation the UN +coverage disparity condition tells you + + align:start position:0% +coverage disparity condition tells you + + + align:start position:0% +coverage disparity condition tells you +that you know what does it tell you that + + align:start position:0% +that you know what does it tell you that + + + align:start position:0% +that you know what does it tell you that +your interest rate has to be the same as + + align:start position:0% +your interest rate has to be the same as + + + align:start position:0% +your interest rate has to be the same as +the foreign interest + + align:start position:0% + + + + align:start position:0% + +rate + + align:start position:0% +rate + + + align:start position:0% +rate +why what would happen in a + + align:start position:0% +why what would happen in a + + + align:start position:0% +why what would happen in a +credible pay in a credible fixed + + align:start position:0% +credible pay in a credible fixed + + + align:start position:0% +credible pay in a credible fixed +exchange if the domestic interest rate + + align:start position:0% +exchange if the domestic interest rate + + + align:start position:0% +exchange if the domestic interest rate +is higher than International than the + + align:start position:0% +is higher than International than the + + + align:start position:0% +is higher than International than the +currency the interest rate of the + + align:start position:0% +currency the interest rate of the + + + align:start position:0% +currency the interest rate of the +country you're paying + + align:start position:0% +country you're paying + + + align:start position:0% +country you're paying +to what would happen suppose that I'm in + + align:start position:0% +to what would happen suppose that I'm in + + + align:start position:0% +to what would happen suppose that I'm in +a fixed exchange rate and and we have + + align:start position:0% +a fixed exchange rate and and we have + + + align:start position:0% +a fixed exchange rate and and we have +the same interest rate and now I + + align:start position:0% +the same interest rate and now I + + + align:start position:0% +the same interest rate and now I +unilaterally decide to raise interest + + align:start position:0% +unilaterally decide to raise interest + + + align:start position:0% +unilaterally decide to raise interest +rates what do you think would happen + + align:start position:0% +rates what do you think would happen + + + align:start position:0% +rates what do you think would happen +with capital flows what how what would + + align:start position:0% +with capital flows what how what would + + + align:start position:0% +with capital flows what how what would +you do to your + + align:start position:0% + + + + align:start position:0% + +portfolio if the C is the change it this + + align:start position:0% +portfolio if the C is the change it this + + + align:start position:0% +portfolio if the C is the change it this +Peg and is credible it is as if they + + align:start position:0% +Peg and is credible it is as if they + + + align:start position:0% +Peg and is credible it is as if they +were issuing the same currency because + + align:start position:0% +were issuing the same currency because + + + align:start position:0% +were issuing the same currency because +it's the same it's different currency + + align:start position:0% +it's the same it's different currency + + + align:start position:0% +it's the same it's different currency +different name but it has a constant in + + align:start position:0% +different name but it has a constant in + + + align:start position:0% +different name but it has a constant in +front of it okay so it's as if it was + + align:start position:0% +front of it okay so it's as if it was + + + align:start position:0% +front of it okay so it's as if it was +issuing the same currency two bonds that + + align:start position:0% +issuing the same currency two bonds that + + + align:start position:0% +issuing the same currency two bonds that +are identical and issuing the same + + align:start position:0% +are identical and issuing the same + + + align:start position:0% +are identical and issuing the same +currency cannot be paying different + + align:start position:0% +currency cannot be paying different + + + align:start position:0% +currency cannot be paying different +interest rate because you would all + + align:start position:0% +interest rate because you would all + + + align:start position:0% +interest rate because you would all +invest all your money you know in the in + + align:start position:0% +invest all your money you know in the in + + + align:start position:0% +invest all your money you know in the in +the bond that is paying a high interest + + align:start position:0% +the bond that is paying a high interest + + + align:start position:0% +the bond that is paying a high interest +rate and that's what happens here so is + + align:start position:0% +rate and that's what happens here so is + + + align:start position:0% +rate and that's what happens here so is +mechanically what would happen is for + + align:start position:0% +mechanically what would happen is for + + + align:start position:0% +mechanically what would happen is for +some crazy reason a country has a fixed + + align:start position:0% +some crazy reason a country has a fixed + + + align:start position:0% +some crazy reason a country has a fixed +exchange credible fixed exchange decides + + align:start position:0% +exchange credible fixed exchange decides + + + align:start position:0% +exchange credible fixed exchange decides +to have an interest rate higher than the + + align:start position:0% +to have an interest rate higher than the + + + align:start position:0% +to have an interest rate higher than the +currency the the interest rate in the + + align:start position:0% +currency the the interest rate in the + + + align:start position:0% +currency the the interest rate in the +currency is is being ped to then you + + align:start position:0% +currency is is being ped to then you + + + align:start position:0% +currency is is being ped to then you +would see massive Capital flows to that + + align:start position:0% +would see massive Capital flows to that + + + align:start position:0% +would see massive Capital flows to that +country so there would be ANM almost + + align:start position:0% +country so there would be ANM almost + + + align:start position:0% +country so there would be ANM almost +pressure for an appreciation of that + + align:start position:0% +pressure for an appreciation of that + + + align:start position:0% +pressure for an appreciation of that +currency okay but but the and what the + + align:start position:0% +currency okay but but the and what the + + + align:start position:0% +currency okay but but the and what the +central bank would have to do is start + + align:start position:0% +central bank would have to do is start + + + align:start position:0% +central bank would have to do is start +buying massive amounts of the supplying + + align:start position:0% +buying massive amounts of the supplying + + + align:start position:0% +buying massive amounts of the supplying +massive amounts of his currency for + + align:start position:0% +massive amounts of his currency for + + + align:start position:0% +massive amounts of his currency for +those that want to buy it because there + + align:start position:0% +those that want to buy it because there + + + align:start position:0% +those that want to buy it because there +would an infinite demand for that + + align:start position:0% +would an infinite demand for that + + + align:start position:0% +would an infinite demand for that +okay so in practice what that means and + + align:start position:0% +okay so in practice what that means and + + + align:start position:0% +okay so in practice what that means and +and sometimes you can do that for a + + align:start position:0% +and sometimes you can do that for a + + + align:start position:0% +and sometimes you can do that for a +little while but but but but not in in a + + align:start position:0% +little while but but but but not in in a + + + align:start position:0% +little while but but but but not in in a +sustained manner so what happens in + + align:start position:0% +sustained manner so what happens in + + + align:start position:0% +sustained manner so what happens in +practice is that if you really have a a + + align:start position:0% +practice is that if you really have a a + + + align:start position:0% +practice is that if you really have a a +a a peg exchange rate and you have free + + align:start position:0% +a a peg exchange rate and you have free + + + align:start position:0% +a a peg exchange rate and you have free +Capital Mobility which is people can + + align:start position:0% +Capital Mobility which is people can + + + align:start position:0% +Capital Mobility which is people can +move in and out of your bonds China + + align:start position:0% +move in and out of your bonds China + + + align:start position:0% +move in and out of your bonds China +doesn't for example so it can allow + + align:start position:0% +doesn't for example so it can allow + + + align:start position:0% +doesn't for example so it can allow +itself to both control a little with the + + align:start position:0% +itself to both control a little with the + + + align:start position:0% +itself to both control a little with the +currency and a mean be semi semi Peg and + + align:start position:0% +currency and a mean be semi semi Peg and + + + align:start position:0% +currency and a mean be semi semi Peg and +still can move it domestic interest rate + + align:start position:0% +still can move it domestic interest rate + + + align:start position:0% +still can move it domestic interest rate +because they have Capital controls but + + align:start position:0% +because they have Capital controls but + + + align:start position:0% +because they have Capital controls but +but if you don't have Capital controls + + align:start position:0% +but if you don't have Capital controls + + + align:start position:0% +but if you don't have Capital controls +and people can move money in and out it + + align:start position:0% +and people can move money in and out it + + + align:start position:0% +and people can move money in and out it +can do portfolio investment as it + + align:start position:0% +can do portfolio investment as it + + + align:start position:0% +can do portfolio investment as it +happened with most of the advanced + + align:start position:0% +happened with most of the advanced + + + align:start position:0% +happened with most of the advanced +economies then effectively ER you you + + align:start position:0% +economies then effectively ER you you + + + align:start position:0% +economies then effectively ER you you +give up domestic monetary policy okay + + align:start position:0% +give up domestic monetary policy okay + + + align:start position:0% +give up domestic monetary policy okay +because whatever the other country does + + align:start position:0% +because whatever the other country does + + + align:start position:0% +because whatever the other country does +the country you're pegging to does you + + align:start position:0% +the country you're pegging to does you + + + align:start position:0% +the country you're pegging to does you +have to follow + + align:start position:0% +have to follow + + + align:start position:0% +have to follow +that's what it means you Peg you give up + + align:start position:0% +that's what it means you Peg you give up + + + align:start position:0% +that's what it means you Peg you give up +your domestic monetary policy if you + + align:start position:0% +your domestic monetary policy if you + + + align:start position:0% +your domestic monetary policy if you +choose to Peg to another country a + + align:start position:0% +choose to Peg to another country a + + + align:start position:0% +choose to Peg to another country a +little later I'm going to tell you why + + align:start position:0% +little later I'm going to tell you why + + + align:start position:0% +little later I'm going to tell you why +countries may choose to do that but + + align:start position:0% +countries may choose to do that but + + + align:start position:0% +countries may choose to do that but +that's what you do okay and they and cpy + + align:start position:0% +that's what you do okay and they and cpy + + + align:start position:0% +that's what you do okay and they and cpy +tells you that's what you do you're not + + align:start position:0% +tells you that's what you do you're not + + + align:start position:0% +tells you that's what you do you're not +going to be able to deviate very + + align:start position:0% +going to be able to deviate very + + + align:start position:0% +going to be able to deviate very +significantly from the interest rate + + align:start position:0% +significantly from the interest rate + + + align:start position:0% +significantly from the interest rate +that the other country is setting if you + + align:start position:0% +that the other country is setting if you + + + align:start position:0% +that the other country is setting if you +want to maintain your fixed exchange + + align:start position:0% +want to maintain your fixed exchange + + + align:start position:0% +want to maintain your fixed exchange +rate now in practice there are many + + align:start position:0% +rate now in practice there are many + + + align:start position:0% +rate now in practice there are many +hybrid regimes there there are very very + + align:start position:0% +hybrid regimes there there are very very + + + align:start position:0% +hybrid regimes there there are very very +few pure float regimes H few I mean it's + + align:start position:0% +few pure float regimes H few I mean it's + + + align:start position:0% +few pure float regimes H few I mean it's +maybe five or something like that but + + align:start position:0% +maybe five or something like that but + + + align:start position:0% +maybe five or something like that but +but but but so there all sort of degrees + + align:start position:0% +but but but so there all sort of degrees + + + align:start position:0% +but but but so there all sort of degrees +of exchanges regimes and and which are + + align:start position:0% +of exchanges regimes and and which are + + + align:start position:0% +of exchanges regimes and and which are +hybrids between fixed exchange rates and + + align:start position:0% +hybrids between fixed exchange rates and + + + align:start position:0% +hybrids between fixed exchange rates and +and fully flexible exchange rates let me + + align:start position:0% +and fully flexible exchange rates let me + + + align:start position:0% +and fully flexible exchange rates let me +show you just a few just randomly more + + align:start position:0% +show you just a few just randomly more + + + align:start position:0% +show you just a few just randomly more +less randomly selected in Bloomberg H so + + align:start position:0% +less randomly selected in Bloomberg H so + + + align:start position:0% +less randomly selected in Bloomberg H so +there you have in in in in in white is + + align:start position:0% +there you have in in in in in white is + + + align:start position:0% +there you have in in in in in white is +the US Euro that's a float that's that's + + align:start position:0% +the US Euro that's a float that's that's + + + align:start position:0% +the US Euro that's a float that's that's +the cleanest float you can imagine I + + align:start position:0% +the cleanest float you can imagine I + + + align:start position:0% +the cleanest float you can imagine I +mean there's + + align:start position:0% +mean there's + + + align:start position:0% +mean there's +no then another which is a very clean + + align:start position:0% +no then another which is a very clean + + + align:start position:0% +no then another which is a very clean +float is the dollar Yen Japanese + + align:start position:0% +float is the dollar Yen Japanese + + + align:start position:0% +float is the dollar Yen Japanese +Yen now that's a currency that has that + + align:start position:0% +Yen now that's a currency that has that + + + align:start position:0% +Yen now that's a currency that has that +freely float but if there is a major + + align:start position:0% +freely float but if there is a major + + + align:start position:0% +freely float but if there is a major +dislocation central banks do intervene + + align:start position:0% +dislocation central banks do intervene + + + align:start position:0% +dislocation central banks do intervene +to money it means in normal + + align:start position:0% +to money it means in normal + + + align:start position:0% +to money it means in normal +circumstances they float and the same is + + align:start position:0% +circumstances they float and the same is + + + align:start position:0% +circumstances they float and the same is +true with the EUR but if as big + + align:start position:0% +true with the EUR but if as big + + + align:start position:0% +true with the EUR but if as big +dislocation some major Bank collapses or + + align:start position:0% +dislocation some major Bank collapses or + + + align:start position:0% +dislocation some major Bank collapses or +something like that then there are major + + align:start position:0% +something like that then there are major + + + align:start position:0% +something like that then there are major +dis dislocations in in financial markets + + align:start position:0% +dis dislocations in in financial markets + + + align:start position:0% +dis dislocations in in financial markets +they become very segmented Arbitrage is + + align:start position:0% +they become very segmented Arbitrage is + + + align:start position:0% +they become very segmented Arbitrage is +not that easy and so on then then then + + align:start position:0% +not that easy and so on then then then + + + align:start position:0% +not that easy and so on then then then +central banks intervene but but for the + + align:start position:0% +central banks intervene but but for the + + + align:start position:0% +central banks intervene but but for the +normal business cycle and so on they do + + align:start position:0% +normal business cycle and so on they do + + + align:start position:0% +normal business cycle and so on they do +not they don't intervene in the currency + + align:start position:0% +not they don't intervene in the currency + + + align:start position:0% +not they don't intervene in the currency +Market they intervene in different ways + + align:start position:0% +Market they intervene in different ways + + + align:start position:0% +Market they intervene in different ways +and that's the reason I'll get + + align:start position:0% +and that's the reason I'll get + + + align:start position:0% +and that's the reason I'll get +there and the other one is the the pound + + align:start position:0% +there and the other one is the the pound + + + align:start position:0% +there and the other one is the the pound +no the US dollar versus the British + + align:start position:0% +no the US dollar versus the British + + + align:start position:0% +no the US dollar versus the British +pound then then it's also that's a pure + + align:start position:0% +pound then then it's also that's a pure + + + align:start position:0% +pound then then it's also that's a pure +float + + align:start position:0% +float + + + align:start position:0% +float +these are also pure floats this is the + + align:start position:0% +these are also pure floats this is the + + + align:start position:0% +these are also pure floats this is the +US versus the OC + + align:start position:0% +US versus the OC + + + align:start position:0% +US versus the OC +dollar so and against the Canadian + + align:start position:0% +dollar so and against the Canadian + + + align:start position:0% +dollar so and against the Canadian +dollar and against the the Swedish Kona + + align:start position:0% +dollar and against the the Swedish Kona + + + align:start position:0% +dollar and against the the Swedish Kona +okay those are pretty + + align:start position:0% +okay those are pretty + + + align:start position:0% +okay those are pretty +floating regimes they are a little + + align:start position:0% +floating regimes they are a little + + + align:start position:0% +floating regimes they are a little +different from the previous ones I show + + align:start position:0% +different from the previous ones I show + + + align:start position:0% +different from the previous ones I show +you because these are currencies are + + align:start position:0% +you because these are currencies are + + + align:start position:0% +you because these are currencies are +much more prone to sell off during + + align:start position:0% +much more prone to sell off during + + + align:start position:0% +much more prone to sell off during +riskof environments and that's the + + align:start position:0% +riskof environments and that's the + + + align:start position:0% +riskof environments and that's the +reason you see this spikes here okay + + align:start position:0% +reason you see this spikes here okay + + + align:start position:0% +reason you see this spikes here okay +this was Co big spike you didn't see it + + align:start position:0% +this was Co big spike you didn't see it + + + align:start position:0% +this was Co big spike you didn't see it +in the in the dollar euro and so on so + + align:start position:0% +in the in the dollar euro and so on so + + + align:start position:0% +in the in the dollar euro and so on so +forth so these are currencies that are + + align:start position:0% +forth so these are currencies that are + + + align:start position:0% +forth so these are currencies that are +free floaters but they're very exposed + + align:start position:0% +free floaters but they're very exposed + + + align:start position:0% +free floaters but they're very exposed +to to risk the risk environment in the + + align:start position:0% +to to risk the risk environment in the + + + align:start position:0% +to to risk the risk environment in the +market but there still their free + + align:start position:0% +market but there still their free + + + align:start position:0% +market but there still their free +floaters + + align:start position:0% +floaters + + + align:start position:0% +floaters +um the SS are a little bit more of + + align:start position:0% +um the SS are a little bit more of + + + align:start position:0% +um the SS are a little bit more of +independent minded and and but they do + + align:start position:0% +independent minded and and but they do + + + align:start position:0% +independent minded and and but they do +control a bit more the currency but it's + + align:start position:0% +control a bit more the currency but it's + + + align:start position:0% +control a bit more the currency but it's +still I I consider + + align:start position:0% +still I I consider + + + align:start position:0% +still I I consider +those free floaters + + align:start position:0% +those free floaters + + + align:start position:0% +those free floaters +these currencies are a little different + + align:start position:0% +these currencies are a little different + + + align:start position:0% +these currencies are a little different +this is the Brazilian + + align:start position:0% +this is the Brazilian + + + align:start position:0% +this is the Brazilian +real H the Zar is the South African Rand + + align:start position:0% +real H the Zar is the South African Rand + + + align:start position:0% +real H the Zar is the South African Rand +and this is the Colombian Peso and you + + align:start position:0% +and this is the Colombian Peso and you + + + align:start position:0% +and this is the Colombian Peso and you +see several things here they they do + + align:start position:0% +see several things here they they do + + + align:start position:0% +see several things here they they do +move so so they have a big component of + + align:start position:0% +move so so they have a big component of + + + align:start position:0% +move so so they have a big component of +flexible exchange rate uh they do + + align:start position:0% +flexible exchange rate uh they do + + + align:start position:0% +flexible exchange rate uh they do +intervene a lot more though H because + + align:start position:0% +intervene a lot more though H because + + + align:start position:0% +intervene a lot more though H because +they are exposed to much more risk off + + align:start position:0% +they are exposed to much more risk off + + + align:start position:0% +they are exposed to much more risk off +type environment and so on and they need + + align:start position:0% +type environment and so on and they need + + + align:start position:0% +type environment and so on and they need +to intervene fairly frequently to + + align:start position:0% +to intervene fairly frequently to + + + align:start position:0% +to intervene fairly frequently to +control movements in the chain rate but + + align:start position:0% +control movements in the chain rate but + + + align:start position:0% +control movements in the chain rate but +but you also see a trend in this things + + align:start position:0% +but you also see a trend in this things + + + align:start position:0% +but you also see a trend in this things +so their currencies are becoming + + align:start position:0% +so their currencies are becoming + + + align:start position:0% +so their currencies are becoming +chronically weaker relative to the + + align:start position:0% +chronically weaker relative to the + + + align:start position:0% +chronically weaker relative to the +dollar and the reason for that is + + align:start position:0% +dollar and the reason for that is + + + align:start position:0% +dollar and the reason for that is +because there are countries that have + + align:start position:0% +because there are countries that have + + + align:start position:0% +because there are countries that have +higher inflation so if you want to + + align:start position:0% +higher inflation so if you want to + + + align:start position:0% +higher inflation so if you want to +maintain the real exchange rate Conant + + align:start position:0% +maintain the real exchange rate Conant + + + align:start position:0% +maintain the real exchange rate Conant +and you have higher inflation than the + + align:start position:0% +and you have higher inflation than the + + + align:start position:0% +and you have higher inflation than the +other country then your nominal exchange + + align:start position:0% +other country then your nominal exchange + + + align:start position:0% +other country then your nominal exchange +rate has to be + + align:start position:0% +rate has to be + + + align:start position:0% +rate has to be +depreciating okay because your prices + + align:start position:0% +depreciating okay because your prices + + + align:start position:0% +depreciating okay because your prices +are rising at a faster Pace than the + + align:start position:0% +are rising at a faster Pace than the + + + align:start position:0% +are rising at a faster Pace than the +other one well if the exchanger was not + + align:start position:0% +other one well if the exchanger was not + + + align:start position:0% +other one well if the exchanger was not +appreciating on a depreciating on + + align:start position:0% +appreciating on a depreciating on + + + align:start position:0% +appreciating on a depreciating on +average then it would mean that you + + align:start position:0% +average then it would mean that you + + + align:start position:0% +average then it would mean that you +would becoming more and more expensive + + align:start position:0% +would becoming more and more expensive + + + align:start position:0% +would becoming more and more expensive +okay so that's a reason countries that + + align:start position:0% +okay so that's a reason countries that + + + align:start position:0% +okay so that's a reason countries that +have higher inflation they tend to have + + align:start position:0% +have higher inflation they tend to have + + + align:start position:0% +have higher inflation they tend to have +these Trends as well okay but it's still + + align:start position:0% +these Trends as well okay but it's still + + + align:start position:0% +these Trends as well okay but it's still +fairly + + align:start position:0% +fairly + + + align:start position:0% +fairly +floating here these are all currencies + + align:start position:0% +floating here these are all currencies + + + align:start position:0% +floating here these are all currencies +that are H to a different + + align:start position:0% +that are H to a different + + + align:start position:0% +that are H to a different +degree er um targeted in the sense + + align:start position:0% +degree er um targeted in the sense + + + align:start position:0% +degree er um targeted in the sense +they're contained in in terms of they're + + align:start position:0% +they're contained in in terms of they're + + + align:start position:0% +they're contained in in terms of they're +not free to float at will H the scale + + align:start position:0% +not free to float at will H the scale + + + align:start position:0% +not free to float at will H the scale +here will mislead you if I had put it in + + align:start position:0% +here will mislead you if I had put it in + + + align:start position:0% +here will mislead you if I had put it in +the same scale as the the euro dollar or + + align:start position:0% +the same scale as the the euro dollar or + + + align:start position:0% +the same scale as the the euro dollar or +the the Euro Yen and the the dollar Yen + + align:start position:0% +the the Euro Yen and the the dollar Yen + + + align:start position:0% +the the Euro Yen and the the dollar Yen +or the Euro Yen as well then these + + align:start position:0% +or the Euro Yen as well then these + + + align:start position:0% +or the Euro Yen as well then these +things would have been look very small + + align:start position:0% +things would have been look very small + + + align:start position:0% +things would have been look very small +okay so I should have put a real floater + + align:start position:0% +okay so I should have put a real floater + + + align:start position:0% +okay so I should have put a real floater +there so you would have seen that these + + align:start position:0% +there so you would have seen that these + + + align:start position:0% +there so you would have seen that these +guys are moving a lot less and these are + + align:start position:0% +guys are moving a lot less and these are + + + align:start position:0% +guys are moving a lot less and these are +different kind of countries this is the + + align:start position:0% +different kind of countries this is the + + + align:start position:0% +different kind of countries this is the +Hong Kong + + align:start position:0% +Hong Kong + + + align:start position:0% +Hong Kong +dollar that for all practical purposes + + align:start position:0% +dollar that for all practical purposes + + + align:start position:0% +dollar that for all practical purposes +Peg okay this little Wiggles is just + + align:start position:0% +Peg okay this little Wiggles is just + + + align:start position:0% +Peg okay this little Wiggles is just +technical things that happen overnight + + align:start position:0% +technical things that happen overnight + + + align:start position:0% +technical things that happen overnight +and stuff like that but they're Peg to + + align:start position:0% +and stuff like that but they're Peg to + + + align:start position:0% +and stuff like that but they're Peg to +the dollar okay so Hong Kong dollar is + + align:start position:0% +the dollar okay so Hong Kong dollar is + + + align:start position:0% +the dollar okay so Hong Kong dollar is +Peg to the + + align:start position:0% +Peg to the + + + align:start position:0% +Peg to the +dollar H that means they really don't + + align:start position:0% +dollar H that means they really don't + + + align:start position:0% +dollar H that means they really don't +have independent monetary policy + + align:start position:0% +have independent monetary policy + + + align:start position:0% +have independent monetary policy +relative to the US is and Le the + + align:start position:0% +relative to the US is and Le the + + + align:start position:0% +relative to the US is and Le the +US the this is a CN this is the the + + align:start position:0% +US the this is a CN this is the the + + + align:start position:0% +US the this is a CN this is the the +the the Chinese rii and and and it's a + + align:start position:0% +the the Chinese rii and and and it's a + + + align:start position:0% +the the Chinese rii and and and it's a +currency again I should have put it with + + align:start position:0% +currency again I should have put it with + + + align:start position:0% +currency again I should have put it with +a float real floater there is a lot more + + align:start position:0% +a float real floater there is a lot more + + + align:start position:0% +a float real floater there is a lot more +control okay so it moves around around + + align:start position:0% +control okay so it moves around around + + + align:start position:0% +control okay so it moves around around +but but in a much tighter range and and + + align:start position:0% +but but in a much tighter range and and + + + align:start position:0% +but but in a much tighter range and and +and they are thinking about exchange + + align:start position:0% +and they are thinking about exchange + + + align:start position:0% +and they are thinking about exchange +rate when part of their policy program + + align:start position:0% +rate when part of their policy program + + + align:start position:0% +rate when part of their policy program +and so on the exchange that is something + + align:start position:0% +and so on the exchange that is something + + + align:start position:0% +and so on the exchange that is something +they're thinking + + align:start position:0% +they're thinking + + + align:start position:0% +they're thinking +about this one here the blue one is is + + align:start position:0% +about this one here the blue one is is + + + align:start position:0% +about this one here the blue one is is +an interesting one + + align:start position:0% +an interesting one + + + align:start position:0% +an interesting one +er + + align:start position:0% +er + + + align:start position:0% +er +um that's the the the the Singaporean + + align:start position:0% +um that's the the the the Singaporean + + + align:start position:0% +um that's the the the the Singaporean +dollar okay and the Singaporean dollar + + align:start position:0% +dollar okay and the Singaporean dollar + + + align:start position:0% +dollar okay and the Singaporean dollar +they have a very interesting regime they + + align:start position:0% +they have a very interesting regime they + + + align:start position:0% +they have a very interesting regime they +have a a a um a Target Zone meaning they + + align:start position:0% +have a a a um a Target Zone meaning they + + + align:start position:0% +have a a a um a Target Zone meaning they +let the exchange rate move within a + + align:start position:0% +let the exchange rate move within a + + + align:start position:0% +let the exchange rate move within a +range + + align:start position:0% +range + + + align:start position:0% +range +only but it's not Peg against a single + + align:start position:0% +only but it's not Peg against a single + + + align:start position:0% +only but it's not Peg against a single +currency is pay against a basket of of + + align:start position:0% +currency is pay against a basket of of + + + align:start position:0% +currency is pay against a basket of of +currencies okay and the the recipe is + + align:start position:0% +currencies okay and the the recipe is + + + align:start position:0% +currencies okay and the the recipe is +secret so everyone is always guessing + + align:start position:0% +secret so everyone is always guessing + + + align:start position:0% +secret so everyone is always guessing +what they're doing and so on They do + + align:start position:0% +what they're doing and so on They do + + + align:start position:0% +what they're doing and so on They do +change the weights a little bit to keep + + align:start position:0% +change the weights a little bit to keep + + + align:start position:0% +change the weights a little bit to keep +the markets confused but but the Curren + + align:start position:0% +the markets confused but but the Curren + + + align:start position:0% +the markets confused but but the Curren +is very stable we all understand it's a + + align:start position:0% +is very stable we all understand it's a + + + align:start position:0% +is very stable we all understand it's a +it's a weighted average of the Euro the + + align:start position:0% +it's a weighted average of the Euro the + + + align:start position:0% +it's a weighted average of the Euro the +Remi and the and the dollar but but they + + align:start position:0% +Remi and the and the dollar but but they + + + align:start position:0% +Remi and the and the dollar but but they +they don't disclose exactly the thing + + align:start position:0% +they don't disclose exactly the thing + + + align:start position:0% +they don't disclose exactly the thing +but you know you can filter out what + + align:start position:0% +but you know you can filter out what + + + align:start position:0% +but you know you can filter out what +they're doing and and they they keep + + align:start position:0% +they're doing and and they they keep + + + align:start position:0% +they're doing and and they they keep +things in a range and they occasionally + + align:start position:0% +things in a range and they occasionally + + + align:start position:0% +things in a range and they occasionally +change the slope of that range but but + + align:start position:0% +change the slope of that range but but + + + align:start position:0% +change the slope of that range but but +it's very regulated in that con and they + + align:start position:0% +it's very regulated in that con and they + + + align:start position:0% +it's very regulated in that con and they +in fact they State their monetary policy + + align:start position:0% +in fact they State their monetary policy + + + align:start position:0% +in fact they State their monetary policy +in terms of the effects they said that's + + align:start position:0% +in terms of the effects they said that's + + + align:start position:0% +in terms of the effects they said that's +our policy interest rate is whatever it + + align:start position:0% +our policy interest rate is whatever it + + + align:start position:0% +our policy interest rate is whatever it +needs to be so the exchange remains in + + align:start position:0% +needs to be so the exchange remains in + + + align:start position:0% +needs to be so the exchange remains in +that range that's that's that's the way + + align:start position:0% +that range that's that's that's the way + + + align:start position:0% +that range that's that's that's the way +they State monetary don't even think + + align:start position:0% +they State monetary don't even think + + + align:start position:0% +they State monetary don't even think +about so I let the markets determine the + + align:start position:0% +about so I let the markets determine the + + + align:start position:0% +about so I let the markets determine the +interest we determine the CH here in + + align:start position:0% +interest we determine the CH here in + + + align:start position:0% +interest we determine the CH here in +that range and it's a narrow + + align:start position:0% + + + + align:start position:0% + +range again I should have + + align:start position:0% +range again I should have + + + align:start position:0% +range again I should have +put um a real floater that you would + + align:start position:0% +put um a real floater that you would + + + align:start position:0% +put um a real floater that you would +have seen that okay so Al so the point + + align:start position:0% +have seen that okay so Al so the point + + + align:start position:0% +have seen that okay so Al so the point +is that everything goes there are all + + align:start position:0% +is that everything goes there are all + + + align:start position:0% +is that everything goes there are all +sort of Arrangements happening around + + align:start position:0% +sort of Arrangements happening around + + + align:start position:0% +sort of Arrangements happening around +the world this is these are different + + align:start position:0% +the world this is these are different + + + align:start position:0% +the world this is these are different +kind of currencies no uh this is the the + + align:start position:0% +kind of currencies no uh this is the the + + + align:start position:0% +kind of currencies no uh this is the the +the the Turkish lader okay and the + + align:start position:0% +the the Turkish lader okay and the + + + align:start position:0% +the the Turkish lader okay and the +Argentinian + + align:start position:0% +Argentinian + + + align:start position:0% +Argentinian +peso I think through the sample has have + + align:start position:0% +peso I think through the sample has have + + + align:start position:0% +peso I think through the sample has have +been called peso since since they have + + align:start position:0% +been called peso since since they have + + + align:start position:0% +been called peso since since they have +this very high inflations they keep + + align:start position:0% +this very high inflations they keep + + + align:start position:0% +this very high inflations they keep +changing the name of the currency and so + + align:start position:0% +changing the name of the currency and so + + + align:start position:0% +changing the name of the currency and so +on because they have to remove zeros + + align:start position:0% +on because they have to remove zeros + + + align:start position:0% +on because they have to remove zeros +from things so but but I think through + + align:start position:0% +from things so but but I think through + + + align:start position:0% +from things so but but I think through +all that period is still the Argentinian + + align:start position:0% +all that period is still the Argentinian + + + align:start position:0% +all that period is still the Argentinian +PES and uh so I mean look at the + + align:start position:0% +PES and uh so I mean look at the + + + align:start position:0% +PES and uh so I mean look at the +scale so you cannot see it but but all + + align:start position:0% +scale so you cannot see it but but all + + + align:start position:0% +scale so you cannot see it but but all +these two countries are all the time + + align:start position:0% +these two countries are all the time + + + align:start position:0% +these two countries are all the time +fighting against the exchange rate in + + align:start position:0% +fighting against the exchange rate in + + + align:start position:0% +fighting against the exchange rate in +fact Argentina today has like five + + align:start position:0% +fact Argentina today has like five + + + align:start position:0% +fact Argentina today has like five +different exchange rates there is the + + align:start position:0% +different exchange rates there is the + + + align:start position:0% +different exchange rates there is the +official exchange rate there is the blue + + align:start position:0% +official exchange rate there is the blue + + + align:start position:0% +official exchange rate there is the blue +exchange rate there is a purple + + align:start position:0% +exchange rate there is a purple + + + align:start position:0% +exchange rate there is a purple +exchanger there all sort of things you + + align:start position:0% +exchanger there all sort of things you + + + align:start position:0% +exchanger there all sort of things you +should never pay with a credit card if + + align:start position:0% +should never pay with a credit card if + + + align:start position:0% +should never pay with a credit card if +you go to Argentina if you do tourism + + align:start position:0% +you go to Argentina if you do tourism + + + align:start position:0% +you go to Argentina if you do tourism +because you don't want to pay the + + align:start position:0% +because you don't want to pay the + + + align:start position:0% +because you don't want to pay the +official exchange you can get three + + align:start position:0% +official exchange you can get three + + + align:start position:0% +official exchange you can get three +times that in the in the blue Market I + + align:start position:0% +times that in the in the blue Market I + + + align:start position:0% +times that in the in the blue Market I +call it the black market since everyone + + align:start position:0% +call it the black market since everyone + + + align:start position:0% +call it the black market since everyone +does it I think blue is fine but but so + + align:start position:0% +does it I think blue is fine but but so + + + align:start position:0% +does it I think blue is fine but but so +there are all sort of + + align:start position:0% +there are all sort of + + + align:start position:0% +there are all sort of +exchanges and but still this is the + + align:start position:0% +exchanges and but still this is the + + + align:start position:0% +exchanges and but still this is the +official one + + align:start position:0% +official one + + + align:start position:0% +official one +and even the official one you see sort + + align:start position:0% +and even the official one you see sort + + + align:start position:0% +and even the official one you see sort +of has completely + + align:start position:0% +of has completely + + + align:start position:0% +of has completely +exploded the Turkish leader looks pretty + + align:start position:0% +exploded the Turkish leader looks pretty + + + align:start position:0% +exploded the Turkish leader looks pretty +good here just because I put it next to + + align:start position:0% +good here just because I put it next to + + + align:start position:0% +good here just because I put it next to +argentin argentinan PES otherwise it + + align:start position:0% +argentin argentinan PES otherwise it + + + align:start position:0% +argentin argentinan PES otherwise it +also would look pretty bad okay but most + + align:start position:0% +also would look pretty bad okay but most + + + align:start position:0% +also would look pretty bad okay but most +of the these countries are all the time + + align:start position:0% +of the these countries are all the time + + + align:start position:0% +of the these countries are all the time +paying the exchange rate because they + + align:start position:0% +paying the exchange rate because they + + + align:start position:0% +paying the exchange rate because they +use that to stabilize inflation the + + align:start position:0% +use that to stabilize inflation the + + + align:start position:0% +use that to stabilize inflation the +whole thing breaks up and then boom they + + align:start position:0% +whole thing breaks up and then boom they + + + align:start position:0% +whole thing breaks up and then boom they +go through big spikes you see this where + + align:start position:0% +go through big spikes you see this where + + + align:start position:0% +go through big spikes you see this where +they're trying to stabilize there you + + align:start position:0% +they're trying to stabilize there you + + + align:start position:0% +they're trying to stabilize there you +see that they're trying to stabilize the + + align:start position:0% +see that they're trying to stabilize the + + + align:start position:0% +see that they're trying to stabilize the +currency they're not floating there that + + align:start position:0% +currency they're not floating there that + + + align:start position:0% +currency they're not floating there that +range and they were a little successful + + align:start position:0% +range and they were a little successful + + + align:start position:0% +range and they were a little successful +and and and and and that happens all the + + align:start position:0% +and and and and and that happens all the + + + align:start position:0% +and and and and and that happens all the +time + + align:start position:0% +time + + + align:start position:0% +time +okay and now + + align:start position:0% +okay and now + + + align:start position:0% +okay and now +obviously I mean look at this the size + + align:start position:0% +obviously I mean look at this the size + + + align:start position:0% +obviously I mean look at this the size +of this this is an appreciation of the + + align:start position:0% +of this this is an appreciation of the + + + align:start position:0% +of this this is an appreciation of the +dollar so it's a depreciation of the + + align:start position:0% +dollar so it's a depreciation of the + + + align:start position:0% +dollar so it's a depreciation of the +Argentinian PES what do you think is + + align:start position:0% +Argentinian PES what do you think is + + + align:start position:0% +Argentinian PES what do you think is +happening + + align:start position:0% + + + + align:start position:0% + +here looks very smooth by the way it's + + align:start position:0% +here looks very smooth by the way it's + + + align:start position:0% +here looks very smooth by the way it's +not that it's moving around it's + + align:start position:0% +not that it's moving around it's + + + align:start position:0% +not that it's moving around it's +just what do you think is happening + + align:start position:0% + + + + align:start position:0% + +very high inflation the thousands and + + align:start position:0% +very high inflation the thousands and + + + align:start position:0% +very high inflation the thousands and +that's what that's what is happening + + align:start position:0% +that's what that's what is happening + + + align:start position:0% +that's what that's what is happening +here but but again this is a hybrid + + align:start position:0% +here but but again this is a hybrid + + + align:start position:0% +here but but again this is a hybrid +system they they try to stabilize + + align:start position:0% +system they they try to stabilize + + + align:start position:0% +system they they try to stabilize +frequently the exchange rate the thing + + align:start position:0% +frequently the exchange rate the thing + + + align:start position:0% +frequently the exchange rate the thing +goes and then they stabilize it again + + align:start position:0% +goes and then they stabilize it again + + + align:start position:0% +goes and then they stabilize it again +and and so on so forth but you can't + + align:start position:0% +and and so on so forth but you can't + + + align:start position:0% +and and so on so forth but you can't +fight just having much higher inflation + + align:start position:0% +fight just having much higher inflation + + + align:start position:0% +fight just having much higher inflation +than the rest of the world you have + + align:start position:0% +than the rest of the world you have + + + align:start position:0% +than the rest of the world you have +higher inflation then there's no way + + align:start position:0% +higher inflation then there's no way + + + align:start position:0% +higher inflation then there's no way +around that your currency they + + align:start position:0% +around that your currency they + + + align:start position:0% +around that your currency they +appreciate they try to but they + + align:start position:0% +appreciate they try to but they + + + align:start position:0% +appreciate they try to but they +can't anyways + + align:start position:0% +can't anyways + + + align:start position:0% +can't anyways +ER so let me let me go back to this + + align:start position:0% +ER so let me let me go back to this + + + align:start position:0% +ER so let me let me go back to this +model and and and and think a little bit + + align:start position:0% +model and and and and think a little bit + + + align:start position:0% +model and and and and think a little bit +more about the decision + + align:start position:0% +more about the decision + + + align:start position:0% +more about the decision +to have one kind of exchanger the other + + align:start position:0% +to have one kind of exchanger the other + + + align:start position:0% +to have one kind of exchanger the other +one and therefore everything that goes + + align:start position:0% +one and therefore everything that goes + + + align:start position:0% +one and therefore everything that goes +in between so remember I just to remind + + align:start position:0% +in between so remember I just to remind + + + align:start position:0% +in between so remember I just to remind +you that's that's a model we + + align:start position:0% +you that's that's a model we + + + align:start position:0% +you that's that's a model we +have um so let me think about policy + + align:start position:0% +have um so let me think about policy + + + align:start position:0% +have um so let me think about policy +first and then then let's think how how + + align:start position:0% +first and then then let's think how how + + + align:start position:0% +first and then then let's think how how +how do you deal with policy in the + + align:start position:0% +how do you deal with policy in the + + + align:start position:0% +how do you deal with policy in the +different exchanger regimes and and then + + align:start position:0% +different exchanger regimes and and then + + + align:start position:0% +different exchanger regimes and and then +we'll see why would countries would do + + align:start position:0% +we'll see why would countries would do + + + align:start position:0% +we'll see why would countries would do +one thing or other so suppose a country + + align:start position:0% +one thing or other so suppose a country + + + align:start position:0% +one thing or other so suppose a country +is in a recession we are in this + + align:start position:0% +is in a recession we are in this + + + align:start position:0% +is in a recession we are in this +Model H and suppose that we are in the + + align:start position:0% +Model H and suppose that we are in the + + + align:start position:0% +Model H and suppose that we are in the +flexible exchange regime so what should + + align:start position:0% +flexible exchange regime so what should + + + align:start position:0% +flexible exchange regime so what should +the F fiscal policy do suppose you're in + + align:start position:0% +the F fiscal policy do suppose you're in + + + align:start position:0% +the F fiscal policy do suppose you're in +a + + align:start position:0% +a + + + align:start position:0% +a +recession what what should F fiscal + + align:start position:0% +recession what what should F fiscal + + + align:start position:0% +recession what what should F fiscal +policy + + align:start position:0% + + + + align:start position:0% + +to there's nothing unique of close + + align:start position:0% +to there's nothing unique of close + + + align:start position:0% +to there's nothing unique of close +economy here in open economy in closed + + align:start position:0% +economy here in open economy in closed + + + align:start position:0% +economy here in open economy in closed +economy you would have given me the same + + align:start position:0% +economy you would have given me the same + + + align:start position:0% +economy you would have given me the same +answer if you in a recession what will + + align:start position:0% +answer if you in a recession what will + + + align:start position:0% +answer if you in a recession what will +you do with fiscal policy + + align:start position:0% +you do with fiscal policy + + + align:start position:0% +you do with fiscal policy +have expansionary fiscal policy increase + + align:start position:0% +have expansionary fiscal policy increase + + + align:start position:0% +have expansionary fiscal policy increase +G so that means you move the yes to the + + align:start position:0% +G so that means you move the yes to the + + + align:start position:0% +G so that means you move the yes to the +right nothing changes in the open + + align:start position:0% +right nothing changes in the open + + + align:start position:0% +right nothing changes in the open +economy you'll keep doing that the only + + align:start position:0% +economy you'll keep doing that the only + + + align:start position:0% +economy you'll keep doing that the only +thing that you get is a little smaller + + align:start position:0% +thing that you get is a little smaller + + + align:start position:0% +thing that you get is a little smaller +multiplier because part of that will go + + align:start position:0% +multiplier because part of that will go + + + align:start position:0% +multiplier because part of that will go +to Imports but but still it moves in the + + align:start position:0% +to Imports but but still it moves in the + + + align:start position:0% +to Imports but but still it moves in the +right direction okay and and and yes + + align:start position:0% +right direction okay and and and yes + + + align:start position:0% +right direction okay and and and yes +countries rely on other countries doing + + align:start position:0% +countries rely on other countries doing + + + align:start position:0% +countries rely on other countries doing +also their own expansionary fiscal + + align:start position:0% +also their own expansionary fiscal + + + align:start position:0% +also their own expansionary fiscal +policy but suppose we're talking about a + + align:start position:0% +policy but suppose we're talking about a + + + align:start position:0% +policy but suppose we're talking about a +recession that is unique to this country + + align:start position:0% +recession that is unique to this country + + + align:start position:0% +recession that is unique to this country +then you're going to do an expansionary + + align:start position:0% +then you're going to do an expansionary + + + align:start position:0% +then you're going to do an expansionary +fiscal policy + + align:start position:0% +fiscal policy + + + align:start position:0% +fiscal policy +what would the Central Bank + + align:start position:0% +what would the Central Bank + + + align:start position:0% +what would the Central Bank +do in close + + align:start position:0% +do in close + + + align:start position:0% +do in close +economy what drop interest rate well in + + align:start position:0% +economy what drop interest rate well in + + + align:start position:0% +economy what drop interest rate well in +open economy does the same you just drop + + align:start position:0% +open economy does the same you just drop + + + align:start position:0% +open economy does the same you just drop +interest rate it turns out that that + + align:start position:0% +interest rate it turns out that that + + + align:start position:0% +interest rate it turns out that that +will depreciate your + + align:start position:0% +will depreciate your + + + align:start position:0% +will depreciate your +currency H which will help you as well + + align:start position:0% +currency H which will help you as well + + + align:start position:0% +currency H which will help you as well +so it's very expansionary because of + + align:start position:0% +so it's very expansionary because of + + + align:start position:0% +so it's very expansionary because of +that no because your currency + + align:start position:0% +that no because your currency + + + align:start position:0% +that no because your currency +depreciates so net export goes up as a + + align:start position:0% +depreciates so net export goes up as a + + + align:start position:0% +depreciates so net export goes up as a +result of that you get the investment + + align:start position:0% +result of that you get the investment + + + align:start position:0% +result of that you get the investment +kick you lose a little bit because part + + align:start position:0% +kick you lose a little bit because part + + + align:start position:0% +kick you lose a little bit because part +goes to import but then you also get the + + align:start position:0% +goes to import but then you also get the + + + align:start position:0% +goes to import but then you also get the +effect of net exports that come from The + + align:start position:0% +effect of net exports that come from The + + + align:start position:0% +effect of net exports that come from The +Exchange okay so monetary policy is a + + align:start position:0% +Exchange okay so monetary policy is a + + + align:start position:0% +Exchange okay so monetary policy is a +great policy in open economy because it + + align:start position:0% +great policy in open economy because it + + + align:start position:0% +great policy in open economy because it +gets reinforced by the exchange rate + + align:start position:0% +gets reinforced by the exchange rate + + + align:start position:0% +gets reinforced by the exchange rate +it's even better than fiscal other + + align:start position:0% +it's even better than fiscal other + + + align:start position:0% +it's even better than fiscal other +things equal when you compare the two + + align:start position:0% +things equal when you compare the two + + + align:start position:0% +things equal when you compare the two +the two policies lost power relative to + + align:start position:0% +the two policies lost power relative to + + + align:start position:0% +the two policies lost power relative to +the close economy because the multipli + + align:start position:0% +the close economy because the multipli + + + align:start position:0% +the close economy because the multipli +is smaller but the difference is that + + align:start position:0% +is smaller but the difference is that + + + align:start position:0% +is smaller but the difference is that +the interest rate policy gets the extra + + align:start position:0% +the interest rate policy gets the extra + + + align:start position:0% +the interest rate policy gets the extra +kick that comes from the depreciation of + + align:start position:0% +kick that comes from the depreciation of + + + align:start position:0% +kick that comes from the depreciation of +the currency okay so it's a very + + align:start position:0% +the currency okay so it's a very + + + align:start position:0% +the currency okay so it's a very +powerful tool + + align:start position:0% + + + + align:start position:0% + +okay so that's what you do if you have a + + align:start position:0% +okay so that's what you do if you have a + + + align:start position:0% +okay so that's what you do if you have a +a flexible exchange rate and that's what + + align:start position:0% +a flexible exchange rate and that's what + + + align:start position:0% +a flexible exchange rate and that's what +countries do in practice when they are F + + align:start position:0% +countries do in practice when they are F + + + align:start position:0% +countries do in practice when they are F +floting suppose you have a fixed + + align:start position:0% +floting suppose you have a fixed + + + align:start position:0% +floting suppose you have a fixed +exchange rate + + align:start position:0% +exchange rate + + + align:start position:0% +exchange rate +regime okay so and it's a credible fixed + + align:start position:0% +regime okay so and it's a credible fixed + + + align:start position:0% +regime okay so and it's a credible fixed +exchange regime then I ask you again the + + align:start position:0% +exchange regime then I ask you again the + + + align:start position:0% +exchange regime then I ask you again the +question + + align:start position:0% +question + + + align:start position:0% +question +what what kind of fiscal policy would + + align:start position:0% +what what kind of fiscal policy would + + + align:start position:0% +what what kind of fiscal policy would +you run in that country + + align:start position:0% + + + + align:start position:0% + +the same expansionary that's what you + + align:start position:0% +the same expansionary that's what you + + + align:start position:0% +the same expansionary that's what you +would do and is effective as it was in + + align:start position:0% +would do and is effective as it was in + + + align:start position:0% +would do and is effective as it was in +close economy a little less because the + + align:start position:0% +close economy a little less because the + + + align:start position:0% +close economy a little less because the +multiply is a little less that's it but + + align:start position:0% +multiply is a little less that's it but + + + align:start position:0% +multiply is a little less that's it but +no difference in the + + align:start position:0% +no difference in the + + + align:start position:0% +no difference in the +analysis in fact fiscal policy has + + align:start position:0% +analysis in fact fiscal policy has + + + align:start position:0% +analysis in fact fiscal policy has +exactly the same effect as as a fiscal + + align:start position:0% +exactly the same effect as as a fiscal + + + align:start position:0% +exactly the same effect as as a fiscal +policy in the flexible exchange rate in + + align:start position:0% +policy in the flexible exchange rate in + + + align:start position:0% +policy in the flexible exchange rate in +this case because I haven't moved + + align:start position:0% +this case because I haven't moved + + + align:start position:0% +this case because I haven't moved +exchange rate in any event in either of + + align:start position:0% +exchange rate in any event in either of + + + align:start position:0% +exchange rate in any event in either of +the two cases okay what should the + + align:start position:0% +the two cases okay what should the + + + align:start position:0% +the two cases okay what should the +Central Bank do + + align:start position:0% + + + + align:start position:0% + +that's a tricky + + align:start position:0% + + + + align:start position:0% + +question yes Central Bank knows so it + + align:start position:0% +question yes Central Bank knows so it + + + align:start position:0% +question yes Central Bank knows so it +will have to match yeah exactly so the + + align:start position:0% +will have to match yeah exactly so the + + + align:start position:0% +will have to match yeah exactly so the +Central Bank cannot do anything I'm + + align:start position:0% +Central Bank cannot do anything I'm + + + align:start position:0% +Central Bank cannot do anything I'm +saying suppose this is an EOS sycratic + + align:start position:0% +saying suppose this is an EOS sycratic + + + align:start position:0% +saying suppose this is an EOS sycratic +recession this countri is in + + align:start position:0% +recession this countri is in + + + align:start position:0% +recession this countri is in +recession now now it wants to use its + + align:start position:0% +recession now now it wants to use its + + + align:start position:0% +recession now now it wants to use its +policy tools to deal with that it has + + align:start position:0% +policy tools to deal with that it has + + + align:start position:0% +policy tools to deal with that it has +fiscal but it doesn't have monetary + + align:start position:0% +fiscal but it doesn't have monetary + + + align:start position:0% +fiscal but it doesn't have monetary +policy unless the cycle of the other + + align:start position:0% +policy unless the cycle of the other + + + align:start position:0% +policy unless the cycle of the other +country coincides with your cycle so + + align:start position:0% +country coincides with your cycle so + + + align:start position:0% +country coincides with your cycle so +it's a global recession or something + + align:start position:0% +it's a global recession or something + + + align:start position:0% +it's a global recession or something +like that then then you're doomed + + align:start position:0% +like that then then you're doomed + + + align:start position:0% +like that then then you're doomed +because other countries doing the + + align:start position:0% +because other countries doing the + + + align:start position:0% +because other countries doing the +monetary policy for what they're doing + + align:start position:0% +monetary policy for what they're doing + + + align:start position:0% +monetary policy for what they're doing +they need not for what you need and + + align:start position:0% +they need not for what you need and + + + align:start position:0% +they need not for what you need and +therefore you don't have monetary policy + + align:start position:0% +therefore you don't have monetary policy + + + align:start position:0% +therefore you don't have monetary policy +so that's a costly thing of a fixed + + align:start position:0% +so that's a costly thing of a fixed + + + align:start position:0% +so that's a costly thing of a fixed +exchange rate we already said it but you + + align:start position:0% +exchange rate we already said it but you + + + align:start position:0% +exchange rate we already said it but you +now we're making it very concrete + + align:start position:0% +now we're making it very concrete + + + align:start position:0% +now we're making it very concrete +because we are in a recession and you + + align:start position:0% +because we are in a recession and you + + + align:start position:0% +because we are in a recession and you +realize now that you don't have a tool + + align:start position:0% +realize now that you don't have a tool + + + align:start position:0% +realize now that you don't have a tool +that you had before okay so that's a + + align:start position:0% +that you had before okay so that's a + + + align:start position:0% +that you had before okay so that's a +cost of a physic + + align:start position:0% +cost of a physic + + + align:start position:0% +cost of a physic +sry here is an example here when I'm + + align:start position:0% +sry here is an example here when I'm + + + align:start position:0% +sry here is an example here when I'm +plotting is the the policy rate in the + + align:start position:0% +plotting is the the policy rate in the + + + align:start position:0% +plotting is the the policy rate in the +US that's the blue one and that's the + + align:start position:0% +US that's the blue one and that's the + + + align:start position:0% +US that's the blue one and that's the +policy rate in Hong Kong there are small + + align:start position:0% +policy rate in Hong Kong there are small + + + align:start position:0% +policy rate in Hong Kong there are small +difference but you can see that the + + align:start position:0% +difference but you can see that the + + + align:start position:0% +difference but you can see that the +these are technical things but you can + + align:start position:0% +these are technical things but you can + + + align:start position:0% +these are technical things but you can +see that that Hong Kong has to follow + + align:start position:0% +see that that Hong Kong has to follow + + + align:start position:0% +see that that Hong Kong has to follow +the US essentially it's exactly the same + + align:start position:0% +the US essentially it's exactly the same + + + align:start position:0% +the US essentially it's exactly the same +shape so Hong Kong doesn't have + + align:start position:0% +shape so Hong Kong doesn't have + + + align:start position:0% +shape so Hong Kong doesn't have +independent monetary policy okay again + + align:start position:0% +independent monetary policy okay again + + + align:start position:0% +independent monetary policy okay again +those are technical gaps are not really + + align:start position:0% +those are technical gaps are not really + + + align:start position:0% +those are technical gaps are not really +but just look at the shape it's exactly + + align:start position:0% +but just look at the shape it's exactly + + + align:start position:0% +but just look at the shape it's exactly +the same mov around so Hong Kong doesn't + + align:start position:0% +the same mov around so Hong Kong doesn't + + + align:start position:0% +the same mov around so Hong Kong doesn't +have monetary policy + + align:start position:0% +have monetary policy + + + align:start position:0% +have monetary policy +period not something they Happ they get + + align:start position:0% +period not something they Happ they get + + + align:start position:0% +period not something they Happ they get +a recession that has to do with their + + align:start position:0% +a recession that has to do with their + + + align:start position:0% +a recession that has to do with their +own cycle and that is not a result of + + align:start position:0% +own cycle and that is not a result of + + + align:start position:0% +own cycle and that is not a result of +something that is happening in the US + + align:start position:0% +something that is happening in the US + + + align:start position:0% +something that is happening in the US +they don't have the tool to deal with + + align:start position:0% +they don't have the tool to deal with + + + align:start position:0% +they don't have the tool to deal with +that of course during Co and and during + + align:start position:0% +that of course during Co and and during + + + align:start position:0% +that of course during Co and and during +the global financial crisis they were + + align:start position:0% +the global financial crisis they were + + + align:start position:0% +the global financial crisis they were +align so they you know they would have + + align:start position:0% +align so they you know they would have + + + align:start position:0% +align so they you know they would have +moved it in the same direction that + + align:start position:0% +moved it in the same direction that + + + align:start position:0% +moved it in the same direction that +worked but if there is a shock that is a + + align:start position:0% +worked but if there is a shock that is a + + + align:start position:0% +worked but if there is a shock that is a +Chinese Centric that is affecting Hong + + align:start position:0% +Chinese Centric that is affecting Hong + + + align:start position:0% +Chinese Centric that is affecting Hong +Kong the US monetary policy is not going + + align:start position:0% +Kong the US monetary policy is not going + + + align:start position:0% +Kong the US monetary policy is not going +to react to that + + align:start position:0% +to react to that + + + align:start position:0% +to react to that +and that that that's a problem for Hong + + align:start position:0% +and that that that's a problem for Hong + + + align:start position:0% +and that that that's a problem for Hong +Hong Kong still they choose to do it the + + align:start position:0% +Hong Kong still they choose to do it the + + + align:start position:0% +Hong Kong still they choose to do it the +good question is + + align:start position:0% +good question is + + + align:start position:0% +good question is +why Always There is politics there is + + align:start position:0% +why Always There is politics there is + + + align:start position:0% +why Always There is politics there is +more than than the kind of thing but + + align:start position:0% +more than than the kind of thing but + + + align:start position:0% +more than than the kind of thing but +there are also economic Arguments for + + align:start position:0% +there are also economic Arguments for + + + align:start position:0% +there are also economic Arguments for +why you may want to do this + + align:start position:0% +why you may want to do this + + + align:start position:0% +why you may want to do this +things another situation that I mention + + align:start position:0% +things another situation that I mention + + + align:start position:0% +things another situation that I mention +happens all the time every other day in + + align:start position:0% +happens all the time every other day in + + + align:start position:0% +happens all the time every other day in +Argentina for example is speculative + + align:start position:0% +Argentina for example is speculative + + + align:start position:0% +Argentina for example is speculative +attacks on the currency so you want to + + align:start position:0% +attacks on the currency so you want to + + + align:start position:0% +attacks on the currency so you want to +have a fixed exchange rate but the + + align:start position:0% +have a fixed exchange rate but the + + + align:start position:0% +have a fixed exchange rate but the +markets don't believe you that you're + + align:start position:0% +markets don't believe you that you're + + + align:start position:0% +markets don't believe you that you're +going to be able to keep in there and uh + + align:start position:0% +going to be able to keep in there and uh + + + align:start position:0% +going to be able to keep in there and uh +and so what happens so look at this + + align:start position:0% +and so what happens so look at this + + + align:start position:0% +and so what happens so look at this +equation here suppose that that that you + + align:start position:0% +equation here suppose that that that you + + + align:start position:0% +equation here suppose that that that you +have a fixed exchange rate but now the + + align:start position:0% +have a fixed exchange rate but now the + + + align:start position:0% +have a fixed exchange rate but now the +market think you're not going to be able + + align:start position:0% +market think you're not going to be able + + + align:start position:0% +market think you're not going to be able +to sustain it okay so that means suppose + + align:start position:0% +to sustain it okay so that means suppose + + + align:start position:0% +to sustain it okay so that means suppose +that this guy starts going down that + + align:start position:0% +that this guy starts going down that + + + align:start position:0% +that this guy starts going down that +happens again in Argentina every other + + align:start position:0% +happens again in Argentina every other + + + align:start position:0% +happens again in Argentina every other +day probably today every single day no + + align:start position:0% +day probably today every single day no + + + align:start position:0% +day probably today every single day no +you want to say that they went to saiz + + align:start position:0% +you want to say that they went to saiz + + + align:start position:0% +you want to say that they went to saiz +exchange rate but the markets don't + + align:start position:0% +exchange rate but the markets don't + + + align:start position:0% +exchange rate but the markets don't +believe you and they expect your + + align:start position:0% +believe you and they expect your + + + align:start position:0% +believe you and they expect your +currency to lose value in the next few + + align:start position:0% +currency to lose value in the next few + + + align:start position:0% +currency to lose value in the next few +hours in the case of Argentina + + align:start position:0% +hours in the case of Argentina + + + align:start position:0% +hours in the case of Argentina +so this guy is going + + align:start position:0% + + + + align:start position:0% + +down what happens to the current to the + + align:start position:0% +down what happens to the current to the + + + align:start position:0% +down what happens to the current to the +to the current exchang so expector + + align:start position:0% +to the current exchang so expector + + + align:start position:0% +to the current exchang so expector +exchange goes + + align:start position:0% +exchange goes + + + align:start position:0% +exchange goes +down everyone expects your currency to + + align:start position:0% + + + + align:start position:0% + +drop what what will tend to happen to + + align:start position:0% +drop what what will tend to happen to + + + align:start position:0% +drop what what will tend to happen to +the currency today to the P + + align:start position:0% + + + + align:start position:0% + +today it drops but you have a fixed + + align:start position:0% +today it drops but you have a fixed + + + align:start position:0% +today it drops but you have a fixed +exchange rate you can't let it drop + + align:start position:0% +exchange rate you can't let it drop + + + align:start position:0% +exchange rate you can't let it drop +so if you're going to maintain an + + align:start position:0% +so if you're going to maintain an + + + align:start position:0% +so if you're going to maintain an +exchange a fixed exchange rate and now + + align:start position:0% +exchange a fixed exchange rate and now + + + align:start position:0% +exchange a fixed exchange rate and now +you have a speculative attack people + + align:start position:0% +you have a speculative attack people + + + align:start position:0% +you have a speculative attack people +think your currency is going to drop and + + align:start position:0% +think your currency is going to drop and + + + align:start position:0% +think your currency is going to drop and +you want to maintain your peeg that's + + align:start position:0% +you want to maintain your peeg that's + + + align:start position:0% +you want to maintain your peeg that's +called defending the peeg if you want to + + align:start position:0% +called defending the peeg if you want to + + + align:start position:0% +called defending the peeg if you want to +defend the peeg then the only option you + + align:start position:0% +defend the peeg then the only option you + + + align:start position:0% +defend the peeg then the only option you +have if this guy is dropping to keep the + + align:start position:0% +have if this guy is dropping to keep the + + + align:start position:0% +have if this guy is dropping to keep the +exchange it is to raise interest rates a + + align:start position:0% +exchange it is to raise interest rates a + + + align:start position:0% +exchange it is to raise interest rates a +lot that's the way you fight the main + + align:start position:0% +lot that's the way you fight the main + + + align:start position:0% +lot that's the way you fight the main +way you fight it I mean you fight it by + + align:start position:0% +way you fight it I mean you fight it by + + + align:start position:0% +way you fight it I mean you fight it by +closing capital accounts and so but + + align:start position:0% +closing capital accounts and so but + + + align:start position:0% +closing capital accounts and so but +that's the last result you first try to + + align:start position:0% +that's the last result you first try to + + + align:start position:0% +that's the last result you first try to +fight it with monetary policy so if this + + align:start position:0% +fight it with monetary policy so if this + + + align:start position:0% +fight it with monetary policy so if this +thing is dropping you fight it by + + align:start position:0% +thing is dropping you fight it by + + + align:start position:0% +thing is dropping you fight it by +increasing interest rate a lot and + + align:start position:0% +increasing interest rate a lot and + + + align:start position:0% +increasing interest rate a lot and +that's the way you stabilize the + + align:start position:0% +that's the way you stabilize the + + + align:start position:0% +that's the way you stabilize the +currency but what happens when you raise + + align:start position:0% +currency but what happens when you raise + + + align:start position:0% +currency but what happens when you raise +interest rate a lot to defend the parity + + align:start position:0% +interest rate a lot to defend the parity + + + align:start position:0% +interest rate a lot to defend the parity +the + + align:start position:0% +the + + + align:start position:0% +the +peg what's the problem of + + align:start position:0% + + + + align:start position:0% + +that yeah you generate a domestic + + align:start position:0% +that yeah you generate a domestic + + + align:start position:0% +that yeah you generate a domestic +recession okay because just to defend + + align:start position:0% +recession okay because just to defend + + + align:start position:0% +recession okay because just to defend +your currency your peg you have to raise + + align:start position:0% +your currency your peg you have to raise + + + align:start position:0% +your currency your peg you have to raise +interest rate a lot no so it means + + align:start position:0% +interest rate a lot no so it means + + + align:start position:0% +interest rate a lot no so it means +you're going to have a recession at + + align:start position:0% + + + + align:start position:0% + +home so that's another problem of fix + + align:start position:0% +home so that's another problem of fix + + + align:start position:0% +home so that's another problem of fix +exchange it's a problem that's not a + + align:start position:0% +exchange it's a problem that's not a + + + align:start position:0% +exchange it's a problem that's not a +problem for Hong Kong it was in 1997 + + align:start position:0% +problem for Hong Kong it was in 1997 + + + align:start position:0% +problem for Hong Kong it was in 1997 +they did have a speculated attack + + align:start position:0% +they did have a speculated attack + + + align:start position:0% +they did have a speculated attack +despite the fact that they had twice the + + align:start position:0% +despite the fact that they had twice the + + + align:start position:0% +despite the fact that they had twice the +number of reserves relative to their + + align:start position:0% +number of reserves relative to their + + + align:start position:0% +number of reserves relative to their +money base but still they have specul + + align:start position:0% +money base but still they have specul + + + align:start position:0% +money base but still they have specul +that but it rarely happens in Hong Kong + + align:start position:0% +that but it rarely happens in Hong Kong + + + align:start position:0% +that but it rarely happens in Hong Kong +in Argentina again every other day but + + align:start position:0% +in Argentina again every other day but + + + align:start position:0% +in Argentina again every other day but +but in same in Turkey in Turkey is every + + align:start position:0% +but in same in Turkey in Turkey is every + + + align:start position:0% +but in same in Turkey in Turkey is every +15 days but but but uh but it's + + align:start position:0% +15 days but but but uh but it's + + + align:start position:0% +15 days but but but uh but it's +happening all the + + align:start position:0% +happening all the + + + align:start position:0% +happening all the +time so that's a problem as well because + + align:start position:0% +time so that's a problem as well because + + + align:start position:0% +time so that's a problem as well because +if you have to spend a lot of energy + + align:start position:0% +if you have to spend a lot of energy + + + align:start position:0% +if you have to spend a lot of energy +defending your peg then you're going to + + align:start position:0% +defending your peg then you're going to + + + align:start position:0% +defending your peg then you're going to +be causing lots of recessions at home + + align:start position:0% +be causing lots of recessions at home + + + align:start position:0% +be causing lots of recessions at home +just to stabilize the currency + + align:start position:0% +just to stabilize the currency + + + align:start position:0% +just to stabilize the currency +okay that's that's bigger economy say + + align:start position:0% +okay that's that's bigger economy say + + + align:start position:0% +okay that's that's bigger economy say +okay well Argentina turkey and so on + + align:start position:0% +okay well Argentina turkey and so on + + + align:start position:0% +okay well Argentina turkey and so on +know but these are bigger boys no here + + align:start position:0% +know but these are bigger boys no here + + + align:start position:0% +know but these are bigger boys no here +we + + align:start position:0% +we + + + align:start position:0% +we +have this is the ERM crisis so before + + align:start position:0% +have this is the ERM crisis so before + + + align:start position:0% +have this is the ERM crisis so before +the + + align:start position:0% +the + + + align:start position:0% +the +euro uh more or the Euro Zone plus the + + align:start position:0% +euro uh more or the Euro Zone plus the + + + align:start position:0% +euro uh more or the Euro Zone plus the +UK H had a system called the + + align:start position:0% +UK H had a system called the + + + align:start position:0% +UK H had a system called the +ERM em emsm ERM is the well anyway EMS + + align:start position:0% +ERM em emsm ERM is the well anyway EMS + + + align:start position:0% +ERM em emsm ERM is the well anyway EMS +is European monetary system ERM is + + align:start position:0% +is European monetary system ERM is + + + align:start position:0% +is European monetary system ERM is +exchang rates mechanism or something + + align:start position:0% +exchang rates mechanism or something + + + align:start position:0% +exchang rates mechanism or something +like that and they're both link but + + align:start position:0% +like that and they're both link but + + + align:start position:0% +like that and they're both link but +let's call it the the the European + + align:start position:0% +let's call it the the the European + + + align:start position:0% +let's call it the the the European +monetary system and the basic idea of + + align:start position:0% +monetary system and the basic idea of + + + align:start position:0% +monetary system and the basic idea of +the European monetary + + align:start position:0% +the European monetary + + + align:start position:0% +the European monetary +system was that + + align:start position:0% +system was that + + + align:start position:0% +system was that +that they behave very much like + + align:start position:0% +that they behave very much like + + + align:start position:0% +that they behave very much like +Singapore with respect to each other + + align:start position:0% +Singapore with respect to each other + + + align:start position:0% +Singapore with respect to each other +meaning they allow themselves to H move + + align:start position:0% +meaning they allow themselves to H move + + + align:start position:0% +meaning they allow themselves to H move +around but only in narrow bands the the + + align:start position:0% +around but only in narrow bands the the + + + align:start position:0% +around but only in narrow bands the the +countries that have the more + + align:start position:0% +countries that have the more + + + align:start position:0% +countries that have the more +stable um domestic monetary position + + align:start position:0% +stable um domestic monetary position + + + align:start position:0% +stable um domestic monetary position +like France Vis the Germany the Dutch + + align:start position:0% +like France Vis the Germany the Dutch + + + align:start position:0% +like France Vis the Germany the Dutch +Mark and the French Frank what they had + + align:start position:0% +Mark and the French Frank what they had + + + align:start position:0% +Mark and the French Frank what they had +is bands of Two and a half% up and down + + align:start position:0% +is bands of Two and a half% up and down + + + align:start position:0% +is bands of Two and a half% up and down +and they move within those those ranges + + align:start position:0% +and they move within those those ranges + + + align:start position:0% +and they move within those those ranges +they didn't have a full Peg but they + + align:start position:0% +they didn't have a full Peg but they + + + align:start position:0% +they didn't have a full Peg but they +allow themselves to move a little bit + + align:start position:0% +allow themselves to move a little bit + + + align:start position:0% +allow themselves to move a little bit +Portugal which was a little had little + + align:start position:0% +Portugal which was a little had little + + + align:start position:0% +Portugal which was a little had little +less discipline they had 5% for each + + align:start position:0% +less discipline they had 5% for each + + + align:start position:0% +less discipline they had 5% for each +side and stuff like that but the point + + align:start position:0% +side and stuff like that but the point + + + align:start position:0% +side and stuff like that but the point +is they would have narrow bands okay and + + align:start position:0% +is they would have narrow bands okay and + + + align:start position:0% +is they would have narrow bands okay and +they move around in those narrow bands + + align:start position:0% +they move around in those narrow bands + + + align:start position:0% +they move around in those narrow bands +and they kept there ER kept it for quite + + align:start position:0% +and they kept there ER kept it for quite + + + align:start position:0% +and they kept there ER kept it for quite +a while before the + + align:start position:0% +a while before the + + + align:start position:0% +a while before the +euro now here the whole system came + + align:start position:0% +euro now here the whole system came + + + align:start position:0% +euro now here the whole system came +under a speculative + + align:start position:0% + + + + align:start position:0% + +attack what happened around + + align:start position:0% +attack what happened around + + + align:start position:0% +attack what happened around +there you probably have no + + align:start position:0% +there you probably have no + + + align:start position:0% +there you probably have no +idea maybe like the end of the + + align:start position:0% +idea maybe like the end of the + + + align:start position:0% +idea maybe like the end of the +well it's really linked to that + + align:start position:0% +well it's really linked to that + + + align:start position:0% +well it's really linked to that +yes yeah it's the German re + + align:start position:0% +yes yeah it's the German re + + + align:start position:0% +yes yeah it's the German re +reunification so what happened is when + + align:start position:0% +reunification so what happened is when + + + align:start position:0% +reunification so what happened is when +East Germany and West Germany unify they + + align:start position:0% +East Germany and West Germany unify they + + + align:start position:0% +East Germany and West Germany unify they +had to have a massive fiscal policy Mass + + align:start position:0% +had to have a massive fiscal policy Mass + + + align:start position:0% +had to have a massive fiscal policy Mass +expansionary fiscal policy and that big + + align:start position:0% +expansionary fiscal policy and that big + + + align:start position:0% +expansionary fiscal policy and that big +expansion put lots of upward pressure on + + align:start position:0% +expansion put lots of upward pressure on + + + align:start position:0% +expansion put lots of upward pressure on +Dom on on on on German interest rates + + align:start position:0% +Dom on on on on German interest rates + + + align:start position:0% +Dom on on on on German interest rates +and and that led to Big + + align:start position:0% +and and that led to Big + + + align:start position:0% +and and that led to Big +appreciations of the Dutch Market and + + align:start position:0% +appreciations of the Dutch Market and + + + align:start position:0% +appreciations of the Dutch Market and +and the other countries tried to fight + + align:start position:0% +and the other countries tried to fight + + + align:start position:0% +and the other countries tried to fight +it because they had to be in this very + + align:start position:0% +it because they had to be in this very + + + align:start position:0% +it because they had to be in this very +narrow band but they were experiencing + + align:start position:0% +narrow band but they were experiencing + + + align:start position:0% +narrow band but they were experiencing +this big speculative attacks and so they + + align:start position:0% +this big speculative attacks and so they + + + align:start position:0% +this big speculative attacks and so they +had to raise their interest rate + + align:start position:0% +had to raise their interest rate + + + align:start position:0% +had to raise their interest rate +enormously H the UK tried to do it for a + + align:start position:0% +enormously H the UK tried to do it for a + + + align:start position:0% +enormously H the UK tried to do it for a +while and I we give up and then they + + align:start position:0% +while and I we give up and then they + + + align:start position:0% +while and I we give up and then they +they they they abandoned the system the + + align:start position:0% +they they they abandoned the system the + + + align:start position:0% +they they they abandoned the system the +French tried to stay in there for quite + + align:start position:0% +French tried to stay in there for quite + + + align:start position:0% +French tried to stay in there for quite +a bit okay you can see the French Frank + + align:start position:0% +a bit okay you can see the French Frank + + + align:start position:0% +a bit okay you can see the French Frank +they didn't move they didn't move but it + + align:start position:0% +they didn't move they didn't move but it + + + align:start position:0% +they didn't move they didn't move but it +was extremely costly for them because + + align:start position:0% +was extremely costly for them because + + + align:start position:0% +was extremely costly for them because +the interest rate has to go up a lot and + + align:start position:0% +the interest rate has to go up a lot and + + + align:start position:0% +the interest rate has to go up a lot and +sort of they got into big recession and + + align:start position:0% +sort of they got into big recession and + + + align:start position:0% +sort of they got into big recession and +eventually the whole system broke up + + align:start position:0% +eventually the whole system broke up + + + align:start position:0% +eventually the whole system broke up +broke down I mean everyone left and + + align:start position:0% +broke down I mean everyone left and + + + align:start position:0% +broke down I mean everyone left and +eventually they rejoined but now in the + + align:start position:0% +eventually they rejoined but now in the + + + align:start position:0% +eventually they rejoined but now in the +Euro and the euro is a little different + + align:start position:0% +Euro and the euro is a little different + + + align:start position:0% +Euro and the euro is a little different +because in the Euro you gave up there's + + align:start position:0% +because in the Euro you gave up there's + + + align:start position:0% +because in the Euro you gave up there's +no space for speculative attacks because + + align:start position:0% +no space for speculative attacks because + + + align:start position:0% +no space for speculative attacks because +there's a single currency okay so that's + + align:start position:0% +there's a single currency okay so that's + + + align:start position:0% +there's a single currency okay so that's +that's the most extreme form speculative + + align:start position:0% +that's the most extreme form speculative + + + align:start position:0% +that's the most extreme form speculative +attacks nowadays in Europe happen + + align:start position:0% +attacks nowadays in Europe happen + + + align:start position:0% +attacks nowadays in Europe happen +through different + + align:start position:0% +through different + + + align:start position:0% +through different +means it's the well anyways let me not + + align:start position:0% +means it's the well anyways let me not + + + align:start position:0% +means it's the well anyways let me not +get into that but but but here you have + + align:start position:0% +get into that but but but here you have + + + align:start position:0% +get into that but but but here you have +so I'm saying having a fixed exchange is + + align:start position:0% +so I'm saying having a fixed exchange is + + + align:start position:0% +so I'm saying having a fixed exchange is +not easy even for countries that have + + align:start position:0% +not easy even for countries that have + + + align:start position:0% +not easy even for countries that have +sort of very welldeveloped financial + + align:start position:0% +sort of very welldeveloped financial + + + align:start position:0% +sort of very welldeveloped financial +markets and so on so + + align:start position:0% +markets and so on so + + + align:start position:0% +markets and so on so +forth now it would seem given all that I + + align:start position:0% +forth now it would seem given all that I + + + align:start position:0% +forth now it would seem given all that I +said that I mean there's no reason to + + align:start position:0% +said that I mean there's no reason to + + + align:start position:0% +said that I mean there's no reason to +have a fixed exchange is something you + + align:start position:0% +have a fixed exchange is something you + + + align:start position:0% +have a fixed exchange is something you +look give up an instrument and on top of + + align:start position:0% +look give up an instrument and on top of + + + align:start position:0% +look give up an instrument and on top of +that you are subject to speculative + + align:start position:0% +that you are subject to speculative + + + align:start position:0% +that you are subject to speculative +attacks all the time okay not all the + + align:start position:0% +attacks all the time okay not all the + + + align:start position:0% +attacks all the time okay not all the +time well it depends on how bad you are + + align:start position:0% +time well it depends on how bad you are + + + align:start position:0% +time well it depends on how bad you are +but but you know you have to be very + + align:start position:0% +but but you know you have to be very + + + align:start position:0% +but but you know you have to be very +well behave because otherwise you're + + align:start position:0% +well behave because otherwise you're + + + align:start position:0% +well behave because otherwise you're +subject to speculative attacks all the + + align:start position:0% +subject to speculative attacks all the + + + align:start position:0% +subject to speculative attacks all the +time so so why not do flexible exchange + + align:start position:0% +time so so why not do flexible exchange + + + align:start position:0% +time so so why not do flexible exchange +why why what is wrong with flexible + + align:start position:0% +why why what is wrong with flexible + + + align:start position:0% +why why what is wrong with flexible +exchange rate well I think the main + + align:start position:0% +exchange rate well I think the main + + + align:start position:0% +exchange rate well I think the main +problem of flexible exchange rate is + + align:start position:0% +problem of flexible exchange rate is + + + align:start position:0% +problem of flexible exchange rate is +that it tends to move a lot I mean we + + align:start position:0% +that it tends to move a lot I mean we + + + align:start position:0% +that it tends to move a lot I mean we +know that it moves a lot more than + + align:start position:0% +know that it moves a lot more than + + + align:start position:0% +know that it moves a lot more than +fundamental meaning you know + + align:start position:0% +fundamental meaning you know + + + align:start position:0% +fundamental meaning you know +productivity is a little higher in one + + align:start position:0% +productivity is a little higher in one + + + align:start position:0% +productivity is a little higher in one +country than the other demand is a + + align:start position:0% +country than the other demand is a + + + align:start position:0% +country than the other demand is a +little high in the the country but CH + + align:start position:0% +little high in the the country but CH + + + align:start position:0% +little high in the the country but CH +moves a lot more than those little + + align:start position:0% +moves a lot more than those little + + + align:start position:0% +moves a lot more than those little +differences justify + + align:start position:0% +differences justify + + + align:start position:0% +differences justify +and the reason one way of understanding + + align:start position:0% +and the reason one way of understanding + + + align:start position:0% +and the reason one way of understanding +this is the following and this will see + + align:start position:0% +this is the following and this will see + + + align:start position:0% +this is the following and this will see +serve as an introduction to the next + + align:start position:0% +serve as an introduction to the next + + + align:start position:0% +serve as an introduction to the next +topic of the course which will be asset + + align:start position:0% +topic of the course which will be asset + + + align:start position:0% +topic of the course which will be asset +pricing and things like that so let's + + align:start position:0% +pricing and things like that so let's + + + align:start position:0% +pricing and things like that so let's +look at revisit our interest parity + + align:start position:0% +look at revisit our interest parity + + + align:start position:0% +look at revisit our interest parity +condition but now let's not assume that + + align:start position:0% +condition but now let's not assume that + + + align:start position:0% +condition but now let's not assume that +that that the next the the the expected + + align:start position:0% +that that the next the the the expected + + + align:start position:0% +that that the next the the the expected +exchang is fixed I mean that was an + + align:start position:0% +exchang is fixed I mean that was an + + + align:start position:0% +exchang is fixed I mean that was an +assumption just to make our life simple + + align:start position:0% +assumption just to make our life simple + + + align:start position:0% +assumption just to make our life simple +but but needs not be so that's a that's + + align:start position:0% +but but needs not be so that's a that's + + + align:start position:0% +but but needs not be so that's a that's +the uncovering transparity condition is + + align:start position:0% +the uncovering transparity condition is + + + align:start position:0% +the uncovering transparity condition is +this well you see I can replace this guy + + align:start position:0% +this well you see I can replace this guy + + + align:start position:0% +this well you see I can replace this guy +here for what will happen next period + + align:start position:0% +here for what will happen next period + + + align:start position:0% +here for what will happen next period +it's the same thing shifted by a period + + align:start position:0% +it's the same thing shifted by a period + + + align:start position:0% +it's the same thing shifted by a period +with an expectation there so e+ one + + align:start position:0% +with an expectation there so e+ one + + + align:start position:0% +with an expectation there so e+ one +expected this guy here is equal to 1 + + align:start position:0% +expected this guy here is equal to 1 + + + align:start position:0% +expected this guy here is equal to 1 +plus expected domestic interest rate one + + align:start position:0% +plus expected domestic interest rate one + + + align:start position:0% +plus expected domestic interest rate one +period from now divided by 1 plus + + align:start position:0% +period from now divided by 1 plus + + + align:start position:0% +period from now divided by 1 plus +International interest expected one + + align:start position:0% +International interest expected one + + + align:start position:0% +International interest expected one +period from now times the expector + + align:start position:0% +period from now times the expector + + + align:start position:0% +period from now times the expector +exchange it for t plus two two years + + align:start position:0% +exchange it for t plus two two years + + + align:start position:0% +exchange it for t plus two two years +from now and I can keep doing this I can + + align:start position:0% +from now and I can keep doing this I can + + + align:start position:0% +from now and I can keep doing this I can +replace this by something equivalent to + + align:start position:0% +replace this by something equivalent to + + + align:start position:0% +replace this by something equivalent to +that with all the sub index shift by one + + align:start position:0% +that with all the sub index shift by one + + + align:start position:0% +that with all the sub index shift by one +year blah blah blah blah blah and so I + + align:start position:0% +year blah blah blah blah blah and so I + + + align:start position:0% +year blah blah blah blah blah and so I +can end up writing this exchange rate as + + align:start position:0% +can end up writing this exchange rate as + + + align:start position:0% +can end up writing this exchange rate as +this product of lots of things that can + + align:start position:0% +this product of lots of things that can + + + align:start position:0% +this product of lots of things that can +happen in the future the the monetary + + align:start position:0% +happen in the future the the monetary + + + align:start position:0% +happen in the future the the monetary +policy path at home the monetary policy + + align:start position:0% +policy path at home the monetary policy + + + align:start position:0% +policy path at home the monetary policy +path not the next period the path for + + align:start position:0% +path not the next period the path for + + + align:start position:0% +path not the next period the path for +years to come of H monetary policy in + + align:start position:0% +years to come of H monetary policy in + + + align:start position:0% +years to come of H monetary policy in +the other country and there's always an + + align:start position:0% +the other country and there's always an + + + align:start position:0% +the other country and there's always an +expected exchange rate at the end there + + align:start position:0% +expected exchange rate at the end there + + + align:start position:0% +expected exchange rate at the end there +that that that is free can move + + align:start position:0% +that that that is free can move + + + align:start position:0% +that that that is free can move +around so the the problem of this + + align:start position:0% +around so the the problem of this + + + align:start position:0% +around so the the problem of this +exchang is that future matters too + + align:start position:0% +exchang is that future matters too + + + align:start position:0% +exchang is that future matters too +much in a sense and you know people have + + align:start position:0% +much in a sense and you know people have + + + align:start position:0% +much in a sense and you know people have +lots of imagination so all sort of weird + + align:start position:0% +lots of imagination so all sort of weird + + + align:start position:0% +lots of imagination so all sort of weird +things they imagine and and when people + + align:start position:0% +things they imagine and and when people + + + align:start position:0% +things they imagine and and when people +have lots of imagination then these + + align:start position:0% +have lots of imagination then these + + + align:start position:0% +have lots of imagination then these +things are moving a lot and that's the + + align:start position:0% +things are moving a lot and that's the + + + align:start position:0% +things are moving a lot and that's the +reason you see enormous fluctuations in + + align:start position:0% +reason you see enormous fluctuations in + + + align:start position:0% +reason you see enormous fluctuations in +nominal exchange rate + + align:start position:0% +nominal exchange rate + + + align:start position:0% +nominal exchange rate +now ER and that's a problem it's a + + align:start position:0% +now ER and that's a problem it's a + + + align:start position:0% +now ER and that's a problem it's a +problem to have a very volatile exchange + + align:start position:0% +problem to have a very volatile exchange + + + align:start position:0% +problem to have a very volatile exchange +rate because it it makes transactions + + align:start position:0% +rate because it it makes transactions + + + align:start position:0% +rate because it it makes transactions +more difficult I mean you know if the + + align:start position:0% +more difficult I mean you know if the + + + align:start position:0% +more difficult I mean you know if the +price of things are relative price of + + align:start position:0% +price of things are relative price of + + + align:start position:0% +price of things are relative price of +things are changing all the time it's a + + align:start position:0% +things are changing all the time it's a + + + align:start position:0% +things are changing all the time it's a +little bit more difficult to plan er + + align:start position:0% +little bit more difficult to plan er + + + align:start position:0% +little bit more difficult to plan er +Financial investment become more comp + + align:start position:0% +Financial investment become more comp + + + align:start position:0% +Financial investment become more comp +because you get all this exchange rate + + align:start position:0% +because you get all this exchange rate + + + align:start position:0% +because you get all this exchange rate +volatility in between so that's one of + + align:start position:0% +volatility in between so that's one of + + + align:start position:0% +volatility in between so that's one of +the main + + align:start position:0% +the main + + + align:start position:0% +the main +reasons you would prefer if you could to + + align:start position:0% +reasons you would prefer if you could to + + + align:start position:0% +reasons you would prefer if you could to +have a more managed exchange rate it's + + align:start position:0% +have a more managed exchange rate it's + + + align:start position:0% +have a more managed exchange rate it's +because you don't want this all this + + align:start position:0% +because you don't want this all this + + + align:start position:0% +because you don't want this all this +artificial volatility that comes from + + align:start position:0% +artificial volatility that comes from + + + align:start position:0% +artificial volatility that comes from +behavioral trades and things of that + + align:start position:0% +behavioral trades and things of that + + + align:start position:0% +behavioral trades and things of that +kind okay that's the main + + align:start position:0% +kind okay that's the main + + + align:start position:0% +kind okay that's the main +reason ER look at this example for + + align:start position:0% +reason ER look at this example for + + + align:start position:0% +reason ER look at this example for +example example for example sorry about + + align:start position:0% +example example for example sorry about + + + align:start position:0% +example example for example sorry about +that but the this is Russia during the + + align:start position:0% +that but the this is Russia during the + + + align:start position:0% +that but the this is Russia during the +the the + + align:start position:0% +the the + + + align:start position:0% +the the +war this was the the the the rubble the + + align:start position:0% +war this was the the the the rubble the + + + align:start position:0% +war this was the the the the rubble the +the the the Russian + + align:start position:0% +the the the Russian + + + align:start position:0% +the the the Russian +currency and when they invaded of course + + align:start position:0% +currency and when they invaded of course + + + align:start position:0% +currency and when they invaded of course +the thing collapsed the currency + + align:start position:0% +the thing collapsed the currency + + + align:start position:0% +the thing collapsed the currency +collapsed + + align:start position:0% +collapsed + + + align:start position:0% +collapsed +okay H this period is a is a little + + align:start position:0% +okay H this period is a is a little + + + align:start position:0% +okay H this period is a is a little +longer than you think but but it + + align:start position:0% +longer than you think but but it + + + align:start position:0% +longer than you think but but it +collapsed for for quite a while and then + + align:start position:0% +collapsed for for quite a while and then + + + align:start position:0% +collapsed for for quite a while and then +you recover a lot actually overshot and + + align:start position:0% +you recover a lot actually overshot and + + + align:start position:0% +you recover a lot actually overshot and +came down so this is not because the + + align:start position:0% +came down so this is not because the + + + align:start position:0% +came down so this is not because the +Central Bank said you know we're going + + align:start position:0% +Central Bank said you know we're going + + + align:start position:0% +Central Bank said you know we're going +to devalue the Curren anything just + + align:start position:0% +to devalue the Curren anything just + + + align:start position:0% +to devalue the Curren anything just +people so wow this a country going into + + align:start position:0% +people so wow this a country going into + + + align:start position:0% +people so wow this a country going into +war it's going to be a mess so all that + + align:start position:0% +war it's going to be a mess so all that + + + align:start position:0% +war it's going to be a mess so all that +future I talk + + align:start position:0% +future I talk + + + align:start position:0% +future I talk +about er er essentially destroy the + + align:start position:0% +about er er essentially destroy the + + + align:start position:0% +about er er essentially destroy the +currency okay now a lot of that recovery + + align:start position:0% +currency okay now a lot of that recovery + + + align:start position:0% +currency okay now a lot of that recovery +happened there not because people now + + align:start position:0% +happened there not because people now + + + align:start position:0% +happened there not because people now +began to see the future as a better + + align:start position:0% +began to see the future as a better + + + align:start position:0% +began to see the future as a better +future or anything like that is because + + align:start position:0% +future or anything like that is because + + + align:start position:0% +future or anything like that is because +they have to hike interest rate + + align:start position:0% +they have to hike interest rate + + + align:start position:0% +they have to hike interest rate +massively they were around four or 5% + + align:start position:0% +massively they were around four or 5% + + + align:start position:0% +massively they were around four or 5% +and they had to go to 20% interest rate + + align:start position:0% +and they had to go to 20% interest rate + + + align:start position:0% +and they had to go to 20% interest rate +to defend exchange rate remember I told + + align:start position:0% +to defend exchange rate remember I told + + + align:start position:0% +to defend exchange rate remember I told +you I speculative attack and you have + + align:start position:0% +you I speculative attack and you have + + + align:start position:0% +you I speculative attack and you have +enormous pressure on your currency well + + align:start position:0% +enormous pressure on your currency well + + + align:start position:0% +enormous pressure on your currency well +the main tool you have toet that is to + + align:start position:0% +the main tool you have toet that is to + + + align:start position:0% +the main tool you have toet that is to +raise interest rate they had they had + + align:start position:0% +raise interest rate they had they had + + + align:start position:0% +raise interest rate they had they had +interest rate massively they do a lot of + + align:start position:0% +interest rate massively they do a lot of + + + align:start position:0% +interest rate massively they do a lot of +other things as well they put Capital + + align:start position:0% +other things as well they put Capital + + + align:start position:0% +other things as well they put Capital +controls and lots of things but but but + + align:start position:0% +controls and lots of things but but but + + + align:start position:0% +controls and lots of things but but but +this was the main thing they did and so + + align:start position:0% +this was the main thing they did and so + + + align:start position:0% +this was the main thing they did and so +they drag the recession the economy into + + align:start position:0% +they drag the recession the economy into + + + align:start position:0% +they drag the recession the economy into +recession for war related reasons and + + align:start position:0% +recession for war related reasons and + + + align:start position:0% +recession for war related reasons and +because of the monetary policy response + + align:start position:0% +because of the monetary policy response + + + align:start position:0% +because of the monetary policy response +they had to do with that okay so that's + + align:start position:0% +they had to do with that okay so that's + + + align:start position:0% +they had to do with that okay so that's +an extreme case of a war but but that's + + align:start position:0% +an extreme case of a war but but that's + + + align:start position:0% +an extreme case of a war but but that's +the kind of things that can + + align:start position:0% +the kind of things that can + + + align:start position:0% +the kind of things that can +happen in in in in in a floating + + align:start position:0% +happen in in in in in a floating + + + align:start position:0% +happen in in in in in a floating +exchange rate even + + align:start position:0% +exchange rate even + + + align:start position:0% +exchange rate even +when + + align:start position:0% +when + + + align:start position:0% +when +um I mean the main constraint in + + align:start position:0% +um I mean the main constraint in + + + align:start position:0% +um I mean the main constraint in +Argentina and turkey and so on is + + align:start position:0% +Argentina and turkey and so on is + + + align:start position:0% +Argentina and turkey and so on is +reserved they don't have enough reserves + + align:start position:0% +reserved they don't have enough reserves + + + align:start position:0% +reserved they don't have enough reserves +so if you have to defend your currency + + align:start position:0% +so if you have to defend your currency + + + align:start position:0% +so if you have to defend your currency +by intervening in the in the in the FX + + align:start position:0% +by intervening in the in the in the FX + + + align:start position:0% +by intervening in the in the in the FX +Market if you don't have enough then + + align:start position:0% +Market if you don't have enough then + + + align:start position:0% +Market if you don't have enough then +you're not credible I mean if you have + + align:start position:0% +you're not credible I mean if you have + + + align:start position:0% +you're not credible I mean if you have +massive capital outflows and you have + + align:start position:0% +massive capital outflows and you have + + + align:start position:0% +massive capital outflows and you have +have a few billion dollars there it's + + align:start position:0% +have a few billion dollars there it's + + + align:start position:0% +have a few billion dollars there it's +not going to work that's not the case of + + align:start position:0% +not going to work that's not the case of + + + align:start position:0% +not going to work that's not the case of +Russia they had massive amount of + + align:start position:0% +Russia they had massive amount of + + + align:start position:0% +Russia they had massive amount of +reserves so that that was not the issue + + align:start position:0% +reserves so that that was not the issue + + + align:start position:0% +reserves so that that was not the issue +it was all about expectations of things + + align:start position:0% +it was all about expectations of things + + + align:start position:0% +it was all about expectations of things +that happen in the future it was all + + align:start position:0% +that happen in the future it was all + + + align:start position:0% +that happen in the future it was all +about these kind of terms + + align:start position:0% +about these kind of terms + + + align:start position:0% +about these kind of terms +okay anyways so so that added to the + + align:start position:0% +okay anyways so so that added to the + + + align:start position:0% +okay anyways so so that added to the +cost they had + + align:start position:0% +cost they had + + + align:start position:0% +cost they had +so so how do we choose these things then + + align:start position:0% +so so how do we choose these things then + + + align:start position:0% +so so how do we choose these things then +in practice H again there are lots of + + align:start position:0% +in practice H again there are lots of + + + align:start position:0% +in practice H again there are lots of +things and politics play play role and + + align:start position:0% +things and politics play play role and + + + align:start position:0% +things and politics play play role and +so on + + align:start position:0% +so on + + + align:start position:0% +so on +ER but there there's a case so so so + + align:start position:0% +ER but there there's a case so so so + + + align:start position:0% +ER but there there's a case so so so +again I would put it even the other way + + align:start position:0% +again I would put it even the other way + + + align:start position:0% +again I would put it even the other way +around I think that if you could you + + align:start position:0% +around I think that if you could you + + + align:start position:0% +around I think that if you could you +would like to have a fixed exchange + + align:start position:0% +would like to have a fixed exchange + + + align:start position:0% +would like to have a fixed exchange +rate if you could you would like to have + + align:start position:0% +rate if you could you would like to have + + + align:start position:0% +rate if you could you would like to have +a fixed exchange rate because then you + + align:start position:0% +a fixed exchange rate because then you + + + align:start position:0% +a fixed exchange rate because then you +remove all this spous noise that happens + + align:start position:0% +remove all this spous noise that happens + + + align:start position:0% +remove all this spous noise that happens +every single day because of exchange + + align:start position:0% +every single day because of exchange + + + align:start position:0% +every single day because of exchange +volatility that complicates your + + align:start position:0% +volatility that complicates your + + + align:start position:0% +volatility that complicates your +life uh but so when can you do that well + + align:start position:0% +life uh but so when can you do that well + + + align:start position:0% +life uh but so when can you do that well +first you can do it with respect to some + + align:start position:0% +first you can do it with respect to some + + + align:start position:0% +first you can do it with respect to some +other country where the shocks are very + + align:start position:0% +other country where the shocks are very + + + align:start position:0% +other country where the shocks are very +similar no because you know if you know + + align:start position:0% +similar no because you know if you know + + + align:start position:0% +similar no because you know if you know +that that that say you're Mexico but or + + align:start position:0% +that that that say you're Mexico but or + + + align:start position:0% +that that that say you're Mexico but or +the north of Mexico something like that + + align:start position:0% +the north of Mexico something like that + + + align:start position:0% +the north of Mexico something like that +and you know that all your shocks are + + align:start position:0% +and you know that all your shocks are + + + align:start position:0% +and you know that all your shocks are +really shocks to the US then the US can + + align:start position:0% +really shocks to the US then the US can + + + align:start position:0% +really shocks to the US then the US can +do the monetary policy for you because + + align:start position:0% +do the monetary policy for you because + + + align:start position:0% +do the monetary policy for you because +you have the same shocks I'm + + align:start position:0% +you have the same shocks I'm + + + align:start position:0% +you have the same shocks I'm +exaggerating so if you're very + + align:start position:0% +exaggerating so if you're very + + + align:start position:0% +exaggerating so if you're very +similar then it makes sense to have a + + align:start position:0% +similar then it makes sense to have a + + + align:start position:0% +similar then it makes sense to have a +fix exchange because why pay for all + + align:start position:0% +fix exchange because why pay for all + + + align:start position:0% +fix exchange because why pay for all +that volatility when you're going to be + + align:start position:0% +that volatility when you're going to be + + + align:start position:0% +that volatility when you're going to be +doing the same policies in both + + align:start position:0% +doing the same policies in both + + + align:start position:0% +doing the same policies in both +countries more or less at the same time + + align:start position:0% +countries more or less at the same time + + + align:start position:0% +countries more or less at the same time +because you're exposed to the same + + align:start position:0% +because you're exposed to the same + + + align:start position:0% +because you're exposed to the same +shocks so that's one thing that's one + + align:start position:0% +shocks so that's one thing that's one + + + align:start position:0% +shocks so that's one thing that's one +reason why the Euro zone is the Euro + + align:start position:0% +reason why the Euro zone is the Euro + + + align:start position:0% +reason why the Euro zone is the Euro +Zone because they European countries + + align:start position:0% +Zone because they European countries + + + align:start position:0% +Zone because they European countries +that have very similar business cycles + + align:start position:0% +that have very similar business cycles + + + align:start position:0% +that have very similar business cycles +and so on Germany is a little different + + align:start position:0% +and so on Germany is a little different + + + align:start position:0% +and so on Germany is a little different +that's the reason they always have some + + align:start position:0% +that's the reason they always have some + + + align:start position:0% +that's the reason they always have some +problem I mean the North and the South + + align:start position:0% +problem I mean the North and the South + + + align:start position:0% +problem I mean the North and the South +they're a little different but but but + + align:start position:0% +they're a little different but but but + + + align:start position:0% +they're a little different but but but +they're much more similar than than + + align:start position:0% +they're much more similar than than + + + align:start position:0% +they're much more similar than than +other countries + + align:start position:0% +other countries + + + align:start position:0% +other countries +um so so that's that's what they have + + align:start position:0% +um so so that's that's what they have + + + align:start position:0% +um so so that's that's what they have +one another option is is is when you + + align:start position:0% +one another option is is is when you + + + align:start position:0% +one another option is is is when you +have lots of fiscal + + align:start position:0% +have lots of fiscal + + + align:start position:0% +have lots of fiscal +capacity because if you have lots of + + align:start position:0% +capacity because if you have lots of + + + align:start position:0% +capacity because if you have lots of +fiscal capacity then the cost of not + + align:start position:0% +fiscal capacity then the cost of not + + + align:start position:0% +fiscal capacity then the cost of not +having monetary polic is not that large + + align:start position:0% +having monetary polic is not that large + + + align:start position:0% +having monetary polic is not that large +because you can fight your business + + align:start position:0% +because you can fight your business + + + align:start position:0% +because you can fight your business +cycle with fiscal policy that's the case + + align:start position:0% +cycle with fiscal policy that's the case + + + align:start position:0% +cycle with fiscal policy that's the case +of Hong Kong for example Hong Kong Hong + + align:start position:0% +of Hong Kong for example Hong Kong Hong + + + align:start position:0% +of Hong Kong for example Hong Kong Hong +Kong first of all is not subject to + + align:start position:0% +Kong first of all is not subject to + + + align:start position:0% +Kong first of all is not subject to +speculative that because they have + + align:start position:0% +speculative that because they have + + + align:start position:0% +speculative that because they have +massive amount of reserves so anyone + + align:start position:0% +massive amount of reserves so anyone + + + align:start position:0% +massive amount of reserves so anyone +that dares attacking them is going to + + align:start position:0% +that dares attacking them is going to + + + align:start position:0% +that dares attacking them is going to +lose their share so so they're safe er + + align:start position:0% +lose their share so so they're safe er + + + align:start position:0% +lose their share so so they're safe er +um Soros tried many years back and he + + align:start position:0% +um Soros tried many years back and he + + + align:start position:0% +um Soros tried many years back and he +didn't do as well as he did attacking + + align:start position:0% +didn't do as well as he did attacking + + + align:start position:0% +didn't do as well as he did attacking +the British pound er um then then but + + align:start position:0% +the British pound er um then then but + + + align:start position:0% +the British pound er um then then but +they also have lots of fiscal resources + + align:start position:0% +they also have lots of fiscal resources + + + align:start position:0% +they also have lots of fiscal resources +so they can fight their domestic + + align:start position:0% +so they can fight their domestic + + + align:start position:0% +so they can fight their domestic +recessions and so on with fiscal policy + + align:start position:0% +recessions and so on with fiscal policy + + + align:start position:0% +recessions and so on with fiscal policy +the other factor which also applies to + + align:start position:0% +the other factor which also applies to + + + align:start position:0% +the other factor which also applies to +Hong Kong if you have very flexible + + align:start position:0% +Hong Kong if you have very flexible + + + align:start position:0% +Hong Kong if you have very flexible +factor market so if wages move very + + align:start position:0% +factor market so if wages move very + + + align:start position:0% +factor market so if wages move very +easily if prices move very easily + + align:start position:0% +easily if prices move very easily + + + align:start position:0% +easily if prices move very easily +domestically then you don't care about + + align:start position:0% +domestically then you don't care about + + + align:start position:0% +domestically then you don't care about +having a fixed nominal exchange rate + + align:start position:0% +having a fixed nominal exchange rate + + + align:start position:0% +having a fixed nominal exchange rate +because a fixed nominal exchange rate is + + align:start position:0% +because a fixed nominal exchange rate is + + + align:start position:0% +because a fixed nominal exchange rate is +not the same as a fixed real exchange + + align:start position:0% +not the same as a fixed real exchange + + + align:start position:0% +not the same as a fixed real exchange +rate which is what you really need to + + align:start position:0% +rate which is what you really need to + + + align:start position:0% +rate which is what you really need to +move around + + align:start position:0% +move around + + + align:start position:0% +move around +if your prices are flexible doesn't + + align:start position:0% +if your prices are flexible doesn't + + + align:start position:0% +if your prices are flexible doesn't +matter that the nominal exchange doesn't + + align:start position:0% +matter that the nominal exchange doesn't + + + align:start position:0% +matter that the nominal exchange doesn't +move because the prices are moving + + align:start position:0% +move because the prices are moving + + + align:start position:0% +move because the prices are moving +around and so you you still have lots of + + align:start position:0% +around and so you you still have lots of + + + align:start position:0% +around and so you you still have lots of +flexibility in the real exchange and + + align:start position:0% +flexibility in the real exchange and + + + align:start position:0% +flexibility in the real exchange and +that's the reason I would say is one of + + align:start position:0% +that's the reason I would say is one of + + + align:start position:0% +that's the reason I would say is one of +the reasons political reasons as well + + align:start position:0% +the reasons political reasons as well + + + align:start position:0% +the reasons political reasons as well +but but why they can afford it why I + + align:start position:0% +but but why they can afford it why I + + + align:start position:0% +but but why they can afford it why I +think in the case of H way around was + + align:start position:0% +think in the case of H way around was + + + align:start position:0% +think in the case of H way around was +some political + + align:start position:0% +some political + + + align:start position:0% +some political +reasons and and and and then they build + + align:start position:0% +reasons and and and and then they build + + + align:start position:0% +reasons and and and and then they build +a system so that it's it's a it's a + + align:start position:0% +a system so that it's it's a it's a + + + align:start position:0% +a system so that it's it's a it's a +coherent system because they have lots + + align:start position:0% +coherent system because they have lots + + + align:start position:0% +coherent system because they have lots +of fiscal capacity can defend the + + align:start position:0% +of fiscal capacity can defend the + + + align:start position:0% +of fiscal capacity can defend the +currency well they have very flexible + + align:start position:0% + + + + align:start position:0% + +Market + + align:start position:0% +Market + + + align:start position:0% +Market +um this well this again this is what I + + align:start position:0% +um this well this again this is what I + + + align:start position:0% +um this well this again this is what I +said before if you if you if this is + + align:start position:0% +said before if you if you if this is + + + align:start position:0% +said before if you if you if this is +what I said before if you if you have + + align:start position:0% +what I said before if you if you have + + + align:start position:0% +what I said before if you if you have +you don't like that noise if you + + align:start position:0% +you don't like that noise if you + + + align:start position:0% +you don't like that noise if you +especially if you're going to be trading + + align:start position:0% +especially if you're going to be trading + + + align:start position:0% +especially if you're going to be trading +a lot with people and so on you know in + + align:start position:0% +a lot with people and so on you know in + + + align:start position:0% +a lot with people and so on you know in +Europe many people cross the border many + + align:start position:0% +Europe many people cross the border many + + + align:start position:0% +Europe many people cross the border many +times a day and you want to go shopping + + align:start position:0% +times a day and you want to go shopping + + + align:start position:0% +times a day and you want to go shopping +one way or the other it's a it's a pain + + align:start position:0% +one way or the other it's a it's a pain + + + align:start position:0% +one way or the other it's a it's a pain +if the exchange is moving all the time + + align:start position:0% +if the exchange is moving all the time + + + align:start position:0% +if the exchange is moving all the time +no it's much easier if things are table + + align:start position:0% +no it's much easier if things are table + + + align:start position:0% +no it's much easier if things are table +and the same appli to financial + + align:start position:0% +and the same appli to financial + + + align:start position:0% +and the same appli to financial +transactions people have deposits in + + align:start position:0% +transactions people have deposits in + + + align:start position:0% +transactions people have deposits in +different banks and stuff like that it's + + align:start position:0% +different banks and stuff like that it's + + + align:start position:0% +different banks and stuff like that it's +it's better if you don't have all that + + align:start position:0% +it's better if you don't have all that + + + align:start position:0% +it's better if you don't have all that +fluctuation and in the case of the Euro + + align:start position:0% +fluctuation and in the case of the Euro + + + align:start position:0% +fluctuation and in the case of the Euro +area they decided that ER that the + + align:start position:0% +area they decided that ER that the + + + align:start position:0% +area they decided that ER that the +advantage of having a very fixed + + align:start position:0% +advantage of having a very fixed + + + align:start position:0% +advantage of having a very fixed +exchange + + align:start position:0% +exchange + + + align:start position:0% +exchange +rate were more than the cost for + + align:start position:0% +rate were more than the cost for + + + align:start position:0% +rate were more than the cost for +individual countries of not having + + align:start position:0% +individual countries of not having + + + align:start position:0% +individual countries of not having +independent monetary + + align:start position:0% +independent monetary + + + align:start position:0% +independent monetary +policy this still a work in progress + + align:start position:0% +policy this still a work in progress + + + align:start position:0% +policy this still a work in progress +they're building that is not + + align:start position:0% +they're building that is not + + + align:start position:0% +they're building that is not +finished but but but they're working at + + align:start position:0% +finished but but but they're working at + + + align:start position:0% +finished but but but they're working at +it there another reason why countries + + align:start position:0% +it there another reason why countries + + + align:start position:0% +it there another reason why countries +fix exchange rate and that's the + + align:start position:0% +fix exchange rate and that's the + + + align:start position:0% +fix exchange rate and that's the +Argentinian reason and so on is is when + + align:start position:0% +Argentinian reason and so on is is when + + + align:start position:0% +Argentinian reason and so on is is when +when they have no control in inflation + + align:start position:0% +when they have no control in inflation + + + align:start position:0% +when they have no control in inflation +they have no credibility and so if you + + align:start position:0% +they have no credibility and so if you + + + align:start position:0% +they have no credibility and so if you +pck to another currency that has + + align:start position:0% +pck to another currency that has + + + align:start position:0% +pck to another currency that has +credibility then the idea the hope at + + align:start position:0% +credibility then the idea the hope at + + + align:start position:0% +credibility then the idea the hope at +least is that you will inherit the + + align:start position:0% +least is that you will inherit the + + + align:start position:0% +least is that you will inherit the +credibility of the other currency and + + align:start position:0% +credibility of the other currency and + + + align:start position:0% +credibility of the other currency and +that's what they try + + align:start position:0% +that's what they try + + + align:start position:0% +that's what they try +to Argentina had a currency board like + + align:start position:0% +to Argentina had a currency board like + + + align:start position:0% +to Argentina had a currency board like +Hong Kong for a while the whole idea was + + align:start position:0% +Hong Kong for a while the whole idea was + + + align:start position:0% +Hong Kong for a while the whole idea was +to control inflation well let's ECT to + + align:start position:0% +to control inflation well let's ECT to + + + align:start position:0% +to control inflation well let's ECT to +someone and and and if they if the + + align:start position:0% +someone and and and if they if the + + + align:start position:0% +someone and and and if they if the +markets believe you then it will work + + align:start position:0% +markets believe you then it will work + + + align:start position:0% +markets believe you then it will work +because then you inherit the The + + align:start position:0% +because then you inherit the The + + + align:start position:0% +because then you inherit the The +credibility of the you're saying when + + align:start position:0% +credibility of the you're saying when + + + align:start position:0% +credibility of the you're saying when +you take a fixed exchange it I'm not + + align:start position:0% +you take a fixed exchange it I'm not + + + align:start position:0% +you take a fixed exchange it I'm not +going to run monetary policy which is + + align:start position:0% +going to run monetary policy which is + + + align:start position:0% +going to run monetary policy which is +the main source of inflation so I'm + + align:start position:0% +the main source of inflation so I'm + + + align:start position:0% +the main source of inflation so I'm +going to let the credible country run + + align:start position:0% +going to let the credible country run + + + align:start position:0% +going to let the credible country run +the monetary policy for me that's what + + align:start position:0% +the monetary policy for me that's what + + + align:start position:0% +the monetary policy for me that's what +gives you credibility as long as + + align:start position:0% +gives you credibility as long as + + + align:start position:0% +gives you credibility as long as +somebody believes it you're not going to + + align:start position:0% +somebody believes it you're not going to + + + align:start position:0% +somebody believes it you're not going to +quit the thing but but but that's the + + align:start position:0% +quit the thing but but but that's the + + + align:start position:0% +quit the thing but but but that's the +reason countries do it often to + + align:start position:0% +reason countries do it often to + + + align:start position:0% +reason countries do it often to +stabilize inflation as + + align:start position:0% +stabilize inflation as + + + align:start position:0% +stabilize inflation as +well for \ No newline at end of file diff --git a/8Ji3Gkjqo5M.txt b/8Ji3Gkjqo5M.txt new file mode 100644 index 0000000000000000000000000000000000000000..e8d7ce2edf3372c6f05a8a467480036793fcc93e --- /dev/null +++ b/8Ji3Gkjqo5M.txt @@ -0,0 +1,10698 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit MIT opencourseware + + align:start position:0% +of MIT courses visit MIT opencourseware + + + align:start position:0% +of MIT courses visit MIT opencourseware +at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu okay uh this is the next + + align:start position:0% +ocw.mit.edu okay uh this is the next + + + align:start position:0% +ocw.mit.edu okay uh this is the next +little last lecture you'll be happy to + + align:start position:0% +little last lecture you'll be happy to + + + align:start position:0% +little last lecture you'll be happy to +know uh and today we're going to talk + + align:start position:0% +know uh and today we're going to talk + + + align:start position:0% +know uh and today we're going to talk +about current regulatory safety issues I + + align:start position:0% +about current regulatory safety issues I + + + align:start position:0% +about current regulatory safety issues I +thought it would be really important for + + align:start position:0% +thought it would be really important for + + + align:start position:0% +thought it would be really important for +you to catch up on what the NRC thinks + + align:start position:0% +you to catch up on what the NRC thinks + + + align:start position:0% +you to catch up on what the NRC thinks +is important these days as it relates to + + align:start position:0% +is important these days as it relates to + + + align:start position:0% +is important these days as it relates to +their safety and Regulatory + + align:start position:0% +their safety and Regulatory + + + align:start position:0% +their safety and Regulatory +function so we're going to try to cover + + align:start position:0% +function so we're going to try to cover + + + align:start position:0% +function so we're going to try to cover +a few things relatively quickly and I + + align:start position:0% +a few things relatively quickly and I + + + align:start position:0% +a few things relatively quickly and I +went to the NRC website and I said what + + align:start position:0% +went to the NRC website and I said what + + + align:start position:0% +went to the NRC website and I said what +are your key current issues and the list + + align:start position:0% +are your key current issues and the list + + + align:start position:0% +are your key current issues and the list +is reactor vessel Integrity which as as + + align:start position:0% +is reactor vessel Integrity which as as + + + align:start position:0% +is reactor vessel Integrity which as as +you probably realize is now reactor + + align:start position:0% +you probably realize is now reactor + + + align:start position:0% +you probably realize is now reactor +vessel in berin pressurized water + + align:start position:0% +vessel in berin pressurized water + + + align:start position:0% +vessel in berin pressurized water +reactor some pump performance we'll look + + align:start position:0% +reactor some pump performance we'll look + + + align:start position:0% +reactor some pump performance we'll look +at that many of these issues have been + + align:start position:0% +at that many of these issues have been + + + align:start position:0% +at that many of these issues have been +around for 20 + + align:start position:0% +around for 20 + + + align:start position:0% +around for 20 +years but they're still there the + + align:start position:0% +years but they're still there the + + + align:start position:0% +years but they're still there the +reactor coolant system weld issues they + + align:start position:0% +reactor coolant system weld issues they + + + align:start position:0% +reactor coolant system weld issues they +used uh and they're getting primary + + align:start position:0% +used uh and they're getting primary + + + align:start position:0% +used uh and they're getting primary +water stress corrosion cracking we've + + align:start position:0% +water stress corrosion cracking we've + + + align:start position:0% +water stress corrosion cracking we've +already talked about Davis Bessie head + + align:start position:0% +already talked about Davis Bessie head + + + align:start position:0% +already talked about Davis Bessie head +degradation so we're not going to talk + + align:start position:0% +degradation so we're not going to talk + + + align:start position:0% +degradation so we're not going to talk +about that but that's certainly related + + align:start position:0% +about that but that's certainly related + + + align:start position:0% +about that but that's certainly related +to uh certain weld issues we've never + + align:start position:0% +to uh certain weld issues we've never + + + align:start position:0% +to uh certain weld issues we've never +really talked about fire protection the + + align:start position:0% +really talked about fire protection the + + + align:start position:0% +really talked about fire protection the +fire protection is an old old + + align:start position:0% +fire protection is an old old + + + align:start position:0% +fire protection is an old old +rule uh that uh will briefly review and + + align:start position:0% +rule uh that uh will briefly review and + + + align:start position:0% +rule uh that uh will briefly review and +they've got some issues now with some + + align:start position:0% +they've got some issues now with some + + + align:start position:0% +they've got some issues now with some +insulation that doesn't meet certain + + align:start position:0% +insulation that doesn't meet certain + + + align:start position:0% +insulation that doesn't meet certain +standards and it's a difficult question + + align:start position:0% +standards and it's a difficult question + + + align:start position:0% +standards and it's a difficult question +for them and obviously the new issue + + align:start position:0% +for them and obviously the new issue + + + align:start position:0% +for them and obviously the new issue +since 9911 is planed security and + + align:start position:0% +since 9911 is planed security and + + + align:start position:0% +since 9911 is planed security and +terrorism uh we've seen some recent + + align:start position:0% +terrorism uh we've seen some recent + + + align:start position:0% +terrorism uh we've seen some recent +evidence of groundw contamination + + align:start position:0% +evidence of groundw contamination + + + align:start position:0% +evidence of groundw contamination +Mainely in the traum case and based on + + align:start position:0% +Mainely in the traum case and based on + + + align:start position:0% +Mainely in the traum case and based on +our last lecture I thought it' be good + + align:start position:0% +our last lecture I thought it' be good + + + align:start position:0% +our last lecture I thought it' be good +to update you on what they call the saf + + align:start position:0% +to update you on what they call the saf + + + align:start position:0% +to update you on what they call the saf +conscious work environment as a safety + + align:start position:0% +conscious work environment as a safety + + + align:start position:0% +conscious work environment as a safety +culture + + align:start position:0% +culture + + + align:start position:0% +culture +question so we'll go through them sort + + align:start position:0% +question so we'll go through them sort + + + align:start position:0% +question so we'll go through them sort +of one by + + align:start position:0% +of one by + + + align:start position:0% +of one by +one um the reactor vessel Integrity + + align:start position:0% +one um the reactor vessel Integrity + + + align:start position:0% +one um the reactor vessel Integrity +issue was in part driven by Yankee + + align:start position:0% +issue was in part driven by Yankee + + + align:start position:0% +issue was in part driven by Yankee +Atomic the Yankee Ro plant now what + + align:start position:0% +Atomic the Yankee Ro plant now what + + + align:start position:0% +Atomic the Yankee Ro plant now what +happened at Yankee was that when the + + align:start position:0% +happened at Yankee was that when the + + + align:start position:0% +happened at Yankee was that when the +Yankee plant was built back in the N + + align:start position:0% +Yankee plant was built back in the N + + + align:start position:0% +Yankee plant was built back in the N +late 50s each reactor was supposed to + + align:start position:0% +late 50s each reactor was supposed to + + + align:start position:0% +late 50s each reactor was supposed to +install a surveillance capsule of the + + align:start position:0% +install a surveillance capsule of the + + + align:start position:0% +install a surveillance capsule of the +material that the reactor vessel is made + + align:start position:0% +material that the reactor vessel is made + + + align:start position:0% +material that the reactor vessel is made +of and the material that the wells are + + align:start position:0% +of and the material that the wells are + + + align:start position:0% +of and the material that the wells are +made up and it's all very carefully + + align:start position:0% +made up and it's all very carefully + + + align:start position:0% +made up and it's all very carefully +tracked and monitored but in those days + + align:start position:0% +tracked and monitored but in those days + + + align:start position:0% +tracked and monitored but in those days +in the + + align:start position:0% +in the + + + align:start position:0% +in the +50s um they weren't so scrupulous about + + align:start position:0% +50s um they weren't so scrupulous about + + + align:start position:0% +50s um they weren't so scrupulous about +making sure the capsules were the + + align:start position:0% +making sure the capsules were the + + + align:start position:0% +making sure the capsules were the +original vessel capsules and the well + + align:start position:0% +original vessel capsules and the well + + + align:start position:0% +original vessel capsules and the well +material was the original vessel + + align:start position:0% +material was the original vessel + + + align:start position:0% +material was the original vessel +material but luckily for Yankee at the + + align:start position:0% +material but luckily for Yankee at the + + + align:start position:0% +material but luckily for Yankee at the +time they did put capsules in and they + + align:start position:0% +time they did put capsules in and they + + + align:start position:0% +time they did put capsules in and they +did put weld capsules as well but + + align:start position:0% +did put weld capsules as well but + + + align:start position:0% +did put weld capsules as well but +unfortunately during the first or second + + align:start position:0% +unfortunately during the first or second + + + align:start position:0% +unfortunately during the first or second +year of operation the capsules were + + align:start position:0% +year of operation the capsules were + + + align:start position:0% +year of operation the capsules were +destroyed in other words the hold the + + align:start position:0% +destroyed in other words the hold the + + + align:start position:0% +destroyed in other words the hold the +holders cell uh broke and they they were + + align:start position:0% +holders cell uh broke and they they were + + + align:start position:0% +holders cell uh broke and they they were +able to retrieve some and they had + + align:start position:0% +able to retrieve some and they had + + + align:start position:0% +able to retrieve some and they had +limited amount of data upon which to + + align:start position:0% +limited amount of data upon which to + + + align:start position:0% +limited amount of data upon which to +base predictions and the way they made + + align:start position:0% +base predictions and the way they made + + + align:start position:0% +base predictions and the way they made +these predictions was they put them very + + align:start position:0% +these predictions was they put them very + + + align:start position:0% +these predictions was they put them very +close to the core and over a period of + + align:start position:0% +close to the core and over a period of + + + align:start position:0% +close to the core and over a period of +time they would take out specimens and + + align:start position:0% +time they would take out specimens and + + + align:start position:0% +time they would take out specimens and +determine what the degree of umbr it was + + align:start position:0% +determine what the degree of umbr it was + + + align:start position:0% +determine what the degree of umbr it was +and Yankee we had a number of specimens + + align:start position:0% +and Yankee we had a number of specimens + + + align:start position:0% +and Yankee we had a number of specimens +early in life and we had one really late + + align:start position:0% +early in life and we had one really late + + + align:start position:0% +early in life and we had one really late +in life and you couldn't really just + + align:start position:0% +in life and you couldn't really just + + + align:start position:0% +in life and you couldn't really just +draw a straight line curve to it but + + align:start position:0% +draw a straight line curve to it but + + + align:start position:0% +draw a straight line curve to it but +most reactors and pretty much all + + align:start position:0% +most reactors and pretty much all + + + align:start position:0% +most reactors and pretty much all +reactors today have these in incor + + align:start position:0% +reactors today have these in incor + + + align:start position:0% +reactors today have these in incor +specimens that they use to to determine + + align:start position:0% +specimens that they use to to determine + + + align:start position:0% +specimens that they use to to determine +whether or not the vessel is becoming + + align:start position:0% +whether or not the vessel is becoming + + + align:start position:0% +whether or not the vessel is becoming +overly embed and typically these are + + align:start position:0% +overly embed and typically these are + + + align:start position:0% +overly embed and typically these are +these are these are specimens in which + + align:start position:0% +these are these are specimens in which + + + align:start position:0% +these are these are specimens in which +the uh they're located in a place in the + + align:start position:0% +the uh they're located in a place in the + + + align:start position:0% +the uh they're located in a place in the +core a number places in the core where + + align:start position:0% +core a number places in the core where + + + align:start position:0% +core a number places in the core where +they can get IR radiations uh over time + + align:start position:0% +they can get IR radiations uh over time + + + align:start position:0% +they can get IR radiations uh over time +so what we what we have had at Yankee + + align:start position:0% +so what we what we have had at Yankee + + + align:start position:0% +so what we what we have had at Yankee +was that we were trying to go for a + + align:start position:0% +was that we were trying to go for a + + + align:start position:0% +was that we were trying to go for a +license renewal and one of the justif + + align:start position:0% +license renewal and one of the justif + + + align:start position:0% +license renewal and one of the justif +for continuing to operate past 40 Years + + align:start position:0% +for continuing to operate past 40 Years + + + align:start position:0% +for continuing to operate past 40 Years +of operation was that we need to show + + align:start position:0% +of operation was that we need to show + + + align:start position:0% +of operation was that we need to show +The Vessel with sound well in our + + align:start position:0% +The Vessel with sound well in our + + + align:start position:0% +The Vessel with sound well in our +attempt to try to defend it and + + align:start position:0% +attempt to try to defend it and + + + align:start position:0% +attempt to try to defend it and +obviously it depends on the well + + align:start position:0% +obviously it depends on the well + + + align:start position:0% +obviously it depends on the well +material and the metal because some of + + align:start position:0% +material and the metal because some of + + + align:start position:0% +material and the metal because some of +them depends upon your Chemistry of the + + align:start position:0% +them depends upon your Chemistry of the + + + align:start position:0% +them depends upon your Chemistry of the +metal you have more or less + + align:start position:0% +metal you have more or less + + + align:start position:0% +metal you have more or less +susceptibility to embrittlement and as I + + align:start position:0% +susceptibility to embrittlement and as I + + + align:start position:0% +susceptibility to embrittlement and as I +recall it was copper content and some + + align:start position:0% +recall it was copper content and some + + + align:start position:0% +recall it was copper content and some +nickel content and basically it it was + + align:start position:0% +nickel content and basically it it was + + + align:start position:0% +nickel content and basically it it was +very very very key to be able to + + align:start position:0% +very very very key to be able to + + + align:start position:0% +very very very key to be able to +understand what the vessel was in fact + + align:start position:0% +understand what the vessel was in fact + + + align:start position:0% +understand what the vessel was in fact +made of because the performance was + + align:start position:0% +made of because the performance was + + + align:start position:0% +made of because the performance was +significantly different well what + + align:start position:0% +significantly different well what + + + align:start position:0% +significantly different well what +happened at Yankee was we we spent + + align:start position:0% +happened at Yankee was we we spent + + + align:start position:0% +happened at Yankee was we we spent +probably over two years trying to + + align:start position:0% +probably over two years trying to + + + align:start position:0% +probably over two years trying to +convince the NRC that our vessel was + + align:start position:0% +convince the NRC that our vessel was + + + align:start position:0% +convince the NRC that our vessel was +fine based on the limited data that we + + align:start position:0% +fine based on the limited data that we + + + align:start position:0% +fine based on the limited data that we +had luckily for us we had a reactor in + + align:start position:0% +had luckily for us we had a reactor in + + + align:start position:0% +had luckily for us we had a reactor in +Belgium that was in fact also made of + + align:start position:0% +Belgium that was in fact also made of + + + align:start position:0% +Belgium that was in fact also made of +about the same time of the same type of + + align:start position:0% +about the same time of the same type of + + + align:start position:0% +about the same time of the same type of +metal and we had their radiation andent + + align:start position:0% +metal and we had their radiation andent + + + align:start position:0% +metal and we had their radiation andent +data the net result was the NRC didn't + + align:start position:0% +data the net result was the NRC didn't + + + align:start position:0% +data the net result was the NRC didn't +buy our + + align:start position:0% +buy our + + + align:start position:0% +buy our +story and + + align:start position:0% +story and + + + align:start position:0% +story and +um and and the key parameters basically + + align:start position:0% +um and and the key parameters basically + + + align:start position:0% +um and and the key parameters basically +that you have to look at is this uh n + + align:start position:0% +that you have to look at is this uh n + + + align:start position:0% +that you have to look at is this uh n +ductility transition temperature which I + + align:start position:0% +ductility transition temperature which I + + + align:start position:0% +ductility transition temperature which I +know you haven't had material so you + + align:start position:0% +know you haven't had material so you + + + align:start position:0% +know you haven't had material so you +wouldn't understand but it's a point + + align:start position:0% +wouldn't understand but it's a point + + + align:start position:0% +wouldn't understand but it's a point +after which at certain temperatures the + + align:start position:0% +after which at certain temperatures the + + + align:start position:0% +after which at certain temperatures the +reactor will uh lose a lot of its + + align:start position:0% +reactor will uh lose a lot of its + + + align:start position:0% +reactor will uh lose a lot of its +strength and in fact if you shock it + + align:start position:0% +strength and in fact if you shock it + + + align:start position:0% +strength and in fact if you shock it +under uh with cold water there a poti I + + align:start position:0% +under uh with cold water there a poti I + + + align:start position:0% +under uh with cold water there a poti I +should there be a flaw or crack in the + + align:start position:0% +should there be a flaw or crack in the + + + align:start position:0% +should there be a flaw or crack in the +vessel The Vessel can crack propagate + + align:start position:0% +vessel The Vessel can crack propagate + + + align:start position:0% +vessel The Vessel can crack propagate +that crack and that's why the NRC was + + align:start position:0% +that crack and that's why the NRC was + + + align:start position:0% +that crack and that's why the NRC was +really anxious about this particular + + align:start position:0% +really anxious about this particular + + + align:start position:0% +really anxious about this particular +event um and and the concern was and I + + align:start position:0% +event um and and the concern was and I + + + align:start position:0% +event um and and the concern was and I +believe we talked about it once in class + + align:start position:0% +believe we talked about it once in class + + + align:start position:0% +believe we talked about it once in class +the issue was what we + + align:start position:0% + + + + align:start position:0% + +call + + align:start position:0% + + + + align:start position:0% + +pressurized thermal shock + + align:start position:0% + + + + align:start position:0% + +and and that that that phenomenon was if + + align:start position:0% +and and that that that phenomenon was if + + + align:start position:0% +and and that that that phenomenon was if +you're under high pressure say 2200 + + align:start position:0% +you're under high pressure say 2200 + + + align:start position:0% +you're under high pressure say 2200 +lb and you hit a hot + + align:start position:0% + + + + align:start position:0% + +vessel with cold water cold water being + + align:start position:0% +vessel with cold water cold water being + + + align:start position:0% +vessel with cold water cold water being +you know ambient temperature water like + + align:start position:0% +you know ambient temperature water like + + + align:start position:0% +you know ambient temperature water like +from the refueling storage pool which is + + align:start position:0% +from the refueling storage pool which is + + + align:start position:0% +from the refueling storage pool which is +obviously not this hot it could be + + align:start position:0% +obviously not this hot it could be + + + align:start position:0% +obviously not this hot it could be +typically um on the order of uh let's + + align:start position:0% +typically um on the order of uh let's + + + align:start position:0% +typically um on the order of uh let's +just say 60° + + align:start position:0% +just say 60° + + + align:start position:0% +just say 60° +F if there is a pre-existing flaw that + + align:start position:0% +F if there is a pre-existing flaw that + + + align:start position:0% +F if there is a pre-existing flaw that +shock would in fact cause that flaw to + + align:start position:0% +shock would in fact cause that flaw to + + + align:start position:0% +shock would in fact cause that flaw to +grow possibly rupturing The Vessel + + align:start position:0% +grow possibly rupturing The Vessel + + + align:start position:0% +grow possibly rupturing The Vessel +possibly rupturing The + + align:start position:0% +possibly rupturing The + + + align:start position:0% +possibly rupturing The +Vessel some compensatory actions that we + + align:start position:0% +Vessel some compensatory actions that we + + + align:start position:0% +Vessel some compensatory actions that we +had to take were and this is the eccs + + align:start position:0% +had to take were and this is the eccs + + + align:start position:0% +had to take were and this is the eccs +water that we rais this temperature to + + align:start position:0% +water that we rais this temperature to + + + align:start position:0% +water that we rais this temperature to +120° so that the shock would be less + + align:start position:0% +120° so that the shock would be less + + + align:start position:0% +120° so that the shock would be less +severe and um we showed + + align:start position:0% + + + + align:start position:0% + +probabilistically that the likelihood of + + align:start position:0% +probabilistically that the likelihood of + + + align:start position:0% +probabilistically that the likelihood of +the event given this design of our + + align:start position:0% +the event given this design of our + + + align:start position:0% +the event given this design of our +system and given the failure rates of + + align:start position:0% +system and given the failure rates of + + + align:start position:0% +system and given the failure rates of +these certain compounds would be low + + align:start position:0% +these certain compounds would be low + + + align:start position:0% +these certain compounds would be low +enough such that the event was like a 10 + + align:start position:0% +enough such that the event was like a 10 + + + align:start position:0% +enough such that the event was like a 10 +Theus 8 probability event but this was + + align:start position:0% +Theus 8 probability event but this was + + + align:start position:0% +Theus 8 probability event but this was +before the days of + + align:start position:0% +before the days of + + + align:start position:0% +before the days of +P Acceptance in the regulatory process + + align:start position:0% +P Acceptance in the regulatory process + + + align:start position:0% +P Acceptance in the regulatory process +but after all the s and done we were + + align:start position:0% +but after all the s and done we were + + + align:start position:0% +but after all the s and done we were +committing to inspections of the vessel + + align:start position:0% +committing to inspections of the vessel + + + align:start position:0% +committing to inspections of the vessel +to see if there's any calculated flaw LA + + align:start position:0% +to see if there's any calculated flaw LA + + + align:start position:0% +to see if there's any calculated flaw LA +but at that point we were going to spend + + align:start position:0% +but at that point we were going to spend + + + align:start position:0% +but at that point we were going to spend +roughly in those days $28 + + align:start position:0% +roughly in those days $28 + + + align:start position:0% +roughly in those days $28 +million to do a vessel + + align:start position:0% +million to do a vessel + + + align:start position:0% +million to do a vessel +inspection and additional + + align:start position:0% +inspection and additional + + + align:start position:0% +inspection and additional +testing uh for a license renewal of 20 + + align:start position:0% +testing uh for a license renewal of 20 + + + align:start position:0% +testing uh for a license renewal of 20 +years and there was no Assurance from + + align:start position:0% +years and there was no Assurance from + + + align:start position:0% +years and there was no Assurance from +the NRC that we'd actually be able to + + align:start position:0% +the NRC that we'd actually be able to + + + align:start position:0% +the NRC that we'd actually be able to +convince them that this is not a problem + + align:start position:0% +convince them that this is not a problem + + + align:start position:0% +convince them that this is not a problem +interestingly enough + + align:start position:0% +interestingly enough + + + align:start position:0% +interestingly enough +subsequently um the The Regulators did + + align:start position:0% +subsequently um the The Regulators did + + + align:start position:0% +subsequently um the The Regulators did +accept our but at that point was much + + align:start position:0% +accept our but at that point was much + + + align:start position:0% +accept our but at that point was much +too late to save the Ane plan so we shut + + align:start position:0% +too late to save the Ane plan so we shut + + + align:start position:0% +too late to save the Ane plan so we shut +it + + align:start position:0% +it + + + align:start position:0% +it +down but there's a lot of documentation + + align:start position:0% +down but there's a lot of documentation + + + align:start position:0% +down but there's a lot of documentation +there's this generic + + align:start position:0% +there's this generic + + + align:start position:0% +there's this generic +letter uh generic letter + + align:start position:0% +letter uh generic letter + + + align:start position:0% +letter uh generic letter +9201 you want some history on the + + align:start position:0% +9201 you want some history on the + + + align:start position:0% +9201 you want some history on the +case and um obviously there are lot lots + + align:start position:0% +case and um obviously there are lot lots + + + align:start position:0% +case and um obviously there are lot lots +of other correspondence between yankee + + align:start position:0% +of other correspondence between yankee + + + align:start position:0% +of other correspondence between yankee +and the + + align:start position:0% +and the + + + align:start position:0% +and the +um the + + align:start position:0% +um the + + + align:start position:0% +um the +regulator but this is sort of the if you + + align:start position:0% +regulator but this is sort of the if you + + + align:start position:0% +regulator but this is sort of the if you +want to get more information on it + + align:start position:0% +want to get more information on it + + + align:start position:0% +want to get more information on it +that's a good place to start you could + + align:start position:0% +that's a good place to start you could + + + align:start position:0% +that's a good place to start you could +search um it was a difficult time for us + + align:start position:0% +search um it was a difficult time for us + + + align:start position:0% +search um it was a difficult time for us +a lot of reactors uh also had similar + + align:start position:0% +a lot of reactors uh also had similar + + + align:start position:0% +a lot of reactors uh also had similar +situations and they had to do a lot of + + align:start position:0% +situations and they had to do a lot of + + + align:start position:0% +situations and they had to do a lot of +vessel inspections identifying a lot of + + align:start position:0% +vessel inspections identifying a lot of + + + align:start position:0% +vessel inspections identifying a lot of +fracture toughness and I think if our + + align:start position:0% +fracture toughness and I think if our + + + align:start position:0% +fracture toughness and I think if our +department does a material science + + align:start position:0% +department does a material science + + + align:start position:0% +department does a material science +course for undergrads this is some this + + align:start position:0% +course for undergrads this is some this + + + align:start position:0% +course for undergrads this is some this +is going to be a major issue but the + + align:start position:0% +is going to be a major issue but the + + + align:start position:0% +is going to be a major issue but the +phenomenon is pressurized thermal shock + + align:start position:0% +phenomenon is pressurized thermal shock + + + align:start position:0% +phenomenon is pressurized thermal shock +in normal conditions you're not + + align:start position:0% +in normal conditions you're not + + + align:start position:0% +in normal conditions you're not +expecting the reactor vessel to fail + + align:start position:0% +expecting the reactor vessel to fail + + + align:start position:0% +expecting the reactor vessel to fail +because it's warm and hot but hit it + + align:start position:0% +because it's warm and hot but hit it + + + align:start position:0% +because it's warm and hot but hit it +with cold water it's a problem some + + align:start position:0% +with cold water it's a problem some + + + align:start position:0% +with cold water it's a problem some +reactors because you know some some of + + align:start position:0% +reactors because you know some some of + + + align:start position:0% +reactors because you know some some of +these reactors want to operate for 60 + + align:start position:0% +these reactors want to operate for 60 + + + align:start position:0% +these reactors want to operate for 60 +years and fluence is a integrated + + align:start position:0% +years and fluence is a integrated + + + align:start position:0% +years and fluence is a integrated +phenomenon so what they've done and this + + align:start position:0% +phenomenon so what they've done and this + + + align:start position:0% +phenomenon so what they've done and this +gets back to our reactor physics and + + align:start position:0% +gets back to our reactor physics and + + + align:start position:0% +gets back to our reactor physics and +they've decided to do low leakage cores + + align:start position:0% +they've decided to do low leakage cores + + + align:start position:0% +they've decided to do low leakage cores +where they managed the core fuel + + align:start position:0% +where they managed the core fuel + + + align:start position:0% +where they managed the core fuel +management such that the amount of + + align:start position:0% +management such that the amount of + + + align:start position:0% +management such that the amount of +neutrons escaping from the reactor + + align:start position:0% +neutrons escaping from the reactor + + + align:start position:0% +neutrons escaping from the reactor +hitting the vessel is reduced so that's + + align:start position:0% +hitting the vessel is reduced so that's + + + align:start position:0% +hitting the vessel is reduced so that's +a major impact on on core design and in + + align:start position:0% +a major impact on on core design and in + + + align:start position:0% +a major impact on on core design and in +fact the reactor vessel is really the + + align:start position:0% +fact the reactor vessel is really the + + + align:start position:0% +fact the reactor vessel is really the +only major life limiting + + align:start position:0% +only major life limiting + + + align:start position:0% +only major life limiting +compound in the whole nuclear power + + align:start position:0% +compound in the whole nuclear power + + + align:start position:0% +compound in the whole nuclear power +plant you can replace turbines you + + align:start position:0% +plant you can replace turbines you + + + align:start position:0% +plant you can replace turbines you +replace condensers replace steam + + align:start position:0% +replace condensers replace steam + + + align:start position:0% +replace condensers replace steam +generators reactor vessel becomes a + + align:start position:0% +generators reactor vessel becomes a + + + align:start position:0% +generators reactor vessel becomes a +little + + align:start position:0% +little + + + align:start position:0% +little +tricky we at Yankee were actually + + align:start position:0% +tricky we at Yankee were actually + + + align:start position:0% +tricky we at Yankee were actually +considering replacing a reactor vessel + + align:start position:0% +considering replacing a reactor vessel + + + align:start position:0% +considering replacing a reactor vessel +and we've done some preliminary studies + + align:start position:0% +and we've done some preliminary studies + + + align:start position:0% +and we've done some preliminary studies +but it became um for a plant of only 185 + + align:start position:0% +but it became um for a plant of only 185 + + + align:start position:0% +but it became um for a plant of only 185 +megaw very difficult to justify but you + + align:start position:0% +megaw very difficult to justify but you + + + align:start position:0% +megaw very difficult to justify but you +theoretically can do it the other thing + + align:start position:0% +theoretically can do it the other thing + + + align:start position:0% +theoretically can do it the other thing +that you can do with this is called a + + align:start position:0% +that you can do with this is called a + + + align:start position:0% +that you can do with this is called a +kneeling and we look very hard at this + + align:start position:0% +kneeling and we look very hard at this + + + align:start position:0% +kneeling and we look very hard at this +concept of + + align:start position:0% +concept of + + + align:start position:0% +concept of +analing and this was done and has been + + align:start position:0% +analing and this was done and has been + + + align:start position:0% +analing and this was done and has been +done in uh reactors I in Russia for sure + + align:start position:0% +done in uh reactors I in Russia for sure + + + align:start position:0% +done in uh reactors I in Russia for sure +and I think in the Belgian reactor + + align:start position:0% +and I think in the Belgian reactor + + + align:start position:0% +and I think in the Belgian reactor +analing is basically taking and heating + + align:start position:0% +analing is basically taking and heating + + + align:start position:0% +analing is basically taking and heating +up the reactor vessel Wells or those + + align:start position:0% +up the reactor vessel Wells or those + + + align:start position:0% +up the reactor vessel Wells or those +heated those those zones where you have + + align:start position:0% +heated those those zones where you have + + + align:start position:0% +heated those those zones where you have +potentially EMB Britt conditions heating + + align:start position:0% +potentially EMB Britt conditions heating + + + align:start position:0% +potentially EMB Britt conditions heating +it up and allowing the material to relax + + align:start position:0% +it up and allowing the material to relax + + + align:start position:0% +it up and allowing the material to relax +and restore some of its original + + align:start position:0% +and restore some of its original + + + align:start position:0% +and restore some of its original +properties and this analing phenomenon + + align:start position:0% +properties and this analing phenomenon + + + align:start position:0% +properties and this analing phenomenon +allowed would could potentially allow + + align:start position:0% +allowed would could potentially allow + + + align:start position:0% +allowed would could potentially allow +you to get 10 more years of operating + + align:start position:0% +you to get 10 more years of operating + + + align:start position:0% +you to get 10 more years of operating +line and then allow it to reate so + + align:start position:0% +line and then allow it to reate so + + + align:start position:0% +line and then allow it to reate so +analing is another solution to reactive + + align:start position:0% +analing is another solution to reactive + + + align:start position:0% +analing is another solution to reactive +vessel Integrity issues if replacement + + align:start position:0% +vessel Integrity issues if replacement + + + align:start position:0% +vessel Integrity issues if replacement +is not an option but it's it's sort of + + align:start position:0% +is not an option but it's it's sort of + + + align:start position:0% +is not an option but it's it's sort of +like it doesn't fully recover and you + + align:start position:0% +like it doesn't fully recover and you + + + align:start position:0% +like it doesn't fully recover and you +need to do it more frequently as as as + + align:start position:0% +need to do it more frequently as as as + + + align:start position:0% +need to do it more frequently as as as +as as the more irradiation damage + + align:start position:0% +as as the more irradiation damage + + + align:start position:0% +as as the more irradiation damage +occurs and so these are some solutions + + align:start position:0% +occurs and so these are some solutions + + + align:start position:0% +occurs and so these are some solutions +that you might want to think about if + + align:start position:0% +that you might want to think about if + + + align:start position:0% +that you might want to think about if +you're ever faced in this + + align:start position:0% +you're ever faced in this + + + align:start position:0% +you're ever faced in this +situation the U the next issue do you + + align:start position:0% +situation the U the next issue do you + + + align:start position:0% +situation the U the next issue do you +have any questions on the reative vessel + + align:start position:0% +have any questions on the reative vessel + + + align:start position:0% +have any questions on the reative vessel +one by way before one it's a lot of a + + align:start position:0% +one by way before one it's a lot of a + + + align:start position:0% +one by way before one it's a lot of a +lot of stuff but I was I was prepared to + + align:start position:0% +lot of stuff but I was I was prepared to + + + align:start position:0% +lot of stuff but I was I was prepared to +give you some some discussions on the + + align:start position:0% +give you some some discussions on the + + + align:start position:0% +give you some some discussions on the +kinds of work that we did do uh to + + align:start position:0% +kinds of work that we did do uh to + + + align:start position:0% +kinds of work that we did do uh to +justify operation if you don't have the + + align:start position:0% +justify operation if you don't have the + + + align:start position:0% +justify operation if you don't have the +the Material Science Background it's pry + + align:start position:0% +the Material Science Background it's pry + + + align:start position:0% +the Material Science Background it's pry +hard to uh to discuss but the two key + + align:start position:0% +hard to uh to discuss but the two key + + + align:start position:0% +hard to uh to discuss but the two key +areas in this in this in this in this + + align:start position:0% +areas in this in this in this in this + + + align:start position:0% +areas in this in this in this in this +discussion is what is the maximum + + align:start position:0% +discussion is what is the maximum + + + align:start position:0% +discussion is what is the maximum +detectable flaw size and given that + + align:start position:0% +detectable flaw size and given that + + + align:start position:0% +detectable flaw size and given that +maximum detectable flaw size should you + + align:start position:0% +maximum detectable flaw size should you + + + align:start position:0% +maximum detectable flaw size should you +have a pts event would the reactive + + align:start position:0% +have a pts event would the reactive + + + align:start position:0% +have a pts event would the reactive +vessel fit or have a crack propagation + + align:start position:0% +vessel fit or have a crack propagation + + + align:start position:0% +vessel fit or have a crack propagation +such that the likelihood failure would + + align:start position:0% +such that the likelihood failure would + + + align:start position:0% +such that the likelihood failure would +be much higher and the inspections that + + align:start position:0% +be much higher and the inspections that + + + align:start position:0% +be much higher and the inspections that +you do inside these reactor vels mean + + align:start position:0% +you do inside these reactor vels mean + + + align:start position:0% +you do inside these reactor vels mean +you take all the fuel out of the reactor + + align:start position:0% +you take all the fuel out of the reactor + + + align:start position:0% +you take all the fuel out of the reactor +vessel and then you do uh uh some kind + + align:start position:0% +vessel and then you do uh uh some kind + + + align:start position:0% +vessel and then you do uh uh some kind +of inspection that will identify what + + align:start position:0% +of inspection that will identify what + + + align:start position:0% +of inspection that will identify what +you consider to be the maximum flaw size + + align:start position:0% +you consider to be the maximum flaw size + + + align:start position:0% +you consider to be the maximum flaw size +and and that that is the key driver and + + align:start position:0% +and and that that is the key driver and + + + align:start position:0% +and and that that is the key driver and +there's all kinds of analysis that you + + align:start position:0% +there's all kinds of analysis that you + + + align:start position:0% +there's all kinds of analysis that you +can do to show with a certain detectable + + align:start position:0% +can do to show with a certain detectable + + + align:start position:0% +can do to show with a certain detectable +fla size this thing is going to be a + + align:start position:0% +fla size this thing is going to be a + + + align:start position:0% +fla size this thing is going to be a +problem or not the other issue is this + + align:start position:0% +problem or not the other issue is this + + + align:start position:0% +problem or not the other issue is this +next issue that I want to talk about is + + align:start position:0% +next issue that I want to talk about is + + + align:start position:0% +next issue that I want to talk about is +some PP + + align:start position:0% +some PP + + + align:start position:0% +some PP +performance now this issue has been + + align:start position:0% +performance now this issue has been + + + align:start position:0% +performance now this issue has been +around found since the late + + align:start position:0% +around found since the late + + + align:start position:0% +around found since the late +1970s all right now why is this a + + align:start position:0% +1970s all right now why is this a + + + align:start position:0% +1970s all right now why is this a +problem well you remember in when we + + align:start position:0% +problem well you remember in when we + + + align:start position:0% +problem well you remember in when we +talked about um the need for + + align:start position:0% +talked about um the need for + + + align:start position:0% +talked about um the need for +recirculation all the water pretty much + + align:start position:0% +recirculation all the water pretty much + + + align:start position:0% +recirculation all the water pretty much +comes down into the lower uh containment + + align:start position:0% +comes down into the lower uh containment + + + align:start position:0% +comes down into the lower uh containment +section and is pumped back into either + + align:start position:0% +section and is pumped back into either + + + align:start position:0% +section and is pumped back into either +the core spray system or back into the + + align:start position:0% +the core spray system or back into the + + + align:start position:0% +the core spray system or back into the +reactor but when you have this stuff + + align:start position:0% +reactor but when you have this stuff + + + align:start position:0% +reactor but when you have this stuff +going on especially in the containment + + align:start position:0% +going on especially in the containment + + + align:start position:0% +going on especially in the containment +sprays or maybe in the major pipe Rak + + align:start position:0% +sprays or maybe in the major pipe Rak + + + align:start position:0% +sprays or maybe in the major pipe Rak +you you potentially can lose a lot of + + align:start position:0% +you you potentially can lose a lot of + + + align:start position:0% +you you potentially can lose a lot of +insulation a lot of debris ultimately + + align:start position:0% +insulation a lot of debris ultimately + + + align:start position:0% +insulation a lot of debris ultimately +end up in the bottom of the + + align:start position:0% +end up in the bottom of the + + + align:start position:0% +end up in the bottom of the +sun and it originally started with + + align:start position:0% +sun and it originally started with + + + align:start position:0% +sun and it originally started with +pressure with boiling water reactors + + align:start position:0% +pressure with boiling water reactors + + + align:start position:0% +pressure with boiling water reactors +back in the late late um + + align:start position:0% +back in the late late um + + + align:start position:0% +back in the late late um +1970s where they have for these pumps + + align:start position:0% +1970s where they have for these pumps + + + align:start position:0% +1970s where they have for these pumps +they had debris screens and the debris + + align:start position:0% +they had debris screens and the debris + + + align:start position:0% +they had debris screens and the debris +screens were were were intended to keep + + align:start position:0% +screens were were were intended to keep + + + align:start position:0% +screens were were were intended to keep +the debris from damaging the + + align:start position:0% +the debris from damaging the + + + align:start position:0% +the debris from damaging the +pump and possibly even going into the + + align:start position:0% +pump and possibly even going into the + + + align:start position:0% +pump and possibly even going into the +main cool pumps and Main cooling system + + align:start position:0% +main cool pumps and Main cooling system + + + align:start position:0% +main cool pumps and Main cooling system +and actually getting into the reactor + + align:start position:0% +and actually getting into the reactor + + + align:start position:0% +and actually getting into the reactor +vessel so the NRC had a a a big issue + + align:start position:0% +vessel so the NRC had a a a big issue + + + align:start position:0% +vessel so the NRC had a a a big issue +about identifying whether or not these + + align:start position:0% +about identifying whether or not these + + + align:start position:0% +about identifying whether or not these +bwrs debris screens would in fact block + + align:start position:0% +bwrs debris screens would in fact block + + + align:start position:0% +bwrs debris screens would in fact block +sufficient water from getting to the + + align:start position:0% +sufficient water from getting to the + + + align:start position:0% +sufficient water from getting to the +pumps and then not allowing water to be + + align:start position:0% +pumps and then not allowing water to be + + + align:start position:0% +pumps and then not allowing water to be +recirculated and this is this neet + + align:start position:0% +recirculated and this is this neet + + + align:start position:0% +recirculated and this is this neet +positive suction head and that was can + + align:start position:0% +positive suction head and that was can + + + align:start position:0% +positive suction head and that was can +you get enough water pumping through the + + align:start position:0% +you get enough water pumping through the + + + align:start position:0% +you get enough water pumping through the +pumps to be able to um get it to the + + align:start position:0% +pumps to be able to um get it to the + + + align:start position:0% +pumps to be able to um get it to the +appropriate places whether it be the + + align:start position:0% +appropriate places whether it be the + + + align:start position:0% +appropriate places whether it be the +reactor vessel or um or the sprays and + + align:start position:0% +reactor vessel or um or the sprays and + + + align:start position:0% +reactor vessel or um or the sprays and +it's it's basically the causing + + align:start position:0% +it's it's basically the causing + + + align:start position:0% +it's it's basically the causing +potentially a failure of the resarch + + align:start position:0% +potentially a failure of the resarch + + + align:start position:0% +potentially a failure of the resarch +pump or cavitation of these pumps both + + align:start position:0% +pump or cavitation of these pumps both + + + align:start position:0% +pump or cavitation of these pumps both +are not good things so initially as you + + align:start position:0% +are not good things so initially as you + + + align:start position:0% +are not good things so initially as you +look at it it's it's it's ass it was + + align:start position:0% +look at it it's it's it's ass it was + + + align:start position:0% +look at it it's it's it's ass it was +associated with insufficient cooling + + align:start position:0% +associated with insufficient cooling + + + align:start position:0% +associated with insufficient cooling +then in the early + + align:start position:0% +then in the early + + + align:start position:0% +then in the early +1990s um well there's a there's a red + + align:start position:0% +1990s um well there's a there's a red + + + align:start position:0% +1990s um well there's a there's a red +guide let me just write down the red + + align:start position:0% +guide let me just write down the red + + + align:start position:0% +guide let me just write down the red +guide so you can kind of + + align:start position:0% + + + + align:start position:0% + +here there's a red guy that was + + align:start position:0% +here there's a red guy that was + + + align:start position:0% +here there's a red guy that was +issued it was on the sum + + align:start position:0% + + + + align:start position:0% + +question it was red + + align:start position:0% +question it was red + + + align:start position:0% +question it was red +guy + + align:start position:0% +guy + + + align:start position:0% +guy +1.82 and it was largely in response to + + align:start position:0% + + + + align:start position:0% + +bwrs and they had a generic letter as + + align:start position:0% +bwrs and they had a generic letter as + + + align:start position:0% +bwrs and they had a generic letter as +well which was 85 + + align:start position:0% +well which was 85 + + + align:start position:0% +well which was 85 +-22 so you can see how long ago this + + align:start position:0% +-22 so you can see how long ago this + + + align:start position:0% +-22 so you can see how long ago this +issue + + align:start position:0% +issue + + + align:start position:0% +issue +started + + align:start position:0% +started + + + align:start position:0% +started +and 1979 was the first time they got + + align:start position:0% +and 1979 was the first time they got + + + align:start position:0% +and 1979 was the first time they got +this thing gone under bre + + align:start position:0% +this thing gone under bre + + + align:start position:0% +this thing gone under bre +blockage uh they did some research they + + align:start position:0% +blockage uh they did some research they + + + align:start position:0% +blockage uh they did some research they +did some preliminary analysis and they + + align:start position:0% +did some preliminary analysis and they + + + align:start position:0% +did some preliminary analysis and they +basically had to bwr people fix certain + + align:start position:0% +basically had to bwr people fix certain + + + align:start position:0% +basically had to bwr people fix certain +things but they they concluded that it + + align:start position:0% +things but they they concluded that it + + + align:start position:0% +things but they they concluded that it +was kind of okay for + + align:start position:0% + + + + align:start position:0% + +PW back at that + + align:start position:0% +PW back at that + + + align:start position:0% +PW back at that +time then they started looking at that + + align:start position:0% +time then they started looking at that + + + align:start position:0% +time then they started looking at that +and now now we're talking into the late + + align:start position:0% + + + + align:start position:0% + +1990s and they said well gee maybe pwrs + + align:start position:0% +1990s and they said well gee maybe pwrs + + + align:start position:0% +1990s and they said well gee maybe pwrs +are also susceptible to this + + align:start position:0% +are also susceptible to this + + + align:start position:0% +are also susceptible to this +problem and the the issue was very + + align:start position:0% +problem and the the issue was very + + + align:start position:0% +problem and the the issue was very +similar but they had uh the screens that + + align:start position:0% +similar but they had uh the screens that + + + align:start position:0% +similar but they had uh the screens that +they had were somewhat different in + + align:start position:0% +they had were somewhat different in + + + align:start position:0% +they had were somewhat different in +design than the BW was + + align:start position:0% + + + + align:start position:0% + +and they felt that initially the PWS + + align:start position:0% +and they felt that initially the PWS + + + align:start position:0% +and they felt that initially the PWS +screens were fine but then they had some + + align:start position:0% +screens were fine but then they had some + + + align:start position:0% +screens were fine but then they had some +experiments and they had some events + + align:start position:0% +experiments and they had some events + + + align:start position:0% +experiments and they had some events +that occurred that suggested that well + + align:start position:0% +that occurred that suggested that well + + + align:start position:0% +that occurred that suggested that well +we have a similar problem here and um + + align:start position:0% +we have a similar problem here and um + + + align:start position:0% +we have a similar problem here and um +they then began looking at it for PW now + + align:start position:0% +they then began looking at it for PW now + + + align:start position:0% +they then began looking at it for PW now +this is a current + + align:start position:0% +this is a current + + + align:start position:0% +this is a current +issue and they've done evaluations the + + align:start position:0% +issue and they've done evaluations the + + + align:start position:0% +issue and they've done evaluations the +NC has done + + align:start position:0% +NC has done + + + align:start position:0% +NC has done +evaluations and as has the + + align:start position:0% +evaluations and as has the + + + align:start position:0% +evaluations and as has the +industry and what they concluded was + + align:start position:0% +industry and what they concluded was + + + align:start position:0% +industry and what they concluded was +that some of this debris could pass + + align:start position:0% +that some of this debris could pass + + + align:start position:0% +that some of this debris could pass +through the + + align:start position:0% +through the + + + align:start position:0% +through the +screen and could get into the + + align:start position:0% +screen and could get into the + + + align:start position:0% +screen and could get into the +core and the issue basically is if it + + align:start position:0% +core and the issue basically is if it + + + align:start position:0% +core and the issue basically is if it +goes into the + + align:start position:0% +goes into the + + + align:start position:0% +goes into the +core it could obviously block some fuel + + align:start position:0% +core it could obviously block some fuel + + + align:start position:0% +core it could obviously block some fuel +pin Fuel + + align:start position:0% + + + + align:start position:0% + +assends and the industry responded by by + + align:start position:0% +assends and the industry responded by by + + + align:start position:0% +assends and the industry responded by by +doing some analysis saying that yes if + + align:start position:0% +doing some analysis saying that yes if + + + align:start position:0% +doing some analysis saying that yes if +it blocks some fuel assemblies there are + + align:start position:0% +it blocks some fuel assemblies there are + + + align:start position:0% +it blocks some fuel assemblies there are +efficient number of + + align:start position:0% +efficient number of + + + align:start position:0% +efficient number of +holes in the core Barrel or areas where + + align:start position:0% +holes in the core Barrel or areas where + + + align:start position:0% +holes in the core Barrel or areas where +water can in fact come into the core + + align:start position:0% +water can in fact come into the core + + + align:start position:0% +water can in fact come into the core +that it is not a soal imminent + + align:start position:0% +that it is not a soal imminent + + + align:start position:0% +that it is not a soal imminent +problem which meant that they would be + + align:start position:0% +problem which meant that they would be + + + align:start position:0% +problem which meant that they would be +allowed to continue to + + align:start position:0% + + + + align:start position:0% + +operate until this issue was technically + + align:start position:0% +operate until this issue was technically + + + align:start position:0% +operate until this issue was technically +resolved and the issue resolution was + + align:start position:0% +resolved and the issue resolution was + + + align:start position:0% +resolved and the issue resolution was +size of the screen + + align:start position:0% +size of the screen + + + align:start position:0% +size of the screen +mesh + + align:start position:0% +mesh + + + align:start position:0% +mesh +and the impact on the + + align:start position:0% + + + + align:start position:0% + +core so we're fighting two things if you + + align:start position:0% +core so we're fighting two things if you + + + align:start position:0% +core so we're fighting two things if you +make it too fine a + + align:start position:0% +make it too fine a + + + align:start position:0% +make it too fine a +screen you're not going to get water to + + align:start position:0% +screen you're not going to get water to + + + align:start position:0% +screen you're not going to get water to +the pump if you make it too loose a + + align:start position:0% +the pump if you make it too loose a + + + align:start position:0% +the pump if you make it too loose a +screen you'll get debris into the + + align:start position:0% +screen you'll get debris into the + + + align:start position:0% +screen you'll get debris into the +core both are not good but there this is + + align:start position:0% +core both are not good but there this is + + + align:start position:0% +core both are not good but there this is +this is still a very active safety issue + + align:start position:0% +this is still a very active safety issue + + + align:start position:0% +this is still a very active safety issue +and + + align:start position:0% +and + + + align:start position:0% +and +um the last bulletin I guess was + + align:start position:0% +um the last bulletin I guess was + + + align:start position:0% +um the last bulletin I guess was +bulletin on this one + + align:start position:0% + + + + align:start position:0% + + + align:start position:0% + + + align:start position:0% +2003-1 and it still requires lenses to + + align:start position:0% +2003-1 and it still requires lenses to + + + align:start position:0% +2003-1 and it still requires lenses to +demonstrate that they that this will not + + align:start position:0% +demonstrate that they that this will not + + + align:start position:0% +demonstrate that they that this will not +be a problem for + + align:start position:0% + + + + align:start position:0% + +them okay now you remember the + + align:start position:0% +them okay now you remember the + + + align:start position:0% +them okay now you remember the +differences I I've written down a couple + + align:start position:0% +differences I I've written down a couple + + + align:start position:0% +differences I I've written down a couple +of things I've written down regulatory + + align:start position:0% +of things I've written down regulatory + + + align:start position:0% +of things I've written down regulatory +guides I've written down bulletins and + + align:start position:0% +guides I've written down bulletins and + + + align:start position:0% +guides I've written down bulletins and +I've written down generic letters do you + + align:start position:0% +I've written down generic letters do you + + + align:start position:0% +I've written down generic letters do you +recall the + + align:start position:0% +recall the + + + align:start position:0% +recall the +differences + + align:start position:0% +differences + + + align:start position:0% +differences +so the bulle have respond exactly the + + align:start position:0% +so the bulle have respond exactly the + + + align:start position:0% +so the bulle have respond exactly the +bulletins have to be responded to + + align:start position:0% +bulletins have to be responded to + + + align:start position:0% +bulletins have to be responded to +generic letters are heads up may may + + align:start position:0% +generic letters are heads up may may + + + align:start position:0% +generic letters are heads up may may +request some information red guides are + + align:start position:0% +request some information red guides are + + + align:start position:0% +request some information red guides are +this is a way to + + align:start position:0% +this is a way to + + + align:start position:0% +this is a way to +comply to this question so you've got + + align:start position:0% +comply to this question so you've got + + + align:start position:0% +comply to this question so you've got +all kinds of different approaches that + + align:start position:0% +all kinds of different approaches that + + + align:start position:0% +all kinds of different approaches that +the NRC has taken to allow the industry + + align:start position:0% +the NRC has taken to allow the industry + + + align:start position:0% +the NRC has taken to allow the industry +to be aware of a problem and how best to + + align:start position:0% +to be aware of a problem and how best to + + + align:start position:0% +to be aware of a problem and how best to +to get the solution of this problem and + + align:start position:0% +to get the solution of this problem and + + + align:start position:0% +to get the solution of this problem and +if you go if you go on the NRC website + + align:start position:0% +if you go if you go on the NRC website + + + align:start position:0% +if you go if you go on the NRC website +you'll see a lot of Industry + + align:start position:0% +you'll see a lot of Industry + + + align:start position:0% +you'll see a lot of Industry +presentations if you go under + + align:start position:0% + + + + align:start position:0% + +meetings you'll see sometimes anyi + + align:start position:0% +meetings you'll see sometimes anyi + + + align:start position:0% +meetings you'll see sometimes anyi +presentation and they'll see and you'll + + align:start position:0% +presentation and they'll see and you'll + + + align:start position:0% +presentation and they'll see and you'll +get from that website + + align:start position:0% +get from that website + + + align:start position:0% +get from that website +slides of what people have said from the + + align:start position:0% +slides of what people have said from the + + + align:start position:0% +slides of what people have said from the +industry's perspective now this one is + + align:start position:0% +industry's perspective now this one is + + + align:start position:0% +industry's perspective now this one is +in long-term core long-term core pooling + + align:start position:0% +in long-term core long-term core pooling + + + align:start position:0% +in long-term core long-term core pooling +on core Inlet flow blockage which + + align:start position:0% +on core Inlet flow blockage which + + + align:start position:0% +on core Inlet flow blockage which +basically said + + align:start position:0% +basically said + + + align:start position:0% +basically said +well we've got a lot of this debris + + align:start position:0% +well we've got a lot of this debris + + + align:start position:0% +well we've got a lot of this debris +coming through and it's going to impact + + align:start position:0% +coming through and it's going to impact + + + align:start position:0% +coming through and it's going to impact +the core and this is our analysis + + align:start position:0% +the core and this is our analysis + + + align:start position:0% +the core and this is our analysis +showing that we do not believe we have a + + align:start position:0% +showing that we do not believe we have a + + + align:start position:0% +showing that we do not believe we have a +problem under various + + align:start position:0% +problem under various + + + align:start position:0% +problem under various +scenarios could you open a + + align:start position:0% +scenarios could you open a + + + align:start position:0% +scenarios could you open a +window I'm warm as can + + align:start position:0% +window I'm warm as can + + + align:start position:0% +window I'm warm as can +be okay the the next issue is reactor + + align:start position:0% +be okay the the next issue is reactor + + + align:start position:0% +be okay the the next issue is reactor +cooling system weld issues now this + + align:start position:0% +cooling system weld issues now this + + + align:start position:0% +cooling system weld issues now this +graphic again comes from their + + align:start position:0% +graphic again comes from their + + + align:start position:0% +graphic again comes from their +website now these are all the are + + align:start position:0% +website now these are all the are + + + align:start position:0% +website now these are all the are +in which there are weld issue problems + + align:start position:0% +in which there are weld issue problems + + + align:start position:0% +in which there are weld issue problems +now you're looking at this like oh my + + align:start position:0% +now you're looking at this like oh my + + + align:start position:0% +now you're looking at this like oh my +goodness this is a this is this is not + + align:start position:0% +goodness this is a this is this is not + + + align:start position:0% +goodness this is a this is this is not +these things are kind of wearing out + + align:start position:0% +these things are kind of wearing out + + + align:start position:0% +these things are kind of wearing out +aren't they first you had we all know + + align:start position:0% +aren't they first you had we all know + + + align:start position:0% +aren't they first you had we all know +about the upper head control rod Drive + + align:start position:0% +about the upper head control rod Drive + + + align:start position:0% +about the upper head control rod Drive +um issues relative to Davis Bessie and + + align:start position:0% +um issues relative to Davis Bessie and + + + align:start position:0% +um issues relative to Davis Bessie and +other + + align:start position:0% +other + + + align:start position:0% +other +plants we vaguely or briefly mentioned + + align:start position:0% +plants we vaguely or briefly mentioned + + + align:start position:0% +plants we vaguely or briefly mentioned +pressurizer + + align:start position:0% +pressurizer + + + align:start position:0% +pressurizer +leaks Wells coming into or out of the um + + align:start position:0% +leaks Wells coming into or out of the um + + + align:start position:0% +leaks Wells coming into or out of the um +the reactor vessel and around the + + align:start position:0% +the reactor vessel and around the + + + align:start position:0% +the reactor vessel and around the +pressurizer around the main coolant + + align:start position:0% +pressurizer around the main coolant + + + align:start position:0% +pressurizer around the main coolant +pumps the lower reactor vessel head + + align:start position:0% +pumps the lower reactor vessel head + + + align:start position:0% +pumps the lower reactor vessel head +where in current plants all the + + align:start position:0% +where in current plants all the + + + align:start position:0% +where in current plants all the +instrumentation penetrations come + + align:start position:0% +instrumentation penetrations come + + + align:start position:0% +instrumentation penetrations come +through the bottom + + align:start position:0% +through the bottom + + + align:start position:0% +through the bottom +head and these areas are now becoming + + align:start position:0% +head and these areas are now becoming + + + align:start position:0% +head and these areas are now becoming +also very very important and they have a + + align:start position:0% +also very very important and they have a + + + align:start position:0% +also very very important and they have a +common common root + + align:start position:0% +common common root + + + align:start position:0% +common common root +cause and these the root cause is a + + align:start position:0% +cause and these the root cause is a + + + align:start position:0% +cause and these the root cause is a +certain type of alloy that's used in the + + align:start position:0% +certain type of alloy that's used in the + + + align:start position:0% +certain type of alloy that's used in the +wells and the butter in other words + + align:start position:0% +wells and the butter in other words + + + align:start position:0% +wells and the butter in other words +which is the uh materials that are uh + + align:start position:0% +which is the uh materials that are uh + + + align:start position:0% +which is the uh materials that are uh +associated with this alloy + + align:start position:0% +associated with this alloy + + + align:start position:0% +associated with this alloy +600 and it's it's primarily a primary + + align:start position:0% +600 and it's it's primarily a primary + + + align:start position:0% +600 and it's it's primarily a primary +stress water stress corrosion cracking + + align:start position:0% +stress water stress corrosion cracking + + + align:start position:0% +stress water stress corrosion cracking +which we talked about it's very clean + + align:start position:0% +which we talked about it's very clean + + + align:start position:0% +which we talked about it's very clean +water and the the determinant are + + align:start position:0% +water and the the determinant are + + + align:start position:0% +water and the the determinant are +temperature what the residual stresses + + align:start position:0% +temperature what the residual stresses + + + align:start position:0% +temperature what the residual stresses +are at those locations and how much of + + align:start position:0% +are at those locations and how much of + + + align:start position:0% +are at those locations and how much of +this nickel based Alo and how it was + + align:start position:0% +this nickel based Alo and how it was + + + align:start position:0% +this nickel based Alo and how it was +applied to these various Wells now I've + + align:start position:0% +applied to these various Wells now I've + + + align:start position:0% +applied to these various Wells now I've +just listed a few plants that have been + + align:start position:0% +just listed a few plants that have been + + + align:start position:0% +just listed a few plants that have been +affected now once you detect this + + align:start position:0% +affected now once you detect this + + + align:start position:0% +affected now once you detect this +problem there's a solution well first + + align:start position:0% +problem there's a solution well first + + + align:start position:0% +problem there's a solution well first +you got to detect which is a lot of + + align:start position:0% +you got to detect which is a lot of + + + align:start position:0% +you got to detect which is a lot of +measuring devices and you can imagine if + + align:start position:0% +measuring devices and you can imagine if + + + align:start position:0% +measuring devices and you can imagine if +you're in these areas it's probably a + + align:start position:0% +you're in these areas it's probably a + + + align:start position:0% +you're in these areas it's probably a +fair relatively High radiation zone so + + align:start position:0% +fair relatively High radiation zone so + + + align:start position:0% +fair relatively High radiation zone so +these are not easy to do but if you find + + align:start position:0% +these are not easy to do but if you find + + + align:start position:0% +these are not easy to do but if you find +these flaws you then the solution is + + align:start position:0% +these flaws you then the solution is + + + align:start position:0% +these flaws you then the solution is +grind it out and weld overlay take + + align:start position:0% +grind it out and weld overlay take + + + align:start position:0% +grind it out and weld overlay take +different weld metal and weld overlay so + + align:start position:0% +different weld metal and weld overlay so + + + align:start position:0% +different weld metal and weld overlay so +that you can avoid the leak that may + + align:start position:0% +that you can avoid the leak that may + + + align:start position:0% +that you can avoid the leak that may +occur + + align:start position:0% +occur + + + align:start position:0% +occur +now we also have in this case we have a + + align:start position:0% +now we also have in this case we have a + + + align:start position:0% +now we also have in this case we have a +different different type of + + align:start position:0% +different different type of + + + align:start position:0% +different different type of +response now the this + + align:start position:0% +response now the this + + + align:start position:0% +response now the this +alloy alloy 600 and 182 and and and + + align:start position:0% +alloy alloy 600 and 182 and and and + + + align:start position:0% +alloy alloy 600 and 182 and and and +82 are are basically the the the + + align:start position:0% +82 are are basically the the the + + + align:start position:0% +82 are are basically the the the +Structural Materials that keeps these + + align:start position:0% +Structural Materials that keeps these + + + align:start position:0% +Structural Materials that keeps these +pipes + + align:start position:0% +pipes + + + align:start position:0% +pipes +together and just just to get some + + align:start position:0% +together and just just to get some + + + align:start position:0% +together and just just to get some +perspective again on on timing and I + + align:start position:0% +perspective again on on timing and I + + + align:start position:0% +perspective again on on timing and I +think you're you're going to see a theme + + align:start position:0% +think you're you're going to see a theme + + + align:start position:0% +think you're you're going to see a theme +emerge from this discussion on the + + align:start position:0% +emerge from this discussion on the + + + align:start position:0% +emerge from this discussion on the +timing + + align:start position:0% + + + + align:start position:0% + +question this was first + + align:start position:0% +question this was first + + + align:start position:0% +question this was first +detected in + + align:start position:0% +detected in + + + align:start position:0% +detected in +1989 at calber + + align:start position:0% +1989 at calber + + + align:start position:0% +1989 at calber +cliffs in um in + + align:start position:0% + + + + align:start position:0% + +Mar and the issue here was a pressurizer + + align:start position:0% + + + + align:start position:0% + +It's usually the hottest component and + + align:start position:0% +It's usually the hottest component and + + + align:start position:0% +It's usually the hottest component and +and during the fabrication it probably + + align:start position:0% +and during the fabrication it probably + + + align:start position:0% +and during the fabrication it probably +had a lot of stresses and it's on the + + align:start position:0% +had a lot of stresses and it's on the + + + align:start position:0% +had a lot of stresses and it's on the +heater + + align:start position:0% + + + + align:start position:0% + +sleeves which would the pressurizer + + align:start position:0% +sleeves which would the pressurizer + + + align:start position:0% +sleeves which would the pressurizer +heaters you know they get pretty hot and + + align:start position:0% +heaters you know they get pretty hot and + + + align:start position:0% +heaters you know they get pretty hot and +toasty and that's where the the the + + align:start position:0% +toasty and that's where the the the + + + align:start position:0% +toasty and that's where the the the +welds begin to start + + align:start position:0% +welds begin to start + + + align:start position:0% +welds begin to start +leaking and that resulted in information + + align:start position:0% +leaking and that resulted in information + + + align:start position:0% +leaking and that resulted in information +notice 90 D + + align:start position:0% + + + + align:start position:0% + +10 then we saw I think you remember that + + align:start position:0% +10 then we saw I think you remember that + + + align:start position:0% +10 then we saw I think you remember that +chart timeline chart we had this thing + + align:start position:0% +chart timeline chart we had this thing + + + align:start position:0% +chart timeline chart we had this thing +at the bougie plant in + + align:start position:0% + + + + align:start position:0% + +France and that occurred roughly in + + align:start position:0% + + + + align:start position:0% + +1991 and you recall the industry + + align:start position:0% +1991 and you recall the industry + + + align:start position:0% +1991 and you recall the industry +response to that event was different + + align:start position:0% +response to that event was different + + + align:start position:0% +response to that event was different +type of problem we don't have this + + align:start position:0% +type of problem we don't have this + + + align:start position:0% +type of problem we don't have this +design here our vessel's heads are made + + align:start position:0% +design here our vessel's heads are made + + + align:start position:0% +design here our vessel's heads are made +different differently and the NRC pretty + + align:start position:0% +different differently and the NRC pretty + + + align:start position:0% +different differently and the NRC pretty +much bought that argument based on Nei + + align:start position:0% +much bought that argument based on Nei + + + align:start position:0% +much bought that argument based on Nei +and every + + align:start position:0% +and every + + + align:start position:0% +and every +analysis and that bought some time but + + align:start position:0% +analysis and that bought some time but + + + align:start position:0% +analysis and that bought some time but +not a lot of + + align:start position:0% +not a lot of + + + align:start position:0% +not a lot of +time it then became interesting once + + align:start position:0% +time it then became interesting once + + + align:start position:0% +time it then became interesting once +again when people started looking + + align:start position:0% +again when people started looking + + + align:start position:0% +again when people started looking +at various inspections NRC Mand mandated + + align:start position:0% +at various inspections NRC Mand mandated + + + align:start position:0% +at various inspections NRC Mand mandated +some inspections + + align:start position:0% +some inspections + + + align:start position:0% +some inspections +of all of these types of welds as they + + align:start position:0% +of all of these types of welds as they + + + align:start position:0% +of all of these types of welds as they +in fact + + align:start position:0% +in fact + + + align:start position:0% +in fact +occurred and the sequence was well back + + align:start position:0% +occurred and the sequence was well back + + + align:start position:0% +occurred and the sequence was well back +in in + + align:start position:0% +in in + + + align:start position:0% +in in +1993 the conclusion was that the um + + align:start position:0% +1993 the conclusion was that the um + + + align:start position:0% +1993 the conclusion was that the um +these cracks were axial remember the + + align:start position:0% +these cracks were axial remember the + + + align:start position:0% +these cracks were axial remember the +axial + + align:start position:0% +axial + + + align:start position:0% +axial +discussion that they would result in + + align:start position:0% +discussion that they would result in + + + align:start position:0% +discussion that they would result in +detectable + + align:start position:0% + + + + align:start position:0% + +leakage detectable leakage + + align:start position:0% + + + + align:start position:0% + +and um you could be seen + + align:start position:0% + + + + align:start position:0% + +visually So based on their + + align:start position:0% +visually So based on their + + + align:start position:0% +visually So based on their +analysis and this was their basis that + + align:start position:0% +analysis and this was their basis that + + + align:start position:0% +analysis and this was their basis that +said oh it's okay it's not a problem for + + align:start position:0% +said oh it's okay it's not a problem for + + + align:start position:0% +said oh it's okay it's not a problem for +us CS if it's going to leak it's going + + align:start position:0% +us CS if it's going to leak it's going + + + align:start position:0% +us CS if it's going to leak it's going +to be axial it's not going to be + + align:start position:0% +to be axial it's not going to be + + + align:start position:0% +to be axial it's not going to be +circumferential which means the whole + + align:start position:0% +circumferential which means the whole + + + align:start position:0% +circumferential which means the whole +thing is apart and we can see it in + + align:start position:0% +thing is apart and we can see it in + + + align:start position:0% +thing is apart and we can see it in +terms of the detectable leakage because + + align:start position:0% +terms of the detectable leakage because + + + align:start position:0% +terms of the detectable leakage because +we don't and we can we can see it easily + + align:start position:0% +we don't and we can we can see it easily + + + align:start position:0% +we don't and we can we can see it easily +by simply taking a visual + + align:start position:0% +by simply taking a visual + + + align:start position:0% +by simply taking a visual +examination however when they started + + align:start position:0% +examination however when they started + + + align:start position:0% +examination however when they started +doing some of these inspections in + + align:start position:0% +doing some of these inspections in + + + align:start position:0% +doing some of these inspections in +1994 they found at Point + + align:start position:0% + + + + align:start position:0% + +Beach + + align:start position:0% +Beach + + + align:start position:0% +Beach +that of the of the control rods the + + align:start position:0% +that of the of the control rods the + + + align:start position:0% +that of the of the control rods the +crdm they had lots of indications I + + align:start position:0% +crdm they had lots of indications I + + + align:start position:0% +crdm they had lots of indications I +think that I think that was 49 + + align:start position:0% + + + + align:start position:0% + +indications and that sort of got got + + align:start position:0% +indications and that sort of got got + + + align:start position:0% +indications and that sort of got got +them going and they used what they + + align:start position:0% +them going and they used what they + + + align:start position:0% +them going and they used what they +called Ed current + + align:start position:0% + + + + align:start position:0% + +testing so it was not visual it was more + + align:start position:0% +testing so it was not visual it was more + + + align:start position:0% +testing so it was not visual it was more +scientific where they were looking for + + align:start position:0% +scientific where they were looking for + + + align:start position:0% +scientific where they were looking for +fors and in the process they also + + align:start position:0% +fors and in the process they also + + + align:start position:0% +fors and in the process they also +started looking at okone and you + + align:start position:0% +started looking at okone and you + + + align:start position:0% +started looking at okone and you +remember the okone okone unit one I + + align:start position:0% +remember the okone okone unit one I + + + align:start position:0% +remember the okone okone unit one I +think it was was it Aon + + align:start position:0% +think it was was it Aon + + + align:start position:0% +think it was was it Aon +one Aon one in 1994 + + align:start position:0% +one Aon one in 1994 + + + align:start position:0% +one Aon one in 1994 +they also found 20 + + align:start position:0% + + + + align:start position:0% + +indications and the sequence goes on and + + align:start position:0% +indications and the sequence goes on and + + + align:start position:0% +indications and the sequence goes on and +on and on until the NRC finally decided + + align:start position:0% +on and on until the NRC finally decided + + + align:start position:0% +on and on until the NRC finally decided +with a lot of + + align:start position:0% + + + + align:start position:0% + +these findings that this stuff was fail + + align:start position:0% +these findings that this stuff was fail + + + align:start position:0% +these findings that this stuff was fail +and they give you they gave you generic + + align:start position:0% +and they give you they gave you generic + + + align:start position:0% +and they give you they gave you generic +letter + + align:start position:0% + + + + align:start position:0% + +9701 which attempted to do a + + align:start position:0% +9701 which attempted to do a + + + align:start position:0% +9701 which attempted to do a +probabilistic + + align:start position:0% + + + + align:start position:0% + +analysis of the + + align:start position:0% +analysis of the + + + align:start position:0% +analysis of the +likelihood and of these cracks occurring + + align:start position:0% +likelihood and of these cracks occurring + + + align:start position:0% +likelihood and of these cracks occurring +and potential damage in terms of + + align:start position:0% + + + + align:start position:0% + +growth what what what do you sense + + align:start position:0% +growth what what what do you sense + + + align:start position:0% +growth what what what do you sense +that's going on here growth what do you + + align:start position:0% +that's going on here growth what do you + + + align:start position:0% +that's going on here growth what do you +sense that's going on the NRC is trying + + align:start position:0% +sense that's going on the NRC is trying + + + align:start position:0% +sense that's going on the NRC is trying +to understand this + + align:start position:0% +to understand this + + + align:start position:0% +to understand this +problem they know it + + align:start position:0% +problem they know it + + + align:start position:0% +problem they know it +exists they're not prepared to shut down + + align:start position:0% +exists they're not prepared to shut down + + + align:start position:0% +exists they're not prepared to shut down +every plant to do visual inspections + + align:start position:0% +every plant to do visual inspections + + + align:start position:0% +every plant to do visual inspections +but they're saying to to the utilities + + align:start position:0% +but they're saying to to the utilities + + + align:start position:0% +but they're saying to to the utilities +you must give us a better case to + + align:start position:0% +you must give us a better case to + + + align:start position:0% +you must give us a better case to +justify why you should be operating and + + align:start position:0% +justify why you should be operating and + + + align:start position:0% +justify why you should be operating and +in order to do that we need to + + align:start position:0% +in order to do that we need to + + + align:start position:0% +in order to do that we need to +understand why these things are failing + + align:start position:0% +understand why these things are failing + + + align:start position:0% +understand why these things are failing +what is the history of this of this uh + + align:start position:0% +what is the history of this of this uh + + + align:start position:0% +what is the history of this of this uh +fabrication how was this stuff stress + + align:start position:0% +fabrication how was this stuff stress + + + align:start position:0% +fabrication how was this stuff stress +relieved was it + + align:start position:0% +relieved was it + + + align:start position:0% +relieved was it +um you know when they fabricated this + + align:start position:0% +um you know when they fabricated this + + + align:start position:0% +um you know when they fabricated this +particular nozzle this particular piece + + align:start position:0% +particular nozzle this particular piece + + + align:start position:0% +particular nozzle this particular piece +was it highly stressed when they + + align:start position:0% +was it highly stressed when they + + + align:start position:0% +was it highly stressed when they +assembled it and based on that + + align:start position:0% +assembled it and based on that + + + align:start position:0% +assembled it and based on that +information they were able to say the + + align:start position:0% +information they were able to say the + + + align:start position:0% +information they were able to say the +utility able to say we don't think these + + align:start position:0% + + + + align:start position:0% + +susceptible + + align:start position:0% +susceptible + + + align:start position:0% +susceptible +to to + + align:start position:0% +to to + + + align:start position:0% +to to +cracks or there was a function of + + align:start position:0% +cracks or there was a function of + + + align:start position:0% +cracks or there was a function of +time that people were able to say well + + align:start position:0% +time that people were able to say well + + + align:start position:0% +time that people were able to say well +we're not we don't expect to see this + + align:start position:0% +we're not we don't expect to see this + + + align:start position:0% +we're not we don't expect to see this +for another 5 years based on the + + align:start position:0% +for another 5 years based on the + + + align:start position:0% +for another 5 years based on the +environmental condition that that these + + align:start position:0% +environmental condition that that these + + + align:start position:0% +environmental condition that that these +um that these uh Wells had to + + align:start position:0% +um that these uh Wells had to + + + align:start position:0% +um that these uh Wells had to +experience but the evidence was fairly + + align:start position:0% +experience but the evidence was fairly + + + align:start position:0% +experience but the evidence was fairly +well uh mounting was mounting quite a + + align:start position:0% +well uh mounting was mounting quite a + + + align:start position:0% +well uh mounting was mounting quite a +bit but said there's a real problem and + + align:start position:0% +bit but said there's a real problem and + + + align:start position:0% +bit but said there's a real problem and +as you remember in France what they said + + align:start position:0% +as you remember in France what they said + + + align:start position:0% +as you remember in France what they said +was this is way too expensive to do all + + align:start position:0% +was this is way too expensive to do all + + + align:start position:0% +was this is way too expensive to do all +these visuals we're going to replace all + + align:start position:0% +these visuals we're going to replace all + + + align:start position:0% +these visuals we're going to replace all +the heads and stop the + + align:start position:0% +the heads and stop the + + + align:start position:0% +the heads and stop the +problem that stopped this problem but it + + align:start position:0% +problem that stopped this problem but it + + + align:start position:0% +problem that stopped this problem but it +didn't address necessarily any of these + + align:start position:0% +didn't address necessarily any of these + + + align:start position:0% +didn't address necessarily any of these +others so after they they they began to + + align:start position:0% +others so after they they they began to + + + align:start position:0% +others so after they they they began to +see more and more of these things out + + align:start position:0% +see more and more of these things out + + + align:start position:0% +see more and more of these things out +came bulletin + + align:start position:0% + + + + align:start position:0% + +2001-01 and that basically said all + + align:start position:0% +2001-01 and that basically said all + + + align:start position:0% +2001-01 and that basically said all +right we're done with this looking we've + + align:start position:0% +right we're done with this looking we've + + + align:start position:0% +right we're done with this looking we've +seen evidence that of County one County + + align:start position:0% +seen evidence that of County one County + + + align:start position:0% +seen evidence that of County one County +3 Arkansas unit number one they actually + + align:start position:0% +3 Arkansas unit number one they actually + + + align:start position:0% +3 Arkansas unit number one they actually +saw Boron deposits at some of these + + align:start position:0% +saw Boron deposits at some of these + + + align:start position:0% +saw Boron deposits at some of these +plants remember that and said okay now + + align:start position:0% +plants remember that and said okay now + + + align:start position:0% +plants remember that and said okay now +we're going to have to do something very + + align:start position:0% +we're going to have to do something very + + + align:start position:0% +we're going to have to do something very +serious and in fact this is the first + + align:start position:0% +serious and in fact this is the first + + + align:start position:0% +serious and in fact this is the first +time that we've + + align:start position:0% +time that we've + + + align:start position:0% +time that we've +seen circumferential + + align:start position:0% + + + + align:start position:0% + +ceds and this gave a lot of people a lot + + align:start position:0% +ceds and this gave a lot of people a lot + + + align:start position:0% +ceds and this gave a lot of people a lot +of + + align:start position:0% +of + + + align:start position:0% +of +Paws because for the first time they + + align:start position:0% +Paws because for the first time they + + + align:start position:0% +Paws because for the first time they +were basically saying that these things + + align:start position:0% +were basically saying that these things + + + align:start position:0% +were basically saying that these things +could come apart quite more quite more + + align:start position:0% +could come apart quite more quite more + + + align:start position:0% +could come apart quite more quite more +dramatically than what we assume back in + + align:start position:0% +dramatically than what we assume back in + + + align:start position:0% +dramatically than what we assume back in +uh 1993 + + align:start position:0% +uh 1993 + + + align:start position:0% +uh 1993 + + align:start position:0% + + + align:start position:0% +well after they did some more of these + + align:start position:0% +well after they did some more of these + + + align:start position:0% +well after they did some more of these +inspections up they came with bulletin + + align:start position:0% +inspections up they came with bulletin + + + align:start position:0% +inspections up they came with bulletin +number + + align:start position:0% +number + + + align:start position:0% +number + + align:start position:0% + + + align:start position:0% +-01 and that kind of gave us the Davis + + align:start position:0% +-01 and that kind of gave us the Davis + + + align:start position:0% +-01 and that kind of gave us the Davis +Bessie + + align:start position:0% +Bessie + + + align:start position:0% +Bessie +finding and luckily as we saw there have + + align:start position:0% +finding and luckily as we saw there have + + + align:start position:0% +finding and luckily as we saw there have +been all kinds of um uh no no damage + + align:start position:0% +been all kinds of um uh no no damage + + + align:start position:0% +been all kinds of um uh no no damage +really was resulted from this but it + + align:start position:0% +really was resulted from this but it + + + align:start position:0% +really was resulted from this but it +gave the IND one of the closest near + + align:start position:0% +gave the IND one of the closest near + + + align:start position:0% +gave the IND one of the closest near +misses + + align:start position:0% + + + + align:start position:0% + +ever the + + align:start position:0% + + + + align:start position:0% + +um so you know I don't know how much + + align:start position:0% +um so you know I don't know how much + + + align:start position:0% +um so you know I don't know how much +more to go into this but + + align:start position:0% +more to go into this but + + + align:start position:0% +more to go into this but +they they ultimately required a lot of + + align:start position:0% +they they ultimately required a lot of + + + align:start position:0% +they they ultimately required a lot of +lenses + + align:start position:0% +lenses + + + align:start position:0% +lenses +to um + + align:start position:0% +to um + + + align:start position:0% +to um +identify their highly susceptible + + align:start position:0% +identify their highly susceptible + + + align:start position:0% +identify their highly susceptible +plants and visual and nonvisual + + align:start position:0% +plants and visual and nonvisual + + + align:start position:0% +plants and visual and nonvisual +inspections were mandated to avoid any + + align:start position:0% +inspections were mandated to avoid any + + + align:start position:0% +inspections were mandated to avoid any +of this stuff in the + + align:start position:0% + + + + align:start position:0% + +future and right now people are actually + + align:start position:0% +future and right now people are actually + + + align:start position:0% +future and right now people are actually +doing this the one thing I want to do + + align:start position:0% +doing this the one thing I want to do + + + align:start position:0% +doing this the one thing I want to do +talk about is what they now + + align:start position:0% +talk about is what they now + + + align:start position:0% +talk about is what they now +call I'll keep it on this board it's + + align:start position:0% +call I'll keep it on this board it's + + + align:start position:0% +call I'll keep it on this board it's +BMI bottom mounted + + align:start position:0% +BMI bottom mounted + + + align:start position:0% +BMI bottom mounted +instrumentation and this was found at + + align:start position:0% +instrumentation and this was found at + + + align:start position:0% +instrumentation and this was found at +the South Texas + + align:start position:0% +the South Texas + + + align:start position:0% +the South Texas +Project + + align:start position:0% +Project + + + align:start position:0% +Project +and it had this has to do with the same + + align:start position:0% +and it had this has to do with the same + + + align:start position:0% +and it had this has to do with the same +darn alloy 600 now just imagine a bottom + + align:start position:0% +darn alloy 600 now just imagine a bottom + + + align:start position:0% +darn alloy 600 now just imagine a bottom +mounted instrumentation to + + align:start position:0% +mounted instrumentation to + + + align:start position:0% +mounted instrumentation to +leak all + + align:start position:0% +leak all + + + align:start position:0% +leak all +right um it's it's a cold I mean it's a + + align:start position:0% +right um it's it's a cold I mean it's a + + + align:start position:0% +right um it's it's a cold I mean it's a +hot dark + + align:start position:0% +hot dark + + + align:start position:0% +hot dark +place and the core is right here you're + + align:start position:0% +place and the core is right here you're + + + align:start position:0% +place and the core is right here you're +not going in there during operation or + + align:start position:0% +not going in there during operation or + + + align:start position:0% +not going in there during operation or +even after it shut down of course I've + + align:start position:0% +even after it shut down of course I've + + + align:start position:0% +even after it shut down of course I've +be taken out to visually inspect and + + align:start position:0% +be taken out to visually inspect and + + + align:start position:0% +be taken out to visually inspect and +repair so this could be another major + + align:start position:0% +repair so this could be another major + + + align:start position:0% +repair so this could be another major +issues + + align:start position:0% +issues + + + align:start position:0% +issues +but so + + align:start position:0% +but so + + + align:start position:0% +but so +far they don't have they have not yet + + align:start position:0% +far they don't have they have not yet + + + align:start position:0% +far they don't have they have not yet +identified any other plants besides + + align:start position:0% +identified any other plants besides + + + align:start position:0% +identified any other plants besides +South Texas that has this + + align:start position:0% +South Texas that has this + + + align:start position:0% +South Texas that has this +problem that's not to say it's not + + align:start position:0% +problem that's not to say it's not + + + align:start position:0% +problem that's not to say it's not +occurring because there's no reason why + + align:start position:0% +occurring because there's no reason why + + + align:start position:0% +occurring because there's no reason why +it should only occur there and not + + align:start position:0% +it should only occur there and not + + + align:start position:0% +it should only occur there and not +anywhere + + align:start position:0% +anywhere + + + align:start position:0% +anywhere +else we already talked briefly about the + + align:start position:0% +else we already talked briefly about the + + + align:start position:0% +else we already talked briefly about the +pressurizer and some of these plants I I + + align:start position:0% +pressurizer and some of these plants I I + + + align:start position:0% +pressurizer and some of these plants I I +should I should say BMW + + align:start position:0% +should I should say BMW + + + align:start position:0% +should I should say BMW +everybody that manufactures these things + + align:start position:0% +everybody that manufactures these things + + + align:start position:0% +everybody that manufactures these things +do it in a different way and it really + + align:start position:0% +do it in a different way and it really + + + align:start position:0% +do it in a different way and it really +is related to the manufacturing how + + align:start position:0% +is related to the manufacturing how + + + align:start position:0% +is related to the manufacturing how +these components are made how the head + + align:start position:0% +these components are made how the head + + + align:start position:0% +these components are made how the head +is designed that affects stress + + align:start position:0% +is designed that affects stress + + + align:start position:0% +is designed that affects stress +levs so it is vendor unique and that's + + align:start position:0% +levs so it is vendor unique and that's + + + align:start position:0% +levs so it is vendor unique and that's +why some cases westing house isn't + + align:start position:0% +why some cases westing house isn't + + + align:start position:0% +why some cases westing house isn't +susceptible combustion engineering and + + align:start position:0% +susceptible combustion engineering and + + + align:start position:0% +susceptible combustion engineering and +BMW are in all of these different areas + + align:start position:0% +BMW are in all of these different areas + + + align:start position:0% +BMW are in all of these different areas +so you can't just blank it and say uh + + align:start position:0% +so you can't just blank it and say uh + + + align:start position:0% +so you can't just blank it and say uh +it's all PWS have this particular + + align:start position:0% +it's all PWS have this particular + + + align:start position:0% +it's all PWS have this particular +problem + + align:start position:0% + + + + align:start position:0% + +um so I I think what you're going to be + + align:start position:0% +um so I I think what you're going to be + + + align:start position:0% +um so I I think what you're going to be +seeing in the in the near + + align:start position:0% +seeing in the in the near + + + align:start position:0% +seeing in the in the near +term uh is as more of these leaks + + align:start position:0% +term uh is as more of these leaks + + + align:start position:0% +term uh is as more of these leaks +develop this is a + + align:start position:0% +develop this is a + + + align:start position:0% +develop this is a +fix this can be fixed by weld overlays + + align:start position:0% +fix this can be fixed by weld overlays + + + align:start position:0% +fix this can be fixed by weld overlays +and relatively easy to inspect as can + + align:start position:0% +and relatively easy to inspect as can + + + align:start position:0% +and relatively easy to inspect as can +these be you can replace + + align:start position:0% +these be you can replace + + + align:start position:0% +these be you can replace +pressurizes this becomes a little + + align:start position:0% +pressurizes this becomes a little + + + align:start position:0% +pressurizes this becomes a little +trickier because that's there's a lot of + + align:start position:0% +trickier because that's there's a lot of + + + align:start position:0% +trickier because that's there's a lot of +incore instrumentation it's like a a + + align:start position:0% +incore instrumentation it's like a a + + + align:start position:0% +incore instrumentation it's like a a +forest down there heads can be + + align:start position:0% +forest down there heads can be + + + align:start position:0% +forest down there heads can be +replaced but the challenge and the + + align:start position:0% +replaced but the challenge and the + + + align:start position:0% +replaced but the challenge and the +additional cost and expense of doing + + align:start position:0% +additional cost and expense of doing + + + align:start position:0% +additional cost and expense of doing +these inspections is very very great any + + align:start position:0% +these inspections is very very great any + + + align:start position:0% +these inspections is very very great any +questions on on that one + + align:start position:0% + + + + align:start position:0% + +no fire + + align:start position:0% + + + + align:start position:0% + +protection um fire protection has an its + + align:start position:0% +protection um fire protection has an its + + + align:start position:0% +protection um fire protection has an its +own very interesting + + align:start position:0% +own very interesting + + + align:start position:0% +own very interesting +story this over Fire + + align:start position:0% +story this over Fire + + + align:start position:0% +story this over Fire +Protection + + align:start position:0% +Protection + + + align:start position:0% +Protection +um obviously the objective is to prevent + + align:start position:0% +um obviously the objective is to prevent + + + align:start position:0% +um obviously the objective is to prevent +fires now let's let's really go back to + + align:start position:0% + + + + align:start position:0% + +history how many of you remember the + + align:start position:0% +history how many of you remember the + + + align:start position:0% +history how many of you remember the +brown sper + + align:start position:0% +brown sper + + + align:start position:0% +brown sper +fire how many of you have heard of the + + align:start position:0% +fire how many of you have heard of the + + + align:start position:0% +fire how many of you have heard of the +brown Fair + + align:start position:0% +brown Fair + + + align:start position:0% +brown Fair +fire one okay we can start from + + align:start position:0% + + + + align:start position:0% + +there what is anybody remember what + + align:start position:0% +there what is anybody remember what + + + align:start position:0% +there what is anybody remember what +plant they just + + align:start position:0% + + + + align:start position:0% + +restarted + + align:start position:0% +restarted + + + align:start position:0% +restarted +after about 10 15 years of being shut + + align:start position:0% + + + + align:start position:0% + +down that's + + align:start position:0% + + + + align:start position:0% + +fair unit + + align:start position:0% + + + + align:start position:0% + +one now I don't know when this plant + + align:start position:0% +one now I don't know when this plant + + + align:start position:0% +one now I don't know when this plant +came actually started operation but they + + align:start position:0% +came actually started operation but they + + + align:start position:0% +came actually started operation but they +just spent I think was it actually $2 + + align:start position:0% +just spent I think was it actually $2 + + + align:start position:0% +just spent I think was it actually $2 +billion that sounds right to bring the + + align:start position:0% +billion that sounds right to bring the + + + align:start position:0% +billion that sounds right to bring the +plant back into operating + + align:start position:0% +plant back into operating + + + align:start position:0% +plant back into operating +conditions but on March why is it always + + align:start position:0% + + + + align:start position:0% + +March + + align:start position:0% +March + + + align:start position:0% +March +1975 we had the Browns Fair + + align:start position:0% + + + + align:start position:0% + +fire the plant was then in + + align:start position:0% +fire the plant was then in + + + align:start position:0% +fire the plant was then in +operation and they were trying to fix + + align:start position:0% +operation and they were trying to fix + + + align:start position:0% +operation and they were trying to fix +leaks + + align:start position:0% +leaks + + + align:start position:0% +leaks +in in the + + align:start position:0% +in in the + + + align:start position:0% +in in the +containment and between the containment + + align:start position:0% +containment and between the containment + + + align:start position:0% +containment and between the containment +and the outside and they were using a + + align:start position:0% +and the outside and they were using a + + + align:start position:0% +and the outside and they were using a +candle to see if any air was coming + + align:start position:0% + + + + align:start position:0% + +in well the candle worked they were able + + align:start position:0% +in well the candle worked they were able + + + align:start position:0% +in well the candle worked they were able +to detect air but the candle caught the + + align:start position:0% +to detect air but the candle caught the + + + align:start position:0% +to detect air but the candle caught the +insulation on + + align:start position:0% +insulation on + + + align:start position:0% +insulation on +fire which lasted + + align:start position:0% +fire which lasted + + + align:start position:0% +fire which lasted +for how many + + align:start position:0% +for how many + + + align:start position:0% +for how many +hours 7 + + align:start position:0% +hours 7 + + + align:start position:0% +hours 7 +hours + + align:start position:0% + + + + align:start position:0% + +during that time as you might + + align:start position:0% +during that time as you might + + + align:start position:0% +during that time as you might +imagine and and they had this in the + + align:start position:0% +imagine and and they had this in the + + + align:start position:0% +imagine and and they had this in the +cable spreading + + align:start position:0% + + + + align:start position:0% + +room now the cable spreading room we + + align:start position:0% +room now the cable spreading room we + + + align:start position:0% +room now the cable spreading room we +haven't really talked specifically about + + align:start position:0% +haven't really talked specifically about + + + align:start position:0% +haven't really talked specifically about +it but that's the place where all the + + align:start position:0% +it but that's the place where all the + + + align:start position:0% +it but that's the place where all the +power and instrumentation cables come to + + align:start position:0% +power and instrumentation cables come to + + + align:start position:0% +power and instrumentation cables come to +the plant control + + align:start position:0% +the plant control + + + align:start position:0% +the plant control +cables and they ended up + + align:start position:0% +cables and they ended up + + + align:start position:0% +cables and they ended up +burning 1,600 cables + + align:start position:0% + + + + align:start position:0% + +about 628 of them were important to + + align:start position:0% + + + + align:start position:0% + +safy you can imagine what was going on + + align:start position:0% +safy you can imagine what was going on + + + align:start position:0% +safy you can imagine what was going on +in their + + align:start position:0% + + + + align:start position:0% + +minds they essentially disabled many of + + align:start position:0% +minds they essentially disabled many of + + + align:start position:0% +minds they essentially disabled many of +the safety systems and they had to jury + + align:start position:0% +the safety systems and they had to jury + + + align:start position:0% +the safety systems and they had to jury +rig and as I remember using the cooling + + align:start position:0% +rig and as I remember using the cooling + + + align:start position:0% +rig and as I remember using the cooling +from the control rod Drive systems to + + align:start position:0% +from the control rod Drive systems to + + + align:start position:0% +from the control rod Drive systems to +cool + + align:start position:0% + + + + align:start position:0% + +that's how we got Fire Protection in the + + align:start position:0% +that's how we got Fire Protection in the + + + align:start position:0% +that's how we got Fire Protection in the +US + + align:start position:0% +US + + + align:start position:0% +US +industry and as a result of that we have + + align:start position:0% +industry and as a result of that we have + + + align:start position:0% +industry and as a result of that we have +this some people call + + align:start position:0% +this some people call + + + align:start position:0% +this some people call +Infamous other people call Famous + + align:start position:0% +Infamous other people call Famous + + + align:start position:0% +Infamous other people call Famous +appendix + + align:start position:0% + + + + align:start position:0% + +are since Brown's Ferry there has been + + align:start position:0% +are since Brown's Ferry there has been + + + align:start position:0% +are since Brown's Ferry there has been +another fire in the US industry + + align:start position:0% +another fire in the US industry + + + align:start position:0% +another fire in the US industry +affecting safe operation fires and turb + + align:start position:0% +affecting safe operation fires and turb + + + align:start position:0% +affecting safe operation fires and turb +and stuff like that nothing like like + + align:start position:0% +and stuff like that nothing like like + + + align:start position:0% +and stuff like that nothing like like +this so what do they + + align:start position:0% +this so what do they + + + align:start position:0% +this so what do they +require they required again these are + + align:start position:0% +require they required again these are + + + align:start position:0% +require they required again these are +for plants that have already been + + align:start position:0% +for plants that have already been + + + align:start position:0% +for plants that have already been +built and operated to the extent you + + align:start position:0% +built and operated to the extent you + + + align:start position:0% +built and operated to the extent you +could some people separated train a from + + align:start position:0% +could some people separated train a from + + + align:start position:0% +could some people separated train a from +train B Now you kind of know what train + + align:start position:0% +train B Now you kind of know what train + + + align:start position:0% +train B Now you kind of know what train +a and train b means and if you can't + + align:start position:0% +a and train b means and if you can't + + + align:start position:0% +a and train b means and if you can't +separate it because all these things + + align:start position:0% +separate it because all these things + + + align:start position:0% +separate it because all these things +come into the cable spreading room + + align:start position:0% +come into the cable spreading room + + + align:start position:0% +come into the cable spreading room +ultimately wires you have to have + + align:start position:0% +ultimately wires you have to have + + + align:start position:0% +ultimately wires you have to have +insulation specific ific insallation + + align:start position:0% +insulation specific ific insallation + + + align:start position:0% +insulation specific ific insallation +designed to keep to allow for a certain + + align:start position:0% +designed to keep to allow for a certain + + + align:start position:0% +designed to keep to allow for a certain +time before the fire can affect the + + align:start position:0% +time before the fire can affect the + + + align:start position:0% +time before the fire can affect the +wiring uh two 2hour wraps 6 hour wraps + + align:start position:0% +wiring uh two 2hour wraps 6 hour wraps + + + align:start position:0% +wiring uh two 2hour wraps 6 hour wraps +fire doors fire watches and obviously a + + align:start position:0% +fire doors fire watches and obviously a + + + align:start position:0% +fire doors fire watches and obviously a +lot + + align:start position:0% +lot + + + align:start position:0% +lot +of + + align:start position:0% +of + + + align:start position:0% +of +detection and + + align:start position:0% + + + + align:start position:0% + +suppression now with electrical fires + + align:start position:0% +suppression now with electrical fires + + + align:start position:0% +suppression now with electrical fires +you're probably not crazy about throwing + + align:start position:0% +you're probably not crazy about throwing + + + align:start position:0% +you're probably not crazy about throwing +water off them so they had Halon + + align:start position:0% + + + + align:start position:0% + +systems + + align:start position:0% +systems + + + align:start position:0% +systems +Halon and now they use some other type + + align:start position:0% +Halon and now they use some other type + + + align:start position:0% +Halon and now they use some other type +of material that's more environmentally + + align:start position:0% +of material that's more environmentally + + + align:start position:0% +of material that's more environmentally +friendly but this when this thing goes + + align:start position:0% +friendly but this when this thing goes + + + align:start position:0% +friendly but this when this thing goes +off you don't want to be in that room + + align:start position:0% +off you don't want to be in that room + + + align:start position:0% +off you don't want to be in that room +because you can't breathe it you + + align:start position:0% +because you can't breathe it you + + + align:start position:0% +because you can't breathe it you +got um some rooms don't have any + + align:start position:0% +got um some rooms don't have any + + + align:start position:0% +got um some rooms don't have any +equipment and they hand hand um hand + + align:start position:0% +equipment and they hand hand um hand + + + align:start position:0% +equipment and they hand hand um hand +fighting in some + + align:start position:0% +fighting in some + + + align:start position:0% +fighting in some +places but you do and end up doing + + align:start position:0% +places but you do and end up doing + + + align:start position:0% +places but you do and end up doing +as as the appendix art um approach + + align:start position:0% +as as the appendix art um approach + + + align:start position:0% +as as the appendix art um approach +changed they started using fire + + align:start position:0% +changed they started using fire + + + align:start position:0% +changed they started using fire +PR + + align:start position:0% +PR + + + align:start position:0% +PR +identifying how what the likelihood of a + + align:start position:0% +identifying how what the likelihood of a + + + align:start position:0% +identifying how what the likelihood of a +fire is and what the consequences of + + align:start position:0% +fire is and what the consequences of + + + align:start position:0% +fire is and what the consequences of +that fire may be the consequences are + + align:start position:0% +that fire may be the consequences are + + + align:start position:0% +that fire may be the consequences are +important so you're looking at a fire + + align:start position:0% +important so you're looking at a fire + + + align:start position:0% +important so you're looking at a fire +hazards + + align:start position:0% + + + + align:start position:0% + +analysis which + + align:start position:0% +analysis which + + + align:start position:0% +analysis which +includes likelihood and consequences of + + align:start position:0% +includes likelihood and consequences of + + + align:start position:0% +includes likelihood and consequences of +the fire on + + align:start position:0% +the fire on + + + align:start position:0% +the fire on +safety and obviously you have fire + + align:start position:0% +safety and obviously you have fire + + + align:start position:0% +safety and obviously you have fire +loading + + align:start position:0% +loading + + + align:start position:0% +loading +issues especially during outages I'm + + align:start position:0% +issues especially during outages I'm + + + align:start position:0% +issues especially during outages I'm +sure you're all familiar with these + + align:start position:0% +sure you're all familiar with these + + + align:start position:0% +sure you're all familiar with these +major fires that occur at churches + + align:start position:0% +major fires that occur at churches + + + align:start position:0% +major fires that occur at churches +people are doing repairs on the church + + align:start position:0% +people are doing repairs on the church + + + align:start position:0% +people are doing repairs on the church +they burn the whole church down well + + align:start position:0% +they burn the whole church down well + + + align:start position:0% +they burn the whole church down well +during outages this becomes very + + align:start position:0% +during outages this becomes very + + + align:start position:0% +during outages this becomes very +sensitive because you're this at this at + + align:start position:0% +sensitive because you're this at this at + + + align:start position:0% +sensitive because you're this at this at +this point you're in fact working + + align:start position:0% +this point you're in fact working + + + align:start position:0% +this point you're in fact working +potentially with uh welding equipment + + align:start position:0% +potentially with uh welding equipment + + + align:start position:0% +potentially with uh welding equipment +and stuff like that very very serious + + align:start position:0% +and stuff like that very very serious + + + align:start position:0% +and stuff like that very very serious +concern and people have done a lot to + + align:start position:0% +concern and people have done a lot to + + + align:start position:0% +concern and people have done a lot to +try to control fire loadings in these + + align:start position:0% +try to control fire loadings in these + + + align:start position:0% +try to control fire loadings in these +areas but to this to this day it's not a + + align:start position:0% +areas but to this to this day it's not a + + + align:start position:0% +areas but to this to this day it's not a +settled + + align:start position:0% +settled + + + align:start position:0% +settled +case um so they've replaced some of this + + align:start position:0% +case um so they've replaced some of this + + + align:start position:0% +case um so they've replaced some of this +deterministic analysis with a + + align:start position:0% +deterministic analysis with a + + + align:start position:0% +deterministic analysis with a +probabilistic analysis using the tool of + + align:start position:0% +probabilistic analysis using the tool of + + + align:start position:0% +probabilistic analysis using the tool of +fire hazards analysis identifying risk + + align:start position:0% +fire hazards analysis identifying risk + + + align:start position:0% +fire hazards analysis identifying risk +significant systems and then apply your + + align:start position:0% +significant systems and then apply your + + + align:start position:0% +significant systems and then apply your +uh mitigation or prevention system + + align:start position:0% +uh mitigation or prevention system + + + align:start position:0% +uh mitigation or prevention system +accordingly in the process the NRC is + + align:start position:0% +accordingly in the process the NRC is + + + align:start position:0% +accordingly in the process the NRC is +done some tests with some of this + + align:start position:0% +done some tests with some of this + + + align:start position:0% +done some tests with some of this +insulation it was supposed to be fire + + align:start position:0% +insulation it was supposed to be fire + + + align:start position:0% +insulation it was supposed to be fire +ra and I don't know if you were here we + + align:start position:0% +ra and I don't know if you were here we + + + align:start position:0% +ra and I don't know if you were here we +had one of the fellows from the NRC come + + align:start position:0% +had one of the fellows from the NRC come + + + align:start position:0% +had one of the fellows from the NRC come +by and a member asked about this hch + + align:start position:0% +by and a member asked about this hch + + + align:start position:0% +by and a member asked about this hch +insulation which was used routinely in + + align:start position:0% +insulation which was used routinely in + + + align:start position:0% +insulation which was used routinely in +many of these plants and when the NRC + + align:start position:0% +many of these plants and when the NRC + + + align:start position:0% +many of these plants and when the NRC +tested it they found that it didn't do + + align:start position:0% +tested it they found that it didn't do + + + align:start position:0% +tested it they found that it didn't do +its 2hour job it melted the covering of + + align:start position:0% +its 2hour job it melted the covering of + + + align:start position:0% +its 2hour job it melted the covering of +the insulation mounted allowing exposure + + align:start position:0% +the insulation mounted allowing exposure + + + align:start position:0% +the insulation mounted allowing exposure +to the actual cables which then would + + align:start position:0% +to the actual cables which then would + + + align:start position:0% +to the actual cables which then would +have + + align:start position:0% +have + + + align:start position:0% +have +burned um the NRC has has now dealing + + align:start position:0% +burned um the NRC has has now dealing + + + align:start position:0% +burned um the NRC has has now dealing +with this because this is again in many + + align:start position:0% +with this because this is again in many + + + align:start position:0% +with this because this is again in many +of the plants and I think the most + + align:start position:0% +of the plants and I think the most + + + align:start position:0% +of the plants and I think the most +recent + + align:start position:0% +recent + + + align:start position:0% +recent +determination is relative to this H mix + + align:start position:0% +determination is relative to this H mix + + + align:start position:0% +determination is relative to this H mix +stuff is that they and they issued + + align:start position:0% +stuff is that they and they issued + + + align:start position:0% +stuff is that they and they issued +another generic letter so you can see + + align:start position:0% +another generic letter so you can see + + + align:start position:0% +another generic letter so you can see +how recent this is generic letter 2006 + + align:start position:0% + + + + align:start position:0% + +D3 for the lenses to evaluate this and + + align:start position:0% +D3 for the lenses to evaluate this and + + + align:start position:0% +D3 for the lenses to evaluate this and +take compensatory action should should + + align:start position:0% +take compensatory action should should + + + align:start position:0% +take compensatory action should should +they find a lot of this in key areas + + align:start position:0% +they find a lot of this in key areas + + + align:start position:0% +they find a lot of this in key areas +based on the fire hasard analysis and + + align:start position:0% +based on the fire hasard analysis and + + + align:start position:0% +based on the fire hasard analysis and +compensatory action could be putting + + align:start position:0% +compensatory action could be putting + + + align:start position:0% +compensatory action could be putting +somebody in the room where this + + align:start position:0% +somebody in the room where this + + + align:start position:0% +somebody in the room where this +insulation is and sitting there and + + align:start position:0% +insulation is and sitting there and + + + align:start position:0% +insulation is and sitting there and +watch it if there's a fire then you push + + align:start position:0% +watch it if there's a fire then you push + + + align:start position:0% +watch it if there's a fire then you push +the + + align:start position:0% +the + + + align:start position:0% +the +fire U that's a little more Draconian + + align:start position:0% +fire U that's a little more Draconian + + + align:start position:0% +fire U that's a little more Draconian +but that's a quick action but they + + align:start position:0% +but that's a quick action but they + + + align:start position:0% +but that's a quick action but they +conclude that in areas where there's + + align:start position:0% +conclude that in areas where there's + + + align:start position:0% +conclude that in areas where there's +both fire detection and automatic + + align:start position:0% +both fire detection and automatic + + + align:start position:0% +both fire detection and automatic +suppression even with you have this + + align:start position:0% +suppression even with you have this + + + align:start position:0% +suppression even with you have this +stuff the NRC remains I'm quoting + + align:start position:0% +stuff the NRC remains I'm quoting + + + align:start position:0% +stuff the NRC remains I'm quoting +assured that those plants overall fire + + align:start position:0% +assured that those plants overall fire + + + align:start position:0% +assured that those plants overall fire +protection scheme will ensure the safe + + align:start position:0% +protection scheme will ensure the safe + + + align:start position:0% +protection scheme will ensure the safe +shutdown of the reactor so if you have + + align:start position:0% +shutdown of the reactor so if you have + + + align:start position:0% +shutdown of the reactor so if you have +this stuff you would end up replacing it + + align:start position:0% +this stuff you would end up replacing it + + + align:start position:0% +this stuff you would end up replacing it +and you're probably if you don't have + + align:start position:0% +and you're probably if you don't have + + + align:start position:0% +and you're probably if you don't have +detection and suppression in that same + + align:start position:0% +detection and suppression in that same + + + align:start position:0% +detection and suppression in that same +mode you're going to have to do it + + align:start position:0% +mode you're going to have to do it + + + align:start position:0% +mode you're going to have to do it +so that's fire + + align:start position:0% +so that's fire + + + align:start position:0% +so that's fire +protection and the fire Pras is + + align:start position:0% +protection and the fire Pras is + + + align:start position:0% +protection and the fire Pras is +something still people are trying to + + align:start position:0% +something still people are trying to + + + align:start position:0% +something still people are trying to +work + + align:start position:0% +work + + + align:start position:0% +work +through they have other other types of + + align:start position:0% +through they have other other types of + + + align:start position:0% +through they have other other types of +fire uh protection equipment there's + + align:start position:0% +fire uh protection equipment there's + + + align:start position:0% +fire uh protection equipment there's +lots of thermal lag is another brand but + + align:start position:0% +lots of thermal lag is another brand but + + + align:start position:0% +lots of thermal lag is another brand but +that's sort of been resolved as best I + + align:start position:0% +that's sort of been resolved as best I + + + align:start position:0% +that's sort of been resolved as best I +can + + align:start position:0% +can + + + align:start position:0% +can +tell any questions on this + + align:start position:0% +tell any questions on this + + + align:start position:0% +tell any questions on this +one okay this is Ashley's + + align:start position:0% +one okay this is Ashley's + + + align:start position:0% +one okay this is Ashley's +fav Ashley did a study some years ago + + align:start position:0% +fav Ashley did a study some years ago + + + align:start position:0% +fav Ashley did a study some years ago +about an airplane crashing into a + + align:start position:0% +about an airplane crashing into a + + + align:start position:0% +about an airplane crashing into a +nuclear + + align:start position:0% +nuclear + + + align:start position:0% +nuclear +car and + + align:start position:0% +car and + + + align:start position:0% +car and +um as a result of 911 they have turned + + align:start position:0% +um as a result of 911 they have turned + + + align:start position:0% +um as a result of 911 they have turned +nuclear power + + align:start position:0% +nuclear power + + + align:start position:0% +nuclear power +plants into what does this remind you + + align:start position:0% + + + + align:start position:0% + +of prison prison they' have turned + + align:start position:0% +of prison prison they' have turned + + + align:start position:0% +of prison prison they' have turned +nuclear power plants into prisons and + + align:start position:0% +nuclear power plants into prisons and + + + align:start position:0% +nuclear power plants into prisons and +this is probably normally you'd see + + align:start position:0% +this is probably normally you'd see + + + align:start position:0% +this is probably normally you'd see +razor wire here and a couple of + + align:start position:0% +razor wire here and a couple of + + + align:start position:0% +razor wire here and a couple of +fences and I think you see some razor + + align:start position:0% +fences and I think you see some razor + + + align:start position:0% +fences and I think you see some razor +wire here so there's at least an outer + + align:start position:0% +wire here so there's at least an outer + + + align:start position:0% +wire here so there's at least an outer +fence and inner fence separated by + + align:start position:0% +fence and inner fence separated by + + + align:start position:0% +fence and inner fence separated by +motion + + align:start position:0% +motion + + + align:start position:0% +motion +detectors and uh electrified wire + + align:start position:0% +detectors and uh electrified wire + + + align:start position:0% +detectors and uh electrified wire +potentially and you have these pill + + align:start position:0% +potentially and you have these pill + + + align:start position:0% +potentially and you have these pill +boxes on the + + align:start position:0% +boxes on the + + + align:start position:0% +boxes on the +site now these pill boxes are + + align:start position:0% +site now these pill boxes are + + + align:start position:0% +site now these pill boxes are +positioned so that if anybody decides to + + align:start position:0% +positioned so that if anybody decides to + + + align:start position:0% +positioned so that if anybody decides to +come on the site with a gun and try to + + align:start position:0% +come on the site with a gun and try to + + + align:start position:0% +come on the site with a gun and try to +take over that facility this person + + align:start position:0% +take over that facility this person + + + align:start position:0% +take over that facility this person +or persons can kill that person anywhere + + align:start position:0% +or persons can kill that person anywhere + + + align:start position:0% +or persons can kill that person anywhere +on the property before they get + + align:start position:0% +on the property before they get + + + align:start position:0% +on the property before they get +endorsed so if you go to santrey the + + align:start position:0% +endorsed so if you go to santrey the + + + align:start position:0% +endorsed so if you go to santrey the +plant that I'm most familiar with in the + + align:start position:0% +plant that I'm most familiar with in the + + + align:start position:0% +plant that I'm most familiar with in the +states that where I observed this they + + align:start position:0% +states that where I observed this they + + + align:start position:0% +states that where I observed this they +have I don't know how many of these + + align:start position:0% +have I don't know how many of these + + + align:start position:0% +have I don't know how many of these +around but it's very clear it's lit up + + align:start position:0% +around but it's very clear it's lit up + + + align:start position:0% +around but it's very clear it's lit up +at night and you're not getting in this + + align:start position:0% +at night and you're not getting in this + + + align:start position:0% +at night and you're not getting in this +place and if if you think you're going + + align:start position:0% +place and if if you think you're going + + + align:start position:0% +place and if if you think you're going +to be carrying a gun in there you're + + align:start position:0% +to be carrying a gun in there you're + + + align:start position:0% +to be carrying a gun in there you're +going to die there's no there's no issue + + align:start position:0% +going to die there's no there's no issue + + + align:start position:0% +going to die there's no there's no issue +at Yankee our our security staff I was + + align:start position:0% +at Yankee our our security staff I was + + + align:start position:0% +at Yankee our our security staff I was +not comfortable with these guys having + + align:start position:0% +not comfortable with these guys having + + + align:start position:0% +not comfortable with these guys having +guns in the + + align:start position:0% +guns in the + + + align:start position:0% +guns in the +controller you never know when a worker + + align:start position:0% +controller you never know when a worker + + + align:start position:0% +controller you never know when a worker +got an issue even though you do all + + align:start position:0% +got an issue even though you do all + + + align:start position:0% +got an issue even though you do all +kinds of s profiling whatever a gun in + + align:start position:0% +kinds of s profiling whatever a gun in + + + align:start position:0% +kinds of s profiling whatever a gun in +the controling wasn't a good idea but + + align:start position:0% +the controling wasn't a good idea but + + + align:start position:0% +the controling wasn't a good idea but +the NC said you must have + + align:start position:0% +the NC said you must have + + + align:start position:0% +the NC said you must have +guns hand and you know it's it's it's + + align:start position:0% +guns hand and you know it's it's it's + + + align:start position:0% +guns hand and you know it's it's it's +really you look at some of these rifles + + align:start position:0% +really you look at some of these rifles + + + align:start position:0% +really you look at some of these rifles +they're well armed well so they had to + + align:start position:0% +they're well armed well so they had to + + + align:start position:0% +they're well armed well so they had to +upgrade the physical + + align:start position:0% +upgrade the physical + + + align:start position:0% +upgrade the physical +security it's not a welcoming place to + + align:start position:0% +security it's not a welcoming place to + + + align:start position:0% +security it's not a welcoming place to +go + + align:start position:0% +go + + + align:start position:0% +go +you have to show that your particular + + align:start position:0% +you have to show that your particular + + + align:start position:0% +you have to show that your particular +plant is capable of being you know + + align:start position:0% +plant is capable of being you know + + + align:start position:0% +plant is capable of being you know +withstand a aircraft impact and had we + + align:start position:0% +withstand a aircraft impact and had we + + + align:start position:0% +withstand a aircraft impact and had we +had more time we can show you some of + + align:start position:0% +had more time we can show you some of + + + align:start position:0% +had more time we can show you some of +the issues that we looked at with Ashley + + align:start position:0% +the issues that we looked at with Ashley + + + align:start position:0% +the issues that we looked at with Ashley +some years ago about it's not just about + + align:start position:0% +some years ago about it's not just about + + + align:start position:0% +some years ago about it's not just about +the containment it's about other things + + align:start position:0% +the containment it's about other things + + + align:start position:0% +the containment it's about other things +that could be + + align:start position:0% +that could be + + + align:start position:0% +that could be +damaged and then they have these the + + align:start position:0% +damaged and then they have these the + + + align:start position:0% +damaged and then they have these the +things called design bases threats which + + align:start position:0% +things called design bases threats which + + + align:start position:0% +things called design bases threats which +are imagine a certain type of intruder + + align:start position:0% +are imagine a certain type of intruder + + + align:start position:0% +are imagine a certain type of intruder +or intruder + + align:start position:0% +or intruder + + + align:start position:0% +or intruder +you have to be able to repel these + + align:start position:0% +you have to be able to repel these + + + align:start position:0% +you have to be able to repel these +people at least for a time until you get + + align:start position:0% +people at least for a time until you get + + + align:start position:0% +people at least for a time until you get +the Army Navy Marines airport whatever + + align:start position:0% +the Army Navy Marines airport whatever + + + align:start position:0% +the Army Navy Marines airport whatever +local police to + + align:start position:0% +local police to + + + align:start position:0% +local police to +come true and this design basis threat + + align:start position:0% +come true and this design basis threat + + + align:start position:0% +come true and this design basis threat +is continuing continuing to be evolv + + align:start position:0% +is continuing continuing to be evolv + + + align:start position:0% +is continuing continuing to be evolv +based on what the sophistication of the + + align:start position:0% +based on what the sophistication of the + + + align:start position:0% +based on what the sophistication of the +terrorist could be and they have not a + + align:start position:0% +terrorist could be and they have not a + + + align:start position:0% +terrorist could be and they have not a +lot of am of course but they do have + + align:start position:0% +lot of am of course but they do have + + + align:start position:0% +lot of am of course but they do have +people assaulting the plants and you do + + align:start position:0% +people assaulting the plants and you do + + + align:start position:0% +people assaulting the plants and you do +certain tests and drills every 3 to 5 + + align:start position:0% +certain tests and drills every 3 to 5 + + + align:start position:0% +certain tests and drills every 3 to 5 +years + + align:start position:0% +years + + + align:start position:0% +years +uh the themee of this is not that we're + + align:start position:0% +uh the themee of this is not that we're + + + align:start position:0% +uh the themee of this is not that we're +going to be able to um it's it's not the + + align:start position:0% +going to be able to um it's it's not the + + + align:start position:0% +going to be able to um it's it's not the +utility's job to fend off the Intruder + + align:start position:0% +utility's job to fend off the Intruder + + + align:start position:0% +utility's job to fend off the Intruder +or or knock them out it's the it's the + + align:start position:0% +or or knock them out it's the it's the + + + align:start position:0% +or or knock them out it's the it's the +military's job and the police job to + + align:start position:0% +military's job and the police job to + + + align:start position:0% +military's job and the police job to +assist their job is only to hold off to + + align:start position:0% +assist their job is only to hold off to + + + align:start position:0% +assist their job is only to hold off to +avoid them getting into the critical + + align:start position:0% +avoid them getting into the critical + + + align:start position:0% +avoid them getting into the critical +areas of land and you know some people + + align:start position:0% +areas of land and you know some people + + + align:start position:0% +areas of land and you know some people +will say why don't we put missile + + align:start position:0% +will say why don't we put missile + + + align:start position:0% +will say why don't we put missile +batteries at some of these nuclear power + + align:start position:0% +batteries at some of these nuclear power + + + align:start position:0% +batteries at some of these nuclear power +to shoot down airplanes and the answer + + align:start position:0% +to shoot down airplanes and the answer + + + align:start position:0% +to shoot down airplanes and the answer +is that's not our job the job is that of + + align:start position:0% +is that's not our job the job is that of + + + align:start position:0% +is that's not our job the job is that of +the federal government to protect any + + align:start position:0% +the federal government to protect any + + + align:start position:0% +the federal government to protect any +installation + + align:start position:0% +installation + + + align:start position:0% +installation +incl so at this point this has been a + + align:start position:0% +incl so at this point this has been a + + + align:start position:0% +incl so at this point this has been a +hugely expensive operation the security + + align:start position:0% +hugely expensive operation the security + + + align:start position:0% +hugely expensive operation the security +staffs are larger than the operating + + align:start position:0% +staffs are larger than the operating + + + align:start position:0% +staffs are larger than the operating +staffs at these plants I'm talking They + + align:start position:0% +staffs at these plants I'm talking They + + + align:start position:0% +staffs at these plants I'm talking They +al also do 247 + + align:start position:0% +al also do 247 + + + align:start position:0% +al also do 247 +365 so this is a huge new expense and + + align:start position:0% +365 so this is a huge new expense and + + + align:start position:0% +365 so this is a huge new expense and +these guys have to be TR and + + align:start position:0% +these guys have to be TR and + + + align:start position:0% +these guys have to be TR and +um wel train and you've seen some recent + + align:start position:0% +um wel train and you've seen some recent + + + align:start position:0% +um wel train and you've seen some recent +stories about guard sleeping on the job + + align:start position:0% +stories about guard sleeping on the job + + + align:start position:0% +stories about guard sleeping on the job +obviously that's not + + align:start position:0% +obviously that's not + + + align:start position:0% +obviously that's not +acceptable any questions on this + + align:start position:0% + + + + align:start position:0% + +one groundwater + + align:start position:0% + + + + align:start position:0% + +contamination this is a surprising + + align:start position:0% +contamination this is a surprising + + + align:start position:0% +contamination this is a surprising +thing but it occurs + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +typically I don't know if you remember + + align:start position:0% +typically I don't know if you remember + + + align:start position:0% +typically I don't know if you remember +but this is about five or six years ago + + align:start position:0% +but this is about five or six years ago + + + align:start position:0% +but this is about five or six years ago +Brook Haven National Lab had a I think + + align:start position:0% +Brook Haven National Lab had a I think + + + align:start position:0% +Brook Haven National Lab had a I think +it was in + + align:start position:0% +it was in + + + align:start position:0% +it was in +there um fueling water storage tank or + + align:start position:0% +there um fueling water storage tank or + + + align:start position:0% +there um fueling water storage tank or +some tank containing trated water leaked + + align:start position:0% +some tank containing trated water leaked + + + align:start position:0% +some tank containing trated water leaked +and Brook Haven is all on out in a nice + + align:start position:0% +and Brook Haven is all on out in a nice + + + align:start position:0% +and Brook Haven is all on out in a nice +area Mid Island other words Island 12 + + align:start position:0% +area Mid Island other words Island 12 + + + align:start position:0% +area Mid Island other words Island 12 +maybe + + align:start position:0% +maybe + + + align:start position:0% +maybe +out in a in a nice residential area it's + + align:start position:0% +out in a in a nice residential area it's + + + align:start position:0% +out in a in a nice residential area it's +a nice research thatb they had a leap + + align:start position:0% +a nice research thatb they had a leap + + + align:start position:0% +a nice research thatb they had a leap +from one of their earlier operting rings + + align:start position:0% +from one of their earlier operting rings + + + align:start position:0% +from one of their earlier operting rings +and it was trigged very low + + align:start position:0% +and it was trigged very low + + + align:start position:0% +and it was trigged very low +level that you know did not exceed the + + align:start position:0% +level that you know did not exceed the + + + align:start position:0% +level that you know did not exceed the +drinking water standard but they had + + align:start position:0% +drinking water standard but they had + + + align:start position:0% +drinking water standard but they had +such a bruha they almost shut the laab + + align:start position:0% +such a bruha they almost shut the laab + + + align:start position:0% +such a bruha they almost shut the laab +down because of the public out Manny it + + align:start position:0% +down because of the public out Manny it + + + align:start position:0% +down because of the public out Manny it +be shut down and it changed the lab it + + align:start position:0% +be shut down and it changed the lab it + + + align:start position:0% +be shut down and it changed the lab it +used to be a nuclear energy lab story in + + align:start position:0% +used to be a nuclear energy lab story in + + + align:start position:0% +used to be a nuclear energy lab story in +part now it's pretty much a basic + + align:start position:0% +part now it's pretty much a basic + + + align:start position:0% +part now it's pretty much a basic +science level but they had a lot of + + align:start position:0% +science level but they had a lot of + + + align:start position:0% +science level but they had a lot of +reactors there they had high temperature + + align:start position:0% +reactors there they had high temperature + + + align:start position:0% +reactors there they had high temperature +uh fast flux + + align:start position:0% +uh fast flux + + + align:start position:0% +uh fast flux +reactor uh they also had some graphite + + align:start position:0% +reactor uh they also had some graphite + + + align:start position:0% +reactor uh they also had some graphite +reactors so they were one of early + + align:start position:0% +reactors so they were one of early + + + align:start position:0% +reactors so they were one of early +Pioneers because of this very low level + + align:start position:0% +Pioneers because of this very low level + + + align:start position:0% +Pioneers because of this very low level +of trium getting into the groundwater + + align:start position:0% +of trium getting into the groundwater + + + align:start position:0% +of trium getting into the groundwater +and migrating it shut it shut almost + + align:start position:0% +and migrating it shut it shut almost + + + align:start position:0% +and migrating it shut it shut almost +shut the re shut the laboratory + + align:start position:0% +shut the re shut the laboratory + + + align:start position:0% +shut the re shut the laboratory +down in the nuclear World we've had + + align:start position:0% +down in the nuclear World we've had + + + align:start position:0% +down in the nuclear World we've had +leaks at Indian Point Braidwood cage + + align:start position:0% +leaks at Indian Point Braidwood cage + + + align:start position:0% +leaks at Indian Point Braidwood cage +resin bar out in C and + + align:start position:0% +resin bar out in C and + + + align:start position:0% +resin bar out in C and +Cal again a lot of it coming from the + + align:start position:0% +Cal again a lot of it coming from the + + + align:start position:0% +Cal again a lot of it coming from the +spend fuel where you know trated water + + align:start position:0% +spend fuel where you know trated water + + + align:start position:0% +spend fuel where you know trated water +does does + + align:start position:0% +does does + + + align:start position:0% +does does +occur um and in some cases it came like + + align:start position:0% +occur um and in some cases it came like + + + align:start position:0% +occur um and in some cases it came like +in in Braidwood from um I think they had + + align:start position:0% +in in Braidwood from um I think they had + + + align:start position:0% +in in Braidwood from um I think they had +leakage in some of their vacuum valves + + align:start position:0% +leakage in some of their vacuum valves + + + align:start position:0% +leakage in some of their vacuum valves +on their on on the secondary side on the + + align:start position:0% +on their on on the secondary side on the + + + align:start position:0% +on their on on the secondary side on the +primary side of their + + align:start position:0% +primary side of their + + + align:start position:0% +primary side of their +plant uh and + + align:start position:0% +plant uh and + + + align:start position:0% +plant uh and +the the leakage was + + align:start position:0% +the the leakage was + + + align:start position:0% +the the leakage was +known not reported on time and when + + align:start position:0% +known not reported on time and when + + + align:start position:0% +known not reported on time and when +reported uh created a huge stir in the + + align:start position:0% +reported uh created a huge stir in the + + + align:start position:0% +reported uh created a huge stir in the +local + + align:start position:0% +local + + + align:start position:0% +local +population what they had to do at Brook + + align:start position:0% +population what they had to do at Brook + + + align:start position:0% +population what they had to do at Brook +Haven was drill monitoring + + align:start position:0% +Haven was drill monitoring + + + align:start position:0% +Haven was drill monitoring +Wells and suck up the + + align:start position:0% +Wells and suck up the + + + align:start position:0% +Wells and suck up the +water now trium you know you can't + + align:start position:0% +water now trium you know you can't + + + align:start position:0% +water now trium you know you can't +really do much with + + align:start position:0% +really do much with + + + align:start position:0% +really do much with +it what they did with that water I don't + + align:start position:0% +it what they did with that water I don't + + + align:start position:0% +it what they did with that water I don't +know but they were pumping the + + align:start position:0% +know but they were pumping the + + + align:start position:0% +know but they were pumping the +water uh + + align:start position:0% +water uh + + + align:start position:0% +water uh +and maybe storing it don't know they're + + align:start position:0% +and maybe storing it don't know they're + + + align:start position:0% +and maybe storing it don't know they're +apparently going to be doing the same at + + align:start position:0% +apparently going to be doing the same at + + + align:start position:0% +apparently going to be doing the same at +these Lees now this this rawood plant + + align:start position:0% +these Lees now this this rawood plant + + + align:start position:0% +these Lees now this this rawood plant +actually got a notice of + + align:start position:0% +actually got a notice of + + + align:start position:0% +actually got a notice of +violation this was issued in uh + + align:start position:0% +violation this was issued in uh + + + align:start position:0% +violation this was issued in uh +2006 and the violation basically cited + + align:start position:0% +2006 and the violation basically cited + + + align:start position:0% +2006 and the violation basically cited +them for under part 20 which is this + + align:start position:0% +them for under part 20 which is this + + + align:start position:0% +them for under part 20 which is this +radi electrical e part was they did not + + align:start position:0% +radi electrical e part was they did not + + + align:start position:0% +radi electrical e part was they did not +make the necessary surveys to identify + + align:start position:0% +make the necessary surveys to identify + + + align:start position:0% +make the necessary surveys to identify +the + + align:start position:0% +the + + + align:start position:0% +the +people uh + + align:start position:0% +people uh + + + align:start position:0% +people uh +um they were not assuring that the + + align:start position:0% +um they were not assuring that the + + + align:start position:0% +um they were not assuring that the +public got less + + align:start position:0% +public got less + + + align:start position:0% +public got less +than point one this number is REM + + align:start position:0% +than point one this number is REM + + + align:start position:0% +than point one this number is REM +perier had no way to assure even though + + align:start position:0% +perier had no way to assure even though + + + align:start position:0% +perier had no way to assure even though +I didn't get + + align:start position:0% +I didn't get + + + align:start position:0% +I didn't get +it + + align:start position:0% +it + + + align:start position:0% +it +um and there were failure their failure + + align:start position:0% +um and there were failure their failure + + + align:start position:0% +um and there were failure their failure +was largely to identify Le and deal with + + align:start position:0% +was largely to identify Le and deal with + + + align:start position:0% +was largely to identify Le and deal with +they just kind of ignored it they did + + align:start position:0% +they just kind of ignored it they did + + + align:start position:0% +they just kind of ignored it they did +release million gallons of + + align:start position:0% +release million gallons of + + + align:start position:0% +release million gallons of +water a lot a lot of water over + + align:start position:0% +water a lot a lot of water over + + + align:start position:0% +water a lot a lot of water over +time um and this went back from November + + align:start position:0% +time um and this went back from November + + + align:start position:0% +time um and this went back from November +1996 to March + + align:start position:0% +1996 to March + + + align:start position:0% +1996 to March +2006 so it's not that + + align:start position:0% +2006 so it's not that + + + align:start position:0% +2006 so it's not that +they didn't know was happen it's just + + align:start position:0% +they didn't know was happen it's just + + + align:start position:0% +they didn't know was happen it's just +that they failed to properly report it + + align:start position:0% +that they failed to properly report it + + + align:start position:0% +that they failed to properly report it +and failed to deal with it + + align:start position:0% +and failed to deal with it + + + align:start position:0% +and failed to deal with it +um and they had a numerous leaks over + + align:start position:0% +um and they had a numerous leaks over + + + align:start position:0% +um and they had a numerous leaks over +over that time period the largest of + + align:start position:0% +over that time period the largest of + + + align:start position:0% +over that time period the largest of +which was 3 3 million gallons to ground + + align:start position:0% +which was 3 3 million gallons to ground + + + align:start position:0% +which was 3 3 million gallons to ground +path ground path the industry of course + + align:start position:0% +path ground path the industry of course + + + align:start position:0% +path ground path the industry of course +responded to do this this the other + + align:start position:0% +responded to do this this the other + + + align:start position:0% +responded to do this this the other +things but most nuclear plants have + + align:start position:0% +things but most nuclear plants have + + + align:start position:0% +things but most nuclear plants have +monitoring R but not where apparently + + align:start position:0% +monitoring R but not where apparently + + + align:start position:0% +monitoring R but not where apparently +this particular Le occur and remember + + align:start position:0% +this particular Le occur and remember + + + align:start position:0% +this particular Le occur and remember +the + + align:start position:0% +the + + + align:start position:0% +the +um the reactor oversight + + align:start position:0% + + + + align:start position:0% + +process they got a white + + align:start position:0% +process they got a white + + + align:start position:0% +process they got a white +finding and that white finding triggered + + align:start position:0% +finding and that white finding triggered + + + align:start position:0% +finding and that white finding triggered +this investigation and they then also + + align:start position:0% +this investigation and they then also + + + align:start position:0% +this investigation and they then also +triggered this parent violation I don't + + align:start position:0% +triggered this parent violation I don't + + + align:start position:0% +triggered this parent violation I don't +know what the the fine + + align:start position:0% +know what the the fine + + + align:start position:0% +know what the the fine +was but my guess is they probably got + + align:start position:0% +was but my guess is they probably got + + + align:start position:0% +was but my guess is they probably got +one + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +so okay so here's what they what they + + align:start position:0% +so okay so here's what they what they + + + align:start position:0% +so okay so here's what they what they +had to do public got really + + align:start position:0% +had to do public got really + + + align:start position:0% +had to do public got really +outraged usual demands that trying to be + + align:start position:0% +outraged usual demands that trying to be + + + align:start position:0% +outraged usual demands that trying to be +shut down + + align:start position:0% +shut down + + + align:start position:0% +shut down +the report they didn't think that this + + align:start position:0% +the report they didn't think that this + + + align:start position:0% +the report they didn't think that this +leak was in within the reportable + + align:start position:0% +leak was in within the reportable + + + align:start position:0% +leak was in within the reportable +domain and unfortunately it was they + + align:start position:0% +domain and unfortunately it was they + + + align:start position:0% +domain and unfortunately it was they +have what they + + align:start position:0% +have what they + + + align:start position:0% +have what they +call radiological e textbooks rats and + + align:start position:0% +call radiological e textbooks rats and + + + align:start position:0% +call radiological e textbooks rats and +under those text specs they should have + + align:start position:0% +under those text specs they should have + + + align:start position:0% +under those text specs they should have +routinely reported even smalles which + + align:start position:0% +routinely reported even smalles which + + + align:start position:0% +routinely reported even smalles which +they chose not to + + align:start position:0% +they chose not to + + + align:start position:0% +they chose not to +do but even though the levels were low + + align:start position:0% +do but even though the levels were low + + + align:start position:0% +do but even though the levels were low +they had a problem let me take a minute + + align:start position:0% +they had a problem let me take a minute + + + align:start position:0% +they had a problem let me take a minute +to do the enforcement process which I + + align:start position:0% +to do the enforcement process which I + + + align:start position:0% +to do the enforcement process which I +think is is + + align:start position:0% +think is is + + + align:start position:0% +think is is +interesting for minor minor violations + + align:start position:0% +interesting for minor minor violations + + + align:start position:0% +interesting for minor minor violations +these are the things that were found in + + align:start position:0% +these are the things that were found in + + + align:start position:0% +these are the things that were found in +the inspection report still green no + + align:start position:0% +the inspection report still green no + + + align:start position:0% +the inspection report still green no +issues you self-identify they identify + + align:start position:0% +issues you self-identify they identify + + + align:start position:0% +issues you self-identify they identify +not a problem then you get a it says the + + align:start position:0% +not a problem then you get a it says the + + + align:start position:0% +not a problem then you get a it says the +non- escalated process severity level + + align:start position:0% +non- escalated process severity level + + + align:start position:0% +non- escalated process severity level +four they go from one to I think 1 to + + align:start position:0% +four they go from one to I think 1 to + + + align:start position:0% +four they go from one to I think 1 to +five and these are violations and + + align:start position:0% +five and these are violations and + + + align:start position:0% +five and these are violations and +related to Green s significance + + align:start position:0% +related to Green s significance + + + align:start position:0% +related to Green s significance +determination process s DP green + + align:start position:0% +determination process s DP green + + + align:start position:0% +determination process s DP green +findings you're okay but you got to + + align:start position:0% +findings you're okay but you got to + + + align:start position:0% +findings you're okay but you got to +viation did you fail to restore + + align:start position:0% +viation did you fail to restore + + + align:start position:0% +viation did you fail to restore +compliance yes you boom you get it okay + + align:start position:0% +compliance yes you boom you get it okay + + + align:start position:0% +compliance yes you boom you get it okay +we're not even talking you anymore if + + align:start position:0% +we're not even talking you anymore if + + + align:start position:0% +we're not even talking you anymore if +you did if if if if if you failed to + + align:start position:0% +you did if if if if if you failed to + + + align:start position:0% +you did if if if if if you failed to +restore no did you failed to put it in + + align:start position:0% +restore no did you failed to put it in + + + align:start position:0% +restore no did you failed to put it in +the corrective Action Program is it a + + align:start position:0% +the corrective Action Program is it a + + + align:start position:0% +the corrective Action Program is it a +repetitive finding is it + + align:start position:0% +repetitive finding is it + + + align:start position:0% +repetitive finding is it +willful if all these are no in other + + align:start position:0% +willful if all these are no in other + + + align:start position:0% +willful if all these are no in other +words you put in the corrective Action + + align:start position:0% +words you put in the corrective Action + + + align:start position:0% +words you put in the corrective Action +Program you dealt with it responsibly + + align:start position:0% +Program you dealt with it responsibly + + + align:start position:0% +Program you dealt with it responsibly +you're not going to get a violation + + align:start position:0% +you're not going to get a violation + + + align:start position:0% +you're not going to get a violation +it'll be it'll it'll be a violation but + + align:start position:0% +it'll be it'll it'll be a violation but + + + align:start position:0% +it'll be it'll it'll be a violation but +they call + + align:start position:0% +they call + + + align:start position:0% +they call +non-signed you won't get you won't get + + align:start position:0% +non-signed you won't get you won't get + + + align:start position:0% +non-signed you won't get you won't get +ding + + align:start position:0% + + + + align:start position:0% + +for if um for other licenses namely I I + + align:start position:0% +for if um for other licenses namely I I + + + align:start position:0% +for if um for other licenses namely I I +would say that if this was something + + align:start position:0% +would say that if this was something + + + align:start position:0% +would say that if this was something +that you I don't know why this would be + + align:start position:0% +that you I don't know why this would be + + + align:start position:0% +that you I don't know why this would be +other lesson this we're not going to + + align:start position:0% +other lesson this we're not going to + + + align:start position:0% +other lesson this we're not going to +about but if you're an escalated process + + align:start position:0% +about but if you're an escalated process + + + align:start position:0% +about but if you're an escalated process +very level one and two and three + + align:start position:0% +very level one and two and three + + + align:start position:0% +very level one and two and three +violations related to white yellow + + align:start position:0% +violations related to white yellow + + + align:start position:0% +violations related to white yellow +red and a significance determination + + align:start position:0% +red and a significance determination + + + align:start position:0% +red and a significance determination +findings with actual consequence so you + + align:start position:0% +findings with actual consequence so you + + + align:start position:0% +findings with actual consequence so you +got a problem you got an impact and you + + align:start position:0% +got a problem you got an impact and you + + + align:start position:0% +got a problem you got an impact and you +could have a white with a + + align:start position:0% +could have a white with a + + + align:start position:0% +could have a white with a +consequence was it was it say first non + + align:start position:0% +consequence was it was it say first non + + + align:start position:0% +consequence was it was it say first non +willful uh level three in in this period + + align:start position:0% +willful uh level three in in this period + + + align:start position:0% +willful uh level three in in this period +of time yes credit for corrective action + + align:start position:0% +of time yes credit for corrective action + + + align:start position:0% +of time yes credit for corrective action +yes I guess it's it's notice of + + align:start position:0% +yes I guess it's it's notice of + + + align:start position:0% +yes I guess it's it's notice of +violation but no civil penalty civil + + align:start position:0% +violation but no civil penalty civil + + + align:start position:0% +violation but no civil penalty civil +penalty is the + + align:start position:0% +penalty is the + + + align:start position:0% +penalty is the +F from a public perspective getting a + + align:start position:0% +F from a public perspective getting a + + + align:start position:0% +F from a public perspective getting a +notice of violation is not a good thing + + align:start position:0% +notice of violation is not a good thing + + + align:start position:0% +notice of violation is not a good thing +from a public perspective getting a + + align:start position:0% +from a public perspective getting a + + + align:start position:0% +from a public perspective getting a +notice of violation and a civil penalty + + align:start position:0% +notice of violation and a civil penalty + + + align:start position:0% +notice of violation and a civil penalty +shows you're really really not doing + + align:start position:0% +shows you're really really not doing + + + align:start position:0% +shows you're really really not doing +your + + align:start position:0% +your + + + align:start position:0% +your +job so was if was not if it was if it + + align:start position:0% +job so was if was not if it was if it + + + align:start position:0% +job so was if was not if it was if it +was first non willful no did you get + + align:start position:0% +was first non willful no did you get + + + align:start position:0% +was first non willful no did you get +credit for identification then you can + + align:start position:0% +credit for identification then you can + + + align:start position:0% +credit for identification then you can +kind of play this as well + + align:start position:0% +kind of play this as well + + + align:start position:0% +kind of play this as well +if you if if you didn't identify it and + + align:start position:0% +if you if if you didn't identify it and + + + align:start position:0% +if you if if you didn't identify it and +you didn't correct it you're going to + + align:start position:0% +you didn't correct it you're going to + + + align:start position:0% +you didn't correct it you're going to +get hit twice with the base + + align:start position:0% +get hit twice with the base + + + align:start position:0% +get hit twice with the base +Baseline and uh violation right just + + align:start position:0% +Baseline and uh violation right just + + + align:start position:0% +Baseline and uh violation right just +basically just get a no of + + align:start position:0% +basically just get a no of + + + align:start position:0% +basically just get a no of +violation uh so you don't want to be on + + align:start position:0% +violation uh so you don't want to be on + + + align:start position:0% +violation uh so you don't want to be on +this + + align:start position:0% +this + + + align:start position:0% +this +path for sure but this process has has + + align:start position:0% +path for sure but this process has has + + + align:start position:0% +path for sure but this process has has +been very effective at getting the + + align:start position:0% +been very effective at getting the + + + align:start position:0% +been very effective at getting the +utilities focus on trying to improve the + + align:start position:0% +utilities focus on trying to improve the + + + align:start position:0% +utilities focus on trying to improve the +situation um + + align:start position:0% +situation um + + + align:start position:0% +situation um +but violations and fines do + + align:start position:0% +but violations and fines do + + + align:start position:0% +but violations and fines do +occur I've picked up two recent + + align:start position:0% +occur I've picked up two recent + + + align:start position:0% +occur I've picked up two recent +enforcement actions this is + + align:start position:0% +enforcement actions this is + + + align:start position:0% +enforcement actions this is +airon just to give you a sense of what + + align:start position:0% +airon just to give you a sense of what + + + align:start position:0% +airon just to give you a sense of what +kinds of things they're they're citing + + align:start position:0% +kinds of things they're they're citing + + + align:start position:0% +kinds of things they're they're citing +you for now this was u a white + + align:start position:0% +you for now this was u a white + + + align:start position:0% +you for now this was u a white +finding part 50 appendix B which was + + align:start position:0% +finding part 50 appendix B which was + + + align:start position:0% +finding part 50 appendix B which was +really append quality insurance those + + align:start position:0% +really append quality insurance those + + + align:start position:0% +really append quality insurance those +were quity + + align:start position:0% +were quity + + + align:start position:0% +were quity +program and you didn't and this was in + + align:start position:0% +program and you didn't and this was in + + + align:start position:0% +program and you didn't and this was in +design control failed to take timely + + align:start position:0% +design control failed to take timely + + + align:start position:0% +design control failed to take timely +corrective action after identification + + align:start position:0% +corrective action after identification + + + align:start position:0% +corrective action after identification +of extensive corrosion essential to + + align:start position:0% +of extensive corrosion essential to + + + align:start position:0% +of extensive corrosion essential to +service water Riser and failed to verify + + align:start position:0% +service water Riser and failed to verify + + + align:start position:0% +service water Riser and failed to verify +the adequacy of the methodology and + + align:start position:0% +the adequacy of the methodology and + + + align:start position:0% +the adequacy of the methodology and +design inputs in calculations that + + align:start position:0% +design inputs in calculations that + + + align:start position:0% +design inputs in calculations that +supported the decision to accept three + + align:start position:0% +supported the decision to accept three + + + align:start position:0% +supported the decision to accept three +degraded essential service water pump + + align:start position:0% +degraded essential service water pump + + + align:start position:0% +degraded essential service water pump +GES for sech what does that say to you + + align:start position:0% +GES for sech what does that say to you + + + align:start position:0% +GES for sech what does that say to you +what message was NRC telling excellent + + align:start position:0% +what message was NRC telling excellent + + + align:start position:0% +what message was NRC telling excellent +about what they did from an engineering + + align:start position:0% +about what they did from an engineering + + + align:start position:0% +about what they did from an engineering +perspective + + align:start position:0% +perspective + + + align:start position:0% +perspective +they couldn't get you on a specific + + align:start position:0% +they couldn't get you on a specific + + + align:start position:0% +they couldn't get you on a specific +regulatory non-compliance item + + align:start position:0% +regulatory non-compliance item + + + align:start position:0% +regulatory non-compliance item +right but they got you on your + + align:start position:0% +right but they got you on your + + + align:start position:0% +right but they got you on your +corrective action quality control + + align:start position:0% +corrective action quality control + + + align:start position:0% +corrective action quality control +program which is sort of this catchall + + align:start position:0% +program which is sort of this catchall + + + align:start position:0% +program which is sort of this catchall +appendix B and appendix B says you + + align:start position:0% +appendix B and appendix B says you + + + align:start position:0% +appendix B and appendix B says you +didn't analyze this right and you made a + + align:start position:0% +didn't analyze this right and you made a + + + align:start position:0% +didn't analyze this right and you made a +crappy decision about why you should + + align:start position:0% +crappy decision about why you should + + + align:start position:0% +crappy decision about why you should +continue to operate with degraded + + align:start position:0% +continue to operate with degraded + + + align:start position:0% +continue to operate with degraded +service water + + align:start position:0% +service water + + + align:start position:0% +service water +pipes that's that that's that's a whole + + align:start position:0% +pipes that's that that's that's a whole + + + align:start position:0% +pipes that's that that's that's a whole +different thing where you failed to + + align:start position:0% +different thing where you failed to + + + align:start position:0% +different thing where you failed to +follow the text effects or fail to + + align:start position:0% +follow the text effects or fail to + + + align:start position:0% +follow the text effects or fail to +comply to a regulation you failed to + + align:start position:0% +comply to a regulation you failed to + + + align:start position:0% +comply to a regulation you failed to +follow good + + align:start position:0% +follow good + + + align:start position:0% +follow good +procedures and you made a lousy decision + + align:start position:0% +procedures and you made a lousy decision + + + align:start position:0% +procedures and you made a lousy decision +on how you decided that this this was + + align:start position:0% +on how you decided that this this was + + + align:start position:0% +on how you decided that this this was +still okay to + + align:start position:0% +still okay to + + + align:start position:0% +still okay to +run very significant in my + + align:start position:0% +run very significant in my + + + align:start position:0% +run very significant in my +op the next + + align:start position:0% +op the next + + + align:start position:0% +op the next +one this is a Kami + + align:start position:0% + + + + align:start position:0% + +Peak this is a kamach peak + + align:start position:0% +Peak this is a kamach peak + + + align:start position:0% +Peak this is a kamach peak +now this was an interesting one uh they + + align:start position:0% +now this was an interesting one uh they + + + align:start position:0% +now this was an interesting one uh they +had diesel generators supposed to supply + + align:start position:0% +had diesel generators supposed to supply + + + align:start position:0% +had diesel generators supposed to supply +back of + + align:start position:0% +back of + + + align:start position:0% +back of +power uh they had a white finding Tech + + align:start position:0% +power uh they had a white finding Tech + + + align:start position:0% +power uh they had a white finding Tech +spec violation and it says while the + + align:start position:0% +spec violation and it says while the + + + align:start position:0% +spec violation and it says while the +plan is in most one and two two diesel + + align:start position:0% +plan is in most one and two two diesel + + + align:start position:0% +plan is in most one and two two diesel +generators capable supplying offside + + align:start position:0% +generators capable supplying offside + + + align:start position:0% +generators capable supplying offside +power to one E Equipment which is the + + align:start position:0% +power to one E Equipment which is the + + + align:start position:0% +power to one E Equipment which is the +safety related buses have to be operable + + align:start position:0% +safety related buses have to be operable + + + align:start position:0% +safety related buses have to be operable +now from this perer no one to November + + align:start position:0% +now from this perer no one to November + + + align:start position:0% +now from this perer no one to November +21st while the plant was in operable + + align:start position:0% +21st while the plant was in operable + + + align:start position:0% +21st while the plant was in operable +condition supposed to blah blah blah + + align:start position:0% +condition supposed to blah blah blah + + + align:start position:0% +condition supposed to blah blah blah +power it was inoperable and action was + + align:start position:0% +power it was inoperable and action was + + + align:start position:0% +power it was inoperable and action was +not taken to restore operable status + + align:start position:0% +not taken to restore operable status + + + align:start position:0% +not taken to restore operable status +within 72 hours or be shut + + align:start position:0% +within 72 hours or be shut + + + align:start position:0% +within 72 hours or be shut +there specifically the complaint on the + + align:start position:0% +there specifically the complaint on the + + + align:start position:0% +there specifically the complaint on the +emergency diesel generator was made + + align:start position:0% +emergency diesel generator was made + + + align:start position:0% +emergency diesel generator was made +inoperable as a result of painting + + align:start position:0% +inoperable as a result of painting + + + align:start position:0% +inoperable as a result of painting +activities okay due to the paint having + + align:start position:0% +activities okay due to the paint having + + + align:start position:0% +activities okay due to the paint having +been deposited and remaining on at least + + align:start position:0% +been deposited and remaining on at least + + + align:start position:0% +been deposited and remaining on at least +one fuel rack in location that prevented + + align:start position:0% +one fuel rack in location that prevented + + + align:start position:0% +one fuel rack in location that prevented +motion required to support the operation + + align:start position:0% +motion required to support the operation + + + align:start position:0% +motion required to support the operation +of + + align:start position:0% +of + + + align:start position:0% +of +emergency this caused the the diesel + + align:start position:0% +emergency this caused the the diesel + + + align:start position:0% +emergency this caused the the diesel +generator fa to + + align:start position:0% + + + + align:start position:0% + +start all right so who who's got the bow + + align:start position:0% +start all right so who who's got the bow + + + align:start position:0% +start all right so who who's got the bow +on this one the poor + + align:start position:0% +on this one the poor + + + align:start position:0% +on this one the poor +painter who's watching the + + align:start position:0% +painter who's watching the + + + align:start position:0% +painter who's watching the +store the point of this slidee is that + + align:start position:0% +store the point of this slidee is that + + + align:start position:0% +store the point of this slidee is that +even a tiny thing like painting can get + + align:start position:0% +even a tiny thing like painting can get + + + align:start position:0% +even a tiny thing like painting can get +you in trouble if you're not careful + + align:start position:0% +you in trouble if you're not careful + + + align:start position:0% +you in trouble if you're not careful +about what you're + + align:start position:0% +about what you're + + + align:start position:0% +about what you're +painting okay so those of you who start + + align:start position:0% +painting okay so those of you who start + + + align:start position:0% +painting okay so those of you who start +working in this industry you got to keep + + align:start position:0% +working in this industry you got to keep + + + align:start position:0% +working in this industry you got to keep +these things in mind and the reason I + + align:start position:0% +these things in mind and the reason I + + + align:start position:0% +these things in mind and the reason I +picked these because they're they're + + align:start position:0% +picked these because they're they're + + + align:start position:0% +picked these because they're they're +very different but they can mess you + + align:start position:0% +very different but they can mess you + + + align:start position:0% +very different but they can mess you +up right if this diesel generator fails + + align:start position:0% +up right if this diesel generator fails + + + align:start position:0% +up right if this diesel generator fails +to start it's a problem and the only + + align:start position:0% +to start it's a problem and the only + + + align:start position:0% +to start it's a problem and the only +reason they detected it was it failed to + + align:start position:0% +reason they detected it was it failed to + + + align:start position:0% +reason they detected it was it failed to +start then they started looking it's + + align:start position:0% +start then they started looking it's + + + align:start position:0% +start then they started looking it's +right through the F start oh this thing + + align:start position:0% +right through the F start oh this thing + + + align:start position:0% +right through the F start oh this thing +got stuck because somebody + + align:start position:0% +got stuck because somebody + + + align:start position:0% +got stuck because somebody +painted okay then they look back and say + + align:start position:0% +painted okay then they look back and say + + + align:start position:0% +painted okay then they look back and say +when was the painting + + align:start position:0% +when was the painting + + + align:start position:0% +when was the painting +job one that's how they they pick the + + align:start position:0% +job one that's how they they pick the + + + align:start position:0% +job one that's how they they pick the +time of + + align:start position:0% +time of + + + align:start position:0% +time of +infraction so it's not rocket science + + align:start position:0% +infraction so it's not rocket science + + + align:start position:0% +infraction so it's not rocket science +but very important okay I just want to + + align:start position:0% +but very important okay I just want to + + + align:start position:0% +but very important okay I just want to +stop you know we all talk about this + + align:start position:0% +stop you know we all talk about this + + + align:start position:0% +stop you know we all talk about this +great nuclear performing record 92% + + align:start position:0% +great nuclear performing record 92% + + + align:start position:0% +great nuclear performing record 92% +capacity Factor everything is great the + + align:start position:0% +capacity Factor everything is great the + + + align:start position:0% +capacity Factor everything is great the +industry is booming everybody's making + + align:start position:0% +industry is booming everybody's making + + + align:start position:0% +industry is booming everybody's making +money but as you saw from a little + + align:start position:0% +money but as you saw from a little + + + align:start position:0% +money but as you saw from a little +Litany of key safety issues they've been + + align:start position:0% +Litany of key safety issues they've been + + + align:start position:0% +Litany of key safety issues they've been +around for a very long + + align:start position:0% +around for a very long + + + align:start position:0% +around for a very long +time and when you start to start + + align:start position:0% +time and when you start to start + + + align:start position:0% +time and when you start to start +thinking about the pressure vessel + + align:start position:0% +thinking about the pressure vessel + + + align:start position:0% +thinking about the pressure vessel +integrity and the and the pipe welding + + align:start position:0% +integrity and the and the pipe welding + + + align:start position:0% +integrity and the and the pipe welding +and the primary system integrity + + align:start position:0% +and the primary system integrity + + + align:start position:0% +and the primary system integrity +itself these are going to be coming and + + align:start position:0% +itself these are going to be coming and + + + align:start position:0% +itself these are going to be coming and +continue to come unless people decide to + + align:start position:0% +continue to come unless people decide to + + + align:start position:0% +continue to come unless people decide to +fix fundamental problems and hopefully + + align:start position:0% +fix fundamental problems and hopefully + + + align:start position:0% +fix fundamental problems and hopefully +the new they will but these issues + + align:start position:0% +the new they will but these issues + + + align:start position:0% +the new they will but these issues +Remain the safe operation still requires + + align:start position:0% +Remain the safe operation still requires + + + align:start position:0% +Remain the safe operation still requires +this vigilance that we need attention to + + align:start position:0% +this vigilance that we need attention to + + + align:start position:0% +this vigilance that we need attention to +detail and in my opinion strong NRC + + align:start position:0% +detail and in my opinion strong NRC + + + align:start position:0% +detail and in my opinion strong NRC +oversight because had in my view had not + + align:start position:0% +oversight because had in my view had not + + + align:start position:0% +oversight because had in my view had not +the NRC been as as strong as it was and + + align:start position:0% +the NRC been as as strong as it was and + + + align:start position:0% +the NRC been as as strong as it was and +in some cases people argue it's not + + align:start position:0% +in some cases people argue it's not + + + align:start position:0% +in some cases people argue it's not +strong enough you'll fall into this + + align:start position:0% +strong enough you'll fall into this + + + align:start position:0% +strong enough you'll fall into this +complacency train as our friends at + + align:start position:0% +complacency train as our friends at + + + align:start position:0% +complacency train as our friends at +Exelon did at bra would have tolerated + + align:start position:0% +Exelon did at bra would have tolerated + + + align:start position:0% +Exelon did at bra would have tolerated +Le 3 million + + align:start position:0% +Le 3 million + + + align:start position:0% +Le 3 million +G even think + + align:start position:0% +G even think + + + align:start position:0% +G even think +about the role of the industry and Nei + + align:start position:0% +about the role of the industry and Nei + + + align:start position:0% +about the role of the industry and Nei +every are important because the NRC + + align:start position:0% +every are important because the NRC + + + align:start position:0% +every are important because the NRC +tends will tend to go to one extreme + + align:start position:0% +tends will tend to go to one extreme + + + align:start position:0% +tends will tend to go to one extreme +about uh what the solution ought to be + + align:start position:0% +about uh what the solution ought to be + + + align:start position:0% +about uh what the solution ought to be +and the industry said well let's be more + + align:start position:0% +and the industry said well let's be more + + + align:start position:0% +and the industry said well let's be more +reasonable and with the onset of + + align:start position:0% +reasonable and with the onset of + + + align:start position:0% +reasonable and with the onset of +probabilistic risk assessment risk + + align:start position:0% +probabilistic risk assessment risk + + + align:start position:0% +probabilistic risk assessment risk +inform performance-based + + align:start position:0% +inform performance-based + + + align:start position:0% +inform performance-based +uh safety determinations we have a shot + + align:start position:0% +uh safety determinations we have a shot + + + align:start position:0% +uh safety determinations we have a shot +at sort of maintaining that is this + + align:start position:0% +at sort of maintaining that is this + + + align:start position:0% +at sort of maintaining that is this +safety significant or not kind + + align:start position:0% +safety significant or not kind + + + align:start position:0% +safety significant or not kind +discussion + + align:start position:0% +discussion + + + align:start position:0% +discussion +so this is the one that that makes me a + + align:start position:0% +so this is the one that that makes me a + + + align:start position:0% +so this is the one that that makes me a +little nervous we're all bragging about + + align:start position:0% +little nervous we're all bragging about + + + align:start position:0% +little nervous we're all bragging about +the high capacity factors and yet when + + align:start position:0% +the high capacity factors and yet when + + + align:start position:0% +the high capacity factors and yet when +you think about the things that we just + + align:start position:0% +you think about the things that we just + + + align:start position:0% +you think about the things that we just +went through we're not done really in + + align:start position:0% +went through we're not done really in + + + align:start position:0% +went through we're not done really in +assuring the safety of these PL so any + + align:start position:0% +assuring the safety of these PL so any + + + align:start position:0% +assuring the safety of these PL so any +reactions or + + align:start position:0% + + + + align:start position:0% + +comments + + align:start position:0% +comments + + + align:start position:0% +comments +no okay now next week's our last class + + align:start position:0% +no okay now next week's our last class + + + align:start position:0% +no okay now next week's our last class +uh scheduled is I'll do a quick review + + align:start position:0% +uh scheduled is I'll do a quick review + + + align:start position:0% +uh scheduled is I'll do a quick review +of the uh material that we + + align:start position:0% +of the uh material that we + + + align:start position:0% +of the uh material that we +covered during this term and also um + + align:start position:0% +covered during this term and also um + + + align:start position:0% +covered during this term and also um +provide some insights as to the advanced + + align:start position:0% +provide some insights as to the advanced + + + align:start position:0% +provide some insights as to the advanced +reactors that we're talking about uh + + align:start position:0% +reactors that we're talking about uh + + + align:start position:0% +reactors that we're talking about uh +please uh hand in the homework + + align:start position:0% +please uh hand in the homework + + + align:start position:0% +please uh hand in the homework +assignments so I can get them done and + + align:start position:0% +assignments so I can get them done and + + + align:start position:0% +assignments so I can get them done and +grade submitted um I think there are two + + align:start position:0% +grade submitted um I think there are two + + + align:start position:0% +grade submitted um I think there are two +two missing sets right now there's no + + align:start position:0% +two missing sets right now there's no + + + align:start position:0% +two missing sets right now there's no +homework for this class and there won't + + align:start position:0% +homework for this class and there won't + + + align:start position:0% +homework for this class and there won't +be any homework uh for the F class but I + + align:start position:0% +be any homework uh for the F class but I + + + align:start position:0% +be any homework uh for the F class but I +want you to spend the time to do + + align:start position:0% +want you to spend the time to do + + + align:start position:0% +want you to spend the time to do +that okay questions comments + + align:start position:0% + + + + align:start position:0% + +suggestions good all right thank you \ No newline at end of file diff --git a/9CPA6WG6mRo.txt b/9CPA6WG6mRo.txt new file mode 100644 index 0000000000000000000000000000000000000000..17e3be292786d880385c06173002c222a8482412 --- /dev/null +++ b/9CPA6WG6mRo.txt @@ -0,0 +1,2950 @@ +The following content is +provided under a Creative + +Commons license. + +Your support will help +MIT OpenCourseWare + +continue to offer high quality +educational resources for free. + +To make a donation or to +view additional materials + +from hundreds of MIT courses, +visit MIT OpenCourseWare + +at ocw.mit.edu. + +PROFESSOR: Well let's see +if we can't get started. + +Everyone I trust can +hear me adequately. + +Welcome back. + +It's Tuesday. + +For those of you who are not +in my recitation section, + +I'm Dave Gossard, and I'll +be your lecturer for the day. + +Professor Vandiver +is out of town. + +It looks like some of +you may be as well. + +We probably could have held this +at the gate at Logan Airport + +and done a little better. + +But be that as it +may, glad you came. + +This should be fun. + +Today we have a new topic +and a demonstration, + +a real physical system. + +So unless there are any +outstanding questions? + +Anybody have any +questions or complaints + +to address to Vicente? + +No. + +All right, hearing none let's +go ahead and get started then. + +Today the topic is multiple +degree of freedom systems. + +Now to date, with a +couple of exceptions, + +all of the systems +that you've dealt with + +had a single degree of freedom, +either a linear displacement + +x or an angular +displacement theta. + +You know the concept +of equations of motion, + +or I should say the +equation of motion + +and the notion of undamped +natural frequency. + +Well, today we're going to +generalize, if you will, + +to systems that have not one +but multiple degrees of freedom + +and see how those +notions generalize. + +In particular, as +you might expect, + +the system that has +multiple degrees of freedom + +has multiple natural +frequencies, also + +known as eigenvalues as we +will explain here shortly. + +Multiple degrees +of freedom systems + +have a new property, +a new characteristic + +you haven't seen before. + +And that's what this +lecture is all about, + +is to illustrate that to +you and demonstrate it. + +It's the notion +of natural modes, + +also called eigenvectors. + +And then the general response +to initial conditions. + +So that is the plan for the day. + +And we'll start with this. + +This is kind of a +classic textbook + +case, two springs, two masses. + +A straightforward extrapolation +of what you've done before. + +You've got a spring K1, +mass M1, spring K2, mass M2. + +And the displacements +are indicated + +as shown there, X1 and X2. + +I want to hasten to point out +that the displacements we speak + +of here are defined with respect +to the static equilibrium + +position. + +This is a notion that Professor +Vandiver went over at least + +once. + +And for those of you who've +forgotten it or weren't there + +that day, I have for you a +reference, essentially reprised + +that notion over there. + +So in the meantime, +let me press on. + +If you have any questions, we +can go back and cover that. + +But assuming you agree, let +me simply say you've got + +two springs, two masses. + +The typical way we've +taught you to do + +it is if you're +going to generate + +the equations of motion +by the direct method, + +you generate two free +body diagrams, the sum + +forces in the x direction +for each of the masses, + +get f equals MA and +you'd get these. + +Conversely, you could +also do it by Legrange. + +You could generate +the expression + +for the kinetic energy, +for the potential energy, + +for the Legrangian, do this +Lagrange equation business, + +and you'd get the same thing. + +But either way you do it, +what comes out the other side + +looks like this. + +And it's not a bad exercise +for you to offline convince + +yourself that this is right. + +Not right now, but in +the comfort and leisure + +of another time. + +So there you have it. + +That's what the two equations +of motion would look like. + +Again, either by the direct +method or by Legrange, + +you end up in the same +place, so to speak. + +And now for today, we haven't +asked you to do this much, + +but let me simply say +the weapon of choice + +for multiple degrees +of freedom system, + +because there's a certain +repetitive quality to it, + +matrix notation is preferred. + +In these equations over +here, written in matrix form + +would look like this. + +And that looks like this. + +There's two matrices, +and let me hasten + +to point out that this is +exactly this and nothing more. + +There's no magic, no +additional derivation. + +This is simply a restructuring, +and reorganization + +of these equations. + +And this may seem +foreign to those + +of you who have not had any +or very much linear algebra. + +Do not be dismayed. + +It is not a difficult +thing to learn. + +As you probably know, a matrix +multiplies by a vector-- + +or multiplying a +vector by a matrix-- + +is done with two hands. + +The first item for example +is M1 X1 dot plus 0. + +That gives you this +term right here. + +Over here you get +X1 times K1 plus K2. + +That's this one. + +And here you have minus +K2 X2, that's that term. + +So matrix notation, +this becomes that. + +No problem. + +It's like a model train set. + +It's great. + +Everyone should +have one of these. + +All right, so what I would +like to do for our example here + +is because we're going +to be doing some algebra, + +for the express purpose of +simplifying the algebra let + +me consider a special case +where the masses are identical. + +And we can simply call +them M. And similarly, + +the springs are identical, +and we'll simply call them K. + +At that point, these +equations become simplified. + +That's just M, that's +just M. So this + +is the problem we're +going to-- we're + +going to tackle this problem +first, because as I say, + +it simplifies the algebra. + +Now here is-- this +is not an assumption. + +This is a-- I would call +this more a mechanism + +to get this job done here. + +Harmonic motion is +one where we assume + +that the masses oscillate +at the same frequency. + +So what this looks like is this. + +What we're basically saying +is that X1 is actually + +equal-- X1 has +amplitude A-- whoa. + +I'm being attacked here +by the second board. + +Basically, the situation +here is that we're + +assuming that both +of these masses + +move-- I wouldn't call +it exactly together. + +They're not in +complete synchrony, + +as you'll see here in a moment. + +But what they are +is they're going + +through a sinusoidal motion. + +And it is an oscillation +at the same frequency. + +Both of them are oscillating +at the same frequency. + +However, they differ +in their magnitudes. + +They are not the same magnitude. + +But that assumption right +there allows us to say this. + +If we differentiate those +twice, we get the following. + +That comes back out. + +Douglas, where's +that minus sign come? + +Can you-- first of all, +can everybody read that? + +Can you guys read that +in the back row here? + +For example, this says that X1 +double dot, if x1 is A1 cosine, + +then X1 double dot +is A1 cosine preceded + +by a minus omega squared. + +Where does that come from? + +AUDIENCE: The minus sign came +from when you differentiated + +the cosine in the first one. + +PROFESSOR: Exactly. + +And the cosine returns. + +And that's what you get. + +Well, here is, shall we say, +the heart of the matter. + +When you substitute +this into this-- + +let me call this-- I'll try not +to get too obsessive over this. + +But these are our +equations of motion. + +So when we-- you +get this, equals 0. + +Excuse me. + +Many people, I think, +simply put a big 0 there, + +but I'll do it properly. + +It's two zeros, if you will. + +And forgive me for +writing this out, + +but I would like you +to be able to do this + +by yourself, to recreate +this after the fact. + +This becomes-- dividing +and collecting terms. + +OK, anybody unclear about +how this is obtained? + +Yes, ma'am. + +Emma. + +AUDIENCE: I have a question +about the previous one. + +PROFESSOR: Yeah? + +AUDIENCE: If the second +term on the left hand side, + +should it also be +multiplied by A1 A2? + +PROFESSOR: Yes it should. + +Thank you very much. + +Oh, hang on. + +Yes, thank you, +that's exactly right. + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: Hang on a second. + +We're fighting the boards here. + +Let's see, one thing at a time. + +We've got A1, A2 cosine +[INAUDIBLE] minus phi equals. + +Now Emma, does that +take care of you? + +Yeah? + +And you said, Vicente? + +AUDIENCE: Diagonal terms-- +shouldn't there be a minus? + +PROFESSOR: I'm sorry, +that's absolutely correct. + +Wonderful. + +So there we have it. + +Any other questions? + +I hope I got it right. + +Yes sir. + +AUDIENCE: Are they plus K? + +PROFESSOR: I'm sorry? + +AUDIENCE: Are they plus K? + +PROFESSOR: Plus K? + +No. + +They're minus. + +Yeah, why is that? + +Everybody see that? + +This is a straight-- there's +less here than meets the eye. + +There's a straight segregation +collecting of terms. + +The minus got added to the +elements of the mass matrix, + +but not to the K metrics. + +The K metrics goes +shows through as is. + +Now, the question on the +floor is what we do with this? + +Can everybody appreciate +that-- get out + +of the spring mass +business and look at this + +from a math point of view? + +Does everyone +appreciate that this + +is a set of linear equations? + +There's the old AX +equal B kind of thing. + +And if you recall, to solve, +what we're basically going + +to do is solve for A1 and A2. + +That's the game +we're playing here. + +And if you recall from your math +course, the determinant of this + +has got to equal 0. + +So let me simply repeat it here. + +The determinant of +has got to equal 0. + +And you recall, the determinant +is for at least the two + +by two you can do it +by hand more or less. + +It's the cross products +with appropriate sign. + +And I'm sparing you +some algebra here, + +but trust me when you do +this, this is what you get. + +M squared omega 4 minus +3KM omega squared, plus K2. + +That's it right here. + +This little guy-- oh, all right. + +I can't do that anymore. + +I know, it's this one. + +That is called the +characteristic equation. + +So here's the first answer. + +AUDIENCE: [INAUDIBLE] +should that be K squared? + +PROFESSOR: I'm sorry. + +That's a typo. + +That's simply K. + +AUDIENCE: [INAUDIBLE] K squared? + +PROFESSOR: Or it's +K squared, rather. + +Sorry. + +Thank you. + +AUDIENCE: I think +in the above line, + +the determinant-- the upper +left-- should had a 2K. + +PROFESSOR: Oh, this +is 2K, absolutely. + +All right, 2K. + +Good enough? + +All right, thank you. + +So let's send this to the top. + +So the roots of +the characteristic + +are the natural frequencies. + +Let's do this this way. + +Did I do that right? + +Yeah, plus or minus. + +So the situation is that when +you apply the quadratic formula + +to that characteristic equation +to find the values of omega + +for which that +equation is satisfied, + +those omegas that come out +are the natural frequencies. + +They are the quantities we seek. + +And what that yields, as you +can see from the plus or minus + +here, there are two of them. + +I'll write the whole +thing out here. + +And these are numerically. + +OK, everybody see that? + +So here are our two +natural frequencies. + +Here's the first one-- excuse +me, that's not right either. + +That's the square. + +OK So these are our natural +frequencies, once again + +for this special case +where the masses are equal + +and the springs are equal. + +Anybody recognize +that number, 0.618, + +for all you fuss budgets? + +Ring any bells? + +Any number freaks here? + +No? + +I heard it. + +That's it. + +Exactly, nice job. + +The golden mean, +the golden ratio. + +Also, let me simply +say if there are-- + +as far as the number +of things-- if there + +are n degrees of freedom. + +There are n natural frequencies. + +What else? + +So that's that. + +So now it's time to get to this +notion of the natural modes. + +Let me say, we've got +to go all the way back + +to this set over here. + +If you take the first row +of this matrix equation-- + +that's the first of the +equations of motion-- + +and you make that assumption of +the harmonic motion in there. + +Does everybody see that? + +What we've done is we've +taken basically the first row + +of that expression +right up there + +and formed the amplitude +ratio A1 over A2. + +What we're doing is +we've found the omegas. + +You remember, just +review the bidding. + +Our original +assumption was harmonic + +motion, that is to say +all the displacements are + +moving in synchrony as it were. + +The same sinusoidal +frequency, we've + +just found what +frequencies those are. + +There are two of them, +and they're right there. + +Now we're after these guys. + +Now we're after the +relative magnitudes + +or the relative +amplitudes of A1 and A2. + +And we from one of the +equations isolated one of those. + +And let me just say, if +you plug these back in, + +plug in the first one, you'll +get oddly enough 1.618, + +These amplitude ratios. + +Are the so-called natural modes. + +And I think you can appreciate +that this is the first one, + +and this is the second one. + +Any questions so far? + +Wonderful. + +Hearing none. + +Yes ma'am, Sara? + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: You see +this amplitude ratio. + +You saw how we got that. + +You see that the right hand side +has got system parameter, Ks + +and Ms, and stuff like that. + +But this is the ringer, omega. + +This amplitude ratio +is expressed in part + +in terms of omega. + +So what omega-- there's no +ambiguity as to Ks and Ms, + +but what omega? + +Well the answer is, when +we plug in this one, + +you get this answer. + +When you plug-in this +one, you get this answer. + +So while we're at it-- Sara, +want to hazard a guess? + +How many natural mode +do you think we've got? + +Yeah, exactly. + +So you're going to +have one of these + +for each degree of freedom. + +Let me just point out a +couple of elements here, + +and then I'll show you a +demonstration because we + +have to have some fun today. + +These are point of informations. + +They're ratios, not +absolute magnitudes. + +That's number one. + +The second is-- I already told +you, they got the same number. + +OK, each natural +mode is associated + +with a particular +natural frequency. + +This one goes with that one. + +And once again, they're +associated with-- yeah, + +let me say that. + +I need another board. + +Let's just go over here. + +So in a sense-- +this is decouple. + +Decouple essentially into +independent subsystems. + +So in general, what the system's +response looks like is-- + +I'm talking about the +one in front of us here. + +This special case, where the +masses and springs are equal. + +I think there's a +minus sign in here. + +Does this come up? + +Wonderful. + +That's it. + +Does everybody see that? + +Yes, sir. + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: I'm sorry? + +AUDIENCE: What does it say +under that first bullet point? + +PROFESSOR: Here? + +AUDIENCE: These +describe the situation. + +PROFESSOR: These +describe the situation + +in which the entire +system is oscillating at. + +It's the second bullet here. + +Thank you. + +AUDIENCE: At what? + +PROFESSOR: At one frequency. + +Sorry, I'm just getting a +little tired of writing. + +So, any other questions, +problems, complaints? + +All right. + +AUDIENCE: I have a question. + +PROFESSOR: Yes, sir. + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: That's correct. + +Then, let's see. + +Then there's a +mistake right here. + +Thank you. + +Yeah, because that's +the way it came out. + +When you plug omega 2 +having this value into here, + +the amplitude ratio +comes out minus. + +Fair enough? + +It threw me there for a minute. + +I thought you were going to say, +why is the minus sign is there, + +rather than you could have +had minus 1.618 and plus 1. + +And the answer is no reason, +because these are ratios. + +Yeah, Kaitlin? + +AUDIENCE: But shouldn't-- when +we go back and look at what you + +wrote down, it's [INAUDIBLE]. + +I don't understand +how that [INAUDIBLE]. + +PROFESSOR: I'm sorry, say again? + +AUDIENCE: Never mind. + +PROFESSOR: Find it? + +Yeah, they're ratios, It's +just as simple as that. + +So you multiply them by any +number and it still works. + +I'll actually show +you here in a second. + +At least, I believe +that's the case. + +We'll just see here in a second. + +OK, questions? + +Comments? + +All right. + +Now is the time. + +Could I bring up +the side board here? + +Let me show you-- +anybody here taken 2086? + +Wonderful. + +I've got one person? + +Great. + +Anyway, I believe in 2086, +don't they teach you MATLAB? + +Isn't that the weapon of choice? + +OK, that's the program +I'm using here, MATLAB. + +For those of you who +haven't seen it yet, + +it is definitely a mixed bag. + +I don't know how +you feel about it. + +It's very-- yeah-- +it's very powerful. + +It stands for Matrix Laboratory. + +It was written, I don't +know, 20, 30 years ago here, + +I believe, at MIT by people who +were into matrices, into matrix + +algebra. + +And it's kind of +command line oriented. + +The good news, +it's very powerful. + +Whatever you want to do, +you can do in MATLAB. + +The bad news is, the +user interface stinks. + +The language is very +difficult to learn. + +It's even harder to remember. + +So with that +rousing endorsement, + +let me show you +what we've got here. + +This is a program I've-- is +that font readable by you guys? + +No? + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: I'm sorry? + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: Yes. + +Well, I believe I can-- +here we go, fonts. + +Upping the fonts is +kind of a mixed bag, + +because you get bigger +letters but they're. + +OK, how's that? + +So here's the situation. + +This is a MATLAB program. + +And I'll explain to you +what it does as we go. + +Let me see if my little +cursor-- my cursor's here, + +but I can't see it. + +All right, here's the +system parameters. + +Once again, we're doing +a simple spring mass-- + +this simplified spring mass +system, exactly the one + +we've done here. + +When I wrote it, you'll see I +generalized it to do this guy. + +So we got M1 and M2, K1 and K2. + +But if you'll notice, you see +here their values are equal. + +We've got the mass +at one kilogram each. + +And we've got 10 newtons per +meter on each of the springs. + +Everybody appreciate that +this system's numbers + +that we're putting in here +match our case here, K over M? + +OK. + +And you can see +here, we've defined-- + +and again, let me +just say I'm not + +trying to sell you on MATLAB. + +I don't want to leave +you with the impression + +that we expect you to be +able to instantly become + +a user of MATLAB. + +This is simply to illustrate +the point of the lecture here. + +Here is the M, +the system matrix. + +There's the K matrix. + +And I'll show you the eigenvalue +and eigenvector thing later. + +But let me-- take +my word for it. + +See this here? + +Ode45 is a cryptic allusion +to the Runge-Kutta algorithm, + +fourth order Runge-Kutta that +is the workhorse for integrating + +differential equations. + +And so let me just run this. + +And what I've got here +is, here's the point + +I wanted you to get +here, because I'll + +bet you can't see +that cursor either. + +Yes, anyway, see +this right here? + +tspan is the time scale and +the time step, defined up here. + +But these are basically +the initial conditions. + +See it here? + +X1, X1 dot, X2, X2 dot. + +So here's the first one. + +This is a 0.618 is for the X1. + +And 1 is for X2. + +Everybody appreciate that? + +Got it? + +OK. + +If these are the initial +conditions, what I've done, + +I have artfully chosen +the initial conditions + +to have the same ratio. + +What do you expect +is going to happen? + +When I turn this thing-- +I've got a simulation here. + +I'm going to run this, +and you're actually + +going to see it. + +What do you think +you're going to see? + +It's a two spring, +two mass system. + +What I've done is I've +displaced the two masses. + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: They'll certainly +have an amplitude, because I'm + +putting it in there. + +That's the initial condition. + +The question is, what frequency +you think they'll oscillate at? + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: Pardon? + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: Each of +them will oscillate + +with the same frequency, +for sure, but what + +do you think it's going to be? + +AUDIENCE: That one. + +PROFESSOR: It's +going to be that one. + +So off we go. + +So let us hope that yours +truly's program worked. + +Here we go. + +Oh, look at that. + +[INAUDIBLE], please +interpret that for me. + +What do you see there? + +Hang on a second. + +Let me blow it up +so you can see it. + +Ooh, isn't that pretty? + +And I believe the blue is +X1 and the green is X2. + +See? + +Everybody agree? + +Everyone appreciate +what's going on? + +You pull them both at +slightly different-- + +you basically used +the first natural mode + +as the initial condition. + +And sure enough, they +oscillate together. + +They oscillate at +the same frequency. + +They oscillate at +that frequency. + +Let me just see-- +I just want to make + +sure we get the full +value out of this thing. + +Well, of course you +can't see it anymore + +because our numbers are so big. + +Well, that's great. + +Anyway, take my word for +it at-- oh, here it is. + +The period for the first +natural frequency-- or I + +guess it's the second-- +it should be like 1.2. + +Or is it 3? + +Yeah, I'm sorry, +the period is 3.2. + +And sure enough, there it is. + +It's about 3. + +3.2. + +Fabulous. + +Everybody got it? + +OK, now watch closely. + +Let me see if I can do this. + +This requires a little +dexterity, which + +is always a short supply here. + +I have to hit this and this. + +Make sense? + +That's what it +actually looks like. + +They're both oscillating at +the same natural frequency, + +going up and down together. + +But they have +different amplitudes. + +So one's bigger than the other. + +So that's what it looks like. + +Questions? + +Christina, you good? + +Clear enough? + +Wonderful. + +So let's go to our program. + +And instead of that set +of initial conditions, + +we'll do the other. + +Read them to us here. + +What are the initial +conditions here? + +AUDIENCE: It's 1.618. + +PROFESSOR: That's +right, it's this guy. + +AUDIENCE: That guy. + +PROFESSOR: It's this guy. + +It's this ratio. + +So I basically +arbitrarily chose, is it + +the negative first? + +No. + +I chose that one +over there, 1.618. + +And then a minus 1 +for the second one. + +Fair enough? + +OK, there it goes. + +We've got to save it +and make sure we got it. + +So again, you got a clue +what's going to happen here? + +Here we go. + +Boom. + +Look at that. + +What's going on there? + +Yikes. + +Explain me. + +Is that good, bad, indifferent? + +Is it right? + +Wrong? + +AUDIENCE: The way +the system acts, + +it has a higher frequency. + +PROFESSOR: Yeah, exactly. + +Two things. + +One is, they're out of phase. + +They're doing this. + +One's going this +way, and the other's + +going the other at +different amplitudes + +but the same frequency. + +But the frequency in question +is higher than the previous. + +AUDIENCE: Why are +they out of phase? + +PROFESSOR: I'm sorry? + +AUDIENCE: Why are they +opposite of each other? + +PROFESSOR: [INAUDIBLE], why +are they opposite each other? + +Because we made them that way. + +We said, that's the +initial condition. + +Does that make sense? + +That minus sign does. + +One starts out, +and one starts in. + +And they do that. + +Clear enough? + +Now what's going to happen +if we plain just choose + +any old initial condition? + +These were special. + +We worked like a dog +to compute these, + +so that the system would +decouple in that way. + +So what if we-- now +let me put that back. + +Now look at this one. + +All right, look at that. + +Read that to me. + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: Yeah. + +So that says the initial +condition for the first mass + +is 1 and whatever that is. + +One whatever that is. + +The second masses' +initial condition is half + +that in the same direction. + +Both positive. + +So Christina, they're +going to go together. + +But [INAUDIBLE], +at what frequency? + +Any idea what it's +going to look like? + +If you do, you're a +better man than I, + +because what you're going +to see here is that. + +It's this thing right here. + +It's that expression +right there. + +And here's what it looks like. + +Did I stop the-- +oh, wait a minute. + +Did I ever show you that before? + +I think I forgot to +show you the other. + +Anyway, not to worry. + +Hang on a second. + +I've got to stop this guy. + +First I have to find my finger. + +There it goes. + +That's the previous case. + +When they're out of phase, +different magnitudes, + +going in opposite directions. + +And you can see, they're +going at a higher frequency + +than before. + +Make sense? + +So now we are-- just to +refresh your memory-- + +now we're going for the +third case, in which there's + +nothing special. + +We just picked a couple +of initial conditions + +out of a hat. + +And here we go. + +Oops, I think not. + +I think that's +the previous case. + +So let's go here. + +This is another wonderful +thing about MATLAB + +is nothing happens +until you save it. + +So we were just running +the previous case. + +Nasty. + +Look at this. + +All right, can +everybody see that? + +If you can interpret this, +you're smarter than I am. + +But what this is, this is simply +this expression over here. + +It's this expression +for just some arbitrary + +initial condition. + +Do you see that that +behavior though? + +Each of them, they're +going together kind of, + +but they-- anyway, watch this. + +Here's what the simulation +of that looks like. + +What the heck is that? + +Well anyway, the +point of the story + +is that multiple +degrees of freedom + +system in general's response +can be arbitrarily complicated. + +It's not arbitrarily +complicated, + +but pretty complicated. + +You'll get, in general if it's +an nth order system, if you + +don't know anything +about the worst case, + +you'll see four +frequencies in there. + +And they're all mixed together +in some mystical way that's + +unknown to you. + +Fair enough? + +And it's only when you reach the +natural modes that you actually + +find out what is going on here. + +Well now I have to turn +your attention to this guy. + +This is made by Professor +Vandiver's machinist, + +a perfect example of +a second order system. + +And I bring it to +your attention here + +for two-- at the end of the +day what we're going to do + +is I'm going to demonstrate +exactly what I just + +did for the textbook +case, the textbook system. + +I want to demonstrate exactly +the same thing for this guy, + +only this is a real system. + +Very nice. + +We have a steel rod. + +It must be a half +inch in diameter. + +The whole thing +weighs several pounds. + +These sliding masses are right +circular cylinders with a hole + +drilled through them. + +It's ever so slightly +larger than these here. + +They're of different lengths. + +They're made of brass. + +They're serious masses. + +And the springs, +which extend from here + +to here, and from here to +here are wound on a lathe, + +and attached, and so forth. + +Pretty, no? + +Now look right off the bat. + +Did you see how +that thing operates? + +Would you agree you have some +complicated behavior here? + +Now also would you agree +that this is it like that? + +Everybody see that? + +Before we go too far, this +is a mixed message here. + +[INAUDIBLE], is this +exactly like that? + +In what way is it +similar to that? + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: Well, what is clear +is that you've got two springs + +and you've got two masses. + +About that there is +very little argument. + +AUDIENCE: It's damped. + +PROFESSOR: It's damped. + +Can everybody see that? + +How does [INAUDIBLE] +know that it's damped? + +How's he know it's damped? + +I mean, that's just a wild +guess on his part, but. + +AUDIENCE: You can hear +it, and it slows down. + +And it slows down. + +This is the most important +part is that it stops. + +Eventually if you come back +in a minute or two, it's done. + +PROFESSOR: All +right, [INAUDIBLE]. + +You're on a roll. + +There's definitely +damping there. + +What kind of damping? + +AUDIENCE: Friction. + +PROFESSOR: Friction, yeah. + +Does that have another +name that you can think of? + +It's definitely friction. + +What it's not is +viscous friction. + +What it is not is a damper or +a dashpot which we've shown you + +before with the ideal expression +that generate a force that + +opposes the-- generation of an +opposing force that's linearly + +proportional to the velocity. + +What's going on +here, do you think? + +What kind of damping +do you think? + +It's called Coulomb. + +This is called Coulomb damping. + +And this is a digression. + +Now we're on the part where this +is really-- everything that's + +on the board is what I +wanted you to really come + +away from today with. + +So now we're out +kind of in the, I + +would call it the +winging it area + +right here, because this +is the part where I simply + +had fun with the demo. + +This is viscous. + +And this has got the +symbol-- well anyway, + +this is what it looks like. + +And this is the +force of the damper. + +We'll call it B. + +And this is the velocity. + +And this is for constant +of proportionality B. + +And it has this little +symbol, like that. + +And when equations of motion +are solved that contain that, + +the response looks like this. + +What we're talking about +here, the force put out + +is a constant. + +That just comes +from the sliding. + +And what it generates are +distinctly non-linear equations + +of motion. + +And what you get here is you +get this kind of behavior. + +If you really looked +at it, what you'll see + +is there's definitely +damping for large motions + +when the inertial forces and +so forth are large compared + +to the friction forces. + +It'll look a lot like +conventional viscous damping. + +It's just that when +motions get really small, + +and the forces get down there +to on the order of this, + +all a sudden you'll see on +one cycle it'll just stop. + +And were you up here +where you could see, + +or if we had a closeup of this-- +you can't see it, but just + +watch this thing stop. + +Right there. + +Do you see that? + +That's a little hard for you +to see from there, but watch. + +Anyway, were you up +here, you'd see this. + +That's what we're looking at. + +Well here we go. + +I need some help here. + +Who's in a volunteering +frame of mind? + +Amy, all right. + +I appreciate the help here. + +Here's what I want to do. + +We just blew out some +wonderful theory. + +All this is just +solid as a rock. + +Yes, sir. + +AUDIENCE: For the Coulomb +friction, is that a linear + +[INAUDIBLE]? + +Or is it still exponential? + +PROFESSOR: I'm sorry? + +Oh, no. + +If I'm not mistaken, I +didn't really look this up, + +but I believe it's linear. + +I'd have to-- take that +with a grain of salt, + +but I believe it's linear. + +Yes, Amy, here's the situation. + +We have all this +marvelous theory. + +My goal is to-- and we have this +fabulous demo apparatus, though + +inherited. + +And what I'd like to do-- oh, +and we have computational means + +to. + +And in fact, we just went +through the exercise. + +We already know those +same equations that + +work for this work for this. + +Those are general. + +However, it's not my +piece of apparatus. + +And well, here's the deal, +what are the Ms and Ks. + +What are the values of-- I need +M1, K1, M2, K2 to put into the. + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: Yeah, Yeah. + +That's what I'd like +to do is I'd like to. + +AUDIENCE: Do I have +to just determine + +the it by looking at it? + +PROFESSOR: Oh no, no, no. + +No, no. + +AUDIENCE: I'm not that good. + +PROFESSOR: You're my assistant. + +I guess the question +is, how would + +you-- and I've got +to tell you, that's + +the math part of a program. + +Now we're in the engineering +part of the program, + +because somebody gave you +a real live demo apparatus. + +Works like crazy, or appears to. + +And I'd love to take +advantage of it, + +but I don't know +any of the numbers. + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: No. + +That's the constraint +I'm operating on. + +It doesn't belong to me. + +I mean, I could take it apart. + +That's an absolutely +appropriate thing to do. + +I would have liked to. + +It would be easier if you could. + +You just go, take a +screwdriver to it. + +Here, put this on there +and pull this out. + +I didn't have the luxury +of any of that, so what's + +your next best suggestion? + +Nice suggestion, but no cigar. + +I'm sorry? + +AUDIENCE: Take it apart +anyway, put it back together + +before the person notices. + +PROFESSOR: Well yeah. + +Yeah, no. + +That's fudging. + +Yeah, they notice. + +Have you ever taken +apart anything made + +in modern manufacturing method? + +Oh, it's good because you +can't put them back together. + +They're assembled by machine. + +And once upon a time you +could disassemble one + +and reassemble things +without detection. + +But anymore, once +you take them apart, + +it's wicked hard to +get them back together. + +OK, the floor is open. + +I need another suggestion. + +What are you going to do? + +AUDIENCE: Do you need to +know the exact K and M, + +or do you just +[INAUDIBLE] another ratio? + +PROFESSOR: I thought +you were going + +to-- I need to know M or +K. I need to know them all. + +AUDIENCE: Do you know +the density of the-- + +PROFESSOR: I was going +to say, but I don't + +need to know anything exactly. + +All I need to know is as good a +guess as you can come up with. + +It's all an estimate. + +AUDIENCE: If you know the +density of the material, + +you can easily work +up [INAUDIBLE]. + +I'm assuming you're +about [INAUDIBLE]. + +PROFESSOR: Oh +absolutely, absolutely. + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: Wonderful. + +Absolutely. + +She hit the jackpot, +rang the magic buzzer. + +That's exactly what I did. + +Here's a little crummy sketch. + +Oh wait, you can't see that. + +Anyway, these are right circular +cylinders with holes in them. + +And they've got +measurements beside them. + +I can tell you, this +is 75 millimeters. + +This is 35 millimeters. + +This one is 37 millimeters long. + +So I did that. + +That's great. + +That's an excellent suggestion. + +And after I did exactly that, +I won't write out the formula. + +You know area, and +volume, and all of that. + +Let me get you the +right order here. + +M1 is 0.2929, and M2 is 0.5938. + +Everybody got that? + +This was obtained by taking +a ruler to these things, + +taking diameters, lengths, +and diameters of holes, + +multiply them times the density +of brass taken out of the book. + +Do you believe that? + +Do you believe that number? + +Well, you're a trusting soul. + +I don't. + +To me, I believe that number. + +This was done with a ruler. + +The little millimeter thingies. + +So I just say, don't fall in +the trap of false precision. + +OK Amy, you're on a roll. + +We've got the masses. + +What now? + +AUDIENCE: Free body diagram. + +PROFESSOR: Yeah, +we got all that. + +AUDIENCE: Yeah, you've got that. + +But then what you can +do for the spring, + +the forces of the +spring when static. + +Don't move it. + +So take the top mast. + +It's not moving, +which means that you + +know that the force going +upwards-- which is the spring-- + +is equal to the force going +downward, which is [INAUDIBLE]. + +So you can measure +the displacement + +from the start of the spring +to the bottom of the spring. + +Do you know the natural +length of the spring? + +PROFESSOR: No Anyway, +what I was going to say + +is, excellent idea. + +Can't do it. + +But what Amy was +basically saying is, + +you know the masses now. + +Why not simply take +from that expression + +right there, MH over K, right? + +What's the problem with that? + +How about it? + +Devin, how come I can't do that? + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: Yeah, I really don't +know the no load position. + +Is that it, Amy? + +Right there? + +Maybe. + +Devin, you're the one +that suggested it. + +Are those the no load +positions of the masses? + +And if not, why not? + +I did mean to give +you a clue there. + +Yeah, Nick? + +AUDIENCE: It can't be because +there's static friction. + +PROFESSOR: Exactly. + +So Nick, you brought it up. + +What's that number? + +You don't know that either. + +No. + +Like I said, Amy, nice idea. + +No cigar. + +What else? + +We're running out of time? + +Here we go, Douglas. + +AUDIENCE: Could you +displace each mast a certain + +[INAUDIBLE], and +then measure the time + +it takes for them to stop +and get the damping ratio? + +PROFESSOR: Hit +the damping ratio. + +Well, I'll tell you what-- +you want to say that again? + +He said displace one or +both count oscillations + +and get the damping ratio. + +Nick? + +AUDIENCE: Do we have anything +like a force gauge or a spring + +scale? + +PROFESSOR: No. + +This is my living room +I'm talking-- or my study. + +Anyway, Douglas said-- I +forgot what you said now. + +He said-- oh, I know. + +You said, displace it and +count the oscillations. + +Get the damping ratio. + +First off, the damping ratio is +no help, even if we did get it. + +And the only formula for +which we've ever given you-- + +the only formula +we've ever given + +you to do that with pertains +to this kind of friction, which + +is not present. + +No cigar. + +Nick says, how +about force gauge? + +Now, don't have it. + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: Yeah, we are. + +AUDIENCE: [INAUDIBLE] +displace the other one + +and then find the frequency. + +PROFESSOR: Oh, what's your name? + +Sean? + +Or John? + +AUDIENCE: Sean. + +PROFESSOR: Say that out loud. + +Say it loud enough that +Devin can hear you. + +AUDIENCE: You hold +the first mass, + +and then you displace +the second one. + +PROFESSOR: Hang on. + +He says, hold the first mass +like this set screw right here. + +And? + +AUDIENCE: And then displace +the other one then. + +PROFESSOR: Like that? + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: Actually, +to answer your question + +Nick, the only instrument +I have is a clock. + +Hang on a second. + +Here it is. + +Of course, this is the +big task is finding it. + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: Count to 10, +remember like Vandiver told you. + +Skip 1, 1, 2, 3, count to 10. + +Stop. + +Excellent, excellent, excellent. + +When you do that, +that's the second one. + +I did that and right +here, right here it's TP. + +The period of 10 of them-- +and then I divide to get 1-- + +is 0.83 seconds. + +What does that tell you, Sean? + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: Well +actually, these two-- + +you can get the frequency. + +But what this does, because +this gives you the frequency, + +you know in general +that-- in particular, you + +know that this second natural +frequency, which is just + +associated with this single +spring and a mass here. + +It's just this guy. + +It's not both of them. + +Anyway, this turns out +to-- I didn't graph that. + +That's square root of +K over M. Trust me, + +you can put those two +together, and you get + +K2 is equal to-- newton meters. + +This is exactly what you said. + +Freeze the first mass. + +Displace the second. + +Measure the period. + +You get the natural frequency +for basically K2 over M2. + +So you got K2 out of it. + +Yeah, Douglas? + +AUDIENCE: So how come it gives +you just the natural frequency + +and a damp natural frequency? + +PROFESSOR: Oh no. + +It absolutely is. + +It's all damped, no +question about it. + +But again, what +we're doing is we're + +going close enough, right? + +Because I have nothing. + +So even the damped +natural frequency + +is better than nothing. + +All right, so Amy back to you. + +You're back in business. + +What now? + +So now we've got M2 and K2. + +AUDIENCE: You just need K1. + +PROFESSOR: Yeah. + +Now we need K1. + +What do we do now? + +AUDIENCE: We want to do +the same thing that we just + +did for K2. [INAUDIBLE]. + +PROFESSOR: Exactly. + +Well, not quite. + +Let's see, now I'm going +to turn loose-- now we're + +back to our original system. + +It doesn't hurt anything. + +It's just ugly to look at. + +Now what? + +Sean, do that trick again. + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: Push this one up? + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: I don't think so. + +Yeah, Nick. + +AUDIENCE: So just +fix the second mass. + +PROFESSOR: Fix the second mass. + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: Yeah, you +see this frequency here? + +I'm going to overrule Chandler. + +I'm going to say, this is the +natural frequency of that's + +mass and these two springs. + +Do that same trick again. + +You get the equivalent +spring rate, + +subtract the second from it, +and you get the other one. + +Devin, is that what +you were going to say? + +Wonderful. + +That is exactly what I did. + +And you get out +of it, you get K1 + +is equal to 50.45 +newton per meter. + +In the interest of time, I'm +going to short circuit this. + +I took exactly +these parameters, I + +put them into that same +computer program we had before, + +and what came out-- I have +to have a place to put it. + +Ah, wonderful. + +And now I have to find it. + +Here we go. + +Here are the two modes. + +Actually, let me +put it right here. + +For this system, because +here's the first one. + +And here's the second one. + +0.9760 and minus 0.2177. + +Everybody appreciate that? + +This is by the same +computational procedure + +we spoke of earlier. + +And sparing no expense, +we have here a, made fresh + +from my basement, a custom +made initial condition setting + +device, which I can hopefully +avoid killing myself with. + +OK here's what we have. + +So I guess I didn't +show you this first. + +If you can see it, +what we have marked + +is the reference position. + +That's the rest position +that we couldn't + +find by laying it down. + +Or excuse me, this is the +static equilibrium position + +of mass number one, +static equilibrium + +position of mass number two. + +Mode one or there. + +What they said over there, 0.4. + +And .97 is down here. + +Mode two is over here. + +So Devin, while I'm +doing this, tell me + +how am I going to +know if this is right + +or if this is all just bogus? + +What observable's going to +tell me that I got it right? + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: I'm sorry, speak up. + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: How about it, Nick? + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: Exactly. + +And you ought to be able to +see it from where you are. + +Can you appreciate that +they're not at the moment? + +All right, now hang on. + +Here comes mode number one. + +This takes two hands to do it. + +All right, you ready? + +This is mode number one. + +Again, it's a those numbers. + +How about it? + +Can you see it? + +Very good. + +How about the other? + +And so here, this is number two. + +And this is a little +more complicated, + +because the other one has +to be done from the bottom. + +Hang on a second. + +Now this one we're doing +is we're deflecting-- + +this one is positive downward. + +So X1 is down, but +X2 is negative. + +So it's displaced upward a bit. + +Are you ready? + +Nick, what do you +expect to see this time? + +AUDIENCE: The frequency +should be higher + +and they'll move in +opposite directions. + +PROFESSOR: That's the key. + +Once again, they're going to +move with the same frequency, + +albeit in different directions. + +But that new frequency is +going to be higher than before. + +And sure enough, stand back. + +So there you go. + +What did that tell us? + +That told us that +the first order + +we got the system parameters +identified correctly + +and the theory holds up. + +Questions? + +Comments? + +Complaints? + +Devin? + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: I'm sorry? + +AUDIENCE: What was the +second set of conditions? + +PROFESSOR: The second +set of initial conditions + +were right here. + +This is the second mode, +X1, 0.97, X2, minus 0.2. + +OK, have a great +Thanksgiving holiday. \ No newline at end of file diff --git a/9JhX_UNcQvE.txt b/9JhX_UNcQvE.txt new file mode 100644 index 0000000000000000000000000000000000000000..5f3ad183d8a87ed2786ff9886dad3d14cfe6414e --- /dev/null +++ b/9JhX_UNcQvE.txt @@ -0,0 +1,2603 @@ +align:start position:0% + +okay the generate perturbation theory + + align:start position:0% +okay the generate perturbation theory + + + align:start position:0% +okay the generate perturbation theory +okay we've done nicely our non + + align:start position:0% +okay we've done nicely our non + + + align:start position:0% +okay we've done nicely our non +degenerate case so we'll get none + + align:start position:0% +degenerate case so we'll get none + + + align:start position:0% +degenerate case so we'll get none +degenerate + + align:start position:0% +degenerate + + + align:start position:0% +degenerate +degenerate done in a very clear way I + + align:start position:0% +degenerate done in a very clear way I + + + align:start position:0% +degenerate done in a very clear way I +think so the first thing I want to say + + align:start position:0% +think so the first thing I want to say + + + align:start position:0% +think so the first thing I want to say +about the generate perturbation theories + + align:start position:0% +about the generate perturbation theories + + + align:start position:0% +about the generate perturbation theories +when it fails and why it fails and what + + align:start position:0% +when it fails and why it fails and what + + + align:start position:0% +when it fails and why it fails and what +goes wrong so so the generate + + align:start position:0% +goes wrong so so the generate + + + align:start position:0% +goes wrong so so the generate +perturbation theory + + align:start position:0% + + + + align:start position:0% + +trivial example to begin with why not H + + align:start position:0% +trivial example to begin with why not H + + + align:start position:0% +trivial example to begin with why not H +of lambda again is equal to H 0 plus + + align:start position:0% +of lambda again is equal to H 0 plus + + + align:start position:0% +of lambda again is equal to H 0 plus +lambda Delta H and for H 0 will take + + align:start position:0% +lambda Delta H and for H 0 will take + + + align:start position:0% +lambda Delta H and for H 0 will take +original Hamiltonian with energies 1 and + + align:start position:0% +original Hamiltonian with energies 1 and + + + align:start position:0% +original Hamiltonian with energies 1 and +1 and for Delta H I'll take off diagonal + + align:start position:0% +1 and for Delta H I'll take off diagonal + + + align:start position:0% +1 and for Delta H I'll take off diagonal +Hamiltonian a poly matrix and that's our + + align:start position:0% +Hamiltonian a poly matrix and that's our + + + align:start position:0% +Hamiltonian a poly matrix and that's our +Delta H and we say ok blindly not + + align:start position:0% +Delta H and we say ok blindly not + + + align:start position:0% +Delta H and we say ok blindly not +worried about this degeneracy and use + + align:start position:0% +worried about this degeneracy and use + + + align:start position:0% +worried about this degeneracy and use +the formulas that we had for non + + align:start position:0% +the formulas that we had for non + + + align:start position:0% +the formulas that we had for non +degenerate States and we would say well + + align:start position:0% +degenerate States and we would say well + + + align:start position:0% +degenerate States and we would say well +for the first date and the second state + + align:start position:0% +for the first date and the second state + + + align:start position:0% +for the first date and the second state +what do we have + + align:start position:0% +what do we have + + + align:start position:0% +what do we have +e I'll call them 1 and 2 not 0 and 1 so + + align:start position:0% +e I'll call them 1 and 2 not 0 and 1 so + + + align:start position:0% +e I'll call them 1 and 2 not 0 and 1 so +let's call them 1 of lambda will be + + align:start position:0% +let's call them 1 of lambda will be + + + align:start position:0% +let's call them 1 of lambda will be +equal to the first value 1 plus if the + + align:start position:0% +equal to the first value 1 plus if the + + + align:start position:0% +equal to the first value 1 plus if the +formula is Right Delta H times lambda 1 + + align:start position:0% +formula is Right Delta H times lambda 1 + + + align:start position:0% +formula is Right Delta H times lambda 1 +1 the matrix element of the perturbation + + align:start position:0% +1 the matrix element of the perturbation + + + align:start position:0% +1 the matrix element of the perturbation +in the 1 1 state similarly e to the + + align:start position:0% +in the 1 1 state similarly e to the + + + align:start position:0% +in the 1 1 state similarly e to the +other eigenvalue should be 1 because the + + align:start position:0% +other eigenvalue should be 1 because the + + + align:start position:0% +other eigenvalue should be 1 because the +second eigenvalue plus lambda delta h 2 + + align:start position:0% +second eigenvalue plus lambda delta h 2 + + + align:start position:0% +second eigenvalue plus lambda delta h 2 +2 that's what the formula would say but + + align:start position:0% +2 that's what the formula would say but + + + align:start position:0% +2 that's what the formula would say but +this is completely incorrect why because + + align:start position:0% +this is completely incorrect why because + + + align:start position:0% +this is completely incorrect why because +Delta H 1 1 is the 1 1 element of Delta + + align:start position:0% +Delta H 1 1 is the 1 1 element of Delta + + + align:start position:0% +Delta H 1 1 is the 1 1 element of Delta +H and it's 0 and the 2 2 element of + + align:start position:0% +H and it's 0 and the 2 2 element of + + + align:start position:0% +H and it's 0 and the 2 2 element of +Delta H is all + + align:start position:0% +Delta H is all + + + align:start position:0% +Delta H is all +zero and therefore this says one and one + + align:start position:0% +zero and therefore this says one and one + + + align:start position:0% +zero and therefore this says one and one +that the eigenvalues haven't changed on + + align:start position:0% +that the eigenvalues haven't changed on + + + align:start position:0% +that the eigenvalues haven't changed on +the other hand we know that the matrix + + align:start position:0% +the other hand we know that the matrix + + + align:start position:0% +the other hand we know that the matrix +the total matrix which is one lambda + + align:start position:0% +the total matrix which is one lambda + + + align:start position:0% +the total matrix which is one lambda +lambda 1 has eigenvectors 1 over square + + align:start position:0% +lambda 1 has eigenvectors 1 over square + + + align:start position:0% +lambda 1 has eigenvectors 1 over square +root of 2 1 1 and 1 over square root of + + align:start position:0% +root of 2 1 1 and 1 over square root of + + + align:start position:0% +root of 2 1 1 and 1 over square root of +2 1 minus 1 with eigenvalues this is our + + align:start position:0% +2 1 minus 1 with eigenvalues this is our + + + align:start position:0% +2 1 minus 1 with eigenvalues this is our +eigenvectors and eigenvalues 1 plus + + align:start position:0% +eigenvectors and eigenvalues 1 plus + + + align:start position:0% +eigenvectors and eigenvalues 1 plus +lambda and 1 minus lambda so the + + align:start position:0% +lambda and 1 minus lambda so the + + + align:start position:0% +lambda and 1 minus lambda so the +eigenvalues of the matrix are 1 plus + + align:start position:0% +eigenvalues of the matrix are 1 plus + + + align:start position:0% +eigenvalues of the matrix are 1 plus +lambda 1 minus lambda and this formula + + align:start position:0% +lambda 1 minus lambda and this formula + + + align:start position:0% +lambda 1 minus lambda and this formula +to first order in lambda gave us nothing + + align:start position:0% +to first order in lambda gave us nothing + + + align:start position:0% +to first order in lambda gave us nothing +it failed badly it's a disaster so you + + align:start position:0% +it failed badly it's a disaster so you + + + align:start position:0% +it failed badly it's a disaster so you +can say well what what happened and + + align:start position:0% +can say well what what happened and + + + align:start position:0% +can say well what what happened and +maybe a clue is on the fact of the + + align:start position:0% +maybe a clue is on the fact of the + + + align:start position:0% +maybe a clue is on the fact of the +eigenvectors eigenvectors + + align:start position:0% + + + + align:start position:0% + +these are the eigenvectors of the total + + align:start position:0% +these are the eigenvectors of the total + + + align:start position:0% +these are the eigenvectors of the total +matrix these are in fact also the + + align:start position:0% +matrix these are in fact also the + + + align:start position:0% +matrix these are in fact also the +eigenvectors of the perturbation on the + + align:start position:0% +eigenvectors of the perturbation on the + + + align:start position:0% +eigenvectors of the perturbation on the +other hand when we said okay this is the + + align:start position:0% +other hand when we said okay this is the + + + align:start position:0% +other hand when we said okay this is the +first state the first eigenvector we + + align:start position:0% +first state the first eigenvector we + + + align:start position:0% +first state the first eigenvector we +thought of it as 1 0 and the hamiltonian + + align:start position:0% +thought of it as 1 0 and the hamiltonian + + + align:start position:0% +thought of it as 1 0 and the hamiltonian +on that eigenvector gave you the energy + + align:start position:0% +on that eigenvector gave you the energy + + + align:start position:0% +on that eigenvector gave you the energy +1 the second energy corresponds to the + + align:start position:0% +1 the second energy corresponds to the + + + align:start position:0% +1 the second energy corresponds to the +eigen vector 0 1 that's what we usually + + align:start position:0% +eigen vector 0 1 that's what we usually + + + align:start position:0% +eigen vector 0 1 that's what we usually +use for our matrices so here is the + + align:start position:0% +use for our matrices so here is the + + + align:start position:0% +use for our matrices so here is the +strange thing that seems to have + + align:start position:0% +strange thing that seems to have + + + align:start position:0% +strange thing that seems to have +happened for the original Hamiltonian + + align:start position:0% +happened for the original Hamiltonian + + + align:start position:0% +happened for the original Hamiltonian +did I ever a matrix we had this + + align:start position:0% +did I ever a matrix we had this + + + align:start position:0% +did I ever a matrix we had this +eigenvector and this eigenvector and + + align:start position:0% +eigenvector and this eigenvector and + + + align:start position:0% +eigenvector and this eigenvector and +then suddenly + + align:start position:0% +then suddenly + + + align:start position:0% +then suddenly +you turn on the perturbation and lambda + + align:start position:0% +you turn on the perturbation and lambda + + + align:start position:0% +you turn on the perturbation and lambda +can be 10 to the minus a thousand and + + align:start position:0% +can be 10 to the minus a thousand and + + + align:start position:0% +can be 10 to the minus a thousand and +already the eigenvectors jump and become + + align:start position:0% +already the eigenvectors jump and become + + + align:start position:0% +already the eigenvectors jump and become +this ones we go from this ones to that + + align:start position:0% +this ones we go from this ones to that + + + align:start position:0% +this ones we go from this ones to that +one you just add a perturbation that you + + align:start position:0% +one you just add a perturbation that you + + + align:start position:0% +one you just add a perturbation that you +even kind of measure in the eigenvectors + + align:start position:0% +even kind of measure in the eigenvectors + + + align:start position:0% +even kind of measure in the eigenvectors +change that's crazy + + align:start position:0% + + + + align:start position:0% + +the explanation is this thing that we + + align:start position:0% +the explanation is this thing that we + + + align:start position:0% +the explanation is this thing that we +usually sometimes forget to say in a + + align:start position:0% +usually sometimes forget to say in a + + + align:start position:0% +usually sometimes forget to say in a +mathematically precise way these are not + + align:start position:0% +mathematically precise way these are not + + + align:start position:0% +mathematically precise way these are not +the eigenvectors of the original matrix + + align:start position:0% +the eigenvectors of the original matrix + + + align:start position:0% +the eigenvectors of the original matrix +since the original matrix is degenerate + + align:start position:0% +since the original matrix is degenerate + + + align:start position:0% +since the original matrix is degenerate +this is one possible choice of + + align:start position:0% +this is one possible choice of + + + align:start position:0% +this is one possible choice of +eigenvectors any linear combination of + + align:start position:0% +eigenvectors any linear combination of + + + align:start position:0% +eigenvectors any linear combination of +them is an eigenvector so this space of + + align:start position:0% +them is an eigenvector so this space of + + + align:start position:0% +them is an eigenvector so this space of +eigenvectors of this matrix is the span + + align:start position:0% +eigenvectors of this matrix is the span + + + align:start position:0% +eigenvectors of this matrix is the span +of these things so there was no reason + + align:start position:0% +of these things so there was no reason + + + align:start position:0% +of these things so there was no reason +to say all this where the eigenvectors + + align:start position:0% +to say all this where the eigenvectors + + + align:start position:0% +to say all this where the eigenvectors +before and now they've change there are + + align:start position:0% +before and now they've change there are + + + align:start position:0% +before and now they've change there are +this no before you don't know what are + + align:start position:0% +this no before you don't know what are + + + align:start position:0% +this no before you don't know what are +the eigenvectors are ambiguous there's + + align:start position:0% +the eigenvectors are ambiguous there's + + + align:start position:0% +the eigenvectors are ambiguous there's +no way to decide who they are these days + + align:start position:0% +no way to decide who they are these days + + + align:start position:0% +no way to decide who they are these days +or any linear combination remember when + + align:start position:0% +or any linear combination remember when + + + align:start position:0% +or any linear combination remember when +you have a degenerate eigen state any + + align:start position:0% +you have a degenerate eigen state any + + + align:start position:0% +you have a degenerate eigen state any +superposition of them is at the general + + align:start position:0% +superposition of them is at the general + + + align:start position:0% +superposition of them is at the general +die again say so so the explanation is + + align:start position:0% +die again say so so the explanation is + + + align:start position:0% +die again say so so the explanation is +that in some sense these eigenvectors of + + align:start position:0% +that in some sense these eigenvectors of + + + align:start position:0% +that in some sense these eigenvectors of +the perturb hamiltonian is one of the + + align:start position:0% +the perturb hamiltonian is one of the + + + align:start position:0% +the perturb hamiltonian is one of the +possible choices of a basis of + + align:start position:0% +possible choices of a basis of + + + align:start position:0% +possible choices of a basis of +eigenvectors for the original space and + + align:start position:0% +eigenvectors for the original space and + + + align:start position:0% +eigenvectors for the original space and +what the perturbation does is break the + + align:start position:0% +what the perturbation does is break the + + + align:start position:0% +what the perturbation does is break the +degeneracy all those equivalent + + align:start position:0% +degeneracy all those equivalent + + + align:start position:0% +degeneracy all those equivalent +eigenvectors suddenly are not all + + align:start position:0% +eigenvectors suddenly are not all + + + align:start position:0% +eigenvectors suddenly are not all +equivalent and there's some preferred + + align:start position:0% +equivalent and there's some preferred + + + align:start position:0% +equivalent and there's some preferred +ones so this is going to be so the fact + + align:start position:0% +ones so this is going to be so the fact + + + align:start position:0% +ones so this is going to be so the fact +is that the formulas are not working + + align:start position:0% +is that the formulas are not working + + + align:start position:0% +is that the formulas are not working +right and we have to do this again + + align:start position:0% +right and we have to do this again + + + align:start position:0% +right and we have to do this again +so here's what we're gonna do we're + + align:start position:0% +so here's what we're gonna do we're + + + align:start position:0% +so here's what we're gonna do we're +gonna set this up for a systematic + + align:start position:0% +gonna set this up for a systematic + + + align:start position:0% +gonna set this up for a systematic +analysis to get this right so systematic + + align:start position:0% +analysis to get this right so systematic + + + align:start position:0% +analysis to get this right so systematic +analysis so again we say h0 is known and + + align:start position:0% +analysis so again we say h0 is known and + + + align:start position:0% +analysis so again we say h0 is known and +it will have an e of say 1 0 and e 2 0 + + align:start position:0% +it will have an e of say 1 0 and e 2 0 + + + align:start position:0% +it will have an e of say 1 0 and e 2 0 +like that until you encounter an e n 0 + + align:start position:0% +like that until you encounter an e n 0 + + + align:start position:0% +like that until you encounter an e n 0 +that happens to be equal to the next one + + align:start position:0% +that happens to be equal to the next one + + + align:start position:0% +that happens to be equal to the next one +e n plus 1 0 and happens to be equal to + + align:start position:0% +e n plus 1 0 and happens to be equal to + + + align:start position:0% +e n plus 1 0 and happens to be equal to +the next one all the way to an e n plus + + align:start position:0% +the next one all the way to an e n plus + + + align:start position:0% +the next one all the way to an e n plus +capital n minus 1 0 which is then + + align:start position:0% +capital n minus 1 0 which is then + + + align:start position:0% +capital n minus 1 0 which is then +smaller than the next one which is e n + + align:start position:0% +smaller than the next one which is e n + + + align:start position:0% +smaller than the next one which is e n +plus N and then again so I'm saying in + + align:start position:0% +plus N and then again so I'm saying in + + + align:start position:0% +plus N and then again so I'm saying in +funny ways the fact that yes you had + + align:start position:0% +funny ways the fact that yes you had + + + align:start position:0% +funny ways the fact that yes you had +some states and suddenly you hit a + + align:start position:0% +some states and suddenly you hit a + + + align:start position:0% +some states and suddenly you hit a +collection of capital n energy + + align:start position:0% +collection of capital n energy + + + align:start position:0% +collection of capital n energy +eigenvalues that are identical they're + + align:start position:0% +eigenvalues that are identical they're + + + align:start position:0% +eigenvalues that are identical they're +all equal to en 0 all n states have + + align:start position:0% +all equal to en 0 all n states have + + + align:start position:0% +all equal to en 0 all n states have +energy e n 0 so it is as if you have + + align:start position:0% +energy e n 0 so it is as if you have + + + align:start position:0% +energy e n 0 so it is as if you have +this matrix H 0 and there are all kinds + + align:start position:0% +this matrix H 0 and there are all kinds + + + align:start position:0% +this matrix H 0 and there are all kinds +of numbers and then there's a whole + + align:start position:0% +of numbers and then there's a whole + + + align:start position:0% +of numbers and then there's a whole +block where all the entries of size n by + + align:start position:0% +block where all the entries of size n by + + + align:start position:0% +block where all the entries of size n by +n where all the entries are the same so + + align:start position:0% +n where all the entries are the same so + + + align:start position:0% +n where all the entries are the same so +n n plus 1 n plus 2 up to n n capital n + + align:start position:0% +n n plus 1 n plus 2 up to n n capital n + + + align:start position:0% +n n plus 1 n plus 2 up to n n capital n +minus 1 is n entries and they all have + + align:start position:0% +minus 1 is n entries and they all have + + + align:start position:0% +minus 1 is n entries and they all have +the same energy + + align:start position:0% + + + + align:start position:0% + +and the corresponding eigen states are + + align:start position:0% +and the corresponding eigen states are + + + align:start position:0% +and the corresponding eigen states are +gonna be called and we're gonna use the + + align:start position:0% +gonna be called and we're gonna use the + + + align:start position:0% +gonna be called and we're gonna use the +label and for all of them even though + + align:start position:0% +label and for all of them even though + + + align:start position:0% +label and for all of them even though +they the energies are all the same so + + align:start position:0% +they the energies are all the same so + + + align:start position:0% +they the energies are all the same so +there's just an e/m energy so we have + + align:start position:0% +there's just an e/m energy so we have + + + align:start position:0% +there's just an e/m energy so we have +capital and state so there will be an N + + align:start position:0% +capital and state so there will be an N + + + align:start position:0% +capital and state so there will be an N +1 and n 2 up to an n capital n all those + + align:start position:0% +1 and n 2 up to an n capital n all those + + + align:start position:0% +1 and n 2 up to an n capital n all those +states are gonna form an orthonormal + + align:start position:0% + + + + align:start position:0% + +basis for a space that we're gonna call + + align:start position:0% +basis for a space that we're gonna call + + + align:start position:0% +basis for a space that we're gonna call +VM so the space spanned by this states + + align:start position:0% +VM so the space spanned by this states + + + align:start position:0% +VM so the space spanned by this states +we're going to call VN with the n + + align:start position:0% +we're going to call VN with the n + + + align:start position:0% +we're going to call VN with the n +reminding you it has to do with it n + + align:start position:0% +reminding you it has to do with it n + + + align:start position:0% +reminding you it has to do with it n +states little and states with energy + + align:start position:0% +states little and states with energy + + + align:start position:0% +states little and states with energy +described by the label n so this is the + + align:start position:0% +described by the label n so this is the + + + align:start position:0% +described by the label n so this is the +degenerate subspace this is the space of + + align:start position:0% +degenerate subspace this is the space of + + + align:start position:0% +degenerate subspace this is the space of +all those states that have energy E and + + align:start position:0% +all those states that have energy E and + + + align:start position:0% +all those states that have energy E and +0 so I'll state that here so it's quite + + align:start position:0% +0 so I'll state that here so it's quite + + + align:start position:0% +0 so I'll state that here so it's quite +important to get our notation right here + + align:start position:0% + + + + align:start position:0% + +otherwise we don't understand what's + + align:start position:0% +otherwise we don't understand what's + + + align:start position:0% +otherwise we don't understand what's +going on so H 0 and 0 K they all have + + align:start position:0% +going on so H 0 and 0 K they all have + + + align:start position:0% +going on so H 0 and 0 K they all have +energy e and 0 and 0 ok ok and this is + + align:start position:0% +energy e and 0 and 0 ok ok and this is + + + align:start position:0% +energy e and 0 and 0 ok ok and this is +for K equals 1 up to capital n now okay + + align:start position:0% +for K equals 1 up to capital n now okay + + + align:start position:0% +for K equals 1 up to capital n now okay +this is your degenerate subspace all + + align:start position:0% +this is your degenerate subspace all + + + align:start position:0% +this is your degenerate subspace all +these are all the states and we now want + + align:start position:0% +these are all the states and we now want + + + align:start position:0% +these are all the states and we now want +to know what happens to this space to + + align:start position:0% +to know what happens to this space to + + + align:start position:0% +to know what happens to this space to +all these states when the energy turns + + align:start position:0% +all these states when the energy turns + + + align:start position:0% +all these states when the energy turns +this is not just a theoretical construct + + align:start position:0% +this is not just a theoretical construct + + + align:start position:0% +this is not just a theoretical construct +when you start asking what happens to + + align:start position:0% +when you start asking what happens to + + + align:start position:0% +when you start asking what happens to +the first excited states in the hydrogen + + align:start position:0% +the first excited states in the hydrogen + + + align:start position:0% +the first excited states in the hydrogen +atom you already have four states there + + align:start position:0% +atom you already have four states there + + + align:start position:0% +atom you already have four states there +L equal 1 l equals 0 States at n equal 2 + + align:start position:0% +L equal 1 l equals 0 States at n equal 2 + + + align:start position:0% +L equal 1 l equals 0 States at n equal 2 +and half degenerate States and + + align:start position:0% +and half degenerate States and + + + align:start position:0% +and half degenerate States and +immediately you're stuck in this + + align:start position:0% +immediately you're stuck in this + + + align:start position:0% +immediately you're stuck in this +situation so I will also use the + + align:start position:0% +situation so I will also use the + + + align:start position:0% +situation so I will also use the +notation that the total space space a + + align:start position:0% + + + + align:start position:0% + +curly H is the sum of V and plus a V hot + + align:start position:0% +curly H is the sum of V and plus a V hot + + + align:start position:0% +curly H is the sum of V and plus a V hot +this is called the direct sum at this + + align:start position:0% +this is called the direct sum at this + + + align:start position:0% +this is called the direct sum at this +point it just doesn't matter too much + + align:start position:0% +point it just doesn't matter too much + + + align:start position:0% +point it just doesn't matter too much +these are linearly independent subspaces + + align:start position:0% +these are linearly independent subspaces + + + align:start position:0% +these are linearly independent subspaces +be and be hot and basically you think + + align:start position:0% +be and be hot and basically you think + + + align:start position:0% +be and be hot and basically you think +does V hot as all the other states yes + + align:start position:0% +does V hot as all the other states yes + + + align:start position:0% +does V hot as all the other states yes +there were this degenerate subspace and + + align:start position:0% +there were this degenerate subspace and + + + align:start position:0% +there were this degenerate subspace and +all the other states are we had so we + + align:start position:0% +all the other states are we had so we + + + align:start position:0% +all the other states are we had so we +had is the span of all other states and + + align:start position:0% +had is the span of all other states and + + + align:start position:0% +had is the span of all other states and +we'll call them p 0 or what letter are p + + align:start position:0% +we'll call them p 0 or what letter are p + + + align:start position:0% +we'll call them p 0 or what letter are p +0 with P equals some numbers so this is + + align:start position:0% +0 with P equals some numbers so this is + + + align:start position:0% +0 with P equals some numbers so this is +a good notation it allows you to + + align:start position:0% +a good notation it allows you to + + + align:start position:0% +a good notation it allows you to +distinguish the degenerate States use + + align:start position:0% +distinguish the degenerate States use + + + align:start position:0% +distinguish the degenerate States use +two labels maybe you only need at one + + align:start position:0% +two labels maybe you only need at one + + + align:start position:0% +two labels maybe you only need at one +label but you would get confused with + + align:start position:0% +label but you would get confused with + + + align:start position:0% +label but you would get confused with +the notation if you just use one labor + + align:start position:0% +the notation if you just use one labor + + + align:start position:0% +the notation if you just use one labor +so if that's the case the generate state + + align:start position:0% +so if that's the case the generate state + + + align:start position:0% +so if that's the case the generate state +but by putting the end here you now know + + align:start position:0% +but by putting the end here you now know + + + align:start position:0% +but by putting the end here you now know +you're talking at the generate state + + align:start position:0% +you're talking at the generate state + + + align:start position:0% +you're talking at the generate state +when you have a single label you're + + align:start position:0% +when you have a single label you're + + + align:start position:0% +when you have a single label you're +talking about the other states in the + + align:start position:0% +talking about the other states in the + + + align:start position:0% +talking about the other states in the +space so it's very good when your + + align:start position:0% +space so it's very good when your + + + align:start position:0% +space so it's very good when your +notation + + align:start position:0% +notation + + + align:start position:0% +notation +makes it easy to think and recognize the + + align:start position:0% +makes it easy to think and recognize the + + + align:start position:0% +makes it easy to think and recognize the +equations that you have and V Hart and + + align:start position:0% +equations that you have and V Hart and + + + align:start position:0% +equations that you have and V Hart and +this are orthogonal spaces we've had is + + align:start position:0% +this are orthogonal spaces we've had is + + + align:start position:0% +this are orthogonal spaces we've had is +perpendicular to V n the inner product + + align:start position:0% +perpendicular to V n the inner product + + + align:start position:0% +perpendicular to V n the inner product +of any state outside the generate space + + align:start position:0% +of any state outside the generate space + + + align:start position:0% +of any state outside the generate space +with a state in the degenerate space is + + align:start position:0% +with a state in the degenerate space is + + + align:start position:0% +with a state in the degenerate space is +zero okay so let's up now do the + + align:start position:0% +zero okay so let's up now do the + + + align:start position:0% +zero okay so let's up now do the +important thing should I can do it here + + align:start position:0% +important thing should I can do it here + + + align:start position:0% +important thing should I can do it here +I think I'll do it here so what do we + + align:start position:0% +I think I'll do it here so what do we + + + align:start position:0% +I think I'll do it here so what do we +want to do what is the question here the + + align:start position:0% +want to do what is the question here the + + + align:start position:0% +want to do what is the question here the +question is the following we have a + + align:start position:0% +question is the following we have a + + + align:start position:0% +question is the following we have a +state and zero K we have capital n of + + align:start position:0% +state and zero K we have capital n of + + + align:start position:0% +state and zero K we have capital n of +those states and we want to figure out + + align:start position:0% +those states and we want to figure out + + + align:start position:0% +those states and we want to figure out +what they become as you turn on the + + align:start position:0% +what they become as you turn on the + + + align:start position:0% +what they become as you turn on the +perturbation so what using the old + + align:start position:0% +perturbation so what using the old + + + align:start position:0% +perturbation so what using the old +notation we'll say they become this and + + align:start position:0% +notation we'll say they become this and + + + align:start position:0% +notation we'll say they become this and +what is that gonna be it's gonna be M 0 + + align:start position:0% +what is that gonna be it's gonna be M 0 + + + align:start position:0% +what is that gonna be it's gonna be M 0 +K the original state what it was plus + + align:start position:0% +K the original state what it was plus + + + align:start position:0% +K the original state what it was plus +order lambda the first correction so and + + align:start position:0% +order lambda the first correction so and + + + align:start position:0% +order lambda the first correction so and +one for this case state plus dot o dot + + align:start position:0% +one for this case state plus dot o dot + + + align:start position:0% +one for this case state plus dot o dot +for the energies we had em0 that was the + + align:start position:0% +for the energies we had em0 that was the + + + align:start position:0% +for the energies we had em0 that was the +energy of every state in the degenerate + + align:start position:0% +energy of every state in the degenerate + + + align:start position:0% +energy of every state in the degenerate +subspace now it's gonna become T and + + align:start position:0% +subspace now it's gonna become T and + + + align:start position:0% +subspace now it's gonna become T and +lambda P and lambda + + align:start position:0% +lambda P and lambda + + + align:start position:0% +lambda P and lambda +but if I say en and I'm already making a + + align:start position:0% +but if I say en and I'm already making a + + + align:start position:0% +but if I say en and I'm already making a +mistake + + align:start position:0% +mistake + + + align:start position:0% +mistake +because I'm looking at the fixed K and a + + align:start position:0% +because I'm looking at the fixed K and a + + + align:start position:0% +because I'm looking at the fixed K and a +fixed K means we chose one of the state + + align:start position:0% +fixed K means we chose one of the state + + + align:start position:0% +fixed K means we chose one of the state +and any single one of the state the + + align:start position:0% +and any single one of the state the + + + align:start position:0% +and any single one of the state the +energy can grow in a different way + + align:start position:0% +energy can grow in a different way + + + align:start position:0% +energy can grow in a different way +so I should call this emk because we're + + align:start position:0% +so I should call this emk because we're + + + align:start position:0% +so I should call this emk because we're +talking about this state will be equal + + align:start position:0% +talking about this state will be equal + + + align:start position:0% +talking about this state will be equal +to e and zero yes they all have the same + + align:start position:0% +to e and zero yes they all have the same + + + align:start position:0% +to e and zero yes they all have the same +first + + align:start position:0% +first + + + align:start position:0% +first +zeroth-order energy but then e MK 1 plus + + align:start position:0% +zeroth-order energy but then e MK 1 plus + + + align:start position:0% +zeroth-order energy but then e MK 1 plus +lambda squared e MK 2 and so on so this + + align:start position:0% +lambda squared e MK 2 and so on so this + + + align:start position:0% +lambda squared e MK 2 and so on so this +is the fate of the cave State and the + + align:start position:0% +is the fate of the cave State and the + + + align:start position:0% +is the fate of the cave State and the +degeneracy will be broken to first order + + align:start position:0% +degeneracy will be broken to first order + + + align:start position:0% +degeneracy will be broken to first order +if this e n case become different + + align:start position:0% +if this e n case become different + + + align:start position:0% +if this e n case become different +numbers because if they become different + + align:start position:0% +numbers because if they become different + + + align:start position:0% +numbers because if they become different +numbers in lambda they're going to start + + align:start position:0% +numbers in lambda they're going to start + + + align:start position:0% +numbers in lambda they're going to start +splitting the states remember this + + align:start position:0% +splitting the states remember this + + + align:start position:0% +splitting the states remember this +picture we had last time of several + + align:start position:0% +picture we had last time of several + + + align:start position:0% +picture we had last time of several +states at one point if the order lambda + + align:start position:0% +states at one point if the order lambda + + + align:start position:0% +states at one point if the order lambda +Corrections are different the state + + align:start position:0% +Corrections are different the state + + + align:start position:0% +Corrections are different the state +split the degeneracy is resolved and we + + align:start position:0% +split the degeneracy is resolved and we + + + align:start position:0% +split the degeneracy is resolved and we +can calculate things more easily if it's + + align:start position:0% +can calculate things more easily if it's + + + align:start position:0% +can calculate things more easily if it's +not resolved to first order it's harder + + align:start position:0% +not resolved to first order it's harder + + + align:start position:0% +not resolved to first order it's harder +it will be all of next lecture to figure + + align:start position:0% +it will be all of next lecture to figure + + + align:start position:0% +it will be all of next lecture to figure +out what happens in that case we + + align:start position:0% +out what happens in that case we + + + align:start position:0% +out what happens in that case we +discussed last time that the N one + + align:start position:0% +discussed last time that the N one + + + align:start position:0% +discussed last time that the N one +correction didn't have any component + + align:start position:0% +correction didn't have any component + + + align:start position:0% +correction didn't have any component +along the n zero vector we could always + + align:start position:0% +along the n zero vector we could always + + + align:start position:0% +along the n zero vector we could always +arrange that to happen here we can + + align:start position:0% +arrange that to happen here we can + + + align:start position:0% +arrange that to happen here we can +arrange something similar to happen so + + align:start position:0% +arrange something similar to happen so + + + align:start position:0% +arrange something similar to happen so +we will still assume assume and we can + + align:start position:0% +we will still assume assume and we can + + + align:start position:0% +we will still assume assume and we can +check that's always possible that the N + + align:start position:0% +check that's always possible that the N + + + align:start position:0% +check that's always possible that the N +P corrections to the state K at order P + + align:start position:0% + + + + align:start position:0% + +for P equals 1 2 3 because it's not 0 + + align:start position:0% +for P equals 1 2 3 because it's not 0 + + + align:start position:0% +for P equals 1 2 3 because it's not 0 +are orthogonal to n 0 K so this state + + align:start position:0% +are orthogonal to n 0 K so this state + + + align:start position:0% +are orthogonal to n 0 K so this state +doesn't have any component along n 0 K + + align:start position:0% +doesn't have any component along n 0 K + + + align:start position:0% +doesn't have any component along n 0 K +and this state doesn't have any company + + align:start position:0% +and this state doesn't have any company + + + align:start position:0% +and this state doesn't have any company +along the original one it's always + + align:start position:0% +along the original one it's always + + + align:start position:0% +along the original one it's always +possible to do that just like we did it + + align:start position:0% +possible to do that just like we did it + + + align:start position:0% +possible to do that just like we did it +in the degenerate non degenerate case + + align:start position:0% + + + + align:start position:0% + +moreover but here is this is something I + + align:start position:0% +moreover but here is this is something I + + + align:start position:0% +moreover but here is this is something I +want you to notice we're saying that the + + align:start position:0% +want you to notice we're saying that the + + + align:start position:0% +want you to notice we're saying that the +state and one doesn't have any component + + align:start position:0% +state and one doesn't have any component + + + align:start position:0% +state and one doesn't have any component +along the state and 0 for a given K but + + align:start position:0% +along the state and 0 for a given K but + + + align:start position:0% +along the state and 0 for a given K but +the state and one can have components + + align:start position:0% +the state and one can have components + + + align:start position:0% +the state and one can have components +along and 0 for a different K so while + + align:start position:0% +along and 0 for a different K so while + + + align:start position:0% +along and 0 for a different K so while +the answer or a piece order correction + + align:start position:0% +the answer or a piece order correction + + + align:start position:0% +the answer or a piece order correction +doesn't have component along this it can + + align:start position:0% +doesn't have component along this it can + + + align:start position:0% +doesn't have component along this it can +have component for K for an L here where + + align:start position:0% +have component for K for an L here where + + + align:start position:0% +have component for K for an L here where +L is different from k so it means that n + + align:start position:0% +L is different from k so it means that n + + + align:start position:0% +L is different from k so it means that n +P K still can have a component in VN + + align:start position:0% +P K still can have a component in VN + + + align:start position:0% +P K still can have a component in VN +remember V n is this whole thing so if + + align:start position:0% +remember V n is this whole thing so if + + + align:start position:0% +remember V n is this whole thing so if +you're doing the case one well n 1k + + align:start position:0% +you're doing the case one well n 1k + + + align:start position:0% +you're doing the case one well n 1k +doesn't have a number along that one but + + align:start position:0% +doesn't have a number along that one but + + + align:start position:0% +doesn't have a number along that one but +it may have a component along all the + + align:start position:0% +it may have a component along all the + + + align:start position:0% +it may have a component along all the +others so it may still have a component + + align:start position:0% +others so it may still have a component + + + align:start position:0% +others so it may still have a component +that correction in VN in fact that's + + align:start position:0% +that correction in VN in fact that's + + + align:start position:0% +that correction in VN in fact that's +what will make the problem a little hard + + align:start position:0% +what will make the problem a little hard + + + align:start position:0% +what will make the problem a little hard +to do but it's a good thing to try to + + align:start position:0% +to do but it's a good thing to try to + + + align:start position:0% +to do but it's a good thing to try to +figure out this thing so what is the + + align:start position:0% +figure out this thing so what is the + + + align:start position:0% +figure out this thing so what is the +equation we want to solve the usual + + align:start position:0% +equation we want to solve the usual + + + align:start position:0% +equation we want to solve the usual +equation H of lambda on MK lambda is + + align:start position:0% +equation H of lambda on MK lambda is + + + align:start position:0% +equation H of lambda on MK lambda is +equal to + + align:start position:0% +equal to + + + align:start position:0% +equal to +m'kay of lambda and K so we produce the + + align:start position:0% +m'kay of lambda and K so we produce the + + + align:start position:0% +m'kay of lambda and K so we produce the +general state that's its energy for the + + align:start position:0% +general state that's its energy for the + + + align:start position:0% +general state that's its energy for the +full final tone Ian that's our + + align:start position:0% +full final tone Ian that's our + + + align:start position:0% +full final tone Ian that's our +Schrodinger equation so what do we have + + align:start position:0% +Schrodinger equation so what do we have + + + align:start position:0% +Schrodinger equation so what do we have +to do we have to do exactly what we did + + align:start position:0% +to do we have to do exactly what we did + + + align:start position:0% +to do we have to do exactly what we did +before plugging that series separate the + + align:start position:0% +before plugging that series separate the + + + align:start position:0% +before plugging that series separate the +terms with various lambdas and see what + + align:start position:0% +terms with various lambdas and see what + + + align:start position:0% +terms with various lambdas and see what +we get so here is what we get to order + + align:start position:0% +we get so here is what we get to order + + + align:start position:0% +we get so here is what we get to order +lambda to the 0 you get H 0 minus M 0 on + + align:start position:0% +lambda to the 0 you get H 0 minus M 0 on + + + align:start position:0% +lambda to the 0 you get H 0 minus M 0 on +n 0 k equals 0 and that equation as it + + align:start position:0% +n 0 k equals 0 and that equation as it + + + align:start position:0% +n 0 k equals 0 and that equation as it +was the case for the non degenerate case + + align:start position:0% +was the case for the non degenerate case + + + align:start position:0% +was the case for the non degenerate case +sorry for the redundancy it's trivially + + align:start position:0% +sorry for the redundancy it's trivially + + + align:start position:0% +sorry for the redundancy it's trivially +satisfied we've stated that those are + + align:start position:0% +satisfied we've stated that those are + + + align:start position:0% +satisfied we've stated that those are +the energies in the top equation on that + + align:start position:0% +the energies in the top equation on that + + + align:start position:0% +the energies in the top equation on that +blackboard so this equation we don't + + align:start position:0% +blackboard so this equation we don't + + + align:start position:0% +blackboard so this equation we don't +need to worry about that's not too + + align:start position:0% +need to worry about that's not too + + + align:start position:0% +need to worry about that's not too +difficult lambda 1 H 0 minus e + 0 + 1 K + + align:start position:0% +difficult lambda 1 H 0 minus e + 0 + 1 K + + + align:start position:0% +difficult lambda 1 H 0 minus e + 0 + 1 K +will be equal to e MK 1 minus Delta H + + + align:start position:0% +will be equal to e MK 1 minus Delta H + + + + align:start position:0% +will be equal to e MK 1 minus Delta H + +0 K + + align:start position:0% + + + + align:start position:0% + +last equation starting to get lazy to + + align:start position:0% +last equation starting to get lazy to + + + align:start position:0% +last equation starting to get lazy to +write them out but we must and to K is + + align:start position:0% +write them out but we must and to K is + + + align:start position:0% +write them out but we must and to K is +equal to M e MK 1 minus Delta H and 1 k + + align:start position:0% +equal to M e MK 1 minus Delta H and 1 k + + + align:start position:0% +equal to M e MK 1 minus Delta H and 1 k +plus e MK 2 and 0 k ok and these + + align:start position:0% +plus e MK 2 and 0 k ok and these + + + align:start position:0% +plus e MK 2 and 0 k ok and these +equations are equations for K fixed but + + align:start position:0% +equations are equations for K fixed but + + + align:start position:0% +equations are equations for K fixed but +this every term in the equation has the + + align:start position:0% +this every term in the equation has the + + + align:start position:0% +this every term in the equation has the +same K but K then can run from 1 up to n + + align:start position:0% +same K but K then can run from 1 up to n + + + align:start position:0% +same K but K then can run from 1 up to n +so three equations terms n times there + + align:start position:0% +so three equations terms n times there + + + align:start position:0% +so three equations terms n times there +we go okay these are our equations this + + align:start position:0% +we go okay these are our equations this + + + align:start position:0% +we go okay these are our equations this +time and we need to understand them in + + align:start position:0% +time and we need to understand them in + + + align:start position:0% +time and we need to understand them in +fact we need to solve them what with + + align:start position:0% +fact we need to solve them what with + + + align:start position:0% +fact we need to solve them what with +getting experience with the non + + align:start position:0% +getting experience with the non + + + align:start position:0% +getting experience with the non +degenerate case is going to come very + + align:start position:0% +degenerate case is going to come very + + + align:start position:0% +degenerate case is going to come very +useful here although some things are not + + align:start position:0% +useful here although some things are not + + + align:start position:0% +useful here although some things are not +going to be exactly the same we're going + + align:start position:0% +going to be exactly the same we're going + + + align:start position:0% +going to be exactly the same we're going +to try to find the energy Corrections + + align:start position:0% +to try to find the energy Corrections + + + align:start position:0% +to try to find the energy Corrections +here but calculating the state and one + + align:start position:0% +here but calculating the state and one + + + align:start position:0% +here but calculating the state and one +is going to be a little harder we won't + + align:start position:0% +is going to be a little harder we won't + + + align:start position:0% +is going to be a little harder we won't +finish today we'll have much time left + + align:start position:0% +finish today we'll have much time left + + + align:start position:0% +finish today we'll have much time left +but what's going to happen is that you + + align:start position:0% +but what's going to happen is that you + + + align:start position:0% +but what's going to happen is that you +can calculate the state and one the part + + align:start position:0% +can calculate the state and one the part + + + align:start position:0% +can calculate the state and one the part +in the space we had but the part in the + + align:start position:0% +in the space we had but the part in the + + + align:start position:0% +in the space we had but the part in the +degenerate subspace where I said that n + + align:start position:0% +degenerate subspace where I said that n + + + align:start position:0% +degenerate subspace where I said that n +PK still can have a component in the + + align:start position:0% +PK still can have a component in the + + + align:start position:0% +PK still can have a component in the +degenerate subspace cannot be calculated + + align:start position:0% +degenerate subspace cannot be calculated + + + align:start position:0% +degenerate subspace cannot be calculated +from this equation so even when we + + align:start position:0% +from this equation so even when we + + + align:start position:0% +from this equation so even when we +finish doing this first equation + + align:start position:0% +finish doing this first equation + + + align:start position:0% +finish doing this first equation +you're gonna find the situation you + + align:start position:0% +you're gonna find the situation you + + + align:start position:0% +you're gonna find the situation you +still have not calculated all of the + + align:start position:0% +still have not calculated all of the + + + align:start position:0% +still have not calculated all of the +steps and one you're gonna have to go to + + align:start position:0% +steps and one you're gonna have to go to + + + align:start position:0% +steps and one you're gonna have to go to +the second equation to find the missing + + align:start position:0% +the second equation to find the missing + + + align:start position:0% +the second equation to find the missing +part of the state and one so it's gonna + + align:start position:0% +part of the state and one so it's gonna + + + align:start position:0% +part of the state and one so it's gonna +be pretty interesting \ No newline at end of file diff --git a/9Jry5-82I68.txt b/9Jry5-82I68.txt new file mode 100644 index 0000000000000000000000000000000000000000..b1e0a5def0dd5eb6c3873d3e788cd9875af92b7d --- /dev/null +++ b/9Jry5-82I68.txt @@ -0,0 +1,2497 @@ +The following +content is provided + +under a Creative +Commons license. + +Your support will help MIT +OpenCourseWare continue + +to offer high quality +educational resources for free. + +To make a donation or +view additional materials + +from hundreds of MIT courses, +visit MIT OpenCourseWare + +at ocw.mit.edu. + +PROFESSOR: Today's lecture +is about a brand new data + +structure that you've +probably seen before, + +and we've mentioned +earlier in double 06, + +called a binary search tree. + +We've talked about +binary search. + +It's a fundamental divide +and conquer paradigm. + +There's a data structure +associated with it, + +called the BST, a +binary search tree. + +And what I want to do is +motivate this data structure + +using a problem. + +It's a bit of a toy problem, +but certainly a problem + +that you could imagine +exists in all sorts + +of scheduling problems. + +It's a part of a runway +reservation system + +that you can imagine building. + +And what I'll do is +define this problem + +and talk about how we could +possibly solve it with the data + +structures you've already seen-- +so lists and arrays, heaps + +as well as, which +we saw last time-- + +and hopefully motivate you into +the reason behind the existence + +of binary search +trees, because they + +are kind of the +perfect data structure + +for this particular problem. + +So let's dive into what the +runway reservation system looks + +like. + +And it's your basic +scheduling problem. + +We'll assume an airport +with a single runway. + +Now Logan has six runways. + +But the moment there's any sort +of weather you're down to one. + +And of course, there's lots of +airports with a single runway. + +And we can imagine that +this runway is pretty busy. + +There's obviously safety issues +associated with landing planes, + +and planes taking off. + +And so there are +constraints associated + +with the system, that +have to be obeyed. + +And you have to build these +constraints in-- and the checks + +for these constraints-- +into your data structure. + +That's sort of the +summary of the context. + +So reservations +for future landings + +is really what this +system is built for. + +There's a notion of time. + +We'll assume that +time is continuous. + +So it could be represented +by a real variable, + +or a real quantity. + +And what we'd like to do is +reserve requests for landings. + +And these are going to +specify landing time. + +Each of them is going to +specify a landing time. + +We call it t. + +And in particular, +we're going to add t + +to the set R of landing times if +no other landings are scheduled + +within k minutes. + +And k is a parameter +that could vary. + +I mean, it could be statically +set to 3 minutes, or maybe 4. + +You can imagine it +varying it dynamically + +depending on weather +conditions, things like that. + +For the most of the examples +we'll talk about today, + +we'll assume k is 3 minutes, +or something like that. + +So this is about adding +to the data structure. + +And so an insert +operation, if you will, + +that has a constraint associated +with it that you need to check. + +And so you wouldn't insert if +the constraint was violated. + +You would if the +constraint was satisfied. + +And time, as I +said, is something + +that is part of the system. + +It needs to be modeled. + +You have the current +notion of time. + +And every time you have a +plane that's already landed, + +which means that +you can essentially + +take this particular +landing time away + +from the set R. So this +removal, or delete-- we remove + +from set R, which is +the set of landing times + +after the plane lands. + +So every once in awhile, +as time increments, + +you're going to be checking +the data structure. + +And you can do this, maybe, +every minute, every 30 seconds. + +That isn't really important. + +But you have to be able +to remove from this data + +structure. + +So fairly straightforward +data structure. + +It's a set, R. We don't quite +know how to implement it yet. + +But we'd like to do all of these +operations in order log n time, + +where n is the size of the set. + +All right? + +So any questions about that? + +Any questions about +the definition + +of the problem +before we move on? + +Are we good on? + +OK. + +So let's look at a real +straightforward example, + +and put this up here so you +get a better sense of this. + +Let's say that, right +now, we are at time 37. + +And the set R has +41.2, 49, and 53 in it. + +And that's time. + +Now you may get a request +for landing time 53. + +And-- I'm sorry. + +I want to call this +56.3-- 41.2, 49, and 56.3. + +You may get a request +for landing time 53. + +And right now the time is 37. + +It's in the future, and +you say OK because you've + +done the check. + +And let's assume +that k equals 3. + +And 53 is four ahead of 49, and +3.3 before 56.3, so you're OK. + +44 is not allowed. + +It's too close to 41.2. + +And 20, just for +completeness, is not + +allowed because it's passed. + +Can't schedule in the past. + +I mean, it could +be the next day. + +But then you +wouldn't call it 20. + +Let's assume that time is +a monotonically increasing + +function. + +You have a 64-bit number. + +It can go to the end +of the world, or 2012, + +or wherever you want. + +So you can keep the +number a bit smaller, + +and do a little constant +factor optimization, I guess. + +So that's sort of the set up. + +And hopefully you get a sense +of what the requirements. + +And you guys know about a bunch +of data structures already. + +And what I want to do is +list each one of them, + +and essentially shoot +them down with respect + +to not being able to make +this efficiency requirement. + +And I'd like you guys to +help me shoot them down. + +So let's talk about +an easy one first. + +Let's say you have an unsorted +list or an array corresponding + +to R. That's all you have. + +What's wrong with +this data structure + +from an efficiency standpoint? + +Yeah. + +AUDIENCE: Pretty much everything +you want to do to it is linear. + +PROFESSOR: That's exactly right. + +Pretty much everything you +want to do to it is linear. + +And so you want to check +the k minute check. + +You can certainly insert +into it, and just add to it. + +So that part is not linear, +that's constant time. + +But certainly, +anything where you + +want to go check against +other elements of the array, + +it's unsorted. + +You have no idea of where +to find these elements. + +You have to scan +through the entire array + +to check to see whether +there's a landing time that's + +within k of the current time +t that you're asking for. + +And that's going to +take order n time. + +So you can insert in +order 1 without a check. + +But sadly, the check +takes order n time. + +All right? + +Let's do something that is +a little more plausible. + +Let's talk about a sorted array. + +So this is a little +more subtle question. + +Let's talk about a sorted array. + +What happens with +a sorted array? + +Someone? + +What can you do +with a sorted array? + +Yeah. + +AUDIENCE: Do a binary search +to find the [INAUDIBLE]. + +PROFESSOR: Binary search +would find a bad insert. + +OK, good. + +So that's good. + +So if you have a sorted array, +and just for argument's sake, + +it looks like 4, 20, 32, 37, 45. + +And it's increasing order. + +And if you get a particular time +t, you can use binary search. + +And let's say, in particular, +the time is, for example, 34. + +Then what you do is you go +to the midpoint of the array, + +and maybe you just look at that. + +And you say oh, 34 +is greater than 32. + +So I'm going to go +check and figure out + +if I need to move to +the left or the right. + +And since it's greater I'm +going to move to the right. + +And within logarithmic +time, you'll + +find what we call the insertion +point of the sorted array, + +where this 34 is +supposed to sit. + +And you don't necessarily +get to insert there. + +You need to look, once you've +found the insertion point, + +to your left and to your right. + +And do the k minute check. + +So finish up the +answer to the question, + +tell me how long it's going to +take me to find the insertion + +point, how long it's going +to take me to do the check, + +and how long it's going +to take me to actually do + +the insertion. + +AUDIENCE: Log n in the search-- + +PROFESSOR: Log n for the +search, to find the point. + +AUDIENCE: Constant +for the comparison? + +PROFESSOR: Constant +to the comparison. + +And then the last step? + +AUDIENCE: Do the +research [INAUDIBLE]. + +PROFESSOR: Sorry, little louder. + +Sorry. + +AUDIENCE: The +insertion is constant. + +PROFESSOR: Insertion +is constant? + +Is that right? + +Do you people agree with him, +that insertion is constant? + +AUDIENCE: You've got a +maximum size up there, right? + +There must be a maximum. + +[INAUDIBLE] + +PROFESSOR: No, the indices-- +so right now the array + +has indices i. + +And if you start with 1, it's +1, 2, 3, 4, 5, et cetera. + +So what do you +mean by insertion? + +Someone explain to me +what-- yeah, go ahead. + +AUDIENCE: When you +put something in you + +have to shift +every element over. + +PROFESSOR: That's exactly right. + +That's exactly right. + +Ok, good, that's great. + +I guess I should give +you half a cushion. + +But I'll do the full one, right? + +And you get one, too. + +So the point here is +this is pretty close. + +It's almost what we want. + +It's almost what we want. + +There's a little bit +of a glitch here. + +We know about binary search. + +The binary search is +going to allow us, + +if there's n elements +here, to find the place-- + +it's going to be able +to find-- and I'm + +going to precise here-- the +smallest i such that R of i + +is greater than or equal +to t in order log n time. + +It's going to be +able to do that. + +You're going to be able to +compare R of i and R of i + +minus 1-- so the left +and the right-- against t + +in order 1 time. + +But sadly, the actual insertion +is going to require shifting. + +And that could take order n +time, because it's an array. + +So that's the problem. + +Now you could imagine that +you had a sorted list. + +And you could say, hey +if I have a sorted list, + +then the list looks +like this, and it's + +got a bunch of pointers in it. + +And if I've found +the insertion point, + +then-- the list is nice, +because you can insert something + +by moving pointers +in constant time + +once you've found +the insertion point. + +But what's the +problem with the list? + +Yeah. + +AUDIENCE: You can't do +binary search [INAUDIBLE]. + +PROFESSOR: Well you can't +do binary search on a list. + +There's no notion of +going to the n by 2 index + +and doing random access on +a conventional list, right? + +So the list does +one thing right, + +but doesn't do the +other thing right. + +The array does a +couple things right, + +but doesn't do the +shifting right. + +And so you see why we've +constructed this toy problem. + +It's to motivate the +binary search tree data + +structure, obviously. + +But you're close, +but not quite there. + +What about heaps? + +We talked about heaps last time. + +What's the basic problem with +the heap for this problem? + +The heaps are data +arrays, but you + +can visualize them as trees. + +And obviously if we're talking +about min heaps and max heaps. + +So in particular, what goes +wrong with a min heap or a max + +heap for this problem? + +What takes a long time? + +Yeah. + +AUDIENCE: You have to scan every +element, which [INAUDIBLE]. + +PROFESSOR: That's right. + +I mean, sadly, you know when +we talk about min heaps or max + +heaps, they actually have +a fairly weak invariant. + +It turns out that-- I'm +previewing a bit here-- + +binary search +trees are obviously + +similar to heaps in the +sense that you visualize + +an array as a tree, +in the case of a heap. + +And binary search +trees are trees. + +But the invariant in a +min heap or a max heap, + +is this kind of +a week invariant. + +It essentially says, +look at the min element. + +And the min element +has to be the root, + +so you can do that one +operation pretty quickly. + +But if you want to look +for a k minute check, + +you want to see if there's +an element in the heap that + +is less than or equal to k, +or greater than or equal to k + +from t, this is going +to take order n time. + +OK? + +Good. + +And finally, we haven't +talked about dictionaries, + +but we will next week. + +Eric will talk about hash +tables and dictionaries. + +And they have the same problem. + +So it's not like dictionaries +are going to solve the problem, + +for those of you who know about +hash tables and dictionaries. + +But you'll hear about +them in some detail. + +They're very good +at other things. + +So I don't want to say much more +about that, because you're not + +supposed to know +about dictionaries. + +Or at least we +don't want to assume + +you do, though we +have talked about them + +and alluded to +dictionaries earlier. + +And so that's a story here. + +Yeah, back there, question. + +AUDIENCE: Yeah, can you explain +why it's [INAUDIBLE] time? + +PROFESSOR: So what +is a heap, right? + +A heap essentially-- a +min heap, for example, + +or we talked about +max heaps last time, + +has the property that +you have an element k, + +and you're going to look +at, let's say it's 21. + +Let's do min heaps, so this +has to be less than what's + +here, 23, and what +there, maybe it's + +30, and so on and so forth. + +And you have a +recursive definition. + +And when you insert into a min +heap, typically what happens + +is suppose you wanted to +insert, for argument's sake, + +I want to insert 25. + +I want to insert 25 into this. + +The insertion algorithm +for a min heap + +typically adds to the +end of the min heap. + +So what you do is you +would add 25 to this. + +And let's say that you +had something out here. + +So you'd add to it. + +And you'd start flipping things. + +And you could work with +just this part of the array + +to insert 25 in here. + +And you'd be able to satisfy +the invariant of the min heap. + +And you'd get a +legitimate min heap. + +But you'd never check the +left part of it, which is 23. + +So it's quite possible-- +and this is a good example-- + +that your basic insertion +algorithm, which is essentially + +a version of max heap +of i, or min heap of i, + +would simply insert +at the end, and keep + +flipping until you get +the min heap property, + +would be unable to check +for the k minute check + +during the insertion. + +But what you'd have to do +is to go look elsewhere. + +That min heap of i +we'd never look at-- + +or the insert algorithm we'd +never look at-- and that + +would require order n time. + +All right? + +AUDIENCE: Thank you. + +PROFESSOR: So that's the +story for the min heap. + +Thanks for the question. + +And it's similar for +dictionaries, as I said. + +And so we're stuck. + +We have no data structure yet +that can do all of the things + +that I put up on the board to +the left, in order log n time. + +And as you can see, the +sorted array got pretty close. + +And so if you could +just solve this problem, + +if you could do fast insertion-- +and by fast I mean order log n + +time-- into a sorted +array, we'd be in business. + +So that's what we'd like to +do with binary search trees. + +Binary search trees +are, as you can imagine, + +enable binary search. + +But the sorted arrays +don't allow fast insertion, + +but BSTs do. + +So let me introduce BSTs. + +As with any data +structure, there's + +a nice invariant +associated with BSTs. + +The invariant is stronger +than the heap invariant. + +And actually, that makes them +a different data structure, not + +necessarily a better +data structure. + +And I'll say why, but different. + +For this problem they're better. + +So one example of a binary +search tree looks like this. + +And as a binary tree you have +a node, and we call it x. + +Each of the nodes +has a key of x. + +So 30 is the key for this node, +17 for that one, et cetera. + +Unlike in a heap, +your data structure + +is a little more complicated. + +The heap is simply +an array, and you + +happen to visualize +it as a tree. + +The binary search +tree is actually + +a tree that has +pointers, unlike a heap. + +So it's a more complicated +data structure. + +You need a few more bytes for +every node of the binary search + +tree, as opposed +to the heap, which + +is simply an array element. + +And the pointers +are parent of x. + +I haven't bothered +showing the arrows here, + +because you could be going +upwards or backwards. + +And you could imagine +that you actually + +have a parent pointer +that goes up this way, + +and you have a child +pointer that goes this way. + +So there's really, +potentially, three pointers + +for each node, the +parent, the left child, + +and the right child. + +So pretty straightforward. + +That's the data +structure in terms + +of what it needs to have +so you can operate on it. + +And there's an +invariant for a BST. + +What makes a BST +is that you have + +an ordering of the +key values that + +satisfy the invariant that +for all nodes x if y is + +in the left subtree +of x, we have-- + +if it's in the left +subtree then key of y + +is less than or +equal to key of x. + +And if y is in the +right subtree we + +have key of y is greater +than or equal to key of x. + +So if we're talking +about trees here, + +subtrees here, +everything underneath-- + +and that's the stronger part +of the invariant in the BST, + +versus in the heap we were just +talking about the children. + +And so you look at +this BST, it is a BST + +because if I look to +the right, from the root + +I only see values that +are greater than 30. + +And if I look to the left, +in the entire subtree, + +all the way down I only see +values that are less than 30. + +And that has to be true for any +intermediate node in the tree. + +And the only other +nontrivial node here is 17. + +And you see that 14 is less than +17, and 20 is greater than 17. + +OK? + +So that's the BST. + +That's the data structure. + +This is the invariant. + +So let's look at why BSTs +are a possibility for solving + +our runway reservation problem. + +And what I'll do is +I'll do the insert. + +So let's start with the +nil set of elements, + +or null set of elements, R. +And let's start inserting. + +So I insert 49. + +And all I do is make a node +that has a key value of 49. + +This one is easy. + +Next insert, 79. + +And what happens here +is I have to look at 49, + +and I compare 79 to 49. + +And because 79 is greater +than 49 I go to the right + +and I attach 79 to +the right child of 49. + +Then I want to insert 46. + +And when I want to +insert 46 I look at this, + +I compare 49 and 46. + +46 is less, so I go to the left +side and I put 46 in there. + +Next, let's say I +want to insert 41. + +So far I haven't really talked +about the k minute checks. + +And you could imagine +that they're being done. + +I'll show you exactly, or +talk about exactly how they're + +done in a second. + +It's not that hard. + +But let me go ahead +and do one more. + +For 41, 41 is less +than 49, so I go left. + +41 is less than 46, so +I go left and attach it + +to the left child. + +All right? + +So that's what I have right now. + +Now let's talk about +the k minute check. + +It's good to talk about +the K minute check + +when there's +actually a violation. + +And let's assume +the k equals 3 here. + +And so, same thing here. + +You're essentially doing +binary search here. + +And you're doing the checks as +you're doing the binary search. + +So what you're +going to be doing is + +you're going to check that-- +you're going to compare 42 + +with 49, with the +k minute check. + +And you realize they're 7 apart. + +So that's OK. + +And 42 is less than +49, so you go left. + +And then you compare 42 with 46. + +And again, it's less than 46, +but it's k away, more than 3 + +away from 46. + +So that's cool. + +And you go left. + +And then you get to 41. + +And you compare 42 with 41. + +In this case is greater. + +But it's not k more than it. + +And so that means that if +you didn't have the check, + +you would be putting 42 in here. + +But because you have +the check, you fail. + +And you say, look, +I mean this violates + +the safety property, violates +the check I need to do. + +And therefore I'm +not going to insert-- + +I'm not going to reserve +a request for you. + +All right? + +So what's happened here is +it's basically a sorted array, + +except that you added +a bunch of pointers + +associated with the tree. + +And so it's somewhere between a +sorted list and a sorted array. + +And it does exactly +the right thing + +with respect to +being able to insert. + +Once you've found +the place to insert, + +it's merely attaching +this particular new node + +with it's appropriate +key to the pointer. + +All right? + +So what's happened +here is that if h + +is the height of the +tree then insertion + +with or without the check +is done in order h time. + +And that's what +BSTs are good for. + +People buy that? + +Any questions about how they +k minute check proceeded? + +Yeah, question. + +AUDIENCE: So, what's it called? + +The what check? + +PROFESSOR: The k minute check. + +Sorry, the k was 3 minutes k. + +I had this thing over +here, add t to the set R + +if no other landings are +scheduled within k minutes. + +So k was just a number. + +I want it to be a +parameter because it + +doesn't matter what k is. + +As long as you know what it is +when you do the binary search, + +you can add that in to an +argument to your insert, + +and do the check. + +AUDIENCE: OK. + +PROFESSOR: So in this case, +I set k to be 3 out here. + +And I was doing a check +to see that the invariant, + +any elements in the BST +already, on any nodes that + +had keys that were +within 3 minutes-- + +because I fixed k to be +3-- to the actual time + +that I was trying to insert. + +All right? + +AUDIENCE: So there's +no way [INAUDIBLE]. + +PROFESSOR: I'm sorry, +there's no way? + +AUDIENCE: There's +no way you could + +insert the 42 into +the tree then? + +PROFESSOR: Well, if +the basic insertion + +method into a binary search tree +doesn't have any constraints. + +But you can certainly +augment the insertion method + +without changing the efficiency +of the insertion method. + +So let's say that +all you wanted to do + +was insert into a +binary search tree, + +and it had nothing to do +with the runway reservation. + +Then you would just insert +the way I described to you. + +The beauty of the +binary search tree + +is that while you're +finding the place to insert, + +you can do these checks-- +the k minute checks. + +Yeah, question back there. + +AUDIENCE: What about 45? + +PROFESSOR: What about 45? + +So this is after-- we +haven't inserted 42 + +because it violated the check. + +So when you do 45, +then what happens + +is you see that +45 is less than 49 + +and you pass, because you're +more than 3 minutes away. + +We'll stick with that example. + +And then you get +here and then you + +see that 45 is less than 46, +and you'd fail right here. + +You would fail right here +if you were doing the check, + +because 45 is not +3 away from 46. + +All right? + +So that's the story. + +And so if you have h being +the height of the tree, + +as you can see you're +just following a path. + +And depending on +what the height is + +you're going to do +that many operations, + +times some constant factor. + +And so you can say that +this is order h time. + +All right? + +Any other questions? + +Yeah, question back there. + +AUDIENCE: In a normal +array [INAUDIBLE]. + +PROFESSOR: Well, it's up to you. + +In a conventional binary search +tree, or the vanilla binary + +search tree, typically +what you're doing + +is you're doing +either find or insert. + +And so what that means +is that you would just + +return the pointer +associated with that element. + +So if you're looking for find +46, for example, on the tree + +that I have out there, typically +46 is just the key value. + +And there may be a record +associated with it. + +And you would get a +pointer to that record + +because it's already in there. + +At that point you can +say I want to override. + +Or if you want, you could +have duplicate values. + +You could have this, +what's called a multiset. + +A multiset is a set that +has duplicate elements. + +In that case, you would need +a little more sophistication + +to differentiate between +two elements that + +have the same key values. + +So you'd have to +call it 46a and 46b. + +And you'd have to have some +way of differentiating. + +Any other questions? + +Yeah. + +AUDIENCE: Wouldn't +it be a problem + +if the tree's not balanced? + +PROFESSOR: Ah, great question. + +Yes, stay tuned. + +So I was careful, right? + +I guess I kind of +alluded to the fact + +that we'd solved the +runway reservation system. + +Did I actually say that +we'd solved the problem? + +Did I say we had +solved the problem? + +OK, so I did not lie. + +I did not lie. + +I said that the height +of the tree was h. + +And I said that this was +accomplished in order h time, + +right? + +Which is not quite what I want, +which is really your question. + +So we'll get to that. + +So we're not quite done yet. + +But before we do +that, it turns out + +that today's lecture is +really part one of two. + +You'll get a really good +sense of BST operations + +in today's lecture. + +But there's going to be a few +things that-- we can't cover + +all of double 6 in +the lecture, right? + +We'd like to, and let you +off for the entire fall, + +but that's not the way +it works, all right? + +So it's a great question. + +I'll answer it towards the end. + +I just wanted you +to say a little bit + +about other operations. + +There's many operations that +you can do on a binary search + +tree, that can be +done in order h time, + +and some even in constant time. + +And I'll put these in the notes. + +Some of these are +fairly straightforward. + +Find min can be done +in heap, in a min heap. + +If you want to find the minimum +value, it's constant time. + +You just return the root. + +In the case of a binary search +tree, how do you find the min? + +Someone? + +Worth a cushion. + +Yep. + +AUDIENCE: Keep +going to the left? + +PROFESSOR: Keep +going to the left. + +And how do you find the max? + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: Keep +going to the right. + +All right great, thank you. + +And finally, what +complexity is that? + +I sort gave it away, but I +want to hear it from you. + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: Hm? + +AUDIENCE: It's the height + +PROFESSOR: It's the +height, order h. + +All right, it's +order h complexity. + +Go to the left until +you hit a leaf, + +and until leaf +order h complexity. + +Same thing for max. + +And then you can do +a bunch of things. + +I'll put these in the notes. + +You can find things +like next larger + +x, which is the next +largest value beyond x. + +And you look at the key for +x and you say, for example, + +if you put 46 in there, what's +the next thing that's larger + +and that? + +In this tree here, it's 49. + +But that's something which was +trivially done in this example. + +But in general you can do +this in order h time as well. + +And you can see the pseudocode. + +And we'll probably cover +that in section tomorrow. + +What I want to do today, for the +rest of the time I have left, + +is actually talk about augmented +binary search trees, which + +are things that can do more +and have more data in them + +than just these pointers. + +And that's actually +something which + +should give you a sense of the +richness of the binary search + +tree structure, this +notion of augmentation. + +And those of you, again, +who have taken double 05, + +you know about +design amendments. + +And so specifications +never stay the same. + +I mean, you're +working for someone, + +and they never really +tell you what they want. + +They might, but they +change their mind. + +So in this case, we're +going to change our mind. + +And so we've done +this to the extent + +that we can cover all of +these in order h time. + +And let's say that now +the problem specification + +changed on us. + +There's an additional +requirement + +that we're asked to solve. + +And so you sort of +committed to BST structures. + +But now we have an +additional requirement. + +And the new requirement is that +we be able to compute rank t. + +And rank t is how +many planes are + +scheduled to land at times +less than or equal to t. + +So perfectly +reasonable question. + +It wasn't part of +the original spec. + +You now have built your +BST data structure, + +you thought you were done. + +Sorry, you aren't. + +You've got to do +this extra stuff. + +So that's the notion +of augmentation, + +which we're going to use this +is an example of how we're + +going to augment +the BST structure. + +And oh, by the way, +I don't want you + +to change the +complexity from order h. + +And we eventually will +get to order log n, + +but don't go change something +that was logarithmic to linear. + +That would be bad. + +So let's talk about +how you do this. + +And I don't think we +need this anymore. + +So the first thing we need to +do is add a little bit more + +information to the +node structure. + +And what we're going to do +is augment the BST structure. + +And we're going to add one +little number associated + +with each node, that looks at +the number of nodes below it. + +So in particular, +let's say that I + +have 49, 46, let's just +say 49, 46 for now. + +And over here I +have 79, 64, and 83. + +I'm going to modify-- +I'm going to have + +an extra number associated +with each of these nodes. + +And I'm just going +to write that number + +on the outside of the node. + +And you can just imagine +that now the key value has + +two numbers associated +with it-- the thing + +that I write inside the node, +and what I write outside of it. + +So in particular, when +I do insert or delete + +I'm going to be +modifying these numbers. + +And these are size numbers. + +And what do I mean by that? + +Well these numbers +correspond to subtree sizes. + +So the subtree size +here is 1, 1, 1. + +So as I'm building +this tree up I'm + +going to create an +augmented BST structure, + +and I've modified +insert and delete + +so they do some extra work. + +So let's say, for +argument's sake, + +that I've added this in +sort of a bottom up fashion. + +And what I have are these +particular subtree sizes. + +All of these should make sense. + +This has just a single +node, same thing here. + +So this subtree sizes associated +with these nodes are all 1. + +The subtree size +associated with 79 + +is 3, because you're +counting 79 and 64 and 83. + +And the subtree size +associated with 49 + +is 5, because you're counting +everything underneath it. + +How did we get these numbers? + +Well you want to +think about this + +as you started +with an empty set, + +and you kept inserting into it. + +And you were doing a sequence +of insert and delete operations. + +And if I explain to you how +an insert operation modifies + +these numbers, that is +pretty much all you need. + +And of course, analogously, +for a delete operation. + +So what would happen for, let's +say you wanted to insert 43? + +You would insert +43 at this point. + +And what you'd do is you +follow the insertion path + +just like you did before. + +But when you're +following that path + +you're going to increment the +nodes that you're seeing by 1. + +So you're going +to add 43 to this. + +And you'd add 5 plus +1, because you see 49. + +And then you would go +down and you'd see 46. + +And so you'd add 1 to that. + +And then finally, +you add 43 and you + +assign-- since +it's a leaf-- you'd + +assign to value corresponding +to the subtree size + +of this new node that you +put in there, to be 1. + +It guess a little, teensy +bit more complicated + +when you want to do +the k minute check. + +But from a complexity +standpoint, + +if you're not worried +about constant factors, + +you can just say, you know what? + +I'm going to first run +the regular insert, + +ignoring the subtree sizes. + +And if it fails, I'm done. + +Because I'm not going to +modify the BST, and I'm done. + +I'm not going to have to +modify the subtree sizes. + +If it succeeds, then +I'm going to go in, + +and I know now that I can +increment each of these nodes, + +because I know I'm +going to be successful. + +So that's sort of a trivial +way of solving this problem, + +that from an asymptotic +complexity standpoint + +gives you your order +h augmented insert. + +That make sense? + +Now you could do something +better than that. + +I mean, I would urge you, +if you had wrote something + +that-- we asked you to +write something like this, + +to create a single procedure +that essentially uses + +a recursion appropriately to +do the right thing in one pass + +through the BST. + +And we'll talk about +things like that + +as we go along in sections, +and possibly in lectures. + +So that's the subtree +insert delete. + +Everyone buy that? + +Yeah, question back there. + +AUDIENCE: If I wanted to delete +a number, like let's say 79-- + +PROFESSOR: Yep? + +AUDIENCE: --would we +have to take it out + +and then rewrite the entire BST? + +PROFESSOR: What you'd have to +do is a bubble up pointers. + +So you'd have to actually +have 64 connected to-- what + +will happen is 83 +would actually come up, + +and you would essentially +have some thing-- this + +is not quite how it works-- +but 83 would move up + +and you'd have 64 to the left. + +That's what would happened +for delete in this case. + +So you would have to move +pointers in the case of delete. + +And we're not done with +binary search tree operations + +from a standpoint of +teaching you about them. + +We'll talk about them not +just in today's lecture, + +but later as well. + +So there's one +thing missing here, + +though, which is I haven't +quite figured out-- + +I've told you how these +subtree sizes work. + +But it's not +completely clear, this + +is the last thing we have +to do, is how are you + +going to compute rank t +from the subtree sizes? + +So everyone understand +subtree sizes? + +It's just the number of nodes +that are underneath you. + +And you remember to count +yourself, all right? + +Now what is rank t? + +Rank t is how many +planes are scheduled + +to land at times less +than or equal to t. + +So now I have a BST structure +that looks like the one + +and I just ended up with. + +So I've added this 43. + +And so let me draw +that out here, + +and see if we can +answer this question. + +This is a subtle question. + +So I got 49, and that +subtree size is 6. + +I got 46, subtree size is 2. + +43, 79, 64. + +and 83. + +So what I want is +what lands before t? + +And how do I do that? + +Give me an algorithm +that would allow + +me to compute in order h time. + +I want to do this +in order h time. + +What lands before t? + +Someone? + +Yeah. + +AUDIENCE: So first +you would have + +to find where to insert +it, like we did before. + +PROFESSOR: Right, right. + +AUDIENCE: And then because we +have the order of whatever it + +was before-- not +the order, the-- + +PROFESSOR: The sizes? + +The sizes? + +Yeah. + +AUDIENCE: And then we can +look what's more than it + +on the right, we can +subtract it and we get-- + +PROFESSOR: What is more +than it on the right. + +Do you want to say-- + +AUDIENCE: Because, like-- + +PROFESSOR: OK. + +AUDIENCE: --on the right-- + +PROFESSOR: Right. + +AUDIENCE: --and then we +can take this minus this + +and we get what's left. + +PROFESSOR: That's +great, that's excellent. + +Excellent. + +So I'm going to do it a little +bit differently from what + +you described. + +I'm going to +actually do it in a, + +sort of, a more positive +way, no offense intended. + +What we're going to +do is we're going + +to add up the things +that we want to add up. + +And what you have +to do is walk-- + +your first step was right on. + +I mean, your answer is correct. + +I'm just going to do it +a little bit differently. + +You walk down the tree +to find the desired time. + +This is just your search. + +We know how to do that. + +As you walk down you +add in the nodes that + +is the subtree sizes-- you're +just adding in the notes here. + +So if you see-- depending +on the number of nodes + +that you see as you're +going deeper in, + +you want to add in the nodes. + +And you're going to add +one to that, corresponding + +to the nodes that are smaller. + +And we're going to add in the +subtree sizes to the left, + +as opposed to subtracting. + +That may not make +a lot of sense. + +But I guarantee you it +will once we do an example. + +So what's going on here? + +I want to find a +place to insert. + +I'm not actually going +to do the insert. + +Think of it is doing a lookup. + +And along the way, +I need to figure out + +the less than operator. + +I want to find all +of the things that + +are less than this +value I'm searching for. + +And so I have to do +a bit of arithmetic. + +So let's say that I'm +looking for what's + +less than or equal to 79. + +So t equals 79. + +So I'm going to look at 49. + +I'm going to walk down, +I'm going to look at 49. + +And because I say I'm +looking at 49-- and 49 + +is clearly less than 79. + +So I'm going to add 1. + +And that's this check over here. + +I move on and what I need to +do now is move to the right, + +because 79 is greater than 49. + +That's how my search would work. + +But because I've +moved to the right, + +I'm going to add the subtree +sizes that were to the left. + +Because I know that all +of the things to the left + +are clearly less than 79. + +So I'm going to add 2, +corresponding to a subtree 46. + +So I'm not actually +looking there. + +But I'm going to add +all of that stuff in. + +I'm going to move to the right, +and now I'm going to see 79. + +At this point 79 is less +than or equal to 79. + +So I'm going to see 79 +and I'm going to add 1. + +And because I've added 79, +just like I did with 49, + +I have to add the subtree +size to the left of 79. + +So the final addition +is I add 1 corresponding + +to the subtree 64. + +And at this point +I've discovered + +where I have to insert, I've +essentially found the location, + +it matches 79. + +And there was no modification +required in this algorithm. + +So if that was 78 you'd +essentially do the same things. + +But you're done because you +found the value, or the place + +that you want to insert. + +And you've done a +bunch of additions. + +And you go look at add 1, add +2, add 1, add 1, and you have 5. + +And that's the +correct answer, as you + +can see from this example. + +So what's the bad news? + +The bad news was what +this lady said up + +front, which was we haven't +quite solved the problem. + +Because sadly, I could +easily set things + +up such that the height h is +order n, h could be order n. + +And if, for example, I +gave you a sorted list, + +and I said insert into +binary search tree + +that's originally null 43, +and you put 43 in there. + +Then I say insert 46. + +And then I say instead of 48. + +And then I say +insert 49, et cetera. + +And, you know, these +could be any numbers. + +Then you see that what +does this look like? + +Does it look like a tree? + +It looks like a list. + +That's the bad news. + +And I'll let Eric give +you good news next week. + +We need to have this notion of +balanced binary search trees. + +So everything I've said is true. + +I did not lie. + +But the one extra +thing is we need + +to make sure these trees are +balanced so h is order log n. + +And then everything +I said works. + +All right? + +See you next time. \ No newline at end of file diff --git a/9NChLq-orAk.txt b/9NChLq-orAk.txt new file mode 100644 index 0000000000000000000000000000000000000000..eb35a93a882f7b24f46e548642789dd5874166a6 --- /dev/null +++ b/9NChLq-orAk.txt @@ -0,0 +1,307 @@ +align:start position:0% + +so ours is a little different + + align:start position:0% +so ours is a little different + + + align:start position:0% +so ours is a little different +well it was actually very different from + + align:start position:0% +well it was actually very different from + + + align:start position:0% +well it was actually very different from +everyone else because ours is in 2d and + + align:start position:0% +everyone else because ours is in 2d and + + + align:start position:0% +everyone else because ours is in 2d and +everyone else's is in 3d but so all we + + align:start position:0% +everyone else's is in 3d but so all we + + + align:start position:0% +everyone else's is in 3d but so all we +have basically is like a background and + + align:start position:0% +have basically is like a background and + + + align:start position:0% +have basically is like a background and +then you have like a canvas and and then + + align:start position:0% +then you have like a canvas and and then + + + align:start position:0% +then you have like a canvas and and then +what you can do is if I can find the + + align:start position:0% +what you can do is if I can find the + + + align:start position:0% +what you can do is if I can find the +mouse you can like paint on here for + + align:start position:0% +mouse you can like paint on here for + + + align:start position:0% +mouse you can like paint on here for +example and then if you click on eraser + + align:start position:0% +example and then if you click on eraser + + + align:start position:0% +example and then if you click on eraser +and then go over that you can erase it + + align:start position:0% +and then go over that you can erase it + + + align:start position:0% +and then go over that you can erase it +so the main part of this was supposed to + + align:start position:0% +so the main part of this was supposed to + + + align:start position:0% +so the main part of this was supposed to +be that it's supposed to be able to + + align:start position:0% +be that it's supposed to be able to + + + align:start position:0% +be that it's supposed to be able to +connect with the Kinect and if you for + + align:start position:0% +connect with the Kinect and if you for + + + align:start position:0% +connect with the Kinect and if you for +example you use your but your right hand + + align:start position:0% +example you use your but your right hand + + + align:start position:0% +example you use your but your right hand +to move the mouse and like they did and + + align:start position:0% +to move the mouse and like they did and + + + align:start position:0% +to move the mouse and like they did and +then put like if your left hand goes up + + align:start position:0% +then put like if your left hand goes up + + + align:start position:0% +then put like if your left hand goes up +it clicks and then it supposed to draw + + align:start position:0% +it clicks and then it supposed to draw + + + align:start position:0% +it clicks and then it supposed to draw +but the Kinect would just not connect + + align:start position:0% +but the Kinect would just not connect + + + align:start position:0% +but the Kinect would just not connect +with the thing at all for some reason so + + align:start position:0% +with the thing at all for some reason so + + + align:start position:0% +with the thing at all for some reason so +we couldn't it wouldn't detect motion so + + align:start position:0% +we couldn't it wouldn't detect motion so + + + align:start position:0% +we couldn't it wouldn't detect motion so +we couldn't get it to work but + + align:start position:0% +we couldn't get it to work but + + + align:start position:0% +we couldn't get it to work but +essentially what it does is if you were + + align:start position:0% +essentially what it does is if you were + + + align:start position:0% +essentially what it does is if you were +to see when it's just painting it's + + align:start position:0% +to see when it's just painting it's + + + align:start position:0% +to see when it's just painting it's +creating a dot right so what it's + + align:start position:0% +creating a dot right so what it's + + + align:start position:0% +creating a dot right so what it's +basically doing is every time you click + + align:start position:0% +basically doing is every time you click + + + align:start position:0% +basically doing is every time you click +it creates a dot and then if you do it + + align:start position:0% +it creates a dot and then if you do it + + + align:start position:0% +it creates a dot and then if you do it +like a fluid motion it creates a bunch + + align:start position:0% +like a fluid motion it creates a bunch + + + align:start position:0% +like a fluid motion it creates a bunch +of dots where for example if you were to + + align:start position:0% +of dots where for example if you were to + + + align:start position:0% +of dots where for example if you were to +like you know draw a lot it's yeah you + + align:start position:0% +like you know draw a lot it's yeah you + + + align:start position:0% +like you know draw a lot it's yeah you +see like the dots down here we were like + + align:start position:0% +see like the dots down here we were like + + + align:start position:0% +see like the dots down here we were like +gonna do colors but we couldn't get that + + align:start position:0% +gonna do colors but we couldn't get that + + + align:start position:0% +gonna do colors but we couldn't get that +far but that's like the recent project + + align:start position:0% +far but that's like the recent project + + + align:start position:0% +far but that's like the recent project +we were gonna have something where you + + align:start position:0% +we were gonna have something where you + + + align:start position:0% +we were gonna have something where you +could like change the the canvas and + + align:start position:0% +could like change the the canvas and + + + align:start position:0% +could like change the the canvas and +then you can change the background so it + + align:start position:0% +then you can change the background so it + + + align:start position:0% +then you can change the background so it +looks like you're painting it like at + + align:start position:0% +looks like you're painting it like at + + + align:start position:0% +looks like you're painting it like at +the beach or something like that and so + + align:start position:0% +the beach or something like that and so + + + align:start position:0% +the beach or something like that and so +you know ascetically pleasing because + + align:start position:0% +you know ascetically pleasing because + + + align:start position:0% +you know ascetically pleasing because +this is as far as we could get for now \ No newline at end of file diff --git a/9i1sOSIccgw.txt b/9i1sOSIccgw.txt new file mode 100644 index 0000000000000000000000000000000000000000..eec2d722806c647a511d8f8353d5653fd06057bb --- /dev/null +++ b/9i1sOSIccgw.txt @@ -0,0 +1,915 @@ +align:start position:0% + +the topic of this recitation is election + + align:start position:0% +the topic of this recitation is election + + + align:start position:0% +the topic of this recitation is election +forecasting which is the art and science + + align:start position:0% +forecasting which is the art and science + + + align:start position:0% +forecasting which is the art and science +of predicting the winner of an election + + align:start position:0% +of predicting the winner of an election + + + align:start position:0% +of predicting the winner of an election +before any votes are actually cast using + + align:start position:0% +before any votes are actually cast using + + + align:start position:0% +before any votes are actually cast using +polling data from likely voters in this + + align:start position:0% +polling data from likely voters in this + + + align:start position:0% +polling data from likely voters in this +recitation we are going to look at the + + align:start position:0% +recitation we are going to look at the + + + align:start position:0% +recitation we are going to look at the +United States presidential election in + + align:start position:0% +United States presidential election in + + + align:start position:0% +United States presidential election in +the United States a president is elected + + align:start position:0% +the United States a president is elected + + + align:start position:0% +the United States a president is elected +every four years and while there are a + + align:start position:0% +every four years and while there are a + + + align:start position:0% +every four years and while there are a +number of different political parties in + + align:start position:0% +number of different political parties in + + + align:start position:0% +number of different political parties in +the u.s. generally there are only two + + align:start position:0% +the u.s. generally there are only two + + + align:start position:0% +the u.s. generally there are only two +competitive candidates there's the + + align:start position:0% +competitive candidates there's the + + + align:start position:0% +competitive candidates there's the +Republican candidate who tends to be + + align:start position:0% +Republican candidate who tends to be + + + align:start position:0% +Republican candidate who tends to be +more conservative and the Democratic + + align:start position:0% +more conservative and the Democratic + + + align:start position:0% +more conservative and the Democratic +candidate who's more liberal so for + + align:start position:0% +candidate who's more liberal so for + + + align:start position:0% +candidate who's more liberal so for +instance a recent Republican president + + align:start position:0% +instance a recent Republican president + + + align:start position:0% +instance a recent Republican president +was george w bush and a recent + + align:start position:0% +was george w bush and a recent + + + align:start position:0% +was george w bush and a recent +Democratic president was Barack Obama + + align:start position:0% +Democratic president was Barack Obama + + + align:start position:0% +Democratic president was Barack Obama +now while in many countries the leader + + align:start position:0% +now while in many countries the leader + + + align:start position:0% +now while in many countries the leader +of the country is elected using you know + + align:start position:0% +of the country is elected using you know + + + align:start position:0% +of the country is elected using you know +the simple candidate who receives the + + align:start position:0% +the simple candidate who receives the + + + align:start position:0% +the simple candidate who receives the +largest number of votes across the + + align:start position:0% +largest number of votes across the + + + align:start position:0% +largest number of votes across the +entire country is elected in the United + + align:start position:0% +entire country is elected in the United + + + align:start position:0% +entire country is elected in the United +States it's significantly more + + align:start position:0% +States it's significantly more + + + align:start position:0% +States it's significantly more +complicated there are 50 states in the + + align:start position:0% +complicated there are 50 states in the + + + align:start position:0% +complicated there are 50 states in the +United States and each is assigned a + + align:start position:0% +United States and each is assigned a + + + align:start position:0% +United States and each is assigned a +number of electoral votes based on its + + align:start position:0% +number of electoral votes based on its + + + align:start position:0% +number of electoral votes based on its +population so for instance the most + + align:start position:0% +population so for instance the most + + + align:start position:0% +population so for instance the most +populous state California in 2012 had + + align:start position:0% +populous state California in 2012 had + + + align:start position:0% +populous state California in 2012 had +nearly twenty times the number of + + align:start position:0% +nearly twenty times the number of + + + align:start position:0% +nearly twenty times the number of +electoral votes as the least populous + + align:start position:0% +electoral votes as the least populous + + + align:start position:0% +electoral votes as the least populous +states and these number of electoral + + align:start position:0% +states and these number of electoral + + + align:start position:0% +states and these number of electoral +votes are reassigned periodically based + + align:start position:0% +votes are reassigned periodically based + + + align:start position:0% +votes are reassigned periodically based +on changes of populations between states + + align:start position:0% +on changes of populations between states + + + align:start position:0% +on changes of populations between states +within a given state in general the + + align:start position:0% +within a given state in general the + + + align:start position:0% +within a given state in general the +system is winner-take-all in the sense + + align:start position:0% +system is winner-take-all in the sense + + + align:start position:0% +system is winner-take-all in the sense +that the candidate who receives the most + + align:start position:0% +that the candidate who receives the most + + + align:start position:0% +that the candidate who receives the most +votes in the state gets all of its + + align:start position:0% +votes in the state gets all of its + + + align:start position:0% +votes in the state gets all of its +electoral votes and then across the + + align:start position:0% +electoral votes and then across the + + + align:start position:0% +electoral votes and then across the +entire country the candidate who + + align:start position:0% +entire country the candidate who + + + align:start position:0% +entire country the candidate who +receives the most electoral votes wins + + align:start position:0% +receives the most electoral votes wins + + + align:start position:0% +receives the most electoral votes wins +the entire presidential election now + + align:start position:0% +the entire presidential election now + + + align:start position:0% +the entire presidential election now +while it seems like a somewhat subtle + + align:start position:0% +while it seems like a somewhat subtle + + + align:start position:0% +while it seems like a somewhat subtle +distinction the Electoral College versus + + align:start position:0% +distinction the Electoral College versus + + + align:start position:0% +distinction the Electoral College versus +the the simple popular vote model it can + + align:start position:0% +the the simple popular vote model it can + + + align:start position:0% +the the simple popular vote model it can +have very significant consequences on + + align:start position:0% +have very significant consequences on + + + align:start position:0% +have very significant consequences on +the outcome of the election as an + + align:start position:0% +the outcome of the election as an + + + align:start position:0% +the outcome of the election as an +example let's look at the 2000 + + align:start position:0% +example let's look at the 2000 + + + align:start position:0% +example let's look at the 2000 +presidential election between George W + + align:start position:0% +presidential election between George W + + + align:start position:0% +presidential election between George W +Bush and Al Gore as we can see on the + + align:start position:0% +Bush and Al Gore as we can see on the + + + align:start position:0% +Bush and Al Gore as we can see on the +right here Al Gore received more than + + align:start position:0% +right here Al Gore received more than + + + align:start position:0% +right here Al Gore received more than +500,000 more votes across the entire + + align:start position:0% +500,000 more votes across the entire + + + align:start position:0% +500,000 more votes across the entire +country than george w bush in terms of + + align:start position:0% +country than george w bush in terms of + + + align:start position:0% +country than george w bush in terms of +the popular vote but in terms of the + + align:start position:0% +the popular vote but in terms of the + + + align:start position:0% +the popular vote but in terms of the +electoral vote because of how those + + align:start position:0% +electoral vote because of how those + + + align:start position:0% +electoral vote because of how those +votes were distributed George Bush + + align:start position:0% +votes were distributed George Bush + + + align:start position:0% +votes were distributed George Bush +actually won the election because he + + align:start position:0% +actually won the election because he + + + align:start position:0% +actually won the election because he +received five more elect + + align:start position:0% +received five more elect + + + align:start position:0% +received five more elect +votes than Al Gore so our goal will be + + align:start position:0% +votes than Al Gore so our goal will be + + + align:start position:0% +votes than Al Gore so our goal will be +to use polling data that's collected + + align:start position:0% +to use polling data that's collected + + + align:start position:0% +to use polling data that's collected +from likely voters before the election + + align:start position:0% +from likely voters before the election + + + align:start position:0% +from likely voters before the election +to predict the winner in each state and + + align:start position:0% +to predict the winner in each state and + + + align:start position:0% +to predict the winner in each state and +therefore to enable us to predict the + + align:start position:0% +therefore to enable us to predict the + + + align:start position:0% +therefore to enable us to predict the +winner of the entire election in the + + align:start position:0% +winner of the entire election in the + + + align:start position:0% +winner of the entire election in the +electoral college system + + align:start position:0% +electoral college system + + + align:start position:0% +electoral college system +why election prediction has long + + align:start position:0% +why election prediction has long + + + align:start position:0% +why election prediction has long +attracted some attention there's been a + + align:start position:0% +attracted some attention there's been a + + + align:start position:0% +attracted some attention there's been a +particular interest in the problem for + + align:start position:0% +particular interest in the problem for + + + align:start position:0% +particular interest in the problem for +the 2012 presidential election when then + + align:start position:0% +the 2012 presidential election when then + + + align:start position:0% +the 2012 presidential election when then +New York Times columnist Nate Silver + + align:start position:0% +New York Times columnist Nate Silver + + + align:start position:0% +New York Times columnist Nate Silver +took on the task of predicting the + + align:start position:0% +took on the task of predicting the + + + align:start position:0% +took on the task of predicting the +winner in each state to carry out this + + align:start position:0% +winner in each state to carry out this + + + align:start position:0% +winner in each state to carry out this +prediction task we're gonna use some + + align:start position:0% +prediction task we're gonna use some + + + align:start position:0% +prediction task we're gonna use some +data from Real Clear Politics calm that + + align:start position:0% +data from Real Clear Politics calm that + + + align:start position:0% +data from Real Clear Politics calm that +basically represents polling data that + + align:start position:0% +basically represents polling data that + + + align:start position:0% +basically represents polling data that +was collected in the months leading up + + align:start position:0% +was collected in the months leading up + + + align:start position:0% +was collected in the months leading up +to the 2004 2008 and 2012 US + + align:start position:0% +to the 2004 2008 and 2012 US + + + align:start position:0% +to the 2004 2008 and 2012 US +presidential elections each row in the + + align:start position:0% +presidential elections each row in the + + + align:start position:0% +presidential elections each row in the +dataset represents a state in a + + align:start position:0% +dataset represents a state in a + + + align:start position:0% +dataset represents a state in a +particular election year and the + + align:start position:0% +particular election year and the + + + align:start position:0% +particular election year and the +dependent variable which is called + + align:start position:0% +dependent variable which is called + + + align:start position:0% +dependent variable which is called +Republican is a binary outcome it's one + + align:start position:0% +Republican is a binary outcome it's one + + + align:start position:0% +Republican is a binary outcome it's one +if the Republican won that state in that + + align:start position:0% +if the Republican won that state in that + + + align:start position:0% +if the Republican won that state in that +particular election year and is zero if + + align:start position:0% +particular election year and is zero if + + + align:start position:0% +particular election year and is zero if +a Democrat won the independent variables + + align:start position:0% +a Democrat won the independent variables + + + align:start position:0% +a Democrat won the independent variables +again are related to polling data in + + align:start position:0% +again are related to polling data in + + + align:start position:0% +again are related to polling data in +that state so for instance the Rasmussen + + align:start position:0% +that state so for instance the Rasmussen + + + align:start position:0% +that state so for instance the Rasmussen +and survey u-s-a variables are related + + align:start position:0% +and survey u-s-a variables are related + + + align:start position:0% +and survey u-s-a variables are related +to two major polls that are that are + + align:start position:0% +to two major polls that are that are + + + align:start position:0% +to two major polls that are that are +assigned across many different states in + + align:start position:0% +assigned across many different states in + + + align:start position:0% +assigned across many different states in +the United States and it represents the + + align:start position:0% +the United States and it represents the + + + align:start position:0% +the United States and it represents the +percentage of voters who said they were + + align:start position:0% +percentage of voters who said they were + + + align:start position:0% +percentage of voters who said they were +likely to vote Republican - the + + align:start position:0% +likely to vote Republican - the + + + align:start position:0% +likely to vote Republican - the +percentage who said they were likely to + + align:start position:0% +percentage who said they were likely to + + + align:start position:0% +percentage who said they were likely to +vote Democrats so for instance if the + + align:start position:0% +vote Democrats so for instance if the + + + align:start position:0% +vote Democrats so for instance if the +variable survey u-s-a in our data set + + align:start position:0% +variable survey u-s-a in our data set + + + align:start position:0% +variable survey u-s-a in our data set +has value negative six it means that six + + align:start position:0% +has value negative six it means that six + + + align:start position:0% +has value negative six it means that six +percent more voters said they were + + align:start position:0% +percent more voters said they were + + + align:start position:0% +percent more voters said they were +likely to vote Democrat then said they + + align:start position:0% +likely to vote Democrat then said they + + + align:start position:0% +likely to vote Democrat then said they +were likely to vote Republican in that + + align:start position:0% +were likely to vote Republican in that + + + align:start position:0% +were likely to vote Republican in that +state we have two additional variables + + align:start position:0% +state we have two additional variables + + + align:start position:0% +state we have two additional variables +that capture polling data from a wider + + align:start position:0% +that capture polling data from a wider + + + align:start position:0% +that capture polling data from a wider +range of polls or as mucin and survey + + align:start position:0% +range of polls or as mucin and survey + + + align:start position:0% +range of polls or as mucin and survey +u-s-a are definitely not the only polls + + align:start position:0% +u-s-a are definitely not the only polls + + + align:start position:0% +u-s-a are definitely not the only polls +that are run on a state-by-state basis + + align:start position:0% +that are run on a state-by-state basis + + + align:start position:0% +that are run on a state-by-state basis +diff count counts the number of all the + + align:start position:0% +diff count counts the number of all the + + + align:start position:0% +diff count counts the number of all the +polls leading up to the election that + + align:start position:0% +polls leading up to the election that + + + align:start position:0% +polls leading up to the election that +predicted a Republican winner in the + + align:start position:0% +predicted a Republican winner in the + + + align:start position:0% +predicted a Republican winner in the +state - the number of poles that + + align:start position:0% +state - the number of poles that + + + align:start position:0% +state - the number of poles that +predicted a Democratic winner and prop R + + align:start position:0% +predicted a Democratic winner and prop R + + + align:start position:0% +predicted a Democratic winner and prop R +or proportion Republican Perez the + + align:start position:0% +or proportion Republican Perez the + + + align:start position:0% +or proportion Republican Perez the +proportion of all those polls leading up + + align:start position:0% +proportion of all those polls leading up + + + align:start position:0% +proportion of all those polls leading up +to the election that predicted a + + align:start position:0% +to the election that predicted a + + + align:start position:0% +to the election that predicted a +Republican winner + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/AvvUQjoqOUU.txt b/AvvUQjoqOUU.txt new file mode 100644 index 0000000000000000000000000000000000000000..d34d89bc7dbf1408ac66339995ecdfebf31cda48 --- /dev/null +++ b/AvvUQjoqOUU.txt @@ -0,0 +1,15939 @@ +align:start position:0% + +um okay anyway so online market so what + + align:start position:0% +um okay anyway so online market so what + + + align:start position:0% +um okay anyway so online market so what +I you know I've got uh several different + + align:start position:0% +I you know I've got uh several different + + + align:start position:0% +I you know I've got uh several different +papers to I was I figured I'd talk about + + align:start position:0% +papers to I was I figured I'd talk about + + + align:start position:0% +papers to I was I figured I'd talk about +today all of them are talking about uh + + align:start position:0% +today all of them are talking about uh + + + align:start position:0% +today all of them are talking about uh +online retail in one form or another um + + align:start position:0% +online retail in one form or another um + + + align:start position:0% +online retail in one form or another um +and and um just different issues in + + align:start position:0% +and and um just different issues in + + + align:start position:0% +and and um just different issues in +different issues in online retail trying + + align:start position:0% +different issues in online retail trying + + + align:start position:0% +different issues in online retail trying +to understand the industry um so the + + align:start position:0% +to understand the industry um so the + + + align:start position:0% +to understand the industry um so the +first uh paper I was going to talk about + + align:start position:0% +first uh paper I was going to talk about + + + align:start position:0% +first uh paper I was going to talk about +inov kler 11 C learning from seller + + align:start position:0% +inov kler 11 C learning from seller + + + align:start position:0% +inov kler 11 C learning from seller +experiments online markets um this is a + + align:start position:0% +experiments online markets um this is a + + + align:start position:0% +experiments online markets um this is a +paper uh studying + + align:start position:0% +paper uh studying + + + align:start position:0% +paper uh studying +eBay uh and you know while sort of eBay + + align:start position:0% +eBay uh and you know while sort of eBay + + + align:start position:0% +eBay uh and you know while sort of eBay +has been in a long run decline uh you + + align:start position:0% +has been in a long run decline uh you + + + align:start position:0% +has been in a long run decline uh you +know it's still an important way in + + align:start position:0% +know it's still an important way in + + + align:start position:0% +know it's still an important way in +which things get sold and I also just + + align:start position:0% +which things get sold and I also just + + + align:start position:0% +which things get sold and I also just +wanted to cover it because of the sort + + align:start position:0% +wanted to cover it because of the sort + + + align:start position:0% +wanted to cover it because of the sort +of + + align:start position:0% +of + + + align:start position:0% +of +um thought the method the methodology of + + align:start position:0% +um thought the method the methodology of + + + align:start position:0% +um thought the method the methodology of +the paper is interesting as an as a way + + align:start position:0% +the paper is interesting as an as a way + + + align:start position:0% +the paper is interesting as an as a way +to attack problems and these idea is + + align:start position:0% +to attack problems and these idea is + + + align:start position:0% +to attack problems and these idea is +that what they're sort of talking about + + align:start position:0% +that what they're sort of talking about + + + align:start position:0% +that what they're sort of talking about +is an alternative to sort of doing field + + align:start position:0% +is an alternative to sort of doing field + + + align:start position:0% +is an alternative to sort of doing field +experiments or setting up agreements to + + align:start position:0% +experiments or setting up agreements to + + + align:start position:0% +experiments or setting up agreements to +run experiments with online service + + align:start position:0% +run experiments with online service + + + align:start position:0% +run experiments with online service +providers is what they call + + align:start position:0% +providers is what they call + + + align:start position:0% +providers is what they call +opportunistic experiments you just find + + align:start position:0% +opportunistic experiments you just find + + + align:start position:0% +opportunistic experiments you just find +you know there are many many businesses + + align:start position:0% +you know there are many many businesses + + + align:start position:0% +you know there are many many businesses +in this world those businesses are + + align:start position:0% +in this world those businesses are + + + align:start position:0% +in this world those businesses are +trying to operate optimally they run + + align:start position:0% +trying to operate optimally they run + + + align:start position:0% +trying to operate optimally they run +lots of experiments themselves and so + + align:start position:0% +lots of experiments themselves and so + + + align:start position:0% +lots of experiments themselves and so +their idea is to take advantage of all + + align:start position:0% +their idea is to take advantage of all + + + align:start position:0% +their idea is to take advantage of all +these experiments that sellers are + + align:start position:0% +these experiments that sellers are + + + align:start position:0% +these experiments that sellers are +running on eBay and and analyze those + + align:start position:0% +running on eBay and and analyze those + + + align:start position:0% +running on eBay and and analyze those +and obviously you know you get less + + align:start position:0% +and obviously you know you get less + + + align:start position:0% +and obviously you know you get less +controlled experiments than if you were + + align:start position:0% +controlled experiments than if you were + + + align:start position:0% +controlled experiments than if you were +setting up the experiment yourself each + + align:start position:0% +setting up the experiment yourself each + + + align:start position:0% +setting up the experiment yourself each +experiment is not ideal but you know + + align:start position:0% +experiment is not ideal but you know + + + align:start position:0% +experiment is not ideal but you know +there has thousands and thousands of not + + align:start position:0% +there has thousands and thousands of not + + + align:start position:0% +there has thousands and thousands of not +ideal experiments maybe more informative + + align:start position:0% +ideal experiments maybe more informative + + + align:start position:0% +ideal experiments maybe more informative +than + + align:start position:0% +than + + + align:start position:0% +than +one or more informative and cheaper to + + align:start position:0% +one or more informative and cheaper to + + + align:start position:0% +one or more informative and cheaper to +run than just sort of one experiment you + + align:start position:0% +run than just sort of one experiment you + + + align:start position:0% +run than just sort of one experiment you +design yourself um so to start with a + + align:start position:0% +design yourself um so to start with a + + + align:start position:0% +design yourself um so to start with a +note that you know very few things on + + align:start position:0% +note that you know very few things on + + + align:start position:0% +note that you know very few things on +eBay are actually unique um they said + + align:start position:0% +eBay are actually unique um they said + + + align:start position:0% +eBay are actually unique um they said +you know it's a I guess interesting fact + + align:start position:0% +you know it's a I guess interesting fact + + + align:start position:0% +you know it's a I guess interesting fact +about eBay um for about a half of the + + align:start position:0% +about eBay um for about a half of the + + + align:start position:0% +about eBay um for about a half of the +items that are sold on eBay you can find + + align:start position:0% +items that are sold on eBay you can find + + + align:start position:0% +items that are sold on eBay you can find +a nearly identical item sold by exactly + + align:start position:0% +a nearly identical item sold by exactly + + + align:start position:0% +a nearly identical item sold by exactly +the same + + align:start position:0% +the same + + + align:start position:0% +the same +seller and so when they're talking about + + align:start position:0% +seller and so when they're talking about + + + align:start position:0% +seller and so when they're talking about +an experiment they experiment meaning + + align:start position:0% +an experiment they experiment meaning + + + align:start position:0% +an experiment they experiment meaning +you have a seller you have exactly the + + align:start position:0% +you have a seller you have exactly the + + + align:start position:0% +you have a seller you have exactly the +same seller selling a product with + + align:start position:0% +same seller selling a product with + + + align:start position:0% +same seller selling a product with +exactly the same listing title listed in + + align:start position:0% +exactly the same listing title listed in + + + align:start position:0% +exactly the same listing title listed in +the same category and subtitle and they + + align:start position:0% +the same category and subtitle and they + + + align:start position:0% +the same category and subtitle and they +find 55 million seller experiments + + align:start position:0% +find 55 million seller experiments + + + align:start position:0% +find 55 million seller experiments +involving a total of 350 million + + align:start position:0% +involving a total of 350 million + + + align:start position:0% +involving a total of 350 million +listings um for much of their uh + + align:start position:0% +listings um for much of their uh + + + align:start position:0% +listings um for much of their uh +analysis they're restricting attention + + align:start position:0% +analysis they're restricting attention + + + align:start position:0% +analysis they're restricting attention +to experiments that have several + + align:start position:0% +to experiments that have several + + + align:start position:0% +to experiments that have several +different features there at least two + + align:start position:0% +different features there at least two + + + align:start position:0% +different features there at least two +items auctioned there's also at least + + align:start position:0% +items auctioned there's also at least + + + align:start position:0% +items auctioned there's also at least +one successful posted price sale they + + align:start position:0% +one successful posted price sale they + + + align:start position:0% +one successful posted price sale they +want a posted price sale because they're + + align:start position:0% +want a posted price sale because they're + + + align:start position:0% +want a posted price sale because they're +going to use that as sort of a reference + + align:start position:0% +going to use that as sort of a reference + + + align:start position:0% +going to use that as sort of a reference +for what's the market price of this if + + align:start position:0% +for what's the market price of this if + + + align:start position:0% +for what's the market price of this if +you just sell it so uh on on not through + + align:start position:0% +you just sell it so uh on on not through + + + align:start position:0% +you just sell it so uh on on not through +an auction and even with those + + align:start position:0% +an auction and even with those + + + align:start position:0% +an auction and even with those +restrictions they come up with you know + + align:start position:0% +restrictions they come up with you know + + + align:start position:0% +restrictions they come up with you know +244,000 experiments that have 7.6 + + align:start position:0% +244,000 experiments that have 7.6 + + + align:start position:0% +244,000 experiments that have 7.6 +million listings so the idea is just + + align:start position:0% +million listings so the idea is just + + + align:start position:0% +million listings so the idea is just +that eBay sellers are just experimenting + + align:start position:0% +that eBay sellers are just experimenting + + + align:start position:0% +that eBay sellers are just experimenting +all the time with all kinds of things + + align:start position:0% +all the time with all kinds of things + + + align:start position:0% +all the time with all kinds of things +and this is something we can take + + align:start position:0% +and this is something we can take + + + align:start position:0% +and this is something we can take +advantage of the paper itself has like + + align:start position:0% +advantage of the paper itself has like + + + align:start position:0% +advantage of the paper itself has like +multiple different subp + + align:start position:0% +multiple different subp + + + align:start position:0% +multiple different subp +papers um discussing what to do with + + align:start position:0% +papers um discussing what to do with + + + align:start position:0% +papers um discussing what to do with +this so uh one of the subp papers is how + + align:start position:0% +this so uh one of the subp papers is how + + + align:start position:0% +this so uh one of the subp papers is how +to buy it now prices affect out comes + + align:start position:0% +to buy it now prices affect out comes + + + align:start position:0% +to buy it now prices affect out comes +you know on eBay if you have't never + + align:start position:0% +you know on eBay if you have't never + + + align:start position:0% +you know on eBay if you have't never +been on an eBay auction it's like it's + + align:start position:0% +been on an eBay auction it's like it's + + + align:start position:0% +been on an eBay auction it's like it's +classic English ascending bid auction uh + + align:start position:0% +classic English ascending bid auction uh + + + align:start position:0% +classic English ascending bid auction uh +but there's also this option of just + + align:start position:0% +but there's also this option of just + + + align:start position:0% +but there's also this option of just +click here to buy it for $125 and end + + align:start position:0% +click here to buy it for $125 and end + + + align:start position:0% +click here to buy it for $125 and end +the auction and so one of the papers + + align:start position:0% +the auction and so one of the papers + + + align:start position:0% +the auction and so one of the papers +they do is how does having a buy now + + align:start position:0% +they do is how does having a buy now + + + align:start position:0% +they do is how does having a buy now +price affect the outcome uh second is + + align:start position:0% +price affect the outcome uh second is + + + align:start position:0% +price affect the outcome uh second is +how does shipping fees affect outcomes + + align:start position:0% +how does shipping fees affect outcomes + + + align:start position:0% +how does shipping fees affect outcomes +there's this um you know interesting + + align:start position:0% +there's this um you know interesting + + + align:start position:0% +there's this um you know interesting +earlier paper by Hussein and Morgan that + + align:start position:0% +earlier paper by Hussein and Morgan that + + + align:start position:0% +earlier paper by Hussein and Morgan that +argued that um you know consumers are + + align:start position:0% +argued that um you know consumers are + + + align:start position:0% +argued that um you know consumers are +fairly naive in dealing with shipping + + align:start position:0% +fairly naive in dealing with shipping + + + align:start position:0% +fairly naive in dealing with shipping +fees and that you make more money by + + align:start position:0% +fees and that you make more money by + + + align:start position:0% +fees and that you make more money by +having good with 9.95 shipping than good + + align:start position:0% +having good with 9.95 shipping than good + + + align:start position:0% +having good with 9.95 shipping than good +with 595 shipping just you know somehow + + align:start position:0% +with 595 shipping just you know somehow + + + align:start position:0% +with 595 shipping just you know somehow +you offer the same good different + + align:start position:0% +you offer the same good different + + + align:start position:0% +you offer the same good different +shipping prices people somehow focus on + + align:start position:0% +shipping prices people somehow focus on + + + align:start position:0% +shipping prices people somehow focus on +the item price not on the shipping price + + align:start position:0% +the item price not on the shipping price + + + align:start position:0% +the item price not on the shipping price +and so the p shpp and handling you make + + align:start position:0% +and so the p shpp and handling you make + + + align:start position:0% +and so the p shpp and handling you make +more money selling with a high shipping + + align:start position:0% +more money selling with a high shipping + + + align:start position:0% +more money selling with a high shipping +and handling fee um anyway they're going + + align:start position:0% +and handling fee um anyway they're going + + + align:start position:0% +and handling fee um anyway they're going +to do an experiment on that or many + + align:start position:0% +to do an experiment on that or many + + + align:start position:0% +to do an experiment on that or many +sellers have done experiments on that + + align:start position:0% +sellers have done experiments on that + + + align:start position:0% +sellers have done experiments on that +and then they also have this sort of + + align:start position:0% +and then they also have this sort of + + + align:start position:0% +and then they also have this sort of +third paper about how and why to reserve + + align:start position:0% +third paper about how and why to reserve + + + align:start position:0% +third paper about how and why to reserve +prices affect revenues I'm just going to + + align:start position:0% +prices affect revenues I'm just going to + + + align:start position:0% +prices affect revenues I'm just going to +talk about the third one because it it + + align:start position:0% +talk about the third one because it it + + + align:start position:0% +talk about the third one because it it +sort of feeds back to sort of things I + + align:start position:0% +sort of feeds back to sort of things I + + + align:start position:0% +sort of feeds back to sort of things I +talked about in the auction literature + + align:start position:0% +talked about in the auction literature + + + align:start position:0% +talked about in the auction literature +about optimal Reserve prices and + + align:start position:0% +about optimal Reserve prices and + + + align:start position:0% +about optimal Reserve prices and +auctions okay here's just their + + align:start position:0% +auctions okay here's just their + + + align:start position:0% +auctions okay here's just their +motivating figure to explain eBay + + align:start position:0% +motivating figure to explain eBay + + + align:start position:0% +motivating figure to explain eBay +experiment ments you know like so they + + align:start position:0% +experiment ments you know like so they + + + align:start position:0% +experiment ments you know like so they +did a search for um Tailor Made Driver + + align:start position:0% +did a search for um Tailor Made Driver + + + align:start position:0% +did a search for um Tailor Made Driver +tailor made is a brand of of uh you know + + align:start position:0% +tailor made is a brand of of uh you know + + + align:start position:0% +tailor made is a brand of of uh you know +golf cob manufacturer you do a search + + align:start position:0% +golf cob manufacturer you do a search + + + align:start position:0% +golf cob manufacturer you do a search +for Tailor Made Driver on eBay and you + + align:start position:0% +for Tailor Made Driver on eBay and you + + + align:start position:0% +for Tailor Made Driver on eBay and you +just see a screen like this that's just + + align:start position:0% +just see a screen like this that's just + + + align:start position:0% +just see a screen like this that's just +full of um people selling new and used + + align:start position:0% +full of um people selling new and used + + + align:start position:0% +full of um people selling new and used +um golf clubs and it looks like there's + + align:start position:0% +um golf clubs and it looks like there's + + + align:start position:0% +um golf clubs and it looks like there's +just a zillion different golf clubs out + + align:start position:0% +just a zillion different golf clubs out + + + align:start position:0% +just a zillion different golf clubs out +there on eBay but if you do a more + + align:start position:0% +there on eBay but if you do a more + + + align:start position:0% +there on eBay but if you do a more +specific search um so for this specific + + align:start position:0% +specific search um so for this specific + + + align:start position:0% +specific search um so for this specific +search they typed in tailor made burner + + align:start position:0% +search they typed in tailor made burner + + + align:start position:0% +search they typed in tailor made burner +09 driver 2009 Golf Club new quote 10 + + align:start position:0% +09 driver 2009 Golf Club new quote 10 + + + align:start position:0% +09 driver 2009 Golf Club new quote 10 +RH uh and so you do this very specific + + align:start position:0% +RH uh and so you do this very specific + + + align:start position:0% +RH uh and so you do this very specific +search and then what do you find you + + align:start position:0% +search and then what do you find you + + + align:start position:0% +search and then what do you find you +find that there is one seller who uses + + align:start position:0% +find that there is one seller who uses + + + align:start position:0% +find that there is one seller who uses +that as his title when he sells tailor + + align:start position:0% +that as his title when he sells tailor + + + align:start position:0% +that as his title when he sells tailor +made drivers online and so all the + + align:start position:0% +made drivers online and so all the + + + align:start position:0% +made drivers online and so all the +searches say tailor made burner 09 + + align:start position:0% +searches say tailor made burner 09 + + + align:start position:0% +searches say tailor made burner 09 +driver 2009 Golf Club new 10.5 degrees + + align:start position:0% +driver 2009 Golf Club new 10.5 degrees + + + align:start position:0% +driver 2009 Golf Club new 10.5 degrees +right hand okay and what you'll notice + + align:start position:0% +right hand okay and what you'll notice + + + align:start position:0% +right hand okay and what you'll notice +in this thing is that the seller has + + align:start position:0% +in this thing is that the seller has + + + align:start position:0% +in this thing is that the seller has +these many many auctions this one's + + align:start position:0% +these many many auctions this one's + + + align:start position:0% +these many many auctions this one's +closing in 3 hours and 21 minutes this + + align:start position:0% +closing in 3 hours and 21 minutes this + + + align:start position:0% +closing in 3 hours and 21 minutes this +one closes in 3 hours and 22 minutes + + align:start position:0% +one closes in 3 hours and 22 minutes + + + align:start position:0% +one closes in 3 hours and 22 minutes +this one closes in 6 hours and 9 Minutes + + align:start position:0% +this one closes in 6 hours and 9 Minutes + + + align:start position:0% +this one closes in 6 hours and 9 Minutes +6 hours and 9 Minutes 8 hours 59 + + align:start position:0% +6 hours and 9 Minutes 8 hours 59 + + + align:start position:0% +6 hours and 9 Minutes 8 hours 59 +941 you know so this seller is selling + + align:start position:0% +941 you know so this seller is selling + + + align:start position:0% +941 you know so this seller is selling +auctioning off eight of these in the + + align:start position:0% +auctioning off eight of these in the + + + align:start position:0% +auctioning off eight of these in the +next 12 hours and you can see this + + align:start position:0% +next 12 hours and you can see this + + + align:start position:0% +next 12 hours and you can see this +seller is conducting an experiment this + + align:start position:0% +seller is conducting an experiment this + + + align:start position:0% +seller is conducting an experiment this +golf club here maybe you can't see it I + + align:start position:0% +golf club here maybe you can't see it I + + + align:start position:0% +golf club here maybe you can't see it I +can uh this one has $799 shipping this + + align:start position:0% +can uh this one has $799 shipping this + + + align:start position:0% +can uh this one has $799 shipping this +one has $9.99 shipping uh this one is + + align:start position:0% +one has $9.99 shipping uh this one is + + + align:start position:0% +one has $9.99 shipping uh this one is +$9.99 shipping this one has $7.99 + + align:start position:0% +$9.99 shipping this one has $7.99 + + + align:start position:0% +$9.99 shipping this one has $7.99 +shipping so you know here it's clear + + align:start position:0% +shipping so you know here it's clear + + + align:start position:0% +shipping so you know here it's clear +these have Buy It Now prices this is + + align:start position:0% +these have Buy It Now prices this is + + + align:start position:0% +these have Buy It Now prices this is +just $125 plus $9.99 this $125 plus $799 + + align:start position:0% +just $125 plus $9.99 this $125 plus $799 + + + align:start position:0% +just $125 plus $9.99 this $125 plus $799 +if anyone saw these two listings + + align:start position:0% +if anyone saw these two listings + + + align:start position:0% +if anyone saw these two listings +obviously no one would buy this one but + + align:start position:0% +obviously no one would buy this one but + + + align:start position:0% +obviously no one would buy this one but +they're just mixed in with that big list + + align:start position:0% +they're just mixed in with that big list + + + align:start position:0% +they're just mixed in with that big list +people may only see one versus the other + + align:start position:0% +people may only see one versus the other + + + align:start position:0% +people may only see one versus the other +it's + + align:start position:0% +it's + + + align:start position:0% +it's +unclear uh what's going to happen uh + + align:start position:0% +unclear uh what's going to happen uh + + + align:start position:0% +unclear uh what's going to happen uh +anyway so this is one sell's experiment + + align:start position:0% +anyway so this is one sell's experiment + + + align:start position:0% +anyway so this is one sell's experiment +and their ideaas that there are many + + align:start position:0% +and their ideaas that there are many + + + align:start position:0% +and their ideaas that there are many +many many of these experiments out there + + align:start position:0% +many many of these experiments out there + + + align:start position:0% +many many of these experiments out there +but this is sort of one of the 244,000 + + align:start position:0% +but this is sort of one of the 244,000 + + + align:start position:0% +but this is sort of one of the 244,000 +they're analyzing + + align:start position:0% + + + + align:start position:0% + +okay what where well so you know I guess + + align:start position:0% +okay what where well so you know I guess + + + align:start position:0% +okay what where well so you know I guess +you know the seller probably doesn't + + align:start position:0% +you know the seller probably doesn't + + + align:start position:0% +you know the seller probably doesn't +know whether a $799 shipping or a $999 + + align:start position:0% +know whether a $799 shipping or a $999 + + + align:start position:0% +know whether a $799 shipping or a $999 +shipping produces better profits so + + align:start position:0% +shipping produces better profits so + + + align:start position:0% +shipping produces better profits so +they're probably just auctioning both of + + align:start position:0% +they're probably just auctioning both of + + + align:start position:0% +they're probably just auctioning both of +them off and they may have been doing + + align:start position:0% +them off and they may have been doing + + + align:start position:0% +them off and they may have been doing +this for a few weeks and then stopped + + align:start position:0% +this for a few weeks and then stopped + + + align:start position:0% +this for a few weeks and then stopped +and settled on whichever one was better + + align:start position:0% +and settled on whichever one was better + + + align:start position:0% +and settled on whichever one was better +um certainly this Buy It Now versus the + + align:start position:0% +um certainly this Buy It Now versus the + + + align:start position:0% +um certainly this Buy It Now versus the +auction there are probably some people + + align:start position:0% +auction there are probably some people + + + align:start position:0% +auction there are probably some people +who prefer one to the other and so you + + align:start position:0% +who prefer one to the other and so you + + + align:start position:0% +who prefer one to the other and so you +probably sell both ways + + align:start position:0% + + + + align:start position:0% + +um but you know you definitely you + + align:start position:0% +um but you know you definitely you + + + align:start position:0% +um but you know you definitely you +actually see you know something you see + + align:start position:0% +actually see you know something you see + + + align:start position:0% +actually see you know something you see +in their data is you see people with + + align:start position:0% +in their data is you see people with + + + align:start position:0% +in their data is you see people with +conducting auctions where the starting + + align:start position:0% +conducting auctions where the starting + + + align:start position:0% +conducting auctions where the starting +price in the auction is above the Buy It + + align:start position:0% +price in the auction is above the Buy It + + + align:start position:0% +price in the auction is above the Buy It +Now price so it does seem like there are + + align:start position:0% +Now price so it does seem like there are + + + align:start position:0% +Now price so it does seem like there are +people who just see an auction and + + align:start position:0% +people who just see an auction and + + + align:start position:0% +people who just see an auction and +decide to enter it and other people who + + align:start position:0% +decide to enter it and other people who + + + align:start position:0% +decide to enter it and other people who +just are looking for a fixed price and + + align:start position:0% +just are looking for a fixed price and + + + align:start position:0% +just are looking for a fixed price and +buy it and not really paying attention + + align:start position:0% +buy it and not really paying attention + + + align:start position:0% +buy it and not really paying attention +to the opposite + + align:start position:0% +to the opposite + + + align:start position:0% +to the opposite +ones um + + align:start position:0% + + + + align:start position:0% + +okay okay anyway so um how do we think + + align:start position:0% +okay okay anyway so um how do we think + + + align:start position:0% +okay okay anyway so um how do we think +about effects of Reserve prices in ipv + + align:start position:0% +about effects of Reserve prices in ipv + + + align:start position:0% +about effects of Reserve prices in ipv +auctions if you remember you know a + + align:start position:0% +auctions if you remember you know a + + + align:start position:0% +auctions if you remember you know a +basic theory of of uh Reserve prices in + + align:start position:0% +basic theory of of uh Reserve prices in + + + align:start position:0% +basic theory of of uh Reserve prices in +English auction is the reserve price in + + align:start position:0% +English auction is the reserve price in + + + align:start position:0% +English auction is the reserve price in +English auction is the Monopoly price to + + align:start position:0% +English auction is the Monopoly price to + + + align:start position:0% +English auction is the Monopoly price to +one bidder and the logic was just you're + + align:start position:0% +one bidder and the logic was just you're + + + align:start position:0% +one bidder and the logic was just you're +selling this good once you found out + + align:start position:0% +selling this good once you found out + + + align:start position:0% +selling this good once you found out +what the second highest value is the + + align:start position:0% +what the second highest value is the + + + align:start position:0% +what the second highest value is the +value of the the willingness to pay of + + align:start position:0% +value of the the willingness to pay of + + + align:start position:0% +value of the the willingness to pay of +the high value bidder is just the + + align:start position:0% +the high value bidder is just the + + + align:start position:0% +the high value bidder is just the +distribution truncated at the point + + align:start position:0% +distribution truncated at the point + + + align:start position:0% +distribution truncated at the point +which you know their value is at least + + align:start position:0% +which you know their value is at least + + + align:start position:0% +which you know their value is at least +that and so you're just Monopoly pricing + + align:start position:0% +that and so you're just Monopoly pricing + + + align:start position:0% +that and so you're just Monopoly pricing +on the single bidder + + align:start position:0% +on the single bidder + + + align:start position:0% +on the single bidder +distribution uh and so it's just the + + align:start position:0% +distribution uh and so it's just the + + + align:start position:0% +distribution uh and so it's just the +optimal reserve price is the Monopoly + + align:start position:0% +optimal reserve price is the Monopoly + + + align:start position:0% +optimal reserve price is the Monopoly +price right you had + + align:start position:0% +price right you had + + + align:start position:0% +price right you had +this distribution of of values once + + align:start position:0% +this distribution of of values once + + + align:start position:0% +this distribution of of values once +everyone else has dropped out here all + + align:start position:0% +everyone else has dropped out here all + + + align:start position:0% +everyone else has dropped out here all +you know is that you're facing you're + + align:start position:0% +you know is that you're facing you're + + + align:start position:0% +you know is that you're facing you're +selling to someone whose draw is from + + align:start position:0% +selling to someone whose draw is from + + + align:start position:0% +selling to someone whose draw is from +you know this is + + align:start position:0% +you know this is + + + align:start position:0% +you know this is +the this is the second highest bid + + align:start position:0% + + + + align:start position:0% + +nope um okay anyway so you have this + + align:start position:0% +nope um okay anyway so you have this + + + align:start position:0% +nope um okay anyway so you have this +distribution of the second highest bid + + align:start position:0% +distribution of the second highest bid + + + align:start position:0% +distribution of the second highest bid +you're pricing to that you set the + + align:start position:0% +you're pricing to that you set the + + + align:start position:0% +you're pricing to that you set the +Monopoly price on that demand + + align:start position:0% +Monopoly price on that demand + + + align:start position:0% +Monopoly price on that demand +curve they also note that if we want to + + align:start position:0% +curve they also note that if we want to + + + align:start position:0% +curve they also note that if we want to +sort of think about this empirically how + + align:start position:0% +sort of think about this empirically how + + + align:start position:0% +sort of think about this empirically how +does a reserve price effect um what's + + align:start position:0% +does a reserve price effect um what's + + + align:start position:0% +does a reserve price effect um what's +the optimal reserve price here's another + + align:start position:0% +the optimal reserve price here's another + + + align:start position:0% +the optimal reserve price here's another +good way to think about so this is + + align:start position:0% +good way to think about so this is + + + align:start position:0% +good way to think about so this is +density F of if you want to think about + + align:start position:0% +density F of if you want to think about + + + align:start position:0% +density F of if you want to think about +how does a reserve price affect things + + align:start position:0% +how does a reserve price affect things + + + align:start position:0% +how does a reserve price affect things +what I can do is just imagine an + + align:start position:0% +what I can do is just imagine an + + + align:start position:0% +what I can do is just imagine an +experiment where the seller has used + + align:start position:0% +experiment where the seller has used + + + align:start position:0% +experiment where the seller has used +many many different Reserve prices like + + align:start position:0% +many many different Reserve prices like + + + align:start position:0% +many many different Reserve prices like +they've used Reserve they've started the + + align:start position:0% +they've used Reserve they've started the + + + align:start position:0% +they've used Reserve they've started the +bidding at $1 $5 $10 20 30 40 50 for + + align:start position:0% +bidding at $1 $5 $10 20 30 40 50 for + + + align:start position:0% +bidding at $1 $5 $10 20 30 40 50 for +every reserve price you can just draw a + + align:start position:0% +every reserve price you can just draw a + + + align:start position:0% +every reserve price you can just draw a +graph which is if I res use a reserve + + align:start position:0% +graph which is if I res use a reserve + + + align:start position:0% +graph which is if I res use a reserve +price of you know 5% of the expected + + align:start position:0% +price of you know 5% of the expected + + + align:start position:0% +price of you know 5% of the expected +sale + + align:start position:0% +sale + + + align:start position:0% +sale +price what's the eventual um price at + + align:start position:0% +price what's the eventual um price at + + + align:start position:0% +price what's the eventual um price at +which I sell the + + align:start position:0% +which I sell the + + + align:start position:0% +which I sell the +good and what's the + + align:start position:0% +good and what's the + + + align:start position:0% +good and what's the +um if I if I use a very low reserve + + align:start position:0% +um if I if I use a very low reserve + + + align:start position:0% +um if I if I use a very low reserve +price I sell the good with probability + + align:start position:0% +price I sell the good with probability + + + align:start position:0% +price I sell the good with probability +0.9 or 0.95 but I get a fairly low + + align:start position:0% +0.9 or 0.95 but I get a fairly low + + + align:start position:0% +0.9 or 0.95 but I get a fairly low +average price and then if I sell it with + + align:start position:0% +average price and then if I sell it with + + + align:start position:0% +average price and then if I sell it with +a $20 Reserve maybe I sell the good with + + align:start position:0% +a $20 Reserve maybe I sell the good with + + + align:start position:0% +a $20 Reserve maybe I sell the good with +probability 08 and I get a higher + + align:start position:0% +probability 08 and I get a higher + + + align:start position:0% +probability 08 and I get a higher +average price and if I sell it with a + + align:start position:0% +average price and if I sell it with a + + + align:start position:0% +average price and if I sell it with a +reserve that's 120% of the average price + + align:start position:0% +reserve that's 120% of the average price + + + align:start position:0% +reserve that's 120% of the average price +for the good maybe I sell it with just + + align:start position:0% +for the good maybe I sell it with just + + + align:start position:0% +for the good maybe I sell it with just +some very small probability but I do get + + align:start position:0% +some very small probability but I do get + + + align:start position:0% +some very small probability but I do get +a very high price of selling so what you + + align:start position:0% +a very high price of selling so what you + + + align:start position:0% +a very high price of selling so what you +can basically do is just look at every + + align:start position:0% +can basically do is just look at every + + + align:start position:0% +can basically do is just look at every +reserve price the data and figure out + + align:start position:0% +reserve price the data and figure out + + + align:start position:0% +reserve price the data and figure out +what's the probability that the good + + align:start position:0% +what's the probability that the good + + + align:start position:0% +what's the probability that the good +sells and what's the expected price + + align:start position:0% +sells and what's the expected price + + + align:start position:0% +sells and what's the expected price +conditional on its selling and that's + + align:start position:0% +conditional on its selling and that's + + + align:start position:0% +conditional on its selling and that's +basically just your demand curve you can + + align:start position:0% +basically just your demand curve you can + + + align:start position:0% +basically just your demand curve you can +sort of view that as demand curve and + + align:start position:0% +sort of view that as demand curve and + + + align:start position:0% +sort of view that as demand curve and +you're just trying to Monopoly price on + + align:start position:0% +you're just trying to Monopoly price on + + + align:start position:0% +you're just trying to Monopoly price on +that curve so that's a second way to + + align:start position:0% +that curve so that's a second way to + + + align:start position:0% +that curve so that's a second way to +think about optimal pricing Reserve + + align:start position:0% +think about optimal pricing Reserve + + + align:start position:0% +think about optimal pricing Reserve +pricing is just draw this demand curve + + align:start position:0% +pricing is just draw this demand curve + + + align:start position:0% +pricing is just draw this demand curve +like object and think about what would + + align:start position:0% +like object and think about what would + + + align:start position:0% +like object and think about what would +be the Monopoly price on that and that + + align:start position:0% +be the Monopoly price on that and that + + + align:start position:0% +be the Monopoly price on that and that +would be the way to figure out what the + + align:start position:0% +would be the way to figure out what the + + + align:start position:0% +would be the way to figure out what the +optimal reserve price is so that would + + align:start position:0% +optimal reserve price is so that would + + + align:start position:0% +optimal reserve price is so that would +be an experimental way to figure out my + + align:start position:0% +be an experimental way to figure out my + + + align:start position:0% +be an experimental way to figure out my +op reserve price without you know + + align:start position:0% +op reserve price without you know + + + align:start position:0% +op reserve price without you know +theoretically you want to say what's the + + align:start position:0% +theoretically you want to say what's the + + + align:start position:0% +theoretically you want to say what's the +distribution from which the values are + + align:start position:0% +distribution from which the values are + + + align:start position:0% +distribution from which the values are +being drawn but without think about what + + align:start position:0% +being drawn but without think about what + + + align:start position:0% +being drawn but without think about what +the distribution from which values are + + align:start position:0% +the distribution from which values are + + + align:start position:0% +the distribution from which values are +being drawn you could just make this + + align:start position:0% +being drawn you could just make this + + + align:start position:0% +being drawn you could just make this +curve Monopoly price relative to + + align:start position:0% +curve Monopoly price relative to + + + align:start position:0% +curve Monopoly price relative to +it okay um you know there several + + align:start position:0% +it okay um you know there several + + + align:start position:0% +it okay um you know there several +reasons why this Simple Theory may not + + align:start position:0% +reasons why this Simple Theory may not + + + align:start position:0% +reasons why this Simple Theory may not +work in practice um one is entry costs + + align:start position:0% +work in practice um one is entry costs + + + align:start position:0% +work in practice um one is entry costs +if you imagine there's some cost to a + + align:start position:0% +if you imagine there's some cost to a + + + align:start position:0% +if you imagine there's some cost to a +bidder of starting to bid in an auction + + align:start position:0% +bidder of starting to bid in an auction + + + align:start position:0% +bidder of starting to bid in an auction +and look examining the good in detail + + align:start position:0% +and look examining the good in detail + + + align:start position:0% +and look examining the good in detail +if there's a low price they may be + + align:start position:0% +if there's a low price they may be + + + align:start position:0% +if there's a low price they may be +willing to pay the entry cost if they + + align:start position:0% +willing to pay the entry cost if they + + + align:start position:0% +willing to pay the entry cost if they +see that the reserve price is $110 they + + align:start position:0% +see that the reserve price is $110 they + + + align:start position:0% +see that the reserve price is $110 they +may not bother to read all the fine + + align:start position:0% +may not bother to read all the fine + + + align:start position:0% +may not bother to read all the fine +print and enter that auction um you know + + align:start position:0% +print and enter that auction um you know + + + align:start position:0% +print and enter that auction um you know +there could be some kind of common value + + align:start position:0% +there could be some kind of common value + + + align:start position:0% +there could be some kind of common value +component this theory was uh once I know + + align:start position:0% +component this theory was uh once I know + + + align:start position:0% +component this theory was uh once I know +everybody else's bid my bid is unchanged + + align:start position:0% +everybody else's bid my bid is unchanged + + + align:start position:0% +everybody else's bid my bid is unchanged +there common values the theory changes + + align:start position:0% +there common values the theory changes + + + align:start position:0% +there common values the theory changes +and then they also note that there could + + align:start position:0% +and then they also note that there could + + + align:start position:0% +and then they also note that there could +be you know speaking of this Theory and + + align:start position:0% +be you know speaking of this Theory and + + + align:start position:0% +be you know speaking of this Theory and +why this Theory may not work um you + + align:start position:0% +why this Theory may not work um you + + + align:start position:0% +why this Theory may not work um you +could also have sort of Behavioral + + align:start position:0% +could also have sort of Behavioral + + + align:start position:0% +could also have sort of Behavioral +preferences like loss Avers if you + + align:start position:0% +preferences like loss Avers if you + + + align:start position:0% +preferences like loss Avers if you +imagine you know the loss version is + + align:start position:0% +imagine you know the loss version is + + + align:start position:0% +imagine you know the loss version is +always like I feel bad losing something + + align:start position:0% +always like I feel bad losing something + + + align:start position:0% +always like I feel bad losing something +that I have if you sort of start the + + align:start position:0% +that I have if you sort of start the + + + align:start position:0% +that I have if you sort of start the +bidding at a very low price and people + + align:start position:0% +bidding at a very low price and people + + + align:start position:0% +bidding at a very low price and people +get used to the idea of owning this + + align:start position:0% +get used to the idea of owning this + + + align:start position:0% +get used to the idea of owning this +fancy golf club because they see it + + align:start position:0% +fancy golf club because they see it + + + align:start position:0% +fancy golf club because they see it +being bid for $20 once they've got used + + align:start position:0% +being bid for $20 once they've got used + + + align:start position:0% +being bid for $20 once they've got used +to the fact that they have this this + + align:start position:0% +to the fact that they have this this + + + align:start position:0% +to the fact that they have this this +fancy Golf Club then they may feel loss + + align:start position:0% +fancy Golf Club then they may feel loss + + + align:start position:0% +fancy Golf Club then they may feel loss +aversion if they don't win the golf club + + align:start position:0% +aversion if they don't win the golf club + + + align:start position:0% +aversion if they don't win the golf club +You by by getting people sort of tied up + + align:start position:0% +You by by getting people sort of tied up + + + align:start position:0% +You by by getting people sort of tied up +in the bidding they may get used to the + + align:start position:0% +in the bidding they may get used to the + + + align:start position:0% +in the bidding they may get used to the +thought of winning and then they may did + + align:start position:0% +thought of winning and then they may did + + + align:start position:0% +thought of winning and then they may did +more in the end um anyway to sort of to + + align:start position:0% +more in the end um anyway to sort of to + + + align:start position:0% +more in the end um anyway to sort of to +examine this uh what they do is uh they + + align:start position:0% +examine this uh what they do is uh they + + + align:start position:0% +examine this uh what they do is uh they +find a data set where they found 19,000 + + align:start position:0% +find a data set where they found 19,000 + + + align:start position:0% +find a data set where they found 19,000 +experiments where there's several + + align:start position:0% +experiments where there's several + + + align:start position:0% +experiments where there's several +features uh one is there's variation in + + align:start position:0% +features uh one is there's variation in + + + align:start position:0% +features uh one is there's variation in +the start price uh there's free shipping + + align:start position:0% +the start price uh there's free shipping + + + align:start position:0% +the start price uh there's free shipping +which just simplifies things there's no + + align:start position:0% +which just simplifies things there's no + + + align:start position:0% +which just simplifies things there's no +secret reserve price no Buy It Now + + align:start position:0% +secret reserve price no Buy It Now + + + align:start position:0% +secret reserve price no Buy It Now +auction so these are just straight plain + + align:start position:0% +auction so these are just straight plain + + + align:start position:0% +auction so these are just straight plain +vanilla auctions of a good many + + align:start position:0% +vanilla auctions of a good many + + + align:start position:0% +vanilla auctions of a good many +different times okay uh and so these + + align:start position:0% +different times okay uh and so these + + + align:start position:0% +different times okay uh and so these +about 25 uh listings uh per experiment + + align:start position:0% +about 25 uh listings uh per experiment + + + align:start position:0% +about 25 uh listings uh per experiment +so again these are just sellers + + align:start position:0% +so again these are just sellers + + + align:start position:0% +so again these are just sellers +experimenting with you know sellers + + align:start position:0% +experimenting with you know sellers + + + align:start position:0% +experimenting with you know sellers +experimenting with what's what if I'm + + align:start position:0% +experimenting with what's what if I'm + + + align:start position:0% +experimenting with what's what if I'm +selling $125 Golf Club should I start + + align:start position:0% +selling $125 Golf Club should I start + + + align:start position:0% +selling $125 Golf Club should I start +the bidding at $5 or $100 or 50 or + + align:start position:0% +the bidding at $5 or $100 or 50 or + + + align:start position:0% +the bidding at $5 or $100 or 50 or +something in + + align:start position:0% +something in + + + align:start position:0% +something in +between uh figure five in the paper + + align:start position:0% +between uh figure five in the paper + + + align:start position:0% +between uh figure five in the paper +shows that yes sellers are doing this a + + align:start position:0% +shows that yes sellers are doing this a + + + align:start position:0% +shows that yes sellers are doing this a +lot so let's look at a typical category + + align:start position:0% +lot so let's look at a typical category + + + align:start position:0% +lot so let's look at a typical category +like Goods that cost between $30 and + + align:start position:0% +like Goods that cost between $30 and + + + align:start position:0% +like Goods that cost between $30 and +$100 and you can see Goods where the you + + align:start position:0% +$100 and you can see Goods where the you + + + align:start position:0% +$100 and you can see Goods where the you +know that cost between this is like the + + align:start position:0% +know that cost between this is like the + + + align:start position:0% +know that cost between this is like the +average price at which they're sold when + + align:start position:0% +average price at which they're sold when + + + align:start position:0% +average price at which they're sold when +they sell them through the through just + + align:start position:0% +they sell them through the through just + + + align:start position:0% +they sell them through the through just +a fixed price sale and you can see Goods + + align:start position:0% +a fixed price sale and you can see Goods + + + align:start position:0% +a fixed price sale and you can see Goods +that sell for $30 to $100 20% of the + + align:start position:0% +that sell for $30 to $100 20% of the + + + align:start position:0% +that sell for $30 to $100 20% of the +sellers start them out at zero in these + + align:start position:0% +sellers start them out at zero in these + + + align:start position:0% +sellers start them out at zero in these +experiments uh and then uh 37% start + + align:start position:0% +experiments uh and then uh 37% start + + + align:start position:0% +experiments uh and then uh 37% start +them out between 85 to 100% of the sort + + align:start position:0% +them out between 85 to 100% of the sort + + + align:start position:0% +them out between 85 to 100% of the sort +of average fixed price sale 17% choose + + align:start position:0% +of average fixed price sale 17% choose + + + align:start position:0% +of average fixed price sale 17% choose +60 to 80 133% are actually starting them + + align:start position:0% +60 to 80 133% are actually starting them + + + align:start position:0% +60 to 80 133% are actually starting them +off above the sort of average Buy It Now + + align:start position:0% +off above the sort of average Buy It Now + + + align:start position:0% +off above the sort of average Buy It Now +average fixed price sales um but we get + + align:start position:0% +average fixed price sales um but we get + + + align:start position:0% +average fixed price sales um but we get +the sort of Buy modal distribution + + align:start position:0% +the sort of Buy modal distribution + + + align:start position:0% +the sort of Buy modal distribution +notably there are very few sellers + + align:start position:0% +notably there are very few sellers + + + align:start position:0% +notably there are very few sellers +starting out in here it seems like if + + align:start position:0% +starting out in here it seems like if + + + align:start position:0% +starting out in here it seems like if +you're going to go low you just go all + + align:start position:0% +you're going to go low you just go all + + + align:start position:0% +you're going to go low you just go all +the way down to the bottom and start at + + align:start position:0% +the way down to the bottom and start at + + + align:start position:0% +the way down to the bottom and start at +almost + + align:start position:0% +almost + + + align:start position:0% +almost +zero okay and then the sort of this with + + align:start position:0% +zero okay and then the sort of this with + + + align:start position:0% +zero okay and then the sort of this with +a lot of within experiment variation so + + align:start position:0% +a lot of within experiment variation so + + + align:start position:0% +a lot of within experiment variation so +if you look at auctions in which there + + align:start position:0% +if you look at auctions in which there + + + align:start position:0% +if you look at auctions in which there +some sellers are sometimes selling it at + + align:start position:0% +some sellers are sometimes selling it at + + + align:start position:0% +some sellers are sometimes selling it at +less than 5% those same sellers were + + align:start position:0% +less than 5% those same sellers were + + + align:start position:0% +less than 5% those same sellers were +sometimes selling it at less than 5% are + + align:start position:0% +sometimes selling it at less than 5% are + + + align:start position:0% +sometimes selling it at less than 5% are +also sometimes selling 5 to 45 45 to 85 + + align:start position:0% +also sometimes selling 5 to 45 45 to 85 + + + align:start position:0% +also sometimes selling 5 to 45 45 to 85 +85 to 100 100 to 120 greater than 120 so + + align:start position:0% +85 to 100 100 to 120 greater than 120 so + + + align:start position:0% +85 to 100 100 to 120 greater than 120 so +there just many experiments where + + align:start position:0% +there just many experiments where + + + align:start position:0% +there just many experiments where +sellers are trying out the whole range + + align:start position:0% +sellers are trying out the whole range + + + align:start position:0% +sellers are trying out the whole range +themselves this is sort of our + + align:start position:0% +themselves this is sort of our + + + align:start position:0% +themselves this is sort of our +experimental paper that we get to run + + align:start position:0% +experimental paper that we get to run + + + align:start position:0% +experimental paper that we get to run +without having to actually pay for the + + align:start position:0% + + + + align:start position:0% + +experiments um okay so does the sort of + + align:start position:0% +experiments um okay so does the sort of + + + align:start position:0% +experiments um okay so does the sort of +standard uh auction demand Theory work + + align:start position:0% +standard uh auction demand Theory work + + + align:start position:0% +standard uh auction demand Theory work +uh and the answer is no um there's one + + align:start position:0% +uh and the answer is no um there's one + + + align:start position:0% +uh and the answer is no um there's one +interesting feature which is the demand + + align:start position:0% +interesting feature which is the demand + + + align:start position:0% +interesting feature which is the demand +curve turns up at very low prices so you + + align:start position:0% +curve turns up at very low prices so you + + + align:start position:0% +curve turns up at very low prices so you +know remember I I drew this curve for + + align:start position:0% +know remember I I drew this curve for + + + align:start position:0% +know remember I I drew this curve for +you saying if I start the good at only + + align:start position:0% +you saying if I start the good at only + + + align:start position:0% +you saying if I start the good at only +$5 if I start the good at + + align:start position:0% +$5 if I start the good at + + + align:start position:0% +$5 if I start the good at +$1 um you if I start the good at $1 I + + align:start position:0% +$1 um you if I start the good at $1 I + + + align:start position:0% +$1 um you if I start the good at $1 I +sell it almost entirely for sure but I'm + + align:start position:0% +sell it almost entirely for sure but I'm + + + align:start position:0% +sell it almost entirely for sure but I'm +going to have a lower average price than + + align:start position:0% +going to have a lower average price than + + + align:start position:0% +going to have a lower average price than +if I start the good at a higher price uh + + align:start position:0% +if I start the good at a higher price uh + + + align:start position:0% +if I start the good at a higher price uh +what they find is that the curve doesn't + + align:start position:0% +what they find is that the curve doesn't + + + align:start position:0% +what they find is that the curve doesn't +look like this um the curve looks like + + align:start position:0% +look like this um the curve looks like + + + align:start position:0% +look like this um the curve looks like +this um + + align:start position:0% + + + + align:start position:0% + +so as I start at a lower and lower price + + align:start position:0% +so as I start at a lower and lower price + + + align:start position:0% +so as I start at a lower and lower price +not only do I sell for a higher with a + + align:start position:0% +not only do I sell for a higher with a + + + align:start position:0% +not only do I sell for a higher with a +higher probability I sell at a higher + + align:start position:0% +higher probability I sell at a higher + + + align:start position:0% +higher probability I sell at a higher +price conditional on selling so I'm up + + align:start position:0% +price conditional on selling so I'm up + + + align:start position:0% +price conditional on selling so I'm up +here I'm selling at 90% probability and + + align:start position:0% +here I'm selling at 90% probability and + + + align:start position:0% +here I'm selling at 90% probability and +I'm getting a higher price than I would + + align:start position:0% +I'm getting a higher price than I would + + + align:start position:0% +I'm getting a higher price than I would +get if I chose reserve price that only + + align:start position:0% +get if I chose reserve price that only + + + align:start position:0% +get if I chose reserve price that only +sold with 70% + + align:start position:0% +sold with 70% + + + align:start position:0% +sold with 70% +probability so the demand curve turns up + + align:start position:0% +probability so the demand curve turns up + + + align:start position:0% +probability so the demand curve turns up +you know it's suggesting that I put the + + align:start position:0% +you know it's suggesting that I put the + + + align:start position:0% +you know it's suggesting that I put the +$100 item out there started bidding at + + align:start position:0% +$100 item out there started bidding at + + + align:start position:0% +$100 item out there started bidding at +$1 lots of people see it at a dollar 10 + + align:start position:0% +$1 lots of people see it at a dollar 10 + + + align:start position:0% +$1 lots of people see it at a dollar 10 +hours before the auction is over they + + align:start position:0% +hours before the auction is over they + + + align:start position:0% +hours before the auction is over they +all start following the auction they all + + align:start position:0% +all start following the auction they all + + + align:start position:0% +all start following the auction they all +start bidding I get more probably I get + + align:start position:0% +start bidding I get more probably I get + + + align:start position:0% +start bidding I get more probably I get +more entry than I would if I started it + + align:start position:0% +more entry than I would if I started it + + + align:start position:0% +more entry than I would if I started it +at uh $20 instead so the curve instead + + align:start position:0% +at uh $20 instead so the curve instead + + + align:start position:0% +at uh $20 instead so the curve instead +of looking like this you know looks like + + align:start position:0% +of looking like this you know looks like + + + align:start position:0% +of looking like this you know looks like +this + + align:start position:0% + + + + align:start position:0% + +instead and if you you know you + + align:start position:0% +instead and if you you know you + + + align:start position:0% +instead and if you you know you +obviously how do we do Monopoly pricing + + align:start position:0% +obviously how do we do Monopoly pricing + + + align:start position:0% +obviously how do we do Monopoly pricing +you know like the way to think about + + align:start position:0% +you know like the way to think about + + + align:start position:0% +you know like the way to think about +Monopoly pricing is you do marginal + + align:start position:0% +Monopoly pricing is you do marginal + + + align:start position:0% +Monopoly pricing is you do marginal +revenue equals marginal cost so they + + align:start position:0% +revenue equals marginal cost so they + + + align:start position:0% +revenue equals marginal cost so they +take this demand curve they construct + + align:start position:0% +take this demand curve they construct + + + align:start position:0% +take this demand curve they construct +the marginal revenue curve and the + + align:start position:0% +the marginal revenue curve and the + + + align:start position:0% +the marginal revenue curve and the +marginal revenue curve also turns + + align:start position:0% +marginal revenue curve also turns + + + align:start position:0% +marginal revenue curve also turns +up so if you have a marginal you know + + align:start position:0% +up so if you have a marginal you know + + + align:start position:0% +up so if you have a marginal you know +like we're used to sort of marginal + + align:start position:0% +like we're used to sort of marginal + + + align:start position:0% +like we're used to sort of marginal +revenue is downward sloping you draw + + align:start position:0% +revenue is downward sloping you draw + + + align:start position:0% +revenue is downward sloping you draw +marginal cost across where marginal + + align:start position:0% +marginal cost across where marginal + + + align:start position:0% +marginal cost across where marginal +revenue hits marginal cost that's the + + align:start position:0% +revenue hits marginal cost that's the + + + align:start position:0% +revenue hits marginal cost that's the +that's the Monopoly price what do you do + + align:start position:0% +that's the Monopoly price what do you do + + + align:start position:0% +that's the Monopoly price what do you do +when marginal revenue turns up you know + + align:start position:0% +when marginal revenue turns up you know + + + align:start position:0% +when marginal revenue turns up you know +so if if + + align:start position:0% +so if if + + + align:start position:0% +so if if +um if this is my marginal revenue curve + + align:start position:0% +um if this is my marginal revenue curve + + + align:start position:0% +um if this is my marginal revenue curve +my marginal cost is flat that's my + + align:start position:0% +my marginal cost is flat that's my + + + align:start position:0% +my marginal cost is flat that's my +normal Monopoly pricing uh what do I do + + align:start position:0% +normal Monopoly pricing uh what do I do + + + align:start position:0% +normal Monopoly pricing uh what do I do +if marginal revenue turns + + align:start position:0% +if marginal revenue turns + + + align:start position:0% +if marginal revenue turns +up + + align:start position:0% +up + + + align:start position:0% +up +then I can draw the line across where + + align:start position:0% +then I can draw the line across where + + + align:start position:0% +then I can draw the line across where +marginal revenue equals marginal cost + + align:start position:0% +marginal revenue equals marginal cost + + + align:start position:0% +marginal revenue equals marginal cost +this is a local opt locally optimal + + align:start position:0% +this is a local opt locally optimal + + + align:start position:0% +this is a local opt locally optimal +Monopoly price but the solution is + + align:start position:0% +Monopoly price but the solution is + + + align:start position:0% +Monopoly price but the solution is +either going to be this point or this + + align:start position:0% +either going to be this point or this + + + align:start position:0% +either going to be this point or this +point right you know it doesn't have to + + align:start position:0% +point right you know it doesn't have to + + + align:start position:0% +point right you know it doesn't have to +intersect again it could be that you get + + align:start position:0% +intersect again it could be that you get + + + align:start position:0% +intersect again it could be that you get +a you know here your revenue is + + align:start position:0% +a you know here your revenue is + + + align:start position:0% +a you know here your revenue is +increasing so it may be that you want to + + align:start position:0% +increasing so it may be that you want to + + + align:start position:0% +increasing so it may be that you want to +sort of price there you know you may + + align:start position:0% +sort of price there you know you may + + + align:start position:0% +sort of price there you know you may +want a price here that may be the global + + align:start position:0% +want a price here that may be the global + + + align:start position:0% +want a price here that may be the global +Optimum or this could be the global + + align:start position:0% +Optimum or this could be the global + + + align:start position:0% +Optimum or this could be the global +Optimum but you're going to do one or + + align:start position:0% +Optimum but you're going to do one or + + + align:start position:0% +Optimum but you're going to do one or +the + + align:start position:0% +the + + + align:start position:0% +the +other uh anyway and so that's I guess in + + align:start position:0% +other uh anyway and so that's I guess in + + + align:start position:0% +other uh anyway and so that's I guess in +some sense the um you + + align:start position:0% +some sense the um you + + + align:start position:0% +some sense the um you +know this is sort of how they explain + + align:start position:0% +know this is sort of how they explain + + + align:start position:0% +know this is sort of how they explain +what's going on in the data if you + + align:start position:0% +what's going on in the data if you + + + align:start position:0% +what's going on in the data if you +remember in the data there was a lot of + + align:start position:0% +remember in the data there was a lot of + + + align:start position:0% +remember in the data there was a lot of +firms figure five you know like there + + align:start position:0% +firms figure five you know like there + + + align:start position:0% +firms figure five you know like there +were a lot of firms charging fairly High + + align:start position:0% +were a lot of firms charging fairly High + + + align:start position:0% +were a lot of firms charging fairly High +uh Reserve prices and then some firms + + align:start position:0% +uh Reserve prices and then some firms + + + align:start position:0% +uh Reserve prices and then some firms +charging very low Reserve prices and so + + align:start position:0% +charging very low Reserve prices and so + + + align:start position:0% +charging very low Reserve prices and so +you know their thought is that what's + + align:start position:0% +you know their thought is that what's + + + align:start position:0% +you know their thought is that what's +going on in the data is probably + + align:start position:0% +going on in the data is probably + + + align:start position:0% +going on in the data is probably +something like this where the marginal + + align:start position:0% +something like this where the marginal + + + align:start position:0% +something like this where the marginal +cost is pretty high so you + + align:start position:0% +cost is pretty high so you + + + align:start position:0% +cost is pretty high so you +either set a quite High reserve price + + align:start position:0% +either set a quite High reserve price + + + align:start position:0% +either set a quite High reserve price +and this is the optimum or you set this + + align:start position:0% +and this is the optimum or you set this + + + align:start position:0% +and this is the optimum or you set this +right end point and for different + + align:start position:0% +right end point and for different + + + align:start position:0% +right end point and for different +sellers different ones are + + align:start position:0% + + + + align:start position:0% + +optimal and you know in general if your + + align:start position:0% +optimal and you know in general if your + + + align:start position:0% +optimal and you know in general if your +marginal cost is high you're going to + + align:start position:0% +marginal cost is high you're going to + + + align:start position:0% +marginal cost is high you're going to +just set the high reserve price your + + align:start position:0% +just set the high reserve price your + + + align:start position:0% +just set the high reserve price your +marginal cost is low you're going to be + + align:start position:0% +marginal cost is low you're going to be + + + align:start position:0% +marginal cost is low you're going to be +setting the right end point + + align:start position:0% +setting the right end point + + + align:start position:0% +setting the right end point +you know and then the paper tries to do + + align:start position:0% +you know and then the paper tries to do + + + align:start position:0% +you know and then the paper tries to do +other predictions it tries to have a + + align:start position:0% +other predictions it tries to have a + + + align:start position:0% +other predictions it tries to have a +test of this sort of upper tail + + align:start position:0% +test of this sort of upper tail + + + align:start position:0% +test of this sort of upper tail +hypothesis of is the sort of does the + + align:start position:0% +hypothesis of is the sort of does the + + + align:start position:0% +hypothesis of is the sort of does the +upper tail of the price distribution + + align:start position:0% +upper tail of the price distribution + + + align:start position:0% +upper tail of the price distribution +look the same regardless of of what + + align:start position:0% +look the same regardless of of what + + + align:start position:0% +look the same regardless of of what +reserve price you use and that test only + + align:start position:0% +reserve price you use and that test only + + + align:start position:0% +reserve price you use and that test only +works so well so it it does seem like + + align:start position:0% +works so well so it it does seem like + + + align:start position:0% +works so well so it it does seem like +the sort of classic Theory this sort of + + align:start position:0% +the sort of classic Theory this sort of + + + align:start position:0% +the sort of classic Theory this sort of +upper tail distribution is is just what + + align:start position:0% +upper tail distribution is is just what + + + align:start position:0% +upper tail distribution is is just what +you get by truncating isn't quite right + + align:start position:0% +you get by truncating isn't quite right + + + align:start position:0% +you get by truncating isn't quite right +here um and it does seem to Ender this + + align:start position:0% +here um and it does seem to Ender this + + + align:start position:0% +here um and it does seem to Ender this +sort of it's entry costs are important + + align:start position:0% +sort of it's entry costs are important + + + align:start position:0% +sort of it's entry costs are important +for online auctions is the I think the + + align:start position:0% +for online auctions is the I think the + + + align:start position:0% +for online auctions is the I think the +main message + + align:start position:0% +main message + + + align:start position:0% +main message +there okay + + align:start position:0% + + + + align:start position:0% + +questions yeah you know obviously I I + + align:start position:0% +questions yeah you know obviously I I + + + align:start position:0% +questions yeah you know obviously I I +think that's something you + + align:start position:0% +think that's something you + + + align:start position:0% +think that's something you +know uh uh that work was done inside + + align:start position:0% +know uh uh that work was done inside + + + align:start position:0% +know uh uh that work was done inside +eBay you know for a long time eBay + + align:start position:0% +eBay you know for a long time eBay + + + align:start position:0% +eBay you know for a long time eBay +actually had this sort of very very uh + + align:start position:0% +actually had this sort of very very uh + + + align:start position:0% +actually had this sort of very very uh +open policy to academics and we actually + + align:start position:0% +open policy to academics and we actually + + + align:start position:0% +open policy to academics and we actually +had several students like after they + + align:start position:0% +had several students like after they + + + align:start position:0% +had several students like after they +finish their phds here go to a postc for + + align:start position:0% +finish their phds here go to a postc for + + + align:start position:0% +finish their phds here go to a postc for +a year and sit at eBay because eBay + + align:start position:0% +a year and sit at eBay because eBay + + + align:start position:0% +a year and sit at eBay because eBay +would let you sit there and operate in + + align:start position:0% +would let you sit there and operate in + + + align:start position:0% +would let you sit there and operate in +inside the company and do all kinds of + + align:start position:0% +inside the company and do all kinds of + + + align:start position:0% +inside the company and do all kinds of +stuff with their full data set uh that + + align:start position:0% +stuff with their full data set uh that + + + align:start position:0% +stuff with their full data set uh that +seems to have faded away in you know + + align:start position:0% +seems to have faded away in you know + + + align:start position:0% +seems to have faded away in you know +three or four years ago um but obviously + + align:start position:0% +three or four years ago um but obviously + + + align:start position:0% +three or four years ago um but obviously +one could still scrape eBay and do the + + align:start position:0% +one could still scrape eBay and do the + + + align:start position:0% +one could still scrape eBay and do the +same kinds of + + align:start position:0% +same kinds of + + + align:start position:0% +same kinds of +things okay so then the + + align:start position:0% +things okay so then the + + + align:start position:0% +things okay so then the +um second topic that I guess is common + + align:start position:0% +um second topic that I guess is common + + + align:start position:0% +um second topic that I guess is common +to the rest of the papers I'm going to + + align:start position:0% +to the rest of the papers I'm going to + + + align:start position:0% +to the rest of the papers I'm going to +talk about is just + + align:start position:0% +talk about is just + + + align:start position:0% +talk about is just +understanding uh how online retail works + + align:start position:0% +understanding uh how online retail works + + + align:start position:0% +understanding uh how online retail works +and why why it's + + align:start position:0% +and why why it's + + + align:start position:0% +and why why it's +successful you know if you read people + + align:start position:0% +successful you know if you read people + + + align:start position:0% +successful you know if you read people +writing about uh e-commerce in the early + + align:start position:0% +writing about uh e-commerce in the early + + + align:start position:0% +writing about uh e-commerce in the early +in the internet era there's this + + align:start position:0% +in the internet era there's this + + + align:start position:0% +in the internet era there's this +question of is online retail ever going + + align:start position:0% +question of is online retail ever going + + + align:start position:0% +question of is online retail ever going +to really take off and displace + + align:start position:0% +to really take off and displace + + + align:start position:0% +to really take off and displace +traditional retail and the biggest + + align:start position:0% +traditional retail and the biggest + + + align:start position:0% +traditional retail and the biggest +argument against online retail taking + + align:start position:0% +argument against online retail taking + + + align:start position:0% +argument against online retail taking +off was that it's just much more + + align:start position:0% +off was that it's just much more + + + align:start position:0% +off was that it's just much more +expensive um you know like in if you + + align:start position:0% +expensive um you know like in if you + + + align:start position:0% +expensive um you know like in if you +look at the long history of retail in + + align:start position:0% +look at the long history of retail in + + + align:start position:0% +look at the long history of retail in +America you know in the8 1800s people + + align:start position:0% +America you know in the8 1800s people + + + align:start position:0% +America you know in the8 1800s people +shopped in department stores uh and then + + align:start position:0% +shopped in department stores uh and then + + + align:start position:0% +shopped in department stores uh and then +there was this Golden Era of catalog + + align:start position:0% +there was this Golden Era of catalog + + + align:start position:0% +there was this Golden Era of catalog +retail where like the Sears + + align:start position:0% +retail where like the Sears + + + align:start position:0% +retail where like the Sears +catalog you know in some sense brought + + align:start position:0% +catalog you know in some sense brought + + + align:start position:0% +catalog you know in some sense brought +products to the you know that were only + + align:start position:0% +products to the you know that were only + + + align:start position:0% +products to the you know that were only +formally available in cities to all of + + align:start position:0% +formally available in cities to all of + + + align:start position:0% +formally available in cities to all of +America and they had like this phone + + align:start position:0% +America and they had like this phone + + + align:start position:0% +America and they had like this phone +book well you know thousand page thick + + align:start position:0% +book well you know thousand page thick + + + align:start position:0% +book well you know thousand page thick +catalog that they would mail you you + + align:start position:0% +catalog that they would mail you you + + + align:start position:0% +catalog that they would mail you you +could buy anything from the Sears + + align:start position:0% +could buy anything from the Sears + + + align:start position:0% +could buy anything from the Sears +catalog you know Sears catalog just took + + align:start position:0% +catalog you know Sears catalog just took + + + align:start position:0% +catalog you know Sears catalog just took +off in the I think it's I guess it's + + align:start position:0% +off in the I think it's I guess it's + + + align:start position:0% +off in the I think it's I guess it's +late 1800s after there were sort of + + align:start position:0% +late 1800s after there were sort of + + + align:start position:0% +late 1800s after there were sort of +train or whatever they would bring + + align:start position:0% +train or whatever they would bring + + + align:start position:0% +train or whatever they would bring +packages to people uh when the car was + + align:start position:0% +packages to people uh when the car was + + + align:start position:0% +packages to people uh when the car was +invented the Sears catalog just went + + align:start position:0% +invented the Sears catalog just went + + + align:start position:0% +invented the Sears catalog just went +into a prolonged Decline and Sears + + align:start position:0% +into a prolonged Decline and Sears + + + align:start position:0% +into a prolonged Decline and Sears +opened you know massive you know not the + + align:start position:0% +opened you know massive you know not the + + + align:start position:0% +opened you know massive you know not the +size of a Walmart but you know massive + + align:start position:0% +size of a Walmart but you know massive + + + align:start position:0% +size of a Walmart but you know massive +department stores in many US cities and + + align:start position:0% +department stores in many US cities and + + + align:start position:0% +department stores in many US cities and +then again the catalog business declined + + align:start position:0% +then again the catalog business declined + + + align:start position:0% +then again the catalog business declined +the physical retail business took off + + align:start position:0% +the physical retail business took off + + + align:start position:0% +the physical retail business took off +you know thoughts on why that was + + align:start position:0% +you know thoughts on why that was + + + align:start position:0% +you know thoughts on why that was +catalog retail was just always much more + + align:start position:0% +catalog retail was just always much more + + + align:start position:0% +catalog retail was just always much more +expensive than traditional retail like + + align:start position:0% +expensive than traditional retail like + + + align:start position:0% +expensive than traditional retail like +if you look at + + align:start position:0% +if you look at + + + align:start position:0% +if you look at +Walmart uh Walmart's cost of selling + + align:start position:0% +Walmart uh Walmart's cost of selling + + + align:start position:0% +Walmart uh Walmart's cost of selling +Goods is + + align:start position:0% +Goods is + + + align:start position:0% +Goods is +roughly uh 20% of the merchandise that + + align:start position:0% +roughly uh 20% of the merchandise that + + + align:start position:0% +roughly uh 20% of the merchandise that +they sell um catalog retail had cost + + align:start position:0% +they sell um catalog retail had cost + + + align:start position:0% +they sell um catalog retail had cost +more like 40 or + + align:start position:0% +more like 40 or + + + align:start position:0% +more like 40 or +50% uh and why is it cost Walmart only + + align:start position:0% +50% uh and why is it cost Walmart only + + + align:start position:0% +50% uh and why is it cost Walmart only +20% when it cost catalog retail + + align:start position:0% +20% when it cost catalog retail + + + align:start position:0% +20% when it cost catalog retail +50% you know it's it's + + align:start position:0% +50% you know it's it's + + + align:start position:0% +50% you know it's it's +because catalog retail you know you need + + align:start position:0% +because catalog retail you know you need + + + align:start position:0% +because catalog retail you know you need +to have stuff in a warehouse every + + align:start position:0% +to have stuff in a warehouse every + + + align:start position:0% +to have stuff in a warehouse every +single item that gets sold someone needs + + align:start position:0% +single item that gets sold someone needs + + + align:start position:0% +single item that gets sold someone needs +to put it in a box put the box in the + + align:start position:0% +to put it in a box put the box in the + + + align:start position:0% +to put it in a box put the box in the +mail pay for the mail whereas you know + + align:start position:0% +mail pay for the mail whereas you know + + + align:start position:0% +mail pay for the mail whereas you know +Walmart's cost of putting you know like + + align:start position:0% +Walmart's cost of putting you know like + + + align:start position:0% +Walmart's cost of putting you know like +simplest example of like things never + + align:start position:0% +simplest example of like things never + + + align:start position:0% +simplest example of like things never +online like you know like a kitty + + align:start position:0% +online like you know like a kitty + + + align:start position:0% +online like you know like a kitty +swimming pool one of those plastic 4ot + + align:start position:0% +swimming pool one of those plastic 4ot + + + align:start position:0% +swimming pool one of those plastic 4ot +diameter swimming pools you can put a + + align:start position:0% +diameter swimming pools you can put a + + + align:start position:0% +diameter swimming pools you can put a +whole bunch of 4ot diameter plastic + + align:start position:0% +whole bunch of 4ot diameter plastic + + + align:start position:0% +whole bunch of 4ot diameter plastic +swimming pools stack them together put + + align:start position:0% +swimming pools stack them together put + + + align:start position:0% +swimming pools stack them together put +them in a truck take them to the Walmart + + align:start position:0% +them in a truck take them to the Walmart + + + align:start position:0% +them in a truck take them to the Walmart +and the cost of getting them there is is + + align:start position:0% +and the cost of getting them there is is + + + align:start position:0% +and the cost of getting them there is is +you know 50 cents or something like that + + align:start position:0% +you know 50 cents or something like that + + + align:start position:0% +you know 50 cents or something like that +you try to put a kitty swimming pool in + + align:start position:0% +you try to put a kitty swimming pool in + + + align:start position:0% +you try to put a kitty swimming pool in +the mail and send it to somebody you + + align:start position:0% +the mail and send it to somebody you + + + align:start position:0% +the mail and send it to somebody you +spent you know $30 mailing something + + align:start position:0% +spent you know $30 mailing something + + + align:start position:0% +spent you know $30 mailing something +that's only worth five or something and + + align:start position:0% +that's only worth five or something and + + + align:start position:0% +that's only worth five or something and +you know the putting things in a truck + + align:start position:0% +you know the putting things in a truck + + + align:start position:0% +you know the putting things in a truck +is just much much cheaper than packaging + + align:start position:0% +is just much much cheaper than packaging + + + align:start position:0% +is just much much cheaper than packaging +handling every package individually and + + align:start position:0% +handling every package individually and + + + align:start position:0% +handling every package individually and +you're getting some sense the Free Labor + + align:start position:0% +you're getting some sense the Free Labor + + + align:start position:0% +you're getting some sense the Free Labor +of people to just walk through the store + + align:start position:0% +of people to just walk through the store + + + align:start position:0% +of people to just walk through the store +and take it off the shelf and carry it + + align:start position:0% +and take it off the shelf and carry it + + + align:start position:0% +and take it off the shelf and carry it +home + + align:start position:0% +home + + + align:start position:0% +home +um anyway you know early on a Amazon was + + align:start position:0% +um anyway you know early on a Amazon was + + + align:start position:0% +um anyway you know early on a Amazon was +undercutting phys Barnes & Noble and + + align:start position:0% +undercutting phys Barnes & Noble and + + + align:start position:0% +undercutting phys Barnes & Noble and +selling books for lower than you would + + align:start position:0% +selling books for lower than you would + + + align:start position:0% +selling books for lower than you would +buy the books in a physical bookstore + + align:start position:0% +buy the books in a physical bookstore + + + align:start position:0% +buy the books in a physical bookstore +and there's a question of could could + + align:start position:0% +and there's a question of could could + + + align:start position:0% +and there's a question of could could +Amazon ever actually make a profit + + align:start position:0% +Amazon ever actually make a profit + + + align:start position:0% +Amazon ever actually make a profit +selling things not at a loss and sell if + + align:start position:0% +selling things not at a loss and sell if + + + align:start position:0% +selling things not at a loss and sell if +Amazon were pricing things at cost or + + align:start position:0% +Amazon were pricing things at cost or + + + align:start position:0% +Amazon were pricing things at cost or +above cost could it be competitive with + + align:start position:0% +above cost could it be competitive with + + + align:start position:0% +above cost could it be competitive with +traditional retail um one of the big + + align:start position:0% +traditional retail um one of the big + + + align:start position:0% +traditional retail um one of the big +arguments that was made early on was + + align:start position:0% +arguments that was made early on was + + + align:start position:0% +arguments that was made early on was +that yes Amazon doesn't need to have a + + align:start position:0% +that yes Amazon doesn't need to have a + + + align:start position:0% +that yes Amazon doesn't need to have a +cost advantage to sell things online it + + align:start position:0% +cost advantage to sell things online it + + + align:start position:0% +cost advantage to sell things online it +could be that you have a cost + + align:start position:0% +could be that you have a cost + + + align:start position:0% +could be that you have a cost +disadvantage but people buy online + + align:start position:0% +disadvantage but people buy online + + + align:start position:0% +disadvantage but people buy online +because of the product variety they + + align:start position:0% +because of the product variety they + + + align:start position:0% +because of the product variety they +product variety advantages are much + + align:start position:0% +product variety advantages are much + + + align:start position:0% +product variety advantages are much +bigger than the cost disad Vantage so + + align:start position:0% +bigger than the cost disad Vantage so + + + align:start position:0% +bigger than the cost disad Vantage so +therefore people buy online to get the + + align:start position:0% +therefore people buy online to get the + + + align:start position:0% +therefore people buy online to get the +book they want or whatever product they + + align:start position:0% +book they want or whatever product they + + + align:start position:0% +book they want or whatever product they +want that have a much bigger selection + + align:start position:0% +want that have a much bigger selection + + + align:start position:0% +want that have a much bigger selection +um and you know they note that when + + align:start position:0% +um and you know they note that when + + + align:start position:0% +um and you know they note that when +Amazon launched Amazon had 1 million + + align:start position:0% +Amazon launched Amazon had 1 million + + + align:start position:0% +Amazon launched Amazon had 1 million +titles obviously it later expanded to + + align:start position:0% +titles obviously it later expanded to + + + align:start position:0% +titles obviously it later expanded to +several million titles and a lot a very + + align:start position:0% +several million titles and a lot a very + + + align:start position:0% +several million titles and a lot a very +large physical bookstore at the time + + align:start position:0% +large physical bookstore at the time + + + align:start position:0% +large physical bookstore at the time +would have 100,000 titles your sort of + + align:start position:0% +would have 100,000 titles your sort of + + + align:start position:0% +would have 100,000 titles your sort of +typical bookstore might have 50,000 + + align:start position:0% +typical bookstore might have 50,000 + + + align:start position:0% +typical bookstore might have 50,000 +titles in it uh you know perhaps there's + + align:start position:0% +titles in it uh you know perhaps there's + + + align:start position:0% +titles in it uh you know perhaps there's +some supert some super stores that would + + align:start position:0% +some supert some super stores that would + + + align:start position:0% +some supert some super stores that would +have 200,000 but Amazon had many many + + align:start position:0% +have 200,000 but Amazon had many many + + + align:start position:0% +have 200,000 but Amazon had many many +more books than uh even from the very + + align:start position:0% +more books than uh even from the very + + + align:start position:0% +more books than uh even from the very +beginning Than Physical bookstores did + + align:start position:0% +beginning Than Physical bookstores did + + + align:start position:0% +beginning Than Physical bookstores did +um and so what Bolson who and Smith try + + align:start position:0% +um and so what Bolson who and Smith try + + + align:start position:0% +um and so what Bolson who and Smith try +to do is just sort of say could we + + align:start position:0% +to do is just sort of say could we + + + align:start position:0% +to do is just sort of say could we +estimate how big the product variety + + align:start position:0% +estimate how big the product variety + + + align:start position:0% +estimate how big the product variety +benefit is by just in some sense looking + + align:start position:0% +benefit is by just in some sense looking + + + align:start position:0% +benefit is by just in some sense looking +at this demand curve like finding out um + + align:start position:0% +at this demand curve like finding out um + + + align:start position:0% +at this demand curve like finding out um +what fraction of the sales of Amazon are + + align:start position:0% +what fraction of the sales of Amazon are + + + align:start position:0% +what fraction of the sales of Amazon are +um to books that are beyond the 100 + + align:start position:0% +um to books that are beyond the 100 + + + align:start position:0% +um to books that are beyond the 100 +100,000th book so so say there 100,000 + + align:start position:0% +100,000th book so so say there 100,000 + + + align:start position:0% +100,000th book so so say there 100,000 +books that are available in your + + align:start position:0% +books that are available in your + + + align:start position:0% +books that are available in your +physical bookstore there are millions of + + align:start position:0% +physical bookstore there are millions of + + + align:start position:0% +physical bookstore there are millions of +other books that are not available in a + + align:start position:0% +other books that are not available in a + + + align:start position:0% +other books that are not available in a +physical bookstore how much utility to + + align:start position:0% +physical bookstore how much utility to + + + align:start position:0% +physical bookstore how much utility to +people get from buying all those books + + align:start position:0% +people get from buying all those books + + + align:start position:0% +people get from buying all those books +from 100,000 out to 2 million uh and the + + align:start position:0% +from 100,000 out to 2 million uh and the + + + align:start position:0% +from 100,000 out to 2 million uh and the +way they do that is to just + + align:start position:0% +way they do that is to just + + + align:start position:0% +way they do that is to just +basically you know convert Amazon sales + + align:start position:0% +basically you know convert Amazon sales + + + align:start position:0% +basically you know convert Amazon sales +ranks to quantities figure out how many + + align:start position:0% +ranks to quantities figure out how many + + + align:start position:0% +ranks to quantities figure out how many +copies of every book are being sold and + + align:start position:0% +copies of every book are being sold and + + + align:start position:0% +copies of every book are being sold and +then just count up how many book what + + align:start position:0% +then just count up how many book what + + + align:start position:0% +then just count up how many book what +fraction of Amazon sales or books + + align:start position:0% +fraction of Amazon sales or books + + + align:start position:0% +fraction of Amazon sales or books +outside the top 100 ,000 and then + + align:start position:0% +outside the top 100 ,000 and then + + + align:start position:0% +outside the top 100 ,000 and then +multiply them by just a consumer surplus + + align:start position:0% +multiply them by just a consumer surplus + + + align:start position:0% +multiply them by just a consumer surplus +estimate per title if you know if you + + align:start position:0% +estimate per title if you know if you + + + align:start position:0% +estimate per title if you know if you +have a general sense of the demand + + align:start position:0% +have a general sense of the demand + + + align:start position:0% +have a general sense of the demand +elasticity you know the average price + + align:start position:0% +elasticity you know the average price + + + align:start position:0% +elasticity you know the average price +you know the consumer you can just sort + + align:start position:0% +you know the consumer you can just sort + + + align:start position:0% +you know the consumer you can just sort +of guess what the consumer surplus is uh + + align:start position:0% +of guess what the consumer surplus is uh + + + align:start position:0% +of guess what the consumer surplus is uh +and estimate + + align:start position:0% +and estimate + + + align:start position:0% +and estimate +that and what they show in this figure + + align:start position:0% +that and what they show in this figure + + + align:start position:0% +that and what they show in this figure +is that uh if you look at books that are + + align:start position:0% +is that uh if you look at books that are + + + align:start position:0% +is that uh if you look at books that are +sort of outside the top 100,000 there + + align:start position:0% +sort of outside the top 100,000 there + + + align:start position:0% +sort of outside the top 100,000 there +seems to be this very very thick or very + + align:start position:0% +seems to be this very very thick or very + + + align:start position:0% +seems to be this very very thick or very +very slow decline in sales so you know + + align:start position:0% +very slow decline in sales so you know + + + align:start position:0% +very slow decline in sales so you know +book number 100,000 is selling one and a + + align:start position:0% +book number 100,000 is selling one and a + + + align:start position:0% +book number 100,000 is selling one and a +half cop a week uh book number 200,000 + + align:start position:0% +half cop a week uh book number 200,000 + + + align:start position:0% +half cop a week uh book number 200,000 +is selling 8 book number 400 is selling + + align:start position:0% +is selling 8 book number 400 is selling + + + align:start position:0% +is selling 8 book number 400 is selling +6 copies a week book number six is spell + + align:start position:0% +6 copies a week book number six is spell + + + align:start position:0% +6 copies a week book number six is spell +selling like 04 but then when you get to + + align:start position:0% +selling like 04 but then when you get to + + + align:start position:0% +selling like 04 but then when you get to +book 2.2 million book 2.2 million is not + + align:start position:0% +book 2.2 million book 2.2 million is not + + + align:start position:0% +book 2.2 million book 2.2 million is not +selling that many fewer copies than book + + align:start position:0% +selling that many fewer copies than book + + + align:start position:0% +selling that many fewer copies than book +600,000 and so because this tale doesn't + + align:start position:0% +600,000 and so because this tale doesn't + + + align:start position:0% +600,000 and so because this tale doesn't +just sort of go to zero very quickly + + align:start position:0% +just sort of go to zero very quickly + + + align:start position:0% +just sort of go to zero very quickly +there are lots of sales on Amazon that + + align:start position:0% +there are lots of sales on Amazon that + + + align:start position:0% +there are lots of sales on Amazon that +are these extra books uh and the thought + + align:start position:0% +are these extra books uh and the thought + + + align:start position:0% +are these extra books uh and the thought +is that all these extra books are you + + align:start position:0% +is that all these extra books are you + + + align:start position:0% +is that all these extra books are you +know you know contributing a lot to + + align:start position:0% +know you know contributing a lot to + + + align:start position:0% +know you know contributing a lot to +consumer + + align:start position:0% +consumer + + + align:start position:0% +consumer +surplus what they estimate in their + + align:start position:0% +surplus what they estimate in their + + + align:start position:0% +surplus what they estimate in their +paper is that the sort of product + + align:start position:0% +paper is that the sort of product + + + align:start position:0% +paper is that the sort of product +variety back in 2000 when Amazon was + + align:start position:0% +variety back in 2000 when Amazon was + + + align:start position:0% +variety back in 2000 when Amazon was +still young was adding 700 million to a + + align:start position:0% +still young was adding 700 million to a + + + align:start position:0% +still young was adding 700 million to a +billion uh to consumer surplus and that + + align:start position:0% +billion uh to consumer surplus and that + + + align:start position:0% +billion uh to consumer surplus and that +was about you know Amazon was lowering + + align:start position:0% +was about you know Amazon was lowering + + + align:start position:0% +was about you know Amazon was lowering +prices I think it was by Amazon was 5 to + + align:start position:0% +prices I think it was by Amazon was 5 to + + + align:start position:0% +prices I think it was by Amazon was 5 to +10% cheaper than than physical + + align:start position:0% +10% cheaper than than physical + + + align:start position:0% +10% cheaper than than physical +bookstores at the time and what I find + + align:start position:0% +bookstores at the time and what I find + + + align:start position:0% +bookstores at the time and what I find +is that look at the gain from the lower + + align:start position:0% +is that look at the gain from the lower + + + align:start position:0% +is that look at the gain from the lower +prices the 5 to 10% lower prices look at + + align:start position:0% +prices the 5 to 10% lower prices look at + + + align:start position:0% +prices the 5 to 10% lower prices look at +the gains from the uh consumer surplus + + align:start position:0% +the gains from the uh consumer surplus + + + align:start position:0% +the gains from the uh consumer surplus +and the gains from the lower prices were + + align:start position:0% +and the gains from the lower prices were + + + align:start position:0% +and the gains from the lower prices were +only about 100 million a year the gains + + align:start position:0% +only about 100 million a year the gains + + + align:start position:0% +only about 100 million a year the gains +from the consumer surplus is like a + + align:start position:0% +from the consumer surplus is like a + + + align:start position:0% +from the consumer surplus is like a +billion dollars a year so consumer + + align:start position:0% +billion dollars a year so consumer + + + align:start position:0% +billion dollars a year so consumer +surplus is 10 times as important as the + + align:start position:0% +surplus is 10 times as important as the + + + align:start position:0% +surplus is 10 times as important as the +price cut and so if if you believe that + + align:start position:0% +price cut and so if if you believe that + + + align:start position:0% +price cut and so if if you believe that +if consumer surplus is 10 times as + + align:start position:0% +if consumer surplus is 10 times as + + + align:start position:0% +if consumer surplus is 10 times as +important there's a price cut you know + + align:start position:0% +important there's a price cut you know + + + align:start position:0% +important there's a price cut you know +you could take away the 100 million or + + align:start position:0% +you could take away the 100 million or + + + align:start position:0% +you could take away the 100 million or +even take have a negative 100 million or + + align:start position:0% +even take have a negative 100 million or + + + align:start position:0% +even take have a negative 100 million or +negative 200 million and they say that + + align:start position:0% +negative 200 million and they say that + + + align:start position:0% +negative 200 million and they say that +Amazon really could raise prices and + + align:start position:0% +Amazon really could raise prices and + + + align:start position:0% +Amazon really could raise prices and +still be a positive value for consumers + + align:start position:0% +still be a positive value for consumers + + + align:start position:0% +still be a positive value for consumers +because the product variety effect + + align:start position:0% + + + + align:start position:0% + +say it is a you know I mean it's a very + + align:start position:0% +say it is a you know I mean it's a very + + + align:start position:0% +say it is a you know I mean it's a very +nice paper it's a fairly the calculation + + align:start position:0% +nice paper it's a fairly the calculation + + + align:start position:0% +nice paper it's a fairly the calculation +itself is a little speculative in that + + align:start position:0% +itself is a little speculative in that + + + align:start position:0% +itself is a little speculative in that +you know it is uh you know we don't have + + align:start position:0% +you know it is uh you know we don't have + + + align:start position:0% +you know it is uh you know we don't have +a lot of EV you know like if you think + + align:start position:0% +a lot of EV you know like if you think + + + align:start position:0% +a lot of EV you know like if you think +about like you know any of these books + + align:start position:0% +about like you know any of these books + + + align:start position:0% +about like you know any of these books +that are sold very rarely it's very hard + + align:start position:0% +that are sold very rarely it's very hard + + + align:start position:0% +that are sold very rarely it's very hard +to get much evidence of what the demand + + align:start position:0% +to get much evidence of what the demand + + + align:start position:0% +to get much evidence of what the demand +curves look like for them because + + align:start position:0% +curves look like for them because + + + align:start position:0% +curves look like for them because +they're hardly selling any copies you + + align:start position:0% +they're hardly selling any copies you + + + align:start position:0% +they're hardly selling any copies you +are sort of extrapolating on some things + + align:start position:0% +are sort of extrapolating on some things + + + align:start position:0% +are sort of extrapolating on some things +there um okay so then the paper I want + + align:start position:0% +there um okay so then the paper I want + + + align:start position:0% +there um okay so then the paper I want +to talk about more is um uh Quan and + + align:start position:0% +to talk about more is um uh Quan and + + + align:start position:0% +to talk about more is um uh Quan and +Williams uh product iy market + + align:start position:0% +Williams uh product iy market + + + align:start position:0% +Williams uh product iy market +heterogenity and this is an argument + + align:start position:0% +heterogenity and this is an argument + + + align:start position:0% +heterogenity and this is an argument +that The bolon Who and Smith paper May + + align:start position:0% +that The bolon Who and Smith paper May + + + align:start position:0% +that The bolon Who and Smith paper May +really be + + align:start position:0% +really be + + + align:start position:0% +really be +overestimating uh product variety + + align:start position:0% +overestimating uh product variety + + + align:start position:0% +overestimating uh product variety +advantages and the reason they would + + align:start position:0% +advantages and the reason they would + + + align:start position:0% +advantages and the reason they would +argue this could be really overestimate + + align:start position:0% +argue this could be really overestimate + + + align:start position:0% +argue this could be really overestimate +profit variety advantages is because + + align:start position:0% +profit variety advantages is because + + + align:start position:0% +profit variety advantages is because +different physical bookstores carry + + align:start position:0% +different physical bookstores carry + + + align:start position:0% +different physical bookstores carry +different books so for instance you know + + align:start position:0% +different books so for instance you know + + + align:start position:0% +different books so for instance you know +people at the time needed to get + + align:start position:0% +people at the time needed to get + + + align:start position:0% +people at the time needed to get +textbooks for all of their graduate + + align:start position:0% +textbooks for all of their graduate + + + align:start position:0% +textbooks for all of their graduate +economics classes where would you get + + align:start position:0% +economics classes where would you get + + + align:start position:0% +economics classes where would you get +textbooks for graduate economics classes + + align:start position:0% +textbooks for graduate economics classes + + + align:start position:0% +textbooks for graduate economics classes +none of them are in the top 100,000 most + + align:start position:0% +none of them are in the top 100,000 most + + + align:start position:0% +none of them are in the top 100,000 most +popular books in the United States + + align:start position:0% +popular books in the United States + + + align:start position:0% +popular books in the United States +however you go to the MIT Coupe in the + + align:start position:0% +however you go to the MIT Coupe in the + + + align:start position:0% +however you go to the MIT Coupe in the +week before classes start and they would + + align:start position:0% +week before classes start and they would + + + align:start position:0% +week before classes start and they would +have all of The Graduate economics + + align:start position:0% +have all of The Graduate economics + + + align:start position:0% +have all of The Graduate economics +textbooks and all the other textbooks + + align:start position:0% +textbooks and all the other textbooks + + + align:start position:0% +textbooks and all the other textbooks +for all of your other classes would be + + align:start position:0% +for all of your other classes would be + + + align:start position:0% +for all of your other classes would be +in the MIT Coupe and you know not just + + align:start position:0% +in the MIT Coupe and you know not just + + + align:start position:0% +in the MIT Coupe and you know not just +the graduate economics textbooks to MIT + + align:start position:0% +the graduate economics textbooks to MIT + + + align:start position:0% +the graduate economics textbooks to MIT +Coupe but like the MIT Coupe also has a + + align:start position:0% +Coupe but like the MIT Coupe also has a + + + align:start position:0% +Coupe but like the MIT Coupe also has a +big selection of you know technical + + align:start position:0% +big selection of you know technical + + + align:start position:0% +big selection of you know technical +books and if you just want books about + + align:start position:0% +books and if you just want books about + + + align:start position:0% +books and if you just want books about +computer programming or whatever not for + + align:start position:0% +computer programming or whatever not for + + + align:start position:0% +computer programming or whatever not for +your classes they have lots of those + + align:start position:0% +your classes they have lots of those + + + align:start position:0% +your classes they have lots of those +books in that bookstores and then you + + align:start position:0% +books in that bookstores and then you + + + align:start position:0% +books in that bookstores and then you +know there are other bookstores in + + align:start position:0% +know there are other bookstores in + + + align:start position:0% +know there are other bookstores in +Boston where if you're interested in art + + align:start position:0% +Boston where if you're interested in art + + + align:start position:0% +Boston where if you're interested in art +that have lots of books about art and + + align:start position:0% +that have lots of books about art and + + + align:start position:0% +that have lots of books about art and +lots of big coffee table books or + + align:start position:0% +lots of big coffee table books or + + + align:start position:0% +lots of big coffee table books or +whatever and so their thought was that + + align:start position:0% +whatever and so their thought was that + + + align:start position:0% +whatever and so their thought was that +you know the qu Williams argument is + + align:start position:0% +you know the qu Williams argument is + + + align:start position:0% +you know the qu Williams argument is +that you really could be overestimating + + align:start position:0% +that you really could be overestimating + + + align:start position:0% +that you really could be overestimating +what Amazon is doing because there are + + align:start position:0% +what Amazon is doing because there are + + + align:start position:0% +what Amazon is doing because there are +many different bookstores the many + + align:start position:0% +many different bookstores the many + + + align:start position:0% +many different bookstores the many +different bookstores have many different + + align:start position:0% +different bookstores have many different + + + align:start position:0% +different bookstores have many different +books so the gain from + + align:start position:0% +books so the gain from + + + align:start position:0% +books so the gain from +the online over going to the bookstore + + align:start position:0% +the online over going to the bookstore + + + align:start position:0% +the online over going to the bookstore +that you know what have the books you + + align:start position:0% +that you know what have the books you + + + align:start position:0% +that you know what have the books you +want could be much smaller um they study + + align:start position:0% +want could be much smaller um they study + + + align:start position:0% +want could be much smaller um they study +this not in the case of books they they + + align:start position:0% +this not in the case of books they they + + + align:start position:0% +this not in the case of books they they +pick a different industry their industry + + align:start position:0% +pick a different industry their industry + + + align:start position:0% +pick a different industry their industry +is shoes um they don't say it one + + align:start position:0% +is shoes um they don't say it one + + + align:start position:0% +is shoes um they don't say it one +suspects that they have they had a + + align:start position:0% +suspects that they have they had a + + + align:start position:0% +suspects that they have they had a +friend who worked at zapo because they + + align:start position:0% +friend who worked at zapo because they + + + align:start position:0% +friend who worked at zapo because they +sort of are working with a uh very very + + align:start position:0% +sort of are working with a uh very very + + + align:start position:0% +sort of are working with a uh very very +what they describe as a very large + + align:start position:0% +what they describe as a very large + + + align:start position:0% +what they describe as a very large +online um shoe store in the year 2012 + + align:start position:0% +online um shoe store in the year 2012 + + + align:start position:0% +online um shoe store in the year 2012 +2013 um and just here's one example of + + align:start position:0% +2013 um and just here's one example of + + + align:start position:0% +2013 um and just here's one example of +why we would think that physical shoe + + align:start position:0% +why we would think that physical shoe + + + align:start position:0% +why we would think that physical shoe +stores uh would carry different things + + align:start position:0% +stores uh would carry different things + + + align:start position:0% +stores uh would carry different things +this graph is this is entirely done with + + align:start position:0% +this graph is this is entirely done with + + + align:start position:0% +this graph is this is entirely done with +um sales on the on the uh online site + + align:start position:0% +um sales on the on the uh online site + + + align:start position:0% +um sales on the on the uh online site +what they graph is so this is a state + + align:start position:0% +what they graph is so this is a state + + + align:start position:0% +what they graph is so this is a state +level analysis for I think 49 states uh + + align:start position:0% +level analysis for I think 49 states uh + + + align:start position:0% +level analysis for I think 49 states uh +and what they put on this is just a DOT + + align:start position:0% +and what they put on this is just a DOT + + + align:start position:0% +and what they put on this is just a DOT +for every state of what fraction of the + + align:start position:0% +for every state of what fraction of the + + + align:start position:0% +for every state of what fraction of the +shoes that are sold to that state are + + align:start position:0% +shoes that are sold to that state are + + + align:start position:0% +shoes that are sold to that state are +boots and what fraction are + + align:start position:0% +boots and what fraction are + + + align:start position:0% +boots and what fraction are +sandals and you know what do you notice + + align:start position:0% +sandals and you know what do you notice + + + align:start position:0% +sandals and you know what do you notice +on the right side of this graph uh we + + align:start position:0% +on the right side of this graph uh we + + + align:start position:0% +on the right side of this graph uh we +take the two warmest US states which + + align:start position:0% +take the two warmest US states which + + + align:start position:0% +take the two warmest US states which +would be Hawaii and Florida and in + + align:start position:0% +would be Hawaii and Florida and in + + + align:start position:0% +would be Hawaii and Florida and in +Hawaii and Florida people don't buy a + + align:start position:0% +Hawaii and Florida people don't buy a + + + align:start position:0% +Hawaii and Florida people don't buy a +whole lot of boots uh and they buy a lot + + align:start position:0% +whole lot of boots uh and they buy a lot + + + align:start position:0% +whole lot of boots uh and they buy a lot +of sandals I guess especially in Florida + + align:start position:0% +of sandals I guess especially in Florida + + + align:start position:0% +of sandals I guess especially in Florida +people buy a lot of sandals uh and then + + align:start position:0% +people buy a lot of sandals uh and then + + + align:start position:0% +people buy a lot of sandals uh and then +you go down here and you look at what + + align:start position:0% +you go down here and you look at what + + + align:start position:0% +you go down here and you look at what +people are buying in you know the + + align:start position:0% +people are buying in you know the + + + align:start position:0% +people are buying in you know the +coldest States it's I don't know if + + align:start position:0% +coldest States it's I don't know if + + + align:start position:0% +coldest States it's I don't know if +that's North Dakota Wyoming Minnesota + + align:start position:0% +that's North Dakota Wyoming Minnesota + + + align:start position:0% +that's North Dakota Wyoming Minnesota +places like that people buy a lot of + + align:start position:0% +places like that people buy a lot of + + + align:start position:0% +places like that people buy a lot of +boots in North Dakota people buy fewer + + align:start position:0% +boots in North Dakota people buy fewer + + + align:start position:0% +boots in North Dakota people buy fewer +sandals in North + + align:start position:0% +sandals in North + + + align:start position:0% +sandals in North +Dakota um although I guess you know sort + + align:start position:0% +Dakota um although I guess you know sort + + + align:start position:0% +Dakota um although I guess you know sort +of surprising things you learn from this + + align:start position:0% +of surprising things you learn from this + + + align:start position:0% +of surprising things you learn from this +turns out people in North Dakota and + + align:start position:0% +turns out people in North Dakota and + + + align:start position:0% +turns out people in North Dakota and +Wyoming actually buy more sandals than + + align:start position:0% +Wyoming actually buy more sandals than + + + align:start position:0% +Wyoming actually buy more sandals than +people in Middle temperature States I + + align:start position:0% +people in Middle temperature States I + + + align:start position:0% +people in Middle temperature States I +guess it may be you know I don't know + + align:start position:0% +guess it may be you know I don't know + + + align:start position:0% +guess it may be you know I don't know +maybe if you live in a cold place you + + align:start position:0% +maybe if you live in a cold place you + + + align:start position:0% +maybe if you live in a cold place you +sort of go on vacation to Florida and + + align:start position:0% +sort of go on vacation to Florida and + + + align:start position:0% +sort of go on vacation to Florida and +you need to buy sandals or if you live + + align:start position:0% +you need to buy sandals or if you live + + + align:start position:0% +you need to buy sandals or if you live +in a medium temperature State you just + + align:start position:0% +in a medium temperature State you just + + + align:start position:0% +in a medium temperature State you just +you don't go on as many vacations to + + align:start position:0% +you don't go on as many vacations to + + + align:start position:0% +you don't go on as many vacations to +warm weather States I don't know but + + align:start position:0% +warm weather States I don't know but + + + align:start position:0% +warm weather States I don't know but +anyway you know but but you know their + + align:start position:0% +anyway you know but but you know their + + + align:start position:0% +anyway you know but but you know their +thought from this graph is if you look + + align:start position:0% +thought from this graph is if you look + + + align:start position:0% +thought from this graph is if you look +at if this is what happens for online + + align:start position:0% +at if this is what happens for online + + + align:start position:0% +at if this is what happens for online +retailers you imagine that you walk into + + align:start position:0% +retailers you imagine that you walk into + + + align:start position:0% +retailers you imagine that you walk into +you know even take a national chain + + align:start position:0% +you know even take a national chain + + + align:start position:0% +you know even take a national chain +store you imagine that the national + + align:start position:0% +store you imagine that the national + + + align:start position:0% +store you imagine that the national +chains in their North Dakota stores they + + align:start position:0% +chains in their North Dakota stores they + + + align:start position:0% +chains in their North Dakota stores they +have lots of boots on the on the shelves + + align:start position:0% +have lots of boots on the on the shelves + + + align:start position:0% +have lots of boots on the on the shelves +and in their Florida stores they have + + align:start position:0% +and in their Florida stores they have + + + align:start position:0% +and in their Florida stores they have +very few winter boots on the shelves uh + + align:start position:0% +very few winter boots on the shelves uh + + + align:start position:0% +very few winter boots on the shelves uh +and so this would just be an example + + align:start position:0% +and so this would just be an example + + + align:start position:0% +and so this would just be an example +that you know this doesn't this doesn't + + align:start position:0% +that you know this doesn't this doesn't + + + align:start position:0% +that you know this doesn't this doesn't +prove that local stores tailor + + align:start position:0% +prove that local stores tailor + + + align:start position:0% +prove that local stores tailor +their selections to what customers want + + align:start position:0% +their selections to what customers want + + + align:start position:0% +their selections to what customers want +but this at least suggests that local + + align:start position:0% +but this at least suggests that local + + + align:start position:0% +but this at least suggests that local +stores ought to tailor their selections + + align:start position:0% +stores ought to tailor their selections + + + align:start position:0% +stores ought to tailor their selections +to their customers and that ought to + + align:start position:0% +to their customers and that ought to + + + align:start position:0% +to their customers and that ought to +give you back some of the gains that we + + align:start position:0% +give you back some of the gains that we + + + align:start position:0% +give you back some of the gains that we +think is Amazon's gains from product + + align:start position:0% +think is Amazon's gains from product + + + align:start position:0% +think is Amazon's gains from product +variety should be gains from product + + align:start position:0% +variety should be gains from product + + + align:start position:0% +variety should be gains from product +variety at these + + align:start position:0% + + + + align:start position:0% + +stores you know the paper actually has + + align:start position:0% +stores you know the paper actually has + + + align:start position:0% +stores you know the paper actually has +um it has a second data set where they + + align:start position:0% +um it has a second data set where they + + + align:start position:0% +um it has a second data set where they +they also got access to the + + align:start position:0% +they also got access to the + + + align:start position:0% +they also got access to the +inventories uh of local stores at Macy's + + align:start position:0% +inventories uh of local stores at Macy's + + + align:start position:0% +inventories uh of local stores at Macy's +and Payless shoe Payless Shoes which are + + align:start position:0% +and Payless shoe Payless Shoes which are + + + align:start position:0% +and Payless shoe Payless Shoes which are +just two chain retails stores and they + + align:start position:0% +just two chain retails stores and they + + + align:start position:0% +just two chain retails stores and they +find that there's substantial + + align:start position:0% +find that there's substantial + + + align:start position:0% +find that there's substantial +differences in the skus carried at the + + align:start position:0% +differences in the skus carried at the + + + align:start position:0% +differences in the skus carried at the +different stores now you know they don't + + align:start position:0% +different stores now you know they don't + + + align:start position:0% +different stores now you know they don't +know what they don't really have enough + + align:start position:0% +know what they don't really have enough + + + align:start position:0% +know what they don't really have enough +data to say whether it's just completely + + align:start position:0% +data to say whether it's just completely + + + align:start position:0% +data to say whether it's just completely +random or how much of it is this store + + align:start position:0% +random or how much of it is this store + + + align:start position:0% +random or how much of it is this store +carrying this store you know carrying + + align:start position:0% +carrying this store you know carrying + + + align:start position:0% +carrying this store you know carrying +boots and this one carrying sandals or + + align:start position:0% +boots and this one carrying sandals or + + + align:start position:0% +boots and this one carrying sandals or +this one having just different brands + + align:start position:0% +this one having just different brands + + + align:start position:0% +this one having just different brands +from the others but what they find is + + align:start position:0% +from the others but what they find is + + + align:start position:0% +from the others but what they find is +that like at especially at the Macy's + + align:start position:0% +that like at especially at the Macy's + + + align:start position:0% +that like at especially at the Macy's +there are almost no shoes that all the + + align:start position:0% +there are almost no shoes that all the + + + align:start position:0% +there are almost no shoes that all the +Macy's have different Macy's just have + + align:start position:0% +Macy's have different Macy's just have + + + align:start position:0% +Macy's have different Macy's just have +different shoes there are a lot of them + + align:start position:0% +different shoes there are a lot of them + + + align:start position:0% +different shoes there are a lot of them +that shoes that are only found in one or + + align:start position:0% +that shoes that are only found in one or + + + align:start position:0% +that shoes that are only found in one or +two stores very few that are found in + + align:start position:0% +two stores very few that are found in + + + align:start position:0% +two stores very few that are found in +100% of stores at the pays there are a + + align:start position:0% +100% of stores at the pays there are a + + + align:start position:0% +100% of stores at the pays there are a +lot of store shoes that are found in + + align:start position:0% +lot of store shoes that are found in + + + align:start position:0% +lot of store shoes that are found in +every pay and a lot of shoes that are + + align:start position:0% +every pay and a lot of shoes that are + + + align:start position:0% +every pay and a lot of shoes that are +found in like one or two pay lses + + align:start position:0% +found in like one or two pay lses + + + align:start position:0% +found in like one or two pay lses +um okay anyway so um how do they + + align:start position:0% +um okay anyway so um how do they + + + align:start position:0% +um okay anyway so um how do they +estimate you know so that what they want + + align:start position:0% +estimate you know so that what they want + + + align:start position:0% +estimate you know so that what they want +to do is + + align:start position:0% +to do is + + + align:start position:0% +to do is +estimate how important is this variation + + align:start position:0% +estimate how important is this variation + + + align:start position:0% +estimate how important is this variation +in consumer preferences and to estimate + + align:start position:0% +in consumer preferences and to estimate + + + align:start position:0% +in consumer preferences and to estimate +how important would it if if stores just + + align:start position:0% +how important would it if if stores just + + + align:start position:0% +how important would it if if stores just +match their local preferences would + + align:start position:0% +match their local preferences would + + + align:start position:0% +match their local preferences would +stores be able to sort of get most of + + align:start position:0% +stores be able to sort of get most of + + + align:start position:0% +stores be able to sort of get most of +the benefits that you get from Amazon + + align:start position:0% +the benefits that you get from Amazon + + + align:start position:0% +the benefits that you get from Amazon +um so what they do is a demand + + align:start position:0% +um so what they do is a demand + + + align:start position:0% +um so what they do is a demand +estimation it's going to be sort of a + + align:start position:0% +estimation it's going to be sort of a + + + align:start position:0% +estimation it's going to be sort of a +standard kind of nested Lo of demand so + + align:start position:0% +standard kind of nested Lo of demand so + + + align:start position:0% +standard kind of nested Lo of demand so +this is utility customer I location L + + align:start position:0% +this is utility customer I location L + + + align:start position:0% +this is utility customer I location L +buying product J it's going to be a mean + + align:start position:0% +buying product J it's going to be a mean + + + align:start position:0% +buying product J it's going to be a mean +utility of product J in location + + align:start position:0% +utility of product J in location + + + align:start position:0% +utility of product J in location +L um plus this sort of nestal loan + + align:start position:0% +L um plus this sort of nestal loan + + + align:start position:0% +L um plus this sort of nestal loan +models there's a shock uh you have this + + align:start position:0% +models there's a shock uh you have this + + + align:start position:0% +models there's a shock uh you have this +idiosyncratic preference of a customer + + align:start position:0% +idiosyncratic preference of a customer + + + align:start position:0% +idiosyncratic preference of a customer +for um all products in category J so if + + align:start position:0% +for um all products in category J so if + + + align:start position:0% +for um all products in category J so if +I'm looking for snow boots I have a snow + + align:start position:0% +I'm looking for snow boots I have a snow + + + align:start position:0% +I'm looking for snow boots I have a snow +boot specific shock and then a weight I + + align:start position:0% +boot specific shock and then a weight I + + + align:start position:0% +boot specific shock and then a weight I +have sort of two shocks one is the + + align:start position:0% +have sort of two shocks one is the + + + align:start position:0% +have sort of two shocks one is the +category specific shock and then one is + + align:start position:0% +category specific shock and then one is + + + align:start position:0% +category specific shock and then one is +the brand specific shock and they're + + align:start position:0% +the brand specific shock and they're + + + align:start position:0% +the brand specific shock and they're +going to estimate this Lambda parameter + + align:start position:0% +going to estimate this Lambda parameter + + + align:start position:0% +going to estimate this Lambda parameter +so they can tell whether people shocks + + align:start position:0% +so they can tell whether people shocks + + + align:start position:0% +so they can tell whether people shocks +are mostly category specific or mostly + + align:start position:0% +are mostly category specific or mostly + + + align:start position:0% +are mostly category specific or mostly +product + + align:start position:0% +product + + + align:start position:0% +product +specific and then what they're going to + + align:start position:0% +specific and then what they're going to + + + align:start position:0% +specific and then what they're going to +assume is that the um mean utility + + align:start position:0% +assume is that the um mean utility + + + align:start position:0% +assume is that the um mean utility +provided by product J and location L is + + align:start position:0% +provided by product J and location L is + + + align:start position:0% +provided by product J and location L is +a function of the product + + align:start position:0% +a function of the product + + + align:start position:0% +a function of the product +characteristics a function of the + + align:start position:0% +characteristics a function of the + + + align:start position:0% +characteristics a function of the +product price and then this other um Ze + + align:start position:0% +product price and then this other um Ze + + + align:start position:0% +product price and then this other um Ze +of LJ term which is + + align:start position:0% +of LJ term which is + + + align:start position:0% +of LJ term which is +the you know that's the sort of + + align:start position:0% +the you know that's the sort of + + + align:start position:0% +the you know that's the sort of +idiosyncratic preference for this + + align:start position:0% +idiosyncratic preference for this + + + align:start position:0% +idiosyncratic preference for this +product in location + + align:start position:0% +product in location + + + align:start position:0% +product in location +L uh they don't have the temperature + + align:start position:0% +L uh they don't have the temperature + + + align:start position:0% +L uh they don't have the temperature +here so like the people in Florida don't + + align:start position:0% +here so like the people in Florida don't + + + align:start position:0% +here so like the people in Florida don't +like boots would be here people in + + align:start position:0% +like boots would be here people in + + + align:start position:0% +like boots would be here people in +Hawaii like sandals would be here uh but + + align:start position:0% +Hawaii like sandals would be here uh but + + + align:start position:0% +Hawaii like sandals would be here uh but +then you know there's also you could + + align:start position:0% +then you know there's also you could + + + align:start position:0% +then you know there's also you could +imagine there's also just sort of these + + align:start position:0% +imagine there's also just sort of these + + + align:start position:0% +imagine there's also just sort of these +sort of mayonnaise like preferences like + + align:start position:0% +sort of mayonnaise like preferences like + + + align:start position:0% +sort of mayonnaise like preferences like +there's just Uggs boots are popular in + + align:start position:0% +there's just Uggs boots are popular in + + + align:start position:0% +there's just Uggs boots are popular in +New England they're unfashionable in + + align:start position:0% +New England they're unfashionable in + + + align:start position:0% +New England they're unfashionable in +California or this brand of shoes is + + align:start position:0% +California or this brand of shoes is + + + align:start position:0% +California or this brand of shoes is +popular here it's not popular here all + + align:start position:0% +popular here it's not popular here all + + + align:start position:0% +popular here it's not popular here all +of that would go into the + + align:start position:0% +of that would go into the + + + align:start position:0% +of that would go into the +zjs + + align:start position:0% +zjs + + + align:start position:0% +zjs +um uh a real challenge to estimating + + align:start position:0% +um uh a real challenge to estimating + + + align:start position:0% +um uh a real challenge to estimating +demand is that + + align:start position:0% +demand is that + + + align:start position:0% +demand is that +um most products you know like there's a + + align:start position:0% +um most products you know like there's a + + + align:start position:0% +um most products you know like there's a +very very large number of shoes in the + + align:start position:0% +very very large number of shoes in the + + + align:start position:0% +very very large number of shoes in the +world um and it turns out that most + + align:start position:0% +world um and it turns out that most + + + align:start position:0% +world um and it turns out that most +shoes in most cities in most months have + + align:start position:0% +shoes in most cities in most months have + + + align:start position:0% +shoes in most cities in most months have +zero + + align:start position:0% +zero + + + align:start position:0% +zero +sales and so dealing with quantity data + + align:start position:0% +sales and so dealing with quantity data + + + align:start position:0% +sales and so dealing with quantity data +when you have zeros is very difficult + + align:start position:0% +when you have zeros is very difficult + + + align:start position:0% +when you have zeros is very difficult +you know like right if you remember that + + align:start position:0% +you know like right if you remember that + + + align:start position:0% +you know like right if you remember that +one of the things we you know standard + + align:start position:0% +one of the things we you know standard + + + align:start position:0% +one of the things we you know standard +approaches people do in the that like + + align:start position:0% +approaches people do in the that like + + + align:start position:0% +approaches people do in the that like +lit demand estimation is you sort of + + align:start position:0% +lit demand estimation is you sort of + + + align:start position:0% +lit demand estimation is you sort of +have you know log of the share product J + + align:start position:0% +have you know log of the share product J + + + align:start position:0% +have you know log of the share product J +minus log of the share the outside good + + align:start position:0% +minus log of the share the outside good + + + align:start position:0% +minus log of the share the outside good +was XJ beta minus Alpha PJ something + + align:start position:0% +was XJ beta minus Alpha PJ something + + + align:start position:0% +was XJ beta minus Alpha PJ something +like that you sort of invert the you + + align:start position:0% +like that you sort of invert the you + + + align:start position:0% +like that you sort of invert the you +sort of convert from the market sh you + + align:start position:0% +sort of convert from the market sh you + + + align:start position:0% +sort of convert from the market sh you +convert to the market shares to get back + + align:start position:0% +convert to the market shares to get back + + + align:start position:0% +convert to the market shares to get back +to the product characteristics and then + + align:start position:0% +to the product characteristics and then + + + align:start position:0% +to the product characteristics and then +you can run IV regressions to estimate + + align:start position:0% +you can run IV regressions to estimate + + + align:start position:0% +you can run IV regressions to estimate +demand you know you can't do these sort + + align:start position:0% +demand you know you can't do these sort + + + align:start position:0% +demand you know you can't do these sort +of log Transformations when you have a + + align:start position:0% +of log Transformations when you have a + + + align:start position:0% +of log Transformations when you have a +whole bunch of zeros in your data um and + + align:start position:0% +whole bunch of zeros in your data um and + + + align:start position:0% +whole bunch of zeros in your data um and +so what do you do when you have a whole + + align:start position:0% +so what do you do when you have a whole + + + align:start position:0% +so what do you do when you have a whole +bunch of zeros in your data anyway what + + align:start position:0% +bunch of zeros in your data anyway what + + + align:start position:0% +bunch of zeros in your data anyway what +they do in this paper is you know + + align:start position:0% +they do in this paper is you know + + + align:start position:0% +they do in this paper is you know +discuss a GMM approach to sort of try to + + align:start position:0% +discuss a GMM approach to sort of try to + + + align:start position:0% +discuss a GMM approach to sort of try to +deal with all the zeros and and you know + + align:start position:0% +deal with all the zeros and and you know + + + align:start position:0% +deal with all the zeros and and you know +you don't want to Al you know you also + + align:start position:0% +you don't want to Al you know you also + + + align:start position:0% +you don't want to Al you know you also +don't want to throw out another thing + + align:start position:0% +don't want to throw out another thing + + + align:start position:0% +don't want to throw out another thing +people do sometimes is just throw out + + align:start position:0% +people do sometimes is just throw out + + + align:start position:0% +people do sometimes is just throw out +all the zeros you clearly don't want to + + align:start position:0% +all the zeros you clearly don't want to + + + align:start position:0% +all the zeros you clearly don't want to +throw out all the zeros because like the + + align:start position:0% +throw out all the zeros because like the + + + align:start position:0% +throw out all the zeros because like the +goods that have zero sales in one month + + align:start position:0% +goods that have zero sales in one month + + + align:start position:0% +goods that have zero sales in one month +will have positive sales in the next + + align:start position:0% +will have positive sales in the next + + + align:start position:0% +will have positive sales in the next +month they all have positive mean + + align:start position:0% +month they all have positive mean + + + align:start position:0% +month they all have positive mean +utilities you don't want to remove them + + align:start position:0% +utilities you don't want to remove them + + + align:start position:0% +utilities you don't want to remove them +and say no one wants to buy from those + + align:start position:0% +and say no one wants to buy from those + + + align:start position:0% +and say no one wants to buy from those +goods um in particular what they note is + + align:start position:0% +goods um in particular what they note is + + + align:start position:0% +goods um in particular what they note is +that um + + align:start position:0% +that um + + + align:start position:0% +that um +you know the number of shoes that are + + align:start position:0% +you know the number of shoes that are + + + align:start position:0% +you know the number of shoes that are +sold by this online website in in a + + align:start position:0% +sold by this online website in in a + + + align:start position:0% +sold by this online website in in a +particular City in a particular month is + + align:start position:0% +particular City in a particular month is + + + align:start position:0% +particular City in a particular month is +smaller than the inventory of a large + + align:start position:0% +smaller than the inventory of a large + + + align:start position:0% +smaller than the inventory of a large +shoe + + align:start position:0% +shoe + + + align:start position:0% +shoe +store so if you actually sort of were to + + align:start position:0% +store so if you actually sort of were to + + + align:start position:0% +store so if you actually sort of were to +take the realized shoe sales and say + + align:start position:0% +take the realized shoe sales and say + + + align:start position:0% +take the realized shoe sales and say +those people's Deltas are only based on + + align:start position:0% +those people's Deltas are only based on + + + align:start position:0% +those people's Deltas are only based on +the shoes that actually got bought what + + align:start position:0% +the shoes that actually got bought what + + + align:start position:0% +the shoes that actually got bought what +you'd conclude is that a single physical + + align:start position:0% +you'd conclude is that a single physical + + + align:start position:0% +you'd conclude is that a single physical +store could actually Supply the entire + + align:start position:0% +store could actually Supply the entire + + + align:start position:0% +store could actually Supply the entire +Market uh and so it's just it's very + + align:start position:0% +Market uh and so it's just it's very + + + align:start position:0% +Market uh and so it's just it's very +important to correctly deal with all of + + align:start position:0% +important to correctly deal with all of + + + align:start position:0% +important to correctly deal with all of +these shoes that are in the store and + + align:start position:0% +these shoes that are in the store and + + + align:start position:0% +these shoes that are in the store and +have zero sales in a month but you know + + align:start position:0% +have zero sales in a month but you know + + + align:start position:0% +have zero sales in a month but you know +people are buying like you just have + + align:start position:0% +people are buying like you just have + + + align:start position:0% +people are buying like you just have +these many products all with like a + + align:start position:0% +these many products all with like a + + + align:start position:0% +these many products all with like a +fraction of expected sales but those are + + align:start position:0% +fraction of expected sales but those are + + + align:start position:0% +fraction of expected sales but those are +what people buy among and so they have + + align:start position:0% +what people buy among and so they have + + + align:start position:0% +what people buy among and so they have +to deal with the zeros anyway you know + + align:start position:0% +to deal with the zeros anyway you know + + + align:start position:0% +to deal with the zeros anyway you know +there + + align:start position:0% +there + + + align:start position:0% +there +are one thing you'll notice in the paper + + align:start position:0% +are one thing you'll notice in the paper + + + align:start position:0% +are one thing you'll notice in the paper +like they spent a while talking about + + align:start position:0% +like they spent a while talking about + + + align:start position:0% +like they spent a while talking about +how to deal with demand estimation when + + align:start position:0% +how to deal with demand estimation when + + + align:start position:0% +how to deal with demand estimation when +you have lots of zeros uh if you ever + + align:start position:0% +you have lots of zeros uh if you ever + + + align:start position:0% +you have lots of zeros uh if you ever +have a paper you're trying to do demand + + align:start position:0% +have a paper you're trying to do demand + + + align:start position:0% +have a paper you're trying to do demand +estimation with lots of zeros I'd + + align:start position:0% +estimation with lots of zeros I'd + + + align:start position:0% +estimation with lots of zeros I'd +recommend read you know they discuss + + align:start position:0% +recommend read you know they discuss + + + align:start position:0% +recommend read you know they discuss +sort of their method and other methods + + align:start position:0% +sort of their method and other methods + + + align:start position:0% +sort of their method and other methods +of people able to deal with zeros I + + align:start position:0% +of people able to deal with zeros I + + + align:start position:0% +of people able to deal with zeros I +think theirs is thought to be a fairly + + align:start position:0% +think theirs is thought to be a fairly + + + align:start position:0% +think theirs is thought to be a fairly +good method for doing demand estimation + + align:start position:0% +good method for doing demand estimation + + + align:start position:0% +good method for doing demand estimation +when you have a whole bunch of zeros + + align:start position:0% +when you have a whole bunch of zeros + + + align:start position:0% +when you have a whole bunch of zeros +um but so anyway it it's the basic idea + + align:start position:0% +um but so anyway it it's the basic idea + + + align:start position:0% +um but so anyway it it's the basic idea +is they aggregate sales to the location + + align:start position:0% +is they aggregate sales to the location + + + align:start position:0% +is they aggregate sales to the location +month level they have 213 + + align:start position:0% +month level they have 213 + + + align:start position:0% +month level they have 213 +locations uh most of the 213 locations + + align:start position:0% +locations uh most of the 213 locations + + + align:start position:0% +locations uh most of the 213 locations +are um metropolitan areas but then in + + align:start position:0% +are um metropolitan areas but then in + + + align:start position:0% +are um metropolitan areas but then in +addition they have sort of so they have + + align:start position:0% +addition they have sort of so they have + + + align:start position:0% +addition they have sort of so they have +sort of each metropolitan area as a + + align:start position:0% +sort of each metropolitan area as a + + + align:start position:0% +sort of each metropolitan area as a +location observation and then they have + + align:start position:0% +location observation and then they have + + + align:start position:0% +location observation and then they have +the rest of a state not in metropolitan + + align:start position:0% +the rest of a state not in metropolitan + + + align:start position:0% +the rest of a state not in metropolitan +areas as an observation uh anyway so + + align:start position:0% +areas as an observation uh anyway so + + + align:start position:0% +areas as an observation uh anyway so +they have 213 different + + align:start position:0% +they have 213 different + + + align:start position:0% +they have 213 different +locations they sort of do something + + align:start position:0% +locations they sort of do something + + + align:start position:0% +locations they sort of do something +that's kind of like a blp estimation + + align:start position:0% +that's kind of like a blp estimation + + + align:start position:0% +that's kind of like a blp estimation +except dealing with the zeros so they + + align:start position:0% +except dealing with the zeros so they + + + align:start position:0% +except dealing with the zeros so they +aggregate sales um they do something + + align:start position:0% +aggregate sales um they do something + + + align:start position:0% +aggregate sales um they do something +very much like you know these if you + + align:start position:0% +very much like you know these if you + + + align:start position:0% +very much like you know these if you +remember back in tobias's lecture your + + align:start position:0% +remember back in tobias's lecture your + + + align:start position:0% +remember back in tobias's lecture your +sort of blp instruments for Price are + + align:start position:0% +sort of blp instruments for Price are + + + align:start position:0% +sort of blp instruments for Price are +some function of the characteristics of + + align:start position:0% +some function of the characteristics of + + + align:start position:0% +some function of the characteristics of +all the competing Brands so they have + + align:start position:0% +all the competing Brands so they have + + + align:start position:0% +all the competing Brands so they have +like a you know I not a very convincing + + align:start position:0% +like a you know I not a very convincing + + + align:start position:0% +like a you know I not a very convincing +instrumentation strategy but that's what + + align:start position:0% +instrumentation strategy but that's what + + + align:start position:0% +instrumentation strategy but that's what +what's available so they have like a blp + + align:start position:0% +what's available so they have like a blp + + + align:start position:0% +what's available so they have like a blp +style instrumentation strategy dealing + + align:start position:0% +style instrumentation strategy dealing + + + align:start position:0% +style instrumentation strategy dealing +with the zeros and it is it's not a pure + + align:start position:0% +with the zeros and it is it's not a pure + + + align:start position:0% +with the zeros and it is it's not a pure +cross-section because you know there's + + align:start position:0% +cross-section because you know there's + + + align:start position:0% +cross-section because you know there's +price variation because the prices vary + + align:start position:0% +price variation because the prices vary + + + align:start position:0% +price variation because the prices vary +across months and you can see when this + + align:start position:0% +across months and you can see when this + + + align:start position:0% +across months and you can see when this +shoe is on sale and some month do sales + + align:start position:0% +shoe is on sale and some month do sales + + + align:start position:0% +shoe is on sale and some month do sales +go up um product reviews are also time + + align:start position:0% +go up um product reviews are also time + + + align:start position:0% +go up um product reviews are also time +varying shoes come out they have no + + align:start position:0% +varying shoes come out they have no + + + align:start position:0% +varying shoes come out they have no +reviews over time they build up reviews + + align:start position:0% +reviews over time they build up reviews + + + align:start position:0% +reviews over time they build up reviews +obviously higher reviews are good for + + align:start position:0% +obviously higher reviews are good for + + + align:start position:0% +obviously higher reviews are good for +sales it turns out though also um zero + + align:start position:0% +sales it turns out though also um zero + + + align:start position:0% +sales it turns out though also um zero +reviews are good for sale are positively + + align:start position:0% +reviews are good for sale are positively + + + align:start position:0% +reviews are good for sale are positively +associated with sales as well uh and + + align:start position:0% +associated with sales as well uh and + + + align:start position:0% +associated with sales as well uh and +this may be because zero sales means + + align:start position:0% +this may be because zero sales means + + + align:start position:0% +this may be because zero sales means +it's a zero reviews means it's a brand + + align:start position:0% +it's a zero reviews means it's a brand + + + align:start position:0% +it's a zero reviews means it's a brand +new product that's just being introduced + + align:start position:0% +new product that's just being introduced + + + align:start position:0% +new product that's just being introduced +with the latest fashion or that's being + + align:start position:0% +with the latest fashion or that's being + + + align:start position:0% +with the latest fashion or that's being +advertised or something like that um + + align:start position:0% +advertised or something like that um + + + align:start position:0% +advertised or something like that um +anyway and then the product set is also + + align:start position:0% +anyway and then the product set is also + + + align:start position:0% +anyway and then the product set is also +time varying um so anyway with all that + + align:start position:0% +time varying um so anyway with all that + + + align:start position:0% +time varying um so anyway with all that +they're able to sort of + + align:start position:0% +they're able to sort of + + + align:start position:0% +they're able to sort of +estimate all these C efficients and they + + align:start position:0% +estimate all these C efficients and they + + + align:start position:0% +estimate all these C efficients and they +can estimate sort of a distribution of + + align:start position:0% +can estimate sort of a distribution of + + + align:start position:0% +can estimate sort of a distribution of +the Delta + + align:start position:0% +the Delta + + + align:start position:0% +the Delta +ljs and the you know Delta ljs indicate + + align:start position:0% +ljs and the you know Delta ljs indicate + + + align:start position:0% +ljs and the you know Delta ljs indicate +that there is a lot of cross market + + align:start position:0% +that there is a lot of cross market + + + align:start position:0% +that there is a lot of cross market +heterogenity and preferences uh and you + + align:start position:0% +heterogenity and preferences uh and you + + + align:start position:0% +heterogenity and preferences uh and you +know I you you have to have faith that + + align:start position:0% +know I you you have to have faith that + + + align:start position:0% +know I you you have to have faith that +they're dealing with the zero appropri + + align:start position:0% +they're dealing with the zero appropri + + + align:start position:0% +they're dealing with the zero appropri +to deal with it it's not just in some + + align:start position:0% +to deal with it it's not just in some + + + align:start position:0% +to deal with it it's not just in some +markets people buy these these shoes + + align:start position:0% +markets people buy these these shoes + + + align:start position:0% +markets people buy these these shoes +actually have sales and some markets + + align:start position:0% +actually have sales and some markets + + + align:start position:0% +actually have sales and some markets +these have actually have sales but I + + align:start position:0% +these have actually have sales but I + + + align:start position:0% +these have actually have sales but I +think they've done a fairly good job of + + align:start position:0% +think they've done a fairly good job of + + + align:start position:0% +think they've done a fairly good job of +trying to argue that no there's + + align:start position:0% +trying to argue that no there's + + + align:start position:0% +trying to argue that no there's +underlying cross-sectional variation in + + align:start position:0% +underlying cross-sectional variation in + + + align:start position:0% +underlying cross-sectional variation in +the cities to purchase different shoes + + align:start position:0% +the cities to purchase different shoes + + + align:start position:0% +the cities to purchase different shoes +in different places and again I think + + align:start position:0% +in different places and again I think + + + align:start position:0% +in different places and again I think +some of that is like the Sho the boots + + align:start position:0% +some of that is like the Sho the boots + + + align:start position:0% +some of that is like the Sho the boots +versus sandals approach and some of that + + align:start position:0% +versus sandals approach and some of that + + + align:start position:0% +versus sandals approach and some of that +is just you know shoes are a fashion + + align:start position:0% +is just you know shoes are a fashion + + + align:start position:0% +is just you know shoes are a fashion +good and there are brands of sneakers + + align:start position:0% +good and there are brands of sneakers + + + align:start position:0% +good and there are brands of sneakers +brands of shoes brands of whatever that + + align:start position:0% +brands of shoes brands of whatever that + + + align:start position:0% +brands of shoes brands of whatever that +are more and less fashionable in + + align:start position:0% +are more and less fashionable in + + + align:start position:0% +are more and less fashionable in +different cities for whatever reason + + align:start position:0% +different cities for whatever reason + + + align:start position:0% +different cities for whatever reason +this has become something people wear + + align:start position:0% +this has become something people wear + + + align:start position:0% +this has become something people wear +and and people will to pay more for + + align:start position:0% +and and people will to pay more for + + + align:start position:0% +and and people will to pay more for +those okay um so how do they estimate + + align:start position:0% +those okay um so how do they estimate + + + align:start position:0% +those okay um so how do they estimate +the gains from product iety um to + + align:start position:0% +the gains from product iety um to + + + align:start position:0% +the gains from product iety um to +estimate gains from product variety this + + align:start position:0% +estimate gains from product variety this + + + align:start position:0% +estimate gains from product variety this +is done with a + + align:start position:0% +is done with a + + + align:start position:0% +is done with a +counterfactual so you know they know all + + align:start position:0% +counterfactual so you know they know all + + + align:start position:0% +counterfactual so you know they know all +the sales that zapo or whatever the + + align:start position:0% +the sales that zapo or whatever the + + + align:start position:0% +the sales that zapo or whatever the +retailer is made uh and then they think + + align:start position:0% +retailer is made uh and then they think + + + align:start position:0% +retailer is made uh and then they think +about a counterfactual world where + + align:start position:0% +about a counterfactual world where + + + align:start position:0% +about a counterfactual world where +instead of choosing from all the shoes + + align:start position:0% +instead of choosing from all the shoes + + + align:start position:0% +instead of choosing from all the shoes +at zapo people could only choose from a + + align:start position:0% +at zapo people could only choose from a + + + align:start position:0% +at zapo people could only choose from a +limited Supply uh what do they do for + + align:start position:0% +limited Supply uh what do they do for + + + align:start position:0% +limited Supply uh what do they do for +the limited Supply well the first thing + + align:start position:0% +the limited Supply well the first thing + + + align:start position:0% +the limited Supply well the first thing +they do is they use the data on the + + align:start position:0% +they do is they use the data on the + + + align:start position:0% +they do is they use the data on the +Macy's and Payless shoe stores to + + align:start position:0% +Macy's and Payless shoe stores to + + + align:start position:0% +Macy's and Payless shoe stores to +estimate the total number of products + + align:start position:0% +estimate the total number of products + + + align:start position:0% +estimate the total number of products +available in each market as a function + + align:start position:0% +available in each market as a function + + + align:start position:0% +available in each market as a function +of the population so they would be doing + + align:start position:0% +of the population so they would be doing + + + align:start position:0% +of the population so they would be doing +how many different brands of shoes are + + align:start position:0% +how many different brands of shoes are + + + align:start position:0% +how many different brands of shoes are +available in Boston which you get by + + align:start position:0% +available in Boston which you get by + + + align:start position:0% +available in Boston which you get by +looking at the overlap of all the Macy's + + align:start position:0% +looking at the overlap of all the Macy's + + + align:start position:0% +looking at the overlap of all the Macy's +in Boston and the overlap of the Macy's + + align:start position:0% +in Boston and the overlap of the Macy's + + + align:start position:0% +in Boston and the overlap of the Macy's +in Boston with the Payless shoe stores + + align:start position:0% +in Boston with the Payless shoe stores + + + align:start position:0% +in Boston with the Payless shoe stores +in Boston and then they have Census Data + + align:start position:0% +in Boston and then they have Census Data + + + align:start position:0% +in Boston and then they have Census Data +knowing how many and shoe stores there + + align:start position:0% +knowing how many and shoe stores there + + + align:start position:0% +knowing how many and shoe stores there +are in Boston how large they are in + + align:start position:0% +are in Boston how large they are in + + + align:start position:0% +are in Boston how large they are in +Boston they assume that they have the + + align:start position:0% +Boston they assume that they have the + + + align:start position:0% +Boston they assume that they have the +same overlap as as they're seeing in the + + align:start position:0% +same overlap as as they're seeing in the + + + align:start position:0% +same overlap as as they're seeing in the +May season pay lesses and there started + + align:start position:0% +May season pay lesses and there started + + + align:start position:0% +May season pay lesses and there started +trying to estimate how many total shoes + + align:start position:0% +trying to estimate how many total shoes + + + align:start position:0% +trying to estimate how many total shoes +are are there in the Boston area that + + align:start position:0% +are are there in the Boston area that + + + align:start position:0% +are are there in the Boston area that +you can buy at physical retail + + align:start position:0% +you can buy at physical retail + + + align:start position:0% +you can buy at physical retail +stores um obviously that's a bit of an + + align:start position:0% +stores um obviously that's a bit of an + + + align:start position:0% +stores um obviously that's a bit of an +aggressive assumption and that that + + align:start position:0% +aggressive assumption and that that + + + align:start position:0% +aggressive assumption and that that +assuming that people could actually know + + align:start position:0% +assuming that people could actually know + + + align:start position:0% +assuming that people could actually know +which local Boston shoe store to go to + + align:start position:0% +which local Boston shoe store to go to + + + align:start position:0% +which local Boston shoe store to go to +to buy whatever particular brand of + + align:start position:0% +to buy whatever particular brand of + + + align:start position:0% +to buy whatever particular brand of +boots they want um and then what they + + align:start position:0% +boots they want um and then what they + + + align:start position:0% +boots they want um and then what they +assume is that offline + + align:start position:0% +assume is that offline + + + align:start position:0% +assume is that offline +consumers have the choice of the NL + + align:start position:0% +consumers have the choice of the NL + + + align:start position:0% +consumers have the choice of the NL +products that have the highest Delta + + align:start position:0% +products that have the highest Delta + + + align:start position:0% +products that have the highest Delta +ljs uh to choose from so that the + + align:start position:0% +ljs uh to choose from so that the + + + align:start position:0% +ljs uh to choose from so that the +physical stores in each state or each + + align:start position:0% +physical stores in each state or each + + + align:start position:0% +physical stores in each state or each +City carry the most popular brands so + + align:start position:0% +City carry the most popular brands so + + + align:start position:0% +City carry the most popular brands so +again that's it's kind of an aggressive + + align:start position:0% +again that's it's kind of an aggressive + + + align:start position:0% +again that's it's kind of an aggressive +assumption in that you know local stores + + align:start position:0% +assumption in that you know local stores + + + align:start position:0% +assumption in that you know local stores +are tailoring their demand to what + + align:start position:0% +are tailoring their demand to what + + + align:start position:0% +are tailoring their demand to what +people want and they're tailoring it + + align:start position:0% +people want and they're tailoring it + + + align:start position:0% +people want and they're tailoring it +perfectly they're picking the most + + align:start position:0% +perfectly they're picking the most + + + align:start position:0% +perfectly they're picking the most +popular brands and so it it's both you + + align:start position:0% +popular brands and so it it's both you + + + align:start position:0% +popular brands and so it it's both you +know it's both we + + align:start position:0% +know it's both we + + + align:start position:0% +know it's both we +observe it's both we know where in this + + align:start position:0% +observe it's both we know where in this + + + align:start position:0% +observe it's both we know where in this +in this where to buy shoes physically + + align:start position:0% +in this where to buy shoes physically + + + align:start position:0% +in this where to buy shoes physically +depending on what we want which store to + + align:start position:0% +depending on what we want which store to + + + align:start position:0% +depending on what we want which store to +go to and we and the shoe stores are + + align:start position:0% +go to and we and the shoe stores are + + + align:start position:0% +go to and we and the shoe stores are +doing perfect tailoring and carrying the + + align:start position:0% +doing perfect tailoring and carrying the + + + align:start position:0% +doing perfect tailoring and carrying the +most popular shoes not making + + align:start position:0% +most popular shoes not making + + + align:start position:0% +most popular shoes not making +mistakes um but anyway so subject to + + align:start position:0% +mistakes um but anyway so subject to + + + align:start position:0% +mistakes um but anyway so subject to +that caveat uh es the paper suggests the + + align:start position:0% +that caveat uh es the paper suggests the + + + align:start position:0% +that caveat uh es the paper suggests the +sort of online product variety benefits + + align:start position:0% +sort of online product variety benefits + + + align:start position:0% +sort of online product variety benefits +are are much smaller than what BR yelson + + align:start position:0% +are are much smaller than what BR yelson + + + align:start position:0% +are are much smaller than what BR yelson +who and Smith said and they're much + + align:start position:0% +who and Smith said and they're much + + + align:start position:0% +who and Smith said and they're much +smaller in two different senses um the + + align:start position:0% +smaller in two different senses um the + + + align:start position:0% +smaller in two different senses um the +first is that if you look at the gain + + align:start position:0% +first is that if you look at the gain + + + align:start position:0% +first is that if you look at the gain +from product variety they argue that + + align:start position:0% +from product variety they argue that + + + align:start position:0% +from product variety they argue that +about half of the gain from product + + align:start position:0% +about half of the gain from product + + + align:start position:0% +about half of the gain from product +variety would um be provided Anyway by + + align:start position:0% +variety would um be provided Anyway by + + + align:start position:0% +variety would um be provided Anyway by +local stores by just having heterogenea + + align:start position:0% +local stores by just having heterogenea + + + align:start position:0% +local stores by just having heterogenea +in local stores so you if you think + + align:start position:0% +in local stores so you if you think + + + align:start position:0% +in local stores so you if you think +about this sort of + + align:start position:0% + + + + align:start position:0% + +Continuum you know let me do Brin nson + + align:start position:0% +Continuum you know let me do Brin nson + + + align:start position:0% +Continuum you know let me do Brin nson +who and Smith number so like you know so + + align:start position:0% +who and Smith number so like you know so + + + align:start position:0% +who and Smith number so like you know so +we + + align:start position:0% +we + + + align:start position:0% +we +have you know let's suppose we have so + + align:start position:0% +have you know let's suppose we have so + + + align:start position:0% +have you know let's suppose we have so +Brin holson who and Smith are looking at + + align:start position:0% +Brin holson who and Smith are looking at + + + align:start position:0% +Brin holson who and Smith are looking at +sort of what's the sort of consumer + + align:start position:0% +sort of what's the sort of consumer + + + align:start position:0% +sort of what's the sort of consumer +surplus from there being One Bookstore + + align:start position:0% +surplus from there being One Bookstore + + + align:start position:0% +surplus from there being One Bookstore +that has 100,000 + + align:start position:0% + + + + align:start position:0% + +titles and + + align:start position:0% +titles and + + + align:start position:0% +titles and +then we have this sort of + + align:start position:0% +then we have this sort of + + + align:start position:0% +then we have this sort of +Amazon with two million titles and + + align:start position:0% +Amazon with two million titles and + + + align:start position:0% +Amazon with two million titles and +they're arguing that you know this is 10 + + align:start position:0% +they're arguing that you know this is 10 + + + align:start position:0% +they're arguing that you know this is 10 +that this is like if this is one this is + + align:start position:0% +that this is like if this is one this is + + + align:start position:0% +that this is like if this is one this is +you know 10 you get 10 times the I'm + + align:start position:0% +you know 10 you get 10 times the I'm + + + align:start position:0% +you know 10 you get 10 times the I'm +putting the consumer surplus in this + + align:start position:0% +putting the consumer surplus in this + + + align:start position:0% +putting the consumer surplus in this +axis + + align:start position:0% +axis + + + align:start position:0% +axis +um and then what uh Quan and Williams + + align:start position:0% +um and then what uh Quan and Williams + + + align:start position:0% +um and then what uh Quan and Williams +are saying is that we have so + + align:start position:0% +are saying is that we have so + + + align:start position:0% +are saying is that we have so +is quanon Williams saying well our + + align:start position:0% +is quanon Williams saying well our + + + align:start position:0% +is quanon Williams saying well our +Benchmark is going to be not One + + align:start position:0% +Benchmark is going to be not One + + + align:start position:0% +Benchmark is going to be not One +Bookstore + + align:start position:0% +Bookstore + + + align:start position:0% +Bookstore +uh but you know all Boston + + align:start position:0% +uh but you know all Boston + + + align:start position:0% +uh but you know all Boston +bookstores they don't know what all + + align:start position:0% +bookstores they don't know what all + + + align:start position:0% +bookstores they don't know what all +Boston bookstores have but they just + + align:start position:0% +Boston bookstores have but they just + + + align:start position:0% +Boston bookstores have but they just +assume that the Boston bookstores have + + align:start position:0% +assume that the Boston bookstores have + + + align:start position:0% +assume that the Boston bookstores have +these nonoverlapping sets of books and + + align:start position:0% +these nonoverlapping sets of books and + + + align:start position:0% +these nonoverlapping sets of books and +and the non-overlapping sets of books + + align:start position:0% +and the non-overlapping sets of books + + + align:start position:0% +and the non-overlapping sets of books +you know tailored to what the MIT + + align:start position:0% +you know tailored to what the MIT + + + align:start position:0% +you know tailored to what the MIT +students want tailored to what everybody + + align:start position:0% +students want tailored to what everybody + + + align:start position:0% +students want tailored to what everybody +else in Boston wants uh and what they + + align:start position:0% +else in Boston wants uh and what they + + + align:start position:0% +else in Boston wants uh and what they +find is that you know the all + + align:start position:0% +find is that you know the all + + + align:start position:0% +find is that you know the all +they're well they do all shoe stores but + + align:start position:0% +they're well they do all shoe stores but + + + align:start position:0% +they're well they do all shoe stores but +the all shoe stores thing compared to + + align:start position:0% +the all shoe stores thing compared to + + + align:start position:0% +the all shoe stores thing compared to +one shoe store they're arguing that all + + align:start position:0% +one shoe store they're arguing that all + + + align:start position:0% +one shoe store they're arguing that all +shoe stores get you about half of the + + align:start position:0% +shoe stores get you about half of the + + + align:start position:0% +shoe stores get you about half of the +half of the way to the Amazon ranking so + + align:start position:0% +half of the way to the Amazon ranking so + + + align:start position:0% +half of the way to the Amazon ranking so +in some sense that Quan and Williams may + + align:start position:0% +in some sense that Quan and Williams may + + + align:start position:0% +in some sense that Quan and Williams may +be + + align:start position:0% +be + + + align:start position:0% +be +overstating the gains by you know by + + align:start position:0% +overstating the gains by you know by + + + align:start position:0% +overstating the gains by you know by +100% or + + align:start position:0% +100% or + + + align:start position:0% +100% or +something and so that's one point then + + align:start position:0% +something and so that's one point then + + + align:start position:0% +something and so that's one point then +the second point of the paper that you + + align:start position:0% +the second point of the paper that you + + + align:start position:0% +the second point of the paper that you +know is not emphasized as much just in + + align:start position:0% +know is not emphasized as much just in + + + align:start position:0% +know is not emphasized as much just in +the title and Inter is that they also + + align:start position:0% +the title and Inter is that they also + + + align:start position:0% +the title and Inter is that they also +find that + + align:start position:0% +find that + + + align:start position:0% +find that +um they also find that the uh gains from + + align:start position:0% +um they also find that the uh gains from + + + align:start position:0% +um they also find that the uh gains from +product variety are just much + + align:start position:0% +product variety are just much + + + align:start position:0% +product variety are just much +smaller uh than are reported elsewhere + + align:start position:0% +smaller uh than are reported elsewhere + + + align:start position:0% +smaller uh than are reported elsewhere +um so that whereas you + + align:start position:0% + + + + align:start position:0% + +know uh you + + align:start position:0% +know uh you + + + align:start position:0% +know uh you +know whereas um Bolson who and Smith are + + align:start position:0% +know whereas um Bolson who and Smith are + + + align:start position:0% +know whereas um Bolson who and Smith are +saying that sort of these gains are 10 + + align:start position:0% +saying that sort of these gains are 10 + + + align:start position:0% +saying that sort of these gains are 10 +times the gain from a 5% price cut uh + + align:start position:0% +times the gain from a 5% price cut uh + + + align:start position:0% +times the gain from a 5% price cut uh +what they find is that the gains in the + + align:start position:0% +what they find is that the gains in the + + + align:start position:0% +what they find is that the gains in the +shoe store data uh look like they're uh + + align:start position:0% +shoe store data uh look like they're uh + + + align:start position:0% +shoe store data uh look like they're uh +you know two times uh the benefit of + + align:start position:0% +you know two times uh the benefit of + + + align:start position:0% +you know two times uh the benefit of +a so anyway sorry this + + align:start position:0% +a so anyway sorry this + + + align:start position:0% +a so anyway sorry this +is if I make this one this is two so the + + align:start position:0% +is if I make this one this is two so the + + + align:start position:0% +is if I make this one this is two so the +the gain is just equivalent to a f the + + align:start position:0% +the gain is just equivalent to a f the + + + align:start position:0% +the gain is just equivalent to a f the +gain is like equivalent to a a 5% price + + align:start position:0% +gain is like equivalent to a a 5% price + + + align:start position:0% +gain is like equivalent to a a 5% price +cut so it's like the this number is here + + align:start position:0% +cut so it's like the this number is here + + + align:start position:0% +cut so it's like the this number is here +this number is here so what they're + + align:start position:0% +this number is here so what they're + + + align:start position:0% +this number is here so what they're +arguing is that the sort of actually no + + align:start position:0% +arguing is that the sort of actually no + + + align:start position:0% +arguing is that the sort of actually no +sorry take that back um it's this one + + align:start position:0% +sorry take that back um it's this one + + + align:start position:0% +sorry take that back um it's this one +compared to this one I think is roughly + + align:start position:0% +compared to this one I think is roughly + + + align:start position:0% +compared to this one I think is roughly +equivalent to a 5% price + + align:start position:0% +equivalent to a 5% price + + + align:start position:0% +equivalent to a 5% price +cut so what they're finding is that the + + align:start position:0% +cut so what they're finding is that the + + + align:start position:0% +cut so what they're finding is that the +gains from product variety are just much + + align:start position:0% +gains from product variety are just much + + + align:start position:0% +gains from product variety are just much +much smaller in shoes than Bolson who + + align:start position:0% +much smaller in shoes than Bolson who + + + align:start position:0% +much smaller in shoes than Bolson who +and Smith said they were in books uh and + + align:start position:0% +and Smith said they were in books uh and + + + align:start position:0% +and Smith said they were in books uh and +because the gains are so much smaller uh + + align:start position:0% +because the gains are so much smaller uh + + + align:start position:0% +because the gains are so much smaller uh +and you take out this sort of this thing + + align:start position:0% +and you take out this sort of this thing + + + align:start position:0% +and you take out this sort of this thing +is halfway there already what you're + + align:start position:0% +is halfway there already what you're + + + align:start position:0% +is halfway there already what you're +getting is the product variety gains are + + align:start position:0% +getting is the product variety gains are + + + align:start position:0% +getting is the product variety gains are +are really only like equivalent to a 5% + + align:start position:0% +are really only like equivalent to a 5% + + + align:start position:0% +are really only like equivalent to a 5% +price cut + + align:start position:0% +price cut + + + align:start position:0% +price cut +um so it's saying in at least in the + + align:start position:0% +um so it's saying in at least in the + + + align:start position:0% +um so it's saying in at least in the +shoe sense um product variety gains are + + align:start position:0% +shoe sense um product variety gains are + + + align:start position:0% +shoe sense um product variety gains are +you know 10 times smaller than you would + + align:start position:0% +you know 10 times smaller than you would + + + align:start position:0% +you know 10 times smaller than you would +have might have thought from the the + + align:start position:0% +have might have thought from the the + + + align:start position:0% +have might have thought from the the +Brin yson who and Smith paper and + + align:start position:0% +Brin yson who and Smith paper and + + + align:start position:0% +Brin yson who and Smith paper and +obviously you know is that because shoes + + align:start position:0% +obviously you know is that because shoes + + + align:start position:0% +obviously you know is that because shoes +are very different from books that's one + + align:start position:0% +are very different from books that's one + + + align:start position:0% +are very different from books that's one +possibility you know right like every + + align:start position:0% +possibility you know right like every + + + align:start position:0% +possibility you know right like every +book is very very different from every + + align:start position:0% +book is very very different from every + + + align:start position:0% +book is very very different from every +other book you could imagine once you've + + align:start position:0% +other book you could imagine once you've + + + align:start position:0% +other book you could imagine once you've +got a million shoes the ability to make + + align:start position:0% +got a million shoes the ability to make + + + align:start position:0% +got a million shoes the ability to make +a million first shoe that's very + + align:start position:0% +a million first shoe that's very + + + align:start position:0% +a million first shoe that's very +different from all existing shoes is + + align:start position:0% +different from all existing shoes is + + + align:start position:0% +different from all existing shoes is +very hard whereas every new book is just + + align:start position:0% +very hard whereas every new book is just + + + align:start position:0% +very hard whereas every new book is just +completely different text from every + + align:start position:0% +completely different text from every + + + align:start position:0% +completely different text from every +other book there may be more inherent + + align:start position:0% +other book there may be more inherent + + + align:start position:0% +other book there may be more inherent +Variety in books than there are in shoes + + align:start position:0% +Variety in books than there are in shoes + + + align:start position:0% +Variety in books than there are in shoes +uh but you know I think it may also be + + align:start position:0% +uh but you know I think it may also be + + + align:start position:0% +uh but you know I think it may also be +that um they may have done a better job + + align:start position:0% +that um they may have done a better job + + + align:start position:0% +that um they may have done a better job +of dealing with estimating what's true + + align:start position:0% +of dealing with estimating what's true + + + align:start position:0% +of dealing with estimating what's true +product variety versus spous product + + align:start position:0% +product variety versus spous product + + + align:start position:0% +product variety versus spous product +variety you know like + + align:start position:0% +variety you know like + + + align:start position:0% +variety you know like +the I don't know if I remember like I've + + align:start position:0% +the I don't know if I remember like I've + + + align:start position:0% +the I don't know if I remember like I've +started discussed like when you're doing + + align:start position:0% +started discussed like when you're doing + + + align:start position:0% +started discussed like when you're doing +trying to estimate consumer Variety in + + align:start position:0% +trying to estimate consumer Variety in + + + align:start position:0% +trying to estimate consumer Variety in +demand like consumer welfare from demand + + align:start position:0% +demand like consumer welfare from demand + + + align:start position:0% +demand like consumer welfare from demand +and you have heterogeneous products you + + align:start position:0% +and you have heterogeneous products you + + + align:start position:0% +and you have heterogeneous products you +know everyone's always doing this + + align:start position:0% +know everyone's always doing this + + + align:start position:0% +know everyone's always doing this +um uh XJ beta minus Alpha PJ plus + + align:start position:0% +um uh XJ beta minus Alpha PJ plus + + + align:start position:0% +um uh XJ beta minus Alpha PJ plus +Epsilon i + + align:start position:0% +Epsilon i + + + align:start position:0% +Epsilon i +j and they're always assuming these + + align:start position:0% +j and they're always assuming these + + + align:start position:0% +j and they're always assuming these +Epsilon I JS are loit distributed which + + align:start position:0% +Epsilon I JS are loit distributed which + + + align:start position:0% +Epsilon I JS are loit distributed which +has a fairly thick tail and that every + + align:start position:0% +has a fairly thick tail and that every + + + align:start position:0% +has a fairly thick tail and that every +Epsilon i j is independent of every + + align:start position:0% +Epsilon i j is independent of every + + + align:start position:0% +Epsilon i j is independent of every +other Epsilon i j um again right once + + align:start position:0% +other Epsilon i j um again right once + + + align:start position:0% +other Epsilon i j um again right once +you get to the the millionth different + + align:start position:0% +you get to the the millionth different + + + align:start position:0% +you get to the the millionth different +shoe is it really an Epsilon i j that's + + align:start position:0% +shoe is it really an Epsilon i j that's + + + align:start position:0% +shoe is it really an Epsilon i j that's +completely independent of your taste for + + align:start position:0% +completely independent of your taste for + + + align:start position:0% +completely independent of your taste for +every other shoe out there + + align:start position:0% +every other shoe out there + + + align:start position:0% +every other shoe out there +it's highly likely those epsilons are + + align:start position:0% +it's highly likely those epsilons are + + + align:start position:0% +it's highly likely those epsilons are +highly correlated across shoes at least + + align:start position:0% +highly correlated across shoes at least + + + align:start position:0% +highly correlated across shoes at least +by having the sort of you know they've + + align:start position:0% +by having the sort of you know they've + + + align:start position:0% +by having the sort of you know they've +they've got the sort of those category + + align:start position:0% +they've got the sort of those category + + + align:start position:0% +they've got the sort of those category +specific shocks by putting in the + + align:start position:0% +specific shocks by putting in the + + + align:start position:0% +specific shocks by putting in the +category specific shocks esing the + + align:start position:0% +category specific shocks esing the + + + align:start position:0% +category specific shocks esing the +magnitude and doing a careful job of + + align:start position:0% +magnitude and doing a careful job of + + + align:start position:0% +magnitude and doing a careful job of +thinking about the zeros they may be + + align:start position:0% +thinking about the zeros they may be + + + align:start position:0% +thinking about the zeros they may be +sort of avoiding overstating how big all + + align:start position:0% +sort of avoiding overstating how big all + + + align:start position:0% +sort of avoiding overstating how big all +these Epsilon IGS are and all the + + align:start position:0% +these Epsilon IGS are and all the + + + align:start position:0% +these Epsilon IGS are and all the +Surplus we're getting from all these new + + align:start position:0% +Surplus we're getting from all these new + + + align:start position:0% +Surplus we're getting from all these new +different + + align:start position:0% +different + + + align:start position:0% +different +products um and I guess one other paper + + align:start position:0% +products um and I guess one other paper + + + align:start position:0% +products um and I guess one other paper +I thought I'd mention one other thing I + + align:start position:0% +I thought I'd mention one other thing I + + + align:start position:0% +I thought I'd mention one other thing I +thought i' mentioned in the paper is + + align:start position:0% +thought i' mentioned in the paper is + + + align:start position:0% +thought i' mentioned in the paper is +that um they do also you know they know + + align:start position:0% +that um they do also you know they know + + + align:start position:0% +that um they do also you know they know +that Macy's and PS carry different shoes + + align:start position:0% +that Macy's and PS carry different shoes + + + align:start position:0% +that Macy's and PS carry different shoes +in different stores they ask how + + align:start position:0% +in different stores they ask how + + + align:start position:0% +in different stores they ask how +important is it for stores to tailor + + align:start position:0% +important is it for stores to tailor + + + align:start position:0% +important is it for stores to tailor +their selections and what they find is + + align:start position:0% +their selections and what they find is + + + align:start position:0% +their selections and what they find is +that you know there's a gain that firms + + align:start position:0% +that you know there's a gain that firms + + + align:start position:0% +that you know there's a gain that firms +should do it it's not that large the + + align:start position:0% +should do it it's not that large the + + + align:start position:0% +should do it it's not that large the +gain from customizing stores is + + align:start position:0% +gain from customizing stores is + + + align:start position:0% +gain from customizing stores is +estimated to be about + + align:start position:0% +estimated to be about + + + align:start position:0% +estimated to be about +6% in Revenue so you could just carry + + align:start position:0% +6% in Revenue so you could just carry + + + align:start position:0% +6% in Revenue so you could just carry +all the standard shoes or you could + + align:start position:0% +all the standard shoes or you could + + + align:start position:0% +all the standard shoes or you could +tailor the demand in your city you + + align:start position:0% +tailor the demand in your city you + + + align:start position:0% +tailor the demand in your city you +tailor the man in your city you get like + + align:start position:0% +tailor the man in your city you get like + + + align:start position:0% +tailor the man in your city you get like +6% more profit so you know it seems like + + align:start position:0% +6% more profit so you know it seems like + + + align:start position:0% +6% more profit so you know it seems like +it's worth doing firms should want to do + + align:start position:0% +it's worth doing firms should want to do + + + align:start position:0% +it's worth doing firms should want to do +this especially if they have thin profit + + align:start position:0% +this especially if they have thin profit + + + align:start position:0% +this especially if they have thin profit +margins but it's only it's boundedly + + align:start position:0% +margins but it's only it's boundedly + + + align:start position:0% +margins but it's only it's boundedly +tailoring is is boundedly + + align:start position:0% + + + + align:start position:0% + +profitable okay yeah was this paper like + + align:start position:0% +profitable okay yeah was this paper like + + + align:start position:0% +profitable okay yeah was this paper like +actually response to Amazon paper or was + + align:start position:0% +actually response to Amazon paper or was + + + align:start position:0% +actually response to Amazon paper or was +it just kind of dint because couldn't + + align:start position:0% +it just kind of dint because couldn't + + + align:start position:0% +it just kind of dint because couldn't +you just do the same exercise they did + + align:start position:0% +you just do the same exercise they did + + + align:start position:0% +you just do the same exercise they did +the Amazon paper both + + align:start position:0% +the Amazon paper both + + + align:start position:0% +the Amazon paper both +shoes change yeah so certainly they + + align:start position:0% +shoes change yeah so certainly they + + + align:start position:0% +shoes change yeah so certainly they +could have um + + align:start position:0% +could have um + + + align:start position:0% +could have um +uh you know so they actually have I + + align:start position:0% +uh you know so they actually have I + + + align:start position:0% +uh you know so they actually have I +don't know they're several different + + align:start position:0% +don't know they're several different + + + align:start position:0% +don't know they're several different +they do several different calculations + + align:start position:0% +they do several different calculations + + + align:start position:0% +they do several different calculations +in the paper like suppose we estimate + + align:start position:0% +in the paper like suppose we estimate + + + align:start position:0% +in the paper like suppose we estimate +demand this way suppose we estimate + + align:start position:0% +demand this way suppose we estimate + + + align:start position:0% +demand this way suppose we estimate +demand this way suppose we estimate + + align:start position:0% +demand this way suppose we estimate + + + align:start position:0% +demand this way suppose we estimate +demand this way you know in in some + + align:start position:0% +demand this way you know in in some + + + align:start position:0% +demand this way you know in in some +sense doing demand worse and worse and + + align:start position:0% +sense doing demand worse and worse and + + + align:start position:0% +sense doing demand worse and worse and +wor doing worse and worse demand + + align:start position:0% +wor doing worse and worse demand + + + align:start position:0% +wor doing worse and worse demand +estimation and the they do present + + align:start position:0% +estimation and the they do present + + + align:start position:0% +estimation and the they do present +several things if You' done this + + align:start position:0% +several things if You' done this + + + align:start position:0% +several things if You' done this +estimate instead you'd get numbers that + + align:start position:0% +estimate instead you'd get numbers that + + + align:start position:0% +estimate instead you'd get numbers that +are two times as big if you do these + + align:start position:0% +are two times as big if you do these + + + align:start position:0% +are two times as big if you do these +estimates instead you get things that + + align:start position:0% +estimates instead you get things that + + + align:start position:0% +estimates instead you get things that +are five times as big so they do get um + + align:start position:0% +are five times as big so they do get um + + + align:start position:0% +are five times as big so they do get um +you know it it's it's not exactly the + + align:start position:0% +you know it it's it's not exactly the + + + align:start position:0% +you know it it's it's not exactly the +same calculation as the Amazon data but + + align:start position:0% +same calculation as the Amazon data but + + + align:start position:0% +same calculation as the Amazon data but +they do something that's sort of more + + align:start position:0% +they do something that's sort of more + + + align:start position:0% +they do something that's sort of more +like the naive calculations where you + + align:start position:0% +like the naive calculations where you + + + align:start position:0% +like the naive calculations where you +sort of treat everything as National + + align:start position:0% +sort of treat everything as National + + + align:start position:0% +sort of treat everything as National +market shares and use low jit models and + + align:start position:0% +market shares and use low jit models and + + + align:start position:0% +market shares and use low jit models and +show that you can get things many times + + align:start position:0% +show that you can get things many times + + + align:start position:0% +show that you can get things many times +bigger than the estimates they've + + align:start position:0% +bigger than the estimates they've + + + align:start position:0% +bigger than the estimates they've +gotten + + align:start position:0% + + + + align:start position:0% + +um yeah I think you know these are the + + align:start position:0% +um yeah I think you know these are the + + + align:start position:0% +um yeah I think you know these are the +things that you know obviously you + + align:start position:0% +things that you know obviously you + + + align:start position:0% +things that you know obviously you +couldn't have done with the Amazon data + + align:start position:0% +couldn't have done with the Amazon data + + + align:start position:0% +couldn't have done with the Amazon data +like the the BR off didn't have anything + + align:start position:0% +like the the BR off didn't have anything + + + align:start position:0% +like the the BR off didn't have anything +about what is in local bookstores and + + align:start position:0% +about what is in local bookstores and + + + align:start position:0% +about what is in local bookstores and +how much overlap there is in local books + + align:start position:0% +how much overlap there is in local books + + + align:start position:0% +how much overlap there is in local books +across local bookstores and stuff like + + align:start position:0% +across local bookstores and stuff like + + + align:start position:0% +across local bookstores and stuff like +that + + align:start position:0% + + + + align:start position:0% + +um but certainly you know paper is very + + align:start position:0% +um but certainly you know paper is very + + + align:start position:0% +um but certainly you know paper is very +much written in in response to + + align:start position:0% +much written in in response to + + + align:start position:0% +much written in in response to +literature saying there are these big + + align:start position:0% +literature saying there are these big + + + align:start position:0% +literature saying there are these big +really big private really big product + + align:start position:0% +really big private really big product + + + align:start position:0% +really big private really big product +variety benefits and and it was you know + + align:start position:0% +variety benefits and and it was you know + + + align:start position:0% +variety benefits and and it was you know +I think it the paper's more about more + + align:start position:0% +I think it the paper's more about more + + + align:start position:0% +I think it the paper's more about more +about the benefits are smaller if + + align:start position:0% +about the benefits are smaller if + + + align:start position:0% +about the benefits are smaller if +because of the variety in retail then + + align:start position:0% +because of the variety in retail then + + + align:start position:0% +because of the variety in retail then +the benefits are smaller if you just do + + align:start position:0% +the benefits are smaller if you just do + + + align:start position:0% +the benefits are smaller if you just do +the econometrics correctly but I think + + align:start position:0% +the econometrics correctly but I think + + + align:start position:0% +the econometrics correctly but I think +it is about both + + align:start position:0% +it is about both + + + align:start position:0% +it is about both +um okay um so anyway uh final paper I + + align:start position:0% +um okay um so anyway uh final paper I + + + align:start position:0% +um okay um so anyway uh final paper I +want to cover this is a working paper + + align:start position:0% +want to cover this is a working paper + + + align:start position:0% +want to cover this is a working paper +that Sarah and I have um which I guess + + align:start position:0% +that Sarah and I have um which I guess + + + align:start position:0% +that Sarah and I have um which I guess +has you know two different motivations + + align:start position:0% +has you know two different motivations + + + align:start position:0% +has you know two different motivations +you know one is also this is a paper + + align:start position:0% +you know one is also this is a paper + + + align:start position:0% +you know one is also this is a paper +about trying to estimate how big product + + align:start position:0% +about trying to estimate how big product + + + align:start position:0% +about trying to estimate how big product +variety CH benefits are and how big + + align:start position:0% +variety CH benefits are and how big + + + align:start position:0% +variety CH benefits are and how big +product variety benefits are in an area + + align:start position:0% +product variety benefits are in an area + + + align:start position:0% +product variety benefits are in an area +where we think the product variety + + align:start position:0% +where we think the product variety + + + align:start position:0% +where we think the product variety +benefits would be bigger um which is in + + align:start position:0% +benefits would be bigger um which is in + + + align:start position:0% +benefits would be bigger um which is in +used books and then the other is also uh + + align:start position:0% +used books and then the other is also uh + + + align:start position:0% +used books and then the other is also uh +you know some sense you can sort of say + + align:start position:0% +you know some sense you can sort of say + + + align:start position:0% +you know some sense you can sort of say +it as a you know uh Chicago School + + align:start position:0% +it as a you know uh Chicago School + + + align:start position:0% +it as a you know uh Chicago School +critique of our search and obfuscation + + align:start position:0% +critique of our search and obfuscation + + + align:start position:0% +critique of our search and obfuscation +paper or in the you know search and obus + + align:start position:0% +paper or in the you know search and obus + + + align:start position:0% +paper or in the you know search and obus +paper we argued that you see these sort + + align:start position:0% +paper we argued that you see these sort + + + align:start position:0% +paper we argued that you see these sort +of not super low and dispersed prices + + align:start position:0% +of not super low and dispersed prices + + + align:start position:0% +of not super low and dispersed prices +for computer components because the + + align:start position:0% +for computer components because the + + + align:start position:0% +for computer components because the +firms have an incentive to uh firms have + + align:start position:0% +firms have an incentive to uh firms have + + + align:start position:0% +firms have an incentive to uh firms have +an incentive to sort of obus gate what + + align:start position:0% +an incentive to sort of obus gate what + + + align:start position:0% +an incentive to sort of obus gate what +they're selling the prices at and invent + + align:start position:0% +they're selling the prices at and invent + + + align:start position:0% +they're selling the prices at and invent +these add-ons or invent complicated + + align:start position:0% +these add-ons or invent complicated + + + align:start position:0% +these add-ons or invent complicated +things that raise search costs and keep + + align:start position:0% +things that raise search costs and keep + + + align:start position:0% +things that raise search costs and keep +prices sort of high and disperse if they + + align:start position:0% +prices sort of high and disperse if they + + + align:start position:0% +prices sort of high and disperse if they +are in a search cost model rather than + + align:start position:0% +are in a search cost model rather than + + + align:start position:0% +are in a search cost model rather than +letting perfect competition come out + + align:start position:0% +letting perfect competition come out + + + align:start position:0% +letting perfect competition come out +here um this paper is sort of going to + + align:start position:0% +here um this paper is sort of going to + + + align:start position:0% +here um this paper is sort of going to +provide an alternate explanation for why + + align:start position:0% +provide an alternate explanation for why + + + align:start position:0% +provide an alternate explanation for why +prices can be high and dispersed it's + + align:start position:0% +prices can be high and dispersed it's + + + align:start position:0% +prices can be high and dispersed it's +going to be that um some sense prices + + align:start position:0% +going to be that um some sense prices + + + align:start position:0% +going to be that um some sense prices +are high in dispersed for two different + + align:start position:0% +are high in dispersed for two different + + + align:start position:0% +are high in dispersed for two different +reasons one is prices are high on the + + align:start position:0% +reasons one is prices are high on the + + + align:start position:0% +reasons one is prices are high on the +internet because the internet is so good + + align:start position:0% +internet because the internet is so good + + + align:start position:0% +internet because the internet is so good +at matching products to people and if + + align:start position:0% +at matching products to people and if + + + align:start position:0% +at matching products to people and if +you think about like you know like a + + align:start position:0% +you think about like you know like a + + + align:start position:0% +you think about like you know like a +used book like used book that you had as + + align:start position:0% +used book like used book that you had as + + + align:start position:0% +used book like used book that you had as +a child um you know and then you have + + align:start position:0% +a child um you know and then you have + + + align:start position:0% +a child um you know and then you have +used book as a child you now have a + + align:start position:0% +used book as a child you now have a + + + align:start position:0% +used book as a child you now have a +niece or nephew you want to buy them the + + align:start position:0% +niece or nephew you want to buy them the + + + align:start position:0% +niece or nephew you want to buy them the +same used book you same picture book + + align:start position:0% +same used book you same picture book + + + align:start position:0% +same used book you same picture book +that you remember from when you were a + + align:start position:0% +that you remember from when you were a + + + align:start position:0% +that you remember from when you were a +kid you're willing to pay many dollars + + align:start position:0% +kid you're willing to pay many dollars + + + align:start position:0% +kid you're willing to pay many dollars +for that book there are a million other + + align:start position:0% +for that book there are a million other + + + align:start position:0% +for that book there are a million other +people out there who didn't remember + + align:start position:0% +people out there who didn't remember + + + align:start position:0% +people out there who didn't remember +that book when they were kids there are + + align:start position:0% +that book when they were kids there are + + + align:start position:0% +that book when they were kids there are +probably hundreds of copies of it + + align:start position:0% +probably hundreds of copies of it + + + align:start position:0% +probably hundreds of copies of it +sitting in physical used book stores + + align:start position:0% +sitting in physical used book stores + + + align:start position:0% +sitting in physical used book stores +with 10 cents marked inside the cover + + align:start position:0% +with 10 cents marked inside the cover + + + align:start position:0% +with 10 cents marked inside the cover +that no one is ever buying if we get + + align:start position:0% +that no one is ever buying if we get + + + align:start position:0% +that no one is ever buying if we get +those books in the hands of the right + + align:start position:0% +those books in the hands of the right + + + align:start position:0% +those books in the hands of the right +people the willingness to pay is way way + + align:start position:0% +people the willingness to pay is way way + + + align:start position:0% +people the willingness to pay is way way +higher in fact actually you know we say + + align:start position:0% +higher in fact actually you know we say + + + align:start position:0% +higher in fact actually you know we say +the paper started when um Sarah was + + align:start position:0% +the paper started when um Sarah was + + + align:start position:0% +the paper started when um Sarah was +writing a paper on Pharmaceuticals and + + align:start position:0% +writing a paper on Pharmaceuticals and + + + align:start position:0% +writing a paper on Pharmaceuticals and +needed some + + align:start position:0% +needed some + + + align:start position:0% +needed some +obscure pharmaceutical book that someone + + align:start position:0% +obscure pharmaceutical book that someone + + + align:start position:0% +obscure pharmaceutical book that someone +had written in the 1970s the MIT + + align:start position:0% +had written in the 1970s the MIT + + + align:start position:0% +had written in the 1970s the MIT +libraries didn't carry uh you know uh + + align:start position:0% +libraries didn't carry uh you know uh + + + align:start position:0% +libraries didn't carry uh you know uh +website selling used books online were + + align:start position:0% +website selling used books online were + + + align:start position:0% +website selling used books online were +new she actually went on to uh website + + align:start position:0% +new she actually went on to uh website + + + align:start position:0% +new she actually went on to uh website +selling used books found the book and + + align:start position:0% +selling used books found the book and + + + align:start position:0% +selling used books found the book and +it's like you know wow I can find this + + align:start position:0% +it's like you know wow I can find this + + + align:start position:0% +it's like you know wow I can find this +book it's I've been trying to find this + + align:start position:0% +book it's I've been trying to find this + + + align:start position:0% +book it's I've been trying to find this +it's only $15 I can pay it out of my + + align:start position:0% +it's only $15 I can pay it out of my + + + align:start position:0% +it's only $15 I can pay it out of my +research account I'm thrilled to get it + + align:start position:0% +research account I'm thrilled to get it + + + align:start position:0% +research account I'm thrilled to get it +for 15 instead of 100 gets it and then + + align:start position:0% +for 15 instead of 100 gets it and then + + + align:start position:0% +for 15 instead of 100 gets it and then +sort of got the book in like 25 cents + + align:start position:0% +sort of got the book in like 25 cents + + + align:start position:0% +sort of got the book in like 25 cents +was penciled inside the front cover of + + align:start position:0% +was penciled inside the front cover of + + + align:start position:0% +was penciled inside the front cover of +it and like she you know it been sitting + + align:start position:0% +it and like she you know it been sitting + + + align:start position:0% +it and like she you know it been sitting +in a bookstore in Iowa City since some + + align:start position:0% +in a bookstore in Iowa City since some + + + align:start position:0% +in a bookstore in Iowa City since some +economics professor retired for the last + + align:start position:0% +economics professor retired for the last + + + align:start position:0% +economics professor retired for the last +decade and no one wanted to pay 25 cents + + align:start position:0% +decade and no one wanted to pay 25 cents + + + align:start position:0% +decade and no one wanted to pay 25 cents +for this and she was thrilled to get it + + align:start position:0% +for this and she was thrilled to get it + + + align:start position:0% +for this and she was thrilled to get it +for 15 bucks and realizing that this is + + align:start position:0% +for 15 bucks and realizing that this is + + + align:start position:0% +for 15 bucks and realizing that this is +sort of potential huge increase in + + align:start position:0% +sort of potential huge increase in + + + align:start position:0% +sort of potential huge increase in +social welfare of match quality + + align:start position:0% +social welfare of match quality + + + align:start position:0% +social welfare of match quality +okay anyway so part of what we're doing + + align:start position:0% +okay anyway so part of what we're doing + + + align:start position:0% +okay anyway so part of what we're doing +is sort + + align:start position:0% +is sort + + + align:start position:0% +is sort +of estimate that match quality and then + + align:start position:0% +of estimate that match quality and then + + + align:start position:0% +of estimate that match quality and then +the second thought on the paper is that + + align:start position:0% +the second thought on the paper is that + + + align:start position:0% +the second thought on the paper is that +you know it's it's nice to sort of + + align:start position:0% +you know it's it's nice to sort of + + + align:start position:0% +you know it's it's nice to sort of +explain two things with one story like + + align:start position:0% +explain two things with one story like + + + align:start position:0% +explain two things with one story like +price are high and dispersed because of + + align:start position:0% +price are high and dispersed because of + + + align:start position:0% +price are high and dispersed because of +search cost but we think there are two + + align:start position:0% +search cost but we think there are two + + + align:start position:0% +search cost but we think there are two +stories here price are high because of + + align:start position:0% +stories here price are high because of + + + align:start position:0% +stories here price are high because of +match quality and prices are dispersed + + align:start position:0% +match quality and prices are dispersed + + + align:start position:0% +match quality and prices are dispersed +because some websites are better at + + align:start position:0% +because some websites are better at + + + align:start position:0% +because some websites are better at +selling things than others and the + + align:start position:0% +selling things than others and the + + + align:start position:0% +selling things than others and the +websites that are better at selling + + align:start position:0% +websites that are better at selling + + + align:start position:0% +websites that are better at selling +things are going be able to command much + + align:start position:0% +things are going be able to command much + + + align:start position:0% +things are going be able to command much +higher prices than the ones that have + + align:start position:0% +higher prices than the ones that have + + + align:start position:0% +higher prices than the ones that have +limited uh attention anyway so the what + + align:start position:0% +limited uh attention anyway so the what + + + align:start position:0% +limited uh attention anyway so the what +what does paper do it's sort of a + + align:start position:0% +what does paper do it's sort of a + + + align:start position:0% +what does paper do it's sort of a +three-part paper first it's sort of + + align:start position:0% +three-part paper first it's sort of + + + align:start position:0% +three-part paper first it's sort of +developing uh simple models to basically + + align:start position:0% +developing uh simple models to basically + + + align:start position:0% +developing uh simple models to basically +illustrate the + + align:start position:0% +illustrate the + + + align:start position:0% +illustrate the +ideas you know one and two are really + + align:start position:0% +ideas you know one and two are really + + + align:start position:0% +ideas you know one and two are really +again just you know me always aspiring + + align:start position:0% +again just you know me always aspiring + + + align:start position:0% +again just you know me always aspiring +to be like Hendrick and Porter and + + align:start position:0% +to be like Hendrick and Porter and + + + align:start position:0% +to be like Hendrick and Porter and +having this Theory having predictions of + + align:start position:0% +having this Theory having predictions of + + + align:start position:0% +having this Theory having predictions of +the theory testing the predictions of + + align:start position:0% +the theory testing the predictions of + + + align:start position:0% +the theory testing the predictions of +theory to convince you that it's right + + align:start position:0% +theory to convince you that it's right + + + align:start position:0% +theory to convince you that it's right +and then the back part of the paper is + + align:start position:0% +and then the back part of the paper is + + + align:start position:0% +and then the back part of the paper is +structural estimates to try to say how + + align:start position:0% +structural estimates to try to say how + + + align:start position:0% +structural estimates to try to say how +big are the welfare gains from product + + align:start position:0% +big are the welfare gains from product + + + align:start position:0% +big are the welfare gains from product +from improved accessibility of usth + + align:start position:0% +from improved accessibility of usth + + + align:start position:0% +from improved accessibility of usth +books sold online versus in physical + + align:start position:0% +books sold online versus in physical + + + align:start position:0% +books sold online versus in physical +stor + + align:start position:0% +stor + + + align:start position:0% +stor +okay + + align:start position:0% +okay + + + align:start position:0% +okay +um so first let me start with the basic + + align:start position:0% +um so first let me start with the basic + + + align:start position:0% +um so first let me start with the basic +Theory and this is a a you know simple + + align:start position:0% +Theory and this is a a you know simple + + + align:start position:0% +Theory and this is a a you know simple +model of dynamic Monopoly pricing of a + + align:start position:0% +model of dynamic Monopoly pricing of a + + + align:start position:0% +model of dynamic Monopoly pricing of a +variety that we don't I guess I never + + align:start position:0% +variety that we don't I guess I never + + + align:start position:0% +variety that we don't I guess I never +covered in the io class um but so + + align:start position:0% +covered in the io class um but so + + + align:start position:0% +covered in the io class um but so +imagine that you have a seller and the + + align:start position:0% +imagine that you have a seller and the + + + align:start position:0% +imagine that you have a seller and the +seller just has one unit to sell there's + + align:start position:0% +seller just has one unit to sell there's + + + align:start position:0% +seller just has one unit to sell there's +no production here so this is a unique + + align:start position:0% +no production here so this is a unique + + + align:start position:0% +no production here so this is a unique +item you're just trying to sell it and + + align:start position:0% +item you're just trying to sell it and + + + align:start position:0% +item you're just trying to sell it and +then you have customers who have values + + align:start position:0% +then you have customers who have values + + + align:start position:0% +then you have customers who have values +VJ drawn from some distribution F and + + align:start position:0% +VJ drawn from some distribution F and + + + align:start position:0% +VJ drawn from some distribution F and +they just arrive at some Plus on rate + + align:start position:0% +they just arrive at some Plus on rate + + + align:start position:0% +they just arrive at some Plus on rate +gamma they walk into your store when + + align:start position:0% +gamma they walk into your store when + + + align:start position:0% +gamma they walk into your store when +they walk into your store and are + + align:start position:0% +they walk into your store and are + + + align:start position:0% +they walk into your store and are +interested in this pharmaceutical + + align:start position:0% +interested in this pharmaceutical + + + align:start position:0% +interested in this pharmaceutical +textbook you have to either sell it to + + align:start position:0% +textbook you have to either sell it to + + + align:start position:0% +textbook you have to either sell it to +them immediately or not at all because + + align:start position:0% +them immediately or not at all because + + + align:start position:0% +them immediately or not at all because +if they you know they walk into your + + align:start position:0% +if they you know they walk into your + + + align:start position:0% +if they you know they walk into your +store they see the book they look at the + + align:start position:0% +store they see the book they look at the + + + align:start position:0% +store they see the book they look at the +price they don't want to buy it they + + align:start position:0% +price they don't want to buy it they + + + align:start position:0% +price they don't want to buy it they +walk out you'll never see them + + align:start position:0% + + + + align:start position:0% + +again how should you set your prices + + align:start position:0% +again how should you set your prices + + + align:start position:0% +again how should you set your prices +well you know the demand from these + + align:start position:0% +well you know the demand from these + + + align:start position:0% +well you know the demand from these +These are onetime consumers who are my + + align:start position:0% +These are onetime consumers who are my + + + align:start position:0% +These are onetime consumers who are my +office so the demand at Price p is just + + align:start position:0% +office so the demand at Price p is just + + + align:start position:0% +office so the demand at Price p is just +1 minus capital F of P the probability + + align:start position:0% +1 minus capital F of P the probability + + + align:start position:0% +1 minus capital F of P the probability +that the consumer's value is above + + align:start position:0% +that the consumer's value is above + + + align:start position:0% +that the consumer's value is above +P so the expected profit is the + + align:start position:0% +P so the expected profit is the + + + align:start position:0% +P so the expected profit is the +expectation at setting a price of p and + + align:start position:0% +expectation at setting a price of p and + + + align:start position:0% +expectation at setting a price of p and +leaving it there is the expectation of p + + align:start position:0% +leaving it there is the expectation of p + + + align:start position:0% +leaving it there is the expectation of p +e to the minus RT where T is the uh + + align:start position:0% +e to the minus RT where T is the uh + + + align:start position:0% +e to the minus RT where T is the uh +random time at which you will sell the + + align:start position:0% +random time at which you will sell the + + + align:start position:0% +random time at which you will sell the +book in this model as long as you set + + align:start position:0% +book in this model as long as you set + + + align:start position:0% +book in this model as long as you set +any P that's less than the upper bound + + align:start position:0% +any P that's less than the upper bound + + + align:start position:0% +any P that's less than the upper bound +of f you'll always sell the book + + align:start position:0% +of f you'll always sell the book + + + align:start position:0% +of f you'll always sell the book +eventually you just may sell it a + + align:start position:0% +eventually you just may sell it a + + + align:start position:0% +eventually you just may sell it a +million years in the future and the Ed + + align:start position:0% +million years in the future and the Ed + + + align:start position:0% +million years in the future and the Ed +RT will eat up all your profits okay so + + align:start position:0% +RT will eat up all your profits okay so + + + align:start position:0% +RT will eat up all your profits okay so +what we're going to do is integrate P + + align:start position:0% +what we're going to do is integrate P + + + align:start position:0% +what we're going to do is integrate P +minus RT times the + + align:start position:0% +minus RT times the + + + align:start position:0% +minus RT times the +density of the probability of selling + + align:start position:0% +density of the probability of selling + + + align:start position:0% +density of the probability of selling +the book at in the interval TT plus + + align:start position:0% +the book at in the interval TT plus + + + align:start position:0% +the book at in the interval TT plus +DT + + align:start position:0% +DT + + + align:start position:0% +DT +um gamma is the Plus on arrival rate + + align:start position:0% +um gamma is the Plus on arrival rate + + + align:start position:0% +um gamma is the Plus on arrival rate +gamma D of p is the Plus on arrival rate + + align:start position:0% +gamma D of p is the Plus on arrival rate + + + align:start position:0% +gamma D of p is the Plus on arrival rate +of people willing to pay at least p and + + align:start position:0% +of people willing to pay at least p and + + + align:start position:0% +of people willing to pay at least p and +so the density of the time you sell it + + align:start position:0% +so the density of the time you sell it + + + align:start position:0% +so the density of the time you sell it +is uh gamma D of p e to minus gamma D of + + align:start position:0% +is uh gamma D of p e to minus gamma D of + + + align:start position:0% +is uh gamma D of p e to minus gamma D of +PT right and you may have seen like if + + align:start position:0% +PT right and you may have seen like if + + + align:start position:0% +PT right and you may have seen like if +you have a Plus on arrival rate gamma + + align:start position:0% +you have a Plus on arrival rate gamma + + + align:start position:0% +you have a Plus on arrival rate gamma +you know the density of arrivals is uh + + align:start position:0% +you know the density of arrivals is uh + + + align:start position:0% +you know the density of arrivals is uh +gamma e minus gamma + + align:start position:0% +gamma e minus gamma + + + align:start position:0% +gamma e minus gamma +T and so the act the arrival rate of + + align:start position:0% +T and so the act the arrival rate of + + + align:start position:0% +T and so the act the arrival rate of +people willing to pay p is this so this + + align:start position:0% +people willing to pay p is this so this + + + align:start position:0% +people willing to pay p is this so this +is the density of the um arrival + + align:start position:0% +is the density of the um arrival + + + align:start position:0% +is the density of the um arrival +distribution and it turns out this is a + + align:start position:0% +distribution and it turns out this is a + + + align:start position:0% +distribution and it turns out this is a +nice well behaved integral and so the uh + + align:start position:0% +nice well behaved integral and so the uh + + + align:start position:0% +nice well behaved integral and so the uh +price is a function of p is this + + align:start position:0% +price is a function of p is this + + + align:start position:0% +price is a function of p is this +expression it's p * gamma D of p over R + + align:start position:0% +expression it's p * gamma D of p over R + + + align:start position:0% +expression it's p * gamma D of p over R +plus gamma D of p and so you know as + + align:start position:0% +plus gamma D of p and so you know as + + + align:start position:0% +plus gamma D of p and so you know as +gamma D of p goes to + + align:start position:0% +gamma D of p goes to + + + align:start position:0% +gamma D of p goes to +one you're selling it almost instantly + + align:start position:0% +one you're selling it almost instantly + + + align:start position:0% +one you're selling it almost instantly +and you and your profit is p uh as gamma + + align:start position:0% +and you and your profit is p uh as gamma + + + align:start position:0% +and you and your profit is p uh as gamma +D of p goes to zero the + + align:start position:0% +D of p goes to zero the + + + align:start position:0% +D of p goes to zero the +r over outweighs the gamma D of p and + + align:start position:0% +r over outweighs the gamma D of p and + + + align:start position:0% +r over outweighs the gamma D of p and +you basically are getting something + + align:start position:0% +you basically are getting something + + + align:start position:0% +you basically are getting something +that's going towards zero U because just + + align:start position:0% +that's going towards zero U because just + + + align:start position:0% +that's going towards zero U because just +this is the discounting and this is the + + align:start position:0% +this is the discounting and this is the + + + align:start position:0% +this is the discounting and this is the +price that would you sell + + align:start position:0% +price that would you sell + + + align:start position:0% +price that would you sell +it and so we you know we can think of + + align:start position:0% +it and so we you know we can think of + + + align:start position:0% +it and so we you know we can think of +Monopoly pricing in two different ways + + align:start position:0% +Monopoly pricing in two different ways + + + align:start position:0% +Monopoly pricing in two different ways +one way to think about it is just the + + align:start position:0% +one way to think about it is just the + + + align:start position:0% +one way to think about it is just the +Monopoly price is the maximizer of this + + align:start position:0% +Monopoly price is the maximizer of this + + + align:start position:0% +Monopoly price is the maximizer of this +expression second way to think about is + + align:start position:0% +expression second way to think about is + + + align:start position:0% +expression second way to think about is +like a dynamic programming + + align:start position:0% +like a dynamic programming + + + align:start position:0% +like a dynamic programming +approach this good doesn't have any + + align:start position:0% +approach this good doesn't have any + + + align:start position:0% +approach this good doesn't have any +production cost but it has an + + align:start position:0% +production cost but it has an + + + align:start position:0% +production cost but it has an +opportunity cost because you can only + + align:start position:0% +opportunity cost because you can only + + + align:start position:0% +opportunity cost because you can only +sell it once and so if Pi + + align:start position:0% +sell it once and so if Pi + + + align:start position:0% +sell it once and so if Pi +star is your equilibrium expected profit + + align:start position:0% +star is your equilibrium expected profit + + + align:start position:0% +star is your equilibrium expected profit +from one unit of this good you're + + align:start position:0% +from one unit of this good you're + + + align:start position:0% +from one unit of this good you're +thinking about someone's in my store now + + align:start position:0% +thinking about someone's in my store now + + + align:start position:0% +thinking about someone's in my store now +what price should I quote + + align:start position:0% +what price should I quote + + + align:start position:0% +what price should I quote +them what I want to do is maximize P + + align:start position:0% +them what I want to do is maximize P + + + align:start position:0% +them what I want to do is maximize P +minus Pi star D of P I just I'm + + align:start position:0% +minus Pi star D of P I just I'm + + + align:start position:0% +minus Pi star D of P I just I'm +maximizing price minus opportunity cost + + align:start position:0% +maximizing price minus opportunity cost + + + align:start position:0% +maximizing price minus opportunity cost +times the demand and so another way to + + align:start position:0% +times the demand and so another way to + + + align:start position:0% +times the demand and so another way to +think about it is that pm has to solve + + align:start position:0% +think about it is that pm has to solve + + + align:start position:0% +think about it is that pm has to solve +this where Pi star is pi of + + align:start position:0% +this where Pi star is pi of + + + align:start position:0% +this where Pi star is pi of +PM okay so it's two different ways to + + align:start position:0% +PM okay so it's two different ways to + + + align:start position:0% +PM okay so it's two different ways to +think about Monopoly pricing for a + + align:start position:0% +think about Monopoly pricing for a + + + align:start position:0% +think about Monopoly pricing for a +unique item when you have customer rals + + align:start position:0% + + + + align:start position:0% + +um uh observations from this Monopoly + + align:start position:0% +um uh observations from this Monopoly + + + align:start position:0% +um uh observations from this Monopoly +pricing model uh Monopoly price is + + align:start position:0% +pricing model uh Monopoly price is + + + align:start position:0% +pricing model uh Monopoly price is +increasing in the customer arrival rate + + align:start position:0% +increasing in the customer arrival rate + + + align:start position:0% +increasing in the customer arrival rate +right why is it increase in customer + + align:start position:0% +right why is it increase in customer + + + align:start position:0% +right why is it increase in customer +arrival rate because the higher is the + + align:start position:0% +arrival rate because the higher is the + + + align:start position:0% +arrival rate because the higher is the +customer arrival rate the higher is your + + align:start position:0% +customer arrival rate the higher is your + + + align:start position:0% +customer arrival rate the higher is your +opportunity cost um this is again a + + align:start position:0% +opportunity cost um this is again a + + + align:start position:0% +opportunity cost um this is again a +14121 exam standard exam question you + + align:start position:0% +14121 exam standard exam question you + + + align:start position:0% +14121 exam standard exam question you +know your Monopoly price is increasing + + align:start position:0% +know your Monopoly price is increasing + + + align:start position:0% +know your Monopoly price is increasing +in your cost um no full stop because of + + align:start position:0% +in your cost um no full stop because of + + + align:start position:0% +in your cost um no full stop because of +this function has increasing differences + + align:start position:0% +this function has increasing differences + + + align:start position:0% +this function has increasing differences +so Monopoly price is increasing + + align:start position:0% +so Monopoly price is increasing + + + align:start position:0% +so Monopoly price is increasing +opportunity cost therefore Monopoly + + align:start position:0% +opportunity cost therefore Monopoly + + + align:start position:0% +opportunity cost therefore Monopoly +price Dynamic Monopoly price increases + + align:start position:0% +price Dynamic Monopoly price increases + + + align:start position:0% +price Dynamic Monopoly price increases +in arrival rate because arrival rate + + align:start position:0% +in arrival rate because arrival rate + + + align:start position:0% +in arrival rate because arrival rate +increases your opportunity set + + align:start position:0% +increases your opportunity set + + + align:start position:0% +increases your opportunity set +opportunity cost goes up um so anyway if + + align:start position:0% +opportunity cost goes up um so anyway if + + + align:start position:0% +opportunity cost goes up um so anyway if +consumers start to arrive at higher + + align:start position:0% +consumers start to arrive at higher + + + align:start position:0% +consumers start to arrive at higher +rates online than they did in physical + + align:start position:0% +rates online than they did in physical + + + align:start position:0% +rates online than they did in physical +stores you're going to get higher prices + + align:start position:0% +stores you're going to get higher prices + + + align:start position:0% +stores you're going to get higher prices +and if there's a rival rate heterog and + + align:start position:0% +and if there's a rival rate heterog and + + + align:start position:0% +and if there's a rival rate heterog and +80 across online stores that's going to + + align:start position:0% +80 across online stores that's going to + + + align:start position:0% +80 across online stores that's going to +lead to price dispersion and stores that + + align:start position:0% +lead to price dispersion and stores that + + + align:start position:0% +lead to price dispersion and stores that +have are frequently visited by online + + align:start position:0% +have are frequently visited by online + + + align:start position:0% +have are frequently visited by online +consumers are going to be able to set + + align:start position:0% +consumers are going to be able to set + + + align:start position:0% +consumers are going to be able to set +higher prices because they're more + + align:start position:0% +higher prices because they're more + + + align:start position:0% +higher prices because they're more +patient those that have fewer visitors + + align:start position:0% +patient those that have fewer visitors + + + align:start position:0% +patient those that have fewer visitors +are going to set lower + + align:start position:0% +are going to set lower + + + align:start position:0% +are going to set lower +prices um how sensitive prices are to + + align:start position:0% +prices um how sensitive prices are to + + + align:start position:0% +prices um how sensitive prices are to +arrival rates depend on the thickness of + + align:start position:0% +arrival rates depend on the thickness of + + + align:start position:0% +arrival rates depend on the thickness of +the upper tail + + align:start position:0% +the upper tail + + + align:start position:0% +the upper tail +um if you have an extremely thick tail + + align:start position:0% +um if you have an extremely thick tail + + + align:start position:0% +um if you have an extremely thick tail +distribution like uh a constant times P + + align:start position:0% +distribution like uh a constant times P + + + align:start position:0% +distribution like uh a constant times P +the minus one then the Monopoly price + + align:start position:0% +the minus one then the Monopoly price + + + align:start position:0% +the minus one then the Monopoly price +increases almost linearly in arrival + + align:start position:0% +increases almost linearly in arrival + + + align:start position:0% +increases almost linearly in arrival +rates uh if you have a very thin tail + + align:start position:0% +rates uh if you have a very thin tail + + + align:start position:0% +rates uh if you have a very thin tail +distribution with a greater than one you + + align:start position:0% +distribution with a greater than one you + + + align:start position:0% +distribution with a greater than one you +know things increase more slowly with + + align:start position:0% +know things increase more slowly with + + + align:start position:0% +know things increase more slowly with +with with arrival rates um and then with + + align:start position:0% +with with arrival rates um and then with + + + align:start position:0% +with with arrival rates um and then with +if demand has this constant elasticity + + align:start position:0% +if demand has this constant elasticity + + + align:start position:0% +if demand has this constant elasticity +form uh like this then you get this very + + align:start position:0% +form uh like this then you get this very + + + align:start position:0% +form uh like this then you get this very +uh unusual theorem so the theorem is you + + align:start position:0% +uh unusual theorem so the theorem is you + + + align:start position:0% +uh unusual theorem so the theorem is you +know supposed the distribution of + + align:start position:0% +know supposed the distribution of + + + align:start position:0% +know supposed the distribution of +consumer valuations is such that demand + + align:start position:0% +consumer valuations is such that demand + + + align:start position:0% +consumer valuations is such that demand +has a truncated constant elasticity form + + align:start position:0% +has a truncated constant elasticity form + + + align:start position:0% +has a truncated constant elasticity form +suppose the Monopoly price is not at the + + align:start position:0% +suppose the Monopoly price is not at the + + + align:start position:0% +suppose the Monopoly price is not at the +Kink of this demand curve at one but + + align:start position:0% +Kink of this demand curve at one but + + + align:start position:0% +Kink of this demand curve at one but +it's on the sort of downward sloping + + align:start position:0% +it's on the sort of downward sloping + + + align:start position:0% +it's on the sort of downward sloping +part uh then the Monopoly price + + align:start position:0% +part uh then the Monopoly price + + + align:start position:0% +part uh then the Monopoly price +maximized is social welfare and social + + align:start position:0% +maximized is social welfare and social + + + align:start position:0% +maximized is social welfare and social +welfare is the price numer just + + align:start position:0% +welfare is the price numer just + + + align:start position:0% +welfare is the price numer just +numerically like I want to say what's + + align:start position:0% +numerically like I want to say what's + + + align:start position:0% +numerically like I want to say what's +the + + align:start position:0% +the + + + align:start position:0% +the +expected producer Surplus plus consumer + + align:start position:0% +expected producer Surplus plus consumer + + + align:start position:0% +expected producer Surplus plus consumer +surplus from selling this book the + + align:start position:0% +surplus from selling this book the + + + align:start position:0% +surplus from selling this book the +answer is if that book is being sold for + + align:start position:0% +answer is if that book is being sold for + + + align:start position:0% +answer is if that book is being sold for +$12 the answer expected welfare is $12 + + align:start position:0% +$12 the answer expected welfare is $12 + + + align:start position:0% +$12 the answer expected welfare is $12 +so in some sense the like it's the most + + align:start position:0% +so in some sense the like it's the most + + + align:start position:0% +so in some sense the like it's the most +powerful structural estimation theorem + + align:start position:0% +powerful structural estimation theorem + + + align:start position:0% +powerful structural estimation theorem +of all time saying if you want to + + align:start position:0% +of all time saying if you want to + + + align:start position:0% +of all time saying if you want to +estimate the social welfare from Dynamic + + align:start position:0% +estimate the social welfare from Dynamic + + + align:start position:0% +estimate the social welfare from Dynamic +sales you just write down the price you + + align:start position:0% +sales you just write down the price you + + + align:start position:0% +sales you just write down the price you +don't need to compute the demand + + align:start position:0% +don't need to compute the demand + + + align:start position:0% +don't need to compute the demand +elasticities you don't need to out + + align:start position:0% +elasticities you don't need to out + + + align:start position:0% +elasticities you don't need to out +consumer surplus nothing you just write + + align:start position:0% +consumer surplus nothing you just write + + + align:start position:0% +consumer surplus nothing you just write +down the price and that is the welfare + + align:start position:0% +down the price and that is the welfare + + + align:start position:0% +down the price and that is the welfare +uh and then there's also this optimality + + align:start position:0% +uh and then there's also this optimality + + + align:start position:0% +uh and then there's also this optimality +theorem that there's no Monopoly + + align:start position:0% +theorem that there's no Monopoly + + + align:start position:0% +theorem that there's no Monopoly +Distortion um and you know so like why + + align:start position:0% +Distortion um and you know so like why + + + align:start position:0% +Distortion um and you know so like why +does this work + + align:start position:0% +does this work + + + align:start position:0% +does this work +out you know obviously the max Monopoly + + align:start position:0% +out you know obviously the max Monopoly + + + align:start position:0% +out you know obviously the max Monopoly +price + + align:start position:0% +price + + + align:start position:0% +price +maximizes uh Monopoly price + + align:start position:0% +maximizes uh Monopoly price + + + align:start position:0% +maximizes uh Monopoly price +maximizes monopolis + + align:start position:0% +maximizes monopolis + + + align:start position:0% +maximizes monopolis +profits um but what is consumer surplus + + align:start position:0% +profits um but what is consumer surplus + + + align:start position:0% +profits um but what is consumer surplus +if so if I have this distribution of + + align:start position:0% +if so if I have this distribution of + + + align:start position:0% +if so if I have this distribution of +consumer valuations + + align:start position:0% + + + + align:start position:0% + +right so I have this distribution of + + align:start position:0% +right so I have this distribution of + + + align:start position:0% +right so I have this distribution of +consumer valuations F of + + align:start position:0% +consumer valuations F of + + + align:start position:0% +consumer valuations F of +V uh and imagine it look something like + + align:start position:0% +V uh and imagine it look something like + + + align:start position:0% +V uh and imagine it look something like +that and suppose I set some price + + align:start position:0% + + + + align:start position:0% + +PM okay um when I sell the good there's + + align:start position:0% +PM okay um when I sell the good there's + + + align:start position:0% +PM okay um when I sell the good there's +some consumer + + align:start position:0% +some consumer + + + align:start position:0% +some consumer +surplus what's the consumer surplus you + + align:start position:0% +surplus what's the consumer surplus you + + + align:start position:0% +surplus what's the consumer surplus you +know it that's the expectation of V + + align:start position:0% +know it that's the expectation of V + + + align:start position:0% +know it that's the expectation of V +minus + + align:start position:0% +minus + + + align:start position:0% +minus +PM conditional on V greater than pm + + align:start position:0% + + + + align:start position:0% + +how does that vary with the Monopoly + + align:start position:0% +how does that vary with the Monopoly + + + align:start position:0% +how does that vary with the Monopoly +price okay like you know in a linear + + align:start position:0% +price okay like you know in a linear + + + align:start position:0% +price okay like you know in a linear +demand + + align:start position:0% +demand + + + align:start position:0% +demand +curve you know in a linear demand curve + + align:start position:0% +curve you know in a linear demand curve + + + align:start position:0% +curve you know in a linear demand curve +as as I set the price really high you + + align:start position:0% +as as I set the price really high you + + + align:start position:0% +as as I set the price really high you +know the expected value conditional + + align:start position:0% +know the expected value conditional + + + align:start position:0% +know the expected value conditional +being bigger than this is almost is + + align:start position:0% +being bigger than this is almost is + + + align:start position:0% +being bigger than this is almost is +almost nothing and so consumer surplus + + align:start position:0% +almost nothing and so consumer surplus + + + align:start position:0% +almost nothing and so consumer surplus +drops substantially with the Monopoly + + align:start position:0% +drops substantially with the Monopoly + + + align:start position:0% +drops substantially with the Monopoly +price uh but in a constant elasticity + + align:start position:0% +price uh but in a constant elasticity + + + align:start position:0% +price uh but in a constant elasticity +model the expected value of V minus pm + + align:start position:0% +model the expected value of V minus pm + + + align:start position:0% +model the expected value of V minus pm +conditional on V being bigger than PM is + + align:start position:0% +conditional on V being bigger than PM is + + + align:start position:0% +conditional on V being bigger than PM is +proportional to to + + align:start position:0% +proportional to to + + + align:start position:0% +proportional to to +PM so in a constant elasticity demand + + align:start position:0% +PM so in a constant elasticity demand + + + align:start position:0% +PM so in a constant elasticity demand +curve consumer surplus is proportional + + align:start position:0% +curve consumer surplus is proportional + + + align:start position:0% +curve consumer surplus is proportional +to the + + align:start position:0% +to the + + + align:start position:0% +to the +price so if you set a really really high + + align:start position:0% +price so if you set a really really high + + + align:start position:0% +price so if you set a really really high +price you don't sell for a very long + + align:start position:0% +price you don't sell for a very long + + + align:start position:0% +price you don't sell for a very long +time and so the P to the minus RT part + + align:start position:0% +time and so the P to the minus RT part + + + align:start position:0% +time and so the P to the minus RT part +gets really small but when you do sell + + align:start position:0% +gets really small but when you do sell + + + align:start position:0% +gets really small but when you do sell +it the person because they willing to + + align:start position:0% +it the person because they willing to + + + align:start position:0% +it the person because they willing to +pay a million dollars for this book + + align:start position:0% +pay a million dollars for this book + + + align:start position:0% +pay a million dollars for this book +their expected Surplus is also on your + + align:start position:0% +their expected Surplus is also on your + + + align:start position:0% +their expected Surplus is also on your +order of a million + + align:start position:0% +order of a million + + + align:start position:0% +order of a million +dollars and so with constant elasticity + + align:start position:0% +dollars and so with constant elasticity + + + align:start position:0% +dollars and so with constant elasticity +demand the consumer surplus is just + + align:start position:0% +demand the consumer surplus is just + + + align:start position:0% +demand the consumer surplus is just +always proportional to the price being + + align:start position:0% +always proportional to the price being + + + align:start position:0% +always proportional to the price being +paid expected proportional to price + + align:start position:0% +paid expected proportional to price + + + align:start position:0% +paid expected proportional to price +therefore by maximizing expected price + + align:start position:0% +therefore by maximizing expected price + + + align:start position:0% +therefore by maximizing expected price +paid discount expected price you're also + + align:start position:0% +paid discount expected price you're also + + + align:start position:0% +paid discount expected price you're also +maximizing discounted expected social + + align:start position:0% +maximizing discounted expected social + + + align:start position:0% +maximizing discounted expected social +welfare um so you know I view this as + + align:start position:0% +welfare um so you know I view this as + + + align:start position:0% +welfare um so you know I view this as +more a I mean it's a it's a neat + + align:start position:0% +more a I mean it's a it's a neat + + + align:start position:0% +more a I mean it's a it's a neat +estimation trick or something but I view + + align:start position:0% +estimation trick or something but I view + + + align:start position:0% +estimation trick or something but I view +it more as a cautionary Tale the + + align:start position:0% +it more as a cautionary Tale the + + + align:start position:0% +it more as a cautionary Tale the +cautionary tale being if in this demand + + align:start position:0% +cautionary tale being if in this demand + + + align:start position:0% +cautionary tale being if in this demand +estimation you can't tell that the + + align:start position:0% +estimation you can't tell that the + + + align:start position:0% +estimation you can't tell that the +demand apart from if you can't tell the + + align:start position:0% +demand apart from if you can't tell the + + + align:start position:0% +demand apart from if you can't tell the +demand curve valuation curve apart from + + align:start position:0% +demand curve valuation curve apart from + + + align:start position:0% +demand curve valuation curve apart from +a constant elasticity demand curve then + + align:start position:0% +a constant elasticity demand curve then + + + align:start position:0% +a constant elasticity demand curve then +you're going to end up finding that the + + align:start position:0% +you're going to end up finding that the + + + align:start position:0% +you're going to end up finding that the +expected welfare is the price regardless + + align:start position:0% +expected welfare is the price regardless + + + align:start position:0% +expected welfare is the price regardless +of what the demand elasticities and + + align:start position:0% +of what the demand elasticities and + + + align:start position:0% +of what the demand elasticities and +everything else + + align:start position:0% +everything else + + + align:start position:0% +everything else +are so it it is you know can be a first + + align:start position:0% +are so it it is you know can be a first + + + align:start position:0% +are so it it is you know can be a first +approximation and it's also if you want + + align:start position:0% +approximation and it's also if you want + + + align:start position:0% +approximation and it's also if you want +a better approximation you need to be + + align:start position:0% +a better approximation you need to be + + + align:start position:0% +a better approximation you need to be +able to tell the shape of this curve + + align:start position:0% +able to tell the shape of this curve + + + align:start position:0% +able to tell the shape of this curve +apart from a constant elasticity one + + align:start position:0% +apart from a constant elasticity one + + + align:start position:0% +apart from a constant elasticity one +which is going to be hard to do in the + + align:start position:0% +which is going to be hard to do in the + + + align:start position:0% +which is going to be hard to do in the +upper tail because you don't see things + + align:start position:0% +upper tail because you don't see things + + + align:start position:0% +upper tail because you don't see things +in the upper tail very + + align:start position:0% + + + + align:start position:0% + +often um okay so now let me think about + + align:start position:0% +often um okay so now let me think about + + + align:start position:0% +often um okay so now let me think about +that's a monopoly model you again think + + align:start position:0% +that's a monopoly model you again think + + + align:start position:0% +that's a monopoly model you again think +about an oligopoly model so you have two + + align:start position:0% +about an oligopoly model so you have two + + + align:start position:0% +about an oligopoly model so you have two +types of consumers you have some people + + align:start position:0% +types of consumers you have some people + + + align:start position:0% +types of consumers you have some people +who just go stra like you know there's + + align:start position:0% +who just go stra like you know there's + + + align:start position:0% +who just go stra like you know there's +some they know some online bookstore + + align:start position:0% +some they know some online bookstore + + + align:start position:0% +some they know some online bookstore +like Better World Books or pows books + + align:start position:0% +like Better World Books or pows books + + + align:start position:0% +like Better World Books or pows books +and they just go directly to Powells + + align:start position:0% +and they just go directly to Powells + + + align:start position:0% +and they just go directly to Powells +books.com uh look for a book there + + align:start position:0% +books.com uh look for a book there + + + align:start position:0% +books.com uh look for a book there +uh we're going to have some consumers + + align:start position:0% +uh we're going to have some consumers + + + align:start position:0% +uh we're going to have some consumers +who sort of have this that or or you do + + align:start position:0% +who sort of have this that or or you do + + + align:start position:0% +who sort of have this that or or you do +a Google search Google search reveals + + align:start position:0% +a Google search Google search reveals + + + align:start position:0% +a Google search Google search reveals +the name of One Bookstore for the title + + align:start position:0% +the name of One Bookstore for the title + + + align:start position:0% +the name of One Bookstore for the title +you want you just go to that bookstore + + align:start position:0% +you want you just go to that bookstore + + + align:start position:0% +you want you just go to that bookstore +and you buy from the first the one + + align:start position:0% +and you buy from the first the one + + + align:start position:0% +and you buy from the first the one +that's highest ranked on Google okay and + + align:start position:0% +that's highest ranked on Google okay and + + + align:start position:0% +that's highest ranked on Google okay and +then we have other people who are going + + align:start position:0% +then we have other people who are going + + + align:start position:0% +then we have other people who are going +to be Shoppers uh who are going to + + align:start position:0% +to be Shoppers uh who are going to + + + align:start position:0% +to be Shoppers uh who are going to +arrive at a passon rate and they observe + + align:start position:0% +arrive at a passon rate and they observe + + + align:start position:0% +arrive at a passon rate and they observe +the prices at all the stores do I have a + + align:start position:0% +the prices at all the stores do I have a + + + align:start position:0% +the prices at all the stores do I have a +picture of a + + align:start position:0% +picture of a + + + align:start position:0% +picture of a +books I don't have a picture of a Books + + align:start position:0% +books I don't have a picture of a Books + + + align:start position:0% +books I don't have a picture of a Books +Okay anyway you know there are + + align:start position:0% +Okay anyway you know there are + + + align:start position:0% +Okay anyway you know there are +um we use data in the p in the uh in the + + align:start position:0% +um we use data in the p in the uh in the + + + align:start position:0% +um we use data in the p in the uh in the +paper from a website called a + + align:start position:0% + + + + align:start position:0% + +books.com um uh a books it was it's just + + align:start position:0% +books.com um uh a books it was it's just + + + align:start position:0% +books.com um uh a books it was it's just +a it's a used book aggregator site you + + align:start position:0% +a it's a used book aggregator site you + + + align:start position:0% +a it's a used book aggregator site you +can go on there you could type in any + + align:start position:0% +can go on there you could type in any + + + align:start position:0% +can go on there you could type in any +book you want that's out of print it + + align:start position:0% +book you want that's out of print it + + + align:start position:0% +book you want that's out of print it +will sort of find 100 online book stores + + align:start position:0% +will sort of find 100 online book stores + + + align:start position:0% +will sort of find 100 online book stores +that sell that particular used book okay + + align:start position:0% +that sell that particular used book okay + + + align:start position:0% +that sell that particular used book okay +um uh actually you know a books used to + + align:start position:0% +um uh actually you know a books used to + + + align:start position:0% +um uh actually you know a books used to +be an independent company it was + + align:start position:0% +be an independent company it was + + + align:start position:0% +be an independent company it was +purchased by Amazon so if you if you go + + align:start position:0% +purchased by Amazon so if you if you go + + + align:start position:0% +purchased by Amazon so if you if you go +to the Amazon bu used button Amazon buy + + align:start position:0% +to the Amazon bu used button Amazon buy + + + align:start position:0% +to the Amazon bu used button Amazon buy +used button is sort of the a books + + align:start position:0% +used button is sort of the a books + + + align:start position:0% +used button is sort of the a books +listings uh some sense Amazon invented + + align:start position:0% +listings uh some sense Amazon invented + + + align:start position:0% +listings uh some sense Amazon invented +the bu used button first when they + + align:start position:0% +the bu used button first when they + + + align:start position:0% +the bu used button first when they +invented the buus button there was + + align:start position:0% +invented the buus button there was + + + align:start position:0% +invented the buus button there was +nothing there under bued you'd click buy + + align:start position:0% +nothing there under bued you'd click buy + + + align:start position:0% +nothing there under bued you'd click buy +used and there were no copies available + + align:start position:0% +used and there were no copies available + + + align:start position:0% +used and there were no copies available +and so they realized well why don't we + + align:start position:0% +and so they realized well why don't we + + + align:start position:0% +and so they realized well why don't we +just buy a books that has 10 million + + align:start position:0% +just buy a books that has 10 million + + + align:start position:0% +just buy a books that has 10 million +Used Books listed and put all their + + align:start position:0% +Used Books listed and put all their + + + align:start position:0% +Used Books listed and put all their +listings under the by used button so now + + align:start position:0% +listings under the by used button so now + + + align:start position:0% +listings under the by used button so now +if you go to the buy used button you're + + align:start position:0% +if you go to the buy used button you're + + + align:start position:0% +if you go to the buy used button you're +seeing the same a books listings okay + + align:start position:0% +seeing the same a books listings okay + + + align:start position:0% +seeing the same a books listings okay +um anyway so our model is that sort of + + align:start position:0% +um anyway so our model is that sort of + + + align:start position:0% +um anyway so our model is that sort of +there these two types of customers the + + align:start position:0% +there these two types of customers the + + + align:start position:0% +there these two types of customers the +one's going to Amazon and clicking buy + + align:start position:0% +one's going to Amazon and clicking buy + + + align:start position:0% +one's going to Amazon and clicking buy +used and getting this curated list of + + align:start position:0% +used and getting this curated list of + + + align:start position:0% +used and getting this curated list of +all the things sorted by price and then + + align:start position:0% +all the things sorted by price and then + + + align:start position:0% +all the things sorted by price and then +the people who are sort of searching for + + align:start position:0% +the people who are sort of searching for + + + align:start position:0% +the people who are sort of searching for +a book by just typing it into Google or + + align:start position:0% +a book by just typing it into Google or + + + align:start position:0% +a book by just typing it into Google or +going directly to a used bookstore that + + align:start position:0% +going directly to a used bookstore that + + + align:start position:0% +going directly to a used bookstore that +they know online and finding it that way + + align:start position:0% +they know online and finding it that way + + + align:start position:0% +they know online and finding it that way +um you know we know that sort of this + + align:start position:0% +um you know we know that sort of this + + + align:start position:0% +um you know we know that sort of this +model can have pure strategy disperse + + align:start position:0% +model can have pure strategy disperse + + + align:start position:0% +model can have pure strategy disperse +price equilibria not so different from + + align:start position:0% +price equilibria not so different from + + + align:start position:0% +price equilibria not so different from +the dispersed price equilibria I did + + align:start position:0% +the dispersed price equilibria I did + + + align:start position:0% +the dispersed price equilibria I did +when I did differentiated product search + + align:start position:0% +when I did differentiated product search + + + align:start position:0% +when I did differentiated product search +models um you know the firms here the + + align:start position:0% +models um you know the firms here the + + + align:start position:0% +models um you know the firms here the +dispersion is going to be the firms that + + align:start position:0% +dispersion is going to be the firms that + + + align:start position:0% +dispersion is going to be the firms that +have the higher arrival rates are going + + align:start position:0% +have the higher arrival rates are going + + + align:start position:0% +have the higher arrival rates are going +to set high prices and mostly serve the + + align:start position:0% +to set high prices and mostly serve the + + + align:start position:0% +to set high prices and mostly serve the +non-shoppers if you don't have a lot of + + align:start position:0% +non-shoppers if you don't have a lot of + + + align:start position:0% +non-shoppers if you don't have a lot of +non-shoppers you're going to set a low + + align:start position:0% +non-shoppers you're going to set a low + + + align:start position:0% +non-shoppers you're going to set a low +price and compete for the + + align:start position:0% +price and compete for the + + + align:start position:0% +price and compete for the +Shoppers okay and when I'm thinking + + align:start position:0% +Shoppers okay and when I'm thinking + + + align:start position:0% +Shoppers okay and when I'm thinking +about like how does the online prices + + align:start position:0% +about like how does the online prices + + + align:start position:0% +about like how does the online prices +differ from the offline prices it helps + + align:start position:0% +differ from the offline prices it helps + + + align:start position:0% +differ from the offline prices it helps +think that there are two reasons one is + + align:start position:0% +think that there are two reasons one is + + + align:start position:0% +think that there are two reasons one is +the match quality reason the higher + + align:start position:0% +the match quality reason the higher + + + align:start position:0% +the match quality reason the higher +rival rates shift the distribution of + + align:start position:0% +rival rates shift the distribution of + + + align:start position:0% +rival rates shift the distribution of +Monopoly prices to the right um the + + align:start position:0% +Monopoly prices to the right um the + + + align:start position:0% +Monopoly prices to the right um the +second is a sort of competition effect + + align:start position:0% +second is a sort of competition effect + + + align:start position:0% +second is a sort of competition effect +which is there's a desire to attack + + align:start position:0% +which is there's a desire to attack + + + align:start position:0% +which is there's a desire to attack +attract the Shoppers so the firms that + + align:start position:0% +attract the Shoppers so the firms that + + + align:start position:0% +attract the Shoppers so the firms that +have low arrival rates of non-shoppers + + align:start position:0% +have low arrival rates of non-shoppers + + + align:start position:0% +have low arrival rates of non-shoppers +are going to sort of be competing + + align:start position:0% +are going to sort of be competing + + + align:start position:0% +are going to sort of be competing +against each other to try to sell in a + + align:start position:0% +against each other to try to sell in a + + + align:start position:0% +against each other to try to sell in a +more betrand likee environment to the + + align:start position:0% +more betrand likee environment to the + + + align:start position:0% +more betrand likee environment to the +people who using the search + + align:start position:0% + + + + align:start position:0% + +engines so I think on the next page I + + align:start position:0% +engines so I think on the next page I + + + align:start position:0% +engines so I think on the next page I +have this illustration so here's a + + align:start position:0% +have this illustration so here's a + + + align:start position:0% +have this illustration so here's a +numerical simulation of the model so the + + align:start position:0% +numerical simulation of the model so the + + + align:start position:0% +numerical simulation of the model so the +this dashed Gray Line would be the + + align:start position:0% +this dashed Gray Line would be the + + + align:start position:0% +this dashed Gray Line would be the +distribution of Monopoly prices if + + align:start position:0% +distribution of Monopoly prices if + + + align:start position:0% +distribution of Monopoly prices if +they're exponentially distributed + + align:start position:0% +they're exponentially distributed + + + align:start position:0% +they're exponentially distributed +arrival rates and so the firms with High + + align:start position:0% +arrival rates and so the firms with High + + + align:start position:0% +arrival rates and so the firms with High +arrival rates at high prices those with + + align:start position:0% +arrival rates at high prices those with + + + align:start position:0% +arrival rates at high prices those with +low arrival rates at low + + align:start position:0% +low arrival rates at low + + + align:start position:0% +low arrival rates at low +prices if I + + align:start position:0% +prices if I + + + align:start position:0% +prices if I +increase uh the value of the good + + align:start position:0% +increase uh the value of the good + + + align:start position:0% +increase uh the value of the good +because people are getting a better + + align:start position:0% +because people are getting a better + + + align:start position:0% +because people are getting a better +matched good the Monopoly price + + align:start position:0% +matched good the Monopoly price + + + align:start position:0% +matched good the Monopoly price +distribution would shift to the right + + align:start position:0% +distribution would shift to the right + + + align:start position:0% +distribution would shift to the right +from the gray line to the Blue + + align:start position:0% +from the gray line to the Blue + + + align:start position:0% +from the gray line to the Blue +Line uh but then if I add in this atom + + align:start position:0% +Line uh but then if I add in this atom + + + align:start position:0% +Line uh but then if I add in this atom +of Shoppers who are just going to buy + + align:start position:0% +of Shoppers who are just going to buy + + + align:start position:0% +of Shoppers who are just going to buy +for the lowest price book and are fairly + + align:start position:0% +for the lowest price book and are fairly + + + align:start position:0% +for the lowest price book and are fairly +price insensitive what you get is the + + align:start position:0% +price insensitive what you get is the + + + align:start position:0% +price insensitive what you get is the +distribution of prices all the firms + + align:start position:0% +distribution of prices all the firms + + + align:start position:0% +distribution of prices all the firms +that are sort of going to be setting the + + align:start position:0% +that are sort of going to be setting the + + + align:start position:0% +that are sort of going to be setting the +lowest prices are now sort of betran + + align:start position:0% +lowest prices are now sort of betran + + + align:start position:0% +lowest prices are now sort of betran +competing against the other firms who + + align:start position:0% +competing against the other firms who + + + align:start position:0% +competing against the other firms who +are also going to set very low prices + + align:start position:0% +are also going to set very low prices + + + align:start position:0% +are also going to set very low prices +and so the low end of the price + + align:start position:0% +and so the low end of the price + + + align:start position:0% +and so the low end of the price +distribution gets pulled down the upper + + align:start position:0% +distribution gets pulled down the upper + + + align:start position:0% +distribution gets pulled down the upper +tail really doesn't get affected at all + + align:start position:0% +tail really doesn't get affected at all + + + align:start position:0% +tail really doesn't get affected at all +the upper tail doesn't get affected at + + align:start position:0% +the upper tail doesn't get affected at + + + align:start position:0% +the upper tail doesn't get affected at +all because these firms were just + + align:start position:0% +all because these firms were just + + + align:start position:0% +all because these firms were just +Monopoly pricing and serving the high + + align:start position:0% +Monopoly pricing and serving the high + + + align:start position:0% +Monopoly pricing and serving the high +value customers who who happen on their + + align:start position:0% +value customers who who happen on their + + + align:start position:0% +value customers who who happen on their +website occasionally they don't bother + + align:start position:0% +website occasionally they don't bother + + + align:start position:0% +website occasionally they don't bother +to compete for the Shoppers they just + + align:start position:0% +to compete for the Shoppers they just + + + align:start position:0% +to compete for the Shoppers they just +leave the high price and just exploit + + align:start position:0% +leave the high price and just exploit + + + align:start position:0% +leave the high price and just exploit +the + + align:start position:0% +the + + + align:start position:0% +the +non-shoppers uh and so what you get is + + align:start position:0% +non-shoppers uh and so what you get is + + + align:start position:0% +non-shoppers uh and so what you get is +this increase in dispersion uh which + + align:start position:0% +this increase in dispersion uh which + + + align:start position:0% +this increase in dispersion uh which +comes from the upper tail really having + + align:start position:0% +comes from the upper tail really having + + + align:start position:0% +comes from the upper tail really having +moved up because people have higher + + align:start position:0% +moved up because people have higher + + + align:start position:0% +moved up because people have higher +values and then the lower tail getting + + align:start position:0% +values and then the lower tail getting + + + align:start position:0% +values and then the lower tail getting +pulled down by the um competition and so + + align:start position:0% +pulled down by the um competition and so + + + align:start position:0% +pulled down by the um competition and so +we think those are the sort of two + + align:start position:0% +we think those are the sort of two + + + align:start position:0% +we think those are the sort of two +things you should expect is that the + + align:start position:0% +things you should expect is that the + + + align:start position:0% +things you should expect is that the +online price distribution has this + + align:start position:0% +online price distribution has this + + + align:start position:0% +online price distribution has this +thicker upper tail relative to the + + align:start position:0% +thicker upper tail relative to the + + + align:start position:0% +thicker upper tail relative to the +offline price distribution but then it + + align:start position:0% +offline price distribution but then it + + + align:start position:0% +offline price distribution but then it +also has a more mass and the lower tail + + align:start position:0% + + + + align:start position:0% + +perhaps um okay so how do we try to test + + align:start position:0% +perhaps um okay so how do we try to test + + + align:start position:0% +perhaps um okay so how do we try to test +this in the data um so we gathered a + + align:start position:0% +this in the data um so we gathered a + + + align:start position:0% +this in the data um so we gathered a +data set that had uh 335 books + + align:start position:0% +data set that had uh 335 books + + + align:start position:0% +data set that had uh 335 books +representative of traditional used + + align:start position:0% +representative of traditional used + + + align:start position:0% +representative of traditional used +bookstores inventories uh the way this + + align:start position:0% +bookstores inventories uh the way this + + + align:start position:0% +bookstores inventories uh the way this +worked is we just um actually Sarah did + + align:start position:0% +worked is we just um actually Sarah did + + + align:start position:0% +worked is we just um actually Sarah did +some of this herself we also just sent + + align:start position:0% +some of this herself we also just sent + + + align:start position:0% +some of this herself we also just sent +an RA to some physical bookstores with + + align:start position:0% +an RA to some physical bookstores with + + + align:start position:0% +an RA to some physical bookstores with +the instructions you know I want you to + + align:start position:0% +the instructions you know I want you to + + + align:start position:0% +the instructions you know I want you to +go to the physical bookstores and just + + align:start position:0% +go to the physical bookstores and just + + + align:start position:0% +go to the physical bookstores and just +go to the first shelf take every 17th + + align:start position:0% +go to the first shelf take every 17th + + + align:start position:0% +go to the first shelf take every 17th +book off the shelf take that book write + + align:start position:0% +book off the shelf take that book write + + + align:start position:0% +book off the shelf take that book write +down the title what it is write down the + + align:start position:0% +down the title what it is write down the + + + align:start position:0% +down the title what it is write down the +price and then just sort of go shelf to + + align:start position:0% +price and then just sort of go shelf to + + + align:start position:0% +price and then just sort of go shelf to +shelf to shelf picking out books um so + + align:start position:0% +shelf to shelf picking out books um so + + + align:start position:0% +shelf to shelf picking out books um so +we have a hundreds what we call Standard + + align:start position:0% +we have a hundreds what we call Standard + + + align:start position:0% +we have a hundreds what we call Standard +books in the data set we also + + align:start position:0% +books in the data set we also + + + align:start position:0% +books in the data set we also +oversampled what we call local interest + + align:start position:0% +oversampled what we call local interest + + + align:start position:0% +oversampled what we call local interest +books like if you go into a Boston + + align:start position:0% +books like if you go into a Boston + + + align:start position:0% +books like if you go into a Boston +bookstore you'll notice there's a shelf + + align:start position:0% +bookstore you'll notice there's a shelf + + + align:start position:0% +bookstore you'll notice there's a shelf +of books about Boston and Boston stuff + + align:start position:0% +of books about Boston and Boston stuff + + + align:start position:0% +of books about Boston and Boston stuff +uh and so what we would said is you know + + align:start position:0% +uh and so what we would said is you know + + + align:start position:0% +uh and so what we would said is you know +if there's a like a local interest + + align:start position:0% +if there's a like a local interest + + + align:start position:0% +if there's a like a local interest +section so there's a Boston shelf in the + + align:start position:0% +section so there's a Boston shelf in the + + + align:start position:0% +section so there's a Boston shelf in the +Boston bookstore one of the bookstores + + align:start position:0% +Boston bookstore one of the bookstores + + + align:start position:0% +Boston bookstore one of the bookstores +was in Atlanta there if there's a book + + align:start position:0% +was in Atlanta there if there's a book + + + align:start position:0% +was in Atlanta there if there's a book +about like Christmas in Georgia you know + + align:start position:0% +about like Christmas in Georgia you know + + + align:start position:0% +about like Christmas in Georgia you know +like find the shelf that has the Georgia + + align:start position:0% +like find the shelf that has the Georgia + + + align:start position:0% +like find the shelf that has the Georgia +books and and oversample those uh and + + align:start position:0% +books and and oversample those uh and + + + align:start position:0% +books and and oversample those uh and +then we also have sort of separate out + + align:start position:0% +then we also have sort of separate out + + + align:start position:0% +then we also have sort of separate out +popular books popular books are the + + align:start position:0% +popular books popular books are the + + + align:start position:0% +popular books popular books are the +things like I mean not not necessarily + + align:start position:0% +things like I mean not not necessarily + + + align:start position:0% +things like I mean not not necessarily +Harry Potter but things that are popular + + align:start position:0% +Harry Potter but things that are popular + + + align:start position:0% +Harry Potter but things that are popular +enough that every used bookstore is + + align:start position:0% +enough that every used bookstore is + + + align:start position:0% +enough that every used bookstore is +probably going to have a copy there are + + align:start position:0% +probably going to have a copy there are + + + align:start position:0% +probably going to have a copy there are +some things that these are former Mega + + align:start position:0% +some things that these are former Mega + + + align:start position:0% +some things that these are former Mega +bestsellers so it's not so rare to find + + align:start position:0% +bestsellers so it's not so rare to find + + + align:start position:0% +bestsellers so it's not so rare to find +these whereas the standard books are all + + align:start position:0% +these whereas the standard books are all + + + align:start position:0% +these whereas the standard books are all +going to be completely nonoverlapping + + align:start position:0% +going to be completely nonoverlapping + + + align:start position:0% +going to be completely nonoverlapping +across stores because just the average + + align:start position:0% +across stores because just the average + + + align:start position:0% +across stores because just the average +used book you know right there are + + align:start position:0% +used book you know right there are + + + align:start position:0% +used book you know right there are +millions of books the average used book + + align:start position:0% +millions of books the average used book + + + align:start position:0% +millions of books the average used book +is just not no one's going to have + + align:start position:0% +is just not no one's going to have + + + align:start position:0% +is just not no one's going to have +another copy of that you could search + + align:start position:0% +another copy of that you could search + + + align:start position:0% +another copy of that you could search +the bookstores all your life and + + align:start position:0% +the bookstores all your life and + + + align:start position:0% +the bookstores all your life and +probably not find another copy of a + + align:start position:0% +probably not find another copy of a + + + align:start position:0% +probably not find another copy of a +standard book okay uh anyway so we have + + align:start position:0% +standard book okay uh anyway so we have + + + align:start position:0% +standard book okay uh anyway so we have +four data collections we have what we + + align:start position:0% +four data collections we have what we + + + align:start position:0% +four data collections we have what we +did is we first just randomly selected + + align:start position:0% +did is we first just randomly selected + + + align:start position:0% +did is we first just randomly selected +these books from physical bookstores and + + align:start position:0% +these books from physical bookstores and + + + align:start position:0% +these books from physical bookstores and +then we went online and searched for + + align:start position:0% +then we went online and searched for + + + align:start position:0% +then we went online and searched for +those books at a + + align:start position:0% +those books at a + + + align:start position:0% +those books at a +books.com and then we noticed that uh in + + align:start position:0% +books.com and then we noticed that uh in + + + align:start position:0% +books.com and then we noticed that uh in +between the time we collected this and + + align:start position:0% +between the time we collected this and + + + align:start position:0% +between the time we collected this and +we and we wrote the paper Amazon bought + + align:start position:0% +we and we wrote the paper Amazon bought + + + align:start position:0% +we and we wrote the paper Amazon bought +uh a books and we thought wow that's a + + align:start position:0% +uh a books and we thought wow that's a + + + align:start position:0% +uh a books and we thought wow that's a +great second accidental uh opportunity + + align:start position:0% +great second accidental uh opportunity + + + align:start position:0% +great second accidental uh opportunity +here is that Amazon buying a books and + + align:start position:0% +here is that Amazon buying a books and + + + align:start position:0% +here is that Amazon buying a books and +putting the listings under by used + + align:start position:0% +putting the listings under by used + + + align:start position:0% +putting the listings under by used +probably just dramatically increased the + + align:start position:0% +probably just dramatically increased the + + + align:start position:0% +probably just dramatically increased the +number of people who are looking at the + + align:start position:0% +number of people who are looking at the + + + align:start position:0% +number of people who are looking at the +sort of curated the search engine + + align:start position:0% +sort of curated the search engine + + + align:start position:0% +sort of curated the search engine +listings for them and so then after + + align:start position:0% +listings for them and so then after + + + align:start position:0% +listings for them and so then after +Amazon bought and Incorporated the a + + align:start position:0% +Amazon bought and Incorporated the a + + + align:start position:0% +Amazon bought and Incorporated the a +books listings we went out and collected + + align:start position:0% +books listings we went out and collected + + + align:start position:0% +books listings we went out and collected +the data again a second time uh and we + + align:start position:0% +the data again a second time uh and we + + + align:start position:0% +the data again a second time uh and we +collected data again a second time so we + + align:start position:0% +collected data again a second time so we + + + align:start position:0% +collected data again a second time so we +would have before and after on prices + + align:start position:0% +would have before and after on prices + + + align:start position:0% +would have before and after on prices +before and after the a books listings uh + + align:start position:0% +before and after the a books listings uh + + + align:start position:0% +before and after the a books listings uh +and then we went and collected the data + + align:start position:0% +and then we went and collected the data + + + align:start position:0% +and then we went and collected the data +a fourth time a few months later we + + align:start position:0% +a fourth time a few months later we + + + align:start position:0% +a fourth time a few months later we +realized it would be useful to have + + align:start position:0% +realized it would be useful to have + + + align:start position:0% +realized it would be useful to have +quantity data and a way to get quantity + + align:start position:0% +quantity data and a way to get quantity + + + align:start position:0% +quantity data and a way to get quantity +data is to search a bookstore for the + + align:start position:0% +data is to search a bookstore for the + + + align:start position:0% +data is to search a bookstore for the +book search that same bookstore two + + align:start position:0% +book search that same bookstore two + + + align:start position:0% +book search that same bookstore two +months later see if they're still + + align:start position:0% +months later see if they're still + + + align:start position:0% +months later see if they're still +listing the book and infer if they don't + + align:start position:0% +listing the book and infer if they don't + + + align:start position:0% +listing the book and infer if they don't +they're not still listing the book two + + align:start position:0% +they're not still listing the book two + + + align:start position:0% +they're not still listing the book two +months later they may have sold the book + + align:start position:0% +months later they may have sold the book + + + align:start position:0% +months later they may have sold the book +now they may have just also just taken + + align:start position:0% +now they may have just also just taken + + + align:start position:0% +now they may have just also just taken +it down but it's it's a pain to take + + align:start position:0% +it down but it's it's a pain to take + + + align:start position:0% +it down but it's it's a pain to take +things down from your website you know + + align:start position:0% +things down from your website you know + + + align:start position:0% +things down from your website you know +you probably take them down when you + + align:start position:0% +you probably take them down when you + + + align:start position:0% +you probably take them down when you +sell them anyway so anyway that's so we + + align:start position:0% +sell them anyway so anyway that's so we + + + align:start position:0% +sell them anyway so anyway that's so we +have these four data Collections and + + align:start position:0% +have these four data Collections and + + + align:start position:0% +have these four data Collections and +last two is how we got quantity + + align:start position:0% +last two is how we got quantity + + + align:start position:0% +last two is how we got quantity +data + + align:start position:0% +data + + + align:start position:0% +data +um okay so what are the sort of + + align:start position:0% +um okay so what are the sort of + + + align:start position:0% +um okay so what are the sort of +predictions we're trying to test + + align:start position:0% +predictions we're trying to test + + + align:start position:0% +predictions we're trying to test +prediction one is that online prices + + align:start position:0% +prediction one is that online prices + + + align:start position:0% +prediction one is that online prices +should be more dispersed in offline + + align:start position:0% +should be more dispersed in offline + + + align:start position:0% +should be more dispersed in offline +prices and have a thicker upper + + align:start position:0% +prices and have a thicker upper + + + align:start position:0% +prices and have a thicker upper +tail um prediction two is local interest + + align:start position:0% +tail um prediction two is local interest + + + align:start position:0% +tail um prediction two is local interest +books may already be M well matched by + + align:start position:0% +books may already be M well matched by + + + align:start position:0% +books may already be M well matched by +the offline stores so the online offline + + align:start position:0% +the offline stores so the online offline + + + align:start position:0% +the offline stores so the online offline +Gap should be small for the local + + align:start position:0% +Gap should be small for the local + + + align:start position:0% +Gap should be small for the local +interest books in particular I put this + + align:start position:0% +interest books in particular I put this + + + align:start position:0% +interest books in particular I put this +uh quote up here you know I found this + + align:start position:0% +uh quote up here you know I found this + + + align:start position:0% +uh quote up here you know I found this +online review of one of the books in our + + align:start position:0% +online review of one of the books in our + + + align:start position:0% +online review of one of the books in our +data set the Mount Vernon Street + + align:start position:0% +data set the Mount Vernon Street + + + align:start position:0% +data set the Mount Vernon Street +Warren's a Boston story I don't know if + + align:start position:0% +Warren's a Boston story I don't know if + + + align:start position:0% +Warren's a Boston story I don't know if +you guys have been to Beacon Hill Mount + + align:start position:0% +you guys have been to Beacon Hill Mount + + + align:start position:0% +you guys have been to Beacon Hill Mount +Vernon is one of the streets on Beacon + + align:start position:0% +Vernon is one of the streets on Beacon + + + align:start position:0% +Vernon is one of the streets on Beacon +Hill uh you know it's a cute Street or + + align:start position:0% +Hill uh you know it's a cute Street or + + + align:start position:0% +Hill uh you know it's a cute Street or +whatever with the gas lamps and the + + align:start position:0% +whatever with the gas lamps and the + + + align:start position:0% +whatever with the gas lamps and the +brick sidewalks and stuff anyway if if + + align:start position:0% +brick sidewalks and stuff anyway if if + + + align:start position:0% +brick sidewalks and stuff anyway if if +you go into a local Boston bookstore you + + align:start position:0% +you go into a local Boston bookstore you + + + align:start position:0% +you go into a local Boston bookstore you +may some one of them some are already + + align:start position:0% +may some one of them some are already + + + align:start position:0% +may some one of them some are already +found a copy of this Mount Vernon Street + + align:start position:0% +found a copy of this Mount Vernon Street + + + align:start position:0% +found a copy of this Mount Vernon Street +Warren anyway if you read that book like + + align:start position:0% +Warren anyway if you read that book like + + + align:start position:0% +Warren anyway if you read that book like +what's your overwhelming thing of so + + align:start position:0% +what's your overwhelming thing of so + + + align:start position:0% +what's your overwhelming thing of so +this is a you know telling the stories + + align:start position:0% +this is a you know telling the stories + + + align:start position:0% +this is a you know telling the stories +of these children who became notable for + + align:start position:0% +of these children who became notable for + + + align:start position:0% +of these children who became notable for +eccentricity and philanthropy green + + align:start position:0% +eccentricity and philanthropy green + + + align:start position:0% +eccentricity and philanthropy green +focuses on Ned Warren homosexual and + + align:start position:0% +focuses on Ned Warren homosexual and + + + align:start position:0% +focuses on Ned Warren homosexual and +mover in the international movement of + + align:start position:0% +mover in the international movement of + + + align:start position:0% +mover in the international movement of +aestheticism who determined to lead a + + align:start position:0% +aestheticism who determined to lead a + + + align:start position:0% +aestheticism who determined to lead a +grand but blighted life the somewhat + + align:start position:0% +grand but blighted life the somewhat + + + align:start position:0% +grand but blighted life the somewhat +jumbled tale of a family thundering + + align:start position:0% +jumbled tale of a family thundering + + + align:start position:0% +jumbled tale of a family thundering +through greed and suicide you know + + align:start position:0% +through greed and suicide you know + + + align:start position:0% +through greed and suicide you know +basically I read this and I'm like I + + align:start position:0% +basically I read this and I'm like I + + + align:start position:0% +basically I read this and I'm like I +don't want to read that book I mean I + + align:start position:0% +don't want to read that book I mean I + + + align:start position:0% +don't want to read that book I mean I +don't I don't know so much about what + + align:start position:0% +don't I don't know so much about what + + + align:start position:0% +don't I don't know so much about what +aestheticism was but how much do I want + + align:start position:0% +aestheticism was but how much do I want + + + align:start position:0% +aestheticism was but how much do I want +to really read about greed and suicide + + align:start position:0% +to really read about greed and suicide + + + align:start position:0% +to really read about greed and suicide +in Boston in 19 C and the whole point is + + align:start position:0% +in Boston in 19 C and the whole point is + + + align:start position:0% +in Boston in 19 C and the whole point is +in fact nobody wants to read that book + + align:start position:0% +in fact nobody wants to read that book + + + align:start position:0% +in fact nobody wants to read that book +book so who's the high value purchaser + + align:start position:0% +book so who's the high value purchaser + + + align:start position:0% +book so who's the high value purchaser +of that book a tourist who's just been + + align:start position:0% +of that book a tourist who's just been + + + align:start position:0% +of that book a tourist who's just been +to Beacon Hill and seen Mount Vernon + + align:start position:0% +to Beacon Hill and seen Mount Vernon + + + align:start position:0% +to Beacon Hill and seen Mount Vernon +Street and finds a copy of a book about + + align:start position:0% +Street and finds a copy of a book about + + + align:start position:0% +Street and finds a copy of a book about +a family on Mount Vernon Street in the + + align:start position:0% +a family on Mount Vernon Street in the + + + align:start position:0% +a family on Mount Vernon Street in the +19th century and thinks oh wow this will + + align:start position:0% +19th century and thinks oh wow this will + + + align:start position:0% +19th century and thinks oh wow this will +be great to read my hotel room and then + + align:start position:0% +be great to read my hotel room and then + + + align:start position:0% +be great to read my hotel room and then +you know you get partway through the + + align:start position:0% +you know you get partway through the + + + align:start position:0% +you know you get partway through the +suicide are and you're like this is not + + align:start position:0% +suicide are and you're like this is not + + + align:start position:0% +suicide are and you're like this is not +my vacation reading and then you sort of + + align:start position:0% +my vacation reading and then you sort of + + + align:start position:0% +my vacation reading and then you sort of +leave it there and then the hotel turns + + align:start position:0% +leave it there and then the hotel turns + + + align:start position:0% +leave it there and then the hotel turns +back in and the sells it to the used + + align:start position:0% +back in and the sells it to the used + + + align:start position:0% +back in and the sells it to the used +bookstore and then they sell it again to + + align:start position:0% +bookstore and then they sell it again to + + + align:start position:0% +bookstore and then they sell it again to +the next tourist or something um uh but + + align:start position:0% +the next tourist or something um uh but + + + align:start position:0% +the next tourist or something um uh but +anyway but so you know for these books + + align:start position:0% +anyway but so you know for these books + + + align:start position:0% +anyway but so you know for these books +like the online prices not much higher + + align:start position:0% +like the online prices not much higher + + + align:start position:0% +like the online prices not much higher +because no one is out there searching + + align:start position:0% +because no one is out there searching + + + align:start position:0% +because no one is out there searching +for that book um but it is a good match + + align:start position:0% +for that book um but it is a good match + + + align:start position:0% +for that book um but it is a good match +to the local physical bookstore um uh + + align:start position:0% +to the local physical bookstore um uh + + + align:start position:0% +to the local physical bookstore um uh +anyway other predictions the online + + align:start position:0% +anyway other predictions the online + + + align:start position:0% +anyway other predictions the online +offline Gap should also be smaller for + + align:start position:0% +offline Gap should also be smaller for + + + align:start position:0% +offline Gap should also be smaller for +popular titles because there's a thinner + + align:start position:0% +popular titles because there's a thinner + + + align:start position:0% +popular titles because there's a thinner +upper tail for popular titles there's + + align:start position:0% +upper tail for popular titles there's + + + align:start position:0% +upper tail for popular titles there's +not the match quality issue and then + + align:start position:0% +not the match quality issue and then + + + align:start position:0% +not the match quality issue and then +Amazon's buy used feature should lead to + + align:start position:0% +Amazon's buy used feature should lead to + + + align:start position:0% +Amazon's buy used feature should lead to +more low prices in 2012 because it + + align:start position:0% +more low prices in 2012 because it + + + align:start position:0% +more low prices in 2012 because it +increases that competition for the lower + + align:start position:0% +increases that competition for the lower + + + align:start position:0% +increases that competition for the lower +tale any so those are the predictions we + + align:start position:0% +tale any so those are the predictions we + + + align:start position:0% +tale any so those are the predictions we +a test and let me sort of just say + + align:start position:0% +a test and let me sort of just say + + + align:start position:0% +a test and let me sort of just say +basically story is almost all of these + + align:start position:0% +basically story is almost all of these + + + align:start position:0% +basically story is almost all of these +things seem to be true in the data in + + align:start position:0% +things seem to be true in the data in + + + align:start position:0% +things seem to be true in the data in +each of these figures the left is the + + align:start position:0% +each of these figures the left is the + + + align:start position:0% +each of these figures the left is the +distribution of offline + + align:start position:0% +distribution of offline + + + align:start position:0% +distribution of offline +prices the right side is an estimate of + + align:start position:0% +prices the right side is an estimate of + + + align:start position:0% +prices the right side is an estimate of +the same object an estimate of the + + align:start position:0% +the same object an estimate of the + + + align:start position:0% +the same object an estimate of the +average across titles of the + + align:start position:0% +average across titles of the + + + align:start position:0% +average across titles of the +distribution of prices for that title um + + align:start position:0% +distribution of prices for that title um + + + align:start position:0% +distribution of prices for that title um +so these should be sort of estimates of + + align:start position:0% +so these should be sort of estimates of + + + align:start position:0% +so these should be sort of estimates of +the same of the estimates of the + + align:start position:0% +the same of the estimates of the + + + align:start position:0% +the same of the estimates of the +distribution of offline prices for these + + align:start position:0% +distribution of offline prices for these + + + align:start position:0% +distribution of offline prices for these +books and the distribution of online + + align:start position:0% +books and the distribution of online + + + align:start position:0% +books and the distribution of online +prices for these books and you see for + + align:start position:0% +prices for these books and you see for + + + align:start position:0% +prices for these books and you see for +the stand standard books there's just + + align:start position:0% +the stand standard books there's just + + + align:start position:0% +the stand standard books there's just +this massively higher upper tale of + + align:start position:0% +this massively higher upper tale of + + + align:start position:0% +this massively higher upper tale of +prices online uh than there was + + align:start position:0% +prices online uh than there was + + + align:start position:0% +prices online uh than there was +offline uh if you go to the local + + align:start position:0% +offline uh if you go to the local + + + align:start position:0% +offline uh if you go to the local +interest books the local interest books + + align:start position:0% +interest books the local interest books + + + align:start position:0% +interest books the local interest books +already had something of a tale um + + align:start position:0% +already had something of a tale um + + + align:start position:0% +already had something of a tale um +online because the ones that are well + + align:start position:0% +online because the ones that are well + + + align:start position:0% +online because the ones that are well +matched that that book that Finds Its + + align:start position:0% +matched that that book that Finds Its + + + align:start position:0% +matched that that book that Finds Its +way to the Beacon Hill bookstore is + + align:start position:0% +way to the Beacon Hill bookstore is + + + align:start position:0% +way to the Beacon Hill bookstore is +already well matched can charge a very + + align:start position:0% +already well matched can charge a very + + + align:start position:0% +already well matched can charge a very +high price offline and so the + + align:start position:0% +high price offline and so the + + + align:start position:0% +high price offline and so the +offline you know more of an upper tale + + align:start position:0% +offline you know more of an upper tale + + + align:start position:0% +offline you know more of an upper tale +offline and online offline Gap is + + align:start position:0% +offline and online offline Gap is + + + align:start position:0% +offline and online offline Gap is +smaller for those local interest books + + align:start position:0% +smaller for those local interest books + + + align:start position:0% +smaller for those local interest books +um popular ones also works but me skip + + align:start position:0% +um popular ones also works but me skip + + + align:start position:0% +um popular ones also works but me skip +that + + align:start position:0% +that + + + align:start position:0% +that +um this is a + + align:start position:0% +um this is a + + + align:start position:0% +um this is a +200922 comparison 2009 2012 + + align:start position:0% +200922 comparison 2009 2012 + + + align:start position:0% +200922 comparison 2009 2012 +comparison um the gray bars are the 2009 + + align:start position:0% +comparison um the gray bars are the 2009 + + + align:start position:0% +comparison um the gray bars are the 2009 +price distribution the white outline + + align:start position:0% +price distribution the white outline + + + align:start position:0% +price distribution the white outline +bars are the + + align:start position:0% +bars are the + + + align:start position:0% +bars are the +2012 distribution and you see these + + align:start position:0% +2012 distribution and you see these + + + align:start position:0% +2012 distribution and you see these +distributions almost lie exactly on top + + align:start position:0% +distributions almost lie exactly on top + + + align:start position:0% +distributions almost lie exactly on top +of each other with the exception that + + align:start position:0% +of each other with the exception that + + + align:start position:0% +of each other with the exception that +like on the standard titles the number + + align:start position:0% +like on the standard titles the number + + + align:start position:0% +like on the standard titles the number +of standard titles sold at a very low + + align:start position:0% +of standard titles sold at a very low + + + align:start position:0% +of standard titles sold at a very low +price just shoots up in 2012 after the + + align:start position:0% +price just shoots up in 2012 after the + + + align:start position:0% +price just shoots up in 2012 after the +Amazon acquisition um and so this is if + + align:start position:0% +Amazon acquisition um and so this is if + + + align:start position:0% +Amazon acquisition um and so this is if +there are many more people searching and + + align:start position:0% +there are many more people searching and + + + align:start position:0% +there are many more people searching and +so that left tail just gets pushed down + + align:start position:0% +so that left tail just gets pushed down + + + align:start position:0% +so that left tail just gets pushed down +but it doesn't affect the upper tail at + + align:start position:0% +but it doesn't affect the upper tail at + + + align:start position:0% +but it doesn't affect the upper tail at +all and you see that in all three + + align:start position:0% +all and you see that in all three + + + align:start position:0% +all and you see that in all three +categories of books that the lower tail + + align:start position:0% +categories of books that the lower tail + + + align:start position:0% +categories of books that the lower tail +gets much thicker and it just seems to + + align:start position:0% +gets much thicker and it just seems to + + + align:start position:0% +gets much thicker and it just seems to +be drawing from these slightly higher + + align:start position:0% +be drawing from these slightly higher + + + align:start position:0% +be drawing from these slightly higher +prices uh as if it's competition is + + align:start position:0% +prices uh as if it's competition is + + + align:start position:0% +prices uh as if it's competition is +pulling down the bottom end + + align:start position:0% +pulling down the bottom end + + + align:start position:0% +pulling down the bottom end +and then uh you know paper also then + + align:start position:0% +and then uh you know paper also then + + + align:start position:0% +and then uh you know paper also then +develops a structural model to sort of + + align:start position:0% +develops a structural model to sort of + + + align:start position:0% +develops a structural model to sort of +estimate what are the welfare gains from + + align:start position:0% +estimate what are the welfare gains from + + + align:start position:0% +estimate what are the welfare gains from +selling books + + align:start position:0% +selling books + + + align:start position:0% +selling books +online and you know our answer is there + + align:start position:0% +online and you know our answer is there + + + align:start position:0% +online and you know our answer is there +seems to be a substantial welfare gain + + align:start position:0% +seems to be a substantial welfare gain + + + align:start position:0% +seems to be a substantial welfare gain +but even in This Used Books case it's + + align:start position:0% +but even in This Used Books case it's + + + align:start position:0% +but even in This Used Books case it's +not enormous so we're more with Quan and + + align:start position:0% +not enormous so we're more with Quan and + + + align:start position:0% +not enormous so we're more with Quan and +Williams than we are with brinol and who + + align:start position:0% +Williams than we are with brinol and who + + + align:start position:0% +Williams than we are with brinol and who +and Smith in terms of what the welfare + + align:start position:0% +and Smith in terms of what the welfare + + + align:start position:0% +and Smith in terms of what the welfare +gains what we find is that the + + align:start position:0% +gains what we find is that the + + + align:start position:0% +gains what we find is that the +estimated uh estimated social welfare + + align:start position:0% +estimated uh estimated social welfare + + + align:start position:0% +estimated uh estimated social welfare +from selling one of these 2009 books in + + align:start position:0% +from selling one of these 2009 books in + + + align:start position:0% +from selling one of these 2009 books in +the offline world was + + align:start position:0% +the offline world was + + + align:start position:0% +the offline world was +$7.7 estimated social welfare from + + align:start position:0% +$7.7 estimated social welfare from + + + align:start position:0% +$7.7 estimated social welfare from +selling it online was + + align:start position:0% +selling it online was + + + align:start position:0% +selling it online was +$16.87 so it's a more than doubling of + + align:start position:0% +$16.87 so it's a more than doubling of + + + align:start position:0% +$16.87 so it's a more than doubling of +welfare that comes from selling online + + align:start position:0% +welfare that comes from selling online + + + align:start position:0% +welfare that comes from selling online +uh but it's only a more than doubling of + + align:start position:0% +uh but it's only a more than doubling of + + + align:start position:0% +uh but it's only a more than doubling of +welfare it's not a massive you know not + + align:start position:0% +welfare it's not a massive you know not + + + align:start position:0% +welfare it's not a massive you know not +a 10 times increase in welfare from + + align:start position:0% +a 10 times increase in welfare from + + + align:start position:0% +a 10 times increase in welfare from +selling these things online and you know + + align:start position:0% +selling these things online and you know + + + align:start position:0% +selling these things online and you know +the if you look at the firm + + align:start position:0% +the if you look at the firm + + + align:start position:0% +the if you look at the firm +profits you know the profit is coming + + align:start position:0% +profits you know the profit is coming + + + align:start position:0% +profits you know the profit is coming +from two different dimensions it's like + + align:start position:0% +from two different dimensions it's like + + + align:start position:0% +from two different dimensions it's like +the average price is going from $12 to + + align:start position:0% +the average price is going from $12 to + + + align:start position:0% +the average price is going from $12 to +$16 when they're sold online and the + + align:start position:0% +$16 when they're sold online and the + + + align:start position:0% +$16 when they're sold online and the +books are being sold sooner so instead + + align:start position:0% +books are being sold sooner so instead + + + align:start position:0% +books are being sold sooner so instead +of the e to the minus RT being3 the e to + + align:start position:0% +of the e to the minus RT being3 the e to + + + align:start position:0% +of the e to the minus RT being3 the e to +the minus RT is 48 um so the books are + + align:start position:0% +the minus RT is 48 um so the books are + + + align:start position:0% +the minus RT is 48 um so the books are +getting sold for higher prices and + + align:start position:0% +getting sold for higher prices and + + + align:start position:0% +getting sold for higher prices and +they're getting sold sooner those two + + align:start position:0% +they're getting sold sooner those two + + + align:start position:0% +they're getting sold sooner those two +things both make profit more than double + + align:start position:0% +things both make profit more than double + + + align:start position:0% +things both make profit more than double +uh we're also estimating that the + + align:start position:0% +uh we're also estimating that the + + + align:start position:0% +uh we're also estimating that the +consumer surplus as best we can is is is + + align:start position:0% +consumer surplus as best we can is is is + + + align:start position:0% +consumer surplus as best we can is is is +also more than doubling and the consumer + + align:start position:0% +also more than doubling and the consumer + + + align:start position:0% +also more than doubling and the consumer +surplus is more than doubling because + + align:start position:0% +surplus is more than doubling because + + + align:start position:0% +surplus is more than doubling because +you know the people who are willing to + + align:start position:0% +you know the people who are willing to + + + align:start position:0% +you know the people who are willing to +buy $16 books get more utility than + + align:start position:0% +buy $16 books get more utility than + + + align:start position:0% +buy $16 books get more utility than +people will to buy $12 books and they're + + align:start position:0% +people will to buy $12 books and they're + + + align:start position:0% +people will to buy $12 books and they're +getting them sooner so the consumer + + align:start position:0% +getting them sooner so the consumer + + + align:start position:0% +getting them sooner so the consumer +surplus is discounted by this instead of + + align:start position:0% + + + + align:start position:0% + +that sorry I'm out of time so anyone you + + align:start position:0% +that sorry I'm out of time so anyone you + + + align:start position:0% +that sorry I'm out of time so anyone you +say uh that's what I've got on retail + + align:start position:0% +say uh that's what I've got on retail + + + align:start position:0% +say uh that's what I've got on retail +for today and then um \ No newline at end of file diff --git a/AwjT1gJSsco.txt b/AwjT1gJSsco.txt new file mode 100644 index 0000000000000000000000000000000000000000..5c125362a81d54acc6da4c834dd4b12f7677ba46 --- /dev/null +++ b/AwjT1gJSsco.txt @@ -0,0 +1,4208 @@ +Walt Guy's biography is on the website. + +I hope you've had a chance to look at it. + +I will just say briefly that I guess, of all +the lecturers coming, that Walt is the only + +one who is still actually working actively +for NASA. + +He is head of the Automation, Robotics and +Simulation Division, division chief at the + +Johnson Space Center. + +But that is not what he's talking about there. + +He's talking about the job that he used to +do for about 20 years which was head of environmental + +thermal life support and crew systems. + +And, of course, the crew system includes all +the space suits and the good stuff that I + +was fortunate enough to get to use. + +So I've got a personal debt of thanks to Walt. + +Aaron, I think you wanted to say a couple +of things so I will pass the microphone to + +you. + +Yes, I would like to say a few words about +Walt. + +We've worked together for many years. + +And Walt Guy has the very unique capability +of being not only an outstanding engineer, + +a technical person, but he also has a very +unique capability of being a great or outstanding + +project manager, program manager. + +No matter what task you gave Walt, he could +deliver the product on performance, on schedule + +and on time. + +He has that unique capability. + +And he's done that from the Apollo Program +through the Shuttle Program. + +And I think you're really in for a treat to +hear Walt talk about the environmental control + +systems. + +He has a lot of information to offer you so, +without further ado, let me turn it over to + +Walt. + +Thank you, Aaron. + +As Aaron said, we worked together over several +programs over a long period of time. + +I was noticing the picture. + +I'm sure that wasn't put there for me. + +But my current responsibilities are the robotic +arm you see there. + +That is a shuttle arm. + +Of course there are station arms also. + +Grapple fixture over here on the left. + +And the little jet pack on the tumbling crewman +there is part of my current responsibilities. + +The 20 years that Jeff mentioned, I was responsible +for the development of the Shuttle spacesuit. + +So it was like it was meant for me anyway. + +What I'd like to do is talk about the design. + +I know in the syllabus it said environmental +control systems. + +So where did all the rest of the stuff come +from? + +If you go back in perspective, the Mercury, +Gemini, Apollo Program had the classical thing + +that aerospace calls environmental control +systems. + +It was basically a cabin system. + +It took care of the living quarters for the +crew. + +But in the Shuttle era the responsibility +of that system expanded to include more than + +just the cabin and, thus, the very long hard +to say name. + +These are the subsystem elements of the environmental +thermal control and life support system. + +The first area I am going to -- These are +the areas, the subsystems. + +The first area is the cabin atmospheric revitalization +system. + +This is a long way of saying to take care +of the atmosphere in the cabin. + +Humans are pollutants and this is the system +that takes care of that. + +The cabin atmospheric pressure and composition, +this is obviously to maintain the pressure + +and enough oxygen for breathing. + +The third is the cabin thermal control, and +that is the classical environmental control + +system. + +But, for Shuttle, we've added some functions. + +One is the water and waste management subsystem. + +There are some hygiene functions required, +there are some recharge of the spacesuit's + +backpack, management of the fuel cell water +system, the fuel cells of the electrical power + +supply and provide a lot of extra water. + +Also, the vehicle at this point, has a dedicated +active thermal control system that takes care + +of all of the systems in the vehicle, not +just the cabin systems. + +And then last is the airlock support subsystem. + +This is the EVA crewman's portal to space. + +And so the environmental thermal control and +life support system covers all these areas. + +What I will do is go through each one of those. + +The first is the cabin atmospheric revitalization +system. + +Its functions are CO2 and trace gas removal, +humidity control, environmental cooling and + +atmospheric circulation and ventilation. + +Again, I will talk each about these. + +But I do want to mention that there is a uniqueness +about space and that there is no convection + +so circulation is important. + +Also, because of the fact that there is no +convection, getting rid of the body heat, + +the latent heat requires a ventilation of +the crew. + +So each of these areas ended up as part of +the system design. + +This is an overview silhouette of the Orbiter. + +I will use this throughout the presentation. + +As you can see, part of the system we're talking +about now, the atmospheric revitalization + +system is located upfront where the crew is. + +It is beneath the floor. + +And we will be talking about the systems in +the remainder of the Orbiter as we go along. + +This is a simplified schematic. + +I would like to start at the cabin fans. + +These are redundant. + +Each fan will do the job. + +The next in line is the CO2 scrubber followed +by the cooler, the cabin heat exchanger. + +There is a bypass around that for control +of the amount of cooling that is needed. + +As you are aware, the Shuttle can fly with +few or many crewmen. + +It turns out, as time has gone on, we fly +pretty much a full compliment. + +But the original design was to fly a small +number of crewmen. + +Also, this does give you temperature control. + +The same heat exchanger provides the condensation +of the water from the atmosphere. + +Therefore, you get humidity control. + +And then that is collected. + +The gas continues on. + +It is now chilled and is provided out to the +flight deck and the middeck to the crew. + +Then the gas from the cabin is then drawn +back in through some flight deck avionics + +and back through the fans. + +So this is the basic systems schematic. + +I might pause here a moment to sort of explain +the role of the government in the development + +of the Shuttle. + +As you know, the prime was Rockwell. + +It was their job to build the vehicle. + +But the government philosophy, management +philosophy was to have ownership of the technical + +aspects of the design. + +So we had basically no excuse. + +If it didn't work it wasn't because the contractor +did something wrong. + +We had to have ownership. + +In fact, Aaron, as the project manager, would +probably look to us first as the reason for + +a problem as opposed to Rockwell because we +were the conscience of the program so we should + +have made sure they didn't do it wrong and +provided whatever technical insight to Aaron + +to make sure he made the programmatic decisions +to make sure things were not done wrong. + +Very early in the Shuttle Program, I was responsible +for an engineering organization. + +And that engineering organization wanted to +own the design of the environmental thermal + +control and life support system. + +We acquired a chamber. + +This is a near atmospheric chamber. + +It is a square so it is obviously not shaped +like the Orbiter cabin, but the volume was + +appropriate. + +And it did allow a sealed environment for +testing. + +It would take a couple of PSI delta Ps. + +That's about all it would take. + +We developed a -- [COMMENT FROM HOFFMAN], +No, that was a different one. + +OK. + +We developed an environmental control system +or an atmospheric revitalization control system + +and placed it inside to do early testing. + +As you can see here, this is the fan package. + +The CO2 scrubbers are here. + +Heat exchange package over here. + +And you can tell we're not current in terms +of calendar-wise. + +The CO2 and trace gas removal, the requirements +were to maintain less than 7.6 millimeters + +of mercury. + +This is certainly to provide a habitable environment +for the crew. + +This is higher than sea level but the medics +agreed that that was a completely adequate + +level for CO2. + +The CO2 absorption came from the humidified +cabin gas so the system had to accommodate + +that as a feed stream. + +The absorbent selected was lithium hydroxide. + +The equation was a lithium hydroxide reacted +with the CO2 to produce lithium carbonate, + +water and heat. + +And this was a single use system. + +It turns out that the lithium hydroxide was +an old solution. + +The previous spacecraft had used the same +solution, but pretty much their solution was + +unique purchased production of lithium hydroxide. + +When we entered the Shuttle era, we were hoping +for a long duration. + +And the idea was to use the commercial products +to get away from special production. + +And so we looked around. + +And the Navy was producing a screened special +production run for their submarines. + +So there was a lot of use there. + +And so the production was reasonably upo. + +We decided to use the Navy grade. + +And so we brought it in and put it in the +test bed that I just showed you and did some + +tests, and it didn't work worth a darn. + +You notice the loops here show that our use +of the canister was much more rapid that we + +had hoped for. + +The nice beautiful deep loops here are a process +that we developed to screen the Navy LiOH + +so that we didn't have to create a new production +capability but were able to test the LiOH + +that came off their production line and get +a LiOH that was much more humidity tolerant. + +The key here turned out to be not the chemical +itself but its ability to produce good performance + +over a wide humidity range. + +So we were able to screen that and make that +a viable non-special production run LiOH. + +The lithium hydroxide, I said, was an old +solution. + +All previous spacecraft have been pretty short +mission. + +And even the Shuttle was a short mission. + +But the specification for Shuttle said that +it should have a capability of going 28 days, + +and 28 days is not a short mission, at least +not in Shuttle parlance. + +The engineering part of the organization said, +well, why don't we go with a regenerative + +system? + +SkyLab had just been successfully flown with +a regenerative system, something that wouldn't + +have all this expendables because 28 days +worth of lithium hydroxide for seven crewmen + +fills everything up with lithium hydroxide. + +There is no room for anything else. + +So we began to look at a regenerative system +that could be used. + +Actually, it was proposed as part of the original +Shuttle development. + +But, at that point, the 28-day mission was +considered a special case and the design case + +was the shorter missions. + +And, in fact, there were even projected to +be a lot of short missions. + +The idea that the Shuttle was a space truck. + +It would take stuff up, dump it out and come +home. + +And so the lithium hydroxide was a lighter +system than a regenerative system. + +The lithium hydroxide was placed into the +vehicle as a basic design. + +But, when the Space Lab era came along, we +needed longer missions. + +We flew about four or five times in this 13 +to 16 day range, and those missions did require + +a lot of lithium hydroxide. + +And so it was proposed to use an absorbent +that was regenerable, and the one that was + +selected was a solid amine. + +The absorbent is a polymerized ethyleneimine. + +Its designation is RNH, and I don't really +know why. + +The absorption actually comes in, in two steps. + +First there is a reaction with water to create +the Freon. + +And then that is then reactive with the CO2 +to give you another free ion, but the CO2 + +is now captured. + +The desorption then with the heat and vacuum +gives you back your original amine. + +So if you pack this in a bed, and what we +used was an expanded metal foam heat exchanger + +that you could fill all the holes with the +solid amine and put the passages adjacent + +to each other so that you could use the heat +of absorption to do your desorption on your + +other side. + +And all you would need to do is expose it +to vacuum. + +It was a very simple system. + +It worked fine for the three or four missions. + +I'm not sure how many missions it was used. + +But it was an adjunct. + +It was added in, put onto the floor, and then +it was taken back out when it was no longer + +needed because it was just wasted load. + +Yes. + +For the lithium hydroxide, the product LiCO3, +is that a solid form or a gas form? + +No, it's a solid lithium carbonate. + +And that goes in the canisters that you remove? + +Right. + +When you remove the canister it's a big lump. + +OK. + +Finishing up the CO2 and trace removal, we +go to the trace removal and use the simple + +system of activated charcoal. + +And, in fact, it is packed into the same canister +that the lithium hydroxide is packed into. + +It is a single use. + +There is a configuration, I believe, now operationally +where the entire canister is activated charcoal + +so it can be used for cabin gas cleanup. + +So, if you had an issue that you needed to +clean the cabin up, you could do that with + +a canister just of charcoal. + +The next area is the environmental cooling +and humidity control. + +I mentioned on the schematic that we have +a cabin heat exchanger. + +The front part of the heat exchanger basically +is your reduced cabin gas temperature. + +The backend of the heat exchanger is where +the condensing occurs because we get the gas + +below the dew point and, therefore, the water +drops out. + +The heat exchanger has the characteristic +that, as the water collects at the outlet + +of the heat exchanger, there were some holes +drilled, actually, in the thin passages so + +the water can be sucked out. + +And it has the nickname "slurper." So it slurps +the water out. + +It takes about 2% of the flow. + +So, as the cabin fan produces the flow through +the heat exchanger, about 2% is siphoned off + +in the slurper. + +And that carries the water to the centripetal +water gas separator. + +This is a device that basically spins the +airstream. + +It's an airstream with water and trained. + +It spins the airstream. + +The water goes to the outside. + +It is collected in a trough and there is a +pitot tube in the trough that the water impinges + +on, and we get about a 40 PSI delta head with +that. + +It's just a pump basically, a pitot pump. + +The atmospheric circulation and ventilation +is the next part of the system. + +As you know, we're still in atmospheric revitalization. + +There are the redundant fans that I mentioned. + +Each fan will do the job. + +There is also flight deck and mid deck duct +system. + +It looks very complicated but there are only +several points I want to make here. + +This is the atmospheric revitalization system +I mentioned before. + +As you see, it is below the floor. + +This is the mid deck here. + +This is the flight deck. + +So it's below the floor of the mid deck. + +The gas exits the heat exchanger. + +It goes up. + +There is some aft mid deck ventilation exhaust. + +It goes on up to the flight deck and exhausts +on the flight deck. + +Also there is a section that goes on the forward +side of the cabin through the forward control + +console and blows in the face of the crew. + +The return is back through some avionic areas +to provide cooling, and then back down to + +the system. + +This is a complicated picture, but really +it is a very simple flow system. + +This becomes important later in our discussion +because good mixing turned out to be a really + +important parameter. + +Not just cooling. + +OK. + +The second. + +Remember we had six? + +This is the second element. + +This is the atmospheric pressure and composition +control. + +The first job is the 14.7. + +The Shuttle selected sea level, the idea being +we could not have a lot of special designed + +equipment. + +Shuttle was intended to be a less expensive +spacecraft than the previous ones. + +And so a sea level atmosphere gave us no questions +about human survival and gave us a lot of + +opportunity for using more standard equipment +and not specially designed equipment. + +There was a requirement, though, for a PSIA +total control, but this was only for an emergency + +de-orbit. + +The problem statement is that you got a hole +in your cabin. + +Don't know how you got it but you have it. + +And the idea is the system has to be able +to sustain the crew for a de-orbit. + +And I don't know who made up the number but +169 minutes is the number. + +We have an emergency return, 169 minutes. + +The system has to be able to accommodate that +keeping the total pressure at or above 8 PSI. + +So there has to be enough flow capability, +enough consumables to do that. + +The half-inch hole was a programmatic decision. + +I cannot speak for where the number exactly +came from, but it probably had to do with + +meteoroid debris kind of analysis that said +what type of hole you could expect. + +Anyway, that was the design for the system. + +The next aspect or element of the system is +the O2/N2 partial pressure control. + +At the total pressure of 14.7, we wanted sea +level which is about 3.2 PSI oxygen. + +At the 8 PSI, we wanted it to be survivable +but the oxygen could be less. + +Obviously, people live in Denver so that works. + +There are also crew breathing masks which +can be used in conjunction with low oxygen + +partial pressure. + +The cabin had to have both positive and negative +relief. + +It had to store the oxygen and nitrogen, and +it had to provide pressurization for the water + +management system. + +Remember earlier I talked about the more pervasive +requirements? + +The water and waste management system now +is placing requirements on the atmospheric + +pressure and composition control. + +This is a silhouette again where basically +here you see the oxygen tank, which is 3300 + +PSI oxygen tank. + +There are nitrogen tanks on both sides. + +These are high pressure tanks all 3300 PSI. + +The relief valves are shown here. + +And there is an O2/N2 supply panel which has +all of the valves and regulators and everything + +on it. + +This system, however, though, gets most of +its oxygen from the cryogenic tanks. + +So that is only just shown as an inlet. + +These tanks are basically part of the power +control system. + +Electrical power is hydrogen and oxygen fuel +cell. + +We use a lot less oxygen than they do so the +storage was integrated. + +And then we use the oxygen for most of the +uses. + +It comes from the main tanks. + +This is a schematic. + +I will start right there. + +This is the cryogenic system. + +This is the main cryogenic system. + +This is not part of the tankage of the pressure +and composition control system. + +It goes through a restrictor. + +This is stored in a super critical state so +the delivery is somewhat limited. + +And so this goes through a restrictor so that +we don't decrease the pressure too fast in + +the cryogenic tank. + +It comes on down through a regulator that +regulates down to 100 PSI. + +And that comes on down to two regulators. + +One is the normal regulator, the 14.7, and +the other is the 8 PSI regulator, both of + +which are available depending on which cabin +mode you're in. + +If you go over this way you will see the nitrogen. + +The nitrogen goes through its own regulator, +and it is regulated at 200 PSI. + +And that's important because that is contrasted +to the 100 here. + +Next the nitrogen goes through an on/off valve, +a solenoid that is connected to partial pressure + +sensors of oxygen. + +And, if you're making up cabin gas, you have +to make a choice as to whether you want nitrogen + +or oxygen. + +And that choice is made by this system and +a simple on/off valve. + +There is no sophisticated control system. + +This is a simple on/off valve. + +If the cabin needs pressure but doesn't need +oxygen then this valve is open and the 200 + +PSI basically backs down the oxygen system. + +There is a check valve here, no oxygen flow +because you get nitrogen. + +At the point that you need oxygen, this valve +closes, then there is no 200 PSI anymore. + +Therefore, the 100 PSI provides oxygen to +the regulators. + +It is a very simple design. + +Off the top of your head, what kind of failures +did you have during qual test that really + +bothered you? + +The regulators were produced by Carlton, and +the regulators were derivatives of regulators + +they had been building for years. + +So the regulator functions really were pretty +good. + +But the early problem we had was the pressure +tolerance wandered and didn't have as good + +a pressure tolerance. + +And they did make some mods to correct that. + +But the more significant issues got into flow +issues. + +Their test capability was pretty limited. + +And when you're talking about very high flow +cases you have to do something with the gas + +to make the regulator think that it is in +an operational environment. + +And so we did a lot of testing, and I will +show you that in just a second, for the high + +flow cases. + +Let's see. + +There is a redundant system. + +It is not shown in this schematic but there +are two of these, just like this. + +This is the pressurization for the water and +waste management system you see here. + +I would say there is a crossover to the redundant +system so that you can do mix and match. + +If you have a problem in both systems, you +can mix and match the capabilities. + +Also, the oxygen system provides the emergency +breathing system. + +It also provides oxygen to the air lock for +recharge of the backpack. + +We will talk about that later. + +And I believe that's it. + +So, for normal pressure, we have 14.7. + +And you have the automatic pressure regulator, +basically on/off valve and the regulator. + +The partial pressure is controlled by the +3.2 PSI which is the solenoid that controls + +that. + +It is a very simple system. + +The oxygen partial pressure does have another +set point at the PSIA goes down to 2.45 PSI. + +And I will show you that in a minute. + +For cabin pressure relief, the problem statement +really is why do you need relief? + +Well, what if one of those lines breaks? + +You've got 3300 PSI tankage. + +It is all plumed together. + +The crew, God forbid, step on a line and break +it, and now you've got all this nitrogen rushing + +in. + +You don't want the cabin to explode, right? + +So you need a relief valve. + +And the relief valve was set at 16.2. + +And, again, that is one of the high flow cases +that we ended up testing. + +The system was designed with three relief +valves. + +Any tool will do the job. + +That is just a redundancy philosophy. + +Sometimes you will see two items where either +one does the job. + +In this case, this is a very critical issue +so there is a double redundancy here. + +For the negative pressure protection, there +is an 8 PSI delta relief valve. + +In fact, there are three of those. + +You don't need the two to operate, but there +are three. + +This is for the return that I just showed +you. + +If you come back with a hole in the cabin, +the cabin is at 8 PSI, you cannot reverse + +flow through that hole. + +That is not going to work. + +You don't want the cabin imploding on the +crew so you've got to make up, as you come + +in the lower altitude, obviously the higher +pressure, you've got to get that gas back + +in the cabin. + +So that's what that is for. + +OK. + +This is the other pressure vessel that was +used as a test site. + +This was called the Environmental Test Article. + +Rockwell gave it that name. + +What they planned to do with this device, +when they built it, was to do all the wiring + +runs and the plumbing runs in there. + +It was going to be a mockup. + +It turned out they built a rather beefy tank. + +In fact, maybe they got one very inexpensively. + +I'm not sure how they ended up with it, but +they got it. + +They did do all the secondary structure, so +it had the right shape inside. + +And so it turned out they didn't end up using +it. + +They went onto other methods. + +And so it ended up leftover in the program. + +We convinced Aaron that he ought to give it +to us, and he did. + +This is what it looks like in cutaway. + +You see here all the secondary structure, +it was in boxes but we put it all in. + +Foamed it in so that the volume was right, +so the cabin volume was essentially perfect. + +It had the flight deck. + +It had the mid deck. + +It had the lower deck for the environmental +control system. + +But we also asked Aaron to give us the cert +hardware, which he did. + +So we had the cert hardware underneath the +floor. + +And the pressure control system we're talking +about, actually, is on this back wall. + +That is a picture of it. + +What we did is faithfully run the lines. + +In fact, we even use the same line material, +same fittings, same everything. + +So we faithfully duplicated inside this test +article the volume and the geometry and the + +system. + +All the ventilation ducts you saw, all those +were in place. + +We will come back to it later, but you'll +notice on the back wall of this test facility + +there is an airlock hatch. + +And later on I will tell you where that goes. + +But this is the control panel and the nitrogen/oxygen +system. + +This is test data. + +We did some testing to see how the system +worked. + +This was testing of basically the on/off oxygen +control system. + +Let me see if I can walk through this simply. + +We're working total pressure here, oxygen +partial pressure here. + +During this first interval the oxygen is on. + +What we're doing here is we're breathing it +down. + +And, when we hit the lower limit so that the +regulator wants to do something, then the + +oxygen partial pressure starts up because +the regulator comes on. + +Now, the total pressure is maintained because +that is what the regulator is supposed to + +do, maintain total pressure. + +But as it maintains the total pressure it +is doing it with oxygen and, therefore, the + +partial pressure is going up. + +When it is satisfied, that is enough partial +pressure of oxygen, then the solenoid valve + +opens and you see the nitrogen come on. + +Now, you remember the nitrogen feed was at +300 PSI versus 200 PSI. + +So there is a little jump. + +That is just a mechanical artifact of the +regulator. + +If you change the inlet pressure it regulates +slightly differently because it is a balance + +system. + +You see a little jump there. + +And then, during this period, the pressure +is maintained. + +But we're breathing off the oxygen because +we've got the oxygen fenced off now. + +And then when the pressure is satisfied and +the solenoid goes back the other way then + +we again start the oxygen again. + +So the system worked quite well. + +If you notice the tolerance band spec-wise +was pretty wide, the system operated on a + +very narrow brand so we were very pleased +with that. + +Normally that is important. + +Not only because it shows you that you do +have a good sensitive system, but you cannot + +-- Mechanical hardware, electrical hardware, +either one never operates down the middle + +always. + +There is drift. + +You need a little tolerance in your band here +to have a decent system design. + +Yes. + +Does this change a lot when you have the crew +performing high metabolic activity? + +The cabin is so large that it really doesn't +know. + +The cycles would be different, obviously, +because you consume more oxygen, you would + +need more oxygen. + +So the on/off cycle would favor longer oxygen +cycles. + +But, in the big picture, there is really not +a lot of change. + +What was this time period? + +It looks like this was about three hours maybe. + +That might go to two hours for a cycle. + +I mean not really very much. + +Sorry. + +Does microgravity have much effect on circulation? + +There is no circulation in microgravity. + +It just lays there. + +You push it or it doesn't go. + +Diffusion is a driving force, so if you're +really, really patient, even at zero G you + +can wait, but you cannot stay alive that way. + +But, yes, you do have to have ventilation. + +Still in the atmospheric pressure and composition +control. + +This is the emergency breathing equipment. + +We used plug-in face masks. + +There are some uses for the mask that require +a carry on bottle to give portability, but + +the vehicle does have plug-in capability. + +The masks were purge-type masks. + +You're probably not familiar much with masks, +but there is a mask called a rebreather which + +basically your lung power does all the work +and you only purge enough to keep the CO2 + +down and you keep rebreathing. + +And then the purge-type is every breath is +a fresh breath, and you then exhale and the + +gas goes out in the cabin. + +And that's the type that this is because the +cabin needs the oxygen. + +I mean it's not going anywhere bad. + +It is OK that it's not completely spent. + +It's good. + +That's like a scuba mask, right? + +I don't scuba. + +Sorry. + +But I think the answer is yes. + +With scuba, you take in the air and then you +blow it all out. + +I mean there are scuba rebreathing systems, +but the typical scuba gear is not. + +Rather than raising your hand, if you make +a noise of some kind. + +Sorry. + +I don't mean to ignore you. + +The mask can be used in a contaminated environment +and the mask can be used if the concentration + +of O2 is low to give you a better oxygen level. + +This is the PSIA test that we did. + +Actually, a series of tests. + +But this is data from one. + +As you see, we started up in the 14.7 range. + +We simulated the hole. + +The pressure immediately starts down. + +The partial pressure of oxygen we let degrade +to about the 2.2 range. + +This is a different set point. + +Remember I told you on the oxygen sensors +we have two set points? + +This is the second set point. + +And so we have the lower oxygen partial pressure. + +The system came down. + +The PSIA regulator, which is always online, +captured the pressure decay, caught it, and + +the solenoid valve popped back and forth to +keep the oxygen OK because we're losing now. + +We're going out this half-inch hole. + +And the system worked just fine. + +This did have the crew on the masks because +that is livable, you can live there, but the + +mask is a better environment. + +This is a mask case. + +This was a requirement that came on later. + +The design is the design now. + +The vehicle exists so we have to now operate +the vehicle with accommodations for operationally + +what we want to do with it. + +And a new requirement developed and was imposed +on the vehicle. + +And that requirement had to do with the space +suit for the EVA operation. + +The Shuttle spacesuits are basically 100% +O2. + +And the classical way of going EVA from a +sea level environment was a four hour prebreathe. + +Actually, as much as six hours depending on +how conservative the medics were at the time, + +that number varied around some, to prevent +bends. + +But it was determined that if you accommodized +at 9 PSI for about 12 hours then you only + +required a really short prebreathe. + +And the suit-up time, which gave you 30 to +40 minutes, actually gave you sort of a free + +tune-up to your prebreathe as part of your +suit-up operation. + +And so that was viewed as a much better way +to do EVAs than the previous way. + +The masks are useful but are not very comfortable. + +So, if you have to keep them on for a long +period of time, they're not very comfortable + +at all. + +Also the medics were very concerned about +mask leakage, that if there was any nitrogen + +inflow that that could break the prebreathe. + +But our system isn't designed for 9. + +We have a 14.7 and an eight, but we don't +have a 9, so we needed a manual procedure. + +But before that could be accepted there were +some issues that had to be evaluated. + +And we had to do testing on each of these +issues. + +The first is the flow rate acceptability at +9 PSI. + +Obviously, the less dense gas you're not going +to get the same mask flow rate. + +And we had to make sure that that ventilation +was going to be adequate. + +And testing proved that it was. + +The next is a thermal acceptability. + +There are really two aspects to this. + +One is the fan itself is cooled by the environment, +so if the environment doesn't provide as much + +cooling to fan itself it could overheat. + +Also, the electronic equipment, some of which +is air cooled, the less dense gas could be + +a problem there. + +It turned out that could be controlled with +load control. + +That could off load power and make that acceptable. + +The CO2 performance at 9 PSI, we needed to +make sure that was OK. + +It turned out that, of course, the 9 PSI case, +we don't care about the lithium hydroxide. + +The purge flow is so great there is no CO2 +problem. + +But at 9 PSI for 12 hours you have to get +performance out of the lithium hydroxide. + +So we checked that and that worked out fine. + +And the last item was the ventilation adequacy. + +We do have a press and depress. + +You've got to come down to 9 and you've got +to go back. + +And both of those adjust the gas mixture. + +And so we wanted to prove that that was OK. + +And so we went to the facility that we were +talking about and ran this profile. + +Now, this profile was created by our-- yes? + +[AUDIENCE QUESTION] + +Well, that's what I just said. + +Yes, it does. + +The air-cooled equipment is going to run hot. + +If you want to cool that equipment, it will +become a little clearer later, but the equipment + +is in equipment bays. + +And so, with the less dense gas, you need +to have some of that equipment turned off + +so that the cooling that is available is adequate. + +So you do load control, get rid of some of +the electronics. + +And, therefore, the air that's left, the atmosphere +that is left can cool the equipment. + +And then when do you increase the pressure +back to normal after the EVA? + +After the 12 hours. + +No, actually it's before the EVA. + +Well, I'm not sure what they do now. + +When you're all finished with your EVAs then +you bring the cabin back. + +Because, typically, you do multiple EVAs. + +And so, from one day to the next, you just +keep the cabin at, actually, we use 10.2 now + +rather than 9, but I think you have to certify +it for 9, right? + +This was an early certification for 9. + +Yes. + +But wouldn't it have been easier to simply +design the whole system for 9 from the beginning + +if you had [OVERLAPPING VOICES]? + +Well, this was not a Shuttle requirement. + +This was an operational requirement that occurred +after the Shuttle specifications were set. + +You're correct. + +If we knew it ahead of time it would have +been much easier to do it all for 9 PSIs, + +exactly. + +It would have just been a third condition. + +But, as Jeff pointed out, we changed our mind. + +The first was 9 and now we're at 10.2, so +we're not consistent. + +As we learn, we change our mind. + +And the 10.2 was selected later. + +Our mission operations people that do the +crew time lining and all, they created this + +procedure. + +And so we tested it. + +This has a simple depress cycle. + +You come from 14.7. + +You hesitate at about 11 and replenish the +oxygen. + +You do that twice. + +You then do manual control down at the 9 psi +level. + +You notice the oxygen partial pressure here +is always maintained by these adjustments, + +and also during the manual period you select +what you want. + +And then when you come back, the procedure +was to increase the nitrogen and then finish + +the top off with oxygen. + +That was thought to be completely acceptable +because the oxygen level, at this point, is + +completely viable. + +And so doing the nitrogen first and topping +it off with oxygen was thought to be an acceptable + +way to operate. + +So we did the test and this is what happened. + +We were all nice and comfortable with our +oxygen partial pressure. + +And you see the area next to where we were +repressing. + +We depleted the oxygen substantially. + +And the mid deck and even the flight deck, +we depleted the oxygen. + +And I've only shown you half the data. + +If you look at the rest of the data, you see +where the oxygen went. + +These equipment bays that I mentioned earlier, +the avionics bays and other equipment bays + +are basically isolated volumes from the cabin. + +So, as the pressure comes up, what you're +doing is you're pressurizing these areas with + +cabin gas, which is oxygen and nitrogen, you're +pressurizing these areas with nitrogen only. + +Basically, you are depleting the partial pressure +here. + +You're increasing the partial pressure here. + +You remember partial pressure. + +You just count the molecules. + +That's all you have to do. + +Basically, we're putting more oxygen molecules +here and we're taking them out of these areas. + +And, therefore, they are going down. + +This is just a picture of one of the bays. + +You see all the empty space around the equipment. + +That is where the gas is. + +We came up with an alternate procedure which +is to simultaneously put the oxygen and nitrogen + +in together. + +And, of course, there is the 9 back to 14.7. + +And you notice that solved the problem. + +There is still some dip at the supply area +because the mixture is lean. + +We need from 9 to 14.7, 5.7 PSI total pressure +increase. + +But we only need 2.5 up to 3.2 oxygen. + +This is a mixture, but it's a lean mixture. + +So there is still some slight loss, but the +only area that came under an issue is near + +the inlet where the O2/N2 supply panel is. + +And, of course, you can just avoid that area. + +Well, I should say that that area happens +to be right around the bathroom. + +And so, before we repressurized the Shuttle, +the commander would say anybody who has to + +use the bathroom use it now because for about +ten, fifteen minutes, while we're depressurizing, + +it's off limits. + +OK. + +Next item. + +This is the water and waste management area. + +This is one of the six items. + +We have potable and waste water inventory +management. + +We're continually producing potable water, +as you know, and waste water. + +We have to dump them, we have to use them, +so that is part of the requirement of this + +system. + +We have to store water for drinking, food +prep and waste water storage. + +It has to be dumped to space. + +Commode and urinal for human waste collection. + +And we provide water for an evaporative heat +sink, which we will talk about later, called + +the flash evaporator. + +Yes. + +This is an outstanding example of systems +engineers, this total system that Walt is + +talking about. + +We can really see the interaction between +all the systems and the spacecraft. + +This really is a systems engineering problem. + +Potable water, we take all the fuel cell byproduct +water and use it. + +So it is basically in a fluent to the power +system. + +We do have a launch storage capability for +water and we do provide sterilization. + +The sterilization is iodine. + +We started out designing a silver ion system. + +It turned out that we had manufacturing problems +and the company ended up going out of business, + +so we reverted to iodine. + +The Lunar Module used iodine. + +Waste water, the condensate from the cabin +humidity control and urine and the urine pretreat. + +Urine has to be pretreated to bind the urea. + +If you don't, you get a lot of ammonia. + +It uses a chemical called Oxzone. + +It's an acid. + +I'm not really sure what it is. + +This is where the system is located. + +This is one of the simpler schematics. + +The water tanks are here. + +The water comes from the fuel cell. + +As I said, by the way, the delivery is about +150 degrees and 60 psi. + +So there is a lot of hydrogen dissolved in +the water. + +The water is collected in the fuel cells on +the hydrogen side, so there is a lot of hydrogen. + +There is a hydrogen separator here. + +Otherwise, your tanks would end up full of +hydrogen which is what you don't want. + +You will get water in the tanks. + +The hydrogen separator is a silver palladium +metal. + +It is catalyzed. + +It is basically porous to hydrogen but not +to water. + +If you expose the backside to the vacuum it +pulls the hydrogen off and the water goes + +through just fine. + +I will say that there still is a rather high +gas content in the water that you drink. + +And that gas, of course, evolves once it gets +inside your stomach with predictable results. + +[LAUGHTER] + +Yes. + +In fact, all sorts of systems that Jeff could +explain. + +They have slinger systems and all sorts of +systems to get separation because it is not + +really possible to get all the gas out of +the water. + +OK. + +There is a dump system. + +There is a potable waste dump to vacuum. + +There is also a vacuum vent, which I will +show you what that is all about. + +And then the flash evaporator that I mentioned, +and I will mention more later, is in the back + +of the vehicle and it has a redundant water +feed system both sides. + +This is a schematic. + +Start at the same place. + +Water from the fuel cells goes through the +hydrogen separator and then into this bank + +of tanks. + +The tanks are pressurized. + +They are yellow bellows tanks. + +On the back side of the bellows is nitrogen. + +On the forward side, of course, is the potable +water. + +There is a hydrophobic filter on the downside +of each tank. + +If a bellows were to leak, you don't want +water into your nitrogen system. + +So this is a filter to prevent that. + +I mentioned the twin flash evaporator feeds. + +There they are. + +This is the dump nozzle here. + +The potable water system provides water to +the crew so there is a regular water interface + +and a chilled water interface here. + +I believe that is it. + +I remember there were more problems with Apollo +than there were with Shuttle. + +49:30 I don't have those sorted mentally. + +I'm sorry. + +I don't remember. + +I'm not sure. + +[AUDIENCE QUESTION] + +Maybe that was on Apollo. + +[AUDIENCE QUESTION] + +Basically that means you put your water into +a plastic bag. + +And now you can actually swing it around like +so. + +And so the water will go to the outside and +the gas is in the inside. + +So that actually separates them and you can +squeeze the gas out through a valve. + +On-orbit trash storage, there is an overboard +bleed for odor control. + +It's a very small overboard bleed to vacuum. + +And the human solid waste collection and storage +is also vacuum dried and stabilized. + +This is a waste management picture. + +The subject we were just talking about is +the vacuum vent. + +That vacuum vent does vent the commode area +where the feces are. + +That vent also provides a vent for the water +separator. + +It also provides a vent for airlock depress +for EVA. + +So this is the vacuum system. + +The urine is collected and trained in a liquid. + +Well, let me say that different. + +The urine, after it has been separated from +the gas stream, is stored in a waste tank, + +as is the humidity from the cabin atmospheric +revitalization system. + +And then that is pressurized from the pressured +composition control system and is dumped overboard. + +This waster is not used for anything. + +It is basically dumped just to do inventory +management. + +The next picture explains a little better +about the commode and the urinals themselves. + +The urinal originally had a unisex interface +cup. + +It turned out that didn't work very well, +and so later flights there was a custom male/female. + +And later there were even some more customizing +for the crew, I believe, but I don't have + +the details on that. + +The urinal itself, obviously for urination, +there needs to be some way to make the urine + +go where you want it to go. + +And those were done in fan separators. + +So there is gas pulled in the cup. + +And in training the urine, the urine then +comes down and goes through the separators. + +This is also a centrifugal-type separator. + +And then that is sent to the head that is +created here. + +Then puts that waste water urine in the waste +system. + +The EMU spacesuit, it also has a condensate +drain after each EVA, and it also goes through + +this same system and into the waste tank. + +The commode. + +Basically there is a seat. + +The seat has a small opening. + +The commode itself is basically a cylinder +or a tub. + +And there is a slinger in the bottom. + +So the slinger basically distributes the paper +and the fecal matter on the outside wall in + +a thin layer. + +The vacuum then can dry that so that it deactivates +it so it does not end up either any odor or + +creating any kind of bacteriological issues. + +But the entrainment of the fecal material +so that it, in fact, hits the slinger, is + +done with an air flow. + +The air flow comes in around the seat itself. + +That requires good contact with the seat. + +It also requires positioning. + +Positioning turned out to be an early issue, +or reliable positioning, and so a trainer + +was put together that had a camera here. + +And the trainer, I might add, was discretely +located in a non-observable place so that + +it could be used in privacy, the comings and +goings, and also the use of the facility itself. + +And they told us it was not hooked up to a +tape recorder. + +[LAUGHTER] + +Just to elaborate on that. + +Basically, the problem is it really is a rather +small opening. + +And it just doesn't feel natural to know where +to put yourself down. + +And it actually did lead to significant messes +on orbit. + +I won't go into any more detail. + +But the idea is that you would position yourself +the way you thought it should be, and then + +you would turn on the lights. + +And there is a TV screen in front of you. + +I'm not making this up. + +[LAUGHTER] + +So that you could see how close you are to +the bull's-eye. + +Enough said. + +The cabin thermal control is another one of +the subsystem elements. + +It is a circulating liquid cooling system. + +It provides the heat sink for the atmosphere +itself. + +It also provides the ability to reject that +heat to the spacecraft cooling system because + +you've got to get rid of it out of the cabin. + +It has some avionics cold plates, some air +cool avionics, support the crew in the airlock + +and a portable water chiller. + +This is the location. + +You will notice the avionics bays are listed +here with their little circulation systems. + +The liquid system then services each of those, +the chill or the condensing heat exchanger. + +And this is the place that the cabin system +connects to the spacecraft system, on the + +aft bulkhead right here. + +We will see the other half of this system +in a little bit. + +This is a schematic that is very complicated +looking but it is fairly simple. + +Let me show you the air piece first. + +Look at the black lines. + +Those are twin fans. + +It goes through the air-cooled avionics through +the heat exchanger to get rid of the heat. + +There are some cold plated avionics in each +bay, so you take care of the cold plated and + +the air-cooled in this bay and in this bay +and in this bay. + +Now you've got all of the electronics taken +care of. + +I should have started this up at the pump. + +Sorry about that. + +Here is the pump and we will come down. + +It also takes care of the forward and overhead +window mounts around the window for thermal + +control. + +And the hatch is just a way to keep those +thermally stabilized. + +Back in the early flights, we had something +called DFI, development flight instrumentation. + +It was a special instrumentation package. + +It was also liquid cooled. + +And then this is the heat exchanger to the +spacecraft system. + +It is a Freon system. + +This is where the main heat is rejected right +here. + +On the other side of this you've got cool +liquid. + +It turns out this is water. + +We go through the liquid cooling garment which +is the spacesuit cooling garment, the water + +chiller, go through the cabin heat exchanger +to cool the cabin and condense the water out + +and then back to the pump. + +I failed to mention the IMU. + +It has triply redundant fans. + +It pulls air through it. + +And that is also cooled by this gas stream. + +Anyway, this is the cabin thermal control +system. + +These functions, I just said each one of them +so I won't repeat them. + +Cabins circulating liquid cooling loop. + +As I mentioned, water is the coolant. + +Water is actually a very good coolant. + +And, if you have any requirements that push +you that way in your designing thermal control + +systems, you like water. + +Water is completely nontoxic so it can be +around the crew. + +Leaks don't make any difference. + +It has a very high CP. + +It's a really good fluid. + +The problem with water is freezing. + +You don't want to freeze it and you don't +want to get it so hot that it turns into steam. + +But if you can stay within the boundaries +it is a good fluid. + +And that is what this is. + +Redundant pumps, I showed you that on the +schematic. + +The liquid gas heat exchanger, I showed you +that before. + +Cold plates for electronic cooling and the +window hatch mount. + +The circulating gases that I mentioned for +the avionics, the cabin gas was used as a + +coolant. + +You saw the redundant fans and the doubly +redundant fans. + +I mentioned earlier, and someone commented +on it, that the promise early on was the Shuttle + +could be a less expensive development activity +if we used off the shelf avionics, the kind + +that aircraft use. + +And that's a good promise. + +It turned out that that's not a very good, +not as good a solution for thermal control + +as liquid cooled. + +Liquid cooled is a much more efficient way +of providing a heat sink to electrical equipment. + +When you blow the cabin gas through it then +you end up with the problems of if you change + +the pressure in the cabin, which we talked +about. + +That can effect cooling. + +Also you have to put out a lot more power. + +You have to blow a lot more gas than you do +power to move the liquid around, so it's not + +a very good thermal solution. + +And actually the promise of less expensive +avionics I don't think was actually fulfilled, + +although that's somebody else's topic and +not mine, because I think everything was pretty + +well custom. + +It did potentially complicate the thermal +control system for a good goal. + +And how well that goal was met, somebody else +will have to speak for it. + +Another one of the subsystem elements of the +spacecraft. + +Well, we usually take a two minute break when +we're about halfway through. + +Certainly. + +Why don't we take our two minutes now and +then we will pick it right back up? + +[AUDIENCE QUESTION] + +From an engineering standpoint, it is much +better to cool with liquid. + +If you use cold plates, it is much more efficient. + +You get a good reliable heat sink. + +And you can then design your thermal conduction +paths so that out of the avionics box you + +make sure the heat goes to the cold plate. + +And you use a lot less power. + +You can pump water a lot more efficiently +for the cooling capability than you pump gas. + +Is that what happens on the Shuttle now or +do you have a mixture? + +[AUDIENCE QUESTION] + +This is the air-cooled part of the loop and +here are the cold plates. + +Let's get the class back. + +Thank you very much. + +I am sorry. + +Did you see what I was pointing at here? + +Yeah, you put both. + +Yeah, and this is one bay. + +And they have both cold plates and the air-cooled +here, here and here. + +There they are. + +Of course, when you go outside the vehicle +there is no more air so all the external equipment + +is cold plated. + +Was there another question? + +What kind of design changes would you have +to make in order to go strictly to completely + +liquid cooled electronics? + +Well, if you're trying to use off-the-shelf +and it is air-cooled already, there is a cabinet + +right there full of it. + +If it is air-cooled already then you have +to stay with that concept. + +If you're custom designing then, from the +very beginning, you say I'm custom designing + +this to be liquid cooled. + +And then the internal design is such that +there are conduction pads to the base plate + +so that it can be cooled. + +OK. + +I guess previously to that all of our spacecraft +were liquid cooled. + +Apollo was, wasn't it? + +Yes. + +Because you had to be able to take those spacecraft +down the back? + +Right. + +We evacuated the cabin both in the Command +Module and the Lunar Module. + +And Gemini, too. + +This is the spacecraft active thermal control +system. + +This is the vehicle level. + +So now, even though we're still under this +ETCLSS, we are not talking the classical environmental + +control anymore. + +This is a bigger picture. + +Also the reason the word active is stuck in +here was a left over from previous programs, + +too. + +For example, on Apollo we had several heat +rejection systems. + +Not a single one. + +And we also did a lot of passive thermal control +on Apollo. + +We had a mission mode called "barbeque" which +is basically you roll the vehicle very slowly + +so you normalize the environment. + +If you leave the same side toward the sun +all the way to the moon that side gets really + +hot. + +This is the active system to get away from +heaters and/or vehicle level control. + +There is an on-orbit. + +We have a radiative heat sink. + +We also have an evaporative heat sink on orbit. + +During ascent and entry we have two heat sinks, +both of which are evaporative. + +We have a circulating liquid system. + +We take heat from the cabin, from the fuel +cells, hydraulics, all the cold plate avionics + +and electronics, and payloads, we do cooling +for payloads. + +All of these are the functions of the active +thermal control system. + +This, as you notice, is a lot busier than +some of the others have been. + +You will notice the radiators here on the +side wall. + +This is the doors. + +When closed up there are no radiators. + +When opened the underside of the payload doors +are your radiators. + +And this is on both side, obviously. + +That same heat exchanger that I showed you +before that interfaces with the cabin is right + +here. + +The cabin load is dumped there. + +Fuel cell load is dumped here. + +The fluid is a Freon 21. + +There is a Freon 21 pump package. + +The payload heat exchanger is here, I believe. + +Mid body cold plates. + +Aft cold plates. + +Each radiator side has its own flow control +system. + +The evaporative heat sinks, one is the flash +evaporator that I've shown you a couple times + +before. + +I will describe it a little better in the +minute. + +It is here. + +It uses water. + +There is an ammonia boiler here that is also +an evaporative heat sink. + +And when we're on the ground there is a GSE +connector for the GSE heat sink. + +[AUDIENCE QUESTION] + +More than you would ever know. + +In fact, this is the most complicated, integrated +thermal test ever run at JSC. + +And I will show you a picture of it in a minute. + +We actually tested all of that together. + +And it all had to work together. + +And it gets worse as we go along. + +I will show you all the integration factors +as we go along, but it changes from mission + +mode to mission mode. + +It changes within mission modes as to how +the system works. + +And I will try to describe that. + +OK, so this sort of gives you the feel now. + +Keep in mind, geometry is going to play an +effect here as to how you plum the system + +up. + +So Freon is running through all of those lines +there to the radiators? + +It will be a little clearer in a minute. + +This is a schematic. + +Let's start at the radiators. + +On a good day, this is doing the job for you. + +All the radiators are getting you nice cool +liquid. + +The radiator uses a bypass system, so you +will see the bypass around the radiators. + +It is good to remind yourselves that heat +load can be tremendously different. + +And the high level mission phases, a lot of +electronics, a lot of crew activity, the vehicle + +is alive and pumping out the power and, therefore, +pumping out the heat. + +If you ever did one of those 28 day missions +we talked about, which was a spec requirement, + +you can imagine this vehicle is almost quiescent. + +It is doing very little. + +You're trying to link them the mission. + +So you're doing hopefully experiments or something +in SpaceLab. + +You're doing something else. + +The vehicle is not working for you very hard. + +Just as an example, we have five computers. + +And we use all five during ascent and entry, +the active phases for safety, but once you're + +on orbit, when you have a long mission like +that, you actually power down all but two + +of the computers. + +That is just it. + +And there are a lot of other systems which +you power down. + +And that way you're limited in missions by +the electrical energy which is limited by + +the amount of hydrogen and oxygen you can +carry for fuel cells. + +So, by powering down, you extend your mission. + +And, of course, you will also reduce the heat +load. + +And, when you reduce the heat load, you've +got to find some way to make that same radiator + +work for you at a very low heat load. + +So it has the capability of getting rid of +a lot of heat. + +If you don't want it to get rid of that much +heat, because you don't have it, then you + +have to go to bypass system. + +Anyway, the next thing in the loop is the +GSE heat exchanger. + +On the ground you don't have radiators working +so you use the GSE heat exchanger. + +Then there is the ammonia boiler. + +When you reenter the ammonia boiler gives +you the ability to operate with an evaporative + +heat sink prior to the connection of the GSE, +and so it is part of the thermal control system. + +The next is the flash evaporator. + +And you'll notice there are two flash chambers +here. + +One is called the high load and one is called +the topper. + +And I will talk about that a little more later. + +Then the nice cool liquid, however it was +cooled, all these cool it. + +However it was cooled is then available for +the vehicle. + +And there is one more little heat load, and +that is the cryogenic oxygen that we're bringing + +in. + +We also warm it up with this coolant loop. + +So the flow then goes to the aft cold plates. + +And then the flow also goes to the cabin heat +exchanger and the payload heat exchanger. + +You notice these are either or. + +And that's because sometimes you don't even +have a payload heat exchanger use so you don't + +use it. + +Sometimes you have a lot of use for it. + +And maybe, for example, SpaceLab and Space +Station have kind of an arrangement. + +You wouldn't be in the cabin as much so you +can divert that. + +It allows you to use the capacity in either +of two places here. + +Then you come on down and come through your +pumping package, there are redundant pumps. + +Then you go the fuel cell heat exchanger because +now you've used the nice cold fluid up. + +And so the fuel cell can stand the warmer +temperatures. + +Also some cold plates. + +Now, it might have occurred to you, it occurred +to me, why did we waste our nice cold fluid + +on these cold plates? + +Why didn't we put those cold plates down here +so we could have had more cold fluid for our + +cabin heat exchangers? + +And the answer is geometry. + +Those are way in the back. + +The cabin is in the front. + +After you've come forward from the flash evaporator, +which is in the back, to the cabin, you don't + +want to go back to pick this up. + +You wouldn't want to have to go back to the +back of the vehicle and then back forward + +again, so this is a geometry problem. + +We have cold plates here. + +We also have cold plates here. + +They come forward. + +The hydraulics heat exchanger is the last +thing on the loop and then back to the radiators. + +We will talk about that a little more. + +The functions of the active thermal control +system. + +Collect the waste energy from all the systems. + +We just talked about that. + +And rejected radiatively to space. + +That is our first choice. + +Our first choice is to use the radiators. + +It turns out that the radiators in some heat +load environments don't do the job. + +You have a high load and a bad environment, +you cannot get rid of all the heat. + +Also, we are producing a lot of water, so +something constructive has to be done with + +this water. + +The fuel cells are pumping it out because +every time you make a kilowatt you've got + +more water to use. + +So we decided to augment the space radiators +with the evaporative heat sink at these high + +load cases. + +This gives us an ability to accept a radiator +system that cannot really do the job by itself + +but make it completely adequate for some of +the low heat load cases, but in the high heat + +load cases then it is augmented by water. + +Now, when you want to get rid of water and +you don't have some of this bad environment + +you can actually throttle the radiators down. + +And, if you throttle them down, then you force +the evaporative heat sink to come online and + +do the job for you. + +In other words, you change the set point on +the radiator. + +Normally we use 40 degrees set point. + +If you change it to 56 degrees and let the +water take you from 56 back down to 40 then + +you artificially get rid of water. + +It is a good water dump system. + +During ascent, over 100,000 feet we use the +water boiler. + +The flash evaporator. + +Not a water boiler. + +That's a Freudian slip, I guess. + +The Apollo had what's called a water boiler. + +It was a nightmare. + +We said never will we do that again, so we +ended up with a different design for the Shuttle. + +The reentry system below 100,000 feet is ammonia. + +It will carry you all the way to the ground +and on the ground until you get the GSE. + +Water won't carry you because water won't +evaporate less than 100,000 feet, but the + +ammonia will so that's the reason it is there. + +Let's talk about the radiators themselves. + +The two payload bay doors are a mirror image +of each other. + +They are radiators on each side that are exactly +mirror image. + +I don't know what happened there. + +Anyway, this is supposed to say that the radiators +on these two sides are mounted and are plumbed + +in two separate cooling loops. + +The reason for that is there is always a redundant +loop. + +Obviously, you have to be able to take a failure +and still have a good system. + +If you run both loops through both radiator +sides and you took some sort of collision + +hit then you could wipe out both of your cooling +loops in one hit. + +And so that is unacceptable. + +By plumbing the systems up with mirror image +radiator systems on different loops then you + +can still use the capacity together. + +But if you lose one side you still have half +your capacity left. + +And plus you have your evaporative heat sinks +to make up the difference. + +So we can survive with a door out. + +I mentioned the dual set points before. + +I also mentioned the bypass thermal control. + +I mentioned the dual set points, 40 and 56. + +40 is our normal. + +If you're trying to burn up some water you +go to 56 and you use the difference in water. + +The radiators, we have two different kinds +of radiators. + +We have the single-sided that are on the back +of the vehicle and some two-sided ones on + +the front of the vehicle. + +The reason for that is when you open the door +you expose the underside of the door. + +If you have radiators on the underside of +the door then you've exposed your radiators. + +But if you lift the radiator panel off the +door, because the doors go way down, then + +you can see the underside. + +It's not as good, you don't get a full view +of the heavens, but it does get rid of heat. + +And so we needed that extra capacity. + +On the front four panels they are the two-sided +and on the back four they are single-sided. + +The radiators themselves are made out of a +honeycomb aluminum structure. + +The tubes were imbedded in the structure so +that the surface was smooth, and that was + +because we wanted to use a silver Teflon tape +for our thermal control coding. + +For previous vehicles we always painted the +radiators, painted them white. + +If you look at the alpha epsilon white paint, +it is pretty good. + +I think Apollo was 0.18 alpha and epsilon +about 0.92. + +That's pretty good. + +The market had moved along. + +Technology had advanced and there was not +the silver Teflon out there. + +And what the silver Teflon does is the silver +gives you the reflection which is good and + +the Teflon gives you the radiation which is +good, so you get the best of both worlds. + +Silver Teflon was about 0.05 epsilon and about +0.88, 0.9, something like that. + +You lost a slight amount in epsilon and gained +a lot in alpha, so basically you could ignore + +the sun which is what you'd like to do, is +ignore the sun. + +It turned out the silver Teflon had some issues. + +We tested the radiators. + +The radiator was not a slam dunk with eight +panels, four of which are two-sided. + +Effectively you have 12 panels. + +You have fluid going through those in parallel +tubes. + +You're trying to guaranty that the fluid all +goes where it's supposed to go. + +And, therefore, the viscosity of Freon, which +is very low, analytically said it was all + +right. + +But we wanted some testing to prove it so +we did test the entire radiator system. + +And, in that test, all the silver Teflon fell +off. + +It is a really good thermal coating but it +doesn't seem to be very practical. + +It turned out that the problem was adhesive. + +We did a little adhesive work and the materials +people came up with a Permacel that worked + +perfectly. + +They have never come off again. + +In fact, we get 10, 12 years out of the radiators, +lots of time. + +The problem that the Permacel couldn't solve +was beneath the tape you could get very small + +little out-gassing of the materials. + +Almost all materials outgas some. + +Basically, we would put bubbles underneath +the tape. + +We went to a perforated. + +There are millions of little holes in this +tape. + +And it is placed on the vehicle and it stayed +on just fine. + +It wasn't very long, though, that people began +to worry about the focusing of this silver, + +that the doors are curved upward. + +And so there is a focal point there that is +a very, very hot point. + +And there was concern that that's really not +a good thing to have. + +If we could make the surface less specular +and more diffuse without losing the alpha + +and epsilon we would have a better design. + +And so they dimpled it. + +Now we have Permacel dimpled, perforated silver +Teflon tape. + +It works great. + +The flash evaporator. + +Water is the flash evaporator's evaporant. + +This was a brand-new design. + +The water boiler on Apollo was no good. + +It was a problem. + +The flash evaporator is a very simple concept. + +You have a chamber. + +You run your coolant around the chamber that +you want to be cooled. + +And you spray water on the walls of the chamber. + +And, if the pressures are all right, the water +will flash. + +You won't get ice. + +It will go straight to steam. + +Steam will go overboard and it will all be +wonderful. + +And if you can convince a program manager +of that good luck. + +Anyway, the way to convince a program manager +is to show him good test data. + +During the development, we developed this +process of spraying the walls and not getting + +water carryover which will obviously freeze +up your steam duct. + +Which you don't want. + +But, as the design evolved, we had to get +more sophisticated because we needed this + +flash evaporator to burn up the extra water +when we didn't need the fuel cell water. + +And we did that with that 40 to 56 set point. + +And so we needed a small evaporator that could +handle that. + +It was called the "topper." It tops off the +radiator. + +But when the doors are closed there is nothing +else to get rid of your heat, now you need + +a loss of capacity. + +And so the second chamber was the hallowed +chamber. + +Together they do the whole job. + +When the radiators are working only topper, +you can come home with this system functional + +and make it home. + +It turns out we never did freeze up the steam +duct so that part was good. + +It turns out that we had some freezing in +the chamber. + +And, in fact, we had to develop a process +that acknowledged that that could occur. + +And how would we flush it? + +It is called "flushing." And so we did develop +a process. + +And it has never failed. + +The flushing process always works. + +And we have had on several occasions, I probably +cannot count them for you, but four of five + +times maybe over the Shuttle flights we've +had some freezing inside the cavities. + +There is a non-propulsive overboard vent. + +That was the one going out both sides for +the topper because it could be used for very + +long times during the mission and you might +be pointing or whatever you might be doing. + +But when you're coming home the high load +is just a big out the side of the vehicle + +type duct. + +The ammonia boiler, its heat sink is ammonia. + +As I mentioned before, it evaporates all the +way to the ground where the water won't. + +The redundant boiler is here. + +Up here there are no redundant boilers. + +These two chambers have redundant everything. + +They have redundant feed water systems and +redundant control systems, redundant spray + +nozzles, redundant everything, but the chamber +is a chamber. + +You get what you get. + +They are redundant boilers is the way the +ammonia boiler gets its redundancy. + +It was designed to be utilized during entry +and on the runway until the cooling is available. + +It turns out that we don't do that anymore. + +It turns out operationally we learned that +if we cold soak the radiators before we shut + +the doors and then bypass them and come home +on the flash evaporator that there is a lot + +of heat capacity still left in those radiators. + +There is a lot of fluid out there and it is +cold. + +And so we can actually go all the way to wheel +stop on the radiator. + +And so at 175,000 feet we start flowing the +radiator. + +And at 100,000 feet the flash evaporator is +off and we cold soak all the way home. + +And after wheel stop the ammonia boiler cranks +up. + +I mentioned the Freon 21, the low viscosity. + +We got an excellent performance out of that. + +The low viscosity is really, really important, +as much parallelism as we have. + +I didn't really give you the numbers. + +In the single panels we have 26 tubes. + +In the two-sided panels, I believe, there +are 66 tubes. + +Lots of tubes. + +Lots of parallelism. + +It is awfully easy to get flow instability +in a thermal system like that but the Freon + +loop does great. + +We have redundant pumps, all liquid heat exchangers +and cold plates. + +This is that chamber that I told you. + +If you can look right down here, this is one +person. + +In fact, there is a radiator panel. + +This was during buildup. + +Twice we tested the flash evaporator in this +environment once as part of the integrated + +system with all the radiators and once by +itself. + +And twice we tested the radiators, one as +part of the integrated system and once by + +themselves. + +So we did essentially three large tests. + +And the one that had the entire system in +it, had all the cold plates, had everything + +in it, as I said, is the most sophisticated +thermal test we've ever done at JSC. + +And it proved that the system could work. + +It also proved that we had to tune the flash +evaporator nozzle because it was wrong. + +But we did get the data, we did prove it was +wrong and we got it re-machined. + +A machine out of columbium, somebody else +will have to answer why. + +And so it was a problem for Aaron to go get +us another one, but it fixed it and it was + +successful. + +[AUDIENCE QUESTION] + +You can have a command module and a service +module and a stack configuration in side that + +chamber. + +And it had a solar and full vacuum. + +[AUDIENCE QUESTION] + +It was a manned chamber then. + +It is not now. + +After Apollo-Soyuz, it hasn't been manned +since then. + +It's still available for testing but is not +manned. + +It has a sister chamber 100 feet that way +where all of the EVA testing is done. + +A good example, I think, of how the Shuttle +Program built on a lot of Apollo-- The same + +thing at the Cape where a lot of the launch +hardware was adapted is the Shuttle Program, + +you know, you heard about the budgetary constraints. + +The Shuttle Program never could have afforded +to build something like that. + +But luckily a lot of this equipment was built +during Apollo when the money was much more + +available. + +If you have been keeping count, we're getting +toward the end here. + +I did want to mention, before we left the +main orbiter systems, that there was some + +rotating equipment life testing that we did +for the program. + +The equipment we're talking about here is +the cabin fan, the water gas separators, the + +avionics bay fans, cabin coolant and the vehicle +coolant pumps. + +The life requirement was 100 missions, and +that was calculated by somebody to be 20,000 + +hours. + +If you could show 20,000 hours of successful +operation, you had the design life of the + +hardware. + +We set up a laboratory to run the equipment. + +It was obviously a low-maintenance lab. + +We collected data and checked in the room +occasionally to see if everything was all + +right. + +It turned out that all the equipment passed +the 20,000 hour requirement. + +We did learn something, though, that some +of that stuff was so noisy. + +Oh, it was noisy. + +There was some work done on some muffling, +but the hardware itself was all good. + +We are at the end. + +Yes. + +Were there noise requirements [AUDIENCE QUESTION]? + +Yes, there was a cabin noise spec. + +And, yes, it had to be met. + +And I don't remember how it was met. + +We put mufflers on some of the equipment. + +Maybe some insulation inside of the ducting, +I'm not sure. + +If we have time, COHEN: I will tell a little +anecdote here. + +I chaired the Change Control Board. + +[NOISE OBSCURES] + +The medical organization came to see me and +said that the cabin was very, very noisy and + +it was going to really do a detriment to the +astronauts. + +And it was very expensive in terms of dollars +and weight to really get all the cabin fans + +and cabin environment down to the level they +wanted. + +I thought for a moment. + +I go out to California a lot. + +I go out to Rockwell and stay in motels that +are on the Los Angeles freeway. + +And I said you don't see me worried about +my ears in staying in those freeways and not + +being able to sleep and having all that noise. + +And the doctor looked at me for a moment and +said, well, you're already deaf. + +And I said what did you say? + +But we did have to make some modifications +of it to actually reduce noise. + +Let me interject one item. + +I think somebody asked the issue about the +IMU. + +We decided to pick the IMU off the shelves, +and it was air-cooled, to really do it right. + +If we would have done it right, we would have +picked an IMU which was compatible with liquid + +cooling rather than redesign it. + +But we decided to stick with the IMU that +was air-cooled. + +Whether that was the right decision to make, +I don't know. + +It seemed like it was because I think we've +only had one problem with an IMU. + +I don't think we've had many problems with +the IMU. + +But that is a little anecdote that I thought +of. + +That's a program manager's trait. + +Probably the air-cooled IMU was a less expensive +option. + +It might have cost a little in terms of thermal +efficiency, but that is only energy power. + +And power was available so it was a good tradeoff. + +This is the last of the subsystem areas. + +This is the EVA airlock support. + +The Environmental Thermal Control and Life +Support System does support the airlock. + +It maintains the cabin pressure and composition +during the airlock repress and depress. + +This is really a requirement back on the ARS +and the pressure and composition control system + +because airlock use basically dumps cabin +gas and then you repress the airlock. + +It is a requirement that you cannot upset +the cabin while you're doing the EVA function. + +We also provide the service and cooling umbilical. + +If you have any kind of mental picture of +being in the airlock, the crew is connected + +with cooling and oxygen through an umbilical +so they don't use the consumables in their + +spacesuit. + +And so that is provided by the ETCLSS. + +Heat rejection, the crew wears a liquid cooling +garment. + +And the cooling for that is done by the vehicle +until you go EVA, of course. + +Then the recharge. + +We supply the backpack O2 recharge from the +900 PSI cryo. + +We supply the water to recharge for the sublimator. + +NASA is overrun with acronyms. + +EMU is extra vehicular mobility unit, which +means nothing but spacesuit and backpack. + +So the spacesuit and backpack uses an evaporative +heat sink and it uses a sublimator. + +And the idea there is it's a device that exposes +a layer of ice to space and then it sublimates + +and you get your cooling from that as opposed +to putting a liquid water on a surface and + +flashing it. + +Anyway, that has to be serviced. + +That water is provided from the system. + +And then the condensate that the crew brings +back, EVA, that's a sweaty job. + +That condensate goes back into the system. + +So the airlock support is another part of +this system. + +In fact, that is the sixth part. + +So we are through. + +This is a picture of the airlock. + +Not really the airlock. + +This is the test chamber that we built to +put the equipment in. + +You'll notice it has the right hatch in it. + +And, if you can recall back an hour and a +half ago, I showed you a picture where there + +was this hatch basically on the backside of +the test chamber. + +We hook those together. + +Because, as I said, as you depress and repress +the airlock it affects the cabin. + +So we needed a test environment that had both +those simultaneously. + +But the difference is this has to go all the +way to vacuum. + +So we connected this to our vacuum system. + +And, when the crew is inside this, it is a +manned vacuum test. + +And when the crew is inside the other test +chamber it is basically sea level or, at most, + +8 PSI would be the lowest it would ever be. + +And I think the last picture is a spacesuit +inside the airlock. + +And this is just a little cutaway showing +the airlock. + +This was mounted on the back of that chamber +you saw earlier. + +If you bring that picture back up, I will +talk to that for just a minute and then we + +will have some questions. + +Before every flight, one of the things that +we do is that every EVA crewmember takes his + +or her spacesuit into that EVA test chamber, +into the airlock test chamber so you actually + +get a chance to take your own suit down to +vacuum. + +And particularly, before you do your very +first EVA, it is really a confidence builder + +because the physical sensations that you get +in a suit -- And remember you're at about + +a 4 PSI pure oxygen environment. + +Your body, the inside of your mouth feels +a little different. + +There are funny sounds with the fans inside +the suit. + +The sorts of things that you don't want to +experience the first time when you actually + +go outside into space. + +It is much better to do it here in a controlled +environment where if there is a problem -- Actually, + +you are supported because of the weight of +the suit. + +It doesn't look like there is anybody in this +suit. + +But, when you're in this suit, you're actually +supported by a cable to the ceiling of the + +chamber which is on quick release bolts. + +You're suspended up here. + +And, if you ever have a problem, they can +release this, repressurize the chamber within + +about 30 seconds. + +I think that's the limit for a manned rated +chamber. + +You're going to be able to repress in about +30 seconds and then just lift you out, suit + +and all from the top, and get you out of your +suit and get you to the medics. + +This is just an inverted bell jar. + +The hatch is not sealed. + +When you depress it just like pulls it out +and seals due to the pressure difference. + +You just lift the top off. + +Yet another example of the extensive testing +that we go through before every mission. + +I might add one more thing, which I forgot +actually to add earlier. + +The manned rating is a term used in manned +spacecraft which means that you've specifically + +tested it and said that its design is worthy +of supporting a human. + +The airlock had to provide that function. + +So Aaron was faced with man rating the airlock. + +And manned test capability is very scarce. + +In fact, JSC may be the only place anymore +that can do it. + +Anyway, we volunteered to do that as part +of our test program as a programmatic requirement. + +Not as testing or watching or confirming anything, +but as a prime part of the test program was + +the manned rating of the airlock. + +And that was done in Houston. + +That is an interesting thought. + +If my memory serves me correctly, one of the +problems we had in the early part of the Manned + +Space Program was doing some chamber runs +McDonnell-Douglas with a two-gas system where + +we actually lost the heat [NOISE OBSCURES] + +in the chamber and almost lost a test subject. + +And that was when Apollo decided to go to +100% oxygen. + +And that is what led up to the fire on the +pad. + +It went to 100% oxygen at 16 pounds per square +inch with an invert over the hatch for another + +reason. + +And that is really if you can realize that +100% oxygen at 16 PSI everything burns. + +Stainless steel is not self-extinguishing +at 16 PSI. + +And, of course, that's what we were up when +we had the Apollo I fire on the pad. + +It was a function of doing some test work +with the combined atmosphere. + +So you have got to be careful that sometimes +you don't over-react the thing. + +Then we went back to a different type of atmosphere. + +Did you have a question? + +The systems you've been describing today seem +to take up a lot of space in the Orbiter like + +other systems. + +How did you negotiate and manage other subsystems +for the space and the volume in the way that + +you wanted? + +That is a good question but you're asking +the wrong person. + +We are the government. + +We hired a contractor to design the vehicle. + +Now, the design aspects of it, the philosophy +of it, the functionality of it we were very, + +very integral with. + +We watched, we audited, we said that looks +smart, but we didn't go and say put that cold + +plate here and put that heat exchanger there. + +The vehicle integrated design was Rockwell's. + +Let me tell you how it was done. + +Actually, in those years we didn't have CAD/CAM +systems. + +What we did is used everything on mockups. + +We did mockups. + +The system was laid out of what to do and +the functions of what they had to do and the + +plumbing. + +And this was all laid out on a mockup. + +And basically that was how it was negotiated +in terms of what you need. + +In today's environment you wouldn't do that. + +You would use electronic capability. + +You would use your CAD/CAM systems. + +You would actually draw it up on your computer. + +In fact, the 777 was built that way. + +The 777 at Boeing, they didn't use hard mockups. + +They used electronic mockups. + +And that is what we would do today. + +And it would be much easier. + +You would probably call all the engineers +together. + +You would sit down and show how the equipment +was laid out, get a satisfactory buyoff on + +it and do it much more rapidly and much more +quickly. + +In the future, what you will be doing is actually +use a CAD/CAM system or CAD system to actually + +negotiate the space you need for it. + +That is a good question. + +And it was based on purely that you would +get drawings, mockups, go out and lay it out + +in a soft mockup or hard mockup. + +You would get the engineers to come out, the +manufacturing people to come out and say this + +is how it is going to look and then get a +buyoff on it. + +Today you wouldn't do it that way. + +You would do it all electronically so it would +change. + +Well, let me ask you a question. + +Of all the work you've done in the Shuttle +what was your biggest concern in getting ready + +to fly or during the flight? + +What did you have the biggest concern about? + +I was young and confident. + +I don't know that I had a specific area that +I was really concerned about. + +Like these people right here, right? + +Young and confident. + +I did recognize, though, but it did result +in the integrated tests that I showed. + +I did recognize that we had the most highly +integrated thermal control system ever conceived. + +And it had, as I said, modes within modes. + +It changed modes with respect to the vehicle +phases. + +It changed modes with respect to operation. + +We had 9 PSI that went to 10.2 PSI. + +We had 8 PSI. + +We had thermal control loops, ammonia boilers, +flash evaporators, so I did recognize the + +sophistication. + +In fact, we proposed early on to use that +large chamber in an integrated vehicle test. + +Not we, me, but the big we looked at an integrated +test like the Command Service Module was tested. + +And that was viewed to be impractical. + +It was cut it off at the bulkhead. + +You could do the forward cabin part and then +do the aft section, but that was viewed to + +be impractical. + +But it still was a very integrated design. + +All the systems engineering that was there +created that inner-dependency. + +And I think I was smart enough to know that +there was certainly some potential risks there. + +Remember in the very beginning of this I talked +about ownership of all the technical aspects? + +We had ownership. + +We believed that what we had done was prudent, +appropriate, and we believed it would work. + +It wasn't like you bought something and you +hope it works. + +Can you say a word of what you think, this +is looking in your crystal ball, about the + +CEV? + +Do you think it's going to have a very similar +type system or have you thought about that? + +Well, we hope so. + +Our new administrator has sort of back to +the grassroots philosophy, or at least right + +now. + +And so we hope that the CEV will be developed +with a lot of government involvement, that + +the government will have ownership again of +the technical aspects of the design. + +If that happens then I think a lot of the +experience that is around and a lot of the + +free-thinking and the independence that the +government can bring to that, there is another + +school of thought that says keep the government +out of the way and let the contractor go do + +their thing. + +And, obviously, you wouldn't get that position +from me but there are people that believe + +that's the right way to do it. + +Do you think the system will look pretty much +like this or similar to it? + +Well, similar, yes, I do think so. + +I believe that the very tight schedule for +the CEV is going to put a lot of pressure + +on the program manager to go with the tried +and true. + +So I don't think there is going to be innovation +that has risk with it. + +Maybe there will be innovation that is good +engineering, but I think the innovation with + +risk will be very much minimized. + +Because taking Shuttle offline in 2010 there +is going be a lot of pressure to get this + +vehicle finished. + +I think that is going to breed some conservatism +on the design side. + +We talk about considering operation while +you're doing the design, but there were always + +things once the design was made. + +Well, like you mention, once we came up with +a requirement for a 10.2 cabin we had to develop + +workarounds. + +And one of the other things that after the +system is designed, we then start to figure + +out how can it fail and work on malfunction +procedures. + +And I know that the malfunction procedure +for loss of two coolant loops that was probably + +the worst simulation case that we ever had +to deal with. + +I am curious to get your opinion. + +Walt described how we have two independent +cooling loops so that in principle one failure + +won't take them both out. + +Now, I don't remember what it was, but they +did discover a single point failure somewhere + +in there which I think was corrected but where +you could have lost both of the cooling loops + +with a single failure. + +The only failure I remember is one that John +Young used to worry about. + +It had to do with if you did lose a radiator +that that could bleed your accumulator down. + +And so they did add an isolation valve so +they can isolate the radiator side. + +But the idea was to obviously not lose your +fluid with a single hit. + +That even though you have a nice completely +functional thermal control system it is useless + +because it has no fluid. + +We did have an emergency de-orbit procedure +for loss of two Freon cooling loops. + +And, of all the things that we practices, +that was the hairiest because it was absolutely + +time critical. + +At this point, you have no way of getting +heat out of the cabin so you cannot ultimately + +cool your electronics. + +The cabin gets hot, your electronics get hot +so you have to do an immediate de-orbit. + +Hopefully you're within range of a landing +site. + +And then you turn off all the equipment that +you can possibly turn off, including most + +of your computers. + +And, when you're riding down through entry, +you basically watch the temperature of the + +computer. + +And, as each computer would get up to its +failure temperature, you would then switch + +on the next computer, transfer the data, you +know, turn off the computer which has just + +about failed, and hopefully you could make +it to the ground. + +And I know the instructors that would lead +us through this exercise said that the information + +they had gotten from the thermal analyst was +that nobody was really sure whether we could + +make it. + +I don't know what your opinion was or not. + +We practiced it. + +But obviously, I think I've told you, nobody +has ever died in a simulator. + +But you never know whether the thermal model +that they use in the simulator is really going + +to duplicate the way the Shuttle is going +to behave in an absolute emergency situation + +like that. + +We survived in the simulator but I don't know +what your feeling is. + +Well, we do address the thermal model accuracy. + +We do specific testing to validate the thermal +model so we do have pretty good confidence + +in those. + +But the real issue in overheat is that when +does a piece of equipment stop working in + +an overheat situation? + +I mean there is no magic number. + +It is not like at 143 degrees it is OK and +144 it is not OK. + +And it varies with age, it varies with equipment +and it varies with a lot of things. + +So there wasn't really a precise answer as +to how long you could keep everything functional + +and come home. + +Yes. + +You talked earlier a little about oxygen and +nitrogen mixing in the cabin. + +I was wondering if there is a way to really +study that on the ground since you're not + +in a DoD environment. + +How do you know there are not pockets of nitrogen +sitting around that an astronaut can stick + +his heat into? + +Very good. + +I just forgot to mention that earlier. + +The testing that we ran, we had to set it +up very carefully. + +If you notice, there is a flight deck and +a mid-deck, so obviously buoyancy is going + +to mix that stuff for you. + +What we did is set up a thermal condition +where less than one degree thermal gradient + +everywhere in there had to exist before we +ran the test. + +And that was to guaranty that we had no help +from the naturally induced circulation. + +But you are absolutely right. + +That test would have been a useless test without +neutralizing the gravity effects. + +And actually the first time that I did the +spacesuit test in there we actually used the + +10.2 protocol. + +So I actually had to go in the day before, +take the cabin to 10.2, spend the night and + +then we could do just a 40 minute prebreathe. + +For most of the other tests, when you go in, +in order to avoid the inconvenience and expense + +of staying through the night, you go in early +in the morning. + +And then you're coming right from a sea level +environment. + +So, before you go down to 4 PSI in the suit, +you actually have to prebreathe pure oxygen + +for four hours. + +As Walt said, that was the alternative. + +You basically just get in your suit. + +You can either bring a book and read your +book or they will pipe music into you if you + +want to give them a CD, or I guess there was +an audiocassette in those days, or they have + +a little black and white TV monitor. + +And you just sort of sit there for four hours. + +And the problem is you're not allowed to go +to sleep. + +That would be the easiest thing, but they +want you actually to move around because when + +you're moving your muscles you're actually +then doing a better job of de-nitrogenating. + +So you have to stay awake. + +And if you don't say anything for more than +about 10 minutes they will pipe something + +in and say, Jeff, are you awake? + +But this was a very, very useful facility. + +I mean they used it for all different sorts +of things. + +And I guess that was the one new facility +which was built for the Shuttle specifically. + +Yes. + +Jeff mentioned several times the 10.2 and +I talked about the 9. + +The 9 was the original design, but the issues +with the 9 PSI had to do with the oxygen percentage + +got too high. + +And so there was much concern about flammability. + +The idea was if you could raise the pressure +up some to 10.2 then that would be less of + +a flammability issue. + +But then the problem became at 10.2 that the +suit at 4 PSI was too much of a drop. + +If you're in the bends while diving, somebody +mentioned diving earlier, scuba, you could + +usually use a two to one. + +If you don't reduce pressure more than half +you're probably OK. + +You're probably not going to get the bends, +but half of 10.2 is not 4. + +And the suit is at 4, so there was that issue +again. + +They raised and bumped the suit up a little +bit and got it up to 4.3 and went to 10.2 + +and developed the prebreathe protocols that +made that acceptable. + +That is sort of how it balanced out. + +That was another operational move later. + +And, as Walt said, you're spending enough +time, once you get in the suit and you purge + +all the nitrogen out, and so you're sitting +in a pure oxygen environment, you've got to + +do a bunch of tests and check out communication +tests and cooling tests. + +You basically are not losing much time by +having to spend 40 minutes prebreathing. + +The whole thing worked out pretty well. + +And it will be an interesting question on +how they designed the CEV because the CEV + +has to be compatible with docking to the Space +Station which works at a sea level environment. + +But, on the other hand, if you're going to +take the CEV into a situation where you want + +to do a lot of space walks, you probably want +to be able to operate it at more like 8.5 + +or 9 PSI so that you can go right into a spacesuit +without an extensive prebreathe. + +And, of course, people are always trying to +figure out could we design the spacesuit to + +work at a higher pressure? + +But then you give up maneuverability. + +We will talk about that in another lecture +that I will be giving on EVA systems. + +Walt, thank you very much. + +I enjoyed it. + +[APPLAUSE] \ No newline at end of file diff --git a/B7iFcW8USjQ.txt b/B7iFcW8USjQ.txt new file mode 100644 index 0000000000000000000000000000000000000000..8bc249b166cc9563dfb0d9fb7da838b02461096b --- /dev/null +++ b/B7iFcW8USjQ.txt @@ -0,0 +1,7427 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +to view additional materials from + + align:start position:0% +to view additional materials from + + + align:start position:0% +to view additional materials from +hundreds of MIT courses visit MIT open + + align:start position:0% +hundreds of MIT courses visit MIT open + + + align:start position:0% +hundreds of MIT courses visit MIT open +courseware at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu all right so enzymes of + + align:start position:0% +ocw.mit.edu all right so enzymes of + + + align:start position:0% +ocw.mit.edu all right so enzymes of +course are catalysts and that leads us + + align:start position:0% +course are catalysts and that leads us + + + align:start position:0% +course are catalysts and that leads us +to our next unit which is kinetics and + + align:start position:0% +to our next unit which is kinetics and + + + align:start position:0% +to our next unit which is kinetics and +it's our next unit and in fact our last + + align:start position:0% +it's our next unit and in fact our last + + + align:start position:0% +it's our next unit and in fact our last +unit of the semester so we're going to + + align:start position:0% +unit of the semester so we're going to + + + align:start position:0% +unit of the semester so we're going to +be talking about kinetics uh for the + + align:start position:0% +be talking about kinetics uh for the + + + align:start position:0% +be talking about kinetics uh for the +rest of the semester which sounds like a + + align:start position:0% +rest of the semester which sounds like a + + + align:start position:0% +rest of the semester which sounds like a +long time but it really isn't all right + + align:start position:0% +long time but it really isn't all right + + + align:start position:0% +long time but it really isn't all right +so we'll switch to today's hand + + align:start position:0% +so we'll switch to today's hand + + + align:start position:0% +so we'll switch to today's hand +out so kinetics and thermodynamics is a + + align:start position:0% +out so kinetics and thermodynamics is a + + + align:start position:0% +out so kinetics and thermodynamics is a +sort of ying-yang you really have to + + align:start position:0% +sort of ying-yang you really have to + + + align:start position:0% +sort of ying-yang you really have to +think about both of them at the same + + align:start position:0% +think about both of them at the same + + + align:start position:0% +think about both of them at the same +time so when you're thinking about + + align:start position:0% +time so when you're thinking about + + + align:start position:0% +time so when you're thinking about +whether a reaction will go forward + + align:start position:0% +whether a reaction will go forward + + + align:start position:0% +whether a reaction will go forward +spontaneous ly you're thinking about + + align:start position:0% +spontaneous ly you're thinking about + + + align:start position:0% +spontaneous ly you're thinking about +thermodynamics and you're thinking about + + align:start position:0% +thermodynamics and you're thinking about + + + align:start position:0% +thermodynamics and you're thinking about +how fast that reaction is going to go + + align:start position:0% +how fast that reaction is going to go + + + align:start position:0% +how fast that reaction is going to go +you're thinking about + + align:start position:0% +you're thinking about + + + align:start position:0% +you're thinking about +kinetics so let's just do a little + + align:start position:0% +kinetics so let's just do a little + + + align:start position:0% +kinetics so let's just do a little +review we've talked about this before + + align:start position:0% +review we've talked about this before + + + align:start position:0% +review we've talked about this before +but it's a clicker challenge so today + + align:start position:0% +but it's a clicker challenge so today + + + align:start position:0% +but it's a clicker challenge so today +let's think back to + + align:start position:0% +let's think back to + + + align:start position:0% +let's think back to +thermodynamics and tell me what stable + + align:start position:0% +thermodynamics and tell me what stable + + + align:start position:0% +thermodynamics and tell me what stable +unstable refers to thinking about + + align:start position:0% +unstable refers to thinking about + + + align:start position:0% +unstable refers to thinking about +thermodynamics and kinetics now + + align:start position:0% + + + + align:start position:0% + +okay 10 more seconds + + align:start position:0% + + + + align:start position:0% + +okay so most people got stability um + + align:start position:0% +okay so most people got stability um + + + align:start position:0% +okay so most people got stability um +when you're talking about stable + + align:start position:0% +when you're talking about stable + + + align:start position:0% +when you're talking about stable +unstable you're not talking about rate + + align:start position:0% +unstable you're not talking about rate + + + align:start position:0% +unstable you're not talking about rate +you are talking about Delta G you're + + align:start position:0% +you are talking about Delta G you're + + + align:start position:0% +you are talking about Delta G you're +talking about the spontaneous tendency + + align:start position:0% +talking about the spontaneous tendency + + + align:start position:0% +talking about the spontaneous tendency +um a chemist if it's around a long time + + align:start position:0% +um a chemist if it's around a long time + + + align:start position:0% +um a chemist if it's around a long time +we're talking about not a being stable + + align:start position:0% +we're talking about not a being stable + + + align:start position:0% +we're talking about not a being stable +but being inert um and in uh in terms of + + align:start position:0% +but being inert um and in uh in terms of + + + align:start position:0% +but being inert um and in uh in terms of +of this one + + align:start position:0% +of this one + + + align:start position:0% +of this one +here for if you're thinking about the + + align:start position:0% +here for if you're thinking about the + + + align:start position:0% +here for if you're thinking about the +Delta G for the decomposition into its + + align:start position:0% +Delta G for the decomposition into its + + + align:start position:0% +Delta G for the decomposition into its +elements that versus the Delta G for + + align:start position:0% +elements that versus the Delta G for + + + align:start position:0% +elements that versus the Delta G for +formation if that's negative um then it + + align:start position:0% +formation if that's negative um then it + + + align:start position:0% +formation if that's negative um then it +would be stable but we want to be + + align:start position:0% +would be stable but we want to be + + + align:start position:0% +would be stable but we want to be +positive for the decomposition all right + + align:start position:0% +positive for the decomposition all right + + + align:start position:0% +positive for the decomposition all right +so let's just look at this up here so + + align:start position:0% +so let's just look at this up here so + + + align:start position:0% +so let's just look at this up here so +again it refers to Delta + + align:start position:0% +again it refers to Delta + + + align:start position:0% +again it refers to Delta +G and label um and inert aers to the + + align:start position:0% +G and label um and inert aers to the + + + align:start position:0% +G and label um and inert aers to the +rate and again when you have a negative + + align:start position:0% +rate and again when you have a negative + + + align:start position:0% +rate and again when you have a negative +Delta G of formation then that makes + + align:start position:0% +Delta G of formation then that makes + + + align:start position:0% +Delta G of formation then that makes +something um + + align:start position:0% +something um + + + align:start position:0% +something um +stable okay so thermodynamics kinetics + + align:start position:0% +stable okay so thermodynamics kinetics + + + align:start position:0% +stable okay so thermodynamics kinetics +we want to think about is the reaction + + align:start position:0% +we want to think about is the reaction + + + align:start position:0% +we want to think about is the reaction +spontaneous but we also need to think + + align:start position:0% +spontaneous but we also need to think + + + align:start position:0% +spontaneous but we also need to think +about how long it's going to take so + + align:start position:0% +about how long it's going to take so + + + align:start position:0% +about how long it's going to take so +rate is important and so if we think + + align:start position:0% +rate is important and so if we think + + + align:start position:0% +rate is important and so if we think +about the average weight uh or average + + align:start position:0% +about the average weight uh or average + + + align:start position:0% +about the average weight uh or average +rate of a ferris uh wheel um I looked it + + align:start position:0% +rate of a ferris uh wheel um I looked it + + + align:start position:0% +rate of a ferris uh wheel um I looked it +up it is uh 31 .4 seconds to spin around + + align:start position:0% +up it is uh 31 .4 seconds to spin around + + + align:start position:0% +up it is uh 31 .4 seconds to spin around +if you're at an amusement park and you + + align:start position:0% +if you're at an amusement park and you + + + align:start position:0% +if you're at an amusement park and you +can think about your experience um uh + + align:start position:0% +can think about your experience um uh + + + align:start position:0% +can think about your experience um uh +sorry that should say imagine one + + align:start position:0% +sorry that should say imagine one + + + align:start position:0% +sorry that should say imagine one +revolution every five seconds or every + + align:start position:0% +revolution every five seconds or every + + + align:start position:0% +revolution every five seconds or every +five hours would be a very different + + align:start position:0% +five hours would be a very different + + + align:start position:0% +five hours would be a very different +experience 5 seconds would be way too + + align:start position:0% +experience 5 seconds would be way too + + + align:start position:0% +experience 5 seconds would be way too +fast you'd probably be throwing up + + align:start position:0% +fast you'd probably be throwing up + + + align:start position:0% +fast you'd probably be throwing up +everywhere in five hours you'd be like + + align:start position:0% +everywhere in five hours you'd be like + + + align:start position:0% +everywhere in five hours you'd be like +oh my goodness get me off of this thing + + align:start position:0% +oh my goodness get me off of this thing + + + align:start position:0% +oh my goodness get me off of this thing +so rate matters and uh chemical kinetics + + align:start position:0% +so rate matters and uh chemical kinetics + + + align:start position:0% +so rate matters and uh chemical kinetics +doesn't measure the rate of ferris wheel + + align:start position:0% +doesn't measure the rate of ferris wheel + + + align:start position:0% +doesn't measure the rate of ferris wheel +except maybe it does if the ferris is + + align:start position:0% +except maybe it does if the ferris is + + + align:start position:0% +except maybe it does if the ferris is +Ferris iron then we might be talking + + align:start position:0% +Ferris iron then we might be talking + + + align:start position:0% +Ferris iron then we might be talking +about its rate if it's uh spinning + + align:start position:0% +about its rate if it's uh spinning + + + align:start position:0% +about its rate if it's uh spinning +around doing things in a chemical + + align:start position:0% +around doing things in a chemical + + + align:start position:0% +around doing things in a chemical +reaction so we might think about the + + align:start position:0% +reaction so we might think about the + + + align:start position:0% +reaction so we might think about the +concentration of Ferris iron changing + + align:start position:0% +concentration of Ferris iron changing + + + align:start position:0% +concentration of Ferris iron changing +with time so chemical kinetics + + align:start position:0% +with time so chemical kinetics + + + align:start position:0% +with time so chemical kinetics +experiments you measure concentrations + + align:start position:0% +experiments you measure concentrations + + + align:start position:0% +experiments you measure concentrations +and think about how fast they're + + align:start position:0% +and think about how fast they're + + + align:start position:0% +and think about how fast they're +changing with time so let's think about + + align:start position:0% +changing with time so let's think about + + + align:start position:0% +changing with time so let's think about +some of the factors that are going to + + align:start position:0% +some of the factors that are going to + + + align:start position:0% +some of the factors that are going to +affect the rates of chemical + + align:start position:0% +affect the rates of chemical + + + align:start position:0% +affect the rates of chemical +reactions and I will write some of these + + align:start position:0% +reactions and I will write some of these + + + align:start position:0% +reactions and I will write some of these +on the the board so what's one thing + + align:start position:0% +on the the board so what's one thing + + + align:start position:0% +on the the board so what's one thing +that you may have observed that will + + align:start position:0% +that you may have observed that will + + + align:start position:0% +that you may have observed that will +affect either speed up or slow down say + + align:start position:0% +affect either speed up or slow down say + + + align:start position:0% +affect either speed up or slow down say +a chemical reaction what's one thing you + + align:start position:0% +a chemical reaction what's one thing you + + + align:start position:0% +a chemical reaction what's one thing you +can think + + align:start position:0% +can think + + + align:start position:0% +can think +of + + align:start position:0% + + + + align:start position:0% + +temperature what's another thing you can + + align:start position:0% +temperature what's another thing you can + + + align:start position:0% +temperature what's another thing you can +think + + align:start position:0% + + + + align:start position:0% + +of Catal + + align:start position:0% + + + + align:start position:0% + +catalyst so right so changing the sort + + align:start position:0% +catalyst so right so changing the sort + + + align:start position:0% +catalyst so right so changing the sort +of in environment so it depends a little + + align:start position:0% +of in environment so it depends a little + + + align:start position:0% +of in environment so it depends a little +it could be it could be pressure it + + align:start position:0% +it could be it could be pressure it + + + align:start position:0% +it could be it could be pressure it +depends on um on what you're talking + + align:start position:0% +depends on um on what you're talking + + + align:start position:0% +depends on um on what you're talking +about what kind of uh nature of material + + align:start position:0% +about what kind of uh nature of material + + + align:start position:0% +about what kind of uh nature of material +you're talking about so possibly um + + align:start position:0% +you're talking about so possibly um + + + align:start position:0% +you're talking about so possibly um +pressure could have an effect and that + + align:start position:0% +pressure could have an effect and that + + + align:start position:0% +pressure could have an effect and that +brings us to the nature of the + + align:start position:0% + + + + align:start position:0% + +material whether it's gas or solid or + + align:start position:0% +material whether it's gas or solid or + + + align:start position:0% +material whether it's gas or solid or +other things um and that also comes to + + align:start position:0% +other things um and that also comes to + + + align:start position:0% +other things um and that also comes to +the other issue which is what is its + + align:start position:0% +the other issue which is what is its + + + align:start position:0% +the other issue which is what is its +mechanism oops sorry + + align:start position:0% +mechanism oops sorry + + + align:start position:0% +mechanism oops sorry +mechanism so does it have one step does + + align:start position:0% +mechanism so does it have one step does + + + align:start position:0% +mechanism so does it have one step does +it have many steps do the steps involve + + align:start position:0% +it have many steps do the steps involve + + + align:start position:0% +it have many steps do the steps involve +changes in Phase what's going on in the + + align:start position:0% +changes in Phase what's going on in the + + + align:start position:0% +changes in Phase what's going on in the +mechanism and so those are all some good + + align:start position:0% +mechanism and so those are all some good + + + align:start position:0% +mechanism and so those are all some good +things one other thing that I'll put on + + align:start position:0% +things one other thing that I'll put on + + + align:start position:0% +things one other thing that I'll put on +which also only applies um in some cases + + align:start position:0% +which also only applies um in some cases + + + align:start position:0% +which also only applies um in some cases +depending on the type of mechanism and + + align:start position:0% +depending on the type of mechanism and + + + align:start position:0% +depending on the type of mechanism and +type of reaction would be the + + align:start position:0% +type of reaction would be the + + + align:start position:0% +type of reaction would be the +concentration of the material which kind + + align:start position:0% +concentration of the material which kind + + + align:start position:0% +concentration of the material which kind +of also gets to this pressure idea um + + align:start position:0% +of also gets to this pressure idea um + + + align:start position:0% +of also gets to this pressure idea um +depending on what it is how much do you + + align:start position:0% +depending on what it is how much do you + + + align:start position:0% +depending on what it is how much do you +have in + + align:start position:0% +have in + + + align:start position:0% +have in +there all right so those are some of the + + align:start position:0% +there all right so those are some of the + + + align:start position:0% +there all right so those are some of the +things and we're going to talk about + + align:start position:0% +things and we're going to talk about + + + align:start position:0% +things and we're going to talk about +most of these in the next + + align:start position:0% +most of these in the next + + + align:start position:0% +most of these in the next +unit all right + + align:start position:0% + + + + align:start position:0% + +so let's now think about one example of + + align:start position:0% +so let's now think about one example of + + + align:start position:0% +so let's now think about one example of +a chemical reaction and this chemical + + align:start position:0% +a chemical reaction and this chemical + + + align:start position:0% +a chemical reaction and this chemical +reaction is called the oscillating clock + + align:start position:0% +reaction is called the oscillating clock + + + align:start position:0% +reaction is called the oscillating clock +and before we see the demo we're going + + align:start position:0% +and before we see the demo we're going + + + align:start position:0% +and before we see the demo we're going +to think about what's happening so this + + align:start position:0% +to think about what's happening so this + + + align:start position:0% +to think about what's happening so this +demo as with most chemical reactions + + align:start position:0% +demo as with most chemical reactions + + + align:start position:0% +demo as with most chemical reactions +involves thermodynamics chemical + + align:start position:0% +involves thermodynamics chemical + + + align:start position:0% +involves thermodynamics chemical +equilibrium kinetics it also has some + + align:start position:0% +equilibrium kinetics it also has some + + + align:start position:0% +equilibrium kinetics it also has some +acid base you have to have some acid in + + align:start position:0% +acid base you have to have some acid in + + + align:start position:0% +acid base you have to have some acid in +there to get it to go um it's also an + + align:start position:0% +there to get it to go um it's also an + + + align:start position:0% +there to get it to go um it's also an +oxidation reduction reaction and it has + + align:start position:0% +oxidation reduction reaction and it has + + + align:start position:0% +oxidation reduction reaction and it has +colors and we'll see that the colors + + align:start position:0% +colors and we'll see that the colors + + + align:start position:0% +colors and we'll see that the colors +change depending on what the oxidation + + align:start position:0% +change depending on what the oxidation + + + align:start position:0% +change depending on what the oxidation +state of the material is and also what + + align:start position:0% +state of the material is and also what + + + align:start position:0% +state of the material is and also what +its liganded state is so basically in + + align:start position:0% +its liganded state is so basically in + + + align:start position:0% +its liganded state is so basically in +one demo you get every unit that we've + + align:start position:0% +one demo you get every unit that we've + + + align:start position:0% +one demo you get every unit that we've +had in the second half of the course and + + align:start position:0% +had in the second half of the course and + + + align:start position:0% +had in the second half of the course and +that's kind of true about any chemical + + align:start position:0% +that's kind of true about any chemical + + + align:start position:0% +that's kind of true about any chemical +reaction every chem reaction if you're + + align:start position:0% +reaction every chem reaction if you're + + + align:start position:0% +reaction every chem reaction if you're +interested in it involves thinking about + + align:start position:0% +interested in it involves thinking about + + + align:start position:0% +interested in it involves thinking about +all of these things that we've been + + align:start position:0% +all of these things that we've been + + + align:start position:0% +all of these things that we've been +talking + + align:start position:0% +talking + + + align:start position:0% +talking +about all right so oscillating clock + + align:start position:0% +about all right so oscillating clock + + + align:start position:0% +about all right so oscillating clock +reaction um it's a fairly complicated + + align:start position:0% +reaction um it's a fairly complicated + + + align:start position:0% +reaction um it's a fairly complicated +reaction it has many steps and we're + + align:start position:0% +reaction it has many steps and we're + + + align:start position:0% +reaction it has many steps and we're +just going to break the overall reaction + + align:start position:0% +just going to break the overall reaction + + + align:start position:0% +just going to break the overall reaction +shown here down into two steps today as + + align:start position:0% +shown here down into two steps today as + + + align:start position:0% +shown here down into two steps today as +with many reaction mechanisms there are + + align:start position:0% +with many reaction mechanisms there are + + + align:start position:0% +with many reaction mechanisms there are +multiple steps but here is step one that + + align:start position:0% +multiple steps but here is step one that + + + align:start position:0% +multiple steps but here is step one that +we'll talk about and here is step two + + align:start position:0% +we'll talk about and here is step two + + + align:start position:0% +we'll talk about and here is step two +that we'll talk about + + align:start position:0% +that we'll talk about + + + align:start position:0% +that we'll talk about +and step one occurs when your I2 + + align:start position:0% +and step one occurs when your I2 + + + align:start position:0% +and step one occurs when your I2 +concentration is low I2 here is a + + align:start position:0% +concentration is low I2 here is a + + + align:start position:0% +concentration is low I2 here is a +product of the reaction and when it + + align:start position:0% +product of the reaction and when it + + + align:start position:0% +product of the reaction and when it +builds up too much then that reaction + + align:start position:0% +builds up too much then that reaction + + + align:start position:0% +builds up too much then that reaction +will stop and so in this reaction we + + align:start position:0% +will stop and so in this reaction we + + + align:start position:0% +will stop and so in this reaction we +have acidic conditions you'll see our H+ + + align:start position:0% +have acidic conditions you'll see our H+ + + + align:start position:0% +have acidic conditions you'll see our H+ +and under those acidic conditions we're + + align:start position:0% +and under those acidic conditions we're + + + align:start position:0% +and under those acidic conditions we're +going to change a clear solution so I + + align:start position:0% +going to change a clear solution so I + + + align:start position:0% +going to change a clear solution so I +iodide in its uh certain oxidation + + align:start position:0% +iodide in its uh certain oxidation + + + align:start position:0% +iodide in its uh certain oxidation +States is clear but when it goes to I2 + + align:start position:0% +States is clear but when it goes to I2 + + + align:start position:0% +States is clear but when it goes to I2 +it turns in amber color in the second + + align:start position:0% +it turns in amber color in the second + + + align:start position:0% +it turns in amber color in the second +reaction which will only occur when I2 + + align:start position:0% +reaction which will only occur when I2 + + + align:start position:0% +reaction which will only occur when I2 +is high so this will build up shutting + + align:start position:0% +is high so this will build up shutting + + + align:start position:0% +is high so this will build up shutting +off reaction a and starting reaction B + + align:start position:0% +off reaction a and starting reaction B + + + align:start position:0% +off reaction a and starting reaction B +in this reaction you have a complex + + align:start position:0% +in this reaction you have a complex + + + align:start position:0% +in this reaction you have a complex +being formed and that's going to change + + align:start position:0% +being formed and that's going to change + + + align:start position:0% +being formed and that's going to change +the color so we're going to go from + + align:start position:0% +the color so we're going to go from + + + align:start position:0% +the color so we're going to go from +Amber to a blue + + align:start position:0% +Amber to a blue + + + align:start position:0% +Amber to a blue +complex all right so before we see this + + align:start position:0% +complex all right so before we see this + + + align:start position:0% +complex all right so before we see this +happen and I should say that once you + + align:start position:0% +happen and I should say that once you + + + align:start position:0% +happen and I should say that once you +get over here you form the blue complex + + align:start position:0% +get over here you form the blue complex + + + align:start position:0% +get over here you form the blue complex +this will consume the I2 which will + + align:start position:0% +this will consume the I2 which will + + + align:start position:0% +this will consume the I2 which will +cause that to drop to be low again and + + align:start position:0% +cause that to drop to be low again and + + + align:start position:0% +cause that to drop to be low again and +then you're going to start reaction a + + align:start position:0% +then you're going to start reaction a + + + align:start position:0% +then you're going to start reaction a +again which then when it's gotten uh too + + align:start position:0% +again which then when it's gotten uh too + + + align:start position:0% +again which then when it's gotten uh too +when when your concentrations built up + + align:start position:0% +when when your concentrations built up + + + align:start position:0% +when when your concentrations built up +too much you'll start reaction B again + + align:start position:0% +too much you'll start reaction B again + + + align:start position:0% +too much you'll start reaction B again +and so reaction a then reaction B then + + align:start position:0% +and so reaction a then reaction B then + + + align:start position:0% +and so reaction a then reaction B then +reaction a reaction B um and you'll + + align:start position:0% +reaction a reaction B um and you'll + + + align:start position:0% +reaction a reaction B um and you'll +notice that the product of one of the + + align:start position:0% +notice that the product of one of the + + + align:start position:0% +notice that the product of one of the +reactions is a substrate here product + + align:start position:0% +reactions is a substrate here product + + + align:start position:0% +reactions is a substrate here product +here substrate here so this goes back + + align:start position:0% +here substrate here so this goes back + + + align:start position:0% +here substrate here so this goes back +and forth hence the name oscillating + + align:start position:0% +and forth hence the name oscillating + + + align:start position:0% +and forth hence the name oscillating +clock all right so before I show you + + align:start position:0% +clock all right so before I show you + + + align:start position:0% +clock all right so before I show you +something pretty I'm going to make you + + align:start position:0% +something pretty I'm going to make you + + + align:start position:0% +something pretty I'm going to make you +do work and think about the oxidation + + align:start position:0% +do work and think about the oxidation + + + align:start position:0% +do work and think about the oxidation +reduction reactions that are occurring + + align:start position:0% +reduction reactions that are occurring + + + align:start position:0% +reduction reactions that are occurring +that you're going to see that lead to + + align:start position:0% +that you're going to see that lead to + + + align:start position:0% +that you're going to see that lead to +these spectacular color changes all + + align:start position:0% +these spectacular color changes all + + + align:start position:0% +these spectacular color changes all +right + + align:start position:0% +right + + + align:start position:0% +right +so here we go clicker question + + align:start position:0% + + + + align:start position:0% + +all right let's just do 10 more + + align:start position:0% + + + + align:start position:0% + +seconds all right so somebody asked once + + align:start position:0% +seconds all right so somebody asked once + + + align:start position:0% +seconds all right so somebody asked once +like how will I know that it's a + + align:start position:0% +like how will I know that it's a + + + align:start position:0% +like how will I know that it's a +peroxide so I tried to help you out and + + align:start position:0% +peroxide so I tried to help you out and + + + align:start position:0% +peroxide so I tried to help you out and +said reaction with hydrogen peroxide see + + align:start position:0% +said reaction with hydrogen peroxide see + + + align:start position:0% +said reaction with hydrogen peroxide see +how many people some people definitely + + align:start position:0% +how many people some people definitely + + + align:start position:0% +how many people some people definitely +notice that all right so let's just take + + align:start position:0% +notice that all right so let's just take + + + align:start position:0% +notice that all right so let's just take +a look over here at what's going on and + + align:start position:0% +a look over here at what's going on and + + + align:start position:0% +a look over here at what's going on and +fill in our chart so here the oxidation + + align:start position:0% +fill in our chart so here the oxidation + + + align:start position:0% +fill in our chart so here the oxidation +state is + five so we have now this + + align:start position:0% +state is + five so we have now this + + + align:start position:0% +state is + five so we have now this +oxygen is its normal -2 so -2 * 3 - 6 + + align:start position:0% +oxygen is its normal -2 so -2 * 3 - 6 + + + align:start position:0% +oxygen is its normal -2 so -2 * 3 - 6 +equals the whole thing charge needs to + + align:start position:0% +equals the whole thing charge needs to + + + align:start position:0% +equals the whole thing charge needs to +equal minus one so we need plus five + + align:start position:0% +equal minus one so we need plus five + + + align:start position:0% +equal minus one so we need plus five +there and I2 is zero the next one I + + align:start position:0% +there and I2 is zero the next one I + + + align:start position:0% +there and I2 is zero the next one I +minus is being oxidized to I2 minus one + + align:start position:0% +minus is being oxidized to I2 minus one + + + align:start position:0% +minus is being oxidized to I2 minus one +to 0er the oxygen and hydrogen peroxide + + align:start position:0% +to 0er the oxygen and hydrogen peroxide + + + align:start position:0% +to 0er the oxygen and hydrogen peroxide +is being oxidized so it's minus um minus + + align:start position:0% +is being oxidized so it's minus um minus + + + align:start position:0% +is being oxidized so it's minus um minus +one here because we have plus two for H + + align:start position:0% +one here because we have plus two for H + + + align:start position:0% +one here because we have plus two for H +and two oxygen so that's minus one each + + align:start position:0% +and two oxygen so that's minus one each + + + align:start position:0% +and two oxygen so that's minus one each +to zero and then again minus one and + + align:start position:0% +to zero and then again minus one and + + + align:start position:0% +to zero and then again minus one and +oxygen and water is minus two so there's + + align:start position:0% +oxygen and water is minus two so there's + + + align:start position:0% +oxygen and water is minus two so there's +lots of oxidation reduction reactions + + align:start position:0% +lots of oxidation reduction reactions + + + align:start position:0% +lots of oxidation reduction reactions +going on and in fact this occurs in + + align:start position:0% +going on and in fact this occurs in + + + align:start position:0% +going on and in fact this occurs in +multiple different steps so there's even + + align:start position:0% +multiple different steps so there's even + + + align:start position:0% +multiple different steps so there's even +more different reactions going on that I + + align:start position:0% +more different reactions going on that I + + + align:start position:0% +more different reactions going on that I +didn't even show you all right so we + + align:start position:0% +didn't even show you all right so we + + + align:start position:0% +didn't even show you all right so we +have one more clicker question to answer + + align:start position:0% +have one more clicker question to answer + + + align:start position:0% +have one more clicker question to answer +before um we do the demo which is that + + align:start position:0% +before um we do the demo which is that + + + align:start position:0% +before um we do the demo which is that +if I told you you want to think about + + align:start position:0% +if I told you you want to think about + + + align:start position:0% +if I told you you want to think about +iodide you're using because it's + + align:start position:0% +iodide you're using because it's + + + align:start position:0% +iodide you're using because it's +changing color why are you using the + + align:start position:0% +changing color why are you using the + + + align:start position:0% +changing color why are you using the +hydrogen peroxide so tell me what uh is + + align:start position:0% +hydrogen peroxide so tell me what uh is + + + align:start position:0% +hydrogen peroxide so tell me what uh is +true about hydrogen peroxide using the + + align:start position:0% +true about hydrogen peroxide using the + + + align:start position:0% +true about hydrogen peroxide using the +information given + + align:start position:0% + + + + align:start position:0% + +all right 10 more seconds + + align:start position:0% + + + + align:start position:0% + +all + + align:start position:0% +all + + + align:start position:0% +all +right so if we look over here the large + + align:start position:0% +right so if we look over here the large + + + align:start position:0% +right so if we look over here the large +positive value and again that's a large + + align:start position:0% +positive value and again that's a large + + + align:start position:0% +positive value and again that's a large +positive value of the standard reduction + + align:start position:0% +positive value of the standard reduction + + + align:start position:0% +positive value of the standard reduction +potential um is a big big palue which + + align:start position:0% +potential um is a big big palue which + + + align:start position:0% +potential um is a big big palue which +makes it a good oxidizing agent the + + align:start position:0% +makes it a good oxidizing agent the + + + align:start position:0% +makes it a good oxidizing agent the +reduction is spontaneous so if you have + + align:start position:0% +reduction is spontaneous so if you have + + + align:start position:0% +reduction is spontaneous so if you have +a large positive e that's going to for + + align:start position:0% +a large positive e that's going to for + + + align:start position:0% +a large positive e that's going to for +the reaction written as a reduction that + + align:start position:0% +the reaction written as a reduction that + + + align:start position:0% +the reaction written as a reduction that +means that Delta G for that reduction is + + align:start position:0% +means that Delta G for that reduction is + + + align:start position:0% +means that Delta G for that reduction is +going to be NE negative which means it's + + align:start position:0% +going to be NE negative which means it's + + + align:start position:0% +going to be NE negative which means it's +spontaneous so things that like to be + + align:start position:0% +spontaneous so things that like to be + + + align:start position:0% +spontaneous so things that like to be +reduced are good oxidizing agents + + align:start position:0% +reduced are good oxidizing agents + + + align:start position:0% +reduced are good oxidizing agents +actually hydrogen peroxide is a really + + align:start position:0% +actually hydrogen peroxide is a really + + + align:start position:0% +actually hydrogen peroxide is a really +good oxidizing agent and that's why it's + + align:start position:0% +good oxidizing agent and that's why it's + + + align:start position:0% +good oxidizing agent and that's why it's +used in a lot of things all right so + + align:start position:0% +used in a lot of things all right so + + + align:start position:0% +used in a lot of things all right so +let's look at this demo now so again + + align:start position:0% +let's look at this demo now so again + + + align:start position:0% +let's look at this demo now so again +clear to Amber Amber to Blue and the + + align:start position:0% +clear to Amber Amber to Blue and the + + + align:start position:0% +clear to Amber Amber to Blue and the +reaction rate is also sensitive to + + align:start position:0% +reaction rate is also sensitive to + + + align:start position:0% +reaction rate is also sensitive to +temperature and you told me temperature + + align:start position:0% +temperature and you told me temperature + + + align:start position:0% +temperature and you told me temperature +does affect reaction rates and it does + + align:start position:0% +does affect reaction rates and it does + + + align:start position:0% +does affect reaction rates and it does +in this case all right let's see it Okay + + align:start position:0% +in this case all right let's see it Okay + + + align:start position:0% +in this case all right let's see it Okay +so we've got the hydrogen peroxide + + align:start position:0% +so we've got the hydrogen peroxide + + + align:start position:0% +so we've got the hydrogen peroxide +Eric's got that in hand he's going to + + align:start position:0% +Eric's got that in hand he's going to + + + align:start position:0% +Eric's got that in hand he's going to +take the that off before he actually + + align:start position:0% +take the that off before he actually + + + align:start position:0% +take the that off before he actually +unscrews it yay okay hydrogen peroxide + + align:start position:0% +unscrews it yay okay hydrogen peroxide + + + align:start position:0% +unscrews it yay okay hydrogen peroxide +as we said it's a good um uh it gets + + align:start position:0% +as we said it's a good um uh it gets + + + align:start position:0% +as we said it's a good um uh it gets +reduced really easily which is actually + + align:start position:0% +reduced really easily which is actually + + + align:start position:0% +reduced really easily which is actually +the reason why we kept it in a plastic + + align:start position:0% +the reason why we kept it in a plastic + + + align:start position:0% +the reason why we kept it in a plastic +bag because even the presence of oxygen + + align:start position:0% +bag because even the presence of oxygen + + + align:start position:0% +bag because even the presence of oxygen +can uh can cause it to be uh can cause + + align:start position:0% +can uh can cause it to be uh can cause + + + align:start position:0% +can uh can cause it to be uh can cause +it to react so he's going to add uh + + align:start position:0% +it to react so he's going to add uh + + + align:start position:0% +it to react so he's going to add uh +solution B that was solution a solution + + align:start position:0% +solution B that was solution a solution + + + align:start position:0% +solution B that was solution a solution +B uh contains the iodate which is going + + align:start position:0% +B uh contains the iodate which is going + + + align:start position:0% +B uh contains the iodate which is going +to provide the um the huh yeah got a St + + align:start position:0% +to provide the um the huh yeah got a St + + + align:start position:0% +to provide the um the huh yeah got a St +um it's going to provide the the uh + + align:start position:0% +um it's going to provide the the uh + + + align:start position:0% +um it's going to provide the the uh +iodine for the solution and as you can + + align:start position:0% +iodine for the solution and as you can + + + align:start position:0% +iodine for the solution and as you can +see it's turning kind of yellowish which + + align:start position:0% +see it's turning kind of yellowish which + + + align:start position:0% +see it's turning kind of yellowish which +is what we were expecting so now the + + align:start position:0% +is what we were expecting so now the + + + align:start position:0% +is what we were expecting so now the +iodate is starting to produce the iodine + + align:start position:0% +iodate is starting to produce the iodine + + + align:start position:0% +iodate is starting to produce the iodine +and when he adds solution D we can see + + align:start position:0% +and when he adds solution D we can see + + + align:start position:0% +and when he adds solution D we can see +it changing yay it + + align:start position:0% +it changing yay it + + + align:start position:0% +it changing yay it +works it's always a struggle whether + + align:start position:0% +works it's always a struggle whether + + + align:start position:0% +works it's always a struggle whether +these things will actually work but this + + align:start position:0% +these things will actually work but this + + + align:start position:0% +these things will actually work but this +one this one's usually works very nicely + + align:start position:0% +one this one's usually works very nicely + + + align:start position:0% +one this one's usually works very nicely +I'm going to turn this up a little bit + + align:start position:0% +I'm going to turn this up a little bit + + + align:start position:0% +I'm going to turn this up a little bit +more and it will actually continue to do + + align:start position:0% +more and it will actually continue to do + + + align:start position:0% +more and it will actually continue to do +this uh for for quite a while I think + + align:start position:0% +this uh for for quite a while I think + + + align:start position:0% +this uh for for quite a while I think +right so + + align:start position:0% +right so + + + align:start position:0% +right so +yeah yay awesome + + align:start position:0% +yeah yay awesome + + + align:start position:0% +yeah yay awesome +[Applause] + + align:start position:0% + + + + align:start position:0% + +awesome + + align:start position:0% +awesome + + + align:start position:0% +awesome +yeah so we can move this off to the side + + align:start position:0% +yeah so we can move this off to the side + + + align:start position:0% +yeah so we can move this off to the side +and now we're going to see the effect of + + align:start position:0% + + + + align:start position:0% + +temperature actually we move that in a + + align:start position:0% +temperature actually we move that in a + + + align:start position:0% +temperature actually we move that in a +second so uh as Kathy mentioned uh + + align:start position:0% +second so uh as Kathy mentioned uh + + + align:start position:0% +second so uh as Kathy mentioned uh +affecting temperature will affect the + + align:start position:0% +affecting temperature will affect the + + + align:start position:0% +affecting temperature will affect the +rates of reaction so this guy will + + align:start position:0% +rates of reaction so this guy will + + + align:start position:0% +rates of reaction so this guy will +continue to go and what we have here is + + align:start position:0% +continue to go and what we have here is + + + align:start position:0% +continue to go and what we have here is +we have all three solutions again except + + align:start position:0% +we have all three solutions again except + + + align:start position:0% +we have all three solutions again except +they've been uh they've been put in ice + + align:start position:0% +they've been uh they've been put in ice + + + align:start position:0% +they've been uh they've been put in ice +so we're going to see if we've kept this + + align:start position:0% +so we're going to see if we've kept this + + + align:start position:0% +so we're going to see if we've kept this +a little bit cold again you should have + + align:start position:0% +a little bit cold again you should have + + + align:start position:0% +a little bit cold again you should have +taken this thing + + align:start position:0% +taken this thing + + + align:start position:0% +taken this thing +off all right so that's the + + align:start position:0% +off all right so that's the + + + align:start position:0% +off all right so that's the +peroxide we've got + + align:start position:0% +peroxide we've got + + + align:start position:0% +peroxide we've got +solution B you got + + align:start position:0% +solution B you got + + + align:start position:0% +solution B you got +it + + align:start position:0% +it + + + align:start position:0% +it +okay and yeah I'll get the St in a + + align:start position:0% +okay and yeah I'll get the St in a + + + align:start position:0% +okay and yeah I'll get the St in a +second after B + + align:start position:0% + + + + align:start position:0% + +so as before you saw the temperature + + align:start position:0% +so as before you saw the temperature + + + align:start position:0% +so as before you saw the temperature +change kind of quickly um this time it's + + align:start position:0% +change kind of quickly um this time it's + + + align:start position:0% +change kind of quickly um this time it's +not really changing that much hold + + align:start position:0% + + + + align:start position:0% + +on so before you saw the temperature + + align:start position:0% +on so before you saw the temperature + + + align:start position:0% +on so before you saw the temperature +change pretty quickly this is probably + + align:start position:0% +change pretty quickly this is probably + + + align:start position:0% +change pretty quickly this is probably +going to take a while to actually change + + align:start position:0% +going to take a while to actually change + + + align:start position:0% +going to take a while to actually change +it might not change at all it's because + + align:start position:0% +it might not change at all it's because + + + align:start position:0% +it might not change at all it's because +the reaction was so cold that you won't + + align:start position:0% +the reaction was so cold that you won't + + + align:start position:0% +the reaction was so cold that you won't +have that second step and also I can't + + align:start position:0% +have that second step and also I can't + + + align:start position:0% +have that second step and also I can't +there we go so it happens really really + + align:start position:0% +there we go so it happens really really + + + align:start position:0% +there we go so it happens really really +slowly as you can tell whereas this one + + align:start position:0% +slowly as you can tell whereas this one + + + align:start position:0% +slowly as you can tell whereas this one +happened very very quickly so yay yeah + + align:start position:0% +happened very very quickly so yay yeah + + + align:start position:0% +happened very very quickly so yay yeah +so example of many things so we had + + align:start position:0% +so example of many things so we had + + + align:start position:0% +so example of many things so we had +chemical equilibrium we had + + align:start position:0% +chemical equilibrium we had + + + align:start position:0% +chemical equilibrium we had +thermodynamics talking about which + + align:start position:0% +thermodynamics talking about which + + + align:start position:0% +thermodynamics talking about which +reactions were spontaneous so + + align:start position:0% +reactions were spontaneous so + + + align:start position:0% +reactions were spontaneous so +spontaneous until the making the Amber + + align:start position:0% +spontaneous until the making the Amber + + + align:start position:0% +spontaneous until the making the Amber +and then when it's made too much of the + + align:start position:0% +and then when it's made too much of the + + + align:start position:0% +and then when it's made too much of the +the iodide than the I2 then we see the + + align:start position:0% +the iodide than the I2 then we see the + + + align:start position:0% +the iodide than the I2 then we see the +next reaction going until we now have + + align:start position:0% +next reaction going until we now have + + + align:start position:0% +next reaction going until we now have +too little and then we switch back and + + align:start position:0% +too little and then we switch back and + + + align:start position:0% +too little and then we switch back and +forth and yeah this I think very clearly + + align:start position:0% +forth and yeah this I think very clearly + + + align:start position:0% +forth and yeah this I think very clearly +demonstrates that the uh the temperature + + align:start position:0% +demonstrates that the uh the temperature + + + align:start position:0% +demonstrates that the uh the temperature +is very different has a very different + + align:start position:0% +is very different has a very different + + + align:start position:0% +is very different has a very different +effect it's a much much slower + + align:start position:0% +effect it's a much much slower + + + align:start position:0% +effect it's a much much slower +reaction all right thank you we can + + align:start position:0% +reaction all right thank you we can + + + align:start position:0% +reaction all right thank you we can +leave them up do you want to just leave + + align:start position:0% +leave them up do you want to just leave + + + align:start position:0% +leave them up do you want to just leave +them up here I'm leave this yeah okay + + align:start position:0% +them up here I'm leave this yeah okay + + + align:start position:0% +them up here I'm leave this yeah okay +we'll leave the fast one up there it + + align:start position:0% +we'll leave the fast one up there it + + + align:start position:0% +we'll leave the fast one up there it +will eventually stop so uh it's good + + align:start position:0% +will eventually stop so uh it's good + + + align:start position:0% +will eventually stop so uh it's good +probably I don't know maybe F five + + align:start position:0% +probably I don't know maybe F five + + + align:start position:0% +probably I don't know maybe F five +minutes or more or a little longer and + + align:start position:0% +minutes or more or a little longer and + + + align:start position:0% +minutes or more or a little longer and +then eventually it just kind of stays + + align:start position:0% +then eventually it just kind of stays + + + align:start position:0% +then eventually it just kind of stays +this uh uh more dark brown maybe it's + + align:start position:0% +this uh uh more dark brown maybe it's + + + align:start position:0% +this uh uh more dark brown maybe it's +already happened we'll see if it + + align:start position:0% +already happened we'll see if it + + + align:start position:0% +already happened we'll see if it +switches + + align:start position:0% + + + + align:start position:0% + +again all right so let's talk about + + align:start position:0% +again all right so let's talk about + + + align:start position:0% +again all right so let's talk about +measuring reaction rates then because we + + align:start position:0% +measuring reaction rates then because we + + + align:start position:0% +measuring reaction rates then because we +just saw this reaction going in another + + align:start position:0% +just saw this reaction going in another + + + align:start position:0% +just saw this reaction going in another +reaction rate we saw the effect of + + align:start position:0% +reaction rate we saw the effect of + + + align:start position:0% +reaction rate we saw the effect of +temperature um and let's think about how + + align:start position:0% +temperature um and let's think about how + + + align:start position:0% +temperature um and let's think about how +we would actually go about measuring + + align:start position:0% +we would actually go about measuring + + + align:start position:0% +we would actually go about measuring +some of these so we can think about + + align:start position:0% +some of these so we can think about + + + align:start position:0% +some of these so we can think about +measuring two different kinds of rates + + align:start position:0% +measuring two different kinds of rates + + + align:start position:0% +measuring two different kinds of rates +an average rate and an instantaneous + + align:start position:0% +an average rate and an instantaneous + + + align:start position:0% +an average rate and an instantaneous +rate and so first let's talk about + + align:start position:0% +rate and so first let's talk about + + + align:start position:0% +rate and so first let's talk about +measuring average rate and to do that I + + align:start position:0% +measuring average rate and to do that I + + + align:start position:0% +measuring average rate and to do that I +should switch back over here okay so + + align:start position:0% +should switch back over here okay so + + + align:start position:0% +should switch back over here okay so +let's consider a different reaction now + + align:start position:0% +let's consider a different reaction now + + + align:start position:0% +let's consider a different reaction now +one that's a little less complicated and + + align:start position:0% +one that's a little less complicated and + + + align:start position:0% +one that's a little less complicated and +kind of made up but it's a good example + + align:start position:0% +kind of made up but it's a good example + + + align:start position:0% +kind of made up but it's a good example +um NO2 plus Co goes to no plus + + align:start position:0% +um NO2 plus Co goes to no plus + + + align:start position:0% +um NO2 plus Co goes to no plus +CO2 and so if you're measuring a rate + + align:start position:0% +CO2 and so if you're measuring a rate + + + align:start position:0% +CO2 and so if you're measuring a rate +you could think about measuring the + + align:start position:0% +you could think about measuring the + + + align:start position:0% +you could think about measuring the +decrease in either of the reactants or + + align:start position:0% +decrease in either of the reactants or + + + align:start position:0% +decrease in either of the reactants or +the increase in concentration of either + + align:start position:0% +the increase in concentration of either + + + align:start position:0% +the increase in concentration of either +of the products so in this case let's + + align:start position:0% +of the products so in this case let's + + + align:start position:0% +of the products so in this case let's +consider um that we're measuring the + + align:start position:0% +consider um that we're measuring the + + + align:start position:0% +consider um that we're measuring the +change in n + + align:start position:0% +change in n + + + align:start position:0% +change in n +and usually people pick the thing to + + align:start position:0% +and usually people pick the thing to + + + align:start position:0% +and usually people pick the thing to +measure based on what's easiest to + + align:start position:0% +measure based on what's easiest to + + + align:start position:0% +measure based on what's easiest to +measure what kind of handle you are does + + align:start position:0% +measure what kind of handle you are does + + + align:start position:0% +measure what kind of handle you are does +it have a spectroscopic signal or + + align:start position:0% +it have a spectroscopic signal or + + + align:start position:0% +it have a spectroscopic signal or +something else that you can easily + + align:start position:0% +something else that you can easily + + + align:start position:0% +something else that you can easily +measure so here we have concentration + + align:start position:0% +measure so here we have concentration + + + align:start position:0% +measure so here we have concentration +versus time and so we should see none in + + align:start position:0% +versus time and so we should see none in + + + align:start position:0% +versus time and so we should see none in +the beginning and then we should see it + + align:start position:0% +the beginning and then we should see it + + + align:start position:0% +the beginning and then we should see it +increase and then level off and we can + + align:start position:0% +increase and then level off and we can + + + align:start position:0% +increase and then level off and we can +calculate an average rate which is just + + align:start position:0% +calculate an average rate which is just + + + align:start position:0% +calculate an average rate which is just +going to be the change in concentration + + align:start position:0% +going to be the change in concentration + + + align:start position:0% +going to be the change in concentration +over the change in time we can also + + align:start position:0% +over the change in time we can also + + + align:start position:0% +over the change in time we can also +Express the average rate as Delta the + + align:start position:0% +Express the average rate as Delta the + + + align:start position:0% +Express the average rate as Delta the +concentration of no over delta T the + + align:start position:0% +concentration of no over delta T the + + + align:start position:0% +concentration of no over delta T the +change in + + align:start position:0% +change in + + + align:start position:0% +change in +time and we can calculate what that + + align:start position:0% +time and we can calculate what that + + + align:start position:0% +time and we can calculate what that +would be we can pick an interval say + + align:start position:0% +would be we can pick an interval say + + + align:start position:0% +would be we can pick an interval say +from 50 to 150 we can measure some + + align:start position:0% +from 50 to 150 we can measure some + + + align:start position:0% +from 50 to 150 we can measure some +concentrations there and then calculate + + align:start position:0% +concentrations there and then calculate + + + align:start position:0% +concentrations there and then calculate +the average rate the change in + + align:start position:0% +the average rate the change in + + + align:start position:0% +the average rate the change in +concentration from the time 150 to the + + align:start position:0% +concentration from the time 150 to the + + + align:start position:0% +concentration from the time 150 to the +time 50 concentration over that time + + align:start position:0% +time 50 concentration over that time + + + align:start position:0% +time 50 concentration over that time +interval and it will give us an answer + + align:start position:0% +interval and it will give us an answer + + + align:start position:0% +interval and it will give us an answer +in this case 1.3 * 10-4 molar per second + + align:start position:0% +in this case 1.3 * 10-4 molar per second + + + align:start position:0% +in this case 1.3 * 10-4 molar per second +all right well that could be useful to + + align:start position:0% +all right well that could be useful to + + + align:start position:0% +all right well that could be useful to +know but it really depends on the + + align:start position:0% +know but it really depends on the + + + align:start position:0% +know but it really depends on the +average rate depends on the time + + align:start position:0% +average rate depends on the time + + + align:start position:0% +average rate depends on the time +interval I picked if I picked a + + align:start position:0% +interval I picked if I picked a + + + align:start position:0% +interval I picked if I picked a +different time interval I might have + + align:start position:0% +different time interval I might have + + + align:start position:0% +different time interval I might have +gotten a different rate so instead of + + align:start position:0% +gotten a different rate so instead of + + + align:start position:0% +gotten a different rate so instead of +calculating average rate a lot of people + + align:start position:0% +calculating average rate a lot of people + + + align:start position:0% +calculating average rate a lot of people +want to Cal calculate instantaneous rate + + align:start position:0% +want to Cal calculate instantaneous rate + + + align:start position:0% +want to Cal calculate instantaneous rate +where you're asking what is the rate at + + align:start position:0% +where you're asking what is the rate at + + + align:start position:0% +where you're asking what is the rate at +a particular time point so now let's + + align:start position:0% +a particular time point so now let's + + + align:start position:0% +a particular time point so now let's +talk about instantaneous rate we'll have + + align:start position:0% +talk about instantaneous rate we'll have + + + align:start position:0% +talk about instantaneous rate we'll have +the same uh equation up there now + + align:start position:0% +the same uh equation up there now + + + align:start position:0% +the same uh equation up there now +instantaneous rate is uh defined as the + + align:start position:0% +instantaneous rate is uh defined as the + + + align:start position:0% +instantaneous rate is uh defined as the +rate where you have a limit of delta T + + align:start position:0% +rate where you have a limit of delta T + + + align:start position:0% +rate where you have a limit of delta T +the change in time going to zero you're + + align:start position:0% +the change in time going to zero you're + + + align:start position:0% +the change in time going to zero you're +comparing concentrations at time T and + + align:start position:0% +comparing concentrations at time T and + + + align:start position:0% +comparing concentrations at time T and +time t plus the interval + + align:start position:0% +time t plus the interval + + + align:start position:0% +time t plus the interval +DT over this time change again as you + + align:start position:0% +DT over this time change again as you + + + align:start position:0% +DT over this time change again as you +approach um zero you can also Express + + align:start position:0% +approach um zero you can also Express + + + align:start position:0% +approach um zero you can also Express +this as + + align:start position:0% +this as + + + align:start position:0% +this as +D change in concentration of n + + align:start position:0% +D change in concentration of n + + + align:start position:0% +D change in concentration of n +DT and so as that change in time + + align:start position:0% +DT and so as that change in time + + + align:start position:0% +DT and so as that change in time +approaches + + align:start position:0% +approaches + + + align:start position:0% +approaches +zero then the rate becomes the slope of + + align:start position:0% +zero then the rate becomes the slope of + + + align:start position:0% +zero then the rate becomes the slope of +a of the line tangent to the + + align:start position:0% +a of the line tangent to the + + + align:start position:0% +a of the line tangent to the +curve at time T so if we wanted to to + + align:start position:0% +curve at time T so if we wanted to to + + + align:start position:0% +curve at time T so if we wanted to to +say find the instantaneous rate at 150 + + align:start position:0% +say find the instantaneous rate at 150 + + + align:start position:0% +say find the instantaneous rate at 150 +here's 150 we can draw a line tangent to + + align:start position:0% +here's 150 we can draw a line tangent to + + + align:start position:0% +here's 150 we can draw a line tangent to +the curve at + + align:start position:0% +the curve at + + + align:start position:0% +the curve at +that time so this would be the point at + + align:start position:0% +that time so this would be the point at + + + align:start position:0% +that time so this would be the point at +150 and then we can calculate the slope + + align:start position:0% +150 and then we can calculate the slope + + + align:start position:0% +150 and then we can calculate the slope +to tell us the instantaneous + + align:start position:0% +to tell us the instantaneous + + + align:start position:0% +to tell us the instantaneous +rate so let's do that we will calculate + + align:start position:0% +rate so let's do that we will calculate + + + align:start position:0% +rate so let's do that we will calculate +the slope we have to look at what the + + align:start position:0% +the slope we have to look at what the + + + align:start position:0% +the slope we have to look at what the +concentrations are what the times are + + align:start position:0% +concentrations are what the times are + + + align:start position:0% +concentrations are what the times are +and then the instantaneous rate at + + align:start position:0% +and then the instantaneous rate at + + + align:start position:0% +and then the instantaneous rate at +150 would be the slope of the line this + + align:start position:0% +150 would be the slope of the line this + + + align:start position:0% +150 would be the slope of the line this +change in concentration over that time + + align:start position:0% +change in concentration over that time + + + align:start position:0% +change in concentration over that time +interval and and to the correct + + align:start position:0% +interval and and to the correct + + + align:start position:0% +interval and and to the correct +significant figures there should be an + + align:start position:0% +significant figures there should be an + + + align:start position:0% +significant figures there should be an +extra zero in there um + + align:start position:0% +extra zero in there um + + + align:start position:0% +extra zero in there um +7.70 * 10- 5 molar per second so that + + align:start position:0% +7.70 * 10- 5 molar per second so that + + + align:start position:0% +7.70 * 10- 5 molar per second so that +would be the instantaneous rate again + + align:start position:0% +would be the instantaneous rate again + + + align:start position:0% +would be the instantaneous rate again +the slope of the line tangent to the + + align:start position:0% +the slope of the line tangent to the + + + align:start position:0% +the slope of the line tangent to the +curve at time 150 so you could ask what + + align:start position:0% +curve at time 150 so you could ask what + + + align:start position:0% +curve at time 150 so you could ask what +is the instantaneous rate at 100 seconds + + align:start position:0% +is the instantaneous rate at 100 seconds + + + align:start position:0% +is the instantaneous rate at 100 seconds +or 200 seconds um and get that + + align:start position:0% +or 200 seconds um and get that + + + align:start position:0% +or 200 seconds um and get that +instantaneous rate people are often + + align:start position:0% +instantaneous rate people are often + + + align:start position:0% +instantaneous rate people are often +talking about initial rate and by + + align:start position:0% +talking about initial rate and by + + + align:start position:0% +talking about initial rate and by +initial rate they mean the instantaneous + + align:start position:0% +initial rate they mean the instantaneous + + + align:start position:0% +initial rate they mean the instantaneous +rate at time equals zero so again we + + align:start position:0% +rate at time equals zero so again we + + + align:start position:0% +rate at time equals zero so again we +have two different rates we have average + + align:start position:0% +have two different rates we have average + + + align:start position:0% +have two different rates we have average +rate and instantaneous rate so now let's + + align:start position:0% +rate and instantaneous rate so now let's + + + align:start position:0% +rate and instantaneous rate so now let's +think about rate expressions and then + + align:start position:0% +think about rate expressions and then + + + align:start position:0% +think about rate expressions and then +rate laws all right so keeping with that + + align:start position:0% +rate laws all right so keeping with that + + + align:start position:0% +rate laws all right so keeping with that +same um + + align:start position:0% +same um + + + align:start position:0% +same um +reaction again we could monitor no + + align:start position:0% +reaction again we could monitor no + + + align:start position:0% +reaction again we could monitor no +forming or CO2 forming or we could + + align:start position:0% +forming or CO2 forming or we could + + + align:start position:0% +forming or CO2 forming or we could +monitor either of our reactants + + align:start position:0% +monitor either of our reactants + + + align:start position:0% +monitor either of our reactants +disappearing and if we assume that + + align:start position:0% +disappearing and if we assume that + + + align:start position:0% +disappearing and if we assume that +there's no intermediates or or very slow + + align:start position:0% +there's no intermediates or or very slow + + + align:start position:0% +there's no intermediates or or very slow +steps then we could say that the rate of + + align:start position:0% +steps then we could say that the rate of + + + align:start position:0% +steps then we could say that the rate of +the reaction should be equal to The + + align:start position:0% +the reaction should be equal to The + + + align:start position:0% +the reaction should be equal to The +Disappearance of the concentration of + + align:start position:0% +Disappearance of the concentration of + + + align:start position:0% +Disappearance of the concentration of +NO2 or decrease in NO2 one of our + + align:start position:0% +NO2 or decrease in NO2 one of our + + + align:start position:0% +NO2 or decrease in NO2 one of our +reactants over time it should also be + + align:start position:0% +reactants over time it should also be + + + align:start position:0% +reactants over time it should also be +equal to The Disappearance of Co our + + align:start position:0% +equal to The Disappearance of Co our + + + align:start position:0% +equal to The Disappearance of Co our +other reactant over time and also equal + + align:start position:0% +other reactant over time and also equal + + + align:start position:0% +other reactant over time and also equal +to the appearance of n o with time and + + align:start position:0% +to the appearance of n o with time and + + + align:start position:0% +to the appearance of n o with time and +also equal to the appearance of CO2 with + + align:start position:0% +also equal to the appearance of CO2 with + + + align:start position:0% +also equal to the appearance of CO2 with +time and again for these all to be equal + + align:start position:0% +time and again for these all to be equal + + + align:start position:0% +time and again for these all to be equal +to each other we are assuming here there + + align:start position:0% +to each other we are assuming here there + + + align:start position:0% +to each other we are assuming here there +are no intermediates being formed and or + + align:start position:0% +are no intermediates being formed and or + + + align:start position:0% +are no intermediates being formed and or +that if we are forming them then they're + + align:start position:0% +that if we are forming them then they're + + + align:start position:0% +that if we are forming them then they're +independent of time in other words if + + align:start position:0% +independent of time in other words if + + + align:start position:0% +independent of time in other words if +say there was a large slow step + + align:start position:0% +say there was a large slow step + + + align:start position:0% +say there was a large slow step +somewhere in here we might see all the + + align:start position:0% +somewhere in here we might see all the + + + align:start position:0% +somewhere in here we might see all the +reactants + + align:start position:0% +reactants + + + align:start position:0% +reactants +disappear but there'd be a lag before + + align:start position:0% +disappear but there'd be a lag before + + + align:start position:0% +disappear but there'd be a lag before +the products would appear because more + + align:start position:0% +the products would appear because more + + + align:start position:0% +the products would appear because more +steps and things are going on so these + + align:start position:0% +steps and things are going on so these + + + align:start position:0% +steps and things are going on so these +are all equal to each other if you have + + align:start position:0% +are all equal to each other if you have + + + align:start position:0% +are all equal to each other if you have +no intermediates or the intermediates + + align:start position:0% +no intermediates or the intermediates + + + align:start position:0% +no intermediates or the intermediates +are not affecting the overall + + align:start position:0% +are not affecting the overall + + + align:start position:0% +are not affecting the overall +rate so we could think about this for a + + align:start position:0% +rate so we could think about this for a + + + align:start position:0% +rate so we could think about this for a +generic equation so if we consider a + + align:start position:0% +generic equation so if we consider a + + + align:start position:0% +generic equation so if we consider a +plus b going to C plus d when we're + + align:start position:0% +plus b going to C plus d when we're + + + align:start position:0% +plus b going to C plus d when we're +talking about the rates of disappearance + + align:start position:0% +talking about the rates of disappearance + + + align:start position:0% +talking about the rates of disappearance +or appearance we have to remember the + + align:start position:0% +or appearance we have to remember the + + + align:start position:0% +or appearance we have to remember the +stochiometry of the reaction so if we + + align:start position:0% +stochiometry of the reaction so if we + + + align:start position:0% +stochiometry of the reaction so if we +have a stochiometry of little a then we + + align:start position:0% +have a stochiometry of little a then we + + + align:start position:0% +have a stochiometry of little a then we +would say minus1 over little a a d a DT + + align:start position:0% +would say minus1 over little a a d a DT + + + align:start position:0% +would say minus1 over little a a d a DT +stochiometry of little B for reactant B + + align:start position:0% +stochiometry of little B for reactant B + + + align:start position:0% +stochiometry of little B for reactant B +minus 1 over b b DB + + align:start position:0% +minus 1 over b b DB + + + align:start position:0% +minus 1 over b b DB +DT then formation of products 1 over C + + align:start position:0% +DT then formation of products 1 over C + + + align:start position:0% +DT then formation of products 1 over C +DC DT and our other product one over + + align:start position:0% +DC DT and our other product one over + + + align:start position:0% +DC DT and our other product one over +little d d d DT I got through it okay so + + align:start position:0% +little d d d DT I got through it okay so + + + align:start position:0% +little d d d DT I got through it okay so +let's look at an example reaction and + + align:start position:0% +let's look at an example reaction and + + + align:start position:0% +let's look at an example reaction and +why don't you tell me what the is equal + + align:start position:0% + + + + align:start position:0% + +to why don't you look at the results + + align:start position:0% +to why don't you look at the results + + + align:start position:0% +to why don't you look at the results +make a + + align:start position:0% + + + + align:start position:0% + +decision okay 10 seconds + + align:start position:0% + + + + align:start position:0% + +all + + align:start position:0% +all + + + align:start position:0% +all +right still haven't gotten much into the + + align:start position:0% +right still haven't gotten much into the + + + align:start position:0% +right still haven't gotten much into the +90s but still I'm happy all right so + + align:start position:0% +90s but still I'm happy all right so + + + align:start position:0% +90s but still I'm happy all right so +here again we're talking about The + + align:start position:0% +here again we're talking about The + + + align:start position:0% +here again we're talking about The +Disappearance of our um reactant so it + + align:start position:0% +Disappearance of our um reactant so it + + + align:start position:0% +Disappearance of our um reactant so it +would be minus one2 and the uh formation + + align:start position:0% +would be minus one2 and the uh formation + + + align:start position:0% +would be minus one2 and the uh formation +of one one of our products and the + + align:start position:0% +of one one of our products and the + + + align:start position:0% +of one one of our products and the +formation of the other product as well + + align:start position:0% +formation of the other product as well + + + align:start position:0% +formation of the other product as well +all right so don't forget about the sto + + align:start position:0% +all right so don't forget about the sto + + + align:start position:0% +all right so don't forget about the sto +geometry of the re action so these are + + align:start position:0% +geometry of the re action so these are + + + align:start position:0% +geometry of the re action so these are +called rate + + align:start position:0% +called rate + + + align:start position:0% +called rate +expressions and you don't want to get + + align:start position:0% +expressions and you don't want to get + + + align:start position:0% +expressions and you don't want to get +that confused with rate laws so a + + align:start position:0% +that confused with rate laws so a + + + align:start position:0% +that confused with rate laws so a +problem might ask write the rate + + align:start position:0% +problem might ask write the rate + + + align:start position:0% +problem might ask write the rate +expression this is what it's looking for + + align:start position:0% +expression this is what it's looking for + + + align:start position:0% +expression this is what it's looking for +if it says write the rate law it's going + + align:start position:0% +if it says write the rate law it's going + + + align:start position:0% +if it says write the rate law it's going +to be looking for the following thing so + + align:start position:0% +to be looking for the following thing so + + + align:start position:0% +to be looking for the following thing so +a rate law is a relationship between + + align:start position:0% +a rate law is a relationship between + + + align:start position:0% +a rate law is a relationship between +rate and + + align:start position:0% +rate and + + + align:start position:0% +rate and +concentration and they are related by a + + align:start position:0% +concentration and they are related by a + + + align:start position:0% +concentration and they are related by a +proportionality constant little K which + + align:start position:0% +proportionality constant little K which + + + align:start position:0% +proportionality constant little K which +is called the rate constant so big K is + + align:start position:0% +is called the rate constant so big K is + + + align:start position:0% +is called the rate constant so big K is +what equilibrium constant little K is a + + align:start position:0% +what equilibrium constant little K is a + + + align:start position:0% +what equilibrium constant little K is a +rate constant all right so let's look at + + align:start position:0% +rate constant all right so let's look at + + + align:start position:0% +rate constant all right so let's look at +a + + align:start position:0% +a + + + align:start position:0% +a +reaction and so reaction of a plus b c + + align:start position:0% +reaction and so reaction of a plus b c + + + align:start position:0% +reaction and so reaction of a plus b c +going to C plus d the rate law could be + + align:start position:0% +going to C plus d the rate law could be + + + align:start position:0% +going to C plus d the rate law could be +expressed rate equals rate constant K + + align:start position:0% +expressed rate equals rate constant K + + + align:start position:0% +expressed rate equals rate constant K +times the concentration of a to the m + + align:start position:0% +times the concentration of a to the m + + + align:start position:0% +times the concentration of a to the m +and B to the N where M and N are the + + align:start position:0% +and B to the N where M and N are the + + + align:start position:0% +and B to the N where M and N are the +order of the reaction in a and b + + align:start position:0% +order of the reaction in a and b + + + align:start position:0% +order of the reaction in a and b +respectively and K again is our rate + + align:start position:0% +respectively and K again is our rate + + + align:start position:0% +respectively and K again is our rate +constant all right so let's look at what + + align:start position:0% +constant all right so let's look at what + + + align:start position:0% +constant all right so let's look at what +I call the truth about rate + + align:start position:0% + + + + align:start position:0% + +laws so the first thing you cannot just + + align:start position:0% +laws so the first thing you cannot just + + + align:start position:0% +laws so the first thing you cannot just +look at the stochiometry of the equation + + align:start position:0% +look at the stochiometry of the equation + + + align:start position:0% +look at the stochiometry of the equation +and say oh it's going to have this M for + + align:start position:0% +and say oh it's going to have this M for + + + align:start position:0% +and say oh it's going to have this M for +a based on its Doom omry unless it's + + align:start position:0% +a based on its Doom omry unless it's + + + align:start position:0% +a based on its Doom omry unless it's +what's called an elementary reaction and + + align:start position:0% +what's called an elementary reaction and + + + align:start position:0% +what's called an elementary reaction and +we're going to get to that on Wednesday + + align:start position:0% +we're going to get to that on Wednesday + + + align:start position:0% +we're going to get to that on Wednesday +after Thanksgiving make sure you come + + align:start position:0% +after Thanksgiving make sure you come + + + align:start position:0% +after Thanksgiving make sure you come +Wednesday after Thanksgiving that's the + + align:start position:0% +Wednesday after Thanksgiving that's the + + + align:start position:0% +Wednesday after Thanksgiving that's the +lecture on mechanism that's a really + + align:start position:0% +lecture on mechanism that's a really + + + align:start position:0% +lecture on mechanism that's a really +important lecture in kinetics so we'll + + align:start position:0% +important lecture in kinetics so we'll + + + align:start position:0% +important lecture in kinetics so we'll +learn about elementary reactions so you + + align:start position:0% +learn about elementary reactions so you + + + align:start position:0% +learn about elementary reactions so you +can't just look at the stochiometry and + + align:start position:0% +can't just look at the stochiometry and + + + align:start position:0% +can't just look at the stochiometry and +write the rate law you need + + align:start position:0% +write the rate law you need + + + align:start position:0% +write the rate law you need +experiment so the rate law is not just + + align:start position:0% +experiment so the rate law is not just + + + align:start position:0% +experiment so the rate law is not just +limited to reactants although largely um + + align:start position:0% +limited to reactants although largely um + + + align:start position:0% +limited to reactants although largely um +it's true that the rate laws will just + + align:start position:0% +it's true that the rate laws will just + + + align:start position:0% +it's true that the rate laws will just +have reactants it can also have a + + align:start position:0% +have reactants it can also have a + + + align:start position:0% +have reactants it can also have a +product term like C could appear in the + + align:start position:0% +product term like C could appear in the + + + align:start position:0% +product term like C could appear in the +rate law how would you know this well it + + align:start position:0% +rate law how would you know this well it + + + align:start position:0% +rate law how would you know this well it +would be experiment would tell you + + align:start position:0% +would be experiment would tell you + + + align:start position:0% +would be experiment would tell you +whether this was true or + + align:start position:0% +whether this was true or + + + align:start position:0% +whether this was true or +not so for this rate law we saw this + + align:start position:0% +not so for this rate law we saw this + + + align:start position:0% +not so for this rate law we saw this +already um the order of the reaction in + + align:start position:0% +already um the order of the reaction in + + + align:start position:0% +already um the order of the reaction in +a is + + align:start position:0% +a is + + + align:start position:0% +a is +um is M and the Order of the reaction in + + align:start position:0% +um is M and the Order of the reaction in + + + align:start position:0% +um is M and the Order of the reaction in +B is n and M and N can be integers they + + align:start position:0% +B is n and M and N can be integers they + + + align:start position:0% +B is n and M and N can be integers they +can be frac fractions or they can be + + align:start position:0% +can be frac fractions or they can be + + + align:start position:0% +can be frac fractions or they can be +positive and they can be + + align:start position:0% +positive and they can be + + + align:start position:0% +positive and they can be +negative so now we're going to think + + align:start position:0% +negative so now we're going to think + + + align:start position:0% +negative so now we're going to think +about all these different um orders of + + align:start position:0% +about all these different um orders of + + + align:start position:0% +about all these different um orders of +reaction and think about what and we'll + + align:start position:0% +reaction and think about what and we'll + + + align:start position:0% +reaction and think about what and we'll +do it just for a what m is equal to so + + align:start position:0% +do it just for a what m is equal to so + + + align:start position:0% +do it just for a what m is equal to so +we're going to fill in this table here + + align:start position:0% +we're going to fill in this table here + + + align:start position:0% +we're going to fill in this table here +and some of these things are in your + + align:start position:0% +and some of these things are in your + + + align:start position:0% +and some of these things are in your +notes some of them you need to fill in + + align:start position:0% +notes some of them you need to fill in + + + align:start position:0% +notes some of them you need to fill in +so we're going to start with m equals + + align:start position:0% +so we're going to start with m equals + + + align:start position:0% +so we're going to start with m equals +1 and this is called a firstorder + + align:start position:0% +1 and this is called a firstorder + + + align:start position:0% +1 and this is called a firstorder +reaction + + align:start position:0% +reaction + + + align:start position:0% +reaction +the rate law for this the rate would + + align:start position:0% +the rate law for this the rate would + + + align:start position:0% +the rate law for this the rate would +equal the rate constant times the + + align:start position:0% +equal the rate constant times the + + + align:start position:0% +equal the rate constant times the +concentration of a and now let's just + + align:start position:0% +concentration of a and now let's just + + + align:start position:0% +concentration of a and now let's just +think if this is a first order reaction + + align:start position:0% +think if this is a first order reaction + + + align:start position:0% +think if this is a first order reaction +that just depends on a if you double the + + align:start position:0% +that just depends on a if you double the + + + align:start position:0% +that just depends on a if you double the +concentration of a what do you expect + + align:start position:0% +concentration of a what do you expect + + + align:start position:0% +concentration of a what do you expect +will happen to the + + align:start position:0% + + + + align:start position:0% + +rate + + align:start position:0% +rate + + + align:start position:0% +rate +what it will double right so in first + + align:start position:0% +what it will double right so in first + + + align:start position:0% +what it will double right so in first +order reaction you double the + + align:start position:0% +order reaction you double the + + + align:start position:0% +order reaction you double the +concentration of something and the rate + + align:start position:0% +concentration of something and the rate + + + align:start position:0% +concentration of something and the rate +will double and this is how you figure + + align:start position:0% +will double and this is how you figure + + + align:start position:0% +will double and this is how you figure +out what the order of the reaction is + + align:start position:0% +out what the order of the reaction is + + + align:start position:0% +out what the order of the reaction is +you double the concentration of + + align:start position:0% +you double the concentration of + + + align:start position:0% +you double the concentration of +something leaving everything else the + + align:start position:0% +something leaving everything else the + + + align:start position:0% +something leaving everything else the +same and see the effect on rate so again + + align:start position:0% +same and see the effect on rate so again + + + align:start position:0% +same and see the effect on rate so again +these are experimentally determined now + + align:start position:0% +these are experimentally determined now + + + align:start position:0% +these are experimentally determined now +let's consider m equal 2 and notice uh + + align:start position:0% +let's consider m equal 2 and notice uh + + + align:start position:0% +let's consider m equal 2 and notice uh +the blue went away here um and so but + + align:start position:0% +the blue went away here um and so but + + + align:start position:0% +the blue went away here um and so but +it's still there so you can see it all + + align:start position:0% +it's still there so you can see it all + + + align:start position:0% +it's still there so you can see it all +right second order what does the rate + + align:start position:0% +right second order what does the rate + + + align:start position:0% +right second order what does the rate +equal so it would equal K our rate + + align:start position:0% +equal so it would equal K our rate + + + align:start position:0% +equal so it would equal K our rate +constant times the concentration of a + + align:start position:0% +constant times the concentration of a + + + align:start position:0% +constant times the concentration of a +and now we have a two so it's raised to + + align:start position:0% +and now we have a two so it's raised to + + + align:start position:0% +and now we have a two so it's raised to +the power of M and that's two so that's + + align:start position:0% +the power of M and that's two so that's + + + align:start position:0% +the power of M and that's two so that's +how we would write the rate law for + + align:start position:0% +how we would write the rate law for + + + align:start position:0% +how we would write the rate law for +something that was second order in a so + + align:start position:0% +something that was second order in a so + + + align:start position:0% +something that was second order in a so +now let's think about if you double the + + align:start position:0% +now let's think about if you double the + + + align:start position:0% +now let's think about if you double the +concentration of a what would you ex + + align:start position:0% +concentration of a what would you ex + + + align:start position:0% +concentration of a what would you ex +observe for the con the rate what would + + align:start position:0% +observe for the con the rate what would + + + align:start position:0% +observe for the con the rate what would +happen it would quadruple + + align:start position:0% +happen it would quadruple + + + align:start position:0% +happen it would quadruple +right + + align:start position:0% +right + + + align:start position:0% +right +now what about if it triples why don't + + align:start position:0% +now what about if it triples why don't + + + align:start position:0% +now what about if it triples why don't +you tell me what would happen then + + align:start position:0% + + + + align:start position:0% + +all right 10 seconds very + + align:start position:0% + + + + align:start position:0% + +fast 90% yes + + align:start position:0% +fast 90% yes + + + align:start position:0% +fast 90% yes +okay so yes nine + + align:start position:0% +okay so yes nine + + + align:start position:0% +okay so yes nine +times all right and in problem set nine + + align:start position:0% +times all right and in problem set nine + + + align:start position:0% +times all right and in problem set nine +which is already posted um there's all + + align:start position:0% +which is already posted um there's all + + + align:start position:0% +which is already posted um there's all +sorts of problems where you see the + + align:start position:0% +sorts of problems where you see the + + + align:start position:0% +sorts of problems where you see the +effects and you can figure out what the + + align:start position:0% +effects and you can figure out what the + + + align:start position:0% +effects and you can figure out what the +order of the reaction is all right so + + align:start position:0% +order of the reaction is all right so + + + align:start position:0% +order of the reaction is all right so +now let's consider minus1 over here + + align:start position:0% +now let's consider minus1 over here + + + align:start position:0% +now let's consider minus1 over here +which is often not referred to by any + + align:start position:0% +which is often not referred to by any + + + align:start position:0% +which is often not referred to by any +name um the rate here would be equal to + + align:start position:0% +name um the rate here would be equal to + + + align:start position:0% +name um the rate here would be equal to +K concentration of a to the minus + + align:start position:0% +K concentration of a to the minus + + + align:start position:0% +K concentration of a to the minus +one and if we double the concentration + + align:start position:0% +one and if we double the concentration + + + align:start position:0% +one and if we double the concentration +of this you can just yell out what would + + align:start position:0% +of this you can just yell out what would + + + align:start position:0% +of this you can just yell out what would +happen to the rate half + + align:start position:0% +happen to the rate half + + + align:start position:0% +happen to the rate half +yes all right now to m equal minus a + + align:start position:0% +yes all right now to m equal minus a + + + align:start position:0% +yes all right now to m equal minus a +half so the rate here would be k equals + + align:start position:0% +half so the rate here would be k equals + + + align:start position:0% +half so the rate here would be k equals +concentration of a raised to the minus + + align:start position:0% +concentration of a raised to the minus + + + align:start position:0% +concentration of a raised to the minus +one2 and now if we double that's um our + + align:start position:0% +one2 and now if we double that's um our + + + align:start position:0% +one2 and now if we double that's um our +last clicker question on this um sheet + + align:start position:0% +last clicker question on this um sheet + + + align:start position:0% +last clicker question on this um sheet +so why don't you tell me what happens + + align:start position:0% +so why don't you tell me what happens + + + align:start position:0% +so why don't you tell me what happens +and this should be fast too + + align:start position:0% + + + + align:start position:0% + +all right 10 more seconds + + align:start position:0% + + + + align:start position:0% + +all + + align:start position:0% +all + + + align:start position:0% +all +right so going back um over here right + + align:start position:0% +right so going back um over here right + + + align:start position:0% +right so going back um over here right +we have Point uh 7even times which is 2 + + align:start position:0% +we have Point uh 7even times which is 2 + + + align:start position:0% +we have Point uh 7even times which is 2 +to the minus + + align:start position:0% +to the minus + + + align:start position:0% +to the minus +one2 and when you're looking at the + + align:start position:0% +one2 and when you're looking at the + + + align:start position:0% +one2 and when you're looking at the +effects of the rate on concentration + + align:start position:0% +effects of the rate on concentration + + + align:start position:0% +effects of the rate on concentration +you'll see the concentration double and + + align:start position:0% +you'll see the concentration double and + + + align:start position:0% +you'll see the concentration double and +you're like what on Earth happened to + + align:start position:0% +you're like what on Earth happened to + + + align:start position:0% +you're like what on Earth happened to +the rate keep in mind this minus a half + + align:start position:0% +the rate keep in mind this minus a half + + + align:start position:0% +the rate keep in mind this minus a half +um because it's very hard to think about + + align:start position:0% +um because it's very hard to think about + + + align:start position:0% +um because it's very hard to think about +what the relationship is so again they + + align:start position:0% +what the relationship is so again they + + + align:start position:0% +what the relationship is so again they +can be fractions positive or + + align:start position:0% +can be fractions positive or + + + align:start position:0% +can be fractions positive or +negative all right so back up here now + + align:start position:0% +negative all right so back up here now + + + align:start position:0% +negative all right so back up here now +this actually is called half order um so + + align:start position:0% +this actually is called half order um so + + + align:start position:0% +this actually is called half order um so +we would have a rate that is equal to K + + align:start position:0% +we would have a rate that is equal to K + + + align:start position:0% +we would have a rate that is equal to K +times the concentration of a raised to + + align:start position:0% +times the concentration of a raised to + + + align:start position:0% +times the concentration of a raised to +the half and if we double that you can + + align:start position:0% +the half and if we double that you can + + + align:start position:0% +the half and if we double that you can +just yell out what would + + align:start position:0% + + + + align:start position:0% + +happen so 1.4 times the + + align:start position:0% +happen so 1.4 times the + + + align:start position:0% +happen so 1.4 times the +rate and + + align:start position:0% +rate and + + + align:start position:0% +rate and +finally m equals z what do you think uh + + align:start position:0% +finally m equals z what do you think uh + + + align:start position:0% +finally m equals z what do you think uh +that is likely to be + + align:start position:0% +that is likely to be + + + align:start position:0% +that is likely to be +called that is zero order so at least uh + + align:start position:0% +called that is zero order so at least uh + + + align:start position:0% +called that is zero order so at least uh +some things uh are pretty easy to uh to + + align:start position:0% +some things uh are pretty easy to uh to + + + align:start position:0% +some things uh are pretty easy to uh to +guess and if we think about the rate + + align:start position:0% +guess and if we think about the rate + + + align:start position:0% +guess and if we think about the rate +what would the rate be equal + + align:start position:0% +what would the rate be equal + + + align:start position:0% +what would the rate be equal +to just K right it's just going to be + + align:start position:0% +to just K right it's just going to be + + + align:start position:0% +to just K right it's just going to be +equal to K so it doesn't zero + + align:start position:0% +equal to K so it doesn't zero + + + align:start position:0% +equal to K so it doesn't zero +order the a term is not there so if we + + align:start position:0% +order the a term is not there so if we + + + align:start position:0% +order the a term is not there so if we +double the concentration of something + + align:start position:0% +double the concentration of something + + + align:start position:0% +double the concentration of something +that is zero order what happens to the + + align:start position:0% +that is zero order what happens to the + + + align:start position:0% +that is zero order what happens to the +rate nothing right no effect on rate the + + align:start position:0% +rate nothing right no effect on rate the + + + align:start position:0% +rate nothing right no effect on rate the +concentration term isn't part of the + + align:start position:0% +concentration term isn't part of the + + + align:start position:0% +concentration term isn't part of the +equation so the problem set nine will + + align:start position:0% +equation so the problem set nine will + + + align:start position:0% +equation so the problem set nine will +have a lot of experiments and you need + + align:start position:0% +have a lot of experiments and you need + + + align:start position:0% +have a lot of experiments and you need +to figure out by looking at what is + + align:start position:0% +to figure out by looking at what is + + + align:start position:0% +to figure out by looking at what is +happening um what the order of the + + align:start position:0% +happening um what the order of the + + + align:start position:0% +happening um what the order of the +reaction is is it doubling when you + + align:start position:0% +reaction is is it doubling when you + + + align:start position:0% +reaction is is it doubling when you +double the rate is it quadrupling is it + + align:start position:0% +double the rate is it quadrupling is it + + + align:start position:0% +double the rate is it quadrupling is it +doing some weird thing that seems to be + + align:start position:0% +doing some weird thing that seems to be + + + align:start position:0% +doing some weird thing that seems to be +a negative fra an inverse fraction um + + align:start position:0% +a negative fra an inverse fraction um + + + align:start position:0% +a negative fra an inverse fraction um +and that will allow you to figure figure + + align:start position:0% +and that will allow you to figure figure + + + align:start position:0% +and that will allow you to figure figure +out what the order is okay so once you + + align:start position:0% +out what the order is okay so once you + + + align:start position:0% +out what the order is okay so once you +figure out the order of the + + align:start position:0% +figure out the order of the + + + align:start position:0% +figure out the order of the +reaction then the next truth about rate + + align:start position:0% +reaction then the next truth about rate + + + align:start position:0% +reaction then the next truth about rate +laws is that the overall order of the + + align:start position:0% +laws is that the overall order of the + + + align:start position:0% +laws is that the overall order of the +reaction is just the sum of the + + align:start position:0% +reaction is just the sum of the + + + align:start position:0% +reaction is just the sum of the +exponents in the rate law so for example + + align:start position:0% +exponents in the rate law so for example + + + align:start position:0% +exponents in the rate law so for example +if we had this + + align:start position:0% +if we had this + + + align:start position:0% +if we had this +reaction what would be the overall order + + align:start position:0% +reaction what would be the overall order + + + align:start position:0% +reaction what would be the overall order +you can just yell it + + align:start position:0% +you can just yell it + + + align:start position:0% +you can just yell it +out yep it would be a third order the + + align:start position:0% +out yep it would be a third order the + + + align:start position:0% +out yep it would be a third order the +order would be three now you don't some + + align:start position:0% +order would be three now you don't some + + + align:start position:0% +order would be three now you don't some +people get this wrong on a test it's + + align:start position:0% +people get this wrong on a test it's + + + align:start position:0% +people get this wrong on a test it's +like no you want to save your points for + + align:start position:0% +like no you want to save your points for + + + align:start position:0% +like no you want to save your points for +something that's hard 2 + 1 is three so + + align:start position:0% +something that's hard 2 + 1 is three so + + + align:start position:0% +something that's hard 2 + 1 is three so +remember that okay and this would be + + align:start position:0% +remember that okay and this would be + + + align:start position:0% +remember that okay and this would be +then second order in a you would say + + align:start position:0% +then second order in a you would say + + + align:start position:0% +then second order in a you would say +that's first order in B overall third + + align:start position:0% +that's first order in B overall third + + + align:start position:0% +that's first order in B overall third +order so if you're going to lose points + + align:start position:0% +order so if you're going to lose points + + + align:start position:0% +order so if you're going to lose points +on an exam on this + + align:start position:0% +on an exam on this + + + align:start position:0% +on an exam on this +material I recommend losing them + + align:start position:0% +material I recommend losing them + + + align:start position:0% +material I recommend losing them +determining the UNS for the rate + + align:start position:0% +determining the UNS for the rate + + + align:start position:0% +determining the UNS for the rate +constant because that's much more + + align:start position:0% +constant because that's much more + + + align:start position:0% +constant because that's much more +complicated than figuring out the + + align:start position:0% +complicated than figuring out the + + + align:start position:0% +complicated than figuring out the +overall order of the reaction the + + align:start position:0% +overall order of the reaction the + + + align:start position:0% +overall order of the reaction the +units it depends on the order you can + + align:start position:0% +units it depends on the order you can + + + align:start position:0% +units it depends on the order you can +have squared you can have molar squared + + align:start position:0% +have squared you can have molar squared + + + align:start position:0% +have squared you can have molar squared +quadrupled molar to the minus fractions + + align:start position:0% +quadrupled molar to the minus fractions + + + align:start position:0% +quadrupled molar to the minus fractions +all sorts of crazy things happen in your + + align:start position:0% +all sorts of crazy things happen in your + + + align:start position:0% +all sorts of crazy things happen in your +units of Ray constants so save your + + align:start position:0% +units of Ray constants so save your + + + align:start position:0% +units of Ray constants so save your +points if you're going to lose some and + + align:start position:0% +points if you're going to lose some and + + + align:start position:0% +points if you're going to lose some and +I I think it would be great if you got + + align:start position:0% +I I think it would be great if you got + + + align:start position:0% +I I think it would be great if you got +aund everyone got 100 but if you're + + align:start position:0% +aund everyone got 100 but if you're + + + align:start position:0% +aund everyone got 100 but if you're +going to lose some lose them on that + + align:start position:0% +going to lose some lose them on that + + + align:start position:0% +going to lose some lose them on that +that's + + align:start position:0% +that's + + + align:start position:0% +that's +harder Okay so so we'll end there for + + align:start position:0% +harder Okay so so we'll end there for + + + align:start position:0% +harder Okay so so we'll end there for +today and Wednesday we're going to be + + align:start position:0% +today and Wednesday we're going to be + + + align:start position:0% +today and Wednesday we're going to be +talking about um integrated rate laws + + align:start position:0% +talking about um integrated rate laws + + + align:start position:0% +talking about um integrated rate laws +half half life for first order nuclear + + align:start position:0% +half half life for first order nuclear + + + align:start position:0% +half half life for first order nuclear +chemistry it's going to be very exciting + + align:start position:0% +chemistry it's going to be very exciting + + + align:start position:0% +chemistry it's going to be very exciting +and slightly + + align:start position:0% +and slightly + + + align:start position:0% +and slightly +radioactive so where were we we were + + align:start position:0% +radioactive so where were we we were + + + align:start position:0% +radioactive so where were we we were +talking about the fact uh about how you + + align:start position:0% +talking about the fact uh about how you + + + align:start position:0% +talking about the fact uh about how you +measure instantaneous rates and average + + align:start position:0% +measure instantaneous rates and average + + + align:start position:0% +measure instantaneous rates and average +rates and and one of the uh the issues + + align:start position:0% +rates and and one of the uh the issues + + + align:start position:0% +rates and and one of the uh the issues +of doing itics experiments it's all + + align:start position:0% +of doing itics experiments it's all + + + align:start position:0% +of doing itics experiments it's all +experimental you want to measure things + + align:start position:0% +experimental you want to measure things + + + align:start position:0% +experimental you want to measure things +but it can be very challenging to + + align:start position:0% +but it can be very challenging to + + + align:start position:0% +but it can be very challenging to +measure initial rates because you're + + align:start position:0% +measure initial rates because you're + + + align:start position:0% +measure initial rates because you're +often talking about a very small change + + align:start position:0% +often talking about a very small change + + + align:start position:0% +often talking about a very small change +in + + align:start position:0% +in + + + align:start position:0% +in +concentration and so um it can be + + align:start position:0% +concentration and so um it can be + + + align:start position:0% +concentration and so um it can be +helpful sometimes um to use integrated + + align:start position:0% +helpful sometimes um to use integrated + + + align:start position:0% +helpful sometimes um to use integrated +rate laws which allow you to measure um + + align:start position:0% +rate laws which allow you to measure um + + + align:start position:0% +rate laws which allow you to measure um +a lot of different concentrations as + + align:start position:0% +a lot of different concentrations as + + + align:start position:0% +a lot of different concentrations as +times elapses and uh plot that data to + + align:start position:0% +times elapses and uh plot that data to + + + align:start position:0% +times elapses and uh plot that data to +to uh get out rate constants and things + + align:start position:0% +to uh get out rate constants and things + + + align:start position:0% +to uh get out rate constants and things +like that so we're going to talk about + + align:start position:0% +like that so we're going to talk about + + + align:start position:0% +like that so we're going to talk about +integrated rate + + align:start position:0% +integrated rate + + + align:start position:0% +integrated rate +laws and so this is uh the alternative + + align:start position:0% +laws and so this is uh the alternative + + + align:start position:0% +laws and so this is uh the alternative +then is to use this um integrated rate + + align:start position:0% +then is to use this um integrated rate + + + align:start position:0% +then is to use this um integrated rate +law again expresses concentrations + + align:start position:0% +law again expresses concentrations + + + align:start position:0% +law again expresses concentrations +directly as a function of time and gets + + align:start position:0% +directly as a function of time and gets + + + align:start position:0% +directly as a function of time and gets +at this small change changes problem all + + align:start position:0% +at this small change changes problem all + + + align:start position:0% +at this small change changes problem all +right so we're going to talk about first + + align:start position:0% +right so we're going to talk about first + + + align:start position:0% +right so we're going to talk about first +order now and then we'll talk about + + align:start position:0% +order now and then we'll talk about + + + align:start position:0% +order now and then we'll talk about +second order in a little bit so for a + + align:start position:0% +second order in a little bit so for a + + + align:start position:0% +second order in a little bit so for a +first order equation we have a going to + + align:start position:0% +first order equation we have a going to + + + align:start position:0% +first order equation we have a going to +B and we learned last time that we can + + align:start position:0% +B and we learned last time that we can + + + align:start position:0% +B and we learned last time that we can +write a rate + + align:start position:0% +write a rate + + + align:start position:0% +write a rate +expression for a first order process or + + align:start position:0% +expression for a first order process or + + + align:start position:0% +expression for a first order process or +for this process here so we could talk + + align:start position:0% +for this process here so we could talk + + + align:start position:0% +for this process here so we could talk +about the rate expression as The + + align:start position:0% +about the rate expression as The + + + align:start position:0% +about the rate expression as The +Disappearance of a minus D um + + align:start position:0% +Disappearance of a minus D um + + + align:start position:0% +Disappearance of a minus D um +concentration of a DT we can also write + + align:start position:0% +concentration of a DT we can also write + + + align:start position:0% +concentration of a DT we can also write +the rate law for a first order equation + + align:start position:0% +the rate law for a first order equation + + + align:start position:0% +the rate law for a first order equation +and that would be K our rate constant + + align:start position:0% +and that would be K our rate constant + + + align:start position:0% +and that would be K our rate constant +times our concentration so the rate + + align:start position:0% +times our concentration so the rate + + + align:start position:0% +times our concentration so the rate +expression has the DDT and the rate law + + align:start position:0% +expression has the DDT and the rate law + + + align:start position:0% +expression has the DDT and the rate law +has K our rate constant in it all right + + align:start position:0% +has K our rate constant in it all right + + + align:start position:0% +has K our rate constant in it all right +so using these two things that we + + align:start position:0% +so using these two things that we + + + align:start position:0% +so using these two things that we +learned last time we can do a derivation + + align:start position:0% +learned last time we can do a derivation + + + align:start position:0% +learned last time we can do a derivation +to get our integrated first order rate + + align:start position:0% +to get our integrated first order rate + + + align:start position:0% +to get our integrated first order rate +law so in this derivation we're going to + + align:start position:0% +law so in this derivation we're going to + + + align:start position:0% +law so in this derivation we're going to +separate our concentration terms on one + + align:start position:0% +separate our concentration terms on one + + + align:start position:0% +separate our concentration terms on one +side and our time terms on the other + + align:start position:0% +side and our time terms on the other + + + align:start position:0% +side and our time terms on the other +side so we're going to bring over our uh + + align:start position:0% +side so we're going to bring over our uh + + + align:start position:0% +side so we're going to bring over our uh +concentration of a over here so we'll + + align:start position:0% +concentration of a over here so we'll + + + align:start position:0% +concentration of a over here so we'll +divide by the concentration of a + + align:start position:0% +divide by the concentration of a + + + align:start position:0% +divide by the concentration of a +we have our D concentration of a term + + align:start position:0% +we have our D concentration of a term + + + align:start position:0% +we have our D concentration of a term +from here we're going to take our minus + + align:start position:0% +from here we're going to take our minus + + + align:start position:0% +from here we're going to take our minus +side put it on the other side and we're + + align:start position:0% +side put it on the other side and we're + + + align:start position:0% +side put it on the other side and we're +going to take our DT our time term and + + align:start position:0% +going to take our DT our time term and + + + align:start position:0% +going to take our DT our time term and +put it over there as well with our rate + + align:start position:0% +put it over there as well with our rate + + + align:start position:0% +put it over there as well with our rate +constant so we have the terms that have + + align:start position:0% +constant so we have the terms that have + + + align:start position:0% +constant so we have the terms that have +concentration of a on one side and we + + align:start position:0% +concentration of a on one side and we + + + align:start position:0% +concentration of a on one side and we +have our terms with rate constant and + + align:start position:0% +have our terms with rate constant and + + + align:start position:0% +have our terms with rate constant and +time on the other now we can integrate + + align:start position:0% +time on the other now we can integrate + + + align:start position:0% +time on the other now we can integrate +both sides and we will integrate from + + align:start position:0% +both sides and we will integrate from + + + align:start position:0% +both sides and we will integrate from +our original concentration of a so + + align:start position:0% +our original concentration of a so + + + align:start position:0% +our original concentration of a so +that's a to the O for for our original + + align:start position:0% +that's a to the O for for our original + + + align:start position:0% +that's a to the O for for our original +concentration um up to concentration at + + align:start position:0% +concentration um up to concentration at + + + align:start position:0% +concentration um up to concentration at +whatever time T we stopped the + + align:start position:0% +whatever time T we stopped the + + + align:start position:0% +whatever time T we stopped the +experiment and through all the times in + + align:start position:0% +experiment and through all the times in + + + align:start position:0% +experiment and through all the times in +between um over one over the + + align:start position:0% +between um over one over the + + + align:start position:0% +between um over one over the +concentration of a DA and on the other + + align:start position:0% +concentration of a DA and on the other + + + align:start position:0% +concentration of a DA and on the other +side we have our minus rate constant K + + align:start position:0% +side we have our minus rate constant K + + + align:start position:0% +side we have our minus rate constant K +and we're looking at the time from Time + + align:start position:0% +and we're looking at the time from Time + + + align:start position:0% +and we're looking at the time from Time +Zero to time T when we stopped the + + align:start position:0% +Zero to time T when we stopped the + + + align:start position:0% +Zero to time T when we stopped the +experiment all right so we can take this + + align:start position:0% +experiment all right so we can take this + + + align:start position:0% +experiment all right so we can take this +expression now and move it up because I + + align:start position:0% +expression now and move it up because I + + + align:start position:0% +expression now and move it up because I +have more derivations to go so I'm going + + align:start position:0% +have more derivations to go so I'm going + + + align:start position:0% +have more derivations to go so I'm going +to put it on the top of the screen and + + align:start position:0% +to put it on the top of the screen and + + + align:start position:0% +to put it on the top of the screen and +now I am going to solve it um so the + + align:start position:0% +now I am going to solve it um so the + + + align:start position:0% +now I am going to solve it um so the +this integral solves to the natural log + + align:start position:0% +this integral solves to the natural log + + + align:start position:0% +this integral solves to the natural log +of the concentration of a at time T + + align:start position:0% +of the concentration of a at time T + + + align:start position:0% +of the concentration of a at time T +minus the natural log of our original + + align:start position:0% +minus the natural log of our original + + + align:start position:0% +minus the natural log of our original +concentration of + + align:start position:0% +concentration of + + + align:start position:0% +concentration of +a on the other side minus KT our time so + + align:start position:0% +a on the other side minus KT our time so + + + align:start position:0% +a on the other side minus KT our time so +there are two ways we can rewrite this + + align:start position:0% +there are two ways we can rewrite this + + + align:start position:0% +there are two ways we can rewrite this +uh equation we can write it as the + + align:start position:0% +uh equation we can write it as the + + + align:start position:0% +uh equation we can write it as the +equation for a straight line and all I + + align:start position:0% +equation for a straight line and all I + + + align:start position:0% +equation for a straight line and all I +did was take this natural log of a z um + + align:start position:0% +did was take this natural log of a z um + + + align:start position:0% +did was take this natural log of a z um +or a original over + + align:start position:0% +or a original over + + + align:start position:0% +or a original over +here and we could also rearrange this + + align:start position:0% +here and we could also rearrange this + + + align:start position:0% +here and we could also rearrange this +term um instead of minus we have natural + + align:start position:0% +term um instead of minus we have natural + + + align:start position:0% +term um instead of minus we have natural +log of the concentration of a at time T + + align:start position:0% +log of the concentration of a at time T + + + align:start position:0% +log of the concentration of a at time T +over our original + + align:start position:0% +over our original + + + align:start position:0% +over our original +concentration and now we can take the + + align:start position:0% +concentration and now we can take the + + + align:start position:0% +concentration and now we can take the +inverse natur natural log of both sides + + align:start position:0% +inverse natur natural log of both sides + + + align:start position:0% +inverse natur natural log of both sides +and so uh we get rid of natural log here + + align:start position:0% +and so uh we get rid of natural log here + + + align:start position:0% +and so uh we get rid of natural log here +and on the other side we have e to the + + align:start position:0% +and on the other side we have e to the + + + align:start position:0% +and on the other side we have e to the +minus KT again the rate constant times + + align:start position:0% +minus KT again the rate constant times + + + align:start position:0% +minus KT again the rate constant times +the + + align:start position:0% +the + + + align:start position:0% +the +time and then then I can write it break + + align:start position:0% +time and then then I can write it break + + + align:start position:0% +time and then then I can write it break +this out here moving the original + + align:start position:0% +this out here moving the original + + + align:start position:0% +this out here moving the original +concentration of a to this side and now + + align:start position:0% +concentration of a to this side and now + + + align:start position:0% +concentration of a to this side and now +this is the equation for the integrated + + align:start position:0% +this is the equation for the integrated + + + align:start position:0% +this is the equation for the integrated +first order rate law where you have the + + align:start position:0% +first order rate law where you have the + + + align:start position:0% +first order rate law where you have the +concentration of a at some point T + + align:start position:0% +concentration of a at some point T + + + align:start position:0% +concentration of a at some point T +equals its original concentration time e + + align:start position:0% +equals its original concentration time e + + + align:start position:0% +equals its original concentration time e +to the minus K the rate constant times + + align:start position:0% +to the minus K the rate constant times + + + align:start position:0% +to the minus K the rate constant times +the time so if you know a rate constant + + align:start position:0% +the time so if you know a rate constant + + + align:start position:0% +the time so if you know a rate constant +how much time is elapse and you know how + + align:start position:0% +how much time is elapse and you know how + + + align:start position:0% +how much time is elapse and you know how +much you have of something originally + + align:start position:0% +much you have of something originally + + + align:start position:0% +much you have of something originally +you can figure out how much you should + + align:start position:0% +you can figure out how much you should + + + align:start position:0% +you can figure out how much you should +have now or if you figure out how the + + align:start position:0% +have now or if you figure out how the + + + align:start position:0% +have now or if you figure out how the +concentration changes um over time you + + align:start position:0% +concentration changes um over time you + + + align:start position:0% +concentration changes um over time you +can use and how much you had originally + + align:start position:0% +can use and how much you had originally + + + align:start position:0% +can use and how much you had originally +you can calculate um the rate constant + + align:start position:0% +you can calculate um the rate constant + + + align:start position:0% +you can calculate um the rate constant +for that particular material and you can + + align:start position:0% +for that particular material and you can + + + align:start position:0% +for that particular material and you can +do those calculations for rate constants + + align:start position:0% +do those calculations for rate constants + + + align:start position:0% +do those calculations for rate constants +by plotting using this equation for a + + align:start position:0% +by plotting using this equation for a + + + align:start position:0% +by plotting using this equation for a +straight line so here I'm going to plot + + align:start position:0% +straight line so here I'm going to plot + + + align:start position:0% +straight line so here I'm going to plot +natural log of a so I measured the + + align:start position:0% +natural log of a so I measured the + + + align:start position:0% +natural log of a so I measured the +concentration in a at various different + + align:start position:0% +concentration in a at various different + + + align:start position:0% +concentration in a at various different +times Against Time + + align:start position:0% +times Against Time + + + align:start position:0% +times Against Time +and we have an equation for a straight + + align:start position:0% +and we have an equation for a straight + + + align:start position:0% +and we have an equation for a straight +line so we should get a straight line if + + align:start position:0% +line so we should get a straight line if + + + align:start position:0% +line so we should get a straight line if +this is a first order + + align:start position:0% + + + + align:start position:0% + +process and so what would uh this be up + + align:start position:0% +process and so what would uh this be up + + + align:start position:0% +process and so what would uh this be up +here what is the Y + + align:start position:0% + + + + align:start position:0% + +intercept what is + + align:start position:0% + + + + align:start position:0% + +it yeah so that's a natural log of our + + align:start position:0% +it yeah so that's a natural log of our + + + align:start position:0% +it yeah so that's a natural log of our +original + + align:start position:0% +original + + + align:start position:0% +original +concentration and this you can yell more + + align:start position:0% +concentration and this you can yell more + + + align:start position:0% +concentration and this you can yell more +loudly uh what is our + + align:start position:0% + + + + align:start position:0% + +slope yes it's a little bit easier to + + align:start position:0% +slope yes it's a little bit easier to + + + align:start position:0% +slope yes it's a little bit easier to +yell loudly minus + + align:start position:0% +yell loudly minus + + + align:start position:0% +yell loudly minus +K so you can experimentally determine + + align:start position:0% +K so you can experimentally determine + + + align:start position:0% +K so you can experimentally determine +the rate constant from this so if you + + align:start position:0% +the rate constant from this so if you + + + align:start position:0% +the rate constant from this so if you +measure how the concentration of a + + align:start position:0% +measure how the concentration of a + + + align:start position:0% +measure how the concentration of a +changes with time plot your data natural + + align:start position:0% +changes with time plot your data natural + + + align:start position:0% +changes with time plot your data natural +log of those concentrations versus time + + align:start position:0% +log of those concentrations versus time + + + align:start position:0% +log of those concentrations versus time +get a lot of data points from the slope + + align:start position:0% +get a lot of data points from the slope + + + align:start position:0% +get a lot of data points from the slope +you can measure the rate constant and so + + align:start position:0% +you can measure the rate constant and so + + + align:start position:0% +you can measure the rate constant and so +rate constants for a lot of different + + align:start position:0% +rate constants for a lot of different + + + align:start position:0% +rate constants for a lot of different +materials have already been measured in + + align:start position:0% +materials have already been measured in + + + align:start position:0% +materials have already been measured in +this kind of way way all right so for a + + align:start position:0% +this kind of way way all right so for a + + + align:start position:0% +this kind of way way all right so for a +first order process this is these are + + align:start position:0% +first order process this is these are + + + align:start position:0% +first order process this is these are +important equations but also for first + + align:start position:0% +important equations but also for first + + + align:start position:0% +important equations but also for first +order we spend a lot time talking about + + align:start position:0% +order we spend a lot time talking about + + + align:start position:0% +order we spend a lot time talking about +Half-Life so halflife is the time it + + align:start position:0% +Half-Life so halflife is the time it + + + align:start position:0% +Half-Life so halflife is the time it +takes for half of the original material + + align:start position:0% +takes for half of the original material + + + align:start position:0% +takes for half of the original material +to go away so it's a really easy thing + + align:start position:0% +to go away so it's a really easy thing + + + align:start position:0% +to go away so it's a really easy thing +it is I like it when things are called + + align:start position:0% +it is I like it when things are called + + + align:start position:0% +it is I like it when things are called +what they + + align:start position:0% +what they + + + align:start position:0% +what they +are and uh here the time involved has a + + align:start position:0% +are and uh here the time involved has a + + + align:start position:0% +are and uh here the time involved has a +little special abbreviation t a half so + + align:start position:0% +little special abbreviation t a half so + + + align:start position:0% +little special abbreviation t a half so +whenever you see t a half that's talking + + align:start position:0% +whenever you see t a half that's talking + + + align:start position:0% +whenever you see t a half that's talking +about a + + align:start position:0% +about a + + + align:start position:0% +about a +halflife so we can derive this + + align:start position:0% +halflife so we can derive this + + + align:start position:0% +halflife so we can derive this +expression as well for the first order + + align:start position:0% +expression as well for the first order + + + align:start position:0% +expression as well for the first order +halflife using the Expressions that we + + align:start position:0% +halflife using the Expressions that we + + + align:start position:0% +halflife using the Expressions that we +just looked + + align:start position:0% +just looked + + + align:start position:0% +just looked +at so from uh the expression we had + + align:start position:0% +at so from uh the expression we had + + + align:start position:0% +at so from uh the expression we had +above where we had the natural log of + + align:start position:0% +above where we had the natural log of + + + align:start position:0% +above where we had the natural log of +the concentration of a at time T over + + align:start position:0% +the concentration of a at time T over + + + align:start position:0% +the concentration of a at time T over +original concentration equals minus the + + align:start position:0% +original concentration equals minus the + + + align:start position:0% +original concentration equals minus the +rate constant K * time and now we can + + align:start position:0% +rate constant K * time and now we can + + + align:start position:0% +rate constant K * time and now we can +substitute in so we're not interested in + + align:start position:0% +substitute in so we're not interested in + + + align:start position:0% +substitute in so we're not interested in +just any old time we're interested in + + align:start position:0% +just any old time we're interested in + + + align:start position:0% +just any old time we're interested in +time a half so we're going to want to + + align:start position:0% +time a half so we're going to want to + + + align:start position:0% +time a half so we're going to want to +put a half in there and that is the time + + align:start position:0% +put a half in there and that is the time + + + align:start position:0% +put a half in there and that is the time +it takes for the original amount to go + + align:start position:0% +it takes for the original amount to go + + + align:start position:0% +it takes for the original amount to go +to half so to be divided by two so we + + align:start position:0% +to half so to be divided by two so we + + + align:start position:0% +to half so to be divided by two so we +can put that in so now our a t our + + align:start position:0% +can put that in so now our a t our + + + align:start position:0% +can put that in so now our a t our +concentration of a at times T is our + + align:start position:0% +concentration of a at times T is our + + + align:start position:0% +concentration of a at times T is our +original concentration divided by two + + align:start position:0% +original concentration divided by two + + + align:start position:0% +original concentration divided by two +and our T is t a half so you'll see that + + align:start position:0% +and our T is t a half so you'll see that + + + align:start position:0% +and our T is t a half so you'll see that +the a Zer terms are going to cancel out + + align:start position:0% +the a Zer terms are going to cancel out + + + align:start position:0% +the a Zer terms are going to cancel out +and you're going to end up with natural + + align:start position:0% +and you're going to end up with natural + + + align:start position:0% +and you're going to end up with natural +log of a half equal minus k + + align:start position:0% +log of a half equal minus k + + + align:start position:0% +log of a half equal minus k +times our half life T a half and so then + + align:start position:0% +times our half life T a half and so then + + + align:start position:0% +times our half life T a half and so then +we can uh put in our value for the + + align:start position:0% +we can uh put in our value for the + + + align:start position:0% +we can uh put in our value for the +natural log of a half and get rid of all + + align:start position:0% +natural log of a half and get rid of all + + + align:start position:0% +natural log of a half and get rid of all +those minus signs and rearrange it and + + align:start position:0% +those minus signs and rearrange it and + + + align:start position:0% +those minus signs and rearrange it and +so then our half life for this first + + align:start position:0% +so then our half life for this first + + + align:start position:0% +so then our half life for this first +order process is going to be equal to + + align:start position:0% +order process is going to be equal to + + + align:start position:0% +order process is going to be equal to +9631 divided K the rate constant so + + align:start position:0% +9631 divided K the rate constant so + + + align:start position:0% +9631 divided K the rate constant so +you'll note a couple of uh perhaps + + align:start position:0% +you'll note a couple of uh perhaps + + + align:start position:0% +you'll note a couple of uh perhaps +important things about this expression + + align:start position:0% +important things about this expression + + + align:start position:0% +important things about this expression +and one of the important things is that + + align:start position:0% +and one of the important things is that + + + align:start position:0% +and one of the important things is that +half life doesn't depend on the + + align:start position:0% +half life doesn't depend on the + + + align:start position:0% +half life doesn't depend on the +concentration so the concentration term + + align:start position:0% +concentration so the concentration term + + + align:start position:0% +concentration so the concentration term +has dropped out so what does halflife + + align:start position:0% +has dropped out so what does halflife + + + align:start position:0% +has dropped out so what does halflife +depend on then if it doesn't depend on + + align:start position:0% +depend on then if it doesn't depend on + + + align:start position:0% +depend on then if it doesn't depend on +the concentration again this is for + + align:start position:0% +the concentration again this is for + + + align:start position:0% +the concentration again this is for +first order so it's going to depend on K + + align:start position:0% +first order so it's going to depend on K + + + align:start position:0% +first order so it's going to depend on K +that's all that's in there there's only + + align:start position:0% +that's all that's in there there's only + + + align:start position:0% +that's all that's in there there's only +one thing that's in there there's a + + align:start position:0% +one thing that's in there there's a + + + align:start position:0% +one thing that's in there there's a +number a constant and there's K so + + align:start position:0% +number a constant and there's K so + + + align:start position:0% +number a constant and there's K so +halflife depends on K this rate constant + + align:start position:0% +halflife depends on K this rate constant + + + align:start position:0% +halflife depends on K this rate constant +and the rate constant depends on the + + align:start position:0% +and the rate constant depends on the + + + align:start position:0% +and the rate constant depends on the +material in question so different + + align:start position:0% +material in question so different + + + align:start position:0% +material in question so different +materials will have different values of + + align:start position:0% +materials will have different values of + + + align:start position:0% +materials will have different values of +rate constant and we just saw how you + + align:start position:0% +rate constant and we just saw how you + + + align:start position:0% +rate constant and we just saw how you +can calculate a rate constant you can + + align:start position:0% +can calculate a rate constant you can + + + align:start position:0% +can calculate a rate constant you can +measure it um from uh and get the slope + + align:start position:0% +measure it um from uh and get the slope + + + align:start position:0% +measure it um from uh and get the slope +of the line and tells you about what K + + align:start position:0% +of the line and tells you about what K + + + align:start position:0% +of the line and tells you about what K +is all right so let's use this + + align:start position:0% +is all right so let's use this + + + align:start position:0% +is all right so let's use this +expression now and why don't you tell me + + align:start position:0% +expression now and why don't you tell me + + + align:start position:0% +expression now and why don't you tell me +for the same material um which of these + + align:start position:0% +for the same material um which of these + + + align:start position:0% +for the same material um which of these +thing Pro which of these events will + + align:start position:0% +thing Pro which of these events will + + + align:start position:0% +thing Pro which of these events will +take + + align:start position:0% + + + + align:start position:0% + +longer all right 10 more seconds + + align:start position:0% + + + + align:start position:0% + +so it takes in fact the same amount of + + align:start position:0% +so it takes in fact the same amount of + + + align:start position:0% +so it takes in fact the same amount of +time because the concentration doesn't + + align:start position:0% +time because the concentration doesn't + + + align:start position:0% +time because the concentration doesn't +show up in there and it was the same + + align:start position:0% +show up in there and it was the same + + + align:start position:0% +show up in there and it was the same +material all right so before we move + + align:start position:0% +material all right so before we move + + + align:start position:0% +material all right so before we move +away from this you can write same amount + + align:start position:0% +away from this you can write same amount + + + align:start position:0% +away from this you can write same amount +of time in your notes let's take a look + + align:start position:0% +of time in your notes let's take a look + + + align:start position:0% +of time in your notes let's take a look +at this plot on the bottom of the page + + align:start position:0% +at this plot on the bottom of the page + + + align:start position:0% +at this plot on the bottom of the page +and just think about what's happening + + align:start position:0% +and just think about what's happening + + + align:start position:0% +and just think about what's happening +because you can talk about a first half + + align:start position:0% +because you can talk about a first half + + + align:start position:0% +because you can talk about a first half +life and a second half life and a third + + align:start position:0% +life and a second half life and a third + + + align:start position:0% +life and a second half life and a third +half life so we can just fill this right + + align:start position:0% +half life so we can just fill this right + + + align:start position:0% +half life so we can just fill this right +in so for a concentration at your first + + align:start position:0% +in so for a concentration at your first + + + align:start position:0% +in so for a concentration at your first +halflife how much is + + align:start position:0% +halflife how much is + + + align:start position:0% +halflife how much is +left so what's this number the + + align:start position:0% +left so what's this number the + + + align:start position:0% +left so what's this number the +concentration is what half second half + + align:start position:0% +concentration is what half second half + + + align:start position:0% +concentration is what half second half +life what do we + + align:start position:0% +life what do we + + + align:start position:0% +life what do we +got .25 + + align:start position:0% +got .25 + + + align:start position:0% +got .25 +third .125 right so this is pretty easy + + align:start position:0% +third .125 right so this is pretty easy + + + align:start position:0% +third .125 right so this is pretty easy +to think about but sometimes when you + + align:start position:0% +to think about but sometimes when you + + + align:start position:0% +to think about but sometimes when you +have data and you're looking at it you + + align:start position:0% +have data and you're looking at it you + + + align:start position:0% +have data and you're looking at it you +have to remember what the sort of + + align:start position:0% +have to remember what the sort of + + + align:start position:0% +have to remember what the sort of +possibilities are okay so that's first + + align:start position:0% +possibilities are okay so that's first + + + align:start position:0% +possibilities are okay so that's first +order halflife and that's the end of + + align:start position:0% +order halflife and that's the end of + + + align:start position:0% +order halflife and that's the end of +this lecture but we're not really moving + + align:start position:0% +this lecture but we're not really moving + + + align:start position:0% +this lecture but we're not really moving +away from the topic because now we're + + align:start position:0% +away from the topic because now we're + + + align:start position:0% +away from the topic because now we're +going to talk about example of a first + + align:start position:0% +going to talk about example of a first + + + align:start position:0% +going to talk about example of a first +order process which is radioactive decay \ No newline at end of file diff --git a/BLExWo9Empk.txt b/BLExWo9Empk.txt new file mode 100644 index 0000000000000000000000000000000000000000..21049bc1c3d9986bbdd9e8b81ee72f8f559f745a --- /dev/null +++ b/BLExWo9Empk.txt @@ -0,0 +1,3633 @@ +The following +content is provided + +under a Creative +Commons license. + +Your support will help MIT +OpenCourseWare continue + +to offer high quality +educational resources for free. + +To make a donation, or to +view additional materials + +from hundreds of MIT courses, +visit MIT OpenCourseWare + +at ocw.mit.edu. + +PROFESSOR: Are you guys +excited about Battlecode? + +I'm so excited to +see this many-- Yeah! + +Yeah, let's hear a +hurray-- no, no a yeah. + +Are you excited? + +AUDIENCE: Yeah! + +PROFESSOR: All right, +that was a strong yeah. + +I actually mean that. + +I have a strange thing +where when I say something + +it often comes out like I meant +the opposite of what I said, + +like I didn't believe it. + +Like that time that Drew +Houston-- from Dropbox, + +he's the Dropbox CEO-- do +you guys remember this? + +He was giving his sponsor talk +at the finals of Battlecode + +last year and he was +just wrapping up, + +and everybody was +applauding, and I + +came to the podium I was +like, thanks, thanks Drew. + +That was really good. + +That made me want +to work at Dropbox. + +If I didn't have a +job already I would. + +And nobody believed +me, they thought + +I was just being facetious. + +So, now he hates me. + +That's too bad. + +That happens to me. + +OK, let's get started soon. + +So you're all here +because you're + +interested in Battlecode. + +These lectures are optional. + +They're geared at beginner +to mid-level coders, + +but they'll be +relevant even if you've + +had coding experience +in a million languages. + +Because we're +going to be talking + +a lot of the time about +Battlecode, the game itself. + +And it could just be a +way to keep yourself up + +to date on the latest +metagame, for example. + +So we're going to go +over the specs today. + +I'm going to introduce +the competition. + +And then after +lecture today, we'll + +be having a lab, during +which we'll help you set up. + +So I see a lot of you brought +your computers, that's + +fantastic. + +And that's also great because +it means if you get bored, + +you can just watch +YouTube videos. + +Yeah, so make sure to bring +your ear plugs so that you don't + +bother the guy next to +you, because he's already + +heard Gangnam Style. + +All right so be +respectful of those guys. + +So here's our introduction. + +My name is Maxwell Mann, I'll +be your lecturer for the next 10 + +days. + +It actually is minus 4 days +because of various things. + +So it's like the +next two weeks, you + +can come here at this +time-- or slightly earlier, + +so you can hear a lousy +joke --you can come here, + +and you can hear me +talk about the game, + +and hear what the +devs think about what + +you might need to know. + +And then you can eat +food at 6:00 PM, when + +we have massive +quantities of food coming, + +and then from 6:00 to +7:00, you have the option + +of staying for the lab session, +which has been described, + +in anticipation, +as a social utopia. + +And I really believe +that it could be one, + +because everybody here has, +sort of, some similar interests. + +So to introduce +us, we developers, + +are students, or +alums, who have worked + +on developing Battlecode. + +I'm Max. + +Sitting here in the +front is Aaron Epstein + +and Steven Valdez. + +You'll be using them for help, +all the time, if you need it, + +or just to bother them +because you feel like it. + +They're here for +no other reason, + +and to maintain the code base +and these kinds of things. + +The website is battlecode.org +and we have a forum there, + +where you could +also go to get help. + +And I also, +particularly, would like + +to direct your attention +to the IRC channel. + +It's #battlecode on Freenode. + +So I don't know if +you know what that is, + +but it's basically +a way that you + +can talk to us on +a real time chat. + +So you can do that at pretty +much any hour of the day, + +because the way +we're setting it up + +this year is we'll all +be available, pretty + +much the whole time. + +OK, make sure that if +you are an MIT student, + +and you want credit +for this class-- + +it's a six credit +class --you just + +have to sign up on +WebSIS for 6.S187. + +How many people have signed +up on WebSIS already? + +All right, that's +like everybody. + +Let's talk about the +goals of the competition. + +What is a game? + +What are we doing? + +I'm sure a lot of you are +thinking all right, well, here + +we go. + +I've got finals +tomorrow but I have + +to decide what IAP +classes to take. + +Gosh, this is a terrible +combination of deadlines. + +Then you thought, +should I take-- + +should I to do battle code? + +Should I do one of these other +things, like web programming, + +or game programming? + +What is the operating +systems whatshumadoosits? + +Should I do this or that? + +And you're probably thinking +to yourself, what is fun? + +What is valuable for me? + +What am I going to learn? + +And we ask ourselves +the same question. + +A couple months +before then was, what + +do we want the Battlecode +competition to be like? + +And what we ended +up deciding, was + +that the game needs +to be fun and it + +needs to contain classic +battle code areas of challenge + +in artificial intelligence. + +So this is a game that +is a cross-- we've always + +said in the past that +it is not StarCraft + +--but it is a cross between +a real-time strategy + +game and an AI +programming competition. + +So what we wanted was the +game to be easy to learn, + +but hard to master. + +So what you'll see when I +describe the game specs-- + +and I'm going into it just +momentarily --when I describe + +game specs you'll see ways +to play the game, and then + +ways to excel at the game. + +So it's like you've got +this infinite ramp, that you + +can run wild on, of +how much effort you + +want to put into +developing the best player. + +Or better yet, because +what is the best? + +It's comparative. + +That's comparing +to somebody else. + +But that's kind of irrelevant. + +What you want is to have fun. + +Anyway, you know that. + +So there we go. + +Our idea was to not +have sort of skill caps + +and limiting factors, +like maps that are just + +covered in maze so +you can't do anything + +unless you can get +past that maze. + +Like, OK, you didn't +pass the test, + +I hope you enjoy +your starting area. + +No, no. + +So not that. + +So let me show the game. + +How many of you have +seen Battlecode before? + +A show of hands. + +So that's a good number, +but it's not everybody. + +So I'm going to show you a game. + +So this is when +you've made your code + +and you've put it +into the client, + +you can run a game +like this, and we'll + +go over how to do that. + +And I'll just hit +play here, and you'll + +see the red team +in the upper left, + +and the blue team +in the bottom right, + +playing a game of +Battlecode for this year. + +The player on the +upper left, in red, + +is placing mines, +and capturing bases. + +His soldiers are moving around +and fighting with one another. + +Fighting the enemy, hopefully. + +And the blue player, +here at the bottom right, + +is just sort of +shooting his guys off + +to die at the enemy army. + +On the left you'll +see indicators + +of various game constants +and values that are changing. + +If I pause this +for a second, you + +can see by clicking +on any robot, + +you can see his ID number, +what robot type it is. + +You can see his hit +point level, which + +we have characteristically had +a very difficult to remember + +name for. + +We always have different names +for their energy and their head + +points this year it's going to +be, "energon," for hit points. + +I think this flux number is +actually no longer relevant, + +and you can ignore it. + +[AUDIENCE LAUGHTER] + +PROFESSOR: See, +we worked so hard + +on making this +polished and perfect, + +that we weren't finished +until-- actually we're + +not finished yet, they're +still fussing with something. + +[AUDIENCE LAUGHTER] + +PROFESSOR: The +bytecodes used is going + +to be a key factor that you're +going to look at so that you + +can determine how much +computational energy + +those robots are spending. + +This year, there's +a very big impact + +on the efficiency of your +code, and the performance + +of your player. + +If you have efficient code, you +could have twice as many robots + +on the field then +you can sustain + +if your code is inefficient. + +Because the actual +computational cost + +is recorded, and +is then implemented + +into the upkeep of each unit. + +Finally, you'll see the +location of the unit, and three + +indicator strings that you can +use for debugging and control + +purposes. + +So what we'll do today is talk +about what kinds of things + +are on this map, and how that's +different and amazingly great, + +and how this year's new gameplay +will be even more fun than it + +ever has been. + +And I can say that +with some confidence, + +because it's quite different +and demonstrably better. + +Yes. + +So what we think of +as skill areas, areas + +that make a fun +game for Battlecode, + +are, navigation-- but not +that you so much require + +it --see, in this example, +they didn't really + +need any complex maze +solving algorithms. + +What they were just doing, is +there are these neutral mines + +that are here, and you +could either walk around + +the neutral minefield, +or you could just + +clear yourself +right on through it. + +So there's navigation, +but you don't necessarily + +have to do it. + +[AUDIENCE LAUGHTER] + +PROFESSOR: There's +group pathing-- + +and that's a good point +because, you know, + +OK, anybody can take one +unit and after enough time, + +figure out how to implement +any of the existing pathing + +algorithms. + +But let's say you've +got multiple units. + +They start to get in +one another's way. + +Let me give an example +that's very concrete, + +and that hits really +close to home, for me. + +I did this all the time-- +I've done Battlecode, + +I guess, like four years now. + +And so what I'd always +have is, I'm here, + +and I want to go to ice +cream-- something desirable + +--and I'm trying to +get past this wall. + +So I go here, but then all my +friends take up all this space + +because they're +going the same way. + +And then I'm trying to +turn around, and go back, + +and they're trying to +go this way because they + +think it's closer +to the ice cream. + +And we just end up here +all day, and then the enemy + +comes by and shoots us. + +And then we've got +holes in ourselves, + +how are we going to +maintain that stomach + +area to keep the ice cream in? + +It's just not going to work. + +So we like navigation, +we like group pathing. + +We like messaging. + +This year, the messaging +system is totally new. + +In the past, what +you'd need is-- + +I'm going to go +back to the screen + +here --is your +robot would only be + +able to see a certain +area around himself. + +And so every other +robot would not + +know what's going on, on the +whole map, except by messaging. + +But even then, they would +have to receive messages + +that are broadcast +within a certain range. + +So you end up having to make +these chains where you'd + +say, all right, +I've got, let's see, + +Joe, and James, and Jalopy. + +They're all in line, and these +three robots are in line, + +and they each have +some broadcast radius. + +And so maybe I can, sort +of, set up a relay chain, + +and they're broadcasting back. + +And that was how you used +to communicate information + +about where the enemy is. + +So here's the ice cream, +here, and here's me. + +And I would have to hear +it from these four guys. + +But that would end up +being a lot of work + +for me to implement. + +And we like that, we +think that's really cool. + +But at the same time +it ended up meaning + +that if the ice +cream were an enemy, + +and I needed to scout +that the enemy were coming + +with some rush, that +what would often happen + +is that there wouldn't +be a chain established. + +Because this kind of +stuff's kind of hard do. + +So this guy would see the enemy +right here-- and here's me, + +back here, I'm just +minding my own business. + +Maybe I'm building a staircase, +which we did in one year. + +Or some other very useful +expenditure of effort and time. + +So this guy sees the enemy +and I don't know about it, + +I can't prepare +until he comes back. + +OK, so then he comes back +to within broadcast range-- + +he's here --but by then +the enemy is right there. + +I can't do anything. + +So what we've done +this year, is we've + +said all right, realistically +we've got these radios, right? + +Let's communicate, on these +radios, across the whole map. + +So now your radio messages can +be heard across the whole map. + +But, instead of being messages, +like they used to be-- + +and these messages +were kind of annoying, + +they were these constructs +that you had to assemble. + +You'd say, oh, I'm +making a new message + +and I'm applying +these parts to it. + +And not every message +has every type of part. + +And not every part as +every type of message. + +And every time I +receive a message + +I can receive an +infinity of messages. + +And then my robot +explodes because he's + +being overloaded with messages. + +That's like spam, happens +a lot, it happens to me. + +So what we get instead, +is we said, all right, + +we've got a uniform +message channel. + +We've got 10,000 channels. + +And any robot can +post an integer + +to any one of those +channels, at any time. + +So then my robot could be +posting-- maybe my code + +is using frequency 567. + +And I'll be communicating on +that frequency specifically + +where I'm going, or what +direction I'm going, + +or something like that. + +And everybody on +my team can see it. + +So that's a really useful +sort of centralizing feature. + +So if the enemy is +coming, I can just + +look on integer number 567, and +if the enemy is coming, maybe + +that's a flag, +maybe I make that, I + +guess, 666 because +that's really bad. + +Right? + +So I make that my token for +enemy is coming, and then bing, + +everybody can start preparing +for the enemy coming. + +But there's more, +I mean, let's say + +you're going to metagame them. + +You're going to think about what +could happen from a high level. + +Like when would the +enemy just invade? + +When would they attack me? + +I mean, I don't have to see them +coming to know that they will. + +For example, maybe the +map is really small. + +So this year, you can +tell how big the map is. + +I mean, how does it make sense-- +this happened again and again + +in previous years --how +does it make sense + +to have a game, where players +are expected to operate + +intelligently, in the +absence of information. + +OK, I understand that sometimes +a little bit of uncertainty + +can be great. + +Like how great poker +be if everybody + +knows what everybody +else's hand is? + +That would be +really lousy, right? + +But here, we just had +almost no information, + +so you'd have +build-order losses. + +This is sort of a big problem, +in my eyes, with StarCraft. + +Which is that you'd start +with a strategy that + +could lose before you have any +information on how to fix that. + +So at least in StarCraft +you know how big the map is. + +So here we're giving them +the following centralized + +information. + +So here's what I'll do. + +I'm going to list out the +centralized information + +that you can use, that +you didn't really used + +to have access to. + +Now you might ask, all right +I'm not going to memorize this, + +and I'm not taking +notes-- even though I + +did bring a thingamabober, which +is a computer, or a notebook. + +You might say, I'm not +going to memorize this, + +I'm not interested, +I'm here to have fun. + +Well look here, you can +look in the Java docs + +and you can see all of +the robot abilities. + +They're listed in +this giant list here, + +and you'll have time +to peruse those. + +And we'll sort of go +over them over the course + +of the few lectures. + +But having them sort +of in a condensed form + +or organized into +topics, like what + +is centralized information? + +You know, what +information can I use? + +Ends up probably being +a bit of a convenience. + +So I have a couple of convenient +organizations of data. + +And that's really all +I'm here for is just-- + +you can get all this information +in our documentation, + +which we'll supply you when +we help you set up the game. + +And/or you can sort of hear +it from me, where I've got it + +sort of organized into a +slightly different way. + +The centralized +info that you get + +includes, you can sense the +positions of all allied robots. + +So there's a function, and +again, we have very good naming + +conventions so that all +of the names that we pick + +let you know exactly +what we're referring to. + +And for this function we call +it-- it's a method called, + +"Sense Nearby Game Objects." + +And that's great because +it can detect game objects + +across the map, anywhere, +they don't have to be nearby. + +So that that's really nice. + +And it senses these things, +which of course, you + +would want to sense. + +They're objects! + +You know, I was playing chess +the other day with my friend + +Rick, and I said +to him, you know + +what I could use more +of is game objects. + +I can sense all of +your game objects. + +And he didn't get it. + +[AUDIENCE LAUGHTER] + +PROFESSOR: So Sense +Nearby Game Objects + +is an overloaded +function, which means + +that you can call it +with multiple arguments. + +And that really does help you. + +So the point is, this +is a global function, + +because you can see any game +object if that game object is + +of a certain type. + +So all of your allied +robots you can see. + +Let's go back to our example, +let's say that I am back here, + +that's me, over +here at the bottom. + +And this guy up +at the top, I can + +see where he is back from here. + +But my sight range is +actually only here. + +So I've got different +detection abilities. + +Allied robots, allied +mines, and neutral mines, + +are all visible no +matter where you are, + +but enemy robots are only +visible within your sight + +radius. + +But it's within any +allied robot site radius. + +It's harder to explain +than it is to think about. + +In this picture, this +robot can see these guys, + +because he's really close. + +But this guy can also see them, +because this robot is nearby. + +Right, that's pretty +straightforward. + +One person was nodding +but he was also yawning, + +so he may have been nodding off. + +No, I'm only joking. + +Yeah, zing! + +[AUDIENCE LAUGHTER] + +PROFESSOR: Sense +Nearby Game Objects + +is a kind of useful +thing to be able to do, + +but it's not always +obvious how to use it. + +So, later on, I'll +be talking about how + +one of the inputs to +this is what type of game + +object you want. + +I still haven't-- I've been +saying game object over + +and over, but none of you +care about game objects. + +You care about +enemy robots, I want + +to shoot at the enemy robots. + +So you would end up writing, +oh, I want a robot please. + +So you tell it, give me game +objects of type Robot.class. + +And you would say, +all right, this + +is getting kind of confusing. + +I'm feeling a little +bit overwhelmed. + +Well don't you worry about it, +because here in the Java Docs, + +under package-- and you might +notice that this is the Java + +docs version 7, +for Java version 7. + +It's real sleek. + +We're distributing this +at absolutely no cost. + +Yeah. + +Let's see here, oh, look! + +It's game object. + +There it is. + +And oh, look, subinterfaces +include encampments and robots. + +Well that's great, that +answers my question. + +So now I know that I can put +Robot.class or Encampment.class + +and it will give me that +type of game object. + +Yeah. + +Yeah! + +All right. + +[LAUGHS] + +So that's a piece of +centralized information. + +Another piece of +centralized info-- + +so we've talked about +how it's allied robots. + +There's allied mines. + +I'll talk about the mines and +how you can lay them and defuse + +them, and how you get these +things onto the game board. + +Allied robots, allied mines. + +You've got the radio system, +which is entirely global. + +And that means that you can +disrupt somebody else's radio + +program. + +I have a hunch that there are +several people out there who + +would broadcast random numbers +to my favorite channel, 567, + +and it would just +totally ruin my player. + +I wouldn't be able +to work at all. + +Now, in order to limit +this sort of-- there's sort + +of a back and forth +between sending messages + +that you want to send, +receiving the messages + +with a certain amount of, +sort of, redundancy in there, + +so you can be safe +against message jamming, + +versus actual jamming itself. + +How do we assess the balance +of these competing objectives? + +Well we've got a cost +associated with everything. + +There's no free lunch. + +Except dinner for Battlecode. + +And that is actually free. + +We ordered so much +pizza for today. + +Now I'm sure not many of you +ordered that much pizza before. + +But let me tell +you that I expected + +that-- there's like 120 +people here in the room, + +and we thought how much +pizza does everybody eat? + +Well unfortunately Battlecode +is a male dominated class. + +So we'll have slightly +more pizza consumption + +than otherwise. + +Is that sexist? + +And so-- + +[AUDIENCE LAUGHTER] + +PROFESSOR: So we decided +to get 50 pizzas. + +And we were like, well +what's awesome pizza? + +We like Bertucci's. + +You guys don't like Bertucci's. + +Yeah! + +He likes Bertucci's. + +Yeah, so that was +like $20 a pizza. + +So it was like $1000 for pizza. + +[AUDIENCE LAUGHTER] + +PROFESSOR: My goodness. + +Well anyway, it's going +to be really good. + +And it's coming in +like a half an hour. + +That's fantastic-- I've totally +lost my train of thought. + +[AUDIENCE LAUGHTER] + +PROFESSOR: Right I was + +AUDIENCE: --message him. + +PROFESSOR: Yeah. + +I was saying that there's +no free lunch, and as such, + +we have a bytecode cost. + +Now, I think in the past it's +not been that obvious to me + +what the cost of doing a +certain computation is. + +Can I jam the enemy? + +Is that really going to work, or +am I going to run out of money? + +Is a question you could ask. + +So here, in the-- +let's see here, + +I have a place where I +have installed Battlecode. + +And you're going to +do something just + +like this, where you'll have +that Battlecode-- that's OK, + +he had to go to the bathroom. + +Don't worry about him. + +[AUDIENCE LAUGHTER] + +PROFESSOR: Well it's a +reasonable supposition, + +he is human, isn't he? + +All right, and so here, in +the Battlecode directory + +where I've installed +Battlecode, there's + +going to be a text file +that's called method costs. + +Bingo. + +All right now it +looks disorganized + +because everything-- the +strings are different lengths. + +But each string represents +a function that you can use. + +Like for example attack square. + +Or maybe broadcast a message. + +Ah, that was the one +we were interested in. + +OK, let's look at that. + +Broadcast costs 25 bytecodes. + +All right, let's do a little +bit of math-- arithmetic, + +it's not math, is it? + +25 bytecodes, all right? + +There are 10,000 strings, +which I wrote and erased. + +10,000 places to +write a message to. + +There are 25 bytecodes +to broadcast a message. + +OK, so that means that I +can broadcast 400 messages. + +Is that right? + +Is that this number divided by +that number equals that number? + +Is that-- Yeah, yeah. + +Yeah, let's go with it. + +Yeah, let's go with that. + +So you have 400. + +No, but maybe you have more of +your robots jamming signals. + +OK, how many robots +can you have? + +All right, let's do +that computation. + +I'm pretending that I'm you, +and that I'm just like-- OK + +I'm not doing a very +good impersonation. + +I recognize that. + +You'd be much faster at this. + +So you would want to find +out how many robots you + +can sustain. + +Can I get somebody to +suggest one way to figure out + +that number? + +Yes! + +You, you, you. + +Ah yes you could make a +player and just spawn robots + +until they start dying. + +Let's say you wanted to +do it in a different way. + +[AUDIENCE LAUGHTER] + +PROFESSOR: I have +the example here. + +What is It? + +Game constants, there we are. + +So here I'm looking +at the Java docs, + +and I can click +on game constants. + +I'm looking at a +different version of it + +that didn't actually show the +game constants in the game + +constants page. + +But that's because we +are well organized. + +And this is to show that we're +indomitable, indefatigable, + +as it were. + +These constant values +indicate, here, + +that your headquarters +is capable of producing + +quite a few resources. + +This shows that it produces +50 resources per turn. + +This resource +production enables you + +to have an upkeep of robots. + +So in the past, we've had +names like flux, and so on. + +This year, the name +for it is power. + +That's tough though because +we have time as well. + +And as you well know power +times time is energy. + +And so now we have +energon and energy, + +which is a multiple or a +calculated quantity from power. + +But don't you worry +too much about it. + +It's just a number. + +And the usage of this +resource, or power, by robots, + +is displayed in unit upkeep. + +Which here, is +written incorrectly. + +I'm going to be +bring up the most + +recent version of this document. + +What's nice is that you +guys will get one version, + +and then you'll have one +version on your computer + +and not, like, 16. + +And your one version +will be up to date. + +And when you want to +update it, the client + +will automatically tell +you that it needs updating. + +So you'll just have +the one version, + +and you won't have +disaster area. + +Yeah, constant value. + +So this is the more +recently updated one. + +And you can see here the +unit power upkeep is one. + +All right, fantastic. + +We're ready to do a computation. + +So I'm going to +put here 40 divided + +by-- so this is the +amount of energy, + +or the amount of +power, that's produced + +per turn by your +headquarters divided + +by the usage of that power. + +Now you're going to say, +all right, I'm bored. + +I can do this in my head. + +Well maybe you can but some +of us can't, all right? + +No, so that would be the number. + +But that would say that the +number of robots you get + +is independent of how +much work they're doing. + +And that doesn't make any sense. + +You should get to +have more robots + +if you're doing +less computation. + +So here you can see, +there is a cost. + +Power cost per +bytecode, which is here. + +And it's 10 to the minus 4. + +So let's say that I'm +using-- 10 to the minus 4 + +times the number bytecodes. + +Well, if I'm using zero +byte codes, then I get 40. + +Because that would be 1 plus 0. + +And 40 over one is 40. + +OK and if I were +using 10,000, which + +is also known as 10 to the 4. + +Then I would get 20. + +Wow, what a big difference. + +So that tells you that if +you want to go ahead and spam + +the message system-- +let's say you're spamming, + +so you're using all of +your bytecodes possible, + +and you have 20 robots. + +So 20 robots are spamming 400 +message integers per turn. + +So you're doing nothing +but spamming the messages. + +And you're getting eight, +zero, zero, ze-- Oh, ahh, ahh. + +Oh, it's not even enough. + +It's not enough. + +Well, so that shows that +you could jam the enemy. + +And maybe you should, if you've +got nothing better to do, + +if you derive a personal +satisfaction from it. + +But this is worth saying. + +These kinds of calculations +are important for strategy. + +But don't make them +totally fixed in stone. + +Because we change +the game, we tweak + +it a little bit for balance. + +So if it ends up being that +10,000 is just so much radio + +space that we just would +rather not have it, + +then it could just get +knocked down to 1000. + +And then all of a sudden +your player, which + +depends on this or that +messaging construct, + +may have to be +somewhat rethought. + +So this is a good time to +talk about the organization + +of the competition. + +Is it? + +I think it is. + +Let's go to the +Battlecode website. + +And let me show you something. + +I don't know I knew +that you could do this. + +But previous years +we've had like a list. + +And it'll be in +text form, and it'll + +say on this date we have this +competition, and this one. + +And then you have to +open up a window of this. + +And then every single +one of you opens up + +another window with +Gmail or Google Calendar. + +And then you like manually enter +in the-- do you not do that? + +Who has to do that whenever +you have a competition, + +you want to know +when things are? + +Yeah, yeah there's +like two people who + +also have to do that. + +So I figured, in light of saving +those two people some effort, + +we made this Google Calendar. + +And you could see, here's +today's classroom session, + +here in 1-190 from +5:00 to 6:00 PM. + +And it's got the +lab written there. + +So the specs and software are +released, as of 37 minutes ago, + +roughly speaking. + +And what we'll +do, after this, is + +we'll talk about +how to set it up. + +So there you go, specs +and software are released. + +The sprint tournament +is on the 14th. + +And what that means is you +can submit a player for that, + +and you can be entered for a +relatively small prize pool. + +Relatively small, +the actual prize + +pool for the finals +is I think $50,000. + +So relatively small +is just some fraction + +of that which is +still non-negligible. + +Anyway, so that's going to be +really exciting because that + +will give you the opportunity +to test your code out + +to see what other players +are doing, because to + +some extent winning +is going to be + +related to what other people do. + +But more importantly, +having fun is + +related to what other +people do, and talking + +to the other people. + +Like this social utopia of +mine, the idea of this lab, + +is totally new-- as well +as the Google Calendar + +--to try to make things more +easy and fun and together, + +among us as Battlecoders. + +Because we do all +share that common link. + +Yes. + +So the point is +that if you didn't + +know you could do +this, what you do + +is you go to-- if you want to +add this to your own calendar, + +there's like a button where +you can go and do that. + +I think the button isn't +available because-- Yeah, + +there. + +There? + +At the bottom. + +At the bottom? + +Yeah, there you go. + +And then you just +add it right in, + +so I've already got it here, +in my personal calendar. + +And there you go, so +you can see that I'm + +having lunch on the 24th. + +And OK, so you get the idea. + +So the sprint tournament +is-- the submission deadline, + +you can see here, +is on the 14th. + +On the 16th, on that +Wednesday, in class, + +we'll show some of the games +from the sprint tournament. + +I don't think we'll +show all of them. + +See because what used to happen, +is we would show all the games. + +And there's like 100 teams. + +And that ends up being +a relatively large size + +round-robin bracket with, I +think, double elimination. + +So it's a ton of games. + +I think it generally +takes like five hours. + +But it ends up bumping up to +six, seven, or eight hours + +because we end up +showing up there, + +and the tournament code that +sets it all up doesn't work. + +And so it takes forever. + +So we're going to +do this year is + +we'll just sort to +distill it down, + +we'll have something +simple to show + +that's fantastic and +exciting on the Wednesday. + +And in the future, when we +have our later-- our seating + +tournament, which is sort +of the same kind of thing, + +but it's more important, because +it determines your positioning + +for the final tournament. + +When we have this +seating tournament, + +we're going to live +stream it on the internet, + +so that you don't +even have to-- I mean, + +you guys all trekked out +here in the dead of night + +and 5:00 or 6:00 PM +in the freezing cold. + +I mean there could be people out +there dying because they tried + +to make it here and +they didn't make it. + +That would be horrible, that's +not something to laugh at. + +So you came all +the way out here, + +but we don't want to make you +have to do that much work. + +Because we want you to have fun. + +So there you go. + +We've got a calendar to +save you that effort. + +We have lab sessions to save +you the effort of trying + +to make friends, and +we'll have live streams + +in the future, which will +make that much better. + +So as you can see here, it +says the seating tournament + +submission deadline +is on the 21st. + +And the seating tournament +will be on the 22nd. + +So what that does, is it gets +you your position in the finals + +tournament. + +The finals submission +deadline is different, though. + +So you can continually +update your player. + +My point is that you +only have three weeks. + +It's the 7th today. + +And the finals submission +deadline is the 28th. + +You have three weeks to +make an amazing player. + +And each week, you'll +have the chance + +to-- you could upload +your player at any time, + +you can do scrimmage matches +with other players at any time. + +And then finally, you'll be +able to submit to the finals. + +I mean, I don't think it's +worth getting too hyped up + +about this final thing because +after all, in my experience, + +game changes at the last minute +screw you over at the finals, + +and ends up being a crap shoot. + +No, no, I exaggerate. + +But the point is, the fun +should be had as you go. + +And I am here to help with that. + +So what you need-- +so just one more + +thing about this +administration is + +that I think that it's required +that you upload a resume, + +and that you be an MIT student +if you want to earn-- no, + +that's not right. + +We have international +competitors, this year. + +We have sort of a thing going on +with the University of Sussex. + +If you have friends +at other universities, + +they can feel free to join you. + +And they don't have +to be MIT students + +to either play or win money. + +And if they're in +Honolulu, or Alaska, + +we'll fly them in +here for the finals + +because we expect the finalists +to show up at this dinner + +that we have at the Hyatt. + +We have this fantastically +lavish dinner. + +I think we paid +like $5,000 for it. + +Aaron, could you +come up here and show + +what the sponsors +are by just turning + +your back to the audience? + +No, actually there's a +button here, I can do that. + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: Yeah, +that's a good point. + +OK, so here are our sponsors. + +We have these fancy company +reps show up at this dinner. + +So if you're among +the finalists, + +then you show up at +the fancy reps dinner + +and they offer you +jobs and stuff. + +It's apparently very +nice, I've never been. + +AUDIENCE: [AUDIENCE LAUGHTER] + +Yeah, that's because I was busy. + +Yeah, that's why. + +Yeah, that's why. + +That's why. + +No. + +So these are some +of the sponsors. + +Our main sponsors +and some other ones. + +And you'll get a chance to meet +them, as well, at the finals. + +So you don't have to be the best +of the best by whatever stupid + +metric we come up with. + +What you have to +be is-- anybody who + +does Battlecode is an attractive +person to these employers who + +will meet you and give +you business cards. + +And it'll be a good +time for everyone. + +And so in that note +you have, once again, + +on the calendar page, the finals +are on the 2nd of February. + +So that'll be when that +happens and it'll be in 26-100. + +It'll be a blast, and you +should be looking forward + +to that very much. + +I feel like I've +just been droning on, + +ranting about what I don't +like about StarCraft. + +And I haven't talked enough +about the things that + +are related to +gameplay this year. + +This year, you +have these robots. + +It's astounding to me, that I-- +Oh, is that why it didn't work? + +Because I was using this +one instead of this one, + +and I meant to use +this main client? + +Yeah, that's the one. + +OK, yeah. + +This was the point I was +trying to make earlier. + +Where I was going to +take compute time bot, + +playing against compute +time bot, on this map. + +This is sort of how +to do it, but it'll + +be done a little +bit differently. + +And so the goal here is to see +how many robots can be built. + +But this guy-- Ah! + +I think team A and +B got switched. + +So what I'll do is I'll just +briefly switch around the code. + +So this is sort of the +structure of a robot controller. + +What happens is this code is +run on each robot on your team, + +and that's what plays the game. + +I'm sure most of you +know that already. + +And so what I'll do is I'll +just check that the team is B. + +So I can switch the team, +hit Save, run it again. + +Well it doesn't +work as well as I + +was expecting because +these guys are just + +dying when they go +through the minefield. + +That's interesting. + +[AUDIENCE LAUGHTER] + +PROFESSOR: You know, you can +make your own maps in this. + +This is a really good +example of debugging. + +And you can say that +I did this on purpose. + +Although if you have a +strict adherence to honesty, + +you might not. + +So the maps are located where? + +You're looking at what, here? + +So you'll have a directory +where you can see your maps. + +And you'll be also +able to see them here. + +So here's simple. + +And what if I want +to edit this map. + +Can I do that? + +Can I just double click it? + +It's an XML document. + +Oh, look. + +Is it? + +Oh, data, OK. + +Here's some data. + +I'm beginning to get +to the part-- see, + +this would be really +easy if I could just + +do edit with notepad. + +AUDIENCE: --source at the bottom + +PROFESSOR: Source! + +No. + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: Tab. + +AUDIENCE: No, down. + +PROFESSOR: Down? + +Down. + +AUDIENCE: Where design is. + +PROFESSOR: Oh! + +Bingo. + +All right! + +Yeah, thank you. + +So then, you can +see that I can make + +my own maps using these codes. + +So the character "3" +indicates a neutral mine. + +So I can just do like a find +replace, were I'll replace "3" + +with ".", which is +an open terrain. + +I'll just do replace all. + +And then I'll just +make sure to change + +this one or else the +whole map would be mines. + +I'm sure two of you thought +that I wouldn't do that, + +but I assure you that I'm +operating at full capacity. + +All right, so this is an +example where you can see I've + +just built bunch of robots. + +And you can see that +this is my power. + +Your power stored +in a reserve bank. + +And what I'm going to do +is suddenly at round 1,000, + +I'm going to start +computing a lot. + +So right now you can +see that this robot + +is using 38 bytecodes. + +Not very many. + +If you're amazing +at counting you'll + +see that there +are about 40 here. + +And the new robots-- oh, boom! + +Look at that. + +The new robots died because they +don't have enough-- these guys + +don't have enough compute-- they +don't have enough power to run. + +So they lose hit points +until they're dead. + +And then if they all +start using code, + +boom, when we cut down +to half the number. + +And so you could +see quite visually + +the effect of using 10,000 +bytecodes versus using + +no bytecodes at all. + +So from here, down to there. + +Bang. + +This power quantity can be +affected by various things. + +So there are some equations that +I could show for what that is. + +But maybe I've just gone +a bit far field here + +because I've been talking +about some details. + +Here's the general +overview, right? + +You don't really need too +many of the specifics, + +because all you've got +to do is find the enemy. + +And there's a function +that does that. + +Oh, look at that, I'll just +add that to the global list. + +There's, "Sense Enemy +Headquarters," bingo. + +Done. + +If you were interested in +a little bit of masochism, + +coding masochism, and just +doing something the hard way, + +you could do that. + +Because what we've +also provided, + +is the dimensions +of the map, and you + +know that the upper left +corner of the map is 0,0. + +So with a symmetry +operation you could say, + +my headquarters is here. + +The map size is this. + +My location is here. + +Therefore, the enemy must +be at this other location. + +So more than one way to skin +a cat, as the case may be. + +So you locate the enemy, +and all you have to do + +is walk up to him. + +Because this year attacking +happens automatically + +for soldiers. + +So right now there isn't +any fighting going on. + +But I'll show an +example that will + +show that all they've got to +do is go near one another, + +and then their attack +power is distributed + +among all of the +robots they can see. + +So this is some old +code that we were + +writing when we were +testing the game. + +And what you'll +find is that when + +robots come close +to one another, + +they make these circles that +indicate their attack range. + +So they're attacking-- this +guy is distributing his attack + +among this one and that one. + +Similarly, this one is +distributing among these three. + +So his attack power in +this version of the game + +was different. + +But right now I believe +the attack power is six. + +So he would be dealing two +damage to each of these. + +What you also see in +this picture, which + +I believe is quite instructive, +is the shield robots. + +Yeah, any robot that's standing +next to this shields robot + +will be given this +additional shields parameter. + +And so you can see it here +in the user interface. + +There's a green bar +indicating health, + +and a blue bar +indicating shields. + +In the latest implementation +of Battlecode, + +shields serve as +a protection only + +against a certain type of +encampment that can be built. + +So is these encampments +work in the following way. + +You start with just +a headquarters, + +and that produces +these soldiers. + +So you can produce a soldier +at any tile around you, + +if that tile is unoccupied. + +That soldier can then be used +to construct an encampment. + +And he can construct any of a +number of types of encampment. + +So I've made this nice, handy, +useful Battlecode data sheet. + +People from last +year might remember + +that I made sort of a handy +unit sheet at that time. + +But this year it's 100% more +accurate than last year's. + +That's right. + +We've checked and +double checked, + +but this is the latest version. + +So you can see here all of +the different types of units. + +And there's a Boolean for +whether it is an encampment, + +in terms of just a description. + +Although, you know, that's kind +of not a fantastic description. + +Because all of these +units-- you know, + +because we like to +be straightforward. + +It's a realistic +preparation for your life + +as a professional coder, that +the database and documentation + +you receive will contain +information opposite to the way + +that things are run. + +So you can see here that they're +all listed-- some of these + +are listed as encampments. + +But in fact they are all robots. + +Yes, I believe that's correct. + +They are all robots. + +So the headquarters is +what you start with. + +It generates 40 power turn, and +it can spawn these soldiers. + +It takes 10 turns +to spawn a soldier. + +Or it can research upgrades, +and I'll talk about the upgrades + +below, in just a minute. + +The soldier has an upkeep +of 1 to 2 power per turn, + +depending on byte code usage. + +It automatically +distributes its attack power + +among adjacent enemy units. + +And it has the +capability of laying + +mines, which take 25 +turns to lay a mine. + +Defusing mines, which take +5 turns, and capturing + +encampments, which +takes 50 turns. + +Now you might ask, +all right, where + +am I getting these numbers? + +I'm assembling this +sort of convenient + +diagram but what if +the specs change? + +You know, where do +I get these numbers? + +Well they're all under game +constants under robot type + +enum, or the upgrade +enum, and you'll + +find them all the Java docs. + +Alternatively, you +could all always + +ask us where they are by +going on our IRC chat, + +or talking to one +of us in person. + +So you can see here they're +laying mines, defusing mines, + +capturing encampments. + +And in the act of capturing +one of these encampments, which + +is a pre-existing location on +the map, these black circles. + +In the act of capturing +one of those-- + +there's nothing +magical about it. + +Because here, among the +robot controller methods, + +you'll find capture encampment. + +And what you'll do is +you'll specify what type + +of enchantment +you want it to be. + +And you might ask, +what types are there? + +Well, you could either +look at handy chart, + +or you could click +here, under robot type. + +And this enum robot type +will show you the types + +that you can build. + +You can build artillery, +generator, medbay, shields, + +and supplier. + +The headquarters and +soldier are different. + +They're not built +from encampments. + +I don't know if that's written +anywhere, but I've said it, + +so now you know it. + +Yeah. + +So that's how you're going to be +able to build these units, that + +are shown here. + +So the medbay heals adjacent +robots, 2 hit points per turn. + +You can see that's their quote, +"attack power," because attack + +is a lot like healing. + +You know, modern surgery, +you can use scalpel and such. + +These are also +considered weapons. + +I'm sure you couldn't +bring a scalpel on a plane. + +So attack is a really good word +for healing-- a healing unit. + +And if you don't believe me talk +to any medicine man you know. + +Shields will give +all adjacent robots + +5 shield points per turn. + +So if you cluster 8 +units around them, + +then that'll go ahead and give +40 shield points distributed + +among them, to the extent +that 5 times 8 is 40. + +The shields only protect +you from artillery, though. + +They don't protect you +against other soldiers. + +Now, these robots +that are shielded + +will lose 1 shield point +per turn, as it wears off. + +But there's no cap on the +amount of shields they can have. + +So they can have, I think, +10 to the 8th shields. + +Which is like a lot more than +their total hit points of 40. + +Right? + +So that's effectively infinite. + +The artillery is the one unit +that can shoot at a far range. + +It could shoot at a range of 63. + +Now we always talk +about squared ranges, + +because that makes it +easier to do comparisons + +without having to +take a square root. + +Although I guess if we +did give you ranges, + +and not squared ranges, you +could just square it and then + +compare it to the range that +you had just calculated. + +this way works really well. + +So what I can do is I can +demonstrate for you what that + +looks like by opening +up-- oh my goodness, + +I'm almost out of time. + +I can open up this stockpiling-- +no, that's not right. + +I made it in the map +maker program, down here. + +Yeah, so this shows +you what 63 looks like. + +So if you're here in the middle, +you can see all of these tiles + +but you can't see +the ones outside. + +But its site range is only 14. + +Every robot has a site range +of 14, As you can see here, + +in this document. + +So the attack range is +63, the site range is 14. + +So, this is one of +those cases where + +you'd need scouting units that +would know what to shoot at. + +And it's really helpful that you +have this global information. + +Because you don't +need to post to radio + +to tell the artillery +what to shoot at. + +Because he can already +see all of the unit + +that your allies can see. + +He can't necessarily +see the enemies, + +unless your guys are nearby. + +So, yes, the artillery does +40 damage to the target + +that it specifies, and 20 +splash damage to adjacent tiles. + +And that does include +friendly fire, + +so you've got to be careful +about where you shoot. + +The generator generates +10 resources per turn. + +And that resource is power. + +So that's added on to +your headquarter power. + +So if you build a +bunch of generators, + +you can support more soldiers. + +And finally, the +supplier will reduce + +the build time for +soldiers by 5%. + +And that's multiplicative. + +So if you have two +suppliers, then it's + +0.95 squared times 10 turns. + +This year, we give +you the opportunity + +of building upgrades as +well, researching upgrades + +at your headquarters. + +So your headquarters +is your central unit, + +the goal is to defeat +the enemy headquarters. + +To do that, you could just +walk your robots on over + +and kill them dead. + +It's not required that +you research upgrades + +and built encampments. + +And that's one of +the ways that we + +make the competition +somewhat easier to enter, + +easier to get +something that works. + +But if you want to +research upgrades, + +to make a strategy +that's tailored + +around a certain approach, +then you can get these. + +The future upgrade +reduces your energy decay + +because the way +that you hold power, + +is that you can't just +mass it up indefinitely. + +You get a power income +from your headquarters, + +and you spend power to +upkeep your soldiers. + +But we don't want that-- +if you have no soldiers + +and you're just +getting income, we + +don't want that to +go up indefinitely. + +So every turn that +gets multiplied + +by a number that reduces it. + +So the energy decay, +or the loss is 20%. + +But if you research fusion, +the loss is only 1%. + +So then you might think +of stockpiling energy + +and then spending it all +at once to get a larger + +burst of robots, which couldn't +be sustained for a long time. + +But then again, you only +have to win one second. + +Finally, the-- OK, so then +there's more upgrades. + +Vision upgrade extends your +squared vision from 10 to 32. + +This should say 14, but +as you know everything + +is always up to date +100 percent of the time. + +So here's a demonstration of +what that would look like. + +Here's 10 and here's 32. + +Boom, what a big difference. + +That's quite a lot more vision. + +That's important because +you can defuse any mine + +within your site range if you +have the diffusion ability. + +Which is not to be confused +with chemical diffusion, which + +is something else. + +Yes, this is for +defusing things, + +and it is spelled correctly. + +[AUDIENCE LAUGHTER] + +PROFESSOR: So yeah, that extends +your mine defusing range. + +That's pretty important, +but keep in mind + +that you can still only +defuse one at a time. + +So you have to select which +one you're going to defuse. + +And then you defuse that. + +Now, it's important +to note that you + +can see where-- I've said that +you see your allied mines. + +I haven't said that you can +see your neutral mines as well. + +But you don't see enemy mines +until one of your robots + +has stepped on it. + +So that means that you can't-- +I don't think you can defuse + +something you can't see. + +But actually I don't know, +I'll have to check with that. + +Because it may be that +you could just spam + +defuse on terrain +that you don't know. + +And that might actually defuse +things that you can't see. + +At the same time, that's +not a fantastic strategy, + +because defused takes 5 turns. + +And during those 5 +turns you cannot attack. + +So that leaves you-- +or can you attack? + +I'm thinking maybe +you can attack. + +[AUDIENCE LAUGHTER] + +PROFESSOR: You know what, you +can't-- it's a very vulnerable + +position, to be +defusing something. + +Because you're concentrating +on something else. + +How do you going to +perform as effectively + +on a different task? + +Pickaxe is the tool +that you really + +need if you want to +lay a ton of mines. + +Because instead of laying just +one mine, where your robot is-- + +I guess I'm going +to have to come up + +with a system for +describing robot-- + +that's sort of like a robot. + +Maybe it's a Chinese character. + +So that's a robot, +and ordinarily he + +would lay a mine here, +but if you have pickaxe, + +he will lay mines in +all of these positions + +for the same cost of +laying just one mine. + +Pretty useful to have. + +And it takes the same amount. + +So laying a mine cost +25 rounds, defusing + +a mine costs five rounds. + +So you could do the math. + +If you have pickaxe, +you could lay them + +as fast as the other +team can defuse them, + +provided you can get into an +open space where you can do it. + +Realistically they might be +able to encroach, and get you + +during that time. + +And why do you +want to lay mines? + +Doesn't that slow the game down? + +Doesn't that mean +that things will just + +move to slowly, make it +a boring thing to watch? + +I would say no, because +during that time + +you could be researching +the nuclear missile. + +That's right. + +That's right, we +knew that it would + +be interesting to watch +players build nuclear missiles. + +If you research that, +you win immediately. + +So-- + +[AUDIENCE LAUGHTER] + +That's yet another +fun way to win, + +and I'm going to show you an +example of somebody attempting + +to win that way. + +This will only take as +much time as it took me + +the last time I tried to do it. + +It's under-- golly, you won't +have nearly-- oh, it's right + +here. + +It must be so hard to watch +me, because it's like, oh man, + +he's looking right at it. + +Let's see, so let's +put do nothing bot-- + +because that's a decent +match for the nuke bot. + +Where is he? + +Is he not here? + +AUDIENCE: No, he's +in the middle. + +PROFESSOR: He's in the middle. + +Oh, I'm looking right at him. + +All right. + +All right, well it's by no +means a foregone conclusion + +who wins this match. + +This is an old version +of the code where + +nuking took 1,000 turns +instead of 400 turns. + +But that's not to say that +the red team will necessarily + +win on turn 1,000. + +Oh wait. + +It could only take 400 +turns wait a minute. + +Oh, that's 1,000 and +this was-- OK yeah, hey! + +It happened. + +There you go. + +So yeah, the nuclear +missile has-- I mean, + +it's not a very +impressive graphic. + +[AUDIENCE LAUGHTER] + +PROFESSOR: It's +technically the same one + +we use for every +other explosion. + +[AUDIENCE LAUGHTER] + +PROFESSOR: But I think what +we'll do is for the finals, + +we've got a new +match visualizer. + +So this was an old +version of the code, + +because of course I wouldn't +show you something up to date. + +That would be that help +you instead of hinder you. + +And what we're trying to do +is train you to be amazing. + +And it's working, I swear. + +So what I'll do is I'll show +this version of it, which + +is great, because it shows +the thing researching. + +All right, well later +versions of the client + +that you're going +to receive will + +show what things are researching +in the client window. + +And I think it really would +not be in an excessive-- + +the pizza should be +arriving any moment, + +so I know that the +gurgling of your stomachs + +is totally reasonable and +will be resolved imminently. + +If I run this version, +then I think-- let's see, + +is there-- so let's put do +nothing against the nuke guy. + +Is the nuke guy still there? + +He is, OK. + +So this version of +the map viewer shows + +researches that are going on. + +Yeah. + +And you can see he's researching +pickaxe, diffusion, sight + +range, the fusion +thing that reduces + +the amount of energy loss. + +He's researching everything. + +And whereas the other do +nothing guy-- you know, + +you could describe +him as a pacifist. + +The philosophy that +he is developing, + +using three bytecodes per +round, may change the world. + +So I see no reason to hate +on his choice of vocation. + +I would definitely not-- +yeah, no, definitely. + +OK. + +So you can see here that +nuke is researching. + +So in a tournament +scenario we could all + +start getting excited +and going ohhhhh! + +What's going to happen? + +Is it going to be close? + +And that sort of thing. + +I mean of course at +the end it's going + +to be a bit of an +anti-climax because it's + +going to show a +little puff ball, + +like somebody made +popcorn on one tile. + +But we'll be able to overcome +that because we can just + +switch to YouTube +and show a clip + +of some giant nuclear test. + +All right, that's all +I have for you now. + +I mean to say that +we're going to show + +you a whole bunch of things. + +You can get up and go, +I know a lot of you + +have appointments with very +attractive young women and men. + +And that's totally OK. + +But I recommend that you +stick around, eat some pizza, + +hear about how to +set up Battlecode. + +And know that we will have +our developer testing code up. + +The team name, here on +the Battlecode website. + +You can see here, team list. + +We just made a team that you can +use to test your code against. + +That's down here at the bottom. + +It's test, somewhere. + +Yeah, Teh Devs +Test, there you go. + +Did you guys make this many +teams in the last 2 seconds? + +You must have. + +You know, it's +important to multitask. + +Yeah, so you can +upload your player + +and test it against +Teh Devs test player. + +And that'll be +available all the time, + +and that's probably +sort of your first step + +on your road to success. + +Thank you very much for coming, +and if you have any questions + +you can come to us after. + +[APPLAUSE] \ No newline at end of file diff --git a/BLb0l_K0MWM.txt b/BLb0l_K0MWM.txt new file mode 100644 index 0000000000000000000000000000000000000000..290afbdfe38f2ed44b06169327402eeae2aab1c9 --- /dev/null +++ b/BLb0l_K0MWM.txt @@ -0,0 +1,14811 @@ +align:start position:0% + +all right so welcome back been a bit of + + align:start position:0% +all right so welcome back been a bit of + + + align:start position:0% +all right so welcome back been a bit of +a break um you may yes exactly why are + + align:start position:0% +a break um you may yes exactly why are + + + align:start position:0% +a break um you may yes exactly why are +we here what are we doing with our lives + + align:start position:0% +we here what are we doing with our lives + + + align:start position:0% +we here what are we doing with our lives +we're learning about plasma Diagnostic + + align:start position:0% +we're learning about plasma Diagnostic + + + align:start position:0% +we're learning about plasma Diagnostic +and you may remember before uh we went + + align:start position:0% +and you may remember before uh we went + + + align:start position:0% +and you may remember before uh we went +away uh we spent a very enjoyable + + align:start position:0% +away uh we spent a very enjoyable + + + align:start position:0% +away uh we spent a very enjoyable +lecture drawing all sorts of diagrams + + align:start position:0% +lecture drawing all sorts of diagrams + + + align:start position:0% +lecture drawing all sorts of diagrams +like this where we had some energy + + align:start position:0% +like this where we had some energy + + + align:start position:0% +like this where we had some energy +levels here maybe this is + + align:start position:0% +levels here maybe this is + + + align:start position:0% +levels here maybe this is +ionization energy level this is maybe + + align:start position:0% +ionization energy level this is maybe + + + align:start position:0% +ionization energy level this is maybe +some lower energy level and something + + align:start position:0% +some lower energy level and something + + + align:start position:0% +some lower energy level and something +happened photons were flying around + + align:start position:0% +happened photons were flying around + + + align:start position:0% +happened photons were flying around +electrons were flying + + align:start position:0% + + + + align:start position:0% + +around and we said that if we want to + + align:start position:0% +around and we said that if we want to + + + align:start position:0% +around and we said that if we want to +understand what the ionization state is + + align:start position:0% +understand what the ionization state is + + + align:start position:0% +understand what the ionization state is +in our plasma and also the excitation + + align:start position:0% +in our plasma and also the excitation + + + align:start position:0% +in our plasma and also the excitation +state which would be if you have some + + align:start position:0% +state which would be if you have some + + + align:start position:0% +state which would be if you have some +intermediate level here which I guess + + align:start position:0% +intermediate level here which I guess + + + align:start position:0% +intermediate level here which I guess +I've already used I so I have to come up + + align:start position:0% +I've already used I so I have to come up + + + align:start position:0% +I've already used I so I have to come up +with some other notation for it m like + + align:start position:0% +with some other notation for it m like + + + align:start position:0% +with some other notation for it m like +that maybe we want to know how many + + align:start position:0% +that maybe we want to know how many + + + align:start position:0% +that maybe we want to know how many +electrons are in this intermediate level + + align:start position:0% +electrons are in this intermediate level + + + align:start position:0% +electrons are in this intermediate level +in the lower level in the upper level + + align:start position:0% +in the lower level in the upper level + + + align:start position:0% +in the lower level in the upper level +because at the end of the day in + + align:start position:0% +because at the end of the day in + + + align:start position:0% +because at the end of the day in +spectroscopy what we're detecting is + + align:start position:0% +spectroscopy what we're detecting is + + + align:start position:0% +spectroscopy what we're detecting is +photons which are being emitted and the + + align:start position:0% +photons which are being emitted and the + + + align:start position:0% +photons which are being emitted and the +photons are being emitted when an + + align:start position:0% +photons are being emitted when an + + + align:start position:0% +photons are being emitted when an +electron drops down either from being a + + align:start position:0% +electron drops down either from being a + + + align:start position:0% +electron drops down either from being a +free electron into a bound state or + + align:start position:0% +free electron into a bound state or + + + align:start position:0% +free electron into a bound state or +between two bound States and we went + + align:start position:0% +between two bound States and we went + + + align:start position:0% +between two bound States and we went +through all these processes and we said + + align:start position:0% +through all these processes and we said + + + align:start position:0% +through all these processes and we said +you know if we really want to understand + + align:start position:0% +you know if we really want to understand + + + align:start position:0% +you know if we really want to understand +the plasma we need to model all of these + + align:start position:0% +the plasma we need to model all of these + + + align:start position:0% +the plasma we need to model all of these +processes and obviously that's an awful + + align:start position:0% +processes and obviously that's an awful + + + align:start position:0% +processes and obviously that's an awful +lot so today I'm going to go through and + + align:start position:0% +lot so today I'm going to go through and + + + align:start position:0% +lot so today I'm going to go through and +I'm going to present present a some + + align:start position:0% +I'm going to present present a some + + + align:start position:0% +I'm going to present present a some +simplified equilibria in which we do not + + align:start position:0% +simplified equilibria in which we do not + + + align:start position:0% +simplified equilibria in which we do not +need to include all of these processes + + align:start position:0% +need to include all of these processes + + + align:start position:0% +need to include all of these processes +and these are the equilibria which we + + align:start position:0% +and these are the equilibria which we + + + align:start position:0% +and these are the equilibria which we +tend to have a better chance of modeling + + align:start position:0% +tend to have a better chance of modeling + + + align:start position:0% +tend to have a better chance of modeling +and youone remember what this process + + align:start position:0% +and youone remember what this process + + + align:start position:0% +and youone remember what this process +was called here this is my personal + + align:start position:0% + + + + align:start position:0% + +favorite when you have two electrons in + + align:start position:0% +favorite when you have two electrons in + + + align:start position:0% +favorite when you have two electrons in +an excited state uh and one of them + + align:start position:0% +an excited state uh and one of them + + + align:start position:0% +an excited state uh and one of them +drops down and that provides enough + + align:start position:0% +drops down and that provides enough + + + align:start position:0% +drops down and that provides enough +energy for the other electron to ionize + + align:start position:0% +energy for the other electron to ionize + + + align:start position:0% +energy for the other electron to ionize +itself Auto ionization yes absolute + + align:start position:0% +itself Auto ionization yes absolute + + + align:start position:0% +itself Auto ionization yes absolute +favorite it's + + align:start position:0% + + + + align:start position:0% + +crazy okay good stuff so now let's go + + align:start position:0% +crazy okay good stuff so now let's go + + + align:start position:0% +crazy okay good stuff so now let's go +through some equilibria most of which do + + align:start position:0% +through some equilibria most of which do + + + align:start position:0% +through some equilibria most of which do +not involve Auto + + align:start position:0% + + + + align:start position:0% + +ionization and the reference for all of + + align:start position:0% +ionization and the reference for all of + + + align:start position:0% +ionization and the reference for all of +this um there are many textbooks on + + align:start position:0% +this um there are many textbooks on + + + align:start position:0% +this um there are many textbooks on +plasma spectroscopy a very famous + + align:start position:0% +plasma spectroscopy a very famous + + + align:start position:0% +plasma spectroscopy a very famous +textbook is green that's the name of the + + align:start position:0% +textbook is green that's the name of the + + + align:start position:0% +textbook is green that's the name of the +orer and the title of the book is plasma + + align:start position:0% +orer and the title of the book is plasma + + + align:start position:0% +orer and the title of the book is plasma +spectroscopy gream is not actually a + + align:start position:0% +spectroscopy gream is not actually a + + + align:start position:0% +spectroscopy gream is not actually a +particularly good book for learning + + align:start position:0% +particularly good book for learning + + + align:start position:0% +particularly good book for learning +spectroscopy it's a pretty good + + align:start position:0% +spectroscopy it's a pretty good + + + align:start position:0% +spectroscopy it's a pretty good +reference uh but you will find all this + + align:start position:0% +reference uh but you will find all this + + + align:start position:0% +reference uh but you will find all this +stuff in here if you want to know more + + align:start position:0% +stuff in here if you want to know more + + + align:start position:0% +stuff in here if you want to know more +Hutchinson has some of it uh in a + + align:start position:0% +Hutchinson has some of it uh in a + + + align:start position:0% +Hutchinson has some of it uh in a +slightly more fragmented fashion so I've + + align:start position:0% +slightly more fragmented fashion so I've + + + align:start position:0% +slightly more fragmented fashion so I've +been taking most of this from + + align:start position:0% +been taking most of this from + + + align:start position:0% +been taking most of this from +Green so the most simple + + align:start position:0% +Green so the most simple + + + align:start position:0% +Green so the most simple +equilibrium is an equilibrium where + + align:start position:0% +equilibrium is an equilibrium where + + + align:start position:0% +equilibrium is an equilibrium where +we're in complete thermodynamic + + align:start position:0% + + + + align:start position:0% + +equilibrium if we're we're in a + + align:start position:0% +equilibrium if we're we're in a + + + align:start position:0% +equilibrium if we're we're in a +thermodynamic equilibrium this implies + + align:start position:0% +thermodynamic equilibrium this implies + + + align:start position:0% +thermodynamic equilibrium this implies +straight away that we have a boltzman + + align:start position:0% +straight away that we have a boltzman + + + align:start position:0% +straight away that we have a boltzman +occupation of + + align:start position:0% + + + + align:start position:0% + +States so our boltzman occupation of + + align:start position:0% +States so our boltzman occupation of + + + align:start position:0% +States so our boltzman occupation of +states is something like the occupation + + align:start position:0% +states is something like the occupation + + + align:start position:0% +states is something like the occupation +of the I State whether that's an + + align:start position:0% +of the I State whether that's an + + + align:start position:0% +of the I State whether that's an +ionization state or it's an excited + + align:start position:0% +ionization state or it's an excited + + + align:start position:0% +ionization state or it's an excited +state within an ion is proportional to + + align:start position:0% +state within an ion is proportional to + + + align:start position:0% +state within an ion is proportional to +exponential of minus the energy of that + + align:start position:0% +exponential of minus the energy of that + + + align:start position:0% +exponential of minus the energy of that +state over the temperature and the + + align:start position:0% +state over the temperature and the + + + align:start position:0% +state over the temperature and the +electrons and the ions and the radiation + + align:start position:0% +electrons and the ions and the radiation + + + align:start position:0% +electrons and the ions and the radiation +all share the same temperature so there + + align:start position:0% +all share the same temperature so there + + + align:start position:0% +all share the same temperature so there +is + + align:start position:0% +is + + + align:start position:0% +is +only one temperature for the electrons + + align:start position:0% +only one temperature for the electrons + + + align:start position:0% +only one temperature for the electrons +the ions and the + + align:start position:0% + + + + align:start position:0% + +photons the other thing about a + + align:start position:0% +photons the other thing about a + + + align:start position:0% +photons the other thing about a +thermodynamic equilibrium is that all + + align:start position:0% +thermodynamic equilibrium is that all + + + align:start position:0% +thermodynamic equilibrium is that all +the processes + + align:start position:0% + + + + align:start position:0% + +balanced so all of the up processes that + + align:start position:0% +balanced so all of the up processes that + + + align:start position:0% +balanced so all of the up processes that +excite the system are exactly balanced + + align:start position:0% +excite the system are exactly balanced + + + align:start position:0% +excite the system are exactly balanced +by their counterparts that de excites + + align:start position:0% +by their counterparts that de excites + + + align:start position:0% +by their counterparts that de excites +the system so this is how we get into a + + align:start position:0% +the system so this is how we get into a + + + align:start position:0% +the system so this is how we get into a +steady state here that's actually not + + align:start position:0% +steady state here that's actually not + + + align:start position:0% +steady state here that's actually not +true in other equilibria there can be + + align:start position:0% +true in other equilibria there can be + + + align:start position:0% +true in other equilibria there can be +processes which excite and different + + align:start position:0% +processes which excite and different + + + align:start position:0% +processes which excite and different +processes that de exite as long as the + + align:start position:0% +processes that de exite as long as the + + + align:start position:0% +processes that de exite as long as the +rate is the same you're in an + + align:start position:0% +rate is the same you're in an + + + align:start position:0% +rate is the same you're in an +equilibrium and we'll talk about some of + + align:start position:0% +equilibrium and we'll talk about some of + + + align:start position:0% +equilibrium and we'll talk about some of +those uh later on but for thermodynamic + + align:start position:0% +those uh later on but for thermodynamic + + + align:start position:0% +those uh later on but for thermodynamic +equilibrium all processes balance with + + align:start position:0% +equilibrium all processes balance with + + + align:start position:0% +equilibrium all processes balance with +their opposite + + align:start position:0% + + + + align:start position:0% + +process + + align:start position:0% +process + + + align:start position:0% +process +okay now how often do we think we get a + + align:start position:0% +okay now how often do we think we get a + + + align:start position:0% +okay now how often do we think we get a +thermodynamic equilibrium in a + + align:start position:0% + + + + align:start position:0% + +plasma maybe in space probably getting + + align:start position:0% +plasma maybe in space probably getting + + + align:start position:0% +plasma maybe in space probably getting +closer I mean a thermodynamic + + align:start position:0% +closer I mean a thermodynamic + + + align:start position:0% +closer I mean a thermodynamic +equilibrium is an infinite in uh system + + align:start position:0% +equilibrium is an infinite in uh system + + + align:start position:0% +equilibrium is an infinite in uh system +which is not changing in time so of + + align:start position:0% +which is not changing in time so of + + + align:start position:0% +which is not changing in time so of +course in reality we can never realize + + align:start position:0% +course in reality we can never realize + + + align:start position:0% +course in reality we can never realize +it the space plasma you might get close + + align:start position:0% +it the space plasma you might get close + + + align:start position:0% +it the space plasma you might get close +to thermodynamic equilibrium um but this + + align:start position:0% +to thermodynamic equilibrium um but this + + + align:start position:0% +to thermodynamic equilibrium um but this +also implies that you have to have your + + align:start position:0% +also implies that you have to have your + + + align:start position:0% +also implies that you have to have your +photons in Thal equilibrium with your + + align:start position:0% +photons in Thal equilibrium with your + + + align:start position:0% +photons in Thal equilibrium with your +gas which means that your system is + + align:start position:0% +gas which means that your system is + + + align:start position:0% +gas which means that your system is +optically thick and space plasmas at + + align:start position:0% +optically thick and space plasmas at + + + align:start position:0% +optically thick and space plasmas at +least Plasma in space in outter space is + + align:start position:0% +least Plasma in space in outter space is + + + align:start position:0% +least Plasma in space in outter space is +rarely optically thick maybe inside some + + align:start position:0% +rarely optically thick maybe inside some + + + align:start position:0% +rarely optically thick maybe inside some +astrophysical body it could be optically + + align:start position:0% +astrophysical body it could be optically + + + align:start position:0% +astrophysical body it could be optically +thick so this we don't really H get very + + align:start position:0% +thick so this we don't really H get very + + + align:start position:0% +thick so this we don't really H get very +often so this uh is + + align:start position:0% + + + + align:start position:0% + +rare okay next one I want to talk about + + align:start position:0% +rare okay next one I want to talk about + + + align:start position:0% +rare okay next one I want to talk about +is + + align:start position:0% + + + + align:start position:0% + +local thermodynamic + + align:start position:0% +local thermodynamic + + + align:start position:0% +local thermodynamic +equilibrium I'll write as local te so + + align:start position:0% +equilibrium I'll write as local te so + + + align:start position:0% +equilibrium I'll write as local te so +people will often call this + + align:start position:0% +people will often call this + + + align:start position:0% +people will often call this +LT like this okay now in local + + align:start position:0% +LT like this okay now in local + + + align:start position:0% +LT like this okay now in local +thermodynamic equilibrium we make the + + align:start position:0% +thermodynamic equilibrium we make the + + + align:start position:0% +thermodynamic equilibrium we make the +assumption that our plasma is optically + + align:start position:0% + + + + align:start position:0% + +thin which means that we can ignore the + + align:start position:0% +thin which means that we can ignore the + + + align:start position:0% +thin which means that we can ignore the +processes that involve photons being + + align:start position:0% +processes that involve photons being + + + align:start position:0% +processes that involve photons being +absorbed and emitted in terms of + + align:start position:0% +absorbed and emitted in terms of + + + align:start position:0% +absorbed and emitted in terms of +changing the levels so you think no I + + align:start position:0% +changing the levels so you think no I + + + align:start position:0% +changing the levels so you think no I +guess I'll call it radi + + align:start position:0% + + + + align:start position:0% + +processes the rad processes still occur + + align:start position:0% +processes the rad processes still occur + + + align:start position:0% +processes the rad processes still occur +we can still observe the lines coming + + align:start position:0% +we can still observe the lines coming + + + align:start position:0% +we can still observe the lines coming +from them and do spectroscopy on them + + align:start position:0% +from them and do spectroscopy on them + + + align:start position:0% +from them and do spectroscopy on them +but they don't dominate the balance of + + align:start position:0% +but they don't dominate the balance of + + + align:start position:0% +but they don't dominate the balance of +the uh ex you know what determined what + + align:start position:0% +the uh ex you know what determined what + + + align:start position:0% +the uh ex you know what determined what +states are excited what are iron in fact + + align:start position:0% +states are excited what are iron in fact + + + align:start position:0% +states are excited what are iron in fact +that balance is then obviously dominated + + align:start position:0% +that balance is then obviously dominated + + + align:start position:0% +that balance is then obviously dominated +by the non- rative process so these are + + align:start position:0% +by the non- rative process so these are + + + align:start position:0% +by the non- rative process so these are +collisional + + align:start position:0% + + + + align:start position:0% + +processes the collisional processes + + align:start position:0% +processes the collisional processes + + + align:start position:0% +processes the collisional processes +dominate + + align:start position:0% + + + + align:start position:0% + +here so this is collisional processes + + align:start position:0% +here so this is collisional processes + + + align:start position:0% +here so this is collisional processes +which excite from a lower state to an + + align:start position:0% +which excite from a lower state to an + + + align:start position:0% +which excite from a lower state to an +upper state but also collisional + + align:start position:0% +upper state but also collisional + + + align:start position:0% +upper state but also collisional +processes which de exite from the Upper + + align:start position:0% +processes which de exite from the Upper + + + align:start position:0% +processes which de exite from the Upper +State back down to the Lower State so + + align:start position:0% +State back down to the Lower State so + + + align:start position:0% +State back down to the Lower State so +our occupation of the upper and lower + + align:start position:0% +our occupation of the upper and lower + + + align:start position:0% +our occupation of the upper and lower +States is set purely by these + + align:start position:0% +States is set purely by these + + + align:start position:0% +States is set purely by these +collisional + + align:start position:0% +collisional + + + align:start position:0% +collisional +processes however we don't need to + + align:start position:0% +processes however we don't need to + + + align:start position:0% +processes however we don't need to +know the cross-section for these + + align:start position:0% +know the cross-section for these + + + align:start position:0% +know the cross-section for these +processes which we would do in our more + + align:start position:0% +processes which we would do in our more + + + align:start position:0% +processes which we would do in our more +detailed full model remember this Sigma + + align:start position:0% +detailed full model remember this Sigma + + + align:start position:0% +detailed full model remember this Sigma +i j is the cross-section for a process + + align:start position:0% +i j is the cross-section for a process + + + align:start position:0% +i j is the cross-section for a process +that takes us from State I to State J + + align:start position:0% +that takes us from State I to State J + + + align:start position:0% +that takes us from State I to State J +but they're unimportant in + + align:start position:0% + + + + align:start position:0% + +LTE due to the balance so we keep the + + align:start position:0% +LTE due to the balance so we keep the + + + align:start position:0% +LTE due to the balance so we keep the +feature of a thermodynamic equilibrium + + align:start position:0% +feature of a thermodynamic equilibrium + + + align:start position:0% +feature of a thermodynamic equilibrium +that the process is a balance of the + + align:start position:0% +that the process is a balance of the + + + align:start position:0% +that the process is a balance of the +opposite process so the actual + + align:start position:0% +opposite process so the actual + + + align:start position:0% +opposite process so the actual +cross-section processes un + + align:start position:0% +cross-section processes un + + + align:start position:0% +cross-section processes un +important and that's what makes it a + + align:start position:0% +important and that's what makes it a + + + align:start position:0% +important and that's what makes it a +local thermodynamic + + align:start position:0% + + + + align:start position:0% + +equilibri and if + + align:start position:0% +equilibri and if + + + align:start position:0% +equilibri and if +you look at what this means and you work + + align:start position:0% +you look at what this means and you work + + + align:start position:0% +you look at what this means and you work +through the mathematics of + + align:start position:0% +through the mathematics of + + + align:start position:0% +through the mathematics of +your population balance you come up with + + align:start position:0% +your population balance you come up with + + + align:start position:0% +your population balance you come up with +the famous Saha equilibrium so a Saha + + align:start position:0% +the famous Saha equilibrium so a Saha + + + align:start position:0% +the famous Saha equilibrium so a Saha +equilibrium named after its discoverer + + align:start position:0% + + + + align:start position:0% + +has a form that says that the electron + + align:start position:0% +has a form that says that the electron + + + align:start position:0% +has a form that says that the electron +density times the + + align:start position:0% +density times the + + + align:start position:0% +density times the +ionization density for State Zed in its + + align:start position:0% +ionization density for State Zed in its + + + align:start position:0% +ionization density for State Zed in its +ground state over Zed minus one in its + + align:start position:0% +ground state over Zed minus one in its + + + align:start position:0% +ground state over Zed minus one in its +ground state so this is the density of + + align:start position:0% +ground state so this is the density of + + + align:start position:0% +ground state so this is the density of +atoms in ionization State Zed and their + + align:start position:0% +atoms in ionization State Zed and their + + + align:start position:0% +atoms in ionization State Zed and their +ground state atoms in ionization State Z + + align:start position:0% +ground state atoms in ionization State Z + + + align:start position:0% +ground state atoms in ionization State Z +minus one in their ground state Times by + + align:start position:0% +minus one in their ground state Times by + + + align:start position:0% +minus one in their ground state Times by +the electron density is + + align:start position:0% +the electron density is + + + align:start position:0% +the electron density is +equal to most + + align:start position:0% +equal to most + + + align:start position:0% +equal to most +importantly a factor to do with the + + align:start position:0% +importantly a factor to do with the + + + align:start position:0% +importantly a factor to do with the +ionization + + align:start position:0% +ionization + + + align:start position:0% +ionization +potential so this Kai Z here is the + + align:start position:0% +potential so this Kai Z here is the + + + align:start position:0% +potential so this Kai Z here is the +ionization to go from uh Zed minus one + + align:start position:0% +ionization to go from uh Zed minus one + + + align:start position:0% +ionization to go from uh Zed minus one +to + + align:start position:0% + + + + align:start position:0% + +zed the change in energy there over the + + align:start position:0% +zed the change in energy there over the + + + align:start position:0% +zed the change in energy there over the +temperature and then there's a few other + + align:start position:0% +temperature and then there's a few other + + + align:start position:0% +temperature and then there's a few other +factors out front that come from the + + align:start position:0% +factors out front that come from the + + + align:start position:0% +factors out front that come from the +fact that we're going to be assuming l + + align:start position:0% +fact that we're going to be assuming l + + + align:start position:0% +fact that we're going to be assuming l +ations are maxwellian there's an ion + + align:start position:0% +ations are maxwellian there's an ion + + + align:start position:0% +ations are maxwellian there's an ion +Mass temperature over 2 pi H bar squared + + align:start position:0% +Mass temperature over 2 pi H bar squared + + + align:start position:0% +Mass temperature over 2 pi H bar squared +with three halves and then there's also + + align:start position:0% +with three halves and then there's also + + + align:start position:0% +with three halves and then there's also +a factor that's to do with the + + align:start position:0% +a factor that's to do with the + + + align:start position:0% +a factor that's to do with the +degeneracy of these levels and we talked + + align:start position:0% +degeneracy of these levels and we talked + + + align:start position:0% +degeneracy of these levels and we talked +about the degeneracy as being different + + align:start position:0% +about the degeneracy as being different + + + align:start position:0% +about the degeneracy as being different +ways to arrange electrons and still get + + align:start position:0% +ways to arrange electrons and still get + + + align:start position:0% +ways to arrange electrons and still get +out the same uh energy so this is g z + + align:start position:0% +out the same uh energy so this is g z + + + align:start position:0% +out the same uh energy so this is g z +for the Zer ionization State one over + + align:start position:0% +for the Zer ionization State one over + + + align:start position:0% +for the Zer ionization State one over +the degeneracy of the lower ionization + + align:start position:0% +the degeneracy of the lower ionization + + + align:start position:0% +the degeneracy of the lower ionization +state so the sah equilibrium doesn't + + align:start position:0% +state so the sah equilibrium doesn't + + + align:start position:0% +state so the sah equilibrium doesn't +tell you about how the excitation states + + align:start position:0% +tell you about how the excitation states + + + align:start position:0% +tell you about how the excitation states +are distributed within each ion but it + + align:start position:0% +are distributed within each ion but it + + + align:start position:0% +are distributed within each ion but it +does tell you what the ionization is and + + align:start position:0% +does tell you what the ionization is and + + + align:start position:0% +does tell you what the ionization is and +so this tells you for a given + + align:start position:0% +so this tells you for a given + + + align:start position:0% +so this tells you for a given +temperature how many particles you + + align:start position:0% +temperature how many particles you + + + align:start position:0% +temperature how many particles you +expect to be in each ionization State + + align:start position:0% +expect to be in each ionization State + + + align:start position:0% +expect to be in each ionization State +and because of this exponential Factor + + align:start position:0% +and because of this exponential Factor + + + align:start position:0% +and because of this exponential Factor +here which comes from a sort of Bolton + + align:start position:0% +here which comes from a sort of Bolton + + + align:start position:0% +here which comes from a sort of Bolton +like argument we're going to end up with + + align:start position:0% +like argument we're going to end up with + + + align:start position:0% +like argument we're going to end up with +most of our particles still being in + + align:start position:0% +most of our particles still being in + + + align:start position:0% +most of our particles still being in +lower ionization + + align:start position:0% +lower ionization + + + align:start position:0% +lower ionization +States okay any questions so far yeah + + align:start position:0% + + + + align:start position:0% + +the radiation doesn't have to be the + + align:start position:0% +the radiation doesn't have to be the + + + align:start position:0% +the radiation doesn't have to be the +same because we it's optically thin and + + align:start position:0% +same because we it's optically thin and + + + align:start position:0% +same because we it's optically thin and +we don't care about it but the ions and + + align:start position:0% +we don't care about it but the ions and + + + align:start position:0% +we don't care about it but the ions and +the electrons are the same temperature + + align:start position:0% + + + + align:start position:0% + +yes yeah so this notation here this uh + + align:start position:0% +yes yeah so this notation here this uh + + + align:start position:0% +yes yeah so this notation here this uh +lower number here is like if you have a + + align:start position:0% +lower number here is like if you have a + + + align:start position:0% +lower number here is like if you have a +series of levels within an atom that + + align:start position:0% +series of levels within an atom that + + + align:start position:0% +series of levels within an atom that +atom has a charge of plus Zed and then + + align:start position:0% +atom has a charge of plus Zed and then + + + align:start position:0% +atom has a charge of plus Zed and then +I've got these levels which I could + + align:start position:0% +I've got these levels which I could + + + align:start position:0% +I've got these levels which I could +label one two three four and so on like + + align:start position:0% +label one two three four and so on like + + + align:start position:0% +label one two three four and so on like +that this one refers to the energy level + + align:start position:0% +that this one refers to the energy level + + + align:start position:0% +that this one refers to the energy level +with an atom with charge plus Zed and + + align:start position:0% +with an atom with charge plus Zed and + + + align:start position:0% +with an atom with charge plus Zed and +the Zed here refers to that charge so + + align:start position:0% +the Zed here refers to that charge so + + + align:start position:0% +the Zed here refers to that charge so +these are atoms with different + + align:start position:0% +these are atoms with different + + + align:start position:0% +these are atoms with different +ionization states which means in general + + align:start position:0% +ionization states which means in general + + + align:start position:0% +ionization states which means in general +their energy levels will have different + + align:start position:0% +their energy levels will have different + + + align:start position:0% +their energy levels will have different +energies but here we're taking the ratio + + align:start position:0% +energies but here we're taking the ratio + + + align:start position:0% +energies but here we're taking the ratio +of the atoms of ionization State Zed in + + align:start position:0% +of the atoms of ionization State Zed in + + + align:start position:0% +of the atoms of ionization State Zed in +the ground state level one and the atoms + + align:start position:0% +the ground state level one and the atoms + + + align:start position:0% +the ground state level one and the atoms +of ionization State Zed minus one so + + align:start position:0% +of ionization State Zed minus one so + + + align:start position:0% +of ionization State Zed minus one so +they have one more electron and they're + + align:start position:0% +they have one more electron and they're + + + align:start position:0% +they have one more electron and they're +in their ground state one and the energy + + align:start position:0% +in their ground state one and the energy + + + align:start position:0% +in their ground state one and the energy +of that ground state will not in general + + align:start position:0% +of that ground state will not in general + + + align:start position:0% +of that ground state will not in general +be the same as the energy of the ion + + align:start position:0% +be the same as the energy of the ion + + + align:start position:0% +be the same as the energy of the ion +with one fewer electron because all the + + align:start position:0% +with one fewer electron because all the + + + align:start position:0% +with one fewer electron because all the +energy levels will shift when we reduce + + align:start position:0% +energy levels will shift when we reduce + + + align:start position:0% +energy levels will shift when we reduce +the number of + + align:start position:0% + + + + align:start position:0% + +electrons + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% + + + + align:start position:0% + +uh yes yeah but you you could you could + + align:start position:0% +uh yes yeah but you you could you could + + + align:start position:0% +uh yes yeah but you you could you could +skip that by just taking ratios of this + + align:start position:0% +skip that by just taking ratios of this + + + align:start position:0% +skip that by just taking ratios of this +equation with unionized argon and then + + align:start position:0% +equation with unionized argon and then + + + align:start position:0% +equation with unionized argon and then +you get out the ionization to get to + + align:start position:0% +you get out the ionization to get to + + + align:start position:0% +you get out the ionization to get to +like the fifth ionization level so you + + align:start position:0% +like the fifth ionization level so you + + + align:start position:0% +like the fifth ionization level so you +don't actually have to do it with do it + + align:start position:0% +don't actually have to do it with do it + + + align:start position:0% +don't actually have to do it with do it +all in one you could also do it that way + + align:start position:0% +all in one you could also do it that way + + + align:start position:0% +all in one you could also do it that way +if you wanted but yeah in general these + + align:start position:0% +if you wanted but yeah in general these + + + align:start position:0% +if you wanted but yeah in general these +ionization potentials are tabulated + + align:start position:0% +ionization potentials are tabulated + + + align:start position:0% +ionization potentials are tabulated +there things that people know from an + + align:start position:0% +there things that people know from an + + + align:start position:0% +there things that people know from an +experiment you know it's 13.6 electron + + align:start position:0% +experiment you know it's 13.6 electron + + + align:start position:0% +experiment you know it's 13.6 electron +volts for hydrogen it's less for every + + align:start position:0% +volts for hydrogen it's less for every + + + align:start position:0% +volts for hydrogen it's less for every +subsequent uh element and so you need to + + align:start position:0% +subsequent uh element and so you need to + + + align:start position:0% +subsequent uh element and so you need to +put in the temperature of course of your + + align:start position:0% +put in the temperature of course of your + + + align:start position:0% +put in the temperature of course of your +plasma but then you can calculate this + + align:start position:0% +plasma but then you can calculate this + + + align:start position:0% +plasma but then you can calculate this +pretty quickly so this is a nice and + + align:start position:0% +pretty quickly so this is a nice and + + + align:start position:0% +pretty quickly so this is a nice and +simple relatively simple equilibria and + + align:start position:0% +simple relatively simple equilibria and + + + align:start position:0% +simple relatively simple equilibria and +so you know for example if you're doing + + align:start position:0% +so you know for example if you're doing + + + align:start position:0% +so you know for example if you're doing +spectroscopy and you see a line which + + align:start position:0% +spectroscopy and you see a line which + + + align:start position:0% +spectroscopy and you see a line which +has an energy which corresponds to The + + align:start position:0% +has an energy which corresponds to The + + + align:start position:0% +has an energy which corresponds to The +Zed ionization State you know you see a + + align:start position:0% +Zed ionization State you know you see a + + + align:start position:0% +Zed ionization State you know you see a +line that you know corresponds to argon + + align:start position:0% +line that you know corresponds to argon + + + align:start position:0% +line that you know corresponds to argon +5 plus then you know you have to be at + + align:start position:0% +5 plus then you know you have to be at + + + align:start position:0% +5 plus then you know you have to be at +at least the temperature that produces + + align:start position:0% +at least the temperature that produces + + + align:start position:0% +at least the temperature that produces +argon 5 plus you can't be at a + + align:start position:0% +argon 5 plus you can't be at a + + + align:start position:0% +argon 5 plus you can't be at a +temperature where argon is completely + + align:start position:0% +temperature where argon is completely + + + align:start position:0% +temperature where argon is completely +neutral or only singly ionized so + + align:start position:0% +neutral or only singly ionized so + + + align:start position:0% +neutral or only singly ionized so +straight away this sort of equilibrium + + align:start position:0% +straight away this sort of equilibrium + + + align:start position:0% +straight away this sort of equilibrium +is like uh if I see that line it must be + + align:start position:0% +is like uh if I see that line it must be + + + align:start position:0% +is like uh if I see that line it must be +at least this hot and you know that's + + align:start position:0% +at least this hot and you know that's + + + align:start position:0% +at least this hot and you know that's +often good enough for spectroscopy we'll + + align:start position:0% +often good enough for spectroscopy we'll + + + align:start position:0% +often good enough for spectroscopy we'll +talk about more advanced tactics using + + align:start position:0% +talk about more advanced tactics using + + + align:start position:0% +talk about more advanced tactics using +spectroscopy later on okay other + + align:start position:0% +spectroscopy later on okay other + + + align:start position:0% +spectroscopy later on okay other +questions any + + align:start position:0% + + + + align:start position:0% + +online + + align:start position:0% +online + + + align:start position:0% +online +okay next equilibrium + + align:start position:0% + + + + align:start position:0% + +is something called coronal + + align:start position:0% +is something called coronal + + + align:start position:0% +is something called coronal +equilibrium + + align:start position:0% + + + + align:start position:0% + +coronal equilibrium is called coronal + + align:start position:0% +coronal equilibrium is called coronal + + + align:start position:0% +coronal equilibrium is called coronal +because it was first derived in the case + + align:start position:0% +because it was first derived in the case + + + align:start position:0% +because it was first derived in the case +of the solar + + align:start position:0% + + + + align:start position:0% + +Corona sometimes this is also called a + + align:start position:0% +Corona sometimes this is also called a + + + align:start position:0% +Corona sometimes this is also called a +collisional radiative + + align:start position:0% + + + + align:start position:0% + +equilibrium and that name radiative is + + align:start position:0% +equilibrium and that name radiative is + + + align:start position:0% +equilibrium and that name radiative is +much more descriptive and I wish we used + + align:start position:0% +much more descriptive and I wish we used + + + align:start position:0% +much more descriptive and I wish we used +it more but you'll still find most + + align:start position:0% +it more but you'll still find most + + + align:start position:0% +it more but you'll still find most +people calling it coronal equilibrium + + align:start position:0% +people calling it coronal equilibrium + + + align:start position:0% +people calling it coronal equilibrium +instead so it's called a collisional + + align:start position:0% +instead so it's called a collisional + + + align:start position:0% +instead so it's called a collisional +radiative equilibrium because we + + align:start position:0% +radiative equilibrium because we + + + align:start position:0% +radiative equilibrium because we +consider the + + align:start position:0% +consider the + + + align:start position:0% +consider the +excitation going from a lower state to + + align:start position:0% +excitation going from a lower state to + + + align:start position:0% +excitation going from a lower state to +an upper state only collisional + + align:start position:0% + + + + align:start position:0% + +processes but for any D exitation going + + align:start position:0% +processes but for any D exitation going + + + align:start position:0% +processes but for any D exitation going +from an upper State back down to a lower + + align:start position:0% +from an upper State back down to a lower + + + align:start position:0% +from an upper State back down to a lower +State we consider only radiative + + align:start position:0% +State we consider only radiative + + + align:start position:0% +State we consider only radiative +process + + align:start position:0% + + + + align:start position:0% + +so this is a a slightly seemingly + + align:start position:0% +so this is a a slightly seemingly + + + align:start position:0% +so this is a a slightly seemingly +contrived setup that actually occurs a + + align:start position:0% +contrived setup that actually occurs a + + + align:start position:0% +contrived setup that actually occurs a +great deal of the time it's a setup in + + align:start position:0% +great deal of the time it's a setup in + + + align:start position:0% +great deal of the time it's a setup in +which our system is optically + + align:start position:0% + + + + align:start position:0% + +thin and so we are very unlikely to have + + align:start position:0% +thin and so we are very unlikely to have + + + align:start position:0% +thin and so we are very unlikely to have +a photon wand by and suddenly excite our + + align:start position:0% +a photon wand by and suddenly excite our + + + align:start position:0% +a photon wand by and suddenly excite our +system because the photons mostly just + + align:start position:0% +system because the photons mostly just + + + align:start position:0% +system because the photons mostly just +stream through the plasma without being + + align:start position:0% +stream through the plasma without being + + + align:start position:0% +stream through the plasma without being +absorbed so this is opop Ean the photons + + align:start position:0% +absorbed so this is opop Ean the photons + + + align:start position:0% +absorbed so this is opop Ean the photons +Escape + + align:start position:0% + + + + align:start position:0% + +and yet it's also so collisionless the + + align:start position:0% +and yet it's also so collisionless the + + + align:start position:0% +and yet it's also so collisionless the +collisions happen so rarely um that + + align:start position:0% +collisions happen so rarely um that + + + align:start position:0% +collisions happen so rarely um that +although they're responsible for + + align:start position:0% +although they're responsible for + + + align:start position:0% +although they're responsible for +excitation before you have chance to + + align:start position:0% +excitation before you have chance to + + + align:start position:0% +excitation before you have chance to +have a collision de exite your system + + align:start position:0% +have a collision de exite your system + + + align:start position:0% +have a collision de exite your system +they will it will spontaneously emit a + + align:start position:0% +they will it will spontaneously emit a + + + align:start position:0% +they will it will spontaneously emit a +photon so that instead we'll have + + align:start position:0% +photon so that instead we'll have + + + align:start position:0% +photon so that instead we'll have +spontaneous emission taking us back + + align:start position:0% + + + + align:start position:0% + +down + + align:start position:0% +down + + + align:start position:0% +down +so this uh + + align:start position:0% +so this uh + + + align:start position:0% +so this uh +works very well for low density + + align:start position:0% + + + + align:start position:0% + +plasmas + + align:start position:0% + + + + align:start position:0% + +yeah yes exactly but and but we're not + + align:start position:0% +yeah yes exactly but and but we're not + + + align:start position:0% +yeah yes exactly but and but we're not +dealing with any rative processes that + + align:start position:0% +dealing with any rative processes that + + + align:start position:0% +dealing with any rative processes that +rely on there being a large number of + + align:start position:0% +rely on there being a large number of + + + align:start position:0% +rely on there being a large number of +photons like stimulated emission those + + align:start position:0% +photons like stimulated emission those + + + align:start position:0% +photons like stimulated emission those +will never happen it's just you know + + align:start position:0% +will never happen it's just you know + + + align:start position:0% +will never happen it's just you know +imagine you've got your Ion floating + + align:start position:0% +imagine you've got your Ion floating + + + align:start position:0% +imagine you've got your Ion floating +around uh lots of photons stream by they + + align:start position:0% +around uh lots of photons stream by they + + + align:start position:0% +around uh lots of photons stream by they +will never interact with it occasionally + + align:start position:0% +will never interact with it occasionally + + + align:start position:0% +will never interact with it occasionally +a collision will happen it excites and + + align:start position:0% +a collision will happen it excites and + + + align:start position:0% +a collision will happen it excites and +so now it's in an excited state then the + + align:start position:0% +so now it's in an excited state then the + + + align:start position:0% +so now it's in an excited state then the +clock is ticking two things could happen + + align:start position:0% +clock is ticking two things could happen + + + align:start position:0% +clock is ticking two things could happen +now another Collision could de exite it + + align:start position:0% +now another Collision could de exite it + + + align:start position:0% +now another Collision could de exite it +and non-radiatively take that energy + + align:start position:0% +and non-radiatively take that energy + + + align:start position:0% +and non-radiatively take that energy +away or spontaneous emission could occur + + align:start position:0% +away or spontaneous emission could occur + + + align:start position:0% +away or spontaneous emission could occur +and we've chosen oh this system works in + + align:start position:0% +and we've chosen oh this system works in + + + align:start position:0% +and we've chosen oh this system works in +a regime where the density is low enough + + align:start position:0% +a regime where the density is low enough + + + align:start position:0% +a regime where the density is low enough +remember these processes the collisional + + align:start position:0% +remember these processes the collisional + + + align:start position:0% +remember these processes the collisional +processes is all depend on density like + + align:start position:0% +processes is all depend on density like + + + align:start position:0% +processes is all depend on density like +that we've chosen a density which is low + + align:start position:0% +that we've chosen a density which is low + + + align:start position:0% +that we've chosen a density which is low +enough that there will never be a second + + align:start position:0% +enough that there will never be a second + + + align:start position:0% +enough that there will never be a second +Collision more quickly than we have + + align:start position:0% +Collision more quickly than we have + + + align:start position:0% +Collision more quickly than we have +spontaneous emission here this this + + align:start position:0% +spontaneous emission here this this + + + align:start position:0% +spontaneous emission here this this +occurs a lot in topmax and other plasmas + + align:start position:0% +occurs a lot in topmax and other plasmas + + + align:start position:0% +occurs a lot in topmax and other plasmas +so this and it's also relatively easy to + + align:start position:0% +so this and it's also relatively easy to + + + align:start position:0% +so this and it's also relatively easy to +solve for so this is a very favorite + + align:start position:0% +solve for so this is a very favorite + + + align:start position:0% +solve for so this is a very favorite +model in plasma + + align:start position:0% +model in plasma + + + align:start position:0% +model in plasma +spectroscopy okay so if you have that we + + align:start position:0% +spectroscopy okay so if you have that we + + + align:start position:0% +spectroscopy okay so if you have that we +can also write + + align:start position:0% +can also write + + + align:start position:0% +can also write +down the occupation of the excited + + align:start position:0% +down the occupation of the excited + + + align:start position:0% +down the occupation of the excited +States so this is some upper excited + + align:start position:0% +States so this is some upper excited + + + align:start position:0% +States so this is some upper excited +state number of atoms in that state + + align:start position:0% +state number of atoms in that state + + + align:start position:0% +state number of atoms in that state +compared to the ground state everything + + align:start position:0% +compared to the ground state everything + + + align:start position:0% +compared to the ground state everything +is being driven back to the ground state + + align:start position:0% +is being driven back to the ground state + + + align:start position:0% +is being driven back to the ground state +by spontaneous emission even if it takes + + align:start position:0% +by spontaneous emission even if it takes + + + align:start position:0% +by spontaneous emission even if it takes +multiple steps you'll eventually get to + + align:start position:0% +multiple steps you'll eventually get to + + + align:start position:0% +multiple steps you'll eventually get to +the ground state and you'll get there + + align:start position:0% +the ground state and you'll get there + + + align:start position:0% +the ground state and you'll get there +long before any Collision occurs so we + + align:start position:0% +long before any Collision occurs so we + + + align:start position:0% +long before any Collision occurs so we +are going to end up mostly in this + + align:start position:0% +are going to end up mostly in this + + + align:start position:0% +are going to end up mostly in this +ground state here and this ratio here is + + align:start position:0% +ground state here and this ratio here is + + + align:start position:0% +ground state here and this ratio here is +going to be equal to number of electrons + + align:start position:0% +going to be equal to number of electrons + + + align:start position:0% +going to be equal to number of electrons +doing the collisions pump it up to an + + align:start position:0% +doing the collisions pump it up to an + + + align:start position:0% +doing the collisions pump it up to an +excited state Times by The cross-section + + align:start position:0% +excited state Times by The cross-section + + + align:start position:0% +excited state Times by The cross-section +to go from the ground state to this + + align:start position:0% +to go from the ground state to this + + + align:start position:0% +to go from the ground state to this +excited + + align:start position:0% +excited + + + align:start position:0% +excited +state average over the velocity so + + align:start position:0% +state average over the velocity so + + + align:start position:0% +state average over the velocity so +that's our standard reaction rate here + + align:start position:0% +that's our standard reaction rate here + + + align:start position:0% +that's our standard reaction rate here +and it's going to be divided by the rate + + align:start position:0% +and it's going to be divided by the rate + + + align:start position:0% +and it's going to be divided by the rate +at which any process takes it from the + + align:start position:0% +at which any process takes it from the + + + align:start position:0% +at which any process takes it from the +Upper State down to the Lower State here + + align:start position:0% +Upper State down to the Lower State here + + + align:start position:0% +Upper State down to the Lower State here +and this could be by a chain of multiple + + align:start position:0% +and this could be by a chain of multiple + + + align:start position:0% +and this could be by a chain of multiple +processes so for example if this is the + + align:start position:0% +processes so for example if this is the + + + align:start position:0% +processes so for example if this is the +Upper State and there's some + + align:start position:0% +Upper State and there's some + + + align:start position:0% +Upper State and there's some +intermediate State and this is the Lower + + align:start position:0% +intermediate State and this is the Lower + + + align:start position:0% +intermediate State and this is the Lower +State we'd have to add up the processes + + align:start position:0% +State we'd have to add up the processes + + + align:start position:0% +State we'd have to add up the processes +that go straight down and the processes + + align:start position:0% +that go straight down and the processes + + + align:start position:0% +that go straight down and the processes +that go via some intermediate and any + + align:start position:0% +that go via some intermediate and any + + + align:start position:0% +that go via some intermediate and any +chain of these processes will happen + + align:start position:0% +chain of these processes will happen + + + align:start position:0% +chain of these processes will happen +more quickly than another quick so this + + align:start position:0% +more quickly than another quick so this + + + align:start position:0% +more quickly than another quick so this +is the the balance uh between these two + + align:start position:0% +is the the balance uh between these two + + + align:start position:0% +is the the balance uh between these two +here and we can write it very easily for + + align:start position:0% +here and we can write it very easily for + + + align:start position:0% +here and we can write it very easily for +this collisional radi + + align:start position:0% +this collisional radi + + + align:start position:0% +this collisional radi +Del but the up processes are no longer + + align:start position:0% +Del but the up processes are no longer + + + align:start position:0% +Del but the up processes are no longer +balanced by the down processes they're + + align:start position:0% +balanced by the down processes they're + + + align:start position:0% +balanced by the down processes they're +completely separate that's a big break + + align:start position:0% +completely separate that's a big break + + + align:start position:0% +completely separate that's a big break +from our local thermodynamic and our + + align:start position:0% +from our local thermodynamic and our + + + align:start position:0% +from our local thermodynamic and our +thermodynamic + + align:start position:0% +thermodynamic + + + align:start position:0% +thermodynamic +equilibria okay questions on + + align:start position:0% + + + + align:start position:0% + +that that won't happen in this case + + align:start position:0% +that that won't happen in this case + + + align:start position:0% +that that won't happen in this case +because by before the second Collision + + align:start position:0% +because by before the second Collision + + + align:start position:0% +because by before the second Collision +happens it will have decayed right + + align:start position:0% +happens it will have decayed right + + + align:start position:0% +happens it will have decayed right +because because we're saying that these + + align:start position:0% +because because we're saying that these + + + align:start position:0% +because because we're saying that these +collisions are so infrequent so you can + + align:start position:0% +collisions are so infrequent so you can + + + align:start position:0% +collisions are so infrequent so you can +yeah really we just have collisions + + align:start position:0% +yeah really we just have collisions + + + align:start position:0% +yeah really we just have collisions +going + + align:start position:0% +going + + + align:start position:0% +going +up if the Collision only took goes up to + + align:start position:0% +up if the Collision only took goes up to + + + align:start position:0% +up if the Collision only took goes up to +here then before a second Collision + + align:start position:0% +here then before a second Collision + + + align:start position:0% +here then before a second Collision +could + + align:start position:0% +could + + + align:start position:0% +could +occur we'd have spontaneous emission and + + align:start position:0% +occur we'd have spontaneous emission and + + + align:start position:0% +occur we'd have spontaneous emission and +Decay if it goes up to here then there + + align:start position:0% +Decay if it goes up to here then there + + + align:start position:0% +Decay if it goes up to here then there +could be multiple Pathways back down + + align:start position:0% + + + + align:start position:0% + +yeah okay + + align:start position:0% + + + + align:start position:0% + +I'm sorry like you + + align:start position:0% + + + + align:start position:0% + +said right so this is one of these + + align:start position:0% +said right so this is one of these + + + align:start position:0% +said right so this is one of these +things like when is this model valid + + align:start position:0% +things like when is this model valid + + + align:start position:0% +things like when is this model valid +right and so then there will be a + + align:start position:0% +right and so then there will be a + + + align:start position:0% +right and so then there will be a +dimensionless parameter which would be + + align:start position:0% +dimensionless parameter which would be + + + align:start position:0% +dimensionless parameter which would be +the ratio of those time scales and You' + + align:start position:0% +the ratio of those time scales and You' + + + align:start position:0% +the ratio of those time scales and You' +like that parameter to be like very + + align:start position:0% +like that parameter to be like very + + + align:start position:0% +like that parameter to be like very +large or very small depending on whether + + align:start position:0% +large or very small depending on whether + + + align:start position:0% +large or very small depending on whether +you write it one way up or the other way + + align:start position:0% +you write it one way up or the other way + + + align:start position:0% +you write it one way up or the other way +up what is very large and very small 10 + + align:start position:0% +up what is very large and very small 10 + + + align:start position:0% +up what is very large and very small 10 +is pretty large number three can + + align:start position:0% +is pretty large number three can + + + align:start position:0% +is pretty large number three can +sometimes be large enough right so if + + align:start position:0% +sometimes be large enough right so if + + + align:start position:0% +sometimes be large enough right so if +you if you're using this model in a + + align:start position:0% +you if you're using this model in a + + + align:start position:0% +you if you're using this model in a +situation where the ratio is only three + + align:start position:0% +situation where the ratio is only three + + + align:start position:0% +situation where the ratio is only three +it will work roughly it won't be + + align:start position:0% +it will work roughly it won't be + + + align:start position:0% +it will work roughly it won't be +completely wrong there'll be a nice + + align:start position:0% +completely wrong there'll be a nice + + + align:start position:0% +completely wrong there'll be a nice +gentle transition from being right to + + align:start position:0% +gentle transition from being right to + + + align:start position:0% +gentle transition from being right to +being wrong and you'll be somewhere in + + align:start position:0% +being wrong and you'll be somewhere in + + + align:start position:0% +being wrong and you'll be somewhere in +the middle there and so a lot of the + + align:start position:0% +the middle there and so a lot of the + + + align:start position:0% +the middle there and so a lot of the +time we will use this model and if you + + align:start position:0% +time we will use this model and if you + + + align:start position:0% +time we will use this model and if you +go and look in Hutchinson's book and not + + align:start position:0% +go and look in Hutchinson's book and not + + + align:start position:0% +go and look in Hutchinson's book and not +covering it in the lecture today there + + align:start position:0% +covering it in the lecture today there + + + align:start position:0% +covering it in the lecture today there +are actually there's a limit to the + + align:start position:0% +are actually there's a limit to the + + + align:start position:0% +are actually there's a limit to the +energy levels for which CR works and so + + align:start position:0% +energy levels for which CR works and so + + + align:start position:0% +energy levels for which CR works and so +we find + + align:start position:0% +we find + + + align:start position:0% +we find +that uh transitions between the lower + + align:start position:0% +that uh transitions between the lower + + + align:start position:0% +that uh transitions between the lower +energy levels tend to be very rapid + + align:start position:0% +energy levels tend to be very rapid + + + align:start position:0% +energy levels tend to be very rapid +they're very favorable because of the + + align:start position:0% +they're very favorable because of the + + + align:start position:0% +they're very favorable because of the +overlap between the upper electron wave + + align:start position:0% +overlap between the upper electron wave + + + align:start position:0% +overlap between the upper electron wave +function and the lower electron wave + + align:start position:0% +function and the lower electron wave + + + align:start position:0% +function and the lower electron wave +functions and so you can actually use + + align:start position:0% +functions and so you can actually use + + + align:start position:0% +functions and so you can actually use +this coronal equilibrium to describe the + + align:start position:0% +this coronal equilibrium to describe the + + + align:start position:0% +this coronal equilibrium to describe the +first n energy levels and then you have + + align:start position:0% +first n energy levels and then you have + + + align:start position:0% +first n energy levels and then you have +to use a different + + align:start position:0% +to use a different + + + align:start position:0% +to use a different +equilibrium like maybe LTE to describe + + align:start position:0% +equilibrium like maybe LTE to describe + + + align:start position:0% +equilibrium like maybe LTE to describe +the upper energy level so you actually + + align:start position:0% +the upper energy level so you actually + + + align:start position:0% +the upper energy level so you actually +have like a transition between Which + + align:start position:0% +have like a transition between Which + + + align:start position:0% +have like a transition between Which +models are valid even within the same + + align:start position:0% +models are valid even within the same + + + align:start position:0% +models are valid even within the same +atom with the same ionization state so + + align:start position:0% +atom with the same ionization state so + + + align:start position:0% +atom with the same ionization state so +this stuff can get complicated um yeah + + align:start position:0% +this stuff can get complicated um yeah + + + align:start position:0% +this stuff can get complicated um yeah +that was probably too much information + + align:start position:0% +that was probably too much information + + + align:start position:0% +that was probably too much information +but still any questions + + align:start position:0% + + + + align:start position:0% + +online okay and then the final thing + + align:start position:0% +online okay and then the final thing + + + align:start position:0% +online okay and then the final thing +after we've done + + align:start position:0% +after we've done + + + align:start position:0% +after we've done +um coronal equilibrium is really + + align:start position:0% +um coronal equilibrium is really + + + align:start position:0% +um coronal equilibrium is really +just having to actually solve those + + align:start position:0% +just having to actually solve those + + + align:start position:0% +just having to actually solve those +equations right so this is what we + + align:start position:0% +equations right so this is what we + + + align:start position:0% +equations right so this is what we +call non local + + align:start position:0% + + + + align:start position:0% + +thermodynamic equilibrium for many years + + align:start position:0% +thermodynamic equilibrium for many years + + + align:start position:0% +thermodynamic equilibrium for many years +I thought there was a hyphen here and + + align:start position:0% +I thought there was a hyphen here and + + + align:start position:0% +I thought there was a hyphen here and +this was non-local thermodynamic + + align:start position:0% +this was non-local thermodynamic + + + align:start position:0% +this was non-local thermodynamic +equilibrium so we have a thermodynamic + + align:start position:0% +equilibrium so we have a thermodynamic + + + align:start position:0% +equilibrium so we have a thermodynamic +equilibrium which mediated nonlocally it + + align:start position:0% +equilibrium which mediated nonlocally it + + + align:start position:0% +equilibrium which mediated nonlocally it +turns out I was wrong this is just not a + + align:start position:0% +turns out I was wrong this is just not a + + + align:start position:0% +turns out I was wrong this is just not a +local thermodynamic equilibrium which is + + align:start position:0% +local thermodynamic equilibrium which is + + + align:start position:0% +local thermodynamic equilibrium which is +a much less descriptive name but is much + + align:start position:0% +a much less descriptive name but is much + + + align:start position:0% +a much less descriptive name but is much +more valid and you'll often see this + + align:start position:0% +more valid and you'll often see this + + + align:start position:0% +more valid and you'll often see this +written as lowercase n + + align:start position:0% +written as lowercase n + + + align:start position:0% +written as lowercase n +LTE so in general you have to solve all + + align:start position:0% +LTE so in general you have to solve all + + + align:start position:0% +LTE so in general you have to solve all +of the different processes exciting and + + align:start position:0% +of the different processes exciting and + + + align:start position:0% +of the different processes exciting and +de exciting but for a specific nlte + + align:start position:0% +de exciting but for a specific nlte + + + align:start position:0% +de exciting but for a specific nlte +model for a specific plasma you're + + align:start position:0% +model for a specific plasma you're + + + align:start position:0% +model for a specific plasma you're +interested in you may still be able to + + align:start position:0% +interested in you may still be able to + + + align:start position:0% +interested in you may still be able to +restrict what those processes are so + + align:start position:0% +restrict what those processes are so + + + align:start position:0% +restrict what those processes are so +what you need to do is actually consider + + align:start position:0% +what you need to do is actually consider + + + align:start position:0% +what you need to do is actually consider +all the relevant + + align:start position:0% +all the relevant + + + align:start position:0% +all the relevant +processes because even in these models + + align:start position:0% +processes because even in these models + + + align:start position:0% +processes because even in these models +other processes are happening it's just + + align:start position:0% +other processes are happening it's just + + + align:start position:0% +other processes are happening it's just +we think the rate is very small and so + + align:start position:0% +we think the rate is very small and so + + + align:start position:0% +we think the rate is very small and so +those processes are not relevant so if + + align:start position:0% +those processes are not relevant so if + + + align:start position:0% +those processes are not relevant so if +you're doing an nlte model you simply + + align:start position:0% +you're doing an nlte model you simply + + + align:start position:0% +you're doing an nlte model you simply +have to think what calculate what + + align:start position:0% +have to think what calculate what + + + align:start position:0% +have to think what calculate what +processes are relevant to what aren't so + + align:start position:0% +processes are relevant to what aren't so + + + align:start position:0% +processes are relevant to what aren't so +I'll give you an example here if we're + + align:start position:0% +I'll give you an example here if we're + + + align:start position:0% +I'll give you an example here if we're +dealing with a photoionized + + align:start position:0% + + + + align:start position:0% + +plasma so this is a for example I've got + + align:start position:0% +plasma so this is a for example I've got + + + align:start position:0% +plasma so this is a for example I've got +a gas + + align:start position:0% +a gas + + + align:start position:0% +a gas +cell chamber filled with gas and I've + + align:start position:0% +cell chamber filled with gas and I've + + + align:start position:0% +cell chamber filled with gas and I've +got Windows on it which are transparent + + align:start position:0% +got Windows on it which are transparent + + + align:start position:0% +got Windows on it which are transparent +to X-rays and I have an x-ray Source + + align:start position:0% +to X-rays and I have an x-ray Source + + + align:start position:0% +to X-rays and I have an x-ray Source +outside those x-rays will stream in and + + align:start position:0% +outside those x-rays will stream in and + + + align:start position:0% +outside those x-rays will stream in and +they will photo ionize the gas the uh + + align:start position:0% +they will photo ionize the gas the uh + + + align:start position:0% +they will photo ionize the gas the uh +photons will be absorbed and we'll have + + align:start position:0% +photons will be absorbed and we'll have + + + align:start position:0% +photons will be absorbed and we'll have +photo + + align:start position:0% +photo + + + align:start position:0% +photo +ionization and then the uh occupation + + align:start position:0% +ionization and then the uh occupation + + + align:start position:0% +ionization and then the uh occupation +levels will be set by those photo + + align:start position:0% +levels will be set by those photo + + + align:start position:0% +levels will be set by those photo +ionization processes we won't have to + + align:start position:0% +ionization processes we won't have to + + + align:start position:0% +ionization processes we won't have to +consider collisional processes because + + align:start position:0% +consider collisional processes because + + + align:start position:0% +consider collisional processes because +the photon field the strength of the + + align:start position:0% +the photon field the strength of the + + + align:start position:0% +the photon field the strength of the +X-ray Drive is so strong that the + + align:start position:0% +X-ray Drive is so strong that the + + + align:start position:0% +X-ray Drive is so strong that the +photons are much more likely to be + + align:start position:0% +photons are much more likely to be + + + align:start position:0% +photons are much more likely to be +involved than any collisions and so for + + align:start position:0% +involved than any collisions and so for + + + align:start position:0% +involved than any collisions and so for +a photon ionized system for example we + + align:start position:0% +a photon ionized system for example we + + + align:start position:0% +a photon ionized system for example we +can neglect collisional + + align:start position:0% +can neglect collisional + + + align:start position:0% +can neglect collisional +process so that reduces the number of + + align:start position:0% +process so that reduces the number of + + + align:start position:0% +process so that reduces the number of +equations that you need to solve uh and + + align:start position:0% +equations that you need to solve uh and + + + align:start position:0% +equations that you need to solve uh and +so you may be able to get away with a + + align:start position:0% +so you may be able to get away with a + + + align:start position:0% +so you may be able to get away with a +smaller set of + + align:start position:0% + + + + align:start position:0% + +equations but if you calculate it and + + align:start position:0% +equations but if you calculate it and + + + align:start position:0% +equations but if you calculate it and +all your processes are roughly equal + + align:start position:0% +all your processes are roughly equal + + + align:start position:0% +all your processes are roughly equal +then you really do have to solve that + + align:start position:0% +then you really do have to solve that + + + align:start position:0% +then you really do have to solve that +big equation I put up on the board last + + align:start position:0% +big equation I put up on the board last + + + align:start position:0% +big equation I put up on the board last +time that was + + align:start position:0% +time that was + + + align:start position:0% +time that was +effectively zero because we're in steady + + align:start position:0% +effectively zero because we're in steady + + + align:start position:0% +effectively zero because we're in steady +state equals the sum over all + + align:start position:0% + + + + align:start position:0% + +processes and as I mentioned people + + align:start position:0% +processes and as I mentioned people + + + align:start position:0% +processes and as I mentioned people +spend their lives writing codes to + + align:start position:0% +spend their lives writing codes to + + + align:start position:0% +spend their lives writing codes to +calculate these coefficients and to + + align:start position:0% +calculate these coefficients and to + + + align:start position:0% +calculate these coefficients and to +solve this balance um and it can get + + align:start position:0% +solve this balance um and it can get + + + align:start position:0% +solve this balance um and it can get +very very messy + + align:start position:0% +very very messy + + + align:start position:0% +very very messy +indeed so that's all I'm really going to + + align:start position:0% +indeed so that's all I'm really going to + + + align:start position:0% +indeed so that's all I'm really going to +say on + + align:start position:0% +say on + + + align:start position:0% +say on +NLP so in general if we're trying to do + + align:start position:0% +NLP so in general if we're trying to do + + + align:start position:0% +NLP so in general if we're trying to do +Spectros + + align:start position:0% + + + + align:start position:0% + +there is a workflow that we might need + + align:start position:0% +there is a workflow that we might need + + + align:start position:0% +there is a workflow that we might need +to do so this is modeling + + align:start position:0% + + + + align:start position:0% + +spectr so first of all we're going to + + align:start position:0% +spectr so first of all we're going to + + + align:start position:0% +spectr so first of all we're going to +model the Spectra from a blob of + + align:start position:0% + + + + align:start position:0% + +plasma little Cube like this it's got + + align:start position:0% +plasma little Cube like this it's got + + + align:start position:0% +plasma little Cube like this it's got +some mass density which is what + + align:start position:0% +some mass density which is what + + + align:start position:0% +some mass density which is what +spectroscopist often work in row and it + + align:start position:0% +spectroscopist often work in row and it + + + align:start position:0% +spectroscopist often work in row and it +has some temperature occasionally your + + align:start position:0% +has some temperature occasionally your + + + align:start position:0% +has some temperature occasionally your +spectroscopists might work in terms of + + align:start position:0% +spectroscopists might work in terms of + + + align:start position:0% +spectroscopists might work in terms of +ion density instead obviously these are + + align:start position:0% +ion density instead obviously these are + + + align:start position:0% +ion density instead obviously these are +same up to the ion Mass + + align:start position:0% +same up to the ion Mass + + + align:start position:0% +same up to the ion Mass +here then you need to determine what + + align:start position:0% +here then you need to determine what + + + align:start position:0% +here then you need to determine what +equilibrium is + + align:start position:0% + + + + align:start position:0% + +appropriate you know this could be a + + align:start position:0% +appropriate you know this could be a + + + align:start position:0% +appropriate you know this could be a +Saha type equilibrium or a collisional + + align:start position:0% +Saha type equilibrium or a collisional + + + align:start position:0% +Saha type equilibrium or a collisional +radiative equilibrium so maybe you know + + align:start position:0% +radiative equilibrium so maybe you know + + + align:start position:0% +radiative equilibrium so maybe you know +this by some back of the envelope + + align:start position:0% +this by some back of the envelope + + + align:start position:0% +this by some back of the envelope +calculations maybe you go through and + + align:start position:0% +calculations maybe you go through and + + + align:start position:0% +calculations maybe you go through and +calculate a load of rates and determine + + align:start position:0% +calculate a load of rates and determine + + + align:start position:0% +calculate a load of rates and determine +what's most important but you have to + + align:start position:0% +what's most important but you have to + + + align:start position:0% +what's most important but you have to +determine what your + + align:start position:0% +determine what your + + + align:start position:0% +determine what your +equilibriums so then you need to + + align:start position:0% +equilibriums so then you need to + + + align:start position:0% +equilibriums so then you need to +calculate the ionization + + align:start position:0% +calculate the ionization + + + align:start position:0% +calculate the ionization +States what ionizations are present in + + align:start position:0% +States what ionizations are present in + + + align:start position:0% +States what ionizations are present in +your system here so these are the + + align:start position:0% +your system here so these are the + + + align:start position:0% +your system here so these are the +density of ions with charge Z all the + + align:start position:0% +density of ions with charge Z all the + + + align:start position:0% +density of ions with charge Z all the +different Zs in some cases you may be + + align:start position:0% +different Zs in some cases you may be + + + align:start position:0% +different Zs in some cases you may be +very weakly ionized you may have a lot + + align:start position:0% +very weakly ionized you may have a lot + + + align:start position:0% +very weakly ionized you may have a lot +of neutrals and you may have just a few + + align:start position:0% +of neutrals and you may have just a few + + + align:start position:0% +of neutrals and you may have just a few +atoms which have an ionization of one in + + align:start position:0% +atoms which have an ionization of one in + + + align:start position:0% +atoms which have an ionization of one in +other cases you may go all the way from + + align:start position:0% +other cases you may go all the way from + + + align:start position:0% +other cases you may go all the way from +neutrals to fully stripped uh for + + align:start position:0% +neutrals to fully stripped uh for + + + align:start position:0% +neutrals to fully stripped uh for +something like tungsten which has 74 + + align:start position:0% +something like tungsten which has 74 + + + align:start position:0% +something like tungsten which has 74 +electrons 76 electrons that's an awful + + align:start position:0% +electrons 76 electrons that's an awful + + + align:start position:0% +electrons 76 electrons that's an awful +lot of energy but you may well be able + + align:start position:0% +lot of energy but you may well be able + + + align:start position:0% +lot of energy but you may well be able +to get through plasma where you've got + + align:start position:0% +to get through plasma where you've got + + + align:start position:0% +to get through plasma where you've got +fly strip P so then you'd have to take + + align:start position:0% +fly strip P so then you'd have to take + + + align:start position:0% +fly strip P so then you'd have to take +into account all the other ionization + + align:start position:0% +into account all the other ionization + + + align:start position:0% +into account all the other ionization +St then you have to calculate the + + align:start position:0% +St then you have to calculate the + + + align:start position:0% +St then you have to calculate the +excited + + align:start position:0% +excited + + + align:start position:0% +excited +States and you have to calculate the + + align:start position:0% +States and you have to calculate the + + + align:start position:0% +States and you have to calculate the +excited States for each NZ so for all NZ + + align:start position:0% +excited States for each NZ so for all NZ + + + align:start position:0% +excited States for each NZ so for all NZ +you need NZ and then whatever the + + align:start position:0% +you need NZ and then whatever the + + + align:start position:0% +you need NZ and then whatever the +excitation + + align:start position:0% +excitation + + + align:start position:0% +excitation +is + + align:start position:0% + + + + align:start position:0% + +okay then you need to calculate the line + + align:start position:0% + + + + align:start position:0% + +strengths these are these + + align:start position:0% +strengths these are these + + + align:start position:0% +strengths these are these +coefficients a i j and you'll remember + + align:start position:0% +coefficients a i j and you'll remember + + + align:start position:0% +coefficients a i j and you'll remember +that these had some hand wavy relevance + + align:start position:0% +that these had some hand wavy relevance + + + align:start position:0% +that these had some hand wavy relevance +to the overlap integral with the dipole + + align:start position:0% +to the overlap integral with the dipole + + + align:start position:0% +to the overlap integral with the dipole +operator between the upper and the Lower + + align:start position:0% +operator between the upper and the Lower + + + align:start position:0% +operator between the upper and the Lower +State but this is a dipole operator + + align:start position:0% +State but this is a dipole operator + + + align:start position:0% +State but this is a dipole operator +which is radiating away a photon of + + align:start position:0% +which is radiating away a photon of + + + align:start position:0% +which is radiating away a photon of +energy H bar Omega i j and that process + + align:start position:0% +energy H bar Omega i j and that process + + + align:start position:0% +energy H bar Omega i j and that process +has some probability to occur and so + + align:start position:0% +has some probability to occur and so + + + align:start position:0% +has some probability to occur and so +this tells you if you how many photons + + align:start position:0% +this tells you if you how many photons + + + align:start position:0% +this tells you if you how many photons +with that energy that you're going to + + align:start position:0% +with that energy that you're going to + + + align:start position:0% +with that energy that you're going to +see and you need to do that for every + + align:start position:0% +see and you need to do that for every + + + align:start position:0% +see and you need to do that for every +transition between + + align:start position:0% +transition between + + + align:start position:0% +transition between +every set of excited States for every + + align:start position:0% +every set of excited States for every + + + align:start position:0% +every set of excited States for every +ion in your system + + align:start position:0% +ion in your system + + + align:start position:0% +ion in your system +okay so this is + + align:start position:0% + + + + align:start position:0% + +hard once you've done that you can now + + align:start position:0% +hard once you've done that you can now + + + align:start position:0% +hard once you've done that you can now +predict the + + align:start position:0% + + + + align:start position:0% + +Spectra this is + + align:start position:0% +Spectra this is + + + align:start position:0% +Spectra this is +predicting the intensity of radiation + + align:start position:0% +predicting the intensity of radiation + + + align:start position:0% +predicting the intensity of radiation +with frequency + + align:start position:0% +with frequency + + + align:start position:0% +with frequency +Omega for the very specific density and + + align:start position:0% +Omega for the very specific density and + + + align:start position:0% +Omega for the very specific density and +temperature that you started out with + + align:start position:0% +temperature that you started out with + + + align:start position:0% +temperature that you started out with +okay now if you're very very + + align:start position:0% +okay now if you're very very + + + align:start position:0% +okay now if you're very very +lucky your system is optically thin so + + align:start position:0% +lucky your system is optically thin so + + + align:start position:0% +lucky your system is optically thin so +tow less than one life is + + align:start position:0% +tow less than one life is + + + align:start position:0% +tow less than one life is +good if to is greater than one now you + + align:start position:0% +good if to is greater than one now you + + + align:start position:0% +good if to is greater than one now you +need to consider uh radiation + + align:start position:0% +need to consider uh radiation + + + align:start position:0% +need to consider uh radiation +transport so the fact that some of the + + align:start position:0% +transport so the fact that some of the + + + align:start position:0% +transport so the fact that some of the +radiation will be absorbed as it moves + + align:start position:0% +radiation will be absorbed as it moves + + + align:start position:0% +radiation will be absorbed as it moves +through your + + align:start position:0% +through your + + + align:start position:0% +through your +plasma and actually for both of these as + + align:start position:0% +plasma and actually for both of these as + + + align:start position:0% +plasma and actually for both of these as +well + + align:start position:0% +well + + + align:start position:0% +well +you'll have to consider things like + + align:start position:0% +you'll have to consider things like + + + align:start position:0% +you'll have to consider things like +Reflections so the fact you've got metal + + align:start position:0% +Reflections so the fact you've got metal + + + align:start position:0% +Reflections so the fact you've got metal +walls on your toac or whatever it is + + align:start position:0% +walls on your toac or whatever it is + + + align:start position:0% +walls on your toac or whatever it is +means that some light going the other + + align:start position:0% +means that some light going the other + + + align:start position:0% +means that some light going the other +way will bounce back got my plasma here + + align:start position:0% +way will bounce back got my plasma here + + + align:start position:0% +way will bounce back got my plasma here +some of the light from this bit of + + align:start position:0% +some of the light from this bit of + + + align:start position:0% +some of the light from this bit of +plasma is going to be emitted this way + + align:start position:0% +plasma is going to be emitted this way + + + align:start position:0% +plasma is going to be emitted this way +and then it will bounce back into your + + align:start position:0% +and then it will bounce back into your + + + align:start position:0% +and then it will bounce back into your +detector and although it's being emitted + + align:start position:0% +detector and although it's being emitted + + + align:start position:0% +detector and although it's being emitted +from here it will look like it's been + + align:start position:0% +from here it will look like it's been + + + align:start position:0% +from here it will look like it's been +emitted along the line of sight hereit + + align:start position:0% +emitted along the line of sight hereit + + + align:start position:0% +emitted along the line of sight hereit +so if you don't take into account the + + align:start position:0% +so if you don't take into account the + + + align:start position:0% +so if you don't take into account the +reflections you will be thinking you've + + align:start position:0% +reflections you will be thinking you've + + + align:start position:0% +reflections you will be thinking you've +got lines from one bit of a plasma where + + align:start position:0% +got lines from one bit of a plasma where + + + align:start position:0% +got lines from one bit of a plasma where +in fact from another bit of a + + align:start position:0% +in fact from another bit of a + + + align:start position:0% +in fact from another bit of a +plasma you'll also need to model the + + align:start position:0% +plasma you'll also need to model the + + + align:start position:0% +plasma you'll also need to model the +response of your + + align:start position:0% +response of your + + + align:start position:0% +response of your +detector so there are no + + align:start position:0% +detector so there are no + + + align:start position:0% +detector so there are no +perfect spectrometers out there and they + + align:start position:0% +perfect spectrometers out there and they + + + align:start position:0% +perfect spectrometers out there and they +in general have a response curve to + + align:start position:0% +in general have a response curve to + + + align:start position:0% +in general have a response curve to +them which is like response as a + + align:start position:0% +them which is like response as a + + + align:start position:0% +them which is like response as a +frequency of Omega they're not flat they + + align:start position:0% +frequency of Omega they're not flat they + + + align:start position:0% +frequency of Omega they're not flat they +treat different frequencies differently + + align:start position:0% +treat different frequencies differently + + + align:start position:0% +treat different frequencies differently +they obsorb you know infrared photons + + align:start position:0% +they obsorb you know infrared photons + + + align:start position:0% +they obsorb you know infrared photons +more than visible + + align:start position:0% +more than visible + + + align:start position:0% +more than visible +photons and then finally you need to + + align:start position:0% +photons and then finally you need to + + + align:start position:0% +photons and then finally you need to +compare this to your experimental + + align:start position:0% + + + + align:start position:0% + +data so for example if you had a + + align:start position:0% + + + + align:start position:0% + +spectrum that + + align:start position:0% +spectrum that + + + align:start position:0% +spectrum that +has two lines in it like that and you've + + align:start position:0% +has two lines in it like that and you've + + + align:start position:0% +has two lines in it like that and you've +done all of this process and you get out + + align:start position:0% +done all of this process and you get out + + + align:start position:0% +done all of this process and you get out +a spectrum that looks like this you have + + align:start position:0% +a spectrum that looks like this you have + + + align:start position:0% +a spectrum that looks like this you have +a choice you can even say it's close + + align:start position:0% +a choice you can even say it's close + + + align:start position:0% +a choice you can even say it's close +enough for today or you iterate and you + + align:start position:0% +enough for today or you iterate and you + + + align:start position:0% +enough for today or you iterate and you +do all of this again right and you pick + + align:start position:0% +do all of this again right and you pick + + + align:start position:0% +do all of this again right and you pick +a new density and temperature and you do + + align:start position:0% +a new density and temperature and you do + + + align:start position:0% +a new density and temperature and you do +some sort of gradient ense type thing + + align:start position:0% +some sort of gradient ense type thing + + + align:start position:0% +some sort of gradient ense type thing +until eventually your modeled Spectra + + align:start position:0% +until eventually your modeled Spectra + + + align:start position:0% +until eventually your modeled Spectra +matches up with your experimental + + align:start position:0% +matches up with your experimental + + + align:start position:0% +matches up with your experimental +Spectra and then you say + + align:start position:0% +Spectra and then you say + + + align:start position:0% +Spectra and then you say +aha now I finally + + align:start position:0% +aha now I finally + + + align:start position:0% +aha now I finally +know the density and temperature of my + + align:start position:0% +know the density and temperature of my + + + align:start position:0% +know the density and temperature of my +class + + align:start position:0% +class + + + align:start position:0% +class +now so it's a fair bit of work to do + + align:start position:0% +now so it's a fair bit of work to do + + + align:start position:0% +now so it's a fair bit of work to do +spectrally + + align:start position:0% + + + + align:start position:0% + +questions yeah + + align:start position:0% + + + + align:start position:0% + +yeah so you can I will show you show you + + align:start position:0% +yeah so you can I will show you show you + + + align:start position:0% +yeah so you can I will show you show you +some tricks to narrow this parameter + + align:start position:0% +some tricks to narrow this parameter + + + align:start position:0% +some tricks to narrow this parameter +space in a moment this is the sort of + + align:start position:0% +space in a moment this is the sort of + + + align:start position:0% +space in a moment this is the sort of +most General case fact I had a page of + + align:start position:0% +most General case fact I had a page of + + + align:start position:0% +most General case fact I had a page of +notes on this and then my iPad hasn't + + align:start position:0% +notes on this and then my iPad hasn't + + + align:start position:0% +notes on this and then my iPad hasn't +updated them but I wrote the word line + + align:start position:0% +updated them but I wrote the word line + + + align:start position:0% +updated them but I wrote the word line +ratios and I'm gonna try and reconstruct + + align:start position:0% +ratios and I'm gonna try and reconstruct + + + align:start position:0% +ratios and I'm gonna try and reconstruct +the memory what exactly I was going to + + align:start position:0% +the memory what exactly I was going to + + + align:start position:0% +the memory what exactly I was going to +say so we'll see how it goes + + align:start position:0% + + + + align:start position:0% + +yes + + align:start position:0% + + + + align:start position:0% + +well other Diagnostics are can be + + align:start position:0% +well other Diagnostics are can be + + + align:start position:0% +well other Diagnostics are can be +expensive they can be limited to certain + + align:start position:0% +expensive they can be limited to certain + + + align:start position:0% +expensive they can be limited to certain +parameter ranges uh if you're doing + + align:start position:0% +parameter ranges uh if you're doing + + + align:start position:0% +parameter ranges uh if you're doing +astrophysics you can't do Thompson + + align:start position:0% +astrophysics you can't do Thompson + + + align:start position:0% +astrophysics you can't do Thompson +scattering on your black ho cor Corona + + align:start position:0% +scattering on your black ho cor Corona + + + align:start position:0% +scattering on your black ho cor Corona +so you have you're stuck with this sort + + align:start position:0% +so you have you're stuck with this sort + + + align:start position:0% +so you have you're stuck with this sort +of thing um spectroscopy does provide + + align:start position:0% +of thing um spectroscopy does provide + + + align:start position:0% +of thing um spectroscopy does provide +extremely detailed information on all of + + align:start position:0% +extremely detailed information on all of + + + align:start position:0% +extremely detailed information on all of +the atomic kinetics this is what people + + align:start position:0% +the atomic kinetics this is what people + + + align:start position:0% +the atomic kinetics this is what people +call this sort of distribution of + + align:start position:0% +call this sort of distribution of + + + align:start position:0% +call this sort of distribution of +different states of the atomic kinetics + + align:start position:0% +different states of the atomic kinetics + + + align:start position:0% +different states of the atomic kinetics +so if you're far from local + + align:start position:0% +so if you're far from local + + + align:start position:0% +so if you're far from local +thermodynamic equilibrium say you're + + align:start position:0% +thermodynamic equilibrium say you're + + + align:start position:0% +thermodynamic equilibrium say you're +looking at fast electrons in a toac the + + align:start position:0% +looking at fast electrons in a toac the + + + align:start position:0% +looking at fast electrons in a toac the +uh Spectra May provide information on + + align:start position:0% +uh Spectra May provide information on + + + align:start position:0% +uh Spectra May provide information on +those fast electrons that something like + + align:start position:0% +those fast electrons that something like + + + align:start position:0% +those fast electrons that something like +Thomson scattering doesn't because + + align:start position:0% +Thomson scattering doesn't because + + + align:start position:0% +Thomson scattering doesn't because +Thompson scattering maybe as sensitive + + align:start position:0% +Thompson scattering maybe as sensitive + + + align:start position:0% +Thompson scattering maybe as sensitive +just to the bulk of the plasma so you + + align:start position:0% +just to the bulk of the plasma so you + + + align:start position:0% +just to the bulk of the plasma so you +know this is a time honored time honored + + align:start position:0% +know this is a time honored time honored + + + align:start position:0% +know this is a time honored time honored +diagnostic we have a lot of knowledge + + align:start position:0% +diagnostic we have a lot of knowledge + + + align:start position:0% +diagnostic we have a lot of knowledge +about how to do it h it's just that it + + align:start position:0% +about how to do it h it's just that it + + + align:start position:0% +about how to do it h it's just that it +turns out to be very hard I'm sort of + + align:start position:0% +turns out to be very hard I'm sort of + + + align:start position:0% +turns out to be very hard I'm sort of +presented this in a slightly flippant + + align:start position:0% +presented this in a slightly flippant + + + align:start position:0% +presented this in a slightly flippant +way but this is what you need to do you + + align:start position:0% +way but this is what you need to do you + + + align:start position:0% +way but this is what you need to do you +actually want to solve all these things + + align:start position:0% +actually want to solve all these things + + + align:start position:0% +actually want to solve all these things +some of these steps have already been + + align:start position:0% +some of these steps have already been + + + align:start position:0% +some of these steps have already been +done for you right I mean a lot of this + + align:start position:0% +done for you right I mean a lot of this + + + align:start position:0% +done for you right I mean a lot of this +is now included in computer Packaging + + align:start position:0% +is now included in computer Packaging + + + align:start position:0% +is now included in computer Packaging +and so if you know what your equilibrium + + align:start position:0% +and so if you know what your equilibrium + + + align:start position:0% +and so if you know what your equilibrium +is um for example here this row T + + align:start position:0% +is um for example here this row T + + + align:start position:0% +is um for example here this row T +getting out some Spectra here there are + + align:start position:0% +getting out some Spectra here there are + + + align:start position:0% +getting out some Spectra here there are +large codes prism spec is a commercially + + align:start position:0% +large codes prism spec is a commercially + + + align:start position:0% +large codes prism spec is a commercially +available code you give it a density at + + align:start position:0% +available code you give it a density at + + + align:start position:0% +available code you give it a density at +a temperature and it will and the size + + align:start position:0% +a temperature and it will and the size + + + align:start position:0% +a temperature and it will and the size +of your plasma and it will do radiation + + align:start position:0% +of your plasma and it will do radiation + + + align:start position:0% +of your plasma and it will do radiation +transport through it and tell you what + + align:start position:0% +transport through it and tell you what + + + align:start position:0% +transport through it and tell you what +the Spectra is you run that for a few + + align:start position:0% +the Spectra is you run that for a few + + + align:start position:0% +the Spectra is you run that for a few +different rows and T's then and you + + align:start position:0% +different rows and T's then and you + + + align:start position:0% +different rows and T's then and you +create a table of Spectra of a different + + align:start position:0% +create a table of Spectra of a different + + + align:start position:0% +create a table of Spectra of a different +row and T you can very quickly fit that + + align:start position:0% +row and T you can very quickly fit that + + + align:start position:0% +row and T you can very quickly fit that +to your experimental Spectrum so um none + + align:start position:0% +to your experimental Spectrum so um none + + + align:start position:0% +to your experimental Spectrum so um none +of this stuff is impossible just if + + align:start position:0% +of this stuff is impossible just if + + + align:start position:0% +of this stuff is impossible just if +you're doing it from scrp be very hard + + align:start position:0% +you're doing it from scrp be very hard + + + align:start position:0% +you're doing it from scrp be very hard +yeah I'll just + + align:start position:0% + + + + align:start position:0% + +technical yeah that's a great question + + align:start position:0% +technical yeah that's a great question + + + align:start position:0% +technical yeah that's a great question +so you know what we talked about here is + + align:start position:0% +so you know what we talked about here is + + + align:start position:0% +so you know what we talked about here is +that there is some photon with some + + align:start position:0% +that there is some photon with some + + + align:start position:0% +that there is some photon with some +energy right so if we think that that is + + align:start position:0% +energy right so if we think that that is + + + align:start position:0% +energy right so if we think that that is +true Spectrum should look like a set of + + align:start position:0% +true Spectrum should look like a set of + + + align:start position:0% +true Spectrum should look like a set of +Delta functions right and those Delta + + align:start position:0% +Delta functions right and those Delta + + + align:start position:0% +Delta functions right and those Delta +functions should sit at Omega i j and I + + align:start position:0% +functions should sit at Omega i j and I + + + align:start position:0% +functions should sit at Omega i j and I +know the Delta functions that are + + align:start position:0% +know the Delta functions that are + + + align:start position:0% +know the Delta functions that are +infinite but they should have a height + + align:start position:0% +infinite but they should have a height + + + align:start position:0% +infinite but they should have a height +that is related to the strength of the + + align:start position:0% +that is related to the strength of the + + + align:start position:0% +that is related to the strength of the +transition + + align:start position:0% +transition + + + align:start position:0% +transition +here what we'll talk about next lecture + + align:start position:0% +here what we'll talk about next lecture + + + align:start position:0% +here what we'll talk about next lecture +is line broad so that is when these + + align:start position:0% +is line broad so that is when these + + + align:start position:0% +is line broad so that is when these +lines are broadened by other processes + + align:start position:0% +lines are broadened by other processes + + + align:start position:0% +lines are broadened by other processes +and we may be able to in some + + align:start position:0% +and we may be able to in some + + + align:start position:0% +and we may be able to in some +circumstances learn more about the + + align:start position:0% +circumstances learn more about the + + + align:start position:0% +circumstances learn more about the +plasma from the broadening for example + + align:start position:0% +plasma from the broadening for example + + + align:start position:0% +plasma from the broadening for example +if there's Doppler Broad will learn + + align:start position:0% +if there's Doppler Broad will learn + + + align:start position:0% +if there's Doppler Broad will learn +about the temperature there's Stark + + align:start position:0% +about the temperature there's Stark + + + align:start position:0% +about the temperature there's Stark +broadening we'll learn about the density + + align:start position:0% +broadening we'll learn about the density + + + align:start position:0% +broadening we'll learn about the density +uh and then there are other Zan + + align:start position:0% +uh and then there are other Zan + + + align:start position:0% +uh and then there are other Zan +splitting and things like that that may + + align:start position:0% +splitting and things like that that may + + + align:start position:0% +splitting and things like that that may +even be related to Magnetic but we'll + + align:start position:0% +even be related to Magnetic but we'll + + + align:start position:0% +even be related to Magnetic but we'll +get on to that + + align:start position:0% + + + + align:start position:0% + +later I would I would say yes in general + + align:start position:0% +later I would I would say yes in general + + + align:start position:0% +later I would I would say yes in general +and the worst uh case of this is the + + align:start position:0% +and the worst uh case of this is the + + + align:start position:0% +and the worst uh case of this is the +fact that this is line integrated so + + align:start position:0% +fact that this is line integrated so + + + align:start position:0% +fact that this is line integrated so +we're going through the plasma here and + + align:start position:0% +we're going through the plasma here and + + + align:start position:0% +we're going through the plasma here and +we're collecting all of that light and + + align:start position:0% +we're collecting all of that light and + + + align:start position:0% +we're collecting all of that light and +so if the plasma for + + align:start position:0% +so if the plasma for + + + align:start position:0% +so if the plasma for +example row or t changes along that + + align:start position:0% +example row or t changes along that + + + align:start position:0% +example row or t changes along that +curve then you you you can't say exactly + + align:start position:0% +curve then you you you can't say exactly + + + align:start position:0% +curve then you you you can't say exactly +how that density changes because there + + align:start position:0% +how that density changes because there + + + align:start position:0% +how that density changes because there +are a lots of different solutions you + + align:start position:0% +are a lots of different solutions you + + + align:start position:0% +are a lots of different solutions you +know that give you the same results so + + align:start position:0% +know that give you the same results so + + + align:start position:0% +know that give you the same results so +definitely not people do like arble + + align:start position:0% +definitely not people do like arble + + + align:start position:0% +definitely not people do like arble +inverted spectroscopy and very cool + + align:start position:0% +inverted spectroscopy and very cool + + + align:start position:0% +inverted spectroscopy and very cool +techniques like that when they measure + + align:start position:0% +techniques like that when they measure + + + align:start position:0% +techniques like that when they measure +lots of lines of sight and have symmetry + + align:start position:0% +lots of lines of sight and have symmetry + + + align:start position:0% +lots of lines of sight and have symmetry +assumption but that's quite tricky + + align:start position:0% +assumption but that's quite tricky + + + align:start position:0% +assumption but that's quite tricky +any questions + + align:start position:0% + + + + align:start position:0% + +online okay I'm gonna try and do the + + align:start position:0% +online okay I'm gonna try and do the + + + align:start position:0% +online okay I'm gonna try and do the +line ratio thing let's see how this + + align:start position:0% + + + + align:start position:0% + +goes you may have a + + align:start position:0% + + + + align:start position:0% + +spectrum with some very well isolated + + align:start position:0% +spectrum with some very well isolated + + + align:start position:0% +spectrum with some very well isolated +lines so these lines could be + + align:start position:0% +lines so these lines could be + + + align:start position:0% +lines so these lines could be +ones that are some distance apart from + + align:start position:0% +ones that are some distance apart from + + + align:start position:0% +ones that are some distance apart from +any other lines they stand by themselves + + align:start position:0% +any other lines they stand by themselves + + + align:start position:0% +any other lines they stand by themselves +it's very clear what their wavelength is + + align:start position:0% +it's very clear what their wavelength is + + + align:start position:0% +it's very clear what their wavelength is +or their frequency is there's no + + align:start position:0% +or their frequency is there's no + + + align:start position:0% +or their frequency is there's no +confusing with anything else an example + + align:start position:0% +confusing with anything else an example + + + align:start position:0% +confusing with anything else an example +of a poorly separated line would be if + + align:start position:0% +of a poorly separated line would be if + + + align:start position:0% +of a poorly separated line would be if +you have + + align:start position:0% +you have + + + align:start position:0% +you have +three lines all on top of each other + + align:start position:0% +three lines all on top of each other + + + align:start position:0% +three lines all on top of each other +like this because these lines are + + align:start position:0% +like this because these lines are + + + align:start position:0% +like this because these lines are +probably adding together in some + + align:start position:0% +probably adding together in some + + + align:start position:0% +probably adding together in some +way you can't exactly tell what the + + align:start position:0% +way you can't exactly tell what the + + + align:start position:0% +way you can't exactly tell what the +intensity of each of these is but if you + + align:start position:0% +intensity of each of these is but if you + + + align:start position:0% +intensity of each of these is but if you +have nice well separated lines then you + + align:start position:0% +have nice well separated lines then you + + + align:start position:0% +have nice well separated lines then you +have some intensity coefficient for this + + align:start position:0% +have some intensity coefficient for this + + + align:start position:0% +have some intensity coefficient for this +one some intensity coefficient for this + + align:start position:0% +one some intensity coefficient for this + + + align:start position:0% +one some intensity coefficient for this +one here so this line ratio + + align:start position:0% + + + + align:start position:0% + +technique you need to have strong + + align:start position:0% + + + + align:start position:0% + +isolated and identified you need to + + align:start position:0% +isolated and identified you need to + + + align:start position:0% +isolated and identified you need to +know what these lines correspond to so + + align:start position:0% +know what these lines correspond to so + + + align:start position:0% +know what these lines correspond to so +identified in this case means we need to + + align:start position:0% +identified in this case means we need to + + + align:start position:0% +identified in this case means we need to +know what the ionization state is for it + + align:start position:0% +know what the ionization state is for it + + + align:start position:0% +know what the ionization state is for it +and we also need to know what upper + + align:start position:0% +and we also need to know what upper + + + align:start position:0% +and we also need to know what upper +level and lower level uh it corresponds + + align:start position:0% +level and lower level uh it corresponds + + + align:start position:0% +level and lower level uh it corresponds +to within that ionization state so we + + align:start position:0% +to within that ionization state so we + + + align:start position:0% +to within that ionization state so we +need to know the uh + + align:start position:0% +need to know the uh + + + align:start position:0% +need to know the uh +I guess we technically need to know the + + align:start position:0% +I guess we technically need to know the + + + align:start position:0% +I guess we technically need to know the +density of the Upper State + + align:start position:0% +density of the Upper State + + + align:start position:0% +density of the Upper State +here and so an example of this would be + + align:start position:0% +here and so an example of this would be + + + align:start position:0% +here and so an example of this would be +you know if I have a line that comes + + align:start position:0% +you know if I have a line that comes + + + align:start position:0% +you know if I have a line that comes +from aluminum that is twice ionized and + + align:start position:0% +from aluminum that is twice ionized and + + + align:start position:0% +from aluminum that is twice ionized and +aluminum which is three times ionized or + + align:start position:0% +aluminum which is three times ionized or + + + align:start position:0% +aluminum which is three times ionized or +something like that these two ions will + + align:start position:0% +something like that these two ions will + + + align:start position:0% +something like that these two ions will +have very strong lines for certain + + align:start position:0% +have very strong lines for certain + + + align:start position:0% +have very strong lines for certain +transitions you know you'll often have a + + align:start position:0% +transitions you know you'll often have a + + + align:start position:0% +transitions you know you'll often have a +very strong transition from some Upper + + align:start position:0% +very strong transition from some Upper + + + align:start position:0% +very strong transition from some Upper +State the lowest line up a state back + + align:start position:0% +State the lowest line up a state back + + + align:start position:0% +State the lowest line up a state back +down to the ground state because in + + align:start position:0% +down to the ground state because in + + + align:start position:0% +down to the ground state because in +general that's where you're going to end + + align:start position:0% +general that's where you're going to end + + + align:start position:0% +general that's where you're going to end +up and also in general you have like a + + align:start position:0% +up and also in general you have like a + + + align:start position:0% +up and also in general you have like a +large energy gap here so this is pretty + + align:start position:0% +large energy gap here so this is pretty + + + align:start position:0% +large energy gap here so this is pretty +favorable so maybe you've got some well + + align:start position:0% +favorable so maybe you've got some well + + + align:start position:0% +favorable so maybe you've got some well +isolated lines that you know correspond + + align:start position:0% +isolated lines that you know correspond + + + align:start position:0% +isolated lines that you know correspond +from a mission from an upper level to + + align:start position:0% +from a mission from an upper level to + + + align:start position:0% +from a mission from an upper level to +down to the ground level here and you + + align:start position:0% +down to the ground level here and you + + + align:start position:0% +down to the ground level here and you +can measure their intensity very well + + align:start position:0% +can measure their intensity very well + + + align:start position:0% +can measure their intensity very well +right so we now know the intensity of + + align:start position:0% +right so we now know the intensity of + + + align:start position:0% +right so we now know the intensity of +Omega one we know the intensity of Omega + + align:start position:0% +Omega one we know the intensity of Omega + + + align:start position:0% +Omega one we know the intensity of Omega +2 and this is what I mean by strong you + + align:start position:0% +2 and this is what I mean by strong you + + + align:start position:0% +2 and this is what I mean by strong you +don't want to be doing this on little + + align:start position:0% +don't want to be doing this on little + + + align:start position:0% +don't want to be doing this on little +lines that are down here in the noise + + align:start position:0% +lines that are down here in the noise + + + align:start position:0% +lines that are down here in the noise +because we can't measure their intensity + + align:start position:0% +because we can't measure their intensity + + + align:start position:0% +because we can't measure their intensity +very + + align:start position:0% +very + + + align:start position:0% +very +well so what you do with these lines is + + align:start position:0% +well so what you do with these lines is + + + align:start position:0% +well so what you do with these lines is +you say + + align:start position:0% + + + + align:start position:0% + +okay I know + + align:start position:0% + + + + align:start position:0% + +that the + + align:start position:0% +that the + + + align:start position:0% +that the +intensity of this + + align:start position:0% + + + + align:start position:0% + +line the intensity at some frequency + + align:start position:0% +line the intensity at some frequency + + + align:start position:0% +line the intensity at some frequency +corresponding to the transition from the + + align:start position:0% +corresponding to the transition from the + + + align:start position:0% +corresponding to the transition from the +upper state to the Lower State here + + align:start position:0% +upper state to the Lower State here + + + align:start position:0% +upper state to the Lower State here +is equal to the number of ions in the + + align:start position:0% +is equal to the number of ions in the + + + align:start position:0% +is equal to the number of ions in the +Upper + + align:start position:0% +Upper + + + align:start position:0% +Upper +State Times by the probability of + + align:start position:0% +State Times by the probability of + + + align:start position:0% +State Times by the probability of +transition from the upper state to the + + align:start position:0% +transition from the upper state to the + + + align:start position:0% +transition from the upper state to the +Lower State and then because this + + align:start position:0% +Lower State and then because this + + + align:start position:0% +Lower State and then because this +intensity often has units of energy here + + align:start position:0% +intensity often has units of energy here + + + align:start position:0% +intensity often has units of energy here +right this is like a power we obviously + + align:start position:0% +right this is like a power we obviously + + + align:start position:0% +right this is like a power we obviously +need to have an energy unit here so this + + align:start position:0% +need to have an energy unit here so this + + + align:start position:0% +need to have an energy unit here so this +is H bar Omega upper lower so if we have + + align:start position:0% +is H bar Omega upper lower so if we have + + + align:start position:0% +is H bar Omega upper lower so if we have +two lines here we can take the ratio of + + align:start position:0% +two lines here we can take the ratio of + + + align:start position:0% +two lines here we can take the ratio of +these so we could have intensity of + + align:start position:0% +these so we could have intensity of + + + align:start position:0% +these so we could have intensity of +Omega Zed Upp or + + align:start position:0% +Omega Zed Upp or + + + align:start position:0% +Omega Zed Upp or +lower over intensity of Omega Z minus + + align:start position:0% +lower over intensity of Omega Z minus + + + align:start position:0% +lower over intensity of Omega Z minus +one up or lower like that and we can see + + align:start position:0% +one up or lower like that and we can see + + + align:start position:0% +one up or lower like that and we can see +then that we're going to get out a zed + + align:start position:0% +then that we're going to get out a zed + + + align:start position:0% +then that we're going to get out a zed +upper Over N The Zed minus one + + align:start position:0% +upper Over N The Zed minus one + + + align:start position:0% +upper Over N The Zed minus one +upper a upper + + align:start position:0% +upper a upper + + + align:start position:0% +upper a upper +lower a upper lower I'll put little + + align:start position:0% +lower a upper lower I'll put little + + + align:start position:0% +lower a upper lower I'll put little +superscripts on these so we remember + + align:start position:0% +superscripts on these so we remember + + + align:start position:0% +superscripts on these so we remember +these are different coefficients for our + + align:start position:0% +these are different coefficients for our + + + align:start position:0% +these are different coefficients for our +different ionization States and then the + + align:start position:0% +different ionization States and then the + + + align:start position:0% +different ionization States and then the +H bars will can + + align:start position:0% +H bars will can + + + align:start position:0% +H bars will can +we'll have an Omega Z up + + align:start position:0% + + + + align:start position:0% + +lower so these are things that we can + + align:start position:0% + + + + align:start position:0% + +calculate look up in our Atomic + + align:start position:0% +calculate look up in our Atomic + + + align:start position:0% +calculate look up in our Atomic +database these are things that we have + + align:start position:0% +database these are things that we have + + + align:start position:0% +database these are things that we have +literally measured because our + + align:start position:0% +literally measured because our + + + align:start position:0% +literally measured because our +spectrometer is well + + align:start position:0% + + + + align:start position:0% + +calibrated this line ratio we've also + + align:start position:0% +calibrated this line ratio we've also + + + align:start position:0% +calibrated this line ratio we've also +just measured + + align:start position:0% + + + + align:start position:0% + +so that means we can + + align:start position:0% + + + + align:start position:0% + +infer the ratio between the number of + + align:start position:0% +infer the ratio between the number of + + + align:start position:0% +infer the ratio between the number of +atoms in one ionization State and + + align:start position:0% +atoms in one ionization State and + + + align:start position:0% +atoms in one ionization State and +another ionization State here I've done + + align:start position:0% +another ionization State here I've done + + + align:start position:0% +another ionization State here I've done +them as neighboring ionization States + + align:start position:0% +them as neighboring ionization States + + + align:start position:0% +them as neighboring ionization States +this could be like Zed minus two Zed + + align:start position:0% +this could be like Zed minus two Zed + + + align:start position:0% +this could be like Zed minus two Zed +minus 3 it doesn't really matter you + + align:start position:0% +minus 3 it doesn't really matter you + + + align:start position:0% +minus 3 it doesn't really matter you +don't generally get that because for a + + align:start position:0% +don't generally get that because for a + + + align:start position:0% +don't generally get that because for a +certain temperature you only have a few + + align:start position:0% +certain temperature you only have a few + + + align:start position:0% +certain temperature you only have a few +ionization States active at a time and + + align:start position:0% +ionization States active at a time and + + + align:start position:0% +ionization States active at a time and +because you've now inferred this + + align:start position:0% +because you've now inferred this + + + align:start position:0% +because you've now inferred this +quantity you can then use an + + align:start position:0% + + + + align:start position:0% + +equilibrium such as + + align:start position:0% +equilibrium such as + + + align:start position:0% +equilibrium such as +Saha and you can get out the temperature + + align:start position:0% +Saha and you can get out the temperature + + + align:start position:0% +Saha and you can get out the temperature +so you can say your sah equilibrium says + + align:start position:0% +so you can say your sah equilibrium says + + + align:start position:0% +so you can say your sah equilibrium says +at a certain temperature I should have + + align:start position:0% +at a certain temperature I should have + + + align:start position:0% +at a certain temperature I should have +twice as many ions uh in the lower + + align:start position:0% +twice as many ions uh in the lower + + + align:start position:0% +twice as many ions uh in the lower +ionization State at the upper ionization + + align:start position:0% +ionization State at the upper ionization + + + align:start position:0% +ionization State at the upper ionization +State that's what I see therefore that + + align:start position:0% +State that's what I see therefore that + + + align:start position:0% +State that's what I see therefore that +is my temperature so just simply from + + align:start position:0% +is my temperature so just simply from + + + align:start position:0% +is my temperature so just simply from +looking at line ratios without doing all + + align:start position:0% +looking at line ratios without doing all + + + align:start position:0% +looking at line ratios without doing all +of this complicated modeling you may be + + align:start position:0% +of this complicated modeling you may be + + + align:start position:0% +of this complicated modeling you may be +able to get a handle on the temperature + + align:start position:0% +able to get a handle on the temperature + + + align:start position:0% +able to get a handle on the temperature +and that could be a first step that you + + align:start position:0% +and that could be a first step that you + + + align:start position:0% +and that could be a first step that you +then feed back into your algorithm where + + align:start position:0% +then feed back into your algorithm where + + + align:start position:0% +then feed back into your algorithm where +you say I know what the starting + + align:start position:0% +you say I know what the starting + + + align:start position:0% +you say I know what the starting +temperature roughly is so let's only + + align:start position:0% +temperature roughly is so let's only + + + align:start position:0% +temperature roughly is so let's only +look in the solution space surround it + + align:start position:0% +look in the solution space surround it + + + align:start position:0% +look in the solution space surround it +so this is quite a powerful technique + + align:start position:0% +so this is quite a powerful technique + + + align:start position:0% +so this is quite a powerful technique +and often this is as far as people go + + align:start position:0% +and often this is as far as people go + + + align:start position:0% +and often this is as far as people go +they'll do a line ratio they'll get a + + align:start position:0% +they'll do a line ratio they'll get a + + + align:start position:0% +they'll do a line ratio they'll get a +temperature out and I mentioned earlier + + align:start position:0% +temperature out and I mentioned earlier + + + align:start position:0% +temperature out and I mentioned earlier +the even simpler thing to do is just be + + align:start position:0% +the even simpler thing to do is just be + + + align:start position:0% +the even simpler thing to do is just be +like hey I've got a line that + + align:start position:0% +like hey I've got a line that + + + align:start position:0% +like hey I've got a line that +corresponds to uh aluminium 3 plus ions + + align:start position:0% +corresponds to uh aluminium 3 plus ions + + + align:start position:0% +corresponds to uh aluminium 3 plus ions +that only happens when the temperature + + align:start position:0% +that only happens when the temperature + + + align:start position:0% +that only happens when the temperature +in the plasma is like 10 electron volts + + align:start position:0% +in the plasma is like 10 electron volts + + + align:start position:0% +in the plasma is like 10 electron volts +maybe 12 maybe eight but that means like + + align:start position:0% +maybe 12 maybe eight but that means like + + + align:start position:0% +maybe 12 maybe eight but that means like +my plasma is probably 10 Els perfect and + + align:start position:0% +my plasma is probably 10 Els perfect and + + + align:start position:0% +my plasma is probably 10 Els perfect and +that's that's good enough for a lot of + + align:start position:0% +that's that's good enough for a lot of + + + align:start position:0% +that's that's good enough for a lot of +purposes okay questions on + + align:start position:0% + + + + align:start position:0% + +this + + align:start position:0% + + + + align:start position:0% + +yes + + align:start position:0% +yes + + + align:start position:0% +yes +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +yeah so no so absolutely like you're I + + align:start position:0% +yeah so no so absolutely like you're I + + + align:start position:0% +yeah so no so absolutely like you're I +say you're measuring it but you know it + + align:start position:0% +say you're measuring it but you know it + + + align:start position:0% +say you're measuring it but you know it +right it's close enough yes there may be + + align:start position:0% +right it's close enough yes there may be + + + align:start position:0% +right it's close enough yes there may be +some do the shift involved to it or some + + align:start position:0% +some do the shift involved to it or some + + + align:start position:0% +some do the shift involved to it or some +of these other line broadening + + align:start position:0% +of these other line broadening + + + align:start position:0% +of these other line broadening +mechanisms which means you don't know + + align:start position:0% +mechanisms which means you don't know + + + align:start position:0% +mechanisms which means you don't know +exactly where this is you may also have + + align:start position:0% +exactly where this is you may also have + + + align:start position:0% +exactly where this is you may also have +uncertainties in your Atomic code + + align:start position:0% +uncertainties in your Atomic code + + + align:start position:0% +uncertainties in your Atomic code +especially when you're working with + + align:start position:0% +especially when you're working with + + + align:start position:0% +especially when you're working with +x-rays uh the X-ray uh spectroscopy + + align:start position:0% +x-rays uh the X-ray uh spectroscopy + + + align:start position:0% +x-rays uh the X-ray uh spectroscopy +models can be quite unaccurate to within + + align:start position:0% +models can be quite unaccurate to within + + + align:start position:0% +models can be quite unaccurate to within +like 20% and that's still pretty good + + align:start position:0% +like 20% and that's still pretty good + + + align:start position:0% +like 20% and that's still pretty good +and so you say okay I thought it was + + align:start position:0% +and so you say okay I thought it was + + + align:start position:0% +and so you say okay I thought it was +going to be here there's nothing + + align:start position:0% +going to be here there's nothing + + + align:start position:0% +going to be here there's nothing +anywhere near here apart from this line + + align:start position:0% +anywhere near here apart from this line + + + align:start position:0% +anywhere near here apart from this line +so that is probably this line so making + + align:start position:0% +so that is probably this line so making + + + align:start position:0% +so that is probably this line so making +a line identification is like very tough + + align:start position:0% +a line identification is like very tough + + + align:start position:0% +a line identification is like very tough +and especially in a plasma in the + + align:start position:0% +and especially in a plasma in the + + + align:start position:0% +and especially in a plasma in the +laboratory you think my plasma is made + + align:start position:0% +laboratory you think my plasma is made + + + align:start position:0% +laboratory you think my plasma is made +out of aluminium because that's what + + align:start position:0% +out of aluminium because that's what + + + align:start position:0% +out of aluminium because that's what +you've made it out of but then you + + align:start position:0% +you've made it out of but then you + + + align:start position:0% +you've made it out of but then you +forget that the lenses are coated with + + align:start position:0% +forget that the lenses are coated with + + + align:start position:0% +forget that the lenses are coated with +magnesium chloride and so there may be + + align:start position:0% +magnesium chloride and so there may be + + + align:start position:0% +magnesium chloride and so there may be +magnesium chloride absorption lines when + + align:start position:0% +magnesium chloride absorption lines when + + + align:start position:0% +magnesium chloride absorption lines when +the x-rays from your experiment photoon + + align:start position:0% +the x-rays from your experiment photoon + + + align:start position:0% +the x-rays from your experiment photoon +or your electrode is made out of copper + + align:start position:0% +or your electrode is made out of copper + + + align:start position:0% +or your electrode is made out of copper +and now you've got copper lines as well + + align:start position:0% +and now you've got copper lines as well + + + align:start position:0% +and now you've got copper lines as well +or someone left their thumb print on one + + align:start position:0% +or someone left their thumb print on one + + + align:start position:0% +or someone left their thumb print on one +of the electrodes and now you have + + align:start position:0% +of the electrodes and now you have + + + align:start position:0% +of the electrodes and now you have +hydrocarbons and salt so you have sodium + + align:start position:0% +hydrocarbons and salt so you have sodium + + + align:start position:0% +hydrocarbons and salt so you have sodium +lines on there as well like all of this + + align:start position:0% +lines on there as well like all of this + + + align:start position:0% +lines on there as well like all of this +has happened to me very recently so so + + align:start position:0% +has happened to me very recently so so + + + align:start position:0% +has happened to me very recently so so +it's actually it's a nightmare you think + + align:start position:0% +it's actually it's a nightmare you think + + + align:start position:0% +it's actually it's a nightmare you think +like ah my plasma is made out of this + + align:start position:0% +like ah my plasma is made out of this + + + align:start position:0% +like ah my plasma is made out of this +and the answer is no your plasma is made + + align:start position:0% +and the answer is no your plasma is made + + + align:start position:0% +and the answer is no your plasma is made +out of whatever crap there is in the + + align:start position:0% +out of whatever crap there is in the + + + align:start position:0% +out of whatever crap there is in the +machine so yeah okay other + + align:start position:0% + + + + align:start position:0% + +yeah yes I'm preferably negligible right + + align:start position:0% +yeah yes I'm preferably negligible right + + + align:start position:0% +yeah yes I'm preferably negligible right +so yeah this is this is definitely a + + align:start position:0% +so yeah this is this is definitely a + + + align:start position:0% +so yeah this is this is definitely a +technique that works best if it's + + align:start position:0% +technique that works best if it's + + + align:start position:0% +technique that works best if it's +optically thin you you could use it if + + align:start position:0% +optically thin you you could use it if + + + align:start position:0% +optically thin you you could use it if +you have very strong priers about what + + align:start position:0% +you have very strong priers about what + + + align:start position:0% +you have very strong priers about what +the density and temperature are so that + + align:start position:0% +the density and temperature are so that + + + align:start position:0% +the density and temperature are so that +you can calculate the opacity but if you + + align:start position:0% +you can calculate the opacity but if you + + + align:start position:0% +you can calculate the opacity but if you +have those strong priers then you don't + + align:start position:0% +have those strong priers then you don't + + + align:start position:0% +have those strong priers then you don't +need to do this technique you can sort + + align:start position:0% +need to do this technique you can sort + + + align:start position:0% +need to do this technique you can sort +of use it to confirm post talk + + align:start position:0% +of use it to confirm post talk + + + align:start position:0% +of use it to confirm post talk +afterwards that your technically + + align:start position:0% + + + + align:start position:0% + +yeah well I mean that's that's really + + align:start position:0% +yeah well I mean that's that's really + + + align:start position:0% +yeah well I mean that's that's really +tricky if you're able to do an + + align:start position:0% +tricky if you're able to do an + + + align:start position:0% +tricky if you're able to do an +experiment where you can increase the + + align:start position:0% +experiment where you can increase the + + + align:start position:0% +experiment where you can increase the +depth of your plasma that would be one + + align:start position:0% +depth of your plasma that would be one + + + align:start position:0% +depth of your plasma that would be one +easy way to do it but of course if + + align:start position:0% +easy way to do it but of course if + + + align:start position:0% +easy way to do it but of course if +you're in a toac you can't just make the + + align:start position:0% +you're in a toac you can't just make the + + + align:start position:0% +you're in a toac you can't just make the +plasma twice as big just to see what + + align:start position:0% +plasma twice as big just to see what + + + align:start position:0% +plasma twice as big just to see what +would happen to the lines and so so um + + align:start position:0% +would happen to the lines and so so um + + + align:start position:0% +would happen to the lines and so so um +in some experiments you can you could + + align:start position:0% +in some experiments you can you could + + + align:start position:0% +in some experiments you can you could +use that technique otherwise yeah you'll + + align:start position:0% +use that technique otherwise yeah you'll + + + align:start position:0% +use that technique otherwise yeah you'll +have to use maybe other Diagnostics to + + align:start position:0% +have to use maybe other Diagnostics to + + + align:start position:0% +have to use maybe other Diagnostics to +give you ideas of density and + + align:start position:0% +give you ideas of density and + + + align:start position:0% +give you ideas of density and +temperature that you can then check how + + align:start position:0% +temperature that you can then check how + + + align:start position:0% +temperature that you can then check how +optically thick the various lines are + + align:start position:0% +optically thick the various lines are + + + align:start position:0% +optically thick the various lines are +and then um iterate from + + align:start position:0% + + + + align:start position:0% + +there or simulation right as well give + + align:start position:0% +there or simulation right as well give + + + align:start position:0% +there or simulation right as well give +us some hints as what the answer + + align:start position:0% + + + + align:start position:0% + +is any other + + align:start position:0% + + + + align:start position:0% + +questions what are we doing + + align:start position:0% +questions what are we doing + + + align:start position:0% +questions what are we doing +oh x-ray spectroscopy very + + align:start position:0% + + + + align:start position:0% + +good so the reason I'm talking about + + align:start position:0% +good so the reason I'm talking about + + + align:start position:0% +good so the reason I'm talking about +x-ray spectroscopy in particular is that + + align:start position:0% +x-ray spectroscopy in particular is that + + + align:start position:0% +x-ray spectroscopy in particular is that +quite a few people doing plasma physics + + align:start position:0% +quite a few people doing plasma physics + + + align:start position:0% +quite a few people doing plasma physics +end up using x-ray spectroscopy and also + + align:start position:0% +end up using x-ray spectroscopy and also + + + align:start position:0% +end up using x-ray spectroscopy and also +it's got it sort of Niche nomenclature + + align:start position:0% +it's got it sort of Niche nomenclature + + + align:start position:0% +it's got it sort of Niche nomenclature +uh that I wanted to introduce you to so + + align:start position:0% +uh that I wanted to introduce you to so + + + align:start position:0% +uh that I wanted to introduce you to so +that when people start talking about it + + align:start position:0% +that when people start talking about it + + + align:start position:0% +that when people start talking about it +you have some vague idea of what's going + + align:start position:0% + + + + align:start position:0% + +on of course all forms of spectroscopy + + align:start position:0% +on of course all forms of spectroscopy + + + align:start position:0% +on of course all forms of spectroscopy +are valid lot of people do visible + + align:start position:0% +are valid lot of people do visible + + + align:start position:0% +are valid lot of people do visible +spectroscopy infrared ultraviolet but if + + align:start position:0% +spectroscopy infrared ultraviolet but if + + + align:start position:0% +spectroscopy infrared ultraviolet but if +you're working with plasmas at Fusion + + align:start position:0% +you're working with plasmas at Fusion + + + align:start position:0% +you're working with plasmas at Fusion +conditions which are like killer + + align:start position:0% +conditions which are like killer + + + align:start position:0% +conditions which are like killer +electron volt plasmas then you're going + + align:start position:0% +electron volt plasmas then you're going + + + align:start position:0% +electron volt plasmas then you're going +to be getting killer electron volt + + align:start position:0% +to be getting killer electron volt + + + align:start position:0% +to be getting killer electron volt +photons right and so that means they're + + align:start position:0% +photons right and so that means they're + + + align:start position:0% +photons right and so that means they're +in the X-ray regime and x-ray + + align:start position:0% +in the X-ray regime and x-ray + + + align:start position:0% +in the X-ray regime and x-ray +spectroscopy can be a little bit + + align:start position:0% + + + + align:start position:0% + +different so x-ray spectroscopy has very + + align:start position:0% +different so x-ray spectroscopy has very + + + align:start position:0% +different so x-ray spectroscopy has very +strong characteristic lines + + align:start position:0% + + + + align:start position:0% + +so these lines tend to have a high + + align:start position:0% +so these lines tend to have a high + + + align:start position:0% +so these lines tend to have a high +transition probability a i j and they + + align:start position:0% +transition probability a i j and they + + + align:start position:0% +transition probability a i j and they +tend to be + + align:start position:0% +tend to be + + + align:start position:0% +tend to be +narrow so they show up very very + + align:start position:0% +narrow so they show up very very + + + align:start position:0% +narrow so they show up very very +strongly they're easy to identify + + align:start position:0% +strongly they're easy to identify + + + align:start position:0% +strongly they're easy to identify +they're easy to work with and these + + align:start position:0% +they're easy to work with and these + + + align:start position:0% +they're easy to work with and these +lines corresponds to + + align:start position:0% +lines corresponds to + + + align:start position:0% +lines corresponds to +Transitions often between some of the + + align:start position:0% +Transitions often between some of the + + + align:start position:0% +Transitions often between some of the +lowest energy levels inside our atom + + align:start position:0% +lowest energy levels inside our atom + + + align:start position:0% +lowest energy levels inside our atom +so here this one is not referring to + + align:start position:0% +so here this one is not referring to + + + align:start position:0% +so here this one is not referring to +some abstract concept here this is + + align:start position:0% +some abstract concept here this is + + + align:start position:0% +some abstract concept here this is +literally n equals one right so this is + + align:start position:0% +literally n equals one right so this is + + + align:start position:0% +literally n equals one right so this is +the lowest energy level down there the + + align:start position:0% +the lowest energy level down there the + + + align:start position:0% +the lowest energy level down there the +energy level that your ground state + + align:start position:0% +energy level that your ground state + + + align:start position:0% +energy level that your ground state +hydrogen atom uh occupies here and these + + align:start position:0% +hydrogen atom uh occupies here and these + + + align:start position:0% +hydrogen atom uh occupies here and these +are the other excited stats because + + align:start position:0% +are the other excited stats because + + + align:start position:0% +are the other excited stats because +we're dealing with relatively High + + align:start position:0% +we're dealing with relatively High + + + align:start position:0% +we're dealing with relatively High +Energy Systems when we're doing EP + + align:start position:0% +Energy Systems when we're doing EP + + + align:start position:0% +Energy Systems when we're doing EP +spectroscopy our ion may be almost + + align:start position:0% +spectroscopy our ion may be almost + + + align:start position:0% +spectroscopy our ion may be almost +completely stripped there may be only + + align:start position:0% +completely stripped there may be only + + + align:start position:0% +completely stripped there may be only +two or three or one electrons here so + + align:start position:0% +two or three or one electrons here so + + + align:start position:0% +two or three or one electrons here so +and people start referring to these ions + + align:start position:0% +and people start referring to these ions + + + align:start position:0% +and people start referring to these ions +as helium like or lithium like so a + + align:start position:0% +as helium like or lithium like so a + + + align:start position:0% +as helium like or lithium like so a +helium + + align:start position:0% + + + + align:start position:0% + +like unsurprisingly has two electrons + + align:start position:0% +like unsurprisingly has two electrons + + + align:start position:0% +like unsurprisingly has two electrons +and a lithium + + align:start position:0% +and a lithium + + + align:start position:0% +and a lithium +like has three + + align:start position:0% +like has three + + + align:start position:0% +like has three +electrons what they mean is this could + + align:start position:0% +electrons what they mean is this could + + + align:start position:0% +electrons what they mean is this could +be something like tungsten or aluminium + + align:start position:0% +be something like tungsten or aluminium + + + align:start position:0% +be something like tungsten or aluminium +or anything else like that but it's so + + align:start position:0% +or anything else like that but it's so + + + align:start position:0% +or anything else like that but it's so +ionized that there's only two or three + + align:start position:0% +ionized that there's only two or three + + + align:start position:0% +ionized that there's only two or three +electrons left and that means that you + + align:start position:0% +electrons left and that means that you + + + align:start position:0% +electrons left and that means that you +can use all of the + + align:start position:0% +can use all of the + + + align:start position:0% +can use all of the +spectroscopy all of the quantum physics + + align:start position:0% +spectroscopy all of the quantum physics + + + align:start position:0% +spectroscopy all of the quantum physics +that you do on helium which is a a + + align:start position:0% +that you do on helium which is a a + + + align:start position:0% +that you do on helium which is a a +relatively simple system to solve + + align:start position:0% +relatively simple system to solve + + + align:start position:0% +relatively simple system to solve +compared to something more complicated + + align:start position:0% +compared to something more complicated + + + align:start position:0% +compared to something more complicated +and all you have to do is replace the + + align:start position:0% +and all you have to do is replace the + + + align:start position:0% +and all you have to do is replace the +atomic charge the nucleus charge from + + align:start position:0% +atomic charge the nucleus charge from + + + align:start position:0% +atomic charge the nucleus charge from +two to whatever your actual nuclear + + align:start position:0% +two to whatever your actual nuclear + + + align:start position:0% +two to whatever your actual nuclear +charge is so you just take Zed from two + + align:start position:0% +charge is so you just take Zed from two + + + align:start position:0% +charge is so you just take Zed from two +to I don't know 13 for + + align:start position:0% + + + + align:start position:0% + +aluminium but it means that you you have + + align:start position:0% +aluminium but it means that you you have + + + align:start position:0% +aluminium but it means that you you have +a pretty good idea of what these energy + + align:start position:0% +a pretty good idea of what these energy + + + align:start position:0% +a pretty good idea of what these energy +levels are because the quantum physics + + align:start position:0% +levels are because the quantum physics + + + align:start position:0% +levels are because the quantum physics +of low atomic number elements is pretty + + align:start position:0% +of low atomic number elements is pretty + + + align:start position:0% +of low atomic number elements is pretty +well understood so these characteristic + + align:start position:0% +well understood so these characteristic + + + align:start position:0% +well understood so these characteristic +lines will occur when there is some + + align:start position:0% +lines will occur when there is some + + + align:start position:0% +lines will occur when there is some +vacancy in a lower energy level so for + + align:start position:0% +vacancy in a lower energy level so for + + + align:start position:0% +vacancy in a lower energy level so for +example if we have an electron up here + + align:start position:0% +example if we have an electron up here + + + align:start position:0% +example if we have an electron up here +in the N equals 2 level and there's + + align:start position:0% +in the N equals 2 level and there's + + + align:start position:0% +in the N equals 2 level and there's +space in the N equals 1 level to drop + + align:start position:0% +space in the N equals 1 level to drop + + + align:start position:0% +space in the N equals 1 level to drop +down it + + align:start position:0% +down it + + + align:start position:0% +down it +will emit a photon here now why would + + align:start position:0% +will emit a photon here now why would + + + align:start position:0% +will emit a photon here now why would +there be space in this lower energy + + align:start position:0% +there be space in this lower energy + + + align:start position:0% +there be space in this lower energy +level I'd updated by notes and that also + + align:start position:0% +level I'd updated by notes and that also + + + align:start position:0% +level I'd updated by notes and that also +not as updated as well um this may be + + align:start position:0% +not as updated as well um this may be + + + align:start position:0% +not as updated as well um this may be +because of uh collisions or + + align:start position:0% +because of uh collisions or + + + align:start position:0% +because of uh collisions or +photoionization or something else like + + align:start position:0% +photoionization or something else like + + + align:start position:0% +photoionization or something else like +that if we're in a very hot plasma it's + + align:start position:0% +that if we're in a very hot plasma it's + + + align:start position:0% +that if we're in a very hot plasma it's +very reasonable to have hot electrons + + align:start position:0% +very reasonable to have hot electrons + + + align:start position:0% +very reasonable to have hot electrons +flying + + align:start position:0% + + + + align:start position:0% + +around that + + align:start position:0% +around that + + + align:start position:0% +around that +collisionally ionize us or indeed just + + align:start position:0% +collisionally ionize us or indeed just + + + align:start position:0% +collisionally ionize us or indeed just +collisionally excite us up to some very + + align:start position:0% +collisionally excite us up to some very + + + align:start position:0% +collisionally excite us up to some very +high energy level like seven and that + + align:start position:0% +high energy level like seven and that + + + align:start position:0% +high energy level like seven and that +leaves a hole here and because this is + + align:start position:0% +leaves a hole here and because this is + + + align:start position:0% +leaves a hole here and because this is +energetically unfavorable to have a + + align:start position:0% +energetically unfavorable to have a + + + align:start position:0% +energetically unfavorable to have a +lower energy level unfilled one of these + + align:start position:0% +lower energy level unfilled one of these + + + align:start position:0% +lower energy level unfilled one of these +electrons in one of the higher energy + + align:start position:0% +electrons in one of the higher energy + + + align:start position:0% +electrons in one of the higher energy +levels will very rapidly drop down into + + align:start position:0% +levels will very rapidly drop down into + + + align:start position:0% +levels will very rapidly drop down into +here and these different transitions + + align:start position:0% +here and these different transitions + + + align:start position:0% +here and these different transitions +from down to the ground state from two + + align:start position:0% +from down to the ground state from two + + + align:start position:0% +from down to the ground state from two +two and three and so on have different + + align:start position:0% +two and three and so on have different + + + align:start position:0% +two and three and so on have different +names + + align:start position:0% +names + + + align:start position:0% +names +so first of all we have what I called + + align:start position:0% +so first of all we have what I called + + + align:start position:0% +so first of all we have what I called +the kshell + + align:start position:0% + + + + align:start position:0% + +transitions this is transitions from or + + align:start position:0% +transitions this is transitions from or + + + align:start position:0% +transitions this is transitions from or +down to n equals one we have the K + + align:start position:0% +down to n equals one we have the K + + + align:start position:0% +down to n equals one we have the K +Alpha which is from Nal 2 to nals 1 + + align:start position:0% +Alpha which is from Nal 2 to nals 1 + + + align:start position:0% +Alpha which is from Nal 2 to nals 1 +that's the one I've drawn here you have + + align:start position:0% +that's the one I've drawn here you have + + + align:start position:0% +that's the one I've drawn here you have +the K + + align:start position:0% +the K + + + align:start position:0% +the K +beta that's n equals + + align:start position:0% +beta that's n equals + + + align:start position:0% +beta that's n equals +three nals 1 and so on K gamma all that + + align:start position:0% +three nals 1 and so on K gamma all that + + + align:start position:0% +three nals 1 and so on K gamma all that +sort of thing now it turns out that the + + align:start position:0% +sort of thing now it turns out that the + + + align:start position:0% +sort of thing now it turns out that the +K Alpha is always the strongest + + align:start position:0% + + + + align:start position:0% + +transition so you'll typically get an + + align:start position:0% +transition so you'll typically get an + + + align:start position:0% +transition so you'll typically get an +electron dropping down from two to one + + align:start position:0% +electron dropping down from two to one + + + align:start position:0% +electron dropping down from two to one +rather from three to one more quickly + + align:start position:0% +rather from three to one more quickly + + + align:start position:0% +rather from three to one more quickly +and this line will show up more strongly + + align:start position:0% +and this line will show up more strongly + + + align:start position:0% +and this line will show up more strongly +and it's strong again because of this + + align:start position:0% +and it's strong again because of this + + + align:start position:0% +and it's strong again because of this +overlap between the lowest energy state + + align:start position:0% +overlap between the lowest energy state + + + align:start position:0% +overlap between the lowest energy state +and the second highest n equals 2 energy + + align:start position:0% +and the second highest n equals 2 energy + + + align:start position:0% +and the second highest n equals 2 energy +State these wave functions look most + + align:start position:0% +State these wave functions look most + + + align:start position:0% +State these wave functions look most +similar as you start getting out to high + + align:start position:0% +similar as you start getting out to high + + + align:start position:0% +similar as you start getting out to high +ends these wave functions start to look + + align:start position:0% +ends these wave functions start to look + + + align:start position:0% +ends these wave functions start to look +really weird and when you do the overlap + + align:start position:0% +really weird and when you do the overlap + + + align:start position:0% +really weird and when you do the overlap +integral it's not particularly large so + + align:start position:0% +integral it's not particularly large so + + + align:start position:0% +integral it's not particularly large so +Quantum mechanically it's much easier + + align:start position:0% +Quantum mechanically it's much easier + + + align:start position:0% +Quantum mechanically it's much easier +for the electron to transition between + + align:start position:0% +for the electron to transition between + + + align:start position:0% +for the electron to transition between +these two wave functions here so the K + + align:start position:0% +these two wave functions here so the K + + + align:start position:0% +these two wave functions here so the K +Alpha is always + + align:start position:0% +Alpha is always + + + align:start position:0% +Alpha is always +strong we also then have the L + + align:start position:0% + + + + align:start position:0% + +cell this is transitions down to nals + + align:start position:0% +cell this is transitions down to nals + + + align:start position:0% +cell this is transitions down to nals +2 and you know you'll have L Alpha which + + align:start position:0% +2 and you know you'll have L Alpha which + + + align:start position:0% +2 and you know you'll have L Alpha which +is 3 to2 l beta which is four to2 then + + align:start position:0% +is 3 to2 l beta which is four to2 then + + + align:start position:0% +is 3 to2 l beta which is four to2 then +you also have the + + align:start position:0% + + + + align:start position:0% + +mshell and so on but we tend to focus on + + align:start position:0% +mshell and so on but we tend to focus on + + + align:start position:0% +mshell and so on but we tend to focus on +the K shell because these lines are the + + align:start position:0% +the K shell because these lines are the + + + align:start position:0% +the K shell because these lines are the +highest energy Atomic lines you can get + + align:start position:0% +highest energy Atomic lines you can get + + + align:start position:0% +highest energy Atomic lines you can get +from the system because you're dropping + + align:start position:0% +from the system because you're dropping + + + align:start position:0% +from the system because you're dropping +down to the lowest energy level from + + align:start position:0% +down to the lowest energy level from + + + align:start position:0% +down to the lowest energy level from +somewhere else so these lines are very + + align:start position:0% +somewhere else so these lines are very + + + align:start position:0% +somewhere else so these lines are very +bright and they're very good signatures + + align:start position:0% +bright and they're very good signatures + + + align:start position:0% +bright and they're very good signatures +of what the plasma + + align:start position:0% +of what the plasma + + + align:start position:0% +of what the plasma +conditions are so just to give you an + + align:start position:0% + + + + align:start position:0% + +example this is energy here and this is + + align:start position:0% +example this is energy here and this is + + + align:start position:0% +example this is energy here and this is +intensity and we have something like + + align:start position:0% +intensity and we have something like + + + align:start position:0% +intensity and we have something like +copper the copper Spectrum will have + + align:start position:0% +copper the copper Spectrum will have + + + align:start position:0% +copper the copper Spectrum will have +some remon component background here + + align:start position:0% +some remon component background here + + + align:start position:0% +some remon component background here +that you can never get rid of and then + + align:start position:0% +that you can never get rid of and then + + + align:start position:0% +that you can never get rid of and then +at sufficiently high energies we'll + + align:start position:0% +at sufficiently high energies we'll + + + align:start position:0% +at sufficiently high energies we'll +have two peaks like this this one is the + + align:start position:0% +have two peaks like this this one is the + + + align:start position:0% +have two peaks like this this one is the +K Alpha this is the K beta the K Alpha + + align:start position:0% +K Alpha this is the K beta the K Alpha + + + align:start position:0% +K Alpha this is the K beta the K Alpha +in this case is 8.1 + + align:start position:0% + + + + align:start position:0% + +KV and the K beta is + + align:start position:0% + + + + align:start position:0% + +8.9 and these lines are so narrow and so + + align:start position:0% +8.9 and these lines are so narrow and so + + + align:start position:0% +8.9 and these lines are so narrow and so +well defined that they form a very + + align:start position:0% +well defined that they form a very + + + align:start position:0% +well defined that they form a very +strong spectroscopic signature so if I'm + + align:start position:0% +strong spectroscopic signature so if I'm + + + align:start position:0% +strong spectroscopic signature so if I'm +looking inside my toac plasma that I + + align:start position:0% +looking inside my toac plasma that I + + + align:start position:0% +looking inside my toac plasma that I +want to be hydrogen and I look at these + + align:start position:0% +want to be hydrogen and I look at these + + + align:start position:0% +want to be hydrogen and I look at these +high energy killer electron volt ranges + + align:start position:0% +high energy killer electron volt ranges + + + align:start position:0% +high energy killer electron volt ranges +and I see Peaks there I can say straight + + align:start position:0% +and I see Peaks there I can say straight + + + align:start position:0% +and I see Peaks there I can say straight +away there is iron in my plasma there's + + align:start position:0% +away there is iron in my plasma there's + + + align:start position:0% +away there is iron in my plasma there's +tungsten in my plasma there's malum in + + align:start position:0% +tungsten in my plasma there's malum in + + + align:start position:0% +tungsten in my plasma there's malum in +my plasma and of course all of those + + align:start position:0% +my plasma and of course all of those + + + align:start position:0% +my plasma and of course all of those +impurities are radiating very strongly + + align:start position:0% +impurities are radiating very strongly + + + align:start position:0% +impurities are radiating very strongly +because these transitions are very + + align:start position:0% +because these transitions are very + + + align:start position:0% +because these transitions are very +strong and so that um really ruins your + + align:start position:0% +strong and so that um really ruins your + + + align:start position:0% +strong and so that um really ruins your +Power Balance reactor so a lot of + + align:start position:0% +Power Balance reactor so a lot of + + + align:start position:0% +Power Balance reactor so a lot of +spectroscopy early spectroscopy work at + + align:start position:0% +spectroscopy early spectroscopy work at + + + align:start position:0% +spectroscopy early spectroscopy work at +least in magnetic infi Fusion was + + align:start position:0% +least in magnetic infi Fusion was + + + align:start position:0% +least in magnetic infi Fusion was +looking for these signatures of + + align:start position:0% +looking for these signatures of + + + align:start position:0% +looking for these signatures of +impurities in the plasma here okay + + align:start position:0% +impurities in the plasma here okay + + + align:start position:0% +impurities in the plasma here okay +questions on all this the nure thing is + + align:start position:0% +questions on all this the nure thing is + + + align:start position:0% +questions on all this the nure thing is +basically knowing that K means + + align:start position:0% +basically knowing that K means + + + align:start position:0% +basically knowing that K means +transitions to one and Alpha and beta + + align:start position:0% +transitions to one and Alpha and beta + + + align:start position:0% +transitions to one and Alpha and beta +mean from the level above and the level + + align:start position:0% +mean from the level above and the level + + + align:start position:0% +mean from the level above and the level +above that and knowing that the K Alpha + + align:start position:0% +above that and knowing that the K Alpha + + + align:start position:0% +above that and knowing that the K Alpha +is much stronger than the others and + + align:start position:0% +is much stronger than the others and + + + align:start position:0% +is much stronger than the others and +maybe knowing that sometimes people were + + align:start position:0% +maybe knowing that sometimes people were + + + align:start position:0% +maybe knowing that sometimes people were +like this is a k Alpha transition in + + align:start position:0% +like this is a k Alpha transition in + + + align:start position:0% +like this is a k Alpha transition in +helium like aluminum and you're like ah + + align:start position:0% +helium like aluminum and you're like ah + + + align:start position:0% +helium like aluminum and you're like ah +cool um + + align:start position:0% +cool um + + + align:start position:0% +cool um +yeah right + + align:start position:0% +yeah right + + + align:start position:0% +yeah right +questions + + align:start position:0% + + + + align:start position:0% + +yes yeah I me absolutely brem stong is + + align:start position:0% +yes yeah I me absolutely brem stong is + + + align:start position:0% +yes yeah I me absolutely brem stong is +producing those wavelengths as well in + + align:start position:0% +producing those wavelengths as well in + + + align:start position:0% +producing those wavelengths as well in +general um but not lines so that's + + align:start position:0% +general um but not lines so that's + + + align:start position:0% +general um but not lines so that's +that's why they're so unique and you + + align:start position:0% +that's why they're so unique and you + + + align:start position:0% +that's why they're so unique and you +know maybe in some system you could have + + align:start position:0% +know maybe in some system you could have + + + align:start position:0% +know maybe in some system you could have +like synchron radiation or something + + align:start position:0% +like synchron radiation or something + + + align:start position:0% +like synchron radiation or something +like that or you know but in general + + align:start position:0% +like that or you know but in general + + + align:start position:0% +like that or you know but in general +these are very specific yeah and they + + align:start position:0% +these are very specific yeah and they + + + align:start position:0% +these are very specific yeah and they +they're slightly different energy so K + + align:start position:0% +they're slightly different energy so K + + + align:start position:0% +they're slightly different energy so K +Alpha for helium like is at a slightly + + align:start position:0% +Alpha for helium like is at a slightly + + + align:start position:0% +Alpha for helium like is at a slightly +higher energy than K Alpha for lithium + + align:start position:0% +higher energy than K Alpha for lithium + + + align:start position:0% +higher energy than K Alpha for lithium +like and so you may also then have + + align:start position:0% +like and so you may also then have + + + align:start position:0% +like and so you may also then have +the this is say these ones are the + + align:start position:0% +the this is say these ones are the + + + align:start position:0% +the this is say these ones are the +helium like and this is the K Alpha and + + align:start position:0% +helium like and this is the K Alpha and + + + align:start position:0% +helium like and this is the K Alpha and +the K beta the lithium like and then you + + align:start position:0% +the K beta the lithium like and then you + + + align:start position:0% +the K beta the lithium like and then you +can do your because you know exactly + + align:start position:0% +can do your because you know exactly + + + align:start position:0% +can do your because you know exactly +what these lines are because they're so + + align:start position:0% +what these lines are because they're so + + + align:start position:0% +what these lines are because they're so +specific you can do your line ratio + + align:start position:0% +specific you can do your line ratio + + + align:start position:0% +specific you can do your line ratio +trick that we used before and work out + + align:start position:0% +trick that we used before and work out + + + align:start position:0% +trick that we used before and work out +what the temperature is because you know + + align:start position:0% +what the temperature is because you know + + + align:start position:0% +what the temperature is because you know +this is a lower ionization State than + + align:start position:0% +this is a lower ionization State than + + + align:start position:0% +this is a lower ionization State than +this + + align:start position:0% +this + + + align:start position:0% +this +one yeah obviously if you are fully + + align:start position:0% +one yeah obviously if you are fully + + + align:start position:0% +one yeah obviously if you are fully +stripped if you have got to a + + align:start position:0% +stripped if you have got to a + + + align:start position:0% +stripped if you have got to a +temperature where there are no electrons + + align:start position:0% +temperature where there are no electrons + + + align:start position:0% +temperature where there are no electrons +left in your system you no longer have + + align:start position:0% +left in your system you no longer have + + + align:start position:0% +left in your system you no longer have +the line you would only get a line from + + align:start position:0% +the line you would only get a line from + + + align:start position:0% +the line you would only get a line from +recombination but the recombination has + + align:start position:0% +recombination but the recombination has + + + align:start position:0% +recombination but the recombination has +a spectrum as we talked about was an + + align:start position:0% +a spectrum as we talked about was an + + + align:start position:0% +a spectrum as we talked about was an +edge but still a spectrum + + align:start position:0% +edge but still a spectrum + + + align:start position:0% +edge but still a spectrum +yeah + + align:start position:0% + + + + align:start position:0% + +no I believe that is + + align:start position:0% +no I believe that is + + + align:start position:0% +no I believe that is +separate yeah I I actually been a while + + align:start position:0% +separate yeah I I actually been a while + + + align:start position:0% +separate yeah I I actually been a while +since I reminded myself what lime Al was + + align:start position:0% +since I reminded myself what lime Al was + + + align:start position:0% +since I reminded myself what lime Al was +that's the one that's 121 n right oh + + align:start position:0% +that's the one that's 121 n right oh + + + align:start position:0% +that's the one that's 121 n right oh +okay any astrophysicist no okay yeah + + align:start position:0% +okay any astrophysicist no okay yeah + + + align:start position:0% +okay any astrophysicist no okay yeah +that's like a UV + + align:start position:0% +that's like a UV + + + align:start position:0% +that's like a UV +line is there a chance that it is + + align:start position:0% +line is there a chance that it is + + + align:start position:0% +line is there a chance that it is +related to these yeah I think it is an + + align:start position:0% +related to these yeah I think it is an + + + align:start position:0% +related to these yeah I think it is an +x-ray line but I can't remember the most + + align:start position:0% +x-ray line but I can't remember the most + + + align:start position:0% +x-ray line but I can't remember the most +common + + align:start position:0% +common + + + align:start position:0% +common +one makes me think it's y I thought it + + align:start position:0% + + + + align:start position:0% + +called the Lyman Lyman series or lman + + align:start position:0% +called the Lyman Lyman series or lman + + + align:start position:0% +called the Lyman Lyman series or lman +that's a balma series what a Lyman + + align:start position:0% +that's a balma series what a Lyman + + + align:start position:0% +that's a balma series what a Lyman +series okay so maybe in hydrogen they + + align:start position:0% +series okay so maybe in hydrogen they + + + align:start position:0% +series okay so maybe in hydrogen they +have separate names that correspond to + + align:start position:0% +have separate names that correspond to + + + align:start position:0% +have separate names that correspond to +these um and I think historically right + + align:start position:0% +these um and I think historically right + + + align:start position:0% +these um and I think historically right +people were doing uh spectroscopy on + + align:start position:0% +people were doing uh spectroscopy on + + + align:start position:0% +people were doing uh spectroscopy on +astrophysical bodies which the first + + align:start position:0% +astrophysical bodies which the first + + + align:start position:0% +astrophysical bodies which the first +bodies we could look at that had these + + align:start position:0% +bodies we could look at that had these + + + align:start position:0% +bodies we could look at that had these +temperatures right so people were not + + align:start position:0% +temperatures right so people were not + + + align:start position:0% +temperatures right so people were not +doing spectroscopy on copper straight + + align:start position:0% +doing spectroscopy on copper straight + + + align:start position:0% +doing spectroscopy on copper straight +away but if you point your spectrometer + + align:start position:0% +away but if you point your spectrometer + + + align:start position:0% +away but if you point your spectrometer +at the sun then you can get these Alpha + + align:start position:0% +at the sun then you can get these Alpha + + + align:start position:0% +at the sun then you can get these Alpha +these Lyman ah Lyman series and balma + + align:start position:0% +these Lyman ah Lyman series and balma + + + align:start position:0% +these Lyman ah Lyman series and balma +series I'll look that up good question + + align:start position:0% +series I'll look that up good question + + + align:start position:0% +series I'll look that up good question +any questions online or comments if you + + align:start position:0% +any questions online or comments if you + + + align:start position:0% +any questions online or comments if you +know anything about Lyman series and + + align:start position:0% +know anything about Lyman series and + + + align:start position:0% +know anything about Lyman series and +balma + + align:start position:0% + + + + align:start position:0% + +series okay we can use this in Reverse + + align:start position:0% +series okay we can use this in Reverse + + + align:start position:0% +series okay we can use this in Reverse +to design filters for our x-ray systems + + align:start position:0% +to design filters for our x-ray systems + + + align:start position:0% +to design filters for our x-ray systems +so we often want to be able to measure + + align:start position:0% +so we often want to be able to measure + + + align:start position:0% +so we often want to be able to measure +just the light in a certain region here + + align:start position:0% +just the light in a certain region here + + + align:start position:0% +just the light in a certain region here +so this would be like taking a picture + + align:start position:0% +so this would be like taking a picture + + + align:start position:0% +so this would be like taking a picture +of just the X-rays and so we want to be + + align:start position:0% +of just the X-rays and so we want to be + + + align:start position:0% +of just the X-rays and so we want to be +able to filter out all the other light + + align:start position:0% +able to filter out all the other light + + + align:start position:0% +able to filter out all the other light +and just use uh the light in this + + align:start position:0% + + + + align:start position:0% + +region so this is looking at x-ray + + align:start position:0% +region so this is looking at x-ray + + + align:start position:0% +region so this is looking at x-ray +filters so a filter is a + + align:start position:0% +filters so a filter is a + + + align:start position:0% +filters so a filter is a +solid object it's usually a thin foil + + align:start position:0% +solid object it's usually a thin foil + + + align:start position:0% +solid object it's usually a thin foil +made out of some metal or or some + + align:start position:0% +made out of some metal or or some + + + align:start position:0% +made out of some metal or or some +nonmetal here um and the idea of the + + align:start position:0% +nonmetal here um and the idea of the + + + align:start position:0% +nonmetal here um and the idea of the +filters is that we still have these + + align:start position:0% +filters is that we still have these + + + align:start position:0% +filters is that we still have these +different energy levels here n equals 1 + + align:start position:0% +different energy levels here n equals 1 + + + align:start position:0% +different energy levels here n equals 1 +Nal 2 nals 3 and four but now this is + + align:start position:0% +Nal 2 nals 3 and four but now this is + + + align:start position:0% +Nal 2 nals 3 and four but now this is +for + + align:start position:0% +for + + + align:start position:0% +for +um Z equals zero so this is for some + + align:start position:0% +um Z equals zero so this is for some + + + align:start position:0% +um Z equals zero so this is for some +solid like a lump of tungen or something + + align:start position:0% +solid like a lump of tungen or something + + + align:start position:0% +solid like a lump of tungen or something +like that and then if we have a photon + + align:start position:0% +like that and then if we have a photon + + + align:start position:0% +like that and then if we have a photon +coming in if there's a possibility that + + align:start position:0% +coming in if there's a possibility that + + + align:start position:0% +coming in if there's a possibility that +Photon has enough energy H bar Omega to + + align:start position:0% +Photon has enough energy H bar Omega to + + + align:start position:0% +Photon has enough energy H bar Omega to +excite an electron from one of the inner + + align:start position:0% +excite an electron from one of the inner + + + align:start position:0% +excite an electron from one of the inner +shells from one and two and three then + + align:start position:0% +shells from one and two and three then + + + align:start position:0% +shells from one and two and three then +that process is now favorable it's + + align:start position:0% +that process is now favorable it's + + + align:start position:0% +that process is now favorable it's +likely that that Photon will be absorbed + + align:start position:0% +likely that that Photon will be absorbed + + + align:start position:0% +likely that that Photon will be absorbed +if it doesn't match with any of these + + align:start position:0% +if it doesn't match with any of these + + + align:start position:0% +if it doesn't match with any of these +band gaps or any of these transitions + + align:start position:0% +band gaps or any of these transitions + + + align:start position:0% +band gaps or any of these transitions +then the photon will go through but if + + align:start position:0% +then the photon will go through but if + + + align:start position:0% +then the photon will go through but if +it does match then it will get + + align:start position:0% +it does match then it will get + + + align:start position:0% +it does match then it will get +absorbed so what we see in our + + align:start position:0% +absorbed so what we see in our + + + align:start position:0% +absorbed so what we see in our +absorption plot for a filter + + align:start position:0% +absorption plot for a filter + + + align:start position:0% +absorption plot for a filter +so this is that quantity Alpha the + + align:start position:0% +so this is that quantity Alpha the + + + align:start position:0% +so this is that quantity Alpha the +opacity as a function of + + align:start position:0% +opacity as a function of + + + align:start position:0% +opacity as a function of +frequency this we see a series + + align:start position:0% + + + + align:start position:0% + +of what are called edges here so this is + + align:start position:0% +of what are called edges here so this is + + + align:start position:0% +of what are called edges here so this is +the L + + align:start position:0% +the L + + + align:start position:0% +the L +Edge and this is the K + + align:start position:0% + + + + align:start position:0% + +Edge and um what you get is your lines + + align:start position:0% +Edge and um what you get is your lines + + + align:start position:0% +Edge and um what you get is your lines +corresponding + + align:start position:0% + + + + align:start position:0% + +to your frequencies corresponding to K + + align:start position:0% +to your frequencies corresponding to K + + + align:start position:0% +to your frequencies corresponding to K +Alpha K beta all the way up to the + + align:start position:0% +Alpha K beta all the way up to the + + + align:start position:0% +Alpha K beta all the way up to the +highest K which is ionizing from + + align:start position:0% +highest K which is ionizing from + + + align:start position:0% +highest K which is ionizing from +whatever the highest occupied state is + + align:start position:0% +whatever the highest occupied state is + + + align:start position:0% +whatever the highest occupied state is +up into the Continuum and same here you + + align:start position:0% +up into the Continuum and same here you + + + align:start position:0% +up into the Continuum and same here you +get trying to space these + + align:start position:0% +get trying to space these + + + align:start position:0% +get trying to space these +parabolically L Alpha L + + align:start position:0% + + + + align:start position:0% + +data so effectively you have a sudden + + align:start position:0% +data so effectively you have a sudden + + + align:start position:0% +data so effectively you have a sudden +increase in absorption whenever uh it is + + align:start position:0% +increase in absorption whenever uh it is + + + align:start position:0% +increase in absorption whenever uh it is +possible to do this ionization if you + + align:start position:0% +possible to do this ionization if you + + + align:start position:0% +possible to do this ionization if you +have done the homework yet and you've + + align:start position:0% +have done the homework yet and you've + + + align:start position:0% +have done the homework yet and you've +looked at some of the other filters you + + align:start position:0% +looked at some of the other filters you + + + align:start position:0% +looked at some of the other filters you +can generate on the hankki website you + + align:start position:0% +can generate on the hankki website you + + + align:start position:0% +can generate on the hankki website you +will have noticed these really weird + + align:start position:0% +will have noticed these really weird + + + align:start position:0% +will have noticed these really weird +absorption features hanky normally gives + + align:start position:0% +absorption features hanky normally gives + + + align:start position:0% +absorption features hanky normally gives +you transmission uh and so you will have + + align:start position:0% +you transmission uh and so you will have + + + align:start position:0% +you transmission uh and so you will have +seen one over this the absorption is one + + align:start position:0% +seen one over this the absorption is one + + + align:start position:0% +seen one over this the absorption is one +over the transmission but you will have + + align:start position:0% +over the transmission but you will have + + + align:start position:0% +over the transmission but you will have +noticed these really sharp edges that's + + align:start position:0% +noticed these really sharp edges that's + + + align:start position:0% +noticed these really sharp edges that's +not a numerical problem when you first + + align:start position:0% +not a numerical problem when you first + + + align:start position:0% +not a numerical problem when you first +see it you think oh the code is broken + + align:start position:0% +see it you think oh the code is broken + + + align:start position:0% +see it you think oh the code is broken +here no these are correspond to these + + align:start position:0% +here no these are correspond to these + + + align:start position:0% +here no these are correspond to these +very strong absorption edges here so if + + align:start position:0% +very strong absorption edges here so if + + + align:start position:0% +very strong absorption edges here so if +you have a + + align:start position:0% + + + + align:start position:0% + +spectrum that has some lines in it and + + align:start position:0% +spectrum that has some lines in it and + + + align:start position:0% +spectrum that has some lines in it and +you put that Spectrum through this + + align:start position:0% +you put that Spectrum through this + + + align:start position:0% +you put that Spectrum through this +filter this filter would cut out for + + align:start position:0% +filter this filter would cut out for + + + align:start position:0% +filter this filter would cut out for +example this highest energy line here + + align:start position:0% +example this highest energy line here + + + align:start position:0% +example this highest energy line here +and You' just be left the Spectrum in + + align:start position:0% +and You' just be left the Spectrum in + + + align:start position:0% +and You' just be left the Spectrum in +this + + align:start position:0% +this + + + align:start position:0% +this +region so this is how you use x-rays to + + align:start position:0% +region so this is how you use x-rays to + + + align:start position:0% +region so this is how you use x-rays to +do + + align:start position:0% + + + + align:start position:0% + +filtering oh + + align:start position:0% +filtering oh + + + align:start position:0% +filtering oh +okay fine questions on + + align:start position:0% +okay fine questions on + + + align:start position:0% +okay fine questions on +that + + align:start position:0% +that + + + align:start position:0% +that +and the position of these edges depends + + align:start position:0% +and the position of these edges depends + + + align:start position:0% +and the position of these edges depends +on the element so if I use an aluminium + + align:start position:0% +on the element so if I use an aluminium + + + align:start position:0% +on the element so if I use an aluminium +filter or a Tungsten filter or a plastic + + align:start position:0% +filter or a Tungsten filter or a plastic + + + align:start position:0% +filter or a Tungsten filter or a plastic +filter it'll have edges in different + + align:start position:0% +filter it'll have edges in different + + + align:start position:0% +filter it'll have edges in different +places and so by using different filters + + align:start position:0% +places and so by using different filters + + + align:start position:0% +places and so by using different filters +I can image different parts of the + + align:start position:0% +I can image different parts of the + + + align:start position:0% +I can image different parts of the +spectrum so we'll talk about xray + + align:start position:0% +spectrum so we'll talk about xray + + + align:start position:0% +spectrum so we'll talk about xray +Imaging in a moment + + align:start position:0% + + + + align:start position:0% + +yeah not at all yeah just photo AB + + align:start position:0% + + + + align:start position:0% + +yeah yeah so that's a bit that does + + align:start position:0% +yeah yeah so that's a bit that does + + + align:start position:0% +yeah yeah so that's a bit that does +yeah yeah that's the sort of uh you need + + align:start position:0% +yeah yeah that's the sort of uh you need + + + align:start position:0% +yeah yeah that's the sort of uh you need +Quantum and treating the photon as a as + + align:start position:0% +Quantum and treating the photon as a as + + + align:start position:0% +Quantum and treating the photon as a as +a as a wave in order to get or you you + + align:start position:0% +a as a wave in order to get or you you + + + align:start position:0% +a as a wave in order to get or you you +need a Quantum treatment of it in order + + align:start position:0% +need a Quantum treatment of it in order + + + align:start position:0% +need a Quantum treatment of it in order +to get this roll off here yeah my + + align:start position:0% +to get this roll off here yeah my + + + align:start position:0% +to get this roll off here yeah my +explanation only covers why there's a + + align:start position:0% +explanation only covers why there's a + + + align:start position:0% +explanation only covers why there's a +sharp edge I haven't seen a nice + + align:start position:0% +sharp edge I haven't seen a nice + + + align:start position:0% +sharp edge I haven't seen a nice +intuitive explanation for this roll off + + align:start position:0% +intuitive explanation for this roll off + + + align:start position:0% +intuitive explanation for this roll off +after um but all all materials at high + + align:start position:0% +after um but all all materials at high + + + align:start position:0% +after um but all all materials at high +enough energies no matter what their + + align:start position:0% +enough energies no matter what their + + + align:start position:0% +enough energies no matter what their +absorption goes down to zero right so + + align:start position:0% +absorption goes down to zero right so + + + align:start position:0% +absorption goes down to zero right so +gamma rays will get through you know + + align:start position:0% +gamma rays will get through you know + + + align:start position:0% +gamma rays will get through you know +anything eventually yeah um + + align:start position:0% +anything eventually yeah um + + + align:start position:0% +anything eventually yeah um +Professor oh sorry I'm just gonna answer + + align:start position:0% +Professor oh sorry I'm just gonna answer + + + align:start position:0% +Professor oh sorry I'm just gonna answer +another question Jacob first and then + + align:start position:0% +another question Jacob first and then + + + align:start position:0% +another question Jacob first and then +I'll get back to you so the question was + + align:start position:0% +I'll get back to you so the question was + + + align:start position:0% +I'll get back to you so the question was +why the edges get taller and taller I + + align:start position:0% +why the edges get taller and taller I + + + align:start position:0% +why the edges get taller and taller I +think it's due to the likelihood of this + + align:start position:0% +think it's due to the likelihood of this + + + align:start position:0% +think it's due to the likelihood of this +interaction um but I'm not sure yeah + + align:start position:0% +interaction um but I'm not sure yeah + + + align:start position:0% +interaction um but I'm not sure yeah +sorry Jacob your + + align:start position:0% +sorry Jacob your + + + align:start position:0% +sorry Jacob your +question how do you design a material to + + align:start position:0% +question how do you design a material to + + + align:start position:0% +question how do you design a material to +uh specifically change out like take out + + align:start position:0% +uh specifically change out like take out + + + align:start position:0% +uh specifically change out like take out +a certain like the K Edge like or the L + + align:start position:0% +a certain like the K Edge like or the L + + + align:start position:0% +a certain like the K Edge like or the L +Edge you don't design a material you + + align:start position:0% +Edge you don't design a material you + + + align:start position:0% +Edge you don't design a material you +have a look and see what materials are + + align:start position:0% +have a look and see what materials are + + + align:start position:0% +have a look and see what materials are +available right yeah I mean how choose a + + align:start position:0% +available right yeah I mean how choose a + + + align:start position:0% +available right yeah I mean how choose a +material how do you choose a material + + align:start position:0% +material how do you choose a material + + + align:start position:0% +material how do you choose a material +well I I choose it by going on the hanky + + align:start position:0% +well I I choose it by going on the hanky + + + align:start position:0% +well I I choose it by going on the hanky +database and I generate these curves and + + align:start position:0% +database and I generate these curves and + + + align:start position:0% +database and I generate these curves and +I see what they are um so and I guess if + + align:start position:0% +I see what they are um so and I guess if + + + align:start position:0% +I see what they are um so and I guess if +you're very experienced you just know + + align:start position:0% +you're very experienced you just know + + + align:start position:0% +you're very experienced you just know +for example that this kedge is at 1.6 KV + + align:start position:0% +for example that this kedge is at 1.6 KV + + + align:start position:0% +for example that this kedge is at 1.6 KV +for aluminum and if you're trying to + + align:start position:0% +for aluminum and if you're trying to + + + align:start position:0% +for aluminum and if you're trying to +measure photons of energies below that + + align:start position:0% +measure photons of energies below that + + + align:start position:0% +measure photons of energies below that +then 1.6 this aluminum is quite a good + + align:start position:0% +then 1.6 this aluminum is quite a good + + + align:start position:0% +then 1.6 this aluminum is quite a good +filter um but you can't you can't + + align:start position:0% +filter um but you can't you can't + + + align:start position:0% +filter um but you can't you can't +engineer a material to have khes it's an + + align:start position:0% +engineer a material to have khes it's an + + + align:start position:0% +engineer a material to have khes it's an +atomic process so it really depends on + + align:start position:0% +atomic process so it really depends on + + + align:start position:0% +atomic process so it really depends on +the elements if for example you have a + + align:start position:0% +the elements if for example you have a + + + align:start position:0% +the elements if for example you have a +filter made out of a mixture of two + + align:start position:0% +filter made out of a mixture of two + + + align:start position:0% +filter made out of a mixture of two +elements + + align:start position:0% +elements + + + align:start position:0% +elements +then it's just the combination of the + + align:start position:0% +then it's just the combination of the + + + align:start position:0% +then it's just the combination of the +absorption for those two different + + align:start position:0% +absorption for those two different + + + align:start position:0% +absorption for those two different +elements so yeah and you have to get the + + align:start position:0% +elements so yeah and you have to get the + + + align:start position:0% +elements so yeah and you have to get the +L Edge if you get the K Edge right or + + align:start position:0% +L Edge if you get the K Edge right or + + + align:start position:0% +L Edge if you get the K Edge right or +can you just get no no the L Edge will + + align:start position:0% +can you just get no no the L Edge will + + + align:start position:0% +can you just get no no the L Edge will +always be there as well and and the M + + align:start position:0% +always be there as well and and the M + + + align:start position:0% +always be there as well and and the M +Edge and so on but down to lower and + + align:start position:0% +Edge and so on but down to lower and + + + align:start position:0% +Edge and so on but down to lower and +lower energies right so they may not be + + align:start position:0% +lower energies right so they may not be + + + align:start position:0% +lower energies right so they may not be +interesting for your bit of the + + align:start position:0% +interesting for your bit of the + + + align:start position:0% +interesting for your bit of the +spectrum okay so you'll still see the + + align:start position:0% +spectrum okay so you'll still see the + + + align:start position:0% +spectrum okay so you'll still see the +bottom ones but you just know that + + align:start position:0% +bottom ones but you just know that + + + align:start position:0% +bottom ones but you just know that +they're too low of an energy to if you + + align:start position:0% +they're too low of an energy to if you + + + align:start position:0% +they're too low of an energy to if you +think your spectrum looks like this and + + align:start position:0% +think your spectrum looks like this and + + + align:start position:0% +think your spectrum looks like this and +you know that there's no interesting + + align:start position:0% +you know that there's no interesting + + + align:start position:0% +you know that there's no interesting +features down here it's just brm stong + + align:start position:0% +features down here it's just brm stong + + + align:start position:0% +features down here it's just brm stong +with very bright lines up at high + + align:start position:0% +with very bright lines up at high + + + align:start position:0% +with very bright lines up at high +energies then you don't really care what + + align:start position:0% +energies then you don't really care what + + + align:start position:0% +energies then you don't really care what +the structure is down here because when + + align:start position:0% +the structure is down here because when + + + align:start position:0% +the structure is down here because when +you multiply the transmission via your + + align:start position:0% +you multiply the transmission via your + + + align:start position:0% +you multiply the transmission via your +spectrum there'll be like little + + align:start position:0% +spectrum there'll be like little + + + align:start position:0% +spectrum there'll be like little +fluctuations down here but you don't + + align:start position:0% +fluctuations down here but you don't + + + align:start position:0% +fluctuations down here but you don't +care about them because your spectrum is + + align:start position:0% +care about them because your spectrum is + + + align:start position:0% +care about them because your spectrum is +going to be dominated by these lines you + + align:start position:0% +going to be dominated by these lines you + + + align:start position:0% +going to be dominated by these lines you +think okay makes + + align:start position:0% +think okay makes + + + align:start position:0% +think okay makes +sense other + + align:start position:0% +sense other + + + align:start position:0% +sense other +question okay let's talk about x-ray + + align:start position:0% +question okay let's talk about x-ray + + + align:start position:0% +question okay let's talk about x-ray +Imaging so why we might want to use a + + align:start position:0% +Imaging so why we might want to use a + + + align:start position:0% +Imaging so why we might want to use a +filter obviously if we're doing + + align:start position:0% +filter obviously if we're doing + + + align:start position:0% +filter obviously if we're doing +spectroscopy we don't care about the + + align:start position:0% +spectroscopy we don't care about the + + + align:start position:0% +spectroscopy we don't care about the +filters because we can just do + + align:start position:0% +filters because we can just do + + + align:start position:0% +filters because we can just do +spectroscopy and we can see where the + + align:start position:0% +spectroscopy and we can see where the + + + align:start position:0% +spectroscopy and we can see where the +lines are but if you don't want to do + + align:start position:0% +lines are but if you don't want to do + + + align:start position:0% +lines are but if you don't want to do +spectroscopy and you want to make an + + align:start position:0% +spectroscopy and you want to make an + + + align:start position:0% +spectroscopy and you want to make an +image you're going to need some of these + + align:start position:0% +image you're going to need some of these + + + align:start position:0% +image you're going to need some of these +filters so that you know what energies + + align:start position:0% +filters so that you know what energies + + + align:start position:0% +filters so that you know what energies +you're looking at so this is x-ray + + align:start position:0% + + + + align:start position:0% + +image so one of the facts about x-ray + + align:start position:0% +image so one of the facts about x-ray + + + align:start position:0% +image so one of the facts about x-ray +Imaging is that there are no + + align:start position:0% + + + + align:start position:0% + +lenses and that is a consequence of the + + align:start position:0% +lenses and that is a consequence of the + + + align:start position:0% +lenses and that is a consequence of the +fact that the refractive index is rough + + align:start position:0% +fact that the refractive index is rough + + + align:start position:0% +fact that the refractive index is rough +one for X-rays and lenses work on having + + align:start position:0% +one for X-rays and lenses work on having + + + align:start position:0% +one for X-rays and lenses work on having +a difference in refractive index from + + align:start position:0% +a difference in refractive index from + + + align:start position:0% +a difference in refractive index from +Air so if your refractive index of all + + align:start position:0% +Air so if your refractive index of all + + + align:start position:0% +Air so if your refractive index of all +your materials is about one you can no + + align:start position:0% +your materials is about one you can no + + + align:start position:0% +your materials is about one you can no +longer bend the Rays so the simplest + + align:start position:0% +longer bend the Rays so the simplest + + + align:start position:0% +longer bend the Rays so the simplest +thing that you can do for x-ray Imaging + + align:start position:0% +thing that you can do for x-ray Imaging + + + align:start position:0% +thing that you can do for x-ray Imaging +is called pinhole + + align:start position:0% + + + + align:start position:0% + +Imaging pinhole Imaging is what the + + align:start position:0% +Imaging pinhole Imaging is what the + + + align:start position:0% +Imaging pinhole Imaging is what the +first cameras for visible light used as + + align:start position:0% +first cameras for visible light used as + + + align:start position:0% +first cameras for visible light used as +well you have your object which in this + + align:start position:0% +well you have your object which in this + + + align:start position:0% +well you have your object which in this +case I'm drawing as like a angle with + + align:start position:0% +case I'm drawing as like a angle with + + + align:start position:0% +case I'm drawing as like a angle with +very little symmetry for reasons that + + align:start position:0% +very little symmetry for reasons that + + + align:start position:0% +very little symmetry for reasons that +might become apparent later + + align:start position:0% +might become apparent later + + + align:start position:0% +might become apparent later +on you have your PIN hole which is a + + align:start position:0% +on you have your PIN hole which is a + + + align:start position:0% +on you have your PIN hole which is a +little + + align:start position:0% +little + + + align:start position:0% +little +opening of diameter D in some plate + + align:start position:0% +opening of diameter D in some plate + + + align:start position:0% +opening of diameter D in some plate +which is otherwise completely + + align:start position:0% +which is otherwise completely + + + align:start position:0% +which is otherwise completely +absorbing and then this is just + + align:start position:0% +absorbing and then this is just + + + align:start position:0% +absorbing and then this is just +geometric optics so you trace the Rays + + align:start position:0% +geometric optics so you trace the Rays + + + align:start position:0% +geometric optics so you trace the Rays +of light from the corners of your + + align:start position:0% +of light from the corners of your + + + align:start position:0% +of light from the corners of your +object through the pin hole and if you + + align:start position:0% +object through the pin hole and if you + + + align:start position:0% +object through the pin hole and if you +get it right and I'm probably going to + + align:start position:0% +get it right and I'm probably going to + + + align:start position:0% +get it right and I'm probably going to +get it wrong you get an object which is + + align:start position:0% +get it wrong you get an object which is + + + align:start position:0% +get it wrong you get an object which is +inverted from the one that you started + + align:start position:0% +inverted from the one that you started + + + align:start position:0% +inverted from the one that you started +with so it's upside down and it's it's + + align:start position:0% +with so it's upside down and it's it's + + + align:start position:0% +with so it's upside down and it's it's +flipped up down and flipped left right + + align:start position:0% +flipped up down and flipped left right + + + align:start position:0% +flipped up down and flipped left right +as + + align:start position:0% +as + + + align:start position:0% +as +well that's not usually a big problem + + align:start position:0% +well that's not usually a big problem + + + align:start position:0% +well that's not usually a big problem +you can usually work + + align:start position:0% +you can usually work + + + align:start position:0% +you can usually work +out what's going on the object will also + + align:start position:0% +out what's going on the object will also + + + align:start position:0% +out what's going on the object will also +be magnified so there's some distance U + + align:start position:0% +be magnified so there's some distance U + + + align:start position:0% +be magnified so there's some distance U +between your object and your pinhole and + + align:start position:0% +between your object and your pinhole and + + + align:start position:0% +between your object and your pinhole and +some distance V between your pinhole and + + align:start position:0% +some distance V between your pinhole and + + + align:start position:0% +some distance V between your pinhole and +your detector could be film or some + + align:start position:0% +your detector could be film or some + + + align:start position:0% +your detector could be film or some +camera and so this is also + + align:start position:0% +camera and so this is also + + + align:start position:0% +camera and so this is also +magnified + + align:start position:0% + + + + align:start position:0% + +by the ratio of V upon U and you can + + align:start position:0% +by the ratio of V upon U and you can + + + align:start position:0% +by the ratio of V upon U and you can +check that out by drawing some lines for + + align:start position:0% +check that out by drawing some lines for + + + align:start position:0% +check that out by drawing some lines for +yourself and you'll see very quickly + + align:start position:0% +yourself and you'll see very quickly + + + align:start position:0% +yourself and you'll see very quickly +from some geometric arguments and + + align:start position:0% +from some geometric arguments and + + + align:start position:0% +from some geometric arguments and +similarity of triangles that you get out + + align:start position:0% +similarity of triangles that you get out + + + align:start position:0% +similarity of triangles that you get out +this magnification here but this will + + align:start position:0% +this magnification here but this will + + + align:start position:0% +this magnification here but this will +also be blurred so you'll not get a + + align:start position:0% +also be blurred so you'll not get a + + + align:start position:0% +also be blurred so you'll not get a +perfect image and it will be blurred by + + align:start position:0% +perfect image and it will be blurred by + + + align:start position:0% +perfect image and it will be blurred by +two effects the first one is geometric + + align:start position:0% +two effects the first one is geometric + + + align:start position:0% +two effects the first one is geometric +blurring + + align:start position:0% + + + + align:start position:0% + +the geometric blurring is a function of + + align:start position:0% +the geometric blurring is a function of + + + align:start position:0% +the geometric blurring is a function of +the fact that you have to have some + + align:start position:0% +the fact that you have to have some + + + align:start position:0% +the fact that you have to have some +finite sized pin hole here ideally this + + align:start position:0% +finite sized pin hole here ideally this + + + align:start position:0% +finite sized pin hole here ideally this +pin hole would be infantes small and + + align:start position:0% +pin hole would be infantes small and + + + align:start position:0% +pin hole would be infantes small and +then all of your rays of light would + + align:start position:0% +then all of your rays of light would + + + align:start position:0% +then all of your rays of light would +have to go through the pinhole to make + + align:start position:0% +have to go through the pinhole to make + + + align:start position:0% +have to go through the pinhole to make +it to the detector in practice if your + + align:start position:0% +it to the detector in practice if your + + + align:start position:0% +it to the detector in practice if your +PIN hole is very very small then you + + align:start position:0% +PIN hole is very very small then you + + + align:start position:0% +PIN hole is very very small then you +don't get any light through at all and + + align:start position:0% +don't get any light through at all and + + + align:start position:0% +don't get any light through at all and +you don't get a very bright image so you + + align:start position:0% +you don't get a very bright image so you + + + align:start position:0% +you don't get a very bright image so you +have to increase the size of your + + align:start position:0% +have to increase the size of your + + + align:start position:0% +have to increase the size of your +pinhole to get enough light through to + + align:start position:0% +pinhole to get enough light through to + + + align:start position:0% +pinhole to get enough light through to +make an image the D trick blurring is + + align:start position:0% +make an image the D trick blurring is + + + align:start position:0% +make an image the D trick blurring is +effectively if you + + align:start position:0% +effectively if you + + + align:start position:0% +effectively if you +think that your object consists of two + + align:start position:0% +think that your object consists of two + + + align:start position:0% +think that your object consists of two +little right blobs like this so you're + + align:start position:0% +little right blobs like this so you're + + + align:start position:0% +little right blobs like this so you're +you're looking at it it's just two + + align:start position:0% +you're looking at it it's just two + + + align:start position:0% +you're looking at it it's just two +little LEDs like that the projection of + + align:start position:0% +little LEDs like that the projection of + + + align:start position:0% +little LEDs like that the projection of +those dots say a DOT here and a DOT here + + align:start position:0% +those dots say a DOT here and a DOT here + + + align:start position:0% +those dots say a DOT here and a DOT here +through the pin + + align:start position:0% +through the pin + + + align:start position:0% +through the pin +hole I draw one of + + align:start position:0% +hole I draw one of + + + align:start position:0% +hole I draw one of +these to the top side of the pin hole + + align:start position:0% +these to the top side of the pin hole + + + align:start position:0% +these to the top side of the pin hole +and one of them to the bottom side of + + align:start position:0% +and one of them to the bottom side of + + + align:start position:0% +and one of them to the bottom side of +the pin hole so if this is just a + + align:start position:0% +the pin hole so if this is just a + + + align:start position:0% +the pin hole so if this is just a +missing light uniformly in 4 Pi St + + align:start position:0% +missing light uniformly in 4 Pi St + + + align:start position:0% +missing light uniformly in 4 Pi St +radian then it will project a circle + + align:start position:0% +radian then it will project a circle + + + align:start position:0% +radian then it will project a circle +through here so we'll end up not with + + align:start position:0% +through here so we'll end up not with + + + align:start position:0% +through here so we'll end up not with +two dots but with two circles so this is + + align:start position:0% +two dots but with two circles so this is + + + align:start position:0% +two dots but with two circles so this is +purely geometric I'm just using Ray + + align:start position:0% +purely geometric I'm just using Ray + + + align:start position:0% +purely geometric I'm just using Ray +Optics here I don't need to think about + + align:start position:0% +Optics here I don't need to think about + + + align:start position:0% +Optics here I don't need to think about +waves whatsoever and the diameter of + + align:start position:0% +waves whatsoever and the diameter of + + + align:start position:0% +waves whatsoever and the diameter of +these circles here is going to be equal + + align:start position:0% +these circles here is going to be equal + + + align:start position:0% +these circles here is going to be equal +to m + one times the pin hole size so we + + align:start position:0% +to m + one times the pin hole size so we + + + align:start position:0% +to m + one times the pin hole size so we +can change how much this blur occurs by + + align:start position:0% +can change how much this blur occurs by + + + align:start position:0% +can change how much this blur occurs by +changing our magnification and also by + + align:start position:0% +changing our magnification and also by + + + align:start position:0% +changing our magnification and also by +changing the pinhole and in the limit + + align:start position:0% +changing the pinhole and in the limit + + + align:start position:0% +changing the pinhole and in the limit +but our pinhole size becomes very small + + align:start position:0% +but our pinhole size becomes very small + + + align:start position:0% +but our pinhole size becomes very small +our blur also becomes very small and we + + align:start position:0% +our blur also becomes very small and we + + + align:start position:0% +our blur also becomes very small and we +can resolve Point objects again but like + + align:start position:0% +can resolve Point objects again but like + + + align:start position:0% +can resolve Point objects again but like +I + + align:start position:0% +I + + + align:start position:0% +I +said we + + align:start position:0% +said we + + + align:start position:0% +said we +need well if we have a very small + + align:start position:0% +need well if we have a very small + + + align:start position:0% +need well if we have a very small +pinhole diameter then we have no + + align:start position:0% +pinhole diameter then we have no + + + align:start position:0% +pinhole diameter then we have no +light so there's a tradeoff here and if + + align:start position:0% +light so there's a tradeoff here and if + + + align:start position:0% +light so there's a tradeoff here and if +you do photography and you're aware of + + align:start position:0% +you do photography and you're aware of + + + align:start position:0% +you do photography and you're aware of +like f numbers and things like that some + + align:start position:0% +like f numbers and things like that some + + + align:start position:0% +like f numbers and things like that some +of this may be very familiar to you but + + align:start position:0% +of this may be very familiar to you but + + + align:start position:0% +of this may be very familiar to you but +for those of you who don't I think this + + align:start position:0% +for those of you who don't I think this + + + align:start position:0% +for those of you who don't I think this +treatment is valid there's another limit + + align:start position:0% +treatment is valid there's another limit + + + align:start position:0% +treatment is valid there's another limit +which is the defraction + + align:start position:0% + + + + align:start position:0% + +limit and this is where we need to take + + align:start position:0% +limit and this is where we need to take + + + align:start position:0% +limit and this is where we need to take +the wave nature of light into + + align:start position:0% +the wave nature of light into + + + align:start position:0% +the wave nature of light into +account so we have our little pin hole + + align:start position:0% +account so we have our little pin hole + + + align:start position:0% +account so we have our little pin hole +again + + align:start position:0% +again + + + align:start position:0% +again +here but we know from hen's principle if + + align:start position:0% +here but we know from hen's principle if + + + align:start position:0% +here but we know from hen's principle if +we got some wave fronts coming in like + + align:start position:0% +we got some wave fronts coming in like + + + align:start position:0% +we got some wave fronts coming in like +this every point on the wavefront is a + + align:start position:0% +this every point on the wavefront is a + + + align:start position:0% +this every point on the wavefront is a +source of thical wave + + align:start position:0% +source of thical wave + + + align:start position:0% +source of thical wave +fronts + + align:start position:0% +fronts + + + align:start position:0% +fronts +normally when there's no pin hole here + + align:start position:0% +normally when there's no pin hole here + + + align:start position:0% +normally when there's no pin hole here +that doesn't matter because our next + + align:start position:0% +that doesn't matter because our next + + + align:start position:0% +that doesn't matter because our next +wavefront is then made out of the sum of + + align:start position:0% +wavefront is then made out of the sum of + + + align:start position:0% +wavefront is then made out of the sum of +all of these little fical wavefronts but + + align:start position:0% +all of these little fical wavefronts but + + + align:start position:0% +all of these little fical wavefronts but +when we put our pinhole aperture in the + + align:start position:0% +when we put our pinhole aperture in the + + + align:start position:0% +when we put our pinhole aperture in the +way we block out some of those wave + + align:start position:0% +way we block out some of those wave + + + align:start position:0% +way we block out some of those wave +fronts and instead we start to get + + align:start position:0% +fronts and instead we start to get + + + align:start position:0% +fronts and instead we start to get +defraction so we start to get spherical + + align:start position:0% +defraction so we start to get spherical + + + align:start position:0% +defraction so we start to get spherical +waves coming out from this and so if we + + align:start position:0% +waves coming out from this and so if we + + + align:start position:0% +waves coming out from this and so if we +initially had a point source it's now + + align:start position:0% +initially had a point source it's now + + + align:start position:0% +initially had a point source it's now +going to be imaged into a blurry Source + + align:start position:0% +going to be imaged into a blurry Source + + + align:start position:0% +going to be imaged into a blurry Source +here + + align:start position:0% +here + + + align:start position:0% +here +and so the + + align:start position:0% + + + + align:start position:0% + +UHS okay I can't remember I think it's + + align:start position:0% +UHS okay I can't remember I think it's + + + align:start position:0% +UHS okay I can't remember I think it's +the rally criteria the rally criteria + + align:start position:0% +the rally criteria the rally criteria + + + align:start position:0% +the rally criteria the rally criteria +says that if you have two dots like + + align:start position:0% +says that if you have two dots like + + + align:start position:0% +says that if you have two dots like +this for + + align:start position:0% +this for + + + align:start position:0% +this for +example that are some distance apart + + align:start position:0% +example that are some distance apart + + + align:start position:0% +example that are some distance apart +then we can only distinguish them um if + + align:start position:0% +then we can only distinguish them um if + + + align:start position:0% +then we can only distinguish them um if +they're + + align:start position:0% +they're + + + align:start position:0% +they're +blur is separated and this + + align:start position:0% +blur is separated and this + + + align:start position:0% +blur is separated and this +separation that sets a resolution is + + align:start position:0% +separation that sets a resolution is + + + align:start position:0% +separation that sets a resolution is +1.22 Lambda over + + align:start position:0% +1.22 Lambda over + + + align:start position:0% +1.22 Lambda over +D that's an angle space so I multiply it + + align:start position:0% +D that's an angle space so I multiply it + + + align:start position:0% +D that's an angle space so I multiply it +by V to bring that angle into a real uh + + align:start position:0% +by V to bring that angle into a real uh + + + align:start position:0% +by V to bring that angle into a real uh +position on our detector here so this + + align:start position:0% +position on our detector here so this + + + align:start position:0% +position on our detector here so this +1.22 comes from like zeros of the AR + + align:start position:0% +1.22 comes from like zeros of the AR + + + align:start position:0% +1.22 comes from like zeros of the AR +function these are actually like little + + align:start position:0% +function these are actually like little + + + align:start position:0% +function these are actually like little +syncs and we're trying to make sure that + + align:start position:0% +syncs and we're trying to make sure that + + + align:start position:0% +syncs and we're trying to make sure that +the first zeros are separated between + + align:start position:0% +the first zeros are separated between + + + align:start position:0% +the first zeros are separated between +these two here you may have seen this if + + align:start position:0% +these two here you may have seen this if + + + align:start position:0% +these two here you may have seen this if +you've done fraction Theory before so + + align:start position:0% +you've done fraction Theory before so + + + align:start position:0% +you've done fraction Theory before so +the geometric blur doesn't care about + + align:start position:0% +the geometric blur doesn't care about + + + align:start position:0% +the geometric blur doesn't care about +the wavelength of the light doesn't care + + align:start position:0% +the wavelength of the light doesn't care + + + align:start position:0% +the wavelength of the light doesn't care +about the energy of the photons the + + align:start position:0% +about the energy of the photons the + + + align:start position:0% +about the energy of the photons the +defraction blur does care about the + + align:start position:0% +defraction blur does care about the + + + align:start position:0% +defraction blur does care about the +wavelength of the light because it's a + + align:start position:0% +wavelength of the light because it's a + + + align:start position:0% +wavelength of the light because it's a +wave effect here and so we can make the + + align:start position:0% +wave effect here and so we can make the + + + align:start position:0% +wave effect here and so we can make the +refractive blur go away by having a + + align:start position:0% +refractive blur go away by having a + + + align:start position:0% +refractive blur go away by having a +bigger pinhole or by having a shorter + + align:start position:0% +bigger pinhole or by having a shorter + + + align:start position:0% +bigger pinhole or by having a shorter +wavelength so if we go to a bigger pin + + align:start position:0% +wavelength so if we go to a bigger pin + + + align:start position:0% +wavelength so if we go to a bigger pin +hole then our geometric blur will be + + align:start position:0% +hole then our geometric blur will be + + + align:start position:0% +hole then our geometric blur will be +worse and so there's actually a + + align:start position:0% +worse and so there's actually a + + + align:start position:0% +worse and so there's actually a +trade-off between these two there'll be + + align:start position:0% +trade-off between these two there'll be + + + align:start position:0% +trade-off between these two there'll be +a sweet spot that gives you the best + + align:start position:0% +a sweet spot that gives you the best + + + align:start position:0% +a sweet spot that gives you the best +resolution where you minimize the sum of + + align:start position:0% +resolution where you minimize the sum of + + + align:start position:0% +resolution where you minimize the sum of +the defraction and the geometric + + align:start position:0% +the defraction and the geometric + + + align:start position:0% +the defraction and the geometric +resolution but you need to think about + + align:start position:0% +resolution but you need to think about + + + align:start position:0% +resolution but you need to think about +this when you're designing pin + + align:start position:0% + + + + align:start position:0% + +okay oh the other thing about this is if + + align:start position:0% +okay oh the other thing about this is if + + + align:start position:0% +okay oh the other thing about this is if +you have a source that is emitting lots + + align:start position:0% +you have a source that is emitting lots + + + align:start position:0% +you have a source that is emitting lots +of light in lots of different + + align:start position:0% +of light in lots of different + + + align:start position:0% +of light in lots of different +wavelengths then the short wavelengths + + align:start position:0% +wavelengths then the short wavelengths + + + align:start position:0% +wavelengths then the short wavelengths +will be defract blurred and they'll be + + align:start position:0% +will be defract blurred and they'll be + + + align:start position:0% +will be defract blurred and they'll be +smeared out over your detector and the + + align:start position:0% +smeared out over your detector and the + + + align:start position:0% +smeared out over your detector and the +long wavelengths won't be but that means + + align:start position:0% +long wavelengths won't be but that means + + + align:start position:0% +long wavelengths won't be but that means +that you'll have this like blur over + + align:start position:0% +that you'll have this like blur over + + + align:start position:0% +that you'll have this like blur over +your whole detector from the short + + align:start position:0% +your whole detector from the short + + + align:start position:0% +your whole detector from the short +wavelengths uh which reduces your signal + + align:start position:0% +wavelengths uh which reduces your signal + + + align:start position:0% +wavelengths uh which reduces your signal +to noise and so this is especially where + + align:start position:0% +to noise and so this is especially where + + + align:start position:0% +to noise and so this is especially where +you want to have a + + align:start position:0% +you want to have a + + + align:start position:0% +you want to have a +filter so you want to filter out the low + + align:start position:0% +filter so you want to filter out the low + + + align:start position:0% +filter so you want to filter out the low +wavelengths so that they don't blur up + + align:start position:0% +wavelengths so that they don't blur up + + + align:start position:0% +wavelengths so that they don't blur up +uh out your image and you want to just + + align:start position:0% +uh out your image and you want to just + + + align:start position:0% +uh out your image and you want to just +have the high wavelengths like these + + align:start position:0% +have the high wavelengths like these + + + align:start position:0% +have the high wavelengths like these +ones here make an image just in like + + align:start position:0% +ones here make an image just in like + + + align:start position:0% +ones here make an image just in like +some of the K Alpha emission from the + + align:start position:0% +some of the K Alpha emission from the + + + align:start position:0% +some of the K Alpha emission from the +very hot parts of your + + align:start position:0% +very hot parts of your + + + align:start position:0% +very hot parts of your +plas okay + + align:start position:0% + + + + align:start position:0% + +questions + + align:start position:0% +questions + + + align:start position:0% +questions +yeah + + align:start position:0% + + + + align:start position:0% + +yes yes I'm not sure how that comes into + + align:start position:0% +yes yes I'm not sure how that comes into + + + align:start position:0% +yes yes I'm not sure how that comes into +this geometric optics framework + + align:start position:0% + + + + align:start position:0% + +though okay I yeah I see where that's + + align:start position:0% +though okay I yeah I see where that's + + + align:start position:0% +though okay I yeah I see where that's +going for me this is for a pinhole it's + + align:start position:0% +going for me this is for a pinhole it's + + + align:start position:0% +going for me this is for a pinhole it's +always going to be inverted I guess + + align:start position:0% +always going to be inverted I guess + + + align:start position:0% +always going to be inverted I guess +theoretically you put two pin holes no + + align:start position:0% +theoretically you put two pin holes no + + + align:start position:0% +theoretically you put two pin holes no +that doesn't work well always inverted + + align:start position:0% +that doesn't work well always inverted + + + align:start position:0% +that doesn't work well always inverted +so yeah so maybe maybe it's negative in + + align:start position:0% +so yeah so maybe maybe it's negative in + + + align:start position:0% +so yeah so maybe maybe it's negative in +someone's sign convention but nothing in + + align:start position:0% +someone's sign convention but nothing in + + + align:start position:0% +someone's sign convention but nothing in +the one I'm using here because it's + + align:start position:0% +the one I'm using here because it's + + + align:start position:0% +the one I'm using here because it's +always true yeah good + + align:start position:0% + + + + align:start position:0% + +question yeah well what I've missed out + + align:start position:0% +question yeah well what I've missed out + + + align:start position:0% +question yeah well what I've missed out +here is in fact that the transmission of + + align:start position:0% +here is in fact that the transmission of + + + align:start position:0% +here is in fact that the transmission of +as you know a thin bit of metal foil is + + align:start position:0% +as you know a thin bit of metal foil is + + + align:start position:0% +as you know a thin bit of metal foil is +actually opaque to visible light so if I + + align:start position:0% +actually opaque to visible light so if I + + + align:start position:0% +actually opaque to visible light so if I +put a very thin bit of aluminium foil in + + align:start position:0% +put a very thin bit of aluminium foil in + + + align:start position:0% +put a very thin bit of aluminium foil in +there I will definitely block out the + + align:start position:0% +there I will definitely block out the + + + align:start position:0% +there I will definitely block out the +light and you need like 200 nanometers + + align:start position:0% +light and you need like 200 nanometers + + + align:start position:0% +light and you need like 200 nanometers +so you can just deposit it on like some + + align:start position:0% +so you can just deposit it on like some + + + align:start position:0% +so you can just deposit it on like some +basically transparent plastic and then + + align:start position:0% +basically transparent plastic and then + + + align:start position:0% +basically transparent plastic and then +you'll also get the filtering from the + + align:start position:0% +you'll also get the filtering from the + + + align:start position:0% +you'll also get the filtering from the +aluminium k for example so yeah we + + align:start position:0% +aluminium k for example so yeah we + + + align:start position:0% +aluminium k for example so yeah we +haven't gone down to very low energies + + align:start position:0% +haven't gone down to very low energies + + + align:start position:0% +haven't gone down to very low energies +this is kind of like an x-ray regime + + align:start position:0% +this is kind of like an x-ray regime + + + align:start position:0% +this is kind of like an x-ray regime +treatment of it so of course you need + + align:start position:0% +treatment of it so of course you need + + + align:start position:0% +treatment of it so of course you need +x-ray photons in order to even get the + + align:start position:0% +x-ray photons in order to even get the + + + align:start position:0% +x-ray photons in order to even get the +the LH in reality this goes down and + + align:start position:0% +the LH in reality this goes down and + + + align:start position:0% +the LH in reality this goes down and +some other stuff happen down at this um + + align:start position:0% +some other stuff happen down at this um + + + align:start position:0% +some other stuff happen down at this um +visible wavelength yeah but anything any + + align:start position:0% +visible wavelength yeah but anything any + + + align:start position:0% +visible wavelength yeah but anything any +metal that is sufficiently thick and it + + align:start position:0% +metal that is sufficiently thick and it + + + align:start position:0% +metal that is sufficiently thick and it +doesn't need to be very thick will block + + align:start position:0% +doesn't need to be very thick will block + + + align:start position:0% +doesn't need to be very thick will block +all the visible light + + align:start position:0% + + + + align:start position:0% + +out + + align:start position:0% +out + + + align:start position:0% +out +yes you're right I just constantly get + + align:start position:0% +yes you're right I just constantly get + + + align:start position:0% +yes you're right I just constantly get +confused between wavelength and + + align:start position:0% + + + + align:start position:0% + +frequency filter out long way + + align:start position:0% + + + + align:start position:0% + +which is visible light + + align:start position:0% + + + + align:start position:0% + +generally okay good + + align:start position:0% + + + + align:start position:0% + +question you can also do imaging and I'm + + align:start position:0% +question you can also do imaging and I'm + + + align:start position:0% +question you can also do imaging and I'm +not going to talk about length pinhole + + align:start position:0% +not going to talk about length pinhole + + + align:start position:0% +not going to talk about length pinhole +Imaging is quite limited um you can also + + align:start position:0% +Imaging is quite limited um you can also + + + align:start position:0% +Imaging is quite limited um you can also +do imaging + + align:start position:0% + + + + align:start position:0% + +with vent + + align:start position:0% +with vent + + + align:start position:0% +with vent +crystals so if you've ever looked at + + align:start position:0% +crystals so if you've ever looked at + + + align:start position:0% +crystals so if you've ever looked at +uh defraction of x-rays from crystals + + align:start position:0% +uh defraction of x-rays from crystals + + + align:start position:0% +uh defraction of x-rays from crystals +you'll know that the uh crystals will + + align:start position:0% +you'll know that the uh crystals will + + + align:start position:0% +you'll know that the uh crystals will +defract light of certain wavelengths and + + align:start position:0% +defract light of certain wavelengths and + + + align:start position:0% +defract light of certain wavelengths and +if you have a bent Crystal you can also + + align:start position:0% +if you have a bent Crystal you can also + + + align:start position:0% +if you have a bent Crystal you can also +be focusing with it so people spend a + + align:start position:0% +be focusing with it so people spend a + + + align:start position:0% +be focusing with it so people spend a +lot of time very gently bending bits of + + align:start position:0% +lot of time very gently bending bits of + + + align:start position:0% +lot of time very gently bending bits of +Crystal and that makes a reflective lens + + align:start position:0% +Crystal and that makes a reflective lens + + + align:start position:0% +Crystal and that makes a reflective lens +so you can't have a transmissive lens + + align:start position:0% +so you can't have a transmissive lens + + + align:start position:0% +so you can't have a transmissive lens +but you can have a bent mirror + + align:start position:0% +but you can have a bent mirror + + + align:start position:0% +but you can have a bent mirror +effectively so there are you know two + + align:start position:0% +effectively so there are you know two + + + align:start position:0% +effectively so there are you know two +ways to focus light you can have a lens + + align:start position:0% +ways to focus light you can have a lens + + + align:start position:0% +ways to focus light you can have a lens +like this that your light goes through + + align:start position:0% +like this that your light goes through + + + align:start position:0% +like this that your light goes through +or equivalently you you can have a + + align:start position:0% +or equivalently you you can have a + + + align:start position:0% +or equivalently you you can have a +mirror like this that the light reflects + + align:start position:0% +mirror like this that the light reflects + + + align:start position:0% +mirror like this that the light reflects +off and because the mirror is + + align:start position:0% +off and because the mirror is + + + align:start position:0% +off and because the mirror is +bent it will get Focus to a different + + align:start position:0% +bent it will get Focus to a different + + + align:start position:0% +bent it will get Focus to a different +point and as you adjust this mirror it + + align:start position:0% +point and as you adjust this mirror it + + + align:start position:0% +point and as you adjust this mirror it +will depend where this gets focused on + + align:start position:0% +will depend where this gets focused on + + + align:start position:0% +will depend where this gets focused on +now even a crystal is not a mirror for + + align:start position:0% +now even a crystal is not a mirror for + + + align:start position:0% +now even a crystal is not a mirror for +x-rays it's a mirror for a certain + + align:start position:0% +x-rays it's a mirror for a certain + + + align:start position:0% +x-rays it's a mirror for a certain +wavelength of light and so if you put + + align:start position:0% +wavelength of light and so if you put + + + align:start position:0% +wavelength of light and so if you put +your detector here you might have the K + + align:start position:0% +your detector here you might have the K + + + align:start position:0% +your detector here you might have the K +Alpha focused onto your detector but for + + align:start position:0% +Alpha focused onto your detector but for + + + align:start position:0% +Alpha focused onto your detector but for +example the K beta which is coming in + + align:start position:0% +example the K beta which is coming in + + + align:start position:0% +example the K beta which is coming in +the same direction might get + + align:start position:0% +the same direction might get + + + align:start position:0% +the same direction might get +reflected or + + align:start position:0% +reflected or + + + align:start position:0% +reflected or +defract off to a different point which + + align:start position:0% +defract off to a different point which + + + align:start position:0% +defract off to a different point which +is off your detector so this is a way of + + align:start position:0% +is off your detector so this is a way of + + + align:start position:0% +is off your detector so this is a way of +doing monochromatic imag so effectively + + align:start position:0% +doing monochromatic imag so effectively + + + align:start position:0% +doing monochromatic imag so effectively +your Crystal here acts as both the + + align:start position:0% +your Crystal here acts as both the + + + align:start position:0% +your Crystal here acts as both the +filter and the focusing element so you + + align:start position:0% +filter and the focusing element so you + + + align:start position:0% +filter and the focusing element so you +can make beautiful images um you don't + + align:start position:0% +can make beautiful images um you don't + + + align:start position:0% +can make beautiful images um you don't +need to have a tiny pin hole so you can + + align:start position:0% +need to have a tiny pin hole so you can + + + align:start position:0% +need to have a tiny pin hole so you can +get lots and lots of light uh and you + + align:start position:0% +get lots and lots of light uh and you + + + align:start position:0% +get lots and lots of light uh and you +can get images with just a single + + align:start position:0% +can get images with just a single + + + align:start position:0% +can get images with just a single +wavelength which can be very powerful + + align:start position:0% +wavelength which can be very powerful + + + align:start position:0% +wavelength which can be very powerful +for saying like this is the very hot bit + + align:start position:0% +for saying like this is the very hot bit + + + align:start position:0% +for saying like this is the very hot bit +of my plasma that's producing K Alpha so + + align:start position:0% +of my plasma that's producing K Alpha so + + + align:start position:0% +of my plasma that's producing K Alpha so +B Crystal you can get what's called + + align:start position:0% +B Crystal you can get what's called + + + align:start position:0% +B Crystal you can get what's called +monochromatic Imaging + + align:start position:0% + + + + align:start position:0% + +but bending bristles is extraordinarily + + align:start position:0% +but bending bristles is extraordinarily + + + align:start position:0% +but bending bristles is extraordinarily +expensive so pin holes are very very + + align:start position:0% +expensive so pin holes are very very + + + align:start position:0% +expensive so pin holes are very very +cheap and you'll find a lot of people + + align:start position:0% +cheap and you'll find a lot of people + + + align:start position:0% +cheap and you'll find a lot of people +using pinoles because they work pretty + + align:start position:0% +using pinoles because they work pretty + + + align:start position:0% +using pinoles because they work pretty +well and of course the bent crystals + + align:start position:0% +well and of course the bent crystals + + + align:start position:0% +well and of course the bent crystals +only work for individual energies and so + + align:start position:0% +only work for individual energies and so + + + align:start position:0% +only work for individual energies and so +if you want to like try and measure sort + + align:start position:0% +if you want to like try and measure sort + + + align:start position:0% +if you want to like try and measure sort +of more broadly what the radiation is + + align:start position:0% +of more broadly what the radiation is + + + align:start position:0% +of more broadly what the radiation is +from the plasma you'll miss out on that + + align:start position:0% +from the plasma you'll miss out on that + + + align:start position:0% +from the plasma you'll miss out on that +okay + + align:start position:0% + + + + align:start position:0% + +[Laughter] + + align:start position:0% + + + + align:start position:0% + +yeah my last last set of notes for today + + align:start position:0% +yeah my last last set of notes for today + + + align:start position:0% +yeah my last last set of notes for today +I + + align:start position:0% + + + + align:start position:0% + +promise sorry what + + align:start position:0% +promise sorry what + + + align:start position:0% +promise sorry what +yeah yeah diodes are pretty + + align:start position:0% + + + + align:start position:0% + +good no no nice silicon 50 nmet stick + + align:start position:0% +good no no nice silicon 50 nmet stick + + + align:start position:0% +good no no nice silicon 50 nmet stick +perfectly good for x-rays up to about 10 + + align:start position:0% +perfectly good for x-rays up to about 10 + + + align:start position:0% +perfectly good for x-rays up to about 10 +KV so um nothing wrong with + + align:start position:0% + + + + align:start position:0% + +di okay so a lot of these + + align:start position:0% +di okay so a lot of these + + + align:start position:0% +di okay so a lot of these +detectors are simply + + align:start position:0% +detectors are simply + + + align:start position:0% +detectors are simply +filled if you went to the dentist decade + + align:start position:0% +filled if you went to the dentist decade + + + align:start position:0% +filled if you went to the dentist decade +or so ago they would have used film in + + align:start position:0% +or so ago they would have used film in + + + align:start position:0% +or so ago they would have used film in +their x-ray things and in fact most of + + align:start position:0% +their x-ray things and in fact most of + + + align:start position:0% +their x-ray things and in fact most of +X-ray film was developed for medical + + align:start position:0% + + + + align:start position:0% + +applications and film is really good + + align:start position:0% +applications and film is really good + + + align:start position:0% +applications and film is really good +okay so film has a huge drawback it's + + align:start position:0% +okay so film has a huge drawback it's + + + align:start position:0% +okay so film has a huge drawback it's +time integrated so you have no sense of + + align:start position:0% +time integrated so you have no sense of + + + align:start position:0% +time integrated so you have no sense of +uh what the time is you have an integral + + align:start position:0% +uh what the time is you have an integral + + + align:start position:0% +uh what the time is you have an integral +of the + + align:start position:0% + + + + align:start position:0% + +intensity over time so if you have some + + align:start position:0% +intensity over time so if you have some + + + align:start position:0% +intensity over time so if you have some +filtering maybe you have still frequency + + align:start position:0% +filtering maybe you have still frequency + + + align:start position:0% +filtering maybe you have still frequency +information left in your image because + + align:start position:0% +information left in your image because + + + align:start position:0% +information left in your image because +you're like oh this is coming all from + + align:start position:0% +you're like oh this is coming all from + + + align:start position:0% +you're like oh this is coming all from +the K Alpha I got a special filter in + + align:start position:0% +the K Alpha I got a special filter in + + + align:start position:0% +the K Alpha I got a special filter in +but you don't have any time so that + + align:start position:0% +but you don't have any time so that + + + align:start position:0% +but you don't have any time so that +could be a really big problem if you're + + align:start position:0% +could be a really big problem if you're + + + align:start position:0% +could be a really big problem if you're +doing something with like a rapid + + align:start position:0% +doing something with like a rapid + + + align:start position:0% +doing something with like a rapid +implosion like in initial confin Fusion + + align:start position:0% +implosion like in initial confin Fusion + + + align:start position:0% +implosion like in initial confin Fusion +but it doesn't have to be a big problem + + align:start position:0% +but it doesn't have to be a big problem + + + align:start position:0% +but it doesn't have to be a big problem +for example if you've + + align:start position:0% +for example if you've + + + align:start position:0% +for example if you've +got uh a signal that is very bursty in + + align:start position:0% +got uh a signal that is very bursty in + + + align:start position:0% +got uh a signal that is very bursty in +time like an ICF so this could be you + + align:start position:0% +time like an ICF so this could be you + + + align:start position:0% +time like an ICF so this could be you +know a few hundred T seconds + + align:start position:0% +know a few hundred T seconds + + + align:start position:0% +know a few hundred T seconds +across and you have an x-ray diode + + align:start position:0% +across and you have an x-ray diode + + + align:start position:0% +across and you have an x-ray diode +looking at it and that iode has time + + align:start position:0% +looking at it and that iode has time + + + align:start position:0% +looking at it and that iode has time +resolution but no spatial resolution + + align:start position:0% +resolution but no spatial resolution + + + align:start position:0% +resolution but no spatial resolution +then you could use that di signal to say + + align:start position:0% +then you could use that di signal to say + + + align:start position:0% +then you could use that di signal to say +well all of my really bright x-rays REM + + align:start position:0% +well all of my really bright x-rays REM + + + align:start position:0% +well all of my really bright x-rays REM +missed 100 PCS so although this is time + + align:start position:0% +missed 100 PCS so although this is time + + + align:start position:0% +missed 100 PCS so although this is time +integrated I actually know that the time + + align:start position:0% +integrated I actually know that the time + + + align:start position:0% +integrated I actually know that the time +that this was integrating over was only + + align:start position:0% +that this was integrating over was only + + + align:start position:0% +that this was integrating over was only +T to t plus 100 PC so you can use a + + align:start position:0% +T to t plus 100 PC so you can use a + + + align:start position:0% +T to t plus 100 PC so you can use a +combination of Diagnostics to localize + + align:start position:0% +combination of Diagnostics to localize + + + align:start position:0% +combination of Diagnostics to localize +your signal in time that might be okay + + align:start position:0% +your signal in time that might be okay + + + align:start position:0% +your signal in time that might be okay +film is really high resolution um you + + align:start position:0% +film is really high resolution um you + + + align:start position:0% +film is really high resolution um you +know film grains are very small so it's + + align:start position:0% +know film grains are very small so it's + + + align:start position:0% +know film grains are very small so it's +can be much higher resolution than a + + align:start position:0% +can be much higher resolution than a + + + align:start position:0% +can be much higher resolution than a +detector um like something that has + + align:start position:0% +detector um like something that has + + + align:start position:0% +detector um like something that has +pixels uh you obviously don't have to + + align:start position:0% +pixels uh you obviously don't have to + + + align:start position:0% +pixels uh you obviously don't have to +scan it at very high resolution but we + + align:start position:0% +scan it at very high resolution but we + + + align:start position:0% +scan it at very high resolution but we +can do that it's also very well + + align:start position:0% +can do that it's also very well + + + align:start position:0% +can do that it's also very well +characterized so um although it may not + + align:start position:0% +characterized so um although it may not + + + align:start position:0% +characterized so um although it may not +be linear we know like this amount of + + align:start position:0% +be linear we know like this amount of + + + align:start position:0% +be linear we know like this amount of +Darkness corresponds to this much energy + + align:start position:0% +Darkness corresponds to this much energy + + + align:start position:0% +Darkness corresponds to this much energy +deposited so film is actually really + + align:start position:0% +deposited so film is actually really + + + align:start position:0% +deposited so film is actually really +precious and unfortunately a lot of of + + align:start position:0% +precious and unfortunately a lot of of + + + align:start position:0% +precious and unfortunately a lot of of +film manufacturers like Kodak have + + align:start position:0% +film manufacturers like Kodak have + + + align:start position:0% +film manufacturers like Kodak have +stopped making x-ray film because there + + align:start position:0% +stopped making x-ray film because there + + + align:start position:0% +stopped making x-ray film because there +isn't a market anymore I believe Omega + + align:start position:0% +isn't a market anymore I believe Omega + + + align:start position:0% +isn't a market anymore I believe Omega +has one of the large the Omega facility + + align:start position:0% +has one of the large the Omega facility + + + align:start position:0% +has one of the large the Omega facility +at rockchester has one of the largest + + align:start position:0% +at rockchester has one of the largest + + + align:start position:0% +at rockchester has one of the largest +stock piles of remaining medical film in + + align:start position:0% +stock piles of remaining medical film in + + + align:start position:0% +stock piles of remaining medical film in +a fridge because they can't buy it + + align:start position:0% +a fridge because they can't buy it + + + align:start position:0% +a fridge because they can't buy it +anymore and no one else is has any left + + align:start position:0% +anymore and no one else is has any left + + + align:start position:0% +anymore and no one else is has any left +so people keep begging Omega for some of + + align:start position:0% +so people keep begging Omega for some of + + + align:start position:0% +so people keep begging Omega for some of +their film from time to time so it's + + align:start position:0% +their film from time to time so it's + + + align:start position:0% +their film from time to time so it's +good stuff but a lot of people have now + + align:start position:0% +good stuff but a lot of people have now + + + align:start position:0% +good stuff but a lot of people have now +moved to something called image + + align:start position:0% + + + + align:start position:0% + +plate image plate at first glance looks + + align:start position:0% +plate image plate at first glance looks + + + align:start position:0% +plate image plate at first glance looks +an awful lot light film it's a bit of + + align:start position:0% +an awful lot light film it's a bit of + + + align:start position:0% +an awful lot light film it's a bit of +plastic uh plastic looking stuff uh it's + + align:start position:0% +plastic uh plastic looking stuff uh it's + + + align:start position:0% +plastic uh plastic looking stuff uh it's +time integrating again there's no + + align:start position:0% +time integrating again there's no + + + align:start position:0% +time integrating again there's no +electronics to it what happens with + + align:start position:0% +electronics to it what happens with + + + align:start position:0% +electronics to it what happens with +image plate which is neat is the x-rays + + align:start position:0% +image plate which is neat is the x-rays + + + align:start position:0% +image plate which is neat is the x-rays +excited up to a meta stable state so you + + align:start position:0% +excited up to a meta stable state so you + + + align:start position:0% +excited up to a meta stable state so you +have + + align:start position:0% +have + + + align:start position:0% +have +the + + align:start position:0% +the + + + align:start position:0% +the +x-rays excite it up to this metastable + + align:start position:0% +x-rays excite it up to this metastable + + + align:start position:0% +x-rays excite it up to this metastable +state up here and because it's + + align:start position:0% +state up here and because it's + + + align:start position:0% +state up here and because it's +metastable it doesn't actually Decay + + align:start position:0% +metastable it doesn't actually Decay + + + align:start position:0% +metastable it doesn't actually Decay +straight away it's it's this is a you + + align:start position:0% +straight away it's it's this is a you + + + align:start position:0% +straight away it's it's this is a you +know this may be ah sorry yeah it + + align:start position:0% +know this may be ah sorry yeah it + + + align:start position:0% +know this may be ah sorry yeah it +doesn't make sense unless I do it like + + align:start position:0% +doesn't make sense unless I do it like + + + align:start position:0% +doesn't make sense unless I do it like +this the + + align:start position:0% +this the + + + align:start position:0% +this the +x-rays excite the the atoms in the + + align:start position:0% +x-rays excite the the atoms in the + + + align:start position:0% +x-rays excite the the atoms in the +plastic up to some Upper State and then + + align:start position:0% +plastic up to some Upper State and then + + + align:start position:0% +plastic up to some Upper State and then +via some non-radiated decays because of + + align:start position:0% +via some non-radiated decays because of + + + align:start position:0% +via some non-radiated decays because of +the peculiarity the plastic the system + + align:start position:0% +the peculiarity the plastic the system + + + align:start position:0% +the peculiarity the plastic the system +decays down to a metastable state and + + align:start position:0% +decays down to a metastable state and + + + align:start position:0% +decays down to a metastable state and +metastable in this case means that there + + align:start position:0% +metastable in this case means that there + + + align:start position:0% +metastable in this case means that there +is no permitted transition down this + + align:start position:0% +is no permitted transition down this + + + align:start position:0% +is no permitted transition down this +Lower State + + align:start position:0% + + + + align:start position:0% + +here this doesn't happen um so this is a + + align:start position:0% +here this doesn't happen um so this is a + + + align:start position:0% +here this doesn't happen um so this is a +forbidden + + align:start position:0% + + + + align:start position:0% + +transition now even though the + + align:start position:0% +transition now even though the + + + align:start position:0% +transition now even though the +transition is forbidden there will be + + align:start position:0% +transition is forbidden there will be + + + align:start position:0% +transition is forbidden there will be +some other mechanism mostly to do as + + align:start position:0% +some other mechanism mostly to do as + + + align:start position:0% +some other mechanism mostly to do as +collisions which will eventually de + + align:start position:0% +collisions which will eventually de + + + align:start position:0% +collisions which will eventually de +excite the atoms in your detection + + align:start position:0% +excite the atoms in your detection + + + align:start position:0% +excite the atoms in your detection +again so You' got like a few hours to + + align:start position:0% +again so You' got like a few hours to + + + align:start position:0% +again so You' got like a few hours to +get this bit of image plate out and put + + align:start position:0% +get this bit of image plate out and put + + + align:start position:0% +get this bit of image plate out and put +it into a scanner and what the scanner + + align:start position:0% +it into a scanner and what the scanner + + + align:start position:0% +it into a scanner and what the scanner +does very cleverly is that it uses a + + align:start position:0% +does very cleverly is that it uses a + + + align:start position:0% +does very cleverly is that it uses a +laser to excite the image plate back up + + align:start position:0% +laser to excite the image plate back up + + + align:start position:0% +laser to excite the image plate back up +to some upper level and then it looks + + align:start position:0% +to some upper level and then it looks + + + align:start position:0% +to some upper level and then it looks +for the fluoresence as it decays back + + align:start position:0% +for the fluoresence as it decays back + + + align:start position:0% +for the fluoresence as it decays back +down again so you can read off the + + align:start position:0% +down again so you can read off the + + + align:start position:0% +down again so you can read off the +number of stored photons in each little + + align:start position:0% +number of stored photons in each little + + + align:start position:0% +number of stored photons in each little +bit of plastic using this little laser + + align:start position:0% +bit of plastic using this little laser + + + align:start position:0% +bit of plastic using this little laser +and do this scan and then you can reuse + + align:start position:0% +and do this scan and then you can reuse + + + align:start position:0% +and do this scan and then you can reuse +the image plate which you can't do as + + align:start position:0% +the image plate which you can't do as + + + align:start position:0% +the image plate which you can't do as +fill so image plate is like pretty nice + + align:start position:0% +fill so image plate is like pretty nice + + + align:start position:0% +fill so image plate is like pretty nice +um but you need an expensive scanner + + align:start position:0% +um but you need an expensive scanner + + + align:start position:0% +um but you need an expensive scanner +it has like a laser + + align:start position:0% + + + + align:start position:0% + +readout so both of these are time + + align:start position:0% +readout so both of these are time + + + align:start position:0% +readout so both of these are time +integrated um you can get time gated + + align:start position:0% + + + + align:start position:0% + +cameras so these are cameras for example + + align:start position:0% +cameras so these are cameras for example + + + align:start position:0% +cameras so these are cameras for example +which + + align:start position:0% +which + + + align:start position:0% +which +have some gate on them like this and + + align:start position:0% +have some gate on them like this and + + + align:start position:0% +have some gate on them like this and +maybe that gate is five NCS or something + + align:start position:0% +maybe that gate is five NCS or something + + + align:start position:0% +maybe that gate is five NCS or something +like that where you're really gating a + + align:start position:0% +like that where you're really gating a + + + align:start position:0% +like that where you're really gating a +very very fast burst of X-ray so that + + align:start position:0% +very very fast burst of X-ray so that + + + align:start position:0% +very very fast burst of X-ray so that +avoid this problem you know exactly when + + align:start position:0% +avoid this problem you know exactly when + + + align:start position:0% +avoid this problem you know exactly when +the x-rays were coming out but of course + + align:start position:0% +the x-rays were coming out but of course + + + align:start position:0% +the x-rays were coming out but of course +A Time gated camera is very expensive + + align:start position:0% +A Time gated camera is very expensive + + + align:start position:0% +A Time gated camera is very expensive +because now it's got lots of + + align:start position:0% + + + + align:start position:0% + +electronics these are often things with + + align:start position:0% +electronics these are often things with + + + align:start position:0% +electronics these are often things with +names like hybrid + + align:start position:0% + + + + align:start position:0% + +cosos these cameras can be very very + + align:start position:0% +cosos these cameras can be very very + + + align:start position:0% +cosos these cameras can be very very +expensive and they also may have + + align:start position:0% +expensive and they also may have + + + align:start position:0% +expensive and they also may have +relatively low + + align:start position:0% + + + + align:start position:0% + +resolution because each pi costs a lot + + align:start position:0% +resolution because each pi costs a lot + + + align:start position:0% +resolution because each pi costs a lot +of + + align:start position:0% +of + + + align:start position:0% +of +money so if you can get away with using + + align:start position:0% +money so if you can get away with using + + + align:start position:0% +money so if you can get away with using +film image plate you might be tempted to + + align:start position:0% +film image plate you might be tempted to + + + align:start position:0% +film image plate you might be tempted to +do + + align:start position:0% +do + + + align:start position:0% +do +that finally there's something called a + + align:start position:0% +that finally there's something called a + + + align:start position:0% +that finally there's something called a +street + + align:start position:0% + + + + align:start position:0% + +camera Street camera is a slightly odd + + align:start position:0% +camera Street camera is a slightly odd + + + align:start position:0% +camera Street camera is a slightly odd +device and when you first see a street + + align:start position:0% +device and when you first see a street + + + align:start position:0% +device and when you first see a street +camera image very hard to understand + + align:start position:0% +camera image very hard to understand + + + align:start position:0% +camera image very hard to understand +what's going on what you get out of your + + align:start position:0% +what's going on what you get out of your + + + align:start position:0% +what's going on what you get out of your +street camera is actually something + + align:start position:0% +street camera is actually something + + + align:start position:0% +street camera is actually something +that has got non + + align:start position:0% + + + + align:start position:0% + +intensity position on one axis and time + + align:start position:0% +intensity position on one axis and time + + + align:start position:0% +intensity position on one axis and time +on the other axis so if you have + + align:start position:0% +on the other axis so if you have + + + align:start position:0% +on the other axis so if you have +something like an ICF capsule that is + + align:start position:0% +something like an ICF capsule that is + + + align:start position:0% +something like an ICF capsule that is +roughly circular and you put your streak + + align:start position:0% +roughly circular and you put your streak + + + align:start position:0% +roughly circular and you put your streak +slit here initially if this little + + align:start position:0% +slit here initially if this little + + + align:start position:0% +slit here initially if this little +circular blob is emitting nice and + + align:start position:0% +circular blob is emitting nice and + + + align:start position:0% +circular blob is emitting nice and +uniformly you would + + align:start position:0% +uniformly you would + + + align:start position:0% +uniformly you would +see nice uniform emission in all of X + + align:start position:0% +see nice uniform emission in all of X + + + align:start position:0% +see nice uniform emission in all of X +and as this ICF capsule gets + + align:start position:0% +and as this ICF capsule gets + + + align:start position:0% +and as this ICF capsule gets +smaller your slit stays the same and so + + align:start position:0% +smaller your slit stays the same and so + + + align:start position:0% +smaller your slit stays the same and so +the region that's being lit up on the + + align:start position:0% +the region that's being lit up on the + + + align:start position:0% +the region that's being lit up on the +slit gets smaller as well so you'd see a + + align:start position:0% +slit gets smaller as well so you'd see a + + + align:start position:0% +slit gets smaller as well so you'd see a +street image that looks like + + align:start position:0% +street image that looks like + + + align:start position:0% +street image that looks like +this where this is got more light on it + + align:start position:0% +this where this is got more light on it + + + align:start position:0% +this where this is got more light on it +and this region has no light so this is + + align:start position:0% +and this region has no light so this is + + + align:start position:0% +and this region has no light so this is +a very clever technique for monitoring + + align:start position:0% +a very clever technique for monitoring + + + align:start position:0% +a very clever technique for monitoring +like the evolution of a 1D profile of + + align:start position:0% +like the evolution of a 1D profile of + + + align:start position:0% +like the evolution of a 1D profile of +intensity in time and the reason these + + align:start position:0% +intensity in time and the reason these + + + align:start position:0% +intensity in time and the reason these +street cameras are so popular is that + + align:start position:0% +street cameras are so popular is that + + + align:start position:0% +street cameras are so popular is that +they're extremely fast and they're + + align:start position:0% +they're extremely fast and they're + + + align:start position:0% +they're extremely fast and they're +actually based on the same technology + + align:start position:0% +actually based on the same technology + + + align:start position:0% +actually based on the same technology +that a CRT television uh uses with like + + align:start position:0% +that a CRT television uh uses with like + + + align:start position:0% +that a CRT television uh uses with like +a beam of electrons being swept across + + align:start position:0% +a beam of electrons being swept across + + + align:start position:0% +a beam of electrons being swept across +here + + align:start position:0% +here + + + align:start position:0% +here +so they are very old though so everyone + + align:start position:0% +so they are very old though so everyone + + + align:start position:0% +so they are very old though so everyone +who has one they keep breaking all the + + align:start position:0% + + + + align:start position:0% + +time okay any questions on + + align:start position:0% +time okay any questions on + + + align:start position:0% +time okay any questions on +detectors that's all I have for you + + align:start position:0% +detectors that's all I have for you + + + align:start position:0% +detectors that's all I have for you +today + + align:start position:0% + + + + align:start position:0% + +yes normally what you actually have is a + + align:start position:0% +yes normally what you actually have is a + + + align:start position:0% +yes normally what you actually have is a +bit of film that sits behind the street + + align:start position:0% +bit of film that sits behind the street + + + align:start position:0% +bit of film that sits behind the street +camera window and so the film gets + + align:start position:0% +camera window and so the film gets + + + align:start position:0% +camera window and so the film gets +exposed and it has this pattern on it + + align:start position:0% +exposed and it has this pattern on it + + + align:start position:0% +exposed and it has this pattern on it +and you'll have some timing dots from a + + align:start position:0% + + + + align:start position:0% + +laser that will tell you how to + + align:start position:0% +laser that will tell you how to + + + align:start position:0% +laser that will tell you how to +calibrate your time AIS and you might + + align:start position:0% +calibrate your time AIS and you might + + + align:start position:0% +calibrate your time AIS and you might +have some fiducial that tells you how to + + align:start position:0% +have some fiducial that tells you how to + + + align:start position:0% +have some fiducial that tells you how to +calibrate the spatial axis here but + + align:start position:0% +calibrate the spatial axis here but + + + align:start position:0% +calibrate the spatial axis here but +because it's something like film it does + + align:start position:0% +because it's something like film it does + + + align:start position:0% +because it's something like film it does +have a dependence on the intensity so + + align:start position:0% +have a dependence on the intensity so + + + align:start position:0% +have a dependence on the intensity so +it's not binary um but the intensity may + + align:start position:0% +it's not binary um but the intensity may + + + align:start position:0% +it's not binary um but the intensity may +be very nonlinear because to get this + + align:start position:0% +be very nonlinear because to get this + + + align:start position:0% +be very nonlinear because to get this +image you're like generating an electron + + align:start position:0% +image you're like generating an electron + + + align:start position:0% +image you're like generating an electron +beam and sweeping it and there's like + + align:start position:0% +beam and sweeping it and there's like + + + align:start position:0% +beam and sweeping it and there's like +magnets and electron bunching and all + + align:start position:0% +magnets and electron bunching and all + + + align:start position:0% +magnets and electron bunching and all +sorts of things like that so + + align:start position:0% +sorts of things like that so + + + align:start position:0% +sorts of things like that so +interpreting these in a very + + align:start position:0% +interpreting these in a very + + + align:start position:0% +interpreting these in a very +quantitative way can be very very + + align:start position:0% +quantitative way can be very very + + + align:start position:0% +quantitative way can be very very +hard + + align:start position:0% + + + + align:start position:0% + +yeah yeah so there's something called a + + align:start position:0% +yeah yeah so there's something called a + + + align:start position:0% +yeah yeah so there's something called a +often something called like a + + align:start position:0% +often something called like a + + + align:start position:0% +often something called like a +microchannel plate which has some + + align:start position:0% +microchannel plate which has some + + + align:start position:0% +microchannel plate which has some +voltage across it when the uh photons + + align:start position:0% +voltage across it when the uh photons + + + align:start position:0% +voltage across it when the uh photons +come in they um ionize what's it + + align:start position:0% +come in they um ionize what's it + + + align:start position:0% +come in they um ionize what's it +photoelectric effect releasing electron + + align:start position:0% +photoelectric effect releasing electron + + + align:start position:0% +photoelectric effect releasing electron +from the surface that voltage sweeps the + + align:start position:0% +from the surface that voltage sweeps the + + + align:start position:0% +from the surface that voltage sweeps the +electron and accelerates it up there'll + + align:start position:0% +electron and accelerates it up there'll + + + align:start position:0% +electron and accelerates it up there'll +be magnets which bend the electron to a + + align:start position:0% +be magnets which bend the electron to a + + + align:start position:0% +be magnets which bend the electron to a +certain part of the time axis the + + align:start position:0% +certain part of the time axis the + + + align:start position:0% +certain part of the time axis the +electron will collide with a phosphor + + align:start position:0% +electron will collide with a phosphor + + + align:start position:0% +electron will collide with a phosphor +screen uh the electron excites the fosil + + align:start position:0% +screen uh the electron excites the fosil + + + align:start position:0% +screen uh the electron excites the fosil +the fosil decays and emits green light + + align:start position:0% +the fosil decays and emits green light + + + align:start position:0% +the fosil decays and emits green light +the green light is recorded + + align:start position:0% +the green light is recorded + + + align:start position:0% +the green light is recorded +by yeah so they're they're very fun uh + + align:start position:0% +by yeah so they're they're very fun uh + + + align:start position:0% +by yeah so they're they're very fun uh +but they are very complicated which is + + align:start position:0% +but they are very complicated which is + + + align:start position:0% +but they are very complicated which is +why you shouldn't like if you see a + + align:start position:0% +why you shouldn't like if you see a + + + align:start position:0% +why you shouldn't like if you see a +region that is twice as bright here than + + align:start position:0% +region that is twice as bright here than + + + align:start position:0% +region that is twice as bright here than +it is here that doesn't necessarily mean + + align:start position:0% +it is here that doesn't necessarily mean + + + align:start position:0% +it is here that doesn't necessarily mean +that it's emitting twice as many x-rays + + align:start position:0% +that it's emitting twice as many x-rays + + + align:start position:0% +that it's emitting twice as many x-rays +because it's very on Long linear and + + align:start position:0% +because it's very on Long linear and + + + align:start position:0% +because it's very on Long linear and +they're very sensitive to + + align:start position:0% + + + + align:start position:0% + +voltage yes it's a pulse magnetic field + + align:start position:0% +voltage yes it's a pulse magnetic field + + + align:start position:0% +voltage yes it's a pulse magnetic field +that's ramping up in time so as the + + align:start position:0% +that's ramping up in time so as the + + + align:start position:0% +that's ramping up in time so as the +magnetic field ramps up it sweeps + + align:start position:0% +magnetic field ramps up it sweeps + + + align:start position:0% +magnetic field ramps up it sweeps +electrons to different places that's + + align:start position:0% +electrons to different places that's + + + align:start position:0% +electrons to different places that's +exactly how cathode ray TV works and we + + align:start position:0% +exactly how cathode ray TV works and we + + + align:start position:0% +exactly how cathode ray TV works and we +were able to do cathode ray TVs to make + + align:start position:0% +were able to do cathode ray TVs to make + + + align:start position:0% +were able to do cathode ray TVs to make +moving images at 30 frames per second so + + align:start position:0% + + + + align:start position:0% + +yeah yeah but all the electrons from the + + align:start position:0% +yeah yeah but all the electrons from the + + + align:start position:0% +yeah yeah but all the electrons from the +photoelectric effect can be coming out + + align:start position:0% +photoelectric effect can be coming out + + + align:start position:0% +photoelectric effect can be coming out +with very similar energies and then + + align:start position:0% +with very similar energies and then + + + align:start position:0% +with very similar energies and then +they're accelerate so maybe they've got + + align:start position:0% +they're accelerate so maybe they've got + + + align:start position:0% +they're accelerate so maybe they've got +an energy range of a few EV but they're + + align:start position:0% +an energy range of a few EV but they're + + + align:start position:0% +an energy range of a few EV but they're +being accelerated over a killer electron + + align:start position:0% +being accelerated over a killer electron + + + align:start position:0% +being accelerated over a killer electron +volt which is also why you should not + + align:start position:0% +volt which is also why you should not + + + align:start position:0% +volt which is also why you should not +mess around with a crtv because inside + + align:start position:0% +mess around with a crtv because inside + + + align:start position:0% +mess around with a crtv because inside +it there is an electron beam that does + + align:start position:0% +it there is an electron beam that does + + + align:start position:0% +it there is an electron beam that does +Killer electron Vols + + align:start position:0% +Killer electron Vols + + + align:start position:0% +Killer electron Vols +yeah any other + + align:start position:0% +yeah any other + + + align:start position:0% +yeah any other +questions anyone online + + align:start position:0% + + + + align:start position:0% + +okay next lecture we are going to talk + + align:start position:0% +okay next lecture we are going to talk + + + align:start position:0% +okay next lecture we are going to talk +about line broadening and we're going to + + align:start position:0% +about line broadening and we're going to + + + align:start position:0% +about line broadening and we're going to +finish off spectroscopy so see you on + + align:start position:0% + + + + align:start position:0% + +Tuesday \ No newline at end of file diff --git a/BZzkyqe6KD8.txt b/BZzkyqe6KD8.txt new file mode 100644 index 0000000000000000000000000000000000000000..e060f2f303f4e552fce43b88c19728644e0affde --- /dev/null +++ b/BZzkyqe6KD8.txt @@ -0,0 +1,8715 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +to view additional materials from + + align:start position:0% +to view additional materials from + + + align:start position:0% +to view additional materials from +hundreds of MIT courses visit MIT open + + align:start position:0% +hundreds of MIT courses visit MIT open + + + align:start position:0% +hundreds of MIT courses visit MIT open +courseware at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu so this is on oxidation + + align:start position:0% +ocw.mit.edu so this is on oxidation + + + align:start position:0% +ocw.mit.edu so this is on oxidation +reduction go okay so the demo uh + + align:start position:0% +reduction go okay so the demo uh + + + align:start position:0% +reduction go okay so the demo uh +involves a strip of magnesium and the + + align:start position:0% +involves a strip of magnesium and the + + + align:start position:0% +involves a strip of magnesium and the +Magnesium is a pretty reactive metal + + align:start position:0% +Magnesium is a pretty reactive metal + + + align:start position:0% +Magnesium is a pretty reactive metal +right now it's coated with magnesium + + align:start position:0% +right now it's coated with magnesium + + + align:start position:0% +right now it's coated with magnesium +oxide and what I'm going to do is I'm + + align:start position:0% +oxide and what I'm going to do is I'm + + + align:start position:0% +oxide and what I'm going to do is I'm +going to light it on fire when it gets + + align:start position:0% +going to light it on fire when it gets + + + align:start position:0% +going to light it on fire when it gets +lit uh it's going to Glow very very + + align:start position:0% +lit uh it's going to Glow very very + + + align:start position:0% +lit uh it's going to Glow very very +brightly and it's going to react with + + align:start position:0% +brightly and it's going to react with + + + align:start position:0% +brightly and it's going to react with +this block of carbon dioxide uh and + + align:start position:0% +this block of carbon dioxide uh and + + + align:start position:0% +this block of carbon dioxide uh and +magnesium oxide is what you have up + + align:start position:0% +magnesium oxide is what you have up + + + align:start position:0% +magnesium oxide is what you have up +there both of those magnesium oxide + + align:start position:0% +there both of those magnesium oxide + + + align:start position:0% +there both of those magnesium oxide +molecules will react with one molecule + + align:start position:0% +molecules will react with one molecule + + + align:start position:0% +molecules will react with one molecule +of carbon dioxide to form just graphine + + align:start position:0% +of carbon dioxide to form just graphine + + + align:start position:0% +of carbon dioxide to form just graphine +carbon as well as magnesium dioxide so + + align:start position:0% +carbon as well as magnesium dioxide so + + + align:start position:0% +carbon as well as magnesium dioxide so +you're going to get like a white and + + align:start position:0% +you're going to get like a white and + + + align:start position:0% +you're going to get like a white and +black powder inside of here and it's + + align:start position:0% +black powder inside of here and it's + + + align:start position:0% +black powder inside of here and it's +going to be really bright and really + + align:start position:0% +going to be really bright and really + + + align:start position:0% +going to be really bright and really +dangerous and can we lower the lights is + + align:start position:0% +dangerous and can we lower the lights is + + + align:start position:0% +dangerous and can we lower the lights is +that something we can do because that + + align:start position:0% +that something we can do because that + + + align:start position:0% +that something we can do because that +makes it a whole lot more + + align:start position:0% + + + + align:start position:0% + +fun which which was two again two was + + align:start position:0% +fun which which was two again two was + + + align:start position:0% +fun which which was two again two was +the smiley the res one and three was EXC + + align:start position:0% + + + + align:start position:0% + +going try it one more time okay + + align:start position:0% + + + + align:start position:0% + +all + + align:start position:0% +all + + + align:start position:0% +all +right okay good + + align:start position:0% +right okay good + + + align:start position:0% +right okay good +try so oxidation reductions are really + + align:start position:0% +try so oxidation reductions are really + + + align:start position:0% +try so oxidation reductions are really +fun and so we're going to continue and + + align:start position:0% +fun and so we're going to continue and + + + align:start position:0% +fun and so we're going to continue and +tell you about those on Friday so + + align:start position:0% +tell you about those on Friday so + + + align:start position:0% +tell you about those on Friday so +oxidation reduction or redo so redo is + + align:start position:0% +oxidation reduction or redo so redo is + + + align:start position:0% +oxidation reduction or redo so redo is +the uh short hand for oxidation + + align:start position:0% +the uh short hand for oxidation + + + align:start position:0% +the uh short hand for oxidation +reduction um let's bring out your hands + + align:start position:0% +reduction um let's bring out your hands + + + align:start position:0% +reduction um let's bring out your hands +but let's bring the noise level down + + align:start position:0% +but let's bring the noise level down + + + align:start position:0% +but let's bring the noise level down +people have still been complaining about + + align:start position:0% +people have still been complaining about + + + align:start position:0% +people have still been complaining about +noise in class all right so um a Redux + + align:start position:0% +noise in class all right so um a Redux + + + align:start position:0% +noise in class all right so um a Redux +reaction chemical reaction that involves + + align:start position:0% +reaction chemical reaction that involves + + + align:start position:0% +reaction chemical reaction that involves +an exchange of electrons and so we saw + + align:start position:0% +an exchange of electrons and so we saw + + + align:start position:0% +an exchange of electrons and so we saw +uh what happens when we mix this with uh + + align:start position:0% +uh what happens when we mix this with uh + + + align:start position:0% +uh what happens when we mix this with uh +with uh some uh dry ice all right so + + align:start position:0% +with uh some uh dry ice all right so + + + align:start position:0% +with uh some uh dry ice all right so +let's do some definitions we always + + align:start position:0% +let's do some definitions we always + + + align:start position:0% +let's do some definitions we always +start units with definitions and most of + + align:start position:0% +start units with definitions and most of + + + align:start position:0% +start units with definitions and most of +you know some of these definitions + + align:start position:0% +you know some of these definitions + + + align:start position:0% +you know some of these definitions +already + + align:start position:0% +already + + + align:start position:0% +already +oxidation electron + + align:start position:0% +oxidation electron + + + align:start position:0% +oxidation electron +loss + + align:start position:0% +loss + + + align:start position:0% +loss +reduction electron are + + align:start position:0% +reduction electron are + + + align:start position:0% +reduction electron are +gained this one you may or may not be + + align:start position:0% +gained this one you may or may not be + + + align:start position:0% +gained this one you may or may not be +familiar with oxid oxidizing agent it + + align:start position:0% +familiar with oxid oxidizing agent it + + + align:start position:0% +familiar with oxid oxidizing agent it +accepts electrons so it oxidizes other + + align:start position:0% +accepts electrons so it oxidizes other + + + align:start position:0% +accepts electrons so it oxidizes other +things but it itself is + + align:start position:0% +things but it itself is + + + align:start position:0% +things but it itself is +reduced and reducing agent donates + + align:start position:0% +reduced and reducing agent donates + + + align:start position:0% +reduced and reducing agent donates +electrons it reduces other things it + + align:start position:0% +electrons it reduces other things it + + + align:start position:0% +electrons it reduces other things it +itself is oxidized and before you turn + + align:start position:0% +itself is oxidized and before you turn + + + align:start position:0% +itself is oxidized and before you turn +the page uh I just want to try to get + + align:start position:0% +the page uh I just want to try to get + + + align:start position:0% +the page uh I just want to try to get +you to remember these two terms so one + + align:start position:0% +you to remember these two terms so one + + + align:start position:0% +you to remember these two terms so one +way that I like to think about it is + + align:start position:0% +way that I like to think about it is + + + align:start position:0% +way that I like to think about it is +that a reducing agent might be somebody + + align:start position:0% +that a reducing agent might be somebody + + + align:start position:0% +that a reducing agent might be somebody +who is uh a little bit Shady they might + + align:start position:0% +who is uh a little bit Shady they might + + + align:start position:0% +who is uh a little bit Shady they might +walk up to someone and say in a crowded + + align:start position:0% +walk up to someone and say in a crowded + + + align:start position:0% +walk up to someone and say in a crowded +space don't look at me just + + align:start position:0% +space don't look at me just + + + align:start position:0% +space don't look at me just +listen did you want to buy an + + align:start position:0% +listen did you want to buy an + + + align:start position:0% +listen did you want to buy an +electron so that would be an agent of + + align:start position:0% +electron so that would be an agent of + + + align:start position:0% +electron so that would be an agent of +reduction going around now there could + + align:start position:0% +reduction going around now there could + + + align:start position:0% +reduction going around now there could +be ones that are a little bit Shady + + align:start position:0% +be ones that are a little bit Shady + + + align:start position:0% +be ones that are a little bit Shady +selling electrons to the highest bidder + + align:start position:0% +selling electrons to the highest bidder + + + align:start position:0% +selling electrons to the highest bidder +but there could also be agents of good + + align:start position:0% +but there could also be agents of good + + + align:start position:0% +but there could also be agents of good +I told you about free radical species + + align:start position:0% +I told you about free radical species + + + align:start position:0% +I told you about free radical species +there's a lot of free radicals in the + + align:start position:0% +there's a lot of free radicals in the + + + align:start position:0% +there's a lot of free radicals in the +universe they can be dangerous because + + align:start position:0% +universe they can be dangerous because + + + align:start position:0% +universe they can be dangerous because +they have a single unpaired electron + + align:start position:0% +they have a single unpaired electron + + + align:start position:0% +they have a single unpaired electron +which makes them really highly reactive + + align:start position:0% +which makes them really highly reactive + + + align:start position:0% +which makes them really highly reactive +so there might be an agent a secret + + align:start position:0% +so there might be an agent a secret + + + align:start position:0% +so there might be an agent a secret +agent of + + align:start position:0% +agent of + + + align:start position:0% +agent of +oxidation and it might want to Shield + + align:start position:0% +oxidation and it might want to Shield + + + align:start position:0% +oxidation and it might want to Shield +the universe from the power of free + + align:start position:0% +the universe from the power of free + + + align:start position:0% +the universe from the power of free +radicals and so it would go along and it + + align:start position:0% +radicals and so it would go along and it + + + align:start position:0% +radicals and so it would go along and it +would oxidize that give it give it take + + align:start position:0% +would oxidize that give it give it take + + + align:start position:0% +would oxidize that give it give it take +that that electron away and oxidize it + + align:start position:0% +that that electron away and oxidize it + + + align:start position:0% +that that electron away and oxidize it +and become reduced itself take that free + + align:start position:0% +and become reduced itself take that free + + + align:start position:0% +and become reduced itself take that free +radical away because the free radical + + align:start position:0% +radical away because the free radical + + + align:start position:0% +radical away because the free radical +species might not know how dangerous it + + align:start position:0% +species might not know how dangerous it + + + align:start position:0% +species might not know how dangerous it +is it's for everybody's good to Shield + + align:start position:0% +is it's for everybody's good to Shield + + + align:start position:0% +is it's for everybody's good to Shield +you from that power you might also have + + align:start position:0% +you from that power you might also have + + + align:start position:0% +you from that power you might also have +an agent of reduction that's a secret + + align:start position:0% +an agent of reduction that's a secret + + + align:start position:0% +an agent of reduction that's a secret +agent that might go up to the free + + align:start position:0% +agent that might go up to the free + + + align:start position:0% +agent that might go up to the free +radical species and give it an extra + + align:start position:0% +radical species and give it an extra + + + align:start position:0% +radical species and give it an extra +electron and then it has two and then + + align:start position:0% +electron and then it has two and then + + + align:start position:0% +electron and then it has two and then +it's more stable and less reactive so + + align:start position:0% +it's more stable and less reactive so + + + align:start position:0% +it's more stable and less reactive so +you might have these agents so that's + + align:start position:0% +you might have these agents so that's + + + align:start position:0% +you might have these agents so that's +how you should think about it think + + align:start position:0% +how you should think about it think + + + align:start position:0% +how you should think about it think +about an agent of oxidation it wants to + + align:start position:0% +about an agent of oxidation it wants to + + + align:start position:0% +about an agent of oxidation it wants to +go out and oxidize for the good of + + align:start position:0% +go out and oxidize for the good of + + + align:start position:0% +go out and oxidize for the good of +mankind or an agent of reduction that + + align:start position:0% +mankind or an agent of reduction that + + + align:start position:0% +mankind or an agent of reduction that +wants to go out and reduce other + + align:start position:0% +wants to go out and reduce other + + + align:start position:0% +wants to go out and reduce other +things so that might help you remember + + align:start position:0% +things so that might help you remember + + + align:start position:0% +things so that might help you remember +those those definitions we'll we'll hope + + align:start position:0% +those those definitions we'll we'll hope + + + align:start position:0% +those those definitions we'll we'll hope +so all right so let's take a look now we + + align:start position:0% +so all right so let's take a look now we + + + align:start position:0% +so all right so let's take a look now we +always start every unit with definitions + + align:start position:0% +always start every unit with definitions + + + align:start position:0% +always start every unit with definitions +and then we have a set of rules and + + align:start position:0% +and then we have a set of rules and + + + align:start position:0% +and then we have a set of rules and +guidelines so let's take a look at the + + align:start position:0% +guidelines so let's take a look at the + + + align:start position:0% +guidelines so let's take a look at the +guidelines luckily these guidelines are + + align:start position:0% +guidelines luckily these guidelines are + + + align:start position:0% +guidelines luckily these guidelines are +really pretty straightforward and you + + align:start position:0% +really pretty straightforward and you + + + align:start position:0% +really pretty straightforward and you +really shouldn't have a lot of + + align:start position:0% +really shouldn't have a lot of + + + align:start position:0% +really shouldn't have a lot of +difficulty keeping them in mind some of + + align:start position:0% +difficulty keeping them in mind some of + + + align:start position:0% +difficulty keeping them in mind some of +them we've really seen already we just + + align:start position:0% +them we've really seen already we just + + + align:start position:0% +them we've really seen already we just +didn't realize that they were going to + + align:start position:0% +didn't realize that they were going to + + + align:start position:0% +didn't realize that they were going to +be the guidelines that we would have so + + align:start position:0% +be the guidelines that we would have so + + + align:start position:0% +be the guidelines that we would have so +guidelines for assigning oxidation + + align:start position:0% +guidelines for assigning oxidation + + + align:start position:0% +guidelines for assigning oxidation +numbers in a free element every atom has + + align:start position:0% +numbers in a free element every atom has + + + align:start position:0% +numbers in a free element every atom has +an oxidation number of + + align:start position:0% +an oxidation number of + + + align:start position:0% +an oxidation number of +zero okay that seems pretty + + align:start position:0% +zero okay that seems pretty + + + align:start position:0% +zero okay that seems pretty +straightforward H2 oxidation number + + align:start position:0% +straightforward H2 oxidation number + + + align:start position:0% +straightforward H2 oxidation number +zero rule + + align:start position:0% +zero rule + + + align:start position:0% +zero rule +two ions composed of only one atom also + + align:start position:0% +two ions composed of only one atom also + + + align:start position:0% +two ions composed of only one atom also +called monatomic ions + + align:start position:0% +called monatomic ions + + + align:start position:0% +called monatomic ions +have an oxidation number that's equal to + + align:start position:0% +have an oxidation number that's equal to + + + align:start position:0% +have an oxidation number that's equal to +their charge if this wasn't true it + + align:start position:0% +their charge if this wasn't true it + + + align:start position:0% +their charge if this wasn't true it +would be deeply disturbing lithium plus + + align:start position:0% +would be deeply disturbing lithium plus + + + align:start position:0% +would be deeply disturbing lithium plus +one ions has an oxidation number of plus + + align:start position:0% +one ions has an oxidation number of plus + + + align:start position:0% +one ions has an oxidation number of plus +one I think we're good okay also in + + align:start position:0% +one I think we're good okay also in + + + align:start position:0% +one I think we're good okay also in +number two in forming compounds group + + align:start position:0% +number two in forming compounds group + + + align:start position:0% +number two in forming compounds group +one metals have an oxidation number of + + align:start position:0% +one metals have an oxidation number of + + + align:start position:0% +one metals have an oxidation number of +plus one lithium and all of its friends + + align:start position:0% +plus one lithium and all of its friends + + + align:start position:0% +plus one lithium and all of its friends +sodium Etc group two metals have an + + align:start position:0% +sodium Etc group two metals have an + + + align:start position:0% +sodium Etc group two metals have an +oxidation number of plus two calcium for + + align:start position:0% +oxidation number of plus two calcium for + + + align:start position:0% +oxidation number of plus two calcium for +example and aluminum is plus three in + + align:start position:0% +example and aluminum is plus three in + + + align:start position:0% +example and aluminum is plus three in +its compounds this is also something + + align:start position:0% +its compounds this is also something + + + align:start position:0% +its compounds this is also something +that we've seen before those group one + + align:start position:0% +that we've seen before those group one + + + align:start position:0% +that we've seen before those group one +and group two metals are not all that + + align:start position:0% +and group two metals are not all that + + + align:start position:0% +and group two metals are not all that +exciting they pretty much want to get + + align:start position:0% +exciting they pretty much want to get + + + align:start position:0% +exciting they pretty much want to get +their noble gas configuration and they + + align:start position:0% +their noble gas configuration and they + + + align:start position:0% +their noble gas configuration and they +want to lose either one if you're in + + align:start position:0% +want to lose either one if you're in + + + align:start position:0% +want to lose either one if you're in +group one or two electrons if you're in + + align:start position:0% +group one or two electrons if you're in + + + align:start position:0% +group one or two electrons if you're in +group two and so that's what they do + + align:start position:0% +group two and so that's what they do + + + align:start position:0% +group two and so that's what they do +here so this is good to keep in mind + + align:start position:0% +here so this is good to keep in mind + + + align:start position:0% +here so this is good to keep in mind +because it's going to help you with o + + align:start position:0% +because it's going to help you with o + + + align:start position:0% +because it's going to help you with o +figure out the oxidation number of other + + align:start position:0% +figure out the oxidation number of other + + + align:start position:0% +figure out the oxidation number of other +elements for which there are not such + + align:start position:0% +elements for which there are not such + + + align:start position:0% +elements for which there are not such +hard and fast rules + + align:start position:0% +hard and fast rules + + + align:start position:0% +hard and fast rules +number three + + align:start position:0% +number three + + + align:start position:0% +number three +oxygen oxygen in most compounds is + + align:start position:0% +oxygen oxygen in most compounds is + + + align:start position:0% +oxygen oxygen in most compounds is +min-2 again not that surprising that it + + align:start position:0% +min-2 again not that surprising that it + + + align:start position:0% +min-2 again not that surprising that it +would want to uh gain those two + + align:start position:0% +would want to uh gain those two + + + align:start position:0% +would want to uh gain those two +electrons however there's some + + align:start position:0% +electrons however there's some + + + align:start position:0% +electrons however there's some +exceptions oxygen is just an element + + align:start position:0% +exceptions oxygen is just an element + + + align:start position:0% +exceptions oxygen is just an element +full of exceptions um if it is in + + align:start position:0% +full of exceptions um if it is in + + + align:start position:0% +full of exceptions um if it is in +peroxides hydrogen peroxide o O2 2 minus + + align:start position:0% +peroxides hydrogen peroxide o O2 2 minus + + + align:start position:0% +peroxides hydrogen peroxide o O2 2 minus +then it's going to have an oxidation + + align:start position:0% +then it's going to have an oxidation + + + align:start position:0% +then it's going to have an oxidation +number of + + align:start position:0% +number of + + + align:start position:0% +number of +minus1 so peroxides and later we'll see + + align:start position:0% +minus1 so peroxides and later we'll see + + + align:start position:0% +minus1 so peroxides and later we'll see +super oxides are exceptions but if it's + + align:start position:0% +super oxides are exceptions but if it's + + + align:start position:0% +super oxides are exceptions but if it's +not a peroxide or a super oxide it's + + align:start position:0% +not a peroxide or a super oxide it's + + + align:start position:0% +not a peroxide or a super oxide it's +going to be minus + + align:start position:0% +going to be minus + + + align:start position:0% +going to be minus +two all right rule number four + + align:start position:0% +two all right rule number four + + + align:start position:0% +two all right rule number four +hydrogen hydrogen is O mostly plus one + + align:start position:0% +hydrogen hydrogen is O mostly plus one + + + align:start position:0% +hydrogen hydrogen is O mostly plus one +we probably could guess that but there + + align:start position:0% +we probably could guess that but there + + + align:start position:0% +we probably could guess that but there +actually are some exceptions for this + + align:start position:0% +actually are some exceptions for this + + + align:start position:0% +actually are some exceptions for this +and you're going to see a lot of those + + align:start position:0% +and you're going to see a lot of those + + + align:start position:0% +and you're going to see a lot of those +exceptions in this unit and pretty much + + align:start position:0% +exceptions in this unit and pretty much + + + align:start position:0% +exceptions in this unit and pretty much +after this unit not so much ever again + + align:start position:0% +after this unit not so much ever again + + + align:start position:0% +after this unit not so much ever again +the exceptions are for the group one and + + align:start position:0% +the exceptions are for the group one and + + + align:start position:0% +the exceptions are for the group one and +the group two so the group one and group + + align:start position:0% +the group two so the group one and group + + + align:start position:0% +the group two so the group one and group +two rules supersede the fact that + + align:start position:0% +two rules supersede the fact that + + + align:start position:0% +two rules supersede the fact that +hydrogen is usually plus one so if you + + align:start position:0% +hydrogen is usually plus one so if you + + + align:start position:0% +hydrogen is usually plus one so if you +have hydrogen with lithium lithium is + + align:start position:0% +have hydrogen with lithium lithium is + + + align:start position:0% +have hydrogen with lithium lithium is +going to be plus one so hydrogen will be + + align:start position:0% +going to be plus one so hydrogen will be + + + align:start position:0% +going to be plus one so hydrogen will be +minus one sodium is is the same here and + + align:start position:0% +minus one sodium is is the same here and + + + align:start position:0% +minus one sodium is is the same here and +calcium that's group two again hydrogen + + align:start position:0% +calcium that's group two again hydrogen + + + align:start position:0% +calcium that's group two again hydrogen +would be minus one so group one group + + align:start position:0% +would be minus one so group one group + + + align:start position:0% +would be minus one so group one group +two rules supersede + + align:start position:0% +two rules supersede + + + align:start position:0% +two rules supersede +hydrogen all right what about our + + align:start position:0% +hydrogen all right what about our + + + align:start position:0% +hydrogen all right what about our +halides we have Florine it wants to be + + align:start position:0% +halides we have Florine it wants to be + + + align:start position:0% +halides we have Florine it wants to be +minus one other halogens chloride + + align:start position:0% +minus one other halogens chloride + + + align:start position:0% +minus one other halogens chloride +bromide iodide are negative when they + + align:start position:0% +bromide iodide are negative when they + + + align:start position:0% +bromide iodide are negative when they +are in + + align:start position:0% +are in + + + align:start position:0% +are in +salts um such as sodium chloride but if + + align:start position:0% +salts um such as sodium chloride but if + + + align:start position:0% +salts um such as sodium chloride but if +oxygen is there the oxygen rules are the + + align:start position:0% +oxygen is there the oxygen rules are the + + + align:start position:0% +oxygen is there the oxygen rules are the +ones that follow so here um if you have + + align:start position:0% +ones that follow so here um if you have + + + align:start position:0% +ones that follow so here um if you have +CL with oxygen then you're going to have + + align:start position:0% +CL with oxygen then you're going to have + + + align:start position:0% +CL with oxygen then you're going to have +a positive oxidation number for the + + align:start position:0% +a positive oxidation number for the + + + align:start position:0% +a positive oxidation number for the +chlorine because oxygen is going to be + + align:start position:0% +chlorine because oxygen is going to be + + + align:start position:0% +chlorine because oxygen is going to be +minus + + align:start position:0% +minus + + + align:start position:0% +minus +two all right and and you'll see a + + align:start position:0% +two all right and and you'll see a + + + align:start position:0% +two all right and and you'll see a +number of these so-called oxy acids in + + align:start position:0% +number of these so-called oxy acids in + + + align:start position:0% +number of these so-called oxy acids in +this + + align:start position:0% +this + + + align:start position:0% +this +unit all right + + align:start position:0% +unit all right + + + align:start position:0% +unit all right +six this one you probably already know + + align:start position:0% +six this one you probably already know + + + align:start position:0% +six this one you probably already know +but in a neutral mod molecule the sums + + align:start position:0% +but in a neutral mod molecule the sums + + + align:start position:0% +but in a neutral mod molecule the sums +of the oxidation numbers must equal zero + + align:start position:0% +of the oxidation numbers must equal zero + + + align:start position:0% +of the oxidation numbers must equal zero +so the sums must be neutral if the + + align:start position:0% +so the sums must be neutral if the + + + align:start position:0% +so the sums must be neutral if the +molecule is neutral and if you have + + align:start position:0% +molecule is neutral and if you have + + + align:start position:0% +molecule is neutral and if you have +something that is a polyatomic + + align:start position:0% +something that is a polyatomic + + + align:start position:0% +something that is a polyatomic +multi-atom ion the sum + + align:start position:0% +multi-atom ion the sum + + + align:start position:0% +multi-atom ion the sum +of the individual oxidation numbers + + align:start position:0% +of the individual oxidation numbers + + + align:start position:0% +of the individual oxidation numbers +needs to be equal to the overall charge + + align:start position:0% +needs to be equal to the overall charge + + + align:start position:0% +needs to be equal to the overall charge +on that ion so again we've seen things + + align:start position:0% +on that ion so again we've seen things + + + align:start position:0% +on that ion so again we've seen things +like this before um so we should have no + + align:start position:0% +like this before um so we should have no + + + align:start position:0% +like this before um so we should have no +trouble with these rules okay so let's + + align:start position:0% +trouble with these rules okay so let's + + + align:start position:0% +trouble with these rules okay so let's +just look an example of this suppose we + + align:start position:0% +just look an example of this suppose we + + + align:start position:0% +just look an example of this suppose we +have our friend + + align:start position:0% +have our friend + + + align:start position:0% +have our friend +nh4+ what is hydrogen's uh oxidation + + align:start position:0% +nh4+ what is hydrogen's uh oxidation + + + align:start position:0% +nh4+ what is hydrogen's uh oxidation +number going to be in this + + align:start position:0% +number going to be in this + + + align:start position:0% +number going to be in this +molecule it'll be+ one so it's not with + + align:start position:0% +molecule it'll be+ one so it's not with + + + align:start position:0% +molecule it'll be+ one so it's not with +a group one or group two + + align:start position:0% +a group one or group two + + + align:start position:0% +a group one or group two +um element so it's going to be plus + + align:start position:0% +um element so it's going to be plus + + + align:start position:0% +um element so it's going to be plus +one what about nitrogen there are no + + align:start position:0% +one what about nitrogen there are no + + + align:start position:0% +one what about nitrogen there are no +rules about nitrogen so we have to + + align:start position:0% +rules about nitrogen so we have to + + + align:start position:0% +rules about nitrogen so we have to +figure out based on the other rules what + + align:start position:0% +figure out based on the other rules what + + + align:start position:0% +figure out based on the other rules what +the oxidation number of nitrogen will be + + align:start position:0% +the oxidation number of nitrogen will be + + + align:start position:0% +the oxidation number of nitrogen will be +what is it going to be here it's going + + align:start position:0% +what is it going to be here it's going + + + align:start position:0% +what is it going to be here it's going +to be minus three and the reason for + + align:start position:0% +to be minus three and the reason for + + + align:start position:0% +to be minus three and the reason for +that is because of the rule we just + + align:start position:0% +that is because of the rule we just + + + align:start position:0% +that is because of the rule we just +talked about that the sum needs of the + + align:start position:0% +talked about that the sum needs of the + + + align:start position:0% +talked about that the sum needs of the +oxidation numbers needs to be equal to + + align:start position:0% +oxidation numbers needs to be equal to + + + align:start position:0% +oxidation numbers needs to be equal to +the charge on the molecule the charge is + + align:start position:0% +the charge on the molecule the charge is + + + align:start position:0% +the charge on the molecule the charge is +plus one so we have four hydrogens four + + align:start position:0% +plus one so we have four hydrogens four + + + align:start position:0% +plus one so we have four hydrogens four +plus plus 1 minus 3 is going to equal + + + align:start position:0% +plus plus 1 minus 3 is going to equal + + + + align:start position:0% +plus plus 1 minus 3 is going to equal + +one so nitrogen had to be minus three + + align:start position:0% +one so nitrogen had to be minus three + + + align:start position:0% +one so nitrogen had to be minus three +nitrogen can have a lot of different + + align:start position:0% +nitrogen can have a lot of different + + + align:start position:0% +nitrogen can have a lot of different +numbers so you want to pay attention to + + align:start position:0% +numbers so you want to pay attention to + + + align:start position:0% +numbers so you want to pay attention to +what's around it and whether they're + + align:start position:0% +what's around it and whether they're + + + align:start position:0% +what's around it and whether they're +rules or guidelines about those other + + align:start position:0% +rules or guidelines about those other + + + align:start position:0% +rules or guidelines about those other +elements all + + align:start position:0% +elements all + + + align:start position:0% +elements all +right seven oxidation numbers don't have + + align:start position:0% +right seven oxidation numbers don't have + + + align:start position:0% +right seven oxidation numbers don't have +to be integers they almost always are + + align:start position:0% +to be integers they almost always are + + + align:start position:0% +to be integers they almost always are +but there is one notable exception and + + align:start position:0% +but there is one notable exception and + + + align:start position:0% +but there is one notable exception and +it's from oxygen perhaps not a surprise + + align:start position:0% +it's from oxygen perhaps not a surprise + + + align:start position:0% +it's from oxygen perhaps not a surprise +oxygen is always causing trouble so in + + align:start position:0% +oxygen is always causing trouble so in + + + align:start position:0% +oxygen is always causing trouble so in +super oxide you have O2 + + align:start position:0% +super oxide you have O2 + + + align:start position:0% +super oxide you have O2 +minus1 so what is the oxidation number + + align:start position:0% +minus1 so what is the oxidation number + + + align:start position:0% +minus1 so what is the oxidation number +on each oxygen in that O2 minus one + + align:start position:0% +on each oxygen in that O2 minus one + + + align:start position:0% +on each oxygen in that O2 minus one +molecule yep so it's minus + + align:start position:0% +molecule yep so it's minus + + + align:start position:0% +molecule yep so it's minus +one2 so oxygen is usually minus two + + align:start position:0% +one2 so oxygen is usually minus two + + + align:start position:0% +one2 so oxygen is usually minus two +except in peroxides and super + + align:start position:0% +except in peroxides and super + + + align:start position:0% +except in peroxides and super +oxides all right so let's take a look at + + align:start position:0% +oxides all right so let's take a look at + + + align:start position:0% +oxides all right so let's take a look at +some examples and I'll write some of + + align:start position:0% +some examples and I'll write some of + + + align:start position:0% +some examples and I'll write some of +these on the board and here are all of + + align:start position:0% +these on the board and here are all of + + + align:start position:0% +these on the board and here are all of +your rules so you can yell out what you + + align:start position:0% +your rules so you can yell out what you + + + align:start position:0% +your rules so you can yell out what you +think um I should be doing with these as + + align:start position:0% +think um I should be doing with these as + + + align:start position:0% +think um I should be doing with these as +we go + + align:start position:0% +we go + + + align:start position:0% +we go +along okay so we have lithium + + align:start position:0% +along okay so we have lithium + + + align:start position:0% +along okay so we have lithium +to oxide so here we know a lot about + + align:start position:0% +to oxide so here we know a lot about + + + align:start position:0% +to oxide so here we know a lot about +this what's the oxygen going to + + align:start position:0% +this what's the oxygen going to + + + align:start position:0% +this what's the oxygen going to +be minus two the overall charge on the + + align:start position:0% +be minus two the overall charge on the + + + align:start position:0% +be minus two the overall charge on the +molecule is zero and we have two + + align:start position:0% +molecule is zero and we have two + + + align:start position:0% +molecule is zero and we have two +lithiums and what's the charge on each + + align:start position:0% +lithiums and what's the charge on each + + + align:start position:0% +lithiums and what's the charge on each +one + one and so + 2 - 2 is zero + + align:start position:0% +one + one and so + 2 - 2 is zero + + + align:start position:0% +one + one and so + 2 - 2 is zero +great let's do another one we'll do + + align:start position:0% +great let's do another one we'll do + + + align:start position:0% +great let's do another one we'll do +PCL 5 + + align:start position:0% +PCL 5 + + + align:start position:0% +PCL 5 +next so what do we know about CL what + + align:start position:0% +next so what do we know about CL what + + + align:start position:0% +next so what do we know about CL what +charge do we expect + + align:start position:0% +charge do we expect + + + align:start position:0% +charge do we expect +here minus one and there are five of + + align:start position:0% +here minus one and there are five of + + + align:start position:0% +here minus one and there are five of +those so chlorine likes to be minus1 + + align:start position:0% +those so chlorine likes to be minus1 + + + align:start position:0% +those so chlorine likes to be minus1 +exception is with oxy o but it's not + + align:start position:0% +exception is with oxy o but it's not + + + align:start position:0% +exception is with oxy o but it's not +with oxygen here the overall charge is + + align:start position:0% +with oxygen here the overall charge is + + + align:start position:0% +with oxygen here the overall charge is +going to be zero because it's a neutral + + align:start position:0% +going to be zero because it's a neutral + + + align:start position:0% +going to be zero because it's a neutral +molecule so what does that mean about + + align:start position:0% +molecule so what does that mean about + + + align:start position:0% +molecule so what does that mean about +the charge on our + + align:start position:0% +the charge on our + + + align:start position:0% +the charge on our +phosphorus plus + + align:start position:0% +phosphorus plus + + + align:start position:0% +phosphorus plus +five + + align:start position:0% +five + + + align:start position:0% +five +right okay so now let's + + align:start position:0% +right okay so now let's + + + align:start position:0% +right okay so now let's +try + + align:start position:0% +try + + + align:start position:0% +try +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +hno3 so let's do oxygen first what + + align:start position:0% +hno3 so let's do oxygen first what + + + align:start position:0% +hno3 so let's do oxygen first what +charge we expect on + + align:start position:0% +charge we expect on + + + align:start position:0% +charge we expect on +oxygen - two so we three of those minus + + align:start position:0% +oxygen - two so we three of those minus + + + align:start position:0% +oxygen - two so we three of those minus +2 overall this is going to be zero + + align:start position:0% +2 overall this is going to be zero + + + align:start position:0% +2 overall this is going to be zero +nitrogen can be varied so let's do + + align:start position:0% +nitrogen can be varied so let's do + + + align:start position:0% +nitrogen can be varied so let's do +hydrogen what do we expect hydrogen to + + align:start position:0% +hydrogen what do we expect hydrogen to + + + align:start position:0% +hydrogen what do we expect hydrogen to +be plus one right it's not with a group + + align:start position:0% +be plus one right it's not with a group + + + align:start position:0% +be plus one right it's not with a group +one or group two so what is that leave + + align:start position:0% +one or group two so what is that leave + + + align:start position:0% +one or group two so what is that leave +for + + align:start position:0% +for + + + align:start position:0% +for +nitrogen plus + + align:start position:0% +nitrogen plus + + + align:start position:0% +nitrogen plus +five so we have plus six then minus 6 is + + align:start position:0% +five so we have plus six then minus 6 is + + + align:start position:0% +five so we have plus six then minus 6 is +zero all right so why don't you try the + + align:start position:0% +zero all right so why don't you try the + + + align:start position:0% +zero all right so why don't you try the +next one as a clicker + + align:start position:0% + + + + align:start position:0% + +question all right 10 more seconds + + align:start position:0% + + + + align:start position:0% + +yep so oxygen is minus two it's not in a + + align:start position:0% +yep so oxygen is minus two it's not in a + + + align:start position:0% +yep so oxygen is minus two it's not in a +peroxide um or a super oxide the overall + + align:start position:0% +peroxide um or a super oxide the overall + + + align:start position:0% +peroxide um or a super oxide the overall +charge is zero so that means that each + + align:start position:0% +charge is zero so that means that each + + + align:start position:0% +charge is zero so that means that each +nitrogen must be+ one so we have plus + + align:start position:0% +nitrogen must be+ one so we have plus + + + align:start position:0% +nitrogen must be+ one so we have plus +two minus 2 is + + align:start position:0% +two minus 2 is + + + align:start position:0% +two minus 2 is +zero yeah what exactly a peroxide a + + align:start position:0% +zero yeah what exactly a peroxide a + + + align:start position:0% +zero yeah what exactly a peroxide a +peroxide so um they're really only those + + align:start position:0% +peroxide so um they're really only those + + + align:start position:0% +peroxide so um they're really only those +the hydrogen peroxide example so it'll + + align:start position:0% +the hydrogen peroxide example so it'll + + + align:start position:0% +the hydrogen peroxide example so it'll +it'll say that it's a peroxide so or a + + align:start position:0% +it'll say that it's a peroxide so or a + + + align:start position:0% +it'll say that it's a peroxide so or a +super oxide yeah so don't don't wor you + + align:start position:0% +super oxide yeah so don't don't wor you + + + align:start position:0% +super oxide yeah so don't don't wor you +don't have to worry about that it's + + align:start position:0% +don't have to worry about that it's + + + align:start position:0% +don't have to worry about that it's +going to be + + align:start position:0% + + + + align:start position:0% + +clear okay good so + + align:start position:0% +clear okay good so + + + align:start position:0% +clear okay good so +now let's talk about some reactions that + + align:start position:0% +now let's talk about some reactions that + + + align:start position:0% +now let's talk about some reactions that +involve oxidations and reductions and to + + align:start position:0% +involve oxidations and reductions and to + + + align:start position:0% +involve oxidations and reductions and to +talk about these reactions you need to + + align:start position:0% +talk about these reactions you need to + + + align:start position:0% +talk about these reactions you need to +know how to do this and then we're going + + align:start position:0% +know how to do this and then we're going + + + align:start position:0% +know how to do this and then we're going +to talk about balancing reactions and + + align:start position:0% +to talk about balancing reactions and + + + align:start position:0% +to talk about balancing reactions and +you need all of these skills all right + + align:start position:0% +you need all of these skills all right + + + align:start position:0% +you need all of these skills all right +so first I just want to tell you about + + align:start position:0% +so first I just want to tell you about + + + align:start position:0% +so first I just want to tell you about +something called a disproportionation + + align:start position:0% +something called a disproportionation + + + align:start position:0% +something called a disproportionation +reaction where you have one element that + + align:start position:0% +reaction where you have one element that + + + align:start position:0% +reaction where you have one element that +is going to be both oxidized and reduced + + align:start position:0% +is going to be both oxidized and reduced + + + align:start position:0% +is going to be both oxidized and reduced +and this is a good example to allow us + + align:start position:0% +and this is a good example to allow us + + + align:start position:0% +and this is a good example to allow us +to think about what's happening in a + + align:start position:0% +to think about what's happening in a + + + align:start position:0% +to think about what's happening in a +different reaction so in this reaction + + align:start position:0% +different reaction so in this reaction + + + align:start position:0% +different reaction so in this reaction +um the element that is going to be both + + align:start position:0% +um the element that is going to be both + + + align:start position:0% +um the element that is going to be both +oxidized and reduced is CL um sodium is + + align:start position:0% +oxidized and reduced is CL um sodium is + + + align:start position:0% +oxidized and reduced is CL um sodium is +going to be a spectator ion and the + + align:start position:0% +going to be a spectator ion and the + + + align:start position:0% +going to be a spectator ion and the +oxygen is going to uh stay um in it + + align:start position:0% +oxygen is going to uh stay um in it + + + align:start position:0% +oxygen is going to uh stay um in it +min-2 form here and so we have chlorine + + align:start position:0% +min-2 form here and so we have chlorine + + + align:start position:0% +min-2 form here and so we have chlorine +going to chlorine in this compound and + + align:start position:0% +going to chlorine in this compound and + + + align:start position:0% +going to chlorine in this compound and +in this compound so we can break this + + align:start position:0% +in this compound so we can break this + + + align:start position:0% +in this compound so we can break this +down and think about what's happening + + align:start position:0% +down and think about what's happening + + + align:start position:0% +down and think about what's happening +with this species going to this and then + + align:start position:0% +with this species going to this and then + + + align:start position:0% +with this species going to this and then +also going to CL minus so let's think + + align:start position:0% +also going to CL minus so let's think + + + align:start position:0% +also going to CL minus so let's think +about what the oxidation number of + + align:start position:0% +about what the oxidation number of + + + align:start position:0% +about what the oxidation number of +chlorine is in CL minus so first oxygen + + align:start position:0% +chlorine is in CL minus so first oxygen + + + align:start position:0% +chlorine is in CL minus so first oxygen +I already told you is going to be minus + + align:start position:0% +I already told you is going to be minus + + + align:start position:0% +I already told you is going to be minus +two the overall charge on the molecule + + align:start position:0% +two the overall charge on the molecule + + + align:start position:0% +two the overall charge on the molecule +is minus1 so chlorine has to make this + + align:start position:0% +is minus1 so chlorine has to make this + + + align:start position:0% +is minus1 so chlorine has to make this +equation work so what is the oxidation + + align:start position:0% +equation work so what is the oxidation + + + align:start position:0% +equation work so what is the oxidation +number of + + align:start position:0% + + + + align:start position:0% + +Cl plus one thank you so we have plus + + align:start position:0% +Cl plus one thank you so we have plus + + + align:start position:0% +Cl plus one thank you so we have plus +one here now let's take a look at this + + align:start position:0% +one here now let's take a look at this + + + align:start position:0% +one here now let's take a look at this +so oxygen we're going to have as min-2 + + align:start position:0% +so oxygen we're going to have as min-2 + + + align:start position:0% +so oxygen we're going to have as min-2 +there are three of + + align:start position:0% +there are three of + + + align:start position:0% +there are three of +them that's going to equal overall + + align:start position:0% +them that's going to equal overall + + + align:start position:0% +them that's going to equal overall +minus1 so what's the oxidation number of + + align:start position:0% +minus1 so what's the oxidation number of + + + align:start position:0% +minus1 so what's the oxidation number of +chlorine + + align:start position:0% +chlorine + + + align:start position:0% +chlorine +here plus five right so we have a case + + align:start position:0% +here plus five right so we have a case + + + align:start position:0% +here plus five right so we have a case +now where we're going from + one to + + + align:start position:0% +now where we're going from + one to + + + + align:start position:0% +now where we're going from + one to + +5 is that an oxidation or a + + align:start position:0% +5 is that an oxidation or a + + + align:start position:0% +5 is that an oxidation or a +reduction that's an oxidation so we're + + align:start position:0% +reduction that's an oxidation so we're + + + align:start position:0% +reduction that's an oxidation so we're +increasing the number it is losing + + align:start position:0% +increasing the number it is losing + + + align:start position:0% +increasing the number it is losing +electrons it's becoming + + align:start position:0% +electrons it's becoming + + + align:start position:0% +electrons it's becoming +oxidized so down here we already have + + align:start position:0% +oxidized so down here we already have + + + align:start position:0% +oxidized so down here we already have +done all of our work and know that this + + align:start position:0% +done all of our work and know that this + + + align:start position:0% +done all of our work and know that this +is also going to be+ one + + align:start position:0% +is also going to be+ one + + + align:start position:0% +is also going to be+ one +so in this case we're going from + one + + align:start position:0% +so in this case we're going from + one + + + align:start position:0% +so in this case we're going from + one +to minus1 is that an oxidation or a + + align:start position:0% +to minus1 is that an oxidation or a + + + align:start position:0% +to minus1 is that an oxidation or a +reduction that's a reduction and that's + + align:start position:0% +reduction that's a reduction and that's + + + align:start position:0% +reduction that's a reduction and that's +good because it wouldn't be a very good + + align:start position:0% +good because it wouldn't be a very good + + + align:start position:0% +good because it wouldn't be a very good +disproportionation reaction otherwise + + align:start position:0% +disproportionation reaction otherwise + + + align:start position:0% +disproportionation reaction otherwise +something has to be oxidized same thing + + align:start position:0% +something has to be oxidized same thing + + + align:start position:0% +something has to be oxidized same thing +has to be oxidized and reduced so this + + align:start position:0% +has to be oxidized and reduced so this + + + align:start position:0% +has to be oxidized and reduced so this +is uh how you think about about this + + align:start position:0% +is uh how you think about about this + + + align:start position:0% +is uh how you think about about this +type of reaction so to consider whether + + align:start position:0% +type of reaction so to consider whether + + + align:start position:0% +type of reaction so to consider whether +something's being oxidized or reduced + + align:start position:0% +something's being oxidized or reduced + + + align:start position:0% +something's being oxidized or reduced +you need to be able to dissect out what + + align:start position:0% +you need to be able to dissect out what + + + align:start position:0% +you need to be able to dissect out what +the oxidation numbers + + align:start position:0% +the oxidation numbers + + + align:start position:0% +the oxidation numbers +are all right now we're going to balance + + align:start position:0% +are all right now we're going to balance + + + align:start position:0% +are all right now we're going to balance +so balancing is going to become very + + align:start position:0% +so balancing is going to become very + + + align:start position:0% +so balancing is going to become very +important for doing problems later on + + align:start position:0% +important for doing problems later on + + + align:start position:0% +important for doing problems later on +balancing redo reactions you balance + + align:start position:0% +balancing redo reactions you balance + + + align:start position:0% +balancing redo reactions you balance +differently if you're in acidic + + align:start position:0% +differently if you're in acidic + + + align:start position:0% +differently if you're in acidic +conditions versus basic conditions so + + align:start position:0% +conditions versus basic conditions so + + + align:start position:0% +conditions versus basic conditions so +we're first we're going to do acidic + + align:start position:0% +we're first we're going to do acidic + + + align:start position:0% +we're first we're going to do acidic +conditions and we're going to run + + align:start position:0% +conditions and we're going to run + + + align:start position:0% +conditions and we're going to run +through the steps for doing + + align:start position:0% +through the steps for doing + + + align:start position:0% +through the steps for doing +this first step is we're going to write + + align:start position:0% +this first step is we're going to write + + + align:start position:0% +this first step is we're going to write +two half reactions for for this so we + + align:start position:0% +two half reactions for for this so we + + + align:start position:0% +two half reactions for for this so we +have iron in here and we have chromium + + align:start position:0% +have iron in here and we have chromium + + + align:start position:0% +have iron in here and we have chromium +in here and we're going to separate + + align:start position:0% +in here and we're going to separate + + + align:start position:0% +in here and we're going to separate +those out because we're going to think + + align:start position:0% +those out because we're going to think + + + align:start position:0% +those out because we're going to think +about what iron is doing separately from + + align:start position:0% +about what iron is doing separately from + + + align:start position:0% +about what iron is doing separately from +what the chromium is doing so first um + + align:start position:0% +what the chromium is doing so first um + + + align:start position:0% +what the chromium is doing so first um +let's write out our chromium and think + + align:start position:0% +let's write out our chromium and think + + + align:start position:0% +let's write out our chromium and think +about what is happening to it here and + + align:start position:0% +about what is happening to it here and + + + align:start position:0% +about what is happening to it here and +that is a clicker question + + align:start position:0% + + + + align:start position:0% + +all right 10 more + + align:start position:0% + + + + align:start position:0% + +seconds okay so let's take a look at why + + align:start position:0% +seconds okay so let's take a look at why + + + align:start position:0% +seconds okay so let's take a look at why +two is correct um for one thing you just + + align:start position:0% +two is correct um for one thing you just + + + align:start position:0% +two is correct um for one thing you just +have to remember the definitions um for + + align:start position:0% +have to remember the definitions um for + + + align:start position:0% +have to remember the definitions um for +another you have to recognize what's + + align:start position:0% +another you have to recognize what's + + + align:start position:0% +another you have to recognize what's +happening to the + + align:start position:0% +happening to the + + + align:start position:0% +happening to the +chromium so let's take a look at the + + align:start position:0% +chromium so let's take a look at the + + + align:start position:0% +chromium so let's take a look at the +chromium now so we have oxygen at minus + + align:start position:0% +chromium now so we have oxygen at minus + + + align:start position:0% +chromium now so we have oxygen at minus +2 there's seven of + + align:start position:0% +2 there's seven of + + + align:start position:0% +2 there's seven of +them and the overall charge of the + + align:start position:0% +them and the overall charge of the + + + align:start position:0% +them and the overall charge of the +molecule is minus + + align:start position:0% +molecule is minus + + + align:start position:0% +molecule is minus +two and so what does that mean for the + + align:start position:0% +two and so what does that mean for the + + + align:start position:0% +two and so what does that mean for the +oxidation number of this + + align:start position:0% +oxidation number of this + + + align:start position:0% +oxidation number of this +chromium it's going to be plus 6 is + + align:start position:0% +chromium it's going to be plus 6 is + + + align:start position:0% +chromium it's going to be plus 6 is +we're going to have 12 - 14 = + + align:start position:0% +we're going to have 12 - 14 = + + + align:start position:0% +we're going to have 12 - 14 = +-2 so we're going from plus 6 over here + + align:start position:0% +-2 so we're going from plus 6 over here + + + align:start position:0% +-2 so we're going from plus 6 over here +to+ three here so so is that an + + align:start position:0% +to+ three here so so is that an + + + align:start position:0% +to+ three here so so is that an +oxidation or + + align:start position:0% +oxidation or + + + align:start position:0% +oxidation or +reduction so that's the + + align:start position:0% +reduction so that's the + + + align:start position:0% +reduction so that's the +reduction so I kind of like this unit + + align:start position:0% +reduction so I kind of like this unit + + + align:start position:0% +reduction so I kind of like this unit +coming after acids and bases because a + + align:start position:0% +coming after acids and bases because a + + + align:start position:0% +coming after acids and bases because a +lot of those problems I think make + + align:start position:0% +lot of those problems I think make + + + align:start position:0% +lot of those problems I think make +people's brains hurt a little bit and + + align:start position:0% +people's brains hurt a little bit and + + + align:start position:0% +people's brains hurt a little bit and +you get here and it's like basic math so + + align:start position:0% +you get here and it's like basic math so + + + align:start position:0% +you get here and it's like basic math so +it's kind of exciting all right so the + + align:start position:0% +it's kind of exciting all right so the + + + align:start position:0% +it's kind of exciting all right so the +iron is even simpler we're going from + + align:start position:0% +iron is even simpler we're going from + + + align:start position:0% +iron is even simpler we're going from +plus two to plus3 so that's an oxidation + + align:start position:0% +plus two to plus3 so that's an oxidation + + + align:start position:0% +plus two to plus3 so that's an oxidation +so one thing is being reduced the other + + align:start position:0% +so one thing is being reduced the other + + + align:start position:0% +so one thing is being reduced the other +thing is is being oxidized that's what + + align:start position:0% +thing is is being oxidized that's what + + + align:start position:0% +thing is is being oxidized that's what +makes it a redo + + align:start position:0% +makes it a redo + + + align:start position:0% +makes it a redo +reaction all right so we know what's + + align:start position:0% +reaction all right so we know what's + + + align:start position:0% +reaction all right so we know what's +happening in terms of what's being + + align:start position:0% +happening in terms of what's being + + + align:start position:0% +happening in terms of what's being +oxidized what's being reduced now we' + + align:start position:0% +oxidized what's being reduced now we' + + + align:start position:0% +oxidized what's being reduced now we' +and we've broken these into two half + + align:start position:0% +and we've broken these into two half + + + align:start position:0% +and we've broken these into two half +reactions now we need to + + align:start position:0% +reactions now we need to + + + align:start position:0% +reactions now we need to +balance all right so the first thing + + align:start position:0% +balance all right so the first thing + + + align:start position:0% +balance all right so the first thing +we're going to do is we're going to + + align:start position:0% +we're going to do is we're going to + + + align:start position:0% +we're going to do is we're going to +balance our elements that are not oxygen + + align:start position:0% +balance our elements that are not oxygen + + + align:start position:0% +balance our elements that are not oxygen +and hydrogen so we're going to balance + + align:start position:0% +and hydrogen so we're going to balance + + + align:start position:0% +and hydrogen so we're going to balance +chromium and we're going to balance our + + align:start position:0% +chromium and we're going to balance our + + + align:start position:0% +chromium and we're going to balance our +iron what do we need to add to this top + + align:start position:0% +iron what do we need to add to this top + + + align:start position:0% +iron what do we need to add to this top +to balance + + align:start position:0% +to balance + + + align:start position:0% +to balance +chromium we need to add a + + align:start position:0% +chromium we need to add a + + + align:start position:0% +chromium we need to add a +two and we don't need to do anything to + + align:start position:0% +two and we don't need to do anything to + + + align:start position:0% +two and we don't need to do anything to +our iron we have one iron on one side + + align:start position:0% +our iron we have one iron on one side + + + align:start position:0% +our iron we have one iron on one side +one iron on the other side all right so + + align:start position:0% +one iron on the other side all right so + + + align:start position:0% +one iron on the other side all right so +all you need to do is insert the + + align:start position:0% +all you need to do is insert the + + + align:start position:0% +all you need to do is insert the +two Next Step we're going to add water + + align:start position:0% +two Next Step we're going to add water + + + align:start position:0% +two Next Step we're going to add water +to balance + + align:start position:0% +to balance + + + align:start position:0% +to balance +oxygen so how much water do we need to + + align:start position:0% +oxygen so how much water do we need to + + + align:start position:0% +oxygen so how much water do we need to +add to the top reaction to balance the + + align:start position:0% +add to the top reaction to balance the + + + align:start position:0% +add to the top reaction to balance the +oxygen + + align:start position:0% + + + + align:start position:0% + +so so here we're going to add seven + + align:start position:0% +so so here we're going to add seven + + + align:start position:0% +so so here we're going to add seven +Waters to balance the oxygen and again + + align:start position:0% +Waters to balance the oxygen and again + + + align:start position:0% +Waters to balance the oxygen and again +we have nothing to do down + + align:start position:0% +we have nothing to do down + + + align:start position:0% +we have nothing to do down +there all right so let's keep + + align:start position:0% +there all right so let's keep + + + align:start position:0% +there all right so let's keep +going next we want to balance the + + align:start position:0% +going next we want to balance the + + + align:start position:0% +going next we want to balance the +hydrogen we just added those Waters um + + align:start position:0% +hydrogen we just added those Waters um + + + align:start position:0% +hydrogen we just added those Waters um +and so now we have to balance hydrogen + + align:start position:0% +and so now we have to balance hydrogen + + + align:start position:0% +and so now we have to balance hydrogen +so we're going to balance the hydrogen + + align:start position:0% +so we're going to balance the hydrogen + + + align:start position:0% +so we're going to balance the hydrogen +by adding + + align:start position:0% +by adding + + + align:start position:0% +by adding +H+ some books have you Balan the + + align:start position:0% +H+ some books have you Balan the + + + align:start position:0% +H+ some books have you Balan the +hydrogen by adding a more correct + + align:start position:0% +hydrogen by adding a more correct + + + align:start position:0% +hydrogen by adding a more correct +species which is hydronium ion but when + + align:start position:0% +species which is hydronium ion but when + + + align:start position:0% +species which is hydronium ion but when +you do that you screw up your oxygens + + align:start position:0% +you do that you screw up your oxygens + + + align:start position:0% +you do that you screw up your oxygens +that you just balanced so that is + + align:start position:0% +that you just balanced so that is + + + align:start position:0% +that you just balanced so that is +infinitely harder to balance equations + + align:start position:0% +infinitely harder to balance equations + + + align:start position:0% +infinitely harder to balance equations +that way so I say let's not do that um + + align:start position:0% +that way so I say let's not do that um + + + align:start position:0% +that way so I say let's not do that um +so let's just use + + align:start position:0% +so let's just use + + + align:start position:0% +so let's just use +H+ so how many H+ do we need to add over + + align:start position:0% +H+ so how many H+ do we need to add over + + + align:start position:0% +H+ so how many H+ do we need to add over +here to balance the + + align:start position:0% +here to balance the + + + align:start position:0% +here to balance the +hydrogen 14 we've added 14 and again we + + align:start position:0% +hydrogen 14 we've added 14 and again we + + + align:start position:0% +hydrogen 14 we've added 14 and again we +don't have to do anything to the bottom + + align:start position:0% +don't have to do anything to the bottom + + + align:start position:0% +don't have to do anything to the bottom +um + + align:start position:0% +um + + + align:start position:0% +um +expression next we are going to balance + + align:start position:0% +expression next we are going to balance + + + align:start position:0% +expression next we are going to balance +the charge by inserting electrons so + + align:start position:0% +the charge by inserting electrons so + + + align:start position:0% +the charge by inserting electrons so +over here we have 14 - 2 + 12 and over + + align:start position:0% +over here we have 14 - 2 + 12 and over + + + align:start position:0% +over here we have 14 - 2 + 12 and over +here we have plus 6 so how many + + align:start position:0% +here we have plus 6 so how many + + + align:start position:0% +here we have plus 6 so how many +electrons are going are we going to need + + align:start position:0% +electrons are going are we going to need + + + align:start position:0% +electrons are going are we going to need +to + + align:start position:0% +to + + + align:start position:0% +to +add going to need to add six so we've + + align:start position:0% +add going to need to add six so we've + + + align:start position:0% +add going to need to add six so we've +added six over here so they have a + + align:start position:0% +added six over here so they have a + + + align:start position:0% +added six over here so they have a +negative charge so now we should be + + align:start position:0% +negative charge so now we should be + + + align:start position:0% +negative charge so now we should be +balanced on both sides and now we + + align:start position:0% +balanced on both sides and now we + + + align:start position:0% +balanced on both sides and now we +finally get to do something with a + + align:start position:0% +finally get to do something with a + + + align:start position:0% +finally get to do something with a +bottom expression and we can add an + + align:start position:0% +bottom expression and we can add an + + + align:start position:0% +bottom expression and we can add an +electron over here to balance the charge + + align:start position:0% +electron over here to balance the charge + + + align:start position:0% +electron over here to balance the charge +so plus two here plus two net on the + + align:start position:0% +so plus two here plus two net on the + + + align:start position:0% +so plus two here plus two net on the +other + + align:start position:0% +other + + + align:start position:0% +other +side all + + align:start position:0% + + + + align:start position:0% + +right now we want to + + align:start position:0% +right now we want to + + + align:start position:0% +right now we want to +multiply so that the electrons are going + + align:start position:0% +multiply so that the electrons are going + + + align:start position:0% +multiply so that the electrons are going +to + + align:start position:0% +to + + + align:start position:0% +to +cancel because this is an overall + + align:start position:0% +cancel because this is an overall + + + align:start position:0% +cancel because this is an overall +oxidation reduction reaction and our + + align:start position:0% +oxidation reduction reaction and our + + + align:start position:0% +oxidation reduction reaction and our +electrons should cancel + + align:start position:0% +electrons should cancel + + + align:start position:0% +electrons should cancel +so what do we need to multiply the + + align:start position:0% +so what do we need to multiply the + + + align:start position:0% +so what do we need to multiply the +bottom equation by + + align:start position:0% +bottom equation by + + + align:start position:0% +bottom equation by +six and there we go six here six here + + align:start position:0% +six and there we go six here six here + + + align:start position:0% +six and there we go six here six here +and six here now this is one of the + + align:start position:0% +and six here now this is one of the + + + align:start position:0% +and six here now this is one of the +places that people often in exams um + + align:start position:0% +places that people often in exams um + + + align:start position:0% +places that people often in exams um +make a mistake where they write six and + + align:start position:0% +make a mistake where they write six and + + + align:start position:0% +make a mistake where they write six and +then put um parentheses around it + + align:start position:0% +then put um parentheses around it + + + align:start position:0% +then put um parentheses around it +indicating that you're multiplying the + + align:start position:0% +indicating that you're multiplying the + + + align:start position:0% +indicating that you're multiplying the +whole thing by six which is fine but + + align:start position:0% +whole thing by six which is fine but + + + align:start position:0% +whole thing by six which is fine but +then they forget to actually carry that + + align:start position:0% +then they forget to actually carry that + + + align:start position:0% +then they forget to actually carry that +out on the next step so so when you + + align:start position:0% +out on the next step so so when you + + + align:start position:0% +out on the next step so so when you +multiply make sure that you continue um + + align:start position:0% +multiply make sure that you continue um + + + align:start position:0% +multiply make sure that you continue um +to if sometimes it's better just to + + align:start position:0% +to if sometimes it's better just to + + + align:start position:0% +to if sometimes it's better just to +write it all out because otherwise it's + + align:start position:0% +write it all out because otherwise it's + + + align:start position:0% +write it all out because otherwise it's +really easy to forget um and not + + align:start position:0% +really easy to forget um and not + + + align:start position:0% +really easy to forget um and not +multiply and then things won't make + + align:start position:0% +multiply and then things won't make + + + align:start position:0% +multiply and then things won't make +sense at the end all right so now we can + + align:start position:0% +sense at the end all right so now we can + + + align:start position:0% +sense at the end all right so now we can +add the half reactions and make the + + align:start position:0% +add the half reactions and make the + + + align:start position:0% +add the half reactions and make the +appropriate + + align:start position:0% +appropriate + + + align:start position:0% +appropriate +cancellations so we've now added it all + + align:start position:0% +cancellations so we've now added it all + + + align:start position:0% +cancellations so we've now added it all +together six electrons 14 H+ we have our + + align:start position:0% +together six electrons 14 H+ we have our + + + align:start position:0% +together six electrons 14 H+ we have our +chromium oxide compound we have now our + + align:start position:0% +chromium oxide compound we have now our + + + align:start position:0% +chromium oxide compound we have now our +six iron plus tws our two chromium plus + + align:start position:0% +six iron plus tws our two chromium plus + + + align:start position:0% +six iron plus tws our two chromium plus +3es our seven Waters our six iron plus + + align:start position:0% +3es our seven Waters our six iron plus + + + align:start position:0% +3es our seven Waters our six iron plus +3es and our six electrons and if we did + + align:start position:0% +3es and our six electrons and if we did + + + align:start position:0% +3es and our six electrons and if we did +everything right then the electrons um + + align:start position:0% +everything right then the electrons um + + + align:start position:0% +everything right then the electrons um +should cancel and we can double check + + align:start position:0% +should cancel and we can double check + + + align:start position:0% +should cancel and we can double check +it's always a good idea to double check + + align:start position:0% +it's always a good idea to double check + + + align:start position:0% +it's always a good idea to double check +that it's balanced so we have 14 H's + + align:start position:0% +that it's balanced so we have 14 H's + + + align:start position:0% +that it's balanced so we have 14 H's +here 14 H's there chromium 2 two oxygen + + align:start position:0% +here 14 H's there chromium 2 two oxygen + + + align:start position:0% +here 14 H's there chromium 2 two oxygen +7 7 iron 6 six this can catch a mistake + + align:start position:0% +7 7 iron 6 six this can catch a mistake + + + align:start position:0% +7 7 iron 6 six this can catch a mistake +that you might have made and then check + + align:start position:0% +that you might have made and then check + + + align:start position:0% +that you might have made and then check +the charge + 14 - 2 + 12 on one side + + align:start position:0% +the charge + 14 - 2 + 12 on one side + + + align:start position:0% +the charge + 14 - 2 + 12 on one side +plus um 6 + 18 so 24 on both + + align:start position:0% +plus um 6 + 18 so 24 on both + + + align:start position:0% +plus um 6 + 18 so 24 on both +sides it's pretty good right that's + + align:start position:0% +sides it's pretty good right that's + + + align:start position:0% +sides it's pretty good right that's +pretty simple so balancing that's in + + align:start position:0% +pretty simple so balancing that's in + + + align:start position:0% +pretty simple so balancing that's in +acidic solution we know it's an acidic + + align:start position:0% +acidic solution we know it's an acidic + + + align:start position:0% +acidic solution we know it's an acidic +because we have 14 H+ that feels quite + + align:start position:0% +because we have 14 H+ that feels quite + + + align:start position:0% +because we have 14 H+ that feels quite +acidic what do you do for basic solution + + align:start position:0% +acidic what do you do for basic solution + + + align:start position:0% +acidic what do you do for basic solution +now so for a basic solution what I + + align:start position:0% +now so for a basic solution what I + + + align:start position:0% +now so for a basic solution what I +recommend is just do the exact same + + align:start position:0% +recommend is just do the exact same + + + align:start position:0% +recommend is just do the exact same +thing that you did for your acidic + + align:start position:0% +thing that you did for your acidic + + + align:start position:0% +thing that you did for your acidic +solution and here again was the answer + + align:start position:0% +solution and here again was the answer + + + align:start position:0% +solution and here again was the answer +that we have and then quote neutralize + + align:start position:0% +that we have and then quote neutralize + + + align:start position:0% +that we have and then quote neutralize +um the acid um and make it basic adjust + + align:start position:0% +um the acid um and make it basic adjust + + + align:start position:0% +um the acid um and make it basic adjust +your pH by adding oh minus or hydroxide + + align:start position:0% +your pH by adding oh minus or hydroxide + + + align:start position:0% +your pH by adding oh minus or hydroxide +ion concentration to each side so if we + + align:start position:0% +ion concentration to each side so if we + + + align:start position:0% +ion concentration to each side so if we +do that now we're going to add 14 o o + + align:start position:0% +do that now we're going to add 14 o o + + + align:start position:0% +do that now we're going to add 14 o o +minus to this side and 14 oh minus to + + align:start position:0% +minus to this side and 14 oh minus to + + + align:start position:0% +minus to this side and 14 oh minus to +that side now 14 oh minus us+ 14 H+ are + + align:start position:0% +that side now 14 oh minus us+ 14 H+ are + + + align:start position:0% +that side now 14 oh minus us+ 14 H+ are +going to give us 14 water molecules over + + align:start position:0% +going to give us 14 water molecules over + + + align:start position:0% +going to give us 14 water molecules over +here and on this side we still have 14 o + + align:start position:0% +here and on this side we still have 14 o + + + align:start position:0% +here and on this side we still have 14 o +now we have this is not simplified + + align:start position:0% +now we have this is not simplified + + + align:start position:0% +now we have this is not simplified +because we have 14 waters on one side + + align:start position:0% +because we have 14 waters on one side + + + align:start position:0% +because we have 14 waters on one side +and seven on the other side so we can + + align:start position:0% +and seven on the other side so we can + + + align:start position:0% +and seven on the other side so we can +take that cancel out set these seven and + + align:start position:0% +take that cancel out set these seven and + + + align:start position:0% +take that cancel out set these seven and +we have seven left over here so we have + + align:start position:0% +we have seven left over here so we have + + + align:start position:0% +we have seven left over here so we have +seven Waters now on one side and 14 + + align:start position:0% +seven Waters now on one side and 14 + + + align:start position:0% +seven Waters now on one side and 14 +hydroxides on the other so if we look at + + align:start position:0% +hydroxides on the other so if we look at + + + align:start position:0% +hydroxides on the other so if we look at +both of these expressions in acidic + + align:start position:0% +both of these expressions in acidic + + + align:start position:0% +both of these expressions in acidic +solution and in basic solution here in + + align:start position:0% +solution and in basic solution here in + + + align:start position:0% +solution and in basic solution here in +acidic solution we have 14 H+ on one + + align:start position:0% +acidic solution we have 14 H+ on one + + + align:start position:0% +acidic solution we have 14 H+ on one +side and seven waters on the other in + + align:start position:0% +side and seven waters on the other in + + + align:start position:0% +side and seven waters on the other in +basic we have seven waters on this side + + align:start position:0% +basic we have seven waters on this side + + + align:start position:0% +basic we have seven waters on this side +and 14 o minus on this side everything + + align:start position:0% +and 14 o minus on this side everything + + + align:start position:0% +and 14 o minus on this side everything +else should be the same and they should + + align:start position:0% +else should be the same and they should + + + align:start position:0% +else should be the same and they should +all add up all right so there we go that + + align:start position:0% +all add up all right so there we go that + + + align:start position:0% +all add up all right so there we go that +is balancing oxidation reductions it + + align:start position:0% +is balancing oxidation reductions it + + + align:start position:0% +is balancing oxidation reductions it +seems really straightforward um but it's + + align:start position:0% +seems really straightforward um but it's + + + align:start position:0% +seems really straightforward um but it's +very important we'll see next week that + + align:start position:0% +very important we'll see next week that + + + align:start position:0% +very important we'll see next week that +we need use this information to be able + + align:start position:0% +we need use this information to be able + + + align:start position:0% +we need use this information to be able +to do problems all right so end of 14 + + align:start position:0% +to do problems all right so end of 14 + + + align:start position:0% +to do problems all right so end of 14 +now to + + align:start position:0% + + + + align:start position:0% + +electrochemistry so today's + + align:start position:0% +electrochemistry so today's + + + align:start position:0% +electrochemistry so today's +handout so we've been talking about + + align:start position:0% +handout so we've been talking about + + + align:start position:0% +handout so we've been talking about +oxidation reduction we're continuing + + align:start position:0% +oxidation reduction we're continuing + + + align:start position:0% +oxidation reduction we're continuing +talking about oxidation reduction I just + + align:start position:0% +talking about oxidation reduction I just + + + align:start position:0% +talking about oxidation reduction I just +want to remind you how really important + + align:start position:0% +want to remind you how really important + + + align:start position:0% +want to remind you how really important +oxidation reduction reactions are so + + align:start position:0% +oxidation reduction reactions are so + + + align:start position:0% +oxidation reduction reactions are so +we've talked about photosynthesis in + + align:start position:0% +we've talked about photosynthesis in + + + align:start position:0% +we've talked about photosynthesis in +this class we've talked about fuel cells + + align:start position:0% +this class we've talked about fuel cells + + + align:start position:0% +this class we've talked about fuel cells +all of these reactions that make energy + + align:start position:0% +all of these reactions that make energy + + + align:start position:0% +all of these reactions that make energy +in involve oxidation reduction loss of + + align:start position:0% +in involve oxidation reduction loss of + + + align:start position:0% +in involve oxidation reduction loss of +electrons gain of electrons basically + + align:start position:0% +electrons gain of electrons basically + + + align:start position:0% +electrons gain of electrons basically +the human body is a big battery we have + + align:start position:0% +the human body is a big battery we have + + + align:start position:0% +the human body is a big battery we have +lots of oxidation reduction reactions + + align:start position:0% +lots of oxidation reduction reactions + + + align:start position:0% +lots of oxidation reduction reactions +going on inside of us this is how we + + align:start position:0% +going on inside of us this is how we + + + align:start position:0% +going on inside of us this is how we +live this is how we make energy this is + + align:start position:0% +live this is how we make energy this is + + + align:start position:0% +live this is how we make energy this is +how we + + align:start position:0% +how we + + + align:start position:0% +how we +survive all right so electrochemistry is + + align:start position:0% +survive all right so electrochemistry is + + + align:start position:0% +survive all right so electrochemistry is +the study of Redux reactions usually um + + align:start position:0% +the study of Redux reactions usually um + + + align:start position:0% +the study of Redux reactions usually um +thinking about how they occur at an + + align:start position:0% +thinking about how they occur at an + + + align:start position:0% +thinking about how they occur at an +electrode so there are two types of + + align:start position:0% +electrode so there are two types of + + + align:start position:0% +electrode so there are two types of +reactions that you will be considering + + align:start position:0% +reactions that you will be considering + + + align:start position:0% +reactions that you will be considering +um you might be considering um a + + align:start position:0% +um you might be considering um a + + + align:start position:0% +um you might be considering um a +reaction that generates an electric + + align:start position:0% +reaction that generates an electric + + + align:start position:0% +reaction that generates an electric +current electron flow or electricity + + align:start position:0% +current electron flow or electricity + + + align:start position:0% +current electron flow or electricity +from a spontaneous reaction and you + + align:start position:0% +from a spontaneous reaction and you + + + align:start position:0% +from a spontaneous reaction and you +might consider one where you need to + + align:start position:0% +might consider one where you need to + + + align:start position:0% +might consider one where you need to +drive a reaction that is nonspontaneous + + align:start position:0% +drive a reaction that is nonspontaneous + + + align:start position:0% +drive a reaction that is nonspontaneous +using an electric current so a + + align:start position:0% +using an electric current so a + + + align:start position:0% +using an electric current so a +spontaneous reaction Delta G is what + + align:start position:0% +spontaneous reaction Delta G is what + + + align:start position:0% +spontaneous reaction Delta G is what +positive or negative negative right so + + align:start position:0% +positive or negative negative right so + + + align:start position:0% +positive or negative negative right so +spontaneous reaction Delta G is negative + + align:start position:0% +spontaneous reaction Delta G is negative + + + align:start position:0% +spontaneous reaction Delta G is negative +it's less than zero a nonspontaneous + + align:start position:0% +it's less than zero a nonspontaneous + + + align:start position:0% +it's less than zero a nonspontaneous +reaction is positive just a little + + align:start position:0% +reaction is positive just a little + + + align:start position:0% +reaction is positive just a little +review there uh for exam + + align:start position:0% +review there uh for exam + + + align:start position:0% +review there uh for exam +three all right so electrochemistry + + align:start position:0% +three all right so electrochemistry + + + align:start position:0% +three all right so electrochemistry +study of these Redux reactions + + align:start position:0% +study of these Redux reactions + + + align:start position:0% +study of these Redux reactions +electrochemical cells are devices where + + align:start position:0% +electrochemical cells are devices where + + + align:start position:0% +electrochemical cells are devices where +you generate electrons and they flow + + align:start position:0% +you generate electrons and they flow + + + align:start position:0% +you generate electrons and they flow +through the cell um and so you have the + + align:start position:0% +through the cell um and so you have the + + + align:start position:0% +through the cell um and so you have the +flow of electrons through a circuit and + + align:start position:0% +flow of electrons through a circuit and + + + align:start position:0% +flow of electrons through a circuit and +again that can be generated by a + + align:start position:0% +again that can be generated by a + + + align:start position:0% +again that can be generated by a +spontaneous reaction and if it is + + align:start position:0% +spontaneous reaction and if it is + + + align:start position:0% +spontaneous reaction and if it is +generated by a spontaneous reaction + + align:start position:0% +generated by a spontaneous reaction + + + align:start position:0% +generated by a spontaneous reaction +that's called a galvanic cell or you can + + align:start position:0% +that's called a galvanic cell or you can + + + align:start position:0% +that's called a galvanic cell or you can +use an electric current to force a + + align:start position:0% +use an electric current to force a + + + align:start position:0% +use an electric current to force a +non-spontaneous reaction to go and + + align:start position:0% +non-spontaneous reaction to go and + + + align:start position:0% +non-spontaneous reaction to go and +that's called an electrolytic cell and + + align:start position:0% +that's called an electrolytic cell and + + + align:start position:0% +that's called an electrolytic cell and +it's important to remember those + + align:start position:0% +it's important to remember those + + + align:start position:0% +it's important to remember those +definitions because a lot of problems + + align:start position:0% +definitions because a lot of problems + + + align:start position:0% +definitions because a lot of problems +tell you oh in this electrolytic cell + + align:start position:0% +tell you oh in this electrolytic cell + + + align:start position:0% +tell you oh in this electrolytic cell +and without that's telling you key + + align:start position:0% +and without that's telling you key + + + align:start position:0% +and without that's telling you key +information about what's going on in + + align:start position:0% +information about what's going on in + + + align:start position:0% +information about what's going on in +that problem so so if you uh don't have + + align:start position:0% +that problem so so if you uh don't have + + + align:start position:0% +that problem so so if you uh don't have +these uh committed to Memories you will + + align:start position:0% +these uh committed to Memories you will + + + align:start position:0% +these uh committed to Memories you will +uh find yourself in trouble but it's not + + align:start position:0% +uh find yourself in trouble but it's not + + + align:start position:0% +uh find yourself in trouble but it's not +too bad it's just two terms all right so + + align:start position:0% +too bad it's just two terms all right so + + + align:start position:0% +too bad it's just two terms all right so +a battery then so I have a uh a battery + + align:start position:0% +a battery then so I have a uh a battery + + + align:start position:0% +a battery then so I have a uh a battery +here a battery is a collection of + + align:start position:0% +here a battery is a collection of + + + align:start position:0% +here a battery is a collection of +galvanic cells um and it's going to give + + align:start position:0% +galvanic cells um and it's going to give + + + align:start position:0% +galvanic cells um and it's going to give +us it's going to use spontaneous + + align:start position:0% +us it's going to use spontaneous + + + align:start position:0% +us it's going to use spontaneous +reactions to give us an El electric + + align:start position:0% +reactions to give us an El electric + + + align:start position:0% +reactions to give us an El electric +current all right and again electrodes + + align:start position:0% +current all right and again electrodes + + + align:start position:0% +current all right and again electrodes +the definition for those they're just + + align:start position:0% +the definition for those they're just + + + align:start position:0% +the definition for those they're just +the conductors through which the + + align:start position:0% +the conductors through which the + + + align:start position:0% +the conductors through which the +electrons travel and they're two types + + align:start position:0% +electrons travel and they're two types + + + align:start position:0% +electrons travel and they're two types +let's quiet down again I hear the noise + + align:start position:0% +let's quiet down again I hear the noise + + + align:start position:0% +let's quiet down again I hear the noise +uh two types of electrodes we have + + align:start position:0% +uh two types of electrodes we have + + + align:start position:0% +uh two types of electrodes we have +anodes and + + align:start position:0% +anodes and + + + align:start position:0% +anodes and +cathodes all right so let's look at an + + align:start position:0% +cathodes all right so let's look at an + + + align:start position:0% +cathodes all right so let's look at an +electrochemical + + align:start position:0% +electrochemical + + + align:start position:0% +electrochemical +cell and consider again the anodes and + + align:start position:0% +cell and consider again the anodes and + + + align:start position:0% +cell and consider again the anodes and +the cathodes so this is my beautiful + + align:start position:0% +the cathodes so this is my beautiful + + + align:start position:0% +the cathodes so this is my beautiful +depiction of an El electrochemical cell + + align:start position:0% +depiction of an El electrochemical cell + + + align:start position:0% +depiction of an El electrochemical cell +this might be a better depiction of what + + align:start position:0% +this might be a better depiction of what + + + align:start position:0% +this might be a better depiction of what +it looks like but I think mine is not + + align:start position:0% +it looks like but I think mine is not + + + align:start position:0% +it looks like but I think mine is not +bad um just to help you out that's + + align:start position:0% +bad um just to help you out that's + + + align:start position:0% +bad um just to help you out that's +supposed to be a beaker that has fluid + + align:start position:0% +supposed to be a beaker that has fluid + + + align:start position:0% +supposed to be a beaker that has fluid +in it + + align:start position:0% +in it + + + align:start position:0% +in it +um this is also a beaker that has fluid + + align:start position:0% +um this is also a beaker that has fluid + + + align:start position:0% +um this is also a beaker that has fluid +in it and this is my uh electrode that + + align:start position:0% +in it and this is my uh electrode that + + + align:start position:0% +in it and this is my uh electrode that +is an anode in this case there is the uh + + align:start position:0% +is an anode in this case there is the uh + + + align:start position:0% +is an anode in this case there is the uh +anode there or the electrode there um + + align:start position:0% +anode there or the electrode there um + + + align:start position:0% +anode there or the electrode there um +here's another one that's the cathode + + align:start position:0% +here's another one that's the cathode + + + align:start position:0% +here's another one that's the cathode +another type of electrode it's over here + + align:start position:0% +another type of electrode it's over here + + + align:start position:0% +another type of electrode it's over here +this is my salt bridge the salt bridge + + align:start position:0% +this is my salt bridge the salt bridge + + + align:start position:0% +this is my salt bridge the salt bridge +here is this plastic tube and here I + + align:start position:0% +here is this plastic tube and here I + + + align:start position:0% +here is this plastic tube and here I +have a wire connecting my electrodes + + align:start position:0% +have a wire connecting my electrodes + + + align:start position:0% +have a wire connecting my electrodes +here you can't really see the wire but + + align:start position:0% +here you can't really see the wire but + + + align:start position:0% +here you can't really see the wire but +in both cases it goes through some kind + + align:start position:0% +in both cases it goes through some kind + + + align:start position:0% +in both cases it goes through some kind +of voltmeter that measures the electric + + align:start position:0% +of voltmeter that measures the electric + + + align:start position:0% +of voltmeter that measures the electric +electric current + + align:start position:0% +electric current + + + align:start position:0% +electric current +all right so now we'll get rid of this + + align:start position:0% +all right so now we'll get rid of this + + + align:start position:0% +all right so now we'll get rid of this +better picture but you can think about + + align:start position:0% +better picture but you can think about + + + align:start position:0% +better picture but you can think about +this picture as that picture if that + + align:start position:0% +this picture as that picture if that + + + align:start position:0% +this picture as that picture if that +helps and I always like to joke that you + + align:start position:0% +helps and I always like to joke that you + + + align:start position:0% +helps and I always like to joke that you +know you think you have it bad here at + + align:start position:0% +know you think you have it bad here at + + + align:start position:0% +know you think you have it bad here at +MIT in the old days um before you could + + align:start position:0% +MIT in the old days um before you could + + + align:start position:0% +MIT in the old days um before you could +do your problem set at 2 o'clock in the + + align:start position:0% +do your problem set at 2 o'clock in the + + + align:start position:0% +do your problem set at 2 o'clock in the +morning you had to build your own + + align:start position:0% +morning you had to build your own + + + align:start position:0% +morning you had to build your own +batteries um to be able to do it all + + align:start position:0% +batteries um to be able to do it all + + + align:start position:0% +batteries um to be able to do it all +right so + + align:start position:0% +right so + + + align:start position:0% +right so +anode electrons are produced from + + align:start position:0% +anode electrons are produced from + + + align:start position:0% +anode electrons are produced from +oxidation at the anode so the electrons + + align:start position:0% +oxidation at the anode so the electrons + + + align:start position:0% +oxidation at the anode so the electrons +produced here flow out of the + + align:start position:0% +produced here flow out of the + + + align:start position:0% +produced here flow out of the +cell and in this particular type of + + align:start position:0% +cell and in this particular type of + + + align:start position:0% +cell and in this particular type of +electrochemical cell zinc solid is + + align:start position:0% +electrochemical cell zinc solid is + + + align:start position:0% +electrochemical cell zinc solid is +oxidized to zinc plus two so if we look + + align:start position:0% +oxidized to zinc plus two so if we look + + + align:start position:0% +oxidized to zinc plus two so if we look +at this over here this is my little + + align:start position:0% +at this over here this is my little + + + align:start position:0% +at this over here this is my little +beautiful uh depiction of the blow up of + + align:start position:0% +beautiful uh depiction of the blow up of + + + align:start position:0% +beautiful uh depiction of the blow up of +the of the electrode we have our zinc + + align:start position:0% +the of the electrode we have our zinc + + + align:start position:0% +the of the electrode we have our zinc +solid here and we have zinc plus two in + + align:start position:0% +solid here and we have zinc plus two in + + + align:start position:0% +solid here and we have zinc plus two in +aquous solution so when the electrons uh + + align:start position:0% +aquous solution so when the electrons uh + + + align:start position:0% +aquous solution so when the electrons uh +leave the zinc solid so that the zinc + + align:start position:0% +leave the zinc solid so that the zinc + + + align:start position:0% +leave the zinc solid so that the zinc +then uh leaves the electrode and goes + + align:start position:0% +then uh leaves the electrode and goes + + + align:start position:0% +then uh leaves the electrode and goes +into solution forming zinc plus two + + align:start position:0% +into solution forming zinc plus two + + + align:start position:0% +into solution forming zinc plus two +those electrons go out so the electrons + + align:start position:0% +those electrons go out so the electrons + + + align:start position:0% +those electrons go out so the electrons +will then go into the cathode and notice + + align:start position:0% +will then go into the cathode and notice + + + align:start position:0% +will then go into the cathode and notice +I had a typo in the handout I find this + + align:start position:0% +I had a typo in the handout I find this + + + align:start position:0% +I had a typo in the handout I find this +kind pretty funny I don't know if it's + + align:start position:0% +kind pretty funny I don't know if it's + + + align:start position:0% +kind pretty funny I don't know if it's +me or spell check right now I wrote + + align:start position:0% +me or spell check right now I wrote + + + align:start position:0% +me or spell check right now I wrote +elections are uh consumed oh man it's + + align:start position:0% +elections are uh consumed oh man it's + + + align:start position:0% +elections are uh consumed oh man it's +been a long week between the national + + align:start position:0% +been a long week between the national + + + align:start position:0% +been a long week between the national +elections and our t-shirt elections um + + align:start position:0% +elections and our t-shirt elections um + + + align:start position:0% +elections and our t-shirt elections um +anyway I didn't mean elections I meant + + align:start position:0% +anyway I didn't mean elections I meant + + + align:start position:0% +anyway I didn't mean elections I meant +electrons + + align:start position:0% +electrons + + + align:start position:0% +electrons +yes of course electrons are consumed by + + align:start position:0% +yes of course electrons are consumed by + + + align:start position:0% +yes of course electrons are consumed by +a reduction + + align:start position:0% +a reduction + + + align:start position:0% +a reduction +reaction of course I noticed that after + + align:start position:0% +reaction of course I noticed that after + + + align:start position:0% +reaction of course I noticed that after +I had printed hundreds of copies okay um + + align:start position:0% +I had printed hundreds of copies okay um + + + align:start position:0% +I had printed hundreds of copies okay um +and this particular reaction here copper + + align:start position:0% +and this particular reaction here copper + + + align:start position:0% +and this particular reaction here copper +plus two is reduced to Copper solid and + + align:start position:0% +plus two is reduced to Copper solid and + + + align:start position:0% +plus two is reduced to Copper solid and +if we look over here we have copper plus + + align:start position:0% +if we look over here we have copper plus + + + align:start position:0% +if we look over here we have copper plus +two in aquous solution when electrons + + align:start position:0% +two in aquous solution when electrons + + + align:start position:0% +two in aquous solution when electrons +two electrons come in those two + + align:start position:0% +two electrons come in those two + + + align:start position:0% +two electrons come in those two +electrons go to the Copper plus two and + + align:start position:0% +electrons go to the Copper plus two and + + + align:start position:0% +electrons go to the Copper plus two and +reduce it to copper solid and the copper + + align:start position:0% +reduce it to copper solid and the copper + + + align:start position:0% +reduce it to copper solid and the copper +solid actually plates on the + + align:start position:0% +solid actually plates on the + + + align:start position:0% +solid actually plates on the +electrode so we can measure the flow we + + align:start position:0% +electrode so we can measure the flow we + + + align:start position:0% +electrode so we can measure the flow we +can have a meter that measures the volts + + align:start position:0% +can have a meter that measures the volts + + + align:start position:0% +can have a meter that measures the volts +or the flow of electrons the electron + + align:start position:0% +or the flow of electrons the electron + + + align:start position:0% +or the flow of electrons the electron +current and also what's that salt bridge + + align:start position:0% +current and also what's that salt bridge + + + align:start position:0% +current and also what's that salt bridge +doing well the salt bridge can help + + align:start position:0% +doing well the salt bridge can help + + + align:start position:0% +doing well the salt bridge can help +maintain the neutrality in the system + + align:start position:0% +maintain the neutrality in the system + + + align:start position:0% +maintain the neutrality in the system +because over here we're generating plus + + align:start position:0% +because over here we're generating plus + + + align:start position:0% +because over here we're generating plus +charge and over here we're losing pris + + align:start position:0% +charge and over here we're losing pris + + + align:start position:0% +charge and over here we're losing pris +charge and so ions can flow through the + + align:start position:0% +charge and so ions can flow through the + + + align:start position:0% +charge and so ions can flow through the +salt bridge and keep the charges more + + align:start position:0% +salt bridge and keep the charges more + + + align:start position:0% +salt bridge and keep the charges more +similar in our two different + + align:start position:0% +similar in our two different + + + align:start position:0% +similar in our two different +beakers all right so I know my pictures + + align:start position:0% +beakers all right so I know my pictures + + + align:start position:0% +beakers all right so I know my pictures +are gorgeous but I have a little + + align:start position:0% +are gorgeous but I have a little + + + align:start position:0% +are gorgeous but I have a little +animation to show you um that um will + + align:start position:0% +animation to show you um that um will + + + align:start position:0% +animation to show you um that um will +also show you what I was talking about + + align:start position:0% +also show you what I was talking about + + + align:start position:0% +also show you what I was talking about +oxidation at the electrode so zinc um + + align:start position:0% +oxidation at the electrode so zinc um + + + align:start position:0% +oxidation at the electrode so zinc um +zinc solid is going to lose electrons + + align:start position:0% +zinc solid is going to lose electrons + + + align:start position:0% +zinc solid is going to lose electrons +and form zinc plus two and let me just + + align:start position:0% +and form zinc plus two and let me just + + + align:start position:0% +and form zinc plus two and let me just +show you that + + align:start position:0% +show you that + + + align:start position:0% +show you that +happening so there are the electrons + + align:start position:0% +happening so there are the electrons + + + align:start position:0% +happening so there are the electrons +going away and here is zinc popping off + + align:start position:0% +going away and here is zinc popping off + + + align:start position:0% +going away and here is zinc popping off +as zinc plus + + align:start position:0% +as zinc plus + + + align:start position:0% +as zinc plus +two and then the zinc plus two is going + + align:start position:0% +two and then the zinc plus two is going + + + align:start position:0% +two and then the zinc plus two is going +to be in solution so there are the + + align:start position:0% +to be in solution so there are the + + + align:start position:0% +to be in solution so there are the +electrons go again and the zinc solid + + align:start position:0% +electrons go again and the zinc solid + + + align:start position:0% +electrons go again and the zinc solid +pops off as zinc plus + + align:start position:0% +pops off as zinc plus + + + align:start position:0% +pops off as zinc plus +two all right so now let's consider + + align:start position:0% +two all right so now let's consider + + + align:start position:0% +two all right so now let's consider +reduction at the cathode so here we have + + align:start position:0% +reduction at the cathode so here we have + + + align:start position:0% +reduction at the cathode so here we have +our copper solid here we have a copper + + align:start position:0% +our copper solid here we have a copper + + + align:start position:0% +our copper solid here we have a copper +plus two and here the electrons are + + align:start position:0% +plus two and here the electrons are + + + align:start position:0% +plus two and here the electrons are +going to come in and um join up with our + + align:start position:0% +going to come in and um join up with our + + + align:start position:0% +going to come in and um join up with our +copper plus two and it's going to plate + + align:start position:0% +copper plus two and it's going to plate + + + align:start position:0% +copper plus two and it's going to plate +on to the + + align:start position:0% + + + + align:start position:0% + +electrode there come the electrons there + + align:start position:0% +electrode there come the electrons there + + + align:start position:0% +electrode there come the electrons there +they come + + align:start position:0% +they come + + + align:start position:0% +they come +again and now we have added solid copper + + align:start position:0% +again and now we have added solid copper + + + align:start position:0% +again and now we have added solid copper +to our electrod and just one more time + + align:start position:0% +to our electrod and just one more time + + + align:start position:0% +to our electrod and just one more time +and I think it's so cool that we can + + align:start position:0% +and I think it's so cool that we can + + + align:start position:0% +and I think it's so cool that we can +just watch those electrons move like + + align:start position:0% +just watch those electrons move like + + + align:start position:0% +just watch those electrons move like +that + + align:start position:0% + + + + align:start position:0% + +okay all right so there's our + + align:start position:0% +okay all right so there's our + + + align:start position:0% +okay all right so there's our +electrochemical cell where we have an + + align:start position:0% +electrochemical cell where we have an + + + align:start position:0% +electrochemical cell where we have an +oxidation and a reduction + + align:start position:0% +oxidation and a reduction + + + align:start position:0% +oxidation and a reduction +reaction um instead of drawing this + + align:start position:0% +reaction um instead of drawing this + + + align:start position:0% +reaction um instead of drawing this +admittedly beautiful picture every time + + align:start position:0% +admittedly beautiful picture every time + + + align:start position:0% +admittedly beautiful picture every time +we can have a shorthand representation + + align:start position:0% +we can have a shorthand representation + + + align:start position:0% +we can have a shorthand representation +for this so we can say um zinc solid and + + align:start position:0% +for this so we can say um zinc solid and + + + align:start position:0% +for this so we can say um zinc solid and +then we have a little line here that + + align:start position:0% +then we have a little line here that + + + align:start position:0% +then we have a little line here that +little line indicates we have a phase + + align:start position:0% +little line indicates we have a phase + + + align:start position:0% +little line indicates we have a phase +boundary so that means we're going from + + align:start position:0% +boundary so that means we're going from + + + align:start position:0% +boundary so that means we're going from +solid to a different phase and in this + + align:start position:0% +solid to a different phase and in this + + + align:start position:0% +solid to a different phase and in this +case we're going to aquous so solid zinc + + align:start position:0% +case we're going to aquous so solid zinc + + + align:start position:0% +case we're going to aquous so solid zinc +to zinc plus 2 + + align:start position:0% +to zinc plus 2 + + + align:start position:0% +to zinc plus 2 +the two lines here indicate the salt + + align:start position:0% +the two lines here indicate the salt + + + align:start position:0% +the two lines here indicate the salt +bridge so this tells us that the + + align:start position:0% +bridge so this tells us that the + + + align:start position:0% +bridge so this tells us that the +reaction on this side is in one Beaker + + align:start position:0% +reaction on this side is in one Beaker + + + align:start position:0% +reaction on this side is in one Beaker +and the reaction on this side is in our + + align:start position:0% +and the reaction on this side is in our + + + align:start position:0% +and the reaction on this side is in our +other Beaker the reaction in the other + + align:start position:0% +other Beaker the reaction in the other + + + align:start position:0% +other Beaker the reaction in the other +side is copper plus two aquous a single + + align:start position:0% +side is copper plus two aquous a single + + + align:start position:0% +side is copper plus two aquous a single +line for phase boundary going to Copper + + align:start position:0% +line for phase boundary going to Copper + + + align:start position:0% +line for phase boundary going to Copper +solid now if we had say two aquous + + align:start position:0% +solid now if we had say two aquous + + + align:start position:0% +solid now if we had say two aquous +species we wouldn't have a phase + + align:start position:0% +species we wouldn't have a phase + + + align:start position:0% +species we wouldn't have a phase +boundary we' just have a comma but if + + align:start position:0% +boundary we' just have a comma but if + + + align:start position:0% +boundary we' just have a comma but if +you have a phase boundary you get the + + align:start position:0% +you have a phase boundary you get the + + + align:start position:0% +you have a phase boundary you get the +line all right so let's uh a click our + + align:start position:0% +line all right so let's uh a click our + + + align:start position:0% +line all right so let's uh a click our +comp I Let's uh consider another cell it + + align:start position:0% +comp I Let's uh consider another cell it + + + align:start position:0% +comp I Let's uh consider another cell it +still has zinc but now it has tin why + + align:start position:0% +still has zinc but now it has tin why + + + align:start position:0% +still has zinc but now it has tin why +don't you uh tell me which reaction is + + align:start position:0% +don't you uh tell me which reaction is + + + align:start position:0% +don't you uh tell me which reaction is +at the anode and which reaction is at + + align:start position:0% +at the anode and which reaction is at + + + align:start position:0% +at the anode and which reaction is at +the + + align:start position:0% + + + + align:start position:0% + +cathode and also which of those is + + align:start position:0% +cathode and also which of those is + + + align:start position:0% +cathode and also which of those is +oxidations and which is reductions + + align:start position:0% + + + + align:start position:0% + +all right we'll just do 10 more + + align:start position:0% + + + + align:start position:0% + +seconds great okay so uh some of these + + align:start position:0% +seconds great okay so uh some of these + + + align:start position:0% +seconds great okay so uh some of these +had parts of it right but there was a + + align:start position:0% +had parts of it right but there was a + + + align:start position:0% +had parts of it right but there was a +mistake we have an ox so that is wrong + + align:start position:0% +mistake we have an ox so that is wrong + + + align:start position:0% +mistake we have an ox so that is wrong +um so you have to pay attention to + + align:start position:0% +um so you have to pay attention to + + + align:start position:0% +um so you have to pay attention to +whether these match and then also that + + align:start position:0% +whether these match and then also that + + + align:start position:0% +whether these match and then also that +the reaction is written consistent with + + align:start position:0% +the reaction is written consistent with + + + align:start position:0% +the reaction is written consistent with +the word so only number two had all the + + align:start position:0% +the word so only number two had all the + + + align:start position:0% +the word so only number two had all the +various different parts right okay so we + + align:start position:0% +various different parts right okay so we + + + align:start position:0% +various different parts right okay so we +can come back here and you can enter so + + align:start position:0% +can come back here and you can enter so + + + align:start position:0% +can come back here and you can enter so +the reaction at the anode was the zinc + + align:start position:0% +the reaction at the anode was the zinc + + + align:start position:0% +the reaction at the anode was the zinc +reaction and that is an oxidation an ox + + align:start position:0% +reaction and that is an oxidation an ox + + + align:start position:0% +reaction and that is an oxidation an ox +the reaction at the cathode is the 10 + + align:start position:0% +the reaction at the cathode is the 10 + + + align:start position:0% +the reaction at the cathode is the 10 +reaction um 10+ 4 two electrons 10 plus + + align:start position:0% +reaction um 10+ 4 two electrons 10 plus + + + align:start position:0% +reaction um 10+ 4 two electrons 10 plus +2 aquous and that's a reduction and + + align:start position:0% +2 aquous and that's a reduction and + + + align:start position:0% +2 aquous and that's a reduction and +while you have uh your clickers out why + + align:start position:0% +while you have uh your clickers out why + + + align:start position:0% +while you have uh your clickers out why +not don't you tell me how you would + + align:start position:0% +not don't you tell me how you would + + + align:start position:0% +not don't you tell me how you would +represent that electrochemical + + align:start position:0% + + + + align:start position:0% + +cell all right let's just do 10 more + + align:start position:0% +cell all right let's just do 10 more + + + align:start position:0% +cell all right let's just do 10 more +seconds + + align:start position:0% + + + + align:start position:0% + +M so right so I mentioned this very + + align:start position:0% +M so right so I mentioned this very + + + align:start position:0% +M so right so I mentioned this very +briefly this was my tricky clicker + + align:start position:0% +briefly this was my tricky clicker + + + align:start position:0% +briefly this was my tricky clicker +question because it's a + + align:start position:0% +question because it's a + + + align:start position:0% +question because it's a +competition so there's no phase + + align:start position:0% +competition so there's no phase + + + align:start position:0% +competition so there's no phase +transition here so you have a + + align:start position:0% +transition here so you have a + + + align:start position:0% +transition here so you have a +comma and the top one a few people put + + align:start position:0% +comma and the top one a few people put + + + align:start position:0% +comma and the top one a few people put +down but it's not it's not uh solid here + + align:start position:0% +down but it's not it's not uh solid here + + + align:start position:0% +down but it's not it's not uh solid here +so that one is is not correct okay so + + align:start position:0% +so that one is is not correct okay so + + + align:start position:0% +so that one is is not correct okay so +here you can write down in your notes + + align:start position:0% +here you can write down in your notes + + + align:start position:0% +here you can write down in your notes +you have the zinc um phase transition + + align:start position:0% +you have the zinc um phase transition + + + align:start position:0% +you have the zinc um phase transition +zinc plus two aquous and then we have + + align:start position:0% +zinc plus two aquous and then we have + + + align:start position:0% +zinc plus two aquous and then we have +our salt bridge zinc plus 4 aquous comma + + align:start position:0% +our salt bridge zinc plus 4 aquous comma + + + align:start position:0% +our salt bridge zinc plus 4 aquous comma +or SN 10 plus 4 comma 10 + 2 and now + + align:start position:0% +or SN 10 plus 4 comma 10 + 2 and now + + + align:start position:0% +or SN 10 plus 4 comma 10 + 2 and now +we're ready for + + align:start position:0% +we're ready for + + + align:start position:0% +we're ready for +winners we'll see if Sam's also ready to + + align:start position:0% +winners we'll see if Sam's also ready to + + + align:start position:0% +winners we'll see if Sam's also ready to +present the + + align:start position:0% + + + + align:start position:0% + +winners all + + align:start position:0% +winners all + + + align:start position:0% +winners all +right we need strategy to defeat Dan's + + align:start position:0% +right we need strategy to defeat Dan's + + + align:start position:0% +right we need strategy to defeat Dan's +recitation but we know what t-shirt + + align:start position:0% +recitation but we know what t-shirt + + + align:start position:0% +recitation but we know what t-shirt +we're playing for now all right have a + + align:start position:0% +we're playing for now all right have a + + + align:start position:0% +we're playing for now all right have a +great weekend + + align:start position:0% + + + + align:start position:0% + +everybody all right let's just uh take + + align:start position:0% +everybody all right let's just uh take + + + align:start position:0% +everybody all right let's just uh take +10 more seconds + + align:start position:0% + + + + align:start position:0% + +all right does someone want to tell me + + align:start position:0% +all right does someone want to tell me + + + align:start position:0% +all right does someone want to tell me +how they got the right + + align:start position:0% + + + + align:start position:0% + +answer + + align:start position:0% + + + + align:start position:0% + +yep you know that your hydrogen will + + align:start position:0% +yep you know that your hydrogen will + + + align:start position:0% +yep you know that your hydrogen will +have a plus one charge and your oxygen + + align:start position:0% +have a plus one charge and your oxygen + + + align:start position:0% +have a plus one charge and your oxygen +will have a minus two charge because + + align:start position:0% +will have a minus two charge because + + + align:start position:0% +will have a minus two charge because +it's not a peroxide and you know your SU + + align:start position:0% +it's not a peroxide and you know your SU + + + align:start position:0% +it's not a peroxide and you know your SU +is going to be neutral so you add one + + align:start position:0% +is going to be neutral so you add one + + + align:start position:0% +is going to be neutral so you add one +yep that's right so this one um chlorine + + align:start position:0% +yep that's right so this one um chlorine + + + align:start position:0% +yep that's right so this one um chlorine +is usually minus one the exception is + + align:start position:0% +is usually minus one the exception is + + + align:start position:0% +is usually minus one the exception is +when it's with oxygen and so oxygen is + + align:start position:0% +when it's with oxygen and so oxygen is + + + align:start position:0% +when it's with oxygen and so oxygen is +always minus two unless it's in a + + align:start position:0% +always minus two unless it's in a + + + align:start position:0% +always minus two unless it's in a +peroxide or super oxide and hydrogen's + + align:start position:0% +peroxide or super oxide and hydrogen's + + + align:start position:0% +peroxide or super oxide and hydrogen's +always plus one except when it's with a + + align:start position:0% +always plus one except when it's with a + + + align:start position:0% +always plus one except when it's with a +metal like sodium um something group one + + align:start position:0% +metal like sodium um something group one + + + align:start position:0% +metal like sodium um something group one +or group two okay so today take out + + align:start position:0% +or group two okay so today take out + + + align:start position:0% +or group two okay so today take out +lecture 25 notes we're just going to + + align:start position:0% +lecture 25 notes we're just going to + + + align:start position:0% +lecture 25 notes we're just going to +wrap those notes up that shouldn't take + + align:start position:0% +wrap those notes up that shouldn't take + + + align:start position:0% +wrap those notes up that shouldn't take +too long and then keep going with + + align:start position:0% +too long and then keep going with + + + align:start position:0% +too long and then keep going with +lecture + + align:start position:0% +lecture + + + align:start position:0% +lecture +26 so we are talking about this cell and + + align:start position:0% +26 so we are talking about this cell and + + + align:start position:0% +26 so we are talking about this cell and +we're going to talk about this + + align:start position:0% +we're going to talk about this + + + align:start position:0% +we're going to talk about this +electrochemical cell a lot um so we had + + align:start position:0% +electrochemical cell a lot um so we had + + + align:start position:0% +electrochemical cell a lot um so we had +uh zinc on one side Zinc at the anode + + align:start position:0% +uh zinc on one side Zinc at the anode + + + align:start position:0% +uh zinc on one side Zinc at the anode +and the zinc was uh being oxidized + + align:start position:0% +and the zinc was uh being oxidized + + + align:start position:0% +and the zinc was uh being oxidized +generating electrons which come around + + align:start position:0% +generating electrons which come around + + + align:start position:0% +generating electrons which come around +to the copper and then the copper plus + + align:start position:0% +to the copper and then the copper plus + + + align:start position:0% +to the copper and then the copper plus +two ions were being reduced to Copper + + align:start position:0% +two ions were being reduced to Copper + + + align:start position:0% +two ions were being reduced to Copper +solid so the zinc um anode was being + + align:start position:0% +solid so the zinc um anode was being + + + align:start position:0% +solid so the zinc um anode was being +consumed and the copper cathode had + + align:start position:0% +consumed and the copper cathode had + + + align:start position:0% +consumed and the copper cathode had +copper solid being plated onto it so + + align:start position:0% +copper solid being plated onto it so + + + align:start position:0% +copper solid being plated onto it so +Faraday's law says that the amount at + + align:start position:0% +Faraday's law says that the amount at + + + align:start position:0% +Faraday's law says that the amount at +which an anode like the zinc anode is + + align:start position:0% +which an anode like the zinc anode is + + + align:start position:0% +which an anode like the zinc anode is +consumed and the amount of copper that + + align:start position:0% +consumed and the amount of copper that + + + align:start position:0% +consumed and the amount of copper that +gets plated on uh at the cathode is + + align:start position:0% +gets plated on uh at the cathode is + + + align:start position:0% +gets plated on uh at the cathode is +proportional to the charge that passes + + align:start position:0% +proportional to the charge that passes + + + align:start position:0% +proportional to the charge that passes +through the system so according to + + align:start position:0% +through the system so according to + + + align:start position:0% +through the system so according to +Faraday's law there's a proportionality + + align:start position:0% +Faraday's law there's a proportionality + + + align:start position:0% +Faraday's law there's a proportionality +between the consumption and uh also + + align:start position:0% +between the consumption and uh also + + + align:start position:0% +between the consumption and uh also +depositing of metal and the amount of + + align:start position:0% +depositing of metal and the amount of + + + align:start position:0% +depositing of metal and the amount of +charge going through the system so we + + align:start position:0% +charge going through the system so we + + + align:start position:0% +charge going through the system so we +can think about how much uh zinc is + + align:start position:0% +can think about how much uh zinc is + + + align:start position:0% +can think about how much uh zinc is +consumed and how much copper is + + align:start position:0% +consumed and how much copper is + + + align:start position:0% +consumed and how much copper is +deposited on its Ano on its cathode or + + align:start position:0% +deposited on its Ano on its cathode or + + + align:start position:0% +deposited on its Ano on its cathode or +its electrode um if the current if you + + align:start position:0% +its electrode um if the current if you + + + align:start position:0% +its electrode um if the current if you +have a current of one amp um flowing for + + align:start position:0% +have a current of one amp um flowing for + + + align:start position:0% +have a current of one amp um flowing for +one hour so let's just take a look at + + align:start position:0% +one hour so let's just take a look at + + + align:start position:0% +one hour so let's just take a look at +how we do a problem like this first step + + align:start position:0% +how we do a problem like this first step + + + align:start position:0% +how we do a problem like this first step +is we want to think about uh calculate + + align:start position:0% +is we want to think about uh calculate + + + align:start position:0% +is we want to think about uh calculate +the charge that's going through the the + + align:start position:0% +the charge that's going through the the + + + align:start position:0% +the charge that's going through the the +system and so Q here we have another q + + align:start position:0% +system and so Q here we have another q + + + align:start position:0% +system and so Q here we have another q +um not the reaction quotient but the + + align:start position:0% +um not the reaction quotient but the + + + align:start position:0% +um not the reaction quotient but the +magnitude of the charge and that's in + + align:start position:0% +magnitude of the charge and that's in + + + align:start position:0% +magnitude of the charge and that's in +kums and that's going to be equal to the + + align:start position:0% +kums and that's going to be equal to the + + + align:start position:0% +kums and that's going to be equal to the +current times the time so we have the + + align:start position:0% +current times the time so we have the + + + align:start position:0% +current times the time so we have the +current I and the current is in amps and + + align:start position:0% +current I and the current is in amps and + + + align:start position:0% +current I and the current is in amps and +T is in seconds and conveniently um amps + + align:start position:0% +T is in seconds and conveniently um amps + + + align:start position:0% +T is in seconds and conveniently um amps +equal kums per second so this equation + + align:start position:0% +equal kums per second so this equation + + + align:start position:0% +equal kums per second so this equation +works out our units uh will work out so + + align:start position:0% +works out our units uh will work out so + + + align:start position:0% +works out our units uh will work out so +Q is going to be equal to we have 1.08 + + align:start position:0% +Q is going to be equal to we have 1.08 + + + align:start position:0% +Q is going to be equal to we have 1.08 +amps um and it was 1 hour so that's uh + + align:start position:0% +amps um and it was 1 hour so that's uh + + + align:start position:0% +amps um and it was 1 hour so that's uh +3,600 seconds or + + align:start position:0% +3,600 seconds or + + + align:start position:0% +3,600 seconds or +3,600 kums because we have an amp times + + align:start position:0% +3,600 kums because we have an amp times + + + align:start position:0% +3,600 kums because we have an amp times +second um and then here we have this + + align:start position:0% +second um and then here we have this + + + align:start position:0% +second um and then here we have this +number of kums and now we want to + + align:start position:0% +number of kums and now we want to + + + align:start position:0% +number of kums and now we want to +convert to the number of moles of + + align:start position:0% +convert to the number of moles of + + + align:start position:0% +convert to the number of moles of +electrons that that is equivalent to + + align:start position:0% +electrons that that is equivalent to + + + align:start position:0% +electrons that that is equivalent to +that that charge in koloms is equivalent + + align:start position:0% +that that charge in koloms is equivalent + + + align:start position:0% +that that charge in koloms is equivalent +to and here our Faraday constant is our + + align:start position:0% +to and here our Faraday constant is our + + + align:start position:0% +to and here our Faraday constant is our +conversion Factor so Faraday is constant + + align:start position:0% +conversion Factor so Faraday is constant + + + align:start position:0% +conversion Factor so Faraday is constant +we have um + + align:start position:0% +we have um + + + align:start position:0% +we have um +9648 kums per mole is one Faraday and + + align:start position:0% +9648 kums per mole is one Faraday and + + + align:start position:0% +9648 kums per mole is one Faraday and +it's this kind of funny looking F over + + align:start position:0% +it's this kind of funny looking F over + + + align:start position:0% +it's this kind of funny looking F over +here so we have our kums so we can use + + align:start position:0% +here so we have our kums so we can use + + + align:start position:0% +here so we have our kums so we can use +now the feraday constant to convert and + + align:start position:0% +now the feraday constant to convert and + + + align:start position:0% +now the feraday constant to convert and +we get + + align:start position:0% +we get + + + align:start position:0% +we get +0373 moles of electrons so that's the + + align:start position:0% +0373 moles of electrons so that's the + + + align:start position:0% +0373 moles of electrons so that's the +number of moles of electrons that would + + align:start position:0% +number of moles of electrons that would + + + align:start position:0% +number of moles of electrons that would +be going through our system that + + align:start position:0% +be going through our system that + + + align:start position:0% +be going through our system that +correspond to that amount of charge + + align:start position:0% +correspond to that amount of charge + + + align:start position:0% +correspond to that amount of charge +all right so now we need to relate this + + align:start position:0% +all right so now we need to relate this + + + align:start position:0% +all right so now we need to relate this +back to the zinc and the copper so step + + align:start position:0% +back to the zinc and the copper so step + + + align:start position:0% +back to the zinc and the copper so step +three we want to know first the number + + align:start position:0% +three we want to know first the number + + + align:start position:0% +three we want to know first the number +of moles of the zinc and copper involved + + align:start position:0% +of moles of the zinc and copper involved + + + align:start position:0% +of moles of the zinc and copper involved +and then convert that to grams because + + align:start position:0% +and then convert that to grams because + + + align:start position:0% +and then convert that to grams because +the problem ask us for + + align:start position:0% +the problem ask us for + + + align:start position:0% +the problem ask us for +grams so we have the number of moles of + + align:start position:0% +grams so we have the number of moles of + + + align:start position:0% +grams so we have the number of moles of +electrons that are going through the + + align:start position:0% +electrons that are going through the + + + align:start position:0% +electrons that are going through the +system and so for every one mole of zinc + + align:start position:0% +system and so for every one mole of zinc + + + align:start position:0% +system and so for every one mole of zinc +consumed how many electrons go into the + + align:start position:0% +consumed how many electrons go into the + + + align:start position:0% +consumed how many electrons go into the +system what's the ratio one two how many + + align:start position:0% +system what's the ratio one two how many + + + align:start position:0% +system what's the ratio one two how many +elect + + align:start position:0% +elect + + + align:start position:0% +elect +R so one zinc solid going to one zinc + + align:start position:0% +R so one zinc solid going to one zinc + + + align:start position:0% +R so one zinc solid going to one zinc +plus two so that's going to be two moles + + align:start position:0% +plus two so that's going to be two moles + + + align:start position:0% +plus two so that's going to be two moles +of + + align:start position:0% + + + + align:start position:0% + +electrons and then we need to look up + + align:start position:0% +electrons and then we need to look up + + + align:start position:0% +electrons and then we need to look up +how are we going to convert our moles to + + align:start position:0% +how are we going to convert our moles to + + + align:start position:0% +how are we going to convert our moles to +grams what are we looking + + align:start position:0% + + + + align:start position:0% + +up y m Mass molecular weight atomic mass + + align:start position:0% +up y m Mass molecular weight atomic mass + + + align:start position:0% +up y m Mass molecular weight atomic mass +um so we in our periodic table grams per + + align:start position:0% +um so we in our periodic table grams per + + + align:start position:0% +um so we in our periodic table grams per +mole and so we get 1.2 grams here when + + align:start position:0% +mole and so we get 1.2 grams here when + + + align:start position:0% +mole and so we get 1.2 grams here when +for this equation all right so for + + align:start position:0% +for this equation all right so for + + + align:start position:0% +for this equation all right so for +copper so we have the same number of + + align:start position:0% +copper so we have the same number of + + + align:start position:0% +copper so we have the same number of +moles of electrons that are going + + align:start position:0% +moles of electrons that are going + + + align:start position:0% +moles of electrons that are going +through the system so for every one mole + + align:start position:0% +through the system so for every one mole + + + align:start position:0% +through the system so for every one mole +of copper solid deposited on its + + align:start position:0% +of copper solid deposited on its + + + align:start position:0% +of copper solid deposited on its +electrode how many moles of electrons + + align:start position:0% +electrode how many moles of electrons + + + align:start position:0% +electrode how many moles of electrons +have to come into the + + align:start position:0% +have to come into the + + + align:start position:0% +have to come into the +system louder two yes so that's two as + + align:start position:0% +system louder two yes so that's two as + + + align:start position:0% +system louder two yes so that's two as +well and then we look up again in the + + align:start position:0% +well and then we look up again in the + + + align:start position:0% +well and then we look up again in the +periodic table the uh atomic weight + + align:start position:0% +periodic table the uh atomic weight + + + align:start position:0% +periodic table the uh atomic weight +molecular weight um and it's almost the + + align:start position:0% +molecular weight um and it's almost the + + + align:start position:0% +molecular weight um and it's almost the +same copper and zinc so to the number of + + align:start position:0% +same copper and zinc so to the number of + + + align:start position:0% +same copper and zinc so to the number of +significant figures it's the same amount + + align:start position:0% +significant figures it's the same amount + + + align:start position:0% +significant figures it's the same amount +of grams now this will not always be the + + align:start position:0% +of grams now this will not always be the + + + align:start position:0% +of grams now this will not always be the +case um they're just very close to each + + align:start position:0% +case um they're just very close to each + + + align:start position:0% +case um they're just very close to each +other in uh in their molecular or atomic + + align:start position:0% +other in uh in their molecular or atomic + + + align:start position:0% +other in uh in their molecular or atomic +weight okay so we have two significant + + align:start position:0% +weight okay so we have two significant + + + align:start position:0% +weight okay so we have two significant +figures also our current and time only + + align:start position:0% +figures also our current and time only + + + align:start position:0% +figures also our current and time only +had two two significant figures so we + + align:start position:0% +had two two significant figures so we + + + align:start position:0% +had two two significant figures so we +only have two significant figures um in + + align:start position:0% +only have two significant figures um in + + + align:start position:0% +only have two significant figures um in +this + + align:start position:0% +this + + + align:start position:0% +this +problem all right so in this particular + + align:start position:0% +problem all right so in this particular + + + align:start position:0% +problem all right so in this particular +electrochemical cell again we had um our + + align:start position:0% +electrochemical cell again we had um our + + + align:start position:0% +electrochemical cell again we had um our +anode was being consumed and um the + + align:start position:0% +anode was being consumed and um the + + + align:start position:0% +anode was being consumed and um the +electrons that were generated um ended + + align:start position:0% +electrons that were generated um ended + + + align:start position:0% +electrons that were generated um ended +up plating the copper on sometimes + + align:start position:0% +up plating the copper on sometimes + + + align:start position:0% +up plating the copper on sometimes +you're not going to want to do that + + align:start position:0% +you're not going to want to do that + + + align:start position:0% +you're not going to want to do that +sometimes you're just going to want to + + align:start position:0% +sometimes you're just going to want to + + + align:start position:0% +sometimes you're just going to want to +actually plate um something with copper + + align:start position:0% +actually plate um something with copper + + + align:start position:0% +actually plate um something with copper +for example and so let's uh look at some + + align:start position:0% +for example and so let's uh look at some + + + align:start position:0% +for example and so let's uh look at some +of the uses for this kind of chemistry + + align:start position:0% +of the uses for this kind of chemistry + + + align:start position:0% +of the uses for this kind of chemistry +so here's some + + align:start position:0% + + + + align:start position:0% + +electroplating this steel spoon will + + align:start position:0% +electroplating this steel spoon will + + + align:start position:0% +electroplating this steel spoon will +have a thin coating of copper deposited + + align:start position:0% +have a thin coating of copper deposited + + + align:start position:0% +have a thin coating of copper deposited +on it the cell consists of an anode of + + align:start position:0% +on it the cell consists of an anode of + + + align:start position:0% +on it the cell consists of an anode of +pure copper a solution of copper sulfate + + align:start position:0% +pure copper a solution of copper sulfate + + + align:start position:0% +pure copper a solution of copper sulfate +and as a cathode a spoon there is no net + + align:start position:0% +and as a cathode a spoon there is no net + + + align:start position:0% +and as a cathode a spoon there is no net +reaction but copper metal is transferred + + align:start position:0% +reaction but copper metal is transferred + + + align:start position:0% +reaction but copper metal is transferred +from the anode to the + + align:start position:0% + + + + align:start position:0% + +cathode it's pretty nice + + align:start position:0% + + + + align:start position:0% + +okay so this kind of electroplating is + + align:start position:0% +okay so this kind of electroplating is + + + align:start position:0% +okay so this kind of electroplating is +pretty common um where you use these + + align:start position:0% +pretty common um where you use these + + + align:start position:0% +pretty common um where you use these +kind of reactions to get your copper + + align:start position:0% +kind of reactions to get your copper + + + align:start position:0% +kind of reactions to get your copper +which is in that solution to um to to + + align:start position:0% +which is in that solution to um to to + + + align:start position:0% +which is in that solution to um to to +plate as copper solid onto something so + + align:start position:0% +plate as copper solid onto something so + + + align:start position:0% +plate as copper solid onto something so +it could be a spoon it could be + + align:start position:0% +it could be a spoon it could be + + + align:start position:0% +it could be a spoon it could be +electrode yeah why is it dangerous why + + align:start position:0% +electrode yeah why is it dangerous why + + + align:start position:0% +electrode yeah why is it dangerous why +is it dangerous I you know I've seen + + align:start position:0% +is it dangerous I you know I've seen + + + align:start position:0% +is it dangerous I you know I've seen +these demos before so I'm not I'm not I + + align:start position:0% +these demos before so I'm not I'm not I + + + align:start position:0% +these demos before so I'm not I'm not I +think that they that's just like + + align:start position:0% +think that they that's just like + + + align:start position:0% +think that they that's just like +security regions to to say to say that I + + align:start position:0% +security regions to to say to say that I + + + align:start position:0% +security regions to to say to say that I +don't think it's like incred dangerous + + align:start position:0% +don't think it's like incred dangerous + + + align:start position:0% +don't think it's like incred dangerous +frankly but I probably shouldn't say + + align:start position:0% +frankly but I probably shouldn't say + + + align:start position:0% +frankly but I probably shouldn't say +that I'll get myself into all sorts of + + align:start position:0% +that I'll get myself into all sorts of + + + align:start position:0% +that I'll get myself into all sorts of +trouble don't try this at home I don't + + align:start position:0% +trouble don't try this at home I don't + + + align:start position:0% +trouble don't try this at home I don't +know why all right um usually when + + align:start position:0% +know why all right um usually when + + + align:start position:0% +know why all right um usually when +theuse + + align:start position:0% +theuse + + + align:start position:0% +theuse +are yeah but not like not that much + + align:start position:0% +are yeah but not like not that much + + + align:start position:0% +are yeah but not like not that much +worse than a lab stuff yeah Elena makes + + align:start position:0% +worse than a lab stuff yeah Elena makes + + + align:start position:0% +worse than a lab stuff yeah Elena makes +jewelry so she knows all about this but + + align:start position:0% +jewelry so she knows all about this but + + + align:start position:0% +jewelry so she knows all about this but +she doesn't she doesn't she does it very + + align:start position:0% +she doesn't she doesn't she does it very + + + align:start position:0% +she doesn't she doesn't she does it very +safely very safely okay all right so + + align:start position:0% +safely very safely okay all right so + + + align:start position:0% +safely very safely okay all right so +let's look at a couple other kinds of + + align:start position:0% +let's look at a couple other kinds of + + + align:start position:0% +let's look at a couple other kinds of +electrodes it is not always the case + + align:start position:0% +electrodes it is not always the case + + + align:start position:0% +electrodes it is not always the case +that electrode is consumed or that an + + align:start position:0% +that electrode is consumed or that an + + + align:start position:0% +that electrode is consumed or that an +electrode gets stuff deposited on it + + align:start position:0% +electrode gets stuff deposited on it + + + align:start position:0% +electrode gets stuff deposited on it +some electrodes are inert um an example + + align:start position:0% +some electrodes are inert um an example + + + align:start position:0% +some electrodes are inert um an example +for this is a platinum electrode it is + + align:start position:0% +for this is a platinum electrode it is + + + align:start position:0% +for this is a platinum electrode it is +inert so it doesn't get consumed and it + + align:start position:0% +inert so it doesn't get consumed and it + + + align:start position:0% +inert so it doesn't get consumed and it +doesn't get um reacted onto um during + + align:start position:0% +doesn't get um reacted onto um during + + + align:start position:0% +doesn't get um reacted onto um during +the reaction and so here's an example of + + align:start position:0% +the reaction and so here's an example of + + + align:start position:0% +the reaction and so here's an example of +a cell that uses this um so over here + + align:start position:0% +a cell that uses this um so over here + + + align:start position:0% +a cell that uses this um so over here +now we have still our copper system so + + align:start position:0% +now we have still our copper system so + + + align:start position:0% +now we have still our copper system so +this is our cathode again over here and + + align:start position:0% +this is our cathode again over here and + + + align:start position:0% +this is our cathode again over here and +a cathode does what oxidation or + + align:start position:0% +a cathode does what oxidation or + + + align:start position:0% +a cathode does what oxidation or +reduction where reduction and so this is + + align:start position:0% +reduction where reduction and so this is + + + align:start position:0% +reduction where reduction and so this is +our same reaction um copper plus two two + + align:start position:0% +our same reaction um copper plus two two + + + align:start position:0% +our same reaction um copper plus two two +electrodes code to Copper solid so this + + align:start position:0% +electrodes code to Copper solid so this + + + align:start position:0% +electrodes code to Copper solid so this +is doing the plating again but in this + + align:start position:0% +is doing the plating again but in this + + + align:start position:0% +is doing the plating again but in this +time it's different before we had the + + align:start position:0% +time it's different before we had the + + + align:start position:0% +time it's different before we had the +zinc um electrode that was being + + align:start position:0% +zinc um electrode that was being + + + align:start position:0% +zinc um electrode that was being +consumed but now we have this platinum + + align:start position:0% +consumed but now we have this platinum + + + align:start position:0% +consumed but now we have this platinum +and the reaction that happens at the + + align:start position:0% +and the reaction that happens at the + + + align:start position:0% +and the reaction that happens at the +anode it's still an oxidation always an + + align:start position:0% +anode it's still an oxidation always an + + + align:start position:0% +anode it's still an oxidation always an +oxidation at the anode but the oxidation + + align:start position:0% +oxidation at the anode but the oxidation + + + align:start position:0% +oxidation at the anode but the oxidation +reaction is chromium plus two going to + + align:start position:0% +reaction is chromium plus two going to + + + align:start position:0% +reaction is chromium plus two going to +chromium plus three in an electron so um + + align:start position:0% +chromium plus three in an electron so um + + + align:start position:0% +chromium plus three in an electron so um +here the electrode is inert and the + + align:start position:0% +here the electrode is inert and the + + + align:start position:0% +here the electrode is inert and the +reaction is all happening in the same + + align:start position:0% +reaction is all happening in the same + + + align:start position:0% +reaction is all happening in the same +phase all happening in + + align:start position:0% +phase all happening in + + + align:start position:0% +phase all happening in +solution so we can also write the uh not + + align:start position:0% +solution so we can also write the uh not + + + align:start position:0% +solution so we can also write the uh not +the notation for this kind of cell and + + align:start position:0% +the notation for this kind of cell and + + + align:start position:0% +the notation for this kind of cell and +so here we would have Platinum solid the + + align:start position:0% +so here we would have Platinum solid the + + + align:start position:0% +so here we would have Platinum solid the +single line which means the phase + + align:start position:0% +single line which means the phase + + + align:start position:0% +single line which means the phase +difference um chromium plus two aquous + + align:start position:0% +difference um chromium plus two aquous + + + align:start position:0% +difference um chromium plus two aquous +comma because now there's not a a phase + + align:start position:0% +comma because now there's not a a phase + + + align:start position:0% +comma because now there's not a a phase +transition between these a chromium plus + + align:start position:0% +transition between these a chromium plus + + + align:start position:0% +transition between these a chromium plus +three aquous the two lines that means + + align:start position:0% +three aquous the two lines that means + + + align:start position:0% +three aquous the two lines that means +what what do those mean + + align:start position:0% +what what do those mean + + + align:start position:0% +what what do those mean +again salt bridge so this indicates + + align:start position:0% +again salt bridge so this indicates + + + align:start position:0% +again salt bridge so this indicates +that's one Beaker this is the other + + align:start position:0% +that's one Beaker this is the other + + + align:start position:0% +that's one Beaker this is the other +Beaker and here we have the copper plus + + align:start position:0% +Beaker and here we have the copper plus + + + align:start position:0% +Beaker and here we have the copper plus +two Aqua single line for phase uh change + + align:start position:0% +two Aqua single line for phase uh change + + + align:start position:0% +two Aqua single line for phase uh change +and a copper solid so again our anode + + align:start position:0% +and a copper solid so again our anode + + + align:start position:0% +and a copper solid so again our anode +reaction and our cathode + + align:start position:0% +reaction and our cathode + + + align:start position:0% +reaction and our cathode +reaction all right so this is another + + align:start position:0% +reaction all right so this is another + + + align:start position:0% +reaction all right so this is another +kind um you can also use platinum + + align:start position:0% +kind um you can also use platinum + + + align:start position:0% +kind um you can also use platinum +electrodes in combination with what's + + align:start position:0% +electrodes in combination with what's + + + align:start position:0% +electrodes in combination with what's +known as a hydrogen electrode um so + + align:start position:0% +known as a hydrogen electrode um so + + + align:start position:0% +known as a hydrogen electrode um so +these are often together the Platinum + + align:start position:0% +these are often together the Platinum + + + align:start position:0% +these are often together the Platinum +with the hydrogen + + align:start position:0% +with the hydrogen + + + align:start position:0% +with the hydrogen +and many reduction potentials and when + + align:start position:0% +and many reduction potentials and when + + + align:start position:0% +and many reduction potentials and when +you get problem set 8 you're going to be + + align:start position:0% +you get problem set 8 you're going to be + + + align:start position:0% +you get problem set 8 you're going to be +looking up in your book a lot of + + align:start position:0% +looking up in your book a lot of + + + align:start position:0% +looking up in your book a lot of +standard reduction potentials and many + + align:start position:0% +standard reduction potentials and many + + + align:start position:0% +standard reduction potentials and many +of them will say measured against sh and + + align:start position:0% +of them will say measured against sh and + + + align:start position:0% +of them will say measured against sh and +a lot of people say like who is this she + + align:start position:0% +a lot of people say like who is this she + + + align:start position:0% +a lot of people say like who is this she +that measures all of these uh Potentials + + align:start position:0% +that measures all of these uh Potentials + + + align:start position:0% +that measures all of these uh Potentials +in the back of books and that she is the + + align:start position:0% +in the back of books and that she is the + + + align:start position:0% +in the back of books and that she is the +standard hydrogen electrode all right so + + align:start position:0% +standard hydrogen electrode all right so + + + align:start position:0% +standard hydrogen electrode all right so +let's think about how this electrode is + + align:start position:0% +let's think about how this electrode is + + + align:start position:0% +let's think about how this electrode is +being used so we when it's used used as + + align:start position:0% +being used so we when it's used used as + + + align:start position:0% +being used so we when it's used used as +a cathode we have um H+ aquous phase + + align:start position:0% +a cathode we have um H+ aquous phase + + + align:start position:0% +a cathode we have um H+ aquous phase +transition to H2 gas and then another + + align:start position:0% +transition to H2 gas and then another + + + align:start position:0% +transition to H2 gas and then another +phase transition to our solid Platinum + + align:start position:0% +phase transition to our solid Platinum + + + align:start position:0% +phase transition to our solid Platinum +inert electrode and here when it's used + + align:start position:0% +inert electrode and here when it's used + + + align:start position:0% +inert electrode and here when it's used +as a cathode H+ is being + + align:start position:0% +as a cathode H+ is being + + + align:start position:0% +as a cathode H+ is being +reduced but it can also be used as an + + align:start position:0% +reduced but it can also be used as an + + + align:start position:0% +reduced but it can also be used as an +anode and this is a clicker question why + + align:start position:0% +anode and this is a clicker question why + + + align:start position:0% +anode and this is a clicker question why +don't you tell me what would be + + align:start position:0% +don't you tell me what would be + + + align:start position:0% +don't you tell me what would be +happening when the hydrogen Platinum + + align:start position:0% +happening when the hydrogen Platinum + + + align:start position:0% +happening when the hydrogen Platinum +electrode is being used as an anode or + + align:start position:0% +electrode is being used as an anode or + + + align:start position:0% +electrode is being used as an anode or +reactions being used as an + + align:start position:0% + + + + align:start position:0% + +anode 10 + + align:start position:0% + + + + align:start position:0% + +seconds see if you can get 90% 89 + + align:start position:0% + + + + align:start position:0% + +89% oh + + align:start position:0% +89% oh + + + align:start position:0% +89% oh +far away okay that is the right answer + + align:start position:0% +far away okay that is the right answer + + + align:start position:0% +far away okay that is the right answer +though okay so some of these um the + + align:start position:0% +though okay so some of these um the + + + align:start position:0% +though okay so some of these um the +Platinum is inert so it's not doing + + align:start position:0% +Platinum is inert so it's not doing + + + align:start position:0% +Platinum is inert so it's not doing +anything um and it's over here so it's + + align:start position:0% +anything um and it's over here so it's + + + align:start position:0% +anything um and it's over here so it's +not doing anything so we can rule out + + align:start position:0% +not doing anything so we can rule out + + + align:start position:0% +not doing anything so we can rule out +all the things that Platinum are doing + + align:start position:0% +all the things that Platinum are doing + + + align:start position:0% +all the things that Platinum are doing +stuff all + + align:start position:0% +stuff all + + + align:start position:0% +stuff all +right H+ being oxidized you ever heard + + align:start position:0% +right H+ being oxidized you ever heard + + + align:start position:0% +right H+ being oxidized you ever heard +of + + align:start position:0% + + + + align:start position:0% + +h2+ no so we don't want that we know at + + align:start position:0% +h2+ no so we don't want that we know at + + + align:start position:0% +h2+ no so we don't want that we know at +the anode it should be oxidized so we + + align:start position:0% +the anode it should be oxidized so we + + + align:start position:0% +the anode it should be oxidized so we +can eliminate all the ones that are + + align:start position:0% +can eliminate all the ones that are + + + align:start position:0% +can eliminate all the ones that are +reduced okay so we only have really kind + + align:start position:0% +reduced okay so we only have really kind + + + align:start position:0% +reduced okay so we only have really kind +of one good option if you say that the + + align:start position:0% +of one good option if you say that the + + + align:start position:0% +of one good option if you say that the +Platinum um is in Earth so H2 then gets + + align:start position:0% +Platinum um is in Earth so H2 then gets + + + align:start position:0% +Platinum um is in Earth so H2 then gets +oxidized in this case forming H+ all + + align:start position:0% +oxidized in this case forming H+ all + + + align:start position:0% +oxidized in this case forming H+ all +right so let's uh let's look at a let's + + align:start position:0% +right so let's uh let's look at a let's + + + align:start position:0% +right so let's uh let's look at a let's +look at a cell like this that uh uses + + align:start position:0% +look at a cell like this that uh uses + + + align:start position:0% +look at a cell like this that uh uses +the uh the hydrogen + + align:start position:0% +the uh the hydrogen + + + align:start position:0% +the uh the hydrogen +electrode so here's an example now on + + align:start position:0% +electrode so here's an example now on + + + align:start position:0% +electrode so here's an example now on +this side we have our regular zinc + + align:start position:0% +this side we have our regular zinc + + + align:start position:0% +this side we have our regular zinc +system system for our anode and so over + + align:start position:0% +system system for our anode and so over + + + align:start position:0% +system system for our anode and so over +here we're using as the cathode the + + align:start position:0% +here we're using as the cathode the + + + align:start position:0% +here we're using as the cathode the +hydrogen electrode and so here in this + + align:start position:0% +hydrogen electrode and so here in this + + + align:start position:0% +hydrogen electrode and so here in this +beautiful drawing that I made um we have + + align:start position:0% +beautiful drawing that I made um we have + + + align:start position:0% +beautiful drawing that I made um we have +a glass tube here where you're pumping + + align:start position:0% +a glass tube here where you're pumping + + + align:start position:0% +a glass tube here where you're pumping +H2 gas in at one atmosphere in the + + align:start position:0% +H2 gas in at one atmosphere in the + + + align:start position:0% +H2 gas in at one atmosphere in the +middle of the tube we have our inert + + align:start position:0% +middle of the tube we have our inert + + + align:start position:0% +middle of the tube we have our inert +Platinum uh electrode and then these are + + align:start position:0% +Platinum uh electrode and then these are + + + align:start position:0% +Platinum uh electrode and then these are +H2 gas bubbles down here and we have + + align:start position:0% +H2 gas bubbles down here and we have + + + align:start position:0% +H2 gas bubbles down here and we have +strong acid HCL which is our source of + + align:start position:0% +strong acid HCL which is our source of + + + align:start position:0% +strong acid HCL which is our source of +H+ + + align:start position:0% +H+ + + + align:start position:0% +H+ +um in solution so over here again this + + align:start position:0% +um in solution so over here again this + + + align:start position:0% +um in solution so over here again this +is our cathode so we have a reduction at + + align:start position:0% +is our cathode so we have a reduction at + + + align:start position:0% +is our cathode so we have a reduction at +the cathode and we have H+ aquous phase + + align:start position:0% +the cathode and we have H+ aquous phase + + + align:start position:0% +the cathode and we have H+ aquous phase +transition H2 and gas and then another + + align:start position:0% +transition H2 and gas and then another + + + align:start position:0% +transition H2 and gas and then another +phase transition to our solid Platinum + + align:start position:0% +phase transition to our solid Platinum + + + align:start position:0% +phase transition to our solid Platinum +electrode and over here is our standard + + align:start position:0% +electrode and over here is our standard + + + align:start position:0% +electrode and over here is our standard +anode our oxidation that involves zinc + + align:start position:0% +anode our oxidation that involves zinc + + + align:start position:0% +anode our oxidation that involves zinc +and zinc plus two so we could also have + + align:start position:0% +and zinc plus two so we could also have + + + align:start position:0% +and zinc plus two so we could also have +had um the hydrogen electrode over here + + align:start position:0% +had um the hydrogen electrode over here + + + align:start position:0% +had um the hydrogen electrode over here +as well all right so that gives you a + + align:start position:0% +as well all right so that gives you a + + + align:start position:0% +as well all right so that gives you a +number of different examples of types of + + align:start position:0% +number of different examples of types of + + + align:start position:0% +number of different examples of types of +electrodes that you can have and types + + align:start position:0% +electrodes that you can have and types + + + align:start position:0% +electrodes that you can have and types +of cells that you can have um and uh and + + align:start position:0% +of cells that you can have um and uh and + + + align:start position:0% +of cells that you can have um and uh and +that is the end of this um + + align:start position:0% +that is the end of this um + + + align:start position:0% +that is the end of this um +today's our lecture 25 notes as soon as + + align:start position:0% +today's our lecture 25 notes as soon as + + + align:start position:0% +today's our lecture 25 notes as soon as +you finish writing that down we'll go + + align:start position:0% +you finish writing that down we'll go + + + align:start position:0% +you finish writing that down we'll go +and look at lecture 26 again we're + + align:start position:0% +and look at lecture 26 again we're + + + align:start position:0% +and look at lecture 26 again we're +continuing on the same theme and now + + align:start position:0% +continuing on the same theme and now + + + align:start position:0% +continuing on the same theme and now +we're going to talk about the potential + + align:start position:0% +we're going to talk about the potential + + + align:start position:0% +we're going to talk about the potential +of these cells so we've talked about the + + align:start position:0% +of these cells so we've talked about the + + + align:start position:0% +of these cells so we've talked about the +reactions happening at anodes and + + align:start position:0% +reactions happening at anodes and + + + align:start position:0% +reactions happening at anodes and +cathodes how to write them and now we're + + align:start position:0% +cathodes how to write them and now we're + + + align:start position:0% +cathodes how to write them and now we're +going to think about the change and + + align:start position:0% +going to think about the change and + + + align:start position:0% +going to think about the change and +potential that occurs when you run these + + align:start position:0% +potential that occurs when you run these + + + align:start position:0% +potential that occurs when you run these +reactions \ No newline at end of file diff --git a/CEbrxYGpfZY.txt b/CEbrxYGpfZY.txt new file mode 100644 index 0000000000000000000000000000000000000000..e64451fd5193ab50551413b55012d167f6e48977 --- /dev/null +++ b/CEbrxYGpfZY.txt @@ -0,0 +1,6832 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit mitop courseware at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +hi as I was getting myself prepared for + + align:start position:0% +hi as I was getting myself prepared for + + + align:start position:0% +hi as I was getting myself prepared for +the lecture an old Shaggy Dog science + + align:start position:0% +the lecture an old Shaggy Dog science + + + align:start position:0% +the lecture an old Shaggy Dog science +story came to mind that's usually told + + align:start position:0% +story came to mind that's usually told + + + align:start position:0% +story came to mind that's usually told +as a tribute to the German scientist + + align:start position:0% +as a tribute to the German scientist + + + align:start position:0% +as a tribute to the German scientist +thoroughness this was a story of when + + align:start position:0% +thoroughness this was a story of when + + + align:start position:0% +thoroughness this was a story of when +all the scientists of the world got + + align:start position:0% +all the scientists of the world got + + + align:start position:0% +all the scientists of the world got +together and decided for an annual + + align:start position:0% +together and decided for an annual + + + align:start position:0% +together and decided for an annual +project each country would study + + align:start position:0% +project each country would study + + + align:start position:0% +project each country would study +exhaustively a different animal and + + align:start position:0% +exhaustively a different animal and + + + align:start position:0% +exhaustively a different animal and +report at the end of a year as to what + + align:start position:0% +report at the end of a year as to what + + + align:start position:0% +report at the end of a year as to what +they had found out and at the end of the + + align:start position:0% +they had found out and at the end of the + + + align:start position:0% +they had found out and at the end of the +year every country but Germany had been + + align:start position:0% +year every country but Germany had been + + + align:start position:0% +year every country but Germany had been +heard from no one knew what had happened + + align:start position:0% +heard from no one knew what had happened + + + align:start position:0% +heard from no one knew what had happened +to the German scientists and 5 years + + align:start position:0% +to the German scientists and 5 years + + + align:start position:0% +to the German scientists and 5 years +later the German report came in a huge + + align:start position:0% +later the German report came in a huge + + + align:start position:0% +later the German report came in a huge +epitome and it was entitled Handbook of + + align:start position:0% +epitome and it was entitled Handbook of + + + align:start position:0% +epitome and it was entitled Handbook of +the elephant volume one and the reason + + align:start position:0% +the elephant volume one and the reason + + + align:start position:0% +the elephant volume one and the reason +that this story comes to mind is toold + + align:start position:0% +that this story comes to mind is toold + + + align:start position:0% +that this story comes to mind is toold +first of all the study of vector spaces + + align:start position:0% +first of all the study of vector spaces + + + align:start position:0% +first of all the study of vector spaces +has so many ramifications that to study + + align:start position:0% +has so many ramifications that to study + + + align:start position:0% +has so many ramifications that to study +the subject thoroughly should be a full + + align:start position:0% +the subject thoroughly should be a full + + + align:start position:0% +the subject thoroughly should be a full +Year's course by itself and secondly + + align:start position:0% +Year's course by itself and secondly + + + align:start position:0% +Year's course by itself and secondly +with respect ECT to the particular topic + + align:start position:0% +with respect ECT to the particular topic + + + align:start position:0% +with respect ECT to the particular topic +of basis vectors and spanning vectors + + align:start position:0% +of basis vectors and spanning vectors + + + align:start position:0% +of basis vectors and spanning vectors +and whether sub elements are linearly + + align:start position:0% +and whether sub elements are linearly + + + align:start position:0% +and whether sub elements are linearly +independent whereas we've invented a + + align:start position:0% +independent whereas we've invented a + + + align:start position:0% +independent whereas we've invented a +rather nice row reduced Matrix technique + + align:start position:0% +rather nice row reduced Matrix technique + + + align:start position:0% +rather nice row reduced Matrix technique +for finding out + + align:start position:0% +for finding out + + + align:start position:0% +for finding out +what space is Spann by a set of vectors + + align:start position:0% +what space is Spann by a set of vectors + + + align:start position:0% +what space is Spann by a set of vectors +and what a basis for that space is + + align:start position:0% +and what a basis for that space is + + + align:start position:0% +and what a basis for that space is +frequently we don't want that much + + align:start position:0% +frequently we don't want that much + + + align:start position:0% +frequently we don't want that much +information and what I'm leading up to + + align:start position:0% +information and what I'm leading up to + + + align:start position:0% +information and what I'm leading up to +is a topic which you've all had in a + + align:start position:0% +is a topic which you've all had in a + + + align:start position:0% +is a topic which you've all had in a +previous context it's called + + align:start position:0% +previous context it's called + + + align:start position:0% +previous context it's called +determinants and today what I would like + + align:start position:0% +determinants and today what I would like + + + align:start position:0% +determinants and today what I would like +to do is to study determinants within + + align:start position:0% +to do is to study determinants within + + + align:start position:0% +to do is to study determinants within +the framework of of vector spaces and + + align:start position:0% +the framework of of vector spaces and + + + align:start position:0% +the framework of of vector spaces and +the way it comes up is as follows + + align:start position:0% +the way it comes up is as follows + + + align:start position:0% +the way it comes up is as follows +suppose we have an N dimensional Vector + + align:start position:0% +suppose we have an N dimensional Vector + + + align:start position:0% +suppose we have an N dimensional Vector +space V and suppose that we pick a + + align:start position:0% +space V and suppose that we pick a + + + align:start position:0% +space V and suppose that we pick a +particular basis U1 up to unu n for V + + align:start position:0% +particular basis U1 up to unu n for V + + + align:start position:0% +particular basis U1 up to unu n for V +itself now the idea is this knowing that + + align:start position:0% +itself now the idea is this knowing that + + + align:start position:0% +itself now the idea is this knowing that +the dimension of V is n we immediately + + align:start position:0% +the dimension of V is n we immediately + + + align:start position:0% +the dimension of V is n we immediately +know that more than n vectors can't be a + + align:start position:0% +know that more than n vectors can't be a + + + align:start position:0% +know that more than n vectors can't be a +basis for V because they will be + + align:start position:0% +basis for V because they will be + + + align:start position:0% +basis for V because they will be +linearly dependent rather than linearly + + align:start position:0% +linearly dependent rather than linearly + + + align:start position:0% +linearly dependent rather than linearly +independent + + align:start position:0% +independent + + + align:start position:0% +independent +fewer than n vectors of V cannot be a + + align:start position:0% +fewer than n vectors of V cannot be a + + + align:start position:0% +fewer than n vectors of V cannot be a +basis because fewer than n vectors since + + align:start position:0% +basis because fewer than n vectors since + + + align:start position:0% +basis because fewer than n vectors since +the dimension is n cannot span V + + align:start position:0% +the dimension is n cannot span V + + + align:start position:0% +the dimension is n cannot span V +consequently the only point of interest + + align:start position:0% +consequently the only point of interest + + + align:start position:0% +consequently the only point of interest +is what happens when we're given a set + + align:start position:0% +is what happens when we're given a set + + + align:start position:0% +is what happens when we're given a set +of n vectors in V namely given the N + + align:start position:0% +of n vectors in V namely given the N + + + align:start position:0% +of n vectors in V namely given the N +vectors Alpha One up to alpha n and + + align:start position:0% +vectors Alpha One up to alpha n and + + + align:start position:0% +vectors Alpha One up to alpha n and +V is this set a basis or isn't it and + + align:start position:0% +V is this set a basis or isn't it and + + + align:start position:0% +V is this set a basis or isn't it and +rather than to use the row reduced + + align:start position:0% +rather than to use the row reduced + + + align:start position:0% +rather than to use the row reduced +Matrix technique here what we're saying + + align:start position:0% +Matrix technique here what we're saying + + + align:start position:0% +Matrix technique here what we're saying +is we don't want for example in many + + align:start position:0% +is we don't want for example in many + + + align:start position:0% +is we don't want for example in many +cases to know what the betas look like + + align:start position:0% +cases to know what the betas look like + + + align:start position:0% +cases to know what the betas look like +that we talked about in our lecture on + + align:start position:0% +that we talked about in our lecture on + + + align:start position:0% +that we talked about in our lecture on +spanning vectors and the like all we + + align:start position:0% +spanning vectors and the like all we + + + align:start position:0% +spanning vectors and the like all we +want to know is are these vectors + + align:start position:0% +want to know is are these vectors + + + align:start position:0% +want to know is are these vectors +linearly independent or aren't they and + + align:start position:0% +linearly independent or aren't they and + + + align:start position:0% +linearly independent or aren't they and +so what we do is we essentially invent a + + align:start position:0% +so what we do is we essentially invent a + + + align:start position:0% +so what we do is we essentially invent a +function machine in other words what + + align:start position:0% +function machine in other words what + + + align:start position:0% +function machine in other words what +we're going to do is to construct a + + align:start position:0% +we're going to do is to construct a + + + align:start position:0% +we're going to do is to construct a +function in which given that the + + align:start position:0% +function in which given that the + + + align:start position:0% +function in which given that the +dimension of our space is n-dimensional + + align:start position:0% +dimension of our space is n-dimensional + + + align:start position:0% +dimension of our space is n-dimensional +the input of our function machine will + + align:start position:0% +the input of our function machine will + + + align:start position:0% +the input of our function machine will +be any set of n vectors from that space + + align:start position:0% +be any set of n vectors from that space + + + align:start position:0% +be any set of n vectors from that space +and the Machine will be programmed to + + align:start position:0% +and the Machine will be programmed to + + + align:start position:0% +and the Machine will be programmed to +give zero as an output if the vectors + + align:start position:0% +give zero as an output if the vectors + + + align:start position:0% +give zero as an output if the vectors +are linearly dependent in other words if + + align:start position:0% +are linearly dependent in other words if + + + align:start position:0% +are linearly dependent in other words if +they're not a basis and nonzero and I'll + + align:start position:0% +they're not a basis and nonzero and I'll + + + align:start position:0% +they're not a basis and nonzero and I'll +explain in more detail what nonzero why + + align:start position:0% +explain in more detail what nonzero why + + + align:start position:0% +explain in more detail what nonzero why +I pick nonzero rather than a specific + + align:start position:0% +I pick nonzero rather than a specific + + + align:start position:0% +I pick nonzero rather than a specific +nonzero number if the basis V if the N + + align:start position:0% +nonzero number if the basis V if the N + + + align:start position:0% +nonzero number if the basis V if the N +vectors do form a basis in other words I + + align:start position:0% +vectors do form a basis in other words I + + + align:start position:0% +vectors do form a basis in other words I +am going to invent a function D capital + + align:start position:0% +am going to invent a function D capital + + + align:start position:0% +am going to invent a function D capital +d to indicate the wood that determinant + + align:start position:0% +d to indicate the wood that determinant + + + align:start position:0% +d to indicate the wood that determinant +here such that D of the N vectors alpha + + align:start position:0% +here such that D of the N vectors alpha + + + align:start position:0% +here such that D of the N vectors alpha +1 up to alpha n will be zero if and only + + align:start position:0% +1 up to alpha n will be zero if and only + + + align:start position:0% +1 up to alpha n will be zero if and only +if the set of n vectors are linearly + + align:start position:0% +if the set of n vectors are linearly + + + align:start position:0% +if the set of n vectors are linearly +dependent now obviously a function + + align:start position:0% +dependent now obviously a function + + + align:start position:0% +dependent now obviously a function +machine can do nothing by itself we have + + align:start position:0% +machine can do nothing by itself we have + + + align:start position:0% +machine can do nothing by itself we have +to give and I hope this is well known by + + align:start position:0% +to give and I hope this is well known by + + + align:start position:0% +to give and I hope this is well known by +now in our course we have to endow any + + align:start position:0% +now in our course we have to endow any + + + align:start position:0% +now in our course we have to endow any +thing that we're working with with a + + align:start position:0% +thing that we're working with with a + + + align:start position:0% +thing that we're working with with a +particular structure so it feels free to + + align:start position:0% +particular structure so it feels free to + + + align:start position:0% +particular structure so it feels free to +work logically for us well among other + + align:start position:0% +work logically for us well among other + + + align:start position:0% +work logically for us well among other +things what do we know for sure is a set + + align:start position:0% +things what do we know for sure is a set + + + align:start position:0% +things what do we know for sure is a set +of n vectors which are a basis for V + + align:start position:0% +of n vectors which are a basis for V + + + align:start position:0% +of n vectors which are a basis for V +since we were given that the specific + + align:start position:0% +since we were given that the specific + + + align:start position:0% +since we were given that the specific +basis that V is being referred to with + + align:start position:0% +basis that V is being referred to with + + + align:start position:0% +basis that V is being referred to with +respect to uh U1 up to un then certainly + + align:start position:0% +respect to uh U1 up to un then certainly + + + align:start position:0% +respect to uh U1 up to un then certainly +if U1 up to un is the input of the D + + align:start position:0% +if U1 up to un is the input of the D + + + align:start position:0% +if U1 up to un is the input of the D +machine we want a nonzero output for the + + align:start position:0% +machine we want a nonzero output for the + + + align:start position:0% +machine we want a nonzero output for the +sake of just normalizing thing things + + align:start position:0% +sake of just normalizing thing things + + + align:start position:0% +sake of just normalizing thing things +let's program the machine so that D of + + align:start position:0% +let's program the machine so that D of + + + align:start position:0% +let's program the machine so that D of +U1 up to un will be + + align:start position:0% +U1 up to un will be + + + align:start position:0% +U1 up to un will be +one now notice by the way this only + + align:start position:0% +one now notice by the way this only + + + align:start position:0% +one now notice by the way this only +tells us one special basis there are + + align:start position:0% +tells us one special basis there are + + + align:start position:0% +tells us one special basis there are +many bases that I could have chosen for + + align:start position:0% +many bases that I could have chosen for + + + align:start position:0% +many bases that I could have chosen for +V and certainly condition one by itself + + align:start position:0% +V and certainly condition one by itself + + + align:start position:0% +V and certainly condition one by itself +isn't going to tell me any has no + + align:start position:0% +isn't going to tell me any has no + + + align:start position:0% +isn't going to tell me any has no +information programmed in it to tell me + + align:start position:0% +information programmed in it to tell me + + + align:start position:0% +information programmed in it to tell me +anything other than what it does to U1 + + align:start position:0% +anything other than what it does to U1 + + + align:start position:0% +anything other than what it does to U1 +up to un as a second input to my D + + align:start position:0% +up to un as a second input to my D + + + align:start position:0% +up to un as a second input to my D +machine for programming it I certainly + + align:start position:0% +machine for programming it I certainly + + + align:start position:0% +machine for programming it I certainly +know that given the N vectors if any two + + align:start position:0% +know that given the N vectors if any two + + + align:start position:0% +know that given the N vectors if any two +of the vectors happen to be equal then + + align:start position:0% +of the vectors happen to be equal then + + + align:start position:0% +of the vectors happen to be equal then +those vectors are linearly dependent + + align:start position:0% +those vectors are linearly dependent + + + align:start position:0% +those vectors are linearly dependent +consequently I instruct my D machine + + align:start position:0% +consequently I instruct my D machine + + + align:start position:0% +consequently I instruct my D machine +that if the input is a set of vectors + + align:start position:0% +that if the input is a set of vectors + + + align:start position:0% +that if the input is a set of vectors +Alpha One up to alpha n and at least two + + align:start position:0% +Alpha One up to alpha n and at least two + + + align:start position:0% +Alpha One up to alpha n and at least two +of the alphas are equal and the way we + + align:start position:0% +of the alphas are equal and the way we + + + align:start position:0% +of the alphas are equal and the way we +say that mathematically is that Alpha I + + align:start position:0% +say that mathematically is that Alpha I + + + align:start position:0% +say that mathematically is that Alpha I +equals Alpha J for some I une equal to J + + align:start position:0% +equals Alpha J for some I une equal to J + + + align:start position:0% +equals Alpha J for some I une equal to J +that if two of the vectors in the set + + align:start position:0% +that if two of the vectors in the set + + + align:start position:0% +that if two of the vectors in the set +are equal we tell the machine to grind + + align:start position:0% +are equal we tell the machine to grind + + + align:start position:0% +are equal we tell the machine to grind +out zero as an output and by the way at + + align:start position:0% +out zero as an output and by the way at + + + align:start position:0% +out zero as an output and by the way at +this stage we should be very careful to + + align:start position:0% +this stage we should be very careful to + + + align:start position:0% +this stage we should be very careful to +recognize that this is not the only way + + align:start position:0% +recognize that this is not the only way + + + align:start position:0% +recognize that this is not the only way +in which a set of vectors can be + + align:start position:0% +in which a set of vectors can be + + + align:start position:0% +in which a set of vectors can be +linearly dependent there are many ways + + align:start position:0% +linearly dependent there are many ways + + + align:start position:0% +linearly dependent there are many ways +in which a set of vectors can be + + align:start position:0% +in which a set of vectors can be + + + align:start position:0% +in which a set of vectors can be +linearly dependent even if no two of the + + align:start position:0% +linearly dependent even if no two of the + + + align:start position:0% +linearly dependent even if no two of the +vectors are equal so consequently given + + align:start position:0% +vectors are equal so consequently given + + + align:start position:0% +vectors are equal so consequently given +a linearly dependent set of vectors in + + align:start position:0% +a linearly dependent set of vectors in + + + align:start position:0% +a linearly dependent set of vectors in +which no two are equal notice that + + align:start position:0% +which no two are equal notice that + + + align:start position:0% +which no two are equal notice that +condition two here will not work or do + + align:start position:0% +condition two here will not work or do + + + align:start position:0% +condition two here will not work or do +anything for me so all I have done by + + align:start position:0% +anything for me so all I have done by + + + align:start position:0% +anything for me so all I have done by +conditions one and two + + align:start position:0% +conditions one and two + + + align:start position:0% +conditions one and two +is I have endowed my D machine with two + + align:start position:0% +is I have endowed my D machine with two + + + align:start position:0% +is I have endowed my D machine with two +standards one particular case in which + + align:start position:0% +standards one particular case in which + + + align:start position:0% +standards one particular case in which +the output of the D machine will be the + + align:start position:0% +the output of the D machine will be the + + + align:start position:0% +the output of the D machine will be the +number one and a particular situation in + + align:start position:0% +number one and a particular situation in + + + align:start position:0% +number one and a particular situation in +which the output of the D machine will + + align:start position:0% +which the output of the D machine will + + + align:start position:0% +which the output of the D machine will +be zero but I have not solved the + + align:start position:0% +be zero but I have not solved the + + + align:start position:0% +be zero but I have not solved the +problem that I wanted so far namely to + + align:start position:0% +problem that I wanted so far namely to + + + align:start position:0% +problem that I wanted so far namely to +make sure that D grinds out zero if and + + align:start position:0% +make sure that D grinds out zero if and + + + align:start position:0% +make sure that D grinds out zero if and +only if the set of n vectors are + + align:start position:0% +only if the set of n vectors are + + + align:start position:0% +only if the set of n vectors are +linearly dependent let me now in Dow d + + align:start position:0% +linearly dependent let me now in Dow d + + + align:start position:0% +linearly dependent let me now in Dow d +with a third property it is a property + + align:start position:0% +with a third property it is a property + + + align:start position:0% +with a third property it is a property +that will suggest linearity to you and + + align:start position:0% +that will suggest linearity to you and + + + align:start position:0% +that will suggest linearity to you and +it's one which is amazingly powerful and + + align:start position:0% +it's one which is amazingly powerful and + + + align:start position:0% +it's one which is amazingly powerful and +what I mean by amazingly powerful + + align:start position:0% +what I mean by amazingly powerful + + + align:start position:0% +what I mean by amazingly powerful +hopefully will become clear in a few + + align:start position:0% +hopefully will become clear in a few + + + align:start position:0% +hopefully will become clear in a few +moments but the third property is this + + align:start position:0% +moments but the third property is this + + + align:start position:0% +moments but the third property is this +and rather than work with endles here to + + align:start position:0% +and rather than work with endles here to + + + align:start position:0% +and rather than work with endles here to +make things easier to read let me just + + align:start position:0% +make things easier to read let me just + + + align:start position:0% +make things easier to read let me just +take a three Tuple over here suppose I + + align:start position:0% +take a three Tuple over here suppose I + + + align:start position:0% +take a three Tuple over here suppose I +have a three-dimensional Vector space + + align:start position:0% +have a three-dimensional Vector space + + + align:start position:0% +have a three-dimensional Vector space +and I pick three vectors in that space + + align:start position:0% +and I pick three vectors in that space + + + align:start position:0% +and I pick three vectors in that space +suppose one of those vectors the way + + align:start position:0% +suppose one of those vectors the way + + + align:start position:0% +suppose one of those vectors the way +I've written it here it happens to be + + align:start position:0% +I've written it here it happens to be + + + align:start position:0% +I've written it here it happens to be +the second Vector suppose one of those + + align:start position:0% +the second Vector suppose one of those + + + align:start position:0% +the second Vector suppose one of those +vectors is itself written as the sum of + + align:start position:0% +vectors is itself written as the sum of + + + align:start position:0% +vectors is itself written as the sum of +two other vectors in the space then I + + align:start position:0% +two other vectors in the space then I + + + align:start position:0% +two other vectors in the space then I +tell the D machine to compute this as + + align:start position:0% +tell the D machine to compute this as + + + align:start position:0% +tell the D machine to compute this as +follows linearize this in other words + + align:start position:0% +follows linearize this in other words + + + align:start position:0% +follows linearize this in other words +compute this as if it were the sum of + + align:start position:0% +compute this as if it were the sum of + + + align:start position:0% +compute this as if it were the sum of +two separate determinants one of which + + align:start position:0% +two separate determinants one of which + + + align:start position:0% +two separate determinants one of which +had the Alpha 2 missing and the other of + + align:start position:0% +had the Alpha 2 missing and the other of + + + align:start position:0% +had the Alpha 2 missing and the other of +which had the beta 2 missing in other + + align:start position:0% +which had the beta 2 missing in other + + + align:start position:0% +which had the beta 2 missing in other +words what I do is is I endow the + + align:start position:0% +words what I do is is I endow the + + + align:start position:0% +words what I do is is I endow the +machine with the property that D of + + align:start position:0% +machine with the property that D of + + + align:start position:0% +machine with the property that D of +alpha 1 comma Alpha 2 + beta 2 comma + + align:start position:0% +alpha 1 comma Alpha 2 + beta 2 comma + + + align:start position:0% +alpha 1 comma Alpha 2 + beta 2 comma +Alpha 3 will be D of alpha 1 Alpha 2 + + align:start position:0% +Alpha 3 will be D of alpha 1 Alpha 2 + + + align:start position:0% +Alpha 3 will be D of alpha 1 Alpha 2 +Alpha 3 plus d of alpha 1 beta 2 Alpha + + align:start position:0% +Alpha 3 plus d of alpha 1 beta 2 Alpha + + + align:start position:0% +Alpha 3 plus d of alpha 1 beta 2 Alpha + + align:start position:0% + + + align:start position:0% +okay and thirdly well thirdly I I don't + + align:start position:0% +okay and thirdly well thirdly I I don't + + + align:start position:0% +okay and thirdly well thirdly I I don't +mean thirdly I mean the other linear + + align:start position:0% +mean thirdly I mean the other linear + + + align:start position:0% +mean thirdly I mean the other linear +property if one of the input vectors is + + align:start position:0% +property if one of the input vectors is + + + align:start position:0% +property if one of the input vectors is +multiplied by a scalar I can Factor the + + align:start position:0% +multiplied by a scalar I can Factor the + + + align:start position:0% +multiplied by a scalar I can Factor the +Scala out in other words if the if the + + align:start position:0% +Scala out in other words if the if the + + + align:start position:0% +Scala out in other words if the if the +three vectors that are being tested in + + align:start position:0% +three vectors that are being tested in + + + align:start position:0% +three vectors that are being tested in +my three-dimensional space have the form + + align:start position:0% +my three-dimensional space have the form + + + align:start position:0% +my three-dimensional space have the form +alpha 1 C Alpha 2 and Alpha 3 D of alpha + + align:start position:0% +alpha 1 C Alpha 2 and Alpha 3 D of alpha + + + align:start position:0% +alpha 1 C Alpha 2 and Alpha 3 D of alpha +1 comma C Alpha 2 comma Alpha 3 will be + + align:start position:0% +1 comma C Alpha 2 comma Alpha 3 will be + + + align:start position:0% +1 comma C Alpha 2 comma Alpha 3 will be +C Factor the C out C * D of alpha 1 + + align:start position:0% +C Factor the C out C * D of alpha 1 + + + align:start position:0% +C Factor the C out C * D of alpha 1 +Alpha 2 Alpha 3 and it's extremely + + align:start position:0% +Alpha 2 Alpha 3 and it's extremely + + + align:start position:0% +Alpha 2 Alpha 3 and it's extremely +important to notice that the C does not + + align:start position:0% +important to notice that the C does not + + + align:start position:0% +important to notice that the C does not +have to be a Scala multiple of all three + + align:start position:0% +have to be a Scala multiple of all three + + + align:start position:0% +have to be a Scala multiple of all three +vectors in the input notice that the + + align:start position:0% +vectors in the input notice that the + + + align:start position:0% +vectors in the input notice that the +fact that the C was multiplying one of + + align:start position:0% +fact that the C was multiplying one of + + + align:start position:0% +fact that the C was multiplying one of +the vectors is enough to factor the C + + align:start position:0% +the vectors is enough to factor the C + + + align:start position:0% +the vectors is enough to factor the C +out without belaboring this point all I + + align:start position:0% +out without belaboring this point all I + + + align:start position:0% +out without belaboring this point all I +want to say was that if the C were + + align:start position:0% +want to say was that if the C were + + + align:start position:0% +want to say was that if the C were +multiplying each of the alphas in other + + align:start position:0% +multiplying each of the alphas in other + + + align:start position:0% +multiplying each of the alphas in other +words If This Were D of C alpha 1 comma + + align:start position:0% +words If This Were D of C alpha 1 comma + + + align:start position:0% +words If This Were D of C alpha 1 comma +C Alpha 2 comma C Alpha 3 this would + + align:start position:0% +C Alpha 2 comma C Alpha 3 this would + + + align:start position:0% +C Alpha 2 comma C Alpha 3 this would +equal C cubed d alpha 1 Alpha 2 Alpha 3 + + align:start position:0% +equal C cubed d alpha 1 Alpha 2 Alpha 3 + + + align:start position:0% +equal C cubed d alpha 1 Alpha 2 Alpha 3 +because we would factor out a c each + + align:start position:0% +because we would factor out a c each + + + align:start position:0% +because we would factor out a c each +time one for each Vector but let me + + align:start position:0% +time one for each Vector but let me + + + align:start position:0% +time one for each Vector but let me +illustrate this in terms of a 2x2 + + align:start position:0% +illustrate this in terms of a 2x2 + + + align:start position:0% +illustrate this in terms of a 2x2 +uh a two-dimensional example for you + + align:start position:0% +uh a two-dimensional example for you + + + align:start position:0% +uh a two-dimensional example for you +suppose I'm dealing in two-dimensional + + align:start position:0% +suppose I'm dealing in two-dimensional + + + align:start position:0% +suppose I'm dealing in two-dimensional +space and I'm dealing with respect to a + + align:start position:0% +space and I'm dealing with respect to a + + + align:start position:0% +space and I'm dealing with respect to a +particular basis U1 and U2 and let's + + align:start position:0% +particular basis U1 and U2 and let's + + + align:start position:0% +particular basis U1 and U2 and let's +suppose that relative to that basis U1 + + align:start position:0% +suppose that relative to that basis U1 + + + align:start position:0% +suppose that relative to that basis U1 +and U2 alpha 1 is the vector 3 comma 1 + + align:start position:0% +and U2 alpha 1 is the vector 3 comma 1 + + + align:start position:0% +and U2 alpha 1 is the vector 3 comma 1 +beta 1 is the vector 6 comma 7 and beta + + align:start position:0% +beta 1 is the vector 6 comma 7 and beta + + + align:start position:0% +beta 1 is the vector 6 comma 7 and beta +2 is the vector 4 comma 5 let's use the + + align:start position:0% +2 is the vector 4 comma 5 let's use the + + + align:start position:0% +2 is the vector 4 comma 5 let's use the +let's recall the fact that one way or + + align:start position:0% +let's recall the fact that one way or + + + align:start position:0% +let's recall the fact that one way or +another we already know how to expand + + align:start position:0% +another we already know how to expand + + + align:start position:0% +another we already know how to expand +two by two determinants even though we + + align:start position:0% +two by two determinants even though we + + + align:start position:0% +two by two determinants even though we +may not know rigorously why the rules + + align:start position:0% +may not know rigorously why the rules + + + align:start position:0% +may not know rigorously why the rules +were chosen the idea is what would alpha + + align:start position:0% +were chosen the idea is what would alpha + + + align:start position:0% +were chosen the idea is what would alpha +1 plus beta 1 be it would be the two + + align:start position:0% +1 plus beta 1 be it would be the two + + + align:start position:0% +1 plus beta 1 be it would be the two +tppo whose first entry was 3 + 6 and + + align:start position:0% +tppo whose first entry was 3 + 6 and + + + align:start position:0% +tppo whose first entry was 3 + 6 and +whose second entry was 1 + 7 in other + + align:start position:0% +whose second entry was 1 + 7 in other + + + align:start position:0% +whose second entry was 1 + 7 in other +words the first row of the determinant + + align:start position:0% +words the first row of the determinant + + + align:start position:0% +words the first row of the determinant +that I'm going to be talking about has + + align:start position:0% +that I'm going to be talking about has + + + align:start position:0% +that I'm going to be talking about has +as its entries 3 + 6 and 1 + 7 beta 2 + + align:start position:0% +as its entries 3 + 6 and 1 + 7 beta 2 + + + align:start position:0% +as its entries 3 + 6 and 1 + 7 beta 2 +which will make up the second row of my + + align:start position:0% +which will make up the second row of my + + + align:start position:0% +which will make up the second row of my +determinant has as its components four + + align:start position:0% +determinant has as its components four + + + align:start position:0% +determinant has as its components four +and five so the second row of my + + align:start position:0% +and five so the second row of my + + + align:start position:0% +and five so the second row of my +determinant is 4 five and using the + + align:start position:0% +determinant is 4 five and using the + + + align:start position:0% +determinant is 4 five and using the +usual rule for multiplying determinance + + align:start position:0% +usual rule for multiplying determinance + + + align:start position:0% +usual rule for multiplying determinance +this is 5 * 9 - 4 * 8 which is 13 and by + + align:start position:0% +this is 5 * 9 - 4 * 8 which is 13 and by + + + align:start position:0% +this is 5 * 9 - 4 * 8 which is 13 and by +the way just to refresh your memories + + align:start position:0% +the way just to refresh your memories + + + align:start position:0% +the way just to refresh your memories +here what have I computed in terms of my + + align:start position:0% +here what have I computed in terms of my + + + align:start position:0% +here what have I computed in terms of my +D language and the alpha 1 Alpha 2 and + + align:start position:0% +D language and the alpha 1 Alpha 2 and + + + align:start position:0% +D language and the alpha 1 Alpha 2 and +beta 2 is used here this is D of alpha 1 + + align:start position:0% +beta 2 is used here this is D of alpha 1 + + + align:start position:0% +beta 2 is used here this is D of alpha 1 +plus beta 1 comma beta 2 all right on + + align:start position:0% +plus beta 1 comma beta 2 all right on + + + align:start position:0% +plus beta 1 comma beta 2 all right on +the other hand what would D of alpha 1 + + align:start position:0% +the other hand what would D of alpha 1 + + + align:start position:0% +the other hand what would D of alpha 1 +beta 2 be D of alpha 1 beta 2 would be + + align:start position:0% +beta 2 be D of alpha 1 beta 2 would be + + + align:start position:0% +beta 2 be D of alpha 1 beta 2 would be +the 2x two determinant whose first row + + align:start position:0% +the 2x two determinant whose first row + + + align:start position:0% +the 2x two determinant whose first row +was 31 and whose second row was + + align:start position:0% +was 31 and whose second row was + + + align:start position:0% +was 31 and whose second row was +45 D of alpha 1 beta 2 would be the + + align:start position:0% +45 D of alpha 1 beta 2 would be the + + + align:start position:0% +45 D of alpha 1 beta 2 would be the +determinant + + align:start position:0% +determinant + + + align:start position:0% +determinant +whose first row I'm sorry D of beta 1 + + align:start position:0% +whose first row I'm sorry D of beta 1 + + + align:start position:0% +whose first row I'm sorry D of beta 1 +comma beta 2 would be the determinant + + align:start position:0% +comma beta 2 would be the determinant + + + align:start position:0% +comma beta 2 would be the determinant +whose first row was 6 comma 67 and whose + + align:start position:0% +whose first row was 6 comma 67 and whose + + + align:start position:0% +whose first row was 6 comma 67 and whose +second row was 45 in other words these + + align:start position:0% +second row was 45 in other words these + + + align:start position:0% +second row was 45 in other words these +matrices here what is this again this is + + align:start position:0% +matrices here what is this again this is + + + align:start position:0% +matrices here what is this again this is +D of alpha 1 beta + + align:start position:0% +D of alpha 1 beta + + + align:start position:0% +D of alpha 1 beta +2 and this one + + align:start position:0% +2 and this one + + + align:start position:0% +2 and this one +here is D of beta 1 beta 2 and notice + + align:start position:0% +here is D of beta 1 beta 2 and notice + + + align:start position:0% +here is D of beta 1 beta 2 and notice +that this determinant by the traditional + + align:start position:0% +that this determinant by the traditional + + + align:start position:0% +that this determinant by the traditional +way of expanding is 11 this determinant + + align:start position:0% +way of expanding is 11 this determinant + + + align:start position:0% +way of expanding is 11 this determinant +is 30 - 28 which is 2 11 + 2 is 13 and + + align:start position:0% +is 30 - 28 which is 2 11 + 2 is 13 and + + + align:start position:0% +is 30 - 28 which is 2 11 + 2 is 13 and +we see that at least in this case D of + + align:start position:0% +we see that at least in this case D of + + + align:start position:0% +we see that at least in this case D of +alpha 1 + beta 1 comma beta 2 is the + + align:start position:0% +alpha 1 + beta 1 comma beta 2 is the + + + align:start position:0% +alpha 1 + beta 1 comma beta 2 is the +same as D of alpha 1 comma beta 2 plus d + + align:start position:0% +same as D of alpha 1 comma beta 2 plus d + + + align:start position:0% +same as D of alpha 1 comma beta 2 plus d +of beta 1 comma beta 2 so at least uh + + align:start position:0% +of beta 1 comma beta 2 so at least uh + + + align:start position:0% +of beta 1 comma beta 2 so at least uh +the first part of property 3 is obeyed + + align:start position:0% +the first part of property 3 is obeyed + + + align:start position:0% +the first part of property 3 is obeyed +in this particular example and to show + + align:start position:0% +in this particular example and to show + + + align:start position:0% +in this particular example and to show +what the second property is let's + + align:start position:0% +what the second property is let's + + + align:start position:0% +what the second property is let's +suppose Alpha 1 now I pick a new Alpha 1 + + align:start position:0% +suppose Alpha 1 now I pick a new Alpha 1 + + + align:start position:0% +suppose Alpha 1 now I pick a new Alpha 1 +we'll call that 2 comma 6 suppose Alpha + + align:start position:0% +we'll call that 2 comma 6 suppose Alpha + + + align:start position:0% +we'll call that 2 comma 6 suppose Alpha +2 is 3 comma 4 then the determinant of + + align:start position:0% +2 is 3 comma 4 then the determinant of + + + align:start position:0% +2 is 3 comma 4 then the determinant of +alpha 1 and Alpha 2 would be what 26 34 + + align:start position:0% +alpha 1 and Alpha 2 would be what 26 34 + + + align:start position:0% +alpha 1 and Alpha 2 would be what 26 34 +right and that's what 8 - 18 which is - + + align:start position:0% +right and that's what 8 - 18 which is - + + + align:start position:0% +right and that's what 8 - 18 which is - +10 on the other hand notice that a + + align:start position:0% +10 on the other hand notice that a + + + align:start position:0% +10 on the other hand notice that a +common that this Vector here could have + + align:start position:0% +common that this Vector here could have + + + align:start position:0% +common that this Vector here could have +been written as twice one comma three I + + align:start position:0% +been written as twice one comma three I + + + align:start position:0% +been written as twice one comma three I +can therefore factor out the two see + + align:start position:0% +can therefore factor out the two see + + + align:start position:0% +can therefore factor out the two see +notice this very carefully notice that + + align:start position:0% +notice this very carefully notice that + + + align:start position:0% +notice this very carefully notice that +the alphas which are written in a row + + align:start position:0% +the alphas which are written in a row + + + align:start position:0% +the alphas which are written in a row +here one row this way each Alpha forms a + + align:start position:0% +here one row this way each Alpha forms a + + + align:start position:0% +here one row this way each Alpha forms a +row when I I use the Matrix + + align:start position:0% +row when I I use the Matrix + + + align:start position:0% +row when I I use the Matrix +interpretation so what I'm saying is + + align:start position:0% +interpretation so what I'm saying is + + + align:start position:0% +interpretation so what I'm saying is +that 2 comma 6 is + + align:start position:0% +that 2 comma 6 is + + + align:start position:0% +that 2 comma 6 is +one vector it's a twole with respect to + + align:start position:0% +one vector it's a twole with respect to + + + align:start position:0% +one vector it's a twole with respect to +the bases U1 and U2 all I'm saying is + + align:start position:0% +the bases U1 and U2 all I'm saying is + + + align:start position:0% +the bases U1 and U2 all I'm saying is +factor out the two from the first row + + align:start position:0% +factor out the two from the first row + + + align:start position:0% +factor out the two from the first row +from the first Vector that leaves me + + align:start position:0% +from the first Vector that leaves me + + + align:start position:0% +from the first Vector that leaves me +with two outside 1 3 3 4 inside and + + align:start position:0% +with two outside 1 3 3 4 inside and + + + align:start position:0% +with two outside 1 3 3 4 inside and +notice that 4 * 4 - 9 is -5 * 2 is also + + align:start position:0% +notice that 4 * 4 - 9 is -5 * 2 is also + + + align:start position:0% +notice that 4 * 4 - 9 is -5 * 2 is also +-10 notice that these indeed are equal + + align:start position:0% +-10 notice that these indeed are equal + + + align:start position:0% +-10 notice that these indeed are equal +and not no that I could factor out the + + align:start position:0% +and not no that I could factor out the + + + align:start position:0% +and not no that I could factor out the +two simply by virtue of the fact that it + + align:start position:0% +two simply by virtue of the fact that it + + + align:start position:0% +two simply by virtue of the fact that it +was a common factor in one row it did + + align:start position:0% +was a common factor in one row it did + + + align:start position:0% +was a common factor in one row it did +not have to be a common factor in both + + align:start position:0% +not have to be a common factor in both + + + align:start position:0% +not have to be a common factor in both +rows in fact if it had been a common + + align:start position:0% +rows in fact if it had been a common + + + align:start position:0% +rows in fact if it had been a common +factor in both rows I would have had to + + align:start position:0% +factor in both rows I would have had to + + + align:start position:0% +factor in both rows I would have had to +factor out at two twice in other words a + + align:start position:0% +factor out at two twice in other words a + + + align:start position:0% +factor out at two twice in other words a +four over here now I can go on with + + align:start position:0% +four over here now I can go on with + + + align:start position:0% +four over here now I can go on with +things like this but again I want to + + align:start position:0% +things like this but again I want to + + + align:start position:0% +things like this but again I want to +stress the overview and the key point is + + align:start position:0% +stress the overview and the key point is + + + align:start position:0% +stress the overview and the key point is +that these three simple properties which + + align:start position:0% +that these three simple properties which + + + align:start position:0% +that these three simple properties which +I've just called simply one two and + + align:start position:0% +I've just called simply one two and + + + align:start position:0% +I've just called simply one two and +three those three properties that I've + + align:start position:0% +three those three properties that I've + + + align:start position:0% +three those three properties that I've +programmed the D machine with are enough + + align:start position:0% +programmed the D machine with are enough + + + align:start position:0% +programmed the D machine with are enough +to completely determine D in other words + + align:start position:0% +to completely determine D in other words + + + align:start position:0% +to completely determine D in other words +if I want to be dramatic over here the + + align:start position:0% +if I want to be dramatic over here the + + + align:start position:0% +if I want to be dramatic over here the +key point is that 1 two and three + + align:start position:0% +key point is that 1 two and three + + + align:start position:0% +key point is that 1 two and three +completely determine D I'll put an + + align:start position:0% +completely determine D I'll put an + + + align:start position:0% +completely determine D I'll put an +exclamation point down there because + + align:start position:0% +exclamation point down there because + + + align:start position:0% +exclamation point down there because +what I claim is that once these three + + align:start position:0% +what I claim is that once these three + + + align:start position:0% +what I claim is that once these three +properties are obeyed there is no + + align:start position:0% +properties are obeyed there is no + + + align:start position:0% +properties are obeyed there is no +possible way for D to behave other than + + align:start position:0% +possible way for D to behave other than + + + align:start position:0% +possible way for D to behave other than +in a very unique well-defined way that + + align:start position:0% +in a very unique well-defined way that + + + align:start position:0% +in a very unique well-defined way that +now has a perfectly well- defined + + align:start position:0% +now has a perfectly well- defined + + + align:start position:0% +now has a perfectly well- defined +structure let me give you some examples + + align:start position:0% +structure let me give you some examples + + + align:start position:0% +structure let me give you some examples +of that structure I'll just prove a + + align:start position:0% +of that structure I'll just prove a + + + align:start position:0% +of that structure I'll just prove a +couple of theorems I'll prove them in + + align:start position:0% +couple of theorems I'll prove them in + + + align:start position:0% +couple of theorems I'll prove them in +two dimensional space leaving it for the + + align:start position:0% +two dimensional space leaving it for the + + + align:start position:0% +two dimensional space leaving it for the +exercises to work in higher dimensional + + align:start position:0% +exercises to work in higher dimensional + + + align:start position:0% +exercises to work in higher dimensional +space but this doesn't get too cluttered + + align:start position:0% +space but this doesn't get too cluttered + + + align:start position:0% +space but this doesn't get too cluttered +first of all what I claim is that the D + + align:start position:0% +first of all what I claim is that the D + + + align:start position:0% +first of all what I claim is that the D +machine is so finicky that if you + + align:start position:0% +machine is so finicky that if you + + + align:start position:0% +machine is so finicky that if you +interchange the order in which the two + + align:start position:0% +interchange the order in which the two + + + align:start position:0% +interchange the order in which the two +vectors are + + align:start position:0% +vectors are + + + align:start position:0% +vectors are +given you change the sign of the + + align:start position:0% +given you change the sign of the + + + align:start position:0% +given you change the sign of the +output okay and in other words D of + + align:start position:0% +output okay and in other words D of + + + align:start position:0% +output okay and in other words D of +alpha 1 Alpha 2 in that order is the + + align:start position:0% +alpha 1 Alpha 2 in that order is the + + + align:start position:0% +alpha 1 Alpha 2 in that order is the +negative of D of Alpha 2 alpha 1 and the + + align:start position:0% +negative of D of Alpha 2 alpha 1 and the + + + align:start position:0% +negative of D of Alpha 2 alpha 1 and the +proof again follows very nicely in terms + + align:start position:0% +proof again follows very nicely in terms + + + align:start position:0% +proof again follows very nicely in terms +of our game structure the gimmick to + + align:start position:0% +of our game structure the gimmick to + + + align:start position:0% +of our game structure the gimmick to +begin with is that we must be clever + + align:start position:0% +begin with is that we must be clever + + + align:start position:0% +begin with is that we must be clever +enough to decide that we'll compute the + + align:start position:0% +enough to decide that we'll compute the + + + align:start position:0% +enough to decide that we'll compute the +determinant of alpha 1 + Alpha 2 comma + + align:start position:0% +determinant of alpha 1 + Alpha 2 comma + + + align:start position:0% +determinant of alpha 1 + Alpha 2 comma +alpha 1+ alpha 2 on the One Hand by our + + align:start position:0% +alpha 1+ alpha 2 on the One Hand by our + + + align:start position:0% +alpha 1+ alpha 2 on the One Hand by our +second property since two of the vectors + + align:start position:0% +second property since two of the vectors + + + align:start position:0% +second property since two of the vectors +making up the set being tested are equal + + align:start position:0% +making up the set being tested are equal + + + align:start position:0% +making up the set being tested are equal +it means that that determinant must be + + align:start position:0% +it means that that determinant must be + + + align:start position:0% +it means that that determinant must be +zero on the other hand by property three + + align:start position:0% +zero on the other hand by property three + + + align:start position:0% +zero on the other hand by property three +by linearity splitting this up as two + + align:start position:0% +by linearity splitting this up as two + + + align:start position:0% +by linearity splitting this up as two +terms notice that this is D of alpha 1 + + align:start position:0% +terms notice that this is D of alpha 1 + + + align:start position:0% +terms notice that this is D of alpha 1 +comma alpha 1 + Alpha 2 plus d of Alpha + + align:start position:0% +comma alpha 1 + Alpha 2 plus d of Alpha + + + align:start position:0% +comma alpha 1 + Alpha 2 plus d of Alpha +2 comma alpha 1 + Alpha 2 in other words + + align:start position:0% +2 comma alpha 1 + Alpha 2 in other words + + + align:start position:0% +2 comma alpha 1 + Alpha 2 in other words +this result here now in + + align:start position:0% +this result here now in + + + align:start position:0% +this result here now in +turn noticing that these form of sum I + + align:start position:0% +turn noticing that these form of sum I + + + align:start position:0% +turn noticing that these form of sum I +can rewrite this one as what D of alpha + + align:start position:0% +can rewrite this one as what D of alpha + + + align:start position:0% +can rewrite this one as what D of alpha +1 comma Alpha 1 plus d of alpha 1 comma + + align:start position:0% +1 comma Alpha 1 plus d of alpha 1 comma + + + align:start position:0% +1 comma Alpha 1 plus d of alpha 1 comma +Alpha 2 this one is D of Alpha 2 comma + + align:start position:0% +Alpha 2 this one is D of Alpha 2 comma + + + align:start position:0% +Alpha 2 this one is D of Alpha 2 comma +alpha 1 plus d of Alpha 2 comma Alpha 2 + + align:start position:0% +alpha 1 plus d of Alpha 2 comma Alpha 2 + + + align:start position:0% +alpha 1 plus d of Alpha 2 comma Alpha 2 +I've just written this whole thing out + + align:start position:0% +I've just written this whole thing out + + + align:start position:0% +I've just written this whole thing out +on this next line by Property 2 D of + + align:start position:0% +on this next line by Property 2 D of + + + align:start position:0% +on this next line by Property 2 D of +alpha 1 comma alpha 1 must be Zero D of + + align:start position:0% +alpha 1 comma alpha 1 must be Zero D of + + + align:start position:0% +alpha 1 comma alpha 1 must be Zero D of +Alpha 2 comma Alpha 2 must be zero + + align:start position:0% +Alpha 2 comma Alpha 2 must be zero + + + align:start position:0% +Alpha 2 comma Alpha 2 must be zero +because after all both you see two + + align:start position:0% +because after all both you see two + + + align:start position:0% +because after all both you see two +vectors are equal in + + align:start position:0% +vectors are equal in + + + align:start position:0% +vectors are equal in +this so what do I have left comparing + + align:start position:0% +this so what do I have left comparing + + + align:start position:0% +this so what do I have left comparing +this with this I have the D of alpha 1A + + align:start position:0% +this with this I have the D of alpha 1A + + + align:start position:0% +this with this I have the D of alpha 1A +Alpha 2 plus d of Alpha 2 comma alpha 1 + + align:start position:0% +Alpha 2 plus d of Alpha 2 comma alpha 1 + + + align:start position:0% +Alpha 2 plus d of Alpha 2 comma alpha 1 +is zero and that means that the number + + align:start position:0% +is zero and that means that the number + + + align:start position:0% +is zero and that means that the number +and keep that in mind the determinant is + + align:start position:0% +and keep that in mind the determinant is + + + align:start position:0% +and keep that in mind the determinant is +a number it Maps the N vectors into a + + align:start position:0% +a number it Maps the N vectors into a + + + align:start position:0% +a number it Maps the N vectors into a +number which is either zero or nonzero + + align:start position:0% +number which is either zero or nonzero + + + align:start position:0% +number which is either zero or nonzero +but the determinant of alpha 1 comma + + align:start position:0% +but the determinant of alpha 1 comma + + + align:start position:0% +but the determinant of alpha 1 comma +Alpha 2 therefore must be the negative + + align:start position:0% +Alpha 2 therefore must be the negative + + + align:start position:0% +Alpha 2 therefore must be the negative +of the determinant of Alpha 2 Alpha 1 + + align:start position:0% +of the determinant of Alpha 2 Alpha 1 + + + align:start position:0% +of the determinant of Alpha 2 Alpha 1 +because their sum is + + align:start position:0% +because their sum is + + + align:start position:0% +because their sum is +zero the second theorem and this is the + + align:start position:0% +zero the second theorem and this is the + + + align:start position:0% +zero the second theorem and this is the +one that relates determinants to + + align:start position:0% +one that relates determinants to + + + align:start position:0% +one that relates determinants to +matrices a very fantastic result + + align:start position:0% +matrices a very fantastic result + + + align:start position:0% +matrices a very fantastic result +one that has tremendous practical + + align:start position:0% +one that has tremendous practical + + + align:start position:0% +one that has tremendous practical +application that we'll also talk about + + align:start position:0% +application that we'll also talk about + + + align:start position:0% +application that we'll also talk about +later in the lecture and that is that if + + align:start position:0% +later in the lecture and that is that if + + + align:start position:0% +later in the lecture and that is that if +I take any one of my input vectors and + + align:start position:0% +I take any one of my input vectors and + + + align:start position:0% +I take any one of my input vectors and +replace it by itself plus a Scala + + align:start position:0% +replace it by itself plus a Scala + + + align:start position:0% +replace it by itself plus a Scala +multiple of + + align:start position:0% +multiple of + + + align:start position:0% +multiple of +another I do not change the determinant + + align:start position:0% +another I do not change the determinant + + + align:start position:0% +another I do not change the determinant +in other words for example if I replace + + align:start position:0% +in other words for example if I replace + + + align:start position:0% +in other words for example if I replace +alpha 1 by alpha 1 plus a Scala multiple + + align:start position:0% +alpha 1 by alpha 1 plus a Scala multiple + + + align:start position:0% +alpha 1 by alpha 1 plus a Scala multiple +of Alpha 2 and I leave Alpha 2 alone the + + align:start position:0% +of Alpha 2 and I leave Alpha 2 alone the + + + align:start position:0% +of Alpha 2 and I leave Alpha 2 alone the +the determinant of alpha 1 and Alpha 2 + + align:start position:0% +the determinant of alpha 1 and Alpha 2 + + + align:start position:0% +the determinant of alpha 1 and Alpha 2 +will be the same as the determinant of + + align:start position:0% +will be the same as the determinant of + + + align:start position:0% +will be the same as the determinant of +alpha 1 plus C Alpha 2 comma Alpha 2 and + + align:start position:0% +alpha 1 plus C Alpha 2 comma Alpha 2 and + + + align:start position:0% +alpha 1 plus C Alpha 2 comma Alpha 2 and +again the proof is very easy namely look + + align:start position:0% +again the proof is very easy namely look + + + align:start position:0% +again the proof is very easy namely look +at the expression D of alpha 1 plus C + + align:start position:0% +at the expression D of alpha 1 plus C + + + align:start position:0% +at the expression D of alpha 1 plus C +Alpha 2 comma Alpha 2 use the linearity + + align:start position:0% +Alpha 2 comma Alpha 2 use the linearity + + + align:start position:0% +Alpha 2 comma Alpha 2 use the linearity +property that this is D of this is D of + + align:start position:0% +property that this is D of this is D of + + + align:start position:0% +property that this is D of this is D of +alpha 1 comma Alpha 2 plus d of C Alpha + + align:start position:0% +alpha 1 comma Alpha 2 plus d of C Alpha + + + align:start position:0% +alpha 1 comma Alpha 2 plus d of C Alpha +2 comma Alpha + + align:start position:0% +2 comma Alpha + + + align:start position:0% +2 comma Alpha +2 then use the the second part of the + + align:start position:0% +2 then use the the second part of the + + + align:start position:0% +2 then use the the second part of the +linearity property that the constant + + align:start position:0% +linearity property that the constant + + + align:start position:0% +linearity property that the constant +Factor C can be taken outside here so + + align:start position:0% +Factor C can be taken outside here so + + + align:start position:0% +Factor C can be taken outside here so +this becomes D of alpha 1 Alpha 2 plus C + + align:start position:0% +this becomes D of alpha 1 Alpha 2 plus C + + + align:start position:0% +this becomes D of alpha 1 Alpha 2 plus C +* D of Alpha 2 comma Alpha 2 and notice + + align:start position:0% +* D of Alpha 2 comma Alpha 2 and notice + + + align:start position:0% +* D of Alpha 2 comma Alpha 2 and notice +that since Alpha 2 is repeated here this + + align:start position:0% +that since Alpha 2 is repeated here this + + + align:start position:0% +that since Alpha 2 is repeated here this +determinant is zero and consequently + + align:start position:0% +determinant is zero and consequently + + + align:start position:0% +determinant is zero and consequently +what we've proven is that this is equal + + align:start position:0% +what we've proven is that this is equal + + + align:start position:0% +what we've proven is that this is equal +to this now I've just proven those two + + align:start position:0% +to this now I've just proven those two + + + align:start position:0% +to this now I've just proven those two +theorems because that's about all I need + + align:start position:0% +theorems because that's about all I need + + + align:start position:0% +theorems because that's about all I need +let me show you now that if I had never + + align:start position:0% +let me show you now that if I had never + + + align:start position:0% +let me show you now that if I had never +seen that shortcut method of expanding a + + align:start position:0% +seen that shortcut method of expanding a + + + align:start position:0% +seen that shortcut method of expanding a +2X two determinant as learned in high + + align:start position:0% +2X two determinant as learned in high + + + align:start position:0% +2X two determinant as learned in high +school how these three properties + + align:start position:0% +school how these three properties + + + align:start position:0% +school how these three properties +uniquely determine what D has to mean in + + align:start position:0% +uniquely determine what D has to mean in + + + align:start position:0% +uniquely determine what D has to mean in +other words why I said that these three + + align:start position:0% +other words why I said that these three + + + align:start position:0% +other words why I said that these three +properties uniquely determined d as an + + align:start position:0% +properties uniquely determined d as an + + + align:start position:0% +properties uniquely determined d as an +example let me take a two-dimensional + + align:start position:0% +example let me take a two-dimensional + + + align:start position:0% +example let me take a two-dimensional +Vector space again let me pick U1 and U2 + + align:start position:0% +Vector space again let me pick U1 and U2 + + + align:start position:0% +Vector space again let me pick U1 and U2 +as a specific basis and that's important + + align:start position:0% +as a specific basis and that's important + + + align:start position:0% +as a specific basis and that's important +I've picked a specific basis U1 U2 now I + + align:start position:0% +I've picked a specific basis U1 U2 now I + + + align:start position:0% +I've picked a specific basis U1 U2 now I +pick any two vectors since V is a + + align:start position:0% +pick any two vectors since V is a + + + align:start position:0% +pick any two vectors since V is a +two-dimensional space I pick any two + + align:start position:0% +two-dimensional space I pick any two + + + align:start position:0% +two-dimensional space I pick any two +vectors Alpha 1 and Alpha 2 + + align:start position:0% +vectors Alpha 1 and Alpha 2 + + + align:start position:0% +vectors Alpha 1 and Alpha 2 +and because of this notation this means + + align:start position:0% +and because of this notation this means + + + align:start position:0% +and because of this notation this means +that alpha 1 and Alpha 2 are both linear + + align:start position:0% +that alpha 1 and Alpha 2 are both linear + + + align:start position:0% +that alpha 1 and Alpha 2 are both linear +combinations of U1 and U2 say alpha 1 is + + align:start position:0% +combinations of U1 and U2 say alpha 1 is + + + align:start position:0% +combinations of U1 and U2 say alpha 1 is +this and Alpha 2 is this therefore what + + align:start position:0% +this and Alpha 2 is this therefore what + + + align:start position:0% +this and Alpha 2 is this therefore what +is D of alpha 1 comma Alpha 2 well by + + align:start position:0% +is D of alpha 1 comma Alpha 2 well by + + + align:start position:0% +is D of alpha 1 comma Alpha 2 well by +direct substitution D of alpha 1 Alpha + + align:start position:0% +direct substitution D of alpha 1 Alpha + + + align:start position:0% +direct substitution D of alpha 1 Alpha +2 just replace alpha 1 by what it's + + align:start position:0% +2 just replace alpha 1 by what it's + + + align:start position:0% +2 just replace alpha 1 by what it's +equal to here Alpha 2 by what it's equal + + align:start position:0% +equal to here Alpha 2 by what it's equal + + + align:start position:0% +equal to here Alpha 2 by what it's equal +to here and we get that D of alpha 1 + + align:start position:0% +to here and we get that D of alpha 1 + + + align:start position:0% +to here and we get that D of alpha 1 +Alpha 2 is this expression + + align:start position:0% +Alpha 2 is this expression + + + align:start position:0% +Alpha 2 is this expression +now we use the linearity property we + + align:start position:0% +now we use the linearity property we + + + align:start position:0% +now we use the linearity property we +treat this as one number for the time + + align:start position:0% +treat this as one number for the time + + + align:start position:0% +treat this as one number for the time +being and split this up as a sum other + + align:start position:0% +being and split this up as a sum other + + + align:start position:0% +being and split this up as a sum other +words it's going to be D of this term + + align:start position:0% +words it's going to be D of this term + + + align:start position:0% +words it's going to be D of this term +comma this whole term plus d of this + + align:start position:0% +comma this whole term plus d of this + + + align:start position:0% +comma this whole term plus d of this +term comma this whole term in other + + align:start position:0% +term comma this whole term in other + + + align:start position:0% +term comma this whole term in other +words if I do that this breaks down to + + align:start position:0% +words if I do that this breaks down to + + + align:start position:0% +words if I do that this breaks down to +this now I notice that each of these two + + align:start position:0% +this now I notice that each of these two + + + align:start position:0% +this now I notice that each of these two +is a twole in which the second entry is + + align:start position:0% +is a twole in which the second entry is + + + align:start position:0% +is a twole in which the second entry is +a sum of two terms so I now split this + + align:start position:0% +a sum of two terms so I now split this + + + align:start position:0% +a sum of two terms so I now split this +up into what D of this comma this plus d + + align:start position:0% +up into what D of this comma this plus d + + + align:start position:0% +up into what D of this comma this plus d +of this comma This this term becomes D + + align:start position:0% +of this comma This this term becomes D + + + align:start position:0% +of this comma This this term becomes D +of this comma this term plus d of this + + align:start position:0% +of this comma this term plus d of this + + + align:start position:0% +of this comma this term plus d of this +comma this term and I hope it doesn't + + align:start position:0% +comma this term and I hope it doesn't + + + align:start position:0% +comma this term and I hope it doesn't +sound borish on my part to keep saying D + + align:start position:0% +sound borish on my part to keep saying D + + + align:start position:0% +sound borish on my part to keep saying D +of this comma this I prefer to say that + + align:start position:0% +of this comma this I prefer to say that + + + align:start position:0% +of this comma this I prefer to say that +for you so you can watch what I'm doing + + align:start position:0% +for you so you can watch what I'm doing + + + align:start position:0% +for you so you can watch what I'm doing +and then have you just be able + + align:start position:0% +and then have you just be able + + + align:start position:0% +and then have you just be able +afterwards to read what these things + + align:start position:0% +afterwards to read what these things + + + align:start position:0% +afterwards to read what these things +mean now when I'm down to here notice + + align:start position:0% +mean now when I'm down to here notice + + + align:start position:0% +mean now when I'm down to here notice +that by my second part of linearity I + + align:start position:0% +that by my second part of linearity I + + + align:start position:0% +that by my second part of linearity I +can factor out the a11 from here I can + + align:start position:0% +can factor out the a11 from here I can + + + align:start position:0% +can factor out the a11 from here I can +factor out the a21 because it's a common + + align:start position:0% +factor out the a21 because it's a common + + + align:start position:0% +factor out the a21 because it's a common +factor of this term in other words I can + + align:start position:0% +factor of this term in other words I can + + + align:start position:0% +factor of this term in other words I can +write this term as a11 a21 D of U1 comma + + align:start position:0% +write this term as a11 a21 D of U1 comma + + + align:start position:0% +write this term as a11 a21 D of U1 comma +U2 and again sparing you the details + + align:start position:0% +U2 and again sparing you the details + + + align:start position:0% +U2 and again sparing you the details +notice I can factor out an a11 A2 22 + + align:start position:0% +notice I can factor out an a11 A2 22 + + + align:start position:0% +notice I can factor out an a11 A2 22 +from this term I can factor out an a12 + + align:start position:0% +from this term I can factor out an a12 + + + align:start position:0% +from this term I can factor out an a12 +a21 from this term an a12 a22 from this + + align:start position:0% +a21 from this term an a12 a22 from this + + + align:start position:0% +a21 from this term an a12 a22 from this +term and that this now can be written in + + align:start position:0% +term and that this now can be written in + + + align:start position:0% +term and that this now can be written in +this particular way now what properties + + align:start position:0% +this particular way now what properties + + + align:start position:0% +this particular way now what properties +do I know that D is endowed with I know + + align:start position:0% +do I know that D is endowed with I know + + + align:start position:0% +do I know that D is endowed with I know +first of all that whenever D operates on + + align:start position:0% +first of all that whenever D operates on + + + align:start position:0% +first of all that whenever D operates on +a set of vectors where at least two of + + align:start position:0% +a set of vectors where at least two of + + + align:start position:0% +a set of vectors where at least two of +them are equal D must give zero as an + + align:start position:0% +them are equal D must give zero as an + + + align:start position:0% +them are equal D must give zero as an +output so D of U1 comma U1 is zero again + + align:start position:0% +output so D of U1 comma U1 is zero again + + + align:start position:0% +output so D of U1 comma U1 is zero again +U1 comma U2 is the particular basis with + + align:start position:0% +U1 comma U2 is the particular basis with + + + align:start position:0% +U1 comma U2 is the particular basis with +respect to which I Define V see + + align:start position:0% +respect to which I Define V see + + + align:start position:0% +respect to which I Define V see +therefore by property One D of U1 comma + + align:start position:0% +therefore by property One D of U1 comma + + + align:start position:0% +therefore by property One D of U1 comma +U2 must be + + align:start position:0% +U2 must be + + + align:start position:0% +U2 must be +one D of U2 comma U1 is just a the + + align:start position:0% +one D of U2 comma U1 is just a the + + + align:start position:0% +one D of U2 comma U1 is just a the +permuted order of U1 and U2 therefore by + + align:start position:0% +permuted order of U1 and U2 therefore by + + + align:start position:0% +permuted order of U1 and U2 therefore by +our first theorem that must be minus D + + align:start position:0% +our first theorem that must be minus D + + + align:start position:0% +our first theorem that must be minus D +of U1 U2 therefore it must be minus one + + align:start position:0% +of U1 U2 therefore it must be minus one + + + align:start position:0% +of U1 U2 therefore it must be minus one +and finally D of U2 comma U2 is zero and + + align:start position:0% +and finally D of U2 comma U2 is zero and + + + align:start position:0% +and finally D of U2 comma U2 is zero and +if I now collect everything that I have + + align:start position:0% +if I now collect everything that I have + + + align:start position:0% +if I now collect everything that I have +left here what do I have I have that D + + align:start position:0% +left here what do I have I have that D + + + align:start position:0% +left here what do I have I have that D +of alpha 1 comma Alpha + + align:start position:0% +of alpha 1 comma Alpha + + + align:start position:0% +of alpha 1 comma Alpha +2 is equal to what it's equal to a11 a22 + + align:start position:0% +2 is equal to what it's equal to a11 a22 + + + align:start position:0% +2 is equal to what it's equal to a11 a22 +C * 1 minus a12 a21 in other words this + + align:start position:0% +C * 1 minus a12 a21 in other words this + + + align:start position:0% +C * 1 minus a12 a21 in other words this +is the determinant of alpha 1 comma + + align:start position:0% +is the determinant of alpha 1 comma + + + align:start position:0% +is the determinant of alpha 1 comma +Alpha 2 and let me again put an + + align:start position:0% +Alpha 2 and let me again put an + + + align:start position:0% +Alpha 2 and let me again put an +exclamation point here because if you + + align:start position:0% +exclamation point here because if you + + + align:start position:0% +exclamation point here because if you +now go back to the high school way of + + align:start position:0% +now go back to the high school way of + + + align:start position:0% +now go back to the high school way of +computing this determinant remember how + + align:start position:0% +computing this determinant remember how + + + align:start position:0% +computing this determinant remember how +we did it what would we have obtained + + align:start position:0% +we did it what would we have obtained + + + align:start position:0% +we did it what would we have obtained +and again let me just come back to this + + align:start position:0% +and again let me just come back to this + + + align:start position:0% +and again let me just come back to this +board for a second here remember how you + + align:start position:0% +board for a second here remember how you + + + align:start position:0% +board for a second here remember how you +use the Matrix of coefficients to take + + align:start position:0% +use the Matrix of coefficients to take + + + align:start position:0% +use the Matrix of coefficients to take +the determinant would be What a11 a22 + + align:start position:0% +the determinant would be What a11 a22 + + + align:start position:0% +the determinant would be What a11 a22 +minus a12 + + align:start position:0% +minus a12 + + + align:start position:0% +minus a12 +a21 see again notice two things that + + align:start position:0% +a21 see again notice two things that + + + align:start position:0% +a21 see again notice two things that +happen here first of all I get the same + + align:start position:0% +happen here first of all I get the same + + + align:start position:0% +happen here first of all I get the same +answer as I would have got the + + align:start position:0% +answer as I would have got the + + + align:start position:0% +answer as I would have got the +traditional way and second just as a + + align:start position:0% +traditional way and second just as a + + + align:start position:0% +traditional way and second just as a +minor aside that I'll emphasize more + + align:start position:0% +minor aside that I'll emphasize more + + + align:start position:0% +minor aside that I'll emphasize more +later in the lecture and also in the + + align:start position:0% +later in the lecture and also in the + + + align:start position:0% +later in the lecture and also in the +exercises notice that you can begin to + + align:start position:0% +exercises notice that you can begin to + + + align:start position:0% +exercises notice that you can begin to +suspect that the actual value of the + + align:start position:0% +suspect that the actual value of the + + + align:start position:0% +suspect that the actual value of the +determinant of alpha 1 and Alpha 2 + + align:start position:0% +determinant of alpha 1 and Alpha 2 + + + align:start position:0% +determinant of alpha 1 and Alpha 2 +should depend on what basis was chosen + + align:start position:0% +should depend on what basis was chosen + + + align:start position:0% +should depend on what basis was chosen +because relative to a different basis + + align:start position:0% +because relative to a different basis + + + align:start position:0% +because relative to a different basis +notice that the coefficients might very + + align:start position:0% +notice that the coefficients might very + + + align:start position:0% +notice that the coefficients might very +well be different for Alpha 1 and Alpha + + align:start position:0% +well be different for Alpha 1 and Alpha + + + align:start position:0% +well be different for Alpha 1 and Alpha +2 but I don't want to mention that right + + align:start position:0% +2 but I don't want to mention that right + + + align:start position:0% +2 but I don't want to mention that right +now I think what as I say what the + + align:start position:0% +now I think what as I say what the + + + align:start position:0% +now I think what as I say what the +amazing result is that what I meant by + + align:start position:0% +amazing result is that what I meant by + + + align:start position:0% +amazing result is that what I meant by +saying that these three properties + + align:start position:0% +saying that these three properties + + + align:start position:0% +saying that these three properties +completely determined D is the fact that + + align:start position:0% +completely determined D is the fact that + + + align:start position:0% +completely determined D is the fact that +with these three properties the turned + + align:start position:0% +with these three properties the turned + + + align:start position:0% +with these three properties the turned +out that the high school + + align:start position:0% +out that the high school + + + align:start position:0% +out that the high school +definition was Ironclad meaning there + + align:start position:0% +definition was Ironclad meaning there + + + align:start position:0% +definition was Ironclad meaning there +was no other possible way to define what + + align:start position:0% +was no other possible way to define what + + + align:start position:0% +was no other possible way to define what +the determinant should be if you wanted + + align:start position:0% +the determinant should be if you wanted + + + align:start position:0% +the determinant should be if you wanted +these three properties to be obeyed by + + align:start position:0% +these three properties to be obeyed by + + + align:start position:0% +these three properties to be obeyed by +the way as some quick checks notice that + + align:start position:0% +the way as some quick checks notice that + + + align:start position:0% +the way as some quick checks notice that +relative to the basis U1 U2 U1 can be + + align:start position:0% +relative to the basis U1 U2 U1 can be + + + align:start position:0% +relative to the basis U1 U2 U1 can be +written this way U2 can be written this + + align:start position:0% +written this way U2 can be written this + + + align:start position:0% +written this way U2 can be written this +way we know that D of U1 U2 should be + + align:start position:0% +way we know that D of U1 U2 should be + + + align:start position:0% +way we know that D of U1 U2 should be +one and using the oldfashioned way for + + align:start position:0% +one and using the oldfashioned way for + + + align:start position:0% +one and using the oldfashioned way for +checking this what would the deter B it + + align:start position:0% +checking this what would the deter B it + + + align:start position:0% +checking this what would the deter B it +would be 1 * 1 - 0 * 0 which is 1 + + align:start position:0% +would be 1 * 1 - 0 * 0 which is 1 + + + align:start position:0% +would be 1 * 1 - 0 * 0 which is 1 +secondly we also know that property two + + align:start position:0% +secondly we also know that property two + + + align:start position:0% +secondly we also know that property two +should yield zero as a determinant if + + align:start position:0% +should yield zero as a determinant if + + + align:start position:0% +should yield zero as a determinant if +the two vectors that were making up the + + align:start position:0% +the two vectors that were making up the + + + align:start position:0% +the two vectors that were making up the +input were equal let's call the vectors + + align:start position:0% +input were equal let's call the vectors + + + align:start position:0% +input were equal let's call the vectors +Au U1 bu U2 so the 2x two determinant I + + align:start position:0% +Au U1 bu U2 so the 2x two determinant I + + + align:start position:0% +Au U1 bu U2 so the 2x two determinant I +would get in this case is a b a b and if + + align:start position:0% +would get in this case is a b a b and if + + + align:start position:0% +would get in this case is a b a b and if +I expand that determinant it's what a * + + align:start position:0% +I expand that determinant it's what a * + + + align:start position:0% +I expand that determinant it's what a * +B minus a * B which is zero + + align:start position:0% +B minus a * B which is zero + + + align:start position:0% +B minus a * B which is zero +and now let me come back to that idea of + + align:start position:0% +and now let me come back to that idea of + + + align:start position:0% +and now let me come back to that idea of +what motivated the whole block of + + align:start position:0% +what motivated the whole block of + + + align:start position:0% +what motivated the whole block of +material here the trouble with writing + + align:start position:0% +material here the trouble with writing + + + align:start position:0% +material here the trouble with writing +vectors as endles that there really is + + align:start position:0% +vectors as endles that there really is + + + align:start position:0% +vectors as endles that there really is +something that requires Great care in + + align:start position:0% +something that requires Great care in + + + align:start position:0% +something that requires Great care in +advanced applications one must always be + + align:start position:0% +advanced applications one must always be + + + align:start position:0% +advanced applications one must always be +wary of this I am not going to give you + + align:start position:0% +wary of this I am not going to give you + + + align:start position:0% +wary of this I am not going to give you +the advanced applications here all I + + align:start position:0% +the advanced applications here all I + + + align:start position:0% +the advanced applications here all I +want you to do is to become prepared + + align:start position:0% +want you to do is to become prepared + + + align:start position:0% +want you to do is to become prepared +against the pitfalls and the thing is + + align:start position:0% +against the pitfalls and the thing is + + + align:start position:0% +against the pitfalls and the thing is +that in dealing with determinance as I + + align:start position:0% +that in dealing with determinance as I + + + align:start position:0% +that in dealing with determinance as I +said before you must be very very + + align:start position:0% +said before you must be very very + + + align:start position:0% +said before you must be very very +careful about what basis you're + + align:start position:0% +careful about what basis you're + + + align:start position:0% +careful about what basis you're +referring to for a given Vector space + + align:start position:0% +referring to for a given Vector space + + + align:start position:0% +referring to for a given Vector space +obviously the vectors do not depend on + + align:start position:0% +obviously the vectors do not depend on + + + align:start position:0% +obviously the vectors do not depend on +the basis but their representation does + + align:start position:0% +the basis but their representation does + + + align:start position:0% +the basis but their representation does +let me give you a for instance using V + + align:start position:0% +let me give you a for instance using V + + + align:start position:0% +let me give you a for instance using V +and U1 and U2 as in example number one + + align:start position:0% +and U1 and U2 as in example number one + + + align:start position:0% +and U1 and U2 as in example number one +suppose we let alpha 1 be the twole 3 + + align:start position:0% +suppose we let alpha 1 be the twole 3 + + + align:start position:0% +suppose we let alpha 1 be the twole 3 +comma 4 in other words 3 U1 + 4 U2 and + + align:start position:0% +comma 4 in other words 3 U1 + 4 U2 and + + + align:start position:0% +comma 4 in other words 3 U1 + 4 U2 and +let Alpha 2 be 2 comma 5 then by what + + align:start position:0% +let Alpha 2 be 2 comma 5 then by what + + + align:start position:0% +let Alpha 2 be 2 comma 5 then by what +we've just proven the determinant of + + align:start position:0% +we've just proven the determinant of + + + align:start position:0% +we've just proven the determinant of +alpha 1 comma Alpha 2 must be the + + align:start position:0% +alpha 1 comma Alpha 2 must be the + + + align:start position:0% +alpha 1 comma Alpha 2 must be the +determinant of what Matrix the one whose + + align:start position:0% +determinant of what Matrix the one whose + + + align:start position:0% +determinant of what Matrix the one whose +first row is 3 comma four and whose + + align:start position:0% +first row is 3 comma four and whose + + + align:start position:0% +first row is 3 comma four and whose +second row is 2 comma 5 if I compute + + align:start position:0% +second row is 2 comma 5 if I compute + + + align:start position:0% +second row is 2 comma 5 if I compute +that determinant by the way notice now + + align:start position:0% +that determinant by the way notice now + + + align:start position:0% +that determinant by the way notice now +that I know that the shortcut way has to + + align:start position:0% +that I know that the shortcut way has to + + + align:start position:0% +that I know that the shortcut way has to +be the right answer I don't do this the + + align:start position:0% +be the right answer I don't do this the + + + align:start position:0% +be the right answer I don't do this the +long way anymore I just say Okay it's 3 + + align:start position:0% +long way anymore I just say Okay it's 3 + + + align:start position:0% +long way anymore I just say Okay it's 3 +* 5 - 2 * 4 15 - 8 which is seven so the + + align:start position:0% +* 5 - 2 * 4 15 - 8 which is seven so the + + + align:start position:0% +* 5 - 2 * 4 15 - 8 which is seven so the +determinant of alpha 1 Alpha 2 is seven + + align:start position:0% +determinant of alpha 1 Alpha 2 is seven + + + align:start position:0% +determinant of alpha 1 Alpha 2 is seven +all right so far so good but let me + + align:start position:0% +all right so far so good but let me + + + align:start position:0% +all right so far so good but let me +point out the following thing notice + + align:start position:0% +point out the following thing notice + + + align:start position:0% +point out the following thing notice +that alpha 1 and Alpha 2 are also + + align:start position:0% +that alpha 1 and Alpha 2 are also + + + align:start position:0% +that alpha 1 and Alpha 2 are also +linearly independent namely 3 comma 4 is + + align:start position:0% +linearly independent namely 3 comma 4 is + + + align:start position:0% +linearly independent namely 3 comma 4 is +not a scalar multiple of 2 comma 5 + + align:start position:0% +not a scalar multiple of 2 comma 5 + + + align:start position:0% +not a scalar multiple of 2 comma 5 +consequently since alpha 1 and Alpha 2 + + align:start position:0% +consequently since alpha 1 and Alpha 2 + + + align:start position:0% +consequently since alpha 1 and Alpha 2 +are linearly independent and since V is + + align:start position:0% +are linearly independent and since V is + + + align:start position:0% +are linearly independent and since V is +a two-dimensional space it means that + + align:start position:0% +a two-dimensional space it means that + + + align:start position:0% +a two-dimensional space it means that +alpha 1 and Alpha 2 are themselves a + + align:start position:0% +alpha 1 and Alpha 2 are themselves a + + + align:start position:0% +alpha 1 and Alpha 2 are themselves a +basis for v in other words V is equal to + + align:start position:0% +basis for v in other words V is equal to + + + align:start position:0% +basis for v in other words V is equal to +the space span by Alpha 1 and Alpha 2 as + + align:start position:0% +the space span by Alpha 1 and Alpha 2 as + + + align:start position:0% +the space span by Alpha 1 and Alpha 2 as +a basis notice that relative to this new + + align:start position:0% +a basis notice that relative to this new + + + align:start position:0% +a basis notice that relative to this new +basis alpha 1 comma Alpha 2 alpha 1 is 1 + + align:start position:0% +basis alpha 1 comma Alpha 2 alpha 1 is 1 + + + align:start position:0% +basis alpha 1 comma Alpha 2 alpha 1 is 1 +Alpha 1 + 0 Alpha 2 Alpha 2 is 0 alpha 1 + + align:start position:0% +Alpha 1 + 0 Alpha 2 Alpha 2 is 0 alpha 1 + + + align:start position:0% +Alpha 1 + 0 Alpha 2 Alpha 2 is 0 alpha 1 ++ 1 Alpha 2 and therefore using the + + align:start position:0% ++ 1 Alpha 2 and therefore using the + + + align:start position:0% ++ 1 Alpha 2 and therefore using the +traditional method of computing the + + align:start position:0% +traditional method of computing the + + + align:start position:0% +traditional method of computing the +determinant notice that the determinant + + align:start position:0% +determinant notice that the determinant + + + align:start position:0% +determinant notice that the determinant +of alpha 1 comma Alpha 2 relative to the + + align:start position:0% +of alpha 1 comma Alpha 2 relative to the + + + align:start position:0% +of alpha 1 comma Alpha 2 relative to the +basis alpha 1 and Alpha 2 would be what + + align:start position:0% +basis alpha 1 and Alpha 2 would be what + + + align:start position:0% +basis alpha 1 and Alpha 2 would be what +determinant it would be the determinant + + align:start position:0% +determinant it would be the determinant + + + align:start position:0% +determinant it would be the determinant +of the Matrix whose first row was one + + align:start position:0% +of the Matrix whose first row was one + + + align:start position:0% +of the Matrix whose first row was one +Zer and whose second row was 01 and that + + align:start position:0% +Zer and whose second row was 01 and that + + + align:start position:0% +Zer and whose second row was 01 and that +is one this looks like a contradiction + + align:start position:0% +is one this looks like a contradiction + + + align:start position:0% +is one this looks like a contradiction +you see on the one hand we have that D + + align:start position:0% +you see on the one hand we have that D + + + align:start position:0% +you see on the one hand we have that D +of alpha 1 Alpha 2 is one but down here + + align:start position:0% +of alpha 1 Alpha 2 is one but down here + + + align:start position:0% +of alpha 1 Alpha 2 is one but down here +we just + + align:start position:0% +we just + + + align:start position:0% +we just +saw that D of alpha 1 Alpha 2 was seven + + align:start position:0% +saw that D of alpha 1 Alpha 2 was seven + + + align:start position:0% +saw that D of alpha 1 Alpha 2 was seven +which is + + align:start position:0% +which is + + + align:start position:0% +which is +correct well the answer is they're both + + align:start position:0% +correct well the answer is they're both + + + align:start position:0% +correct well the answer is they're both +correct that the first observation is + + align:start position:0% +correct that the first observation is + + + align:start position:0% +correct that the first observation is +that if the determinant of alpha 1 and + + align:start position:0% +that if the determinant of alpha 1 and + + + align:start position:0% +that if the determinant of alpha 1 and +Alpha 2 is not zero the value depends on + + align:start position:0% +Alpha 2 is not zero the value depends on + + + align:start position:0% +Alpha 2 is not zero the value depends on +the particular basis in other words if + + align:start position:0% +the particular basis in other words if + + + align:start position:0% +the particular basis in other words if +the determinant is zero it turns out + + align:start position:0% +the determinant is zero it turns out + + + align:start position:0% +the determinant is zero it turns out +that no matter what basis you use to + + align:start position:0% +that no matter what basis you use to + + + align:start position:0% +that no matter what basis you use to +represent the determinant of alpha 1 and + + align:start position:0% +represent the determinant of alpha 1 and + + + align:start position:0% +represent the determinant of alpha 1 and +Alpha 2 you will get zero once the + + align:start position:0% +Alpha 2 you will get zero once the + + + align:start position:0% +Alpha 2 you will get zero once the +determinant is zero in one basis and if + + align:start position:0% +determinant is zero in one basis and if + + + align:start position:0% +determinant is zero in one basis and if +the determinant is not zero with respect + + align:start position:0% +the determinant is not zero with respect + + + align:start position:0% +the determinant is not zero with respect +to a particular basis it will be non + + align:start position:0% +to a particular basis it will be non + + + align:start position:0% +to a particular basis it will be non +zero with respect to all bases but what + + align:start position:0% +zero with respect to all bases but what + + + align:start position:0% +zero with respect to all bases but what +nonzero number it will be does depend on + + align:start position:0% +nonzero number it will be does depend on + + + align:start position:0% +nonzero number it will be does depend on +the basis and that was why way back at + + align:start position:0% +the basis and that was why way back at + + + align:start position:0% +the basis and that was why way back at +the beginning we told the D machine + + align:start position:0% +the beginning we told the D machine + + + align:start position:0% +the beginning we told the D machine +simply to give a nonzero + + align:start position:0% +simply to give a nonzero + + + align:start position:0% +simply to give a nonzero +output if the the input was a set of n + + align:start position:0% +output if the the input was a set of n + + + align:start position:0% +output if the the input was a set of n +linearly independent vectors in summary + + align:start position:0% +linearly independent vectors in summary + + + align:start position:0% +linearly independent vectors in summary +when one says that the determinant of + + align:start position:0% +when one says that the determinant of + + + align:start position:0% +when one says that the determinant of +alpha 1 and Alpha 2 is seven it's + + align:start position:0% +alpha 1 and Alpha 2 is seven it's + + + align:start position:0% +alpha 1 and Alpha 2 is seven it's +tacitly assumed that D is being referred + + align:start position:0% +tacitly assumed that D is being referred + + + align:start position:0% +tacitly assumed that D is being referred +to with respect to the particular basis + + align:start position:0% +to with respect to the particular basis + + + align:start position:0% +to with respect to the particular basis +alpha 1 uh U1 U2 on the other hand when + + align:start position:0% +alpha 1 uh U1 U2 on the other hand when + + + align:start position:0% +alpha 1 uh U1 U2 on the other hand when +one says that D of alpha 1 Alpha 2 is 1 + + align:start position:0% +one says that D of alpha 1 Alpha 2 is 1 + + + align:start position:0% +one says that D of alpha 1 Alpha 2 is 1 +it's tacitly assumed that the basis that + + align:start position:0% +it's tacitly assumed that the basis that + + + align:start position:0% +it's tacitly assumed that the basis that +we're using to express V is Alpha 1 and + + align:start position:0% +we're using to express V is Alpha 1 and + + + align:start position:0% +we're using to express V is Alpha 1 and +Alpha 2 again I'll drill that more in + + align:start position:0% +Alpha 2 again I'll drill that more in + + + align:start position:0% +Alpha 2 again I'll drill that more in +the exercises let me go on now to + + align:start position:0% +the exercises let me go on now to + + + align:start position:0% +the exercises let me go on now to +generalize what happens in n-dimensional + + align:start position:0% +generalize what happens in n-dimensional + + + align:start position:0% +generalize what happens in n-dimensional +space keeping in mind the fact that when + + align:start position:0% +space keeping in mind the fact that when + + + align:start position:0% +space keeping in mind the fact that when +we generalize what happens in + + align:start position:0% +we generalize what happens in + + + align:start position:0% +we generalize what happens in +n-dimensional Space the actual proofs + + align:start position:0% +n-dimensional Space the actual proofs + + + align:start position:0% +n-dimensional Space the actual proofs +become Messier but the theory remains + + align:start position:0% +become Messier but the theory remains + + + align:start position:0% +become Messier but the theory remains +very much the same I prefer to leave the + + align:start position:0% +very much the same I prefer to leave the + + + align:start position:0% +very much the same I prefer to leave the +messy details to the exercises either + + align:start position:0% +messy details to the exercises either + + + align:start position:0% +messy details to the exercises either +optional or required depending on how + + align:start position:0% +optional or required depending on how + + + align:start position:0% +optional or required depending on how +hard the exercises may be but let me + + align:start position:0% +hard the exercises may be but let me + + + align:start position:0% +hard the exercises may be but let me +summarize what the results are for any + + align:start position:0% +summarize what the results are for any + + + align:start position:0% +summarize what the results are for any +n-dimensional space keeping in mind + + align:start position:0% +n-dimensional space keeping in mind + + + align:start position:0% +n-dimensional space keeping in mind +we've proven the results rigorously for + + align:start position:0% +we've proven the results rigorously for + + + align:start position:0% +we've proven the results rigorously for +the case n equals 2 the generalization + + align:start position:0% +the case n equals 2 the generalization + + + align:start position:0% +the case n equals 2 the generalization +is this if I have an N dimensional + + align:start position:0% +is this if I have an N dimensional + + + align:start position:0% +is this if I have an N dimensional +Vector space V with respect to a + + align:start position:0% +Vector space V with respect to a + + + align:start position:0% +Vector space V with respect to a +particular basis U1 up to unu n and if + + align:start position:0% +particular basis U1 up to unu n and if + + + align:start position:0% +particular basis U1 up to unu n and if +alpha 1 up to alpha n are n vectors + + align:start position:0% +alpha 1 up to alpha n are n vectors + + + align:start position:0% +alpha 1 up to alpha n are n vectors +chosen from V so that they are linear + + align:start position:0% +chosen from V so that they are linear + + + align:start position:0% +chosen from V so that they are linear +combinations of the U's say in the + + align:start position:0% +combinations of the U's say in the + + + align:start position:0% +combinations of the U's say in the +traditional way that we've written these + + align:start position:0% +traditional way that we've written these + + + align:start position:0% +traditional way that we've written these +all the time it turns out the following + + align:start position:0% +all the time it turns out the following + + + align:start position:0% +all the time it turns out the following +that the determinant of alpha 1 up to + + align:start position:0% +that the determinant of alpha 1 up to + + + align:start position:0% +that the determinant of alpha 1 up to +Alpha + + align:start position:0% +Alpha + + + align:start position:0% +Alpha +n first of all it's conventional and + + align:start position:0% +n first of all it's conventional and + + + align:start position:0% +n first of all it's conventional and +convenient to write the determinant as + + align:start position:0% +convenient to write the determinant as + + + align:start position:0% +convenient to write the determinant as +if it were a matrix only replacing the + + align:start position:0% +if it were a matrix only replacing the + + + align:start position:0% +if it were a matrix only replacing the +square brackets by sort of absolute + + align:start position:0% +square brackets by sort of absolute + + + align:start position:0% +square brackets by sort of absolute +value signs vertical lines what we do is + + align:start position:0% +value signs vertical lines what we do is + + + align:start position:0% +value signs vertical lines what we do is +notice that alpha 1 is written as an + + align:start position:0% +notice that alpha 1 is written as an + + + align:start position:0% +notice that alpha 1 is written as an +nppo a11 up to a1n in other words the + + align:start position:0% +nppo a11 up to a1n in other words the + + + align:start position:0% +nppo a11 up to a1n in other words the +first row of the determinant represents + + align:start position:0% +first row of the determinant represents + + + align:start position:0% +first row of the determinant represents +alpha 1 as an nle Vector relative to the + + align:start position:0% +alpha 1 as an nle Vector relative to the + + + align:start position:0% +alpha 1 as an nle Vector relative to the +basis U1 up to unu n and a similar thing + + align:start position:0% +basis U1 up to unu n and a similar thing + + + align:start position:0% +basis U1 up to unu n and a similar thing +holds for Alpha 2 through alpha n and + + align:start position:0% +holds for Alpha 2 through alpha n and + + + align:start position:0% +holds for Alpha 2 through alpha n and +you may remember I told you what the + + align:start position:0% +you may remember I told you what the + + + align:start position:0% +you may remember I told you what the +recipe was when we were dealing with uh + + align:start position:0% +recipe was when we were dealing with uh + + + align:start position:0% +recipe was when we were dealing with uh +I told you what the re was when we were + + align:start position:0% +I told you what the re was when we were + + + align:start position:0% +I told you what the re was when we were +dealing with cross products and the like + + align:start position:0% +dealing with cross products and the like + + + align:start position:0% +dealing with cross products and the like +and the idea is simply this what you do + + align:start position:0% +and the idea is simply this what you do + + + align:start position:0% +and the idea is simply this what you do +is is you start in the upper left hand + + align:start position:0% +is is you start in the upper left hand + + + align:start position:0% +is is you start in the upper left hand +corner writing a plus sign then you + + align:start position:0% +corner writing a plus sign then you + + + align:start position:0% +corner writing a plus sign then you +alternate going along rows and columns + + align:start position:0% +alternate going along rows and columns + + + align:start position:0% +alternate going along rows and columns +in any order you want writing plus minus + + align:start position:0% +in any order you want writing plus minus + + + align:start position:0% +in any order you want writing plus minus +plus minus Etc plusus plus minus Etc + + align:start position:0% +plus minus Etc plusus plus minus Etc + + + align:start position:0% +plus minus Etc plusus plus minus Etc +pick any row or column that you want and + + align:start position:0% +pick any row or column that you want and + + + align:start position:0% +pick any row or column that you want and +then you go down that row or column + + align:start position:0% +then you go down that row or column + + + align:start position:0% +then you go down that row or column +factoring out a particular term the plus + + align:start position:0% +factoring out a particular term the plus + + + align:start position:0% +factoring out a particular term the plus +sign telling you to take out the term as + + align:start position:0% +sign telling you to take out the term as + + + align:start position:0% +sign telling you to take out the term as +it is the minus sign telling you to take + + align:start position:0% +it is the minus sign telling you to take + + + align:start position:0% +it is the minus sign telling you to take +out the term and change its sign and you + + align:start position:0% +out the term and change its sign and you + + + align:start position:0% +out the term and change its sign and you +multiply that term by the nus1 by nus1 + + align:start position:0% +multiply that term by the nus1 by nus1 + + + align:start position:0% +multiply that term by the nus1 by nus1 +matrix that's left when you strike out + + align:start position:0% +matrix that's left when you strike out + + + align:start position:0% +matrix that's left when you strike out +the row and column in which that term + + align:start position:0% +the row and column in which that term + + + align:start position:0% +the row and column in which that term +occurs now if that still sounds like a + + align:start position:0% +occurs now if that still sounds like a + + + align:start position:0% +occurs now if that still sounds like a +tongue twister let's do this in terms of + + align:start position:0% +tongue twister let's do this in terms of + + + align:start position:0% +tongue twister let's do this in terms of +a specific semi-abstract semic concrete + + align:start position:0% +a specific semi-abstract semic concrete + + + align:start position:0% +a specific semi-abstract semic concrete +four-dimensional case namely let's + + align:start position:0% +four-dimensional case namely let's + + + align:start position:0% +four-dimensional case namely let's +suppose V is a four-dimensional vector + + align:start position:0% +suppose V is a four-dimensional vector + + + align:start position:0% +suppose V is a four-dimensional vector +space relative to a particular basis U1 + + align:start position:0% +space relative to a particular basis U1 + + + align:start position:0% +space relative to a particular basis U1 +U2 u3 and u4 suppose alpha 1 Alpha 2 + + align:start position:0% +U2 u3 and u4 suppose alpha 1 Alpha 2 + + + align:start position:0% +U2 u3 and u4 suppose alpha 1 Alpha 2 +Alpha 3 and Alpha 4 are these four + + align:start position:0% +Alpha 3 and Alpha 4 are these four + + + align:start position:0% +Alpha 3 and Alpha 4 are these four +specific vectors of v and again I can't + + align:start position:0% +specific vectors of v and again I can't + + + align:start position:0% +specific vectors of v and again I can't +keep emphasizing this too much even + + align:start position:0% +keep emphasizing this too much even + + + align:start position:0% +keep emphasizing this too much even +though I hope some of you are bored + + align:start position:0% +though I hope some of you are bored + + + align:start position:0% +though I hope some of you are bored +because you know it so well it's always + + align:start position:0% +because you know it so well it's always + + + align:start position:0% +because you know it so well it's always +understood when I write this that the + + align:start position:0% +understood when I write this that the + + + align:start position:0% +understood when I write this that the +components are relative to U1 U2 u3 u4 + + align:start position:0% +components are relative to U1 U2 u3 u4 + + + align:start position:0% +components are relative to U1 U2 u3 u4 +for example this is 3u 1 + 5 U2 + 7 u3 + + + align:start position:0% +for example this is 3u 1 + 5 U2 + 7 u3 + + + + align:start position:0% +for example this is 3u 1 + 5 U2 + 7 u3 + +2 u4 now the traditional way of + + align:start position:0% +2 u4 now the traditional way of + + + align:start position:0% +2 u4 now the traditional way of +expanding this determinant is you write + + align:start position:0% +expanding this determinant is you write + + + align:start position:0% +expanding this determinant is you write +down the + + align:start position:0% +down the + + + align:start position:0% +down the +rows as the endle see you write down + + align:start position:0% +rows as the endle see you write down + + + align:start position:0% +rows as the endle see you write down +this is your first row second row third + + align:start position:0% +this is your first row second row third + + + align:start position:0% +this is your first row second row third +row fourth row see notice that + + align:start position:0% +row fourth row see notice that + + + align:start position:0% +row fourth row see notice that +the determinant is an N byn array of + + align:start position:0% +the determinant is an N byn array of + + + align:start position:0% +the determinant is an N byn array of +numbers that you have four vectors each + + align:start position:0% +numbers that you have four vectors each + + + align:start position:0% +numbers that you have four vectors each +Vector is a four tle and this is how you + + align:start position:0% +Vector is a four tle and this is how you + + + align:start position:0% +Vector is a four tle and this is how you +get this determinant now what do we do + + align:start position:0% +get this determinant now what do we do + + + align:start position:0% +get this determinant now what do we do +next next let's say for the sake of + + align:start position:0% +next next let's say for the sake of + + + align:start position:0% +next next let's say for the sake of +argument I elect to expand this + + align:start position:0% +argument I elect to expand this + + + align:start position:0% +argument I elect to expand this +determinant along the top row I first + + align:start position:0% +determinant along the top row I first + + + align:start position:0% +determinant along the top row I first +take the one out because it has a plus + + align:start position:0% +take the one out because it has a plus + + + align:start position:0% +take the one out because it has a plus +sign it comes out as one I multiply that + + align:start position:0% +sign it comes out as one I multiply that + + + align:start position:0% +sign it comes out as one I multiply that +by the 3X3 determinant that's left when + + align:start position:0% +by the 3X3 determinant that's left when + + + align:start position:0% +by the 3X3 determinant that's left when +I strike out the row and column in which + + align:start position:0% +I strike out the row and column in which + + + align:start position:0% +I strike out the row and column in which +one + + align:start position:0% +one + + + align:start position:0% +one +appears I take out two but make it a + + align:start position:0% +appears I take out two but make it a + + + align:start position:0% +appears I take out two but make it a +minus because of this signature here and + + align:start position:0% +minus because of this signature here and + + + align:start position:0% +minus because of this signature here and +multiply that by the 3X3 determinant + + align:start position:0% +multiply that by the 3X3 determinant + + + align:start position:0% +multiply that by the 3X3 determinant +that's left when I strike out the row + + align:start position:0% +that's left when I strike out the row + + + align:start position:0% +that's left when I strike out the row +and column in which two appears I factor + + align:start position:0% +and column in which two appears I factor + + + align:start position:0% +and column in which two appears I factor +out one as it is and multiply that by + + align:start position:0% +out one as it is and multiply that by + + + align:start position:0% +out one as it is and multiply that by +the 3X3 determinant that's left when I + + align:start position:0% +the 3X3 determinant that's left when I + + + align:start position:0% +the 3X3 determinant that's left when I +strike out the row and column in which + + align:start position:0% +strike out the row and column in which + + + align:start position:0% +strike out the row and column in which +this one appears and finally I take out + + align:start position:0% +this one appears and finally I take out + + + align:start position:0% +this one appears and finally I take out +this minus one and change its sign + + align:start position:0% +this minus one and change its sign + + + align:start position:0% +this minus one and change its sign +because of this minus code over here in + + align:start position:0% +because of this minus code over here in + + + align:start position:0% +because of this minus code over here in +other words comes out as a plus one + + align:start position:0% +other words comes out as a plus one + + + align:start position:0% +other words comes out as a plus one +multiplied by the 3X3 determinant that's + + align:start position:0% +multiplied by the 3X3 determinant that's + + + align:start position:0% +multiplied by the 3X3 determinant that's +left when I strike out the row and + + align:start position:0% +left when I strike out the row and + + + align:start position:0% +left when I strike out the row and +column in which minus one appears in and + + align:start position:0% +column in which minus one appears in and + + + align:start position:0% +column in which minus one appears in and +to make a long story short all we're + + align:start position:0% +to make a long story short all we're + + + align:start position:0% +to make a long story short all we're +saying is that this 4x4 determinant can + + align:start position:0% +saying is that this 4x4 determinant can + + + align:start position:0% +saying is that this 4x4 determinant can +be written as a sum of four 3x3 + + align:start position:0% +be written as a sum of four 3x3 + + + align:start position:0% +be written as a sum of four 3x3 +determinants + + align:start position:0% +determinants + + + align:start position:0% +determinants +namely this which is precisely what I + + align:start position:0% +namely this which is precisely what I + + + align:start position:0% +namely this which is precisely what I +was saying the long way up here now what + + align:start position:0% +was saying the long way up here now what + + + align:start position:0% +was saying the long way up here now what +we say is each of these 3x 3s can be + + align:start position:0% +we say is each of these 3x 3s can be + + + align:start position:0% +we say is each of these 3x 3s can be +written as 3 2x2s namely I can factor + + align:start position:0% +written as 3 2x2s namely I can factor + + + align:start position:0% +written as 3 2x2s namely I can factor +out say again going across the top row I + + align:start position:0% +out say again going across the top row I + + + align:start position:0% +out say again going across the top row I +can pick any row or any column but let + + align:start position:0% +can pick any row or any column but let + + + align:start position:0% +can pick any row or any column but let +me stick to the top row like we did in i + + align:start position:0% +me stick to the top row like we did in i + + + align:start position:0% +me stick to the top row like we did in i +j and k for the time being but this + + align:start position:0% +j and k for the time being but this + + + align:start position:0% +j and k for the time being but this +becomes what 5 * this 2x two Matrix + + align:start position:0% +becomes what 5 * this 2x two Matrix + + + align:start position:0% +becomes what 5 * this 2x two Matrix +minus 3 3 * this 2x2 matrix plus 1 * + + align:start position:0% +minus 3 3 * this 2x2 matrix plus 1 * + + + align:start position:0% +minus 3 3 * this 2x2 matrix plus 1 * +this 2x2 matrix in other words this + + align:start position:0% +this 2x2 matrix in other words this + + + align:start position:0% +this 2x2 matrix in other words this +expression here I can now do that for + + align:start position:0% +expression here I can now do that for + + + align:start position:0% +expression here I can now do that for +each of these so each of the three by 3s + + align:start position:0% +each of these so each of the three by 3s + + + align:start position:0% +each of these so each of the three by 3s +give me 3 2x 2s so Al together I would + + align:start position:0% +give me 3 2x 2s so Al together I would + + + align:start position:0% +give me 3 2x 2s so Al together I would +have 12 2X tws and go through this whole + + align:start position:0% +have 12 2X tws and go through this whole + + + align:start position:0% +have 12 2X tws and go through this whole +mess to compute this thing and this can + + align:start position:0% +mess to compute this thing and this can + + + align:start position:0% +mess to compute this thing and this can +be a very very difficult sure this was + + align:start position:0% +be a very very difficult sure this was + + + align:start position:0% +be a very very difficult sure this was +only a four-dimensional case imagine + + align:start position:0% +only a four-dimensional case imagine + + + align:start position:0% +only a four-dimensional case imagine +trying to apply this technique for a + + align:start position:0% +trying to apply this technique for a + + + align:start position:0% +trying to apply this technique for a +uh a 10-dimensional vector space for the + + align:start position:0% +uh a 10-dimensional vector space for the + + + align:start position:0% +uh a 10-dimensional vector space for the +sake of argument it turns + + align:start position:0% +sake of argument it turns + + + align:start position:0% +sake of argument it turns +out that that + + align:start position:0% +out that that + + + align:start position:0% +out that that +recipe that we called theorem two gives + + align:start position:0% +recipe that we called theorem two gives + + + align:start position:0% +recipe that we called theorem two gives +us a tie-in between row reduced + + align:start position:0% +us a tie-in between row reduced + + + align:start position:0% +us a tie-in between row reduced +matrices and a quick way to compute + + align:start position:0% +matrices and a quick way to compute + + + align:start position:0% +matrices and a quick way to compute +determinants for example let's suppose + + align:start position:0% +determinants for example let's suppose + + + align:start position:0% +determinants for example let's suppose +we still wanted to compute the same + + align:start position:0% +we still wanted to compute the same + + + align:start position:0% +we still wanted to compute the same +determinant that we've written down over + + align:start position:0% +determinant that we've written down over + + + align:start position:0% +determinant that we've written down over +here let's call that let's write let's + + align:start position:0% +here let's call that let's write let's + + + align:start position:0% +here let's call that let's write let's +write it again over here what we already + + align:start position:0% +write it again over here what we already + + + align:start position:0% +write it again over here what we already +know is if I would to replace the second + + align:start position:0% +know is if I would to replace the second + + + align:start position:0% +know is if I would to replace the second +vector by the second minus twice the + + align:start position:0% +vector by the second minus twice the + + + align:start position:0% +vector by the second minus twice the +first the determinant does not change + + align:start position:0% +first the determinant does not change + + + align:start position:0% +first the determinant does not change +that's what theorem 2 said if you + + align:start position:0% +that's what theorem 2 said if you + + + align:start position:0% +that's what theorem 2 said if you +replace one vector by itself plus a + + align:start position:0% +replace one vector by itself plus a + + + align:start position:0% +replace one vector by itself plus a +Scala multiple of another you don't + + align:start position:0% +Scala multiple of another you don't + + + align:start position:0% +Scala multiple of another you don't +change the determinant similarly if I + + align:start position:0% +change the determinant similarly if I + + + align:start position:0% +change the determinant similarly if I +were to replace this vector by three + + align:start position:0% +were to replace this vector by three + + + align:start position:0% +were to replace this vector by three +times the first Vector I would still + + align:start position:0% +times the first Vector I would still + + + align:start position:0% +times the first Vector I would still +have the same determinant and finally if + + align:start position:0% +have the same determinant and finally if + + + align:start position:0% +have the same determinant and finally if +I were to replace this vector by three + + align:start position:0% +I were to replace this vector by three + + + align:start position:0% +I were to replace this vector by three +times the first Vector I would still + + align:start position:0% +times the first Vector I would still + + + align:start position:0% +times the first Vector I would still +have the same determinant I don't know + + align:start position:0% +have the same determinant I don't know + + + align:start position:0% +have the same determinant I don't know +if you've notice what I've been driving + + align:start position:0% +if you've notice what I've been driving + + + align:start position:0% +if you've notice what I've been driving +at but wasn't what I was saying here the + + align:start position:0% +at but wasn't what I was saying here the + + + align:start position:0% +at but wasn't what I was saying here the +same computational steps that one goes + + align:start position:0% +same computational steps that one goes + + + align:start position:0% +same computational steps that one goes +through in row reducing a matrix in + + align:start position:0% +through in row reducing a matrix in + + + align:start position:0% +through in row reducing a matrix in +other words let me row reduce this + + align:start position:0% +other words let me row reduce this + + + align:start position:0% +other words let me row reduce this +Matrix so that I get zeros every place + + align:start position:0% +Matrix so that I get zeros every place + + + align:start position:0% +Matrix so that I get zeros every place +say in My First + + align:start position:0% +say in My First + + + align:start position:0% +say in My First +Column except in the upper column by the + + align:start position:0% +Column except in the upper column by the + + + align:start position:0% +Column except in the upper column by the +way notice over here I always have the + + align:start position:0% +way notice over here I always have the + + + align:start position:0% +way notice over here I always have the +habit of putting a one in the upper left + + align:start position:0% +habit of putting a one in the upper left + + + align:start position:0% +habit of putting a one in the upper left +hand corner that's simply to uh + + align:start position:0% +hand corner that's simply to uh + + + align:start position:0% +hand corner that's simply to uh +facilitate the arithmetic I hope by this + + align:start position:0% +facilitate the arithmetic I hope by this + + + align:start position:0% +facilitate the arithmetic I hope by this +stage of the game you realize if this + + align:start position:0% +stage of the game you realize if this + + + align:start position:0% +stage of the game you realize if this +weren't a one I can always divide + + align:start position:0% +weren't a one I can always divide + + + align:start position:0% +weren't a one I can always divide +through by it or what have you and do + + align:start position:0% +through by it or what have you and do + + + align:start position:0% +through by it or what have you and do +the arithmetic another way I just do + + align:start position:0% +the arithmetic another way I just do + + + align:start position:0% +the arithmetic another way I just do +this thing for convenience but the + + align:start position:0% +this thing for convenience but the + + + align:start position:0% +this thing for convenience but the +important point is that this determinant + + align:start position:0% +important point is that this determinant + + + align:start position:0% +important point is that this determinant +is now equal to this determinant and be + + align:start position:0% +is now equal to this determinant and be + + + align:start position:0% +is now equal to this determinant and be +very careful notice if these had been + + align:start position:0% +very careful notice if these had been + + + align:start position:0% +very careful notice if these had been +matrices those if I put square brackets + + align:start position:0% +matrices those if I put square brackets + + + align:start position:0% +matrices those if I put square brackets +here and had made these matrices we + + align:start position:0% +here and had made these matrices we + + + align:start position:0% +here and had made these matrices we +would call the two matrices equivalent + + align:start position:0% +would call the two matrices equivalent + + + align:start position:0% +would call the two matrices equivalent +but different row equivalent but + + align:start position:0% +but different row equivalent but + + + align:start position:0% +but different row equivalent but +different matrices notice the + + align:start position:0% +different matrices notice the + + + align:start position:0% +different matrices notice the +determinant is a number and what we're + + align:start position:0% +determinant is a number and what we're + + + align:start position:0% +determinant is a number and what we're +saying saying is that the number named + + align:start position:0% +saying saying is that the number named + + + align:start position:0% +saying saying is that the number named +by this determinant is equal to the + + align:start position:0% +by this determinant is equal to the + + + align:start position:0% +by this determinant is equal to the +number named by this determinant all + + align:start position:0% +number named by this determinant all + + + align:start position:0% +number named by this determinant all +right + + align:start position:0% +right + + + align:start position:0% +right +equal here's the key point I now notice + + align:start position:0% +equal here's the key point I now notice + + + align:start position:0% +equal here's the key point I now notice +that I have three zeros in the First + + align:start position:0% +that I have three zeros in the First + + + align:start position:0% +that I have three zeros in the First +Column I therefore elect to expand this + + align:start position:0% +Column I therefore elect to expand this + + + align:start position:0% +Column I therefore elect to expand this +determinant along the First Column why + + align:start position:0% +determinant along the First Column why + + + align:start position:0% +determinant along the First Column why +do I do this well let's take a look + + align:start position:0% +do I do this well let's take a look + + + align:start position:0% +do I do this well let's take a look +first of all I get a one multiplied by + + align:start position:0% +first of all I get a one multiplied by + + + align:start position:0% +first of all I get a one multiplied by +this 3x3 determinant that's left when I + + align:start position:0% +this 3x3 determinant that's left when I + + + align:start position:0% +this 3x3 determinant that's left when I +strike out the row and column in which + + align:start position:0% +strike out the row and column in which + + + align:start position:0% +strike out the row and column in which +one appears the beauty is that when I + + align:start position:0% +one appears the beauty is that when I + + + align:start position:0% +one appears the beauty is that when I +form the other three determinants 3x3 + + align:start position:0% +form the other three determinants 3x3 + + + align:start position:0% +form the other three determinants 3x3 +determinants they're all going to be + + align:start position:0% +determinants they're all going to be + + + align:start position:0% +determinants they're all going to be +multiplied by zero for example over here + + align:start position:0% +multiplied by zero for example over here + + + align:start position:0% +multiplied by zero for example over here +I factor out well minus 0 which is still + + align:start position:0% +I factor out well minus 0 which is still + + + align:start position:0% +I factor out well minus 0 which is still +zero what do I multiply that by I + + align:start position:0% +zero what do I multiply that by I + + + align:start position:0% +zero what do I multiply that by I +multiply that by the 3X3 determinant + + align:start position:0% +multiply that by the 3X3 determinant + + + align:start position:0% +multiply that by the 3X3 determinant +that's left when I strike out the row + + align:start position:0% +that's left when I strike out the row + + + align:start position:0% +that's left when I strike out the row +and column that this zero appears in + + align:start position:0% +and column that this zero appears in + + + align:start position:0% +and column that this zero appears in +namely the 3X3 determinant 2 1 -1 + + align:start position:0% +namely the 3X3 determinant 2 1 -1 + + + align:start position:0% +namely the 3X3 determinant 2 1 -1 +-145 2 3 4 but since that's being + + align:start position:0% +-145 2 3 4 but since that's being + + + align:start position:0% +-145 2 3 4 but since that's being +multiplied by zero the product will be + + align:start position:0% +multiplied by zero the product will be + + + align:start position:0% +multiplied by zero the product will be +zero to make a long story short to + + align:start position:0% +zero to make a long story short to + + + align:start position:0% +zero to make a long story short to +evaluate this determinant it's simply + + align:start position:0% +evaluate this determinant it's simply + + + align:start position:0% +evaluate this determinant it's simply +what + one times this 3x3 determinant I + + align:start position:0% +what + one times this 3x3 determinant I + + + align:start position:0% +what + one times this 3x3 determinant I +put the one in parenthesis here to + + align:start position:0% +put the one in parenthesis here to + + + align:start position:0% +put the one in parenthesis here to +indicate that I really factored that one + + align:start position:0% +indicate that I really factored that one + + + align:start position:0% +indicate that I really factored that one +out but really what we're saying is that + + align:start position:0% +out but really what we're saying is that + + + align:start position:0% +out but really what we're saying is that +this 4x4 determinant has the same value + + align:start position:0% +this 4x4 determinant has the same value + + + align:start position:0% +this 4x4 determinant has the same value +as this 3x3 determinant and now I R + + align:start position:0% +as this 3x3 determinant and now I R + + + align:start position:0% +as this 3x3 determinant and now I R +reduce this 3x3 determinant I replace + + align:start position:0% +reduce this 3x3 determinant I replace + + + align:start position:0% +reduce this 3x3 determinant I replace +the second Row in other words the second + + align:start position:0% +the second Row in other words the second + + + align:start position:0% +the second Row in other words the second +vector by the second plus the 1 the + + align:start position:0% +vector by the second plus the 1 the + + + align:start position:0% +vector by the second plus the 1 the +third by the third minus twice the 1 I + + align:start position:0% +third by the third minus twice the 1 I + + + align:start position:0% +third by the third minus twice the 1 I +now wind up with this 3x3 determinant + + align:start position:0% +now wind up with this 3x3 determinant + + + align:start position:0% +now wind up with this 3x3 determinant +since I don't change the value of the + + align:start position:0% +since I don't change the value of the + + + align:start position:0% +since I don't change the value of the +determinant when I replace one vector by + + align:start position:0% +determinant when I replace one vector by + + + align:start position:0% +determinant when I replace one vector by +itself plus a Scala multiple of another + + align:start position:0% +itself plus a Scala multiple of another + + + align:start position:0% +itself plus a Scala multiple of another +then notice very quickly that what + + align:start position:0% +then notice very quickly that what + + + align:start position:0% +then notice very quickly that what +happens over here is that these two + + align:start position:0% +happens over here is that these two + + + align:start position:0% +happens over here is that these two +determinants are equal again I elect to + + align:start position:0% +determinants are equal again I elect to + + + align:start position:0% +determinants are equal again I elect to +expand along the First Column factoring + + align:start position:0% +expand along the First Column factoring + + + align:start position:0% +expand along the First Column factoring +out the plus one being left with with + + align:start position:0% +out the plus one being left with with + + + align:start position:0% +out the plus one being left with with +the Matrix at the determinant whose + + align:start position:0% +the Matrix at the determinant whose + + + align:start position:0% +the Matrix at the determinant whose +entries are + + align:start position:0% +entries are + + + align:start position:0% +entries are +5811 and the other two terms contribute + + align:start position:0% +5811 and the other two terms contribute + + + align:start position:0% +5811 and the other two terms contribute +nothing because the coefficient is zero + + align:start position:0% +nothing because the coefficient is zero + + + align:start position:0% +nothing because the coefficient is zero +but I already know how to expand I've + + align:start position:0% +but I already know how to expand I've + + + align:start position:0% +but I already know how to expand I've +proven that how to expand a 2x2 matrix + + align:start position:0% +proven that how to expand a 2x2 matrix + + + align:start position:0% +proven that how to expand a 2x2 matrix +uh determinant that's just going to be + + align:start position:0% +uh determinant that's just going to be + + + align:start position:0% +uh determinant that's just going to be +what 5 - 8 or minus 3 and that's how the + + align:start position:0% +what 5 - 8 or minus 3 and that's how the + + + align:start position:0% +what 5 - 8 or minus 3 and that's how the +shortcut row reduction works much much + + align:start position:0% +shortcut row reduction works much much + + + align:start position:0% +shortcut row reduction works much much +more elegantly than the Brute Force + + align:start position:0% +more elegantly than the Brute Force + + + align:start position:0% +more elegantly than the Brute Force +technique and by the way this is the + + align:start position:0% +technique and by the way this is the + + + align:start position:0% +technique and by the way this is the +technique used in most if not all + + align:start position:0% +technique used in most if not all + + + align:start position:0% +technique used in most if not all +computers in determining the determinant + + align:start position:0% +computers in determining the determinant + + + align:start position:0% +computers in determining the determinant +of a set of n vectors in an + + align:start position:0% +of a set of n vectors in an + + + align:start position:0% +of a set of n vectors in an +n-dimensional Vector space well as I say + + align:start position:0% +n-dimensional Vector space well as I say + + + align:start position:0% +n-dimensional Vector space well as I say +this was meant as an overview I hope you + + align:start position:0% +this was meant as an overview I hope you + + + align:start position:0% +this was meant as an overview I hope you +now see the overall picture of what + + align:start position:0% +now see the overall picture of what + + + align:start position:0% +now see the overall picture of what +determinants are all about and in the + + align:start position:0% +determinants are all about and in the + + + align:start position:0% +determinants are all about and in the +excises I will try to give you some more + + align:start position:0% +excises I will try to give you some more + + + align:start position:0% +excises I will try to give you some more +sophisticated and elaborate + + align:start position:0% +sophisticated and elaborate + + + align:start position:0% +sophisticated and elaborate +details next time what we will do is + + align:start position:0% +details next time what we will do is + + + align:start position:0% +details next time what we will do is +talk about an application of how + + align:start position:0% +talk about an application of how + + + align:start position:0% +talk about an application of how +determinants are used in certain aspects + + align:start position:0% +determinants are used in certain aspects + + + align:start position:0% +determinants are used in certain aspects +ects of vector spaces in particular + + align:start position:0% +ects of vector spaces in particular + + + align:start position:0% +ects of vector spaces in particular +we're going to talk about something + + align:start position:0% +we're going to talk about something + + + align:start position:0% +we're going to talk about something +called uh igen values or igen vectors + + align:start position:0% +called uh igen values or igen vectors + + + align:start position:0% +called uh igen values or igen vectors +but more about that next time until next + + align:start position:0% +but more about that next time until next + + + align:start position:0% +but more about that next time until next +time + + align:start position:0% +time + + + align:start position:0% +time +goodbye funding for the publication of + + align:start position:0% +goodbye funding for the publication of + + + align:start position:0% +goodbye funding for the publication of +this video was provided by the Gabriella + + align:start position:0% +this video was provided by the Gabriella + + + align:start position:0% +this video was provided by the Gabriella +and Paul rosenbom + + align:start position:0% +and Paul rosenbom + + + align:start position:0% +and Paul rosenbom +foundation help ocw continue to provide + + align:start position:0% +foundation help ocw continue to provide + + + align:start position:0% +foundation help ocw continue to provide +free and open access to MIT courses by + + align:start position:0% +free and open access to MIT courses by + + + align:start position:0% +free and open access to MIT courses by +making a donation at + + align:start position:0% +making a donation at + + + align:start position:0% +making a donation at +ocw.mit.edu slash + + align:start position:0% +ocw.mit.edu slash + + + align:start position:0% +ocw.mit.edu slash +donate \ No newline at end of file diff --git a/D3bblng-Kcc.txt b/D3bblng-Kcc.txt new file mode 100644 index 0000000000000000000000000000000000000000..7bda797b52803f8f64458408917da6081d871751 --- /dev/null +++ b/D3bblng-Kcc.txt @@ -0,0 +1,1530 @@ +The following content is +provided under a Creative + +Commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high-quality educational +resources for free. + +To make a donation or view +additional materials from + +hundreds of MIT courses, visit +MIT OpenCourseWare at + +ocw.mit.edu. + +[MUSIC PLAYING] + +PROFESSOR: Last time, we began +a discussion of feedback. + +And I briefly introduced a +number of applications. + +For example, the use of feedback +in compensating for + +non-ideal elements +in a system. + +And also, as another example, +the use of feedback in + +stabilizing unstable systems. + +In this final lecture, what +I'd like to do is focus in + +more detail on the use +of feedback to + +stabilize unstable systems. + +And the specific context in +which I'd like to do that is + +in the context of the +inverted pendulum. + +Now, I've referred to the +inverted pendulum in several + +past lectures. + +And, basically, as everyone +realizes, a pendulum is + +essentially a rod with a +weight on the bottom. + +And, naturally, an inverted +pendulum is just + +that, upside down. + +And so it's essentially a +rod that's top-heavy. + +And the idea with the inverted +pendulum is, although by + +itself it's unstable around a +pivot point at the bottom, the + +idea is to apply an external +input, an acceleration, + +essentially to keep +it balanced. + +And we've all probably done +this type of thing at some + +point in our lives, either +childhood or not. + +And so that's the system that +I'd like to analyze and then + +illustrate in this lecture. + +Now, the context in which we'll +do that is not with my + +son's horse, but actually with +an inverted pendulum which is + +mounted on a cart. + +And first I'd like to go through +an analysis of it, and + +then we'll actually see +how the system works. + +So basically, then, the system +that we're talking about is + +going to be a system which +is a movable cart. + +Mounted on the cart is a rod +with a weight on the top. + +And this then becomes the +inverted pendulum. + +And the cart has an external +acceleration applied to it, + +which is the input that we +can apply to the system. + +And then, in general, we can +expect some disturbances. + +And I'm going to represent the +disturbances in terms of an + +angular acceleration, which +shows up around the weight at + +the top of the rod. + +So if we look at the system, +then, as I've kind of + +indicated it here, basically +we have two inputs. + +We have an input, which are +the external disturbances, + +which we can assume that we +have no control over. + +And then there is the +acceleration that's apply to + +the cart externally, or in the +case of balancing my son's + +horse, it's the movement +of my hand. + +And then, through the system +dynamics, that ends up + +influencing the angle +of the rod. + +And we'll think of the +angle of the rod + +as the system output. + +And basically the idea, then, +is to try to keep that angle + +at 0 by applying the appropriate +acceleration. + +Now, as I've mentioned several +times previously, if we know + +exactly what the system dynamics +are, and if we know + +exactly what the external +disturbances are, then + +theoretically we can choose an +acceleration for the cart + +which will exactly balance the +system, or balance the rod. + +However, since the system is +inherently unstable, any + +deviation from that model-- in +particular, any unanticipated + +external disturbances-- + +will excite the instability. + +And what that means is that +the rod will fall. + +So the idea, then, is, as we'll +see, to stabilize the + +system by placing feedback +around it. + +In particular through a +measurement of the output + +angle, processed through some +appropriate feedback dynamics, + +using that to control the +acceleration of the cart. + +And if we choose the feedback +dynamics correctly, then, in + +fact, we can end up with a +stable system, even though the + +open-loop system is unstable. + +Well, as a first step, let's +analyze the system in its + +open-loop form. + +In particular, let's analyze the +system without feedback, + +demonstrate that, indeed, it is +unstable, and then see how + +we can stabilize it +using feedback. + +So the system, then, is-- + +as we've indicated, the +variables involved are the + +measured angle, which represents +the output, the + +angular acceleration due to +external disturbances, and + +then there is the +applied external + +acceleration on the cart. + +So these represent the +variables, with L representing + +the length of the rod, and s of +t I indicate here, which we + +won't really be paying attention +to, as the position + +of the cart. + +And without going into the +details specifically, what + +we'll do is set up the equation, +or write the + +equation, in terms of balancing +the acceleration. + +And if you go through that +process, then the basic + +equation that you end up with +is the equation that I + +indicate here. + +And this equation, then, tells +us how the basic forces, or + +accelerations, are balanced, +where this is the second + +derivative of the angle. + +And then we have the +acceleration due to gravity, + +reflected through the angular +acceleration times the sine of + +the angle, the angular +acceleration due to the + +external disturbances, and +finally, the angular + +acceleration due to the +motion of the cart. + +Now, this equation, as it's +written here, is a nonlinear + +equation in the angle +theta of t. + +And what we'd like to do is +linearize the equation. + +And we'll linearize the +equation by making the + +assumption that the angle is +very small, close to 0. + +In other words, what we'll +assume is that we're able to + +keep the rod relatively +vertical. + +And our analysis, because +we're linearizing the + +equations, will obviously +depend on that. + +So making the assumption that +the angle is small, we then + +assume that the sine of the +angle is approximately equal + +to the angle, and the cosine of +the angle is approximately + +equal to 1. + +That will then linearize +this equation. + +And the resulting equation, +then, in its linearized form, + +is the one that I +indicate here. + +So we have an equation of +motion, which linearizes the + +balance of the accelerations. + +And what we see on the +right-hand side of the + +equation is the combined inputs +due to the angular + +acceleration of the rod and the +acceleration of the cart. + +And on the left-hand side of +the equation, we have the + +other forces due to the +change in the angle. + +So this is, then, the +differential equation + +associated with the open-loop +system, the basic dynamics of + +the system. + +And if we apply the Laplace +transform to this equation and + +solve for the system function, +then the basic equation that + +we're left with expresses the +Laplace transform of the + +angle, equal to the system +function, the open-loop system + +function, times the Laplace +transform of + +the combined inputs. + +And I remind you again that our +assumption is that this is + +an input that we have +no control over. + +This is the input that +we can control. + +And the two together, +of course, form + +the combined input. + +Now, we can, of course, solve +for the poles and 0's. + +There are no 0's. + +And there are two poles, since +this is a second-order + +denominator. + +And looking at the poles in the +s-plane then, we see that + +we have a pair of poles, one at +minus the square root of g + +over L, and one at plus the +square root of g over L. + +And the important observation, +then, is that while this pole + +represents a stable pole, the +right half-plane pole + +represents an unstable pole. + +And so this system, in fact, +is an unstable system. + +It's unstable because what we +have is a pole in the right + +half-plane for the +open-loop system. + +Now, before we see how to +stabilize the system, let's, + +in fact, look at the mechanical +setup, which we + +won't turn on for now, and just +see essentially what this + +instability means and what the +physical orientation of the + +equipment is. + +So what we have, which you just +saw a caricature of in + +the view graph, is an +inverted pendulum. + +This represents the pendulum. + +And it's mounted with the pivot +point at the bottom. + +It's mounted on a cart. + +And here we have the cart. + +And this is a pivot point. + +And, as you can see, the +cart can move back + +and forth on a track. + +And the external acceleration, +which is applied to the cart, + +is applied through this cable. + +And that cable is controlled +by a motor. + +And we have the motor at +this end of the track. + +And so as the motor turns, +then the cart will + +move back and forth. + +OK. + +Now, since the system +is not turned on + +and there's no feedback-- + +in fact, the system, as we just +saw in the transparency, + +is an unstable system. + +And what that instability means +is that, for example, if + +I set the angle to 0 and then +let it go, then as soon as + +there's a slight external +disturbance, it + +will start to fall. + +Now, you can imagine that not +only is the system unstable as + +it is, but certainly can't +accommodate changes in the + +system dynamics. + +For example, if we change, +let's say, the + +weight of the pendulum. + +So if we thought, for example, +of changing the weight by, + +let's say, putting something +like a glass with something in + +it on top, and I think about +trying to balance it by + +itself, obviously that's hard. + +In fact, I would say, without +turning the system on, + +guaranteed to be impossible. + +So the basic system, as we've +just analyzed it, is + +inherently an unstable system. + +The instability reflecting in +the fact that the pendulum, + +following its own natural +forces, will tend to fall. + +And now what we want to look at +is how, through the use of + +feedback, we can, in fact, +stabilize the system. + +So let's first, once again, look +at the open-loop system. + +And the open-loop system +function that we saw was a + +system function of this form, 1 +over Ls squared minus g, and + +that represents the system +function associated with the + +two inputs, one being the +external disturbances, the + +other being the externally +applied acceleration. + +And the system function here + +represents the system dynamics. + +And the resulting output +is the angle. + +Now, the feedback, the basic +strategy behind the feedback, + +is to in some way use the +measured angle, make a + +measurement of the angle, and +use that through appropriate + +feedback dynamics to stabilize +the system. + +And so with feedback applied +around the system then, there + +would be some measurement of +the angle through some + +appropriately chosen +feedback dynamics. + +And that then would determine +for us the applied external + +acceleration corresponding to +what the motor does by pulling + +the cable back and forth. + +And we would like to choose +G of s so that the overall + +system is stable. + +Now, as you recall from the +lecture last time, with the + +feedback around the system and +expressed here in terms of + +negative feedback, the overall +transfer function then is the + +transfer function associated +with the basic feedback loop, + +where H of s is the open-loop +system and G of s corresponds + +to the feedback dynamics. + +Now, that's the basic +strategy. + +We haven't decided yet how to +choose the feedback dynamics. + +And that becomes +the next step. + +And we want to choose the +dynamics in such a way that + +the system ends up +being stabilized. + +Well, I think the thing to do is +just simply begin with what + +would seem to be the most +obvious, which is a simple + +measurement of the angle. + +Let's take the angular +measurements, feed that back, + +let's say through a +potentiometer and perhaps an + +amplifier, so that there's some +gain, and see if we can + +stabilize the system simply +through feedback which is + +proportional to a measurement +of the angle, what. + +Is typically referred to as +"proportional feedback." Well, + +let's analyze the results +of doing that. + +Once again we have the basic +feedback equation, where the + +open-loop transfer function +is what we had developed + +previously, given by the +second-order expression. + +Now, using proportional +feedback, we choose the + +acceleration a of t to be +directly proportional through + +a gain constant or attenuation +constant K1, directly + +proportional to the measured +angle theta of t. + +And consequently the system +function in the feedback path + +is just simply a gain +or attenuate K1. + +So this, then, is the +system function for + +the feedback path. + +Well, substituting this into +the closed-loop expression, + +then the overall expression for +the Laplace transform of + +the output angle is, as I +indicate here, namely that + +theta of s is proportional +through this system function. + +So the Laplace transform of the +input X of t-- and let me + +remind you that X of t, the +external disturbances, now + +represent the only input, +since the other input + +corresponding to the applied +acceleration to the cart is + +now controlled only through +the feedback loop. + +So we have this system function, +then, for the + +closed-loop system. + +We recognize this once again +as a second-order system. + +And the poles of this +second-order system are then + +given by plus and minus the +square root of g minus K1, + +divided by L. So K1, the +feedback constant, clearly + +influences the position +of the poles. + +And let's look, in fact, +at where the + +poles are in the s-plane. + +Well, first of all, with K1 +equal to 0, which, of course, + +is no feedback and corresponds +to the open-loop system, we + +have the poles where they +were previously. + +And if we now choose K1, let's +say less than 0, then what + +will happen as K1 becomes more +and more negative, so that + +this term is more and more +positive, is that the left + +half-plane pole will move +further into the left + +half-plane, the right half-plane +pole will move + +further into the right +half-plane. + +So clearly with K1 negative, +this pole, which represents an + +instability, becomes +even more unstable. + +Well, instead of K1 negative, +let's try K1 positive and see + +what happens. + +And with K1 positive, what +happens in this case is that + +the left half-plane pole moves +closer to the origin, the + +right half-plane pole moves +closer to the origin. + +What one would hope is that they +both end up in the left + +half-plane at some point. + +But, in fact, they don't. + +What happens is that eventually +they both reach the + +origin, split at that point, +and travel along the + +j-omega-axis. + +Now, this movement of the poles, +as we vary K1 either + +positive or negative, what we +see is that with the open-loop + +system, as we introduce +feedback, those basic poles + +move in the s-plane, either this +way, as K1 becomes more + +negative, or for this particular +case, if K1 is + +positive, they move in together, +split, and move + +along the j-omega-axis. + +And that locus of the poles, +in fact, is referred to in + +feedback terminology as the +"root locus." And as is + +discussed in much more detail in +the text, there are lots of + +ways of determining the root +locus for feedback systems + +without explicitly solving +for the roots. + +For this particular example, in +fact, we can determine the + +root locus in the most +straightforward way simply by + +solving for the roots +of the denominator + +of the system function. + +Now, notice that in this case, +these poles, with K1 positive, + +have moved together. + +They move along the +j-omega-axis. + +And before they come +together, the + +system is clearly unstable. + +Even when they come together +and split, the system is + +marginally stable, because, +in fact, the system + +would tend to oscillate. + +And what that oscillation +means is that with the + +measurement of the angles, +essentially if the poles are + +operating on the j-omega-axis, +what will happen is that + +things will oscillate +back and forth. + +Perhaps with the cart moving +back and forth trying to + +compensate, and the rod +sort of moving in + +the opposite direction. + +In any case, what's happened +is, with just proportional + +feedback, we apparently +are unable to + +stabilize the system. + +Well, you could think that the +reason, perhaps, is that we're + +not responding fast enough. + +For example, if the angle starts +to change, perhaps, in + +fact, we should make the +feedback proportional to the + +rate of change of angles, +rather than + +to the angle itself. + +And so we could examine the +possibility of using what's + +referred to as "derivative +feedback." + +In derivative feedback, what we +would do is to choose, for + +the feedback equation, or for +the feedback system function, + +something reflecting a +measurement of the derivative + +of the angle. + +And so here again, once again, +we have the open-loop system + +function with derivative +feedback. + +We'll attempt to-- + +or we will use this feedback. + +And acceleration, which instead +of being proportional + +to the angle, as it was in the +previous case, an acceleration + +which is proportional to the +derivative of the angle. + +And so the basic feedback +dynamics, or feedback system + +function, is then G of s +is equal to K2 times s. + +The multiplication by s +reflecting the fact that in + +the time domain it's measuring +the derivative of the angle. + +The associated system function +is then indicated here. + +And if we solve again this +second-order equation for its + +roots, that tells us that the +location of the poles are + +given by this equation. + +And so now what we would want to +look at is how these poles + +move as we vary the derivative +feedback constant K2. + +So let's look at the root +locus for that case. + +And first, once again, we have +the basic open-loop poles. + +And the open-loop poles consist +of a pole on the left + +half-plane and a pole on +the right half-plane, + +corresponding in this equation +to K2 equal to 0. + +That is, no feedback +in the system. + +If K2 is negative, then what you +can see is that this real + +part will become +more negative. + +Since K2 is squared here, this +is still a positive quantity. + +And, in fact, then with K2 less +than 0, the root locus + +that we get is indicated +by this. + +Now, notice, then, that this +right half-plane pole is + +becoming more unstable. + +And the left half-plane +pole likewise is + +becoming more unstable. + +And this point, by the way, +corresponds to where this pole + +ends up, or where the root +locus ends up, when K2 + +eventually becomes infinite. + +So clearly K2 negative is not +going to stabilize the system. + +Let's try K2 positive. + +And the root locus dictated by +this equation, then, is what I + +indicate here. + +The left half-plane pole moves +further into the left + +half-plane. + +That's good. + +That's getting more stable. + +The right half-plane pole is +moving closer to the left + +half-plane, but unfortunately +never gets there. + +And, in fact, it's when K2 +eventually becomes infinite + +that this pole just gets to +the point where the system + +becomes marginally stable. + +So what we found is that with +proportional feedback, we + +can't stabilize the system, with +the derivative feedback, + +we can't stabilize the system, +by themselves. + +And a logical next choice is to +see if we can stabilize the + +system by both measuring the +angle and at the same time + +being careful to be responsive +to how fast that angle is + +changing, so that if it's +changing too fast, we can move + +the cart or our hand +under the inverted + +pendulum more quickly. + +Well, now then what we want +to examine is the use of + +proportional plus derivative +feedback. + +And in that case, we then have a +choice for the acceleration, + +which is proportional with one +constant to the angle and + +proportional with another +constant to the + +derivative of the angle. + +And so the basic system +function, then, with + +proportional plus derivative +feedback, is a system function + +which is K1 plus K2 times s. + +We then have an overall +closed-loop system function, + +theta of s, which is given +by this equation. + +And so the roots of this +equation then represent the + +poles of the closed-loop +system. + +And those poles involve +two parameters. + +They involve the parameter K2, +which is proportional to the + +derivative of the angle, and +the constant K1, which is + +proportional to the angle. + +And we'll, first of all, examine +this just with K2 + +positive, because what we can +see is that as we vary K1, if + +K2 were negative, that would, +more or less immediately, put + +poles into the right +half-plane. + +And the more negative K2 +got, the larger this + +term is going to get. + +So, in fact, as it will turn +out, we can stabilize the + +system, provided that +we choose K2 to be + +greater than 0. + +All right. + +Now, with K2 greater than 0, +what happens in the location + +of the poles is that if K2 is +greater than 0, and we choose + +K1 greater than 0-- + +I'm sorry. + +We choose K1 equal to 0, then in +effect the influence of K2 + +is to shift the poles of the +open-loop system slightly. + +And so with K2 greater than 0 +and K1 equal to 0, we have a + +set of poles, which are +indicated here, and so this is + +just a shift, slight shift, to +the left, depending on the + +value of K2, a shift to the left +of the open-loop poles. + +Now, as we vary K1, and in +particular we're going to + +choose K1 greater than 0, what +happens is that the poles will + +begin to move together, as they +did previously when we + +looked at the variation of K1. + +The poles will move together, +reach a point where we have a + +second-order pole, and then +those poles will split and + +move parallel to the +j-omega-axis. + +So what's indicated here +is the root locus. + +And what this represents, then, +as long as we make K1 + +large enough so that this poles +moves into the left + +half-plane, is that +it represents + +now a stable system. + +OK. + +So what we've seen is that +proportional feedback by + +itself or derivative feedback by +itself won't stabilize the + +system, whereas with the right +choice of feedback constants, + +proportional plus derivative +feedback will. + +And we saw that basically by +examining the root locus in + +the s-plane. + +All right. + +Well, let's actually watch +the system in action. + +And I described it to +you previously. + +Basically, an inverted +pendulum on a cart. + +And so I still have it off. + +And, of course, we have +the pendulum. + +And as I indicated, it's +pivoted at the base. + +And the angle is measured by a +potentiometer that we have + +attached to the pivot point. + +And the measurement of the angle +is fed back through this + +wire to a motor that we have at +the other end of the table. + +And then that motor basically +is used to provide the + +acceleration to drive +the cart. + +OK. + +Well, let's turn it on. + +And when we turn it on, +it'll take just + +an instant to stabilize. + +And fortunately we have the +constants set right, and there + +we have now the stabilization +of an unstable system. + +Remember that with the feedback +off, the system is + +unstable because the pendulum +will fall, whereas now it's + +stabilized. + +Now, also, as you can see, not +only have we stabilized it, + +but we're able to compensate +through the feedback to + +changes in the external +disturbances. + +For example, by tapping it, +because of the feedback and + +the measurement of the angle, +it will more or less + +automatically stabilize. + +Now, in addition to being stable +in the presence of + +external disturbances, it also +remains stable and remains + +balanced even if we were to +change the system dynamics. + +And let me just illustrate that +with the glass that we've + +talked about before. + +Let's first not be too bold, and +we'll take the liquid out + +of the glass. + +And presumably if it can adjust +to changes in the + +system dynamics, then if I put +the glass on, in fact, it will + +remain balanced. + +And indeed it does. + +And let me point out, by the +way, that I don't have to be + +very careful about exactly where +I position the glass. + +And furthermore, I can change +the overall system even + +further by, let's say for +example, pouring a liquid in. + +And now let me also comment that +I've changed the physics + +of it a little bit. + +Because the liquid can slosh +around a little bit, it + +becomes a little more +complicated a system. + +But as you can see, it still +remains balanced. + +Now, if we really don't want to +be too conservative at all, + +we could wonder whether, with +the feedback constants we + +have, we could, in +fact, balance the + +pitcher on the top. + +And, well, I guess we may +as well give that a try. + +And so now we're changing the +mass at the top of the + +pendulum by a considerable +amount. + +And, again, the system basically +can respond to it. + +Now, this is a fairly +complicated system. + +The liquid is sloshing around. + +We, in fact, as you can see, +have an instability right now, + +although it's controlled. + +And that's because the physics +of the dynamics has changed. + +And we can put a little bit more +mass into the system, and + +maybe or maybe not that will cut +down on the instability. + +OK. + +Well, in fact, what happened +there is that we increased the + +mass at the top of the +pendulum slightly. + +And that provided just +enough damping to + +stabilize the system. + +OK. + +Well, with this lecture and +this demonstration, this + +concludes this entire +set of lectures. + +It concludes it especially if +the pitcher happens to fall. + +But, seriously, this concludes +the set of lectures as we have + +put them together. + +And let me just comment that, +as a professor of mine once + +said, and which I've never +forgotten, the purpose of a + +set of lectures, or of a course, +or, for that matter + +anything that you study, is not +really to cover a subject, + +but to uncover the subject. + +And I hope that, at least to +some degree, we were able to + +uncover the topic of signals +and systems through this + +series of lectures. + +There are a lot of topics that +we got only a very brief + +glimpse into. + +And I hope that at least what +we've been able to do is get + +you interested enough in them so +that you'll pursue some of + +these on your own. + +And so I'd like to conclude by +thanking you, both for your + +patience and your interest. + +And I hope that you have enough +interest to pursue some + +of these topics further. + +Thank you. + +FILMING DIRECTOR: Okay. + +That's a wrap. \ No newline at end of file diff --git a/EYANqW4zwwo.txt b/EYANqW4zwwo.txt new file mode 100644 index 0000000000000000000000000000000000000000..37cb76087e9f219423bfb7ce8cc4d46956bfcd01 --- /dev/null +++ b/EYANqW4zwwo.txt @@ -0,0 +1,4276 @@ +ANNOUNCER: The following content +is provided under a + +Creative Commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high quality educational +resources for free. + +To make a donation or to view +additional materials from + +hundreds of MIT courses, visit +MIT OpenCourseWare at + +ocw.mit.edu. + +MICHAEL KREMER: So I understand +that in the session + +that you just had, you went +through the deworming case. + +And I was just talking to some +people in the break, and they + +were saying that everything's +been very focused on methods, + +which is understandable. + +That's what the purpose +of the course is. + +But it sounded like people were +interested in hearing a + +little bit about the substantive +results. + +So I just thought before I +launched into this lecture, + +I'd say a little +bit about that. + +And maybe this is also a way +to give you a little bit of + +background on where +I'm coming from. + +So I taught secondary school in +Kenya right after college + +and then went to grad school. + +And then I went back after +graduating, from getting my + +Ph.D. and getting a real job +and having some money. + +I eventually went back to +visit some friends. + +And one of them was working +for an NGO, which was just + +starting work in +western Kenya. + +And his job was to find seven +schools to start a program in. + +And I said to him, not really +thinking this was something + +that he would do, "Why don't +you pick twice as many and + +choose the seven randomly, at +least where you're going to + +start?" And much to my surprise, +he was interested. + +And then he went to his boss, +and his boss actually did it. + +So that's, in part, how this +wave of randomized evaluations + +with NGOs got going. + +This NGO worked a lot +on education. + +And over the years, we tried a +number of things to try to get + +more kids in school and stop +kids from dropping out. + +But eventually, they tried +treating kids for worms. + +And part of this was based on +reading the literature which + +suggested that this is an +important health intervention. + +There was a question, would +it have education effects. + +So it turned out, of all the +various things that we looked + +at, we calculated what was the +cost per additional year of + +schooling generated. + +So we're comparing a bunch +of things in that same + +environment in western Kenya. + +And deworming came out an order +of magnitude better than + +anything else. + +So this was a really +striking result. + +If you spent $3.50, you could +generate an additional year of + +education for a child. + +It was just much cheaper than +any of the other alternatives. + +So we had that academic +result. + +There were people at the World +Bank who were very + +interested in this. + +There's a lot of heterogeneity +in the Bank, but a lot of + +people there who are very +interested in and understand + +evidence or are interested +in or responsive to it. + +And the particular people who +are working on health and + +education sector in the Bank +in Kenya, that very much + +applies to. + +So they then took it to the +Ministry of Education and + +brought us in to talk +to the people in + +the Ministry of Education. + +This process took quite +a lot of time. + +I don't want to underestimate +this. + +Took a lot of time. + +The first time, they said, these +results are interesting, + +then, yes, we should +pursue them. + +But there's a lot going on +inside the Ministry of + +Education, lots of +other priorities. + +There are teacher strikes. + +There's all sorts of +things that have + +to take higher priority. + +But both externally, outside +in international fora and + +academic fora, and internally +inside Kenya, we kept + +bringing this up. + +And eventually, the permanent +secretary, who's very strong, + +the permanent secretary of the +Ministry of Education said, + +let's do this. + +And he brought in +various people. + +And they decided they were +going to try to implement + +this, have a national +scale up of this. + +And there was both that internal +persuasion of people + +within the Ministry +of Education. + +And then, of course, there's +the question of + +getting budget for it. + +Obviously, having the World Bank +on side helped on that. + +The other thing that +we did was-- + +so Esther and I were both +involved in an event the World + +Economic Forum put +on in Davos. + +And working with that group, +we were able to arrange for + +there to be an event in Davos +on this issue of deworming. + +And we helped start an +organization called Deworm the + +World which was designed +to promote this. + +And we invited the +prime minister of + +Kenya to come speak. + +And he made this announcement. + +And I think that helped drive +this forward a lot. + +Because once you got a public +announcement by a politician, + +then it's really going +to happen in a way. + +So between the support +internally within the ministry + +and this higher level political +support, Kenya has, + +just as we speak, just in the +past few months, dewormed + +almost 3 million children. + +So this is an example of how, if +you can identify successful + +intervention, it can really help +promote scale-up of the + +successful interventions. + +Ultimately, that's the purpose +of what we're doing is trying + +to improve policy. + +So I just wanted to give you +that tie-in to reality before + +plunging back into +econometrics. + +Any comments or questions +on that? + +AUDIENCE: I thought it was +really interesting. + +Could you just give +us a couple of the + +year points in that? + +You talked about things +taking a long time. + +Can you give more concrete +evidence? + +MICHAEL KREMER: Our article +appeared, and publishing the + +article takes a long time too. + +Our article appeared +in 2004, I believe. + +It's now 2009, and this +is happening now. + +The NGO responded much +more quickly. + +Although eventually, +they changed + +their strategy as well. + +So the NGO scaled up. + +But to get the national +government to scale up, I + +think that took a + +constellation of various people. + +It took some time for this to +get in the media, to get in + +the academic world, to get out +to the media, to get out to + +opinion leaders, both +internationally. + +And then it took time for the +right set of people to be + +available and the money to +be available to do it. + +Yes? + +AUDIENCE: Just kind of +following up on that. + +This is a issue that is +obviously quite concerning, + +the bridge between academia +and the policy world. + +And the fact that this research +is absolutely + +fabulous, but then, at +the end of the day, + +it stays in a textbook. + +And what use is it +to beneficiaries? + +This example is, again, +fabulous. + +But what sort of actions or +roles are there to extend + +findings into the policy +world and into + +the development world? + +I'm sure that's a big topic. + +But just very briefly, is J-PAL +or sister organizations + +doing that sort of extension? + +MICHAEL KREMER: In this +particular case, I would say + +that I spent a fair amount of +time afterwards trying to + +disseminate this. + +And J-PAL has been very +important in starting to + +deworm the world. + +I think this requires effort at +a variety of levels, both + +in trying to get the prime +minister on board, but also in + +trying to do tasks like, well, +you need a spreadsheet of + +where are all the schools in the +country, and which ones of + +them are in areas where we think +that there's worms, and + +working out a bunch of logistics +of, well, how many + +trainers do you need, +and so on. + +Now I think in different +settings, they'll be-- + +in this one, people who are +at J-PAL and IPA have been + +involved in even down to +that spreadsheet level. + +That may not be the +case all the time. + +I think it depends a lot on +the particular government. + +I think, obviously, J-PAL +is primarily a academic + +organization. + +And so it's not the right +organization to manage the + +actual roll out. + +But where you draw the line, +it's a difficult question. + +But I also-- + +Yes. + +AUDIENCE: [INAUDIBLE]. + +MICHAEL KREMER: No, go ahead. + +AUDIENCE: So it seems like that +the deworming medication + +is really cheap, and it's +a very easy treatment. + +Have you looked at other types +of diseases and using the + +school system to try +and manage it? + +MICHAEL KREMER: Yeah. + +So there are other things which +could be done in the + +school health area +and perhaps with + +micronutrients, et cetera. + +I don't want to go too far there +both because I want to + +get back to the econometrics and +because I know more about + +worms than I do other things. + +But I think there are +micronutrients and other + +things that could be +delivered that way. + +There's some work that's been +done on presumptive treatment + +for malaria that is very +intriguing and suggests that + +might work. + +There's also things you can +do on education, HIV/AIDS + +education, and so on. + +Pascaline Dupas does some +very nice work on that. + +And then Esther and Pascaline +and Samuel Sinei and I have + +some joint work on +that as well. + +OK. + +Well, let me turn to the topic +of this lecture, which is-- + +and I'm happy if there's time +at the end or in the break, + +I'm happy to follow up +on these issues-- + +which is managing threats to + +evaluation and to data analysis. + +So I think in the previous +discussion, there's been + +things about how do you set up +your sample size, how do you + +actually randomize. + +Doing those things is obviously +critical, but it + +might not be sufficient. + +Because there can still be +problems with impact + +measurement and analysis. + +Some of those, you can try to +minimize ahead of time. + +I'm going to focus mostly +on what can be + +done ahead of time. + +And then Shawn's going to talk +about what can be done in the + +analysis stage to try and deal +with problems that did come + +up, and what inferences you can +make, and what inferences + +you can't make. + +I'm going to do a small, +semi-randomized trial here, + +quasi-randomized trial, +I guess should say. + +I'm going to consider a program +which is giving people + +money as a social, anti-poverty +program. + +I think, rather than do +full randomization-- + +you can actually leave that +down for awhile-- + +I'll come back to the +evaluation of + +this program later. + +Now I'm going to do the +randomization and the + +implementation. + +And we can do the-- + +AUDIENCE: Too late. + +MICHAEL KREMER: OK. + +Too late? + +OK, that's fine. + +We could count off people, one, +two, one, two, and then + +just give all the ones $500 +and the twos nothing. + +AUDIENCE: It really does +feel bad when you're + +in the control group. + +AUDIENCE: No sharing. + +[UNINTELLIGIBLE]. + +AUDIENCE: This is real +money or this-- + +MICHAEL KREMER: Don't worry. + +Well, you shouldn't feel +too bad if you're + +in the control group. + +AUDIENCE: I meant +cash or money? + +MICHAEL KREMER: You've got +the money now, yeah? + +AUDIENCE: [UNINTELLIGIBLE] +cash? + +MICHAEL KREMER: Yeah, they'll +be opportunities later on. + +OK, here are the problems +I want to discuss. + +The first one is-- + +so hang on to this money, we'll +deal with it later on-- + +the first one is attrition. + +The second is externalities. + +And the third one is +partial compliance. + +So the first one is attrition. + +Some people you're not able to +collect follow up data on. + +You try, but you're +not able to. + +The second one, externalities. + +What happens if your program, +as in the case of deworming, + +winds up affecting the +comparison group as well as + +the treatment group? + +And the third one is +partial compliance. + +You want to implement in certain +places, but some + +places, they don't actually +implement it. + +Maybe some of your +comparison group + +accidentally gets treated. + +What do you do in that case? + +All of these things are really +about internal validity. + +So there's important questions +of external validity and + +interpretation. + +And Shawn's going to talk +to some about those. + +But I'm going to just +focus on the + +internal validity of these. + +So the first question with +attrition is is it going to be + +a problem if some of the people +disappear before you + +can collect the data. + +And this can be a real problem +in Kenya for example. + +Kids often change their name. + +So it's just a part +of the culture. + +You change your name +at some point. + +That's going to make it +difficult to find everybody + +afterwards. + +So a first question-- oh gosh, +I thought this was going to + +come up bit by bit. + +Well, OK. + +We got the whole slide. + +So is it a problem if the type +of person who disappears is + +correlated with the treatment? + +And does anybody want to +answer that even though + +there's some answer there? + +This says the name of it, +but it's not saying + +what the issue is. + +Does anybody want to +comment on that? + +Yes. + +AUDIENCE: So if the attrition +is quantited with treatment, + +then you're going to end up +with underestimated or + +overestimated effect depending +on what the correlation is. + +MICHAEL KREMER: OK. + +That's great. + +Can you say more about that? + +AUDIENCE: So if the correlation +is that the people + +who disappear are people who +didn't get the treatment, who + +most needed the treatment, then +what you're left with in + +the control group is stronger +people, the people who maybe + +didn't need the treatment as +much or maybe had other + +reasons that they were +doing just fine. + +And so it's going to look like +the treatment effect is less + +because you have a strong +control treatment group + +compared to a randomized +treatment group. + +MICHAEL KREMER: Right. + +OK. + +So that's great. + +So let's go through an example +where we can potentially see + +that sort of thing happening. + +So let's think about a problem +where there's some kids who + +don't come to school because +they're too weak, they're + +undernourished. + +So imagine that's the context. + +And imagine you start a school +feeding program, and you want + +to do an evaluation of the +impact of this on school + +attendance. + +So this, in fact, was something +we wanted to do. + +And imagine you're interested +both in the impact on + +enrollment, but also on +children's nutrition, which + +you measure by their weight. + +And imagine that the real effect +of this program is that + +the weak, stunted children +actually go to school more if + +they're near a treatment +school. + +So if you go to all the schools +and you measure + +everyone who's in school on a +given day, in that case, are + +you going to see the treatment +and control difference in + +weight overstated +or understated? + +AUDIENCE: Overstated. + +MICHAEL KREMER: Overstated. + +So what's the story for why +it would be overstated? + +AUDIENCE: Because in the +treatment schools, a lot of + +kids who really need +the nutrition + +would start going in. + +Whereas, in the control group, +they have no incentive to go. + +So they're not being +included in it. + +MICHAEL KREMER: That's +interesting. + +That's interesting. + +OK, OK. + +In fact, the example is going +to be the opposite. + +But I think it's true, you could +tell a story where this + +could go either way. + +And you just told a story where +it would go that way. + +Let's show you a hypothetical +numerical example. + +And if you can actually +work through this, + +that would be useful. + +Imagine there's just three +kids in each of these + +communities. + +So imagine that before +treatment, the distribution + +looked identical. + +So there was one kid who weighed +30 kilos, another at + +35, another at 40. + +And after treatment, let's say +it's a successful program, and + +it gets everybody up +by two pounds-- + +I guess we should do this in +pounds given these numbers-- + +moves everybody up +by two pounds. + +In the comparison group, +everybody stays the same. + +So when you calculate, the +average here is going to be + +35, and here it's +going to be 35. + +So there's going to be no +difference at baseline. + +If you look afterwards, if you +didn't have any attrition and + +you managed to follow all +these kids, you would + +correctly measure the impact +of this program. + +You would say that it's added +two pounds to people's weight. + +Now here's one possible +pattern of attrition. + +Suppose you go on a given day, +but not all of the kids are + +there that day. + +So in particular, imagine that +the weaker kids are less + +likely to be there. + +So suppose only children who +are more than 30 kilograms + +come to school. + +Imagine the kids who are less +than 30 kilograms are only + +there half the time +or something. + +And you happen to show up on a +day when kids who are only + +over 30 kilograms +come to school. + +Well, then the person who is +still at 30 kilograms in the + +comparison group isn't going +to be there at all. + +You'll measure the average +here at 37 and a half. + +So you'll see no difference +beforehand. + +Afterwards, can you compute what +you're going to estimate + +the impact of the +treatment to be? + +Yeah. + +AUDIENCE: It's negative +half a pound. + +MICHAEL KREMER: Negative +half a pound, right. + +So in this case, for this +particular set of assumptions, + +you'll underestimate +the impact. + +It's not necessarily the case +that attrition differences + +between the groups always +lead to underestimates. + +It can be the opposite. + +So we happened to pick a case +here where it worked this way. + +But here's another example. + +Let's put that other +context behind us. + +Think about a different +context. + +Think about the context +of we're just + +trying to improve learning. + +And we've got a new +math course. + +And it's a hard course. + +For example, in the state of +Massachusetts, there are now + +graduation requirements. + +Used to be that it was very +easy to graduate from + +secondary school. + +They put in requirements to +make this much tougher. + +You have to pass an exam. + +And the proponents of this +argue, well, it's a good thing + +because it forces the kids to +study more, it forces the + +teachers to really +prepare them. + +And they're probably right. + +The opponents argue that, well, +the kids who figure + +they're not going to be able +to pass just drop out. + +They may be right as well. + +So if you're trying +to evaluate the + +impact of this program-- + +and imagine that we randomized +across states in the US, and + +some states implemented, +and some didn't-- + +if you looked at the average +score among those who got + +through, well, you might +see it's better in + +the treatment group. + +But would that be the right +conclusion about the impact of + +the program? + +It might not be. + +So let me keep going +with this. + +So we've got this +harder course. + +Imagine those who can't +handle it drop out. + +You give the same +math test in the + +treatment and control schools. + +But you only have data on those +who didn't drop out + +because you go to the school +and you get everybody who's + +there in the school. + +So what's the direction +the bias is going + +to be in that case? + +AUDIENCE: It'll overstate +the effect. + +You'll only see the strongest. + +MICHAEL KREMER: Exactly, +exactly. + +In the treatment group, you'll +only see the strong students. + +In the comparison group, +you'll have the mix. + +So that's an example of +the case that you + +were talking about. + +In the deworming program with +testing, what was the natural + +concern with attrition +bias there? + +AUDIENCE: The weakest, the +ones with the most worms + +weren't going to be-- + +MICHAEL KREMER: Exactly, +you get them to stay. + +The kid's pretty weak because +they've had lots of worms. + +You cut off the worms, +they come to school. + +So the treatment group would +then be adding in these kids + +who are weaker in some way. + +So that would be the concern. + +How do you deal with it? + +Well, one way is you can try +to follow everybody up. + +And this is the first thing +you should do is the brute + +force approach, which is to try +and follow everybody up. + +And that means if it's a school +program, maybe you + +don't just test the kids in +the school, the ones who + +dropped out, you try and find +them and test them anyway. + +Now that's expensive. + +And it's very difficult to find +people, and it may be + +difficult to get them +to take the exam. + +But if you think that the +program is going seriously + +affect dropout rates, then that +can be a very important + +thing to do. + +To do that, you have to pick a +sample of those who are going + +to be tested before the +treatment, and you have to + +follow those people. + +So if you hadn't done a +baseline, then this is going + +to be especially hard because +you don't even know who + +dropped out. + +They might not have records +of those kids. + +There's sometimes questions. + +Should you do a baseline, +or should you not? + +In theory, you could do a +randomized evaluation without + +a baseline. + +Almost always, it's much better +to have the baseline. + +And this is one of them, which +is if the program might affect + +dropout, you want to measure the +effect of the program by + +looking at the people who were +initially in the program. + +So then imagine that you do +that, but the truth is it's + +just hard to find all these +kids who dropped out. + +Some of them have moved, or +they're not home, or whatever, + +or they don't want to +come take the test. + +So imagine that you've done +this, and the treatment group + +has 20% attrition, +the comparison + +group has 20% attrition. + +Are you then OK? + +OK. + +I'm seeing the answer, no. + +Does anybody want to say +what the potential + +problem might be? + +Yeah. + +AUDIENCE: Well, if it's not +random as to who drops out, + +then we're just still going to +have to [UNINTELLIGIBLE] + +facts. + +If there's still a correlation +between who's dropping out in + +the control group versus who's +dropping out in the treatment + +group, that's still going +to affect the outcomes. + +MICHAEL KREMER: Yeah. + +That's exactly right. + +I'm trying to think +of this myself. + +Can anybody come up with a +hypothetical, but concrete + +example, where you could have +the same attrition rate in the + +two groups, but your estimate +would still be messed up or + +biased, to use the +technical term? + +Yeah. + +AUDIENCE: For example, if the +treatment group is only the + +[UNINTELLIGIBLE] + +could drop off and then +the control group is + +[? losing flow ?] + +would drop off, it's not going +to [UNINTELLIGIBLE]. + +MICHAEL KREMER: Exactly, +exactly. + +So if, in each case, you lose +20%, but in the treatment + +group, you're losing the top 20% +and the comparison group, + +you're losing the bottom 20%, +and you only measure those who + +remain, you're going +to be biased. + +So here's an example of +something that could do that. + +Imagine that you put in a +remedial education program. + +Imagine you lower the levels +of the curriculum. + +Well, then maybe the kids in the +treatment group, maybe the + +kids who are at the top of the +distribution say, I don't want + +to be in this school, I'm +switching to another school, + +because they don't want the +lower level curriculum. + +So you lose 20%. + +In the comparison school, the +20% at the top don't drop out, + +but the 20% at the bottom drop +out because they didn't have + +this special attention. + +So in each case, you've got +20% attrition, but the + +estimate of the impact of the +program is going to be very + +seriously biased. + +So how can you deal with that? + +Well, what you should do +is you should check + +whether you have a-- + +imagine you had pre-test +scores for the kids. + +Well, then you could see what's +the predictors of drop + +out in the treatment group and +in the comparison group. + +And ideally, you'd find the +predictors are the same. + +And then you're somewhat +reassured. + +You're not completely, +completely safe because maybe + +your initial test scores aren't +really a good measure + +of their true eventual +test score. + +But it helps a lot. + +The other thing you can do is +you can try to bound the + +extent of the bias. + +So we go through an exercise +like this in + +the deworming paper. + +So suppose everyone who dropped +out of the treatment + +got the lowest test score +that you got. + +So what you can do is you can +say, we're going to put those + +people for whom we don't have +outcome data, we're going to + +create an artificial data set, +where we put them back in the + +data, but we artificially +assign them the lowest + +conceivable score. + +And then suppose everybody who +dropped out of the control + +group got the highest score +that anybody could get. + +So if you artificially give +everybody who dropped out of + +treatment the lowest possible +score, and you artificially + +give everybody who dropped out +of the control group the + +highest possible score, well, +then you're bending over + +backwards to say, how bad +could the program + +potentially have been. + +And if you do this exercise and +you find that even when + +you do this, it looks like the +program is good, then you can + +be pretty confident the +program's good. + +So this is what's called +constructing the lower bound. + +And similarly, you can construct +an upper bound on + +how well the program did. + +And if you have a high dropout +rate, your lower bound and + +your upper bound are going +to be very far + +apart from each other. + +You're not going to be able to +say that much about what the + +impact of the program is. + +But if you have a low dropout +rate, it might be that your + +bounds are very close +together. + +AUDIENCE: And cheaper. + +MICHAEL KREMER: It's cheaper +than fighting everybody, yeah. + +I think a lot depends on +the particular context. + +And there's also various +bounds you can do. + +So let me not go into the +full detail on that. + +But you can have bounds that +are very conservative. + +This would be an example of +them, where this is very much + +a worst case scenario. + +You can imagine other scenarios +that are not the + +very worst case scenario, but +are pretty bad case scenarios, + +and say, even in that case, the +program would have worked. + +The next topic is going +to be externalities. + +But before I go on to that, do +people have questions on + +attrition or comments on it? + +Or questions about +this in practice? + +OK, let me move on +to externalities. + +So first, I want to create +some externalities. + +So everybody who got +some money-- + +I heard a suggestion of +sharing some money. + +So why don't we implement +that? + +So why don't you turn to your +neighbor, and why don't you + +share some of the money +with your neighbor? + +I'll let you decide how generous +you want to be. + +It is fake money after all. + +AUDIENCE: Can we give to +multiple neighbors? + +MICHAEL KREMER: Do whatever +you like, do + +whatever you like. + +And by the way, what you guys +just did, there are a lot of + +theories of development-- + +I don't know whether this is +practice or not-- which would + +say that that sort of thing +might happen, a lot of + +theories about risk sharing +within communities, and so on. + +Maybe that's all propaganda, +I don't know. + +But anyway, some people would +claim that that sort of thing + +can happen. + +So now what I want to talk about +though is what's the + +impact on our program +evaluation. + +What I'd like to do is to do a +program evaluation now of what + +was the impact of this +program, where + +you're all a village. + +I gave half the people +in the village $500. + +So how did we do that? + +Well, we pseudo-randomized the +program, reasonably close, + +counting off one, two. + +What's the impact +of the program? + +Well, let's figure out how much +money our treatment group + +people have and our comparison +group people have. + +So if you can look in your +wallet, figure out how much + +money you have there, add in +the fake money, and come up + +with a total. + +And then we'll try +and do some-- + +I'll do some data collection. + +So let me put this up here. + +AUDIENCE: Our actual money? + +MICHAEL KREMER: Yeah, add in +your actual money and your + +fake money, and we'll see. + +So are you a treatment +group person? + +AUDIENCE: Yes. + +MICHAEL KREMER: OK. + +So how much money do you have, +including everything? + +AUDIENCE: $784. + +MICHAEL KREMER: $784, OK. + +I hope there's no thieves +around here that I'm + +revealing things to. + +AUDIENCE: $784? + +AUDIENCE: Including this. + +AUDIENCE: Because I'm +a control group. + +MICHAEL KREMER: You're +a control group. + +AUDIENCE: I have $300. + +MICHAEL KREMER: $300. + +AUDIENCE: [? Only money ?] +pounds [? away ?]. + +AUDIENCE: But these guys +gave it to you. + +AUDIENCE: It was on your Charlie +card or whatever. + +MICHAEL KREMER: So how +much do you have? + +AUDIENCE: $407. + +MICHAEL KREMER: $407. + +And you're a treatment, right? + +AUDIENCE: I got $14 and +$1 on my Charlie card. + +MICHAEL KREMER: OK. + +So $15, we'll call it. + +AUDIENCE: $550. + +MICHAEL KREMER: $550. + +Maybe the second row +should just come up + +and write on here. + +AUDIENCE: $140. + +MICHAEL KREMER: Sorry? + +AUDIENCE: $140. + +MICHAEL KREMER: $140. + +AUDIENCE: $428. + +MICHAEL KREMER: $428. + +AUDIENCE: $318. + +MICHAEL KREMER: $318. + +AUDIENCE: $698. + +MICHAEL KREMER: I'll +put this here. + +AUDIENCE: $263. + +MICHAEL KREMER: And are +you a one or a two? + +AUDIENCE: I'm $500, I +don't know what-- + +MICHAEL KREMER: So +you're group one. + +And sorry, what was +the number again? + +AUDIENCE: $263. + +MICHAEL KREMER: $263. + +You're a very generous guy at +least with fake money, right? + +AUDIENCE: $270. + +MICHAEL KREMER: Oh, $270. + +Looks like the program was + +counterproductive in your case. + +We had a negative seven +effect on income. + +AUDIENCE: I have $227. + +MICHAEL KREMER: $227. + +AUDIENCE: $500. + +MICHAEL KREMER: $500. + +You know what? + +We could go and do the full +sample, but maybe we should-- + +well, we'll take two more. + +AUDIENCE: $700. + +MICHAEL KREMER: I'm sorry, +which group are you? + +AUDIENCE: Treatment. + +MICHAEL KREMER: $700, OK. + +AUDIENCE: I'm control, +and I have $200. + +MICHAEL KREMER: $200? + +Oh, so that got the-- + +We'll just take a partial sample +rather keep going. + +Let's try and get the average in +the treatment group and the + +average in the comparison +group. + +AUDIENCE: The average in the +treatment group is 507 or 8. + +MICHAEL KREMER: 508. + +AUDIENCE: And the average in +the control group is 249. + +MICHAEL KREMER: 249. + +So now we do our evaluation. + +And we go through, and +we say, OK, we + +gave out $500 to people. + +Now we've gone back to see how +they're doing, compare them to + +the comparison group. + +And it looks like they're +$259 richer. + +So did the program work? + +Well, the program worked. + +But was it cost effective? + +Not really. + +Because we gave them $500. + +They're only $250 approximately +richer. + +This really wasn't +a big success. + +AUDIENCE: Well-- + +MICHAEL KREMER: Go ahead. + +AUDIENCE: That's only one way +of looking at it, right? + +MICHAEL KREMER: Exactly. + +That's one way of +looking at it. + +If you came with that +conclusion, you'd be missing a + +really important dimension +of what the impact + +of the program is. + +Certainly, if you're a policy +maker who's mostly concerned + +about what's the impact on the +community, not what's the + +impact on the particular +individual I gave it to, then + +you'd basically have a very +misleading answer. + +So that's the danger. + +The topic of this lecture +is what are threats. + +And this is a threat. + +You misunderstand the impact +of the program because you + +haven't adequately accounted +for the externality. + +That's the problem. + +Let me now talk about what can +you do about that problem. + +So let me look at this in the +context of deworming. + +Then maybe we can come back +to this example again. + +So in the case of deworming, +a lot of the earlier work + +randomized deworming treatment +within schools. + +So the problem is that when +you are dewormed, that may + +interfere with the transmission +of the disease. + +If the treatment kills the worms +in your body, that means + +the worms are no longer laying +eggs, they're no longer being + +spread in the community +as much. + +So what's the problem that +that's going to create for the + +evaluation? + +AUDIENCE: You're going to see +benefits in the control group. + +MICHAEL KREMER: Right. + +You could see benefits in the +control group, just as this + +cash example. + +In this particular case, we +argue that those benefits + +might not just have affected +kids who go to that school, + +but might have also affected +neighboring schools as well. + +But let's start out with the +analytically simpler case. + +Suppose the benefits +are local. + +So suppose you only shared money +with your neighbors, but + +you don't share money with +people in another classroom in + +engineering or something +like that. + +And how can you measure the +total impact, the impact on + +the community as a whole +of the program? + +What could you do +in that case? + +AUDIENCE: You could phase in at +different rates to try and + +evaluate what would be the +impact of just having a + +peer-controlled peer treatment +and then try and figure out + +from the phase-in what +the impact of the + +externality would be. + +MICHAEL KREMER: So you +could phase it in. + +In this case, if the +externalities were local + +within a school or within a +classroom, in the case of this + +money example, you could phase +it in at the level of schools + +or of classrooms. + +And say, we're going to do +20% of the people in that + +classroom, 40% of the people in +this classroom, 60% of the + +people in that classroom. + +By the way, before I go further +with this, so there's + +an advantage of this-- well, +let me come back to this. + +I'm going to immediately assess +the advantage of this, + +but there's also +a disadvantage. + +So let's take this case where's +there's externalities + +within a school. + +So if we think about this +particular case, so imagine + +that there's no externalities. + +Pupil one is treated, +and the outcome is + +they don't have worms. + +Pupil two is not treated, but +they still don't have worms. + +Some people just don't +get the worms. + +Pupil three is treated. + +They don't have worms because +the medicine worked. + +Pupil four is not treated, +and they do have worms. + +Pupil five is treated, and +they don't have worms. + +Pupil six isn't treated, +and they do have worms. + +So in this case, where there's +no externalities going on, + +what's going to be the estimate +of the treatment + +effect here? + +AUDIENCE: 100% [INAUDIBLE]. + +MICHAEL KREMER: I'm sorry. + +You said 100%? + +Do you want to go through +the reasoning you're + +thinking up on that? + +AUDIENCE: [INAUDIBLE]. + +MICHAEL KREMER: So it's true +that nobody who is treated has + +worms because the +medicine works. + +So the total people in worms and +the treatment group with + +worms is going to be 0. + +So in that sense, you've +eliminated 100% of the group + +that does have worms. + +How many in the control group +are going to have worms? + +AUDIENCE: Three. + +MICHAEL KREMER: Three. + +So it depends how you define-- + +this is a big distinction +that people-- + +it's tedious, but it's important +to make when you + +write things up is percentage +effect versus + +percentage point effect. + +So percentage point is +the absolute value. + +So let me first do the +percentage point and then come + +back to the percent. + +So we have 0 people having it +in the treatment group. + +The total in the control with +worms, was that three if I + +remember right? + +OK. + +So 50% of people have it in the +control group, 0 have it + +in the comparison group. + +So it's a 50 percentage +point difference. + +The difference between 50 +percentage points and 0 + +percentage points. + +So one accurate way to write +this up would be say we had a + +50 percentage point +difference. + +Another way would be to say, +we eliminated 100% of the + +initial level. + +They're both accurate. + +It's just different ways +of expressing it. + +When you write things up, +the convention is to use + +percentage point for +the absolute value. + +So the treatment effect +would be 50 + +percentage points or 100%. + +But now suppose that you +actually do have + +externalities. + +So some children are not +reinfected with worms. + +So these worms have a life +cycle, so eventually the worms + +in you die. + +You have a high wormload because +you're continually + +being reinfected. + +So think about this example, +where some of the kids in the + +comparison group don't +get reinfected. + +Let's just think about the +percentage point effect for + +comparison. + +What are you going to estimate +the impact being in this case? + +AUDIENCE: 53? + +MICHAEL KREMER: Right. + +Did I just-- + +let's see this thing. + +Let me just do the-- + +I'm sorry. + +We didn't-- + +I think this other thing, +did we do the counting + +right in that one? + +AUDIENCE: Well, you said there +was 50% control with worms. + +And unless I'm misunderstanding +it, it looks + +like it's 100%. + +MICHAEL KREMER: Yeah, +that's right. + +Somebody had said 50, +and I didn't look. + +I just assumed that was +the right number. + +Let me just look at the nos. + +Yes, that's right. + +I'm sorry. + +It's 100% who have worms. + +Sorry, that was very +confusing. + +So now I see why you said-- it's +100% either way whether + +it's percentage points +or percent. + +You would have reached +that same conclusion. + +Let me just go back here just +to repeat, in case it wasn't + +clear to others like it +wasn't clear to me. + +So if the total in the treatment +with worms is 100% + +in this example, total in the +control with worms is 0. + +I think I must've got confused +in reading it in horizontal + +lines there. + +So in this case, the total +in the treatment + +group with worms is-- + +we still have 0 in the treatment +group with worms. + +And in the comparison group, +we've got 67%, 67%. + +So we're going to estimate +the treatment effect in + +this case being 67%. + +Now notice that this-- + +AUDIENCE: 130? + +Why? + +Oh, because it's +the difference. + +MICHAEL KREMER: The +difference, yeah. + +The difference between +100 and 67. + +Sorry, the hundred and-- + +see if we got this-- + +the hundred-- + +AUDIENCE: It's the total +[UNINTELLIGIBLE] + +0. + +MICHAEL KREMER: This is +0, and this is 67. + +So we've estimated 67% effect. + +So the thing to take away from +this is that if there were no + +externalities, we would have +estimated this correctly at + +100%, the effect +of the program. + +Now we say, suppose there are +externalities to this. + +So now that makes the program +actually better because more + +people are being cured of worms +through this program. + +But we're going to estimate the +effect of the program is + +actually lower. + +Instead of estimating the 100% +benefit, we'll estimate only a + +67% benefit. + +So how do you deal with that? + +Well, if you design the unit +of the randomization, so it + +encompasses all those +spillovers, that's one way to + +address this problem. + +So if you expected all the +externalities are within + +school, you can just randomize +at the level of the school. + +So here's another approach. + +And this is the actual data +from the program. + +The percentage of children +with a moderate or heavy + +infection in the treatment +schools was 27%. + +It was 52% in the comparison +schools. + +So the program reduced +moderate to heavy + +infections by 25%. + +This medicine probably affected +more kids initially. + +But if you go back and measure +a year later, some of them + +have been reinfected. + +You also got a reduction in the +number of kids who were + +sick and who are anemic. + +This is comparing one school +to another school. + +So we will have accounted for +the total impact of the + +program within schools if +there's within school + +spillovers. + +Suppose you wanted to actually +measure the spillovers. + +Suppose you were interested in +the spillovers themselves and + +not just the total impact. + +And you might well be. + +Imagine you are interested in +the question of do we really + +need to incentivize people to +take this, or could we charge + +them for the medicine. + +Well, if you thought that +everybody benefited from the + +medicine pretty much equally, +whether you took it or not, + +because most of the impact was +on the transmission of the + +disease, then you might need +to subsidize it more. + +You might want to subsidize it +more than if you thought the + +individual got all +the benefit. + +So if you actually want to +measure the spillovers, here's + +one of the things we did in +the paper on deworming. + +So at the time-- + +this is no longer the case, I +want to emphasize-- but at the + +time, there was concern that the +official guidelines were + +not to treat girls over 12 +unless you knew they had + +worms, they shouldn't be treated +presumptively in case + +the medicine caused birth +defects and in case the girls + +were pregnant. + +Turns out, that they've now +given this widely enough that + +WHO guidance is there's no +evidence it causes birth + +defects, and you can give +it to everybody. + +But at the time, they weren't +giving it to girls above 12. + +So imagine you compared girls +above 12 in the treatments + +schools to girls above 12 in +the comparison schools. + +There are some other +things we can do. + +So there are some other sources +of who wasn't treated. + +This comparison I'm going +to show you is a little + +bit more than that. + +But you can compare the treated +students in treatment + +schools to the comparable +students in + +the comparison schools. + +So kids who looked comparable +on a variety of observable + +dimensions or who wound up +taking this when they became + +eligible to take it. + +We saw a very big gap +in prevalence + +among those two groups. + +So this is much more +of a straight + +treatment comparison look. + +Here, we're looking at the +untreated students in the + +treatment schools and trying to +find comparable students in + +the comparison schools. + +I should emphasize this isn't +quite as pure as a standard + +randomized design. + +This program was phased +in over time. + +These are the people that when +their school was phased in, + +they wound up not +getting treated. + +So maybe there were differences +between years, but + +that's a caveat or a footnote. + +So none of these guys were +treated, but these people were + +in a school where their +classmates were treated. + +So they have much lower levels +of infection than these people + +who were also not treated, +but whose + +classmates were not treated. + +Now what if you expect +externalities across-- + +so actually, before I go on to +this further challenge of what + +if there are externalities +across schools, just sticking + +with this question of +externalities within schools, + +talked about one way of dealing +with that was to do + +the randomization at the +level of the school. + +So what's the disadvantage of +doing the randomization at the + +level of the school? + +AUDIENCE: Assuming that +everybody in the same school + +is at the same level. + +MICHAEL KREMER: So you could +still have some differences + +within the school. + +But there is a sense in which +you're going to have less + +information if you're +randomizing at the level of + +the school. + +Yes. + +AUDIENCE: You'd need +more schools. + +MICHAEL KREMER: Yeah, right. + +The crudest way of putting this +is if there's 400 kids in + +a school and you have 100 +schools and you're randomizing + +at the level of the individual, +then you've got + +40,000 observations. + +And if you've got 200 schools +you're randomizing and you're + +randomizing at the level of +the school, you've got 100 + +treatment schools and 100 +comparison schools. + +Much smaller sample size, +much less power. + +That particular calculation I +just did is overstating the + +difference. + +You've learned about clustering + +standard errors before. + +But since there's a +lot of variation-- + +to come back to the way you +were putting it-- since + +there's a lot of random +variation between schools-- + +some schools have good +headmasters, some schools have + +bad headmasters, et cetera-- + +there's a lot of background +noise. + +And it's going to make it harder +to estimate precisely + +the impact of the program. + +So you really have to think +about your particular context. + +When you're thinking about what +level to randomize at, + +think about, in your context, do +you think spillovers are a + +real issue. + +If you think spillovers are a +real issue, then you better + +randomize at a higher level. + +But if you think, in this +particular context, I don't + +need to worry about it, if this +were a cancer drug rather + +than a worm drug, then you +wouldn't need to worry about + +it, and you're much better +off randomizing at + +the individual level. + +There might also be-- yes. + +AUDIENCE: So this might be a +little too [INAUDIBLE], but if + +you're worried about attrition, +would randomizing + +at a higher level make that +less of an issue as well + +because now you're looking +at a higher [INAUDIBLE]? + +So if you lose individuals +within that, + +it's still an issue. + +MICHAEL KREMER: It would +still be an issue. + +Yeah, it's still an issue. + +So let's say that we've decided + +we're going to randomize. + +Take this worm example. + +And we think that most of the +externalities are within + +schools, so we're going to +randomize within schools. + +We know that there might be +some externalities across + +schools because this is an +environment where everybody + +lives on their own +farm basically. + +So you might have two kids +living next to each other, one + +of whom goes to one +school and another + +goes to another school. + +That's not that uncommon. + +So you could have some +externalities across schools. + +But randomizing at the level of +a district would really not + +logistically be very possible. + +You'd have no sample +size left. + +So you know there might be +some externalities across + +schools as well as those +within them. + +But you've already made the +decision to randomize at the + +level of schools. + +So what do you do? + +Well, what you can try and do is +use random variation in the + +density of treatment nearby. + +So if you pick the schools +randomly that were going to be + +treatment schools and the ones +that are going to be + +comparison schools, there will +be some comparison schools + +that happen to be completely +surrounded + +by treatment schools. + +There will be other comparison +schools that don't have any + +treatment schools nearby. + +So you can use that to try +to pick up how big the + +externality is. + +So that's what we tried +to do in this paper. + +So here's a map. + +So the ones are group +one schools. + +They've been treated. + +The twos are group two +schools, treated + +in the second way. + +Threes are group three +schools, now treated + +to the third way. + +Here's a school that's in the +middle of the lake which I + +think is actually +on an island. + +These schools in Uganda are +not really in Uganda. + +GPS used to be intentionally +degraded because people were + +wanting to use it for military-- +it was developed by + +the military, I guess-- + +they didn't want foreign +militaries to have it. + +There are measured +with some error. + +So we've got these schools. + +So we can see there are some +schools that are near + +treatment schools. + +Other schools aren't near +treatment schools. + +By the way, the treatment +schools in this example I just + +did here, the ones shared +with the twos. + +But you could imagine the ones +might share with other ones. + +So there could be externalities +on other + +treatment schools. + +Here's a group three school +that's all by itself and + +doesn't have any neighbors +who were treated. + +Here is a group three school +that has three group one + +schools that are treated. + +So would you want to compare +those to estimate what the + +effect of the deworming +program is? + +AUDIENCE: Wouldn't you use it to +estimate the impact of the + +spillovers? + +MICHAEL KREMER: Yeah, suppose +you were interested in + +estimating the impact of the +spillovers, the medical + +spillovers of treatment. + +Could you compare those +two schools? + +What might make that comparison +invalid if you're + +trying to estimate the +impact of spillovers? + +AUDIENCE: [INAUDIBLE]. + +MICHAEL KREMER: I'm sorry. + +One means a treatment school. + +Three means a comparison +school. + +AUDIENCE: [INAUDIBLE]. + +MICHAEL KREMER: So +one's more rural. + +Exactly. + +This one is obviously in +a less densely settled + +population. + +This one, turns out these are +all rural, but this is + +obviously much more +densely settled. + +That's why they've got all these +schools around there. + +So now in this particular +setting, why + +might that be a problem? + +Yeah. + +AUDIENCE: Because that area +might be internally different + +from the [INAUDIBLE]. + +MICHAEL KREMER: Yeah. + +So this is a disease. + +I probably should +have said more + +about this in the beginning. + +So these worms affect one out of +every three or four people + +in the world. + +And they're spread through +fecal-oral routes. + +They're spread through +fecal matter. + +What are the odds that you're +going to get contaminated with + +fecal matter? + +It depends how many other people +are depositing fecal + +matter in the environment. + +Clearly, over here, there's a +lot of people nearby you who + +might be depositing fecal matter +in the environment. + +Over here, there +aren't so many. + +So you might think that that's +how densely settled the + +population is. + +We don't think of Alaska or +the middle of the desert + +somewhere being very diseased +environments. + +But you think of a highly +concentrated place having a + +lot more disease. + +There's reasons to think that +sparsely settled places will + +have different prevalence of +the disease than heavily + +settled places. + +So what we did because of that, +we didn't want to just + +look at the number of treatment +school nearby. + +We just talked about why that +would be a problem. + +But we want to do that +controlling for the total + +number of schools nearby. + +So we control for the total +density in the area, total + +number of schools within a +certain distance or pupils + +within a certain distance, and +see what's the effect of those + +schools being treatment schools +as opposed to being + +comparison schools. + +Oops, did I skip a-- + +OK. + +So controlling for density, +what we find is that the + +infection rates are 26 +percentage points lower per + +1,000 pupils in treatment +schools within 3 kilometers. + +And then if you go further out, +there are 14 percentage + +points per treatment schools +that are 3 to + +6 kilometers away. + +So this is controlling for the +overall density in the area. + +So hopefully, we're abstracting +from that + +particular problem. + +So now suppose we want to +estimate the overall effects. + +So let me come back +to this problem. + +Clearly, we've incorrectly +estimated. + +We estimated that only $250 +of benefit went through. + +But we think that the true +effect should include the + +effect on the comparison. + +In this previous case, we were +able to estimate the increase + +in school participation in the +treatment group and then also + +in the comparison group through +this technique that I + +just outlined. + +So we know in the comparison +schools, there's a 1.5 + +percentage point increase +in school participation. + +There are three pupils in +control schools for every + +treated child. + +And in the treatment schools, +there was a 7 percentage point + +increase in school participation +for all + +children, but you only needed to +treat 2/3 of the children. + +So you can then calculate what +the overall effect is of + +treating one child. + +So if you treat one child, you +pick up three children in + +comparison schools, each of whom +gets a benefit of 0.015 + +additional years of education. + +Then you pick up this is the +effect on children in the same + +school, and you get an +overall effect of + +0.15 years of education. + +So treating a child costs +about $0.50-- + +in fact, it's probably cheaper +than that when done at scale-- + +but the impact that you're going +to get is if each child, + +you get an extra 0.15 years of +education, if you treat seven + +children, you'll get about an +extra year of education. + +7 times $0.50 is $3.50. + +You spend $3.50 on deworming, +and you get an + +extra year of education. + +Let me pause again here, and +I'll go on and discuss some + +issues on partial compliance +and sample selection bias. + +I'll get partway through that +topic, and then Shawn's going + +to take up where I leave off. + +But are there any questions on +externalities before I go on? + +OK. + +So you might think if you +randomize where the treatment + +is, you're going to get rid +of sample selection bias. + +That's not necessarily +the case. + +So let me show an example. + +So where you randomize where +you want the program to be, + +that's not necessarily the +sole determinant of which + +places actually get treated. + +So let me talk about why. + +So one example would be people +who are assigned to the + +comparison group might try to +move into the treatment group. + +I don't think this happened, but +parents could try and move + +their children from the +comparison school to the + +treatment school. + +It's at least hypothetically +possible. + +What are other possible reasons +why you might not get + +this match between the initial +assignment and where people + +wound up, where the people +wound up treated? + +Yeah. + +AUDIENCE: So you might get +somebody treated, and they + +don't want to take +the medication. + +MICHAEL KREMER: Sure, exactly. + +In the case of deworming, there +were some people who + +either didn't want to take the +medication or who maybe they + +wanted to, but they weren't +able to get the permission + +slip to do it. + +So that's one great example. + +What are other possible +examples? + +If you think about +your concrete + +experience, imagine that-- + +I'll tell you a story +from our experience. + +When this NGO was trying to +get started and they were + +trying to pick the seven schools +where they were going + +to work, they picked the +schools, and they had to go to + +the government for permission +to start working. + +And permission was slow. + +It kept being slow and slow. + +And they didn't realize +what was going on. + +And it turned out, eventually, +that there was a politician + +who was upset. + +The NGO didn't understand why +the politician was upset. + +Because one of the schools was +in his constituency, where + +they were going to +start working. + +Well, it turned out it was in +the part of his constituency + +that voted for his opponent. + +So in that sort of a situation, +what the-- + +I don't remember exactly the +timing of this, but what the + +eventual resolution of this was +they started working in + +the other part of his +constituency, where his + +supporters lived as well. + +So they're all sorts of cases +where you're going to want to + +randomize, but you may +not be able to + +have that happen perfectly. + +In this case, it wasn't a, +quote, "legitimate" reason. + +But there are other cases +where there'd be very + +legitimate reasons why. + +Maybe the need is very intense +in some area, and so the NGO + +or the organization feels +it's very important to + +work in that area. + +So there may be lots of reasons +why some people in the + +comparison group wind +up getting treated. + +So there are cases like we +just heard about where + +individuals allocated +to treatment + +might not get treatment. + +And there are cases where +people who are in the + +comparison group +do get treated. + +So in the case of deworming, +78% of those assigned to + +receive treatment got +some treatment. + +And the main reason they weren't +treated is they just + +happened to be absent from +school the day that the + +treatment was given. + +Some students in the comparison +group were treated + +because they went out and got +the treatment on their own + +through clinics. + +So what do you do? + +Suppose this has already +happened. + +So imagine you have data on +everybody, so attrition isn't + +the problem, but +just the actual + +assignment to treatment. + +The assignment to treatment +and actual treatment don't + +correspond. + +So first, what's the problem +if you just do a straight + +comparison, and what might +you do about it? + +AUDIENCE: In this +[UNINTELLIGIBLE], say they + +[UNINTELLIGIBLE] the students +who were absent just by + +[UNINTELLIGIBLE] to their homes +and [UNINTELLIGIBLE]? + +MICHAEL KREMER: No, so the +program didn't do that. + +So we talked about in the case +of the evaluation, when you're + +trying to measure the test +scores or the impact on + +attendance, you could-- well, +impact on attendance, + +obviously, you find out whether +they're there or not + +by visiting the school. + +Unless you wanted to +do test scores, you + +could track them home. + +But the way the program was +implemented, those kids who + +weren't at school that day +when they gave out the + +deworming pills, they just +didn't get treated. + +Maybe the program shouldn't have +been run that way, but + +that's how it was run. + +And there are reasons +why maybe it + +should be run that way. + +AUDIENCE: In the end, you +wouldn't be considering the + +effect of actually +treating people? + +You'd be comparing the effect of +intending to treat people. + +MICHAEL KREMER: This is exactly +where we're going to + +go, and it's where I'm going to +wind up and where Shawn's + +going to be taking over. + +Imagine you are interested in +the impact of this program on + +test scores. + +So one thing you might think +would be the right thing to do + +would be to just look at the +people who actually were + +treated and compare +them to people who + +actually weren't treated. + +That's going to be problematic +for reasons that + +we'll explain later. + +But let me follow up on your +suggestion which is if you're + +a policy maker, there are +questions beyond this you'd be + +interested in. + +But you raised the idea of +saying, well, what's the + +impact of the intent +to treat somebody. + +And that is going +to be the right + +answer to some questions. + +So let me start with that +question, the relatively + +easier question. + +I'll let Shawn handle the +harder questions. + +Suppose you're a policy maker, +and you're saying, look, + +what's the impact of +putting in this + +school-based deworming program? + +Well, if you're interested +in what's the impact of a + +school-based deworming program, +well, you know in + +reality, it's a true thing that +you want to get at that + +some people are not +going to get it. + +If this is a school-based +program and you hand out the + +pills at the school, tracking +kids to their houses who are + +absent that day, that's +expensive. + +That's hard to implement. + +It uses too much +teachers' time. + +You're probably not +going to find that + +many of the kids anyway. + +So you wouldn't actually +implement it that way. + +If you're a scientist, +you do care. + +But if you're the policy maker, +you might say, no, the + +true effect of this program is +that I'm only going to be able + +to get 78% of the pupils because +22% of the pupils + +aren't there. + +And if some kids don't +want worms-- + +don't want the medicine-- sorry, +if they don't want-- + +or maybe they do want the worms, +or they don't want the + +worms, but they don't want +the medicine either. + +Anyway, if some kids aren't +going to take it, then those + +kids aren't going to take it. + +So you might think, well, I want +to measure the impact of + +this program in realistic +conditions. + +And realistic conditions are +that not everybody's going to + +be able to get it. + +So let's suppose that you're +a policy maker. + +Then what you could do is you +could look at what's called + +the intention to treat estimate, +which is what's the + +effect of the school having the +program or being assigned + +to the program. + +This comes up in medical +trials a lot with, say, + +chemotherapy. + +So some people who start +chemotherapy don't finish it + +because it's just too +painful for them. + +Or they're not able to +handle it medically. + +Again, do want to measure the +impact of chemotherapy on + +those people who managed to +get all the way through? + +Well, not necessarily. + +Maybe what you're interested +in is what's the effect of + +being in this group +that tries it. + +Yes. + +AUDIENCE: Do you think it +actually happened in 1997? + +MICHAEL KREMER: So yeah, +I guess that actually + +helps on the dates. + +AUDIENCE: So it actually +is 10 years on the-- + +MICHAEL KREMER: That's right. + +So it's 10 years. + +It's 10 years before this was +rolled out nationally. + +So yes, some things happened +before that, but this is a + +long delay. + +Yeah, so that first delay +of publication + +took quite a while. + +And then there was a second +delay after it. + +Unfortunately, there's often a +long delay in these things. + +Let me see where we are. + +So what you can do is you use +the original assignment, and + +then you're winding up with +what's called an intention to + +treat estimate. + +So what intention to treat +measures is what happened to + +the average child who was in +a treated school in the + +population. + +So it's not saying, what +happens to the kids who + +actually got the medicine. + +It's saying, what happened to +the average child who is in a + +treated school. + +So that's the correct +interpretation of that. + +Now is that the right +number to look for? + +I talked about some purposes +where that might be the right + +number to look for. + +What would be some reasons why +you might be interested in + +other questions other than the +answer to that question of + +what happened to the average +child in a treated school? + +AUDIENCE: You were thinking of +having a mandatory deworming + +program in Kenya. + +And then you want to know what +would be the impact if + +everybody was forced to treat. + +MICHAEL KREMER: Exactly. + +So in this particular case, this +was a program where it + +was designed in such +a way that not + +everybody had to be treated. + +It wasn't that you can't come to +school unless you show your + +certificate showing you've +been treated. + +But you might well be interested +in, well, what if + +we went a step further. + +And we said, we're going to keep +a supply of medicine at + +the school, and if you are gone +that particular day, then + +you get it the next day. + +And we don't let you come +back to school unless + +you take the medicine. + +Well, you wouldn't +be measuring the + +impact of that program. + +Intention to treat is very good +if you're interested in + +the narrow question of +what's the impact + +of this exact program. + +But if you're trying to go +beyond what's the impact of + +this exact program, you're +trying to start to think about + +generalization, then maybe you +want to understand some of the + +underlying parameters. + +And in this case, the underlying +parameter is what's + +the effect on school attendance +of a kid who had + +worms or a particular level of +worms no longer having that. + +And then it's using that +underlying parameter that you + +might be able to generalize what +would be the effect of + +everybody getting treated, what +would be the effect of + +only some people getting +treated. + +So to do that, Shawn's going to +talk a little bit about how + +you would do that. + +Let's do this example, where +we're trying to get the-- + +I'm wondering whether to skip +this example or not. + +I'll do it. + +I'll go through it. + +In this example, if you look +at the people who were-- + +here's the intent, whether +there was an intention to + +treat them. + +So all school one, you tried to +treat everybody, but only + +some of them got treated. + +In school two, the intent +was not to treat that. + +They were assigned to the +comparison group. + +But a few people got +treated anyway. + +And this is the change in weight +for each individual. + +So then if we average the change +in weight, the average + +change in school one-- + +I don't know if people want to +figure that out for a second-- + +AUDIENCE: [INAUDIBLE]? + +MICHAEL KREMER: Sorry? + +AUDIENCE: [INAUDIBLE]? + +MICHAEL KREMER: So +it's 1.3, right? + +And the average change +in school two is 0.9. + +So the intention to treat effect +would be comparing the + +1.3 to the 0.9. + +Now when is that useful? + +Well, that's what I'm saying, +for an actual program. + +But you're not measuring this +medical effect that you'd want + +for generalization. + +Here is an example where it's a +malaria prevention program, + +but there's political +pressures to treat. + +And so you add. + +Again, you can measure this +impact, this intention to + +treat measure. + +Let me-- + +I'm wondering whether +I should-- + +let me go back here and say-- + +Initially, the blue circles +were the ones that were + +supposed to be treated. + +I want to talk about why you +can't do what the apparently + +obvious thing of just comparing +the guys who were + +treated to the ones +who weren't. + +You've got this malaria +prevention program. + +40 villages are sampled. + +20 were assigned to get the +treatment the first year. + +20 were assigned to +be the comparison. + +But some of the comparison +villages object to this, and + +they say, we want to +be treated too. + +And the program manager says, +look, we just have to go ahead + +and treat this. + +So if the program only gets +implemented in 15 villages, as + +well as in 2 villages that +were supposed to be + +comparison, so what do +you do to measure the + +impact of the program? + +So by the way, in the previous +case I mentioned with the + +politician in Kenya, the extra +school was neither treatment + +or comparison, so really, in +that case, there was no + +problem because it was just +out of the sample frame + +altogether, the extra school +that got treated. + +In this case, some of the +comparison schools wind up + +getting treated. + +So how do you measure it? + +Well, here's the problem with +what would happen if you just + +did the naive thing and said, +we're going to compare all the + +guys who actually got treated +to the comparison schools. + +So we've got the blue schools +are the ones that were + +supposed to be treated that +are in the sample. + +The white schools are +other villages. + +So T is the original +treatment group. + +The T's are supposed +to be treated. + +The blues without T's in them +are supposed to be the + +comparison. + +Now the actual treatment +are the green circles. + +So you can't compare the +green circle villages + +with the blue dots. + +The green circles are the ones +that were actually treated. + +And the blue dots are +the comparison. + +Why can't you make +that comparison? + +AUDIENCE: They're not +randomly assigned + +from the very beginning. + +MICHAEL KREMER: They're not +randomly assigned from the + +very beginning. + +And can you be more specific +about what your hypothesis + +might be on the difference? + +AUDIENCE: [UNINTELLIGIBLE] +that fought to get the + +treatment would prefer some +help from the schools or + +villages that were initially +selected randomly. + +MICHAEL KREMER: Exactly, +exactly. + +The guys who fought to get the +treatment might differ from + +the ones that are initially +selected randomly. + +They might have particularly +capable leaders, for example, + +or influential leaders. + +And those influential leaders-- +this politician who + +managed to get the NGO program +assigned to his area, he might + +have fought to get lots of other +programs assigned there. + +So we don't know whether we're +measuring the impact of this + +program, or we're measuring +the fact that they're just + +able to use their political +influence to get everything + +assigned there. + +And similarly, if you +leave out the-- + +So this is basically +just making the + +point that you said. + +The other thing that you could +think about doing is comparing + +the villages that were assigned +to be a treatment + +group and actually got treated +with the ones that were + +supposed to be a comparison +group. + +So what's the problem +with that? + +AUDIENCE: Attrition. + +It's kind of like attrition. + +MICHAEL KREMER: Exactly, it's +the same principle, which is + +you'd be leaving out a group +that is the ones who were + +assigned to be treated, +but didn't + +wind up getting treated. + +Well, the ones who were assigned +to be treated and, + +nonetheless, didn't get treated, +those might be the + +ones-- so for example, imagine +there's violence in some of + +these areas. + +And your field workers can't go +there, so they never wound + +up getting treated. + +Well, the violence itself might +have had an impact on + +development outcomes. + +So you may be measuring the +impact of the violence or of + +particularly bad leaders who, +despite being in the treatment + +group, still can't get their +village treated. + +So that's not going to be a +valid comparison either. + +So one thing you can do is the +intention to treat estimator. + +You can do that again +in this case. + +So compare the initial 20 +treatment villages with the + +initial 20 comparison +villages. + +And then you've got +the ITT estimator. + +Now before I argued that the ITT +estimator, in the case of + +the deworming program, that +arguably might be a very good + +measure of some things. + +You might not be able to do some +other things with it, but + +it was still a useful measure. + +But in this case, suppose we +want to actually understand + +what the impact of the malaria +treatment program. + +And we know that what's the +impact of it if you're able to + +implement it. + +Well, the intention to +treat estimator isn't + +really telling you that. + +It's telling you what's the +effect of being assigned to + +the treatment. + +But it's not saying what's the +effect of the program in the + +cases where you're able +to implement it. + +So that's a problem. + +And that's where I'm going to +leave you with that problem. + +And then Shawn's going to +tell you, at least, + +a solution to it. \ No newline at end of file diff --git a/FcNUJpbvTy8.txt b/FcNUJpbvTy8.txt new file mode 100644 index 0000000000000000000000000000000000000000..1f8bd4bb5fcfb8c80da29196bcf8fae03bad9cfb --- /dev/null +++ b/FcNUJpbvTy8.txt @@ -0,0 +1,11373 @@ +align:start position:0% + +all right we're beginning the uh lecture + + align:start position:0% +all right we're beginning the uh lecture + + + align:start position:0% +all right we're beginning the uh lecture +on handout number 15 this is um the + + align:start position:0% +on handout number 15 this is um the + + + align:start position:0% +on handout number 15 this is um the +second lecture on uh dopent diffusion + + align:start position:0% +second lecture on uh dopent diffusion + + + align:start position:0% +second lecture on uh dopent diffusion +and profile measurement and we're uh + + align:start position:0% +and profile measurement and we're uh + + + align:start position:0% +and profile measurement and we're uh +working on chapter seven of your + + align:start position:0% +working on chapter seven of your + + + align:start position:0% +working on chapter seven of your +text so last time we introduced some of + + align:start position:0% +text so last time we introduced some of + + + align:start position:0% +text so last time we introduced some of +the basics of dop and diffusion we + + align:start position:0% +the basics of dop and diffusion we + + + align:start position:0% +the basics of dop and diffusion we +talked about uh basic definition of + + align:start position:0% +talked about uh basic definition of + + + align:start position:0% +talked about uh basic definition of +sheet resistance and the scaling + + align:start position:0% +sheet resistance and the scaling + + + align:start position:0% +sheet resistance and the scaling +requires PR L and we pointed out there's + + align:start position:0% +requires PR L and we pointed out there's + + + align:start position:0% +requires PR L and we pointed out there's +a conflict between the need for smaller + + align:start position:0% +a conflict between the need for smaller + + + align:start position:0% +a conflict between the need for smaller +serious resistance and the need to + + align:start position:0% +serious resistance and the need to + + + align:start position:0% +serious resistance and the need to +decrease function depths to improve + + align:start position:0% +decrease function depths to improve + + + align:start position:0% +decrease function depths to improve +control on the channel charge we also + + align:start position:0% +control on the channel charge we also + + + align:start position:0% +control on the channel charge we also +talked about short Channel effects and + + align:start position:0% +talked about short Channel effects and + + + align:start position:0% +talked about short Channel effects and +how BT decreases as L uh goes + + align:start position:0% +how BT decreases as L uh goes + + + align:start position:0% +how BT decreases as L uh goes +down we mentioned the use of + + align:start position:0% +down we mentioned the use of + + + align:start position:0% +down we mentioned the use of +predeposition uh either in the gas phase + + align:start position:0% +predeposition uh either in the gas phase + + + align:start position:0% +predeposition uh either in the gas phase +or byon implantation and then the use of + + align:start position:0% +or byon implantation and then the use of + + + align:start position:0% +or byon implantation and then the use of +subsequent Drive-In of dopents to create + + align:start position:0% +subsequent Drive-In of dopents to create + + + align:start position:0% +subsequent Drive-In of dopents to create +doped + + align:start position:0% +doped + + + align:start position:0% +doped +regions we spoke about macroscopic + + align:start position:0% +regions we spoke about macroscopic + + + align:start position:0% +regions we spoke about macroscopic +diffusion from the point of fixed first + + align:start position:0% +diffusion from the point of fixed first + + + align:start position:0% +diffusion from the point of fixed first +and second laws and gave a few cases + + align:start position:0% +and second laws and gave a few cases + + + align:start position:0% +and second laws and gave a few cases +there were only about three or four + + align:start position:0% +there were only about three or four + + + align:start position:0% +there were only about three or four +cases where there are simp analytic + + align:start position:0% +cases where there are simp analytic + + + align:start position:0% +cases where there are simp analytic +solutions to the diffusion + + align:start position:0% +solutions to the diffusion + + + align:start position:0% +solutions to the diffusion +equation today I want to just briefly + + align:start position:0% +equation today I want to just briefly + + + align:start position:0% +equation today I want to just briefly +review those analytic solution + + align:start position:0% +review those analytic solution + + + align:start position:0% +review those analytic solution +examples and then um talk about uh a + + align:start position:0% +examples and then um talk about uh a + + + align:start position:0% +examples and then um talk about uh a +brief introduction to numerical + + align:start position:0% +brief introduction to numerical + + + align:start position:0% +brief introduction to numerical +solutions to diffusion + + align:start position:0% +solutions to diffusion + + + align:start position:0% +solutions to diffusion +equation then we'll talk about uh design + + align:start position:0% +equation then we'll talk about uh design + + + align:start position:0% +equation then we'll talk about uh design +of diffused layers based upon certain + + align:start position:0% +of diffused layers based upon certain + + + align:start position:0% +of diffused layers based upon certain +device requirements such as the sheet + + align:start position:0% +device requirements such as the sheet + + + align:start position:0% +device requirements such as the sheet +resistance and uh our first deviation + + align:start position:0% +resistance and uh our first deviation + + + align:start position:0% +resistance and uh our first deviation +from fii and diffusion we'll we'll + + align:start position:0% +from fii and diffusion we'll we'll + + + align:start position:0% +from fii and diffusion we'll we'll +discuss electric field effects on dop + + align:start position:0% +discuss electric field effects on dop + + + align:start position:0% +discuss electric field effects on dop +and diffusion + + align:start position:0% +and diffusion + + + align:start position:0% +and diffusion +so let's go on on to slide number two + + align:start position:0% +so let's go on on to slide number two + + + align:start position:0% +so let's go on on to slide number two +and just review from last time uh this + + align:start position:0% +and just review from last time uh this + + + align:start position:0% +and just review from last time uh this +pictorial um view of fixed Second Law + + align:start position:0% +pictorial um view of fixed Second Law + + + align:start position:0% +pictorial um view of fixed Second Law +what I'm showing here is a volume + + align:start position:0% +what I'm showing here is a volume + + + align:start position:0% +what I'm showing here is a volume +element um that is uh shown by the blue + + align:start position:0% +element um that is uh shown by the blue + + + align:start position:0% +element um that is uh shown by the blue +sort of rectangular uh element and there + + align:start position:0% +sort of rectangular uh element and there + + + align:start position:0% +sort of rectangular uh element and there +is a flux F Sub in going in the left + + align:start position:0% +is a flux F Sub in going in the left + + + align:start position:0% +is a flux F Sub in going in the left +hand face and a flux F sub out uh going + + align:start position:0% +hand face and a flux F sub out uh going + + + align:start position:0% +hand face and a flux F sub out uh going +out in the right hand face remember + + align:start position:0% +out in the right hand face remember + + + align:start position:0% +out in the right hand face remember +again our basic definition of flux is + + align:start position:0% +again our basic definition of flux is + + + align:start position:0% +again our basic definition of flux is +it's a number of atoms or particles per + + align:start position:0% +it's a number of atoms or particles per + + + align:start position:0% +it's a number of atoms or particles per +unit time per unit area so looking at + + align:start position:0% +unit time per unit area so looking at + + + align:start position:0% +unit time per unit area so looking at +this uh in this Cube we can uh calculate + + align:start position:0% +this uh in this Cube we can uh calculate + + + align:start position:0% +this uh in this Cube we can uh calculate +the net flow of atoms into this volume + + align:start position:0% +the net flow of atoms into this volume + + + align:start position:0% +the net flow of atoms into this volume +uh into that small volume as shown in + + align:start position:0% +uh into that small volume as shown in + + + align:start position:0% +uh into that small volume as shown in +the upper left uh corner is equal to the + + align:start position:0% +the upper left uh corner is equal to the + + + align:start position:0% +the upper left uh corner is equal to the +area a of one of those faces times the + + align:start position:0% +area a of one of those faces times the + + + align:start position:0% +area a of one of those faces times the +difference between F out minus + + align:start position:0% +difference between F out minus + + + align:start position:0% +difference between F out minus +FN so that's the net flow of atoms and + + align:start position:0% +FN so that's the net flow of atoms and + + + align:start position:0% +FN so that's the net flow of atoms and +we can write that as a times and just + + align:start position:0% +we can write that as a times and just + + + align:start position:0% +we can write that as a times and just +looking at uh sort of the geometry it's + + align:start position:0% +looking at uh sort of the geometry it's + + + align:start position:0% +looking at uh sort of the geometry it's +Delta x times the the uh change in + + align:start position:0% +Delta x times the the uh change in + + + align:start position:0% +Delta x times the the uh change in +concentration Delta C divided Delta time + + align:start position:0% +concentration Delta C divided Delta time + + + align:start position:0% +concentration Delta C divided Delta time +uh delta T so we're can just rearrange + + align:start position:0% +uh delta T so we're can just rearrange + + + align:start position:0% +uh delta T so we're can just rearrange +just a little bit the A's go out and + + align:start position:0% +just a little bit the A's go out and + + + align:start position:0% +just a little bit the A's go out and +what we see is that the first derivative + + align:start position:0% +what we see is that the first derivative + + + align:start position:0% +what we see is that the first derivative +of the flux Delta F over Delta X is + + align:start position:0% +of the flux Delta F over Delta X is + + + align:start position:0% +of the flux Delta F over Delta X is +equal to the time change Delta C over + + align:start position:0% +equal to the time change Delta C over + + + align:start position:0% +equal to the time change Delta C over +delta T um so mathematically if we want + + align:start position:0% +delta T um so mathematically if we want + + + align:start position:0% +delta T um so mathematically if we want +to write this uh not in terms of Deltas + + align:start position:0% +to write this uh not in terms of Deltas + + + align:start position:0% +to write this uh not in terms of Deltas +or differences but in terms of um + + align:start position:0% +or differences but in terms of um + + + align:start position:0% +or differences but in terms of um +differentials what we see is a Time rate + + align:start position:0% +differentials what we see is a Time rate + + + align:start position:0% +differentials what we see is a Time rate +of change of the of the concentration in + + align:start position:0% +of change of the of the concentration in + + + align:start position:0% +of change of the of the concentration in +the Box partial C partial T is equal to + + align:start position:0% +the Box partial C partial T is equal to + + + align:start position:0% +the Box partial C partial T is equal to +the first derivative of the flux partial + + align:start position:0% +the first derivative of the flux partial + + + align:start position:0% +the first derivative of the flux partial +partial + + align:start position:0% +partial + + + align:start position:0% +partial +X and then we can substitute in the + + align:start position:0% +X and then we can substitute in the + + + align:start position:0% +X and then we can substitute in the +equation on the center of the page for + + align:start position:0% +equation on the center of the page for + + + align:start position:0% +equation on the center of the page for +the flux we know from fixed first law + + align:start position:0% +the flux we know from fixed first law + + + align:start position:0% +the flux we know from fixed first law +that f is equal to D partial C partial X + + align:start position:0% +that f is equal to D partial C partial X + + + align:start position:0% +that f is equal to D partial C partial X +so that is indeed um a way of deriving + + align:start position:0% +so that is indeed um a way of deriving + + + align:start position:0% +so that is indeed um a way of deriving +uh just sort of bookkeep of deriving + + align:start position:0% +uh just sort of bookkeep of deriving + + + align:start position:0% +uh just sort of bookkeep of deriving +fixed Second + + align:start position:0% +fixed Second + + + align:start position:0% +fixed Second +Law now uh the equation in the center of + + align:start position:0% +Law now uh the equation in the center of + + + align:start position:0% +Law now uh the equation in the center of +the page can be simplified somewhat if + + align:start position:0% +the page can be simplified somewhat if + + + align:start position:0% +the page can be simplified somewhat if +uh we have a special case where the + + align:start position:0% +uh we have a special case where the + + + align:start position:0% +uh we have a special case where the +diffusivity is a constant where it + + align:start position:0% +diffusivity is a constant where it + + + align:start position:0% +diffusivity is a constant where it +doesn't vary in space I can pull the D + + align:start position:0% +doesn't vary in space I can pull the D + + + align:start position:0% +doesn't vary in space I can pull the D +out of the partial deriva with respect + + align:start position:0% +out of the partial deriva with respect + + + align:start position:0% +out of the partial deriva with respect +to X and we just get um partial C + + align:start position:0% +to X and we just get um partial C + + + align:start position:0% +to X and we just get um partial C +partial T so the time rate of change uh + + align:start position:0% +partial T so the time rate of change uh + + + align:start position:0% +partial T so the time rate of change uh +of the concentration is equal to a + + align:start position:0% +of the concentration is equal to a + + + align:start position:0% +of the concentration is equal to a +constant diffusivity it's a number times + + align:start position:0% +constant diffusivity it's a number times + + + align:start position:0% +constant diffusivity it's a number times +the second derivative of the + + align:start position:0% +the second derivative of the + + + align:start position:0% +the second derivative of the +concentration with respect to X so that + + align:start position:0% +concentration with respect to X so that + + + align:start position:0% +concentration with respect to X so that +is uh at the bottom of the page would be + + align:start position:0% +is uh at the bottom of the page would be + + + align:start position:0% +is uh at the bottom of the page would be +then the special case of fixed second + + align:start position:0% +then the special case of fixed second + + + align:start position:0% +then the special case of fixed second +law when the diffusivity is a + + align:start position:0% +law when the diffusivity is a + + + align:start position:0% +law when the diffusivity is a +constant so let's go on to slide number + + align:start position:0% +constant so let's go on to slide number + + + align:start position:0% +constant so let's go on to slide number +three uh and these are um a couple of + + align:start position:0% +three uh and these are um a couple of + + + align:start position:0% +three uh and these are um a couple of +cases we solved last time where we we + + align:start position:0% +cases we solved last time where we we + + + align:start position:0% +cases we solved last time where we we +wrote down the solutions last time for + + align:start position:0% +wrote down the solutions last time for + + + align:start position:0% +wrote down the solutions last time for +two cases which are commonly encountered + + align:start position:0% +two cases which are commonly encountered + + + align:start position:0% +two cases which are commonly encountered +and which for which analytic Solutions + + align:start position:0% +and which for which analytic Solutions + + + align:start position:0% +and which for which analytic Solutions +are available on the left hand side and + + align:start position:0% +are available on the left hand side and + + + align:start position:0% +are available on the left hand side and +reviewing the case of a predeposition + + align:start position:0% +reviewing the case of a predeposition + + + align:start position:0% +reviewing the case of a predeposition +and again by sort of by definition in + + align:start position:0% +and again by sort of by definition in + + + align:start position:0% +and again by sort of by definition in +this case we are assuming that there is + + align:start position:0% +this case we are assuming that there is + + + align:start position:0% +this case we are assuming that there is +a supply of do of of dopent or atoms + + align:start position:0% +a supply of do of of dopent or atoms + + + align:start position:0% +a supply of do of of dopent or atoms +that are diffusing that holds the + + align:start position:0% +that are diffusing that holds the + + + align:start position:0% +that are diffusing that holds the +surface concentration at a constant + + align:start position:0% +surface concentration at a constant + + + align:start position:0% +surface concentration at a constant +value C subs and number is fixed and we + + align:start position:0% +value C subs and number is fixed and we + + + align:start position:0% +value C subs and number is fixed and we +said in this case that the shape of the + + align:start position:0% +said in this case that the shape of the + + + align:start position:0% +said in this case that the shape of the +profile c as a function of depth X and + + align:start position:0% +profile c as a function of depth X and + + + align:start position:0% +profile c as a function of depth X and +time is given by this surface + + align:start position:0% +time is given by this surface + + + align:start position:0% +time is given by this surface +concentration C Subs times the + + align:start position:0% +concentration C Subs times the + + + align:start position:0% +concentration C Subs times the +complimentary error function of X over + + align:start position:0% +complimentary error function of X over + + + align:start position:0% +complimentary error function of X over +2un DT so that is the actual analytic + + align:start position:0% +2un DT so that is the actual analytic + + + align:start position:0% +2un DT so that is the actual analytic +solution to fix second law for a + + align:start position:0% +solution to fix second law for a + + + align:start position:0% +solution to fix second law for a +constant + + align:start position:0% +constant + + + align:start position:0% +constant +diffusivity and uh we also know that the + + align:start position:0% +diffusivity and uh we also know that the + + + align:start position:0% +diffusivity and uh we also know that the +integral of that uh that function uh + + align:start position:0% +integral of that uh that function uh + + + align:start position:0% +integral of that uh that function uh +integrated over over space or throughout + + align:start position:0% +integrated over over space or throughout + + + align:start position:0% +integrated over over space or throughout +the the Silicon uh has a value Q that's + + align:start position:0% +the the Silicon uh has a value Q that's + + + align:start position:0% +the the Silicon uh has a value Q that's +the do so the area under the curve and + + align:start position:0% +the do so the area under the curve and + + + align:start position:0% +the do so the area under the curve and +that can be solved for and it turns out + + align:start position:0% +that can be solved for and it turns out + + + align:start position:0% +that can be solved for and it turns out +to be 2 CS overun of Pi * + + align:start position:0% +to be 2 CS overun of Pi * + + + align:start position:0% +to be 2 CS overun of Pi * +DT um so this is a particular case and + + align:start position:0% +DT um so this is a particular case and + + + align:start position:0% +DT um so this is a particular case and +we in fact showing a plot um on the + + align:start position:0% +we in fact showing a plot um on the + + + align:start position:0% +we in fact showing a plot um on the +vertical axis of C over c s as a + + align:start position:0% +vertical axis of C over c s as a + + + align:start position:0% +vertical axis of C over c s as a +function of depth + + align:start position:0% +function of depth + + + align:start position:0% +function of depth +for uh several different uh times there + + align:start position:0% +for uh several different uh times there + + + align:start position:0% +for uh several different uh times there +are three curves here shown where the + + align:start position:0% +are three curves here shown where the + + + align:start position:0% +are three curves here shown where the +square of DT or two times the square of + + align:start position:0% +square of DT or two times the square of + + + align:start position:0% +square of DT or two times the square of +DT is being varied from 0.1 Micron all + + align:start position:0% +DT is being varied from 0.1 Micron all + + + align:start position:0% +DT is being varied from 0.1 Micron all +the way up to one micron you get a feel + + align:start position:0% +the way up to one micron you get a feel + + + align:start position:0% +the way up to one micron you get a feel +for how the shape of the comp + + align:start position:0% +for how the shape of the comp + + + align:start position:0% +for how the shape of the comp +complimentary airor function evolves + + align:start position:0% +complimentary airor function evolves + + + align:start position:0% +complimentary airor function evolves +with + + align:start position:0% +with + + + align:start position:0% +with +time um in contrast on the right hand + + align:start position:0% +time um in contrast on the right hand + + + align:start position:0% +time um in contrast on the right hand +side we're showing the case of a + + align:start position:0% +side we're showing the case of a + + + align:start position:0% +side we're showing the case of a +drive-in that would typically be done + + align:start position:0% +drive-in that would typically be done + + + align:start position:0% +drive-in that would typically be done +after prep and driving takes place uh + + align:start position:0% +after prep and driving takes place uh + + + align:start position:0% +after prep and driving takes place uh +usually under the assumption of a + + align:start position:0% +usually under the assumption of a + + + align:start position:0% +usually under the assumption of a +constant dose Q so the con area under + + align:start position:0% +constant dose Q so the con area under + + + align:start position:0% +constant dose Q so the con area under +the curve and what's happening as a + + align:start position:0% +the curve and what's happening as a + + + align:start position:0% +the curve and what's happening as a +function of time then um is the the + + align:start position:0% +function of time then um is the the + + + align:start position:0% +function of time then um is the the +shape of the curve is changing and it + + align:start position:0% +shape of the curve is changing and it + + + align:start position:0% +shape of the curve is changing and it +it's um we know the solution is a gausin + + align:start position:0% +it's um we know the solution is a gausin + + + align:start position:0% +it's um we know the solution is a gausin +uh the solution to fix Second + + align:start position:0% +uh the solution to fix Second + + + align:start position:0% +uh the solution to fix Second +Law um and in fact if you look at this + + align:start position:0% +Law um and in fact if you look at this + + + align:start position:0% +Law um and in fact if you look at this +equation as a function of time you'll + + align:start position:0% +equation as a function of time you'll + + + align:start position:0% +equation as a function of time you'll +see that the the concentration of the + + align:start position:0% +see that the the concentration of the + + + align:start position:0% +see that the the concentration of the +surface is dropping as a function of + + align:start position:0% +surface is dropping as a function of + + + align:start position:0% +surface is dropping as a function of +time according to 1 over the of + + align:start position:0% +time according to 1 over the of + + + align:start position:0% +time according to 1 over the of +DT and uh the P profile is it's + + align:start position:0% +DT and uh the P profile is it's + + + align:start position:0% +DT and uh the P profile is it's +broadening it's width or standard + + align:start position:0% +broadening it's width or standard + + + align:start position:0% +broadening it's width or standard +deviation is in inreasing according to + + align:start position:0% +deviation is in inreasing according to + + + align:start position:0% +deviation is in inreasing according to +DT and U there are a couple different + + align:start position:0% +DT and U there are a couple different + + + align:start position:0% +DT and U there are a couple different +cases shown on the light um so these + + align:start position:0% +cases shown on the light um so these + + + align:start position:0% +cases shown on the light um so these +Solutions are valid under this + + align:start position:0% +Solutions are valid under this + + + align:start position:0% +Solutions are valid under this +particular case where the concentration + + align:start position:0% +particular case where the concentration + + + align:start position:0% +particular case where the concentration +of a diffusing dopen is less than inabi + + align:start position:0% +of a diffusing dopen is less than inabi + + + align:start position:0% +of a diffusing dopen is less than inabi +and that that implies uh in that case + + align:start position:0% +and that that implies uh in that case + + + align:start position:0% +and that that implies uh in that case +that the diffusivity is a constant it + + align:start position:0% +that the diffusivity is a constant it + + + align:start position:0% +that the diffusivity is a constant it +doesn't vary in space we'll talk in + + align:start position:0% +doesn't vary in space we'll talk in + + + align:start position:0% +doesn't vary in space we'll talk in +subsequent lectures about the case when + + align:start position:0% +subsequent lectures about the case when + + + align:start position:0% +subsequent lectures about the case when +that uh the concentration is quite high + + align:start position:0% +that uh the concentration is quite high + + + align:start position:0% +that uh the concentration is quite high +or higher than + + align:start position:0% +or higher than + + + align:start position:0% +or higher than +nly so let's go on to slide number four + + align:start position:0% +nly so let's go on to slide number four + + + align:start position:0% +nly so let's go on to slide number four +and uh this reviews from last time what + + align:start position:0% +and uh this reviews from last time what + + + align:start position:0% +and uh this reviews from last time what +we showed is an arous plot of the + + align:start position:0% +we showed is an arous plot of the + + + align:start position:0% +we showed is an arous plot of the +intrinsic diffusion coefficients of some + + align:start position:0% +intrinsic diffusion coefficients of some + + + align:start position:0% +intrinsic diffusion coefficients of some +common delins and silicon and what we're + + align:start position:0% +common delins and silicon and what we're + + + align:start position:0% +common delins and silicon and what we're +showing on the left axis uh on a log + + align:start position:0% +showing on the left axis uh on a log + + + align:start position:0% +showing on the left axis uh on a log +scale is a diffusivity in units of C + + align:start position:0% +scale is a diffusivity in units of C + + + align:start position:0% +scale is a diffusivity in units of C +centimet squar per second and the x-axis + + align:start position:0% +centimet squar per second and the x-axis + + + align:start position:0% +centimet squar per second and the x-axis +is uh 1,000 over temperature in + + align:start position:0% +is uh 1,000 over temperature in + + + align:start position:0% +is uh 1,000 over temperature in +Kelvin the lower x-axis the upper x-axis + + align:start position:0% +Kelvin the lower x-axis the upper x-axis + + + align:start position:0% +Kelvin the lower x-axis the upper x-axis +actually has the temperatures uh uh + + align:start position:0% +actually has the temperatures uh uh + + + align:start position:0% +actually has the temperatures uh uh +actually + + align:start position:0% +actually + + + align:start position:0% +actually +indicated so um we are intrinsic + + align:start position:0% +indicated so um we are intrinsic + + + align:start position:0% +indicated so um we are intrinsic +diffusivities so they apply when in the + + align:start position:0% +diffusivities so they apply when in the + + + align:start position:0% +diffusivities so they apply when in the +carrier concent the um concentration of + + align:start position:0% +carrier concent the um concentration of + + + align:start position:0% +carrier concent the um concentration of +the dope and is less than ni uh at the + + align:start position:0% +the dope and is less than ni uh at the + + + align:start position:0% +the dope and is less than ni uh at the +diffusion temperature one thing you can + + align:start position:0% +diffusion temperature one thing you can + + + align:start position:0% +diffusion temperature one thing you can +notice right off the bat is there there + + align:start position:0% +notice right off the bat is there there + + + align:start position:0% +notice right off the bat is there there +are some fast diffusers in Silicon such + + align:start position:0% +are some fast diffusers in Silicon such + + + align:start position:0% +are some fast diffusers in Silicon such +as Bond fos vering Indian they the upper + + align:start position:0% +as Bond fos vering Indian they the upper + + + align:start position:0% +as Bond fos vering Indian they the upper +three curves and the slower diffusers + + align:start position:0% +three curves and the slower diffusers + + + align:start position:0% +three curves and the slower diffusers +are Arsenic and anamor silic uh it turns + + align:start position:0% +are Arsenic and anamor silic uh it turns + + + align:start position:0% +are Arsenic and anamor silic uh it turns +out just for practical reasons because + + align:start position:0% +out just for practical reasons because + + + align:start position:0% +out just for practical reasons because +of their High electrical solubility that + + align:start position:0% +of their High electrical solubility that + + + align:start position:0% +of their High electrical solubility that +Boron is often the um ptype doener + + align:start position:0% +Boron is often the um ptype doener + + + align:start position:0% +Boron is often the um ptype doener +Choice it pretty much is and arsenic uh + + align:start position:0% +Choice it pretty much is and arsenic uh + + + align:start position:0% +Choice it pretty much is and arsenic uh +in N type dopers you can choose arsenic + + align:start position:0% +in N type dopers you can choose arsenic + + + align:start position:0% +in N type dopers you can choose arsenic +or phosis but arsenic is usually chosen + + align:start position:0% +or phosis but arsenic is usually chosen + + + align:start position:0% +or phosis but arsenic is usually chosen +uh because of its higher electrical + + align:start position:0% +uh because of its higher electrical + + + align:start position:0% +uh because of its higher electrical +solubility and uh also sometimes it's + + align:start position:0% +solubility and uh also sometimes it's + + + align:start position:0% +solubility and uh also sometimes it's +lower diffusion coefficient it's easier + + align:start position:0% +lower diffusion coefficient it's easier + + + align:start position:0% +lower diffusion coefficient it's easier +to control + + align:start position:0% +to control + + + align:start position:0% +to control +profiles so what typically we're going + + align:start position:0% +profiles so what typically we're going + + + align:start position:0% +profiles so what typically we're going +to have issues with controlling + + align:start position:0% +to have issues with controlling + + + align:start position:0% +to have issues with controlling +diffusion in the pp regions because Bond + + align:start position:0% +diffusion in the pp regions because Bond + + + align:start position:0% +diffusion in the pp regions because Bond +uh is diffusing at any given temperature + + align:start position:0% +uh is diffusing at any given temperature + + + align:start position:0% +uh is diffusing at any given temperature +almost in order of magnitude uh higher + + align:start position:0% +almost in order of magnitude uh higher + + + align:start position:0% +almost in order of magnitude uh higher +diffusivity than the case of + + align:start position:0% +diffusivity than the case of + + + align:start position:0% +diffusivity than the case of +arsenic all right let's go on to slide + + align:start position:0% +arsenic all right let's go on to slide + + + align:start position:0% +arsenic all right let's go on to slide +number + + align:start position:0% +number + + + align:start position:0% +number +five and um here what we are trying to + + align:start position:0% +five and um here what we are trying to + + + align:start position:0% +five and um here what we are trying to +talk about is uh the effect of + + align:start position:0% +talk about is uh the effect of + + + align:start position:0% +talk about is uh the effect of +successive diffusions in say a moss + + align:start position:0% +successive diffusions in say a moss + + + align:start position:0% +successive diffusions in say a moss +process flow um uh on the on the doping + + align:start position:0% +process flow um uh on the on the doping + + + align:start position:0% +process flow um uh on the on the doping +profiles you remember from the first + + align:start position:0% +profiles you remember from the first + + + align:start position:0% +profiles you remember from the first +lecture of this course we talked uh we + + align:start position:0% +lecture of this course we talked uh we + + + align:start position:0% +lecture of this course we talked uh we +kind of walked through uh an example of + + align:start position:0% +kind of walked through uh an example of + + + align:start position:0% +kind of walked through uh an example of +NR circuit bation process and you know + + align:start position:0% +NR circuit bation process and you know + + + align:start position:0% +NR circuit bation process and you know +that they involve a large number of + + align:start position:0% +that they involve a large number of + + + align:start position:0% +that they involve a large number of +different steps at various temperatures + + align:start position:0% +different steps at various temperatures + + + align:start position:0% +different steps at various temperatures +we don't just simply do a pre-ip and + + align:start position:0% +we don't just simply do a pre-ip and + + + align:start position:0% +we don't just simply do a pre-ip and +then a drive-in and then it's done that + + align:start position:0% +then a drive-in and then it's done that + + + align:start position:0% +then a drive-in and then it's done that +could be oxidations it could be uh other + + align:start position:0% +could be oxidations it could be uh other + + + align:start position:0% +could be oxidations it could be uh other +uh high temperature steps in which uh + + align:start position:0% +uh high temperature steps in which uh + + + align:start position:0% +uh high temperature steps in which uh +the doens are going to move so if you + + align:start position:0% +the doens are going to move so if you + + + align:start position:0% +the doens are going to move so if you +have a whole series of steps what's the + + align:start position:0% +have a whole series of steps what's the + + + align:start position:0% +have a whole series of steps what's the +question is what is the uh actual final + + align:start position:0% +question is what is the uh actual final + + + align:start position:0% +question is what is the uh actual final +profile and how can we approximated well + + align:start position:0% +profile and how can we approximated well + + + align:start position:0% +profile and how can we approximated well +it turns out in the case of gine + + align:start position:0% +it turns out in the case of gine + + + align:start position:0% +it turns out in the case of gine +diffusion that uh we can write the total + + align:start position:0% +diffusion that uh we can write the total + + + align:start position:0% +diffusion that uh we can write the total +effective D2 + + align:start position:0% +effective D2 + + + align:start position:0% +effective D2 +product uh as being a measure of a + + align:start position:0% +product uh as being a measure of a + + + align:start position:0% +product uh as being a measure of a +thermal budget that's used in that + + align:start position:0% +thermal budget that's used in that + + + align:start position:0% +thermal budget that's used in that +process and for ging diffusion we can + + align:start position:0% +process and for ging diffusion we can + + + align:start position:0% +process and for ging diffusion we can +actually sum up the products of the + + align:start position:0% +actually sum up the products of the + + + align:start position:0% +actually sum up the products of the +diffusivity in any given time step times + + align:start position:0% +diffusivity in any given time step times + + + align:start position:0% +diffusivity in any given time step times +the length of that time step D * T we + + align:start position:0% +the length of that time step D * T we + + + align:start position:0% +the length of that time step D * T we +can sum up those DT products add them up + + align:start position:0% +can sum up those DT products add them up + + + align:start position:0% +can sum up those DT products add them up +and uh end up with an effective DT for + + align:start position:0% +and uh end up with an effective DT for + + + align:start position:0% +and uh end up with an effective DT for +the entire process again assuming that + + align:start position:0% +the entire process again assuming that + + + align:start position:0% +the entire process again assuming that +in each case the the diffusion satisfies + + align:start position:0% +in each case the the diffusion satisfies + + + align:start position:0% +in each case the the diffusion satisfies +the the gaussing + + align:start position:0% +the the gaussing + + + align:start position:0% +the the gaussing +assumptions what we'll typically find as + + align:start position:0% +assumptions what we'll typically find as + + + align:start position:0% +assumptions what we'll typically find as +you go through a whole process is that + + align:start position:0% +you go through a whole process is that + + + align:start position:0% +you go through a whole process is that +the some of the processing steps may be + + align:start position:0% +the some of the processing steps may be + + + align:start position:0% +the some of the processing steps may be +negligible and that's because the + + align:start position:0% +negligible and that's because the + + + align:start position:0% +negligible and that's because the +diffusion coefficient in this formula is + + align:start position:0% +diffusion coefficient in this formula is + + + align:start position:0% +diffusion coefficient in this formula is +exponentially activated uh or it varies + + align:start position:0% +exponentially activated uh or it varies + + + align:start position:0% +exponentially activated uh or it varies +with temperature exponential so the + + align:start position:0% +with temperature exponential so the + + + align:start position:0% +with temperature exponential so the +highest temperature steps in the process + + align:start position:0% +highest temperature steps in the process + + + align:start position:0% +highest temperature steps in the process +typically dominate um it's not always + + align:start position:0% +typically dominate um it's not always + + + align:start position:0% +typically dominate um it's not always +the case for example when we talk about + + align:start position:0% +the case for example when we talk about + + + align:start position:0% +the case for example when we talk about +trans enhanced diffusion uh we see + + align:start position:0% +trans enhanced diffusion uh we see + + + align:start position:0% +trans enhanced diffusion uh we see +that's not the case but for normal + + align:start position:0% +that's not the case but for normal + + + align:start position:0% +that's not the case but for normal +diffusion you expect the highest + + align:start position:0% +diffusion you expect the highest + + + align:start position:0% +diffusion you expect the highest +temperature steps to dominate this + + align:start position:0% +temperature steps to dominate this + + + align:start position:0% +temperature steps to dominate this +equation and so you can usually zoom in + + align:start position:0% +equation and so you can usually zoom in + + + align:start position:0% +equation and so you can usually zoom in +on those as being the ones that that + + align:start position:0% +on those as being the ones that that + + + align:start position:0% +on those as being the ones that that +primarily determine the DT product and + + align:start position:0% +primarily determine the DT product and + + + align:start position:0% +primarily determine the DT product and +therefore the shape of the + + align:start position:0% +therefore the shape of the + + + align:start position:0% +therefore the shape of the +profile one thing you have we have to be + + align:start position:0% +profile one thing you have we have to be + + + align:start position:0% +profile one thing you have we have to be +aware of is that this uh gaussian + + align:start position:0% +aware of is that this uh gaussian + + + align:start position:0% +aware of is that this uh gaussian +solution we've been talking about only + + align:start position:0% +solution we've been talking about only + + + align:start position:0% +solution we've been talking about only +holds if the Delta function + + align:start position:0% +holds if the Delta function + + + align:start position:0% +holds if the Delta function +approximation for the initial profile is + + align:start position:0% +approximation for the initial profile is + + + align:start position:0% +approximation for the initial profile is +reasonable we talked about this last + + align:start position:0% +reasonable we talked about this last + + + align:start position:0% +reasonable we talked about this last +time so it holds in the case where the + + align:start position:0% +time so it holds in the case where the + + + align:start position:0% +time so it holds in the case where the +width of the profile um initially when + + align:start position:0% +width of the profile um initially when + + + align:start position:0% +width of the profile um initially when +you start is small compared to the the + + align:start position:0% +you start is small compared to the the + + + align:start position:0% +you start is small compared to the the +final width or compared to the total um + + align:start position:0% +final width or compared to the total um + + + align:start position:0% +final width or compared to the total um +DT if that uh assumption is is not valid + + align:start position:0% +DT if that uh assumption is is not valid + + + align:start position:0% +DT if that uh assumption is is not valid +then and we don't have a simple uh uh + + align:start position:0% +then and we don't have a simple uh uh + + + align:start position:0% +then and we don't have a simple uh uh +ging solution + + align:start position:0% + + + + align:start position:0% + +necessarily okay let's go on to slide + + align:start position:0% +necessarily okay let's go on to slide + + + align:start position:0% +necessarily okay let's go on to slide +number + + align:start position:0% +number + + + align:start position:0% +number +six and uh here we're going to go + + align:start position:0% +six and uh here we're going to go + + + align:start position:0% +six and uh here we're going to go +through um some principles and examples + + align:start position:0% +through um some principles and examples + + + align:start position:0% +through um some principles and examples +of the design of diffuse layers so what + + align:start position:0% +of the design of diffuse layers so what + + + align:start position:0% +of the design of diffuse layers so what +we want to do is as as an engineer uh + + align:start position:0% +we want to do is as as an engineer uh + + + align:start position:0% +we want to do is as as an engineer uh +process engineer or working with Device + + align:start position:0% +process engineer or working with Device + + + align:start position:0% +process engineer or working with Device +engineers we want to uh typically design + + align:start position:0% +engineers we want to uh typically design + + + align:start position:0% +engineers we want to uh typically design +a diffusion process um or a prep in + + align:start position:0% +a diffusion process um or a prep in + + + align:start position:0% +a diffusion process um or a prep in +diffusion in a driving process so that + + align:start position:0% +diffusion in a driving process so that + + + align:start position:0% +diffusion in a driving process so that +we end up with a certain sheet + + align:start position:0% +we end up with a certain sheet + + + align:start position:0% +we end up with a certain sheet +resistance that's required electrically + + align:start position:0% +resistance that's required electrically + + + align:start position:0% +resistance that's required electrically +um by the uh by the + + align:start position:0% +um by the uh by the + + + align:start position:0% +um by the uh by the +device so that's that's sort of the uh + + align:start position:0% +device so that's that's sort of the uh + + + align:start position:0% +device so that's that's sort of the uh +the goal of uh of this section and I'm + + align:start position:0% +the goal of uh of this section and I'm + + + align:start position:0% +the goal of uh of this section and I'm +showing on the le- hand side just the + + align:start position:0% +showing on the le- hand side just the + + + align:start position:0% +showing on the le- hand side just the +example of um a cube of silicon where + + align:start position:0% +example of um a cube of silicon where + + + align:start position:0% +example of um a cube of silicon where +the top region is colored in Orange and + + align:start position:0% +the top region is colored in Orange and + + + align:start position:0% +the top region is colored in Orange and +that is the little sheet uh through + + align:start position:0% +that is the little sheet uh through + + + align:start position:0% +that is the little sheet uh through +which we're going to be passing uh a + + align:start position:0% +which we're going to be passing uh a + + + align:start position:0% +which we're going to be passing uh a +current and measuring the voltage and uh + + align:start position:0% +current and measuring the voltage and uh + + + align:start position:0% +current and measuring the voltage and uh +the uh this little uh she has a + + align:start position:0% +the uh this little uh she has a + + + align:start position:0% +the uh this little uh she has a +particular geometry what we're going to + + align:start position:0% +particular geometry what we're going to + + + align:start position:0% +particular geometry what we're going to +consider is the case where the uh + + align:start position:0% +consider is the case where the uh + + + align:start position:0% +consider is the case where the uh +length of this resistor um is actually + + align:start position:0% +length of this resistor um is actually + + + align:start position:0% +length of this resistor um is actually +equal to its its width so it's uh it's a + + align:start position:0% +equal to its its width so it's uh it's a + + + align:start position:0% +equal to its its width so it's uh it's a +square and it has Dimension W by + + align:start position:0% +square and it has Dimension W by + + + align:start position:0% +square and it has Dimension W by +W um and so we're going to define the + + align:start position:0% +W um and so we're going to define the + + + align:start position:0% +W um and so we're going to define the +sheet resistance uh of this function + + align:start position:0% +sheet resistance uh of this function + + + align:start position:0% +sheet resistance uh of this function +last time we talked about it um as being + + align:start position:0% +last time we talked about it um as being + + + align:start position:0% +last time we talked about it um as being +the resistivity which is an intrinsic + + align:start position:0% +the resistivity which is an intrinsic + + + align:start position:0% +the resistivity which is an intrinsic +property of the material depending on + + align:start position:0% +property of the material depending on + + + align:start position:0% +property of the material depending on +how it's doped in BRS divided by XJ The + + align:start position:0% +how it's doped in BRS divided by XJ The + + + align:start position:0% +how it's doped in BRS divided by XJ The +Junction depth you can see XJ and Mark + + align:start position:0% +Junction depth you can see XJ and Mark + + + align:start position:0% +Junction depth you can see XJ and Mark +on the left left hand side and the units + + align:start position:0% +on the left left hand side and the units + + + align:start position:0% +on the left left hand side and the units +of that sheet resistance then are um + + align:start position:0% +of that sheet resistance then are um + + + align:start position:0% +of that sheet resistance then are um +given it to be ohms per + + align:start position:0% +given it to be ohms per + + + align:start position:0% +given it to be ohms per +square so so the sheet resistance is + + align:start position:0% +square so so the sheet resistance is + + + align:start position:0% +square so so the sheet resistance is +indeed the resistance r that you would + + align:start position:0% +indeed the resistance r that you would + + + align:start position:0% +indeed the resistance r that you would +get in a resistor made of one square + + align:start position:0% +get in a resistor made of one square + + + align:start position:0% +get in a resistor made of one square +uh of this material and we you can + + align:start position:0% +uh of this material and we you can + + + align:start position:0% +uh of this material and we you can +easily write it as uh Roman R subs or uh + + align:start position:0% +easily write it as uh Roman R subs or uh + + + align:start position:0% +easily write it as uh Roman R subs or uh +row Greek the Greek letter row SS and uh + + align:start position:0% +row Greek the Greek letter row SS and uh + + + align:start position:0% +row Greek the Greek letter row SS and uh +uh the S indicating is for Sheet the + + align:start position:0% +uh the S indicating is for Sheet the + + + align:start position:0% +uh the S indicating is for Sheet the +resistivity row remember is given by one + + align:start position:0% +resistivity row remember is given by one + + + align:start position:0% +resistivity row remember is given by one +over Q electronic charge times the car + + align:start position:0% +over Q electronic charge times the car + + + align:start position:0% +over Q electronic charge times the car +concentration n times Mobility which is + + align:start position:0% +concentration n times Mobility which is + + + align:start position:0% +concentration n times Mobility which is +in general a function of N and the + + align:start position:0% +in general a function of N and the + + + align:start position:0% +in general a function of N and the +resistivity has units of on centimeter + + align:start position:0% +resistivity has units of on centimeter + + + align:start position:0% +resistivity has units of on centimeter +XJ has units of centimeter they cancel + + align:start position:0% +XJ has units of centimeter they cancel + + + align:start position:0% +XJ has units of centimeter they cancel +out with a sheet resistance in ohms per + + align:start position:0% +out with a sheet resistance in ohms per + + + align:start position:0% +out with a sheet resistance in ohms per +square um that's all + + align:start position:0% +square um that's all + + + align:start position:0% +square um that's all +reasonably uh intuitive in assuming you + + align:start position:0% +reasonably uh intuitive in assuming you + + + align:start position:0% +reasonably uh intuitive in assuming you +have a constantly doped a constant doped + + align:start position:0% +have a constantly doped a constant doped + + + align:start position:0% +have a constantly doped a constant doped +um layer for if a layer is non-uniformly + + align:start position:0% +um layer for if a layer is non-uniformly + + + align:start position:0% +um layer for if a layer is non-uniformly +doped you need to integrate uh the uh + + align:start position:0% +doped you need to integrate uh the uh + + + align:start position:0% +doped you need to integrate uh the uh +the doping uh profile times the the + + align:start position:0% +the doping uh profile times the the + + + align:start position:0% +the doping uh profile times the the +mobility in order to calculate the sheet + + align:start position:0% +mobility in order to calculate the sheet + + + align:start position:0% +mobility in order to calculate the sheet +resistance so the equation shown in near + + align:start position:0% +resistance so the equation shown in near + + + align:start position:0% +resistance so the equation shown in near +the bottom of the slide say sheet + + align:start position:0% +the bottom of the slide say sheet + + + align:start position:0% +the bottom of the slide say sheet +resistance uh can be obtained by one + + align:start position:0% +resistance uh can be obtained by one + + + align:start position:0% +resistance uh can be obtained by one +over the integral Q * the integral from + + align:start position:0% +over the integral Q * the integral from + + + align:start position:0% +over the integral Q * the integral from +zero to the junction depth of a doping + + align:start position:0% +zero to the junction depth of a doping + + + align:start position:0% +zero to the junction depth of a doping +of the car concentration profile n of X + + align:start position:0% +of the car concentration profile n of X + + + align:start position:0% +of the car concentration profile n of X +or the doping profile minus NB or NB is + + align:start position:0% +or the doping profile minus NB or NB is + + + align:start position:0% +or the doping profile minus NB or NB is +the background concentration that tells + + align:start position:0% +the background concentration that tells + + + align:start position:0% +the background concentration that tells +you where uh when you cut off the + + align:start position:0% +you where uh when you cut off the + + + align:start position:0% +you where uh when you cut off the +electron concentration that quantity uh + + align:start position:0% +electron concentration that quantity uh + + + align:start position:0% +electron concentration that quantity uh +times the mobility which is in general + + align:start position:0% +times the mobility which is in general + + + align:start position:0% +times the mobility which is in general +function of of of n uh DX + + align:start position:0% +function of of of n uh DX + + + align:start position:0% +function of of of n uh DX +integrated um so that's what you would + + align:start position:0% +integrated um so that's what you would + + + align:start position:0% +integrated um so that's what you would +do in the case of a non-uniformly doped + + align:start position:0% +do in the case of a non-uniformly doped + + + align:start position:0% +do in the case of a non-uniformly doped +layer with the dope and concentrations + + align:start position:0% +layer with the dope and concentrations + + + align:start position:0% +layer with the dope and concentrations +varying in + + align:start position:0% +varying in + + + align:start position:0% +varying in +thickness uh now it turns out this + + align:start position:0% +thickness uh now it turns out this + + + align:start position:0% +thickness uh now it turns out this +equation uh you can solve it yourself + + align:start position:0% +equation uh you can solve it yourself + + + align:start position:0% +equation uh you can solve it yourself +but this equation has already been + + align:start position:0% +but this equation has already been + + + align:start position:0% +but this equation has already been +numerically integrated uh by Irwin for + + align:start position:0% +numerically integrated uh by Irwin for + + + align:start position:0% +numerically integrated uh by Irwin for +um a couple of different analytical + + align:start position:0% +um a couple of different analytical + + + align:start position:0% +um a couple of different analytical +profiles in particular the case of the + + align:start position:0% +profiles in particular the case of the + + + align:start position:0% +profiles in particular the case of the +ging and the complimentary error + + align:start position:0% +ging and the complimentary error + + + align:start position:0% +ging and the complimentary error +function profiles and those uh the + + align:start position:0% +function profiles and those uh the + + + align:start position:0% +function profiles and those uh the +solutions to those integrals are given + + align:start position:0% +solutions to those integrals are given + + + align:start position:0% +solutions to those integrals are given +in your text uh either in chapter 7even + + align:start position:0% +in your text uh either in chapter 7even + + + align:start position:0% +in your text uh either in chapter 7even +or there's also an appendix where the + + align:start position:0% +or there's also an appendix where the + + + align:start position:0% +or there's also an appendix where the +solutions are given so let's go on to uh + + align:start position:0% +solutions are given so let's go on to uh + + + align:start position:0% +solutions are given so let's go on to uh +slide number + + align:start position:0% +slide number + + + align:start position:0% +slide number +seven and at the top of the slide we're + + align:start position:0% +seven and at the top of the slide we're + + + align:start position:0% +seven and at the top of the slide we're +showing an example of our wind curves + + align:start position:0% +showing an example of our wind curves + + + align:start position:0% +showing an example of our wind curves +for the particular case of the + + align:start position:0% +for the particular case of the + + + align:start position:0% +for the particular case of the +pype uh Gan profiles in an end type + + align:start position:0% +pype uh Gan profiles in an end type + + + align:start position:0% +pype uh Gan profiles in an end type +background and what you see uh in these + + align:start position:0% +background and what you see uh in these + + + align:start position:0% +background and what you see uh in these +curves on the uh Y axis is a Surface + + align:start position:0% +curves on the uh Y axis is a Surface + + + align:start position:0% +curves on the uh Y axis is a Surface +concentration so that would be C subs + + align:start position:0% +concentration so that would be C subs + + + align:start position:0% +concentration so that would be C subs +and adoms P centimeter the xaxis now is + + align:start position:0% +and adoms P centimeter the xaxis now is + + + align:start position:0% +and adoms P centimeter the xaxis now is +effective conductivity and it has units + + align:start position:0% +effective conductivity and it has units + + + align:start position:0% +effective conductivity and it has units +of uh ohm centimeter the minus + + align:start position:0% +of uh ohm centimeter the minus + + + align:start position:0% +of uh ohm centimeter the minus +one um so that's the FX axis if you just + + align:start position:0% +one um so that's the FX axis if you just + + + align:start position:0% +one um so that's the FX axis if you just +go to the bottom of the slide uh + + align:start position:0% +go to the bottom of the slide uh + + + align:start position:0% +go to the bottom of the slide uh +thinking about it that is the effective + + align:start position:0% +thinking about it that is the effective + + + align:start position:0% +thinking about it that is the effective +average conductivity the inverse of the + + align:start position:0% +average conductivity the inverse of the + + + align:start position:0% +average conductivity the inverse of the +average resistivity so we can write this + + align:start position:0% +average resistivity so we can write this + + + align:start position:0% +average resistivity so we can write this +as a sigma bar and it's equal to a one + + align:start position:0% +as a sigma bar and it's equal to a one + + + align:start position:0% +as a sigma bar and it's equal to a one +over the product of row sub s times uh + + align:start position:0% +over the product of row sub s times uh + + + align:start position:0% +over the product of row sub s times uh +XJ so it's one over the sheet the + + align:start position:0% +XJ so it's one over the sheet the + + + align:start position:0% +XJ so it's one over the sheet the +product the sheet resistance times the + + align:start position:0% +product the sheet resistance times the + + + align:start position:0% +product the sheet resistance times the +junction deck um so there are kind of + + align:start position:0% +junction deck um so there are kind of + + + align:start position:0% +junction deck um so there are kind of +three key parameters we need to identify + + align:start position:0% +three key parameters we need to identify + + + align:start position:0% +three key parameters we need to identify +and using these curves there's a surface + + align:start position:0% +and using these curves there's a surface + + + align:start position:0% +and using these curves there's a surface +concentration which is the y- + + align:start position:0% +concentration which is the y- + + + align:start position:0% +concentration which is the y- +axis uh in the profile there is again + + align:start position:0% +axis uh in the profile there is again + + + align:start position:0% +axis uh in the profile there is again +this is for a particular type this for a + + align:start position:0% +this is for a particular type this for a + + + align:start position:0% +this is for a particular type this for a +gum profile there is the sheet + + align:start position:0% +gum profile there is the sheet + + + align:start position:0% +gum profile there is the sheet +resistance um which is uh coming into + + align:start position:0% +resistance um which is uh coming into + + + align:start position:0% +resistance um which is uh coming into +this effective conductivity that's + + align:start position:0% +this effective conductivity that's + + + align:start position:0% +this effective conductivity that's +really part of the x-axis and there's + + align:start position:0% +really part of the x-axis and there's + + + align:start position:0% +really part of the x-axis and there's +the junction depth so the x-axis has + + align:start position:0% +the junction depth so the x-axis has + + + align:start position:0% +the junction depth so the x-axis has +sheet resistance and Junction depth um + + align:start position:0% +sheet resistance and Junction depth um + + + align:start position:0% +sheet resistance and Junction depth um +built into it the uh and now the + + align:start position:0% +built into it the uh and now the + + + align:start position:0% +built into it the uh and now the +metallurgical Junction is the place the + + align:start position:0% +metallurgical Junction is the place the + + + align:start position:0% +metallurgical Junction is the place the +point in depth where the Cal + + align:start position:0% +point in depth where the Cal + + + align:start position:0% +point in depth where the Cal +concentration in of the uh in the + + align:start position:0% +concentration in of the uh in the + + + align:start position:0% +concentration in of the uh in the +diffused region of the diffused dopin + + align:start position:0% +diffused region of the diffused dopin + + + align:start position:0% +diffused region of the diffused dopin +equals the background concentration + + align:start position:0% +equals the background concentration + + + align:start position:0% +equals the background concentration +CB and we'll do an example shortly after + + align:start position:0% +CB and we'll do an example shortly after + + + align:start position:0% +CB and we'll do an example shortly after +this um where you can see how these uh + + align:start position:0% +this um where you can see how these uh + + + align:start position:0% +this um where you can see how these uh +curves are used but each curve different + + align:start position:0% +curves are used but each curve different + + + align:start position:0% +curves are used but each curve different +color is for a different background uh + + align:start position:0% +color is for a different background uh + + + align:start position:0% +color is for a different background uh +concentration uh so this basically tells + + align:start position:0% +concentration uh so this basically tells + + + align:start position:0% +concentration uh so this basically tells +you that you can take these three key + + align:start position:0% +you that you can take these three key + + + align:start position:0% +you that you can take these three key +parameters and uh uh they have a unique + + align:start position:0% +parameters and uh uh they have a unique + + + align:start position:0% +parameters and uh uh they have a unique +relationship among themselves for the + + align:start position:0% +relationship among themselves for the + + + align:start position:0% +relationship among themselves for the +particular case uh where the shape of + + align:start position:0% +particular case uh where the shape of + + + align:start position:0% +particular case uh where the shape of +the profile is known in this case it's + + align:start position:0% +the profile is known in this case it's + + + align:start position:0% +the profile is known in this case it's +gum so in fact let's go on to slide + + align:start position:0% +gum so in fact let's go on to slide + + + align:start position:0% +gum so in fact let's go on to slide +number eight we're going to walk through + + align:start position:0% +number eight we're going to walk through + + + align:start position:0% +number eight we're going to walk through +the best way to uh understand these ear + + align:start position:0% +the best way to uh understand these ear + + + align:start position:0% +the best way to uh understand these ear +WIS curves is go do an + + align:start position:0% +WIS curves is go do an + + + align:start position:0% +WIS curves is go do an +example and what we're asked to do in + + align:start position:0% +example and what we're asked to do in + + + align:start position:0% +example and what we're asked to do in +this example is to calculate the + + align:start position:0% +this example is to calculate the + + + align:start position:0% +this example is to calculate the +drive-in conditions which means the + + align:start position:0% +drive-in conditions which means the + + + align:start position:0% +drive-in conditions which means the +temperature uh and the time to produce a + + align:start position:0% +temperature uh and the time to produce a + + + align:start position:0% +temperature uh and the time to produce a +seamoss uh P well so it's a p type a + + align:start position:0% +seamoss uh P well so it's a p type a + + + align:start position:0% +seamoss uh P well so it's a p type a +region it's called a p well of a certain + + align:start position:0% +region it's called a p well of a certain + + + align:start position:0% +region it's called a p well of a certain +thickness and and um uh what we want to + + align:start position:0% +thickness and and um uh what we want to + + + align:start position:0% +thickness and and um uh what we want to +do we're told that the constraint is the + + align:start position:0% +do we're told that the constraint is the + + + align:start position:0% +do we're told that the constraint is the +KET resistance of that P well shouldn't + + align:start position:0% +KET resistance of that P well shouldn't + + + align:start position:0% +KET resistance of that P well shouldn't +be 900 ohms per + + align:start position:0% +be 900 ohms per + + + align:start position:0% +be 900 ohms per +square okay and it has to have a certain + + align:start position:0% +square okay and it has to have a certain + + + align:start position:0% +square okay and it has to have a certain +Junction depth which is shown + + align:start position:0% +Junction depth which is shown + + + align:start position:0% +Junction depth which is shown +schematically in the figure XJ to be + + align:start position:0% +schematically in the figure XJ to be + + + align:start position:0% +schematically in the figure XJ to be +three microns uh and that XJ again is + + align:start position:0% +three microns uh and that XJ again is + + + align:start position:0% +three microns uh and that XJ again is +the point where the brwn concentration + + align:start position:0% +the point where the brwn concentration + + + align:start position:0% +the point where the brwn concentration +then will reach the background + + align:start position:0% +then will reach the background + + + align:start position:0% +then will reach the background +concentration which is um uh given by uh + + align:start position:0% +concentration which is um uh given by uh + + + align:start position:0% +concentration which is um uh given by uh +10 15 cubic cm here so again we're + + align:start position:0% +10 15 cubic cm here so again we're + + + align:start position:0% +10 15 cubic cm here so again we're +informing a PO by ion implanting + + align:start position:0% +informing a PO by ion implanting + + + align:start position:0% +informing a PO by ion implanting +Bond um into this uh into the region + + align:start position:0% +Bond um into this uh into the region + + + align:start position:0% +Bond um into this uh into the region +onto the wafer and the region on the + + align:start position:0% +onto the wafer and the region on the + + + align:start position:0% +onto the wafer and the region on the +left is blocked so we're just being in + + align:start position:0% +left is blocked so we're just being in + + + align:start position:0% +left is blocked so we're just being in +one region and typically you would + + align:start position:0% +one region and typically you would + + + align:start position:0% +one region and typically you would +implant um Boron at a certain dose say + + align:start position:0% +implant um Boron at a certain dose say + + + align:start position:0% +implant um Boron at a certain dose say +10 of the 13th and energy and then we + + align:start position:0% +10 of the 13th and energy and then we + + + align:start position:0% +10 of the 13th and energy and then we +want to drive that in and we're + + align:start position:0% +want to drive that in and we're + + + align:start position:0% +want to drive that in and we're +interested in the driving conditions + + align:start position:0% +interested in the driving conditions + + + align:start position:0% +interested in the driving conditions +what + + align:start position:0% +what + + + align:start position:0% +what +temperature in time will we need to get + + align:start position:0% +temperature in time will we need to get + + + align:start position:0% +temperature in time will we need to get +it to go that far and to have a + + align:start position:0% +it to go that far and to have a + + + align:start position:0% +it to go that far and to have a +particular um sheet + + align:start position:0% + + + + align:start position:0% + +resistance uh and we're going to use + + align:start position:0% +resistance uh and we're going to use + + + align:start position:0% +resistance uh and we're going to use +Irwin's curves to do your so let's look + + align:start position:0% +Irwin's curves to do your so let's look + + + align:start position:0% +Irwin's curves to do your so let's look +on slide number uh + + align:start position:0% +on slide number uh + + + align:start position:0% +on slide number uh +nine um so these are the constraints + + align:start position:0% +nine um so these are the constraints + + + align:start position:0% +nine um so these are the constraints +again repeated the sheet resistance is + + align:start position:0% +again repeated the sheet resistance is + + + align:start position:0% +again repeated the sheet resistance is +900 ohms per square The Junction depth + + align:start position:0% +900 ohms per square The Junction depth + + + align:start position:0% +900 ohms per square The Junction depth +has to be three microns and the + + align:start position:0% +has to be three microns and the + + + align:start position:0% +has to be three microns and the +background concentration either NB or uh + + align:start position:0% +background concentration either NB or uh + + + align:start position:0% +background concentration either NB or uh +substrate concentration maybe WR NBC is + + align:start position:0% +substrate concentration maybe WR NBC is + + + align:start position:0% +substrate concentration maybe WR NBC is + + align:start position:0% + + + align:start position:0% +15th so given the requirements that we + + align:start position:0% +15th so given the requirements that we + + + align:start position:0% +15th so given the requirements that we +have been uh told I can actually + + align:start position:0% +have been uh told I can actually + + + align:start position:0% +have been uh told I can actually +immediately find the x-axis on the urban + + align:start position:0% +immediately find the x-axis on the urban + + + align:start position:0% +immediately find the x-axis on the urban +curve with the average connectivity + + align:start position:0% +curve with the average connectivity + + + align:start position:0% +curve with the average connectivity +layer it's just one over the shapeless + + align:start position:0% +layer it's just one over the shapeless + + + align:start position:0% +layer it's just one over the shapeless +distance times + + align:start position:0% +distance times + + + align:start position:0% +distance times +XJ so the average connectivity + + align:start position:0% +XJ so the average connectivity + + + align:start position:0% +XJ so the average connectivity +calculates out to the 3.7 ohm cim minus + + align:start position:0% +calculates out to the 3.7 ohm cim minus + + + align:start position:0% +calculates out to the 3.7 ohm cim minus +one um we can now from Irwin's curve we + + align:start position:0% +one um we can now from Irwin's curve we + + + align:start position:0% +one um we can now from Irwin's curve we +can obtain assuming this the galy uh + + align:start position:0% +can obtain assuming this the galy uh + + + align:start position:0% +can obtain assuming this the galy uh +that's assumption we we need to make at + + align:start position:0% +that's assumption we we need to make at + + + align:start position:0% +that's assumption we we need to make at +this point which we'll show is + + align:start position:0% +this point which we'll show is + + + align:start position:0% +this point which we'll show is +reasonable later we can then obtain the + + align:start position:0% +reasonable later we can then obtain the + + + align:start position:0% +reasonable later we can then obtain the +surface concentration so if in order for + + align:start position:0% +surface concentration so if in order for + + + align:start position:0% +surface concentration so if in order for +me knowing the shape of the Gan + + align:start position:0% +me knowing the shape of the Gan + + + align:start position:0% +me knowing the shape of the Gan +basically IR intervals tells us that the + + align:start position:0% +basically IR intervals tells us that the + + + align:start position:0% +basically IR intervals tells us that the +service concentration has to be about 4 + + align:start position:0% +service concentration has to be about 4 + + + align:start position:0% +service concentration has to be about 4 +* 10 17th per cubic + + align:start position:0% +* 10 17th per cubic + + + align:start position:0% +* 10 17th per cubic +cm in order to achieve an average + + align:start position:0% +cm in order to achieve an average + + + align:start position:0% +cm in order to achieve an average +conductivity that has been specified of + + align:start position:0% +conductivity that has been specified of + + + align:start position:0% +conductivity that has been specified of +3.7 um uh assuming the junction depth is + + align:start position:0% +3.7 um uh assuming the junction depth is + + + align:start position:0% +3.7 um uh assuming the junction depth is +three microns so that's and if you can + + align:start position:0% +three microns so that's and if you can + + + align:start position:0% +three microns so that's and if you can +you want to see that how we actually do + + align:start position:0% +you want to see that how we actually do + + + align:start position:0% +you want to see that how we actually do +that you can go on to slide number 10 + + align:start position:0% +that you can go on to slide number 10 + + + align:start position:0% +that you can go on to slide number 10 +and this actually shows how the curve we + + align:start position:0% +and this actually shows how the curve we + + + align:start position:0% +and this actually shows how the curve we +used um again this is for a ptype + + align:start position:0% +used um again this is for a ptype + + + align:start position:0% +used um again this is for a ptype +gussian profile and all we've done is is + + align:start position:0% +gussian profile and all we've done is is + + + align:start position:0% +gussian profile and all we've done is is +uh on the x-axis picked out it's a + + align:start position:0% +uh on the x-axis picked out it's a + + + align:start position:0% +uh on the x-axis picked out it's a +little hard because this is a log long + + align:start position:0% +little hard because this is a log long + + + align:start position:0% +little hard because this is a log long +plot on the x-axis picked out the + + align:start position:0% +plot on the x-axis picked out the + + + align:start position:0% +plot on the x-axis picked out the +average conductivity to be + + align:start position:0% +average conductivity to be + + + align:start position:0% +average conductivity to be +3.7 and it's a little tricky to find + + align:start position:0% +3.7 and it's a little tricky to find + + + align:start position:0% +3.7 and it's a little tricky to find +that but uh you can and then you see you + + align:start position:0% +that but uh you can and then you see you + + + align:start position:0% +that but uh you can and then you see you +read off the y- AIS as shown by that uh + + align:start position:0% +read off the y- AIS as shown by that uh + + + align:start position:0% +read off the y- AIS as shown by that uh +horizontal line surface concentration + + align:start position:0% +horizontal line surface concentration + + + align:start position:0% +horizontal line surface concentration +about four * 10 the 17th and again we + + align:start position:0% +about four * 10 the 17th and again we + + + align:start position:0% +about four * 10 the 17th and again we +have multiple curves we can choose I + + align:start position:0% +have multiple curves we can choose I + + + align:start position:0% +have multiple curves we can choose I +choose to use the orange + + align:start position:0% +choose to use the orange + + + align:start position:0% +choose to use the orange +curve uh which is for the case of a + + align:start position:0% +curve uh which is for the case of a + + + align:start position:0% +curve uh which is for the case of a +background concentration in this example + + align:start position:0% +background concentration in this example + + + align:start position:0% +background concentration in this example +of 10 the + + align:start position:0% +of 10 the + + + align:start position:0% +of 10 the +15th uh if the background concentration + + align:start position:0% +15th uh if the background concentration + + + align:start position:0% +15th uh if the background concentration +say had been uh a little bit higher say + + align:start position:0% +say had been uh a little bit higher say + + + align:start position:0% +say had been uh a little bit higher say +10 the 16th or um 10 the 17th what you + + align:start position:0% +10 the 16th or um 10 the 17th what you + + + align:start position:0% +10 the 16th or um 10 the 17th what you +see would have happened um is that the + + align:start position:0% +see would have happened um is that the + + + align:start position:0% +see would have happened um is that the +uh the surface concentration would have + + align:start position:0% +uh the surface concentration would have + + + align:start position:0% +uh the surface concentration would have +actually moved down a little bit uh on + + align:start position:0% +actually moved down a little bit uh on + + + align:start position:0% +actually moved down a little bit uh on +the y- AIS it would have be intersect a + + align:start position:0% +the y- AIS it would have be intersect a + + + align:start position:0% +the y- AIS it would have be intersect a +slightly different + + align:start position:0% +slightly different + + + align:start position:0% +slightly different +curve okay so that's how we come up with + + align:start position:0% +curve okay so that's how we come up with + + + align:start position:0% +curve okay so that's how we come up with +the um the surface + + align:start position:0% +the um the surface + + + align:start position:0% +the um the surface +concentration + + align:start position:0% +concentration + + + align:start position:0% +concentration +so let's go on to uh slide 11 and + + align:start position:0% +so let's go on to uh slide 11 and + + + align:start position:0% +so let's go on to uh slide 11 and +thinking about that surface + + align:start position:0% +thinking about that surface + + + align:start position:0% +thinking about that surface +concentration C Subs we know it's well + + align:start position:0% +concentration C Subs we know it's well + + + align:start position:0% +concentration C Subs we know it's well +below the solent solubility of B and + + align:start position:0% +below the solent solubility of B and + + + align:start position:0% +below the solent solubility of B and +silicon it's only 410 and the + + align:start position:0% +silicon it's only 410 and the + + + align:start position:0% +silicon it's only 410 and the +17th and it's probably likely below the + + align:start position:0% +17th and it's probably likely below the + + + align:start position:0% +17th and it's probably likely below the +value of n subi at the diffusion + + align:start position:0% +value of n subi at the diffusion + + + align:start position:0% +value of n subi at the diffusion +temperature again at a th000 degrees + + align:start position:0% +temperature again at a th000 degrees + + + align:start position:0% +temperature again at a th000 degrees +which is probably somewhere near or a + + align:start position:0% +which is probably somewhere near or a + + + align:start position:0% +which is probably somewhere near or a +minimum temperature you'll be using to + + align:start position:0% +minimum temperature you'll be using to + + + align:start position:0% +minimum temperature you'll be using to +drive this in Andi is about mid 10 to + + align:start position:0% +drive this in Andi is about mid 10 to + + + align:start position:0% +drive this in Andi is about mid 10 to +the 18th and so mid10 to the 17th is + + align:start position:0% +the 18th and so mid10 to the 17th is + + + align:start position:0% +the 18th and so mid10 to the 17th is +well below that so it's it's probably + + align:start position:0% +well below that so it's it's probably + + + align:start position:0% +well below that so it's it's probably +valid then to + + align:start position:0% +valid then to + + + align:start position:0% +valid then to +say that the profile is galxy it's + + align:start position:0% +say that the profile is galxy it's + + + align:start position:0% +say that the profile is galxy it's +probably valid to say that uh it is a + + align:start position:0% +probably valid to say that uh it is a + + + align:start position:0% +probably valid to say that uh it is a +constant diffusivity + + align:start position:0% +constant diffusivity + + + align:start position:0% +constant diffusivity +d uh and therefore we can assume this a + + align:start position:0% +d uh and therefore we can assume this a + + + align:start position:0% +d uh and therefore we can assume this a +gan uh type of solution because it's a + + align:start position:0% +gan uh type of solution because it's a + + + align:start position:0% +gan uh type of solution because it's a +driving so we so we can write down sort + + align:start position:0% +driving so we so we can write down sort + + + align:start position:0% +driving so we so we can write down sort +of by inspection the equation in the + + align:start position:0% +of by inspection the equation in the + + + align:start position:0% +of by inspection the equation in the +center of the the slide which is the Gin + + align:start position:0% +center of the the slide which is the Gin + + + align:start position:0% +center of the the slide which is the Gin +equation um uh and then uh we know that + + align:start position:0% +equation um uh and then uh we know that + + + align:start position:0% +equation um uh and then uh we know that +uh at the point where xal XJ the uh car + + align:start position:0% +uh at the point where xal XJ the uh car + + + align:start position:0% +uh at the point where xal XJ the uh car +concentration or the doping + + align:start position:0% +concentration or the doping + + + align:start position:0% +concentration or the doping +concentration Cen of the Boron reaches + + align:start position:0% +concentration Cen of the Boron reaches + + + align:start position:0% +concentration Cen of the Boron reaches +that of the background that's a + + align:start position:0% +that of the background that's a + + + align:start position:0% +that of the background that's a +definitional exj so if you look in the + + align:start position:0% +definitional exj so if you look in the + + + align:start position:0% +definitional exj so if you look in the +middle of this slide we're saying uh the + + align:start position:0% +middle of this slide we're saying uh the + + + align:start position:0% +middle of this slide we're saying uh the +background open Con background + + align:start position:0% +background open Con background + + + align:start position:0% +background open Con background +concentration CBC is equal to the + + align:start position:0% +concentration CBC is equal to the + + + align:start position:0% +concentration CBC is equal to the +surface concentration C sub s which we + + align:start position:0% +surface concentration C sub s which we + + + align:start position:0% +surface concentration C sub s which we +just located which is fam times + + align:start position:0% +just located which is fam times + + + align:start position:0% +just located which is fam times +exponential of the minus XJ S 4 DT + + align:start position:0% +exponential of the minus XJ S 4 DT + + + align:start position:0% +exponential of the minus XJ S 4 DT +that's the definition of + + align:start position:0% +that's the definition of + + + align:start position:0% +that's the definition of +XJ so we know XJ in this equation we + + align:start position:0% +XJ so we know XJ in this equation we + + + align:start position:0% +XJ so we know XJ in this equation we +just found c s we know the background + + align:start position:0% +just found c s we know the background + + + align:start position:0% +just found c s we know the background +open concentration the only thing we + + align:start position:0% +open concentration the only thing we + + + align:start position:0% +open concentration the only thing we +don't know is DT so we can invert that + + align:start position:0% +don't know is DT so we can invert that + + + align:start position:0% +don't know is DT so we can invert that +equation and solve for DT plug in all + + align:start position:0% +equation and solve for DT plug in all + + + align:start position:0% +equation and solve for DT plug in all +the numbers and you get um a DT product + + align:start position:0% +the numbers and you get um a DT product + + + align:start position:0% +the numbers and you get um a DT product +uh in order to obtain this scalan of 3.7 + + align:start position:0% +uh in order to obtain this scalan of 3.7 + + + align:start position:0% +uh in order to obtain this scalan of 3.7 +* 10us 9 cm + + align:start position:0% +* 10us 9 cm + + + align:start position:0% +* 10us 9 cm +s that's the DT product the so-call if + + align:start position:0% +s that's the DT product the so-call if + + + align:start position:0% +s that's the DT product the so-call if +you would like to use the term thermal + + align:start position:0% +you would like to use the term thermal + + + align:start position:0% +you would like to use the term thermal +budget for the drive-in process um so + + align:start position:0% +budget for the drive-in process um so + + + align:start position:0% +budget for the drive-in process um so +that gives us an idea and we don't know + + align:start position:0% +that gives us an idea and we don't know + + + align:start position:0% +that gives us an idea and we don't know +what D is or what T is but we're going + + align:start position:0% +what D is or what T is but we're going + + + align:start position:0% +what D is or what T is but we're going +to design uh a certain + + align:start position:0% +to design uh a certain + + + align:start position:0% +to design uh a certain +temperature and time so we constrain to + + align:start position:0% +temperature and time so we constrain to + + + align:start position:0% +temperature and time so we constrain to +the fact that the D product will be this + + align:start position:0% +the fact that the D product will be this + + + align:start position:0% +the fact that the D product will be this +number so let's go on slide number uh + + align:start position:0% +number so let's go on slide number uh + + + align:start position:0% +number so let's go on slide number uh +number 12 and again I'm repeating the DT + + align:start position:0% +number 12 and again I'm repeating the DT + + + align:start position:0% +number 12 and again I'm repeating the DT +product from the top 3.9 * m minus 9 + + align:start position:0% +product from the top 3.9 * m minus 9 + + + align:start position:0% +product from the top 3.9 * m minus 9 +3.7 uh let's just assume a temperature + + align:start position:0% +3.7 uh let's just assume a temperature + + + align:start position:0% +3.7 uh let's just assume a temperature +and see what happen see what time is + + align:start position:0% +and see what happen see what time is + + + align:start position:0% +and see what happen see what time is +associated with that if it's a + + align:start position:0% +associated with that if it's a + + + align:start position:0% +associated with that if it's a +reasonable amount of time so say uh we + + align:start position:0% +reasonable amount of time so say uh we + + + align:start position:0% +reasonable amount of time so say uh we +know we're diffusing pretty deep down to + + align:start position:0% +know we're diffusing pretty deep down to + + + align:start position:0% +know we're diffusing pretty deep down to +three microns so let's just say we + + align:start position:0% +three microns so let's just say we + + + align:start position:0% +three microns so let's just say we +assume we drive in at 1100 cenade and + + align:start position:0% +assume we drive in at 1100 cenade and + + + align:start position:0% +assume we drive in at 1100 cenade and +then you can look + + align:start position:0% +then you can look + + + align:start position:0% +then you can look +up uh from your plots or you can + + align:start position:0% +up uh from your plots or you can + + + align:start position:0% +up uh from your plots or you can +calculate diffusivity of B 1100 it's + + align:start position:0% +calculate diffusivity of B 1100 it's + + + align:start position:0% +calculate diffusivity of B 1100 it's +about 1.5 * 10- 13 7 Square per second + + align:start position:0% +about 1.5 * 10- 13 7 Square per second + + + align:start position:0% +about 1.5 * 10- 13 7 Square per second +and so then you can solve for time the + + align:start position:0% +and so then you can solve for time the + + + align:start position:0% +and so then you can solve for time the +drive in time calculate that out you get + + align:start position:0% +drive in time calculate that out you get + + + align:start position:0% +drive in time calculate that out you get +about 6.7 hours it's plenty long that + + align:start position:0% +about 6.7 hours it's plenty long that + + + align:start position:0% +about 6.7 hours it's plenty long that +tells you probably from a practical + + align:start position:0% +tells you probably from a practical + + + align:start position:0% +tells you probably from a practical +point of view you would not want to do + + align:start position:0% +point of view you would not want to do + + + align:start position:0% +point of view you would not want to do +this driving any lower temperature + + align:start position:0% +this driving any lower temperature + + + align:start position:0% +this driving any lower temperature +because it would just take two them + + align:start position:0% +because it would just take two them + + + align:start position:0% +because it would just take two them +off okay so um + + align:start position:0% +off okay so um + + + align:start position:0% +off okay so um +now one thing we'd like to to calculate + + align:start position:0% +now one thing we'd like to to calculate + + + align:start position:0% +now one thing we'd like to to calculate +we we have um figured out the surface + + align:start position:0% +we we have um figured out the surface + + + align:start position:0% +we we have um figured out the surface +concentration 's curves and we have the + + align:start position:0% +concentration 's curves and we have the + + + align:start position:0% +concentration 's curves and we have the +DK product it will be interesting to + + align:start position:0% +DK product it will be interesting to + + + align:start position:0% +DK product it will be interesting to +calculate the initial dose or the dose + + align:start position:0% +calculate the initial dose or the dose + + + align:start position:0% +calculate the initial dose or the dose +the area and the curve for the Gan + + align:start position:0% +the area and the curve for the Gan + + + align:start position:0% +the area and the curve for the Gan +profile we have everything we need again + + align:start position:0% +profile we have everything we need again + + + align:start position:0% +profile we have everything we need again +we know the dose Q is the surface + + align:start position:0% +we know the dose Q is the surface + + + align:start position:0% +we know the dose Q is the surface +concentration C sub stimes theun of Pi + + align:start position:0% +concentration C sub stimes theun of Pi + + + align:start position:0% +concentration C sub stimes theun of Pi +DT and we have all those quantities we + + align:start position:0% +DT and we have all those quantities we + + + align:start position:0% +DT and we have all those quantities we +can plug them in and we get Q = to 4.3 * + + align:start position:0% +can plug them in and we get Q = to 4.3 * + + + align:start position:0% +can plug them in and we get Q = to 4.3 * +10 13 that's the end on the + + align:start position:0% +10 13 that's the end on the + + + align:start position:0% +10 13 that's the end on the +gasi uh it's a relatively low dose + + align:start position:0% +gasi uh it's a relatively low dose + + + align:start position:0% +gasi uh it's a relatively low dose +compared to uh implant range so it it's + + align:start position:0% +compared to uh implant range so it it's + + + align:start position:0% +compared to uh implant range so it it's +um they can be implanted so this dose + + align:start position:0% +um they can be implanted so this dose + + + align:start position:0% +um they can be implanted so this dose +can easily be implanted into a very + + align:start position:0% +can easily be implanted into a very + + + align:start position:0% +can easily be implanted into a very +narrow layer close to the surface which + + align:start position:0% +narrow layer close to the surface which + + + align:start position:0% +narrow layer close to the surface which +justifies implicitly that narrow layer + + align:start position:0% +justifies implicitly that narrow layer + + + align:start position:0% +justifies implicitly that narrow layer +might only be a th ACS deep it justifies + + align:start position:0% +might only be a th ACS deep it justifies + + + align:start position:0% +might only be a th ACS deep it justifies +our implicit assumption in using a gin + + align:start position:0% +our implicit assumption in using a gin + + + align:start position:0% +our implicit assumption in using a gin +Pro profile that the initial + + align:start position:0% +Pro profile that the initial + + + align:start position:0% +Pro profile that the initial +distribution would be a Delta function + + align:start position:0% +distribution would be a Delta function + + + align:start position:0% +distribution would be a Delta function +maybe only again few th000 ANS deep and + + align:start position:0% +maybe only again few th000 ANS deep and + + + align:start position:0% +maybe only again few th000 ANS deep and +you're going to a final Junction depth + + align:start position:0% +you're going to a final Junction depth + + + align:start position:0% +you're going to a final Junction depth +that is uh three microns and um + + align:start position:0% +that is uh three microns and um + + + align:start position:0% +that is uh three microns and um +certainly um uh that that scene is + + align:start position:0% +certainly um uh that that scene is + + + align:start position:0% +certainly um uh that that scene is +Justified using the Gan + + align:start position:0% +Justified using the Gan + + + align:start position:0% +Justified using the Gan +profile okay let's go on to uh slide + + align:start position:0% +profile okay let's go on to uh slide + + + align:start position:0% +profile okay let's go on to uh slide +number 13 and now that that was the case + + align:start position:0% +number 13 and now that that was the case + + + align:start position:0% +number 13 and now that that was the case +we just talked aboutum we had implanted + + align:start position:0% +we just talked aboutum we had implanted + + + align:start position:0% +we just talked aboutum we had implanted +the dose let's just take the case where + + align:start position:0% +the dose let's just take the case where + + + align:start position:0% +the dose let's just take the case where +if we used a gas um phase uh uh prep uh + + align:start position:0% +if we used a gas um phase uh uh prep uh + + + align:start position:0% +if we used a gas um phase uh uh prep uh +step as an example to get the uh born + + align:start position:0% +step as an example to get the uh born + + + align:start position:0% +step as an example to get the uh born +initially uh into the wafer and say that + + align:start position:0% +initially uh into the wafer and say that + + + align:start position:0% +initially uh into the wafer and say that +was done at 950 you can then use the + + align:start position:0% +was done at 950 you can then use the + + + align:start position:0% +was done at 950 you can then use the +charts in your book or in the handouts + + align:start position:0% +charts in your book or in the handouts + + + align:start position:0% +charts in your book or in the handouts +to look up the Sol solubility of born at + + align:start position:0% +to look up the Sol solubility of born at + + + align:start position:0% +to look up the Sol solubility of born at +950 and you'll see it's pretty high it's + + align:start position:0% +950 and you'll see it's pretty high it's + + + align:start position:0% +950 and you'll see it's pretty high it's +2.51 + + align:start position:0% +2.51 + + + align:start position:0% +2.51 +20 at that temperature then we can also + + align:start position:0% +20 at that temperature then we can also + + + align:start position:0% +20 at that temperature then we can also +look up the deity it's about 41 Theus + + align:start position:0% +look up the deity it's about 41 Theus + + + align:start position:0% +look up the deity it's about 41 Theus +15 so you can solve for the dose in the + + align:start position:0% +15 so you can solve for the dose in the + + + align:start position:0% +15 so you can solve for the dose in the +complimentary error function profile q + + align:start position:0% +complimentary error function profile q + + + align:start position:0% +complimentary error function profile q +and you have everything you need in that + + align:start position:0% +and you have everything you need in that + + + align:start position:0% +and you have everything you need in that +um equation 2 C Subs overun of Pi of KT + + align:start position:0% +um equation 2 C Subs overun of Pi of KT + + + align:start position:0% +um equation 2 C Subs overun of Pi of KT +and so the time that you were required + + align:start position:0% +and so the time that you were required + + + align:start position:0% +and so the time that you were required +to deposit that dose into the wafer T of + + align:start position:0% +to deposit that dose into the wafer T of + + + align:start position:0% +to deposit that dose into the wafer T of +the prep can be solved and you find + + align:start position:0% +the prep can be solved and you find + + + align:start position:0% +the prep can be solved and you find +about 5.5 + + align:start position:0% +about 5.5 + + + align:start position:0% +about 5.5 +seconds so you now see that the uh DT + + align:start position:0% +seconds so you now see that the uh DT + + + align:start position:0% +seconds so you now see that the uh DT +product of the predi which you can + + align:start position:0% +product of the predi which you can + + + align:start position:0% +product of the predi which you can +calculate it's 5.5 seconds times the + + align:start position:0% +calculate it's 5.5 seconds times the + + + align:start position:0% +calculate it's 5.5 seconds times the +diffusivity at 950 which we see from + + align:start position:0% +diffusivity at 950 which we see from + + + align:start position:0% +diffusivity at 950 which we see from +regardless 4 10us + + align:start position:0% +regardless 4 10us + + + align:start position:0% +regardless 4 10us +so that DT prep is about 2 * 10us + + align:start position:0% +so that DT prep is about 2 * 10us + + + align:start position:0% +so that DT prep is about 2 * 10us +14th uh and comparing that to the DT of + + align:start position:0% +14th uh and comparing that to the DT of + + + align:start position:0% +14th uh and comparing that to the DT of +the drivein which was solved for earlier + + align:start position:0% +the drivein which was solved for earlier + + + align:start position:0% +the drivein which was solved for earlier +which is about 1 and a half time 10us 13 + + align:start position:0% +which is about 1 and a half time 10us 13 + + + align:start position:0% +which is about 1 and a half time 10us 13 +so you know order of magnitude uh + + align:start position:0% +so you know order of magnitude uh + + + align:start position:0% +so you know order of magnitude uh +difference there again this tells that + + align:start position:0% +difference there again this tells that + + + align:start position:0% +difference there again this tells that +the Assumption of gine diffusions is + + align:start position:0% +the Assumption of gine diffusions is + + + align:start position:0% +the Assumption of gine diffusions is +Justified whe even if we done a solid + + align:start position:0% +Justified whe even if we done a solid + + + align:start position:0% +Justified whe even if we done a solid +phase + + align:start position:0% + + + + align:start position:0% + +prep okay so that's uh the end of slide + + align:start position:0% +prep okay so that's uh the end of slide + + + align:start position:0% +prep okay so that's uh the end of slide +13 that sort of gives you an idea of how + + align:start position:0% +13 that sort of gives you an idea of how + + + align:start position:0% +13 that sort of gives you an idea of how +these herban curves can be used to + + align:start position:0% +these herban curves can be used to + + + align:start position:0% +these herban curves can be used to +design a process the alternative you + + align:start position:0% +design a process the alternative you + + + align:start position:0% +design a process the alternative you +could use them is to uh to read off uh + + align:start position:0% +could use them is to uh to read off uh + + + align:start position:0% +could use them is to uh to read off uh +if you go back to just momentarily uh + + align:start position:0% +if you go back to just momentarily uh + + + align:start position:0% +if you go back to just momentarily uh +slide 10 you might the problem might be + + align:start position:0% +slide 10 you might the problem might be + + + align:start position:0% +slide 10 you might the problem might be +specified differently you might be + + align:start position:0% +specified differently you might be + + + align:start position:0% +specified differently you might be +given um you know uh some kind of + + align:start position:0% +given um you know uh some kind of + + + align:start position:0% +given um you know uh some kind of +surface concentration and uh background + + align:start position:0% +surface concentration and uh background + + + align:start position:0% +surface concentration and uh background +concentration have to back out um uh + + align:start position:0% +concentration have to back out um uh + + + align:start position:0% +concentration have to back out um uh +what the effective connectivity of the + + align:start position:0% +what the effective connectivity of the + + + align:start position:0% +what the effective connectivity of the +layer might be so the different ways + + align:start position:0% +layer might be so the different ways + + + align:start position:0% +layer might be so the different ways +that get in with + + align:start position:0% +that get in with + + + align:start position:0% +that get in with +curbs so let's go on now to um slide + + align:start position:0% +curbs so let's go on now to um slide + + + align:start position:0% +curbs so let's go on now to um slide +number 14 and I want to shift gears a + + align:start position:0% +number 14 and I want to shift gears a + + + align:start position:0% +number 14 and I want to shift gears a +little bit because um we have more or + + align:start position:0% +little bit because um we have more or + + + align:start position:0% +little bit because um we have more or +less covered the a few cases for which + + align:start position:0% +less covered the a few cases for which + + + align:start position:0% +less covered the a few cases for which +the um analytic Solutions can be obtain + + align:start position:0% +the um analytic Solutions can be obtain + + + align:start position:0% +the um analytic Solutions can be obtain +and those are important cases but + + align:start position:0% +and those are important cases but + + + align:start position:0% +and those are important cases but +primarily when the dope in concentration + + align:start position:0% +primarily when the dope in concentration + + + align:start position:0% +primarily when the dope in concentration +is low or uh satisfying certain special + + align:start position:0% +is low or uh satisfying certain special + + + align:start position:0% +is low or uh satisfying certain special +conditions like during + + align:start position:0% +conditions like during + + + align:start position:0% +conditions like during +preps it turn it'll turn out there's + + align:start position:0% +preps it turn it'll turn out there's + + + align:start position:0% +preps it turn it'll turn out there's +most cases we cannot solve analytically + + align:start position:0% +most cases we cannot solve analytically + + + align:start position:0% +most cases we cannot solve analytically +so these Solutions have to be obtained + + align:start position:0% +so these Solutions have to be obtained + + + align:start position:0% +so these Solutions have to be obtained +by using computers using numerical + + align:start position:0% +by using computers using numerical + + + align:start position:0% +by using computers using numerical +methods and um so I wanted to introduce + + align:start position:0% +methods and um so I wanted to introduce + + + align:start position:0% +methods and um so I wanted to introduce +you in the next few slides to uh some of + + align:start position:0% +you in the next few slides to uh some of + + + align:start position:0% +you in the next few slides to uh some of +the simplest tight CH numerical methods + + align:start position:0% +the simplest tight CH numerical methods + + + align:start position:0% +the simplest tight CH numerical methods +so you have an idea or a feel for how + + align:start position:0% +so you have an idea or a feel for how + + + align:start position:0% +so you have an idea or a feel for how +you yourself could Implement these + + align:start position:0% +you yourself could Implement these + + + align:start position:0% +you yourself could Implement these +numerical techniques if you need to do + + align:start position:0% +numerical techniques if you need to do + + + align:start position:0% +numerical techniques if you need to do +it and there are uh textbooks on this + + align:start position:0% +it and there are uh textbooks on this + + + align:start position:0% +it and there are uh textbooks on this +topic um in particular if you want to + + align:start position:0% +topic um in particular if you want to + + + align:start position:0% +topic um in particular if you want to +look at more detailed information on + + align:start position:0% +look at more detailed information on + + + align:start position:0% +look at more detailed information on +numerical Solutions of the Fusion + + align:start position:0% +numerical Solutions of the Fusion + + + align:start position:0% +numerical Solutions of the Fusion +equation there's a uh a book by Jay + + align:start position:0% +equation there's a uh a book by Jay + + + align:start position:0% +equation there's a uh a book by Jay +crank called the mathematics and + + align:start position:0% +crank called the mathematics and + + + align:start position:0% +crank called the mathematics and +diffusion has a chapter on numerical + + align:start position:0% +diffusion has a chapter on numerical + + + align:start position:0% +diffusion has a chapter on numerical +methods uh for this particular + + align:start position:0% +methods uh for this particular + + + align:start position:0% +methods uh for this particular +equation the nice thing about numerical + + align:start position:0% +equation the nice thing about numerical + + + align:start position:0% +equation the nice thing about numerical +methods they can be used to solve for + + align:start position:0% +methods they can be used to solve for + + + align:start position:0% +methods they can be used to solve for +arbitrary initial starting profiles so + + align:start position:0% +arbitrary initial starting profiles so + + + align:start position:0% +arbitrary initial starting profiles so +you don't have to make any detailed + + align:start position:0% +you don't have to make any detailed + + + align:start position:0% +you don't have to make any detailed +assumptions arbitrary boundary + + align:start position:0% +assumptions arbitrary boundary + + + align:start position:0% +assumptions arbitrary boundary +conditions and in the case where the + + align:start position:0% +conditions and in the case where the + + + align:start position:0% +conditions and in the case where the +diffusivity varies in space so if you + + align:start position:0% +diffusivity varies in space so if you + + + align:start position:0% +diffusivity varies in space so if you +have a concentration dependent + + align:start position:0% +have a concentration dependent + + + align:start position:0% +have a concentration dependent +diffusivity which will be the case uh + + align:start position:0% +diffusivity which will be the case uh + + + align:start position:0% +diffusivity which will be the case uh +we'll talk about in in later lectures + + align:start position:0% +we'll talk about in in later lectures + + + align:start position:0% +we'll talk about in in later lectures +when the uh car when the dopin + + align:start position:0% +when the uh car when the dopin + + + align:start position:0% +when the uh car when the dopin +concentration is quite high and you can + + align:start position:0% +concentration is quite high and you can + + + align:start position:0% +concentration is quite high and you can +use numerical + + align:start position:0% +use numerical + + + align:start position:0% +use numerical +methods so what I'm picturing here on + + align:start position:0% +methods so what I'm picturing here on + + + align:start position:0% +methods so what I'm picturing here on +slide number 14 is a very schematic + + align:start position:0% +slide number 14 is a very schematic + + + align:start position:0% +slide number 14 is a very schematic +picture of uh atoms moving around + + align:start position:0% +picture of uh atoms moving around + + + align:start position:0% +picture of uh atoms moving around +between planes in a lattice and so uh + + align:start position:0% +between planes in a lattice and so uh + + + align:start position:0% +between planes in a lattice and so uh +let's use this picture to get some + + align:start position:0% +let's use this picture to get some + + + align:start position:0% +let's use this picture to get some +physical insight into the diffusion + + align:start position:0% +physical insight into the diffusion + + + align:start position:0% +physical insight into the diffusion +process so each plane here is sort of + + align:start position:0% +process so each plane here is sort of + + + align:start position:0% +process so each plane here is sort of +indicated by a vertical bar and 0 1 2 3 + + align:start position:0% +indicated by a vertical bar and 0 1 2 3 + + + align:start position:0% +indicated by a vertical bar and 0 1 2 3 +4 and the distance between these planes + + align:start position:0% +4 and the distance between these planes + + + align:start position:0% +4 and the distance between these planes +is given by the distance Delta X as + + align:start position:0% +is given by the distance Delta X as + + + align:start position:0% +is given by the distance Delta X as +units of + + align:start position:0% +units of + + + align:start position:0% +units of +length and uh in subi here so n0 N1 and + + align:start position:0% +length and uh in subi here so n0 N1 and + + + align:start position:0% +length and uh in subi here so n0 N1 and +two is the planer Atomic density uh of + + align:start position:0% +two is the planer Atomic density uh of + + + align:start position:0% +two is the planer Atomic density uh of +the I plant so it's the number of atoms + + align:start position:0% +the I plant so it's the number of atoms + + + align:start position:0% +the I plant so it's the number of atoms +per square centimeter um in in a given + + align:start position:0% +per square centimeter um in in a given + + + align:start position:0% +per square centimeter um in in a given +plane and um + + align:start position:0% +plane and um + + + align:start position:0% +plane and um +cabi uh has volume concentration you + + align:start position:0% +cabi uh has volume concentration you + + + align:start position:0% +cabi uh has volume concentration you +it's it's the average volume + + align:start position:0% +it's it's the average volume + + + align:start position:0% +it's it's the average volume +concentration at any point so you can + + align:start position:0% +concentration at any point so you can + + + align:start position:0% +concentration at any point so you can +calculate you can get between the two c + + align:start position:0% +calculate you can get between the two c + + + align:start position:0% +calculate you can get between the two c +is just n subi over Delta X or n subi is + + align:start position:0% +is just n subi over Delta X or n subi is + + + align:start position:0% +is just n subi over Delta X or n subi is +just C subi * Delta + + align:start position:0% +just C subi * Delta + + + align:start position:0% +just C subi * Delta +X okay so let's go on to slide 15 or at + + align:start position:0% +X okay so let's go on to slide 15 or at + + + align:start position:0% +X okay so let's go on to slide 15 or at +the top I just reproduced that picture + + align:start position:0% +the top I just reproduced that picture + + + align:start position:0% +the top I just reproduced that picture +soly smaller version of it um and just + + align:start position:0% +soly smaller version of it um and just + + + align:start position:0% +soly smaller version of it um and just +reminding ourselves the the relationship + + align:start position:0% +reminding ourselves the the relationship + + + align:start position:0% +reminding ourselves the the relationship +between CI and + + align:start position:0% +between CI and + + + align:start position:0% +between CI and +ni now as we're looking at this lattice + + align:start position:0% +ni now as we're looking at this lattice + + + align:start position:0% +ni now as we're looking at this lattice +we know that the atoms are relatively + + align:start position:0% +we know that the atoms are relatively + + + align:start position:0% +we know that the atoms are relatively +fixed in the lattice but they do vibrate + + align:start position:0% +fixed in the lattice but they do vibrate + + + align:start position:0% +fixed in the lattice but they do vibrate +about their average position in a plane + + align:start position:0% +about their average position in a plane + + + align:start position:0% +about their average position in a plane +where average position and they're + + align:start position:0% +where average position and they're + + + align:start position:0% +where average position and they're +vibrating at some frequency V subd which + + align:start position:0% +vibrating at some frequency V subd which + + + align:start position:0% +vibrating at some frequency V subd which +is called the uh Debby frequency and + + align:start position:0% +is called the uh Debby frequency and + + + align:start position:0% +is called the uh Debby frequency and +that's that + + align:start position:0% +that's that + + + align:start position:0% +that's that +number is typically on the a of about 10 + + align:start position:0% +number is typically on the a of about 10 + + + align:start position:0% +number is typically on the a of about 10 +to 13th uh per second so it's pretty + + align:start position:0% +to 13th uh per second so it's pretty + + + align:start position:0% +to 13th uh per second so it's pretty +high frequency they're vibrating about + + align:start position:0% +high frequency they're vibrating about + + + align:start position:0% +high frequency they're vibrating about +their average blatus positions at a + + align:start position:0% +their average blatus positions at a + + + align:start position:0% +their average blatus positions at a +finite + + align:start position:0% +finite + + + align:start position:0% +finite +temperature uh now sometimes in during + + align:start position:0% +temperature uh now sometimes in during + + + align:start position:0% +temperature uh now sometimes in during +this vibration an atom will actually be + + align:start position:0% +this vibration an atom will actually be + + + align:start position:0% +this vibration an atom will actually be +able to surmount the energy barrier uh + + align:start position:0% +able to surmount the energy barrier uh + + + align:start position:0% +able to surmount the energy barrier uh +that exists in going from one last + + align:start position:0% +that exists in going from one last + + + align:start position:0% +that exists in going from one last +position to the next or one plane to the + + align:start position:0% +position to the next or one plane to the + + + align:start position:0% +position to the next or one plane to the +next so and it will actually be able to + + align:start position:0% +next so and it will actually be able to + + + align:start position:0% +next so and it will actually be able to +hop to an adjacent plane and there's an + + align:start position:0% +hop to an adjacent plane and there's an + + + align:start position:0% +hop to an adjacent plane and there's an +energy barrier which we'll call an Isa B + + align:start position:0% +energy barrier which we'll call an Isa B + + + align:start position:0% +energy barrier which we'll call an Isa B +uh to get from one plane to the + + align:start position:0% +uh to get from one plane to the + + + align:start position:0% +uh to get from one plane to the +next and uh this hopping frequency we + + align:start position:0% +next and uh this hopping frequency we + + + align:start position:0% +next and uh this hopping frequency we +call um + + align:start position:0% +call um + + + align:start position:0% +call um +BNB uh which is just a duy frequency VD + + align:start position:0% +BNB uh which is just a duy frequency VD + + + align:start position:0% +BNB uh which is just a duy frequency VD +that's the vibration frequency times a + + align:start position:0% +that's the vibration frequency times a + + + align:start position:0% +that's the vibration frequency times a +boltman factor exponential the minus uh + + align:start position:0% +boltman factor exponential the minus uh + + + align:start position:0% +boltman factor exponential the minus uh +e that's the energy barrier over + + align:start position:0% +e that's the energy barrier over + + + align:start position:0% +e that's the energy barrier over +KT so this V subb small V subb gives us + + align:start position:0% +KT so this V subb small V subb gives us + + + align:start position:0% +KT so this V subb small V subb gives us +an idea of the frequency of hopping from + + align:start position:0% +an idea of the frequency of hopping from + + + align:start position:0% +an idea of the frequency of hopping from +atoms from one plane to the next and + + align:start position:0% +atoms from one plane to the next and + + + align:start position:0% +atoms from one plane to the next and +what we assume in this derivation is + + align:start position:0% +what we assume in this derivation is + + + align:start position:0% +what we assume in this derivation is +that there's equal probability of + + align:start position:0% +that there's equal probability of + + + align:start position:0% +that there's equal probability of +jumping right or left because this is a + + align:start position:0% +jumping right or left because this is a + + + align:start position:0% +jumping right or left because this is a +random process um so if we look at any + + align:start position:0% +random process um so if we look at any + + + align:start position:0% +random process um so if we look at any +given plane we can say um the number of + + align:start position:0% +given plane we can say um the number of + + + align:start position:0% +given plane we can say um the number of +atoms jumping to the right of that plane + + align:start position:0% +atoms jumping to the right of that plane + + + align:start position:0% +atoms jumping to the right of that plane +per unit time is just VB over two times + + align:start position:0% +per unit time is just VB over two times + + + align:start position:0% +per unit time is just VB over two times +the number of atoms in that plane and + + align:start position:0% +the number of atoms in that plane and + + + align:start position:0% +the number of atoms in that plane and +half going go right number jumping left + + align:start position:0% +half going go right number jumping left + + + align:start position:0% +half going go right number jumping left +per unit time is just BB over two times + + align:start position:0% +per unit time is just BB over two times + + + align:start position:0% +per unit time is just BB over two times +the number in PL n so those two are + + align:start position:0% +the number in PL n so those two are + + + align:start position:0% +the number in PL n so those two are +equal um now if we do the bookkeeping + + align:start position:0% +equal um now if we do the bookkeeping + + + align:start position:0% +equal um now if we do the bookkeeping +and say look at the number of atoms + + align:start position:0% +and say look at the number of atoms + + + align:start position:0% +and say look at the number of atoms +crossing a plane uh the particular plane + + align:start position:0% +crossing a plane uh the particular plane + + + align:start position:0% +crossing a plane uh the particular plane +at I equals 2 in the above diagram so + + align:start position:0% +at I equals 2 in the above diagram so + + + align:start position:0% +at I equals 2 in the above diagram so +the plane labeled two uh number of atoms + + align:start position:0% +the plane labeled two uh number of atoms + + + align:start position:0% +the plane labeled two uh number of atoms +Crossing that plane per unit time well + + align:start position:0% +Crossing that plane per unit time well + + + align:start position:0% +Crossing that plane per unit time well +we can just uh write that as a + + align:start position:0% +we can just uh write that as a + + + align:start position:0% +we can just uh write that as a +flux and F an equation the bottom well + + align:start position:0% +flux and F an equation the bottom well + + + align:start position:0% +flux and F an equation the bottom well +that's just going to be uh the number of + + align:start position:0% +that's just going to be uh the number of + + + align:start position:0% +that's just going to be uh the number of +atoms um basically per unit time uh + + align:start position:0% +atoms um basically per unit time uh + + + align:start position:0% +atoms um basically per unit time uh +jumping to the right minus those uh + + align:start position:0% +jumping to the right minus those uh + + + align:start position:0% +jumping to the right minus those uh +jumping to the left uh so you write that + + align:start position:0% +jumping to the left uh so you write that + + + align:start position:0% +jumping to the left uh so you write that +as V minus VB over 2 N2 minus + + align:start position:0% +as V minus VB over 2 N2 minus + + + align:start position:0% +as V minus VB over 2 N2 minus +N1 again assuming equal probability + + align:start position:0% +N1 again assuming equal probability + + + align:start position:0% +N1 again assuming equal probability +going uh either way um so uh and then + + align:start position:0% +going uh either way um so uh and then + + + align:start position:0% +going uh either way um so uh and then +you can convert that the difference + + align:start position:0% +you can convert that the difference + + + align:start position:0% +you can convert that the difference +between uh Atomic uh density and uh + + align:start position:0% +between uh Atomic uh density and uh + + + align:start position:0% +between uh Atomic uh density and uh +numbered adoms per cubic centimeter just + + align:start position:0% +numbered adoms per cubic centimeter just + + + align:start position:0% +numbered adoms per cubic centimeter just +by multiplying using the definition of n + + align:start position:0% +by multiplying using the definition of n + + + align:start position:0% +by multiplying using the definition of n +is equal to Delta x * + + align:start position:0% +is equal to Delta x * + + + align:start position:0% +is equal to Delta x * +concentration you have then expression + + align:start position:0% +concentration you have then expression + + + align:start position:0% +concentration you have then expression +for this + + align:start position:0% +for this + + + align:start position:0% +for this +flux um Crossing plane IAL + + align:start position:0% +flux um Crossing plane IAL + + + align:start position:0% +flux um Crossing plane IAL +2 and then you multiply and divide by + + align:start position:0% +2 and then you multiply and divide by + + + align:start position:0% +2 and then you multiply and divide by +Delta X and you end up with this + + align:start position:0% +Delta X and you end up with this + + + align:start position:0% +Delta X and you end up with this +equation that this flux is equal to + + align:start position:0% +equation that this flux is equal to + + + align:start position:0% +equation that this flux is equal to +looking the right hand side minus bb/ 2 + + align:start position:0% +looking the right hand side minus bb/ 2 + + + align:start position:0% +looking the right hand side minus bb/ 2 +Delta x^2 times the the uh Delta C over + + align:start position:0% +Delta x^2 times the the uh Delta C over + + + align:start position:0% +Delta x^2 times the the uh Delta C over +Delta X something that's starting to + + align:start position:0% +Delta X something that's starting to + + + align:start position:0% +Delta X something that's starting to +look like uh a slope so we immediately + + align:start position:0% +look like uh a slope so we immediately + + + align:start position:0% +look like uh a slope so we immediately +see some kind of fix law fix law here + + align:start position:0% +see some kind of fix law fix law here + + + align:start position:0% +see some kind of fix law fix law here +where a flux is related to a slope times + + align:start position:0% +where a flux is related to a slope times + + + align:start position:0% +where a flux is related to a slope times +something out in front that that is a + + align:start position:0% +something out in front that that is a + + + align:start position:0% +something out in front that that is a +constant so that's at the bottom of + + align:start position:0% +constant so that's at the bottom of + + + align:start position:0% +constant so that's at the bottom of +slide 15 let's go on to slide 16 and + + align:start position:0% +slide 15 let's go on to slide 16 and + + + align:start position:0% +slide 15 let's go on to slide 16 and +I've just repeated that equation that we + + align:start position:0% +I've just repeated that equation that we + + + align:start position:0% +I've just repeated that equation that we +just had but I added one more uh thing + + align:start position:0% +just had but I added one more uh thing + + + align:start position:0% +just had but I added one more uh thing +on the right uh one more equality and we + + align:start position:0% +on the right uh one more equality and we + + + align:start position:0% +on the right uh one more equality and we +set that flux equal to diffusivity a + + align:start position:0% +set that flux equal to diffusivity a + + + align:start position:0% +set that flux equal to diffusivity a +number D times the slope Delta C over + + align:start position:0% +number D times the slope Delta C over + + + align:start position:0% +number D times the slope Delta C over +Delta X where we Define the diusivity in + + align:start position:0% +Delta X where we Define the diusivity in + + + align:start position:0% +Delta X where we Define the diusivity in +this particular equation to be equal to + + align:start position:0% +this particular equation to be equal to + + + align:start position:0% +this particular equation to be equal to +uh the VB over 2 * Delta + + align:start position:0% +uh the VB over 2 * Delta + + + align:start position:0% +uh the VB over 2 * Delta +x^2 so there is fixed fixed first law + + align:start position:0% +x^2 so there is fixed fixed first law + + + align:start position:0% +x^2 so there is fixed fixed first law +the flux is equal to minus a diffusivity + + align:start position:0% +the flux is equal to minus a diffusivity + + + align:start position:0% +the flux is equal to minus a diffusivity +a constant number times Delta C over + + align:start position:0% +a constant number times Delta C over + + + align:start position:0% +a constant number times Delta C over +Delta X and the diffusivity has some + + align:start position:0% +Delta X and the diffusivity has some + + + align:start position:0% +Delta X and the diffusivity has some +atonic + + align:start position:0% +atonic + + + align:start position:0% +atonic +scale um mechanisms view to it in fact + + align:start position:0% +scale um mechanisms view to it in fact + + + align:start position:0% +scale um mechanisms view to it in fact +it's uh proportional to the jump + + align:start position:0% +it's uh proportional to the jump + + + align:start position:0% +it's uh proportional to the jump +frequency uh V subd uh and therefore + + align:start position:0% +frequency uh V subd uh and therefore + + + align:start position:0% +frequency uh V subd uh and therefore +proportional being related to the energy + + align:start position:0% +proportional being related to the energy + + + align:start position:0% +proportional being related to the energy +bar + + align:start position:0% +bar + + + align:start position:0% +bar +to hop between adjacent positions or + + align:start position:0% +to hop between adjacent positions or + + + align:start position:0% +to hop between adjacent positions or +adjacent clients uh so gives you some + + align:start position:0% +adjacent clients uh so gives you some + + + align:start position:0% +adjacent clients uh so gives you some +idea of what at the atomic scale what + + align:start position:0% +idea of what at the atomic scale what + + + align:start position:0% +idea of what at the atomic scale what +goes into to determining the diffusivity + + align:start position:0% +goes into to determining the diffusivity + + + align:start position:0% +goes into to determining the diffusivity +view okay in addition to giving us an + + align:start position:0% +view okay in addition to giving us an + + + align:start position:0% +view okay in addition to giving us an +atomic scale view we can actually use + + align:start position:0% +atomic scale view we can actually use + + + align:start position:0% +atomic scale view we can actually use +this type of formalism to go ahead and + + align:start position:0% +this type of formalism to go ahead and + + + align:start position:0% +this type of formalism to go ahead and +derive uh a numerical solution to uh fix + + align:start position:0% +derive uh a numerical solution to uh fix + + + align:start position:0% +derive uh a numerical solution to uh fix +equation so let's go on to to do that + + align:start position:0% +equation so let's go on to to do that + + + align:start position:0% +equation so let's go on to to do that +we'll go on to slide number 17 which um + + align:start position:0% +we'll go on to slide number 17 which um + + + align:start position:0% +we'll go on to slide number 17 which um +a slightly different sketch but the the + + align:start position:0% +a slightly different sketch but the the + + + align:start position:0% +a slightly different sketch but the the +exact same ideas of what we're going to + + align:start position:0% +exact same ideas of what we're going to + + + align:start position:0% +exact same ideas of what we're going to +be going through uh and what I'm showing + + align:start position:0% +be going through uh and what I'm showing + + + align:start position:0% +be going through uh and what I'm showing +uh on the left- hand side in the bottom + + align:start position:0% +uh on the left- hand side in the bottom + + + align:start position:0% +uh on the left- hand side in the bottom +is a plot of concentration as a function + + align:start position:0% +is a plot of concentration as a function + + + align:start position:0% +is a plot of concentration as a function +of X so distance and let's say has some + + align:start position:0% +of X so distance and let's say has some + + + align:start position:0% +of X so distance and let's say has some +shape this dark uh dark decreasing uh + + align:start position:0% +shape this dark uh dark decreasing uh + + + align:start position:0% +shape this dark uh dark decreasing uh +black line and it's decreasing uh from + + align:start position:0% +black line and it's decreasing uh from + + + align:start position:0% +black line and it's decreasing uh from +left to to right and what we're going to + + align:start position:0% +left to to right and what we're going to + + + align:start position:0% +left to to right and what we're going to +do is we're going to discretize this let + + align:start position:0% +do is we're going to discretize this let + + + align:start position:0% +do is we're going to discretize this let +me look at discrete uh positions in + + align:start position:0% +me look at discrete uh positions in + + + align:start position:0% +me look at discrete uh positions in +Space X and the concentration C 0 C1 and + + align:start position:0% +Space X and the concentration C 0 C1 and + + + align:start position:0% +Space X and the concentration C 0 C1 and +C2 and the spacing between those planes + + align:start position:0% +C2 and the spacing between those planes + + + align:start position:0% +C2 and the spacing between those planes +is going to be a constant just like we + + align:start position:0% +is going to be a constant just like we + + + align:start position:0% +is going to be a constant just like we +used before uh Delta + + align:start position:0% +used before uh Delta + + + align:start position:0% +used before uh Delta +X and so what we're going to look at uh + + align:start position:0% +X and so what we're going to look at uh + + + align:start position:0% +X and so what we're going to look at uh +is in the time interval delta T a + + align:start position:0% +is in the time interval delta T a + + + align:start position:0% +is in the time interval delta T a +certain time interval Delta 2 uh what is + + align:start position:0% +certain time interval Delta 2 uh what is + + + align:start position:0% +certain time interval Delta 2 uh what is +the number of atoms crossing a certain + + align:start position:0% +the number of atoms crossing a certain + + + align:start position:0% +the number of atoms crossing a certain +plane per unit area and we call that to + + align:start position:0% +plane per unit area and we call that to + + + align:start position:0% +plane per unit area and we call that to +the plane R which we had labeled R above + + align:start position:0% +the plane R which we had labeled R above + + + align:start position:0% +the plane R which we had labeled R above +Q subr it's just the flux F subr time + + align:start position:0% +Q subr it's just the flux F subr time + + + align:start position:0% +Q subr it's just the flux F subr time +delta T that's the number of atoms + + align:start position:0% +delta T that's the number of atoms + + + align:start position:0% +delta T that's the number of atoms +crossing the unit area in a given uh + + align:start position:0% +crossing the unit area in a given uh + + + align:start position:0% +crossing the unit area in a given uh +time interval that just basically is + + align:start position:0% +time interval that just basically is + + + align:start position:0% +time interval that just basically is +comes from the definition of what flux + + align:start position:0% +comes from the definition of what flux + + + align:start position:0% +comes from the definition of what flux +is and um we then can write in for the + + align:start position:0% +is and um we then can write in for the + + + align:start position:0% +is and um we then can write in for the +flux uh the flux is just the diffusivity + + align:start position:0% +flux uh the flux is just the diffusivity + + + align:start position:0% +flux uh the flux is just the diffusivity +of D times the concentration difference + + align:start position:0% +of D times the concentration difference + + + align:start position:0% +of D times the concentration difference +across that + + align:start position:0% +across that + + + align:start position:0% +across that +plane across plane R well the + + align:start position:0% +plane across plane R well the + + + align:start position:0% +plane across plane R well the +concentration difference across plane R + + align:start position:0% +concentration difference across plane R + + + align:start position:0% +concentration difference across plane R +is C1 minus C / Delta X so we can uh + + align:start position:0% +is C1 minus C / Delta X so we can uh + + + align:start position:0% +is C1 minus C / Delta X so we can uh +approximate that way the flux Crossing + + align:start position:0% +approximate that way the flux Crossing + + + align:start position:0% +approximate that way the flux Crossing +plane R what's the flux Crossing plane s + + align:start position:0% +plane R what's the flux Crossing plane s + + + align:start position:0% +plane R what's the flux Crossing plane s +well we do the exact same thing or the + + align:start position:0% +well we do the exact same thing or the + + + align:start position:0% +well we do the exact same thing or the +number of atoms Crossing plane s it's + + align:start position:0% +number of atoms Crossing plane s it's + + + align:start position:0% +number of atoms Crossing plane s it's +just the diffusivity times Delta P times + + align:start position:0% +just the diffusivity times Delta P times + + + align:start position:0% +just the diffusivity times Delta P times +this time we subtract C2 minus C1 over + + align:start position:0% +this time we subtract C2 minus C1 over + + + align:start position:0% +this time we subtract C2 minus C1 over +Delta + + align:start position:0% +Delta + + + align:start position:0% +Delta +X so we can then do some bookkeeping and + + align:start position:0% +X so we can then do some bookkeeping and + + + align:start position:0% +X so we can then do some bookkeeping and +calculate the knit number of atoms + + align:start position:0% +calculate the knit number of atoms + + + align:start position:0% +calculate the knit number of atoms +accumulated in that shaded region + + align:start position:0% +accumulated in that shaded region + + + align:start position:0% +accumulated in that shaded region +between plain R and plain s in the K in + + align:start position:0% +between plain R and plain s in the K in + + + align:start position:0% +between plain R and plain s in the K in +delta T it's just um uh QR minus Qs and + + align:start position:0% +delta T it's just um uh QR minus Qs and + + + align:start position:0% +delta T it's just um uh QR minus Qs and +we just subtract these two expressions + + align:start position:0% +we just subtract these two expressions + + + align:start position:0% +we just subtract these two expressions +and you see what you end up with is is + + align:start position:0% +and you see what you end up with is is + + + align:start position:0% +and you see what you end up with is is +equal to a + + align:start position:0% +equal to a + + + align:start position:0% +equal to a +diff time the time interval delta T + + align:start position:0% +diff time the time interval delta T + + + align:start position:0% +diff time the time interval delta T +times in parentheses the C - 2 C1 + C2 + + align:start position:0% +times in parentheses the C - 2 C1 + C2 + + + align:start position:0% +times in parentheses the C - 2 C1 + C2 +that whole same quantity over Delta + + align:start position:0% + + + + align:start position:0% + +X now if we divide that those that net + + align:start position:0% +X now if we divide that those that net + + + align:start position:0% +X now if we divide that those that net +gain in the number of atoms divided by + + align:start position:0% +gain in the number of atoms divided by + + + align:start position:0% +gain in the number of atoms divided by +Delta X is shown below that is the net + + align:start position:0% +Delta X is shown below that is the net + + + align:start position:0% +Delta X is shown below that is the net +gain in the concentration in that shaded + + align:start position:0% +gain in the concentration in that shaded + + + align:start position:0% +gain in the concentration in that shaded +region that's Delta C and that's just QR + + align:start position:0% +region that's Delta C and that's just QR + + + align:start position:0% +region that's Delta C and that's just QR +minus Qs that quantity divided by Delta + + align:start position:0% +minus Qs that quantity divided by Delta + + + align:start position:0% +minus Qs that quantity divided by Delta +x uh so I can uh substituting in QR + + align:start position:0% +x uh so I can uh substituting in QR + + + align:start position:0% +x uh so I can uh substituting in QR +minus Qs and you end up with the + + align:start position:0% +minus Qs and you end up with the + + + align:start position:0% +minus Qs and you end up with the +equation near the bottom which just says + + align:start position:0% +equation near the bottom which just says + + + align:start position:0% +equation near the bottom which just says +the net gain in the concentration Delta + + align:start position:0% +the net gain in the concentration Delta + + + align:start position:0% +the net gain in the concentration Delta +C in this shaded region is just + + align:start position:0% +C in this shaded region is just + + + align:start position:0% +C in this shaded region is just +diffusivity D time delta T times this + + align:start position:0% +diffusivity D time delta T times this + + + align:start position:0% +diffusivity D time delta T times this +quantity and parentheses which is + + align:start position:0% +quantity and parentheses which is + + + align:start position:0% +quantity and parentheses which is +related to the concentrations in those + + align:start position:0% +related to the concentrations in those + + + align:start position:0% +related to the concentrations in those +three regions divided by Delta + + align:start position:0% +three regions divided by Delta + + + align:start position:0% +three regions divided by Delta +x^2 so what it says is at a given point + + align:start position:0% +x^2 so what it says is at a given point + + + align:start position:0% +x^2 so what it says is at a given point +C1 in this Cur if I know the + + align:start position:0% +C1 in this Cur if I know the + + + align:start position:0% +C1 in this Cur if I know the +concentrations of the neighboring points + + align:start position:0% +concentrations of the neighboring points + + + align:start position:0% +concentrations of the neighboring points +so I know its neighbors I know the + + align:start position:0% +so I know its neighbors I know the + + + align:start position:0% +so I know its neighbors I know the +concentration at uh c0 and it's C2 you + + align:start position:0% +concentration at uh c0 and it's C2 you + + + align:start position:0% +concentration at uh c0 and it's C2 you +can calculate a new concentration after + + align:start position:0% +can calculate a new concentration after + + + align:start position:0% +can calculate a new concentration after +a certain time step delta T at C1 um + + align:start position:0% +a certain time step delta T at C1 um + + + align:start position:0% +a certain time step delta T at C1 um +just by knowing its neighbors um at this + + align:start position:0% +just by knowing its neighbors um at this + + + align:start position:0% +just by knowing its neighbors um at this +time step the concentration of its + + align:start position:0% +time step the concentration of its + + + align:start position:0% +time step the concentration of its +neighbors um so uh if we go on to slide + + align:start position:0% +neighbors um so uh if we go on to slide + + + align:start position:0% +neighbors um so uh if we go on to slide +number 18 we can then use that + + align:start position:0% +number 18 we can then use that + + + align:start position:0% +number 18 we can then use that +information to come up with something + + align:start position:0% +information to come up with something + + + align:start position:0% +information to come up with something +called an explicit finite difference + + align:start position:0% +called an explicit finite difference + + + align:start position:0% +called an explicit finite difference +formula that's what the equation being + + align:start position:0% +formula that's what the equation being + + + align:start position:0% +formula that's what the equation being +shown near the top of of the slide 18 uh + + align:start position:0% +shown near the top of of the slide 18 uh + + + align:start position:0% +shown near the top of of the slide 18 uh +what you're saying is that the + + align:start position:0% +what you're saying is that the + + + align:start position:0% +what you're saying is that the +concentration at any given point I in in + + align:start position:0% +concentration at any given point I in in + + + align:start position:0% +concentration at any given point I in in +one of these + + align:start position:0% +one of these + + + align:start position:0% +one of these +slabs at a new time t plus delta T so + + align:start position:0% +slabs at a new time t plus delta T so + + + align:start position:0% +slabs at a new time t plus delta T so +we're going to evolve this profile over + + align:start position:0% +we're going to evolve this profile over + + + align:start position:0% +we're going to evolve this profile over +time so C plus on the leftand + + align:start position:0% +time so C plus on the leftand + + + align:start position:0% +time so C plus on the leftand +side uh is equal to the concentration at + + align:start position:0% +side uh is equal to the concentration at + + + align:start position:0% +side uh is equal to the concentration at +time T so one interval below before that + + align:start position:0% +time T so one interval below before that + + + align:start position:0% +time T so one interval below before that +whatever it was before plus we add in + + align:start position:0% +whatever it was before plus we add in + + + align:start position:0% +whatever it was before plus we add in +this uh this difference this term on the + + align:start position:0% +this uh this difference this term on the + + + align:start position:0% +this uh this difference this term on the +right that gives a change in the + + align:start position:0% +right that gives a change in the + + + align:start position:0% +right that gives a change in the +concentration in the I slab after a Time + + align:start position:0% +concentration in the I slab after a Time + + + align:start position:0% +concentration in the I slab after a Time +step delta T and that term is just D the + + align:start position:0% +step delta T and that term is just D the + + + align:start position:0% +step delta T and that term is just D the +diffusivity delta T / Delta f^ 2times + + align:start position:0% +diffusivity delta T / Delta f^ 2times + + + align:start position:0% +diffusivity delta T / Delta f^ 2times +the quantity parentheses where again the + + align:start position:0% +the quantity parentheses where again the + + + align:start position:0% +the quantity parentheses where again the +quantity parentheses in order evaluated + + align:start position:0% +quantity parentheses in order evaluated + + + align:start position:0% +quantity parentheses in order evaluated +at any point C all I need to know is the + + align:start position:0% +at any point C all I need to know is the + + + align:start position:0% +at any point C all I need to know is the +concentration at that point and the + + align:start position:0% +concentration at that point and the + + + align:start position:0% +concentration at that point and the +concentration it's two nearest + + align:start position:0% +concentration it's two nearest + + + align:start position:0% +concentration it's two nearest +Neighbors in in whatever way that we've + + align:start position:0% +Neighbors in in whatever way that we've + + + align:start position:0% +Neighbors in in whatever way that we've +discretized we've discretized this + + align:start position:0% +discretized we've discretized this + + + align:start position:0% +discretized we've discretized this +continuous function into uh little + + align:start position:0% +continuous function into uh little + + + align:start position:0% +continuous function into uh little +intervals Delta + + align:start position:0% +intervals Delta + + + align:start position:0% +intervals Delta +X so that is a an explicit formula you + + align:start position:0% +X so that is a an explicit formula you + + + align:start position:0% +X so that is a an explicit formula you +can use to evolve a a concentration + + align:start position:0% +can use to evolve a a concentration + + + align:start position:0% +can use to evolve a a concentration +profile um in shape over time and if you + + align:start position:0% +profile um in shape over time and if you + + + align:start position:0% +profile um in shape over time and if you +look at it for a few minutes you can + + align:start position:0% +look at it for a few minutes you can + + + align:start position:0% +look at it for a few minutes you can +notice the similarity of that difference + + align:start position:0% +notice the similarity of that difference + + + align:start position:0% +notice the similarity of that difference +formula to the differential equation for + + align:start position:0% +formula to the differential equation for + + + align:start position:0% +formula to the differential equation for +diffusion which uh if you take the the + + align:start position:0% +diffusion which uh if you take the the + + + align:start position:0% +diffusion which uh if you take the the +partial uh partial G on this equation + + align:start position:0% +partial uh partial G on this equation + + + align:start position:0% +partial uh partial G on this equation +shown in the center and lo it over the + + align:start position:0% +shown in the center and lo it over the + + + align:start position:0% +shown in the center and lo it over the +right hand side you can see that partial + + align:start position:0% +right hand side you can see that partial + + + align:start position:0% +right hand side you can see that partial +C is equal to some constant D times a + + align:start position:0% +C is equal to some constant D times a + + + align:start position:0% +C is equal to some constant D times a +second derivative of concentration with + + align:start position:0% +second derivative of concentration with + + + align:start position:0% +second derivative of concentration with +respect to X and in fact this partial um + + align:start position:0% +respect to X and in fact this partial um + + + align:start position:0% +respect to X and in fact this partial um +second derivative of C with respect to X + + align:start position:0% +second derivative of C with respect to X + + + align:start position:0% +second derivative of C with respect to X +it can be numerically evaluated as the + + align:start position:0% +it can be numerically evaluated as the + + + align:start position:0% +it can be numerically evaluated as the +term in the first equation on on on + + align:start position:0% +term in the first equation on on on + + + align:start position:0% +term in the first equation on on on +slide 18 on the right hand side that is + + align:start position:0% +slide 18 on the right hand side that is + + + align:start position:0% +slide 18 on the right hand side that is +a numerical solution to that + + align:start position:0% +a numerical solution to that + + + align:start position:0% +a numerical solution to that +differential + + align:start position:0% +differential + + + align:start position:0% +differential +equation and um I won't derive it here + + align:start position:0% +equation and um I won't derive it here + + + align:start position:0% +equation and um I won't derive it here +if you go back to crank's book or any of + + align:start position:0% +if you go back to crank's book or any of + + + align:start position:0% +if you go back to crank's book or any of +the books on uh uh numerical methods and + + align:start position:0% +the books on uh uh numerical methods and + + + align:start position:0% +the books on uh uh numerical methods and +you find that uh the method is + + align:start position:0% +you find that uh the method is + + + align:start position:0% +you find that uh the method is +numerically stable so it works from a + + align:start position:0% +numerically stable so it works from a + + + align:start position:0% +numerically stable so it works from a +numerical point of view it gives + + align:start position:0% +numerical point of view it gives + + + align:start position:0% +numerical point of view it gives +reasonable + + align:start position:0% +reasonable + + + align:start position:0% +reasonable +answers for a particular condition we + + align:start position:0% +answers for a particular condition we + + + align:start position:0% +answers for a particular condition we +have when we're doing the solution we + + align:start position:0% +have when we're doing the solution we + + + align:start position:0% +have when we're doing the solution we +have a condition on a quantity R where + + align:start position:0% +have a condition on a quantity R where + + + align:start position:0% +have a condition on a quantity R where +this quantity R is is is what mult the + + align:start position:0% +this quantity R is is is what mult the + + + align:start position:0% +this quantity R is is is what mult the +plus uh the concentration change in a in + + align:start position:0% +plus uh the concentration change in a in + + + align:start position:0% +plus uh the concentration change in a in +in a slab at certain time step delta T + + align:start position:0% +in a slab at certain time step delta T + + + align:start position:0% +in a slab at certain time step delta T +that D delta T over Delta x^2 that + + align:start position:0% +that D delta T over Delta x^2 that + + + align:start position:0% +that D delta T over Delta x^2 that +multiplier has to be less than or equal + + align:start position:0% +multiplier has to be less than or equal + + + align:start position:0% +multiplier has to be less than or equal +to 1 12 if that multiplier gets too + + align:start position:0% +to 1 12 if that multiplier gets too + + + align:start position:0% +to 1 12 if that multiplier gets too +large the meth the whole method breaks + + align:start position:0% +large the meth the whole method breaks + + + align:start position:0% +large the meth the whole method breaks +down become unstable and you get + + align:start position:0% +down become unstable and you get + + + align:start position:0% +down become unstable and you get +nonsense Absolut um totally unmeaningful + + align:start position:0% +nonsense Absolut um totally unmeaningful + + + align:start position:0% +nonsense Absolut um totally unmeaningful +um Solutions so you need to keep need to + + align:start position:0% +um Solutions so you need to keep need to + + + align:start position:0% +um Solutions so you need to keep need to +adjust if you're doing this numerical + + align:start position:0% +adjust if you're doing this numerical + + + align:start position:0% +adjust if you're doing this numerical +make sure you adjust your time steps + + align:start position:0% +make sure you adjust your time steps + + + align:start position:0% +make sure you adjust your time steps +delta T to be small enough enough so + + align:start position:0% +delta T to be small enough enough so + + + align:start position:0% +delta T to be small enough enough so +that this + + align:start position:0% +that this + + + align:start position:0% +that this +holds um and uh your Delta X um to be be + + align:start position:0% +holds um and uh your Delta X um to be be + + + align:start position:0% +holds um and uh your Delta X um to be be +of appropriate size in delta T um so + + align:start position:0% +of appropriate size in delta T um so + + + align:start position:0% +of appropriate size in delta T um so +that you don't get yourself out of the + + align:start position:0% +that you don't get yourself out of the + + + align:start position:0% +that you don't get yourself out of the +um out of the + + align:start position:0% +um out of the + + + align:start position:0% +um out of the +physically um out of the numerically + + align:start position:0% +physically um out of the numerically + + + align:start position:0% +physically um out of the numerically +stable uh solution it's a very powerful + + align:start position:0% +stable uh solution it's a very powerful + + + align:start position:0% +stable uh solution it's a very powerful +technique it's very simple that's one of + + align:start position:0% +technique it's very simple that's one of + + + align:start position:0% +technique it's very simple that's one of +the nice things about it um and it's + + align:start position:0% +the nice things about it um and it's + + + align:start position:0% +the nice things about it um and it's +certainly going to be required to use + + align:start position:0% +certainly going to be required to use + + + align:start position:0% +certainly going to be required to use +some method numerical method uh when the + + align:start position:0% +some method numerical method uh when the + + + align:start position:0% +some method numerical method uh when the +diffusivity is not not a constant um + + align:start position:0% +diffusivity is not not a constant um + + + align:start position:0% +diffusivity is not not a constant um +um if you were to sit down you could + + align:start position:0% +um if you were to sit down you could + + + align:start position:0% +um if you were to sit down you could +write your own simple simulator using + + align:start position:0% +write your own simple simulator using + + + align:start position:0% +write your own simple simulator using +this very uh relatably uh easy to use a + + align:start position:0% +this very uh relatably uh easy to use a + + + align:start position:0% +this very uh relatably uh easy to use a +finite difference one um it is not the + + align:start position:0% +finite difference one um it is not the + + + align:start position:0% +finite difference one um it is not the +particular type of numerical method + + align:start position:0% +particular type of numerical method + + + align:start position:0% +particular type of numerical method +that's been that is being used in + + align:start position:0% +that's been that is being used in + + + align:start position:0% +that's been that is being used in +Supreme 4 Supreme 4 has a more + + align:start position:0% +Supreme 4 Supreme 4 has a more + + + align:start position:0% +Supreme 4 Supreme 4 has a more +sophisticated numerical solution method + + align:start position:0% +sophisticated numerical solution method + + + align:start position:0% +sophisticated numerical solution method +for diffusion equation um this is much + + align:start position:0% +for diffusion equation um this is much + + + align:start position:0% +for diffusion equation um this is much +more simplified this particular method + + align:start position:0% +more simplified this particular method + + + align:start position:0% +more simplified this particular method +it can be slow it has all of its own + + align:start position:0% +it can be slow it has all of its own + + + align:start position:0% +it can be slow it has all of its own +problems but the beauty of it is the + + align:start position:0% +problems but the beauty of it is the + + + align:start position:0% +problems but the beauty of it is the +Simplicity and just to give you an idea + + align:start position:0% +Simplicity and just to give you an idea + + + align:start position:0% +Simplicity and just to give you an idea +a of how one would would might use + + align:start position:0% +a of how one would would might use + + + align:start position:0% +a of how one would would might use +numerical Solutions uh to obtain num + + align:start position:0% +numerical Solutions uh to obtain num + + + align:start position:0% +numerical Solutions uh to obtain num +numerical methods to obtain Solutions of + + align:start position:0% +numerical methods to obtain Solutions of + + + align:start position:0% +numerical methods to obtain Solutions of +diffusion + + align:start position:0% +diffusion + + + align:start position:0% +diffusion +equos okay let's go on now to + + align:start position:0% +equos okay let's go on now to + + + align:start position:0% +equos okay let's go on now to +um uh slide number 19 what what I want + + align:start position:0% +um uh slide number 19 what what I want + + + align:start position:0% +um uh slide number 19 what what I want +to talk about at this point are from now + + align:start position:0% +to talk about at this point are from now + + + align:start position:0% +to talk about at this point are from now +on and this the rest of this lecture and + + align:start position:0% +on and this the rest of this lecture and + + + align:start position:0% +on and this the rest of this lecture and +the next couple of lectures will be the + + align:start position:0% +the next couple of lectures will be the + + + align:start position:0% +the next couple of lectures will be the +uh so-called mod modifications of pixel + + align:start position:0% +uh so-called mod modifications of pixel + + + align:start position:0% +uh so-called mod modifications of pixel +laws fix laws are introduced in a lot of + + align:start position:0% +laws fix laws are introduced in a lot of + + + align:start position:0% +laws fix laws are introduced in a lot of +basic courses um Material Science or or + + align:start position:0% +basic courses um Material Science or or + + + align:start position:0% +basic courses um Material Science or or +or physics um and uh when we are + + align:start position:0% +or physics um and uh when we are + + + align:start position:0% +or physics um and uh when we are +diffusing uh dolance in semiconductors + + align:start position:0% +diffusing uh dolance in semiconductors + + + align:start position:0% +diffusing uh dolance in semiconductors +in Practical + + align:start position:0% +in Practical + + + align:start position:0% +in Practical +cases there are a few a number of cases + + align:start position:0% +cases there are a few a number of cases + + + align:start position:0% +cases there are a few a number of cases +where uh fixed laws need to be modified + + align:start position:0% +where uh fixed laws need to be modified + + + align:start position:0% +where uh fixed laws need to be modified +to take into account uh the things that + + align:start position:0% +to take into account uh the things that + + + align:start position:0% +to take into account uh the things that +are really going on in semor processing + + align:start position:0% +are really going on in semor processing + + + align:start position:0% +are really going on in semor processing +and the first thing that we'll talk + + align:start position:0% +and the first thing that we'll talk + + + align:start position:0% +and the first thing that we'll talk +about here on slide 19 is so-called + + align:start position:0% +about here on slide 19 is so-called + + + align:start position:0% +about here on slide 19 is so-called +electric field effect + + align:start position:0% +electric field effect + + + align:start position:0% +electric field effect +and this occurs in the case when the + + align:start position:0% +and this occurs in the case when the + + + align:start position:0% +and this occurs in the case when the +doping + + align:start position:0% +doping + + + align:start position:0% +doping +concentration uh is uh is higher than + + align:start position:0% +concentration uh is uh is higher than + + + align:start position:0% +concentration uh is uh is higher than +insabi so uh insabi is intrinsic carrier + + align:start position:0% +insabi so uh insabi is intrinsic carrier + + + align:start position:0% +insabi so uh insabi is intrinsic carrier +concentration at a diffusion temperature + + align:start position:0% +concentration at a diffusion temperature + + + align:start position:0% +concentration at a diffusion temperature +again of a th inbi is close to mid10 to + + align:start position:0% +again of a th inbi is close to mid10 to + + + align:start position:0% +again of a th inbi is close to mid10 to +the 18th or so um if the doe + + align:start position:0% +the 18th or so um if the doe + + + align:start position:0% +the 18th or so um if the doe +concentration gets higher than that you + + align:start position:0% +concentration gets higher than that you + + + align:start position:0% +concentration gets higher than that you +can start to have um uh a + + align:start position:0% +can start to have um uh a + + + align:start position:0% +can start to have um uh a +non-uniformity in the um in the charge + + align:start position:0% +non-uniformity in the um in the charge + + + align:start position:0% +non-uniformity in the um in the charge +distribution in the semiconductor and + + align:start position:0% +distribution in the semiconductor and + + + align:start position:0% +distribution in the semiconductor and +electric field effects can become + + align:start position:0% +electric field effects can become + + + align:start position:0% +electric field effects can become +important and this is a a schematic + + align:start position:0% +important and this is a a schematic + + + align:start position:0% +important and this is a a schematic +demonstration of how electric Fields can + + align:start position:0% +demonstration of how electric Fields can + + + align:start position:0% +demonstration of how electric Fields can +arise when dope and are diffusing and + + align:start position:0% +arise when dope and are diffusing and + + + align:start position:0% +arise when dope and are diffusing and +silic and there's a plot of + + align:start position:0% +silic and there's a plot of + + + align:start position:0% +silic and there's a plot of +concentration schematically versus dep + + align:start position:0% +concentration schematically versus dep + + + align:start position:0% +concentration schematically versus dep +and the um the red uh the red line is + + align:start position:0% +and the um the red uh the red line is + + + align:start position:0% +and the um the red uh the red line is +supposed to represent the profile at any + + align:start position:0% +supposed to represent the profile at any + + + align:start position:0% +supposed to represent the profile at any +given point in time for say arsenic + + align:start position:0% +given point in time for say arsenic + + + align:start position:0% +given point in time for say arsenic +that's + + align:start position:0% +that's + + + align:start position:0% +that's +diffusing and arsenic is a donor if has + + align:start position:0% +diffusing and arsenic is a donor if has + + + align:start position:0% +diffusing and arsenic is a donor if has +one extra electron floating around it um + + align:start position:0% +one extra electron floating around it um + + + align:start position:0% +one extra electron floating around it um +and but the atom itself uh in the + + align:start position:0% +and but the atom itself uh in the + + + align:start position:0% +and but the atom itself uh in the +absence this electron this extra gance + + align:start position:0% +absence this electron this extra gance + + + align:start position:0% +absence this electron this extra gance +electron um is the donor itself is + + align:start position:0% +electron um is the donor itself is + + + align:start position:0% +electron um is the donor itself is +positively charged as an ion this arsic + + align:start position:0% +positively charged as an ion this arsic + + + align:start position:0% +positively charged as an ion this arsic +diffusing and uh there are the electrons + + align:start position:0% +diffusing and uh there are the electrons + + + align:start position:0% +diffusing and uh there are the electrons +um associated with this heavily dope + + align:start position:0% +um associated with this heavily dope + + + align:start position:0% +um associated with this heavily dope +Arion can diffuse ahead of the dopin and + + align:start position:0% +Arion can diffuse ahead of the dopin and + + + align:start position:0% +Arion can diffuse ahead of the dopin and +so this blue line is meant to represent + + align:start position:0% +so this blue line is meant to represent + + + align:start position:0% +so this blue line is meant to represent +the distribution or the diffusion + + align:start position:0% +the distribution or the diffusion + + + align:start position:0% +the distribution or the diffusion +profile of electrons let's + + align:start position:0% +profile of electrons let's + + + align:start position:0% +profile of electrons let's +say so the electrons uh diffuse and + + align:start position:0% +say so the electrons uh diffuse and + + + align:start position:0% +say so the electrons uh diffuse and +holes diffuse more rapidly than their + + align:start position:0% +holes diffuse more rapidly than their + + + align:start position:0% +holes diffuse more rapidly than their +Associated donors and + + align:start position:0% +Associated donors and + + + align:start position:0% +Associated donors and +acceptors because of that more rapid + + align:start position:0% +acceptors because of that more rapid + + + align:start position:0% +acceptors because of that more rapid +diffusion um they they'll diffuse sort + + align:start position:0% +diffusion um they they'll diffuse sort + + + align:start position:0% +diffusion um they they'll diffuse sort +the profile for electrons will be a + + align:start position:0% +the profile for electrons will be a + + + align:start position:0% +the profile for electrons will be a +little bit deeper diffuse s of ahead um + + align:start position:0% +little bit deeper diffuse s of ahead um + + + align:start position:0% +little bit deeper diffuse s of ahead um +being do that they're associated with + + align:start position:0% +being do that they're associated with + + + align:start position:0% +being do that they're associated with +until they reach some steady state + + align:start position:0% +until they reach some steady state + + + align:start position:0% +until they reach some steady state +condition where um the the drift flux uh + + align:start position:0% +condition where um the the drift flux uh + + + align:start position:0% +condition where um the the drift flux uh +from the internal electric field + + align:start position:0% +from the internal electric field + + + align:start position:0% +from the internal electric field +uh it's going to balance the diffusion + + align:start position:0% +uh it's going to balance the diffusion + + + align:start position:0% +uh it's going to balance the diffusion +uh the diffusion + + align:start position:0% +uh the diffusion + + + align:start position:0% +uh the diffusion +flux and and so what we look at here is + + align:start position:0% +flux and and so what we look at here is + + + align:start position:0% +flux and and so what we look at here is +there if you just look at this uh this + + align:start position:0% +there if you just look at this uh this + + + align:start position:0% +there if you just look at this uh this +schematic picture you'll see there is + + align:start position:0% +schematic picture you'll see there is + + + align:start position:0% +schematic picture you'll see there is +indeed from your Elementary um + + align:start position:0% +indeed from your Elementary um + + + align:start position:0% +indeed from your Elementary um +Electronics or solid state physics there + + align:start position:0% +Electronics or solid state physics there + + + align:start position:0% +Electronics or solid state physics there +is an electric field induced by this the + + align:start position:0% +is an electric field induced by this the + + + align:start position:0% +is an electric field induced by this the +fact that there's a net positive charge + + align:start position:0% +fact that there's a net positive charge + + + align:start position:0% +fact that there's a net positive charge +on the left region that is if you + + align:start position:0% +on the left region that is if you + + + align:start position:0% +on the left region that is if you +subtract all the Arsenic doners you + + align:start position:0% +subtract all the Arsenic doners you + + + align:start position:0% +subtract all the Arsenic doners you +subract the electron concentration there + + align:start position:0% +subract the electron concentration there + + + align:start position:0% +subract the electron concentration there +there's a net positive charge on the + + align:start position:0% +there's a net positive charge on the + + + align:start position:0% +there's a net positive charge on the +left there's a little bit of net + + align:start position:0% +left there's a little bit of net + + + align:start position:0% +left there's a little bit of net +negative charge on the right that + + align:start position:0% +negative charge on the right that + + + align:start position:0% +negative charge on the right that +produces an electric field pointing from + + align:start position:0% +produces an electric field pointing from + + + align:start position:0% +produces an electric field pointing from +left to right um so um that electric + + align:start position:0% +left to right um so um that electric + + + align:start position:0% +left to right um so um that electric +field then tends to cause electrons to + + align:start position:0% +field then tends to cause electrons to + + + align:start position:0% +field then tends to cause electrons to +drift from right to left right because + + align:start position:0% +drift from right to left right because + + + align:start position:0% +drift from right to left right because +they + + align:start position:0% +they + + + align:start position:0% +they +drift um against the field um so they're + + align:start position:0% +drift um against the field um so they're + + + align:start position:0% +drift um against the field um so they're +going to be drifting from right to left + + align:start position:0% +going to be drifting from right to left + + + align:start position:0% +going to be drifting from right to left +while they're diffusing from left to + + align:start position:0% +while they're diffusing from left to + + + align:start position:0% +while they're diffusing from left to +right because there's a concentration + + align:start position:0% +right because there's a concentration + + + align:start position:0% +right because there's a concentration +gradient so the electric field will + + align:start position:0% +gradient so the electric field will + + + align:start position:0% +gradient so the electric field will +build up to the point where there's + + align:start position:0% +build up to the point where there's + + + align:start position:0% +build up to the point where there's +steady state where that drift uh flux + + align:start position:0% +steady state where that drift uh flux + + + align:start position:0% +steady state where that drift uh flux +just balances the diffusion flux uh the + + align:start position:0% + + + + align:start position:0% + +electrons and again the physical orig + + align:start position:0% +electrons and again the physical orig + + + align:start position:0% +electrons and again the physical orig +this electric field is AFF that well + + align:start position:0% +this electric field is AFF that well + + + align:start position:0% +this electric field is AFF that well +electrons are are charged and holes and + + align:start position:0% +electrons are are charged and holes and + + + align:start position:0% +electrons are are charged and holes and +they have somewhat higher Mobility they + + align:start position:0% +they have somewhat higher Mobility they + + + align:start position:0% +they have somewhat higher Mobility they +can move around the wse much more + + align:start position:0% +can move around the wse much more + + + align:start position:0% +can move around the wse much more +readily than the dopen ions um + + align:start position:0% +readily than the dopen ions um + + + align:start position:0% +readily than the dopen ions um +themselves okay and again this is only + + align:start position:0% +themselves okay and again this is only + + + align:start position:0% +themselves okay and again this is only +going to happen in the particular case + + align:start position:0% +going to happen in the particular case + + + align:start position:0% +going to happen in the particular case +where the concentration of the doping is + + align:start position:0% +where the concentration of the doping is + + + align:start position:0% +where the concentration of the doping is +higher than in otherwise the uh the uh + + align:start position:0% +higher than in otherwise the uh the uh + + + align:start position:0% +higher than in otherwise the uh the uh +the background electron concentration is + + align:start position:0% +the background electron concentration is + + + align:start position:0% +the background electron concentration is +set by the temperature sure it's just a + + align:start position:0% +set by the temperature sure it's just a + + + align:start position:0% +set by the temperature sure it's just a +constant through uh throughout + + align:start position:0% +constant through uh throughout + + + align:start position:0% +constant through uh throughout +space so the electric field would not + + align:start position:0% +space so the electric field would not + + + align:start position:0% +space so the electric field would not +would not develop right at the edge of + + align:start position:0% +would not develop right at the edge of + + + align:start position:0% +would not develop right at the edge of +this diffusion + + align:start position:0% +this diffusion + + + align:start position:0% +this diffusion +profile let's go on to slide number 20 + + align:start position:0% +profile let's go on to slide number 20 + + + align:start position:0% +profile let's go on to slide number 20 +and so what we do is we modify pick's + + align:start position:0% +and so what we do is we modify pick's + + + align:start position:0% +and so what we do is we modify pick's +first law and we modify in a way that's + + align:start position:0% +first law and we modify in a way that's + + + align:start position:0% +first law and we modify in a way that's +that's very similar and and pretty much + + align:start position:0% +that's very similar and and pretty much + + + align:start position:0% +that's very similar and and pretty much +almost identical to what we do in our uh + + align:start position:0% +almost identical to what we do in our uh + + + align:start position:0% +almost identical to what we do in our uh +uh electronics or Sol State because + + align:start position:0% +uh electronics or Sol State because + + + align:start position:0% +uh electronics or Sol State because +classes we say that the total impurity + + align:start position:0% +classes we say that the total impurity + + + align:start position:0% +classes we say that the total impurity +atom flux and the presence of both a + + align:start position:0% +atom flux and the presence of both a + + + align:start position:0% +atom flux and the presence of both a +concentration gradient and an electric + + align:start position:0% +concentration gradient and an electric + + + align:start position:0% +concentration gradient and an electric +field can be written down as the sum of + + align:start position:0% +field can be written down as the sum of + + + align:start position:0% +field can be written down as the sum of +two fluxes one is f which is the normal + + align:start position:0% +two fluxes one is f which is the normal + + + align:start position:0% +two fluxes one is f which is the normal +fickin diffusion flux which is given by + + align:start position:0% +fickin diffusion flux which is given by + + + align:start position:0% +fickin diffusion flux which is given by +minus D partial C partial X Plus F Prime + + align:start position:0% +minus D partial C partial X Plus F Prime + + + align:start position:0% +minus D partial C partial X Plus F Prime +where F Prime is now the drift flux due + + align:start position:0% +where F Prime is now the drift flux due + + + align:start position:0% +where F Prime is now the drift flux due +to the electric field and for the drift + + align:start position:0% +to the electric field and for the drift + + + align:start position:0% +to the electric field and for the drift +flux I wrote down Z which is the the + + align:start position:0% +flux I wrote down Z which is the the + + + align:start position:0% +flux I wrote down Z which is the the +charge uh the charge number Z would be + + align:start position:0% +charge uh the charge number Z would be + + + align:start position:0% +charge uh the charge number Z would be +one uh you know for electron depends on + + align:start position:0% +one uh you know for electron depends on + + + align:start position:0% +one uh you know for electron depends on +the number of electronic charges + + align:start position:0% +the number of electronic charges + + + align:start position:0% +the number of electronic charges +associated with whatever is uh drifting + + align:start position:0% +associated with whatever is uh drifting + + + align:start position:0% +associated with whatever is uh drifting +times the mobility + + align:start position:0% +times the mobility + + + align:start position:0% +times the mobility +mu times the concentration c times the + + align:start position:0% +mu times the concentration c times the + + + align:start position:0% +mu times the concentration c times the +electric field that is uh the flux to + + align:start position:0% +electric field that is uh the flux to + + + align:start position:0% +electric field that is uh the flux to +the drift again that's not a diffusion + + align:start position:0% +the drift again that's not a diffusion + + + align:start position:0% +the drift again that's not a diffusion +process that's that's the drift process + + align:start position:0% +process that's that's the drift process + + + align:start position:0% +process that's that's the drift process +it's different physical process we going + + align:start position:0% +it's different physical process we going + + + align:start position:0% +it's different physical process we going +to add these two together now right then + + align:start position:0% +to add these two together now right then + + + align:start position:0% +to add these two together now right then +is the total flux so we have a non-fan + + align:start position:0% +is the total flux so we have a non-fan + + + align:start position:0% +is the total flux so we have a non-fan +term on the + + align:start position:0% +term on the + + + align:start position:0% +term on the +right um but because of the Einstein + + align:start position:0% +right um but because of the Einstein + + + align:start position:0% +right um but because of the Einstein +relation we can actually when we're + + align:start position:0% +relation we can actually when we're + + + align:start position:0% +relation we can actually when we're +talking about the diffusion of carriers + + align:start position:0% +talking about the diffusion of carriers + + + align:start position:0% +talking about the diffusion of carriers +like electrons and holes we know that + + align:start position:0% +like electrons and holes we know that + + + align:start position:0% +like electrons and holes we know that +their Mobility is directly proportional + + align:start position:0% +their Mobility is directly proportional + + + align:start position:0% +their Mobility is directly proportional +to the diffusivity and the + + align:start position:0% +to the diffusivity and the + + + align:start position:0% +to the diffusivity and the +proportionality constant is Q over KT so + + align:start position:0% +proportionality constant is Q over KT so + + + align:start position:0% +proportionality constant is Q over KT so +mu is equal to um D * Q over KT so I we + + align:start position:0% +mu is equal to um D * Q over KT so I we + + + align:start position:0% +mu is equal to um D * Q over KT so I we +can substitute in for the mobility in + + align:start position:0% +can substitute in for the mobility in + + + align:start position:0% +can substitute in for the mobility in +the upper right hand or equation with + + align:start position:0% +the upper right hand or equation with + + + align:start position:0% +the upper right hand or equation with +the substitute in uh Q over KT * + + align:start position:0% +the substitute in uh Q over KT * + + + align:start position:0% +the substitute in uh Q over KT * +D I can also substitute in the fact + + align:start position:0% +D I can also substitute in the fact + + + align:start position:0% +D I can also substitute in the fact +electric field e is degrading to the + + align:start position:0% +electric field e is degrading to the + + + align:start position:0% +electric field e is degrading to the +potential where the potential s uh can + + align:start position:0% +potential where the potential s uh can + + + align:start position:0% +potential where the potential s uh can +be related to the car concentration n uh + + align:start position:0% +be related to the car concentration n uh + + + align:start position:0% +be related to the car concentration n uh +as minus k T times the L of n over n + + align:start position:0% +as minus k T times the L of n over n + + + align:start position:0% +as minus k T times the L of n over n +i so basically by substituting in uh the + + align:start position:0% +i so basically by substituting in uh the + + + align:start position:0% +i so basically by substituting in uh the +expression proportional diffusivity for + + align:start position:0% +expression proportional diffusivity for + + + align:start position:0% +expression proportional diffusivity for +mu and substituting in for the electric + + align:start position:0% +mu and substituting in for the electric + + + align:start position:0% +mu and substituting in for the electric +field how it relates to the potential + + align:start position:0% +field how it relates to the potential + + + align:start position:0% +field how it relates to the potential +and therefore to n/ n i we get the + + align:start position:0% +and therefore to n/ n i we get the + + + align:start position:0% +and therefore to n/ n i we get the +equation um near the bottom for the flux + + align:start position:0% +equation um near the bottom for the flux + + + align:start position:0% +equation um near the bottom for the flux +F that's just the usual F minus D * + + align:start position:0% +F that's just the usual F minus D * + + + align:start position:0% +F that's just the usual F minus D * +partial C partial x * minus D time the + + align:start position:0% +partial C partial x * minus D time the + + + align:start position:0% +partial C partial x * minus D time the +concentration C time now we've come up + + align:start position:0% +concentration C time now we've come up + + + align:start position:0% +concentration C time now we've come up +with this um this s uh term partial + + align:start position:0% +with this um this s uh term partial + + + align:start position:0% +with this um this s uh term partial +partial x uh of me potential um then n + + align:start position:0% +partial x uh of me potential um then n + + + align:start position:0% +partial x uh of me potential um then n +Over + + align:start position:0% + + + + align:start position:0% + +N um so now this is a new um flux uh + + align:start position:0% +N um so now this is a new um flux uh + + + align:start position:0% +N um so now this is a new um flux uh +flux + + align:start position:0% +flux + + + align:start position:0% +flux +equation and um we can now we use for + + align:start position:0% +equation and um we can now we use for + + + align:start position:0% +equation and um we can now we use for +the car concentration n you have to be + + align:start position:0% +the car concentration n you have to be + + + align:start position:0% +the car concentration n you have to be +careful it's not just equal to ND + + align:start position:0% +careful it's not just equal to ND + + + align:start position:0% +careful it's not just equal to ND +because ni can be a order ND and so we + + align:start position:0% +because ni can be a order ND and so we + + + align:start position:0% +because ni can be a order ND and so we +need to make sure we use the full + + align:start position:0% +need to make sure we use the full + + + align:start position:0% +need to make sure we use the full +expression for the carer concentration + + align:start position:0% +expression for the carer concentration + + + align:start position:0% +expression for the carer concentration +and it's 1/2 this uh at the bottom + + align:start position:0% +and it's 1/2 this uh at the bottom + + + align:start position:0% +and it's 1/2 this uh at the bottom +equation here it's 1/2 times the + + align:start position:0% +equation here it's 1/2 times the + + + align:start position:0% +equation here it's 1/2 times the +quantity squ OT of nd2 + 4 n i s plus N + + align:start position:0% +quantity squ OT of nd2 + 4 n i s plus N + + + align:start position:0% +quantity squ OT of nd2 + 4 n i s plus N +D um that comes from charge + + align:start position:0% +D um that comes from charge + + + align:start position:0% +D um that comes from charge +neutrality um given that we there's + + align:start position:0% +neutrality um given that we there's + + + align:start position:0% +neutrality um given that we there's +there therefore there's a relationship + + align:start position:0% +there therefore there's a relationship + + + align:start position:0% +there therefore there's a relationship +between n the car concentration and um + + align:start position:0% +between n the car concentration and um + + + align:start position:0% +between n the car concentration and um +the concentration of the dopent C + + align:start position:0% +the concentration of the dopent C + + + align:start position:0% +the concentration of the dopent C +because again uh the the concentration C + + align:start position:0% +because again uh the the concentration C + + + align:start position:0% +because again uh the the concentration C +it's just NB minus + + align:start position:0% +it's just NB minus + + + align:start position:0% +it's just NB minus +na um so it's the net concentration so + + align:start position:0% +na um so it's the net concentration so + + + align:start position:0% +na um so it's the net concentration so +we have a relationship between n and C + + align:start position:0% +we have a relationship between n and C + + + align:start position:0% +we have a relationship between n and C +we use that to make this flux equation F + + align:start position:0% +we use that to make this flux equation F + + + align:start position:0% +we use that to make this flux equation F +to be written only in terms of the + + align:start position:0% +to be written only in terms of the + + + align:start position:0% +to be written only in terms of the +concentration C so with L of the next + + align:start position:0% +concentration C so with L of the next + + + align:start position:0% +concentration C so with L of the next +page slide + + align:start position:0% +page slide + + + align:start position:0% +page slide +21 what we find is that uh we can do + + align:start position:0% +21 what we find is that uh we can do + + + align:start position:0% +21 what we find is that uh we can do +this compression of this equation and we + + align:start position:0% +this compression of this equation and we + + + align:start position:0% +this compression of this equation and we +find that the total flux now f is + + align:start position:0% +find that the total flux now f is + + + align:start position:0% +find that the total flux now f is +written by as something called minus H * + + align:start position:0% +written by as something called minus H * + + + align:start position:0% +written by as something called minus H * +the diffusivity of a dop d sub a partial + + align:start position:0% +the diffusivity of a dop d sub a partial + + + align:start position:0% +the diffusivity of a dop d sub a partial +C partial X so we've been able to + + align:start position:0% +C partial X so we've been able to + + + align:start position:0% +C partial X so we've been able to +actually write down an equation looks + + align:start position:0% +actually write down an equation looks + + + align:start position:0% +actually write down an equation looks +just like um fixed first law but there's + + align:start position:0% +just like um fixed first law but there's + + + align:start position:0% +just like um fixed first law but there's +an h factor multiplying it and this h + + align:start position:0% +an h factor multiplying it and this h + + + align:start position:0% +an h factor multiplying it and this h +factor turns out to be equal to 1 plus + + align:start position:0% +factor turns out to be equal to 1 plus + + + align:start position:0% +factor turns out to be equal to 1 plus +uh C / the quantity squ of c^2 + 4 and + + align:start position:0% +uh C / the quantity squ of c^2 + 4 and + + + align:start position:0% +uh C / the quantity squ of c^2 + 4 and +i^ + + align:start position:0% +i^ + + + align:start position:0% +i^ + + align:start position:0% + + + align:start position:0% +um so basically uh it looks this in the + + align:start position:0% +um so basically uh it looks this in the + + + align:start position:0% +um so basically uh it looks this in the +in the presence of an electric field it + + align:start position:0% +in the presence of an electric field it + + + align:start position:0% +in the presence of an electric field it +looks just like we have an enhancement + + align:start position:0% +looks just like we have an enhancement + + + align:start position:0% +looks just like we have an enhancement +in the diusivity of the dopin by a + + align:start position:0% +in the diusivity of the dopin by a + + + align:start position:0% +in the diusivity of the dopin by a +factor called H you can you can we just + + align:start position:0% +factor called H you can you can we just + + + align:start position:0% +factor called H you can you can we just +work that out so uh interestingly we see + + align:start position:0% +work that out so uh interestingly we see + + + align:start position:0% +work that out so uh interestingly we see +that it electric field effect uh on a + + align:start position:0% +that it electric field effect uh on a + + + align:start position:0% +that it electric field effect uh on a +dopant that is creating the field on + + align:start position:0% +dopant that is creating the field on + + + align:start position:0% +dopant that is creating the field on +that buin itself it enhances theity and + + align:start position:0% +that buin itself it enhances theity and + + + align:start position:0% +that buin itself it enhances theity and +it turns out H has an upper bound of + + align:start position:0% +it turns out H has an upper bound of + + + align:start position:0% +it turns out H has an upper bound of +two so H is not going to be any larger + + align:start position:0% +two so H is not going to be any larger + + + align:start position:0% +two so H is not going to be any larger +than two and that means that the + + align:start position:0% +than two and that means that the + + + align:start position:0% +than two and that means that the +electric field enhancement term can + + align:start position:0% +electric field enhancement term can + + + align:start position:0% +electric field enhancement term can +enhance the diffusivity the doping that + + align:start position:0% +enhance the diffusivity the doping that + + + align:start position:0% +enhance the diffusivity the doping that +causes the field by as much as or a + + align:start position:0% +causes the field by as much as or a + + + align:start position:0% +causes the field by as much as or a +maximum Lim factor of + + align:start position:0% +maximum Lim factor of + + + align:start position:0% +maximum Lim factor of +two and this happens when the doping + + align:start position:0% +two and this happens when the doping + + + align:start position:0% +two and this happens when the doping +concentration term uh or C is much much + + align:start position:0% +concentration term uh or C is much much + + + align:start position:0% +concentration term uh or C is much much +greater than uh ni and you can see that + + align:start position:0% +greater than uh ni and you can see that + + + align:start position:0% +greater than uh ni and you can see that +by substituting in um and calculating + + align:start position:0% +by substituting in um and calculating + + + align:start position:0% +by substituting in um and calculating +out what H is in certain + + align:start position:0% +out what H is in certain + + + align:start position:0% +out what H is in certain +conditions uh when in the special case + + align:start position:0% +conditions uh when in the special case + + + align:start position:0% +conditions uh when in the special case +where um you know C is NI then uh H goes + + align:start position:0% +where um you know C is NI then uh H goes + + + align:start position:0% +where um you know C is NI then uh H goes +back to being + + align:start position:0% +back to being + + + align:start position:0% +back to being +to so uh how do we get to this equation + + align:start position:0% +to so uh how do we get to this equation + + + align:start position:0% +to so uh how do we get to this equation +where the simplified age Factor well if + + align:start position:0% +where the simplified age Factor well if + + + align:start position:0% +where the simplified age Factor well if +you go on uh onto slide number 22 + + align:start position:0% +you go on uh onto slide number 22 + + + align:start position:0% +you go on uh onto slide number 22 +actually I'm not going to go through all + + align:start position:0% +actually I'm not going to go through all + + + align:start position:0% +actually I'm not going to go through all +the algebra but basically uh what we did + + align:start position:0% +the algebra but basically uh what we did + + + align:start position:0% +the algebra but basically uh what we did +was we um used a particular fact which + + align:start position:0% +was we um used a particular fact which + + + align:start position:0% +was we um used a particular fact which +is that on the top of slide 22 partial + + align:start position:0% +is that on the top of slide 22 partial + + + align:start position:0% +is that on the top of slide 22 partial +partial X on the logarithm of X is equal + + align:start position:0% +partial X on the logarithm of X is equal + + + align:start position:0% +partial X on the logarithm of X is equal +to 1 /x and uh uh what we needed to find + + align:start position:0% +to 1 /x and uh uh what we needed to find + + + align:start position:0% +to 1 /x and uh uh what we needed to find +in that earlier defusion um and that + + align:start position:0% +in that earlier defusion um and that + + + align:start position:0% +in that earlier defusion um and that +earlier drift term there was a term that + + align:start position:0% +earlier drift term there was a term that + + + align:start position:0% +earlier drift term there was a term that +went partial partial X + + align:start position:0% +went partial partial X + + + align:start position:0% +went partial partial X +when um of hando the + + align:start position:0% +when um of hando the + + + align:start position:0% +when um of hando the +n and so just by going to the algebra + + align:start position:0% +n and so just by going to the algebra + + + align:start position:0% +n and so just by going to the algebra +shown on on uh we can substit on slide + + align:start position:0% +shown on on uh we can substit on slide + + + align:start position:0% +shown on on uh we can substit on slide +22 we can substitute for the car + + align:start position:0% +22 we can substitute for the car + + + align:start position:0% +22 we can substitute for the car +concentration n and we can find uh an + + align:start position:0% +concentration n and we can find uh an + + + align:start position:0% +concentration n and we can find uh an +expression for partial partial X of Len + + align:start position:0% +expression for partial partial X of Len + + + align:start position:0% +expression for partial partial X of Len +of n over n i and you see that in the + + align:start position:0% +of n over n i and you see that in the + + + align:start position:0% +of n over n i and you see that in the +middle of the of the slide and then we + + align:start position:0% +middle of the of the slide and then we + + + align:start position:0% +middle of the of the slide and then we +substitute in the dopin concentration in + + align:start position:0% +substitute in the dopin concentration in + + + align:start position:0% +substitute in the dopin concentration in +D is equal to C and we're able to see + + align:start position:0% +D is equal to C and we're able to see + + + align:start position:0% +D is equal to C and we're able to see +that the flux the total flux is the + + align:start position:0% +that the flux the total flux is the + + + align:start position:0% +that the flux the total flux is the +usual fickian term D minus D * partial C + + align:start position:0% +usual fickian term D minus D * partial C + + + align:start position:0% +usual fickian term D minus D * partial C +partial x minus this other term which + + align:start position:0% +partial x minus this other term which + + + align:start position:0% +partial x minus this other term which +ends up being able to be written um just + + align:start position:0% +ends up being able to be written um just + + + align:start position:0% +ends up being able to be written um just +like partial C partial X in terms of + + align:start position:0% +like partial C partial X in terms of + + + align:start position:0% +like partial C partial X in terms of +partial C partial x times the h + + align:start position:0% +partial C partial x times the h + + + align:start position:0% +partial C partial x times the h +factor where H was uh is equal to as it + + align:start position:0% +factor where H was uh is equal to as it + + + align:start position:0% +factor where H was uh is equal to as it +sh on the bottom 1 plus C over the + + align:start position:0% +sh on the bottom 1 plus C over the + + + align:start position:0% +sh on the bottom 1 plus C over the +square c^2 + 4 and I S so that's just + + align:start position:0% +square c^2 + 4 and I S so that's just + + + align:start position:0% +square c^2 + 4 and I S so that's just +justifies the derivation of each factor + + align:start position:0% +justifies the derivation of each factor + + + align:start position:0% +justifies the derivation of each factor +uh on slide 22 + + align:start position:0% +uh on slide 22 + + + align:start position:0% +uh on slide 22 +okay so just go back to SL 21 for one + + align:start position:0% +okay so just go back to SL 21 for one + + + align:start position:0% +okay so just go back to SL 21 for one +second and just want to remind ourselves + + align:start position:0% +second and just want to remind ourselves + + + align:start position:0% +second and just want to remind ourselves +that the uh total flux F now in the + + align:start position:0% +that the uh total flux F now in the + + + align:start position:0% +that the uh total flux F now in the +presence of a High car concentration can + + align:start position:0% +presence of a High car concentration can + + + align:start position:0% +presence of a High car concentration can +be written just like the fing diffusion + + align:start position:0% +be written just like the fing diffusion + + + align:start position:0% +be written just like the fing diffusion +but the H there's a multiplier H from + + align:start position:0% +but the H there's a multiplier H from + + + align:start position:0% +but the H there's a multiplier H from +the bity of the Dober atom + + align:start position:0% +the bity of the Dober atom + + + align:start position:0% +the bity of the Dober atom +a let's skip on to slide 23 now uh + + align:start position:0% +a let's skip on to slide 23 now uh + + + align:start position:0% +a let's skip on to slide 23 now uh +however so that's when we're talking + + align:start position:0% +however so that's when we're talking + + + align:start position:0% +however so that's when we're talking +about um the amount of enhancement you + + align:start position:0% +about um the amount of enhancement you + + + align:start position:0% +about um the amount of enhancement you +might get in the high concentration + + align:start position:0% +might get in the high concentration + + + align:start position:0% +might get in the high concentration +species + + align:start position:0% +species + + + align:start position:0% +species +um but you may have two different + + align:start position:0% +um but you may have two different + + + align:start position:0% +um but you may have two different +species diffusing and in the case where + + align:start position:0% +species diffusing and in the case where + + + align:start position:0% +species diffusing and in the case where +the species are at different + + align:start position:0% +the species are at different + + + align:start position:0% +the species are at different +concentrations the electric field term + + align:start position:0% +concentrations the electric field term + + + align:start position:0% +concentrations the electric field term +can actually cause an even larger change + + align:start position:0% +can actually cause an even larger change + + + align:start position:0% +can actually cause an even larger change +in the diffusivity of the low + + align:start position:0% +in the diffusivity of the low + + + align:start position:0% +in the diffusivity of the low +concentration building so let's look at + + align:start position:0% +concentration building so let's look at + + + align:start position:0% +concentration building so let's look at +a particular example uh shown on slide + + align:start position:0% +a particular example uh shown on slide + + + align:start position:0% +a particular example uh shown on slide +23 and uh what we're we're showing here + + align:start position:0% +23 and uh what we're we're showing here + + + align:start position:0% +23 and uh what we're we're showing here +is concentration is a function of depth + + align:start position:0% +is concentration is a function of depth + + + align:start position:0% +is concentration is a function of depth +and the red curve in high concentration + + align:start position:0% +and the red curve in high concentration + + + align:start position:0% +and the red curve in high concentration +let's say a high concentration arsenic + + align:start position:0% +let's say a high concentration arsenic + + + align:start position:0% +let's say a high concentration arsenic +profile um the initial arsenic profile + + align:start position:0% +profile um the initial arsenic profile + + + align:start position:0% +profile um the initial arsenic profile +looks it was I a plet or something it + + align:start position:0% +looks it was I a plet or something it + + + align:start position:0% +looks it was I a plet or something it +looks like this as shown in the solid + + align:start position:0% +looks like this as shown in the solid + + + align:start position:0% +looks like this as shown in the solid +red curve um the background building is + + align:start position:0% +red curve um the background building is + + + align:start position:0% +red curve um the background building is +initially all constant it's p typ so + + align:start position:0% +initially all constant it's p typ so + + + align:start position:0% +initially all constant it's p typ so +this is boron is shown by the solid um + + align:start position:0% +this is boron is shown by the solid um + + + align:start position:0% +this is boron is shown by the solid um +blue + + align:start position:0% +blue + + + align:start position:0% +blue +line now we're going to simulate uh + + align:start position:0% +line now we're going to simulate uh + + + align:start position:0% +line now we're going to simulate uh +including electric field effects at a + + align:start position:0% +including electric field effects at a + + + align:start position:0% +including electric field effects at a +th000 degrees the diffusion of the arsic + + align:start position:0% +th000 degrees the diffusion of the arsic + + + align:start position:0% +th000 degrees the diffusion of the arsic +and the + + align:start position:0% +and the + + + align:start position:0% +and the +Boron U well it turns out the Arsenic + + align:start position:0% +Boron U well it turns out the Arsenic + + + align:start position:0% +Boron U well it turns out the Arsenic +does in diffuse as shown by the dash + + align:start position:0% +does in diffuse as shown by the dash + + + align:start position:0% +does in diffuse as shown by the dash +line but that the electric field that it + + align:start position:0% +line but that the electric field that it + + + align:start position:0% +line but that the electric field that it +produces right near its um the slope + + align:start position:0% +produces right near its um the slope + + + align:start position:0% +produces right near its um the slope +right near the edge of its profile + + align:start position:0% +right near the edge of its profile + + + align:start position:0% +right near the edge of its profile +actually that electric field can cause a + + align:start position:0% +actually that electric field can cause a + + + align:start position:0% +actually that electric field can cause a +flux of of boron ions ions which can + + align:start position:0% +flux of of boron ions ions which can + + + align:start position:0% +flux of of boron ions ions which can +cause the Bon to uh itself to move so + + align:start position:0% +cause the Bon to uh itself to move so + + + align:start position:0% +cause the Bon to uh itself to move so +the final Boron profile uh now is is + + align:start position:0% +the final Boron profile uh now is is + + + align:start position:0% +the final Boron profile uh now is is +shown by the blue dash line has this + + align:start position:0% +shown by the blue dash line has this + + + align:start position:0% +shown by the blue dash line has this +little um hump in it and then a dip and + + align:start position:0% +little um hump in it and then a dip and + + + align:start position:0% +little um hump in it and then a dip and +that that little dip occurs right near + + align:start position:0% +that that little dip occurs right near + + + align:start position:0% +that that little dip occurs right near +where the the junction is right where is + + align:start position:0% +where the the junction is right where is + + + align:start position:0% +where the the junction is right where is +a blonde the arch and the blonde cross + + align:start position:0% +a blonde the arch and the blonde cross + + + align:start position:0% +a blonde the arch and the blonde cross +and there's no way by ficking in + + align:start position:0% +and there's no way by ficking in + + + align:start position:0% +and there's no way by ficking in +diffusion he would ever predict that a + + align:start position:0% +diffusion he would ever predict that a + + + align:start position:0% +diffusion he would ever predict that a +constant profile of Bon would end up + + align:start position:0% +constant profile of Bon would end up + + + align:start position:0% +constant profile of Bon would end up +being looking the way it does uh in this + + align:start position:0% +being looking the way it does uh in this + + + align:start position:0% +being looking the way it does uh in this +particular plot again that's because of + + align:start position:0% +particular plot again that's because of + + + align:start position:0% +particular plot again that's because of +the second term the electric field term + + align:start position:0% +the second term the electric field term + + + align:start position:0% +the second term the electric field term +that non-fickian + + align:start position:0% +that non-fickian + + + align:start position:0% +that non-fickian +term so and when you want to think about + + align:start position:0% +term so and when you want to think about + + + align:start position:0% +term so and when you want to think about +that how that occurred look at the + + align:start position:0% +that how that occurred look at the + + + align:start position:0% +that how that occurred look at the +electric field Arrow drawn from left to + + align:start position:0% +electric field Arrow drawn from left to + + + align:start position:0% +electric field Arrow drawn from left to +right uh again drawing from positive net + + align:start position:0% +right uh again drawing from positive net + + + align:start position:0% +right uh again drawing from positive net +positive to net negative charge that + + align:start position:0% +positive to net negative charge that + + + align:start position:0% +positive to net negative charge that +direction of e pulls the the born again + + align:start position:0% +direction of e pulls the the born again + + + align:start position:0% +direction of e pulls the the born again +remember the born ions as they diffuse + + align:start position:0% +remember the born ions as they diffuse + + + align:start position:0% +remember the born ions as they diffuse +their B minus these acceptors andit + + align:start position:0% +their B minus these acceptors andit + + + align:start position:0% +their B minus these acceptors andit +negative charge so they're going to be + + align:start position:0% +negative charge so they're going to be + + + align:start position:0% +negative charge so they're going to be +pulled in they're going to move to the + + align:start position:0% +pulled in they're going to move to the + + + align:start position:0% +pulled in they're going to move to the +left the by the electric field they'll + + align:start position:0% +left the by the electric field they'll + + + align:start position:0% +left the by the electric field they'll +be pulled into the npl region and + + align:start position:0% +be pulled into the npl region and + + + align:start position:0% +be pulled into the npl region and +deplete some of the blond uh in the + + align:start position:0% +deplete some of the blond uh in the + + + align:start position:0% +deplete some of the blond uh in the +region past the junction and you end up + + align:start position:0% +region past the junction and you end up + + + align:start position:0% +region past the junction and you end up +with this sort of hump and dip uh which + + align:start position:0% +with this sort of hump and dip uh which + + + align:start position:0% +with this sort of hump and dip uh which +is a non- ficking type of of motion but + + align:start position:0% +is a non- ficking type of of motion but + + + align:start position:0% +is a non- ficking type of of motion but +induced by uh the electric field created + + align:start position:0% +induced by uh the electric field created + + + align:start position:0% +induced by uh the electric field created +by the higher concentration arsenic uh + + align:start position:0% +by the higher concentration arsenic uh + + + align:start position:0% +by the higher concentration arsenic uh +species so this can have quite a bit uh + + align:start position:0% +species so this can have quite a bit uh + + + align:start position:0% +species so this can have quite a bit uh +of an effect on the the diffusion + + align:start position:0% +of an effect on the the diffusion + + + align:start position:0% +of an effect on the the diffusion +profiles uh near a junction and we see + + align:start position:0% +profiles uh near a junction and we see + + + align:start position:0% +profiles uh near a junction and we see +this all the time in our devices in fact + + align:start position:0% +this all the time in our devices in fact + + + align:start position:0% +this all the time in our devices in fact +you go on to slide number + + align:start position:0% +you go on to slide number + + + align:start position:0% +you go on to slide number +23 showing uh a simulation example of an + + align:start position:0% +23 showing uh a simulation example of an + + + align:start position:0% +23 showing uh a simulation example of an +in mosfet this is these are two supreme + + align:start position:0% +in mosfet this is these are two supreme + + + align:start position:0% +in mosfet this is these are two supreme +simulations both 5,000 de uh for mosfets + + align:start position:0% +simulations both 5,000 de uh for mosfets + + + align:start position:0% +simulations both 5,000 de uh for mosfets +you'll recognize the poly silic gate + + align:start position:0% +you'll recognize the poly silic gate + + + align:start position:0% +you'll recognize the poly silic gate +here in the + + align:start position:0% +here in the + + + align:start position:0% +here in the +magenta um and the source and drains uh + + align:start position:0% +magenta um and the source and drains uh + + + align:start position:0% +magenta um and the source and drains uh +regions are Arsenic and they are shown + + align:start position:0% +regions are Arsenic and they are shown + + + align:start position:0% +regions are Arsenic and they are shown +in black um if you look first at the + + align:start position:0% +in black um if you look first at the + + + align:start position:0% +in black um if you look first at the +left in the case of no electric field um + + align:start position:0% +left in the case of no electric field um + + + align:start position:0% +left in the case of no electric field um +you see uh these these different + + align:start position:0% +you see uh these these different + + + align:start position:0% +you see uh these these different +Contours the green yellow uh sort of + + align:start position:0% +Contours the green yellow uh sort of + + + align:start position:0% +Contours the green yellow uh sort of +light orange and then dark orange or red + + align:start position:0% +light orange and then dark orange or red + + + align:start position:0% +light orange and then dark orange or red +um we see the Boron sort of uniformly + + align:start position:0% +um we see the Boron sort of uniformly + + + align:start position:0% +um we see the Boron sort of uniformly +doped and um its Contours are shown by + + align:start position:0% +doped and um its Contours are shown by + + + align:start position:0% +doped and um its Contours are shown by +the different + + align:start position:0% +the different + + + align:start position:0% +the different +colors uh and now what happens on the + + align:start position:0% +colors uh and now what happens on the + + + align:start position:0% +colors uh and now what happens on the +right in the presence of electric field + + align:start position:0% +right in the presence of electric field + + + align:start position:0% +right in the presence of electric field +instead of these sort of uniform lateral + + align:start position:0% +instead of these sort of uniform lateral + + + align:start position:0% +instead of these sort of uniform lateral +doping Contours full of L you see uh + + align:start position:0% +doping Contours full of L you see uh + + + align:start position:0% +doping Contours full of L you see uh +they there's a um electric field that + + align:start position:0% +they there's a um electric field that + + + align:start position:0% +they there's a um electric field that +sort of Acts on the blor and and L + + align:start position:0% +sort of Acts on the blor and and L + + + align:start position:0% +sort of Acts on the blor and and L +changes uh the dop and distribution in + + align:start position:0% +changes uh the dop and distribution in + + + align:start position:0% +changes uh the dop and distribution in +its shape in fact they Dom it dominates + + align:start position:0% +its shape in fact they Dom it dominates + + + align:start position:0% +its shape in fact they Dom it dominates +the shape of the blonde distribution + + align:start position:0% +the shape of the blonde distribution + + + align:start position:0% +the shape of the blonde distribution +particularly near the source drain + + align:start position:0% +particularly near the source drain + + + align:start position:0% +particularly near the source drain +Junctions of a mosfet device the blonde + + align:start position:0% +Junctions of a mosfet device the blonde + + + align:start position:0% +Junctions of a mosfet device the blonde +basically gets pulled in to underneath + + align:start position:0% +basically gets pulled in to underneath + + + align:start position:0% +basically gets pulled in to underneath +the source and drains and there's quite + + align:start position:0% +the source and drains and there's quite + + + align:start position:0% +the source and drains and there's quite +a bit of loss of blond from the channel + + align:start position:0% +a bit of loss of blond from the channel + + + align:start position:0% +a bit of loss of blond from the channel +into the source drains uh that do + + align:start position:0% +into the source drains uh that do + + + align:start position:0% +into the source drains uh that do +electric field effect it's not predicted + + align:start position:0% +electric field effect it's not predicted + + + align:start position:0% +electric field effect it's not predicted +on the on the left hand side so even + + align:start position:0% +on the on the left hand side so even + + + align:start position:0% +on the on the left hand side so even +though H the h factor the enhancement in + + align:start position:0% +though H the h factor the enhancement in + + + align:start position:0% +though H the h factor the enhancement in +the Arsenic diffusivity is limited to uh + + align:start position:0% +the Arsenic diffusivity is limited to uh + + + align:start position:0% +the Arsenic diffusivity is limited to uh +at most a factor to so there's not too + + align:start position:0% +at most a factor to so there's not too + + + align:start position:0% +at most a factor to so there's not too +much effect on the Junction in the ARs + + align:start position:0% +much effect on the Junction in the ARs + + + align:start position:0% +much effect on the Junction in the ARs +this in the black + + align:start position:0% +this in the black + + + align:start position:0% +this in the black +Junctions uh RS don't change that + + align:start position:0% +Junctions uh RS don't change that + + + align:start position:0% +Junctions uh RS don't change that +significantly but it dominates the + + align:start position:0% +significantly but it dominates the + + + align:start position:0% +significantly but it dominates the +diffusion of the Boron + + align:start position:0% +diffusion of the Boron + + + align:start position:0% +diffusion of the Boron +underneath or at a lower + + align:start position:0% + + + + align:start position:0% + +concentration so let's go on to slide + + align:start position:0% +concentration so let's go on to slide + + + align:start position:0% +concentration so let's go on to slide +number 25 I just want to summarize uh + + align:start position:0% +number 25 I just want to summarize uh + + + align:start position:0% +number 25 I just want to summarize uh +this second lecture on diffusion we + + align:start position:0% +this second lecture on diffusion we + + + align:start position:0% +this second lecture on diffusion we +reviewed uh a few cases of simple + + align:start position:0% +reviewed uh a few cases of simple + + + align:start position:0% +reviewed uh a few cases of simple +constant diusivity um these generally + + align:start position:0% +constant diusivity um these generally + + + align:start position:0% +constant diusivity um these generally +apply well uh to uh the case of low + + align:start position:0% +apply well uh to uh the case of low + + + align:start position:0% +apply well uh to uh the case of low +doping concentrations uh in a seamless + + align:start position:0% +doping concentrations uh in a seamless + + + align:start position:0% +doping concentrations uh in a seamless +process flow that usually lean to + + align:start position:0% +process flow that usually lean to + + + align:start position:0% +process flow that usually lean to +diffusion of the seamless Wells which + + align:start position:0% +diffusion of the seamless Wells which + + + align:start position:0% +diffusion of the seamless Wells which +are fairly lightly doped uh say below + + align:start position:0% +are fairly lightly doped uh say below + + + align:start position:0% +are fairly lightly doped uh say below +mid 10 the 17th or below 10 to the 18th + + align:start position:0% +mid 10 the 17th or below 10 to the 18th + + + align:start position:0% +mid 10 the 17th or below 10 to the 18th +they usually diffused in at very high + + align:start position:0% +they usually diffused in at very high + + + align:start position:0% +they usually diffused in at very high +temperatures and subi is large and they + + align:start position:0% +temperatures and subi is large and they + + + align:start position:0% +temperatures and subi is large and they +satisfy the fact that the the dop and + + align:start position:0% +satisfy the fact that the the dop and + + + align:start position:0% +satisfy the fact that the the dop and +conentration is less than an I so you + + align:start position:0% +conentration is less than an I so you + + + align:start position:0% +conentration is less than an I so you +have constant diffusivities + + align:start position:0% +have constant diffusivities + + + align:start position:0% +have constant diffusivities +but beyond that case there uh turns out + + align:start position:0% +but beyond that case there uh turns out + + + align:start position:0% +but beyond that case there uh turns out +most diffusion problems in uh in devices + + align:start position:0% +most diffusion problems in uh in devices + + + align:start position:0% +most diffusion problems in uh in devices +need to be solved + + align:start position:0% +need to be solved + + + align:start position:0% +need to be solved +numerically and we introduced a very + + align:start position:0% +numerically and we introduced a very + + + align:start position:0% +numerically and we introduced a very +simple but uh powerful method for a + + align:start position:0% +simple but uh powerful method for a + + + align:start position:0% +simple but uh powerful method for a +numerical solution with the fusion + + align:start position:0% +numerical solution with the fusion + + + align:start position:0% +numerical solution with the fusion +equation and it actually was a finite + + align:start position:0% +equation and it actually was a finite + + + align:start position:0% +equation and it actually was a finite +difference formula formula it's not it's + + align:start position:0% +difference formula formula it's not it's + + + align:start position:0% +difference formula formula it's not it's +not that sophisticated and it's not + + align:start position:0% +not that sophisticated and it's not + + + align:start position:0% +not that sophisticated and it's not +actually the formulation that use is + + align:start position:0% +actually the formulation that use is + + + align:start position:0% +actually the formulation that use is +using Supreme for but gives you an idea + + align:start position:0% +using Supreme for but gives you an idea + + + align:start position:0% +using Supreme for but gives you an idea +if you needed to write your own simple + + align:start position:0% +if you needed to write your own simple + + + align:start position:0% +if you needed to write your own simple +uh method + + align:start position:0% +uh method + + + align:start position:0% +uh method +um the uh we talked about the first type + + align:start position:0% +um the uh we talked about the first type + + + align:start position:0% +um the uh we talked about the first type +of modification we need to make to fix + + align:start position:0% +of modification we need to make to fix + + + align:start position:0% +of modification we need to make to fix +uh first law and that was for electric + + align:start position:0% +uh first law and that was for electric + + + align:start position:0% +uh first law and that was for electric +field effects which can enhance the + + align:start position:0% +field effects which can enhance the + + + align:start position:0% +field effects which can enhance the +diffusivity of a high concentration + + align:start position:0% +diffusivity of a high concentration + + + align:start position:0% +diffusivity of a high concentration +species uh up to a factor two but can + + align:start position:0% +species uh up to a factor two but can + + + align:start position:0% +species uh up to a factor two but can +dramatically impact the motion of + + align:start position:0% +dramatically impact the motion of + + + align:start position:0% +dramatically impact the motion of +species at lower + + align:start position:0% +species at lower + + + align:start position:0% +species at lower +concentrations and what we're going to + + align:start position:0% +concentrations and what we're going to + + + align:start position:0% +concentrations and what we're going to +talk about next time are further um sort + + align:start position:0% +talk about next time are further um sort + + + align:start position:0% +talk about next time are further um sort +of Corrections to the simple uh uh piing + + align:start position:0% +of Corrections to the simple uh uh piing + + + align:start position:0% +of Corrections to the simple uh uh piing +diffusion that we've been talking about + + align:start position:0% +diffusion that we've been talking about + + + align:start position:0% +diffusion that we've been talking about +and more realistic doping profiles such + + align:start position:0% +and more realistic doping profiles such + + + align:start position:0% +and more realistic doping profiles such +as the case uh when we have + + align:start position:0% +as the case uh when we have + + + align:start position:0% +as the case uh when we have +concentration dependent dependent defic + + align:start position:0% +concentration dependent dependent defic + + + align:start position:0% +concentration dependent dependent defic +okay that's all I have for today and + + align:start position:0% +okay that's all I have for today and + + + align:start position:0% +okay that's all I have for today and +thanks very + + align:start position:0% + + + + align:start position:0% + +much \ No newline at end of file diff --git a/FdwTROVfEPE.txt b/FdwTROVfEPE.txt new file mode 100644 index 0000000000000000000000000000000000000000..b62c6ae079e16d295f2d7987cd35ca9725cda3b3 --- /dev/null +++ b/FdwTROVfEPE.txt @@ -0,0 +1,1941 @@ +The following content is +provided under a Creative + +Commons License. + +Your support will help MIT +OpenCourseWare continue to + +offer high quality educational +resources for free. + +To make a donation, or to view +additional materials from + +hundreds of MIT courses, visit +MIT OpenCourseWare at + +ocw.mit.edu. + +PROFESSOR: Hi. + +Today's lesson, well, I +settled for the title, + +"Circular Functions." But I +guess it could have been + +called a lot of different +things. + +It could've been called +'Trigonometry without + +Triangles'. + +It could have been called +'Trigonometry Revisited'. + +And the whole point is that much +of what today's lecture + +hinges on is a hang-up that +bothered me, and which I think + +may bother you and is worthwhile +discussing. + +I remember, when I was in +high school, I asked my + +trigonometry teacher, why +would I have to know + +trigonometry? + +And his answer was, +surveyors use it. + +And at that particular time, I +didn't know what I was going + +to be, but I knew what +I wasn't going to be. + +I wasn't going to +be a surveyor. + +And I kind of took the course +kind of lightly, and really + +got clobbered a year or two +later when I got into calculus + +and physics courses. + +So what I would like to do +today is to introduce the + +notion of what we call circular +functions, and point + +out what the connection is +between these and the + +trigonometric functions that we +learned when we studied the + +subject that we call +trigonometry, and which might + +better have been called +numerical geometry. + +Let me get to the point +right away. + +Let's imagine that I say +circular functions to you. + +I think it's rather natural +that, as soon as I say that, + +you think of a circle. + +And because you think of a +circle, let me draw a circle + +here, and let me assume that the +radius of the circle is 1. + +In other words, I have the +circle here, 'x squared' plus + +'y squared' equals 1. + +Now, the thing is this. + +When I talk about-- + +And I'm assuming now that you +are familiar with the + +trigonometric functions in +the traditional sense. + +And in fact, the first section +of our supplementary notes in + +the reading material that goes +with the present lecture takes + +care of the fact that, if you +don't recall some of these + +things too well, there's ample +opportunity for refreshing + +your minds and getting +some review in here. + +But the idea is something +like this. + +When we're talking about +calculus, we talk about + +functions of a real variable. + +We are assuming that our +functions have the property + +that the domain is a set of +suitably chosen real numbers, + +and the image is a suitably +chosen set of real numbers. + +We do not think of inputs +as being angles and + +things of this type. + +And so the question is, how can +we define, for example-- + +let's call it the +'sine machine'. + +Let me come down here. + +I'll call it the +'sine machine'. + +If the input is the number 't', +I want the output, say, + +to be 'sine t'. + +But you see, now I'm talking +about a number, not an angle. + +Well, one way of doing this +thing visually is the old idea + +of the number line. + +Let us think of a number as +being a length, the same as we + +do in coordinate geometry. + +We knock off lengths along the +x-axis and the y-axis. + +Let me think of 't' +as being a length. + +As such, I can take 't' and lay +it off along my circle in + +such a way that the length +originates at 'S' and + +terminates, shall we say, +at some point 'P' whose + +coordinates are 'x' and 'y'. + +Now, notice what I'm +saying here. + +I lay the length off along +the circumference. + +I'll talk more about that +a little bit later. + +Now, so far, so good. + +No mention of the word "angle" +here or anything like this. + +Now, wherever t terminates-- and +again, conventions here, + +if 't' is positive, I lay if +off along the circle in the + +so-called positive direction, +namely, what? + +Counter-clockwise. + +If 't' is negative, I'll lay +it off in the clockwise + +direction, et cetera. + +The usual trigonometric +conventions. + +Now what I do is is, at the +point 'P', I drop a + +perpendicular. + +And I define the sine of 't' +to be the length, 'PR', and + +the cosine of 'P' to be +the length, 'OR'. + +In other words, I could +write that like this. + +I could write down that I'm +defining 'sine t' to be the + +length of 'RP' in that +direction, meaning, of course, + +that this is just a fancy way of +saying that the sine of 't' + +will just be the y-coordinate +of the point at which the + +length 't' terminates +on the circle. + +And in a similar way, 'cosine t' +will be the directed length + +from 'O' to 'R', or more +conventionally, the + +x-coordinate. + +Now, notice I can do this +with any length. + +Whatever length I'm given, I +just mark this length off. + +It's a finite length. + +Eventually, it has +to terminate some + +place on the circle. + +Wherever it terminates, the +x-coordinate of the point of + +termination is called the +cosine of 't', and the + +y-coordinate is called +the sine of 't'. + +And notice that, in this way, +both the sine and the cosine + +are functions which map real +numbers into real numbers. + +So that part, I hope, +is clear. + +Notice again, I can mimic +the usual traditional + +trigonometry. + +I can define the tangent of t +to be the number 'sine t', + +divided by the number 'cosine +t', et cetera. + +And I'll leave those details +to the reading material. + +I can ascertain rather +interesting results the same + +way as I could in regular +traditional trigonometry. + +In fact, I can get some certain +results very nicely. + +I remember, for example-- + +Well, I won't even +go into these. + +But how did you talk about the +sine of 0 when one talked + +about traditional +trigonometry? + +How did you embed a 0-degree +angle into a triangle, and + +things of this type. + +Notice that in terms of +my tradition here-- + +and we'll summarize these +results in a minute-- but + +notice, for example, that the +sine of 0 comes out to be 0 + +very nicely, because when +'t' is 0, the length 0 + +terminates at 'S'. + +'S' is on the x-axis. + +That makes, what? +'y' equal to 0. + +Notice also that, if the radius +of my circle is 1, the + +circumference is 2 pi. + +So for example, what I usually +think of a 90-degree angle + +would be the length pi/2. + +And without making any fuss over +this, again, leaving most + +of the details to the reading +and to the simplicity of just + +plugging these things in, we +arrive at these rather + +familiar results. + +We also get, very quickly, in +addition to these results, + +things like the fundamental +result that we always like + +with trigonometric functions. + +That's 'sine squared t' plus +'cosine squared t' is 1. + +And how do we know that? + +Remember that 'cosine t' was +just another name for the + +x-coordinate at which the point + +terminated on the circle. + +In other words, notice +that 'cosine + +squared t' is 'x squared'. + +'Sine squared t' +is 'y squared'. + +The x-coordinate and the +y-coordinate are related by + +the fact that, what? + +The sum of the squares to be on +the circle is equal to 1. + +We could even graph 'sine t' +without any problem at all. + +Namely, we observe that when +'t' is 0, 'sine t' is 0. + +Notice that as we go along the +circle, the sine increases up + +until we get to pi/2, at which +it peaks at 1, then decreases + +at pi, back down to 0. + +And if that's giving you trouble +to follow, let's + +simply come back to our diagram +to make sure that we + +understand this. + +In other words, all we're saying +is, as 't' gets longer, + +its y-coordinate increases from +0 to a maximum of 1, when + +the particle was over here. + +Then, as 't' goes from to pi/2 +to pi, the length of the + +y-coordinate decreases until +it again becomes 0. + +And again, without making much +more ado over this, we get the + +usual curve that we associate +with the sine function even + +when we thought of it +as a traditional + +trigonometric problem. + +But the major point that I want +you to see right now-- + +and we won't worry about +why I want to do this-- + +I can define the trigonometric +functions in such a way that + +their domains are real numbers +rather than angles. + +And in fact, this is the main +reason why people invented the + +notion of radian measure. + +Let me see if I can't make that +a little bit clearer, + +once and for all. + +You see, the question is this. + +Let's suppose I'm talking-- + +Oh, let me give you some +letters over here. + +We'll put a 'Q' over here. + +Let's talk about angle, 'QOS'. + +That's a right angle. + +It's 1/4 of a rotation +of the circle. + +Now, the question that I have +in mind is, if something is + +1/4 of a rotation, why do you +need two different ways of + +saying that? + +Why do we have to say it's 90 +degrees or pi/2 radians, and + +bring in a new measure when we +already have another way of + +measuring circles, angles +of circles? + +The idea is something +like this. + +Let's again mimic the idea of +taking the length 't' and + +laying it off along the +circle like this. + +Now, here's the idea. + +Remember, the radius of +this circle is 1. + +So notice that 'PR', in other +words, this y-coordinate, is + +what we call, by definition, +the sine of 't'. + +In other words, just above we +said that 'sine t' was the + +length 'R' to 'P' in +that direction. + +Now, the point is, I said +disregard traditional + +trigonometry, but we can't +really disregard it. + +It exists. + +For the person who's had +traditional trigonometry, how + +would he tend to look at this +length divided by this length? + +He would think of that +as being what? + +It's side opposite +over hypotenuse. + +That also suggests sine. + +And the sine of what? + +Well, the sine of what +angle this is. + +Now, the thing is this. + +Somehow or other, to avoid +ambiguity, if we could have + +called whatever measure this +angle was measured in terms + +of, if we could have called +that unit 't', then notice + +that the sine of the angle 't' +would have been numerically + +the same as the sine +of the number 't'. + +And again, if this seems like a +hard point to understand, we + +explore this in great +detail in our notes. + +But the idea is this. + +You see, somehow or other, if +'sine t' is going to have two + +different meanings, we would +like to make sure that we pick + +the kind of a unit where it +makes no difference whether + +you're thinking of 't' as being +a number or thinking of + +'t' as being a length. + +For example, suppose I now +invent the word "radian" to + +mean the following. + +An angle is said to +have 't' radians. + +If, when made the central angle +of a unit circle, a + +circle whose radius is 1, it +subtends an arc whose length + +is 't' units of length. + +See, in other words, I would +define the measure called + +radians so that an angle of +'t' radians intercepts the + +length 't' over here. + +In that way, 'sine t' is +unambiguous whether you're + +talking about an angle +or a length. + +For example, when I say +the sine of pi/1 + +radians, what do I mean? + +I mean the angle which is the +sine of the angle which + +intercepts a length, an +arc, pi/2 units long. + +Well, see, pi/2 is +this length. + +I'm now talking about +this angle here. + +And the sine, therefore, of +pi/2 radians, in terms of + +classical trigonometry, is 1. + +But that's also what the sine +of a number pi/2 was. + +This explains the convention +that one says when one uses + +radians, you can leave +the label off. + +All we're saying is that, if +we had used degrees, there + +would have been an ambiguity. + +Certainly, the sine of 3 +degrees is not the same + +as the sine of 3. + +You see, 3 degrees is a +rather small angle. + +But 3 is a rather great length +when you're talking about the + +arc of the unit circle here. + +Remember, 1/2 circle is pi units +long, so 3 would be just + +about this long. + +In other words, notice that 3 +radians and 3 degrees are + +entirely different things. + +But the beauty is what? + +That if we agreed to use radian +measure, then we have + +no ambiguity when we talk +about the sine. + +The sine of the number 't' will +equal the sine of the + +angle 't' radians. + +The cosine of a number 't' will +equal the cosine of the + +angle 't' radians. + +In a certain sense, it was +analogous to when we talked + +about the derivative 'dy/dx', +then wanted to define + +differentials 'dy' and 'dx' +separately, so that 'dy' + +divided by 'dx' would be the +same as 'dy/dx', that we + +wanted to avoid any ambiguity +where the same symbol could be + +interpreted in two different +ways to give + +two different answers. + +By the way, again, there is +nothing sacred about our + +choice of why we pick +circular functions. + +We could have picked hyperbolic +functions. + +Namely, why couldn't we have +started, say, with one branch + +of the hyperbola, 'x squared' +minus 'y squared' equals 1. + +Given a length 't', why couldn't +we have measured 't' + +off along the hyperbola? + +Say this way if 't' is positive, +the other way if 't' + +is negative. + +And then what we could +have done is drop the + +perpendicular again. + +And we could have +defined what? + +The y-coordinate to +be the hyperbolic. + +Well, we couldn't call it cosine +anymore because it + +would be confused with the +circular functions. + +We could have invented a name, +as we later will, called the + +'hyperbolic cosine'. + +I won't go into any more +detail on this. + +See, this is an abbreviation +for hyperbolic + +cosine, meaning this-- + +I'm sorry, I got +this backwards. + +Call the x-coordinate the +hyperbolic cosine, the + +y-coordinate the hyperbolic +sine. + +You don't have to know anything +about advanced + +mathematics to see this. + +All I'm saying is, I could just +as easily have taken any + +geometric figure, marked off +lengths along it, taken the + +x-coordinates and the +y-coordinates, and seen what + +relationships they obey. + +You see, as such, there's +nothing sacred about working + +on a circle. + +Not only that, but even after +you agree to work on the + +circle, there are many +other ways that one + +could have done this. + +For example, someone might have +said, look it, when you + +take this length called 't', why +did you elect to mark it + +off along the circle? + +Why couldn't you have taken a +radius equal to 't', taken 'S' + +as a center, and swung an arc +that met the circle, and call + +this length 't'? + +You see, instead of measuring +along the circle, measure + +along the straight line. + +Again, you could have done +this if you wanted to. + +Why you would've wanted +to do this? + +Well, you have the same +right to do this + +as I had to do mine. + +Of course, you have to be +a little bit careful. + +For example, in this particular +configuration, + +notice that, if this is how +you're going to define your + +trigonometric function, your +input, your domain, has to be + +somewhere between 0 and 2. + +In other words, you cannot have +a length longer than 2, + +because notice that the +diameter of the + +circle is only 2. + +And therefore, if 't' were +greater than 2, when you swung + +an arc from the point 'S', +it wouldn't meet + +the circle at all. + +Well, that's no great +handicap. + +It's no great disaster. + +You still have the right +to make up whatever + +functions you want. + +I will try to make it clearer +why we chose these circular + +functions from a physical point +of view as we go along. + +What I thought I'd like to do +now is, having motivated, that + +we can invent the trigonometric +functions in + +terms of numbers definitions +along this circle. + +And coupled with the fact that, +in radian measure, you + +can have a very nice +identification between what's + +happening pictorially and what's +happening analytically, + +to show, for example, that in +terms of our subject called + +calculus, that we're pretty much +home free once we learn + +these basic ideas. + +You see, the important point +is that, in a manner of + +speaking, we have finished +differential calculus. + +We know what all the recipes +are We know what properties + +things have. + +So all of the rules that we +learned will apply to any + +particular type of function +that we're talking about. + +For example, let's suppose +we define 'f of + +x' to be 'sine x'. + +And we want to find the +derivative of 'sine x'. + +Notice that 'f prime of x' +evaluated at any number 'x1' + +has already been +defined for us. + +It's the limit as 'delta x' +approaches 0, 'f of 'x1 plus + +delta x'', minus 'f of +x1' over 'delta x'. + +This is true for any +function 'f'. + +In particular, if 'f of x' is +'sine x', all we get is what? + +That the derivative is the limit +as 'delta x' approaches + +0, sine of 'x1 plus delta +x' minus sine of + +'x1' over 'delta x'. + +Now you see, on this +particular score, + +nobody can fault us. + +This is still the basic +definition. + +All that happens computationally +is that, if + +we're not familiar with our +new functions called the + +trigonometric functions, we +might not know how to express + +sine of 'x1 plus delta x' in +a more convenient form. + +What do we mean by a more +convenient form? + +Well, notice again, as is always +the case when we take a + +derivative, as delta x +approaches 0, our numerator + +becomes 'sine x1' minus 'sine +x1', which is 0/0. + +And we're back to our familiar +taboo form of 0/0. + +Somehow or other, we're going +to have to make a refinement + +on our numerator that +will allow us to get + +rid of a 0/0 form. + +Well, to make a long story +short, if we happen to know + +the addition formula +for the sine-- + +in other words, 'sine 'x1 plus +delta x'' is ''sine x1' + +'cosine delta x'', plus ''sine +delta x' 'cosine x1''-- + +then we subtract off 'sine x1' +and divide by 'delta x', and + +then we factor and +collect terms. + +We see what? + +Without any knowledge +of calculus at + +all, but just what? + +By our definition of derivative, +just by our + +definition, coupled with +properties of the + +trigonometric functions, we wind +up with the fact that 'f + +prime of x1' is this +particular limit. + +Now certainly, our limit +theorems don't change. + +The limit of a sum is +still going to be + +the sum of the limits. + +The limit of a product +will still be the + +product of the limits. + +So all in all, what we have to +sort of do is figure out what + +these limits will be. + +Certainly, as 'delta x' +approaches 0, this will stay + +'cosine x1'. + +Certainly this will stay 'sine +x1', because 'x1' is a fixed + +number that doesn't depend +on 'delta x'. + +But notice, rather +interestingly, that both of my + +expressions in parentheses +happen to take on that 0/0 + +form if we're not careful. + +Namely, if you replace 'delta +x' by 0, sine 0 is 0, 0/0 is + +0, and we run into trouble here +if we replace 'delta x' + +by 0, which of course +we can't do. + +This is the same definition +of limit as we had before. + +'Delta x' gets arbitrarily +close to 0, but never is + +allowed to get there. + +Well, you see, if nothing else, +this motivates why we + +would like to learn this +particular type of limit. + +In other words, what we would +like to know is, how do you-- + +the 'delta x' symbol here +isn't that important. + +'Delta x' just stands +for any number. + +Notice that what we would like +to know is, if you take the + +sine of something over that same +something, and take the + +limit as that same something +goes to 0, we would like to + +know what that becomes. + +In a similar way, we would like +to know how to handle + +this quotient here, because +notice that when 'delta x' is + +0, cosine 0 is 1. + +This is 1 minus 1 over 0. + +It's another 0/0 form. + +So the problem that we're +confronted with is that, what + +we would like to do is to figure +out how to handle the + +limit of 'sine t' over 't' +as 't' approaches 0. + +Now, what's 't' here? +'t' is a number. + +Remember that. + +This is the big pitch +I've been making. + +We're thinking of +'t' as a number. + +If, on the other hand, you feel +more comfortable thinking + +in terms of traditional +trigonometry-- + +and let's face it, the more +background you've had in + +traditional trigonometry, the +more comfortable you're going + +to feel using it. + +Let's simply agree to do this, +that if it bothers you to + +think of this as a length +divided by a length, et + +cetera, and that this is a +length or a number, let's + +agree that we will go back to +angles but use radian measure. + +Why? + +Because if the angle is measured +in radians, the sine + +of the angle 't' radians is the +same as the number, the + +sine, of the number 't'. + +Well again, here's how this +problem is tackled. + +What we do is we mark off the +angle of 't' radians. + +Remember that we have +the unit circle. + +And what we very cleverly do +is we catch our wedge, our + +circular wedge, between +two right triangles. + +Again, without making a big +issue over this, notice that + +this length is 'sine t', this +length is 'cosine t', so the + +area of the small triangle +is 'sine t' times + +'cosine t' over 2. + +See, 'sine t' times +'cosine t' over 2. + +Now, on the other hand, since +that's caught in our wedge, + +what is the area of our wedge? + +Well, since the area of the +entire circle is pi-- see, pi + +'R squared' and 'R' is 1-- + +since the area of the entire +circle is pi-- + +and we're taking what? + +'t' of the 2pi. + +So there are two pi radians +in a circle. + +So the sector of the circle that +we have, it's 't/2pi' of + +the entire circle. + +And by the way, this is done +more rigorously and carried + +out in detail in the notes. + +Let me point out that, if we +insisted on working with + +degrees, instead of +'t/2pi', we just + +would have had 't/360'. + +Because, you see, if we're +dealing with degrees, the + +entire angle and measure of the +circle is 360 degrees, and + +we would have had 't/360'. + +But here we've used the +fact that we're + +dealing with radians. + +And finally, the bigger +triangle, which includes the + +wedge, has, as its base, 1, +so that's the radius. + +And since the tangent is side +opposite over side adjacent, + +this length is 'tangent t'. + +And so what we have is what? + +That ''sine t' 'cosine t/2' must +be less than this, which + +in turn must be less than this, +multiplying through by 2 + +and dividing through +by 'sine t'. + +And by the way, this hinges on +the fact that 't' is positive. + +Again, in our notes, we treat +the case where 't' is negative + +to arrive at the same result. + +Remembering that 'tan t' is +'sine t' over 'cosine t', we + +wind up with this result. + +And now, observing that +as 't' approaches 0, + +this approaches 1. + +This also approaches 1. + +And 't' over 'sine t' is caught +between these two. + +We get that the limit of 't' +over 'sine t' as 't' + +approaches 0 is 1. + +Now of course, since this limit +is 1, the limit of the + +reciprocal of this will be +the reciprocal of this. + +But what's very nice about the +number 1 is that it's equal to + +its own reciprocal. + +In other words, what we've now +shown is that the limit of + +'sine t' over 't' as 't' +approaches 0 is 1. + +That, as I said before, +is done in the text. + +We do it in our notes. + +But the thing that I hope this +motivates is why we want to do + +this in the first place. + +Notice that this was a limit +that we had to compute if we + +wanted to compute the derivative +of the sine. + +Now, the next thing was, how +do we handle '1 - cosine t' + +over 't' as 't' approaches 0? + +Again, leaving the details to +you to sketch in as you see + +fit, let me point out simply +what the mathematics + +involved here is. + +You see, what we can handle +is 'sine t' over 't'. + +That means that what we would +like to do is, whenever we're + +given an alien form, we would +somehow or other like to + +figure some way of factoring +a sine t over + +t out of this thing. + +When you look at '1 - cosine +t', the identity, 'sine + +squared' equals '1 - 'cosine +squared t'', + +should suggest itself. + +Now, how do you get from '1 - +cosine t' to '1 - 'cosine + +squared t''? + +You have to multiply +by '1 + cosine t'. + +And if you multiply by '1 + +cosine t' upstairs, you must + +multiply by '1 + cosine +t' downstairs. + +By the way, the only time you +can't multiply by something is + +when the thing is 0. + +You can't put that into +the denominator. + +Notice that 'cosine t' is +not 0 in a neighborhood + +of 't' equals 0. + +See, 'cosine t' behaves like 1 +when 't' is near 0, so this is + +a permissible step in this +particular problem. + +The point is, we now factor '1 - +'cosine squared t'' as 'sine + +t' times 'sine t'. + +See, that's 'sine squared t'. + +We break up our 't' times +'1 + cosine t' this way. + +Now we know that the limit of +a product is the product of + +the limits. + +This we already know +goes to 1. + +And as 't' approaches 0, from +our previous limit work on the + +like, notice here, the limit of +a quotient is the quotient + +of the limits, the numerator +goes to 0, the denominator + +goes to 2, because as t +approaches 0, cosine 0 is 1. + +At any rate, that's +0/2, which is 0. + +And so this limit is 0. + +Now, at the risk of giving you +a slight headache as I take + +the board down here, let +me just review what + +it was that we did. + +You see, notice that, without +any knowledge of these limits + +at all, we were able to show +that whatever the derivative + +of 'sine x' was, it was this +particular thing here. + +Now what we've done is we've +shown that this is 1, and + +we've shown that this is 0. + +And using our limit theorems, +what we now see is what? + +That if 'f of x' is 'sine x', 'f +prime of x' is 'cosine x'. + +Let me just write that down over +here, that if 'y' equals + +'sine x', 'dy/dx' +is 'cosine x'. + +And again, notice how much of +the calculus involved here was + +nothing new. + +It goes back to the so-called +baby chapter that nobody + +likes, where we go back to +epsilons, deltas, you see + +derivatives by 'delta +x', et cetera. + +See, those recipes always +remain the same. + +What happens is, as you invent +new functions, you need a + +different degree of +computational sophistication + +to find the desired limits. + +By the way, once you get over +these hurdles, everything + +again starts to go smoothly +as before. + +For example, our chain rule. + +Suppose we have now that 'y' +equals 'sine u', where 'u' is + +some differentiable +function of 'x'. + +And we now want to +find the 'dy/dx'. + +Well, you see, the point is +that we know that the + +derivative of 'sine u' with +respect to 'u' would be + +'cosine u'. + +What we want is the derivative +of 'sine u' + +with respect to 'x'. + +And we motivate the chain rule +the same way as we did before. + +It happens to be that we're +dealing with the specific + +value called sine, +but it could've + +been any old function. + +How would you differentiate 'f +of u' with respect to 'x' if + +you know how to differentiate 'f +of u' with respect to 'u'? + +And the answer is, you would +just differentiate with + +respect to 'u', and multiply +that by a derivative of 'u' + +with respect to 'x'. + +In other words, we get +the result what? + +That since 'dy/du' is 'cosine +u', we get that the derivative + +of 'sine u' with respect +to 'x' is + +'cosine u' times 'du/dx'. + +And by the way, one rather nice +application of this is + +that it gives us a very quick +way of getting the derivative + +of 'cosine x'. + +After all, our basic identity +is that 'cosine x' is sine + +pi/2 minus 'x'. + +Again, a number or an +angle, either way. + +As long as the measurement is +in radians, it makes no + +difference whether you think of +this as being an angle or + +being a number. + +The answer will be the same. + +The idea is this. + +To take the derivative of +'cosine x' with respect to + +'x', all I have to differentiate +is sine pi/2 + +minus 'x' with respect to 'x'. + +But I know how to do that. + +Namely, the derivative of sine +pi/2 minus 'x' is cosine pi/2 + +minus 'x,' and by the chain +rule, times the derivative of + +this with respect to 'x'. + +Well, pi/2 is a constant. + +The derivative of 'minus +x' is minus 1. + +And then, remembering that the +cosine of pi/2 minus 'x' is + +'sine x', I now have the result +that the derivative of + +the cosine is minus the sine. + +And again, I can do all sorts +of things this way. + +If I want the derivative of a +tangent, I could write tangent + +as sine over cosine. + +Use the quotient rule. + +You see, as soon as I make one +breakthrough, all of the + +previous body of calculus +comes to my + +rescue, so to speak. + +By the way, what I'd like to do +now is point out why, from + +a physical point of view, we +like circular functions to be + +independent of angles +and the like. + +With the results that we've +derived so far, it's rather + +easy to derive one +more result. + +Namely, let's assume +that a particle is + +moving along the x-axis-- + +I'm going to start with the +answer, sort of, and work + +backwards-- + +according to the rule, 'x' +equals 'sine kt', where 't' is + +time and 'k' is a constant. + +Then its speed, 'dx/dt', +is what? + +It's the derivative of 'sine +kt', which is 'cosine kt', + +times the derivative of what's +inside with respect to 't'. + +In other words, it's +'k cosine kt'. + +The second derivative of 'x' +with respect to 't', namely, + +the acceleration is what? + +How do you differentiate +the cosine? + +The derivative of the cosine +is minus the sine. + +By the chain rule, I must +multiply by the derivative of + +'kt' with respect to 't', which +gives me another factor + +of 't' over here. + +Remembering that 'x' equals +'sine kt', I arrive at this + +particular so-called +differential equation. + +And what does this say? + +It says that 'd2x/ dt squared', +the acceleration, is + +proportional to the +displacement, the distance + +traveled, but in the +opposite direction. + +You see, 'k squared' can't +be negative, so 'minus 'k + +squared'' can't be positive. + +This says what? + +The acceleration is proportional +to the + +displacement, but in the +opposite direction. + +Does that problem require any +knowledge of angles to solve? + +Notice that this is a perfectly + +good physical problem. + +It's known as simple +harmonic motion. + +And all I'm trying to have you +see is that, by inventing the + +circular functions in the proper +way, not only can we do + +their calculus, but even more +importantly, if we reverse + +these steps, for example, we +can show that, to solve the + +physical problem of simple +harmonic motion, we have to + +know the so-called circular +trigonometric functions. + +And this is a far cry, you see, +from using trigonometry + +in the sense that the surveyor +uses trigonometry. + +You see, this ties up with my +initial hang-up that I was + +telling you about at the +beginning of the program. + +By the way, in closing, I should +also make reference to + +something that we pointed out +in our last lecture, namely, + +inverse differentiation. + +Keep in mind, also, that as you +read the calculus of the + +trigonometric functions, that +the fact that we know that the + +derivative of sine u with +respect to 'u' was 'cosine u' + +gives us, with a switch in +emphasis, the result that the + +integral 'cosine u', 'du' is +'sine u' plus a constant. + +And in a similar way, since the +derivative of cosine is + +minus the sine, the integral +of 'sine u' with respect to + +'u' is 'minus cosine +u' plus a constant. + +Be careful. + +Notice how the sines +can screw you up. + +Namely, they're in the opposite +sense when you're + +integrating as when you +were differentiating. + +But again, these are the details +which I expect you can + +have come out in the +wash rather nicely. + +We can continue on this way, +from knowing how to + +differentiate 'sine x' +to the nth power. + +Namely, it's 'n - 1' 'x', times +the derivative of 'sine + +x', which is 'cosine x'. + +We don't want this in here. + +That's a differential form. + +Without going into any detail +here, notice that a + +modification of this shows us +that, if we differentiate + +this, we wind up with this. + +We could now take the time, if +this were the proper place, to + +develop all sorts of derivative +formulas and + +integral formulas. + +As you study your study guide, +you will notice that the + +lesson after this is concerned +with the calculus of the + +circular functions. + +My feeling is is that, with +this as background, a very + +good review of the previous part +of the course will be to + +see how much of this you can +apply on your own to these new + +functions called the +circular functions. + +Next time, we will talk, as +you may be able to guess, + +about the inverse circular +functions + +and why they're important. + +But until next time, goodbye. + +Funding for the publication of +this video was provided by the + +Gabriella and Paul Rosenbaum +Foundation. + +Help OCW continue to provide +free and open access to MIT + +courses by making a donation +at ocw.mit.edu/donate. \ No newline at end of file diff --git a/FkfsmwAtDdY.txt b/FkfsmwAtDdY.txt new file mode 100644 index 0000000000000000000000000000000000000000..cb923c4f9f820e5ab76ee759d41cbf782e264759 --- /dev/null +++ b/FkfsmwAtDdY.txt @@ -0,0 +1,4176 @@ +align:start position:0% + +you've seen a lot of functions in + + align:start position:0% +you've seen a lot of functions in + + + align:start position:0% +you've seen a lot of functions in +introductory calculus trig functions + + align:start position:0% +introductory calculus trig functions + + + align:start position:0% +introductory calculus trig functions +rational functions exponentials logs and + + align:start position:0% +rational functions exponentials logs and + + + align:start position:0% +rational functions exponentials logs and +so on I don't know whether your calculus + + align:start position:0% +so on I don't know whether your calculus + + + align:start position:0% +so on I don't know whether your calculus +course has included a general discussion + + align:start position:0% +course has included a general discussion + + + align:start position:0% +course has included a general discussion +of functions uh the old-fashioned ones + + align:start position:0% +of functions uh the old-fashioned ones + + + align:start position:0% +of functions uh the old-fashioned ones +didn't and we will go into that now in + + align:start position:0% +didn't and we will go into that now in + + + align:start position:0% +didn't and we will go into that now in +this segment and we're going to be + + align:start position:0% +this segment and we're going to be + + + align:start position:0% +this segment and we're going to be +interpreting functions as a special case + + align:start position:0% +interpreting functions as a special case + + + align:start position:0% +interpreting functions as a special case +of binary relations so let's just say + + align:start position:0% +of binary relations so let's just say + + + align:start position:0% +of binary relations so let's just say +what a binary relation is a binary + + align:start position:0% +what a binary relation is a binary + + + align:start position:0% +what a binary relation is a binary +relation is a mathematical object that + + align:start position:0% +relation is a mathematical object that + + + align:start position:0% +relation is a mathematical object that +Associates elements of one set called + + align:start position:0% +Associates elements of one set called + + + align:start position:0% +Associates elements of one set called +The Domain with elements of another set + + align:start position:0% +The Domain with elements of another set + + + align:start position:0% +The Domain with elements of another set +called the co-domain and I'm going to + + align:start position:0% +called the co-domain and I'm going to + + + align:start position:0% +called the co-domain and I'm going to +give you a bunch of examples of binary + + align:start position:0% +give you a bunch of examples of binary + + + align:start position:0% +give you a bunch of examples of binary +relations in a in a short moment but + + align:start position:0% +relations in a in a short moment but + + + align:start position:0% +relations in a in a short moment but +let's just talk about uh what they're + + align:start position:0% +let's just talk about uh what they're + + + align:start position:0% +let's just talk about uh what they're +for and what their role is so they may + + align:start position:0% +for and what their role is so they may + + + align:start position:0% +for and what their role is so they may +be familiar to you as computer + + align:start position:0% +be familiar to you as computer + + + align:start position:0% +be familiar to you as computer +scientists if you've worked with any + + align:start position:0% +scientists if you've worked with any + + + align:start position:0% +scientists if you've worked with any +relational databases like SQL or MySQL + + align:start position:0% +relational databases like SQL or MySQL + + + align:start position:0% +relational databases like SQL or MySQL +my + + align:start position:0% +my + + + align:start position:0% +my +SQL uh and we'll see an example that + + align:start position:0% +SQL uh and we'll see an example that + + + align:start position:0% +SQL uh and we'll see an example that +indicates where the original ideas + + align:start position:0% +indicates where the original ideas + + + align:start position:0% +indicates where the original ideas +behind uh those relational databases + + align:start position:0% +behind uh those relational databases + + + align:start position:0% +behind uh those relational databases +came from but even more fundamental + + align:start position:0% +came from but even more fundamental + + + align:start position:0% +came from but even more fundamental +relations are one of the most basic + + align:start position:0% +relations are one of the most basic + + + align:start position:0% +relations are one of the most basic +mathematical abstractions right after + + align:start position:0% +mathematical abstractions right after + + + align:start position:0% +mathematical abstractions right after +sets and they uh play a role everywhere + + align:start position:0% +sets and they uh play a role everywhere + + + align:start position:0% +sets and they uh play a role everywhere +uh we're going to be looking in later + + align:start position:0% +uh we're going to be looking in later + + + align:start position:0% +uh we're going to be looking in later +lectures at special kinds of binary + + align:start position:0% +lectures at special kinds of binary + + + align:start position:0% +lectures at special kinds of binary +relations like equivalence relations and + + align:start position:0% +relations like equivalence relations and + + + align:start position:0% +relations like equivalence relations and +partial orders uh and uh numerical + + align:start position:0% +partial orders uh and uh numerical + + + align:start position:0% +partial orders uh and uh numerical +congruences + + align:start position:0% +congruences + + + align:start position:0% +congruences +but today we're going to set up the + + align:start position:0% +but today we're going to set up the + + + align:start position:0% +but today we're going to set up the +Machinery to be using binary relations + + align:start position:0% +Machinery to be using binary relations + + + align:start position:0% +Machinery to be using binary relations +for counting which will be another + + align:start position:0% +for counting which will be another + + + align:start position:0% +for counting which will be another +important application uh in this class + + align:start position:0% +important application uh in this class + + + align:start position:0% +important application uh in this class +so let's look at an + + align:start position:0% +so let's look at an + + + align:start position:0% +so let's look at an +example um and I'm going to take one + + align:start position:0% +example um and I'm going to take one + + + align:start position:0% +example um and I'm going to take one +that's close to home the registered for + + align:start position:0% +that's close to home the registered for + + + align:start position:0% +that's close to home the registered for +relation which is a relation between + + align:start position:0% +relation which is a relation between + + + align:start position:0% +relation which is a relation between +students that's going to be the domain + + align:start position:0% +students that's going to be the domain + + + align:start position:0% +students that's going to be the domain +uh in this case four students Jason Joan + + align:start position:0% +uh in this case four students Jason Joan + + + align:start position:0% +uh in this case four students Jason Joan +eway and Adam and + + align:start position:0% +eway and Adam and + + + align:start position:0% +eway and Adam and +subjects uh for subjects as a + + align:start position:0% +subjects uh for subjects as a + + + align:start position:0% +subjects uh for subjects as a +coincidence + + align:start position:0% +coincidence + + + align:start position:0% +coincidence +60423 012 + + align:start position:0% +60423 012 + + + align:start position:0% +60423 012 +and4 and the relation R is going to be + + align:start position:0% +and4 and the relation R is going to be + + + align:start position:0% +and4 and the relation R is going to be +indicated by arrows which show just + + align:start position:0% +indicated by arrows which show just + + + align:start position:0% +indicated by arrows which show just +which students are associated with which + + align:start position:0% +which students are associated with which + + + align:start position:0% +which students are associated with which +subjects meaning that they're registered + + align:start position:0% +subjects meaning that they're registered + + + align:start position:0% +subjects meaning that they're registered +for that subject so if we look at + + align:start position:0% +for that subject so if we look at + + + align:start position:0% +for that subject so if we look at +Jason uh we can see that there there's a + + align:start position:0% +Jason uh we can see that there there's a + + + align:start position:0% +Jason uh we can see that there there's a +particular Arrow connecting Jason and 60 + + align:start position:0% +particular Arrow connecting Jason and 60 + + + align:start position:0% +particular Arrow connecting Jason and 60 +42 and what that tells us is that Jason + + align:start position:0% +42 and what that tells us is that Jason + + + align:start position:0% +42 and what that tells us is that Jason +is registered for + + align:start position:0% +is registered for + + + align:start position:0% +is registered for +6042 now there's a bunch of notations + + align:start position:0% +6042 now there's a bunch of notations + + + align:start position:0% +6042 now there's a bunch of notations +that are used uh with respect to Binary + + align:start position:0% +that are used uh with respect to Binary + + + align:start position:0% +that are used uh with respect to Binary +relations so let's look at some + + align:start position:0% +relations so let's look at some + + + align:start position:0% +relations so let's look at some +um one way to write it is if you think + + align:start position:0% +um one way to write it is if you think + + + align:start position:0% +um one way to write it is if you think +of the relation r as like an equality + + align:start position:0% +of the relation r as like an equality + + + align:start position:0% +of the relation r as like an equality +sign or a less than sign where it's + + align:start position:0% +sign or a less than sign where it's + + + align:start position:0% +sign or a less than sign where it's +normally written in the middle of the + + align:start position:0% +normally written in the middle of the + + + align:start position:0% +normally written in the middle of the +two things that it's connecting as in + + align:start position:0% +two things that it's connecting as in + + + align:start position:0% +two things that it's connecting as in +this example Json R 6042 that would be + + align:start position:0% +this example Json R 6042 that would be + + + align:start position:0% +this example Json R 6042 that would be +called infix not + + align:start position:0% +called infix not + + + align:start position:0% +called infix not +ation um sometimes it's written as a + + align:start position:0% +ation um sometimes it's written as a + + + align:start position:0% +ation um sometimes it's written as a +binary predicate R of Json comma + + align:start position:0% +binary predicate R of Json comma + + + align:start position:0% +binary predicate R of Json comma +6042 that would be kind of prefix + + align:start position:0% +6042 that would be kind of prefix + + + align:start position:0% +6042 that would be kind of prefix +notation where the relation or operator + + align:start position:0% +notation where the relation or operator + + + align:start position:0% +notation where the relation or operator +comes first uh and then uh if you start + + align:start position:0% +comes first uh and then uh if you start + + + align:start position:0% +comes first uh and then uh if you start +being a little closer to the formal + + align:start position:0% +being a little closer to the formal + + + align:start position:0% +being a little closer to the formal +definition of what a binary relation is + + align:start position:0% +definition of what a binary relation is + + + align:start position:0% +definition of what a binary relation is +you could say that the ordered pair Json + + align:start position:0% +you could say that the ordered pair Json + + + align:start position:0% +you could say that the ordered pair Json +6042 is a member of the relation if you + + align:start position:0% +6042 is a member of the relation if you + + + align:start position:0% +6042 is a member of the relation if you +wanted to be really precise you would + + align:start position:0% +wanted to be really precise you would + + + align:start position:0% +wanted to be really precise you would +say that it was a member of the graph of + + align:start position:0% +say that it was a member of the graph of + + + align:start position:0% +say that it was a member of the graph of +the relation and I'll come back and + + align:start position:0% +the relation and I'll come back and + + + align:start position:0% +the relation and I'll come back and +elaborate further on what the graph of a + + align:start position:0% +elaborate further on what the graph of a + + + align:start position:0% +elaborate further on what the graph of a +relation is and uh uh and what this + + align:start position:0% +relation is and uh uh and what this + + + align:start position:0% +relation is and uh uh and what this +ordered pairs business + + align:start position:0% +ordered pairs business + + + align:start position:0% +ordered pairs business +is but for now just let's continue with + + align:start position:0% +is but for now just let's continue with + + + align:start position:0% +is but for now just let's continue with +this example and a basic concept with + + align:start position:0% +this example and a basic concept with + + + align:start position:0% +this example and a basic concept with +relations is the idea of the image of a + + align:start position:0% +relations is the idea of the image of a + + + align:start position:0% +relations is the idea of the image of a +bunch of domain elements under the + + align:start position:0% +bunch of domain elements under the + + + align:start position:0% +bunch of domain elements under the +relation so you can think of the + + align:start position:0% +relation so you can think of the + + + align:start position:0% +relation so you can think of the +relation as an operator that applies to + + align:start position:0% +relation as an operator that applies to + + + align:start position:0% +relation as an operator that applies to +domain elements or even sets of domain + + align:start position:0% +domain elements or even sets of domain + + + align:start position:0% +domain elements or even sets of domain +element elements so if I write R of Json + + align:start position:0% +element elements so if I write R of Json + + + align:start position:0% +element elements so if I write R of Json +that defines the subjects that Json is + + align:start position:0% +that defines the subjects that Json is + + + align:start position:0% +that defines the subjects that Json is +registered for so looking at the picture + + align:start position:0% +registered for so looking at the picture + + + align:start position:0% +registered for so looking at the picture +R is not a function so that there may be + + align:start position:0% +R is not a function so that there may be + + + align:start position:0% +R is not a function so that there may be +more than one subject as is you'd expect + + align:start position:0% +more than one subject as is you'd expect + + + align:start position:0% +more than one subject as is you'd expect +for a student to be registered for + + align:start position:0% +for a student to be registered for + + + align:start position:0% +for a student to be registered for +multiple courses at MIT uh so Jason in + + align:start position:0% +multiple courses at MIT uh so Jason in + + + align:start position:0% +multiple courses at MIT uh so Jason in +this diagram is registered for 6042 and + + align:start position:0% +this diagram is registered for 6042 and + + + align:start position:0% +this diagram is registered for 6042 and +6012 as indicated by the highlighted two + + align:start position:0% +6012 as indicated by the highlighted two + + + align:start position:0% +6012 as indicated by the highlighted two +uh connection app arrows which we've + + align:start position:0% +uh connection app arrows which we've + + + align:start position:0% +uh connection app arrows which we've +made + + align:start position:0% +made + + + align:start position:0% +made +red uh which means that R of Json is + + align:start position:0% +red uh which means that R of Json is + + + align:start position:0% +red uh which means that R of Json is +that set of two courses that he's + + align:start position:0% +that set of two courses that he's + + + align:start position:0% +that set of two courses that he's +Associated there that he's associated + + align:start position:0% +Associated there that he's associated + + + align:start position:0% +Associated there that he's associated +with or that are associated with him + + align:start position:0% +with or that are associated with him + + + align:start position:0% +with or that are associated with him +that he's registered for 6042 and + + align:start position:0% +that he's registered for 6042 and + + + align:start position:0% +that he's registered for 6042 and +6012 so at this point we've applied R to + + align:start position:0% +6012 so at this point we've applied R to + + + align:start position:0% +6012 so at this point we've applied R to +one domain element one student Json but + + align:start position:0% +one domain element one student Json but + + + align:start position:0% +one domain element one student Json but +the interesting case is when you apply R + + align:start position:0% +the interesting case is when you apply R + + + align:start position:0% +the interesting case is when you apply R +to a bunch of students so the general + + align:start position:0% +to a bunch of students so the general + + + align:start position:0% +to a bunch of students so the general +setup is that if x is a set of students + + align:start position:0% +setup is that if x is a set of students + + + align:start position:0% +setup is that if x is a set of students +students a subset of the domain which + + align:start position:0% +students a subset of the domain which + + + align:start position:0% +students a subset of the domain which +we've been showing in green then if I + + align:start position:0% +we've been showing in green then if I + + + align:start position:0% +we've been showing in green then if I +apply R to X it gives me all the + + align:start position:0% +apply R to X it gives me all the + + + align:start position:0% +apply R to X it gives me all the +subjects that they're taking among them + + align:start position:0% +subjects that they're taking among them + + + align:start position:0% +subjects that they're taking among them +all the subjects that any one of them is + + align:start position:0% +all the subjects that any one of them is + + + align:start position:0% +all the subjects that any one of them is +taken let's take a look at an example um + + align:start position:0% +taken let's take a look at an example um + + + align:start position:0% +taken let's take a look at an example um +well another way to say it I guess is + + align:start position:0% +well another way to say it I guess is + + + align:start position:0% +well another way to say it I guess is +that R ofx is everything in r that + + align:start position:0% +that R ofx is everything in r that + + + align:start position:0% +that R ofx is everything in r that +relates to things in + + align:start position:0% +relates to things in + + + align:start position:0% +relates to things in +X um so if I look at Jason and + + align:start position:0% +X um so if I look at Jason and + + + align:start position:0% +X um so if I look at Jason and +eway and I want to know what are they + + align:start position:0% +eway and I want to know what are they + + + align:start position:0% +eway and I want to know what are they +connected what are what do they connect + + align:start position:0% +connected what are what do they connect + + + align:start position:0% +connected what are what do they connect +to under R these are the subjects that + + align:start position:0% +to under R these are the subjects that + + + align:start position:0% +to under R these are the subjects that +Jason or eway is registered for the way + + align:start position:0% +Jason or eway is registered for the way + + + align:start position:0% +Jason or eway is registered for the way +I'd find that is by looking at the arrow + + align:start position:0% +I'd find that is by looking at the arrow + + + align:start position:0% +I'd find that is by looking at the arrow +diagram and I'd find that Jason is + + align:start position:0% +diagram and I'd find that Jason is + + + align:start position:0% +diagram and I'd find that Jason is +taking 042 and 012 and eway is taking + + align:start position:0% +taking 042 and 012 and eway is taking + + + align:start position:0% +taking 042 and 012 and eway is taking + + align:start position:0% + + + align:start position:0% +and4 so between them they're taking + + align:start position:0% +and4 so between them they're taking + + + align:start position:0% +and4 so between them they're taking +three courses so R of Jason and eway is + + align:start position:0% +three courses so R of Jason and eway is + + + align:start position:0% +three courses so R of Jason and eway is +in fact 042 012 and4 + + align:start position:0% + + + + align:start position:0% + +so another way to understand this idea + + align:start position:0% +so another way to understand this idea + + + align:start position:0% +so another way to understand this idea +of the image of a set R ofx is that X is + + align:start position:0% +of the image of a set R ofx is that X is + + + align:start position:0% +of the image of a set R ofx is that X is +a set of points in the set that you're + + align:start position:0% +a set of points in the set that you're + + + align:start position:0% +a set of points in the set that you're +starting with called The Domain uh and R + + align:start position:0% +starting with called The Domain uh and R + + + align:start position:0% +starting with called The Domain uh and R +ofx is going to be all of the end points + + align:start position:0% +ofx is going to be all of the end points + + + align:start position:0% +ofx is going to be all of the end points +in the other set the code domain that + + align:start position:0% +in the other set the code domain that + + + align:start position:0% +in the other set the code domain that +start at X if I said that as a statement + + align:start position:0% +start at X if I said that as a statement + + + align:start position:0% +start at X if I said that as a statement +in formal logic or in set theory with + + align:start position:0% +in formal logic or in set theory with + + + align:start position:0% +in formal logic or in set theory with +logical notation I would say that r ofx + + align:start position:0% +logical notation I would say that r ofx + + + align:start position:0% +logical notation I would say that r ofx +is the set of J in subjects such that + + align:start position:0% +is the set of J in subjects such that + + + align:start position:0% +is the set of J in subjects such that +there is a D in + + align:start position:0% +there is a D in + + + align:start position:0% +there is a D in +X such that + + align:start position:0% +X such that + + + align:start position:0% +X such that +drj so what that that's exactly saying + + align:start position:0% +drj so what that that's exactly saying + + + align:start position:0% +drj so what that that's exactly saying +that um drj says that D is the starting + + align:start position:0% +that um drj says that D is the starting + + + align:start position:0% +that um drj says that D is the starting +point in the domain D is a student um J + + align:start position:0% +point in the domain D is a student um J + + + align:start position:0% +point in the domain D is a student um J +is a subject drj means there's an arrow + + align:start position:0% +is a subject drj means there's an arrow + + + align:start position:0% +is a subject drj means there's an arrow +that goes from student D to subject + + align:start position:0% +that goes from student D to subject + + + align:start position:0% +that goes from student D to subject +object J and we're collecting the set of + + align:start position:0% +object J and we're collecting the set of + + + align:start position:0% +object J and we're collecting the set of +those JS that start at some D so and + + align:start position:0% +those JS that start at some D so and + + + align:start position:0% +those JS that start at some D so and +arrow from X goes to J is what exists a + + align:start position:0% +arrow from X goes to J is what exists a + + + align:start position:0% +arrow from X goes to J is what exists a +D in X drj means uh written in logic + + align:start position:0% +D in X drj means uh written in logic + + + align:start position:0% +D in X drj means uh written in logic +notation it's really talking about the + + align:start position:0% +notation it's really talking about the + + + align:start position:0% +notation it's really talking about the +end points of arrows and that's a nice + + align:start position:0% +end points of arrows and that's a nice + + + align:start position:0% +end points of arrows and that's a nice +way to think about it but you ought to + + align:start position:0% +way to think about it but you ought to + + + align:start position:0% +way to think about it but you ought to +be able also to retreat to give a nice + + align:start position:0% +be able also to retreat to give a nice + + + align:start position:0% +be able also to retreat to give a nice +crisp set theoretic definition without + + align:start position:0% +crisp set theoretic definition without + + + align:start position:0% +crisp set theoretic definition without +reference to pictures + + align:start position:0% +reference to pictures + + + align:start position:0% +reference to pictures +um if need be so that's an official + + align:start position:0% +um if need be so that's an official + + + align:start position:0% +um if need be so that's an official +definition of the image under + + align:start position:0% +definition of the image under + + + align:start position:0% +definition of the image under +R Let's uh turn now to uh an operation + + align:start position:0% +R Let's uh turn now to uh an operation + + + align:start position:0% +R Let's uh turn now to uh an operation +on relations which converts one relation + + align:start position:0% +on relations which converts one relation + + + align:start position:0% +on relations which converts one relation +into another relation called the inverse + + align:start position:0% +into another relation called the inverse + + + align:start position:0% +into another relation called the inverse +of R and the inverse of R Is What You + + align:start position:0% +of R and the inverse of R Is What You + + + align:start position:0% +of R and the inverse of R Is What You +Get by turning the arrows around so + + align:start position:0% +Get by turning the arrows around so + + + align:start position:0% +Get by turning the arrows around so +let's look at the relation R which is + + align:start position:0% +let's look at the relation R which is + + + align:start position:0% +let's look at the relation R which is +the registered for relation going from D + + align:start position:0% +the registered for relation going from D + + + align:start position:0% +the registered for relation going from D +students to J subjects and then if I + + align:start position:0% +students to J subjects and then if I + + + align:start position:0% +students to J subjects and then if I +look at r inverse R inverse I could + + align:start position:0% +look at r inverse R inverse I could + + + align:start position:0% +look at r inverse R inverse I could +think of as the registers relation 6042 + + align:start position:0% +think of as the registers relation 6042 + + + align:start position:0% +think of as the registers relation 6042 +registers Jason and and 6012 registers + + align:start position:0% +registers Jason and and 6012 registers + + + align:start position:0% +registers Jason and and 6012 registers +Jason and eway it's a funny usage of the + + align:start position:0% +Jason and eway it's a funny usage of the + + + align:start position:0% +Jason and eway it's a funny usage of the +word but I needed something short that + + align:start position:0% +word but I needed something short that + + + align:start position:0% +word but I needed something short that +would fit on the slide so registers is + + align:start position:0% +would fit on the slide so registers is + + + align:start position:0% +would fit on the slide so registers is +basically turning the arrows backwards + + align:start position:0% +basically turning the arrows backwards + + + align:start position:0% +basically turning the arrows backwards +of uh is registered + + align:start position:0% +of uh is registered + + + align:start position:0% +of uh is registered +for and now I can apply the definition + + align:start position:0% +for and now I can apply the definition + + + align:start position:0% +for and now I can apply the definition +of image to our inverse in a useful way + + align:start position:0% +of image to our inverse in a useful way + + + align:start position:0% +of image to our inverse in a useful way +but just to be crisp about what we're + + align:start position:0% +but just to be crisp about what we're + + + align:start position:0% +but just to be crisp about what we're +doing here is formally our inverse is + + align:start position:0% +doing here is formally our inverse is + + + align:start position:0% +doing here is formally our inverse is +gotten by flipping the role of the + + align:start position:0% +gotten by flipping the role of the + + + align:start position:0% +gotten by flipping the role of the +domain and the code domain so we have + + align:start position:0% +domain and the code domain so we have + + + align:start position:0% +domain and the code domain so we have +that drj if and only if J R inverse + + align:start position:0% +that drj if and only if J R inverse + + + align:start position:0% +that drj if and only if J R inverse +D so let's look at R inverse of 6012 + + align:start position:0% +D so let's look at R inverse of 6012 + + + align:start position:0% +D so let's look at R inverse of 6012 +what that's going to mean is all the + + align:start position:0% +what that's going to mean is all the + + + align:start position:0% +what that's going to mean is all the +students that are taking + + align:start position:0% +students that are taking + + + align:start position:0% +students that are taking +6012 so we start off at 6012 and we go + + align:start position:0% +6012 so we start off at 6012 and we go + + + align:start position:0% +6012 so we start off at 6012 and we go +back to all the students that are + + align:start position:0% +back to all the students that are + + + align:start position:0% +back to all the students that are +registered for it it's Jason and eway + + align:start position:0% +registered for it it's Jason and eway + + + align:start position:0% +registered for it it's Jason and eway +again and so R inverse of 6012 is Jason + + align:start position:0% +again and so R inverse of 6012 is Jason + + + align:start position:0% +again and so R inverse of 6012 is Jason +and eay R inverse of 6012 and 63 well + + align:start position:0% +and eay R inverse of 6012 and 63 well + + + align:start position:0% +and eay R inverse of 6012 and 63 well +same deal let's look at + + align:start position:0% +same deal let's look at + + + align:start position:0% +same deal let's look at +63 and 6012 and look at all the students + + align:start position:0% +63 and 6012 and look at all the students + + + align:start position:0% +63 and 6012 and look at all the students +that are registered for either one of + + align:start position:0% +that are registered for either one of + + + align:start position:0% +that are registered for either one of +them now it's Jason Joan and eway shown + + align:start position:0% +them now it's Jason Joan and eway shown + + + align:start position:0% +them now it's Jason Joan and eway shown +by those red arrows those all the arrows + + align:start position:0% +by those red arrows those all the arrows + + + align:start position:0% +by those red arrows those all the arrows +coming out of those two courses 03 and + + align:start position:0% +coming out of those two courses 03 and + + + align:start position:0% +coming out of those two courses 03 and +012 and so our inverse + + align:start position:0% +012 and so our inverse + + + align:start position:0% +012 and so our inverse +of3 and 012 is that set of three + + align:start position:0% +of3 and 012 is that set of three + + + align:start position:0% +of3 and 012 is that set of three +students Jon Joan and + + align:start position:0% +students Jon Joan and + + + align:start position:0% +students Jon Joan and +eway and in general when you start off + + align:start position:0% +eway and in general when you start off + + + align:start position:0% +eway and in general when you start off +with a bunch of subjects a bunch of + + align:start position:0% +with a bunch of subjects a bunch of + + + align:start position:0% +with a bunch of subjects a bunch of +elements of the codomain and you apply R + + align:start position:0% +elements of the codomain and you apply R + + + align:start position:0% +elements of the codomain and you apply R +inverse to it it's called the inverse + + align:start position:0% +inverse to it it's called the inverse + + + align:start position:0% +inverse to it it's called the inverse +image of Y under + + align:start position:0% + + + + align:start position:0% + +R well let's look at the set J of all + + align:start position:0% +R well let's look at the set J of all + + + align:start position:0% +R well let's look at the set J of all +the subjects and think about what is r + + align:start position:0% +the subjects and think about what is r + + + align:start position:0% +the subjects and think about what is r +inverse of J what does it mean well R + + align:start position:0% +inverse of J what does it mean well R + + + align:start position:0% +inverse of J what does it mean well R +inverse of J is all the students that + + align:start position:0% +inverse of J is all the students that + + + align:start position:0% +inverse of J is all the students that +are registered for some subject at + + align:start position:0% +are registered for some subject at + + + align:start position:0% +are registered for some subject at +all um which is a good thing to have so + + align:start position:0% +all um which is a good thing to have so + + + align:start position:0% +all um which is a good thing to have so +now I can start using these sets to make + + align:start position:0% +now I can start using these sets to make + + + align:start position:0% +now I can start using these sets to make +to make assertions about my database + + align:start position:0% +to make assertions about my database + + + align:start position:0% +to make assertions about my database +that can be useful to know so for + + align:start position:0% +that can be useful to know so for + + + align:start position:0% +that can be useful to know so for +example if I want to say that every + + align:start position:0% +example if I want to say that every + + + align:start position:0% +example if I want to say that every +student is registered for some + + align:start position:0% +student is registered for some + + + align:start position:0% +student is registered for some +subject which of course they are uh what + + align:start position:0% +subject which of course they are uh what + + + align:start position:0% +subject which of course they are uh what +I would say is that D the set of all + + align:start position:0% +I would say is that D the set of all + + + align:start position:0% +I would say is that D the set of all +students is a subset of R inverse of J + + align:start position:0% +students is a subset of R inverse of J + + + align:start position:0% +students is a subset of R inverse of J +so this concise set theoretic and uh + + align:start position:0% +so this concise set theoretic and uh + + + align:start position:0% +so this concise set theoretic and uh +containment uh statement D is a subset + + align:start position:0% +containment uh statement D is a subset + + + align:start position:0% +containment uh statement D is a subset +of R inverse of J is a slick way of + + align:start position:0% +of R inverse of J is a slick way of + + + align:start position:0% +of R inverse of J is a slick way of +writing the precise statement that says + + align:start position:0% +writing the precise statement that says + + + align:start position:0% +writing the precise statement that says +that um uh all the students are + + align:start position:0% +that um uh all the students are + + + align:start position:0% +that um uh all the students are +registered for some + + align:start position:0% +registered for some + + + align:start position:0% +registered for some +subject now it happens not to be true by + + align:start position:0% +subject now it happens not to be true by + + + align:start position:0% +subject now it happens not to be true by +the way because if you looked back at + + align:start position:0% +the way because if you looked back at + + + align:start position:0% +the way because if you looked back at +that example Adam was not registered for + + align:start position:0% +that example Adam was not registered for + + + align:start position:0% +that example Adam was not registered for +a subject so we're not claiming that + + align:start position:0% +a subject so we're not claiming that + + + align:start position:0% +a subject so we're not claiming that +this is true but simply that uh there + + align:start position:0% +this is true but simply that uh there + + + align:start position:0% +this is true but simply that uh there +there's a nice way to express it using + + align:start position:0% +there's a nice way to express it using + + + align:start position:0% +there's a nice way to express it using +images and + + align:start position:0% +images and + + + align:start position:0% +images and +containment let's look at a different + + align:start position:0% +containment let's look at a different + + + align:start position:0% +containment let's look at a different +relation that we could call the advisor + + align:start position:0% +relation that we could call the advisor + + + align:start position:0% +relation that we could call the advisor +relation so the advisor relation is + + align:start position:0% +relation so the advisor relation is + + + align:start position:0% +relation so the advisor relation is +going to have co- domain the same set of + + align:start position:0% +going to have co- domain the same set of + + + align:start position:0% +going to have co- domain the same set of +students D but it's going to have as a + + align:start position:0% +students D but it's going to have as a + + + align:start position:0% +students D but it's going to have as a +domain the set of professors and I've + + align:start position:0% +domain the set of professors and I've + + + align:start position:0% +domain the set of professors and I've +written down the initials of five + + align:start position:0% +written down the initials of five + + + align:start position:0% +written down the initials of five +prominent professors uh mine is at the + + align:start position:0% +prominent professors uh mine is at the + + + align:start position:0% +prominent professors uh mine is at the +top and you may recognize some of the + + align:start position:0% +top and you may recognize some of the + + + align:start position:0% +top and you may recognize some of the +others but it doesn't really matter if + + align:start position:0% +others but it doesn't really matter if + + + align:start position:0% +others but it doesn't really matter if +you don't um and the advises Rel V is + + align:start position:0% +you don't um and the advises Rel V is + + + align:start position:0% +you don't um and the advises Rel V is +going to be indicated by those arrows so + + align:start position:0% +going to be indicated by those arrows so + + + align:start position:0% +going to be indicated by those arrows so +in particular it shows that armm is the + + align:start position:0% +in particular it shows that armm is the + + + align:start position:0% +in particular it shows that armm is the +adviser of Jason Joan eway and Adam + + align:start position:0% +adviser of Jason Joan eway and Adam + + + align:start position:0% +adviser of Jason Joan eway and Adam +which he happens to be um FTL is an + + align:start position:0% +which he happens to be um FTL is an + + + align:start position:0% +which he happens to be um FTL is an +advisor of Joan and eway so Joan has two + + align:start position:0% +advisor of Joan and eway so Joan has two + + + align:start position:0% +advisor of Joan and eway so Joan has two +advisor because she's a double major um + + align:start position:0% +advisor because she's a double major um + + + align:start position:0% +advisor because she's a double major um +eway does as well uh and Adam does as + + align:start position:0% +eway does as well uh and Adam does as + + + align:start position:0% +eway does as well uh and Adam does as +well now that I look at this + + align:start position:0% + + + + align:start position:0% + +example so if I look at in particular + + align:start position:0% +example so if I look at in particular + + + align:start position:0% +example so if I look at in particular +now the advisees of FTL or TLP I'm + + align:start position:0% +now the advisees of FTL or TLP I'm + + + align:start position:0% +now the advisees of FTL or TLP I'm +looking at V of the set consisting of + + align:start position:0% +looking at V of the set consisting of + + + align:start position:0% +looking at V of the set consisting of +FTL and TLP and it's going to be Joan + + align:start position:0% +FTL and TLP and it's going to be Joan + + + align:start position:0% +FTL and TLP and it's going to be Joan +eway and Adam so taking the image of FTL + + align:start position:0% +eway and Adam so taking the image of FTL + + + align:start position:0% +eway and Adam so taking the image of FTL +and TLP that that's the set of advisees + + align:start position:0% +and TLP that that's the set of advisees + + + align:start position:0% +and TLP that that's the set of advisees +of either of those two professors I get + + align:start position:0% +of either of those two professors I get + + + align:start position:0% +of either of those two professors I get +this set of three students Joan eway and + + align:start position:0% +this set of three students Joan eway and + + + align:start position:0% +this set of three students Joan eway and +Adam well that's a set of students and + + align:start position:0% +Adam well that's a set of students and + + + align:start position:0% +Adam well that's a set of students and +the registered relation applies to a set + + align:start position:0% +the registered relation applies to a set + + + align:start position:0% +the registered relation applies to a set +of students so let's do that if I now + + align:start position:0% +of students so let's do that if I now + + + align:start position:0% +of students so let's do that if I now +apply R to Joan and eway and Adam what + + align:start position:0% +apply R to Joan and eway and Adam what + + + align:start position:0% +apply R to Joan and eway and Adam what +I'm getting is the subjects that they're + + align:start position:0% +I'm getting is the subjects that they're + + + align:start position:0% +I'm getting is the subjects that they're +registered + + align:start position:0% +registered + + + align:start position:0% +registered +for um so this is called composing r and + + align:start position:0% +for um so this is called composing r and + + + align:start position:0% +for um so this is called composing r and +v I've applied V and then I'm applying R + + align:start position:0% +v I've applied V and then I'm applying R + + + align:start position:0% +v I've applied V and then I'm applying R +to the result in this case um R of V of + + align:start position:0% +to the result in this case um R of V of + + + align:start position:0% +to the result in this case um R of V of +FTL and TLP is the same as R of Joan ehu + + align:start position:0% +FTL and TLP is the same as R of Joan ehu + + + align:start position:0% +FTL and TLP is the same as R of Joan ehu +and atom it's the courses that any of + + align:start position:0% +and atom it's the courses that any of + + + align:start position:0% +and atom it's the courses that any of +them are taken taking and it's 0312 + + align:start position:0% + + + + align:start position:0% + +and4 so the way to understand this R of + + align:start position:0% +and4 so the way to understand this R of + + + align:start position:0% +and4 so the way to understand this R of +v in general is you start off with any + + align:start position:0% +v in general is you start off with any + + + align:start position:0% +v in general is you start off with any +set X of professors in the domain you + + align:start position:0% +set X of professors in the domain you + + + align:start position:0% +set X of professors in the domain you +take V ofx are the uh advisees that they + + align:start position:0% +take V ofx are the uh advisees that they + + + align:start position:0% +take V ofx are the uh advisees that they +have and then you take R of the advisees + + align:start position:0% +have and then you take R of the advisees + + + align:start position:0% +have and then you take R of the advisees +and you get the subjects that the + + align:start position:0% +and you get the subjects that the + + + align:start position:0% +and you get the subjects that the +advises are taken so R of V ofx is the + + align:start position:0% +advises are taken so R of V ofx is the + + + align:start position:0% +advises are taken so R of V ofx is the +subjects that advise es of X are taken + + align:start position:0% +subjects that advise es of X are taken + + + align:start position:0% +subjects that advise es of X are taken +are registered + + align:start position:0% +are registered + + + align:start position:0% +are registered +for well we can abstract that out and + + align:start position:0% +for well we can abstract that out and + + + align:start position:0% +for well we can abstract that out and +call this the composition of r and v + + align:start position:0% +call this the composition of r and v + + + align:start position:0% +call this the composition of r and v +it's defined the same way that + + align:start position:0% +it's defined the same way that + + + align:start position:0% +it's defined the same way that +functional composition is so R of V uh + + align:start position:0% +functional composition is so R of V uh + + + align:start position:0% +functional composition is so R of V uh +is the relation and the images of that + + align:start position:0% +is the relation and the images of that + + + align:start position:0% +is the relation and the images of that +relation the images of a set of + + align:start position:0% +relation the images of a set of + + + align:start position:0% +relation the images of a set of +professors under R of V is defined to be + + align:start position:0% +professors under R of V is defined to be + + + align:start position:0% +professors under R of V is defined to be +apply V to X and then apply R to V of + + align:start position:0% +apply V to X and then apply R to V of + + + align:start position:0% +apply V to X and then apply R to V of +x uh and it's again called the + + align:start position:0% +x uh and it's again called the + + + align:start position:0% +x uh and it's again called the +composition of r and v + + align:start position:0% +composition of r and v + + + align:start position:0% +composition of r and v +what it means now is that two things are + + align:start position:0% +what it means now is that two things are + + + align:start position:0% +what it means now is that two things are +related by R of v it relates professors + + align:start position:0% +related by R of v it relates professors + + + align:start position:0% +related by R of v it relates professors +and subjects and it says that a + + align:start position:0% +and subjects and it says that a + + + align:start position:0% +and subjects and it says that a +professor and a subject are related if + + align:start position:0% +professor and a subject are related if + + + align:start position:0% +professor and a subject are related if +the professor has an advise some advise + + align:start position:0% +the professor has an advise some advise + + + align:start position:0% +the professor has an advise some advise +in that subject P for a professor + + align:start position:0% +in that subject P for a professor + + + align:start position:0% +in that subject P for a professor +composition of r with v j for a subject + + align:start position:0% +composition of r with v j for a subject + + + align:start position:0% +composition of r with v j for a subject +holds if and only if Professor P has an + + align:start position:0% +holds if and only if Professor P has an + + + align:start position:0% +holds if and only if Professor P has an +advise Z registered in subject + + align:start position:0% +advise Z registered in subject + + + align:start position:0% +advise Z registered in subject +J let's see how you figure that kind of + + align:start position:0% +J let's see how you figure that kind of + + + align:start position:0% +J let's see how you figure that kind of +thing out so um I'm going to draw the V + + align:start position:0% +thing out so um I'm going to draw the V + + + align:start position:0% +thing out so um I'm going to draw the V +relation which goes from P professors to + + align:start position:0% +relation which goes from P professors to + + + align:start position:0% +relation which goes from P professors to +D students and then the r relation that + + align:start position:0% +D students and then the r relation that + + + align:start position:0% +D students and then the r relation that +goes from D students to J subjects uh + + align:start position:0% +goes from D students to J subjects uh + + + align:start position:0% +goes from D students to J subjects uh +and by showing them in this way I can + + align:start position:0% +and by showing them in this way I can + + + align:start position:0% +and by showing them in this way I can +understand the composition of r and v as + + align:start position:0% +understand the composition of r and v as + + + align:start position:0% +understand the composition of r and v as +following two arrows you start off say + + align:start position:0% +following two arrows you start off say + + + align:start position:0% +following two arrows you start off say +at armm and you follow a v Arrow from + + align:start position:0% +at armm and you follow a v Arrow from + + + align:start position:0% +at armm and you follow a v Arrow from +armm to his advisor y z + + align:start position:0% +armm to his advisor y z + + + align:start position:0% +armm to his advisor y z +eway then you follow another arrow from + + align:start position:0% +eway then you follow another arrow from + + + align:start position:0% +eway then you follow another arrow from +eway to 6012 and you discover hey armm + + align:start position:0% +eway to 6012 and you discover hey armm + + + align:start position:0% +eway to 6012 and you discover hey armm +has an advise Z in so now we can say + + align:start position:0% +has an advise Z in so now we can say + + + align:start position:0% +has an advise Z in so now we can say +that Professor armm is in the relation R + + align:start position:0% +that Professor armm is in the relation R + + + align:start position:0% +that Professor armm is in the relation R +composed with V with + + align:start position:0% +composed with V with + + + align:start position:0% +composed with V with +6012 because of this path armm has e as + + align:start position:0% +6012 because of this path armm has e as + + + align:start position:0% +6012 because of this path armm has e as +an advise e and eway is registered for + + align:start position:0% +an advise e and eway is registered for + + + align:start position:0% +an advise e and eway is registered for +6012 and this relation r V we figured + + align:start position:0% +6012 and this relation r V we figured + + + align:start position:0% +6012 and this relation r V we figured +out is the relation that the professor + + align:start position:0% +out is the relation that the professor + + + align:start position:0% +out is the relation that the professor +has an advise e in the subject so in + + align:start position:0% +has an advise e in the subject so in + + + align:start position:0% +has an advise e in the subject so in +general what we can say is that a + + align:start position:0% +general what we can say is that a + + + align:start position:0% +general what we can say is that a +professor p is in the ROV relation to J + + align:start position:0% +professor p is in the ROV relation to J + + + align:start position:0% +professor p is in the ROV relation to J +if and only if and here we're going to + + align:start position:0% +if and only if and here we're going to + + + align:start position:0% +if and only if and here we're going to +State it in formal logical notation + + align:start position:0% +State it in formal logical notation + + + align:start position:0% +State it in formal logical notation +which really applies in general not just + + align:start position:0% +which really applies in general not just + + + align:start position:0% +which really applies in general not just +to this particular example so the + + align:start position:0% +to this particular example so the + + + align:start position:0% +to this particular example so the +definition of R composed with v is that + + align:start position:0% +definition of R composed with v is that + + + align:start position:0% +definition of R composed with v is that +p r composed with VJ means there's a d + + align:start position:0% +p r composed with VJ means there's a d + + + align:start position:0% +p r composed with VJ means there's a d +that connects p and J through V and D in + + align:start position:0% +that connects p and J through V and D in + + + align:start position:0% +that connects p and J through V and D in +particular uh that there's a d such that + + align:start position:0% +particular uh that there's a d such that + + + align:start position:0% +particular uh that there's a d such that +PV D which means there's an arrow a v + + align:start position:0% +PV D which means there's an arrow a v + + + align:start position:0% +PV D which means there's an arrow a v +Arrow from P to D and D RJ there's an R + + align:start position:0% +Arrow from P to D and D RJ there's an R + + + align:start position:0% +Arrow from P to D and D RJ there's an R +Arrow from D to J for some + + align:start position:0% +Arrow from D to J for some + + + align:start position:0% +Arrow from D to J for some +d by the way there's a technicality here + + align:start position:0% +d by the way there's a technicality here + + + align:start position:0% +d by the way there's a technicality here +that um when you write the formula uh + + align:start position:0% +that um when you write the formula uh + + + align:start position:0% +that um when you write the formula uh +PVD and + + align:start position:0% +PVD and + + + align:start position:0% +PVD and +drj um following the diagram where you + + align:start position:0% +drj um following the diagram where you + + + align:start position:0% +drj um following the diagram where you +start with V on the left and follow a v + + align:start position:0% +start with V on the left and follow a v + + + align:start position:0% +start with V on the left and follow a v +arrow and then an R Arrow it's natural + + align:start position:0% +arrow and then an R Arrow it's natural + + + align:start position:0% +arrow and then an R Arrow it's natural +to think of them as written in left to + + align:start position:0% +to think of them as written in left to + + + align:start position:0% +to think of them as written in left to +right order of what you apply first VR + + align:start position:0% +right order of what you apply first VR + + + align:start position:0% +right order of what you apply first VR +but of course that's not the way + + align:start position:0% +but of course that's not the way + + + align:start position:0% +but of course that's not the way +composition works when you apply one + + align:start position:0% +composition works when you apply one + + + align:start position:0% +composition works when you apply one +function R to V to something you're + + align:start position:0% +function R to V to something you're + + + align:start position:0% +function R to V to something you're +applying V first and you write it on the + + align:start position:0% +applying V first and you write it on the + + + align:start position:0% +applying V first and you write it on the +right so R oov is written like function + + align:start position:0% +right so R oov is written like function + + + align:start position:0% +right so R oov is written like function +composition where V applies first but + + align:start position:0% +composition where V applies first but + + + align:start position:0% +composition where V applies first but +the logical statement um uh the natural + + align:start position:0% +the logical statement um uh the natural + + + align:start position:0% +the logical statement um uh the natural +way to write it is to follow the way the + + align:start position:0% +way to write it is to follow the way the + + + align:start position:0% +way to write it is to follow the way the +picture works and the v's and rs get + + align:start position:0% +picture works and the v's and rs get + + + align:start position:0% +picture works and the v's and rs get +reversed so watch out for that + + align:start position:0% +reversed so watch out for that + + + align:start position:0% +reversed so watch out for that +confusion well I want to introduce one + + align:start position:0% +confusion well I want to introduce one + + + align:start position:0% +confusion well I want to introduce one +more relation to flesh out this example + + align:start position:0% +more relation to flesh out this example + + + align:start position:0% +more relation to flesh out this example +and that'll be the teach's relation so + + align:start position:0% +and that'll be the teach's relation so + + + align:start position:0% +and that'll be the teach's relation so +the teach's relation is going to have as + + align:start position:0% +the teach's relation is going to have as + + + align:start position:0% +the teach's relation is going to have as +domain professors again uh and as + + align:start position:0% +domain professors again uh and as + + + align:start position:0% +domain professors again uh and as +codomain subjects and it's simply going + + align:start position:0% +codomain subjects and it's simply going + + + align:start position:0% +codomain subjects and it's simply going +to tell us who's teaching what so here + + align:start position:0% +to tell us who's teaching what so here + + + align:start position:0% +to tell us who's teaching what so here +we're going to see that um armm is + + align:start position:0% +we're going to see that um armm is + + + align:start position:0% +we're going to see that um armm is +teaching 6042 as you well know and ft is + + align:start position:0% +teaching 6042 as you well know and ft is + + + align:start position:0% +teaching 6042 as you well know and ft is +teaching 6042 which he does frequently + + align:start position:0% +teaching 6042 which he does frequently + + + align:start position:0% +teaching 6042 which he does frequently +but not this + + align:start position:0% +but not this + + + align:start position:0% +but not this +term um and now I can again use my + + align:start position:0% +term um and now I can again use my + + + align:start position:0% +term um and now I can again use my +relational operators to start making + + align:start position:0% +relational operators to start making + + + align:start position:0% +relational operators to start making +assertions about this about these people + + align:start position:0% +assertions about this about these people + + + align:start position:0% +assertions about this about these people +and relations involving teaching and + + align:start position:0% +and relations involving teaching and + + + align:start position:0% +and relations involving teaching and +advisees so I and the useful way to do + + align:start position:0% +advisees so I and the useful way to do + + + align:start position:0% +advisees so I and the useful way to do +that is by applying set operations to + + align:start position:0% +that is by applying set operations to + + + align:start position:0% +that is by applying set operations to +the + + align:start position:0% +the + + + align:start position:0% +the +relations um because I can think of the + + align:start position:0% +relations um because I can think of the + + + align:start position:0% +relations um because I can think of the +relations as being that set of arrows so + + align:start position:0% +relations as being that set of arrows so + + + align:start position:0% +relations as being that set of arrows so +suppose I wanted to make some statement + + align:start position:0% +suppose I wanted to make some statement + + + align:start position:0% +suppose I wanted to make some statement +that a professor should not teach their + + align:start position:0% +that a professor should not teach their + + + align:start position:0% +that a professor should not teach their +own advise Z because uh it's too much + + align:start position:0% +own advise Z because uh it's too much + + + align:start position:0% +own advise Z because uh it's too much +power for one person to have over a + + align:start position:0% +power for one person to have over a + + + align:start position:0% +power for one person to have over a +student um this is not true by the way + + align:start position:0% +student um this is not true by the way + + + align:start position:0% +student um this is not true by the way +it's common for professors to teach + + align:start position:0% +it's common for professors to teach + + + align:start position:0% +it's common for professors to teach +advises but there are other kinds of + + align:start position:0% +advises but there are other kinds of + + + align:start position:0% +advises but there are other kinds of +rules about uh dual relationships uh + + align:start position:0% +rules about uh dual relationships uh + + + align:start position:0% +rules about uh dual relationships uh +between Su uh supervisory relationships + + align:start position:0% +between Su uh supervisory relationships + + + align:start position:0% +between Su uh supervisory relationships +and personal relationships but anyway + + align:start position:0% +and personal relationships but anyway + + + align:start position:0% +and personal relationships but anyway +let's say if we can say that profs + + align:start position:0% +let's say if we can say that profs + + + align:start position:0% +let's say if we can say that profs +should not supervise or should not teach + + align:start position:0% +should not supervise or should not teach + + + align:start position:0% +should not supervise or should not teach +any one that they're advising well um if + + align:start position:0% +any one that they're advising well um if + + + align:start position:0% +any one that they're advising well um if +we were saying that in logical notation + + align:start position:0% +we were saying that in logical notation + + + align:start position:0% +we were saying that in logical notation +what we would say is that for every + + align:start position:0% +what we would say is that for every + + + align:start position:0% +what we would say is that for every +professor and subject it's not the case + + align:start position:0% +professor and subject it's not the case + + + align:start position:0% +professor and subject it's not the case +that uh the professor has an advise Z in + + align:start position:0% +that uh the professor has an advise Z in + + + align:start position:0% +that uh the professor has an advise Z in +subject J and the professor is teaching + + align:start position:0% +subject J and the professor is teaching + + + align:start position:0% +subject J and the professor is teaching +subject J so that's how you say it in + + align:start position:0% +subject J so that's how you say it in + + + align:start position:0% +subject J so that's how you say it in +logic but there's a very slick way to + + align:start position:0% +logic but there's a very slick way to + + + align:start position:0% +logic but there's a very slick way to +say it without all the formulas in the + + align:start position:0% +say it without all the formulas in the + + + align:start position:0% +say it without all the formulas in the +quantifiers I could just say that t the + + align:start position:0% +quantifiers I could just say that t the + + + align:start position:0% +quantifiers I could just say that t the +relationship of his teaching + + align:start position:0% +relationship of his teaching + + + align:start position:0% +relationship of his teaching +intersected with the relationship of has + + align:start position:0% +intersected with the relationship of has + + + align:start position:0% +intersected with the relationship of has +an advise Z in the subject is empty + + align:start position:0% +an advise Z in the subject is empty + + + align:start position:0% +an advise Z in the subject is empty +there is no pair of Professor and + + align:start position:0% +there is no pair of Professor and + + + align:start position:0% +there is no pair of Professor and +subject that is in both T and in R of v + + align:start position:0% +subject that is in both T and in R of v + + + align:start position:0% +subject that is in both T and in R of v +um and this bottom expression here gives + + align:start position:0% +um and this bottom expression here gives + + + align:start position:0% +um and this bottom expression here gives +you a a sense of the concise way that + + align:start position:0% +you a a sense of the concise way that + + + align:start position:0% +you a a sense of the concise way that +you can express queries and assertions + + align:start position:0% +you can express queries and assertions + + + align:start position:0% +you can express queries and assertions +about the database using a combination + + align:start position:0% +about the database using a combination + + + align:start position:0% +about the database using a combination +of relational operators and set + + align:start position:0% +of relational operators and set + + + align:start position:0% +of relational operators and set +operators another way to say it by the + + align:start position:0% +operators another way to say it by the + + + align:start position:0% +operators another way to say it by the +way this is a general set theoretic fact + + align:start position:0% +way this is a general set theoretic fact + + + align:start position:0% +way this is a general set theoretic fact +is the way to say that T and R of V + + align:start position:0% +is the way to say that T and R of V + + + align:start position:0% +is the way to say that T and R of V +intersected is empty is to say that they + + align:start position:0% +intersected is empty is to say that they + + + align:start position:0% +intersected is empty is to say that they +that the set T and the set R of V + + align:start position:0% +that the set T and the set R of V + + + align:start position:0% +that the set T and the set R of V +whatever they are have no points in + + align:start position:0% +whatever they are have no points in + + + align:start position:0% +whatever they are have no points in +common uh an equivalent way to say that + + align:start position:0% +common uh an equivalent way to say that + + + align:start position:0% +common uh an equivalent way to say that +is that one set is contained in the + + align:start position:0% +is that one set is contained in the + + + align:start position:0% +is that one set is contained in the +complement of the other set so I could + + align:start position:0% +complement of the other set so I could + + + align:start position:0% +complement of the other set so I could +equally well have said this as R + + align:start position:0% +equally well have said this as R + + + align:start position:0% +equally well have said this as R +composed with v is a subset of of not + + align:start position:0% +composed with v is a subset of of not + + + align:start position:0% +composed with v is a subset of of not +t well let's step back now and summarize + + align:start position:0% +t well let's step back now and summarize + + + align:start position:0% +t well let's step back now and summarize +what we've done by example and and say a + + align:start position:0% +what we've done by example and and say a + + + align:start position:0% +what we've done by example and and say a +little bit about what it how it works in + + align:start position:0% +little bit about what it how it works in + + + align:start position:0% +little bit about what it how it works in +general so as I said a binary relation + + align:start position:0% +general so as I said a binary relation + + + align:start position:0% +general so as I said a binary relation +um and we'll start to be slightly more + + align:start position:0% +um and we'll start to be slightly more + + + align:start position:0% +um and we'll start to be slightly more +formal now a binary relation R from a + + align:start position:0% +formal now a binary relation R from a + + + align:start position:0% +formal now a binary relation R from a +set a to a set B Associates elements of + + align:start position:0% +set a to a set B Associates elements of + + + align:start position:0% +set a to a set B Associates elements of +a with elements of B and um there's a + + align:start position:0% +a with elements of B and um there's a + + + align:start position:0% +a with elements of B and um there's a +picture of a general set a called The + + align:start position:0% +picture of a general set a called The + + + align:start position:0% +picture of a general set a called The +Domain and a general set B called the + + align:start position:0% +Domain and a general set B called the + + + align:start position:0% +Domain and a general set B called the +codomain + + align:start position:0% +codomain + + + align:start position:0% +codomain +and R is given by those arrows well what + + align:start position:0% +and R is given by those arrows well what + + + align:start position:0% +and R is given by those arrows well what +exactly are arrows well if you're going + + align:start position:0% +exactly are arrows well if you're going + + + align:start position:0% +exactly are arrows well if you're going +to formalize arrows um the set of them + + align:start position:0% +to formalize arrows um the set of them + + + align:start position:0% +to formalize arrows um the set of them +is What's called the graph of R so + + align:start position:0% +is What's called the graph of R so + + + align:start position:0% +is What's called the graph of R so +technically a relation really has three + + align:start position:0% +technically a relation really has three + + + align:start position:0% +technically a relation really has three +parts it's not to be identified with + + align:start position:0% +parts it's not to be identified with + + + align:start position:0% +parts it's not to be identified with +just its arrows a relation has a domain + + align:start position:0% +just its arrows a relation has a domain + + + align:start position:0% +just its arrows a relation has a domain +and a co-domain and some bunch of arrows + + align:start position:0% +and a co-domain and some bunch of arrows + + + align:start position:0% +and a co-domain and some bunch of arrows +going from the domain to the co- domain + + align:start position:0% +going from the domain to the co- domain + + + align:start position:0% +going from the domain to the co- domain +um uh the arrow can be formalized by + + align:start position:0% +um uh the arrow can be formalized by + + + align:start position:0% +um uh the arrow can be formalized by +saying all that matters about an arrow + + align:start position:0% +saying all that matters about an arrow + + + align:start position:0% +saying all that matters about an arrow +is where it begins and where it ends + + align:start position:0% +is where it begins and where it ends + + + align:start position:0% +is where it begins and where it ends +because it's just designed to reflect an + + align:start position:0% +because it's just designed to reflect an + + + align:start position:0% +because it's just designed to reflect an +association between an element of the + + align:start position:0% +association between an element of the + + + align:start position:0% +association between an element of the +domain and an element of the co-domain + + align:start position:0% +domain and an element of the co-domain + + + align:start position:0% +domain and an element of the co-domain +so technically the arrows are just + + align:start position:0% +so technically the arrows are just + + + align:start position:0% +so technically the arrows are just +ordered pairs and in this case there are + + align:start position:0% +ordered pairs and in this case there are + + + align:start position:0% +ordered pairs and in this case there are +three arrows one from a to B2 and so you + + align:start position:0% +three arrows one from a to B2 and so you + + + align:start position:0% +three arrows one from a to B2 and so you +see at the bottom of the slide um uh an + + align:start position:0% +see at the bottom of the slide um uh an + + + align:start position:0% +see at the bottom of the slide um uh an +ordered pair A1 B2 um another arrow goes + + align:start position:0% +ordered pair A1 B2 um another arrow goes + + + align:start position:0% +ordered pair A1 B2 um another arrow goes +from A1 to B4 so you see the ordered + + align:start position:0% +from A1 to B4 so you see the ordered + + + align:start position:0% +from A1 to B4 so you see the ordered +pair A1 B4 and the final arrow is A3 B4 + + align:start position:0% +pair A1 B4 and the final arrow is A3 B4 + + + align:start position:0% +pair A1 B4 and the final arrow is A3 B4 +and you see that pair so all the + + align:start position:0% +and you see that pair so all the + + + align:start position:0% +and you see that pair so all the +language about arrows is really talking + + align:start position:0% +language about arrows is really talking + + + align:start position:0% +language about arrows is really talking +about ordered pairs um uh it's just that + + align:start position:0% +about ordered pairs um uh it's just that + + + align:start position:0% +about ordered pairs um uh it's just that +the + + align:start position:0% +the + + + align:start position:0% +the +geometric uh Vision uh image of these + + align:start position:0% +geometric uh Vision uh image of these + + + align:start position:0% +geometric uh Vision uh image of these +diagrams with their arrows makes a lot + + align:start position:0% +diagrams with their arrows makes a lot + + + align:start position:0% +diagrams with their arrows makes a lot +of properties much + + align:start position:0% +of properties much + + + align:start position:0% +of properties much +clearer so the range of R is a important + + align:start position:0% +clearer so the range of R is a important + + + align:start position:0% +clearer so the range of R is a important +concept um that comes up regularly and + + align:start position:0% +concept um that comes up regularly and + + + align:start position:0% +concept um that comes up regularly and +tends to be a little confusing for + + align:start position:0% +tends to be a little confusing for + + + align:start position:0% +tends to be a little confusing for +people the range of R is simply the + + align:start position:0% +people the range of R is simply the + + + align:start position:0% +people the range of R is simply the +elements with arrows coming in from + + align:start position:0% +elements with arrows coming in from + + + align:start position:0% +elements with arrows coming in from +R uh it's all of the elements that are + + align:start position:0% +R uh it's all of the elements that are + + + align:start position:0% +R uh it's all of the elements that are +hit by uh an arrow that starts in the + + align:start position:0% +hit by uh an arrow that starts in the + + + align:start position:0% +hit by uh an arrow that starts in the +domain so it's really R of the domain is + + align:start position:0% +domain so it's really R of the domain is + + + align:start position:0% +domain so it's really R of the domain is +the range of R now notice that this is + + align:start position:0% +the range of R now notice that this is + + + align:start position:0% +the range of R now notice that this is +typically not equal to the whole co- + + align:start position:0% +typically not equal to the whole co- + + + align:start position:0% +typically not equal to the whole co- +domain let's look at this example here + + align:start position:0% +domain let's look at this example here + + + align:start position:0% +domain let's look at this example here +the range of R are the hit the points + + align:start position:0% +the range of R are the hit the points + + + align:start position:0% +the range of R are the hit the points +that are hit by elements of a under R + + align:start position:0% +that are hit by elements of a under R + + + align:start position:0% +that are hit by elements of a under R +namely just B2 and + + align:start position:0% +namely just B2 and + + + align:start position:0% +namely just B2 and +B4 uh the co- domain has elements B1 and + + align:start position:0% +B4 uh the co- domain has elements B1 and + + + align:start position:0% +B4 uh the co- domain has elements B1 and +B3 that are missing and that are not in + + align:start position:0% +B3 that are missing and that are not in + + + align:start position:0% +B3 that are missing and that are not in +the + + align:start position:0% +the + + + align:start position:0% +the +range well as I said functions are a + + align:start position:0% +range well as I said functions are a + + + align:start position:0% +range well as I said functions are a +special case of relation so let's just + + align:start position:0% +special case of relation so let's just + + + align:start position:0% +special case of relation so let's just +look at that um a function uh F from a + + align:start position:0% +look at that um a function uh F from a + + + align:start position:0% +look at that um a function uh F from a +set a to a set B is a relation which + + align:start position:0% +set a to a set B is a relation which + + + align:start position:0% +set a to a set B is a relation which +Associates with each element in the + + align:start position:0% +Associates with each element in the + + + align:start position:0% +Associates with each element in the +domain each element little a in the + + align:start position:0% +domain each element little a in the + + + align:start position:0% +domain each element little a in the +domain capital A with most one element + + align:start position:0% +domain capital A with most one element + + + align:start position:0% +domain capital A with most one element +of the codomain + + align:start position:0% +of the codomain + + + align:start position:0% +of the codomain +B so this one element if it exists is + + align:start position:0% +B so this one element if it exists is + + + align:start position:0% +B so this one element if it exists is +called f of a it's the image of the + + align:start position:0% +called f of a it's the image of the + + + align:start position:0% +called f of a it's the image of the +element a under the relation F but + + align:start position:0% +element a under the relation F but + + + align:start position:0% +element a under the relation F but +what's special about it is that F of a + + align:start position:0% +what's special about it is that F of a + + + align:start position:0% +what's special about it is that F of a +contains at most one element so let's + + align:start position:0% +contains at most one element so let's + + + align:start position:0% +contains at most one element so let's +just look at an example again um a way + + align:start position:0% +just look at an example again um a way + + + align:start position:0% +just look at an example again um a way +to say that that a relation is a + + align:start position:0% +to say that that a relation is a + + + align:start position:0% +to say that that a relation is a +function is to look at all of the points + + align:start position:0% +function is to look at all of the points + + + align:start position:0% +function is to look at all of the points +on the left in the in the domain and + + align:start position:0% +on the left in the in the domain and + + + align:start position:0% +on the left in the in the domain and +make sure that none of them have more + + align:start position:0% +make sure that none of them have more + + + align:start position:0% +make sure that none of them have more +than one Arrow coming out well in this + + align:start position:0% +than one Arrow coming out well in this + + + align:start position:0% +than one Arrow coming out well in this +picture there are a couple of violations + + align:start position:0% +picture there are a couple of violations + + + align:start position:0% +picture there are a couple of violations +about that of that there are a couple of + + align:start position:0% +about that of that there are a couple of + + + align:start position:0% +about that of that there are a couple of +points on the left in a that have more + + align:start position:0% +points on the left in a that have more + + + align:start position:0% +points on the left in a that have more +than one Arrow coming out there's are + + align:start position:0% +than one Arrow coming out there's are + + + align:start position:0% +than one Arrow coming out there's are +two bad edges but if I erase those now + + align:start position:0% +two bad edges but if I erase those now + + + align:start position:0% +two bad edges but if I erase those now +I'm left with a function and sure enough + + align:start position:0% +I'm left with a function and sure enough + + + align:start position:0% +I'm left with a function and sure enough +there's at most one Arrow coming out of + + align:start position:0% +there's at most one Arrow coming out of + + + align:start position:0% +there's at most one Arrow coming out of +each of the points on the left in a some + + align:start position:0% +each of the points on the left in a some + + + align:start position:0% +each of the points on the left in a some +of the points have no arrows coming out + + align:start position:0% +of the points have no arrows coming out + + + align:start position:0% +of the points have no arrows coming out +that's fine um and so so for those green + + align:start position:0% +that's fine um and so so for those green + + + align:start position:0% +that's fine um and so so for those green +points with an arrow out there's a + + align:start position:0% +points with an arrow out there's a + + + align:start position:0% +points with an arrow out there's a +unique F of the Green Point equal to a + + align:start position:0% +unique F of the Green Point equal to a + + + align:start position:0% +unique F of the Green Point equal to a +magenta point in B that's uniquely + + align:start position:0% +magenta point in B that's uniquely + + + align:start position:0% +magenta point in B that's uniquely +determined by the functional relation F + + align:start position:0% +determined by the functional relation F + + + align:start position:0% +determined by the functional relation F +which may not be defined for all of the + + align:start position:0% +which may not be defined for all of the + + + align:start position:0% +which may not be defined for all of the +green points if they don't have any + + align:start position:0% +green points if they don't have any + + + align:start position:0% +green points if they don't have any +Arrow coming out of them so function + + align:start position:0% +Arrow coming out of them so function + + + align:start position:0% +Arrow coming out of them so function +means less than or equal to one Arrow + + align:start position:0% +means less than or equal to one Arrow + + + align:start position:0% +means less than or equal to one Arrow +coming + + align:start position:0% +coming + + + align:start position:0% +coming +out um so if we said this formally + + align:start position:0% +out um so if we said this formally + + + align:start position:0% +out um so if we said this formally +without talking about the arrows one way + + align:start position:0% +without talking about the arrows one way + + + align:start position:0% +without talking about the arrows one way +is simply to say that uh that a relation + + align:start position:0% +is simply to say that uh that a relation + + + align:start position:0% +is simply to say that uh that a relation +is a function if F of little a is if the + + align:start position:0% +is a function if F of little a is if the + + + align:start position:0% +is a function if F of little a is if the +size of f of little a is less than or + + align:start position:0% +size of f of little a is less than or + + + align:start position:0% +size of f of little a is less than or +equal to one for all of the domain + + align:start position:0% +equal to one for all of the domain + + + align:start position:0% +equal to one for all of the domain +elements a um and a more Elementary way + + align:start position:0% +elements a um and a more Elementary way + + + align:start position:0% +elements a um and a more Elementary way +to say it um using just the language of + + align:start position:0% +to say it um using just the language of + + + align:start position:0% +to say it um using just the language of +relations and equality and buole and + + align:start position:0% +relations and equality and buole and + + + align:start position:0% +relations and equality and buole and +connectives is to say that if a is + + align:start position:0% +connectives is to say that if a is + + + align:start position:0% +connectives is to say that if a is +connected to two things by f if AF FB + + align:start position:0% +connected to two things by f if AF FB + + + align:start position:0% +connected to two things by f if AF FB +and AF FB Prime then in fact B is equal + + align:start position:0% +and AF FB Prime then in fact B is equal + + + align:start position:0% +and AF FB Prime then in fact B is equal +to B + + align:start position:0% +to B + + + align:start position:0% +to B +Prime and that wraps up functions \ No newline at end of file diff --git a/Fo8v7juSgRw.txt b/Fo8v7juSgRw.txt new file mode 100644 index 0000000000000000000000000000000000000000..9f77d9e6ad98ac7e285c067c85e4f95b40fe7b81 --- /dev/null +++ b/Fo8v7juSgRw.txt @@ -0,0 +1,20455 @@ +align:start position:0% + +welcome everybody um we + + align:start position:0% +welcome everybody um we + + + align:start position:0% +welcome everybody um we +are extremely fortunate and proud to + + align:start position:0% +are extremely fortunate and proud to + + + align:start position:0% +are extremely fortunate and proud to +have with us today Christopher craft + + align:start position:0% +have with us today Christopher craft + + + align:start position:0% +have with us today Christopher craft +actually Christopher craft Jr he told us + + align:start position:0% +actually Christopher craft Jr he told us + + + align:start position:0% +actually Christopher craft Jr he told us +last night that his father Christopher + + align:start position:0% +last night that his father Christopher + + + align:start position:0% +last night that his father Christopher +craft was born within about a block of + + align:start position:0% +craft was born within about a block of + + + align:start position:0% +craft was born within about a block of +Columbus Circle and that's how he picked + + align:start position:0% +Columbus Circle and that's how he picked + + + align:start position:0% +Columbus Circle and that's how he picked +up the name Christopher Columbus craft + + align:start position:0% +up the name Christopher Columbus craft + + + align:start position:0% +up the name Christopher Columbus craft +which was passed on to Chris Craft Jr um + + align:start position:0% +which was passed on to Chris Craft Jr um + + + align:start position:0% +which was passed on to Chris Craft Jr um +I don't really need to say very much by + + align:start position:0% +I don't really need to say very much by + + + align:start position:0% +I don't really need to say very much by +means of uh introduction because Chris + + align:start position:0% +means of uh introduction because Chris + + + align:start position:0% +means of uh introduction because Chris +Craft is a name that has been associated + + align:start position:0% +Craft is a name that has been associated + + + align:start position:0% +Craft is a name that has been associated +with America's Space Program since the + + align:start position:0% +with America's Space Program since the + + + align:start position:0% +with America's Space Program since the +very + + align:start position:0% +very + + + align:start position:0% +very +beginning uh and actually from the very + + align:start position:0% +beginning uh and actually from the very + + + align:start position:0% +beginning uh and actually from the very +beginning of his career right after he + + align:start position:0% +beginning of his career right after he + + + align:start position:0% +beginning of his career right after he +uh graduated from um university in + + align:start position:0% +uh graduated from um university in + + + align:start position:0% +uh graduated from um university in +Virginia he went to work for the old + + align:start position:0% +Virginia he went to work for the old + + + align:start position:0% +Virginia he went to work for the old +nacka the national uh Commission on a + + align:start position:0% +nacka the national uh Commission on a + + + align:start position:0% +nacka the national uh Commission on a +itics and that of course became + + align:start position:0% +itics and that of course became + + + align:start position:0% +itics and that of course became +eventually NASA so Chris Craft is a + + align:start position:0% +eventually NASA so Chris Craft is a + + + align:start position:0% +eventually NASA so Chris Craft is a +person who has grown up uh with the + + align:start position:0% +person who has grown up uh with the + + + align:start position:0% +person who has grown up uh with the +space program and in fact uh was + + align:start position:0% +space program and in fact uh was + + + align:start position:0% +space program and in fact uh was +responsible for making the Space Program + + align:start position:0% +responsible for making the Space Program + + + align:start position:0% +responsible for making the Space Program +grow up he was instrumental essentially + + align:start position:0% +grow up he was instrumental essentially + + + align:start position:0% +grow up he was instrumental essentially +in inventing the concept of Mission + + align:start position:0% +in inventing the concept of Mission + + + align:start position:0% +in inventing the concept of Mission +Control and uh became after being a + + align:start position:0% +Control and uh became after being a + + + align:start position:0% +Control and uh became after being a +flight director for some of the early + + align:start position:0% +flight director for some of the early + + + align:start position:0% +flight director for some of the early +flights became the head of uh flight + + align:start position:0% +flights became the head of uh flight + + + align:start position:0% +flights became the head of uh flight +operations and eventually the director + + align:start position:0% +operations and eventually the director + + + align:start position:0% +operations and eventually the director +of the Johnson Space Center uh which is + + align:start position:0% +of the Johnson Space Center uh which is + + + align:start position:0% +of the Johnson Space Center uh which is +the home of human space flight in this + + align:start position:0% +the home of human space flight in this + + + align:start position:0% +the home of human space flight in this +country he uh had that position through + + align:start position:0% +country he uh had that position through + + + align:start position:0% +country he uh had that position through +1982 which was the uh the end of the uh + + align:start position:0% +1982 which was the uh the end of the uh + + + align:start position:0% +1982 which was the uh the end of the uh +original orbital flight test phase of + + align:start position:0% +original orbital flight test phase of + + + align:start position:0% +original orbital flight test phase of +the Orbiter so he really was uh in + + align:start position:0% +the Orbiter so he really was uh in + + + align:start position:0% +the Orbiter so he really was uh in +charge of the Space Center when the + + align:start position:0% +charge of the Space Center when the + + + align:start position:0% +charge of the Space Center when the +space shuttle was being developed and of + + align:start position:0% +space shuttle was being developed and of + + + align:start position:0% +space shuttle was being developed and of +course this uh this course is a course + + align:start position:0% +course this uh this course is a course + + + align:start position:0% +course this uh this course is a course +in the systems engineering of the Space + + align:start position:0% +in the systems engineering of the Space + + + align:start position:0% +in the systems engineering of the Space +Shuttle um I just want uh in in public + + align:start position:0% +Shuttle um I just want uh in in public + + + align:start position:0% +Shuttle um I just want uh in in public +here to acknowledge uh that there have + + align:start position:0% +here to acknowledge uh that there have + + + align:start position:0% +here to acknowledge uh that there have +been uh expenses involved in bringing + + align:start position:0% +been uh expenses involved in bringing + + + align:start position:0% +been uh expenses involved in bringing +all of the special lectures that we've + + align:start position:0% +all of the special lectures that we've + + + align:start position:0% +all of the special lectures that we've +had who have participated in this course + + align:start position:0% +had who have participated in this course + + + align:start position:0% +had who have participated in this course +and it would not have been possible + + align:start position:0% +and it would not have been possible + + + align:start position:0% +and it would not have been possible +without the support of the rper + + align:start position:0% +without the support of the rper + + + align:start position:0% +without the support of the rper +laboratory and we thank Dr Ellie guy who + + align:start position:0% +laboratory and we thank Dr Ellie guy who + + + align:start position:0% +laboratory and we thank Dr Ellie guy who +uh has provided that support we we + + align:start position:0% +uh has provided that support we we + + + align:start position:0% +uh has provided that support we we +couldn't have done it without you and we + + align:start position:0% +couldn't have done it without you and we + + + align:start position:0% +couldn't have done it without you and we +really appreciate it that's enough for + + align:start position:0% +really appreciate it that's enough for + + + align:start position:0% +really appreciate it that's enough for +me uh we all came here to hear Chris + + align:start position:0% +me uh we all came here to hear Chris + + + align:start position:0% +me uh we all came here to hear Chris +Kraft talk about uh the development + + align:start position:0% +Kraft talk about uh the development + + + align:start position:0% +Kraft talk about uh the development +invention and development of Mission + + align:start position:0% +invention and development of Mission + + + align:start position:0% +invention and development of Mission +Control and the uh systems engineering + + align:start position:0% +Control and the uh systems engineering + + + align:start position:0% +Control and the uh systems engineering +and development of the Space Shuttle I + + align:start position:0% +and development of the Space Shuttle I + + + align:start position:0% +and development of the Space Shuttle I +will tell you that uh Chris Craft is + + align:start position:0% +will tell you that uh Chris Craft is + + + align:start position:0% +will tell you that uh Chris Craft is +somebody who's not afraid to express his + + align:start position:0% +somebody who's not afraid to express his + + + align:start position:0% +somebody who's not afraid to express his +opinion I and we're looking forward to + + align:start position:0% +opinion I and we're looking forward to + + + align:start position:0% +opinion I and we're looking forward to +hearing them + + align:start position:0% + + + + align:start position:0% + +Chris good + + align:start position:0% +Chris good + + + align:start position:0% +Chris good +morning + + align:start position:0% +morning + + + align:start position:0% +morning +uh it's + + align:start position:0% +uh it's + + + align:start position:0% +uh it's +it's not hard but uh sometimes difficult + + align:start position:0% +it's not hard but uh sometimes difficult + + + align:start position:0% +it's not hard but uh sometimes difficult +to uh return to uh MIT where + + align:start position:0% +to uh return to uh MIT where + + + align:start position:0% +to uh return to uh MIT where +I uh have a lot of friends who came this + + align:start position:0% +I uh have a lot of friends who came this + + + align:start position:0% +I uh have a lot of friends who came this +morning + + align:start position:0% +morning + + + align:start position:0% +morning +uh they they sort of overwhelmed me then + + align:start position:0% +uh they they sort of overwhelmed me then + + + align:start position:0% +uh they they sort of overwhelmed me then +and uh I'm sure they would overwhelm me + + align:start position:0% +and uh I'm sure they would overwhelm me + + + align:start position:0% +and uh I'm sure they would overwhelm me +now if uh we got into some deep + + align:start position:0% +now if uh we got into some deep + + + align:start position:0% +now if uh we got into some deep +technical subject about which I knew + + align:start position:0% +technical subject about which I knew + + + align:start position:0% +technical subject about which I knew +very + + align:start position:0% +very + + + align:start position:0% +very +little at the time uh I'll say a little + + align:start position:0% +little at the time uh I'll say a little + + + align:start position:0% +little at the time uh I'll say a little +bit more about that what I what I did + + align:start position:0% +bit more about that what I what I did + + + align:start position:0% +bit more about that what I what I did +want to say though + + align:start position:0% +want to say though + + + align:start position:0% +want to say though +that uh the people that preceded me in + + align:start position:0% +that uh the people that preceded me in + + + align:start position:0% +that uh the people that preceded me in +lecturing to + + align:start position:0% +lecturing to + + + align:start position:0% +lecturing to +you uh you've been very fortunate + + align:start position:0% +you uh you've been very fortunate + + + align:start position:0% +you uh you've been very fortunate +because uh uh they indeed are uh the + + align:start position:0% +because uh uh they indeed are uh the + + + align:start position:0% +because uh uh they indeed are uh the +stars of the Space Shuttle they did a + + align:start position:0% +stars of the Space Shuttle they did a + + + align:start position:0% +stars of the Space Shuttle they did a +fantastic job and I hope you got that + + align:start position:0% +fantastic job and I hope you got that + + + align:start position:0% +fantastic job and I hope you got that +sense from them as they spoke to you + + align:start position:0% +sense from them as they spoke to you + + + align:start position:0% +sense from them as they spoke to you +they are the best and if uh if I were if + + align:start position:0% +they are the best and if uh if I were if + + + align:start position:0% +they are the best and if uh if I were if +I were going to say two things about U + + align:start position:0% +I were going to say two things about U + + + align:start position:0% +I were going to say two things about U +management that I have learned in my + + align:start position:0% +management that I have learned in my + + + align:start position:0% +management that I have learned in my +lifetime uh the first would be uh you're + + align:start position:0% +lifetime uh the first would be uh you're + + + align:start position:0% +lifetime uh the first would be uh you're +absolutely no better than the people + + align:start position:0% +absolutely no better than the people + + + align:start position:0% +absolutely no better than the people +around you + + align:start position:0% +around you + + + align:start position:0% +around you +without uh a lot of great brains around + + align:start position:0% +without uh a lot of great brains around + + + align:start position:0% +without uh a lot of great brains around +you you're not very good no matter if + + align:start position:0% +you you're not very good no matter if + + + align:start position:0% +you you're not very good no matter if +you're the best person in the world and + + align:start position:0% +you're the best person in the world and + + + align:start position:0% +you're the best person in the world and +too many people have learned that the + + align:start position:0% +too many people have learned that the + + + align:start position:0% +too many people have learned that the +hard way and not recognize that fact + + align:start position:0% +hard way and not recognize that fact + + + align:start position:0% +hard way and not recognize that fact +second thing we talked about last night + + align:start position:0% +second thing we talked about last night + + + align:start position:0% +second thing we talked about last night +around + + align:start position:0% +around + + + align:start position:0% +around +dinner and that was uh the second thing + + align:start position:0% +dinner and that was uh the second thing + + + align:start position:0% +dinner and that was uh the second thing +you learn as a engineering manager + + align:start position:0% +you learn as a engineering manager + + + align:start position:0% +you learn as a engineering manager +is that it every day is a compromise + + align:start position:0% + + + + align:start position:0% + +uh everything you do you you have this + + align:start position:0% +uh everything you do you you have this + + + align:start position:0% +uh everything you do you you have this +idealistic view of doing it the best way + + align:start position:0% +idealistic view of doing it the best way + + + align:start position:0% +idealistic view of doing it the best way +possible doing it better every day doing + + align:start position:0% +possible doing it better every day doing + + + align:start position:0% +possible doing it better every day doing +it uh without worrying too much about + + align:start position:0% +it uh without worrying too much about + + + align:start position:0% +it uh without worrying too much about +the cost too much about the + + align:start position:0% +the cost too much about the + + + align:start position:0% +the cost too much about the +budget too much about the schedule uh + + align:start position:0% +budget too much about the schedule uh + + + align:start position:0% +budget too much about the schedule uh +you go in with that idea but those + + align:start position:0% +you go in with that idea but those + + + align:start position:0% +you go in with that idea but those +things you have to face every day and so + + align:start position:0% +things you have to face every day and so + + + align:start position:0% +things you have to face every day and so +managers has become great + + align:start position:0% +managers has become great + + + align:start position:0% +managers has become great +compromisers and the systems you end up + + align:start position:0% +compromisers and the systems you end up + + + align:start position:0% +compromisers and the systems you end up +with are not what you really + + align:start position:0% +with are not what you really + + + align:start position:0% +with are not what you really +wanted but if you're smart they do the + + align:start position:0% +wanted but if you're smart they do the + + + align:start position:0% +wanted but if you're smart they do the +job so if I were going to add two things + + align:start position:0% +job so if I were going to add two things + + + align:start position:0% +job so if I were going to add two things +to your education at MIT that's where I + + align:start position:0% +to your education at MIT that's where I + + + align:start position:0% +to your education at MIT that's where I +would come + + align:start position:0% +would come + + + align:start position:0% +would come +from uh the third thing I would say is + + align:start position:0% +from uh the third thing I would say is + + + align:start position:0% +from uh the third thing I would say is +that whether you like it or not you + + align:start position:0% +that whether you like it or not you + + + align:start position:0% +that whether you like it or not you +people sitting here not you oldheads + + align:start position:0% +people sitting here not you oldheads + + + align:start position:0% +people sitting here not you oldheads +but you people sitting here are the + + align:start position:0% +but you people sitting here are the + + + align:start position:0% +but you people sitting here are the +people that are going to do the next + + align:start position:0% +people that are going to do the next + + + align:start position:0% +people that are going to do the next +Space + + align:start position:0% +Space + + + align:start position:0% +Space +Program you are the ones that are going + + align:start position:0% +Program you are the ones that are going + + + align:start position:0% +Program you are the ones that are going +to take us back to the Moon if and when + + align:start position:0% +to take us back to the Moon if and when + + + align:start position:0% +to take us back to the Moon if and when +we get there it's going to be up to you + + align:start position:0% +we get there it's going to be up to you + + + align:start position:0% +we get there it's going to be up to you +to do the + + align:start position:0% +to do the + + + align:start position:0% +to do the +job uh in + + align:start position:0% +job uh in + + + align:start position:0% +job uh in +1968 the average age of my organization + + align:start position:0% +1968 the average age of my organization + + + align:start position:0% +1968 the average age of my organization +and I think I was 44 was + + align:start position:0% +and I think I was 44 was + + + align:start position:0% +and I think I was 44 was +26 so we + + align:start position:0% +26 so we + + + align:start position:0% +26 so we +had an awful lot of young people who did + + align:start position:0% +had an awful lot of young people who did + + + align:start position:0% +had an awful lot of young people who did +the job and did it extremely + + align:start position:0% +the job and did it extremely + + + align:start position:0% +the job and did it extremely +well uh the guy sitting there on Apollo + + align:start position:0% +well uh the guy sitting there on Apollo + + + align:start position:0% +well uh the guy sitting there on Apollo +11 uh screaming into them into his + + align:start position:0% +11 uh screaming into them into his + + + align:start position:0% +11 uh screaming into them into his +headset that it was still go I think was + + align:start position:0% +headset that it was still go I think was + + + align:start position:0% +headset that it was still go I think was +25 years old at the time and he was a + + align:start position:0% + + + + align:start position:0% + +veteran and if he hadn't been a veteran + + align:start position:0% +veteran and if he hadn't been a veteran + + + align:start position:0% +veteran and if he hadn't been a veteran +he sure in hell was + + align:start position:0% +he sure in hell was + + + align:start position:0% +he sure in hell was +a few minutes after he kept yelling into + + align:start position:0% +a few minutes after he kept yelling into + + + align:start position:0% +a few minutes after he kept yelling into +that microphone that it was go and if + + align:start position:0% +that microphone that it was go and if + + + align:start position:0% +that microphone that it was go and if +you I hope you've seen that on + + align:start position:0% +you I hope you've seen that on + + + align:start position:0% +you I hope you've seen that on +television if you haven't it's a really + + align:start position:0% +television if you haven't it's a really + + + align:start position:0% +television if you haven't it's a really +great moment in + + align:start position:0% +great moment in + + + align:start position:0% +great moment in +Apollo uh let me start from + + align:start position:0% +Apollo uh let me start from + + + align:start position:0% +Apollo uh let me start from +uh the + + align:start position:0% +uh the + + + align:start position:0% +uh the +beginning uh in Project + + align:start position:0% +beginning uh in Project + + + align:start position:0% +beginning uh in Project +Mercury uh we started with a space task + + align:start position:0% +Mercury uh we started with a space task + + + align:start position:0% +Mercury uh we started with a space task +group of 35 people eight of which were + + align:start position:0% +group of 35 people eight of which were + + + align:start position:0% +group of 35 people eight of which were +secretaries and those of us that came + + align:start position:0% +secretaries and those of us that came + + + align:start position:0% +secretaries and those of us that came +out of the NACA the National advisory + + align:start position:0% +out of the NACA the National advisory + + + align:start position:0% +out of the NACA the National advisory +committee for + + align:start position:0% +committee for + + + align:start position:0% +committee for +Aeronautics uh was um where we were + + align:start position:0% +Aeronautics uh was um where we were + + + align:start position:0% +Aeronautics uh was um where we were +smart guys we were very capable people + + align:start position:0% +smart guys we were very capable people + + + align:start position:0% +smart guys we were very capable people +but we didn't know a damn thing about + + align:start position:0% +but we didn't know a damn thing about + + + align:start position:0% +but we didn't know a damn thing about +how to fly in space believe me if you + + align:start position:0% +how to fly in space believe me if you + + + align:start position:0% +how to fly in space believe me if you +had asked us at the time how do you get + + align:start position:0% +had asked us at the time how do you get + + + align:start position:0% +had asked us at the time how do you get +fluid out of a tank at zero + + align:start position:0% +fluid out of a tank at zero + + + align:start position:0% +fluid out of a tank at zero +g i don't believe you'd gotten the right + + align:start position:0% +g i don't believe you'd gotten the right + + + align:start position:0% +g i don't believe you'd gotten the right +answer from more than two guys maybe Max + + align:start position:0% +answer from more than two guys maybe Max + + + align:start position:0% +answer from more than two guys maybe Max +V would have said well you got to put a + + align:start position:0% +V would have said well you got to put a + + + align:start position:0% +V would have said well you got to put a +bladder in there and put pressure behind + + align:start position:0% +bladder in there and put pressure behind + + + align:start position:0% +bladder in there and put pressure behind +it and squeeze the stuff out because + + align:start position:0% +it and squeeze the stuff out because + + + align:start position:0% +it and squeeze the stuff out because +when we Flo it you don't know where it + + align:start position:0% +when we Flo it you don't know where it + + + align:start position:0% +when we Flo it you don't know where it +is in the tank and secondly how much + + align:start position:0% +is in the tank and secondly how much + + + align:start position:0% +is in the tank and secondly how much +have you got + + align:start position:0% +have you got + + + align:start position:0% +have you got +left in a tank kind of an interesting + + align:start position:0% +left in a tank kind of an interesting + + + align:start position:0% +left in a tank kind of an interesting +project if you don't know what Zer G is + + align:start position:0% +project if you don't know what Zer G is + + + align:start position:0% +project if you don't know what Zer G is +all about so when we + + align:start position:0% +all about so when we + + + align:start position:0% +all about so when we +started in Project Mercury we didn't + + align:start position:0% +started in Project Mercury we didn't + + + align:start position:0% +started in Project Mercury we didn't +know much about systems designed for + + align:start position:0% +know much about systems designed for + + + align:start position:0% +know much about systems designed for +space we certainly had high questions + + align:start position:0% +space we certainly had high questions + + + align:start position:0% +space we certainly had high questions +about man capability to perform a task + + align:start position:0% +about man capability to perform a task + + + align:start position:0% +about man capability to perform a task +in space and I'd say 98 to 99% of the + + align:start position:0% +in space and I'd say 98 to 99% of the + + + align:start position:0% +in space and I'd say 98 to 99% of the +medical community in the United States + + align:start position:0% +medical community in the United States + + + align:start position:0% +medical community in the United States +thought that the astronaut when he got + + align:start position:0% +thought that the astronaut when he got + + + align:start position:0% +thought that the astronaut when he got +there would be a blithering + + align:start position:0% +there would be a blithering + + + align:start position:0% +there would be a blithering +idiot that he would probably swallow his + + align:start position:0% +idiot that he would probably swallow his + + + align:start position:0% +idiot that he would probably swallow his +tongue that he couldn't see because his + + align:start position:0% +tongue that he couldn't see because his + + + align:start position:0% +tongue that he couldn't see because his +eyeballs were bulging at it or that + + align:start position:0% +eyeballs were bulging at it or that + + + align:start position:0% +eyeballs were bulging at it or that +because of the worry he was going + + align:start position:0% +because of the worry he was going + + + align:start position:0% +because of the worry he was going +through he would have a 24 24hour ulcer + + align:start position:0% +through he would have a 24 24hour ulcer + + + align:start position:0% +through he would have a 24 24hour ulcer +sitting on the pad and he and they would + + align:start position:0% +sitting on the pad and he and they would + + + align:start position:0% +sitting on the pad and he and they would +suddenly have to be at his side the + + align:start position:0% +suddenly have to be at his side the + + + align:start position:0% +suddenly have to be at his side the +medical community thought so that's + + align:start position:0% +medical community thought so that's + + + align:start position:0% +medical community thought so that's +where we were coming + + align:start position:0% +where we were coming + + + align:start position:0% +where we were coming +from + + align:start position:0% +from + + + align:start position:0% +from +and so we decided we're going to put man + + align:start position:0% +and so we decided we're going to put man + + + align:start position:0% +and so we decided we're going to put man +in space and thank you very + + align:start position:0% +in space and thank you very + + + align:start position:0% +in space and thank you very +much uh it was a daunting task but one + + align:start position:0% +much uh it was a daunting task but one + + + align:start position:0% +much uh it was a daunting task but one +which most of us realized from the getg + + align:start position:0% +which most of us realized from the getg + + + align:start position:0% +which most of us realized from the getg +go that we were in the middle of + + align:start position:0% +go that we were in the middle of + + + align:start position:0% +go that we were in the middle of +probably man's Greatest + + align:start position:0% +probably man's Greatest + + + align:start position:0% +probably man's Greatest +Adventure believe me we did know that I + + align:start position:0% +Adventure believe me we did know that I + + + align:start position:0% +Adventure believe me we did know that I +felt it and I think everybody felt it it + + align:start position:0% +felt it and I think everybody felt it it + + + align:start position:0% +felt it and I think everybody felt it it +was a it was sort of a uh + + align:start position:0% +was a it was sort of a uh + + + align:start position:0% +was a it was sort of a uh +Euphoria and in we were in what you + + align:start position:0% +Euphoria and in we were in what you + + + align:start position:0% +Euphoria and in we were in what you +would might call engineering Euphoria + + align:start position:0% +would might call engineering Euphoria + + + align:start position:0% +would might call engineering Euphoria +like Ed White was on GED 4 he was + + align:start position:0% +like Ed White was on GED 4 he was + + + align:start position:0% +like Ed White was on GED 4 he was +certain when he was outside the + + align:start position:0% +certain when he was outside the + + + align:start position:0% +certain when he was outside the +spacecraft I'm absolutely certain he was + + align:start position:0% +spacecraft I'm absolutely certain he was + + + align:start position:0% +spacecraft I'm absolutely certain he was +euphoric the Press that he must have + + align:start position:0% +euphoric the Press that he must have + + + align:start position:0% +euphoric the Press that he must have +been euphoric and I said oh no he was + + align:start position:0% +been euphoric and I said oh no he was + + + align:start position:0% +been euphoric and I said oh no he was +worried about what doing the right + + align:start position:0% +worried about what doing the right + + + align:start position:0% +worried about what doing the right +things and doing all the right things at + + align:start position:0% +things and doing all the right things at + + + align:start position:0% +things and doing all the right things at +the right time he was + + align:start position:0% + + + + align:start position:0% + +euphoric again and if you you don't + + align:start position:0% +euphoric again and if you you don't + + + align:start position:0% +euphoric again and if you you don't +recall but they said something finally + + align:start position:0% +recall but they said something finally + + + align:start position:0% +recall but they said something finally +at the end of that and said what does + + align:start position:0% +at the end of that and said what does + + + align:start position:0% +at the end of that and said what does +the flight director have to say and I + + align:start position:0% +the flight director have to say and I + + + align:start position:0% +the flight director have to say and I +said get him back in the + + align:start position:0% +said get him back in the + + + align:start position:0% +said get him back in the +spacecraft as loud as I could see I + + align:start position:0% +spacecraft as loud as I could see I + + + align:start position:0% +spacecraft as loud as I could see I +think one of the few times I've ever + + align:start position:0% +think one of the few times I've ever + + + align:start position:0% +think one of the few times I've ever +spoken on the air on the air + + align:start position:0% +spoken on the air on the air + + + align:start position:0% +spoken on the air on the air +ground so we were were faced with + + align:start position:0% +ground so we were were faced with + + + align:start position:0% +ground so we were were faced with +putting somebody into this new + + align:start position:0% +putting somebody into this new + + + align:start position:0% +putting somebody into this new +environment for the first time and how + + align:start position:0% +environment for the first time and how + + + align:start position:0% +environment for the first time and how +do you do that what are the problems + + align:start position:0% +do you do that what are the problems + + + align:start position:0% +do you do that what are the problems +you're fa + + align:start position:0% +you're fa + + + align:start position:0% +you're fa +with when we began to think about uh how + + align:start position:0% +with when we began to think about uh how + + + align:start position:0% +with when we began to think about uh how +we did flight tests in airplanes you + + align:start position:0% +we did flight tests in airplanes you + + + align:start position:0% +we did flight tests in airplanes you +would sit on the ground and you would + + align:start position:0% +would sit on the ground and you would + + + align:start position:0% +would sit on the ground and you would +write a flight test requirements a set + + align:start position:0% +write a flight test requirements a set + + + align:start position:0% +write a flight test requirements a set +of things you wanted him to do on a + + align:start position:0% +of things you wanted him to do on a + + + align:start position:0% +of things you wanted him to do on a +flight you'd sit on the ground hold a + + align:start position:0% +flight you'd sit on the ground hold a + + + align:start position:0% +flight you'd sit on the ground hold a +microphone and and talk to him and he'd + + align:start position:0% +microphone and and talk to him and he'd + + + align:start position:0% +microphone and and talk to him and he'd +say I just did so and so and if he was + + align:start position:0% +say I just did so and so and if he was + + + align:start position:0% +say I just did so and so and if he was +one of the best test Pils he probably + + align:start position:0% +one of the best test Pils he probably + + + align:start position:0% +one of the best test Pils he probably +didn't tell you damn thing they just + + align:start position:0% +didn't tell you damn thing they just + + + align:start position:0% +didn't tell you damn thing they just +kept quiet like Neil armstr dong did + + align:start position:0% +kept quiet like Neil armstr dong did + + + align:start position:0% +kept quiet like Neil armstr dong did +most of the time you just kept quiet you + + align:start position:0% +most of the time you just kept quiet you + + + align:start position:0% +most of the time you just kept quiet you +kept having to prompt them to tell you + + align:start position:0% +kept having to prompt them to tell you + + + align:start position:0% +kept having to prompt them to tell you +what they were doing so that's where we + + align:start position:0% +what they were doing so that's where we + + + align:start position:0% +what they were doing so that's where we +were coming from we had + + align:start position:0% +were coming from we had + + + align:start position:0% +were coming from we had +instrumentation we had been de + + align:start position:0% +instrumentation we had been de + + + align:start position:0% +instrumentation we had been de +developing Telemetry from the bomb drop + + align:start position:0% +developing Telemetry from the bomb drop + + + align:start position:0% +developing Telemetry from the bomb drop +test that we had made at Langley so we + + align:start position:0% +test that we had made at Langley so we + + + align:start position:0% +test that we had made at Langley so we +knew quite a bit about Telemetry we + + align:start position:0% +knew quite a bit about Telemetry we + + + align:start position:0% +knew quite a bit about Telemetry we +didn't know very little about air to + + align:start position:0% +didn't know very little about air to + + + align:start position:0% +didn't know very little about air to +ground we knew that we would like to + + align:start position:0% +ground we knew that we would like to + + + align:start position:0% +ground we knew that we would like to +talk to this guy about every 15 minutes + + align:start position:0% +talk to this guy about every 15 minutes + + + align:start position:0% +talk to this guy about every 15 minutes +or so + + align:start position:0% +or so + + + align:start position:0% +or so +what you did when you went across the + + align:start position:0% +what you did when you went across the + + + align:start position:0% +what you did when you went across the +country as an airplane P so if you're + + align:start position:0% +country as an airplane P so if you're + + + align:start position:0% +country as an airplane P so if you're +going around the world I like to talk to + + align:start position:0% +going around the world I like to talk to + + + align:start position:0% +going around the world I like to talk to +them about every 15 minutes and so we + + align:start position:0% +them about every 15 minutes and so we + + + align:start position:0% +them about every 15 minutes and so we +got out the geography books and said + + align:start position:0% +got out the geography books and said + + + align:start position:0% +got out the geography books and said +well we're going to fly around this + + align:start position:0% +well we're going to fly around this + + + align:start position:0% +well we're going to fly around this +thing and here's what this Chinese + + align:start position:0% +thing and here's what this Chinese + + + align:start position:0% +thing and here's what this Chinese +finger puzzle looks like as it goes + + align:start position:0% +finger puzzle looks like as it goes + + + align:start position:0% +finger puzzle looks like as it goes +around the earth and we're going to be + + align:start position:0% +around the earth and we're going to be + + + align:start position:0% +around the earth and we're going to be +over this part of the earth and this is + + align:start position:0% +over this part of the earth and this is + + + align:start position:0% +over this part of the earth and this is +where insertion is going to take place + + align:start position:0% +where insertion is going to take place + + + align:start position:0% +where insertion is going to take place +and this is where we're going to do + + align:start position:0% +and this is where we're going to do + + + align:start position:0% +and this is where we're going to do +orbit determination and this is where + + align:start position:0% +orbit determination and this is where + + + align:start position:0% +orbit determination and this is where +we're going to do + + align:start position:0% +we're going to do + + + align:start position:0% +we're going to do +retrofire and we're going to we are + + align:start position:0% +retrofire and we're going to we are + + + align:start position:0% +retrofire and we're going to we are +going to be up there going around this + + align:start position:0% +going to be up there going around this + + + align:start position:0% +going to be up there going around this +particular section of the earth and you + + align:start position:0% +particular section of the earth and you + + + align:start position:0% +particular section of the earth and you +looked at the geography and said well + + align:start position:0% +looked at the geography and said well + + + align:start position:0% +looked at the geography and said well +we've got a tracking range in Cape + + align:start position:0% +we've got a tracking range in Cape + + + align:start position:0% +we've got a tracking range in Cape +canaval we've got tracking range on the + + align:start position:0% +canaval we've got tracking range on the + + + align:start position:0% +canaval we've got tracking range on the +west coast we got a few Radars in in uh + + align:start position:0% +west coast we got a few Radars in in uh + + + align:start position:0% +west coast we got a few Radars in in uh +Australia but in between this if we're + + align:start position:0% +Australia but in between this if we're + + + align:start position:0% +Australia but in between this if we're +going to speak to them every 15 minutes + + align:start position:0% +going to speak to them every 15 minutes + + + align:start position:0% +going to speak to them every 15 minutes +this is where we'd like to be and so we + + align:start position:0% +this is where we'd like to be and so we + + + align:start position:0% +this is where we'd like to be and so we +end up saying well there's the Canary + + align:start position:0% +end up saying well there's the Canary + + + align:start position:0% +end up saying well there's the Canary +Islands there's cono there's zanar + + align:start position:0% +Islands there's cono there's zanar + + + align:start position:0% +Islands there's cono there's zanar +there's m in austral and so on and + + align:start position:0% +there's m in austral and so on and + + + align:start position:0% +there's m in austral and so on and +immediately said well if we're going to + + align:start position:0% +immediately said well if we're going to + + + align:start position:0% +immediately said well if we're going to +have to talk to them we're going to have + + align:start position:0% +have to talk to them we're going to have + + + align:start position:0% +have to talk to them we're going to have +to have reception there so we're going + + align:start position:0% +to have reception there so we're going + + + align:start position:0% +to have reception there so we're going +to have to build a station at each one + + align:start position:0% +to have to build a station at each one + + + align:start position:0% +to have to build a station at each one +of those locations and we're going to + + align:start position:0% +of those locations and we're going to + + + align:start position:0% +of those locations and we're going to +have to tie them all + + align:start position:0% +have to tie them all + + + align:start position:0% +have to tie them all +together and Lord have mercy here we are + + align:start position:0% +together and Lord have mercy here we are + + + align:start position:0% +together and Lord have mercy here we are +with a whole requirement to build a + + align:start position:0% +with a whole requirement to build a + + + align:start position:0% +with a whole requirement to build a +worldwide + + align:start position:0% +worldwide + + + align:start position:0% +worldwide +Network and nobody to do it with 35 + + align:start position:0% +Network and nobody to do it with 35 + + + align:start position:0% +Network and nobody to do it with 35 +people to do it with and so we + + align:start position:0% +people to do it with and so we + + + align:start position:0% +people to do it with and so we +immediately got a group together got + + align:start position:0% +immediately got a group together got + + + align:start position:0% +immediately got a group together got +westing house westing house Westing + + align:start position:0% +westing house westing house Westing + + + align:start position:0% +westing house westing house Westing +Electric Western elect I can't say that + + align:start position:0% +Electric Western elect I can't say that + + + align:start position:0% +Electric Western elect I can't say that +this morning Western + + align:start position:0% +this morning Western + + + align:start position:0% +this morning Western +Electric and Bell labs and bunch of + + align:start position:0% +Electric and Bell labs and bunch of + + + align:start position:0% +Electric and Bell labs and bunch of +people like that and started building + + align:start position:0% +people like that and started building + + + align:start position:0% +people like that and started building +the worldwide + + align:start position:0% +the worldwide + + + align:start position:0% +the worldwide +network uh that was a heck of a project + + align:start position:0% +network uh that was a heck of a project + + + align:start position:0% +network uh that was a heck of a project +to to to do at that point in time and + + align:start position:0% +to to to do at that point in time and + + + align:start position:0% +to to to do at that point in time and +the diplomacy just the Diplomatic + + align:start position:0% +the diplomacy just the Diplomatic + + + align:start position:0% +the diplomacy just the Diplomatic +requirements in the State uh all the + + align:start position:0% +requirements in the State uh all the + + + align:start position:0% +requirements in the State uh all the +states that we had to deal with around + + align:start position:0% +states that we had to deal with around + + + align:start position:0% +states that we had to deal with around +the world was a project in itself + + align:start position:0% +the world was a project in itself + + + align:start position:0% +the world was a project in itself +so having done that we just said how + + align:start position:0% +so having done that we just said how + + + align:start position:0% +so having done that we just said how +many times would we how many times + + align:start position:0% +many times would we how many times + + + align:start position:0% +many times would we how many times +around the earth do you think we'd like + + align:start position:0% +around the earth do you think we'd like + + + align:start position:0% +around the earth do you think we'd like +to go or need to go on the first flight + + align:start position:0% +to go or need to go on the first flight + + + align:start position:0% +to go or need to go on the first flight +and what do you think would determine + + align:start position:0% +and what do you think would determine + + + align:start position:0% +and what do you think would determine +that + + align:start position:0% +that + + + align:start position:0% +that +well in 19 + + align:start position:0% +well in 19 + + + align:start position:0% +well in 19 +59 if you put a a spacecraft up from + + align:start position:0% +59 if you put a a spacecraft up from + + + align:start position:0% +59 if you put a a spacecraft up from +Cape canaval or from vandenbberg Air + + align:start position:0% +Cape canaval or from vandenbberg Air + + + align:start position:0% +Cape canaval or from vandenbberg Air +Force + + align:start position:0% +Force + + + align:start position:0% +Force +Base and you asked is it in orbit of the + + align:start position:0% +Base and you asked is it in orbit of the + + + align:start position:0% +Base and you asked is it in orbit of the +then flight director he would + + align:start position:0% +then flight director he would + + + align:start position:0% +then flight director he would +say I don't know I'll tell you when it + + align:start position:0% +say I don't know I'll tell you when it + + + align:start position:0% +say I don't know I'll tell you when it +comes over up comes up over Kodiak + + align:start position:0% +comes over up comes up over Kodiak + + + align:start position:0% +comes over up comes up over Kodiak +Alaska 45 minutes from + + align:start position:0% +Alaska 45 minutes from + + + align:start position:0% +Alaska 45 minutes from +now and I'm saying to myself well if + + align:start position:0% +now and I'm saying to myself well if + + + align:start position:0% +now and I'm saying to myself well if +this thing isn't in orbit and I want to + + align:start position:0% +this thing isn't in orbit and I want to + + + align:start position:0% +this thing isn't in orbit and I want to +bring it down in the water before it + + align:start position:0% +bring it down in the water before it + + + align:start position:0% +bring it down in the water before it +hits the coast of Africa I've got to + + align:start position:0% +hits the coast of Africa I've got to + + + align:start position:0% +hits the coast of Africa I've got to +know when to fire turn that spacecraft + + align:start position:0% +know when to fire turn that spacecraft + + + align:start position:0% +know when to fire turn that spacecraft +or and fire the Retro Rockets So i' have + + align:start position:0% +or and fire the Retro Rockets So i' have + + + align:start position:0% +or and fire the Retro Rockets So i' have +to know + + align:start position:0% +to know + + + align:start position:0% +to know +immediately or at least within two or + + align:start position:0% +immediately or at least within two or + + + align:start position:0% +immediately or at least within two or +three minutes to turn a spacecraft + + align:start position:0% +three minutes to turn a spacecraft + + + align:start position:0% +three minutes to turn a spacecraft +around and fire the Retro Rockets what + + align:start position:0% +around and fire the Retro Rockets what + + + align:start position:0% +around and fire the Retro Rockets what +the orbit is because if I don't I don't + + align:start position:0% +the orbit is because if I don't I don't + + + align:start position:0% +the orbit is because if I don't I don't +know where it's coming down and I don't + + align:start position:0% +know where it's coming down and I don't + + + align:start position:0% +know where it's coming down and I don't +know where to send the ships to pick + + align:start position:0% +know where to send the ships to pick + + + align:start position:0% +know where to send the ships to pick +that young astronaut up so realized that + + align:start position:0% +that young astronaut up so realized that + + + align:start position:0% +that young astronaut up so realized that +in 1959 nobody knew what a short Arc + + align:start position:0% +in 1959 nobody knew what a short Arc + + + align:start position:0% +in 1959 nobody knew what a short Arc +solution was from a cand radar in 30 + + align:start position:0% +solution was from a cand radar in 30 + + + align:start position:0% +solution was from a cand radar in 30 +seconds of data furthermore they didn't + + align:start position:0% +seconds of data furthermore they didn't + + + align:start position:0% +seconds of data furthermore they didn't +have a computer to do it + + align:start position:0% +have a computer to do it + + + align:start position:0% +have a computer to do it +with you know we we were we were slide + + align:start position:0% +with you know we we were we were slide + + + align:start position:0% +with you know we we were we were slide +group people Marshon and computers crank + + align:start position:0% +group people Marshon and computers crank + + + align:start position:0% +group people Marshon and computers crank +computers and you're suddenly faced with + + align:start position:0% +computers and you're suddenly faced with + + + align:start position:0% +computers and you're suddenly faced with +the fact that you got to build a + + align:start position:0% +the fact that you got to build a + + + align:start position:0% +the fact that you got to build a +computer system to take radar data from + + align:start position:0% +computer system to take radar data from + + + align:start position:0% +computer system to take radar data from +Cape kaval and Bermuda do massage that + + align:start position:0% +Cape kaval and Bermuda do massage that + + + align:start position:0% +Cape kaval and Bermuda do massage that +data and within 30 seconds of a short + + align:start position:0% +data and within 30 seconds of a short + + + align:start position:0% +data and within 30 seconds of a short +Arc solution tell the people that have + + align:start position:0% +Arc solution tell the people that have + + + align:start position:0% +Arc solution tell the people that have +got to turn that spacecraft around and + + align:start position:0% +got to turn that spacecraft around and + + + align:start position:0% +got to turn that spacecraft around and +fire the Retro rockets in two + + align:start position:0% +fire the Retro rockets in two + + + align:start position:0% +fire the Retro rockets in two +minutes today that's + + align:start position:0% +minutes today that's + + + align:start position:0% +minutes today that's +sounds + + align:start position:0% +sounds + + + align:start position:0% +sounds +unbelievable when you talk about uh air + + align:start position:0% +unbelievable when you talk about uh air + + + align:start position:0% +unbelievable when you talk about uh air +to ground Communications or ground to + + align:start position:0% +to ground Communications or ground to + + + align:start position:0% +to ground Communications or ground to +ground Communications in + + align:start position:0% +ground Communications in + + + align:start position:0% +ground Communications in +Africa the best you had was 20 words of + + align:start position:0% +Africa the best you had was 20 words of + + + align:start position:0% +Africa the best you had was 20 words of +teletype per + + align:start position:0% +teletype per + + + align:start position:0% +teletype per +minute now so if you're going to know + + align:start position:0% +minute now so if you're going to know + + + align:start position:0% +minute now so if you're going to know +what's going on in the spacecraft or + + align:start position:0% +what's going on in the spacecraft or + + + align:start position:0% +what's going on in the spacecraft or +what the astronaut said as he flew over + + align:start position:0% +what the astronaut said as he flew over + + + align:start position:0% +what the astronaut said as he flew over +Kano Nigeria you were going to get it + + align:start position:0% +Kano Nigeria you were going to get it + + + align:start position:0% +Kano Nigeria you were going to get it +back in 20 words of t + + align:start position:0% +back in 20 words of t + + + align:start position:0% +back in 20 words of t +type so how do you make real time + + align:start position:0% +type so how do you make real time + + + align:start position:0% +type so how do you make real time +decisions under those circumstances what + + align:start position:0% +decisions under those circumstances what + + + align:start position:0% +decisions under those circumstances what +is a real time + + align:start position:0% +is a real time + + + align:start position:0% +is a real time +decision where are you going to make it + + align:start position:0% +decision where are you going to make it + + + align:start position:0% +decision where are you going to make it +a decision do you need some Central + + align:start position:0% +a decision do you need some Central + + + align:start position:0% +a decision do you need some Central +facility which invented mission + + align:start position:0% +facility which invented mission + + + align:start position:0% +facility which invented mission +control and suddenly then if we're going + + align:start position:0% +control and suddenly then if we're going + + + align:start position:0% +control and suddenly then if we're going +to do this job and we're going to have + + align:start position:0% +to do this job and we're going to have + + + align:start position:0% +to do this job and we're going to have +uh people looking at this data we've got + + align:start position:0% +uh people looking at this data we've got + + + align:start position:0% +uh people looking at this data we've got +to train a group of people to go to all + + align:start position:0% +to train a group of people to go to all + + + align:start position:0% +to train a group of people to go to all +these locations around the world and if + + align:start position:0% +these locations around the world and if + + + align:start position:0% +these locations around the world and if +you're going to make decisions in a + + align:start position:0% +you're going to make decisions in a + + + align:start position:0% +you're going to make decisions in a +central + + align:start position:0% +central + + + align:start position:0% +central +location then you've got to have some + + align:start position:0% +location then you've got to have some + + + align:start position:0% +location then you've got to have some +means of getting that data back to them + + align:start position:0% +means of getting that data back to them + + + align:start position:0% +means of getting that data back to them +of massaging that data letting people + + align:start position:0% +of massaging that data letting people + + + align:start position:0% +of massaging that data letting people +know outside the the limits of that + + align:start position:0% +know outside the the limits of that + + + align:start position:0% +know outside the the limits of that +control facility what is going on so + + align:start position:0% +control facility what is going on so + + + align:start position:0% +control facility what is going on so +they can interrelate with each other + + align:start position:0% +they can interrelate with each other + + + align:start position:0% +they can interrelate with each other +nobody had ever done that before and the + + align:start position:0% +nobody had ever done that before and the + + + align:start position:0% +nobody had ever done that before and the +first time we cranked ourselves up in a + + align:start position:0% +first time we cranked ourselves up in a + + + align:start position:0% +first time we cranked ourselves up in a +bunch of small kobby holds in a old + + align:start position:0% +bunch of small kobby holds in a old + + + align:start position:0% +bunch of small kobby holds in a old +flight wind tunnel building in lley + + align:start position:0% +flight wind tunnel building in lley + + + align:start position:0% +flight wind tunnel building in lley +field Virginia and started doing what we + + align:start position:0% +field Virginia and started doing what we + + + align:start position:0% +field Virginia and started doing what we +would call the initial simulations we + + align:start position:0% +would call the initial simulations we + + + align:start position:0% +would call the initial simulations we +found out we didn't even know how to + + align:start position:0% +found out we didn't even know how to + + + align:start position:0% +found out we didn't even know how to +talk with each other and everybody was + + align:start position:0% +talk with each other and everybody was + + + align:start position:0% +talk with each other and everybody was +talking at + + align:start position:0% +talking at + + + align:start position:0% +talking at +once so we had to invent a whole new + + align:start position:0% +once so we had to invent a whole new + + + align:start position:0% +once so we had to invent a whole new +language had to have negative reporting + + align:start position:0% +language had to have negative reporting + + + align:start position:0% +language had to have negative reporting +and things like that which people had + + align:start position:0% +and things like that which people had + + + align:start position:0% +and things like that which people had +never heard of + + align:start position:0% +never heard of + + + align:start position:0% +never heard of +before and rapidly then we began to + + align:start position:0% +before and rapidly then we began to + + + align:start position:0% +before and rapidly then we began to +realize we had a big task in front of us + + align:start position:0% +realize we had a big task in front of us + + + align:start position:0% +realize we had a big task in front of us +if you're going to recover this + + align:start position:0% +if you're going to recover this + + + align:start position:0% +if you're going to recover this +gentleman uh at the end of the flight + + align:start position:0% +gentleman uh at the end of the flight + + + align:start position:0% +gentleman uh at the end of the flight +that's not too hard we can send a few + + align:start position:0% +that's not too hard we can send a few + + + align:start position:0% +that's not too hard we can send a few +ships out there and we probably ought to + + align:start position:0% +ships out there and we probably ought to + + + align:start position:0% +ships out there and we probably ought to +have a helicopter there to pick them up + + align:start position:0% +have a helicopter there to pick them up + + + align:start position:0% +have a helicopter there to pick them up +and maybe we can have one of these light + + align:start position:0% +and maybe we can have one of these light + + + align:start position:0% +and maybe we can have one of these light +carriers but if the doctors are right we + + align:start position:0% +carriers but if the doctors are right we + + + align:start position:0% +carriers but if the doctors are right we +might have to come down + + align:start position:0% +might have to come down + + + align:start position:0% +might have to come down +anywhere anywhere in the 360 degrees on + + align:start position:0% +anywhere anywhere in the 360 degrees on + + + align:start position:0% +anywhere anywhere in the 360 degrees on +those three revolutions now who are we + + align:start position:0% +those three revolutions now who are we + + + align:start position:0% +those three revolutions now who are we +talking to we're talking about talking + + align:start position:0% +talking to we're talking about talking + + + align:start position:0% +talking to we're talking about talking +to the search and rescue people we're + + align:start position:0% +to the search and rescue people we're + + + align:start position:0% +to the search and rescue people we're +talking to Destroyer captains we're + + align:start position:0% +talking to Destroyer captains we're + + + align:start position:0% +talking to Destroyer captains we're +talking to people that have got to fish + + align:start position:0% +talking to people that have got to fish + + + align:start position:0% +talking to people that have got to fish +this thing out of the sea and how did + + align:start position:0% +this thing out of the sea and how did + + + align:start position:0% +this thing out of the sea and how did +they do that and how do they not get + + align:start position:0% +they do that and how do they not get + + + align:start position:0% +they do that and how do they not get +burned with the fuel that might be + + align:start position:0% +burned with the fuel that might be + + + align:start position:0% +burned with the fuel that might be +running out of the spacecraft and + + align:start position:0% +running out of the spacecraft and + + + align:start position:0% +running out of the spacecraft and +suddenly we have to train probably + + align:start position:0% +suddenly we have to train probably + + + align:start position:0% +suddenly we have to train probably +10,000 + + align:start position:0% +10,000 + + + align:start position:0% +10,000 +people and how to recover this machine + + align:start position:0% +people and how to recover this machine + + + align:start position:0% +people and how to recover this machine +or how do you if this if the spacecraft + + align:start position:0% +or how do you if this if the spacecraft + + + align:start position:0% +or how do you if this if the spacecraft +is sitting in the water we've got to + + align:start position:0% +is sitting in the water we've got to + + + align:start position:0% +is sitting in the water we've got to +train several hundred frog men how to + + align:start position:0% +train several hundred frog men how to + + + align:start position:0% +train several hundred frog men how to +jump out of an airplane with tools to + + align:start position:0% +jump out of an airplane with tools to + + + align:start position:0% +jump out of an airplane with tools to +get to the + + align:start position:0% +get to the + + + align:start position:0% +get to the +astronaut so it it was a tremendous task + + align:start position:0% +astronaut so it it was a tremendous task + + + align:start position:0% +astronaut so it it was a tremendous task +for a group of people who had never done + + align:start position:0% +for a group of people who had never done + + + align:start position:0% +for a group of people who had never done +much but do wind tunnel tests or flight + + align:start position:0% +much but do wind tunnel tests or flight + + + align:start position:0% +much but do wind tunnel tests or flight +tests at L + + align:start position:0% +tests at L + + + align:start position:0% +tests at L +field so the early days we had to to + + align:start position:0% +field so the early days we had to to + + + align:start position:0% +field so the early days we had to to +come up with orbit + + align:start position:0% +come up with orbit + + + align:start position:0% +come up with orbit +determination how to look at the + + align:start position:0% +determination how to look at the + + + align:start position:0% +determination how to look at the +astronaut's Health how do we get + + align:start position:0% +astronaut's Health how do we get + + + align:start position:0% +astronaut's Health how do we get +something down that we can look at can + + align:start position:0% +something down that we can look at can + + + align:start position:0% +something down that we can look at can +we get an e G down can we get his his + + align:start position:0% +we get an e G down can we get his his + + + align:start position:0% +we get an e G down can we get his his +breath rate down to the each one of + + align:start position:0% +breath rate down to the each one of + + + align:start position:0% +breath rate down to the each one of +these stations so we know what the man's + + align:start position:0% +these stations so we know what the man's + + + align:start position:0% +these stations so we know what the man's +health is an interesting story what we + + align:start position:0% +health is an interesting story what we + + + align:start position:0% +health is an interesting story what we +did eventually build a a a simulator to + + align:start position:0% +did eventually build a a a simulator to + + + align:start position:0% +did eventually build a a a simulator to +train the + + align:start position:0% +train the + + + align:start position:0% +train the +astronauts and we had no way of getting + + align:start position:0% +astronauts and we had no way of getting + + + align:start position:0% +astronauts and we had no way of getting +data to each one of these sites around + + align:start position:0% +data to each one of these sites around + + + align:start position:0% +data to each one of these sites around +the world that would allow us to run a + + align:start position:0% +the world that would allow us to run a + + + align:start position:0% +the world that would allow us to run a +full-fledged worldwide simulation in + + align:start position:0% +full-fledged worldwide simulation in + + + align:start position:0% +full-fledged worldwide simulation in +real time so we would put it on tape cut + + align:start position:0% +real time so we would put it on tape cut + + + align:start position:0% +real time so we would put it on tape cut +it up in + + align:start position:0% +it up in + + + align:start position:0% +it up in +sections send out a + + align:start position:0% +sections send out a + + + align:start position:0% +sections send out a +script of what the astronaut was going + + align:start position:0% +script of what the astronaut was going + + + align:start position:0% +script of what the astronaut was going +to say and do and play this six or eight + + align:start position:0% +to say and do and play this six or eight + + + align:start position:0% +to say and do and play this six or eight +minutes of a tape as that's what they + + align:start position:0% +minutes of a tape as that's what they + + + align:start position:0% +minutes of a tape as that's what they +would see as the spacecraft appeared + + align:start position:0% +would see as the spacecraft appeared + + + align:start position:0% +would see as the spacecraft appeared +over their station and when we said well + + align:start position:0% +over their station and when we said well + + + align:start position:0% +over their station and when we said well +we got to train a bunch of + + align:start position:0% +we got to train a bunch of + + + align:start position:0% +we got to train a bunch of +doctors an interesting story was we went + + align:start position:0% +doctors an interesting story was we went + + + align:start position:0% +doctors an interesting story was we went +down to the Veterans Administration in + + align:start position:0% +down to the Veterans Administration in + + + align:start position:0% +down to the Veterans Administration in +uh Houston and said well we we'd like to + + align:start position:0% +uh Houston and said well we we'd like to + + + align:start position:0% +uh Houston and said well we we'd like to +uh + + align:start position:0% +uh + + + align:start position:0% +uh +put some instruments that we were + + align:start position:0% +put some instruments that we were + + + align:start position:0% +put some instruments that we were +developing on people that are sick here + + align:start position:0% +developing on people that are sick here + + + align:start position:0% +developing on people that are sick here +and so as they come in various types of + + align:start position:0% +and so as they come in various types of + + + align:start position:0% +and so as they come in various types of +diseases and fortunately one day we had + + align:start position:0% +diseases and fortunately one day we had + + + align:start position:0% +diseases and fortunately one day we had +a guy instrumented and he had a heart + + align:start position:0% +a guy instrumented and he had a heart + + + align:start position:0% +a guy instrumented and he had a heart +attack so we were able to record all + + align:start position:0% +attack so we were able to record all + + + align:start position:0% +attack so we were able to record all +these things that were going on in this + + align:start position:0% +these things that were going on in this + + + align:start position:0% +these things that were going on in this +gentleman his temperature is his EKG his + + align:start position:0% +gentleman his temperature is his EKG his + + + align:start position:0% +gentleman his temperature is his EKG his +breath rate and what his blood pressure + + align:start position:0% +breath rate and what his blood pressure + + + align:start position:0% +breath rate and what his blood pressure +was and so + + align:start position:0% +was and so + + + align:start position:0% +was and so +on and put all that on the + + align:start position:0% +on and put all that on the + + + align:start position:0% +on and put all that on the +tape sent that out to the remote sites + + align:start position:0% +tape sent that out to the remote sites + + + align:start position:0% +tape sent that out to the remote sites +and then had each of the sites as this + + align:start position:0% +and then had each of the sites as this + + + align:start position:0% +and then had each of the sites as this +occurred have the doctors + + align:start position:0% +occurred have the doctors + + + align:start position:0% +occurred have the doctors +diagnose what was wrong with the + + align:start position:0% +diagnose what was wrong with the + + + align:start position:0% +diagnose what was wrong with the +astronaut I don't believe in any one of + + align:start position:0% +astronaut I don't believe in any one of + + + align:start position:0% +astronaut I don't believe in any one of +the 17 stations we had anybody diagnosed + + align:start position:0% +the 17 stations we had anybody diagnosed + + + align:start position:0% +the 17 stations we had anybody diagnosed +it as a heart + + align:start position:0% +it as a heart + + + align:start position:0% +it as a heart +attack they all said he had appendicitis + + align:start position:0% +attack they all said he had appendicitis + + + align:start position:0% +attack they all said he had appendicitis +or he was having + + align:start position:0% +or he was having + + + align:start position:0% +or he was having +a some kind of shock take place to him + + align:start position:0% +a some kind of shock take place to him + + + align:start position:0% +a some kind of shock take place to him +because he was frightened to death or + + align:start position:0% +because he was frightened to death or + + + align:start position:0% +because he was frightened to death or +any anything but a heart attack so that + + align:start position:0% +any anything but a heart attack so that + + + align:start position:0% +any anything but a heart attack so that +was sort of classical of the things we + + align:start position:0% +was sort of classical of the things we + + + align:start position:0% +was sort of classical of the things we +did and improvised in order + + align:start position:0% +did and improvised in order + + + align:start position:0% +did and improvised in order +to get ourselves capable of running a + + align:start position:0% +to get ourselves capable of running a + + + align:start position:0% +to get ourselves capable of running a +worldwide operation which allowed us to + + align:start position:0% +worldwide operation which allowed us to + + + align:start position:0% +worldwide operation which allowed us to +make decisions in real time now the + + align:start position:0% +make decisions in real time now the + + + align:start position:0% +make decisions in real time now the +other thing that we invented at that + + align:start position:0% +other thing that we invented at that + + + align:start position:0% +other thing that we invented at that +time I say invented it just came about + + align:start position:0% +time I say invented it just came about + + + align:start position:0% +time I say invented it just came about +by Evolution was the book called Mission + + align:start position:0% +by Evolution was the book called Mission + + + align:start position:0% +by Evolution was the book called Mission +rules and that was probably the smartest + + align:start position:0% +rules and that was probably the smartest + + + align:start position:0% +rules and that was probably the smartest +thing we ever did as we began to look at + + align:start position:0% +thing we ever did as we began to look at + + + align:start position:0% +thing we ever did as we began to look at +the spacecraft system + + align:start position:0% +the spacecraft system + + + align:start position:0% +the spacecraft system +we started asking questions well if this + + align:start position:0% +we started asking questions well if this + + + align:start position:0% +we started asking questions well if this +system is + + align:start position:0% +system is + + + align:start position:0% +system is +failing what are the measurements that + + align:start position:0% +failing what are the measurements that + + + align:start position:0% +failing what are the measurements that +we're going to have there and and if it + + align:start position:0% +we're going to have there and and if it + + + align:start position:0% +we're going to have there and and if it +is failing what and it isn't operating + + align:start position:0% +is failing what and it isn't operating + + + align:start position:0% +is failing what and it isn't operating +at the right temperature at the right + + align:start position:0% +at the right temperature at the right + + + align:start position:0% +at the right temperature at the right +pressure and it's off nominal what will + + align:start position:0% +pressure and it's off nominal what will + + + align:start position:0% +pressure and it's off nominal what will +the system do and how do we measure that + + align:start position:0% +the system do and how do we measure that + + + align:start position:0% +the system do and how do we measure that +on the ground how we detect it where is + + align:start position:0% +on the ground how we detect it where is + + + align:start position:0% +on the ground how we detect it where is +the instrument located on the system + + align:start position:0% +the instrument located on the system + + + align:start position:0% +the instrument located on the system +because it might be affected by the + + align:start position:0% +because it might be affected by the + + + align:start position:0% +because it might be affected by the +position it's located in the spacecraft + + align:start position:0% +position it's located in the spacecraft + + + align:start position:0% +position it's located in the spacecraft +it might be hot might be cold might be + + align:start position:0% +it might be hot might be cold might be + + + align:start position:0% +it might be hot might be cold might be +suffering different kinds of pressures + + align:start position:0% +suffering different kinds of pressures + + + align:start position:0% +suffering different kinds of pressures +than it was measured on the ground and + + align:start position:0% +than it was measured on the ground and + + + align:start position:0% +than it was measured on the ground and +as we began to ask those questions of + + align:start position:0% +as we began to ask those questions of + + + align:start position:0% +as we began to ask those questions of +the systems + + align:start position:0% +the systems + + + align:start position:0% +the systems +engineer the system engineer not systems + + align:start position:0% +engineer the system engineer not systems + + + align:start position:0% +engineer the system engineer not systems +Engineers because I don't think we had + + align:start position:0% +Engineers because I don't think we had + + + align:start position:0% +Engineers because I don't think we had +any at the + + align:start position:0% +any at the + + + align:start position:0% +any at the +time and you began and they would say + + align:start position:0% +time and you began and they would say + + + align:start position:0% +time and you began and they would say +why the hell do you want to know that + + align:start position:0% +why the hell do you want to know that + + + align:start position:0% +why the hell do you want to know that +the system is either working or it ain't + + align:start position:0% +the system is either working or it ain't + + + align:start position:0% +the system is either working or it ain't +working and we said yes that's a good + + align:start position:0% +working and we said yes that's a good + + + align:start position:0% +working and we said yes that's a good +answer except that now we've got this + + align:start position:0% +answer except that now we've got this + + + align:start position:0% +answer except that now we've got this +system in space and if we want to + + align:start position:0% +system in space and if we want to + + + align:start position:0% +system in space and if we want to +continue this flight and not have a + + align:start position:0% +continue this flight and not have a + + + align:start position:0% +continue this flight and not have a +contingency operation we'd like to know + + align:start position:0% +contingency operation we'd like to know + + + align:start position:0% +contingency operation we'd like to know +how how long the system is going to last + + align:start position:0% +how how long the system is going to last + + + align:start position:0% +how how long the system is going to last +if it isn't operating under normal + + align:start position:0% +if it isn't operating under normal + + + align:start position:0% +if it isn't operating under normal +conditions so that prompted us then to + + align:start position:0% +conditions so that prompted us then to + + + align:start position:0% +conditions so that prompted us then to +start thinking about how the system + + align:start position:0% +start thinking about how the system + + + align:start position:0% +start thinking about how the system +failed and what we were going to do + + align:start position:0% +failed and what we were going to do + + + align:start position:0% +failed and what we were going to do +about it if the if the thermal system + + align:start position:0% +about it if the if the thermal system + + + align:start position:0% +about it if the if the thermal system +that kept the astronaut from getting hot + + align:start position:0% +that kept the astronaut from getting hot + + + align:start position:0% +that kept the astronaut from getting hot +or getting too cold wasn't functioning + + align:start position:0% +or getting too cold wasn't functioning + + + align:start position:0% +or getting too cold wasn't functioning +properly what could we do about it how + + align:start position:0% +properly what could we do about it how + + + align:start position:0% +properly what could we do about it how +long could he stand being at a + + align:start position:0% +long could he stand being at a + + + align:start position:0% +long could he stand being at a +temperature of 85 degrees inside his + + align:start position:0% +temperature of 85 degrees inside his + + + align:start position:0% +temperature of 85 degrees inside his +space suit and and then that said well + + align:start position:0% +space suit and and then that said well + + + align:start position:0% +space suit and and then that said well +if it stays there and we can only go X + + align:start position:0% +if it stays there and we can only go X + + + align:start position:0% +if it stays there and we can only go X +number of minutes what are we going to + + align:start position:0% +number of minutes what are we going to + + + align:start position:0% +number of minutes what are we going to +do about it what is the the rule of the + + align:start position:0% +do about it what is the the rule of the + + + align:start position:0% +do about it what is the the rule of the +game that says we should re-enter or not + + align:start position:0% +game that says we should re-enter or not + + + align:start position:0% +game that says we should re-enter or not +reenter or go to the next primary + + align:start position:0% +reenter or go to the next primary + + + align:start position:0% +reenter or go to the next primary +recovery area Etc and it allowed us then + + align:start position:0% +recovery area Etc and it allowed us then + + + align:start position:0% +recovery area Etc and it allowed us then +to write down for almost every for every + + align:start position:0% +to write down for almost every for every + + + align:start position:0% +to write down for almost every for every +system and the man + + align:start position:0% +system and the man + + + align:start position:0% +system and the man +what we would do under certain + + align:start position:0% +what we would do under certain + + + align:start position:0% +what we would do under certain +circumstances call those a set of + + align:start position:0% +circumstances call those a set of + + + align:start position:0% +circumstances call those a set of +mission rules and that prompted us to + + align:start position:0% +mission rules and that prompted us to + + + align:start position:0% +mission rules and that prompted us to +develop a bunch of + + align:start position:0% +develop a bunch of + + + align:start position:0% +develop a bunch of +malfunction uh criteria what what + + align:start position:0% +malfunction uh criteria what what + + + align:start position:0% +malfunction uh criteria what what +malfunction procedures do you are you + + align:start position:0% +malfunction procedures do you are you + + + align:start position:0% +malfunction procedures do you are you +going to go through and then that + + align:start position:0% +going to go through and then that + + + align:start position:0% +going to go through and then that +prompted us to ask the contractor and + + align:start position:0% +prompted us to ask the contractor and + + + align:start position:0% +prompted us to ask the contractor and +the manufacturer of the systems and that + + align:start position:0% +the manufacturer of the systems and that + + + align:start position:0% +the manufacturer of the systems and that +developed a whole new set of schematics + + align:start position:0% +developed a whole new set of schematics + + + align:start position:0% +developed a whole new set of schematics +that they hadn't been used to cost us a + + align:start position:0% +that they hadn't been used to cost us a + + + align:start position:0% +that they hadn't been used to cost us a +lot of money to do that they didn't want + + align:start position:0% +lot of money to do that they didn't want + + + align:start position:0% +lot of money to do that they didn't want +to do it they didn't know why we wanted + + align:start position:0% +to do it they didn't know why we wanted + + + align:start position:0% +to do it they didn't know why we wanted +to do it but as they began to see the + + align:start position:0% +to do it but as they began to see the + + + align:start position:0% +to do it but as they began to see the +mission rules and we got those out in + + align:start position:0% +mission rules and we got those out in + + + align:start position:0% +mission rules and we got those out in +front of them and said we're going to do + + align:start position:0% +front of them and said we're going to do + + + align:start position:0% +front of them and said we're going to do +this with your spacecraft and your + + align:start position:0% +this with your spacecraft and your + + + align:start position:0% +this with your spacecraft and your +system then they began to realize they + + align:start position:0% +system then they began to realize they + + + align:start position:0% +system then they began to realize they +better start thinking about those things + + align:start position:0% +better start thinking about those things + + + align:start position:0% +better start thinking about those things +and that's what brought in my mind a + + align:start position:0% +and that's what brought in my mind a + + + align:start position:0% +and that's what brought in my mind a +group of people together in systems + + align:start position:0% +group of people together in systems + + + align:start position:0% +group of people together in systems +engineer because you began to find out + + align:start position:0% +engineer because you began to find out + + + align:start position:0% +engineer because you began to find out +how the systems reacted with each + + align:start position:0% +how the systems reacted with each + + + align:start position:0% +how the systems reacted with each +other and that was a question that most + + align:start position:0% +other and that was a question that most + + + align:start position:0% +other and that was a question that most +Engineers didn't think about if if the + + align:start position:0% +Engineers didn't think about if if the + + + align:start position:0% +Engineers didn't think about if if the +ther control system is not functioning + + align:start position:0% +ther control system is not functioning + + + align:start position:0% +ther control system is not functioning +properly what does it do to the reaction + + align:start position:0% +properly what does it do to the reaction + + + align:start position:0% +properly what does it do to the reaction +control system or as we had on one of + + align:start position:0% +control system or as we had on one of + + + align:start position:0% +control system or as we had on one of +our first orbital flights the the seats + + align:start position:0% +our first orbital flights the the seats + + + align:start position:0% +our first orbital flights the the seats +on the small thrusters that were using + + align:start position:0% +on the small thrusters that were using + + + align:start position:0% +on the small thrusters that were using +for attitude control were not seating + + align:start position:0% +for attitude control were not seating + + + align:start position:0% +for attitude control were not seating +properly and the experts said it's + + align:start position:0% +properly and the experts said it's + + + align:start position:0% +properly and the experts said it's +freezing it's getting slush in the + + align:start position:0% +freezing it's getting slush in the + + + align:start position:0% +freezing it's getting slush in the +system and it's causing the valves to + + align:start position:0% +system and it's causing the valves to + + + align:start position:0% +system and it's causing the valves to +stay open and they're not getting a + + align:start position:0% +stay open and they're not getting a + + + align:start position:0% +stay open and they're not getting a +proper fluid to it so we put a thermost + + align:start position:0% +proper fluid to it so we put a thermost + + + align:start position:0% +proper fluid to it so we put a thermost +on the next spacecraft and it was + + align:start position:0% +on the next spacecraft and it was + + + align:start position:0% +on the next spacecraft and it was +freezing it was getting hot because the + + align:start position:0% +freezing it was getting hot because the + + + align:start position:0% +freezing it was getting hot because the +feedback from the Thruster was getting + + align:start position:0% +feedback from the Thruster was getting + + + align:start position:0% +feedback from the Thruster was getting +on the lines and causing the seats to + + align:start position:0% +on the lines and causing the seats to + + + align:start position:0% +on the lines and causing the seats to +war and it was sitting there dribbling + + align:start position:0% +war and it was sitting there dribbling + + + align:start position:0% +war and it was sitting there dribbling +out and causing the attitude to be + + align:start position:0% +out and causing the attitude to be + + + align:start position:0% +out and causing the attitude to be +sloppy and jump around and as a matter + + align:start position:0% +sloppy and jump around and as a matter + + + align:start position:0% +sloppy and jump around and as a matter +of fact on one flight we had to reenter + + align:start position:0% +of fact on one flight we had to reenter + + + align:start position:0% +of fact on one flight we had to reenter +early with the first chimpanzee flight + + align:start position:0% +early with the first chimpanzee flight + + + align:start position:0% +early with the first chimpanzee flight +because the machine was running out of + + align:start position:0% +because the machine was running out of + + + align:start position:0% +because the machine was running out of +propellant so it began to have everybody + + align:start position:0% +propellant so it began to have everybody + + + align:start position:0% +propellant so it began to have everybody +start thinking about how does my system + + align:start position:0% +start thinking about how does my system + + + align:start position:0% +start thinking about how does my system +fit with everybody else's system how + + align:start position:0% +fit with everybody else's system how + + + align:start position:0% +fit with everybody else's system how +does that fit with the game plan that + + align:start position:0% +does that fit with the game plan that + + + align:start position:0% +does that fit with the game plan that +we're trying to come up + + align:start position:0% +we're trying to come up + + + align:start position:0% +we're trying to come up +with + + align:start position:0% +with + + + align:start position:0% +with +and at the same + + align:start position:0% +and at the same + + + align:start position:0% +and at the same +time uh the organization then was able + + align:start position:0% +time uh the organization then was able + + + align:start position:0% +time uh the organization then was able +to look at all of these things that we + + align:start position:0% +to look at all of these things that we + + + align:start position:0% +to look at all of these things that we +said we were going to do and became a + + align:start position:0% +said we were going to do and became a + + + align:start position:0% +said we were going to do and became a +heck of a management tool I remember + + align:start position:0% +heck of a management tool I remember + + + align:start position:0% +heck of a management tool I remember +James web used I used to come down + + align:start position:0% +James web used I used to come down + + + align:start position:0% +James web used I used to come down +administrator mass at the time and I + + align:start position:0% +administrator mass at the time and I + + + align:start position:0% +administrator mass at the time and I +would show him in the control center how + + align:start position:0% +would show him in the control center how + + + align:start position:0% +would show him in the control center how +we ran an operation and how we made + + align:start position:0% +we ran an operation and how we made + + + align:start position:0% +we ran an operation and how we made +decisions and he was absolutely + + align:start position:0% +decisions and he was absolutely + + + align:start position:0% +decisions and he was absolutely +livid about that because he said that's + + align:start position:0% +livid about that because he said that's + + + align:start position:0% +livid about that because he said that's +what I want in + + align:start position:0% +what I want in + + + align:start position:0% +what I want in +Washington I want to be able to have + + align:start position:0% +Washington I want to be able to have + + + align:start position:0% +Washington I want to be able to have +those kinds of things put in front of me + + align:start position:0% +those kinds of things put in front of me + + + align:start position:0% +those kinds of things put in front of me +so I got all these things so I can make + + align:start position:0% +so I got all these things so I can make + + + align:start position:0% +so I got all these things so I can make +a decision I need you in Wasing I want + + align:start position:0% +a decision I need you in Wasing I want + + + align:start position:0% +a decision I need you in Wasing I want +you to come up here and fix tell me how + + align:start position:0% +you to come up here and fix tell me how + + + align:start position:0% +you to come up here and fix tell me how +to build a system like that to do + + align:start position:0% +to build a system like that to do + + + align:start position:0% +to build a system like that to do +management I must say that I've never + + align:start position:0% +management I must say that I've never + + + align:start position:0% +management I must say that I've never +been able to do that but + + align:start position:0% +been able to do that but + + + align:start position:0% +been able to do that but +was very emphatic about wanting to do + + align:start position:0% + + + + align:start position:0% + +that uh jump to the conclusion of + + align:start position:0% +that uh jump to the conclusion of + + + align:start position:0% +that uh jump to the conclusion of +mercury I think we learned an awful lot + + align:start position:0% +mercury I think we learned an awful lot + + + align:start position:0% +mercury I think we learned an awful lot +from that program we learned that man + + align:start position:0% +from that program we learned that man + + + align:start position:0% +from that program we learned that man +could do a a job he could do it just as + + align:start position:0% +could do a a job he could do it just as + + + align:start position:0% +could do a a job he could do it just as +well at zero gravity and particularly in + + align:start position:0% +well at zero gravity and particularly in + + + align:start position:0% +well at zero gravity and particularly in +Mercury where he couldn't move around he + + align:start position:0% +Mercury where he couldn't move around he + + + align:start position:0% +Mercury where he couldn't move around he +didn't get sick fortunately as he did + + align:start position:0% +didn't get sick fortunately as he did + + + align:start position:0% +didn't get sick fortunately as he did +eventually in some of our spacecraft but + + align:start position:0% +eventually in some of our spacecraft but + + + align:start position:0% +eventually in some of our spacecraft but +certainly man could do the job in space + + align:start position:0% +certainly man could do the job in space + + + align:start position:0% +certainly man could do the job in space +as well + + align:start position:0% +as well + + + align:start position:0% +as well +up there as you could in a fighter + + align:start position:0% +up there as you could in a fighter + + + align:start position:0% +up there as you could in a fighter +airplane on the + + align:start position:0% +airplane on the + + + align:start position:0% +airplane on the +earth uh but it was Child's + + align:start position:0% +earth uh but it was Child's + + + align:start position:0% +earth uh but it was Child's +Play Mercury was Child's Play we put it + + align:start position:0% +Play Mercury was Child's Play we put it + + + align:start position:0% +Play Mercury was Child's Play we put it +up there we fired the Retro rockets and + + align:start position:0% +up there we fired the Retro rockets and + + + align:start position:0% +up there we fired the Retro rockets and +it landed and we picked them + + align:start position:0% +it landed and we picked them + + + align:start position:0% +it landed and we picked them +up a hell of a job at that time but it + + align:start position:0% +up a hell of a job at that time but it + + + align:start position:0% +up a hell of a job at that time but it +was Child's Play and + + align:start position:0% +was Child's Play and + + + align:start position:0% +was Child's Play and +so Mr Kennedy and his great + + align:start position:0% +so Mr Kennedy and his great + + + align:start position:0% +so Mr Kennedy and his great +wisdom in April of 1962 + + align:start position:0% +wisdom in April of 1962 + + + align:start position:0% +wisdom in April of 1962 +uh excuse me 61 when he saw the reaction + + align:start position:0% +uh excuse me 61 when he saw the reaction + + + align:start position:0% +uh excuse me 61 when he saw the reaction +of the world to Alan Shephard's First + + align:start position:0% +of the world to Alan Shephard's First + + + align:start position:0% +of the world to Alan Shephard's First +Flight asked NASA well what what can we + + align:start position:0% +Flight asked NASA well what what can we + + + align:start position:0% +Flight asked NASA well what what can we +do to Ace the + + align:start position:0% +do to Ace the + + + align:start position:0% +do to Ace the +Russians and NASA in its great wisdom + + align:start position:0% +Russians and NASA in its great wisdom + + + align:start position:0% +Russians and NASA in its great wisdom +said well probably in about 10 years we + + align:start position:0% +said well probably in about 10 years we + + + align:start position:0% +said well probably in about 10 years we +can go around the + + align:start position:0% +can go around the + + + align:start position:0% +can go around the +Moon George low and others in Washington + + align:start position:0% +Moon George low and others in Washington + + + align:start position:0% +Moon George low and others in Washington +had been doing some work on on lunar + + align:start position:0% +had been doing some work on on lunar + + + align:start position:0% +had been doing some work on on lunar +spacecraft + + align:start position:0% +spacecraft + + + align:start position:0% +spacecraft +and in the great wisdom of whoever made + + align:start position:0% +and in the great wisdom of whoever made + + + align:start position:0% +and in the great wisdom of whoever made +such a decision the president asked why + + align:start position:0% +such a decision the president asked why + + + align:start position:0% +such a decision the president asked why +don't why can't you land on the + + align:start position:0% +don't why can't you land on the + + + align:start position:0% +don't why can't you land on the +Move now I want you to know that that + + align:start position:0% +Move now I want you to know that that + + + align:start position:0% +Move now I want you to know that that +was 1961 and Chris Kraft did not know + + align:start position:0% +was 1961 and Chris Kraft did not know + + + align:start position:0% +was 1961 and Chris Kraft did not know +how to + + align:start position:0% +how to + + + align:start position:0% +how to +determine orbital mechanics from 30 + + align:start position:0% +determine orbital mechanics from 30 + + + align:start position:0% +determine orbital mechanics from 30 +seconds of radar at C + + align:start position:0% +seconds of radar at C + + + align:start position:0% +seconds of radar at C +canaval and this man in 1961 says we're + + align:start position:0% +canaval and this man in 1961 says we're + + + align:start position:0% +canaval and this man in 1961 says we're +going to the Moon in this + + align:start position:0% + + + + align:start position:0% + +decade and I thought he was a little + + align:start position:0% + + + + align:start position:0% + +daed I must say I thought he was a + + align:start position:0% +daed I must say I thought he was a + + + align:start position:0% +daed I must say I thought he was a +little D the second + + align:start position:0% +little D the second + + + align:start position:0% +little D the second +day + + align:start position:0% +day + + + align:start position:0% +day +I uh thought a little bit better of it + + align:start position:0% +I uh thought a little bit better of it + + + align:start position:0% +I uh thought a little bit better of it +and then about three months later when + + align:start position:0% +and then about three months later when + + + align:start position:0% +and then about three months later when +he came to make that famous + + align:start position:0% +he came to make that famous + + + align:start position:0% +he came to make that famous +speech in + + align:start position:0% +speech in + + + align:start position:0% +speech in +uh uh rice Stadium + + align:start position:0% +uh uh rice Stadium + + + align:start position:0% +uh uh rice Stadium +I was called back from Cape canaval to + + align:start position:0% +I was called back from Cape canaval to + + + align:start position:0% +I was called back from Cape canaval to +tell him how we were going to go to the + + align:start position:0% + + + + align:start position:0% + +moon and I'm telling you I did not know + + align:start position:0% +moon and I'm telling you I did not know + + + align:start position:0% +moon and I'm telling you I did not know +a damn thing about how to go to the bo + + align:start position:0% +a damn thing about how to go to the bo + + + align:start position:0% +a damn thing about how to go to the bo +you know if you had + + align:start position:0% +you know if you had + + + align:start position:0% +you know if you had +said free return trajectory to me God + + align:start position:0% +said free return trajectory to me God + + + align:start position:0% +said free return trajectory to me God +I'd have thought it was a pass to the + + align:start position:0% +I'd have thought it was a pass to the + + + align:start position:0% +I'd have thought it was a pass to the +Astros baseball + + align:start position:0% + + + + align:start position:0% + +game but here I was faced with the fact + + align:start position:0% +game but here I was faced with the fact + + + align:start position:0% +game but here I was faced with the fact +I've got to stand up in front of the + + align:start position:0% +I've got to stand up in front of the + + + align:start position:0% +I've got to stand up in front of the +president of the United States in a room + + align:start position:0% +president of the United States in a room + + + align:start position:0% +president of the United States in a room +much like this one only with about only + + align:start position:0% +much like this one only with about only + + + align:start position:0% +much like this one only with about only +10 or 12 people in it and tell that + + align:start position:0% +10 or 12 people in it and tell that + + + align:start position:0% +10 or 12 people in it and tell that +gentleman how you going to go to the + + align:start position:0% +gentleman how you going to go to the + + + align:start position:0% +gentleman how you going to go to the +moon and that was I I was a quick learn + + align:start position:0% +moon and that was I I was a quick learn + + + align:start position:0% +moon and that was I I was a quick learn +I'm telling you a really quick learn + + align:start position:0% +I'm telling you a really quick learn + + + align:start position:0% +I'm telling you a really quick learn +from people like these guys know John + + align:start position:0% +from people like these guys know John + + + align:start position:0% +from people like these guys know John +Mayor and Bill Tindle taught me in a few + + align:start position:0% +Mayor and Bill Tindle taught me in a few + + + align:start position:0% +Mayor and Bill Tindle taught me in a few +hours how to do the orbital mechanics to + + align:start position:0% +hours how to do the orbital mechanics to + + + align:start position:0% +hours how to do the orbital mechanics to +go to the Moon not how to do it but what + + align:start position:0% +go to the Moon not how to do it but what + + + align:start position:0% +go to the Moon not how to do it but what +took place so + + align:start position:0% +took place so + + + align:start position:0% +took place so +here we were at the end of mercury and + + align:start position:0% +here we were at the end of mercury and + + + align:start position:0% +here we were at the end of mercury and +we're going to then have to go go to the + + align:start position:0% +we're going to then have to go go to the + + + align:start position:0% +we're going to then have to go go to the +moon on how are we going to get there + + align:start position:0% +moon on how are we going to get there + + + align:start position:0% +moon on how are we going to get there +and how we going to train ourselves what + + align:start position:0% +and how we going to train ourselves what + + + align:start position:0% +and how we going to train ourselves what +are the systems we need to do the job + + align:start position:0% +are the systems we need to do the job + + + align:start position:0% +are the systems we need to do the job +what new control center do we need what + + align:start position:0% +what new control center do we need what + + + align:start position:0% +what new control center do we need what +kind of operations do we need to think + + align:start position:0% +kind of operations do we need to think + + + align:start position:0% +kind of operations do we need to think +about what kind of trajectory analysis + + align:start position:0% +about what kind of trajectory analysis + + + align:start position:0% +about what kind of trajectory analysis +do we need and what kind of computers do + + align:start position:0% +do we need and what kind of computers do + + + align:start position:0% +do we need and what kind of computers do +we need and what kind of communications + + align:start position:0% +we need and what kind of communications + + + align:start position:0% +we need and what kind of communications +do we need suddenly we've got a whole + + align:start position:0% +do we need suddenly we've got a whole + + + align:start position:0% +do we need suddenly we've got a whole +new set of problems we've got to if + + align:start position:0% +new set of problems we've got to if + + + align:start position:0% +new set of problems we've got to if +we're going to do Rendevous at the Moon + + align:start position:0% +we're going to do Rendevous at the Moon + + + align:start position:0% +we're going to do Rendevous at the Moon +we've got to teach ourselves how to do + + align:start position:0% +we've got to teach ourselves how to do + + + align:start position:0% +we've got to teach ourselves how to do +Rend at the Earth + + align:start position:0% +Rend at the Earth + + + align:start position:0% +Rend at the Earth +uh if we're going to send something + + align:start position:0% +uh if we're going to send something + + + align:start position:0% +uh if we're going to send something +around the Moon we better have a heck of + + align:start position:0% +around the Moon we better have a heck of + + + align:start position:0% +around the Moon we better have a heck of +a system to determine whether we are + + align:start position:0% +a system to determine whether we are + + + align:start position:0% +a system to determine whether we are +truly aiming at the moon or whether + + align:start position:0% +truly aiming at the moon or whether + + + align:start position:0% +truly aiming at the moon or whether +we're going to hit the moon and in fact + + align:start position:0% +we're going to hit the moon and in fact + + + align:start position:0% +we're going to hit the moon and in fact +on Apollo 8 I wasn't sure that George + + align:start position:0% +on Apollo 8 I wasn't sure that George + + + align:start position:0% +on Apollo 8 I wasn't sure that George +Miller who was ahead of man space flight + + align:start position:0% +Miller who was ahead of man space flight + + + align:start position:0% +Miller who was ahead of man space flight +was sure we weren't going to hit the + + align:start position:0% +was sure we weren't going to hit the + + + align:start position:0% +was sure we weren't going to hit the +moon when we told him that we wanted to + + align:start position:0% +moon when we told him that we wanted to + + + align:start position:0% +moon when we told him that we wanted to +repeat we wanted to do the trajectory as + + align:start position:0% +repeat we wanted to do the trajectory as + + + align:start position:0% +repeat we wanted to do the trajectory as +we were going to do it landed then you + + align:start position:0% +we were going to do it landed then you + + + align:start position:0% +we were going to do it landed then you +ended up being 60 miles above the lunar + + align:start position:0% +ended up being 60 miles above the lunar + + + align:start position:0% +ended up being 60 miles above the lunar +surface as you entered orbit around the + + align:start position:0% +surface as you entered orbit around the + + + align:start position:0% +surface as you entered orbit around the +moon + + align:start position:0% +moon + + + align:start position:0% +moon +and can you really tell me that 270,000 + + align:start position:0% +and can you really tell me that 270,000 + + + align:start position:0% +and can you really tell me that 270,000 +miles away whether the spacecraft is + + align:start position:0% +miles away whether the spacecraft is + + + align:start position:0% +miles away whether the spacecraft is +going to hit the moon when you're 10 + + align:start position:0% +going to hit the moon when you're 10 + + + align:start position:0% +going to hit the moon when you're 10 +hours away or is it going to go around + + align:start position:0% +hours away or is it going to go around + + + align:start position:0% +hours away or is it going to go around +in so we we're faced with all those new + + align:start position:0% +in so we we're faced with all those new + + + align:start position:0% +in so we we're faced with all those new +problems that's what got us to the gmany + + align:start position:0% +problems that's what got us to the gmany + + + align:start position:0% +problems that's what got us to the gmany +program we wanted to be able to build a + + align:start position:0% +program we wanted to be able to build a + + + align:start position:0% +program we wanted to be able to build a +spaceship that would allow us to do + + align:start position:0% +spaceship that would allow us to do + + + align:start position:0% +spaceship that would allow us to do +maneuvering in in orbit that would allow + + align:start position:0% +maneuvering in in orbit that would allow + + + align:start position:0% +maneuvering in in orbit that would allow +us to stay up there 14 days which is how + + align:start position:0% +us to stay up there 14 days which is how + + + align:start position:0% +us to stay up there 14 days which is how +long the spacecraft flight to the moon + + align:start position:0% +long the spacecraft flight to the moon + + + align:start position:0% +long the spacecraft flight to the moon +and back would be that would allow us to + + align:start position:0% +and back would be that would allow us to + + + align:start position:0% +and back would be that would allow us to +do uh re-entry guidance using yellow a d + + align:start position:0% +do uh re-entry guidance using yellow a d + + + align:start position:0% +do uh re-entry guidance using yellow a d +of a blunt body enough + + align:start position:0% +of a blunt body enough + + + align:start position:0% +of a blunt body enough +to uh skip it out as you came back to + + align:start position:0% +to uh skip it out as you came back to + + + align:start position:0% +to uh skip it out as you came back to +Earth and then go back up and then re + + align:start position:0% +Earth and then go back up and then re + + + align:start position:0% +Earth and then go back up and then re +enter at a at a much lower velocity so + + align:start position:0% +enter at a at a much lower velocity so + + + align:start position:0% +enter at a at a much lower velocity so +you wouldn't burn up spacecraft those + + align:start position:0% +you wouldn't burn up spacecraft those + + + align:start position:0% +you wouldn't burn up spacecraft those +are the kind of things we were suddenly + + align:start position:0% +are the kind of things we were suddenly + + + align:start position:0% +are the kind of things we were suddenly +thinking about as we built the germanes + + align:start position:0% +thinking about as we built the germanes + + + align:start position:0% +thinking about as we built the germanes +spacecraft we needed an onboard computer + + align:start position:0% +spacecraft we needed an onboard computer + + + align:start position:0% +spacecraft we needed an onboard computer +unheard + + align:start position:0% +unheard + + + align:start position:0% +unheard +of in that time period the Air Force had + + align:start position:0% +of in that time period the Air Force had + + + align:start position:0% +of in that time period the Air Force had +been putting some on airplanes but never + + align:start position:0% +been putting some on airplanes but never + + + align:start position:0% +been putting some on airplanes but never +had we had one on board a + + align:start position:0% +had we had one on board a + + + align:start position:0% +had we had one on board a +spacecraft so gmany was designed to be a + + align:start position:0% +spacecraft so gmany was designed to be a + + + align:start position:0% +spacecraft so gmany was designed to be a +maneuvering capable Onan space to + + align:start position:0% +maneuvering capable Onan space to + + + align:start position:0% +maneuvering capable Onan space to +Rendevous and dock with a Target to uh + + align:start position:0% +Rendevous and dock with a Target to uh + + + align:start position:0% +Rendevous and dock with a Target to uh +determine the capability of man to + + align:start position:0% +determine the capability of man to + + + align:start position:0% +determine the capability of man to +survive for 14 days to do + + align:start position:0% +survive for 14 days to do + + + align:start position:0% +survive for 14 days to do +a a heat shield which was much more + + align:start position:0% +a a heat shield which was much more + + + align:start position:0% +a a heat shield which was much more +flexible and + + align:start position:0% +flexible and + + + align:start position:0% +flexible and +reusable and to build a maneuvering + + align:start position:0% +reusable and to build a maneuvering + + + align:start position:0% +reusable and to build a maneuvering +system and finally to do guidance and + + align:start position:0% +system and finally to do guidance and + + + align:start position:0% +system and finally to do guidance and +control for landing Point control and + + align:start position:0% +control for landing Point control and + + + align:start position:0% +control for landing Point control and +develop a + + align:start position:0% +develop a + + + align:start position:0% +develop a +footprint on the earth for geminy which + + align:start position:0% +footprint on the earth for geminy which + + + align:start position:0% +footprint on the earth for geminy which +is what we were going to have to do on + + align:start position:0% +is what we were going to have to do on + + + align:start position:0% +is what we were going to have to do on +Apollo geminy was a very successful + + align:start position:0% +Apollo geminy was a very successful + + + align:start position:0% +Apollo geminy was a very successful +program without it we could never have + + align:start position:0% +program without it we could never have + + + align:start position:0% +program without it we could never have +gone to the Moon we learned how to + + align:start position:0% +gone to the Moon we learned how to + + + align:start position:0% +gone to the Moon we learned how to +operate in space how to maneuvering + + align:start position:0% +operate in space how to maneuvering + + + align:start position:0% +operate in space how to maneuvering +space we learned how to do Eva which was + + align:start position:0% +space we learned how to do Eva which was + + + align:start position:0% +space we learned how to do Eva which was +a total disaster as we flew in Germany I + + align:start position:0% +a total disaster as we flew in Germany I + + + align:start position:0% +a total disaster as we flew in Germany I +don't think we even even by doing doing + + align:start position:0% +don't think we even even by doing doing + + + align:start position:0% +don't think we even even by doing doing +it five or six times in uh on the final + + align:start position:0% +it five or six times in uh on the final + + + align:start position:0% +it five or six times in uh on the final +flight of Germany 12 Buzz aldr was able + + align:start position:0% +flight of Germany 12 Buzz aldr was able + + + align:start position:0% +flight of Germany 12 Buzz aldr was able +to do uh a ra a reasonable job in extra + + align:start position:0% +to do uh a ra a reasonable job in extra + + + align:start position:0% +to do uh a ra a reasonable job in extra +vehicular activity we had to build a + + align:start position:0% +vehicular activity we had to build a + + + align:start position:0% +vehicular activity we had to build a +suit that was flexible to be able to + + align:start position:0% +suit that was flexible to be able to + + + align:start position:0% +suit that was flexible to be able to +walk on the moon we had to build a + + align:start position:0% +walk on the moon we had to build a + + + align:start position:0% +walk on the moon we had to build a +backpack which would in truth was + + align:start position:0% +backpack which would in truth was + + + align:start position:0% +backpack which would in truth was +another spacecraft + + align:start position:0% +another spacecraft + + + align:start position:0% +another spacecraft +to do + + align:start position:0% + + + + align:start position:0% + +Apollo uh we had to build a new control + + align:start position:0% +Apollo uh we had to build a new control + + + align:start position:0% +Apollo uh we had to build a new control +center because we had a a a computer + + align:start position:0% +center because we had a a a computer + + + align:start position:0% +center because we had a a a computer +which we actually doubled the storage + + align:start position:0% +which we actually doubled the storage + + + align:start position:0% +which we actually doubled the storage +capacity on Mercury and then gave it + + align:start position:0% +capacity on Mercury and then gave it + + + align:start position:0% +capacity on Mercury and then gave it +60,000 64,000 + + align:start position:0% +60,000 64,000 + + + align:start position:0% +60,000 64,000 +words today you have that in some kids + + align:start position:0% +words today you have that in some kids + + + align:start position:0% +words today you have that in some kids +thing that he carries on his airplane + + align:start position:0% +thing that he carries on his airplane + + + align:start position:0% +thing that he carries on his airplane +and one touch of his throat but 64,000 + + align:start position:0% +and one touch of his throat but 64,000 + + + align:start position:0% +and one touch of his throat but 64,000 +words was all we had then when we flew + + align:start position:0% +words was all we had then when we flew + + + align:start position:0% +words was all we had then when we flew +Germany we had a million words when we + + align:start position:0% +Germany we had a million words when we + + + align:start position:0% +Germany we had a million words when we +flew Apollo we had five and a half + + align:start position:0% +flew Apollo we had five and a half + + + align:start position:0% +flew Apollo we had five and a half +million words so the computer complex + + align:start position:0% +million words so the computer complex + + + align:start position:0% +million words so the computer complex +was changing on as continuously when we + + align:start position:0% +was changing on as continuously when we + + + align:start position:0% +was changing on as continuously when we +did Mercury we used a grease pencil to + + align:start position:0% +did Mercury we used a grease pencil to + + + align:start position:0% +did Mercury we used a grease pencil to +write down the numbers as they came back + + align:start position:0% +write down the numbers as they came back + + + align:start position:0% +write down the numbers as they came back +from cono Nigerian 20 words of teletype + + align:start position:0% +from cono Nigerian 20 words of teletype + + + align:start position:0% +from cono Nigerian 20 words of teletype +we had to build a new display system and + + align:start position:0% +we had to build a new display system and + + + align:start position:0% +we had to build a new display system and +a digital display system with a computer + + align:start position:0% +a digital display system with a computer + + + align:start position:0% +a digital display system with a computer +and the first digital display system was + + align:start position:0% +and the first digital display system was + + + align:start position:0% +and the first digital display system was +not graphics at all what we did was + + align:start position:0% +not graphics at all what we did was + + + align:start position:0% +not graphics at all what we did was +build a a + + align:start position:0% +build a a + + + align:start position:0% +build a a +slide that was the background for the + + align:start position:0% +slide that was the background for the + + + align:start position:0% +slide that was the background for the +for the uh display that you wanted we + + align:start position:0% +for the uh display that you wanted we + + + align:start position:0% +for the uh display that you wanted we +had a set of you of uh 4 and a half inch + + align:start position:0% +had a set of you of uh 4 and a half inch + + + align:start position:0% +had a set of you of uh 4 and a half inch +Lantern slides a bank of 100 for each + + align:start position:0% +Lantern slides a bank of 100 for each + + + align:start position:0% +Lantern slides a bank of 100 for each +space each station in the control center + + align:start position:0% +space each station in the control center + + + align:start position:0% +space each station in the control center +and then the computer filled in the + + align:start position:0% +and then the computer filled in the + + + align:start position:0% +and then the computer filled in the +numbers now that's that's in 1964 65 66 + + align:start position:0% +numbers now that's that's in 1964 65 66 + + + align:start position:0% +numbers now that's that's in 1964 65 66 +it wasn't until we got to the latter + + align:start position:0% +it wasn't until we got to the latter + + + align:start position:0% +it wasn't until we got to the latter +stages of Follow that we had computer + + align:start position:0% +stages of Follow that we had computer + + + align:start position:0% +stages of Follow that we had computer +Graphics I don't know whether you can + + align:start position:0% +Graphics I don't know whether you can + + + align:start position:0% +Graphics I don't know whether you can +realize it that or not that's you know + + align:start position:0% +realize it that or not that's you know + + + align:start position:0% +realize it that or not that's you know +computer Graphics today is go football + + align:start position:0% +computer Graphics today is go football + + + align:start position:0% +computer Graphics today is go football +games on computer Graphics but then we + + align:start position:0% +games on computer Graphics but then we + + + align:start position:0% +games on computer Graphics but then we +didn't have it so we had to redesign a + + align:start position:0% +didn't have it so we had to redesign a + + + align:start position:0% +didn't have it so we had to redesign a +Control Center and continuously redesign + + align:start position:0% +Control Center and continuously redesign + + + align:start position:0% +Control Center and continuously redesign +a control center we had to have a + + align:start position:0% +a control center we had to have a + + + align:start position:0% +a control center we had to have a +computer control Communication + + align:start position:0% +computer control Communication + + + align:start position:0% +computer control Communication +System all of those things were built we + + align:start position:0% +System all of those things were built we + + + align:start position:0% +System all of those things were built we +had to utilize and build in NASA the + + align:start position:0% +had to utilize and build in NASA the + + + align:start position:0% +had to utilize and build in NASA the +first commun + + align:start position:0% +first commun + + + align:start position:0% +first commun +satellite from which came the revolution + + align:start position:0% +satellite from which came the revolution + + + align:start position:0% +satellite from which came the revolution +in the world in my + + align:start position:0% + + + + align:start position:0% + +opinion uh I want to I want to get + + align:start position:0% +opinion uh I want to I want to get + + + align:start position:0% +opinion uh I want to I want to get +to uh I could go through Apollo and + + align:start position:0% +to uh I could go through Apollo and + + + align:start position:0% +to uh I could go through Apollo and +things like TR trans lunar trajectories + + align:start position:0% +things like TR trans lunar trajectories + + + align:start position:0% +things like TR trans lunar trajectories +and free return trajectories and what H + + align:start position:0% +and free return trajectories and what H + + + align:start position:0% +and free return trajectories and what H +what might happen if you were off by a + + align:start position:0% +what might happen if you were off by a + + + align:start position:0% +what might happen if you were off by a +few feet per second or a few tents of a + + align:start position:0% +few feet per second or a few tents of a + + + align:start position:0% +few feet per second or a few tents of a +degree when you fired your + + align:start position:0% +degree when you fired your + + + align:start position:0% +degree when you fired your +uh uh orbital the the orbital + + align:start position:0% +uh uh orbital the the orbital + + + align:start position:0% +uh uh orbital the the orbital +maneuvering system of the APO on the + + align:start position:0% +maneuvering system of the APO on the + + + align:start position:0% +maneuvering system of the APO on the +back side of the moon which is where you + + align:start position:0% +back side of the moon which is where you + + + align:start position:0% +back side of the moon which is where you +had to do it for Optimum performance + + align:start position:0% +had to do it for Optimum performance + + + align:start position:0% +had to do it for Optimum performance +characteristics and when the thing + + align:start position:0% +characteristics and when the thing + + + align:start position:0% +characteristics and when the thing +showed up on the as it came out and view + + align:start position:0% +showed up on the as it came out and view + + + align:start position:0% +showed up on the as it came out and view +on the front side of the moon and it was + + align:start position:0% +on the front side of the moon and it was + + + align:start position:0% +on the front side of the moon and it was +right not in the right trajectory what + + align:start position:0% +right not in the right trajectory what + + + align:start position:0% +right not in the right trajectory what +the hell are you going to do about + + align:start position:0% +the hell are you going to do about + + + align:start position:0% +the hell are you going to do about +it where is it going is it going around + + align:start position:0% +it where is it going is it going around + + + align:start position:0% +it where is it going is it going around +the Sun + + align:start position:0% +the Sun + + + align:start position:0% +the Sun +is it coming back to Earth is it going + + align:start position:0% +is it coming back to Earth is it going + + + align:start position:0% +is it coming back to Earth is it going +to hit the + + align:start position:0% +to hit the + + + align:start position:0% +to hit the +Moon and what am I going to do about it + + align:start position:0% +Moon and what am I going to do about it + + + align:start position:0% +Moon and what am I going to do about it +if it is on one of those paths and my + + align:start position:0% +if it is on one of those paths and my + + + align:start position:0% +if it is on one of those paths and my +orbital my my maneuvering engine which + + align:start position:0% +orbital my my maneuvering engine which + + + align:start position:0% +orbital my my maneuvering engine which +has 10,000 PS of thrust is not working + + align:start position:0% +has 10,000 PS of thrust is not working + + + align:start position:0% +has 10,000 PS of thrust is not working +or not working properly or it wasn't + + align:start position:0% +or not working properly or it wasn't + + + align:start position:0% +or not working properly or it wasn't +pointed in the right direction you had + + align:start position:0% +pointed in the right direction you had + + + align:start position:0% +pointed in the right direction you had +to be prepared to think about those + + align:start position:0% +to be prepared to think about those + + + align:start position:0% +to be prepared to think about those +problems and make a real time + + align:start position:0% +problems and make a real time + + + align:start position:0% +problems and make a real time +decision as to what to do + + align:start position:0% +decision as to what to do + + + align:start position:0% +decision as to what to do +I hope I'm impressing you with that + + align:start position:0% +I hope I'm impressing you with that + + + align:start position:0% +I hope I'm impressing you with that +because that's what you guys are faced + + align:start position:0% +because that's what you guys are faced + + + align:start position:0% +because that's what you guys are faced +with in going back to the + + align:start position:0% +with in going back to the + + + align:start position:0% +with in going back to the +Moon you know it isn't just a simple + + align:start position:0% +Moon you know it isn't just a simple + + + align:start position:0% +Moon you know it isn't just a simple +problem of orbital mechanics it's a + + align:start position:0% +problem of orbital mechanics it's a + + + align:start position:0% +problem of orbital mechanics it's a +problem of what are you going to do if + + align:start position:0% +problem of what are you going to do if + + + align:start position:0% +problem of what are you going to do if +it isn't correct if it isn't on the + + align:start position:0% +it isn't correct if it isn't on the + + + align:start position:0% +it isn't correct if it isn't on the +right path if the system isn't working + + align:start position:0% +right path if the system isn't working + + + align:start position:0% +right path if the system isn't working +properly can you + + align:start position:0% +properly can you + + + align:start position:0% +properly can you +land those things have to be thought out + + align:start position:0% +land those things have to be thought out + + + align:start position:0% +land those things have to be thought out +and thought out carefully before for the + + align:start position:0% +and thought out carefully before for the + + + align:start position:0% +and thought out carefully before for the +fact not in real time you can make all + + align:start position:0% +fact not in real time you can make all + + + align:start position:0% +fact not in real time you can make all +of the decisions in the computer which + + align:start position:0% +of the decisions in the computer which + + + align:start position:0% +of the decisions in the computer which +you would have made after you thought + + align:start position:0% +you would have made after you thought + + + align:start position:0% +you would have made after you thought +about it in real time but think of the + + align:start position:0% +about it in real time but think of the + + + align:start position:0% +about it in real time but think of the +orbital mechanics problems associated + + align:start position:0% +orbital mechanics problems associated + + + align:start position:0% +orbital mechanics problems associated +with + + align:start position:0% +with + + + align:start position:0% +with +that in real time and the back + + align:start position:0% +that in real time and the back + + + align:start position:0% +that in real time and the back +background then of the math and the + + align:start position:0% +background then of the math and the + + + align:start position:0% +background then of the math and the +thought processes that have to go into + + align:start position:0% +thought processes that have to go into + + + align:start position:0% +thought processes that have to go into +making those + + align:start position:0% +making those + + + align:start position:0% +making those +decisions you're descending to the moon + + align:start position:0% +decisions you're descending to the moon + + + align:start position:0% +decisions you're descending to the moon +and there one of these gentlemen sitting + + align:start position:0% +and there one of these gentlemen sitting + + + align:start position:0% +and there one of these gentlemen sitting +here you start to do the uh the + + align:start position:0% +here you start to do the uh the + + + align:start position:0% +here you start to do the uh the +uh descent to the + + align:start position:0% +uh descent to the + + + align:start position:0% +uh descent to the +moon and lo and behold you bring up the + + align:start position:0% +moon and lo and behold you bring up the + + + align:start position:0% +moon and lo and behold you bring up the +system on the limb and the abort light + + align:start position:0% +system on the limb and the abort light + + + align:start position:0% +system on the limb and the abort light +is + + align:start position:0% +is + + + align:start position:0% +is +on and what the hell does that mean well + + align:start position:0% +on and what the hell does that mean well + + + align:start position:0% +on and what the hell does that mean well +it means if you start the engine right + + align:start position:0% +it means if you start the engine right + + + align:start position:0% +it means if you start the engine right +now it's going to start doing a randev + + align:start position:0% +now it's going to start doing a randev + + + align:start position:0% +now it's going to start doing a randev +back with the Command Module it's not + + align:start position:0% +back with the Command Module it's not + + + align:start position:0% +back with the Command Module it's not +going to land on the lunar + + align:start position:0% +going to land on the lunar + + + align:start position:0% +going to land on the lunar +surface and I've got a computer program + + align:start position:0% +surface and I've got a computer program + + + align:start position:0% +surface and I've got a computer program +that's hard + + align:start position:0% +that's hard + + + align:start position:0% +that's hard +wired to do that job with I don't have + + align:start position:0% +wired to do that job with I don't have + + + align:start position:0% +wired to do that job with I don't have +the capability of reprogramming it like + + align:start position:0% +the capability of reprogramming it like + + + align:start position:0% +the capability of reprogramming it like +you have by just sending up a whole new + + align:start position:0% +you have by just sending up a whole new + + + align:start position:0% +you have by just sending up a whole new +set of software how am I going to figure + + align:start position:0% +set of software how am I going to figure + + + align:start position:0% +set of software how am I going to figure +that damn thing out I've got a thir + + align:start position:0% +that damn thing out I've got a thir + + + align:start position:0% +that damn thing out I've got a thir +thousand words of pad in this + + align:start position:0% +thousand words of pad in this + + + align:start position:0% +thousand words of pad in this +computer is it possible + + align:start position:0% +computer is it possible + + + align:start position:0% +computer is it possible +in real time to obviate that abort + + align:start position:0% +in real time to obviate that abort + + + align:start position:0% +in real time to obviate that abort +signal and still land on the + + align:start position:0% +signal and still land on the + + + align:start position:0% +signal and still land on the +moon and this gentleman sitting over + + align:start position:0% +moon and this gentleman sitting over + + + align:start position:0% +moon and this gentleman sitting over +here figured that + + align:start position:0% +here figured that + + + align:start position:0% +here figured that +out he's figured out how to tell the + + align:start position:0% +out he's figured out how to tell the + + + align:start position:0% +out he's figured out how to tell the +computer ignore that + + align:start position:0% +computer ignore that + + + align:start position:0% +computer ignore that +signal by going into the certain places + + align:start position:0% +signal by going into the certain places + + + align:start position:0% +signal by going into the certain places +in the software in that hardwired + + align:start position:0% +in the software in that hardwired + + + align:start position:0% +in the software in that hardwired +software and saying don't listen to the + + align:start position:0% +software and saying don't listen to the + + + align:start position:0% +software and saying don't listen to the +abort signal for a + + align:start position:0% +abort signal for a + + + align:start position:0% +abort signal for a +while don't listen to it but if I need + + align:start position:0% +while don't listen to it but if I need + + + align:start position:0% +while don't listen to it but if I need +to listen to it on the way down then + + align:start position:0% +to listen to it on the way down then + + + align:start position:0% +to listen to it on the way down then +listen to it and you got to do that with + + align:start position:0% +listen to it and you got to do that with + + + align:start position:0% +listen to it and you got to do that with +a thousand words that's pretty tough + + align:start position:0% +a thousand words that's pretty tough + + + align:start position:0% +a thousand words that's pretty tough +problem in real time one which nobody + + align:start position:0% +problem in real time one which nobody + + + align:start position:0% +problem in real time one which nobody +had thought about + + align:start position:0% +had thought about + + + align:start position:0% +had thought about +before until it + + align:start position:0% +before until it + + + align:start position:0% +before until it +happened or as I said this 25 year old + + align:start position:0% +happened or as I said this 25 year old + + + align:start position:0% +happened or as I said this 25 year old +young man on Apollo 11 and the vehicles + + align:start position:0% +young man on Apollo 11 and the vehicles + + + align:start position:0% +young man on Apollo 11 and the vehicles +are descending to the moon and he's + + align:start position:0% +are descending to the moon and he's + + + align:start position:0% +are descending to the moon and he's +getting all these signals back that says + + align:start position:0% +getting all these signals back that says + + + align:start position:0% +getting all these signals back that says +the computer is over loaded and it's + + align:start position:0% +the computer is over loaded and it's + + + align:start position:0% +the computer is over loaded and it's +doing so many tasks and + + align:start position:0% +doing so many tasks and + + + align:start position:0% +doing so many tasks and +stopping why is it doing that we've done + + align:start position:0% +stopping why is it doing that we've done + + + align:start position:0% +stopping why is it doing that we've done +it on Apollo a 10 when we started down + + align:start position:0% +it on Apollo a 10 when we started down + + + align:start position:0% +it on Apollo a 10 when we started down +to the moon and worked fine and we did a + + align:start position:0% +to the moon and worked fine and we did a + + + align:start position:0% +to the moon and worked fine and we did a +Rendevous from it but we had to radar + + align:start position:0% +Rendevous from it but we had to radar + + + align:start position:0% +Rendevous from it but we had to radar +on and going down to the Moon we didn't + + align:start position:0% +on and going down to the Moon we didn't + + + align:start position:0% +on and going down to the Moon we didn't +need the radar on and that radar was + + align:start position:0% +need the radar on and that radar was + + + align:start position:0% +need the radar on and that radar was +going into the computer was flooding the + + align:start position:0% +going into the computer was flooding the + + + align:start position:0% +going into the computer was flooding the +computer with data but these guys didn't + + align:start position:0% +computer with data but these guys didn't + + + align:start position:0% +computer with data but these guys didn't +know that they had to figure out how to + + align:start position:0% +know that they had to figure out how to + + + align:start position:0% +know that they had to figure out how to +get around that signal + + align:start position:0% +get around that signal + + + align:start position:0% +get around that signal +if I if I sound like that's a big + + align:start position:0% +if I if I sound like that's a big + + + align:start position:0% +if I if I sound like that's a big +problem it is a big + + align:start position:0% +problem it is a big + + + align:start position:0% +problem it is a big +problem and it's going to get bigger the + + align:start position:0% +problem and it's going to get bigger the + + + align:start position:0% +problem and it's going to get bigger the +spacecraft are going to get more + + align:start position:0% +spacecraft are going to get more + + + align:start position:0% +spacecraft are going to get more +complex with each passing day and you're + + align:start position:0% +complex with each passing day and you're + + + align:start position:0% +complex with each passing day and you're +going to have to figure out how to do + + align:start position:0% +going to have to figure out how to do + + + align:start position:0% +going to have to figure out how to do +that stuff in real time and that's what + + align:start position:0% +that stuff in real time and that's what + + + align:start position:0% +that stuff in real time and that's what +you the flight operations people and the + + align:start position:0% +you the flight operations people and the + + + align:start position:0% +you the flight operations people and the +designers of Tomorrow are going to be + + align:start position:0% +designers of Tomorrow are going to be + + + align:start position:0% +designers of Tomorrow are going to be +and that's what you're going to be fac + + align:start position:0% +and that's what you're going to be fac + + + align:start position:0% +and that's what you're going to be fac +with uh I know you're + + align:start position:0% +with uh I know you're + + + align:start position:0% +with uh I know you're +I'm working on the + + align:start position:0% +I'm working on the + + + align:start position:0% +I'm working on the +uh space shuttle try to make it better + + align:start position:0% +uh space shuttle try to make it better + + + align:start position:0% +uh space shuttle try to make it better +that's what your task is in this + + align:start position:0% +that's what your task is in this + + + align:start position:0% +that's what your task is in this +class + + align:start position:0% +class + + + align:start position:0% +class +uh we should have had you around for the + + align:start position:0% +uh we should have had you around for the + + + align:start position:0% +uh we should have had you around for the +last 25 + + align:start position:0% +last 25 + + + align:start position:0% +last 25 +years because it needs to be made + + align:start position:0% +years because it needs to be made + + + align:start position:0% +years because it needs to be made +better and it's a travesty I use a I'll + + align:start position:0% +better and it's a travesty I use a I'll + + + align:start position:0% +better and it's a travesty I use a I'll +use that word again it's a travesty that + + align:start position:0% +use that word again it's a travesty that + + + align:start position:0% +use that word again it's a travesty that +we haven't been making it better + + align:start position:0% +we haven't been making it better + + + align:start position:0% +we haven't been making it better +and making it less costly to + + align:start position:0% +and making it less costly to + + + align:start position:0% +and making it less costly to +fly we should have been doing that so + + align:start position:0% +fly we should have been doing that so + + + align:start position:0% +fly we should have been doing that so +let me start into the space shuttle a + + align:start position:0% +let me start into the space shuttle a + + + align:start position:0% +let me start into the space shuttle a +little + + align:start position:0% + + + + align:start position:0% + +uh one one of the questions that Jeff + + align:start position:0% +uh one one of the questions that Jeff + + + align:start position:0% +uh one one of the questions that Jeff +asked me that these people will be + + align:start position:0% +asked me that these people will be + + + align:start position:0% +asked me that these people will be +interested in uh in hearing is uh how + + align:start position:0% +interested in uh in hearing is uh how + + + align:start position:0% +interested in uh in hearing is uh how +did you decide to do it Mann as opposed + + align:start position:0% +did you decide to do it Mann as opposed + + + align:start position:0% +did you decide to do it Mann as opposed +to unmanned on the first + + align:start position:0% + + + + align:start position:0% + +flight + + align:start position:0% +flight + + + align:start position:0% +flight +uh sort of out of necessity I guess you + + align:start position:0% +uh sort of out of necessity I guess you + + + align:start position:0% +uh sort of out of necessity I guess you +would + + align:start position:0% +would + + + align:start position:0% +would +say we the more we looked at the systems + + align:start position:0% +say we the more we looked at the systems + + + align:start position:0% +say we the more we looked at the systems +the we the more we looked at the Space + + align:start position:0% +the we the more we looked at the Space + + + align:start position:0% +the we the more we looked at the Space +Shuttle more we realized that the man + + align:start position:0% +Shuttle more we realized that the man + + + align:start position:0% +Shuttle more we realized that the man +could furnish us a certain amount of + + align:start position:0% +could furnish us a certain amount of + + + align:start position:0% +could furnish us a certain amount of +reliability in space operations and in + + align:start position:0% +reliability in space operations and in + + + align:start position:0% +reliability in space operations and in +Bas systems and choosing + + align:start position:0% +Bas systems and choosing + + + align:start position:0% +Bas systems and choosing +systems the the more reliable the + + align:start position:0% +systems the the more reliable the + + + align:start position:0% +systems the the more reliable the +machine would become but we had to + + align:start position:0% +machine would become but we had to + + + align:start position:0% +machine would become but we had to +convince ourselves that that was a + + align:start position:0% +convince ourselves that that was a + + + align:start position:0% +convince ourselves that that was a +rational thing to do now let's let's go + + align:start position:0% +rational thing to do now let's let's go + + + align:start position:0% +rational thing to do now let's let's go +back and and give you some thought + + align:start position:0% +back and and give you some thought + + + align:start position:0% +back and and give you some thought +process about the space shuttle + + align:start position:0% +process about the space shuttle + + + align:start position:0% +process about the space shuttle +design as we did the initial design we + + align:start position:0% +design as we did the initial design we + + + align:start position:0% +design as we did the initial design we +wanted an escape + + align:start position:0% +wanted an escape + + + align:start position:0% +wanted an escape +system we wanted to build a pod + + align:start position:0% +system we wanted to build a pod + + + align:start position:0% +system we wanted to build a pod +into the uh cockpit to allow the + + align:start position:0% +into the uh cockpit to allow the + + + align:start position:0% +into the uh cockpit to allow the +astronauts to escape if we had problems + + align:start position:0% +astronauts to escape if we had problems + + + align:start position:0% +astronauts to escape if we had problems +and because the building the sh space + + align:start position:0% +and because the building the sh space + + + align:start position:0% +and because the building the sh space +shuttle main engine was very + + align:start position:0% +shuttle main engine was very + + + align:start position:0% +shuttle main engine was very +difficult these people know about subn + + align:start position:0% +difficult these people know about subn + + + align:start position:0% +difficult these people know about subn +Subs synchronous + + align:start position:0% +Subs synchronous + + + align:start position:0% +Subs synchronous +world uh you couldn't we couldn't find + + align:start position:0% +world uh you couldn't we couldn't find + + + align:start position:0% +world uh you couldn't we couldn't find +any berries in the world that would + + align:start position:0% +any berries in the world that would + + + align:start position:0% +any berries in the world that would +withstand that load they were they were + + align:start position:0% +withstand that load they were they were + + + align:start position:0% +withstand that load they were they were +failing and you didn't know when they + + align:start position:0% +failing and you didn't know when they + + + align:start position:0% +failing and you didn't know when they +were going to fail so we had we built a + + align:start position:0% +were going to fail so we had we built a + + + align:start position:0% +were going to fail so we had we built a +uh automatic shutdown system into the uh + + align:start position:0% +uh automatic shutdown system into the uh + + + align:start position:0% +uh automatic shutdown system into the uh +engine and the auto that's eron and I + + align:start position:0% +engine and the auto that's eron and I + + + align:start position:0% +engine and the auto that's eron and I +were talking about that this morning Mr + + align:start position:0% +were talking about that this morning Mr + + + align:start position:0% +were talking about that this morning Mr +Cen Professor Cohen and uh you know that + + align:start position:0% +Cen Professor Cohen and uh you know that + + + align:start position:0% +Cen Professor Cohen and uh you know that +that sounds well we'll just figure out + + align:start position:0% +that sounds well we'll just figure out + + + align:start position:0% +that sounds well we'll just figure out +what all the parameters are that tell + + align:start position:0% +what all the parameters are that tell + + + align:start position:0% +what all the parameters are that tell +you when the engine is malfunctioning + + align:start position:0% +you when the engine is malfunctioning + + + align:start position:0% +you when the engine is malfunctioning +and shut it down because we don't want + + align:start position:0% +and shut it down because we don't want + + + align:start position:0% +and shut it down because we don't want +it to blow up so we're going to look at + + align:start position:0% +it to blow up so we're going to look at + + + align:start position:0% +it to blow up so we're going to look at +RPM of the pumps and we're going to look + + align:start position:0% +RPM of the pumps and we're going to look + + + align:start position:0% +RPM of the pumps and we're going to look +at temperature in the so going to look + + align:start position:0% +at temperature in the so going to look + + + align:start position:0% +at temperature in the so going to look +at the pressure in the in the in the + + align:start position:0% +at the pressure in the in the in the + + + align:start position:0% +at the pressure in the in the in the +engine head and we're going to look at + + align:start position:0% +engine head and we're going to look at + + + align:start position:0% +engine head and we're going to look at +the fuel flow rates etc etc that sounds + + align:start position:0% +the fuel flow rates etc etc that sounds + + + align:start position:0% +the fuel flow rates etc etc that sounds +like well we could do that but how do + + align:start position:0% +like well we could do that but how do + + + align:start position:0% +like well we could do that but how do +you know it's + + align:start position:0% +you know it's + + + align:start position:0% +you know it's +right how do you know you're not + + align:start position:0% +right how do you know you're not + + + align:start position:0% +right how do you know you're not +shutting down a good engine and the + + align:start position:0% +shutting down a good engine and the + + + align:start position:0% +shutting down a good engine and the +point I'm making there is the + + align:start position:0% +point I'm making there is the + + + align:start position:0% +point I'm making there is the +reliability of the instrument becomes + + align:start position:0% +reliability of the instrument becomes + + + align:start position:0% +reliability of the instrument becomes +more important than the + + align:start position:0% +more important than the + + + align:start position:0% +more important than the +engine think about that so you can well + + align:start position:0% +engine think about that so you can well + + + align:start position:0% +engine think about that so you can well +I'll have I'll have an automatic shut + + align:start position:0% +I'll have I'll have an automatic shut + + + align:start position:0% +I'll have I'll have an automatic shut +down have the automatic abort get it get + + align:start position:0% +down have the automatic abort get it get + + + align:start position:0% +down have the automatic abort get it get +the astronaut away but you got to some + + align:start position:0% +the astronaut away but you got to some + + + align:start position:0% +the astronaut away but you got to some +something's got to make that decision + + align:start position:0% +something's got to make that decision + + + align:start position:0% +something's got to make that decision +nobody on the ground can do it fast + + align:start position:0% +nobody on the ground can do it fast + + + align:start position:0% +nobody on the ground can do it fast +enough Dr if the engine's going to blow + + align:start position:0% +enough Dr if the engine's going to blow + + + align:start position:0% +enough Dr if the engine's going to blow +up astronaut can't do it his reaction + + align:start position:0% +up astronaut can't do it his reaction + + + align:start position:0% +up astronaut can't do it his reaction +time is about one and a half seconds no + + align:start position:0% +time is about one and a half seconds no + + + align:start position:0% +time is about one and a half seconds no +matter how much data you give him or how + + align:start position:0% +matter how much data you give him or how + + + align:start position:0% +matter how much data you give him or how +good the data is so it's got to be + + align:start position:0% +good the data is so it's got to be + + + align:start position:0% +good the data is so it's got to be +automatic and that's a that's a very + + align:start position:0% +automatic and that's a that's a very + + + align:start position:0% +automatic and that's a that's a very +difficult task for an engineer he can + + align:start position:0% +difficult task for an engineer he can + + + align:start position:0% +difficult task for an engineer he can +make the system work + + align:start position:0% +make the system work + + + align:start position:0% +make the system work +but he can't tell you very + + align:start position:0% +but he can't tell you very + + + align:start position:0% +but he can't tell you very +rapidly when it's going to + + align:start position:0% +rapidly when it's going to + + + align:start position:0% +rapidly when it's going to +fail and and Rocket engines have a bad + + align:start position:0% +fail and and Rocket engines have a bad + + + align:start position:0% +fail and and Rocket engines have a bad +nasty habit of going like that and it's + + align:start position:0% + + + + align:start position:0% + +gone you got to figure out when that's + + align:start position:0% +gone you got to figure out when that's + + + align:start position:0% +gone you got to figure out when that's +going to happen so designing + + align:start position:0% +going to happen so designing + + + align:start position:0% +going to happen so designing +instrumentation to do that we then + + align:start position:0% +instrumentation to do that we then + + + align:start position:0% +instrumentation to do that we then +started thinking about that in + + align:start position:0% +started thinking about that in + + + align:start position:0% +started thinking about that in +application to the Space + + align:start position:0% +application to the Space + + + align:start position:0% +application to the Space +Shuttle and as our our experience with + + align:start position:0% +Shuttle and as our our experience with + + + align:start position:0% +Shuttle and as our our experience with +redundancy reliability numbers thinking + + align:start position:0% +redundancy reliability numbers thinking + + + align:start position:0% +redundancy reliability numbers thinking +about + + align:start position:0% +about + + + align:start position:0% +about +that we said we want a system in the + + align:start position:0% +that we said we want a system in the + + + align:start position:0% +that we said we want a system in the +shuttle that's going to be fail + + align:start position:0% +shuttle that's going to be fail + + + align:start position:0% +shuttle that's going to be fail +operational fail + + align:start position:0% +operational fail + + + align:start position:0% +operational fail +operational fail + + align:start position:0% +operational fail + + + align:start position:0% +operational fail +safe that's quad + + align:start position:0% +safe that's quad + + + align:start position:0% +safe that's quad +redundancy so every critical + + align:start position:0% +redundancy so every critical + + + align:start position:0% +redundancy so every critical +system has quad redundancy in the space + + align:start position:0% +system has quad redundancy in the space + + + align:start position:0% +system has quad redundancy in the space +shuttle that sounds like a good idea + + align:start position:0% +shuttle that sounds like a good idea + + + align:start position:0% +shuttle that sounds like a good idea +doesn't it come back to that in a + + align:start position:0% +doesn't it come back to that in a + + + align:start position:0% +doesn't it come back to that in a +minute we said we would like to have a + + align:start position:0% +minute we said we would like to have a + + + align:start position:0% +minute we said we would like to have a +Escape + + align:start position:0% +Escape + + + align:start position:0% +Escape +pod but the Escape pod has got to have a + + align:start position:0% +pod but the Escape pod has got to have a + + + align:start position:0% +pod but the Escape pod has got to have a +stability and control system it's got to + + align:start position:0% +stability and control system it's got to + + + align:start position:0% +stability and control system it's got to +have a control system because it's going + + align:start position:0% +have a control system because it's going + + + align:start position:0% +have a control system because it's going +to be a spacecraft when is it going to + + align:start position:0% +to be a spacecraft when is it going to + + + align:start position:0% +to be a spacecraft when is it going to +use the Pod is the Pod going to be used + + align:start position:0% +use the Pod is the Pod going to be used + + + align:start position:0% +use the Pod is the Pod going to be used +at 100 feet off the pad 100,000 ft off + + align:start position:0% +at 100 feet off the pad 100,000 ft off + + + align:start position:0% +at 100 feet off the pad 100,000 ft off +the pad + + align:start position:0% +the pad + + + align:start position:0% +the pad +500,000 ft off the + + align:start position:0% +500,000 ft off the + + + align:start position:0% +500,000 ft off the +path and if this thing is descending + + align:start position:0% +path and if this thing is descending + + + align:start position:0% +path and if this thing is descending +from any one of those altitudes how are + + align:start position:0% +from any one of those altitudes how are + + + align:start position:0% +from any one of those altitudes how are +you going to control + + align:start position:0% +you going to control + + + align:start position:0% +you going to control +it very rapidly that's another + + align:start position:0% +it very rapidly that's another + + + align:start position:0% +it very rapidly that's another +spacecraft it's probably a bigger job in + + align:start position:0% +spacecraft it's probably a bigger job in + + + align:start position:0% +spacecraft it's probably a bigger job in +building that spacecraft than building + + align:start position:0% +building that spacecraft than building + + + align:start position:0% +building that spacecraft than building +the space shuttle + + align:start position:0% +the space shuttle + + + align:start position:0% +the space shuttle +itself so you can see why we didn't do + + align:start position:0% +itself so you can see why we didn't do + + + align:start position:0% +itself so you can see why we didn't do +it too tough too big a + + align:start position:0% +it too tough too big a + + + align:start position:0% +it too tough too big a +job we said we'd like to have a go round + + align:start position:0% +job we said we'd like to have a go round + + + align:start position:0% +job we said we'd like to have a go round +capability on this + + align:start position:0% +capability on this + + + align:start position:0% +capability on this +machine uh it's going to have a l of + + align:start position:0% +machine uh it's going to have a l of + + + align:start position:0% +machine uh it's going to have a l of +about four to five at the at best and + + align:start position:0% +about four to five at the at best and + + + align:start position:0% +about four to five at the at best and +The Descent angle that you come that you + + align:start position:0% +The Descent angle that you come that you + + + align:start position:0% +The Descent angle that you come that you +come down to land is 23 + + align:start position:0% +come down to land is 23 + + + align:start position:0% +come down to land is 23 +degrees let me tell you something I have + + align:start position:0% +degrees let me tell you something I have + + + align:start position:0% +degrees let me tell you something I have +flown in a Gulf Stream 2 on a 23 degree + + align:start position:0% +flown in a Gulf Stream 2 on a 23 degree + + + align:start position:0% +flown in a Gulf Stream 2 on a 23 degree +descent trajectory and that is scary as + + align:start position:0% +descent trajectory and that is scary as + + + align:start position:0% +descent trajectory and that is scary as +hell you're flying a + + align:start position:0% +hell you're flying a + + + align:start position:0% +hell you're flying a +that machine is coming down like that + + align:start position:0% +that machine is coming down like that + + + align:start position:0% +that machine is coming down like that +and you're you've got you're hanging on + + align:start position:0% +and you're you've got you're hanging on + + + align:start position:0% +and you're you've got you're hanging on +your + + align:start position:0% + + + + align:start position:0% + +straps so we'd like to be able to have a + + align:start position:0% +straps so we'd like to be able to have a + + + align:start position:0% +straps so we'd like to be able to have a +go around capability so okay we'll put + + align:start position:0% +go around capability so okay we'll put + + + align:start position:0% +go around capability so okay we'll put +some jet engines on it it's got to have + + align:start position:0% +some jet engines on it it's got to have + + + align:start position:0% +some jet engines on it it's got to have +fuel it's got to have a tank I got a + + align:start position:0% +fuel it's got to have a tank I got a + + + align:start position:0% +fuel it's got to have a tank I got a +lines on it got to have a certain amount + + align:start position:0% +lines on it got to have a certain amount + + + align:start position:0% +lines on it got to have a certain amount +of redundancy with it certain amount of + + align:start position:0% +of redundancy with it certain amount of + + + align:start position:0% +of redundancy with it certain amount of +power it's got to be absorbed into the + + align:start position:0% +power it's got to be absorbed into the + + + align:start position:0% +power it's got to be absorbed into the +thermal protection system and come out + + align:start position:0% +thermal protection system and come out + + + align:start position:0% +thermal protection system and come out +extend when I want to do this go around + + align:start position:0% +extend when I want to do this go around + + + align:start position:0% +extend when I want to do this go around +as I'm reentering some space so I can go + + align:start position:0% +as I'm reentering some space so I can go + + + align:start position:0% +as I'm reentering some space so I can go +once around the the runway and + + align:start position:0% +once around the the runway and + + + align:start position:0% +once around the the runway and +land it didn't take us long to figure + + align:start position:0% +land it didn't take us long to figure + + + align:start position:0% +land it didn't take us long to figure +out if we built that system we couldn't + + align:start position:0% +out if we built that system we couldn't + + + align:start position:0% +out if we built that system we couldn't +carry a damn pound into + + align:start position:0% +carry a damn pound into + + + align:start position:0% +carry a damn pound into +orbit there went our + + align:start position:0% + + + + align:start position:0% + +payload and we very rapidly started + + align:start position:0% +payload and we very rapidly started + + + align:start position:0% +payload and we very rapidly started +figuring how to do Ted Dead stick + + align:start position:0% +figuring how to do Ted Dead stick + + + align:start position:0% +figuring how to do Ted Dead stick +Landings and how to preserve the energy + + align:start position:0% +Landings and how to preserve the energy + + + align:start position:0% +Landings and how to preserve the energy +and how to get this machine lined up on + + align:start position:0% +and how to get this machine lined up on + + + align:start position:0% +and how to get this machine lined up on +the runway at way high altitudes and etc + + align:start position:0% +the runway at way high altitudes and etc + + + align:start position:0% +the runway at way high altitudes and etc +etc so we did away with the gound + + align:start position:0% +etc so we did away with the gound + + + align:start position:0% +etc so we did away with the gound +capability we've done away with the Pod + + align:start position:0% +capability we've done away with the Pod + + + align:start position:0% +capability we've done away with the Pod +done away with the go around capability + + align:start position:0% +done away with the go around capability + + + align:start position:0% +done away with the go around capability +now we don't have an escape + + align:start position:0% +now we don't have an escape + + + align:start position:0% +now we don't have an escape +system what is your Escape system on the + + align:start position:0% +system what is your Escape system on the + + + align:start position:0% +system what is your Escape system on the +shuttle well on Mercury and Apollo the + + align:start position:0% +shuttle well on Mercury and Apollo the + + + align:start position:0% +shuttle well on Mercury and Apollo the +Escape system is a solid rocket + + align:start position:0% +Escape system is a solid rocket + + + align:start position:0% +Escape system is a solid rocket +solid Rockets + + align:start position:0% +solid Rockets + + + align:start position:0% +solid Rockets +have close to 100% reliability as you + + align:start position:0% +have close to 100% reliability as you + + + align:start position:0% +have close to 100% reliability as you +can get usually if you if it lights it + + align:start position:0% +can get usually if you if it lights it + + + align:start position:0% +can get usually if you if it lights it +burns and it + + align:start position:0% +burns and it + + + align:start position:0% +burns and it +goes God we got two solid rockets on the + + align:start position:0% +goes God we got two solid rockets on the + + + align:start position:0% +goes God we got two solid rockets on the +shuttle why aren't they our Escape + + align:start position:0% +shuttle why aren't they our Escape + + + align:start position:0% +shuttle why aren't they our Escape +system because if we can get this thing + + align:start position:0% +system because if we can get this thing + + + align:start position:0% +system because if we can get this thing +to 200,000 ft it'll + + align:start position:0% +to 200,000 ft it'll + + + align:start position:0% +to 200,000 ft it'll +fly so we can return to the launch site + + align:start position:0% +fly so we can return to the launch site + + + align:start position:0% +fly so we can return to the launch site +and land from 200,000 feet because you + + align:start position:0% +and land from 200,000 feet because you + + + align:start position:0% +and land from 200,000 feet because you +very far down range at 200,000 ft God + + align:start position:0% +very far down range at 200,000 ft God + + + align:start position:0% +very far down range at 200,000 ft God +that's a good + + align:start position:0% +that's a good + + + align:start position:0% +that's a good +idea great + + align:start position:0% +idea great + + + align:start position:0% +idea great +idea but the Rockets have to be 100% + + align:start position:0% + + + + align:start position:0% + +reliable wasn't 100% reliable on the + + align:start position:0% +reliable wasn't 100% reliable on the + + + align:start position:0% +reliable wasn't 100% reliable on the +Challenger + + align:start position:0% +Challenger + + + align:start position:0% +Challenger +accident I can't account I can't + + align:start position:0% +accident I can't account I can't + + + align:start position:0% +accident I can't account I can't +account unfortunately I cannot account + + align:start position:0% +account unfortunately I cannot account + + + align:start position:0% +account unfortunately I cannot account +for the fallacies of man + + align:start position:0% +for the fallacies of man + + + align:start position:0% +for the fallacies of man +I'll come back to that if you want me to + + align:start position:0% +I'll come back to that if you want me to + + + align:start position:0% +I'll come back to that if you want me to +talk about the Char tracks but we built + + align:start position:0% +talk about the Char tracks but we built + + + align:start position:0% +talk about the Char tracks but we built +the solid Rockets to have 100% + + align:start position:0% +the solid Rockets to have 100% + + + align:start position:0% +the solid Rockets to have 100% +reliability and they were our Escape + + align:start position:0% +reliability and they were our Escape + + + align:start position:0% +reliability and they were our Escape +rocket so we've got quad + + align:start position:0% +rocket so we've got quad + + + align:start position:0% +rocket so we've got quad +redundancy we've + + align:start position:0% +redundancy we've + + + align:start position:0% +redundancy we've +got uh engines that will perform to the + + align:start position:0% +got uh engines that will perform to the + + + align:start position:0% +got uh engines that will perform to the +best of our ability and shut down if + + align:start position:0% +best of our ability and shut down if + + + align:start position:0% +best of our ability and shut down if +they are going to explode we got solid + + align:start position:0% +they are going to explode we got solid + + + align:start position:0% +they are going to explode we got solid +Rockets as a as a Escape system + + align:start position:0% +Rockets as a as a Escape system + + + align:start position:0% +Rockets as a as a Escape system +and we will teach the pilots with the + + align:start position:0% +and we will teach the pilots with the + + + align:start position:0% +and we will teach the pilots with the +best control system we can come up with + + align:start position:0% +best control system we can come up with + + + align:start position:0% +best control system we can come up with +to land this machine Dead + + align:start position:0% + + + + align:start position:0% + +stick now we got to convince ourselves + + align:start position:0% +stick now we got to convince ourselves + + + align:start position:0% +stick now we got to convince ourselves +and the management that the best way to + + align:start position:0% +and the management that the best way to + + + align:start position:0% +and the management that the best way to +fly this thing is + + align:start position:0% +fly this thing is + + + align:start position:0% +fly this thing is +unmaned or manned on the first + + align:start position:0% +unmaned or manned on the first + + + align:start position:0% +unmaned or manned on the first +flight and we looked at flying unmanned + + align:start position:0% +flight and we looked at flying unmanned + + + align:start position:0% +flight and we looked at flying unmanned +we could have done that we could have + + align:start position:0% +we could have done that we could have + + + align:start position:0% +we could have done that we could have +put an automatic control system in to + + align:start position:0% +put an automatic control system in to + + + align:start position:0% +put an automatic control system in to +take the place of the man and these + + align:start position:0% +take the place of the man and these + + + align:start position:0% +take the place of the man and these +Pilots that tell + + align:start position:0% +Pilots that tell + + + align:start position:0% +Pilots that tell +you they do manual control during + + align:start position:0% +you they do manual control during + + + align:start position:0% +you they do manual control during +re-entry in the + + align:start position:0% +re-entry in the + + + align:start position:0% +re-entry in the +shuttle + + align:start position:0% +shuttle + + + align:start position:0% +shuttle +hogwash pure hogwash the shuttle will + + align:start position:0% +hogwash pure hogwash the shuttle will + + + align:start position:0% +hogwash pure hogwash the shuttle will +not + + align:start position:0% +not + + + align:start position:0% +not +fly without the automatic control system + + align:start position:0% +fly without the automatic control system + + + align:start position:0% +fly without the automatic control system +the pilots are flying the Outer + + align:start position:0% +the pilots are flying the Outer + + + align:start position:0% +the pilots are flying the Outer +Loop I can fly it I have flown it in the + + align:start position:0% +Loop I can fly it I have flown it in the + + + align:start position:0% +Loop I can fly it I have flown it in the +simulator you know how I do it I don't + + align:start position:0% +simulator you know how I do it I don't + + + align:start position:0% +simulator you know how I do it I don't +touch the damn thing + + align:start position:0% + + + + align:start position:0% + +I set you know you set the damn end of + + align:start position:0% +I set you know you set the damn end of + + + align:start position:0% +I set you know you set the damn end of +the runway into the + + align:start position:0% +the runway into the + + + align:start position:0% +the runway into the +computer right down and that's the way + + align:start position:0% +computer right down and that's the way + + + align:start position:0% +computer right down and that's the way +95% of the airliners land today is on + + align:start position:0% +95% of the airliners land today is on + + + align:start position:0% +95% of the airliners land today is on +automatic control and frankly that's how + + align:start position:0% +automatic control and frankly that's how + + + align:start position:0% +automatic control and frankly that's how +the astronauts ought to do it haven't + + align:start position:0% +the astronauts ought to do it haven't + + + align:start position:0% +the astronauts ought to do it haven't +done it yet they keep telling me what + + align:start position:0% +done it yet they keep telling me what + + + align:start position:0% +done it yet they keep telling me what +are we going to do if the system fails + + align:start position:0% +are we going to do if the system fails + + + align:start position:0% +are we going to do if the system fails +and I say to you're going to wind your + + align:start position:0% +and I say to you're going to wind your + + + align:start position:0% +and I say to you're going to wind your +damn clock because that system fails the + + align:start position:0% +damn clock because that system fails the + + + align:start position:0% +damn clock because that system fails the +thing is gone it's an unstable + + align:start position:0% +thing is gone it's an unstable + + + align:start position:0% +thing is gone it's an unstable +machine from Mach + + align:start position:0% +machine from Mach + + + align:start position:0% +machine from Mach +25 to touchdown it's an unstable + + align:start position:0% +25 to touchdown it's an unstable + + + align:start position:0% +25 to touchdown it's an unstable +machine if it diverges it's + + align:start position:0% +machine if it diverges it's + + + align:start position:0% +machine if it diverges it's +gone so probably tell you they doing + + align:start position:0% +gone so probably tell you they doing + + + align:start position:0% +gone so probably tell you they doing +manual entry on the space shuttle I + + align:start position:0% +manual entry on the space shuttle I + + + align:start position:0% +manual entry on the space shuttle I +repeat that statement + + align:start position:0% + + + + align:start position:0% + +hogwash can be + + align:start position:0% +hogwash can be + + + align:start position:0% +hogwash can be +done now can teach them however by + + align:start position:0% +done now can teach them however by + + + align:start position:0% +done now can teach them however by +building a Gulf Stream two + + align:start position:0% +building a Gulf Stream two + + + align:start position:0% +building a Gulf Stream two +into a space shuttle like vehicle I can + + align:start position:0% +into a space shuttle like vehicle I can + + + align:start position:0% +into a space shuttle like vehicle I can +put the control system that they've got + + align:start position:0% +put the control system that they've got + + + align:start position:0% +put the control system that they've got +in there I can repeat that I can make it + + align:start position:0% +in there I can repeat that I can make it + + + align:start position:0% +in there I can repeat that I can make it +come down I can put reverse thrust you + + align:start position:0% +come down I can put reverse thrust you + + + align:start position:0% +come down I can put reverse thrust you +believe on both engines and a G2 and + + align:start position:0% +believe on both engines and a G2 and + + + align:start position:0% +believe on both engines and a G2 and +you're descending and you got both those + + align:start position:0% +you're descending and you got both those + + + align:start position:0% +you're descending and you got both those +damn engines back there going like that + + align:start position:0% +damn engines back there going like that + + + align:start position:0% +damn engines back there going like that +as it does its reverse thrust to match + + align:start position:0% +as it does its reverse thrust to match + + + align:start position:0% +as it does its reverse thrust to match +the drag of the shuttle entry but I can + + align:start position:0% +the drag of the shuttle entry but I can + + + align:start position:0% +the drag of the shuttle entry but I can +teach them pretty well how to do Dead + + align:start position:0% +teach them pretty well how to do Dead + + + align:start position:0% +teach them pretty well how to do Dead +stick Landings and so I put all that + + align:start position:0% +stick Landings and so I put all that + + + align:start position:0% +stick Landings and so I put all that +together and Mr Cohen and Professor + + align:start position:0% +together and Mr Cohen and Professor + + + align:start position:0% +together and Mr Cohen and Professor +Cohen and uh myself and a few others go + + align:start position:0% +Cohen and uh myself and a few others go + + + align:start position:0% +Cohen and uh myself and a few others go +to Washington to convinc the powers that + + align:start position:0% +to Washington to convinc the powers that + + + align:start position:0% +to Washington to convinc the powers that +be that we can fly this machine man on + + align:start position:0% +be that we can fly this machine man on + + + align:start position:0% +be that we can fly this machine man on +the first flight because it is the most + + align:start position:0% +the first flight because it is the most + + + align:start position:0% +the first flight because it is the most +reliable way to fly machine and we + + align:start position:0% +reliable way to fly machine and we + + + align:start position:0% +reliable way to fly machine and we +convinced them it took a little + + align:start position:0% +convinced them it took a little + + + align:start position:0% +convinced them it took a little +doing a lot fancy talking I guess but + + align:start position:0% +doing a lot fancy talking I guess but + + + align:start position:0% +doing a lot fancy talking I guess but +that's what we decided to do and I think + + align:start position:0% +that's what we decided to do and I think + + + align:start position:0% +that's what we decided to do and I think +it was a good decision in + + align:start position:0% +it was a good decision in + + + align:start position:0% +it was a good decision in +retrospect it was a lousy + + align:start position:0% + + + + align:start position:0% + +decision + + align:start position:0% +decision + + + align:start position:0% +decision +why + + align:start position:0% +why + + + align:start position:0% +why +because if we had had unmanned flying + + align:start position:0% +because if we had had unmanned flying + + + align:start position:0% +because if we had had unmanned flying +capability on the orbit and we had to + + align:start position:0% +capability on the orbit and we had to + + + align:start position:0% +capability on the orbit and we had to +challenge your + + align:start position:0% +challenge your + + + align:start position:0% +challenge your +accident we could have flown it again + + align:start position:0% +accident we could have flown it again + + + align:start position:0% +accident we could have flown it again +the next + + align:start position:0% + + + + align:start position:0% + +day with an unmaned control + + align:start position:0% +day with an unmaned control + + + align:start position:0% +day with an unmaned control +system and + + align:start position:0% +system and + + + align:start position:0% +system and +proved that it was + + align:start position:0% + + + + align:start position:0% + +okay but we didn't have that + + align:start position:0% +okay but we didn't have that + + + align:start position:0% +okay but we didn't have that +capability and when you get into the + + align:start position:0% +capability and when you get into the + + + align:start position:0% +capability and when you get into the +politics of flying men in space in this + + align:start position:0% +politics of flying men in space in this + + + align:start position:0% +politics of flying men in space in this +country rational thinking does not carry + + align:start position:0% +country rational thinking does not carry + + + align:start position:0% +country rational thinking does not carry +the day political thinking carries the + + align:start position:0% +the day political thinking carries the + + + align:start position:0% +the day political thinking carries the +day even in nass you'll find that out as + + align:start position:0% +day even in nass you'll find that out as + + + align:start position:0% +day even in nass you'll find that out as +young Engineers also + + align:start position:0% +young Engineers also + + + align:start position:0% +young Engineers also +that you not only have to be an engineer + + align:start position:0% +that you not only have to be an engineer + + + align:start position:0% +that you not only have to be an engineer +you do have to be somewhat of a + + align:start position:0% +you do have to be somewhat of a + + + align:start position:0% +you do have to be somewhat of a +politician in order to sell your + + align:start position:0% +politician in order to sell your + + + align:start position:0% +politician in order to sell your +programs + + align:start position:0% +programs + + + align:start position:0% +programs +so we convinced + + align:start position:0% +so we convinced + + + align:start position:0% +so we convinced +ourselves + + align:start position:0% +ourselves + + + align:start position:0% +ourselves +that it was the best thing to do at that + + align:start position:0% +that it was the best thing to do at that + + + align:start position:0% +that it was the best thing to do at that +time to fly man on the first flight + + align:start position:0% +time to fly man on the first flight + + + align:start position:0% +time to fly man on the first flight +uh because it's in my head and it comes + + align:start position:0% +uh because it's in my head and it comes + + + align:start position:0% +uh because it's in my head and it comes +out I I want to say a little bit about + + align:start position:0% +out I I want to say a little bit about + + + align:start position:0% +out I I want to say a little bit about +the problems that they face + + align:start position:0% +the problems that they face + + + align:start position:0% +the problems that they face +today or the way in which they use the + + align:start position:0% +today or the way in which they use the + + + align:start position:0% +today or the way in which they use the +space + + align:start position:0% +space + + + align:start position:0% +space +shuttle today is + + align:start position:0% +shuttle today is + + + align:start position:0% +shuttle today is +frankly not how we intended the machine + + align:start position:0% +frankly not how we intended the machine + + + align:start position:0% +frankly not how we intended the machine +to + + align:start position:0% +to + + + align:start position:0% +to +fly we have quad + + align:start position:0% +fly we have quad + + + align:start position:0% +fly we have quad +redundancy and the way Nasa uses it + + align:start position:0% +redundancy and the way Nasa uses it + + + align:start position:0% +redundancy and the way Nasa uses it +makes it less + + align:start position:0% + + + + align:start position:0% + +reliable than if we had just had a damn + + align:start position:0% +reliable than if we had just had a damn + + + align:start position:0% +reliable than if we had just had a damn +single string system + + align:start position:0% + + + + align:start position:0% + +why because they have to have all quad + + align:start position:0% +why because they have to have all quad + + + align:start position:0% +why because they have to have all quad +redundant systems working at + + align:start position:0% + + + + align:start position:0% + +liftoff so all four systems have to be + + align:start position:0% +liftoff so all four systems have to be + + + align:start position:0% +liftoff so all four systems have to be +operating at lift off that's + + align:start position:0% +operating at lift off that's + + + align:start position:0% +operating at lift off that's +hard it's hard enough to have one + + align:start position:0% +hard it's hard enough to have one + + + align:start position:0% +hard it's hard enough to have one +operating properly now you have to have + + align:start position:0% +operating properly now you have to have + + + align:start position:0% +operating properly now you have to have +all four in all of the places where you + + align:start position:0% +all four in all of the places where you + + + align:start position:0% +all four in all of the places where you +have quad + + align:start position:0% +have quad + + + align:start position:0% +have quad +redundancy that isn't how we intended it + + align:start position:0% +redundancy that isn't how we intended it + + + align:start position:0% +redundancy that isn't how we intended it +to to work what we intended to do was + + align:start position:0% +to to work what we intended to do was + + + align:start position:0% +to to work what we intended to do was +you to the pad and get ready to launch + + align:start position:0% +you to the pad and get ready to launch + + + align:start position:0% +you to the pad and get ready to launch +and one system fails you keep right on + + align:start position:0% +and one system fails you keep right on + + + align:start position:0% +and one system fails you keep right on +going if you have two fail you keep + + align:start position:0% +going if you have two fail you keep + + + align:start position:0% +going if you have two fail you keep +right on + + align:start position:0% +right on + + + align:start position:0% +right on +going that's the way we intended it to + + align:start position:0% +going that's the way we intended it to + + + align:start position:0% +going that's the way we intended it to +be because we wanted it to be a reusable + + align:start position:0% +be because we wanted it to be a reusable + + + align:start position:0% +be because we wanted it to be a reusable +system with quick + + align:start position:0% +system with quick + + + align:start position:0% +system with quick +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +turnaround two weeks we want to be able + + align:start position:0% +turnaround two weeks we want to be able + + + align:start position:0% +turnaround two weeks we want to be able +to turn that machine + + align:start position:0% +to turn that machine + + + align:start position:0% +to turn that machine +around and you could do that + + align:start position:0% +around and you could do that + + + align:start position:0% +around and you could do that +today because God they've flown at 10 + + align:start position:0% +today because God they've flown at 10 + + + align:start position:0% +today because God they've flown at 10 +some time they know that machine they + + align:start position:0% +some time they know that machine they + + + align:start position:0% +some time they know that machine they +know it well they know how the systems + + align:start position:0% +know it well they know how the systems + + + align:start position:0% +know it well they know how the systems +perform you can look at the Telemetry + + align:start position:0% +perform you can look at the Telemetry + + + align:start position:0% +perform you can look at the Telemetry +when it lands and say all three of the + + align:start position:0% +when it lands and say all three of the + + + align:start position:0% +when it lands and say all three of the +three of the four were working and I got + + align:start position:0% +three of the four were working and I got + + + align:start position:0% +three of the four were working and I got +a thing over here I can fix that in 10 + + align:start position:0% +a thing over here I can fix that in 10 + + + align:start position:0% +a thing over here I can fix that in 10 +minutes I'm ready to go they put more + + align:start position:0% +minutes I'm ready to go they put more + + + align:start position:0% +minutes I'm ready to go they put more +time on the systems on the ground than + + align:start position:0% +time on the systems on the ground than + + + align:start position:0% +time on the systems on the ground than +they do in + + align:start position:0% +they do in + + + align:start position:0% +they do in +Flight testing the + + align:start position:0% + + + + align:start position:0% + +machine is that + + align:start position:0% +machine is that + + + align:start position:0% +machine is that +expensive my God that's the reason it + + align:start position:0% +expensive my God that's the reason it + + + align:start position:0% +expensive my God that's the reason it +costs $4 billion dollar a year to keep + + align:start position:0% +costs $4 billion dollar a year to keep + + + align:start position:0% +costs $4 billion dollar a year to keep +all those running standing army at + + align:start position:0% + + + + align:start position:0% + +capear if you're going to build + + align:start position:0% +capear if you're going to build + + + align:start position:0% +capear if you're going to build +redundancy in in the future you guys + + align:start position:0% +redundancy in in the future you guys + + + align:start position:0% +redundancy in in the future you guys +you're going to put redundancy in this + + align:start position:0% +you're going to put redundancy in this + + + align:start position:0% +you're going to put redundancy in this +machine don't tell them about + + align:start position:0% + + + + align:start position:0% + +it now that may sound funny but that's + + align:start position:0% +it now that may sound funny but that's + + + align:start position:0% +it now that may sound funny but that's +how your computer is designed + + align:start position:0% +how your computer is designed + + + align:start position:0% +how your computer is designed +you don't have bike in your computer + + align:start position:0% +you don't have bike in your computer + + + align:start position:0% +you don't have bike in your computer +anymore built in test equipment you know + + align:start position:0% +anymore built in test equipment you know + + + align:start position:0% +anymore built in test equipment you know +why because the damn Engineers kept + + align:start position:0% +why because the damn Engineers kept + + + align:start position:0% +why because the damn Engineers kept +using it so now the computer pillers + + align:start position:0% +using it so now the computer pillers + + + align:start position:0% +using it so now the computer pillers +build in the test equipment but they + + align:start position:0% +build in the test equipment but they + + + align:start position:0% +build in the test equipment but they +don't tell you it's there the redundancy + + align:start position:0% +don't tell you it's there the redundancy + + + align:start position:0% +don't tell you it's there the redundancy +Works + + align:start position:0% +Works + + + align:start position:0% +Works +automatically probably got three or four + + align:start position:0% +automatically probably got three or four + + + align:start position:0% +automatically probably got three or four +in there just like we do in the shuttle + + align:start position:0% +in there just like we do in the shuttle + + + align:start position:0% +in there just like we do in the shuttle +but your computer keeps work it might be + + align:start position:0% +but your computer keeps work it might be + + + align:start position:0% +but your computer keeps work it might be +a little + + align:start position:0% +a little + + + align:start position:0% +a little +slower sometimes it get you mad as hell + + align:start position:0% +slower sometimes it get you mad as hell + + + align:start position:0% +slower sometimes it get you mad as hell +but they don't tell you about it so my + + align:start position:0% +but they don't tell you about it so my + + + align:start position:0% +but they don't tell you about it so my +advice is don't tell the people about it + + align:start position:0% +advice is don't tell the people about it + + + align:start position:0% +advice is don't tell the people about it +the next time don't tell the people the + + align:start position:0% +the next time don't tell the people the + + + align:start position:0% +the next time don't tell the people the +cape this's got quadr dcy and that + + align:start position:0% +cape this's got quadr dcy and that + + + align:start position:0% +cape this's got quadr dcy and that +sounds that's probably somewhat + + align:start position:0% +sounds that's probably somewhat + + + align:start position:0% +sounds that's probably somewhat +foolishness but I guarantee that if I + + align:start position:0% +foolishness but I guarantee that if I + + + align:start position:0% +foolishness but I guarantee that if I +had anything to do about it and the next + + align:start position:0% +had anything to do about it and the next + + + align:start position:0% +had anything to do about it and the next +time I might very well do it that + + align:start position:0% +time I might very well do it that + + + align:start position:0% +time I might very well do it that +way because it's not the right way to + + align:start position:0% +way because it's not the right way to + + + align:start position:0% +way because it's not the right way to +think about this machine the machine is + + align:start position:0% +think about this machine the machine is + + + align:start position:0% +think about this machine the machine is +a beautiful + + align:start position:0% +a beautiful + + + align:start position:0% +a beautiful +wonderful piece of hardware + + align:start position:0% + + + + align:start position:0% + +the + + align:start position:0% +the + + + align:start position:0% +the +Orbiter system the most complex system + + align:start position:0% +Orbiter system the most complex system + + + align:start position:0% +Orbiter system the most complex system +ever built by man to fly has + + align:start position:0% +ever built by man to fly has + + + align:start position:0% +ever built by man to fly has +never I was talking to some co-ops a few + + align:start position:0% +never I was talking to some co-ops a few + + + align:start position:0% +never I was talking to some co-ops a few +days ago I said that word 14 times it's + + align:start position:0% +days ago I said that word 14 times it's + + + align:start position:0% +days ago I said that word 14 times it's +never had a + + align:start position:0% + + + + align:start position:0% + +failure the Orbiter has never had a + + align:start position:0% +failure the Orbiter has never had a + + + align:start position:0% +failure the Orbiter has never had a +failure that would have prevented that + + align:start position:0% +failure that would have prevented that + + + align:start position:0% +failure that would have prevented that +machine from Landing + + align:start position:0% + + + + align:start position:0% + +safely n is now going to use however all + + align:start position:0% +safely n is now going to use however all + + + align:start position:0% +safely n is now going to use however all +the components that have + + align:start position:0% + + + + align:start position:0% + +failed they're going to use the solid + + align:start position:0% +failed they're going to use the solid + + + align:start position:0% +failed they're going to use the solid +rocket you're going to put a command + + align:start position:0% +rocket you're going to put a command + + + align:start position:0% +rocket you're going to put a command +like service module on top of it with an + + align:start position:0% +like service module on top of it with an + + + align:start position:0% +like service module on top of it with an +escape + + align:start position:0% +escape + + + align:start position:0% +escape +rocket and fly it that system has + + align:start position:0% +rocket and fly it that system has + + + align:start position:0% +rocket and fly it that system has +failed they're going to use the + + align:start position:0% +failed they're going to use the + + + align:start position:0% +failed they're going to use the +tank can't figure out Engineers this day + + align:start position:0% +tank can't figure out Engineers this day + + + align:start position:0% +tank can't figure out Engineers this day +in time can't figure out to put how to + + align:start position:0% +in time can't figure out to put how to + + + align:start position:0% +in time can't figure out to put how to +put insulation on a tank + + align:start position:0% +put insulation on a tank + + + align:start position:0% +put insulation on a tank +ridiculous not only ridiculous + + align:start position:0% +ridiculous not only ridiculous + + + align:start position:0% +ridiculous not only ridiculous +ludicrous you mean to tell me at the AR + + align:start position:0% +ludicrous you mean to tell me at the AR + + + align:start position:0% +ludicrous you mean to tell me at the AR +a design engineer sitting in this room + + align:start position:0% +a design engineer sitting in this room + + + align:start position:0% +a design engineer sitting in this room +that can't tell you how to keep the foam + + align:start position:0% +that can't tell you how to keep the foam + + + align:start position:0% +that can't tell you how to keep the foam +insulation on that tank hell my son + + align:start position:0% +insulation on that tank hell my son + + + align:start position:0% +insulation on that tank hell my son +could do it in fact my grandson could + + align:start position:0% +could do it in fact my grandson could + + + align:start position:0% +could do it in fact my grandson could +probably do it + + align:start position:0% + + + + align:start position:0% + +the engines the space shuttle main + + align:start position:0% +the engines the space shuttle main + + + align:start position:0% +the engines the space shuttle main +engines that is a damn tough piece of + + align:start position:0% +engines that is a damn tough piece of + + + align:start position:0% +engines that is a damn tough piece of +Hardware that's what we're going to use + + align:start position:0% +Hardware that's what we're going to use + + + align:start position:0% +Hardware that's what we're going to use +that's what we're going to put in orbit + + align:start position:0% +that's what we're going to put in orbit + + + align:start position:0% +that's what we're going to put in orbit +and use it as a MCH as a as a propulsion + + align:start position:0% +and use it as a MCH as a as a propulsion + + + align:start position:0% +and use it as a MCH as a as a propulsion +system to send you to the moon now they + + align:start position:0% +system to send you to the moon now they + + + align:start position:0% +system to send you to the moon now they +say oh we're going to make some changes + + align:start position:0% +say oh we're going to make some changes + + + align:start position:0% +say oh we're going to make some changes +to it make it + + align:start position:0% +to it make it + + + align:start position:0% +to it make it +better + + align:start position:0% +better + + + align:start position:0% +better +H I'll probably be dead gone but I'd + + align:start position:0% +H I'll probably be dead gone but I'd + + + align:start position:0% +H I'll probably be dead gone but I'd +like to see it + + align:start position:0% +like to see it + + + align:start position:0% +like to see it +that thing is designed right up to the + + align:start position:0% +that thing is designed right up to the + + + align:start position:0% +that thing is designed right up to the +teeth maximum power you can get out of + + align:start position:0% +teeth maximum power you can get out of + + + align:start position:0% +teeth maximum power you can get out of +hydrogen and oxygen has an ISP of above + + align:start position:0% +hydrogen and oxygen has an ISP of above + + + align:start position:0% +hydrogen and oxygen has an ISP of above +460 and the engine on the shuttle is + + align:start position:0% +460 and the engine on the shuttle is + + + align:start position:0% +460 and the engine on the shuttle is +458 I don't know how you can get much + + align:start position:0% +458 I don't know how you can get much + + + align:start position:0% +458 I don't know how you can get much +more efficient than that but that really + + align:start position:0% +more efficient than that but that really + + + align:start position:0% +more efficient than that but that really +is a tough + + align:start position:0% + + + + align:start position:0% + +engine continuously changing components + + align:start position:0% +engine continuously changing components + + + align:start position:0% +engine continuously changing components +but those are the three components NES + + align:start position:0% +but those are the three components NES + + + align:start position:0% +but those are the three components NES +when use those to go or the moon but I + + align:start position:0% +when use those to go or the moon but I + + + align:start position:0% +when use those to go or the moon but I +would throw the Orbiter + + align:start position:0% +would throw the Orbiter + + + align:start position:0% +would throw the Orbiter +away never had a failure on the + + align:start position:0% + + + + align:start position:0% + +Orbiter + + align:start position:0% +Orbiter + + + align:start position:0% +Orbiter +uh talk a little bit about rtls we + + align:start position:0% +uh talk a little bit about rtls we + + + align:start position:0% +uh talk a little bit about rtls we +turned the laite that sounds like + + align:start position:0% +turned the laite that sounds like + + + align:start position:0% +turned the laite that sounds like +something easy to do but think about the + + align:start position:0% +something easy to do but think about the + + + align:start position:0% +something easy to do but think about the +software involved in that little dude + + align:start position:0% +software involved in that little dude + + + align:start position:0% +software involved in that little dude +and figuring out how to do + + align:start position:0% +and figuring out how to do + + + align:start position:0% +and figuring out how to do +it how to re how to take that machine + + align:start position:0% +it how to re how to take that machine + + + align:start position:0% +it how to re how to take that machine +back to land at Cape canaval if you do + + align:start position:0% +back to land at Cape canaval if you do + + + align:start position:0% +back to land at Cape canaval if you do +have an abort think about the software + + align:start position:0% +have an abort think about the software + + + align:start position:0% +have an abort think about the software +involved in that think about the + + align:start position:0% +involved in that think about the + + + align:start position:0% +involved in that think about the +possibilities think about the cut off + + align:start position:0% +possibilities think about the cut off + + + align:start position:0% +possibilities think about the cut off +conditions think about the mck number + + align:start position:0% +conditions think about the mck number + + + align:start position:0% +conditions think about the mck number +range you're going to have to + + align:start position:0% + + + + align:start position:0% + +fly + + align:start position:0% +fly + + + align:start position:0% +fly +so return to launch site was part of our + + align:start position:0% +so return to launch site was part of our + + + align:start position:0% +so return to launch site was part of our +philosophy of not having an escape + + align:start position:0% +philosophy of not having an escape + + + align:start position:0% +philosophy of not having an escape +system per + + align:start position:0% +system per + + + align:start position:0% +system per +se on the + + align:start position:0% +se on the + + + align:start position:0% +se on the +shuttle I'd like to also + + align:start position:0% +shuttle I'd like to also + + + align:start position:0% +shuttle I'd like to also +I know we have some navigation guidance + + align:start position:0% +I know we have some navigation guidance + + + align:start position:0% +I know we have some navigation guidance +people in this + + align:start position:0% +people in this + + + align:start position:0% +people in this +audience how then did we decide Jeff + + align:start position:0% +audience how then did we decide Jeff + + + align:start position:0% +audience how then did we decide Jeff +asked me to fly the first + + align:start position:0% + + + + align:start position:0% + +time that was tough very difficult we + + align:start position:0% +time that was tough very difficult we + + + align:start position:0% +time that was tough very difficult we +had some of the best experts in the + + align:start position:0% +had some of the best experts in the + + + align:start position:0% +had some of the best experts in the +world come review what we were doing + + align:start position:0% +world come review what we were doing + + + align:start position:0% +world come review what we were doing +look at all the systems the one thing + + align:start position:0% +look at all the systems the one thing + + + align:start position:0% +look at all the systems the one thing +that two things really that they had the + + align:start position:0% +that two things really that they had the + + + align:start position:0% +that two things really that they had the +most trouble with + + align:start position:0% +most trouble with + + + align:start position:0% +most trouble with +in in making sure we knew what we were + + align:start position:0% +in in making sure we knew what we were + + + align:start position:0% +in in making sure we knew what we were +doing first with the thermal protection + + align:start position:0% +doing first with the thermal protection + + + align:start position:0% +doing first with the thermal protection +system and we never really convinced the + + align:start position:0% +system and we never really convinced the + + + align:start position:0% +system and we never really convinced the +experts that we did have a thermal + + align:start position:0% +experts that we did have a thermal + + + align:start position:0% +experts that we did have a thermal +protection system that work that would + + align:start position:0% +protection system that work that would + + + align:start position:0% +protection system that work that would +work as a matter of fact the man who + + align:start position:0% +work as a matter of fact the man who + + + align:start position:0% +work as a matter of fact the man who +invented lunar orbit rodo at least sold + + align:start position:0% +invented lunar orbit rodo at least sold + + + align:start position:0% +invented lunar orbit rodo at least sold +the day he didn't invent it but he sold + + align:start position:0% +the day he didn't invent it but he sold + + + align:start position:0% +the day he didn't invent it but he sold +the day in using lunar Robert Rond + + align:start position:0% +the day in using lunar Robert Rond + + + align:start position:0% +the day in using lunar Robert Rond +and the + + align:start position:0% +and the + + + align:start position:0% +and the +chief structures engineer in the United + + align:start position:0% +chief structures engineer in the United + + + align:start position:0% +chief structures engineer in the United +States that's probably a stretch but one + + align:start position:0% +States that's probably a stretch but one + + + align:start position:0% +States that's probably a stretch but one +of them at + + align:start position:0% +of them at + + + align:start position:0% +of them at +Stanford wrote me a cosign + + align:start position:0% +Stanford wrote me a cosign + + + align:start position:0% +Stanford wrote me a cosign +letter on T minus one month after we had + + align:start position:0% +letter on T minus one month after we had + + + align:start position:0% +letter on T minus one month after we had +reviewed this system we had done + + align:start position:0% +reviewed this system we had done + + + align:start position:0% +reviewed this system we had done +everything they asked us to do we ran + + align:start position:0% +everything they asked us to do we ran + + + align:start position:0% +everything they asked us to do we ran +combined loads tests we were ran worse + + align:start position:0% +combined loads tests we were ran worse + + + align:start position:0% +combined loads tests we were ran worse +loads tests we ran combined worse loads + + align:start position:0% +loads tests we ran combined worse loads + + + align:start position:0% +loads tests we ran combined worse loads +tests to prove to ourselves that the + + align:start position:0% +tests to prove to ourselves that the + + + align:start position:0% +tests to prove to ourselves that the +thermal protection system wouldn't fail + + align:start position:0% +thermal protection system wouldn't fail + + + align:start position:0% +thermal protection system wouldn't fail +I got this letter at T minus one + + align:start position:0% +I got this letter at T minus one + + + align:start position:0% +I got this letter at T minus one +month now in my effects at Virginia Tech + + align:start position:0% +month now in my effects at Virginia Tech + + + align:start position:0% +month now in my effects at Virginia Tech +as a matter of fact Virginia Tech said + + align:start position:0% +as a matter of fact Virginia Tech said + + + align:start position:0% +as a matter of fact Virginia Tech said +are you sure you want this + + align:start position:0% +are you sure you want this + + + align:start position:0% +are you sure you want this +letter in your in your files I said oh + + align:start position:0% +letter in your in your files I said oh + + + align:start position:0% +letter in your in your files I said oh +yes I want that letter in my fil it's + + align:start position:0% +yes I want that letter in my fil it's + + + align:start position:0% +yes I want that letter in my fil it's +probably the most important letter + + align:start position:0% +probably the most important letter + + + align:start position:0% +probably the most important letter +you'll ever have in my files but these + + align:start position:0% +you'll ever have in my files but these + + + align:start position:0% +you'll ever have in my files but these +two gentlemen said we implore + + align:start position:0% +two gentlemen said we implore + + + align:start position:0% +two gentlemen said we implore +you not to fly the SP + + align:start position:0% +you not to fly the SP + + + align:start position:0% +you not to fly the SP +shut Orbiter about fly the or + + align:start position:0% +shut Orbiter about fly the or + + + align:start position:0% +shut Orbiter about fly the or +because the tiles are going to come off + + align:start position:0% +because the tiles are going to come off + + + align:start position:0% +because the tiles are going to come off +it may not come off while you're at the + + align:start position:0% +it may not come off while you're at the + + + align:start position:0% +it may not come off while you're at the +max heating pulse but by the time you + + align:start position:0% +max heating pulse but by the time you + + + align:start position:0% +max heating pulse but by the time you +get ready to land NASA is going to be + + align:start position:0% +get ready to land NASA is going to be + + + align:start position:0% +get ready to land NASA is going to be +totally embarrassed because all the + + align:start position:0% +totally embarrassed because all the + + + align:start position:0% +totally embarrassed because all the +tiles are going to fall + + align:start position:0% +tiles are going to fall + + + align:start position:0% +tiles are going to fall +off and we would ask you to put a steel + + align:start position:0% +off and we would ask you to put a steel + + + align:start position:0% +off and we would ask you to put a steel +net around this vehicle so that they + + align:start position:0% +net around this vehicle so that they + + + align:start position:0% +net around this vehicle so that they +won't fall off + + align:start position:0% + + + + align:start position:0% + +I'm I'm still a + + align:start position:0% +I'm I'm still a + + + align:start position:0% +I'm I'm still a +gas at that letter because I don't know + + align:start position:0% +gas at that letter because I don't know + + + align:start position:0% +gas at that letter because I don't know +what we else we could have done to + + align:start position:0% +what we else we could have done to + + + align:start position:0% +what we else we could have done to +satisfy them that we had done everything + + align:start position:0% +satisfy them that we had done everything + + + align:start position:0% +satisfy them that we had done everything +they asked us we they were concerned + + align:start position:0% +they asked us we they were concerned + + + align:start position:0% +they asked us we they were concerned +that the that the strain isolation pad + + align:start position:0% +that the that the strain isolation pad + + + align:start position:0% +that the that the strain isolation pad +which is what the tile sits on and you + + align:start position:0% +which is what the tile sits on and you + + + align:start position:0% +which is what the tile sits on and you +you've had that explanation they were + + align:start position:0% +you've had that explanation they were + + + align:start position:0% +you've had that explanation they were +they were concerned that combined + + align:start position:0% +they were concerned that combined + + + align:start position:0% +they were concerned that combined +vibrations and aerodynamic loads would + + align:start position:0% +vibrations and aerodynamic loads would + + + align:start position:0% +vibrations and aerodynamic loads would +cause a failure in this sip or at least + + align:start position:0% +cause a failure in this sip or at least + + + align:start position:0% +cause a failure in this sip or at least +at the glue J and and that indeed all + + align:start position:0% +at the glue J and and that indeed all + + + align:start position:0% +at the glue J and and that indeed all +the major tiles that had gone through + + align:start position:0% +the major tiles that had gone through + + + align:start position:0% +the major tiles that had gone through +the large heat PS would fall off Mr Cen + + align:start position:0% +the large heat PS would fall off Mr Cen + + + align:start position:0% +the large heat PS would fall off Mr Cen +Professor Co I'll keep calling you Mr + + align:start position:0% +Professor Co I'll keep calling you Mr + + + align:start position:0% +Professor Co I'll keep calling you Mr +Cohen Professor + + align:start position:0% +Cohen Professor + + + align:start position:0% +Cohen Professor +Cohen and I met them on the queen + + align:start position:0% +Cohen and I met them on the queen + + + align:start position:0% +Cohen and I met them on the queen +maray at an AI meeting that that + + align:start position:0% +maray at an AI meeting that that + + + align:start position:0% +maray at an AI meeting that that +uh after the first + + align:start position:0% +uh after the first + + + align:start position:0% +uh after the first +flight had taken place was satisfactory + + align:start position:0% +flight had taken place was satisfactory + + + align:start position:0% +flight had taken place was satisfactory +well FW + + align:start position:0% +well FW + + + align:start position:0% +well FW +beautifully they came those two + + align:start position:0% +beautifully they came those two + + + align:start position:0% +beautifully they came those two +gentlemen came running out and I asked + + align:start position:0% +gentlemen came running out and I asked + + + align:start position:0% +gentlemen came running out and I asked +Aaron if we would come and sit down and + + align:start position:0% +Aaron if we would come and sit down and + + + align:start position:0% +Aaron if we would come and sit down and +have a drink with + + align:start position:0% + + + + align:start position:0% + +them and we said hell no and walked away + + align:start position:0% +them and we said hell no and walked away + + + align:start position:0% +them and we said hell no and walked away +from + + align:start position:0% + + + + align:start position:0% + +them so that's what I thought of that + + align:start position:0% +them so that's what I thought of that + + + align:start position:0% +them so that's what I thought of that +letter + + align:start position:0% + + + + align:start position:0% + +uh now the the other thing I want to + + align:start position:0% +uh now the the other thing I want to + + + align:start position:0% +uh now the the other thing I want to +talk about is the control system of the + + align:start position:0% +talk about is the control system of the + + + align:start position:0% +talk about is the control system of the +shuttle we had several + + align:start position:0% + + + + align:start position:0% + +gentlemen + + align:start position:0% +gentlemen + + + align:start position:0% +gentlemen +did the public affairs officer said we + + align:start position:0% +did the public affairs officer said we + + + align:start position:0% +did the public affairs officer said we +have we need a comment from you after + + align:start position:0% +have we need a comment from you after + + + align:start position:0% +have we need a comment from you after +the after the machine had landed on what + + align:start position:0% +the after the machine had landed on what + + + align:start position:0% +the after the machine had landed on what +what you think of this flight and I said + + align:start position:0% +what you think of this flight and I said + + + align:start position:0% +what you think of this flight and I said +I said we have just become infinitely + + align:start position:0% +I said we have just become infinitely + + + align:start position:0% +I said we have just become infinitely +smarter + + align:start position:0% +smarter + + + align:start position:0% +smarter +uh not so much about the tile where we + + align:start position:0% +uh not so much about the tile where we + + + align:start position:0% +uh not so much about the tile where we +in the story I'm about to tell the + + align:start position:0% +in the story I'm about to tell the + + + align:start position:0% +in the story I'm about to tell the +automatic control + + align:start position:0% +automatic control + + + align:start position:0% +automatic control +system there there in terms of the the + + align:start position:0% +system there there in terms of the the + + + align:start position:0% +system there there in terms of the the +the aerodynamic parameters that it has + + align:start position:0% +the aerodynamic parameters that it has + + + align:start position:0% +the aerodynamic parameters that it has +to deal + + align:start position:0% +to deal + + + align:start position:0% +to deal +with there are there are roughly + + align:start position:0% +with there are there are roughly + + + align:start position:0% +with there are there are roughly + + align:start position:0% + + + align:start position:0% +variables in the aerodynamics of the + + align:start position:0% +variables in the aerodynamics of the + + + align:start position:0% +variables in the aerodynamics of the +machine all the way from products of + + align:start position:0% +machine all the way from products of + + + align:start position:0% +machine all the way from products of +inertia to CN + + align:start position:0% +inertia to CN + + + align:start position:0% +inertia to CN +beta know CN + + align:start position:0% + + + + align:start position:0% + +beta CN beta know the young man knows + + align:start position:0% +beta CN beta know the young man knows + + + align:start position:0% +beta CN beta know the young man knows +what CN beta that's the capability of + + align:start position:0% +what CN beta that's the capability of + + + align:start position:0% +what CN beta that's the capability of +the rudder to stabilize the + + align:start position:0% +the rudder to stabilize the + + + align:start position:0% +the rudder to stabilize the +machine was is it going moment do the + + align:start position:0% +machine was is it going moment do the + + + align:start position:0% +machine was is it going moment do the +side I still still do remember a little + + align:start position:0% +side I still still do remember a little + + + align:start position:0% +side I still still do remember a little +bit of it than that anyway there the + + align:start position:0% + + + + align:start position:0% + +airplane is there is no facili in the + + align:start position:0% +airplane is there is no facili in the + + + align:start position:0% +airplane is there is no facili in the +world to measure the aerodynamic those + + align:start position:0% +world to measure the aerodynamic those + + + align:start position:0% +world to measure the aerodynamic those + + align:start position:0% + + + align:start position:0% +parameters uh uh very accurately + + align:start position:0% +parameters uh uh very accurately + + + align:start position:0% +parameters uh uh very accurately +anyway uh in the in that would tell you + + align:start position:0% +anyway uh in the in that would tell you + + + align:start position:0% +anyway uh in the in that would tell you +what to design the automatic control + + align:start position:0% +what to design the automatic control + + + align:start position:0% +what to design the automatic control +system + + align:start position:0% +system + + + align:start position:0% +system +to uh particularly it's not it's not not + + align:start position:0% +to uh particularly it's not it's not not + + + align:start position:0% +to uh particularly it's not it's not not +so difficult at High mock numbers above + + align:start position:0% +so difficult at High mock numbers above + + + align:start position:0% +so difficult at High mock numbers above +say 10 you can use uh what do you call + + align:start position:0% +say 10 you can use uh what do you call + + + align:start position:0% +say 10 you can use uh what do you call +it Newtonian flow and and uh you as you + + align:start position:0% +it Newtonian flow and and uh you as you + + + align:start position:0% +it Newtonian flow and and uh you as you +well know you use the aerodynamic + + align:start position:0% +well know you use the aerodynamic + + + align:start position:0% +well know you use the aerodynamic +controls when you can you use the + + align:start position:0% +controls when you can you use the + + + align:start position:0% +controls when you can you use the +thrusters when you can and you combine + + align:start position:0% +thrusters when you can and you combine + + + align:start position:0% +thrusters when you can and you combine +the two as you trans + + align:start position:0% +the two as you trans + + + align:start position:0% +the two as you trans +transfer from one to the other in the + + align:start position:0% +transfer from one to the other in the + + + align:start position:0% +transfer from one to the other in the +range of flight or in the flight + + align:start position:0% +range of flight or in the flight + + + align:start position:0% +range of flight or in the flight +reges but + + align:start position:0% +reges but + + + align:start position:0% +reges but +actually it's a guess we looked at all + + align:start position:0% +actually it's a guess we looked at all + + + align:start position:0% +actually it's a guess we looked at all +of the possibilities of that had been + + align:start position:0% +of the possibilities of that had been + + + align:start position:0% +of the possibilities of that had been +done at uh on the X15 had been done on + + align:start position:0% +done at uh on the X15 had been done on + + + align:start position:0% +done at uh on the X15 had been done on +the Dinos program had been done in Wind + + align:start position:0% +the Dinos program had been done in Wind + + + align:start position:0% +the Dinos program had been done in Wind +Tunnel tests of almost every + + align:start position:0% +Tunnel tests of almost every + + + align:start position:0% +Tunnel tests of almost every +configuration for Hypersonic flow and + + align:start position:0% +configuration for Hypersonic flow and + + + align:start position:0% +configuration for Hypersonic flow and +you just could nail down what those 35 + + align:start position:0% +you just could nail down what those 35 + + + align:start position:0% +you just could nail down what those 35 +parameters were so what we did was we + + align:start position:0% +parameters were so what we did was we + + + align:start position:0% +parameters were so what we did was we +said here's what we think it is here's a + + align:start position:0% +said here's what we think it is here's a + + + align:start position:0% +said here's what we think it is here's a +variation on top of + + align:start position:0% +variation on top of + + + align:start position:0% +variation on top of +that and here's a deviation on top of + + align:start position:0% +that and here's a deviation on top of + + + align:start position:0% +that and here's a deviation on top of +that and here's those 35 parameters + + align:start position:0% +that and here's those 35 parameters + + + align:start position:0% +that and here's those 35 parameters +throughout the total marck range and and + + align:start position:0% +throughout the total marck range and and + + + align:start position:0% +throughout the total marck range and and +we're going to do a Monte Carlo + + align:start position:0% +we're going to do a Monte Carlo + + + align:start position:0% +we're going to do a Monte Carlo +analysis at every tenth of a mock + + align:start position:0% +analysis at every tenth of a mock + + + align:start position:0% +analysis at every tenth of a mock +number from + + align:start position:0% +number from + + + align:start position:0% +number from +25 to + + align:start position:0% +25 to + + + align:start position:0% +25 to +touchdown and have no failures and if we + + align:start position:0% +touchdown and have no failures and if we + + + align:start position:0% +touchdown and have no failures and if we +have a failure have to change the gains + + align:start position:0% +have a failure have to change the gains + + + align:start position:0% +have a failure have to change the gains +go back and run it + + align:start position:0% + + + + align:start position:0% + +again I don't know about you that sure + + align:start position:0% +again I don't know about you that sure + + + align:start position:0% +again I don't know about you that sure +convinced me that that machine would + + align:start position:0% +convinced me that that machine would + + + align:start position:0% +convinced me that that machine would +apply + + align:start position:0% +apply + + + align:start position:0% +apply +but I still + + align:start position:0% +but I still + + + align:start position:0% +but I still +said we just became infinitely + + align:start position:0% +said we just became infinitely + + + align:start position:0% +said we just became infinitely +smarter I I said before we + + align:start position:0% +smarter I I said before we + + + align:start position:0% +smarter I I said before we +flew we will certainly have to change + + align:start position:0% +flew we will certainly have to change + + + align:start position:0% +flew we will certainly have to change +the gains because there will be regions + + align:start position:0% +the gains because there will be regions + + + align:start position:0% +the gains because there will be regions +where the machine is is oscillatory + + align:start position:0% +where the machine is is oscillatory + + + align:start position:0% +where the machine is is oscillatory +coming down and might might frighten + + align:start position:0% +coming down and might might frighten + + + align:start position:0% +coming down and might might frighten +somebody even if they even if they were + + align:start position:0% +somebody even if they even if they were + + + align:start position:0% +somebody even if they even if they were +going to + + align:start position:0% +going to + + + align:start position:0% +going to +damp that was post flight I + + align:start position:0% +damp that was post flight I + + + align:start position:0% +damp that was post flight I +said I don't ever want to change the + + align:start position:0% +said I don't ever want to change the + + + align:start position:0% +said I don't ever want to change the +games the damn + + align:start position:0% + + + + align:start position:0% + +worked so those two J those two problems + + align:start position:0% +worked so those two J those two problems + + + align:start position:0% +worked so those two J those two problems +were the fundamentally hardest problems + + align:start position:0% +were the fundamentally hardest problems + + + align:start position:0% +were the fundamentally hardest problems +to build and test and assure yourself + + align:start position:0% +to build and test and assure yourself + + + align:start position:0% +to build and test and assure yourself +that you were ready to fly but in the + + align:start position:0% +that you were ready to fly but in the + + + align:start position:0% +that you were ready to fly but in the +end how did we decide to + + align:start position:0% +end how did we decide to + + + align:start position:0% +end how did we decide to +fly frankly I didn't know what else to + + align:start position:0% + + + + align:start position:0% + +do I in my mind Professor cen's mind + + align:start position:0% +do I in my mind Professor cen's mind + + + align:start position:0% +do I in my mind Professor cen's mind +John mind who was the head of man space + + align:start position:0% +John mind who was the head of man space + + + align:start position:0% +John mind who was the head of man space +PL these gentleman sitting in front of + + align:start position:0% +PL these gentleman sitting in front of + + + align:start position:0% +PL these gentleman sitting in front of +me that worked on the automatic control + + align:start position:0% +me that worked on the automatic control + + + align:start position:0% +me that worked on the automatic control +system we didn't know what else to do + + align:start position:0% +system we didn't know what else to do + + + align:start position:0% +system we didn't know what else to do +we've done everything we could think of + + align:start position:0% +we've done everything we could think of + + + align:start position:0% +we've done everything we could think of +we suspected there were some unknown + + align:start position:0% +we suspected there were some unknown + + + align:start position:0% +we suspected there were some unknown +unknowns good old NASA term unknown + + align:start position:0% +unknowns good old NASA term unknown + + + align:start position:0% +unknowns good old NASA term unknown +unknowns but we didn't know what they + + align:start position:0% +unknowns but we didn't know what they + + + align:start position:0% +unknowns but we didn't know what they +were we didn't know where to test we + + align:start position:0% +were we didn't know where to test we + + + align:start position:0% +were we didn't know where to test we +didn't know how to test it so got to go + + align:start position:0% +didn't know how to test it so got to go + + + align:start position:0% +didn't know how to test it so got to go +light the torch and do it + + align:start position:0% +light the torch and do it + + + align:start position:0% +light the torch and do it +I don't think it took a lot + + align:start position:0% +I don't think it took a lot + + + align:start position:0% +I don't think it took a lot +of guts or neres I think it we I think + + align:start position:0% +of guts or neres I think it we I think + + + align:start position:0% +of guts or neres I think it we I think +we were pretty sure of + + align:start position:0% +we were pretty sure of + + + align:start position:0% +we were pretty sure of +ourselves now the Challenger accident + + align:start position:0% +ourselves now the Challenger accident + + + align:start position:0% +ourselves now the Challenger accident +and the Columbia accident are + + align:start position:0% +and the Columbia accident are + + + align:start position:0% +and the Columbia accident are +horrible tragedy there's no question + + align:start position:0% +horrible tragedy there's no question + + + align:start position:0% +horrible tragedy there's no question +about that but they shouldn't have + + align:start position:0% +about that but they shouldn't have + + + align:start position:0% +about that but they shouldn't have +happened and they they could have been + + align:start position:0% +happened and they they could have been + + + align:start position:0% +happened and they they could have been +prevented and that's the other thing you + + align:start position:0% +prevented and that's the other thing you + + + align:start position:0% +prevented and that's the other thing you +have to remember when you get into this + + align:start position:0% +have to remember when you get into this + + + align:start position:0% +have to remember when you get into this +business some of you if not all of you + + align:start position:0% +business some of you if not all of you + + + align:start position:0% +business some of you if not all of you +are going to be responsible for the + + align:start position:0% +are going to be responsible for the + + + align:start position:0% +are going to be responsible for the +lives of the people that are + + align:start position:0% +lives of the people that are + + + align:start position:0% +lives of the people that are +flying and the responsibility of the + + align:start position:0% +flying and the responsibility of the + + + align:start position:0% +flying and the responsibility of the +program because it may very well be + + align:start position:0% +program because it may very well be + + + align:start position:0% +program because it may very well be +something that just causes the space + + align:start position:0% +something that just causes the space + + + align:start position:0% +something that just causes the space +program to collapse in the United + + align:start position:0% +program to collapse in the United + + + align:start position:0% +program to collapse in the United +States and that is a tough + + align:start position:0% +States and that is a tough + + + align:start position:0% +States and that is a tough +task you don't learn that overnight you + + align:start position:0% +task you don't learn that overnight you + + + align:start position:0% +task you don't learn that overnight you +don't you just sort of have to learn to + + align:start position:0% +don't you just sort of have to learn to + + + align:start position:0% +don't you just sort of have to learn to +live with it + + align:start position:0% +live with it + + + align:start position:0% +live with it +and frankly you have to like + + align:start position:0% +and frankly you have to like + + + align:start position:0% +and frankly you have to like +it you have to like being in that + + align:start position:0% +it you have to like being in that + + + align:start position:0% +it you have to like being in that +position I had one of my flight + + align:start position:0% +position I had one of my flight + + + align:start position:0% +position I had one of my flight +directors who became very much affected + + align:start position:0% +directors who became very much affected + + + align:start position:0% +directors who became very much affected +by it + + align:start position:0% +by it + + + align:start position:0% +by it +mentally so so affected that he quit + + align:start position:0% +mentally so so affected that he quit + + + align:start position:0% +mentally so so affected that he quit +went became a + + align:start position:0% + + + + align:start position:0% + +psychiatrist didn't ever didn't ever + + align:start position:0% +psychiatrist didn't ever didn't ever + + + align:start position:0% +psychiatrist didn't ever didn't ever +form as a psychiatrist we got a got his + + align:start position:0% +form as a psychiatrist we got a got his + + + align:start position:0% +form as a psychiatrist we got a got his +degree in + + align:start position:0% +degree in + + + align:start position:0% +degree in +Psychiatry bill + + align:start position:0% +Psychiatry bill + + + align:start position:0% +Psychiatry bill +shacker you know one of my very closest + + align:start position:0% +shacker you know one of my very closest + + + align:start position:0% +shacker you know one of my very closest +friends now making me kind of Rich + + align:start position:0% +friends now making me kind of Rich + + + align:start position:0% +friends now making me kind of Rich +because we ow a lot of oil wells in + + align:start position:0% +because we ow a lot of oil wells in + + + align:start position:0% +because we ow a lot of oil wells in +Oklahoma + + align:start position:0% + + + + align:start position:0% + +together but it is it is a tough job but + + align:start position:0% +together but it is it is a tough job but + + + align:start position:0% +together but it is it is a tough job but +it is a marvelous + + align:start position:0% +it is a marvelous + + + align:start position:0% +it is a marvelous +job there is nothing I can think of + + align:start position:0% +job there is nothing I can think of + + + align:start position:0% +job there is nothing I can think of +including pitching in the World Series + + align:start position:0% + + + + align:start position:0% + +or winning the US + + align:start position:0% +or winning the US + + + align:start position:0% +or winning the US +Open it comes close to being in this + + align:start position:0% + + + + align:start position:0% + +business every day is a + + align:start position:0% +business every day is a + + + align:start position:0% +business every day is a +challenge every day is is hell and every + + align:start position:0% +challenge every day is is hell and every + + + align:start position:0% +challenge every day is is hell and every +day the best feeling you've ever had in + + align:start position:0% +day the best feeling you've ever had in + + + align:start position:0% +day the best feeling you've ever had in +your + + align:start position:0% +your + + + align:start position:0% +your +life it's how you feel every day you go + + align:start position:0% +life it's how you feel every day you go + + + align:start position:0% +life it's how you feel every day you go +through those you go through those + + align:start position:0% +through those you go through those + + + align:start position:0% +through those you go through those +trents almost every + + align:start position:0% +trents almost every + + + align:start position:0% +trents almost every +day so I highly recommend it to + + align:start position:0% +day so I highly recommend it to + + + align:start position:0% +day so I highly recommend it to +you I don't think you'll get + + align:start position:0% +you I don't think you'll get + + + align:start position:0% +you I don't think you'll get +rich till you retire and become a board + + align:start position:0% +rich till you retire and become a board + + + align:start position:0% +rich till you retire and become a board +member like some of us + + align:start position:0% +member like some of us + + + align:start position:0% +member like some of us +have uh but but before that uh you're + + align:start position:0% +have uh but but before that uh you're + + + align:start position:0% +have uh but but before that uh you're +not going to get rich but you're going + + align:start position:0% +not going to get rich but you're going + + + align:start position:0% +not going to get rich but you're going +to be happy every day and you're going + + align:start position:0% +to be happy every day and you're going + + + align:start position:0% +to be happy every day and you're going +to feel like you contributed every + + align:start position:0% +to feel like you contributed every + + + align:start position:0% +to feel like you contributed every +day and I don't know at least in our + + align:start position:0% +day and I don't know at least in our + + + align:start position:0% +day and I don't know at least in our +business anything better than that + + align:start position:0% +business anything better than that + + + align:start position:0% +business anything better than that +gentlemen all sitting here in front of + + align:start position:0% +gentlemen all sitting here in front of + + + align:start position:0% +gentlemen all sitting here in front of +me will will attest to that it's a great + + align:start position:0% +me will will attest to that it's a great + + + align:start position:0% +me will will attest to that it's a great +life with that I'll stop and take your + + align:start position:0% + + + + align:start position:0% + +questions sorry + + align:start position:0% + + + + align:start position:0% + +I turn + + align:start position:0% +I turn + + + align:start position:0% +I turn +hav turn any off where is the this is + + align:start position:0% +hav turn any off where is the this is + + + align:start position:0% +hav turn any off where is the this is +this is your chance uh pull a plug + + align:start position:0% +this is your chance uh pull a plug + + + align:start position:0% +this is your chance uh pull a plug +where's the + + align:start position:0% +where's the + + + align:start position:0% +where's the +plug get + + align:start position:0% +plug get + + + align:start position:0% +plug get +it + + align:start position:0% + + + + align:start position:0% + +than can you can you stand + + align:start position:0% +than can you can you stand + + + align:start position:0% +than can you can you stand +up would be the systems that you would + + align:start position:0% +up would be the systems that you would + + + align:start position:0% +up would be the systems that you would +think + + align:start position:0% +think + + + align:start position:0% +think +could use most Improvement on the + + align:start position:0% +could use most Improvement on the + + + align:start position:0% +could use most Improvement on the +shut with today's + + align:start position:0% +shut with today's + + + align:start position:0% +shut with today's +technology and as you see things what + + align:start position:0% +technology and as you see things what + + + align:start position:0% +technology and as you see things what +would be + + align:start position:0% + + + + align:start position:0% + +the my answer would my first answer + + align:start position:0% +the my answer would my first answer + + + align:start position:0% +the my answer would my first answer +would be + + align:start position:0% + + + + align:start position:0% + +political I improveed I'd improved the + + align:start position:0% +political I improveed I'd improved the + + + align:start position:0% +political I improveed I'd improved the +thermal protection + + align:start position:0% + + + + align:start position:0% + +system I don't think it has to be + + align:start position:0% +system I don't think it has to be + + + align:start position:0% +system I don't think it has to be +improved very much + + align:start position:0% +improved very much + + + align:start position:0% +improved very much +but it would sure get a lot of people + + align:start position:0% +but it would sure get a lot of people + + + align:start position:0% +but it would sure get a lot of people +off our backs if we improve the thermal + + align:start position:0% +off our backs if we improve the thermal + + + align:start position:0% +off our backs if we improve the thermal +protection system and and there are ways + + align:start position:0% +protection system and and there are ways + + + align:start position:0% +protection system and and there are ways +of doing that today you could you could + + align:start position:0% +of doing that today you could you could + + + align:start position:0% +of doing that today you could you could +take there some advancements in the + + align:start position:0% +take there some advancements in the + + + align:start position:0% +take there some advancements in the +state-of-the-art of materials probably + + align:start position:0% +state-of-the-art of materials probably + + + align:start position:0% +state-of-the-art of materials probably +in the way you attach to the the child + + align:start position:0% +in the way you attach to the the child + + + align:start position:0% +in the way you attach to the the child +to the machine probably the way you + + align:start position:0% +to the machine probably the way you + + + align:start position:0% +to the machine probably the way you +proof test it all those things I think + + align:start position:0% +proof test it all those things I think + + + align:start position:0% +proof test it all those things I think +would be where I would go + + align:start position:0% + + + + align:start position:0% + +first uh I'd put an El system + + align:start position:0% +first uh I'd put an El system + + + align:start position:0% +first uh I'd put an El system +in secondly as + + align:start position:0% +in secondly as + + + align:start position:0% +in secondly as +opposed and get rid of the + + align:start position:0% +opposed and get rid of the + + + align:start position:0% +opposed and get rid of the +Hydraulics because I think that's + + align:start position:0% +Hydraulics because I think that's + + + align:start position:0% +Hydraulics because I think that's +a uh a maintenance problem and I think + + align:start position:0% +a uh a maintenance problem and I think + + + align:start position:0% +a uh a maintenance problem and I think +that the apus are always going to be a + + align:start position:0% +that the apus are always going to be a + + + align:start position:0% +that the apus are always going to be a +problem because you're you got something + + align:start position:0% +problem because you're you got something + + + align:start position:0% +problem because you're you got something +that's turning up at 40,000 RPM a rotor + + align:start position:0% +that's turning up at 40,000 RPM a rotor + + + align:start position:0% +that's turning up at 40,000 RPM a rotor +that's about that big turning up 40,000 + + align:start position:0% +that's about that big turning up 40,000 + + + align:start position:0% +that's about that big turning up 40,000 +RPM and that because that 40,000 RPM + + align:start position:0% +RPM and that because that 40,000 RPM + + + align:start position:0% +RPM and that because that 40,000 RPM +actually instead of this diameter is now + + align:start position:0% +actually instead of this diameter is now + + + align:start position:0% +actually instead of this diameter is now +an eigh to quarter of an inch bigger + + align:start position:0% +an eigh to quarter of an inch bigger + + + align:start position:0% +an eigh to quarter of an inch bigger +because the metal is stretching under + + align:start position:0% +because the metal is stretching under + + + align:start position:0% +because the metal is stretching under +those conditions the valves we've had + + align:start position:0% +those conditions the valves we've had + + + align:start position:0% +those conditions the valves we've had +trouble with as you well know this the + + align:start position:0% +trouble with as you well know this the + + + align:start position:0% +trouble with as you well know this the +material where this thing is pulsing so + + align:start position:0% +material where this thing is pulsing so + + + align:start position:0% +material where this thing is pulsing so +i' I'd go to and and that's been these + + align:start position:0% +i' I'd go to and and that's been these + + + align:start position:0% +i' I'd go to and and that's been these +are nothing new there are designs there + + align:start position:0% +are nothing new there are designs there + + + align:start position:0% +are nothing new there are designs there +are electric motors there are Power + + align:start position:0% +are electric motors there are Power + + + align:start position:0% +are electric motors there are Power +Systems that would do it much better + + align:start position:0% +Systems that would do it much better + + + align:start position:0% +Systems that would do it much better +than the a than a hydraulic + + align:start position:0% +than the a than a hydraulic + + + align:start position:0% +than the a than a hydraulic +system uh + + align:start position:0% + + + + align:start position:0% + +those two systems I think are are + + align:start position:0% +those two systems I think are are + + + align:start position:0% +those two systems I think are are +primary + + align:start position:0% +primary + + + align:start position:0% +primary +now the other thing is you have to keep + + align:start position:0% +now the other thing is you have to keep + + + align:start position:0% +now the other thing is you have to keep +up with the stateof thee art and the + + align:start position:0% +up with the stateof thee art and the + + + align:start position:0% +up with the stateof thee art and the +problem you have one of the biggest + + align:start position:0% +problem you have one of the biggest + + + align:start position:0% +problem you have one of the biggest +problems you have in the shle today + + align:start position:0% +problems you have in the shle today + + + align:start position:0% +problems you have in the shle today +nobody builds the parts anymore you go + + align:start position:0% +nobody builds the parts anymore you go + + + align:start position:0% +nobody builds the parts anymore you go +to the manufacturers and they say oh + + align:start position:0% +to the manufacturers and they say oh + + + align:start position:0% +to the manufacturers and they say oh +stopped building that system 10 years + + align:start position:0% +stopped building that system 10 years + + + align:start position:0% +stopped building that system 10 years +ago so all the circuit boards everything + + align:start position:0% +ago so all the circuit boards everything + + + align:start position:0% +ago so all the circuit boards everything +is pass a and that sounds like well we + + align:start position:0% +is pass a and that sounds like well we + + + align:start position:0% +is pass a and that sounds like well we +just change the circuit board well + + align:start position:0% +just change the circuit board well + + + align:start position:0% +just change the circuit board well +that's that is a problem because the + + align:start position:0% +that's that is a problem because the + + + align:start position:0% +that's that is a problem because the +process specs are got to be looked at + + align:start position:0% +process specs are got to be looked at + + + align:start position:0% +process specs are got to be looked at +the uh sneak + + align:start position:0% +the uh sneak + + + align:start position:0% +the uh sneak +circuitry the sleak pths it got to be + + align:start position:0% +circuitry the sleak pths it got to be + + + align:start position:0% +circuitry the sleak pths it got to be +looked at because that was the thing + + align:start position:0% +looked at because that was the thing + + + align:start position:0% +looked at because that was the thing +that always got to us and bace flight + + align:start position:0% +that always got to us and bace flight + + + align:start position:0% +that always got to us and bace flight +was everything works fine in an noral + + align:start position:0% +was everything works fine in an noral + + + align:start position:0% +was everything works fine in an noral +thing but someday somebody turned + + align:start position:0% +thing but someday somebody turned + + + align:start position:0% +thing but someday somebody turned +something off and the thing glitched and + + align:start position:0% +something off and the thing glitched and + + + align:start position:0% +something off and the thing glitched and +you know it fired the retro rocket or + + align:start position:0% +you know it fired the retro rocket or + + + align:start position:0% +you know it fired the retro rocket or +something like that and uh so you have + + align:start position:0% +something like that and uh so you have + + + align:start position:0% +something like that and uh so you have +to be sure that when you do redesign the + + align:start position:0% +to be sure that when you do redesign the + + + align:start position:0% +to be sure that when you do redesign the +circuitry into the modern world all that + + align:start position:0% +circuitry into the modern world all that + + + align:start position:0% +circuitry into the modern world all that +it's properly + + align:start position:0% +it's properly + + + align:start position:0% +it's properly +done uh a lot of things you don't need + + align:start position:0% +done uh a lot of things you don't need + + + align:start position:0% +done uh a lot of things you don't need +on Space Shuttle problem you don't need + + align:start position:0% +on Space Shuttle problem you don't need + + + align:start position:0% +on Space Shuttle problem you don't need +the backup flight control system which + + align:start position:0% +the backup flight control system which + + + align:start position:0% +the backup flight control system which +is cost a lot of + + align:start position:0% +is cost a lot of + + + align:start position:0% +is cost a lot of +money uh and and then I think I the + + align:start position:0% +money uh and and then I think I the + + + align:start position:0% +money uh and and then I think I the +biggest thing I would do is force the + + align:start position:0% +biggest thing I would do is force the + + + align:start position:0% +biggest thing I would do is force the +system to use automated + + align:start position:0% +system to use automated + + + align:start position:0% +system to use automated +checkup that's where the money is I + + align:start position:0% +checkup that's where the money is I + + + align:start position:0% +checkup that's where the money is I +think in uh maintaining the Machining is + + align:start position:0% +think in uh maintaining the Machining is + + + align:start position:0% +think in uh maintaining the Machining is +the uh nobody is willing to use + + align:start position:0% +the uh nobody is willing to use + + + align:start position:0% +the uh nobody is willing to use +automatic checkup it's + + align:start position:0% +automatic checkup it's + + + align:start position:0% +automatic checkup it's +there and you could do it very easily + + align:start position:0% +there and you could do it very easily + + + align:start position:0% +there and you could do it very easily +but people who take nille are they need + + align:start position:0% +but people who take nille are they need + + + align:start position:0% +but people who take nille are they need +to be flight + + align:start position:0% +to be flight + + + align:start position:0% +to be flight +controllers uh what I mean by that + + align:start position:0% +controllers uh what I mean by that + + + align:start position:0% +controllers uh what I mean by that +is the people like C canav who who + + align:start position:0% +is the people like C canav who who + + + align:start position:0% +is the people like C canav who who +prepare and maintain the machine have a + + align:start position:0% +prepare and maintain the machine have a + + + align:start position:0% +prepare and maintain the machine have a +totally different approach to the space + + align:start position:0% +totally different approach to the space + + + align:start position:0% +totally different approach to the space +machine than the FL controllers do the + + align:start position:0% +machine than the FL controllers do the + + + align:start position:0% +machine than the FL controllers do the +people at DEC want it to be perfect when + + align:start position:0% +people at DEC want it to be perfect when + + + align:start position:0% +people at DEC want it to be perfect when +it's + + align:start position:0% +it's + + + align:start position:0% +it's +launched so when they do the checkout + + align:start position:0% +launched so when they do the checkout + + + align:start position:0% +launched so when they do the checkout +and it doesn't work right they go plug a + + align:start position:0% +and it doesn't work right they go plug a + + + align:start position:0% +and it doesn't work right they go plug a +new board in or they go put a new system + + align:start position:0% +new board in or they go put a new system + + + align:start position:0% +new board in or they go put a new system +in or change out the fuel cell a flight + + align:start position:0% +in or change out the fuel cell a flight + + + align:start position:0% +in or change out the fuel cell a flight +controller does not have that + + align:start position:0% +controller does not have that + + + align:start position:0% +controller does not have that +prerogative he's got to figure out how + + align:start position:0% +prerogative he's got to figure out how + + + align:start position:0% +prerogative he's got to figure out how +how do I live with what I've got and + + align:start position:0% +how do I live with what I've got and + + + align:start position:0% +how do I live with what I've got and +make the best of + + align:start position:0% +make the best of + + + align:start position:0% +make the best of +it I think that's the best attitude and + + align:start position:0% +it I think that's the best attitude and + + + align:start position:0% +it I think that's the best attitude and +you need more of that in the maintenance + + align:start position:0% +you need more of that in the maintenance + + + align:start position:0% +you need more of that in the maintenance +side of the of the things that I think + + align:start position:0% +side of the of the things that I think + + + align:start position:0% +side of the of the things that I think +the biggest that's where the biggest + + align:start position:0% +the biggest that's where the biggest + + + align:start position:0% +the biggest that's where the biggest +savings the biggest Improvement could be + + align:start position:0% +savings the biggest Improvement could be + + + align:start position:0% +savings the biggest Improvement could be +made in space + + align:start position:0% +made in space + + + align:start position:0% +made in space +shuttle the other thing I think about is + + align:start position:0% +shuttle the other thing I think about is + + + align:start position:0% +shuttle the other thing I think about is +the uh + + align:start position:0% +the uh + + + align:start position:0% +the uh +engine + + align:start position:0% +engine + + + align:start position:0% +engine +ssme I think if you derated the ssme so + + align:start position:0% +ssme I think if you derated the ssme so + + + align:start position:0% +ssme I think if you derated the ssme so +that the turnaround time on the engine + + align:start position:0% +that the turnaround time on the engine + + + align:start position:0% +that the turnaround time on the engine +and the reliability of the engine would + + align:start position:0% +and the reliability of the engine would + + + align:start position:0% +and the reliability of the engine would +go up + + align:start position:0% +go up + + + align:start position:0% +go up +significantly significantly if you + + align:start position:0% +significantly significantly if you + + + align:start position:0% +significantly significantly if you +derated the engine IE instead of asking + + align:start position:0% +derated the engine IE instead of asking + + + align:start position:0% +derated the engine IE instead of asking +it to put out8 every time you go to the + + align:start position:0% +it to put out8 every time you go to the + + + align:start position:0% +it to put out8 every time you go to the +space station because you're going up to + + align:start position:0% +space station because you're going up to + + + align:start position:0% +space station because you're going up to +the higher + + align:start position:0% +the higher + + + align:start position:0% +the higher +inclinations you just put a bigger and + + align:start position:0% +inclinations you just put a bigger and + + + align:start position:0% +inclinations you just put a bigger and +bigger head in it or whatever it is what + + align:start position:0% +bigger head in it or whatever it is what + + + align:start position:0% +bigger head in it or whatever it is what +it take whatever it takes to derate the + + align:start position:0% +it take whatever it takes to derate the + + + align:start position:0% +it take whatever it takes to derate the +engine make it run at 95% power was the + + align:start position:0% +engine make it run at 95% power was the + + + align:start position:0% +engine make it run at 95% power was the +thing to last forever to do + + align:start position:0% + + + + align:start position:0% + +that mention + + align:start position:0% +that mention + + + align:start position:0% +that mention +uh talk about going back to the and I + + align:start position:0% +uh talk about going back to the and I + + + align:start position:0% +uh talk about going back to the and I +was going to ask + + align:start position:0% + + + + align:start position:0% + +you couple of parts of the question one + + align:start position:0% +you couple of parts of the question one + + + align:start position:0% +you couple of parts of the question one +is what for two is it to go to the moon + + align:start position:0% +is what for two is it to go to the moon + + + align:start position:0% +is what for two is it to go to the moon +or is a stepping stone to do something + + align:start position:0% +or is a stepping stone to do something + + + align:start position:0% +or is a stepping stone to do something +else and then perhaps you could comment + + align:start position:0% +else and then perhaps you could comment + + + align:start position:0% +else and then perhaps you could comment +on what your prediction is for the Space + + align:start position:0% +on what your prediction is for the Space + + + align:start position:0% +on what your prediction is for the Space +Program in the + + align:start position:0% + + + + align:start position:0% + +future I go back to the + + align:start position:0% + + + + align:start position:0% + +Boon + + align:start position:0% + + + + align:start position:0% + +uh well I think that there are enough + + align:start position:0% +uh well I think that there are enough + + + align:start position:0% +uh well I think that there are enough +resources on the + + align:start position:0% +resources on the + + + align:start position:0% +resources on the +moon to make it economically viable + + align:start position:0% +moon to make it economically viable + + + align:start position:0% +moon to make it economically viable +number one number two I think you + + align:start position:0% +number one number two I think you + + + align:start position:0% +number one number two I think you +could uh develop enough electrical power + + align:start position:0% +could uh develop enough electrical power + + + align:start position:0% +could uh develop enough electrical power +on the + + align:start position:0% +on the + + + align:start position:0% +on the +moon to provide a + + align:start position:0% +moon to provide a + + + align:start position:0% +moon to provide a +uh enough power for the people that were + + align:start position:0% +uh enough power for the people that were + + + align:start position:0% +uh enough power for the people that were +going to live there and be stationed + + align:start position:0% +going to live there and be stationed + + + align:start position:0% +going to live there and be stationed +there permanently and it and you would + + align:start position:0% +there permanently and it and you would + + + align:start position:0% +there permanently and it and you would +do it on the back side by the way not on + + align:start position:0% +do it on the back side by the way not on + + + align:start position:0% +do it on the back side by the way not on +the front side because that's where you + + align:start position:0% +the front side because that's where you + + + align:start position:0% +the front side because that's where you +want it you would want your permanent + + align:start position:0% +want it you would want your permanent + + + align:start position:0% +want it you would want your permanent +base on the moon to be on the back side + + align:start position:0% +base on the moon to be on the back side + + + align:start position:0% +base on the moon to be on the back side +because it would be shielded from all + + align:start position:0% +because it would be shielded from all + + + align:start position:0% +because it would be shielded from all +the electronic signals from the earth so + + align:start position:0% +the electronic signals from the earth so + + + align:start position:0% +the electronic signals from the earth so +it's the best place in the world to look + + align:start position:0% +it's the best place in the world to look + + + align:start position:0% +it's the best place in the world to look +at the rest of the + + align:start position:0% +at the rest of the + + + align:start position:0% +at the rest of the +universe so I build my Bas bace on the + + align:start position:0% +universe so I build my Bas bace on the + + + align:start position:0% +universe so I build my Bas bace on the +back side of the moon + + align:start position:0% +back side of the moon + + + align:start position:0% +back side of the moon +and then I I believe there + + align:start position:0% +and then I I believe there + + + align:start position:0% +and then I I believe there +are possibilities although it's not + + align:start position:0% +are possibilities although it's not + + + align:start position:0% +are possibilities although it's not +technically sound yet but I believe + + align:start position:0% +technically sound yet but I believe + + + align:start position:0% +technically sound yet but I believe +there are possibilities of pro of + + align:start position:0% +there are possibilities of pro of + + + align:start position:0% +there are possibilities of pro of +providing enough electrical + + align:start position:0% +providing enough electrical + + + align:start position:0% +providing enough electrical +power to the Earth from the Moon that + + align:start position:0% +power to the Earth from the Moon that + + + align:start position:0% +power to the Earth from the Moon that +you could shut down every Power Plant in + + align:start position:0% +you could shut down every Power Plant in + + + align:start position:0% +you could shut down every Power Plant in +Europe you get that much electrical + + align:start position:0% +Europe you get that much electrical + + + align:start position:0% +Europe you get that much electrical +energy from the Moon and that would + + align:start position:0% +energy from the Moon and that would + + + align:start position:0% +energy from the Moon and that would +certainly + + align:start position:0% +certainly + + + align:start position:0% +certainly +offload the power requirements on the + + align:start position:0% +offload the power requirements on the + + + align:start position:0% +offload the power requirements on the +earth which are + + align:start position:0% +earth which are + + + align:start position:0% +earth which are +almost logarithmic aren't + + align:start position:0% +almost logarithmic aren't + + + align:start position:0% +almost logarithmic aren't +they uh China end up using more + + align:start position:0% +they uh China end up using more + + + align:start position:0% +they uh China end up using more +electrical to and we do shortly so we + + align:start position:0% +electrical to and we do shortly so we + + + align:start position:0% +electrical to and we do shortly so we +need electrical power and I think you + + align:start position:0% +need electrical power and I think you + + + align:start position:0% +need electrical power and I think you +could get that from the moon plus I + + align:start position:0% +could get that from the moon plus I + + + align:start position:0% +could get that from the moon plus I +think that + + align:start position:0% +think that + + + align:start position:0% +think that +the geophysicist and the + + align:start position:0% +the geophysicist and the + + + align:start position:0% +the geophysicist and the +geologists astrophysicists all can give + + align:start position:0% +geologists astrophysicists all can give + + + align:start position:0% +geologists astrophysicists all can give +you a thousand reasons why you should go + + align:start position:0% +you a thousand reasons why you should go + + + align:start position:0% +you a thousand reasons why you should go +back to the Moon because it's still they + + align:start position:0% +back to the Moon because it's still they + + + align:start position:0% +back to the Moon because it's still they +what what + + align:start position:0% +what what + + + align:start position:0% +what what +uh L Yuri what you Mr what Professor + + align:start position:0% +uh L Yuri what you Mr what Professor + + + align:start position:0% +uh L Yuri what you Mr what Professor +Yuri said it is the Ros Rosetta Stone of + + align:start position:0% +Yuri said it is the Ros Rosetta Stone of + + + align:start position:0% +Yuri said it is the Ros Rosetta Stone of +the universe there's more to be known + + align:start position:0% +the universe there's more to be known + + + align:start position:0% +the universe there's more to be known +from the Moon about the + + align:start position:0% +from the Moon about the + + + align:start position:0% +from the Moon about the +Earth than you can ever get out of the + + align:start position:0% +Earth than you can ever get out of the + + + align:start position:0% +Earth than you can ever get out of the +earth so it's still very useful to go + + align:start position:0% +earth so it's still very useful to go + + + align:start position:0% +earth so it's still very useful to go +back there from the scientific point of + + align:start position:0% +back there from the scientific point of + + + align:start position:0% +back there from the scientific point of +view plus the engineering and economics + + align:start position:0% +view plus the engineering and economics + + + align:start position:0% +view plus the engineering and economics +of + + align:start position:0% +of + + + align:start position:0% +of +it uh + + align:start position:0% + + + + align:start position:0% + +I think it's I I didn't say it but I + + align:start position:0% +I think it's I I didn't say it but I + + + align:start position:0% +I think it's I I didn't say it but I +think because I'm wasn't sure you wanted + + align:start position:0% +think because I'm wasn't sure you wanted + + + align:start position:0% +think because I'm wasn't sure you wanted +to have such discussion but uh I will I + + align:start position:0% +to have such discussion but uh I will I + + + align:start position:0% +to have such discussion but uh I will I +think it's a travesty that we aren't + + align:start position:0% +think it's a travesty that we aren't + + + align:start position:0% +think it's a travesty that we aren't +doing it with the space shuttle and the + + align:start position:0% +doing it with the space shuttle and the + + + align:start position:0% +doing it with the space shuttle and the +space + + align:start position:0% +space + + + align:start position:0% +space +station to go back to the moon or to go + + align:start position:0% +station to go back to the moon or to go + + + align:start position:0% +station to go back to the moon or to go +to + + align:start position:0% +to + + + align:start position:0% +to +Mars why do I think that + + align:start position:0% +Mars why do I think that + + + align:start position:0% +Mars why do I think that +because if you go to either case I I + + align:start position:0% +because if you go to either case I I + + + align:start position:0% +because if you go to either case I I +don't understand why you want to build + + align:start position:0% +don't understand why you want to build + + + align:start position:0% +don't understand why you want to build +an earth entering vehicle + + align:start position:0% +an earth entering vehicle + + + align:start position:0% +an earth entering vehicle +to go to the moon what you want is an + + align:start position:0% +to go to the moon what you want is an + + + align:start position:0% +to go to the moon what you want is an +inter inter interplanetary + + align:start position:0% +inter inter interplanetary + + + align:start position:0% +inter inter interplanetary +spacecraft why does it have to have a + + align:start position:0% +spacecraft why does it have to have a + + + align:start position:0% +spacecraft why does it have to have a +heat shield why does it have to have + + align:start position:0% +heat shield why does it have to have + + + align:start position:0% +heat shield why does it have to have +parachutes why does it have or some kind + + align:start position:0% +parachutes why does it have or some kind + + + align:start position:0% +parachutes why does it have or some kind +of Landing capability why not just go to + + align:start position:0% +of Landing capability why not just go to + + + align:start position:0% +of Landing capability why not just go to +and from Earth orbit and the space + + align:start position:0% +and from Earth orbit and the space + + + align:start position:0% +and from Earth orbit and the space +shuttle the + + align:start position:0% +shuttle the + + + align:start position:0% +shuttle the +greatest machine for carrying things to + + align:start position:0% +greatest machine for carrying things to + + + align:start position:0% +greatest machine for carrying things to +and + + align:start position:0% +and + + + align:start position:0% +and +from orbit that's ever been thought of + + align:start position:0% +from orbit that's ever been thought of + + + align:start position:0% +from orbit that's ever been thought of +and the one they're going to build + + align:start position:0% +and the one they're going to build + + + align:start position:0% +and the one they're going to build +is even if it's an unmanned vehicle it's + + align:start position:0% +is even if it's an unmanned vehicle it's + + + align:start position:0% +is even if it's an unmanned vehicle it's +still going to have awful lot of + + align:start position:0% +still going to have awful lot of + + + align:start position:0% +still going to have awful lot of +complexity to it so I and I think that + + align:start position:0% +complexity to it so I and I think that + + + align:start position:0% +complexity to it so I and I think that +you've made the space shuttle + + align:start position:0% +you've made the space shuttle + + + align:start position:0% +you've made the space shuttle +economically viable which nobody thinks + + align:start position:0% +economically viable which nobody thinks + + + align:start position:0% +economically viable which nobody thinks +you can and maybe Chris Craft is the + + align:start position:0% +you can and maybe Chris Craft is the + + + align:start position:0% +you can and maybe Chris Craft is the +only one that thinks you can and you + + align:start position:0% +only one that thinks you can and you + + + align:start position:0% +only one that thinks you can and you +know that's if that's true that's true I + + align:start position:0% +know that's if that's true that's true I + + + align:start position:0% +know that's if that's true that's true I +don't think that way I think the space + + align:start position:0% +don't think that way I think the space + + + align:start position:0% +don't think that way I think the space +shuttle is an an economically viable + + align:start position:0% +shuttle is an an economically viable + + + align:start position:0% +shuttle is an an economically viable +machine and I so it's a travesty to me + + align:start position:0% +machine and I so it's a travesty to me + + + align:start position:0% +machine and I so it's a travesty to me +to throw it away + + align:start position:0% +to throw it away + + + align:start position:0% +to throw it away +and the space station could be used as + + align:start position:0% +and the space station could be used as + + + align:start position:0% +and the space station could be used as +the place where you assemble all this + + align:start position:0% +the place where you assemble all this + + + align:start position:0% +the place where you assemble all this +stuff and everybody says well it's up + + align:start position:0% +stuff and everybody says well it's up + + + align:start position:0% +stuff and everybody says well it's up +it's at the wrong inclination yes it is + + align:start position:0% +it's at the wrong inclination yes it is + + + align:start position:0% +it's at the wrong inclination yes it is +at the wrong inclination we were foolish + + align:start position:0% +at the wrong inclination we were foolish + + + align:start position:0% +at the wrong inclination we were foolish +to put it there in the first place but + + align:start position:0% +to put it there in the first place but + + + align:start position:0% +to put it there in the first place but +that's where it is + + align:start position:0% +that's where it is + + + align:start position:0% +that's where it is +but uh every time I had a little bit of + + align:start position:0% +but uh every time I had a little bit of + + + align:start position:0% +but uh every time I had a little bit of +fuel left over I inch it down a little + + align:start position:0% +fuel left over I inch it down a little + + + align:start position:0% +fuel left over I inch it down a little +bit you know and the first thing you + + align:start position:0% +bit you know and the first thing you + + + align:start position:0% +bit you know and the first thing you +know it'd be down to 28 and a half + + align:start position:0% +know it'd be down to 28 and a half + + + align:start position:0% +know it'd be down to 28 and a half +degrees and it wouldn't cost today it + + align:start position:0% +degrees and it wouldn't cost today it + + + align:start position:0% +degrees and it wouldn't cost today it +cost you 15,000 + + align:start position:0% +cost you 15,000 + + + align:start position:0% +cost you 15,000 +of payload to go to the space station + + align:start position:0% +of payload to go to the space station + + + align:start position:0% +of payload to go to the space station +and that's a travesty too so you would + + align:start position:0% +and that's a travesty too so you would + + + align:start position:0% +and that's a travesty too so you would +want to do that continuously but uh so + + align:start position:0% +want to do that continuously but uh so + + + align:start position:0% +want to do that continuously but uh so +i' I'd use the space station as my + + align:start position:0% +i' I'd use the space station as my + + + align:start position:0% +i' I'd use the space station as my +assembly point and I'd use the space sh + + align:start position:0% +assembly point and I'd use the space sh + + + align:start position:0% +assembly point and I'd use the space sh +shuttle as the machine to go there and + + align:start position:0% +shuttle as the machine to go there and + + + align:start position:0% +shuttle as the machine to go there and +then I'd build myself a bunch of + + align:start position:0% +then I'd build myself a bunch of + + + align:start position:0% +then I'd build myself a bunch of +interplanetary spacecraft to go to and + + align:start position:0% +interplanetary spacecraft to go to and + + + align:start position:0% +interplanetary spacecraft to go to and +from the the moon and Mars and when I + + align:start position:0% +from the the moon and Mars and when I + + + align:start position:0% +from the the moon and Mars and when I +did that uh I'd be smart enough to build + + align:start position:0% +did that uh I'd be smart enough to build + + + align:start position:0% +did that uh I'd be smart enough to build +all these new fangles + + align:start position:0% +all these new fangles + + + align:start position:0% +all these new fangles +structures inflatable structures Etc + + align:start position:0% +structures inflatable structures Etc + + + align:start position:0% +structures inflatable structures Etc +which you could use not only as the in + + align:start position:0% +which you could use not only as the in + + + align:start position:0% +which you could use not only as the in +prioritary spacecraft but you use that + + align:start position:0% +prioritary spacecraft but you use that + + + align:start position:0% +prioritary spacecraft but you use that +place where you would live on the moon + + align:start position:0% +place where you would live on the moon + + + align:start position:0% +place where you would live on the moon +so I I think it has a better approach + + align:start position:0% +so I I think it has a better approach + + + align:start position:0% +so I I think it has a better approach +from an engineering point of + + align:start position:0% +from an engineering point of + + + align:start position:0% +from an engineering point of +view whether that's the + + align:start position:0% +view whether that's the + + + align:start position:0% +view whether that's the +political way to sell the program Mr + + align:start position:0% +political way to sell the program Mr + + + align:start position:0% +political way to sell the program Mr +Griffin has got to do that I mean that's + + align:start position:0% +Griffin has got to do that I mean that's + + + align:start position:0% +Griffin has got to do that I mean that's +what his job is fortunately it's not + + align:start position:0% +what his job is fortunately it's not + + + align:start position:0% +what his job is fortunately it's not +mine I was to be the Deputy + + align:start position:0% +mine I was to be the Deputy + + + align:start position:0% +mine I was to be the Deputy +Administrator and the administrator of + + align:start position:0% +Administrator and the administrator of + + + align:start position:0% +Administrator and the administrator of +NASA several + + align:start position:0% +NASA several + + + align:start position:0% +NASA several +times and you can hear the way I talk + + align:start position:0% +times and you can hear the way I talk + + + align:start position:0% +times and you can hear the way I talk +here I to last about six days to six + + align:start position:0% + + + + align:start position:0% + +months uh what do I think about + + align:start position:0% +months uh what do I think about + + + align:start position:0% +months uh what do I think about +tomorrow's what do I think about the + + align:start position:0% +tomorrow's what do I think about the + + + align:start position:0% +tomorrow's what do I think about the +possibilities of today's + + align:start position:0% + + + + align:start position:0% + +plans hate to say this but I think it's + + align:start position:0% +plans hate to say this but I think it's + + + align:start position:0% +plans hate to say this but I think it's +going to + + align:start position:0% +going to + + + align:start position:0% +going to +fail I don't think it'll work + + align:start position:0% +fail I don't think it'll work + + + align:start position:0% +fail I don't think it'll work +I don't think the program + + align:start position:0% +I don't think the program + + + align:start position:0% +I don't think the program +as + + align:start position:0% +as + + + align:start position:0% +as +uh stipulated today is the way to do + + align:start position:0% +uh stipulated today is the way to do + + + align:start position:0% +uh stipulated today is the way to do +it and I don't think the political + + align:start position:0% +it and I don't think the political + + + align:start position:0% +it and I don't think the political +climate is such that the budgetary + + align:start position:0% +climate is such that the budgetary + + + align:start position:0% +climate is such that the budgetary +support will be + + align:start position:0% +support will be + + + align:start position:0% +support will be +provided and I hope I'm + + align:start position:0% +provided and I hope I'm + + + align:start position:0% +provided and I hope I'm +wrong I don't think + + align:start position:0% + + + + align:start position:0% + +I pardon + + align:start position:0% +I pardon + + + align:start position:0% +I pardon +now hell Chinese are 50 years from the + + align:start position:0% +now hell Chinese are 50 years from the + + + align:start position:0% +now hell Chinese are 50 years from the +going to the Moon they can't buy it from + + align:start position:0% +going to the Moon they can't buy it from + + + align:start position:0% +going to the Moon they can't buy it from +Russia that's what they're doing today + + align:start position:0% +Russia that's what they're doing today + + + align:start position:0% +Russia that's what they're doing today +they're buying all the technology to put + + align:start position:0% +they're buying all the technology to put + + + align:start position:0% +they're buying all the technology to put +man in space from + + align:start position:0% + + + + align:start position:0% + +Russia you know the thought that makes + + align:start position:0% +Russia you know the thought that makes + + + align:start position:0% +Russia you know the thought that makes +me think well the Russians still using + + align:start position:0% +me think well the Russians still using + + + align:start position:0% +me think well the Russians still using +the same spacecraft with slight + + align:start position:0% +the same spacecraft with slight + + + align:start position:0% +the same spacecraft with slight +variation that they put gagaran up in + + align:start position:0% +variation that they put gagaran up in + + + align:start position:0% +variation that they put gagaran up in +19 61 literally it's pretty close to it + + align:start position:0% +19 61 literally it's pretty close to it + + + align:start position:0% +19 61 literally it's pretty close to it +I've sat in it have you sat in it + + align:start position:0% +I've sat in it have you sat in it + + + align:start position:0% +I've sat in it have you sat in it +FR sit in it like + + align:start position:0% +FR sit in it like + + + align:start position:0% +FR sit in it like +this uh but they used it over and over + + align:start position:0% +this uh but they used it over and over + + + align:start position:0% +this uh but they used it over and over +and over and over again the + + align:start position:0% + + + + align:start position:0% + +B52 been used over and over again it's + + align:start position:0% +B52 been used over and over again it's + + + align:start position:0% +B52 been used over and over again it's +got a new Wing got new electronics got + + align:start position:0% +got a new Wing got new electronics got + + + align:start position:0% +got a new Wing got new electronics got +new + + align:start position:0% +new + + + align:start position:0% +new +bombs got new everything on it the only + + align:start position:0% +bombs got new everything on it the only + + + align:start position:0% +bombs got new everything on it the only +thing that's the same is the + + align:start position:0% +thing that's the same is the + + + align:start position:0% +thing that's the same is the +configuration got new engines had new + + align:start position:0% +configuration got new engines had new + + + align:start position:0% +configuration got new engines had new +engines probably five times in it's + + align:start position:0% +engines probably five times in it's + + + align:start position:0% +engines probably five times in it's +lifetime that's what we ought to be + + align:start position:0% +lifetime that's what we ought to be + + + align:start position:0% +lifetime that's what we ought to be +doing with the + + align:start position:0% +doing with the + + + align:start position:0% +doing with the +shuttle isn't it why we seem to have + + align:start position:0% +shuttle isn't it why we seem to have + + + align:start position:0% +shuttle isn't it why we seem to have +this great propensity in this country + + align:start position:0% +this great propensity in this country + + + align:start position:0% +this great propensity in this country +for building something wonderful and + + align:start position:0% +for building something wonderful and + + + align:start position:0% +for building something wonderful and +great and high performance and then + + align:start position:0% +great and high performance and then + + + align:start position:0% +great and high performance and then +throwing it + + align:start position:0% +throwing it + + + align:start position:0% +throwing it +away you know we put up the sky lab + + align:start position:0% +away you know we put up the sky lab + + + align:start position:0% +away you know we put up the sky lab +wonderful throw it away don't build + + align:start position:0% +wonderful throw it away don't build + + + align:start position:0% +wonderful throw it away don't build +anymore build a Saturn five + + align:start position:0% +anymore build a Saturn five + + + align:start position:0% +anymore build a Saturn five +will it put 200,000 lbs on + + align:start position:0% +will it put 200,000 lbs on + + + align:start position:0% +will it put 200,000 lbs on +it to the moon it's rotting away at say + + align:start position:0% +it to the moon it's rotting away at say + + + align:start position:0% +it to the moon it's rotting away at say +Johnson space c they got so mad at + + align:start position:0% +Johnson space c they got so mad at + + + align:start position:0% +Johnson space c they got so mad at +people the the trekkies in the country + + align:start position:0% +people the the trekkies in the country + + + align:start position:0% +people the the trekkies in the country +got so mad you at the Johnson Space + + align:start position:0% +got so mad you at the Johnson Space + + + align:start position:0% +got so mad you at the Johnson Space +Center and made them build a hanger to + + align:start position:0% +Center and made them build a hanger to + + + align:start position:0% +Center and made them build a hanger to +put it in so it wouldn't brought + + align:start position:0% +put it in so it wouldn't brought + + + align:start position:0% +put it in so it wouldn't brought +anymore we build a space station we're + + align:start position:0% +anymore we build a space station we're + + + align:start position:0% +anymore we build a space station we're +throwing it away we build a space + + align:start position:0% +throwing it away we build a space + + + align:start position:0% +throwing it away we build a space +shuttle we're throwing it + + align:start position:0% +shuttle we're throwing it + + + align:start position:0% +shuttle we're throwing it +away golly my mother would + + align:start position:0% + + + + align:start position:0% + +bananas we had leftovers at almost every + + align:start position:0% +bananas we had leftovers at almost every + + + align:start position:0% +bananas we had leftovers at almost every +other + + align:start position:0% +other + + + align:start position:0% +other +meal I know that's TR but don't you + + align:start position:0% +meal I know that's TR but don't you + + + align:start position:0% +meal I know that's TR but don't you +think that's + + align:start position:0% +think that's + + + align:start position:0% +think that's +one + + align:start position:0% +one + + + align:start position:0% +one +foolishness do things that way I think + + align:start position:0% +foolishness do things that way I think + + + align:start position:0% +foolishness do things that way I think +it + + align:start position:0% +it + + + align:start position:0% +it +is that you know we did learn from from + + align:start position:0% +is that you know we did learn from from + + + align:start position:0% +is that you know we did learn from from +space FL that everybody seemed to learn + + align:start position:0% +space FL that everybody seemed to learn + + + align:start position:0% +space FL that everybody seemed to learn +from everybody else's experiences that + + align:start position:0% +from everybody else's experiences that + + + align:start position:0% +from everybody else's experiences that +was an amazing fact than me in the early + + align:start position:0% +was an amazing fact than me in the early + + + align:start position:0% +was an amazing fact than me in the early +days particularly the astronauts + + align:start position:0% +days particularly the astronauts + + + align:start position:0% +days particularly the astronauts +would each one that flew was so much + + align:start position:0% +would each one that flew was so much + + + align:start position:0% +would each one that flew was so much +better than the one before knew how to + + align:start position:0% +better than the one before knew how to + + + align:start position:0% +better than the one before knew how to +do the job better than the one before + + align:start position:0% +do the job better than the one before + + + align:start position:0% +do the job better than the one before +and made it so much easier for them and + + align:start position:0% +and made it so much easier for them and + + + align:start position:0% +and made it so much easier for them and +they you know all of those things were + + align:start position:0% +they you know all of those things were + + + align:start position:0% +they you know all of those things were +you could see yourself advancing and + + align:start position:0% +you could see yourself advancing and + + + align:start position:0% +you could see yourself advancing and +it's they just built on this experience + + align:start position:0% +it's they just built on this experience + + + align:start position:0% +it's they just built on this experience +of each man and I don't know how they + + align:start position:0% +of each man and I don't know how they + + + align:start position:0% +of each man and I don't know how they +transmitted that to each other they + + align:start position:0% +transmitted that to each other they + + + align:start position:0% +transmitted that to each other they +didn't obviously because they didn't + + align:start position:0% +didn't obviously because they didn't + + + align:start position:0% +didn't obviously because they didn't +have a brain connection but + + align:start position:0% +have a brain connection but + + + align:start position:0% +have a brain connection but +that's the way we ought to be doing here + + align:start position:0% +that's the way we ought to be doing here + + + align:start position:0% +that's the way we ought to be doing here +we got all these things that we we build + + align:start position:0% +we got all these things that we we build + + + align:start position:0% +we got all these things that we we build +and then throw away and don't take + + align:start position:0% +and then throw away and don't take + + + align:start position:0% +and then throw away and don't take +advantage of that doesn't make a lot of + + align:start position:0% +advantage of that doesn't make a lot of + + + align:start position:0% +advantage of that doesn't make a lot of +sense to me now I know there are + + align:start position:0% +sense to me now I know there are + + + align:start position:0% +sense to me now I know there are +politics involved and that's the reason + + align:start position:0% +politics involved and that's the reason + + + align:start position:0% +politics involved and that's the reason +I said you have to take into account of + + align:start position:0% +I said you have to take into account of + + + align:start position:0% +I said you have to take into account of +politics when can you get the money how + + align:start position:0% +politics when can you get the money how + + + align:start position:0% +politics when can you get the money how +do you convince people that you need to + + align:start position:0% +do you convince people that you need to + + + align:start position:0% +do you convince people that you need to +do things what does it do to the jobs + + align:start position:0% +do things what does it do to the jobs + + + align:start position:0% +do things what does it do to the jobs +situation how does it affect each + + align:start position:0% +situation how does it affect each + + + align:start position:0% +situation how does it affect each +senators and each congressman state in + + align:start position:0% +senators and each congressman state in + + + align:start position:0% +senators and each congressman state in +terms of the money that you bring into + + align:start position:0% +terms of the money that you bring into + + + align:start position:0% +terms of the money that you bring into +that area and that so etc etc we built + + align:start position:0% +that area and that so etc etc we built + + + align:start position:0% +that area and that so etc etc we built +we built the Space Shuttle we had a + + align:start position:0% +we built the Space Shuttle we had a + + + align:start position:0% +we built the Space Shuttle we had a +contract in every state in the Union + + align:start position:0% +contract in every state in the Union + + + align:start position:0% +contract in every state in the Union +except + + align:start position:0% +except + + + align:start position:0% +except +Alaska and we did that on + + align:start position:0% + + + + align:start position:0% + +purpose I just have to go to all a Aon + + align:start position:0% +purpose I just have to go to all a Aon + + + align:start position:0% +purpose I just have to go to all a Aon +and I flew to every one of those there + + align:start position:0% +and I flew to every one of those there + + + align:start position:0% +and I flew to every one of those there + + align:start position:0% + + + align:start position:0% +major subcontractors in the shuttle and + + align:start position:0% +major subcontractors in the shuttle and + + + align:start position:0% +major subcontractors in the shuttle and +they were all over the country and we go + + align:start position:0% +they were all over the country and we go + + + align:start position:0% +they were all over the country and we go +visit them at least three or four times + + align:start position:0% +visit them at least three or four times + + + align:start position:0% +visit them at least three or four times +in a couple + + align:start position:0% +in a couple + + + align:start position:0% +in a couple +years so the politics has to be there we + + align:start position:0% +years so the politics has to be there we + + + align:start position:0% +years so the politics has to be there we +were lucky in Apollo the I call it the + + align:start position:0% +were lucky in Apollo the I call it the + + + align:start position:0% +were lucky in Apollo the I call it the +conjunction of the stars and the + + align:start position:0% +conjunction of the stars and the + + + align:start position:0% +conjunction of the stars and the +conjunction of the + + align:start position:0% + + + + align:start position:0% + +politics I want I want to tell you + + align:start position:0% +politics I want I want to tell you + + + align:start position:0% +politics I want I want to tell you +that's a story I've meant to + + align:start position:0% +that's a story I've meant to + + + align:start position:0% +that's a story I've meant to +tell uh in about + + align:start position:0% + + + + align:start position:0% + +1978 we 77 + + align:start position:0% +1978 we 77 + + + align:start position:0% +1978 we 77 +may we were really behind the power + + align:start position:0% +may we were really behind the power + + + align:start position:0% +may we were really behind the power +curve on the budget for the + + align:start position:0% +curve on the budget for the + + + align:start position:0% +curve on the budget for the +shuttle we had been pushing a bow wave + + align:start position:0% +shuttle we had been pushing a bow wave + + + align:start position:0% +shuttle we had been pushing a bow wave +of about + + align:start position:0% + + + + align:start position:0% + +10% less funds than we needed each year + + align:start position:0% +10% less funds than we needed each year + + + align:start position:0% +10% less funds than we needed each year +so that in about that time period we + + align:start position:0% +so that in about that time period we + + + align:start position:0% +so that in about that time period we +needed if we were going to have any + + align:start position:0% +needed if we were going to have any + + + align:start position:0% +needed if we were going to have any +semblance of making a + + align:start position:0% +semblance of making a + + + align:start position:0% +semblance of making a +1980 or 81 First Flight we needed $600 + + align:start position:0% +1980 or 81 First Flight we needed $600 + + + align:start position:0% +1980 or 81 First Flight we needed $600 +million doll + + align:start position:0% +million doll + + + align:start position:0% +million doll +supplement and about that much per year + + align:start position:0% +supplement and about that much per year + + + align:start position:0% +supplement and about that much per year +more than we were + + align:start position:0% +more than we were + + + align:start position:0% +more than we were +getting and NASA had this big meeting uh + + align:start position:0% +getting and NASA had this big meeting uh + + + align:start position:0% +getting and NASA had this big meeting uh +down at the Johnson Space Center and we + + align:start position:0% +down at the Johnson Space Center and we + + + align:start position:0% +down at the Johnson Space Center and we +all talked about what the problems were + + align:start position:0% +all talked about what the problems were + + + align:start position:0% +all talked about what the problems were +and how we going to meet that and + + align:start position:0% +and how we going to meet that and + + + align:start position:0% +and how we going to meet that and +everybody absolutely all the politics + + align:start position:0% +everybody absolutely all the politics + + + align:start position:0% +everybody absolutely all the politics +said you can't go ask for a supplement + + align:start position:0% +said you can't go ask for a supplement + + + align:start position:0% +said you can't go ask for a supplement +you can't go ask the Congress for any + + align:start position:0% +you can't go ask the Congress for any + + + align:start position:0% +you can't go ask the Congress for any +more you can't go to the White House and + + align:start position:0% +more you can't go to the White House and + + + align:start position:0% +more you can't go to the White House and +say we need more money so you may just + + align:start position:0% +say we need more money so you may just + + + align:start position:0% +say we need more money so you may just +have to turn this thing into an X15 + + align:start position:0% +have to turn this thing into an X15 + + + align:start position:0% +have to turn this thing into an X15 +project a research project project first + + align:start position:0% +project a research project project first + + + align:start position:0% +project a research project project first +shuttle flight will be whenever we can + + align:start position:0% +shuttle flight will be whenever we can + + + align:start position:0% +shuttle flight will be whenever we can +build it and it'll just be a test + + align:start position:0% +build it and it'll just be a test + + + align:start position:0% +build it and it'll just be a test +vehicle so we were all very downhearted + + align:start position:0% +vehicle so we were all very downhearted + + + align:start position:0% +vehicle so we were all very downhearted +about + + align:start position:0% +about + + + align:start position:0% +about +that Mr Frost who was then the + + align:start position:0% +that Mr Frost who was then the + + + align:start position:0% +that Mr Frost who was then the +administrator Dr Frost who was then the + + align:start position:0% +administrator Dr Frost who was then the + + + align:start position:0% +administrator Dr Frost who was then the +administrator went up to the White House + + align:start position:0% +administrator went up to the White House + + + align:start position:0% +administrator went up to the White House +about three days later and Carter who + + align:start position:0% +about three days later and Carter who + + + align:start position:0% +about three days later and Carter who +was the president called him in and he + + align:start position:0% +was the president called him in and he + + + align:start position:0% +was the president called him in and he +said I want to tell you how wonderful + + align:start position:0% +said I want to tell you how wonderful + + + align:start position:0% +said I want to tell you how wonderful +that space shuttle + + align:start position:0% +that space shuttle + + + align:start position:0% +that space shuttle +is and frost + + align:start position:0% +is and frost + + + align:start position:0% +is and frost +you know he he said I could feel myself + + align:start position:0% +you know he he said I could feel myself + + + align:start position:0% +you know he he said I could feel myself +tightened up and he said you know I just + + align:start position:0% +tightened up and he said you know I just + + + align:start position:0% +tightened up and he said you know I just +had this meeting with the Russians at + + align:start position:0% +had this meeting with the Russians at + + + align:start position:0% +had this meeting with the Russians at +the salt + + align:start position:0% +the salt + + + align:start position:0% +the salt +talks what it whatever salt + + align:start position:0% +talks what it whatever salt + + + align:start position:0% +talks what it whatever salt +meant and I was pointing out to them + + align:start position:0% +meant and I was pointing out to them + + + align:start position:0% +meant and I was pointing out to them +that we were building this marvelous new + + align:start position:0% +that we were building this marvelous new + + + align:start position:0% +that we were building this marvelous new +space machine and we were going to do + + align:start position:0% +space machine and we were going to do + + + align:start position:0% +space machine and we were going to do +all be able to do all kinds of things + + align:start position:0% +all be able to do all kinds of things + + + align:start position:0% +all be able to do all kinds of things +with it we're going to be able to fly + + align:start position:0% +with it we're going to be able to fly + + + align:start position:0% +with it we're going to be able to fly +over Russia look at the + + align:start position:0% +over Russia look at the + + + align:start position:0% +over Russia look at the +world and uh he said it carried the + + align:start position:0% +world and uh he said it carried the + + + align:start position:0% +world and uh he said it carried the +day in Fr says oh my + + align:start position:0% +day in Fr says oh my + + + align:start position:0% +day in Fr says oh my +God what is NASA going to do about that + + align:start position:0% +God what is NASA going to do about that + + + align:start position:0% +God what is NASA going to do about that +came back thought about it a few days + + align:start position:0% +came back thought about it a few days + + + align:start position:0% +came back thought about it a few days +and he went back to see the + + align:start position:0% +and he went back to see the + + + align:start position:0% +and he went back to see the +president he said Mr President I have to + + align:start position:0% +president he said Mr President I have to + + + align:start position:0% +president he said Mr President I have to +tell you this shuttle is in trouble we + + align:start position:0% +tell you this shuttle is in trouble we + + + align:start position:0% +tell you this shuttle is in trouble we +don't have the money we're not going to + + align:start position:0% +don't have the money we're not going to + + + align:start position:0% +don't have the money we're not going to +make the launch dates it's questionable + + align:start position:0% +make the launch dates it's questionable + + + align:start position:0% +make the launch dates it's questionable +whether we can even build a machine at + + align:start position:0% +whether we can even build a machine at + + + align:start position:0% +whether we can even build a machine at +this point in time because we haven't + + align:start position:0% +this point in time because we haven't + + + align:start position:0% +this point in time because we haven't +built the thermal protection since we + + align:start position:0% +built the thermal protection since we + + + align:start position:0% +built the thermal protection since we +didn't had the factory built yet to + + align:start position:0% +didn't had the factory built yet to + + + align:start position:0% +didn't had the factory built yet to +build the tiles + + align:start position:0% +build the tiles + + + align:start position:0% +build the tiles +Mr car said how much do you + + align:start position:0% + + + + align:start position:0% + +need how much do you + + align:start position:0% +need how much do you + + + align:start position:0% +need how much do you +need and he said well I think we need + + align:start position:0% +need and he said well I think we need + + + align:start position:0% +need and he said well I think we need +about $600 million this year + + align:start position:0% +about $600 million this year + + + align:start position:0% +about $600 million this year +and uh I think we'll need about $400 + + align:start position:0% +and uh I think we'll need about $400 + + + align:start position:0% +and uh I think we'll need about $400 +million a year that was a wild get that + + align:start position:0% +million a year that was a wild get that + + + align:start position:0% +million a year that was a wild get that +was a wag on Dr fr's part and the + + align:start position:0% +was a wag on Dr fr's part and the + + + align:start position:0% +was a wag on Dr fr's part and the +President says you'll get it + + align:start position:0% +President says you'll get it + + + align:start position:0% +President says you'll get it +so that's how close we + + align:start position:0% +so that's how close we + + + align:start position:0% +so that's how close we +were to the shuttle + + align:start position:0% +were to the shuttle + + + align:start position:0% +were to the shuttle +failing in a from a + + align:start position:0% +failing in a from a + + + align:start position:0% +failing in a from a +political point of + + align:start position:0% +political point of + + + align:start position:0% +political point of +view + + align:start position:0% +view + + + align:start position:0% +view +so I don't know what the politics of + + align:start position:0% +so I don't know what the politics of + + + align:start position:0% +so I don't know what the politics of +Tomorrow is that might change our mind + + align:start position:0% +Tomorrow is that might change our mind + + + align:start position:0% +Tomorrow is that might change our mind +it would be wonderful if the Chinese + + align:start position:0% +it would be wonderful if the Chinese + + + align:start position:0% +it would be wonderful if the Chinese +were laying on the moon + + align:start position:0% +were laying on the moon + + + align:start position:0% +were laying on the moon +tomorrow that might get the Congress + + align:start position:0% +tomorrow that might get the Congress + + + align:start position:0% +tomorrow that might get the Congress +back in + + align:start position:0% +back in + + + align:start position:0% +back in +action but I just can't see can you see + + align:start position:0% +action but I just can't see can you see + + + align:start position:0% +action but I just can't see can you see +the Congress + + align:start position:0% +the Congress + + + align:start position:0% +the Congress +in the face of what's happened to katri + + align:start position:0% +in the face of what's happened to katri + + + align:start position:0% +in the face of what's happened to katri +and Rita + + align:start position:0% +and Rita + + + align:start position:0% +and Rita +and and a few other things that happened + + align:start position:0% +and and a few other things that happened + + + align:start position:0% +and and a few other things that happened +in the United States and the Iraq Iraqi + + align:start position:0% +in the United States and the Iraq Iraqi + + + align:start position:0% +in the United States and the Iraq Iraqi +Iraqi War the budgetary problem they + + align:start position:0% +Iraqi War the budgetary problem they + + + align:start position:0% +Iraqi War the budgetary problem they +face I can't see them give a mass of the + + align:start position:0% +face I can't see them give a mass of the + + + align:start position:0% +face I can't see them give a mass of the +money they need to do the program and + + align:start position:0% +money they need to do the program and + + + align:start position:0% +money they need to do the program and +NASA says they can go back to the + + align:start position:0% +NASA says they can go back to the + + + align:start position:0% +NASA says they can go back to the +Moon uh between now and and N what is it + + align:start position:0% +Moon uh between now and and N what is it + + + align:start position:0% +Moon uh between now and and N what is it +2018 for 106 billion + + align:start position:0% +2018 for 106 billion + + + align:start position:0% +2018 for 106 billion +dollar you know + + align:start position:0% +dollar you know + + + align:start position:0% +dollar you know +Mr Webb doubled the price you know we + + align:start position:0% +Mr Webb doubled the price you know we + + + align:start position:0% +Mr Webb doubled the price you know we +all all us great cost estimators + + align:start position:0% +all all us great cost estimators + + + align:start position:0% +all all us great cost estimators +estimated the cost of the shuttle and + + align:start position:0% +estimated the cost of the shuttle and + + + align:start position:0% +estimated the cost of the shuttle and +Jim Web got it and multiplied it by + + align:start position:0% +Jim Web got it and multiplied it by + + + align:start position:0% +Jim Web got it and multiplied it by +two today I'd say you have to multiply + + align:start position:0% +two today I'd say you have to multiply + + + align:start position:0% +two today I'd say you have to multiply +that by + + align:start position:0% +that by + + + align:start position:0% +that by +10 if you think you going back to the + + align:start position:0% +10 if you think you going back to the + + + align:start position:0% +10 if you think you going back to the +moon and I can't + + align:start position:0% +moon and I can't + + + align:start position:0% +moon and I can't +imagine Aaron and I worked on a program + + align:start position:0% +imagine Aaron and I worked on a program + + + align:start position:0% +imagine Aaron and I worked on a program +in + + align:start position:0% +in + + + align:start position:0% +in +uh 19 what + + align:start position:0% +uh 19 what + + + align:start position:0% +uh 19 what + + align:start position:0% + + + align:start position:0% +98 when when did we do the lunar study + + align:start position:0% +98 when when did we do the lunar study + + + align:start position:0% +98 when when did we do the lunar study +going back going back to the I mean + + align:start position:0% +going back going back to the I mean + + + align:start position:0% +going back going back to the I mean +excuse me the Mars + + align:start position:0% +excuse me the Mars + + + align:start position:0% +excuse me the Mars +study 89 we estimated the cost of $1 + + align:start position:0% +study 89 we estimated the cost of $1 + + + align:start position:0% +study 89 we estimated the cost of $1 +1989 to go to Mars at400 billion + + align:start position:0% + + + + align:start position:0% + +dollar and I think we were + + align:start position:0% + + + + align:start position:0% + +low so I I know I have I keep have to + + align:start position:0% +low so I I know I have I keep have to + + + align:start position:0% +low so I I know I have I keep have to +catch myself I know it's a + + align:start position:0% +catch myself I know it's a + + + align:start position:0% +catch myself I know it's a +politics you have to be concerned about + + align:start position:0% +politics you have to be concerned about + + + align:start position:0% +politics you have to be concerned about +it you know if you told them that it was + + align:start position:0% +it you know if you told them that it was + + + align:start position:0% +it you know if you told them that it was +going to cost $400 billion then for sure + + align:start position:0% +going to cost $400 billion then for sure + + + align:start position:0% +going to cost $400 billion then for sure +it would be cancelled + + align:start position:0% +it would be cancelled + + + align:start position:0% +it would be cancelled +right but so you got to tell them + + align:start position:0% +right but so you got to tell them + + + align:start position:0% +right but so you got to tell them +something that's rational but I don't + + align:start position:0% +something that's rational but I don't + + + align:start position:0% +something that's rational but I don't +think they'll get supported even this + + align:start position:0% +think they'll get supported even this + + + align:start position:0% +think they'll get supported even this +even with the mount somebody they say + + align:start position:0% +even with the mount somebody they say + + + align:start position:0% +even with the mount somebody they say +it's what it cost I hope I am a + + align:start position:0% +it's what it cost I hope I am a + + + align:start position:0% +it's what it cost I hope I am a +pessimist just I have two separate + + align:start position:0% +pessimist just I have two separate + + + align:start position:0% +pessimist just I have two separate +questions uh one is I was wondering if + + align:start position:0% +questions uh one is I was wondering if + + + align:start position:0% +questions uh one is I was wondering if +with the improvements you said were made + + align:start position:0% +with the improvements you said were made + + + align:start position:0% +with the improvements you said were made +in uh in Computing capability from + + align:start position:0% +in uh in Computing capability from + + + align:start position:0% +in uh in Computing capability from +Mercury through uh the shuttle I was + + align:start position:0% +Mercury through uh the shuttle I was + + + align:start position:0% +Mercury through uh the shuttle I was +wondering if there was any thought into + + align:start position:0% +wondering if there was any thought into + + + align:start position:0% +wondering if there was any thought into +making the computer systems on the + + align:start position:0% +making the computer systems on the + + + align:start position:0% +making the computer systems on the +shuttle more upgradable and if it if it + + align:start position:0% +shuttle more upgradable and if it if it + + + align:start position:0% +shuttle more upgradable and if it if it +was would there have been any value + + align:start position:0% +was would there have been any value + + + align:start position:0% +was would there have been any value +using modern systems um and then the + + align:start position:0% +using modern systems um and then the + + + align:start position:0% +using modern systems um and then the +second question is related to the um the + + align:start position:0% +second question is related to the um the + + + align:start position:0% +second question is related to the um the +comment you made about if the uh if the + + align:start position:0% +comment you made about if the uh if the + + + align:start position:0% +comment you made about if the uh if the +shuttle is designed to fly automatically + + align:start position:0% +shuttle is designed to fly automatically + + + align:start position:0% +shuttle is designed to fly automatically +after the Challenger accident could just + + align:start position:0% +after the Challenger accident could just + + + align:start position:0% +after the Challenger accident could just +flown again the next day and I wasn't + + align:start position:0% +flown again the next day and I wasn't + + + align:start position:0% +flown again the next day and I wasn't +really sure what you Me by that so I was + + align:start position:0% +really sure what you Me by that so I was + + + align:start position:0% +really sure what you Me by that so I was +hoping you could elaborate on it a bit + + align:start position:0% +hoping you could elaborate on it a bit + + + align:start position:0% +hoping you could elaborate on it a bit +uh let me go to your first question uh + + align:start position:0% +uh let me go to your first question uh + + + align:start position:0% +uh let me go to your first question uh +it isn't a hardware it's a software and + + align:start position:0% +it isn't a hardware it's a software and + + + align:start position:0% +it isn't a hardware it's a software and +it's a software checkout and it's a + + align:start position:0% +it's a software checkout and it's a + + + align:start position:0% +it's a software checkout and it's a +software + + align:start position:0% +software + + + align:start position:0% +software +validation that you have to worry about + + align:start position:0% +validation that you have to worry about + + + align:start position:0% +validation that you have to worry about +on the on the Orbiter when you you have + + align:start position:0% +on the on the Orbiter when you you have + + + align:start position:0% +on the on the Orbiter when you you have +four systems that are operating on a 40 + + align:start position:0% +four systems that are operating on a 40 + + + align:start position:0% +four systems that are operating on a 40 +m second time cycle and checking with + + align:start position:0% +m second time cycle and checking with + + + align:start position:0% +m second time cycle and checking with +each + + align:start position:0% +each + + + align:start position:0% +each +other uh at the end of that cycle + + align:start position:0% +other uh at the end of that cycle + + + align:start position:0% +other uh at the end of that cycle +they're all in in lock + + align:start position:0% +they're all in in lock + + + align:start position:0% +they're all in in lock +step John is looking at me saying my God + + align:start position:0% +step John is looking at me saying my God + + + align:start position:0% +step John is looking at me saying my God +how did we ever do that and I don't know + + align:start position:0% +how did we ever do that and I don't know + + + align:start position:0% +how did we ever do that and I don't know +how we ever did it but we did it but + + align:start position:0% +how we ever did it but we did it but + + + align:start position:0% +how we ever did it but we did it but +that it's the software not the hardware + + align:start position:0% +that it's the software not the hardware + + + align:start position:0% +that it's the software not the hardware +so when you build a new replace have an + + align:start position:0% +so when you build a new replace have an + + + align:start position:0% +so when you build a new replace have an +update computer which you should have + + align:start position:0% +update computer which you should have + + + align:start position:0% +update computer which you should have +and will have it's the software that's + + align:start position:0% +and will have it's the software that's + + + align:start position:0% +and will have it's the software that's +the problem not the hardware always + + align:start position:0% +the problem not the hardware always + + + align:start position:0% +the problem not the hardware always +that's always been the + + align:start position:0% +that's always been the + + + align:start position:0% +that's always been the +case yeah trying to make trying to make + + align:start position:0% +case yeah trying to make trying to make + + + align:start position:0% +case yeah trying to make trying to make +the software fit into the new + + align:start position:0% +the software fit into the new + + + align:start position:0% +the software fit into the new +computer the way the hooks are in this + + align:start position:0% +computer the way the hooks are in this + + + align:start position:0% +computer the way the hooks are in this +system uh it's just totally different + + align:start position:0% +system uh it's just totally different + + + align:start position:0% +system uh it's just totally different +and therefore the + + align:start position:0% +and therefore the + + + align:start position:0% +and therefore the +guarantee that the system doesn't have a + + align:start position:0% +guarantee that the system doesn't have a + + + align:start position:0% +guarantee that the system doesn't have a +bunch of uh glitches in + + align:start position:0% +bunch of uh glitches in + + + align:start position:0% +bunch of uh glitches in +it uh that are going to get to you you + + align:start position:0% +it uh that are going to get to you you + + + align:start position:0% +it uh that are going to get to you you +know when we when we flew to the moon on + + align:start position:0% +know when we when we flew to the moon on + + + align:start position:0% +know when we when we flew to the moon on +Apollo 11 we had a book about that thick + + align:start position:0% +Apollo 11 we had a book about that thick + + + align:start position:0% +Apollo 11 we had a book about that thick +with computer anomalies in + + align:start position:0% +with computer anomalies in + + + align:start position:0% +with computer anomalies in +it we understood them all but that's how + + align:start position:0% +it we understood them all but that's how + + + align:start position:0% +it we understood them all but that's how +many software fixes we needed to make we + + align:start position:0% +many software fixes we needed to make we + + + align:start position:0% +many software fixes we needed to make we +just didn't make them because we didn't + + align:start position:0% +just didn't make them because we didn't + + + align:start position:0% +just didn't make them because we didn't +want to or nor have the time to do + + align:start position:0% +want to or nor have the time to do + + + align:start position:0% +want to or nor have the time to do +it uh what I meant by flying the uh an + + align:start position:0% +it uh what I meant by flying the uh an + + + align:start position:0% +it uh what I meant by flying the uh an +unmanned shuttle was that you couldn't + + align:start position:0% +unmanned shuttle was that you couldn't + + + align:start position:0% +unmanned shuttle was that you couldn't +convince the politicians + + align:start position:0% +convince the politicians + + + align:start position:0% +convince the politicians +or the poers that be whoever they are + + align:start position:0% +or the poers that be whoever they are + + + align:start position:0% +or the poers that be whoever they are +that you could fly the shuttle the next + + align:start position:0% +that you could fly the shuttle the next + + + align:start position:0% +that you could fly the shuttle the next +day un a man but if you didn't have a + + align:start position:0% +day un a man but if you didn't have a + + + align:start position:0% +day un a man but if you didn't have a +man in it who would have cared and so + + align:start position:0% +man in it who would have cared and so + + + align:start position:0% +man in it who would have cared and so +you could have flown it the next day and + + align:start position:0% +you could have flown it the next day and + + + align:start position:0% +you could have flown it the next day and +it would have worked perfectly because + + align:start position:0% +it would have worked perfectly because + + + align:start position:0% +it would have worked perfectly because +it was warmer at the + + align:start position:0% +it was warmer at the + + + align:start position:0% +it was warmer at the +cake you know do you know what the + + align:start position:0% +cake you know do you know what the + + + align:start position:0% +cake you know do you know what the +condition on the pad was the morning + + align:start position:0% +condition on the pad was the morning + + + align:start position:0% +condition on the pad was the morning +they launched + + align:start position:0% + + + + align:start position:0% + +challenger no there were icicles hanging + + align:start position:0% +challenger no there were icicles hanging + + + align:start position:0% +challenger no there were icicles hanging +off the Gantry that + + align:start position:0% +off the Gantry that + + + align:start position:0% +off the Gantry that +long and that big + + align:start position:0% +long and that big + + + align:start position:0% +long and that big +around at Cape + + align:start position:0% +around at Cape + + + align:start position:0% +around at Cape +canabra let me tell you something they + + align:start position:0% +canabra let me tell you something they + + + align:start position:0% +canabra let me tell you something they +did you know why they got there they did + + align:start position:0% +did you know why they got there they did + + + align:start position:0% +did you know why they got there they did +what we did in + + align:start position:0% +what we did in + + + align:start position:0% +what we did in +1920 turn the water on let it run all + + align:start position:0% +1920 turn the water on let it run all + + + align:start position:0% +1920 turn the water on let it run all +night because they were afraid that the + + align:start position:0% +night because they were afraid that the + + + align:start position:0% +night because they were afraid that the +the uh fire suppression system on the + + align:start position:0% +the uh fire suppression system on the + + + align:start position:0% +the uh fire suppression system on the +pad was going to + + align:start position:0% +pad was going to + + + align:start position:0% +pad was going to +freeze and not be able to be turned on + + align:start position:0% +freeze and not be able to be turned on + + + align:start position:0% +freeze and not be able to be turned on +when they launched so they let it drip + + align:start position:0% +when they launched so they let it drip + + + align:start position:0% +when they launched so they let it drip +all + + align:start position:0% + + + + align:start position:0% + +night and I'm sitting there saying that + + align:start position:0% +night and I'm sitting there saying that + + + align:start position:0% +night and I'm sitting there saying that +solid rocket has not been qualif for + + align:start position:0% +solid rocket has not been qualif for + + + align:start position:0% +solid rocket has not been qualif for +temperatures below 47 degrees + + align:start position:0% + + + + align:start position:0% + +F and they're convincing themselves that + + align:start position:0% +F and they're convincing themselves that + + + align:start position:0% +F and they're convincing themselves that +the core temperature of the + + align:start position:0% +the core temperature of the + + + align:start position:0% +the core temperature of the +solids is much higher than that because + + align:start position:0% +solids is much higher than that because + + + align:start position:0% +solids is much higher than that because +it's been sitting in the sun for the + + align:start position:0% +it's been sitting in the sun for the + + + align:start position:0% +it's been sitting in the sun for the +last two months and the temperature is + + align:start position:0% +last two months and the temperature is + + + align:start position:0% +last two months and the temperature is +so and so but they didn't think about + + align:start position:0% +so and so but they didn't think about + + + align:start position:0% +so and so but they didn't think about +the + + align:start position:0% + + + + align:start position:0% + +seals you remember that Professor + + align:start position:0% +seals you remember that Professor + + + align:start position:0% +seals you remember that Professor +sticking a seal in the ice + + align:start position:0% + + + + align:start position:0% + +that's what I meant by you could the + + align:start position:0% +that's what I meant by you could the + + + align:start position:0% +that's what I meant by you could the +next day the temperature would have been + + align:start position:0% +next day the temperature would have been + + + align:start position:0% +next day the temperature would have been +warmer new rockets on Max F said the + + align:start position:0% +warmer new rockets on Max F said the + + + align:start position:0% +warmer new rockets on Max F said the +next day why don't you just put a belly + + align:start position:0% +next day why don't you just put a belly + + + align:start position:0% +next day why don't you just put a belly +band and a heater put a heater around + + align:start position:0% +band and a heater put a heater around + + + align:start position:0% +band and a heater put a heater around +the joint and put a belly band over top + + align:start position:0% +the joint and put a belly band over top + + + align:start position:0% +the joint and put a belly band over top +of it and + + align:start position:0% +of it and + + + align:start position:0% +of it and +fly damn good + + align:start position:0% + + + + align:start position:0% + +idea yes + + align:start position:0% +idea yes + + + align:start position:0% +idea yes +sir uh you mentioned that the one of the + + align:start position:0% +sir uh you mentioned that the one of the + + + align:start position:0% +sir uh you mentioned that the one of the +reasons the shuttle is so expensive + + align:start position:0% +reasons the shuttle is so expensive + + + align:start position:0% +reasons the shuttle is so expensive +because you have many redundant systems + + align:start position:0% +because you have many redundant systems + + + align:start position:0% +because you have many redundant systems +on board now what what would be your + + align:start position:0% +on board now what what would be your + + + align:start position:0% +on board now what what would be your +solution not to have them on board or + + align:start position:0% +solution not to have them on board or + + + align:start position:0% +solution not to have them on board or +just to uh not to have them all + + align:start position:0% +just to uh not to have them all + + + align:start position:0% +just to uh not to have them all +operating at launch no you got the wrong + + align:start position:0% +operating at launch no you got the wrong + + + align:start position:0% +operating at launch no you got the wrong +you got the wrong implication there it's + + align:start position:0% +you got the wrong implication there it's + + + align:start position:0% +you got the wrong implication there it's +expensive because they insist on having + + align:start position:0% +expensive because they insist on having + + + align:start position:0% +expensive because they insist on having +them operating at the time of launch + + align:start position:0% +them operating at the time of launch + + + align:start position:0% +them operating at the time of launch +it's not the + + align:start position:0% +it's not the + + + align:start position:0% +it's not the +redundancy that makes it more expensive + + align:start position:0% +redundancy that makes it more expensive + + + align:start position:0% +redundancy that makes it more expensive +it's the check out and the testing the + + align:start position:0% +it's the check out and the testing the + + + align:start position:0% +it's the check out and the testing the +proof that it's there and the + + align:start position:0% +proof that it's there and the + + + align:start position:0% +proof that it's there and the +replacement of the system + + align:start position:0% +replacement of the system + + + align:start position:0% +replacement of the system +and the use of the system that makes it + + align:start position:0% +and the use of the system that makes it + + + align:start position:0% +and the use of the system that makes it +more expensive but what makes the + + align:start position:0% +more expensive but what makes the + + + align:start position:0% +more expensive but what makes the +shuttle so expensive is the numbers of + + align:start position:0% +shuttle so expensive is the numbers of + + + align:start position:0% +shuttle so expensive is the numbers of +people involved in preparing + + align:start position:0% +people involved in preparing + + + align:start position:0% +people involved in preparing +it there are roughly 10,000 people + + align:start position:0% +it there are roughly 10,000 people + + + align:start position:0% +it there are roughly 10,000 people +involved in that + + align:start position:0% +involved in that + + + align:start position:0% +involved in that +operation who make X number of dollars + + align:start position:0% +operation who make X number of dollars + + + align:start position:0% +operation who make X number of dollars +per hour or day and cost it cost in + + align:start position:0% +per hour or day and cost it cost in + + + align:start position:0% +per hour or day and cost it cost in +today's money about + + align:start position:0% +today's money about + + + align:start position:0% +today's money about +a year to fly the shuttle seven + + align:start position:0% +a year to fly the shuttle seven + + + align:start position:0% +a year to fly the shuttle seven +times probably cost5 billion a year to + + align:start position:0% +times probably cost5 billion a year to + + + align:start position:0% +times probably cost5 billion a year to +fly 30 times not much different maybe + + align:start position:0% +fly 30 times not much different maybe + + + align:start position:0% +fly 30 times not much different maybe +5.5 million so it's the people you got + + align:start position:0% +5.5 million so it's the people you got + + + align:start position:0% +5.5 million so it's the people you got +to get rid of the people and that's + + align:start position:0% +to get rid of the people and that's + + + align:start position:0% +to get rid of the people and that's +that's what people have been trying to + + align:start position:0% +that's what people have been trying to + + + align:start position:0% +that's what people have been trying to +do that ever since + + align:start position:0% +do that ever since + + + align:start position:0% +do that ever since +Mercury get rid of the amount of people + + align:start position:0% +Mercury get rid of the amount of people + + + align:start position:0% +Mercury get rid of the amount of people +and they they try and they put in the + + align:start position:0% +and they they try and they put in the + + + align:start position:0% +and they they try and they put in the +automaticity and the automatic check + + align:start position:0% +automaticity and the automatic check + + + align:start position:0% +automaticity and the automatic check +out and then don't use + + align:start position:0% +out and then don't use + + + align:start position:0% +out and then don't use +it check it you know as I said they put + + align:start position:0% +it check it you know as I said they put + + + align:start position:0% +it check it you know as I said they put +more hours on it in the hanger than they + + align:start position:0% +more hours on it in the hanger than they + + + align:start position:0% +more hours on it in the hanger than they +do in + + align:start position:0% +do in + + + align:start position:0% +do in +space where at the system check of you + + align:start position:0% +space where at the system check of you + + + align:start position:0% +space where at the system check of you +and it takes people to do + + align:start position:0% +and it takes people to do + + + align:start position:0% +and it takes people to do +that so it's + + align:start position:0% + + + + align:start position:0% + +people uh I think you have to have some + + align:start position:0% +people uh I think you have to have some + + + align:start position:0% +people uh I think you have to have some +hard-nosed + + align:start position:0% +hard-nosed + + + align:start position:0% +hard-nosed +SOB that says I'm GNA get rid of the + + align:start position:0% +SOB that says I'm GNA get rid of the + + + align:start position:0% +SOB that says I'm GNA get rid of the +people and you do it with + + align:start position:0% +people and you do it with + + + align:start position:0% +people and you do it with +automaticity automatic checkup automatic + + align:start position:0% +automaticity automatic checkup automatic + + + align:start position:0% +automaticity automatic checkup automatic +everything in today's world why would + + align:start position:0% +everything in today's world why would + + + align:start position:0% +everything in today's world why would +you do it any other way give you another + + align:start position:0% +you do it any other way give you another + + + align:start position:0% +you do it any other way give you another +example when we built the caution and + + align:start position:0% +example when we built the caution and + + + align:start position:0% +example when we built the caution and +warning + + align:start position:0% +warning + + + align:start position:0% +warning +system on the space + + align:start position:0% +system on the space + + + align:start position:0% +system on the space +shuttle this the uh safety and + + align:start position:0% +shuttle this the uh safety and + + + align:start position:0% +shuttle this the uh safety and +reliability people said it has to be + + align:start position:0% +reliability people said it has to be + + + align:start position:0% +reliability people said it has to be +hardwired can you imagine + + align:start position:0% +hardwired can you imagine + + + align:start position:0% +hardwired can you imagine +that why would use + + align:start position:0% +that why would use + + + align:start position:0% +that why would use +bits instead of hard wire oh but it's a + + align:start position:0% +bits instead of hard wire oh but it's a + + + align:start position:0% +bits instead of hard wire oh but it's a +lot safer lot + + align:start position:0% +lot safer lot + + + align:start position:0% +lot safer lot +reliable use my same word hogwash it's a + + align:start position:0% +reliable use my same word hogwash it's a + + + align:start position:0% +reliable use my same word hogwash it's a +lot safer and more reliable with + + align:start position:0% +lot safer and more reliable with + + + align:start position:0% +lot safer and more reliable with +bits but that's the + + align:start position:0% +bits but that's the + + + align:start position:0% +bits but that's the +system you got to change + + align:start position:0% + + + + align:start position:0% + +it + + align:start position:0% +it + + + align:start position:0% +it +and two of us have tried see us flying + + align:start position:0% +and two of us have tried see us flying + + + align:start position:0% +and two of us have tried see us flying +down in flames almost + + align:start position:0% + + + + align:start position:0% + +everywhere yes + + align:start position:0% +everywhere yes + + + align:start position:0% +everywhere yes +sir as young here a lot of us you know + + align:start position:0% +sir as young here a lot of us you know + + + align:start position:0% +sir as young here a lot of us you know +hear all about the AP and a lot of us + + align:start position:0% +hear all about the AP and a lot of us + + + align:start position:0% +hear all about the AP and a lot of us +even talk about the old good old days + + align:start position:0% +even talk about the old good old days + + + align:start position:0% +even talk about the old good old days +where you know we wish we were live in + + align:start position:0% +where you know we wish we were live in + + + align:start position:0% +where you know we wish we were live in +the days of you know engineering by the + + align:start position:0% +the days of you know engineering by the + + + align:start position:0% +the days of you know engineering by the +your pants is is that type of job and + + align:start position:0% +your pants is is that type of job and + + + align:start position:0% +your pants is is that type of job and +that type of excitement of an + + align:start position:0% +that type of excitement of an + + + align:start position:0% +that type of excitement of an +engineering possible in N environment + + align:start position:0% +engineering possible in N environment + + + align:start position:0% +engineering possible in N environment +today or should we look elsewhere like + + align:start position:0% +today or should we look elsewhere like + + + align:start position:0% +today or should we look elsewhere like +towards private Enterprises or or can we + + align:start position:0% +towards private Enterprises or or can we + + + align:start position:0% +towards private Enterprises or or can we +find the type of job we hear about + + align:start position:0% +find the type of job we hear about + + + align:start position:0% +find the type of job we hear about +holidays in NASA these + + align:start position:0% + + + + align:start position:0% + +days have to be careful how I answer + + align:start position:0% +days have to be careful how I answer + + + align:start position:0% +days have to be careful how I answer +that I want you in NASA + + align:start position:0% + + + + align:start position:0% + +uh it's important that you guys be a + + align:start position:0% +uh it's important that you guys be a + + + align:start position:0% +uh it's important that you guys be a +Daner or at least in the space program + + align:start position:0% +Daner or at least in the space program + + + align:start position:0% +Daner or at least in the space program +working in the industry because you are + + align:start position:0% +working in the industry because you are + + + align:start position:0% +working in the industry because you are +tomorrow's + + align:start position:0% +tomorrow's + + + align:start position:0% +tomorrow's +opportunity you don't want to do just + + align:start position:0% +opportunity you don't want to do just + + + align:start position:0% +opportunity you don't want to do just +because you hear Chris CRA say things + + align:start position:0% +because you hear Chris CRA say things + + + align:start position:0% +because you hear Chris CRA say things +that doesn't mean a damn thing tomorrow + + align:start position:0% +that doesn't mean a damn thing tomorrow + + + align:start position:0% +that doesn't mean a damn thing tomorrow +you have to do it yourself and you have + + align:start position:0% +you have to do it yourself and you have + + + align:start position:0% +you have to do it yourself and you have +to want to do it yourself and you have + + align:start position:0% +to want to do it yourself and you have + + + align:start position:0% +to want to do it yourself and you have +to bring the IDE + + align:start position:0% +to bring the IDE + + + align:start position:0% +to bring the IDE +is to the program and you have to be + + align:start position:0% +is to the program and you have to be + + + align:start position:0% +is to the program and you have to be +willing to do that and it's a + + align:start position:0% +willing to do that and it's a + + + align:start position:0% +willing to do that and it's a +willingness to take on the the things + + align:start position:0% +willingness to take on the the things + + + align:start position:0% +willingness to take on the the things +that must be taken on in order to get + + align:start position:0% +that must be taken on in order to get + + + align:start position:0% +that must be taken on in order to get +the job + + align:start position:0% +the job + + + align:start position:0% +the job +done so your question about seed of the + + align:start position:0% +done so your question about seed of the + + + align:start position:0% +done so your question about seed of the +pants Etc sure we did a lot of things + + align:start position:0% +pants Etc sure we did a lot of things + + + align:start position:0% +pants Etc sure we did a lot of things +when we first started by seed of the + + align:start position:0% +when we first started by seed of the + + + align:start position:0% +when we first started by seed of the +pants because we didn't + + align:start position:0% +pants because we didn't + + + align:start position:0% +pants because we didn't +know any other way to do it we had to we + + align:start position:0% +know any other way to do it we had to we + + + align:start position:0% +know any other way to do it we had to we +did it by fi we did it by last + + align:start position:0% +did it by fi we did it by last + + + align:start position:0% +did it by fi we did it by last +experience most of us had been in the + + align:start position:0% +experience most of us had been in the + + + align:start position:0% +experience most of us had been in the +not a lot of us had been in the flight + + align:start position:0% +not a lot of us had been in the flight + + + align:start position:0% +not a lot of us had been in the flight +test World airplane flight test world so + + align:start position:0% +test World airplane flight test world so + + + align:start position:0% +test World airplane flight test world so +we did it by having seen the past having + + align:start position:0% +we did it by having seen the past having + + + align:start position:0% +we did it by having seen the past having +doing things the right way that was our + + align:start position:0% +doing things the right way that was our + + + align:start position:0% +doing things the right way that was our +seat of the pants so our seat of the + + align:start position:0% +seat of the pants so our seat of the + + + align:start position:0% +seat of the pants so our seat of the +pants wasn't just a scarf around our + + align:start position:0% +pants wasn't just a scarf around our + + + align:start position:0% +pants wasn't just a scarf around our +neck so to + + align:start position:0% +neck so to + + + align:start position:0% +neck so to +speak it was done it was an educated + + align:start position:0% +speak it was done it was an educated + + + align:start position:0% +speak it was done it was an educated +seat of the pants and that's what you + + align:start position:0% +seat of the pants and that's what you + + + align:start position:0% +seat of the pants and that's what you +have to + + align:start position:0% +have to + + + align:start position:0% +have to +in the end it will take a lot of the + + align:start position:0% +in the end it will take a lot of the + + + align:start position:0% +in the end it will take a lot of the +seed of the + + align:start position:0% + + + + align:start position:0% + +pains I think the + + align:start position:0% +pains I think the + + + align:start position:0% +pains I think the +way I know Aon and I have done it was + + align:start position:0% +way I know Aon and I have done it was + + + align:start position:0% +way I know Aon and I have done it was +to believe in the people you have you + + align:start position:0% +to believe in the people you have you + + + align:start position:0% +to believe in the people you have you +have to learn how to find out who the + + align:start position:0% +have to learn how to find out who the + + + align:start position:0% +have to learn how to find out who the +guys that are that know what they're + + align:start position:0% +guys that are that know what they're + + + align:start position:0% +guys that are that know what they're +talking about and trust them have put + + align:start position:0% +talking about and trust them have put + + + align:start position:0% +talking about and trust them have put +them in the job give them responsibility + + align:start position:0% +them in the job give them responsibility + + + align:start position:0% +them in the job give them responsibility +and authority to do it and then trust + + align:start position:0% +and authority to do it and then trust + + + align:start position:0% +and authority to do it and then trust +them + + align:start position:0% +them + + + align:start position:0% +them +and you have to build + + align:start position:0% +and you have to build + + + align:start position:0% +and you have to build +them that the biggest problem that you + + align:start position:0% +them that the biggest problem that you + + + align:start position:0% +them that the biggest problem that you +have today that NASA has today and the + + align:start position:0% +have today that NASA has today and the + + + align:start position:0% +have today that NASA has today and the +Aerospace industry has today biggest + + align:start position:0% +Aerospace industry has today biggest + + + align:start position:0% +Aerospace industry has today biggest +problem can't say that too strong is + + align:start position:0% +problem can't say that too strong is + + + align:start position:0% +problem can't say that too strong is +that they have not built anything in 25 + + align:start position:0% +that they have not built anything in 25 + + + align:start position:0% +that they have not built anything in 25 +years and so they've forgotten what it + + align:start position:0% +years and so they've forgotten what it + + + align:start position:0% +years and so they've forgotten what it +takes to do + + align:start position:0% +takes to do + + + align:start position:0% +takes to do +it you don't know how to do it but if I + + align:start position:0% +it you don't know how to do it but if I + + + align:start position:0% +it you don't know how to do it but if I +put you on the job and put you in the + + align:start position:0% +put you on the job and put you in the + + + align:start position:0% +put you on the job and put you in the +give you the authority to do it you + + align:start position:0% +give you the authority to do it you + + + align:start position:0% +give you the authority to do it you +could do it in three or four years you + + align:start position:0% +could do it in three or four years you + + + align:start position:0% +could do it in three or four years you +need my help and guys like me to tell + + align:start position:0% +need my help and guys like me to tell + + + align:start position:0% +need my help and guys like me to tell +you where the bumps in the road + + align:start position:0% +you where the bumps in the road + + + align:start position:0% +you where the bumps in the road +are but you're going to do it a hell of + + align:start position:0% +are but you're going to do it a hell of + + + align:start position:0% +are but you're going to do it a hell of +a lot better than I + + align:start position:0% +a lot better than I + + + align:start position:0% +a lot better than I +did given the opportunity to do + + align:start position:0% +did given the opportunity to do + + + align:start position:0% +did given the opportunity to do +it that answer your + + align:start position:0% + + + + align:start position:0% + +question I + + align:start position:0% +question I + + + align:start position:0% +question I +you might have to help + + align:start position:0% +you might have to help + + + align:start position:0% +you might have to help +it you have to + + align:start position:0% + + + + align:start position:0% + +vote I say that only I was hoping when I + + align:start position:0% +vote I say that only I was hoping when I + + + align:start position:0% +vote I say that only I was hoping when I +in the 60s I was hoping that all these + + align:start position:0% +in the 60s I was hoping that all these + + + align:start position:0% +in the 60s I was hoping that all these +Space Cadets all these trekkies all + + align:start position:0% +Space Cadets all these trekkies all + + + align:start position:0% +Space Cadets all these trekkies all +those guys would now be in the + + align:start position:0% + + + + align:start position:0% + +Congress and and that they would vote + + align:start position:0% +Congress and and that they would vote + + + align:start position:0% +Congress and and that they would vote +for the Space Program boy was I ever + + align:start position:0% +for the Space Program boy was I ever + + + align:start position:0% +for the Space Program boy was I ever +dead wrong + + align:start position:0% +dead wrong + + + align:start position:0% +dead wrong +you know uh there aren't enough Grateful + + align:start position:0% +you know uh there aren't enough Grateful + + + align:start position:0% +you know uh there aren't enough Grateful +Dead fans + + align:start position:0% + + + + align:start position:0% + +around yes sir think sucess of the was + + align:start position:0% +around yes sir think sucess of the was + + + align:start position:0% +around yes sir think sucess of the was +in some way link to the F that was + + align:start position:0% +in some way link to the F that was + + + align:start position:0% +in some way link to the F that was +taking place in the + + align:start position:0% +taking place in the + + + align:start position:0% +taking place in the +60s oh + + align:start position:0% +60s oh + + + align:start position:0% +60s oh +absolutely I think that + + align:start position:0% +absolutely I think that + + + align:start position:0% +absolutely I think that +uh Lord you know we had an + + align:start position:0% +uh Lord you know we had an + + + align:start position:0% +uh Lord you know we had an +enthusiasm at the + + align:start position:0% +enthusiasm at the + + + align:start position:0% +enthusiasm at the +time that is is probably + + align:start position:0% +time that is is probably + + + align:start position:0% +time that is is probably +unparalleled in + + align:start position:0% +unparalleled in + + + align:start position:0% +unparalleled in +engineering circles now we had the + + align:start position:0% +engineering circles now we had the + + + align:start position:0% +engineering circles now we had the +Manhattan Project to build a nuclear + + align:start position:0% +Manhattan Project to build a nuclear + + + align:start position:0% +Manhattan Project to build a nuclear +bomb uh Draper had the project to build + + align:start position:0% +bomb uh Draper had the project to build + + + align:start position:0% +bomb uh Draper had the project to build +a PO submarine but it was it was close + + align:start position:0% +a PO submarine but it was it was close + + + align:start position:0% +a PO submarine but it was it was close +clustered clustered what is that + + align:start position:0% +clustered clustered what is that + + + align:start position:0% +clustered clustered what is that +word yeah and and + + align:start position:0% +word yeah and and + + + align:start position:0% +word yeah and and +uh it wasn't it wasn't seen as we + + align:start position:0% +uh it wasn't it wasn't seen as we + + + align:start position:0% +uh it wasn't it wasn't seen as we +brought it to the four it wasn't a + + align:start position:0% +brought it to the four it wasn't a + + + align:start position:0% +brought it to the four it wasn't a +national program it wasn't National + + align:start position:0% +national program it wasn't National + + + align:start position:0% +national program it wasn't National +priority it wasn't national pride those + + align:start position:0% +priority it wasn't national pride those + + + align:start position:0% +priority it wasn't national pride those +you know that nobody knew about it + + align:start position:0% +you know that nobody knew about it + + + align:start position:0% +you know that nobody knew about it +everybody knew about + + align:start position:0% +everybody knew about + + + align:start position:0% +everybody knew about +Apollo you know I was damn proud to walk + + align:start position:0% +Apollo you know I was damn proud to walk + + + align:start position:0% +Apollo you know I was damn proud to walk +into any room where I ever + + align:start position:0% +into any room where I ever + + + align:start position:0% +into any room where I ever +went to say I want worked on + + align:start position:0% + + + + align:start position:0% + +Apollo you know God that reminds me of a + + align:start position:0% +Apollo you know God that reminds me of a + + + align:start position:0% +Apollo you know God that reminds me of a +horrible to make my point uh reminds me + + align:start position:0% +horrible to make my point uh reminds me + + + align:start position:0% +horrible to make my point uh reminds me +of a horrible cartoon I was in Austin is + + align:start position:0% +of a horrible cartoon I was in Austin is + + + align:start position:0% +of a horrible cartoon I was in Austin is +about well following the Challenger + + align:start position:0% +about well following the Challenger + + + align:start position:0% +about well following the Challenger +accident and here I am one of the + + align:start position:0% +accident and here I am one of the + + + align:start position:0% +accident and here I am one of the +proudest people ever be in + + align:start position:0% +proudest people ever be in + + + align:start position:0% +proudest people ever be in +NASA the cartoon in the paper where I + + align:start position:0% +NASA the cartoon in the paper where I + + + align:start position:0% +NASA the cartoon in the paper where I +got up that morning was the + + align:start position:0% +got up that morning was the + + + align:start position:0% +got up that morning was the +following showed these kids playing with + + align:start position:0% +following showed these kids playing with + + + align:start position:0% +following showed these kids playing with +a what's the circle + + align:start position:0% +a what's the circle + + + align:start position:0% +a what's the circle +thing frisbee two kids playing with a + + align:start position:0% +thing frisbee two kids playing with a + + + align:start position:0% +thing frisbee two kids playing with a +frisbee first one he throws it over here + + align:start position:0% +frisbee first one he throws it over here + + + align:start position:0% +frisbee first one he throws it over here +this guy second second one he throws it + + align:start position:0% +this guy second second one he throws it + + + align:start position:0% +this guy second second one he throws it +back third one the damn thing explodes + + align:start position:0% +back third one the damn thing explodes + + + align:start position:0% +back third one the damn thing explodes +in his + + align:start position:0% +in his + + + align:start position:0% +in his +face fourth one says his father works + + align:start position:0% +face fourth one says his father works + + + align:start position:0% +face fourth one says his father works +for + + align:start position:0% + + + + align:start position:0% + +NASA well that brings it home to you + + align:start position:0% +NASA well that brings it home to you + + + align:start position:0% +NASA well that brings it home to you +pretty damn fast doesn't + + align:start position:0% +pretty damn fast doesn't + + + align:start position:0% +pretty damn fast doesn't +it nobody would nobody in in + + align:start position:0% +it nobody would nobody in in + + + align:start position:0% +it nobody would nobody in in +1967 68 69 nobody would have dared put + + align:start position:0% +1967 68 69 nobody would have dared put + + + align:start position:0% +1967 68 69 nobody would have dared put +that cartoon in the paper + + align:start position:0% + + + + align:start position:0% + +by having new people in a space program + + align:start position:0% +by having new people in a space program + + + align:start position:0% +by having new people in a space program +there's always this lack of experience + + align:start position:0% +there's always this lack of experience + + + align:start position:0% +there's always this lack of experience +which you have to trade just to have how + + align:start position:0% +which you have to trade just to have how + + + align:start position:0% +which you have to trade just to have how +do you transmit that + + align:start position:0% +do you transmit that + + + align:start position:0% +do you transmit that +experience to new people you intermingle + + align:start position:0% +experience to new people you intermingle + + + align:start position:0% +experience to new people you intermingle +you intermingle the young with the + + align:start position:0% +you intermingle the young with the + + + align:start position:0% +you intermingle the young with the +old you bring you bring the uh elderly + + align:start position:0% +old you bring you bring the uh elderly + + + align:start position:0% +old you bring you bring the uh elderly +Engineers into the + + align:start position:0% +Engineers into the + + + align:start position:0% +Engineers into the +system and make you responsible for + + align:start position:0% +system and make you responsible for + + + align:start position:0% +system and make you responsible for +Designing the system but have me your + + align:start position:0% +Designing the system but have me your + + + align:start position:0% +Designing the system but have me your +hip + + align:start position:0% +hip + + + align:start position:0% +hip +pocket but after six months after two + + align:start position:0% +pocket but after six months after two + + + align:start position:0% +pocket but after six months after two +years you don't need me in your hip + + align:start position:0% +years you don't need me in your hip + + + align:start position:0% +years you don't need me in your hip +pocket + + align:start position:0% +pocket + + + align:start position:0% +pocket +anymore because you would have learned + + align:start position:0% +anymore because you would have learned + + + align:start position:0% +anymore because you would have learned +all those things and learned them better + + align:start position:0% +all those things and learned them better + + + align:start position:0% +all those things and learned them better +and done them + + align:start position:0% +and done them + + + align:start position:0% +and done them +better so you have to mix + + align:start position:0% +better so you have to mix + + + align:start position:0% +better so you have to mix +the you know the ingredients for the pie + + align:start position:0% +the you know the ingredients for the pie + + + align:start position:0% +the you know the ingredients for the pie +and the cake have to be there and that's + + align:start position:0% +and the cake have to be there and that's + + + align:start position:0% +and the cake have to be there and that's +part of the + + align:start position:0% +part of the + + + align:start position:0% +part of the +ingredient and that's what why hasn't + + align:start position:0% +ingredient and that's what why hasn't + + + align:start position:0% +ingredient and that's what why hasn't +that taken place because two reasons + + align:start position:0% +that taken place because two reasons + + + align:start position:0% +that taken place because two reasons +uh NASA hasn't done anything in terms of + + align:start position:0% +uh NASA hasn't done anything in terms of + + + align:start position:0% +uh NASA hasn't done anything in terms of +building new hardware other than the + + align:start position:0% +building new hardware other than the + + + align:start position:0% +building new hardware other than the +space station which is really not wasn't + + align:start position:0% +space station which is really not wasn't + + + align:start position:0% +space station which is really not wasn't +testing the state-ofthe-art it was a + + align:start position:0% +testing the state-ofthe-art it was a + + + align:start position:0% +testing the state-ofthe-art it was a +great program it didn't test the State + + align:start position:0% +great program it didn't test the State + + + align:start position:0% +great program it didn't test the State +ofthe art but the + + align:start position:0% +ofthe art but the + + + align:start position:0% +ofthe art but the +industry has been doing the same thing + + align:start position:0% +industry has been doing the same thing + + + align:start position:0% +industry has been doing the same thing +the industry has been building airplanes + + align:start position:0% +the industry has been building airplanes + + + align:start position:0% +the industry has been building airplanes +but they haven't been building any + + align:start position:0% +but they haven't been building any + + + align:start position:0% +but they haven't been building any +spaceships so they've lost that + + align:start position:0% +spaceships so they've lost that + + + align:start position:0% +spaceships so they've lost that +capability also that's the travesty too + + align:start position:0% +capability also that's the travesty too + + + align:start position:0% +capability also that's the travesty too +you got to rebuild them both at the same + + align:start position:0% +you got to rebuild them both at the same + + + align:start position:0% +you got to rebuild them both at the same +time + + align:start position:0% +time + + + align:start position:0% +time +but it only happens by + + align:start position:0% +but it only happens by + + + align:start position:0% +but it only happens by +experience I can't take what Mr + + align:start position:0% +experience I can't take what Mr + + + align:start position:0% +experience I can't take what Mr +Professor Coen I knows or what I know + + align:start position:0% +Professor Coen I knows or what I know + + + align:start position:0% +Professor Coen I knows or what I know +and put it in your + + align:start position:0% +and put it in your + + + align:start position:0% +and put it in your +head you have to you have to + + align:start position:0% +head you have to you have to + + + align:start position:0% +head you have to you have to +fail a few times it's only by the + + align:start position:0% +fail a few times it's only by the + + + align:start position:0% +fail a few times it's only by the +failures that you're going to + + align:start position:0% + + + + align:start position:0% + +learn you know I once heard a sermon + + align:start position:0% +learn you know I once heard a sermon + + + align:start position:0% +learn you know I once heard a sermon +that + + align:start position:0% +that + + + align:start position:0% +that +said um when you're a young Christian or + + align:start position:0% +said um when you're a young Christian or + + + align:start position:0% +said um when you're a young Christian or +Hebrew walking down the the aisle all + + align:start position:0% +Hebrew walking down the the aisle all + + + align:start position:0% +Hebrew walking down the the aisle all +the doors are + + align:start position:0% +the doors are + + + align:start position:0% +the doors are +open your doors are all open I'm walking + + align:start position:0% +open your doors are all open I'm walking + + + align:start position:0% +open your doors are all open I'm walking +down the aisle and I'm pretty close to + + align:start position:0% +down the aisle and I'm pretty close to + + + align:start position:0% +down the aisle and I'm pretty close to +the end and they're all the ones behind + + align:start position:0% +the end and they're all the ones behind + + + align:start position:0% +the end and they're all the ones behind +me are + + align:start position:0% + + + + align:start position:0% + +shut you're willing + + align:start position:0% +shut you're willing + + + align:start position:0% +shut you're willing +to go into all those doors I'm + + align:start position:0% +to go into all those doors I'm + + + align:start position:0% +to go into all those doors I'm +frightened to death to go in those damn + + align:start position:0% +frightened to death to go in those damn + + + align:start position:0% +frightened to death to go in those damn +doors so we need need you and you need + + align:start position:0% +doors so we need need you and you need + + + align:start position:0% +doors so we need need you and you need +me but you don't need me very long till + + align:start position:0% +me but you don't need me very long till + + + align:start position:0% +me but you don't need me very long till +you get up to speed so don't be + + align:start position:0% +you get up to speed so don't be + + + align:start position:0% +you get up to speed so don't be +frightened of it go do it and don't be + + align:start position:0% +frightened of it go do it and don't be + + + align:start position:0% +frightened of it go do it and don't be +afraid to + + align:start position:0% +afraid to + + + align:start position:0% +afraid to +fail we learn much more from our + + align:start position:0% +fail we learn much more from our + + + align:start position:0% +fail we learn much more from our +failures than we ever learn from our + + align:start position:0% + + + + align:start position:0% + +successes back + + align:start position:0% +successes back + + + align:start position:0% +successes back +there've seen over the you thinkal + + align:start position:0% +there've seen over the you thinkal + + + align:start position:0% +there've seen over the you thinkal +access SP not necessarily going now but + + align:start position:0% +access SP not necessarily going now but + + + align:start position:0% +access SP not necessarily going now but +also in the + + align:start position:0% +also in the + + + align:start position:0% +also in the +future we have that ability + + align:start position:0% +future we have that ability + + + align:start position:0% +future we have that ability +toass framework with all the know issues + + align:start position:0% +toass framework with all the know issues + + + align:start position:0% +toass framework with all the know issues +with bureaucracy issues know is that a + + align:start position:0% +with bureaucracy issues know is that a + + + align:start position:0% +with bureaucracy issues know is that a +possible way for us to continue well I + + align:start position:0% +possible way for us to continue well I + + + align:start position:0% +possible way for us to continue well I +think it's very possible but the problem + + align:start position:0% +think it's very possible but the problem + + + align:start position:0% +think it's very possible but the problem +is + + align:start position:0% +is + + + align:start position:0% +is +money problem is + + align:start position:0% + + + + align:start position:0% + +investment you + + align:start position:0% +investment you + + + align:start position:0% +investment you +know investment specialist say if you + + align:start position:0% +know investment specialist say if you + + + align:start position:0% +know investment specialist say if you +can't give me a return on investment in + + align:start position:0% +can't give me a return on investment in + + + align:start position:0% +can't give me a return on investment in +three years maximum five years I don't I + + align:start position:0% +three years maximum five years I don't I + + + align:start position:0% +three years maximum five years I don't I +won't invest in it and the Aerospace + + align:start position:0% +won't invest in it and the Aerospace + + + align:start position:0% +won't invest in it and the Aerospace +industry is worse than that they don't + + align:start position:0% +industry is worse than that they don't + + + align:start position:0% +industry is worse than that they don't +have any money so they don't they aren't + + align:start position:0% +have any money so they don't they aren't + + + align:start position:0% +have any money so they don't they aren't +willing to make an investment in the + + align:start position:0% +willing to make an investment in the + + + align:start position:0% +willing to make an investment in the +future so the investors who have the + + align:start position:0% +future so the investors who have the + + + align:start position:0% +future so the investors who have the +money want to + + align:start position:0% +money want to + + + align:start position:0% +money want to +return the guys that have the capability + + align:start position:0% +return the guys that have the capability + + + align:start position:0% +return the guys that have the capability +to do it don't have the money to + + align:start position:0% +to do it don't have the money to + + + align:start position:0% +to do it don't have the money to +invest so until it gets to the point + + align:start position:0% +invest so until it gets to the point + + + align:start position:0% +invest so until it gets to the point +where it's a little more realistic from + + align:start position:0% +where it's a little more realistic from + + + align:start position:0% +where it's a little more realistic from +a return on investment it's not going to + + align:start position:0% +a return on investment it's not going to + + + align:start position:0% +a return on investment it's not going to +get to the point where commercial + + align:start position:0% +get to the point where commercial + + + align:start position:0% +get to the point where commercial +Ventures are willing to do it because + + align:start position:0% +Ventures are willing to do it because + + + align:start position:0% +Ventures are willing to do it because +it's just too expensive and the the prob + + align:start position:0% +it's just too expensive and the the prob + + + align:start position:0% +it's just too expensive and the the prob +the the probability of failure so high + + align:start position:0% +the the probability of failure so high + + + align:start position:0% +the the probability of failure so high +in our + + align:start position:0% +in our + + + align:start position:0% +in our +business that investors shy away from + + align:start position:0% +business that investors shy away from + + + align:start position:0% +business that investors shy away from +it so I think it will come to that + + align:start position:0% +it so I think it will come to that + + + align:start position:0% +it so I think it will come to that +but I don't think it's going to come + + align:start position:0% +but I don't think it's going to come + + + align:start position:0% +but I don't think it's going to come +very rapidly as it did in for instance + + align:start position:0% +very rapidly as it did in for instance + + + align:start position:0% +very rapidly as it did in for instance +in the airplane + + align:start position:0% + + + + align:start position:0% + +bu I mean even + + align:start position:0% +bu I mean even + + + align:start position:0% +bu I mean even +today we wouldn't be + + align:start position:0% +today we wouldn't be + + + align:start position:0% +today we wouldn't be +flying the transports we have or the + + align:start position:0% +flying the transports we have or the + + + align:start position:0% +flying the transports we have or the +supersonic airplanes that we have + + align:start position:0% +supersonic airplanes that we have + + + align:start position:0% +supersonic airplanes that we have +without the in government having made + + align:start position:0% +without the in government having made + + + align:start position:0% +without the in government having made +that investment at the + + align:start position:0% +that investment at the + + + align:start position:0% +that investment at the +time you know the the 707 first big + + align:start position:0% +time you know the the 707 first big + + + align:start position:0% +time you know the the 707 first big +really good jet transport was totally + + align:start position:0% +really good jet transport was totally + + + align:start position:0% +really good jet transport was totally +dependent upon the + + align:start position:0% +dependent upon the + + + align:start position:0% +dependent upon the +b47 + + align:start position:0% +b47 + + + align:start position:0% +b47 +airport which is built by the same + + align:start position:0% +airport which is built by the same + + + align:start position:0% +airport which is built by the same +people + + align:start position:0% +people + + + align:start position:0% +people +right and so it was the government + + align:start position:0% +right and so it was the government + + + align:start position:0% +right and so it was the government +investment you know everybody say well + + align:start position:0% +investment you know everybody say well + + + align:start position:0% +investment you know everybody say well +we did in the airplane business to a + + align:start position:0% +we did in the airplane business to a + + + align:start position:0% +we did in the airplane business to a +certain extent but nowhere near as much + + align:start position:0% +certain extent but nowhere near as much + + + align:start position:0% +certain extent but nowhere near as much +as people think because it was all of + + align:start position:0% +as people think because it was all of + + + align:start position:0% +as people think because it was all of +the technology was done by the in + + align:start position:0% +the technology was done by the in + + + align:start position:0% +the technology was done by the in +government investment in the airport + + align:start position:0% +government investment in the airport + + + align:start position:0% +government investment in the airport +and you know the next step the + + align:start position:0% +and you know the next step the + + + align:start position:0% +and you know the next step the +supersonic bomber or excuse me + + align:start position:0% +supersonic bomber or excuse me + + + align:start position:0% +supersonic bomber or excuse me +supersonic transport which we ought to + + align:start position:0% +supersonic transport which we ought to + + + align:start position:0% +supersonic transport which we ought to +have it's a that's another travesty that + + align:start position:0% +have it's a that's another travesty that + + + align:start position:0% +have it's a that's another travesty that +we don't have a supersonic + + align:start position:0% +we don't have a supersonic + + + align:start position:0% +we don't have a supersonic +trans + + align:start position:0% +trans + + + align:start position:0% +trans +uh that hasn't been done by Boeing or + + align:start position:0% +uh that hasn't been done by Boeing or + + + align:start position:0% +uh that hasn't been done by Boeing or +locky + + align:start position:0% +locky + + + align:start position:0% +locky +because they don't have the they aren't + + align:start position:0% +because they don't have the they aren't + + + align:start position:0% +because they don't have the they aren't +willing to + + align:start position:0% +willing to + + + align:start position:0% +willing to +invest that kind of money on their own + + align:start position:0% +invest that kind of money on their own + + + align:start position:0% +invest that kind of money on their own +so they take + + align:start position:0% +so they take + + + align:start position:0% +so they take +the the investment of the Govern govern + + align:start position:0% +the the investment of the Govern govern + + + align:start position:0% +the the investment of the Govern govern +in + + align:start position:0% +in + + + align:start position:0% +in +supersonic aerodynamics and engines and + + align:start position:0% +supersonic aerodynamics and engines and + + + align:start position:0% +supersonic aerodynamics and engines and +structure and use it in a supersonic + + align:start position:0% +structure and use it in a supersonic + + + align:start position:0% +structure and use it in a supersonic +airport so I I think it's a ways off a + + align:start position:0% +airport so I I think it's a ways off a + + + align:start position:0% +airport so I I think it's a ways off a +lot of people have tried + + align:start position:0% +lot of people have tried + + + align:start position:0% +lot of people have tried +it most notable being kler + + align:start position:0% +it most notable being kler + + + align:start position:0% +it most notable being kler +recently and have + + align:start position:0% +recently and have + + + align:start position:0% +recently and have +failed I think it can be done pro and + + align:start position:0% +failed I think it can be done pro and + + + align:start position:0% +failed I think it can be done pro and +done + + align:start position:0% +done + + + align:start position:0% +done +better you can do it better outside of + + align:start position:0% +better you can do it better outside of + + + align:start position:0% +better you can do it better outside of +the government because you don't have + + align:start position:0% +the government because you don't have + + + align:start position:0% +the government because you don't have +all those regulations to contend with + + align:start position:0% +all those regulations to contend with + + + align:start position:0% +all those regulations to contend with +and all the gaos on top of + + align:start position:0% +and all the gaos on top of + + + align:start position:0% +and all the gaos on top of +you just going to take a + + align:start position:0% + + + + align:start position:0% + +l uh I hesitate to say this but I will + + align:start position:0% +l uh I hesitate to say this but I will + + + align:start position:0% +l uh I hesitate to say this but I will +uh programs like the + + align:start position:0% +uh programs like the + + + align:start position:0% +uh programs like the +uh what's the name of Ran's + + align:start position:0% +uh what's the name of Ran's + + + align:start position:0% +uh what's the name of Ran's +vehicle big + + align:start position:0% +vehicle big + + + align:start position:0% +vehicle big +hard spaceship + + align:start position:0% +hard spaceship + + + align:start position:0% +hard spaceship +one that's trickery + + align:start position:0% + + + + align:start position:0% + +that's Child's Play what he's + + align:start position:0% +that's Child's Play what he's + + + align:start position:0% +that's Child's Play what he's +doing Wy tries to go to + + align:start position:0% + + + + align:start position:0% + +orbit that's his next + + align:start position:0% +orbit that's his next + + + align:start position:0% +orbit that's his next +step tell me when that's going to + + align:start position:0% + + + + align:start position:0% + +happen I you know he's he's kidding the + + align:start position:0% +happen I you know he's he's kidding the + + + align:start position:0% +happen I you know he's he's kidding the +world at the moment Chris Craft say + + align:start position:0% +world at the moment Chris Craft say + + + align:start position:0% +world at the moment Chris Craft say +it I I want you to remember that because + + align:start position:0% +it I I want you to remember that because + + + align:start position:0% +it I I want you to remember that because +I I could be dead wrong so but that's my + + align:start position:0% +I I could be dead wrong so but that's my + + + align:start position:0% +I I could be dead wrong so but that's my +opinion it's just child's + + align:start position:0% +opinion it's just child's + + + align:start position:0% +opinion it's just child's +prti you know we did we did the X1 in + + align:start position:0% +prti you know we did we did the X1 in + + + align:start position:0% +prti you know we did we did the X1 in +1946 and we didn't have any buckling in + + align:start position:0% +1946 and we didn't have any buckling in + + + align:start position:0% +1946 and we didn't have any buckling in +the structure either which he had where + + align:start position:0% +the structure either which he had where + + + align:start position:0% +the structure either which he had where +do you think that buckling came + + align:start position:0% +do you think that buckling came + + + align:start position:0% +do you think that buckling came +from what do you think happened + + align:start position:0% + + + + align:start position:0% + +there where' it come fromp + + align:start position:0% + + + + align:start position:0% + +it's great + + align:start position:0% +it's great + + + align:start position:0% +it's great +absolutely but don't kid yourself that + + align:start position:0% +absolutely but don't kid yourself that + + + align:start position:0% +absolutely but don't kid yourself that +you know that the next step is flying a + + align:start position:0% +you know that the next step is flying a + + + align:start position:0% +you know that the next step is flying a +machine to + + align:start position:0% + + + + align:start position:0% + +orbit yeah I I'm I'm in fault for being + + align:start position:0% +orbit yeah I I'm I'm in fault for being + + + align:start position:0% +orbit yeah I I'm I'm in fault for being +so negative about it but because you're + + align:start position:0% +so negative about it but because you're + + + align:start position:0% +so negative about it but because you're +right I think it does inspire the young + + align:start position:0% +right I think it does inspire the young + + + align:start position:0% +right I think it does inspire the young +to do + + align:start position:0% + + + + align:start position:0% + +it as much as I hate to cut us off it is + + align:start position:0% +it as much as I hate to cut us off it is + + + align:start position:0% +it as much as I hate to cut us off it is +11:00 uh class is over students again + + align:start position:0% +11:00 uh class is over students again + + + align:start position:0% +11:00 uh class is over students again +remember to pick up your papers but uh + + align:start position:0% +remember to pick up your papers but uh + + + align:start position:0% +remember to pick up your papers but uh +Chris this has been just an + + align:start position:0% +Chris this has been just an + + + align:start position:0% +Chris this has been just an +extraordinary opportunity and an + + align:start position:0% +extraordinary opportunity and an + + + align:start position:0% +extraordinary opportunity and an +experience for all of us and once more + + align:start position:0% +experience for all of us and once more + + + align:start position:0% +experience for all of us and once more +we're very appreciative appreciative we + + align:start position:0% +we're very appreciative appreciative we + + + align:start position:0% +we're very appreciative appreciative we +know you don't give very many public + + align:start position:0% +know you don't give very many public + + + align:start position:0% +know you don't give very many public +lectures these days uh and that that you + + align:start position:0% +lectures these days uh and that that you + + + align:start position:0% +lectures these days uh and that that you +chose to come here and talk to everybody + + align:start position:0% +chose to come here and talk to everybody + + + align:start position:0% +chose to come here and talk to everybody +uh at MIT we we truly appreciate and + + align:start position:0% +uh at MIT we we truly appreciate and + + + align:start position:0% +uh at MIT we we truly appreciate and +we'd like to thank you again + + align:start position:0% +we'd like to thank you again + + + align:start position:0% +we'd like to thank you again +[Applause] \ No newline at end of file diff --git a/Fp7usgx_CvM.txt b/Fp7usgx_CvM.txt new file mode 100644 index 0000000000000000000000000000000000000000..95dbf9aa82f4c61e85c212ad21cffe358a1faeed --- /dev/null +++ b/Fp7usgx_CvM.txt @@ -0,0 +1,8291 @@ +align:start position:0% + +let's get started + + align:start position:0% +let's get started + + + align:start position:0% +let's get started +so today we're gonna look at one of my + + align:start position:0% +so today we're gonna look at one of my + + + align:start position:0% +so today we're gonna look at one of my +favorite puzzles I'll say right at the + + align:start position:0% +favorite puzzles I'll say right at the + + + align:start position:0% +favorite puzzles I'll say right at the +beginning that the coding associated + + align:start position:0% +beginning that the coding associated + + + align:start position:0% +beginning that the coding associated +with the puzzle is fairly + + align:start position:0% +with the puzzle is fairly + + + align:start position:0% +with the puzzle is fairly +straightforward but the analysis + + align:start position:0% +straightforward but the analysis + + + align:start position:0% +straightforward but the analysis +associated with this puzzle is quite + + align:start position:0% +associated with this puzzle is quite + + + align:start position:0% +associated with this puzzle is quite +intricate and in particular if you're + + align:start position:0% +intricate and in particular if you're + + + align:start position:0% +intricate and in particular if you're +gonna have to do worst-case analysis + + align:start position:0% +gonna have to do worst-case analysis + + + align:start position:0% +gonna have to do worst-case analysis +which is really a good thing to for you + + align:start position:0% +which is really a good thing to for you + + + align:start position:0% +which is really a good thing to for you +to learn about because asymptotic + + align:start position:0% +to learn about because asymptotic + + + align:start position:0% +to learn about because asymptotic +analysis in algorithms is all about + + align:start position:0% +analysis in algorithms is all about + + + align:start position:0% +analysis in algorithms is all about +worst case alright so keep that in mind + + align:start position:0% +worst case alright so keep that in mind + + + align:start position:0% +worst case alright so keep that in mind +when you try to come up with answers to + + align:start position:0% +when you try to come up with answers to + + + align:start position:0% +when you try to come up with answers to +my questions always keep in mind that + + align:start position:0% +my questions always keep in mind that + + + align:start position:0% +my questions always keep in mind that +I'm going to be asking for what happens + + align:start position:0% +I'm going to be asking for what happens + + + align:start position:0% +I'm going to be asking for what happens +in the worst case know in the context of + + align:start position:0% +in the worst case know in the context of + + + align:start position:0% +in the worst case know in the context of +our puzzle which is is called the + + align:start position:0% +our puzzle which is is called the + + + align:start position:0% +our puzzle which is is called the +crystal ball puzzle and it's fairly + + align:start position:0% +crystal ball puzzle and it's fairly + + + align:start position:0% +crystal ball puzzle and it's fairly +popular in the literature though I've + + align:start position:0% +popular in the literature though I've + + + align:start position:0% +popular in the literature though I've +generalized it a little bit you have the + + align:start position:0% +generalized it a little bit you have the + + + align:start position:0% +generalized it a little bit you have the +situation where you're supposed to + + align:start position:0% +situation where you're supposed to + + + align:start position:0% +situation where you're supposed to +figure out the hardness coefficient of a + + align:start position:0% +figure out the hardness coefficient of a + + + align:start position:0% +figure out the hardness coefficient of a +crystal ball and in the generalized + + align:start position:0% +crystal ball and in the generalized + + + align:start position:0% +crystal ball and in the generalized +version you have a set of identical + + align:start position:0% +version you have a set of identical + + + align:start position:0% +version you have a set of identical +crystal balls right so how do you find + + align:start position:0% +crystal balls right so how do you find + + + align:start position:0% +crystal balls right so how do you find +this hardness coefficient well you go up + + align:start position:0% +this hardness coefficient well you go up + + + align:start position:0% +this hardness coefficient well you go up +to this Shanghai tower that has 128 + + align:start position:0% +to this Shanghai tower that has 128 + + + align:start position:0% +to this Shanghai tower that has 128 +floors one through 128 and you drop this + + align:start position:0% +floors one through 128 and you drop this + + + align:start position:0% +floors one through 128 and you drop this +ball from say floor one so just you're + + align:start position:0% +ball from say floor one so just you're + + + align:start position:0% +ball from say floor one so just you're +standing here and let's say you just + + align:start position:0% +standing here and let's say you just + + + align:start position:0% +standing here and let's say you just +drop it from there or you go up to floor + + align:start position:0% +drop it from there or you go up to floor + + + align:start position:0% +drop it from there or you go up to floor +to and you drop the ball and the + + align:start position:0% +to and you drop the ball and the + + + align:start position:0% +to and you drop the ball and the +hardness coefficient is defined as the + + align:start position:0% +hardness coefficient is defined as the + + + align:start position:0% +hardness coefficient is defined as the +highest floor from which you can drop + + align:start position:0% +highest floor from which you can drop + + + align:start position:0% +highest floor from which you can drop +the ball and the ball does not break + + align:start position:0% +the ball and the ball does not break + + + align:start position:0% +the ball and the ball does not break +okay so what this means is if floor F + + align:start position:0% +okay so what this means is if floor F + + + align:start position:0% +okay so what this means is if floor F +the ball doesn't break + + align:start position:0% + + + + align:start position:0% + +and it breaks at f+ 1 then the hardness + + align:start position:0% +and it breaks at f+ 1 then the hardness + + + align:start position:0% +and it breaks at f+ 1 then the hardness +coefficient is F and you can assume a + + align:start position:0% +coefficient is F and you can assume a + + + align:start position:0% +coefficient is F and you can assume a +monotone a city properly that says that + + align:start position:0% +monotone a city properly that says that + + + align:start position:0% +monotone a city properly that says that +if it did not break at floor F then it + + align:start position:0% +if it did not break at floor F then it + + + align:start position:0% +if it did not break at floor F then it +won't break this implies that it won't + + align:start position:0% +won't break this implies that it won't + + + align:start position:0% +won't break this implies that it won't +break it at any floor less than or equal + + align:start position:0% +break it at any floor less than or equal + + + align:start position:0% +break it at any floor less than or equal +to F okay which makes sense right + + align:start position:0% +to F okay which makes sense right + + + align:start position:0% +to F okay which makes sense right +I'm not otherwise it would be kind of + + align:start position:0% +I'm not otherwise it would be kind of + + + align:start position:0% +I'm not otherwise it would be kind of +complicated it would be random and + + align:start position:0% +complicated it would be random and + + + align:start position:0% +complicated it would be random and +everyone be able to do any interesting + + align:start position:0% +everyone be able to do any interesting + + + align:start position:0% +everyone be able to do any interesting +analysis um so the easy a version of the + + align:start position:0% +analysis um so the easy a version of the + + + align:start position:0% +analysis um so the easy a version of the +puzzle of course which is not + + align:start position:0% +puzzle of course which is not + + + align:start position:0% +puzzle of course which is not +particularly interesting is if you need + + align:start position:0% +particularly interesting is if you need + + + align:start position:0% +particularly interesting is if you need +it to get this this exactly right so + + align:start position:0% +it to get this this exactly right so + + + align:start position:0% +it to get this this exactly right so +your job depends on getting that number + + align:start position:0% +your job depends on getting that number + + + align:start position:0% +your job depends on getting that number +exactly right so there's no shortcuts + + align:start position:0% +exactly right so there's no shortcuts + + + align:start position:0% +exactly right so there's no shortcuts +you got to get it right you can't be off + + align:start position:0% +you got to get it right you can't be off + + + align:start position:0% +you got to get it right you can't be off +by one either way and I you I have only + + align:start position:0% +by one either way and I you I have only + + + align:start position:0% +by one either way and I you I have only +one ball right so you only have one ball + + align:start position:0% +one ball right so you only have one ball + + + align:start position:0% +one ball right so you only have one ball +so so what can you do if you only have + + align:start position:0% +so so what can you do if you only have + + + align:start position:0% +so so what can you do if you only have +one ball and you have to get it exactly + + align:start position:0% +one ball and you have to get it exactly + + + align:start position:0% +one ball and you have to get it exactly +right + + align:start position:0% +right + + + align:start position:0% +right +try every floor right and and but more + + align:start position:0% +try every floor right and and but more + + + align:start position:0% +try every floor right and and but more +important I try from lower floors to + + align:start position:0% +important I try from lower floors to + + + align:start position:0% +important I try from lower floors to +higher floors right so you drop it at + + align:start position:0% +higher floors right so you drop it at + + + align:start position:0% +higher floors right so you drop it at +floor one I saw one ball you drop from + + align:start position:0% +floor one I saw one ball you drop from + + + align:start position:0% +floor one I saw one ball you drop from +floor one and if it in and if it breaks + + align:start position:0% +floor one and if it in and if it breaks + + + align:start position:0% +floor one and if it in and if it breaks +then your hardness coefficient is is you + + align:start position:0% +then your hardness coefficient is is you + + + align:start position:0% +then your hardness coefficient is is you +return zero but then if you keep going + + align:start position:0% +return zero but then if you keep going + + + align:start position:0% +return zero but then if you keep going +and it and it let's say you drop I've + + align:start position:0% +and it and it let's say you drop I've + + + align:start position:0% +and it and it let's say you drop I've +got a dot from floor 65 and it breaks + + align:start position:0% +got a dot from floor 65 and it breaks + + + align:start position:0% +got a dot from floor 65 and it breaks +and you've gone in order then the + + align:start position:0% +and you've gone in order then the + + + align:start position:0% +and you've gone in order then the +hardness coefficient is 64 okay right so + + align:start position:0% +hardness coefficient is 64 okay right so + + + align:start position:0% +hardness coefficient is 64 okay right so +that's easy enough there's there's no + + align:start position:0% +that's easy enough there's there's no + + + align:start position:0% +that's easy enough there's there's no +optimization here it's the only thing + + align:start position:0% +optimization here it's the only thing + + + align:start position:0% +optimization here it's the only thing +you can do so that's why it's not + + align:start position:0% +you can do so that's why it's not + + + align:start position:0% +you can do so that's why it's not +particularly interesting now if you have + + align:start position:0% +particularly interesting now if you have + + + align:start position:0% +particularly interesting now if you have +identical crystal balls that are + + align:start position:0% +identical crystal balls that are + + + align:start position:0% +identical crystal balls that are +guaranteed + + align:start position:0% +guaranteed + + + align:start position:0% +guaranteed +they were manufactured in exactly the + + align:start position:0% +they were manufactured in exactly the + + + align:start position:0% +they were manufactured in exactly the +same way + + align:start position:0% +same way + + + align:start position:0% +same way +etc etc then obviously things get a lot + + align:start position:0% +etc etc then obviously things get a lot + + + align:start position:0% +etc etc then obviously things get a lot +more interesting because you can try to + + align:start position:0% +more interesting because you can try to + + + align:start position:0% +more interesting because you can try to +minimize something and I'm gonna write + + align:start position:0% +minimize something and I'm gonna write + + + align:start position:0% +minimize something and I'm gonna write +it over here because I want you to keep + + align:start position:0% +it over here because I want you to keep + + + align:start position:0% +it over here because I want you to keep +this in mind throughout the lecture our + + align:start position:0% +this in mind throughout the lecture our + + + align:start position:0% +this in mind throughout the lecture our +goal here is to minimize the worst case + + align:start position:0% + + + + align:start position:0% + +number of drops for our problem and if + + align:start position:0% +number of drops for our problem and if + + + align:start position:0% +number of drops for our problem and if +we want to we want to solve the problem + + align:start position:0% +we want to we want to solve the problem + + + align:start position:0% +we want to we want to solve the problem +in the general case with the balls and I + + align:start position:0% +in the general case with the balls and I + + + align:start position:0% +in the general case with the balls and I +should say D identical balls but more + + align:start position:0% +should say D identical balls but more + + + align:start position:0% +should say D identical balls but more +important the reason I'm writing this up + + align:start position:0% +important the reason I'm writing this up + + + align:start position:0% +important the reason I'm writing this up +is as I said before we need to focus on + + align:start position:0% +is as I said before we need to focus on + + + align:start position:0% +is as I said before we need to focus on +the worst case right so it may be the + + align:start position:0% +the worst case right so it may be the + + + align:start position:0% +the worst case right so it may be the +case that for a given set of balls your + + align:start position:0% +case that for a given set of balls your + + + align:start position:0% +case that for a given set of balls your +algorithm does very well I in in in the + + align:start position:0% +algorithm does very well I in in in the + + + align:start position:0% +algorithm does very well I in in in the +sense that the hardness coefficient + + align:start position:0% +sense that the hardness coefficient + + + align:start position:0% +sense that the hardness coefficient +happened to be 42 and you you picked the + + align:start position:0% +happened to be 42 and you you picked the + + + align:start position:0% +happened to be 42 and you you picked the +floor as as of 41 to begin with and so + + align:start position:0% +floor as as of 41 to begin with and so + + + align:start position:0% +floor as as of 41 to begin with and so +you drop from 41 and it doesn't break + + align:start position:0% +you drop from 41 and it doesn't break + + + align:start position:0% +you drop from 41 and it doesn't break +and then you go to 42 and it doesn't + + align:start position:0% +and then you go to 42 and it doesn't + + + align:start position:0% +and then you go to 42 and it doesn't +break and you go to 43 and it doesn't M + + align:start position:0% +break and you go to 43 and it doesn't M + + + align:start position:0% +break and you go to 43 and it doesn't M +it breaks and you go oh I only needed + + align:start position:0% +it breaks and you go oh I only needed + + + align:start position:0% +it breaks and you go oh I only needed +two drops for this particular problem + + align:start position:0% +two drops for this particular problem + + + align:start position:0% +two drops for this particular problem +but but if you but if the hardness + + align:start position:0% +but but if you but if the hardness + + + align:start position:0% +but but if you but if the hardness +coefficient happened to be a 65 and you + + align:start position:0% +coefficient happened to be a 65 and you + + + align:start position:0% +coefficient happened to be a 65 and you +started from floor 41 I mean you need 20 + + align:start position:0% +started from floor 41 I mean you need 20 + + + align:start position:0% +started from floor 41 I mean you need 20 +odd number of drops right so you have to + + align:start position:0% +odd number of drops right so you have to + + + align:start position:0% +odd number of drops right so you have to +be careful I in that you have to analyze + + align:start position:0% +be careful I in that you have to analyze + + + align:start position:0% +be careful I in that you have to analyze +whatever strategy you come up with I in + + align:start position:0% +whatever strategy you come up with I in + + + align:start position:0% +whatever strategy you come up with I in +the case where the hardness coefficient + + align:start position:0% +the case where the hardness coefficient + + + align:start position:0% +the case where the hardness coefficient +could be pretty much anything I mean it + + align:start position:0% +could be pretty much anything I mean it + + + align:start position:0% +could be pretty much anything I mean it +could be zero or it could be 128 all + + align:start position:0% +could be zero or it could be 128 all + + + align:start position:0% +could be zero or it could be 128 all +right I'm not a Shanghai Tower example + + align:start position:0% +right I'm not a Shanghai Tower example + + + align:start position:0% +right I'm not a Shanghai Tower example +all right so the first interesting + + align:start position:0% +all right so the first interesting + + + align:start position:0% +all right so the first interesting +question is what happens when I have two + + align:start position:0% +question is what happens when I have two + + + align:start position:0% +question is what happens when I have two +identical balls right so oh before we do + + align:start position:0% +identical balls right so oh before we do + + + align:start position:0% +identical balls right so oh before we do +that + + align:start position:0% +that + + + align:start position:0% +that +according to according to my metric here + + align:start position:0% +according to according to my metric here + + + align:start position:0% +according to according to my metric here +what is the worst case + + align:start position:0% +what is the worst case + + + align:start position:0% +what is the worst case +number of drops for one ball what is the + + align:start position:0% +number of drops for one ball what is the + + + align:start position:0% +number of drops for one ball what is the +worst case number of drops for one ball + + align:start position:0% +worst case number of drops for one ball + + + align:start position:0% +worst case number of drops for one ball +give me a number + + align:start position:0% +give me a number + + + align:start position:0% +give me a number +someone else yeah back there 128 exactly + + align:start position:0% +someone else yeah back there 128 exactly + + + align:start position:0% +someone else yeah back there 128 exactly +right so it's it's 128 because I could + + align:start position:0% +right so it's it's 128 because I could + + + align:start position:0% +right so it's it's 128 because I could +have had a ball that doesn't break from + + align:start position:0% +have had a ball that doesn't break from + + + align:start position:0% +have had a ball that doesn't break from +the 128 floor I don't know that to begin + + align:start position:0% +the 128 floor I don't know that to begin + + + align:start position:0% +the 128 floor I don't know that to begin +with I have to start with floor 1 and I + + align:start position:0% +with I have to start with floor 1 and I + + + align:start position:0% +with I have to start with floor 1 and I +gotta go 1 2 3 4 etc right so the worst + + align:start position:0% +gotta go 1 2 3 4 etc right so the worst + + + align:start position:0% +gotta go 1 2 3 4 etc right so the worst +case for one ball is 128 and then you + + align:start position:0% +case for one ball is 128 and then you + + + align:start position:0% +case for one ball is 128 and then you +can't do better than that alright it but + + align:start position:0% +can't do better than that alright it but + + + align:start position:0% +can't do better than that alright it but +of course it gets more interesting when + + align:start position:0% +of course it gets more interesting when + + + align:start position:0% +of course it gets more interesting when +D is large right so so our goal now is + + align:start position:0% +D is large right so so our goal now is + + + align:start position:0% +D is large right so so our goal now is +to discover an algorithm that is going + + align:start position:0% +to discover an algorithm that is going + + + align:start position:0% +to discover an algorithm that is going +to minimize the worst case number of + + align:start position:0% +to minimize the worst case number of + + + align:start position:0% +to minimize the worst case number of +drops for D equals 2 okay that's that's + + align:start position:0% +drops for D equals 2 okay that's that's + + + align:start position:0% +drops for D equals 2 okay that's that's +our that's our current goal right and + + align:start position:0% +our that's our current goal right and + + + align:start position:0% +our that's our current goal right and +then we'll look at more even more + + align:start position:0% +then we'll look at more even more + + + align:start position:0% +then we'll look at more even more +general things so how would you do if + + align:start position:0% +general things so how would you do if + + + align:start position:0% +general things so how would you do if +thinks if you had D equals 2 right it + + align:start position:0% +thinks if you had D equals 2 right it + + + align:start position:0% +thinks if you had D equals 2 right it +just it doesn't matter if you don't get + + align:start position:0% +just it doesn't matter if you don't get + + + align:start position:0% +just it doesn't matter if you don't get +the algorithm right I'll let me analyze + + align:start position:0% +the algorithm right I'll let me analyze + + + align:start position:0% +the algorithm right I'll let me analyze +it you propose something you'll analyze + + align:start position:0% +it you propose something you'll analyze + + + align:start position:0% +it you propose something you'll analyze +it and then we'll decide if we can do + + align:start position:0% +it and then we'll decide if we can do + + + align:start position:0% +it and then we'll decide if we can do +better or not yeah go ahead + + align:start position:0% + + + + align:start position:0% + +Oh use the bottom half excellent what's + + align:start position:0% +Oh use the bottom half excellent what's + + + align:start position:0% +Oh use the bottom half excellent what's +your name sorry Domon um and so so so + + align:start position:0% +your name sorry Domon um and so so so + + + align:start position:0% +your name sorry Domon um and so so so +Domon says that we should do binary + + align:start position:0% +Domon says that we should do binary + + + align:start position:0% +Domon says that we should do binary +search right which is very intuitive and + + align:start position:0% +search right which is very intuitive and + + + align:start position:0% +search right which is very intuitive and +kind of make sense in a lot of context + + align:start position:0% +kind of make sense in a lot of context + + + align:start position:0% +kind of make sense in a lot of context +including this one and so let's drop + + align:start position:0% +including this one and so let's drop + + + align:start position:0% +including this one and so let's drop +from sorry from 64 and the reason she + + align:start position:0% +from sorry from 64 and the reason she + + + align:start position:0% +from sorry from 64 and the reason she +picked that is because 128 divided by 2 + + align:start position:0% +picked that is because 128 divided by 2 + + + align:start position:0% +picked that is because 128 divided by 2 +is 64 and if it breaks then I you need + + align:start position:0% +is 64 and if it breaks then I you need + + + align:start position:0% +is 64 and if it breaks then I you need +to look at the interval 1 comma 63 right + + align:start position:0% +to look at the interval 1 comma 63 right + + + align:start position:0% +to look at the interval 1 comma 63 right +because it if it I'm sorry if it yeah + + align:start position:0% +because it if it I'm sorry if it yeah + + + align:start position:0% +because it if it I'm sorry if it yeah +that's right if it if it breaks you you + + align:start position:0% +that's right if it if it breaks you you + + + align:start position:0% +that's right if it if it breaks you you +need to look at the interval 1 comma 63 + + align:start position:0% +need to look at the interval 1 comma 63 + + + align:start position:0% +need to look at the interval 1 comma 63 +with the second ball I mean that that + + align:start position:0% +with the second ball I mean that that + + + align:start position:0% +with the second ball I mean that that +first ball is gone okay it shards of + + align:start position:0% +first ball is gone okay it shards of + + + align:start position:0% +first ball is gone okay it shards of +crystal or whatever you want to call it + + align:start position:0% +crystal or whatever you want to call it + + + align:start position:0% +crystal or whatever you want to call it +um so so you just have the second ball + + align:start position:0% +um so so you just have the second ball + + + align:start position:0% +um so so you just have the second ball +and so now at this point you have no + + align:start position:0% +and so now at this point you have no + + + align:start position:0% +and so now at this point you have no +choice + + align:start position:0% +choice + + + align:start position:0% +choice +alright you only have one ball left + + align:start position:0% +alright you only have one ball left + + + align:start position:0% +alright you only have one ball left +right as I mentioned your job depends on + + align:start position:0% +right as I mentioned your job depends on + + + align:start position:0% +right as I mentioned your job depends on +getting that hardness coefficient right + + align:start position:0% +getting that hardness coefficient right + + + align:start position:0% +getting that hardness coefficient right +so you can only use that first algorithm + + align:start position:0% +so you can only use that first algorithm + + + align:start position:0% +so you can only use that first algorithm +in terms of starting from 1 and going + + align:start position:0% +in terms of starting from 1 and going + + + align:start position:0% +in terms of starting from 1 and going +all the way to 63 and so what is the + + align:start position:0% +all the way to 63 and so what is the + + + align:start position:0% +all the way to 63 and so what is the +worst case number of drops given that + + align:start position:0% +worst case number of drops given that + + + align:start position:0% +worst case number of drops given that +diamond picked the midpoint for this + + align:start position:0% +diamond picked the midpoint for this + + + align:start position:0% +diamond picked the midpoint for this +algorithm someone else yeah go ahead + + align:start position:0% + + + + align:start position:0% + +it's succeed 63 + + align:start position:0% +it's succeed 63 + + + align:start position:0% +it's succeed 63 +no actually it's you're off by one + + align:start position:0% +no actually it's you're off by one + + + align:start position:0% +no actually it's you're off by one +because I did drop the ball here right + + align:start position:0% +because I did drop the ball here right + + + align:start position:0% +because I did drop the ball here right +so so close so I first ball I was + + align:start position:0% +so so close so I first ball I was + + + align:start position:0% +so so close so I first ball I was +dropped once one drop and at this one if + + align:start position:0% +dropped once one drop and at this one if + + + align:start position:0% +dropped once one drop and at this one if +in fact you at the hardness coefficient + + align:start position:0% +in fact you at the hardness coefficient + + + align:start position:0% +in fact you at the hardness coefficient +was 64 you drop the second ball 62 63 + + align:start position:0% +was 64 you drop the second ball 62 63 + + + align:start position:0% +was 64 you drop the second ball 62 63 +times and that would be the worst case + + align:start position:0% +times and that would be the worst case + + + align:start position:0% +times and that would be the worst case +in the in this instance now I've skipped + + align:start position:0% +in the in this instance now I've skipped + + + align:start position:0% +in the in this instance now I've skipped +over one little thing at the fact that + + align:start position:0% +over one little thing at the fact that + + + align:start position:0% +over one little thing at the fact that +this is the midpoint implies that this + + align:start position:0% +this is the midpoint implies that this + + + align:start position:0% +this is the midpoint implies that this +is in fact the correct answer but we do + + align:start position:0% +is in fact the correct answer but we do + + + align:start position:0% +is in fact the correct answer but we do +have to analyze I mean remember you know + + align:start position:0% +have to analyze I mean remember you know + + + align:start position:0% +have to analyze I mean remember you know +when you do analysis you do have to + + align:start position:0% +when you do analysis you do have to + + + align:start position:0% +when you do analysis you do have to +cover the entire spectrum here so you do + + align:start position:0% +cover the entire spectrum here so you do + + + align:start position:0% +cover the entire spectrum here so you do +have to Kate it look at the case where + + align:start position:0% +have to Kate it look at the case where + + + align:start position:0% +have to Kate it look at the case where +the drop from 64 it does not break okay + + align:start position:0% +the drop from 64 it does not break okay + + + align:start position:0% +the drop from 64 it does not break okay +and in that case you're looking at + + align:start position:0% +and in that case you're looking at + + + align:start position:0% +and in that case you're looking at +looking at 65 through 128 but you do + + align:start position:0% +looking at 65 through 128 but you do + + + align:start position:0% +looking at 65 through 128 but you do +have two balls for this right it didn't + + align:start position:0% +have two balls for this right it didn't + + + align:start position:0% +have two balls for this right it didn't +break so you still have two balls for + + align:start position:0% +break so you still have two balls for + + + align:start position:0% +break so you still have two balls for +that right and so you can imagine that + + align:start position:0% +that right and so you can imagine that + + + align:start position:0% +that right and so you can imagine that +now that you have two balls and you have + + align:start position:0% +now that you have two balls and you have + + + align:start position:0% +now that you have two balls and you have +a small interval that you're going to be + + align:start position:0% +a small interval that you're going to be + + + align:start position:0% +a small interval that you're going to be +able to do something like 32 for that + + align:start position:0% +able to do something like 32 for that + + + align:start position:0% +able to do something like 32 for that +the bottom line is you don't even need + + align:start position:0% +the bottom line is you don't even need + + + align:start position:0% +the bottom line is you don't even need +you can get a little bit lazy here you + + align:start position:0% +you can get a little bit lazy here you + + + align:start position:0% +you can get a little bit lazy here you +don't really need to analyze what the + + align:start position:0% +don't really need to analyze what the + + + align:start position:0% +don't really need to analyze what the +number is because you know that this + + align:start position:0% +number is because you know that this + + + align:start position:0% +number is because you know that this +number 63 plus 1is is larger than that + + align:start position:0% +number 63 plus 1is is larger than that + + + align:start position:0% +number 63 plus 1is is larger than that +right because you want it worst case + + align:start position:0% +right because you want it worst case + + + align:start position:0% +right because you want it worst case +right so this is the kind of thing that + + align:start position:0% +right so this is the kind of thing that + + + align:start position:0% +right so this is the kind of thing that +you have to do when you do algorithmic + + align:start position:0% +you have to do when you do algorithmic + + + align:start position:0% +you have to do when you do algorithmic +analysis maybe not exactly if I in in a + + align:start position:0% +analysis maybe not exactly if I in in a + + + align:start position:0% +analysis maybe not exactly if I in in a +puzzle situation like this but you have + + align:start position:0% +puzzle situation like this but you have + + + align:start position:0% +puzzle situation like this but you have +to look at all the cases right then you + + align:start position:0% +to look at all the cases right then you + + + align:start position:0% +to look at all the cases right then you +have to find kind of the max of all the + + align:start position:0% +have to find kind of the max of all the + + + align:start position:0% +have to find kind of the max of all the +cases right so is this the best you can + + align:start position:0% +cases right so is this the best you can + + + align:start position:0% +cases right so is this the best you can +do yeah go ahead + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% + + + + align:start position:0% + +every 16 + + align:start position:0% + + + + align:start position:0% + +30 seconds you have to only test + + align:start position:0% + + + + align:start position:0% + +that's correct yeah I mean this is + + align:start position:0% +that's correct yeah I mean this is + + + align:start position:0% +that's correct yeah I mean this is +obviously there's not gonna be a whole + + align:start position:0% +obviously there's not gonna be a whole + + + align:start position:0% +obviously there's not gonna be a whole +lot of optimization here but V equals + + align:start position:0% +lot of optimization here but V equals + + + align:start position:0% +lot of optimization here but V equals +two but you'd be surprised as to how + + align:start position:0% +two but you'd be surprised as to how + + + align:start position:0% +two but you'd be surprised as to how +much better you can do then 64 which is + + align:start position:0% +much better you can do then 64 which is + + + align:start position:0% +much better you can do then 64 which is +obviously a big step forward from 128 + + align:start position:0% +obviously a big step forward from 128 + + + align:start position:0% +obviously a big step forward from 128 +but you can you can go a few more steps + + align:start position:0% +but you can you can go a few more steps + + + align:start position:0% +but you can you can go a few more steps +as well and so what was your name Lucy + + align:start position:0% +as well and so what was your name Lucy + + + align:start position:0% +as well and so what was your name Lucy +so Lucy has it right you it's it's a + + align:start position:0% +so Lucy has it right you it's it's a + + + align:start position:0% +so Lucy has it right you it's it's a +similar idea except you don't + + align:start position:0% +similar idea except you don't + + + align:start position:0% +similar idea except you don't +necessarily need to do the intuitive + + align:start position:0% +necessarily need to do the intuitive + + + align:start position:0% +necessarily need to do the intuitive +binary search it's actually kind of + + align:start position:0% +binary search it's actually kind of + + + align:start position:0% +binary search it's actually kind of +different from that because of the way + + align:start position:0% +different from that because of the way + + + align:start position:0% +different from that because of the way +this problem is structured and what her + + align:start position:0% +this problem is structured and what her + + + align:start position:0% +this problem is structured and what her +idea is is that we'll we look at + + align:start position:0% +idea is is that we'll we look at + + + align:start position:0% +idea is is that we'll we look at +something smaller a smaller interval + + align:start position:0% +something smaller a smaller interval + + + align:start position:0% +something smaller a smaller interval +okay and that she picks 16 so let's go + + align:start position:0% +okay and that she picks 16 so let's go + + + align:start position:0% +okay and that she picks 16 so let's go +1632 sour algorithm is something that + + align:start position:0% +1632 sour algorithm is something that + + + align:start position:0% +1632 sour algorithm is something that +goes 16 32 48 64 that a dot and you know + + align:start position:0% +goes 16 32 48 64 that a dot and you know + + + align:start position:0% +goes 16 32 48 64 that a dot and you know +maybe gets up all the way to I guess six + + align:start position:0% +maybe gets up all the way to I guess six + + + align:start position:0% +maybe gets up all the way to I guess six +yeah 128 and 16 16 is a it's 128 is a + + align:start position:0% +yeah 128 and 16 16 is a it's 128 is a + + + align:start position:0% +yeah 128 and 16 16 is a it's 128 is a +multiple of 16 right some some math + + align:start position:0% +multiple of 16 right some some math + + + align:start position:0% +multiple of 16 right some some math +person tell make sure I'm right so so + + align:start position:0% +person tell make sure I'm right so so + + + align:start position:0% +person tell make sure I'm right so so +you have so what happens here so let's + + align:start position:0% +you have so what happens here so let's + + + align:start position:0% +you have so what happens here so let's +analyze this and to make sure that we're + + align:start position:0% +analyze this and to make sure that we're + + + align:start position:0% +analyze this and to make sure that we're +good in terms of an improvement right we + + align:start position:0% +good in terms of an improvement right we + + + align:start position:0% +good in terms of an improvement right we +have to be careful so let's just + + align:start position:0% +have to be careful so let's just + + + align:start position:0% +have to be careful so let's just +arbitrarily say that it broke it's 64 + + align:start position:0% +arbitrarily say that it broke it's 64 + + + align:start position:0% +arbitrarily say that it broke it's 64 +okay because that's kind of what + + align:start position:0% +okay because that's kind of what + + + align:start position:0% +okay because that's kind of what +happened over in that previous algorithm + + align:start position:0% +happened over in that previous algorithm + + + align:start position:0% +happened over in that previous algorithm +to so that means I've done four drops + + align:start position:0% +to so that means I've done four drops + + + align:start position:0% +to so that means I've done four drops +without a break right I'm sorry four + + align:start position:0% +without a break right I'm sorry four + + + align:start position:0% +without a break right I'm sorry four +drops three drops without a break and + + align:start position:0% +drops three drops without a break and + + + align:start position:0% +drops three drops without a break and +four drops total right um so I've done + + align:start position:0% +four drops total right um so I've done + + + align:start position:0% +four drops total right um so I've done +four drops but now the cool thing is I + + align:start position:0% +four drops but now the cool thing is I + + + align:start position:0% +four drops but now the cool thing is I +don't have to start from 16 I can Stein + + align:start position:0% +don't have to start from 16 I can Stein + + + align:start position:0% +don't have to start from 16 I can Stein +oh it didn't break at 48 right so so I + + align:start position:0% +oh it didn't break at 48 right so so I + + + align:start position:0% +oh it didn't break at 48 right so so I +can I can now look at 4 drop still break + + align:start position:0% +can I can now look at 4 drop still break + + + align:start position:0% +can I can now look at 4 drop still break +a first-ball + + align:start position:0% +a first-ball + + + align:start position:0% +a first-ball +that is what I wanted to say and now I + + align:start position:0% +that is what I wanted to say and now I + + + align:start position:0% +that is what I wanted to say and now I +need I can look at the interval 48 49 + + align:start position:0% +need I can look at the interval 48 49 + + + align:start position:0% +need I can look at the interval 48 49 +because 48 it did not break right 49 to + + align:start position:0% +because 48 it did not break right 49 to + + + align:start position:0% +because 48 it did not break right 49 to +63 inclusive right and so if you do that + + align:start position:0% +63 inclusive right and so if you do that + + + align:start position:0% +63 inclusive right and so if you do that +that's 15 it's 15 + + align:start position:0% +that's 15 it's 15 + + + align:start position:0% +that's 15 it's 15 +the difference is 14 but it's inclusive + + align:start position:0% +the difference is 14 but it's inclusive + + + align:start position:0% +the difference is 14 but it's inclusive +so it's 15 so 15 plus 4 right there is + + align:start position:0% +so it's 15 so 15 plus 4 right there is + + + align:start position:0% +so it's 15 so 15 plus 4 right there is +19 drops all right + + align:start position:0% +19 drops all right + + + align:start position:0% +19 drops all right +yeah yes that's absolutely correct so so + + align:start position:0% +yeah yes that's absolutely correct so so + + + align:start position:0% +yeah yes that's absolutely correct so so +19 is not the worst case I mean it is + + align:start position:0% +19 is not the worst case I mean it is + + + align:start position:0% +19 is not the worst case I mean it is +looking good but this was exactly the + + align:start position:0% +looking good but this was exactly the + + + align:start position:0% +looking good but this was exactly the +point I was trying to make right from + + align:start position:0% +point I was trying to make right from + + + align:start position:0% +point I was trying to make right from +the beginning you're not done yet I mean + + align:start position:0% +the beginning you're not done yet I mean + + + align:start position:0% +the beginning you're not done yet I mean +you cannot just go off and say that 19 + + align:start position:0% +you cannot just go off and say that 19 + + + align:start position:0% +you cannot just go off and say that 19 +is the worst case for this algorithm the + + align:start position:0% +is the worst case for this algorithm the + + + align:start position:0% +is the worst case for this algorithm the +worst case for this out this particular + + align:start position:0% +worst case for this out this particular + + + align:start position:0% +worst case for this out this particular +algorithm occurs at a different point + + align:start position:0% +algorithm occurs at a different point + + + align:start position:0% +algorithm occurs at a different point +from the original algorithm that went + + align:start position:0% +from the original algorithm that went + + + align:start position:0% +from the original algorithm that went +Midway right every algorithm is + + align:start position:0% +Midway right every algorithm is + + + align:start position:0% +Midway right every algorithm is +different the parameters are are + + align:start position:0% +different the parameters are are + + + align:start position:0% +different the parameters are are +different here and so I'm just calling + + align:start position:0% +different here and so I'm just calling + + + align:start position:0% +different here and so I'm just calling +it a different algorithm but the the + + align:start position:0% +it a different algorithm but the the + + + align:start position:0% +it a different algorithm but the the +case that would happen is I guess you'd + + align:start position:0% +case that would happen is I guess you'd + + + align:start position:0% +case that would happen is I guess you'd +have 112 here and then you'd go 1 2 so + + align:start position:0% +have 112 here and then you'd go 1 2 so + + + align:start position:0% +have 112 here and then you'd go 1 2 so +how many so let's say it gets to 128 and + + align:start position:0% +how many so let's say it gets to 128 and + + + align:start position:0% +how many so let's say it gets to 128 and +if it doesn't break then you're clearly + + align:start position:0% +if it doesn't break then you're clearly + + + align:start position:0% +if it doesn't break then you're clearly +done so that's not the worst case right + + align:start position:0% +done so that's not the worst case right + + + align:start position:0% +done so that's not the worst case right +so if it gets to 128 and it and it + + align:start position:0% +so if it gets to 128 and it and it + + + align:start position:0% +so if it gets to 128 and it and it +breaks then so how many drops have we + + align:start position:0% +breaks then so how many drops have we + + + align:start position:0% +breaks then so how many drops have we +done 128 divided by 16 is what is 8 are + + align:start position:0% +done 128 divided by 16 is what is 8 are + + + align:start position:0% +done 128 divided by 16 is what is 8 are +you sure you're all sure ok then I'm + + align:start position:0% +you sure you're all sure ok then I'm + + + align:start position:0% +you sure you're all sure ok then I'm +sure so that's 8 drops and now you need + + align:start position:0% +sure so that's 8 drops and now you need + + + align:start position:0% +sure so that's 8 drops and now you need +to do 113 to 127 and that we know is 15 + + align:start position:0% +to do 113 to 127 and that we know is 15 + + + align:start position:0% +to do 113 to 127 and that we know is 15 +so that's 23 all right so so the best + + align:start position:0% +so that's 23 all right so so the best + + + align:start position:0% +so that's 23 all right so so the best +you've done here is it's 23 right but + + align:start position:0% +you've done here is it's 23 right but + + + align:start position:0% +you've done here is it's 23 right but +I'll be satisfied we're never satisfied + + align:start position:0% +I'll be satisfied we're never satisfied + + + align:start position:0% +I'll be satisfied we're never satisfied +right you always want to do a little bit + + align:start position:0% +right you always want to do a little bit + + + align:start position:0% +right you always want to do a little bit +better okay so so how did she pick 16 + + align:start position:0% +better okay so so how did she pick 16 + + + align:start position:0% +better okay so so how did she pick 16 +why did you come up with 16 losing it + + align:start position:0% +why did you come up with 16 losing it + + + align:start position:0% +why did you come up with 16 losing it +looked like a nice number + + align:start position:0% +looked like a nice number + + + align:start position:0% +looked like a nice number +you just figured oh nice okay so so so + + align:start position:0% +you just figured oh nice okay so so so + + + align:start position:0% +you just figured oh nice okay so so so +if you had 17 then we would have real + + align:start position:0% +if you had 17 then we would have real + + + align:start position:0% +if you had 17 then we would have real +trouble right with all these numbers + + align:start position:0% +trouble right with all these numbers + + + align:start position:0% +trouble right with all these numbers +yeah go ahead + + align:start position:0% + + + + align:start position:0% + +beautiful beautiful I love you guys + + align:start position:0% +beautiful beautiful I love you guys + + + align:start position:0% +beautiful beautiful I love you guys +you guys make it so easy so that's the + + align:start position:0% +you guys make it so easy so that's the + + + align:start position:0% +you guys make it so easy so that's the +next thing I was going to try and pry + + align:start position:0% +next thing I was going to try and pry + + + align:start position:0% +next thing I was going to try and pry +out of you but you got it out without + + align:start position:0% +out of you but you got it out without + + + align:start position:0% +out of you but you got it out without +much effort from me so you can you can + + align:start position:0% +much effort from me so you can you can + + + align:start position:0% +much effort from me so you can you can +kind of get analytical here as opposed + + align:start position:0% +kind of get analytical here as opposed + + + align:start position:0% +kind of get analytical here as opposed +to doing things and particularly which + + align:start position:0% +to doing things and particularly which + + + align:start position:0% +to doing things and particularly which +was you know try a number and figure out + + align:start position:0% +was you know try a number and figure out + + + align:start position:0% +was you know try a number and figure out +what happened which is kind of what we + + align:start position:0% +what happened which is kind of what we + + + align:start position:0% +what happened which is kind of what we +did and you can be a little more + + align:start position:0% +did and you can be a little more + + + align:start position:0% +did and you can be a little more +analytical about this and you could say + + align:start position:0% +analytical about this and you could say + + + align:start position:0% +analytical about this and you could say +hey I'm suppose I want to find this + + align:start position:0% +hey I'm suppose I want to find this + + + align:start position:0% +hey I'm suppose I want to find this +number K which is kind of the 64 started + + align:start position:0% +number K which is kind of the 64 started + + + align:start position:0% +number K which is kind of the 64 started +with 64 went to 16 and now we're + + align:start position:0% +with 64 went to 16 and now we're + + + align:start position:0% +with 64 went to 16 and now we're +thinking we can do better than 16 even + + align:start position:0% +thinking we can do better than 16 even + + + align:start position:0% +thinking we can do better than 16 even +and we start dropping things at K 2 K 3 + + align:start position:0% +and we start dropping things at K 2 K 3 + + + align:start position:0% +and we start dropping things at K 2 K 3 +K and I want to get this exactly right + + align:start position:0% +K and I want to get this exactly right + + + align:start position:0% +K and I want to get this exactly right +so let me look at my notes and you go + + align:start position:0% +so let me look at my notes and you go + + + align:start position:0% +so let me look at my notes and you go +dot a dot n divided by K minus 1 times K + + align:start position:0% +dot a dot n divided by K minus 1 times K + + + align:start position:0% +dot a dot n divided by K minus 1 times K +and n divided by K times K which is + + align:start position:0% +and n divided by K times K which is + + + align:start position:0% +and n divided by K times K which is +obviously M and so I I'm trying to I'm + + align:start position:0% +obviously M and so I I'm trying to I'm + + + align:start position:0% +obviously M and so I I'm trying to I'm +trying to write it and I'm trying to get + + align:start position:0% +trying to write it and I'm trying to get + + + align:start position:0% +trying to write it and I'm trying to get +this K I want to write something I want + + align:start position:0% +this K I want to write something I want + + + align:start position:0% +this K I want to write something I want +to minimize some quantity and discover + + align:start position:0% +to minimize some quantity and discover + + + align:start position:0% +to minimize some quantity and discover +the K that is going to give me my best + + align:start position:0% +the K that is going to give me my best + + + align:start position:0% +the K that is going to give me my best +case in the worst case okay minimize the + + align:start position:0% +case in the worst case okay minimize the + + + align:start position:0% +case in the worst case okay minimize the +worst case right so that's that's really + + align:start position:0% +worst case right so that's that's really + + + align:start position:0% +worst case right so that's that's really +what I want so so if you look at what + + align:start position:0% +what I want so so if you look at what + + + align:start position:0% +what I want so so if you look at what +what happens here you're you're in a + + align:start position:0% +what happens here you're you're in a + + + align:start position:0% +what happens here you're you're in a +situation where you have to now you have + + align:start position:0% +situation where you have to now you have + + + align:start position:0% +situation where you have to now you have +to count right I mean what do you want + + align:start position:0% +to count right I mean what do you want + + + align:start position:0% +to count right I mean what do you want +to I decided that that K is this general + + align:start position:0% +to I decided that that K is this general + + + align:start position:0% +to I decided that that K is this general +strategy and we don't quite know what K + + align:start position:0% +strategy and we don't quite know what K + + + align:start position:0% +strategy and we don't quite know what K +is and we have to do some analysis of + + align:start position:0% +is and we have to do some analysis of + + + align:start position:0% +is and we have to do some analysis of +the worst-case situation in order to + + align:start position:0% +the worst-case situation in order to + + + align:start position:0% +the worst-case situation in order to +find the K that would work well for us + + align:start position:0% +find the K that would work well for us + + + align:start position:0% +find the K that would work well for us +and so the way you do this is by + + align:start position:0% +and so the way you do this is by + + + align:start position:0% +and so the way you do this is by +essentially the analysis we've done so + + align:start position:0% +essentially the analysis we've done so + + + align:start position:0% +essentially the analysis we've done so +far and + + align:start position:0% +far and + + + align:start position:0% +far and +kind of we have a nice the the the point + + align:start position:0% +kind of we have a nice the the the point + + + align:start position:0% +kind of we have a nice the the the point +that was made here I think was it was + + align:start position:0% +that was made here I think was it was + + + align:start position:0% +that was made here I think was it was +Kevin who said we have to go to the last + + align:start position:0% +Kevin who said we have to go to the last + + + align:start position:0% +Kevin who said we have to go to the last +drop because that's kind of the the case + + align:start position:0% +drop because that's kind of the the case + + + align:start position:0% +drop because that's kind of the the case +where I it's the worst case and that's + + align:start position:0% +where I it's the worst case and that's + + + align:start position:0% +where I it's the worst case and that's +similar here as well because if you go + + align:start position:0% +similar here as well because if you go + + + align:start position:0% +similar here as well because if you go +up all the way here and then it breaks + + align:start position:0% +up all the way here and then it breaks + + + align:start position:0% +up all the way here and then it breaks +if it doesn't break here you're done + + align:start position:0% +if it doesn't break here you're done + + + align:start position:0% +if it doesn't break here you're done +if it breaks here then you've got you've + + align:start position:0% +if it breaks here then you've got you've + + + align:start position:0% +if it breaks here then you've got you've +done a lot of drops before it broke that + + align:start position:0% +done a lot of drops before it broke that + + + align:start position:0% +done a lot of drops before it broke that +first ball and so that's at the + + align:start position:0% +first ball and so that's at the + + + align:start position:0% +first ball and so that's at the +situation which you can pull them as + + align:start position:0% +situation which you can pull them as + + + align:start position:0% +situation which you can pull them as +your worst case situation right so + + align:start position:0% +your worst case situation right so + + + align:start position:0% +your worst case situation right so +that's exactly what we did before and so + + align:start position:0% +that's exactly what we did before and so + + + align:start position:0% +that's exactly what we did before and so +so if you really think about it the + + align:start position:0% +so if you really think about it the + + + align:start position:0% +so if you really think about it the +assumed first ball doesn't break till + + align:start position:0% +assumed first ball doesn't break till + + + align:start position:0% +assumed first ball doesn't break till +the last draw is the is the worst-case + + align:start position:0% +the last draw is the is the worst-case + + + align:start position:0% +the last draw is the is the worst-case +situation right and so what does that + + align:start position:0% +situation right and so what does that + + + align:start position:0% +situation right and so what does that +mean + + align:start position:0% +mean + + + align:start position:0% +mean +from a symbolic standpoint with respect + + align:start position:0% +from a symbolic standpoint with respect + + + align:start position:0% +from a symbolic standpoint with respect +to the number of drops of so so the + + align:start position:0% +to the number of drops of so so the + + + align:start position:0% +to the number of drops of so so the +number of drops in this case of the + + align:start position:0% +number of drops in this case of the + + + align:start position:0% +number of drops in this case of the +first ball can someone give me an + + align:start position:0% +first ball can someone give me an + + + align:start position:0% +first ball can someone give me an +equation for it yeah okay you're Kevin - + + align:start position:0% +equation for it yeah okay you're Kevin - + + + align:start position:0% +equation for it yeah okay you're Kevin - +yeah okay so so n over K right so so + + align:start position:0% +yeah okay so so n over K right so so + + + align:start position:0% +yeah okay so so n over K right so so +that's the that's what happened there + + align:start position:0% +that's the that's what happened there + + + align:start position:0% +that's the that's what happened there +now well it broke right that's what we + + align:start position:0% +now well it broke right that's what we + + + align:start position:0% +now well it broke right that's what we +decided here and so now you need to + + align:start position:0% +decided here and so now you need to + + + align:start position:0% +decided here and so now you need to +search and K plus 1 right + + align:start position:0% + + + + align:start position:0% + +- I bet you got to go all the way there + + align:start position:0% +- I bet you got to go all the way there + + + align:start position:0% +- I bet you got to go all the way there +I'm sorry it broke there so you got to + + align:start position:0% +I'm sorry it broke there so you got to + + + align:start position:0% +I'm sorry it broke there so you got to +go n minus 1 is the same as what I wrote + + align:start position:0% +go n minus 1 is the same as what I wrote + + + align:start position:0% +go n minus 1 is the same as what I wrote +before in but it's just that I had + + align:start position:0% +before in but it's just that I had + + + align:start position:0% +before in but it's just that I had +numbers and it was kind of easier to + + align:start position:0% +numbers and it was kind of easier to + + + align:start position:0% +numbers and it was kind of easier to +write numbers then write these symbols + + align:start position:0% +write numbers then write these symbols + + + align:start position:0% +write numbers then write these symbols +but we have to do this because we don't + + align:start position:0% +but we have to do this because we don't + + + align:start position:0% +but we have to do this because we don't +know what K is okay so the if you look + + align:start position:0% +know what K is okay so the if you look + + + align:start position:0% +know what K is okay so the if you look +at the how many + + align:start position:0% +at the how many + + + align:start position:0% +at the how many +drops are and if you guys can do this + + align:start position:0% +drops are and if you guys can do this + + + align:start position:0% +drops are and if you guys can do this +you get a if you notice this gets + + align:start position:0% +you get a if you notice this gets + + + align:start position:0% +you get a if you notice this gets +simplified to and yeah so this is n then + + align:start position:0% +simplified to and yeah so this is n then + + + align:start position:0% +simplified to and yeah so this is n then +you have minus k plus 1 all the way to n + + align:start position:0% +you have minus k plus 1 all the way to n + + + align:start position:0% +you have minus k plus 1 all the way to n +minus 1 right so if you subtract and + + align:start position:0% +minus 1 right so if you subtract and + + + align:start position:0% +minus 1 right so if you subtract and +this is a plus 1 here boy + + align:start position:0% +this is a plus 1 here boy + + + align:start position:0% +this is a plus 1 here boy +this is confusing I'm not good at math + + align:start position:0% +this is confusing I'm not good at math + + + align:start position:0% +this is confusing I'm not good at math +I'm definitely not good at math so this + + align:start position:0% +I'm definitely not good at math so this + + + align:start position:0% +I'm definitely not good at math so this +is K minus 1 drops in the worst case + + align:start position:0% +is K minus 1 drops in the worst case + + + align:start position:0% +is K minus 1 drops in the worst case +alright so you now need to add these two + + align:start position:0% +alright so you now need to add these two + + + align:start position:0% +alright so you now need to add these two +things together so what we'd like to do + + align:start position:0% +things together so what we'd like to do + + + align:start position:0% +things together so what we'd like to do +is minimize and my n divided by K which + + align:start position:0% +is minimize and my n divided by K which + + + align:start position:0% +is minimize and my n divided by K which +is this Plus that right we want to + + align:start position:0% +is this Plus that right we want to + + + align:start position:0% +is this Plus that right we want to +minimize this function right n its + + align:start position:0% +minimize this function right n its + + + align:start position:0% +minimize this function right n its +constant K is a variable right and we + + align:start position:0% +constant K is a variable right and we + + + align:start position:0% +constant K is a variable right and we +know for a given n we want to discover + + align:start position:0% +know for a given n we want to discover + + + align:start position:0% +know for a given n we want to discover +the K that minimizes this quantity and + + align:start position:0% +the K that minimizes this quantity and + + + align:start position:0% +the K that minimizes this quantity and +it goes back to the intuition that that + + align:start position:0% +it goes back to the intuition that that + + + align:start position:0% +it goes back to the intuition that that +I think Josh had about the square root + + align:start position:0% +I think Josh had about the square root + + + align:start position:0% +I think Josh had about the square root +of n right + + align:start position:0% +of n right + + + align:start position:0% +of n right +so again high school calculus here which + + align:start position:0% +so again high school calculus here which + + + align:start position:0% +so again high school calculus here which +I've forgotten is hopefully you haven't + + align:start position:0% +I've forgotten is hopefully you haven't + + + align:start position:0% +I've forgotten is hopefully you haven't +because you still need it I don't and + + align:start position:0% +because you still need it I don't and + + + align:start position:0% +because you still need it I don't and +you end up essentially saying you can + + align:start position:0% +you end up essentially saying you can + + + align:start position:0% +you end up essentially saying you can +turn this into 2 raised to square root + + align:start position:0% +turn this into 2 raised to square root + + + align:start position:0% +turn this into 2 raised to square root +of n minus 1 drops in the worst case all + + align:start position:0% +of n minus 1 drops in the worst case all + + + align:start position:0% +of n minus 1 drops in the worst case all +right + + align:start position:0% +right + + + align:start position:0% +right +so 4 so you can take that the floor of + + align:start position:0% +so 4 so you can take that the floor of + + + align:start position:0% +so 4 so you can take that the floor of +that and that's that's 11 okay so so + + align:start position:0% +that and that's that's 11 okay so so + + + align:start position:0% +that and that's that's 11 okay so so +that's the square root of n so 2 times + + align:start position:0% +that's the square root of n so 2 times + + + align:start position:0% +that's the square root of n so 2 times +11 minus 1 is 21 so you can do 21 + + align:start position:0% +11 minus 1 is 21 so you can do 21 + + + align:start position:0% +11 minus 1 is 21 so you can do 21 +so you think 21 is the optimum yeah + + align:start position:0% + + + + align:start position:0% + +yes yes you can you can do a little bit + + align:start position:0% +yes yes you can you can do a little bit + + + align:start position:0% +yes yes you can you can do a little bit +better I don't want to do this yes yet + + align:start position:0% +better I don't want to do this yes yet + + + align:start position:0% +better I don't want to do this yes yet +hopefully we'll have time we'll get to + + align:start position:0% +hopefully we'll have time we'll get to + + + align:start position:0% +hopefully we'll have time we'll get to +that because I want to go to the the D + + align:start position:0% +that because I want to go to the the D + + + align:start position:0% +that because I want to go to the the D +greater than two case but you're + + align:start position:0% +greater than two case but you're + + + align:start position:0% +greater than two case but you're +absolutely right it turns out you can do + + align:start position:0% +absolutely right it turns out you can do + + + align:start position:0% +absolutely right it turns out you can do +this would this would give you 21 as I + + align:start position:0% +this would this would give you 21 as I + + + align:start position:0% +this would this would give you 21 as I +mentioned at 22 minus one I tell thought + + align:start position:0% +mentioned at 22 minus one I tell thought + + + align:start position:0% +mentioned at 22 minus one I tell thought +you can do better by a few drops and the + + align:start position:0% +you can do better by a few drops and the + + + align:start position:0% +you can do better by a few drops and the +assumption we made here + + align:start position:0% +assumption we made here + + + align:start position:0% +assumption we made here +what is the assumption that we made here + + align:start position:0% +what is the assumption that we made here + + + align:start position:0% +what is the assumption that we made here +but I wrote this what assumption did I + + align:start position:0% +but I wrote this what assumption did I + + + align:start position:0% +but I wrote this what assumption did I +make which is kind of similar to what + + align:start position:0% +make which is kind of similar to what + + + align:start position:0% +make which is kind of similar to what +Kevin just said but not exactly right + + align:start position:0% +Kevin just said but not exactly right + + + align:start position:0% +Kevin just said but not exactly right +but someone point out the assumption + + align:start position:0% +but someone point out the assumption + + + align:start position:0% +but someone point out the assumption +that was made here not you someone else + + align:start position:0% + + + + align:start position:0% + +all right go for it + + align:start position:0% +all right go for it + + + align:start position:0% +all right go for it +yeah the intervals are equal right so so + + align:start position:0% +yeah the intervals are equal right so so + + + align:start position:0% +yeah the intervals are equal right so so +so I this look it's it's a different + + align:start position:0% +so I this look it's it's a different + + + align:start position:0% +so I this look it's it's a different +problem if it didn't break here then I + + align:start position:0% +problem if it didn't break here then I + + + align:start position:0% +problem if it didn't break here then I +got a smaller I have two balls and I had + + align:start position:0% +got a smaller I have two balls and I had + + + align:start position:0% +got a smaller I have two balls and I had +a smaller problem so why would I use the + + align:start position:0% +a smaller problem so why would I use the + + + align:start position:0% +a smaller problem so why would I use the +same K right I mean that kind of makes + + align:start position:0% +same K right I mean that kind of makes + + + align:start position:0% +same K right I mean that kind of makes +sense right so now it's more complicated + + align:start position:0% +sense right so now it's more complicated + + + align:start position:0% +sense right so now it's more complicated +and I hopefully will get to that but I + + align:start position:0% +and I hopefully will get to that but I + + + align:start position:0% +and I hopefully will get to that but I +want to do other things first + + align:start position:0% +want to do other things first + + + align:start position:0% +want to do other things first +so that's the reason so at least you + + align:start position:0% +so that's the reason so at least you + + + align:start position:0% +so that's the reason so at least you +know why 21 isn't optimal right it's + + align:start position:0% +know why 21 isn't optimal right it's + + + align:start position:0% +know why 21 isn't optimal right it's +because of this constraint that we + + align:start position:0% +because of this constraint that we + + + align:start position:0% +because of this constraint that we +placed on ourselves in order to do this + + align:start position:0% +placed on ourselves in order to do this + + + align:start position:0% +placed on ourselves in order to do this +analysis to get to the point where we + + align:start position:0% +analysis to get to the point where we + + + align:start position:0% +analysis to get to the point where we +had two times square root of n minus one + + align:start position:0% +had two times square root of n minus one + + + align:start position:0% +had two times square root of n minus one +that that corresponds to the equally + + align:start position:0% +that that corresponds to the equally + + + align:start position:0% +that that corresponds to the equally +level constraint okay all right so good + + align:start position:0% +level constraint okay all right so good + + + align:start position:0% +level constraint okay all right so good +all right any questions about this so as + + align:start position:0% +all right any questions about this so as + + + align:start position:0% +all right any questions about this so as +you can imagine I'm not going to show + + align:start position:0% +you can imagine I'm not going to show + + + align:start position:0% +you can imagine I'm not going to show +you code that computes two times square + + align:start position:0% +you code that computes two times square + + + align:start position:0% +you code that computes two times square +root of n minus 1 right I said that that + + align:start position:0% +root of n minus 1 right I said that that + + + align:start position:0% +root of n minus 1 right I said that that +doesn't make sense but we do have code + + align:start position:0% +doesn't make sense but we do have code + + + align:start position:0% +doesn't make sense but we do have code +to look at that corresponds to at the + + align:start position:0% +to look at that corresponds to at the + + + align:start position:0% +to look at that corresponds to at the +case where a D could be 3 D could be 4 + + align:start position:0% +case where a D could be 3 D could be 4 + + + align:start position:0% +case where a D could be 3 D could be 4 +and and then obviously it gets more + + align:start position:0% +and and then obviously it gets more + + + align:start position:0% +and and then obviously it gets more +interesting in terms of what your + + align:start position:0% +interesting in terms of what your + + + align:start position:0% +interesting in terms of what your +strategy is and we won't go with + + align:start position:0% +strategy is and we won't go with + + + align:start position:0% +strategy is and we won't go with +optimizing in fact it's an open problem + + align:start position:0% +optimizing in fact it's an open problem + + + align:start position:0% +optimizing in fact it's an open problem +as to what the optimum strategy would be + + align:start position:0% +as to what the optimum strategy would be + + + align:start position:0% +as to what the optimum strategy would be +for arbitrary D in the D meaning the + + align:start position:0% +for arbitrary D in the D meaning the + + + align:start position:0% +for arbitrary D in the D meaning the +number of balls if it's 5 6 whatever + + align:start position:0% +number of balls if it's 5 6 whatever + + + align:start position:0% +number of balls if it's 5 6 whatever +partly because of what I just talked + + align:start position:0% +partly because of what I just talked + + + align:start position:0% +partly because of what I just talked +about with respect to you need to + + align:start position:0% +about with respect to you need to + + + align:start position:0% +about with respect to you need to +utilize unequal intervals but the + + align:start position:0% +utilize unequal intervals but the + + + align:start position:0% +utilize unequal intervals but the +natural thing to do now is to move to D + + align:start position:0% +natural thing to do now is to move to D + + + align:start position:0% +natural thing to do now is to move to D +equals arbitrary number of balls and + + align:start position:0% +equals arbitrary number of balls and + + + align:start position:0% +equals arbitrary number of balls and +stick with kind of the same algorithmic + + align:start position:0% +stick with kind of the same algorithmic + + + align:start position:0% +stick with kind of the same algorithmic +approach of having equal intervals right + + align:start position:0% +approach of having equal intervals right + + + align:start position:0% +approach of having equal intervals right +and but the question is you know what + + align:start position:0% +and but the question is you know what + + + align:start position:0% +and but the question is you know what +are these intervals what and how would + + align:start position:0% +are these intervals what and how would + + + align:start position:0% +are these intervals what and how would +we find the size of these intervals + + align:start position:0% +we find the size of these intervals + + + align:start position:0% +we find the size of these intervals +right because it's kind of not + + align:start position:0% +right because it's kind of not + + + align:start position:0% +right because it's kind of not +immediately obvious if I told you D was + + align:start position:0% +immediately obvious if I told you D was + + + align:start position:0% +immediately obvious if I told you D was +5 and you don't want to just keep the 3 + + align:start position:0% +5 and you don't want to just keep the 3 + + + align:start position:0% +5 and you don't want to just keep the 3 +balls away and you know sell them later + + align:start position:0% +balls away and you know sell them later + + + align:start position:0% +balls away and you know sell them later +and just use the 2 right that doesn't + + align:start position:0% +and just use the 2 right that doesn't + + + align:start position:0% +and just use the 2 right that doesn't +give you your minimum doesn't minimize + + align:start position:0% +give you your minimum doesn't minimize + + + align:start position:0% +give you your minimum doesn't minimize +your worst case you want to use these + + align:start position:0% +your worst case you want to use these + + + align:start position:0% +your worst case you want to use these +you use these balls cool all right so + + align:start position:0% +you use these balls cool all right so + + + align:start position:0% +you use these balls cool all right so +let's + + align:start position:0% +let's + + + align:start position:0% +let's +let's talk a little bit about if I had d + + align:start position:0% +let's talk a little bit about if I had d + + + align:start position:0% +let's talk a little bit about if I had d +equals 3 I mean again gonna use your + + align:start position:0% +equals 3 I mean again gonna use your + + + align:start position:0% +equals 3 I mean again gonna use your +intuition what do you think we should do + + align:start position:0% +intuition what do you think we should do + + + align:start position:0% +intuition what do you think we should do +what happened for D equals 2 with + + align:start position:0% +what happened for D equals 2 with + + + align:start position:0% +what happened for D equals 2 with +respect to that interval and how is it + + align:start position:0% +respect to that interval and how is it + + + align:start position:0% +respect to that interval and how is it +related to n right so what do you think + + align:start position:0% +related to n right so what do you think + + + align:start position:0% +related to n right so what do you think +I just wild guess maybe even what do you + + align:start position:0% +I just wild guess maybe even what do you + + + align:start position:0% +I just wild guess maybe even what do you +think we need to do if he had d equals 3 + + align:start position:0% +think we need to do if he had d equals 3 + + + align:start position:0% +think we need to do if he had d equals 3 +for that very first ball in terms of + + align:start position:0% +for that very first ball in terms of + + + align:start position:0% +for that very first ball in terms of +what we need to look at in relation to + + align:start position:0% +what we need to look at in relation to + + + align:start position:0% +what we need to look at in relation to +the interval sighs yeah back there + + align:start position:0% +the interval sighs yeah back there + + + align:start position:0% +the interval sighs yeah back there +ah-ha cube root cube root what what's + + align:start position:0% +ah-ha cube root cube root what what's + + + align:start position:0% +ah-ha cube root cube root what what's +your name Ryan so Ryan says you know + + align:start position:0% +your name Ryan so Ryan says you know + + + align:start position:0% +your name Ryan so Ryan says you know +cube root and yeah that that's the + + align:start position:0% +cube root and yeah that that's the + + + align:start position:0% +cube root and yeah that that's the +correct intuition it's a little bit + + align:start position:0% +correct intuition it's a little bit + + + align:start position:0% +correct intuition it's a little bit +unclear you know what happens you know + + align:start position:0% +unclear you know what happens you know + + + align:start position:0% +unclear you know what happens you know +so they do cube roots and maybe you have + + align:start position:0% +so they do cube roots and maybe you have + + + align:start position:0% +so they do cube roots and maybe you have +you know what's the cube root of 128 5 + + align:start position:0% +you know what's the cube root of 128 5 + + + align:start position:0% +you know what's the cube root of 128 5 +you know yeah that's right I think it's + + align:start position:0% +you know yeah that's right I think it's + + + align:start position:0% +you know yeah that's right I think it's +5 ok it's close to 5 you know it's it's + + align:start position:0% +5 ok it's close to 5 you know it's it's + + + align:start position:0% +5 ok it's close to 5 you know it's it's +say six or five or six right and and so + + align:start position:0% +say six or five or six right and and so + + + align:start position:0% +say six or five or six right and and so +maybe I do six and then I do 12 and it's + + align:start position:0% +maybe I do six and then I do 12 and it's + + + align:start position:0% +maybe I do six and then I do 12 and it's +that is it's a little bit strange so it + + align:start position:0% +that is it's a little bit strange so it + + + align:start position:0% +that is it's a little bit strange so it +turns out it's actually the six in 12 + + align:start position:0% +turns out it's actually the six in 12 + + + align:start position:0% +turns out it's actually the six in 12 +when you start with 128 when you have + + align:start position:0% +when you start with 128 when you have + + + align:start position:0% +when you start with 128 when you have +three balls doesn't seem like it's gonna + + align:start position:0% +three balls doesn't seem like it's gonna + + + align:start position:0% +three balls doesn't seem like it's gonna +give you the worst case right right + + align:start position:0% +give you the worst case right right + + + align:start position:0% +give you the worst case right right +because you know like in the worst case + + align:start position:0% +because you know like in the worst case + + + align:start position:0% +because you know like in the worst case +you might be dropping the ball six 12 18 + + align:start position:0% +you might be dropping the ball six 12 18 + + + align:start position:0% +you might be dropping the ball six 12 18 +24 etcetera etcetera right um so cube + + align:start position:0% +24 etcetera etcetera right um so cube + + + align:start position:0% +24 etcetera etcetera right um so cube +root is right but it's something a + + align:start position:0% +root is right but it's something a + + + align:start position:0% +root is right but it's something a +little bit different because it gave us + + align:start position:0% +little bit different because it gave us + + + align:start position:0% +little bit different because it gave us +this interval that was kind of too small + + align:start position:0% +this interval that was kind of too small + + + align:start position:0% +this interval that was kind of too small +so how would I get something that's + + align:start position:0% +so how would I get something that's + + + align:start position:0% +so how would I get something that's +bigger you'd want things that are a + + align:start position:0% +bigger you'd want things that are a + + + align:start position:0% +bigger you'd want things that are a +little bit bigger right I mean yeah I + + align:start position:0% +little bit bigger right I mean yeah I + + + align:start position:0% +little bit bigger right I mean yeah I +think you're going to the right + + align:start position:0% +think you're going to the right + + + align:start position:0% +think you're going to the right +direction but I don't want six and + + align:start position:0% +direction but I don't want six and + + + align:start position:0% +direction but I don't want six and +twelve and eighteen + + align:start position:0% +twelve and eighteen + + + align:start position:0% +twelve and eighteen +I mean clearly that's going to give me + + align:start position:0% +I mean clearly that's going to give me + + + align:start position:0% +I mean clearly that's going to give me +like 25 drops and that's even worse than + + align:start position:0% +like 25 drops and that's even worse than + + + align:start position:0% +like 25 drops and that's even worse than +then then the two ball case which really + + align:start position:0% +then then the two ball case which really + + + align:start position:0% +then then the two ball case which really +means you should lose your job and never + + align:start position:0% +means you should lose your job and never + + + align:start position:0% +means you should lose your job and never +get another one right so if you do + + align:start position:0% +get another one right so if you do + + + align:start position:0% +get another one right so if you do +something that bad right so so that + + align:start position:0% +something that bad right so so that + + + align:start position:0% +something that bad right so so that +that's up to what what would you do + + align:start position:0% +that's up to what what would you do + + + align:start position:0% +that's up to what what would you do +that's you know kind of different from + + align:start position:0% +that's you know kind of different from + + + align:start position:0% +that's you know kind of different from +cube root but related to cube root right + + align:start position:0% +cube root but related to cube root right + + + align:start position:0% +cube root but related to cube root right +yeah go ahead fun + + align:start position:0% +yeah go ahead fun + + + align:start position:0% +yeah go ahead fun +yeah so what you want to do is you want + + align:start position:0% +yeah so what you want to do is you want + + + align:start position:0% +yeah so what you want to do is you want +to start it makes sense that when you + + align:start position:0% +to start it makes sense that when you + + + align:start position:0% +to start it makes sense that when you +have lots of balls in terms of being + + align:start position:0% +have lots of balls in terms of being + + + align:start position:0% +have lots of balls in terms of being +able to use them that you start with + + align:start position:0% +able to use them that you start with + + + align:start position:0% +able to use them that you start with +larger intervals and you shrink them + + align:start position:0% +larger intervals and you shrink them + + + align:start position:0% +larger intervals and you shrink them +right that's exactly what happened with + + align:start position:0% +right that's exactly what happened with + + + align:start position:0% +right that's exactly what happened with +two balls + + align:start position:0% +two balls + + + align:start position:0% +two balls +you started with K I in in the case + + align:start position:0% +you started with K I in in the case + + + align:start position:0% +you started with K I in in the case +where we had two balls and then we're + + align:start position:0% +where we had two balls and then we're + + + align:start position:0% +where we had two balls and then we're +down to one when we have one ball right + + align:start position:0% +down to one when we have one ball right + + + align:start position:0% +down to one when we have one ball right +so that's really what you're doing when + + align:start position:0% +so that's really what you're doing when + + + align:start position:0% +so that's really what you're doing when +you have one ball all you can do is go + + align:start position:0% +you have one ball all you can do is go + + + align:start position:0% +you have one ball all you can do is go +one floor at a time when you have when + + align:start position:0% +one floor at a time when you have when + + + align:start position:0% +one floor at a time when you have when +you have two balls you go K where K + + align:start position:0% +you have two balls you go K where K + + + align:start position:0% +you have two balls you go K where K +happened to be square root of n and then + + align:start position:0% +happened to be square root of n and then + + + align:start position:0% +happened to be square root of n and then +we had three balls you kind of want to + + align:start position:0% +we had three balls you kind of want to + + + align:start position:0% +we had three balls you kind of want to +start with with like n raised to 2/3 in + + align:start position:0% +start with with like n raised to 2/3 in + + + align:start position:0% +start with with like n raised to 2/3 in +terms of the in terms of the interval + + align:start position:0% +terms of the in terms of the interval + + + align:start position:0% +terms of the in terms of the interval +right and then if I had four balls the + + align:start position:0% +right and then if I had four balls the + + + align:start position:0% +right and then if I had four balls the +argument would be that I would start + + align:start position:0% +argument would be that I would start + + + align:start position:0% +argument would be that I would start +with n raised to three three quarters + + align:start position:0% +with n raised to three three quarters + + + align:start position:0% +with n raised to three three quarters +and then I'll go to square root of N and + + align:start position:0% +and then I'll go to square root of N and + + + align:start position:0% +and then I'll go to square root of N and +then I'll go so on and so forth and what + + align:start position:0% +then I'll go so on and so forth and what + + + align:start position:0% +then I'll go so on and so forth and what +is that reminding you of well what is + + align:start position:0% +is that reminding you of well what is + + + align:start position:0% +is that reminding you of well what is +what is this in terms of these powers + + align:start position:0% +what is this in terms of these powers + + + align:start position:0% +what is this in terms of these powers +and you know getting up to not quite n + + align:start position:0% +and you know getting up to not quite n + + + align:start position:0% +and you know getting up to not quite n +but five six N and so on what is that + + align:start position:0% +but five six N and so on what is that + + + align:start position:0% +but five six N and so on what is that +reminding you of from number number + + align:start position:0% +reminding you of from number number + + + align:start position:0% +reminding you of from number number +theory or just sort of regular + + align:start position:0% +theory or just sort of regular + + + align:start position:0% +theory or just sort of regular +arithmetic yeah different bases it's + + align:start position:0% +arithmetic yeah different bases it's + + + align:start position:0% +arithmetic yeah different bases it's +different different radix arithmetic + + align:start position:0% +different different radix arithmetic + + + align:start position:0% +different different radix arithmetic +right so it turns out the way you want + + align:start position:0% +right so it turns out the way you want + + + align:start position:0% +right so it turns out the way you want +to solve this problem and and this is in + + align:start position:0% +to solve this problem and and this is in + + + align:start position:0% +to solve this problem and and this is in +keeping with the intuition you have you + + align:start position:0% +keeping with the intuition you have you + + + align:start position:0% +keeping with the intuition you have you +you have with respect to the cube roots + + align:start position:0% +you have with respect to the cube roots + + + align:start position:0% +you have with respect to the cube roots +and so on and so forth the way we want + + align:start position:0% +and so on and so forth the way we want + + + align:start position:0% +and so on and so forth the way we want +to do this is we want to think about D + + align:start position:0% +to do this is we want to think about D + + + align:start position:0% +to do this is we want to think about D +digit numbers and at the numbers + + align:start position:0% +digit numbers and at the numbers + + + align:start position:0% +digit numbers and at the numbers +themselves and D is the number of balls + + align:start position:0% + + + + align:start position:0% + +and so that's that D digits but what + + align:start position:0% +and so that's that D digits but what + + + align:start position:0% +and so that's that D digits but what +what is the Vedic sub these numbers okay + + align:start position:0% +what is the Vedic sub these numbers okay + + + align:start position:0% +what is the Vedic sub these numbers okay +the the radix of these numbers are going + + align:start position:0% +the the radix of these numbers are going + + + align:start position:0% +the the radix of these numbers are going +to be related to that to the K to the + + align:start position:0% +to be related to that to the K to the + + + align:start position:0% +to be related to that to the K to the +intervals right so you you you + + align:start position:0% +intervals right so you you you + + + align:start position:0% +intervals right so you you you +essentially want to say you know I'm + + align:start position:0% +essentially want to say you know I'm + + + align:start position:0% +essentially want to say you know I'm +counting in multiples of K right you + + align:start position:0% +counting in multiples of K right you + + + align:start position:0% +counting in multiples of K right you +know I went K 2 K 3 K etcetera so if I + + align:start position:0% +know I went K 2 K 3 K etcetera so if I + + + align:start position:0% +know I went K 2 K 3 K etcetera so if I +had like radix K that means I'm just + + align:start position:0% +had like radix K that means I'm just + + + align:start position:0% +had like radix K that means I'm just +incrementing that particular particular + + align:start position:0% +incrementing that particular particular + + + align:start position:0% +incrementing that particular particular +digit right you know 5 if I go if I had + + align:start position:0% +digit right you know 5 if I go if I had + + + align:start position:0% +digit right you know 5 if I go if I had +radix 12 and + + align:start position:0% +radix 12 and + + + align:start position:0% +radix 12 and +and I had one zero in radix 12 right + + align:start position:0% +and I had one zero in radix 12 right + + + align:start position:0% +and I had one zero in radix 12 right +then you know this this this would be so + + align:start position:0% +then you know this this this would be so + + + align:start position:0% +then you know this this this would be so +when I go to zero then at the the most + + align:start position:0% +when I go to zero then at the the most + + + align:start position:0% +when I go to zero then at the the most +significant digit + + align:start position:0% +significant digit + + + align:start position:0% +significant digit +I got incremented and so this this is + + align:start position:0% +I got incremented and so this this is + + + align:start position:0% +I got incremented and so this this is +plus 12 this is 12 times larger I'm + + align:start position:0% +plus 12 this is 12 times larger I'm + + + align:start position:0% +plus 12 this is 12 times larger I'm +sorry + + align:start position:0% +sorry + + + align:start position:0% +sorry +12 larger then 2 0 is 12 larger than 1 0 + + align:start position:0% +12 larger then 2 0 is 12 larger than 1 0 + + + align:start position:0% +12 larger then 2 0 is 12 larger than 1 0 +in in in radix 12 right make sense just + + align:start position:0% +in in in radix 12 right make sense just + + + align:start position:0% +in in in radix 12 right make sense just +like 20 is 10 larger than 10 10 in in + + align:start position:0% +like 20 is 10 larger than 10 10 in in + + + align:start position:0% +like 20 is 10 larger than 10 10 in in +decimal right so so that's that's the + + align:start position:0% +decimal right so so that's that's the + + + align:start position:0% +decimal right so so that's that's the +way you want to think about this and so + + align:start position:0% +way you want to think about this and so + + + align:start position:0% +way you want to think about this and so +I you're gonna do our Airy numbers and + + align:start position:0% +I you're gonna do our Airy numbers and + + + align:start position:0% +I you're gonna do our Airy numbers and +the first thing that you need to do is + + align:start position:0% +the first thing that you need to do is + + + align:start position:0% +the first thing that you need to do is +you need to figure out based on the + + align:start position:0% +you need to figure out based on the + + + align:start position:0% +you need to figure out based on the +number of floors that you have figure + + align:start position:0% +number of floors that you have figure + + + align:start position:0% +number of floors that you have figure +out your given D you're given n the + + align:start position:0% +out your given D you're given n the + + + align:start position:0% +out your given D you're given n the +number of floors and you're given the + + align:start position:0% +number of floors and you're given the + + + align:start position:0% +number of floors and you're given the +number of balls you got to figure out + + align:start position:0% +number of balls you got to figure out + + + align:start position:0% +number of balls you got to figure out +what radix you're working in and this is + + align:start position:0% +what radix you're working in and this is + + + align:start position:0% +what radix you're working in and this is +going to be a generalization of the + + align:start position:0% +going to be a generalization of the + + + align:start position:0% +going to be a generalization of the +square root of n as you'll see we we + + align:start position:0% +square root of n as you'll see we we + + + align:start position:0% +square root of n as you'll see we we +want to choose the radix such that R + + align:start position:0% +want to choose the radix such that R + + + align:start position:0% +want to choose the radix such that R +raised to D is greater than n I choose R + + align:start position:0% + + + + align:start position:0% + +such that R raised to D is greater than + + align:start position:0% +such that R raised to D is greater than + + + align:start position:0% +such that R raised to D is greater than +n right and so that comes back to + + align:start position:0% +n right and so that comes back to + + + align:start position:0% +n right and so that comes back to +obviously if you need it if D where 2 + + align:start position:0% +obviously if you need it if D where 2 + + + align:start position:0% +obviously if you need it if D where 2 +then it makes sense that our would be + + align:start position:0% +then it makes sense that our would be + + + align:start position:0% +then it makes sense that our would be +square root of M right which is in + + align:start position:0% +square root of M right which is in + + + align:start position:0% +square root of M right which is in +keeping with what we talked about right + + align:start position:0% +keeping with what we talked about right + + + align:start position:0% +keeping with what we talked about right +but if if D is 3 then that radix not + + align:start position:0% +but if if D is 3 then that radix not + + + align:start position:0% +but if if D is 3 then that radix not +necessarily the interval that we choose + + align:start position:0% +necessarily the interval that we choose + + + align:start position:0% +necessarily the interval that we choose +because the intervals are going to be + + align:start position:0% +because the intervals are going to be + + + align:start position:0% +because the intervals are going to be +different it's going to be more like the + + align:start position:0% +different it's going to be more like the + + + align:start position:0% +different it's going to be more like the +cube root of n which is also proposed + + align:start position:0% +cube root of n which is also proposed + + + align:start position:0% +cube root of n which is also proposed +right Brian mentioned that and so so in + + align:start position:0% +right Brian mentioned that and so so in + + + align:start position:0% +right Brian mentioned that and so so in +this case let's say that n were 128 and + + align:start position:0% +this case let's say that n were 128 and + + + align:start position:0% +this case let's say that n were 128 and +D equals 4 then we would choose R equals + + align:start position:0% +D equals 4 then we would choose R equals + + + align:start position:0% +D equals 4 then we would choose R equals +4 because 4 raised to 4 is 256 which is + + align:start position:0% +4 because 4 raised to 4 is 256 which is + + + align:start position:0% +4 because 4 raised to 4 is 256 which is +greater than 128 and we can't use 3 + + align:start position:0% +greater than 128 and we can't use 3 + + + align:start position:0% +greater than 128 and we can't use 3 +because 3 + + align:start position:0% +because 3 + + + align:start position:0% +because 3 +raise to4 is only 81 and 81 isn't + + align:start position:0% +raise to4 is only 81 and 81 isn't + + + align:start position:0% +raise to4 is only 81 and 81 isn't +greater than 128 right so you'd have to + + align:start position:0% +greater than 128 right so you'd have to + + + align:start position:0% +greater than 128 right so you'd have to +choose four so so what we are now saying + + align:start position:0% +choose four so so what we are now saying + + + align:start position:0% +choose four so so what we are now saying +is we want to somehow figure out if + + align:start position:0% +is we want to somehow figure out if + + + align:start position:0% +is we want to somehow figure out if +you're not quite there at an algorithm + + align:start position:0% +you're not quite there at an algorithm + + + align:start position:0% +you're not quite there at an algorithm +yet but we have a kind of a path forward + + align:start position:0% +yet but we have a kind of a path forward + + + align:start position:0% +yet but we have a kind of a path forward +I in that we want to look at the + + align:start position:0% +I in that we want to look at the + + + align:start position:0% +I in that we want to look at the +representation that our airy + + align:start position:0% +representation that our airy + + + align:start position:0% +representation that our airy +representation of these digital numbers + + align:start position:0% +representation of these digital numbers + + + align:start position:0% +representation of these digital numbers +and we're going to essentially I + + align:start position:0% +and we're going to essentially I + + + align:start position:0% +and we're going to essentially I +increment and so with our goal + + align:start position:0% +increment and so with our goal + + + align:start position:0% +increment and so with our goal +roughly speaking we're going to go with + + align:start position:0% +roughly speaking we're going to go with + + + align:start position:0% +roughly speaking we're going to go with +this representation and we're going to + + align:start position:0% +this representation and we're going to + + + align:start position:0% +this representation and we're going to +start incrementing digits so we just go + + align:start position:0% +start incrementing digits so we just go + + + align:start position:0% +start incrementing digits so we just go +0 1 2 in terms of the digits but but + + align:start position:0% +0 1 2 in terms of the digits but but + + + align:start position:0% +0 1 2 in terms of the digits but but +because the representation is our airy + + align:start position:0% +because the representation is our airy + + + align:start position:0% +because the representation is our airy +that means something different in terms + + align:start position:0% +that means something different in terms + + + align:start position:0% +that means something different in terms +of the number of floors depending on + + align:start position:0% +of the number of floors depending on + + + align:start position:0% +of the number of floors depending on +what R is right I mean just like I said + + align:start position:0% +what R is right I mean just like I said + + + align:start position:0% +what R is right I mean just like I said +um if this were if this were ternary a + + align:start position:0% +um if this were if this were ternary a + + + align:start position:0% +um if this were if this were ternary a +ternary representation then then in + + align:start position:0% +ternary representation then then in + + + align:start position:0% +ternary representation then then in +terms of floors this is only you know + + align:start position:0% +terms of floors this is only you know + + + align:start position:0% +terms of floors this is only you know +this would be a 4 ternary this would be + + align:start position:0% +this would be a 4 ternary this would be + + + align:start position:0% +this would be a 4 ternary this would be +3 floors to 0 the in to 0 would be 3 + + align:start position:0% +3 floors to 0 the in to 0 would be 3 + + + align:start position:0% +3 floors to 0 the in to 0 would be 3 +floors away from 1 0 right in decimal to + + align:start position:0% +floors away from 1 0 right in decimal to + + + align:start position:0% +floors away from 1 0 right in decimal to +0 is 10 floors away from 1 0 and so on + + align:start position:0% +0 is 10 floors away from 1 0 and so on + + + align:start position:0% +0 is 10 floors away from 1 0 and so on +and so forth that makes sense yeah ask + + align:start position:0% +and so forth that makes sense yeah ask + + + align:start position:0% +and so forth that makes sense yeah ask +me questions if if you're confused um so + + align:start position:0% +me questions if if you're confused um so + + + align:start position:0% +me questions if if you're confused um so +let's take an example so and then we'll + + align:start position:0% +let's take an example so and then we'll + + + align:start position:0% +let's take an example so and then we'll +we'll look at that we look at code that + + align:start position:0% +we'll look at that we look at code that + + + align:start position:0% +we'll look at that we look at code that +actually builds this algorithm from from + + align:start position:0% +actually builds this algorithm from from + + + align:start position:0% +actually builds this algorithm from from +scratch so if we take our example of D + + align:start position:0% +scratch so if we take our example of D + + + align:start position:0% +scratch so if we take our example of D +equals 4 for our canonical one 28th + + align:start position:0% +equals 4 for our canonical one 28th + + + align:start position:0% +equals 4 for our canonical one 28th +floor Shanghai Tower because you do want + + align:start position:0% +floor Shanghai Tower because you do want + + + align:start position:0% +floor Shanghai Tower because you do want +to get a sense of how things improve we + + align:start position:0% +to get a sense of how things improve we + + + align:start position:0% +to get a sense of how things improve we +did improve from obviously D equals 1 + + align:start position:0% +did improve from obviously D equals 1 + + + align:start position:0% +did improve from obviously D equals 1 +through D equals 2 with the equal + + align:start position:0% +through D equals 2 with the equal + + + align:start position:0% +through D equals 2 with the equal +interval assumption but with this radix + + align:start position:0% +interval assumption but with this radix + + + align:start position:0% +interval assumption but with this radix +idea we'd like to see how much better we + + align:start position:0% +idea we'd like to see how much better we + + + align:start position:0% +idea we'd like to see how much better we +can do right with D equals 4 and we + + align:start position:0% +can do right with D equals 4 and we + + + align:start position:0% +can do right with D equals 4 and we +wanted is substantially better than then + + align:start position:0% +wanted is substantially better than then + + + align:start position:0% +wanted is substantially better than then +21 drops or whatever we had back there + + align:start position:0% +21 drops or whatever we had back there + + + align:start position:0% +21 drops or whatever we had back there +so so R is 4 D is 4 I'm sorry D is 4 + + align:start position:0% +so so R is 4 D is 4 I'm sorry D is 4 + + + align:start position:0% +so so R is 4 D is 4 I'm sorry D is 4 +n equals 128 and what we're going to do + + align:start position:0% +n equals 128 and what we're going to do + + + align:start position:0% +n equals 128 and what we're going to do +is the smallest number is zero zero zero + + align:start position:0% +is the smallest number is zero zero zero + + + align:start position:0% +is the smallest number is zero zero zero +zero and in in brackets I'm gonna write + + align:start position:0% +zero and in in brackets I'm gonna write + + + align:start position:0% +zero and in in brackets I'm gonna write +you know what that decimal + + align:start position:0% +you know what that decimal + + + align:start position:0% +you know what that decimal +representation is because I think that + + align:start position:0% +representation is because I think that + + + align:start position:0% +representation is because I think that +does give you some intuition and you get + + align:start position:0% +does give you some intuition and you get + + + align:start position:0% +does give you some intuition and you get +a sense of how this translates into into + + align:start position:0% +a sense of how this translates into into + + + align:start position:0% +a sense of how this translates into into +floors and after after a while if you're + + align:start position:0% +floors and after after a while if you're + + + align:start position:0% +floors and after after a while if you're +going to tell someone to do this you + + align:start position:0% +going to tell someone to do this you + + + align:start position:0% +going to tell someone to do this you +want to give them floor numbers in + + align:start position:0% +want to give them floor numbers in + + + align:start position:0% +want to give them floor numbers in +decimal because Shangai tower doesn't + + align:start position:0% +decimal because Shangai tower doesn't + + + align:start position:0% +decimal because Shangai tower doesn't +have some weird + + align:start position:0% +have some weird + + + align:start position:0% +have some weird +representation for the floors when you + + align:start position:0% +representation for the floors when you + + + align:start position:0% +representation for the floors when you +get into an elevator or anything like + + align:start position:0% +get into an elevator or anything like + + + align:start position:0% +get into an elevator or anything like +that so so this is floor zero and now + + align:start position:0% +that so so this is floor zero and now + + + align:start position:0% +that so so this is floor zero and now +the highest number is 3 3 3 3 which + + align:start position:0% +the highest number is 3 3 3 3 which + + + align:start position:0% +the highest number is 3 3 3 3 which +happens to be 255 I'm not gonna write + + align:start position:0% +happens to be 255 I'm not gonna write + + + align:start position:0% +happens to be 255 I'm not gonna write +floor each time but when I put things in + + align:start position:0% +floor each time but when I put things in + + + align:start position:0% +floor each time but when I put things in +brackets here that's the decimal + + align:start position:0% +brackets here that's the decimal + + + align:start position:0% +brackets here that's the decimal +representation okay so that's 255 so + + align:start position:0% +representation okay so that's 255 so + + + align:start position:0% +representation okay so that's 255 so +that's obviously too big we don't need + + align:start position:0% +that's obviously too big we don't need + + + align:start position:0% +that's obviously too big we don't need +that but we're stuck with having to + + align:start position:0% +that but we're stuck with having to + + + align:start position:0% +that but we're stuck with having to +choose r equals 4 for the reasons I + + align:start position:0% +choose r equals 4 for the reasons I + + + align:start position:0% +choose r equals 4 for the reasons I +described to you before right so so + + align:start position:0% +described to you before right so so + + + align:start position:0% +described to you before right so so +there's somewhere in here there's a + + align:start position:0% +there's somewhere in here there's a + + + align:start position:0% +there's somewhere in here there's a +there's a 128 and I can't I don't have + + align:start position:0% +there's a 128 and I can't I don't have + + + align:start position:0% +there's a 128 and I can't I don't have +it right up in front of me as to what + + align:start position:0% +it right up in front of me as to what + + + align:start position:0% +it right up in front of me as to what +what 128 would correspond to but 1 2 3 3 + + align:start position:0% +what 128 would correspond to but 1 2 3 3 + + + align:start position:0% +what 128 would correspond to but 1 2 3 3 +for example would be floor 1 1 1 alright + + align:start position:0% +for example would be floor 1 1 1 alright + + + align:start position:0% +for example would be floor 1 1 1 alright +so so the way this works and you all + + align:start position:0% +so so the way this works and you all + + + align:start position:0% +so so the way this works and you all +know you're radix arithmetic it's a 3 + + align:start position:0% +know you're radix arithmetic it's a 3 + + + align:start position:0% +know you're radix arithmetic it's a 3 +times 1 plus 3 3 times 4 plus 2 times 4 + + align:start position:0% +times 1 plus 3 3 times 4 plus 2 times 4 + + + align:start position:0% +times 1 plus 3 3 times 4 plus 2 times 4 +square plus 1 times 4 cubed right that's + + align:start position:0% +square plus 1 times 4 cubed right that's + + + align:start position:0% +square plus 1 times 4 cubed right that's +that's what you have and that's how you + + align:start position:0% +that's what you have and that's how you + + + align:start position:0% +that's what you have and that's how you +get 1 1 1 so all what you have to do in + + align:start position:0% +get 1 1 1 so all what you have to do in + + + align:start position:0% +get 1 1 1 so all what you have to do in +order to do this right is is to start + + align:start position:0% +order to do this right is is to start + + + align:start position:0% +order to do this right is is to start +with the most significant digit which is + + align:start position:0% +with the most significant digit which is + + + align:start position:0% +with the most significant digit which is +the leftmost digit and that makes sense + + align:start position:0% +the leftmost digit and that makes sense + + + align:start position:0% +the leftmost digit and that makes sense +because we want our intervals when we + + align:start position:0% +because we want our intervals when we + + + align:start position:0% +because we want our intervals when we +have lots of balls to be large and that + + align:start position:0% +have lots of balls to be large and that + + + align:start position:0% +have lots of balls to be large and that +as you move and the balls break you're + + align:start position:0% +as you move and the balls break you're + + + align:start position:0% +as you move and the balls break you're +going to start shifting rightward and + + align:start position:0% +going to start shifting rightward and + + + align:start position:0% +going to start shifting rightward and +you're going to be incrementing + + align:start position:0% +you're going to be incrementing + + + align:start position:0% +you're going to be incrementing +different things right and that's + + align:start position:0% +different things right and that's + + + align:start position:0% +different things right and that's +essentially going to give us give us our + + align:start position:0% +essentially going to give us give us our + + + align:start position:0% +essentially going to give us give us our +give us a round with them and so we'll + + align:start position:0% +give us a round with them and so we'll + + + align:start position:0% +give us a round with them and so we'll +talk about let me just give you an + + align:start position:0% +talk about let me just give you an + + + align:start position:0% +talk about let me just give you an +example of the algorithm + + align:start position:0% +example of the algorithm + + + align:start position:0% +example of the algorithm +we'll if you look at we look at how the + + align:start position:0% +we'll if you look at we look at how the + + + align:start position:0% +we'll if you look at we look at how the +algorithm is implemented as I mentioned + + align:start position:0% +algorithm is implemented as I mentioned + + + align:start position:0% +algorithm is implemented as I mentioned +this it turns it into 10 lines of code + + align:start position:0% +this it turns it into 10 lines of code + + + align:start position:0% +this it turns it into 10 lines of code +because all you're doing is translating + + align:start position:0% +because all you're doing is translating + + + align:start position:0% +because all you're doing is translating +into this representation and you're just + + align:start position:0% +into this representation and you're just + + + align:start position:0% +into this representation and you're just +incrementing bits of the representation + + align:start position:0% +incrementing bits of the representation + + + align:start position:0% +incrementing bits of the representation +and it's interactive you can play with + + align:start position:0% +and it's interactive you can play with + + + align:start position:0% +and it's interactive you can play with +it later today or whenever I ate and you + + align:start position:0% +it later today or whenever I ate and you + + + align:start position:0% +it later today or whenever I ate and you +can't think of a hardness coefficients + + align:start position:0% +can't think of a hardness coefficients + + + align:start position:0% +can't think of a hardness coefficients +in your head and see how things work out + + align:start position:0% +in your head and see how things work out + + + align:start position:0% +in your head and see how things work out +but before we end we obviously have to + + align:start position:0% +but before we end we obviously have to + + + align:start position:0% +but before we end we obviously have to +do a worst-case analysis of this of this + + align:start position:0% +do a worst-case analysis of this of this + + + align:start position:0% +do a worst-case analysis of this of this +algorithm because that's the whole point + + align:start position:0% +algorithm because that's the whole point + + + align:start position:0% +algorithm because that's the whole point +of this exercise so let's so so in this + + align:start position:0% +of this exercise so let's so so in this + + + align:start position:0% +of this exercise so let's so so in this +case where do you think I should so I + + align:start position:0% +case where do you think I should so I + + + align:start position:0% +case where do you think I should so I +don't want to drop obviously at floor + + align:start position:0% +don't want to drop obviously at floor + + + align:start position:0% +don't want to drop obviously at floor +zero I mean that there's no notion of + + align:start position:0% +zero I mean that there's no notion of + + + align:start position:0% +zero I mean that there's no notion of +that so very wide drop out at the + + align:start position:0% +that so very wide drop out at the + + + align:start position:0% +that so very wide drop out at the +beginning the first drop is that given + + align:start position:0% +beginning the first drop is that given + + + align:start position:0% +beginning the first drop is that given +what I told you you can tell me in any + + align:start position:0% +what I told you you can tell me in any + + + align:start position:0% +what I told you you can tell me in any +any representation where would I drop + + align:start position:0% +any representation where would I drop + + + align:start position:0% +any representation where would I drop +the first ball if I have four balls at + + align:start position:0% +the first ball if I have four balls at + + + align:start position:0% +the first ball if I have four balls at +128 floors I said I want to start with + + align:start position:0% +128 floors I said I want to start with + + + align:start position:0% +128 floors I said I want to start with +it's something that that obviously + + align:start position:0% +it's something that that obviously + + + align:start position:0% +it's something that that obviously +there's some large interval here and I + + align:start position:0% +there's some large interval here and I + + + align:start position:0% +there's some large interval here and I +want to I I want to start in the left + + align:start position:0% +want to I I want to start in the left + + + align:start position:0% +want to I I want to start in the left +hand side and I want to increment the + + align:start position:0% +hand side and I want to increment the + + + align:start position:0% +hand side and I want to increment the +leftmost bit which is the most + + align:start position:0% +leftmost bit which is the most + + + align:start position:0% +leftmost bit which is the most +significant bit right so I would start + + align:start position:0% +significant bit right so I would start + + + align:start position:0% +significant bit right so I would start +with 1 0 0 0 ok so the first drop is at + + align:start position:0% +with 1 0 0 0 ok so the first drop is at + + + align:start position:0% +with 1 0 0 0 ok so the first drop is at +1 0 0 0 which is at floor 64 ok that's + + align:start position:0% +1 0 0 0 which is at floor 64 ok that's + + + align:start position:0% +1 0 0 0 which is at floor 64 ok that's +the first row now if if in fact on this + + align:start position:0% +the first row now if if in fact on this + + + align:start position:0% +the first row now if if in fact on this +this eye does not break all right so + + align:start position:0% +this eye does not break all right so + + + align:start position:0% +this eye does not break all right so +let's assume that this does not break + + align:start position:0% + + + + align:start position:0% + +then what do I do next + + align:start position:0% +then what do I do next + + + align:start position:0% +then what do I do next +to 0 0 0 right and this would be 128 + + align:start position:0% +to 0 0 0 right and this would be 128 + + + align:start position:0% +to 0 0 0 right and this would be 128 +right ok let's assume that this breaks + + align:start position:0% +right ok let's assume that this breaks + + + align:start position:0% +right ok let's assume that this breaks +here all right + + align:start position:0% +here all right + + + align:start position:0% +here all right +so now what do I do it broke I lost a + + align:start position:0% +so now what do I do it broke I lost a + + + align:start position:0% +so now what do I do it broke I lost a +ball now I have three balls left still + + align:start position:0% +ball now I have three balls left still + + + align:start position:0% +ball now I have three balls left still +that's the good news and harmony so what + + align:start position:0% +that's the good news and harmony so what + + + align:start position:0% +that's the good news and harmony so what +do I need where do I need to move if I + + align:start position:0% +do I need where do I need to move if I + + + align:start position:0% +do I need where do I need to move if I +have 3 balls left I need to be in a + + align:start position:0% +have 3 balls left I need to be in a + + + align:start position:0% +have 3 balls left I need to be in a +representation that has how many + + align:start position:0% +representation that has how many + + + align:start position:0% +representation that has how many +digits three digits right so I need to + + align:start position:0% +digits three digits right so I need to + + + align:start position:0% +digits three digits right so I need to +move III a broker mm so I know that it's + + align:start position:0% +move III a broker mm so I know that it's + + + align:start position:0% +move III a broker mm so I know that it's +less than 2000 so I need to go back to + + align:start position:0% +less than 2000 so I need to go back to + + + align:start position:0% +less than 2000 so I need to go back to +this because this is the this is the + + align:start position:0% +this because this is the this is the + + + align:start position:0% +this because this is the this is the +highest floor in general whenever things + + align:start position:0% +highest floor in general whenever things + + + align:start position:0% +highest floor in general whenever things +break you you go back to the highest + + align:start position:0% +break you you go back to the highest + + + align:start position:0% +break you you go back to the highest +floor that you know that the ball been + + align:start position:0% +floor that you know that the ball been + + + align:start position:0% +floor that you know that the ball been +break right I mean that's the canonical + + align:start position:0% +break right I mean that's the canonical + + + align:start position:0% +break right I mean that's the canonical +strategy that we followed all through + + align:start position:0% +strategy that we followed all through + + + align:start position:0% +strategy that we followed all through +when something when the ball breaks you + + align:start position:0% +when something when the ball breaks you + + + align:start position:0% +when something when the ball breaks you +go back and say oh but I do know that + + align:start position:0% +go back and say oh but I do know that + + + align:start position:0% +go back and say oh but I do know that +there was a highest floor in which the + + align:start position:0% +there was a highest floor in which the + + + align:start position:0% +there was a highest floor in which the +ball did not break and I have to start + + align:start position:0% +ball did not break and I have to start + + + align:start position:0% +ball did not break and I have to start +with one plus that right so so so what + + align:start position:0% +with one plus that right so so so what + + + align:start position:0% +with one plus that right so so so what +I'm going to do here is I need to go up + + align:start position:0% +I'm going to do here is I need to go up + + + align:start position:0% +I'm going to do here is I need to go up +and yeah because it broke I need to look + + align:start position:0% +and yeah because it broke I need to look + + + align:start position:0% +and yeah because it broke I need to look +at one zero zero one + + align:start position:0% +at one zero zero one + + + align:start position:0% +at one zero zero one +right the interval that I need to look + + align:start position:0% +right the interval that I need to look + + + align:start position:0% +right the interval that I need to look +at is 1 0 0 1 right because it's one + + align:start position:0% +at is 1 0 0 1 right because it's one + + + align:start position:0% +at is 1 0 0 1 right because it's one +more than that and all the way to 1 3 3 + + align:start position:0% +more than that and all the way to 1 3 3 + + + align:start position:0% +more than that and all the way to 1 3 3 +3 which is 1 less than that ok so and + + align:start position:0% +3 which is 1 less than that ok so and + + + align:start position:0% +3 which is 1 less than that ok so and +this if this is you may feel a little + + align:start position:0% +this if this is you may feel a little + + + align:start position:0% +this if this is you may feel a little +bit better looking at this in decimal I + + align:start position:0% +bit better looking at this in decimal I + + + align:start position:0% +bit better looking at this in decimal I +certainly do it's 65 127 which makes + + align:start position:0% +certainly do it's 65 127 which makes + + + align:start position:0% +certainly do it's 65 127 which makes +perfect sense so far we've played around + + align:start position:0% +perfect sense so far we've played around + + + align:start position:0% +perfect sense so far we've played around +with with with the balls the first two + + align:start position:0% +with with with the balls the first two + + + align:start position:0% +with with with the balls the first two +balls and so we haven't really seen + + align:start position:0% +balls and so we haven't really seen + + + align:start position:0% +balls and so we haven't really seen +anything very dramatically different + + align:start position:0% +anything very dramatically different + + + align:start position:0% +anything very dramatically different +from the the 2 ball case but more more + + align:start position:0% +from the the 2 ball case but more more + + + align:start position:0% +from the the 2 ball case but more more +is coming right let's say this does not + + align:start position:0% +is coming right let's say this does not + + + align:start position:0% +is coming right let's say this does not +break if this does not break then what + + align:start position:0% +break if this does not break then what + + + align:start position:0% +break if this does not break then what +would I do now if it does not break I'm + + align:start position:0% +would I do now if it does not break I'm + + + align:start position:0% +would I do now if it does not break I'm +sorry + + align:start position:0% + + + + align:start position:0% + +my bad my bad + + align:start position:0% +my bad my bad + + + align:start position:0% +my bad my bad +take I haven't even actually told you + + align:start position:0% +take I haven't even actually told you + + + align:start position:0% +take I haven't even actually told you +I've just talked about the interval and + + align:start position:0% +I've just talked about the interval and + + + align:start position:0% +I've just talked about the interval and +I haven't said what drop you need to + + align:start position:0% +I haven't said what drop you need to + + + align:start position:0% +I haven't said what drop you need to +make right so so ignore what I said + + align:start position:0% +make right so so ignore what I said + + + align:start position:0% +make right so so ignore what I said +right just now I think that the the next + + align:start position:0% +right just now I think that the the next + + + align:start position:0% +right just now I think that the the next +question is the ball broke and I have a + + align:start position:0% +question is the ball broke and I have a + + + align:start position:0% +question is the ball broke and I have a +second ball and I want the first drop of + + align:start position:0% +second ball and I want the first drop of + + + align:start position:0% +second ball and I want the first drop of +the second ball all right + + align:start position:0% +the second ball all right + + + align:start position:0% +the second ball all right +and I I want to look at this I want to + + align:start position:0% +and I I want to look at this I want to + + + align:start position:0% +and I I want to look at this I want to +look at this interval and it has to be + + align:start position:0% +look at this interval and it has to be + + + align:start position:0% +look at this interval and it has to be +we're inside this interval but it's not + + align:start position:0% +we're inside this interval but it's not + + + align:start position:0% +we're inside this interval but it's not +going to be I'm not I'm not gonna drop + + align:start position:0% +going to be I'm not I'm not gonna drop + + + align:start position:0% +going to be I'm not I'm not gonna drop +this at this floor sixty-five or one + + align:start position:0% +this at this floor sixty-five or one + + + align:start position:0% +this at this floor sixty-five or one +three three three I want to I want to + + align:start position:0% +three three three I want to I want to + + + align:start position:0% +three three three I want to I want to +pick something in between right and so + + align:start position:0% +pick something in between right and so + + + align:start position:0% +pick something in between right and so +now looking at this + + align:start position:0% +now looking at this + + + align:start position:0% +now looking at this +tell me according to what you know so + + align:start position:0% +tell me according to what you know so + + + align:start position:0% +tell me according to what you know so +far where do you think I should drop the + + align:start position:0% +far where do you think I should drop the + + + align:start position:0% +far where do you think I should drop the +second ball for the first time go ahead + + align:start position:0% +second ball for the first time go ahead + + + align:start position:0% +second ball for the first time go ahead +96 and how did you get that you and you + + align:start position:0% +96 and how did you get that you and you + + + align:start position:0% +96 and how did you get that you and you +put one one zero zero perfect + + align:start position:0% +put one one zero zero perfect + + + align:start position:0% +put one one zero zero perfect +what's your name Evan so Evan says 96 I + + align:start position:0% +what's your name Evan so Evan says 96 I + + + align:start position:0% +what's your name Evan so Evan says 96 I +guess he thinks in decimal you know + + align:start position:0% +guess he thinks in decimal you know + + + align:start position:0% +guess he thinks in decimal you know +naturally like most of us but the the + + align:start position:0% +naturally like most of us but the the + + + align:start position:0% +naturally like most of us but the the +way you would code this by the way is by + + align:start position:0% +way you would code this by the way is by + + + align:start position:0% +way you would code this by the way is by +incrementing this digit okay and you'd + + align:start position:0% +incrementing this digit okay and you'd + + + align:start position:0% +incrementing this digit okay and you'd +get one one zero one one zero zero and + + align:start position:0% +get one one zero one one zero zero and + + + align:start position:0% +get one one zero one one zero zero and +in this case let's say it does not break + + align:start position:0% + + + + align:start position:0% + +then I where you go Evan yeah after 96 + + align:start position:0% +then I where you go Evan yeah after 96 + + + align:start position:0% +then I where you go Evan yeah after 96 +it doesn't break what would you do well + + align:start position:0% +it doesn't break what would you do well + + + align:start position:0% +it doesn't break what would you do well +it's in now in and in this + + align:start position:0% +it's in now in and in this + + + align:start position:0% +it's in now in and in this +representation they did an easy it + + align:start position:0% +representation they did an easy it + + + align:start position:0% +representation they did an easy it +whatever is easier for you perfect one + + align:start position:0% +whatever is easier for you perfect one + + + align:start position:0% +whatever is easier for you perfect one +to zero zero which happens to be I think + + align:start position:0% +to zero zero which happens to be I think + + + align:start position:0% +to zero zero which happens to be I think +112 so you go to floor 112 this was 96 + + align:start position:0% +112 so you go to floor 112 this was 96 + + + align:start position:0% +112 so you go to floor 112 this was 96 +all right and then you need to add + + align:start position:0% +all right and then you need to add + + + align:start position:0% +all right and then you need to add +another 16 to that yep 112 and so on + + align:start position:0% +another 16 to that yep 112 and so on + + + align:start position:0% +another 16 to that yep 112 and so on +right so I want I won't bore you with + + align:start position:0% +right so I want I won't bore you with + + + align:start position:0% +right so I want I won't bore you with +this you get a sense of what's what's + + align:start position:0% +this you get a sense of what's what's + + + align:start position:0% +this you get a sense of what's what's +going on here and obviously with these + + align:start position:0% +going on here and obviously with these + + + align:start position:0% +going on here and obviously with these +things you can wave your hands and you + + align:start position:0% +things you can wave your hands and you + + + align:start position:0% +things you can wave your hands and you +get a sense of what's going on but + + align:start position:0% +get a sense of what's going on but + + + align:start position:0% +get a sense of what's going on but +ultimately you know what's great about + + align:start position:0% +ultimately you know what's great about + + + align:start position:0% +ultimately you know what's great about +computer science and programming is + + align:start position:0% +computer science and programming is + + + align:start position:0% +computer science and programming is +there's you got to teach the dumb + + align:start position:0% +there's you got to teach the dumb + + + align:start position:0% +there's you got to teach the dumb +computer to do exactly the right thing + + align:start position:0% +computer to do exactly the right thing + + + align:start position:0% +computer to do exactly the right thing +and there's no two things about it in + + align:start position:0% +and there's no two things about it in + + + align:start position:0% +and there's no two things about it in +terms of you understand this algorithm I + + align:start position:0% +terms of you understand this algorithm I + + + align:start position:0% +terms of you understand this algorithm I +didn't understand this algorithm until I + + align:start position:0% +didn't understand this algorithm until I + + + align:start position:0% +didn't understand this algorithm until I +coded it fully right I mean maybe I + + align:start position:0% +coded it fully right I mean maybe I + + + align:start position:0% +coded it fully right I mean maybe I +still don't understand it considering + + align:start position:0% +still don't understand it considering + + + align:start position:0% +still don't understand it considering +the mistakes I'm making but this is + + align:start position:0% +the mistakes I'm making but this is + + + align:start position:0% +the mistakes I'm making but this is +because I've lost a bunch of gray cells + + align:start position:0% +because I've lost a bunch of gray cells + + + align:start position:0% +because I've lost a bunch of gray cells +so so let me let me show you what the + + align:start position:0% +so so let me let me show you what the + + + align:start position:0% +so so let me let me show you what the +code looks like it's 15 lines of code + + align:start position:0% +code looks like it's 15 lines of code + + + align:start position:0% +code looks like it's 15 lines of code +right it's not that much and as you can + + align:start position:0% +right it's not that much and as you can + + + align:start position:0% +right it's not that much and as you can +imagine the the the representation is I + + align:start position:0% +imagine the the the representation is I + + + align:start position:0% +imagine the the the representation is I +could have used many things I just used + + align:start position:0% +could have used many things I just used + + + align:start position:0% +could have used many things I just used +a list for each of these digits I'm + + align:start position:0% +a list for each of these digits I'm + + + align:start position:0% +a list for each of these digits I'm +incrementing these these digits and will + + align:start position:0% +incrementing these these digits and will + + + align:start position:0% +incrementing these these digits and will +I want to spend a whole lot of time on + + align:start position:0% +I want to spend a whole lot of time on + + + align:start position:0% +I want to spend a whole lot of time on +the code but what I want to do before we + + align:start position:0% +the code but what I want to do before we + + + align:start position:0% +the code but what I want to do before we +end here is talk about actually let me + + align:start position:0% +end here is talk about actually let me + + + align:start position:0% +end here is talk about actually let me +do that first before we we go to the + + align:start position:0% +do that first before we we go to the + + + align:start position:0% +do that first before we we go to the +code I want to talk about the worst case + + align:start position:0% +code I want to talk about the worst case + + + align:start position:0% +code I want to talk about the worst case +here right because that's all that's + + align:start position:0% +here right because that's all that's + + + align:start position:0% +here right because that's all that's +what this is all about I want to get an + + align:start position:0% +what this is all about I want to get an + + + align:start position:0% +what this is all about I want to get an +equation just like we did for two times + + align:start position:0% +equation just like we did for two times + + + align:start position:0% +equation just like we did for two times +square root of n minus one and all of + + align:start position:0% +square root of n minus one and all of + + + align:start position:0% +square root of n minus one and all of +these different things I want to get an + + align:start position:0% +these different things I want to get an + + + align:start position:0% +these different things I want to get an +equation for the worst case in terms of + + align:start position:0% +equation for the worst case in terms of + + + align:start position:0% +equation for the worst case in terms of +the number of drops in relation to R and + + align:start position:0% +the number of drops in relation to R and + + + align:start position:0% +the number of drops in relation to R and +D which are obviously related to n right + + align:start position:0% +D which are obviously related to n right + + + align:start position:0% +D which are obviously related to n right +because our raise to D has to be greater + + align:start position:0% +because our raise to D has to be greater + + + align:start position:0% +because our raise to D has to be greater +than n right so if you kind of look at + + align:start position:0% +than n right so if you kind of look at + + + align:start position:0% +than n right so if you kind of look at +this and it turns out this is not a + + align:start position:0% +this and it turns out this is not a + + + align:start position:0% +this and it turns out this is not a +difficult analysis right if you if you + + align:start position:0% +difficult analysis right if you if you + + + align:start position:0% +difficult analysis right if you if you +think if you think about it and you + + align:start position:0% +think if you think about it and you + + + align:start position:0% +think if you think about it and you +start thinking about worst case and you + + align:start position:0% +start thinking about worst case and you + + + align:start position:0% +start thinking about worst case and you +think about how we are incrementing + + align:start position:0% +think about how we are incrementing + + + align:start position:0% +think about how we are incrementing +these things um these phases and if you + + align:start position:0% +these things um these phases and if you + + + align:start position:0% +these things um these phases and if you +can think about a phase as as when a + + align:start position:0% +can think about a phase as as when a + + + align:start position:0% +can think about a phase as as when a +better ball breaks you know that's when + + align:start position:0% +better ball breaks you know that's when + + + align:start position:0% +better ball breaks you know that's when +a phase is done and you move to the + + align:start position:0% +a phase is done and you move to the + + + align:start position:0% +a phase is done and you move to the +second phase right tell me I what how + + align:start position:0% +second phase right tell me I what how + + + align:start position:0% +second phase right tell me I what how +many drops I have you break break it up + + align:start position:0% +many drops I have you break break it up + + + align:start position:0% +many drops I have you break break it up +in terms of the number of phases right + + align:start position:0% +in terms of the number of phases right + + + align:start position:0% +in terms of the number of phases right +or the number of balls whichever way you + + align:start position:0% +or the number of balls whichever way you + + + align:start position:0% +or the number of balls whichever way you +want to think about it and use the same + + align:start position:0% +want to think about it and use the same + + + align:start position:0% +want to think about it and use the same +kind of worst-case analysis we've done + + align:start position:0% +kind of worst-case analysis we've done + + + align:start position:0% +kind of worst-case analysis we've done +with respect to what happens what + + align:start position:0% +with respect to what happens what + + + align:start position:0% +with respect to what happens what +happens in the in the worst case you + + align:start position:0% +happens in the in the worst case you + + + align:start position:0% +happens in the in the worst case you +have to keep you know doing a bunch of + + align:start position:0% +have to keep you know doing a bunch of + + + align:start position:0% +have to keep you know doing a bunch of +drops and in really for these algorithms + + align:start position:0% +drops and in really for these algorithms + + + align:start position:0% +drops and in really for these algorithms +the floor 127 the hardness coefficient + + align:start position:0% +the floor 127 the hardness coefficient + + + align:start position:0% +the floor 127 the hardness coefficient +of of actually the hardness coefficient + + align:start position:0% +of of actually the hardness coefficient + + + align:start position:0% +of of actually the hardness coefficient +of 127 was is this the hard one right + + align:start position:0% +of 127 was is this the hard one right + + + align:start position:0% +of 127 was is this the hard one right +it's it's a difficult one because you + + align:start position:0% +it's it's a difficult one because you + + + align:start position:0% +it's it's a difficult one because you +kind of go through and you go all the + + align:start position:0% +kind of go through and you go all the + + + align:start position:0% +kind of go through and you go all the +way there and you do all of these things + + align:start position:0% +way there and you do all of these things + + + align:start position:0% +way there and you do all of these things +before you drop a ball a lot of times + + align:start position:0% +before you drop a ball a lot of times + + + align:start position:0% +before you drop a ball a lot of times +before it breaks and you do that for + + align:start position:0% +before it breaks and you do that for + + + align:start position:0% +before it breaks and you do that for +every ball right that would be the worst + + align:start position:0% +every ball right that would be the worst + + + align:start position:0% +every ball right that would be the worst +case right so that's kind of where + + align:start position:0% +case right so that's kind of where + + + align:start position:0% +case right so that's kind of where +things are at so from a symbolic + + align:start position:0% +things are at so from a symbolic + + + align:start position:0% +things are at so from a symbolic +standpoint what is the worst case in the + + align:start position:0% +standpoint what is the worst case in the + + + align:start position:0% +standpoint what is the worst case in the +first phase in terms of the number of + + align:start position:0% +first phase in terms of the number of + + + align:start position:0% +first phase in terms of the number of +of the first ball from a symbolic + + align:start position:0% +of the first ball from a symbolic + + + align:start position:0% +of the first ball from a symbolic +standpoint right it's the first digit + + align:start position:0% +standpoint right it's the first digit + + + align:start position:0% +standpoint right it's the first digit +I'm talking about it's the first ball + + align:start position:0% +I'm talking about it's the first ball + + + align:start position:0% +I'm talking about it's the first ball +I'm talking about and I'm dropping this + + align:start position:0% +I'm talking about and I'm dropping this + + + align:start position:0% +I'm talking about and I'm dropping this +ball as you can see at these different + + align:start position:0% +ball as you can see at these different + + + align:start position:0% +ball as you can see at these different +points so in general how many drops + + align:start position:0% +points so in general how many drops + + + align:start position:0% +points so in general how many drops +would I have + + align:start position:0% +would I have + + + align:start position:0% +would I have +Minoo either I may be done completely + + align:start position:0% +Minoo either I may be done completely + + + align:start position:0% +Minoo either I may be done completely +because it I know it doesn't break it + + align:start position:0% +because it I know it doesn't break it + + + align:start position:0% +because it I know it doesn't break it +floor 128 or what I have you but what is + + align:start position:0% +floor 128 or what I have you but what is + + + align:start position:0% +floor 128 or what I have you but what is +what is the worst case when that ball + + align:start position:0% +what is the worst case when that ball + + + align:start position:0% +what is the worst case when that ball +breaks give me an equation someone + + align:start position:0% +breaks give me an equation someone + + + align:start position:0% +breaks give me an equation someone +what's so I drop it once I drop it twice + + align:start position:0% +what's so I drop it once I drop it twice + + + align:start position:0% +what's so I drop it once I drop it twice +and I am I going to drop it like like if + + align:start position:0% +and I am I going to drop it like like if + + + align:start position:0% +and I am I going to drop it like like if +R is five am I gonna drop it ten times + + align:start position:0% +R is five am I gonna drop it ten times + + + align:start position:0% +R is five am I gonna drop it ten times +I'm what am i doing in terms of the what + + align:start position:0% +I'm what am i doing in terms of the what + + + align:start position:0% +I'm what am i doing in terms of the what +is the upper limit in terms of this this + + align:start position:0% +is the upper limit in terms of this this + + + align:start position:0% +is the upper limit in terms of this this +digit our minus one and where am i + + align:start position:0% +digit our minus one and where am i + + + align:start position:0% +digit our minus one and where am i +starting from one right so there you go + + align:start position:0% +starting from one right so there you go + + + align:start position:0% +starting from one right so there you go +what's enough course answer our minus 1 + + align:start position:0% +what's enough course answer our minus 1 + + + align:start position:0% +what's enough course answer our minus 1 +right so that's it so it turns out that + + align:start position:0% +right so that's it so it turns out that + + + align:start position:0% +right so that's it so it turns out that +I have R minus 1 drops in the worst case + + align:start position:0% +I have R minus 1 drops in the worst case + + + align:start position:0% +I have R minus 1 drops in the worst case +for the first ball and I mean it's a + + align:start position:0% +for the first ball and I mean it's a + + + align:start position:0% +for the first ball and I mean it's a +same representation every digit is the + + align:start position:0% +same representation every digit is the + + + align:start position:0% +same representation every digit is the +same radix obviously right and now that + + align:start position:0% +same radix obviously right and now that + + + align:start position:0% +same radix obviously right and now that +that ball broke and I moved to that to + + align:start position:0% +that ball broke and I moved to that to + + + align:start position:0% +that ball broke and I moved to that to +the second digit with the second ball + + align:start position:0% +the second digit with the second ball + + + align:start position:0% +the second digit with the second ball +and I'm gonna start again and in the + + align:start position:0% +and I'm gonna start again and in the + + + align:start position:0% +and I'm gonna start again and in the +worst case I could have R minus 1 drops + + align:start position:0% +worst case I could have R minus 1 drops + + + align:start position:0% +worst case I could have R minus 1 drops +with that as well right because I'm + + align:start position:0% +with that as well right because I'm + + + align:start position:0% +with that as well right because I'm +gonna go increment from 0 the first one + + align:start position:0% +gonna go increment from 0 the first one + + + align:start position:0% +gonna go increment from 0 the first one +I'm going to do is a 1 and then I'm + + align:start position:0% +I'm going to do is a 1 and then I'm + + + align:start position:0% +I'm going to do is a 1 and then I'm +gonna do a two and all the way to R + + align:start position:0% +gonna do a two and all the way to R + + + align:start position:0% +gonna do a two and all the way to R +minus 1 right so our minus 1 drops for + + align:start position:0% +minus 1 right so our minus 1 drops for + + + align:start position:0% +minus 1 right so our minus 1 drops for +the second ball and then I go all the + + align:start position:0% +the second ball and then I go all the + + + align:start position:0% +the second ball and then I go all the +way to D balls so so my answer + + align:start position:0% + + + + align:start position:0% + +yeah go ahead yes you're absolutely + + align:start position:0% +yeah go ahead yes you're absolutely + + + align:start position:0% +yeah go ahead yes you're absolutely +right that but if the if the number were + + align:start position:0% +right that but if the if the number were + + + align:start position:0% +right that but if the if the number were +255 so one of the things that's + + align:start position:0% +255 so one of the things that's + + + align:start position:0% +255 so one of the things that's +happening here is we have lost some + + align:start position:0% +happening here is we have lost some + + + align:start position:0% +happening here is we have lost some +precision because our raise to D needed + + align:start position:0% +precision because our raise to D needed + + + align:start position:0% +precision because our raise to D needed +to be this large number of 255 and this + + align:start position:0% +to be this large number of 255 and this + + + align:start position:0% +to be this large number of 255 and this +algorithm is actually going to work for + + align:start position:0% +algorithm is actually going to work for + + + align:start position:0% +algorithm is actually going to work for +255 floors all right + + align:start position:0% +255 floors all right + + + align:start position:0% +255 floors all right +yeah because of em so so so it's not + + align:start position:0% +yeah because of em so so so it's not + + + align:start position:0% +yeah because of em so so so it's not +yeah so that's kind of you know the it's + + align:start position:0% +yeah so that's kind of you know the it's + + + align:start position:0% +yeah so that's kind of you know the it's +a good question you asked but + + align:start position:0% +a good question you asked but + + + align:start position:0% +a good question you asked but +unfortunately you kind of want to choose + + align:start position:0% +unfortunately you kind of want to choose + + + align:start position:0% +unfortunately you kind of want to choose +a case where you you have perfect + + align:start position:0% +a case where you you have perfect + + + align:start position:0% +a case where you you have perfect +precision in terms of R raised to D is + + align:start position:0% +precision in terms of R raised to D is + + + align:start position:0% +precision in terms of R raised to D is +exactly what you need it to be and in + + align:start position:0% +exactly what you need it to be and in + + + align:start position:0% +exactly what you need it to be and in +that case this analysis works right yeah + + align:start position:0% +that case this analysis works right yeah + + + align:start position:0% +that case this analysis works right yeah +that's the max n that does exactly right + + align:start position:0% +that's the max n that does exactly right + + + align:start position:0% +that's the max n that does exactly right +so I mean 255 is substantially larger + + align:start position:0% +so I mean 255 is substantially larger + + + align:start position:0% +so I mean 255 is substantially larger +than 128 so it kind of makes sense that + + align:start position:0% +than 128 so it kind of makes sense that + + + align:start position:0% +than 128 so it kind of makes sense that +that as you said that you would be able + + align:start position:0% +that as you said that you would be able + + + align:start position:0% +that as you said that you would be able +to shave off certain things right and so + + align:start position:0% +to shave off certain things right and so + + + align:start position:0% +to shave off certain things right and so +you can kind of do that but it's a + + align:start position:0% +you can kind of do that but it's a + + + align:start position:0% +you can kind of do that but it's a +little more involved but I think the the + + align:start position:0% +little more involved but I think the the + + + align:start position:0% +little more involved but I think the the +intuition is important and the intuition + + align:start position:0% +intuition is important and the intuition + + + align:start position:0% +intuition is important and the intuition +is simply that your worst case number of + + align:start position:0% +is simply that your worst case number of + + + align:start position:0% +is simply that your worst case number of +drops assuming you're being a little bit + + align:start position:0% +drops assuming you're being a little bit + + + align:start position:0% +drops assuming you're being a little bit +imprecise would simply be R minus 1 + + align:start position:0% +imprecise would simply be R minus 1 + + + align:start position:0% +imprecise would simply be R minus 1 +times D in the in the worst case and + + align:start position:0% +times D in the in the worst case and + + + align:start position:0% +times D in the in the worst case and +this would be true for all n which is + + align:start position:0% +this would be true for all n which is + + + align:start position:0% +this would be true for all n which is +less than R raised to D you know for all + + align:start position:0% +less than R raised to D you know for all + + + align:start position:0% +less than R raised to D you know for all +n all right so it's a so now just in + + align:start position:0% +n all right so it's a so now just in + + + align:start position:0% +n all right so it's a so now just in +terms of numbers I had R equals 4 and D + + align:start position:0% +terms of numbers I had R equals 4 and D + + + align:start position:0% +terms of numbers I had R equals 4 and D +equals 4 and so you end up getting 12 + + align:start position:0% +equals 4 and so you end up getting 12 + + + align:start position:0% +equals 4 and so you end up getting 12 +drops for the 128th case all the way do + + align:start position:0% +drops for the 128th case all the way do + + + align:start position:0% +drops for the 128th case all the way do +you know 255 as well + + align:start position:0% +you know 255 as well + + + align:start position:0% +you know 255 as well +you need you need 12 drops in the worst + + align:start position:0% +you need you need 12 drops in the worst + + + align:start position:0% +you need you need 12 drops in the worst +case even for 255 floors right which + + align:start position:0% +case even for 255 floors right which + + + align:start position:0% +case even for 255 floors right which +which is really what you were asking + + align:start position:0% +which is really what you were asking + + + align:start position:0% +which is really what you were asking +right so good all right that makes sense + + align:start position:0% +right so good all right that makes sense + + + align:start position:0% +right so good all right that makes sense +yeah so I'm not gonna spend a whole lot + + align:start position:0% +yeah so I'm not gonna spend a whole lot + + + align:start position:0% +yeah so I'm not gonna spend a whole lot +of time on this code but that's it + + align:start position:0% +of time on this code but that's it + + + align:start position:0% +of time on this code but that's it +it + + align:start position:0% +it + + + align:start position:0% +it +converting I could have used a Python + + align:start position:0% +converting I could have used a Python + + + align:start position:0% +converting I could have used a Python +library function for that but that's + + align:start position:0% +library function for that but that's + + + align:start position:0% +library function for that but that's +simply a conversion because I wanted to + + align:start position:0% +simply a conversion because I wanted to + + + align:start position:0% +simply a conversion because I wanted to +print things out I don't even need that + + align:start position:0% +print things out I don't even need that + + + align:start position:0% +print things out I don't even need that +this particular subroutine which is + + align:start position:0% +this particular subroutine which is + + + align:start position:0% +this particular subroutine which is +essentially something that is doing + + align:start position:0% +essentially something that is doing + + + align:start position:0% +essentially something that is doing +conversion from a decimal to do to our + + align:start position:0% +conversion from a decimal to do to our + + + align:start position:0% +conversion from a decimal to do to our +arithmetic and as you can see you see a + + align:start position:0% +arithmetic and as you can see you see a + + + align:start position:0% +arithmetic and as you can see you see a +subtract in and and adding the the the + + align:start position:0% +subtract in and and adding the the the + + + align:start position:0% +subtract in and and adding the the the +adding is is the incrementation that I + + align:start position:0% +adding is is the incrementation that I + + + align:start position:0% +adding is is the incrementation that I +just erased but you do see it up there + + align:start position:0% +just erased but you do see it up there + + + align:start position:0% +just erased but you do see it up there +from 1 0 to 2 0 that's why you add + + align:start position:0% +from 1 0 to 2 0 that's why you add + + + align:start position:0% +from 1 0 to 2 0 that's why you add +sometimes you need to subtract because + + align:start position:0% +sometimes you need to subtract because + + + align:start position:0% +sometimes you need to subtract because +things break and when things break you + + align:start position:0% +things break and when things break you + + + align:start position:0% +things break and when things break you +you need to go back to the to the + + align:start position:0% +you need to go back to the to the + + + align:start position:0% +you need to go back to the to the +highest floor where the ball didn't + + align:start position:0% +highest floor where the ball didn't + + + align:start position:0% +highest floor where the ball didn't +break right so that's where you you you + + align:start position:0% +break right so that's where you you you + + + align:start position:0% +break right so that's where you you you +have you do the subtraction and so this + + align:start position:0% +have you do the subtraction and so this + + + align:start position:0% +have you do the subtraction and so this +is how if you ran this this it's not the + + align:start position:0% +is how if you ran this this it's not the + + + align:start position:0% +is how if you ran this this it's not the +greatest user user interface I'll admit + + align:start position:0% +greatest user user interface I'll admit + + + align:start position:0% +greatest user user interface I'll admit +but that's not the point + + align:start position:0% + + + + align:start position:0% + +so I'm gonna do 128 and 4 which is our + + align:start position:0% +so I'm gonna do 128 and 4 which is our + + + align:start position:0% +so I'm gonna do 128 and 4 which is our +example + + align:start position:0% +example + + + align:start position:0% +example +and he says radix shows in his ball 4 + + align:start position:0% +and he says radix shows in his ball 4 + + + align:start position:0% +and he says radix shows in his ball 4 +did the ball break I say no and then I + + align:start position:0% +did the ball break I say no and then I + + + align:start position:0% +did the ball break I say no and then I +you know did they drop the ball did the + + align:start position:0% +you know did they drop the ball did the + + + align:start position:0% +you know did they drop the ball did the +ball break if I say no here then I'm + + align:start position:0% +ball break if I say no here then I'm + + + align:start position:0% +ball break if I say no here then I'm +done right so I'm gonna go ahead and say + + align:start position:0% +done right so I'm gonna go ahead and say + + + align:start position:0% +done right so I'm gonna go ahead and say +yes and then I'm gonna say no and then + + align:start position:0% +yes and then I'm gonna say no and then + + + align:start position:0% +yes and then I'm gonna say no and then +no I'm gonna keep going no no no because + + align:start position:0% +no I'm gonna keep going no no no because + + + align:start position:0% +no I'm gonna keep going no no no because +this is the worst case and I got 11 + + align:start position:0% +this is the worst case and I got 11 + + + align:start position:0% +this is the worst case and I got 11 +right in this case so you do get closed + + align:start position:0% +right in this case so you do get closed + + + align:start position:0% +right in this case so you do get closed +in in the sense that grata was asking + + align:start position:0% +in in the sense that grata was asking + + + align:start position:0% +in in the sense that grata was asking +you know could you shave off you only + + align:start position:0% +you know could you shave off you only + + + align:start position:0% +you know could you shave off you only +shaved off one because of the + + align:start position:0% +shaved off one because of the + + + align:start position:0% +shaved off one because of the +imprecision so there is a case where + + align:start position:0% +imprecision so there is a case where + + + align:start position:0% +imprecision so there is a case where +even though you would only get 12 for + + align:start position:0% +even though you would only get 12 for + + + align:start position:0% +even though you would only get 12 for +255 but you do get 11 for 128 okay all + + align:start position:0% +255 but you do get 11 for 128 okay all + + + align:start position:0% +255 but you do get 11 for 128 okay all +right cool + + align:start position:0% +right cool + + + align:start position:0% +right cool +good so I'll let you look at the code if + + align:start position:0% +good so I'll let you look at the code if + + + align:start position:0% +good so I'll let you look at the code if +you guys can again can leave anytime you + + align:start position:0% +you guys can again can leave anytime you + + + align:start position:0% +you guys can again can leave anytime you +want I just wanted to mention I want to + + align:start position:0% +want I just wanted to mention I want to + + + align:start position:0% +want I just wanted to mention I want to +go back to the one thing that I didn't + + align:start position:0% +go back to the one thing that I didn't + + + align:start position:0% +go back to the one thing that I didn't +get that I mentioned but I haven't + + align:start position:0% +get that I mentioned but I haven't + + + align:start position:0% +get that I mentioned but I haven't +gotten to which is this is still you can + + align:start position:0% +gotten to which is this is still you can + + + align:start position:0% +gotten to which is this is still you can +still do better right you can still do + + align:start position:0% +still do better right you can still do + + + align:start position:0% +still do better right you can still do +better + + align:start position:0% +better + + + align:start position:0% +better +not because of what guna Tara mentioned + + align:start position:0% +not because of what guna Tara mentioned + + + align:start position:0% +not because of what guna Tara mentioned +you know that's just that imprecision + + align:start position:0% +you know that's just that imprecision + + + align:start position:0% +you know that's just that imprecision +thing but assuming even that was taken + + align:start position:0% +thing but assuming even that was taken + + + align:start position:0% +thing but assuming even that was taken +care of because the numbers worked out + + align:start position:0% +care of because the numbers worked out + + + align:start position:0% +care of because the numbers worked out +you can do better because K can be made + + align:start position:0% +you can do better because K can be made + + + align:start position:0% +you can do better because K can be made +different you could do unequal intervals + + align:start position:0% +different you could do unequal intervals + + + align:start position:0% +different you could do unequal intervals +right so let me put that into the in the + + align:start position:0% +right so let me put that into the in the + + + align:start position:0% +right so let me put that into the in the +notes and you can read it by yourself + + align:start position:0% +notes and you can read it by yourself + + + align:start position:0% +notes and you can read it by yourself +you had a question not even start asking + + align:start position:0% +you had a question not even start asking + + + align:start position:0% +you had a question not even start asking +you or why did I start telling you where + + align:start position:0% +you or why did I start telling you where + + + align:start position:0% +you or why did I start telling you where +like put a next ball drop because it + + align:start position:0% +like put a next ball drop because it + + + align:start position:0% +like put a next ball drop because it +went one two and + + align:start position:0% +went one two and + + + align:start position:0% +went one two and +and went also to ball three and ball + + align:start position:0% +and went also to ball three and ball + + + align:start position:0% +and went also to ball three and ball +four I'm gonna just state ball - that's + + align:start position:0% +four I'm gonna just state ball - that's + + + align:start position:0% +four I'm gonna just state ball - that's +that's because I'm lazy yeah + + align:start position:0% +that's because I'm lazy yeah + + + align:start position:0% +that's because I'm lazy yeah +so it'd be a fine exercise to fix that I + + align:start position:0% +so it'd be a fine exercise to fix that I + + + align:start position:0% +so it'd be a fine exercise to fix that I +mean it's not one of the it's not one of + + align:start position:0% +mean it's not one of the it's not one of + + + align:start position:0% +mean it's not one of the it's not one of +the exercises that's how you turn you + + align:start position:0% +the exercises that's how you turn you + + + align:start position:0% +the exercises that's how you turn you +know after 30 years of teaching whenever + + align:start position:0% +know after 30 years of teaching whenever + + + align:start position:0% +know after 30 years of teaching whenever +I get a question I turn it into an + + align:start position:0% +I get a question I turn it into an + + + align:start position:0% +I get a question I turn it into an +opportunity you know for homework okay + + align:start position:0% +opportunity you know for homework okay + + + align:start position:0% +opportunity you know for homework okay +all right that's how it works + + align:start position:0% +all right that's how it works + + + align:start position:0% +all right that's how it works +all right good see you guys next time \ No newline at end of file diff --git a/FqiB9tmtdSc.txt b/FqiB9tmtdSc.txt new file mode 100644 index 0000000000000000000000000000000000000000..b04b460fa5521c154b90453faf32fd91738558be --- /dev/null +++ b/FqiB9tmtdSc.txt @@ -0,0 +1,1219 @@ +align:start position:0% + +preprocessing the data can be difficult + + align:start position:0% +preprocessing the data can be difficult + + + align:start position:0% +preprocessing the data can be difficult +but luckily ours packages provide + + align:start position:0% +but luckily ours packages provide + + + align:start position:0% +but luckily ours packages provide +easy-to-use functions for the most + + align:start position:0% +easy-to-use functions for the most + + + align:start position:0% +easy-to-use functions for the most +common tasks in this video will load and + + align:start position:0% +common tasks in this video will load and + + + align:start position:0% +common tasks in this video will load and +process our data in our in your our + + align:start position:0% +process our data in our in your our + + + align:start position:0% +process our data in our in your our +console let's load the data set + + align:start position:0% +console let's load the data set + + + align:start position:0% +console let's load the data set +tweets dot csv with the read csv + + align:start position:0% +tweets dot csv with the read csv + + + align:start position:0% +tweets dot csv with the read csv +function but since we're working with + + align:start position:0% +function but since we're working with + + + align:start position:0% +function but since we're working with +text data here we need one extra + + align:start position:0% +text data here we need one extra + + + align:start position:0% +text data here we need one extra +argument which is strings as factors + + align:start position:0% +argument which is strings as factors + + + align:start position:0% +argument which is strings as factors +equals false so we'll call our data set + + align:start position:0% +equals false so we'll call our data set + + + align:start position:0% +equals false so we'll call our data set +tweets and we'll use the read csv + + align:start position:0% +tweets and we'll use the read csv + + + align:start position:0% +tweets and we'll use the read csv +function to read in the data file tweets + + align:start position:0% +function to read in the data file tweets + + + align:start position:0% +function to read in the data file tweets +dot csv but then we'll add the extra + + align:start position:0% +dot csv but then we'll add the extra + + + align:start position:0% +dot csv but then we'll add the extra +argument strings as factors equals false + + align:start position:0% +argument strings as factors equals false + + + align:start position:0% +argument strings as factors equals false +you'll always need to add this extra + + align:start position:0% +you'll always need to add this extra + + + align:start position:0% +you'll always need to add this extra +argument when working on a text + + align:start position:0% +argument when working on a text + + + align:start position:0% +argument when working on a text +analytics problem so that the text is + + align:start position:0% +analytics problem so that the text is + + + align:start position:0% +analytics problem so that the text is +read in properly now let's take a look + + align:start position:0% +read in properly now let's take a look + + + align:start position:0% +read in properly now let's take a look +at the structure of our data with the + + align:start position:0% +at the structure of our data with the + + + align:start position:0% +at the structure of our data with the +STR function we can see that we have one + + align:start position:0% +STR function we can see that we have one + + + align:start position:0% +STR function we can see that we have one +thousand one hundred and eighty-one + + align:start position:0% +thousand one hundred and eighty-one + + + align:start position:0% +thousand one hundred and eighty-one +observations of two variables the text + + align:start position:0% +observations of two variables the text + + + align:start position:0% +observations of two variables the text +of the tweet called tweet and the + + align:start position:0% +of the tweet called tweet and the + + + align:start position:0% +of the tweet called tweet and the +average sentiment score called AVG for + + align:start position:0% +average sentiment score called AVG for + + + align:start position:0% +average sentiment score called AVG for +average the tweet texts are real tweets + + align:start position:0% +average the tweet texts are real tweets + + + align:start position:0% +average the tweet texts are real tweets +that we found on the internet directed + + align:start position:0% +that we found on the internet directed + + + align:start position:0% +that we found on the internet directed +to apple with a few cleaned up words + + align:start position:0% +to apple with a few cleaned up words + + + align:start position:0% +to apple with a few cleaned up words +we're more interested in being able to + + align:start position:0% +we're more interested in being able to + + + align:start position:0% +we're more interested in being able to +detect the tweets with clear negative + + align:start position:0% +detect the tweets with clear negative + + + align:start position:0% +detect the tweets with clear negative +sentiment so let's define a new variable + + align:start position:0% +sentiment so let's define a new variable + + + align:start position:0% +sentiment so let's define a new variable +in our data set tweets called negative + + align:start position:0% +in our data set tweets called negative + + + align:start position:0% +in our data set tweets called negative +and we'll set this equal to AZ dot + + align:start position:0% +and we'll set this equal to AZ dot + + + align:start position:0% +and we'll set this equal to AZ dot +factor tweets dollar sign AVG for + + align:start position:0% +factor tweets dollar sign AVG for + + + align:start position:0% +factor tweets dollar sign AVG for +average less than or equal to negative + + align:start position:0% +average less than or equal to negative + + + align:start position:0% +average less than or equal to negative +one this will set tweets negative equal + + align:start position:0% +one this will set tweets negative equal + + + align:start position:0% +one this will set tweets negative equal +to true if the average sentiment score + + align:start position:0% +to true if the average sentiment score + + + align:start position:0% +to true if the average sentiment score +is less than or equal to negative one + + align:start position:0% +is less than or equal to negative one + + + align:start position:0% +is less than or equal to negative one +and we'll set tweets negative equal to + + align:start position:0% +and we'll set tweets negative equal to + + + align:start position:0% +and we'll set tweets negative equal to +false if the average sentiment score is + + align:start position:0% +false if the average sentiment score is + + + align:start position:0% +false if the average sentiment score is +greater than negative one let's look at + + align:start position:0% +greater than negative one let's look at + + + align:start position:0% +greater than negative one let's look at +a table of this new variable negative + + align:start position:0% + + + + align:start position:0% + +we can see that 182 of the 1181 tweets + + align:start position:0% +we can see that 182 of the 1181 tweets + + + align:start position:0% +we can see that 182 of the 1181 tweets +or about 15% are negative now to + + align:start position:0% +or about 15% are negative now to + + + align:start position:0% +or about 15% are negative now to +pre-process our text a test that we can + + align:start position:0% +pre-process our text a test that we can + + + align:start position:0% +pre-process our text a test that we can +use the bag-of-words approach will be + + align:start position:0% +use the bag-of-words approach will be + + + align:start position:0% +use the bag-of-words approach will be +using the TM text mining package we'll + + align:start position:0% +using the TM text mining package we'll + + + align:start position:0% +using the TM text mining package we'll +need to install and load two packages to + + align:start position:0% +need to install and load two packages to + + + align:start position:0% +need to install and load two packages to +do this first let's install the package + + align:start position:0% +do this first let's install the package + + + align:start position:0% +do this first let's install the package +TM and go ahead and select a Korean Muir + + align:start position:0% +TM and go ahead and select a Korean Muir + + + align:start position:0% +TM and go ahead and select a Korean Muir +near you as soon as that package is done + + align:start position:0% +near you as soon as that package is done + + + align:start position:0% +near you as soon as that package is done +installing in your back at the blinking + + align:start position:0% +installing in your back at the blinking + + + align:start position:0% +installing in your back at the blinking +cursor go ahead and load that package + + align:start position:0% +cursor go ahead and load that package + + + align:start position:0% +cursor go ahead and load that package +with the library command then we also + + align:start position:0% +with the library command then we also + + + align:start position:0% +with the library command then we also +need to install the package snowball see + + align:start position:0% +need to install the package snowball see + + + align:start position:0% +need to install the package snowball see +this package helps us use the TM package + + align:start position:0% +this package helps us use the TM package + + + align:start position:0% +this package helps us use the TM package +and go ahead and load the snowball + + align:start position:0% +and go ahead and load the snowball + + + align:start position:0% +and go ahead and load the snowball +package as well one of the concepts + + align:start position:0% +package as well one of the concepts + + + align:start position:0% +package as well one of the concepts +introduced by the TM package is that of + + align:start position:0% +introduced by the TM package is that of + + + align:start position:0% +introduced by the TM package is that of +a corpus a corpus is a collection of + + align:start position:0% +a corpus a corpus is a collection of + + + align:start position:0% +a corpus a corpus is a collection of +documents we'll need to convert our + + align:start position:0% +documents we'll need to convert our + + + align:start position:0% +documents we'll need to convert our +tweets to a corpus for pre-processing TM + + align:start position:0% +tweets to a corpus for pre-processing TM + + + align:start position:0% +tweets to a corpus for pre-processing TM +can create a corpus in many different + + align:start position:0% +can create a corpus in many different + + + align:start position:0% +can create a corpus in many different +ways but we'll create it from the tweet + + align:start position:0% +ways but we'll create it from the tweet + + + align:start position:0% +ways but we'll create it from the tweet +column of our data frame using two + + align:start position:0% +column of our data frame using two + + + align:start position:0% +column of our data frame using two +functions corpus and vector source we'll + + align:start position:0% +functions corpus and vector source we'll + + + align:start position:0% +functions corpus and vector source we'll +call our corpus corpus and then use the + + align:start position:0% +call our corpus corpus and then use the + + + align:start position:0% +call our corpus corpus and then use the +corpus and the vector source functions + + align:start position:0% +corpus and the vector source functions + + + align:start position:0% +corpus and the vector source functions +calls on our tweets variable of our + + align:start position:0% +calls on our tweets variable of our + + + align:start position:0% +calls on our tweets variable of our +tweets dataset + + align:start position:0% +tweets dataset + + + align:start position:0% +tweets dataset +so that's tweets dollar sign tweet we + + align:start position:0% +so that's tweets dollar sign tweet we + + + align:start position:0% +so that's tweets dollar sign tweet we +can check that this has worked by typing + + align:start position:0% +can check that this has worked by typing + + + align:start position:0% +can check that this has worked by typing +corpus and seeing that our corpus has + + align:start position:0% +corpus and seeing that our corpus has + + + align:start position:0% +corpus and seeing that our corpus has +1181 text documents and we can check + + align:start position:0% +1181 text documents and we can check + + + align:start position:0% +1181 text documents and we can check +that the documents match our tweets by + + align:start position:0% +that the documents match our tweets by + + + align:start position:0% +that the documents match our tweets by +using double brackets so type corpus - + + align:start position:0% +using double brackets so type corpus - + + + align:start position:0% +using double brackets so type corpus - +left square brackets the number one and + + align:start position:0% +left square brackets the number one and + + + align:start position:0% +left square brackets the number one and +two right square brackets this shows us + + align:start position:0% +two right square brackets this shows us + + + align:start position:0% +two right square brackets this shows us +the first tweet in our corpus now we're + + align:start position:0% +the first tweet in our corpus now we're + + + align:start position:0% +the first tweet in our corpus now we're +ready to start pre-processing our data + + align:start position:0% +ready to start pre-processing our data + + + align:start position:0% +ready to start pre-processing our data +pre-processing is easy in TN each + + align:start position:0% +pre-processing is easy in TN each + + + align:start position:0% +pre-processing is easy in TN each +operation + + align:start position:0% +operation + + + align:start position:0% +operation +stemming or removing stop words can be + + align:start position:0% +stemming or removing stop words can be + + + align:start position:0% +stemming or removing stop words can be +done with one line in our where we use + + align:start position:0% +done with one line in our where we use + + + align:start position:0% +done with one line in our where we use +the TM map function let's try it out by + + align:start position:0% +the TM map function let's try it out by + + + align:start position:0% +the TM map function let's try it out by +changing all of the text in our tweets + + align:start position:0% +changing all of the text in our tweets + + + align:start position:0% +changing all of the text in our tweets +to lowercase to do that will replace our + + align:start position:0% +to lowercase to do that will replace our + + + align:start position:0% +to lowercase to do that will replace our +corpus with the output of the TM + + align:start position:0% +corpus with the output of the TM + + + align:start position:0% +corpus with the output of the TM +underscore map function where the first + + align:start position:0% +underscore map function where the first + + + align:start position:0% +underscore map function where the first +argument is the name of our corpus and + + align:start position:0% +argument is the name of our corpus and + + + align:start position:0% +argument is the name of our corpus and +the second argument is what we want to + + align:start position:0% +the second argument is what we want to + + + align:start position:0% +the second argument is what we want to +do in this case - lower - lower is a + + align:start position:0% +do in this case - lower - lower is a + + + align:start position:0% +do in this case - lower - lower is a +standard function in our and this is + + align:start position:0% +standard function in our and this is + + + align:start position:0% +standard function in our and this is +like when we pass mean to the T apply + + align:start position:0% +like when we pass mean to the T apply + + + align:start position:0% +like when we pass mean to the T apply +function we're passing the TM map + + align:start position:0% +function we're passing the TM map + + + align:start position:0% +function we're passing the TM map +function a function to use on our corpus + + align:start position:0% +function a function to use on our corpus + + + align:start position:0% +function a function to use on our corpus +let's see what that did by looking at + + align:start position:0% +let's see what that did by looking at + + + align:start position:0% +let's see what that did by looking at +our first tweet again go ahead and hit + + align:start position:0% +our first tweet again go ahead and hit + + + align:start position:0% +our first tweet again go ahead and hit +the up arrow twice to get back to corpus + + align:start position:0% +the up arrow twice to get back to corpus + + + align:start position:0% +the up arrow twice to get back to corpus +1 and now we can see that all of our + + align:start position:0% +1 and now we can see that all of our + + + align:start position:0% +1 and now we can see that all of our +letters are lowercase now let's remove + + align:start position:0% +letters are lowercase now let's remove + + + align:start position:0% +letters are lowercase now let's remove +all punctuation this is done in a very + + align:start position:0% +all punctuation this is done in a very + + + align:start position:0% +all punctuation this is done in a very +similar way except this time we give the + + align:start position:0% +similar way except this time we give the + + + align:start position:0% +similar way except this time we give the +argument remove punctuation instead of + + align:start position:0% +argument remove punctuation instead of + + + align:start position:0% +argument remove punctuation instead of +to lower hit the up arrow twice and in + + align:start position:0% +to lower hit the up arrow twice and in + + + align:start position:0% +to lower hit the up arrow twice and in +the TM map function delete to lower and + + align:start position:0% +the TM map function delete to lower and + + + align:start position:0% +the TM map function delete to lower and +type remove punctuation let's see what + + align:start position:0% +type remove punctuation let's see what + + + align:start position:0% +type remove punctuation let's see what +this did to our first tweet again now + + align:start position:0% +this did to our first tweet again now + + + align:start position:0% +this did to our first tweet again now +the comma after say the exclamation + + align:start position:0% +the comma after say the exclamation + + + align:start position:0% +the comma after say the exclamation +point after received and the @ symbols + + align:start position:0% +point after received and the @ symbols + + + align:start position:0% +point after received and the @ symbols +before Apple are all gone now we want to + + align:start position:0% +before Apple are all gone now we want to + + + align:start position:0% +before Apple are all gone now we want to +remove the stop words in our tweets TM + + align:start position:0% +remove the stop words in our tweets TM + + + align:start position:0% +remove the stop words in our tweets TM +provides a list of stop words for the + + align:start position:0% +provides a list of stop words for the + + + align:start position:0% +provides a list of stop words for the +English language we can check it out by + + align:start position:0% +English language we can check it out by + + + align:start position:0% +English language we can check it out by +typing stop words and then in + + align:start position:0% +typing stop words and then in + + + align:start position:0% +typing stop words and then in +parenthesis in quotes English and then + + align:start position:0% +parenthesis in quotes English and then + + + align:start position:0% +parenthesis in quotes English and then +we'll look at the 1st through the 10th + + align:start position:0% +we'll look at the 1st through the 10th + + + align:start position:0% +we'll look at the 1st through the 10th +stop words we see that these are words + + align:start position:0% +stop words we see that these are words + + + align:start position:0% +stop words we see that these are words +like I me my myself etc removing words + + align:start position:0% +like I me my myself etc removing words + + + align:start position:0% +like I me my myself etc removing words +can be done with a remove words argument + + align:start position:0% +can be done with a remove words argument + + + align:start position:0% +can be done with a remove words argument +to the TM map function but we need one + + align:start position:0% +to the TM map function but we need one + + + align:start position:0% +to the TM map function but we need one +extra argument this time what the stop + + align:start position:0% +extra argument this time what the stop + + + align:start position:0% +extra argument this time what the stop +words are that we want to remove will + + align:start position:0% +words are that we want to remove will + + + align:start position:0% +words are that we want to remove will +remove all of these English stop words + + align:start position:0% +remove all of these English stop words + + + align:start position:0% +remove all of these English stop words +but will also remove the word Apple + + align:start position:0% +but will also remove the word Apple + + + align:start position:0% +but will also remove the word Apple +since all of these tweets have the word + + align:start position:0% +since all of these tweets have the word + + + align:start position:0% +since all of these tweets have the word +Apple and it probably won't be very + + align:start position:0% +Apple and it probably won't be very + + + align:start position:0% +Apple and it probably won't be very +useful in our prediction problem + + align:start position:0% +useful in our prediction problem + + + align:start position:0% +useful in our prediction problem +so go ahead and hit the up arrow to get + + align:start position:0% +so go ahead and hit the up arrow to get + + + align:start position:0% +so go ahead and hit the up arrow to get +back to the TMF function delete remove + + align:start position:0% +back to the TMF function delete remove + + + align:start position:0% +back to the TMF function delete remove +punctuation and instead type remove + + align:start position:0% +punctuation and instead type remove + + + align:start position:0% +punctuation and instead type remove +words then we need to add one extra + + align:start position:0% +words then we need to add one extra + + + align:start position:0% +words then we need to add one extra +argument C and then in parenthesis and + + align:start position:0% +argument C and then in parenthesis and + + + align:start position:0% +argument C and then in parenthesis and +in quotes Apple this is us removing the + + align:start position:0% +in quotes Apple this is us removing the + + + align:start position:0% +in quotes Apple this is us removing the +word Apple and then stop words + + align:start position:0% +word Apple and then stop words + + + align:start position:0% +word Apple and then stop words +parenthesis in quotes English so this + + align:start position:0% +parenthesis in quotes English so this + + + align:start position:0% +parenthesis in quotes English so this +will remove the word Apple and all of + + align:start position:0% +will remove the word Apple and all of + + + align:start position:0% +will remove the word Apple and all of +the English stop words let's take a look + + align:start position:0% +the English stop words let's take a look + + + align:start position:0% +the English stop words let's take a look +at our first tweet again to see what + + align:start position:0% +at our first tweet again to see what + + + align:start position:0% +at our first tweet again to see what +happened now we can see that we have + + align:start position:0% +happened now we can see that we have + + + align:start position:0% +happened now we can see that we have +significantly fewer words only the words + + align:start position:0% +significantly fewer words only the words + + + align:start position:0% +significantly fewer words only the words +that are not stop words lastly we want + + align:start position:0% +that are not stop words lastly we want + + + align:start position:0% +that are not stop words lastly we want +to stim our document with the stim + + align:start position:0% +to stim our document with the stim + + + align:start position:0% +to stim our document with the stim +document argument go ahead and scroll + + align:start position:0% +document argument go ahead and scroll + + + align:start position:0% +document argument go ahead and scroll +back up to the remove punctuation delete + + align:start position:0% +back up to the remove punctuation delete + + + align:start position:0% +back up to the remove punctuation delete +remove punctuation and type stim + + align:start position:0% +remove punctuation and type stim + + + align:start position:0% +remove punctuation and type stim +document if you hit enter and then look + + align:start position:0% +document if you hit enter and then look + + + align:start position:0% +document if you hit enter and then look +at the first tweet again we can see that + + align:start position:0% +at the first tweet again we can see that + + + align:start position:0% +at the first tweet again we can see that +this took off the ending of customer + + align:start position:0% +this took off the ending of customer + + + align:start position:0% +this took off the ending of customer +service received an app store in the + + align:start position:0% +service received an app store in the + + + align:start position:0% +service received an app store in the +next video we'll investigate our corpus + + align:start position:0% +next video we'll investigate our corpus + + + align:start position:0% +next video we'll investigate our corpus +and prepare it for our prediction + + align:start position:0% +and prepare it for our prediction + + + align:start position:0% +and prepare it for our prediction +problem \ No newline at end of file diff --git a/G0iYkb9YiRg.txt b/G0iYkb9YiRg.txt new file mode 100644 index 0000000000000000000000000000000000000000..56c429d8b3d159e1d7cee754499869cd348cc48d --- /dev/null +++ b/G0iYkb9YiRg.txt @@ -0,0 +1,1478 @@ +The following content is +provided under a Creative + +Commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high quality educational +resources for free. + +To make a donation or view +additional materials from + +hundreds of MIT courses, visit +MIT OpenCourseWare at + +ocw.mit.edu. + +PROFESSOR: So I will go into a +little about what the class + +is, and what you're +going to do. + +I'll just put one slide about +requirements and outcomes. + +So what are the requirements? + +We require you to be a good +programmer with a lot of + +programming experience. + +As I said, we are going down +to very bare metal. + +And there won't be any +niceties of just + +writing Java code. + +So you're going to run into a +lot of these kind of issues. + +Fluent in C is -- + +I wouldn't call it a 100% +requirement, but it really + +helps if you're fluent in C. +If not, you'll have to + +probably spend a lot of time +trying to understand C, C++. + +And in this class that means -- +just start doing it today, + +just get a C book and then +try to understand. + +If you run a lot of Java it +might be an easy transition. + +But get to the transition +fast, don't wait. + +What are we expecting +at the end? + +We expect at the end +for you to know -- + +AUDIENCE: I have to go. + +Thank you very much +[INAUDIBLE] + +PROFESSOR: So what +do we expect? + +We expect at the end you'll +probably understand a lot of + +fundamentals and concepts of +parallel programming -- + +both hardware and software. + +Because the nice +thing about -- + +or the nice thing or the +bad thing about Cell -- + +is a lot of hardware conceptuals +to expose. + +There's no nice abstraction +layers in there. + +You'll understand a lot of +issues about parallel + +performance. + +We started here, you write a +program, compile -- it's not + +just order n you're +looking for. + +You're looking for all +these constants. + +All these things matter, +basically. + +You should be able to synthesize +a fairly complex + +parallel program by the end, +because that's what your group + +project's going to be. + +And you'll get a lot of hands-on +experience with the + +Cell processor, so we'll +understand this one + +instance very well. + +So that is what we are expecting +will happen at the + +end of this 3.5 weeks. + +So the project. + +You proposed the projects, we +did something different. + +So it's all your ideas that +we are going to do. + +We selected seven groups out +of these -- there are seven + +projects in there -- + +mainly based on the strength +of the project proposals. + +And I was pretty impressed with +the height of things you + +guys proposed. + +So here are the seven +projects. + +Let's actually try to figure +out who's who. + +Who's doing distributed +real-time ray tracer? + +OK, that's not true. + +OK, how about the global +illumination? + +OK. + +Linear algebra pack? + +OK, good. + +Molecular dynamics? + +OK. + +Speech synthesizer? + +OK. + +Soft radio? + +OK. + +Backgammon tutor? + +OK. + +And there are some people who +are, I think, in this class + +thinking that they +can join a group. + +So at the end, there are a few +groups that only have one + +member, so probably go ahead +and talk to them and see + +whether they are willing +to work with people. + +So I'll give you a little bit of +time, because I'm going to + +finish early. + +OK, let's ask -- who are +the people who are + +hoping to join a group? + +Is there anybody who came? + +I got a few emails, I don't +know that anybody's here. + +Oh good. + +So it's not going +to be a problem. + +So I did the project +characteristics. + +You can see that they are +ambitious projects, but + +accomplishable. + +I was worried that people would +say, "I'm going to build + +this entire thing", and it's +going to take a year. + +But I think most of the projects +that they proposed + +are doable. + +Another thing is important +and relevant things. + +I think for a lot of these +things, if the code is done + +right other people might +even use it. + +I think this can start +something, it's not just going + +to be this project. + +And there's a lot of opportunity +to sizzle. + +I think some people will come +up with these things that I + +think at the end will +be so amazing. + +And that's what got +me excited. + +But get them started as soon as +possible, because this is + +not a semester course, this is +going to run so fast. There's + +only a few all nighters +you can pull, + +basically is what it is. + +So there's a note of caution. + +Cell processor is very new. + +We heard about that today. + +I mean this is a really +cool thing, but it has + +its problems in there. + +It's not an easy architecture +to work with. + +There is though this +nice abstraction. + +So it's just then from this +being completely abstracted + +out, writing Java code, to +all the way to metal. + +So it's just almost a jump +from going to a higher + +language of assembly. + +So there's a huge, big gap in +there, and that's going to be + +a lot of issues in there. + +The tool chain is very +thin and brittle. + +So my pointing out all those +things, you wish there's a + +tool, but there's nothing. + +And even the existing tools -- + +we just got the SDK 2.0 into +working I think this morning + +-- and so there might +be issues in there. + +Most of the staff have +limited experience. + +For example, SDK 2.0. + +We just got it working, so we +haven't used it yet in there. + +So that can create problems, +especially in + +a fast moving course. + +The projects you are doing +are of your own making. + +Most of the classes -- + +if you need to [UNINTELLIGIBLE] + +classes, we actually come up +with the projects, TAs go and + +implement it once, we know +all the gotchas. + +And then when you get the +project we know there's an + +existence proof that +it's doable, it + +works, the tools work. + +We know at least there's +one path through it. + +There's nothing like +that here. + +Everybody's kind of just jumping +at it head on, and + +hoping that we can read them. + +And we might find issues that +are very hard, and that's why + +we actually have very +close contact with + +those guys at IBM. + +So if things happen, we'll call +them and they will be + +available to help us. + +But it's not something you can +say -- oh yeah, I know, just + +go do that. + +Or -- here's the way out. + +So there might be issues like +that, so we have to be very + +careful of that. + +And you will face these kinds of +problems. That's more given + +than anything else, so +be ready for that. + +This is not just writing some +high level code and getting + +away with it. + +And you're all in +this together. + +So the staff, you, +me, everybody -- + +we're just doing it for the +first time in some sense. + +And that's the fun part about +it, because as you pointed + +out, there might be some stuff +that you guys come out with + +that will become more like +folklore and the basis for the + +things people do. + +Because you might say -- +hey, there's a neat + +way of doing that. + +You will be the first to +do this kind of thing. + +So there's that time, but on +planning the three week course + +it's a large chunk to bite. + +If it is more for a PhD, +then you can say -- + +OK, spend three months +figuring it out. + +There's no other time limit. + +So we will try to manage this +process, but you need to try + +to -- expectations of what you +are trying to get done, and + +then be able to get it done. + +So you have to always +balance this out. + +If you're running into issues, +get to us very fast. Because + +we need to figure it out. + +And we might have to actually +also figure it out from + +somebody else, so we can +escalate it up and get the + +information. + +Because three weeks are +going to go so fast. + +How many people are taking +the class for a grade? + +So people who are taking it for +a grade, here is what we + +are going to do. + +The first thing, what I call +mini quizzes, is just a prop + +so you will come into class. + +So the way I am going to do that +is, at the beginning of + +the class I am going to give you +a piece of paper with two + +questions from the +previous lecture. + +You can do anything you +want to answer it. + +You can talk to people, +look it up, whatever. + +And then at the end +of the class + +basically we want it back. + +And the only requirement is, you +have to come individually + +to pick your thing up, and you +have to come individually to + +hand it in, and you can't write +somebody else's anwers + +physically, but you can +talk to each other. + +So we'll try to make it a little +bit entertaining, and a + +little bit thought-provoking, +but nothing like you have to + +spend hours doing it. + +It'll be probably +five minutes. + +Normally we will do a break +inbetween, so you probably can + +talk to each other and come up +with some of the answers. + +So this is just the fact that +the people who are actually + +getting the grades will be +coming to class, more than + +anything else I'll be testing. + +And then we have these lab +projects at the beginning, + +that will get some grade. + +And the final group project. + +And then we have a final +competition. + +So since everybody's not doing +the same project, we are going + +to decide on performance -- + +so how well your code ran, how +much MIPS or [? GOPs ?] you + +were able to get from that. + +And how raw performance +is in there. + +And then we will also +look at it from a + +complexity point of view. + +So for example, as I pointed +out, if you do matrix + +multiplier you get certain +performance, so if you do + +[? FF3, ?] you get certain +performance. + +So just absolute numbers is not +what matters, but how far + +you can get hard +algorithm too. + +Completeness. + +So were you able to get +your project through? + +How much do you actually have a +compete solution at the end + +that something works? + +That's important. + +Algorithmic complexity -- how +much of a complexity did you + +bite in, both from more of a +pure algorithm point of view, + +and also implementing some +shared complexity in there. + +And demo and presentation. + +So OK, those two. + +So we are going to select +a winning team. + +We haven't figured exactly what, +but we'll give everybody + +a gift set depending on -- + +this is what we are aiming +at right now. + +Also we are going to invite the +winning team to spend a + +day at IBM TJ Watson. + +You get to give a presentation +to a bunch of people there, + +and probably go see what +they are doing. + +That should be a fun +day to spend. + +We haven't scheduled a day, +depending on the class + +schedule and stuff like that, +the winning team will go spend + +a day out in there. + +That will be a fun thing to +do, there's a lot of cool + +stuff going on there. + +They will get to actually +interact with some + +researchers, see what they +do, as well as present + +this work to them. + +And since this is new +everybody's excited. + +I think hopefully we'll come +up with a team that will do + +things that other people will be +interested in and will use. + +So these kind of come from +backward because I wanted to + +get Mike Perrone first. +So my name is Saman -- + +Saman Amarasinghe -- + +I live in CSAIL. + +I have had a lot of +interest in -- + +[LAUGHTER] + +Not as much as you +guys probably. + +I have a lot of interest in +languages, compilers, and + +computer architecture. + +So if you have been at this game +for a long time, in the + +early 1990s there was a huge +surge in parallel performance, + +work on parallelism, and at +that time I did the SUIF + +parallelizing compiler +in there. + +And then, everybody says -- hey, +there's this Moore slope + +of performance, who cares +about parallelism? + +So there was this decade +when this paralellism + +kind of died down. + +I kind of hid under the radar +and kind of survived through + +that thing, and then again I +think parallelism coming up. + +So we are doing a bunch of +parallel work in here. + +So I probably have a perspective +that goes + +somewhere old, and +then coming up. + +Probably Aaron can also +relate to that. + +Aaron: There's one of +us who did that. + +PROFESSOR: Yeah exactly. + +Going through that, kind +of survived in that. + +And Rodric is sitting there. + +So Rodric is right now at IBM +PJ Watson, but he's probably + +going to live at CSAIL next +month, so he's going to be + +here more than me in fact. + +He was actually in the lab until +a few months ago, as a + +research scientist. He's also +interested in a lot of these + +kinds of things -- compilers, +architecture, parallel + +architecture, and +FPGA type work. + +And then we have two TAs. + +Where's David and Phil? + +OK, get up. + +So they actually have +some experience. + +Probably they are about a week +ahead of you on understanding + +Cell, not too much. + +They are going to lead the +recitations and be available + +to help you in there. + +So really use those resources +as much as possible. + +And then we are going to have +a huge amount of guest + +lecturers, and I was pretty +happy with the + +kind of list we got. + +Mike Perrone just came and gave +you the lecture, and Alan + +is going to talk +in a few weeks. + +And Professor Arvind, Brad +Kuszmaul, Mike Acton -- that + +Mike Perrone talk about is +going to come at the end. + +And Bill Thies, who was one +of the PhD students in the + +Streamit group, is going +to talk about + +the Streamit language. + +So the way we have kind of +structured the class is, how + +do you go about extracting +parallelism. + +There's implicit parallelism. + +And sometimes the +current way of + +everything done by hardware. + +In the next lecture, I will just +touch upon superscalar + +hardware, what it is and +what its problems are. + +Implicit parallelism means +you can do by compiler. + +So you write a C program, and +let the compiler deal with the + +parallelism. + +For as long as you are a +programmer, you don't have to + +deal with that thing. + +In lectures 11 and 12 +I will talk about + +parallelizing compilers. + +So we'll cover how you can +do that [? in C. ?] + +So that means kind of abstract +it out, and leaving it out of + +the end programmer. + +So the hardware exposes it, but +we put a software layer. + +And then the other end is +explicit parallelism. + +That's where, I think, we are +going to spend most of the + +time in this class. + +So in the first part of explicit +parallelism is the + +library approach. + +What that means is you are using +MPI type things, so you + +are basically at the metal +dealing with this parallelism. + +I am going to do lecture +4 on concurrency. + +How many people took 6.170 last +year when I was teaching? + +OK. + +I did a lecture on concurrency +there, so something very + +similar I'm going to do in here +-- to get the basics of + +parallelism. + +In order to write a parallel +program, the program has to + +run concurrently. + +There's a lot of issues for +writing concurrent programs. + +It is necessary to get parallel, +it's not sufficient. + +There are a lot more other +things to worry about. + +But let's deal with those +kind of issues -- + +deal with things like +synchronization, deadlocks, + +and issues like that. + +So I'm going to give that, and +then Rodric is going to have a + +few lecture on design +patterns. + +So if you want to write a +parallel program, how do you + +look at it? + +Different algorithms will +have different ways of + +parallelizing. + +So he's going to go about +looking at these kind of + +parallel patterns. + +If you have this kind of +program, here is a + +way to look at it. + +Here's another way +to look at it. + +So kind of go through +that in there. + +And in concurrency we work +with a lot more abstract + +parallel model, and get slowly +down to all the realism needed + +in dealing with Cell. + +And then we are going to have +a bunch of guest lectures, + +mainly dealing with other ways +of doing parallelism. + +So this is one way. + +We are going to have a lecture +on Streamit, because you might + +be able to use that also +as a way on Cell. + +So a little bit of high +abstraction, we are trying to + +make that available on Cell. + +So if that comes to, then you +might be able to even have + +that as a part of your +toolbox in there. + +The other three talks are +about very different + +approaches for parallelism. + +I think they will give you a +big picture view, it's not + +that you're just going +through one + +parallelling down in there. + +I think at the end of to the day +you'll understand not only + +how to deal with Cell, but +kind of a general way of + +looking at parallelism, and +maybe from that approach + +[UNINTELLIGIBLE] parallelism +in there. + +So the lectures are organized +as follows. + +We are now at the end +of the day here. + +Tomorrow we'll have +a recitation on + +getting to know Cell. + +We are trying to figure out a +good room, so just check your + +email to figure out exactly +where we are going to have it, + +because we are trying +to figure it out. + +We want to find a room with +machines so everybody can + +actualy get hands-on experience +in kind of a + +lecture format. + +And then we will have the +architecture, just general + +parallel architecture, and an +introduction to concurrent + +programming. + +And then Rodric is going to +have individual meets with + +individual groups, +trying to get the + +groups' projects going. + +So at that point kind of figure +out how we are doing + +it, have some early ideas about +it so you can start + +thinking and start the process +of doing that. + +You can start working on Cell +probably from tomorrow, but + +really get a day to kind of +get familiarized, and then + +here start the project. + +And then we will have +some lectures on + +design patterns in here. + +And as we go we'll have more +hands-on experience also. + +Then we'll have a lecture +on Streamit. + +So if you are using Streamit for +a part of the run program, + +you'll be able to understand +what's going on. + +And we'll get to some debugging +tools, hopefully we + +will have to deal with these +things before that, but here's + +something that if you're really +stuck, to get a breadth + +of tools available in here. + +And then we'll talk in general +about debugging and + +performance monitoring and +performance optimization. + +So at this point hopefully you +have done the first cart, you + +have figured out what problems, +and start optimizing + +things in here. + +And then we'll going into a +little bit more breadth, + +things like traffic paralleizing +compilers that I + +talk about, getting implicit +parallelism in here. + +And then we will have a bunch of +guest lecturers coming in. + +And we'll talk about some +hardware and the future, + +because we are just starting +this very new phase in + +programming that might change +almost everybody. + +Five years, ten years down the +line if you go through + +computer science, you might have +a very different flavor, + +if what people think of +parallelism takes hold. + +So let's look at some future, +and talk about that. + +And it's a nice way to +finish the lectures. + +A few more days and then +we'll have group + +presentations in here. + +So each group will get about +15 minutes time to present + +what they have done and give +a little bit of a demo. + +And then finally on +Friday we will + +have awards and reception. + +So this is what we got. + +Any questions? + +AUDIENCE: For recitations, if +we're not in a room with + +machines should we +bring laptops? + +PROFESSOR: So that's +a good question. + +Who doesn't have a laptop +they can bring? + +OK. + +If that is the case, we can have +it in any room we want, + +and have the network. + +And we might have one or two +additional machines for people + +who don't have a laptop. + +And that actually will work +much better than everybody + +marching into some kind of a +computer room that's not + +structured properly +for doing a class. + +OK, that actually helps a lot. + +That's a good point, I think +that helps a lot. + +OK, we'll do that +that way then. + +AUDIENCE: How do we get access +to these machines? + +PROFESSOR: OK. + +Rodric, you -- + +RODRIC RABBAH: Every room has +a PS3 dedicated to them. + +And every group has accounts +on their dedicated PS3. + +I have your usernames +and passwords. + +I will pass them out tomorrow, +because I'm going to propagate + +the new SDK to all the PS3's -- +to sort of test it with one + +and make sure everything's +working. + +So you'll get them at the first +recitation tomorrow. + +Unless you really want them +today, then come talk to me or + +send me email. + +PROFESSOR: You'll get +to take home -- + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: Yes. + +RODRIC RABBAH: Yes. + +PROFESSOR: We couldn't even put +it in the machine room, + +because they were scared +somebody was going + +to take them home. + +So we actually have it in a +different room -- closed, + +nicely locked -- + +or on the network. + +So I have been a very popular +person lately, a lot of people + +have tried to bribe me +to get access to + +one of these masters. + +AUDIENCE: [UNINTELLIGIBLE] + +AUDIENCE: How much does +the PS3 cost? + +PROFESSOR: Officially $600, but +then eBay's going up to + +like $2,500 these days. + +AUDIENCE: No. + +PROFESSOR: That's gone down? + +AUDIENCE: They're down between +$400 and $500. + +PROFESSOR: Oh, OK. + +AUDIENCE: They tried +[? to rope me in. ?] + +[LAUGHTER] + +PROFESSOR: OK. + +But during Christmas +it was down for -- + +a few desperate payers who +were trying to bribe me. + +[LAUGHTER] + +So I guess their volume +has caught up to -- + +AUDIENCE: No, the demand +has dropped. + +PROFESSOR: OK. + +AUDIENCE: [INAUDIBLE] + +AUDIENCE: Will we get to +see the Playstation? + +PROFESSOR: Tomorrow we +can bring one -- + +AUDIENCE: I can bring +one [INAUDIBLE] + +PROFESSOR: If you put +a game in it's fun. + +You can put a game in and play +it, but this is going to be + +Linux so it's a little +bit boring. + +[LAUGHTER] + +AUDIENCE: So these are +things that actually + +cannot play the games. + +PROFESSOR: It can. + +Interestingly, mostly these +game machines are sold for + +less than production value. + +So Microsoft, Nintendo, and +Sony before made sure that + +nobody can run anything other +than the published games that + +they've charged $25 per pop to + +recover the cost. Huh? + +No, $60 for the game. + +I think they are charging $25 +from the game maker just for + +the privilege of running +the game. + +That's how they make +their money. + +But, [UNINTELLIGIBLE] + +when they made PS3 bootable +by Linux. + +So in fact, it's much cheaper, +you get a Blu-Ray player, and + +this Cell processor for a lot +less than the production cost. + +AUDIENCE: Does Linux on +the PS3 run on top + +of the PS3 OS though? + +PROFESSOR: No. + +It just boots up PS3. + +What it does is in fact -- + +right now, you don't get +access to the graphics + +processor properly. + +So you can run open G11. + +You have framebuffer access, +but you don't get the full + +graphics access out of that. + +AUDIENCE: Which distribution +are we using? + +PROFESSOR: Which one? + +AUDIENCE: We're using +Yellow Dog. + +AUDIENCE: So in other words, +Mario and Luigi are + +subsidizing what we're +going to do. + +[LAUGHTER] + +PROFESSOR: Yeah, exactly. + +All those shoot them up games +are basically what subsidizes. + +Actually he said, in one sense, +you get the processor + +down to $200 because they are +selling all the other things. + +And the other thing, actually +if you want to build a high + +performance Cell farm, it's +probably cheaper because I + +think that the Cell blend +would be $2,000. + +It should be cheaper to +buy a bunch of PS3's, + +connect them together. + +But there might be issues about +things like network + +access, file access, because as +you pointed out, the board + +access is pretty primitive. + +Because for games you don't +need this high bandwidth + +connection, you just need +to download it once. + +So there might be issues +using it for cluster. + +OK. + +Anything else? + +OK, good. \ No newline at end of file diff --git a/G6bUKW3S_Us.txt b/G6bUKW3S_Us.txt new file mode 100644 index 0000000000000000000000000000000000000000..3a2fb1a0c4517fe6a9f1852c18ff6828b38a14ec --- /dev/null +++ b/G6bUKW3S_Us.txt @@ -0,0 +1,17259 @@ +align:start position:0% + +foreign + + align:start position:0% + + + + align:start position:0% + +we spent a lot of + + align:start position:0% +we spent a lot of + + + align:start position:0% +we spent a lot of +the last few lectures going through some + + align:start position:0% +the last few lectures going through some + + + align:start position:0% +the last few lectures going through some +substancing but also going to a lot of + + align:start position:0% +substancing but also going to a lot of + + + align:start position:0% +substancing but also going to a lot of +methodology + + align:start position:0% +methodology + + + align:start position:0% +methodology +so I thought that today we have kind of + + align:start position:0% +so I thought that today we have kind of + + + align:start position:0% +so I thought that today we have kind of +on the right to uh go to be deep longer + + align:start position:0% +on the right to uh go to be deep longer + + + align:start position:0% +on the right to uh go to be deep longer +on substance and shorter on methodology + + align:start position:0% +on substance and shorter on methodology + + + align:start position:0% +on substance and shorter on methodology +so what I'm going to do is a bit of an + + align:start position:0% +so what I'm going to do is a bit of an + + + align:start position:0% +so what I'm going to do is a bit of an +overview + + align:start position:0% +overview + + + align:start position:0% +overview +of what we have learned over the years + + align:start position:0% +of what we have learned over the years + + + align:start position:0% +of what we have learned over the years +and on + + align:start position:0% +and on + + + align:start position:0% +and on +the education systems and you know what + + align:start position:0% +the education systems and you know what + + + align:start position:0% +the education systems and you know what +is wrong with them if you remember in + + align:start position:0% +is wrong with them if you remember in + + + align:start position:0% +is wrong with them if you remember in +our first lecture I showed you some + + align:start position:0% +our first lecture I showed you some + + + align:start position:0% +our first lecture I showed you some +some numbers on what kids know and + + align:start position:0% +some numbers on what kids know and + + + align:start position:0% +some numbers on what kids know and +basically that's kind of the central + + align:start position:0% +basically that's kind of the central + + + align:start position:0% +basically that's kind of the central +puzzle I'm going to to study today so + + align:start position:0% +puzzle I'm going to to study today so + + + align:start position:0% +puzzle I'm going to to study today so +there is a lot because + + align:start position:0% +there is a lot because + + + align:start position:0% +there is a lot because +I think for + + align:start position:0% +I think for + + + align:start position:0% +I think for +practical reasons it turns out that it's + + align:start position:0% +practical reasons it turns out that it's + + + align:start position:0% +practical reasons it turns out that it's +relatively easy to experiment on kids + + align:start position:0% +relatively easy to experiment on kids + + + align:start position:0% +relatively easy to experiment on kids +because they are your captive audience + + align:start position:0% +because they are your captive audience + + + align:start position:0% +because they are your captive audience +and classrooms so a lot of the movement + + align:start position:0% +and classrooms so a lot of the movement + + + align:start position:0% +and classrooms so a lot of the movement +of running randomized control trials + + align:start position:0% +of running randomized control trials + + + align:start position:0% +of running randomized control trials +started on school on on asking questions + + align:start position:0% +started on school on on asking questions + + + align:start position:0% +started on school on on asking questions +on school quality + + align:start position:0% +on school quality + + + align:start position:0% +on school quality +so this is really one area where you can + + align:start position:0% +so this is really one area where you can + + + align:start position:0% +so this is really one area where you can +go beyond a single well-identified study + + align:start position:0% +go beyond a single well-identified study + + + align:start position:0% +go beyond a single well-identified study +tells you a thing to step back and think + + align:start position:0% +tells you a thing to step back and think + + + align:start position:0% +tells you a thing to step back and think +you know how does the whole picture look + + align:start position:0% +you know how does the whole picture look + + + align:start position:0% +you know how does the whole picture look +like and where issues of + + align:start position:0% +like and where issues of + + + align:start position:0% +like and where issues of +external validity and this data and the + + align:start position:0% +external validity and this data and the + + + align:start position:0% +external validity and this data and the +other applies less because it's not that + + align:start position:0% +other applies less because it's not that + + + align:start position:0% +other applies less because it's not that +you're interested in each of the points + + align:start position:0% +you're interested in each of the points + + + align:start position:0% +you're interested in each of the points +specifically because how the whole + + align:start position:0% +specifically because how the whole + + + align:start position:0% +specifically because how the whole +picture fits together and in some + + align:start position:0% +picture fits together and in some + + + align:start position:0% +picture fits together and in some +areas we we are not at this point yet we + + align:start position:0% +areas we we are not at this point yet we + + + align:start position:0% +areas we we are not at this point yet we +are kind of we have a disparate sets of + + align:start position:0% +are kind of we have a disparate sets of + + + align:start position:0% +are kind of we have a disparate sets of +facts I think the economics of a family + + align:start position:0% +facts I think the economics of a family + + + align:start position:0% +facts I think the economics of a family +gender is a little bit like that where + + align:start position:0% +gender is a little bit like that where + + + align:start position:0% +gender is a little bit like that where +we are still trying trying to feel our + + align:start position:0% +we are still trying trying to feel our + + + align:start position:0% +we are still trying trying to feel our +way around uh by uh looking at various + + align:start position:0% +way around uh by uh looking at various + + + align:start position:0% +way around uh by uh looking at various +case studying various things but the + + align:start position:0% +case studying various things but the + + + align:start position:0% +case studying various things but the +education one is one education Supply + + align:start position:0% +education one is one education Supply + + + align:start position:0% +education one is one education Supply +the quality of education is really where + + align:start position:0% +the quality of education is really where + + + align:start position:0% +the quality of education is really where +one place where we have mercy + + align:start position:0% +one place where we have mercy + + + align:start position:0% +one place where we have mercy +so I thought I would take advantage of + + align:start position:0% +so I thought I would take advantage of + + + align:start position:0% +so I thought I would take advantage of +that to to to do one more of these + + align:start position:0% +that to to to do one more of these + + + align:start position:0% +that to to to do one more of these +overview lectures instead of drilling + + align:start position:0% +overview lectures instead of drilling + + + align:start position:0% +overview lectures instead of drilling +down in details on + + align:start position:0% +down in details on + + + align:start position:0% +down in details on +what would have been for today which is + + align:start position:0% +what would have been for today which is + + + align:start position:0% +what would have been for today which is +uh some regression discontinuity design + + align:start position:0% +uh some regression discontinuity design + + + align:start position:0% +uh some regression discontinuity design +so we'll have to find another time to uh + + align:start position:0% +so we'll have to find another time to uh + + + align:start position:0% +so we'll have to find another time to uh +for an example on rdd or maybe do it in + + align:start position:0% +for an example on rdd or maybe do it in + + + align:start position:0% +for an example on rdd or maybe do it in +restitution + + align:start position:0% +restitution + + + align:start position:0% +restitution +uh so obviously it's useful to put that + + align:start position:0% +uh so obviously it's useful to put that + + + align:start position:0% +uh so obviously it's useful to put that +in context of the covid-19 pandemic + + align:start position:0% +in context of the covid-19 pandemic + + + align:start position:0% +in context of the covid-19 pandemic +because it's a real like it's a total + + align:start position:0% +because it's a real like it's a total + + + align:start position:0% +because it's a real like it's a total +tsunami on the education system in + + align:start position:0% +tsunami on the education system in + + + align:start position:0% +tsunami on the education system in +developing countries in developed + + align:start position:0% +developing countries in developed + + + align:start position:0% +developing countries in developed +countries as well obviously in the U.S a + + align:start position:0% +countries as well obviously in the U.S a + + + align:start position:0% +countries as well obviously in the U.S a +lot of kids stayed out of school for + + align:start position:0% +lot of kids stayed out of school for + + + align:start position:0% +lot of kids stayed out of school for +more than a year but + + align:start position:0% +more than a year but + + + align:start position:0% +more than a year but +worldwide 300 million children have been + + align:start position:0% +worldwide 300 million children have been + + + align:start position:0% +worldwide 300 million children have been +affected by school closures + + align:start position:0% +affected by school closures + + + align:start position:0% +affected by school closures +and in many countries the schools are + + align:start position:0% +and in many countries the schools are + + + align:start position:0% +and in many countries the schools are +yet to reopen in India for example it's + + align:start position:0% +yet to reopen in India for example it's + + + align:start position:0% +yet to reopen in India for example it's +mostly not reopened so as of today as + + align:start position:0% +mostly not reopened so as of today as + + + align:start position:0% +mostly not reopened so as of today as +most of the kids know in which countries + + align:start position:0% +most of the kids know in which countries + + + align:start position:0% +most of the kids know in which countries +are back in schools they are still 128 + + align:start position:0% +are back in schools they are still 128 + + + align:start position:0% +are back in schools they are still 128 +millions of the kids who are still + + align:start position:0% +millions of the kids who are still + + + align:start position:0% +millions of the kids who are still +affected that should be the end of + + align:start position:0% +affected that should be the end of + + + align:start position:0% +affected that should be the end of +September of 2021 + + align:start position:0% +September of 2021 + + + align:start position:0% +September of 2021 +who have not gone back to school and + + align:start position:0% +who have not gone back to school and + + + align:start position:0% +who have not gone back to school and +they are now all in in poor countries + + align:start position:0% +they are now all in in poor countries + + + align:start position:0% +they are now all in in poor countries +so + + align:start position:0% +so + + + align:start position:0% +so +um that's a big + + align:start position:0% +um that's a big + + + align:start position:0% +um that's a big +and perhaps not surprisingly but it's + + align:start position:0% +and perhaps not surprisingly but it's + + + align:start position:0% +and perhaps not surprisingly but it's +been actually immersion it has + + align:start position:0% +been actually immersion it has + + + align:start position:0% +been actually immersion it has +catastrophic impact on on learning + + align:start position:0% +catastrophic impact on on learning + + + align:start position:0% +catastrophic impact on on learning +levels + + align:start position:0% +levels + + + align:start position:0% +levels +even in the short run what you can see + + align:start position:0% +even in the short run what you can see + + + align:start position:0% +even in the short run what you can see +is that for example so this is the data + + align:start position:0% +is that for example so this is the data + + + align:start position:0% +is that for example so this is the data +from Pata that looks at + + align:start position:0% +from Pata that looks at + + + align:start position:0% +from Pata that looks at +that uses their simple assert test to + + align:start position:0% +that uses their simple assert test to + + + align:start position:0% +that uses their simple assert test to +the simple measure tool for measuring + + align:start position:0% +the simple measure tool for measuring + + + align:start position:0% +the simple measure tool for measuring +reading and Mathematics ability looking + + align:start position:0% +reading and Mathematics ability looking + + + align:start position:0% +reading and Mathematics ability looking +at arithmetic and I'll show you the + + align:start position:0% +at arithmetic and I'll show you the + + + align:start position:0% +at arithmetic and I'll show you the +reading in the next time uh so in 2018 + + align:start position:0% +reading in the next time uh so in 2018 + + + align:start position:0% +reading in the next time uh so in 2018 +and into 2021 a sample of about 28 20 + + align:start position:0% +and into 2021 a sample of about 28 20 + + + align:start position:0% +and into 2021 a sample of about 28 20 +000 kids that they had done in in 2018 + + align:start position:0% +000 kids that they had done in in 2018 + + + align:start position:0% +000 kids that they had done in in 2018 +were able to follow in 2021 + + align:start position:0% +were able to follow in 2021 + + + align:start position:0% +were able to follow in 2021 +and what we have here is uh already in + + align:start position:0% +and what we have here is uh already in + + + align:start position:0% +and what we have here is uh already in +the best of time it's not that good if + + align:start position:0% +the best of time it's not that good if + + + align:start position:0% +the best of time it's not that good if +you take this the kids in standard five + + align:start position:0% +you take this the kids in standard five + + + align:start position:0% +you take this the kids in standard five +for example uh the only uh 34 percent of + + align:start position:0% +for example uh the only uh 34 percent of + + + align:start position:0% +for example uh the only uh 34 percent of +them can do a division okay just a + + align:start position:0% +them can do a division okay just a + + + align:start position:0% +them can do a division okay just a +division at that at the division level + + align:start position:0% +division at that at the division level + + + align:start position:0% +division at that at the division level +so another 20 percent are one level + + align:start position:0% +so another 20 percent are one level + + + align:start position:0% +so another 20 percent are one level +above so about half of the kids can do + + align:start position:0% +above so about half of the kids can do + + + align:start position:0% +above so about half of the kids can do +so half of the kids little more than + + align:start position:0% +so half of the kids little more than + + + align:start position:0% +so half of the kids little more than +half of the kid can do at least a + + align:start position:0% +half of the kid can do at least a + + + align:start position:0% +half of the kid can do at least a +subtraction + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% +um + + + align:start position:0% +um +in in standard five a little less than + + align:start position:0% +in in standard five a little less than + + + align:start position:0% +in in standard five a little less than +half of the kid could do at least a + + align:start position:0% +half of the kid could do at least a + + + align:start position:0% +half of the kid could do at least a +subtraction in uh in standard four and + + align:start position:0% +subtraction in uh in standard four and + + + align:start position:0% +subtraction in uh in standard four and +it's an easy subtraction it's like a two + + align:start position:0% +it's an easy subtraction it's like a two + + + align:start position:0% +it's an easy subtraction it's like a two +digit minus two digit with carryover + + align:start position:0% +digit minus two digit with carryover + + + align:start position:0% +digit minus two digit with carryover +but then if we are looking at uh at this + + align:start position:0% +but then if we are looking at uh at this + + + align:start position:0% +but then if we are looking at uh at this +one now + + align:start position:0% +one now + + + align:start position:0% +one now +basically the standard five kids are now + + align:start position:0% +basically the standard five kids are now + + + align:start position:0% +basically the standard five kids are now +below 50 percent + + align:start position:0% +below 50 percent + + + align:start position:0% +below 50 percent +understand that four kids basically none + + align:start position:0% +understand that four kids basically none + + + align:start position:0% +understand that four kids basically none +of them are at division level almost so + + align:start position:0% +of them are at division level almost so + + + align:start position:0% +of them are at division level almost so +about a quarter of the key that's + + align:start position:0% +about a quarter of the key that's + + + align:start position:0% +about a quarter of the key that's +abstraction or above + + align:start position:0% +abstraction or above + + + align:start position:0% +abstraction or above +so we started from a low level and with + + align:start position:0% +so we started from a low level and with + + + align:start position:0% +so we started from a low level and with +the pandemic we have a catastrophically + + align:start position:0% +the pandemic we have a catastrophically + + + align:start position:0% +the pandemic we have a catastrophically +low level + + align:start position:0% +low level + + + align:start position:0% +low level +and of course we don't know how people + + align:start position:0% +and of course we don't know how people + + + align:start position:0% +and of course we don't know how people +will catch up but + + align:start position:0% +will catch up but + + + align:start position:0% +will catch up but +um + + align:start position:0% +um + + + align:start position:0% +um +it has been so slow any progress on + + align:start position:0% +it has been so slow any progress on + + + align:start position:0% +it has been so slow any progress on +quality of Education over the years has + + align:start position:0% +quality of Education over the years has + + + align:start position:0% +quality of Education over the years has +been so slow that a decline like that is + + align:start position:0% +been so slow that a decline like that is + + + align:start position:0% +been so slow that a decline like that is +going to be a big thing to to recover + + align:start position:0% +going to be a big thing to to recover + + + align:start position:0% +going to be a big thing to to recover +something in Reading so if you're + + align:start position:0% +something in Reading so if you're + + + align:start position:0% +something in Reading so if you're +looking for example at the the fraction + + align:start position:0% +looking for example at the the fraction + + + align:start position:0% +looking for example at the the fraction +of kids in in standard five uh who were + + align:start position:0% +of kids in in standard five uh who were + + + align:start position:0% +of kids in in standard five uh who were +at standard two level it was 46 percent + + align:start position:0% +at standard two level it was 46 percent + + + align:start position:0% +at standard two level it was 46 percent +before + + align:start position:0% +before + + + align:start position:0% +before +before the pandemic and it's at 34 + + align:start position:0% +before the pandemic and it's at 34 + + + align:start position:0% +before the pandemic and it's at 34 +percent + + align:start position:0% +percent + + + align:start position:0% +percent +at the time they did the server and + + align:start position:0% +at the time they did the server and + + + align:start position:0% +at the time they did the server and +since then these kids in Karnataka are + + align:start position:0% +since then these kids in Karnataka are + + + align:start position:0% +since then these kids in Karnataka are +still not in back in school + + align:start position:0% +still not in back in school + + + align:start position:0% +still not in back in school +so + + align:start position:0% +so + + + align:start position:0% +so +this is still a snapshot we don't know + + align:start position:0% +this is still a snapshot we don't know + + + align:start position:0% +this is still a snapshot we don't know +what's going to happen in the future as + + align:start position:0% +what's going to happen in the future as + + + align:start position:0% +what's going to happen in the future as +they go back to school but there are two + + align:start position:0% +they go back to school but there are two + + + align:start position:0% +they go back to school but there are two +things that are + + align:start position:0% +things that are + + + align:start position:0% +things that are +probably going to happen on the one hand + + align:start position:0% +probably going to happen on the one hand + + + align:start position:0% +probably going to happen on the one hand +a lot of the kids the older kids are + + align:start position:0% +a lot of the kids the older kids are + + + align:start position:0% +a lot of the kids the older kids are +just not going to go back at all + + align:start position:0% +just not going to go back at all + + + align:start position:0% +just not going to go back at all +to the reenoldment of teenagers + + align:start position:0% +to the reenoldment of teenagers + + + align:start position:0% +to the reenoldment of teenagers +presumably is going to be uh to be quite + + align:start position:0% +presumably is going to be uh to be quite + + + align:start position:0% +presumably is going to be uh to be quite +low so it's a you know it's a generation + + align:start position:0% +low so it's a you know it's a generation + + + align:start position:0% +low so it's a you know it's a generation +that is going to suffer an enormous + + align:start position:0% +that is going to suffer an enormous + + + align:start position:0% +that is going to suffer an enormous +amount I was talking to David Atkin who + + align:start position:0% +amount I was talking to David Atkin who + + + align:start position:0% +amount I was talking to David Atkin who +pointed out you know maybe the other it + + align:start position:0% +pointed out you know maybe the other it + + + align:start position:0% +pointed out you know maybe the other it +will kind of even out the other + + align:start position:0% +will kind of even out the other + + + align:start position:0% +will kind of even out the other +generation will be more educated so it's + + align:start position:0% +generation will be more educated so it's + + + align:start position:0% +generation will be more educated so it's +just this one generation maybe it's not + + align:start position:0% +just this one generation maybe it's not + + + align:start position:0% +just this one generation maybe it's not +that bad on aggregate that's going back + + align:start position:0% +that bad on aggregate that's going back + + + align:start position:0% +that bad on aggregate that's going back +to this equilibrium impact but for that + + align:start position:0% +to this equilibrium impact but for that + + + align:start position:0% +to this equilibrium impact but for that +generation it's certainly a disaster + + align:start position:0% +generation it's certainly a disaster + + + align:start position:0% +generation it's certainly a disaster +and then the other thing is that + + align:start position:0% +and then the other thing is that + + + align:start position:0% +and then the other thing is that +for the kids who will go back to school + + align:start position:0% +for the kids who will go back to school + + + align:start position:0% +for the kids who will go back to school +they will go back to school with a very + + align:start position:0% +they will go back to school with a very + + + align:start position:0% +they will go back to school with a very +different experiences + + align:start position:0% +different experiences + + + align:start position:0% +different experiences +with even more heterogeneity in levels + + align:start position:0% +with even more heterogeneity in levels + + + align:start position:0% +with even more heterogeneity in levels +that they started from + + align:start position:0% +that they started from + + + align:start position:0% +that they started from +because another thing of this that you + + align:start position:0% +because another thing of this that you + + + align:start position:0% +because another thing of this that you +see even from this simple test is not + + align:start position:0% +see even from this simple test is not + + + align:start position:0% +see even from this simple test is not +only the levels are low but the kids are + + align:start position:0% +only the levels are low but the kids are + + + align:start position:0% +only the levels are low but the kids are +all over the place + + align:start position:0% +all over the place + + + align:start position:0% +all over the place +some kids in standard one can read at + + align:start position:0% +some kids in standard one can read at + + + align:start position:0% +some kids in standard one can read at +standard two that very many a lot cannot + + align:start position:0% +standard two that very many a lot cannot + + + align:start position:0% +standard two that very many a lot cannot +even recognize the letters that's in + + align:start position:0% +even recognize the letters that's in + + + align:start position:0% +even recognize the letters that's in +normal time + + align:start position:0% +normal time + + + align:start position:0% +normal time +uh and then in in the after the pandemic + + align:start position:0% +uh and then in in the after the pandemic + + + align:start position:0% +uh and then in in the after the pandemic +that there is even more that cannot + + align:start position:0% +that there is even more that cannot + + + align:start position:0% +that there is even more that cannot +recognize the letters but there is still + + align:start position:0% +recognize the letters but there is still + + + align:start position:0% +recognize the letters but there is still +it's not kind of neatly organized around + + align:start position:0% +it's not kind of neatly organized around + + + align:start position:0% +it's not kind of neatly organized around +the diagonal so kids of the same age are + + align:start position:0% +the diagonal so kids of the same age are + + + align:start position:0% +the diagonal so kids of the same age are +very different uh arrive at different + + align:start position:0% +very different uh arrive at different + + + align:start position:0% +very different uh arrive at different +levels and that's uh that's true in 2018 + + align:start position:0% +levels and that's uh that's true in 2018 + + + align:start position:0% +levels and that's uh that's true in 2018 +that's even more true in 2021 and so + + align:start position:0% +that's even more true in 2021 and so + + + align:start position:0% +that's even more true in 2021 and so +that's something the school system will + + align:start position:0% +that's something the school system will + + + align:start position:0% +that's something the school system will +have to Grapple with + + align:start position:0% +have to Grapple with + + + align:start position:0% +have to Grapple with +but in some sense uh although I think + + align:start position:0% +but in some sense uh although I think + + + align:start position:0% +but in some sense uh although I think +this is a catastrophe and something that + + align:start position:0% +this is a catastrophe and something that + + + align:start position:0% +this is a catastrophe and something that +probably you guys some of you guys will + + align:start position:0% +probably you guys some of you guys will + + + align:start position:0% +probably you guys some of you guys will +want to study uh Salome is already kind + + align:start position:0% +want to study uh Salome is already kind + + + align:start position:0% +want to study uh Salome is already kind +of working on it in Mexico in the in the + + align:start position:0% +of working on it in Mexico in the in the + + + align:start position:0% +of working on it in Mexico in the in the +present but in the future as the + + align:start position:0% +present but in the future as the + + + align:start position:0% +present but in the future as the +pandemics subsides the question of how + + align:start position:0% +pandemics subsides the question of how + + + align:start position:0% +pandemics subsides the question of how +the vientry will takes place will will + + align:start position:0% +the vientry will takes place will will + + + align:start position:0% +the vientry will takes place will will +be pretty Central + + align:start position:0% +be pretty Central + + + align:start position:0% +be pretty Central +but but in some sense it's not new like + + align:start position:0% +but but in some sense it's not new like + + + align:start position:0% +but but in some sense it's not new like +in the U.S the the very much like in the + + align:start position:0% +in the U.S the the very much like in the + + + align:start position:0% +in the U.S the the very much like in the +U.S the the racial discrepancy in the + + align:start position:0% +U.S the the racial discrepancy in the + + + align:start position:0% +U.S the the racial discrepancy in the +burden of disease + + align:start position:0% +burden of disease + + + align:start position:0% +burden of disease +kind of put a magnifier on existing uh + + align:start position:0% +kind of put a magnifier on existing uh + + + align:start position:0% +kind of put a magnifier on existing uh +uh racial discrimination across any + + align:start position:0% +uh racial discrimination across any + + + align:start position:0% +uh racial discrimination across any +number of Dimensions that sort of + + align:start position:0% +number of Dimensions that sort of + + + align:start position:0% +number of Dimensions that sort of +collapsed in other coalescing to produce + + align:start position:0% +collapsed in other coalescing to produce + + + align:start position:0% +collapsed in other coalescing to produce +that outcome similarly this + + align:start position:0% +that outcome similarly this + + + align:start position:0% +that outcome similarly this +this + + align:start position:0% +this + + + align:start position:0% +this +drop in the level combined with + + align:start position:0% +drop in the level combined with + + + align:start position:0% +drop in the level combined with +increasing heterogeneity of experiences + + align:start position:0% +increasing heterogeneity of experiences + + + align:start position:0% +increasing heterogeneity of experiences +exacerbate existing trends + + align:start position:0% +exacerbate existing trends + + + align:start position:0% +exacerbate existing trends +and to China basically that you you find + + align:start position:0% +and to China basically that you you find + + + align:start position:0% +and to China basically that you you find +very high enrollment rates but a lot of + + align:start position:0% +very high enrollment rates but a lot of + + + align:start position:0% +very high enrollment rates but a lot of +absenteeism + + align:start position:0% +absenteeism + + + align:start position:0% +absenteeism +and very low learning levels + + align:start position:0% +and very low learning levels + + + align:start position:0% +and very low learning levels +so this is for India and then I'll show + + align:start position:0% +so this is for India and then I'll show + + + align:start position:0% +so this is for India and then I'll show +you the the world in the in the next + + align:start position:0% +you the the world in the in the next + + + align:start position:0% +you the the world in the in the next +slide this is a picture from 2014 but it + + align:start position:0% +slide this is a picture from 2014 but it + + + align:start position:0% +slide this is a picture from 2014 but it +you know post until the pandemic it was + + align:start position:0% +you know post until the pandemic it was + + + align:start position:0% +you know post until the pandemic it was +more or less correct most of the kids + + align:start position:0% +more or less correct most of the kids + + + align:start position:0% +more or less correct most of the kids +are on hold so 2014 you are 20 97 + + align:start position:0% +are on hold so 2014 you are 20 97 + + + align:start position:0% +are on hold so 2014 you are 20 97 +percent of kids enrolled in school + + align:start position:0% +percent of kids enrolled in school + + + align:start position:0% +percent of kids enrolled in school +this was the the sixth year in a row + + align:start position:0% +this was the the sixth year in a row + + + align:start position:0% +this was the the sixth year in a row +that enrollment had been at 96 or above + + align:start position:0% +that enrollment had been at 96 or above + + + align:start position:0% +that enrollment had been at 96 or above +so that's great but the attendance is + + align:start position:0% +so that's great but the attendance is + + + align:start position:0% +so that's great but the attendance is +not very good if you show up on any + + align:start position:0% +not very good if you show up on any + + + align:start position:0% +not very good if you show up on any +random day uh you find 71 percent of the + + align:start position:0% +random day uh you find 71 percent of the + + + align:start position:0% +random day uh you find 71 percent of the +children actually present and it's not + + align:start position:0% +children actually present and it's not + + + align:start position:0% +children actually present and it's not +always the same 71 percent so it means + + align:start position:0% +always the same 71 percent so it means + + + align:start position:0% +always the same 71 percent so it means +that like the the kids get between their + + align:start position:0% +that like the the kids get between their + + + align:start position:0% +that like the the kids get between their +own absences and the absences of the + + align:start position:0% +own absences and the absences of the + + + align:start position:0% +own absences and the absences of the +teachers they miss maybe about half of + + align:start position:0% +teachers they miss maybe about half of + + + align:start position:0% +teachers they miss maybe about half of +the school that they should have and + + align:start position:0% +the school that they should have and + + + align:start position:0% +the school that they should have and +they go one day they come back the next + + align:start position:0% +they go one day they come back the next + + + align:start position:0% +they go one day they come back the next +day they go one day they come back to + + align:start position:0% +day they go one day they come back to + + + align:start position:0% +day they go one day they come back to +the absent their presence pattern is + + align:start position:0% +the absent their presence pattern is + + + align:start position:0% +the absent their presence pattern is +extremely regular + + align:start position:0% +extremely regular + + + align:start position:0% +extremely regular +and then this is not equal across the + + align:start position:0% +and then this is not equal across the + + + align:start position:0% +and then this is not equal across the +country so in the North in Utah West + + align:start position:0% +country so in the North in Utah West + + + align:start position:0% +country so in the North in Utah West +Bengal absence rates are even lower with + + align:start position:0% +Bengal absence rates are even lower with + + + align:start position:0% +Bengal absence rates are even lower with +about 50 presence and it's better in the + + align:start position:0% +about 50 presence and it's better in the + + + align:start position:0% +about 50 presence and it's better in the +South like many of the social patterns + + align:start position:0% +South like many of the social patterns + + + align:start position:0% +South like many of the social patterns +uh if you're looking at the the world as + + align:start position:0% +uh if you're looking at the the world as + + + align:start position:0% +uh if you're looking at the the world as +a whole we don't have perfect data for + + align:start position:0% +a whole we don't have perfect data for + + + align:start position:0% +a whole we don't have perfect data for +the world as a whole but + + align:start position:0% +the world as a whole but + + + align:start position:0% +the world as a whole but +this is a + + align:start position:0% +this is a + + + align:start position:0% +this is a +enrollment with a darker the better so + + align:start position:0% +enrollment with a darker the better so + + + align:start position:0% +enrollment with a darker the better so +basically most countries now this is + + align:start position:0% +basically most countries now this is + + + align:start position:0% +basically most countries now this is +again pre-pandemic most countries were + + align:start position:0% +again pre-pandemic most countries were + + + align:start position:0% +again pre-pandemic most countries were +at that where data was measured were + + align:start position:0% +at that where data was measured were + + + align:start position:0% +at that where data was measured were +above 90 percent you know with some + + align:start position:0% +above 90 percent you know with some + + + align:start position:0% +above 90 percent you know with some +exception and basically the only + + align:start position:0% +exception and basically the only + + + align:start position:0% +exception and basically the only +exception being the sale countries + + align:start position:0% +exception being the sale countries + + + align:start position:0% +exception being the sale countries +which have lower lower + + align:start position:0% +which have lower lower + + + align:start position:0% +which have lower lower +annulments + + align:start position:0% +annulments + + + align:start position:0% +annulments +but other than this band where + + align:start position:0% +but other than this band where + + + align:start position:0% +but other than this band where +enrollment remaining issue the question + + align:start position:0% +enrollment remaining issue the question + + + align:start position:0% +enrollment remaining issue the question +of an element has somehow been had been + + align:start position:0% +of an element has somehow been had been + + + align:start position:0% +of an element has somehow been had been +solved + + align:start position:0% +solved + + + align:start position:0% +solved +by the way during the pandemic most of + + align:start position:0% +by the way during the pandemic most of + + + align:start position:0% +by the way during the pandemic most of +the kids stayed in the world because + + align:start position:0% +the kids stayed in the world because + + + align:start position:0% +the kids stayed in the world because +nobody bothered to take them off the + + align:start position:0% +nobody bothered to take them off the + + + align:start position:0% +nobody bothered to take them off the +role but that doesn't mean they're + + align:start position:0% +role but that doesn't mean they're + + + align:start position:0% +role but that doesn't mean they're +really there + + align:start position:0% +really there + + + align:start position:0% +really there +but the absence of course is even is + + align:start position:0% +but the absence of course is even is + + + align:start position:0% +but the absence of course is even is +is mostly much less good so here the + + align:start position:0% +is mostly much less good so here the + + + align:start position:0% +is mostly much less good so here the +there are much fewer countries in dark + + align:start position:0% +there are much fewer countries in dark + + + align:start position:0% +there are much fewer countries in dark +blue uh + + align:start position:0% +blue uh + + + align:start position:0% +blue uh +quite a few countries solid blue and but + + align:start position:0% +quite a few countries solid blue and but + + + align:start position:0% +quite a few countries solid blue and but +we see countries are appearing in in + + align:start position:0% +we see countries are appearing in in + + + align:start position:0% +we see countries are appearing in in +light blue so this is India between 70 + + align:start position:0% +light blue so this is India between 70 + + + align:start position:0% +light blue so this is India between 70 +and 80 percent happy to see that the two + + align:start position:0% +and 80 percent happy to see that the two + + + align:start position:0% +and 80 percent happy to see that the two +sources coincide + + align:start position:0% +sources coincide + + + align:start position:0% +sources coincide +and then uh we still have our sale + + align:start position:0% +and then uh we still have our sale + + + align:start position:0% +and then uh we still have our sale +country where not only they are not + + align:start position:0% +country where not only they are not + + + align:start position:0% +country where not only they are not +enrolled but in addition they don't go + + align:start position:0% +enrolled but in addition they don't go + + + align:start position:0% +enrolled but in addition they don't go +uh and and other countries where it's in + + align:start position:0% +uh and and other countries where it's in + + + align:start position:0% +uh and and other countries where it's in +the you know Pakistan Etc where it goes + + align:start position:0% +the you know Pakistan Etc where it goes + + + align:start position:0% +the you know Pakistan Etc where it goes +into the red and yellow so people don't + + align:start position:0% +into the red and yellow so people don't + + + align:start position:0% +into the red and yellow so people don't +show up that much + + align:start position:0% +show up that much + + + align:start position:0% +show up that much +and then as we already saw that they + + align:start position:0% +and then as we already saw that they + + + align:start position:0% +and then as we already saw that they +don't learn that much again that's data + + align:start position:0% +don't learn that much again that's data + + + align:start position:0% +don't learn that much again that's data +from from India + + align:start position:0% +from from India + + + align:start position:0% +from from India +uh uh since until + + align:start position:0% +uh uh since until + + + align:start position:0% +uh uh since until +1916 it's continued similarly the + + align:start position:0% +1916 it's continued similarly the + + + align:start position:0% +1916 it's continued similarly the +fraction of standard two kids who can + + align:start position:0% +fraction of standard two kids who can + + + align:start position:0% +fraction of standard two kids who can +who can read standard five kids who can + + align:start position:0% +who can read standard five kids who can + + + align:start position:0% +who can read standard five kids who can +read the stand up to text so like a + + align:start position:0% +read the stand up to text so like a + + + align:start position:0% +read the stand up to text so like a +paragraph basically and it's you know + + align:start position:0% +paragraph basically and it's you know + + + align:start position:0% +paragraph basically and it's you know +less than half not really going anywhere + + align:start position:0% +less than half not really going anywhere + + + align:start position:0% +less than half not really going anywhere +until it collapsed in in 2021. + + align:start position:0% +until it collapsed in in 2021. + + + align:start position:0% +until it collapsed in in 2021. +if anything in math it's a bit worse so + + align:start position:0% +if anything in math it's a bit worse so + + + align:start position:0% +if anything in math it's a bit worse so +that's the type of problems that they + + align:start position:0% +that's the type of problems that they + + + align:start position:0% +that's the type of problems that they +solve uh all that they are required to + + align:start position:0% +solve uh all that they are required to + + + align:start position:0% +solve uh all that they are required to +solve and the way the test works is that + + align:start position:0% +solve and the way the test works is that + + + align:start position:0% +solve and the way the test works is that +they're first shown the two-digit + + align:start position:0% +they're first shown the two-digit + + + align:start position:0% +they're first shown the two-digit +subtraction if they can do it they'll + + align:start position:0% +subtraction if they can do it they'll + + + align:start position:0% +subtraction if they can do it they'll +ask for a division if they cannot do it + + align:start position:0% +ask for a division if they cannot do it + + + align:start position:0% +ask for a division if they cannot do it +they are asked to recognize the numbers + + align:start position:0% +they are asked to recognize the numbers + + + align:start position:0% +they are asked to recognize the numbers +two digit number and then one digit + + align:start position:0% +two digit number and then one digit + + + align:start position:0% +two digit number and then one digit +number so that's how you have this level + + align:start position:0% + + + + align:start position:0% + +um so who can do a subtraction uh so we + + align:start position:0% +um so who can do a subtraction uh so we + + + align:start position:0% +um so who can do a subtraction uh so we +already saw these type of numbers but in + + align:start position:0% +already saw these type of numbers but in + + + align:start position:0% +already saw these type of numbers but in +standard five only half of the kids + + align:start position:0% +standard five only half of the kids + + + align:start position:0% +standard five only half of the kids +could do a subtraction in 2014. + + align:start position:0% +could do a subtraction in 2014. + + + align:start position:0% +could do a subtraction in 2014. +and in standard 8 only 44 percent of the + + align:start position:0% +and in standard 8 only 44 percent of the + + + align:start position:0% +and in standard 8 only 44 percent of the +kid could do this division + + align:start position:0% +kid could do this division + + + align:start position:0% +kid could do this division +so this in a sense was the well-known + + align:start position:0% +so this in a sense was the well-known + + + align:start position:0% +so this in a sense was the well-known +problem + + align:start position:0% +problem + + + align:start position:0% +problem +maybe it was known to you maybe it was + + align:start position:0% +maybe it was known to you maybe it was + + + align:start position:0% +maybe it was known to you maybe it was +not not known to you but it was well + + align:start position:0% +not not known to you but it was well + + + align:start position:0% +not not known to you but it was well +known to uh + + align:start position:0% +known to uh + + + align:start position:0% +known to uh +say the general education establishment + + align:start position:0% +say the general education establishment + + + align:start position:0% +say the general education establishment +uh this is something that again is not + + align:start position:0% +uh this is something that again is not + + + align:start position:0% +uh this is something that again is not +specific to India for a while we've + + align:start position:0% +specific to India for a while we've + + + align:start position:0% +specific to India for a while we've +known it mostly for India because every + + align:start position:0% +known it mostly for India because every + + + align:start position:0% +known it mostly for India because every +year this asset survey where they went + + align:start position:0% +year this asset survey where they went + + + align:start position:0% +year this asset survey where they went +to every single district and surveyed a + + align:start position:0% +to every single district and surveyed a + + + align:start position:0% +to every single district and surveyed a +representative sample of kids regardless + + align:start position:0% +representative sample of kids regardless + + + align:start position:0% +representative sample of kids regardless +of their annulment status + + align:start position:0% +of their annulment status + + + align:start position:0% +of their annulment status +uh since then the World Bank has done + + align:start position:0% +uh since then the World Bank has done + + + align:start position:0% +uh since then the World Bank has done +and then after the pandemic for the sort + + align:start position:0% +and then after the pandemic for the sort + + + align:start position:0% +and then after the pandemic for the sort +of expanded in other places and then we + + align:start position:0% +of expanded in other places and then we + + + align:start position:0% +of expanded in other places and then we +also have those big standardized tests + + align:start position:0% +also have those big standardized tests + + + align:start position:0% +also have those big standardized tests +like the Pisa which are used mostly in + + align:start position:0% +like the Pisa which are used mostly in + + + align:start position:0% +like the Pisa which are used mostly in +the Richer countries uh and then + + align:start position:0% +the Richer countries uh and then + + + align:start position:0% +the Richer countries uh and then +different countries started running + + align:start position:0% +different countries started running + + + align:start position:0% +different countries started running +their pattern there are third types + + align:start position:0% +their pattern there are third types + + + align:start position:0% +their pattern there are third types +tests so + + align:start position:0% +tests so + + + align:start position:0% +tests so +there was a little bit of uh kind of + + align:start position:0% +there was a little bit of uh kind of + + + align:start position:0% +there was a little bit of uh kind of +impressionistic data flowy floating all + + align:start position:0% +impressionistic data flowy floating all + + + align:start position:0% +impressionistic data flowy floating all +over the place and underpany Goldberg + + align:start position:0% +over the place and underpany Goldberg + + + align:start position:0% +over the place and underpany Goldberg +when she was Chief Economist and with + + align:start position:0% +when she was Chief Economist and with + + + align:start position:0% +when she was Chief Economist and with +the huge effort of Noam ungrast that + + align:start position:0% +the huge effort of Noam ungrast that + + + align:start position:0% +the huge effort of Noam ungrast that +would be Josh's son uh they made an + + align:start position:0% +would be Josh's son uh they made an + + + align:start position:0% +would be Josh's son uh they made an +effort to uh harmonize + + align:start position:0% +effort to uh harmonize + + + align:start position:0% +effort to uh harmonize +the learning levels across + + align:start position:0% +the learning levels across + + + align:start position:0% +the learning levels across +across countries basically by linking + + align:start position:0% +across countries basically by linking + + + align:start position:0% +across countries basically by linking +them back to an uh to to an essay like + + align:start position:0% +them back to an uh to to an essay like + + + align:start position:0% +them back to an uh to to an essay like +skill so it's a skin in 600 but uh + + align:start position:0% +skill so it's a skin in 600 but uh + + + align:start position:0% +skill so it's a skin in 600 but uh +basically using countries like India for + + align:start position:0% +basically using countries like India for + + + align:start position:0% +basically using countries like India for +example that have both a pizza-like test + + align:start position:0% +example that have both a pizza-like test + + + align:start position:0% +example that have both a pizza-like test +and a simple instrument and then to + + align:start position:0% +and a simple instrument and then to + + + align:start position:0% +and a simple instrument and then to +create a sort of a crossover so every + + align:start position:0% +create a sort of a crossover so every + + + align:start position:0% +create a sort of a crossover so every +country that has the two tests can be + + align:start position:0% +country that has the two tests can be + + + align:start position:0% +country that has the two tests can be +used to create a crossover between the + + align:start position:0% +used to create a crossover between the + + + align:start position:0% +used to create a crossover between the +different tests and in this way you can + + align:start position:0% +different tests and in this way you can + + + align:start position:0% +different tests and in this way you can +move from you know to put on a common + + align:start position:0% +move from you know to put on a common + + + align:start position:0% +move from you know to put on a common +scale countries that don't have a tool + + align:start position:0% +scale countries that don't have a tool + + + align:start position:0% +scale countries that don't have a tool +or common test to it's kind of a chain + + align:start position:0% +or common test to it's kind of a chain + + + align:start position:0% +or common test to it's kind of a chain +of things + + align:start position:0% +of things + + + align:start position:0% +of things +so it's a little bit impressionistic but + + align:start position:0% +so it's a little bit impressionistic but + + + align:start position:0% +so it's a little bit impressionistic but +it's it's a nice database it's publicly + + align:start position:0% +it's it's a nice database it's publicly + + + align:start position:0% +it's it's a nice database it's publicly +available the published a small + + align:start position:0% +available the published a small + + + align:start position:0% +available the published a small +descriptive paper on it in nature + + align:start position:0% +descriptive paper on it in nature + + + align:start position:0% +descriptive paper on it in nature +presently and the data is available so + + align:start position:0% +presently and the data is available so + + + align:start position:0% +presently and the data is available so +that's something interesting to to play + + align:start position:0% +that's something interesting to to play + + + align:start position:0% +that's something interesting to to play +with + + align:start position:0% +with + + + align:start position:0% +with +and this is one of the descriptive + + align:start position:0% +and this is one of the descriptive + + + align:start position:0% +and this is one of the descriptive +things so it's kind of hard to interpret + + align:start position:0% +things so it's kind of hard to interpret + + + align:start position:0% +things so it's kind of hard to interpret +the scale of course it's 600 whatever + + align:start position:0% +the scale of course it's 600 whatever + + + align:start position:0% +the scale of course it's 600 whatever +that means but for example you have + + align:start position:0% +that means but for example you have + + + align:start position:0% +that means but for example you have +Singapore here the U.S here and the + + align:start position:0% +Singapore here the U.S here and the + + + align:start position:0% +Singapore here the U.S here and the +worst countries like way below so there + + align:start position:0% +worst countries like way below so there + + + align:start position:0% +worst countries like way below so there +is vast differences in the in in what + + align:start position:0% +is vast differences in the in in what + + + align:start position:0% +is vast differences in the in in what +people learn uh + + align:start position:0% +people learn uh + + + align:start position:0% +people learn uh +you know you know in what people do + + align:start position:0% +you know you know in what people do + + + align:start position:0% +you know you know in what people do +let's say from this learning test and + + align:start position:0% +let's say from this learning test and + + + align:start position:0% +let's say from this learning test and +generally it's pretty correlated with + + align:start position:0% +generally it's pretty correlated with + + + align:start position:0% +generally it's pretty correlated with +income levels + + align:start position:0% +income levels + + + align:start position:0% +income levels +where poor countries + + align:start position:0% +where poor countries + + + align:start position:0% +where poor countries +I think this kind of the cluster of + + align:start position:0% +I think this kind of the cluster of + + + align:start position:0% +I think this kind of the cluster of +African country here that does pretty + + align:start position:0% +African country here that does pretty + + + align:start position:0% +African country here that does pretty +badly uh India just to tell you that + + align:start position:0% +badly uh India just to tell you that + + + align:start position:0% +badly uh India just to tell you that +India that we that we've talked a lot + + align:start position:0% +India that we that we've talked a lot + + + align:start position:0% +India that we that we've talked a lot +about India and we are going to talk a + + align:start position:0% +about India and we are going to talk a + + + align:start position:0% +about India and we are going to talk a +fair amount about India you might think + + align:start position:0% +fair amount about India you might think + + + align:start position:0% +fair amount about India you might think +well in something specific about India + + align:start position:0% +well in something specific about India + + + align:start position:0% +well in something specific about India +it's not it's terrible but India is + + align:start position:0% +it's not it's terrible but India is + + + align:start position:0% +it's not it's terrible but India is +actually not that you know + + align:start position:0% +actually not that you know + + + align:start position:0% +actually not that you know +it's out of where it should be on the on + + align:start position:0% +it's out of where it should be on the on + + + align:start position:0% +it's out of where it should be on the on +the line so it's relatively specific uh + + align:start position:0% +the line so it's relatively specific uh + + + align:start position:0% +the line so it's relatively specific uh +relatively representative of what's + + align:start position:0% +relatively representative of what's + + + align:start position:0% +relatively representative of what's +going on in the world + + align:start position:0% +going on in the world + + + align:start position:0% +going on in the world +so that's the part that I would say is + + align:start position:0% +so that's the part that I would say is + + + align:start position:0% +so that's the part that I would say is +noon was noon and to start with it's a + + align:start position:0% +noon was noon and to start with it's a + + + align:start position:0% +noon was noon and to start with it's a +big problem that kids everyone's going + + align:start position:0% +big problem that kids everyone's going + + + align:start position:0% +big problem that kids everyone's going +to school they spend a lot of time in + + align:start position:0% +to school they spend a lot of time in + + + align:start position:0% +to school they spend a lot of time in +school and then alone + + align:start position:0% +school and then alone + + + align:start position:0% +school and then alone +very little seems to be a big waste of + + align:start position:0% +very little seems to be a big waste of + + + align:start position:0% +very little seems to be a big waste of +time for everyone involved + + align:start position:0% +time for everyone involved + + + align:start position:0% +time for everyone involved +and and a problem because + + align:start position:0% +and and a problem because + + + align:start position:0% +and and a problem because +it would be nice if people learned more + + align:start position:0% +it would be nice if people learned more + + + align:start position:0% +it would be nice if people learned more +but in some sense I've come to uh to + + align:start position:0% +but in some sense I've come to uh to + + + align:start position:0% +but in some sense I've come to uh to +realize that that might not be the worst + + align:start position:0% +realize that that might not be the worst + + + align:start position:0% +realize that that might not be the worst +problem that that schools are worse than + + align:start position:0% +problem that that schools are worse than + + + align:start position:0% +problem that that schools are worse than +that they are worse than + + align:start position:0% +that they are worse than + + + align:start position:0% +that they are worse than +not being a very effective production + + align:start position:0% +not being a very effective production + + + align:start position:0% +not being a very effective production +function + + align:start position:0% +function + + + align:start position:0% +function +and that in our focus on production + + align:start position:0% +and that in our focus on production + + + align:start position:0% +and that in our focus on production +function we are missing uh a couple of + + align:start position:0% +function we are missing uh a couple of + + + align:start position:0% +function we are missing uh a couple of +things + + align:start position:0% + + + + align:start position:0% + +the first one the the + + align:start position:0% +the first one the the + + + align:start position:0% +the first one the the +and the perhaps the most important thing + + align:start position:0% +and the perhaps the most important thing + + + align:start position:0% +and the perhaps the most important thing +which I want to uh which I want to + + align:start position:0% +which I want to uh which I want to + + + align:start position:0% +which I want to uh which I want to +convey is that schools are not only they + + align:start position:0% +convey is that schools are not only they + + + align:start position:0% +convey is that schools are not only they +are unable to teach anything but they + + align:start position:0% +are unable to teach anything but they + + + align:start position:0% +are unable to teach anything but they +are unable to leverage and to + + align:start position:0% +are unable to leverage and to + + + align:start position:0% +are unable to leverage and to +acknowledge the skills that already + + align:start position:0% +acknowledge the skills that already + + + align:start position:0% +acknowledge the skills that already +there + + align:start position:0% +there + + + align:start position:0% +there +uh so in fact they don't teach but they + + align:start position:0% +uh so in fact they don't teach but they + + + align:start position:0% +uh so in fact they don't teach but they +also have a role of certification and + + align:start position:0% +also have a role of certification and + + + align:start position:0% +also have a role of certification and +they also should you know leverage + + align:start position:0% +they also should you know leverage + + + align:start position:0% +they also should you know leverage +what's there and kind of transform it so + + align:start position:0% +what's there and kind of transform it so + + + align:start position:0% +what's there and kind of transform it so +that kids can learn more and they are + + align:start position:0% +that kids can learn more and they are + + + align:start position:0% +that kids can learn more and they are +completely unable to do that + + align:start position:0% +completely unable to do that + + + align:start position:0% +completely unable to do that +so not only they don't teach but they + + align:start position:0% +so not only they don't teach but they + + + align:start position:0% +so not only they don't teach but they +also don't certified knowledge that they + + align:start position:0% +also don't certified knowledge that they + + + align:start position:0% +also don't certified knowledge that they +that's already there so they are missing + + align:start position:0% +that's already there so they are missing + + + align:start position:0% +that's already there so they are missing +at their second task which is pretty + + align:start position:0% +at their second task which is pretty + + + align:start position:0% +at their second task which is pretty +important because that's what people + + align:start position:0% +important because that's what people + + + align:start position:0% +important because that's what people +you know are able usually to take to the + + align:start position:0% +you know are able usually to take to the + + + align:start position:0% +you know are able usually to take to the +labor market is a diploma + + align:start position:0% +labor market is a diploma + + + align:start position:0% +labor market is a diploma +if the school stood nothing at least + + align:start position:0% +if the school stood nothing at least + + + align:start position:0% +if the school stood nothing at least +they should be able to administers + + align:start position:0% +they should be able to administers + + + align:start position:0% +they should be able to administers +diploma that if you have the skills you + + align:start position:0% +diploma that if you have the skills you + + + align:start position:0% +diploma that if you have the skills you +should be able to to get the parchment + + align:start position:0% +should be able to to get the parchment + + + align:start position:0% +should be able to to get the parchment +paper that goes with it + + align:start position:0% +paper that goes with it + + + align:start position:0% +paper that goes with it +uh so why do I think that school are + + align:start position:0% +uh so why do I think that school are + + + align:start position:0% +uh so why do I think that school are +unable to + + align:start position:0% +unable to + + + align:start position:0% +unable to +to boost leverage and recognize the + + align:start position:0% +to boost leverage and recognize the + + + align:start position:0% +to boost leverage and recognize the +knowledge that's there + + align:start position:0% +knowledge that's there + + + align:start position:0% +knowledge that's there +so I'll give you two uh two examples + + align:start position:0% +so I'll give you two uh two examples + + + align:start position:0% +so I'll give you two uh two examples +where that's pretty egregious uh both + + align:start position:0% +where that's pretty egregious uh both + + + align:start position:0% +where that's pretty egregious uh both +I'm involved with uh one is a set of + + align:start position:0% +I'm involved with uh one is a set of + + + align:start position:0% +I'm involved with uh one is a set of +studies that I've done with a + + align:start position:0% +studies that I've done with a + + + align:start position:0% +studies that I've done with a +psychologist at Harvard uh Liz pelke who + + align:start position:0% +psychologist at Harvard uh Liz pelke who + + + align:start position:0% +psychologist at Harvard uh Liz pelke who +is a specialist of math + + align:start position:0% +is a specialist of math + + + align:start position:0% +is a specialist of math +Master Early Childhood Mass education + + align:start position:0% +Master Early Childhood Mass education + + + align:start position:0% +Master Early Childhood Mass education +and Justin who was then students here is + + align:start position:0% +and Justin who was then students here is + + + align:start position:0% +and Justin who was then students here is +now at Chicago + + align:start position:0% +now at Chicago + + + align:start position:0% +now at Chicago +and and a student of of Liz who is now + + align:start position:0% +and and a student of of Liz who is now + + + align:start position:0% +and and a student of of Liz who is now +at NYU in the psychology department + + align:start position:0% +at NYU in the psychology department + + + align:start position:0% +at NYU in the psychology department +uh so what we did is that so the + + align:start position:0% +uh so what we did is that so the + + + align:start position:0% +uh so what we did is that so the +objective of this work and the reason + + align:start position:0% +objective of this work and the reason + + + align:start position:0% +objective of this work and the reason +why I came to sort of came to see her + + align:start position:0% +why I came to sort of came to see her + + + align:start position:0% +why I came to sort of came to see her +and to ask her to work with me + + align:start position:0% +and to ask her to work with me + + + align:start position:0% +and to ask her to work with me +uh is going to come back in uh towards + + align:start position:0% +uh is going to come back in uh towards + + + align:start position:0% +uh is going to come back in uh towards +the end of this lecture where + + align:start position:0% + + + + align:start position:0% + +I had been working with primary school + + align:start position:0% +I had been working with primary school + + + align:start position:0% +I had been working with primary school +and trying to improve the quality of + + align:start position:0% +and trying to improve the quality of + + + align:start position:0% +and trying to improve the quality of +primary school for a long time + + align:start position:0% +primary school for a long time + + + align:start position:0% +primary school for a long time +and found it very difficult because even + + align:start position:0% +and found it very difficult because even + + + align:start position:0% +and found it very difficult because even +though we have intervention that we know + + align:start position:0% +though we have intervention that we know + + + align:start position:0% +though we have intervention that we know +work it's like pulling teeth to get them + + align:start position:0% +work it's like pulling teeth to get them + + + align:start position:0% +work it's like pulling teeth to get them +adopted so we'll go back one of the + + align:start position:0% +adopted so we'll go back one of the + + + align:start position:0% +adopted so we'll go back one of the +things I want to discuss today is why + + align:start position:0% +things I want to discuss today is why + + + align:start position:0% +things I want to discuss today is why +that's the case but for now take that + + align:start position:0% +that's the case but for now take that + + + align:start position:0% +that's the case but for now take that +for a fact + + align:start position:0% +for a fact + + + align:start position:0% +for a fact +we have ideas of what what works but + + align:start position:0% +we have ideas of what what works but + + + align:start position:0% +we have ideas of what what works but +nobody is interested in it okay so I + + align:start position:0% +nobody is interested in it okay so I + + + align:start position:0% +nobody is interested in it okay so I +felt but at the same time more and more + + align:start position:0% +felt but at the same time more and more + + + align:start position:0% +felt but at the same time more and more +kids go to preschools + + align:start position:0% +kids go to preschools + + + align:start position:0% +kids go to preschools +and there nobody cares what they do in + + align:start position:0% +and there nobody cares what they do in + + + align:start position:0% +and there nobody cares what they do in +preschool + + align:start position:0% +preschool + + + align:start position:0% +preschool +oh it could be singing or mopping the + + align:start position:0% +oh it could be singing or mopping the + + + align:start position:0% +oh it could be singing or mopping the +floor or whatever it doesn't really + + align:start position:0% +floor or whatever it doesn't really + + + align:start position:0% +floor or whatever it doesn't really +matter it's child care so no one has + + align:start position:0% +matter it's child care so no one has + + + align:start position:0% +matter it's child care so no one has +much of a view + + align:start position:0% +much of a view + + + align:start position:0% +much of a view +so I thought well that's like a margin + + align:start position:0% +so I thought well that's like a margin + + + align:start position:0% +so I thought well that's like a margin +of action + + align:start position:0% +of action + + + align:start position:0% +of action +we should try and act in preschool to + + align:start position:0% +we should try and act in preschool to + + + align:start position:0% +we should try and act in preschool to +make the poor kids ready for school + + align:start position:0% +make the poor kids ready for school + + + align:start position:0% +make the poor kids ready for school +rather than try to fix the problem once + + align:start position:0% +rather than try to fix the problem once + + + align:start position:0% +rather than try to fix the problem once +they are in school + + align:start position:0% +they are in school + + + align:start position:0% +they are in school +and since Liz was working on on Early + + align:start position:0% +and since Liz was working on on Early + + + align:start position:0% +and since Liz was working on on Early +Childhood acquisition of math I thought + + align:start position:0% +Childhood acquisition of math I thought + + + align:start position:0% +Childhood acquisition of math I thought +maybe she knows something about or can + + align:start position:0% +maybe she knows something about or can + + + align:start position:0% +maybe she knows something about or can +develop something about that that we can + + align:start position:0% +develop something about that that we can + + + align:start position:0% +develop something about that that we can +Implement in in preschools to make the + + align:start position:0% +Implement in in preschools to make the + + + align:start position:0% +Implement in in preschools to make the +kids in preschool ahead of the game and + + align:start position:0% +kids in preschool ahead of the game and + + + align:start position:0% +kids in preschool ahead of the game and +able to understand better what's going + + align:start position:0% +able to understand better what's going + + + align:start position:0% +able to understand better what's going +on in school + + align:start position:0% +on in school + + + align:start position:0% +on in school +so uh so she was super interested in + + align:start position:0% +so uh so she was super interested in + + + align:start position:0% +so uh so she was super interested in +doing that so we started with a small + + align:start position:0% +doing that so we started with a small + + + align:start position:0% +doing that so we started with a small +experiment about 1500 kids in uh + + align:start position:0% +experiment about 1500 kids in uh + + + align:start position:0% +experiment about 1500 kids in uh +in preschool preschool classes operated + + align:start position:0% +in preschool preschool classes operated + + + align:start position:0% +in preschool preschool classes operated +by pratam in Delhi so this is kind of a + + align:start position:0% +by pratam in Delhi so this is kind of a + + + align:start position:0% +by pratam in Delhi so this is kind of a +class which is on a porch like a few + + align:start position:0% +class which is on a porch like a few + + + align:start position:0% +class which is on a porch like a few +kids and a young woman that's your class + + align:start position:0% +kids and a young woman that's your class + + + align:start position:0% +kids and a young woman that's your class +and they are playing one of our games so + + align:start position:0% +and they are playing one of our games so + + + align:start position:0% +and they are playing one of our games so +we are three condition + + align:start position:0% +we are three condition + + + align:start position:0% +we are three condition +one is math games where they played a + + align:start position:0% +one is math games where they played a + + + align:start position:0% +one is math games where they played a +curricula for a few weeks a whole + + align:start position:0% +curricula for a few weeks a whole + + + align:start position:0% +curricula for a few weeks a whole +curriculum on + + align:start position:0% +curriculum on + + + align:start position:0% +curriculum on +um + + align:start position:0% +um + + + align:start position:0% +um +kind of building + + align:start position:0% +kind of building + + + align:start position:0% +kind of building +non-symbolic math skills I'll tell you + + align:start position:0% +non-symbolic math skills I'll tell you + + + align:start position:0% +non-symbolic math skills I'll tell you +what it is in a second how it works then + + align:start position:0% +what it is in a second how it works then + + + align:start position:0% +what it is in a second how it works then +we had a sort of active control + + align:start position:0% +we had a sort of active control + + + align:start position:0% +we had a sort of active control +condition which is playing very similar + + align:start position:0% +condition which is playing very similar + + + align:start position:0% +condition which is playing very similar +games but to teach social skills instead + + align:start position:0% +games but to teach social skills instead + + + align:start position:0% +games but to teach social skills instead +of + + align:start position:0% +of + + + align:start position:0% +of +math the idea was not so much to teach + + align:start position:0% +math the idea was not so much to teach + + + align:start position:0% +math the idea was not so much to teach +social skills although why not it + + align:start position:0% +social skills although why not it + + + align:start position:0% +social skills although why not it +doesn't hurt but mainly to have a + + align:start position:0% +doesn't hurt but mainly to have a + + + align:start position:0% +doesn't hurt but mainly to have a +because not much is happens in those + + align:start position:0% +because not much is happens in those + + + align:start position:0% +because not much is happens in those +schools at all in general so we didn't + + align:start position:0% +schools at all in general so we didn't + + + align:start position:0% +schools at all in general so we didn't +want to say that they're learning better + + align:start position:0% +want to say that they're learning better + + + align:start position:0% +want to say that they're learning better +because someone is finally talking to + + align:start position:0% +because someone is finally talking to + + + align:start position:0% +because someone is finally talking to +them but they could be talking to them + + align:start position:0% +them but they could be talking to them + + + align:start position:0% +them but they could be talking to them +about something totally different so + + align:start position:0% +about something totally different so + + + align:start position:0% +about something totally different so +that's our active control and then a + + align:start position:0% +that's our active control and then a + + + align:start position:0% +that's our active control and then a +normal curriculum + + align:start position:0% +normal curriculum + + + align:start position:0% +normal curriculum +uh so we did some pretest and the games + + align:start position:0% +uh so we did some pretest and the games + + + align:start position:0% +uh so we did some pretest and the games +uh for three months and then a first + + align:start position:0% +uh for three months and then a first + + + align:start position:0% +uh for three months and then a first +post test and then we continued tracking + + align:start position:0% +post test and then we continued tracking + + + align:start position:0% +post test and then we continued tracking +the kids after they've reached school so + + align:start position:0% +the kids after they've reached school so + + + align:start position:0% +the kids after they've reached school so +long time after we have anything to do + + align:start position:0% +long time after we have anything to do + + + align:start position:0% +long time after we have anything to do +with them and in a sense that's the key + + align:start position:0% +with them and in a sense that's the key + + + align:start position:0% +with them and in a sense that's the key +is um + + align:start position:0% +is um + + + align:start position:0% +is um +so that's sort of that's the the game so + + align:start position:0% +so that's sort of that's the the game so + + + align:start position:0% +so that's sort of that's the the game so +this is based on this idea that uh um + + align:start position:0% +this is based on this idea that uh um + + + align:start position:0% +this is based on this idea that uh um +this cognitive scientists developed that + + align:start position:0% +this cognitive scientists developed that + + + align:start position:0% +this cognitive scientists developed that +before uh humans or in fact animals + + align:start position:0% +before uh humans or in fact animals + + + align:start position:0% +before uh humans or in fact animals +develop any notion of symbolic + + align:start position:0% +develop any notion of symbolic + + + align:start position:0% +develop any notion of symbolic +mathematics so understand numbers for + + align:start position:0% +mathematics so understand numbers for + + + align:start position:0% +mathematics so understand numbers for +example + + align:start position:0% +example + + + align:start position:0% +example +we already have a sense of some basic + + align:start position:0% +we already have a sense of some basic + + + align:start position:0% +we already have a sense of some basic +sense of mathematics for example what is + + align:start position:0% +sense of mathematics for example what is + + + align:start position:0% +sense of mathematics for example what is +bigger and what is smaller + + align:start position:0% +bigger and what is smaller + + + align:start position:0% +bigger and what is smaller +and bearing extreme disability everyone + + align:start position:0% +and bearing extreme disability everyone + + + align:start position:0% +and bearing extreme disability everyone +has that + + align:start position:0% +has that + + + align:start position:0% +has that +and it can be trained you can become + + align:start position:0% +and it can be trained you can become + + + align:start position:0% +and it can be trained you can become +better at it + + align:start position:0% +better at it + + + align:start position:0% +better at it +and uh from a purely correlational point + + align:start position:0% +and uh from a purely correlational point + + + align:start position:0% +and uh from a purely correlational point +of view kids who were better at this + + align:start position:0% +of view kids who were better at this + + + align:start position:0% +of view kids who were better at this +type of test when they were five + + align:start position:0% +type of test when they were five + + + align:start position:0% +type of test when they were five +are doing better at Pisa mathematics at + + align:start position:0% +are doing better at Pisa mathematics at + + + align:start position:0% +are doing better at Pisa mathematics at +15. + + align:start position:0% +15. + + + align:start position:0% +15. +of course what we don't know is that it + + align:start position:0% +of course what we don't know is that it + + + align:start position:0% +of course what we don't know is that it +means they have an underlying ability + + align:start position:0% +means they have an underlying ability + + + align:start position:0% +means they have an underlying ability +that makes them good at all sorts of + + align:start position:0% +that makes them good at all sorts of + + + align:start position:0% +that makes them good at all sorts of +math or whether this is that + + align:start position:0% +math or whether this is that + + + align:start position:0% +math or whether this is that +non-symbolic skills that kind of they + + align:start position:0% +non-symbolic skills that kind of they + + + align:start position:0% +non-symbolic skills that kind of they +built on more effectively to learn math + + align:start position:0% +built on more effectively to learn math + + + align:start position:0% +built on more effectively to learn math +through that there toward their career + + align:start position:0% +through that there toward their career + + + align:start position:0% +through that there toward their career +uh but what she what what they certainly + + align:start position:0% +uh but what she what what they certainly + + + align:start position:0% +uh but what she what what they certainly +hoped is that that was the case and + + align:start position:0% +hoped is that that was the case and + + + align:start position:0% +hoped is that that was the case and +therefore our the idea of our curriculum + + align:start position:0% +therefore our the idea of our curriculum + + + align:start position:0% +therefore our the idea of our curriculum +was initially to train non-symbolic math + + align:start position:0% +was initially to train non-symbolic math + + + align:start position:0% +was initially to train non-symbolic math +skills only + + align:start position:0% +skills only + + + align:start position:0% +skills only +and to see whether there is a + + align:start position:0% +and to see whether there is a + + + align:start position:0% +and to see whether there is a +translation of this impossible whether + + align:start position:0% +translation of this impossible whether + + + align:start position:0% +translation of this impossible whether +that can be trained and second of all + + align:start position:0% +that can be trained and second of all + + + align:start position:0% +that can be trained and second of all +whether if we manage to train them + + align:start position:0% +whether if we manage to train them + + + align:start position:0% +whether if we manage to train them +whether there is a translation in + + align:start position:0% +whether there is a translation in + + + align:start position:0% +whether there is a translation in +symbolic muskets down the line + + align:start position:0% +symbolic muskets down the line + + + align:start position:0% +symbolic muskets down the line +so that's an example of a game you have + + align:start position:0% +so that's an example of a game you have + + + align:start position:0% +so that's an example of a game you have +a card you do one has more dots than the + + align:start position:0% +a card you do one has more dots than the + + + align:start position:0% +a card you do one has more dots than the +other I think you can guess without + + align:start position:0% +other I think you can guess without + + + align:start position:0% +other I think you can guess without +counting and so the kids move the one + + align:start position:0% +counting and so the kids move the one + + + align:start position:0% +counting and so the kids move the one +that has murdered towards the the red + + align:start position:0% +that has murdered towards the the red + + + align:start position:0% +that has murdered towards the the red +bar this turn that's the hardest one + + align:start position:0% +bar this turn that's the hardest one + + + align:start position:0% +bar this turn that's the hardest one +because there are more points so young + + align:start position:0% +because there are more points so young + + + align:start position:0% +because there are more points so young +kids cannot do the many points and then + + align:start position:0% +kids cannot do the many points and then + + + align:start position:0% +kids cannot do the many points and then +as you get older and you can practice + + align:start position:0% +as you get older and you can practice + + + align:start position:0% +as you get older and you can practice +with that and then you become better as + + align:start position:0% +with that and then you become better as + + + align:start position:0% +with that and then you become better as +you practice then when they turn the + + align:start position:0% +you practice then when they turn the + + + align:start position:0% +you practice then when they turn the +count it actually gives them some + + align:start position:0% +count it actually gives them some + + + align:start position:0% +count it actually gives them some +her presentation including symbols so + + align:start position:0% +her presentation including symbols so + + + align:start position:0% +her presentation including symbols so +that introduces a little bit of the + + align:start position:0% +that introduces a little bit of the + + + align:start position:0% +that introduces a little bit of the +translation + + align:start position:0% +translation + + + align:start position:0% +translation +one can one thing kids are also + + align:start position:0% +one can one thing kids are also + + + align:start position:0% +one can one thing kids are also +surprisingly good is visual form + + align:start position:0% +surprisingly good is visual form + + + align:start position:0% +surprisingly good is visual form +analysis so here it's like there's one + + align:start position:0% +analysis so here it's like there's one + + + align:start position:0% +analysis so here it's like there's one +car that's not the same as the other + + align:start position:0% +car that's not the same as the other + + + align:start position:0% +car that's not the same as the other +uh what's the card that's different + + align:start position:0% + + + + align:start position:0% + +the one that had the floating point so + + align:start position:0% +the one that had the floating point so + + + align:start position:0% +the one that had the floating point so +they choose these are Plastics and they + + align:start position:0% +they choose these are Plastics and they + + + align:start position:0% +they choose these are Plastics and they +choose oh that was the wrong one that's + + align:start position:0% +choose oh that was the wrong one that's + + + align:start position:0% +choose oh that was the wrong one that's +the right one + + align:start position:0% +the right one + + + align:start position:0% +the right one +uh and then we had very very similar + + align:start position:0% +uh and then we had very very similar + + + align:start position:0% +uh and then we had very very similar +things for uh various structures same + + align:start position:0% +things for uh various structures same + + + align:start position:0% +things for uh various structures same +rules to learn + + align:start position:0% +rules to learn + + + align:start position:0% +rules to learn +emotion and gaze so for example this is + + align:start position:0% +emotion and gaze so for example this is + + + align:start position:0% +emotion and gaze so for example this is +the odd one out all of these are + + align:start position:0% +the odd one out all of these are + + + align:start position:0% +the odd one out all of these are +reasonably happy this one is so that's + + align:start position:0% +reasonably happy this one is so that's + + + align:start position:0% +reasonably happy this one is so that's +the equivalent for social games so we + + align:start position:0% +the equivalent for social games so we + + + align:start position:0% +the equivalent for social games so we +kind of constructed games that were + + align:start position:0% +kind of constructed games that were + + + align:start position:0% +kind of constructed games that were +precisely the same but + + align:start position:0% +precisely the same but + + + align:start position:0% +precisely the same but +in that sense working with psychologist + + align:start position:0% +in that sense working with psychologist + + + align:start position:0% +in that sense working with psychologist +is interesting because they really get + + align:start position:0% +is interesting because they really get + + + align:start position:0% +is interesting because they really get +into the details of things more than we + + align:start position:0% +into the details of things more than we + + + align:start position:0% +into the details of things more than we +do + + align:start position:0% +do + + + align:start position:0% +do +okay what do we find so the first + + align:start position:0% +okay what do we find so the first + + + align:start position:0% +okay what do we find so the first +finding and I want you to keep that and + + align:start position:0% +finding and I want you to keep that and + + + align:start position:0% +finding and I want you to keep that and +hold that suit because that's going to + + align:start position:0% +hold that suit because that's going to + + + align:start position:0% +hold that suit because that's going to +come + + align:start position:0% +come + + + align:start position:0% +come +handy in a little while + + align:start position:0% +handy in a little while + + + align:start position:0% +handy in a little while +is that the kids so this test these + + align:start position:0% +is that the kids so this test these + + + align:start position:0% +is that the kids so this test these +games were developed in Harvard in + + align:start position:0% +games were developed in Harvard in + + + align:start position:0% +games were developed in Harvard in +Lisa's Lab at Harvard + + align:start position:0% +Lisa's Lab at Harvard + + + align:start position:0% +Lisa's Lab at Harvard +and tested in Cambridge with whoever + + align:start position:0% +and tested in Cambridge with whoever + + + align:start position:0% +and tested in Cambridge with whoever +rather his volunteer if you have kids + + align:start position:0% +rather his volunteer if you have kids + + + align:start position:0% +rather his volunteer if you have kids +you can go from infant to uh to 10 I've + + align:start position:0% +you can go from infant to uh to 10 I've + + + align:start position:0% +you can go from infant to uh to 10 I've +taken my own kids it's quite fun they + + align:start position:0% +taken my own kids it's quite fun they + + + align:start position:0% +taken my own kids it's quite fun they +make them play all sorts of experiment + + align:start position:0% +make them play all sorts of experiment + + + align:start position:0% +make them play all sorts of experiment +and then in particular they came and + + align:start position:0% +and then in particular they came and + + + align:start position:0% +and then in particular they came and +played our + + align:start position:0% +played our + + + align:start position:0% +played our +they came and played out our games so we + + align:start position:0% +they came and played out our games so we + + + align:start position:0% +they came and played out our games so we +have observations from the kids mostly + + align:start position:0% +have observations from the kids mostly + + + align:start position:0% +have observations from the kids mostly +of postdoctoral students and assistant + + align:start position:0% +of postdoctoral students and assistant + + + align:start position:0% +of postdoctoral students and assistant +professors and that kind of things in + + align:start position:0% +professors and that kind of things in + + + align:start position:0% +professors and that kind of things in +Cambridge and and then we did the exact + + align:start position:0% +Cambridge and and then we did the exact + + + align:start position:0% +Cambridge and and then we did the exact +same you know we have the exact same + + align:start position:0% +same you know we have the exact same + + + align:start position:0% +same you know we have the exact same +measurement for these Indian kids who + + align:start position:0% +measurement for these Indian kids who + + + align:start position:0% +measurement for these Indian kids who +are living in slums in Delhi + + align:start position:0% +are living in slums in Delhi + + + align:start position:0% +are living in slums in Delhi +and they are just as good at playing + + align:start position:0% +and they are just as good at playing + + + align:start position:0% +and they are just as good at playing +these games they learn the rules they + + align:start position:0% +these games they learn the rules they + + + align:start position:0% +these games they learn the rules they +are able to learn quickly they progress + + align:start position:0% +are able to learn quickly they progress + + + align:start position:0% +are able to learn quickly they progress +fast + + align:start position:0% +fast + + + align:start position:0% +fast +they have just as much of these poor + + align:start position:0% +they have just as much of these poor + + + align:start position:0% +they have just as much of these poor +Indian kids have just as much an + + align:start position:0% +Indian kids have just as much an + + + align:start position:0% +Indian kids have just as much an +intuitive grasp and interesting number + + align:start position:0% +intuitive grasp and interesting number + + + align:start position:0% +intuitive grasp and interesting number +and geometry as the kids of uh of uh you + + align:start position:0% +and geometry as the kids of uh of uh you + + + align:start position:0% +and geometry as the kids of uh of uh you +know the faculty brats in in the in + + align:start position:0% +know the faculty brats in in the in + + + align:start position:0% +know the faculty brats in in the in +in Cambridge + + align:start position:0% +in Cambridge + + + align:start position:0% +in Cambridge +so that's + + align:start position:0% +so that's + + + align:start position:0% +so that's +kind of descriptive nothing to do with + + align:start position:0% +kind of descriptive nothing to do with + + + align:start position:0% +kind of descriptive nothing to do with +the intervention but it's interesting + + align:start position:0% +the intervention but it's interesting + + + align:start position:0% +the intervention but it's interesting +the second thing is that you can + + align:start position:0% +the second thing is that you can + + + align:start position:0% +the second thing is that you can +definitely train those these + + align:start position:0% +definitely train those these + + + align:start position:0% +definitely train those these +non-symbolic Mass test uh this bar is + + align:start position:0% +non-symbolic Mass test uh this bar is + + + align:start position:0% +non-symbolic Mass test uh this bar is +simply the difference between a + + align:start position:0% +simply the difference between a + + + align:start position:0% +simply the difference between a +treatment and the control control and + + align:start position:0% +treatment and the control control and + + + align:start position:0% +treatment and the control control and +then for the for the symbolic for the + + align:start position:0% +then for the for the symbolic for the + + + align:start position:0% +then for the for the symbolic for the +math games and that for the social games + + align:start position:0% +math games and that for the social games + + + align:start position:0% +math games and that for the social games +you can see that even with the social + + align:start position:0% +you can see that even with the social + + + align:start position:0% +you can see that even with the social +games they make progress so that's the + + align:start position:0% +games they make progress so that's the + + + align:start position:0% +games they make progress so that's the +fact that someone is you know teaching + + align:start position:0% +fact that someone is you know teaching + + + align:start position:0% +fact that someone is you know teaching +them to play games and all that that's + + align:start position:0% +them to play games and all that that's + + + align:start position:0% +them to play games and all that that's +probably not related to their ability to + + align:start position:0% +probably not related to their ability to + + + align:start position:0% +probably not related to their ability to +do the the tests uh so these tests are + + align:start position:0% +do the the tests uh so these tests are + + + align:start position:0% +do the the tests uh so these tests are +now presented in a completely + + align:start position:0% +now presented in a completely + + + align:start position:0% +now presented in a completely +non-gamified way but it's still the same + + align:start position:0% +non-gamified way but it's still the same + + + align:start position:0% +non-gamified way but it's still the same +type of things and they are much better + + align:start position:0% +type of things and they are much better + + + align:start position:0% +type of things and they are much better +at it + + align:start position:0% +at it + + + align:start position:0% +at it +much better even than the social games + + align:start position:0% +much better even than the social games + + + align:start position:0% +much better even than the social games +so that's one + + align:start position:0% +so that's one + + + align:start position:0% +so that's one +the second finding is that that's this + + align:start position:0% +the second finding is that that's this + + + align:start position:0% +the second finding is that that's this +this impact in particular the difference + + align:start position:0% +this impact in particular the difference + + + align:start position:0% +this impact in particular the difference +between math and social which is a true + + align:start position:0% +between math and social which is a true + + + align:start position:0% +between math and social which is a true +effect of learning the math it is it's + + align:start position:0% +effect of learning the math it is it's + + + align:start position:0% +effect of learning the math it is it's +remarkably stable + + align:start position:0% +remarkably stable + + + align:start position:0% +remarkably stable +uh you know what 18 months later they + + align:start position:0% +uh you know what 18 months later they + + + align:start position:0% +uh you know what 18 months later they +are still just as much better at it so + + align:start position:0% +are still just as much better at it so + + + align:start position:0% +are still just as much better at it so +it's not just that you know temporarily + + align:start position:0% +it's not just that you know temporarily + + + align:start position:0% +it's not just that you know temporarily +they got a weekend and that's striking + + align:start position:0% +they got a weekend and that's striking + + + align:start position:0% +they got a weekend and that's striking +because most educational intervention + + align:start position:0% +because most educational intervention + + + align:start position:0% +because most educational intervention +have impacted the advantage over time so + + align:start position:0% +have impacted the advantage over time so + + + align:start position:0% +have impacted the advantage over time so +usually you find an effect and then it + + align:start position:0% +usually you find an effect and then it + + + align:start position:0% +usually you find an effect and then it +goes away as you know life occurs + + align:start position:0% +goes away as you know life occurs + + + align:start position:0% +goes away as you know life occurs +interestingly We are following these + + align:start position:0% +interestingly We are following these + + + align:start position:0% +interestingly We are following these +kids now so this is like now they are in + + align:start position:0% +kids now so this is like now they are in + + + align:start position:0% +kids now so this is like now they are in +middle school so we are kind of + + align:start position:0% +middle school so we are kind of + + + align:start position:0% +middle school so we are kind of +interested to see whether it's still + + align:start position:0% +interested to see whether it's still + + + align:start position:0% +interested to see whether it's still +there but you know 18 months later it's + + align:start position:0% +there but you know 18 months later it's + + + align:start position:0% +there but you know 18 months later it's +still there + + align:start position:0% +still there + + + align:start position:0% +still there +third finding + + align:start position:0% +third finding + + + align:start position:0% +third finding +ah at end line one they are still with + + align:start position:0% +ah at end line one they are still with + + + align:start position:0% +ah at end line one they are still with +us they are still in the in the pattern + + align:start position:0% +us they are still in the in the pattern + + + align:start position:0% +us they are still in the in the pattern +preschool and pardon preschool does + + align:start position:0% +preschool and pardon preschool does + + + align:start position:0% +preschool and pardon preschool does +start introducing numbers and that type + + align:start position:0% +start introducing numbers and that type + + + align:start position:0% +start introducing numbers and that type +of things + + align:start position:0% +of things + + + align:start position:0% +of things +and at this point the effect is smaller + + align:start position:0% +and at this point the effect is smaller + + + align:start position:0% +and at this point the effect is smaller +so we can also test them on whether they + + align:start position:0% +so we can also test them on whether they + + + align:start position:0% +so we can also test them on whether they +can recognize numbers and shape and you + + align:start position:0% +can recognize numbers and shape and you + + + align:start position:0% +can recognize numbers and shape and you +know do you know that this is a this is + + align:start position:0% +know do you know that this is a this is + + + align:start position:0% +know do you know that this is a this is +a circle this is a rhombus Etc or the + + align:start position:0% +a circle this is a rhombus Etc or the + + + align:start position:0% +a circle this is a rhombus Etc or the +other numbers and they are somewhat + + align:start position:0% +other numbers and they are somewhat + + + align:start position:0% +other numbers and they are somewhat +better at it + + align:start position:0% +better at it + + + align:start position:0% +better at it +at inline one + + align:start position:0% +at inline one + + + align:start position:0% +at inline one +but then that difference entirely goes + + align:start position:0% +but then that difference entirely goes + + + align:start position:0% +but then that difference entirely goes +away as soon as I reach School + + align:start position:0% + + + + align:start position:0% + +so initiate so they start with them you + + align:start position:0% +so initiate so they start with them you + + + align:start position:0% +so initiate so they start with them you +know they arrive at school with a much + + align:start position:0% +know they arrive at school with a much + + + align:start position:0% +know they arrive at school with a much +greater sense of abstract mathematics + + align:start position:0% +greater sense of abstract mathematics + + + align:start position:0% +greater sense of abstract mathematics +as long as they were in the part-time + + align:start position:0% +as long as they were in the part-time + + + align:start position:0% +as long as they were in the part-time +environment there were some translation + + align:start position:0% +environment there were some translation + + + align:start position:0% +environment there were some translation +of that sense of abstract mathematics to + + align:start position:0% +of that sense of abstract mathematics to + + + align:start position:0% +of that sense of abstract mathematics to +not non-abstract mathematics but as soon + + align:start position:0% +not non-abstract mathematics but as soon + + + align:start position:0% +not non-abstract mathematics but as soon +as they leave school the rich school + + align:start position:0% +as they leave school the rich school + + + align:start position:0% +as they leave school the rich school +this is gone + + align:start position:0% +this is gone + + + align:start position:0% +this is gone +and uh so that's that's the result I + + align:start position:0% +and uh so that's that's the result I + + + align:start position:0% +and uh so that's that's the result I +want to this means this is a failure as + + align:start position:0% +want to this means this is a failure as + + + align:start position:0% +want to this means this is a failure as +an intervention for my from my objective + + align:start position:0% +an intervention for my from my objective + + + align:start position:0% +an intervention for my from my objective +but it's still an important result + + align:start position:0% +but it's still an important result + + + align:start position:0% +but it's still an important result +because what is telling us is that + + align:start position:0% +because what is telling us is that + + + align:start position:0% +because what is telling us is that +these kids have acquired these kids have + + align:start position:0% +these kids have acquired these kids have + + + align:start position:0% +these kids have acquired these kids have +acquired some skills that in the proper + + align:start position:0% +acquired some skills that in the proper + + + align:start position:0% +acquired some skills that in the proper +environment could be translated into + + align:start position:0% +environment could be translated into + + + align:start position:0% +environment could be translated into +learning to do numbers but the schools + + align:start position:0% +learning to do numbers but the schools + + + align:start position:0% +learning to do numbers but the schools +are totally unable to use it + + align:start position:0% +are totally unable to use it + + + align:start position:0% +are totally unable to use it +and you know it's not entirely + + align:start position:0% +and you know it's not entirely + + + align:start position:0% +and you know it's not entirely +surprising because they go to school and + + align:start position:0% +surprising because they go to school and + + + align:start position:0% +surprising because they go to school and +they start learning multiplication table + + align:start position:0% +they start learning multiplication table + + + align:start position:0% +they start learning multiplication table +and singing songs and so at very early + + align:start position:0% +and singing songs and so at very early + + + align:start position:0% +and singing songs and so at very early +grade mathematics in Indian primary + + align:start position:0% +grade mathematics in Indian primary + + + align:start position:0% +grade mathematics in Indian primary +school is more akin to poetry than to + + align:start position:0% +school is more akin to poetry than to + + + align:start position:0% +school is more akin to poetry than to +math + + align:start position:0% +math + + + align:start position:0% +math +um but uh this is so I'm not surprised + + align:start position:0% +um but uh this is so I'm not surprised + + + align:start position:0% +um but uh this is so I'm not surprised +by this result although I'm a bit sad + + align:start position:0% +by this result although I'm a bit sad + + + align:start position:0% +by this result although I'm a bit sad +but I um but I think this kind of shows + + align:start position:0% +but I um but I think this kind of shows + + + align:start position:0% +but I um but I think this kind of shows +like we handed you kids who were able to + + align:start position:0% +like we handed you kids who were able to + + + align:start position:0% +like we handed you kids who were able to +do math and you just uh erase that for + + align:start position:0% +do math and you just uh erase that for + + + align:start position:0% +do math and you just uh erase that for +them without by the way raising their + + align:start position:0% +them without by the way raising their + + + align:start position:0% +them without by the way raising their +their + + align:start position:0% + + + + align:start position:0% + +non-symbolic sense of math + + align:start position:0% +non-symbolic sense of math + + + align:start position:0% +non-symbolic sense of math +yeah actually interpret the magnets + + align:start position:0% +yeah actually interpret the magnets + + + align:start position:0% +yeah actually interpret the magnets +which is that like standard deviation + + align:start position:0% +which is that like standard deviation + + + align:start position:0% +which is that like standard deviation +the standard deviation like in most + + align:start position:0% +the standard deviation like in most + + + align:start position:0% +the standard deviation like in most +things so uh so they were uh so there + + align:start position:0% +things so uh so they were uh so there + + + align:start position:0% +things so uh so they were uh so there +were 0.13 celebration + + align:start position:0% +were 0.13 celebration + + + align:start position:0% +were 0.13 celebration +higher in the in the + + align:start position:0% +higher in the in the + + + align:start position:0% +higher in the in the +symbolic Mass which they had not learned + + align:start position:0% +symbolic Mass which they had not learned + + + align:start position:0% +symbolic Mass which they had not learned +in the in the games in the first end + + align:start position:0% +in the in the games in the first end + + + align:start position:0% +in the in the games in the first end +line and then + + align:start position:0% +line and then + + + align:start position:0% +line and then +0.025 which means zero basically uh down + + align:start position:0% +0.025 which means zero basically uh down + + + align:start position:0% +0.025 which means zero basically uh down +the line + + align:start position:0% + + + + align:start position:0% + +so that means that school are not able + + align:start position:0% +so that means that school are not able + + + align:start position:0% +so that means that school are not able +to Leverage The increased mathematical + + align:start position:0% +to Leverage The increased mathematical + + + align:start position:0% +to Leverage The increased mathematical +ability for so for us what does this + + align:start position:0% +ability for so for us what does this + + + align:start position:0% +ability for so for us what does this +mean is we have to go back to the + + align:start position:0% +mean is we have to go back to the + + + align:start position:0% +mean is we have to go back to the +drawing board to do that ourselves + + align:start position:0% +drawing board to do that ourselves + + + align:start position:0% +drawing board to do that ourselves +I'll go back to that in a bit but for + + align:start position:0% +I'll go back to that in a bit but for + + + align:start position:0% +I'll go back to that in a bit but for +kind of understanding schools that's the + + align:start position:0% +kind of understanding schools that's the + + + align:start position:0% +kind of understanding schools that's the +first point I want to make is that + + align:start position:0% +first point I want to make is that + + + align:start position:0% +first point I want to make is that +they were on the grade one were unable + + align:start position:0% +they were on the grade one were unable + + + align:start position:0% +they were on the grade one were unable +to do that no + + align:start position:0% +to do that no + + + align:start position:0% +to do that no +just maybe this is a bit special they + + align:start position:0% +just maybe this is a bit special they + + + align:start position:0% +just maybe this is a bit special they +don't they're not set up to uh their + + align:start position:0% +don't they're not set up to uh their + + + align:start position:0% +don't they're not set up to uh their +curriculum is is rigid the curriculum is + + align:start position:0% +curriculum is is rigid the curriculum is + + + align:start position:0% +curriculum is is rigid the curriculum is +is based first on and just you know + + align:start position:0% +is based first on and just you know + + + align:start position:0% +is based first on and just you know +learning the multiplication table they + + align:start position:0% +learning the multiplication table they + + + align:start position:0% +learning the multiplication table they +can't switch + + align:start position:0% +can't switch + + + align:start position:0% +can't switch +so here's another example of the fact + + align:start position:0% +so here's another example of the fact + + + align:start position:0% +so here's another example of the fact +that there is a lot of skill out there + + align:start position:0% +that there is a lot of skill out there + + + align:start position:0% +that there is a lot of skill out there +that the the schools are not able to uh + + align:start position:0% +that the the schools are not able to uh + + + align:start position:0% +that the the schools are not able to uh +to pick up + + align:start position:0% +to pick up + + + align:start position:0% +to pick up +and that studies that we did with the + + align:start position:0% +and that studies that we did with the + + + align:start position:0% +and that studies that we did with the +same basically coup + + align:start position:0% +same basically coup + + + align:start position:0% +same basically coup +on which is purely an observational + + align:start position:0% +on which is purely an observational + + + align:start position:0% +on which is purely an observational +study descriptive study of kids who sell + + align:start position:0% +study descriptive study of kids who sell + + + align:start position:0% +study descriptive study of kids who sell +in markets so I'm sure you've seen them + + align:start position:0% +in markets so I'm sure you've seen them + + + align:start position:0% +in markets so I'm sure you've seen them +uh in the eight countries you grew up + + align:start position:0% +uh in the eight countries you grew up + + + align:start position:0% +uh in the eight countries you grew up +with these kids selling in markets uh + + align:start position:0% +with these kids selling in markets uh + + + align:start position:0% +with these kids selling in markets uh +and they do a ton of math in there in + + align:start position:0% +and they do a ton of math in there in + + + align:start position:0% +and they do a ton of math in there in +the head at least in Indian market they + + align:start position:0% +the head at least in Indian market they + + + align:start position:0% +the head at least in Indian market they +just are so fast + + align:start position:0% +just are so fast + + + align:start position:0% +just are so fast +and this is something that has always + + align:start position:0% +and this is something that has always + + + align:start position:0% +and this is something that has always +struck a budget and Me + + align:start position:0% +struck a budget and Me + + + align:start position:0% +struck a budget and Me +Odd about the Acer test + + align:start position:0% +Odd about the Acer test + + + align:start position:0% +Odd about the Acer test +which is how come the kids cannot do the + + align:start position:0% +which is how come the kids cannot do the + + + align:start position:0% +which is how come the kids cannot do the +other test when they are doing things + + align:start position:0% +other test when they are doing things + + + align:start position:0% +other test when they are doing things +that are so much harder uh you know on a + + align:start position:0% +that are so much harder uh you know on a + + + align:start position:0% +that are so much harder uh you know on a +routine basis in their shop like what's + + align:start position:0% +routine basis in their shop like what's + + + align:start position:0% +routine basis in their shop like what's +the that + + align:start position:0% +the that + + + align:start position:0% +the that +so + + align:start position:0% +so + + + align:start position:0% +so +that's kind of the puzzle and so you + + align:start position:0% +that's kind of the puzzle and so you + + + align:start position:0% +that's kind of the puzzle and so you +might think well one reason is that it's + + align:start position:0% +might think well one reason is that it's + + + align:start position:0% +might think well one reason is that it's +only the kids after all there are not so + + align:start position:0% +only the kids after all there are not so + + + align:start position:0% +only the kids after all there are not so +many Market children and it's only the + + align:start position:0% +many Market children and it's only the + + + align:start position:0% +many Market children and it's only the +kids who are super good at math who are + + align:start position:0% +kids who are super good at math who are + + + align:start position:0% +kids who are super good at math who are +selected to to be Market seller and the + + align:start position:0% +selected to to be Market seller and the + + + align:start position:0% +selected to to be Market seller and the +other one to do other kind of things + + align:start position:0% +other one to do other kind of things + + + align:start position:0% +other one to do other kind of things +or it could be that the SR test is not + + align:start position:0% +or it could be that the SR test is not + + + align:start position:0% +or it could be that the SR test is not +incentivized no one cares they don't do + + align:start position:0% +incentivized no one cares they don't do + + + align:start position:0% +incentivized no one cares they don't do +it you know whatever or + + align:start position:0% +it you know whatever or + + + align:start position:0% +it you know whatever or +it could be that they knew how to do + + align:start position:0% +it could be that they knew how to do + + + align:start position:0% +it could be that they knew how to do +that in their head but they can't write + + align:start position:0% +that in their head but they can't write + + + align:start position:0% +that in their head but they can't write +and so they are completely baffled by + + align:start position:0% +and so they are completely baffled by + + + align:start position:0% +and so they are completely baffled by +the physical form of the test + + align:start position:0% +the physical form of the test + + + align:start position:0% +the physical form of the test +so we kind of were interested in in + + align:start position:0% +so we kind of were interested in in + + + align:start position:0% +so we kind of were interested in in +testing all these things + + align:start position:0% +testing all these things + + + align:start position:0% +testing all these things +so what we did is that we run to study + + align:start position:0% +so what we did is that we run to study + + + align:start position:0% +so what we did is that we run to study +one in Kolkata or in Delhi + + align:start position:0% +one in Kolkata or in Delhi + + + align:start position:0% +one in Kolkata or in Delhi +where we sent mystery shoppers to to the + + align:start position:0% +where we sent mystery shoppers to to the + + + align:start position:0% +where we sent mystery shoppers to to the +shops uh to buy some fruits and + + align:start position:0% +shops uh to buy some fruits and + + + align:start position:0% +shops uh to buy some fruits and +vegetables from the kids + + align:start position:0% + + + + align:start position:0% + +the way they did it is that they put at + + align:start position:0% +the way they did it is that they put at + + + align:start position:0% +the way they did it is that they put at +least two things say eggplant and + + align:start position:0% +least two things say eggplant and + + + align:start position:0% +least two things say eggplant and +tomatoes + + align:start position:0% +tomatoes + + + align:start position:0% +tomatoes +they bought a funny quantity so not half + + align:start position:0% +they bought a funny quantity so not half + + + align:start position:0% +they bought a funny quantity so not half +kg So when you buy when you go to the + + align:start position:0% +kg So when you buy when you go to the + + + align:start position:0% +kg So when you buy when you go to the +market you can either say give me half + + align:start position:0% +market you can either say give me half + + + align:start position:0% +market you can either say give me half +kg of tomatoes or you can take the + + align:start position:0% +kg of tomatoes or you can take the + + + align:start position:0% +kg of tomatoes or you can take the +tomatoes in a basket and you you get + + align:start position:0% +tomatoes in a basket and you you get + + + align:start position:0% +tomatoes in a basket and you you get +them weight so then you get like 323 + + align:start position:0% +them weight so then you get like 323 + + + align:start position:0% +them weight so then you get like 323 +grams + + align:start position:0% +grams + + + align:start position:0% +grams +so it doesn't get grounded up + + align:start position:0% +so it doesn't get grounded up + + + align:start position:0% +so it doesn't get grounded up +necessarily so they they got they got + + align:start position:0% +necessarily so they they got they got + + + align:start position:0% +necessarily so they they got they got +tomato and eggplant + + align:start position:0% +tomato and eggplant + + + align:start position:0% +tomato and eggplant +and then they handed a bill to the + + align:start position:0% +and then they handed a bill to the + + + align:start position:0% +and then they handed a bill to the +person to the kid who gave them change + + align:start position:0% +person to the kid who gave them change + + + align:start position:0% +person to the kid who gave them change +so the oppression involves a complicated + + align:start position:0% +so the oppression involves a complicated + + + align:start position:0% +so the oppression involves a complicated +multiplication uh the addition and then + + align:start position:0% +multiplication uh the addition and then + + + align:start position:0% +multiplication uh the addition and then +the subtraction + + align:start position:0% +the subtraction + + + align:start position:0% +the subtraction +and then they kind of challenged the kid + + align:start position:0% +and then they kind of challenged the kid + + + align:start position:0% +and then they kind of challenged the kid +on saying are you sure this is the right + + align:start position:0% +on saying are you sure this is the right + + + align:start position:0% +on saying are you sure this is the right +amount you give me and the key that to + + align:start position:0% +amount you give me and the key that to + + + align:start position:0% +amount you give me and the key that to +explain you know yes you take this + + align:start position:0% +explain you know yes you take this + + + align:start position:0% +explain you know yes you take this +multiplied by this this is this so you + + align:start position:0% +multiplied by this this is this so you + + + align:start position:0% +multiplied by this this is this so you +you know I'm right + + align:start position:0% +you know I'm right + + + align:start position:0% +you know I'm right +uh so we did that in Calcutta in Delhi + + align:start position:0% +uh so we did that in Calcutta in Delhi + + + align:start position:0% +uh so we did that in Calcutta in Delhi +and then we took the kids apart the last + + align:start position:0% +and then we took the kids apart the last + + + align:start position:0% +and then we took the kids apart the last +pair who went to do their shopping asked + + align:start position:0% +pair who went to do their shopping asked + + + align:start position:0% +pair who went to do their shopping asked +the parents if we could borrow the kids + + align:start position:0% +the parents if we could borrow the kids + + + align:start position:0% +the parents if we could borrow the kids +to do some math with them + + align:start position:0% +to do some math with them + + + align:start position:0% +to do some math with them +and uh and they did usually they agreed + + align:start position:0% +and uh and they did usually they agreed + + + align:start position:0% +and uh and they did usually they agreed +I came and did some maths with some math + + align:start position:0% +I came and did some maths with some math + + + align:start position:0% +I came and did some maths with some math +and then there we gave them + + align:start position:0% +and then there we gave them + + + align:start position:0% +and then there we gave them +problems of increasing level of + + align:start position:0% +problems of increasing level of + + + align:start position:0% +problems of increasing level of +abstraction so it's like an increasing + + align:start position:0% +abstraction so it's like an increasing + + + align:start position:0% +abstraction so it's like an increasing +level of far away it is so see if the + + align:start position:0% +level of far away it is so see if the + + + align:start position:0% +level of far away it is so see if the +guy is selling Tomatoes we are like so + + align:start position:0% +guy is selling Tomatoes we are like so + + + align:start position:0% +guy is selling Tomatoes we are like so +suppose the price of tomatoes is now 23 + + align:start position:0% +suppose the price of tomatoes is now 23 + + + align:start position:0% +suppose the price of tomatoes is now 23 +rupees instead of 20 + + align:start position:0% +rupees instead of 20 + + + align:start position:0% +rupees instead of 20 +uh how much would I pay you for half a + + align:start position:0% +uh how much would I pay you for half a + + + align:start position:0% +uh how much would I pay you for half a +kg of tomatoes and then when you replace + + align:start position:0% +kg of tomatoes and then when you replace + + + align:start position:0% +kg of tomatoes and then when you replace +the tomatoes by eggplant and then the + + align:start position:0% +the tomatoes by eggplant and then the + + + align:start position:0% +the tomatoes by eggplant and then the +eggplant by pens we are sell by units + + align:start position:0% +eggplant by pens we are sell by units + + + align:start position:0% +eggplant by pens we are sell by units +and not by and not by kilo so that + + align:start position:0% +and not by and not by kilo so that + + + align:start position:0% +and not by and not by kilo so that +changed the operation so increasing + + align:start position:0% +changed the operation so increasing + + + align:start position:0% +changed the operation so increasing +level of diff different from what you do + + align:start position:0% +level of diff different from what you do + + + align:start position:0% +level of diff different from what you do +in a normal in a day-to-day basis and + + align:start position:0% +in a normal in a day-to-day basis and + + + align:start position:0% +in a normal in a day-to-day basis and +then abstraction what is a + + align:start position:0% +then abstraction what is a + + + align:start position:0% +then abstraction what is a +55 times 7 and basically the SR test + + align:start position:0% +55 times 7 and basically the SR test + + + align:start position:0% +55 times 7 and basically the SR test +uh and done so that's what and then in + + align:start position:0% +uh and done so that's what and then in + + + align:start position:0% +uh and done so that's what and then in +Delhi we did the opposite which is we + + align:start position:0% +Delhi we did the opposite which is we + + + align:start position:0% +Delhi we did the opposite which is we +went to schools in this very + + align:start position:0% +went to schools in this very + + + align:start position:0% +went to schools in this very +neighborhoods by the way a lot of the + + align:start position:0% +neighborhoods by the way a lot of the + + + align:start position:0% +neighborhoods by the way a lot of the +kids who are in markets are also in + + align:start position:0% +kids who are in markets are also in + + + align:start position:0% +kids who are in markets are also in +school but not all of them and then so + + align:start position:0% +school but not all of them and then so + + + align:start position:0% +school but not all of them and then so +we went to schools where most kids are + + align:start position:0% +we went to schools where most kids are + + + align:start position:0% +we went to schools where most kids are +not working in markets but they are very + + align:start position:0% +not working in markets but they are very + + + align:start position:0% +not working in markets but they are very +similar um + + align:start position:0% +similar um + + + align:start position:0% +similar um +neighborhoods social status Etc + + align:start position:0% +neighborhoods social status Etc + + + align:start position:0% +neighborhoods social status Etc +and we had them do the same tests plus + + align:start position:0% +and we had them do the same tests plus + + + align:start position:0% +and we had them do the same tests plus +uh sell items + + align:start position:0% +uh sell items + + + align:start position:0% +uh sell items +so they set up a little market and they + + align:start position:0% +so they set up a little market and they + + + align:start position:0% +so they set up a little market and they +are selling the selling selling the + + align:start position:0% +are selling the selling selling the + + + align:start position:0% +are selling the selling selling the +items + + align:start position:0% +items + + + align:start position:0% +items +so that's the project there was a + + align:start position:0% +so that's the project there was a + + + align:start position:0% +so that's the project there was a +descriptive + + align:start position:0% +descriptive + + + align:start position:0% +descriptive +um very fun study to do + + align:start position:0% +um very fun study to do + + + align:start position:0% +um very fun study to do +and here's what we found so uh the first + + align:start position:0% +and here's what we found so uh the first + + + align:start position:0% +and here's what we found so uh the first +thing we found is that our sort of + + align:start position:0% +thing we found is that our sort of + + + align:start position:0% +thing we found is that our sort of +impressionistic impression that + + align:start position:0% +impressionistic impression that + + + align:start position:0% +impressionistic impression that +impersonating impression makes it a bit + + align:start position:0% +impersonating impression makes it a bit + + + align:start position:0% +impersonating impression makes it a bit +over determined our filling observations + + align:start position:0% +over determined our filling observations + + + align:start position:0% +over determined our filling observations +that the kids are really good at doing + + align:start position:0% +that the kids are really good at doing + + + align:start position:0% +that the kids are really good at doing +this math seems to really hold true so + + align:start position:0% +this math seems to really hold true so + + + align:start position:0% +this math seems to really hold true so +in Kolkata they are above there are + + align:start position:0% +in Kolkata they are above there are + + + align:start position:0% +in Kolkata they are above there are +around 90 percent uh right the first + + align:start position:0% +around 90 percent uh right the first + + + align:start position:0% +around 90 percent uh right the first +time and then if they were wrong since + + align:start position:0% +time and then if they were wrong since + + + align:start position:0% +time and then if they were wrong since +they were challenged they had a chance + + align:start position:0% +they were challenged they had a chance + + + align:start position:0% +they were challenged they had a chance +to correct and then with correction + + align:start position:0% +to correct and then with correction + + + align:start position:0% +to correct and then with correction +there are like 95 98 percent + + align:start position:0% +there are like 95 98 percent + + + align:start position:0% +there are like 95 98 percent +uh on in their + + align:start position:0% +uh on in their + + + align:start position:0% +uh on in their +in the this uh + + align:start position:0% +in the this uh + + + align:start position:0% +in the this uh +um + + align:start position:0% +um + + + align:start position:0% +um +real transactions + + align:start position:0% +real transactions + + + align:start position:0% +real transactions +in Delhi the first one was a little + + align:start position:0% +in Delhi the first one was a little + + + align:start position:0% +in Delhi the first one was a little +lower uh I think that's because those + + align:start position:0% +lower uh I think that's because those + + + align:start position:0% +lower uh I think that's because those +were relatively unusual for Market + + align:start position:0% +were relatively unusual for Market + + + align:start position:0% +were relatively unusual for Market +transactions to ask you two goods in + + align:start position:0% +transactions to ask you two goods in + + + align:start position:0% +transactions to ask you two goods in +unusual quantity but then when the + + align:start position:0% +unusual quantity but then when the + + + align:start position:0% +unusual quantity but then when the +second times got around second person + + align:start position:0% +second times got around second person + + + align:start position:0% +second times got around second person +got around the data their brain were + + align:start position:0% +got around the data their brain were + + + align:start position:0% +got around the data their brain were +awake and they were they also with like + + align:start position:0% +awake and they were they also with like + + + align:start position:0% +awake and they were they also with like +94 95 accuracy + + align:start position:0% +94 95 accuracy + + + align:start position:0% +94 95 accuracy +and then you comprehend the school + + align:start position:0% +and then you comprehend the school + + + align:start position:0% +and then you comprehend the school +children doing the same exercise and + + align:start position:0% +children doing the same exercise and + + + align:start position:0% +children doing the same exercise and +they are much worse + + align:start position:0% +they are much worse + + + align:start position:0% +they are much worse +so uh so that's the first thing that + + align:start position:0% +so uh so that's the first thing that + + + align:start position:0% +so uh so that's the first thing that +they are very good at doing that are + + align:start position:0% +they are very good at doing that are + + + align:start position:0% +they are very good at doing that are +indeed very good at Market arithmetics + + align:start position:0% +indeed very good at Market arithmetics + + + align:start position:0% +indeed very good at Market arithmetics +much better than school children + + align:start position:0% +much better than school children + + + align:start position:0% +much better than school children +so you could think it's just selection + + align:start position:0% +so you could think it's just selection + + + align:start position:0% +so you could think it's just selection +so it's it's the kids the best kids at + + align:start position:0% +so it's it's the kids the best kids at + + + align:start position:0% +so it's it's the kids the best kids at +math are in working in the market + + align:start position:0% +math are in working in the market + + + align:start position:0% +math are in working in the market +uh + + align:start position:0% +uh + + + align:start position:0% +uh +so we can look at so oh you could say + + align:start position:0% +so we can look at so oh you could say + + + align:start position:0% +so we can look at so oh you could say +well there might be other reason for + + align:start position:0% +well there might be other reason for + + + align:start position:0% +well there might be other reason for +example they know everything by heart + + align:start position:0% +example they know everything by heart + + + align:start position:0% +example they know everything by heart +they just have a table in the back of + + align:start position:0% +they just have a table in the back of + + + align:start position:0% +they just have a table in the back of +their mind that that tells them how much + + align:start position:0% +their mind that that tells them how much + + + align:start position:0% +their mind that that tells them how much +things + + align:start position:0% +things + + + align:start position:0% +things +um things cost + + align:start position:0% +um things cost + + + align:start position:0% +um things cost +so here we can look at the people's + + align:start position:0% +so here we can look at the people's + + + align:start position:0% +so here we can look at the people's +ability to uh to do other to do other + + align:start position:0% +ability to uh to do other to do other + + + align:start position:0% +ability to uh to do other to do other +things + + align:start position:0% +things + + + align:start position:0% +things +uh so in Kolkata we just had one + + align:start position:0% +uh so in Kolkata we just had one + + + align:start position:0% +uh so in Kolkata we just had one +hypothetical transaction that was quite + + align:start position:0% +hypothetical transaction that was quite + + + align:start position:0% +hypothetical transaction that was quite +removed to what they were doing usually + + align:start position:0% +removed to what they were doing usually + + + align:start position:0% +removed to what they were doing usually +and we saw that they were not doing that + + align:start position:0% +and we saw that they were not doing that + + + align:start position:0% +and we saw that they were not doing that +great on it + + align:start position:0% +great on it + + + align:start position:0% +great on it +uh so now in delhi what we did is we + + align:start position:0% +uh so now in delhi what we did is we + + + align:start position:0% +uh so now in delhi what we did is we +progressed as I was saying by level of + + align:start position:0% +progressed as I was saying by level of + + + align:start position:0% +progressed as I was saying by level of +how far it is and so the further it is + + align:start position:0% +how far it is and so the further it is + + + align:start position:0% +how far it is and so the further it is +the more difficult it is + + align:start position:0% +the more difficult it is + + + align:start position:0% +the more difficult it is +so if it's the same type of goods it's + + align:start position:0% +so if it's the same type of goods it's + + + align:start position:0% +so if it's the same type of goods it's +better if it's at least in the same unit + + align:start position:0% +better if it's at least in the same unit + + + align:start position:0% +better if it's at least in the same unit +it's better or if it's and so there is + + align:start position:0% +it's better or if it's and so there is + + + align:start position:0% +it's better or if it's and so there is +some flexibility within my within Market + + align:start position:0% +some flexibility within my within Market + + + align:start position:0% +some flexibility within my within Market +transaction they can do other ones and + + align:start position:0% +transaction they can do other ones and + + + align:start position:0% +transaction they can do other ones and +then the more but there's a limit to + + align:start position:0% +then the more but there's a limit to + + + align:start position:0% +then the more but there's a limit to +this flexibility there there are so they + + align:start position:0% +this flexibility there there are so they + + + align:start position:0% +this flexibility there there are so they +are not it's not by road because you can + + align:start position:0% +are not it's not by road because you can + + + align:start position:0% +are not it's not by road because you can +change the number on them but there is + + align:start position:0% +change the number on them but there is + + + align:start position:0% +change the number on them but there is +some limit to this to this you know how + + align:start position:0% +some limit to this to this you know how + + + align:start position:0% +some limit to this to this you know how +well they can adapt to other things so + + align:start position:0% +well they can adapt to other things so + + + align:start position:0% +well they can adapt to other things so +they are not like that spectacular at + + align:start position:0% +they are not like that spectacular at + + + align:start position:0% +they are not like that spectacular at +math once you remove + + align:start position:0% +math once you remove + + + align:start position:0% +math once you remove +and where are they really have a problem + + align:start position:0% +and where are they really have a problem + + + align:start position:0% +and where are they really have a problem +and again this is what's the + + align:start position:0% + + + + align:start position:0% + +observation is that they are really + + align:start position:0% +observation is that they are really + + + align:start position:0% +observation is that they are really +terrible at the pattern at the pattern + + align:start position:0% +terrible at the pattern at the pattern + + + align:start position:0% +terrible at the pattern at the pattern +type tests are only 32 percent of them + + align:start position:0% +type tests are only 32 percent of them + + + align:start position:0% +type tests are only 32 percent of them +can do a division in Kolkata 15 percent + + align:start position:0% +can do a division in Kolkata 15 percent + + + align:start position:0% +can do a division in Kolkata 15 percent +in uh in in Delhi only about half can do + + align:start position:0% +in uh in in Delhi only about half can do + + + align:start position:0% +in uh in in Delhi only about half can do +a subtraction uh so similar to the + + align:start position:0% +a subtraction uh so similar to the + + + align:start position:0% +a subtraction uh so similar to the +Karnataka level for example + + align:start position:0% +Karnataka level for example + + + align:start position:0% +Karnataka level for example +uh + + align:start position:0% +uh + + + align:start position:0% +uh +and there the daily school children are + + align:start position:0% +and there the daily school children are + + + align:start position:0% +and there the daily school children are +much better than they are + + align:start position:0% +much better than they are + + + align:start position:0% +much better than they are +so it's so it was not like just + + align:start position:0% +so it's so it was not like just + + + align:start position:0% +so it's so it was not like just +selection the best mathematician end up + + align:start position:0% +selection the best mathematician end up + + + align:start position:0% +selection the best mathematician end up +in the class the best mathematician can + + align:start position:0% +in the class the best mathematician can + + + align:start position:0% +in the class the best mathematician can +do + + align:start position:0% +do + + + align:start position:0% +do +Market Mass + + align:start position:0% +Market Mass + + + align:start position:0% +Market Mass +uh not spectacularly because they can't + + align:start position:0% +uh not spectacularly because they can't + + + align:start position:0% +uh not spectacularly because they can't +go away spectacularly for their own job + + align:start position:0% +go away spectacularly for their own job + + + align:start position:0% +go away spectacularly for their own job +but they they don't have the kind of + + align:start position:0% +but they they don't have the kind of + + + align:start position:0% +but they they don't have the kind of +mental gymnastics to go to other things + + align:start position:0% +mental gymnastics to go to other things + + + align:start position:0% +mental gymnastics to go to other things +but they really can't go to the to uh to + + align:start position:0% +but they really can't go to the to uh to + + + align:start position:0% +but they really can't go to the to uh to +the Acer test and they do worse than the + + align:start position:0% +the Acer test and they do worse than the + + + align:start position:0% +the Acer test and they do worse than the +delicate + + align:start position:0% +delicate + + + align:start position:0% +delicate +so the delicates can do the SR test + + align:start position:0% +so the delicates can do the SR test + + + align:start position:0% +so the delicates can do the SR test +quite well in fact when you compare to + + align:start position:0% +quite well in fact when you compare to + + + align:start position:0% +quite well in fact when you compare to +the rest of India but they cannot do a + + align:start position:0% +the rest of India but they cannot do a + + + align:start position:0% +the rest of India but they cannot do a +hypothetical transaction the market kids + + align:start position:0% +hypothetical transaction the market kids + + + align:start position:0% +hypothetical transaction the market kids +can do the market transaction but it + + align:start position:0% +can do the market transaction but it + + + align:start position:0% +can do the market transaction but it +cannot cannot do the daily test + + align:start position:0% +cannot cannot do the daily test + + + align:start position:0% +cannot cannot do the daily test +and one of the things that really trips + + align:start position:0% +and one of the things that really trips + + + align:start position:0% +and one of the things that really trips +the market kids is uh the where you + + align:start position:0% +the market kids is uh the where you + + + align:start position:0% +the market kids is uh the where you +really have a huge drop off + + align:start position:0% +really have a huge drop off + + + align:start position:0% +really have a huge drop off +is when things are presented in abstract + + align:start position:0% +is when things are presented in abstract + + + align:start position:0% +is when things are presented in abstract +term as opposed to uncut them + + align:start position:0% +term as opposed to uncut them + + + align:start position:0% +term as opposed to uncut them +so the same kid can do uh can you give + + align:start position:0% +so the same kid can do uh can you give + + + align:start position:0% +so the same kid can do uh can you give +me uh the price of one pen if a five Pen + + align:start position:0% +me uh the price of one pen if a five Pen + + + align:start position:0% +me uh the price of one pen if a five Pen +cost 20 cents and cannot do uh 20 + + align:start position:0% +cost 20 cents and cannot do uh 20 + + + align:start position:0% +cost 20 cents and cannot do uh 20 +divided by 5. + + align:start position:0% +divided by 5. + + + align:start position:0% +divided by 5. +the basically this is what this says + + align:start position:0% +the basically this is what this says + + + align:start position:0% +the basically this is what this says +this is what this comparison here + + align:start position:0% +this is what this comparison here + + + align:start position:0% +this is what this comparison here +similarly for for those kids so going to + + align:start position:0% +similarly for for those kids so going to + + + align:start position:0% +similarly for for those kids so going to +abstraction is what makes it even if + + align:start position:0% +abstraction is what makes it even if + + + align:start position:0% +abstraction is what makes it even if +it's the exact same problem + + align:start position:0% +it's the exact same problem + + + align:start position:0% +it's the exact same problem +uh removing the the anchoring to a real + + align:start position:0% +uh removing the the anchoring to a real + + + align:start position:0% +uh removing the the anchoring to a real +items is very difficult for them + + align:start position:0% +items is very difficult for them + + + align:start position:0% +items is very difficult for them +with one exception + + align:start position:0% +with one exception + + + align:start position:0% +with one exception +when it is possible to round things up + + align:start position:0% +when it is possible to round things up + + + align:start position:0% +when it is possible to round things up +for example if the problem is 31 times 7 + + align:start position:0% +for example if the problem is 31 times 7 + + + align:start position:0% +for example if the problem is 31 times 7 +which you can do as 30 times 7 plus 7 + + align:start position:0% +which you can do as 30 times 7 plus 7 + + + align:start position:0% +which you can do as 30 times 7 plus 7 +they are they are good at that they are + + align:start position:0% +they are they are good at that they are + + + align:start position:0% +they are they are good at that they are +good at simplifying problems even when + + align:start position:0% +good at simplifying problems even when + + + align:start position:0% +good at simplifying problems even when +they are abstract + + align:start position:0% +they are abstract + + + align:start position:0% +they are abstract +so uh when they are um so this is a + + align:start position:0% +so uh when they are um so this is a + + + align:start position:0% +so uh when they are um so this is a +subtraction we didn't do it for division + + align:start position:0% +subtraction we didn't do it for division + + + align:start position:0% +subtraction we didn't do it for division +but for a non-readable abstract + + align:start position:0% +but for a non-readable abstract + + + align:start position:0% +but for a non-readable abstract +subtraction even after correction if + + align:start position:0% +subtraction even after correction if + + + align:start position:0% +subtraction even after correction if +they finally get it 65 percent of the + + align:start position:0% +they finally get it 65 percent of the + + + align:start position:0% +they finally get it 65 percent of the +time + + align:start position:0% +time + + + align:start position:0% +time +if it's surroundable they get it 85 + + align:start position:0% +if it's surroundable they get it 85 + + + align:start position:0% +if it's surroundable they get it 85 +percent of the time + + align:start position:0% +percent of the time + + + align:start position:0% +percent of the time +in an abstract form + + align:start position:0% +in an abstract form + + + align:start position:0% +in an abstract form +if it's uncut they do better to start + + align:start position:0% +if it's uncut they do better to start + + + align:start position:0% +if it's uncut they do better to start +with that's what we saw in the previous + + align:start position:0% +with that's what we saw in the previous + + + align:start position:0% +with that's what we saw in the previous +graph that the the abstraction tripped + + align:start position:0% +graph that the the abstraction tripped + + + align:start position:0% +graph that the the abstraction tripped +them up but and then rounded 100 and on + + align:start position:0% +them up but and then rounded 100 and on + + + align:start position:0% +them up but and then rounded 100 and on +the button on car they are you know as + + align:start position:0% +the button on car they are you know as + + + align:start position:0% +the button on car they are you know as +good as they are in the market they + + align:start position:0% +good as they are in the market they + + + align:start position:0% +good as they are in the market they +reach 290 so they are very good at + + align:start position:0% +reach 290 so they are very good at + + + align:start position:0% +reach 290 so they are very good at +rounding + + align:start position:0% +rounding + + + align:start position:0% +rounding +and the by cons by comparison the daily + + align:start position:0% +and the by cons by comparison the daily + + + align:start position:0% +and the by cons by comparison the daily +school children don't get uh much as + + align:start position:0% +school children don't get uh much as + + + align:start position:0% +school children don't get uh much as +much as a boost + + align:start position:0% +much as a boost + + + align:start position:0% +much as a boost +on rounding as the daily as as the daily + + align:start position:0% +on rounding as the daily as as the daily + + + align:start position:0% +on rounding as the daily as as the daily +Market children and the reason is that + + align:start position:0% +Market children and the reason is that + + + align:start position:0% +Market children and the reason is that +there is school children don't use + + align:start position:0% +there is school children don't use + + + align:start position:0% +there is school children don't use +this strategy at all so they have + + align:start position:0% +this strategy at all so they have + + + align:start position:0% +this strategy at all so they have +uh this is what the + + align:start position:0% +uh this is what the + + + align:start position:0% +uh this is what the +what they write up + + align:start position:0% +what they write up + + + align:start position:0% +what they write up +um + + align:start position:0% +um + + + align:start position:0% +um +you know how much how much do they write + + align:start position:0% +you know how much how much do they write + + + align:start position:0% +you know how much how much do they write +on a piece of paper to solve the problem + + align:start position:0% +on a piece of paper to solve the problem + + + align:start position:0% +on a piece of paper to solve the problem +and so this is a number of tally marks + + align:start position:0% +and so this is a number of tally marks + + + align:start position:0% +and so this is a number of tally marks +that they are making + + align:start position:0% +that they are making + + + align:start position:0% +that they are making +and so the + + align:start position:0% +and so the + + + align:start position:0% +and so the +the kids in Market basically do + + align:start position:0% +the kids in Market basically do + + + align:start position:0% +the kids in Market basically do +everything in their head + + align:start position:0% +everything in their head + + + align:start position:0% +everything in their head +the kid is in Delhi do everything uh + + align:start position:0% +the kid is in Delhi do everything uh + + + align:start position:0% +the kid is in Delhi do everything uh +written up the right Million numbers and + + align:start position:0% +written up the right Million numbers and + + + align:start position:0% +written up the right Million numbers and +I realize that I'm not showing I'm + + align:start position:0% +I realize that I'm not showing I'm + + + align:start position:0% +I realize that I'm not showing I'm +showing you how they write a Million + + align:start position:0% +showing you how they write a Million + + + align:start position:0% +showing you how they write a Million +numbers + + align:start position:0% +numbers + + + align:start position:0% +numbers +and I realized that I didn't take the + + align:start position:0% +and I realized that I didn't take the + + + align:start position:0% +and I realized that I didn't take the +right graph so let me they write just as + + align:start position:0% +right graph so let me they write just as + + + align:start position:0% +right graph so let me they write just as +many number of its surroundable life + + align:start position:0% +many number of its surroundable life + + + align:start position:0% +many number of its surroundable life +it's non-runnerable they don't see and + + align:start position:0% +it's non-runnerable they don't see and + + + align:start position:0% +it's non-runnerable they don't see and +they don't they don't use the fact that + + align:start position:0% +they don't they don't use the fact that + + + align:start position:0% +they don't they don't use the fact that +it is rendable + + align:start position:0% +it is rendable + + + align:start position:0% +it is rendable +so the market kids have strategies that + + align:start position:0% +so the market kids have strategies that + + + align:start position:0% +so the market kids have strategies that +they can uh they can fall back to when + + align:start position:0% +they can uh they can fall back to when + + + align:start position:0% +they can uh they can fall back to when +the strategy is applicable they only + + align:start position:0% +the strategy is applicable they only + + + align:start position:0% +the strategy is applicable they only +think the Indian the school kids can do + + align:start position:0% +think the Indian the school kids can do + + + align:start position:0% +think the Indian the school kids can do +is just write down a bunch of numbers + + align:start position:0% + + + + align:start position:0% + +and some of them might have figured out + + align:start position:0% +and some of them might have figured out + + + align:start position:0% +and some of them might have figured out +how to you know the algorithm you know + + align:start position:0% +how to you know the algorithm you know + + + align:start position:0% +how to you know the algorithm you know +these guys actually wrote it up this is + + align:start position:0% +these guys actually wrote it up this is + + + align:start position:0% +these guys actually wrote it up this is +it is written up properly so these guys + + align:start position:0% +it is written up properly so these guys + + + align:start position:0% +it is written up properly so these guys +know how to to do addition in a standard + + align:start position:0% +know how to to do addition in a standard + + + align:start position:0% +know how to to do addition in a standard +algorithmic way although he hasn't + + align:start position:0% +algorithmic way although he hasn't + + + align:start position:0% +algorithmic way although he hasn't +filled out the multiplication yet which + + align:start position:0% +filled out the multiplication yet which + + + align:start position:0% +filled out the multiplication yet which +finally Clips him up because + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% +um + + + align:start position:0% +um +so the problem is deeper than the school + + align:start position:0% +so the problem is deeper than the school + + + align:start position:0% +so the problem is deeper than the school +not teaching much + + align:start position:0% +not teaching much + + + align:start position:0% +not teaching much +is that they uh don't recognize that + + align:start position:0% +is that they uh don't recognize that + + + align:start position:0% +is that they uh don't recognize that +there is existing knowledge uh abstract + + align:start position:0% +there is existing knowledge uh abstract + + + align:start position:0% +there is existing knowledge uh abstract +and concrete these kids + + align:start position:0% +and concrete these kids + + + align:start position:0% +and concrete these kids +uh in the market they have knowledge + + align:start position:0% +uh in the market they have knowledge + + + align:start position:0% +uh in the market they have knowledge +they know how to do mathematics to + + align:start position:0% +they know how to do mathematics to + + + align:start position:0% +they know how to do mathematics to +school is the schooling in in this + + align:start position:0% +school is the schooling in in this + + + align:start position:0% +school is the schooling in in this +instance impersonated by the the + + align:start position:0% +instance impersonated by the the + + + align:start position:0% +instance impersonated by the the +school-like presentation of the Assa + + align:start position:0% +school-like presentation of the Assa + + + align:start position:0% +school-like presentation of the Assa +problem + + align:start position:0% +problem + + + align:start position:0% +problem +is unable to leverage that and basically + + align:start position:0% +is unable to leverage that and basically + + + align:start position:0% +is unable to leverage that and basically +what happens is that they see the thing + + align:start position:0% +what happens is that they see the thing + + + align:start position:0% +what happens is that they see the thing +and they say I'm not good at math + + align:start position:0% +and they say I'm not good at math + + + align:start position:0% +and they say I'm not good at math +I'm not I'm not uh I don't know how to + + align:start position:0% +I'm not I'm not uh I don't know how to + + + align:start position:0% +I'm not I'm not uh I don't know how to +do these things and the as soon as they + + align:start position:0% +do these things and the as soon as they + + + align:start position:0% +do these things and the as soon as they +see a written problem or even if you + + align:start position:0% +see a written problem or even if you + + + align:start position:0% +see a written problem or even if you +tell them or early the written problem + + align:start position:0% +tell them or early the written problem + + + align:start position:0% +tell them or early the written problem +because oral versus written doesn't make + + align:start position:0% +because oral versus written doesn't make + + + align:start position:0% +because oral versus written doesn't make +a difference there if they see an + + align:start position:0% +a difference there if they see an + + + align:start position:0% +a difference there if they see an +abstract problem in their mind what it + + align:start position:0% +abstract problem in their mind what it + + + align:start position:0% +abstract problem in their mind what it +evokes is that oh I better take out my + + align:start position:0% +evokes is that oh I better take out my + + + align:start position:0% +evokes is that oh I better take out my +you know toolbox of algorithm that I + + align:start position:0% +you know toolbox of algorithm that I + + + align:start position:0% +you know toolbox of algorithm that I +learned in school for how to teach this + + align:start position:0% +learned in school for how to teach this + + + align:start position:0% +learned in school for how to teach this +thing but in fact they are you know they + + align:start position:0% +thing but in fact they are you know they + + + align:start position:0% +thing but in fact they are you know they +misunderstood the algorithm to for + + align:start position:0% +misunderstood the algorithm to for + + + align:start position:0% +misunderstood the algorithm to for +example they do the subtraction in this + + align:start position:0% +example they do the subtraction in this + + + align:start position:0% +example they do the subtraction in this +algorithmic way but from the wrong part + + align:start position:0% +algorithmic way but from the wrong part + + + align:start position:0% +algorithmic way but from the wrong part +of the end or they do place value errors + + align:start position:0% +of the end or they do place value errors + + + align:start position:0% +of the end or they do place value errors +Etc + + align:start position:0% +Etc + + + align:start position:0% +Etc +that they never do in their real job + + align:start position:0% +that they never do in their real job + + + align:start position:0% +that they never do in their real job +because they + + align:start position:0% +because they + + + align:start position:0% +because they +they don't go back to this kind of + + align:start position:0% +they don't go back to this kind of + + + align:start position:0% +they don't go back to this kind of +half-baked algorithm that they have + + align:start position:0% +half-baked algorithm that they have + + + align:start position:0% +half-baked algorithm that they have +that they have learned + + align:start position:0% +that they have learned + + + align:start position:0% +that they have learned +um + + align:start position:0% +um + + + align:start position:0% +um +so the school is unable to + + align:start position:0% +so the school is unable to + + + align:start position:0% +so the school is unable to +kind of see what's in right in front of + + align:start position:0% +kind of see what's in right in front of + + + align:start position:0% +kind of see what's in right in front of +it that the skills have these kids have + + align:start position:0% +it that the skills have these kids have + + + align:start position:0% +it that the skills have these kids have +the skills and they just but they don't + + align:start position:0% +the skills and they just but they don't + + + align:start position:0% +the skills and they just but they don't +their skills are not sufficient because + + align:start position:0% +their skills are not sufficient because + + + align:start position:0% +their skills are not sufficient because +they need to be able to go from this + + align:start position:0% +they need to be able to go from this + + + align:start position:0% +they need to be able to go from this +day-to-day apps you know manipulation of + + align:start position:0% +day-to-day apps you know manipulation of + + + align:start position:0% +day-to-day apps you know manipulation of +arithmetic tomorrow do you do need to go + + align:start position:0% +arithmetic tomorrow do you do need to go + + + align:start position:0% +arithmetic tomorrow do you do need to go +you do need to be able to go through the + + align:start position:0% +you do need to be able to go through the + + + align:start position:0% +you do need to be able to go through the +abstraction if you're going to do + + align:start position:0% +abstraction if you're going to do + + + align:start position:0% +abstraction if you're going to do +something more than doing a market kit + + align:start position:0% +something more than doing a market kit + + + align:start position:0% +something more than doing a market kit +you cannot learn algebra without + + align:start position:0% +you cannot learn algebra without + + + align:start position:0% +you cannot learn algebra without +understanding attraction + + align:start position:0% +understanding attraction + + + align:start position:0% +understanding attraction +but the school has come is completely + + align:start position:0% +but the school has come is completely + + + align:start position:0% +but the school has come is completely +unable to do this to do this transition + + align:start position:0% +unable to do this to do this transition + + + align:start position:0% +unable to do this to do this transition +and then on the other side is whatever + + align:start position:0% +and then on the other side is whatever + + + align:start position:0% +and then on the other side is whatever +schools teaches is completely useless + + align:start position:0% +schools teaches is completely useless + + + align:start position:0% +schools teaches is completely useless +for life because these poor kids who are + + align:start position:0% +for life because these poor kids who are + + + align:start position:0% +for life because these poor kids who are +school kids who are very good at doing + + align:start position:0% +school kids who are very good at doing + + + align:start position:0% +school kids who are very good at doing +are relatively good at doing the SR math + + align:start position:0% +are relatively good at doing the SR math + + + align:start position:0% +are relatively good at doing the SR math +one thing I didn't tell you is not only + + align:start position:0% +one thing I didn't tell you is not only + + + align:start position:0% +one thing I didn't tell you is not only +they get the market transaction right + + align:start position:0% +they get the market transaction right + + + align:start position:0% +they get the market transaction right +but it takes about 15 minutes for them + + align:start position:0% +but it takes about 15 minutes for them + + + align:start position:0% +but it takes about 15 minutes for them +to do the calculation because they have + + align:start position:0% +to do the calculation because they have + + + align:start position:0% +to do the calculation because they have +unlimited time so in 15 minutes they + + align:start position:0% +unlimited time so in 15 minutes they + + + align:start position:0% +unlimited time so in 15 minutes they +would have been you know run out of the + + align:start position:0% +would have been you know run out of the + + + align:start position:0% +would have been you know run out of the +market + + align:start position:0% +market + + + align:start position:0% +market +so they couldn't like whatever they have + + align:start position:0% +so they couldn't like whatever they have + + + align:start position:0% +so they couldn't like whatever they have +learned is not useful and in fact + + align:start position:0% +learned is not useful and in fact + + + align:start position:0% +learned is not useful and in fact +pratam did an assert survey for middle + + align:start position:0% +pratam did an assert survey for middle + + + align:start position:0% +pratam did an assert survey for middle +school students where they asked them + + align:start position:0% +school students where they asked them + + + align:start position:0% +school students where they asked them +things like you know + + align:start position:0% +things like you know + + + align:start position:0% +things like you know +um you have a bag of you have a bag of + + align:start position:0% +um you have a bag of you have a bag of + + + align:start position:0% +um you have a bag of you have a bag of +fertilizer that is uh enough for a field + + align:start position:0% +fertilizer that is uh enough for a field + + + align:start position:0% +fertilizer that is uh enough for a field +of three acre + + align:start position:0% +of three acre + + + align:start position:0% +of three acre +uh you know you you're + + align:start position:0% +uh you know you you're + + + align:start position:0% +uh you know you you're +your field is one and a half acre how + + align:start position:0% +your field is one and a half acre how + + + align:start position:0% +your field is one and a half acre how +much of the back of fertilizer should + + align:start position:0% +much of the back of fertilizer should + + + align:start position:0% +much of the back of fertilizer should +you use + + align:start position:0% +you use + + + align:start position:0% +you use +and the the kids are terrible at doing + + align:start position:0% +and the the kids are terrible at doing + + + align:start position:0% +and the the kids are terrible at doing +that + + align:start position:0% +that + + + align:start position:0% +that +and even when they even the ones who can + + align:start position:0% +and even when they even the ones who can + + + align:start position:0% +and even when they even the ones who can +do division can still not do that do + + align:start position:0% +do division can still not do that do + + + align:start position:0% +do division can still not do that do +this type of so this is kind of a + + align:start position:0% +this type of so this is kind of a + + + align:start position:0% +this type of so this is kind of a +parallel thing of the whatever abstract + + align:start position:0% +parallel thing of the whatever abstract + + + align:start position:0% +parallel thing of the whatever abstract +so the concrete knowledge is not + + align:start position:0% +so the concrete knowledge is not + + + align:start position:0% +so the concrete knowledge is not +translated by the schools to abstract + + align:start position:0% +translated by the schools to abstract + + + align:start position:0% +translated by the schools to abstract +knowledge that would enable you to go + + align:start position:0% +knowledge that would enable you to go + + + align:start position:0% +knowledge that would enable you to go +further and the abstract knowledge that + + align:start position:0% +further and the abstract knowledge that + + + align:start position:0% +further and the abstract knowledge that +is impacted is not + + align:start position:0% +is impacted is not + + + align:start position:0% +is impacted is not +usable in a concrete way yeah + + align:start position:0% + + + + align:start position:0% + +outcomes part of your children as much + + align:start position:0% +outcomes part of your children as much + + + align:start position:0% +outcomes part of your children as much +but the outcomes that the market + + align:start position:0% +but the outcomes that the market + + + align:start position:0% +but the outcomes that the market +shouldn't have are I wonder if they're + + align:start position:0% +shouldn't have are I wonder if they're + + + align:start position:0% +shouldn't have are I wonder if they're +actually related to accessing knowledge + + align:start position:0% +actually related to accessing knowledge + + + align:start position:0% +actually related to accessing knowledge +or something that they have no problems + + align:start position:0% +or something that they have no problems + + + align:start position:0% +or something that they have no problems +that they have learned on the job over + + align:start position:0% +that they have learned on the job over + + + align:start position:0% +that they have learned on the job over +the years so it's really been unfair to + + align:start position:0% +the years so it's really been unfair to + + + align:start position:0% +the years so it's really been unfair to +what it existing knowledge but something + + align:start position:0% +what it existing knowledge but something + + + align:start position:0% +what it existing knowledge but something +that we have knowledge yes but it's + + align:start position:0% +that we have knowledge yes but it's + + + align:start position:0% +that we have knowledge yes but it's +existing now right about two-thirds of + + align:start position:0% +existing now right about two-thirds of + + + align:start position:0% +existing now right about two-thirds of +these kids are in school the market kids + + align:start position:0% +these kids are in school the market kids + + + align:start position:0% +these kids are in school the market kids +are still in school so whatever maybe + + align:start position:0% +are still in school so whatever maybe + + + align:start position:0% +are still in school so whatever maybe +they took a long time to acquire it but + + align:start position:0% +they took a long time to acquire it but + + + align:start position:0% +they took a long time to acquire it but +now they have it and they are still they + + align:start position:0% +now they have it and they are still they + + + align:start position:0% +now they have it and they are still they +still can't do the SR test they have it + + align:start position:0% +still can't do the SR test they have it + + + align:start position:0% +still can't do the SR test they have it +in school the school could kind of use + + align:start position:0% +in school the school could kind of use + + + align:start position:0% +in school the school could kind of use +it + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +so do you think that this is a more of + + align:start position:0% +so do you think that this is a more of + + + align:start position:0% +so do you think that this is a more of +an issue with like the pedagogy of what + + align:start position:0% +an issue with like the pedagogy of what + + + align:start position:0% +an issue with like the pedagogy of what +the teachers are doing or do you think + + align:start position:0% +the teachers are doing or do you think + + + align:start position:0% +the teachers are doing or do you think +it's more of a measurement issue about + + align:start position:0% +it's more of a measurement issue about + + + align:start position:0% +it's more of a measurement issue about +like the Acer like things should be + + align:start position:0% +like the Acer like things should be + + + align:start position:0% +like the Acer like things should be +trying to measure different things or + + align:start position:0% +trying to measure different things or + + + align:start position:0% +trying to measure different things or +testing in ways like which of these two + + align:start position:0% +testing in ways like which of these two + + + align:start position:0% +testing in ways like which of these two +do you think it is or like which is more + + align:start position:0% +do you think it is or like which is more + + + align:start position:0% +do you think it is or like which is more +important both in a way which is on the + + align:start position:0% +important both in a way which is on the + + + align:start position:0% +important both in a way which is on the +one hand + + align:start position:0% +one hand + + + align:start position:0% +one hand +I do think that it's useful to know both + + align:start position:0% +I do think that it's useful to know both + + + align:start position:0% +I do think that it's useful to know both +for the SR testing but also for + + align:start position:0% +for the SR testing but also for + + + align:start position:0% +for the SR testing but also for +employers for example that they could + + align:start position:0% +employers for example that they could + + + align:start position:0% +employers for example that they could +start testing people that they might + + align:start position:0% +start testing people that they might + + + align:start position:0% +start testing people that they might +want to hire with tests that are less + + align:start position:0% +want to hire with tests that are less + + + align:start position:0% +want to hire with tests that are less +dependent on understanding and ability + + align:start position:0% +dependent on understanding and ability + + + align:start position:0% +dependent on understanding and ability +to rehash + + align:start position:0% +to rehash + + + align:start position:0% +to rehash +rehash + + align:start position:0% + + + + align:start position:0% + +the abstract the way the way the + + align:start position:0% +the abstract the way the way the + + + align:start position:0% +the abstract the way the way the +mathematics is being taught in schools + + align:start position:0% +mathematics is being taught in schools + + + align:start position:0% +mathematics is being taught in schools +so that's true from us there that's true + + align:start position:0% +so that's true from us there that's true + + + align:start position:0% +so that's true from us there that's true +more even even more true for you know + + align:start position:0% +more even even more true for you know + + + align:start position:0% +more even even more true for you know +emphasis or you know they want software + + align:start position:0% +emphasis or you know they want software + + + align:start position:0% +emphasis or you know they want software +engineer + + align:start position:0% +engineer + + + align:start position:0% +engineer +they want you know smart people who do a + + align:start position:0% +they want you know smart people who do a + + + align:start position:0% +they want you know smart people who do a +lot of things clearly mediating it by + + align:start position:0% +lot of things clearly mediating it by + + + align:start position:0% +lot of things clearly mediating it by +performance in schools or even by is or + + align:start position:0% +performance in schools or even by is or + + + align:start position:0% +performance in schools or even by is or +even by how you do well at school type + + align:start position:0% +even by how you do well at school type + + + align:start position:0% +even by how you do well at school type +exam is a problem in fact you see some + + align:start position:0% +exam is a problem in fact you see some + + + align:start position:0% +exam is a problem in fact you see some +software company like Infosys to run + + align:start position:0% +software company like Infosys to run + + + align:start position:0% +software company like Infosys to run +sort of testing camps + + align:start position:0% +sort of testing camps + + + align:start position:0% +sort of testing camps +that are trying to capture another form + + align:start position:0% +that are trying to capture another form + + + align:start position:0% +that are trying to capture another form +of knowledge precisely to to to get + + align:start position:0% +of knowledge precisely to to to get + + + align:start position:0% +of knowledge precisely to to to get +around that I don't know how successful + + align:start position:0% +around that I don't know how successful + + + align:start position:0% +around that I don't know how successful +they are haven't seen the test but + + align:start position:0% +they are haven't seen the test but + + + align:start position:0% +they are haven't seen the test but +that's so that's a great point however + + align:start position:0% +that's so that's a great point however + + + align:start position:0% +that's so that's a great point however +the second point is do I see this as a + + align:start position:0% +the second point is do I see this as a + + + align:start position:0% +the second point is do I see this as a +point of pedagogy yes because + + align:start position:0% +point of pedagogy yes because + + + align:start position:0% +point of pedagogy yes because +it + + align:start position:0% +it + + + align:start position:0% +it +the school is it is important for people + + align:start position:0% +the school is it is important for people + + + align:start position:0% +the school is it is important for people +to learn to solve abstract problems + + align:start position:0% +to learn to solve abstract problems + + + align:start position:0% +to learn to solve abstract problems +because otherwise you're you're limited + + align:start position:0% +because otherwise you're you're limited + + + align:start position:0% +because otherwise you're you're limited +once Infosys higher these people are + + align:start position:0% +once Infosys higher these people are + + + align:start position:0% +once Infosys higher these people are +based on their + + align:start position:0% +based on their + + + align:start position:0% +based on their +non-school-like test I assume they start + + align:start position:0% +non-school-like test I assume they start + + + align:start position:0% +non-school-like test I assume they start +to tell them you know some abstract + + align:start position:0% +to tell them you know some abstract + + + align:start position:0% +to tell them you know some abstract +skills otherwise they would never be + + align:start position:0% +skills otherwise they would never be + + + align:start position:0% +skills otherwise they would never be +able to could + + align:start position:0% +able to could + + + align:start position:0% +able to could +um so + + align:start position:0% +um so + + + align:start position:0% +um so +so the schools also would need to be + + align:start position:0% +so the schools also would need to be + + + align:start position:0% +so the schools also would need to be +able to do that and also to to to to to + + align:start position:0% +able to do that and also to to to to to + + + align:start position:0% +able to do that and also to to to to to +help people use the abstract knowledge + + align:start position:0% +help people use the abstract knowledge + + + align:start position:0% +help people use the abstract knowledge +to apply the abstract knowledge in + + align:start position:0% +to apply the abstract knowledge in + + + align:start position:0% +to apply the abstract knowledge in +concrete situation seems to be part of + + align:start position:0% +concrete situation seems to be part of + + + align:start position:0% +concrete situation seems to be part of +the so I would say that this is a + + align:start position:0% +the so I would say that this is a + + + align:start position:0% +the so I would say that this is a +problem for both both things + + align:start position:0% +problem for both both things + + + align:start position:0% +problem for both both things +so that's the problem uh so the problem + + align:start position:0% +so that's the problem uh so the problem + + + align:start position:0% +so that's the problem uh so the problem +is deeper than the test scores are low + + align:start position:0% +is deeper than the test scores are low + + + align:start position:0% +is deeper than the test scores are low +that's what that's kind of what I was + + align:start position:0% +that's what that's kind of what I was + + + align:start position:0% +that's what that's kind of what I was +trying to say + + align:start position:0% +trying to say + + + align:start position:0% +trying to say +and so where does it come from + + align:start position:0% +and so where does it come from + + + align:start position:0% +and so where does it come from +so let me start by what it what it's not + + align:start position:0% +so let me start by what it what it's not + + + align:start position:0% +so let me start by what it what it's not +and sort of the general things that you + + align:start position:0% +and sort of the general things that you + + + align:start position:0% +and sort of the general things that you +hear + + align:start position:0% + + + + align:start position:0% + +if you have an Indian if you ask Indian + + align:start position:0% +if you have an Indian if you ask Indian + + + align:start position:0% +if you have an Indian if you ask Indian +teachers they'll always blame the + + align:start position:0% +teachers they'll always blame the + + + align:start position:0% +teachers they'll always blame the +parents or the kids + + align:start position:0% +parents or the kids + + + align:start position:0% +parents or the kids +I think basically some version of the + + align:start position:0% +I think basically some version of the + + + align:start position:0% +I think basically some version of the +kids don't want to learn or they are + + align:start position:0% +kids don't want to learn or they are + + + align:start position:0% +kids don't want to learn or they are +lazy or they are not too smart + + align:start position:0% +lazy or they are not too smart + + + align:start position:0% +lazy or they are not too smart +um to they can't learn + + align:start position:0% +um to they can't learn + + + align:start position:0% +um to they can't learn +so that's of course Very uh patronizing + + align:start position:0% +so that's of course Very uh patronizing + + + align:start position:0% +so that's of course Very uh patronizing +but it's actually more frequent than you + + align:start position:0% +but it's actually more frequent than you + + + align:start position:0% +but it's actually more frequent than you +hear for example Bill Gates had the + + align:start position:0% +hear for example Bill Gates had the + + + align:start position:0% +hear for example Bill Gates had the +whole thing + + align:start position:0% +whole thing + + + align:start position:0% +whole thing +on a nutrition program for young kids + + align:start position:0% +on a nutrition program for young kids + + + align:start position:0% +on a nutrition program for young kids +and basically he explained that school + + align:start position:0% +and basically he explained that school + + + align:start position:0% +and basically he explained that school +performance is low because kids are + + align:start position:0% +performance is low because kids are + + + align:start position:0% +performance is low because kids are +undernourished and therefore they can't + + align:start position:0% +undernourished and therefore they can't + + + align:start position:0% +undernourished and therefore they can't +learn which is basically the same you + + align:start position:0% +learn which is basically the same you + + + align:start position:0% +learn which is basically the same you +know sort of politically correct + + align:start position:0% +know sort of politically correct + + + align:start position:0% +know sort of politically correct +argument of the same version + + align:start position:0% +argument of the same version + + + align:start position:0% +argument of the same version +so I don't think it's that why I don't + + align:start position:0% +so I don't think it's that why I don't + + + align:start position:0% +so I don't think it's that why I don't +think it's that because of my preschool + + align:start position:0% +think it's that because of my preschool + + + align:start position:0% +think it's that because of my preschool +mathematician + + align:start position:0% +mathematician + + + align:start position:0% +mathematician +I'm taking those kids I'm learning them + + align:start position:0% +I'm taking those kids I'm learning them + + + align:start position:0% +I'm taking those kids I'm learning them +exactly I'm teaching them the same thing + + align:start position:0% +exactly I'm teaching them the same thing + + + align:start position:0% +exactly I'm teaching them the same thing +that the Cambridge kids teach and they + + align:start position:0% +that the Cambridge kids teach and they + + + align:start position:0% +that the Cambridge kids teach and they +are just as good when they were four so + + align:start position:0% +are just as good when they were four so + + + align:start position:0% +are just as good when they were four so +something has happened to them later + + align:start position:0% +something has happened to them later + + + align:start position:0% +something has happened to them later +so I don't believe you you cannot learn + + align:start position:0% +so I don't believe you you cannot learn + + + align:start position:0% +so I don't believe you you cannot learn +you cannot learn strategy + + align:start position:0% +you cannot learn strategy + + + align:start position:0% +you cannot learn strategy +that's one another thing you hear often + + align:start position:0% +that's one another thing you hear often + + + align:start position:0% +that's one another thing you hear often +especially in the education world is + + align:start position:0% +especially in the education world is + + + align:start position:0% +especially in the education world is +that it's all about resources the the + + align:start position:0% +that it's all about resources the the + + + align:start position:0% +that it's all about resources the the +the the systems are under resourced uh + + align:start position:0% +the the systems are under resourced uh + + + align:start position:0% +the the systems are under resourced uh +the teacher salary is too low and also + + align:start position:0% +the teacher salary is too low and also + + + align:start position:0% +the teacher salary is too low and also +there are no textbooks flip charts + + align:start position:0% +there are no textbooks flip charts + + + align:start position:0% +there are no textbooks flip charts +computers and so on and so forth in the + + align:start position:0% +computers and so on and so forth in the + + + align:start position:0% +computers and so on and so forth in the +school + + align:start position:0% +school + + + align:start position:0% +school +so we know a bunch about that because + + align:start position:0% +so we know a bunch about that because + + + align:start position:0% +so we know a bunch about that because +that's these are precisely where you + + align:start position:0% +that's these are precisely where you + + + align:start position:0% +that's these are precisely where you +have this like huge cluster of + + align:start position:0% +have this like huge cluster of + + + align:start position:0% +have this like huge cluster of +experiments that have been conducted + + align:start position:0% +experiments that have been conducted + + + align:start position:0% +experiments that have been conducted +over the year + + align:start position:0% +over the year + + + align:start position:0% +over the year +and what do we know well number one yeah + + align:start position:0% +and what do we know well number one yeah + + + align:start position:0% +and what do we know well number one yeah +and just thinking also about the issue + + align:start position:0% +and just thinking also about the issue + + + align:start position:0% +and just thinking also about the issue +you brought up earlier in lecture about + + align:start position:0% +you brought up earlier in lecture about + + + align:start position:0% +you brought up earlier in lecture about +attendance is there any argument or + + align:start position:0% +attendance is there any argument or + + + align:start position:0% +attendance is there any argument or +evidence in favor of attendance being + + align:start position:0% +evidence in favor of attendance being + + + align:start position:0% +evidence in favor of attendance being +faster as well where maybe there's + + align:start position:0% +faster as well where maybe there's + + + align:start position:0% +faster as well where maybe there's +secondary contacts return so you can go + + align:start position:0% +secondary contacts return so you can go + + + align:start position:0% +secondary contacts return so you can go +every day you can have a lot but if + + align:start position:0% +every day you can have a lot but if + + + align:start position:0% +every day you can have a lot but if +you're always starting there there is + + align:start position:0% +you're always starting there there is + + + align:start position:0% +you're always starting there there is +when kids go more to school in Israel + + align:start position:0% +when kids go more to school in Israel + + + align:start position:0% +when kids go more to school in Israel +because they are more present or they + + align:start position:0% +because they are more present or they + + + align:start position:0% +because they are more present or they +are Sharma president + + align:start position:0% +are Sharma president + + + align:start position:0% +are Sharma president +so there is something a little bit of + + align:start position:0% +so there is something a little bit of + + + align:start position:0% +so there is something a little bit of +something that happens in every day of + + align:start position:0% +something that happens in every day of + + + align:start position:0% +something that happens in every day of +school when kids are in early school + + align:start position:0% +school when kids are in early school + + + align:start position:0% +school when kids are in early school +they also learn more so something is + + align:start position:0% +they also learn more so something is + + + align:start position:0% +they also learn more so something is +happening so there is some amount of + + align:start position:0% +happening so there is some amount of + + + align:start position:0% +happening so there is some amount of +learning that's happening and you get + + align:start position:0% +learning that's happening and you get + + + align:start position:0% +learning that's happening and you get +fewer days of school you get fewer days + + align:start position:0% +fewer days of school you get fewer days + + + align:start position:0% +fewer days of school you get fewer days +of that and we saw it in you know it + + align:start position:0% +of that and we saw it in you know it + + + align:start position:0% +of that and we saw it in you know it +makes a big difference to to have a + + align:start position:0% +makes a big difference to to have a + + + align:start position:0% +makes a big difference to to have a +covet and and there is no school so + + align:start position:0% +covet and and there is no school so + + + align:start position:0% +covet and and there is no school so +something is happening in the school not + + align:start position:0% +something is happening in the school not + + + align:start position:0% +something is happening in the school not +nothing and then therefore attendance + + align:start position:0% +nothing and then therefore attendance + + + align:start position:0% +nothing and then therefore attendance +matters but + + align:start position:0% +matters but + + + align:start position:0% +matters but +maybe not as much as should be happening + + align:start position:0% +maybe not as much as should be happening + + + align:start position:0% +maybe not as much as should be happening +is what kind of what we are + + align:start position:0% +is what kind of what we are + + + align:start position:0% +is what kind of what we are +so the argument that teachers are poorly + + align:start position:0% +so the argument that teachers are poorly + + + align:start position:0% +so the argument that teachers are poorly +paid it definitely holds for France + + align:start position:0% +paid it definitely holds for France + + + align:start position:0% +paid it definitely holds for France +where teachers are very very poorly paid + + align:start position:0% +where teachers are very very poorly paid + + + align:start position:0% +where teachers are very very poorly paid +as a function of their education + + align:start position:0% +as a function of their education + + + align:start position:0% +as a function of their education +I think it holds in the U.S so someone + + align:start position:0% +I think it holds in the U.S so someone + + + align:start position:0% +I think it holds in the U.S so someone +would need to check that it does not + + align:start position:0% +would need to check that it does not + + + align:start position:0% +would need to check that it does not +hold in India + + align:start position:0% +hold in India + + + align:start position:0% +hold in India +where the the salary of a teacher uh you + + align:start position:0% +where the the salary of a teacher uh you + + + align:start position:0% +where the the salary of a teacher uh you +know in the distribution is super high + + align:start position:0% +know in the distribution is super high + + + align:start position:0% +know in the distribution is super high +and conditional on their on their + + align:start position:0% +and conditional on their on their + + + align:start position:0% +and conditional on their on their +education event is super high and after + + align:start position:0% +education event is super high and after + + + align:start position:0% +education event is super high and after +all we saw in Ghana how everybody is + + align:start position:0% +all we saw in Ghana how everybody is + + + align:start position:0% +all we saw in Ghana how everybody is +desperate to be a teacher because it's + + align:start position:0% +desperate to be a teacher because it's + + + align:start position:0% +desperate to be a teacher because it's +such a is such a rent seeking rent + + align:start position:0% +such a is such a rent seeking rent + + + align:start position:0% +such a is such a rent seeking rent +paying occupation + + align:start position:0% +paying occupation + + + align:start position:0% +paying occupation +teacher salary in the in the public + + align:start position:0% +teacher salary in the in the public + + + align:start position:0% +teacher salary in the in the public +schools are also much higher than what + + align:start position:0% +schools are also much higher than what + + + align:start position:0% +schools are also much higher than what +they are paid in private school which + + align:start position:0% +they are paid in private school which + + + align:start position:0% +they are paid in private school which +suggests that there is a huge wedge + + align:start position:0% +suggests that there is a huge wedge + + + align:start position:0% +suggests that there is a huge wedge +there + + align:start position:0% +there + + + align:start position:0% +there +so + + align:start position:0% +so + + + align:start position:0% +so +the so it's it's very unlikely to be due + + align:start position:0% +the so it's it's very unlikely to be due + + + align:start position:0% +the so it's it's very unlikely to be due +to teach your salary and in fact there + + align:start position:0% +to teach your salary and in fact there + + + align:start position:0% +to teach your salary and in fact there +is an experiment by Karthik maldon and + + align:start position:0% +is an experiment by Karthik maldon and + + + align:start position:0% +is an experiment by Karthik maldon and +others that demonstrated that in + + align:start position:0% +others that demonstrated that in + + + align:start position:0% +others that demonstrated that in +Indonesia super electrical experiment + + align:start position:0% +Indonesia super electrical experiment + + + align:start position:0% +Indonesia super electrical experiment +where the teacher salary was doubled + + align:start position:0% +where the teacher salary was doubled + + + align:start position:0% +where the teacher salary was doubled +and the impact on test causes nothing + + align:start position:0% +and the impact on test causes nothing + + + align:start position:0% +and the impact on test causes nothing +immediately nothing as you select more + + align:start position:0% +immediately nothing as you select more + + + align:start position:0% +immediately nothing as you select more +teachers and better teachers into the + + align:start position:0% +teachers and better teachers into the + + + align:start position:0% +teachers and better teachers into the +job + + align:start position:0% +job + + + align:start position:0% +job +so there's just no effect on teacher + + align:start position:0% +so there's just no effect on teacher + + + align:start position:0% +so there's just no effect on teacher +papers yeah + + align:start position:0% +papers yeah + + + align:start position:0% +papers yeah +[Music] + + align:start position:0% + + + + align:start position:0% + +yeah so I'll go to incentives uh in a + + align:start position:0% +yeah so I'll go to incentives uh in a + + + align:start position:0% +yeah so I'll go to incentives uh in a +moment + + align:start position:0% +moment + + + align:start position:0% +moment +um + + align:start position:0% +um + + + align:start position:0% +um +before that in fact I'll go to incentive + + align:start position:0% +before that in fact I'll go to incentive + + + align:start position:0% +before that in fact I'll go to incentive +right away before that other resources + + align:start position:0% +right away before that other resources + + + align:start position:0% +right away before that other resources +so that's where this is like this line + + align:start position:0% +so that's where this is like this line + + + align:start position:0% +so that's where this is like this line +was about like + + align:start position:0% +was about like + + + align:start position:0% +was about like +20 years of research and education + + align:start position:0% +20 years of research and education + + + align:start position:0% +20 years of research and education +trying everything from + + align:start position:0% +trying everything from + + + align:start position:0% +trying everything from +textbooks to cutting class size into to + + align:start position:0% +textbooks to cutting class size into to + + + align:start position:0% +textbooks to cutting class size into to +anything you can think of any inputs + + align:start position:0% +anything you can think of any inputs + + + align:start position:0% +anything you can think of any inputs +except computers and I'll go back to the + + align:start position:0% +except computers and I'll go back to the + + + align:start position:0% +except computers and I'll go back to the +computers in a minute none of that makes + + align:start position:0% +computers in a minute none of that makes + + + align:start position:0% +computers in a minute none of that makes +any difference in fact the famous you + + align:start position:0% +any difference in fact the famous you + + + align:start position:0% +any difference in fact the famous you +know Michael Kramer textbook paper + + align:start position:0% +know Michael Kramer textbook paper + + + align:start position:0% +know Michael Kramer textbook paper +that's sort of launched us all + + align:start position:0% +that's sort of launched us all + + + align:start position:0% +that's sort of launched us all +was an extremely surprising result to + + align:start position:0% +was an extremely surprising result to + + + align:start position:0% +was an extremely surprising result to +even to to him and to all of us because + + align:start position:0% +even to to him and to all of us because + + + align:start position:0% +even to to him and to all of us because +it took no impact of providing textbooks + + align:start position:0% +it took no impact of providing textbooks + + + align:start position:0% +it took no impact of providing textbooks +in Kenyan school that didn't have + + align:start position:0% +in Kenyan school that didn't have + + + align:start position:0% +in Kenyan school that didn't have +textbooks so it's not about stuff it's + + align:start position:0% +textbooks so it's not about stuff it's + + + align:start position:0% +textbooks so it's not about stuff it's +not about teacher money it's not about + + align:start position:0% +not about teacher money it's not about + + + align:start position:0% +not about teacher money it's not about +things in the classes uh then you have + + align:start position:0% +things in the classes uh then you have + + + align:start position:0% +things in the classes uh then you have +like + + align:start position:0% +like + + + align:start position:0% +like +the incident the economists sort of + + align:start position:0% +the incident the economists sort of + + + align:start position:0% +the incident the economists sort of +knee-jerk reaction to the the first one + + align:start position:0% +knee-jerk reaction to the the first one + + + align:start position:0% +knee-jerk reaction to the the first one +about kids can't learn is the teachers + + align:start position:0% +about kids can't learn is the teachers + + + align:start position:0% +about kids can't learn is the teachers +need Jack reaction the second one is the + + align:start position:0% +need Jack reaction the second one is the + + + align:start position:0% +need Jack reaction the second one is the +you know Oxfam teacher reaction + + align:start position:0% +you know Oxfam teacher reaction + + + align:start position:0% +you know Oxfam teacher reaction +knee-jack reaction the incentive with + + align:start position:0% +knee-jack reaction the incentive with + + + align:start position:0% +knee-jack reaction the incentive with +the economist knee jock reaction it's + + align:start position:0% +the economist knee jock reaction it's + + + align:start position:0% +the economist knee jock reaction it's +got to be insensive + + align:start position:0% +got to be insensive + + + align:start position:0% +got to be insensive +and it's true that directive incentives + + align:start position:0% +and it's true that directive incentives + + + align:start position:0% +and it's true that directive incentives +to specific things has a small effect + + align:start position:0% +to specific things has a small effect + + + align:start position:0% +to specific things has a small effect +some effect for example uh going back to + + align:start position:0% +some effect for example uh going back to + + + align:start position:0% +some effect for example uh going back to +the attendance question you asked we + + align:start position:0% +the attendance question you asked we + + + align:start position:0% +the attendance question you asked we +have a paper with + + align:start position:0% +have a paper with + + + align:start position:0% +have a paper with +Stephen Ryan looking at providing + + align:start position:0% +Stephen Ryan looking at providing + + + align:start position:0% +Stephen Ryan looking at providing +incentives to teachers to show up + + align:start position:0% +incentives to teachers to show up + + + align:start position:0% +incentives to teachers to show up +and then if you give them incentive to + + align:start position:0% +and then if you give them incentive to + + + align:start position:0% +and then if you give them incentive to +show up more they show up more and if + + align:start position:0% +show up more they show up more and if + + + align:start position:0% +show up more they show up more and if +they show up more the kids learn more so + + align:start position:0% +they show up more the kids learn more so + + + align:start position:0% +they show up more the kids learn more so +that's that makes sense + + align:start position:0% +that's that makes sense + + + align:start position:0% +that's that makes sense +there is also a number of people based + + align:start position:0% +there is also a number of people based + + + align:start position:0% +there is also a number of people based +on providing incentive for test scores + + align:start position:0% +on providing incentive for test scores + + + align:start position:0% +on providing incentive for test scores +and then the literature is a bit more + + align:start position:0% +and then the literature is a bit more + + + align:start position:0% +and then the literature is a bit more +key some papers for example Michael + + align:start position:0% +key some papers for example Michael + + + align:start position:0% +key some papers for example Michael +Kramer shows that if you give incentive + + align:start position:0% +Kramer shows that if you give incentive + + + align:start position:0% +Kramer shows that if you give incentive +based on test scores + + align:start position:0% +based on test scores + + + align:start position:0% +based on test scores +you improve test scores that are + + align:start position:0% +you improve test scores that are + + + align:start position:0% +you improve test scores that are +targeted but you don't improve you + + align:start position:0% +targeted but you don't improve you + + + align:start position:0% +targeted but you don't improve you +improve the the performance on the exact + + align:start position:0% +improve the the performance on the exact + + + align:start position:0% +improve the the performance on the exact +test that is being targeted but not on + + align:start position:0% +test that is being targeted but not on + + + align:start position:0% +test that is being targeted but not on +any other measures of learning + + align:start position:0% +any other measures of learning + + + align:start position:0% +any other measures of learning +um to and then Karthik as another people + + align:start position:0% +um to and then Karthik as another people + + + align:start position:0% +um to and then Karthik as another people +that very argue that no no there is some + + align:start position:0% +that very argue that no no there is some + + + align:start position:0% +that very argue that no no there is some +gain in actual learning coming from the + + align:start position:0% +gain in actual learning coming from the + + + align:start position:0% +gain in actual learning coming from the +incentive so there is a bit of a dispute + + align:start position:0% +incentive so there is a bit of a dispute + + + align:start position:0% +incentive so there is a bit of a dispute +there + + align:start position:0% +there + + + align:start position:0% +there +it's a bit in the eyes of the beholder + + align:start position:0% +it's a bit in the eyes of the beholder + + + align:start position:0% +it's a bit in the eyes of the beholder +but I'll go into that if you give + + align:start position:0% +but I'll go into that if you give + + + align:start position:0% +but I'll go into that if you give +incentive on test scores there's going + + align:start position:0% +incentive on test scores there's going + + + align:start position:0% +incentive on test scores there's going +to be some increase in test scores + + align:start position:0% +to be some increase in test scores + + + align:start position:0% +to be some increase in test scores +now + + align:start position:0% +now + + + align:start position:0% +now +we can just put that aside and say well + + align:start position:0% +we can just put that aside and say well + + + align:start position:0% +we can just put that aside and say well +providing incentives to teachers on in + + align:start position:0% +providing incentives to teachers on in + + + align:start position:0% +providing incentives to teachers on in +public schools who are otherwise not + + align:start position:0% +public schools who are otherwise not + + + align:start position:0% +public schools who are otherwise not +very well incentivized + + align:start position:0% +very well incentivized + + + align:start position:0% +very well incentivized +is much less incentive than just the + + align:start position:0% +is much less incentive than just the + + + align:start position:0% +is much less incentive than just the +private schools you would think the + + align:start position:0% +private schools you would think the + + + align:start position:0% +private schools you would think the +private schools are the ones that are + + align:start position:0% +private schools are the ones that are + + + align:start position:0% +private schools are the ones that are +completely incentivized and in fact + + align:start position:0% +completely incentivized and in fact + + + align:start position:0% +completely incentivized and in fact +there is a literature in particular with + + align:start position:0% +there is a literature in particular with + + + align:start position:0% +there is a literature in particular with +jishnu by jishnu Das and Asim that is + + align:start position:0% +jishnu by jishnu Das and Asim that is + + + align:start position:0% +jishnu by jishnu Das and Asim that is +all about the fact that people parents + + align:start position:0% +all about the fact that people parents + + + align:start position:0% +all about the fact that people parents +are super + + align:start position:0% +are super + + + align:start position:0% +are super +demanding as customers and if they see + + align:start position:0% +demanding as customers and if they see + + + align:start position:0% +demanding as customers and if they see +that the performance of the school is + + align:start position:0% +that the performance of the school is + + + align:start position:0% +that the performance of the school is +low in the sense that they see low test + + align:start position:0% +low in the sense that they see low test + + + align:start position:0% +low in the sense that they see low test +scores around them they move the kids + + align:start position:0% +scores around them they move the kids + + + align:start position:0% +scores around them they move the kids +and so the you would think the private + + align:start position:0% +and so the you would think the private + + + align:start position:0% +and so the you would think the private +schools are where you would find + + align:start position:0% +schools are where you would find + + + align:start position:0% +schools are where you would find +that where the ins incentives are very + + align:start position:0% +that where the ins incentives are very + + + align:start position:0% +that where the ins incentives are very +steep + + align:start position:0% + + + + align:start position:0% + +let me know if you have like the supply + + align:start position:0% +let me know if you have like the supply + + + align:start position:0% +let me know if you have like the supply +of teachers in the sense that like how + + align:start position:0% +of teachers in the sense that like how + + + align:start position:0% +of teachers in the sense that like how +they are educated to begin with how are + + align:start position:0% +they are educated to begin with how are + + + align:start position:0% +they are educated to begin with how are +the teachers are educated themselves uh + + align:start position:0% +the teachers are educated themselves uh + + + align:start position:0% +the teachers are educated themselves uh +so yeah they go to they go to college + + align:start position:0% +so yeah they go to they go to college + + + align:start position:0% +so yeah they go to they go to college +so they are they have they they have + + align:start position:0% +so they are they have they they have + + + align:start position:0% +so they are they have they they have +they are well educated + + align:start position:0% +they are well educated + + + align:start position:0% +they are well educated +they don't do much but they are well + + align:start position:0% +they don't do much but they are well + + + align:start position:0% +they don't do much but they are well +educated they are able to do that job + + align:start position:0% +educated they are able to do that job + + + align:start position:0% +educated they are able to do that job +they are there I think it's much it + + align:start position:0% +they are there I think it's much it + + + align:start position:0% +they are there I think it's much it +becomes much more of an issue in + + align:start position:0% +becomes much more of an issue in + + + align:start position:0% +becomes much more of an issue in +secondary school if you remember we + + align:start position:0% +secondary school if you remember we + + + align:start position:0% +secondary school if you remember we +discussed that is that for second High + + align:start position:0% +discussed that is that for second High + + + align:start position:0% +discussed that is that for second High +School you start to have a competition + + align:start position:0% +School you start to have a competition + + + align:start position:0% +School you start to have a competition +between the labor market and and the + + align:start position:0% +between the labor market and and the + + + align:start position:0% +between the labor market and and the +schools + + align:start position:0% +schools + + + align:start position:0% +schools +uh and so the best peop the people who'd + + align:start position:0% +uh and so the best peop the people who'd + + + align:start position:0% +uh and so the best peop the people who'd +be best at teaching are also very good + + align:start position:0% +be best at teaching are also very good + + + align:start position:0% +be best at teaching are also very good +in the rest of the economy so in Middle + + align:start position:0% +in the rest of the economy so in Middle + + + align:start position:0% +in the rest of the economy so in Middle +income growing country like Ghana or + + align:start position:0% +income growing country like Ghana or + + + align:start position:0% +income growing country like Ghana or +India you start feeling that for + + align:start position:0% +India you start feeling that for + + + align:start position:0% +India you start feeling that for +secondary school but in Primary School + + align:start position:0% +secondary school but in Primary School + + + align:start position:0% +secondary school but in Primary School +you have + + align:start position:0% +you have + + + align:start position:0% +you have +a vast supply of people who could do a + + align:start position:0% +a vast supply of people who could do a + + + align:start position:0% +a vast supply of people who could do a +perfectly good job educating kids and + + align:start position:0% +perfectly good job educating kids and + + + align:start position:0% +perfectly good job educating kids and +I'll go back I'll show you why I think + + align:start position:0% +I'll go back I'll show you why I think + + + align:start position:0% +I'll go back I'll show you why I think +they can do their job if they want to in + + align:start position:0% +they can do their job if they want to in + + + align:start position:0% +they can do their job if they want to in +a minute + + align:start position:0% +a minute + + + align:start position:0% +a minute +uh + + align:start position:0% +uh + + + align:start position:0% +uh +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +so how should we think or this would be + + align:start position:0% +so how should we think or this would be + + + align:start position:0% +so how should we think or this would be +like too big of a question for right now + + align:start position:0% +like too big of a question for right now + + + align:start position:0% +like too big of a question for right now +but how should we think about like all + + align:start position:0% +but how should we think about like all + + + align:start position:0% +but how should we think about like all +of this literature about like teacher + + align:start position:0% +of this literature about like teacher + + + align:start position:0% +of this literature about like teacher +incentives and like School quality and + + align:start position:0% +incentives and like School quality and + + + align:start position:0% +incentives and like School quality and +pedagogy or attendance or whatever + + align:start position:0% +pedagogy or attendance or whatever + + + align:start position:0% +pedagogy or attendance or whatever +um comparing the things that happen in + + align:start position:0% +um comparing the things that happen in + + + align:start position:0% +um comparing the things that happen in +the developing World versus I know a lot + + align:start position:0% +the developing World versus I know a lot + + + align:start position:0% +the developing World versus I know a lot +of Education literature exists for the + + align:start position:0% +of Education literature exists for the + + + align:start position:0% +of Education literature exists for the +United States or Europe or other + + align:start position:0% +United States or Europe or other + + + align:start position:0% +United States or Europe or other +subdeveloped countries and so how should + + align:start position:0% +subdeveloped countries and so how should + + + align:start position:0% +subdeveloped countries and so how should +we think about comparing like the + + align:start position:0% +we think about comparing like the + + + align:start position:0% +we think about comparing like the +findings from those two different + + align:start position:0% +findings from those two different + + + align:start position:0% +findings from those two different +literatures it's a great question and uh + + align:start position:0% +literatures it's a great question and uh + + + align:start position:0% +literatures it's a great question and uh +hold the sword I'll go back to it uh I + + align:start position:0% +hold the sword I'll go back to it uh I + + + align:start position:0% +hold the sword I'll go back to it uh I +think like in everything when we are + + align:start position:0% +think like in everything when we are + + + align:start position:0% +think like in everything when we are +wondering how to apply results from one + + align:start position:0% +wondering how to apply results from one + + + align:start position:0% +wondering how to apply results from one +context to another we have to think + + align:start position:0% +context to another we have to think + + + align:start position:0% +context to another we have to think +whether the context changes the model of + + align:start position:0% +whether the context changes the model of + + + align:start position:0% +whether the context changes the model of +what's being delivered in schools and in + + align:start position:0% +what's being delivered in schools and in + + + align:start position:0% +what's being delivered in schools and in +this particular instance I'm pretty sure + + align:start position:0% +this particular instance I'm pretty sure + + + align:start position:0% +this particular instance I'm pretty sure +it does and then I'll tell you exactly + + align:start position:0% +it does and then I'll tell you exactly + + + align:start position:0% +it does and then I'll tell you exactly +how in a moment + + align:start position:0% + + + + align:start position:0% + +we're talking about the teacher side yes + + align:start position:0% +we're talking about the teacher side yes + + + align:start position:0% +we're talking about the teacher side yes +incentive for students themselves are + + align:start position:0% +incentive for students themselves are + + + align:start position:0% +incentive for students themselves are +are effective uh they increase the + + align:start position:0% +are effective uh they increase the + + + align:start position:0% +are effective uh they increase the +increased test scores they increase so + + align:start position:0% +increased test scores they increase so + + + align:start position:0% +increased test scores they increase so +if you give for example Michael cameras + + align:start position:0% +if you give for example Michael cameras + + + align:start position:0% +if you give for example Michael cameras +there is a paper on gold scholarship + + align:start position:0% +there is a paper on gold scholarship + + + align:start position:0% +there is a paper on gold scholarship +that are conditional and performance and + + align:start position:0% +that are conditional and performance and + + + align:start position:0% +that are conditional and performance and +you get an increase in performance + + align:start position:0% +you get an increase in performance + + + align:start position:0% +you get an increase in performance +and + + align:start position:0% +and + + + align:start position:0% +and +um that relates to that that relates to + + align:start position:0% +um that relates to that that relates to + + + align:start position:0% +um that relates to that that relates to +the point I'll + + align:start position:0% +the point I'll + + + align:start position:0% +the point I'll +I'll + + align:start position:0% +I'll + + + align:start position:0% +I'll +again hold it so that's going to become + + align:start position:0% +again hold it so that's going to become + + + align:start position:0% +again hold it so that's going to become +relevant + + align:start position:0% +relevant + + + align:start position:0% +relevant +so let's go back to let's go back to my + + align:start position:0% +so let's go back to let's go back to my + + + align:start position:0% +so let's go back to let's go back to my +private schools so the private school + + align:start position:0% +private schools so the private school + + + align:start position:0% +private schools so the private school +you would think is like the most steeper + + align:start position:0% +you would think is like the most steeper + + + align:start position:0% +you would think is like the most steeper +incentive you could get is to just have + + align:start position:0% +incentive you could get is to just have + + + align:start position:0% +incentive you could get is to just have +to run a private schools which is + + align:start position:0% +to run a private schools which is + + + align:start position:0% +to run a private schools which is +entirely funded by parents and where + + align:start position:0% +entirely funded by parents and where + + + align:start position:0% +entirely funded by parents and where +parents are always willing to walk away + + align:start position:0% +parents are always willing to walk away + + + align:start position:0% +parents are always willing to walk away +so if incentives were powerful then + + align:start position:0% +so if incentives were powerful then + + + align:start position:0% +so if incentives were powerful then +private schools should do much better + + align:start position:0% +private schools should do much better + + + align:start position:0% +private schools should do much better +than public school + + align:start position:0% +than public school + + + align:start position:0% +than public school +make sense and in fact if you compare + + align:start position:0% +make sense and in fact if you compare + + + align:start position:0% +make sense and in fact if you compare +just at the correlations + + align:start position:0% +just at the correlations + + + align:start position:0% +just at the correlations +kids in private school do much better + + align:start position:0% +kids in private school do much better + + + align:start position:0% +kids in private school do much better +than kids in public schools but of + + align:start position:0% +than kids in public schools but of + + + align:start position:0% +than kids in public schools but of +course kids in private schools are + + align:start position:0% +course kids in private schools are + + + align:start position:0% +course kids in private schools are +selected their parents have the money + + align:start position:0% +selected their parents have the money + + + align:start position:0% +selected their parents have the money +and they also are interested enough to + + align:start position:0% +and they also are interested enough to + + + align:start position:0% +and they also are interested enough to +send them to private schools so we can't + + align:start position:0% +send them to private schools so we can't + + + align:start position:0% +send them to private schools so we can't +do that + + align:start position:0% +do that + + + align:start position:0% +do that +so a Karthik + + align:start position:0% +so a Karthik + + + align:start position:0% +so a Karthik +um + + align:start position:0% +um + + + align:start position:0% +um +on an experiment on a private school + + align:start position:0% +on an experiment on a private school + + + align:start position:0% +on an experiment on a private school +attendance + + align:start position:0% +attendance + + + align:start position:0% +attendance +and here I'm going to + + align:start position:0% +and here I'm going to + + + align:start position:0% +and here I'm going to +I'm going to step back step aside one + + align:start position:0% +I'm going to step back step aside one + + + align:start position:0% +I'm going to step back step aside one +point that's going to be my one + + align:start position:0% +point that's going to be my one + + + align:start position:0% +point that's going to be my one +methodological point for the day which + + align:start position:0% +methodological point for the day which + + + align:start position:0% +methodological point for the day which +is he was not just interested in the + + align:start position:0% +is he was not just interested in the + + + align:start position:0% +is he was not just interested in the +impact of private schools on kids who + + align:start position:0% +impact of private schools on kids who + + + align:start position:0% +impact of private schools on kids who +attend private school + + align:start position:0% +attend private school + + + align:start position:0% +attend private school +but he was also interested which for us + + align:start position:0% +but he was also interested which for us + + + align:start position:0% +but he was also interested which for us +for today for the argument for today is + + align:start position:0% +for today for the argument for today is + + + align:start position:0% +for today for the argument for today is +all I need for today but he was also + + align:start position:0% +all I need for today but he was also + + + align:start position:0% +all I need for today but he was also +interested in another question that + + align:start position:0% +interested in another question that + + + align:start position:0% +interested in another question that +people for example in the U.S also in + + align:start position:0% +people for example in the U.S also in + + + align:start position:0% +people for example in the U.S also in +the U.S literature on Charter and + + align:start position:0% +the U.S literature on Charter and + + + align:start position:0% +the U.S literature on Charter and +voucher is continually asked which is + + align:start position:0% +voucher is continually asked which is + + + align:start position:0% +voucher is continually asked which is +what's the impact of having more kids in + + align:start position:0% +what's the impact of having more kids in + + + align:start position:0% +what's the impact of having more kids in +private school on kids that are around + + align:start position:0% +private school on kids that are around + + + align:start position:0% +private school on kids that are around +them either the other kids in private + + align:start position:0% +them either the other kids in private + + + align:start position:0% +them either the other kids in private +school that they are crowding out in + + align:start position:0% +school that they are crowding out in + + + align:start position:0% +school that they are crowding out in +their private school or the kids in + + align:start position:0% +their private school or the kids in + + + align:start position:0% +their private school or the kids in +public school that are left in the + + align:start position:0% +public school that are left in the + + + align:start position:0% +public school that are left in the +public school which might be a good + + align:start position:0% +public school which might be a good + + + align:start position:0% +public school which might be a good +thing because there are fewer kids + + align:start position:0% +thing because there are fewer kids + + + align:start position:0% +thing because there are fewer kids +around to compete with them or bad + + align:start position:0% +around to compete with them or bad + + + align:start position:0% +around to compete with them or bad +things because now they've lost their + + align:start position:0% +things because now they've lost their + + + align:start position:0% +things because now they've lost their +most motivated peers + + align:start position:0% +most motivated peers + + + align:start position:0% +most motivated peers +so this paper was really constructed to + + align:start position:0% +so this paper was really constructed to + + + align:start position:0% +so this paper was really constructed to +answer this question of the equilibrium + + align:start position:0% +answer this question of the equilibrium + + + align:start position:0% +answer this question of the equilibrium +effect of of having markets in private + + align:start position:0% +effect of of having markets in private + + + align:start position:0% +effect of of having markets in private +school in particular the equilibrium + + align:start position:0% +school in particular the equilibrium + + + align:start position:0% +school in particular the equilibrium +effect of a voucher program + + align:start position:0% +effect of a voucher program + + + align:start position:0% +effect of a voucher program +and uh and it's the first paper that did + + align:start position:0% +and uh and it's the first paper that did + + + align:start position:0% +and uh and it's the first paper that did +that I think around the world so what it + + align:start position:0% +that I think around the world so what it + + + align:start position:0% +that I think around the world so what it +did is that is he + + align:start position:0% +did is that is he + + + align:start position:0% +did is that is he +separated he first randomized at two + + align:start position:0% +separated he first randomized at two + + + align:start position:0% +separated he first randomized at two +levels you randomize at the level of the + + align:start position:0% +levels you randomize at the level of the + + + align:start position:0% +levels you randomize at the level of the +village and then you randomize at the + + align:start position:0% +village and then you randomize at the + + + align:start position:0% +village and then you randomize at the +individual level within the village + + align:start position:0% +individual level within the village + + + align:start position:0% +individual level within the village +so and the village is basically think of + + align:start position:0% +so and the village is basically think of + + + align:start position:0% +so and the village is basically think of +a village as a basically a school + + align:start position:0% +a village as a basically a school + + + align:start position:0% +a village as a basically a school +markets + + align:start position:0% +markets + + + align:start position:0% +markets +extended religion of to cover the whole + + align:start position:0% +extended religion of to cover the whole + + + align:start position:0% +extended religion of to cover the whole +school Market + + align:start position:0% +school Market + + + align:start position:0% +school Market +so you have random you have the control + + align:start position:0% +so you have random you have the control + + + align:start position:0% +so you have random you have the control +Villages and you have your treatment + + align:start position:0% +Villages and you have your treatment + + + align:start position:0% +Villages and you have your treatment +villages + + align:start position:0% +villages + + + align:start position:0% +villages +and then the treatment villagers you + + align:start position:0% +and then the treatment villagers you + + + align:start position:0% +and then the treatment villagers you +further have the kids who were in public + + align:start position:0% +further have the kids who were in public + + + align:start position:0% +further have the kids who were in public +school were in principle eligible they + + align:start position:0% +school were in principle eligible they + + + align:start position:0% +school were in principle eligible they +are to apply there was a lottery and + + align:start position:0% +are to apply there was a lottery and + + + align:start position:0% +are to apply there was a lottery and +some of them got it and some of them + + align:start position:0% +some of them got it and some of them + + + align:start position:0% +some of them got it and some of them +didn't get it + + align:start position:0% +didn't get it + + + align:start position:0% +didn't get it +so now we have randomization at two + + align:start position:0% +so now we have randomization at two + + + align:start position:0% +so now we have randomization at two +levels at the level of the market and at + + align:start position:0% +levels at the level of the market and at + + + align:start position:0% +levels at the level of the market and at +the level of the individual so if we + + align:start position:0% +the level of the individual so if we + + + align:start position:0% +the level of the individual so if we +want to know the impact of going to + + align:start position:0% +want to know the impact of going to + + + align:start position:0% +want to know the impact of going to +private school + + align:start position:0% +private school + + + align:start position:0% +private school +in an environment where there are some + + align:start position:0% +in an environment where there are some + + + align:start position:0% +in an environment where there are some +private schools and some vouchers around + + align:start position:0% +private schools and some vouchers around + + + align:start position:0% +private schools and some vouchers around +we can compare these two groups + + align:start position:0% +we can compare these two groups + + + align:start position:0% +we can compare these two groups +if we are interested in the impact of + + align:start position:0% +if we are interested in the impact of + + + align:start position:0% +if we are interested in the impact of +this voucher program on the kids left + + align:start position:0% +this voucher program on the kids left + + + align:start position:0% +this voucher program on the kids left +behind + + align:start position:0% +behind + + + align:start position:0% +behind +who were interested in also doing it we + + align:start position:0% +who were interested in also doing it we + + + align:start position:0% +who were interested in also doing it we +can compare this group to this entire + + align:start position:0% +can compare this group to this entire + + + align:start position:0% +can compare this group to this entire +control group + + align:start position:0% +control group + + + align:start position:0% +control group +so you know this group they're not + + align:start position:0% +so you know this group they're not + + + align:start position:0% +so you know this group they're not +awarded basically the control to the + + align:start position:0% +awarded basically the control to the + + + align:start position:0% +awarded basically the control to the +super control + + align:start position:0% +super control + + + align:start position:0% +super control +if we are interested in the impact on + + align:start position:0% +if we are interested in the impact on + + + align:start position:0% +if we are interested in the impact on +the private school kids who never wanted + + align:start position:0% +the private school kids who never wanted + + + align:start position:0% +the private school kids who never wanted +this in the first place we can compare + + align:start position:0% +this in the first place we can compare + + + align:start position:0% +this in the first place we can compare +them to their counterparts in other in + + align:start position:0% +them to their counterparts in other in + + + align:start position:0% +them to their counterparts in other in +in the control Villages and finally for + + align:start position:0% +in the control Villages and finally for + + + align:start position:0% +in the control Villages and finally for +the public school kids who were not + + align:start position:0% +the public school kids who were not + + + align:start position:0% +the public school kids who were not +interested in the program we can we can + + align:start position:0% +interested in the program we can we can + + + align:start position:0% +interested in the program we can we can +compare them here + + align:start position:0% +compare them here + + + align:start position:0% +compare them here +so that's a design this kind of two-step + + align:start position:0% +so that's a design this kind of two-step + + + align:start position:0% +so that's a design this kind of two-step +randomization to look at equilibrium is + + align:start position:0% +randomization to look at equilibrium is + + + align:start position:0% +randomization to look at equilibrium is +a design that I've also used to uh in in + + align:start position:0% +a design that I've also used to uh in in + + + align:start position:0% +a design that I've also used to uh in in +France to look at the spillover effect + + align:start position:0% +France to look at the spillover effect + + + align:start position:0% +France to look at the spillover effect +of a labor of active labor market policy + + align:start position:0% +of a labor of active labor market policy + + + align:start position:0% +of a labor of active labor market policy +program people are also look to to look + + align:start position:0% +program people are also look to to look + + + align:start position:0% +program people are also look to to look +at effects on you know allowing some + + align:start position:0% +at effects on you know allowing some + + + align:start position:0% +at effects on you know allowing some +people to migrate on other people Etc + + align:start position:0% +people to migrate on other people Etc + + + align:start position:0% +people to migrate on other people Etc +but that's one of the first people that + + align:start position:0% +but that's one of the first people that + + + align:start position:0% +but that's one of the first people that +did it yeah + + align:start position:0% +did it yeah + + + align:start position:0% +did it yeah +if you were to offer + + align:start position:0% +if you were to offer + + + align:start position:0% +if you were to offer +um the launcher later on to the control + + align:start position:0% +um the launcher later on to the control + + + align:start position:0% +um the launcher later on to the control +Court did you do some matching between + + align:start position:0% +Court did you do some matching between + + + align:start position:0% +Court did you do some matching between +the people who later on decided to apply + + align:start position:0% +the people who later on decided to apply + + + align:start position:0% +the people who later on decided to apply +or would you be concerned with something + + align:start position:0% +or would you be concerned with something + + + align:start position:0% +or would you be concerned with something +in that time spent change + + align:start position:0% + + + + align:start position:0% + +so what is the what's the design that + + align:start position:0% +so what is the what's the design that + + + align:start position:0% +so what is the what's the design that +you're proposing instead + + align:start position:0% +you're proposing instead + + + align:start position:0% +you're proposing instead +so I think I would just be concerned + + align:start position:0% +so I think I would just be concerned + + + align:start position:0% +so I think I would just be concerned +about + + align:start position:0% +about + + + align:start position:0% +about +the non-africans + + align:start position:0% +the non-africans + + + align:start position:0% +the non-africans +yeah + + align:start position:0% + + + + align:start position:0% + +uh if we were there to + + align:start position:0% +uh if we were there to + + + align:start position:0% +uh if we were there to +considerably + + align:start position:0% +considerably + + + align:start position:0% +considerably +comparing the treatment you have right + + align:start position:0% +comparing the treatment you have right + + + align:start position:0% +comparing the treatment you have right +now to that controller if you layered + + align:start position:0% +now to that controller if you layered + + + align:start position:0% +now to that controller if you layered +give the voucher to the controller and + + align:start position:0% +give the voucher to the controller and + + + align:start position:0% +give the voucher to the controller and +then you just use the individuals who + + align:start position:0% +then you just use the individuals who + + + align:start position:0% +then you just use the individuals who +chose to apply yeah so you would be + + align:start position:0% +chose to apply yeah so you would be + + + align:start position:0% +chose to apply yeah so you would be +worried that the people who choose to + + align:start position:0% +worried that the people who choose to + + + align:start position:0% +worried that the people who choose to +apply the people who didn't are + + align:start position:0% +apply the people who didn't are + + + align:start position:0% +apply the people who didn't are +different in a way that are difficult to + + align:start position:0% +different in a way that are difficult to + + + align:start position:0% +different in a way that are difficult to +to control so a paper we didn't have + + align:start position:0% +to control so a paper we didn't have + + + align:start position:0% +to control so a paper we didn't have +time to cover but I sometimes cover is + + align:start position:0% +time to cover but I sometimes cover is + + + align:start position:0% +time to cover but I sometimes cover is +the the deworming paper + + align:start position:0% +the the deworming paper + + + align:start position:0% +the the deworming paper +where they were interested they tried to + + align:start position:0% +where they were interested they tried to + + + align:start position:0% +where they were interested they tried to +estimate externalities + + align:start position:0% +estimate externalities + + + align:start position:0% +estimate externalities +without having such a design so you try + + align:start position:0% +without having such a design so you try + + + align:start position:0% +without having such a design so you try +to construct a group of kids that is + + align:start position:0% +to construct a group of kids that is + + + align:start position:0% +to construct a group of kids that is +comparable of a situation where they are + + align:start position:0% +comparable of a situation where they are + + + align:start position:0% +comparable of a situation where they are +they are you know it's not perfect you + + align:start position:0% +they are you know it's not perfect you + + + align:start position:0% +they are you know it's not perfect you +don't have really perfectly comparable + + align:start position:0% +don't have really perfectly comparable + + + align:start position:0% +don't have really perfectly comparable +kids so this design avoids that you + + align:start position:0% +kids so this design avoids that you + + + align:start position:0% +kids so this design avoids that you +don't have to worry about can I make the + + align:start position:0% +don't have to worry about can I make the + + + align:start position:0% +don't have to worry about can I make the +non-applicant similar exposed + + align:start position:0% +non-applicant similar exposed + + + align:start position:0% +non-applicant similar exposed +uh you you basically in your design you + + align:start position:0% +uh you you basically in your design you + + + align:start position:0% +uh you you basically in your design you +would hope that the non-applicant two + + align:start position:0% +would hope that the non-applicant two + + + align:start position:0% +would hope that the non-applicant two +years later are comparable to the + + align:start position:0% +years later are comparable to the + + + align:start position:0% +years later are comparable to the +non-applicant you got you know that this + + align:start position:0% +non-applicant you got you know that this + + + align:start position:0% +non-applicant you got you know that this +one's two years later are comparable to + + align:start position:0% +one's two years later are comparable to + + + align:start position:0% +one's two years later are comparable to +them + + align:start position:0% +them + + + align:start position:0% +them +and then you would look at the + + align:start position:0% +and then you would look at the + + + align:start position:0% +and then you would look at the +externality on them but it's not clear + + align:start position:0% +externality on them but it's not clear + + + align:start position:0% +externality on them but it's not clear +that they are you know it's not clear + + align:start position:0% +that they are you know it's not clear + + + align:start position:0% +that they are you know it's not clear +that you can rely on that so that's why + + align:start position:0% +that you can rely on that so that's why + + + align:start position:0% +that you can rely on that so that's why +that those designs are because it's two + + align:start position:0% +that those designs are because it's two + + + align:start position:0% +that those designs are because it's two +years later who knows + + align:start position:0% +years later who knows + + + align:start position:0% +years later who knows +so that's why it was designs are better + + align:start position:0% +so that's why it was designs are better + + + align:start position:0% +so that's why it was designs are better +to measure your x19 so that was my kind + + align:start position:0% +to measure your x19 so that was my kind + + + align:start position:0% +to measure your x19 so that was my kind +of advertising uh pause + + align:start position:0% +of advertising uh pause + + + align:start position:0% +of advertising uh pause +it's finished it's a great design + + align:start position:0% +it's finished it's a great design + + + align:start position:0% +it's finished it's a great design +but it didn't come to be so useful in + + align:start position:0% +but it didn't come to be so useful in + + + align:start position:0% +but it didn't come to be so useful in +this particular instance because uh + + align:start position:0% +this particular instance because uh + + + align:start position:0% +this particular instance because uh +in fact the impact on the people so here + + align:start position:0% +in fact the impact on the people so here + + + align:start position:0% +in fact the impact on the people so here +now we are comparing + + align:start position:0% +now we are comparing + + + align:start position:0% +now we are comparing +the treated the people offer the voucher + + align:start position:0% +the treated the people offer the voucher + + + align:start position:0% +the treated the people offer the voucher +to people who are not a further voucher + + align:start position:0% + + + + align:start position:0% + +um and there is not much of an impact if + + align:start position:0% +um and there is not much of an impact if + + + align:start position:0% +um and there is not much of an impact if +anything so this is in in Andhra Pradesh + + align:start position:0% +anything so this is in in Andhra Pradesh + + + align:start position:0% +anything so this is in in Andhra Pradesh +the the medium of instruction is Telugu + + align:start position:0% + + + + align:start position:0% + +Public School do not teach English + + align:start position:0% +Public School do not teach English + + + align:start position:0% +Public School do not teach English +and or and they do not teach Hindi + + align:start position:0% +and or and they do not teach Hindi + + + align:start position:0% +and or and they do not teach Hindi +uh or they might teach a tiny bit of + + align:start position:0% +uh or they might teach a tiny bit of + + + align:start position:0% +uh or they might teach a tiny bit of +English but very little + + align:start position:0% +English but very little + + + align:start position:0% +English but very little +so what do we find by year two + + align:start position:0% +so what do we find by year two + + + align:start position:0% +so what do we find by year two +of the program the kids offer a voucher + + align:start position:0% +of the program the kids offer a voucher + + + align:start position:0% +of the program the kids offer a voucher +actually do Works in uh in Telugu + + align:start position:0% +actually do Works in uh in Telugu + + + align:start position:0% +actually do Works in uh in Telugu +although that's not significant but then + + align:start position:0% +although that's not significant but then + + + align:start position:0% +although that's not significant but then +I don't know don't do any better + + align:start position:0% +I don't know don't do any better + + + align:start position:0% +I don't know don't do any better +and standard such that we can rule out + + align:start position:0% +and standard such that we can rule out + + + align:start position:0% +and standard such that we can rule out +even modest positive effect of this + + align:start position:0% +even modest positive effect of this + + + align:start position:0% +even modest positive effect of this +intervention on them + + align:start position:0% +intervention on them + + + align:start position:0% +intervention on them +similarly on math + + align:start position:0% +similarly on math + + + align:start position:0% +similarly on math +they do much better in English + + align:start position:0% +they do much better in English + + + align:start position:0% +they do much better in English +and overall the big fat zero + + align:start position:0% +and overall the big fat zero + + + align:start position:0% +and overall the big fat zero +you can now you know we saw IV last time + + align:start position:0% +you can now you know we saw IV last time + + + align:start position:0% +you can now you know we saw IV last time +so if you if you want you can instrument + + align:start position:0% +so if you if you want you can instrument + + + align:start position:0% +so if you if you want you can instrument +for actually going to school with + + align:start position:0% +for actually going to school with + + + align:start position:0% +for actually going to school with +receiving a voucher + + align:start position:0% +receiving a voucher + + + align:start position:0% +receiving a voucher +um + + align:start position:0% +um + + + align:start position:0% +um +I think this is perfectly decent + + align:start position:0% +I think this is perfectly decent + + + align:start position:0% +I think this is perfectly decent +instrument I would not be too worried + + align:start position:0% +instrument I would not be too worried + + + align:start position:0% +instrument I would not be too worried +about the exclusional attraction but of + + align:start position:0% +about the exclusional attraction but of + + + align:start position:0% +about the exclusional attraction but of +course it's the same thing it's just + + align:start position:0% +course it's the same thing it's just + + + align:start position:0% +course it's the same thing it's just +like a just cosmetic now four years + + align:start position:0% +like a just cosmetic now four years + + + align:start position:0% +like a just cosmetic now four years +later something negative insignificant + + align:start position:0% +later something negative insignificant + + + align:start position:0% +later something negative insignificant +impact on Telugu and on math positive in + + align:start position:0% +impact on Telugu and on math positive in + + + align:start position:0% +impact on Telugu and on math positive in +English now he went and collected a bit + + align:start position:0% +English now he went and collected a bit + + + align:start position:0% +English now he went and collected a bit +more data on other things or + + align:start position:0% + + + + align:start position:0% + +I think that's environmental and science + + align:start position:0% +I think that's environmental and science + + + align:start position:0% +I think that's environmental and science +there is some positive impact + + align:start position:0% +there is some positive impact + + + align:start position:0% +there is some positive impact +insignificant impact there combine a + + align:start position:0% +insignificant impact there combine a + + + align:start position:0% +insignificant impact there combine a +cost-test explaining Hindi and then he + + align:start position:0% +cost-test explaining Hindi and then he + + + align:start position:0% +cost-test explaining Hindi and then he +went and collected Hindi which is not + + align:start position:0% +went and collected Hindi which is not + + + align:start position:0% +went and collected Hindi which is not +taught in a public school and when you + + align:start position:0% +taught in a public school and when you + + + align:start position:0% +taught in a public school and when you +add the Hindi you find a positive effect + + align:start position:0% +add the Hindi you find a positive effect + + + align:start position:0% +add the Hindi you find a positive effect +on the private school + + align:start position:0% +on the private school + + + align:start position:0% +on the private school +not to say he really wanted to have a + + align:start position:0% +not to say he really wanted to have a + + + align:start position:0% +not to say he really wanted to have a +positive headline number but maybe + + align:start position:0% +positive headline number but maybe + + + align:start position:0% +positive headline number but maybe +because this is like this is this is an + + align:start position:0% +because this is like this is this is an + + + align:start position:0% +because this is like this is this is an +effort + + align:start position:0% +effort + + + align:start position:0% +effort +but this is very interesting because + + align:start position:0% +but this is very interesting because + + + align:start position:0% +but this is very interesting because +what we have is that the private school + + align:start position:0% +what we have is that the private school + + + align:start position:0% +what we have is that the private school +are not + + align:start position:0% +are not + + + align:start position:0% +are not +teaching better at what you know they + + align:start position:0% +teaching better at what you know they + + + align:start position:0% +teaching better at what you know they +teach they also teach things that but + + align:start position:0% +teach they also teach things that but + + + align:start position:0% +teach they also teach things that but +they put more effort in different things + + align:start position:0% +they put more effort in different things + + + align:start position:0% +they put more effort in different things +so it's not that they are and presumably + + align:start position:0% +so it's not that they are and presumably + + + align:start position:0% +so it's not that they are and presumably +they are doing that because there is + + align:start position:0% +they are doing that because there is + + + align:start position:0% +they are doing that because there is +Parental demand to um to do it + + align:start position:0% +Parental demand to um to do it + + + align:start position:0% +Parental demand to um to do it +and so that kind of that kind of uh uh + + align:start position:0% +and so that kind of that kind of uh uh + + + align:start position:0% +and so that kind of that kind of uh uh +can is informative for us on what our + + align:start position:0% +can is informative for us on what our + + + align:start position:0% +can is informative for us on what our +parents demanding + + align:start position:0% +parents demanding + + + align:start position:0% +parents demanding +and what balance demanding is not good + + align:start position:0% +and what balance demanding is not good + + + align:start position:0% +and what balance demanding is not good +performance on mathematics and to look + + align:start position:0% +performance on mathematics and to look + + + align:start position:0% +performance on mathematics and to look +what parents are demanding is English + + align:start position:0% +what parents are demanding is English + + + align:start position:0% +what parents are demanding is English +and Hindi + + align:start position:0% +and Hindi + + + align:start position:0% +and Hindi +and um + + align:start position:0% +and um + + + align:start position:0% +and um +there is surprisingly there is no so you + + align:start position:0% +there is surprisingly there is no so you + + + align:start position:0% +there is surprisingly there is no so you +know you can do all your fancy contrast + + align:start position:0% +know you can do all your fancy contrast + + + align:start position:0% +know you can do all your fancy contrast +of spit over it would have been nice + + align:start position:0% +of spit over it would have been nice + + + align:start position:0% +of spit over it would have been nice +since the impact had been positive of + + align:start position:0% +since the impact had been positive of + + + align:start position:0% +since the impact had been positive of +course there is no spillover of + + align:start position:0% +course there is no spillover of + + + align:start position:0% +course there is no spillover of +something that doesn't have a direct + + align:start position:0% +something that doesn't have a direct + + + align:start position:0% +something that doesn't have a direct +impact but it is what it is + + align:start position:0% +impact but it is what it is + + + align:start position:0% +impact but it is what it is +um + + align:start position:0% +um + + + align:start position:0% +um +so yeah + + align:start position:0% + + + + align:start position:0% + +the general rule out even large schools + + align:start position:0% +the general rule out even large schools + + + align:start position:0% +the general rule out even large schools +yeah at the speed of our because the + + align:start position:0% +yeah at the speed of our because the + + + align:start position:0% +yeah at the speed of our because the +main effects are are null + + align:start position:0% +main effects are are null + + + align:start position:0% +main effects are are null +and the speed of our become because the + + align:start position:0% +and the speed of our become because the + + + align:start position:0% +and the speed of our become because the +main effects are are zero the speed over + + align:start position:0% +main effects are are zero the speed over + + + align:start position:0% +main effects are are zero the speed over +become + + align:start position:0% +become + + + align:start position:0% +become +we're harmless people become + + align:start position:0% +we're harmless people become + + + align:start position:0% +we're harmless people become +a sort of uninteresting and and and + + align:start position:0% +a sort of uninteresting and and and + + + align:start position:0% +a sort of uninteresting and and and +uninformative + + align:start position:0% +uninformative + + + align:start position:0% +uninformative +I don't know if you would call them + + align:start position:0% +I don't know if you would call them + + + align:start position:0% +I don't know if you would call them +large + + align:start position:0% +large + + + align:start position:0% +large +this is uh 0.06 so that's you can rule + + align:start position:0% +this is uh 0.06 so that's you can rule + + + align:start position:0% +this is uh 0.06 so that's you can rule +out point 12. + + align:start position:0% +out point 12. + + + align:start position:0% +out point 12. +12 standard deviation if it's like you + + align:start position:0% +12 standard deviation if it's like you + + + align:start position:0% +12 standard deviation if it's like you +can rule out at 95 percent there's + + align:start position:0% +can rule out at 95 percent there's + + + align:start position:0% +can rule out at 95 percent there's +really nothing to write home about + + align:start position:0% +really nothing to write home about + + + align:start position:0% +really nothing to write home about +and negatively again you can rule out + + align:start position:0% +and negatively again you can rule out + + + align:start position:0% +and negatively again you can rule out +minus 0.12 + + align:start position:0% +minus 0.12 + + + align:start position:0% +minus 0.12 +you know if it was a mean if it was a + + align:start position:0% +you know if it was a mean if it was a + + + align:start position:0% +you know if it was a mean if it was a +mean at Point 12 you could say well + + align:start position:0% +mean at Point 12 you could say well + + + align:start position:0% +mean at Point 12 you could say well +there is something there it's not a huge + + align:start position:0% +there is something there it's not a huge + + + align:start position:0% +there is something there it's not a huge +effect that it is an effect but if it's + + align:start position:0% +effect that it is an effect but if it's + + + align:start position:0% +effect that it is an effect but if it's +a 95 percent in confidence interval + + align:start position:0% +a 95 percent in confidence interval + + + align:start position:0% +a 95 percent in confidence interval +that's at Point 12. I wouldn't uh so I + + align:start position:0% +that's at Point 12. I wouldn't uh so I + + + align:start position:0% +that's at Point 12. I wouldn't uh so I +don't seem to stand on there are that + + align:start position:0% +don't seem to stand on there are that + + + align:start position:0% +don't seem to stand on there are that +huge it's just that it's not + + align:start position:0% +huge it's just that it's not + + + align:start position:0% +huge it's just that it's not +there's no direct effect so it would be + + align:start position:0% +there's no direct effect so it would be + + + align:start position:0% +there's no direct effect so it would be +surprising if they were spillover effect + + align:start position:0% +surprising if they were spillover effect + + + align:start position:0% +surprising if they were spillover effect +that's but you know that's bad luck it's + + align:start position:0% +that's but you know that's bad luck it's + + + align:start position:0% +that's but you know that's bad luck it's +I mean it's a bad look it's not bad luck + + align:start position:0% +I mean it's a bad look it's not bad luck + + + align:start position:0% +I mean it's a bad look it's not bad luck +it's interesting anyways but uh the + + align:start position:0% +it's interesting anyways but uh the + + + align:start position:0% +it's interesting anyways but uh the +results would have been more interesting + + align:start position:0% +results would have been more interesting + + + align:start position:0% +results would have been more interesting +in the setup where you have large direct + + align:start position:0% +in the setup where you have large direct + + + align:start position:0% +in the setup where you have large direct +effect which are undone by spillover + + align:start position:0% +effect which are undone by spillover + + + align:start position:0% +effect which are undone by spillover +in our paper on liberal Market policy in + + align:start position:0% +in our paper on liberal Market policy in + + + align:start position:0% +in our paper on liberal Market policy in +France that's what we have we have large + + align:start position:0% +France that's what we have we have large + + + align:start position:0% +France that's what we have we have large +labor of effect when we compare treated + + align:start position:0% +labor of effect when we compare treated + + + align:start position:0% +labor of effect when we compare treated +and control in the same labor market but + + align:start position:0% +and control in the same labor market but + + + align:start position:0% +and control in the same labor market but +it turns out they are all + + align:start position:0% +it turns out they are all + + + align:start position:0% +it turns out they are all +of a distribution within the group + + align:start position:0% +of a distribution within the group + + + align:start position:0% +of a distribution within the group +there is no effect compared to the + + align:start position:0% +there is no effect compared to the + + + align:start position:0% +there is no effect compared to the +control group it's uh + + align:start position:0% +control group it's uh + + + align:start position:0% +control group it's uh +the French French saying for that is a + + align:start position:0% +the French French saying for that is a + + + align:start position:0% +the French French saying for that is a +taking the clothes out of Peter's back + + align:start position:0% +taking the clothes out of Peter's back + + + align:start position:0% +taking the clothes out of Peter's back +to put them on pulls back + + align:start position:0% +to put them on pulls back + + + align:start position:0% +to put them on pulls back +so when + + align:start position:0% +so when + + + align:start position:0% +so when +so it's substantively more more fun but + + align:start position:0% +so it's substantively more more fun but + + + align:start position:0% +so it's substantively more more fun but +the + + align:start position:0% +the + + + align:start position:0% +the +but going back to the result so it's not + + align:start position:0% +but going back to the result so it's not + + + align:start position:0% +but going back to the result so it's not +that the the incentives don't work and + + align:start position:0% +that the the incentives don't work and + + + align:start position:0% +that the the incentives don't work and +that people are not responsive to the + + align:start position:0% +that people are not responsive to the + + + align:start position:0% +that people are not responsive to the +incentives is that they are is that the + + align:start position:0% +incentives is that they are is that the + + + align:start position:0% +incentives is that they are is that the +incentive themselves + + align:start position:0% +incentive themselves + + + align:start position:0% +incentive themselves +that that is the parental preferences + + align:start position:0% +that that is the parental preferences + + + align:start position:0% +that that is the parental preferences +are not going in the direction of + + align:start position:0% +are not going in the direction of + + + align:start position:0% +are not going in the direction of +are not going to uh I'm not targeting + + align:start position:0% +are not going to uh I'm not targeting + + + align:start position:0% +are not going to uh I'm not targeting +the fundamental learning + + align:start position:0% +the fundamental learning + + + align:start position:0% +the fundamental learning +and that's that's a + + align:start position:0% +and that's that's a + + + align:start position:0% +and that's that's a +com that's consistent very much to what + + align:start position:0% +com that's consistent very much to what + + + align:start position:0% +com that's consistent very much to what +we saw in Kenya where people don't see + + align:start position:0% +we saw in Kenya where people don't see + + + align:start position:0% +we saw in Kenya where people don't see +much value in primary education + + align:start position:0% +much value in primary education + + + align:start position:0% +much value in primary education +whatsoever they see value in secondary + + align:start position:0% +whatsoever they see value in secondary + + + align:start position:0% +whatsoever they see value in secondary +education to the extent that it's a + + align:start position:0% +education to the extent that it's a + + + align:start position:0% +education to the extent that it's a +ticket into tertiary education to the ex + + align:start position:0% +ticket into tertiary education to the ex + + + align:start position:0% +ticket into tertiary education to the ex +which is itself a ticket into into the + + align:start position:0% +which is itself a ticket into into the + + + align:start position:0% +which is itself a ticket into into the +rent seeking paying job + + align:start position:0% + + + + align:start position:0% + +feels like emissions rewarded more + + align:start position:0% +feels like emissions rewarded more + + + align:start position:0% +feels like emissions rewarded more +marketing area that matters at least for + + align:start position:0% +marketing area that matters at least for + + + align:start position:0% +marketing area that matters at least for +like Sage yeah so that's not irrational + + align:start position:0% +like Sage yeah so that's not irrational + + + align:start position:0% +like Sage yeah so that's not irrational +I don't I think it's totally irrational + + align:start position:0% +I don't I think it's totally irrational + + + align:start position:0% +I don't I think it's totally irrational +even so English for example makes sense + + align:start position:0% +even so English for example makes sense + + + align:start position:0% +even so English for example makes sense +to have a little bit of English and even + + align:start position:0% +to have a little bit of English and even + + + align:start position:0% +to have a little bit of English and even +if you didn't have English if they cared + + align:start position:0% +if you didn't have English if they cared + + + align:start position:0% +if you didn't have English if they cared +about is uh you know doing great in uh + + align:start position:0% +about is uh you know doing great in uh + + + align:start position:0% +about is uh you know doing great in uh +is uh is uh + + align:start position:0% + + + + align:start position:0% + +sort of and we'll see in a moment it's + + align:start position:0% +sort of and we'll see in a moment it's + + + align:start position:0% +sort of and we'll see in a moment it's +doing at grade level you know being + + align:start position:0% +doing at grade level you know being + + + align:start position:0% +doing at grade level you know being +doing being able to take exams and not + + align:start position:0% +doing being able to take exams and not + + + align:start position:0% +doing being able to take exams and not +like the learning what parents seem to + + align:start position:0% +like the learning what parents seem to + + + align:start position:0% +like the learning what parents seem to +care about is what the what's going to + + align:start position:0% +care about is what the what's going to + + + align:start position:0% +care about is what the what's going to +be useful down the line so a little bit + + align:start position:0% +be useful down the line so a little bit + + + align:start position:0% +be useful down the line so a little bit +of English testing is useful you know we + + align:start position:0% +of English testing is useful you know we + + + align:start position:0% +of English testing is useful you know we +just saw that the math is not that is + + align:start position:0% +just saw that the math is not that is + + + align:start position:0% +just saw that the math is not that is +taught in school is not of any use + + align:start position:0% +taught in school is not of any use + + + align:start position:0% +taught in school is not of any use +anyway so why would they value it so I'm + + align:start position:0% +anyway so why would they value it so I'm + + + align:start position:0% +anyway so why would they value it so I'm +not saying it's irrational but that's + + align:start position:0% +not saying it's irrational but that's + + + align:start position:0% +not saying it's irrational but that's +the the parents are are interested not + + align:start position:0% +the the parents are are interested not + + + align:start position:0% +the the parents are are interested not +in fundamental learning but in what's + + align:start position:0% +in fundamental learning but in what's + + + align:start position:0% +in fundamental learning but in what's +going to be helpful to the kids or to + + align:start position:0% +going to be helpful to the kids or to + + + align:start position:0% +going to be helpful to the kids or to +them + + align:start position:0% +them + + + align:start position:0% +them +so on the one hand there is English and + + align:start position:0% +so on the one hand there is English and + + + align:start position:0% +so on the one hand there is English and +on the other hand there is doing well as + + align:start position:0% +on the other hand there is doing well as + + + align:start position:0% +on the other hand there is doing well as +in passing exams + + align:start position:0% +in passing exams + + + align:start position:0% +in passing exams +and so there on what the parents are + + align:start position:0% +and so there on what the parents are + + + align:start position:0% +and so there on what the parents are +responding to is the structure of the + + align:start position:0% +responding to is the structure of the + + + align:start position:0% +responding to is the structure of the +school system and how it's uh how its uh + + align:start position:0% +school system and how it's uh how its uh + + + align:start position:0% +school system and how it's uh how its uh +organized which is that and that's not + + align:start position:0% +organized which is that and that's not + + + align:start position:0% +organized which is that and that's not +just in India but that's true in most + + align:start position:0% +just in India but that's true in most + + + align:start position:0% +just in India but that's true in most +developing countries in particular all + + align:start position:0% +developing countries in particular all + + + align:start position:0% +developing countries in particular all +the former colonies is a curriculum that + + align:start position:0% +the former colonies is a curriculum that + + + align:start position:0% +the former colonies is a curriculum that +is extraordinarily demanding a much more + + align:start position:0% +is extraordinarily demanding a much more + + + align:start position:0% +is extraordinarily demanding a much more +demanding than our Primary School + + align:start position:0% +demanding than our Primary School + + + align:start position:0% +demanding than our Primary School +curriculum here in the U.S that's kind + + align:start position:0% +curriculum here in the U.S that's kind + + + align:start position:0% +curriculum here in the U.S that's kind +of going back to your question of what's + + align:start position:0% +of going back to your question of what's + + + align:start position:0% +of going back to your question of what's +the difference so this is a snapshot of + + align:start position:0% +the difference so this is a snapshot of + + + align:start position:0% +the difference so this is a snapshot of +grade 4 curriculum in haryana + + align:start position:0% +grade 4 curriculum in haryana + + + align:start position:0% +grade 4 curriculum in haryana +so I hope that you guys are kind of uh + + align:start position:0% +so I hope that you guys are kind of uh + + + align:start position:0% +so I hope that you guys are kind of uh +good about your table of table of + + align:start position:0% +good about your table of table of + + + align:start position:0% +good about your table of table of +multiplication up to 15 because + + align:start position:0% +multiplication up to 15 because + + + align:start position:0% +multiplication up to 15 because +otherwise you cannot if you don't know + + align:start position:0% +otherwise you cannot if you don't know + + + align:start position:0% +otherwise you cannot if you don't know +him like this you cannot do uh you + + align:start position:0% +him like this you cannot do uh you + + + align:start position:0% +him like this you cannot do uh you +cannot pass your you are not at grade + + align:start position:0% +cannot pass your you are not at grade + + + align:start position:0% +cannot pass your you are not at grade +level in grade four in in haryana + + align:start position:0% +level in grade four in in haryana + + + align:start position:0% +level in grade four in in haryana +um so you know by in October they are + + align:start position:0% +um so you know by in October they are + + + align:start position:0% +um so you know by in October they are +recognizing shape by November they are + + align:start position:0% +recognizing shape by November they are + + + align:start position:0% +recognizing shape by November they are +measuring the the area I mean this is + + align:start position:0% +measuring the the area I mean this is + + + align:start position:0% +measuring the the area I mean this is +like + + align:start position:0% +like + + + align:start position:0% +like +a bit crazy + + align:start position:0% +a bit crazy + + + align:start position:0% +a bit crazy +um + + align:start position:0% +um + + + align:start position:0% +um +and the that the problem you're finding + + align:start position:0% +and the that the problem you're finding + + + align:start position:0% +and the that the problem you're finding +in in a lot of former colonies and the + + align:start position:0% +in in a lot of former colonies and the + + + align:start position:0% +in in a lot of former colonies and the +reason is that the the school system was + + align:start position:0% +reason is that the the school system was + + + align:start position:0% +reason is that the the school system was +was created not for educating everyone + + align:start position:0% +was created not for educating everyone + + + align:start position:0% +was created not for educating everyone +to be able to learn + + align:start position:0% +to be able to learn + + + align:start position:0% +to be able to learn +basic you know to read and to write and + + align:start position:0% +basic you know to read and to write and + + + align:start position:0% +basic you know to read and to write and +operate in their life but to educate a + + align:start position:0% +operate in their life but to educate a + + + align:start position:0% +operate in their life but to educate a +minority to become clerks for the + + align:start position:0% +minority to become clerks for the + + + align:start position:0% +minority to become clerks for the +colonial powers and that's what the + + align:start position:0% +colonial powers and that's what the + + + align:start position:0% +colonial powers and that's what the +system was for one at Independence when + + align:start position:0% +system was for one at Independence when + + + align:start position:0% +system was for one at Independence when +it was opened to everyone and scaled up + + align:start position:0% +it was opened to everyone and scaled up + + + align:start position:0% +it was opened to everyone and scaled up +it was open without a change in the + + align:start position:0% +it was open without a change in the + + + align:start position:0% +it was open without a change in the +curriculum + + align:start position:0% +curriculum + + + align:start position:0% +curriculum +partly because it's very difficult to + + align:start position:0% +partly because it's very difficult to + + + align:start position:0% +partly because it's very difficult to +say that oh no we are going to go back + + align:start position:0% +say that oh no we are going to go back + + + align:start position:0% +say that oh no we are going to go back +and and teach you know teach something + + align:start position:0% +and and teach you know teach something + + + align:start position:0% +and and teach you know teach something +simpler because that's that's sort of + + align:start position:0% +simpler because that's that's sort of + + + align:start position:0% +simpler because that's that's sort of +saying your your kids are not a little + + align:start position:0% +saying your your kids are not a little + + + align:start position:0% +saying your your kids are not a little +level of everything so politically it's + + align:start position:0% +level of everything so politically it's + + + align:start position:0% +level of everything so politically it's +very very difficult to say that it was + + align:start position:0% +very very difficult to say that it was + + + align:start position:0% +very very difficult to say that it was +difficult to say it independent it's + + align:start position:0% +difficult to say it independent it's + + + align:start position:0% +difficult to say it independent it's +still difficult to say today that the + + align:start position:0% +still difficult to say today that the + + + align:start position:0% +still difficult to say today that the +curriculum need to be scaled back + + align:start position:0% +curriculum need to be scaled back + + + align:start position:0% +curriculum need to be scaled back +um so you have this curriculum in India + + align:start position:0% +um so you have this curriculum in India + + + align:start position:0% +um so you have this curriculum in India +they passed the right to education in + + align:start position:0% +they passed the right to education in + + + align:start position:0% +they passed the right to education in +2010 saying that every kid has a right + + align:start position:0% +2010 saying that every kid has a right + + + align:start position:0% +2010 saying that every kid has a right +to primary education great + + align:start position:0% +to primary education great + + + align:start position:0% +to primary education great +but part of the right to education law + + align:start position:0% +but part of the right to education law + + + align:start position:0% +but part of the right to education law +was that the teachers have to complete + + align:start position:0% +was that the teachers have to complete + + + align:start position:0% +was that the teachers have to complete +the curriculum no matter what + + align:start position:0% +the curriculum no matter what + + + align:start position:0% +the curriculum no matter what +so they will come you know legally + + align:start position:0% +so they will come you know legally + + + align:start position:0% +so they will come you know legally +liable if they don't complete this crazy + + align:start position:0% +liable if they don't complete this crazy + + + align:start position:0% +liable if they don't complete this crazy +curriculum that almost none of their + + align:start position:0% +curriculum that almost none of their + + + align:start position:0% +curriculum that almost none of their +kids can follow so the result is a + + align:start position:0% +kids can follow so the result is a + + + align:start position:0% +kids can follow so the result is a +system where teachers are teaching to + + align:start position:0% +system where teachers are teaching to + + + align:start position:0% +system where teachers are teaching to +one or two people in a class + + align:start position:0% +one or two people in a class + + + align:start position:0% +one or two people in a class +at the very very top of the classroom + + align:start position:0% +at the very very top of the classroom + + + align:start position:0% +at the very very top of the classroom +which brings me to the U.S system the + + align:start position:0% +which brings me to the U.S system the + + + align:start position:0% +which brings me to the U.S system the +U.S system in primary school is not that + + align:start position:0% +U.S system in primary school is not that + + + align:start position:0% +U.S system in primary school is not that +it's a system of No Child Left Behind + + align:start position:0% +it's a system of No Child Left Behind + + + align:start position:0% +it's a system of No Child Left Behind +whether for good or for bad the Teaching + + align:start position:0% +whether for good or for bad the Teaching + + + align:start position:0% +whether for good or for bad the Teaching +Standards are extremely low + + align:start position:0% +Standards are extremely low + + + align:start position:0% +Standards are extremely low +and you're trying to get everyone to a + + align:start position:0% +and you're trying to get everyone to a + + + align:start position:0% +and you're trying to get everyone to a +minimum core so you might imagine that + + align:start position:0% +minimum core so you might imagine that + + + align:start position:0% +minimum core so you might imagine that +starting from systems that have + + align:start position:0% +starting from systems that have + + + align:start position:0% +starting from systems that have +different objective and different + + align:start position:0% +different objective and different + + + align:start position:0% +different objective and different +philosophy in mind the the effect of + + align:start position:0% +philosophy in mind the the effect of + + + align:start position:0% +philosophy in mind the the effect of +different intervention would also be + + align:start position:0% +different intervention would also be + + + align:start position:0% +different intervention would also be +quite different + + align:start position:0% +quite different + + + align:start position:0% +quite different +uh so that's the kind of the answer to + + align:start position:0% +uh so that's the kind of the answer to + + + align:start position:0% +uh so that's the kind of the answer to +your question + + align:start position:0% +your question + + + align:start position:0% +your question +so what's the possible answer to that is + + align:start position:0% +so what's the possible answer to that is + + + align:start position:0% +so what's the possible answer to that is +uh you know basically teaching is at the + + align:start position:0% +uh you know basically teaching is at the + + + align:start position:0% +uh you know basically teaching is at the +wrong level so you could go back and try + + align:start position:0% +wrong level so you could go back and try + + + align:start position:0% +wrong level so you could go back and try +and teach at the right level + + align:start position:0% +and teach at the right level + + + align:start position:0% +and teach at the right level +uh and so that's the basically the + + align:start position:0% +uh and so that's the basically the + + + align:start position:0% +uh and so that's the basically the +flagship uh the flagship program of the + + align:start position:0% +flagship uh the flagship program of the + + + align:start position:0% +flagship uh the flagship program of the +part-time uh the same people who do the + + align:start position:0% +part-time uh the same people who do the + + + align:start position:0% +part-time uh the same people who do the +answer + + align:start position:0% +answer + + + align:start position:0% +answer +is the stitching at the right level + + align:start position:0% +is the stitching at the right level + + + align:start position:0% +is the stitching at the right level +approach where the uh um basically do + + align:start position:0% +approach where the uh um basically do + + + align:start position:0% +approach where the uh um basically do +regular testing of kids you know every + + align:start position:0% +regular testing of kids you know every + + + align:start position:0% +regular testing of kids you know every +month or so put them in groups by a + + align:start position:0% +month or so put them in groups by a + + + align:start position:0% +month or so put them in groups by a +level of + + align:start position:0% +level of + + + align:start position:0% +level of +by level of of competencies attack these + + align:start position:0% +by level of of competencies attack these + + + align:start position:0% +by level of of competencies attack these +competencies and then move them as they + + align:start position:0% +competencies and then move them as they + + + align:start position:0% +competencies and then move them as they +go along so it turns out that the kid + + align:start position:0% +go along so it turns out that the kid + + + align:start position:0% +go along so it turns out that the kid +who who reached grade four without + + align:start position:0% +who who reached grade four without + + + align:start position:0% +who who reached grade four without +learning to write or read can learn very + + align:start position:0% +learning to write or read can learn very + + + align:start position:0% +learning to write or read can learn very +fast if someone told them then because + + align:start position:0% +fast if someone told them then because + + + align:start position:0% +fast if someone told them then because +they are they are + + align:start position:0% +they are they are + + + align:start position:0% +they are they are +connectively quite ready + + align:start position:0% +connectively quite ready + + + align:start position:0% +connectively quite ready +so a kid can learn to to but if no one + + align:start position:0% +so a kid can learn to to but if no one + + + align:start position:0% +so a kid can learn to to but if no one +is ever teaching them then they won't + + align:start position:0% +is ever teaching them then they won't + + + align:start position:0% +is ever teaching them then they won't +learn so they make uh + + align:start position:0% +learn so they make uh + + + align:start position:0% +learn so they make uh +so this was my so something like that + + align:start position:0% +so this was my so something like that + + + align:start position:0% +so this was my so something like that +the ancestor of this program was the + + align:start position:0% +the ancestor of this program was the + + + align:start position:0% +the ancestor of this program was the +first randomized evolution I was + + align:start position:0% +first randomized evolution I was + + + align:start position:0% +first randomized evolution I was +involved with + + align:start position:0% +involved with + + + align:start position:0% +involved with +uh that was called the balsaki program + + align:start position:0% +uh that was called the balsaki program + + + align:start position:0% +uh that was called the balsaki program +in Baroda and Bombay and since then + + align:start position:0% +in Baroda and Bombay and since then + + + align:start position:0% +in Baroda and Bombay and since then +we've been evaluating some version of + + align:start position:0% +we've been evaluating some version of + + + align:start position:0% +we've been evaluating some version of +this program + + align:start position:0% +this program + + + align:start position:0% +this program +in rural areas in urban areas + + align:start position:0% +in rural areas in urban areas + + + align:start position:0% +in rural areas in urban areas +at some point we were ready to scale up + + align:start position:0% +at some point we were ready to scale up + + + align:start position:0% +at some point we were ready to scale up +a part I'm scaled up in Bihar + + align:start position:0% +a part I'm scaled up in Bihar + + + align:start position:0% +a part I'm scaled up in Bihar +in the context of their scaling up we + + align:start position:0% +in the context of their scaling up we + + + align:start position:0% +in the context of their scaling up we +were able to cover the control group + + align:start position:0% +were able to cover the control group + + + align:start position:0% +were able to cover the control group +so that's the opposite of your standard + + align:start position:0% +so that's the opposite of your standard + + + align:start position:0% +so that's the opposite of your standard +and then uh when you you know you have a + + align:start position:0% +and then uh when you you know you have a + + + align:start position:0% +and then uh when you you know you have a +status quo and then you do a new + + align:start position:0% +status quo and then you do a new + + + align:start position:0% +status quo and then you do a new +intervention It's A Small Piece here the + + align:start position:0% +intervention It's A Small Piece here the + + + align:start position:0% +intervention It's A Small Piece here the +new intervention was in a large place + + align:start position:0% +new intervention was in a large place + + + align:start position:0% +new intervention was in a large place +so you have all of the problems that + + align:start position:0% +so you have all of the problems that + + + align:start position:0% +so you have all of the problems that +will potentially arrive when you do + + align:start position:0% +will potentially arrive when you do + + + align:start position:0% +will potentially arrive when you do +something on large scale + + align:start position:0% +something on large scale + + + align:start position:0% +something on large scale +and we took out the control and it + + align:start position:0% +and we took out the control and it + + + align:start position:0% +and we took out the control and it +didn't work at all and until then we had + + align:start position:0% +didn't work at all and until then we had + + + align:start position:0% +didn't work at all and until then we had +great results and then it didn't work at + + align:start position:0% +great results and then it didn't work at + + + align:start position:0% +great results and then it didn't work at +all so we had to go back to the drawing + + align:start position:0% +all so we had to go back to the drawing + + + align:start position:0% +all so we had to go back to the drawing +boards + + align:start position:0% +boards + + + align:start position:0% +boards +um we try to understand why it wasn't + + align:start position:0% +um we try to understand why it wasn't + + + align:start position:0% +um we try to understand why it wasn't +working and to get a long story shot it + + align:start position:0% +working and to get a long story shot it + + + align:start position:0% +working and to get a long story shot it +wasn't working because the tyranny of + + align:start position:0% +wasn't working because the tyranny of + + + align:start position:0% +wasn't working because the tyranny of +the curriculum was still there so the + + align:start position:0% +the curriculum was still there so the + + + align:start position:0% +the curriculum was still there so the +teacher said I can't Implement your + + align:start position:0% +teacher said I can't Implement your + + + align:start position:0% +teacher said I can't Implement your +program you trained me to implement this + + align:start position:0% +program you trained me to implement this + + + align:start position:0% +program you trained me to implement this +program but I can't because I don't have + + align:start position:0% +program but I can't because I don't have + + + align:start position:0% +program but I can't because I don't have +the time because I have to finish the + + align:start position:0% +the time because I have to finish the + + + align:start position:0% +the time because I have to finish the +curriculum + + align:start position:0% +curriculum + + + align:start position:0% +curriculum +so the program could not catch with + + align:start position:0% +so the program could not catch with + + + align:start position:0% +so the program could not catch with +teacher even though and this goes back + + align:start position:0% +teacher even though and this goes back + + + align:start position:0% +teacher even though and this goes back +to your questions you asked earlier + + align:start position:0% +to your questions you asked earlier + + + align:start position:0% +to your questions you asked earlier +would they be capable of teaching yes + + align:start position:0% +would they be capable of teaching yes + + + align:start position:0% +would they be capable of teaching yes +because if you take the same teacher + + align:start position:0% +because if you take the same teacher + + + align:start position:0% +because if you take the same teacher +during summer + + align:start position:0% +during summer + + + align:start position:0% +during summer +we use the same teacher or partner Bihar + + align:start position:0% +we use the same teacher or partner Bihar + + + align:start position:0% +we use the same teacher or partner Bihar +to the state of BR recruited teacher to + + align:start position:0% +to the state of BR recruited teacher to + + + align:start position:0% +to the state of BR recruited teacher to +teach during summer and we experimented + + align:start position:0% +teach during summer and we experimented + + + align:start position:0% +teach during summer and we experimented +that and their kids during summer + + align:start position:0% +that and their kids during summer + + + align:start position:0% +that and their kids during summer +focusing on basic and TL approach did + + align:start position:0% +focusing on basic and TL approach did + + + align:start position:0% +focusing on basic and TL approach did +great progress so in one summer only + + align:start position:0% +great progress so in one summer only + + + align:start position:0% +great progress so in one summer only +made more progress than in an entire + + align:start position:0% +made more progress than in an entire + + + align:start position:0% +made more progress than in an entire +school year with the same teacher + + align:start position:0% +school year with the same teacher + + + align:start position:0% +school year with the same teacher +because during the summer it was very + + align:start position:0% +because during the summer it was very + + + align:start position:0% +because during the summer it was very +clear what they had to do and it was not + + align:start position:0% +clear what they had to do and it was not + + + align:start position:0% +clear what they had to do and it was not +the curriculum and when you move them + + align:start position:0% +the curriculum and when you move them + + + align:start position:0% +the curriculum and when you move them +back to the normal classroom they think + + align:start position:0% +back to the normal classroom they think + + + align:start position:0% +back to the normal classroom they think +I have to do my curriculum sorry I don't + + align:start position:0% +I have to do my curriculum sorry I don't + + + align:start position:0% +I have to do my curriculum sorry I don't +have time for this teaching and to learn + + align:start position:0% +have time for this teaching and to learn + + + align:start position:0% +have time for this teaching and to learn +to read and write things + + align:start position:0% +to read and write things + + + align:start position:0% +to read and write things +so then what we did is that we + + align:start position:0% +so then what we did is that we + + + align:start position:0% +so then what we did is that we +we went back on part time went back and + + align:start position:0% +we went back on part time went back and + + + align:start position:0% +we went back on part time went back and +thought basically it has to be it + + align:start position:0% +thought basically it has to be it + + + align:start position:0% +thought basically it has to be it +becomes a political economic problem + + align:start position:0% +becomes a political economic problem + + + align:start position:0% +becomes a political economic problem +which is how to uh get it to take hold + + align:start position:0% +which is how to uh get it to take hold + + + align:start position:0% +which is how to uh get it to take hold +in the system + + align:start position:0% +in the system + + + align:start position:0% +in the system +and uh so we saw that we needed the one + + align:start position:0% +and uh so we saw that we needed the one + + + align:start position:0% +and uh so we saw that we needed the one +the teachers needed to know that this is + + align:start position:0% +the teachers needed to know that this is + + + align:start position:0% +the teachers needed to know that this is +the time to do teaching at the right + + align:start position:0% +the time to do teaching at the right + + + align:start position:0% +the time to do teaching at the right +level and you cannot do anything else so + + align:start position:0% +level and you cannot do anything else so + + + align:start position:0% +level and you cannot do anything else so +they basically the government added a an + + align:start position:0% +they basically the government added a an + + + align:start position:0% +they basically the government added a an +hour in the school day + + align:start position:0% +hour in the school day + + + align:start position:0% +hour in the school day +both in treatment and control + + align:start position:0% +both in treatment and control + + + align:start position:0% +both in treatment and control +but in poncola just added an hour and + + align:start position:0% +but in poncola just added an hour and + + + align:start position:0% +but in poncola just added an hour and +treatment that said this hour is for + + align:start position:0% +treatment that said this hour is for + + + align:start position:0% +treatment that said this hour is for +teaching at the right level activity + + align:start position:0% +teaching at the right level activity + + + align:start position:0% +teaching at the right level activity +classes have to be mixed kids have to + + align:start position:0% +classes have to be mixed kids have to + + + align:start position:0% +classes have to be mixed kids have to +learn you know to go back to to do the + + align:start position:0% +learn you know to go back to to do the + + + align:start position:0% +learn you know to go back to to do the +teaching at the right level activities + + align:start position:0% +teaching at the right level activities + + + align:start position:0% +teaching at the right level activities +and they also an old the the school + + align:start position:0% +and they also an old the the school + + + align:start position:0% +and they also an old the the school +inspectors to serve as supervisor at the + + align:start position:0% +inspectors to serve as supervisor at the + + + align:start position:0% +inspectors to serve as supervisor at the +program and that worked nicely + + align:start position:0% +program and that worked nicely + + + align:start position:0% +program and that worked nicely +the other ways to say well forget the + + align:start position:0% +the other ways to say well forget the + + + align:start position:0% +the other ways to say well forget the +teachers let have it implemented by + + align:start position:0% +teachers let have it implemented by + + + align:start position:0% +teachers let have it implemented by +outside by Outsiders that was done in up + + align:start position:0% +outside by Outsiders that was done in up + + + align:start position:0% +outside by Outsiders that was done in up +that's a dysfunctional school system and + + align:start position:0% +that's a dysfunctional school system and + + + align:start position:0% +that's a dysfunctional school system and +that worked that also worked + + align:start position:0% +that worked that also worked + + + align:start position:0% +that worked that also worked +so now uh part-time has been scaled up + + align:start position:0% +so now uh part-time has been scaled up + + + align:start position:0% +so now uh part-time has been scaled up +in India uh the the teaching our right + + align:start position:0% +in India uh the the teaching our right + + + align:start position:0% +in India uh the the teaching our right +level has been scaled up in Africa and + + align:start position:0% +level has been scaled up in Africa and + + + align:start position:0% +level has been scaled up in Africa and +then it's a model that can + + align:start position:0% +then it's a model that can + + + align:start position:0% +then it's a model that can +either of these two models is robust + + align:start position:0% +either of these two models is robust + + + align:start position:0% +either of these two models is robust +enough can be implemented in other + + align:start position:0% +enough can be implemented in other + + + align:start position:0% +enough can be implemented in other +countries and is being implemented in in + + align:start position:0% +countries and is being implemented in in + + + align:start position:0% +countries and is being implemented in in +those places + + align:start position:0% +those places + + + align:start position:0% +those places +so let me conclude uh rapidly + + align:start position:0% +so let me conclude uh rapidly + + + align:start position:0% +so let me conclude uh rapidly +I've given everything I told you you + + align:start position:0% +I've given everything I told you you + + + align:start position:0% +I've given everything I told you you +know how do we go about fixing primary + + align:start position:0% +know how do we go about fixing primary + + + align:start position:0% +know how do we go about fixing primary +education + + align:start position:0% +education + + + align:start position:0% +education +so some people say well give up on the + + align:start position:0% +so some people say well give up on the + + + align:start position:0% +so some people say well give up on the +schools and in fact the founder of + + align:start position:0% +schools and in fact the founder of + + + align:start position:0% +schools and in fact the founder of +part-time madhav chavan that's kind of + + align:start position:0% +part-time madhav chavan that's kind of + + + align:start position:0% +part-time madhav chavan that's kind of +his view now it's like the schools are + + align:start position:0% +his view now it's like the schools are + + + align:start position:0% +his view now it's like the schools are +just a big waste of time + + align:start position:0% +just a big waste of time + + + align:start position:0% +just a big waste of time +and let's give tablets to the kids in in + + align:start position:0% +and let's give tablets to the kids in in + + + align:start position:0% +and let's give tablets to the kids in in +villages and then have them you know + + align:start position:0% +villages and then have them you know + + + align:start position:0% +villages and then have them you know +learn this way to + + align:start position:0% +learn this way to + + + align:start position:0% +learn this way to +material you you push to the tablet + + align:start position:0% +material you you push to the tablet + + + align:start position:0% +material you you push to the tablet +it has potential particularly with with + + align:start position:0% +it has potential particularly with with + + + align:start position:0% +it has potential particularly with with +digital education but it has a big + + align:start position:0% +digital education but it has a big + + + align:start position:0% +digital education but it has a big +problem which is at least the school's + + align:start position:0% +problem which is at least the school's + + + align:start position:0% +problem which is at least the school's +parents have bought in and they're + + align:start position:0% +parents have bought in and they're + + + align:start position:0% +parents have bought in and they're +sending the kids there so the kids are + + align:start position:0% +sending the kids there so the kids are + + + align:start position:0% +sending the kids there so the kids are +captive anything else you have to + + align:start position:0% +captive anything else you have to + + + align:start position:0% +captive anything else you have to +convince the parents that it's worth + + align:start position:0% +convince the parents that it's worth + + + align:start position:0% +convince the parents that it's worth +their while and it's very hard + + align:start position:0% +their while and it's very hard + + + align:start position:0% +their while and it's very hard +convincing the parents it's worth their + + align:start position:0% +convincing the parents it's worth their + + + align:start position:0% +convincing the parents it's worth their +while so Karthik did an experiment where + + align:start position:0% +while so Karthik did an experiment where + + + align:start position:0% +while so Karthik did an experiment where +he found absolutely spectacular effects + + align:start position:0% +he found absolutely spectacular effects + + + align:start position:0% +he found absolutely spectacular effects +of + + align:start position:0% +of + + + align:start position:0% +of +of + + align:start position:0% +of + + + align:start position:0% +of +software-based mathematical intervention + + align:start position:0% +software-based mathematical intervention + + + align:start position:0% +software-based mathematical intervention +intervention on on math and Hindi + + align:start position:0% +intervention on on math and Hindi + + + align:start position:0% +intervention on on math and Hindi +67.67 standard deviation is like great + + align:start position:0% +67.67 standard deviation is like great + + + align:start position:0% +67.67 standard deviation is like great +but the problem is that even though it + + align:start position:0% +but the problem is that even though it + + + align:start position:0% +but the problem is that even though it +was 67 standard deviation + + align:start position:0% +was 67 standard deviation + + + align:start position:0% +was 67 standard deviation +when you ask the questions the type of + + align:start position:0% +when you ask the questions the type of + + + align:start position:0% +when you ask the questions the type of +question that are asked on exams that + + align:start position:0% +question that are asked on exams that + + + align:start position:0% +question that are asked on exams that +are the grade level question there is no + + align:start position:0% +are the grade level question there is no + + + align:start position:0% +are the grade level question there is no +impact on those at least on math that's + + align:start position:0% +impact on those at least on math that's + + + align:start position:0% +impact on those at least on math that's +because the kids are so far behind is + + align:start position:0% +because the kids are so far behind is + + + align:start position:0% +because the kids are so far behind is +that even though they progressed + + align:start position:0% +that even though they progressed + + + align:start position:0% +that even though they progressed +and all of them progressed they still + + align:start position:0% +and all of them progressed they still + + + align:start position:0% +and all of them progressed they still +haven't reached the point where the + + align:start position:0% +haven't reached the point where the + + + align:start position:0% +haven't reached the point where the +questions that are being asked at the + + align:start position:0% +questions that are being asked at the + + + align:start position:0% +questions that are being asked at the +exam are pertinent for them eventually + + align:start position:0% +exam are pertinent for them eventually + + + align:start position:0% +exam are pertinent for them eventually +you would think they they reached them + + align:start position:0% +you would think they they reached them + + + align:start position:0% +you would think they they reached them +and therefore the parents are totally + + align:start position:0% +and therefore the parents are totally + + + align:start position:0% +and therefore the parents are totally +not interested + + align:start position:0% +not interested + + + align:start position:0% +not interested +and what happened to this program + + align:start position:0% +and what happened to this program + + + align:start position:0% +and what happened to this program +is that + + align:start position:0% +is that + + + align:start position:0% +is that +this is a long paragraph but it's likely + + align:start position:0% +this is a long paragraph but it's likely + + + align:start position:0% +this is a long paragraph but it's likely +to say at the very end of this program + + align:start position:0% +to say at the very end of this program + + + align:start position:0% +to say at the very end of this program +that shows this great result is at the + + align:start position:0% +that shows this great result is at the + + + align:start position:0% +that shows this great result is at the +moment the experiment was over the + + align:start position:0% +moment the experiment was over the + + + align:start position:0% +moment the experiment was over the +program was finished because the parents + + align:start position:0% +program was finished because the parents + + + align:start position:0% +program was finished because the parents +refused to spend like the few cents to + + align:start position:0% +refused to spend like the few cents to + + + align:start position:0% +refused to spend like the few cents to +keep it going uh because from there for + + align:start position:0% +keep it going uh because from there for + + + align:start position:0% +keep it going uh because from there for +their point of view it wasn't reaching + + align:start position:0% +their point of view it wasn't reaching + + + align:start position:0% +their point of view it wasn't reaching +it wasn't useful because it wasn't + + align:start position:0% +it wasn't useful because it wasn't + + + align:start position:0% +it wasn't useful because it wasn't +bringing the kids where they wanted them + + align:start position:0% +bringing the kids where they wanted them + + + align:start position:0% +bringing the kids where they wanted them +to be + + align:start position:0% +to be + + + align:start position:0% +to be +so something that's not happening in the + + align:start position:0% +so something that's not happening in the + + + align:start position:0% +so something that's not happening in the +school is hard so I don't think we can + + align:start position:0% +school is hard so I don't think we can + + + align:start position:0% +school is hard so I don't think we can +give up on the schools changing the + + align:start position:0% +give up on the schools changing the + + + align:start position:0% +give up on the schools changing the +curriculum would of course be the Holy + + align:start position:0% +curriculum would of course be the Holy + + + align:start position:0% +curriculum would of course be the Holy +Grail it's a political year + + align:start position:0% +Grail it's a political year + + + align:start position:0% +Grail it's a political year +I've been trying uh you know a good part + + align:start position:0% +I've been trying uh you know a good part + + + align:start position:0% +I've been trying uh you know a good part +of my professional life with very + + align:start position:0% +of my professional life with very + + + align:start position:0% +of my professional life with very +limited success + + align:start position:0% +limited success + + + align:start position:0% +limited success +uh + + align:start position:0% +uh + + + align:start position:0% +uh +and then there is the final possibility + + align:start position:0% +and then there is the final possibility + + + align:start position:0% +and then there is the final possibility +which is what we started to do in uh + + align:start position:0% +which is what we started to do in uh + + + align:start position:0% +which is what we started to do in uh +with Liz which is to work anywhere where + + align:start position:0% +with Liz which is to work anywhere where + + + align:start position:0% +with Liz which is to work anywhere where +it's not yet you know in the margin + + align:start position:0% +it's not yet you know in the margin + + + align:start position:0% +it's not yet you know in the margin +to tutoring programs preschools uh + + align:start position:0% +to tutoring programs preschools uh + + + align:start position:0% +to tutoring programs preschools uh +um the completely different schools like + + align:start position:0% +um the completely different schools like + + + align:start position:0% +um the completely different schools like +they have in uttapadesh where there is + + align:start position:0% +they have in uttapadesh where there is + + + align:start position:0% +they have in uttapadesh where there is +no teaching happening anyway which you + + align:start position:0% +no teaching happening anyway which you + + + align:start position:0% +no teaching happening anyway which you +can sort of take over that kind of + + align:start position:0% +can sort of take over that kind of + + + align:start position:0% +can sort of take over that kind of +things + + align:start position:0% +things + + + align:start position:0% +things +so + + align:start position:0% +so + + + align:start position:0% +so +um I want to let you go so I won't get + + align:start position:0% +um I want to let you go so I won't get + + + align:start position:0% +um I want to let you go so I won't get +into the details of what we did with Liz + + align:start position:0% +into the details of what we did with Liz + + + align:start position:0% +into the details of what we did with Liz +but basically experiment after + + align:start position:0% +but basically experiment after + + + align:start position:0% +but basically experiment after +experiments we've developed an approach + + align:start position:0% +experiments we've developed an approach + + + align:start position:0% +experiments we've developed an approach +to teaching preschool mathematics that + + align:start position:0% +to teaching preschool mathematics that + + + align:start position:0% +to teaching preschool mathematics that +we think is good and can now be scaled + + align:start position:0% +we think is good and can now be scaled + + + align:start position:0% +we think is good and can now be scaled +up so now and more and more kids go to + + align:start position:0% +up so now and more and more kids go to + + + align:start position:0% +up so now and more and more kids go to +preschool so if at least they can you + + align:start position:0% +preschool so if at least they can you + + + align:start position:0% +preschool so if at least they can you +know they can be exposed to our program + + align:start position:0% +know they can be exposed to our program + + + align:start position:0% +know they can be exposed to our program +nobody cares that the simple people seem + + align:start position:0% +nobody cares that the simple people seem + + + align:start position:0% +nobody cares that the simple people seem +to be very happy to let us operate in + + align:start position:0% +to be very happy to let us operate in + + + align:start position:0% +to be very happy to let us operate in +preschools whereas anything like the + + align:start position:0% +preschools whereas anything like the + + + align:start position:0% +preschools whereas anything like the +teaching at the right level in primary + + align:start position:0% +teaching at the right level in primary + + + align:start position:0% +teaching at the right level in primary +school you have to fight with this + + align:start position:0% +school you have to fight with this + + + align:start position:0% +school you have to fight with this +existing existing pressure the one + + align:start position:0% +existing existing pressure the one + + + align:start position:0% +existing existing pressure the one +worries is though is that these are the + + align:start position:0% +worries is though is that these are the + + + align:start position:0% +worries is though is that these are the +detail doesn't matter the one worry is + + align:start position:0% +detail doesn't matter the one worry is + + + align:start position:0% +detail doesn't matter the one worry is +that + + align:start position:0% +that + + + align:start position:0% +that +as this margin expands that's the + + align:start position:0% +as this margin expands that's the + + + align:start position:0% +as this margin expands that's the +trade-off this margin expands more and + + align:start position:0% +trade-off this margin expands more and + + + align:start position:0% +trade-off this margin expands more and +more schools go to primaries to + + align:start position:0% +more schools go to primaries to + + + align:start position:0% +more schools go to primaries to +preschool so that's great this gives us + + align:start position:0% +preschool so that's great this gives us + + + align:start position:0% +preschool so that's great this gives us +more space to do our stuff + + align:start position:0% +more space to do our stuff + + + align:start position:0% +more space to do our stuff +but then as it expands people start + + align:start position:0% +but then as it expands people start + + + align:start position:0% +but then as it expands people start +caring more about it + + align:start position:0% +caring more about it + + + align:start position:0% +caring more about it +so there are calls to regulate the + + align:start position:0% +so there are calls to regulate the + + + align:start position:0% +so there are calls to regulate the +coaching centers and what is being done + + align:start position:0% +coaching centers and what is being done + + + align:start position:0% +coaching centers and what is being done +there and they are called to regulate + + align:start position:0% +there and they are called to regulate + + + align:start position:0% +there and they are called to regulate +the preschool and have a curriculum for + + align:start position:0% +the preschool and have a curriculum for + + + align:start position:0% +the preschool and have a curriculum for +preschool so it's kind of a kind of + + align:start position:0% +preschool so it's kind of a kind of + + + align:start position:0% +preschool so it's kind of a kind of +permanent cat and mouse problem so the + + align:start position:0% +permanent cat and mouse problem so the + + + align:start position:0% +permanent cat and mouse problem so the +bottom line is that basically you need + + align:start position:0% +bottom line is that basically you need + + + align:start position:0% +bottom line is that basically you need +to be pretty patient which is I don't + + align:start position:0% +to be pretty patient which is I don't + + + align:start position:0% +to be pretty patient which is I don't +think there is going to be a silver + + align:start position:0% +think there is going to be a silver + + + align:start position:0% +think there is going to be a silver +bullet even though we Now understand the + + align:start position:0% +bullet even though we Now understand the + + + align:start position:0% +bullet even though we Now understand the +problem well + + align:start position:0% +problem well + + + align:start position:0% +problem well +we can't quite we can't fix it easily + + align:start position:0% +we can't quite we can't fix it easily + + + align:start position:0% +we can't quite we can't fix it easily +all you can do is having these programs + + align:start position:0% +all you can do is having these programs + + + align:start position:0% +all you can do is having these programs +that push a little bit demanding the + + align:start position:0% +that push a little bit demanding the + + + align:start position:0% +that push a little bit demanding the +gains are not enormous but they are + + align:start position:0% +gains are not enormous but they are + + + align:start position:0% +gains are not enormous but they are +there and it's a lot of kids so that's + + align:start position:0% +there and it's a lot of kids so that's + + + align:start position:0% +there and it's a lot of kids so that's +already something and there is not going + + align:start position:0% +already something and there is not going + + + align:start position:0% +already something and there is not going +to be a big uh Evolution where recently + + align:start position:0% +to be a big uh Evolution where recently + + + align:start position:0% +to be a big uh Evolution where recently +are going to make it work so much better + + align:start position:0% +are going to make it work so much better + + + align:start position:0% +are going to make it work so much better +and when I conclude like that if I give + + align:start position:0% +and when I conclude like that if I give + + + align:start position:0% +and when I conclude like that if I give +a similar presentation in India + + align:start position:0% +a similar presentation in India + + + align:start position:0% +a similar presentation in India +people are really upset and they come to + + align:start position:0% +people are really upset and they come to + + + align:start position:0% +people are really upset and they come to +me like a particular the tech people + + align:start position:0% +me like a particular the tech people + + + align:start position:0% +me like a particular the tech people +very well-intentioned they said how can + + align:start position:0% +very well-intentioned they said how can + + + align:start position:0% +very well-intentioned they said how can +you say that we don't have the time we + + align:start position:0% +you say that we don't have the time we + + + align:start position:0% +you say that we don't have the time we +have to + + align:start position:0% +have to + + + align:start position:0% +have to +I think it's better to do that than to + + align:start position:0% +I think it's better to do that than to + + + align:start position:0% +I think it's better to do that than to +do nothing which is the alternative we + + align:start position:0% +do nothing which is the alternative we + + + align:start position:0% +do nothing which is the alternative we +have to act this generation blah blah + + align:start position:0% +have to act this generation blah blah + + + align:start position:0% +have to act this generation blah blah +blah so this is uh that's kind of the + + align:start position:0% +blah so this is uh that's kind of the + + + align:start position:0% +blah so this is uh that's kind of the +unpopular message of the only thing you + + align:start position:0% +unpopular message of the only thing you + + + align:start position:0% +unpopular message of the only thing you +can do is push a little bit the the + + align:start position:0% +can do is push a little bit the the + + + align:start position:0% +can do is push a little bit the the +envelope here and there and you're not + + align:start position:0% +envelope here and there and you're not + + + align:start position:0% +envelope here and there and you're not +going to get a revolution yeah + + align:start position:0% +going to get a revolution yeah + + + align:start position:0% +going to get a revolution yeah +yeah sort of thinking about the + + align:start position:0% +yeah sort of thinking about the + + + align:start position:0% +yeah sort of thinking about the +dialogue between + + align:start position:0% +dialogue between + + + align:start position:0% +dialogue between +the teaching at the red level program + + align:start position:0% +the teaching at the red level program + + + align:start position:0% +the teaching at the red level program +and sort of the literature on tracking + + align:start position:0% +and sort of the literature on tracking + + + align:start position:0% +and sort of the literature on tracking +is there a sense within the teaching of + + align:start position:0% +is there a sense within the teaching of + + + align:start position:0% +is there a sense within the teaching of +the right novel of how much of the + + align:start position:0% +the right novel of how much of the + + + align:start position:0% +the right novel of how much of the +effect of the program is due to like + + align:start position:0% +effect of the program is due to like + + + align:start position:0% +effect of the program is due to like +pure effects of like a new configuration + + align:start position:0% +pure effects of like a new configuration + + + align:start position:0% +pure effects of like a new configuration +of + + align:start position:0% +of + + + align:start position:0% +of +with whom the children are learning + + align:start position:0% +with whom the children are learning + + + align:start position:0% +with whom the children are learning +versus changes to the curriculum itself + + align:start position:0% +versus changes to the curriculum itself + + + align:start position:0% +versus changes to the curriculum itself +to the activities yeah so I think it's a + + align:start position:0% +to the activities yeah so I think it's a + + + align:start position:0% +to the activities yeah so I think it's a +lot to the farmer which is just a lot of + + align:start position:0% +lot to the farmer which is just a lot of + + + align:start position:0% +lot to the farmer which is just a lot of +being with a group of your same + + align:start position:0% +being with a group of your same + + + align:start position:0% +being with a group of your same +like-minded kids and so we have a paper + + align:start position:0% +like-minded kids and so we have a paper + + + align:start position:0% +like-minded kids and so we have a paper +in Kenya with Michael Kramer and + + align:start position:0% +in Kenya with Michael Kramer and + + + align:start position:0% +in Kenya with Michael Kramer and +pascalin where we kind of have both + + align:start position:0% +pascalin where we kind of have both + + + align:start position:0% +pascalin where we kind of have both +because we we track and then we have + + align:start position:0% +because we we track and then we have + + + align:start position:0% +because we we track and then we have +either the regular teacher or young + + align:start position:0% +either the regular teacher or young + + + align:start position:0% +either the regular teacher or young +enthusiastic teacher + + align:start position:0% +enthusiastic teacher + + + align:start position:0% +enthusiastic teacher +and and we do find effect of tracking + + align:start position:0% +and and we do find effect of tracking + + + align:start position:0% +and and we do find effect of tracking +and boosts cases both for the both would + + align:start position:0% +and boosts cases both for the both would + + + align:start position:0% +and boosts cases both for the both would +in the non-track school we have huge + + align:start position:0% +in the non-track school we have huge + + + align:start position:0% +in the non-track school we have huge +effect of the young enthusiastic teacher + + align:start position:0% +effect of the young enthusiastic teacher + + + align:start position:0% +effect of the young enthusiastic teacher +and in a track school we still have an + + align:start position:0% +and in a track school we still have an + + + align:start position:0% +and in a track school we still have an +effect of the young enthusiastic teacher + + align:start position:0% +effect of the young enthusiastic teacher + + + align:start position:0% +effect of the young enthusiastic teacher +but even in the regular school the + + align:start position:0% +but even in the regular school the + + + align:start position:0% +but even in the regular school the +tracking really helps + + align:start position:0% + + + + align:start position:0% + +look at this + + align:start position:0% +look at this + + + align:start position:0% +look at this +education system was structured just to + + align:start position:0% +education system was structured just to + + + align:start position:0% +education system was structured just to +like capture the one currently in + + align:start position:0% +like capture the one currently in + + + align:start position:0% +like capture the one currently in +clinical students + + align:start position:0% +clinical students + + + align:start position:0% +clinical students +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +academic skills now in the building is + + align:start position:0% +academic skills now in the building is + + + align:start position:0% +academic skills now in the building is +interesting fact is that that student + + align:start position:0% +interesting fact is that that student + + + align:start position:0% +interesting fact is that that student +also has a higher probability of living + + align:start position:0% +also has a higher probability of living + + + align:start position:0% +also has a higher probability of living +the country once after going through + + align:start position:0% +the country once after going through + + + align:start position:0% +the country once after going through +that nutrition there is that yes + + align:start position:0% +that nutrition there is that yes + + + align:start position:0% +that nutrition there is that yes +yes no no I think that you're absolutely + + align:start position:0% +yes no no I think that you're absolutely + + + align:start position:0% +yes no no I think that you're absolutely +right which is the the most brilliant of + + align:start position:0% +right which is the the most brilliant of + + + align:start position:0% +right which is the the most brilliant of +the the one kid who manages to you know + + align:start position:0% +the the one kid who manages to you know + + + align:start position:0% +the the one kid who manages to you know +make their way to the school system and + + align:start position:0% +make their way to the school system and + + + align:start position:0% +make their way to the school system and +not being crushed by it and go to + + align:start position:0% +not being crushed by it and go to + + + align:start position:0% +not being crushed by it and go to +universities probably somewhere here + + align:start position:0% +universities probably somewhere here + + + align:start position:0% +universities probably somewhere here +so they are contributing to the world + + align:start position:0% +so they are contributing to the world + + + align:start position:0% +so they are contributing to the world +but not necessarily to + + align:start position:0% + + + + align:start position:0% + +okay great thank you so we'll um uh see + + align:start position:0% +okay great thank you so we'll um uh see + + + align:start position:0% +okay great thank you so we'll um uh see +you next week oh it's a long weekend so + + align:start position:0% +you next week oh it's a long weekend so + + + align:start position:0% +you next week oh it's a long weekend so +we'll see you on Wednesday \ No newline at end of file diff --git a/Gv3fPjWiQhs.txt b/Gv3fPjWiQhs.txt new file mode 100644 index 0000000000000000000000000000000000000000..07861633485d6a7a488e99b9c68c49248a6ac1b1 --- /dev/null +++ b/Gv3fPjWiQhs.txt @@ -0,0 +1,195 @@ +align:start position:0% + +the personal reflective memo is a + + align:start position:0% +the personal reflective memo is a + + + align:start position:0% +the personal reflective memo is a +two-page document that I ask the + + align:start position:0% +two-page document that I ask the + + + align:start position:0% +two-page document that I ask the +students to write at the end of the + + align:start position:0% +students to write at the end of the + + + align:start position:0% +students to write at the end of the +class but before the oral exam so all + + align:start position:0% +class but before the oral exam so all + + + align:start position:0% +class but before the oral exam so all +the lectures we've had all the team + + align:start position:0% +the lectures we've had all the team + + + align:start position:0% +the lectures we've had all the team +assignments and all the material has + + align:start position:0% +assignments and all the material has + + + align:start position:0% +assignments and all the material has +been presented and at this point this + + align:start position:0% +been presented and at this point this + + + align:start position:0% +been presented and at this point this +reflective memo asks the students to + + align:start position:0% +reflective memo asks the students to + + + align:start position:0% +reflective memo asks the students to +think back on the material what really + + align:start position:0% +think back on the material what really + + + align:start position:0% +think back on the material what really +uh was the most important thing they + + align:start position:0% +uh was the most important thing they + + + align:start position:0% +uh was the most important thing they +learned uh what of what they learned in + + align:start position:0% +learned uh what of what they learned in + + + align:start position:0% +learned uh what of what they learned in +the class are they going to build into + + align:start position:0% +the class are they going to build into + + + align:start position:0% +the class are they going to build into +you know their own future projects their + + align:start position:0% +you know their own future projects their + + + align:start position:0% +you know their own future projects their +own careers if they're interested in + + align:start position:0% +own careers if they're interested in + + + align:start position:0% +own careers if they're interested in +systems engineering as a career choice + + align:start position:0% +systems engineering as a career choice + + + align:start position:0% +systems engineering as a career choice +whether it's in research or in Industry + + align:start position:0% +whether it's in research or in Industry + + + align:start position:0% +whether it's in research or in Industry +why is that the case and so they submit + + align:start position:0% +why is that the case and so they submit + + + align:start position:0% +why is that the case and so they submit +this uh one or two days before the oral + + align:start position:0% +this uh one or two days before the oral + + + align:start position:0% +this uh one or two days before the oral +exam and so we have a chance to to read + + align:start position:0% +exam and so we have a chance to to read + + + align:start position:0% +exam and so we have a chance to to read +those reflective memos and usually one + + align:start position:0% +those reflective memos and usually one + + + align:start position:0% +those reflective memos and usually one +of the very first questions in the oral + + align:start position:0% +of the very first questions in the oral + + + align:start position:0% +of the very first questions in the oral +exam is + + align:start position:0% +exam is + + + align:start position:0% +exam is +about some key ideas that they presented + + align:start position:0% +about some key ideas that they presented + + + align:start position:0% +about some key ideas that they presented +in their oral memo so it provides a + + align:start position:0% +in their oral memo so it provides a + + + align:start position:0% +in their oral memo so it provides a +great hook uh into the oral exam \ No newline at end of file diff --git a/H0xGKKpKaRE.txt b/H0xGKKpKaRE.txt new file mode 100644 index 0000000000000000000000000000000000000000..cc0bc21cff4446054ba412e875c29c685b76fe6b --- /dev/null +++ b/H0xGKKpKaRE.txt @@ -0,0 +1,641 @@ +There are many +approaches to building + +a general-purpose computer that +can be easily re-programmed + +for new problems. + +Almost all modern computers are +based on the “stored program” + +computer architecture developed +by John von Neumann in 1945, + +which is now commonly referred +to as the “von Neumann model”. + +The von Neumann model +has three components. + +There’s a central processing +unit (aka the CPU) that + +contains a datapath and control +FSM as described previously. + +The CPU is connected +to a read/write memory + +that holds some number W +of words, each with N bits. + +Nowadays, even small +memories have a billion words + +and the width of each +location is at least 32 bits + +(usually more). + +This memory is often referred to +as “main memory” to distinguish + +it from other memories +in the system. + +You can think of it as an array: +when the CPU wishes to operate + +on values in memory , it sends +the memory an array index, + +which we call the address, and, +after a short delay (currently + +10’s of nanoseconds) the memory +will return the N-bit value + +stored at that address. + +Writes to main memory +follow the same protocol + +except, of course, +the data flows + +in the opposite direction. + +We’ll talk about memory +technologies a couple + +of lectures from now. + +And, finally, there are +input/output devices + +that enable the computer +system to communicate + +with the outside world or +to access data storage that, + +unlike main memory, will +remember values even when + +turned off. + +The key idea is +to use main memory + +to hold the instructions +for the CPU as well as data. + +Both instructions and data are, +of course, just binary data + +stored in main memory. + +Interpreted as an +instruction, a value in memory + +can be thought of as a set of +fields containing one or bits + +encoding information +about the actions + +to be performed by the CPU. + +The opcode field indicates +the operation to be performed + +(e.g., ADD, XOR, COMPARE). + +Subsequent fields specify which +registers supply the source + +operands and the +destination register + +where the result is stored. + +The CPU interprets the +information in the instruction + +fields and performs the +requested operation. + +It would then move on to the +next instruction in memory, + +executing the stored +program step-by-step. + +The goal of this +chapter is to discuss + +the details of what operations +we want the CPU to perform, + +how many registers we +should have, and so on. + +Of course, some values in +memory are not instructions! + +They might be binary +data representing + +numeric values, strings +of characters, and so on. + +The CPU will read these values +into its temporary registers + +when it needs to operate on them +and write newly computed values + +back into memory. + +Mr. Blue is asking a +good question: how do we + +know which words in +memory are instructions + +and which are data? + +After all, they’re +both binary values! + +The answer is that we can’t tell +by looking at the values — it’s + +how they are used by the CPU +that distinguishes instructions + +from data. + +If a value is loaded +into the datapath, + +it’s being used as data. + +If a value is loaded +by the control logic, + +it’s being used an instruction. + +So this is the digital +system we’ll build to perform + +computations. + +We’ll start with a datapath +that contains some number + +of registers to +hold data values. + +We’ll be able to select which +registers will supply operands + +for the arithmetic and +logic unit that will perform + +an operation. + +The ALU produces a result +and other status signals. + +The ALU result can +be written back + +to one of the registers +for later use. + +We’ll provide the datapath with +means to move data to and from + +main memory. + +There will be a +control unit that + +provides the necessary control +signals to the datapath. + +In the example +datapath shown here, + +the control unit would +provide ASEL and BSEL + +to select two register +values as operands + +and DEST to select +the register where + +the ALU result will be written. + +If the datapath had, say, +32 internal registers, + +ASEL, BSEL and DEST +would be 5-bit values, + +each specifying a particular +register number in the range + +0 to 31. + +The control unit also +provides the FN function code + +that controls the operation +performed by the ALU. + +The ALU we designed in +Part 1 of the course + +requires a 6-bit +function code to select + +between a variety of arithmetic, +boolean and shift operations. + +The control unit would load +values from main memory + +to be interpreted +as instructions. + +The control unit +contains a register, + +called the “program counter”, +that keeps track of the address + +in main memory of the next +instruction to be executed. + +The control unit also +contains a (hopefully small) + +amount of logic to translate +the instruction fields + +into the necessary +control signals. + +Note the control unit +receives status signals + +from the datapath that will +enable programs to execute + +different sequences +of instructions + +if, for example, a particular +data value was zero. + +The datapath serves as the +brawn of our digital system + +and is responsible for storing +and manipulating data values. + +The control unit serves as +the brain of our system, + +interpreting the program +stored in main memory + +and generating the necessary +sequence of control + +signals for the datapath. + +Instructions are the +fundamental unit of work. + +They’re fetched by the control +unit and executed one after + +another in the order +they are fetched. + +Each instruction +specifies the operation + +to be performed along +with the registers + +to supply the source operands +and destination register where + +the result will be stored. + +In a von Neumann machine, +instruction execution + +involves the steps shown here: + +the instruction is +loaded from the memory + +location whose address is +specified by the program + +counter. + +When the requested data +is returned by the memory, + +the instruction +fields are converted + +to the appropriate control +signals for the datapath, + +selecting the source operands +from the specified registers, + +directing the ALU to perform +the specified operation, + +and storing the result in the +specified destination register. + +The final step in +executing an instruction + +is updating the +value of the program + +counter to be the address +of the next instruction. + +This execution loop is +performed again and again. + +Modern machines can execute +up more than a billion + +instructions per second! + +The discussion so far +has been a bit abstract. + +Now it’s time to roll up our +sleeves and figure out what + +instructions we want +our system to support. + +The specification of instruction +fields and their meaning + +along with the details +of the datapath design + +are collectively called the +instruction set architecture + +(ISA) of the system. + +The ISA is a detailed functional +specification of the operations + +and storage +mechanisms and serves + +as a contract +between the designers + +of the digital hardware +and the programmers who + +will write the programs. + +Since the programs are stored +in main memory and can hence be + +changed, we’ll +call them software, + +to distinguish them from +the digital logic which, + +once implemented, +doesn’t change. + +It’s the combination of hardware +and software that determine + +the behavior of our system. + +The ISA is a new +layer of abstraction: + +we can write programs +for the system + +without knowing +the implementation + +details of the hardware. + +As hardware +technology improves we + +can build faster systems without +having to change the software. + +You can see here that over +a fifteen year timespan, + +the hardware for executing +the Intel x86 instruction set + +went from executing 300,000 +instructions per second + +to executing 5 billion +instructions per second. + +Same software as before, we’ve +just taken advantage of smaller + +and faster MOSFETs to build +more complex circuits and faster + +execution engines. + +But a word of +caution is in order! + +It’s tempting to make choices +in the ISA that reflect + +the constraints of current +technologies, e.g., + +the number of +internal registers, + +the width of the operands, +or the maximum size of main + +memory. + +But it will be hard to change +the ISA when technology + +improves since there’s a +powerful economic incentive + +to ensure that old software +can run on new machines, + +which means that a particular +ISA can live for decades + +and span many generations +of technology. + +If your ISA is successful, +you’ll have to live with any + +bad choices you made +for a very long time. + +Designing an ISA is hard! + +What are the operations +that should be supported? + +How many internal registers? + +How much main memory? + +Should we design the +instruction encoding + +to minimize program size or to +keep the logic in the control + +unit as simple as possible? + +Looking into our +crystal ball, what + +can we say about the computation +and storage capabilities + +of future technologies? + +We’ll answer these questions by +taking a quantitative approach. + +First we’ll choose a set +of benchmark programs, + +chosen as representative of +the many types of programs we + +expect to run on our system. + +So some of benchmark +programs will + +perform scientific and +engineering computations, + +some will manipulate +large data sets + +or perform database +operations, some + +will require specialized +computations for graphics + +or communications, and so on. + +Happily, after many +decades of computer use, + +several standardized +benchmark suites + +are available for us to use. + +We’ll then implement the +benchmark programs using + +our instruction set and simulate +their execution on our proposed + +datapath. + +We’ll evaluate the results to +measure how well the system + +performs. + +But what do we mean by “well”? + +That’s where it +gets interesting: + +“well” could refer to execution +speed, energy consumption, + +circuit size, system cost, etc. + +If you’re designing +a smart watch, + +you’ll make different choices +than if you’re designing + +a high-performance graphics +card or a data-center server. + +Whatever metric you choose to +evaluate your proposed system, + +there’s an important design +principle we can follow: + +identify the common +operations and focus on them + +as you optimize your design. + +For example, in +general-purpose computing, + +almost all programs +spend a lot of their time + +on simple arithmetic +operations and accessing values + +in main memory. + +So those operations +should be made as fast + +and energy efficient +as possible. + +Now, let’s get to work designing +our own instruction set + +and execution engine, a +system we’ll call the Beta. \ No newline at end of file diff --git a/H44LyNdIi5E.txt b/H44LyNdIi5E.txt new file mode 100644 index 0000000000000000000000000000000000000000..65a66d1d7803896cf381a31687cc076c4e2f709a --- /dev/null +++ b/H44LyNdIi5E.txt @@ -0,0 +1,3012 @@ +The following content is +provided under a Creative + +Commons license. + +Your support will help +MIT OpenCourseWare + +continue to offer high quality +educational resources for free. + +To make a donation or +view additional materials + +from hundreds of MIT courses, +visit MIT OpenCourseWare + +at ocw.mit.edu. + +PROFESSOR: OK. + +Let's start. + +So for several +lectures, we've been + +talking about the +XY model, which + +is a collection of +two component spins, + +for example defined +on a square lattice, + +but it could be any +type of lattice. + +And today we are going +to compare and contrast + +that with the case of a solid. + +More specifically for +simplicity, an isotropic solid. + +And a typical example of +an isotropic solid in two + +dimension is the +triangular lattice. + +So something like this. + +What both of these +systems have in common + +is that there is an underlying +continuous symmetry that + +is broken. + +In the case of the XY +model, at low temperatures + +all of the spins would +be pointing more or less + +in the same direction. + +Potentially with +fluctuations, let's say, go + +around the direction +where they're + +supposed to be +pointing-- being, let's + +say, here in the +vertical-- characterized + +by some kind of an angle. + +Let's call it theta. + +And essentially the uniform +state at 0 temperature + +can be characterized +by any theta. + +And because of the +deformations, it's + +captured through these low +energy Goldstone modes. + +And the probability of +some particular deformation + +will be proportional at low +temperature to the integral, + +let's say, in d +dimensions of gradient, + +the change in theta within +different spins squared. + +Of course, with some +considerations as + +we discussed about topological +defects, et cetera, + +being buried in +this description. + +Now, similarly, away +from 0 temperature + +the atoms of a solid +will fluctuate around + +the position that +corresponds to the minimum. + +And so the actual +picture that you + +would see at any +finite temperature + +would be distorted with respect +to the perfect configuration + +and there would be some kind +of a vector [INAUDIBLE] u + +at each location that would +describe this fluctuation. + +Again, there is no cost in +making a uniform distortion + +theta that is the +same across space. + +And similarly here, +there is no cost + +in uniformly translating things. + +So these would both imply that +this row can [? continue ?] + +[INAUDIBLE] leads +to Goldstone modes. + +And the corresponding +energy cost + +in the case of the +isotropically distorted system + +is typically returned +as an integral involving + +elastic moduli, as we've seen. + +And the traditional +way to write that + +is in this form where +the same reason here + +that it wasn't theta +that was appearing + +but gradient of theta, +because a uniform theta + +does not make any cross. + +These strain fields are related +derivatives of the distortion. + +But now we remember +that this u is a vector + +and this strain field uij it +was one half of the derivative + +of uj in the i direction +derivative of ui + +in the j direction symmetrized. + +Actually, probably better +to write this symmetrically + +as beta h equals +to this quantity. + +And then the typical +type of calculation + +that we did for the +XY model was to go + +in terms of the independent +spin wave modes. + +So we go to Fourier space. + +This becomes an integral +ddq 2 pi to the d. + +The derivative here +gave q squared. + +And then I had something like +the Fourier transformed theta + +squared. + +Now I can also more +clearly represent + +this in the Fourier description. + +I will get something like 1/2 +integral vdq 2 pi to the d. + +And a little bit of work +shows that this form Fourier + +transforms to something +that is proportional to mu. + +Again, it has to be +proportionality to q squared + +because the energy +should go to 0 + +as q goes to 0 for very +long wavelength modes. + +And so we'll have something +like q squared mu tilde of q + +squared. + +This is a vector squared. + +u is a vector. + +q is a vector. + +And there is another component +that gives you mu plus lambda. + +And consistent with +rotational symmetry, + +we can have a term that is +q dotted with u tilde of q, + +the whole thing squared. + +And again, you can +reason that you + +can describe the isotropic +system in terms of just two + +elastic moduli is that the +only rotational invariant + +quantities are q squared, +u squared, and q.u, + +that those are the only terms +that you can [? find. ?] + +Now the next thing. + +Once you know this form, you +can immediately say something + +about the fluctuations. + +So you say that expectation +value of theta tilde q theta + +tilde q prime, if I assume +that this is a Gaussian theory + +and these are the +only fluctuations + +that I'm considering, +the answer is + +going to be 2 pi to the d +delta function q plus q prime. + +And then I will get a +factor of 1 over kq squared. + +The corresponding thing here +is a bit more complicated. + +Because as we said, this +quantity u tilde is a vector. + +And I can look at the +correlation between, say, + +the i-th component of +that vector along mode + +q, the j-th component of +that vector along mu 2 prime + +and ask what this is. + +And again, only the +same values of q + +are coupled together, so we get +the usual formula over here. + +If this term was the only +term in the story, that + +is if we were dealing +with vectors q and u that + +are orthogonal to +each other, then we + +would just get the +1 over q squared. + +And so there is actually +a term that is like that. + +But because of this other +term, there is the possibility + +that q and u are in the same +direction, in which case, + +these two costs +will add up and I + +will get something that +is proportional to 2 + +mu plus lambda. + +And so then I will get 2 +mu plus lambda q squared. + +And here I will have qi qj. + +This becomes q to the 4th. + +Let me make sure that I did +not write this incorrectly. + +Yes, I did write it incorrectly. + +It turns out that there is a +mu plus lambda out here too. + +But essentially there's +just a small complication + +that we get because of the +fact that you have a vector u. + +But overall the +scaling is something + +that goes like 1 over q squared, +which is characteristics + +of Goldstone modes here with +additional vectorial things + +to worry about. + +Let me make sure I +separate these two. + +Now one of the things that +we have been concerned with + +is whether these fluctuations +destroy long range order, so + +for long range order the +information that we would like + +to have is that the +entirety of the system + +is roughly pointing +in the same direction, + +meaning that if I know +that this beam here + +is pointed in the +vertical direction, + +if I go very far away, +it is still more or less + +pointed out-- pointing +in the same direction. + +So for that, we could +look, for example, + +as the degree which +[? with ?] these two spins? + +Yes, question? + +AUDIENCE: [INAUDIBLE] +q squared [INAUDIBLE]? + +PROFESSOR: This is 4. + +Is that what you're +worried about? + +AUDIENCE: Yeah. + +It should be 2, I guess. + +PROFESSOR: No, because I have +two powers of q out front. + +AUDIENCE: Right. + +PROFESSOR: So I +think in the notes + +what I have is that +I have actually + +written things this way. + +I put the factor of mu +q squared out front. + +And then I had this +as qi qj over q. + +And I think-- + +AUDIENCE: [INAUDIBLE] +q squared [INAUDIBLE]? + +PROFESSOR: q squared. + +Let me one more time check to +make sure that that's not-- + +actually there's a minus sign. + +All right. + +AUDIENCE: Wouldn't there +be another factor of mu + +to compensate for +the factoring out? + +PROFESSOR: Yeah. + +So let's check this in +the following fashion. + +So I can look at modes +where u and q are + +perpendicular to each other. + +When u and q are +perpendicular to each other, + +I don't have this there. + +And so then what I should +have is just a cost + +that is 1 over mu q squared. + +OK. + +So let's see if +that comes about. + +What I can do is +let's say imagine + +that I'm looking at a q that is +oriented along the x direction. + +And I look at u's that +are in the y direction. + +And I correlate two +u's in the y direction. + +So I will definitely +get a delta ij here. + +I would have a 1. + +Here I would get a +factor of nothing, + +because this term is absent. + +The q's that I'm +looking at don't + +have any component along the +direction of u that I'm having. + +So this is absent +and I will get a 1 + +over mu q squared, which +is consistent with that. + +Now let's look at the case +where I look at u's that + +are aligned with the vector q. + +Let's say again in +the x direction. + +Then, as far as the +energy is concerned, + +both terms are +present and the cost + +should be 2 mu plus lambda. + +So the answer that I +should ultimately get + +should be 1 over +2 mu plus lambda. + +So let's check. + +So here q squared-- and +cancels with this q squared. + +All of the q's are in the +direction of the indices + +that I'm looking at. + +So that cancels. + +This is 1. + +So I will get 1 minus mu plus +lambda over 2 mu plus lambda. + +So then I will get 2 mu plus +lambda minus mu minus lambda. + +So I will get a mu in +front that cancels this. + +And I will be left with +just the 2 mu plus lambda. + +So we've checked +that this is correct. + +All right. + +So this is a proof, if +you like, by induction. + +You knew that the only +forms that are consistent + +are delta ij and qi +qj over q squared. + +So we can give them two +coefficients, a and b, + +and then adjust a and b so +that these two limits that I + +considered are reproduced. + +So-- OK. + +I didn't have to +resort to my notes + +if I was willing to spend +the corresponding three + +minutes here. + +So going back here, in order +to see the degree of alignment + +of the two spins that we have +over here, what we need to do + +is to do is to look something +like cosine of, say, + +theta at location x +minus theta at location x + +prime, which is non +other than the real part + +of the expectation value of +e to the theta at location + +x minus theta at +location x prime. + +And assuming that everything is +governed by this Gaussian rate, + +the answer is going to obtain +by computing this Gaussian + +as exponential of +minus 1/2 the average + +of theta x minus +theta x prime squared. + +So then my task is +to replace theta x + +and theta x prime in terms of +these theta tilde in Fourier + +space. + +And then this will give +me some expectation + +that involves this average. + +And when I complete +that, eventually I + +need to Fourier transform +1 over q squared. + +And we've seen that the Fourier +transform of the 1 over q + +squared is the +Coulomb interaction. + +And so ultimately this becomes +exponential of minus of 1 + +over k. + +The Coulomb interaction +as a function + +of x minus x prime with +the appropriate cutoff + +included in this expression. + +And then the statement +that we always make + +is that this entity +at large distances, + +the Coulomb interaction saying +three dimension, falls off as 1 + +over separation. + +So in three dimensions, +this at large distances + +goes to a constant 1 +over k is something that + +is proportional to temperature. + +So after doing +enough temperature, + +this entity at large +distances goes to a constant. + +So there is some knowledge +about the correlation + +between these +things that is left. + +Whereas in two +dimensions and below, + +when I go to sufficiently +large distances + +the Coulomb +interaction diverges. + +This whole thing goes to +0 and information is lost. + +So this is the in content +that Goldstone modes + +destroy through long range order +in two dimensions and below. + +Except that we saw +that in two dimensions, + +because the Coulomb interaction +grows logarithmically, + +this correlation +fall off according + +to this description only as +a power law with an exponent + +connected to k. + +And then the discussion +that we had for the XY model + +was that at high +temperatures you + +have exponential decay +in two dimensions. + +At low temperature you +have power law decay. + +Although there is no +true long range order, + +there has to be a +phase transition. + +And we saw that +this transition was + +described by the unbinding +of these topological defects. + +So we would like to state +that something similar to that + +is going on over here. + +The only reason I +went through this + +was to figure out what +the analog of this entity + +should be in the +case of the solid. + +So the analog of our theta is +this vector u, the distortion. + +What should be the analog +of e to the i theta? + +And the things that you should +keep in mind is that theta, + +I can't really tell +it's difference + +between theta and theta plus 2 +pi, theta of 4 pi, et cetera. + +So this e to the i +theta captures that. + +If theta goes to theta +plus a multiple of 2 pi, e + +to the i theta +remains invariant. + +So it's a good +measure of ordering. + +It's better than theta itself. + +So similarly, there's +a better measure + +of deviation from +perfect order here + +for the case of the lattice. + +You say, well, why +should I worry about + +that since I can measure what +u is from the perfect position? + +Well, my answer is +this point here. + +Did it come from +here or from there? + +Should you use for u this +or should you use that? + +You don't know. + +So the u that you have the +to use similar to the theta + +that you're using is +somewhat arbitrary. + +And the arbitrariness of +it is given by unit vectors + +along the original lattice. + +That is, u and any u that +is increased or decreased + +by some lattice vector +of the original lattice + +is the same thing. + +You can't take them apart +in the same sense that theta + +and multiple of 2 pi you cannot. + +So then that suggest that I can +construct some kind of an order + +parameter, I call it row +G, which is like this. + +This e to i something. + +It's e to the iu +but u is a vector. + +And what I do I multiple by a +G, which is an inverse lattice + +vector. + +So G is an inverse +lattice vector. + +And essentially the +inverse lattice vectors + +are defined to have the property +that when you multiply them + +with any of the original lattice +vectors-- which are, let's say, + +parametrized by two +integers, m and n-- + +the answer is going to +be some multiple of 2 pi. + +So you can see that +irrespective of whether I choose + +u as distortion from one lattice +position or any other lattice + +position that +happens to be nearby, + +this measure is going to be +giving you the same face. + +So in the same way as +before for the spins where + +I asked whether spins +at large distances + +are correlated long range, +I can do the same thing here + +and define a long range +correlations for a solid + +by looking at e to the iG dotted +with, let's say, u at position + +x minus u at position x prime. + +And x and x prime are two +points on the lattice. + +And again, the u's that I +have are Gaussian distributed. + +So this I will +complete the square. + +I will have +exponential minus 1/2. + +Well, OK, let me be a little +bit careful with this. + +I have G alpha G +beta over 2 because I + +have two factors of G dot u. + +I will write them using +Einstein's summation convention + +as G alpha times u alpha +component times the u beta + +component. + +So once more what we +can do is to then write + +these u's in terms of +their Fourier vectors. + +So what I will have is +exponential minus G alpha G + +beta over 2. + +I will need to +integrate over q's. + +Because of these +factors, I will get + +something like 2 minus 2 +cosine of qx minus x prime. + +So whenever you go to Fourier +space, you will get e to the iq + +x minus e to the iq x prime. + +Different one for +here with different q + +primes, but when you +take the average, + +q prime is set to +minus q so then you + +get this form as usual. + +And then I will have the average +Fourier transform use, which + +is what I wrote over there. + +I will get a 1 over mu q square +delta i delta alpha beta minus + +q alpha q beta q squared mu +plus lambda over mu plus lambda. + +There is a little +bit of subtlety here. + +So I will do something +this is not quite kosher + +but gives me the right answer. + +Certainly I can take this +G alpha a beta inside here. + +When it multiplies +delta alpha beta, + +I will simply get G squared. + +I really G alpha G alpha. + +Sum over alpha. + +It will give me G squared. + +Here what I will +get is a G dot q + +squared because I will have +two Gq's divided by q squared. + +Ultimately I have to integrate +over all values of q, including + +all angle values. + +So there will be, as far +as the angle is concerned, + +something like a +cosine squared here. + +And the rather +unconventional thing to do + +is to angular +averages that first + +and write this as +G squared over 2. + +Once you do that, +then essentially + +you can see that this structure +just gives you a constant. + +And what you will need to +do is the usual Fourier + +transformation of +1 over q squared. + +So eventually you can +see that the answer + +is going to be proportional +to minus G squared. + +I will get a factor +of 2 mu u from here. + +Once I have written this +as G squared over 2, + +I will get 1 minus +1/2 of this quantity. + +So that becomes 2 +mu plus lambda-- + +or 4 mu plus lambda +minus mu minus lambda. + +So I will get a 3 mu plus lambda +divided by 2 2 mu plus lambda. + +And so there's a +factor of 4 here. + +So that's just the numerics +that goes out front. + +The key to the whole thing will +be the usual integration of 1 + +over q squared. + +Just as we had before, I will +get again the same Coulomb + +interaction as a +function of x minus x + +prime with appropriate +lattice cut-off + +introduced so that +the short distance + +behavior is controlled. + +This whole thing has a name. + +It's called a +Debye-Waller factor. + +Well, almost. + +In 3D. + +And the point is +that if I'm looking + +at this whole thing +in three dimensions, + +at large enough separation +this will go to a constant, + +just as we had before. + +And I will conclude +that this entity, as I + +look at two points that are +very far apart, at least that's + +sufficiently low temperature +and all of my mus and lambdas + +are scaled inversely +with temperature, + +so this whole thing is +proportional to temperature. + +Essentially, you can see +that this information + +at large distance goes +to a finite constant, + +telling me that there's +long range orders preserved. + +Again, when I go +to two dimensions, + +you would say that this, +at large distances, + +grows logarithmically. + +And so the correlations +will fall off, + +but fall of as a power law. + +Now for the case +of a solid, usually + +what you do in order to +probe for the order is + +you shine x-rays and +you see what comes out. + +So essentially, you +will see that there + +will be some scattering. + +And the way that the wave +vector of the light has changed + +is characterized by a vector q. + +And we discussed this already, +that the structure factor + +s of q is going to be related to +expectation value of the phase + +that you get from +the different points. + +So I will get a factor +of e to the i q. + +the location of the different +atoms, let's call them r, of x. + +I have to do a sum over x. + +I have to scatter +from all of the atoms. + +There's some overall form +factor that if I'm not + +really interested, +but this whole thing + +has to be first squished. + +So once I square this, I +will be getting averages + +between pairs of points. + +Because of +translational symmetry + +I can relate to that +sum over pairs of points + +to a center of +mass that typically + +would pick up the number +of points that I have. + +And then the +expectation value of e + +to the something like +sum over all points, e + +to the i q.r r of x +minus r of 0 average. + +This average I can +certainly take out here. + +Yes? + +STUDENT: Sorry. + +Is r what you're +calling u before? + +PROFESSOR: No. + +So r is the actual location of +where the particle is location. + +So r, let's say for a particle +that at zero temperature + +was sitting at lattice +point-- that is, + +let's say, in two dimensions +labeled by m and n-- + +it is shifted by an +amount that is u that I + +would assign to that point. + +So the r's that I put here are +the actual physical position + +of the atom. + +Which is composed +of where it was + +sitting at 0 temperature +plus a little bit more. + +So when I do this, indeed I will +get a sum over all positions. + +This could be a label mn, +whatever, of e to the iq. + +The difference +between the two r's + +would be, first of all, the +difference between these two + +at 0 temperature, which +would be some lattice + +vector of some variety. + +Let's call r 0 of x. + +And that quantity has +[INAUDIBLE] fluctuations. + +The fluctuations go into e to +the iq.u of x minus mu of 0. + +Now if I'm doing this at 0 +temperature or very close to 0 + +temperature where this is either +1 at 0 temperature or not too + +much fluctuating at +high temperatures, + +I will essentially be +adding a lot of e to iqr's. + +These are essentially phases. + +They can be positive, negative, +all over the complex plane. + +And typically you would expect +that for a randomly chosen q, + +the answer from adding all +of these things will be 0. + +So the only time we're +close to 0 temperature, + +you expect this to be +something that is significant. + +Scattering is when q is one of +these inverse lattice vectors. + +So if I was really doing this at +0 temperature, this would be 1. + +And the answer that I +would get is essentially + +I would get these delta +function back peaks + +at the locations that correspond +to the inverse lattice spacing. + +And that's presuming +something that you have seen + +in crystallography or whatever. + +You take a solid and you +scatter light from it + +and you will back points. + +So what I expect +is that when I have + +a q that is roughly close to +G but not necessarily sitting + +exactly at that point, +what I would get + +is a scattering that these +proportional to an integral + +over the entire +lattice of something + +like how far I am away +from the right position. + +And I should really write this +as a sum over lattice points, + +but I can approximate +this by an integral. + +The integral again has the +property that it will give me 0 + +unless q is exactly +sitting at G. + +And then for here, I +evaluate this quantity + +when q is close to +G according to what + +I have calculated up there. + +So I will get +exponential of minus G + +squared-- What do I have? + +Over 4 mu, three mu plus +lambda, 2 mu plus lambda. + +The Coulomb interaction +as a function of x. + +Yes? + +STUDENT: Are you missing +an overall factor of m? + +PROFESSOR: That's why I +wrote the proportionality. + +Because what I'm really +interested is what you see. + +And what you see is how things +are varying as a function of q. + +So I'll tell you +what the answer is. + +So you do the Fourier +transform from this. + +And in d equals to 3, what +you find at 0 temperature, + +as we said, you +will get Bragg spots + +at the locations of +G's that correspond + +to the inverse lattice vectors, +which actually themselves + +form a lattice. + +So this is essentially +the space of q. + +And these are the +different values of G. + +Now what happens is that +the strength of each one + +of these delta functions +is then modulated + +by this factor evaluated +at the corresponding G. + +And since it is +proportional to G squared, + +you find that the spots +that are close to the origin + +are well defined. + +As you go further and further +away, the become very weaker. + +And at some point you +cease to see them. + +So that's the-- the +Debye-Waller factor + +describes how these +things vanish as you + +go further and further away. + +And essentially, you find +that they go and diminish + +as e to the minus G squared. + +But clearly, this kind of +scattering from a crystal + +is very different +from the scattering + +that you expect from +an liquid, which + +is essentially you will have +a bright spot at q close to 0 + +and things that would +symmetrically fall off, + +maybe with a couple +of oscillations + +due to the size of the +particles, at cetera. + +Now what happens in d equals +to 2 is kind of interesting. + +Because in d equals +to 2, I'm doing a two + +dimensional integral, +and this thing + +is growing as a power law. + +So basically what +I end up having + +to deal with is something +like e to the i q minus G x. + +And something that falls off +as a over x to some power + +that I will simply cause eta G. +So related to that combination. + +And when you +integrate this, just + +dimensionally you +can see that it + +is an integral that scales as +x to the power of 2 minus eta. + +x is inverse to q minus G. So +this is going to scale as 1 + +over q minus g to the +power of 2 minus eta. + +So as you go along some +particular direction + +and ask what you see, +you find that will + +see peaks close to the locations +of the lattice vectors. + +So let's say they are equally +spaced along the particular + +axis that I'm picking. + +In three dimension, you would +have been seeing delta function + +at each one of these positions +whose strength is governed + +by this Debye-Waller factor. + +In two dimensions, +you will essentially + +see power laws close +to each one of them. + +But as you go further, the +exponent of the power law + +changes. + +So at some point you even +cease to have a divergence. + +But you can essentially +ignore anything + +like that [? happening. ?] + +So you can see that because +we don't have true long range + +order into two +dimensions because + +of these logarithmic +divergences, + +et cetera, the +traditional picture + +that we have of a solid that +is characterized by Bragg + +scattering and delta +function peaks is modified, + +but still it is +something that looks + +very different from the liquid. + +So we expect that as +we raise temperature + +there is a phase transition +between scattering + +of this form and something +that looks like liquid. + +And you can roughly +guess that essentially it + +is going to be related +with these etas becoming + +larger and larger so that +these divergences disappear. + +But what is the mechanism? + +So let's go back and see what +the mechanism was that we + +discovered for the XY model. + +So we are going to look at +d equals to 2 from now on. + +That discussion so +far was general. + +In d equals to 2, we said that +we have topological defect. + +And the story here was that, +as I have been discussing, + +the angle is +undefined up to 2 pi. + +So it would configuration of +angles that kind of radiate + +away from the origin. + +And the idea was that +if I take a circuit + +and integrate around +this circuit-- + +let's call this the s gradient +of theta-- the answer does not + +need to come back to 0. + +It will be some +multiple of 2 pi . + +Some integer multiple. + +And similarly here, we +said that the value of u + +is undefined up to +a lattice spacing. + +That leads to topological +defects, which + +I find it very difficult to +draw for the triangular lattice, + +so I'll draw it for +the square lattice. + +So at each one of +these positions + +there's a particle sitting. + +And you look out here. + +You have a perfect +square lattice. + +You look out here. + +You have a perfect +square lattice. + +But clearly it is not a +perfect square lattice. + +And the analog of the +circuit that I drew over here + +that encloses a +singlularty-- there's clearly + +some kind of a defect +sitting over here-- + +is that I can start with +some point on the lattice + +and perform what is +called a Burgers Circuit. + +What Burgers Circuit +is is some walk + +that you would take +on a lattice, which + +in a perfect lattice +would bring you back + +to your starting point. + +So for example-- that was +not a good starting point. + +Let me start from here. + +Let's say I take four steps +up-- one, two, three, four. + +I take five steps to the right. + +One, two, three, four, five. + +I reverse my four steps. + +So I go four steps down. + +One, two, three, four. + +I reverse my five steps +and I go five steps left. + +One, two, three, four, five. + +And you see that I did +not end up where I was. + +I ended up here. + +And a failure to +close my circuit + +has to be a lattice vector. + +And this is called d and +it's called a Burgers Vector + +that characterize this defect, +which is called a dislocation. + +So the uncertainty that I have +in assigning a value for u + +because of being on a lattice +or deforming a lattice + +gives rise to these +kinds of ambiguity + +that are similar to +the topological defects + +that you had over here. + +Whereas the defects here were +characterized by an integer, + +the defects here +are characterized + +by a lattice vector. + +And here the simplest things +were, say, plus or minus. + +Clearly here on +the square lattice + +the simplest things are plus b, +minus b along the x direction + +and plus b minus b +along the y direction. + +For example, on the +triangular lattice + +it would be plus minus at +any of the three directions + +that would define the lattice. + +So calculating the distortion +field here was actually + +an easy matter because we said +that the gradient of theta + +was something like 1 over r. + +And so the gradient of +theta, which was 1 over r, + +I could in fact write-- +we saw as vector + +that is orthogonal to the vector +that is going out of the plane. + +So we call that a z hat. + +It was also orthogonal to +the direction of motion + +away from the defect, +which we could characterize + +by looking at the gradient. + +The gradient vector +for this distortion + +is clearly in the +radial direction. + +And the answer that we +had here for one defect + +was ni log of r minus ri. + +And since I'm taking the +gradient it doesn't matter. + +I can't put or not +put the cut off. + +And if I had multiple ones, +I would simply sum over it. + +So this was the contribution +to the distortion + +that came from a collection +of defects such as this. + +Now you can see that essentially +in some continuum sense, + +all I'm doing here is similar. + +I can be taking a big circuit. + +And as I go along +that big circuit, + +I can take a gradient-- +So let's-- yeah. + +The s. + +gradient of the +distortion field. + +Distortion field is, +of course, a vector. + +So it has components that I +can write as the x component + +or the y component. + +So this alpha could be the x +component of the distortion + +or the y component +of the distortion. + +And once I complete the circuit, +here the answer was 2 pi n. + +Here the answer is +a lattice vector, + +which is this Burgers Vector +that could be in any direction + +that you want. + +Now as far as +mathematics is concerned, + +this line and this line for each +component are exactly the same. + +So the solution that I can +write for gradient of u + +I can just copy from +here for each component. + +So I can write that +gradient of the u that + +is due to a collection +of dislocations + +is something like z +hat crossed with curl + +of a sum over all of +the potential locations + +off my defect. + +Rather than n, I have b over 2. + +And it's a vector log of +minus ri over [INAUDIBLE]. + +So if I have a collection +of these dislocations + +at different places on my +lattice-- locations ri, + +strengths, b alpha +which is a vector-- + +then the distortion field +that they would generate + +is given by this. + +It's very just following the +answers that the [INAUDIBLE]. + +So then what we did for the +case of the overall system-- + +in order to find how the +different topological defects + +interact with each +was to calculate + +beta h, which was an integral +of gradient of theta squared. + +Yes? + +STUDENT: So the b alpha, you +have an index i [? also? ?] + +PROFESSOR: b alpha +have index i also. + +Like like the ni have index i. + +So maybe I write +it in this fashion. + +Yeah. + +So this is the cost that +we have to evaluate, + +except that we +have to be somewhat + +careful with the meaning +of this gradient of theta + +in that the gradient +of theta, as we said, + +has a contribution that +is from regular spin + +waves, the Goldstone modes, +that can be deformed back + +to everybody pointing +in the same direction + +without topological defect. + +Plus a contribution due to this +topological defect that are + +categorized in that case by ni. + +Now similarly here for +the case of the solid, + +we have the beta h. + +Slightly more complicated +integral d 2x. + +We have mu uij uij plus +lambda over 2 uii ujj. + +And what we can do is to +say that our strain field + +uij has a component that +is like the Goldstone modes + +that we have been +calculating so far, + +essentially treating +everything as Gaussians. + +Except that I will +write it as phi ij. + +And then a part that would come +from the distortion field u + +bar that I calculated. + +So I take that distortion field +and then take derivatives of it + +to symmetrize +appropriately to construct + +the strain that sums from them. + +So we substituted +this form over here. + +And we found that beta h that we +got had a part that was simply + +relate to the Goldstone modes. + +This was the part that could +be treating as a Gaussian. + +And then we had a +part that corresponded + +to the interactions +among these defects. + +And that part we saw +had the character + +of charges ni and +nj plus minus 1 + +characterizing these +topological defects + +having a Coulomb interaction +[? between them ?]. + +And then, of course, +this i less than j, + +we had to worry about what +was happening when i was j. + +And that we considered +to be the contributions + +of the core energy that, +once exponentiated, + +we described as y. + +So it's beta h which is log +of that would be log of y. + +And actually this k bar, by +the way, was simply 2 pi k. + +And it was 2 pi k because each +one of these charges is 2 pi n. + +So there's 2 pi 2 pi. + +But the Coulomb +interaction really + +should be log divided by 2 pi. + +And so k bar becomes +2 pi k times this. + +So I can do the same +thing over here. + +And what I find happens is +that my beta h gets decomposed + +as follows. + +There will be a part that is +simply the original expression + +now for the field +that is well behaved + +and has no dislocation piece. + +And then you +wouldn't be surprised + +because this structure +is no different + +from the other structure. + +There's essentially a +gradient of this distortion + +field squared. + +And you can see that if I +take a second derivative + +of this distortion field or one +derivative of this, effectively + +I will have two +derivatives of a log, which + +will give me a delta function. + +So essentially these +things do behave + +like what you would get from +Coulomb type of potential. + +[INAUDIBLE] plus [INAUDIBLE] +if the potential is 0. + +So not surprisingly, I +we get a minus k bar sum + +over pairs of where these +dislocations are located. + +And then I will have b at +location i, b at location j. + +And then I would have a log of +ri minus rj with some cut off. + +Except that these b's +are actually vector. + +So this term is a dot +product of the two b's. + +And it turns out that when +you go through the algebra, + +there is another +term, which is bi. + +ri minus rj, bj dotted +with ri minus rj + +divided by ri minus rj squared. + +So the charges that we +had in our original theory + +were scalar quantities. + +These defects were characterized +by a scalar value of n. + +And they were interacting +with something + +that was like the ordinary +Coulomb potential. + +Whereas now we are +looking at a system + +that is characterized by +charges that are vectors. + +And it turns out that +what we have here + +is the vectorial analog +of the Coulomb potential. + +And again, if you think about +an isotropic system and vectors, + +this is a vector +that you can form, + +but b.r is another +vector that you can form. + +And so both of them do appear. + +And once you go through +the whole algebra + +and through the inverse +Fourier transform, et cetera, + +you get this +additional contribution + +to this vector +Coulomb interaction. + +That's really is +the only difference. + +And of course, +you will again get + +a sum over all locations +of the core energies + +for creating these defects. + +And the value of k bar here +is related to these parameters + +by mu mu plus lambda divided +by pi 2u plus lambda. + +So this combination +controls what you have. + +So the next thing +that we did was + +to construct a perturbation. + +We essentially said that if +I have these pairs of charges + +that can spontaneously +appear at an energy + +cost but an entropy gain, +they will effectively weaken + +the overall Coulomb potential. + +For example, if I +have to test charges + +then there will be +some polarization + +of the medium, +some reorientation + +of these charges that +appear, that weakens + +the effective charge here. + +And we could +perturbatively calculate + +what the correction +was, except that we + +found that that +correction, which + +involves an integration over +the separation of these things. + +There was an integration +that was potentially + +divergent for us no matter +how small we made the core + +energies here. + +And so what we did was +eventually to construct an RG. + +And the RG was that the +value of this parameter k + +bar-- actually more +usefully its inverse that + +is related to +temperature-- changed + +as a function of integrating +out short distance + +degrees of freedom. + +It was something like 4 pi-- +I think it was 4 pi cubed, + +it doesn't matter-- y squared. + +And that the scaling +of to core energy + +itself was determined +by 2 minus pi k, + +which in terms of this k +bar becomes 2 minus k bar + +over 2 times y. + +And we can do exactly +the same thing over here, + +except for the +complication of having + +to deal with the charges +that are vectorial. + +And you get that the strength +of the Coulomb interaction, + +it's inverse that is +related temperature + +gets re-normalized by +exactly the same process. + +That is, there will be +charges that will appear. + +All the mathematics you +can see is clearly similar. + +And there will be a +reduction, which then you + +can think of as an increase +in temperature, which will + +be proportional to y squared. + +I don't know what the constant +of proportionality is. + +And that dy by dl-- +so essentially I + +focus on the simplest +type of dislocations + +that I would have +of unit spacing-- + +has exactly the +same [INAUDIBLE], + +2 minus k bar over 2 y. + +It turns out that there +is actually a difference. + +And the difference +is as follows. + +That while we did not +calculate the next correction + +in this series, I said +that this correction came + +from essentially what +would a single dipole do, + +which would be some contribution +that is order of y squared. + +And I expect that there +will be correction + +if I look at a configuration +that has pairs of dipoles. + +And this will change +this by order of y + +to the fourth and this +by order of y cubed. + +Whereas if I look at something +like a triangular lattice, + +you can see that if I have +two dislocations out there + +as test dislocations +pointing out + +in opposite +directions, which would + +have some kind of a +interaction such as this. + +And I ask how that +interaction is + +modified by the presence +of dipoles of dislocation + +in the medium. + +I could put a pair +of dislocations + +integrate over the +separation between them. + +I will get, essentially, +the same type + +of mathematical structure that +would ultimately give me this. + +But then the next order +term in this series + +is not for +dislocations because I + +can have a neutral configuration +of three dislocations, + +such as this. + +And so once you +do that, you will + +find that the next +correction here + +is order of y cubed and +order of y squared here. + +But generically, both of +them have a phase diagram + +for RG flows that involves +the inverse of the interaction + +of these charges. + +That is a +temperature-like quantity. + +And there is a critical value +of that inverse, which is 1/4. + +And what happens is that-- +let's see, this other axis is y. + +Anything smaller than +1/4 y tends to go to 0. + +Anything larger, y +tends to get larger. + +And there is going to be +some kind of a separatrix + +that he describes the transition +between flows that go down here + +and the flows that go away. + +And presumably, as I heat up my +original system-- my lattice, + +different types of lattices-- +at low temperature, + +I can figure out what this +combination of mu an lambda is. + +That gives me some value of k. + +And there is some kind of the +core energy for the vertices + +that I can calculate. + +So there will be some point +in this phase diagram, which + +at low enough temperature I will +go over here, which corresponds + +to a system that has an +effective logarithmic + +interaction between +dislocations. + +As I change the temperature, +I will proceed around + +some trajectory such as this +because everything will change. + +And presumably, at some +point I will intersect this + +and I will go to +the other phase. + +Now the characteristic +of the other phase + +was that this parameter +k was going to 0. + +It was essentially the +logarithmic interaction + +was disappeared. + +And you can see that that +parameter k going to 0 + +means that mu, the shear +modulus, has to go to 0. + +So basically this phase out +here is definitely characterized + +by 0 shear modulus. + +So again, the two +parameters mu and lambda, mu + +is the one that +gives you the cost + +of trying to shear in a system. + +And essentially the presence +of the resistance to shear + +is what defines a solid for you. + +So this is a solid to something +that does not have rigidity + +transition. + +It turns out that there +is one subtlety here. + +I don't know whether it's +good to mention or not. + +But so in the case of alpha +this superfluidity, for example, + +we said that this +coupling strength as you + +approach the transition +rose to a universal value. + +In these units it will be 4. + +But that it approaches +that universal value + +with a logarithmic singularity. + +Sorry, with a square +root singularly. + +Sorry. + +And we saw that this was +experimentally observed + +in films of superfluid film. + +I also said that +on the other side + +you have a finite correlations. + +The correlations will be +decaying exponentially. + +And this correlation length has +this very unusual signature, + +which is that it diverged as +a square root of t minus tc + +in the exponent. + +It was giving rise to these +essentially singularities. + +While everything kind of looks +identical between this RG + +and the other RG, it +turns out that once you + +keep track of these corrections, +these corrections actually + +are important. + +And for the vectorial +version of the Coulomb gas, + +you find that they shear modulus +that is finite in this phase + +reaches its final +value, which is not + +universal because the +thing that the universal is + +that combination that +involves both mu and lambda. + +But rather than stc +minus t to the 1/2, + +stc minus t to +some exponent that + +is called mu bar, which +is 0.36963 [INAUDIBLE]. + +So this is a kind +of subtle thing + +that is buried in these +recursion relationships + +once you go to a higher order. + +And accompanying that is +a correlation length that + +also diverges with some behavior +dominated by the same exponent. + +So once people understood +the original [? Koster ?] + +[INAUDIBLE] +transition, it was kind + +of a very natural +next step for them + +to think about these +locations in a two dimensional + +solid and say that +in the same manner + +that the unbinding +of these defects + +got rid of the residual +long range order that + +was left in the XY model. + +That this kind of +ordering that we said + +exists for the two +dimensional solid, + +this appears as a result of +unbinding of dislocations + +and you get a liquid. + +Turns out that +that's not correct. + +And it was pointed +out by Bert Halperin + +I think that if you +look at a solid, + +there's two things that you. + +You have the +translational order, + +but there's also +orientational order. + +That is, you can +look, for example, + +at a collection of +spins here and the bonds + +are pointing along +the x and y directions + +and you can look down here +and the bonds are pointing + +in the x and y directions. + +And from the picture +that I drew over here, + +you can kind of see that once +I insert this dislocation which + +corresponds to an +additional line, + +the positions here +are distorted. + +Once I have many +of these inserted, + +it is kind of +obvious that I will + +lose any idea of how the +position of this lattice point + +and something out +there is related. + +It's not so obvious +that inserting + +lots and lots of +these lines will + +remove the knowledge +that I have about + +the orientation of the bonds. + +And the insight that +we will follow up-- + +and maybe it's probably a +good idea to do it next time-- + +is that actually once +the dislocations unbind, + +we will lose this +kind of ordering. + +If I do this in two +dimensions, these + +are power law decays +at low temperatures. + +Once the dislocations +unbind, this + +becomes an exponential +decay, as I would expect. + +But I can also define locally +some kind of an orientation. + +Let's again call it theta. + +But theta is, let's say, the +orientation of the bond that + +connects two neighboring spins. + +Now what I can do is to look at +the correlation of orientations + +at different positions. + +And it turns out that +if I'm doing something + +like a triangular lattice, +I can't just pick the angle + +and correlate the angle from +one point to another point + +because let's say on the square +lattice the angle itself, + +I don't know whether +it was coming + +from a bond that was +originally in the x direction + +or in the y direction. + +So this is unknown up to +a factor of 90 degrees. + +In the triangular lattice +it is an unknown up + +to a factor of 60 degrees. + +So what I should do is I should +define e to the 6 i theta + +at each location as a measure +of the orientational order. + +You can see that, again, +if I'm at 0 temperature, + +I can reorient the lattice +any way that I like. + +This phase would be the same +across the entire system. + +So what I'm interested +is to find out + +what is the expectation +value of this object when + +I look at points that +are further apart. + +And again, clearly if +I'm at 0 temperature + +these thetas are the same. + +This will go to 1 at +finite temperature. + +Because of the fluctuations +it will start to move a bit. + +And what we can show-- and +you will do it next time-- + +is that as long as you are +in the 0 temperature phase + +you will find that this +goes to a constant, + +even in two dimensions. + +But once the dislocations +unbind, what we will show + +is that it doesn't +decay exponentially, + +but then it starts to decay +as 1 over x to some power, + +let's call it eta theta. + +And then at some +higher temperatures, + +it eventually starts +to decay exponentially. + +So there is the +original solid in two + +dimension that we started +that has true long range + +order in the orientations. + +And that is reflected +in these Fourier + +transforms that we make. + +So we said that when we do +the Fourier transform and look + +at the x-ray scattering, +let's say from a two + +dimensional crystal, you were +seeing these kinds of pictures. + +And then these were +becoming weaker + +as we went further +and further out. + +But now you can see that +this picture clearly + +has a very, very defined +orientational aspect to it. + +Now once we go to this +intermediate phase, + +all of these peaks disappear. + +But what you find is that +when you look at this, rather + +than getting a ring +that is uniform, + +you will a see a ring that has +very well- defined variation. + +One, two, three, +four, five, six. + +Six-fold symmetry to it. + +So this phase has no +knowledge of where + +the particles are located, +but knows the orientations. + +It's a kind of a liquid crystal. + +It actually has a name. + +It's called hexatic. + +But it's one of the family of +different types of materials + +that have no translational +order but some kind + +of orientational order +that are hexatics. + +So the transition between +this hexatic phase + +to this fully disordered phase, +it turns out in two dimension + +to be another one of +these dislocation-- + +well, topology defect +unbinding transition. + +So maybe we will finish +with that next time around. \ No newline at end of file diff --git a/HZFIdpThd-s.txt b/HZFIdpThd-s.txt new file mode 100644 index 0000000000000000000000000000000000000000..7ad1407d6e37f1b5a2db109a57f7ba256e04d428 --- /dev/null +++ b/HZFIdpThd-s.txt @@ -0,0 +1,1523 @@ +align:start position:0% + +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +many chemistry and biochemistry + + align:start position:0% +many chemistry and biochemistry + + + align:start position:0% +many chemistry and biochemistry +procedures will require you to perform a + + align:start position:0% +procedures will require you to perform a + + + align:start position:0% +procedures will require you to perform a +reaction at a specific pH to accomplish + + align:start position:0% +reaction at a specific pH to accomplish + + + align:start position:0% +reaction at a specific pH to accomplish +this task you must understand how to + + align:start position:0% +this task you must understand how to + + + align:start position:0% +this task you must understand how to +both make a buffer and how to use a pH + + align:start position:0% +both make a buffer and how to use a pH + + + align:start position:0% +both make a buffer and how to use a pH +meter this video will demonstrate two + + align:start position:0% +meter this video will demonstrate two + + + align:start position:0% +meter this video will demonstrate two +methods of buffer preparation as well as + + align:start position:0% +methods of buffer preparation as well as + + + align:start position:0% +methods of buffer preparation as well as +proper use of the pH meter a buffer is + + align:start position:0% +proper use of the pH meter a buffer is + + + align:start position:0% +proper use of the pH meter a buffer is +an ionic compound that resists changes + + align:start position:0% +an ionic compound that resists changes + + + align:start position:0% +an ionic compound that resists changes +to its pH when strong acids or bases are + + align:start position:0% +to its pH when strong acids or bases are + + + align:start position:0% +to its pH when strong acids or bases are +added to it the amount of strong acid or + + align:start position:0% +added to it the amount of strong acid or + + + align:start position:0% +added to it the amount of strong acid or +strong base that can be neutralized by a + + align:start position:0% +strong base that can be neutralized by a + + + align:start position:0% +strong base that can be neutralized by a +particular buffer is dictated by the + + align:start position:0% +particular buffer is dictated by the + + + align:start position:0% +particular buffer is dictated by the +buffers capacity which is determined by + + align:start position:0% +buffers capacity which is determined by + + + align:start position:0% +buffers capacity which is determined by +the concentration of weak acid and weak + + align:start position:0% +the concentration of weak acid and weak + + + align:start position:0% +the concentration of weak acid and weak +base in the buffer a higher + + align:start position:0% +base in the buffer a higher + + + align:start position:0% +base in the buffer a higher +concentration of buffering reagents + + align:start position:0% +concentration of buffering reagents + + + align:start position:0% +concentration of buffering reagents +translates into greater buffering + + align:start position:0% +translates into greater buffering + + + align:start position:0% +translates into greater buffering +capacity in the first part of this video + + align:start position:0% +capacity in the first part of this video + + + align:start position:0% +capacity in the first part of this video +we will walk through two methods of + + align:start position:0% +we will walk through two methods of + + + align:start position:0% +we will walk through two methods of +buffer preparation in the first example + + align:start position:0% +buffer preparation in the first example + + + align:start position:0% +buffer preparation in the first example +you will need to prepare one liter of a + + align:start position:0% +you will need to prepare one liter of a + + + align:start position:0% +you will need to prepare one liter of a +50 mil Imola buffer for a protein that + + align:start position:0% +50 mil Imola buffer for a protein that + + + align:start position:0% +50 mil Imola buffer for a protein that +is stable at pH 7.3 the first step is + + align:start position:0% +is stable at pH 7.3 the first step is + + + align:start position:0% +is stable at pH 7.3 the first step is +choosing an appropriate buffer system + + align:start position:0% +choosing an appropriate buffer system + + + align:start position:0% +choosing an appropriate buffer system +this buffer system should produce a + + align:start position:0% +this buffer system should produce a + + + align:start position:0% +this buffer system should produce a +stable pH in the range needed and should + + align:start position:0% +stable pH in the range needed and should + + + align:start position:0% +stable pH in the range needed and should +have a capacity large enough to + + align:start position:0% +have a capacity large enough to + + + align:start position:0% +have a capacity large enough to +accommodate your solutions the weak acid + + align:start position:0% +accommodate your solutions the weak acid + + + align:start position:0% +accommodate your solutions the weak acid +used for the system must have a PKA that + + align:start position:0% +used for the system must have a PKA that + + + align:start position:0% +used for the system must have a PKA that +is plus or minus one unit of the desired + + align:start position:0% +is plus or minus one unit of the desired + + + align:start position:0% +is plus or minus one unit of the desired +pH the closer the better + + align:start position:0% +pH the closer the better + + + align:start position:0% +pH the closer the better +from this abbreviated list of weak acids + + align:start position:0% +from this abbreviated list of weak acids + + + align:start position:0% +from this abbreviated list of weak acids +the phosphate ion with a pKa of 6.8 - is + + align:start position:0% +the phosphate ion with a pKa of 6.8 - is + + + align:start position:0% +the phosphate ion with a pKa of 6.8 - is +cruely the best choice for a buffer with + + align:start position:0% +cruely the best choice for a buffer with + + + align:start position:0% +cruely the best choice for a buffer with +a desired pH of seven point three bear + + align:start position:0% +a desired pH of seven point three bear + + + align:start position:0% +a desired pH of seven point three bear +for the weak acid used for this system + + align:start position:0% +for the weak acid used for this system + + + align:start position:0% +for the weak acid used for this system +is h2 pure four - and the conjugate base + + align:start position:0% +is h2 pure four - and the conjugate base + + + align:start position:0% +is h2 pure four - and the conjugate base +is hpo4 two - which correspond to the + + align:start position:0% +is hpo4 two - which correspond to the + + + align:start position:0% +is hpo4 two - which correspond to the +salts sodium phosphate mono basic and + + align:start position:0% +salts sodium phosphate mono basic and + + + align:start position:0% +salts sodium phosphate mono basic and +sodium phosphate dibasic after + + align:start position:0% +sodium phosphate dibasic after + + + align:start position:0% +sodium phosphate dibasic after +determining an appropriate buffer system + + align:start position:0% +determining an appropriate buffer system + + + align:start position:0% +determining an appropriate buffer system +the Henderson Hasselbach equation is + + align:start position:0% +the Henderson Hasselbach equation is + + + align:start position:0% +the Henderson Hasselbach equation is +used to calculate the ratio of acid to + + align:start position:0% +used to calculate the ratio of acid to + + + align:start position:0% +used to calculate the ratio of acid to +conjugate base needed at your desired pH + + align:start position:0% +conjugate base needed at your desired pH + + + align:start position:0% +conjugate base needed at your desired pH +if your desired pH of seven point three + + align:start position:0% +if your desired pH of seven point three + + + align:start position:0% +if your desired pH of seven point three +and the pKa of the phosphate ion are + + align:start position:0% +and the pKa of the phosphate ion are + + + align:start position:0% +and the pKa of the phosphate ion are +substituted into this equation then the + + align:start position:0% +substituted into this equation then the + + + align:start position:0% +substituted into this equation then the +ratio of con + + align:start position:0% +ratio of con + + + align:start position:0% +ratio of con +to get bass to acid is calculated to be + + align:start position:0% +to get bass to acid is calculated to be + + + align:start position:0% +to get bass to acid is calculated to be +1.6 therefore your buffer must contain + + align:start position:0% +1.6 therefore your buffer must contain + + + align:start position:0% +1.6 therefore your buffer must contain +1.6 times the amount of sodium phosphate + + align:start position:0% +1.6 times the amount of sodium phosphate + + + align:start position:0% +1.6 times the amount of sodium phosphate +dibasic to sodium phosphate mono basic + + align:start position:0% +dibasic to sodium phosphate mono basic + + + align:start position:0% +dibasic to sodium phosphate mono basic +after determining the appropriate ratio + + align:start position:0% +after determining the appropriate ratio + + + align:start position:0% +after determining the appropriate ratio +of conjugate base to acid the exact + + align:start position:0% +of conjugate base to acid the exact + + + align:start position:0% +of conjugate base to acid the exact +amount of each reagent is calculated in + + align:start position:0% +amount of each reagent is calculated in + + + align:start position:0% +amount of each reagent is calculated in +the following way because you are + + align:start position:0% +the following way because you are + + + align:start position:0% +the following way because you are +planning to make one liter of a 50 mil + + align:start position:0% +planning to make one liter of a 50 mil + + + align:start position:0% +planning to make one liter of a 50 mil +Imola phosphate buffer at pH 7.3 50 + + align:start position:0% +Imola phosphate buffer at pH 7.3 50 + + + align:start position:0% +Imola phosphate buffer at pH 7.3 50 +millimolar is equal to the concentration + + align:start position:0% +millimolar is equal to the concentration + + + align:start position:0% +millimolar is equal to the concentration +of acid plus the concentration of + + align:start position:0% +of acid plus the concentration of + + + align:start position:0% +of acid plus the concentration of +conjugate base in addition you already + + align:start position:0% +conjugate base in addition you already + + + align:start position:0% +conjugate base in addition you already +know that the ratio of base to acid is + + align:start position:0% +know that the ratio of base to acid is + + + align:start position:0% +know that the ratio of base to acid is +1.6 so the concentration of base is + + align:start position:0% +1.6 so the concentration of base is + + + align:start position:0% +1.6 so the concentration of base is +equal to 1.6 times the concentration of + + align:start position:0% +equal to 1.6 times the concentration of + + + align:start position:0% +equal to 1.6 times the concentration of +acid by substituting equation 2 into + + align:start position:0% +acid by substituting equation 2 into + + + align:start position:0% +acid by substituting equation 2 into +equation 1 you can see that the + + align:start position:0% +equation 1 you can see that the + + + align:start position:0% +equation 1 you can see that the +concentration of acid plus 1.6 times the + + align:start position:0% +concentration of acid plus 1.6 times the + + + align:start position:0% +concentration of acid plus 1.6 times the +concentration of acid is equal to 50 + + align:start position:0% +concentration of acid is equal to 50 + + + align:start position:0% +concentration of acid is equal to 50 +millimolar through manipulation of this + + align:start position:0% +millimolar through manipulation of this + + + align:start position:0% +millimolar through manipulation of this +equation the concentration of acid + + align:start position:0% +equation the concentration of acid + + + align:start position:0% +equation the concentration of acid +needed for this particular buffer is + + align:start position:0% +needed for this particular buffer is + + + align:start position:0% +needed for this particular buffer is +nineteen point two millimolar and the + + align:start position:0% +nineteen point two millimolar and the + + + align:start position:0% +nineteen point two millimolar and the +concentration of base is 30.8 millimolar + + align:start position:0% +concentration of base is 30.8 millimolar + + + align:start position:0% +concentration of base is 30.8 millimolar +which corresponds to 2.30 and four point + + align:start position:0% +which corresponds to 2.30 and four point + + + align:start position:0% +which corresponds to 2.30 and four point +three seven grams respectively for a one + + align:start position:0% +three seven grams respectively for a one + + + align:start position:0% +three seven grams respectively for a one +liter solution to make the buffer simply + + align:start position:0% +liter solution to make the buffer simply + + + align:start position:0% +liter solution to make the buffer simply +dissolve 2.30 grams of sodium phosphate + + align:start position:0% +dissolve 2.30 grams of sodium phosphate + + + align:start position:0% +dissolve 2.30 grams of sodium phosphate +mono basic and four point three seven + + align:start position:0% +mono basic and four point three seven + + + align:start position:0% +mono basic and four point three seven +grams of sodium phosphate dibasic in one + + align:start position:0% +grams of sodium phosphate dibasic in one + + + align:start position:0% +grams of sodium phosphate dibasic in one +liter of distilled water an alternative + + align:start position:0% +liter of distilled water an alternative + + + align:start position:0% +liter of distilled water an alternative +method of buffer preparation is simple + + align:start position:0% +method of buffer preparation is simple + + + align:start position:0% +method of buffer preparation is simple +accurate and requires much less math to + + align:start position:0% +accurate and requires much less math to + + + align:start position:0% +accurate and requires much less math to +demonstrate this second method we will + + align:start position:0% +demonstrate this second method we will + + + align:start position:0% +demonstrate this second method we will +prepare one liter of a 1.0 millimolar + + align:start position:0% +prepare one liter of a 1.0 millimolar + + + align:start position:0% +prepare one liter of a 1.0 millimolar +Tris buffer at pH seven point six zero + + align:start position:0% +Tris buffer at pH seven point six zero + + + align:start position:0% +Tris buffer at pH seven point six zero +the first step involves the + + align:start position:0% +the first step involves the + + + align:start position:0% +the first step involves the +determination of the amount of weak acid + + align:start position:0% +determination of the amount of weak acid + + + align:start position:0% +determination of the amount of weak acid +or in this example weak base needed in + + align:start position:0% +or in this example weak base needed in + + + align:start position:0% +or in this example weak base needed in +the system to make one liter of a 1.0 + + align:start position:0% +the system to make one liter of a 1.0 + + + align:start position:0% +the system to make one liter of a 1.0 +millimolar Tris buffer 1.0 millimoles or + + align:start position:0% +millimolar Tris buffer 1.0 millimoles or + + + align:start position:0% +millimolar Tris buffer 1.0 millimoles or +121 milligrams of Tris are required at + + align:start position:0% +121 milligrams of Tris are required at + + + align:start position:0% +121 milligrams of Tris are required at +approximately 800 milliliters of + + align:start position:0% +approximately 800 milliliters of + + + align:start position:0% +approximately 800 milliliters of +distilled water as well as a stir bar to + + align:start position:0% +distilled water as well as a stir bar to + + + align:start position:0% +distilled water as well as a stir bar to +the beaker then weigh 121 milligrams of + + align:start position:0% +the beaker then weigh 121 milligrams of + + + align:start position:0% +the beaker then weigh 121 milligrams of +Tris and transfer it to a one liter + + align:start position:0% +Tris and transfer it to a one liter + + + align:start position:0% +Tris and transfer it to a one liter +beaker ensure that all of the material + + align:start position:0% +beaker ensure that all of the material + + + align:start position:0% +beaker ensure that all of the material +has been transferred by rinsing the way + + align:start position:0% +has been transferred by rinsing the way + + + align:start position:0% +has been transferred by rinsing the way +boat and transferring the rinses into + + align:start position:0% +boat and transferring the rinses into + + + align:start position:0% +boat and transferring the rinses into +the beaker while stirring monitor the pH + + align:start position:0% +the beaker while stirring monitor the pH + + + align:start position:0% +the beaker while stirring monitor the pH +of this solution and add a sodium + + align:start position:0% +of this solution and add a sodium + + + align:start position:0% +of this solution and add a sodium +hydroxide solution drop-wise until the + + align:start position:0% +hydroxide solution drop-wise until the + + + align:start position:0% +hydroxide solution drop-wise until the +pH is exactly seven point six zero the + + align:start position:0% +pH is exactly seven point six zero the + + + align:start position:0% +pH is exactly seven point six zero the +concentration of the sodium hydroxide + + align:start position:0% +concentration of the sodium hydroxide + + + align:start position:0% +concentration of the sodium hydroxide +solution doesn't really matter however a + + align:start position:0% +solution doesn't really matter however a + + + align:start position:0% +solution doesn't really matter however a +solution that is to dilute may require + + align:start position:0% +solution that is to dilute may require + + + align:start position:0% +solution that is to dilute may require +an excessive volume to be added to the + + align:start position:0% +an excessive volume to be added to the + + + align:start position:0% +an excessive volume to be added to the +buffer while a solution that is too + + align:start position:0% +buffer while a solution that is too + + + align:start position:0% +buffer while a solution that is too +concentrated may cause you to overshoot + + align:start position:0% +concentrated may cause you to overshoot + + + align:start position:0% +concentrated may cause you to overshoot +the desired pH if you do happen to + + align:start position:0% +the desired pH if you do happen to + + + align:start position:0% +the desired pH if you do happen to +exceed the desired pH then add a + + align:start position:0% +exceed the desired pH then add a + + + align:start position:0% +exceed the desired pH then add a +hydrochloric acid solution to bring the + + align:start position:0% +hydrochloric acid solution to bring the + + + align:start position:0% +hydrochloric acid solution to bring the +pH back down transfer this solution to a + + align:start position:0% +pH back down transfer this solution to a + + + align:start position:0% +pH back down transfer this solution to a +one liter volumetric flask wash the + + align:start position:0% +one liter volumetric flask wash the + + + align:start position:0% +one liter volumetric flask wash the +beaker with distilled water several + + align:start position:0% +beaker with distilled water several + + + align:start position:0% +beaker with distilled water several +times and add these washings to the + + align:start position:0% +times and add these washings to the + + + align:start position:0% +times and add these washings to the +volumetric flask dilute the buffer to + + align:start position:0% +volumetric flask dilute the buffer to + + + align:start position:0% +volumetric flask dilute the buffer to +the mark on the volumetric flask and mix + + align:start position:0% +the mark on the volumetric flask and mix + + + align:start position:0% +the mark on the volumetric flask and mix +the solution by inverting the flask + + align:start position:0% +the solution by inverting the flask + + + align:start position:0% +the solution by inverting the flask +several times for the second method of + + align:start position:0% +several times for the second method of + + + align:start position:0% +several times for the second method of +buffer preparation you needed a pH meter + + align:start position:0% +buffer preparation you needed a pH meter + + + align:start position:0% +buffer preparation you needed a pH meter +the final part of this video will + + align:start position:0% +the final part of this video will + + + align:start position:0% +the final part of this video will +discuss the proper use of this equipment + + align:start position:0% +discuss the proper use of this equipment + + + align:start position:0% +discuss the proper use of this equipment +a pH meter allows the determination of + + align:start position:0% +a pH meter allows the determination of + + + align:start position:0% +a pH meter allows the determination of +hydrogen ion activity by apetencio + + align:start position:0% +hydrogen ion activity by apetencio + + + align:start position:0% +hydrogen ion activity by apetencio +metric measurement using a glass + + align:start position:0% +metric measurement using a glass + + + align:start position:0% +metric measurement using a glass +electrode coaxial II joined to a silver + + align:start position:0% +electrode coaxial II joined to a silver + + + align:start position:0% +electrode coaxial II joined to a silver +silver chloride reference electrode when + + align:start position:0% +silver chloride reference electrode when + + + align:start position:0% +silver chloride reference electrode when +the probe is immersed in solution the + + align:start position:0% +the probe is immersed in solution the + + + align:start position:0% +the probe is immersed in solution the +reference electrode makes contact with + + align:start position:0% +reference electrode makes contact with + + + align:start position:0% +reference electrode makes contact with +the sample which completes the + + align:start position:0% +the sample which completes the + + + align:start position:0% +the sample which completes the +electrical contact between the reference + + align:start position:0% +electrical contact between the reference + + + align:start position:0% +electrical contact between the reference +electrode sample and pH electrode if the + + align:start position:0% +electrode sample and pH electrode if the + + + align:start position:0% +electrode sample and pH electrode if the +unknown solution has a different pH from + + align:start position:0% +unknown solution has a different pH from + + + align:start position:0% +unknown solution has a different pH from +the solution in the probe an electrical + + align:start position:0% +the solution in the probe an electrical + + + align:start position:0% +the solution in the probe an electrical +potential results which is registered on + + align:start position:0% +potential results which is registered on + + + align:start position:0% +potential results which is registered on +the meter this video will demonstrate + + align:start position:0% +the meter this video will demonstrate + + + align:start position:0% +the meter this video will demonstrate +the use of an orion SI 520 pH meter the + + align:start position:0% +the use of an orion SI 520 pH meter the + + + align:start position:0% +the use of an orion SI 520 pH meter the +important components of a pH meter + + align:start position:0% +important components of a pH meter + + + align:start position:0% +important components of a pH meter +include the display the probe and the + + align:start position:0% +include the display the probe and the + + + align:start position:0% +include the display the probe and the +electrode tip the electrode tip contains + + align:start position:0% +electrode tip the electrode tip contains + + + align:start position:0% +electrode tip the electrode tip contains +a fragile glass bulb be extremely + + align:start position:0% +a fragile glass bulb be extremely + + + align:start position:0% +a fragile glass bulb be extremely +careful not to hit the probe on the side + + align:start position:0% +careful not to hit the probe on the side + + + align:start position:0% +careful not to hit the probe on the side +of a beaker and when using stir bars to + + align:start position:0% +of a beaker and when using stir bars to + + + align:start position:0% +of a beaker and when using stir bars to +operate the pH meter first make sure + + align:start position:0% +operate the pH meter first make sure + + + align:start position:0% +operate the pH meter first make sure +that the electrode is connected to the + + align:start position:0% +that the electrode is connected to the + + + align:start position:0% +that the electrode is connected to the +meter then calibrate the pH meter the pH + + align:start position:0% +meter then calibrate the pH meter the pH + + + align:start position:0% +meter then calibrate the pH meter the pH +meter must be recalibrated every time + + align:start position:0% +meter must be recalibrated every time + + + align:start position:0% +meter must be recalibrated every time +you turn it on and after three to four + + align:start position:0% +you turn it on and after three to four + + + align:start position:0% +you turn it on and after three to four +hours of use we will + + align:start position:0% +hours of use we will + + + align:start position:0% +hours of use we will +perform a two-point calibration this + + align:start position:0% +perform a two-point calibration this + + + align:start position:0% +perform a two-point calibration this +method involves calibrating the pH meter + + align:start position:0% +method involves calibrating the pH meter + + + align:start position:0% +method involves calibrating the pH meter +with two different buffers of known pH + + align:start position:0% +with two different buffers of known pH + + + align:start position:0% +with two different buffers of known pH +turn on the instrument and select the pH + + align:start position:0% +turn on the instrument and select the pH + + + align:start position:0% +turn on the instrument and select the pH +mode as 0.1 or 0.1 then press the ISO + + align:start position:0% +mode as 0.1 or 0.1 then press the ISO + + + align:start position:0% +mode as 0.1 or 0.1 then press the ISO +button and verify that the pH reads + + align:start position:0% +button and verify that the pH reads + + + align:start position:0% +button and verify that the pH reads +seven point zero zero rinse off the + + align:start position:0% +seven point zero zero rinse off the + + + align:start position:0% +seven point zero zero rinse off the +probe with distilled water into a waste + + align:start position:0% +probe with distilled water into a waste + + + align:start position:0% +probe with distilled water into a waste +beaker and gently blot it with a kimwipe + + align:start position:0% +beaker and gently blot it with a kimwipe + + + align:start position:0% +beaker and gently blot it with a kimwipe +place the probe into the first buffer + + align:start position:0% +place the probe into the first buffer + + + align:start position:0% +place the probe into the first buffer +and press the Cal button the number one + + align:start position:0% +and press the Cal button the number one + + + align:start position:0% +and press the Cal button the number one +should appear on the display the display + + align:start position:0% +should appear on the display the display + + + align:start position:0% +should appear on the display the display +will alternate between one and the pH + + align:start position:0% +will alternate between one and the pH + + + align:start position:0% +will alternate between one and the pH +value of the solution wait until the + + align:start position:0% +value of the solution wait until the + + + align:start position:0% +value of the solution wait until the +display stabilizes and press Enter the + + align:start position:0% +display stabilizes and press Enter the + + + align:start position:0% +display stabilizes and press Enter the +number two should then appear on the + + align:start position:0% +number two should then appear on the + + + align:start position:0% +number two should then appear on the +display rinse the probe with distilled + + align:start position:0% +display rinse the probe with distilled + + + align:start position:0% +display rinse the probe with distilled +water flat it with a kimwipe and place + + align:start position:0% +water flat it with a kimwipe and place + + + align:start position:0% +water flat it with a kimwipe and place +it into the second buffer if your + + align:start position:0% +it into the second buffer if your + + + align:start position:0% +it into the second buffer if your +solution has an acidic pH then use the + + align:start position:0% +solution has an acidic pH then use the + + + align:start position:0% +solution has an acidic pH then use the +4.01 buffer if it has a basic pH use the + + align:start position:0% +4.01 buffer if it has a basic pH use the + + + align:start position:0% +4.01 buffer if it has a basic pH use the +ten point zero one buffer the display + + align:start position:0% +ten point zero one buffer the display + + + align:start position:0% +ten point zero one buffer the display +will alternate between two and the pH + + align:start position:0% +will alternate between two and the pH + + + align:start position:0% +will alternate between two and the pH +value of the solution wait until the + + align:start position:0% +value of the solution wait until the + + + align:start position:0% +value of the solution wait until the +display stabilizes and press enter the + + align:start position:0% +display stabilizes and press enter the + + + align:start position:0% +display stabilizes and press enter the +letters pH will be displayed indicating + + align:start position:0% +letters pH will be displayed indicating + + + align:start position:0% +letters pH will be displayed indicating +that the pH meter is now ready to take + + align:start position:0% +that the pH meter is now ready to take + + + align:start position:0% +that the pH meter is now ready to take +measurements before taking a measurement + + align:start position:0% +measurements before taking a measurement + + + align:start position:0% +measurements before taking a measurement +make sure that your sample buffer is at + + align:start position:0% +make sure that your sample buffer is at + + + align:start position:0% +make sure that your sample buffer is at +the same temperature you'll be using in + + align:start position:0% +the same temperature you'll be using in + + + align:start position:0% +the same temperature you'll be using in +your experiments because pH is + + align:start position:0% +your experiments because pH is + + + align:start position:0% +your experiments because pH is +temperature dependent + + align:start position:0% +temperature dependent + + + align:start position:0% +temperature dependent +rinse and blot the probe and place it + + align:start position:0% +rinse and blot the probe and place it + + + align:start position:0% +rinse and blot the probe and place it +into the buffer wait for the display to + + align:start position:0% +into the buffer wait for the display to + + + align:start position:0% +into the buffer wait for the display to +stabilize and record the pH correct + + align:start position:0% +stabilize and record the pH correct + + + align:start position:0% +stabilize and record the pH correct +buffer preparation and pH meter + + align:start position:0% +buffer preparation and pH meter + + + align:start position:0% +buffer preparation and pH meter +technique are essential to ensure that + + align:start position:0% +technique are essential to ensure that + + + align:start position:0% +technique are essential to ensure that +your proteins and other sensitive + + align:start position:0% +your proteins and other sensitive + + + align:start position:0% +your proteins and other sensitive +chemicals live long functional lives + + align:start position:0% + + + + align:start position:0% + +[Music] \ No newline at end of file diff --git a/H_k1w3cfny8.txt b/H_k1w3cfny8.txt new file mode 100644 index 0000000000000000000000000000000000000000..22b8620586fab872aa863db9994e74df3f0f5aad --- /dev/null +++ b/H_k1w3cfny8.txt @@ -0,0 +1,2294 @@ +The following content is +provided under a Creative + +Commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high quality educational +resources for free. + +To make a donation or view +additional materials from + +hundreds of MIT courses, visit +MIT OpenCourseWare at + +ocw.mit.edu. + +PROFESSOR: So today's agenda +is to say a few more things + +about continuous random +variables. + +Mainly we're going to talk a +little bit about inference. + +This is a topic that we're going +to revisit at the end of + +the semester. + +But there's a few things +that we can + +already say at this point. + +And then the new topic for +today is the subject of + +derived distributions. + +Basically if you know the +distribution of one random + +variable, and you have a +function of that random + +variable, how to find a + +distribution for that function. + +And it's a fairly mechanical +skill, but that's an important + +one, so we're going +to go through it. + +So let's see where we stand. + +Here is the big picture. + +That's all we have +done so far. + +We have talked about discrete +random variables, which we + +described by probability +mass function. + +So if we have multiple random +variables, we describe them + +with the a joint +mass function. + +And then we define conditional +probabilities, or conditional + +PMFs, and the three are related +according to this + +formula, which is, you can +think of it either as the + +definition of conditional +probability. + +Or as the multiplication rule, +the probability of two things + +happening is the product of the +probabilities of the first + +thing happening, and then the +second happening, given that + +the first has happened. + +There's another relation between +this, which is the + +probability of x occurring, is +the sum of the different + +probabilities of the different +ways that x may occur, which + +is in conjunction with different +values of y. + +And there's an analog of all +that in the continuous world, + +where all you do is to replace +p's by f's, and replace sums + +by integrals. + +So the formulas all +look the same. + +The interpretations are a little +more subtle, so the f's + +are not probabilities, they're +probability densities. + +So they're probabilities per +unit length, or in the case of + +joint PDf's, these are +probabilities per unit area. + +So they're densities +of some sort. + +Probably the more subtle concept +to understand what it + +really is the conditional +density. + +In some sense, it's simple. + +It's just the density of X in +a world where you have been + +told the value of the random +variable Y. It's a function + +that has two arguments, but the +best way to think about it + +is to say that we fixed y. + +We're told the value of the +random variable Y, and we look + +at it as a function of x. + +So as a function of x, the +denominator is a constant, and + +it just looks like the +joint density. + +when we keep y fixed. + +So it's really a function of +one argument, just the + +argument x. + +And it has the same shape as the +joint's density when you + +take that slice of it. + +So conditional PDFs are just +slices of joint PDFs. + +There's a bunch of concepts, +expectations, variances, + +cumulative distribution +functions that apply equally + +well for to both universes +of discrete or + +continuous random variables. + +So why is probability useful? + +Probability is useful because, +among other things, we use it + +to make sense of the +world around us. + +We use it to make inferences +about things that we do not + +see directly. + +And this is done in a +very simple manner + +using the base rule. + +We've already seen some of that, +and now we're going to + +revisit it with a bunch of +different variations. + +And the variations come because +sometimes our random + +variable are discrete, sometimes +they're continuous, + +or we can have a combination +of the two. + +So the big picture is that +there's some unknown random + +variable out of there, and we +know the distribution that's + +random variable. + +And in the discrete case, it's +going to be given by PMF. + +In the continuous case, +it's given a PDF. + +Then we have some phenomenon, +some noisy phenomenon or some + +measuring device, and that +measuring device produces + +observable random variables Y. + +We don't know what x is, but we +have some beliefs about how + +X is distributed. + +We observe the random variable +Y. We need a + +model of this box. + +And the model of that box is +going to be either a PMF, for + +the random variable Y. And that +model tells us, if the + +true state of the world is X, +how do we expect to Y to be + +distributed? + +That's for the case where +Y is this discrete. + +If Y is a continuous, you might +instead have a density + +for Y, or something +of that form. + +So in either case, this +should be a function + +that's known to us. + +This is our model of the +measuring device. + +And now having observed +y, we want to make + +inferences about x. + +What does it mean to +make inferences? + +Well the most complete answer in +the inference problem is to + +tell me the probability +distribution + +of the unknown quantity. + +But when I say the probability +distribution, I + +don't mean this one. + +I mean the probability +distribution that takes into + +account the measurements +that you got. + +So the output of an inference +problem is to come up with the + +distribution of X, the unknown +quantity, given what we have + +already observed. + +And in the discrete case, it +would be an object like that. + +If X is continuous, it would +be an object of this kind. + +OK, so we're given conditional +probabilities of this type, + +and we want to get conditional +distributions of the opposite + +type where the order of the + +conditioning is being reversed. + +So the starting point +is always a formula + +such as this one. + +The probability of x happening, +and then y + +happening given that +x happens. + +This is the probability that +a particular x and y happen + +simultaneously. + +But this is also equal to the +probability that y happens, + +and then that x happens, given +that y has happened. + +And you take this expression +and send one term to the + +denominator of the other side, +and this gives us the base + +rule for the discrete case. + +Which is this one that you have +already seen, and you + +have played with it. + +So this is what the formula +looks like in + +the discrete case. + +And the typical example where +both random variables are + +discrete is the one we discussed +some time ago. + +X is, let's say, a binary +variable, or whether an + +airplane is present +up there or not. + +Y is a discrete measurement, for +example, whether our radar + +beeped or it didn't beep. + +And we make inferences and +calculate the probability that + +the plane is there, or the +probability that the plane is + +not there, given the measurement +that we have made. + +And of course X and Y do not +need to be just binary. + +They could be more general +discrete random variables. + +So how does the story change +in the continuous case? + +First, what's a possible +application of + +the continuous case? + +Well, think of X as being some +signal that takes values over + +a continuous range. + +Let's say X is the current +through a resistor. + +And then you have some measuring +device that measures + +currents, but that device is +noisy, it gets hit, let's say + +for example, by Gaussian +noise. + +And the Y that you observe is a +noisy version of X. But your + +instruments are analog, so +you measure things on + +a continuous scale. + +What are you going to +do in that case? + +Well the inference problem, the +output of the inference + +problem, is going to be the +conditional distribution of X. + +What do you think your current +is based on a particular value + +of Y that you have observed? + +So the output of our inference +problem is, given the specific + +value of Y, to calculate this +entire function as a function + +of x, and then go and plot it. + +How do we calculate it? + +You go through the same +calculation as in the discrete + +case, except that all of the +x's gets replaced by p's. + +In the continuous case, it's +equally true that the joint's + +density is the product of the +marginal density with the + +conditional density. + +So the formula is still +valid with just a + +little change of notation. + +So we end up with the same +formula here, except that we + +replace x's with p's. + +So all of these functions +are known to us. + +We have formulas for them. + +We fix a specific value of y, +we plug it in, so we're left + +with a function of x. + +And that gives us the posterior +distribution. + +Actually there's also a +denominator term that's not + +necessarily given to us, but we +can always calculate it if + +we have the marginal of X, +and we have the model for + +measuring device. + +Then we can always find the +marginal distribution of Y. So + +this quantity, that number, is +in general a known one, as + +well, and doesn't give +us any problems. + +So to complicate things a little +bit, we can also look + +into situations where our two +random variables are of + +different kinds. + +For example, one random variable +could be discrete, + +and the other it might +be continuous. + +And there's two versions. + +Here one version is when X is +discrete, but Y is continuous. + +What's an example of this? + +Well suppose that I send a +single bit of information so + +my X is 0 or 1. + +And what I measure is Y, +which is X plus, let's + +say, Gaussian noise. + +This is the standard example +that shows up in any textbook + +on communication, or +signal processing. + +You send a single bit, but what +you observe is a noisy + +version of that bit. + +You start with a model +of your x's. + +These would be your prior +probabilities. + +For example, you might be +believe that either 0 or 1 are + +equally likely, in which case +your PMF gives equal weight to + +two possible values. + +And then we need a model of +our measuring device. + +This is one specific model. + +The general model would have +a shape such as follows. + +Y has a distribution, +its density. + +And that density, however, +depends on the value of X. + +So when x is 0, we might get +a density of this kind. + +And when x is 1, we might +get the density + +of a different kind. + +So these are the conditional +densities of y in a universe + +that's specified by a particular +value of x. + +And then we go ahead and +do our inference. + +OK, what's the right formula +for doing this inference? + +We need a formula that's sort of +an analog of this one, but + +applies to the case where we +have two random variables of + +different kinds. + +So let me just redo this +calculation here. + +Except that I'm not going to +have a probability of taking + +specific values. + +It will have to be something +a little different. + +So here's how it goes. + +Let's look at the probability +that X takes a specific value + +that makes sense in the discrete +case, but for the + +continuous random variable, +let's look at the probability + +that it takes values in +some little interval. + +And now this probability of +two things happening, I'm + +going to write it +as a product. + +And I'm going to write +this as a product in + +two different ways. + +So one way is to say that this +is the probability that X + +takes that value and then given +that X takes that value, + +the probability that Y falls +inside that interval. + +So this is our usual +multiplication rule for + +multiplying probabilities, but +I can use the multiplication + +rule also in a different way. + +It's the probability +that Y falls in + +the range of interest. + +And then the probability that X +takes the value of interest + +given that Y satisfies +the first condition. + +So this is something that's +definitely true. + +We're just using the +multiplication rule. + +And now let's translate it +into PMF is PDF notation. + +So the entry up there is the +PMF of X evaluated at x. + +The second entry, what is it? + +Well probabilities of +little intervals are + +given to us by densities. + +But we are in the conditional +universe where X takes on a + +particular value. + +So it's going to be the density +of Y given the value + +of X times delta. + +So probabilities of little +intervals are given by the + +density times the length of +the little interval, but + +because we're working in the +conditional universe, it has + +to be the conditional density. + +Now let's try the second +expression. + +This is the probability +that the Y falls + +into the little interval. + +So that's the density +of Y times delta. + +And then here we have an +object which is the + +conditional probability X in a +universe where the value of Y + +is given to us. + +Now this relation is sort +of approximate. + +This is true for very small +delta in the limit. + +But we can cancel the deltas +from both sides, and we're + +left with a formula that links +together PMFs and PDFs. + +Now this may look terribly +confusing because there's both + +p's and f's involved. + +But the logic should be clear. + +If a random variable +is discrete, it's + +described by PMF. + +So here we're talking about +the PMF of X in some + +particular universe. + +X is discrete, so +it has a PMF. + +Similarly here. + +Y is continuous so it's +described by a PDF. + +And even in the conditional +universe where I tell you the + +value of X, Y is still a +continuous random variable, so + +it's been described by a PDF. + +So this is the basic +relation that links + +together PMF and PDFs. + +In this mixed the world. + +And now in this inequality, +you can take this term and + +send it to the new denominator +to the other side. + +And what you end up with +is the formula + +that we have up here. + +And this is a formula that we +can use to make inferences + +about the discrete random +variable X when we're told the + +value of the continuous random +variable Y. The probability + +that X takes on a particular +value has something + +to do with the prior. + +And other than that, it's +proportional to this quantity, + +the conditional of Y given X. +So these are the quantities + +that we plotted here. + +Suppose that the x's are equally +likely in your prior, + +so we don't really care +about that term. + +It tells us that the posterior +of X is proportional to that + +particular density under +the given x's. + +So in this picture, if I were to +get a particular y here, I + +would say that x equals 1 +has a probability that's + +proportional to this quantity. + +x equals 0 has a probability +that's + +proportional to this quantity. + +So the ratio of these two +quantities gives us the + +relative odds of the different +x's given the y + +that we have observed. + +So we're going to come back to +this topic and redo plenty of + +examples of these kinds towards +the end of the class, + +when we spend some +time dedicated + +to inference problems. + +But already at this stage, we +sort of have the basic skills + +to deal with a lot of that. + +And it's useful at this +point to pull all + +the formulas together. + +So finally let's look at the +last case that's remaining. + +Here we have a continuous +phenomenon that we're trying + +to measure, but our measurements +are discrete. + +What's an example where +this might happen? + +So you have some device that +emits light, and you drive it + +with a current that has +a certain intensity. + +You don't know what that +current is, and it's a + +continuous random variable. + +But the device emits +light by sending + +out individual photons. + +And your measurement is some +other device that counts how + +many photons did you get +in a single second. + +So if we have devices that emit +a very low intensity you + +can actually start counting +individual photons as they're + +being observed. + +So we have a discrete +measurement, which is the + +number of problems, and we +have a continuous hidden + +random variable that we're +trying to estimate. + +What do we do in this case? + +Well we start again with a +formula of this kind, and send + +the p term to the denominator. + +And that's the formula that we +use there, except that the + +roles of x's and y's +are interchanged. + +So since here we have Y being +discrete, we should change all + +the subscripts. + +It would be p_Y f_X given +y f_X, and P(Y given X). + +So just change all +those subscripts. + +Because now what we're used to +be continuous became discrete, + +and vice versa. + +Take that formula, send +the other terms to the + +denominator, and we have a +formula for the density, or X, + +given the particular +measurements for Y that we + +have obtained. + +In some sense that's all there +is in Bayesian inference. + +It's using these very simple +one line formulas. + +But why are there people then +who make their living solving + +inference problems? + +Well, the devil is +in the details. + +As we're going to discuss, +there are some real world + +issues of how exactly do you +design your f's, how do you + +model your system, then how do +you do your calculations. + +This might not be always easy. + +For example, there's certain +integrals or sums that have to + +be evaluated, which may be +hard to do and so on. + +So this object is +a lot of richer + +than just these formulas. + +On the other hand, at the +conceptual level, that's the + +basis for Bayesian inference, +that these + +are the basic concepts. + +All right, so now let's change +gear and move to the new + +subject, which is the topic of +finding the distribution of a + +functional for a random +variable. + +We call those distributions +derived distributions, because + +we're given the distribution +of X. We're interested in a + +function of X. We want to derive +the distribution of + +that function based on +the distribution + +that we already know. + +So it could be a function of +just one random variable. + +It could be a function of +several random variables. + +So one example that we are going +to solve at some point, + +let's say you have to run the +variables X and Y. Somebody + +tells you their distribution, +for example, is a uniform of + +the square. + +For some reason, you're +interested in the ratio of + +these two random variables, +and you want to find the + +distribution of that ratio. + +You can think of lots of cases +where your random variable of + +interest is created by taking +some other unknown variables + +and taking a function of them. + +And so it's legitimate to care +about the distribution of that + +random variable. + +A caveat, however. + +There's an important case where +you don't need to find + +the distribution of that +random variable. + +And this is when you want to +calculate the expectations. + +If all you care about is the +expected value of this + +function of the random +variables, you can work + +directly with the distribution +of the original random + +variables without ever having +to find the PDF of g. + +So you don't do unnecessary work +if it's not needed, but + +if it's needed, or if you're +asked to do it, + +then you just do it. + +So how do we find the +distribution of the function? + +As a warm-up, let's look +at the discrete case. + +Suppose that X is a discrete +random variable and takes + +certain values. + +We have a function g that +maps x's into y's. + +And we want to find the +probability mass function for + +Y. + +So for example, if I'm +interested in finding the + +probability that Y takes on +this particular value, how + +would they find it? + +Well I ask, what are the +different ways that these + +particular y value can happen? + +And the different ways that it +can happen is either if x + +takes this value, or if +X takes that value. + +So we identify this event in the +y space with that event in + +the x space. + +These two events +are identical. + +X falls in this set if and only +if Y falls in that set. + +Therefore, the probability of +Y falling in that set is the + +probability of X falling +in that set. + +The probability of X falling in +that set is just the sum of + +the individual probabilities +of the x's in this set. + +So we just add the probabilities +of the different + +x's where the summation is taken +over all x's that leads + +to that particular value of y. + +Very good. + +So that's all there is +in the discrete case. + +It's a very nice and simple. + +So let's transfer +these methods to + +the continuous case. + +Suppose we are in the +continuous case. + +Suppose that X and Y now can +take values anywhere. + +And I try to use same methods +and I ask, what is the + +probability that Y is going +to take this value? + +At least if the diagram is this +way, you would say this + +is the same as the probability +that X takes this value. + +So I can find the probability +of Y being this in terms of + +the probability of +X being that. + +Is this useful? + +In the continuous +case, it's not. + +Because in the continuous case, +any single value has 0 + +probability. + +So what you're going to get out +of this argument is that + +the probability Y takes this +value is 0, is equal to the + +probability that X takes that +value which also 0. + +That doesn't help us. + +We want to do something more. + +We want to actually find, +perhaps, the density of Y, as + +opposed to the probabilities +of individual y's. + +So to find the density of Y, +you might argue as follows. + +I'm looking at an interval for +y, and I ask what's the + +probability of falling +in this interval. + +And you go back and find the +corresponding set of x's that + +leads to those y's, and equate +those two probabilities. + +The probability of all of those +y's collectively should + +be equal to the probability of +all of the x's that map into + +that interval collectively. + +And this way you can +relate the two. + +As far as the mechanics go, in +many cases it's easier to not + +to work with little intervals, +but instead to work with + +cumulative distribution +functions that used to work + +with sort of big intervals. + +So you can instead do +a different picture. + +Look at this set of y's. + +This is the set of y's +that are smaller + +than a certain value. + +The probability of this set +is given by the cumulative + +distribution of the +random variable Y. + +Now this set of y's gets +produced by some corresponding + +set of x's. + +Maybe these are the x's that +map into y's in that set. + +And then we argue as follows. + +The probability that the Y falls +in this interval is the + +same as the probability that +X falls in that interval. + +So the event of Y falling here +and the event of X falling + +there are the same, so their +probabilities must be equal. + +And then I do the calculations +here. + +And I end up getting the +cumulative distribution + +function of Y. Once I have the +cumulative, I can get the + +density by just differentiating. + +So this is the general cookbook +procedure that we + +will be using to calculate +it derived distributions. + +We're interested in a random +variable Y, which is a + +function of the x's. + +We will aim at obtaining the +cumulative distribution of Y. + +Somehow, manage to calculate the +probability of this event. + +Once we get it, and what I mean +by get it, I don't mean + +getting it for a single +value of little y. + +You need to get this +for all little y's. + +So you need to get the +function itself, the + +cumulative distribution. + +Once you get it in that form, +then you can calculate the + +derivative at any particular +point. + +And this is going to give +you the density of Y. + +So a simple two-step +procedure. + +The devil is in the details of +how you carry the mechanics. + +So let's do one first example. + +Suppose that X is a uniform +random variable, takes values + +between 0 and 2. + +We're interested in the random +variable Y, which is the cube + +of X. What kind of distribution + +is it going to have? + +Now first notice that Y takes +values between 0 and 8. + +So X is uniform, so all the +x's are equally likely. + +You might then say, well, in +that case, all the y's should + +be equally likely. + +So Y might also have a +uniform distribution. + +Is this true? + +We'll find out. + +So let's start applying the +cookbook procedure. + +We want to find first the +cumulative distribution of the + +random variable Y, which by +definition is the probability + +that the random variable is +less than or equal to a + +certain number. + +That's what we want to find. + +What we have in our hands is the +distribution of X. That's + +what we need to work with. + +So the first step that you need +to do is to look at this + +events and translate it, and +write it in terms of the + +random variable about which you +know you have information. + +So Y is X cubed, so this event +is the same as that event. + +So now we can forget +about the y's. + +It's just an exercise involving +a single random + +variable with a known +distribution and we want to + +calculate the probability +of some event. + +So we're looking +at this event. + +X cubed being less than or equal +to Y. We massage that + +expression so that's it involves +X directly, so let's + +take cubic roots of both sides +of this inequality. + +This event is the same as the +event that X is less than or + +equal to Y to the 1/3. + +Now with a uniform distribution +on [0,2], what is + +that probability going to be? + +It's the probability of being in +the interval from 0 to y to + +the 1/3, so it's going to be in +the area under the uniform + +going up to that point. + +And what's the area under +that uniform? + +So here's x. + +Here is the distribution +of X. It goes up to 2. + +The distribution of +X is this one. + +We want to go up to +y to the 1/3. + +So the probability for this +event happening is this area. + +And the area is equal to the +base, which is y to the 1/3 + +times the height. + +What is the height? + +Well since the density must +integrate to 1, the total area + +under the curve has to be 1. + +So the height here is 1/2, and +that explains why we get the + +1/2 factor down there. + +So that's the formula for the +cumulative distribution. + +And then the rest is easy. + +You just take derivatives. + +You differentiate this +expression with respect to y + +1/2 times 1/3, and y +drops by one power. + +So you get y to 2/3 in +the denominator. + +So if you wish to plot this, +it's 1/y to the 2/3. + +So when y goes to 0, it sort +of blows up and it + +goes on this way. + +Is this picture correct +the way I've drawn it? + +What's wrong with it? + +[? AUDIENCE: Something. ?] + +PROFESSOR: Yes. + +y only takes values +from 0 to 8. + +This formula that I wrote here +is only correct when the + +preview picture applies. + +I took my y to the 1/3 to +be between 0 and 2. + +So this formula here is only +correct for y between 0 and 8. + +And for that reason, the formula +for the derivative is + +also true only for a +y between 0 and 8. + +And any other values of why are +impossible, so they get + +zero density. + +So to complete the picture +here, the PDF of y has a + +cut-off of 8, and it's also +0 everywhere else. + +And one thing that we see is +that the distribution of Y is + +not uniform. + +Certain y's are more likely than +others, even though we + +started with a uniform random + +variable X. All right. + +So we will keep doing examples +of this kind, a sequence of + +progressively more interesting +or more complicated. + +So that's going to continue +in the next lecture. + +You're going to see plenty of +examples in your recitations + +and tutorials and so on. + +So let's do one that's pretty +similar to the one that we + +did, but it's going to add to +just a small twist in how we + +do the mechanics. + +OK so you set your +cruise control + +when you start driving. + +And you keep driving at the +constants based at the + +constant speed. + +Where you set your cruise +control is somewhere + +between 30 and 60. + +You're going to drive +a distance of 200. + +And so the time it's going to +take for your trip is 200 over + +the setting of your +cruise control. + +So it's 200/V. + +Somebody gives you the +distribution of V, and they + +tell you not only it's between +30 and 60, it's roughly + +equally likely to be anything +between 30 and 60, so we have + +a uniform distribution +over that range. + +So we have a distribution of +V. We want to find the + +distribution of the random +variable T, which is the time + +it takes till your trip ends. + +So how are we going +to proceed? + +We'll use the exact same +cookbook procedure. + +We're going to start by +finding the cumulative + +distribution of T. +What is this? + +By definition, the cumulative +distribution is the + +probability that T is less +than a certain number. + +OK. + +Now we don't know the +distribution of T, so we + +cannot to work with these +event directly. + +But we take that event and +translate it into T-space. + +So we replace the t's by what we +know T to be in terms of V + +or + +the v's All right. + +So we have the distribution +of V. So now let's + +calculate this quantity. + +OK. + +Let's massage this event and +rewrite it as the probability + +that V is larger or +equal to 200/T. + +So what is this going to be? + +So let's say that 200/T +is some number that + +falls inside the range. + +So that's going to be true if +200/T is bigger than 30, and + +less than 60. + +Which means that t is +less than 30/200. + +No, 200/30. + +And bigger than 200/60. + +So for t's inside that range, +this number 200/t falls inside + +that range. + +This is the range of t's that +are possible, given the + +description of the problem +the we have set up. + +So for t's in that range, what +is the probability that V is + +bigger than this number? + +So V being bigger than that +number is the probability of + +this event, so it's going to be +the area under this curve. + +So the area under that curve +is the height of the curve, + +which is 1/3 over 30 +times the base. + +How big is the base? + +Well it's from that point to 60, +so the base has a length + +of 60 minus 200/t. + +And this is a formula which is +valid for those t's for which + +this picture is correct. + +And this picture is correct if +200/T happens to fall in this + +interval, which is the same as +T falling in that interval, + +which are the t's that +are possible. + +So finally let's find the +density of T, which is what + +we're looking for. + +We find this by taking the +derivative in this expression + +with respect to t. + +We only get one term +from here. + +And this is going to be 200/30, +1 over t squared. + +And this is the formula for +the density for t's in the + +allowed to range. + +OK, so that's the end of the +solution to this particular + +problem as well. + +I said that there was a little +twist compared to + +the previous one. + +What was the twist? + +Well the twist was that in the +previous problem we dealt with + +the X cubed function, which was +monotonically increasing. + +Here we dealt with the +function that was + +monotonically decreasing. + +So when we had to find the +probability that T is less + +than something, that translated +into an event that + +V was bigger than something. + +Your time is less than something +if and only if your + +velocity is bigger +than something. + +So for when you're dealing +with the monotonically + +decreasing function, at some +point some inequalities will + +have to get reversed. + +Finally let's look at +a very useful one. + +Which is the case where we take +a linear function of a + +random variable. + +So X is a random variable with +given distribution, and we can + +see there is a linear +function. + +So in this particular instance, +we take a to be + +equal to 2 and b equal to 5. + +And let us first argue +just by picture. + +So X is a random variable that +has a given distribution. + +Let's say it's this +weird shape here. + +And x ranges from -1 to +2. + +Let's do things one +step at the time. + +Let's first find the +distribution of 2X. + +Why do you think you +know about 2X? + +Well if x ranges from -1 to 2, +then the random variable X is + +going to range from -2 to +4. + +So that's what the range +is going to be. + +Now dealing with the random +variable 2X, as opposed to the + +random variable X, in some sense +it's just changing the + +units in which we measure +that random variable. + +It's just changing the +scale on which we + +draw and plot things. + +So if it's just a scale change, +then intuition should + +tell you that the random +variable X should have a PDF + +of the same shape, except that +it's scaled out by a factor of + +2, because our random variable +of 2X now has a range that's + +twice as large. + +So we take the same PDF and +scale it up by stretching the + +x-axis by a factor of 2. + +So what does scaling +correspond to + +in terms of a formula? + +So the distribution of 2X as a +function, let's say, a generic + +argument z, is going to be the +distribution of X, but scaled + +by a factor of 2. + +So taking a function and +replacing its arguments by the + +argument over 2, what it +does is it stretches it + +by a factor of 2. + +You have probably been tortured +ever since middle + +school to figure out when need +to stretch a function, whether + +you need to put 2z or z/2. + +And the one that actually does +the stretching is to put the + +z/2 in that place. + +So that's what the +stretching does. + +Could that to be the +full answer? + +Well there's a catch. + +If you stretch this function by +a factor of 2, what happens + +to the area under +the function? + +It's going to get doubled. + +But the total probability must +add up to 1, so we need to do + +something else to make sure that +the area under the curve + +stays to 1. + +So we need to take that function +and scale it down by + +this factor of 2. + +So when you're dealing with a +multiple of a random variable, + +what happens to the PDF is you +stretch it according to the + +multiple, and then scale it +down by the same number so + +that you preserve the area +under that curve. + +So now we found the distribution +of 2X. + +How about the distribution +of 2X + 5? + +Well what does adding 5 +to random variable do? + +You're going to get essentially +the same values + +with the same probability, +except that those values all + +get shifted by 5. + +So all that you need to do is +to take this PDF here, and + +shift it by 5 units. + +So the range used to +be from -2 to 4. + +The new range is going +to be from 3 to 9. + +And that's the final answer. + +This is the distribution of +2X + 5, starting with this + +particular distribution of X. + +Now shifting to the +right by b, what + +does it do to a function? + +Shifting to the right to +by a certain amount, + +mathematically, it corresponds +to putting -b in the argument + +of the function. + +So I'm taking the formula that +I had here, which is the + +scaling by a factor of a. + +The scaling down to keep the +total area equal to 1. + +And then I need to introduce +this extra + +term to do the shifting. + +So this is a plausible +argument. + +The proof by picture that this +should be the right answer. + +But just in order to keep our +skills tuned and refined, let + +us do this derivation in a +more formal way using our + +two-step cookbook procedure. + +And I'm going to do it under +the assumption that a is + +positive, as in the example +that's we just did. + +So what's the two-step +procedure? + +We want to find the cumulative +of Y, and after that we're + +going to differentiate. + +By definition the cumulative +is the probability that the + +random variable takes values +less than a certain number. + +And now we need to take this +event and translate it, and + +express it in terms of the +original random variables. + +So Y is, by definition, +aX + b, so we're + +looking at this event. + +And now we want to express this +event in a clean form + +where X shows up in +a straight way. + +Let's say I'm going to massage +this event and + +write it in this form. + +For this inequality to be true, +x should be less than or + +equal to (y minus +b) divided by a. + +OK, now what is this? + +This is the cumulative +distribution of X evaluated at + +the particular point. + +So we got a formula for the +cumulative Y based on the + +cumulative of X. What's +the next step? + +Next step is to take derivatives +of both sides. + +So the density of Y is going to +be the derivative of this + +expression with respect to y. + +OK, so now here we need +to use the chain rule. + +It's going to be the derivative +of the F function + +with respect to its argument. + +And then we need to take the +derivative of the argument + +with respect to y. + +What is the derivative +of the cumulative? + +The derivative of +the cumulative + +is the density itself. + +And we evaluate it at the +point of interest. + +And then the chain rule tells +us that we need to take the + +derivative of this with +respect to y, and the + +derivative of this with +respect to y is 1/a. + +And this gives us the formula +which is consistent with what + +I had written down here, +for the case where a + +is a positive number. + +What if a was a negative +number? + +Could this formula be true? + +Of course not. + +Densities cannot be +negative, right? + +So that formula cannot +be true. + +Something needs to change. + +What should change? + +Where does this argument break +down when a is negative? + +So when I write this inequality +in this form, I + +divide by a. + +But when you divide by a +negative number, the direction + +of an inequality is +going to change. + +So when a is negative, this +inequality becomes larger than + +or equal to. + +And in that case, the expression +that I have up + +there would change when this +is larger than here. + +Instead of getting the +cumulative, I would get 1 + +minus the cumulative of (y +minus b) divided by a. + +So this is the probability that +X is bigger than this + +particular number. + +And now when you take the +derivatives, there's going to + +be a minus sign that shows up. + +And that minus sign will +end up being here. + +And so we're taking the negative +of a negative number, + +and that basically is equivalent +to taking the + +absolute value of that number. + +So all that happens when we have +a negative a is that we + +have to take the absolute value +of the scaling factor + +instead of the factor itself. + +All right, so this general +formula is quite useful for + +dealing with linear functions +of random variables. + +And one nice application of it +is to take the formula for a + +normal random variable, consider +a linear function of + +a normal random variable, plug +into this formula, and what + +you will find is that Y also +has a normal distribution. + +So using this formula, now we +can prove a statement that I + +had made a couple of lectures +ago, that a linear function of + +a normal random variable +is also linear. + +That's how you would prove it. + +I think this is it +for today so. \ No newline at end of file diff --git a/HynldX56FHI.txt b/HynldX56FHI.txt new file mode 100644 index 0000000000000000000000000000000000000000..fa2c24363fb5aea3f7be8dada1c4eeaf154d3ddd --- /dev/null +++ b/HynldX56FHI.txt @@ -0,0 +1,1411 @@ +align:start position:0% + +welcome back to 8701 + + align:start position:0% +welcome back to 8701 + + + align:start position:0% +welcome back to 8701 +um so in this second chapter chapter + + align:start position:0% +um so in this second chapter chapter + + + align:start position:0% +um so in this second chapter chapter +number one + + align:start position:0% +number one + + + align:start position:0% +number one +we start talking about quarks and + + align:start position:0% +we start talking about quarks and + + + align:start position:0% +we start talking about quarks and +leptons interactions and fears + + align:start position:0% +leptons interactions and fears + + + align:start position:0% +leptons interactions and fears +and we'll start by very general + + align:start position:0% +and we'll start by very general + + + align:start position:0% +and we'll start by very general +discussion of quantum fields and matter + + align:start position:0% +discussion of quantum fields and matter + + + align:start position:0% +discussion of quantum fields and matter +so you all know that what we mean by + + align:start position:0% +so you all know that what we mean by + + + align:start position:0% +so you all know that what we mean by +particles and forces in a classical + + align:start position:0% +particles and forces in a classical + + + align:start position:0% +particles and forces in a classical +sense + + align:start position:0% +sense + + + align:start position:0% +sense +however we need now to see how they + + align:start position:0% +however we need now to see how they + + + align:start position:0% +however we need now to see how they +connect with quantum fields + + align:start position:0% +connect with quantum fields + + + align:start position:0% +connect with quantum fields +and how this helps us to consider matter + + align:start position:0% +and how this helps us to consider matter + + + align:start position:0% +and how this helps us to consider matter +and forces + + align:start position:0% +and forces + + + align:start position:0% +and forces +in a very similar way + + align:start position:0% +in a very similar way + + + align:start position:0% +in a very similar way +the modern view of the basic way that + + align:start position:0% +the modern view of the basic way that + + + align:start position:0% +the modern view of the basic way that +particles come to exist + + align:start position:0% +particles come to exist + + + align:start position:0% +particles come to exist +is in terms of quantized spheres which + + align:start position:0% +is in terms of quantized spheres which + + + align:start position:0% +is in terms of quantized spheres which +is + + align:start position:0% +is + + + align:start position:0% +is +an extension of the quantum mechanics + + align:start position:0% +an extension of the quantum mechanics + + + align:start position:0% +an extension of the quantum mechanics +you love and know + + align:start position:0% +you love and know + + + align:start position:0% +you love and know +um which you have done before where you + + align:start position:0% +um which you have done before where you + + + align:start position:0% +um which you have done before where you +quantize + + align:start position:0% +quantize + + + align:start position:0% +quantize +particles these fields have quantum + + align:start position:0% +particles these fields have quantum + + + align:start position:0% +particles these fields have quantum +equations + + align:start position:0% +equations + + + align:start position:0% +equations +for the field amplitudes which are + + align:start position:0% +for the field amplitudes which are + + + align:start position:0% +for the field amplitudes which are +basically like + + align:start position:0% +basically like + + + align:start position:0% +basically like +the quantum simple harmonic oscillator + + align:start position:0% +the quantum simple harmonic oscillator + + + align:start position:0% +the quantum simple harmonic oscillator +but there are an infinite number of them + + align:start position:0% +but there are an infinite number of them + + + align:start position:0% +but there are an infinite number of them +one + + align:start position:0% +one + + + align:start position:0% +one +for every possible frequency of wave in + + align:start position:0% +for every possible frequency of wave in + + + align:start position:0% +for every possible frequency of wave in +the field + + align:start position:0% +the field + + + align:start position:0% +the field +this means the amplitudes for the wave + + align:start position:0% +this means the amplitudes for the wave + + + align:start position:0% +this means the amplitudes for the wave +for each frequency are therefore + + align:start position:0% +for each frequency are therefore + + + align:start position:0% +for each frequency are therefore +quantized + + align:start position:0% +quantized + + + align:start position:0% +quantized +in integer steps uh just like + + align:start position:0% +in integer steps uh just like + + + align:start position:0% +in integer steps uh just like +a simple harmonic oscillator this is + + align:start position:0% +a simple harmonic oscillator this is + + + align:start position:0% +a simple harmonic oscillator this is +what we see as a particle the first + + align:start position:0% +what we see as a particle the first + + + align:start position:0% +what we see as a particle the first +excitation gives one particle of a + + align:start position:0% +excitation gives one particle of a + + + align:start position:0% +excitation gives one particle of a +frequency + + align:start position:0% +frequency + + + align:start position:0% +frequency +a further excitation of the amplitude + + align:start position:0% +a further excitation of the amplitude + + + align:start position:0% +a further excitation of the amplitude +for the same frequency corresponds to + + align:start position:0% +for the same frequency corresponds to + + + align:start position:0% +for the same frequency corresponds to +two particles + + align:start position:0% +two particles + + + align:start position:0% +two particles +etc etc so hence the concept of quantum + + align:start position:0% +etc etc so hence the concept of quantum + + + align:start position:0% +etc etc so hence the concept of quantum +field unlike normal quantum mechanics + + align:start position:0% +field unlike normal quantum mechanics + + + align:start position:0% +field unlike normal quantum mechanics +allows an arbitrary + + align:start position:0% +allows an arbitrary + + + align:start position:0% +allows an arbitrary +and changeable number of particles to + + align:start position:0% +and changeable number of particles to + + + align:start position:0% +and changeable number of particles to +exist + + align:start position:0% +exist + + + align:start position:0% +exist +this is necessary as you will see later + + align:start position:0% +this is necessary as you will see later + + + align:start position:0% +this is necessary as you will see later +such that we can create and annihilate + + align:start position:0% +such that we can create and annihilate + + + align:start position:0% +such that we can create and annihilate +part particles + + align:start position:0% +part particles + + + align:start position:0% +part particles +in reactions in the decays + + align:start position:0% +in reactions in the decays + + + align:start position:0% +in reactions in the decays +and the standard wave functions + + align:start position:0% +and the standard wave functions + + + align:start position:0% +and the standard wave functions +correspond to an equation of a + + align:start position:0% +correspond to an equation of a + + + align:start position:0% +correspond to an equation of a +particular frequency + + align:start position:0% +particular frequency + + + align:start position:0% +particular frequency +amplitude when it is exist and existed + + align:start position:0% + + + + align:start position:0% + +so now just let's consider a few cases + + align:start position:0% +so now just let's consider a few cases + + + align:start position:0% +so now just let's consider a few cases +here um + + align:start position:0% +here um + + + align:start position:0% +here um +um imagine you have you know two + + align:start position:0% +um imagine you have you know two + + + align:start position:0% +um imagine you have you know two +particles two fermions for example let's + + align:start position:0% +particles two fermions for example let's + + + align:start position:0% +particles two fermions for example let's +say two electrons + + align:start position:0% +say two electrons + + + align:start position:0% +say two electrons +um and you consider the wave function um + + align:start position:0% +um and you consider the wave function um + + + align:start position:0% +um and you consider the wave function um +quantum field theory um actually says + + align:start position:0% +quantum field theory um actually says + + + align:start position:0% +quantum field theory um actually says +that there's only + + align:start position:0% +that there's only + + + align:start position:0% +that there's only +one electron quantum field for the whole + + align:start position:0% +one electron quantum field for the whole + + + align:start position:0% +one electron quantum field for the whole +universe and every electron + + align:start position:0% +universe and every electron + + + align:start position:0% +universe and every electron +which has this is due to an excitation + + align:start position:0% +which has this is due to an excitation + + + align:start position:0% +which has this is due to an excitation +of the field + + align:start position:0% +of the field + + + align:start position:0% +of the field +and all electrons are identical in a + + align:start position:0% +and all electrons are identical in a + + + align:start position:0% +and all electrons are identical in a +quantum mechanical sense + + align:start position:0% +quantum mechanical sense + + + align:start position:0% +quantum mechanical sense +and they all arise from the same field + + align:start position:0% +and they all arise from the same field + + + align:start position:0% +and they all arise from the same field +now the theory says then that our + + align:start position:0% +now the theory says then that our + + + align:start position:0% +now the theory says then that our +particular properties or the resulting + + align:start position:0% +particular properties or the resulting + + + align:start position:0% +particular properties or the resulting +black equations namely their symmetry + + align:start position:0% +black equations namely their symmetry + + + align:start position:0% +black equations namely their symmetry +under exchange of these particles + + align:start position:0% +under exchange of these particles + + + align:start position:0% +under exchange of these particles +so the actual symmetry um depends on + + align:start position:0% +so the actual symmetry um depends on + + + align:start position:0% +so the actual symmetry um depends on +whether or not the particle is a fermion + + align:start position:0% +whether or not the particle is a fermion + + + align:start position:0% +whether or not the particle is a fermion +which means it has been one half or + + align:start position:0% +which means it has been one half or + + + align:start position:0% +which means it has been one half or +three halves or + + align:start position:0% +three halves or + + + align:start position:0% +three halves or +five halves etc or boson which means + + align:start position:0% +five halves etc or boson which means + + + align:start position:0% +five halves etc or boson which means +that it has been one + + align:start position:0% +that it has been one + + + align:start position:0% +that it has been one +zero one or two and so on so for any + + align:start position:0% +zero one or two and so on so for any + + + align:start position:0% +zero one or two and so on so for any +identical fermion an electron a quantum + + align:start position:0% +identical fermion an electron a quantum + + + align:start position:0% +identical fermion an electron a quantum +field + + align:start position:0% +field + + + align:start position:0% +field +theory says that their wave function + + align:start position:0% +theory says that their wave function + + + align:start position:0% +theory says that their wave function +must invade + + align:start position:0% +must invade + + + align:start position:0% +must invade +the property of anti-symmetry + + align:start position:0% +the property of anti-symmetry + + + align:start position:0% +the property of anti-symmetry +um this means that when we write an + + align:start position:0% +um this means that when we write an + + + align:start position:0% +um this means that when we write an +overall wave function and we replace two + + align:start position:0% +overall wave function and we replace two + + + align:start position:0% +overall wave function and we replace two +particles + + align:start position:0% +particles + + + align:start position:0% +particles +to pick up a minus sign uh this property + + align:start position:0% +to pick up a minus sign uh this property + + + align:start position:0% +to pick up a minus sign uh this property +is just + + align:start position:0% +is just + + + align:start position:0% +is just +not just for for for electrons but for + + align:start position:0% +not just for for for electrons but for + + + align:start position:0% +not just for for for electrons but for +all fermions + + align:start position:0% +all fermions + + + align:start position:0% +all fermions +um that's all metaparticle as the + + align:start position:0% +um that's all metaparticle as the + + + align:start position:0% +um that's all metaparticle as the +smaller shoot + + align:start position:0% +smaller shoot + + + align:start position:0% +smaller shoot +so it also holds for composite particles + + align:start position:0% +so it also holds for composite particles + + + align:start position:0% +so it also holds for composite particles +a composite spin half particle + + align:start position:0% +a composite spin half particle + + + align:start position:0% +a composite spin half particle +um is subject to the same antisymmetry + + align:start position:0% + + + + align:start position:0% + +this probably property of exchange + + align:start position:0% +this probably property of exchange + + + align:start position:0% +this probably property of exchange +antisymmetry leads to a well-known + + align:start position:0% +antisymmetry leads to a well-known + + + align:start position:0% +antisymmetry leads to a well-known +um principle namely the pauli principle + + align:start position:0% +um principle namely the pauli principle + + + align:start position:0% +um principle namely the pauli principle +which means that you cannot have two + + align:start position:0% +which means that you cannot have two + + + align:start position:0% +which means that you cannot have two +electrons of the same + + align:start position:0% +electrons of the same + + + align:start position:0% +electrons of the same +energy state or the same state um + + align:start position:0% +energy state or the same state um + + + align:start position:0% +energy state or the same state um +because when you would actually + + align:start position:0% +because when you would actually + + + align:start position:0% +because when you would actually +swap them you find + + align:start position:0% + + + + align:start position:0% + +that they're identical which means + + align:start position:0% +that they're identical which means + + + align:start position:0% +that they're identical which means +there's dark contrast to the actual + + align:start position:0% +there's dark contrast to the actual + + + align:start position:0% +there's dark contrast to the actual +description of this wave function so + + align:start position:0% +description of this wave function so + + + align:start position:0% +description of this wave function so +this doesn't really work and therefore + + align:start position:0% +this doesn't really work and therefore + + + align:start position:0% +this doesn't really work and therefore +two electrons or two fermions cannot be + + align:start position:0% +two electrons or two fermions cannot be + + + align:start position:0% +two electrons or two fermions cannot be +in the same state + + align:start position:0% +in the same state + + + align:start position:0% +in the same state +in very general constructing a + + align:start position:0% +in very general constructing a + + + align:start position:0% +in very general constructing a +wave function or a total wave equation + + align:start position:0% +wave function or a total wave equation + + + align:start position:0% +wave function or a total wave equation +for two firms is not that hard + + align:start position:0% +for two firms is not that hard + + + align:start position:0% +for two firms is not that hard +you can simply do this by + + align:start position:0% + + + + align:start position:0% + +by this construction + + align:start position:0% + + + + align:start position:0% + +uh important additional statement on + + align:start position:0% +uh important additional statement on + + + align:start position:0% +uh important additional statement on +note to take here is that an + + align:start position:0% +note to take here is that an + + + align:start position:0% +note to take here is that an +anti-particle such as a positron + + align:start position:0% +anti-particle such as a positron + + + align:start position:0% +anti-particle such as a positron +is not identical to a particle um + + align:start position:0% +is not identical to a particle um + + + align:start position:0% +is not identical to a particle um +such that the electron again + + align:start position:0% +such that the electron again + + + align:start position:0% +such that the electron again +if you move on to bosons both on + + align:start position:0% +if you move on to bosons both on + + + align:start position:0% +if you move on to bosons both on +exchange is symmetric + + align:start position:0% +exchange is symmetric + + + align:start position:0% +exchange is symmetric +meaning that you know if you replace two + + align:start position:0% +meaning that you know if you replace two + + + align:start position:0% +meaning that you know if you replace two +bosons defines identical + + align:start position:0% +bosons defines identical + + + align:start position:0% +bosons defines identical +wave function and then constructing a + + align:start position:0% +wave function and then constructing a + + + align:start position:0% +wave function and then constructing a +two boson + + align:start position:0% +two boson + + + align:start position:0% +two boson +uh total wave function you do this by + + align:start position:0% +uh total wave function you do this by + + + align:start position:0% +uh total wave function you do this by +adding those two functions together this + + align:start position:0% +adding those two functions together this + + + align:start position:0% +adding those two functions together this +is by definition + + align:start position:0% +is by definition + + + align:start position:0% +is by definition +the metric let's move now forwards to + + align:start position:0% +the metric let's move now forwards to + + + align:start position:0% +the metric let's move now forwards to +exchange particles again you have a very + + align:start position:0% +exchange particles again you have a very + + + align:start position:0% +exchange particles again you have a very +good idea of the classical picture + + align:start position:0% +good idea of the classical picture + + + align:start position:0% +good idea of the classical picture +how forces are transmitted um so the + + align:start position:0% +how forces are transmitted um so the + + + align:start position:0% +how forces are transmitted um so the +modern picture however + + align:start position:0% +modern picture however + + + align:start position:0% +modern picture however +of how a force acts under conservation + + align:start position:0% +of how a force acts under conservation + + + align:start position:0% +of how a force acts under conservation +is by admission and by absorption of a + + align:start position:0% +is by admission and by absorption of a + + + align:start position:0% +is by admission and by absorption of a +particle + + align:start position:0% +particle + + + align:start position:0% +particle +what is shown in this diagram here where + + align:start position:0% +what is shown in this diagram here where + + + align:start position:0% +what is shown in this diagram here where +you let's say you have an electron and a + + align:start position:0% +you let's say you have an electron and a + + + align:start position:0% +you let's say you have an electron and a +second electron + + align:start position:0% +second electron + + + align:start position:0% +second electron +they see each other and they see each + + align:start position:0% +they see each other and they see each + + + align:start position:0% +they see each other and they see each +other by emitting + + align:start position:0% +other by emitting + + + align:start position:0% +other by emitting +and absorbing photons and you see this + + align:start position:0% +and absorbing photons and you see this + + + align:start position:0% +and absorbing photons and you see this +here so + + align:start position:0% +here so + + + align:start position:0% +here so +this electron comes along maybe emitting + + align:start position:0% +this electron comes along maybe emitting + + + align:start position:0% +this electron comes along maybe emitting +a photon + + align:start position:0% +a photon + + + align:start position:0% +a photon +this electron here emits it and by this + + align:start position:0% +this electron here emits it and by this + + + align:start position:0% +this electron here emits it and by this +exchange of emission + + align:start position:0% +exchange of emission + + + align:start position:0% +exchange of emission +and absorption of photon those two + + align:start position:0% +and absorption of photon those two + + + align:start position:0% +and absorption of photon those two +particles the electrostatic electrons + + align:start position:0% +particles the electrostatic electrons + + + align:start position:0% +particles the electrostatic electrons +see each other + + align:start position:0% +see each other + + + align:start position:0% +see each other +for this you know you can think about + + align:start position:0% +for this you know you can think about + + + align:start position:0% +for this you know you can think about +like you know two ships + + align:start position:0% +like you know two ships + + + align:start position:0% +like you know two ships +shooting cannons if you want but this + + align:start position:0% +shooting cannons if you want but this + + + align:start position:0% +shooting cannons if you want but this +would all um + + align:start position:0% +would all um + + + align:start position:0% +would all um +um but you also have to consider that + + align:start position:0% +um but you also have to consider that + + + align:start position:0% +um but you also have to consider that +there is not just repelling forces but + + align:start position:0% +there is not just repelling forces but + + + align:start position:0% +there is not just repelling forces but +also + + align:start position:0% +also + + + align:start position:0% +also +attracting forces could have replaced + + align:start position:0% +attracting forces could have replaced + + + align:start position:0% +attracting forces could have replaced +the electron with the positron and the + + align:start position:0% +the electron with the positron and the + + + align:start position:0% +the electron with the positron and the +negative + + align:start position:0% +negative + + + align:start position:0% +negative +negative the negative and the positive + + align:start position:0% +negative the negative and the positive + + + align:start position:0% +negative the negative and the positive +charge attracting each other + + align:start position:0% +charge attracting each other + + + align:start position:0% +charge attracting each other +this is it for this uh for this short um + + align:start position:0% + + + + align:start position:0% + +basically an intro into the intro of the + + align:start position:0% +basically an intro into the intro of the + + + align:start position:0% +basically an intro into the intro of the +intro um + + align:start position:0% +intro um + + + align:start position:0% +intro um +i hope you enjoy this all of this + + align:start position:0% +i hope you enjoy this all of this + + + align:start position:0% +i hope you enjoy this all of this +concept we go into more detail + + align:start position:0% +concept we go into more detail + + + align:start position:0% +concept we go into more detail +this is really just the starting point + + align:start position:0% +this is really just the starting point + + + align:start position:0% +this is really just the starting point +um and in the next lecture you'll see + + align:start position:0% +um and in the next lecture you'll see + + + align:start position:0% +um and in the next lecture you'll see +how we can actually understand + + align:start position:0% +how we can actually understand + + + align:start position:0% +how we can actually understand +aspects of this diagram here which we + + align:start position:0% +aspects of this diagram here which we + + + align:start position:0% +aspects of this diagram here which we +call the final diagram + + align:start position:0% +call the final diagram + + + align:start position:0% +call the final diagram +you \ No newline at end of file diff --git a/Hzv9WuqIzA0.txt b/Hzv9WuqIzA0.txt new file mode 100644 index 0000000000000000000000000000000000000000..3307dd135b6e2357c1e9241852b019d457a8d405 --- /dev/null +++ b/Hzv9WuqIzA0.txt @@ -0,0 +1,14547 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT OpenCourseWare continue to + + align:start position:0% +will help MIT OpenCourseWare continue to + + + align:start position:0% +will help MIT OpenCourseWare continue to +offer high quality educational resources + + align:start position:0% +offer high quality educational resources + + + align:start position:0% +offer high quality educational resources +for free + + align:start position:0% +for free + + + align:start position:0% +for free +to make a donation or to view additional + + align:start position:0% +to make a donation or to view additional + + + align:start position:0% +to make a donation or to view additional +materials from hundreds of MIT courses + + align:start position:0% +materials from hundreds of MIT courses + + + align:start position:0% +materials from hundreds of MIT courses +visit MIT opencourseware at ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +okay so today I'll talk about payment + + align:start position:0% +okay so today I'll talk about payment + + + align:start position:0% +okay so today I'll talk about payment +channels and the Lightning Network and I + + align:start position:0% +channels and the Lightning Network and I + + + align:start position:0% +channels and the Lightning Network and I +am sorry if I gloss over things I've + + align:start position:0% +am sorry if I gloss over things I've + + + align:start position:0% +am sorry if I gloss over things I've +explained this like a lot in the last + + align:start position:0% +explained this like a lot in the last + + + align:start position:0% +explained this like a lot in the last +two years because that's sort of my work + + align:start position:0% +two years because that's sort of my work + + + align:start position:0% +two years because that's sort of my work +on so I might like to skip over + + align:start position:0% +on so I might like to skip over + + + align:start position:0% +on so I might like to skip over +something you're like wait how did you + + align:start position:0% +something you're like wait how did you + + + align:start position:0% +something you're like wait how did you +get there so let me know so it'll have + + align:start position:0% +get there so let me know so it'll have + + + align:start position:0% +get there so let me know so it'll have +unidirectional payment channels and then + + align:start position:0% +unidirectional payment channels and then + + + align:start position:0% +unidirectional payment channels and then +lightning channel and then multi-hop + + align:start position:0% +lightning channel and then multi-hop + + + align:start position:0% +lightning channel and then multi-hop +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so the idea of payment channels why do + + align:start position:0% +so the idea of payment channels why do + + + align:start position:0% +so the idea of payment channels why do +we need to do all this complicated weird + + align:start position:0% +we need to do all this complicated weird + + + align:start position:0% +we need to do all this complicated weird +stuff with payment channels well the + + align:start position:0% +stuff with payment channels well the + + + align:start position:0% +stuff with payment channels well the +problem is these networks are really + + align:start position:0% +problem is these networks are really + + + align:start position:0% +problem is these networks are really +poor in scalability right every + + align:start position:0% +poor in scalability right every + + + align:start position:0% +poor in scalability right every +transaction on the blockchain + + align:start position:0% +transaction on the blockchain + + + align:start position:0% +transaction on the blockchain +you know that whole idea doesn't scale + + align:start position:0% +you know that whole idea doesn't scale + + + align:start position:0% +you know that whole idea doesn't scale +it's sort of people say it's o of N + + align:start position:0% +it's sort of people say it's o of N + + + align:start position:0% +it's sort of people say it's o of N +squared depends on what you define as N + + align:start position:0% +squared depends on what you define as N + + + align:start position:0% +squared depends on what you define as N +and things like that right so if you + + align:start position:0% +and things like that right so if you + + + align:start position:0% +and things like that right so if you +double the number of nodes it actually + + align:start position:0% +double the number of nodes it actually + + + align:start position:0% +double the number of nodes it actually +doesn't you can say well if you double + + align:start position:0% +doesn't you can say well if you double + + + align:start position:0% +doesn't you can say well if you double +the number of nodes each node is gonna + + align:start position:0% +the number of nodes each node is gonna + + + align:start position:0% +the number of nodes each node is gonna +be making some transactions right and + + align:start position:0% +be making some transactions right and + + + align:start position:0% +be making some transactions right and +then you're like okay yeah that's N + + align:start position:0% +then you're like okay yeah that's N + + + align:start position:0% +then you're like okay yeah that's N +squared if you count the total number of + + align:start position:0% +squared if you count the total number of + + + align:start position:0% +squared if you count the total number of +computations throughout the entire + + align:start position:0% +computations throughout the entire + + + align:start position:0% +computations throughout the entire +system but at the same time it's like + + align:start position:0% +system but at the same time it's like + + + align:start position:0% +system but at the same time it's like +well you've doubled the number of nodes + + align:start position:0% +well you've doubled the number of nodes + + + align:start position:0% +well you've doubled the number of nodes +so really it's o of n right like for any + + align:start position:0% +so really it's o of n right like for any + + + align:start position:0% +so really it's o of n right like for any +one computer your amount of computation + + align:start position:0% +one computer your amount of computation + + + align:start position:0% +one computer your amount of computation +you have to do scales with how many + + align:start position:0% +you have to do scales with how many + + + align:start position:0% +you have to do scales with how many +other computers that are so it's a + + align:start position:0% +other computers that are so it's a + + + align:start position:0% +other computers that are so it's a +little you know questionable but but + + align:start position:0% +little you know questionable but but + + + align:start position:0% +little you know questionable but but +basically it doesn't scale well right it + + align:start position:0% +basically it doesn't scale well right it + + + align:start position:0% +basically it doesn't scale well right it +doesn't scale to what you want and so I + + align:start position:0% +doesn't scale to what you want and so I + + + align:start position:0% +doesn't scale to what you want and so I +put a little history the first response + + align:start position:0% +put a little history the first response + + + align:start position:0% +put a little history the first response +of anyone ever referring to Bitcoin so + + align:start position:0% +of anyone ever referring to Bitcoin so + + + align:start position:0% +of anyone ever referring to Bitcoin so +there was a 2008 like October 30 + + align:start position:0% +there was a 2008 like October 30 + + + align:start position:0% +there was a 2008 like October 30 +Halloween 2008 or like maybe after + + align:start position:0% +Halloween 2008 or like maybe after + + + align:start position:0% +Halloween 2008 or like maybe after +midnight so November 1st and Satoshi + + align:start position:0% +midnight so November 1st and Satoshi + + + align:start position:0% +midnight so November 1st and Satoshi +wrote I've been working on a new + + align:start position:0% +wrote I've been working on a new + + + align:start position:0% +wrote I've been working on a new +electronic cash system that's fully + + align:start position:0% +electronic cash system that's fully + + + align:start position:0% +electronic cash system that's fully +peer-to-peer with no trusted third party + + align:start position:0% +peer-to-peer with no trusted third party + + + align:start position:0% +peer-to-peer with no trusted third party +he has a little blurb the first reply on + + align:start position:0% +he has a little blurb the first reply on + + + align:start position:0% +he has a little blurb the first reply on +this mailing list was some guy James a + + align:start position:0% +this mailing list was some guy James a + + + align:start position:0% +this mailing list was some guy James a +Donald saying we very very much need + + align:start position:0% +Donald saying we very very much need + + + align:start position:0% +Donald saying we very very much need +such a system the way I understand your + + align:start position:0% +such a system the way I understand your + + + align:start position:0% +such a system the way I understand your +proposal it does not seem to scale to + + align:start position:0% +proposal it does not seem to scale to + + + align:start position:0% +proposal it does not seem to scale to +the required size so that was the first + + align:start position:0% +the required size so that was the first + + + align:start position:0% +the required size so that was the first +thing anyone's ever said about Bitcoin + + align:start position:0% +thing anyone's ever said about Bitcoin + + + align:start position:0% +thing anyone's ever said about Bitcoin +and we're still talking about it almost + + align:start position:0% +and we're still talking about it almost + + + align:start position:0% +and we're still talking about it almost +10 years later + + align:start position:0% +10 years later + + + align:start position:0% +10 years later +I wonder who James Donnell is maybe he's + + align:start position:0% +I wonder who James Donnell is maybe he's + + + align:start position:0% +I wonder who James Donnell is maybe he's +got a ton of Bitcoin now and he you know + + align:start position:0% +got a ton of Bitcoin now and he you know + + + align:start position:0% +got a ton of Bitcoin now and he you know +mined it this was so it was written + + align:start position:0% +mined it this was so it was written + + + align:start position:0% +mined it this was so it was written +about in late 2008 the actual software + + align:start position:0% +about in late 2008 the actual software + + + align:start position:0% +about in late 2008 the actual software +was released in 2009 + + align:start position:0% +was released in 2009 + + + align:start position:0% +was released in 2009 +and no one really there's a couple males + + align:start position:0% +and no one really there's a couple males + + + align:start position:0% +and no one really there's a couple males +no one really looked into it much okay + + align:start position:0% +no one really looked into it much okay + + + align:start position:0% +no one really looked into it much okay +so you can start with a one way payment + + align:start position:0% +so you can start with a one way payment + + + align:start position:0% +so you can start with a one way payment +channel and this was I think Satoshi + + align:start position:0% +channel and this was I think Satoshi + + + align:start position:0% +channel and this was I think Satoshi +sort of mentioned these ideas never + + align:start position:0% +sort of mentioned these ideas never + + + align:start position:0% +sort of mentioned these ideas never +really implemented anything and this the + + align:start position:0% +really implemented anything and this the + + + align:start position:0% +really implemented anything and this the +way he talked about it didn't actually + + align:start position:0% +way he talked about it didn't actually + + + align:start position:0% +way he talked about it didn't actually +work some people in 2012 I remember + + align:start position:0% +work some people in 2012 I remember + + + align:start position:0% +work some people in 2012 I remember +looking at this I think blue mat and + + align:start position:0% +looking at this I think blue mat and + + + align:start position:0% +looking at this I think blue mat and +Mike Hearn gave a talk about like how + + align:start position:0% +Mike Hearn gave a talk about like how + + + align:start position:0% +Mike Hearn gave a talk about like how +you could make payment channels that + + align:start position:0% +you could make payment channels that + + + align:start position:0% +you could make payment channels that +didn't quite work either but the idea + + align:start position:0% +didn't quite work either but the idea + + + align:start position:0% +didn't quite work either but the idea +made sense so the idea is you have some + + align:start position:0% +made sense so the idea is you have some + + + align:start position:0% +made sense so the idea is you have some +kind of shared balance between two + + align:start position:0% +kind of shared balance between two + + + align:start position:0% +kind of shared balance between two +parties and you can move coins in one + + align:start position:0% +parties and you can move coins in one + + + align:start position:0% +parties and you can move coins in one +direction without making new + + align:start position:0% +direction without making new + + + align:start position:0% +direction without making new +transactions on the blockchain + + align:start position:0% +transactions on the blockchain + + + align:start position:0% +transactions on the blockchain +so one thing we haven't looked at but + + align:start position:0% +so one thing we haven't looked at but + + + align:start position:0% +so one thing we haven't looked at but +you might have seen in in the homework + + align:start position:0% + + + + align:start position:0% + +so if you look at like a transaction + + align:start position:0% +so if you look at like a transaction + + + align:start position:0% +so if you look at like a transaction +right probably have seen this kind of + + align:start position:0% +right probably have seen this kind of + + + align:start position:0% +right probably have seen this kind of +thing through the homework it's got a + + align:start position:0% +thing through the homework it's got a + + + align:start position:0% +thing through the homework it's got a +lock time and in this case the lock time + + align:start position:0% +lock time and in this case the lock time + + + align:start position:0% +lock time and in this case the lock time +is zero that means this transaction is + + align:start position:0% +is zero that means this transaction is + + + align:start position:0% +is zero that means this transaction is +valid + + align:start position:0% +valid + + + align:start position:0% +valid +at any point you know above height zero + + align:start position:0% +at any point you know above height zero + + + align:start position:0% +at any point you know above height zero +it's it's valid and every block is above + + align:start position:0% +it's it's valid and every block is above + + + align:start position:0% +it's it's valid and every block is above +height zero you can also find + + align:start position:0% +height zero you can also find + + + align:start position:0% +height zero you can also find +transactions which let's see yeah + + align:start position:0% +transactions which let's see yeah + + + align:start position:0% +transactions which let's see yeah +which has a lock time of this so this + + align:start position:0% +which has a lock time of this so this + + + align:start position:0% +which has a lock time of this so this +looks like a unix time where you you set + + align:start position:0% +looks like a unix time where you you set + + + align:start position:0% +looks like a unix time where you you set +a time this is like a unix time so you + + align:start position:0% +a time this is like a unix time so you + + + align:start position:0% +a time this is like a unix time so you +next time if you don't know it's like a + + align:start position:0% +next time if you don't know it's like a + + + align:start position:0% +next time if you don't know it's like a +30 well its seconds since january 1st + + align:start position:0% +30 well its seconds since january 1st + + + align:start position:0% +30 well its seconds since january 1st +1970 that's sort of like the you know + + align:start position:0% +1970 that's sort of like the you know + + + align:start position:0% +1970 that's sort of like the you know +first second and i don't know that's + + align:start position:0% +first second and i don't know that's + + + align:start position:0% +first second and i don't know that's +probably a week ago or something so you + + align:start position:0% +probably a week ago or something so you + + + align:start position:0% +probably a week ago or something so you +can you can have that filled in a + + align:start position:0% +can you can have that filled in a + + + align:start position:0% +can you can have that filled in a +transaction and the idea is the + + align:start position:0% +transaction and the idea is the + + + align:start position:0% +transaction and the idea is the +transactions only valid after that time + + align:start position:0% +transactions only valid after that time + + + align:start position:0% +transactions only valid after that time +or height it's a little weird below what + + align:start position:0% +or height it's a little weird below what + + + align:start position:0% +or height it's a little weird below what +is it 500 million it counts as a height + + align:start position:0% +is it 500 million it counts as a height + + + align:start position:0% +is it 500 million it counts as a height +above 500 million it counts as a you + + align:start position:0% +above 500 million it counts as a you + + + align:start position:0% +above 500 million it counts as a you +next time which ends up working because + + align:start position:0% +next time which ends up working because + + + align:start position:0% +next time which ends up working because +the idea the UNIX times below 500 + + align:start position:0% +the idea the UNIX times below 500 + + + align:start position:0% +the idea the UNIX times below 500 +million or like in the 80s so you + + align:start position:0% +million or like in the 80s so you + + + align:start position:0% +million or like in the 80s so you +there's no Bitcoin didn't exist then + + align:start position:0% +there's no Bitcoin didn't exist then + + + align:start position:0% +there's no Bitcoin didn't exist then +there's no real need to have time walk + + align:start position:0% +there's no real need to have time walk + + + align:start position:0% +there's no real need to have time walk +think what's her about what five hundred + + align:start position:0% +think what's her about what five hundred + + + align:start position:0% +think what's her about what five hundred +million yeah a couple thousand years so + + align:start position:0% +million yeah a couple thousand years so + + + align:start position:0% +million yeah a couple thousand years so +ya know there's there's way more + + align:start position:0% +ya know there's there's way more + + + align:start position:0% +ya know there's there's way more +problems than Bitcoin before that the + + align:start position:0% +problems than Bitcoin before that the + + + align:start position:0% +problems than Bitcoin before that the +the time field in the headers for bytes + + align:start position:0% +the time field in the headers for bytes + + + align:start position:0% +the time field in the headers for bytes +so either so if it was signed it be 2038 + + align:start position:0% +so either so if it was signed it be 2038 + + + align:start position:0% +so either so if it was signed it be 2038 +that it flips over and goes negative but + + align:start position:0% +that it flips over and goes negative but + + + align:start position:0% +that it flips over and goes negative but +it's unsigned so you got till 2000 106 + + align:start position:0% +it's unsigned so you got till 2000 106 + + + align:start position:0% +it's unsigned so you got till 2000 106 +there's actually a hard fork to fix that + + align:start position:0% +there's actually a hard fork to fix that + + + align:start position:0% +there's actually a hard fork to fix that +but so it you know there's there's all + + align:start position:0% +but so it you know there's there's all + + + align:start position:0% +but so it you know there's there's all +sorts of weird like wait what do we do + + align:start position:0% +sorts of weird like wait what do we do + + + align:start position:0% +sorts of weird like wait what do we do +in the hundreds or thousands of years we + + align:start position:0% +in the hundreds or thousands of years we + + + align:start position:0% +in the hundreds or thousands of years we +have to make these little tweaks which + + align:start position:0% +have to make these little tweaks which + + + align:start position:0% +have to make these little tweaks which +hopefully wouldn't be super + + align:start position:0% +hopefully wouldn't be super + + + align:start position:0% +hopefully wouldn't be super +controversial because it's like well + + align:start position:0% +controversial because it's like well + + + align:start position:0% +controversial because it's like well +it'll stop working unless we change this + + align:start position:0% +it'll stop working unless we change this + + + align:start position:0% +it'll stop working unless we change this +little thing okay so yeah that you can + + align:start position:0% +little thing okay so yeah that you can + + + align:start position:0% +little thing okay so yeah that you can +have these lock times and you can use + + align:start position:0% +have these lock times and you can use + + + align:start position:0% +have these lock times and you can use +those so what you can do is make a + + align:start position:0% +those so what you can do is make a + + + align:start position:0% +those so what you can do is make a +channel and a channel is really just a + + align:start position:0% +channel and a channel is really just a + + + align:start position:0% +channel and a channel is really just a +multi-sig output multi-sig a lot of + + align:start position:0% +multi-sig output multi-sig a lot of + + + align:start position:0% +multi-sig output multi-sig a lot of +times is used for I want to say + + align:start position:0% +times is used for I want to say + + + align:start position:0% +times is used for I want to say +two-factor authentication but you know + + align:start position:0% +two-factor authentication but you know + + + align:start position:0% +two-factor authentication but you know +you could have two of two multi-sig + + align:start position:0% +you could have two of two multi-sig + + + align:start position:0% +you could have two of two multi-sig +where your phone needs to sign and your + + align:start position:0% +where your phone needs to sign and your + + + align:start position:0% +where your phone needs to sign and your +desktop needs to sign and then if + + align:start position:0% +desktop needs to sign and then if + + + align:start position:0% +desktop needs to sign and then if +someone steals your phone or you know + + align:start position:0% +someone steals your phone or you know + + + align:start position:0% +someone steals your phone or you know +hacks your phone and gets the key out + + align:start position:0% +hacks your phone and gets the key out + + + align:start position:0% +hacks your phone and gets the key out +well they have to also get your computer + + align:start position:0% +well they have to also get your computer + + + align:start position:0% +well they have to also get your computer +so this is useful but in these cases + + align:start position:0% +so this is useful but in these cases + + + align:start position:0% +so this is useful but in these cases +it's sort of adversarial multi-sig where + + align:start position:0% +it's sort of adversarial multi-sig where + + + align:start position:0% +it's sort of adversarial multi-sig where +it's not just you and you it's not like + + align:start position:0% +it's not just you and you it's not like + + + align:start position:0% +it's not just you and you it's not like +your phone and your computer it's okay + + align:start position:0% +your phone and your computer it's okay + + + align:start position:0% +your phone and your computer it's okay +it's Alice and Bob they're completely + + align:start position:0% +it's Alice and Bob they're completely + + + align:start position:0% +it's Alice and Bob they're completely +separate people they're not necessarily + + align:start position:0% +separate people they're not necessarily + + + align:start position:0% +separate people they're not necessarily +friends you know it could be customer + + align:start position:0% +friends you know it could be customer + + + align:start position:0% +friends you know it could be customer +merchants kind of thing and they create + + align:start position:0% +merchants kind of thing and they create + + + align:start position:0% +merchants kind of thing and they create +a transaction together so they fund it + + align:start position:0% +a transaction together so they fund it + + + align:start position:0% +a transaction together so they fund it +and Alice is funding this channel and so + + align:start position:0% +and Alice is funding this channel and so + + + align:start position:0% +and Alice is funding this channel and so +she takes her own coins write her own TX + + align:start position:0% +she takes her own coins write her own TX + + + align:start position:0% +she takes her own coins write her own TX +ID index her an output signs it and + + align:start position:0% +ID index her an output signs it and + + + align:start position:0% +ID index her an output signs it and +sends to an allison bob multi-sig and + + align:start position:0% +sends to an allison bob multi-sig and + + + align:start position:0% +sends to an allison bob multi-sig and +sends ten coins so in order to spend + + align:start position:0% +sends ten coins so in order to spend + + + align:start position:0% +sends ten coins so in order to spend +this they both have to cooperate um but + + align:start position:0% +this they both have to cooperate um but + + + align:start position:0% +this they both have to cooperate um but +before doing this Bob gives her a refund + + align:start position:0% +before doing this Bob gives her a refund + + + align:start position:0% +before doing this Bob gives her a refund +transaction so the idea is if Alice just + + align:start position:0% +transaction so the idea is if Alice just + + + align:start position:0% +transaction so the idea is if Alice just +broadcasts to this it says okay I'm + + align:start position:0% +broadcasts to this it says okay I'm + + + align:start position:0% +broadcasts to this it says okay I'm +taking my coins I'm sending it to Alice + + align:start position:0% +taking my coins I'm sending it to Alice + + + align:start position:0% +taking my coins I'm sending it to Alice +and Bob multi-sig Bob can just disappear + + align:start position:0% +and Bob multi-sig Bob can just disappear + + + align:start position:0% +and Bob multi-sig Bob can just disappear +and then Alice is stuck and the money + + align:start position:0% +and then Alice is stuck and the money + + + align:start position:0% +and then Alice is stuck and the money +stuck there forever because Bob + + align:start position:0% +stuck there forever because Bob + + + align:start position:0% +stuck there forever because Bob +never sign or Bob can say Oh Alice looks + + align:start position:0% +never sign or Bob can say Oh Alice looks + + + align:start position:0% +never sign or Bob can say Oh Alice looks +like you sent ten coins how about this + + align:start position:0% +like you sent ten coins how about this + + + align:start position:0% +like you sent ten coins how about this +I'll give you nine of them you just give + + align:start position:0% +I'll give you nine of them you just give + + + align:start position:0% +I'll give you nine of them you just give +me one of them and I don't you know + + align:start position:0% +me one of them and I don't you know + + + align:start position:0% +me one of them and I don't you know +you're not buying anything this is just + + align:start position:0% +you're not buying anything this is just + + + align:start position:0% +you're not buying anything this is just +I'm holding your coins hostage + + align:start position:0% +I'm holding your coins hostage + + + align:start position:0% +I'm holding your coins hostage +Bob could even make a even better threat + + align:start position:0% +Bob could even make a even better threat + + + align:start position:0% +Bob could even make a even better threat +and say I will sign a bunch of time lock + + align:start position:0% +and say I will sign a bunch of time lock + + + align:start position:0% +and say I will sign a bunch of time lock +transactions if you want your money + + align:start position:0% +transactions if you want your money + + + align:start position:0% +transactions if you want your money +today you only get one coin if you want + + align:start position:0% +today you only get one coin if you want + + + align:start position:0% +today you only get one coin if you want +your money in a week you'll get two + + align:start position:0% +your money in a week you'll get two + + + align:start position:0% +your money in a week you'll get two +coins and and you know sign these things + + align:start position:0% +coins and and you know sign these things + + + align:start position:0% +coins and and you know sign these things +with lock times and all the transactions + + align:start position:0% +with lock times and all the transactions + + + align:start position:0% +with lock times and all the transactions +over to Alice and say well you can pick + + align:start position:0% +over to Alice and say well you can pick + + + align:start position:0% +over to Alice and say well you can pick +you know how long do you want to wait to + + align:start position:0% +you know how long do you want to wait to + + + align:start position:0% +you know how long do you want to wait to +get your money back + + align:start position:0% +get your money back + + + align:start position:0% +get your money back +an analysis only response is oh shoot + + align:start position:0% +an analysis only response is oh shoot + + + align:start position:0% +an analysis only response is oh shoot +well if I wait years maybe I'll get most + + align:start position:0% +well if I wait years maybe I'll get most + + + align:start position:0% +well if I wait years maybe I'll get most +of my coins back but if I want my money + + align:start position:0% +of my coins back but if I want my money + + + align:start position:0% +of my coins back but if I want my money +now + + align:start position:0% +now + + + align:start position:0% +now +you know there's there's all sorts of + + align:start position:0% +you know there's there's all sorts of + + + align:start position:0% +you know there's there's all sorts of +horrible hostage situations even if + + align:start position:0% +horrible hostage situations even if + + + align:start position:0% +horrible hostage situations even if +they're both if they both have money at + + align:start position:0% +they're both if they both have money at + + + align:start position:0% +they're both if they both have money at +stake one one person could have less + + align:start position:0% +stake one one person could have less + + + align:start position:0% +stake one one person could have less +time value of money so they're like look + + align:start position:0% +time value of money so they're like look + + + align:start position:0% +time value of money so they're like look +I don't I don't need this anytime soon + + align:start position:0% +I don't I don't need this anytime soon + + + align:start position:0% +I don't I don't need this anytime soon +so I'm willing to wait so this is + + align:start position:0% +so I'm willing to wait so this is + + + align:start position:0% +so I'm willing to wait so this is +dangerous so what they do beforehand is + + align:start position:0% +dangerous so what they do beforehand is + + + align:start position:0% +dangerous so what they do beforehand is +Alice's hey Bob give me a refund + + align:start position:0% +Alice's hey Bob give me a refund + + + align:start position:0% +Alice's hey Bob give me a refund +transaction so Bob signs a refund + + align:start position:0% +transaction so Bob signs a refund + + + align:start position:0% +transaction so Bob signs a refund +transaction with a lock time of one week + + align:start position:0% +transaction with a lock time of one week + + + align:start position:0% +transaction with a lock time of one week +from now March 28th and the input is the + + align:start position:0% +from now March 28th and the input is the + + + align:start position:0% +from now March 28th and the input is the +fund transaction ID even though the fund + + align:start position:0% +fund transaction ID even though the fund + + + align:start position:0% +fund transaction ID even though the fund +transaction ID comes later + + align:start position:0% +transaction ID comes later + + + align:start position:0% +transaction ID comes later +thanks to segue you can say I know what + + align:start position:0% +thanks to segue you can say I know what + + + align:start position:0% +thanks to segue you can say I know what +the TX ID is gonna be I'm gonna you know + + align:start position:0% +the TX ID is gonna be I'm gonna you know + + + align:start position:0% +the TX ID is gonna be I'm gonna you know +reference a spend for that and Bob + + align:start position:0% +reference a spend for that and Bob + + + align:start position:0% +reference a spend for that and Bob +signature is gonna be on there bob signs + + align:start position:0% +signature is gonna be on there bob signs + + + align:start position:0% +signature is gonna be on there bob signs +it hands it over to Alice Alice's + + align:start position:0% +it hands it over to Alice Alice's + + + align:start position:0% +it hands it over to Alice Alice's +doesn't Alice's signatures not there yet + + align:start position:0% +doesn't Alice's signatures not there yet + + + align:start position:0% +doesn't Alice's signatures not there yet +right so Alice can sign it and store it + + align:start position:0% +right so Alice can sign it and store it + + + align:start position:0% +right so Alice can sign it and store it +on her drive or chicken sign later but + + align:start position:0% +on her drive or chicken sign later but + + + align:start position:0% +on her drive or chicken sign later but +until March 28th this transactions not + + align:start position:0% +until March 28th this transactions not + + + align:start position:0% +until March 28th this transactions not +happening right if you try to broadcast + + align:start position:0% +happening right if you try to broadcast + + + align:start position:0% +happening right if you try to broadcast +it everyone will reject it and the + + align:start position:0% +it everyone will reject it and the + + + align:start position:0% +it everyone will reject it and the +output from this refund transaction is + + align:start position:0% +output from this refund transaction is + + + align:start position:0% +output from this refund transaction is +it just sends to Alice's address all 10 + + align:start position:0% +it just sends to Alice's address all 10 + + + align:start position:0% +it just sends to Alice's address all 10 +points yes + + align:start position:0% + + + + align:start position:0% + +Oh how does how do they know the fun its + + align:start position:0% +Oh how does how do they know the fun its + + + align:start position:0% +Oh how does how do they know the fun its +exid Alice can calculate it and tell Bob + + align:start position:0% +exid Alice can calculate it and tell Bob + + + align:start position:0% +exid Alice can calculate it and tell Bob +Alice can say I'm building a fund + + align:start position:0% +Alice can say I'm building a fund + + + align:start position:0% +Alice can say I'm building a fund +transaction Alice knows her inputs she + + align:start position:0% +transaction Alice knows her inputs she + + + align:start position:0% +transaction Alice knows her inputs she +knows she doesn't actually have to sign + + align:start position:0% +knows she doesn't actually have to sign + + + align:start position:0% +knows she doesn't actually have to sign +it all because the TX ID wasn't won't + + align:start position:0% +it all because the TX ID wasn't won't + + + align:start position:0% +it all because the TX ID wasn't won't +contain the signature and those you know + + align:start position:0% +contain the signature and those you know + + + align:start position:0% +contain the signature and those you know +what their key is so Alice can compute + + align:start position:0% +what their key is so Alice can compute + + + align:start position:0% +what their key is so Alice can compute +the TX ID and tell Bob hey sign this you + + align:start position:0% +the TX ID and tell Bob hey sign this you + + + align:start position:0% +the TX ID and tell Bob hey sign this you +know this is what the transactions gonna + + align:start position:0% +know this is what the transactions gonna + + + align:start position:0% +know this is what the transactions gonna +look like + + align:start position:0% +look like + + + align:start position:0% +look like +sign it and Bob right at this point has + + align:start position:0% +sign it and Bob right at this point has + + + align:start position:0% +sign it and Bob right at this point has +no no risk Bob I guess needs to make + + align:start position:0% +no no risk Bob I guess needs to make + + + align:start position:0% +no no risk Bob I guess needs to make +sure that he's not inadvertently signing + + align:start position:0% +sure that he's not inadvertently signing + + + align:start position:0% +sure that he's not inadvertently signing +his own money right so if Alice says hey + + align:start position:0% +his own money right so if Alice says hey + + + align:start position:0% +his own money right so if Alice says hey +here's the TX ID Bob should make sure + + align:start position:0% +here's the TX ID Bob should make sure + + + align:start position:0% +here's the TX ID Bob should make sure +okay this is not my TX ID right but it's + + align:start position:0% +okay this is not my TX ID right but it's + + + align:start position:0% +okay this is not my TX ID right but it's +actually doesn't matter since since he + + align:start position:0% +actually doesn't matter since since he + + + align:start position:0% +actually doesn't matter since since he +sort of commits to Alice's funky here so + + align:start position:0% +sort of commits to Alice's funky here so + + + align:start position:0% +sort of commits to Alice's funky here so +even if you've swapped the TX ID when + + align:start position:0% +even if you've swapped the TX ID when + + + align:start position:0% +even if you've swapped the TX ID when +you sign you're signing off of what to + + align:start position:0% +you sign you're signing off of what to + + + align:start position:0% +you sign you're signing off of what to +you say this is two of two multi-sig so + + align:start position:0% +you say this is two of two multi-sig so + + + align:start position:0% +you say this is two of two multi-sig so +if this was Bob's single key it wouldn't + + align:start position:0% +if this was Bob's single key it wouldn't + + + align:start position:0% +if this was Bob's single key it wouldn't +it wouldn't even work yeah so but so + + align:start position:0% +it wouldn't even work yeah so but so + + + align:start position:0% +it wouldn't even work yeah so but so +Alice sort of has to give some + + align:start position:0% +Alice sort of has to give some + + + align:start position:0% +Alice sort of has to give some +information about Bob signs hands the + + align:start position:0% +information about Bob signs hands the + + + align:start position:0% +information about Bob signs hands the +refund over to Alice then Alice is able + + align:start position:0% +refund over to Alice then Alice is able + + + align:start position:0% +refund over to Alice then Alice is able +to create this fun transaction and now + + align:start position:0% +to create this fun transaction and now + + + align:start position:0% +to create this fun transaction and now +Alice's risk is minimized because she + + align:start position:0% +Alice's risk is minimized because she + + + align:start position:0% +Alice's risk is minimized because she +says okay I'll send this to this channel + + align:start position:0% +says okay I'll send this to this channel + + + align:start position:0% +says okay I'll send this to this channel +and worst case after wait a week right + + align:start position:0% +and worst case after wait a week right + + + align:start position:0% +and worst case after wait a week right +if Bob disappears as soon as I broadcast + + align:start position:0% +if Bob disappears as soon as I broadcast + + + align:start position:0% +if Bob disappears as soon as I broadcast +this + + align:start position:0% +this + + + align:start position:0% +this +well then Bob's gone I can't do anything + + align:start position:0% +well then Bob's gone I can't do anything + + + align:start position:0% +well then Bob's gone I can't do anything +we can't sign but then next week I'll be + + align:start position:0% +we can't sign but then next week I'll be + + + align:start position:0% +we can't sign but then next week I'll be +able to use this transaction and get all + + align:start position:0% +able to use this transaction and get all + + + align:start position:0% +able to use this transaction and get all +my money back yes + + align:start position:0% + + + + align:start position:0% + +yes which which transaction so there's + + align:start position:0% +yes which which transaction so there's + + + align:start position:0% +yes which which transaction so there's +there's the fund and the refund right no + + align:start position:0% +there's the fund and the refund right no + + + align:start position:0% +there's the fund and the refund right no +it needs to be created before the the + + align:start position:0% +it needs to be created before the the + + + align:start position:0% +it needs to be created before the the +fund right so it's not gonna be on the + + align:start position:0% +fund right so it's not gonna be on the + + + align:start position:0% +fund right so it's not gonna be on the +network but Bob creates this first signs + + align:start position:0% +network but Bob creates this first signs + + + align:start position:0% +network but Bob creates this first signs +it and gives it to Alice that way Alice + + align:start position:0% +it and gives it to Alice that way Alice + + + align:start position:0% +it and gives it to Alice that way Alice +knows well I have this that will be + + align:start position:0% +knows well I have this that will be + + + align:start position:0% +knows well I have this that will be +valid in a week and so that means it's + + align:start position:0% +valid in a week and so that means it's + + + align:start position:0% +valid in a week and so that means it's +safe to sign and broadcast this you know + + align:start position:0% +safe to sign and broadcast this you know + + + align:start position:0% +safe to sign and broadcast this you know +it's got Bob's signature and that's what + + align:start position:0% +it's got Bob's signature and that's what + + + align:start position:0% +it's got Bob's signature and that's what +hand you hand over and then Alice can + + align:start position:0% +hand you hand over and then Alice can + + + align:start position:0% +hand you hand over and then Alice can +sign later she can sign it immediately + + align:start position:0% +sign later she can sign it immediately + + + align:start position:0% +sign later she can sign it immediately +on reception and their store it or she + + align:start position:0% +on reception and their store it or she + + + align:start position:0% +on reception and their store it or she +can sign it on March 28th but the idea + + align:start position:0% +can sign it on March 28th but the idea + + + align:start position:0% +can sign it on March 28th but the idea +she's got Bob's signature endorsing this + + align:start position:0% +she's got Bob's signature endorsing this + + + align:start position:0% +she's got Bob's signature endorsing this +and it's not valid yet but she knows + + align:start position:0% +and it's not valid yet but she knows + + + align:start position:0% +and it's not valid yet but she knows +minimized risk right + + align:start position:0% +minimized risk right + + + align:start position:0% +minimized risk right +worst case wait a week okay so then what + + align:start position:0% +worst case wait a week okay so then what + + + align:start position:0% +worst case wait a week okay so then what +can you do with this you can make sort + + align:start position:0% +can you do with this you can make sort + + + align:start position:0% +can you do with this you can make sort +of similar to refund transactions but + + align:start position:0% +of similar to refund transactions but + + + align:start position:0% +of similar to refund transactions but +they give Bob more money so you make two + + align:start position:0% +they give Bob more money so you make two + + + align:start position:0% +they give Bob more money so you make two +outputs you say okay it's I'm spending + + align:start position:0% +outputs you say okay it's I'm spending + + + align:start position:0% +outputs you say okay it's I'm spending +the fun transaction ID I put Alice's + + align:start position:0% +the fun transaction ID I put Alice's + + + align:start position:0% +the fun transaction ID I put Alice's +signature and I say Alice gets nine + + align:start position:0% +signature and I say Alice gets nine + + + align:start position:0% +signature and I say Alice gets nine +coins Bob gets one coin and Alice hands + + align:start position:0% +coins Bob gets one coin and Alice hands + + + align:start position:0% +coins Bob gets one coin and Alice hands +that over to Bob right so you make a + + align:start position:0% +that over to Bob right so you make a + + + align:start position:0% +that over to Bob right so you make a +transaction like that right it spends + + align:start position:0% +transaction like that right it spends + + + align:start position:0% +transaction like that right it spends +the fun transaction output Alice and + + align:start position:0% +the fun transaction output Alice and + + + align:start position:0% +the fun transaction output Alice and +Bob's he is but are both needed and + + align:start position:0% +Bob's he is but are both needed and + + + align:start position:0% +Bob's he is but are both needed and +Alice signs this and says okay I get + + align:start position:0% +Alice signs this and says okay I get + + + align:start position:0% +Alice signs this and says okay I get +nine you get one hands it over to Bob + + align:start position:0% +nine you get one hands it over to Bob + + + align:start position:0% +nine you get one hands it over to Bob +and Bob says basically I just got the + + align:start position:0% +and Bob says basically I just got the + + + align:start position:0% +and Bob says basically I just got the +money + + align:start position:0% +money + + + align:start position:0% +money +I can broadcast this if I want right + + align:start position:0% +I can broadcast this if I want right + + + align:start position:0% +I can broadcast this if I want right +Bob's got Alice's signature Bob can add + + align:start position:0% +Bob's got Alice's signature Bob can add + + + align:start position:0% +Bob's got Alice's signature Bob can add +his signature broadcast this transaction + + align:start position:0% +his signature broadcast this transaction + + + align:start position:0% +his signature broadcast this transaction +and receive one Bitcoin okay but see Bob + + align:start position:0% +and receive one Bitcoin okay but see Bob + + + align:start position:0% +and receive one Bitcoin okay but see Bob +doesn't sign his side in broadcast Bob + + align:start position:0% +doesn't sign his side in broadcast Bob + + + align:start position:0% +doesn't sign his side in broadcast Bob +just waits Bob's like cool I've got this + + align:start position:0% +just waits Bob's like cool I've got this + + + align:start position:0% +just waits Bob's like cool I've got this +coin I'm not even gonna sign and + + align:start position:0% +coin I'm not even gonna sign and + + + align:start position:0% +coin I'm not even gonna sign and +broadcast this + + align:start position:0% +broadcast this + + + align:start position:0% +broadcast this +I know it's as good as having received + + align:start position:0% +I know it's as good as having received + + + align:start position:0% +I know it's as good as having received +the actual coin because there's no + + align:start position:0% +the actual coin because there's no + + + align:start position:0% +the actual coin because there's no +there's + + align:start position:0% +there's + + + align:start position:0% +there's +thing else Alice can do on her own right + + align:start position:0% +thing else Alice can do on her own right + + + align:start position:0% +thing else Alice can do on her own right +she can't take these ten coins she can + + align:start position:0% +she can't take these ten coins she can + + + align:start position:0% +she can't take these ten coins she can +eventually get the refund in a week but + + align:start position:0% +eventually get the refund in a week but + + + align:start position:0% +eventually get the refund in a week but +for now + + align:start position:0% +for now + + + align:start position:0% +for now +Bob's safe and then maybe a day later + + align:start position:0% +Bob's safe and then maybe a day later + + + align:start position:0% +Bob's safe and then maybe a day later +Alice says okay + + align:start position:0% +Alice says okay + + + align:start position:0% +Alice says okay +I'm giving you another coin right I'm + + align:start position:0% +I'm giving you another coin right I'm + + + align:start position:0% +I'm giving you another coin right I'm +what I'm doing is I'm signing a new + + align:start position:0% +what I'm doing is I'm signing a new + + + align:start position:0% +what I'm doing is I'm signing a new +transaction it spends the same output + + align:start position:0% +transaction it spends the same output + + + align:start position:0% +transaction it spends the same output +this is still you know this is still + + align:start position:0% +this is still you know this is still + + + align:start position:0% +this is still you know this is still +there these have not been broadcast but + + align:start position:0% +there these have not been broadcast but + + + align:start position:0% +there these have not been broadcast but +in this one + + align:start position:0% +in this one + + + align:start position:0% +in this one +Alice gets eight coins Bob gets two + + align:start position:0% +Alice gets eight coins Bob gets two + + + align:start position:0% +Alice gets eight coins Bob gets two +coins Alice signs it hands that over to + + align:start position:0% +coins Alice signs it hands that over to + + + align:start position:0% +coins Alice signs it hands that over to +Bob bobs like great I got another coin I + + align:start position:0% +Bob bobs like great I got another coin I + + + align:start position:0% +Bob bobs like great I got another coin I +will also just wait Bob can actually + + align:start position:0% +will also just wait Bob can actually + + + align:start position:0% +will also just wait Bob can actually +delete this because well this is better + + align:start position:0% +delete this because well this is better + + + align:start position:0% +delete this because well this is better +right for from Bob's perspective I'd + + align:start position:0% +right for from Bob's perspective I'd + + + align:start position:0% +right for from Bob's perspective I'd +rather have two then one and there's no + + align:start position:0% +rather have two then one and there's no + + + align:start position:0% +rather have two then one and there's no +any of them are valid right according to + + align:start position:0% +any of them are valid right according to + + + align:start position:0% +any of them are valid right according to +the network the network itself no one's + + align:start position:0% +the network the network itself no one's + + + align:start position:0% +the network the network itself no one's +seen these things they're not broadcast + + align:start position:0% +seen these things they're not broadcast + + + align:start position:0% +seen these things they're not broadcast +only this exists as an output and you + + align:start position:0% +only this exists as an output and you + + + align:start position:0% +only this exists as an output and you +can keep doing this right you keep doing + + align:start position:0% +can keep doing this right you keep doing + + + align:start position:0% +can keep doing this right you keep doing +this as many times as you want well + + align:start position:0% +this as many times as you want well + + + align:start position:0% +this as many times as you want well +within limits right what what's the + + align:start position:0% +within limits right what what's the + + + align:start position:0% +within limits right what what's the +obvious limit here yeah sure + + align:start position:0% +obvious limit here yeah sure + + + align:start position:0% +obvious limit here yeah sure +once once once Bob gets all ten there's + + align:start position:0% +once once once Bob gets all ten there's + + + align:start position:0% +once once once Bob gets all ten there's +no reason to keep it open anymore also + + align:start position:0% +no reason to keep it open anymore also + + + align:start position:0% +no reason to keep it open anymore also +you can't you can't reverse right if you + + align:start position:0% +you can't you can't reverse right if you + + + align:start position:0% +you can't you can't reverse right if you +try if Alice says oh well so Alice Alice + + align:start position:0% +try if Alice says oh well so Alice Alice + + + align:start position:0% +try if Alice says oh well so Alice Alice +always sort of sending money if Bob says + + align:start position:0% +always sort of sending money if Bob says + + + align:start position:0% +always sort of sending money if Bob says +hey I'm gonna give you some money back + + align:start position:0% +hey I'm gonna give you some money back + + + align:start position:0% +hey I'm gonna give you some money back +and Bob signs something say hey no I + + align:start position:0% +and Bob signs something say hey no I + + + align:start position:0% +and Bob signs something say hey no I +have two coins and you have eight coins + + align:start position:0% +have two coins and you have eight coins + + + align:start position:0% +have two coins and you have eight coins +I was like yeah but you have this right + + align:start position:0% +I was like yeah but you have this right + + + align:start position:0% +I was like yeah but you have this right +you have this you out you know Alice + + align:start position:0% +you have this you out you know Alice + + + align:start position:0% +you have this you out you know Alice +seven Bob three transaction I know you + + align:start position:0% +seven Bob three transaction I know you + + + align:start position:0% +seven Bob three transaction I know you +can broadcast that whenever you want so + + align:start position:0% +can broadcast that whenever you want so + + + align:start position:0% +can broadcast that whenever you want so +there's no credible way for Bob to say + + align:start position:0% +there's no credible way for Bob to say + + + align:start position:0% +there's no credible way for Bob to say +like oh I'm giving you the money back in + + align:start position:0% +like oh I'm giving you the money back in + + + align:start position:0% +like oh I'm giving you the money back in +this channel right yes she gave one two + + align:start position:0% +this channel right yes she gave one two + + + align:start position:0% +this channel right yes she gave one two +and three + + align:start position:0% +and three + + + align:start position:0% +and three +and the next one she gets about 2.5 and + + align:start position:0% +and the next one she gets about 2.5 and + + + align:start position:0% +and the next one she gets about 2.5 and +yeah Bob Bob wouldn't bob would just + + align:start position:0% +yeah Bob Bob wouldn't bob would just + + + align:start position:0% +yeah Bob Bob wouldn't bob would just +ignore it right Bob would be like yeah + + align:start position:0% +ignore it right Bob would be like yeah + + + align:start position:0% +ignore it right Bob would be like yeah +but I already have three why would I + + align:start position:0% +but I already have three why would I + + + align:start position:0% +but I already have three why would I +want two and a half right like and and + + align:start position:0% +want two and a half right like and and + + + align:start position:0% +want two and a half right like and and +it's it's more like in that case if + + align:start position:0% +it's it's more like in that case if + + + align:start position:0% +it's it's more like in that case if +Alice says oh I have to you know Alice + + align:start position:0% +Alice says oh I have to you know Alice + + + align:start position:0% +Alice says oh I have to you know Alice +is trying to take some money back + + align:start position:0% +is trying to take some money back + + + align:start position:0% +is trying to take some money back +essentially Bob is paying Alice in that + + align:start position:0% +essentially Bob is paying Alice in that + + + align:start position:0% +essentially Bob is paying Alice in that +case but it's not credible right alice + + align:start position:0% +case but it's not credible right alice + + + align:start position:0% +case but it's not credible right alice +is like yeah I can sign this again or I + + align:start position:0% +is like yeah I can sign this again or I + + + align:start position:0% +is like yeah I can sign this again or I +can sign I have all ten again but you + + align:start position:0% +can sign I have all ten again but you + + + align:start position:0% +can sign I have all ten again but you +know Bob's idea is like I'm just gonna + + align:start position:0% +know Bob's idea is like I'm just gonna + + + align:start position:0% +know Bob's idea is like I'm just gonna +sign the one where I get the most money + + align:start position:0% +sign the one where I get the most money + + + align:start position:0% +sign the one where I get the most money +so so that's you know that's a + + align:start position:0% +so so that's you know that's a + + + align:start position:0% +so so that's you know that's a +limitation that's it's one direction + + align:start position:0% +limitation that's it's one direction + + + align:start position:0% +limitation that's it's one direction +right you Alice can keep paying Bob Bob + + align:start position:0% +right you Alice can keep paying Bob Bob + + + align:start position:0% +right you Alice can keep paying Bob Bob +can't pay back but that's still pretty + + align:start position:0% +can't pay back but that's still pretty + + + align:start position:0% +can't pay back but that's still pretty +useful in some cases if you're have some + + align:start position:0% +useful in some cases if you're have some + + + align:start position:0% +useful in some cases if you're have some +kind of recurrent payment you're + + align:start position:0% +kind of recurrent payment you're + + + align:start position:0% +kind of recurrent payment you're +streaming videos or something you open a + + align:start position:0% +streaming videos or something you open a + + + align:start position:0% +streaming videos or something you open a +channel you can keep paying one thing + + align:start position:0% +channel you can keep paying one thing + + + align:start position:0% +channel you can keep paying one thing +that's nice is these can be really fast + + align:start position:0% +that's nice is these can be really fast + + + align:start position:0% +that's nice is these can be really fast +so this you have to actually wait till + + align:start position:0% +so this you have to actually wait till + + + align:start position:0% +so this you have to actually wait till +it's in the blockchain but these + + align:start position:0% +it's in the blockchain but these + + + align:start position:0% +it's in the blockchain but these +transactions there's no blockchain + + align:start position:0% +transactions there's no blockchain + + + align:start position:0% +transactions there's no blockchain +involved you just sign it and hand it + + align:start position:0% +involved you just sign it and hand it + + + align:start position:0% +involved you just sign it and hand it +over to the other party and as soon as + + align:start position:0% +over to the other party and as soon as + + + align:start position:0% +over to the other party and as soon as +they've received it they're like it I + + align:start position:0% +they've received it they're like it I + + + align:start position:0% +they've received it they're like it I +got the money so this can be very low + + align:start position:0% +got the money so this can be very low + + + align:start position:0% +got the money so this can be very low +latency so this is pretty cool there are + + align:start position:0% +latency so this is pretty cool there are + + + align:start position:0% +latency so this is pretty cool there are +limitations right anyway so yeah Bob + + align:start position:0% +limitations right anyway so yeah Bob + + + align:start position:0% +limitations right anyway so yeah Bob +keeps getting these half signed + + align:start position:0% +keeps getting these half signed + + + align:start position:0% +keeps getting these half signed +transactions with more and more money + + align:start position:0% +transactions with more and more money + + + align:start position:0% +transactions with more and more money +going to him + + align:start position:0% +going to him + + + align:start position:0% +going to him +the old ones are useless right why would + + align:start position:0% +the old ones are useless right why would + + + align:start position:0% +the old ones are useless right why would +I keep this old transaction where I got + + align:start position:0% +I keep this old transaction where I got + + + align:start position:0% +I keep this old transaction where I got +one coin just delete it so Bob only + + align:start position:0% +one coin just delete it so Bob only + + + align:start position:0% +one coin just delete it so Bob only +actually has to store one thing Bob also + + align:start position:0% +actually has to store one thing Bob also + + + align:start position:0% +actually has to store one thing Bob also +has to be very careful though he's got a + + align:start position:0% +has to be very careful though he's got a + + + align:start position:0% +has to be very careful though he's got a +sign and broadcast one of these before + + align:start position:0% +sign and broadcast one of these before + + + align:start position:0% +sign and broadcast one of these before +next week if he doesn't + + align:start position:0% +next week if he doesn't + + + align:start position:0% +next week if he doesn't +Alice can just broadcast the refund + + align:start position:0% +Alice can just broadcast the refund + + + align:start position:0% +Alice can just broadcast the refund +transaction and you know he thinks he's + + align:start position:0% +transaction and you know he thinks he's + + + align:start position:0% +transaction and you know he thinks he's +getting three coins but Alice's like no + + align:start position:0% +getting three coins but Alice's like no + + + align:start position:0% +getting three coins but Alice's like no +I'm just taking all ten back and I was + + align:start position:0% +I'm just taking all ten back and I was + + + align:start position:0% +I'm just taking all ten back and I was +like shoot I just you know got ripped + + align:start position:0% +like shoot I just you know got ripped + + + align:start position:0% +like shoot I just you know got ripped +off and so you know from the network's + + align:start position:0% +off and so you know from the network's + + + align:start position:0% +off and so you know from the network's +point of view the Bitcoin networks point + + align:start position:0% +point of view the Bitcoin networks point + + + align:start position:0% +point of view the Bitcoin networks point +of view they no-one's seen any of this + + align:start position:0% +of view they no-one's seen any of this + + + align:start position:0% +of view they no-one's seen any of this +right all they see is the fun + + align:start position:0% +right all they see is the fun + + + align:start position:0% +right all they see is the fun +transaction nothing happens for days and + + align:start position:0% +transaction nothing happens for days and + + + align:start position:0% +transaction nothing happens for days and +then they see one of these payment + + align:start position:0% +then they see one of these payment + + + align:start position:0% +then they see one of these payment +channel closing transactions and they + + align:start position:0% +channel closing transactions and they + + + align:start position:0% +channel closing transactions and they +might see multiple right Bob could + + align:start position:0% +might see multiple right Bob could + + + align:start position:0% +might see multiple right Bob could +broadcast all three it would be dumb Bob + + align:start position:0% +broadcast all three it would be dumb Bob + + + align:start position:0% +broadcast all three it would be dumb Bob +Bob willing wants this one but you know + + align:start position:0% +Bob willing wants this one but you know + + + align:start position:0% +Bob willing wants this one but you know +you're basically using double spends to + + align:start position:0% +you're basically using double spends to + + + align:start position:0% +you're basically using double spends to +create these channels okay so yes + + align:start position:0% + + + + align:start position:0% + +yeah you if it happens that means either + + align:start position:0% +yeah you if it happens that means either + + + align:start position:0% +yeah you if it happens that means either +Bob went down or Bob never you know like + + align:start position:0% +Bob went down or Bob never you know like + + + align:start position:0% +Bob went down or Bob never you know like +it's all it's it should never use it in + + align:start position:0% +it's all it's it should never use it in + + + align:start position:0% +it's all it's it should never use it in +real life right it's insurance so that + + align:start position:0% +real life right it's insurance so that + + + align:start position:0% +real life right it's insurance so that +you you're not you're not worried that + + align:start position:0% +you you're not you're not worried that + + + align:start position:0% +you you're not you're not worried that +Bob's just gonna run off and get your + + align:start position:0% +Bob's just gonna run off and get your + + + align:start position:0% +Bob's just gonna run off and get your +phone right but you can't keep using the + + align:start position:0% +phone right but you can't keep using the + + + align:start position:0% +phone right but you can't keep using the +chin like like at that point there's so + + align:start position:0% +chin like like at that point there's so + + + align:start position:0% +chin like like at that point there's so +much trust involved right if you keep + + align:start position:0% +much trust involved right if you keep + + + align:start position:0% +much trust involved right if you keep +trying to use the channel after the + + align:start position:0% +trying to use the channel after the + + + align:start position:0% +trying to use the channel after the +weeks gone by Bob now see like it's the + + align:start position:0% +weeks gone by Bob now see like it's the + + + align:start position:0% +weeks gone by Bob now see like it's the +same reason you can't make it + + align:start position:0% +same reason you can't make it + + + align:start position:0% +same reason you can't make it +bi-directional right if Bob says hey + + align:start position:0% +bi-directional right if Bob says hey + + + align:start position:0% +bi-directional right if Bob says hey +here's a transaction where you get more + + align:start position:0% +here's a transaction where you get more + + + align:start position:0% +here's a transaction where you get more +more of the money Alice's like yeah but + + align:start position:0% +more of the money Alice's like yeah but + + + align:start position:0% +more of the money Alice's like yeah but +that's not that's not credible right + + align:start position:0% +that's not that's not credible right + + + align:start position:0% +that's not that's not credible right +because I know you can broadcast and + + align:start position:0% +because I know you can broadcast and + + + align:start position:0% +because I know you can broadcast and +take more and similarly if Alice says + + align:start position:0% +take more and similarly if Alice says + + + align:start position:0% +take more and similarly if Alice says +let's just keep the channel open Bob's + + align:start position:0% +let's just keep the channel open Bob's + + + align:start position:0% +let's just keep the channel open Bob's +like no that's not credible right like I + + align:start position:0% +like no that's not credible right like I + + + align:start position:0% +like no that's not credible right like I +know you can just take all the money at + + align:start position:0% +know you can just take all the money at + + + align:start position:0% +know you can just take all the money at +any time so you handing me these new + + align:start position:0% +any time so you handing me these new + + + align:start position:0% +any time so you handing me these new +signatures like it's it's sort of + + align:start position:0% +signatures like it's it's sort of + + + align:start position:0% +signatures like it's it's sort of +meaningless it's not like there's so + + align:start position:0% +meaningless it's not like there's so + + + align:start position:0% +meaningless it's not like there's so +much trust involved it like why bother + + align:start position:0% +much trust involved it like why bother + + + align:start position:0% +much trust involved it like why bother +with this whole payment channel thing + + align:start position:0% +with this whole payment channel thing + + + align:start position:0% +with this whole payment channel thing +right so this this is nice in that you + + align:start position:0% +right so this this is nice in that you + + + align:start position:0% +right so this this is nice in that you +don't have to trust the counterparties + + align:start position:0% +don't have to trust the counterparties + + + align:start position:0% +don't have to trust the counterparties +the worst they can do is disappear they + + align:start position:0% +the worst they can do is disappear they + + + align:start position:0% +the worst they can do is disappear they +can't I mean yeah they can hurt + + align:start position:0% +can't I mean yeah they can hurt + + + align:start position:0% +can't I mean yeah they can hurt +themselves right Bob can broadcast this + + align:start position:0% +themselves right Bob can broadcast this + + + align:start position:0% +themselves right Bob can broadcast this +after this exists and now this is like + + align:start position:0% +after this exists and now this is like + + + align:start position:0% +after this exists and now this is like +okay that was dumb thanks for the two + + align:start position:0% +okay that was dumb thanks for the two + + + align:start position:0% +okay that was dumb thanks for the two +coins back or Bob can just disappear and + + align:start position:0% +coins back or Bob can just disappear and + + + align:start position:0% +coins back or Bob can just disappear and +now it's like hey I'm gonna do the + + align:start position:0% +now it's like hey I'm gonna do the + + + align:start position:0% +now it's like hey I'm gonna do the +refund like I know I'm you know you're + + align:start position:0% +refund like I know I'm you know you're + + + align:start position:0% +refund like I know I'm you know you're +supposed to get these three coins but + + align:start position:0% +supposed to get these three coins but + + + align:start position:0% +supposed to get these three coins but +you're gone and the refunds my only + + align:start position:0% +you're gone and the refunds my only + + + align:start position:0% +you're gone and the refunds my only +option so I'm broadcasting it so you + + align:start position:0% +option so I'm broadcasting it so you + + + align:start position:0% +option so I'm broadcasting it so you +don't have to worry about who is your + + align:start position:0% +don't have to worry about who is your + + + align:start position:0% +don't have to worry about who is your +counterparty and you don't have any like + + align:start position:0% +counterparty and you don't have any like + + + align:start position:0% +counterparty and you don't have any like +debt + + align:start position:0% +debt + + + align:start position:0% +debt +there's no custody or anything like that + + align:start position:0% +there's no custody or anything like that + + + align:start position:0% +there's no custody or anything like that +so that's really nice if you if you you + + align:start position:0% +so that's really nice if you if you you + + + align:start position:0% +so that's really nice if you if you you +can add trust but we already have that + + align:start position:0% +can add trust but we already have that + + + align:start position:0% +can add trust but we already have that +with like coinbase in the gemenon you + + align:start position:0% +with like coinbase in the gemenon you + + + align:start position:0% +with like coinbase in the gemenon you +know the exchanges okay so this is + + align:start position:0% +know the exchanges okay so this is + + + align:start position:0% +know the exchanges okay so this is +pretty useful time limits limits on you + + align:start position:0% +pretty useful time limits limits on you + + + align:start position:0% +pretty useful time limits limits on you +know back and forth refund transactions + + align:start position:0% +know back and forth refund transactions + + + align:start position:0% +know back and forth refund transactions +you have to be built before the trend + + align:start position:0% +you have to be built before the trend + + + align:start position:0% +you have to be built before the trend +the fun transaction because and so + + align:start position:0% +the fun transaction because and so + + + align:start position:0% +the fun transaction because and so +malleability hurts that right before seg + + align:start position:0% +malleability hurts that right before seg + + + align:start position:0% +malleability hurts that right before seg +wit this was very risky slushy couldn't + + align:start position:0% +wit this was very risky slushy couldn't + + + align:start position:0% +wit this was very risky slushy couldn't +do it + + align:start position:0% +do it + + + align:start position:0% +do it +the refund transaction has to spend the + + align:start position:0% +the refund transaction has to spend the + + + align:start position:0% +the refund transaction has to spend the +fun transaction and you don't really + + align:start position:0% +fun transaction and you don't really + + + align:start position:0% +fun transaction and you don't really +know without segue you don't know what + + align:start position:0% +know without segue you don't know what + + + align:start position:0% +know without segue you don't know what +that transaction ladies gonna be before + + align:start position:0% +that transaction ladies gonna be before + + + align:start position:0% +that transaction ladies gonna be before +it gets brought it gets confirmed and so + + align:start position:0% +it gets brought it gets confirmed and so + + + align:start position:0% +it gets brought it gets confirmed and so +you could try to anticipate oh well + + align:start position:0% +you could try to anticipate oh well + + + align:start position:0% +you could try to anticipate oh well +there might it might get Molly ated to + + align:start position:0% +there might it might get Molly ated to + + + align:start position:0% +there might it might get Molly ated to +these five different things let's do it + + align:start position:0% + + + + align:start position:0% + +but it's risky right so so let's segue + + align:start position:0% +but it's risky right so so let's segue + + + align:start position:0% +but it's risky right so so let's segue +it's nice you know what to worry about + + align:start position:0% +it's nice you know what to worry about + + + align:start position:0% +it's nice you know what to worry about +okay so any questions about the sort of + + align:start position:0% +okay so any questions about the sort of + + + align:start position:0% +okay so any questions about the sort of +simple + + align:start position:0% +simple + + + align:start position:0% +simple +One Direction payments makes sense okay + + align:start position:0% +One Direction payments makes sense okay + + + align:start position:0% +One Direction payments makes sense okay +so how can you make it even better + + align:start position:0% +so how can you make it even better + + + align:start position:0% +so how can you make it even better +what if you want to make it + + align:start position:0% +what if you want to make it + + + align:start position:0% +what if you want to make it +bi-directional and last forever that + + align:start position:0% +bi-directional and last forever that + + + align:start position:0% +bi-directional and last forever that +would be much more useful right but like + + align:start position:0% +would be much more useful right but like + + + align:start position:0% +would be much more useful right but like +it's a tricky problem the refund + + align:start position:0% +it's a tricky problem the refund + + + align:start position:0% +it's a tricky problem the refund +transactions there and the clock's + + align:start position:0% +transactions there and the clock's + + + align:start position:0% +transactions there and the clock's +ticking also how do you delete or revoke + + align:start position:0% +ticking also how do you delete or revoke + + + align:start position:0% +ticking also how do you delete or revoke +these old transaction right if you've + + align:start position:0% +these old transaction right if you've + + + align:start position:0% +these old transaction right if you've +signed over okay you've got eight coins + + align:start position:0% +signed over okay you've got eight coins + + + align:start position:0% +signed over okay you've got eight coins +I've got two coins that's there forever + + align:start position:0% +I've got two coins that's there forever + + + align:start position:0% +I've got two coins that's there forever +and the blockchain doesn't know that + + align:start position:0% +and the blockchain doesn't know that + + + align:start position:0% +and the blockchain doesn't know that +it's not valid anymore right the whole + + align:start position:0% +it's not valid anymore right the whole + + + align:start position:0% +it's not valid anymore right the whole +point of the blockchain is to say okay + + align:start position:0% +point of the blockchain is to say okay + + + align:start position:0% +point of the blockchain is to say okay +this is gone actually but between this + + align:start position:0% +this is gone actually but between this + + + align:start position:0% +this is gone actually but between this +unidirectional and lightning I think how + + align:start position:0% +unidirectional and lightning I think how + + + align:start position:0% +unidirectional and lightning I think how +did the order go like christian decker + + align:start position:0% +did the order go like christian decker + + + align:start position:0% +did the order go like christian decker +wrote a thing about decrementing time + + align:start position:0% +wrote a thing about decrementing time + + + align:start position:0% +wrote a thing about decrementing time +locks and i don't think he published I + + align:start position:0% +locks and i don't think he published I + + + align:start position:0% +locks and i don't think he published I +think he published after we wrote + + align:start position:0% +think he published after we wrote + + + align:start position:0% +think he published after we wrote +lightning but the idea was like these + + align:start position:0% +lightning but the idea was like these + + + align:start position:0% +lightning but the idea was like these +would have lock times it's like you + + align:start position:0% +would have lock times it's like you + + + align:start position:0% +would have lock times it's like you +could broadcast this you could broadcast + + align:start position:0% +could broadcast this you could broadcast + + + align:start position:0% +could broadcast this you could broadcast +this on the 27th right all the three of + + align:start position:0% +this on the 27th right all the three of + + + align:start position:0% +this on the 27th right all the three of +these could be broadcast on the 27th and + + align:start position:0% +these could be broadcast on the 27th and + + + align:start position:0% +these could be broadcast on the 27th and +then the idea is Bob wants to send money + + align:start position:0% +then the idea is Bob wants to send money + + + align:start position:0% +then the idea is Bob wants to send money +back and you put a lock time on the 26th + + align:start position:0% +back and you put a lock time on the 26th + + + align:start position:0% +back and you put a lock time on the 26th +and the idea is like oh now now there's + + align:start position:0% +and the idea is like oh now now there's + + + align:start position:0% +and the idea is like oh now now there's +these all are 27th but now there's a bob + + align:start position:0% +these all are 27th but now there's a bob + + + align:start position:0% +these all are 27th but now there's a bob +to alice 8 over here that's broadcast on + + align:start position:0% +to alice 8 over here that's broadcast on + + + align:start position:0% +to alice 8 over here that's broadcast on +the 26th and so the idea is well Alice + + align:start position:0% +the 26th and so the idea is well Alice + + + align:start position:0% +the 26th and so the idea is well Alice +can get the money back you know Alice + + align:start position:0% +can get the money back you know Alice + + + align:start position:0% +can get the money back you know Alice +Bob can pay and go back to paying Alice + + align:start position:0% +Bob can pay and go back to paying Alice + + + align:start position:0% +Bob can pay and go back to paying Alice +because it's like sooner and now it's + + align:start position:0% +because it's like sooner and now it's + + + align:start position:0% +because it's like sooner and now it's +gonna like race so that helps a little + + align:start position:0% +gonna like race so that helps a little + + + align:start position:0% +gonna like race so that helps a little +and that you can switch back and forth a + + align:start position:0% +and that you can switch back and forth a + + + align:start position:0% +and that you can switch back and forth a +few times but each time you do it the + + align:start position:0% +few times but each time you do it the + + + align:start position:0% +few times but each time you do it the +time window gets like sooner so that's + + align:start position:0% +time window gets like sooner so that's + + + align:start position:0% +time window gets like sooner so that's +kind of cool idea + + align:start position:0% +kind of cool idea + + + align:start position:0% +kind of cool idea +but I think the Lightning one is nicer + + align:start position:0% +but I think the Lightning one is nicer + + + align:start position:0% +but I think the Lightning one is nicer +because it like makes it okay whoa the + + align:start position:0% +because it like makes it okay whoa the + + + align:start position:0% +because it like makes it okay whoa the +goal is back and forth between these two + + align:start position:0% +goal is back and forth between these two + + + align:start position:0% +goal is back and forth between these two +parties and lasts forever and you can do + + align:start position:0% +parties and lasts forever and you can do + + + align:start position:0% +parties and lasts forever and you can do +as many transactions as you want okay so + + align:start position:0% +as many transactions as you want okay so + + + align:start position:0% +as many transactions as you want okay so +how do you do that so there's two timing + + align:start position:0% +how do you do that so there's two timing + + + align:start position:0% +how do you do that so there's two timing +op coats that have been added to Bitcoin + + align:start position:0% +op coats that have been added to Bitcoin + + + align:start position:0% +op coats that have been added to Bitcoin +and like check sequence verifies is + + align:start position:0% +and like check sequence verifies is + + + align:start position:0% +and like check sequence verifies is +pretty much for lightning in my opinion + + align:start position:0% +pretty much for lightning in my opinion + + + align:start position:0% +pretty much for lightning in my opinion +that's that's the real use case there's + + align:start position:0% +that's that's the real use case there's + + + align:start position:0% +that's that's the real use case there's +also check check lock on verify so the + + align:start position:0% +also check check lock on verify so the + + + align:start position:0% +also check check lock on verify so the +idea of sequence verify is it's a + + align:start position:0% +idea of sequence verify is it's a + + + align:start position:0% +idea of sequence verify is it's a +relative lock time so it doesn't specify + + align:start position:0% +relative lock time so it doesn't specify + + + align:start position:0% +relative lock time so it doesn't specify +okay this transactions valid on March + + align:start position:0% +okay this transactions valid on March + + + align:start position:0% +okay this transactions valid on March +28th it says this transactions valid + + align:start position:0% +28th it says this transactions valid + + + align:start position:0% +28th it says this transactions valid +when the input is spending is a week old + + align:start position:0% +when the input is spending is a week old + + + align:start position:0% +when the input is spending is a week old +and by a week oh that's you know it's in + + align:start position:0% +and by a week oh that's you know it's in + + + align:start position:0% +and by a week oh that's you know it's in +a week's worth of blocks in the actual + + align:start position:0% +a week's worth of blocks in the actual + + + align:start position:0% +a week's worth of blocks in the actual +software we we don't usually use time we + + align:start position:0% +software we we don't usually use time we + + + align:start position:0% +software we we don't usually use time we +always use block ight it's sort of + + align:start position:0% +always use block ight it's sort of + + + align:start position:0% +always use block ight it's sort of +simpler to think about in a lot of ways + + align:start position:0% +simpler to think about in a lot of ways + + + align:start position:0% +simpler to think about in a lot of ways +but you can say okay well this you know + + align:start position:0% +but you can say okay well this you know + + + align:start position:0% +but you can say okay well this you know +this I sent to an output script and the + + align:start position:0% +this I sent to an output script and the + + + align:start position:0% +this I sent to an output script and the +output script specifies that you can + + align:start position:0% +output script specifies that you can + + + align:start position:0% +output script specifies that you can +only spend this these coins after the + + align:start position:0% +only spend this these coins after the + + + align:start position:0% +only spend this these coins after the +transaction creating them has been you + + align:start position:0% +transaction creating them has been you + + + align:start position:0% +transaction creating them has been you +know in a hundred block you know a + + align:start position:0% +know in a hundred block you know a + + + align:start position:0% +know in a hundred block you know a +hundred blocks deep so that's kind of an + + align:start position:0% +hundred blocks deep so that's kind of an + + + align:start position:0% +hundred blocks deep so that's kind of an +interesting useful thing requires yeah + + align:start position:0% +interesting useful thing requires yeah + + + align:start position:0% +interesting useful thing requires yeah +in confirmations if not you can't spend + + align:start position:0% +in confirmations if not you can't spend + + + align:start position:0% +in confirmations if not you can't spend +it I've checked long time verify it's a + + align:start position:0% +it I've checked long time verify it's a + + + align:start position:0% +it I've checked long time verify it's a +lot absolute long time off code so you + + align:start position:0% +lot absolute long time off code so you + + + align:start position:0% +lot absolute long time off code so you +require that the transaction be + + align:start position:0% +require that the transaction be + + + align:start position:0% +require that the transaction be +confirmed at high ten or or above and + + align:start position:0% +confirmed at high ten or or above and + + + align:start position:0% +confirmed at high ten or or above and +the difference between so what we said + + align:start position:0% +the difference between so what we said + + + align:start position:0% +the difference between so what we said +in the fund + + align:start position:0% +in the fund + + + align:start position:0% +in the fund +sorry the refunds transaction the refund + + align:start position:0% +sorry the refunds transaction the refund + + + align:start position:0% +sorry the refunds transaction the refund +transaction the transaction field has a + + align:start position:0% +transaction the transaction field has a + + + align:start position:0% +transaction the transaction field has a +lock time right so in this case here but + + align:start position:0% +lock time right so in this case here but + + + align:start position:0% +lock time right so in this case here but +the transaction itself has a long time + + align:start position:0% +the transaction itself has a long time + + + align:start position:0% +the transaction itself has a long time +and the OP but that's that's different + + align:start position:0% +and the OP but that's that's different + + + align:start position:0% +and the OP but that's that's different +from the OP code the what the off code + + align:start position:0% +from the OP code the what the off code + + + align:start position:0% +from the OP code the what the off code +does it says okay this output has a lock + + align:start position:0% +does it says okay this output has a lock + + + align:start position:0% +does it says okay this output has a lock +time because the output script ensures + + align:start position:0% +time because the output script ensures + + + align:start position:0% +time because the output script ensures +that the transaction itself has a long + + align:start position:0% +that the transaction itself has a long + + + align:start position:0% +that the transaction itself has a long +time right so basically what this off + + align:start position:0% +time right so basically what this off + + + align:start position:0% +time right so basically what this off +you know it says you say OP check lock + + align:start position:0% +you know it says you say OP check lock + + + align:start position:0% +you know it says you say OP check lock +time verify five hundred thousand and + + align:start position:0% +time verify five hundred thousand and + + + align:start position:0% +time verify five hundred thousand and +then it checks that the transactions + + align:start position:0% +then it checks that the transactions + + + align:start position:0% +then it checks that the transactions +lock time field is exactly equal to five + + align:start position:0% +lock time field is exactly equal to five + + + align:start position:0% +lock time field is exactly equal to five +hundred thousand + + align:start position:0% +hundred thousand + + + align:start position:0% +hundred thousand +so it's a way to enforce a transaction + + align:start position:0% +so it's a way to enforce a transaction + + + align:start position:0% +so it's a way to enforce a transaction +wide-field inside of an output it's a + + align:start position:0% +wide-field inside of an output it's a + + + align:start position:0% +wide-field inside of an output it's a +little weird but both of these become op + + align:start position:0% +little weird but both of these become op + + + align:start position:0% +little weird but both of these become op +codes that you can use in scripts and + + align:start position:0% +codes that you can use in scripts and + + + align:start position:0% +codes that you can use in scripts and +now you can specify like a make an + + align:start position:0% +now you can specify like a make an + + + align:start position:0% +now you can specify like a make an +address that has these weird timing + + align:start position:0% +address that has these weird timing + + + align:start position:0% +address that has these weird timing +properties okay any questions about + + align:start position:0% +properties okay any questions about + + + align:start position:0% +properties okay any questions about +these two yep + + align:start position:0% +these two yep + + + align:start position:0% +these two yep +you can mix them and match them check + + align:start position:0% +you can mix them and match them check + + + align:start position:0% +you can mix them and match them check +sequence verify is specific to an input + + align:start position:0% +sequence verify is specific to an input + + + align:start position:0% +sequence verify is specific to an input +so there's a sequence field in each + + align:start position:0% +so there's a sequence field in each + + + align:start position:0% +so there's a sequence field in each +input that was completely useless until + + align:start position:0% +input that was completely useless until + + + align:start position:0% +input that was completely useless until +like I said what well okay so if you + + align:start position:0% +like I said what well okay so if you + + + align:start position:0% +like I said what well okay so if you +look there's like a sequence and it was + + align:start position:0% +look there's like a sequence and it was + + + align:start position:0% +look there's like a sequence and it was +always just ffffff you know that's like + + align:start position:0% +always just ffffff you know that's like + + + align:start position:0% +always just ffffff you know that's like +2 to the 32 or whatever 2 to the 32 + + align:start position:0% +2 to the 32 or whatever 2 to the 32 + + + align:start position:0% +2 to the 32 or whatever 2 to the 32 +minus 1 I think and it didn't do + + align:start position:0% +minus 1 I think and it didn't do + + + align:start position:0% +minus 1 I think and it didn't do +anything Satoshi put it in because he + + align:start position:0% +anything Satoshi put it in because he + + + align:start position:0% +anything Satoshi put it in because he +thought ok this will this will let you + + align:start position:0% +thought ok this will this will let you + + + align:start position:0% +thought ok this will this will let you +indicate finality right where you can + + align:start position:0% +indicate finality right where you can + + + align:start position:0% +indicate finality right where you can +increment the sequence number so you say + + align:start position:0% +increment the sequence number so you say + + + align:start position:0% +increment the sequence number so you say +ok this is sequence 1 and then I can + + align:start position:0% +ok this is sequence 1 and then I can + + + align:start position:0% +ok this is sequence 1 and then I can +replace it with sequence 2 and it didn't + + align:start position:0% +replace it with sequence 2 and it didn't + + + align:start position:0% +replace it with sequence 2 and it didn't +work because you can't have consensus on + + align:start position:0% +work because you can't have consensus on + + + align:start position:0% +work because you can't have consensus on +those things so this was a field that + + align:start position:0% +those things so this was a field that + + + align:start position:0% +those things so this was a field that +was sort of unused in the inputs and + + align:start position:0% +was sort of unused in the inputs and + + + align:start position:0% +was sort of unused in the inputs and +what they did is they said ok we'll make + + align:start position:0% +what they did is they said ok we'll make + + + align:start position:0% +what they did is they said ok we'll make +that a sequence number where if you now + + align:start position:0% +that a sequence number where if you now + + + align:start position:0% +that a sequence number where if you now +make this say you make the sequence + + align:start position:0% +make this say you make the sequence + + + align:start position:0% +make this say you make the sequence +number a hundred for example and then in + + align:start position:0% +number a hundred for example and then in + + + align:start position:0% +number a hundred for example and then in +your transaction it'll say ok this this + + align:start position:0% +your transaction it'll say ok this this + + + align:start position:0% +your transaction it'll say ok this this +this TX you know this transaction output + + align:start position:0% +this TX you know this transaction output + + + align:start position:0% +this TX you know this transaction output +that you're spending is it a hundred + + align:start position:0% +that you're spending is it a hundred + + + align:start position:0% +that you're spending is it a hundred +blocks old and if so we're good if not + + align:start position:0% +blocks old and if so we're good if not + + + align:start position:0% +blocks old and if so we're good if not +this input spending fails so it's + + align:start position:0% +this input spending fails so it's + + + align:start position:0% +this input spending fails so it's +another check in addition to the + + align:start position:0% +another check in addition to the + + + align:start position:0% +another check in addition to the +signature and then you can also ensure + + align:start position:0% +signature and then you can also ensure + + + align:start position:0% +signature and then you can also ensure +that that with the width check sequence + + align:start position:0% +that that with the width check sequence + + + align:start position:0% +that that with the width check sequence +verify you can put in the opcodes you + + align:start position:0% +verify you can put in the opcodes you + + + align:start position:0% +verify you can put in the opcodes you +can put in the script ok this must have + + align:start position:0% +can put in the script ok this must have + + + align:start position:0% +can put in the script ok this must have +a sequence of 100 and then check that + + align:start position:0% +a sequence of 100 and then check that + + + align:start position:0% +a sequence of 100 and then check that +the sequence is equal you know equal or + + align:start position:0% +the sequence is equal you know equal or + + + align:start position:0% +the sequence is equal you know equal or +greater to the you know depth of the + + align:start position:0% +greater to the you know depth of the + + + align:start position:0% +greater to the you know depth of the +transaction and yet you can mix them and + + align:start position:0% +transaction and yet you can mix them and + + + align:start position:0% +transaction and yet you can mix them and +match them in the same script it's a + + align:start position:0% +match them in the same script it's a + + + align:start position:0% +match them in the same script it's a +little ugly to use because it was + + align:start position:0% +little ugly to use because it was + + + align:start position:0% +little ugly to use because it was +introduced as a soft work and they they + + align:start position:0% +introduced as a soft work and they they + + + align:start position:0% +introduced as a soft work and they they +renamed and opted not write a no op op + + align:start position:0% +renamed and opted not write a no op op + + + align:start position:0% +renamed and opted not write a no op op +got renamed to this this is like no op3 + + align:start position:0% +got renamed to this this is like no op3 + + + align:start position:0% +got renamed to this this is like no op3 +and so you have to push the the number + + align:start position:0% +and so you have to push the the number + + + align:start position:0% +and so you have to push the the number +you're checking on the stack up check + + align:start position:0% +you're checking on the stack up check + + + align:start position:0% +you're checking on the stack up check +sequence verify and then you have to + + align:start position:0% +sequence verify and then you have to + + + align:start position:0% +sequence verify and then you have to +drop the number off the stack because it + + align:start position:0% +drop the number off the stack because it + + + align:start position:0% +drop the number off the stack because it +the this opcode doesn't actually consume + + align:start position:0% +the this opcode doesn't actually consume + + + align:start position:0% +the this opcode doesn't actually consume +anything off the top of the stack so + + align:start position:0% +anything off the top of the stack so + + + align:start position:0% +anything off the top of the stack so +that it looks the same as a no op two + + align:start position:0% +that it looks the same as a no op two + + + align:start position:0% +that it looks the same as a no op two +nodes that don't know about it anyway so + + align:start position:0% +nodes that don't know about it anyway so + + + align:start position:0% +nodes that don't know about it anyway so +you've got these two ways to specify + + align:start position:0% +you've got these two ways to specify + + + align:start position:0% +you've got these two ways to specify +output timing okay good so then what you + + align:start position:0% +output timing okay good so then what you + + + align:start position:0% +output timing okay good so then what you +can do is you can revoke based on timing + + align:start position:0% +can do is you can revoke based on timing + + + align:start position:0% +can do is you can revoke based on timing +so the idea of the script and this is + + align:start position:0% +so the idea of the script and this is + + + align:start position:0% +so the idea of the script and this is +sort of in like see like notation not + + align:start position:0% +sort of in like see like notation not + + + align:start position:0% +sort of in like see like notation not +the actual op codes for Bitcoin because + + align:start position:0% +the actual op codes for Bitcoin because + + + align:start position:0% +the actual op codes for Bitcoin because +the actual op codes are kind of + + align:start position:0% +the actual op codes are kind of + + + align:start position:0% +the actual op codes are kind of +confusing the idea is okay you can spend + + align:start position:0% +confusing the idea is okay you can spend + + + align:start position:0% +confusing the idea is okay you can spend +with two of two multi-sig essentially + + align:start position:0% +with two of two multi-sig essentially + + + align:start position:0% +with two of two multi-sig essentially +right key a and key B or GC and wait a + + align:start position:0% +right key a and key B or GC and wait a + + + align:start position:0% +right key a and key B or GC and wait a +hundred blocks and buy wait a hundred + + align:start position:0% +hundred blocks and buy wait a hundred + + + align:start position:0% +hundred blocks and buy wait a hundred +blocks that means that this you know + + align:start position:0% +blocks that means that this you know + + + align:start position:0% +blocks that means that this you know +whatever you're spending has to be a + + align:start position:0% +whatever you're spending has to be a + + + align:start position:0% +whatever you're spending has to be a +hundred blocks you know confirmed a + + align:start position:0% +hundred blocks you know confirmed a + + + align:start position:0% +hundred blocks you know confirmed a +hundred blocks ago or more so a and B + + align:start position:0% +hundred blocks ago or more so a and B + + + align:start position:0% +hundred blocks ago or more so a and B +two that together they can spend any + + align:start position:0% +two that together they can spend any + + + align:start position:0% +two that together they can spend any +time they want secant it's together oops + + align:start position:0% +time they want secant it's together oops + + + align:start position:0% +time they want secant it's together oops +see you can spend but must wait and a + + align:start position:0% +see you can spend but must wait and a + + + align:start position:0% +see you can spend but must wait and a +and B can grab the coins first so this + + align:start position:0% +and B can grab the coins first so this + + + align:start position:0% +and B can grab the coins first so this +is a revocable transaction so the idea + + align:start position:0% +is a revocable transaction so the idea + + + align:start position:0% +is a revocable transaction so the idea +is you've got some and we call it a + + align:start position:0% +is you've got some and we call it a + + + align:start position:0% +is you've got some and we call it a +commitment transaction in the lightning + + align:start position:0% +commitment transaction in the lightning + + + align:start position:0% +commitment transaction in the lightning +paper you've got some input the funding + + align:start position:0% +paper you've got some input the funding + + + align:start position:0% +paper you've got some input the funding +transaction output you're spending that + + align:start position:0% +transaction output you're spending that + + + align:start position:0% +transaction output you're spending that +you've got you need to of to multi-sig + + align:start position:0% +you've got you need to of to multi-sig + + + align:start position:0% +you've got you need to of to multi-sig +so like Bob's signs and sends it over to + + align:start position:0% +so like Bob's signs and sends it over to + + + align:start position:0% +so like Bob's signs and sends it over to +Alice and then you've got that script + + align:start position:0% +Alice and then you've got that script + + + align:start position:0% +Alice and then you've got that script +where it's okay it's Alice's key and you + + align:start position:0% +where it's okay it's Alice's key and you + + + align:start position:0% +where it's okay it's Alice's key and you +wait a hundred blocks or Alice's key and + + align:start position:0% +wait a hundred blocks or Alice's key and + + + align:start position:0% +wait a hundred blocks or Alice's key and +you make a new key for Bob like the Bob + + align:start position:0% +you make a new key for Bob like the Bob + + + align:start position:0% +you make a new key for Bob like the Bob +revoke key and this has two coins this + + align:start position:0% +revoke key and this has two coins this + + + align:start position:0% +revoke key and this has two coins this +has eight coins + + align:start position:0% +has eight coins + + + align:start position:0% +has eight coins +Oh oops this should be our hold on I + + align:start position:0% +Oh oops this should be our hold on I + + + align:start position:0% +Oh oops this should be our hold on I +should change that that's kind of gonna + + align:start position:0% +should change that that's kind of gonna + + + align:start position:0% +should change that that's kind of gonna +be really confusing wait + + align:start position:0% +be really confusing wait + + + align:start position:0% +be really confusing wait +I put the R in the wrong place let me + + align:start position:0% +I put the R in the wrong place let me + + + align:start position:0% +I put the R in the wrong place let me +redo that's that's a typo but it's super + + align:start position:0% +redo that's that's a typo but it's super + + + align:start position:0% +redo that's that's a typo but it's super +confusing yeah + + align:start position:0% + + + + align:start position:0% + +Elessar and Bob Allison wait did I so + + align:start position:0% +Elessar and Bob Allison wait did I so + + + align:start position:0% +Elessar and Bob Allison wait did I so +put the same thing on both right this + + align:start position:0% +put the same thing on both right this + + + align:start position:0% +put the same thing on both right this +wood is Alice R and Bob yeah and there's + + align:start position:0% +wood is Alice R and Bob yeah and there's + + + align:start position:0% +wood is Alice R and Bob yeah and there's +like when you're actually coding this + + align:start position:0% +like when you're actually coding this + + + align:start position:0% +like when you're actually coding this +stuff it's pretty easy to screw up + + align:start position:0% +stuff it's pretty easy to screw up + + + align:start position:0% +stuff it's pretty easy to screw up +there's a lot of like wait who's Allison + + align:start position:0% +there's a lot of like wait who's Allison + + + align:start position:0% +there's a lot of like wait who's Allison +who's Bob so I don't in any of the code + + align:start position:0% +who's Bob so I don't in any of the code + + + align:start position:0% +who's Bob so I don't in any of the code +I don't use Allison Bob I use like mine + + align:start position:0% +I don't use Allison Bob I use like mine + + + align:start position:0% +I don't use Allison Bob I use like mine +and theirs but a lot of times it's not + + align:start position:0% +and theirs but a lot of times it's not + + + align:start position:0% +and theirs but a lot of times it's not +clear because it's like held by us so + + align:start position:0% +clear because it's like held by us so + + + align:start position:0% +clear because it's like held by us so +this is the transaction that Bob creates + + align:start position:0% +this is the transaction that Bob creates + + + align:start position:0% +this is the transaction that Bob creates +Bob signs transfer balance and then it + + align:start position:0% +Bob signs transfer balance and then it + + + align:start position:0% +Bob signs transfer balance and then it +sits on Alice's hard drive yes okay so + + align:start position:0% +sits on Alice's hard drive yes okay so + + + align:start position:0% +sits on Alice's hard drive yes okay so +you don't you make these these separate + + align:start position:0% +you don't you make these these separate + + + align:start position:0% +you don't you make these these separate +keys right it's it's a key that Alice + + align:start position:0% +keys right it's it's a key that Alice + + + align:start position:0% +keys right it's it's a key that Alice +creates right Alice creates another pub + + align:start position:0% +creates right Alice creates another pub + + + align:start position:0% +creates right Alice creates another pub +key pair and tells the pub key to Bob it + + align:start position:0% +key pair and tells the pub key to Bob it + + + align:start position:0% +key pair and tells the pub key to Bob it +says and this is her sort of revocable + + align:start position:0% +says and this is her sort of revocable + + + align:start position:0% +says and this is her sort of revocable +key yeah where Alice kinland basically + + align:start position:0% +key yeah where Alice kinland basically + + + align:start position:0% +key yeah where Alice kinland basically +what else house is house gives the + + align:start position:0% +what else house is house gives the + + + align:start position:0% +what else house is house gives the +private key to Bob in order to revoke + + align:start position:0% +private key to Bob in order to revoke + + + align:start position:0% +private key to Bob in order to revoke +this transaction so there's sort of + + align:start position:0% +this transaction so there's sort of + + + align:start position:0% +this transaction so there's sort of +mirror images in both cases both parties + + align:start position:0% +mirror images in both cases both parties + + + align:start position:0% +mirror images in both cases both parties +agree look Alice has got two coins Bob's + + align:start position:0% +agree look Alice has got two coins Bob's + + + align:start position:0% +agree look Alice has got two coins Bob's +got eight coins + + align:start position:0% +got eight coins + + + align:start position:0% +got eight coins +right but the transaction that Bob + + align:start position:0% +right but the transaction that Bob + + + align:start position:0% +right but the transaction that Bob +creates and signs yes the transaction + + align:start position:0% +creates and signs yes the transaction + + + align:start position:0% +creates and signs yes the transaction +that Bob creates and signs sends Bob + + align:start position:0% +that Bob creates and signs sends Bob + + + align:start position:0% +that Bob creates and signs sends Bob +eight coins in the clear this is just a + + align:start position:0% +eight coins in the clear this is just a + + + align:start position:0% +eight coins in the clear this is just a +regular old pay to pub key hash where + + align:start position:0% +regular old pay to pub key hash where + + + align:start position:0% +regular old pay to pub key hash where +Bob gets eight coins the coins that are + + align:start position:0% +Bob gets eight coins the coins that are + + + align:start position:0% +Bob gets eight coins the coins that are +Alice's though Alice has to wait a + + align:start position:0% +Alice's though Alice has to wait a + + + align:start position:0% +Alice's though Alice has to wait a +hundred blocks if she broadcasts this + + align:start position:0% +hundred blocks if she broadcasts this + + + align:start position:0% +hundred blocks if she broadcasts this +commitment transaction + + align:start position:0% +commitment transaction + + + align:start position:0% +commitment transaction +she can't spend her money for a day like + + align:start position:0% +she can't spend her money for a day like + + + align:start position:0% +she can't spend her money for a day like +a hundred block whatever a hundred block + + align:start position:0% +a hundred block whatever a hundred block + + + align:start position:0% +a hundred block whatever a hundred block +day Bob can get the money but only if he + + align:start position:0% +day Bob can get the money but only if he + + + align:start position:0% +day Bob can get the money but only if he +knows Alice's are key Alice's were you + + align:start position:0% +knows Alice's are key Alice's were you + + + align:start position:0% +knows Alice's are key Alice's were you +know revocable key so you know Alice has + + align:start position:0% +know revocable key so you know Alice has + + + align:start position:0% +know revocable key so you know Alice has +this Bob doesn't and in the Bob case + + align:start position:0% +this Bob doesn't and in the Bob case + + + align:start position:0% +this Bob doesn't and in the Bob case +it's similar + + align:start position:0% +it's similar + + + align:start position:0% +it's similar +you know the outputs are the same but + + align:start position:0% +you know the outputs are the same but + + + align:start position:0% +you know the outputs are the same but +the ideas Alice creates this Alice signs + + align:start position:0% +the ideas Alice creates this Alice signs + + + align:start position:0% +the ideas Alice creates this Alice signs +it + + align:start position:0% +it + + + align:start position:0% +it +hands it over to Bob and in this case + + align:start position:0% +hands it over to Bob and in this case + + + align:start position:0% +hands it over to Bob and in this case +the transaction is well Alice gets two + + align:start position:0% +the transaction is well Alice gets two + + + align:start position:0% +the transaction is well Alice gets two +coins in the clear right + + align:start position:0% +coins in the clear right + + + align:start position:0% +coins in the clear right +this is immediately spendable no fancy + + align:start position:0% +this is immediately spendable no fancy + + + align:start position:0% +this is immediately spendable no fancy +scripts or anything Bob gets the money + + align:start position:0% +scripts or anything Bob gets the money + + + align:start position:0% +scripts or anything Bob gets the money +but he has to wait a day or Alice can + + align:start position:0% +but he has to wait a day or Alice can + + + align:start position:0% +but he has to wait a day or Alice can +spend the money if she knows Bob's + + align:start position:0% +spend the money if she knows Bob's + + + align:start position:0% +spend the money if she knows Bob's +revocable key this Bob our key right so + + align:start position:0% +revocable key this Bob our key right so + + + align:start position:0% +revocable key this Bob our key right so +either party at any time can broadcast + + align:start position:0% +either party at any time can broadcast + + + align:start position:0% +either party at any time can broadcast +these transactions the thing is the + + align:start position:0% +these transactions the thing is the + + + align:start position:0% +these transactions the thing is the +money they're supposed to get right so + + align:start position:0% +money they're supposed to get right so + + + align:start position:0% +money they're supposed to get right so +in in Bob's case Bob can add Bob's + + align:start position:0% +in in Bob's case Bob can add Bob's + + + align:start position:0% +in in Bob's case Bob can add Bob's +signature broadcast but now he has to + + align:start position:0% +signature broadcast but now he has to + + + align:start position:0% +signature broadcast but now he has to +wait no big deal wait a hundred blocks + + align:start position:0% +wait no big deal wait a hundred blocks + + + align:start position:0% +wait no big deal wait a hundred blocks +okay in Alice's case okay she can close + + align:start position:0% +okay in Alice's case okay she can close + + + align:start position:0% +okay in Alice's case okay she can close +it and you know put her signature on + + align:start position:0% +it and you know put her signature on + + + align:start position:0% +it and you know put her signature on +here broadcast wait a day spend the + + align:start position:0% +here broadcast wait a day spend the + + + align:start position:0% +here broadcast wait a day spend the +money but what's nice is you can revoke + + align:start position:0% +money but what's nice is you can revoke + + + align:start position:0% +money but what's nice is you can revoke +it right so Alice can say look I'm Alice + + align:start position:0% +it right so Alice can say look I'm Alice + + + align:start position:0% +it right so Alice can say look I'm Alice +can tell Bob I'm not gonna do this I'm + + align:start position:0% +can tell Bob I'm not gonna do this I'm + + + align:start position:0% +can tell Bob I'm not gonna do this I'm +not going to use this transaction the + + align:start position:0% +not going to use this transaction the + + + align:start position:0% +not going to use this transaction the +way I'll prove it to you the whale you + + align:start position:0% +way I'll prove it to you the whale you + + + align:start position:0% +way I'll prove it to you the whale you +know I deleted it and Bob's like yeah + + align:start position:0% +know I deleted it and Bob's like yeah + + + align:start position:0% +know I deleted it and Bob's like yeah +sure you deleted the way I'll prove you + + align:start position:0% +sure you deleted the way I'll prove you + + + align:start position:0% +sure you deleted the way I'll prove you +that I deleted this is I will tell you + + align:start position:0% +that I deleted this is I will tell you + + + align:start position:0% +that I deleted this is I will tell you +the private key I'll tell you Alice R so + + align:start position:0% +the private key I'll tell you Alice R so + + + align:start position:0% +the private key I'll tell you Alice R so +now you Bob knows Bob because Bob + + align:start position:0% +now you Bob knows Bob because Bob + + + align:start position:0% +now you Bob knows Bob because Bob +actually Bob created this transaction + + align:start position:0% +actually Bob created this transaction + + + align:start position:0% +actually Bob created this transaction +right Bob signed it Bob knows what it + + align:start position:0% +right Bob signed it Bob knows what it + + + align:start position:0% +right Bob signed it Bob knows what it +looks like and Bob knows well yeah this + + align:start position:0% +looks like and Bob knows well yeah this + + + align:start position:0% +looks like and Bob knows well yeah this +is the script since Bob knows Alice R + + align:start position:0% +is the script since Bob knows Alice R + + + align:start position:0% +is the script since Bob knows Alice R +and Bob knows his own key Bob Noah's + + align:start position:0% +and Bob knows his own key Bob Noah's + + + align:start position:0% +and Bob knows his own key Bob Noah's +look this money's mine this money's mine + + align:start position:0% +look this money's mine this money's mine + + + align:start position:0% +look this money's mine this money's mine +to write because I can do this + + align:start position:0% +to write because I can do this + + + align:start position:0% +to write because I can do this +immediately so if you brought this + + align:start position:0% +immediately so if you brought this + + + align:start position:0% +immediately so if you brought this +transaction I don't have to even touch + + align:start position:0% +transaction I don't have to even touch + + + align:start position:0% +transaction I don't have to even touch +this because it's just my money and this + + align:start position:0% +this because it's just my money and this + + + align:start position:0% +this because it's just my money and this +output I can spend immediately well you + + align:start position:0% +output I can spend immediately well you + + + align:start position:0% +output I can spend immediately well you +have to wait a hundred blocks so and you + + align:start position:0% +have to wait a hundred blocks so and you + + + align:start position:0% +have to wait a hundred blocks so and you +know my software's gonna automatically + + align:start position:0% +know my software's gonna automatically + + + align:start position:0% +know my software's gonna automatically +do that so I know Alice R its private + + align:start position:0% +do that so I know Alice R its private + + + align:start position:0% +do that so I know Alice R its private +key I know Bob's private key I just take + + align:start position:0% +key I know Bob's private key I just take + + + align:start position:0% +key I know Bob's private key I just take +these two coins as soon as I see this + + align:start position:0% +these two coins as soon as I see this + + + align:start position:0% +these two coins as soon as I see this +transaction I take these two coins I + + align:start position:0% +transaction I take these two coins I + + + align:start position:0% +transaction I take these two coins I +spend them back to Bob's address and get + + align:start position:0% +spend them back to Bob's address and get + + + align:start position:0% +spend them back to Bob's address and get +all 10 so that's a pretty convincing way + + align:start position:0% +all 10 so that's a pretty convincing way + + + align:start position:0% +all 10 so that's a pretty convincing way +for Alice to say look I'm not gonna use + + align:start position:0% +for Alice to say look I'm not gonna use + + + align:start position:0% +for Alice to say look I'm not gonna use +this I'm deleting and to show you know + + align:start position:0% +this I'm deleting and to show you know + + + align:start position:0% +this I'm deleting and to show you know +even if I do use it here here's the key + + align:start position:0% +even if I do use it here here's the key + + + align:start position:0% +even if I do use it here here's the key +okay any questions about this yep yeah + + align:start position:0% +okay any questions about this yep yeah + + + align:start position:0% +okay any questions about this yep yeah +so Alice has to hand it over right this + + align:start position:0% +so Alice has to hand it over right this + + + align:start position:0% +so Alice has to hand it over right this +is just a regular you know 32 byte + + align:start position:0% +is just a regular you know 32 byte + + + align:start position:0% +is just a regular you know 32 byte +private key + + align:start position:0% +private key + + + align:start position:0% +private key +that Alice created and similar you know + + align:start position:0% +that Alice created and similar you know + + + align:start position:0% +that Alice created and similar you know +same idea for Bob they both create you + + align:start position:0% +same idea for Bob they both create you + + + align:start position:0% +same idea for Bob they both create you +know essentially the same transaction + + align:start position:0% +know essentially the same transaction + + + align:start position:0% +know essentially the same transaction +but with things swapped Bob Bob can + + align:start position:0% +but with things swapped Bob Bob can + + + align:start position:0% +but with things swapped Bob Bob can +broadcast this if he does he has to wait + + align:start position:0% +broadcast this if he does he has to wait + + + align:start position:0% +broadcast this if he does he has to wait +a day but if he reveals Bob Bob our + + align:start position:0% +a day but if he reveals Bob Bob our + + + align:start position:0% +a day but if he reveals Bob Bob our +private key to Alice Alice knows okay I + + align:start position:0% +private key to Alice Alice knows okay I + + + align:start position:0% +private key to Alice Alice knows okay I +get two coins in the clear and then + + align:start position:0% +get two coins in the clear and then + + + align:start position:0% +get two coins in the clear and then +these eight coins I can sign this I can + + align:start position:0% +these eight coins I can sign this I can + + + align:start position:0% +these eight coins I can sign this I can +sign this I can get these eight coins + + align:start position:0% +sign this I can get these eight coins + + + align:start position:0% +sign this I can get these eight coins +immediately Bob's got away today so + + align:start position:0% +immediately Bob's got away today so + + + align:start position:0% +immediately Bob's got away today so +that's a way to sort of say look I'm not + + align:start position:0% +that's a way to sort of say look I'm not + + + align:start position:0% +that's a way to sort of say look I'm not +going to use this any other questions + + align:start position:0% +going to use this any other questions + + + align:start position:0% +going to use this any other questions +okay so what you do with that is yeah + + align:start position:0% +okay so what you do with that is yeah + + + align:start position:0% +okay so what you do with that is yeah +either party can broadcast that to wait + + align:start position:0% +either party can broadcast that to wait + + + align:start position:0% +either party can broadcast that to wait +they exchange these revoked and + + align:start position:0% +they exchange these revoked and + + + align:start position:0% +they exchange these revoked and +revocation private private keys and now + + align:start position:0% +revocation private private keys and now + + + align:start position:0% +revocation private private keys and now +if they broadcast the counterparty can + + align:start position:0% +if they broadcast the counterparty can + + + align:start position:0% +if they broadcast the counterparty can +take all the funds so it's pretty pretty + + align:start position:0% +take all the funds so it's pretty pretty + + + align:start position:0% +take all the funds so it's pretty pretty +good so the idea is this is a lightning + + align:start position:0% +good so the idea is this is a lightning + + + align:start position:0% +good so the idea is this is a lightning +channel you've got this output you + + align:start position:0% +channel you've got this output you + + + align:start position:0% +channel you've got this output you +create these states okay the first state + + align:start position:0% +create these states okay the first state + + + align:start position:0% +create these states okay the first state +is Alice gets one coin Bob gets nine + + align:start position:0% +is Alice gets one coin Bob gets nine + + + align:start position:0% +is Alice gets one coin Bob gets nine +coin then what Bob wants to pay Alice so + + align:start position:0% +coin then what Bob wants to pay Alice so + + + align:start position:0% +coin then what Bob wants to pay Alice so +Bob says hey Alice I'm paying you for + + align:start position:0% +Bob says hey Alice I'm paying you for + + + align:start position:0% +Bob says hey Alice I'm paying you for +coins here I'll sign and create this new + + align:start position:0% +coins here I'll sign and create this new + + + align:start position:0% +coins here I'll sign and create this new +output this new transaction in it to + + align:start position:0% +output this new transaction in it to + + + align:start position:0% +output this new transaction in it to +Alice and Bob's and Alice says okay but + + align:start position:0% +Alice and Bob's and Alice says okay but + + + align:start position:0% +Alice and Bob's and Alice says okay but +now we have to revoke this one right + + align:start position:0% +now we have to revoke this one right + + + align:start position:0% +now we have to revoke this one right +we've got you know Alice has this it's + + align:start position:0% +we've got you know Alice has this it's + + + align:start position:0% +we've got you know Alice has this it's +signed Alice can broadcast it but Alice + + align:start position:0% +signed Alice can broadcast it but Alice + + + align:start position:0% +signed Alice can broadcast it but Alice +also wants to be sure that Bob can't + + align:start position:0% +also wants to be sure that Bob can't + + + align:start position:0% +also wants to be sure that Bob can't +broadcast this anymore so they sort of + + align:start position:0% +broadcast this anymore so they sort of + + + align:start position:0% +broadcast this anymore so they sort of +trash it right they reveal there are + + align:start position:0% +trash it right they reveal there are + + + align:start position:0% +trash it right they reveal there are +private keys to each other so in + + align:start position:0% +private keys to each other so in + + + align:start position:0% +private keys to each other so in +practice right it could be well only Bob + + align:start position:0% +practice right it could be well only Bob + + + align:start position:0% +practice right it could be well only Bob +has to reveal the our private key in + + align:start position:0% +has to reveal the our private key in + + + align:start position:0% +has to reveal the our private key in +this case because Alice is never going + + align:start position:0% +this case because Alice is never going + + + align:start position:0% +this case because Alice is never going +to well you know alice is gonna + + align:start position:0% +to well you know alice is gonna + + + align:start position:0% +to well you know alice is gonna +broadcast this not this it's just so + + align:start position:0% +broadcast this not this it's just so + + + align:start position:0% +broadcast this not this it's just so +much simpler if they both if they both + + align:start position:0% +much simpler if they both if they both + + + align:start position:0% +much simpler if they both if they both +reveal the R keys because then you don't + + align:start position:0% +reveal the R keys because then you don't + + + align:start position:0% +reveal the R keys because then you don't +have to worry about like something you + + align:start position:0% +have to worry about like something you + + + align:start position:0% +have to worry about like something you +know what happens in the future when + + align:start position:0% +know what happens in the future when + + + align:start position:0% +know what happens in the future when +Alice has 0.5 and Alice still has this + + align:start position:0% +Alice has 0.5 and Alice still has this + + + align:start position:0% +Alice has 0.5 and Alice still has this +thing so it's really simple you just + + align:start position:0% +thing so it's really simple you just + + + align:start position:0% +thing so it's really simple you just +they both reveal and now this + + align:start position:0% +they both reveal and now this + + + align:start position:0% +they both reveal and now this +transaction this state one it's + + align:start position:0% +transaction this state one it's + + + align:start position:0% +transaction this state one it's +basically on broadcast you know you're + + align:start position:0% +basically on broadcast you know you're + + + align:start position:0% +basically on broadcast you know you're +not gonna use it and they can keep doing + + align:start position:0% +not gonna use it and they can keep doing + + + align:start position:0% +not gonna use it and they can keep doing +that and they can go back and forth + + align:start position:0% +that and they can go back and forth + + + align:start position:0% +that and they can go back and forth +right so now Alice phase Bob says hey or + + align:start position:0% +right so now Alice phase Bob says hey or + + + align:start position:0% +right so now Alice phase Bob says hey or +no oops + + align:start position:0% +no oops + + + align:start position:0% +no oops +go back and forth oh well oops anyway + + align:start position:0% +go back and forth oh well oops anyway + + + align:start position:0% +go back and forth oh well oops anyway +you can you can make this like Alice + + align:start position:0% +you can you can make this like Alice + + + align:start position:0% +you can you can make this like Alice +back to two and Bob back to eight or + + align:start position:0% +back to two and Bob back to eight or + + + align:start position:0% +back to two and Bob back to eight or +whatever you know basically arbitrary + + align:start position:0% +whatever you know basically arbitrary + + + align:start position:0% +whatever you know basically arbitrary +numbers you can keep going in both + + align:start position:0% +numbers you can keep going in both + + + align:start position:0% +numbers you can keep going in both +directions and you know deleting the old + + align:start position:0% +directions and you know deleting the old + + + align:start position:0% +directions and you know deleting the old +old so that's pretty useful there's no + + align:start position:0% +old so that's pretty useful there's no + + + align:start position:0% +old so that's pretty useful there's no +lock time for the transact for the + + align:start position:0% +lock time for the transact for the + + + align:start position:0% +lock time for the transact for the +channel itself the channel can just keep + + align:start position:0% +channel itself the channel can just keep + + + align:start position:0% +channel itself the channel can just keep +going on forever and Alice and Bob can + + align:start position:0% +going on forever and Alice and Bob can + + + align:start position:0% +going on forever and Alice and Bob can +keep sending these things it's a little + + align:start position:0% +keep sending these things it's a little + + + align:start position:0% +keep sending these things it's a little +more complicated I didn't put yeah I + + align:start position:0% +more complicated I didn't put yeah I + + + align:start position:0% +more complicated I didn't put yeah I +didn't put the the messages but they + + align:start position:0% +didn't put the the messages but they + + + align:start position:0% +didn't put the the messages but they +have to send four more messages you can + + align:start position:0% +have to send four more messages you can + + + align:start position:0% +have to send four more messages you can +optimize it to three because right so if + + align:start position:0% +optimize it to three because right so if + + + align:start position:0% +optimize it to three because right so if +you've Alice and Bob the first thing + + align:start position:0% +you've Alice and Bob the first thing + + + align:start position:0% +you've Alice and Bob the first thing +they do is Alice sends a signature so + + align:start position:0% +they do is Alice sends a signature so + + + align:start position:0% +they do is Alice sends a signature so +let's say they're you know they're at + + align:start position:0% +let's say they're you know they're at + + + align:start position:0% +let's say they're you know they're at +state five okay so she says here's a + + align:start position:0% +state five okay so she says here's a + + + align:start position:0% +state five okay so she says here's a +signature for state six and Bob says + + align:start position:0% +signature for state six and Bob says + + + align:start position:0% +signature for state six and Bob says +okay I'll give you a signature for state + + align:start position:0% +okay I'll give you a signature for state + + + align:start position:0% +okay I'll give you a signature for state +six so now they both build state six + + align:start position:0% +six so now they both build state six + + + align:start position:0% +six so now they both build state six +alright they've let's say you know go + + align:start position:0% +alright they've let's say you know go + + + align:start position:0% +alright they've let's say you know go +from five to six and then Alice can say + + align:start position:0% +from five to six and then Alice can say + + + align:start position:0% +from five to six and then Alice can say +okay I'll give you your you know + + align:start position:0% +okay I'll give you your you know + + + align:start position:0% +okay I'll give you your you know +revocation key for state five and then + + align:start position:0% +revocation key for state five and then + + + align:start position:0% +revocation key for state five and then +Bob can say okay I'll give you a + + align:start position:0% +Bob can say okay I'll give you a + + + align:start position:0% +Bob can say okay I'll give you a +revocation keep for Steve five and then + + align:start position:0% +revocation keep for Steve five and then + + + align:start position:0% +revocation keep for Steve five and then +they're done right then they've you know + + align:start position:0% +they're done right then they've you know + + + align:start position:0% +they're done right then they've you know +they've created the new state and + + align:start position:0% +they've created the new state and + + + align:start position:0% +they've created the new state and +revoked the old state you can't squish + + align:start position:0% +revoked the old state you can't squish + + + align:start position:0% +revoked the old state you can't squish +really if Alice cannot put Rev five here + + align:start position:0% +really if Alice cannot put Rev five here + + + align:start position:0% +really if Alice cannot put Rev five here +in the same message do you know why it + + align:start position:0% +in the same message do you know why it + + + align:start position:0% +in the same message do you know why it +why not so yeah well yeah Rev key just + + align:start position:0% +why not so yeah well yeah Rev key just + + + align:start position:0% +why not so yeah well yeah Rev key just +yeah abbreviate to Rev so why would this + + align:start position:0% +yeah abbreviate to Rev so why would this + + + align:start position:0% +yeah abbreviate to Rev so why would this +be bad if Alice says look here's state + + align:start position:0% +be bad if Alice says look here's state + + + align:start position:0% +be bad if Alice says look here's state +six and I'm revoking my claim on state + + align:start position:0% +six and I'm revoking my claim on state + + + align:start position:0% +six and I'm revoking my claim on state +five what what goes wrong if you do that + + align:start position:0% + + + + align:start position:0% + +no quiet Bob Bob broadcasting states + + align:start position:0% +no quiet Bob Bob broadcasting states + + + align:start position:0% +no quiet Bob Bob broadcasting states +sticks is okay in that case so you do + + align:start position:0% +sticks is okay in that case so you do + + + align:start position:0% +sticks is okay in that case so you do +that no because he doesn't he doesn't + + align:start position:0% +that no because he doesn't he doesn't + + + align:start position:0% +that no because he doesn't he doesn't +because because because state five is + + align:start position:0% +because because because state five is + + + align:start position:0% +because because because state five is +not broadcast right only Alice can sign + + align:start position:0% +not broadcast right only Alice can sign + + + align:start position:0% +not broadcast right only Alice can sign +in broadcast state five so the problem + + align:start position:0% +in broadcast state five so the problem + + + align:start position:0% +in broadcast state five so the problem +with this is if you do this Bob's fine + + align:start position:0% +with this is if you do this Bob's fine + + + align:start position:0% +with this is if you do this Bob's fine +alice is stuck right because Alice does + + align:start position:0% +alice is stuck right because Alice does + + + align:start position:0% +alice is stuck right because Alice does +not have state six on her drive right + + align:start position:0% +not have state six on her drive right + + + align:start position:0% +not have state six on her drive right +all Alice has on her drive is state five + + align:start position:0% +all Alice has on her drive is state five + + + align:start position:0% +all Alice has on her drive is state five +and she's just revealed the key for + + align:start position:0% +and she's just revealed the key for + + + align:start position:0% +and she's just revealed the key for +state five to revoke it so basically + + align:start position:0% +state five to revoke it so basically + + + align:start position:0% +state five to revoke it so basically +like alice has nothing at this point and + + align:start position:0% +like alice has nothing at this point and + + + align:start position:0% +like alice has nothing at this point and +Bob can just wait analysis stuck and + + align:start position:0% +Bob can just wait analysis stuck and + + + align:start position:0% +Bob can just wait analysis stuck and +then that's that's a really good + + align:start position:0% +then that's that's a really good + + + align:start position:0% +then that's that's a really good +position for Bob to be in because Bob is + + align:start position:0% +position for Bob to be in because Bob is + + + align:start position:0% +position for Bob to be in because Bob is +like hey I can close the channel I can + + align:start position:0% +like hey I can close the channel I can + + + align:start position:0% +like hey I can close the channel I can +close the channel at state five or state + + align:start position:0% +close the channel at state five or state + + + align:start position:0% +close the channel at state five or state +six probably he wants state six if + + align:start position:0% +six probably he wants state six if + + + align:start position:0% +six probably he wants state six if +usually you know you're sending money + + align:start position:0% +usually you know you're sending money + + + align:start position:0% +usually you know you're sending money +but I can close this channel and you can + + align:start position:0% +but I can close this channel and you can + + + align:start position:0% +but I can close this channel and you can +so give me some money you know you can + + align:start position:0% +so give me some money you know you can + + + align:start position:0% +so give me some money you know you can +close you know close the channel that + + align:start position:0% +close you know close the channel that + + + align:start position:0% +close you know close the channel that +kind of that's the attack right right + + align:start position:0% +kind of that's the attack right right + + + align:start position:0% +kind of that's the attack right right +and and you want it on your side right + + align:start position:0% +and and you want it on your side right + + + align:start position:0% +and and you want it on your side right +so this is creating a new state for Bob + + align:start position:0% +so this is creating a new state for Bob + + + align:start position:0% +so this is creating a new state for Bob +but it's revoking the old state for + + align:start position:0% +but it's revoking the old state for + + + align:start position:0% +but it's revoking the old state for +Alice if you want you do this so that's + + align:start position:0% +Alice if you want you do this so that's + + + align:start position:0% +Alice if you want you do this so that's +dangerous for you know Alice doesn't + + align:start position:0% +dangerous for you know Alice doesn't + + + align:start position:0% +dangerous for you know Alice doesn't +want to do that so the simplest way is + + align:start position:0% +want to do that so the simplest way is + + + align:start position:0% +want to do that so the simplest way is +okay create the new state by signing six + + align:start position:0% +okay create the new state by signing six + + + align:start position:0% +okay create the new state by signing six +revoking five revoking five you can + + align:start position:0% +revoking five revoking five you can + + + align:start position:0% +revoking five revoking five you can +optimize this though right can you guys + + align:start position:0% +optimize this though right can you guys + + + align:start position:0% +optimize this though right can you guys +see the reduces the three messages yeah + + align:start position:0% +see the reduces the three messages yeah + + + align:start position:0% +see the reduces the three messages yeah +he can send SIG's SIG's SIG's we have + + align:start position:0% +he can send SIG's SIG's SIG's we have + + + align:start position:0% +he can send SIG's SIG's SIG's we have +five at the same time so you get down + + align:start position:0% +five at the same time so you get down + + + align:start position:0% +five at the same time so you get down +into three messages so that's cool it's + + align:start position:0% +into three messages so that's cool it's + + + align:start position:0% +into three messages so that's cool it's +you know basically here's state six + + align:start position:0% +you know basically here's state six + + + align:start position:0% +you know basically here's state six +okay here's state six and I revoke my + + align:start position:0% +okay here's state six and I revoke my + + + align:start position:0% +okay here's state six and I revoke my +claim on say five okay overflow point + + align:start position:0% +claim on say five okay overflow point + + + align:start position:0% +claim on say five okay overflow point +claim let's say five then they both + + align:start position:0% +claim let's say five then they both + + + align:start position:0% +claim let's say five then they both +update their you know once this happens + + align:start position:0% +update their you know once this happens + + + align:start position:0% +update their you know once this happens +the UI is finished + + align:start position:0% + + + + align:start position:0% + +you end up it ends up being faster if + + align:start position:0% +you end up it ends up being faster if + + + align:start position:0% +you end up it ends up being faster if +you pre generate like one key ahead + + align:start position:0% +you pre generate like one key ahead + + + align:start position:0% +you pre generate like one key ahead +where you say like hey here's the next + + align:start position:0% +where you say like hey here's the next + + + align:start position:0% +where you say like hey here's the next +public key I'm gonna use all so that + + align:start position:0% +public key I'm gonna use all so that + + + align:start position:0% +public key I'm gonna use all so that +it'll do so that I can write cuz Alice + + align:start position:0% +it'll do so that I can write cuz Alice + + + align:start position:0% +it'll do so that I can write cuz Alice +one she's building state six she needs + + align:start position:0% +one she's building state six she needs + + + align:start position:0% +one she's building state six she needs +to know Bob's a revocation key in the + + align:start position:0% +to know Bob's a revocation key in the + + + align:start position:0% +to know Bob's a revocation key in the +state six so you pre share like one or + + align:start position:0% +state six so you pre share like one or + + + align:start position:0% +state six so you pre share like one or +two steps ahead so that you don't have + + align:start position:0% +two steps ahead so that you don't have + + + align:start position:0% +two steps ahead so that you don't have +to say hey can you get me into the next + + align:start position:0% +to say hey can you get me into the next + + + align:start position:0% +to say hey can you get me into the next +key okay you know otherwise you'd have + + align:start position:0% +key okay you know otherwise you'd have + + + align:start position:0% +key okay you know otherwise you'd have +this message where it's like request + + align:start position:0% +this message where it's like request + + + align:start position:0% +this message where it's like request +state six key send it send the signature + + align:start position:0% +state six key send it send the signature + + + align:start position:0% +state six key send it send the signature +back so there's all there's like more + + align:start position:0% +back so there's all there's like more + + + align:start position:0% +back so there's all there's like more +data in these messages but that like + + align:start position:0% +data in these messages but that like + + + align:start position:0% +data in these messages but that like +optimize yeah yeah so so you also put + + align:start position:0% +optimize yeah yeah so so you also put + + + align:start position:0% +optimize yeah yeah so so you also put +some public keys in here in this this is + + align:start position:0% +some public keys in here in this this is + + + align:start position:0% +some public keys in here in this this is +the private key yes in here right you're + + align:start position:0% +the private key yes in here right you're + + + align:start position:0% +the private key yes in here right you're +sending the signature but you can also + + align:start position:0% +sending the signature but you can also + + + align:start position:0% +sending the signature but you can also +send here's how much I'm giving you + + align:start position:0% +send here's how much I'm giving you + + + align:start position:0% +send here's how much I'm giving you +here's what the times and stuff are most + + align:start position:0% +here's what the times and stuff are most + + + align:start position:0% +here's what the times and stuff are most +of it can be computed because the + + align:start position:0% +of it can be computed because the + + + align:start position:0% +of it can be computed because the +transactions don't change that much + + align:start position:0% +transactions don't change that much + + + align:start position:0% +transactions don't change that much +right the scripts are the same everyone + + align:start position:0% +right the scripts are the same everyone + + + align:start position:0% +right the scripts are the same everyone +knows what this is gonna look like so + + align:start position:0% +knows what this is gonna look like so + + + align:start position:0% +knows what this is gonna look like so +you don't have to actually send too much + + align:start position:0% +you don't have to actually send too much + + + align:start position:0% +you don't have to actually send too much +data another optimization didn't put in + + align:start position:0% +data another optimization didn't put in + + + align:start position:0% +data another optimization didn't put in +is you're gonna potentially have to + + align:start position:0% +is you're gonna potentially have to + + + align:start position:0% +is you're gonna potentially have to +retain all of these are private keys so + + align:start position:0% +retain all of these are private keys so + + + align:start position:0% +retain all of these are private keys so +if you make a million states and you + + align:start position:0% +if you make a million states and you + + + align:start position:0% +if you make a million states and you +know you and 900 you know whatever are + + align:start position:0% +know you and 900 you know whatever are + + + align:start position:0% +know you and 900 you know whatever are +revoked Bob has to keep track of all + + align:start position:0% +revoked Bob has to keep track of all + + + align:start position:0% +revoked Bob has to keep track of all +those million old Alice private keys + + align:start position:0% +those million old Alice private keys + + + align:start position:0% +those million old Alice private keys +analysis to keep track of all those old + + align:start position:0% +analysis to keep track of all those old + + + align:start position:0% +analysis to keep track of all those old +Bob private keys that's kind of annoying + + align:start position:0% +Bob private keys that's kind of annoying + + + align:start position:0% +Bob private keys that's kind of annoying +not the end of the world but it's like + + align:start position:0% +not the end of the world but it's like + + + align:start position:0% +not the end of the world but it's like +32 bytes each can be a couple hundred + + align:start position:0% +32 bytes each can be a couple hundred + + + align:start position:0% +32 bytes each can be a couple hundred +megabytes if you use this channel a lot + + align:start position:0% +megabytes if you use this channel a lot + + + align:start position:0% +megabytes if you use this channel a lot +so you can make this so I thought I came + + align:start position:0% +so you can make this so I thought I came + + + align:start position:0% +so you can make this so I thought I came +up with it but at the same time when I + + align:start position:0% +up with it but at the same time when I + + + align:start position:0% +up with it but at the same time when I +was coming up with it I was like no I'm + + align:start position:0% +was coming up with it I was like no I'm + + + align:start position:0% +was coming up with it I was like no I'm +I'm pretty sure this isn't some paper + + align:start position:0% +I'm pretty sure this isn't some paper + + + align:start position:0% +I'm pretty sure this isn't some paper +somewhere and I can't find it and then + + align:start position:0% +somewhere and I can't find it and then + + + align:start position:0% +somewhere and I can't find it and then +talking to people here apparently like + + align:start position:0% +talking to people here apparently like + + + align:start position:0% +talking to people here apparently like +it's a gold wasö it likes a professor + + align:start position:0% +it's a gold wasö it likes a professor + + + align:start position:0% +it's a gold wasö it likes a professor +here came up with it in like the 80s I + + align:start position:0% +here came up with it in like the 80s I + + + align:start position:0% +here came up with it in like the 80s I +called it L chrome because spelled + + align:start position:0% +called it L chrome because spelled + + + align:start position:0% +called it L chrome because spelled +backwards it's Merkel right + + align:start position:0% +backwards it's Merkel right + + + align:start position:0% +backwards it's Merkel right +so you have a binary tree and you say + + align:start position:0% +so you have a binary tree and you say + + + align:start position:0% +so you have a binary tree and you say +like ok 0 1 2 3 4 5 6 is the root for + + align:start position:0% +like ok 0 1 2 3 4 5 6 is the root for + + + align:start position:0% +like ok 0 1 2 3 4 5 6 is the root for +example and when you want to when you + + align:start position:0% +example and when you want to when you + + + align:start position:0% +example and when you want to when you +want to descend to the left you take the + + align:start position:0% +want to descend to the left you take the + + + align:start position:0% +want to descend to the left you take the +value here append and L or like maybe + + align:start position:0% +value here append and L or like maybe + + + align:start position:0% +value here append and L or like maybe +you know 0 is left and one is right or + + align:start position:0% +you know 0 is left and one is right or + + + align:start position:0% +you know 0 is left and one is right or +something or L or R and you hash it so + + align:start position:0% +something or L or R and you hash it so + + + align:start position:0% +something or L or R and you hash it so +you say ok I'm taking this value + + align:start position:0% +you say ok I'm taking this value + + + align:start position:0% +you say ok I'm taking this value +sticking something on hashing to get + + align:start position:0% +sticking something on hashing to get + + + align:start position:0% +sticking something on hashing to get +down here and similarly you know through + + align:start position:0% +down here and similarly you know through + + + align:start position:0% +down here and similarly you know through +here you make a big tree the idea there + + align:start position:0% +here you make a big tree the idea there + + + align:start position:0% +here you make a big tree the idea there +is you can reveal things sequentially + + align:start position:0% +is you can reveal things sequentially + + + align:start position:0% +is you can reveal things sequentially +and say ok I reveal 0 fine I'll store it + + align:start position:0% +and say ok I reveal 0 fine I'll store it + + + align:start position:0% +and say ok I reveal 0 fine I'll store it +I'll reveal one store it I reveal two + + align:start position:0% +I'll reveal one store it I reveal two + + + align:start position:0% +I'll reveal one store it I reveal two +now you can delete 0 1 because you know + + align:start position:0% +now you can delete 0 1 because you know + + + align:start position:0% +now you can delete 0 1 because you know +the parent and you can compute 0 and 1 + + align:start position:0% +the parent and you can compute 0 and 1 + + + align:start position:0% +the parent and you can compute 0 and 1 +from knowing to right so I give you 1 0 + + align:start position:0% +from knowing to right so I give you 1 0 + + + align:start position:0% +from knowing to right so I give you 1 0 +give you 1 give you 2 you believe 0 1 + + align:start position:0% +give you 1 give you 2 you believe 0 1 + + + align:start position:0% +give you 1 give you 2 you believe 0 1 +then I give you 3 4 5 you delete 3 & 4 + + align:start position:0% +then I give you 3 4 5 you delete 3 & 4 + + + align:start position:0% +then I give you 3 4 5 you delete 3 & 4 +then I want to give you 6 you delete 2 & + + align:start position:0% +then I want to give you 6 you delete 2 & + + + align:start position:0% +then I want to give you 6 you delete 2 & +5 so that way you only have to store or + + align:start position:0% +5 so that way you only have to store or + + + align:start position:0% +5 so that way you only have to store or +log in secrets right but when you know + + align:start position:0% +log in secrets right but when you know + + + align:start position:0% +log in secrets right but when you know +you can't give in 0 & 1 you can't + + align:start position:0% +you can't give in 0 & 1 you can't + + + align:start position:0% +you can't give in 0 & 1 you can't +compute 2 and given 3 you know two three + + align:start position:0% +compute 2 and given 3 you know two three + + + align:start position:0% +compute 2 and given 3 you know two three +and four you can't compute 5 or 6 but + + align:start position:0% +and four you can't compute 5 or 6 but + + + align:start position:0% +and four you can't compute 5 or 6 but +once you've got them you can compute all + + align:start position:0% +once you've got them you can compute all + + + align:start position:0% +once you've got them you can compute all +the old ones so if we do that for the + + align:start position:0% +the old ones so if we do that for the + + + align:start position:0% +the old ones so if we do that for the +the secret Keys that like reduces + + align:start position:0% +the secret Keys that like reduces + + + align:start position:0% +the secret Keys that like reduces +storage a lot so that's kind of a nice + + align:start position:0% +storage a lot so that's kind of a nice + + + align:start position:0% +storage a lot so that's kind of a nice +optimization it's pretty quick and then + + align:start position:0% +optimization it's pretty quick and then + + + align:start position:0% +optimization it's pretty quick and then +so then you basically your your total + + align:start position:0% +so then you basically your your total + + + align:start position:0% +so then you basically your your total +data that you're storing for these + + align:start position:0% +data that you're storing for these + + + align:start position:0% +data that you're storing for these +channels never gets more than like a + + align:start position:0% +channels never gets more than like a + + + align:start position:0% +channels never gets more than like a +kilobyte or two so that's pretty useful + + align:start position:0% +kilobyte or two so that's pretty useful + + + align:start position:0% +kilobyte or two so that's pretty useful +ok other questions on this this alone + + align:start position:0% +ok other questions on this this alone + + + align:start position:0% +ok other questions on this this alone +actually is really complicated like yeah + + align:start position:0% +actually is really complicated like yeah + + + align:start position:0% +actually is really complicated like yeah +so there is a there is a sort of like + + align:start position:0% +so there is a there is a sort of like + + + align:start position:0% +so there is a there is a sort of like +superposition time here right we're at + + align:start position:0% +superposition time here right we're at + + + align:start position:0% +superposition time here right we're at +time so let's say this is x 0 this is + + align:start position:0% +time so let's say this is x 0 this is + + + align:start position:0% +time so let's say this is x 0 this is +time 1 this is time to this time 3 so at + + align:start position:0% +time 1 this is time to this time 3 so at + + + align:start position:0% +time 1 this is time to this time 3 so at +time 1 Bob's got a got two states he can + + align:start position:0% +time 1 Bob's got a got two states he can + + + align:start position:0% +time 1 Bob's got a got two states he can +broadcast right Bob's like I can do six + + align:start position:0% +broadcast right Bob's like I can do six + + + align:start position:0% +broadcast right Bob's like I can do six +or five + + align:start position:0% +or five + + + align:start position:0% +or five +Alice can only broadcast five but Alice + + align:start position:0% +Alice can only broadcast five but Alice + + + align:start position:0% +Alice can only broadcast five but Alice +knows that Bob can broadcast six right + + align:start position:0% +knows that Bob can broadcast six right + + + align:start position:0% +knows that Bob can broadcast six right +so Alice is also like well I'm not sure + + align:start position:0% +so Alice is also like well I'm not sure + + + align:start position:0% +so Alice is also like well I'm not sure +which it is if it's if I if you know + + align:start position:0% +which it is if it's if I if you know + + + align:start position:0% +which it is if it's if I if you know +from Alice's perspective if I close I'm + + align:start position:0% +from Alice's perspective if I close I'm + + + align:start position:0% +from Alice's perspective if I close I'm +gonna stay five if Bob closes he's at + + align:start position:0% +gonna stay five if Bob closes he's at + + + align:start position:0% +gonna stay five if Bob closes he's at +state six and then at state two Alice + + align:start position:0% +state six and then at state two Alice + + + align:start position:0% +state six and then at state two Alice +can only broadcast state six but Bob can + + align:start position:0% +can only broadcast state six but Bob can + + + align:start position:0% +can only broadcast state six but Bob can +broadcast sorry Alice can broadcast + + align:start position:0% +broadcast sorry Alice can broadcast + + + align:start position:0% +broadcast sorry Alice can broadcast +either but Bob can only broadcast one so + + align:start position:0% +either but Bob can only broadcast one so + + + align:start position:0% +either but Bob can only broadcast one so +yet during this process there's sort of + + align:start position:0% +yet during this process there's sort of + + + align:start position:0% +yet during this process there's sort of +it's not clear which state it is and you + + align:start position:0% +it's not clear which state it is and you + + + align:start position:0% +it's not clear which state it is and you +know if something happens like you know + + align:start position:0% +know if something happens like you know + + + align:start position:0% +know if something happens like you know +Bob goes offline you know Alice sends + + align:start position:0% +Bob goes offline you know Alice sends + + + align:start position:0% +Bob goes offline you know Alice sends +SIG's signature for six and Bob goes + + align:start position:0% +SIG's signature for six and Bob goes + + + align:start position:0% +SIG's signature for six and Bob goes +offline then it's like okay I never got + + align:start position:0% +offline then it's like okay I never got + + + align:start position:0% +offline then it's like okay I never got +a response I'll just try to close at + + align:start position:0% +a response I'll just try to close at + + + align:start position:0% +a response I'll just try to close at +state five I guess right and then I + + align:start position:0% +state five I guess right and then I + + + align:start position:0% +state five I guess right and then I +guess that payment never went through + + align:start position:0% +guess that payment never went through + + + align:start position:0% +guess that payment never went through +but then Bob could say no I got it and + + align:start position:0% +but then Bob could say no I got it and + + + align:start position:0% +but then Bob could say no I got it and +broadcast it like so that you know + + align:start position:0% +broadcast it like so that you know + + + align:start position:0% +broadcast it like so that you know +things can get weird where you're not + + align:start position:0% +things can get weird where you're not + + + align:start position:0% +things can get weird where you're not +really sure what happens here so like + + align:start position:0% +really sure what happens here so like + + + align:start position:0% +really sure what happens here so like +it's more a UI issue where in the UI + + align:start position:0% +it's more a UI issue where in the UI + + + align:start position:0% +it's more a UI issue where in the UI +like only show things after you get to + + align:start position:0% +like only show things after you get to + + + align:start position:0% +like only show things after you get to +the end hopefully in most cases this + + align:start position:0% +the end hopefully in most cases this + + + align:start position:0% +the end hopefully in most cases this +whole process takes a fraction of a + + align:start position:0% +whole process takes a fraction of a + + + align:start position:0% +whole process takes a fraction of a +second right because you're just sending + + align:start position:0% +second right because you're just sending + + + align:start position:0% +second right because you're just sending +some messages to each other so that's + + align:start position:0% +some messages to each other so that's + + + align:start position:0% +some messages to each other so that's +the nice part that's sort of the + + align:start position:0% +the nice part that's sort of the + + + align:start position:0% +the nice part that's sort of the +Lightning II thing is fast + + align:start position:0% +Lightning II thing is fast + + + align:start position:0% +Lightning II thing is fast +right + + align:start position:0% + + + + align:start position:0% + +Yeah right so they they're sending + + align:start position:0% +Yeah right so they they're sending + + + align:start position:0% +Yeah right so they they're sending +messages to each other they can't they + + align:start position:0% +messages to each other they can't they + + + align:start position:0% +messages to each other they can't they +can't really pre-compute these things + + align:start position:0% +can't really pre-compute these things + + + align:start position:0% +can't really pre-compute these things +because they don't know how much money + + align:start position:0% +because they don't know how much money + + + align:start position:0% +because they don't know how much money +is getting sent back and forth right so + + align:start position:0% +is getting sent back and forth right so + + + align:start position:0% +is getting sent back and forth right so +so when you're signing state six you're + + align:start position:0% +so when you're signing state six you're + + + align:start position:0% +so when you're signing state six you're +also signing the the value the output + + align:start position:0% +also signing the the value the output + + + align:start position:0% +also signing the the value the output +values and when Bob receives state six + + align:start position:0% +values and when Bob receives state six + + + align:start position:0% +values and when Bob receives state six +and signs his version of state six he + + align:start position:0% +and signs his version of state six he + + + align:start position:0% +and signs his version of state six he +also is like you know I don't know how + + align:start position:0% +also is like you know I don't know how + + + align:start position:0% +also is like you know I don't know how +much money I'm getting yet so I need to + + align:start position:0% +much money I'm getting yet so I need to + + + align:start position:0% +much money I'm getting yet so I need to +sign off on that + + align:start position:0% +sign off on that + + + align:start position:0% +sign off on that +so yeah both parties need to be online + + align:start position:0% +so yeah both parties need to be online + + + align:start position:0% +so yeah both parties need to be online +to receive which is different than + + align:start position:0% +to receive which is different than + + + align:start position:0% +to receive which is different than +normal in Bitcoin that's the same as + + align:start position:0% +normal in Bitcoin that's the same as + + + align:start position:0% +normal in Bitcoin that's the same as +that's the same as the unidirectional + + align:start position:0% +that's the same as the unidirectional + + + align:start position:0% +that's the same as the unidirectional +payment channels in the unidirectional + + align:start position:0% +payment channels in the unidirectional + + + align:start position:0% +payment channels in the unidirectional +one will were Bob the receiver he + + align:start position:0% +one will were Bob the receiver he + + + align:start position:0% +one will were Bob the receiver he +doesn't have to sign but he still has to + + align:start position:0% +doesn't have to sign but he still has to + + + align:start position:0% +doesn't have to sign but he still has to +be online because the the transaction + + align:start position:0% +be online because the the transaction + + + align:start position:0% +be online because the the transaction +just goes directly to him it doesn't go + + align:start position:0% +just goes directly to him it doesn't go + + + align:start position:0% +just goes directly to him it doesn't go +on to the blockchain right none of these + + align:start position:0% +on to the blockchain right none of these + + + align:start position:0% +on to the blockchain right none of these +are publicly known okay yes well what if + + align:start position:0% +are publicly known okay yes well what if + + + align:start position:0% +are publicly known okay yes well what if +what if you know this was state one + + align:start position:0% +what if you know this was state one + + + align:start position:0% +what if you know this was state one +right where Alice had one and bob had + + align:start position:0% +right where Alice had one and bob had + + + align:start position:0% +right where Alice had one and bob had +nine and then state you keep going and + + align:start position:0% +nine and then state you keep going and + + + align:start position:0% +nine and then state you keep going and +Bob keep in general the general trend is + + align:start position:0% +Bob keep in general the general trend is + + + align:start position:0% +Bob keep in general the general trend is +Bob's losing money right Bob's okay you + + align:start position:0% +Bob's losing money right Bob's okay you + + + align:start position:0% +Bob's losing money right Bob's okay you +know you go back and forth but at the + + align:start position:0% +know you go back and forth but at the + + + align:start position:0% +know you go back and forth but at the +end bob has one Bob needs to worry that + + align:start position:0% +end bob has one Bob needs to worry that + + + align:start position:0% +end bob has one Bob needs to worry that +Alice holds on to state one and then + + align:start position:0% +Alice holds on to state one and then + + + align:start position:0% +Alice holds on to state one and then +months later broadcasts it while Bob's + + align:start position:0% +months later broadcasts it while Bob's + + + align:start position:0% +months later broadcasts it while Bob's +not watching and then there's no right + + align:start position:0% +not watching and then there's no right + + + align:start position:0% +not watching and then there's no right +way no opposite Alice has to worry about + + align:start position:0% +way no opposite Alice has to worry about + + + align:start position:0% +way no opposite Alice has to worry about +Bob broadcasting state one in the future + + align:start position:0% +Bob broadcasting state one in the future + + + align:start position:0% +Bob broadcasting state one in the future +right but so you still need to keep the + + align:start position:0% +right but so you still need to keep the + + + align:start position:0% +right but so you still need to keep the +secret though it's revoked but that + + align:start position:0% +secret though it's revoked but that + + + align:start position:0% +secret though it's revoked but that +reveil the whole process of revocation + + align:start position:0% +reveil the whole process of revocation + + + align:start position:0% +reveil the whole process of revocation +is Bob gives a key to Alice + + align:start position:0% +is Bob gives a key to Alice + + + align:start position:0% +is Bob gives a key to Alice +so if Bob forgets that key then sorry if + + align:start position:0% +so if Bob forgets that key then sorry if + + + align:start position:0% +so if Bob forgets that key then sorry if +Alice forgets this key Bob can broadcast + + align:start position:0% +Alice forgets this key Bob can broadcast + + + align:start position:0% +Alice forgets this key Bob can broadcast +it and then Alice can't grab it yeah + + align:start position:0% +it and then Alice can't grab it yeah + + + align:start position:0% +it and then Alice can't grab it yeah +they can broadcast yeah they can anyone + + align:start position:0% +they can broadcast yeah they can anyone + + + align:start position:0% +they can broadcast yeah they can anyone +can brought so from the network's + + align:start position:0% +can brought so from the network's + + + align:start position:0% +can brought so from the network's +perspective these are all equally valid + + align:start position:0% +perspective these are all equally valid + + + align:start position:0% +perspective these are all equally valid +the network has no idea which came when + + align:start position:0% +the network has no idea which came when + + + align:start position:0% +the network has no idea which came when +and or anything like that the only way + + align:start position:0% +and or anything like that the only way + + + align:start position:0% +and or anything like that the only way +you enforce it is you know Bob broadcast + + align:start position:0% +you enforce it is you know Bob broadcast + + + align:start position:0% +you enforce it is you know Bob broadcast +this alice is like oh I'm taking this + + align:start position:0% +this alice is like oh I'm taking this + + + align:start position:0% +this alice is like oh I'm taking this +fund cuz I have the key so that's that's + + align:start position:0% +fund cuz I have the key so that's that's + + + align:start position:0% +fund cuz I have the key so that's that's +also a + + align:start position:0% +also a + + + align:start position:0% +also a +you know a pretty significant different + + align:start position:0% +you know a pretty significant different + + + align:start position:0% +you know a pretty significant different +security model it's a it's a security + + align:start position:0% +security model it's a it's a security + + + align:start position:0% +security model it's a it's a security +reduction right now you have to actively + + align:start position:0% +reduction right now you have to actively + + + align:start position:0% +reduction right now you have to actively +defend your channel because you if + + align:start position:0% +defend your channel because you if + + + align:start position:0% +defend your channel because you if +you're if you go offline I'm Alice I'm + + align:start position:0% +you're if you go offline I'm Alice I'm + + + align:start position:0% +you're if you go offline I'm Alice I'm +supposed to have nine coins I go on + + align:start position:0% +supposed to have nine coins I go on + + + align:start position:0% +supposed to have nine coins I go on +vacation I turn off my computer and Bob + + align:start position:0% +vacation I turn off my computer and Bob + + + align:start position:0% +vacation I turn off my computer and Bob +knows I've turned off my computer then + + align:start position:0% +knows I've turned off my computer then + + + align:start position:0% +knows I've turned off my computer then +I'll you know Bob can say Oh Alice is + + align:start position:0% +I'll you know Bob can say Oh Alice is + + + align:start position:0% +I'll you know Bob can say Oh Alice is +out like this this 100 block delay she's + + align:start position:0% +out like this this 100 block delay she's + + + align:start position:0% +out like this this 100 block delay she's +not gonna be online I'm just gonna + + align:start position:0% +not gonna be online I'm just gonna + + + align:start position:0% +not gonna be online I'm just gonna +broadcast this get the nine coins wait a + + align:start position:0% +broadcast this get the nine coins wait a + + + align:start position:0% +broadcast this get the nine coins wait a +hundred blocks and then you know sweep + + align:start position:0% +hundred blocks and then you know sweep + + + align:start position:0% +hundred blocks and then you know sweep +them as soon as I can + + align:start position:0% +them as soon as I can + + + align:start position:0% +them as soon as I can +and then Alice comes back plugs in and + + align:start position:0% +and then Alice comes back plugs in and + + + align:start position:0% +and then Alice comes back plugs in and +it's like oh you were wait no I + + align:start position:0% +it's like oh you were wait no I + + + align:start position:0% +it's like oh you were wait no I +oh it says I lost eight coins what + + align:start position:0% +oh it says I lost eight coins what + + + align:start position:0% +oh it says I lost eight coins what +because broad Bob defrauded so you have + + align:start position:0% +because broad Bob defrauded so you have + + + align:start position:0% +because broad Bob defrauded so you have +to be online I'm not I think I'm gonna + + align:start position:0% +to be online I'm not I think I'm gonna + + + align:start position:0% +to be online I'm not I think I'm gonna +get into it next time there's a way to + + align:start position:0% +get into it next time there's a way to + + + align:start position:0% +get into it next time there's a way to +outsource that so that you don't have to + + align:start position:0% +outsource that so that you don't have to + + + align:start position:0% +outsource that so that you don't have to +be watching you can have someone else + + align:start position:0% +be watching you can have someone else + + + align:start position:0% +be watching you can have someone else +watch for you and I'll probably talk + + align:start position:0% +watch for you and I'll probably talk + + + align:start position:0% +watch for you and I'll probably talk +about that next time but in the last 20 + + align:start position:0% +about that next time but in the last 20 + + + align:start position:0% +about that next time but in the last 20 +minutes yeah so this is cool right this + + align:start position:0% +minutes yeah so this is cool right this + + + align:start position:0% +minutes yeah so this is cool right this +is light network channels to parties + + align:start position:0% +is light network channels to parties + + + align:start position:0% +is light network channels to parties +indefinite you still need to create a + + align:start position:0% +indefinite you still need to create a + + + align:start position:0% +indefinite you still need to create a +channel to pay people so you just do one + + align:start position:0% +channel to pay people so you just do one + + + align:start position:0% +channel to pay people so you just do one +on chain transaction to open the channel + + align:start position:0% +on chain transaction to open the channel + + + align:start position:0% +on chain transaction to open the channel +wanted to close the channel potentially + + align:start position:0% +wanted to close the channel potentially + + + align:start position:0% +wanted to close the channel potentially +two to close the channel but that's + + align:start position:0% +two to close the channel but that's + + + align:start position:0% +two to close the channel but that's +pretty rare right if you need to + + align:start position:0% +pretty rare right if you need to + + + align:start position:0% +pretty rare right if you need to +immediately grab it then you're time + + align:start position:0% +immediately grab it then you're time + + + align:start position:0% +immediately grab it then you're time +sensitive and you're gonna have to + + align:start position:0% +sensitive and you're gonna have to + + + align:start position:0% +sensitive and you're gonna have to +closing transactions if you closed + + align:start position:0% +closing transactions if you closed + + + align:start position:0% +closing transactions if you closed +normally like you close the current + + align:start position:0% +normally like you close the current + + + align:start position:0% +normally like you close the current +state you need to wait a hundred blocks + + align:start position:0% +state you need to wait a hundred blocks + + + align:start position:0% +state you need to wait a hundred blocks +for your money to be active but you + + align:start position:0% +for your money to be active but you + + + align:start position:0% +for your money to be active but you +don't have to spend it immediately after + + align:start position:0% +don't have to spend it immediately after + + + align:start position:0% +don't have to spend it immediately after +that you can just leave it because you + + align:start position:0% +that you can just leave it because you + + + align:start position:0% +that you can just leave it because you +know so so in this case let's say this + + align:start position:0% +know so so in this case let's say this + + + align:start position:0% +know so so in this case let's say this +is Bob's Held's transaction Bob + + align:start position:0% +is Bob's Held's transaction Bob + + + align:start position:0% +is Bob's Held's transaction Bob +broadcasts it Bob knows okay Alice gets + + align:start position:0% +broadcasts it Bob knows okay Alice gets + + + align:start position:0% +broadcasts it Bob knows okay Alice gets +her two coins I get my eight coins I + + align:start position:0% +her two coins I get my eight coins I + + + align:start position:0% +her two coins I get my eight coins I +have to wait a hundred blocks but I + + align:start position:0% +have to wait a hundred blocks but I + + + align:start position:0% +have to wait a hundred blocks but I +don't actually have to spend it after a + + align:start position:0% +don't actually have to spend it after a + + + align:start position:0% +don't actually have to spend it after a +hundred blocks I can just leave it in my + + align:start position:0% +hundred blocks I can just leave it in my + + + align:start position:0% +hundred blocks I can just leave it in my +wallet because Bob knows he never gave + + align:start position:0% +wallet because Bob knows he never gave + + + align:start position:0% +wallet because Bob knows he never gave +Alice this key so this this clause this + + align:start position:0% +Alice this key so this this clause this + + + align:start position:0% +Alice this key so this this clause this +or Alice and Bob are key it's just not + + align:start position:0% +or Alice and Bob are key it's just not + + + align:start position:0% +or Alice and Bob are key it's just not +gonna happen so Bob safe and just like + + align:start position:0% +gonna happen so Bob safe and just like + + + align:start position:0% +gonna happen so Bob safe and just like +leaves it so he doesn't meet you know he + + align:start position:0% +leaves it so he doesn't meet you know he + + + align:start position:0% +leaves it so he doesn't meet you know he +can just use that as well however if + + align:start position:0% +can just use that as well however if + + + align:start position:0% +can just use that as well however if +it's the like no you + + align:start position:0% +it's the like no you + + + align:start position:0% +it's the like no you +kind of thing then you have to do two + + align:start position:0% +kind of thing then you have to do two + + + align:start position:0% +kind of thing then you have to do two +transactions that's Rhoda so this is + + align:start position:0% +transactions that's Rhoda so this is + + + align:start position:0% +transactions that's Rhoda so this is +pretty good but you still have to do two + + align:start position:0% +pretty good but you still have to do two + + + align:start position:0% +pretty good but you still have to do two +transactions so if you use this you open + + align:start position:0% +transactions so if you use this you open + + + align:start position:0% +transactions so if you use this you open +a channel you use it once and then you + + align:start position:0% +a channel you use it once and then you + + + align:start position:0% +a channel you use it once and then you +close it well that was dumb you just + + align:start position:0% +close it well that was dumb you just + + + align:start position:0% +close it well that was dumb you just +paid twice as much on in fees that you + + align:start position:0% +paid twice as much on in fees that you + + + align:start position:0% +paid twice as much on in fees that you +needed to so it's useful for some things + + align:start position:0% +needed to so it's useful for some things + + + align:start position:0% +needed to so it's useful for some things +not for others could we do something + + align:start position:0% +not for others could we do something + + + align:start position:0% +not for others could we do something +like multiple party channels so there's + + align:start position:0% +like multiple party channels so there's + + + align:start position:0% +like multiple party channels so there's +research about this it gets real ugly + + align:start position:0% +research about this it gets real ugly + + + align:start position:0% +research about this it gets real ugly +real fast like I want a single channel + + align:start position:0% +real fast like I want a single channel + + + align:start position:0% +real fast like I want a single channel +with like three or four users or like a + + align:start position:0% +with like three or four users or like a + + + align:start position:0% +with like three or four users or like a +tree of channels where the first top you + + align:start position:0% +tree of channels where the first top you + + + align:start position:0% +tree of channels where the first top you +know output has 404 multi-sig and then + + align:start position:0% +know output has 404 multi-sig and then + + + align:start position:0% +know output has 404 multi-sig and then +it branches into these two of two multi + + align:start position:0% +it branches into these two of two multi + + + align:start position:0% +it branches into these two of two multi +six there's a lot of interesting ideas + + align:start position:0% +six there's a lot of interesting ideas + + + align:start position:0% +six there's a lot of interesting ideas +but it gets a little ugly so like the + + align:start position:0% +but it gets a little ugly so like the + + + align:start position:0% +but it gets a little ugly so like the +off chain scalability gets bad there's + + align:start position:0% +off chain scalability gets bad there's + + + align:start position:0% +off chain scalability gets bad there's +like a lot of N squared kind of stuff so + + align:start position:0% +like a lot of N squared kind of stuff so + + + align:start position:0% +like a lot of N squared kind of stuff so +what about a forwarding network of + + align:start position:0% +what about a forwarding network of + + + align:start position:0% +what about a forwarding network of +point-to-point channels so okay if we + + align:start position:0% +point-to-point channels so okay if we + + + align:start position:0% +point-to-point channels so okay if we +have these two party channels and people + + align:start position:0% +have these two party channels and people + + + align:start position:0% +have these two party channels and people +are connected with them so Alice and Bob + + align:start position:0% +are connected with them so Alice and Bob + + + align:start position:0% +are connected with them so Alice and Bob +have a channel and Bob and Carol have a + + align:start position:0% +have a channel and Bob and Carol have a + + + align:start position:0% +have a channel and Bob and Carol have a +channel so this would be cool Alice can + + align:start position:0% +channel so this would be cool Alice can + + + align:start position:0% +channel so this would be cool Alice can +just say hey Bob I will pay you if you + + align:start position:0% +just say hey Bob I will pay you if you + + + align:start position:0% +just say hey Bob I will pay you if you +pay Carol and you can do that right + + align:start position:0% +pay Carol and you can do that right + + + align:start position:0% +pay Carol and you can do that right +Alice says look I'm just making a new + + align:start position:0% +Alice says look I'm just making a new + + + align:start position:0% +Alice says look I'm just making a new +state where you have an extra coin now + + align:start position:0% +state where you have an extra coin now + + + align:start position:0% +state where you have an extra coin now +please give this extra going to Carol + + align:start position:0% +please give this extra going to Carol + + + align:start position:0% +please give this extra going to Carol +and Bob says yeah okay it does so the + + align:start position:0% +and Bob says yeah okay it does so the + + + align:start position:0% +and Bob says yeah okay it does so the +the the word there that should have + + align:start position:0% +the the word there that should have + + + align:start position:0% +the the word there that should have +immediately raised like oh no that's not + + align:start position:0% +immediately raised like oh no that's not + + + align:start position:0% +immediately raised like oh no that's not +how this stuff works is the word please + + align:start position:0% +how this stuff works is the word please + + + align:start position:0% +how this stuff works is the word please +you don't say please in Bitcoin uh so + + align:start position:0% +you don't say please in Bitcoin uh so + + + align:start position:0% +you don't say please in Bitcoin uh so +yeah the other option is Bob just keeps + + align:start position:0% +yeah the other option is Bob just keeps + + + align:start position:0% +yeah the other option is Bob just keeps +it right so Alice says okay here I'll + + align:start position:0% +it right so Alice says okay here I'll + + + align:start position:0% +it right so Alice says okay here I'll +you know add a coin to your output in + + align:start position:0% +you know add a coin to your output in + + + align:start position:0% +you know add a coin to your output in +this in this channel and please add a + + align:start position:0% +this in this channel and please add a + + + align:start position:0% +this in this channel and please add a +coin to Carol's output in your channel + + align:start position:0% +coin to Carol's output in your channel + + + align:start position:0% +coin to Carol's output in your channel +with her and Bob says yeah no I'm just + + align:start position:0% +with her and Bob says yeah no I'm just + + + align:start position:0% +with her and Bob says yeah no I'm just +gonna keep the coin thanks if your trust + + align:start position:0% +gonna keep the coin thanks if your trust + + + align:start position:0% +gonna keep the coin thanks if your trust +so this this might not be super crazy in + + align:start position:0% +so this this might not be super crazy in + + + align:start position:0% +so this this might not be super crazy in +that well you've got a channel with them + + align:start position:0% +that well you've got a channel with them + + + align:start position:0% +that well you've got a channel with them +maybe they're merchants also you can you + + align:start position:0% +maybe they're merchants also you can you + + + align:start position:0% +maybe they're merchants also you can you +can reduce the number of coins you send + + align:start position:0% +can reduce the number of coins you send + + + align:start position:0% +can reduce the number of coins you send +per update right you can say look I'm + + align:start position:0% +per update right you can say look I'm + + + align:start position:0% +per update right you can say look I'm +gonna send like one Satoshi at a time + + align:start position:0% +gonna send like one Satoshi at a time + + + align:start position:0% +gonna send like one Satoshi at a time +and so worst case you keep one Satoshi + + align:start position:0% +and so worst case you keep one Satoshi + + + align:start position:0% +and so worst case you keep one Satoshi +that you shouldn't have right you could + + align:start position:0% +that you shouldn't have right you could + + + align:start position:0% +that you shouldn't have right you could +write it's + + align:start position:0% +write it's + + + align:start position:0% +write it's +it's not a scalable though because let's + + align:start position:0% +it's not a scalable though because let's + + + align:start position:0% +it's not a scalable though because let's +say you want to send a lot of money to + + align:start position:0% +say you want to send a lot of money to + + + align:start position:0% +say you want to send a lot of money to +Carol okay you're gonna have to keep + + align:start position:0% +Carol okay you're gonna have to keep + + + align:start position:0% +Carol okay you're gonna have to keep +doing these little things it's kind of + + align:start position:0% +doing these little things it's kind of + + + align:start position:0% +doing these little things it's kind of +annoying also what if you want multiple + + align:start position:0% +annoying also what if you want multiple + + + align:start position:0% +annoying also what if you want multiple +hops where you're not even sure who's in + + align:start position:0% +hops where you're not even sure who's in + + + align:start position:0% +hops where you're not even sure who's in +the middle of your over your chain it + + align:start position:0% +the middle of your over your chain it + + + align:start position:0% +the middle of your over your chain it +doesn't work for that okay so you can + + align:start position:0% +doesn't work for that okay so you can + + + align:start position:0% +doesn't work for that okay so you can +have what's called HDFC's and these more + + align:start position:0% +have what's called HDFC's and these more + + + align:start position:0% +have what's called HDFC's and these more +complicated okay + + align:start position:0% +complicated okay + + + align:start position:0% +complicated okay +so the idea is it's hash time locked + + align:start position:0% +so the idea is it's hash time locked + + + align:start position:0% +so the idea is it's hash time locked +contract or a hex time walk contract + + align:start position:0% +contract or a hex time walk contract + + + align:start position:0% +contract or a hex time walk contract +whatever the script is essentially this + + align:start position:0% +whatever the script is essentially this + + + align:start position:0% +whatever the script is essentially this +key a and preimage are you need to + + align:start position:0% +key a and preimage are you need to + + + align:start position:0% +key a and preimage are you need to +present a pre-image of a hash or a key B + + align:start position:0% +present a pre-image of a hash or a key B + + + align:start position:0% +present a pre-image of a hash or a key B +and some absolute lock time check lock + + align:start position:0% +and some absolute lock time check lock + + + align:start position:0% +and some absolute lock time check lock +time verify it and it's it's important + + align:start position:0% +time verify it and it's it's important + + + align:start position:0% +time verify it and it's it's important +that this is an absolute time not a + + align:start position:0% +that this is an absolute time not a + + + align:start position:0% +that this is an absolute time not a +relative time because these should be + + align:start position:0% +relative time because these should be + + + align:start position:0% +relative time because these should be +able to expire regardless of when they + + align:start position:0% +able to expire regardless of when they + + + align:start position:0% +able to expire regardless of when they +get broadcast on to the blockchain so + + align:start position:0% +get broadcast on to the blockchain so + + + align:start position:0% +get broadcast on to the blockchain so +the idea is in this case Alice so let's + + align:start position:0% +the idea is in this case Alice so let's + + + align:start position:0% +the idea is in this case Alice so let's +say a is Alice B's Bob Alice gets the + + align:start position:0% +say a is Alice B's Bob Alice gets the + + + align:start position:0% +say a is Alice B's Bob Alice gets the +money if she knows this preimage are + + align:start position:0% +money if she knows this preimage are + + + align:start position:0% +money if she knows this preimage are +this 32 byte you know so what actually + + align:start position:0% +this 32 byte you know so what actually + + + align:start position:0% +this 32 byte you know so what actually +goes here is the hash of our right it's + + align:start position:0% +goes here is the hash of our right it's + + + align:start position:0% +goes here is the hash of our right it's +like it's like a pay to pub key hash + + align:start position:0% +like it's like a pay to pub key hash + + + align:start position:0% +like it's like a pay to pub key hash +where you say up you know up hash 160 up + + align:start position:0% +where you say up you know up hash 160 up + + + align:start position:0% +where you say up you know up hash 160 up +do pop hash 160 the thing people verify + + align:start position:0% +do pop hash 160 the thing people verify + + + align:start position:0% +do pop hash 160 the thing people verify +so you need to know some preimage and + + align:start position:0% +so you need to know some preimage and + + + align:start position:0% +so you need to know some preimage and +you need to sign or you can be Bob and + + align:start position:0% +you need to sign or you can be Bob and + + + align:start position:0% +you need to sign or you can be Bob and +then you can sign after a certain you + + align:start position:0% +then you can sign after a certain you + + + align:start position:0% +then you can sign after a certain you +know after a certain date so the way you + + align:start position:0% +know after a certain date so the way you + + + align:start position:0% +know after a certain date so the way you +build these so this is kind of nice it's + + align:start position:0% +build these so this is kind of nice it's + + + align:start position:0% +build these so this is kind of nice it's +like well if R is known then it's + + align:start position:0% +like well if R is known then it's + + + align:start position:0% +like well if R is known then it's +Alice's money if R is unknown then it's + + align:start position:0% +Alice's money if R is unknown then it's + + + align:start position:0% +Alice's money if R is unknown then it's +Bob's money after a certain period of + + align:start position:0% +Bob's money after a certain period of + + + align:start position:0% +Bob's money after a certain period of +time okay + + align:start position:0% +time okay + + + align:start position:0% +time okay +so this was the revocable transaction + + align:start position:0% +so this was the revocable transaction + + + align:start position:0% +so this was the revocable transaction +right where okay Alice got two coins + + align:start position:0% +right where okay Alice got two coins + + + align:start position:0% +right where okay Alice got two coins +Bob's got eight coins and then you add a + + align:start position:0% +Bob's got eight coins and then you add a + + + align:start position:0% +Bob's got eight coins and then you add a +third output this hdl-c output we're + + align:start position:0% +third output this hdl-c output we're + + + align:start position:0% +third output this hdl-c output we're +okay now Alice has two coins Bob has + + align:start position:0% +okay now Alice has two coins Bob has + + + align:start position:0% +okay now Alice has two coins Bob has +seven coins and Alice might be getting + + align:start position:0% +seven coins and Alice might be getting + + + align:start position:0% +seven coins and Alice might be getting +an extra coin if she learns our Bob gets + + align:start position:0% +an extra coin if she learns our Bob gets + + + align:start position:0% +an extra coin if she learns our Bob gets +the coin back after height 500,000 right + + align:start position:0% +the coin back after height 500,000 right + + + align:start position:0% +the coin back after height 500,000 right +so this is this similar to like when + + align:start position:0% +so this is this similar to like when + + + align:start position:0% +so this is this similar to like when +this is like okay this is Bob's money + + align:start position:0% +this is like okay this is Bob's money + + + align:start position:0% +this is like okay this is Bob's money +but if he does something bad Alice can + + align:start position:0% +but if he does something bad Alice can + + + align:start position:0% +but if he does something bad Alice can +grab it + + align:start position:0% +grab it + + + align:start position:0% +grab it +this is not + + align:start position:0% +this is not + + + align:start position:0% +this is not +this is this is Alice's money if she + + align:start position:0% +this is this is Alice's money if she + + + align:start position:0% +this is this is Alice's money if she +knows our if she doesn't Bob gets it + + align:start position:0% +knows our if she doesn't Bob gets it + + + align:start position:0% +knows our if she doesn't Bob gets it +back so there's no like mallet Liam this + + align:start position:0% +back so there's no like mallet Liam this + + + align:start position:0% +back so there's no like mallet Liam this +is sort of like really this is Bob's + + align:start position:0% +is sort of like really this is Bob's + + + align:start position:0% +is sort of like really this is Bob's +money right this only happens if + + align:start position:0% +money right this only happens if + + + align:start position:0% +money right this only happens if +something Horrible's you know someone's + + align:start position:0% +something Horrible's you know someone's + + + align:start position:0% +something Horrible's you know someone's +trying to rip someone off this on the + + align:start position:0% +trying to rip someone off this on the + + + align:start position:0% +trying to rip someone off this on the +other hand is well depends + + align:start position:0% +other hand is well depends + + + align:start position:0% +other hand is well depends +does Alice gonna learn our or not and + + align:start position:0% +does Alice gonna learn our or not and + + + align:start position:0% +does Alice gonna learn our or not and +what is our okay so the multi-party + + align:start position:0% +what is our okay so the multi-party + + + align:start position:0% +what is our okay so the multi-party +adversarial payment model so the + + align:start position:0% +adversarial payment model so the + + + align:start position:0% +adversarial payment model so the +lightning forwarding is Alice wants to + + align:start position:0% +lightning forwarding is Alice wants to + + + align:start position:0% +lightning forwarding is Alice wants to +pay Carol right she doesn't want to just + + align:start position:0% +pay Carol right she doesn't want to just + + + align:start position:0% +pay Carol right she doesn't want to just +ask Bob to keep forwarding the funds + + align:start position:0% +ask Bob to keep forwarding the funds + + + align:start position:0% +ask Bob to keep forwarding the funds +because she doesn't trust Bob so she + + align:start position:0% +because she doesn't trust Bob so she + + + align:start position:0% +because she doesn't trust Bob so she +connects to Carol and by connect I mean + + align:start position:0% +connects to Carol and by connect I mean + + + align:start position:0% +connects to Carol and by connect I mean +like regular TCP connection and says hey + + align:start position:0% +like regular TCP connection and says hey + + + align:start position:0% +like regular TCP connection and says hey +Carol make a random number R and send me + + align:start position:0% +Carol make a random number R and send me + + + align:start position:0% +Carol make a random number R and send me +the hash codes okay here you go + + align:start position:0% +the hash codes okay here you go + + + align:start position:0% +the hash codes okay here you go +Carol knows H which is the the hash and + + align:start position:0% +Carol knows H which is the the hash and + + + align:start position:0% +Carol knows H which is the the hash and +R which is the pretty much she sends + + align:start position:0% +R which is the pretty much she sends + + + align:start position:0% +R which is the pretty much she sends +over H to Alice Alice then says to Bob + + align:start position:0% +over H to Alice Alice then says to Bob + + + align:start position:0% +over H to Alice Alice then says to Bob +hey I'm going to add an HDL C to our our + + align:start position:0% +hey I'm going to add an HDL C to our our + + + align:start position:0% +hey I'm going to add an HDL C to our our +Channel so basically Bob if you know the + + align:start position:0% +Channel so basically Bob if you know the + + + align:start position:0% +Channel so basically Bob if you know the +preimage of h if you know R you can get + + align:start position:0% +preimage of h if you know R you can get + + + align:start position:0% +preimage of h if you know R you can get +this coin if not I get the coin back + + align:start position:0% +this coin if not I get the coin back + + + align:start position:0% +this coin if not I get the coin back +after five o'clock and then Bob says + + align:start position:0% +after five o'clock and then Bob says + + + align:start position:0% +after five o'clock and then Bob says +okay cool + + align:start position:0% +okay cool + + + align:start position:0% +okay cool +I know H now but I don't know R so I + + align:start position:0% +I know H now but I don't know R so I + + + align:start position:0% +I know H now but I don't know R so I +can't I can't grab this money right I + + align:start position:0% +can't I can't grab this money right I + + + align:start position:0% +can't I can't grab this money right I +don't know this so there's no way this + + align:start position:0% +don't know this so there's no way this + + + align:start position:0% +don't know this so there's no way this +is gonna be my money it's just gonna go + + align:start position:0% +is gonna be my money it's just gonna go + + + align:start position:0% +is gonna be my money it's just gonna go +back to you after five and Alice says + + align:start position:0% +back to you after five and Alice says + + + align:start position:0% +back to you after five and Alice says +yeah but you know Carol knows are so ask + + align:start position:0% +yeah but you know Carol knows are so ask + + + align:start position:0% +yeah but you know Carol knows are so ask +Carol + + align:start position:0% +Carol + + + align:start position:0% +Carol +Bob says okay I get it I will forward + + align:start position:0% +Bob says okay I get it I will forward + + + align:start position:0% +Bob says okay I get it I will forward +this on to Carol and then I create a + + align:start position:0% +this on to Carol and then I create a + + + align:start position:0% +this on to Carol and then I create a +similar output I make sure that these + + align:start position:0% +similar output I make sure that these + + + align:start position:0% +similar output I make sure that these +are the same R or the same H I don't + + align:start position:0% +are the same R or the same H I don't + + + align:start position:0% +are the same R or the same H I don't +know why yet but I say hey Carol if you + + align:start position:0% +know why yet but I say hey Carol if you + + + align:start position:0% +know why yet but I say hey Carol if you +know R if you know the preimage of H you + + align:start position:0% +know R if you know the preimage of H you + + + align:start position:0% +know R if you know the preimage of H you +can get this coin if not after four + + align:start position:0% +can get this coin if not after four + + + align:start position:0% +can get this coin if not after four +o'clock I get the money back and then + + align:start position:0% +o'clock I get the money back and then + + + align:start position:0% +o'clock I get the money back and then +Carol says oh cool + + align:start position:0% +Carol says oh cool + + + align:start position:0% +Carol says oh cool +well guess what I know R because I made + + align:start position:0% +well guess what I know R because I made + + + align:start position:0% +well guess what I know R because I made +up made made are up and I can + + align:start position:0% +up made made are up and I can + + + align:start position:0% +up made made are up and I can +so from careless perspective Carol could + + align:start position:0% +so from careless perspective Carol could + + + align:start position:0% +so from careless perspective Carol could +broadcast this on to the blockchain + + align:start position:0% +broadcast this on to the blockchain + + + align:start position:0% +broadcast this on to the blockchain +immediately and she will be able to grab + + align:start position:0% +immediately and she will be able to grab + + + align:start position:0% +immediately and she will be able to grab +the money right cuz she knows our she + + align:start position:0% +the money right cuz she knows our she + + + align:start position:0% +the money right cuz she knows our she +has to grab it soon because by 4 o'clock + + align:start position:0% +has to grab it soon because by 4 o'clock + + + align:start position:0% +has to grab it soon because by 4 o'clock +Bob can grab the money better than + + align:start position:0% +Bob can grab the money better than + + + align:start position:0% +Bob can grab the money better than +closing that + + align:start position:0% +closing that + + + align:start position:0% +closing that +and if carol if Carol does this she + + align:start position:0% +and if carol if Carol does this she + + + align:start position:0% +and if carol if Carol does this she +closes the channel she uses our because + + align:start position:0% +closes the channel she uses our because + + + align:start position:0% +closes the channel she uses our because +she knows it to take this coin from this + + align:start position:0% +she knows it to take this coin from this + + + align:start position:0% +she knows it to take this coin from this +output Carol doing that will reveal art + + align:start position:0% +output Carol doing that will reveal art + + + align:start position:0% +output Carol doing that will reveal art +to everyone in the world because it's on + + align:start position:0% +to everyone in the world because it's on + + + align:start position:0% +to everyone in the world because it's on +the blockchain now + + align:start position:0% +the blockchain now + + + align:start position:0% +the blockchain now +and so then Alice or certain that Bob + + align:start position:0% +and so then Alice or certain that Bob + + + align:start position:0% +and so then Alice or certain that Bob +can say ah I know R now I need to get + + align:start position:0% +can say ah I know R now I need to get + + + align:start position:0% +can say ah I know R now I need to get +this money so Bob can close the channel + + align:start position:0% +this money so Bob can close the channel + + + align:start position:0% +this money so Bob can close the channel +grab the money yes this offer yeah we + + align:start position:0% +grab the money yes this offer yeah we + + + align:start position:0% +grab the money yes this offer yeah we +use Heights you could do a time the the + + align:start position:0% +use Heights you could do a time the the + + + align:start position:0% +use Heights you could do a time the the +reason we the main reason for Heights is + + align:start position:0% +reason we the main reason for Heights is + + + align:start position:0% +reason we the main reason for Heights is +what if a blocks full and like height + + align:start position:0% +what if a blocks full and like height + + + align:start position:0% +what if a blocks full and like height +height seems because Heights sort of + + align:start position:0% +height seems because Heights sort of + + + align:start position:0% +height seems because Heights sort of +variable like maybe a bunch of blocks + + align:start position:0% +variable like maybe a bunch of blocks + + + align:start position:0% +variable like maybe a bunch of blocks +come out quickly maybe they come out + + align:start position:0% +come out quickly maybe they come out + + + align:start position:0% +come out quickly maybe they come out +slowly so time is a little dangerous in + + align:start position:0% +slowly so time is a little dangerous in + + + align:start position:0% +slowly so time is a little dangerous in +that you could say okay four o'clock but + + align:start position:0% +that you could say okay four o'clock but + + + align:start position:0% +that you could say okay four o'clock but +maybe in the next five hours only a + + align:start position:0% +maybe in the next five hours only a + + + align:start position:0% +maybe in the next five hours only a +couple blocks come out just by chance + + align:start position:0% +couple blocks come out just by chance + + + align:start position:0% +couple blocks come out just by chance +and they're full and you're not able to + + align:start position:0% +and they're full and you're not able to + + + align:start position:0% +and they're full and you're not able to +broadcast you know and you're not able + + align:start position:0% +broadcast you know and you're not able + + + align:start position:0% +broadcast you know and you're not able +to get this in then it's risky so the + + align:start position:0% +to get this in then it's risky so the + + + align:start position:0% +to get this in then it's risky so the +height sort of takes into account the + + align:start position:0% +height sort of takes into account the + + + align:start position:0% +height sort of takes into account the +variable nature of it a little bit + + align:start position:0% +variable nature of it a little bit + + + align:start position:0% +variable nature of it a little bit +better yeah well page for parent yeah so + + align:start position:0% +better yeah well page for parent yeah so + + + align:start position:0% +better yeah well page for parent yeah so +the question is well you know what if + + align:start position:0% +the question is well you know what if + + + align:start position:0% +the question is well you know what if +the fees get really high right what if + + align:start position:0% +the fees get really high right what if + + + align:start position:0% +the fees get really high right what if +these the thing is this whole process + + align:start position:0% +these the thing is this whole process + + + align:start position:0% +these the thing is this whole process +should take a few seconds so it's not + + align:start position:0% +should take a few seconds so it's not + + + align:start position:0% +should take a few seconds so it's not +like these outputs are have have weird + + align:start position:0% +like these outputs are have have weird + + + align:start position:0% +like these outputs are have have weird +fees that are like old right one that + + align:start position:0% +fees that are like old right one that + + + align:start position:0% +fees that are like old right one that +one issue is what if you're building + + align:start position:0% +one issue is what if you're building + + + align:start position:0% +one issue is what if you're building +these states back and forth and then you + + align:start position:0% +these states back and forth and then you + + + align:start position:0% +these states back and forth and then you +sit on one for a few weeks and then the + + align:start position:0% +sit on one for a few weeks and then the + + + align:start position:0% +sit on one for a few weeks and then the +fee rate goes way up and you're like + + align:start position:0% +fee rate goes way up and you're like + + + align:start position:0% +fee rate goes way up and you're like +shoot if I try to broadcast these + + align:start position:0% +shoot if I try to broadcast these + + + align:start position:0% +shoot if I try to broadcast these +transactions the fees too low and it + + align:start position:0% +transactions the fees too low and it + + + align:start position:0% +transactions the fees too low and it +might not get confirmed that's not it's + + align:start position:0% +might not get confirmed that's not it's + + + align:start position:0% +might not get confirmed that's not it's +not a huge risk because if you're not + + align:start position:0% +not a huge risk because if you're not + + + align:start position:0% +not a huge risk because if you're not +trying to rip people off you don't + + align:start position:0% +trying to rip people off you don't + + + align:start position:0% +trying to rip people off you don't +actually have any time risk in this case + + align:start position:0% +actually have any time risk in this case + + + align:start position:0% +actually have any time risk in this case +these this gets built this get spill + + align:start position:0% +these this gets built this get spill + + + align:start position:0% +these this gets built this get spill +these are sort of in real time and so + + align:start position:0% +these are sort of in real time and so + + + align:start position:0% +these are sort of in real time and so +you know what the fee rate is in the + + align:start position:0% +you know what the fee rate is in the + + + align:start position:0% +you know what the fee rate is in the +network so you can see can adapt to it + + align:start position:0% +network so you can see can adapt to it + + + align:start position:0% +network so you can see can adapt to it +but yeah that's not sure yeah + + align:start position:0% + + + + align:start position:0% + +if some you know if you have like a + + align:start position:0% +if some you know if you have like a + + + align:start position:0% +if some you know if you have like a +number of nodes you mean a minimal + + align:start position:0% +number of nodes you mean a minimal + + + align:start position:0% +number of nodes you mean a minimal +number like + + align:start position:0% + + + + align:start position:0% + +don't need global consensus in that I + + align:start position:0% +don't need global consensus in that I + + + align:start position:0% +don't need global consensus in that I +didn't I did the only three so it you + + align:start position:0% +didn't I did the only three so it you + + + align:start position:0% +didn't I did the only three so it you +can't show if you have four you can sort + + align:start position:0% +can't show if you have four you can sort + + + align:start position:0% +can't show if you have four you can sort +of say let's say you have Alice Bob + + align:start position:0% +of say let's say you have Alice Bob + + + align:start position:0% +of say let's say you have Alice Bob +Carol Dave um Carol doesn't it like you + + align:start position:0% +Carol Dave um Carol doesn't it like you + + + align:start position:0% +Carol Dave um Carol doesn't it like you +don't actually have to know the whole + + align:start position:0% +don't actually have to know the whole + + + align:start position:0% +don't actually have to know the whole +thing you just have to know the person + + align:start position:0% +thing you just have to know the person + + + align:start position:0% +thing you just have to know the person +before you in the person after you you + + align:start position:0% +before you in the person after you you + + + align:start position:0% +before you in the person after you you +don't care what the actual end points + + align:start position:0% +don't care what the actual end points + + + align:start position:0% +don't care what the actual end points +are so to some extent Bob doesn't need + + align:start position:0% +are so to some extent Bob doesn't need + + + align:start position:0% +are so to some extent Bob doesn't need +to know maybe Alice got this hdl-c + + align:start position:0% +to know maybe Alice got this hdl-c + + + align:start position:0% +to know maybe Alice got this hdl-c +forwarded from someone else before and + + align:start position:0% +forwarded from someone else before and + + + align:start position:0% +forwarded from someone else before and +Bob's like all I know is Alice's you + + align:start position:0% +Bob's like all I know is Alice's you + + + align:start position:0% +Bob's like all I know is Alice's you +know I could get money from Alice I know + + align:start position:0% +know I could get money from Alice I know + + + align:start position:0% +know I could get money from Alice I know +R and Carol gets it for me if she knows + + align:start position:0% +R and Carol gets it for me if she knows + + + align:start position:0% +R and Carol gets it for me if she knows +R and if maybe that keeps going or + + align:start position:0% +R and if maybe that keeps going or + + + align:start position:0% +R and if maybe that keeps going or +something + + align:start position:0% +something + + + align:start position:0% +something +you don't need global consensus for this + + align:start position:0% + + + + align:start position:0% + +yeah yeah you don't all you're all + + align:start position:0% +yeah yeah you don't all you're all + + + align:start position:0% +yeah yeah you don't all you're all +you're only concerned with the channels + + align:start position:0% +you're only concerned with the channels + + + align:start position:0% +you're only concerned with the channels +you're participating in if there's + + align:start position:0% +you're participating in if there's + + + align:start position:0% +you're participating in if there's +something else happening before it you + + align:start position:0% +something else happening before it you + + + align:start position:0% +something else happening before it you +might want to watch in case our shows up + + align:start position:0% +might want to watch in case our shows up + + + align:start position:0% +might want to watch in case our shows up +but you know you don't have to worry + + align:start position:0% +but you know you don't have to worry + + + align:start position:0% +but you know you don't have to worry +about it + + align:start position:0% +about it + + + align:start position:0% +about it +and then like these along get broadcast + + align:start position:0% +and then like these along get broadcast + + + align:start position:0% +and then like these along get broadcast +you know the sort of failure mode is + + align:start position:0% +you know the sort of failure mode is + + + align:start position:0% +you know the sort of failure mode is +broadcast everything onto the blockchain + + align:start position:0% +broadcast everything onto the blockchain + + + align:start position:0% +broadcast everything onto the blockchain +and let the blockchain sorted out and + + align:start position:0% +and let the blockchain sorted out and + + + align:start position:0% +and let the blockchain sorted out and +that's you know that's very highly and C + + align:start position:0% +that's you know that's very highly and C + + + align:start position:0% +that's you know that's very highly and C +because it's like ten minutes but the + + align:start position:0% +because it's like ten minutes but the + + + align:start position:0% +because it's like ten minutes but the +blockchain you know the idea is the + + align:start position:0% +blockchain you know the idea is the + + + align:start position:0% +blockchain you know the idea is the +blockchain already has that global + + align:start position:0% +blockchain already has that global + + + align:start position:0% +blockchain already has that global +consensus because it's really low + + align:start position:0% +consensus because it's really low + + + align:start position:0% +consensus because it's really low +latency and everyone can agree on it so + + align:start position:0% +latency and everyone can agree on it so + + + align:start position:0% +latency and everyone can agree on it so +I think that's yeah so what you could do + + align:start position:0% +I think that's yeah so what you could do + + + align:start position:0% +I think that's yeah so what you could do +here is you can just close it right you + + align:start position:0% +here is you can just close it right you + + + align:start position:0% +here is you can just close it right you +could broadcast this whole transaction + + align:start position:0% +could broadcast this whole transaction + + + align:start position:0% +could broadcast this whole transaction +on the blockchain + + align:start position:0% +on the blockchain + + + align:start position:0% +on the blockchain +and get the payment through that's + + align:start position:0% +and get the payment through that's + + + align:start position:0% +and get the payment through that's +really inefficient you want to keep your + + align:start position:0% +really inefficient you want to keep your + + + align:start position:0% +really inefficient you want to keep your +channels open so what instead happens in + + align:start position:0% +channels open so what instead happens in + + + align:start position:0% +channels open so what instead happens in +in you know when everything's working + + align:start position:0% +in you know when everything's working + + + align:start position:0% +in you know when everything's working +the idea is it could happen right Carol + + align:start position:0% +the idea is it could happen right Carol + + + align:start position:0% +the idea is it could happen right Carol +could just broadcast it okay that's + + align:start position:0% +could just broadcast it okay that's + + + align:start position:0% +could just broadcast it okay that's +annoying whatever but no one loses money + + align:start position:0% +annoying whatever but no one loses money + + + align:start position:0% +annoying whatever but no one loses money +or Carol can go offline at this point + + align:start position:0% +or Carol can go offline at this point + + + align:start position:0% +or Carol can go offline at this point +and then these things get stuck you know + + align:start position:0% +and then these things get stuck you know + + + align:start position:0% +and then these things get stuck you know +there's all sorts of weird things that + + align:start position:0% +there's all sorts of weird things that + + + align:start position:0% +there's all sorts of weird things that +can go wrong you know lose money but + + align:start position:0% +can go wrong you know lose money but + + + align:start position:0% +can go wrong you know lose money but +what happens when things go right is + + align:start position:0% +what happens when things go right is + + + align:start position:0% +what happens when things go right is +Carol says hey um Bob I know are and so + + align:start position:0% +Carol says hey um Bob I know are and so + + + align:start position:0% +Carol says hey um Bob I know are and so +really this whole crazy hdl-c thing it's + + align:start position:0% +really this whole crazy hdl-c thing it's + + + align:start position:0% +really this whole crazy hdl-c thing it's +just my money right I know what R is + + align:start position:0% +just my money right I know what R is + + + align:start position:0% +just my money right I know what R is +you're never you're not getting this + + align:start position:0% +you're never you're not getting this + + + align:start position:0% +you're never you're not getting this +money + + align:start position:0% +money + + + align:start position:0% +money +at 4 o'clock because I know our so here + + align:start position:0% +at 4 o'clock because I know our so here + + + align:start position:0% +at 4 o'clock because I know our so here +look I'll tell you our and when Carol + + align:start position:0% +look I'll tell you our and when Carol + + + align:start position:0% +look I'll tell you our and when Carol +tells Bob our she's doing two things + + align:start position:0% +tells Bob our she's doing two things + + + align:start position:0% +tells Bob our she's doing two things +she's proving that this hdl-c is her + + align:start position:0% +she's proving that this hdl-c is her + + + align:start position:0% +she's proving that this hdl-c is her +money she's also giving Bob our so that + + align:start position:0% +money she's also giving Bob our so that + + + align:start position:0% +money she's also giving Bob our so that +he can then grab Alice's money and so as + + align:start position:0% +he can then grab Alice's money and so as + + + align:start position:0% +he can then grab Alice's money and so as +soon as she reveals our to Bob Bob says + + align:start position:0% +soon as she reveals our to Bob Bob says + + + align:start position:0% +soon as she reveals our to Bob Bob says +yeah I agree + + align:start position:0% +yeah I agree + + + align:start position:0% +yeah I agree +this hdl-c is superfluous at this point + + align:start position:0% +this hdl-c is superfluous at this point + + + align:start position:0% +this hdl-c is superfluous at this point +I know you know our so this is just your + + align:start position:0% +I know you know our so this is just your + + + align:start position:0% +I know you know our so this is just your +money and you know if it gets close to 4 + + align:start position:0% +money and you know if it gets close to 4 + + + align:start position:0% +money and you know if it gets close to 4 +o'clock I know you're gonna broadcast + + align:start position:0% +o'clock I know you're gonna broadcast + + + align:start position:0% +o'clock I know you're gonna broadcast +this channel onto the chain if I don't + + align:start position:0% +this channel onto the chain if I don't + + + align:start position:0% +this channel onto the chain if I don't +let you clear it out so let's just make + + align:start position:0% +let you clear it out so let's just make + + + align:start position:0% +let you clear it out so let's just make +a new state you know through these kind + + align:start position:0% +a new state you know through these kind + + + align:start position:0% +a new state you know through these kind +of state updates where you just have the + + align:start position:0% +of state updates where you just have the + + + align:start position:0% +of state updates where you just have the +extra money let's clear out that hdl-c + + align:start position:0% +extra money let's clear out that hdl-c + + + align:start position:0% +extra money let's clear out that hdl-c +so that one coin goes to you + + align:start position:0% +so that one coin goes to you + + + align:start position:0% +so that one coin goes to you +and goes like okay cool I agree we'll + + align:start position:0% +and goes like okay cool I agree we'll + + + align:start position:0% +and goes like okay cool I agree we'll +sign this and they let's get rid of the + + align:start position:0% +sign this and they let's get rid of the + + + align:start position:0% +sign this and they let's get rid of the +hdl-c output then Bob goes to Allison + + align:start position:0% +hdl-c output then Bob goes to Allison + + + align:start position:0% +hdl-c output then Bob goes to Allison +says hey Alice guess what I know R so + + align:start position:0% +says hey Alice guess what I know R so + + + align:start position:0% +says hey Alice guess what I know R so +this this part I'm gonna do it + + align:start position:0% +this this part I'm gonna do it + + + align:start position:0% +this this part I'm gonna do it +I know R and Bob this Alice after 5 + + align:start position:0% +I know R and Bob this Alice after 5 + + + align:start position:0% +I know R and Bob this Alice after 5 +o'clock it's not happening right if you + + align:start position:0% +o'clock it's not happening right if you + + + align:start position:0% +o'clock it's not happening right if you +if you stop if you stop answering me and + + align:start position:0% +if you stop if you stop answering me and + + + align:start position:0% +if you stop if you stop answering me and +it gets to like 4:30 I'm just gonna + + align:start position:0% +it gets to like 4:30 I'm just gonna + + + align:start position:0% +it gets to like 4:30 I'm just gonna +broadcast the the the channel on chain + + align:start position:0% +broadcast the the the channel on chain + + + align:start position:0% +broadcast the the the channel on chain +and grab it that way and then out Bob + + align:start position:0% +and grab it that way and then out Bob + + + align:start position:0% +and grab it that way and then out Bob +reveals our to Alice Alice's oh yeah you + + align:start position:0% +reveals our to Alice Alice's oh yeah you + + + align:start position:0% +reveals our to Alice Alice's oh yeah you +do no heart okay will clear the hdl-c + + align:start position:0% +do no heart okay will clear the hdl-c + + + align:start position:0% +do no heart okay will clear the hdl-c +out and you get the money and then Alice + + align:start position:0% +out and you get the money and then Alice + + + align:start position:0% +out and you get the money and then Alice +gets R and that sort of a receipt for + + align:start position:0% +gets R and that sort of a receipt for + + + align:start position:0% +gets R and that sort of a receipt for +the payment and Alice knows well carol + + align:start position:0% +the payment and Alice knows well carol + + + align:start position:0% +the payment and Alice knows well carol +was the one who told me h carol must + + align:start position:0% +was the one who told me h carol must + + + align:start position:0% +was the one who told me h carol must +have gotten the money right so that's my + + align:start position:0% +have gotten the money right so that's my + + + align:start position:0% +have gotten the money right so that's my +my confirmation of that + + align:start position:0% + + + + align:start position:0% + +oh so an input in the script but it's + + align:start position:0% +oh so an input in the script but it's + + + align:start position:0% +oh so an input in the script but it's +it's revocable the same way everything + + align:start position:0% +it's revocable the same way everything + + + align:start position:0% +it's revocable the same way everything +the the regular outputs are revocable + + align:start position:0% +the the regular outputs are revocable + + + align:start position:0% +the the regular outputs are revocable +there's also this you don't even have to + + align:start position:0% +there's also this you don't even have to + + + align:start position:0% +there's also this you don't even have to +do because the the idea is if the HDL + + align:start position:0% +do because the the idea is if the HDL + + + align:start position:0% +do because the the idea is if the HDL +sees are very small in comparison with + + align:start position:0% +sees are very small in comparison with + + + align:start position:0% +sees are very small in comparison with +the other outputs in the state that if + + align:start position:0% +the other outputs in the state that if + + + align:start position:0% +the other outputs in the state that if +you try to broadcast an old one you'll + + align:start position:0% +you try to broadcast an old one you'll + + + align:start position:0% +you try to broadcast an old one you'll +lose weigh more than the HDL see is + + align:start position:0% +lose weigh more than the HDL see is + + + align:start position:0% +lose weigh more than the HDL see is +worth but you can also tack on a or + + align:start position:0% +worth but you can also tack on a or + + + align:start position:0% +worth but you can also tack on a or +other Clause to the HDL C script with a + + align:start position:0% +other Clause to the HDL C script with a + + + align:start position:0% +other Clause to the HDL C script with a +relative lock time so there's actually a + + align:start position:0% +relative lock time so there's actually a + + + align:start position:0% +relative lock time so there's actually a +couple different ways to do it the + + align:start position:0% +couple different ways to do it the + + + align:start position:0% +couple different ways to do it the +simplest is you just say look the other + + align:start position:0% +simplest is you just say look the other + + + align:start position:0% +simplest is you just say look the other +the two you know I've got two coins + + align:start position:0% +the two you know I've got two coins + + + align:start position:0% +the two you know I've got two coins +eight coins or two point seven coins and + + align:start position:0% +eight coins or two point seven coins and + + + align:start position:0% +eight coins or two point seven coins and +then a one coin hdl-c I'm not gonna risk + + align:start position:0% +then a one coin hdl-c I'm not gonna risk + + + align:start position:0% +then a one coin hdl-c I'm not gonna risk +my seven coins to go back and try to get + + align:start position:0% +my seven coins to go back and try to get + + + align:start position:0% +my seven coins to go back and try to get +this one coin in the HLC but that's not + + align:start position:0% +this one coin in the HLC but that's not + + + align:start position:0% +this one coin in the HLC but that's not +how most of the software does it you + + align:start position:0% +how most of the software does it you + + + align:start position:0% +how most of the software does it you +just add a new clause okay so this is a + + align:start position:0% +just add a new clause okay so this is a + + + align:start position:0% +just add a new clause okay so this is a +multiple party adversarial so yeah that + + align:start position:0% +multiple party adversarial so yeah that + + + align:start position:0% +multiple party adversarial so yeah that +would be really useful right you you + + align:start position:0% +would be really useful right you you + + + align:start position:0% +would be really useful right you you +build lots of nodes with channels + + align:start position:0% +build lots of nodes with channels + + + align:start position:0% +build lots of nodes with channels +connecting and they form a big graph and + + align:start position:0% +connecting and they form a big graph and + + + align:start position:0% +connecting and they form a big graph and +then you can sort of request payment + + align:start position:0% +then you can sort of request payment + + + align:start position:0% +then you can sort of request payment +routing these these hdl-c outputs and if + + align:start position:0% +routing these these hdl-c outputs and if + + + align:start position:0% +routing these these hdl-c outputs and if +you open a few channels then you can pay + + align:start position:0% +you open a few channels then you can pay + + + align:start position:0% +you open a few channels then you can pay +lots of different users on the network + + align:start position:0% +lots of different users on the network + + + align:start position:0% +lots of different users on the network +yes Bob kid charged a fee or he could + + align:start position:0% +yes Bob kid charged a fee or he could + + + align:start position:0% +yes Bob kid charged a fee or he could +just be a nice guy + + align:start position:0% +just be a nice guy + + + align:start position:0% +just be a nice guy +that's basically the + + align:start position:0% + + + + align:start position:0% + +please yeah so yeah so you can pay him + + align:start position:0% +please yeah so yeah so you can pay him + + + align:start position:0% +please yeah so yeah so you can pay him +um it's gonna be hard to pay him much + + align:start position:0% +um it's gonna be hard to pay him much + + + align:start position:0% +um it's gonna be hard to pay him much +because alice is gonna say look we've + + align:start position:0% +because alice is gonna say look we've + + + align:start position:0% +because alice is gonna say look we've +got a channel we're using it if you + + align:start position:0% +got a channel we're using it if you + + + align:start position:0% +got a channel we're using it if you +charge me a ton to forward payments to + + align:start position:0% +charge me a ton to forward payments to + + + align:start position:0% +charge me a ton to forward payments to +Carol I'm just gonna close the channel + + align:start position:0% +Carol I'm just gonna close the channel + + + align:start position:0% +Carol I'm just gonna close the channel +and open with someone who does it + + align:start position:0% +and open with someone who does it + + + align:start position:0% +and open with someone who does it +cheaper so yeah you can you can make the + + align:start position:0% +cheaper so yeah you can you can make the + + + align:start position:0% +cheaper so yeah you can you can make the +amounts slightly less right so Allah + + align:start position:0% +amounts slightly less right so Allah + + + align:start position:0% +amounts slightly less right so Allah +says I'm sending you one coin and Bob + + align:start position:0% +says I'm sending you one coin and Bob + + + align:start position:0% +says I'm sending you one coin and Bob +says okay I'm sending 0.9999 coins to + + align:start position:0% +says okay I'm sending 0.9999 coins to + + + align:start position:0% +says okay I'm sending 0.9999 coins to +Carol and I'm keeping the difference he + + align:start position:0% +Carol and I'm keeping the difference he + + + align:start position:0% +Carol and I'm keeping the difference he +can have that and then it's really up to + + align:start position:0% +can have that and then it's really up to + + + align:start position:0% +can have that and then it's really up to +Carol to decide if the fee because Alice + + align:start position:0% +Carol to decide if the fee because Alice + + + align:start position:0% +Carol to decide if the fee because Alice +all Alice knows is hey I'm sending one + + align:start position:0% +all Alice knows is hey I'm sending one + + + align:start position:0% +all Alice knows is hey I'm sending one +coin and then Carol sees what if Bob + + align:start position:0% +coin and then Carol sees what if Bob + + + align:start position:0% +coin and then Carol sees what if Bob +puts a crazy fee like half a coin Carol + + align:start position:0% +puts a crazy fee like half a coin Carol + + + align:start position:0% +puts a crazy fee like half a coin Carol +sees 0.5 and Carol is like no I that's + + align:start position:0% +sees 0.5 and Carol is like no I that's + + + align:start position:0% +sees 0.5 and Carol is like no I that's +that's way too low I don't know what + + align:start position:0% +that's way too low I don't know what + + + align:start position:0% +that's way too low I don't know what +happened if Alice sent 0.5 and Bob + + align:start position:0% +happened if Alice sent 0.5 and Bob + + + align:start position:0% +happened if Alice sent 0.5 and Bob +forwarded it to me or if Alice sent one + + align:start position:0% +forwarded it to me or if Alice sent one + + + align:start position:0% +forwarded it to me or if Alice sent one +and Bob Ford went five but I'm not + + align:start position:0% +and Bob Ford went five but I'm not + + + align:start position:0% +and Bob Ford went five but I'm not +accepting this right I'm not gonna + + align:start position:0% +accepting this right I'm not gonna + + + align:start position:0% +accepting this right I'm not gonna +reveal our to you I'm just gonna say no + + align:start position:0% +reveal our to you I'm just gonna say no + + + align:start position:0% +reveal our to you I'm just gonna say no +so you can do that right at this point + + align:start position:0% +so you can do that right at this point + + + align:start position:0% +so you can do that right at this point +Carol has not yet revealed are Carol can + + align:start position:0% +Carol has not yet revealed are Carol can + + + align:start position:0% +Carol has not yet revealed are Carol can +refuse and say look at Bob I'm not gonna + + align:start position:0% +refuse and say look at Bob I'm not gonna + + + align:start position:0% +refuse and say look at Bob I'm not gonna +accept this gauge steel see we can just + + align:start position:0% +accept this gauge steel see we can just + + + align:start position:0% +accept this gauge steel see we can just +clear it out right away without + + align:start position:0% +clear it out right away without + + + align:start position:0% +clear it out right away without +revealing our and and just basically + + align:start position:0% +revealing our and and just basically + + + align:start position:0% +revealing our and and just basically +undo what we just did yeah two photos - + + align:start position:0% +undo what we just did yeah two photos - + + + align:start position:0% +undo what we just did yeah two photos - +that the first is can there be a + + align:start position:0% +that the first is can there be a + + + align:start position:0% +that the first is can there be a +situation where it's an efficient market + + align:start position:0% +situation where it's an efficient market + + + align:start position:0% +situation where it's an efficient market +place for these + + align:start position:0% + + + + align:start position:0% + +actually wins and she rots it from that + + align:start position:0% +actually wins and she rots it from that + + + align:start position:0% +actually wins and she rots it from that +you can so if let's say Alice is + + align:start position:0% +you can so if let's say Alice is + + + align:start position:0% +you can so if let's say Alice is +connected to like you know three three + + align:start position:0% +connected to like you know three three + + + align:start position:0% +connected to like you know three three +Bob's in the middle and then asks all of + + align:start position:0% +Bob's in the middle and then asks all of + + + align:start position:0% +Bob's in the middle and then asks all of +them hey what are you gonna charge me to + + align:start position:0% +them hey what are you gonna charge me to + + + align:start position:0% +them hey what are you gonna charge me to +forward a coin to Carol + + align:start position:0% +forward a coin to Carol + + + align:start position:0% +forward a coin to Carol +then they can all answer it's a little + + align:start position:0% +then they can all answer it's a little + + + align:start position:0% +then they can all answer it's a little +weird because they can they can lie at + + align:start position:0% +weird because they can they can lie at + + + align:start position:0% +weird because they can they can lie at +that point because I haven't actually + + align:start position:0% +that point because I haven't actually + + + align:start position:0% +that point because I haven't actually +like signed anything and this fob can + + align:start position:0% +like signed anything and this fob can + + + align:start position:0% +like signed anything and this fob can +say oh I'll do it for free and this Bob + + align:start position:0% +say oh I'll do it for free and this Bob + + + align:start position:0% +say oh I'll do it for free and this Bob +says I'll do it for half a coin into + + align:start position:0% +says I'll do it for half a coin into + + + align:start position:0% +says I'll do it for half a coin into +this bob says I'll do it a tenth of a + + align:start position:0% +this bob says I'll do it a tenth of a + + + align:start position:0% +this bob says I'll do it a tenth of a +coin and then you try to go for the free + + align:start position:0% +coin and then you try to go for the free + + + align:start position:0% +coin and then you try to go for the free +one and Carol gets like some really low + + align:start position:0% +one and Carol gets like some really low + + + align:start position:0% +one and Carol gets like some really low +amount and says I'm not telling you are + + align:start position:0% +amount and says I'm not telling you are + + + align:start position:0% +amount and says I'm not telling you are +let's let's cancel this and then you can + + align:start position:0% +let's let's cancel this and then you can + + + align:start position:0% +let's let's cancel this and then you can +if Alice trusts Carol Cael can be like + + align:start position:0% +if Alice trusts Carol Cael can be like + + + align:start position:0% +if Alice trusts Carol Cael can be like +Alice Bob just tried to charge a + + align:start position:0% +Alice Bob just tried to charge a + + + align:start position:0% +Alice Bob just tried to charge a +ridiculous fee don't use this you know + + align:start position:0% +ridiculous fee don't use this you know + + + align:start position:0% +ridiculous fee don't use this you know +this Bob is bad and then you try the + + align:start position:0% +this Bob is bad and then you try the + + + align:start position:0% +this Bob is bad and then you try the +other Bob and the other Bob does the + + align:start position:0% +other Bob and the other Bob does the + + + align:start position:0% +other Bob and the other Bob does the +right thing yeah open the channel so + + align:start position:0% +right thing yeah open the channel so + + + align:start position:0% +right thing yeah open the channel so +yeah you could you just have to open a + + align:start position:0% +yeah you could you just have to open a + + + align:start position:0% +yeah you could you just have to open a +channel yeah you have to go on chain so + + align:start position:0% +channel yeah you have to go on chain so + + + align:start position:0% +channel yeah you have to go on chain so +the idea is long term like it we sort of + + align:start position:0% +the idea is long term like it we sort of + + + align:start position:0% +the idea is long term like it we sort of +saw a preview of it in November December + + align:start position:0% +saw a preview of it in November December + + + align:start position:0% +saw a preview of it in November December +January where it was actually kind of + + align:start position:0% +January where it was actually kind of + + + align:start position:0% +January where it was actually kind of +expensive to use Bitcoin now it's cheap + + align:start position:0% +expensive to use Bitcoin now it's cheap + + + align:start position:0% +expensive to use Bitcoin now it's cheap +again costs a few cents but for a month + + align:start position:0% +again costs a few cents but for a month + + + align:start position:0% +again costs a few cents but for a month +or two it was like oh shoot like this + + align:start position:0% +or two it was like oh shoot like this + + + align:start position:0% +or two it was like oh shoot like this +costs like five bucks to make a chain on + + align:start position:0% +costs like five bucks to make a chain on + + + align:start position:0% +costs like five bucks to make a chain on +chain transaction and so like creating a + + align:start position:0% +chain transaction and so like creating a + + + align:start position:0% +chain transaction and so like creating a +new direct channel from Alice to Carol + + align:start position:0% +new direct channel from Alice to Carol + + + align:start position:0% +new direct channel from Alice to Carol +it might cost five bucks or it might + + align:start position:0% +it might cost five bucks or it might + + + align:start position:0% +it might cost five bucks or it might +cost twenty bucks or you know like long + + align:start position:0% +cost twenty bucks or you know like long + + + align:start position:0% +cost twenty bucks or you know like long +term if everyone's trying to use the + + align:start position:0% +term if everyone's trying to use the + + + align:start position:0% +term if everyone's trying to use the +blockchain and the fees go really high + + align:start position:0% +blockchain and the fees go really high + + + align:start position:0% +blockchain and the fees go really high +it could be kind of expensive and so the + + align:start position:0% +it could be kind of expensive and so the + + + align:start position:0% +it could be kind of expensive and so the +idea is well if I've got a channel + + align:start position:0% +idea is well if I've got a channel + + + align:start position:0% +idea is well if I've got a channel +already I'd rather use that and move my + + align:start position:0% +already I'd rather use that and move my + + + align:start position:0% +already I'd rather use that and move my +money around that way without having to + + align:start position:0% +money around that way without having to + + + align:start position:0% +money around that way without having to +like touch the blockchain yeah + + align:start position:0% + + + + align:start position:0% + +so scalability so like you can sort of + + align:start position:0% +so scalability so like you can sort of + + + align:start position:0% +so scalability so like you can sort of +so it's bone for it or it's like Jake's + + align:start position:0% +so it's bone for it or it's like Jake's + + + align:start position:0% +so it's bone for it or it's like Jake's +Torres kind of if you know the whole + + align:start position:0% +Torres kind of if you know the whole + + + align:start position:0% +Torres kind of if you know the whole +graph yeah well so that's one part is if + + align:start position:0% +graph yeah well so that's one part is if + + + align:start position:0% +graph yeah well so that's one part is if +you know the whole graph and you you can + + align:start position:0% +you know the whole graph and you you can + + + align:start position:0% +you know the whole graph and you you can +know the whole graph because the graph + + align:start position:0% +know the whole graph because the graph + + + align:start position:0% +know the whole graph because the graph +never gets bigger than the UT Exocet + + align:start position:0% +never gets bigger than the UT Exocet + + + align:start position:0% +never gets bigger than the UT Exocet +right every channel is a is a + + align:start position:0% +right every channel is a is a + + + align:start position:0% +right every channel is a is a +transaction output and so if you're + + align:start position:0% +transaction output and so if you're + + + align:start position:0% +transaction output and so if you're +running a full node and you have the + + align:start position:0% +running a full node and you have the + + + align:start position:0% +running a full node and you have the +whole UT Exocet well the entire graph is + + align:start position:0% +whole UT Exocet well the entire graph is + + + align:start position:0% +whole UT Exocet well the entire graph is +is on the order of that size so maybe + + align:start position:0% +is on the order of that size so maybe + + + align:start position:0% +is on the order of that size so maybe +it's twice as big I mean that you have + + align:start position:0% +it's twice as big I mean that you have + + + align:start position:0% +it's twice as big I mean that you have +to have some like extra metadata about + + align:start position:0% +to have some like extra metadata about + + + align:start position:0% +to have some like extra metadata about +what these outputs are and like Bob and + + align:start position:0% +what these outputs are and like Bob and + + + align:start position:0% +what these outputs are and like Bob and +Carol can make proofs they're like oh + + align:start position:0% +Carol can make proofs they're like oh + + + align:start position:0% +Carol can make proofs they're like oh +here's our channel and it's in the UT + + align:start position:0% +here's our channel and it's in the UT + + + align:start position:0% +here's our channel and it's in the UT +Exocet and we can sort of reveal our pop + + align:start position:0% +Exocet and we can sort of reveal our pop + + + align:start position:0% +Exocet and we can sort of reveal our pop +keys that they go in here so if you have + + align:start position:0% +keys that they go in here so if you have + + + align:start position:0% +keys that they go in here so if you have +the whole graph you can do some routing + + align:start position:0% +the whole graph you can do some routing + + + align:start position:0% +the whole graph you can do some routing +that's like n log n kind of speed but + + align:start position:0% +that's like n log n kind of speed but + + + align:start position:0% +that's like n log n kind of speed but +then it might not work and so that's the + + align:start position:0% +then it might not work and so that's the + + + align:start position:0% +then it might not work and so that's the +like so there's lots of ways there's + + align:start position:0% +like so there's lots of ways there's + + + align:start position:0% +like so there's lots of ways there's +there's actually tons of ways things can + + align:start position:0% +there's actually tons of ways things can + + + align:start position:0% +there's actually tons of ways things can +go wrong in this that's the sort of fun + + align:start position:0% +go wrong in this that's the sort of fun + + + align:start position:0% +go wrong in this that's the sort of fun +part of dealing with there's one of the + + align:start position:0% +part of dealing with there's one of the + + + align:start position:0% +part of dealing with there's one of the +ways it can it cannot work is you're + + align:start position:0% +ways it can it cannot work is you're + + + align:start position:0% +ways it can it cannot work is you're +like yeah I found a path the simplest is + + align:start position:0% +like yeah I found a path the simplest is + + + align:start position:0% +like yeah I found a path the simplest is +I found a path and I query Bob and Bob + + align:start position:0% +I found a path and I query Bob and Bob + + + align:start position:0% +I found a path and I query Bob and Bob +is just offline like oh okay well that's + + align:start position:0% +is just offline like oh okay well that's + + + align:start position:0% +is just offline like oh okay well that's +not an active path ok what's the second + + align:start position:0% +not an active path ok what's the second + + + align:start position:0% +not an active path ok what's the second +shortest fast ok this other Bob and and + + align:start position:0% +shortest fast ok this other Bob and and + + + align:start position:0% +shortest fast ok this other Bob and and +he says yes but the fee seems really + + align:start position:0% +he says yes but the fee seems really + + + align:start position:0% +he says yes but the fee seems really +high so ok I found the 30 so most of the + + align:start position:0% +high so ok I found the 30 so most of the + + + align:start position:0% +high so ok I found the 30 so most of the +algorithms though will will get you like + + align:start position:0% +algorithms though will will get you like + + + align:start position:0% +algorithms though will will get you like +the second and third and fourth and + + align:start position:0% +the second and third and fourth and + + + align:start position:0% +the second and third and fourth and +fifth shortest in much less time than + + align:start position:0% +fifth shortest in much less time than + + + align:start position:0% +fifth shortest in much less time than +recomputing the whole thing from scratch + + align:start position:0% +recomputing the whole thing from scratch + + + align:start position:0% +recomputing the whole thing from scratch +so you can get a you can get a bunch of + + align:start position:0% +so you can get a you can get a bunch of + + + align:start position:0% +so you can get a you can get a bunch of +pretty good ones and try them all by + + align:start position:0% +pretty good ones and try them all by + + + align:start position:0% +pretty good ones and try them all by +query and they're what + + align:start position:0% + + + + align:start position:0% + +yeah the thing is in practice it's all + + align:start position:0% +yeah the thing is in practice it's all + + + align:start position:0% +yeah the thing is in practice it's all +real fast right like there's well right + + align:start position:0% +real fast right like there's well right + + + align:start position:0% +real fast right like there's well right +now there's like you know for a small + + align:start position:0% +now there's like you know for a small + + + align:start position:0% +now there's like you know for a small +Network it's nothing but even total + + align:start position:0% +Network it's nothing but even total + + + align:start position:0% +Network it's nothing but even total +number of UT EXO's is on the order of + + align:start position:0% +number of UT EXO's is on the order of + + + align:start position:0% +number of UT EXO's is on the order of +like millions right so if you've got a + + align:start position:0% +like millions right so if you've got a + + + align:start position:0% +like millions right so if you've got a +graph with like millions of edges that's + + align:start position:0% +graph with like millions of edges that's + + + align:start position:0% +graph with like millions of edges that's +that's easy for a computer right they'll + + align:start position:0% +that's easy for a computer right they'll + + + align:start position:0% +that's easy for a computer right they'll +do it in like less than a second so and + + align:start position:0% +do it in like less than a second so and + + + align:start position:0% +do it in like less than a second so and +then you that your main thing here is + + align:start position:0% +then you that your main thing here is + + + align:start position:0% +then you that your main thing here is +network latency for all of these things + + align:start position:0% +network latency for all of these things + + + align:start position:0% +network latency for all of these things +for for building new states it's the the + + align:start position:0% +for for building new states it's the the + + + align:start position:0% +for for building new states it's the the +time taken for you know the data to get + + align:start position:0% +time taken for you know the data to get + + + align:start position:0% +time taken for you know the data to get +from one side of the other is much + + align:start position:0% +from one side of the other is much + + + align:start position:0% +from one side of the other is much +larger than computing the signatures + + align:start position:0% +larger than computing the signatures + + + align:start position:0% +larger than computing the signatures +verifying the signatures building the + + align:start position:0% +verifying the signatures building the + + + align:start position:0% +verifying the signatures building the +hash tree thing all that stuff is is + + align:start position:0% +hash tree thing all that stuff is is + + + align:start position:0% +hash tree thing all that stuff is is +real fast compared to network so same + + align:start position:0% +real fast compared to network so same + + + align:start position:0% +real fast compared to network so same +with routing looking at the look at the + + align:start position:0% +with routing looking at the look at the + + + align:start position:0% +with routing looking at the look at the +graph and detecting it is gonna be + + align:start position:0% +graph and detecting it is gonna be + + + align:start position:0% +graph and detecting it is gonna be +faster than contacting all the things + + align:start position:0% +faster than contacting all the things + + + align:start position:0% +faster than contacting all the things +there's a bunch of other things that can + + align:start position:0% +there's a bunch of other things that can + + + align:start position:0% +there's a bunch of other things that can +go wrong so for example this gets built + + align:start position:0% +go wrong so for example this gets built + + + align:start position:0% +go wrong so for example this gets built +you get to here and just Carol the stops + + align:start position:0% +you get to here and just Carol the stops + + + align:start position:0% +you get to here and just Carol the stops +responding right so now you've got these + + align:start position:0% +responding right so now you've got these + + + align:start position:0% +responding right so now you've got these +two HDL sees there there a third output + + align:start position:0% +two HDL sees there there a third output + + + align:start position:0% +two HDL sees there there a third output +in your channel transaction and Carol is + + align:start position:0% +in your channel transaction and Carol is + + + align:start position:0% +in your channel transaction and Carol is +just like not saying anything and then + + align:start position:0% +just like not saying anything and then + + + align:start position:0% +just like not saying anything and then +Alice goes to Bob it's like Bob what's + + align:start position:0% +Alice goes to Bob it's like Bob what's + + + align:start position:0% +Alice goes to Bob it's like Bob what's +up like we're gonna clear the stage teal + + align:start position:0% +up like we're gonna clear the stage teal + + + align:start position:0% +up like we're gonna clear the stage teal +see usually these only take a second and + + align:start position:0% +see usually these only take a second and + + + align:start position:0% +see usually these only take a second and +Bob's like oh yeah hold on and so it's + + align:start position:0% +Bob's like oh yeah hold on and so it's + + + align:start position:0% +Bob's like oh yeah hold on and so it's +kind of awkward right because now we've + + align:start position:0% +kind of awkward right because now we've + + + align:start position:0% +kind of awkward right because now we've +got the same she'll seen you don't know + + align:start position:0% +got the same she'll seen you don't know + + + align:start position:0% +got the same she'll seen you don't know +whose money it ends up being there's the + + align:start position:0% +whose money it ends up being there's the + + + align:start position:0% +whose money it ends up being there's the +way to mitigate that that rusty yeah I + + align:start position:0% +way to mitigate that that rusty yeah I + + + align:start position:0% +way to mitigate that that rusty yeah I +think it works + + align:start position:0% +think it works + + + align:start position:0% +think it works +Rusty's other guy who works on this + + align:start position:0% +Rusty's other guy who works on this + + + align:start position:0% +Rusty's other guy who works on this +stuff was that Alice were quite if he + + align:start position:0% +stuff was that Alice were quite if he + + + align:start position:0% +stuff was that Alice were quite if he +has like a timeout period I think 30 + + align:start position:0% +has like a timeout period I think 30 + + + align:start position:0% +has like a timeout period I think 30 +seconds a minute whatever where Alice + + align:start position:0% +seconds a minute whatever where Alice + + + align:start position:0% +seconds a minute whatever where Alice +says okay Bob I made this hdl-c a minute + + align:start position:0% +says okay Bob I made this hdl-c a minute + + + align:start position:0% +says okay Bob I made this hdl-c a minute +ago minutes up you need to either shut + + align:start position:0% +ago minutes up you need to either shut + + + align:start position:0% +ago minutes up you need to either shut +down this channel right now because + + align:start position:0% +down this channel right now because + + + align:start position:0% +down this channel right now because +you're doing something bad or you need + + align:start position:0% +you're doing something bad or you need + + + align:start position:0% +you're doing something bad or you need +to shut down you need to prove to me + + align:start position:0% +to shut down you need to prove to me + + + align:start position:0% +to shut down you need to prove to me +that a channel has been shut down with + + align:start position:0% +that a channel has been shut down with + + + align:start position:0% +that a channel has been shut down with +this hdl-c this h value in it and then I + + align:start position:0% +this hdl-c this h value in it and then I + + + align:start position:0% +this hdl-c this h value in it and then I +know where to ascribe blame + + align:start position:0% +know where to ascribe blame + + + align:start position:0% +know where to ascribe blame +so if Bob's like yeah I can't contact + + align:start position:0% +so if Bob's like yeah I can't contact + + + align:start position:0% +so if Bob's like yeah I can't contact +Carol Carol's offline the analysis all + + align:start position:0% +Carol Carol's offline the analysis all + + + align:start position:0% +Carol Carol's offline the analysis all +right well then shut down the channel + + align:start position:0% +right well then shut down the channel + + + align:start position:0% +right well then shut down the channel +right + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +so it's that's the downside right well + + align:start position:0% +so it's that's the downside right well + + + align:start position:0% +so it's that's the downside right well +thing is if you don't do that you can in + + align:start position:0% +thing is if you don't do that you can in + + + align:start position:0% +thing is if you don't do that you can in +this world it's like being live really + + align:start position:0% +this world it's like being live really + + + align:start position:0% +this world it's like being live really +matters okay + + align:start position:0% +matters okay + + + align:start position:0% +matters okay +true okay one thing to mitigate that the + + align:start position:0% +true okay one thing to mitigate that the + + + align:start position:0% +true okay one thing to mitigate that the +only time care this is this is a Carol + + align:start position:0% +only time care this is this is a Carol + + + align:start position:0% +only time care this is this is a Carol +responded by signing off on the hdl-c + + align:start position:0% +responded by signing off on the hdl-c + + + align:start position:0% +responded by signing off on the hdl-c +and then immediately goes offline like + + align:start position:0% +and then immediately goes offline like + + + align:start position:0% +and then immediately goes offline like +so you know it's it's not like you + + align:start position:0% +so you know it's it's not like you + + + align:start position:0% +so you know it's it's not like you +accident well part of the protocol is if + + align:start position:0% +accident well part of the protocol is if + + + align:start position:0% +accident well part of the protocol is if +you have an HD LC and you don't remove + + align:start position:0% +you have an HD LC and you don't remove + + + align:start position:0% +you have an HD LC and you don't remove +it within 30 to 60 seconds it's like you + + align:start position:0% +it within 30 to 60 seconds it's like you + + + align:start position:0% +it within 30 to 60 seconds it's like you +know that's that's a violation of the + + align:start position:0% +know that's that's a violation of the + + + align:start position:0% +know that's that's a violation of the +rules and we're gonna close your chant + + align:start position:0% +rules and we're gonna close your chant + + + align:start position:0% +rules and we're gonna close your chant +there channels because if you're just + + align:start position:0% +there channels because if you're just + + + align:start position:0% +there channels because if you're just +offline straight-up offline and it's + + align:start position:0% +offline straight-up offline and it's + + + align:start position:0% +offline straight-up offline and it's +like well okay I'm not going to use that + + align:start position:0% +like well okay I'm not going to use that + + + align:start position:0% +like well okay I'm not going to use that +channel but it's like oh I accepted this + + align:start position:0% +channel but it's like oh I accepted this + + + align:start position:0% +channel but it's like oh I accepted this +and immediately said okay I'm not + + align:start position:0% +and immediately said okay I'm not + + + align:start position:0% +and immediately said okay I'm not +talking you anymore and they're like + + align:start position:0% +talking you anymore and they're like + + + align:start position:0% +talking you anymore and they're like +well now it's stuck because the the sort + + align:start position:0% +well now it's stuck because the the sort + + + align:start position:0% +well now it's stuck because the the sort +of attack vector is build a ton of HDL + + align:start position:0% +of attack vector is build a ton of HDL + + + align:start position:0% +of attack vector is build a ton of HDL +C's right you could have multiple per + + align:start position:0% +C's right you could have multiple per + + + align:start position:0% +C's right you could have multiple per +channel + + align:start position:0% +channel + + + align:start position:0% +channel +and like build them all and they all get + + align:start position:0% +and like build them all and they all get + + + align:start position:0% +and like build them all and they all get +stuck and one party's just not + + align:start position:0% +stuck and one party's just not + + + align:start position:0% +stuck and one party's just not +responding with there are values and + + align:start position:0% +responding with there are values and + + + align:start position:0% +responding with there are values and +then everyone's like okay if we try to + + align:start position:0% +then everyone's like okay if we try to + + + align:start position:0% +then everyone's like okay if we try to +close our transactions now have like 100 + + align:start position:0% +close our transactions now have like 100 + + + align:start position:0% +close our transactions now have like 100 +outputs and they're huge and have all + + align:start position:0% +outputs and they're huge and have all + + + align:start position:0% +outputs and they're huge and have all +these fees also all these HDL sees yeah + + align:start position:0% +these fees also all these HDL sees yeah + + + align:start position:0% +these fees also all these HDL sees yeah +there might be really little and we have + + align:start position:0% +there might be really little and we have + + + align:start position:0% +there might be really little and we have +to like wait and then it charges a lot + + align:start position:0% +to like wait and then it charges a lot + + + align:start position:0% +to like wait and then it charges a lot +of fees to recover them and stuff so you + + align:start position:0% +of fees to recover them and stuff so you + + + align:start position:0% +of fees to recover them and stuff so you +don't you don't want people to be able + + align:start position:0% +don't you don't want people to be able + + + align:start position:0% +don't you don't want people to be able +to sort of bloat the number of HDL CS in + + align:start position:0% +to sort of bloat the number of HDL CS in + + + align:start position:0% +to sort of bloat the number of HDL CS in +your channels so the way to do it is + + align:start position:0% +your channels so the way to do it is + + + align:start position:0% +your channels so the way to do it is +okay if one of them stuck you need to + + align:start position:0% +okay if one of them stuck you need to + + + align:start position:0% +okay if one of them stuck you need to +find someone to blame and yeah it's it's + + align:start position:0% +find someone to blame and yeah it's it's + + + align:start position:0% +find someone to blame and yeah it's it's +possible right but but the thing is you + + align:start position:0% +possible right but but the thing is you + + + align:start position:0% +possible right but but the thing is you +you accurately find the person to blame + + align:start position:0% +you accurately find the person to blame + + + align:start position:0% +you accurately find the person to blame +if Carol accepts the HDL C and then a + + align:start position:0% +if Carol accepts the HDL C and then a + + + align:start position:0% +if Carol accepts the HDL C and then a +split second later unplugs their + + align:start position:0% +split second later unplugs their + + + align:start position:0% +split second later unplugs their +computer Bob's like wow okay fine I'm + + align:start position:0% +computer Bob's like wow okay fine I'm + + + align:start position:0% +computer Bob's like wow okay fine I'm +closing the channel you just did + + align:start position:0% +closing the channel you just did + + + align:start position:0% +closing the channel you just did +something really annoying and if I don't + + align:start position:0% +something really annoying and if I don't + + + align:start position:0% +something really annoying and if I don't +you know Bob's like if I don't close + + align:start position:0% +you know Bob's like if I don't close + + + align:start position:0% +you know Bob's like if I don't close +this channel Alice isn't gonna close the + + align:start position:0% +this channel Alice isn't gonna close the + + + align:start position:0% +this channel Alice isn't gonna close the +channel on me because alice is gonna + + align:start position:0% +channel on me because alice is gonna + + + align:start position:0% +channel on me because alice is gonna +think I'm the one acting weird so yeah + + align:start position:0% +think I'm the one acting weird so yeah + + + align:start position:0% +think I'm the one acting weird so yeah +there's there's all sorts of weird edge + + align:start position:0% +there's there's all sorts of weird edge + + + align:start position:0% +there's there's all sorts of weird edge +cases there's all sorts of weird stuff + + align:start position:0% +cases there's all sorts of weird stuff + + + align:start position:0% +cases there's all sorts of weird stuff +that could happen + + align:start position:0% +that could happen + + + align:start position:0% +that could happen +it's definitely more complicated than + + align:start position:0% +it's definitely more complicated than + + + align:start position:0% +it's definitely more complicated than +just the straight-up UTX I was in + + align:start position:0% +just the straight-up UTX I was in + + + align:start position:0% +just the straight-up UTX I was in +Bitcoin yes it was like couldn't counter + + align:start position:0% +Bitcoin yes it was like couldn't counter + + + align:start position:0% +Bitcoin yes it was like couldn't counter +will respond to bulb and then won't be + + align:start position:0% +will respond to bulb and then won't be + + + align:start position:0% +will respond to bulb and then won't be +malicious and close the channel and then + + align:start position:0% +malicious and close the channel and then + + + align:start position:0% +malicious and close the channel and then +say hey Alice yep + + align:start position:0% +say hey Alice yep + + + align:start position:0% +say hey Alice yep +it's okay Bob Bob blames Carol Carol + + align:start position:0% +it's okay Bob Bob blames Carol Carol + + + align:start position:0% +it's okay Bob Bob blames Carol Carol +says no was actually Bob from Alice's + + align:start position:0% +says no was actually Bob from Alice's + + + align:start position:0% +says no was actually Bob from Alice's +point of view like whatever like + + align:start position:0% +point of view like whatever like + + + align:start position:0% +point of view like whatever like +something got close there was a cost to + + align:start position:0% +something got close there was a cost to + + + align:start position:0% +something got close there was a cost to +adding this HT you know there was a cost + + align:start position:0% +adding this HT you know there was a cost + + + align:start position:0% +adding this HT you know there was a cost +to having me stuck with this hdl-c for + + align:start position:0% +to having me stuck with this hdl-c for + + + align:start position:0% +to having me stuck with this hdl-c for +five hours write something on chain + + align:start position:0% +five hours write something on chain + + + align:start position:0% +five hours write something on chain +happened so so like the thing is having + + align:start position:0% +happened so so like the thing is having + + + align:start position:0% +happened so so like the thing is having +one hdl-c stuck for a few hours it's no + + align:start position:0% +one hdl-c stuck for a few hours it's no + + + align:start position:0% +one hdl-c stuck for a few hours it's no +big deal + + align:start position:0% +big deal + + + align:start position:0% +big deal +after five o'clock Alice just goes to + + align:start position:0% +after five o'clock Alice just goes to + + + align:start position:0% +after five o'clock Alice just goes to +bombs like look well let's clear it + + align:start position:0% +bombs like look well let's clear it + + + align:start position:0% +bombs like look well let's clear it +right you don't know are you if you knew + + align:start position:0% +right you don't know are you if you knew + + + align:start position:0% +right you don't know are you if you knew +are you would have told me by now so + + align:start position:0% +are you would have told me by now so + + + align:start position:0% +are you would have told me by now so +let's just get rid of this thing and + + align:start position:0% +let's just get rid of this thing and + + + align:start position:0% +let's just get rid of this thing and +Bob's like yeah fine and they clear it + + align:start position:0% +Bob's like yeah fine and they clear it + + + align:start position:0% +Bob's like yeah fine and they clear it +out so the idea is it's it's not a big + + align:start position:0% +out so the idea is it's it's not a big + + + align:start position:0% +out so the idea is it's it's not a big +attack if you only have one of them it's + + align:start position:0% +attack if you only have one of them it's + + + align:start position:0% +attack if you only have one of them it's +a you want some cost to performing that + + align:start position:0% +a you want some cost to performing that + + + align:start position:0% +a you want some cost to performing that +and so if Bob closes the channel whether + + align:start position:0% +and so if Bob closes the channel whether + + + align:start position:0% +and so if Bob closes the channel whether +its kara's fault or Bob's fault + + align:start position:0% +its kara's fault or Bob's fault + + + align:start position:0% +its kara's fault or Bob's fault +alice is sort of like look well + + align:start position:0% +alice is sort of like look well + + + align:start position:0% +alice is sort of like look well +something happened so someone's bearing + + align:start position:0% +something happened so someone's bearing + + + align:start position:0% +something happened so someone's bearing +the cost for this so they're not going + + align:start position:0% +the cost for this so they're not going + + + align:start position:0% +the cost for this so they're not going +to keep doing it + + align:start position:0% + + + + align:start position:0% + +you needed he actually need hours + + align:start position:0% +you needed he actually need hours + + + align:start position:0% +you needed he actually need hours +because Oh other attack let's say this + + align:start position:0% +because Oh other attack let's say this + + + align:start position:0% +because Oh other attack let's say this +was for let's say these were both five + + align:start position:0% +was for let's say these were both five + + + align:start position:0% +was for let's say these were both five +o'clock right and then Carol closes the + + align:start position:0% +o'clock right and then Carol closes the + + + align:start position:0% +o'clock right and then Carol closes the +channel right at five o'clock grabs the + + align:start position:0% +channel right at five o'clock grabs the + + + align:start position:0% +channel right at five o'clock grabs the +you know right before five o'clock Carol + + align:start position:0% +you know right before five o'clock Carol + + + align:start position:0% +you know right before five o'clock Carol +grabs it you know close to the channel + + align:start position:0% +grabs it you know close to the channel + + + align:start position:0% +grabs it you know close to the channel +uses are grabs it Bob then says oh shoot + + align:start position:0% +uses are grabs it Bob then says oh shoot + + + align:start position:0% +uses are grabs it Bob then says oh shoot +there's our Alice is like no Alice + + align:start position:0% +there's our Alice is like no Alice + + + align:start position:0% +there's our Alice is like no Alice +closes the channel right it right after + + align:start position:0% +closes the channel right it right after + + + align:start position:0% +closes the channel right it right after +five and grabs her by by signing with + + align:start position:0% +five and grabs her by by signing with + + + align:start position:0% +five and grabs her by by signing with +her key and above Bob screwed right + + align:start position:0% +her key and above Bob screwed right + + + align:start position:0% +her key and above Bob screwed right +Bob's like shoot wait Carol just got the + + align:start position:0% +Bob's like shoot wait Carol just got the + + + align:start position:0% +Bob's like shoot wait Carol just got the +money from me using our and then Alice + + align:start position:0% +money from me using our and then Alice + + + align:start position:0% +money from me using our and then Alice +closes got the money for me using the + + align:start position:0% +closes got the money for me using the + + + align:start position:0% +closes got the money for me using the +time out and I didn't get anything right + + align:start position:0% +time out and I didn't get anything right + + + align:start position:0% +time out and I didn't get anything right +I lost the money on this side and I + + align:start position:0% +I lost the money on this side and I + + + align:start position:0% +I lost the money on this side and I +didn't get the money on this side so Bob + + align:start position:0% +didn't get the money on this side so Bob + + + align:start position:0% +didn't get the money on this side so Bob +just got Bob just had a huge loss there + + align:start position:0% +just got Bob just had a huge loss there + + + align:start position:0% +just got Bob just had a huge loss there +so Bob really wants to make sure that + + align:start position:0% +so Bob really wants to make sure that + + + align:start position:0% +so Bob really wants to make sure that +this is later like Alice can't get the + + align:start position:0% +this is later like Alice can't get the + + + align:start position:0% +this is later like Alice can't get the +money until well after Carol can get the + + align:start position:0% +money until well after Carol can get the + + + align:start position:0% +money until well after Carol can get the +money with the timeout function I'm + + align:start position:0% +money with the timeout function I'm + + + align:start position:0% +money with the timeout function I'm +sorry that well after Bob can get his + + align:start position:0% +sorry that well after Bob can get his + + + align:start position:0% +sorry that well after Bob can get his +money with the time yeah well they all + + align:start position:0% +money with the time yeah well they all + + + align:start position:0% +money with the time yeah well they all +hold on Bob sets this time yes and Alice + + align:start position:0% +hold on Bob sets this time yes and Alice + + + align:start position:0% +hold on Bob sets this time yes and Alice +sets this time + + align:start position:0% + + + + align:start position:0% + +yeah he has to make sure his is earlier + + align:start position:0% +yeah he has to make sure his is earlier + + + align:start position:0% +yeah he has to make sure his is earlier +and and continuing that right so if + + align:start position:0% +and and continuing that right so if + + + align:start position:0% +and and continuing that right so if +Carol opens a channel if Carol makes an + + align:start position:0% +Carol opens a channel if Carol makes an + + + align:start position:0% +Carol opens a channel if Carol makes an +HDL City today if she makes it at 3 + + align:start position:0% +HDL City today if she makes it at 3 + + + align:start position:0% +HDL City today if she makes it at 3 +o'clock or whatever I don't remember + + align:start position:0% +o'clock or whatever I don't remember + + + align:start position:0% +o'clock or whatever I don't remember +what the defaults are and the different + + align:start position:0% +what the defaults are and the different + + + align:start position:0% +what the defaults are and the different +like like I do it all on test net and so + + align:start position:0% +like like I do it all on test net and so + + + align:start position:0% +like like I do it all on test net and so +in test net I do like five blocks + + align:start position:0% +in test net I do like five blocks + + + align:start position:0% +in test net I do like five blocks +because who cares but I think in the + + align:start position:0% +because who cares but I think in the + + + align:start position:0% +because who cares but I think in the +main net ones people are trying out they + + align:start position:0% +main net ones people are trying out they + + + align:start position:0% +main net ones people are trying out they +do quite a bit more because it's better + + align:start position:0% +do quite a bit more because it's better + + + align:start position:0% +do quite a bit more because it's better +to have your money stuck for a day than + + align:start position:0% +to have your money stuck for a day than + + + align:start position:0% +to have your money stuck for a day than +to lose it I guess so so you can make + + align:start position:0% +to lose it I guess so so you can make + + + align:start position:0% +to lose it I guess so so you can make +different time outs and stuff like that + + align:start position:0% +different time outs and stuff like that + + + align:start position:0% +different time outs and stuff like that +okay + + align:start position:0% +okay + + + align:start position:0% +okay +what else I'm basically done there's a + + align:start position:0% +what else I'm basically done there's a + + + align:start position:0% +what else I'm basically done there's a +whole bunch of other cool things you can + + align:start position:0% +whole bunch of other cool things you can + + + align:start position:0% +whole bunch of other cool things you can +do it and I'll I think I'll talk about + + align:start position:0% +do it and I'll I think I'll talk about + + + align:start position:0% +do it and I'll I think I'll talk about +that next time yeah you can do cross + + align:start position:0% +that next time yeah you can do cross + + + align:start position:0% +that next time yeah you can do cross +chain swaps so this is preview of after + + align:start position:0% +chain swaps so this is preview of after + + + align:start position:0% +chain swaps so this is preview of after +great this channel and this channel do + + align:start position:0% +great this channel and this channel do + + + align:start position:0% +great this channel and this channel do +not need to be on the same blockchain + + align:start position:0% +not need to be on the same blockchain + + + align:start position:0% +not need to be on the same blockchain +totally fine for this to be Bitcoin has + + align:start position:0% +totally fine for this to be Bitcoin has + + + align:start position:0% +totally fine for this to be Bitcoin has +to be like coin or this to be dogecoin + + align:start position:0% +to be like coin or this to be dogecoin + + + align:start position:0% +to be like coin or this to be dogecoin +you know like it actually totally works + + align:start position:0% +you know like it actually totally works + + + align:start position:0% +you know like it actually totally works +so that's kind of cool security so you + + align:start position:0% +so that's kind of cool security so you + + + align:start position:0% +so that's kind of cool security so you +can monitor you want to monitor your + + align:start position:0% +can monitor you want to monitor your + + + align:start position:0% +can monitor you want to monitor your +channels in case someone tries to rip + + align:start position:0% +channels in case someone tries to rip + + + align:start position:0% +channels in case someone tries to rip +you off you can outsource that in a nice + + align:start position:0% +you off you can outsource that in a nice + + + align:start position:0% +you off you can outsource that in a nice +way where you give it to a third party + + align:start position:0% +way where you give it to a third party + + + align:start position:0% +way where you give it to a third party +and say hey I've got this channel watch + + align:start position:0% +and say hey I've got this channel watch + + + align:start position:0% +and say hey I've got this channel watch +it for me not only that I've got a + + align:start position:0% +it for me not only that I've got a + + + align:start position:0% +it for me not only that I've got a +channel watch it for me I'm not gonna + + align:start position:0% +channel watch it for me I'm not gonna + + + align:start position:0% +channel watch it for me I'm not gonna +tell you what channel it is how much + + align:start position:0% +tell you what channel it is how much + + + align:start position:0% +tell you what channel it is how much +money you have basically anything and + + align:start position:0% +money you have basically anything and + + + align:start position:0% +money you have basically anything and +you can still protect it for me so + + align:start position:0% +you can still protect it for me so + + + align:start position:0% +you can still protect it for me so +that's kind of cool you can anonymously + + align:start position:0% +that's kind of cool you can anonymously + + + align:start position:0% +that's kind of cool you can anonymously +view that stuff case she'll sees I just + + align:start position:0% +view that stuff case she'll sees I just + + + align:start position:0% +view that stuff case she'll sees I just +talked about dust and fees gets really + + align:start position:0% +talked about dust and fees gets really + + + align:start position:0% +talked about dust and fees gets really +ugly there's a lot of cool stuff you can + + align:start position:0% +ugly there's a lot of cool stuff you can + + + align:start position:0% +ugly there's a lot of cool stuff you can +do so I think that the schedule is I'll + + align:start position:0% +do so I think that the schedule is I'll + + + align:start position:0% +do so I think that the schedule is I'll +talk about the rest of lightning on + + align:start position:0% +talk about the rest of lightning on + + + align:start position:0% +talk about the rest of lightning on +Monday after Spring Break and then go + + align:start position:0% +Monday after Spring Break and then go + + + align:start position:0% +Monday after Spring Break and then go +into discrete log contracts which is + + align:start position:0% +into discrete log contracts which is + + + align:start position:0% +into discrete log contracts which is +another similar construction on the + + align:start position:0% +another similar construction on the + + + align:start position:0% +another similar construction on the +Wednesday after ok any questions about + + align:start position:0% +Wednesday after ok any questions about + + + align:start position:0% +Wednesday after ok any questions about +all this stuff + + align:start position:0% +all this stuff + + + align:start position:0% +all this stuff +I'm sure yeah + + align:start position:0% + + + + align:start position:0% + +miners miners Kim can make timeouts not + + align:start position:0% +miners miners Kim can make timeouts not + + + align:start position:0% +miners miners Kim can make timeouts not +happen right if there's a lot of if + + align:start position:0% +happen right if there's a lot of if + + + align:start position:0% +happen right if there's a lot of if +there's their coordinated they can say + + align:start position:0% +there's their coordinated they can say + + + align:start position:0% +there's their coordinated they can say +we're just gonna not accept this + + align:start position:0% +we're just gonna not accept this + + + align:start position:0% +we're just gonna not accept this +transaction till later so that's bad + + align:start position:0% +transaction till later so that's bad + + + align:start position:0% +transaction till later so that's bad +yeah there's a there's there's all other + + align:start position:0% +yeah there's a there's there's all other + + + align:start position:0% +yeah there's a there's there's all other +weird attack vectors the one that I + + align:start position:0% +weird attack vectors the one that I + + + align:start position:0% +weird attack vectors the one that I +worry about most not most the one that I + + align:start position:0% +worry about most not most the one that I + + + align:start position:0% +worry about most not most the one that I +worry about is if you make a backup of + + align:start position:0% +worry about is if you make a backup of + + + align:start position:0% +worry about is if you make a backup of +your wallet and you restore it you lose + + align:start position:0% +your wallet and you restore it you lose + + + align:start position:0% +your wallet and you restore it you lose +all your money so you make a backup here + + align:start position:0% +all your money so you make a backup here + + + align:start position:0% +all your money so you make a backup here +at state two onto your USB stick and you + + align:start position:0% +at state two onto your USB stick and you + + + align:start position:0% +at state two onto your USB stick and you +go home and you drop your laptop in the + + align:start position:0% +go home and you drop your laptop in the + + + align:start position:0% +go home and you drop your laptop in the +pool and you're like shoot well good + + align:start position:0% +pool and you're like shoot well good + + + align:start position:0% +pool and you're like shoot well good +thing I got my backup and then you were + + align:start position:0% +thing I got my backup and then you were + + + align:start position:0% +thing I got my backup and then you were +well sorry you may come back up here at + + align:start position:0% +well sorry you may come back up here at + + + align:start position:0% +well sorry you may come back up here at +work on your USB stick and then you keep + + align:start position:0% +work on your USB stick and then you keep + + + align:start position:0% +work on your USB stick and then you keep +spending money and then you drop your + + align:start position:0% +spending money and then you drop your + + + align:start position:0% +spending money and then you drop your +laptop in the pool and then you restore + + align:start position:0% +laptop in the pool and then you restore + + + align:start position:0% +laptop in the pool and then you restore +from your USB stick to here and then you + + align:start position:0% +from your USB stick to here and then you + + + align:start position:0% +from your USB stick to here and then you +try to broadcast this but you've already + + align:start position:0% +try to broadcast this but you've already + + + align:start position:0% +try to broadcast this but you've already +revealed your private keys and so Bob's + + align:start position:0% +revealed your private keys and so Bob's + + + align:start position:0% +revealed your private keys and so Bob's +just like what like that's red like you + + align:start position:0% +just like what like that's red like you + + + align:start position:0% +just like what like that's red like you +you revealed it and then he takes all + + align:start position:0% +you revealed it and then he takes all + + + align:start position:0% +you revealed it and then he takes all +the money so yeah don't make backups + + align:start position:0% +the money so yeah don't make backups + + + align:start position:0% +the money so yeah don't make backups +it's like the the reason I worry about + + align:start position:0% +it's like the the reason I worry about + + + align:start position:0% +it's like the the reason I worry about +it is it's very counterintuitive there's + + align:start position:0% +it is it's very counterintuitive there's + + + align:start position:0% +it is it's very counterintuitive there's +nothing in the software that does this + + align:start position:0% +nothing in the software that does this + + + align:start position:0% +nothing in the software that does this +right the software I can write like you + + align:start position:0% +right the software I can write like you + + + align:start position:0% +right the software I can write like you +know don't make backups always only keep + + align:start position:0% +know don't make backups always only keep + + + align:start position:0% +know don't make backups always only keep +this but you just copy the files and it + + align:start position:0% +this but you just copy the files and it + + + align:start position:0% +this but you just copy the files and it +seems like the kind of thing people + + align:start position:0% +seems like the kind of thing people + + + align:start position:0% +seems like the kind of thing people +might do and you know put warnings and + + align:start position:0% +might do and you know put warnings and + + + align:start position:0% +might do and you know put warnings and +the readme is and stuff so that's kind + + align:start position:0% +the readme is and stuff so that's kind + + + align:start position:0% +the readme is and stuff so that's kind +of a big risk so there's a lot of like + + align:start position:0% +of a big risk so there's a lot of like + + + align:start position:0% +of a big risk so there's a lot of like +how do we make this safe how do and like + + align:start position:0% +how do we make this safe how do and like + + + align:start position:0% +how do we make this safe how do and like +a lot of people criticize it like this + + align:start position:0% +a lot of people criticize it like this + + + align:start position:0% +a lot of people criticize it like this +is too complicated there's like enormous + + align:start position:0% +is too complicated there's like enormous + + + align:start position:0% +is too complicated there's like enormous +communities on the internet that hate + + align:start position:0% +communities on the internet that hate + + + align:start position:0% +communities on the internet that hate +this and hate me and mmm go to our BTCC + + align:start position:0% +this and hate me and mmm go to our BTCC + + + align:start position:0% +this and hate me and mmm go to our BTCC +don't like the lightning Network I don't + + align:start position:0% +don't like the lightning Network I don't + + + align:start position:0% +don't like the lightning Network I don't +mean the other kind it's like well you + + align:start position:0% +mean the other kind it's like well you + + + align:start position:0% +mean the other kind it's like well you +don't like it you don't to use it right + + align:start position:0% +don't like it you don't to use it right + + + align:start position:0% +don't like it you don't to use it right +I'm just writing the software for free + + align:start position:0% +I'm just writing the software for free + + + align:start position:0% +I'm just writing the software for free +for you guys but anyway but yeah and and + + align:start position:0% +for you guys but anyway but yeah and and + + + align:start position:0% +for you guys but anyway but yeah and and +you know there's legitimate like this is + + align:start position:0% +you know there's legitimate like this is + + + align:start position:0% +you know there's legitimate like this is +kind of complicated this might not it's + + align:start position:0% +kind of complicated this might not it's + + + align:start position:0% +kind of complicated this might not it's +not gonna work for everything there's + + align:start position:0% +not gonna work for everything there's + + + align:start position:0% +not gonna work for everything there's +all sorts of you know things that that + + align:start position:0% +all sorts of you know things that that + + + align:start position:0% +all sorts of you know things that that +limit limits to this too \ No newline at end of file diff --git a/Ii6UtH6h2jY.txt b/Ii6UtH6h2jY.txt new file mode 100644 index 0000000000000000000000000000000000000000..f889f4f401e7d4cae1c0e31f407b470c7737a9e7 --- /dev/null +++ b/Ii6UtH6h2jY.txt @@ -0,0 +1,11378 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit MIT opencourseware + + align:start position:0% +of MIT courses visit MIT opencourseware + + + align:start position:0% +of MIT courses visit MIT opencourseware +at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu okay um I was at uh Atlanta + + align:start position:0% +ocw.mit.edu okay um I was at uh Atlanta + + + align:start position:0% +ocw.mit.edu okay um I was at uh Atlanta +yesterday and uh attending a conference + + align:start position:0% +yesterday and uh attending a conference + + + align:start position:0% +yesterday and uh attending a conference +at the expert uh from the disc drive + + align:start position:0% +at the expert uh from the disc drive + + + align:start position:0% +at the expert uh from the disc drive +industry I know I know her well and uh + + align:start position:0% +industry I know I know her well and uh + + + align:start position:0% +industry I know I know her well and uh +you remember I was just saying that the + + align:start position:0% +you remember I was just saying that the + + + align:start position:0% +you remember I was just saying that the +disc hat and separation is below 10 n do + + align:start position:0% +disc hat and separation is below 10 n do + + + align:start position:0% +disc hat and separation is below 10 n do +you know how much what's the separation + + align:start position:0% +you know how much what's the separation + + + align:start position:0% +you know how much what's the separation +now two that's just say about 1.5 + + align:start position:0% +now two that's just say about 1.5 + + + align:start position:0% +now two that's just say about 1.5 +nmet that's the that's that's what + + align:start position:0% +nmet that's the that's that's what + + + align:start position:0% +nmet that's the that's that's what +everybody has in the computer it's + + align:start position:0% +everybody has in the computer it's + + + align:start position:0% +everybody has in the computer it's +amazing uh + + align:start position:0% +amazing uh + + + align:start position:0% +amazing uh +technology we just go for solid state + + align:start position:0% +technology we just go for solid state + + + align:start position:0% +technology we just go for solid state +huh we just go for solid + + align:start position:0% +huh we just go for solid + + + align:start position:0% +huh we just go for solid +well where you how much can push right + + align:start position:0% +well where you how much can push right + + + align:start position:0% +well where you how much can push right +but uh um the uh this is a this was + + align:start position:0% +but uh um the uh this is a this was + + + align:start position:0% +but uh um the uh this is a this was +actually a labmate of mine and uh uh she + + align:start position:0% +actually a labmate of mine and uh uh she + + + align:start position:0% +actually a labmate of mine and uh uh she +uh worked on N scale heat transfer and + + align:start position:0% +uh worked on N scale heat transfer and + + + align:start position:0% +uh worked on N scale heat transfer and +say that's a perfect place because what + + align:start position:0% +say that's a perfect place because what + + + align:start position:0% +say that's a perfect place because what +what they're doing is uh uh the magnatic + + align:start position:0% +what they're doing is uh uh the magnatic + + + align:start position:0% +what they're doing is uh uh the magnatic +when you make it a very small domain you + + align:start position:0% +when you make it a very small domain you + + + align:start position:0% +when you make it a very small domain you +actually cannot use a normal magnetic + + align:start position:0% +actually cannot use a normal magnetic + + + align:start position:0% +actually cannot use a normal magnetic +field to flip the uh magnetic domain + + align:start position:0% +field to flip the uh magnetic domain + + + align:start position:0% +field to flip the uh magnetic domain +because uh otherwise the at room + + align:start position:0% +because uh otherwise the at room + + + align:start position:0% +because uh otherwise the at room +temperature is just spontaneous flips + + align:start position:0% +temperature is just spontaneous flips + + + align:start position:0% +temperature is just spontaneous flips +back so they have to use very hard + + align:start position:0% +back so they have to use very hard + + + align:start position:0% +back so they have to use very hard +magnet magnet and uh in that case they + + align:start position:0% +magnet magnet and uh in that case they + + + align:start position:0% +magnet magnet and uh in that case they +have to heat up the domain so they have + + align:start position:0% +have to heat up the domain so they have + + + align:start position:0% +have to heat up the domain so they have +to heat up a nano domain first and then + + align:start position:0% +to heat up a nano domain first and then + + + align:start position:0% +to heat up a nano domain first and then +uh apply magnetic field to + + align:start position:0% +uh apply magnetic field to + + + align:start position:0% +uh apply magnetic field to +right um so I thought uh I'll share this + + align:start position:0% +right um so I thought uh I'll share this + + + align:start position:0% +right um so I thought uh I'll share this +story with you talk a little bit more + + align:start position:0% +story with you talk a little bit more + + + align:start position:0% +story with you talk a little bit more +about that technology later on as we + + align:start position:0% +about that technology later on as we + + + align:start position:0% +about that technology later on as we +learn so coming back to to um last + + align:start position:0% +learn so coming back to to um last + + + align:start position:0% +learn so coming back to to um last +lecture uh what we talked uh is the + + align:start position:0% +lecture uh what we talked uh is the + + + align:start position:0% +lecture uh what we talked uh is the +reciprocal space um the continuation and + + align:start position:0% +reciprocal space um the continuation and + + + align:start position:0% +reciprocal space um the continuation and +prove the bra condition and that's the + + align:start position:0% +prove the bra condition and that's the + + + align:start position:0% +prove the bra condition and that's the +uh uh say when you do a transmission + + align:start position:0% +uh uh say when you do a transmission + + + align:start position:0% +uh uh say when you do a transmission +electron microscope or you do a x-ray + + align:start position:0% +electron microscope or you do a x-ray + + + align:start position:0% +electron microscope or you do a x-ray +bra condition is the one when you look + + align:start position:0% +bra condition is the one when you look + + + align:start position:0% +bra condition is the one when you look +at defraction + + align:start position:0% +at defraction + + + align:start position:0% +at defraction +patterns and uh then we moved down to + + align:start position:0% +patterns and uh then we moved down to + + + align:start position:0% +patterns and uh then we moved down to +discuss the energy uh of the atomic + + align:start position:0% +discuss the energy uh of the atomic + + + align:start position:0% +discuss the energy uh of the atomic +vibration in + + align:start position:0% +vibration in + + + align:start position:0% +vibration in +crystals and uh uh um so we introduced + + align:start position:0% +crystals and uh uh um so we introduced + + + align:start position:0% +crystals and uh uh um so we introduced +the Fons right that's just the uh say we + + align:start position:0% +the Fons right that's just the uh say we + + + align:start position:0% +the Fons right that's just the uh say we +solve the Newton Second Law so it's a + + align:start position:0% +solve the Newton Second Law so it's a + + + align:start position:0% +solve the Newton Second Law so it's a +first is a Continuum approach it's a + + align:start position:0% +first is a Continuum approach it's a + + + align:start position:0% +first is a Continuum approach it's a +classical approach but the treating the + + align:start position:0% +classical approach but the treating the + + + align:start position:0% +classical approach but the treating the +atoms as disr and we got the dispersion + + align:start position:0% +atoms as disr and we got the dispersion + + + align:start position:0% +atoms as disr and we got the dispersion +between the vibrational + + align:start position:0% +between the vibrational + + + align:start position:0% +between the vibrational +frequency and the W vector and the V + + align:start position:0% +frequency and the W vector and the V + + + align:start position:0% +frequency and the W vector and the V +Vector is similarly as in the case of + + align:start position:0% +Vector is similarly as in the case of + + + align:start position:0% +Vector is similarly as in the case of +electron are discretized I have if I + + align:start position:0% +electron are discretized I have if I + + + align:start position:0% +electron are discretized I have if I +have n atoms in the chain and I have 2 + + align:start position:0% +have n atoms in the chain and I have 2 + + + align:start position:0% +have n atoms in the chain and I have 2 +pi uh Over N this is the separation is 2 + + align:start position:0% +pi uh Over N this is the separation is 2 + + + align:start position:0% +pi uh Over N this is the separation is 2 +pi over the length of the crystal n * a + + align:start position:0% +pi over the length of the crystal n * a + + + align:start position:0% +pi over the length of the crystal n * a +is the lens of the crystal right and uh + + align:start position:0% +is the lens of the crystal right and uh + + + align:start position:0% +is the lens of the crystal right and uh +uh we have acoustic branch and if I have + + align:start position:0% +uh we have acoustic branch and if I have + + + align:start position:0% +uh we have acoustic branch and if I have +more than one atom at the lest Point uh + + align:start position:0% +more than one atom at the lest Point uh + + + align:start position:0% +more than one atom at the lest Point uh +I have also after branch and acoustic + + align:start position:0% +I have also after branch and acoustic + + + align:start position:0% +I have also after branch and acoustic +branch has longitudinal and transverse + + align:start position:0% +branch has longitudinal and transverse + + + align:start position:0% +branch has longitudinal and transverse +typical longitudinal uh has a higher uh + + align:start position:0% +typical longitudinal uh has a higher uh + + + align:start position:0% +typical longitudinal uh has a higher uh +frequency and transverse lower + + align:start position:0% +frequency and transverse lower + + + align:start position:0% +frequency and transverse lower +frequency and in the case of op fullon + + align:start position:0% +frequency and in the case of op fullon + + + align:start position:0% +frequency and in the case of op fullon +this sometimes can cross over so it's + + align:start position:0% +this sometimes can cross over so it's + + + align:start position:0% +this sometimes can cross over so it's +hard to say which one has higher and + + align:start position:0% +hard to say which one has higher and + + + align:start position:0% +hard to say which one has higher and +lower but if I think if you deal with a + + align:start position:0% +lower but if I think if you deal with a + + + align:start position:0% +lower but if I think if you deal with a +polar Crystal like sodium chloride and + + align:start position:0% +polar Crystal like sodium chloride and + + + align:start position:0% +polar Crystal like sodium chloride and +uh you have always the transverse Fon + + align:start position:0% +uh you have always the transverse Fon + + + align:start position:0% +uh you have always the transverse Fon +lower and longitudal Fon op F on higher + + align:start position:0% +lower and longitudal Fon op F on higher + + + align:start position:0% +lower and longitudal Fon op F on higher +frequency so uh uh what's important + + align:start position:0% +frequency so uh uh what's important + + + align:start position:0% +frequency so uh uh what's important +later on is we simplify models and one + + align:start position:0% +later on is we simplify models and one + + + align:start position:0% +later on is we simplify models and one +way to simplify uh is the de buy so we + + align:start position:0% +way to simplify uh is the de buy so we + + + align:start position:0% +way to simplify uh is the de buy so we +trade this here uh although at the zoom + + align:start position:0% +trade this here uh although at the zoom + + + align:start position:0% +trade this here uh although at the zoom +boundary we see you can see we careful + + align:start position:0% +boundary we see you can see we careful + + + align:start position:0% +boundary we see you can see we careful +in drawing this almost like a + + align:start position:0% +in drawing this almost like a + + + align:start position:0% +in drawing this almost like a +perpendicular but say uh one + + align:start position:0% +perpendicular but say uh one + + + align:start position:0% +perpendicular but say uh one +approximation we use is approximate this + + align:start position:0% +approximation we use is approximate this + + + align:start position:0% +approximation we use is approximate this +by a street nine that's the buy model + + align:start position:0% +by a street nine that's the buy model + + + align:start position:0% +by a street nine that's the buy model +and uh the other uh is what original + + align:start position:0% +and uh the other uh is what original + + + align:start position:0% +and uh the other uh is what original +Einstein proposed just a constant + + align:start position:0% +Einstein proposed just a constant + + + align:start position:0% +Einstein proposed just a constant +frequency that's a Einstein model and + + align:start position:0% +frequency that's a Einstein model and + + + align:start position:0% +frequency that's a Einstein model and +you can see that Einstein model is + + align:start position:0% +you can see that Einstein model is + + + align:start position:0% +you can see that Einstein model is +closer for the optic fance or the buy + + align:start position:0% +closer for the optic fance or the buy + + + align:start position:0% +closer for the optic fance or the buy +model is closer for the uh um say um + + align:start position:0% +model is closer for the uh um say um + + + align:start position:0% +model is closer for the uh um say um +acoustic + + align:start position:0% +acoustic + + + align:start position:0% +acoustic +fance uh so that's uh uh where we were + + align:start position:0% +fance uh so that's uh uh where we were + + + align:start position:0% +fance uh so that's uh uh where we were +and uh with that uh if you recall what + + align:start position:0% +and uh with that uh if you recall what + + + align:start position:0% +and uh with that uh if you recall what +we have talked so far very fast right we + + align:start position:0% +we have talked so far very fast right we + + + align:start position:0% +we have talked so far very fast right we +talked about energy levels first in + + align:start position:0% +talked about energy levels first in + + + align:start position:0% +talked about energy levels first in +isolated atoms and + + align:start position:0% +isolated atoms and + + + align:start position:0% +isolated atoms and +molecules and that's vibrational + + align:start position:0% +molecules and that's vibrational + + + align:start position:0% +molecules and that's vibrational +translational and electronic rotational + + align:start position:0% +translational and electronic rotational + + + align:start position:0% +translational and electronic rotational +and then we extend to crystals and uh we + + align:start position:0% +and then we extend to crystals and uh we + + + align:start position:0% +and then we extend to crystals and uh we +view we say the the treatment the best + + align:start position:0% +view we say the the treatment the best + + + align:start position:0% +view we say the the treatment the best +treatment we've done is one dimension + + align:start position:0% +treatment we've done is one dimension + + + align:start position:0% +treatment we've done is one dimension +and then we say okay what's the if you + + align:start position:0% +and then we say okay what's the if you + + + align:start position:0% +and then we say okay what's the if you +look at the three dimension each + + align:start position:0% +look at the three dimension each + + + align:start position:0% +look at the three dimension each +Direction has different periodicity and + + align:start position:0% +Direction has different periodicity and + + + align:start position:0% +Direction has different periodicity and +different potential so your curve may + + align:start position:0% +different potential so your curve may + + + align:start position:0% +different potential so your curve may +look different right and uh uh with that + + align:start position:0% +look different right and uh uh with that + + + align:start position:0% +look different right and uh uh with that +you uh I hope you get appreciation for + + align:start position:0% +you uh I hope you get appreciation for + + + align:start position:0% +you uh I hope you get appreciation for +the energy levels of electrons in solid + + align:start position:0% +the energy levels of electrons in solid + + + align:start position:0% +the energy levels of electrons in solid +with that you can understand why there's + + align:start position:0% +with that you can understand why there's + + + align:start position:0% +with that you can understand why there's +insulator why there's semiconductor + + align:start position:0% +insulator why there's semiconductor + + + align:start position:0% +insulator why there's semiconductor +where there Metals right and uh also uh + + align:start position:0% +where there Metals right and uh also uh + + + align:start position:0% +where there Metals right and uh also uh +you uh can now also have some + + align:start position:0% +you uh can now also have some + + + align:start position:0% +you uh can now also have some +appreciation for the last + + align:start position:0% +appreciation for the last + + + align:start position:0% +appreciation for the last +vibration the Fons which is essentially + + align:start position:0% +vibration the Fons which is essentially + + + align:start position:0% +vibration the Fons which is essentially +here we do a classical treatment but + + align:start position:0% +here we do a classical treatment but + + + align:start position:0% +here we do a classical treatment but +what Fon is a quantized form of this + + align:start position:0% +what Fon is a quantized form of this + + + align:start position:0% +what Fon is a quantized form of this +frequency at each frequency for that + + align:start position:0% +frequency at each frequency for that + + + align:start position:0% +frequency at each frequency for that +mode you cannot have any energy you can + + align:start position:0% +mode you cannot have any energy you can + + + align:start position:0% +mode you cannot have any energy you can +only have discrete lber alha Fong the + + align:start position:0% +only have discrete lber alha Fong the + + + align:start position:0% +only have discrete lber alha Fong the +the energy is + + align:start position:0% +the energy is + + + align:start position:0% +the energy is +quantized right so uh those are the uh + + align:start position:0% +quantized right so uh those are the uh + + + align:start position:0% +quantized right so uh those are the uh +uh this give us some picture what are + + align:start position:0% +uh this give us some picture what are + + + align:start position:0% +uh this give us some picture what are +the quantum mechanical allowable energy + + align:start position:0% +the quantum mechanical allowable energy + + + align:start position:0% +the quantum mechanical allowable energy +in + + align:start position:0% +in + + + align:start position:0% +in +matters and what where we're going to + + align:start position:0% +matters and what where we're going to + + + align:start position:0% +matters and what where we're going to +move is to uh add the temperature this + + align:start position:0% +move is to uh add the temperature this + + + align:start position:0% +move is to uh add the temperature this +is a Quant mechanic allowable now if I + + align:start position:0% +is a Quant mechanic allowable now if I + + + align:start position:0% +is a Quant mechanic allowable now if I +have a object at certain temperature + + align:start position:0% +have a object at certain temperature + + + align:start position:0% +have a object at certain temperature +what's the uh um uh statistically + + align:start position:0% +what's the uh um uh statistically + + + align:start position:0% +what's the uh um uh statistically +average right and what what really + + align:start position:0% +average right and what what really + + + align:start position:0% +average right and what what really +what's the energy this object has so + + align:start position:0% +what's the energy this object has so + + + align:start position:0% +what's the energy this object has so +that's where we're moving and uh uh but + + align:start position:0% +that's where we're moving and uh uh but + + + align:start position:0% +that's where we're moving and uh uh but +before that uh I want to discuss a + + align:start position:0% +before that uh I want to discuss a + + + align:start position:0% +before that uh I want to discuss a +little more of the + + align:start position:0% +little more of the + + + align:start position:0% +little more of the +counting right and if you recall I said + + align:start position:0% +counting right and if you recall I said + + + align:start position:0% +counting right and if you recall I said +uh the I emphasized degeneracy a Quantum + + align:start position:0% +uh the I emphasized degeneracy a Quantum + + + align:start position:0% +uh the I emphasized degeneracy a Quantum +state right uh Quantum + + align:start position:0% +state right uh Quantum + + + align:start position:0% +state right uh Quantum +state right is defined by in the case of + + align:start position:0% +state right is defined by in the case of + + + align:start position:0% +state right is defined by in the case of +waves uh is if I have wave function + + align:start position:0% +waves uh is if I have wave function + + + align:start position:0% +waves uh is if I have wave function +right uh in let's say I have my wave + + align:start position:0% +right uh in let's say I have my wave + + + align:start position:0% +right uh in let's say I have my wave +function and KX KY + + align:start position:0% +function and KX KY + + + align:start position:0% +function and KX KY +KZ right each of this uh uh KX KY KZ so + + align:start position:0% +KZ right each of this uh uh KX KY KZ so + + + align:start position:0% +KZ right each of this uh uh KX KY KZ so +here in for example in One Direction I + + align:start position:0% +here in for example in One Direction I + + + align:start position:0% +here in for example in One Direction I +have discrete number of K values right + + align:start position:0% +have discrete number of K values right + + + align:start position:0% +have discrete number of K values right +each combination of K value gives me one + + align:start position:0% +each combination of K value gives me one + + + align:start position:0% +each combination of K value gives me one +specific wave a wave function right one + + align:start position:0% +specific wave a wave function right one + + + align:start position:0% +specific wave a wave function right one +wave + + align:start position:0% +wave + + + align:start position:0% +wave +function is if I don't consider spin + + align:start position:0% +function is if I don't consider spin + + + align:start position:0% +function is if I don't consider spin +right electron I have to say one wave + + align:start position:0% +right electron I have to say one wave + + + align:start position:0% +right electron I have to say one wave +function because of the wave function + + align:start position:0% +function because of the wave function + + + align:start position:0% +function because of the wave function +itself doesn't include spin so uh one + + align:start position:0% +itself doesn't include spin so uh one + + + align:start position:0% +itself doesn't include spin so uh one +that's one Quantum + + align:start position:0% +that's one Quantum + + + align:start position:0% +that's one Quantum +State okay and uh uh in the case of uh + + align:start position:0% +State okay and uh uh in the case of uh + + + align:start position:0% +State okay and uh uh in the case of uh +discrete atoms uh we say quantum numbers + + align:start position:0% +discrete atoms uh we say quantum numbers + + + align:start position:0% +discrete atoms uh we say quantum numbers +right if you recall uh when we do + + align:start position:0% +right if you recall uh when we do + + + align:start position:0% +right if you recall uh when we do +electronic States we have uh n m uh NL + + align:start position:0% +electronic States we have uh n m uh NL + + + align:start position:0% +electronic States we have uh n m uh NL +M right that's the quantum number and we + + align:start position:0% +M right that's the quantum number and we + + + align:start position:0% +M right that's the quantum number and we +emphasize the Quant because different + + align:start position:0% +emphasize the Quant because different + + + align:start position:0% +emphasize the Quant because different +combination of nlm could actually have + + align:start position:0% +combination of nlm could actually have + + + align:start position:0% +combination of nlm could actually have +the same + + align:start position:0% +the same + + + align:start position:0% +the same +energy that's where we say this is how + + align:start position:0% +energy that's where we say this is how + + + align:start position:0% +energy that's where we say this is how +you start understand the periodical + + align:start position:0% +you start understand the periodical + + + align:start position:0% +you start understand the periodical +table right the + + align:start position:0% +table right the + + + align:start position:0% +table right the +degeneracy now if you look at + + align:start position:0% +degeneracy now if you look at + + + align:start position:0% +degeneracy now if you look at +solid I'm only drawing in One Direction + + align:start position:0% +solid I'm only drawing in One Direction + + + align:start position:0% +solid I'm only drawing in One Direction +but we know that the real crystal solid + + align:start position:0% +but we know that the real crystal solid + + + align:start position:0% +but we know that the real crystal solid +is three + + align:start position:0% +is three + + + align:start position:0% +is three +directions and uh now if I count certain + + align:start position:0% +directions and uh now if I count certain + + + align:start position:0% +directions and uh now if I count certain +frequency or certain energy if you think + + align:start position:0% +frequency or certain energy if you think + + + align:start position:0% +frequency or certain energy if you think +about either frequency of energy because + + align:start position:0% +about either frequency of energy because + + + align:start position:0% +about either frequency of energy because +H Omega GES + + align:start position:0% +H Omega GES + + + align:start position:0% +H Omega GES +energy right and uh even in the same + + align:start position:0% +energy right and uh even in the same + + + align:start position:0% +energy right and uh even in the same +direction you can say here I have three + + align:start position:0% +direction you can say here I have three + + + align:start position:0% +direction you can say here I have three +states three wave + + align:start position:0% +states three wave + + + align:start position:0% +states three wave +vectors right that can have same Quantum + + align:start position:0% +vectors right that can have same Quantum + + + align:start position:0% +vectors right that can have same Quantum +state right same + + align:start position:0% +state right same + + + align:start position:0% +state right same +energy three wheel vectors three Quantum + + align:start position:0% +energy three wheel vectors three Quantum + + + align:start position:0% +energy three wheel vectors three Quantum +State can have same energy but if I look + + align:start position:0% +State can have same energy but if I look + + + align:start position:0% +State can have same energy but if I look +at the other directions right many many + + align:start position:0% +at the other directions right many many + + + align:start position:0% +at the other directions right many many +other + + align:start position:0% +other + + + align:start position:0% +other +directions I would have many other + + align:start position:0% +directions I would have many other + + + align:start position:0% +directions I would have many other +possible states that could have the same + + align:start position:0% +possible states that could have the same + + + align:start position:0% +possible states that could have the same +energy so that's the degeneracy and + + align:start position:0% +energy so that's the degeneracy and + + + align:start position:0% +energy so that's the degeneracy and +that's where I have to learn how to do + + align:start position:0% +that's where I have to learn how to do + + + align:start position:0% +that's where I have to learn how to do +that + + align:start position:0% +that + + + align:start position:0% +that +counting okay so this is uh a major + + align:start position:0% +counting okay so this is uh a major + + + align:start position:0% +counting okay so this is uh a major +emphasis today it's the idea of + + align:start position:0% +emphasis today it's the idea of + + + align:start position:0% +emphasis today it's the idea of +counting today + + align:start position:0% +counting today + + + align:start position:0% +counting today +we really doing the density of states + + align:start position:0% + + + + align:start position:0% + +and then when I say States I see this is + + align:start position:0% +and then when I say States I see this is + + + align:start position:0% +and then when I say States I see this is +like density of quantum + + align:start position:0% +like density of quantum + + + align:start position:0% +like density of quantum +States okay and uh uh I also hope at the + + align:start position:0% +States okay and uh uh I also hope at the + + + align:start position:0% +States okay and uh uh I also hope at the +end I have uh with that I'll get into uh + + align:start position:0% +end I have uh with that I'll get into uh + + + align:start position:0% +end I have uh with that I'll get into uh +Quantum statistics + + align:start position:0% + + + + align:start position:0% + +so this is uh my plan + + align:start position:0% +so this is uh my plan + + + align:start position:0% +so this is uh my plan +today and uh let's + + align:start position:0% +today and uh let's + + + align:start position:0% +today and uh let's +start uh we have looked at a very + + align:start position:0% +start uh we have looked at a very + + + align:start position:0% +start uh we have looked at a very +complic say band structure for electrons + + align:start position:0% +complic say band structure for electrons + + + align:start position:0% +complic say band structure for electrons +for Fons this is like going to uh the + + align:start position:0% +for Fons this is like going to uh the + + + align:start position:0% +for Fons this is like going to uh the +Google and you look at all those + + align:start position:0% +Google and you look at all those + + + align:start position:0% +Google and you look at all those +different images right but say uh for + + align:start position:0% +different images right but say uh for + + + align:start position:0% +different images right but say uh for +the analytical purpose we're going to + + align:start position:0% +the analytical purpose we're going to + + + align:start position:0% +the analytical purpose we're going to +look at the simplest model like the buy + + align:start position:0% +look at the simplest model like the buy + + + align:start position:0% +look at the simplest model like the buy +model and for electrons uh we also say + + align:start position:0% +model and for electrons uh we also say + + + align:start position:0% +model and for electrons uh we also say +if it's the either minimum of the + + align:start position:0% +if it's the either minimum of the + + + align:start position:0% +if it's the either minimum of the +conduction band or the maximum of the + + align:start position:0% +conduction band or the maximum of the + + + align:start position:0% +conduction band or the maximum of the +bance band we expand that near that + + align:start position:0% +bance band we expand that near that + + + align:start position:0% +bance band we expand that near that +minimum maximum right so we have + + align:start position:0% +minimum maximum right so we have + + + align:start position:0% +minimum maximum right so we have +parabolic bands so uh uh + + align:start position:0% +parabolic bands so uh uh + + + align:start position:0% +parabolic bands so uh uh +let's we need uh uh this + + align:start position:0% + + + + align:start position:0% + +uh so if you uh recall for electrons of + + align:start position:0% + + + + align:start position:0% + +approximation and uh + + align:start position:0% +approximation and uh + + + align:start position:0% +approximation and uh +uh in the simplest picture this is my K + + align:start position:0% +uh in the simplest picture this is my K + + + align:start position:0% +uh in the simplest picture this is my K +and K you can think is KX KY k z and + + align:start position:0% +and K you can think is KX KY k z and + + + align:start position:0% +and K you can think is KX KY k z and +here is my conduction B and I write this + + align:start position:0% +here is my conduction B and I write this + + + align:start position:0% +here is my conduction B and I write this +at the minimum k equal Z minimum here + + align:start position:0% +at the minimum k equal Z minimum here + + + align:start position:0% +at the minimum k equal Z minimum here +and you can put that at a different + + align:start position:0% +and you can put that at a different + + + align:start position:0% +and you can put that at a different +point okay and uh uh this curvature + + align:start position:0% +point okay and uh uh this curvature + + + align:start position:0% +point okay and uh uh this curvature +gives me effective Mass so uh if I say + + align:start position:0% +gives me effective Mass so uh if I say + + + align:start position:0% +gives me effective Mass so uh if I say +this is the energy and I expand this at + + align:start position:0% +this is the energy and I expand this at + + + align:start position:0% +this is the energy and I expand this at +the minimum then the uh uh energy W + + align:start position:0% +the minimum then the uh uh energy W + + + align:start position:0% +the minimum then the uh uh energy W +Vector + + align:start position:0% +Vector + + + align:start position:0% +Vector +relation right and here is my e say the + + align:start position:0% +relation right and here is my e say the + + + align:start position:0% +relation right and here is my e say the +bottom here so energy Vector relation is + + align:start position:0% +bottom here so energy Vector relation is + + + align:start position:0% +bottom here so energy Vector relation is +e say plus h bar k + + align:start position:0% +e say plus h bar k + + + align:start position:0% +e say plus h bar k +squide by 2 m Star right so H bar k we + + align:start position:0% +squide by 2 m Star right so H bar k we + + + align:start position:0% +squide by 2 m Star right so H bar k we +see under this effective Mass concept + + align:start position:0% +see under this effective Mass concept + + + align:start position:0% +see under this effective Mass concept +it's really just like the 12 MV squ + + align:start position:0% +it's really just like the 12 MV squ + + + align:start position:0% +it's really just like the 12 MV squ +because h k gives me momentum p p IDE by + + align:start position:0% +because h k gives me momentum p p IDE by + + + align:start position:0% +because h k gives me momentum p p IDE by +uh Mass gives me uh say uh say gives me + + align:start position:0% +uh Mass gives me uh say uh say gives me + + + align:start position:0% +uh Mass gives me uh say uh say gives me +velocity right so uh that's the + + align:start position:0% +velocity right so uh that's the + + + align:start position:0% +velocity right so uh that's the +parabolic band + + align:start position:0% +parabolic band + + + align:start position:0% +parabolic band +approximation and what we need to keep + + align:start position:0% +approximation and what we need to keep + + + align:start position:0% +approximation and what we need to keep +in mind the + + align:start position:0% +in mind the + + + align:start position:0% +in mind the +K is Vector in 3D space + + align:start position:0% +K is Vector in 3D space + + + align:start position:0% +K is Vector in 3D space +right so KX we said if in the X + + align:start position:0% +right so KX we said if in the X + + + align:start position:0% +right so KX we said if in the X +Direction uh is 2 pi n * + + align:start position:0% +Direction uh is 2 pi n * + + + align:start position:0% +Direction uh is 2 pi n * +LX + + align:start position:0% +LX + + + align:start position:0% +LX +right and uh uh again the uh at the end + + align:start position:0% +right and uh uh again the uh at the end + + + align:start position:0% +right and uh uh again the uh at the end +if I do all this parabolic band + + align:start position:0% +if I do all this parabolic band + + + align:start position:0% +if I do all this parabolic band +approximation my zoom boundary is here + + align:start position:0% +approximation my zoom boundary is here + + + align:start position:0% +approximation my zoom boundary is here +this is a pi over + + align:start position:0% +this is a pi over + + + align:start position:0% +this is a pi over +ax right NX is how many atoms times this + + align:start position:0% +ax right NX is how many atoms times this + + + align:start position:0% +ax right NX is how many atoms times this +period ax + + align:start position:0% +period ax + + + align:start position:0% +period ax +okay so let's say LX equals n uh uh in + + align:start position:0% +okay so let's say LX equals n uh uh in + + + align:start position:0% +okay so let's say LX equals n uh uh in +the X Direction and periodicity in the X + + align:start position:0% +the X Direction and periodicity in the X + + + align:start position:0% +the X Direction and periodicity in the X +direction right that's our simple 1D + + align:start position:0% +direction right that's our simple 1D + + + align:start position:0% +direction right that's our simple 1D +model just to make a comment by passing + + align:start position:0% +model just to make a comment by passing + + + align:start position:0% +model just to make a comment by passing +now some of + + align:start position:0% +now some of + + + align:start position:0% +now some of +you uh probably do work in + + align:start position:0% +you uh probably do work in + + + align:start position:0% +you uh probably do work in +graphine um uh see what's special with + + align:start position:0% +graphine um uh see what's special with + + + align:start position:0% +graphine um uh see what's special with +graphine is that uh at uh + + align:start position:0% +graphine is that uh at uh + + + align:start position:0% +graphine is that uh at uh +uh the bottom + + align:start position:0% +uh the bottom + + + align:start position:0% +uh the bottom +here the uh band here is uh not qu see a + + align:start position:0% +here the uh band here is uh not qu see a + + + align:start position:0% +here the uh band here is uh not qu see a +parabola it's actually a straight + + align:start position:0% +parabola it's actually a straight + + + align:start position:0% +parabola it's actually a straight +line okay so uh a + + align:start position:0% + + + + align:start position:0% + +graphing graphing the dispersion this is + + align:start position:0% +graphing graphing the dispersion this is + + + align:start position:0% +graphing graphing the dispersion this is +the energy this is V vector and in small + + align:start position:0% +the energy this is V vector and in small + + + align:start position:0% +the energy this is V vector and in small +region near the fir level right it's a + + align:start position:0% +region near the fir level right it's a + + + align:start position:0% +region near the fir level right it's a +zero Gap so the bank Gap happen to be + + align:start position:0% +zero Gap so the bank Gap happen to be + + + align:start position:0% +zero Gap so the bank Gap happen to be +zero and so at the fir level the + + align:start position:0% +zero and so at the fir level the + + + align:start position:0% +zero and so at the fir level the +dispersion is a + + align:start position:0% +dispersion is a + + + align:start position:0% +dispersion is a +linear and this linear dispersion make + + align:start position:0% +linear and this linear dispersion make + + + align:start position:0% +linear and this linear dispersion make +the very similar to the bi model for Fon + + align:start position:0% +the very similar to the bi model for Fon + + + align:start position:0% +the very similar to the bi model for Fon +and also Photon right photon is if you + + align:start position:0% +and also Photon right photon is if you + + + align:start position:0% +and also Photon right photon is if you +think about the model for photon is + + align:start position:0% +think about the model for photon is + + + align:start position:0% +think about the model for photon is +Omega equals + + align:start position:0% +Omega equals + + + align:start position:0% +Omega equals +CK right that's the speed of light and + + align:start position:0% +CK right that's the speed of light and + + + align:start position:0% +CK right that's the speed of light and +for foron Omega equals V K that + + align:start position:0% +for foron Omega equals V K that + + + align:start position:0% +for foron Omega equals V K that +V is the by velocity sometimes we + + align:start position:0% +V is the by velocity sometimes we + + + align:start position:0% +V is the by velocity sometimes we +associate with the sound + + align:start position:0% +associate with the sound + + + align:start position:0% +associate with the sound +velocity right so that makes the + + align:start position:0% +velocity right so that makes the + + + align:start position:0% +velocity right so that makes the +electron similar to + + align:start position:0% +electron similar to + + + align:start position:0% +electron similar to +Photon and uh similar to Fons so that's + + align:start position:0% +Photon and uh similar to Fons so that's + + + align:start position:0% +Photon and uh similar to Fons so that's +what special uh with the uh + + align:start position:0% +what special uh with the uh + + + align:start position:0% +what special uh with the uh +graphing uh so uh this is KX and of + + align:start position:0% +graphing uh so uh this is KX and of + + + align:start position:0% +graphing uh so uh this is KX and of +course I have similar K by KZ and K + + align:start position:0% +course I have similar K by KZ and K + + + align:start position:0% +course I have similar K by KZ and K +square is a com + + align:start position:0% +square is a com + + + align:start position:0% +square is a com +of KX + + align:start position:0% +of KX + + + align:start position:0% +of KX +s+ k y² + k z + + align:start position:0% +s+ k y² + k z + + + align:start position:0% +s+ k y² + k z +s okay so this means right my constant + + align:start position:0% +s okay so this means right my constant + + + align:start position:0% +s okay so this means right my constant +energy surface if I give K is a + + align:start position:0% +energy surface if I give K is a + + + align:start position:0% +energy surface if I give K is a +constant uh energy is a constant right + + align:start position:0% +constant uh energy is a constant right + + + align:start position:0% +constant uh energy is a constant right +KX KY KZ gives me a sphere so is a + + align:start position:0% +KX KY KZ gives me a sphere so is a + + + align:start position:0% +KX KY KZ gives me a sphere so is a +spherical uh uh say a constant energy + + align:start position:0% +spherical uh uh say a constant energy + + + align:start position:0% +spherical uh uh say a constant energy +surface uh sometimes you draw real + + align:start position:0% +surface uh sometimes you draw real + + + align:start position:0% +surface uh sometimes you draw real +constant energy surface in solid it look + + align:start position:0% +constant energy surface in solid it look + + + align:start position:0% +constant energy surface in solid it look +very complicated sometimes it look like + + align:start position:0% +very complicated sometimes it look like + + + align:start position:0% +very complicated sometimes it look like +a el SW or even other + + align:start position:0% +a el SW or even other + + + align:start position:0% +a el SW or even other +shapes okay but I'm doing the simplest + + align:start position:0% +shapes okay but I'm doing the simplest + + + align:start position:0% +shapes okay but I'm doing the simplest +model and uh so what uh you can say is + + align:start position:0% +model and uh so what uh you can say is + + + align:start position:0% +model and uh so what uh you can say is +there are many combination of KX KY KZ + + align:start position:0% +there are many combination of KX KY KZ + + + align:start position:0% +there are many combination of KX KY KZ +that could give me the same energy e and + + align:start position:0% +that could give me the same energy e and + + + align:start position:0% +that could give me the same energy e and +each combination is one Quantum State + + align:start position:0% +each combination is one Quantum State + + + align:start position:0% +each combination is one Quantum State +including a factor of two if I think + + align:start position:0% +including a factor of two if I think + + + align:start position:0% +including a factor of two if I think +about spin + + align:start position:0% +about spin + + + align:start position:0% +about spin +right so uh this is a uh the uh + + align:start position:0% +right so uh this is a uh the uh + + + align:start position:0% +right so uh this is a uh the uh +dispersion the energy with Vector + + align:start position:0% +dispersion the energy with Vector + + + align:start position:0% +dispersion the energy with Vector +relation is dispersion and uh for + + align:start position:0% +relation is dispersion and uh for + + + align:start position:0% +relation is dispersion and uh for +electrons and for + + align:start position:0% + + + + align:start position:0% + +Fons we already said Omega equals V K + + align:start position:0% +Fons we already said Omega equals V K + + + align:start position:0% +Fons we already said Omega equals V K +that's the by approximation and K now uh + + align:start position:0% +that's the by approximation and K now uh + + + align:start position:0% +that's the by approximation and K now uh +uh that's the k for we for the electron + + align:start position:0% +uh that's the k for we for the electron + + + align:start position:0% +uh that's the k for we for the electron +uh for the Fon W Vector but again uh + + align:start position:0% +uh for the Fon W Vector but again uh + + + align:start position:0% +uh for the Fon W Vector but again uh +based on discussion we have those are + + align:start position:0% +based on discussion we have those are + + + align:start position:0% +based on discussion we have those are +allowable + + align:start position:0% +allowable + + + align:start position:0% +allowable +values right so uh and for + + align:start position:0% + + + + align:start position:0% + +Photon Omega equals c k like I just + + align:start position:0% +Photon Omega equals c k like I just + + + align:start position:0% +Photon Omega equals c k like I just +written + + align:start position:0% +written + + + align:start position:0% +written +down but say this k for + + align:start position:0% +down but say this k for + + + align:start position:0% +down but say this k for +Photon I I don't have upper + + align:start position:0% +Photon I I don't have upper + + + align:start position:0% +Photon I I don't have upper +limit uh it's a uh I haven't discussed + + align:start position:0% +limit uh it's a uh I haven't discussed + + + align:start position:0% +limit uh it's a uh I haven't discussed +uh so in in free space this K could be + + align:start position:0% +uh so in in free space this K could be + + + align:start position:0% +uh so in in free space this K could be +really + + align:start position:0% +really + + + align:start position:0% +really +large okay so uh those are the uh + + align:start position:0% +large okay so uh those are the uh + + + align:start position:0% +large okay so uh those are the uh +dispersion between frequency with vector + + align:start position:0% +dispersion between frequency with vector + + + align:start position:0% +dispersion between frequency with vector +or energy with Vector all those we call + + align:start position:0% +or energy with Vector all those we call + + + align:start position:0% +or energy with Vector all those we call +dispersion relations right now based on + + align:start position:0% +dispersion relations right now based on + + + align:start position:0% +dispersion relations right now based on +this I'm going to count how many states + + align:start position:0% +this I'm going to count how many states + + + align:start position:0% +this I'm going to count how many states +so it turns out uh for example I want to + + align:start position:0% +so it turns out uh for example I want to + + + align:start position:0% +so it turns out uh for example I want to +count uh a I have any electrons right + + align:start position:0% +count uh a I have any electrons right + + + align:start position:0% +count uh a I have any electrons right +where is the fir + + align:start position:0% +where is the fir + + + align:start position:0% +where is the fir +level if you recall when I did uh the + + align:start position:0% +level if you recall when I did uh the + + + align:start position:0% +level if you recall when I did uh the +simple onedimensional uh hydrogen Atomic + + align:start position:0% +simple onedimensional uh hydrogen Atomic + + + align:start position:0% +simple onedimensional uh hydrogen Atomic +chain right and we say this is + + align:start position:0% +chain right and we say this is + + + align:start position:0% +chain right and we say this is +the we say this is a + + align:start position:0% + + + + align:start position:0% + +dispersion + + align:start position:0% +dispersion + + + align:start position:0% +dispersion +okay and uh I have between here minus Pi + + align:start position:0% +okay and uh I have between here minus Pi + + + align:start position:0% +okay and uh I have between here minus Pi +/ a to plus pi a symmetric and I have K + + align:start position:0% +/ a to plus pi a symmetric and I have K + + + align:start position:0% +/ a to plus pi a symmetric and I have K +points I say uh if it's 1D I go to the + + align:start position:0% +points I say uh if it's 1D I go to the + + + align:start position:0% +points I say uh if it's 1D I go to the +lowest States and because I have n + + align:start position:0% +lowest States and because I have n + + + align:start position:0% +lowest States and because I have n +States between pi a to minus Pi minus pi + + align:start position:0% +States between pi a to minus Pi minus pi + + + align:start position:0% +States between pi a to minus Pi minus pi +to plus pi I have n electrons and each + + align:start position:0% +to plus pi I have n electrons and each + + + align:start position:0% +to plus pi I have n electrons and each +of this wave function have spin up spin + + align:start position:0% +of this wave function have spin up spin + + + align:start position:0% +of this wave function have spin up spin +down so I fa to the + + align:start position:0% +down so I fa to the + + + align:start position:0% +down so I fa to the +middle right that's a 1D case now if I + + align:start position:0% +middle right that's a 1D case now if I + + + align:start position:0% +middle right that's a 1D case now if I +ask the same question if it's a 3D + + align:start position:0% +ask the same question if it's a 3D + + + align:start position:0% +ask the same question if it's a 3D +where does it go where is the + + align:start position:0% +where does it go where is the + + + align:start position:0% +where does it go where is the +fining + + align:start position:0% +fining + + + align:start position:0% +fining +right and uh uh in in that case uh + + align:start position:0% +right and uh uh in in that case uh + + + align:start position:0% +right and uh uh in in that case uh +because there are many KX KY KZ + + align:start position:0% +because there are many KX KY KZ + + + align:start position:0% +because there are many KX KY KZ +combination K give me the same energy + + align:start position:0% +combination K give me the same energy + + + align:start position:0% +combination K give me the same energy +level so I have to uh do this + + align:start position:0% +level so I have to uh do this + + + align:start position:0% +level so I have to uh do this +summation so this is total number of + + align:start position:0% +summation so this is total number of + + + align:start position:0% +summation so this is total number of +electrons let's say total number of + + align:start position:0% +electrons let's say total number of + + + align:start position:0% +electrons let's say total number of +atoms right if I say hydrogen each + + align:start position:0% +atoms right if I say hydrogen each + + + align:start position:0% +atoms right if I say hydrogen each +hydrogen give me one electron + + align:start position:0% +hydrogen give me one electron + + + align:start position:0% +hydrogen give me one electron +right and then I have to sum up what I + + align:start position:0% +right and then I have to sum up what I + + + align:start position:0% +right and then I have to sum up what I +know is let's say uh + + align:start position:0% +know is let's say uh + + + align:start position:0% +know is let's say uh +uh the at the zero + + align:start position:0% +uh the at the zero + + + align:start position:0% +uh the at the zero +temperature the lowest energy is field + + align:start position:0% +temperature the lowest energy is field + + + align:start position:0% +temperature the lowest energy is field +first right so I uh I have to think this + + align:start position:0% +first right so I uh I have to think this + + + align:start position:0% +first right so I uh I have to think this +now rather than 1 D I have to think + + align:start position:0% +now rather than 1 D I have to think + + + align:start position:0% +now rather than 1 D I have to think +about + + align:start position:0% +about + + + align:start position:0% +about +3D three dimensional coordinate right + + align:start position:0% +3D three dimensional coordinate right + + + align:start position:0% +3D three dimensional coordinate right +and uh uh + + align:start position:0% +and uh uh + + + align:start position:0% +and uh uh +you will feel to the lowest and to the + + align:start position:0% +you will feel to the lowest and to the + + + align:start position:0% +you will feel to the lowest and to the +uppermost this is recall this is my + + align:start position:0% +uppermost this is recall this is my + + + align:start position:0% +uppermost this is recall this is my +EF right that's where my f level + + align:start position:0% +EF right that's where my f level + + + align:start position:0% +EF right that's where my f level +is and + + align:start position:0% +is and + + + align:start position:0% +is and +correspondingly this is my K if I say + + align:start position:0% +correspondingly this is my K if I say + + + align:start position:0% +correspondingly this is my K if I say +this is my + + align:start position:0% + + + + align:start position:0% + +KF okay and my model is K XYZ all + + align:start position:0% +KF okay and my model is K XYZ all + + + align:start position:0% +KF okay and my model is K XYZ all +direction are the same if you look at + + align:start position:0% +direction are the same if you look at + + + align:start position:0% +direction are the same if you look at +what I written down right so uh KF so + + align:start position:0% +what I written down right so uh KF so + + + align:start position:0% +what I written down right so uh KF so +this is a coming uh constant energy + + align:start position:0% +this is a coming uh constant energy + + + align:start position:0% +this is a coming uh constant energy +sphere and the constant wave Vector uh + + align:start position:0% +sphere and the constant wave Vector uh + + + align:start position:0% +sphere and the constant wave Vector uh +also at that uh location so when they + + align:start position:0% +also at that uh location so when they + + + align:start position:0% +also at that uh location so when they +uh so each of this combination KX KY KZ + + align:start position:0% +uh so each of this combination KX KY KZ + + + align:start position:0% +uh so each of this combination KX KY KZ +gives me one Quantum State as long as + + align:start position:0% +gives me one Quantum State as long as + + + align:start position:0% +gives me one Quantum State as long as +this Quantum state lies below + + align:start position:0% +this Quantum state lies below + + + align:start position:0% +this Quantum state lies below +EF it has one + + align:start position:0% +EF it has one + + + align:start position:0% +EF it has one +electron so I add that total should give + + align:start position:0% +electron so I add that total should give + + + align:start position:0% +electron so I add that total should give +me total number of n total L of + + align:start position:0% +me total number of n total L of + + + align:start position:0% +me total number of n total L of +electrons okay and recall this is a huge + + align:start position:0% +electrons okay and recall this is a huge + + + align:start position:0% +electrons okay and recall this is a huge +L right if I say one more of God Conant + + align:start position:0% +L right if I say one more of God Conant + + + align:start position:0% +L right if I say one more of God Conant +10 to + + align:start position:0% +10 to + + + align:start position:0% +10 to +23rd okay it's it's going to be very + + align:start position:0% +23rd okay it's it's going to be very + + + align:start position:0% +23rd okay it's it's going to be very +large lber summation so what I have here + + align:start position:0% +large lber summation so what I have here + + + align:start position:0% +large lber summation so what I have here +is going to I say KX so any of this + + align:start position:0% +is going to I say KX so any of this + + + align:start position:0% +is going to I say KX so any of this +loable values below KF all that KX value + + align:start position:0% +loable values below KF all that KX value + + + align:start position:0% +loable values below KF all that KX value +right each I have many points + + align:start position:0% +right each I have many points + + + align:start position:0% +right each I have many points +there I have + + align:start position:0% + + + + align:start position:0% + +KY + + align:start position:0% +KY + + + align:start position:0% +KY +same I have k + + align:start position:0% + + + + align:start position:0% + +z + + align:start position:0% +z + + + align:start position:0% +z +right as as long as this KX squ + k y + + align:start position:0% +right as as long as this KX squ + k y + + + align:start position:0% +right as as long as this KX squ + k y +squ plus KZ + + align:start position:0% +squ plus KZ + + + align:start position:0% +squ plus KZ +squ uh uh is wi in this is KF squ + + align:start position:0% + + + + align:start position:0% + +right so as long as within this + + align:start position:0% + + + + align:start position:0% + +range that combination all those + + align:start position:0% +range that combination all those + + + align:start position:0% +range that combination all those +combination give me a Quantum State + + align:start position:0% +combination give me a Quantum State + + + align:start position:0% +combination give me a Quantum State +that's + + align:start position:0% +that's + + + align:start position:0% +that's +fied right so I have each KX KY discrete + + align:start position:0% +fied right so I have each KX KY discrete + + + align:start position:0% +fied right so I have each KX KY discrete +Point KX KY + + align:start position:0% +Point KX KY + + + align:start position:0% +Point KX KY +KZ gives me one Quantum State except + + align:start position:0% +KZ gives me one Quantum State except + + + align:start position:0% +KZ gives me one Quantum State except +that doesn't count spin so I have factor + + align:start position:0% +that doesn't count spin so I have factor + + + align:start position:0% +that doesn't count spin so I have factor +of + + align:start position:0% +of + + + align:start position:0% +of +two right so each of this Quantum state + + align:start position:0% +two right so each of this Quantum state + + + align:start position:0% +two right so each of this Quantum state +has one electron + + align:start position:0% +has one electron + + + align:start position:0% +has one electron +right 2 plus KX KY KZ combination has + + align:start position:0% +right 2 plus KX KY KZ combination has + + + align:start position:0% +right 2 plus KX KY KZ combination has +one + + align:start position:0% +one + + + align:start position:0% +one +electron right each of this uh so what + + align:start position:0% +electron right each of this uh so what + + + align:start position:0% +electron right each of this uh so what +I'm really summing up that + + align:start position:0% +I'm really summing up that + + + align:start position:0% +I'm really summing up that +one one + + align:start position:0% +one one + + + align:start position:0% +one one +electron do you get me I'm doing + + align:start position:0% +electron do you get me I'm doing + + + align:start position:0% +electron do you get me I'm doing +counting it's basic + + align:start position:0% +counting it's basic + + + align:start position:0% +counting it's basic +counting okay now if later on I'm not + + align:start position:0% +counting okay now if later on I'm not + + + align:start position:0% +counting okay now if later on I'm not +going to + + align:start position:0% +going to + + + align:start position:0% +going to +do one I'm going to do half field at a + + align:start position:0% +do one I'm going to do half field at a + + + align:start position:0% +do one I'm going to do half field at a +certain temperature for example some + + align:start position:0% +certain temperature for example some + + + align:start position:0% +certain temperature for example some +states could be empty right so I make it + + align:start position:0% +states could be empty right so I make it + + + align:start position:0% +states could be empty right so I make it +that say rather than one I may be a + + align:start position:0% +that say rather than one I may be a + + + align:start position:0% +that say rather than one I may be a +probability uh very soon at the end of + + align:start position:0% +probability uh very soon at the end of + + + align:start position:0% +probability uh very soon at the end of +lecture I hope I get there so this will + + align:start position:0% +lecture I hope I get there so this will + + + align:start position:0% +lecture I hope I get there so this will +be a function of energy and chemical + + align:start position:0% +be a function of energy and chemical + + + align:start position:0% +be a function of energy and chemical +potential and + + align:start position:0% +potential and + + + align:start position:0% +potential and +temperature right here I'm doing my + + align:start position:0% +temperature right here I'm doing my + + + align:start position:0% +temperature right here I'm doing my +simplest case at zero temperature any + + align:start position:0% +simplest case at zero temperature any + + + align:start position:0% +simplest case at zero temperature any +Quantom State below the fir level are + + align:start position:0% +Quantom State below the fir level are + + + align:start position:0% +Quantom State below the fir level are +fielded and I have my requirement I have + + align:start position:0% +fielded and I have my requirement I have + + + align:start position:0% +fielded and I have my requirement I have +total n + + align:start position:0% +total n + + + align:start position:0% +total n +electrons and I want to find out where + + align:start position:0% +electrons and I want to find out where + + + align:start position:0% +electrons and I want to find out where +is my KF where is my + + align:start position:0% +is my KF where is my + + + align:start position:0% +is my KF where is my +EF + + align:start position:0% +EF + + + align:start position:0% +EF +okay so now you go to do a + + align:start position:0% +okay so now you go to do a + + + align:start position:0% +okay so now you go to do a +summation how you do the + + align:start position:0% +summation how you do the + + + align:start position:0% +summation how you do the +summation + + align:start position:0% +summation + + + align:start position:0% +summation +right and uh doing + + align:start position:0% +right and uh doing + + + align:start position:0% +right and uh doing +summation when it has many unless it's a + + align:start position:0% +summation when it has many unless it's a + + + align:start position:0% +summation when it has many unless it's a +simple series it's not + + align:start position:0% +simple series it's not + + + align:start position:0% +simple series it's not +easy right so + + align:start position:0% +easy right so + + + align:start position:0% +easy right so +uh the way to do it is convert that + + align:start position:0% +uh the way to do it is convert that + + + align:start position:0% +uh the way to do it is convert that +summation into + + align:start position:0% +summation into + + + align:start position:0% +summation into +integration that's what we going to do + + align:start position:0% +integration that's what we going to do + + + align:start position:0% +integration that's what we going to do +next and uh the condition for converting + + align:start position:0% +next and uh the condition for converting + + + align:start position:0% +next and uh the condition for converting +a summation into integration right if I + + align:start position:0% +a summation into integration right if I + + + align:start position:0% +a summation into integration right if I +have a function here + + align:start position:0% +have a function here + + + align:start position:0% +have a function here +right and remember this is a k each set + + align:start position:0% +right and remember this is a k each set + + + align:start position:0% +right and remember this is a k each set +of point + + align:start position:0% +of point + + + align:start position:0% +of point +is one value I'm summing up those values + + align:start position:0% +is one value I'm summing up those values + + + align:start position:0% +is one value I'm summing up those values +when I do that summation right + + align:start position:0% + + + + align:start position:0% + +and now if this function does not vary + + align:start position:0% +and now if this function does not vary + + + align:start position:0% +and now if this function does not vary +rapidly between the + + align:start position:0% +rapidly between the + + + align:start position:0% +rapidly between the +points it's like you do trapezoidal + + align:start position:0% +points it's like you do trapezoidal + + + align:start position:0% +points it's like you do trapezoidal +rule you can actually do convert this + + align:start position:0% +rule you can actually do convert this + + + align:start position:0% +rule you can actually do convert this +some some back into + + align:start position:0% +some some back into + + + align:start position:0% +some some back into +integration so how we do it okay let's + + align:start position:0% +integration so how we do it okay let's + + + align:start position:0% +integration so how we do it okay let's +say KX right if I have a Delta + + align:start position:0% + + + + align:start position:0% + +KX right right or dkx when I do + + align:start position:0% +KX right right or dkx when I do + + + align:start position:0% +KX right right or dkx when I do +integration I do dkx right so how many + + align:start position:0% +integration I do dkx right so how many + + + align:start position:0% +integration I do dkx right so how many +points there are in + + align:start position:0% + + + + align:start position:0% + +dkx now I look at the spacing between + + align:start position:0% +dkx now I look at the spacing between + + + align:start position:0% +dkx now I look at the spacing between +two adjacent Point KX 2 pi + + align:start position:0% +two adjacent Point KX 2 pi + + + align:start position:0% +two adjacent Point KX 2 pi +n LX so what's the spacing between two + + align:start position:0% +n LX so what's the spacing between two + + + align:start position:0% +n LX so what's the spacing between two +adjacent + + align:start position:0% +adjacent + + + align:start position:0% +adjacent +Point 2 pi x RX right so I do dkx / by 2 + + align:start position:0% +Point 2 pi x RX right so I do dkx / by 2 + + + align:start position:0% +Point 2 pi x RX right so I do dkx / by 2 +pi LX that's how many points over + + align:start position:0% +pi LX that's how many points over + + + align:start position:0% +pi LX that's how many points over +dkx okay so now I'm converting this one + + align:start position:0% +dkx okay so now I'm converting this one + + + align:start position:0% +dkx okay so now I'm converting this one +and rather than sum over D say KX I do + + align:start position:0% +and rather than sum over D say KX I do + + + align:start position:0% +and rather than sum over D say KX I do +integration + + align:start position:0% +integration + + + align:start position:0% +integration +over this is my integration + + align:start position:0% + + + + align:start position:0% + +over uh KX so what's my limit if this is + + align:start position:0% +over uh KX so what's my limit if this is + + + align:start position:0% +over uh KX so what's my limit if this is +a kxf and minus kxf right so I have Min + + align:start position:0% +a kxf and minus kxf right so I have Min + + + align:start position:0% +a kxf and minus kxf right so I have Min +- K + + align:start position:0% +- K + + + align:start position:0% +- K +FX plus K FX remember + + align:start position:0% +FX plus K FX remember + + + align:start position:0% +FX plus K FX remember +I mean uh uh symmetry right K negative + + align:start position:0% +I mean uh uh symmetry right K negative + + + align:start position:0% +I mean uh uh symmetry right K negative +positive K + + align:start position:0% +positive K + + + align:start position:0% +positive K +symmetry okay and I do the + + align:start position:0% +symmetry okay and I do the + + + align:start position:0% +symmetry okay and I do the +same D + + align:start position:0% +same D + + + align:start position:0% +same D +KY and 2 pi l y + + align:start position:0% +KY and 2 pi l y + + + align:start position:0% +KY and 2 pi l y +KF y k + + align:start position:0% +KF y k + + + align:start position:0% +KF y k +FY + + align:start position:0% +FY + + + align:start position:0% +FY +and + + align:start position:0% +and + + + align:start position:0% +and +kfz K + + align:start position:0% +kfz K + + + align:start position:0% +kfz K +FZ + + align:start position:0% +FZ + + + align:start position:0% +FZ +dkz 2 pi l + + align:start position:0% +dkz 2 pi l + + + align:start position:0% +dkz 2 pi l +z and that integration is over one but + + align:start position:0% +z and that integration is over one but + + + align:start position:0% +z and that integration is over one but +you probably don't like one one is just + + align:start position:0% +you probably don't like one one is just + + + align:start position:0% +you probably don't like one one is just +look two th so let me just put any + + align:start position:0% +look two th so let me just put any + + + align:start position:0% +look two th so let me just put any +function as said before right say later + + align:start position:0% +function as said before right say later + + + align:start position:0% +function as said before right say later +on when I say the formula will I come + + align:start position:0% +on when I say the formula will I come + + + align:start position:0% +on when I say the formula will I come +back to fals 1 so the f as a function of + + align:start position:0% +back to fals 1 so the f as a function of + + + align:start position:0% +back to fals 1 so the f as a function of +e Mt right and turns out this F could be + + align:start position:0% +e Mt right and turns out this F could be + + + align:start position:0% +e Mt right and turns out this F could be +any function sometimes this F F could be + + align:start position:0% +any function sometimes this F F could be + + + align:start position:0% +any function sometimes this F F could be +a function of e sometimes this fun this + + align:start position:0% +a function of e sometimes this fun this + + + align:start position:0% +a function of e sometimes this fun this +could be a function of + + align:start position:0% +could be a function of + + + align:start position:0% +could be a function of +K + + align:start position:0% +K + + + align:start position:0% +K +okay and most of time when we do a deal + + align:start position:0% +okay and most of time when we do a deal + + + align:start position:0% +okay and most of time when we do a deal +with d States it's a function of + + align:start position:0% +with d States it's a function of + + + align:start position:0% +with d States it's a function of +e so you want convert the function e or + + align:start position:0% +e so you want convert the function e or + + + align:start position:0% +e so you want convert the function e or +a function of frequency but when you do + + align:start position:0% +a function of frequency but when you do + + + align:start position:0% +a function of frequency but when you do +transport I just want to warn you when + + align:start position:0% +transport I just want to warn you when + + + align:start position:0% +transport I just want to warn you when +you do + + align:start position:0% +you do + + + align:start position:0% +you do +transport this function is open function + + align:start position:0% +transport this function is open function + + + align:start position:0% +transport this function is open function +of K so the way I do that the summation + + align:start position:0% +of K so the way I do that the summation + + + align:start position:0% +of K so the way I do that the summation +sometimes in transport is actually not + + align:start position:0% +sometimes in transport is actually not + + + align:start position:0% +sometimes in transport is actually not +very useful but it's such a so common + + align:start position:0% +very useful but it's such a so common + + + align:start position:0% +very useful but it's such a so common +concept that's used every every time you + + align:start position:0% +concept that's used every every time you + + + align:start position:0% +concept that's used every every time you +go to read or discuss people say what's + + align:start position:0% +go to read or discuss people say what's + + + align:start position:0% +go to read or discuss people say what's +your D what's your D St + + align:start position:0% +your D what's your D St + + + align:start position:0% +your D what's your D St +States okay so this is I'm converting + + align:start position:0% +States okay so this is I'm converting + + + align:start position:0% +States okay so this is I'm converting +that of course I have factor of two I + + align:start position:0% +that of course I have factor of two I + + + align:start position:0% +that of course I have factor of two I +have my + + align:start position:0% +have my + + + align:start position:0% +have my +n this is the same I'm writing that + + align:start position:0% +n this is the same I'm writing that + + + align:start position:0% +n this is the same I'm writing that +summation into + + align:start position:0% +summation into + + + align:start position:0% +summation into +integration and uh so now with this you + + align:start position:0% +integration and uh so now with this you + + + align:start position:0% +integration and uh so now with this you +can say LX l y l z gives me + + align:start position:0% +can say LX l y l z gives me + + + align:start position:0% +can say LX l y l z gives me +volume right and 2 pi cubic so what I + + align:start position:0% +volume right and 2 pi cubic so what I + + + align:start position:0% +volume right and 2 pi cubic so what I +have is a two Volume 2 pi + + align:start position:0% +have is a two Volume 2 pi + + + align:start position:0% +have is a two Volume 2 pi +cubic and then say I have me let me + + align:start position:0% +cubic and then say I have me let me + + + align:start position:0% +cubic and then say I have me let me +skipe the uh uh the the integration + + align:start position:0% +skipe the uh uh the the integration + + + align:start position:0% +skipe the uh uh the the integration +limit and what I have here is + + align:start position:0% +limit and what I have here is + + + align:start position:0% +limit and what I have here is +dkx + + align:start position:0% +dkx + + + align:start position:0% +dkx +dky DK Z + + align:start position:0% + + + + align:start position:0% + +right triple + + align:start position:0% +right triple + + + align:start position:0% +right triple +integral so by this + + align:start position:0% +integral so by this + + + align:start position:0% +integral so by this +transformation assuming this function f + + align:start position:0% +transformation assuming this function f + + + align:start position:0% +transformation assuming this function f +does not change very rapidly between + + align:start position:0% +does not change very rapidly between + + + align:start position:0% +does not change very rapidly between +adjacent + + align:start position:0% +adjacent + + + align:start position:0% +adjacent +point I have converted this summation + + align:start position:0% +point I have converted this summation + + + align:start position:0% +point I have converted this summation +into + + align:start position:0% + + + + align:start position:0% + +integration and uh uh now I have further + + align:start position:0% +integration and uh uh now I have further + + + align:start position:0% +integration and uh uh now I have further +freedom because uh you see here if I + + align:start position:0% +freedom because uh you see here if I + + + align:start position:0% +freedom because uh you see here if I +give you this function f in terms of e e + + align:start position:0% +give you this function f in terms of e e + + + align:start position:0% +give you this function f in terms of e e +is a function of K so you have the + + align:start position:0% +is a function of K so you have the + + + align:start position:0% +is a function of K so you have the +freedom how you do integration whether + + align:start position:0% +freedom how you do integration whether + + + align:start position:0% +freedom how you do integration whether +you integrate in terms of e or integrate + + align:start position:0% +you integrate in terms of e or integrate + + + align:start position:0% +you integrate in terms of e or integrate +in term of K you have to convert relate + + align:start position:0% +in term of K you have to convert relate + + + align:start position:0% +in term of K you have to convert relate +them right change into same variable so + + align:start position:0% +them right change into same variable so + + + align:start position:0% +them right change into same variable so +you can do your + + align:start position:0% +you can do your + + + align:start position:0% +you can do your +integration and all uh so what I can do + + align:start position:0% +integration and all uh so what I can do + + + align:start position:0% +integration and all uh so what I can do +is here is what I'm doing is in a ction + + align:start position:0% +is here is what I'm doing is in a ction + + + align:start position:0% +is here is what I'm doing is in a ction +coordinate dkx d KY dkz is a ction + + align:start position:0% +coordinate dkx d KY dkz is a ction + + + align:start position:0% +coordinate dkx d KY dkz is a ction +coordinate + + align:start position:0% +coordinate + + + align:start position:0% +coordinate +right and if this is a spherical + + align:start position:0% +right and if this is a spherical + + + align:start position:0% +right and if this is a spherical +symmetric so far if it's a function of e + + align:start position:0% +symmetric so far if it's a function of e + + + align:start position:0% +symmetric so far if it's a function of e +you can say if it's function of e is + + align:start position:0% +you can say if it's function of e is + + + align:start position:0% +you can say if it's function of e is +spherical + + align:start position:0% +spherical + + + align:start position:0% +spherical +symmetric + + align:start position:0% +symmetric + + + align:start position:0% +symmetric +right I don't have so if the function of + + align:start position:0% +right I don't have so if the function of + + + align:start position:0% +right I don't have so if the function of +e uh uh for + + align:start position:0% + + + + align:start position:0% + +fora here Omega is K + + align:start position:0% +fora here Omega is K + + + align:start position:0% +fora here Omega is K +so it does not depend on so in that case + + align:start position:0% +so it does not depend on so in that case + + + align:start position:0% +so it does not depend on so in that case +it's much easier if I + + align:start position:0% +it's much easier if I + + + align:start position:0% +it's much easier if I +do convert KX KY KZ into just a + + align:start position:0% +do convert KX KY KZ into just a + + + align:start position:0% +do convert KX KY KZ into just a +k into a spherical coordinate right + + align:start position:0% +k into a spherical coordinate right + + + align:start position:0% +k into a spherical coordinate right +rather than doing triple integral I do + + align:start position:0% +rather than doing triple integral I do + + + align:start position:0% +rather than doing triple integral I do +just uh say DK uh if it's a uh doing + + align:start position:0% +just uh say DK uh if it's a uh doing + + + align:start position:0% +just uh say DK uh if it's a uh doing +spherical if it's this one is another + + align:start position:0% +spherical if it's this one is another + + + align:start position:0% +spherical if it's this one is another +function it's only function of absolute + + align:start position:0% +function it's only function of absolute + + + align:start position:0% +function it's only function of absolute +value of + + align:start position:0% +value of + + + align:start position:0% +value of +K it's I so this is a 4 Pi can you tell + + align:start position:0% +K it's I so this is a 4 Pi can you tell + + + align:start position:0% +K it's I so this is a 4 Pi can you tell +me huh K squ + + align:start position:0% +me huh K squ + + + align:start position:0% +me huh K squ +DK + + align:start position:0% + + + + align:start position:0% + +right try translating from a c into + + align:start position:0% +right try translating from a c into + + + align:start position:0% +right try translating from a c into +spheric so everything of here is a + + align:start position:0% +spheric so everything of here is a + + + align:start position:0% +spheric so everything of here is a +math but what's amazing is people this + + align:start position:0% +math but what's amazing is people this + + + align:start position:0% +math but what's amazing is people this +is such a convenient concept to talk + + align:start position:0% +is such a convenient concept to talk + + + align:start position:0% +is such a convenient concept to talk +about right so here is 4 Pi K squ DK and + + align:start position:0% +about right so here is 4 Pi K squ DK and + + + align:start position:0% +about right so here is 4 Pi K squ DK and +uh uh then I can group this + + align:start position:0% + + + + align:start position:0% + +together okay now I'm going to group + + align:start position:0% +together okay now I'm going to group + + + align:start position:0% +together okay now I'm going to group +this back into here H so that uh uh uh + + align:start position:0% +this back into here H so that uh uh uh + + + align:start position:0% +this back into here H so that uh uh uh +my uh I like to write n over way but + + align:start position:0% +my uh I like to write n over way but + + + align:start position:0% +my uh I like to write n over way but +many people say so this in that case my + + align:start position:0% +many people say so this in that case my + + + align:start position:0% +many people say so this in that case my +D of this per unit volume so here on our + + align:start position:0% +D of this per unit volume so here on our + + + align:start position:0% +D of this per unit volume so here on our +way then is + + align:start position:0% +way then is + + + align:start position:0% +way then is +uh the + + align:start position:0% +uh the + + + align:start position:0% +uh the +integration integration and the F here I + + align:start position:0% +integration integration and the F here I + + + align:start position:0% +integration integration and the F here I +combine whatever all inside uh + + align:start position:0% +combine whatever all inside uh + + + align:start position:0% +combine whatever all inside uh +into uh you can say I have Pi Square K + + align:start position:0% +into uh you can say I have Pi Square K + + + align:start position:0% +into uh you can say I have Pi Square K +Square + + align:start position:0% +Square + + + align:start position:0% +Square +DK + + align:start position:0% + + + + align:start position:0% + +right and uh so here K is zero to KF + + align:start position:0% + + + + align:start position:0% + +Z + + align:start position:0% +Z + + + align:start position:0% +Z +KF because I'm doing spherical + + align:start position:0% +KF because I'm doing spherical + + + align:start position:0% +KF because I'm doing spherical +coordinate my radius is zero my KF I + + align:start position:0% +coordinate my radius is zero my KF I + + + align:start position:0% +coordinate my radius is zero my KF I +don't do negative positive because + + align:start position:0% +don't do negative positive because + + + align:start position:0% +don't do negative positive because +that's a condition coordinate you see + + align:start position:0% +that's a condition coordinate you see + + + align:start position:0% +that's a condition coordinate you see +what I'm doing okay so this one now is + + align:start position:0% +what I'm doing okay so this one now is + + + align:start position:0% +what I'm doing okay so this one now is +my density of + + align:start position:0% +my density of + + + align:start position:0% +my density of +States this is a density of stat + + align:start position:0% + + + + align:start position:0% + +uh so it's a l of States per unit + + align:start position:0% +uh so it's a l of States per unit + + + align:start position:0% +uh so it's a l of States per unit +interval of + + align:start position:0% +interval of + + + align:start position:0% +interval of +K right how many states Quantum State I + + align:start position:0% +K right how many states Quantum State I + + + align:start position:0% +K right how many states Quantum State I +have per Delta + + align:start position:0% +have per Delta + + + align:start position:0% +have per Delta +K right because here I'm say in DK my + + align:start position:0% +K right because here I'm say in DK my + + + align:start position:0% +K right because here I'm say in DK my +integration is in DK so then this step + + align:start position:0% +integration is in DK so then this step + + + align:start position:0% +integration is in DK so then this step +States + + align:start position:0% +States + + + align:start position:0% +States +in if I write as in terms of K that + + align:start position:0% +in if I write as in terms of K that + + + align:start position:0% +in if I write as in terms of K that +means it's per Delta + + align:start position:0% +means it's per Delta + + + align:start position:0% +means it's per Delta +k okay okay but say uh if you go back + + align:start position:0% +k okay okay but say uh if you go back + + + align:start position:0% +k okay okay but say uh if you go back +to what uh I eluded here if my f is the + + align:start position:0% +to what uh I eluded here if my f is the + + + align:start position:0% +to what uh I eluded here if my f is the +function of e then you have to make your + + align:start position:0% +function of e then you have to make your + + + align:start position:0% +function of e then you have to make your +CH Choice whether you want to convert + + align:start position:0% +CH Choice whether you want to convert + + + align:start position:0% +CH Choice whether you want to convert +the e in this F F into K or you want to + + align:start position:0% +the e in this F F into K or you want to + + + align:start position:0% +the e in this F F into K or you want to +convert that DK into a function of + + align:start position:0% +convert that DK into a function of + + + align:start position:0% +convert that DK into a function of +e right it's just your choice there's no + + align:start position:0% +e right it's just your choice there's no + + + align:start position:0% +e right it's just your choice there's no +uh formula there it's whatever is a itic + + align:start position:0% +uh formula there it's whatever is a itic + + + align:start position:0% +uh formula there it's whatever is a itic +convenient for you so uh I could also + + align:start position:0% +convenient for you so uh I could also + + + align:start position:0% +convenient for you so uh I could also +convert if I want to do a convert into + + align:start position:0% +convert if I want to do a convert into + + + align:start position:0% +convert if I want to do a convert into +uh energy integration so I will do + + align:start position:0% +uh energy integration so I will do + + + align:start position:0% +uh energy integration so I will do +EF and F so in that case I'll write this + + align:start position:0% +EF and F so in that case I'll write this + + + align:start position:0% +EF and F so in that case I'll write this +uh into uh K Square Pi Pi Square + + align:start position:0% +uh into uh K Square Pi Pi Square + + + align:start position:0% +uh into uh K Square Pi Pi Square +DK + + align:start position:0% +DK + + + align:start position:0% +DK +D and D right at the the everything in + + align:start position:0% +D and D right at the the everything in + + + align:start position:0% +D and D right at the the everything in +this blob I'm going to convert right in + + align:start position:0% +this blob I'm going to convert right in + + + align:start position:0% +this blob I'm going to convert right in +terms of e so I have a relation between + + align:start position:0% +terms of e so I have a relation between + + + align:start position:0% +terms of e so I have a relation between +K + + align:start position:0% +K + + + align:start position:0% +K +right and E so I can convert this K into + + align:start position:0% +right and E so I can convert this K into + + + align:start position:0% +right and E so I can convert this K into +e so if I write this in in terms of e + + align:start position:0% +e so if I write this in in terms of e + + + align:start position:0% +e so if I write this in in terms of e +and i integrate over e this is my + + align:start position:0% +and i integrate over e this is my + + + align:start position:0% +and i integrate over e this is my +density of States per energy + + align:start position:0% +density of States per energy + + + align:start position:0% +density of States per energy +interval right here is my L of States + + align:start position:0% +interval right here is my L of States + + + align:start position:0% +interval right here is my L of States +per Delta k here is my dens stat per + + align:start position:0% +per Delta k here is my dens stat per + + + align:start position:0% +per Delta k here is my dens stat per +Delta e and say similarly you can write + + align:start position:0% +Delta e and say similarly you can write + + + align:start position:0% +Delta e and say similarly you can write +your per Delta Omega or per Delta NE or + + align:start position:0% +your per Delta Omega or per Delta NE or + + + align:start position:0% +your per Delta Omega or per Delta NE or +per Delta + + align:start position:0% + + + + align:start position:0% + +Lambda so with that I want to just to + + align:start position:0% +Lambda so with that I want to just to + + + align:start position:0% +Lambda so with that I want to just to +say you have the you feel that it's it's + + align:start position:0% +say you have the you feel that it's it's + + + align:start position:0% +say you have the you feel that it's it's +a mathematic concept and the case you + + align:start position:0% +a mathematic concept and the case you + + + align:start position:0% +a mathematic concept and the case you +can translate you can start from here + + align:start position:0% +can translate you can start from here + + + align:start position:0% +can translate you can start from here +you can write your summation and go + + align:start position:0% +you can write your summation and go + + + align:start position:0% +you can write your summation and go +through that I've done that probably 100 + + align:start position:0% +through that I've done that probably 100 + + + align:start position:0% +through that I've done that probably 100 +of times so now I can I remember when I + + align:start position:0% +of times so now I can I remember when I + + + align:start position:0% +of times so now I can I remember when I +learned I always go to book and what's + + align:start position:0% +learned I always go to book and what's + + + align:start position:0% +learned I always go to book and what's +the formula gave in the book but if you + + align:start position:0% +the formula gave in the book but if you + + + align:start position:0% +the formula gave in the book but if you +get comfortable with that summation is + + align:start position:0% +get comfortable with that summation is + + + align:start position:0% +get comfortable with that summation is +translating summation into integration + + align:start position:0% +translating summation into integration + + + align:start position:0% +translating summation into integration +and particularly when later on when we + + align:start position:0% +and particularly when later on when we + + + align:start position:0% +and particularly when later on when we +do like a bman equation transport this + + align:start position:0% +do like a bman equation transport this + + + align:start position:0% +do like a bman equation transport this +is going to a function of KX KY + + align:start position:0% +is going to a function of KX KY + + + align:start position:0% +is going to a function of KX KY +KZ so I do not actually do D when I + + align:start position:0% +KZ so I do not actually do D when I + + + align:start position:0% +KZ so I do not actually do D when I +convert dkx dky dkz I do see f i do + + align:start position:0% +convert dkx dky dkz I do see f i do + + + align:start position:0% +convert dkx dky dkz I do see f i do +spherical coordinate but I don't have + + align:start position:0% +spherical coordinate but I don't have + + + align:start position:0% +spherical coordinate but I don't have +the function itself do not have + + align:start position:0% +the function itself do not have + + + align:start position:0% +the function itself do not have +spherical symmetry so I will have to do + + align:start position:0% +spherical symmetry so I will have to do + + + align:start position:0% +spherical symmetry so I will have to do +in the general case this one right if I + + align:start position:0% +in the general case this one right if I + + + align:start position:0% +in the general case this one right if I +do sperical coordinate is sin Theta D + + align:start position:0% +do sperical coordinate is sin Theta D + + + align:start position:0% +do sperical coordinate is sin Theta D +Theta d f d uh K and K Square so this + + align:start position:0% +Theta d f d uh K and K Square so this + + + align:start position:0% +Theta d f d uh K and K Square so this +will be my spherical converting a unit + + align:start position:0% +will be my spherical converting a unit + + + align:start position:0% +will be my spherical converting a unit +volume in ction into a unit volume in + + align:start position:0% +volume in ction into a unit volume in + + + align:start position:0% +volume in ction into a unit volume in +spheric right but we're not doing the + + align:start position:0% +spheric right but we're not doing the + + + align:start position:0% +spheric right but we're not doing the +now when you do transport this is is so + + align:start position:0% +now when you do transport this is is so + + + align:start position:0% +now when you do transport this is is so +common + + align:start position:0% +common + + + align:start position:0% +common +okay okay so that's the uh uh the the + + align:start position:0% +okay okay so that's the uh uh the the + + + align:start position:0% +okay okay so that's the uh uh the the +concept of den States and let's best uh + + align:start position:0% +concept of den States and let's best uh + + + align:start position:0% +concept of den States and let's best uh +uh use this concept and do a few + + align:start position:0% +uh use this concept and do a few + + + align:start position:0% +uh use this concept and do a few +examples to + + align:start position:0% +examples to + + + align:start position:0% +examples to +get fer more + + align:start position:0% + + + + align:start position:0% + +comfortable so let's first + + align:start position:0% + + + + align:start position:0% + +uh look at that they continue our fir + + align:start position:0% + + + + align:start position:0% + +level right and uh uh I'm going + + align:start position:0% +level right and uh uh I'm going + + + align:start position:0% +level right and uh uh I'm going +to you can take in in this case it + + align:start position:0% +to you can take in in this case it + + + align:start position:0% +to you can take in in this case it +depends on whether you take where you + + align:start position:0% +depends on whether you take where you + + + align:start position:0% +depends on whether you take where you +take a reference e say right + + align:start position:0% +take a reference e say right + + + align:start position:0% +take a reference e say right +here + + align:start position:0% +here + + + align:start position:0% +here +uh uh if I write the way I'm writing 0 + + align:start position:0% +uh uh if I write the way I'm writing 0 + + + align:start position:0% +uh uh if I write the way I'm writing 0 +to + + align:start position:0% +to + + + align:start position:0% +to +EF integration 0 to EF means zero the + + align:start position:0% +EF integration 0 to EF means zero the + + + align:start position:0% +EF integration 0 to EF means zero the +Finish start equal + + align:start position:0% +Finish start equal + + + align:start position:0% +Finish start equal +Z so in that case I cannot use EC + + align:start position:0% +Z so in that case I cannot use EC + + + align:start position:0% +Z so in that case I cannot use EC +because between + + align:start position:0% +because between + + + align:start position:0% +because between +zero and EC there's no energy state + + align:start position:0% +zero and EC there's no energy state + + + align:start position:0% +zero and EC there's no energy state +electron cannot fail between zero EC + + align:start position:0% +electron cannot fail between zero EC + + + align:start position:0% +electron cannot fail between zero EC +right so you have to be careful when you + + align:start position:0% +right so you have to be careful when you + + + align:start position:0% +right so you have to be careful when you +write those + + align:start position:0% +write those + + + align:start position:0% +write those +formulas uh and use yourself + + align:start position:0% +formulas uh and use yourself + + + align:start position:0% +formulas uh and use yourself +consistently what's your reference where + + align:start position:0% +consistently what's your reference where + + + align:start position:0% +consistently what's your reference where +you're doing your + + align:start position:0% +you're doing your + + + align:start position:0% +you're doing your +integration just a + + align:start position:0% +integration just a + + + align:start position:0% +integration just a +reminder and uh if I do following what I + + align:start position:0% +reminder and uh if I do following what I + + + align:start position:0% +reminder and uh if I do following what I +have here I have per unit volume I give + + align:start position:0% +have here I have per unit volume I give + + + align:start position:0% +have here I have per unit volume I give +you this number of + + align:start position:0% +you this number of + + + align:start position:0% +you this number of +electrons and I want to find at Absolute + + align:start position:0% +electrons and I want to find at Absolute + + + align:start position:0% +electrons and I want to find at Absolute +Zero temperature where is the uppermost + + align:start position:0% +Zero temperature where is the uppermost + + + align:start position:0% +Zero temperature where is the uppermost +energy + + align:start position:0% +energy + + + align:start position:0% +energy +level right so my uh band then E equals + + align:start position:0% +level right so my uh band then E equals + + + align:start position:0% +level right so my uh band then E equals +h² k sare 2 + + align:start position:0% +h² k sare 2 + + + align:start position:0% +h² k sare 2 +m because my uh energy start the fining + + align:start position:0% +m because my uh energy start the fining + + + align:start position:0% +m because my uh energy start the fining +start this is my e this is my K I'm + + align:start position:0% +start this is my e this is my K I'm + + + align:start position:0% +start this is my e this is my K I'm +trying to find out where is + + align:start position:0% +trying to find out where is + + + align:start position:0% +trying to find out where is +EF right this is the + + align:start position:0% +EF right this is the + + + align:start position:0% +EF right this is the +formula and uh so in that case what I + + align:start position:0% +formula and uh so in that case what I + + + align:start position:0% +formula and uh so in that case what I +have is FAL 1 + + align:start position:0% + + + + align:start position:0% + +right uh that's below the formula will + + align:start position:0% +right uh that's below the formula will + + + align:start position:0% +right uh that's below the formula will +all the energy each state is uh uh spin + + align:start position:0% +all the energy each state is uh uh spin + + + align:start position:0% +all the energy each state is uh uh spin +up spin down so I have n equals n way + + align:start position:0% +up spin down so I have n equals n way + + + align:start position:0% +up spin down so I have n equals n way +equals z + + align:start position:0% +equals z + + + align:start position:0% +equals z +EF and uh uh one so the uh K Square so + + align:start position:0% +EF and uh uh one so the uh K Square so + + + align:start position:0% +EF and uh uh one so the uh K Square so +what's my K Square now I need to convert + + align:start position:0% +what's my K Square now I need to convert + + + align:start position:0% +what's my K Square now I need to convert +I want to convert into e + + align:start position:0% +I want to convert into e + + + align:start position:0% +I want to convert into e +okay this one is easy that's my if I do + + align:start position:0% +okay this one is easy that's my if I do + + + align:start position:0% +okay this one is easy that's my if I do +in terms of + + align:start position:0% +in terms of + + + align:start position:0% +in terms of +K but I want to do in terms of e and uh + + align:start position:0% +K but I want to do in terms of e and uh + + + align:start position:0% +K but I want to do in terms of e and uh +uh so what I have K Square uh is 2 m + + align:start position:0% +uh so what I have K Square uh is 2 m + + + align:start position:0% +uh so what I have K Square uh is 2 m +right so k equal 2 m star e over H bar + + align:start position:0% +right so k equal 2 m star e over H bar + + + align:start position:0% +right so k equal 2 m star e over H bar +Square 12 right based on the dispersion + + align:start position:0% +Square 12 right based on the dispersion + + + align:start position:0% +Square 12 right based on the dispersion +so I have two uh K square is 2 m uh star + + align:start position:0% +so I have two uh K square is 2 m uh star + + + align:start position:0% +so I have two uh K square is 2 m uh star +e h bar Square that's my K Square Pi + + align:start position:0% +e h bar Square that's my K Square Pi + + + align:start position:0% +e h bar Square that's my K Square Pi +Square so I will put a pi Square + + align:start position:0% +Square so I will put a pi Square + + + align:start position:0% +Square so I will put a pi Square +here and then I have my D + + align:start position:0% +here and then I have my D + + + align:start position:0% +here and then I have my D +KDE DK + + align:start position:0% +KDE DK + + + align:start position:0% +KDE DK +D this is my K this is my e so my dkd is + + align:start position:0% +D this is my K this is my e so my dkd is + + + align:start position:0% +D this is my K this is my e so my dkd is +12 uh 2 m star + + align:start position:0% +12 uh 2 m star + + + align:start position:0% +12 uh 2 m star +H bar square and uh uh DK D is this is a + + align:start position:0% +H bar square and uh uh DK D is this is a + + + align:start position:0% +H bar square and uh uh DK D is this is a +1 12 and e - + + align:start position:0% + + + + align:start position:0% + +one2 so this is a + + align:start position:0% + + + + align:start position:0% + +overall integrate over + + align:start position:0% +overall integrate over + + + align:start position:0% +overall integrate over +de now I'm going to erase + + align:start position:0% + + + + align:start position:0% + +this so what I've written down is really + + align:start position:0% +this so what I've written down is really + + + align:start position:0% +this so what I've written down is really +what's + + align:start position:0% +what's + + + align:start position:0% +what's +inside the this I convert the K into E I + + align:start position:0% +inside the this I convert the K into E I + + + align:start position:0% +inside the this I convert the K into E I +convert DK D or write it also in terms + + align:start position:0% +convert DK D or write it also in terms + + + align:start position:0% +convert DK D or write it also in terms +of e so that at the end I have all that + + align:start position:0% +of e so that at the end I have all that + + + align:start position:0% +of e so that at the end I have all that +blob is my d sub + + align:start position:0% +blob is my d sub + + + align:start position:0% +blob is my d sub +state right so here is what's my dens of + + align:start position:0% +state right so here is what's my dens of + + + align:start position:0% +state right so here is what's my dens of +States you see 2 m h bar squ that's + + align:start position:0% +States you see 2 m h bar squ that's + + + align:start position:0% +States you see 2 m h bar squ that's +three halves and uh uh + + align:start position:0% +three halves and uh uh + + + align:start position:0% +three halves and uh uh +um so and the E and the E Min 12 so my + + align:start position:0% +um so and the E and the E Min 12 so my + + + align:start position:0% +um so and the E and the E Min 12 so my +density of states + + align:start position:0% + + + + align:start position:0% + +is if you I just want to check + + align:start position:0% +is if you I just want to check + + + align:start position:0% +is if you I just want to check +everything is written it should be + + align:start position:0% +everything is written it should be + + + align:start position:0% +everything is written it should be +correct okay um so what I have here is 2 + + align:start position:0% +correct okay um so what I have here is 2 + + + align:start position:0% +correct okay um so what I have here is 2 +pi + + align:start position:0% +pi + + + align:start position:0% +pi +squar and u m + + align:start position:0% +squar and u m + + + align:start position:0% +squar and u m +star 2 m over H bar + + align:start position:0% +star 2 m over H bar + + + align:start position:0% +star 2 m over H bar +square and three + + align:start position:0% +square and three + + + align:start position:0% +square and three +halfes and uh + + align:start position:0% +halfes and uh + + + align:start position:0% +halfes and uh +e m E2 so this is my D + + align:start position:0% +e m E2 so this is my D + + + align:start position:0% +e m E2 so this is my D +substate and this e is referring to my + + align:start position:0% +substate and this e is referring to my + + + align:start position:0% +substate and this e is referring to my +uh zero is at the bottom e say if I take + + align:start position:0% +uh zero is at the bottom e say if I take + + + align:start position:0% +uh zero is at the bottom e say if I take +my zero at a different location I have + + align:start position:0% +my zero at a different location I have + + + align:start position:0% +my zero at a different location I have +to do e Min e + + align:start position:0% +to do e Min e + + + align:start position:0% +to do e Min e +say + + align:start position:0% +say + + + align:start position:0% +say +okay so if + + align:start position:0% +okay so if + + + align:start position:0% +okay so if +you many many times when I was just + + align:start position:0% +you many many times when I was just + + + align:start position:0% +you many many times when I was just +learning this I just say okay I forgot + + align:start position:0% +learning this I just say okay I forgot + + + align:start position:0% +learning this I just say okay I forgot +it I went back I to the book I do a + + align:start position:0% +it I went back I to the book I do a + + + align:start position:0% +it I went back I to the book I do a +derivation and I plug in here because at + + align:start position:0% +derivation and I plug in here because at + + + align:start position:0% +derivation and I plug in here because at +the end you want to do this f * D and + + align:start position:0% +the end you want to do this f * D and + + + align:start position:0% +the end you want to do this f * D and +integrate the over + + align:start position:0% +integrate the over + + + align:start position:0% +integrate the over +energy but say now I can comfortably sit + + align:start position:0% +energy but say now I can comfortably sit + + + align:start position:0% +energy but say now I can comfortably sit +there and every time I forget I say I + + align:start position:0% +there and every time I forget I say I + + + align:start position:0% +there and every time I forget I say I +redo my summation to integration + + align:start position:0% +redo my summation to integration + + + align:start position:0% +redo my summation to integration +conversion okay it takes many times + + align:start position:0% +conversion okay it takes many times + + + align:start position:0% +conversion okay it takes many times +so that's the den + + align:start position:0% +so that's the den + + + align:start position:0% +so that's the den +state right and uh of course now I want + + align:start position:0% +state right and uh of course now I want + + + align:start position:0% +state right and uh of course now I want +to find out where is EF right so here if + + align:start position:0% +to find out where is EF right so here if + + + align:start position:0% +to find out where is EF right so here if +you if you say this is your EF you put + + align:start position:0% +you if you say this is your EF you put + + + align:start position:0% +you if you say this is your EF you put +it in this D of states is d e d de right + + align:start position:0% +it in this D of states is d e d de right + + + align:start position:0% +it in this D of states is d e d de right +essentially what I have here is zero EF + + align:start position:0% +essentially what I have here is zero EF + + + align:start position:0% +essentially what I have here is zero EF +d + + align:start position:0% +d + + + align:start position:0% +d +d many times people get familiar this is + + align:start position:0% +d many times people get familiar this is + + + align:start position:0% +d many times people get familiar this is +where they start + + align:start position:0% +where they start + + + align:start position:0% +where they start +right I want to find out where is the EF + + align:start position:0% +right I want to find out where is the EF + + + align:start position:0% +right I want to find out where is the EF +give me the number of electron I write D + + align:start position:0% +give me the number of electron I write D + + + align:start position:0% +give me the number of electron I write D +of State I integrate over e that's how + + align:start position:0% +of State I integrate over e that's how + + + align:start position:0% +of State I integrate over e that's how +many states I have right each state I + + align:start position:0% +many states I have right each state I + + + align:start position:0% +many states I have right each state I +have one electron so that's the how many + + align:start position:0% +have one electron so that's the how many + + + align:start position:0% +have one electron so that's the how many +electron I have and with that you go to + + align:start position:0% +electron I have and with that you go to + + + align:start position:0% +electron I have and with that you go to +do your integration you say this is a + + align:start position:0% +do your integration you say this is a + + + align:start position:0% +do your integration you say this is a +constant you can take out it's really e + + align:start position:0% +constant you can take out it's really e + + + align:start position:0% +constant you can take out it's really e +half integration over + + align:start position:0% +half integration over + + + align:start position:0% +half integration over +e uh D and to zero to EF + + align:start position:0% +e uh D and to zero to EF + + + align:start position:0% +e uh D and to zero to EF +right so this will give you where is + + align:start position:0% +right so this will give you where is + + + align:start position:0% +right so this will give you where is +your form + + align:start position:0% +your form + + + align:start position:0% +your form +level you do your integration you find + + align:start position:0% +level you do your integration you find + + + align:start position:0% +level you do your integration you find +out your + + align:start position:0% +out your + + + align:start position:0% +out your +EF equal 3 Pi s n 23 uh and H bar Square + + align:start position:0% +EF equal 3 Pi s n 23 uh and H bar Square + + + align:start position:0% +EF equal 3 Pi s n 23 uh and H bar Square + + align:start position:0% + + + + align:start position:0% + +m that's after you do your integration + + align:start position:0% +m that's after you do your integration + + + align:start position:0% +m that's after you do your integration +and inverse writing in terms of EF + + align:start position:0% + + + + align:start position:0% + +okay any question + + align:start position:0% +okay any question + + + align:start position:0% +okay any question +here it's converting summation into + + align:start position:0% +here it's converting summation into + + + align:start position:0% +here it's converting summation into +integration do the correct accounting + + align:start position:0% +integration do the correct accounting + + + align:start position:0% +integration do the correct accounting +the density of States tells you the L of + + align:start position:0% +the density of States tells you the L of + + + align:start position:0% +the density of States tells you the L of +quantum State per energy interval per V + + align:start position:0% +quantum State per energy interval per V + + + align:start position:0% +quantum State per energy interval per V +Vector interval per frequency interval + + align:start position:0% +Vector interval per frequency interval + + + align:start position:0% +Vector interval per frequency interval +many ways to write + + align:start position:0% +many ways to write + + + align:start position:0% +many ways to write +it + + align:start position:0% +it + + + align:start position:0% +it +okay so + + align:start position:0% + + + + align:start position:0% + +and just a + + align:start position:0% +and just a + + + align:start position:0% +and just a +comment right and let me write the let + + align:start position:0% +comment right and let me write the let + + + align:start position:0% +comment right and let me write the let +me draw the D self state for + + align:start position:0% +me draw the D self state for + + + align:start position:0% +me draw the D self state for +electron this is the + + align:start position:0% +electron this is the + + + align:start position:0% +electron this is the +energy this is + + align:start position:0% +energy this is + + + align:start position:0% +energy this is +d right and uh if I have energies + + align:start position:0% +d right and uh if I have energies + + + align:start position:0% +d right and uh if I have energies +relative to e say this is e minus E say + + align:start position:0% +relative to e say this is e minus E say + + + align:start position:0% +relative to e say this is e minus E say +so I I uh I put my e say not that the + + align:start position:0% +so I I uh I put my e say not that the + + + align:start position:0% +so I I uh I put my e say not that the +zero but at the arbitrary point then + + align:start position:0% +zero but at the arbitrary point then + + + align:start position:0% +zero but at the arbitrary point then +this is the paraba dens of state that's + + align:start position:0% +this is the paraba dens of state that's + + + align:start position:0% +this is the paraba dens of state that's +the shape of the install State because + + align:start position:0% +the shape of the install State because + + + align:start position:0% +the shape of the install State because +it's square + + align:start position:0% +it's square + + + align:start position:0% +it's square +root okay that's because if you see at + + align:start position:0% +root okay that's because if you see at + + + align:start position:0% +root okay that's because if you see at +the + + align:start position:0% +the + + + align:start position:0% +the +bottom there are not many states but you + + align:start position:0% +bottom there are not many states but you + + + align:start position:0% +bottom there are not many states but you +increase energy there are a lot more + + align:start position:0% +increase energy there are a lot more + + + align:start position:0% +increase energy there are a lot more +State uh states that have same energy + + align:start position:0% + + + + align:start position:0% + +values okay so now let's do the same for + + align:start position:0% +values okay so now let's do the same for + + + align:start position:0% +values okay so now let's do the same for +Fong conceptually you follow the same + + align:start position:0% +Fong conceptually you follow the same + + + align:start position:0% +Fong conceptually you follow the same +same process + + align:start position:0% +same process + + + align:start position:0% +same process +converting this summation into + + align:start position:0% + + + + align:start position:0% + +integration okay so uh I'm going to look + + align:start position:0% +integration okay so uh I'm going to look + + + align:start position:0% +integration okay so uh I'm going to look +at the Fong + + align:start position:0% + + + + align:start position:0% + +and I'm uh using the bu + + align:start position:0% + + + + align:start position:0% + +model and the B model say Omega = way * + + align:start position:0% +model and the B model say Omega = way * + + + align:start position:0% +model and the B model say Omega = way * +K and this K is the + + align:start position:0% +K and this K is the + + + align:start position:0% +K and this K is the +magnitude of the V Vector right so it's + + align:start position:0% +magnitude of the V Vector right so it's + + + align:start position:0% +magnitude of the V Vector right so it's +a square root of KX s + k y sare plus KZ + + align:start position:0% +a square root of KX s + k y sare plus KZ + + + align:start position:0% +a square root of KX s + k y sare plus KZ +squ and also in this case the Fons are d + + align:start position:0% +squ and also in this case the Fons are d + + + align:start position:0% +squ and also in this case the Fons are d +generate three + + align:start position:0% +generate three + + + align:start position:0% +generate three +polarizations transverse to longitudinal + + align:start position:0% +polarizations transverse to longitudinal + + + align:start position:0% +polarizations transverse to longitudinal +one and thatby just collap the all the + + align:start position:0% +one and thatby just collap the all the + + + align:start position:0% +one and thatby just collap the all the +three into one line there so but you + + align:start position:0% +three into one line there so but you + + + align:start position:0% +three into one line there so but you +should still know there are three + + align:start position:0% + + + + align:start position:0% + +polarizations okay so in that case if + + align:start position:0% +polarizations okay so in that case if + + + align:start position:0% +polarizations okay so in that case if +you go back to starting from my + + align:start position:0% +you go back to starting from my + + + align:start position:0% +you go back to starting from my +summation whatever function right and + + align:start position:0% +summation whatever function right and + + + align:start position:0% +summation whatever function right and +let's forget about the what I'm going to + + align:start position:0% +let's forget about the what I'm going to + + + align:start position:0% +let's forget about the what I'm going to +integrate because right now I don't have + + align:start position:0% +integrate because right now I don't have + + + align:start position:0% +integrate because right now I don't have +good L good stuff of f for you yet I'm + + align:start position:0% +good L good stuff of f for you yet I'm + + + align:start position:0% +good L good stuff of f for you yet I'm +going to we need to go to uh the uh say + + align:start position:0% +going to we need to go to uh the uh say + + + align:start position:0% +going to we need to go to uh the uh say +statistical distribution to say uh to + + align:start position:0% +statistical distribution to say uh to + + + align:start position:0% +statistical distribution to say uh to +actually give you f + + align:start position:0% +actually give you f + + + align:start position:0% +actually give you f +example right so I convert that + + align:start position:0% +example right so I convert that + + + align:start position:0% +example right so I convert that +summation into integration + + align:start position:0% +summation into integration + + + align:start position:0% +summation into integration +same but that factor of two which is a + + align:start position:0% +same but that factor of two which is a + + + align:start position:0% +same but that factor of two which is a +spin for + + align:start position:0% +spin for + + + align:start position:0% +spin for +electron need to become a factor of + + align:start position:0% +electron need to become a factor of + + + align:start position:0% +electron need to become a factor of +three because I have a polarization + + align:start position:0% +three because I have a polarization + + + align:start position:0% +three because I have a polarization +three the B model I have three + + align:start position:0% +three the B model I have three + + + align:start position:0% +three the B model I have three +polarization right + + align:start position:0% +polarization right + + + align:start position:0% +polarization right +okay for each KX KY KZ I have three + + align:start position:0% +okay for each KX KY KZ I have three + + + align:start position:0% +okay for each KX KY KZ I have three +polarization so I have three that's + + align:start position:0% +polarization so I have three that's + + + align:start position:0% +polarization so I have three that's +where my factor of three so if you look + + align:start position:0% +where my factor of three so if you look + + + align:start position:0% +where my factor of three so if you look +at my + + align:start position:0% +at my + + + align:start position:0% +at my +DK uh that's uh where is my DK here this + + align:start position:0% +DK uh that's uh where is my DK here this + + + align:start position:0% +DK uh that's uh where is my DK here this +is my dens of dek before is a factor of + + align:start position:0% +is my dens of dek before is a factor of + + + align:start position:0% +is my dens of dek before is a factor of +two now it's a factor of three so that + + align:start position:0% +two now it's a factor of three so that + + + align:start position:0% +two now it's a factor of three so that +should be three halfs of this so my DK + + align:start position:0% +should be three halfs of this so my DK + + + align:start position:0% +should be three halfs of this so my DK +density of states for forong + + align:start position:0% +density of states for forong + + + align:start position:0% +density of states for forong +is three halfes what I have here is K + + align:start position:0% +is three halfes what I have here is K + + + align:start position:0% +is three halfes what I have here is K +Square Pi + + align:start position:0% + + + + align:start position:0% + +square right now my D + + align:start position:0% +square right now my D + + + align:start position:0% +square right now my D +Omega is + + align:start position:0% +Omega is + + + align:start position:0% +Omega is +DK and + + align:start position:0% +DK and + + + align:start position:0% +DK and +DK D Omega so this is written eventually + + align:start position:0% +DK D Omega so this is written eventually + + + align:start position:0% +DK D Omega so this is written eventually +has to be changed + + align:start position:0% +has to be changed + + + align:start position:0% +has to be changed +into K has to be changing into + + align:start position:0% +into K has to be changing into + + + align:start position:0% +into K has to be changing into +Omega right now I'm going to do + + align:start position:0% +Omega right now I'm going to do + + + align:start position:0% +Omega right now I'm going to do +frequency + + align:start position:0% +frequency + + + align:start position:0% +frequency +integration right for I normally don't + + align:start position:0% +integration right for I normally don't + + + align:start position:0% +integration right for I normally don't +do D my habit is typically do D Omega + + align:start position:0% +do D my habit is typically do D Omega + + + align:start position:0% +do D my habit is typically do D Omega +now I do DK D Omega right so DK D Omega + + align:start position:0% +now I do DK D Omega right so DK D Omega + + + align:start position:0% +now I do DK D Omega right so DK D Omega +so uh DK is 3 half K is Omega over V + + align:start position:0% +so uh DK is 3 half K is Omega over V + + + align:start position:0% +so uh DK is 3 half K is Omega over V +here Square Pi square and DK D + + align:start position:0% +here Square Pi square and DK D + + + align:start position:0% +here Square Pi square and DK D +Omega is 1 + + align:start position:0% +Omega is 1 + + + align:start position:0% +Omega is 1 +weight + + align:start position:0% + + + + align:start position:0% + +right okay so with that I will get the + + align:start position:0% +right okay so with that I will get the + + + align:start position:0% +right okay so with that I will get the +three half pi Square V cubic Omega + + align:start position:0% +three half pi Square V cubic Omega + + + align:start position:0% +three half pi Square V cubic Omega +Square so this is den of + + align:start position:0% +Square so this is den of + + + align:start position:0% +Square so this is den of +states for + + align:start position:0% + + + + align:start position:0% + +form + + align:start position:0% +form + + + align:start position:0% +form +and here is + + align:start position:0% +and here is + + + align:start position:0% +and here is +D Omega and here is Omega so it's a it's + + align:start position:0% +D Omega and here is Omega so it's a it's + + + align:start position:0% +D Omega and here is Omega so it's a it's +the uh Parabola it's not square root + + align:start position:0% +the uh Parabola it's not square root + + + align:start position:0% +the uh Parabola it's not square root +then of states for electron is square + + align:start position:0% +then of states for electron is square + + + align:start position:0% +then of states for electron is square +root of energy right here is actually + + align:start position:0% +root of energy right here is actually + + + align:start position:0% +root of energy right here is actually +square of + + align:start position:0% +square of + + + align:start position:0% +square of +energy + + align:start position:0% +energy + + + align:start position:0% +energy +okay so different dispersion give you + + align:start position:0% +okay so different dispersion give you + + + align:start position:0% +okay so different dispersion give you +different density of + + align:start position:0% +different density of + + + align:start position:0% +different density of +States now this this could be easily + + align:start position:0% +States now this this could be easily + + + align:start position:0% +States now this this could be easily +converted into + + align:start position:0% +converted into + + + align:start position:0% +converted into +Photon + + align:start position:0% +Photon + + + align:start position:0% +Photon +Photon now try allow longitudinal + + align:start position:0% +Photon now try allow longitudinal + + + align:start position:0% +Photon now try allow longitudinal +electromagnetic wave right only two + + align:start position:0% +electromagnetic wave right only two + + + align:start position:0% +electromagnetic wave right only two +polarization two transverse + + align:start position:0% + + + + align:start position:0% + +waves okay and that two transverse wave + + align:start position:0% +waves okay and that two transverse wave + + + align:start position:0% +waves okay and that two transverse wave +should not be three it should be + + align:start position:0% +should not be three it should be + + + align:start position:0% +should not be three it should be +two and the speed of sun becomes speed + + align:start position:0% +two and the speed of sun becomes speed + + + align:start position:0% +two and the speed of sun becomes speed +of + + align:start position:0% +of + + + align:start position:0% +of +light right so for photon + + align:start position:0% + + + + align:start position:0% + +density of State in terms of frequency + + align:start position:0% +density of State in terms of frequency + + + align:start position:0% +density of State in terms of frequency +is just Omega Square Pi Square C + + align:start position:0% +is just Omega Square Pi Square C + + + align:start position:0% +is just Omega Square Pi Square C +cubic okay the best is so you see there + + align:start position:0% +cubic okay the best is so you see there + + + align:start position:0% +cubic okay the best is so you see there +and write through all + + align:start position:0% +and write through all + + + align:start position:0% +and write through all +this right getting yourself comfortable + + align:start position:0% +this right getting yourself comfortable + + + align:start position:0% +this right getting yourself comfortable +it's mathematics it's not much really + + align:start position:0% +it's mathematics it's not much really + + + align:start position:0% +it's mathematics it's not much really +not much + + align:start position:0% + + + + align:start position:0% + +physics + + align:start position:0% +physics + + + align:start position:0% +physics +Okay so uh that's the uh case of 3D + + align:start position:0% +Okay so uh that's the uh case of 3D + + + align:start position:0% +Okay so uh that's the uh case of 3D +structure now let's do a + + align:start position:0% +structure now let's do a + + + align:start position:0% +structure now let's do a +2d I'm doing okay uh so we say uh let's + + align:start position:0% +2d I'm doing okay uh so we say uh let's + + + align:start position:0% +2d I'm doing okay uh so we say uh let's +look at a Quantum well let's look at + + align:start position:0% +look at a Quantum well let's look at + + + align:start position:0% +look at a Quantum well let's look at +thin film what will be the quantization + + align:start position:0% +thin film what will be the quantization + + + align:start position:0% +thin film what will be the quantization +effect on the density of + + align:start position:0% + + + + align:start position:0% + +States okay so let's do a + + align:start position:0% +States okay so let's do a + + + align:start position:0% +States okay so let's do a +2d + + align:start position:0% +2d + + + align:start position:0% +2d +uh I'm putting + + align:start position:0% + + + + align:start position:0% + +here this is best + + align:start position:0% + + + + align:start position:0% + +place uh I'm going to do a Quantum + + align:start position:0% + + + + align:start position:0% + +well okay and before when we talk about + + align:start position:0% +well okay and before when we talk about + + + align:start position:0% +well okay and before when we talk about +Quantum well we say just a + + align:start position:0% +Quantum well we say just a + + + align:start position:0% +Quantum well we say just a +onedimensional Quantum well now I'm + + align:start position:0% +onedimensional Quantum well now I'm + + + align:start position:0% +onedimensional Quantum well now I'm +going to give you more realistic a f + + align:start position:0% +going to give you more realistic a f + + + align:start position:0% +going to give you more realistic a f +right in the case of film electron can + + align:start position:0% +right in the case of film electron can + + + align:start position:0% +right in the case of film electron can +move in + + align:start position:0% +move in + + + align:start position:0% +move in +XYZ three + + align:start position:0% +XYZ three + + + align:start position:0% +XYZ three +dimension and uh so if I have a + + align:start position:0% +dimension and uh so if I have a + + + align:start position:0% +dimension and uh so if I have a +film and in the thickness Direction I + + align:start position:0% +film and in the thickness Direction I + + + align:start position:0% +film and in the thickness Direction I +have + + align:start position:0% + + + + align:start position:0% + +LZ + + align:start position:0% +LZ + + + align:start position:0% +LZ +okay and uh in the XY Direction uh I + + align:start position:0% +okay and uh in the XY Direction uh I + + + align:start position:0% +okay and uh in the XY Direction uh I +have have free Move Motion I don't have + + align:start position:0% +have have free Move Motion I don't have + + + align:start position:0% +have have free Move Motion I don't have +constraint right so uh uh my energy + + align:start position:0% +constraint right so uh uh my energy + + + align:start position:0% +constraint right so uh uh my energy +relation will be + + align:start position:0% +relation will be + + + align:start position:0% +relation will be +KX KY in the XY Direction I have discret + + align:start position:0% +KX KY in the XY Direction I have discret + + + align:start position:0% +KX KY in the XY Direction I have discret +Point as what we had before but say that + + align:start position:0% +Point as what we had before but say that + + + align:start position:0% +Point as what we had before but say that +2 pi LX 2 pi l y right that's my + + align:start position:0% +2 pi LX 2 pi l y right that's my + + + align:start position:0% +2 pi LX 2 pi l y right that's my +separation but my LX l y in the XY + + align:start position:0% +separation but my LX l y in the XY + + + align:start position:0% +separation but my LX l y in the XY +direction are minim + + align:start position:0% +direction are minim + + + align:start position:0% +direction are minim +M or right that's a + + align:start position:0% +M or right that's a + + + align:start position:0% +M or right that's a +macroscopic so that separation is very + + align:start position:0% +macroscopic so that separation is very + + + align:start position:0% +macroscopic so that separation is very +small on the Z Direction I'm unstr + + align:start position:0% +small on the Z Direction I'm unstr + + + align:start position:0% +small on the Z Direction I'm unstr +strong 100 unstr + + align:start position:0% +strong 100 unstr + + + align:start position:0% +strong 100 unstr +strong right so in that case recall that + + align:start position:0% +strong right so in that case recall that + + + align:start position:0% +strong right so in that case recall that +when we discuss the energy in this + + align:start position:0% +when we discuss the energy in this + + + align:start position:0% +when we discuss the energy in this +direction is standing wave right so uh n + + align:start position:0% +direction is standing wave right so uh n + + + align:start position:0% +direction is standing wave right so uh n +z and let me just use n Lambda / 2 + + align:start position:0% +z and let me just use n Lambda / 2 + + + align:start position:0% +z and let me just use n Lambda / 2 +equals + + align:start position:0% + + + + align:start position:0% + +LZ right and uh that means Lambda equals + + align:start position:0% +LZ right and uh that means Lambda equals + + + align:start position:0% +LZ right and uh that means Lambda equals +l z + + align:start position:0% +l z + + + align:start position:0% +l z +2ide by n and you can convert this uh + + align:start position:0% +2ide by n and you can convert this uh + + + align:start position:0% +2ide by n and you can convert this uh +back into energy right HP say uh uh the + + align:start position:0% +back into energy right HP say uh uh the + + + align:start position:0% +back into energy right HP say uh uh the +momentum k = 2 pi/ Lambda and what do + + align:start position:0% +momentum k = 2 pi/ Lambda and what do + + + align:start position:0% +momentum k = 2 pi/ Lambda and what do +you have here uh 2 pi over Lambda Lambda + + align:start position:0% +you have here uh 2 pi over Lambda Lambda + + + align:start position:0% +you have here uh 2 pi over Lambda Lambda +is there so I have m pi over + + align:start position:0% + + + + align:start position:0% + +LZ + + align:start position:0% +LZ + + + align:start position:0% +LZ +right and the separation between this is + + align:start position:0% +right and the separation between this is + + + align:start position:0% +right and the separation between this is +my K in the Z dire separation is become + + align:start position:0% +my K in the Z dire separation is become + + + align:start position:0% +my K in the Z dire separation is become +pi/ + + align:start position:0% +pi/ + + + align:start position:0% +pi/ +LZ now if you look at the separation we + + align:start position:0% +LZ now if you look at the separation we + + + align:start position:0% +LZ now if you look at the separation we +say in the unconstraint case KX 2 + + align:start position:0% +say in the unconstraint case KX 2 + + + align:start position:0% +say in the unconstraint case KX 2 +pi LX Over + + align:start position:0% +pi LX Over + + + align:start position:0% +pi LX Over +N + + align:start position:0% +N + + + align:start position:0% +N +right so in the unconstraint case is I + + align:start position:0% +right so in the unconstraint case is I + + + align:start position:0% +right so in the unconstraint case is I +have plus + + align:start position:0% +have plus + + + align:start position:0% +have plus +minus and the separation is 2 pi/ LX in + + align:start position:0% +minus and the separation is 2 pi/ LX in + + + align:start position:0% +minus and the separation is 2 pi/ LX in +the constraint case I have n is only + + align:start position:0% +the constraint case I have n is only + + + align:start position:0% +the constraint case I have n is only +plus okay and the separation is pi over + + align:start position:0% +plus okay and the separation is pi over + + + align:start position:0% +plus okay and the separation is pi over +LZ it's a is a factor of two difference + + align:start position:0% +LZ it's a is a factor of two difference + + + align:start position:0% +LZ it's a is a factor of two difference +that's because I'm using a traveling + + align:start position:0% +that's because I'm using a traveling + + + align:start position:0% +that's because I'm using a traveling +wave this traveling wave positive + + align:start position:0% +wave this traveling wave positive + + + align:start position:0% +wave this traveling wave positive +negative + + align:start position:0% +negative + + + align:start position:0% +negative +direction to construct a standing wave + + align:start position:0% +direction to construct a standing wave + + + align:start position:0% +direction to construct a standing wave +right so it's actually equivalent + + align:start position:0% +right so it's actually equivalent + + + align:start position:0% +right so it's actually equivalent +whether I use plus + + align:start position:0% +whether I use plus + + + align:start position:0% +whether I use plus +minus in the case or whether I use + + align:start position:0% +minus in the case or whether I use + + + align:start position:0% +minus in the case or whether I use +standing way but in the case of small + + align:start position:0% +standing way but in the case of small + + + align:start position:0% +standing way but in the case of small +length l z I have to look at the + + align:start position:0% +length l z I have to look at the + + + align:start position:0% +length l z I have to look at the +separation because that summation cannot + + align:start position:0% +separation because that summation cannot + + + align:start position:0% +separation because that summation cannot +be converted into integration so this is + + align:start position:0% +be converted into integration so this is + + + align:start position:0% +be converted into integration so this is +the difference so if I write in that + + align:start position:0% +the difference so if I write in that + + + align:start position:0% +the difference so if I write in that +case I'll write my energy is + + align:start position:0% +case I'll write my energy is + + + align:start position:0% +case I'll write my energy is +h² uh say KX + + align:start position:0% +h² uh say KX + + + align:start position:0% +h² uh say KX +s+ k y 2 that's in the so effective mass + + align:start position:0% +s+ k y 2 that's in the so effective mass + + + align:start position:0% +s+ k y 2 that's in the so effective mass +in the implant + + align:start position:0% +in the implant + + + align:start position:0% +in the implant +Direction in the XY + + align:start position:0% +Direction in the XY + + + align:start position:0% +Direction in the XY +Direction okay and in the Z Direction + + align:start position:0% +Direction okay and in the Z Direction + + + align:start position:0% +Direction okay and in the Z Direction +and I have if I use this I can do uh my + + align:start position:0% +and I have if I use this I can do uh my + + + align:start position:0% +and I have if I use this I can do uh my +energy quantization right is HK / by HK + + align:start position:0% +energy quantization right is HK / by HK + + + align:start position:0% +energy quantization right is HK / by HK +2 / 2 m so 12 uh m h K Square + + align:start position:0% +2 / 2 m so 12 uh m h K Square + + + align:start position:0% +2 / 2 m so 12 uh m h K Square +h² K square is m pi/ l z square right n + + align:start position:0% +h² K square is m pi/ l z square right n + + + align:start position:0% +h² K square is m pi/ l z square right n +equals uh 1 + + align:start position:0% + + + + align:start position:0% + +2 okay so this is my energy level I'm + + align:start position:0% +2 okay so this is my energy level I'm + + + align:start position:0% +2 okay so this is my energy level I'm +still writing h² KZ Square KZ Square now + + align:start position:0% +still writing h² KZ Square KZ Square now + + + align:start position:0% +still writing h² KZ Square KZ Square now +I do a standing way + + align:start position:0% +I do a standing way + + + align:start position:0% +I do a standing way +and because my LZ is very + + align:start position:0% +and because my LZ is very + + + align:start position:0% +and because my LZ is very +small so between the two n uh uh + + align:start position:0% +small so between the two n uh uh + + + align:start position:0% +small so between the two n uh uh +consecutive n there could be many KX + + align:start position:0% + + + + align:start position:0% + +KY okay so if you look at this what I + + align:start position:0% +KY okay so if you look at this what I + + + align:start position:0% +KY okay so if you look at this what I +what I have here recall in a + + align:start position:0% +what I have here recall in a + + + align:start position:0% +what I have here recall in a +3D right a spherical say we say a + + align:start position:0% +3D right a spherical say we say a + + + align:start position:0% +3D right a spherical say we say a +constant energy surface is a sphere + + align:start position:0% +constant energy surface is a sphere + + + align:start position:0% +constant energy surface is a sphere +right now I have a constant energy + + align:start position:0% +right now I have a constant energy + + + align:start position:0% +right now I have a constant energy +surface is XY plan is a circle but then + + align:start position:0% +surface is XY plan is a circle but then + + + align:start position:0% +surface is XY plan is a circle but then +depends on the N value I have jumps + + align:start position:0% +depends on the N value I have jumps + + + align:start position:0% +depends on the N value I have jumps +different + + align:start position:0% +different + + + align:start position:0% +different +values okay depends on the different + + align:start position:0% +values okay depends on the different + + + align:start position:0% +values okay depends on the different +energy so the other way to think about + + align:start position:0% +energy so the other way to think about + + + align:start position:0% +energy so the other way to think about +this Nal 1 so uh this is where we draw + + align:start position:0% +this Nal 1 so uh this is where we draw + + + align:start position:0% +this Nal 1 so uh this is where we draw +quantization effect this is you say + + align:start position:0% +quantization effect this is you say + + + align:start position:0% +quantization effect this is you say +before that's a + + align:start position:0% +before that's a + + + align:start position:0% +before that's a +bulk right that's a bulk of course I'm + + align:start position:0% +bulk right that's a bulk of course I'm + + + align:start position:0% +bulk right that's a bulk of course I'm +only drawing One Direction + + align:start position:0% +only drawing One Direction + + + align:start position:0% +only drawing One Direction +okay but you have to think this is a KX + + align:start position:0% +okay but you have to think this is a KX + + + align:start position:0% +okay but you have to think this is a KX +KY is a is like so you do a + + align:start position:0% +KY is a is like so you do a + + + align:start position:0% +KY is a is like so you do a +rotation right so + + align:start position:0% + + + + align:start position:0% + +here and they when I have quantization + + align:start position:0% +here and they when I have quantization + + + align:start position:0% +here and they when I have quantization +it turns out that the minimum energy not + + align:start position:0% +it turns out that the minimum energy not + + + align:start position:0% +it turns out that the minimum energy not +can not longer be here because nals 1 + + align:start position:0% +can not longer be here because nals 1 + + + align:start position:0% +can not longer be here because nals 1 +that gives me the first + + align:start position:0% +that gives me the first + + + align:start position:0% +that gives me the first +level right so the bottom of the + + align:start position:0% +level right so the bottom of the + + + align:start position:0% +level right so the bottom of the +conduction B actually will shift + + align:start position:0% +conduction B actually will shift + + + align:start position:0% +conduction B actually will shift +up right so that's why sometimes people + + align:start position:0% +up right so that's why sometimes people + + + align:start position:0% +up right so that's why sometimes people +say uh how I can open a + + align:start position:0% +say uh how I can open a + + + align:start position:0% +say uh how I can open a +gap when I have quantization I can + + align:start position:0% +gap when I have quantization I can + + + align:start position:0% +gap when I have quantization I can +artificially turn even a sem metal into + + align:start position:0% +artificially turn even a sem metal into + + + align:start position:0% +artificially turn even a sem metal into +semiconductor let me give you one one + + align:start position:0% +semiconductor let me give you one one + + + align:start position:0% +semiconductor let me give you one one +idea for example when we work on theral + + align:start position:0% +idea for example when we work on theral + + + align:start position:0% +idea for example when we work on theral +electrics uh there's a material bism + + align:start position:0% +electrics uh there's a material bism + + + align:start position:0% +electrics uh there's a material bism +turns out bism is like + + align:start position:0% +turns out bism is like + + + align:start position:0% +turns out bism is like +this right it's a Sim + + align:start position:0% +this right it's a Sim + + + align:start position:0% +this right it's a Sim +metal the uh there there's no Gap this + + align:start position:0% +metal the uh there there's no Gap this + + + align:start position:0% +metal the uh there there's no Gap this +is the top of Valance bottom conduction + + align:start position:0% +is the top of Valance bottom conduction + + + align:start position:0% +is the top of Valance bottom conduction +conduction band is below Valance band so + + align:start position:0% +conduction band is below Valance band so + + + align:start position:0% +conduction band is below Valance band so +in this the form level is around here + + align:start position:0% +in this the form level is around here + + + align:start position:0% +in this the form level is around here +and there's no Gap it's a s metal right + + align:start position:0% +and there's no Gap it's a s metal right + + + align:start position:0% +and there's no Gap it's a s metal right +s metal is not good for Thal + + align:start position:0% +s metal is not good for Thal + + + align:start position:0% +s metal is not good for Thal +electrics and uh because when + + align:start position:0% +electrics and uh because when + + + align:start position:0% +electrics and uh because when +electron in this H in this this still + + align:start position:0% +electron in this H in this this still + + + align:start position:0% +electron in this H in this this still +have you can still have electron + + align:start position:0% +have you can still have electron + + + align:start position:0% +have you can still have electron +holes and uh when they diffuse to the + + align:start position:0% +holes and uh when they diffuse to the + + + align:start position:0% +holes and uh when they diffuse to the +same + + align:start position:0% +same + + + align:start position:0% +same +direction the heat they cancel each + + align:start position:0% +direction the heat they cancel each + + + align:start position:0% +direction the heat they cancel each +other so it's not good so how we can + + align:start position:0% +other so it's not good so how we can + + + align:start position:0% +other so it's not good so how we can +create a bank Gap out of this + + align:start position:0% +create a bank Gap out of this + + + align:start position:0% +create a bank Gap out of this +material and uh you do a size effect so + + align:start position:0% +material and uh you do a size effect so + + + align:start position:0% +material and uh you do a size effect so +you make it smaller and theoretically + + align:start position:0% +you make it smaller and theoretically + + + align:start position:0% +you make it smaller and theoretically +what happens is this one is a function + + align:start position:0% +what happens is this one is a function + + + align:start position:0% +what happens is this one is a function +of diameter or thickness so this will + + align:start position:0% +of diameter or thickness so this will + + + align:start position:0% +of diameter or thickness so this will +move + + align:start position:0% +move + + + align:start position:0% +move +up depend on thickness this one will + + align:start position:0% +up depend on thickness this one will + + + align:start position:0% +up depend on thickness this one will +move + + align:start position:0% +move + + + align:start position:0% +move +down right so now you can create a + + align:start position:0% +down right so now you can create a + + + align:start position:0% +down right so now you can create a +gap and there also discussion for + + align:start position:0% +gap and there also discussion for + + + align:start position:0% +gap and there also discussion for +example + + align:start position:0% +example + + + align:start position:0% +example +silicon right silicon is like what you + + align:start position:0% +silicon right silicon is like what you + + + align:start position:0% +silicon right silicon is like what you +have here this is + + align:start position:0% +have here this is + + + align:start position:0% +have here this is +the this indirect Gap the valance band + + align:start position:0% +the this indirect Gap the valance band + + + align:start position:0% +the this indirect Gap the valance band +is here conduction band is here right + + align:start position:0% +is here conduction band is here right + + + align:start position:0% +is here conduction band is here right +there is another conduction band but + + align:start position:0% +there is another conduction band but + + + align:start position:0% +there is another conduction band but +it's it's not the minimum this is the + + align:start position:0% +it's it's not the minimum this is the + + + align:start position:0% +it's it's not the minimum this is the +minimum so now what you do you make a + + align:start position:0% +minimum so now what you do you make a + + + align:start position:0% +minimum so now what you do you make a +very small Doss and this will move up of + + align:start position:0% +very small Doss and this will move up of + + + align:start position:0% +very small Doss and this will move up of +course this will move down and this also + + align:start position:0% +course this will move down and this also + + + align:start position:0% +course this will move down and this also +move depends on the speed of moving + + align:start position:0% +move depends on the speed of moving + + + align:start position:0% +move depends on the speed of moving +that's related to the + + align:start position:0% +that's related to the + + + align:start position:0% +that's related to the +mass right and this could be move to + + align:start position:0% +mass right and this could be move to + + + align:start position:0% +mass right and this could be move to +here and this one move slower so this + + align:start position:0% +here and this one move slower so this + + + align:start position:0% +here and this one move slower so this +you can convert into direct + + align:start position:0% +you can convert into direct + + + align:start position:0% +you can convert into direct +Gap right so that's the beauty of this + + align:start position:0% +Gap right so that's the beauty of this + + + align:start position:0% +Gap right so that's the beauty of this +thinking about this Quantum size effect + + align:start position:0% +thinking about this Quantum size effect + + + align:start position:0% +thinking about this Quantum size effect +you can use that + + align:start position:0% +you can use that + + + align:start position:0% +you can use that +to tune the bank gap of the materials + + align:start position:0% +to tune the bank gap of the materials + + + align:start position:0% +to tune the bank gap of the materials +and that's uh when you make a say like + + align:start position:0% +and that's uh when you make a say like + + + align:start position:0% +and that's uh when you make a say like +Quantum dots like cat + + align:start position:0% +Quantum dots like cat + + + align:start position:0% +Quantum dots like cat +ter or cat uh uh uh + + align:start position:0% +ter or cat uh uh uh + + + align:start position:0% +ter or cat uh uh uh +sulfide canot cite cat sulfide or um if + + align:start position:0% +sulfide canot cite cat sulfide or um if + + + align:start position:0% +sulfide canot cite cat sulfide or um if +you look at the professor M Bend's + + align:start position:0% +you look at the professor M Bend's + + + align:start position:0% +you look at the professor M Bend's +website he has all this beautiful dots + + align:start position:0% +website he has all this beautiful dots + + + align:start position:0% +website he has all this beautiful dots +different + + align:start position:0% +different + + + align:start position:0% +different +colors and that's because the same + + align:start position:0% +colors and that's because the same + + + align:start position:0% +colors and that's because the same +material you change the size you can + + align:start position:0% +material you change the size you can + + + align:start position:0% +material you change the size you can +actually open make a different + + align:start position:0% +actually open make a different + + + align:start position:0% +actually open make a different +Gap + + align:start position:0% +Gap + + + align:start position:0% +Gap +okay so uh those are + + align:start position:0% +okay so uh those are + + + align:start position:0% +okay so uh those are +digression come come back to I want to + + align:start position:0% +digression come come back to I want to + + + align:start position:0% +digression come come back to I want to +find that what's the den sub state right + + align:start position:0% +find that what's the den sub state right + + + align:start position:0% +find that what's the den sub state right +so + + align:start position:0% +so + + + align:start position:0% +so +uh let me again start with okay I have + + align:start position:0% +uh let me again start with okay I have + + + align:start position:0% +uh let me again start with okay I have +here is L of electrons I give to + + align:start position:0% +here is L of electrons I give to + + + align:start position:0% +here is L of electrons I give to +this how much how many electron in the + + align:start position:0% +this how much how many electron in the + + + align:start position:0% +this how much how many electron in the +material and I still do my + + align:start position:0% +material and I still do my + + + align:start position:0% +material and I still do my +uh + + align:start position:0% +uh + + + align:start position:0% +uh +KX + + align:start position:0% +KX + + + align:start position:0% +KX +KY my + + align:start position:0% +KY my + + + align:start position:0% +KY my +KZ my f whatever F I have there function + + align:start position:0% +KZ my f whatever F I have there function + + + align:start position:0% +KZ my f whatever F I have there function +that I'm interested in + + align:start position:0% +that I'm interested in + + + align:start position:0% +that I'm interested in +integrating right and uh in + + align:start position:0% +integrating right and uh in + + + align:start position:0% +integrating right and uh in +3D I said this F is a very slow function + + align:start position:0% +3D I said this F is a very slow function + + + align:start position:0% +3D I said this F is a very slow function +of KX KY k z so I converted into + + align:start position:0% +of KX KY k z so I converted into + + + align:start position:0% +of KX KY k z so I converted into +integration but in 2D in the Z + + align:start position:0% +integration but in 2D in the Z + + + align:start position:0% +integration but in 2D in the Z +direction right turn two consecutive so + + align:start position:0% +direction right turn two consecutive so + + + align:start position:0% +direction right turn two consecutive so +this is you say and my first energy + + align:start position:0% +this is you say and my first energy + + + align:start position:0% +this is you say and my first energy +level is here my second energy level is + + align:start position:0% +level is here my second energy level is + + + align:start position:0% +level is here my second energy level is +here between these two there are many KX + + align:start position:0% +here between these two there are many KX + + + align:start position:0% +here between these two there are many KX +KY there are many states in between KX + + align:start position:0% +KY there are many states in between KX + + + align:start position:0% +KY there are many states in between KX +KY + + align:start position:0% +KY + + + align:start position:0% +KY +right so I cannot convert in the Z + + align:start position:0% +right so I cannot convert in the Z + + + align:start position:0% +right so I cannot convert in the Z +Direction into summation uh inte + + align:start position:0% +Direction into summation uh inte + + + align:start position:0% +Direction into summation uh inte +integration I need to keep that + + align:start position:0% +integration I need to keep that + + + align:start position:0% +integration I need to keep that +summation and then what I could do is + + align:start position:0% +summation and then what I could do is + + + align:start position:0% +summation and then what I could do is +only convert XY + + align:start position:0% +only convert XY + + + align:start position:0% +only convert XY +Direction into integral + + align:start position:0% + + + + align:start position:0% + +so this is what I'm going to do I'm + + align:start position:0% +so this is what I'm going to do I'm + + + align:start position:0% +so this is what I'm going to do I'm +going to keep my uh say uh summation in + + align:start position:0% +going to keep my uh say uh summation in + + + align:start position:0% +going to keep my uh say uh summation in +the X Direction I can still do so I have + + align:start position:0% +the X Direction I can still do so I have + + + align:start position:0% +the X Direction I can still do so I have +dkx 2 pi + + align:start position:0% +dkx 2 pi + + + align:start position:0% +dkx 2 pi +LX and Y Direction I still + + align:start position:0% +LX and Y Direction I still + + + align:start position:0% +LX and Y Direction I still +do dky 2 pi l y and z Direction I cannot + + align:start position:0% +do dky 2 pi l y and z Direction I cannot + + + align:start position:0% +do dky 2 pi l y and z Direction I cannot +do I'm going to keep my + + align:start position:0% +do I'm going to keep my + + + align:start position:0% +do I'm going to keep my +summation and rather than KZ I can also + + align:start position:0% +summation and rather than KZ I can also + + + align:start position:0% +summation and rather than KZ I can also +do n it's equivalent whether you do n + + align:start position:0% +do n it's equivalent whether you do n + + + align:start position:0% +do n it's equivalent whether you do n +notation or KZ notation + + align:start position:0% +notation or KZ notation + + + align:start position:0% +notation or KZ notation +right and uh whatever F I have a factor + + align:start position:0% +right and uh whatever F I have a factor + + + align:start position:0% +right and uh whatever F I have a factor +of two I move the + + align:start position:0% + + + + align:start position:0% + +inside + + align:start position:0% +inside + + + align:start position:0% +inside +right so now rather than do a 3D + + align:start position:0% +right so now rather than do a 3D + + + align:start position:0% +right so now rather than do a 3D +cartisan coordinate your mathematics is + + align:start position:0% +cartisan coordinate your mathematics is + + + align:start position:0% +cartisan coordinate your mathematics is +in 2D KX KY integration + + align:start position:0% +in 2D KX KY integration + + + align:start position:0% +in 2D KX KY integration +so you do a either polar + + align:start position:0% +so you do a either polar + + + align:start position:0% +so you do a either polar +coordinate or say depends on your F + + align:start position:0% +coordinate or say depends on your F + + + align:start position:0% +coordinate or say depends on your F +what's your f f is function e or it's + + align:start position:0% +what's your f f is function e or it's + + + align:start position:0% +what's your f f is function e or it's +right so that's your choice but let me + + align:start position:0% +right so that's your choice but let me + + + align:start position:0% +right so that's your choice but let me +I'm going to do here you say I have area + + align:start position:0% +I'm going to do here you say I have area + + + align:start position:0% +I'm going to do here you say I have area +LX * l y and if I do uh dkx dky I + + align:start position:0% +LX * l y and if I do uh dkx dky I + + + align:start position:0% +LX * l y and if I do uh dkx dky I +convert it into a polar coordinate right + + align:start position:0% +convert it into a polar coordinate right + + + align:start position:0% +convert it into a polar coordinate right +dkx dky in a polar uh if it's a + + align:start position:0% +dkx dky in a polar uh if it's a + + + align:start position:0% +dkx dky in a polar uh if it's a +symmetric it's 2 pi K + + align:start position:0% +symmetric it's 2 pi K + + + align:start position:0% +symmetric it's 2 pi K +DK right let's say k i i just make a + + align:start position:0% +DK right let's say k i i just make a + + + align:start position:0% +DK right let's say k i i just make a +notation KX s + k y s so it's 2D K + + align:start position:0% +notation KX s + k y s so it's 2D K + + + align:start position:0% +notation KX s + k y s so it's 2D K +parallel so in this case I have 2 pi K + + align:start position:0% +parallel so in this case I have 2 pi K + + + align:start position:0% +parallel so in this case I have 2 pi K +parallel DK parallel and that's the dkx + + align:start position:0% +parallel DK parallel and that's the dkx + + + align:start position:0% +parallel DK parallel and that's the dkx +dky and then I have 2 pi squar that's + + align:start position:0% +dky and then I have 2 pi squar that's + + + align:start position:0% +dky and then I have 2 pi squar that's +here 2 pi Square then I have another two + + align:start position:0% +here 2 pi Square then I have another two + + + align:start position:0% +here 2 pi Square then I have another two +summation and + + align:start position:0% + + + + align:start position:0% + +F right + + align:start position:0% +F right + + + align:start position:0% +F right +say I'm not jumping into dens of state + + align:start position:0% +say I'm not jumping into dens of state + + + align:start position:0% +say I'm not jumping into dens of state +I'm deriving dens States I'm comfortable + + align:start position:0% +I'm deriving dens States I'm comfortable + + + align:start position:0% +I'm deriving dens States I'm comfortable +doing that just converting the the + + align:start position:0% +doing that just converting the the + + + align:start position:0% +doing that just converting the the +concept just converting my summation + + align:start position:0% +concept just converting my summation + + + align:start position:0% +concept just converting my summation +into + + align:start position:0% +into + + + align:start position:0% +into +integration and uh uh what I can do + + align:start position:0% +integration and uh uh what I can do + + + align:start position:0% +integration and uh uh what I can do +right if I my f is energy so I can write + + align:start position:0% +right if I my f is energy so I can write + + + align:start position:0% +right if I my f is energy so I can write +my K parallel also in terms of + + align:start position:0% +my K parallel also in terms of + + + align:start position:0% +my K parallel also in terms of +energy right so now let go back to the + + align:start position:0% +energy right so now let go back to the + + + align:start position:0% +energy right so now let go back to the +dispersion let's say this is a this let + + align:start position:0% +dispersion let's say this is a this let + + + align:start position:0% +dispersion let's say this is a this let +me make a notation this is my n right + + align:start position:0% +me make a notation this is my n right + + + align:start position:0% +me make a notation this is my n right +that's the sub levels of quanti in Z + + align:start position:0% +that's the sub levels of quanti in Z + + + align:start position:0% +that's the sub levels of quanti in Z +Direction and this is my K + + align:start position:0% +Direction and this is my K + + + align:start position:0% +Direction and this is my K +parallel Square so my I can write this + + align:start position:0% +parallel Square so my I can write this + + + align:start position:0% +parallel Square so my I can write this +uh my K parallel square equals uh 2 + + align:start position:0% +uh my K parallel square equals uh 2 + + + align:start position:0% +uh my K parallel square equals uh 2 +m star H bar square e Min + + align:start position:0% + + + + align:start position:0% + +n + + align:start position:0% +n + + + align:start position:0% +n +right so I have really you can say here + + align:start position:0% +right so I have really you can say here + + + align:start position:0% +right so I have really you can say here +I need to convert if I want to write + + align:start position:0% +I need to convert if I want to write + + + align:start position:0% +I need to convert if I want to write +into in terms of De I need to convert + + align:start position:0% +into in terms of De I need to convert + + + align:start position:0% +into in terms of De I need to convert +this K parallel into energy and I need + + align:start position:0% +this K parallel into energy and I need + + + align:start position:0% +this K parallel into energy and I need +to DK parallel + + align:start position:0% + + + + align:start position:0% + +de okay so if you do your math if you go + + align:start position:0% +de okay so if you do your math if you go + + + align:start position:0% +de okay so if you do your math if you go +to look at what we have + + align:start position:0% + + + + align:start position:0% + +there what I have + + align:start position:0% +there what I have + + + align:start position:0% +there what I have +is uh so this is a 2 pi cancel one and + + align:start position:0% +is uh so this is a 2 pi cancel one and + + + align:start position:0% +is uh so this is a 2 pi cancel one and +two canel one I have another + + align:start position:0% +two canel one I have another + + + align:start position:0% +two canel one I have another +PI right so I + + align:start position:0% +PI right so I + + + align:start position:0% +PI right so I +have um + + align:start position:0% +have um + + + align:start position:0% +have um +integration 1/ pi and sigma whatever n f + + align:start position:0% +integration 1/ pi and sigma whatever n f + + + align:start position:0% +integration 1/ pi and sigma whatever n f +and now I need to write uh here K + + align:start position:0% +and now I need to write uh here K + + + align:start position:0% +and now I need to write uh here K +parallel in fact if I put this in I do + + align:start position:0% +parallel in fact if I put this in I do + + + align:start position:0% +parallel in fact if I put this in I do +the DK Square parallel Square because DK + + align:start position:0% +the DK Square parallel Square because DK + + + align:start position:0% +the DK Square parallel Square because DK +parallel Square I have the here right so + + align:start position:0% +parallel Square I have the here right so + + + align:start position:0% +parallel Square I have the here right so +I have a DK parallel squar that means I + + align:start position:0% +I have a DK parallel squar that means I + + + align:start position:0% +I have a DK parallel squar that means I +have 1 12 I have 2 m bar star and h² and + + align:start position:0% +have 1 12 I have 2 m bar star and h² and + + + align:start position:0% +have 1 12 I have 2 m bar star and h² and +D I'm not sure whether you're following + + align:start position:0% +D I'm not sure whether you're following + + + align:start position:0% +D I'm not sure whether you're following +my conversion I'm writing + + align:start position:0% +my conversion I'm writing + + + align:start position:0% +my conversion I'm writing +this into e k parallel D par based on + + align:start position:0% +this into e k parallel D par based on + + + align:start position:0% +this into e k parallel D par based on +what I have + + align:start position:0% +what I have + + + align:start position:0% +what I have +here and of course uh I have a summation + + align:start position:0% +here and of course uh I have a summation + + + align:start position:0% +here and of course uh I have a summation +n that means when + + align:start position:0% +n that means when + + + align:start position:0% +n that means when +e e has to be larger than n right + + align:start position:0% +e e has to be larger than n right + + + align:start position:0% +e e has to be larger than n right +otherwise this is a uh say I I say you + + align:start position:0% +otherwise this is a uh say I I say you + + + align:start position:0% +otherwise this is a uh say I I say you +can say if I do if it's e is less than n + + align:start position:0% +can say if I do if it's e is less than n + + + align:start position:0% +can say if I do if it's e is less than n +my K parallel will be + + align:start position:0% +my K parallel will be + + + align:start position:0% +my K parallel will be +imagining okay so what I have here all + + align:start position:0% +imagining okay so what I have here all + + + align:start position:0% +imagining okay so what I have here all +this BL Lot F F is the one that I want + + align:start position:0% +this BL Lot F F is the one that I want + + + align:start position:0% +this BL Lot F F is the one that I want +to integrate my density of + + align:start position:0% +to integrate my density of + + + align:start position:0% +to integrate my density of +states is this cancel e n and M + + align:start position:0% +states is this cancel e n and M + + + align:start position:0% +states is this cancel e n and M +star and + + align:start position:0% +star and + + + align:start position:0% +star and +h² and I have another + + align:start position:0% +h² and I have another + + + align:start position:0% +h² and I have another +pi and that's my then substate + + align:start position:0% + + + + align:start position:0% + +okay it's a step function n = 1 and + + align:start position:0% +okay it's a step function n = 1 and + + + align:start position:0% +okay it's a step function n = 1 and +equal 2 you add another one and equals + + align:start position:0% +equal 2 you add another one and equals + + + align:start position:0% +equal 2 you add another one and equals +three you add another + + align:start position:0% +three you add another + + + align:start position:0% +three you add another +one right so what I have here is if I + + align:start position:0% +one right so what I have here is if I + + + align:start position:0% +one right so what I have here is if I +draw this is my e and uh say uh I + + align:start position:0% + + + + align:start position:0% + +have and this is this is my uh e 1 E2 + + align:start position:0% +have and this is this is my uh e 1 E2 + + + align:start position:0% +have and this is this is my uh e 1 E2 +that's the quantization energy level E3 + + align:start position:0% +that's the quantization energy level E3 + + + align:start position:0% +that's the quantization energy level E3 +is Step + + align:start position:0% +is Step + + + align:start position:0% +is Step +function and before we draw the electron + + align:start position:0% +function and before we draw the electron + + + align:start position:0% +function and before we draw the electron +you go check your loads this is a + + align:start position:0% +you go check your loads this is a + + + align:start position:0% +you go check your loads this is a +parabola right this is like a e + + align:start position:0% +parabola right this is like a e + + + align:start position:0% +parabola right this is like a e +say that's the two that's a + + align:start position:0% +say that's the two that's a + + + align:start position:0% +say that's the two that's a +3D this is + + align:start position:0% +3D this is + + + align:start position:0% +3D this is +2D so you see now that there difference + + align:start position:0% +2D so you see now that there difference + + + align:start position:0% +2D so you see now that there difference +in this sub States and once you go to + + align:start position:0% +in this sub States and once you go to + + + align:start position:0% +in this sub States and once you go to +Quan mode you got a more sharp features + + align:start position:0% +Quan mode you got a more sharp features + + + align:start position:0% +Quan mode you got a more sharp features +right step function and you go to wire + + align:start position:0% +right step function and you go to wire + + + align:start position:0% +right step function and you go to wire +you got actually some Delta function the + + align:start position:0% +you got actually some Delta function the + + + align:start position:0% +you got actually some Delta function the +dots you got Delta function it's this + + align:start position:0% +dots you got Delta function it's this + + + align:start position:0% +dots you got Delta function it's this +kind of step and Delta or line that give + + align:start position:0% +kind of step and Delta or line that give + + + align:start position:0% +kind of step and Delta or line that give +you some very pecul characteristics for + + align:start position:0% +you some very pecul characteristics for + + + align:start position:0% +you some very pecul characteristics for +the quantum + + align:start position:0% + + + + align:start position:0% + +systems + + align:start position:0% +systems + + + align:start position:0% +systems +okay any + + align:start position:0% +okay any + + + align:start position:0% +okay any +questions it's + + align:start position:0% +questions it's + + + align:start position:0% +questions it's +math okay it's a + + align:start position:0% +math okay it's a + + + align:start position:0% +math okay it's a +counting now no no complicated physics + + align:start position:0% +counting now no no complicated physics + + + align:start position:0% +counting now no no complicated physics +yes your sum your n is restricted right + + align:start position:0% +yes your sum your n is restricted right + + + align:start position:0% +yes your sum your n is restricted right +so you have uh yeah so the the the right + + align:start position:0% +so you have uh yeah so the the the right + + + align:start position:0% +so you have uh yeah so the the the right +way to write it is I write a heavyside + + align:start position:0% +way to write it is I write a heavyside + + + align:start position:0% +way to write it is I write a heavyside +function so heite is a step + + align:start position:0% +function so heite is a step + + + align:start position:0% +function so heite is a step +function + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +okay + + align:start position:0% +okay + + + align:start position:0% +okay +uh this so we spend uh most of today's + + align:start position:0% +uh this so we spend uh most of today's + + + align:start position:0% +uh this so we spend uh most of today's +lecture in doing the counting and say + + align:start position:0% +lecture in doing the counting and say + + + align:start position:0% +lecture in doing the counting and say +how I really is converting summation + + align:start position:0% +how I really is converting summation + + + align:start position:0% +how I really is converting summation +into + + align:start position:0% +into + + + align:start position:0% +into +integration and uh if the function + + align:start position:0% +integration and uh if the function + + + align:start position:0% +integration and uh if the function +doesn't change much over the summation I + + align:start position:0% +doesn't change much over the summation I + + + align:start position:0% +doesn't change much over the summation I +can convert in the quantum's case in the + + align:start position:0% +can convert in the quantum's case in the + + + align:start position:0% +can convert in the quantum's case in the +direction + + align:start position:0% +direction + + + align:start position:0% +direction +quantization that conversion is usually + + align:start position:0% +quantization that conversion is usually + + + align:start position:0% +quantization that conversion is usually +have to be careful you you probably + + align:start position:0% +have to be careful you you probably + + + align:start position:0% +have to be careful you you probably +cannot do that conversion because there + + align:start position:0% +cannot do that conversion because there + + + align:start position:0% +cannot do that conversion because there +is a large change of that function in + + align:start position:0% +is a large change of that function in + + + align:start position:0% +is a large change of that function in +the uh summation Direction + + align:start position:0% +the uh summation Direction + + + align:start position:0% +the uh summation Direction +and uh uh What uh uh we go in next is do + + align:start position:0% +and uh uh What uh uh we go in next is do + + + align:start position:0% +and uh uh What uh uh we go in next is do +this + + align:start position:0% +this + + + align:start position:0% +this +F okay in particular we're doing a + + align:start position:0% +F okay in particular we're doing a + + + align:start position:0% +F okay in particular we're doing a +system at certain + + align:start position:0% +system at certain + + + align:start position:0% +system at certain +temperature and uh what's the the + + align:start position:0% +temperature and uh what's the the + + + align:start position:0% +temperature and uh what's the the +answering the question at the one one + + align:start position:0% +answering the question at the one one + + + align:start position:0% +answering the question at the one one +Quantum State each Quantum state for + + align:start position:0% +Quantum State each Quantum state for + + + align:start position:0% +Quantum State each Quantum state for +example what's the average L of electron + + align:start position:0% +example what's the average L of electron + + + align:start position:0% +example what's the average L of electron +because it could be zero and one but at + + align:start position:0% +because it could be zero and one but at + + + align:start position:0% +because it could be zero and one but at +certain temperature there's statistical + + align:start position:0% +certain temperature there's statistical + + + align:start position:0% +certain temperature there's statistical +average what's that L this same for Fon + + align:start position:0% +average what's that L this same for Fon + + + align:start position:0% +average what's that L this same for Fon +right I can have 0 one infinite then + + align:start position:0% +right I can have 0 one infinite then + + + align:start position:0% +right I can have 0 one infinite then +what's the average L of Fon for each + + align:start position:0% +what's the average L of Fon for each + + + align:start position:0% +what's the average L of Fon for each +Quantum State now I know how to how I + + align:start position:0% +Quantum State now I know how to how I + + + align:start position:0% +Quantum State now I know how to how I +can count Quantum state right how many + + align:start position:0% +can count Quantum state right how many + + + align:start position:0% +can count Quantum state right how many +Quantum State I have what I want to say + + align:start position:0% +Quantum State I have what I want to say + + + align:start position:0% +Quantum State I have what I want to say +next is at each Quant State how many + + align:start position:0% +next is at each Quant State how many + + + align:start position:0% +next is at each Quant State how many +electrons how many Fons given a certain + + align:start position:0% +electrons how many Fons given a certain + + + align:start position:0% +electrons how many Fons given a certain +temperature now I'm going to get into + + align:start position:0% +temperature now I'm going to get into + + + align:start position:0% +temperature now I'm going to get into +Thal system + + align:start position:0% +Thal system + + + align:start position:0% +Thal system +right and how much energy you have + + align:start position:0% +right and how much energy you have + + + align:start position:0% +right and how much energy you have +so uh let me uh give a very uh say a + + align:start position:0% +so uh let me uh give a very uh say a + + + align:start position:0% +so uh let me uh give a very uh say a +beginning of + + align:start position:0% +beginning of + + + align:start position:0% +beginning of +that and uh in fact if you + + align:start position:0% + + + + align:start position:0% + +recall we did in the first chapter we + + align:start position:0% +recall we did in the first chapter we + + + align:start position:0% +recall we did in the first chapter we +give you the bman factor right so uh + + align:start position:0% +give you the bman factor right so uh + + + align:start position:0% +give you the bman factor right so uh +this is + + align:start position:0% +this is + + + align:start position:0% +this is +my Quantum statistics + + align:start position:0% + + + + align:start position:0% + +and uh uh in uh the first uh uh chapter + + align:start position:0% +and uh uh in uh the first uh uh chapter + + + align:start position:0% +and uh uh in uh the first uh uh chapter +beginning we say the bman factor gives + + align:start position:0% +beginning we say the bman factor gives + + + align:start position:0% +beginning we say the bman factor gives +you the + + align:start position:0% +you the + + + align:start position:0% +you the +probability of a + + align:start position:0% +probability of a + + + align:start position:0% +probability of a +particle we were not we're see not + + align:start position:0% +particle we were not we're see not + + + align:start position:0% +particle we were not we're see not +discussing whether it's Quantum or + + align:start position:0% +discussing whether it's Quantum or + + + align:start position:0% +discussing whether it's Quantum or +classical probability of particle having + + align:start position:0% +classical probability of particle having + + + align:start position:0% +classical probability of particle having +certain energy at certain + + align:start position:0% +certain energy at certain + + + align:start position:0% +certain energy at certain +temperature is a normalization factor + + align:start position:0% +temperature is a normalization factor + + + align:start position:0% +temperature is a normalization factor +minus say exponential e + + align:start position:0% +minus say exponential e + + + align:start position:0% +minus say exponential e +KBT I said take it this is the uh uh the + + align:start position:0% +KBT I said take it this is the uh uh the + + + align:start position:0% +KBT I said take it this is the uh uh the +Borman Factor + + align:start position:0% + + + + align:start position:0% + +right You' seen many many say examples + + align:start position:0% +right You' seen many many say examples + + + align:start position:0% +right You' seen many many say examples +of this bardman Factor say the energy + + align:start position:0% +of this bardman Factor say the energy + + + align:start position:0% +of this bardman Factor say the energy +barriers arenus no or this related to + + align:start position:0% +barriers arenus no or this related to + + + align:start position:0% +barriers arenus no or this related to +the bman factor and next lecture I hope + + align:start position:0% +the bman factor and next lecture I hope + + + align:start position:0% +the bman factor and next lecture I hope +I give you a little bit r of this okay + + align:start position:0% +I give you a little bit r of this okay + + + align:start position:0% +I give you a little bit r of this okay +there is a beautiful uh statistical + + align:start position:0% +there is a beautiful uh statistical + + + align:start position:0% +there is a beautiful uh statistical +framework to do + + align:start position:0% +framework to do + + + align:start position:0% +framework to do +that and uh so we use this and then we + + align:start position:0% +that and uh so we use this and then we + + + align:start position:0% +that and uh so we use this and then we +went to the Maxwell + + align:start position:0% +went to the Maxwell + + + align:start position:0% +went to the Maxwell +distribution right if I have particle + + align:start position:0% +distribution right if I have particle + + + align:start position:0% +distribution right if I have particle +that has + + align:start position:0% +that has + + + align:start position:0% +that has +energy 12 m v x² + V y² + VZ s + + align:start position:0% +energy 12 m v x² + V y² + VZ s + + + align:start position:0% +energy 12 m v x² + V y² + VZ s +right I say okay I normalize this I put + + align:start position:0% +right I say okay I normalize this I put + + + align:start position:0% +right I say okay I normalize this I put +it in here and the a particle has the + + align:start position:0% +it in here and the a particle has the + + + align:start position:0% +it in here and the a particle has the +probability between minus infinite to + + align:start position:0% +probability between minus infinite to + + + align:start position:0% +probability between minus infinite to +plus infinite is one so with that I find + + align:start position:0% +plus infinite is one so with that I find + + + align:start position:0% +plus infinite is one so with that I find +that a normalization factor that's how I + + align:start position:0% +that a normalization factor that's how I + + + align:start position:0% +that a normalization factor that's how I +get the max wheel + + align:start position:0% +get the max wheel + + + align:start position:0% +get the max wheel +distribution right so you see in that + + align:start position:0% +distribution right so you see in that + + + align:start position:0% +distribution right so you see in that +process I did not consider the + + align:start position:0% +process I did not consider the + + + align:start position:0% +process I did not consider the +discontinuity of the Velocity any value + + align:start position:0% +discontinuity of the Velocity any value + + + align:start position:0% +discontinuity of the Velocity any value +between M infinite to plus + + align:start position:0% +between M infinite to plus + + + align:start position:0% +between M infinite to plus +infinite now I'm going to do a little + + align:start position:0% +infinite now I'm going to do a little + + + align:start position:0% +infinite now I'm going to do a little +bit say discontinuous + + align:start position:0% +bit say discontinuous + + + align:start position:0% +bit say discontinuous +right I'm going to ask for example if I + + align:start position:0% +right I'm going to ask for example if I + + + align:start position:0% +right I'm going to ask for example if I +have a Quantum state electron is in in + + align:start position:0% +have a Quantum state electron is in in + + + align:start position:0% +have a Quantum state electron is in in +thermal equilibrium with + + align:start position:0% +thermal equilibrium with + + + align:start position:0% +thermal equilibrium with +surrounding at the temperature + + align:start position:0% +surrounding at the temperature + + + align:start position:0% +surrounding at the temperature +T right and + + align:start position:0% +T right and + + + align:start position:0% +T right and +electron say uh uh say what's the + + align:start position:0% +electron say uh uh say what's the + + + align:start position:0% +electron say uh uh say what's the +average so this is now I'm looking at + + align:start position:0% +average so this is now I'm looking at + + + align:start position:0% +average so this is now I'm looking at +the one Quantum state right it's in + + align:start position:0% +the one Quantum state right it's in + + + align:start position:0% +the one Quantum state right it's in +seral equilibrium with surrounding I'm + + align:start position:0% +seral equilibrium with surrounding I'm + + + align:start position:0% +seral equilibrium with surrounding I'm +asking question what's the probability + + align:start position:0% +asking question what's the probability + + + align:start position:0% +asking question what's the probability +of this Quantum State how many electrons + + align:start position:0% +of this Quantum State how many electrons + + + align:start position:0% +of this Quantum State how many electrons +has right so that's the question I'm + + align:start position:0% +has right so that's the question I'm + + + align:start position:0% +has right so that's the question I'm +asking and uh now the difference of that + + align:start position:0% +asking and uh now the difference of that + + + align:start position:0% +asking and uh now the difference of that +question there are two difference + + align:start position:0% +question there are two difference + + + align:start position:0% +question there are two difference +compared to here one is that electron in + + align:start position:0% +compared to here one is that electron in + + + align:start position:0% +compared to here one is that electron in +that Quant state that you can go the + + align:start position:0% +that Quant state that you can go the + + + align:start position:0% +that Quant state that you can go the +electron can be in that Quant state or + + align:start position:0% +electron can be in that Quant state or + + + align:start position:0% +electron can be in that Quant state or +jump out to the surrounding so I have + + align:start position:0% +jump out to the surrounding so I have + + + align:start position:0% +jump out to the surrounding so I have +mass transfer a charge transfer whatever + + align:start position:0% +mass transfer a charge transfer whatever + + + align:start position:0% +mass transfer a charge transfer whatever +right it's open + + align:start position:0% +right it's open + + + align:start position:0% +right it's open +system so that's one second is the that + + align:start position:0% +system so that's one second is the that + + + align:start position:0% +system so that's one second is the that +electron that Quant State can only have + + align:start position:0% +electron that Quant State can only have + + + align:start position:0% +electron that Quant State can only have +zero and one + + align:start position:0% +zero and one + + + align:start position:0% +zero and one +discr okay so when I have here Boardman + + align:start position:0% +discr okay so when I have here Boardman + + + align:start position:0% +discr okay so when I have here Boardman +factor is for close system at constant + + align:start position:0% +factor is for close system at constant + + + align:start position:0% +factor is for close system at constant +temperature and when I deal with a open + + align:start position:0% +temperature and when I deal with a open + + + align:start position:0% +temperature and when I deal with a open +system at a constant temperature I have + + align:start position:0% +system at a constant temperature I have + + + align:start position:0% +system at a constant temperature I have +to modify this so I'm going to give you + + align:start position:0% +to modify this so I'm going to give you + + + align:start position:0% +to modify this so I'm going to give you +again just wait for next lecture uh see + + align:start position:0% +again just wait for next lecture uh see + + + align:start position:0% +again just wait for next lecture uh see +the Gibs Factor + + align:start position:0% + + + + align:start position:0% + +and GES factor for open system and the + + align:start position:0% +and GES factor for open system and the + + + align:start position:0% +and GES factor for open system and the +probability + + align:start position:0% +probability + + + align:start position:0% +probability +of a system open system has certain + + align:start position:0% +of a system open system has certain + + + align:start position:0% +of a system open system has certain +energy and certain number of particle as + + align:start position:0% +energy and certain number of particle as + + + align:start position:0% +energy and certain number of particle as +at the temperature T is uh uh a again + + align:start position:0% +at the temperature T is uh uh a again + + + align:start position:0% +at the temperature T is uh uh a again +normalization Min the energy of the + + align:start position:0% +normalization Min the energy of the + + + align:start position:0% +normalization Min the energy of the +system Min the uh number particle times + + align:start position:0% +system Min the uh number particle times + + + align:start position:0% +system Min the uh number particle times +this constant mu and divide by + + align:start position:0% +this constant mu and divide by + + + align:start position:0% +this constant mu and divide by +KBT so now I add this mu which is the + + align:start position:0% +KBT so now I add this mu which is the + + + align:start position:0% +KBT so now I add this mu which is the +chemical potential that's say how much + + align:start position:0% +chemical potential that's say how much + + + align:start position:0% +chemical potential that's say how much +energy you need to take out or place a + + align:start position:0% +energy you need to take out or place a + + + align:start position:0% +energy you need to take out or place a +particle into the system that's chemical + + align:start position:0% +particle into the system that's chemical + + + align:start position:0% +particle into the system that's chemical +potential okay so mu is the chemical + + align:start position:0% +potential okay so mu is the chemical + + + align:start position:0% +potential okay so mu is the chemical +potential + + align:start position:0% + + + + align:start position:0% + +and that's the same CRA potential is uh + + align:start position:0% +and that's the same CRA potential is uh + + + align:start position:0% +and that's the same CRA potential is uh +essentially it gives free + + align:start position:0% +essentially it gives free + + + align:start position:0% +essentially it gives free +energy and uh uh it's a it's it doesn't + + align:start position:0% +energy and uh uh it's a it's it doesn't + + + align:start position:0% +energy and uh uh it's a it's it doesn't +include the the entropy part and uh + + align:start position:0% +include the the entropy part and uh + + + align:start position:0% +include the the entropy part and uh +gives free energy difference gives you + + align:start position:0% +gives free energy difference gives you + + + align:start position:0% +gives free energy difference gives you +how much work you can get out of the + + align:start position:0% +how much work you can get out of the + + + align:start position:0% +how much work you can get out of the +system okay so + + align:start position:0% +system okay so + + + align:start position:0% +system okay so +with that I'm considering one isolated + + align:start position:0% +with that I'm considering one isolated + + + align:start position:0% +with that I'm considering one isolated +electron uh Quantum + + align:start position:0% + + + + align:start position:0% + +State this is the easiest so I have one + + align:start position:0% +State this is the easiest so I have one + + + align:start position:0% +State this is the easiest so I have one +Quantum state of + + align:start position:0% +Quantum state of + + + align:start position:0% +Quantum state of +electron right this is the solution you + + align:start position:0% +electron right this is the solution you + + + align:start position:0% +electron right this is the solution you +had before in Quantum from either for + + align:start position:0% +had before in Quantum from either for + + + align:start position:0% +had before in Quantum from either for +solid or for uh molecule or for atom + + align:start position:0% +solid or for uh molecule or for atom + + + align:start position:0% +solid or for uh molecule or for atom +right you have this solution of quantum + + align:start position:0% +right you have this solution of quantum + + + align:start position:0% +right you have this solution of quantum +State this is what we we've been doing + + align:start position:0% +State this is what we we've been doing + + + align:start position:0% +State this is what we we've been doing +the question is whether there is a + + align:start position:0% +the question is whether there is a + + + align:start position:0% +the question is whether there is a +electron in that Quantum state or not so + + align:start position:0% +electron in that Quantum state or not so + + + align:start position:0% +electron in that Quantum state or not so +what's the probability is zero or + + align:start position:0% +what's the probability is zero or + + + align:start position:0% +what's the probability is zero or +one right say this are the two states + + align:start position:0% +one right say this are the two states + + + align:start position:0% +one right say this are the two states +when n equals z or one when n equals z + + align:start position:0% +when n equals z or one when n equals z + + + align:start position:0% +when n equals z or one when n equals z +even though you have that Quantum state + + align:start position:0% +even though you have that Quantum state + + + align:start position:0% +even though you have that Quantum state +that state doesn't have real electron + + align:start position:0% +that state doesn't have real electron + + + align:start position:0% +that state doesn't have real electron +there doesn't have + + align:start position:0% +there doesn't have + + + align:start position:0% +there doesn't have +energy so the energy when this is zero + + align:start position:0% +energy so the energy when this is zero + + + align:start position:0% +energy so the energy when this is zero +this is + + align:start position:0% +this is + + + align:start position:0% +this is +zero and when you have one particle that + + align:start position:0% +zero and when you have one particle that + + + align:start position:0% +zero and when you have one particle that +energy that state has energy EI right so + + align:start position:0% +energy that state has energy EI right so + + + align:start position:0% +energy that state has energy EI right so +eii now I use + + align:start position:0% +eii now I use + + + align:start position:0% +eii now I use +this to possibility I do my + + align:start position:0% +this to possibility I do my + + + align:start position:0% +this to possibility I do my +normalization factor for the Gibs Factor + + align:start position:0% +normalization factor for the Gibs Factor + + + align:start position:0% +normalization factor for the Gibs Factor +so add up it has to be has to be either + + align:start position:0% +so add up it has to be has to be either + + + align:start position:0% +so add up it has to be has to be either +zero or one + + align:start position:0% +zero or one + + + align:start position:0% +zero or one +right the add up has to be + + align:start position:0% +right the add up has to be + + + align:start position:0% +right the add up has to be +one so when it's zero + + align:start position:0% +one so when it's zero + + + align:start position:0% +one so when it's zero +p 0 0 t plus P here is + + align:start position:0% +p 0 0 t plus P here is + + + align:start position:0% +p 0 0 t plus P here is +EI one t that has to be one so the first + + align:start position:0% +EI one t that has to be one so the first + + + align:start position:0% +EI one t that has to be one so the first +when z z that's just a the second when + + align:start position:0% +when z z that's just a the second when + + + align:start position:0% +when z z that's just a the second when +uh EI so I have minus + + align:start position:0% +uh EI so I have minus + + + align:start position:0% +uh EI so I have minus +EI mu * n is just + + align:start position:0% +EI mu * n is just + + + align:start position:0% +EI mu * n is just +mu + + align:start position:0% +mu + + + align:start position:0% +mu +KBT equals 1 so this gives me a + + align:start position:0% +KBT equals 1 so this gives me a + + + align:start position:0% +KBT equals 1 so this gives me a +equals + + align:start position:0% +equals + + + align:start position:0% +equals +exponential Mass EI mu + + align:start position:0% +exponential Mass EI mu + + + align:start position:0% +exponential Mass EI mu +KBT + + + align:start position:0% +KBT + + + + align:start position:0% +KBT + +one that's my normalization factor + + align:start position:0% +one that's my normalization factor + + + align:start position:0% +one that's my normalization factor +a + + align:start position:0% +a + + + align:start position:0% +a +right now my average L of particle F + + align:start position:0% +right now my average L of particle F + + + align:start position:0% +right now my average L of particle F +average L which is the average L of + + align:start position:0% +average L which is the average L of + + + align:start position:0% +average L which is the average L of +n right once I have distribution + + align:start position:0% +n right once I have distribution + + + align:start position:0% +n right once I have distribution +probability + + align:start position:0% +probability + + + align:start position:0% +probability +I + + align:start position:0% +I + + + align:start position:0% +I +can find the average any quantity + + align:start position:0% +can find the average any quantity + + + align:start position:0% +can find the average any quantity +average energy average L particle + + align:start position:0% +average energy average L particle + + + align:start position:0% +average energy average L particle +whatever average you want right so that + + align:start position:0% +whatever average you want right so that + + + align:start position:0% +whatever average you want right so that +should be zero because Z times this p 0 + + align:start position:0% +should be zero because Z times this p 0 + + + align:start position:0% +should be zero because Z times this p 0 +0 t plus uh one I one particle time p uh + + align:start position:0% +0 t plus uh one I one particle time p uh + + + align:start position:0% +0 t plus uh one I one particle time p uh +EI 1 T so that's my average L of + + align:start position:0% +EI 1 T so that's my average L of + + + align:start position:0% +EI 1 T so that's my average L of +particle + + align:start position:0% +particle + + + align:start position:0% +particle +right because this is the + + align:start position:0% +right because this is the + + + align:start position:0% +right because this is the +probability when a EI one fully + + align:start position:0% +probability when a EI one fully + + + align:start position:0% +probability when a EI one fully +empty and uh you go you know your a you + + align:start position:0% +empty and uh you go you know your a you + + + align:start position:0% +empty and uh you go you know your a you +know your uh p f uh a times this EI mu n + + align:start position:0% +know your uh p f uh a times this EI mu n + + + align:start position:0% +know your uh p f uh a times this EI mu n +so you can see this one and this one is + + align:start position:0% +so you can see this one and this one is + + + align:start position:0% +so you can see this one and this one is +the + + align:start position:0% +the + + + align:start position:0% +the +same + + align:start position:0% +same + + + align:start position:0% +same +right in the numerator I have this one + + align:start position:0% +right in the numerator I have this one + + + align:start position:0% +right in the numerator I have this one +in the gometer I have this one but I + + align:start position:0% +in the gometer I have this one but I + + + align:start position:0% +in the gometer I have this one but I +have plus Vector one + + align:start position:0% +have plus Vector one + + + align:start position:0% +have plus Vector one +right so I divide this so I can write + + align:start position:0% +right so I divide this so I can write + + + align:start position:0% +right so I divide this so I can write +the simpler and you will see now what I + + align:start position:0% +the simpler and you will see now what I + + + align:start position:0% +the simpler and you will see now what I +have is EI Mass mu + + align:start position:0% +have is EI Mass mu + + + align:start position:0% +have is EI Mass mu +KBT + one and this is the + + align:start position:0% +KBT + one and this is the + + + align:start position:0% +KBT + one and this is the +famor forid rock distribution + + align:start position:0% + + + + align:start position:0% + +okay so in in three + + align:start position:0% +okay so in in three + + + align:start position:0% +okay so in in three +steps right you get the if you take that + + align:start position:0% +steps right you get the if you take that + + + align:start position:0% +steps right you get the if you take that +energy quantization probability + + align:start position:0% +energy quantization probability + + + align:start position:0% +energy quantization probability +normalization you got from a + + align:start position:0% +normalization you got from a + + + align:start position:0% +normalization you got from a +drug and the next lecture we'll + + align:start position:0% +drug and the next lecture we'll + + + align:start position:0% +drug and the next lecture we'll +get uh we'll go few more step to get the + + align:start position:0% +get uh we'll go few more step to get the + + + align:start position:0% +get uh we'll go few more step to get the +both Einstein distribution for Fons this + + align:start position:0% +both Einstein distribution for Fons this + + + align:start position:0% +both Einstein distribution for Fons this +are for electrons \ No newline at end of file diff --git a/JIjr9CmN5eI.txt b/JIjr9CmN5eI.txt new file mode 100644 index 0000000000000000000000000000000000000000..ff8030056ef20d8cd8e419baa3dcf47aa249564d --- /dev/null +++ b/JIjr9CmN5eI.txt @@ -0,0 +1,675 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit MIT opencourseware + + align:start position:0% +of MIT courses visit MIT opencourseware + + + align:start position:0% +of MIT courses visit MIT opencourseware +at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu then I'll go and pick it up + + align:start position:0% +ocw.mit.edu then I'll go and pick it up + + + align:start position:0% +ocw.mit.edu then I'll go and pick it up +from the side like this and just press + + align:start position:0% +from the side like this and just press + + + align:start position:0% +from the side like this and just press +break it break it and sometimes it's + + align:start position:0% +break it break it and sometimes it's + + + align:start position:0% +break it break it and sometimes it's +it's a little inconsistent because + + align:start position:0% +it's a little inconsistent because + + + align:start position:0% +it's a little inconsistent because +depending on the waer and how well it + + align:start position:0% +depending on the waer and how well it + + + align:start position:0% +depending on the waer and how well it +released and how well cut some of them + + align:start position:0% +released and how well cut some of them + + + align:start position:0% +released and how well cut some of them +have real thin tabs that break you know + + align:start position:0% +have real thin tabs that break you know + + + align:start position:0% +have real thin tabs that break you know +instantly and some you have to really oh + + align:start position:0% +instantly and some you have to really oh + + + align:start position:0% +instantly and some you have to really oh +these are theong + + align:start position:0% + + + + align:start position:0% + +on yeah that that that works sometimes + + align:start position:0% +on yeah that that that works sometimes + + + align:start position:0% +on yeah that that that works sometimes +but + + align:start position:0% + + + + align:start position:0% + +find it helpful to put it back down and + + align:start position:0% +find it helpful to put it back down and + + + align:start position:0% +find it helpful to put it back down and +then grab it by the edges oh + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +sorry am I facing the right way yes + + align:start position:0% + + + + align:start position:0% + +yes yeah that looks pretty + + align:start position:0% + + + + align:start position:0% + +good good + + align:start position:0% + + + + align:start position:0% + +enough take a + + align:start position:0% + + + + align:start position:0% + +look mhm that looks + + align:start position:0% + + + + align:start position:0% + +good seting it back yeah sometimes I + + align:start position:0% +good seting it back yeah sometimes I + + + align:start position:0% +good seting it back yeah sometimes I +just check to make sure it's not back in + + align:start position:0% +just check to make sure it's not back in + + + align:start position:0% +just check to make sure it's not back in +there it helps with positioning the + + align:start position:0% +there it helps with positioning the + + + align:start position:0% +there it helps with positioning the +laser into cuz sometimes it's out + + align:start position:0% +laser into cuz sometimes it's out + + + align:start position:0% +laser into cuz sometimes it's out +farther and the angle is a little + + align:start position:0% + + + + align:start position:0% + +different + + align:start position:0% + + + + align:start position:0% + +great + + align:start position:0% +great + + + align:start position:0% +great +yeah to use + + align:start position:0% +yeah to use + + + align:start position:0% +yeah to use +side yeah should be bing up on the side + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +I + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +I'm + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +in trouble with + + align:start position:0% + + + + align:start position:0% + +this how do you like fli it over now + + align:start position:0% +this how do you like fli it over now + + + align:start position:0% +this how do you like fli it over now +what's kind of microscope well I + + align:start position:0% + + + + align:start position:0% + +think yeah + + align:start position:0% + + + + align:start position:0% + +that might be good but I still think I + + align:start position:0% +that might be good but I still think I + + + align:start position:0% +that might be good but I still think I +need to go + + align:start position:0% + + + + align:start position:0% + +down there we go + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +okay it used to be it used to be + + align:start position:0% +okay it used to be it used to be + + + align:start position:0% +okay it used to be it used to be +significantly no when using with vibrate + + align:start position:0% +significantly no when using with vibrate + + + align:start position:0% +significantly no when using with vibrate +but these On's not so bad I you can look + + align:start position:0% +but these On's not so bad I you can look + + + align:start position:0% +but these On's not so bad I you can look +I mean as far as as far as the recording + + align:start position:0% +I mean as far as as far as the recording + + + align:start position:0% +I mean as far as as far as the recording +spectum make a huge + + align:start position:0% +spectum make a huge + + + align:start position:0% +spectum make a huge +difference at yeah you'll be able to see + + align:start position:0% + + + + align:start position:0% + +it s + + align:start position:0% + + + + align:start position:0% + +I don't know if + + align:start position:0% + + + + align:start position:0% + +can just + + align:start position:0% + + + + align:start position:0% + +this one + + align:start position:0% + + + + align:start position:0% + +good can I close sorry can you please + + align:start position:0% +good can I close sorry can you please + + + align:start position:0% +good can I close sorry can you please +close the + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +they can't deliver us here + + align:start position:0% + + + + align:start position:0% + +I thought it + + align:start position:0% + + + + align:start position:0% + +was + + align:start position:0% +was + + + align:start position:0% +was +pretty so now we + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +so I want to + + align:start position:0% +so I want to + + + align:start position:0% +so I want to +be as close to the face + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +I you want to be as + + align:start position:0% +I you want to be as + + + align:start position:0% +I you want to be as +far go as + + align:start position:0% + + + + align:start position:0% + +total + + align:start position:0% + + + + align:start position:0% + +so well I guess that's + + align:start position:0% + + + + align:start position:0% + +just + + align:start position:0% + + + + align:start position:0% + +rightly + + align:start position:0% + + + + align:start position:0% + +NOP we just said one of these Pro late + + align:start position:0% +NOP we just said one of these Pro late + + + align:start position:0% +NOP we just said one of these Pro late +out nights a good + + align:start position:0% + + + + align:start position:0% + +yeah you would have to do it in the + + align:start position:0% +yeah you would have to do it in the + + + align:start position:0% +yeah you would have to do it in the +middle of the air and + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +find + + align:start position:0% +find + + + align:start position:0% +find +on sores are really bad you know like + + align:start position:0% +on sores are really bad you know like + + + align:start position:0% +on sores are really bad you know like +how um the is is broken so very go + + align:start position:0% +how um the is is broken so very go + + + align:start position:0% +how um the is is broken so very go +grab \ No newline at end of file diff --git a/JRgIXyEPnbA.txt b/JRgIXyEPnbA.txt new file mode 100644 index 0000000000000000000000000000000000000000..8e7d8f862f9d9ce7ca9b5ac90082c92e6de51d20 --- /dev/null +++ b/JRgIXyEPnbA.txt @@ -0,0 +1,2747 @@ +The following +content is provided + +under a Creative +Commons license. + +Your support will help MIT +OpenCourseWare continue + +to offer high quality +educational resources for free. + +To make a donation or +view additional materials + +from hundreds of MIT courses, +visit MIT OpenCourseWare + +at ocw.mit.edu. + +PROFESSOR: Everything +make sense? + +Are you guys good with Newton? + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: Yes, really? + +I'm done. + +I'm going home. + +Are you guys good +with Karatsuba? + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: Kara-what? + +[LAUGHTER] + +OK, so who is happy +with Karatsuba? + +Good. + +Who is happy with Newton? + +Wait. + +I need to ask the other ones, +because not enough people-- + +who is not happy with Newton +and wants to look over it? + +Who wants to look +over Karatsuba? + +Oh, so you guy are +paying attention. + +Good. + +OK. + +All right. + +So Newton and Karatsuba. + +Let's start. + +So Karatsuba real +fast, and then we'll + +spend more time having +fun with Newton. + +So suppose we don't +know Karatsuba. + +We want to multiply two numbers. + +What's the method that we +learned in elementary school? + +AUDIENCE: You take the first +digit of the first number, + +and then you multiply +it by the second number. + +And then you take +the second digit + +and multiply it by the second +number, but then you add a 0. + +And so on and so forth. + +PROFESSOR: So I'll +take this digit + +and multiply it with this number +and write the result down here, + +right? + +So whatever this thing happens +to be, 1, 2, 3, 4 times 8, + +write the result. + +Then I take 1, 2, 3, 4 times +7 and add the result here + +and the last digits are 0. + +1, 2, 3, 4 times 6, two 0s. + +1, 2, 3, 4 times 5, three 0s. + +Then I add these up +and I know that I'm + +going to get the right result. + +What's the running +time for this? + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: OK. + +So why is it n squared? + +AUDIENCE: Because you go +through every single thing + +for every digit below. + +PROFESSOR: Yup. + +So I'll have these +partial products here, + +and I have as many +partial products + +as digits in the second number. + +So if I have n digits here, +I have n partial products. + +Each partial product is this +first number here multiplied + +by a digit. + +So if this guy has +n digits, then there + +are n digits everywhere here. + +And this thing will be +2 n insides actually, + +but we're doing asymptotic, +so we don't really + +care about constant factors. + +So in the end, you have +to add up n numbers. + +All of them are order n in size. + +So n times order n squared. + +This is plain old +multiplication. + +Does anyone know why +Karatsuba's better? + +Yes? + +AUDIENCE: You do +three multiplications + +or something like that? + +PROFESSOR: OK. + +So, let's go for +a simple answer. + +AUDIENCE: It's better. + +PROFESSOR: So the simpler +answer is it's faster. + +AUDIENCE: OK. + +PROFESSOR: n, n log 2-- + +AUDIENCE: I said +better, it's faster. + +PROFESSOR: I mean, some +algorithms have the same speed + +but are simpler. + +We like this one +because it's faster. + +It's definitely not simpler. + +So, it has this +running time here. + +Log 2 of 3 is a weird number. + +It's somewhere +between 1.5 and 2. + +So not revolutionary, but +it's better than this guy. + +OK, why do we get to this? + +How do we get to this? + +Does anyone remember +the recurrence for it? + +Yes? + +AUDIENCE: It's 3 times 2-- + +PROFESSOR: You're +not remembering it. + +You're cheating. + +AUDIENCE: No, I'm not. + +[LAUGHTER] + +PROFESSOR: So, let's see +why it looks like this. + +Karatsuba takes 2 numbers that +have n digits, splits both + +of them up into two-- n over 2n, +n over 2, n over 2, n over 2-- + +and then is able to compute the +product of these two numbers + +by only using three +multiplications, and then + +some additions. + +Multiplications are expensive, +additions are cheap. + +So it does three multiplications +that are of the form + +some number of n over +2 digits multiplied + +by some number of +n over or 2 digits. + +And exactly what the +multiplications and what + +the additions are is, it's +interesting to look over it. + +You can look over it, convince +yourself that this is correct. + +Chances are you'll remember for +the exam and forget afterwards. + +Please remember this. + +This is the essence +of Karatsuba. + +And remember Karatsuba, +because if you google this, + +you get the rest. + +So the multiplications +are in the notes. + +I don't think it makes sense +to spend some time on them + +and convince you +that, yeah, there + +are three multiplications +that will get you that. + +Instead, suppose I labeled +these as a, b, c, d. + +If I evaluate the multiplication +as using brute force, + +it's a times n over 2b plus +c-- sorry, a plus-- no, + +this isn't good. + +10 to the power n over 2a plus +b times 10-- assuming the base + +is ten, if it's not, you +replace it-- n over 2 c plus d. + +And you get 10 to the n +times, I think, ac plus 10 + +to the n over 2 times +ad plus bc plus bd. + +The problem with this is +this is a multiplication, + +multiplication, +multiplication, multiplication. + +So this uses four +multiplications + +of size n over 2 to +evaluate the answer one + +multiplication of size n. + +And if I have four +multiplications, + +then the recursion becomes +4t of n over 2 plus o of n. + +So this is t bad of n. + +So if you do this using +the recursion tree, + +you're going to see that-- +yup, I hear whispers. + +n squared. + +So this isn't useful. + +This will give you +insight on how to do it, + +but if you try to +implement it this way, + +you don't get any speed up. + +The insight in Karatsuba +is that the guy figured out + +how to do this with +three multiplications. + +OK, makes sense? + +Is everyone happy +with Karatsuba now? + +So that multiplying by 10 to +the n over 2 is just shifting a? + +PROFESSOR: Yup. + +OK. + +Very good point. + +So this isn't an +actual multiplication. + +If you have your number, say +stored in a python list-- + +so if these are +your digits, then + +in order to multiply +by 10 to the n, + +you append 10 to +the n 0s at the end. + +0, 0, 0, 0, 0. + +So, this is append of 0 n times. + +So this is order n, so it +counts as an addition, not as + +a multiplication. + +So, these are free. + +These are expensive. + +1, 2, 3, 4. + +OK. + +Who's happy with Karatsuba now? + +Let me feel like I did +something useful today. + +AUDIENCE: I have a question. + +PROFESSOR: Yes. + +AUDIENCE: I didn't fully +understand what [INAUDIBLE]. + +PROFESSOR: So, I +have this number + +and I'm splitting +it up into 2 halves. + +The way split up is I say this +is a number of size n over 2, + +and I have to shift +it to the left. + +So n 10 to the power +of n over 2 shifts + +it left by n over two digits. + +And then I add it to b. + +So this in a sense +is just saying + +that this is the left half, +this is the right half. + +AUDIENCE: This is +actually that same number. + +PROFESSOR: Yup. + +It's exactly the same number. + +OK, so who is happy +with Karatsuba now? + +AUDIENCE: Wait, but that's +four multiplications though. + +PROFESSOR: Exactly. + +AUDIENCE: That's not three. + +PROFESSOR: Exactly. + +AUDIENCE: But we said +there were three. + +PROFESSOR: So, I was +saying that this, + +if you;re doing it the brute +force way, you get four, + +and that is slow. + +So what Karatsuba +did is he figured out + +the way to do this with +just three multiplications. + +So it's not these three. + +You have to think +a little bit more. + +But you google it, or you +look at the lecture notes, + +or you think a little +bit, then you find out + +the three multiplications +that do the trick. + +So the difference between +this 4 here and this 3 + +here is important. + +All right, anything +else on Karatsuba? + +Cool. + +Let's talk about Newton. + +That's the hard stuff. + +And let me see how +we're doing on time. + +OK, doing well. + +So does anyone remember +the point of Newton? + +OK, so I heard an +application that + +lets you compute square roots. + +What else does it let you do? + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: OK, we have +Karatsuba for multiplication. + +You might be able to +do it with Newton. + +Probably not going to be faster. + +But division, definitely. + +So square roots and division. + +So this is why we care about it. + +Now what does it do from +a mathy perspective? + +So what's the mathy +definition of Newton. + +AUDIENCE: Estimates-- + +PROFESSOR: Estimates? + +AUDIENCE: The value-- + +PROFESSOR: OK. + +So, we have a function. + +Suppose it looks like this. + +So, what Newton +helps us do is it + +helps us find a root +of the function. + +And the root is a value x 0 +so that f of x 0 equals 0. + +So this is what it does. + +So when you want +to use Newton, you + +have to set up your +function in such a way + +that your answer is a root. + +OK. + +How does Newton work? + +Yes? + +AUDIENCE: You +start at some point + +where you actually +know the answer to it, + +and then you kind of +draw a approximation. + +So you're just drawing a line +from the point to the root, + +and then just incrementing +down that line. + +PROFESSOR: OK. + +So we start at +some point, right? + +How do we call that point? + +Initial guess. + +Fancy name. + +So we have an initial guess +for what the root might be. + +It's not going to be the right +answer, because otherwise + +why am I bothering with this? + +But it can be too far off. + +We'll say that if +you're too far off, + +you're not going to +converge or you're not + +going to converge fast enough. + +So say we start somewhere +here and, we think, you know, + +this is pretty close. + +It's not quite there, +but it's pretty close. + +What I do from here +on is, you said + +I approximate this function-- + +AUDIENCE: The line. + +PROFESSOR: Yep. + +So what's of the best line? + +The best way to +approximate the function + +with the line is to use +is the tangent, right? + +So here, it sort +of looks like this. + +And if the function +were linear, this + +would be a perfect +approximation and we'd + +get answer in one step. + +OK. + +So this is the tangent. + +And then what we do +with this tangent? + +AUDIENCE: Well, after we +get the equation for it, + +then we find the root, right? + +Or no? + +PROFESSOR: Well, I can't +find the root right away. + +AUDIENCE: The root of that line. + +Of our tangent line. + +PROFESSOR: OK. + +So we find the root +of the tangent, which + +is the point where +it hits the x-axis. + +And what happens +with this point? + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: OK, so this +is our next guess. + +And then we trade. + +So then we draw another +tangent, and the idea + +is that eventually, +you're going to get there. + +And if we go through +the maths, we + +will see that you actually +get there pretty fast. + +So that's why we +like this method. + +So let's see how we convert this +drawing thing into an equation + +that you can write into python. + +Let's label these quantities. + +So, x2, x1-- actually +let's not use 1 and 2, + +because these are the +first two guesses. + +Let's say our current guess is +x and the next guess is x prime. + +So this line and is x1 minus +x, so this guy over here. + +And what's this guy over here? + +f of x. + +Don't be shy. + +It's the right answer. + +So I have f of x here, +x 1 minus x here. + +I also have this angle +here, and this angle here + +is the same angle +as the angle here + +because both of these +lines are horizontal, + +so they're parallel. + +So what do I know +about this angle? + +AUDIENCE: It's tangent. + +PROFESSOR: It's tangent. + +OK. + +The tangent, that's +called the angle alpha. + +What's the tangent of the angle? + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: Sorry? + +AUDIENCE: F of x +over x [INAUDIBLE]. + +PROFESSOR: I think +you're trying to give me + +the formula for x prime. + +Just the tangent. + +Just the tangent. + +AUDIENCE: Oh. + +PROFESSOR: Right? + +Can someone reassure me? + +This is right, right? + +[AUDIENCE AGREES] + +AUDIENCE: I was thinking +the slope of the line. + +PROFESSOR: OK. + +So, yeah, you're +going to give me + +the slope of the line +which lets me compute this. + +OK, I was looking for this. + +OK. + +So now, let's get +what you're saying. + +So this is the tangent, right? + +So, the tangent at a +point of a function + +is the function's derivative. + +So now we're going to write +all these things down and hope + +that we get an equation +that make sense. + +So we have the +tangent of this guy, + +also happens to +be this over this. + +Right? + +This is a right angle +triangle, so the tangent + +is f of x over-- +this is what you + +were trying to tell me, right? + +x1 minus x. + +So now I know that +this is f prime of x. + +OK. + +So, we look at the picture, +we put in everything we know, + +and then we write +an equation here. + +And we solve for-- +sorry, this is x prime. + +So, if we solve +for x prime, we're + +going to get x prime +as a function of x. + +And this tells us, +given a guess here, + +how do we compute +the next guess? + +So once we have +an initial guess, + +this lets us make the +guess better and better + +and better, closer and +closer and closer to x0. + +So, let's solve this +equation reasonably quickly. + +x prime minus x equals f +prime of x over f of x, so + +x prime is-- + +AUDIENCE: Does it matter if it's +x minus x prime or [INAUDIBLE], + +because technically +it's x minus x prime. + +PROFESSOR: Yeah, it +matters, because you're + +going to get the wrong sign. + +Which is exactly what +I'm about to do here. + +AUDIENCE: Oh, OK. + +PROFESSOR: So, I'm not +going very well, right? + +This is wrong. + +AUDIENCE: Yeah, it's because you +flipped your x at your prime-- + +AUDIENCE: x minus x prime +instead of x prime-- + +AUDIENCE: No, I think it's +because f prime of x is on top. + +It should be on the bottom. + +In the second-- +no, third equation. + +Shouldn't those be flipped? + +Because if you move +the subtraction, + +x prime to the left-- + +PROFESSOR: f what? + +AUDIENCE: f of x over +f minus x instead + +of f prime x over f of x. + +Yeah, there you go. + +PROFESSOR: OK, so I can do math. + +OK, so that's one issue. + +There's one more issue. + +So, there are too +many issues here. + +Issue number one, this. + +Issue number two, +I got this wrong. + +AUDIENCE: Oh, we get +a negative number. + +AUDIENCE: 2x minus x prime. + +PROFESSOR: Yep. + +So the reason for +that is we're going-- + +AUDIENCE: Only if you start +from the right, though. + +PROFESSOR: Yeah. + +AUDIENCE: If you +start from the left, + +if your guess is to the +left of the actual root, + +it may or may not be different. + +PROFESSOR: OK. + +So our guess should +be to the right. + +So this is x minus x prime. + +So the reason it's x minus x +prime, the way you remember + +this and you don't do the +same mistake that I did + +is, you want to walk +against the derivative. + +If you walk in the +direction of the derivative, + +it's going to move +you forward, right? + +So, if you go in the +direction of the derivative, + +instead of going +backwards like this, + +you're going to go +forward like this. + +So you're going to go +away from the solution. + +So, this will take us +in the right direction, + +and this means that it's-- + +OK. + +So two ways to remember this. + +One that you're going +against the derivative. + +Another one is that +you have your guess + +and you're subtracting +something from it. + +AUDIENCE: You flipped +your primes again. + +PROFESSOR: Again? + +Jesus. + +[LAUGHTER] + +AUDIENCE: I mean, I +agree, the prime looks + +better on top part of +the fraction, but still. + +PROFESSOR: OK. + +Well clearly, my hand +thinks the same thing. + +So this is you'd +iterate using Newton. + +So the way to remember +that the signs are right + +is your x is somewhere +here, and you + +know you have to subtract +something from it so it looks + +like this figure. + +And this actually works in +all the cases, turns out. + +Our guesses are usually +smaller than the actual number, + +and this still works. + +OK, so let's go over Newton. + +What do we have, or +what do we need in order + +to make Newton happen. + +So we need to be able +to evaluate this, right? + +So we need to be +able to evaluate + +f over f prime of x for +any x that Newton gives us. + +And for Newton, +this is a black box. + +So whichever way +you use to implement + +this is fine, as long as +it works reasonably fast. + +OK, what else do we +need to use Newton. + +We need to remember this formula +Let's start with something + +easy. + +Suppose we want to use +it to compute a over b. + +How do I do that? + +What do I need? + +AUDIENCE: You need a +line, a tangent line + +like you did before. + +PROFESSOR: Well, that's +already taken care of here. + +So we have this, and +we know that we'll + +have to compute this +and plug it in here. + +So, what do I need to +compute a/b using Newton? + +So, I need the function, right? + +This thing. + +I can't say it's something, I +have to figure out what it is. + +I guess I was confusing because +I said assume we have this. + +Well, sorry. + +We don't have this. + +We need to figure +out the function + +so we can evaluate this. + +OK, so we need to come +up with the function + +so we can evaluate +that, and what property + +does the function need to meet? + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: Yeah, that +would be nice, right? + +So we want the function +so that f of a/b equals 0, + +because that's the number +that Newton will give us. + +And we also need to be able +to compute f over f prime of x + +without doing any +division, right? + +If we did the divisions, +it doesn't work. + +OK, so the first thing +we're going to do + +is we're going to simplify this +problem to 1 over b instead + +of a over b, because if +you know what's 1 over b, + +you're going to +multiply this by a, + +and you're going +to get a over b. + +Suppose we work +with integers and we + +don't want to touch +floating point numbers. + +What would we actually compute? + +AUDIENCE: You shift +it out, right? + +To get that 0.23, shift +now to [INAUDIBLE]. + +PROFESSOR: All right, all right. + +So 1 over b. + +Unless b is 1, in which +case it's really boring. + +1 over b looks like this. + +0 point something. + +This is not an integer number. + +I don't like it. + +So what I do is, +I decide that I'm + +going to need +digits of precision, + +and I'm going to shift +the decimal point + +right by d digits. + +So instead of 0 +point something, it's + +d digits here point +something else. + +How do I do this? + +AUDIENCE: Multiply +by 10 to the d? + +PROFESSOR: Multiply +by 10 to the d. + +So instead of computing 1 +over b, 10 to the d over b. + +And we call this 10 to the +d R in our station notes. + +So we're going to compute +R. Over b multiplied + +by a, and then +everything divided by R. + +So we talked about +how you multiply + +by R. How do you divide by R? + +So, if I have a +number with n digits + +and I want to divide by 10 +to the d, how do I do that? + +AUDIENCE: Shift. + +PROFESSOR: Shift right. + +If the number is a python list? + +AUDIENCE: Slice it. + +PROFESSOR: Yep. + +So kill the last d digits. + +So, if I add d +digits to the right, + +I multiply by 10 to the d. + +If I slice the last digits, +I divide by 10 to the d. + +So this is division, +this is multiplication. + +And the reason I care +about that is this + +is going to be an easy division, +and whenever I have this, + +it's an easy multiplication. + +OK, now what function +am I going to use? + +Does anyone know? + +Can I use x minus R +over b equals zero? + +AUDIENCE: Sure? + +PROFESSOR: Well, so, this is +f of x. f prime of x is what? + +AUDIENCE: Just +negative R over b. + +Or no, 1. + +PROFESSOR: OK. + +So, f prime of x over-- + +AUDIENCE: I think you +switched it again. + +[LAUGHTER] + +PROFESSOR: Thank you. + +Because I was running ahead, +and I was like, OK, this works. + +Why does it work? + +OK, so this is going to be +x minus R over b, right? + +Can you evaluate this? + +If I can't evaluate this, +I already know the answer. + +AUDIENCE: Your prime's +not on the bottom one. + +PROFESSOR: So, it's x +minus this divided by 1. + +So, it's this. + +So then, if you're trying to +evaluate this far the guesses + +that Newton gives +you, you can't. + +Because if you could, you'd +have the answer already. + +So we can't use this function. + +This is a nice and easy +function that doesn't work. + +So while I erase the +board, one minute, someone + +figure out the right function. + +Sorry? + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: Man, +that's hard math. + +No, that's too hard. + +That's too hard. + +OK, let's try this. + +Let's try instead +of x minus R over b, + +let's try this 1/x minus b/R. +And the intuition behind this + +is if I have to compute +b/R, I can do that. + +Right? + +It's an easy division. + +If I somehow get rid of +1/x and all I have to do + +is compute b/R, it's +an easy division. + +Because dividing by +2 to the R by R means + +you're going to shift by +some digits to the right. + +So let's see if the math +works out for this function. + +What's f prime of x? + +AUDIENCE: Negative +1 over x prime? + +PROFESSOR: All right. + +Like, does no one know it? + +At least one student +has to know it. + +OK, so f of x divided +by f prime of x is what? + +AUDIENCE: Negative x +plus x squared b/R. + +PROFESSOR: Plus x squared b R. + +AUDIENCE: Yeah. + +PROFESSOR: Is this right? + +AUDIENCE: Yes. + +PROFESSOR: OK. + +So if I have my initial guess-- +so if I want to get x prime, + +x prime is x minus f of x +over f prime of x, right? + +So, what is it? + +AUDIENCE: 2x minus x +squared over R. OK. + +Did this work? + +Did it get rid of all +the hard divisions? + +[LAUGHS] + +Please nod so I know +we're good to go. + +Tell me if we're not. + +So how many divisions +did we have here? + +One division, this guy, right? + +AUDIENCE: But that's a shift. + +PROFESSOR: That's a shift. + +Because R is 10 to the d. + +AUDIENCE: What about the +multiplication [INAUDIBLE]? + +PROFESSOR: So, we know +how to do multiplication + +because we learned +Karatsuba just now. + +So we wanted to get +rid of division, + +because if you're +trying to solve division + +by doing division, +it's probably not + +I'm going to work unless you're +doing divide and conquer. + +OK, so this is how it works. + +I'm not going to run into +the error formulas for this + +because I want to do +another case first. + +You can keep going on this +and it's in the notes. + +The only thing that +is useful to remember + +is that we use this trick. + +So, I want to look at this +function, square root 3 of a, + +and I want to use +Newton to compute it. + +So this is the third order root. + +It's not the regular square +root that we had before. + +So we're trying to +not be boring and not + +just repeat what's in the notes. + +How do I do this? + +Let's walk through the steps. + +So what's the first +thing that we do? + +Very good. + +Look to the right. + +Find the first step, +and let's put it here. + +What's the first step. + +AUDIENCE: Function f +of 0 at cube root of a. + +PROFESSOR: OK. + +So we need a function +f so that f of-- good. + +So before we start writing +the actual function, + +what if I want to +compute cube root + +of a up to d digits +of precision? + +So if I want to +compute cube root of 2, + +this is going to give me +numbers that are below 1. + +I have to do with +fractions again. + +I don't like that. + +If I want the digits of +precision, what do I do? + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: Jumping ahead. + +But yeah. + +So you have the right answer, +but you're speaking slowly + +because you're afraid you're +going to do a mistake, right? + +So, the way to compute this +to d digits of precision 10 + +to the d, right? + +This shifts the +dot to the right. + +So I have to get this +10 to the d inside here, + +and I get and to the 3d times a. + +Perfect answer, by the way. + +Don't forget this 3 here. + +If you do, you're going +to get something else. + +So now I take this guy, +and this is the new number + +whose cube root I +have to compute. + +Cube, cube, cube. + +OK. + +So I can do this +in integer land, + +and then I'll get +an integer result, + +and I shift it +right by d digits, + +and I have a number with +d digits of precision. + +Does this make sense? + +OK, what's f? + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: Let's go for that. + +Let's see if that works. + +x cubed minus a. + +Well, let's pretend. + +We're going to make +this b the new a. + +So let's not to +worry about this. + +This happens somewhere else. + +We went through +it so that we know + +that we know how +to deal with it. + +And now we're going +to forget about it. + +So, it's x cubed minus a. + +Because we argued that +this is an integer, right? + +So we don't have to do anything +fancy like dividing by R + +that we had to do over there. + +So, what's f prime of x? + +OK. + +So, iteration? + +How do we iterate? + +AUDIENCE: x prime? + +PROFESSOR: Let's start +with x prime equals + +x minus f of x +over f prime of x. + +Right? + +Nice and easy so +we have it here. + +And this becomes minus copy +these two things, right? + +x cubed minus a over 3x squared. + +OK. + +Next thing, I bring this +guy under the denominator, + +so it's 3x cubed minus x +cubed plus a over 3x squared. + +So it's 2x cubed plus +a over 3x squared. + +So this is 2/3 plus-- + +AUDIENCE: 2 over 3x. + +You keep saying +cubed and writing 2. + +PROFESSOR: Yeah, that's better. + +Thank you. + +Plus 1/3 times a over x. + +So this one's division. + +AUDIENCE: x squared. + +PROFESSOR: x squared. + +Ouch. + +So this guy wants division. + +By the time I do this, I better +have division ready, right? + +OK, so that my iteration. + +x prime is 2/3 x plus +1/3 and a over x squared. + +What else do I need? + +An initial guess +would be nice, right? + +I can't do this if I +don't have the first x. + +So let's try to think of a +starting x that's reasonable. + +The better it is, the +faster it's going to be. + +So let's try to come up with +something reasonable that + +doesn't require too much +thinking or too much. + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: Too much work. + +I have to compute a square root. + +So what's a? + +Let's start with that. + +What's an a, right? + +So, it's an n digit number. + +And say the digits are d1, +d2, d3, all the way up to dn. + +So what's a good approximation? + +Well, the first +approximation for this? + +AUDIENCE: You get a +third as many digits. + +PROFESSOR: A third +as many digits. + +OK. + +So something times +10 to the n/3. + +Let's say that +something is 1, right? + +So this is the +first approximation. + +It's the right +order of magnitude. + +Do people see why this +is a good approximation? + +So this number, +whatever it is, it + +has to be between 1, +0, 0 0, 0, and 1, 0, 0. + +OK. + +So generally when +we do this, what + +we have to have in +an approximation + +is the right order of magnitude +And maybe the first digit. + +If we can figure +out the first digit, + +then we're in a good +shape, or something really + +close to the first digit. + +How would we get +the first digit? + +AUDIENCE: Cube root +of the first digit? + +PROFESSOR: OK. + +Sure. + +How do we compute this? + +AUDIENCE: Get a formula? + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: OK, so I'm not +going to argue with that. + +AUDIENCE: I like that. + +PROFESSOR: So I want to reject +the recursive argument first. + +So this is going +to be small, right? + +This is going to be 10 if +you're working with digits, + +or if you're a computer, +maybe it's 256, + +or maybe it's 2 to +the 16 or 2 to the 32. + +Not much bigger +than that, right? + +Pretty small. + +So these algorithms really +good for big numbers. + +Algorithms that are +complicated but have + +nice asymptotic complexity +are good for big numbers. + +They're awful for small numbers, +as in they 10 to 100 times + +more times to run. + +So let's not to +do that for this, + +because it's like +bringing a tank + +and shooting it so you +can hammer a nail in. + +Not the right tool. + +So, precomputed list. + +I like that. + +It's an option, especially +if you're [INAUDIBLE] right? + +You can use pen and +paper to get it. + +What if I don't want to do that. + +What if my base is +more like this.? + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: So this is +a very good solution. + +I'm not arguing with it. + +If your power is this or this, +by all means, use a table. + +So let's see what do we do here? + +I just want to think +a little bit more. + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: OK, so there's +some approximation + +that comes from math +that says that d1 over 3 + +is not going to be +such a bad guess. + +Now let's be CS people +and do something better. + +AUDIENCE: [INAUDIBLE] +the exponent. + +2 to the 14, divide-- +is that 14, right here + +AUDIENCE: 16. + +AUDIENCE: 16. + +Divide 16 by 3. + +Or I guess that's not +quite right either. + +PROFESSOR: So you're saying +2 to the power of, say, 5? + +15 over 3? + +AUDIENCE: It doesn't +seem quite right. + +PROFESSOR: So, let's +try to do better. + +This is math. + +Let's just try to +do it in a CS way. + +So we're trying to guess a +digit between 0 and 2 to the 16. + +I heard an "oh." + +Yes? + +You had your hand up? + +No? + +OK. + +AUDIENCE: You take the +current time 2 to the 16. + +I mean-- + +[LAUGHTER] + +PROFESSOR: So your +algorithm is going + +to be fast with some +probability, right? + +No, that's terrible. + +Let's not do that. + +Please don't make me +grade code like that. + +AUDIENCE: Did you already +cut out the recursive option? + +AUDIENCE: Yes. + +PROFESSOR: Yeah. + +Well, so I don't want to +recurse on square roots. + +AUDIENCE: But you could +recurse on that one. + +PROFESSOR: I mean, +if you give me + +some algorithm that happens-- + +AUDIENCE: You're +already [INAUDIBLE]. + +PROFESSOR: OK. + +So, what's the intuition? + +If you have a computer +and you have register, + +bytes, bits, whatever. + +You don't know how +to do square roots. + +That's not an instruction, but +these are all instructions. + +Right? + +So if I have a guess, +say I start with half + +and then I get my guess, what +do I need for the binary search + +to work? + +Given a guess that's +somewhere here, + +I have to be able to say whether +this is too small, too big, + +or just the right number. + +So given a guess, I can multiply +it by itself three times, + +right? + +Compute gets cubed. + +And I can see how does +it compare to the number + +that I want. + +So I have the first digit, and +I have an order of magnitude. + +Not bad, right? + +Pretty good initial guess. + +This is as much of an answer +is you need to give out + +in physics problems, and you +get full score, so that's good. + +OK, how are we doing so far? + +Following along? + +AUDIENCE: If we compute +our guess cubed, + +we want only to compare +it to our original number + +to see how close it is? + +PROFESSOR: Yup. + +AUDIENCE: And, do we just +keep on doing that until-- + +PROFESSOR: Well, so you're going +have to guess a digit, right? + +Between 0 and 2 to the 16. + +So you choose the largest thing +that's smaller than your guess, + +or something. + +AUDIENCE: Or until we +get the first digit. + +PROFESSOR: Yeah. + +Just the first. + +And then you have a +first digit, and then you + +have an order of magnitude. + +And then you feed +that to Newton, + +which converges way faster. + +So you could the binary +search for the whole thing, + +but that would be slower +than Newton, turns out. + +Yes? + +AUDIENCE: So where'd +you get the f of x here? + +I'm missing that stuff. + +PROFESSOR: Oh. + +AUDIENCE: Yeah, right there. + +PROFESSOR: Someone +told me to use this. + +[LAUGHTER] + +One of you guys +told me to use this. + +Well, so I tried it out. + +I put it here. + +And then I computed +the derivative, + +and I looked to see if +this looks reasonable. + +And this looks like +something I can compute. + +AUDIENCE: And why +was that reasonable? + +PROFESSOR: Because I know +how to do the division + +and multiplication. + +So, say if I would have had +the square root of 3 in here, + +that wouldn't be +reasonable, right? + +Just like before. + +When you're trying +to compute division, + +we can't have division. + +If you're trying to +compute sine of x, + +you don't want to +have sine of x. + +AUDIENCE: OK. + +and computing a over x +squared is reasonable? + +PROFESSOR: Because +we did it before. + +AUDIENCE: OK. + +So then you might use +something else, maybe? + +PROFESSOR: Yeah. + +You can use something else as +long as you know how to do it, + +and as long as it's +reasonably fast. + +AUDIENCE: OK. + +PROFESSOR: Yes? + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: Oh, no that's fine. + +AUDIENCE: Oh, that fine? + +OK. + +PROFESSOR: So, the +binary search is + +fine to get the +first approximation. + +But after that-- +so I'm not going + +to do a binary search +for the whole result, + +because Newton is +faster than that. + +I'm just using this so +that I have a decent guess + +to pass to Newton. + +And we'll see why we need that +decent guess in two minutes + +total. + +So I'm going to try to +spend two minutes to explain + +how the error thing +works, and you'll + +have to look at the +notes and make sense out + +of the rest of it. + +So, let's see. + +Errors. + +So with Newton, you start +to with an initial guess, + +and then you get to a +better guess, and a better + +guess, and a better guess, +and so on and so forth + +until you're satisfied. + +By the way, if we're doing +this one, are we satisfied? + +AUDIENCE: What do you mean, +like, finding the guess? + +Are we satisfied? + +PROFESSOR: Oh, no. + +So, we have the initial guess. + +And we keep applying the formula +that I just deleted to iterate. + +When do we stop? + +AUDIENCE: When we have +enough digits of precision? + +PROFESSOR: So how do we know +when we have enough digits, + +if we're working with integers? + +AUDIENCE: We iterate +again and nothing changes. + +PROFESSOR: We iterate +again and nothing changes. + +So I'm computing-- do +I have this anywhere? + +Oh, no. + +I erased it. + +So I'm computing 10 t0 +some-- oh, I had it up here. + +So, I'm computing +10 to the power + +of d times a square +root of 3, because I + +want to work with integers. + +Just integers. + +I used Newton to iterate. + +My precision gets gets +better and better and better. + +And I use integers. + +So I only have d +digits of precision. + +Everything after that gets +discarded automatically. + +When I get 2 x's that don't +change-- so if I get x5, + +and then I run +the thing and then + +I get x6 that is +equal to x5, there's + +no point to keep +running Newton, right? + +I;m stuck. + +And I'm also done +because I have the answer + +with d digits of precision. + +So this is where I stop. + +OK. + +Now, my precision is how far +I am from the right answer. + +And we write that +by saying that x1 + +is x, the true answer, times +1 plus epsilon, epsilon 1. + +And then x2 is x times 1 plus +epsilon 2, 1 plus epsilon 3, + +so on and so forth. + +Right? + +So, if we had a lot of time +and not too much stuff to do, + +I could copy this thing here +that we have in the notes. + +That's eight lines of math. + +And then we'd get something +along the lines of x of i + +plus 1 is x times 1 +plus something times E + +squared-- I'm sorry, Ei squared. + +So this is also +1 plus Ei plus 1. + +So what we get is that E of i +plus 1 is roughly E i squared. + +And this is what's really +called quadratic convergence. + +Now why is this good? + +Can anyone think intuitively +why this is nice? + +In which cases? + +Yes? + +AUDIENCE: You're converging +really quickly to your answer. + +PROFESSOR: OK. + +But when do I converge? + +, So what I want this to happen? + +What do I want this to be? + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: Well, you +guys told me everything + +I need for the next two minutes. + +So, I want this to +become 1, right? + +This has to go to 1 because I +want this whole thing to be x. + +So in order for this to be 1, +I want to epsilons to go to 0. + +So I want them to be +as small as possible. + +Now, you said that if my +epsilon is smaller than 1, + +then epsilon squared is +smaller than epsilon. + +And intuitively, +how this works is, + +suppose you start with +an epsilon of 0.1. + +When you square +it, you get 0.01. + +You square it again, +you get 0.0001. + +Square it again. + +0.00000001. + +OK. + +This is step 0, step +1, step 2, step 3. + +How many digits do I have here? + +Don't be shy. + +AUDIENCE: 2 to the i? + +PROFESSOR: Yup. + +2 to the i. + +So this is going +to be equal to this + +when 1 plus x times 1 plus +epsilon i over 1 plus epsilon-- + +sorry, i plus 1 epsilon i +when the floor of this thing + +is-- sorry, there is a +delta somewhere here. + +So, something has +to converge to 0. + +Sorry, this is what it is. + +1 plus e of i. + +So this is the difference +between two terms, x. + +So this is x6 minus x5, right? + +Convincing? + +AUDIENCE: [INAUDIBLE]. + +Let's write it again. + +Let's write it again. + +This is out of hand. + +So, x, x minus x5, +or actually, xi + +plus 1 minus xi is equal +to x times 1 plus epsilon i + +plus 1 minus x times 1 +plus epsilon i, right? + +So this is x times-- Sorry? + +AUDIENCE: Those are xi, x of i. + +AUDIENCE: No, those +are the real x's. + +PROFESSOR: These are-- so +these are the approximations, + +but then, this is the real x. + +AUDIENCE: I +understand, thank you. + +PROFESSOR: OK. + +So, this is, the difference +between them is this guy here. + +So if I take the floor +because I work with integers, + +when this floor becomes +0, we're done, right? + +So in order for the +floor to become 0, + +this guy has to be +canceled by this guy. + +So this guy has some number +of digits, whatever that is. + +It's my number with d +digits of precision. + +Well, that's OK +because-- where my 0s? + +Did I erase my 0s? + +Oh, no. + +I have 0s here, right? + +The epsilons have a +lot of 0s in them, + +so the 0s are going to +cancel the digits in x. + +So as soon as I have enough 0s +here to cancel this, I'm stuck. + +The number of 0s +increases exponentially. + +So in each step the number +of 0s I have doubles. + +So after log d steps, I'm done. + +If I have d digits +in here, because I'm + +computing this with d +digits of precision, + +after roughly log d steps, +I'll have enough 0s here + +to reduce this and make +the whole thing be 0. + +So this is how I +know that it's fast. + +So in the end, what you +want is the initial guess + +has to satisfy +this, and then you + +want to be able to +prove that this is true. + +So you want this factor +here that tells you you're + +converging fast. + +So when you look at +the recitation notes + +and you look at this +long string of equations, + +make sure this is +somewhere there, + +because this means you're +on the right track. + +Yes? + +AUDIENCE: If it +takes log d steps, + +doesn't the binary search +also take log-- ah, OK. + +Log 10 steps. + +Got it. + +PROFESSOR: Yeah. + +Which is d. + +AUDIENCE: He's talking +about binary search-- + +PROFESSOR: Oh, for one digit. + +Yeah. + +Oh, sorry. + +I thought you meant +for the whole thing. + +So if you wanted to do binary +search for the whole thing, + +that's log of the whole number. + +So that's order d where d +is the number of digits. + +AUDIENCE: Wait, he's talking +about a binary [INAUDIBLE]. + +AUDIENCE: [INAUDIBLE]. + +AUDIENCE: [INAUDIBLE] wants +to go for [INAUDIBLE], 10 + +to the 20th. + +He wants to do a binary +search over like a cube root-- + +PROFESSOR: So, for this? + +Binary search for +this or for one digit? + +Or binary search to +compute the cube root? + +AUDIENCE: I think, yeah. + +PROFESSOR: So, if you do +that, your entire thing is + +d digits, right? + +So 10 to the d. + +Binary search takes +log of 10 to the d. + +AUDIENCE: Right, yeah. + +PROFESSOR: So the +numbers that we're + +dealing with are d digits. + +So this d is the number +of digits, not the number + +that you have. + +So if you look at the +number that you have, + +this is log log n. + +AUDIENCE: Right, +that makes sense. + +Sorry. + +PROFESSOR: So, it's faster. + +AUDIENCE: I like it. + +It is faster. + +PROFESSOR: OK. + +Cool. + +Thanks for the lesson. + +AUDIENCE: [INAUDIBLE]. \ No newline at end of file diff --git a/Jfibd3L_E_o.txt b/Jfibd3L_E_o.txt new file mode 100644 index 0000000000000000000000000000000000000000..321eee348d3818f005523539162bf3e1cc29173f --- /dev/null +++ b/Jfibd3L_E_o.txt @@ -0,0 +1,1708 @@ +The following content is +provided under a Creative + +Commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high quality educational +resources for free to make a + +donation or view additional +materials from hundreds of MIT + +courses, visit MIT +OpenCourseWare at ocw.mit.edu. + +PROFESSOR: Ladies and gentlemen, +welcome to this + +lecture on non-linear finite +element analysis of solids and + +structures. + +In the previous lectures, we +have considered quite a bit of + +theory related to non-linear +finite element analysis in + +some example solutions. + +The objective in the next two +lectures now, the last + +lectures of this video course, +is to show how an actual + +finite element analysis is +performed on the computer. + +We start with a linear solution +in this lecture, and + +then consider a non-linear +solution in the next lecture. + +We cannot discuss really, in +this amount of time given, all + +the aspects of the analysis, +but want to summarize and + +demonstrate on the computer +the major steps of the + +analysis and concentrate on +possible difficulties, + +possible pitfalls, and some +general recommendations. + +As the example problem, we want +to use the plate with a + +hole, that we already +considered earlier. + +And we performed a linear +analysis and then + +a non-linear analysis. + +Remember, I pointed out in the +previous lectures that it is + +very important to always do +linear analysis first before + +you go into a non-linear +analysis. + +The elastic analysis is +performed to obtain the stress + +concentration factor at the +hole, then we do an + +elasto-plastic analysis to +estimate the limit load, and + +an analysis also to investigate +the effect of a + +shaft in the plate hole. + +These two analyses are being +performed in the last lecture + +of the video course. + +The plate we are analyzing is +shown on this view graph here. + +Notice it's a square plate. + +Here, we show the hole, the +plate is loaded as shown up + +here, and down here. + +The material property for the +elastic analysis are given + +here and the thickness of +the plate is 0.01 meter. + +Because of symmetry conditions, +we only need to + +consider this quarter here. + +Of course, using appropriate +boundary conditions along + +these two lines. we will talk +about that more later on. + +The first step for a finite +element analysis is to select + +a computer program, and we, of +course, use the ADINA system. + +ADINA-IN is the pre-processor +to prepare, generate the + +finite element data. + +ADINA then solves the actual +finite element model, and + +ADINA-PLOT is used to this +display numerically or + +graphically the solution +results. + +Schematically, we are sitting +here at a terminal and we're + +inputting the data +to ADINA-IN. + +We can also receive here, +numerical output, and we can + +also plot on this terminal here, +any of the information + +that we like to plot. + +This is a graphics terminal. + +Notice ADINA-IN, of course, +communicates to a storage + +device and further on +to ADINA, as we will + +discuss just now. + +The user inputs, in +other words, or + +types into the terminal. + +ADINA-IN commands interactively +or for batch + +processing and then the user +checks also the input and the + +generated data on the graphics +device, as I showed you on the + +previous view graph. + +ADINA-IN generates the +input data for ADINA. + +The input data is checked +internally in ADINA in for + +errors and inconsistency, and +also is displayed as you are + +requesting it as a user. + +The degree of freedom numbers +are generated and to obtain + +minimum bandwidth, we have a +minimum bandwidth minimization + +algorithm in the program, as +I will point out a bit + +stronger later on. + +ADINA data inputs then, is +available to ADINA, and the + +user runs ADINA, and ADINA then +stores the output data on + +a porthole file and +on an output file. + +The output file, in other words, +contains really the + +ADINA model data and the +calculated results. + +We access ADINA porthole +file using ADINA-PLOT. + +We can, of course, also look +at the output file and see + +numerically the data that was +calculated using ADINA. + +Here, we have the action +displayed or schematically + +shown by the user. + +User uses ADINA-PLOT to fetch +data from the ADINA porthole + +file and then ADINA-PLOT +displays those data either + +numerically or graphically. + +Let's look very briefly at +an overview of ADINA. + +The program can be used for +static and dynamic solutions, + +for linear and non-linear +analysis, for small and very + +large finite element models, +and the formulations finite + +elements and numerical +procedures used in the program + +have largely been discussed +in this course. + +The displacement assumptions +that can be employed for the + +finite element models are either +infinitesimally small + +displacements, large +displacements, large rotations + +but small strains, and large +deformations, large strains. + +We discussed these assumptions, +of course, also + +in the course. + +Material models that are +available in isotropic linear + +elastic model, orthotropic +linear elastic model, + +isotropic thermo-elastic model, +a curve description + +model for analysis of geological +materials, a + +concrete model, isothermal +plasticity models, + +thermo-elastic-plastic and creep +models, and non-linear + +elastic incompressible, and +user-supplied models. + +The elements available in the +program, is available number + +nodes tress element, an element +that can have two + +nodes, three nodes, +or four nodes. + +It can also be used +as a ring element. + +A two-dimensional solid element +that is used for plane + +stress axis symmetric and +plane strain analysis. + +This also can have available +number of nodes, from four + +nodes to nine nodes. + +Similarly, available number +of nodes element for + +three-dimensional analysis. + +Then also a beam element, a +2-node beam element, Hermitian + +beam element. + +And the isoparametric beam +element that we talked about + +in the course. + +This element can carry, or can +be used with two nodes, or + +three nodes, or four nodes. + +A pipe element that we did not +discuss in the course, but you + +might be interested in reading +about that element is a curved + +beam element, of course, +of pipe section. + +Which however, also includes the +effects of ovalization So + +this element also carries, if +desired ovalization degrees of + +freedoms at the nodes. + +And shell elements, we talked +about the use of the 16-node + +element, and the MITC 4, +the 4-node element. + +We also talked briefly about +transition elements that I + +used to model shells, +or thin structures + +that couple into solids. + +Let us summarize some important +observations + +regarding finite element +analysis. + +It's important to check the +finite element data, of + +course, very carefully. + +The data must be checked +prior to the + +actual response solution. + +This is done, of course, with +the pre-processor, by plotting + +the data, looking at it very +carefully, typically. + +And then after the response +solution, you still want to + +check the input data once more +by seeing whether the boundary + +conditions are properly +satisfied, that you want to + +impose on to the model, whether +the displacement and + +stress solution is +a reasonable. + +Once the analysis has been +performed, you want to very + +carefully evaluate +and interpret + +the calculate response. + +You want to start in detail the +calculated displacement + +and stresses along +certain lines. + +In particular, look +at stress jumps. + +We pointed that out already in +an earlier lecture, and we + +will do so in our example +solution again, just now. + +And here, I'd like to add that +stress averaging, stress + +smoothing should only be done +after the above careful + +evaluation. + +That's something important +to keep in mind. + +I believe that you should first +look at the stresses, + +the way they have been +calculated by the program and + +then start thinking about +stress smoothing. + +Only after you've gone through +this phase here. + +The data for the construction +of the finite element mesh, + +that we want to deal with in the +example solution is input + +for this quarter of +the plate, as I + +pointed out earlier already. + +We have these elastic material +constants, we're looking at a + +plane stress analysis. + +This is the thickness +of the plate. + +And once again, here +is a loading. + +Notice, we are putting this +boundary on rollers, and we + +want to put this boundary as +well on rollers to model the + +symmetry conditions that we +need to model in order to + +consider a whole plate, where we +actually analyze here, only + +one quarter of that plate. + +The finite element mesh that we +will be using is shown on + +this view graph. + +It consists of 64 8-node +isoparametric elements. + +Well, we performed this analysis +on the computer in my + +laboratory at MIT a few weeks +ago, and we have brought in a + +video crew to record all the +actions that we have been + +performing to actually complete +the analysis. + +I like to now share with you +what we have recorded and + +narrate to you as we go step by +step through the analysis + +of this plate on the computer. + +Our first step is to look at +how we are generating using + +ADINA-IN, how we are generating +this mesh, and also + +the other data that are required +for use of ADINA. + +So let's look at this first step +now, after which I will + +then introduce you to the next +step and narrate continuous + +narration of the analysis. + +Here we show briefly the +hardware equipment we are + +using in my MIT laboratory. + +A MASSCOMP minicomputer with two +megabytes of real memory, + +and 330 megabytes +of disk storage. + +We also have a tape drive. + +The computer features virtual +memory, and we use a + +Unix-based operating system. + +Roughly, for our purposes, +the computer is + +equivalent to a VAX 750. + +We use two terminals. + +One terminal for alphanumerical +and numerical + +input and output, and one +terminal, the one to the + +right, for graphical output. + +We also have a plotter. + +We use this plotter to generate +the figures of finite + +element meshes, and results +for this course. + +Here comes my student, +Ted [? Sossman, ?] + +who will sit at the +terminal to input + +the data to the program. + +In what follows, we will see the +data input prepared by Ted + +on the terminal at +which he sits. + +Non-graphical output is +displayed by that same + +terminal, whereas we will see +graphical output displayed on + +the right terminal. + +Here, we see the start of input + +preparation for ADINA-IN. + +We have opened the data base, +on which the data input and + +generated will be stored and +have already input the title + +for the analysis, quarter plate +with hole, 64 elements. + +We have also defined master +degrees of freedom conditions + +by specifying the +values of IDOF. + +1 means of a deleted degree of +freedom, 0 means a free, + +existing degree of freedom. + +Here, all degrees of freedom +have been deleted except for + +the yz displacements. + +Notice also that at +our request, all + +text appears twice. + +After we have typed a line, the +line is echoed back by the + +program merely for checking. + +In what follows, we now specify +the coordinates of a + +few key points that defines +the outline of the + +quarter of the plate. + +Note we define the y- +and z-coordinates. + +First of node 1, then for +nodes 2, 3, 4, 5, and 6. + +Note that these coordinates +are input in free format. + +Here the node 6 input is not +aligned with the other nodal + +point coordinate input. + +We now want to look at the plot +of these nodal points. + +This is achieved by the frame +and mesh commands. + +Here they are, the six points. + +Point 1 is the center of the +hole, points 2 and 3 defines + +the boundary of the hole. + +Points 4, 5, 6 defines the +remaining corners of the + +quarter plate. + +And here, you see the first +set of generated nodes. + +Note that the nodal points have +consecutive numbers along + +the vertical symmetry edge, +except for the top and bottom + +nodes, numbers 3 and 4, +similarly for the horizontal + +symmetry edge. + +This would mean a large +bandwidth unless we use a + +bandwidth minimizer. + +And we will do so, hence we +are not concerned with the + +nodal point numbering +used at this stage. + +Next, we generate also the nodal +points on the remaining + +edges of the quarter plate. + +And here they are. + +We now want to generate the +elements of the plate. + +For this we define, first the +material to be a elastic. + +Young's modulus E, Poisson's +ratio NU. + +We want a plane stress +element group. + +The Gauss integration +order is 3x3. + +The material set has a number 1, +this is the material set we + +just defined. + +The G-surface command next +generates the 8-node elements + +in the domain defined by the +corner points, so to + +say 6, 4, 3, 2. + +We now want to plot the +generated element mesh, and + +here, you see it. + +Note once again, we use 8-note +isoparametric elements, around + +the hole, they are +curved elements. + +Finally, we also define in the +ADINA-IN input the elements + +thicknesses to be 0.01 and the +loads which correspond to the + +pulling on the plate. + +This [? end ?] completes +the input preparation + +for ADINA-IN . + +ADINA-IN has now all the +information to generate a + +complete input file ADINA. + +In addition, we also want to +ask ADINA-IN to assign + +equation numbers that correspond +to a minimum + +bandwidth for the solution +of this problem. + +So our next step is to have +ADINA-IN go through these + +actions, and turn back to our +laboratory and see what is + +happening now. + +Here, we see the end of the +ADINA-IN input file that we + +saw already before. + +The command ADINA now generates +the ADINA file. + +At the same, also, the bandwidth +of the stiffness + +matrix is minimized. + +We use the reverse Cuthill-Mckee +algorithm. + +Notice that the bandwidth has +been reduced from 399 to 93. + +The original bandwidth was, of +course, artificially large + +because our nodal point +generation did not take + +account of any bandwidth +considerations, as I pointed + +out before. + +Let us briefly look +at the ADINA file + +generated by the ADINA-IN. + +Here, we see common cards, +automatically inserted by + +ADINA-IN to explain +the input cards. + +We see the master control card, +the load control card, + +the Eigenvalue solution control +card, and so on. + +Let us look a bit closer at +the element data cards. + +Element 1 has eight nodes and +the first three are 6, 64, 74. + +Element 2 has 8 nodes and the +first three are 64, 62, 76. + +Note a maximum of nine +nodes is possible. + +The last 0 is the node card +signifies that the ninth node + +is not used. + +With a complete ADINA input +file now available, we can + +call ADINA to execute this file +and this gives us our + +first solution results. + +We look at the solution results +and, in particular, we + +plot the deformed mesh onto the +original mesh, and this + +shows, in fact, that we have +made an error in the input + +description. + +It will show us that we have +fixed all these nodes down + +here, whereas they should +have been on a roller. + +This is shown by plotting the +deformed mesh on to the + +original mesh, and it's +also shown by + +looking at the stresses. + +We do so by using an option in +the ADINA system for the + +stress vector outputs, and this +is schematically shown + +here, this option. + +We plot maximum principle +stresses-- + +say tensile in this +case here-- + +as a line with two arrows, and +principles stress that's + +compressive as simply a line. + +So we can see, in other words, +how the stress flows through + +the material, and we can see, +of course, compressive and + +tensile stress situations, and +notice that the lengths of + +these lines corresponds or is +proportional to the magnitude + +of the stresses. + +We can plot this stress vector +output for all the integration + +points stresses in the mesh, and +that, as I said already, + +indicates clearly once again, +that we have used the wrong + +boundary conditions down here. + +So we go and correct the +boundary conditions down here, + +and re-run the analysis. + +In other words, call ADINA again +and those results that + +we obtained then, once again, +displacements, in other words, + +are plotted by plotting the +deformed mesh onto the + +original mesh. + +We see that we now got much +better, much more + +realistically-looking results. + +And we also will look at the +stresses using the stress + +vector plots again, in the +elements, that show us also + +that the results are now quite +realistic and that our mesh, + +including the boundary +conditions have been quite + +properly defined. + +So let us now look at this +step of the analysis. + +The command runadina +calls ADINA to + +execute the input data. + +The data input file is +in ADINA-IN F02. + +And here, we see now the +deformed plotted onto the + +original mesh. + +The original mesh is plotted +in dash lines. + +Of course, the deformations +are magnified. + +Note that as expected, the top +face has uniformly moved up. + +However, note that the nodal +points on the horizontal + +symmetry line have not +displaced at all. + +This is quite unphysical and +shows that the wrong boundary + +conditions have been used. + +If we look at the stress vector +plot over the mesh, the + +same conclusion is reached. + +For clarity, on the video, we +show here the stress vectors + +just on the elements closest +to the hole. + +And we can see in the element +adjoining the horizontal + +symmetry line, a stress that +acts normal to the whole. + +This is, of course, +unphysical. + +Next, we show the stress vectors +in the outer most + +elements of the quarter plate. + +And you can see here, a stress +acting perpendicular to the + +free edge of the plate, when +we look near the horizontal + +symmetry line. + +This is also unphysical and is +due to having specified the + +wrong boundary conditions +on the wrong + +horizontal symmetry line. + +The specification +of the boundary + +conditions is shown here. + +The character, C, denotes the +boundary condition on the + +horizontal symmetry line. + +The character B denotes the +boundary condition on the + +vertical symmetry line. + +Where B means only the z +displacement is free and C + +means all displacements +are fixed. + +For the six possible +displacements and + +[? flotatations, ?] + +a 1 means the degree of freedom +is fixed, and 0 means + +the degree of freedom is free. + +We now correct the boundary +conditions. + +And B on the horizontal symmetry +line means now the v + +displacement is free. + +C on the vertical symmetry +line means now the w + +displacement is free. + +We run ADINA again, and here +you see the deformed mesh + +plotted on the original mesh. + +The deformations look +very reasonable. + +The plate has contracted +horizontally, and + +correspondingly, the hole +has shrunk horizontally. + +The deformations closest to +the hole are shown here. + +And here, we see the +stress vector + +plots for these elements. + +The stresses align nicely +with the hole. + +Notice that there is no stress +perpendicular to the free + +surface of the hole when we look +at the integration point + +layer closest as a hole. + +The value of the maximum +stress is given here. + +It is 301.9 megapascal. + +Here, we look at the element +which carries the largest + +stress, element 57. + +Once again, we can see that +the stresses align + +nicely with the hole. + +We now recall is that the +objective of our analysis is + +really the calculation of the +stress concentration factor. + +And if we look at the problem +once more, here, we have the + +plate with the hole. + +The plate subjected to the +tractions, as shown here. + +We now need to, of course, +predict the stresses + +accurately around the hole, +and in particular, at this + +point here. + +Here, we have our +finite element + +method used in the analysis. + +And so far, the only calculated +stresses at the + +integration points +in the elements. + +Now this is here, by the +way, element number 57. + +And for this element, we have +calculated so far, only the + +stresses at these integration +points. + +However, these integration +points do not lie on the + +circumference of the hole, on +the boundary of the hole. + +And that is where the maximum +stresses occur. + +Of particular interest is, of +course, also this point here, + +where we anticipate to +obtain the maximum + +stress in the analysis. + +If you look at, schematically, +how the stresses would vary, + +say, through the element, to the +boundary of the hole, we + +would see a schematic +plot as shown here. + +Here is an actual element, the +other elements lie next to it, + +and here you can see +schematically shown the stress + +computed at the closest +integration point to the + +boundary of the hole. + +And here, we would have +the stress computed + +at the nodal point. + +That is actually the stress +that we are interested in. + +Well, we can ask ADINA to +calculate the stresses at the + +nodal points, and then we can +ask ADINA-PLOT to enter with + +these nodal point stresses +into this formula here. + +Sigma yy, sigma zz, and sigma +yz are the stresses at the + +nodal points. + +To calculate, ADINA-PLOT +calculate this Sigma 1, which + +is the maximum principle of +stress at that nodal point. + +We can ask ADINA-PLOT to +calculate sigma 1 at all the + +nodal points in the mesh, and by +doing so, we obtained these + +stresses and then they can ask +ADINA-PLOT to search through + +those nodal points stresses, +these sigma 1 stresses, to + +find us the location, the +element and the nodal point, + +to have the physical location +of the maximum stress + +occurring in the mesh. + +We will see that doing so, +ADINA-PLOT comes up to tell us + +that this is the point, element +number 57, point + +number 4, that is this physical +point here, where the + +maximum stress occurs and will +also give us that maximum + +stress, and that maximum stress, +of course, gives us + +then the stress concentration +factor. + +So let us now look at this +phase of the analysis. + +Here, we have input some +information regarding + +variables that need be defined +in ADINA plot. + +TYY refers to tau yy, TZZ +refers to tau zz, TYZ + +refers to tau yz. + +We define the result and +variable to calculate the + +maximum principle stress. + +Hence, when TYY, TZZ, and TYZ +are defined [? smax ?] + +gives the maximum principle +stress. + +Here, we now enter the command +to look for the maximum + +principal stress in the mesh. + +First we make a small input +error, obtain a message, we + +correct the input, and here +comes the result. + +We see that indeed element +57.4 carries a maximum + +principle stress and this value +is 345.151 megapascal. + +We have now actually obtained +an answer to the + +question that we asked. + +Originally, namely, we wanted +to calculated the stress + +concentration factor +around the hole. + +And we have obtained a number +for that stress + +concentration factor. + +However, a valid question, +certainly is to ask, how good + +is this number? + +After all, we used a finite +element mesh to approximate + +the plate a particular finite +element idealization was used, + +and we have only obtained +an approximation + +to the exact result. + +Well, to evaluate that question, +to obtain insight + +into that question, to evaluate +how good our analysis + +results really are, we can plot +stress jumps, the way we + +discussed it in an +earlier lecture. + +And in particular, for the +analysis that I'd like to show + +you in this final phase, we +have plotted stress jumps + +along these two lines. + +Now, notice that, for example, +at this node here, we have + +four elements coupling into this +node, so at this node we + +get four different stress +predictions + +for each stress component. + +At this node here, we would +have only two stress + +predictions, for each stress +component because only two + +elements couple into +this node. + +That is one way to evaluate or +to look at how accurate our + +results are. + +An alternative way is to plot +pressure bands, and the + +pressure here is scalar. + +It's computed as shown here, +and we can plot bands of + +constant pressure, the way we +already have discussed it in + +an earlier lecture. + +Notice because this is a scalar, +it can be used very + +nicely to plot these bands +of constant pressure. + +Of course, we could also have +used here, say, an effective + +stress, which is also a scalar, +and we could plot + +bands of constant effective +stresses. + +One example that you've seen +already early, is this one + +here where we plotted pressure +bands, with band magnitude of + +5 MPa, megapascal, and you can +see here this white band, here + +a black band, in other words, +we're going in steps 5 MPa + +from one band to the next. + +Notice that there's a pressure +band discontinuity right here, + +which already indicates that we +have a stress discontinuity + +here, and which indicates that +the mesh that we used is + +really not a very fine mesh. + +And if we are interested in +obtaining a very accurate + +result, then based on these +pressure band plots, and also + +the stress jump plots that I +will show you just now, we may + +actually decide to +use a finer mesh. + +We discussed this issue already +in an earlier lecture. + +So let us now then look at what +happens, or what happened + +in this final phase +of the analysis. + +Let's go back to the laboratory +and share the + +experiences that we'll +see there. + +Here, we see once more +the mesh we're + +using in the analysis. + +We will plot the stresses, and +hence, we can see the stress + +jumps along the horizontal +symmetry line, and the + +diagonal line of the plate. + +Here, you see the stresses along +the horizontal symmetry + +line, Tau zz is plotted. + +The horizontal axis measures +distance along + +the symmetry line. + +And the vertical axis measures +the stress values. + +Note that the stress predictions +at the nodes, when + +calculated for the different +elements are almost the same. + +Only at one node can we actually +see a difference, and + +it is quite small. + +Note that two elements couple +into this node. + +Hence, there are only small +stress jumps along the + +horizontal symmetry +axis of the plate. + +Next, we look at the stress plot +along the diagonal line + +of the model. + +Here the maximum principle +stress is plotted. + +Note that at one node into which +four elements couple, we + +have four markedly different +stress values. + +Indeed, we have significant +stress jumps at that node, but + +otherwise the stress +predictions do + +not show large jumps. + +Finally, we look at the +pressure band plots. + +Here, they are drawn. + +To save time, we skipped some +of the drawing process and + +jumped to a later +picture here. + +We notice that the pressure +bands are quite continuous, + +except between the first and +second layer of elements + +around the hole. + +This corresponds to the stress +discontinuity between these + +element layers that +we saw earlier. + +We see now this is now +completed, I'd like to look + +with you once more back on to +two view graphs that we + +already have looked +at earlier. + +On this you graph, we summarize +some important + +observations. + +And we said that it is very +important to check the finite + +element data input carefully +prior to the actual response + +solution run. + +That, of course, means +plotting the data. + +And we have done so, of course, +in our analysis. + +And after the response solution +has been obtained, by + +starting whether desired +boundary conditions are + +satisfied, whether displacement +and stress + +solution is reasonable. + +Remember, in our analysis, we +did this, of course, as well + +and we found, by looking at the +boundary conditions, the + +way they were represented in the +actual solution, that we + +have actually made an error. + +In other words, we looked at +the deformed mesh, and the + +boundary conditions on the +deformed mesh in our first + +analysis showed that we had +fixed the boundary at the + +bottom off the mesh, +which was an error. + +So it is very important to go +through this step, to look + +very closely whether the +boundary conditions are + +actually satisfied on the mesh +that you have been using, in + +the right way. + +Of course, the same holds for +the stress and solution. + +Remember, that we looked at the +stress plots for the mesh + +that was fixed at the bottom +and we could directly see + +there were errors there, and, +in other words, the error of + +having fixed the boundary at +the bottom of the plate. + +So this step is most important, +and we have seen an + +example in the analysis that +we just completed. + +I also had this view graph +already on, where we said that + +we want to carefully evaluate +and interpret + +the calculated response. + +We want to study, in detail, +the calculated displacement + +and stresses along certain +lines, study stress jumps. + +Well, we saw an example of that +in the analysis that we + +just completed, and we also +pointed out that it is + +important to go through this +step here first, prior to + +using a stress averaging because +if you do average + +stresses, of course, you would +never see stress jumps. + +And this can be an important +step to gain confidence in the + +analysis results that +you have obtained. + +This then completes what I +wanted to share with you in + +this lecture. + +Thank you very much for +your attention. \ No newline at end of file diff --git a/KO6GiBAK7cY.txt b/KO6GiBAK7cY.txt new file mode 100644 index 0000000000000000000000000000000000000000..8e9368f676396bfba3a6af3b15c3e888ac4d599e --- /dev/null +++ b/KO6GiBAK7cY.txt @@ -0,0 +1,163 @@ +align:start position:0% + +so my perspectives about language have + + align:start position:0% +so my perspectives about language have + + + align:start position:0% +so my perspectives about language have +changed significantly over the course of + + align:start position:0% +changed significantly over the course of + + + align:start position:0% +changed significantly over the course of +this class I think in awakening me and + + align:start position:0% +this class I think in awakening me and + + + align:start position:0% +this class I think in awakening me and +making me acknowledge biases and + + align:start position:0% +making me acknowledge biases and + + + align:start position:0% +making me acknowledge biases and +perceptions that I had and trying to + + align:start position:0% +perceptions that I had and trying to + + + align:start position:0% +perceptions that I had and trying to +recognize that all languages are equal + + align:start position:0% +recognize that all languages are equal + + + align:start position:0% +recognize that all languages are equal +you know in thinking about other aspects + + align:start position:0% +you know in thinking about other aspects + + + align:start position:0% +you know in thinking about other aspects +of my life where like you know wanting + + align:start position:0% +of my life where like you know wanting + + + align:start position:0% +of my life where like you know wanting +as like a minority woman of color like + + align:start position:0% +as like a minority woman of color like + + + align:start position:0% +as like a minority woman of color like +thinking of equality in that terms that + + align:start position:0% +thinking of equality in that terms that + + + align:start position:0% +thinking of equality in that terms that +I never thought to apply it to language + + align:start position:0% +I never thought to apply it to language + + + align:start position:0% +I never thought to apply it to language +and I never really considered how + + align:start position:0% +and I never really considered how + + + align:start position:0% +and I never really considered how +important languages as far as like + + align:start position:0% +important languages as far as like + + + align:start position:0% +important languages as far as like +identity and you know we learned a lot + + align:start position:0% +identity and you know we learned a lot + + + align:start position:0% +identity and you know we learned a lot +about how in this class like language is + + align:start position:0% +about how in this class like language is + + + align:start position:0% +about how in this class like language is +not just like their political social and + + align:start position:0% +not just like their political social and + + + align:start position:0% +not just like their political social and +economic implications and so I feel like + + align:start position:0% +economic implications and so I feel like + + + align:start position:0% +economic implications and so I feel like +this class has changed my perspective + + align:start position:0% +this class has changed my perspective + + + align:start position:0% +this class has changed my perspective +and making me aware of those things and + + align:start position:0% +and making me aware of those things and + + + align:start position:0% +and making me aware of those things and +realizing that language is important and + + align:start position:0% +realizing that language is important and + + + align:start position:0% +realizing that language is important and +that idea that all languages are equal \ No newline at end of file diff --git a/KUVB9S0QX-I.txt b/KUVB9S0QX-I.txt new file mode 100644 index 0000000000000000000000000000000000000000..55a32f0294e6c42c0747daa1d17955177d56ab82 --- /dev/null +++ b/KUVB9S0QX-I.txt @@ -0,0 +1,7520 @@ +align:start position:0% + +the following content is provided by MIT + + align:start position:0% +the following content is provided by MIT + + + align:start position:0% +the following content is provided by MIT +open courseware under a Creative Commons + + align:start position:0% +open courseware under a Creative Commons + + + align:start position:0% +open courseware under a Creative Commons +license additional information about our + + align:start position:0% +license additional information about our + + + align:start position:0% +license additional information about our +license and MIT open courseware in + + align:start position:0% +license and MIT open courseware in + + + align:start position:0% +license and MIT open courseware in +general is available at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu last time we saw that these + + align:start position:0% +ocw.mit.edu last time we saw that these + + + align:start position:0% +ocw.mit.edu last time we saw that these +electron configurations that you've been + + align:start position:0% +electron configurations that you've been + + + align:start position:0% +electron configurations that you've been +writing down are + + align:start position:0% +writing down are + + + align:start position:0% +writing down are +uh nothing other than a shorthand way of + + align:start position:0% +uh nothing other than a shorthand way of + + + align:start position:0% +uh nothing other than a shorthand way of +writing down the wave functions + + align:start position:0% +writing down the wave functions + + + align:start position:0% +writing down the wave functions +for each electron in a multi-electron + + align:start position:0% +for each electron in a multi-electron + + + align:start position:0% +for each electron in a multi-electron +atom within the one electron wave + + align:start position:0% +atom within the one electron wave + + + align:start position:0% +atom within the one electron wave +approximation where we let every + + align:start position:0% +approximation where we let every + + + align:start position:0% +approximation where we let every +electron in the system or in the atom + + align:start position:0% +electron in the system or in the atom + + + align:start position:0% +electron in the system or in the atom +have its own wave + + align:start position:0% +have its own wave + + + align:start position:0% +have its own wave +function and as an approximation we gave + + align:start position:0% +function and as an approximation we gave + + + align:start position:0% +function and as an approximation we gave +it a hydrogen atom wave + + align:start position:0% +it a hydrogen atom wave + + + align:start position:0% +it a hydrogen atom wave +function but we also saw that we did not + + align:start position:0% +function but we also saw that we did not + + + align:start position:0% +function but we also saw that we did not +that at most we gave two electrons + + align:start position:0% +that at most we gave two electrons + + + align:start position:0% +that at most we gave two electrons +hydrogen atom wave function the same + + align:start position:0% +hydrogen atom wave function the same + + + align:start position:0% +hydrogen atom wave function the same +hydrogen atom wave + + align:start position:0% +hydrogen atom wave + + + align:start position:0% +hydrogen atom wave +function and of course you already know + + align:start position:0% +function and of course you already know + + + align:start position:0% +function and of course you already know +that the reason we did that is because + + align:start position:0% +that the reason we did that is because + + + align:start position:0% +that the reason we did that is because +of this quantum mechanical concept + + align:start position:0% +of this quantum mechanical concept + + + align:start position:0% +of this quantum mechanical concept +called spin quantum mechanical + + align:start position:0% +called spin quantum mechanical + + + align:start position:0% +called spin quantum mechanical +phenomenon called + + align:start position:0% +phenomenon called + + + align:start position:0% +phenomenon called +spin spin is the intrinsic angular + + align:start position:0% +spin spin is the intrinsic angular + + + align:start position:0% +spin spin is the intrinsic angular +momentum it is the angular momentum + + align:start position:0% +momentum it is the angular momentum + + + align:start position:0% +momentum it is the angular momentum +built in to the + + align:start position:0% +built in to the + + + align:start position:0% +built in to the +particle and then angular momentum comes + + align:start position:0% +particle and then angular momentum comes + + + align:start position:0% +particle and then angular momentum comes +in sort of two polarities a spin up and + + align:start position:0% +in sort of two polarities a spin up and + + + align:start position:0% +in sort of two polarities a spin up and +a spin + + align:start position:0% +a spin + + + align:start position:0% +a spin +down corresponding to the two possible + + align:start position:0% +down corresponding to the two possible + + + align:start position:0% +down corresponding to the two possible +values of the spin quantum number M Subs + + align:start position:0% +values of the spin quantum number M Subs + + + align:start position:0% +values of the spin quantum number M Subs +that we looked at last time M Subs can + + align:start position:0% +that we looked at last time M Subs can + + + align:start position:0% +that we looked at last time M Subs can +have the value plus2 or can have the + + align:start position:0% +have the value plus2 or can have the + + + align:start position:0% +have the value plus2 or can have the +value minus + + align:start position:0% + + + + align:start position:0% + +one2 all right so um we're about to talk + + align:start position:0% +one2 all right so um we're about to talk + + + align:start position:0% +one2 all right so um we're about to talk +about + + align:start position:0% +about + + + align:start position:0% +about +how spin was actually + + align:start position:0% +how spin was actually + + + align:start position:0% +how spin was actually +discovered and um was + + align:start position:0% +discovered and um was + + + align:start position:0% +discovered and um was +discovered by these two gentlemen here + + align:start position:0% +discovered by these two gentlemen here + + + align:start position:0% +discovered by these two gentlemen here +George umbeck and Sam hmid and they were + + align:start position:0% +George umbeck and Sam hmid and they were + + + align:start position:0% +George umbeck and Sam hmid and they were +uh really very young scientists they + + align:start position:0% +uh really very young scientists they + + + align:start position:0% +uh really very young scientists they +might have been post dos at the time and + + align:start position:0% +might have been post dos at the time and + + + align:start position:0% +might have been post dos at the time and +what they were looking at was the + + align:start position:0% +what they were looking at was the + + + align:start position:0% +what they were looking at was the +emission Spectra from uh sodium + + align:start position:0% +emission Spectra from uh sodium + + + align:start position:0% +emission Spectra from uh sodium +atoms and this is + + align:start position:0% +atoms and this is + + + align:start position:0% +atoms and this is +1925 and so they already knew + + align:start position:0% +1925 and so they already knew + + + align:start position:0% +1925 and so they already knew +enough about the electronics structure + + align:start position:0% +enough about the electronics structure + + + align:start position:0% +enough about the electronics structure +to anticipate where the the emission to + + align:start position:0% +to anticipate where the the emission to + + + align:start position:0% +to anticipate where the the emission to +anticipate at what frequency they ought + + align:start position:0% +anticipate at what frequency they ought + + + align:start position:0% +anticipate at what frequency they ought +to see emission from the sodium + + align:start position:0% +to see emission from the sodium + + + align:start position:0% +to see emission from the sodium +atoms and so they got a discharge going + + align:start position:0% +atoms and so they got a discharge going + + + align:start position:0% +atoms and so they got a discharge going +looked at the emission dispersed it and + + align:start position:0% +looked at the emission dispersed it and + + + align:start position:0% +looked at the emission dispersed it and +well they thought that they would see + + align:start position:0% +well they thought that they would see + + + align:start position:0% +well they thought that they would see +some emission at this particular + + align:start position:0% +some emission at this particular + + + align:start position:0% +some emission at this particular +frequency but instead what they saw was + + align:start position:0% +frequency but instead what they saw was + + + align:start position:0% +frequency but instead what they saw was +some + + align:start position:0% +some + + + align:start position:0% +some +emission a little bit lower in frequency + + align:start position:0% +emission a little bit lower in frequency + + + align:start position:0% +emission a little bit lower in frequency +were they expected and a little bit + + align:start position:0% +were they expected and a little bit + + + align:start position:0% +were they expected and a little bit +higher in energy than what they expected + + align:start position:0% +higher in energy than what they expected + + + align:start position:0% +higher in energy than what they expected +in spectroscopy this kind of emission + + align:start position:0% +in spectroscopy this kind of emission + + + align:start position:0% +in spectroscopy this kind of emission +here is called a + + align:start position:0% +here is called a + + + align:start position:0% +here is called a +doublet okay a little lower and a little + + align:start position:0% +doublet okay a little lower and a little + + + align:start position:0% +doublet okay a little lower and a little +higher well they uh looked at these + + align:start position:0% +higher well they uh looked at these + + + align:start position:0% +higher well they uh looked at these +results thought about it and said you + + align:start position:0% +results thought about it and said you + + + align:start position:0% +results thought about it and said you +know I think we can understand that + + align:start position:0% +know I think we can understand that + + + align:start position:0% +know I think we can understand that +those two lines those Missions at the + + align:start position:0% +those two lines those Missions at the + + + align:start position:0% +those two lines those Missions at the +two frequencies there if the electron in + + align:start position:0% +two frequencies there if the electron in + + + align:start position:0% +two frequencies there if the electron in +particular that extra s electron in the + + align:start position:0% +particular that extra s electron in the + + + align:start position:0% +particular that extra s electron in the +sodium if that existed in one of two + + align:start position:0% +sodium if that existed in one of two + + + align:start position:0% +sodium if that existed in one of two +spin + + align:start position:0% +spin + + + align:start position:0% +spin +States so this was revolutionary idea + + align:start position:0% +States so this was revolutionary idea + + + align:start position:0% +States so this was revolutionary idea +and uh so they were quite excited about + + align:start position:0% +and uh so they were quite excited about + + + align:start position:0% +and uh so they were quite excited about +it and they took the results of their + + align:start position:0% +it and they took the results of their + + + align:start position:0% +it and they took the results of their +experiment and their interpretation to + + align:start position:0% +experiment and their interpretation to + + + align:start position:0% +experiment and their interpretation to +the resident established scientist at + + align:start position:0% +the resident established scientist at + + + align:start position:0% +the resident established scientist at +the time that was closest to them this + + align:start position:0% +the time that was closest to them this + + + align:start position:0% +the time that was closest to them this +guy Wolf Gang + + align:start position:0% +guy Wolf Gang + + + align:start position:0% +guy Wolf Gang +poy Wolf Gang poy was not a nice + + align:start position:0% + + + + align:start position:0% + +man so they showed him the data and they + + align:start position:0% +man so they showed him the data and they + + + align:start position:0% +man so they showed him the data and they +said oh yeah this this makes sense if + + align:start position:0% +said oh yeah this this makes sense if + + + align:start position:0% +said oh yeah this this makes sense if +the electrons in two different spin + + align:start position:0% +the electrons in two different spin + + + align:start position:0% +the electrons in two different spin +States and Wolf Gang poy said rubbish + + align:start position:0% +States and Wolf Gang poy said rubbish + + + align:start position:0% +States and Wolf Gang poy said rubbish +you publish that and you'll wreck your + + align:start position:0% +you publish that and you'll wreck your + + + align:start position:0% +you publish that and you'll wreck your +young Scientific + + align:start position:0% +young Scientific + + + align:start position:0% +young Scientific +careers so hoen Beck and ho left + + align:start position:0% +careers so hoen Beck and ho left + + + align:start position:0% +careers so hoen Beck and ho left +dejectedly no sooner than the door + + align:start position:0% +dejectedly no sooner than the door + + + align:start position:0% +dejectedly no sooner than the door +slamed shut and poie sits down and he + + align:start position:0% +slamed shut and poie sits down and he + + + align:start position:0% +slamed shut and poie sits down and he +writes a paper on the presence of the + + align:start position:0% +writes a paper on the presence of the + + + align:start position:0% +writes a paper on the presence of the +fourth quantum number M + + align:start position:0% +fourth quantum number M + + + align:start position:0% +fourth quantum number M +Subs this is one of the best well-known + + align:start position:0% +Subs this is one of the best well-known + + + align:start position:0% +Subs this is one of the best well-known +travesties in the history of science now + + align:start position:0% +travesties in the history of science now + + + align:start position:0% +travesties in the history of science now +well known + + align:start position:0% +well known + + + align:start position:0% +well known +okay and + + align:start position:0% +okay and + + + align:start position:0% +okay and +it and it actually took however another + + align:start position:0% +it and it actually took however another + + + align:start position:0% +it and it actually took however another +three years and it took another + + align:start position:0% +three years and it took another + + + align:start position:0% +three years and it took another +gentleman to rock + + align:start position:0% +gentleman to rock + + + align:start position:0% +gentleman to rock +uh it was dck who actually wrote down + + align:start position:0% +uh it was dck who actually wrote down + + + align:start position:0% +uh it was dck who actually wrote down +the relativistic schinger equation and + + align:start position:0% +the relativistic schinger equation and + + + align:start position:0% +the relativistic schinger equation and +solved it and when you do that out drops + + align:start position:0% +solved it and when you do that out drops + + + align:start position:0% +solved it and when you do that out drops +this fourth quantum number M Subs + + align:start position:0% +this fourth quantum number M Subs + + + align:start position:0% +this fourth quantum number M Subs +okay however poy did uh did contribute + + align:start position:0% +okay however poy did uh did contribute + + + align:start position:0% +okay however poy did uh did contribute +uh to this problem in the sense that uh + + align:start position:0% +uh to this problem in the sense that uh + + + align:start position:0% +uh to this problem in the sense that uh +he he worked on um the principles uh + + align:start position:0% +he he worked on um the principles uh + + + align:start position:0% +he he worked on um the principles uh +behind uh these problems with electrons + + align:start position:0% +behind uh these problems with electrons + + + align:start position:0% +behind uh these problems with electrons +being F Fons Etc which we won't go into + + align:start position:0% +being F Fons Etc which we won't go into + + + align:start position:0% +being F Fons Etc which we won't go into +but out of that work came something + + align:start position:0% +but out of that work came something + + + align:start position:0% +but out of that work came something +called this the poy Exclusion Principle + + align:start position:0% +called this the poy Exclusion Principle + + + align:start position:0% +called this the poy Exclusion Principle +right and the essence of that principle + + align:start position:0% +right and the essence of that principle + + + align:start position:0% +right and the essence of that principle +is that um no two electrons in the same + + align:start position:0% +is that um no two electrons in the same + + + align:start position:0% +is that um no two electrons in the same +atom can have the same electron wave + + align:start position:0% +atom can have the same electron wave + + + align:start position:0% +atom can have the same electron wave +function or the same and the same spin + + align:start position:0% +function or the same and the same spin + + + align:start position:0% +function or the same and the same spin +or another way to say that no two + + align:start position:0% +or another way to say that no two + + + align:start position:0% +or another way to say that no two +electrons can have the same set of four + + align:start position:0% +electrons can have the same set of four + + + align:start position:0% +electrons can have the same set of four +quantum numbers + + align:start position:0% +quantum numbers + + + align:start position:0% +quantum numbers +okay so for example in our electron + + align:start position:0% +okay so for example in our electron + + + align:start position:0% +okay so for example in our electron +configuration here of + + align:start position:0% +configuration here of + + + align:start position:0% +configuration here of +neon this electron has the quantum + + align:start position:0% +neon this electron has the quantum + + + align:start position:0% +neon this electron has the quantum +numbers 1 0 plus 12 for M Subs this + + align:start position:0% +numbers 1 0 plus 12 for M Subs this + + + align:start position:0% +numbers 1 0 plus 12 for M Subs this +electron has the quantum numbers 1 Z 0 + + align:start position:0% +electron has the quantum numbers 1 Z 0 + + + align:start position:0% +electron has the quantum numbers 1 Z 0 +minus 12 for M Subs so these two + + align:start position:0% +minus 12 for M Subs so these two + + + align:start position:0% +minus 12 for M Subs so these two +electrons don't have the same set of + + align:start position:0% +electrons don't have the same set of + + + align:start position:0% +electrons don't have the same set of +four quantum numbers right and that's + + align:start position:0% +four quantum numbers right and that's + + + align:start position:0% +four quantum numbers right and that's +why we could only put two electrons here + + align:start position:0% +why we could only put two electrons here + + + align:start position:0% +why we could only put two electrons here +in this 1 s state + + align:start position:0% +in this 1 s state + + + align:start position:0% +in this 1 s state +okay likewise this uh electron here has + + align:start position:0% +okay likewise this uh electron here has + + + align:start position:0% +okay likewise this uh electron here has +the quantum numbers 2 1 minus one + + align:start position:0% +the quantum numbers 2 1 minus one + + + align:start position:0% +the quantum numbers 2 1 minus one ++2 this electron has the quantum numbers + + align:start position:0% ++2 this electron has the quantum numbers + + + align:start position:0% ++2 this electron has the quantum numbers +2 1 - one + + align:start position:0% +2 1 - one + + + align:start position:0% +2 1 - one +-2 okay so that's the PO Exclusion + + align:start position:0% +-2 okay so that's the PO Exclusion + + + align:start position:0% +-2 okay so that's the PO Exclusion +Principle which prevents us from putting + + align:start position:0% +Principle which prevents us from putting + + + align:start position:0% +Principle which prevents us from putting +more than two electrons in each one of + + align:start position:0% +more than two electrons in each one of + + + align:start position:0% +more than two electrons in each one of +these states 2 S 2 S 2 PX 2 pz or 2 py + + align:start position:0% +these states 2 S 2 S 2 PX 2 pz or 2 py + + + align:start position:0% +these states 2 S 2 S 2 PX 2 pz or 2 py +okay + + align:start position:0% +okay + + + align:start position:0% +okay +okay so um now what I want to do is I + + align:start position:0% +okay so um now what I want to do is I + + + align:start position:0% +okay so um now what I want to do is I +want to try to look at the wave + + align:start position:0% +want to try to look at the wave + + + align:start position:0% +want to try to look at the wave +functions I want to look at uh what + + align:start position:0% +functions I want to look at uh what + + + align:start position:0% +functions I want to look at uh what +these wave functions look like for the + + align:start position:0% +these wave functions look like for the + + + align:start position:0% +these wave functions look like for the +electrons in the multi-electron atom and + + align:start position:0% +electrons in the multi-electron atom and + + + align:start position:0% +electrons in the multi-electron atom and +to look at their shapes what we're going + + align:start position:0% +to look at their shapes what we're going + + + align:start position:0% +to look at their shapes what we're going +to do is we're going to look at the + + align:start position:0% +to do is we're going to look at the + + + align:start position:0% +to do is we're going to look at the +radial probability distribution function + + align:start position:0% +radial probability distribution function + + + align:start position:0% +radial probability distribution function +because remember what the radial + + align:start position:0% +because remember what the radial + + + align:start position:0% +because remember what the radial +probability distribution function tells + + align:start position:0% +probability distribution function tells + + + align:start position:0% +probability distribution function tells +us it tells + + align:start position:0% +us it tells + + + align:start position:0% +us it tells +us the probability of finding the + + align:start position:0% +us the probability of finding the + + + align:start position:0% +us the probability of finding the +electron between R and R plus + + align:start position:0% +electron between R and R plus + + + align:start position:0% +electron between R and R plus +Dr okay so I plotted those radial + + align:start position:0% +Dr okay so I plotted those radial + + + align:start position:0% +Dr okay so I plotted those radial +probability distribution functions + + align:start position:0% +probability distribution functions + + + align:start position:0% +probability distribution functions +versus + + align:start position:0% +versus + + + align:start position:0% +versus +R for each one of the electrons in the + + align:start position:0% +R for each one of the electrons in the + + + align:start position:0% +R for each one of the electrons in the +different states for this multi-electron + + align:start position:0% +different states for this multi-electron + + + align:start position:0% +different states for this multi-electron +atom argon okay + + align:start position:0% +atom argon okay + + + align:start position:0% +atom argon okay +and what we want to do is we want to + + align:start position:0% +and what we want to do is we want to + + + align:start position:0% +and what we want to do is we want to +compare and contrast these wave + + align:start position:0% +compare and contrast these wave + + + align:start position:0% +compare and contrast these wave +functions for the individual electrons + + align:start position:0% +functions for the individual electrons + + + align:start position:0% +functions for the individual electrons +in this multi- electron atom to those of + + align:start position:0% +in this multi- electron atom to those of + + + align:start position:0% +in this multi- electron atom to those of +hydrogen all right all right well first + + align:start position:0% +hydrogen all right all right well first + + + align:start position:0% +hydrogen all right all right well first +the + + align:start position:0% +the + + + align:start position:0% +the +similarities if you look at this wave + + align:start position:0% +similarities if you look at this wave + + + align:start position:0% +similarities if you look at this wave +function or if you look at the radial + + align:start position:0% +function or if you look at the radial + + + align:start position:0% +function or if you look at the radial +probability distribution for the 1s wave + + align:start position:0% +probability distribution for the 1s wave + + + align:start position:0% +probability distribution for the 1s wave +function here what you see is that that + + align:start position:0% +function here what you see is that that + + + align:start position:0% +function here what you see is that that +radial probability distribution is zero + + align:start position:0% +radial probability distribution is zero + + + align:start position:0% +radial probability distribution is zero +at R equals z as all radial probabil + + align:start position:0% +at R equals z as all radial probabil + + + align:start position:0% +at R equals z as all radial probabil +ility distributions are that's not a + + align:start position:0% +ility distributions are that's not a + + + align:start position:0% +ility distributions are that's not a +radial node that probability + + align:start position:0% +radial node that probability + + + align:start position:0% +radial node that probability +distribution increases goes to a maximum + + align:start position:0% +distribution increases goes to a maximum + + + align:start position:0% +distribution increases goes to a maximum +and then decays exponentially with r hey + + align:start position:0% +and then decays exponentially with r hey + + + align:start position:0% +and then decays exponentially with r hey +that's exactly what a 1 s wave function + + align:start position:0% +that's exactly what a 1 s wave function + + + align:start position:0% +that's exactly what a 1 s wave function +looks like for a hydrogen + + align:start position:0% +looks like for a hydrogen + + + align:start position:0% +looks like for a hydrogen +atom if you looked at the 2s W function + + align:start position:0% +atom if you looked at the 2s W function + + + align:start position:0% +atom if you looked at the 2s W function +it starts at R equals 0 goes up a bit + + align:start position:0% +it starts at R equals 0 goes up a bit + + + align:start position:0% +it starts at R equals 0 goes up a bit +and then goes to zero here's a radial + + align:start position:0% +and then goes to zero here's a radial + + + align:start position:0% +and then goes to zero here's a radial +node in the 2s W function and then goes + + align:start position:0% +node in the 2s W function and then goes + + + align:start position:0% +node in the 2s W function and then goes +back up here's the most here's the most + + align:start position:0% +back up here's the most here's the most + + + align:start position:0% +back up here's the most here's the most +prob value of R then decays + + align:start position:0% +prob value of R then decays + + + align:start position:0% +prob value of R then decays +exponentially hey again it has the same + + align:start position:0% +exponentially hey again it has the same + + + align:start position:0% +exponentially hey again it has the same +structure as the 2s wave function in the + + align:start position:0% +structure as the 2s wave function in the + + + align:start position:0% +structure as the 2s wave function in the +hydrogen at so the similarity is that + + align:start position:0% +hydrogen at so the similarity is that + + + align:start position:0% +hydrogen at so the similarity is that +all of these wave functions have the + + align:start position:0% +all of these wave functions have the + + + align:start position:0% +all of these wave functions have the +same kind of basic structure as that in + + align:start position:0% +same kind of basic structure as that in + + + align:start position:0% +same kind of basic structure as that in +a hydrogen atom they have the same + + align:start position:0% +a hydrogen atom they have the same + + + align:start position:0% +a hydrogen atom they have the same +number of nodes same number of radial + + align:start position:0% +number of nodes same number of radial + + + align:start position:0% +number of nodes same number of radial +nodes same number of angular nodes all + + align:start position:0% +nodes same number of angular nodes all + + + align:start position:0% +nodes same number of angular nodes all +right the difference between these wave + + align:start position:0% +right the difference between these wave + + + align:start position:0% +right the difference between these wave +functions and those of the hydrogen atom + + align:start position:0% +functions and those of the hydrogen atom + + + align:start position:0% +functions and those of the hydrogen atom +is that all of these wave functions are + + align:start position:0% +is that all of these wave functions are + + + align:start position:0% +is that all of these wave functions are +closer in to the nucleus so for example + + align:start position:0% +closer in to the nucleus so for example + + + align:start position:0% +closer in to the nucleus so for example +if you looked here at what the most + + align:start position:0% +if you looked here at what the most + + + align:start position:0% +if you looked here at what the most +probable value of R is for that 1 s + + align:start position:0% +probable value of R is for that 1 s + + + align:start position:0% +probable value of R is for that 1 s +electron that most probable value in + + align:start position:0% +electron that most probable value in + + + align:start position:0% +electron that most probable value in +argon is .1 a knot what's the most + + align:start position:0% +argon is .1 a knot what's the most + + + align:start position:0% +argon is .1 a knot what's the most +probable value for R in the 1 s state of + + align:start position:0% +probable value for R in the 1 s state of + + + align:start position:0% +probable value for R in the 1 s state of +hydrogen a not this is 10 times closer + + align:start position:0% +hydrogen a not this is 10 times closer + + + align:start position:0% +hydrogen a not this is 10 times closer +closer all right this is much closer to + + align:start position:0% +closer all right this is much closer to + + + align:start position:0% +closer all right this is much closer to +the nucleus than it is in the hydrogen + + align:start position:0% +the nucleus than it is in the hydrogen + + + align:start position:0% +the nucleus than it is in the hydrogen +atom and if we went and we compared the + + align:start position:0% +atom and if we went and we compared the + + + align:start position:0% +atom and if we went and we compared the +most probable values for 2 s2p to those + + align:start position:0% +most probable values for 2 s2p to those + + + align:start position:0% +most probable values for 2 s2p to those +of hydrogen and 3 s3p for those of + + align:start position:0% +of hydrogen and 3 s3p for those of + + + align:start position:0% +of hydrogen and 3 s3p for those of +hydrogen we'd find that all of these are + + align:start position:0% +hydrogen we'd find that all of these are + + + align:start position:0% +hydrogen we'd find that all of these are +much closer in to the nucleus why + + align:start position:0% +much closer in to the nucleus why + + + align:start position:0% +much closer in to the nucleus why +because the nucleus has a + + align:start position:0% +because the nucleus has a + + + align:start position:0% +because the nucleus has a +larger uh positive charge on it right + + align:start position:0% +larger uh positive charge on it right + + + align:start position:0% +larger uh positive charge on it right +the coolant interaction here is the + + align:start position:0% +the coolant interaction here is the + + + align:start position:0% +the coolant interaction here is the +charge on the electron times the charge + + align:start position:0% +charge on the electron times the charge + + + align:start position:0% +charge on the electron times the charge +on the nucleus for Argon that charge is+ + + align:start position:0% +on the nucleus for Argon that charge is+ + + + align:start position:0% +on the nucleus for Argon that charge is+ +18 * e that greater attractive + + align:start position:0% +18 * e that greater attractive + + + align:start position:0% +18 * e that greater attractive +interaction pulls those electrons in + + align:start position:0% +interaction pulls those electrons in + + + align:start position:0% +interaction pulls those electrons in +closer to the nucleus that's the bottom + + align:start position:0% +closer to the nucleus that's the bottom + + + align:start position:0% +closer to the nucleus that's the bottom +line okay so that's how these differ the + + align:start position:0% +line okay so that's how these differ the + + + align:start position:0% +line okay so that's how these differ the +structures the same n structures the + + align:start position:0% +structures the same n structures the + + + align:start position:0% +structures the same n structures the +same they're just all closer into to the + + align:start position:0% +same they're just all closer into to the + + + align:start position:0% +same they're just all closer into to the +nucleus because of that greater + + align:start position:0% +nucleus because of that greater + + + align:start position:0% +nucleus because of that greater +attractive + + align:start position:0% + + + + align:start position:0% + +interaction okay so now that I have this + + align:start position:0% +interaction okay so now that I have this + + + align:start position:0% +interaction okay so now that I have this +radial probability distribution function + + align:start position:0% +radial probability distribution function + + + align:start position:0% +radial probability distribution function +up here I also want to use it to just + + align:start position:0% +up here I also want to use it to just + + + align:start position:0% +up here I also want to use it to just +illustrate a concept that I think you + + align:start position:0% +illustrate a concept that I think you + + + align:start position:0% +illustrate a concept that I think you +already know and that is this concept of + + align:start position:0% +already know and that is this concept of + + + align:start position:0% +already know and that is this concept of +a shell you know about the N equal one + + align:start position:0% +a shell you know about the N equal one + + + align:start position:0% +a shell you know about the N equal one +shell n equal 2 shell n equal 3 shell + + align:start position:0% +shell n equal 2 shell n equal 3 shell + + + align:start position:0% +shell n equal 2 shell n equal 3 shell +and the word shell also denotes kind + + align:start position:0% +and the word shell also denotes kind + + + align:start position:0% +and the word shell also denotes kind +some kind of spatial information right + + align:start position:0% +some kind of spatial information right + + + align:start position:0% +some kind of spatial information right +and when I and I want to show you how + + align:start position:0% +and when I and I want to show you how + + + align:start position:0% +and when I and I want to show you how +the spatial information is depicted here + + align:start position:0% +the spatial information is depicted here + + + align:start position:0% +the spatial information is depicted here +on this graph I want you to see that for + + align:start position:0% +on this graph I want you to see that for + + + align:start position:0% +on this graph I want you to see that for +the N equal three states 3s and + + align:start position:0% +the N equal three states 3s and + + + align:start position:0% +the N equal three states 3s and +3p well the most probable value isn't + + align:start position:0% +3p well the most probable value isn't + + + align:start position:0% +3p well the most probable value isn't +exactly in the same place but it's in + + align:start position:0% +exactly in the same place but it's in + + + align:start position:0% +exactly in the same place but it's in +the same place as when you compare it to + + align:start position:0% +the same place as when you compare it to + + + align:start position:0% +the same place as when you compare it to +the two s and the 2p right you can see + + align:start position:0% +the two s and the 2p right you can see + + + align:start position:0% +the two s and the 2p right you can see +how well the N equal 3 shell is + + align:start position:0% +how well the N equal 3 shell is + + + align:start position:0% +how well the N equal 3 shell is +separated in space from the N equal 2 + + align:start position:0% +separated in space from the N equal 2 + + + align:start position:0% +separated in space from the N equal 2 +shell again the most probable value for + + align:start position:0% +shell again the most probable value for + + + align:start position:0% +shell again the most probable value for +2s and 2p aren't exactly in the same + + align:start position:0% +2s and 2p aren't exactly in the same + + + align:start position:0% +2s and 2p aren't exactly in the same +place right we saw the 2p is actually a + + align:start position:0% +place right we saw the 2p is actually a + + + align:start position:0% +place right we saw the 2p is actually a +little closer than to 2s but in terms of + + align:start position:0% +little closer than to 2s but in terms of + + + align:start position:0% +little closer than to 2s but in terms of +comparing it to where the most probable + + align:start position:0% +comparing it to where the most probable + + + align:start position:0% +comparing it to where the most probable +values are for 3s and 3p hey that's much + + align:start position:0% +values are for 3s and 3p hey that's much + + + align:start position:0% +values are for 3s and 3p hey that's much +closer in all right and so this graph + + align:start position:0% +closer in all right and so this graph + + + align:start position:0% +closer in all right and so this graph +here it shows you it gives you an idea + + align:start position:0% +here it shows you it gives you an idea + + + align:start position:0% +here it shows you it gives you an idea +of the + + align:start position:0% +of the + + + align:start position:0% +of the +spatial information that is um denoted + + align:start position:0% +spatial information that is um denoted + + + align:start position:0% +spatial information that is um denoted +when we talk about shells the N equal 3 + + align:start position:0% +when we talk about shells the N equal 3 + + + align:start position:0% +when we talk about shells the N equal 3 +shell is further out the N equal 2 shell + + align:start position:0% +shell is further out the N equal 2 shell + + + align:start position:0% +shell is further out the N equal 2 shell +is closer in and the N equal one shell + + align:start position:0% +is closer in and the N equal one shell + + + align:start position:0% +is closer in and the N equal one shell +even closer in all right I think that's + + align:start position:0% +even closer in all right I think that's + + + align:start position:0% +even closer in all right I think that's +a concept that you mostly know but here + + align:start position:0% +a concept that you mostly know but here + + + align:start position:0% +a concept that you mostly know but here +you see it on the radial probability + + align:start position:0% + + + + align:start position:0% + +distribution + + align:start position:0% +distribution + + + align:start position:0% +distribution +okay so now we've uh taken a quick look + + align:start position:0% +okay so now we've uh taken a quick look + + + align:start position:0% +okay so now we've uh taken a quick look +at those wave + + align:start position:0% + + + + align:start position:0% + +functions now it's time to actually look + + align:start position:0% +functions now it's time to actually look + + + align:start position:0% +functions now it's time to actually look +at the energies of the + + align:start position:0% +at the energies of the + + + align:start position:0% +at the energies of the +states we haven't done that + + align:start position:0% +states we haven't done that + + + align:start position:0% +states we haven't done that +yet so on the left here I show an energy + + align:start position:0% +yet so on the left here I show an energy + + + align:start position:0% +yet so on the left here I show an energy +level diagram for the hydrogen atom + + align:start position:0% +level diagram for the hydrogen atom + + + align:start position:0% +level diagram for the hydrogen atom +right we saw this before here's the N + + align:start position:0% +right we saw this before here's the N + + + align:start position:0% +right we saw this before here's the N +equal one + + align:start position:0% +equal one + + + align:start position:0% +equal one +state here at n equal two we've got four + + align:start position:0% +state here at n equal two we've got four + + + align:start position:0% +state here at n equal two we've got four +states four degenerate States here at n + + align:start position:0% +states four degenerate States here at n + + + align:start position:0% +states four degenerate States here at n +equal 3 we got nine degenerate States + + align:start position:0% +equal 3 we got nine degenerate States + + + align:start position:0% +equal 3 we got nine degenerate States +here at n equal 4 we got 14 16 + + align:start position:0% +here at n equal 4 we got 14 16 + + + align:start position:0% +here at n equal 4 we got 14 16 +degenerate + + align:start position:0% +degenerate + + + align:start position:0% +degenerate +States okay but the difference between + + align:start position:0% +States okay but the difference between + + + align:start position:0% +States okay but the difference between +the hydrogen atom and any other + + align:start position:0% +the hydrogen atom and any other + + + align:start position:0% +the hydrogen atom and any other +multi-electron atom starting with helium + + align:start position:0% +multi-electron atom starting with helium + + + align:start position:0% +multi-electron atom starting with helium +two differences one is that the energies + + align:start position:0% +two differences one is that the energies + + + align:start position:0% +two differences one is that the energies +of these states in the multi-electron + + align:start position:0% +of these states in the multi-electron + + + align:start position:0% +of these states in the multi-electron +atom are all lower than they are in the + + align:start position:0% +atom are all lower than they are in the + + + align:start position:0% +atom are all lower than they are in the +hydrogen atom that is the one s State + + align:start position:0% +hydrogen atom that is the one s State + + + align:start position:0% +hydrogen atom that is the one s State +here is lower in energy than the 1s + + align:start position:0% +here is lower in energy than the 1s + + + align:start position:0% +here is lower in energy than the 1s +state in the hydrogen the 2s is lower + + align:start position:0% +state in the hydrogen the 2s is lower + + + align:start position:0% +state in the hydrogen the 2s is lower +than the 2s state in hydrogen the 3s is + + align:start position:0% +than the 2s state in hydrogen the 3s is + + + align:start position:0% +than the 2s state in hydrogen the 3s is +lower the 2p is lower the 3p is lower + + align:start position:0% +lower the 2p is lower the 3p is lower + + + align:start position:0% +lower the 2p is lower the 3p is lower +etc + + align:start position:0% +etc + + + align:start position:0% +etc +etc the energies of those states are all + + align:start position:0% +etc the energies of those states are all + + + align:start position:0% +etc the energies of those states are all +lower + + align:start position:0% +lower + + + align:start position:0% +lower +why because of the charge on the nucleus + + align:start position:0% +why because of the charge on the nucleus + + + align:start position:0% +why because of the charge on the nucleus +that potential energy of interaction is + + align:start position:0% +that potential energy of interaction is + + + align:start position:0% +that potential energy of interaction is +greater because the charge on the + + align:start position:0% +greater because the charge on the + + + align:start position:0% +greater because the charge on the +nucleus is + + align:start position:0% +nucleus is + + + align:start position:0% +nucleus is +larger that greater potential energy of + + align:start position:0% +larger that greater potential energy of + + + align:start position:0% +larger that greater potential energy of +interaction lowers the energy of the + + align:start position:0% +interaction lowers the energy of the + + + align:start position:0% +interaction lowers the energy of the +states makes those electrons more + + align:start position:0% +states makes those electrons more + + + align:start position:0% +states makes those electrons more +strongly bound so starting with helium + + align:start position:0% +strongly bound so starting with helium + + + align:start position:0% +strongly bound so starting with helium +all of these energies are lower than + + align:start position:0% +all of these energies are lower than + + + align:start position:0% +all of these energies are lower than +those in the hydrogen atom okay that's + + align:start position:0% +those in the hydrogen atom okay that's + + + align:start position:0% +those in the hydrogen atom okay that's +the first + + align:start position:0% +the first + + + align:start position:0% +the first +difference the second difference is you + + align:start position:0% +difference the second difference is you + + + align:start position:0% +difference the second difference is you +can see now that the 2s state is lower + + align:start position:0% +can see now that the 2s state is lower + + + align:start position:0% +can see now that the 2s state is lower +in energy than the 2p + + align:start position:0% +in energy than the 2p + + + align:start position:0% +in energy than the 2p +State the degeneracy between 2s and 2p + + align:start position:0% +State the degeneracy between 2s and 2p + + + align:start position:0% +State the degeneracy between 2s and 2p +in a hydrogen atom is lifted or is + + align:start position:0% +in a hydrogen atom is lifted or is + + + align:start position:0% +in a hydrogen atom is lifted or is +broken as we say likewise the 3s state + + align:start position:0% +broken as we say likewise the 3s state + + + align:start position:0% +broken as we say likewise the 3s state +is lower in energy than the 3p State + + align:start position:0% +is lower in energy than the 3p State + + + align:start position:0% +is lower in energy than the 3p State +then the 3D State the degeneracy in + + align:start position:0% +then the 3D State the degeneracy in + + + align:start position:0% +then the 3D State the degeneracy in +those States is lifted or it's + + align:start position:0% +those States is lifted or it's + + + align:start position:0% +those States is lifted or it's +broken + + align:start position:0% +broken + + + align:start position:0% +broken +right so that's now what we have to talk + + align:start position:0% +right so that's now what we have to talk + + + align:start position:0% +right so that's now what we have to talk +about is why that is the case why is 2s + + align:start position:0% +about is why that is the case why is 2s + + + align:start position:0% +about is why that is the case why is 2s +for example lower in energy than + + align:start position:0% +for example lower in energy than + + + align:start position:0% +for example lower in energy than +2p and the reason for this has to do + + align:start position:0% +2p and the reason for this has to do + + + align:start position:0% +2p and the reason for this has to do +with the phenomenon called + + align:start position:0% +with the phenomenon called + + + align:start position:0% +with the phenomenon called +shielding so we have to uh talk about + + align:start position:0% +shielding so we have to uh talk about + + + align:start position:0% +shielding so we have to uh talk about +this phenomena + + align:start position:0% +this phenomena + + + align:start position:0% +this phenomena +shielding and uh we have to talk about + + align:start position:0% +shielding and uh we have to talk about + + + align:start position:0% +shielding and uh we have to talk about +how that leads to a concept called + + align:start position:0% +how that leads to a concept called + + + align:start position:0% +how that leads to a concept called +effective + + align:start position:0% +effective + + + align:start position:0% +effective +charge okay but to do + + align:start position:0% +charge okay but to do + + + align:start position:0% +charge okay but to do +that I'm going + + align:start position:0% +that I'm going + + + align:start position:0% +that I'm going +to do the following I'm going to realize + + align:start position:0% +to do the following I'm going to realize + + + align:start position:0% +to do the following I'm going to realize +that each one of these energies here e + + align:start position:0% +that each one of these energies here e + + + align:start position:0% +that each one of these energies here e +sub NL + + align:start position:0% +sub NL + + + align:start position:0% +sub NL +right so now these energies are labeled + + align:start position:0% +right so now these energies are labeled + + + align:start position:0% +right so now these energies are labeled +by both the principal quantum number and + + align:start position:0% +by both the principal quantum number and + + + align:start position:0% +by both the principal quantum number and +the angular momentum quantum + + align:start position:0% +the angular momentum quantum + + + align:start position:0% +the angular momentum quantum +number I'm going to realize that these + + align:start position:0% +number I'm going to realize that these + + + align:start position:0% +number I'm going to realize that these +energies here physically are minus the + + align:start position:0% +energies here physically are minus the + + + align:start position:0% +energies here physically are minus the +ionization + + align:start position:0% +ionization + + + align:start position:0% +ionization +energy right because because these + + align:start position:0% +energy right because because these + + + align:start position:0% +energy right because because these +energies are minus the energy it's going + + align:start position:0% +energies are minus the energy it's going + + + align:start position:0% +energies are minus the energy it's going +to require to rip the electron off from + + align:start position:0% +to require to rip the electron off from + + + align:start position:0% +to require to rip the electron off from +that particular + + align:start position:0% +that particular + + + align:start position:0% +that particular +State and I'm going to set those binding + + align:start position:0% +State and I'm going to set those binding + + + align:start position:0% +State and I'm going to set those binding +energies equal to a hydrogen atom like + + align:start position:0% +energies equal to a hydrogen atom like + + + align:start position:0% +energies equal to a hydrogen atom like +energy level here and now I'm going to + + align:start position:0% +energy level here and now I'm going to + + + align:start position:0% +energy level here and now I'm going to +use the board and we're going to explain + + align:start position:0% +use the board and we're going to explain + + + align:start position:0% +use the board and we're going to explain +that just a little bit + + align:start position:0% + + + + align:start position:0% + +more + + align:start position:0% + + + + align:start position:0% + +oops okay so I + + align:start position:0% +oops okay so I + + + align:start position:0% +oops okay so I +said these energies which are Now + + align:start position:0% +said these energies which are Now + + + align:start position:0% +said these energies which are Now +function of nnl + + align:start position:0% +function of nnl + + + align:start position:0% +function of nnl +they're minus the ionization + + align:start position:0% +they're minus the ionization + + + align:start position:0% +they're minus the ionization +energy from that NL State and I'm going + + align:start position:0% +energy from that NL State and I'm going + + + align:start position:0% +energy from that NL State and I'm going +to approximate that as a hydrogen atom + + align:start position:0% +to approximate that as a hydrogen atom + + + align:start position:0% +to approximate that as a hydrogen atom +kind of an energy scheme that is I'm + + align:start position:0% +kind of an energy scheme that is I'm + + + align:start position:0% +kind of an energy scheme that is I'm +going to set this equal to R subh the + + align:start position:0% +going to set this equal to R subh the + + + align:start position:0% +going to set this equal to R subh the +ridberg constant over + + align:start position:0% +ridberg constant over + + + align:start position:0% +ridberg constant over +N2 but out here there's going to be a + + align:start position:0% +N2 but out here there's going to be a + + + align:start position:0% +N2 but out here there's going to be a +z but this Z is going to be Z effective + + align:start position:0% +z but this Z is going to be Z effective + + + align:start position:0% +z but this Z is going to be Z effective +z e + + align:start position:0% +z e + + + align:start position:0% +z e +FF and it's going to be squared of + + align:start position:0% +FF and it's going to be squared of + + + align:start position:0% +FF and it's going to be squared of +course and that Z is going to depend on + + align:start position:0% +course and that Z is going to depend on + + + align:start position:0% +course and that Z is going to depend on +the particular NL state that you're in + + align:start position:0% +the particular NL state that you're in + + + align:start position:0% +the particular NL state that you're in +okay this Z effective + + align:start position:0% + + + + align:start position:0% + +here is the effective nuclear + + align:start position:0% +here is the effective nuclear + + + align:start position:0% +here is the effective nuclear +charge it is not the nuclear + + align:start position:0% +charge it is not the nuclear + + + align:start position:0% +charge it is not the nuclear +charge it's the effective nuclear + + align:start position:0% +charge it's the effective nuclear + + + align:start position:0% +charge it's the effective nuclear +charge why well because of + + align:start position:0% +charge why well because of + + + align:start position:0% +charge why well because of +shielding so let's try to explain that + + align:start position:0% +shielding so let's try to explain that + + + align:start position:0% +shielding so let's try to explain that +so let's take helium all right helium Z + + align:start position:0% +so let's take helium all right helium Z + + + align:start position:0% +so let's take helium all right helium Z +is equal to + 2 e all right so we + + align:start position:0% +is equal to + 2 e all right so we + + + align:start position:0% +is equal to + 2 e all right so we +have plus 2 e here and now let's do a + + align:start position:0% +have plus 2 e here and now let's do a + + + align:start position:0% +have plus 2 e here and now let's do a +thought + + align:start position:0% +thought + + + align:start position:0% +thought +experiment in that we're going to take + + align:start position:0% +experiment in that we're going to take + + + align:start position:0% +experiment in that we're going to take +electron number two here right and we're + + align:start position:0% +electron number two here right and we're + + + align:start position:0% +electron number two here right and we're +going to place electron number two kind + + align:start position:0% +going to place electron number two kind + + + align:start position:0% +going to place electron number two kind +of close to the + + align:start position:0% +of close to the + + + align:start position:0% +of close to the +plus two charge + + align:start position:0% +plus two charge + + + align:start position:0% +plus two charge +nucleus and then we're going to have + + align:start position:0% +nucleus and then we're going to have + + + align:start position:0% +nucleus and then we're going to have +electron number one way out here + + align:start position:0% +electron number one way out here + + + align:start position:0% +electron number one way out here +right so in this case with electron + + align:start position:0% +right so in this case with electron + + + align:start position:0% +right so in this case with electron +number one way out here well the nuclear + + align:start position:0% +number one way out here well the nuclear + + + align:start position:0% +number one way out here well the nuclear +charge that electron number one + + align:start position:0% +charge that electron number one + + + align:start position:0% +charge that electron number one +experiences because it's so far out that + + align:start position:0% +experiences because it's so far out that + + + align:start position:0% +experiences because it's so far out that +nuclear charge kind of looks like a plus + + align:start position:0% +nuclear charge kind of looks like a plus + + + align:start position:0% +nuclear charge kind of looks like a plus +one charge right because this electron + + align:start position:0% +one charge right because this electron + + + align:start position:0% +one charge right because this electron +on the average is canceling one of the + + align:start position:0% +on the average is canceling one of the + + + align:start position:0% +on the average is canceling one of the +positive charges on the + + align:start position:0% +positive charges on the + + + align:start position:0% +positive charges on the +nucleus so the effective charge here for + + align:start position:0% +nucleus so the effective charge here for + + + align:start position:0% +nucleus so the effective charge here for +this electron way out there we're going + + align:start position:0% +this electron way out there we're going + + + align:start position:0% +this electron way out there we're going +to say is+ + + align:start position:0% +to say is+ + + + align:start position:0% +to say is+ +one if that's the case well then The + + align:start position:0% +one if that's the case well then The + + + align:start position:0% +one if that's the case well then The +Binding energy of that electron right is + + align:start position:0% +Binding energy of that electron right is + + + align:start position:0% +Binding energy of that electron right is +1^ 2 * R subh over n 2 all right we're + + align:start position:0% +1^ 2 * R subh over n 2 all right we're + + + align:start position:0% +1^ 2 * R subh over n 2 all right we're +going to consider n equal 1 because + + align:start position:0% +going to consider n equal 1 because + + + align:start position:0% +going to consider n equal 1 because +we're going to talk about the ground + + align:start position:0% +we're going to talk about the ground + + + align:start position:0% +we're going to talk about the ground +state of the helium atom here but you + + align:start position:0% +state of the helium atom here but you + + + align:start position:0% +state of the helium atom here but you +know what this value is going to turn + + align:start position:0% +know what this value is going to turn + + + align:start position:0% +know what this value is going to turn +out to be it's going to turn out to be - + + align:start position:0% +out to be it's going to turn out to be - + + + align:start position:0% +out to be it's going to turn out to be - +2.18 * 10- 18 jewles Hey That's The + + align:start position:0% +2.18 * 10- 18 jewles Hey That's The + + + align:start position:0% +2.18 * 10- 18 jewles Hey That's The +Binding energy of an electron and a + + align:start position:0% +Binding energy of an electron and a + + + align:start position:0% +Binding energy of an electron and a +hydrogen atom okay when this is a + + align:start position:0% +hydrogen atom okay when this is a + + + align:start position:0% +hydrogen atom okay when this is a +thought experiment now right so this is + + align:start position:0% +thought experiment now right so this is + + + align:start position:0% +thought experiment now right so this is +helium this is just one electron way out + + align:start position:0% +helium this is just one electron way out + + + align:start position:0% +helium this is just one electron way out +here and it can't discriminate too well + + align:start position:0% +here and it can't discriminate too well + + + align:start position:0% +here and it can't discriminate too well +between the nucleus and this electron so + + align:start position:0% +between the nucleus and this electron so + + + align:start position:0% +between the nucleus and this electron so +the overall effective charge it sees is + + align:start position:0% +the overall effective charge it sees is + + + align:start position:0% +the overall effective charge it sees is +plus + + align:start position:0% +plus + + + align:start position:0% +plus +one all right but now we take the other + + align:start position:0% +one all right but now we take the other + + + align:start position:0% +one all right but now we take the other +case The Other Extreme case + + align:start position:0% + + + + align:start position:0% + +is we're going to bring in electron one + + align:start position:0% +is we're going to bring in electron one + + + align:start position:0% +is we're going to bring in electron one +really close to the nucleus right and + + align:start position:0% +really close to the nucleus right and + + + align:start position:0% +really close to the nucleus right and +electron 2 is way out here such that + + align:start position:0% +electron 2 is way out here such that + + + align:start position:0% +electron 2 is way out here such that +electron to doesn't do anything as far + + align:start position:0% +electron to doesn't do anything as far + + + align:start position:0% +electron to doesn't do anything as far +as this electron is concerned right and + + align:start position:0% +as this electron is concerned right and + + + align:start position:0% +as this electron is concerned right and +so this electron in this case is + + align:start position:0% +so this electron in this case is + + + align:start position:0% +so this electron in this case is +experiencing the total nuclear charge on + + align:start position:0% +experiencing the total nuclear charge on + + + align:start position:0% +experiencing the total nuclear charge on +the nucleus and so we say in + + align:start position:0% +the nucleus and so we say in + + + align:start position:0% +the nucleus and so we say in +this thought case here with this + + align:start position:0% +this thought case here with this + + + align:start position:0% +this thought case here with this +electron really close + + align:start position:0% +electron really close + + + align:start position:0% +electron really close +that the effective charge is equal to+ 2 + + align:start position:0% +that the effective charge is equal to+ 2 + + + align:start position:0% +that the effective charge is equal to+ 2 +e for this + + align:start position:0% +e for this + + + align:start position:0% +e for this +electron well if that's the case we can + + align:start position:0% +electron well if that's the case we can + + + align:start position:0% +electron well if that's the case we can +calculate the binding energy of this + + align:start position:0% +calculate the binding energy of this + + + align:start position:0% +calculate the binding energy of this +electron and um that's going to be 2^ + + align:start position:0% +electron and um that's going to be 2^ + + + align:start position:0% +electron and um that's going to be 2^ +2ar over uh time R subh over 1^ + + align:start position:0% +2ar over uh time R subh over 1^ + + + align:start position:0% +2ar over uh time R subh over 1^ +2 we can plug in our subh and we're + + align:start position:0% +2 we can plug in our subh and we're + + + align:start position:0% +2 we can plug in our subh and we're +going to get minus 8 + + align:start position:0% +going to get minus 8 + + + align:start position:0% +going to get minus 8 +72 * 10- 18 juw okay what this is is The + + align:start position:0% +72 * 10- 18 juw okay what this is is The + + + align:start position:0% +72 * 10- 18 juw okay what this is is The +Binding + + align:start position:0% +Binding + + + align:start position:0% +Binding +energy of a electron in helium plus + + align:start position:0% +energy of a electron in helium plus + + + align:start position:0% +energy of a electron in helium plus +right + + align:start position:0% +right + + + align:start position:0% +right +okay and so in this extreme case with + + align:start position:0% +okay and so in this extreme case with + + + align:start position:0% +okay and so in this extreme case with +the electron really close in That's The + + align:start position:0% +the electron really close in That's The + + + align:start position:0% +the electron really close in That's The +Binding energy with this extreme case + + align:start position:0% +Binding energy with this extreme case + + + align:start position:0% +Binding energy with this extreme case +with the electron way far out this is + + align:start position:0% +with the electron way far out this is + + + align:start position:0% +with the electron way far out this is +The Binding + + align:start position:0% +The Binding + + + align:start position:0% +The Binding +energy this is total + + align:start position:0% + + + + align:start position:0% + +shielding this case is no + + align:start position:0% +shielding this case is no + + + align:start position:0% +shielding this case is no +shielding no shielding the electron is + + align:start position:0% +shielding no shielding the electron is + + + align:start position:0% +shielding no shielding the electron is +much more strongly + + align:start position:0% +much more strongly + + + align:start position:0% +much more strongly +bound the reality is that The Binding + + align:start position:0% +bound the reality is that The Binding + + + align:start position:0% +bound the reality is that The Binding +energy of an electron in helium is + + align:start position:0% +energy of an electron in helium is + + + align:start position:0% +energy of an electron in helium is +somewhere in + + align:start position:0% +somewhere in + + + align:start position:0% +somewhere in +between right that is the ionization + + align:start position:0% +between right that is the ionization + + + align:start position:0% +between right that is the ionization +energy for helium for an electron in now + + align:start position:0% +energy for helium for an electron in now + + + align:start position:0% +energy for helium for an electron in now +neutral helium here the ionization + + align:start position:0% +neutral helium here the ionization + + + align:start position:0% +neutral helium here the ionization +energy is + + align:start position:0% +energy is + + + align:start position:0% +energy is +3.94 time 10- 18 + + align:start position:0% +3.94 time 10- 18 + + + align:start position:0% +3.94 time 10- 18 +jewles somewhere in between this extreme + + align:start position:0% +jewles somewhere in between this extreme + + + align:start position:0% +jewles somewhere in between this extreme +case of total + + align:start position:0% +case of total + + + align:start position:0% +case of total +shielding and this extreme case of no + + align:start position:0% +shielding and this extreme case of no + + + align:start position:0% +shielding and this extreme case of no +shielding at + + align:start position:0% +shielding at + + + align:start position:0% +shielding at +all and that's because on the + + align:start position:0% +all and that's because on the + + + align:start position:0% +all and that's because on the +average right there is is another + + align:start position:0% +average right there is is another + + + align:start position:0% +average right there is is another +electron in between that electron and + + align:start position:0% +electron in between that electron and + + + align:start position:0% +electron in between that electron and +the + + align:start position:0% +the + + + align:start position:0% +the +nucleus and we can calculate the + + align:start position:0% +nucleus and we can calculate the + + + align:start position:0% +nucleus and we can calculate the +effective charge then from the + + align:start position:0% +effective charge then from the + + + align:start position:0% +effective charge then from the +experimental binding energies by just + + align:start position:0% +experimental binding energies by just + + + align:start position:0% +experimental binding energies by just +taking this expression and rearranging + + align:start position:0% +taking this expression and rearranging + + + align:start position:0% +taking this expression and rearranging +it right so I'm going to solve that + + align:start position:0% +it right so I'm going to solve that + + + align:start position:0% +it right so I'm going to solve that +expression for the effective charge z e + + align:start position:0% +expression for the effective charge z e + + + align:start position:0% +expression for the effective charge z e +FF and when I do that that of course is + + align:start position:0% +FF and when I do that that of course is + + + align:start position:0% +FF and when I do that that of course is +s times then the ionization + + align:start position:0% +s times then the ionization + + + align:start position:0% +s times then the ionization +energy over the ridberg + + align:start position:0% +energy over the ridberg + + + align:start position:0% +energy over the ridberg +constant right n s is going to be one + + align:start position:0% +constant right n s is going to be one + + + align:start position:0% +constant right n s is going to be one +because we're talking about the ground + + align:start position:0% +because we're talking about the ground + + + align:start position:0% +because we're talking about the ground +state the ionization energy I said was + + align:start position:0% +state the ionization energy I said was + + + align:start position:0% +state the ionization energy I said was +3.94 * 10- 18 jewles redberg constant is + + align:start position:0% +3.94 * 10- 18 jewles redberg constant is + + + align:start position:0% +3.94 * 10- 18 jewles redberg constant is +2.18 * 10us 18 jewles right in the end I + + align:start position:0% +2.18 * 10us 18 jewles right in the end I + + + align:start position:0% +2.18 * 10us 18 jewles right in the end I +find an effective charge here of plus + + align:start position:0% +find an effective charge here of plus + + + align:start position:0% +find an effective charge here of plus +1.34 okay and again why is that the case + + align:start position:0% +1.34 okay and again why is that the case + + + align:start position:0% +1.34 okay and again why is that the case +well that's the case because if uh + + align:start position:0% +well that's the case because if uh + + + align:start position:0% +well that's the case because if uh +here's my + + align:start position:0% +here's my + + + align:start position:0% +here's my +electron here's my helium + + align:start position:0% +electron here's my helium + + + align:start position:0% +electron here's my helium +nucleus well just on the average right + + align:start position:0% +nucleus well just on the average right + + + align:start position:0% +nucleus well just on the average right +between this electron and the nucleus + + align:start position:0% +between this electron and the nucleus + + + align:start position:0% +between this electron and the nucleus +there's always another electron around + + align:start position:0% +there's always another electron around + + + align:start position:0% +there's always another electron around +this electron kind of partially Shields + + align:start position:0% +this electron kind of partially Shields + + + align:start position:0% +this electron kind of partially Shields +this nuclear charge partially Shields it + + align:start position:0% +this nuclear charge partially Shields it + + + align:start position:0% +this nuclear charge partially Shields it +so that we calculated from using this + + align:start position:0% +so that we calculated from using this + + + align:start position:0% +so that we calculated from using this +scheme and using the experimental + + align:start position:0% +scheme and using the experimental + + + align:start position:0% +scheme and using the experimental +ionization energies we calculated an + + align:start position:0% +ionization energies we calculated an + + + align:start position:0% +ionization energies we calculated an +effective charge of + + align:start position:0% +effective charge of + + + align:start position:0% +effective charge of + + align:start position:0% + + + align:start position:0% +okay all right so now we sort of + + align:start position:0% +okay all right so now we sort of + + + align:start position:0% +okay all right so now we sort of +understand shielding and effective + + align:start position:0% +understand shielding and effective + + + align:start position:0% +understand shielding and effective +charge + + align:start position:0% +charge + + + align:start position:0% +charge +right that's a square root thank + + align:start position:0% +right that's a square root thank + + + align:start position:0% +right that's a square root thank +you right + + align:start position:0% +you right + + + align:start position:0% +you right +okay all + + align:start position:0% +okay all + + + align:start position:0% +okay all +right + + align:start position:0% +right + + + align:start position:0% +right +okay but now we have to use this idea of + + align:start position:0% +okay but now we have to use this idea of + + + align:start position:0% +okay but now we have to use this idea of +effective charge and shielding to + + align:start position:0% +effective charge and shielding to + + + align:start position:0% +effective charge and shielding to +understand why the 2s state is lower in + + align:start position:0% +understand why the 2s state is lower in + + + align:start position:0% +understand why the 2s state is lower in +energy than the 2p + + align:start position:0% +energy than the 2p + + + align:start position:0% +energy than the 2p +State all right and here comes that + + align:start position:0% + + + + align:start position:0% + +all right let's think about the lithium + + align:start position:0% +all right let's think about the lithium + + + align:start position:0% +all right let's think about the lithium +atom all right the electron + + align:start position:0% +atom all right the electron + + + align:start position:0% +atom all right the electron +configuration of lithium is 1 S2 + + align:start position:0% +configuration of lithium is 1 S2 + + + align:start position:0% +configuration of lithium is 1 S2 +2s1 the electron configuration of + + align:start position:0% +2s1 the electron configuration of + + + align:start position:0% +2s1 the electron configuration of +lithium is not 1 S2 2 P1 why because 2s + + align:start position:0% +lithium is not 1 S2 2 P1 why because 2s + + + align:start position:0% +lithium is not 1 S2 2 P1 why because 2s +is lower in energy than + + align:start position:0% +is lower in energy than + + + align:start position:0% +is lower in energy than +2p but why is that the case well to look + + align:start position:0% +2p but why is that the case well to look + + + align:start position:0% +2p but why is that the case well to look +at that we got to look at the radial + + align:start position:0% +at that we got to look at the radial + + + align:start position:0% +at that we got to look at the radial +probability distribution functions for + + align:start position:0% +probability distribution functions for + + + align:start position:0% +probability distribution functions for +2s and 2 + + align:start position:0% +2s and 2 + + + align:start position:0% +2s and 2 +p so here's the radial probability + + align:start position:0% +p so here's the radial probability + + + align:start position:0% +p so here's the radial probability +distribution function for + + align:start position:0% +distribution function for + + + align:start position:0% +distribution function for +2s here's the uh radial probability + + align:start position:0% +2s here's the uh radial probability + + + align:start position:0% +2s here's the uh radial probability +distribution function for + + align:start position:0% + + + + align:start position:0% + +2p okay now you have to uh do a thought + + align:start position:0% +2p okay now you have to uh do a thought + + + align:start position:0% +2p okay now you have to uh do a thought +experiment here in this 2s radial + + align:start position:0% +experiment here in this 2s radial + + + align:start position:0% +experiment here in this 2s radial +probability distribution + + align:start position:0% +probability distribution + + + align:start position:0% +probability distribution +function what you see is that there is + + align:start position:0% +function what you see is that there is + + + align:start position:0% +function what you see is that there is +some finite + + align:start position:0% +some finite + + + align:start position:0% +some finite +probability of the electron in the 2s + + align:start position:0% +probability of the electron in the 2s + + + align:start position:0% +probability of the electron in the 2s +State being really close to the + + align:start position:0% +State being really close to the + + + align:start position:0% +State being really close to the +nucleus for the sake of the argument + + align:start position:0% +nucleus for the sake of the argument + + + align:start position:0% +nucleus for the sake of the argument +here I'm going to + + align:start position:0% +here I'm going to + + + align:start position:0% +here I'm going to +say that for this part of the + + align:start position:0% +say that for this part of the + + + align:start position:0% +say that for this part of the +probability distribution function for + + align:start position:0% +probability distribution function for + + + align:start position:0% +probability distribution function for +that part the effective charge Z + + align:start position:0% +that part the effective charge Z + + + align:start position:0% +that part the effective charge Z +effective is going to be plus + + align:start position:0% +effective is going to be plus + + + align:start position:0% +effective is going to be plus +3E okay I mean that's an exaggeration + + align:start position:0% +3E okay I mean that's an exaggeration + + + align:start position:0% +3E okay I mean that's an exaggeration +because obviously we have some s + + align:start position:0% +because obviously we have some s + + + align:start position:0% +because obviously we have some s +electrons but for the sake of this + + align:start position:0% +electrons but for the sake of this + + + align:start position:0% +electrons but for the sake of this +argument I'm going to say the effective + + align:start position:0% +argument I'm going to say the effective + + + align:start position:0% +argument I'm going to say the effective +charge for this part of the probability + + align:start position:0% +charge for this part of the probability + + + align:start position:0% +charge for this part of the probability +distribution function is plus + + align:start position:0% +distribution function is plus + + + align:start position:0% +distribution function is plus +3E for this part of the probability + + align:start position:0% +3E for this part of the probability + + + align:start position:0% +3E for this part of the probability +distribution function for 2s hey that's + + align:start position:0% +distribution function for 2s hey that's + + + align:start position:0% +distribution function for 2s hey that's +much further out and I have those 1s + + align:start position:0% +much further out and I have those 1s + + + align:start position:0% +much further out and I have those 1s +electrons closer in so for the sake of + + align:start position:0% +electrons closer in so for the sake of + + + align:start position:0% +electrons closer in so for the sake of +this argument I'm going to say that + + align:start position:0% +this argument I'm going to say that + + + align:start position:0% +this argument I'm going to say that +these s electrons completely Shield the + + align:start position:0% +these s electrons completely Shield the + + + align:start position:0% +these s electrons completely Shield the +nuclear charge and so the effective + + align:start position:0% +nuclear charge and so the effective + + + align:start position:0% +nuclear charge and so the effective +charge for this part of the distribution + + align:start position:0% +charge for this part of the distribution + + + align:start position:0% +charge for this part of the distribution +is plus one + + align:start position:0% +is plus one + + + align:start position:0% +is plus one +e okay now what about + + align:start position:0% +e okay now what about + + + align:start position:0% +e okay now what about +2p well in the case of 2p you can + + align:start position:0% +2p well in the case of 2p you can + + + align:start position:0% +2p well in the case of 2p you can +see that this 2p wave function although + + align:start position:0% +see that this 2p wave function although + + + align:start position:0% +see that this 2p wave function although +it's a little bit closer in hey for the + + align:start position:0% +it's a little bit closer in hey for the + + + align:start position:0% +it's a little bit closer in hey for the +most part it is about in the same place + + align:start position:0% +most part it is about in the same place + + + align:start position:0% +most part it is about in the same place +as + + align:start position:0% +as + + + align:start position:0% +as +this uh the second lobe here of the 2s + + align:start position:0% +this uh the second lobe here of the 2s + + + align:start position:0% +this uh the second lobe here of the 2s +wave + + align:start position:0% +wave + + + align:start position:0% +wave +function so we're going to say that this + + align:start position:0% +function so we're going to say that this + + + align:start position:0% +function so we're going to say that this +effective + + align:start position:0% +effective + + + align:start position:0% +effective +charge is + one e just like this lobe of + + align:start position:0% +charge is + one e just like this lobe of + + + align:start position:0% +charge is + one e just like this lobe of +the 2s wave + + align:start position:0% +the 2s wave + + + align:start position:0% +the 2s wave +function but now to get the kind of + + align:start position:0% +function but now to get the kind of + + + align:start position:0% +function but now to get the kind of +total effective charge I'm going to have + + align:start position:0% +total effective charge I'm going to have + + + align:start position:0% +total effective charge I'm going to have +to take the effective charge and average + + align:start position:0% +to take the effective charge and average + + + align:start position:0% +to take the effective charge and average +it over this probability distribution + + align:start position:0% +it over this probability distribution + + + align:start position:0% +it over this probability distribution +function and so since in the 2s function + + align:start position:0% +function and so since in the 2s function + + + align:start position:0% +function and so since in the 2s function +I'm going to average over a part that + + align:start position:0% +I'm going to average over a part that + + + align:start position:0% +I'm going to average over a part that +has a plus three effective charge and a + + align:start position:0% +has a plus three effective charge and a + + + align:start position:0% +has a plus three effective charge and a +PL part that that has a plus one + + align:start position:0% +PL part that that has a plus one + + + align:start position:0% +PL part that that has a plus one +effective charge well if I average over + + align:start position:0% +effective charge well if I average over + + + align:start position:0% +effective charge well if I average over +that that's going to be larger than the + + align:start position:0% +that that's going to be larger than the + + + align:start position:0% +that that's going to be larger than the +effective charge of this 2p wave + + align:start position:0% +effective charge of this 2p wave + + + align:start position:0% +effective charge of this 2p wave +function right because the 2p everywhere + + align:start position:0% +function right because the 2p everywhere + + + align:start position:0% +function right because the 2p everywhere +is plus + + align:start position:0% +is plus + + + align:start position:0% +is plus +one so the effective charge here for the + + align:start position:0% +one so the effective charge here for the + + + align:start position:0% +one so the effective charge here for the +2s is going to be greater on the average + + align:start position:0% +2s is going to be greater on the average + + + align:start position:0% +2s is going to be greater on the average +than for the + + align:start position:0% +than for the + + + align:start position:0% +than for the +2p because of this part of the + + align:start position:0% +2p because of this part of the + + + align:start position:0% +2p because of this part of the +probability distribution function this + + align:start position:0% +probability distribution function this + + + align:start position:0% +probability distribution function this +part that's really close to the nucleus + + align:start position:0% +part that's really close to the nucleus + + + align:start position:0% +part that's really close to the nucleus +where the electrons can feel more of the + + align:start position:0% +where the electrons can feel more of the + + + align:start position:0% +where the electrons can feel more of the +nuclear charge or experience more of the + + align:start position:0% +nuclear charge or experience more of the + + + align:start position:0% +nuclear charge or experience more of the +nuclear charge than they could if they + + align:start position:0% +nuclear charge than they could if they + + + align:start position:0% +nuclear charge than they could if they +were a a 2p + + align:start position:0% +were a a 2p + + + align:start position:0% +were a a 2p +electron okay so therefore since the 2s + + align:start position:0% +electron okay so therefore since the 2s + + + align:start position:0% +electron okay so therefore since the 2s +electron has a greater effective charge + + align:start position:0% +electron has a greater effective charge + + + align:start position:0% +electron has a greater effective charge +here well what that's going to mean is + + align:start position:0% +here well what that's going to mean is + + + align:start position:0% +here well what that's going to mean is +that The Binding energy of the 2s state + + align:start position:0% +that The Binding energy of the 2s state + + + align:start position:0% +that The Binding energy of the 2s state +is going to be lower in energy it's + + align:start position:0% +is going to be lower in energy it's + + + align:start position:0% +is going to be lower in energy it's +going to be more negative Than The + + align:start position:0% +going to be more negative Than The + + + align:start position:0% +going to be more negative Than The +Binding energy of the 2p + + align:start position:0% +Binding energy of the 2p + + + align:start position:0% +Binding energy of the 2p +State same thing for 3s and + + align:start position:0% +State same thing for 3s and + + + align:start position:0% +State same thing for 3s and +3p all right same reasoning there and + + align:start position:0% +3p all right same reasoning there and + + + align:start position:0% +3p all right same reasoning there and +it's all because of this little part of + + align:start position:0% +it's all because of this little part of + + + align:start position:0% +it's all because of this little part of +the probability distribution function + + align:start position:0% +the probability distribution function + + + align:start position:0% +the probability distribution function +all right so now we can understand why + + align:start position:0% +all right so now we can understand why + + + align:start position:0% +all right so now we can understand why +the 2s is in fact lower in energy than + + align:start position:0% +the 2s is in fact lower in energy than + + + align:start position:0% +the 2s is in fact lower in energy than +the + + align:start position:0% +the + + + align:start position:0% +the +2p all right + + align:start position:0% + + + + align:start position:0% + +yeah the three well because the 3s um + + align:start position:0% +yeah the three well because the 3s um + + + align:start position:0% +yeah the three well because the 3s um +although it does in fact have this it's + + align:start position:0% +although it does in fact have this it's + + + align:start position:0% +although it does in fact have this it's +a little bit further out here enough to + + align:start position:0% +a little bit further out here enough to + + + align:start position:0% +a little bit further out here enough to +make for this to compensate but again 3s + + align:start position:0% +make for this to compensate but again 3s + + + align:start position:0% +make for this to compensate but again 3s +is lower than 3p right so we're just + + align:start position:0% +is lower than 3p right so we're just + + + align:start position:0% +is lower than 3p right so we're just +going to compare 3s and 3p within the + + align:start position:0% +going to compare 3s and 3p within the + + + align:start position:0% +going to compare 3s and 3p within the +same shell all + + align:start position:0% +same shell all + + + align:start position:0% +same shell all +right + + align:start position:0% + + + + align:start position:0% + +okay yes right it does have to do with + + align:start position:0% +okay yes right it does have to do with + + + align:start position:0% +okay yes right it does have to do with +the net area underneath if the + + align:start position:0% +the net area underneath if the + + + align:start position:0% +the net area underneath if the +probability were much higher and it's + + align:start position:0% +probability were much higher and it's + + + align:start position:0% +probability were much higher and it's +and it's not that much higher uh but if + + align:start position:0% +and it's not that much higher uh but if + + + align:start position:0% +and it's not that much higher uh but if +it were then you you're right it could + + align:start position:0% +it were then you you're right it could + + + align:start position:0% +it were then you you're right it could +cancel it out right right + + align:start position:0% +cancel it out right right + + + align:start position:0% +cancel it out right right +okay okay + + align:start position:0% +okay okay + + + align:start position:0% +okay okay +so now therefore we're ready to write + + align:start position:0% +so now therefore we're ready to write + + + align:start position:0% +so now therefore we're ready to write +the electron + + align:start position:0% +the electron + + + align:start position:0% +the electron +configurations of uh all the atoms in + + align:start position:0% +configurations of uh all the atoms in + + + align:start position:0% +configurations of uh all the atoms in +the on the periodic + + align:start position:0% +the on the periodic + + + align:start position:0% +the on the periodic +table and you already know that we use + + align:start position:0% +table and you already know that we use + + + align:start position:0% +table and you already know that we use +the albow principle to do + + align:start position:0% +the albow principle to do + + + align:start position:0% +the albow principle to do +that alow means building + + align:start position:0% +that alow means building + + + align:start position:0% +that alow means building +up so what do you do you take all the + + align:start position:0% +up so what do you do you take all the + + + align:start position:0% +up so what do you do you take all the +states the the allowed + + align:start position:0% +states the the allowed + + + align:start position:0% +states the the allowed +States and you order them according to + + align:start position:0% +States and you order them according to + + + align:start position:0% +States and you order them according to +their energy + + align:start position:0% +their energy + + + align:start position:0% +their energy +most strongly bound or most negative + + align:start position:0% +most strongly bound or most negative + + + align:start position:0% +most strongly bound or most negative +energy goes on the bottom and next most + + align:start position:0% +energy goes on the bottom and next most + + + align:start position:0% +energy goes on the bottom and next most +negative + + align:start position:0% +negative + + + align:start position:0% +negative +energy on and on and we'll talk about an + + align:start position:0% +energy on and on and we'll talk about an + + + align:start position:0% +energy on and on and we'll talk about an +pneumonic for remembering those energies + + align:start position:0% +pneumonic for remembering those energies + + + align:start position:0% +pneumonic for remembering those energies +in a moment + + align:start position:0% +in a moment + + + align:start position:0% +in a moment +okay all right so we use the AL bow + + align:start position:0% +okay all right so we use the AL bow + + + align:start position:0% +okay all right so we use the AL bow +principle we start with the lowest + + align:start position:0% +principle we start with the lowest + + + align:start position:0% +principle we start with the lowest +energy State and we put an electron in + + align:start position:0% +energy State and we put an electron in + + + align:start position:0% +energy State and we put an electron in +for hydrogen there it is One S + + align:start position:0% +for hydrogen there it is One S + + + align:start position:0% +for hydrogen there it is One S +state for helium well we also put that + + align:start position:0% +state for helium well we also put that + + + align:start position:0% +state for helium well we also put that +in to the 1s State except as we fill + + align:start position:0% +in to the 1s State except as we fill + + + align:start position:0% +in to the 1s State except as we fill +these states we have to um heed the PO + + align:start position:0% +these states we have to um heed the PO + + + align:start position:0% +these states we have to um heed the PO +Exclusion Principle so this electron + + align:start position:0% +Exclusion Principle so this electron + + + align:start position:0% +Exclusion Principle so this electron +here goes in with the opposite + + align:start position:0% +here goes in with the opposite + + + align:start position:0% +here goes in with the opposite +spin all right next uh lithium 2s + + align:start position:0% +spin all right next uh lithium 2s + + + align:start position:0% +spin all right next uh lithium 2s +electron for brillium another 2s + + align:start position:0% +electron for brillium another 2s + + + align:start position:0% +electron for brillium another 2s +electron opposite + + align:start position:0% +electron opposite + + + align:start position:0% +electron opposite +Spin and then for um + + align:start position:0% +Spin and then for um + + + align:start position:0% +Spin and then for um +nitrogen electron here has to go into + + align:start position:0% +nitrogen electron here has to go into + + + align:start position:0% +nitrogen electron here has to go into +the 2p State now it doesn't matter + + align:start position:0% +the 2p State now it doesn't matter + + + align:start position:0% +the 2p State now it doesn't matter +whether you put it in 2px 2py or 2pz + + align:start position:0% +whether you put it in 2px 2py or 2pz + + + align:start position:0% +whether you put it in 2px 2py or 2pz +they're all the same energy + + align:start position:0% +they're all the same energy + + + align:start position:0% +they're all the same energy +okay all right but now the next um the + + align:start position:0% +okay all right but now the next um the + + + align:start position:0% +okay all right but now the next um the +next electron + + align:start position:0% +next electron + + + align:start position:0% +next electron +carbon uh what are we going to do here + + align:start position:0% +carbon uh what are we going to do here + + + align:start position:0% +carbon uh what are we going to do here +well here we have to obey something + + align:start position:0% +well here we have to obey something + + + align:start position:0% +well here we have to obey something +called Hunt's Rule and Hunt's rule says + + align:start position:0% +called Hunt's Rule and Hunt's rule says + + + align:start position:0% +called Hunt's Rule and Hunt's rule says +that when electrons are added to states + + align:start position:0% +that when electrons are added to states + + + align:start position:0% +that when electrons are added to states +of the same energy and that's what we're + + align:start position:0% +of the same energy and that's what we're + + + align:start position:0% +of the same energy and that's what we're +doing here in the + + align:start position:0% +doing here in the + + + align:start position:0% +doing here in the +2p a single electron enters each state + + align:start position:0% +2p a single electron enters each state + + + align:start position:0% +2p a single electron enters each state +before a second electron enters any + + align:start position:0% +before a second electron enters any + + + align:start position:0% +before a second electron enters any +state and those single electrons have to + + align:start position:0% +state and those single electrons have to + + + align:start position:0% +state and those single electrons have to +go in so that the resulting spins are + + align:start position:0% +go in so that the resulting spins are + + + align:start position:0% +go in so that the resulting spins are +parallel that is they have the same spin + + align:start position:0% +parallel that is they have the same spin + + + align:start position:0% +parallel that is they have the same spin +so do we put + + align:start position:0% +so do we put + + + align:start position:0% +so do we put +in do we put in an electron like this no + + align:start position:0% +in do we put in an electron like this no + + + align:start position:0% +in do we put in an electron like this no +do we put it in like that no do we put + + align:start position:0% +do we put it in like that no do we put + + + align:start position:0% +do we put it in like that no do we put +it in like this + + align:start position:0% +it in like this + + + align:start position:0% +it in like this +y okay according to Hunt's Rule and then + + align:start position:0% +y okay according to Hunt's Rule and then + + + align:start position:0% +y okay according to Hunt's Rule and then +the next electron has to go into that + + align:start position:0% +the next electron has to go into that + + + align:start position:0% +the next electron has to go into that +other empty P State before any of these + + align:start position:0% +other empty P State before any of these + + + align:start position:0% +other empty P State before any of these +states double up all right so then we + + align:start position:0% +states double up all right so then we + + + align:start position:0% +states double up all right so then we +keep doubling them up next electron has + + align:start position:0% +keep doubling them up next electron has + + + align:start position:0% +keep doubling them up next electron has +to go into the next state 3s again we + + align:start position:0% +to go into the next state 3s again we + + + align:start position:0% +to go into the next state 3s again we +double them up and now we're to the 3p + + align:start position:0% +double them up and now we're to the 3p + + + align:start position:0% +double them up and now we're to the 3p +State again one electron goes into 2px + + align:start position:0% +State again one electron goes into 2px + + + align:start position:0% +State again one electron goes into 2px +the next electron will go into either + + align:start position:0% +the next electron will go into either + + + align:start position:0% +the next electron will go into either +2py or 2pz according to Hunts Rule and + + align:start position:0% +2py or 2pz according to Hunts Rule and + + + align:start position:0% +2py or 2pz according to Hunts Rule and +the spins remain parallel to get the + + align:start position:0% +the spins remain parallel to get the + + + align:start position:0% +the spins remain parallel to get the +lowest energy + + align:start position:0% +lowest energy + + + align:start position:0% +lowest energy +configuration and then the next electron + + align:start position:0% +configuration and then the next electron + + + align:start position:0% +configuration and then the next electron +to pz and then we start doubling up all + + align:start position:0% +to pz and then we start doubling up all + + + align:start position:0% +to pz and then we start doubling up all +right and we keep going and you keep + + align:start position:0% +right and we keep going and you keep + + + align:start position:0% +right and we keep going and you keep +going in that way so that you write the + + align:start position:0% +going in that way so that you write the + + + align:start position:0% +going in that way so that you write the +electron configuration of all the atoms + + align:start position:0% +electron configuration of all the atoms + + + align:start position:0% +electron configuration of all the atoms +in the periodic + + align:start position:0% +in the periodic + + + align:start position:0% +in the periodic +table okay let's uh look at these + + align:start position:0% +table okay let's uh look at these + + + align:start position:0% +table okay let's uh look at these +electron configurations kind of quickly + + align:start position:0% +electron configurations kind of quickly + + + align:start position:0% +electron configurations kind of quickly +here let's start with uh let's start + + align:start position:0% +here let's start with uh let's start + + + align:start position:0% +here let's start with uh let's start +with the third period the third row + + align:start position:0% +with the third period the third row + + + align:start position:0% +with the third period the third row +here uh sodium going across here to + + align:start position:0% +here uh sodium going across here to + + + align:start position:0% +here uh sodium going across here to +argon here's the electron configuration + + align:start position:0% +argon here's the electron configuration + + + align:start position:0% +argon here's the electron configuration +for + + align:start position:0% +for + + + align:start position:0% +for +sodium notice here that I don't mind if + + align:start position:0% +sodium notice here that I don't mind if + + + align:start position:0% +sodium notice here that I don't mind if +you write that electron configuration is + + align:start position:0% +you write that electron configuration is + + + align:start position:0% +you write that electron configuration is +2p6 instead of 2px 2py 2pz because you + + align:start position:0% +2p6 instead of 2px 2py 2pz because you + + + align:start position:0% +2p6 instead of 2px 2py 2pz because you +can't tell the difference between X Y + + align:start position:0% +can't tell the difference between X Y + + + align:start position:0% +can't tell the difference between X Y +and Z anyway if you're not in a magnetic + + align:start position:0% +and Z anyway if you're not in a magnetic + + + align:start position:0% +and Z anyway if you're not in a magnetic +field + + align:start position:0% +field + + + align:start position:0% +field +okay these electrons here in sodium that + + align:start position:0% +okay these electrons here in sodium that + + + align:start position:0% +okay these electrons here in sodium that +make up the inner gas configuration + + align:start position:0% +make up the inner gas configuration + + + align:start position:0% +make up the inner gas configuration +argon of course are the core electrons + + align:start position:0% +argon of course are the core electrons + + + align:start position:0% +argon of course are the core electrons +so when we talk about core electrons + + align:start position:0% +so when we talk about core electrons + + + align:start position:0% +so when we talk about core electrons +we're talking about the electrons that + + align:start position:0% +we're talking about the electrons that + + + align:start position:0% +we're talking about the electrons that +make up the nearest rare gas config + + align:start position:0% +make up the nearest rare gas config + + + align:start position:0% +make up the nearest rare gas config +figuration and then the veence electron + + align:start position:0% +figuration and then the veence electron + + + align:start position:0% +figuration and then the veence electron +well the veence electron is the + + align:start position:0% +well the veence electron is the + + + align:start position:0% +well the veence electron is the +electrons that are beyond the nearest uh + + align:start position:0% +electrons that are beyond the nearest uh + + + align:start position:0% +electrons that are beyond the nearest uh +the nearest but lowest of in our gas + + align:start position:0% +the nearest but lowest of in our gas + + + align:start position:0% +the nearest but lowest of in our gas +configuration + + align:start position:0% +configuration + + + align:start position:0% +configuration +okay and also when you're writing these + + align:start position:0% +okay and also when you're writing these + + + align:start position:0% +okay and also when you're writing these +electron configurations say for sodium + + align:start position:0% +electron configurations say for sodium + + + align:start position:0% +electron configurations say for sodium +you can write it as the neon + + align:start position:0% +you can write it as the neon + + + align:start position:0% +you can write it as the neon +configuration and then just show the + + align:start position:0% +configuration and then just show the + + + align:start position:0% +configuration and then just show the +veence electron + + align:start position:0% +veence electron + + + align:start position:0% +veence electron +3s1 right so as we go across that third + + align:start position:0% +3s1 right so as we go across that third + + + align:start position:0% +3s1 right so as we go across that third +period here everything things very + + align:start position:0% +period here everything things very + + + align:start position:0% +period here everything things very +normal 3s fills up first then the 3 PS + + align:start position:0% +normal 3s fills up first then the 3 PS + + + align:start position:0% +normal 3s fills up first then the 3 PS +fill + + align:start position:0% +fill + + + align:start position:0% +fill +up all right but now we get to the + + align:start position:0% +up all right but now we get to the + + + align:start position:0% +up all right but now we get to the +fourth period from pottassium to + + align:start position:0% +fourth period from pottassium to + + + align:start position:0% +fourth period from pottassium to +Krypton now fourth period what happens + + align:start position:0% +Krypton now fourth period what happens + + + align:start position:0% +Krypton now fourth period what happens +here is that those first two electrons + + align:start position:0% +here is that those first two electrons + + + align:start position:0% +here is that those first two electrons +go into the S States they do not go into + + align:start position:0% +go into the S States they do not go into + + + align:start position:0% +go into the S States they do not go into +the 3D States they don't because those S + + align:start position:0% +the 3D States they don't because those S + + + align:start position:0% +the 3D States they don't because those S +electrons are lower in energy + + align:start position:0% +electrons are lower in energy + + + align:start position:0% +electrons are lower in energy +those S states are lower in energy than + + align:start position:0% +those S states are lower in energy than + + + align:start position:0% +those S states are lower in energy than +the 3D States and so these electron + + align:start position:0% +the 3D States and so these electron + + + align:start position:0% +the 3D States and so these electron +configurations are are gone 4s1 argone + + align:start position:0% +configurations are are gone 4s1 argone + + + align:start position:0% +configurations are are gone 4s1 argone +4s2 and then once we fill those 4S + + align:start position:0% +4s2 and then once we fill those 4S + + + align:start position:0% +4s2 and then once we fill those 4S +States well then we start filling the 3D + + align:start position:0% +States well then we start filling the 3D + + + align:start position:0% +States well then we start filling the 3D +States okay so here's Scandium here's + + align:start position:0% +States okay so here's Scandium here's + + + align:start position:0% +States okay so here's Scandium here's +titanium here's + + align:start position:0% +titanium here's + + + align:start position:0% +titanium here's +vadium everything's normal 3d1 3d2 3d3 + + align:start position:0% +vadium everything's normal 3d1 3d2 3d3 + + + align:start position:0% +vadium everything's normal 3d1 3d2 3d3 +and then we get to Crypt uh uh + + align:start position:0% +and then we get to Crypt uh uh + + + align:start position:0% +and then we get to Crypt uh uh +chromium right we have an exception here + + align:start position:0% +chromium right we have an exception here + + + align:start position:0% +chromium right we have an exception here +chromium chromium is not what you would + + align:start position:0% +chromium chromium is not what you would + + + align:start position:0% +chromium chromium is not what you would +expect chromium is 4s2 3d4medical.com + + align:start position:0% + + + + align:start position:0% + +but this is experimentally observed that + + align:start position:0% +but this is experimentally observed that + + + align:start position:0% +but this is experimentally observed that +this is the configuration why because + + align:start position:0% +this is the configuration why because + + + align:start position:0% +this is the configuration why because +it's lower in energy in total energy + + align:start position:0% +it's lower in energy in total energy + + + align:start position:0% +it's lower in energy in total energy +than this configuration all right it + + align:start position:0% +than this configuration all right it + + + align:start position:0% +than this configuration all right it +turns out that there's some extra + + align:start position:0% +turns out that there's some extra + + + align:start position:0% +turns out that there's some extra +stability in having a half fill 4S shell + + align:start position:0% +stability in having a half fill 4S shell + + + align:start position:0% +stability in having a half fill 4S shell +and a half fill 3D Shell + + align:start position:0% +and a half fill 3D Shell + + + align:start position:0% +and a half fill 3D Shell +subshell compared to having a filled 4S + + align:start position:0% +subshell compared to having a filled 4S + + + align:start position:0% +subshell compared to having a filled 4S +shell and a less than half filed 3D + + align:start position:0% +shell and a less than half filed 3D + + + align:start position:0% +shell and a less than half filed 3D +Shell + + align:start position:0% +Shell + + + align:start position:0% +Shell +okay this is an exception that you do + + align:start position:0% +okay this is an exception that you do + + + align:start position:0% +okay this is an exception that you do +have to know + + align:start position:0% +have to know + + + align:start position:0% +have to know +okay okay but after chromium + + align:start position:0% +okay okay but after chromium + + + align:start position:0% +okay okay but after chromium +here + + align:start position:0% +here + + + align:start position:0% +here +uh manganese behaves well iron behaves + + align:start position:0% +uh manganese behaves well iron behaves + + + align:start position:0% +uh manganese behaves well iron behaves +well Cobalt okay nickel okay and now we + + align:start position:0% +well Cobalt okay nickel okay and now we + + + align:start position:0% +well Cobalt okay nickel okay and now we +get to + + align:start position:0% + + + + align:start position:0% + +copper and we got a problem it is not + + align:start position:0% +copper and we got a problem it is not + + + align:start position:0% +copper and we got a problem it is not +what you would expect it is not 4s2 + + align:start position:0% +what you would expect it is not 4s2 + + + align:start position:0% +what you would expect it is not 4s2 +3d9 and instead it's 4s1 + + align:start position:0% +3d9 and instead it's 4s1 + + + align:start position:0% +3d9 and instead it's 4s1 +3d10 okay again this + + align:start position:0% +3d10 okay again this + + + align:start position:0% +3d10 okay again this +configuration is something you couldn't + + align:start position:0% +configuration is something you couldn't + + + align:start position:0% +configuration is something you couldn't +have predicted a priori if you do a + + align:start position:0% +have predicted a priori if you do a + + + align:start position:0% +have predicted a priori if you do a +sophisticated calculation you can see it + + align:start position:0% +sophisticated calculation you can see it + + + align:start position:0% +sophisticated calculation you can see it +but this is also experimentally observed + + align:start position:0% +but this is also experimentally observed + + + align:start position:0% +but this is also experimentally observed +we know this to be the configuration + + align:start position:0% +we know this to be the configuration + + + align:start position:0% +we know this to be the configuration +this is not the + + align:start position:0% +this is not the + + + align:start position:0% +this is not the +configuration all + + align:start position:0% +configuration all + + + align:start position:0% +configuration all +right this is the lower energy + + align:start position:0% +right this is the lower energy + + + align:start position:0% +right this is the lower energy +configuration here's another exception + + align:start position:0% +configuration here's another exception + + + align:start position:0% +configuration here's another exception +that you have to know no + + align:start position:0% +that you have to know no + + + align:start position:0% +that you have to know no +copper + + align:start position:0% +copper + + + align:start position:0% +copper +right okay and then after copper here to + + align:start position:0% +right okay and then after copper here to + + + align:start position:0% +right okay and then after copper here to +zinc Things become follow a pattern + + align:start position:0% +zinc Things become follow a pattern + + + align:start position:0% +zinc Things become follow a pattern +again the next electron then just fills + + align:start position:0% +again the next electron then just fills + + + align:start position:0% +again the next electron then just fills +up the 4s2 + + align:start position:0% +up the 4s2 + + + align:start position:0% +up the 4s2 +3d10 now at gallium all of those are + + align:start position:0% +3d10 now at gallium all of those are + + + align:start position:0% +3d10 now at gallium all of those are +filled we start filling up the four P + + align:start position:0% +filled we start filling up the four P + + + align:start position:0% +filled we start filling up the four P +States all right and everything's fine + + align:start position:0% +States all right and everything's fine + + + align:start position:0% +States all right and everything's fine +until we as we get to Krypton all + + align:start position:0% +until we as we get to Krypton all + + + align:start position:0% +until we as we get to Krypton all +right so you got to know chromium and + + align:start position:0% +right so you got to know chromium and + + + align:start position:0% +right so you got to know chromium and +copper + + align:start position:0% +copper + + + align:start position:0% +copper +now the fifth row here starting with + + align:start position:0% +now the fifth row here starting with + + + align:start position:0% +now the fifth row here starting with +rubidium strum urbium zirconium Etc all + + align:start position:0% +rubidium strum urbium zirconium Etc all + + + align:start position:0% +rubidium strum urbium zirconium Etc all +the way across + + align:start position:0% +the way across + + + align:start position:0% +the way across +here well starting with uh + + align:start position:0% +here well starting with uh + + + align:start position:0% +here well starting with uh +rubidium again the electrons go into the + + align:start position:0% +rubidium again the electrons go into the + + + align:start position:0% +rubidium again the electrons go into the +5S shell they don't go into the 4D and + + align:start position:0% +5S shell they don't go into the 4D and + + + align:start position:0% +5S shell they don't go into the 4D and +that's because with rubidium and + + align:start position:0% +that's because with rubidium and + + + align:start position:0% +that's because with rubidium and +strum 5S is actually lower than 4D + + align:start position:0% +strum 5S is actually lower than 4D + + + align:start position:0% +strum 5S is actually lower than 4D +and it's only once you fill up the 5S + + align:start position:0% +and it's only once you fill up the 5S + + + align:start position:0% +and it's only once you fill up the 5S +states that you start filling up the 4D + + align:start position:0% +states that you start filling up the 4D + + + align:start position:0% +states that you start filling up the 4D +States right here all + + align:start position:0% +States right here all + + + align:start position:0% +States right here all +right now there are exceptions along + + align:start position:0% +right now there are exceptions along + + + align:start position:0% +right now there are exceptions along +this fifth row and the two + + align:start position:0% +this fifth row and the two + + + align:start position:0% +this fifth row and the two +exceptions malum and silver are the same + + align:start position:0% +exceptions malum and silver are the same + + + align:start position:0% +exceptions malum and silver are the same +kind of exceptions as chromium and + + align:start position:0% +kind of exceptions as chromium and + + + align:start position:0% +kind of exceptions as chromium and +copper all right you have to know the + + align:start position:0% +copper all right you have to know the + + + align:start position:0% +copper all right you have to know the +exceptions for silver silver and copper + + align:start position:0% +exceptions for silver silver and copper + + + align:start position:0% +exceptions for silver silver and copper +and maliban and chromium all right the + + align:start position:0% +and maliban and chromium all right the + + + align:start position:0% +and maliban and chromium all right the +same identical kind of exception as in + + align:start position:0% +same identical kind of exception as in + + + align:start position:0% +same identical kind of exception as in +the fourth row here there are other + + align:start position:0% +the fourth row here there are other + + + align:start position:0% +the fourth row here there are other +exceptions along this fifth row you + + align:start position:0% +exceptions along this fifth row you + + + align:start position:0% +exceptions along this fifth row you +don't have to know those there's really + + align:start position:0% +don't have to know those there's really + + + align:start position:0% +don't have to know those there's really +no way a priori for you to know that + + align:start position:0% +no way a priori for you to know that + + + align:start position:0% +no way a priori for you to know that +again it's an experimental observation a + + align:start position:0% +again it's an experimental observation a + + + align:start position:0% +again it's an experimental observation a +sophisticated hard calculation will also + + align:start position:0% +sophisticated hard calculation will also + + + align:start position:0% +sophisticated hard calculation will also +show that all right + + align:start position:0% +show that all right + + + align:start position:0% +show that all right +okay and then once you're done with + + align:start position:0% +okay and then once you're done with + + + align:start position:0% +okay and then once you're done with +cadmium well then the 5ps start filling + + align:start position:0% +cadmium well then the 5ps start filling + + + align:start position:0% +cadmium well then the 5ps start filling +and everything's normal and you get to + + align:start position:0% +and everything's normal and you get to + + + align:start position:0% +and everything's normal and you get to +the Xenon inner gas + + align:start position:0% +the Xenon inner gas + + + align:start position:0% +the Xenon inner gas +configuration + + align:start position:0% +configuration + + + align:start position:0% +configuration +okay + + align:start position:0% + + + + align:start position:0% + +okay okay now how do you uh remember + + align:start position:0% +okay okay now how do you uh remember + + + align:start position:0% +okay okay now how do you uh remember +what the ordering is of these uh States + + align:start position:0% +what the ordering is of these uh States + + + align:start position:0% +what the ordering is of these uh States +the energy ordering well here's a + + align:start position:0% +the energy ordering well here's a + + + align:start position:0% +the energy ordering well here's a +pneumonic that + + align:start position:0% +pneumonic that + + + align:start position:0% +pneumonic that +maybe some of you have uh seen + + align:start position:0% +maybe some of you have uh seen + + + align:start position:0% +maybe some of you have uh seen +before but uh start out write one s then + + align:start position:0% +before but uh start out write one s then + + + align:start position:0% +before but uh start out write one s then +write 2 s right below it and then 2 p to + + align:start position:0% +write 2 s right below it and then 2 p to + + + align:start position:0% +write 2 s right below it and then 2 p to +the side of it and then write 3s 3p + + align:start position:0% +the side of it and then write 3s 3p + + + align:start position:0% +the side of it and then write 3s 3p +3D and then write 4S 4 P 4D + + align:start position:0% +3D and then write 4S 4 P 4D + + + align:start position:0% +3D and then write 4S 4 P 4D +4f and then write 5S 5 P 5D 5f and 6s 6 + + align:start position:0% +4f and then write 5S 5 P 5D 5f and 6s 6 + + + align:start position:0% +4f and then write 5S 5 P 5D 5f and 6s 6 +P 6D and 7s + + align:start position:0% +P 6D and 7s + + + align:start position:0% +P 6D and 7s +7p and now to get the energy ordering + + align:start position:0% +7p and now to get the energy ordering + + + align:start position:0% +7p and now to get the energy ordering +we're going to draw diagonals well first + + align:start position:0% +we're going to draw diagonals well first + + + align:start position:0% +we're going to draw diagonals well first +of all the 1 s is the lowest energy + + align:start position:0% +of all the 1 s is the lowest energy + + + align:start position:0% +of all the 1 s is the lowest energy +State and then the next highest energy + + align:start position:0% +State and then the next highest energy + + + align:start position:0% +State and then the next highest energy +state is the 2s + + align:start position:0% +state is the 2s + + + align:start position:0% +state is the 2s +State and then the next highest energy + + align:start position:0% +State and then the next highest energy + + + align:start position:0% +State and then the next highest energy +state is the 2p so we're going to draw a + + align:start position:0% +state is the 2p so we're going to draw a + + + align:start position:0% +state is the 2p so we're going to draw a +diagonal so the next state to fill is 2p + + align:start position:0% +diagonal so the next state to fill is 2p + + + align:start position:0% +diagonal so the next state to fill is 2p +the next one is + + align:start position:0% +the next one is + + + align:start position:0% +the next one is +3s now we're going to draw a diagonal + + align:start position:0% +3s now we're going to draw a diagonal + + + align:start position:0% +3s now we're going to draw a diagonal +again the next one to fill is + + align:start position:0% +again the next one to fill is + + + align:start position:0% +again the next one to fill is +3p the next one to fill is + + align:start position:0% +3p the next one to fill is + + + align:start position:0% +3p the next one to fill is +4S draw another diagonal next one to + + align:start position:0% +4S draw another diagonal next one to + + + align:start position:0% +4S draw another diagonal next one to +fill is 3D 4 P + + align:start position:0% +fill is 3D 4 P + + + align:start position:0% +fill is 3D 4 P +5S 4D 5p 6s 4f 5D 6p 7s 5S 6D 7p and + + align:start position:0% +5S 4D 5p 6s 4f 5D 6p 7s 5S 6D 7p and + + + align:start position:0% +5S 4D 5p 6s 4f 5D 6p 7s 5S 6D 7p and +that's all that's going to be important + + align:start position:0% +that's all that's going to be important + + + align:start position:0% +that's all that's going to be important +all right so that's one way to remember + + align:start position:0% +all right so that's one way to remember + + + align:start position:0% +all right so that's one way to remember +the relative energy orderings here and + + align:start position:0% +the relative energy orderings here and + + + align:start position:0% +the relative energy orderings here and +you do have to be able to write this + + align:start position:0% +you do have to be able to write this + + + align:start position:0% +you do have to be able to write this +down on an exam okay without you'll have + + align:start position:0% +down on an exam okay without you'll have + + + align:start position:0% +down on an exam okay without you'll have +a periodic table but it won't have the + + align:start position:0% +a periodic table but it won't have the + + + align:start position:0% +a periodic table but it won't have the +electron configurations on it okay + + align:start position:0% +electron configurations on it okay + + + align:start position:0% +electron configurations on it okay +okay now I want to tell you something + + align:start position:0% +okay now I want to tell you something + + + align:start position:0% +okay now I want to tell you something +that uh sometimes people find uh a + + align:start position:0% +that uh sometimes people find uh a + + + align:start position:0% +that uh sometimes people find uh a +little bit + + align:start position:0% + + + + align:start position:0% + +confusing and that is uh the electron + + align:start position:0% +confusing and that is uh the electron + + + align:start position:0% +confusing and that is uh the electron +configuration of + + align:start position:0% +configuration of + + + align:start position:0% +configuration of +ions what I'm about to say has no effect + + align:start position:0% +ions what I'm about to say has no effect + + + align:start position:0% +ions what I'm about to say has no effect +on what I just said about how to write + + align:start position:0% +on what I just said about how to write + + + align:start position:0% +on what I just said about how to write +the electron configuration for + + align:start position:0% +the electron configuration for + + + align:start position:0% +the electron configuration for +neutrals okay this does not affect + + align:start position:0% +neutrals okay this does not affect + + + align:start position:0% +neutrals okay this does not affect +anything in your writing down the + + align:start position:0% +anything in your writing down the + + + align:start position:0% +anything in your writing down the +electron configuration for neutrals this + + align:start position:0% +electron configuration for neutrals this + + + align:start position:0% +electron configuration for neutrals this +is for + + align:start position:0% +is for + + + align:start position:0% +is for +ions okay but the point I want to make + + align:start position:0% +ions okay but the point I want to make + + + align:start position:0% +ions okay but the point I want to make +is that if you actually look at the + + align:start position:0% +is that if you actually look at the + + + align:start position:0% +is that if you actually look at the +energies of the individual 3D States and + + align:start position:0% +energies of the individual 3D States and + + + align:start position:0% +energies of the individual 3D States and +4S States + + align:start position:0% +4S States + + + align:start position:0% +4S States +across that fourth row this is what they + + align:start position:0% +across that fourth row this is what they + + + align:start position:0% +across that fourth row this is what they +look like so for + + align:start position:0% +look like so for + + + align:start position:0% +look like so for +example at pottassium that 4S state is + + align:start position:0% +example at pottassium that 4S state is + + + align:start position:0% +example at pottassium that 4S state is +lower in energy than the 3D State that's + + align:start position:0% +lower in energy than the 3D State that's + + + align:start position:0% +lower in energy than the 3D State that's +why we put the electron in the 4S State + + align:start position:0% +why we put the electron in the 4S State + + + align:start position:0% +why we put the electron in the 4S State +when we wrote the + + align:start position:0% +when we wrote the + + + align:start position:0% +when we wrote the +neutral and the same thing for calcium + + align:start position:0% +neutral and the same thing for calcium + + + align:start position:0% +neutral and the same thing for calcium +that's why we put that electron into the + + align:start position:0% +that's why we put that electron into the + + + align:start position:0% +that's why we put that electron into the +4S State and not the 3s + + align:start position:0% +4S State and not the 3s + + + align:start position:0% +4S State and not the 3s +state but lo and behold right here at + + align:start position:0% +state but lo and behold right here at + + + align:start position:0% +state but lo and behold right here at +Scandium Z equal + + align:start position:0% +Scandium Z equal + + + align:start position:0% +Scandium Z equal +21 what happens is that the 3D State + + align:start position:0% +21 what happens is that the 3D State + + + align:start position:0% +21 what happens is that the 3D State +actually drops below an energy than the + + align:start position:0% +actually drops below an energy than the + + + align:start position:0% +actually drops below an energy than the +4S State these are the energies of the + + align:start position:0% +4S State these are the energies of the + + + align:start position:0% +4S State these are the energies of the +individual State now + + align:start position:0% +individual State now + + + align:start position:0% +individual State now +okay and that continues all the way + + align:start position:0% +okay and that continues all the way + + + align:start position:0% +okay and that continues all the way +across the periodic + + align:start position:0% +across the periodic + + + align:start position:0% +across the periodic +table however that does not affect how + + align:start position:0% +table however that does not affect how + + + align:start position:0% +table however that does not affect how +you write the electron configuration of + + align:start position:0% +you write the electron configuration of + + + align:start position:0% +you write the electron configuration of +the neutrals so so for example if you're + + align:start position:0% +the neutrals so so for example if you're + + + align:start position:0% +the neutrals so so for example if you're +writing the electron configuration for + + align:start position:0% +writing the electron configuration for + + + align:start position:0% +writing the electron configuration for +titanium here it is it's the Argon core + + align:start position:0% +titanium here it is it's the Argon core + + + align:start position:0% +titanium here it is it's the Argon core +4s2 + + align:start position:0% +4s2 + + + align:start position:0% +4s2 +3d2 okay and by the way I don't care + + align:start position:0% +3d2 okay and by the way I don't care + + + align:start position:0% +3d2 okay and by the way I don't care +whether you write 3d2 4s2 or 4s2 + + align:start position:0% +whether you write 3d2 4s2 or 4s2 + + + align:start position:0% +whether you write 3d2 4s2 or 4s2 +3d2 okay you can write them in either + + align:start position:0% + + + + align:start position:0% + +order all right now you might say well + + align:start position:0% +order all right now you might say well + + + align:start position:0% +order all right now you might say well +why is this the electron configuration + + align:start position:0% +why is this the electron configuration + + + align:start position:0% +why is this the electron configuration +if at this value for z z equal 22 + + align:start position:0% +if at this value for z z equal 22 + + + align:start position:0% +if at this value for z z equal 22 +titanium the 3D state is lower than the + + align:start position:0% +titanium the 3D state is lower than the + + + align:start position:0% +titanium the 3D state is lower than the +4S State why don't these 4S electrons + + align:start position:0% +4S State why don't these 4S electrons + + + align:start position:0% +4S State why don't these 4S electrons +just hop into the 3D + + align:start position:0% +just hop into the 3D + + + align:start position:0% +just hop into the 3D +States well they don't do that they + + align:start position:0% +States well they don't do that they + + + align:start position:0% +States well they don't do that they +don't do that because this electron + + align:start position:0% +don't do that because this electron + + + align:start position:0% +don't do that because this electron +configuration actually minimizes the + + align:start position:0% +configuration actually minimizes the + + + align:start position:0% +configuration actually minimizes the +electron + + align:start position:0% +electron + + + align:start position:0% +electron +repulsions if these four electrons were + + align:start position:0% +repulsions if these four electrons were + + + align:start position:0% +repulsions if these four electrons were +in the 3D + + align:start position:0% +in the 3D + + + align:start position:0% +in the 3D +State well then the repulsive + + align:start position:0% +State well then the repulsive + + + align:start position:0% +State well then the repulsive +interactions would be greater because + + align:start position:0% +interactions would be greater because + + + align:start position:0% +interactions would be greater because +they're in the same state + + align:start position:0% +they're in the same state + + + align:start position:0% +they're in the same state +now and therefore the entire energy of + + align:start position:0% +now and therefore the entire energy of + + + align:start position:0% +now and therefore the entire energy of +the of the atom will be larger all right + + align:start position:0% +the of the atom will be larger all right + + + align:start position:0% +the of the atom will be larger all right +and it is the entire energy the the + + align:start position:0% +and it is the entire energy the the + + + align:start position:0% +and it is the entire energy the the +total energy of the atom that's + + align:start position:0% +total energy of the atom that's + + + align:start position:0% +total energy of the atom that's +important when we look at the electron + + align:start position:0% +important when we look at the electron + + + align:start position:0% +important when we look at the electron +configurations in this particular case + + align:start position:0% +configurations in this particular case + + + align:start position:0% +configurations in this particular case +if we look at the individual D States + + align:start position:0% +if we look at the individual D States + + + align:start position:0% +if we look at the individual D States +and the four S States yeah the D states + + align:start position:0% +and the four S States yeah the D states + + + align:start position:0% +and the four S States yeah the D states +are lower in + + align:start position:0% +are lower in + + + align:start position:0% +are lower in +energy but what's important is when we + + align:start position:0% +energy but what's important is when we + + + align:start position:0% +energy but what's important is when we +sum up all of the energies of the + + align:start position:0% +sum up all of the energies of the + + + align:start position:0% +sum up all of the energies of the +interactions what is lower and what I'm + + align:start position:0% +interactions what is lower and what I'm + + + align:start position:0% +interactions what is lower and what I'm +saying to you is that when we do that + + align:start position:0% +saying to you is that when we do that + + + align:start position:0% +saying to you is that when we do that +when we sum up all of the interaction + + align:start position:0% +when we sum up all of the interaction + + + align:start position:0% +when we sum up all of the interaction +energies this still is the lower energy + + align:start position:0% +energies this still is the lower energy + + + align:start position:0% +energies this still is the lower energy +configuration even though the 3D + + align:start position:0% +configuration even though the 3D + + + align:start position:0% +configuration even though the 3D +electrons at this value of Z are those + + align:start position:0% +electrons at this value of Z are those + + + align:start position:0% +electrons at this value of Z are those +3D states are lower and energy than the + + align:start position:0% +3D states are lower and energy than the + + + align:start position:0% +3D states are lower and energy than the +4S States okay so that's why we don't + + align:start position:0% +4S States okay so that's why we don't + + + align:start position:0% +4S States okay so that's why we don't +have this hopping over into the 3D + + align:start position:0% +have this hopping over into the 3D + + + align:start position:0% +have this hopping over into the 3D +States for the + + align:start position:0% +States for the + + + align:start position:0% +States for the +neutral but now here comes the ion + + align:start position:0% +neutral but now here comes the ion + + + align:start position:0% +neutral but now here comes the ion +configuration if you have this + + align:start position:0% +configuration if you have this + + + align:start position:0% +configuration if you have this +configuration for the + + align:start position:0% +configuration for the + + + align:start position:0% +configuration for the +neutral and now you ionize titanium to + + align:start position:0% +neutral and now you ionize titanium to + + + align:start position:0% +neutral and now you ionize titanium to +make titanium + + align:start position:0% +make titanium + + + align:start position:0% +make titanium +plus the electron configuration is argon + + align:start position:0% +plus the electron configuration is argon + + + align:start position:0% +plus the electron configuration is argon +3d2 that that is it's the 4S electrons + + align:start position:0% +3d2 that that is it's the 4S electrons + + + align:start position:0% +3d2 that that is it's the 4S electrons +that come off that are plucked out right + + align:start position:0% +that come off that are plucked out right + + + align:start position:0% +that come off that are plucked out right +they're plucked out because they're the + + align:start position:0% +they're plucked out because they're the + + + align:start position:0% +they're plucked out because they're the +higher energy electrons + + align:start position:0% +higher energy electrons + + + align:start position:0% +higher energy electrons +now okay so this is the electron + + align:start position:0% +now okay so this is the electron + + + align:start position:0% +now okay so this is the electron +configuration for titanium plus 2 so + + align:start position:0% +configuration for titanium plus 2 so + + + align:start position:0% +configuration for titanium plus 2 so +we're going to pull out those higher + + align:start position:0% +we're going to pull out those higher + + + align:start position:0% +we're going to pull out those higher +energy electrons which are the 4S + + align:start position:0% +energy electrons which are the 4S + + + align:start position:0% +energy electrons which are the 4S +electrons and again this affects only + + align:start position:0% +electrons and again this affects only + + + align:start position:0% +electrons and again this affects only +the ion configuration + + align:start position:0% +the ion configuration + + + align:start position:0% +the ion configuration +same thing happens here on the fifth + + align:start position:0% +same thing happens here on the fifth + + + align:start position:0% +same thing happens here on the fifth +Row the fifth row starting here with + + align:start position:0% +Row the fifth row starting here with + + + align:start position:0% +Row the fifth row starting here with +rubidium and + + align:start position:0% +rubidium and + + + align:start position:0% +rubidium and +strum 5S is lower in energy than 4D + + align:start position:0% +strum 5S is lower in energy than 4D + + + align:start position:0% +strum 5S is lower in energy than 4D +that's why that rubidium electron went + + align:start position:0% +that's why that rubidium electron went + + + align:start position:0% +that's why that rubidium electron went +in the 5S State same thing with the + + align:start position:0% +in the 5S State same thing with the + + + align:start position:0% +in the 5S State same thing with the +strum electron went in the 5S state but + + align:start position:0% +strum electron went in the 5S state but + + + align:start position:0% +strum electron went in the 5S state but +right here at + + align:start position:0% +right here at + + + align:start position:0% +right here at +ubium the 4D State goes Below in energy + + align:start position:0% +ubium the 4D State goes Below in energy + + + align:start position:0% +ubium the 4D State goes Below in energy +the 5S + + align:start position:0% +the 5S + + + align:start position:0% +the 5S +State again that does not affect how you + + align:start position:0% +State again that does not affect how you + + + align:start position:0% +State again that does not affect how you +write the electron configuration of the + + align:start position:0% +write the electron configuration of the + + + align:start position:0% +write the electron configuration of the +neutral so for + + align:start position:0% +neutral so for + + + align:start position:0% +neutral so for +example silver which is way out here and + + align:start position:0% +example silver which is way out here and + + + align:start position:0% +example silver which is way out here and +which is one of those + + align:start position:0% +which is one of those + + + align:start position:0% +which is one of those +exceptions okay silver if you ionize it + + align:start position:0% +exceptions okay silver if you ionize it + + + align:start position:0% +exceptions okay silver if you ionize it +if you pluck off an electron from Silver + + align:start position:0% +if you pluck off an electron from Silver + + + align:start position:0% +if you pluck off an electron from Silver +which electron is going to go 5s and so + + align:start position:0% +which electron is going to go 5s and so + + + align:start position:0% +which electron is going to go 5s and so +the tip silver plus one electron + + align:start position:0% +the tip silver plus one electron + + + align:start position:0% +the tip silver plus one electron +configuration is the Krypton core 4 d10 + + align:start position:0% +configuration is the Krypton core 4 d10 + + + align:start position:0% +configuration is the Krypton core 4 d10 +it's that 5S electron that's going to uh + + align:start position:0% +it's that 5S electron that's going to uh + + + align:start position:0% +it's that 5S electron that's going to uh +disappear okay so this is important + + align:start position:0% +disappear okay so this is important + + + align:start position:0% +disappear okay so this is important +don't let it confuse you with the + + align:start position:0% +don't let it confuse you with the + + + align:start position:0% +don't let it confuse you with the +writing the electron configurations of + + align:start position:0% +writing the electron configurations of + + + align:start position:0% +writing the electron configurations of +the + + align:start position:0% +the + + + align:start position:0% +the +neutrals all + + align:start position:0% +neutrals all + + + align:start position:0% +neutrals all +right okie + + align:start position:0% +right okie + + + align:start position:0% +right okie +dokie see you Friday + + align:start position:0% + + + + align:start position:0% + +[Applause] \ No newline at end of file diff --git a/KXof0q88xbg.txt b/KXof0q88xbg.txt new file mode 100644 index 0000000000000000000000000000000000000000..a1543065f1883bee7eb0110bd75793661631efa6 --- /dev/null +++ b/KXof0q88xbg.txt @@ -0,0 +1,1643 @@ +align:start position:0% + +welcome back to recitation in this video + + align:start position:0% +welcome back to recitation in this video + + + align:start position:0% +welcome back to recitation in this video +what I'd like you to do is use Green's + + align:start position:0% +what I'd like you to do is use Green's + + + align:start position:0% +what I'd like you to do is use Green's +theorem to find the area between one + + align:start position:0% +theorem to find the area between one + + + align:start position:0% +theorem to find the area between one +arch of the cyllid that is described by + + align:start position:0% +arch of the cyllid that is described by + + + align:start position:0% +arch of the cyllid that is described by +x = a * thean thetus sin Theta y = a * + + align:start position:0% +x = a * thean thetus sin Theta y = a * + + + align:start position:0% +x = a * thean thetus sin Theta y = a * +thean 1 - cosine Theta and the x-axis so + + align:start position:0% +thean 1 - cosine Theta and the x-axis so + + + align:start position:0% +thean 1 - cosine Theta and the x-axis so +probably it's helpful for you to draw a + + align:start position:0% +probably it's helpful for you to draw a + + + align:start position:0% +probably it's helpful for you to draw a +picture of this first so you have one + + align:start position:0% +picture of this first so you have one + + + align:start position:0% +picture of this first so you have one +arch of the C + + align:start position:0% +arch of the C + + + align:start position:0% +arch of the C +defined uh in terms of theta the X the x + + align:start position:0% +defined uh in terms of theta the X the x + + + align:start position:0% +defined uh in terms of theta the X the x +of theta and Y of theta are here and + + align:start position:0% +of theta and Y of theta are here and + + + align:start position:0% +of theta and Y of theta are here and +then the x axis will be the other bound + + align:start position:0% +then the x axis will be the other bound + + + align:start position:0% +then the x axis will be the other bound +and the big thing I want you to notice + + align:start position:0% +and the big thing I want you to notice + + + align:start position:0% +and the big thing I want you to notice +is you're going to use Green's theorem + + align:start position:0% +is you're going to use Green's theorem + + + align:start position:0% +is you're going to use Green's theorem +to find the area so why don't you pause + + align:start position:0% +to find the area so why don't you pause + + + align:start position:0% +to find the area so why don't you pause +the video work on the problem when + + align:start position:0% +the video work on the problem when + + + align:start position:0% +the video work on the problem when +you're ready to see my solution you can + + align:start position:0% +you're ready to see my solution you can + + + align:start position:0% +you're ready to see my solution you can +bring the video back + + align:start position:0% + + + + align:start position:0% + +up okay welcome back so again what we + + align:start position:0% +up okay welcome back so again what we + + + align:start position:0% +up okay welcome back so again what we +want to do is we want to use green + + align:start position:0% +want to do is we want to use green + + + align:start position:0% +want to do is we want to use green +theorem to find an area okay and what + + align:start position:0% +theorem to find an area okay and what + + + align:start position:0% +theorem to find an area okay and what +I'm going to do first is I'm going to + + align:start position:0% +I'm going to do first is I'm going to + + + align:start position:0% +I'm going to do first is I'm going to +try and figure out what the picture + + align:start position:0% +try and figure out what the picture + + + align:start position:0% +try and figure out what the picture +looks like and then I'm going to figure + + align:start position:0% +looks like and then I'm going to figure + + + align:start position:0% +looks like and then I'm going to figure +out how to use green theorem in this in + + align:start position:0% +out how to use green theorem in this in + + + align:start position:0% +out how to use green theorem in this in +this region okay so let's first draw a + + align:start position:0% +this region okay so let's first draw a + + + align:start position:0% +this region okay so let's first draw a +sketch of the picture of what's going on + + align:start position:0% +sketch of the picture of what's going on + + + align:start position:0% +sketch of the picture of what's going on +and because I want the area between one + + align:start position:0% +and because I want the area between one + + + align:start position:0% +and because I want the area between one +arch of the cyllid and the x-axis what I + + align:start position:0% +arch of the cyllid and the x-axis what I + + + align:start position:0% +arch of the cyllid and the x-axis what I +really want to do first is figure out um + + align:start position:0% +really want to do first is figure out um + + + align:start position:0% +really want to do first is figure out um +what y value what Theta values will make + + align:start position:0% +what y value what Theta values will make + + + align:start position:0% +what y value what Theta values will make +y positive or greater than or equal to + + align:start position:0% +y positive or greater than or equal to + + + align:start position:0% +y positive or greater than or equal to +zero and go for from there so if I want + + align:start position:0% +zero and go for from there so if I want + + + align:start position:0% +zero and go for from there so if I want +y to be greater than or equal to + + align:start position:0% +y to be greater than or equal to + + + align:start position:0% +y to be greater than or equal to +zero then what I need is 1 - cosine + + align:start position:0% +zero then what I need is 1 - cosine + + + align:start position:0% +zero then what I need is 1 - cosine +Theta to be greater than or equal to + + align:start position:0% +Theta to be greater than or equal to + + + align:start position:0% +Theta to be greater than or equal to +zero okay and that's going to happen for + + align:start position:0% +zero okay and that's going to happen for + + + align:start position:0% +zero okay and that's going to happen for +every Theta from 0 to 2 pi and at0 and 2 + + align:start position:0% +every Theta from 0 to 2 pi and at0 and 2 + + + align:start position:0% +every Theta from 0 to 2 pi and at0 and 2 +pi I get zero so we know we want Theta + + align:start position:0% +pi I get zero so we know we want Theta + + + align:start position:0% +pi I get zero so we know we want Theta +to go between 0o and 2 + + align:start position:0% +to go between 0o and 2 + + + align:start position:0% +to go between 0o and 2 +pi that that's a good those are good + + align:start position:0% +pi that that's a good those are good + + + align:start position:0% +pi that that's a good those are good +parameters to have for Theta because + + align:start position:0% +parameters to have for Theta because + + + align:start position:0% +parameters to have for Theta because +this statement is always true but I get + + align:start position:0% +this statement is always true but I get + + + align:start position:0% +this statement is always true but I get +zero when Theta is zero and when Theta + + align:start position:0% +zero when Theta is zero and when Theta + + + align:start position:0% +zero when Theta is zero and when Theta +is 2 pi so I'm going to let Theta run + + align:start position:0% +is 2 pi so I'm going to let Theta run + + + align:start position:0% +is 2 pi so I'm going to let Theta run +between 0 and 2 pi as I mentioned okay + + align:start position:0% +between 0 and 2 pi as I mentioned okay + + + align:start position:0% +between 0 and 2 pi as I mentioned okay +so now let's think about what the + + align:start position:0% +so now let's think about what the + + + align:start position:0% +so now let's think about what the +picture is when Theta is zero if I come + + align:start position:0% +picture is when Theta is zero if I come + + + align:start position:0% +picture is when Theta is zero if I come +over to what x + + align:start position:0% +over to what x + + + align:start position:0% +over to what x +is X is a * 0 - 0 so x is 0 and Y we + + align:start position:0% +is X is a * 0 - 0 so x is 0 and Y we + + + align:start position:0% +is X is a * 0 - 0 so x is 0 and Y we +said was Zero + + align:start position:0% +said was Zero + + + align:start position:0% +said was Zero +okay I know that I'll achieve a maximum + + align:start position:0% +okay I know that I'll achieve a maximum + + + align:start position:0% +okay I know that I'll achieve a maximum +height at Theta equal Pi because that's + + align:start position:0% +height at Theta equal Pi because that's + + + align:start position:0% +height at Theta equal Pi because that's +where cosine Theta is minus 1 so the 1 - + + align:start position:0% +where cosine Theta is minus 1 so the 1 - + + + align:start position:0% +where cosine Theta is minus 1 so the 1 - +cosine Theta is 2 + + align:start position:0% +cosine Theta is 2 + + + align:start position:0% +cosine Theta is 2 +and so if you look at what the Y value + + align:start position:0% +and so if you look at what the Y value + + + align:start position:0% +and so if you look at what the Y value +will be the Y value when Theta is pi is + + align:start position:0% +will be the Y value when Theta is pi is + + + align:start position:0% +will be the Y value when Theta is pi is +2 a and the x value is going to be a * + + align:start position:0% +2 a and the x value is going to be a * + + + align:start position:0% +2 a and the x value is going to be a * +pi minus sin Pi well s of Pi is zero so + + align:start position:0% +pi minus sin Pi well s of Pi is zero so + + + align:start position:0% +pi minus sin Pi well s of Pi is zero so +I just get a pi so I should go over a pi + + align:start position:0% +I just get a pi so I should go over a pi + + + align:start position:0% +I just get a pi so I should go over a pi +and I know there's a point at a pi comma + + align:start position:0% +and I know there's a point at a pi comma + + + align:start position:0% +and I know there's a point at a pi comma +I think I said 2 a + + align:start position:0% +I think I said 2 a + + + align:start position:0% +I think I said 2 a +right and then it's actually going to + + align:start position:0% +right and then it's actually going to + + + align:start position:0% +right and then it's actually going to +come back down the same way so let me + + align:start position:0% +come back down the same way so let me + + + align:start position:0% +come back down the same way so let me +draw the first part this is not a + + align:start position:0% +draw the first part this is not a + + + align:start position:0% +draw the first part this is not a +perfect drawing of this I don't have + + align:start position:0% +perfect drawing of this I don't have + + + align:start position:0% +perfect drawing of this I don't have +lots of points I'm having the smallest + + align:start position:0% +lots of points I'm having the smallest + + + align:start position:0% +lots of points I'm having the smallest +amount of points possible to figure out + + align:start position:0% +amount of points possible to figure out + + + align:start position:0% +amount of points possible to figure out +what's happening okay so then when Theta + + align:start position:0% +what's happening okay so then when Theta + + + align:start position:0% +what's happening okay so then when Theta +is 2 pi 1 - cosine Theta is is zero so I + + align:start position:0% +is 2 pi 1 - cosine Theta is is zero so I + + + align:start position:0% +is 2 pi 1 - cosine Theta is is zero so I +get here I get y equal 0 and then here I + + align:start position:0% +get here I get y equal 0 and then here I + + + align:start position:0% +get here I get y equal 0 and then here I +get 2 pi minus s of 2 pi s of 2 pi is + + align:start position:0% +get 2 pi minus s of 2 pi s of 2 pi is + + + align:start position:0% +get 2 pi minus s of 2 pi s of 2 pi is +Zer so I get 2 pi a so I come all the + + align:start position:0% +Zer so I get 2 pi a so I come all the + + + align:start position:0% +Zer so I get 2 pi a so I come all the +way over here and I get 2 pi + + align:start position:0% +way over here and I get 2 pi + + + align:start position:0% +way over here and I get 2 pi +a so this is yeah that's not maybe the + + align:start position:0% +a so this is yeah that's not maybe the + + + align:start position:0% +a so this is yeah that's not maybe the +most beautiful picture but it's a good + + align:start position:0% +most beautiful picture but it's a good + + + align:start position:0% +most beautiful picture but it's a good +it's a good start and so I'm interested + + align:start position:0% +it's a good start and so I'm interested + + + align:start position:0% +it's a good start and so I'm interested +in finding the area of this + + align:start position:0% +in finding the area of this + + + align:start position:0% +in finding the area of this +region right and what I want to do then + + align:start position:0% +region right and what I want to do then + + + align:start position:0% +region right and what I want to do then +is to find the area of that region I am + + align:start position:0% +is to find the area of that region I am + + + align:start position:0% +is to find the area of that region I am +going to use green theorem that's what + + align:start position:0% +going to use green theorem that's what + + + align:start position:0% +going to use green theorem that's what +we asked you to do so what I want to do + + align:start position:0% +we asked you to do so what I want to do + + + align:start position:0% +we asked you to do so what I want to do +is I want to pick a curve that's going + + align:start position:0% +is I want to pick a curve that's going + + + align:start position:0% +is I want to pick a curve that's going +to have two components it's going to + + align:start position:0% +to have two components it's going to + + + align:start position:0% +to have two components it's going to +have C1 will be this bottom part and C2 + + align:start position:0% +have C1 will be this bottom part and C2 + + + align:start position:0% +have C1 will be this bottom part and C2 +will be this top part and I need to keep + + align:start position:0% +will be this top part and I need to keep + + + align:start position:0% +will be this top part and I need to keep +it oriented so I when I'm walking along + + align:start position:0% +it oriented so I when I'm walking along + + + align:start position:0% +it oriented so I when I'm walking along +the curve the region is on the left + + align:start position:0% +the curve the region is on the left + + + align:start position:0% +the curve the region is on the left +right and then I have to figure out how + + align:start position:0% +right and then I have to figure out how + + + align:start position:0% +right and then I have to figure out how +to use green the + + align:start position:0% +to use green the + + + align:start position:0% +to use green the +so to find the area of this region all I + + align:start position:0% +so to find the area of this region all I + + + align:start position:0% +so to find the area of this region all I +actually need is the integral over the + + align:start position:0% +actually need is the integral over the + + + align:start position:0% +actually need is the integral over the +region of Da right that would give me + + align:start position:0% +region of Da right that would give me + + + align:start position:0% +region of Da right that would give me +the area and so what quantities would + + align:start position:0% +the area and so what quantities would + + + align:start position:0% +the area and so what quantities would +that would would be uh what good what + + align:start position:0% +that would would be uh what good what + + + align:start position:0% +that would would be uh what good what +functions would be good sorry in order + + align:start position:0% +functions would be good sorry in order + + + align:start position:0% +functions would be good sorry in order +to find this well I believe you actually + + align:start position:0% +to find this well I believe you actually + + + align:start position:0% +to find this well I believe you actually +saw in class that you have two options + + align:start position:0% +saw in class that you have two options + + + align:start position:0% +saw in class that you have two options +you have minus + + align:start position:0% +you have minus + + + align:start position:0% +you have minus +ydx over the curve closed curve or you + + align:start position:0% +ydx over the curve closed curve or you + + + align:start position:0% +ydx over the curve closed curve or you +have uh xdy over the closed curve curve + + align:start position:0% +have uh xdy over the closed curve curve + + + align:start position:0% +have uh xdy over the closed curve curve +you have one of those two options okay + + align:start position:0% +you have one of those two options okay + + + align:start position:0% +you have one of those two options okay +now which one of those is better in this + + align:start position:0% +now which one of those is better in this + + + align:start position:0% +now which one of those is better in this +case we have a choice so let's make the + + align:start position:0% +case we have a choice so let's make the + + + align:start position:0% +case we have a choice so let's make the +best choice which one of those is better + + align:start position:0% +best choice which one of those is better + + + align:start position:0% +best choice which one of those is better +well if you notice that that on these + + align:start position:0% +well if you notice that that on these + + + align:start position:0% +well if you notice that that on these +two curves X is changing on both of them + + align:start position:0% +two curves X is changing on both of them + + + align:start position:0% +two curves X is changing on both of them +but Y is fixed on this one so it' be + + align:start position:0% +but Y is fixed on this one so it' be + + + align:start position:0% +but Y is fixed on this one so it' be +nicer for us if we could just if we + + align:start position:0% +nicer for us if we could just if we + + + align:start position:0% +nicer for us if we could just if we +could just integrate on the curve on + + align:start position:0% +could just integrate on the curve on + + + align:start position:0% +could just integrate on the curve on +this part which we would be able to do + + align:start position:0% +this part which we would be able to do + + + align:start position:0% +this part which we would be able to do +if we were choosing this one right + + align:start position:0% +if we were choosing this one right + + + align:start position:0% +if we were choosing this one right +because Y is constant and it is equal to + + align:start position:0% +because Y is constant and it is equal to + + + align:start position:0% +because Y is constant and it is equal to +zero along here okay so what you need to + + align:start position:0% +zero along here okay so what you need to + + + align:start position:0% +zero along here okay so what you need to +do to solve this problem is really you + + align:start position:0% +do to solve this problem is really you + + + align:start position:0% +do to solve this problem is really you +only need to integrate on + + align:start position:0% +only need to integrate on + + + align:start position:0% +only need to integrate on +C2 uh minus y DX that's going to give + + align:start position:0% +C2 uh minus y DX that's going to give + + + align:start position:0% +C2 uh minus y DX that's going to give +you the entire + + align:start position:0% +you the entire + + + align:start position:0% +you the entire +area and so now we have to figure out + + align:start position:0% +area and so now we have to figure out + + + align:start position:0% +area and so now we have to figure out +how to put everything in right well C2 I + + align:start position:0% +how to put everything in right well C2 I + + + align:start position:0% +how to put everything in right well C2 I +should parameterize I'm parameterized in + + align:start position:0% +should parameterize I'm parameterized in + + + align:start position:0% +should parameterize I'm parameterized in +Theta right and C2 parameterized in + + align:start position:0% +Theta right and C2 parameterized in + + + align:start position:0% +Theta right and C2 parameterized in +Theta if I start here I'm at 2 pi for + + align:start position:0% +Theta if I start here I'm at 2 pi for + + + align:start position:0% +Theta if I start here I'm at 2 pi for +Theta and if I go this direction I'm at + + align:start position:0% +Theta and if I go this direction I'm at + + + align:start position:0% +Theta and if I go this direction I'm at +zero for Theta so what I'm going to do + + align:start position:0% +zero for Theta so what I'm going to do + + + align:start position:0% +zero for Theta so what I'm going to do +is I'm going to do something that might + + align:start position:0% +is I'm going to do something that might + + + align:start position:0% +is I'm going to do something that might +seem tricky but it's quite natural I'm + + align:start position:0% +seem tricky but it's quite natural I'm + + + align:start position:0% +seem tricky but it's quite natural I'm +going to replace this minus by a plus + + align:start position:0% +going to replace this minus by a plus + + + align:start position:0% +going to replace this minus by a plus +and then integrate from 0 to 2 pi right + + align:start position:0% +and then integrate from 0 to 2 pi right + + + align:start position:0% +and then integrate from 0 to 2 pi right +because I was going to be integrating + + align:start position:0% +because I was going to be integrating + + + align:start position:0% +because I was going to be integrating +from 2 pi to zero and so I just flipped + + align:start position:0% +from 2 pi to zero and so I just flipped + + + align:start position:0% +from 2 pi to zero and so I just flipped +the order and made that sign of plus + + align:start position:0% +the order and made that sign of plus + + + align:start position:0% +the order and made that sign of plus +okay so that should be fine and then y I + + align:start position:0% +okay so that should be fine and then y I + + + align:start position:0% +okay so that should be fine and then y I +already know what it is it's a * 1 - + + align:start position:0% +already know what it is it's a * 1 - + + + align:start position:0% +already know what it is it's a * 1 - +cosine + + align:start position:0% +cosine + + + align:start position:0% +cosine +Theta and now I just have to figure out + + align:start position:0% +Theta and now I just have to figure out + + + align:start position:0% +Theta and now I just have to figure out +what is DX + + align:start position:0% +what is DX + + + align:start position:0% +what is DX +okay so we have to come back over for + + align:start position:0% +okay so we have to come back over for + + + align:start position:0% +okay so we have to come back over for +one second we're going to come over here + + align:start position:0% +one second we're going to come over here + + + align:start position:0% +one second we're going to come over here +and we're going to look at + + align:start position:0% +and we're going to look at + + + align:start position:0% +and we're going to look at +DX if x is equal to a * thetus sin Theta + + align:start position:0% +DX if x is equal to a * thetus sin Theta + + + align:start position:0% +DX if x is equal to a * thetus sin Theta +then DX is just a * 1 - cosine Theta so + + align:start position:0% +then DX is just a * 1 - cosine Theta so + + + align:start position:0% +then DX is just a * 1 - cosine Theta so +that's nice because that's actually what + + align:start position:0% +that's nice because that's actually what + + + align:start position:0% +that's nice because that's actually what +we already have so if you come back over + + align:start position:0% +we already have so if you come back over + + + align:start position:0% +we already have so if you come back over +here oh I should say also with the D + + align:start position:0% +here oh I should say also with the D + + + align:start position:0% +here oh I should say also with the D +Theta right if you come back over here + + align:start position:0% +Theta right if you come back over here + + + align:start position:0% +Theta right if you come back over here +DX gives you a squar a it gives you a + + align:start position:0% +DX gives you a squar a it gives you a + + + align:start position:0% +DX gives you a squar a it gives you a +square this and it gives you a d + + align:start position:0% +square this and it gives you a d + + + align:start position:0% +square this and it gives you a d +Theta so that actually gives you + + align:start position:0% +Theta so that actually gives you + + + align:start position:0% +Theta so that actually gives you +everything you need now I am not going + + align:start position:0% +everything you need now I am not going + + + align:start position:0% +everything you need now I am not going +to actually write out all the steps in + + align:start position:0% +to actually write out all the steps in + + + align:start position:0% +to actually write out all the steps in +order to do this but the way you could + + align:start position:0% +order to do this but the way you could + + + align:start position:0% +order to do this but the way you could +easily do this you can pull out the A + + align:start position:0% +easily do this you can pull out the A + + + align:start position:0% +easily do this you can pull out the A +squ and you're left with a 1us cosine + + align:start position:0% +squ and you're left with a 1us cosine + + + align:start position:0% +squ and you're left with a 1us cosine +Theta squar you might think about + + align:start position:0% +Theta squar you might think about + + + align:start position:0% +Theta squar you might think about +squaring all the terms and then you have + + align:start position:0% +squaring all the terms and then you have + + + align:start position:0% +squaring all the terms and then you have +one cosine squ Theta to deal with but + + align:start position:0% +one cosine squ Theta to deal with but + + + align:start position:0% +one cosine squ Theta to deal with but +ultimately when you get your answer I'm + + align:start position:0% +ultimately when you get your answer I'm + + + align:start position:0% +ultimately when you get your answer I'm +just going to write down what it is you + + align:start position:0% +just going to write down what it is you + + + align:start position:0% +just going to write down what it is you +get 3 Pi a 2 and you'll see you get a + + align:start position:0% +get 3 Pi a 2 and you'll see you get a + + + align:start position:0% +get 3 Pi a 2 and you'll see you get a +little bit of cancellation and it's not + + align:start position:0% +little bit of cancellation and it's not + + + align:start position:0% +little bit of cancellation and it's not +too hard to solve at this point since + + align:start position:0% +too hard to solve at this point since + + + align:start position:0% +too hard to solve at this point since +it's single variable going to assume I + + align:start position:0% +it's single variable going to assume I + + + align:start position:0% +it's single variable going to assume I +don't need to do it but you can check + + align:start position:0% +don't need to do it but you can check + + + align:start position:0% +don't need to do it but you can check +your final answer you should get I think + + align:start position:0% +your final answer you should get I think + + + align:start position:0% +your final answer you should get I think +yes I got 3 Pi a^ 2 so what we did was + + align:start position:0% +yes I got 3 Pi a^ 2 so what we did was + + + align:start position:0% +yes I got 3 Pi a^ 2 so what we did was +we took a problem again where we had a + + align:start position:0% +we took a problem again where we had a + + + align:start position:0% +we took a problem again where we had a +curve defined in terms of defined in + + align:start position:0% +curve defined in terms of defined in + + + align:start position:0% +curve defined in terms of defined in +terms of theta right we had a curve in X + + align:start position:0% +terms of theta right we had a curve in X + + + align:start position:0% +terms of theta right we had a curve in X +and Y was parameterized in Theta and we + + align:start position:0% +and Y was parameterized in Theta and we + + + align:start position:0% +and Y was parameterized in Theta and we +wanted to find an area between that + + align:start position:0% +wanted to find an area between that + + + align:start position:0% +wanted to find an area between that +curve and the x- axis and the reason we + + align:start position:0% +curve and the x- axis and the reason we + + + align:start position:0% +curve and the x- axis and the reason we +could use green theorem so easily is + + align:start position:0% +could use green theorem so easily is + + + align:start position:0% +could use green theorem so easily is +because area of a reg region of this + + align:start position:0% +because area of a reg region of this + + + align:start position:0% +because area of a reg region of this +connected region here is equal to the + + align:start position:0% +connected region here is equal to the + + + align:start position:0% +connected region here is equal to the +integral over the closed loop + + align:start position:0% +integral over the closed loop + + + align:start position:0% +integral over the closed loop +surrounding it of minus y DX or + + align:start position:0% +surrounding it of minus y DX or + + + align:start position:0% +surrounding it of minus y DX or +alternatively you could have done xdy + + align:start position:0% +alternatively you could have done xdy + + + align:start position:0% +alternatively you could have done xdy +and because I got to choose I picked the + + align:start position:0% +and because I got to choose I picked the + + + align:start position:0% +and because I got to choose I picked the +easier one and I picked the easier one + + align:start position:0% +easier one and I picked the easier one + + + align:start position:0% +easier one and I picked the easier one +in this case because Y is equal to zero + + align:start position:0% +in this case because Y is equal to zero + + + align:start position:0% +in this case because Y is equal to zero +on Parts on one part of the curve so I + + align:start position:0% +on Parts on one part of the curve so I + + + align:start position:0% +on Parts on one part of the curve so I +just ignored the C1 because that's where + + align:start position:0% +just ignored the C1 because that's where + + + align:start position:0% +just ignored the C1 because that's where +Y is zero and I looked along C2 and + + align:start position:0% +Y is zero and I looked along C2 and + + + align:start position:0% +Y is zero and I looked along C2 and +notice C2 is parameterized in this + + align:start position:0% +notice C2 is parameterized in this + + + align:start position:0% +notice C2 is parameterized in this +direction from Theta equal 2 pi to Theta + + align:start position:0% +direction from Theta equal 2 pi to Theta + + + align:start position:0% +direction from Theta equal 2 pi to Theta +equal 0 + + align:start position:0% +equal 0 + + + align:start position:0% +equal 0 +so that's why I dropped the minus sign + + align:start position:0% +so that's why I dropped the minus sign + + + align:start position:0% +so that's why I dropped the minus sign +and changed it from 0 to 2 pi that's + + align:start position:0% +and changed it from 0 to 2 pi that's + + + align:start position:0% +and changed it from 0 to 2 pi that's +where that came from and then you end up + + align:start position:0% +where that came from and then you end up + + + align:start position:0% +where that came from and then you end up +having to just determine what Y is and + + align:start position:0% +having to just determine what Y is and + + + align:start position:0% +having to just determine what Y is and +what DX are in terms of theta which we + + align:start position:0% +what DX are in terms of theta which we + + + align:start position:0% +what DX are in terms of theta which we +have we had them already in terms of + + align:start position:0% +have we had them already in terms of + + + align:start position:0% +have we had them already in terms of +theta so we could just explicitly + + align:start position:0% +theta so we could just explicitly + + + align:start position:0% +theta so we could just explicitly +determine everything do all the + + align:start position:0% +determine everything do all the + + + align:start position:0% +determine everything do all the +substitution and then evaluate the + + align:start position:0% +substitution and then evaluate the + + + align:start position:0% +substitution and then evaluate the +integral and so then that's that's all + + align:start position:0% +integral and so then that's that's all + + + align:start position:0% +integral and so then that's that's all +there is to this problem so hopefully + + align:start position:0% +there is to this problem so hopefully + + + align:start position:0% +there is to this problem so hopefully +that taught you a little more about + + align:start position:0% +that taught you a little more about + + + align:start position:0% +that taught you a little more about +greens theorem and and actually now + + align:start position:0% +greens theorem and and actually now + + + align:start position:0% +greens theorem and and actually now +you've done problems going from the left + + align:start position:0% +you've done problems going from the left + + + align:start position:0% +you've done problems going from the left +to the right and from the right to the + + align:start position:0% +to the right and from the right to the + + + align:start position:0% +to the right and from the right to the +left so you've done a little of both so + + align:start position:0% +left so you've done a little of both so + + + align:start position:0% +left so you've done a little of both so +hopefully this revealed a little bit + + align:start position:0% +hopefully this revealed a little bit + + + align:start position:0% +hopefully this revealed a little bit +more to you than you knew before that's + + align:start position:0% +more to you than you knew before that's + + + align:start position:0% +more to you than you knew before that's +where I'll stop \ No newline at end of file diff --git a/Kj6iEzXsFkI.txt b/Kj6iEzXsFkI.txt new file mode 100644 index 0000000000000000000000000000000000000000..996dfba022927779fadb015796f4050d7edd5109 --- /dev/null +++ b/Kj6iEzXsFkI.txt @@ -0,0 +1,1179 @@ +align:start position:0% + +by now we have introduced all sorts of + + align:start position:0% +by now we have introduced all sorts of + + + align:start position:0% +by now we have introduced all sorts of +pmfs for the discrete case the joint pmf + + align:start position:0% +pmfs for the discrete case the joint pmf + + + align:start position:0% +pmfs for the discrete case the joint pmf +the conditional pmf given an event and + + align:start position:0% +the conditional pmf given an event and + + + align:start position:0% +the conditional pmf given an event and +the conditional pmf of one random + + align:start position:0% +the conditional pmf of one random + + + align:start position:0% +the conditional pmf of one random +variable given another and we're moving + + align:start position:0% +variable given another and we're moving + + + align:start position:0% +variable given another and we're moving +along with a program of defining + + align:start position:0% +along with a program of defining + + + align:start position:0% +along with a program of defining +analogous concepts for the continuous + + align:start position:0% +analogous concepts for the continuous + + + align:start position:0% +analogous concepts for the continuous +case we have already discussed the joint + + align:start position:0% +case we have already discussed the joint + + + align:start position:0% +case we have already discussed the joint +PDF and the conditional PDF given an + + align:start position:0% +PDF and the conditional PDF given an + + + align:start position:0% +PDF and the conditional PDF given an +event the next item in our menu is to + + align:start position:0% +event the next item in our menu is to + + + align:start position:0% +event the next item in our menu is to +define a conditional PDF of one random + + align:start position:0% +define a conditional PDF of one random + + + align:start position:0% +define a conditional PDF of one random +variable given another random variable + + align:start position:0% +variable given another random variable + + + align:start position:0% +variable given another random variable +we proceed by first looking at the + + align:start position:0% +we proceed by first looking at the + + + align:start position:0% +we proceed by first looking at the +definition for the discrete case a + + align:start position:0% +definition for the discrete case a + + + align:start position:0% +definition for the discrete case a +typical entry of the conditional PMF is + + align:start position:0% +typical entry of the conditional PMF is + + + align:start position:0% +typical entry of the conditional PMF is +just a conditional probability but in + + align:start position:0% +just a conditional probability but in + + + align:start position:0% +just a conditional probability but in +different notation and using the + + align:start position:0% +different notation and using the + + + align:start position:0% +different notation and using the +definition of conditional probabilities + + align:start position:0% +definition of conditional probabilities + + + align:start position:0% +definition of conditional probabilities +this is equal to the ratio of the joint + + align:start position:0% +this is equal to the ratio of the joint + + + align:start position:0% +this is equal to the ratio of the joint +divided by the probability of the + + align:start position:0% +divided by the probability of the + + + align:start position:0% +divided by the probability of the +conditioning event unfortunately in the + + align:start position:0% +conditioning event unfortunately in the + + + align:start position:0% +conditioning event unfortunately in the +continuous case a definition of this + + align:start position:0% +continuous case a definition of this + + + align:start position:0% +continuous case a definition of this +form would be problematic because the + + align:start position:0% +form would be problematic because the + + + align:start position:0% +form would be problematic because the +event that Y takes on a specific value + + align:start position:0% +event that Y takes on a specific value + + + align:start position:0% +event that Y takes on a specific value +is an event that has zero probability + + align:start position:0% +is an event that has zero probability + + + align:start position:0% +is an event that has zero probability +and we know that we cannot condition on + + align:start position:0% +and we know that we cannot condition on + + + align:start position:0% +and we know that we cannot condition on +a zero probability event however we can + + align:start position:0% +a zero probability event however we can + + + align:start position:0% +a zero probability event however we can +take this expression as a guide on how + + align:start position:0% +take this expression as a guide on how + + + align:start position:0% +take this expression as a guide on how +to define a conditional PDF in the + + align:start position:0% +to define a conditional PDF in the + + + align:start position:0% +to define a conditional PDF in the +continuous case and this is the + + align:start position:0% +continuous case and this is the + + + align:start position:0% +continuous case and this is the +definition which just mimics the formula + + align:start position:0% +definition which just mimics the formula + + + align:start position:0% +definition which just mimics the formula +that we have up here notice that this + + align:start position:0% +that we have up here notice that this + + + align:start position:0% +that we have up here notice that this +conditional PDF defined this way is + + align:start position:0% +conditional PDF defined this way is + + + align:start position:0% +conditional PDF defined this way is +well-defined as long as the denominator + + align:start position:0% +well-defined as long as the denominator + + + align:start position:0% +well-defined as long as the denominator +is a positive quantity let us now try to + + align:start position:0% +is a positive quantity let us now try to + + + align:start position:0% +is a positive quantity let us now try to +make sense of this definition let us + + align:start position:0% +make sense of this definition let us + + + align:start position:0% +make sense of this definition let us +first recall the interpretation of the + + align:start position:0% +first recall the interpretation of the + + + align:start position:0% +first recall the interpretation of the +conditional PDF given an event a that + + align:start position:0% +conditional PDF given an event a that + + + align:start position:0% +conditional PDF given an event a that +has positive probability we know that + + align:start position:0% +has positive probability we know that + + + align:start position:0% +has positive probability we know that +the PDF is used to determine the + + align:start position:0% +the PDF is used to determine the + + + align:start position:0% +the PDF is used to determine the +probability of a small interval and + + align:start position:0% +probability of a small interval and + + + align:start position:0% +probability of a small interval and +similarly the conditional PDF is used to + + align:start position:0% +similarly the conditional PDF is used to + + + align:start position:0% +similarly the conditional PDF is used to +calculate the conditional probability of + + align:start position:0% +calculate the conditional probability of + + + align:start position:0% +calculate the conditional probability of +a small interval given the conditioning + + align:start position:0% +a small interval given the conditioning + + + align:start position:0% +a small interval given the conditioning +event we would like to do something + + align:start position:0% +event we would like to do something + + + align:start position:0% +event we would like to do something +similar for the conditional PDF where we + + align:start position:0% +similar for the conditional PDF where we + + + align:start position:0% +similar for the conditional PDF where we +would like to take the event a to be + + align:start position:0% +would like to take the event a to be + + + align:start position:0% +would like to take the event a to be +something like the event that Y is equal + + align:start position:0% +something like the event that Y is equal + + + align:start position:0% +something like the event that Y is equal +to some particular value little + + align:start position:0% +to some particular value little + + + align:start position:0% +to some particular value little +why but as we said this is problematic + + align:start position:0% +why but as we said this is problematic + + + align:start position:0% +why but as we said this is problematic +because this event does not have + + align:start position:0% +because this event does not have + + + align:start position:0% +because this event does not have +positive probability so instead we can + + align:start position:0% +positive probability so instead we can + + + align:start position:0% +positive probability so instead we can +take a to be the event that y is + + align:start position:0% +take a to be the event that y is + + + align:start position:0% +take a to be the event that y is +approximately equal to a certain value + + align:start position:0% +approximately equal to a certain value + + + align:start position:0% +approximately equal to a certain value +so we're dealing with a little interval + + align:start position:0% +so we're dealing with a little interval + + + align:start position:0% +so we're dealing with a little interval +around this value little Y which in + + align:start position:0% +around this value little Y which in + + + align:start position:0% +around this value little Y which in +general would be an event of positive + + align:start position:0% +general would be an event of positive + + + align:start position:0% +general would be an event of positive +probability and we can try to have a + + align:start position:0% +probability and we can try to have a + + + align:start position:0% +probability and we can try to have a +similar interpretation let us see how + + align:start position:0% +similar interpretation let us see how + + + align:start position:0% +similar interpretation let us see how +this works out so what does it mean that + + align:start position:0% +this works out so what does it mean that + + + align:start position:0% +this works out so what does it mean that +Y is approximately equal to some + + align:start position:0% +Y is approximately equal to some + + + align:start position:0% +Y is approximately equal to some +particular value little Y we interpret + + align:start position:0% +particular value little Y we interpret + + + align:start position:0% +particular value little Y we interpret +that as follows we're told that the + + align:start position:0% +that as follows we're told that the + + + align:start position:0% +that as follows we're told that the +random variable Y takes a value that is + + align:start position:0% +random variable Y takes a value that is + + + align:start position:0% +random variable Y takes a value that is +within epsilon where epsilon is a small + + align:start position:0% +within epsilon where epsilon is a small + + + align:start position:0% +within epsilon where epsilon is a small +number of a given value little Y and + + align:start position:0% +number of a given value little Y and + + + align:start position:0% +number of a given value little Y and +given this conditioning information we + + align:start position:0% +given this conditioning information we + + + align:start position:0% +given this conditioning information we +want to calculate the probability of a + + align:start position:0% +want to calculate the probability of a + + + align:start position:0% +want to calculate the probability of a +small interval how do we do that + + align:start position:0% +small interval how do we do that + + + align:start position:0% +small interval how do we do that +well here because this in general will + + align:start position:0% +well here because this in general will + + + align:start position:0% +well here because this in general will +be a positive probability event we can + + align:start position:0% +be a positive probability event we can + + + align:start position:0% +be a positive probability event we can +use the definition of conditional + + align:start position:0% +use the definition of conditional + + + align:start position:0% +use the definition of conditional +probabilities and it would be equal to + + align:start position:0% +probabilities and it would be equal to + + + align:start position:0% +probabilities and it would be equal to +the probability of both events happening + + align:start position:0% +the probability of both events happening + + + align:start position:0% +the probability of both events happening +divided by the probability of the + + align:start position:0% +divided by the probability of the + + + align:start position:0% +divided by the probability of the +conditioning event what is the + + align:start position:0% +conditioning event what is the + + + align:start position:0% +conditioning event what is the +probability of both events happening + + align:start position:0% +probability of both events happening + + + align:start position:0% +probability of both events happening +this is a probability of a small + + align:start position:0% +this is a probability of a small + + + align:start position:0% +this is a probability of a small +rectangle in X Y space at that rectangle + + align:start position:0% +rectangle in X Y space at that rectangle + + + align:start position:0% +rectangle in X Y space at that rectangle +the joint PDF has a certain value and + + align:start position:0% +the joint PDF has a certain value and + + + align:start position:0% +the joint PDF has a certain value and +because we're integrating over that + + align:start position:0% +because we're integrating over that + + + align:start position:0% +because we're integrating over that +rectangle and that rectangle has + + align:start position:0% +rectangle and that rectangle has + + + align:start position:0% +rectangle and that rectangle has +dimensions Delta and epsilon that + + align:start position:0% +dimensions Delta and epsilon that + + + align:start position:0% +dimensions Delta and epsilon that +probability of that small rectangle is + + align:start position:0% +probability of that small rectangle is + + + align:start position:0% +probability of that small rectangle is +approximately equal to this then we need + + align:start position:0% +approximately equal to this then we need + + + align:start position:0% +approximately equal to this then we need +the denominator which is the probability + + align:start position:0% +the denominator which is the probability + + + align:start position:0% +the denominator which is the probability +of the conditional event and this is + + align:start position:0% +of the conditional event and this is + + + align:start position:0% +of the conditional event and this is +approximately equal to the density of Y + + align:start position:0% +approximately equal to the density of Y + + + align:start position:0% +approximately equal to the density of Y +evaluated at that point times the length + + align:start position:0% +evaluated at that point times the length + + + align:start position:0% +evaluated at that point times the length +of the small interval we cancel the + + align:start position:0% +of the small interval we cancel the + + + align:start position:0% +of the small interval we cancel the +absolutes + + align:start position:0% +absolutes + + + align:start position:0% +absolutes +and then we notice that the ratio we + + align:start position:0% +and then we notice that the ratio we + + + align:start position:0% +and then we notice that the ratio we +have here is what we defined as the + + align:start position:0% +have here is what we defined as the + + + align:start position:0% +have here is what we defined as the +conditional PDF so we get this relation + + align:start position:0% +conditional PDF so we get this relation + + + align:start position:0% +conditional PDF so we get this relation +times Delta so what do we see we see + + align:start position:0% +times Delta so what do we see we see + + + align:start position:0% +times Delta so what do we see we see +the probability of a small interval is + + align:start position:0% +the probability of a small interval is + + + align:start position:0% +the probability of a small interval is +equal to a PDF times the length of the + + align:start position:0% +equal to a PDF times the length of the + + + align:start position:0% +equal to a PDF times the length of the +small interval however because we are + + align:start position:0% +small interval however because we are + + + align:start position:0% +small interval however because we are +conditioning on Y being approximately + + align:start position:0% +conditioning on Y being approximately + + + align:start position:0% +conditioning on Y being approximately +equal to a certain value we end up using + + align:start position:0% +equal to a certain value we end up using + + + align:start position:0% +equal to a certain value we end up using +a corresponding conditional PDF where + + align:start position:0% +a corresponding conditional PDF where + + + align:start position:0% +a corresponding conditional PDF where +the conditional PDF is defined this way + + align:start position:0% +the conditional PDF is defined this way + + + align:start position:0% +the conditional PDF is defined this way +so we now have an interpretation of the + + align:start position:0% +so we now have an interpretation of the + + + align:start position:0% +so we now have an interpretation of the +conditional PDF in terms of + + align:start position:0% +conditional PDF in terms of + + + align:start position:0% +conditional PDF in terms of +probabilities of small intervals now + + align:start position:0% +probabilities of small intervals now + + + align:start position:0% +probabilities of small intervals now +that we have an intuitive interpretation + + align:start position:0% +that we have an intuitive interpretation + + + align:start position:0% +that we have an intuitive interpretation +of the conditional PDF we can also use + + align:start position:0% +of the conditional PDF we can also use + + + align:start position:0% +of the conditional PDF we can also use +it to calculate conditional + + align:start position:0% +it to calculate conditional + + + align:start position:0% +it to calculate conditional +probabilities of more general events not + + align:start position:0% +probabilities of more general events not + + + align:start position:0% +probabilities of more general events not +just intervals and we do this as follows + + align:start position:0% +just intervals and we do this as follows + + + align:start position:0% +just intervals and we do this as follows +in general for continuous random + + align:start position:0% +in general for continuous random + + + align:start position:0% +in general for continuous random +variables we can find the probability + + align:start position:0% +variables we can find the probability + + + align:start position:0% +variables we can find the probability +that X belongs to a certain set by + + align:start position:0% +that X belongs to a certain set by + + + align:start position:0% +that X belongs to a certain set by +integrating a PDF over that set because + + align:start position:0% +integrating a PDF over that set because + + + align:start position:0% +integrating a PDF over that set because +here we're dealing with a conditional + + align:start position:0% +here we're dealing with a conditional + + + align:start position:0% +here we're dealing with a conditional +situation where were given the value of + + align:start position:0% +situation where were given the value of + + + align:start position:0% +situation where were given the value of +y we use the conditional PDF instead of + + align:start position:0% +y we use the conditional PDF instead of + + + align:start position:0% +y we use the conditional PDF instead of +the true PDF and with this way we + + align:start position:0% +the true PDF and with this way we + + + align:start position:0% +the true PDF and with this way we +calculate the conditional probability + + align:start position:0% +calculate the conditional probability + + + align:start position:0% +calculate the conditional probability +now the difficulty is that this + + align:start position:0% +now the difficulty is that this + + + align:start position:0% +now the difficulty is that this +conditional probability is not a + + align:start position:0% +conditional probability is not a + + + align:start position:0% +conditional probability is not a +well-defined quantity according to what + + align:start position:0% +well-defined quantity according to what + + + align:start position:0% +well-defined quantity according to what +we did early on in this class we cannot + + align:start position:0% +we did early on in this class we cannot + + + align:start position:0% +we did early on in this class we cannot +condition on 0 probability events but we + + align:start position:0% +condition on 0 probability events but we + + + align:start position:0% +condition on 0 probability events but we +can get around this difficulty as + + align:start position:0% +can get around this difficulty as + + + align:start position:0% +can get around this difficulty as +follows this quantity is well-defined + + align:start position:0% +follows this quantity is well-defined + + + align:start position:0% +follows this quantity is well-defined +and we can use this quantity as the + + align:start position:0% +and we can use this quantity as the + + + align:start position:0% +and we can use this quantity as the +definition of this conditional + + align:start position:0% +definition of this conditional + + + align:start position:0% +definition of this conditional +probability and so we have managed to + + align:start position:0% +probability and so we have managed to + + + align:start position:0% +probability and so we have managed to +provide the definition of conditional + + align:start position:0% +provide the definition of conditional + + + align:start position:0% +provide the definition of conditional +probabilities given a 0 probability + + align:start position:0% +probabilities given a 0 probability + + + align:start position:0% +probabilities given a 0 probability +event of a certain type it turns out + + align:start position:0% +event of a certain type it turns out + + + align:start position:0% +event of a certain type it turns out +that this definition is sound and + + align:start position:0% +that this definition is sound and + + + align:start position:0% +that this definition is sound and +consistent with everything else that we + + align:start position:0% +consistent with everything else that we + + + align:start position:0% +consistent with everything else that we +are doing but when we are dealing with + + align:start position:0% +are doing but when we are dealing with + + + align:start position:0% +are doing but when we are dealing with +particular problems and applications we + + align:start position:0% +particular problems and applications we + + + align:start position:0% +particular problems and applications we +can generally forget about all these + + align:start position:0% +can generally forget about all these + + + align:start position:0% +can generally forget about all these +subtleties that we have been discussing + + align:start position:0% +subtleties that we have been discussing + + + align:start position:0% +subtleties that we have been discussing +here the bottom line is that we will be + + align:start position:0% +here the bottom line is that we will be + + + align:start position:0% +here the bottom line is that we will be +treating conditional PDFs given the + + align:start position:0% +treating conditional PDFs given the + + + align:start position:0% +treating conditional PDFs given the +value of a random variable Y just as + + align:start position:0% +value of a random variable Y just as + + + align:start position:0% +value of a random variable Y just as +ordinary PDFs + + align:start position:0% +ordinary PDFs + + + align:start position:0% +ordinary PDFs +but given the information that this + + align:start position:0% +but given the information that this + + + align:start position:0% +but given the information that this +random variable took on a specific value + + align:start position:0% +random variable took on a specific value + + + align:start position:0% +random variable took on a specific value +and in that conditional universe we will + + align:start position:0% +and in that conditional universe we will + + + align:start position:0% +and in that conditional universe we will +calculate probabilities than usual way + + align:start position:0% +calculate probabilities than usual way + + + align:start position:0% +calculate probabilities than usual way +by using conditional PDFs instead of + + align:start position:0% +by using conditional PDFs instead of + + + align:start position:0% +by using conditional PDFs instead of +ordinary PDFs \ No newline at end of file diff --git a/Kycmb2IwV-Y.txt b/Kycmb2IwV-Y.txt new file mode 100644 index 0000000000000000000000000000000000000000..4a55b6a2a269115df8796291fa47499ffe8be476 --- /dev/null +++ b/Kycmb2IwV-Y.txt @@ -0,0 +1,2307 @@ +align:start position:0% + +we will now study a problem which is + + align:start position:0% +we will now study a problem which is + + + align:start position:0% +we will now study a problem which is +quite difficult to approach in a direct + + align:start position:0% +quite difficult to approach in a direct + + + align:start position:0% +quite difficult to approach in a direct +brute-force manner but becomes tractable + + align:start position:0% +brute-force manner but becomes tractable + + + align:start position:0% +brute-force manner but becomes tractable +once we break it down into simpler + + align:start position:0% +once we break it down into simpler + + + align:start position:0% +once we break it down into simpler +pieces using several of the tricks that + + align:start position:0% +pieces using several of the tricks that + + + align:start position:0% +pieces using several of the tricks that +we have learned so far and this problem + + align:start position:0% +we have learned so far and this problem + + + align:start position:0% +we have learned so far and this problem +will also be a good opportunity for + + align:start position:0% +will also be a good opportunity for + + + align:start position:0% +will also be a good opportunity for +reviewing some of the tricks and + + align:start position:0% +reviewing some of the tricks and + + + align:start position:0% +reviewing some of the tricks and +techniques that we have developed the + + align:start position:0% +techniques that we have developed the + + + align:start position:0% +techniques that we have developed the +problem is the following there are n + + align:start position:0% +problem is the following there are n + + + align:start position:0% +problem is the following there are n +people and let's say for the purpose of + + align:start position:0% +people and let's say for the purpose of + + + align:start position:0% +people and let's say for the purpose of +illustration that we have three people + + align:start position:0% +illustration that we have three people + + + align:start position:0% +illustration that we have three people +persons 1 2 & 3 and each person has a + + align:start position:0% +persons 1 2 & 3 and each person has a + + + align:start position:0% +persons 1 2 & 3 and each person has a +hat they throw their hats inside a box + + align:start position:0% +hat they throw their hats inside a box + + + align:start position:0% +hat they throw their hats inside a box +and then each person picks a hat at + + align:start position:0% +and then each person picks a hat at + + + align:start position:0% +and then each person picks a hat at +random out of that box + + align:start position:0% +random out of that box + + + align:start position:0% +random out of that box +so here are the three hats and one + + align:start position:0% +so here are the three hats and one + + + align:start position:0% +so here are the three hats and one +possible outcome of this experiment is + + align:start position:0% +possible outcome of this experiment is + + + align:start position:0% +possible outcome of this experiment is +that person 1 ends up with hat number + + align:start position:0% +that person 1 ends up with hat number + + + align:start position:0% +that person 1 ends up with hat number +two person two ends up with hat number 1 + + align:start position:0% +two person two ends up with hat number 1 + + + align:start position:0% +two person two ends up with hat number 1 +and person 3 ends up we had number three + + align:start position:0% +and person 3 ends up we had number three + + + align:start position:0% +and person 3 ends up we had number three +we could indicate the hats that each + + align:start position:0% +we could indicate the hats that each + + + align:start position:0% +we could indicate the hats that each +person got by noting the here the + + align:start position:0% +person got by noting the here the + + + align:start position:0% +person got by noting the here the +numbers associated with each person the + + align:start position:0% +numbers associated with each person the + + + align:start position:0% +numbers associated with each person the +hat numbers and notice that this + + align:start position:0% +hat numbers and notice that this + + + align:start position:0% +hat numbers and notice that this +sequence of numbers which is a + + align:start position:0% +sequence of numbers which is a + + + align:start position:0% +sequence of numbers which is a +description of the outcome of the + + align:start position:0% +description of the outcome of the + + + align:start position:0% +description of the outcome of the +experiment is just a permutation of the + + align:start position:0% +experiment is just a permutation of the + + + align:start position:0% +experiment is just a permutation of the +numbers 1 2 3 of the hats + + align:start position:0% +numbers 1 2 3 of the hats + + + align:start position:0% +numbers 1 2 3 of the hats +so we permute the hat numbers so that we + + align:start position:0% +so we permute the hat numbers so that we + + + align:start position:0% +so we permute the hat numbers so that we +can place them next to the person that + + align:start position:0% +can place them next to the person that + + + align:start position:0% +can place them next to the person that +got each one of the hats in particular + + align:start position:0% +got each one of the hats in particular + + + align:start position:0% +got each one of the hats in particular +we have n factorial possible outcomes + + align:start position:0% +we have n factorial possible outcomes + + + align:start position:0% +we have n factorial possible outcomes +this is the number of possible + + align:start position:0% +this is the number of possible + + + align:start position:0% +this is the number of possible +permutations what does it mean to pick + + align:start position:0% +permutations what does it mean to pick + + + align:start position:0% +permutations what does it mean to pick +hats at random one interpretation is + + align:start position:0% +hats at random one interpretation is + + + align:start position:0% +hats at random one interpretation is +that every permutation is equally likely + + align:start position:0% +that every permutation is equally likely + + + align:start position:0% +that every permutation is equally likely +and since we have n factorial + + align:start position:0% +and since we have n factorial + + + align:start position:0% +and since we have n factorial +permutations each permutation will have + + align:start position:0% +permutations each permutation will have + + + align:start position:0% +permutations each permutation will have +a probability of 1 over N factorial but + + align:start position:0% +a probability of 1 over N factorial but + + + align:start position:0% +a probability of 1 over N factorial but +there is another way of describing + + align:start position:0% +there is another way of describing + + + align:start position:0% +there is another way of describing +model which is the following person one + + align:start position:0% +model which is the following person one + + + align:start position:0% +model which is the following person one +gets a hat at random out of the three + + align:start position:0% +gets a hat at random out of the three + + + align:start position:0% +gets a hat at random out of the three +available then persons two gets a hat at + + align:start position:0% +available then persons two gets a hat at + + + align:start position:0% +available then persons two gets a hat at +random out of the remaining hats then + + align:start position:0% +random out of the remaining hats then + + + align:start position:0% +random out of the remaining hats then +person three gets the remaining hat each + + align:start position:0% +person three gets the remaining hat each + + + align:start position:0% +person three gets the remaining hat each +time that there is a choice each one of + + align:start position:0% +time that there is a choice each one of + + + align:start position:0% +time that there is a choice each one of +the available hats is equally likely to + + align:start position:0% +the available hats is equally likely to + + + align:start position:0% +the available hats is equally likely to +be picked as any other hat let us + + align:start position:0% +be picked as any other hat let us + + + align:start position:0% +be picked as any other hat let us +calculate the probability let's say that + + align:start position:0% +calculate the probability let's say that + + + align:start position:0% +calculate the probability let's say that +this particular permutation gets + + align:start position:0% +this particular permutation gets + + + align:start position:0% +this particular permutation gets +materialized the probability that person + + align:start position:0% +materialized the probability that person + + + align:start position:0% +materialized the probability that person +one yet hat number two is one-third then + + align:start position:0% +one yet hat number two is one-third then + + + align:start position:0% +one yet hat number two is one-third then +we're left with two hats person two has + + align:start position:0% +we're left with two hats person two has + + + align:start position:0% +we're left with two hats person two has +two hats to choose from the probability + + align:start position:0% +two hats to choose from the probability + + + align:start position:0% +two hats to choose from the probability +that it picks this particular hat is + + align:start position:0% +that it picks this particular hat is + + + align:start position:0% +that it picks this particular hat is +going to be one-half and finally person + + align:start position:0% +going to be one-half and finally person + + + align:start position:0% +going to be one-half and finally person +three has only one hat available so it + + align:start position:0% +three has only one hat available so it + + + align:start position:0% +three has only one hat available so it +will be picked with probability one so + + align:start position:0% +will be picked with probability one so + + + align:start position:0% +will be picked with probability one so +the probability of this particular + + align:start position:0% +the probability of this particular + + + align:start position:0% +the probability of this particular +permutation is one over three factorial + + align:start position:0% +permutation is one over three factorial + + + align:start position:0% +permutation is one over three factorial +but you can repeat this argument and + + align:start position:0% +but you can repeat this argument and + + + align:start position:0% +but you can repeat this argument and +consider any other permutation and you + + align:start position:0% +consider any other permutation and you + + + align:start position:0% +consider any other permutation and you +will always be getting the same answer + + align:start position:0% +will always be getting the same answer + + + align:start position:0% +will always be getting the same answer +any particular permutation has the same + + align:start position:0% +any particular permutation has the same + + + align:start position:0% +any particular permutation has the same +probability one over three factorial the + + align:start position:0% +probability one over three factorial the + + + align:start position:0% +probability one over three factorial the +same argument goes through for the case + + align:start position:0% +same argument goes through for the case + + + align:start position:0% +same argument goes through for the case +of general N and people and n hats and + + align:start position:0% +of general N and people and n hats and + + + align:start position:0% +of general N and people and n hats and +we will find that any permutation will + + align:start position:0% +we will find that any permutation will + + + align:start position:0% +we will find that any permutation will +have the same probability one over N + + align:start position:0% +have the same probability one over N + + + align:start position:0% +have the same probability one over N +factorial therefore the process of + + align:start position:0% +factorial therefore the process of + + + align:start position:0% +factorial therefore the process of +picking one hat at a time is + + align:start position:0% +picking one hat at a time is + + + align:start position:0% +picking one hat at a time is +probabilistically identical to a model + + align:start position:0% +probabilistically identical to a model + + + align:start position:0% +probabilistically identical to a model +in which we simply state that all + + align:start position:0% +in which we simply state that all + + + align:start position:0% +in which we simply state that all +permutations are equally likely now that + + align:start position:0% +permutations are equally likely now that + + + align:start position:0% +permutations are equally likely now that +we have described our model and our + + align:start position:0% +we have described our model and our + + + align:start position:0% +we have described our model and our +process and the associated probabilities + + align:start position:0% +process and the associated probabilities + + + align:start position:0% +process and the associated probabilities +let us consider the question we want to + + align:start position:0% +let us consider the question we want to + + + align:start position:0% +let us consider the question we want to +answer let X be the number of people who + + align:start position:0% +answer let X be the number of people who + + + align:start position:0% +answer let X be the number of people who +get their own hat back for example for + + align:start position:0% +get their own hat back for example for + + + align:start position:0% +get their own hat back for example for +the outcome that we have drawn here the + + align:start position:0% +the outcome that we have drawn here the + + + align:start position:0% +the outcome that we have drawn here the +only person who gets their own hat back + + align:start position:0% +only person who gets their own hat back + + + align:start position:0% +only person who gets their own hat back +is person 3 and so in this case X + + align:start position:0% +is person 3 and so in this case X + + + align:start position:0% +is person 3 and so in this case X +happens to take the value of 1 + + align:start position:0% +happens to take the value of 1 + + + align:start position:0% +happens to take the value of 1 +what we want to do is to calculate the + + align:start position:0% +what we want to do is to calculate the + + + align:start position:0% +what we want to do is to calculate the +expected value of the random variable X + + align:start position:0% +expected value of the random variable X + + + align:start position:0% +expected value of the random variable X +the problem is difficult because if you + + align:start position:0% +the problem is difficult because if you + + + align:start position:0% +the problem is difficult because if you +try to calculate the PMF of the random + + align:start position:0% +try to calculate the PMF of the random + + + align:start position:0% +try to calculate the PMF of the random +variable X and then use the definition + + align:start position:0% +variable X and then use the definition + + + align:start position:0% +variable X and then use the definition +of the expectation to calculate this sum + + align:start position:0% +of the expectation to calculate this sum + + + align:start position:0% +of the expectation to calculate this sum +you will run into big difficulties + + align:start position:0% +you will run into big difficulties + + + align:start position:0% +you will run into big difficulties +calculating this quantity the PMF of X + + align:start position:0% +calculating this quantity the PMF of X + + + align:start position:0% +calculating this quantity the PMF of X +is difficult and it is difficult because + + align:start position:0% +is difficult and it is difficult because + + + align:start position:0% +is difficult and it is difficult because +there is no simple expression that + + align:start position:0% +there is no simple expression that + + + align:start position:0% +there is no simple expression that +describes it so we need to do something + + align:start position:0% +describes it so we need to do something + + + align:start position:0% +describes it so we need to do something +more intelligent find some other way of + + align:start position:0% +more intelligent find some other way of + + + align:start position:0% +more intelligent find some other way of +approaching the problem the trick that + + align:start position:0% +approaching the problem the trick that + + + align:start position:0% +approaching the problem the trick that +we will use is to employ indicator + + align:start position:0% +we will use is to employ indicator + + + align:start position:0% +we will use is to employ indicator +variables let X I be equal to 1 if + + align:start position:0% +variables let X I be equal to 1 if + + + align:start position:0% +variables let X I be equal to 1 if +person I selects their own hat and 0 + + align:start position:0% +person I selects their own hat and 0 + + + align:start position:0% +person I selects their own hat and 0 +otherwise so then each one of the excise + + align:start position:0% +otherwise so then each one of the excise + + + align:start position:0% +otherwise so then each one of the excise +is 1 whenever a person has selected + + align:start position:0% +is 1 whenever a person has selected + + + align:start position:0% +is 1 whenever a person has selected +their own hat and by adding all the ones + + align:start position:0% +their own hat and by adding all the ones + + + align:start position:0% +their own hat and by adding all the ones +that we may get we obtain the total + + align:start position:0% +that we may get we obtain the total + + + align:start position:0% +that we may get we obtain the total +number of people who have selected their + + align:start position:0% +number of people who have selected their + + + align:start position:0% +number of people who have selected their +own hats this makes things easier + + align:start position:0% +own hats this makes things easier + + + align:start position:0% +own hats this makes things easier +because now to calculate the expected + + align:start position:0% +because now to calculate the expected + + + align:start position:0% +because now to calculate the expected +value of X it's sufficient to calculate + + align:start position:0% +value of X it's sufficient to calculate + + + align:start position:0% +value of X it's sufficient to calculate +the expected value of each one of those + + align:start position:0% +the expected value of each one of those + + + align:start position:0% +the expected value of each one of those +terms and add the expected values which + + align:start position:0% +terms and add the expected values which + + + align:start position:0% +terms and add the expected values which +were allowed to do because of linearity + + align:start position:0% +were allowed to do because of linearity + + + align:start position:0% +were allowed to do because of linearity +so let us look at a typical term here + + align:start position:0% +so let us look at a typical term here + + + align:start position:0% +so let us look at a typical term here +what is the expected value of x I if you + + align:start position:0% +what is the expected value of x I if you + + + align:start position:0% +what is the expected value of x I if you +consider the first description of our + + align:start position:0% +consider the first description of our + + + align:start position:0% +consider the first description of our +model all permutations are equally + + align:start position:0% +model all permutations are equally + + + align:start position:0% +model all permutations are equally +likely this description is symmetric + + align:start position:0% +likely this description is symmetric + + + align:start position:0% +likely this description is symmetric +with respect to all the persons so the + + align:start position:0% +with respect to all the persons so the + + + align:start position:0% +with respect to all the persons so the +expected value of X I should be the same + + align:start position:0% +expected value of X I should be the same + + + align:start position:0% +expected value of X I should be the same +as the expected value of x1 now to + + align:start position:0% +as the expected value of x1 now to + + + align:start position:0% +as the expected value of x1 now to +calculate the expected value of x1 we + + align:start position:0% +calculate the expected value of x1 we + + + align:start position:0% +calculate the expected value of x1 we +will consider the sequential description + + align:start position:0% +will consider the sequential description + + + align:start position:0% +will consider the sequential description +of the process in which one is the first + + align:start position:0% +of the process in which one is the first + + + align:start position:0% +of the process in which one is the first +person to pick a hat now since x1 is a + + align:start position:0% +person to pick a hat now since x1 is a + + + align:start position:0% +person to pick a hat now since x1 is a +Bernoulli random variable that takes + + align:start position:0% +Bernoulli random variable that takes + + + align:start position:0% +Bernoulli random variable that takes +values 0 or 1 the expected value of x1 + + align:start position:0% +values 0 or 1 the expected value of x1 + + + align:start position:0% +values 0 or 1 the expected value of x1 +is just the probability that X + + align:start position:0% +is just the probability that X + + + align:start position:0% +is just the probability that X +one is equal to one and if person one is + + align:start position:0% +one is equal to one and if person one is + + + align:start position:0% +one is equal to one and if person one is +the first one to choose a hat that + + align:start position:0% +the first one to choose a hat that + + + align:start position:0% +the first one to choose a hat that +person has probability 1 over n of + + align:start position:0% +person has probability 1 over n of + + + align:start position:0% +person has probability 1 over n of +obtaining the correct hat so each one of + + align:start position:0% +obtaining the correct hat so each one of + + + align:start position:0% +obtaining the correct hat so each one of +these random variables has an expected + + align:start position:0% +these random variables has an expected + + + align:start position:0% +these random variables has an expected +value of 1 over n the expected value of + + align:start position:0% +value of 1 over n the expected value of + + + align:start position:0% +value of 1 over n the expected value of +x by linearity is going to be the sum of + + align:start position:0% +x by linearity is going to be the sum of + + + align:start position:0% +x by linearity is going to be the sum of +the expected values there is n of them + + align:start position:0% +the expected values there is n of them + + + align:start position:0% +the expected values there is n of them +each expected value is 1 over N and so + + align:start position:0% +each expected value is 1 over N and so + + + align:start position:0% +each expected value is 1 over N and so +the final answer is 1 this is the + + align:start position:0% +the final answer is 1 this is the + + + align:start position:0% +the final answer is 1 this is the +expected value of the random variable X + + align:start position:0% + + + + align:start position:0% + +let us now move and try to calculate a + + align:start position:0% +let us now move and try to calculate a + + + align:start position:0% +let us now move and try to calculate a +more difficult quantity namely the + + align:start position:0% +more difficult quantity namely the + + + align:start position:0% +more difficult quantity namely the +variance of X how shall we proceed + + align:start position:0% +variance of X how shall we proceed + + + align:start position:0% +variance of X how shall we proceed +things would be easiest if the random + + align:start position:0% +things would be easiest if the random + + + align:start position:0% +things would be easiest if the random +variables X I were independent because + + align:start position:0% +variables X I were independent because + + + align:start position:0% +variables X I were independent because +in that case the variance of X would be + + align:start position:0% +in that case the variance of X would be + + + align:start position:0% +in that case the variance of X would be +the sum of the variances of the x i's + + align:start position:0% +the sum of the variances of the x i's + + + align:start position:0% +the sum of the variances of the x i's +but are the X is independent let us + + align:start position:0% +but are the X is independent let us + + + align:start position:0% +but are the X is independent let us +consider a special case suppose that we + + align:start position:0% +consider a special case suppose that we + + + align:start position:0% +consider a special case suppose that we +only have two persons and that I told + + align:start position:0% +only have two persons and that I told + + + align:start position:0% +only have two persons and that I told +you that the first person got their own + + align:start position:0% +you that the first person got their own + + + align:start position:0% +you that the first person got their own +hat back in that case the second person + + align:start position:0% +hat back in that case the second person + + + align:start position:0% +hat back in that case the second person +must have also gotten their own hat back + + align:start position:0% +must have also gotten their own hat back + + + align:start position:0% +must have also gotten their own hat back +if on the other hand person 1 did not + + align:start position:0% +if on the other hand person 1 did not + + + align:start position:0% +if on the other hand person 1 did not +get their own hat back then person 2 + + align:start position:0% +get their own hat back then person 2 + + + align:start position:0% +get their own hat back then person 2 +will not get their own hat back either + + align:start position:0% +will not get their own hat back either + + + align:start position:0% +will not get their own hat back either +because in this scenario person one gets + + align:start position:0% +because in this scenario person one gets + + + align:start position:0% +because in this scenario person one gets +hat too and that means that person two + + align:start position:0% +hat too and that means that person two + + + align:start position:0% +hat too and that means that person two +gets hot one so we see that knowing the + + align:start position:0% +gets hot one so we see that knowing the + + + align:start position:0% +gets hot one so we see that knowing the +value of the random variable X 1 tells + + align:start position:0% +value of the random variable X 1 tells + + + align:start position:0% +value of the random variable X 1 tells +us a lot about the value of the random + + align:start position:0% +us a lot about the value of the random + + + align:start position:0% +us a lot about the value of the random +variable X 2 and that means that the + + align:start position:0% +variable X 2 and that means that the + + + align:start position:0% +variable X 2 and that means that the +random variables X 1 and X 2 are + + align:start position:0% +random variables X 1 and X 2 are + + + align:start position:0% +random variables X 1 and X 2 are +dependent more generally if I were to + + align:start position:0% +dependent more generally if I were to + + + align:start position:0% +dependent more generally if I were to +tell you that the + + align:start position:0% +tell you that the + + + align:start position:0% +tell you that the +first and -1 people got their own hats + + align:start position:0% +first and -1 people got their own hats + + + align:start position:0% +first and -1 people got their own hats +back then the last remaining person will + + align:start position:0% +back then the last remaining person will + + + align:start position:0% +back then the last remaining person will +have his or her own hat available to be + + align:start position:0% +have his or her own hat available to be + + + align:start position:0% +have his or her own hat available to be +picked that's going to be the only + + align:start position:0% +picked that's going to be the only + + + align:start position:0% +picked that's going to be the only +available hat and then person and will + + align:start position:0% +available hat and then person and will + + + align:start position:0% +available hat and then person and will +also get their hat back so we see that + + align:start position:0% +also get their hat back so we see that + + + align:start position:0% +also get their hat back so we see that +information about some of the excise + + align:start position:0% +information about some of the excise + + + align:start position:0% +information about some of the excise +gives us information about the remaining + + align:start position:0% +gives us information about the remaining + + + align:start position:0% +gives us information about the remaining +X and and again this means that the + + align:start position:0% +X and and again this means that the + + + align:start position:0% +X and and again this means that the +random variables are dependent since we + + align:start position:0% +random variables are dependent since we + + + align:start position:0% +random variables are dependent since we +do not have independence we cannot find + + align:start position:0% +do not have independence we cannot find + + + align:start position:0% +do not have independence we cannot find +the variance by just adding the + + align:start position:0% +the variance by just adding the + + + align:start position:0% +the variance by just adding the +variances of the different random + + align:start position:0% +variances of the different random + + + align:start position:0% +variances of the different random +variables but we need to do a lot more + + align:start position:0% +variables but we need to do a lot more + + + align:start position:0% +variables but we need to do a lot more +work in that direction in general + + align:start position:0% +work in that direction in general + + + align:start position:0% +work in that direction in general +whenever we need to calculate variances + + align:start position:0% +whenever we need to calculate variances + + + align:start position:0% +whenever we need to calculate variances +it is usually simpler to carry out the + + align:start position:0% +it is usually simpler to carry out the + + + align:start position:0% +it is usually simpler to carry out the +calculation using this alternative form + + align:start position:0% +calculation using this alternative form + + + align:start position:0% +calculation using this alternative form +for the variance so let us start towards + + align:start position:0% +for the variance so let us start towards + + + align:start position:0% +for the variance so let us start towards +a calculation of the expected value of x + + align:start position:0% +a calculation of the expected value of x + + + align:start position:0% +a calculation of the expected value of x +squared now the random variable x + + align:start position:0% +squared now the random variable x + + + align:start position:0% +squared now the random variable x +squared by simple algebra is this + + align:start position:0% +squared by simple algebra is this + + + align:start position:0% +squared by simple algebra is this +expression times itself and by expanding + + align:start position:0% +expression times itself and by expanding + + + align:start position:0% +expression times itself and by expanding +the product we get all sorts of cross + + align:start position:0% +the product we get all sorts of cross + + + align:start position:0% +the product we get all sorts of cross +terms some of these cross terms will be + + align:start position:0% +terms some of these cross terms will be + + + align:start position:0% +terms some of these cross terms will be +of the type X 1 times X 1 or X 2 times X + + align:start position:0% +of the type X 1 times X 1 or X 2 times X + + + align:start position:0% +of the type X 1 times X 1 or X 2 times X +2 these will be terms of this form and + + align:start position:0% +2 these will be terms of this form and + + + align:start position:0% +2 these will be terms of this form and +there is n of them and then we get cross + + align:start position:0% +there is n of them and then we get cross + + + align:start position:0% +there is n of them and then we get cross +terms such as X 1 times X 2 X 1 times X + + align:start position:0% +terms such as X 1 times X 2 X 1 times X + + + align:start position:0% +terms such as X 1 times X 2 X 1 times X +3 X 2 times X 1 and so on how many terms + + align:start position:0% +3 X 2 times X 1 and so on how many terms + + + align:start position:0% +3 X 2 times X 1 and so on how many terms +do we have here well if we have n terms + + align:start position:0% +do we have here well if we have n terms + + + align:start position:0% +do we have here well if we have n terms +multiplying another terms we have a + + align:start position:0% +multiplying another terms we have a + + + align:start position:0% +multiplying another terms we have a +total of n squared terms and are already + + align:start position:0% +total of n squared terms and are already + + + align:start position:0% +total of n squared terms and are already +here so the remaining terms which are + + align:start position:0% +here so the remaining terms which are + + + align:start position:0% +here so the remaining terms which are +the cross terms will be N squared minus + + align:start position:0% +the cross terms will be N squared minus + + + align:start position:0% +the cross terms will be N squared minus +n or in a simpler form it's n times n + + align:start position:0% +n or in a simpler form it's n times n + + + align:start position:0% +n or in a simpler form it's n times n +minus 1 so now how are we going to + + align:start position:0% +minus 1 so now how are we going to + + + align:start position:0% +minus 1 so now how are we going to +calculate the expected value of x + + align:start position:0% +calculate the expected value of x + + + align:start position:0% +calculate the expected value of x +squared well we will use linearity of + + align:start position:0% +squared well we will use linearity of + + + align:start position:0% +squared well we will use linearity of +expectations so we need to calculate the + + align:start position:0% +expectations so we need to calculate the + + + align:start position:0% +expectations so we need to calculate the +expected value of x I squared and we + + align:start position:0% +expected value of x I squared and we + + + align:start position:0% +expected value of x I squared and we +also need to calculate + + align:start position:0% +also need to calculate + + + align:start position:0% +also need to calculate +the expected value of x IX J when I is + + align:start position:0% +the expected value of x IX J when I is + + + align:start position:0% +the expected value of x IX J when I is +different from J let us start with X I + + align:start position:0% +different from J let us start with X I + + + align:start position:0% +different from J let us start with X I +squared first if we use the symmetric + + align:start position:0% +squared first if we use the symmetric + + + align:start position:0% +squared first if we use the symmetric +description of our model all + + align:start position:0% +description of our model all + + + align:start position:0% +description of our model all +permutations are equally likely then all + + align:start position:0% +permutations are equally likely then all + + + align:start position:0% +permutations are equally likely then all +persons play the same role there's + + align:start position:0% +persons play the same role there's + + + align:start position:0% +persons play the same role there's +symmetry in the problem so X I squared + + align:start position:0% +symmetry in the problem so X I squared + + + align:start position:0% +symmetry in the problem so X I squared +has the same distribution as x1 squared + + align:start position:0% + + + + align:start position:0% + +then x1 is a zero one random variable a + + align:start position:0% +then x1 is a zero one random variable a + + + align:start position:0% +then x1 is a zero one random variable a +Bernoulli random variable so x1 squared + + align:start position:0% +Bernoulli random variable so x1 squared + + + align:start position:0% +Bernoulli random variable so x1 squared +will always take the same numerical + + align:start position:0% +will always take the same numerical + + + align:start position:0% +will always take the same numerical +value as the random variable x1 this is + + align:start position:0% +value as the random variable x1 this is + + + align:start position:0% +value as the random variable x1 this is +a very special case which happens only + + align:start position:0% +a very special case which happens only + + + align:start position:0% +a very special case which happens only +because a random variable takes values + + align:start position:0% +because a random variable takes values + + + align:start position:0% +because a random variable takes values +in 0 1 & 0 squared is the same 0 1 + + align:start position:0% +in 0 1 & 0 squared is the same 0 1 + + + align:start position:0% +in 0 1 & 0 squared is the same 0 1 +squared is the same as 1 this expected + + align:start position:0% +squared is the same as 1 this expected + + + align:start position:0% +squared is the same as 1 this expected +value is something that we have already + + align:start position:0% +value is something that we have already + + + align:start position:0% +value is something that we have already +calculated and it is 1 over N let us now + + align:start position:0% +calculated and it is 1 over N let us now + + + align:start position:0% +calculated and it is 1 over N let us now +move to the calculation of the + + align:start position:0% +move to the calculation of the + + + align:start position:0% +move to the calculation of the +expectation of a typical term inside + + align:start position:0% +expectation of a typical term inside + + + align:start position:0% +expectation of a typical term inside +this song so let a be different than J + + align:start position:0% +this song so let a be different than J + + + align:start position:0% +this song so let a be different than J +and look at the expected value of X I XJ + + align:start position:0% +and look at the expected value of X I XJ + + + align:start position:0% +and look at the expected value of X I XJ +once more because of the symmetry of the + + align:start position:0% +once more because of the symmetry of the + + + align:start position:0% +once more because of the symmetry of the +probabilistic model it doesn't matter + + align:start position:0% +probabilistic model it doesn't matter + + + align:start position:0% +probabilistic model it doesn't matter +which I and J we are considering so we + + align:start position:0% +which I and J we are considering so we + + + align:start position:0% +which I and J we are considering so we +might as well consider the product of x1 + + align:start position:0% +might as well consider the product of x1 + + + align:start position:0% +might as well consider the product of x1 +with x2 now x1 and x2 take values 0 and + + align:start position:0% +with x2 now x1 and x2 take values 0 and + + + align:start position:0% +with x2 now x1 and x2 take values 0 and +1 and the product of the two also takes + + align:start position:0% +1 and the product of the two also takes + + + align:start position:0% +1 and the product of the two also takes +values 0 and 1 so this is a Bernoulli + + align:start position:0% +values 0 and 1 so this is a Bernoulli + + + align:start position:0% +values 0 and 1 so this is a Bernoulli +random variable and so the expectation + + align:start position:0% +random variable and so the expectation + + + align:start position:0% +random variable and so the expectation +of that random variable is just the + + align:start position:0% +of that random variable is just the + + + align:start position:0% +of that random variable is just the +probability that this random variable is + + align:start position:0% +probability that this random variable is + + + align:start position:0% +probability that this random variable is +equal to 1 but for the product to be + + align:start position:0% +equal to 1 but for the product to be + + + align:start position:0% +equal to 1 but for the product to be +equal to 1 the only way that this can + + align:start position:0% +equal to 1 the only way that this can + + + align:start position:0% +equal to 1 the only way that this can +happen is if both of these random + + align:start position:0% +happen is if both of these random + + + align:start position:0% +happen is if both of these random +variables happen to be equal to 1 let us + + align:start position:0% +variables happen to be equal to 1 let us + + + align:start position:0% +variables happen to be equal to 1 let us +now turn to the sequential description + + align:start position:0% +now turn to the sequential description + + + align:start position:0% +now turn to the sequential description +of the + + align:start position:0% +of the + + + align:start position:0% +of the +the probability that the first person + + align:start position:0% +the probability that the first person + + + align:start position:0% +the probability that the first person +gets their own hot bath and the second + + align:start position:0% +gets their own hot bath and the second + + + align:start position:0% +gets their own hot bath and the second +person gets her own hot back + + align:start position:0% +person gets her own hot back + + + align:start position:0% +person gets her own hot back +he's the probability that the first one + + align:start position:0% +he's the probability that the first one + + + align:start position:0% +he's the probability that the first one +gets their own hat back and then + + align:start position:0% +gets their own hat back and then + + + align:start position:0% +gets their own hat back and then +multiplied by the conditional + + align:start position:0% +multiplied by the conditional + + + align:start position:0% +multiplied by the conditional +probability that the second person gets + + align:start position:0% +probability that the second person gets + + + align:start position:0% +probability that the second person gets +their own hat back given that the first + + align:start position:0% +their own hat back given that the first + + + align:start position:0% +their own hat back given that the first +person got their own hat back + + align:start position:0% +person got their own hat back + + + align:start position:0% +person got their own hat back +what are these probabilities the + + align:start position:0% +what are these probabilities the + + + align:start position:0% +what are these probabilities the +probability that the person gets their + + align:start position:0% +probability that the person gets their + + + align:start position:0% +probability that the person gets their +own hat back is one over n given that + + align:start position:0% +own hat back is one over n given that + + + align:start position:0% +own hat back is one over n given that +person one got their own hat back person + + align:start position:0% +person one got their own hat back person + + + align:start position:0% +person one got their own hat back person +two is faced with a situation where + + align:start position:0% +two is faced with a situation where + + + align:start position:0% +two is faced with a situation where +there are n minus one available hats and + + align:start position:0% +there are n minus one available hats and + + + align:start position:0% +there are n minus one available hats and +one of those is that person's hat so the + + align:start position:0% +one of those is that person's hat so the + + + align:start position:0% +one of those is that person's hat so the +probability that person two will also + + align:start position:0% +probability that person two will also + + + align:start position:0% +probability that person two will also +pick his or her own hat is one over n + + align:start position:0% +pick his or her own hat is one over n + + + align:start position:0% +pick his or her own hat is one over n +minus one now we are in a position to + + align:start position:0% +minus one now we are in a position to + + + align:start position:0% +minus one now we are in a position to +calculate the expected value of x + + align:start position:0% +calculate the expected value of x + + + align:start position:0% +calculate the expected value of x +squared the expected value of x squared + + align:start position:0% + + + + align:start position:0% + +consists of the sum of n expected values + + align:start position:0% +consists of the sum of n expected values + + + align:start position:0% +consists of the sum of n expected values +each one of which is equal to 1 over n + + align:start position:0% + + + + align:start position:0% + +plus so many expected values because we + + align:start position:0% +plus so many expected values because we + + + align:start position:0% +plus so many expected values because we +have so many terms each one of which by + + align:start position:0% +have so many terms each one of which by + + + align:start position:0% +have so many terms each one of which by +this calculation is 1 over n times 1 + + align:start position:0% +this calculation is 1 over n times 1 + + + align:start position:0% +this calculation is 1 over n times 1 +over n minus 1 and we see that we get + + align:start position:0% +over n minus 1 and we see that we get + + + align:start position:0% +over n minus 1 and we see that we get +cancellations here and we obtain 1 plus + + align:start position:0% +cancellations here and we obtain 1 plus + + + align:start position:0% +cancellations here and we obtain 1 plus +1 which is equal to 2 on the other hand + + align:start position:0% +1 which is equal to 2 on the other hand + + + align:start position:0% +1 which is equal to 2 on the other hand +we have this term that we need to + + align:start position:0% +we have this term that we need to + + + align:start position:0% +we have this term that we need to +subtract we found previously that the + + align:start position:0% +subtract we found previously that the + + + align:start position:0% +subtract we found previously that the +expected value of x is equal to 1 so we + + align:start position:0% +expected value of x is equal to 1 so we + + + align:start position:0% +expected value of x is equal to 1 so we +need to subtract 1 and the final answer + + align:start position:0% +need to subtract 1 and the final answer + + + align:start position:0% +need to subtract 1 and the final answer +to our problem is that the variance of X + + align:start position:0% +to our problem is that the variance of X + + + align:start position:0% +to our problem is that the variance of X +is also equal to 1 + + align:start position:0% + + + + align:start position:0% + +so what we saw in this problem is that + + align:start position:0% +so what we saw in this problem is that + + + align:start position:0% +so what we saw in this problem is that +we can deal with quite complicated + + align:start position:0% +we can deal with quite complicated + + + align:start position:0% +we can deal with quite complicated +models but by breaking them down into + + align:start position:0% +models but by breaking them down into + + + align:start position:0% +models but by breaking them down into +more manageable pieces first breakdown + + align:start position:0% +more manageable pieces first breakdown + + + align:start position:0% +more manageable pieces first breakdown +the random variable X as a sum of + + align:start position:0% +the random variable X as a sum of + + + align:start position:0% +the random variable X as a sum of +different random variables then taking + + align:start position:0% +different random variables then taking + + + align:start position:0% +different random variables then taking +the square of this and break it down + + align:start position:0% +the square of this and break it down + + + align:start position:0% +the square of this and break it down +into a number of different terms and + + align:start position:0% +into a number of different terms and + + + align:start position:0% +into a number of different terms and +then by considering one term at a time + + align:start position:0% +then by considering one term at a time + + + align:start position:0% +then by considering one term at a time +we can often end up with the solutions + + align:start position:0% +we can often end up with the solutions + + + align:start position:0% +we can often end up with the solutions +or the answers to problems that would + + align:start position:0% +or the answers to problems that would + + + align:start position:0% +or the answers to problems that would +have been otherwise quite difficult \ No newline at end of file diff --git a/L8N_KZBHeIA.txt b/L8N_KZBHeIA.txt new file mode 100644 index 0000000000000000000000000000000000000000..161d9577c04b409d6f836d73fa2550a5a79f9ff9 --- /dev/null +++ b/L8N_KZBHeIA.txt @@ -0,0 +1,283 @@ +align:start position:0% + +hello I'm David Newman and when I served + + align:start position:0% +hello I'm David Newman and when I served + + + align:start position:0% +hello I'm David Newman and when I served +as NASA deputy administrator that's the + + align:start position:0% +as NASA deputy administrator that's the + + + align:start position:0% +as NASA deputy administrator that's the +number two I became very familiar with + + align:start position:0% +number two I became very familiar with + + + align:start position:0% +number two I became very familiar with +our Earth observing satellites which + + align:start position:0% +our Earth observing satellites which + + + align:start position:0% +our Earth observing satellites which +tell us about the vital signs of our + + align:start position:0% +tell us about the vital signs of our + + + align:start position:0% +tell us about the vital signs of our +planet which I call spaceship earth eyes + + align:start position:0% +planet which I call spaceship earth eyes + + + align:start position:0% +planet which I call spaceship earth eyes +on Earth from this global perspective + + align:start position:0% +on Earth from this global perspective + + + align:start position:0% +on Earth from this global perspective +I saw warming temperatures melting ice + + align:start position:0% +I saw warming temperatures melting ice + + + align:start position:0% +I saw warming temperatures melting ice +intensifying natural disasters climate + + align:start position:0% +intensifying natural disasters climate + + + align:start position:0% +intensifying natural disasters climate +change is real and if we're going to + + align:start position:0% +change is real and if we're going to + + + align:start position:0% +change is real and if we're going to +solve climate change the moonshot of our + + align:start position:0% +solve climate change the moonshot of our + + + align:start position:0% +solve climate change the moonshot of our +generation we need everyone on board + + align:start position:0% +generation we need everyone on board + + + align:start position:0% +generation we need everyone on board +that's why with the support of the MIT + + align:start position:0% +that's why with the support of the MIT + + + align:start position:0% +that's why with the support of the MIT +Portugal program a partners and I + + align:start position:0% +Portugal program a partners and I + + + align:start position:0% +Portugal program a partners and I +started earth DNA data into action for + + align:start position:0% +started earth DNA data into action for + + + align:start position:0% +started earth DNA data into action for +the earth we want to unite the whole + + align:start position:0% +the earth we want to unite the whole + + + align:start position:0% +the earth we want to unite the whole +world and creating a sustainable + + align:start position:0% +world and creating a sustainable + + + align:start position:0% +world and creating a sustainable +relationship between humans and nature + + align:start position:0% +relationship between humans and nature + + + align:start position:0% +relationship between humans and nature +and we're so happy to have you with us + + align:start position:0% +and we're so happy to have you with us + + + align:start position:0% +and we're so happy to have you with us +you'll be our astronauts traveling to + + align:start position:0% +you'll be our astronauts traveling to + + + align:start position:0% +you'll be our astronauts traveling to +places we could never reach by ourselves + + align:start position:0% +places we could never reach by ourselves + + + align:start position:0% +places we could never reach by ourselves +and will be your Mission Control + + align:start position:0% +and will be your Mission Control + + + align:start position:0% +and will be your Mission Control +providing you with the tools and + + align:start position:0% +providing you with the tools and + + + align:start position:0% +providing you with the tools and +guidance you need to make an impact at + + align:start position:0% +guidance you need to make an impact at + + + align:start position:0% +guidance you need to make an impact at +the schools around you you'll teach + + align:start position:0% +the schools around you you'll teach + + + align:start position:0% +the schools around you you'll teach +students students will teach families + + align:start position:0% +students students will teach families + + + align:start position:0% +students students will teach families +and families will demand action with + + align:start position:0% +and families will demand action with + + + align:start position:0% +and families will demand action with +your help we can reach a destination a + + align:start position:0% +your help we can reach a destination a + + + align:start position:0% +your help we can reach a destination a +world that works for a hundred percent + + align:start position:0% +world that works for a hundred percent + + + align:start position:0% +world that works for a hundred percent +of humanity without ecological offense + + align:start position:0% +of humanity without ecological offense + + + align:start position:0% +of humanity without ecological offense +we're ready for lift up and we're + + align:start position:0% +we're ready for lift up and we're + + + align:start position:0% +we're ready for lift up and we're +thrilled to have you on board so let's + + align:start position:0% +thrilled to have you on board so let's + + + align:start position:0% +thrilled to have you on board so let's +get started + + align:start position:0% + + + + align:start position:0% + +three two one launch + + align:start position:0% + + + + align:start position:0% + +you + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/LmiY4R6C2mM.txt b/LmiY4R6C2mM.txt new file mode 100644 index 0000000000000000000000000000000000000000..6ff8ac5844036396d8b08094e8032c13abb6517d --- /dev/null +++ b/LmiY4R6C2mM.txt @@ -0,0 +1,8307 @@ +align:start position:0% + +the following content is provided by MIT + + align:start position:0% +the following content is provided by MIT + + + align:start position:0% +the following content is provided by MIT +open courseware under a Creative Commons + + align:start position:0% +open courseware under a Creative Commons + + + align:start position:0% +open courseware under a Creative Commons +license additional information about our + + align:start position:0% +license additional information about our + + + align:start position:0% +license additional information about our +license and MIT open courseware in + + align:start position:0% +license and MIT open courseware in + + + align:start position:0% +license and MIT open courseware in +general is available at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu so you all should have uh + + align:start position:0% +ocw.mit.edu so you all should have uh + + + align:start position:0% +ocw.mit.edu so you all should have uh +these handouts ready to go now so let's + + align:start position:0% +these handouts ready to go now so let's + + + align:start position:0% +these handouts ready to go now so let's +review where we were last + + align:start position:0% +review where we were last + + + align:start position:0% +review where we were last +week so everyone uh can settle down a + + align:start position:0% +week so everyone uh can settle down a + + + align:start position:0% +week so everyone uh can settle down a +little bit you can discuss about who + + align:start position:0% +little bit you can discuss about who + + + align:start position:0% +little bit you can discuss about who +wants to be the top chemistry nature uh + + align:start position:0% +wants to be the top chemistry nature uh + + + align:start position:0% +wants to be the top chemistry nature uh +later on after class is over all right + + align:start position:0% +later on after class is over all right + + + align:start position:0% +later on after class is over all right +so octahedral + + align:start position:0% + + + + align:start position:0% + +case so here is our octahedral + + align:start position:0% +case so here is our octahedral + + + align:start position:0% +case so here is our octahedral +molecule and again Crystal field theory + + align:start position:0% +molecule and again Crystal field theory + + + align:start position:0% +molecule and again Crystal field theory +is just an explanation for things that + + align:start position:0% +is just an explanation for things that + + + align:start position:0% +is just an explanation for things that +are observed + + align:start position:0% +are observed + + + align:start position:0% +are observed +experimentally so it's a fairly simple + + align:start position:0% +experimentally so it's a fairly simple + + + align:start position:0% +experimentally so it's a fairly simple +Theory and if you go on to study + + align:start position:0% +Theory and if you go on to study + + + align:start position:0% +Theory and if you go on to study +chemistry and you'll take more inorganic + + align:start position:0% +chemistry and you'll take more inorganic + + + align:start position:0% +chemistry and you'll take more inorganic +chemistry later on you'll learn about + + align:start position:0% +chemistry later on you'll learn about + + + align:start position:0% +chemistry later on you'll learn about +more complicated theories but this is + + align:start position:0% +more complicated theories but this is + + + align:start position:0% +more complicated theories but this is +really simple so this Simple Theory just + + align:start position:0% +really simple so this Simple Theory just + + + align:start position:0% +really simple so this Simple Theory just +thinks about each Lian uh each uh small + + align:start position:0% +thinks about each Lian uh each uh small + + + align:start position:0% +thinks about each Lian uh each uh small +molecule like NH3 group bound to a metal + + align:start position:0% +molecule like NH3 group bound to a metal + + + align:start position:0% +molecule like NH3 group bound to a metal +the metal is in the center position that + + align:start position:0% +the metal is in the center position that + + + align:start position:0% +the metal is in the center position that +each Lian it considers as a negative + + align:start position:0% +each Lian it considers as a negative + + + align:start position:0% +each Lian it considers as a negative +Point charge and so then the theory + + align:start position:0% +Point charge and so then the theory + + + align:start position:0% +Point charge and so then the theory +looks at whether that Li as a negative + + align:start position:0% +looks at whether that Li as a negative + + + align:start position:0% +looks at whether that Li as a negative +Point charge is pointing toward one of + + align:start position:0% +Point charge is pointing toward one of + + + align:start position:0% +Point charge is pointing toward one of +the D orbitals so you need to know about + + align:start position:0% +the D orbitals so you need to know about + + + align:start position:0% +the D orbitals so you need to know about +the shapes of the D orbitals and you + + align:start position:0% +the shapes of the D orbitals and you + + + align:start position:0% +the shapes of the D orbitals and you +need to know about the the shapes of the + + align:start position:0% +need to know about the the shapes of the + + + align:start position:0% +need to know about the the shapes of the +coordination complexes and then you need + + align:start position:0% +coordination complexes and then you need + + + align:start position:0% +coordination complexes and then you need +to just ask yourself is that Lian + + align:start position:0% +to just ask yourself is that Lian + + + align:start position:0% +to just ask yourself is that Lian +pointing toward directly toward a d + + align:start position:0% +pointing toward directly toward a d + + + align:start position:0% +pointing toward directly toward a d +orbital if it is then it'll be + + align:start position:0% +orbital if it is then it'll be + + + align:start position:0% +orbital if it is then it'll be +destabilized if it's not then those + + align:start position:0% +destabilized if it's not then those + + + align:start position:0% +destabilized if it's not then those +orbitals will be stabilized and so + + align:start position:0% +orbitals will be stabilized and so + + + align:start position:0% +orbitals will be stabilized and so +you're all you're talking about the + + align:start position:0% +you're all you're talking about the + + + align:start position:0% +you're all you're talking about the +stabilization relative to a imaginary uh + + align:start position:0% +stabilization relative to a imaginary uh + + + align:start position:0% +stabilization relative to a imaginary uh +spherical Crystal field where lians are + + align:start position:0% +spherical Crystal field where lians are + + + align:start position:0% +spherical Crystal field where lians are +just sort of everywhere all around the + + align:start position:0% +just sort of everywhere all around the + + + align:start position:0% +just sort of everywhere all around the +center metal so you consider that as + + align:start position:0% +center metal so you consider that as + + + align:start position:0% +center metal so you consider that as +sort of your standard case where all of + + align:start position:0% +sort of your standard case where all of + + + align:start position:0% +sort of your standard case where all of +the D orbitals have the same energy but + + align:start position:0% +the D orbitals have the same energy but + + + align:start position:0% +the D orbitals have the same energy but +then when you consider those lians as + + align:start position:0% +then when you consider those lians as + + + align:start position:0% +then when you consider those lians as +negative point charges in particular + + align:start position:0% +negative point charges in particular + + + align:start position:0% +negative point charges in particular +locations some D orbitals then get + + align:start position:0% +locations some D orbitals then get + + + align:start position:0% +locations some D orbitals then get +destabilized and other ones get + + align:start position:0% +destabilized and other ones get + + + align:start position:0% +destabilized and other ones get +stabilized in terms of + + align:start position:0% +stabilized in terms of + + + align:start position:0% +stabilized in terms of +energy so in the octahedral case then + + align:start position:0% +energy so in the octahedral case then + + + align:start position:0% +energy so in the octahedral case then +and here's our little cartoon for the + + align:start position:0% +and here's our little cartoon for the + + + align:start position:0% +and here's our little cartoon for the +octahedral case where one Lian there + + align:start position:0% +octahedral case where one Lian there + + + align:start position:0% +octahedral case where one Lian there +lians along uh the Z axis lians along + + align:start position:0% +lians along uh the Z axis lians along + + + align:start position:0% +lians along uh the Z axis lians along +the x axis and lians along the Y AIS and + + align:start position:0% +the x axis and lians along the Y AIS and + + + align:start position:0% +the x axis and lians along the Y AIS and +so if you look at dx^ 2 - y^2 you see + + align:start position:0% +so if you look at dx^ 2 - y^2 you see + + + align:start position:0% +so if you look at dx^ 2 - y^2 you see +that the lians will be pointing directly + + align:start position:0% +that the lians will be pointing directly + + + align:start position:0% +that the lians will be pointing directly +toward these D orbitals because lians + + align:start position:0% +toward these D orbitals because lians + + + align:start position:0% +toward these D orbitals because lians +are coming in along Y and along X and so + + align:start position:0% +are coming in along Y and along X and so + + + align:start position:0% +are coming in along Y and along X and so +there'll be a lot of + + align:start position:0% +there'll be a lot of + + + align:start position:0% +there'll be a lot of +destabilization for D um Z squared you + + align:start position:0% +destabilization for D um Z squared you + + + align:start position:0% +destabilization for D um Z squared you +have lians pointing directly toward + + align:start position:0% +have lians pointing directly toward + + + align:start position:0% +have lians pointing directly toward +those orbitals as well along the Z axis + + align:start position:0% +those orbitals as well along the Z axis + + + align:start position:0% +those orbitals as well along the Z axis +so these have large repulsions due to + + align:start position:0% +so these have large repulsions due to + + + align:start position:0% +so these have large repulsions due to +the negative point charges those + + align:start position:0% +the negative point charges those + + + align:start position:0% +the negative point charges those +negative point charges are heading right + + align:start position:0% +negative point charges are heading right + + + align:start position:0% +negative point charges are heading right +toward those D + + align:start position:0% +toward those D + + + align:start position:0% +toward those D +orbitals and these two are degenerate + + align:start position:0% +orbitals and these two are degenerate + + + align:start position:0% +orbitals and these two are degenerate +with respect to each other they have the + + align:start position:0% +with respect to each other they have the + + + align:start position:0% +with respect to each other they have the +same energy the same amount of + + align:start position:0% +same energy the same amount of + + + align:start position:0% +same energy the same amount of +destabilization and these are + + align:start position:0% +destabilization and these are + + + align:start position:0% +destabilization and these are +destabilized compared to this other set + + align:start position:0% +destabilized compared to this other set + + + align:start position:0% +destabilized compared to this other set +of D orbitals and in this set of D + + align:start position:0% +of D orbitals and in this set of D + + + align:start position:0% +of D orbitals and in this set of D +orbitals none of the orbitals are on + + align:start position:0% +orbitals none of the orbitals are on + + + align:start position:0% +orbitals none of the orbitals are on +axis they're 45° off axis the negative + + align:start position:0% +axis they're 45° off axis the negative + + + align:start position:0% +axis they're 45° off axis the negative +point charges are on axis so there's not + + align:start position:0% +point charges are on axis so there's not + + + align:start position:0% +point charges are on axis so there's not +as much destabilization the lians aren't + + align:start position:0% +as much destabilization the lians aren't + + + align:start position:0% +as much destabilization the lians aren't +pointing directly toward + + align:start position:0% +pointing directly toward + + + align:start position:0% +pointing directly toward +any of these D orbitals so you have + + align:start position:0% +any of these D orbitals so you have + + + align:start position:0% +any of these D orbitals so you have +smaller + + align:start position:0% +smaller + + + align:start position:0% +smaller +repulsion all of these three are of the + + align:start position:0% +repulsion all of these three are of the + + + align:start position:0% +repulsion all of these three are of the +same energy they're + + align:start position:0% +same energy they're + + + align:start position:0% +same energy they're +degenerate and they're all stabilized + + align:start position:0% +degenerate and they're all stabilized + + + align:start position:0% +degenerate and they're all stabilized +compared to this set so that's what we + + align:start position:0% +compared to this set so that's what we + + + align:start position:0% +compared to this set so that's what we +talked about last week and we also + + align:start position:0% +talked about last week and we also + + + align:start position:0% +talked about last week and we also +talked about how you can draw an + + align:start position:0% +talked about how you can draw an + + + align:start position:0% +talked about how you can draw an +octahedral Crystal field splitting + + align:start position:0% +octahedral Crystal field splitting + + + align:start position:0% +octahedral Crystal field splitting +diagram and here's the average energy of + + align:start position:0% +diagram and here's the average energy of + + + align:start position:0% +diagram and here's the average energy of +the D orbitals with this sort of uh + + align:start position:0% +the D orbitals with this sort of uh + + + align:start position:0% +the D orbitals with this sort of uh +spherical Crystal field where ligans are + + align:start position:0% +spherical Crystal field where ligans are + + + align:start position:0% +spherical Crystal field where ligans are +everywhere and so when lians are + + align:start position:0% +everywhere and so when lians are + + + align:start position:0% +everywhere and so when lians are +everywhere all of the D orbitals have + + align:start position:0% +everywhere all of the D orbitals have + + + align:start position:0% +everywhere all of the D orbitals have +the same energy but then when you put + + align:start position:0% +the same energy but then when you put + + + align:start position:0% +the same energy but then when you put +the lians in their locations in the + + align:start position:0% +the lians in their locations in the + + + align:start position:0% +the lians in their locations in the +octahedral geometry framework then these + + align:start position:0% +octahedral geometry framework then these + + + align:start position:0% +octahedral geometry framework then these +two uh sets of orbitals DX dx^ 2 minus + + align:start position:0% +two uh sets of orbitals DX dx^ 2 minus + + + align:start position:0% +two uh sets of orbitals DX dx^ 2 minus +y^2 and dz^2 are up in energy they're + + align:start position:0% +y^2 and dz^2 are up in energy they're + + + align:start position:0% +y^2 and dz^2 are up in energy they're +destabilized and these three go down in + + align:start position:0% +destabilized and these three go down in + + + align:start position:0% +destabilized and these three go down in +energy and the overall energy of the + + align:start position:0% +energy and the overall energy of the + + + align:start position:0% +energy and the overall energy of the +system is maintained so here's the + + align:start position:0% +system is maintained so here's the + + + align:start position:0% +system is maintained so here's the +crystal + + align:start position:0% +crystal + + + align:start position:0% +crystal +Crystal field splitting energy for the + + align:start position:0% +Crystal field splitting energy for the + + + align:start position:0% +Crystal field splitting energy for the +octahedral case o for octahedral and so + + align:start position:0% +octahedral case o for octahedral and so + + + align:start position:0% +octahedral case o for octahedral and so +it's split two orbitals go up in energy + + align:start position:0% +it's split two orbitals go up in energy + + + align:start position:0% +it's split two orbitals go up in energy +so they go up by three fifths three go + + align:start position:0% +so they go up by three fifths three go + + + align:start position:0% +so they go up by three fifths three go +down so they go down by two fifths to + + align:start position:0% +down so they go down by two fifths to + + + align:start position:0% +down so they go down by two fifths to +maintain the overall uh energy of the + + align:start position:0% +maintain the overall uh energy of the + + + align:start position:0% +maintain the overall uh energy of the +system so that's what we talked about + + align:start position:0% +system so that's what we talked about + + + align:start position:0% +system so that's what we talked about +last time and I just wanted to review it + + align:start position:0% +last time and I just wanted to review it + + + align:start position:0% +last time and I just wanted to review it +because we're going to go on and talk + + align:start position:0% +because we're going to go on and talk + + + align:start position:0% +because we're going to go on and talk +about other types of geometry and of + + align:start position:0% +about other types of geometry and of + + + align:start position:0% +about other types of geometry and of +course uh remember that exam three is on + + align:start position:0% +course uh remember that exam three is on + + + align:start position:0% +course uh remember that exam three is on +Wednesday uh extra problems are posted + + align:start position:0% +Wednesday uh extra problems are posted + + + align:start position:0% +Wednesday uh extra problems are posted +um I will mention that I actually posted + + align:start position:0% +um I will mention that I actually posted + + + align:start position:0% +um I will mention that I actually posted +the original exam last year and the exam + + align:start position:0% +the original exam last year and the exam + + + align:start position:0% +the original exam last year and the exam +that people took was slightly easier + + align:start position:0% +that people took was slightly easier + + + align:start position:0% +that people took was slightly easier +than the one I posted I did that + + align:start position:0% +than the one I posted I did that + + + align:start position:0% +than the one I posted I did that +actually by mistake but it turns out + + align:start position:0% +actually by mistake but it turns out + + + align:start position:0% +actually by mistake but it turns out +that if you do that the exam that's + + align:start position:0% +that if you do that the exam that's + + + align:start position:0% +that if you do that the exam that's +posted is a better indicator of how well + + align:start position:0% +posted is a better indicator of how well + + + align:start position:0% +posted is a better indicator of how well +you'll do on this next exam because the + + align:start position:0% +you'll do on this next exam because the + + + align:start position:0% +you'll do on this next exam because the +final exam the third exam last year was + + align:start position:0% +final exam the third exam last year was + + + align:start position:0% +final exam the third exam last year was +a bit too easy um I.E too too easy means + + align:start position:0% +a bit too easy um I.E too too easy means + + + align:start position:0% +a bit too easy um I.E too too easy means +that you know the sort of outstanding + + align:start position:0% +that you know the sort of outstanding + + + align:start position:0% +that you know the sort of outstanding +category was like 98 and above and if + + align:start position:0% +category was like 98 and above and if + + + align:start position:0% +category was like 98 and above and if +you got a 97 then that was no longer + + align:start position:0% +you got a 97 then that was no longer + + + align:start position:0% +you got a 97 then that was no longer +outstanding so whether you got three + + align:start position:0% +outstanding so whether you got three + + + align:start position:0% +outstanding so whether you got three +significant figures wrong or two made it + + align:start position:0% +significant figures wrong or two made it + + + align:start position:0% +significant figures wrong or two made it +some difference in your grade that that + + align:start position:0% +some difference in your grade that that + + + align:start position:0% +some difference in your grade that that +clustering I don't like I like to have + + align:start position:0% +clustering I don't like I like to have + + + align:start position:0% +clustering I don't like I like to have +the average such that people's uh + + align:start position:0% +the average such that people's uh + + + align:start position:0% +the average such that people's uh +performance on the exam really indicates + + align:start position:0% +performance on the exam really indicates + + + align:start position:0% +performance on the exam really indicates +more how well they know the the material + + align:start position:0% +more how well they know the the material + + + align:start position:0% +more how well they know the the material +so the exam that's posted is actually + + align:start position:0% +so the exam that's posted is actually + + + align:start position:0% +so the exam that's posted is actually +the the better review so even though + + align:start position:0% +the the better review so even though + + + align:start position:0% +the the better review so even though +that was an accident I'll pretend I did + + align:start position:0% +that was an accident I'll pretend I did + + + align:start position:0% +that was an accident I'll pretend I did +it on purpose because it's a better + + align:start position:0% +it on purpose because it's a better + + + align:start position:0% +it on purpose because it's a better +thing so uh extra problems on So today + + align:start position:0% +thing so uh extra problems on So today + + + align:start position:0% +thing so uh extra problems on So today +we're going to finish up Crystal field + + align:start position:0% +we're going to finish up Crystal field + + + align:start position:0% +we're going to finish up Crystal field +Theory and then talk about the relevance + + align:start position:0% +Theory and then talk about the relevance + + + align:start position:0% +Theory and then talk about the relevance +of Crystal field Theory and the + + align:start position:0% +of Crystal field Theory and the + + + align:start position:0% +of Crystal field Theory and the +relevance comes into explaining the + + align:start position:0% +relevance comes into explaining the + + + align:start position:0% +relevance comes into explaining the +colors of these transition uh compounds + + align:start position:0% +colors of these transition uh compounds + + + align:start position:0% +colors of these transition uh compounds +so they have these me compounds with + + align:start position:0% +so they have these me compounds with + + + align:start position:0% +so they have these me compounds with +metals have some really spectacular + + align:start position:0% +metals have some really spectacular + + + align:start position:0% +metals have some really spectacular +colors and you can explain or + + align:start position:0% +colors and you can explain or + + + align:start position:0% +colors and you can explain or +rationalize some of these Colors by this + + align:start position:0% +rationalize some of these Colors by this + + + align:start position:0% +rationalize some of these Colors by this +really very simple Theory so that's fun + + align:start position:0% +really very simple Theory so that's fun + + + align:start position:0% +really very simple Theory so that's fun +and you can also explain some of the + + align:start position:0% +and you can also explain some of the + + + align:start position:0% +and you can also explain some of the +properties and magnetism of these + + align:start position:0% +properties and magnetism of these + + + align:start position:0% +properties and magnetism of these +compounds by this fairly simple Le + + align:start position:0% +compounds by this fairly simple Le + + + align:start position:0% +compounds by this fairly simple Le +Theory okay so let's look at the uh + + align:start position:0% +Theory okay so let's look at the uh + + + align:start position:0% +Theory okay so let's look at the uh +tetrahedral case + + align:start position:0% +tetrahedral case + + + align:start position:0% +tetrahedral case +now so here we have our tetrahedral + + align:start position:0% +now so here we have our tetrahedral + + + align:start position:0% +now so here we have our tetrahedral +molecule I'll try to kind of hold it up + + align:start position:0% +molecule I'll try to kind of hold it up + + + align:start position:0% +molecule I'll try to kind of hold it up +as it's displayed on the on the board so + + align:start position:0% +as it's displayed on the on the board so + + + align:start position:0% +as it's displayed on the on the board so +in this + + align:start position:0% +in this + + + align:start position:0% +in this +case we have two lians up one coming + + align:start position:0% +case we have two lians up one coming + + + align:start position:0% +case we have two lians up one coming +towards you one going back so coming to + + align:start position:0% +towards you one going back so coming to + + + align:start position:0% +towards you one going back so coming to +going coming towards you and going back + + align:start position:0% +going coming towards you and going back + + + align:start position:0% +going coming towards you and going back +and then we have two ligans in the plane + + align:start position:0% +and then we have two ligans in the plane + + + align:start position:0% +and then we have two ligans in the plane +of the screen and in this case the + + align:start position:0% +of the screen and in this case the + + + align:start position:0% +of the screen and in this case the +convention is to draw the Z axis coming + + align:start position:0% +convention is to draw the Z axis coming + + + align:start position:0% +convention is to draw the Z axis coming +down here and the Y AIS is kind of + + align:start position:0% +down here and the Y AIS is kind of + + + align:start position:0% +down here and the Y AIS is kind of +coming in from the side and the x- axis + + align:start position:0% +coming in from the side and the x- axis + + + align:start position:0% +coming in from the side and the x- axis +is coming out towards you here so that's + + align:start position:0% +is coming out towards you here so that's + + + align:start position:0% +is coming out towards you here so that's +uh what this what this picture + + align:start position:0% +uh what this what this picture + + + align:start position:0% +uh what this what this picture +indicates so the crystal field uh + + align:start position:0% +indicates so the crystal field uh + + + align:start position:0% +indicates so the crystal field uh +splitting energy tends to be smaller + + align:start position:0% +splitting energy tends to be smaller + + + align:start position:0% +splitting energy tends to be smaller +than the octahedral crystal field energy + + align:start position:0% +than the octahedral crystal field energy + + + align:start position:0% +than the octahedral crystal field energy +because because none of the point Lian + + align:start position:0% +because because none of the point Lian + + + align:start position:0% +because because none of the point Lian +point charges are really pointing toward + + align:start position:0% +point charges are really pointing toward + + + align:start position:0% +point charges are really pointing toward +any of the D orbitals and let's just + + align:start position:0% +any of the D orbitals and let's just + + + align:start position:0% +any of the D orbitals and let's just +take a look at all the D orbitals and + + align:start position:0% +take a look at all the D orbitals and + + + align:start position:0% +take a look at all the D orbitals and +consider then which ones are going to + + align:start position:0% +consider then which ones are going to + + + align:start position:0% +consider then which ones are going to +have more repulsion than other + + align:start position:0% +have more repulsion than other + + + align:start position:0% +have more repulsion than other +ones so if we go through and take a look + + align:start position:0% +ones so if we go through and take a look + + + align:start position:0% +ones so if we go through and take a look +at it and I've tried to indicate so here + + align:start position:0% +at it and I've tried to indicate so here + + + align:start position:0% +at it and I've tried to indicate so here +are our tetrahedral cases and here are + + align:start position:0% +are our tetrahedral cases and here are + + + align:start position:0% +are our tetrahedral cases and here are +our 5D orbitals and these little lines + + align:start position:0% +our 5D orbitals and these little lines + + + align:start position:0% +our 5D orbitals and these little lines +of the negative charge in the arrow is + + align:start position:0% +of the negative charge in the arrow is + + + align:start position:0% +of the negative charge in the arrow is +sort of a rough approximation of how + + align:start position:0% +sort of a rough approximation of how + + + align:start position:0% +sort of a rough approximation of how +those + + align:start position:0% +those + + + align:start position:0% +those +point charges are going to be coming in + + align:start position:0% +point charges are going to be coming in + + + align:start position:0% +point charges are going to be coming in +and pointing toward the D orbitals if + + align:start position:0% +and pointing toward the D orbitals if + + + align:start position:0% +and pointing toward the D orbitals if +they're coming in with this tetrahedral + + align:start position:0% +they're coming in with this tetrahedral + + + align:start position:0% +they're coming in with this tetrahedral +geometry is drawn and so you can see for + + align:start position:0% +geometry is drawn and so you can see for + + + align:start position:0% +geometry is drawn and so you can see for +the dx2 minus y^2 none of those lians + + align:start position:0% +the dx2 minus y^2 none of those lians + + + align:start position:0% +the dx2 minus y^2 none of those lians +are pointing right at any of the D + + align:start position:0% +are pointing right at any of the D + + + align:start position:0% +are pointing right at any of the D +orbitals NE and they're definitely not + + align:start position:0% +orbitals NE and they're definitely not + + + align:start position:0% +orbitals NE and they're definitely not +for the DZ squared either um a little + + align:start position:0% +for the DZ squared either um a little + + + align:start position:0% +for the DZ squared either um a little +bit more here but again not exactly uh + + align:start position:0% +bit more here but again not exactly uh + + + align:start position:0% +bit more here but again not exactly uh +pointing toward them although this + + align:start position:0% +pointing toward them although this + + + align:start position:0% +pointing toward them although this +picture looks like it is a little bit + + align:start position:0% +picture looks like it is a little bit + + + align:start position:0% +picture looks like it is a little bit +but again it's closer here but not + + align:start position:0% +but again it's closer here but not + + + align:start position:0% +but again it's closer here but not +exact so the result of this is that + + align:start position:0% +exact so the result of this is that + + + align:start position:0% +exact so the result of this is that +there's more a destabilization down here + + align:start position:0% +there's more a destabilization down here + + + align:start position:0% +there's more a destabilization down here +than there is up here so it turns out + + align:start position:0% +than there is up here so it turns out + + + align:start position:0% +than there is up here so it turns out +that this is then opposite of the + + align:start position:0% +that this is then opposite of the + + + align:start position:0% +that this is then opposite of the +octahedral case that we just talked + + align:start position:0% +octahedral case that we just talked + + + align:start position:0% +octahedral case that we just talked +about in octahedral these are the ones + + align:start position:0% +about in octahedral these are the ones + + + align:start position:0% +about in octahedral these are the ones +that are most + + align:start position:0% +that are most + + + align:start position:0% +that are most +destabilized in tetrahedral these are + + align:start position:0% +destabilized in tetrahedral these are + + + align:start position:0% +destabilized in tetrahedral these are +stabilized compared to the others so + + align:start position:0% +stabilized compared to the others so + + + align:start position:0% +stabilized compared to the others so +it's flipped exactly around + + align:start position:0% + + + + align:start position:0% + +so again there'd be more repulsion uh + + align:start position:0% +so again there'd be more repulsion uh + + + align:start position:0% +so again there'd be more repulsion uh +between the uh lens as negative point + + align:start position:0% +between the uh lens as negative point + + + align:start position:0% +between the uh lens as negative point +charges and the orbitals that are 45 + + align:start position:0% +charges and the orbitals that are 45 + + + align:start position:0% +charges and the orbitals that are 45 +degree off axis because here the lians + + align:start position:0% +degree off axis because here the lians + + + align:start position:0% +degree off axis because here the lians +are off axis and also the orbitals are + + align:start position:0% +are off axis and also the orbitals are + + + align:start position:0% +are off axis and also the orbitals are +off axis they're not directly pointing + + align:start position:0% +off axis they're not directly pointing + + + align:start position:0% +off axis they're not directly pointing +at each other but it's definitely worse + + align:start position:0% +at each other but it's definitely worse + + + align:start position:0% +at each other but it's definitely worse +down here uh these guys are really far + + align:start position:0% +down here uh these guys are really far + + + align:start position:0% +down here uh these guys are really far +away from those Lian point charges + + align:start position:0% + + + + align:start position:0% + +so these two will have the same energy + + align:start position:0% +so these two will have the same energy + + + align:start position:0% +so these two will have the same energy +with respect to each other they will + + align:start position:0% +with respect to each other they will + + + align:start position:0% +with respect to each other they will +also be degenerate as they were before + + align:start position:0% +also be degenerate as they were before + + + align:start position:0% +also be degenerate as they were before +and these three have the same energy + + align:start position:0% +and these three have the same energy + + + align:start position:0% +and these three have the same energy +with respect to each other they are also + + align:start position:0% +with respect to each other they are also + + + align:start position:0% +with respect to each other they are also +uh + + align:start position:0% + + + + align:start position:0% + +degenerate so then we can draw what the + + align:start position:0% +degenerate so then we can draw what the + + + align:start position:0% +degenerate so then we can draw what the +diagram will look like for the + + align:start position:0% +diagram will look like for the + + + align:start position:0% +diagram will look like for the +tetrahedral case so again here was the + + align:start position:0% +tetrahedral case so again here was the + + + align:start position:0% +tetrahedral case so again here was the +octahedral case now this is the + + align:start position:0% +octahedral case now this is the + + + align:start position:0% +octahedral case now this is the +tetrahedral case and so we have the + + align:start position:0% +tetrahedral case and so we have the + + + align:start position:0% +tetrahedral case and so we have the +splitting energy which is the energy + + align:start position:0% +splitting energy which is the energy + + + align:start position:0% +splitting energy which is the energy +that splits the the orbitals um based on + + align:start position:0% +that splits the the orbitals um based on + + + align:start position:0% +that splits the the orbitals um based on +these negative point charges compared to + + align:start position:0% +these negative point charges compared to + + + align:start position:0% +these negative point charges compared to +this uh theoretical uh spherical Crystal + + align:start position:0% +this uh theoretical uh spherical Crystal + + + align:start position:0% +this uh theoretical uh spherical Crystal +field and we also have a uh tetrahedral + + align:start position:0% +field and we also have a uh tetrahedral + + + align:start position:0% +field and we also have a uh tetrahedral +Crystal field splitting energy so that's + + align:start position:0% +Crystal field splitting energy so that's + + + align:start position:0% +Crystal field splitting energy so that's +uh drawn here now the first thing which + + align:start position:0% +uh drawn here now the first thing which + + + align:start position:0% +uh drawn here now the first thing which +I emphasized that I'll point out again + + align:start position:0% +I emphasized that I'll point out again + + + align:start position:0% +I emphasized that I'll point out again +is that these guys are flipped around so + + align:start position:0% +is that these guys are flipped around so + + + align:start position:0% +is that these guys are flipped around so +in instead of being um destabilized as + + align:start position:0% +in instead of being um destabilized as + + + align:start position:0% +in instead of being um destabilized as +they are in the octahedral crystal field + + align:start position:0% +they are in the octahedral crystal field + + + align:start position:0% +they are in the octahedral crystal field +the dx^ 2us y^2 and DZ squared are now + + align:start position:0% +the dx^ 2us y^2 and DZ squared are now + + + align:start position:0% +the dx^ 2us y^2 and DZ squared are now +stabilized compared to the other orbital + + align:start position:0% +stabilized compared to the other orbital + + + align:start position:0% +stabilized compared to the other orbital +set so they've switched positions these + + align:start position:0% +set so they've switched positions these + + + align:start position:0% +set so they've switched positions these +instead of being stabilized are now more + + align:start position:0% +instead of being stabilized are now more + + + align:start position:0% +instead of being stabilized are now more +destabilized so it's a direct + + align:start position:0% +destabilized so it's a direct + + + align:start position:0% +destabilized so it's a direct +switch there's also a little change in + + align:start position:0% +switch there's also a little change in + + + align:start position:0% +switch there's also a little change in +in nomenclature here so you can still + + align:start position:0% +in nomenclature here so you can still + + + align:start position:0% +in nomenclature here so you can still +refer to this orbital Set uh with the + + align:start position:0% +refer to this orbital Set uh with the + + + align:start position:0% +refer to this orbital Set uh with the +term e but instead of EG we have e and + + align:start position:0% +term e but instead of EG we have e and + + + align:start position:0% +term e but instead of EG we have e and +I'll just point out that the book has uh + + align:start position:0% +I'll just point out that the book has uh + + + align:start position:0% +I'll just point out that the book has uh +calls this e too and sometimes it calls + + align:start position:0% +calls this e too and sometimes it calls + + + align:start position:0% +calls this e too and sometimes it calls +an e it should just be uh e but this is + + align:start position:0% +an e it should just be uh e but this is + + + align:start position:0% +an e it should just be uh e but this is +kind of a small point but I don't want + + align:start position:0% +kind of a small point but I don't want + + + align:start position:0% +kind of a small point but I don't want +people to get confused by that and + + align:start position:0% +people to get confused by that and + + + align:start position:0% +people to get confused by that and +instead of t2g we have T2 up here so + + align:start position:0% +instead of t2g we have T2 up here so + + + align:start position:0% +instead of t2g we have T2 up here so +basically the the G uh term is gone in + + align:start position:0% +basically the the G uh term is gone in + + + align:start position:0% +basically the the G uh term is gone in +this case and you'll learn a lot more + + align:start position:0% +this case and you'll learn a lot more + + + align:start position:0% +this case and you'll learn a lot more +about that if you go on and and take + + align:start position:0% +about that if you go on and and take + + + align:start position:0% +about that if you go on and and take +more inorganic chemistry so these are + + align:start position:0% +more inorganic chemistry so these are + + + align:start position:0% +more inorganic chemistry so these are +flipped what else is + + align:start position:0% +flipped what else is + + + align:start position:0% +flipped what else is +true well the other thing that's true is + + align:start position:0% +true well the other thing that's true is + + + align:start position:0% +true well the other thing that's true is +that this splitting energy is much + + align:start position:0% +that this splitting energy is much + + + align:start position:0% +that this splitting energy is much +smaller in the tetrahedral case than it + + align:start position:0% +smaller in the tetrahedral case than it + + + align:start position:0% +smaller in the tetrahedral case than it +is in the octahedral case so here + + align:start position:0% +is in the octahedral case so here + + + align:start position:0% +is in the octahedral case so here +there's a much bigger uh distance + + align:start position:0% +there's a much bigger uh distance + + + align:start position:0% +there's a much bigger uh distance +between the orbitals here it's a much + + align:start position:0% +between the orbitals here it's a much + + + align:start position:0% +between the orbitals here it's a much +smaller distance and that is because in + + align:start position:0% +smaller distance and that is because in + + + align:start position:0% +smaller distance and that is because in +the octahedral case there are lians + + align:start position:0% +the octahedral case there are lians + + + align:start position:0% +the octahedral case there are lians +pointing directly at the D orbitals so + + align:start position:0% +pointing directly at the D orbitals so + + + align:start position:0% +pointing directly at the D orbitals so +in this uh framework for octahedral + + align:start position:0% +in this uh framework for octahedral + + + align:start position:0% +in this uh framework for octahedral +their ligans right along Z along X and + + align:start position:0% +their ligans right along Z along X and + + + align:start position:0% +their ligans right along Z along X and +along Y and so they're along all of the + + align:start position:0% +along Y and so they're along all of the + + + align:start position:0% +along Y and so they're along all of the +orbitals Al pointing directly toward the + + align:start position:0% +orbitals Al pointing directly toward the + + + align:start position:0% +orbitals Al pointing directly toward the +orbitals in the tetrahedral case not + + align:start position:0% +orbitals in the tetrahedral case not + + + align:start position:0% +orbitals in the tetrahedral case not +really pointing directly toward they're + + align:start position:0% +really pointing directly toward they're + + + align:start position:0% +really pointing directly toward they're +closer to some than to others but it's + + align:start position:0% +closer to some than to others but it's + + + align:start position:0% +closer to some than to others but it's +not as direct so result of that is that + + align:start position:0% +not as direct so result of that is that + + + align:start position:0% +not as direct so result of that is that +there's just not split that much there's + + align:start position:0% +there's just not split that much there's + + + align:start position:0% +there's just not split that much there's +not such a huge difference between the + + align:start position:0% +not such a huge difference between the + + + align:start position:0% +not such a huge difference between the +energy levels of the D orbitals in this + + align:start position:0% +energy levels of the D orbitals in this + + + align:start position:0% +energy levels of the D orbitals in this +case so what is what does this mean well + + align:start position:0% +case so what is what does this mean well + + + align:start position:0% +case so what is what does this mean well +it means that uh a lot of tetrahedral uh + + align:start position:0% +it means that uh a lot of tetrahedral uh + + + align:start position:0% +it means that uh a lot of tetrahedral uh +complexes because the splitting energy + + align:start position:0% +complexes because the splitting energy + + + align:start position:0% +complexes because the splitting energy +is small a lot of them are called high + + align:start position:0% +is small a lot of them are called high + + + align:start position:0% +is small a lot of them are called high +Spin and we talked about this uh last + + align:start position:0% +Spin and we talked about this uh last + + + align:start position:0% +Spin and we talked about this uh last +Monday that in high spin you have the + + align:start position:0% +Monday that in high spin you have the + + + align:start position:0% +Monday that in high spin you have the +maximum number of unpaired + + align:start position:0% +maximum number of unpaired + + + align:start position:0% +maximum number of unpaired +electrons and um because this and the + + align:start position:0% +electrons and um because this and the + + + align:start position:0% +electrons and um because this and the +purpose of this you can just assume that + + align:start position:0% +purpose of this you can just assume that + + + align:start position:0% +purpose of this you can just assume that +if you have a tetrahedral complex it + + align:start position:0% +if you have a tetrahedral complex it + + + align:start position:0% +if you have a tetrahedral complex it +will be high spin so that will come in + + align:start position:0% +will be high spin so that will come in + + + align:start position:0% +will be high spin so that will come in +into play when you figure out how to put + + align:start position:0% +into play when you figure out how to put + + + align:start position:0% +into play when you figure out how to put +your electrons into this diagram whether + + align:start position:0% +your electrons into this diagram whether + + + align:start position:0% +your electrons into this diagram whether +you put them in singly to the fullest + + align:start position:0% +you put them in singly to the fullest + + + align:start position:0% +you put them in singly to the fullest +extent possible without pairing or if + + align:start position:0% +extent possible without pairing or if + + + align:start position:0% +extent possible without pairing or if +you start to pair so in this case you + + align:start position:0% +you start to pair so in this case you + + + align:start position:0% +you start to pair so in this case you +can put them in singly to the fullest + + align:start position:0% +can put them in singly to the fullest + + + align:start position:0% +can put them in singly to the fullest +extent + + align:start position:0% + + + + align:start position:0% + +possible okay and um as I mentioned + + align:start position:0% +possible okay and um as I mentioned + + + align:start position:0% +possible okay and um as I mentioned +before the overall uh energy of the + + align:start position:0% +before the overall uh energy of the + + + align:start position:0% +before the overall uh energy of the +system is maintained so in this case you + + align:start position:0% +system is maintained so in this case you + + + align:start position:0% +system is maintained so in this case you +have two orbitals that go up in energy + + align:start position:0% +have two orbitals that go up in energy + + + align:start position:0% +have two orbitals that go up in energy +so they go up by three fifths three that + + align:start position:0% +so they go up by three fifths three that + + + align:start position:0% +so they go up by three fifths three that +come down so they go come down by two + + align:start position:0% +come down so they go come down by two + + + align:start position:0% +come down so they go come down by two +fifths in this case you have three going + + align:start position:0% +fifths in this case you have three going + + + align:start position:0% +fifths in this case you have three going +up so they'll go up by two fifths and + + align:start position:0% +up so they'll go up by two fifths and + + + align:start position:0% +up so they'll go up by two fifths and +you have two going down in energy so + + align:start position:0% +you have two going down in energy so + + + align:start position:0% +you have two going down in energy so +they'll go down by three fifths to + + align:start position:0% +they'll go down by three fifths to + + + align:start position:0% +they'll go down by three fifths to +maintain the overall energy of the + + align:start position:0% + + + + align:start position:0% + +system + + align:start position:0% +system + + + align:start position:0% +system +oops okay so that's the tetrahedral case + + align:start position:0% + + + + align:start position:0% + +so now let's consider Square + + align:start position:0% +so now let's consider Square + + + align:start position:0% +so now let's consider Square +planer so here we have our Square planer + + align:start position:0% +planer so here we have our Square planer + + + align:start position:0% +planer so here we have our Square planer +molecule and we have uh lians along the + + align:start position:0% +molecule and we have uh lians along the + + + align:start position:0% +molecule and we have uh lians along the +Y AIS lians along the xaxis pointing out + + align:start position:0% +Y AIS lians along the xaxis pointing out + + + align:start position:0% +Y AIS lians along the xaxis pointing out +towards you one and one going back + + align:start position:0% +towards you one and one going back + + + align:start position:0% +towards you one and one going back +behind and Z then is coming up and down + + align:start position:0% +behind and Z then is coming up and down + + + align:start position:0% +behind and Z then is coming up and down +in this plane so with this uh lians a y + + align:start position:0% +in this plane so with this uh lians a y + + + align:start position:0% +in this plane so with this uh lians a y +and a + + align:start position:0% +and a + + + align:start position:0% +and a +X which would you predict which orbitals + + align:start position:0% +X which would you predict which orbitals + + + align:start position:0% +X which would you predict which orbitals +do you predict would be destabilized the + + align:start position:0% + + + + align:start position:0% + +most D I heard dxy that's one what + + align:start position:0% + + + + align:start position:0% + +else dx2 minus y^2 right so those two so + + align:start position:0% +else dx2 minus y^2 right so those two so + + + align:start position:0% +else dx2 minus y^2 right so those two so +the ones that don't have the Z component + + align:start position:0% +the ones that don't have the Z component + + + align:start position:0% +the ones that don't have the Z component +in them so there's really not much + + align:start position:0% +in them so there's really not much + + + align:start position:0% +in them so there's really not much +destabilization along Z there no ligans + + align:start position:0% +destabilization along Z there no ligans + + + align:start position:0% +destabilization along Z there no ligans +along Z so orbitals that have amplitude + + align:start position:0% +along Z so orbitals that have amplitude + + + align:start position:0% +along Z so orbitals that have amplitude +along Z are not as affected so the ones + + align:start position:0% +along Z are not as affected so the ones + + + align:start position:0% +along Z are not as affected so the ones +that will be most affected are the + + align:start position:0% +that will be most affected are the + + + align:start position:0% +that will be most affected are the +orbitals that have component in the X + + align:start position:0% +orbitals that have component in the X + + + align:start position:0% +orbitals that have component in the X +and the y direction where the lians + + align:start position:0% +and the y direction where the lians + + + align:start position:0% +and the y direction where the lians +are so now we can consider the D + + align:start position:0% +are so now we can consider the D + + + align:start position:0% +are so now we can consider the D +orbitals and uh talk a little bit more + + align:start position:0% +orbitals and uh talk a little bit more + + + align:start position:0% +orbitals and uh talk a little bit more +about + + align:start position:0% +about + + + align:start position:0% +about +this so if we look at these two sets of + + align:start position:0% +this so if we look at these two sets of + + + align:start position:0% +this so if we look at these two sets of +orbitals now here as you uh correctly + + align:start position:0% +orbitals now here as you uh correctly + + + align:start position:0% +orbitals now here as you uh correctly +predicted there'll be lots of repulsion + + align:start position:0% +predicted there'll be lots of repulsion + + + align:start position:0% +predicted there'll be lots of repulsion +so the ligans are pointing directly at + + align:start position:0% +so the ligans are pointing directly at + + + align:start position:0% +so the ligans are pointing directly at +these de orbitals the lians are on axis + + align:start position:0% +these de orbitals the lians are on axis + + + align:start position:0% +these de orbitals the lians are on axis +the orbitals are on axis it's a direct + + align:start position:0% +the orbitals are on axis it's a direct + + + align:start position:0% +the orbitals are on axis it's a direct +hit so there's a lot of destabilization + + align:start position:0% +hit so there's a lot of destabilization + + + align:start position:0% +hit so there's a lot of destabilization +and this one now is going to be + + align:start position:0% +and this one now is going to be + + + align:start position:0% +and this one now is going to be +destabilized compared to all other ones + + align:start position:0% +destabilized compared to all other ones + + + align:start position:0% +destabilized compared to all other ones +so it's going to be by itself the most + + align:start position:0% +so it's going to be by itself the most + + + align:start position:0% +so it's going to be by itself the most +destabilized + + align:start position:0% +destabilized + + + align:start position:0% +destabilized +orbital DZ squared doesn't really have + + align:start position:0% +orbital DZ squared doesn't really have + + + align:start position:0% +orbital DZ squared doesn't really have +much destabilization + + align:start position:0% +much destabilization + + + align:start position:0% +much destabilization +uh at all in fact it'll be stabilized + + align:start position:0% +uh at all in fact it'll be stabilized + + + align:start position:0% +uh at all in fact it'll be stabilized +there's no lians along Z so there's no + + align:start position:0% +there's no lians along Z so there's no + + + align:start position:0% +there's no lians along Z so there's no +there's no real repulsion of the lians + + align:start position:0% +there's no real repulsion of the lians + + + align:start position:0% +there's no real repulsion of the lians +to uh DZ squared so it's going to be a + + align:start position:0% +to uh DZ squared so it's going to be a + + + align:start position:0% +to uh DZ squared so it's going to be a +lot less than for this guy and also less + + align:start position:0% +lot less than for this guy and also less + + + align:start position:0% +lot less than for this guy and also less +for the than + + align:start position:0% + + + + align:start position:0% + +dxy so we can draw this now put in two + + align:start position:0% +dxy so we can draw this now put in two + + + align:start position:0% +dxy so we can draw this now put in two +of the orbitals this one is going to be + + align:start position:0% +of the orbitals this one is going to be + + + align:start position:0% +of the orbitals this one is going to be +way up it's going to be by far the most + + align:start position:0% +way up it's going to be by far the most + + + align:start position:0% +way up it's going to be by far the most +destabilized + + align:start position:0% +destabilized + + + align:start position:0% +destabilized +so it's going to even go up from where + + align:start position:0% +so it's going to even go up from where + + + align:start position:0% +so it's going to even go up from where +it was in the octahedral case whereas + + align:start position:0% +it was in the octahedral case whereas + + + align:start position:0% +it was in the octahedral case whereas +dz^2 which was up here degenerate with + + align:start position:0% +dz^2 which was up here degenerate with + + + align:start position:0% +dz^2 which was up here degenerate with +dx^ 2 minus y^2 in the octahedral case + + align:start position:0% +dx^ 2 minus y^2 in the octahedral case + + + align:start position:0% +dx^ 2 minus y^2 in the octahedral case +is now going to drop way down so these + + align:start position:0% +is now going to drop way down so these + + + align:start position:0% +is now going to drop way down so these +aren't equivalent at all + + align:start position:0% +aren't equivalent at all + + + align:start position:0% +aren't equivalent at all +anymore and so this makes sense the + + align:start position:0% +anymore and so this makes sense the + + + align:start position:0% +anymore and so this makes sense the +difference between the octahedral + + align:start position:0% +difference between the octahedral + + + align:start position:0% +difference between the octahedral +geometry is that there were lians along + + align:start position:0% +geometry is that there were lians along + + + align:start position:0% +geometry is that there were lians along +Z Now the lians along Z are gone in the + + align:start position:0% +Z Now the lians along Z are gone in the + + + align:start position:0% +Z Now the lians along Z are gone in the +Square planer case so there's a big + + align:start position:0% +Square planer case so there's a big + + + align:start position:0% +Square planer case so there's a big +difference between these two orbital + + align:start position:0% +difference between these two orbital + + + align:start position:0% +difference between these two orbital +sets in terms of + + align:start position:0% +sets in terms of + + + align:start position:0% +sets in terms of +energy now let's look at these three so + + align:start position:0% +energy now let's look at these three so + + + align:start position:0% +energy now let's look at these three so +this one as people correctly predicted + + align:start position:0% +this one as people correctly predicted + + + align:start position:0% +this one as people correctly predicted +is going to have a lot more repulsion + + align:start position:0% +is going to have a lot more repulsion + + + align:start position:0% +is going to have a lot more repulsion +than either of these because we have um + + align:start position:0% +than either of these because we have um + + + align:start position:0% +than either of these because we have um +amp the orbitals are have maximum + + align:start position:0% +amp the orbitals are have maximum + + + align:start position:0% +amp the orbitals are have maximum +amplitude along um X and Y they're + + align:start position:0% +amplitude along um X and Y they're + + + align:start position:0% +amplitude along um X and Y they're +actually 45 degrees off X and Y but + + align:start position:0% +actually 45 degrees off X and Y but + + + align:start position:0% +actually 45 degrees off X and Y but +still we don't have anything in the in + + align:start position:0% +still we don't have anything in the in + + + align:start position:0% +still we don't have anything in the in +the Z component here so this will be um + + align:start position:0% +the Z component here so this will be um + + + align:start position:0% +the Z component here so this will be um +this will be destabilized compared to + + align:start position:0% +this will be destabilized compared to + + + align:start position:0% +this will be destabilized compared to +these two and these two are stabilized + + align:start position:0% +these two and these two are stabilized + + + align:start position:0% +these two and these two are stabilized +compared to the D orbitals dxy D x^2 + + align:start position:0% +compared to the D orbitals dxy D x^2 + + + align:start position:0% +compared to the D orbitals dxy D x^2 +minus + + align:start position:0% +minus + + + align:start position:0% +minus +y^2 so now we can go and take a look at + + align:start position:0% +y^2 so now we can go and take a look at + + + align:start position:0% +y^2 so now we can go and take a look at +where these would be positioned + + align:start position:0% +where these would be positioned + + + align:start position:0% +where these would be positioned +approximately so if we look at this one + + align:start position:0% +approximately so if we look at this one + + + align:start position:0% +approximately so if we look at this one +it's not nearly as destabilized as this + + align:start position:0% +it's not nearly as destabilized as this + + + align:start position:0% +it's not nearly as destabilized as this +one but still it's a bit destabilized + + align:start position:0% +one but still it's a bit destabilized + + + align:start position:0% +one but still it's a bit destabilized +and above this this is this one is uh + + align:start position:0% +and above this this is this one is uh + + + align:start position:0% +and above this this is this one is uh +lower in energy and if you consider the + + align:start position:0% +lower in energy and if you consider the + + + align:start position:0% +lower in energy and if you consider the +here again dx^ 2us y^2 the lians are + + align:start position:0% +here again dx^ 2us y^2 the lians are + + + align:start position:0% +here again dx^ 2us y^2 the lians are +pointing directly at the orbitals it's + + align:start position:0% +pointing directly at the orbitals it's + + + align:start position:0% +pointing directly at the orbitals it's +on axis here it's 45 Dee off axis so + + align:start position:0% +on axis here it's 45 Dee off axis so + + + align:start position:0% +on axis here it's 45 Dee off axis so +it's not as destabilized but still it's + + align:start position:0% +it's not as destabilized but still it's + + + align:start position:0% +it's not as destabilized but still it's +up above where it was in the octahedral + + align:start position:0% +up above where it was in the octahedral + + + align:start position:0% +up above where it was in the octahedral +case and then finally these two guys uh + + align:start position:0% +case and then finally these two guys uh + + + align:start position:0% +case and then finally these two guys uh +don't have are going to be stabilized + + align:start position:0% +don't have are going to be stabilized + + + align:start position:0% +don't have are going to be stabilized +compared to this uh theoretical uh + + align:start position:0% +compared to this uh theoretical uh + + + align:start position:0% +compared to this uh theoretical uh +spherical Crystal field so they're going + + align:start position:0% +spherical Crystal field so they're going + + + align:start position:0% +spherical Crystal field so they're going +to be somewhere down down + + align:start position:0% +to be somewhere down down + + + align:start position:0% +to be somewhere down down +here so the big points here then are + + align:start position:0% +here so the big points here then are + + + align:start position:0% +here so the big points here then are +that when you get rid compared to the + + align:start position:0% +that when you get rid compared to the + + + align:start position:0% +that when you get rid compared to the +octahedral case you get rid of the + + align:start position:0% +octahedral case you get rid of the + + + align:start position:0% +octahedral case you get rid of the +ligans along Z this guy shoots up this + + align:start position:0% +ligans along Z this guy shoots up this + + + align:start position:0% +ligans along Z this guy shoots up this +one comes down it's + + align:start position:0% +one comes down it's + + + align:start position:0% +one comes down it's +stabilized uh the other D orbital that + + align:start position:0% +stabilized uh the other D orbital that + + + align:start position:0% +stabilized uh the other D orbital that +has maximum components along X and Y + + align:start position:0% +has maximum components along X and Y + + + align:start position:0% +has maximum components along X and Y +which is where those lians are goes up a + + align:start position:0% +which is where those lians are goes up a + + + align:start position:0% +which is where those lians are goes up a +little so these three are all sort of + + align:start position:0% +little so these three are all sort of + + + align:start position:0% +little so these three are all sort of +stabilized these two are destabilized + + align:start position:0% +stabilized these two are destabilized + + + align:start position:0% +stabilized these two are destabilized +but this one is destabilized quite a bit + + align:start position:0% +but this one is destabilized quite a bit + + + align:start position:0% +but this one is destabilized quite a bit +more these also will have + + align:start position:0% +more these also will have + + + align:start position:0% +more these also will have +um you can draw sort of splitting + + align:start position:0% +um you can draw sort of splitting + + + align:start position:0% +um you can draw sort of splitting +energies here but that's just too + + align:start position:0% +energies here but that's just too + + + align:start position:0% +energies here but that's just too +complicated we're only going to do this + + align:start position:0% +complicated we're only going to do this + + + align:start position:0% +complicated we're only going to do this +with the octahedral and tetrahedral case + + align:start position:0% +with the octahedral and tetrahedral case + + + align:start position:0% +with the octahedral and tetrahedral case +uh because there's many more layers here + + align:start position:0% +uh because there's many more layers here + + + align:start position:0% +uh because there's many more layers here +and uh these are a little bit different + + align:start position:0% +and uh these are a little bit different + + + align:start position:0% +and uh these are a little bit different +so all all you need to know is sort of + + align:start position:0% +so all all you need to know is sort of + + + align:start position:0% +so all all you need to know is sort of +this relative uh ratio this is the most + + align:start position:0% +this relative uh ratio this is the most + + + align:start position:0% +this relative uh ratio this is the most +destabilized this is next these guys are + + align:start position:0% +destabilized this is next these guys are + + + align:start position:0% +destabilized this is next these guys are +stabilized that's all you need to know + + align:start position:0% +stabilized that's all you need to know + + + align:start position:0% +stabilized that's all you need to know +we didn't we're not going to draw uh + + align:start position:0% +we didn't we're not going to draw uh + + + align:start position:0% +we didn't we're not going to draw uh +splitting energies going up by uh 1 and + + align:start position:0% +splitting energies going up by uh 1 and + + + align:start position:0% +splitting energies going up by uh 1 and +things like that for this case but + + align:start position:0% +things like that for this case but + + + align:start position:0% +things like that for this case but +you'll hear about this more if you go on + + align:start position:0% +you'll hear about this more if you go on + + + align:start position:0% +you'll hear about this more if you go on +in uh in chemistry so what I expect you + + align:start position:0% +in uh in chemistry so what I expect you + + + align:start position:0% +in uh in chemistry so what I expect you +to know is to be able to rationalize if + + align:start position:0% +to know is to be able to rationalize if + + + align:start position:0% +to know is to be able to rationalize if +you know something about the shape of a + + align:start position:0% +you know something about the shape of a + + + align:start position:0% +you know something about the shape of a +molecule suppose you had a linear + + align:start position:0% +molecule suppose you had a linear + + + align:start position:0% +molecule suppose you had a linear +molecule along the + + align:start position:0% +molecule along the + + + align:start position:0% +molecule along the +z-axis uh good test question uh might be + + align:start position:0% +z-axis uh good test question uh might be + + + align:start position:0% +z-axis uh good test question uh might be +which orbitals would be the most + + align:start position:0% +which orbitals would be the most + + + align:start position:0% +which orbitals would be the most +destabilized if you're linear along Z + + align:start position:0% +destabilized if you're linear along Z + + + align:start position:0% +destabilized if you're linear along Z +for example so you should be able to + + align:start position:0% +for example so you should be able to + + + align:start position:0% +for example so you should be able to +think about the shapes of the D orbitals + + align:start position:0% +think about the shapes of the D orbitals + + + align:start position:0% +think about the shapes of the D orbitals +think about the shapes of the molecules + + align:start position:0% +think about the shapes of the molecules + + + align:start position:0% +think about the shapes of the molecules +and predict the orbitals with the most + + align:start position:0% +and predict the orbitals with the most + + + align:start position:0% +and predict the orbitals with the most +stabilization and the most + + align:start position:0% +stabilization and the most + + + align:start position:0% +stabilization and the most +destabilization and to be able to + + align:start position:0% +destabilization and to be able to + + + align:start position:0% +destabilization and to be able to +explain your rationale for predicting uh + + align:start position:0% +explain your rationale for predicting uh + + + align:start position:0% +explain your rationale for predicting uh +these splitting + + align:start position:0% + + + + align:start position:0% + +diagrams now we're going to talk about + + align:start position:0% +diagrams now we're going to talk about + + + align:start position:0% +diagrams now we're going to talk about +how these diagrams and thinking about + + align:start position:0% +how these diagrams and thinking about + + + align:start position:0% +how these diagrams and thinking about +the splitting of the D orbitals can + + align:start position:0% +the splitting of the D orbitals can + + + align:start position:0% +the splitting of the D orbitals can +explain the beautiful colors of these + + align:start position:0% +explain the beautiful colors of these + + + align:start position:0% +explain the beautiful colors of these +coordination uh + + align:start position:0% + + + + align:start position:0% + +complexes so let's go back to the + + align:start position:0% +complexes so let's go back to the + + + align:start position:0% +complexes so let's go back to the +octahedral case for a minute and talk + + align:start position:0% +octahedral case for a minute and talk + + + align:start position:0% +octahedral case for a minute and talk +about two different octahedral + + align:start position:0% +about two different octahedral + + + align:start position:0% +about two different octahedral +complexes so we have iron plus three in + + align:start position:0% +complexes so we have iron plus three in + + + align:start position:0% +complexes so we have iron plus three in +two different complexes we have a high + + align:start position:0% +two different complexes we have a high + + + align:start position:0% +two different complexes we have a high +spin state with iron and six water + + align:start position:0% +spin state with iron and six water + + + align:start position:0% +spin state with iron and six water +ligans and a low spin molecule + + align:start position:0% +ligans and a low spin molecule + + + align:start position:0% +ligans and a low spin molecule +coordination compound with iron and six + + align:start position:0% +coordination compound with iron and six + + + align:start position:0% +coordination compound with iron and six +CID lians so the first thing you're + + align:start position:0% +CID lians so the first thing you're + + + align:start position:0% +CID lians so the first thing you're +going to do if you're going to be + + align:start position:0% +going to do if you're going to be + + + align:start position:0% +going to do if you're going to be +talking about the splitting is to figure + + align:start position:0% +talking about the splitting is to figure + + + align:start position:0% +talking about the splitting is to figure +out how many electrons you're talking + + align:start position:0% +out how many electrons you're talking + + + align:start position:0% +out how many electrons you're talking +about or come up with the D electron + + align:start position:0% +about or come up with the D electron + + + align:start position:0% +about or come up with the D electron +count so let's let's do + + align:start position:0% +count so let's let's do + + + align:start position:0% +count so let's let's do +that so if we have iron with six water + + align:start position:0% + + + + align:start position:0% + +lians the overall charge on that is + + align:start position:0% +lians the overall charge on that is + + + align:start position:0% +lians the overall charge on that is +3+ so what is going to be our um and + + align:start position:0% +3+ so what is going to be our um and + + + align:start position:0% +3+ so what is going to be our um and +this is on the board too but what what + + align:start position:0% +this is on the board too but what what + + + align:start position:0% +this is on the board too but what what +will be the the oxidation number of + + align:start position:0% +will be the the oxidation number of + + + align:start position:0% +will be the the oxidation number of +iron plus + + align:start position:0% +iron plus + + + align:start position:0% +iron plus +three this is zero and so it all has to + + align:start position:0% +three this is zero and so it all has to + + + align:start position:0% +three this is zero and so it all has to +equal plus + + align:start position:0% +equal plus + + + align:start position:0% +equal plus +three so then the + + align:start position:0% +three so then the + + + align:start position:0% +three so then the +dcount is going to be equal to I'll put + + align:start position:0% +dcount is going to be equal to I'll put + + + align:start position:0% +dcount is going to be equal to I'll put +up a periodic table so the dcount will + + align:start position:0% +up a periodic table so the dcount will + + + align:start position:0% +up a periodic table so the dcount will +be equal to + + align:start position:0% +be equal to + + + align:start position:0% +be equal to +what five right so we look up the group + + align:start position:0% +what five right so we look up the group + + + align:start position:0% +what five right so we look up the group +number is 8 minus 3 is going to be + + align:start position:0% +number is 8 minus 3 is going to be + + + align:start position:0% +number is 8 minus 3 is going to be +five and our other iron complex will be + + align:start position:0% +five and our other iron complex will be + + + align:start position:0% +five and our other iron complex will be +the + + align:start position:0% + + + + align:start position:0% + +same so this one has a charge of minus + + align:start position:0% +same so this one has a charge of minus + + + align:start position:0% +same so this one has a charge of minus +three cyanide is + + align:start position:0% +three cyanide is + + + align:start position:0% +three cyanide is +what + + align:start position:0% +what + + + align:start position:0% +what +minus1 so iron would also have to be+ + + align:start position:0% +minus1 so iron would also have to be+ + + + align:start position:0% +minus1 so iron would also have to be+ +three to get the correct overall charge + + align:start position:0% +three to get the correct overall charge + + + align:start position:0% +three to get the correct overall charge +so our dcount over here as well is going + + align:start position:0% +so our dcount over here as well is going + + + align:start position:0% +so our dcount over here as well is going +to be + + align:start position:0% +to be + + + align:start position:0% +to be +D5 so we have the same number of + + align:start position:0% +D5 so we have the same number of + + + align:start position:0% +D5 so we have the same number of +electrons uh that we need to put into + + align:start position:0% +electrons uh that we need to put into + + + align:start position:0% +electrons uh that we need to put into +two different + + align:start position:0% + + + + align:start position:0% + +diagrams so we have one this is our high + + align:start position:0% +diagrams so we have one this is our high + + + align:start position:0% +diagrams so we have one this is our high +spin + + align:start position:0% + + + + align:start position:0% + +case and so we can draw the crystal + + align:start position:0% +case and so we can draw the crystal + + + align:start position:0% +case and so we can draw the crystal +field splitting diagram for the high + + align:start position:0% + + + + align:start position:0% + +Spin + + align:start position:0% +Spin + + + align:start position:0% +Spin +and put in our + + align:start position:0% + + + + align:start position:0% + +orbitals dx^ 2 - y^ 2 dz^2 + + align:start position:0% + + + + align:start position:0% + +we have our octahedral Crystal field + + align:start position:0% +we have our octahedral Crystal field + + + align:start position:0% +we have our octahedral Crystal field +splitting energy we're going + + align:start position:0% +splitting energy we're going + + + align:start position:0% +splitting energy we're going +up by 3 + + align:start position:0% +up by 3 + + + align:start position:0% +up by 3 +fifths and down by two + + align:start position:0% +fifths and down by two + + + align:start position:0% +fifths and down by two +fths for these compared to this uh + + align:start position:0% + + + + align:start position:0% + +theoretical Crystal + + align:start position:0% +theoretical Crystal + + + align:start position:0% +theoretical Crystal +field and then we have our low spin + + align:start position:0% + + + + align:start position:0% + +case and and + + align:start position:0% +case and and + + + align:start position:0% +case and and +again + + align:start position:0% + + + + align:start position:0% + +see so in our low spin case we have a + + align:start position:0% +see so in our low spin case we have a + + + align:start position:0% +see so in our low spin case we have a +larger splitting + + align:start position:0% + + + + align:start position:0% + +energy and again some are going to go up + + align:start position:0% +energy and again some are going to go up + + + align:start position:0% +energy and again some are going to go up +by 3 + + align:start position:0% +by 3 + + + align:start position:0% +by 3 +fths and these two three will go down by + + align:start position:0% +fths and these two three will go down by + + + align:start position:0% +fths and these two three will go down by +two fths + + align:start position:0% +two fths + + + align:start position:0% +two fths +all right so now we need to put in our + + align:start position:0% +all right so now we need to put in our + + + align:start position:0% +all right so now we need to put in our +five + + align:start position:0% +five + + + align:start position:0% +five +electrons so how am I going to uh put + + align:start position:0% +electrons so how am I going to uh put + + + align:start position:0% +electrons so how am I going to uh put +them in + + align:start position:0% +them in + + + align:start position:0% +them in +here will I fill up all the orbital all + + align:start position:0% +here will I fill up all the orbital all + + + align:start position:0% +here will I fill up all the orbital all +of the different energy levels with one + + align:start position:0% +of the different energy levels with one + + + align:start position:0% +of the different energy levels with one +before I pair or will I start to pair in + + align:start position:0% +before I pair or will I start to pair in + + + align:start position:0% +before I pair or will I start to pair in +the lower + + align:start position:0% +the lower + + + align:start position:0% +the lower +first we're going to put them in + + align:start position:0% +first we're going to put them in + + + align:start position:0% +first we're going to put them in +everywhere first so we'll put all five + + align:start position:0% +everywhere first so we'll put all five + + + align:start position:0% +everywhere first so we'll put all five +electrons we'll put one in each of the + + align:start position:0% +electrons we'll put one in each of the + + + align:start position:0% +electrons we'll put one in each of the +orbitals so I'm going to place them + + align:start position:0% +orbitals so I'm going to place them + + + align:start position:0% +orbitals so I'm going to place them +singly in and that's because in this + + align:start position:0% +singly in and that's because in this + + + align:start position:0% +singly in and that's because in this +case the splitting energy is + + align:start position:0% +case the splitting energy is + + + align:start position:0% +case the splitting energy is +small and since it's small it's less + + align:start position:0% +small and since it's small it's less + + + align:start position:0% +small and since it's small it's less +than the pairing + + align:start position:0% + + + + align:start position:0% + +energy so the pairing energy is the + + align:start position:0% +energy so the pairing energy is the + + + align:start position:0% +energy so the pairing energy is the +energy required to pair up these + + align:start position:0% +energy required to pair up these + + + align:start position:0% +energy required to pair up these +electrons there's a certain amount of + + align:start position:0% +electrons there's a certain amount of + + + align:start position:0% +electrons there's a certain amount of +repulsion all of the electrons would + + align:start position:0% +repulsion all of the electrons would + + + align:start position:0% +repulsion all of the electrons would +love to be alone in their orbital they'd + + align:start position:0% +love to be alone in their orbital they'd + + + align:start position:0% +love to be alone in their orbital they'd +prefer not for you to put another + + align:start position:0% +prefer not for you to put another + + + align:start position:0% +prefer not for you to put another +electron R in so there's a certain + + align:start position:0% +electron R in so there's a certain + + + align:start position:0% +electron R in so there's a certain +amount of energy required to do this if + + align:start position:0% +amount of energy required to do this if + + + align:start position:0% +amount of energy required to do this if +the energy level between the D orbitals + + align:start position:0% +the energy level between the D orbitals + + + align:start position:0% +the energy level between the D orbitals +is small then it's uh you put them all + + align:start position:0% +is small then it's uh you put them all + + + align:start position:0% +is small then it's uh you put them all +in singly and uh don't pair until you + + align:start position:0% +in singly and uh don't pair until you + + + align:start position:0% +in singly and uh don't pair until you +absolutely have to this is referred to + + align:start position:0% +absolutely have to this is referred to + + + align:start position:0% +absolutely have to this is referred to +as the high spin case where you have the + + align:start position:0% +as the high spin case where you have the + + + align:start position:0% +as the high spin case where you have the +most maximum number of unpaired + + align:start position:0% +most maximum number of unpaired + + + align:start position:0% +most maximum number of unpaired +electrons so in this case we have a + + align:start position:0% +electrons so in this case we have a + + + align:start position:0% +electrons so in this case we have a +large energy so that energy then is + + align:start position:0% +large energy so that energy then is + + + align:start position:0% +large energy so that energy then is +greater than the energy required to pair + + align:start position:0% +greater than the energy required to pair + + + align:start position:0% +greater than the energy required to pair +PE or the pairing energy so now we're + + align:start position:0% +PE or the pairing energy so now we're + + + align:start position:0% +PE or the pairing energy so now we're +going to put them all into the bottom + + align:start position:0% +going to put them all into the bottom + + + align:start position:0% +going to put them all into the bottom +until we have to go to the top so we'll + + align:start position:0% +until we have to go to the top so we'll + + + align:start position:0% +until we have to go to the top so we'll +first start out putting them in singly + + align:start position:0% +first start out putting them in singly + + + align:start position:0% +first start out putting them in singly +one two 3 and then we'll start pairing + + align:start position:0% +one two 3 and then we'll start pairing + + + align:start position:0% +one two 3 and then we'll start pairing +for + + align:start position:0% +for + + + align:start position:0% +for +five so now we fill up this bottom uh + + align:start position:0% +five so now we fill up this bottom uh + + + align:start position:0% +five so now we fill up this bottom uh +set I should put in the + + align:start position:0% +set I should put in the + + + align:start position:0% +set I should put in the +t2g and the + + align:start position:0% +t2g and the + + + align:start position:0% +t2g and the +EG labels + + align:start position:0% +EG labels + + + align:start position:0% +EG labels +so we'll put them in this bottom set in + + align:start position:0% +so we'll put them in this bottom set in + + + align:start position:0% +so we'll put them in this bottom set in +t2g until we have to go up to EG because + + align:start position:0% +t2g until we have to go up to EG because + + + align:start position:0% +t2g until we have to go up to EG because +this is a big energy difference and you + + align:start position:0% +this is a big energy difference and you + + + align:start position:0% +this is a big energy difference and you +don't want to do that until you have + + align:start position:0% + + + + align:start position:0% + +to all right so now we can look at the + + align:start position:0% +to all right so now we can look at the + + + align:start position:0% +to all right so now we can look at the +uh D electron count so where the + + align:start position:0% +uh D electron count so where the + + + align:start position:0% +uh D electron count so where the +electrons are so here it's + + align:start position:0% +electrons are so here it's + + + align:start position:0% +electrons are so here it's +t2g 3 there are three in the bottom and + + align:start position:0% +t2g 3 there are three in the bottom and + + + align:start position:0% +t2g 3 there are three in the bottom and +in EG there are + + align:start position:0% +in EG there are + + + align:start position:0% +in EG there are +two and over here in t2g we have five + + align:start position:0% +two and over here in t2g we have five + + + align:start position:0% +two and over here in t2g we have five +there's none in EG so those are our Del + + align:start position:0% +there's none in EG so those are our Del + + + align:start position:0% +there's none in EG so those are our Del +electron + + align:start position:0% +electron + + + align:start position:0% +electron +counts and then we can calculate the + + align:start position:0% +counts and then we can calculate the + + + align:start position:0% +counts and then we can calculate the +crystal field stabilization energy which + + align:start position:0% +crystal field stabilization energy which + + + align:start position:0% +crystal field stabilization energy which +shouldn't be confused with the splitting + + align:start position:0% +shouldn't be confused with the splitting + + + align:start position:0% +shouldn't be confused with the splitting +energy so this considers how much + + align:start position:0% +energy so this considers how much + + + align:start position:0% +energy so this considers how much +stabilization you have as a result of + + align:start position:0% +stabilization you have as a result of + + + align:start position:0% +stabilization you have as a result of +the fact that the D orbitals are split + + align:start position:0% +the fact that the D orbitals are split + + + align:start position:0% +the fact that the D orbitals are split +in + + align:start position:0% +in + + + align:start position:0% +in +energy so in this case you want to count + + align:start position:0% +energy so in this case you want to count + + + align:start position:0% +energy so in this case you want to count +up how many are in the lower energy + + align:start position:0% +up how many are in the lower energy + + + align:start position:0% +up how many are in the lower energy +levels so they're three down + + align:start position:0% +levels so they're three down + + + align:start position:0% +levels so they're three down +here so 3 * - 25s the octahedral crystal + + align:start position:0% +here so 3 * - 25s the octahedral crystal + + + align:start position:0% +here so 3 * - 25s the octahedral crystal +field splitting energy and you have two + + align:start position:0% +field splitting energy and you have two + + + align:start position:0% +field splitting energy and you have two +above so two are up in energy by three F + + align:start position:0% +above so two are up in energy by three F + + + align:start position:0% +above so two are up in energy by three F +and so what do that + + align:start position:0% +and so what do that + + + align:start position:0% +and so what do that +equal zero + + align:start position:0% + + + + align:start position:0% + +and over here then you have five that + + align:start position:0% +and over here then you have five that + + + align:start position:0% +and over here then you have five that +are down in + + align:start position:0% +are down in + + + align:start position:0% +are down in +energy so you'd have minus 10 fths the + + align:start position:0% +energy so you'd have minus 10 fths the + + + align:start position:0% +energy so you'd have minus 10 fths the +octahedral crystal field splitting + + align:start position:0% +octahedral crystal field splitting + + + align:start position:0% +octahedral crystal field splitting +energy and sometimes in some books it + + align:start position:0% +energy and sometimes in some books it + + + align:start position:0% +energy and sometimes in some books it +also includes there is some energy to + + align:start position:0% +also includes there is some energy to + + + align:start position:0% +also includes there is some energy to +associated with pairing so occasionally + + align:start position:0% +associated with pairing so occasionally + + + align:start position:0% +associated with pairing so occasionally +you'll see this written as 2 PE + + align:start position:0% +you'll see this written as 2 PE + + + align:start position:0% +you'll see this written as 2 PE +indicating that there are two sets + + align:start position:0% +indicating that there are two sets + + + align:start position:0% +indicating that there are two sets +um with paired + + align:start position:0% + + + + align:start position:0% + +electrons so there's some energy + + align:start position:0% +electrons so there's some energy + + + align:start position:0% +electrons so there's some energy +associated with that so it's not as + + align:start position:0% +associated with that so it's not as + + + align:start position:0% +associated with that so it's not as +fantastic a situation as it looks like + + align:start position:0% +fantastic a situation as it looks like + + + align:start position:0% +fantastic a situation as it looks like +that there's lots of stabilization where + + align:start position:0% +that there's lots of stabilization where + + + align:start position:0% +that there's lots of stabilization where +the other has a zero stabilization um + + align:start position:0% +the other has a zero stabilization um + + + align:start position:0% +the other has a zero stabilization um +zero destabilization it's uh just about + + align:start position:0% +zero destabilization it's uh just about + + + align:start position:0% +zero destabilization it's uh just about +the same but there is some energy + + align:start position:0% +the same but there is some energy + + + align:start position:0% +the same but there is some energy +associated with this so sometimes you'll + + align:start position:0% +associated with this so sometimes you'll + + + align:start position:0% +associated with this so sometimes you'll +see that you only need to indicate that + + align:start position:0% +see that you only need to indicate that + + + align:start position:0% +see that you only need to indicate that +if it's asked for and I think your book + + align:start position:0% +if it's asked for and I think your book + + + align:start position:0% +if it's asked for and I think your book +doesn't ask ask for it but just so + + align:start position:0% +doesn't ask ask for it but just so + + + align:start position:0% +doesn't ask ask for it but just so +you're aware all right so that's kind of + + align:start position:0% +you're aware all right so that's kind of + + + align:start position:0% +you're aware all right so that's kind of +a review we talked about these things on + + align:start position:0% +a review we talked about these things on + + + align:start position:0% +a review we talked about these things on +Monday on last Monday but I just wanted + + align:start position:0% +Monday on last Monday but I just wanted + + + align:start position:0% +Monday on last Monday but I just wanted +to go through it again because now you + + align:start position:0% +to go through it again because now you + + + align:start position:0% +to go through it again because now you +need to see how this relates to + + align:start position:0% + + + + align:start position:0% + +Colors okay so we have to introduce um + + align:start position:0% +Colors okay so we have to introduce um + + + align:start position:0% +Colors okay so we have to introduce um +this this idea that uh the relative + + align:start position:0% +this this idea that uh the relative + + + align:start position:0% +this this idea that uh the relative +ability of certain common lians to split + + align:start position:0% +ability of certain common lians to split + + + align:start position:0% +ability of certain common lians to split +the D orbital level is what's meant by + + align:start position:0% +the D orbital level is what's meant by + + + align:start position:0% +the D orbital level is what's meant by +this uh spect chemical Series so which + + align:start position:0% +this uh spect chemical Series so which + + + align:start position:0% +this uh spect chemical Series so which +lians there are in one case water and + + align:start position:0% +lians there are in one case water and + + + align:start position:0% +lians there are in one case water and +cyanide causes a difference and a strong + + align:start position:0% +cyanide causes a difference and a strong + + + align:start position:0% +cyanide causes a difference and a strong +field Lian and we talked about this a + + align:start position:0% +field Lian and we talked about this a + + + align:start position:0% +field Lian and we talked about this a +bit on Monday last Monday as well + + align:start position:0% +bit on Monday last Monday as well + + + align:start position:0% +bit on Monday last Monday as well +produces large energy separation so over + + align:start position:0% +produces large energy separation so over + + + align:start position:0% +produces large energy separation so over +here we have a large energy so this + + align:start position:0% +here we have a large energy so this + + + align:start position:0% +here we have a large energy so this +would be a strong a strong field over + + align:start position:0% +would be a strong a strong field over + + + align:start position:0% +would be a strong a strong field over +here so it's strong it splits those D + + align:start position:0% +here so it's strong it splits those D + + + align:start position:0% +here so it's strong it splits those D +orbitals a lot and and a weak field Lian + + align:start position:0% +orbitals a lot and and a weak field Lian + + + align:start position:0% +orbitals a lot and and a weak field Lian +produces a small separation it's pretty + + align:start position:0% +produces a small separation it's pretty + + + align:start position:0% +produces a small separation it's pretty +weak it can't really split those D + + align:start position:0% +weak it can't really split those D + + + align:start position:0% +weak it can't really split those D +orbitals very much it's weak so this + + align:start position:0% +orbitals very much it's weak so this + + + align:start position:0% +orbitals very much it's weak so this +would be a weak field case over here so + + align:start position:0% +would be a weak field case over here so + + + align:start position:0% +would be a weak field case over here so +there's not much splitting between the D + + align:start position:0% +there's not much splitting between the D + + + align:start position:0% +there's not much splitting between the D +orbitals so here are some various lians + + align:start position:0% +orbitals so here are some various lians + + + align:start position:0% +orbitals so here are some various lians +and how they fall into this series and + + align:start position:0% +and how they fall into this series and + + + align:start position:0% +and how they fall into this series and +you'll just you need to know this for + + align:start position:0% +you'll just you need to know this for + + + align:start position:0% +you'll just you need to know this for +the test only these uh sets of lians so + + align:start position:0% +the test only these uh sets of lians so + + + align:start position:0% +the test only these uh sets of lians so +there are three in sort of weak field + + align:start position:0% +there are three in sort of weak field + + + align:start position:0% +there are three in sort of weak field +category three in the intermediate + + align:start position:0% +category three in the intermediate + + + align:start position:0% +category three in the intermediate +category and three in the strong field + + align:start position:0% +category and three in the strong field + + + align:start position:0% +category and three in the strong field +category so when it's a weak field Lian + + align:start position:0% +category so when it's a weak field Lian + + + align:start position:0% +category so when it's a weak field Lian +you're going to have the small splitting + + align:start position:0% +you're going to have the small splitting + + + align:start position:0% +you're going to have the small splitting +as shown here and therefore you'll have + + align:start position:0% +as shown here and therefore you'll have + + + align:start position:0% +as shown here and therefore you'll have +a high spin system where you have the + + align:start position:0% +a high spin system where you have the + + + align:start position:0% +a high spin system where you have the +maximum number of unpaired electrons if + + align:start position:0% +maximum number of unpaired electrons if + + + align:start position:0% +maximum number of unpaired electrons if +you have a strong field you have a large + + align:start position:0% +you have a strong field you have a large + + + align:start position:0% +you have a strong field you have a large +splitting and then you're going to have + + align:start position:0% +splitting and then you're going to have + + + align:start position:0% +splitting and then you're going to have +a low spin system where you have the + + align:start position:0% +a low spin system where you have the + + + align:start position:0% +a low spin system where you have the +minimum number of unpaired + + align:start position:0% + + + + align:start position:0% + +electrons so in the example that we just + + align:start position:0% +electrons so in the example that we just + + + align:start position:0% +electrons so in the example that we just +had we had this is high spin so it's + + align:start position:0% +had we had this is high spin so it's + + + align:start position:0% +had we had this is high spin so it's +actually kind of an intermediate but it + + align:start position:0% +actually kind of an intermediate but it + + + align:start position:0% +actually kind of an intermediate but it +was determined to be high spin + + align:start position:0% +was determined to be high spin + + + align:start position:0% +was determined to be high spin +experimentally the intermediate ones are + + align:start position:0% +experimentally the intermediate ones are + + + align:start position:0% +experimentally the intermediate ones are +a little harder to predict uh these will + + align:start position:0% +a little harder to predict uh these will + + + align:start position:0% +a little harder to predict uh these will +be strong field these will be weak field + + align:start position:0% +be strong field these will be weak field + + + align:start position:0% +be strong field these will be weak field +these are harder to predict uh cyanide + + align:start position:0% +these are harder to predict uh cyanide + + + align:start position:0% +these are harder to predict uh cyanide +according to this list is the strongest + + align:start position:0% +according to this list is the strongest + + + align:start position:0% +according to this list is the strongest +field Lian so so uh that makes that + + align:start position:0% +field Lian so so uh that makes that + + + align:start position:0% +field Lian so so uh that makes that +makes sense that that was then a low + + align:start position:0% +makes sense that that was then a low + + + align:start position:0% +makes sense that that was then a low +spin uh + + align:start position:0% + + + + align:start position:0% + +system so + + align:start position:0% + + + + align:start position:0% + +colors so colors are going to depend on + + align:start position:0% +colors so colors are going to depend on + + + align:start position:0% +colors so colors are going to depend on +uh on what photons are absorbed and the + + align:start position:0% +uh on what photons are absorbed and the + + + align:start position:0% +uh on what photons are absorbed and the +energy level it takes to get to that + + align:start position:0% +energy level it takes to get to that + + + align:start position:0% +energy level it takes to get to that +excited high energy state so here it's a + + align:start position:0% +excited high energy state so here it's a + + + align:start position:0% +excited high energy state so here it's a +very small difference here it's a big + + align:start position:0% +very small difference here it's a big + + + align:start position:0% +very small difference here it's a big +difference so you would need to absorb + + align:start position:0% +difference so you would need to absorb + + + align:start position:0% +difference so you would need to absorb +ABB um differently and then also + + align:start position:0% +ABB um differently and then also + + + align:start position:0% +ABB um differently and then also +transmit differently to excite those + + align:start position:0% +transmit differently to excite those + + + align:start position:0% +transmit differently to excite those +electrons and that's going to give rise + + align:start position:0% +electrons and that's going to give rise + + + align:start position:0% +electrons and that's going to give rise +to the different colors so let's just + + align:start position:0% +to the different colors so let's just + + + align:start position:0% +to the different colors so let's just +take a look at this so now we're + + align:start position:0% +take a look at this so now we're + + + align:start position:0% +take a look at this so now we're +reviewing back to uh the first half of + + align:start position:0% +reviewing back to uh the first half of + + + align:start position:0% +reviewing back to uh the first half of +the semester where you saw this so we + + align:start position:0% +the semester where you saw this so we + + + align:start position:0% +the semester where you saw this so we +have uh the energy of the absorbed light + + align:start position:0% +have uh the energy of the absorbed light + + + align:start position:0% +have uh the energy of the absorbed light +is equal to Plank's constant times the + + align:start position:0% +is equal to Plank's constant times the + + + align:start position:0% +is equal to Plank's constant times the +frequency and so we're back here again + + align:start position:0% +frequency and so we're back here again + + + align:start position:0% +frequency and so we're back here again +we're talking about splitting energies + + align:start position:0% +we're talking about splitting energies + + + align:start position:0% +we're talking about splitting energies +between the D orbitals amount of energy + + align:start position:0% +between the D orbitals amount of energy + + + align:start position:0% +between the D orbitals amount of energy +to excite an electron uh from one set of + + align:start position:0% +to excite an electron uh from one set of + + + align:start position:0% +to excite an electron uh from one set of +orbitals to the higher set of orbitals + + align:start position:0% +orbitals to the higher set of orbitals + + + align:start position:0% +orbitals to the higher set of orbitals +so we're we're back here but now we're + + align:start position:0% +so we're we're back here but now we're + + + align:start position:0% +so we're we're back here but now we're +going to have a little bit of a + + align:start position:0% +going to have a little bit of a + + + align:start position:0% +going to have a little bit of a +difference in that we're going to add + + align:start position:0% +difference in that we're going to add + + + align:start position:0% +difference in that we're going to add +another equal sign and say that that + + align:start position:0% +another equal sign and say that that + + + align:start position:0% +another equal sign and say that that +energy then is going to be in this case + + align:start position:0% +energy then is going to be in this case + + + align:start position:0% +energy then is going to be in this case +for the transition metal complexes + + align:start position:0% +for the transition metal complexes + + + align:start position:0% +for the transition metal complexes +octahedral coordination complexes is + + align:start position:0% +octahedral coordination complexes is + + + align:start position:0% +octahedral coordination complexes is +equal to this octahedral Crystal field + + align:start position:0% +equal to this octahedral Crystal field + + + align:start position:0% +equal to this octahedral Crystal field +splitting energy so again we're going to + + align:start position:0% +splitting energy so again we're going to + + + align:start position:0% +splitting energy so again we're going to +be talking about exciting electrons here + + align:start position:0% +be talking about exciting electrons here + + + align:start position:0% +be talking about exciting electrons here +up to here and so that depends then on + + align:start position:0% +up to here and so that depends then on + + + align:start position:0% +up to here and so that depends then on +how what the energy difference is + + align:start position:0% +how what the energy difference is + + + align:start position:0% +how what the energy difference is +between these sets of orbitals so we've + + align:start position:0% +between these sets of orbitals so we've + + + align:start position:0% +between these sets of orbitals so we've +seen this before and now we're just + + align:start position:0% +seen this before and now we're just + + + align:start position:0% +seen this before and now we're just +adding this new term on the other end + + align:start position:0% +adding this new term on the other end + + + align:start position:0% +adding this new term on the other end +the octahedral crystal field splitting + + align:start position:0% +the octahedral crystal field splitting + + + align:start position:0% +the octahedral crystal field splitting +energy all right so this we also saw in + + align:start position:0% +energy all right so this we also saw in + + + align:start position:0% +energy all right so this we also saw in +the first half of the course so if you + + align:start position:0% +the first half of the course so if you + + + align:start position:0% +the first half of the course so if you +have a high frequency of light is + + align:start position:0% +have a high frequency of light is + + + align:start position:0% +have a high frequency of light is +absorbed the wavelength of the absorbed + + align:start position:0% +absorbed the wavelength of the absorbed + + + align:start position:0% +absorbed the wavelength of the absorbed +light is going to be + + align:start position:0% +light is going to be + + + align:start position:0% +light is going to be +short and that's that equation which was + + align:start position:0% +short and that's that equation which was + + + align:start position:0% +short and that's that equation which was +I think these two equations were + + align:start position:0% +I think these two equations were + + + align:start position:0% +I think these two equations were +equations you needed to have memorized + + align:start position:0% +equations you needed to have memorized + + + align:start position:0% +equations you needed to have memorized +they weren't on the equation seed that + + align:start position:0% +they weren't on the equation seed that + + + align:start position:0% +they weren't on the equation seed that +indicates that they're of really + + align:start position:0% +indicates that they're of really + + + align:start position:0% +indicates that they're of really +fundamental + + align:start position:0% + + + + align:start position:0% + +importance and then the color of the + + align:start position:0% +importance and then the color of the + + + align:start position:0% +importance and then the color of the +transmitted light is complementary to + + align:start position:0% +transmitted light is complementary to + + + align:start position:0% +transmitted light is complementary to +the color of the absorbed light so here + + align:start position:0% +the color of the absorbed light so here + + + align:start position:0% +the color of the absorbed light so here +we need to think beyond the first half + + align:start position:0% +we need to think beyond the first half + + + align:start position:0% +we need to think beyond the first half +of this semester back to probably + + align:start position:0% +of this semester back to probably + + + align:start position:0% +of this semester back to probably +kindergarten when did you first learn + + align:start position:0% +kindergarten when did you first learn + + + align:start position:0% +kindergarten when did you first learn +about complimentary + + align:start position:0% +about complimentary + + + align:start position:0% +about complimentary +colors second + + align:start position:0% + + + + align:start position:0% + +grade so I actually was uh talked into + + align:start position:0% +grade so I actually was uh talked into + + + align:start position:0% +grade so I actually was uh talked into +putting something like this on the exam + + align:start position:0% +putting something like this on the exam + + + align:start position:0% +putting something like this on the exam +so that you wouldn't have to have that + + align:start position:0% +so that you wouldn't have to have that + + + align:start position:0% +so that you wouldn't have to have that +material memorized but anyway here are + + align:start position:0% +material memorized but anyway here are + + + align:start position:0% +material memorized but anyway here are +your complimentary + + align:start position:0% +your complimentary + + + align:start position:0% +your complimentary +colors so if you know something about + + align:start position:0% +colors so if you know something about + + + align:start position:0% +colors so if you know something about +the color of the transition complex you + + align:start position:0% +the color of the transition complex you + + + align:start position:0% +the color of the transition complex you +can go back and calculate and estimate + + align:start position:0% +can go back and calculate and estimate + + + align:start position:0% +can go back and calculate and estimate +if you're given actual numbers you can + + align:start position:0% +if you're given actual numbers you can + + + align:start position:0% +if you're given actual numbers you can +calculate what the splitting energy + + align:start position:0% +calculate what the splitting energy + + + align:start position:0% +calculate what the splitting energy +difference was or you can approximate + + align:start position:0% +difference was or you can approximate + + + align:start position:0% +difference was or you can approximate +whether it's going to be small or large + + align:start position:0% +whether it's going to be small or large + + + align:start position:0% +whether it's going to be small or large +depending on the colors that the + + align:start position:0% +depending on the colors that the + + + align:start position:0% +depending on the colors that the +complexes + + align:start position:0% + + + + align:start position:0% + +have so let's let's take a look at uh + + align:start position:0% +have so let's let's take a look at uh + + + align:start position:0% +have so let's let's take a look at uh +some examples here of two different + + align:start position:0% +some examples here of two different + + + align:start position:0% +some examples here of two different +coordination complexes both + + align:start position:0% + + + + align:start position:0% + +octahedral so first we have to figure + + align:start position:0% +octahedral so first we have to figure + + + align:start position:0% +octahedral so first we have to figure +out the oxidation number so again this + + align:start position:0% +out the oxidation number so again this + + + align:start position:0% +out the oxidation number so again this +goes back to the uh the last unit on + + align:start position:0% +goes back to the uh the last unit on + + + align:start position:0% +goes back to the uh the last unit on +oxidation reduction uh we'll have on the + + align:start position:0% +oxidation reduction uh we'll have on the + + + align:start position:0% +oxidation reduction uh we'll have on the +useful for the exam on Wednesday so the + + align:start position:0% +useful for the exam on Wednesday so the + + + align:start position:0% +useful for the exam on Wednesday so the +uh the number here you're going to + + align:start position:0% +uh the number here you're going to + + + align:start position:0% +uh the number here you're going to +have plus three for both of these guys + + align:start position:0% +have plus three for both of these guys + + + align:start position:0% +have plus three for both of these guys +so this is this is zero and that's zero + + align:start position:0% +so this is this is zero and that's zero + + + align:start position:0% +so this is this is zero and that's zero +the overall charge is plus three so + + align:start position:0% +the overall charge is plus three so + + + align:start position:0% +the overall charge is plus three so +chromium has to be+ three in both cases + + align:start position:0% +chromium has to be+ three in both cases + + + align:start position:0% +chromium has to be+ three in both cases +then when we do the Del electron count + + align:start position:0% +then when we do the Del electron count + + + align:start position:0% +then when we do the Del electron count +we have to find chromium on our periodic + + align:start position:0% +we have to find chromium on our periodic + + + align:start position:0% +we have to find chromium on our periodic +table look up uh what group it's in to + + align:start position:0% +table look up uh what group it's in to + + + align:start position:0% +table look up uh what group it's in to +calculate the + + align:start position:0% +calculate the + + + align:start position:0% +calculate the +dcount so we have that here and we have + + align:start position:0% +dcount so we have that here and we have + + + align:start position:0% +dcount so we have that here and we have +a D3 case what does CN stand + + align:start position:0% +a D3 case what does CN stand + + + align:start position:0% +a D3 case what does CN stand +for coordination number and so what's + + align:start position:0% +for coordination number and so what's + + + align:start position:0% +for coordination number and so what's +the coordination number in this + + align:start position:0% +the coordination number in this + + + align:start position:0% +the coordination number in this +case + + align:start position:0% +case + + + align:start position:0% +case +six right so there's six things here six + + align:start position:0% +six right so there's six things here six + + + align:start position:0% +six right so there's six things here six +things coordinated and and that's not to + + align:start position:0% +things coordinated and and that's not to + + + align:start position:0% +things coordinated and and that's not to +be confused with the steric number which + + align:start position:0% +be confused with the steric number which + + + align:start position:0% +be confused with the steric number which +we talked about uh last Wednesday so the + + align:start position:0% +we talked about uh last Wednesday so the + + + align:start position:0% +we talked about uh last Wednesday so the +type of ligan here water was what what + + align:start position:0% +type of ligan here water was what what + + + align:start position:0% +type of ligan here water was what what +type of Lian in terms of weak to strong + + align:start position:0% +type of Lian in terms of weak to strong + + + align:start position:0% +type of Lian in terms of weak to strong +field it was intermediate and over + + align:start position:0% + + + + align:start position:0% + +here is stronger so these guys are + + align:start position:0% +here is stronger so these guys are + + + align:start position:0% +here is stronger so these guys are +actually not that far apart from each + + align:start position:0% +actually not that far apart from each + + + align:start position:0% +actually not that far apart from each +other uh water was sort of intermediate + + align:start position:0% +other uh water was sort of intermediate + + + align:start position:0% +other uh water was sort of intermediate +it is at least weaker than NH3 NH3 was + + align:start position:0% +it is at least weaker than NH3 NH3 was + + + align:start position:0% +it is at least weaker than NH3 NH3 was +in the strong category so it's at least + + align:start position:0% +in the strong category so it's at least + + + align:start position:0% +in the strong category so it's at least +stronger than water they're not that far + + align:start position:0% +stronger than water they're not that far + + + align:start position:0% +stronger than water they're not that far +apart from each other but this one + + align:start position:0% +apart from each other but this one + + + align:start position:0% +apart from each other but this one +should be a stronger field Lian than + + align:start position:0% +should be a stronger field Lian than + + + align:start position:0% +should be a stronger field Lian than +this + + align:start position:0% + + + + align:start position:0% + +one so if we consider a weaker field + + align:start position:0% +one so if we consider a weaker field + + + align:start position:0% +one so if we consider a weaker field +system and a stronger field + + align:start position:0% +system and a stronger field + + + align:start position:0% +system and a stronger field +system is this going to make any + + align:start position:0% +system is this going to make any + + + align:start position:0% +system is this going to make any +difference to how we put in electrons + + align:start position:0% +difference to how we put in electrons + + + align:start position:0% +difference to how we put in electrons +this time + + align:start position:0% +this time + + + align:start position:0% +this time +no it won't because we only have three + + align:start position:0% +no it won't because we only have three + + + align:start position:0% +no it won't because we only have three +so we would put them in the bottom + + align:start position:0% +so we would put them in the bottom + + + align:start position:0% +so we would put them in the bottom +regardless so the issue is when you get + + align:start position:0% +regardless so the issue is when you get + + + align:start position:0% +regardless so the issue is when you get +to the fourth one when you have the + + align:start position:0% +to the fourth one when you have the + + + align:start position:0% +to the fourth one when you have the +fourth electron you have to decide if + + align:start position:0% +fourth electron you have to decide if + + + align:start position:0% +fourth electron you have to decide if +you're going to put it up here or if + + align:start position:0% +you're going to put it up here or if + + + align:start position:0% +you're going to put it up here or if +you're going to pair but there're only + + align:start position:0% +you're going to pair but there're only + + + align:start position:0% +you're going to pair but there're only +three so the diagrams look the + + align:start position:0% +three so the diagrams look the + + + align:start position:0% +three so the diagrams look the +same but even though the diagrams look + + align:start position:0% +same but even though the diagrams look + + + align:start position:0% +same but even though the diagrams look +the same these compounds are going to + + align:start position:0% +the same these compounds are going to + + + align:start position:0% +the same these compounds are going to +have different properties because they + + align:start position:0% +have different properties because they + + + align:start position:0% +have different properties because they +have different splitting energy + + align:start position:0% +have different splitting energy + + + align:start position:0% +have different splitting energy +and so the um amount of energy required + + align:start position:0% +and so the um amount of energy required + + + align:start position:0% +and so the um amount of energy required +to bump an electron up here is going to + + align:start position:0% +to bump an electron up here is going to + + + align:start position:0% +to bump an electron up here is going to +be different than up here and so you'll + + align:start position:0% +be different than up here and so you'll + + + align:start position:0% +be different than up here and so you'll +have different colors as a result so + + align:start position:0% +have different colors as a result so + + + align:start position:0% +have different colors as a result so +let's take a look at + + align:start position:0% +let's take a look at + + + align:start position:0% +let's take a look at +that so again this is intermediate so + + align:start position:0% +that so again this is intermediate so + + + align:start position:0% +that so again this is intermediate so +this is smaller this is stronger it's + + align:start position:0% +this is smaller this is stronger it's + + + align:start position:0% +this is smaller this is stronger it's +larger it doesn't affect how the + + align:start position:0% +larger it doesn't affect how the + + + align:start position:0% +larger it doesn't affect how the +electrons go in but it does affect the + + align:start position:0% +electrons go in but it does affect the + + + align:start position:0% +electrons go in but it does affect the +property of the + + align:start position:0% + + + + align:start position:0% + +compound so let's go through this and + + align:start position:0% +compound so let's go through this and + + + align:start position:0% +compound so let's go through this and +see what what this means so water then + + align:start position:0% +see what what this means so water then + + + align:start position:0% +see what what this means so water then +is weaker it means the splitting energy + + align:start position:0% +is weaker it means the splitting energy + + + align:start position:0% +is weaker it means the splitting energy +is smaller so if the splitting energy is + + align:start position:0% +is smaller so if the splitting energy is + + + align:start position:0% +is smaller so if the splitting energy is +smaller that means you have a lower + + align:start position:0% +smaller that means you have a lower + + + align:start position:0% +smaller that means you have a lower +energy a smaller energy between them and + + align:start position:0% +energy a smaller energy between them and + + + align:start position:0% +energy a smaller energy between them and +a lower frequency that'll be + + align:start position:0% +a lower frequency that'll be + + + align:start position:0% +a lower frequency that'll be +absorbed in this case this is a strong + + align:start position:0% +absorbed in this case this is a strong + + + align:start position:0% +absorbed in this case this is a strong +field Lian so you'll have a larger + + align:start position:0% +field Lian so you'll have a larger + + + align:start position:0% +field Lian so you'll have a larger +energy and a higher frequency that is + + align:start position:0% + + + + align:start position:0% + +absorbed so so over here if we have the + + align:start position:0% +absorbed so so over here if we have the + + + align:start position:0% +absorbed so so over here if we have the +lower frequency absorbed we have a + + align:start position:0% +lower frequency absorbed we have a + + + align:start position:0% +lower frequency absorbed we have a +longer wavelength absorbed for the + + align:start position:0% +longer wavelength absorbed for the + + + align:start position:0% +longer wavelength absorbed for the +stronger field case we have somewhat of + + align:start position:0% +stronger field case we have somewhat of + + + align:start position:0% +stronger field case we have somewhat of +a higher frequency absorbed so we'll + + align:start position:0% +a higher frequency absorbed so we'll + + + align:start position:0% +a higher frequency absorbed so we'll +have somewhat of a shorter wavelength + + align:start position:0% +have somewhat of a shorter wavelength + + + align:start position:0% +have somewhat of a shorter wavelength +absorbed and then the color of the + + align:start position:0% +absorbed and then the color of the + + + align:start position:0% +absorbed and then the color of the +transmitted light is complementary to + + align:start position:0% +transmitted light is complementary to + + + align:start position:0% +transmitted light is complementary to +the color of the absorbed + + align:start position:0% + + + + align:start position:0% + +light so here you're going to have a + + align:start position:0% +light so here you're going to have a + + + align:start position:0% +light so here you're going to have a +transmitted light with a shorter + + align:start position:0% +transmitted light with a shorter + + + align:start position:0% +transmitted light with a shorter +frequency you you had a long you had a + + align:start position:0% +frequency you you had a long you had a + + + align:start position:0% +frequency you you had a long you had a +longer shorter wavelength you had a + + align:start position:0% +longer shorter wavelength you had a + + + align:start position:0% +longer shorter wavelength you had a +longer wavelength absorbed so you'll + + align:start position:0% +longer wavelength absorbed so you'll + + + align:start position:0% +longer wavelength absorbed so you'll +have a shorter wavelength + + align:start position:0% +have a shorter wavelength + + + align:start position:0% +have a shorter wavelength +transmitted and this compound is in fact + + align:start position:0% +transmitted and this compound is in fact + + + align:start position:0% +transmitted and this compound is in fact +Violet over here you're going to have um + + align:start position:0% +Violet over here you're going to have um + + + align:start position:0% +Violet over here you're going to have um +the shorter wavelength absorbed so the + + align:start position:0% +the shorter wavelength absorbed so the + + + align:start position:0% +the shorter wavelength absorbed so the +transmitted light will be complementary + + align:start position:0% +transmitted light will be complementary + + + align:start position:0% +transmitted light will be complementary +to that and will have a longer + + align:start position:0% +to that and will have a longer + + + align:start position:0% +to that and will have a longer +wavelength and this uh compound is in + + align:start position:0% +wavelength and this uh compound is in + + + align:start position:0% +wavelength and this uh compound is in +fact + + align:start position:0% + + + + align:start position:0% + +yellow so if we uh look again at uh the + + align:start position:0% +yellow so if we uh look again at uh the + + + align:start position:0% +yellow so if we uh look again at uh the +colors and um and their + + align:start position:0% +colors and um and their + + + align:start position:0% +colors and um and their +wavelengths this strong this complex + + align:start position:0% +wavelengths this strong this complex + + + align:start position:0% +wavelengths this strong this complex +with a strong field Li is + + align:start position:0% +with a strong field Li is + + + align:start position:0% +with a strong field Li is +yellow and the one with an intermediate + + align:start position:0% +yellow and the one with an intermediate + + + align:start position:0% +yellow and the one with an intermediate +field ligan is violet somewhere down in + + align:start position:0% +field ligan is violet somewhere down in + + + align:start position:0% +field ligan is violet somewhere down in +here so even though water and NH3 are + + align:start position:0% +here so even though water and NH3 are + + + align:start position:0% +here so even though water and NH3 are +close to each other the one that's + + align:start position:0% +close to each other the one that's + + + align:start position:0% +close to each other the one that's +stronger definitely has quite a distinct + + align:start position:0% +stronger definitely has quite a distinct + + + align:start position:0% +stronger definitely has quite a distinct +color from the one that's a bit weaker + + align:start position:0% +color from the one that's a bit weaker + + + align:start position:0% +color from the one that's a bit weaker +and unless you're given numbers you + + align:start position:0% +and unless you're given numbers you + + + align:start position:0% +and unless you're given numbers you +can't predict exactly which color you + + align:start position:0% +can't predict exactly which color you + + + align:start position:0% +can't predict exactly which color you +could just rationalize the relationship + + align:start position:0% +could just rationalize the relationship + + + align:start position:0% +could just rationalize the relationship +so if you said if you were told this is + + align:start position:0% +so if you said if you were told this is + + + align:start position:0% +so if you said if you were told this is +yellow and this is violet tell me why + + align:start position:0% +yellow and this is violet tell me why + + + align:start position:0% +yellow and this is violet tell me why +you would say this is a stronger field + + align:start position:0% +you would say this is a stronger field + + + align:start position:0% +you would say this is a stronger field +liin than this one so that's the kind of + + align:start position:0% +liin than this one so that's the kind of + + + align:start position:0% +liin than this one so that's the kind of +thing you can do but if you're given + + align:start position:0% +thing you can do but if you're given + + + align:start position:0% +thing you can do but if you're given +numbers and on problems and on the final + + align:start position:0% +numbers and on problems and on the final + + + align:start position:0% +numbers and on problems and on the final +you may be given numbers you can + + align:start position:0% +you may be given numbers you can + + + align:start position:0% +you may be given numbers you can +actually come up and calculate back and + + align:start position:0% +actually come up and calculate back and + + + align:start position:0% +actually come up and calculate back and +forth from the splitting energy to the + + align:start position:0% +forth from the splitting energy to the + + + align:start position:0% +forth from the splitting energy to the +color that you predict from a color back + + align:start position:0% +color that you predict from a color back + + + align:start position:0% +color that you predict from a color back +to the splitting energy + + align:start position:0% + + + + align:start position:0% + +so what things would be + + align:start position:0% +so what things would be + + + align:start position:0% +so what things would be +colorless which kind of coordination + + align:start position:0% +colorless which kind of coordination + + + align:start position:0% +colorless which kind of coordination +complexes will be + + align:start position:0% +complexes will be + + + align:start position:0% +complexes will be +colorless and why would it be + + align:start position:0% + + + + align:start position:0% + +colorless this is where things written + + align:start position:0% +colorless this is where things written + + + align:start position:0% +colorless this is where things written +in your hand bout can be read back to + + align:start position:0% + + + + align:start position:0% + +me unless you know but it's good to + + align:start position:0% +me unless you know but it's good to + + + align:start position:0% +me unless you know but it's good to +think about it a little bit + + align:start position:0% + + + + align:start position:0% + +okay so if you filled up all your D + + align:start position:0% +okay so if you filled up all your D + + + align:start position:0% +okay so if you filled up all your D +orbitals and there's no room for things + + align:start position:0% +orbitals and there's no room for things + + + align:start position:0% +orbitals and there's no room for things +to move around when it's not possible to + + align:start position:0% +to move around when it's not possible to + + + align:start position:0% +to move around when it's not possible to +have a d Tod transition so you filled up + + align:start position:0% +have a d Tod transition so you filled up + + + align:start position:0% +have a d Tod transition so you filled up +everything so you're not going to be + + align:start position:0% +everything so you're not going to be + + + align:start position:0% +everything so you're not going to be +able to do this transition from one set + + align:start position:0% +able to do this transition from one set + + + align:start position:0% +able to do this transition from one set +of D orbitals to another one then uh you + + align:start position:0% +of D orbitals to another one then uh you + + + align:start position:0% +of D orbitals to another one then uh you +have colorless so here are some examples + + align:start position:0% +have colorless so here are some examples + + + align:start position:0% +have colorless so here are some examples +of things that will be colorless and + + align:start position:0% +of things that will be colorless and + + + align:start position:0% +of things that will be colorless and +let's just uh prove that that would be + + align:start position:0% +let's just uh prove that that would be + + + align:start position:0% +let's just uh prove that that would be +true that those are in fact filled so we + + align:start position:0% +true that those are in fact filled so we + + + align:start position:0% +true that those are in fact filled so we +have zinc and cadmium so if we look uh + + align:start position:0% +have zinc and cadmium so if we look uh + + + align:start position:0% +have zinc and cadmium so if we look uh +zinc and cadum are in group + + align:start position:0% +zinc and cadum are in group + + + align:start position:0% +zinc and cadum are in group +12 so 12 minus 2 they're both an oxida + + align:start position:0% +12 so 12 minus 2 they're both an oxida + + + align:start position:0% +12 so 12 minus 2 they're both an oxida +have oxidation numbers of plus two so 12 + + align:start position:0% +have oxidation numbers of plus two so 12 + + + align:start position:0% +have oxidation numbers of plus two so 12 +U minus 2 is 10 you have a d10 system + + align:start position:0% +U minus 2 is 10 you have a d10 system + + + align:start position:0% +U minus 2 is 10 you have a d10 system +this one's also going to be a d10 system + + align:start position:0% +this one's also going to be a d10 system + + + align:start position:0% +this one's also going to be a d10 system +so you're going to have all 10 electrons + + align:start position:0% +so you're going to have all 10 electrons + + + align:start position:0% +so you're going to have all 10 electrons +already in and so you're not going to + + align:start position:0% +already in and so you're not going to + + + align:start position:0% +already in and so you're not going to +have these Transitions and so these in + + align:start position:0% +have these Transitions and so these in + + + align:start position:0% +have these Transitions and so these in +fact are are colorless zinc is is a + + align:start position:0% +fact are are colorless zinc is is a + + + align:start position:0% +fact are are colorless zinc is is a +really important U metal in biology and + + align:start position:0% +really important U metal in biology and + + + align:start position:0% +really important U metal in biology and +it plays structural roles it can play + + align:start position:0% +it plays structural roles it can play + + + align:start position:0% +it plays structural roles it can play +catalytic roles it's a very important + + align:start position:0% +catalytic roles it's a very important + + + align:start position:0% +catalytic roles it's a very important +metal and often when biochemists are + + align:start position:0% +metal and often when biochemists are + + + align:start position:0% +metal and often when biochemists are +trying to uh figure out how a protein + + align:start position:0% +trying to uh figure out how a protein + + + align:start position:0% +trying to uh figure out how a protein +Works they won't realize it's a zinc + + align:start position:0% +Works they won't realize it's a zinc + + + align:start position:0% +Works they won't realize it's a zinc +containing enzyme because the protein + + align:start position:0% +containing enzyme because the protein + + + align:start position:0% +containing enzyme because the protein +won't have any color in contrast there + + align:start position:0% +won't have any color in contrast there + + + align:start position:0% +won't have any color in contrast there +are um proteins and co-actors and metals + + align:start position:0% +are um proteins and co-actors and metals + + + align:start position:0% +are um proteins and co-actors and metals +that have a lot of color and uh then you + + align:start position:0% +that have a lot of color and uh then you + + + align:start position:0% +that have a lot of color and uh then you +can actually as you're purifying the + + align:start position:0% +can actually as you're purifying the + + + align:start position:0% +can actually as you're purifying the +enzyme it'll have this bright orange or + + align:start position:0% +enzyme it'll have this bright orange or + + + align:start position:0% +enzyme it'll have this bright orange or +red uh color and you realize it has some + + align:start position:0% +red uh color and you realize it has some + + + align:start position:0% +red uh color and you realize it has some +metal co-actor in it right from right + + align:start position:0% +metal co-actor in it right from right + + + align:start position:0% +metal co-actor in it right from right +from the very + + align:start position:0% +from the very + + + align:start position:0% +from the very +beginning okay so just to go through + + align:start position:0% +beginning okay so just to go through + + + align:start position:0% +beginning okay so just to go through +then and sort of summarize this whole + + align:start position:0% +then and sort of summarize this whole + + + align:start position:0% +then and sort of summarize this whole +procedure if you're on this end with the + + align:start position:0% +procedure if you're on this end with the + + + align:start position:0% +procedure if you're on this end with the +liggans and the weak field ligans then + + align:start position:0% +liggans and the weak field ligans then + + + align:start position:0% +liggans and the weak field ligans then +you're going to have a small splitting + + align:start position:0% +you're going to have a small splitting + + + align:start position:0% +you're going to have a small splitting +weak things can't split much they don't + + align:start position:0% +weak things can't split much they don't + + + align:start position:0% +weak things can't split much they don't +have enough strength to really split + + align:start position:0% +have enough strength to really split + + + align:start position:0% +have enough strength to really split +those de orbitals apart you'll have a + + align:start position:0% +those de orbitals apart you'll have a + + + align:start position:0% +those de orbitals apart you'll have a +high spin system in this case maximum + + align:start position:0% +high spin system in this case maximum + + + align:start position:0% +high spin system in this case maximum +number of unpaired + + align:start position:0% +number of unpaired + + + align:start position:0% +number of unpaired +electrons uh in terms of the complexes + + align:start position:0% +electrons uh in terms of the complexes + + + align:start position:0% +electrons uh in terms of the complexes +then they'll absorb low energy photons + + align:start position:0% +then they'll absorb low energy photons + + + align:start position:0% +then they'll absorb low energy photons +low frequency long + + align:start position:0% +low frequency long + + + align:start position:0% +low frequency long +wavelength and then they will transmit + + align:start position:0% +wavelength and then they will transmit + + + align:start position:0% +wavelength and then they will transmit +high frequency or short wavelength so + + align:start position:0% +high frequency or short wavelength so + + + align:start position:0% +high frequency or short wavelength so +they're going to be in this uh violet + + align:start position:0% +they're going to be in this uh violet + + + align:start position:0% +they're going to be in this uh violet +blue green end of the Spectra and let me + + align:start position:0% +blue green end of the Spectra and let me + + + align:start position:0% +blue green end of the Spectra and let me +just put uh this one up and actually let + + align:start position:0% +just put uh this one up and actually let + + + align:start position:0% +just put uh this one up and actually let +me just put all these guys up so they'll + + align:start position:0% +me just put all these guys up so they'll + + + align:start position:0% +me just put all these guys up so they'll +be on this end of the Spectra again you + + align:start position:0% +be on this end of the Spectra again you + + + align:start position:0% +be on this end of the Spectra again you +have it's all based on these two + + align:start position:0% +have it's all based on these two + + + align:start position:0% +have it's all based on these two +equations so if you have a small + + align:start position:0% +equations so if you have a small + + + align:start position:0% +equations so if you have a small +splitting small energy you're going to + + align:start position:0% +splitting small energy you're going to + + + align:start position:0% +splitting small energy you're going to +have a low frequency and then you'll + + align:start position:0% +have a low frequency and then you'll + + + align:start position:0% +have a low frequency and then you'll +have a long wavelength for absorbed and + + align:start position:0% +have a long wavelength for absorbed and + + + align:start position:0% +have a long wavelength for absorbed and +the complementary for the transmitted if + + align:start position:0% +the complementary for the transmitted if + + + align:start position:0% +the complementary for the transmitted if +you're strong field you'll have a large + + align:start position:0% +you're strong field you'll have a large + + + align:start position:0% +you're strong field you'll have a large +splitting energy it'll be low spin + + align:start position:0% +splitting energy it'll be low spin + + + align:start position:0% +splitting energy it'll be low spin +minimum number of unpaired + + align:start position:0% +minimum number of unpaired + + + align:start position:0% +minimum number of unpaired +electrons and you'll have uh a situation + + align:start position:0% +electrons and you'll have uh a situation + + + align:start position:0% +electrons and you'll have uh a situation +like this you know here you fill them up + + align:start position:0% +like this you know here you fill them up + + + align:start position:0% +like this you know here you fill them up +to maximum extent here they're low spin + + align:start position:0% +to maximum extent here they're low spin + + + align:start position:0% +to maximum extent here they're low spin +maximum paired uh so then you'll have + + align:start position:0% +maximum paired uh so then you'll have + + + align:start position:0% +maximum paired uh so then you'll have +the complimentary if you have short + + align:start position:0% +the complimentary if you have short + + + align:start position:0% +the complimentary if you have short +wavelength absorbed you'll have long + + align:start position:0% +wavelength absorbed you'll have long + + + align:start position:0% +wavelength absorbed you'll have long +wavelength trans um transmitted and + + align:start position:0% +wavelength trans um transmitted and + + + align:start position:0% +wavelength trans um transmitted and +you'll be on this end of the Spectra so + + align:start position:0% +you'll be on this end of the Spectra so + + + align:start position:0% +you'll be on this end of the Spectra so +you would expect yellow orange or red in + + align:start position:0% +you would expect yellow orange or red in + + + align:start position:0% +you would expect yellow orange or red in +this case so you can make predictions if + + align:start position:0% +this case so you can make predictions if + + + align:start position:0% +this case so you can make predictions if +you know something about the ligan You + + align:start position:0% +you know something about the ligan You + + + align:start position:0% +you know something about the ligan You +can predict the color of the + + align:start position:0% +can predict the color of the + + + align:start position:0% +can predict the color of the +coordination complex or at least + + align:start position:0% +coordination complex or at least + + + align:start position:0% +coordination complex or at least +rationalize the color of the + + align:start position:0% +rationalize the color of the + + + align:start position:0% +rationalize the color of the +coordination + + align:start position:0% + + + + align:start position:0% + +complex so um just to show you sort of a + + align:start position:0% +complex so um just to show you sort of a + + + align:start position:0% +complex so um just to show you sort of a +real example these are all octahedral + + align:start position:0% +real example these are all octahedral + + + align:start position:0% +real example these are all octahedral +complexes with Cobalt and you can see + + align:start position:0% +complexes with Cobalt and you can see + + + align:start position:0% +complexes with Cobalt and you can see +the colors are really dramatically + + align:start position:0% +the colors are really dramatically + + + align:start position:0% +the colors are really dramatically +different so depending on the Lian to + + align:start position:0% +different so depending on the Lian to + + + align:start position:0% +different so depending on the Lian to +the Cobalt you can really get this + + align:start position:0% +the Cobalt you can really get this + + + align:start position:0% +the Cobalt you can really get this +beautiful range of colors + + align:start position:0% +beautiful range of colors + + + align:start position:0% +beautiful range of colors +Associated and uh one of the courses + + align:start position:0% +Associated and uh one of the courses + + + align:start position:0% +Associated and uh one of the courses +that's offered during IAP key that Dr + + align:start position:0% +that's offered during IAP key that Dr + + + align:start position:0% +that's offered during IAP key that Dr +shrank teaches you go through and + + align:start position:0% +shrank teaches you go through and + + + align:start position:0% +shrank teaches you go through and +actually do some of these experiments + + align:start position:0% +actually do some of these experiments + + + align:start position:0% +actually do some of these experiments +and see these colors and so it's a + + align:start position:0% +and see these colors and so it's a + + + align:start position:0% +and see these colors and so it's a +little lab component that complements + + align:start position:0% +little lab component that complements + + + align:start position:0% +little lab component that complements +nicely uh this part of the course as + + align:start position:0% +nicely uh this part of the course as + + + align:start position:0% +nicely uh this part of the course as +well as a few other parts of the course + + align:start position:0% +well as a few other parts of the course + + + align:start position:0% +well as a few other parts of the course +so those are of um these these + + align:start position:0% +so those are of um these these + + + align:start position:0% +so those are of um these these +coordination complexes and uh Cobalt is + + align:start position:0% +coordination complexes and uh Cobalt is + + + align:start position:0% +coordination complexes and uh Cobalt is +also in a + + align:start position:0% +also in a + + + align:start position:0% +also in a +vitamin can someone tell me what vitamin + + align:start position:0% +vitamin can someone tell me what vitamin + + + align:start position:0% +vitamin can someone tell me what vitamin +Cobalt is in the center + + align:start position:0% + + + + align:start position:0% + +of what's my favorite vitamin yes so + + align:start position:0% +of what's my favorite vitamin yes so + + + align:start position:0% +of what's my favorite vitamin yes so +these are colors of + + align:start position:0% +these are colors of + + + align:start position:0% +these are colors of +B12 so this is protein bound to + + align:start position:0% +B12 so this is protein bound to + + + align:start position:0% +B12 so this is protein bound to +different uh different forms of B12 so + + align:start position:0% +different uh different forms of B12 so + + + align:start position:0% +different uh different forms of B12 so +there's actually different lians to the + + align:start position:0% +there's actually different lians to the + + + align:start position:0% +there's actually different lians to the +Cobalt in these three cases and these + + align:start position:0% +Cobalt in these three cases and these + + + align:start position:0% +Cobalt in these three cases and these +are the actual colors it's really + + align:start position:0% +are the actual colors it's really + + + align:start position:0% +are the actual colors it's really +spectacular the colors of these and + + align:start position:0% +spectacular the colors of these and + + + align:start position:0% +spectacular the colors of these and +these are crystals of the of the + + align:start position:0% +these are crystals of the of the + + + align:start position:0% +these are crystals of the of the +proteins so the colors are really very + + align:start position:0% +proteins so the colors are really very + + + align:start position:0% +proteins so the colors are really very +rich so when you're doing experiments on + + align:start position:0% +rich so when you're doing experiments on + + + align:start position:0% +rich so when you're doing experiments on +a B12 system you know something about + + align:start position:0% +a B12 system you know something about + + + align:start position:0% +a B12 system you know something about +the form of B12 if you've some damage to + + align:start position:0% +the form of B12 if you've some damage to + + + align:start position:0% +the form of B12 if you've some damage to +your B12 uh you know it by actually + + align:start position:0% +your B12 uh you know it by actually + + + align:start position:0% +your B12 uh you know it by actually +looking at uh the color of the molecule + + align:start position:0% +looking at uh the color of the molecule + + + align:start position:0% +looking at uh the color of the molecule +you're working with of the crystals or + + align:start position:0% +you're working with of the crystals or + + + align:start position:0% +you're working with of the crystals or +the protein you're working + + align:start position:0% +the protein you're working + + + align:start position:0% +the protein you're working +with okay so very fast then + + align:start position:0% +with okay so very fast then + + + align:start position:0% +with okay so very fast then +magnetism + + align:start position:0% +magnetism + + + align:start position:0% +magnetism +so uh compounds comp that com um + + align:start position:0% +so uh compounds comp that com um + + + align:start position:0% +so uh compounds comp that com um +compounds that have unpaired electrons + + align:start position:0% +compounds that have unpaired electrons + + + align:start position:0% +compounds that have unpaired electrons +are paramagnetic attracted by a magnetic + + align:start position:0% +are paramagnetic attracted by a magnetic + + + align:start position:0% +are paramagnetic attracted by a magnetic +field and ones where they're pair are + + align:start position:0% +field and ones where they're pair are + + + align:start position:0% +field and ones where they're pair are +diamagnetic so they're repelled by a + + align:start position:0% +diamagnetic so they're repelled by a + + + align:start position:0% +diamagnetic so they're repelled by a +magnetic + + align:start position:0% +magnetic + + + align:start position:0% +magnetic +field so you can figure out something + + align:start position:0% +field so you can figure out something + + + align:start position:0% +field so you can figure out something +about the geometries often of your + + align:start position:0% +about the geometries often of your + + + align:start position:0% +about the geometries often of your +compounds by figuring out whether the + + align:start position:0% +compounds by figuring out whether the + + + align:start position:0% +compounds by figuring out whether the +compound is paramagnetic or diamagnetic + + align:start position:0% +compound is paramagnetic or diamagnetic + + + align:start position:0% +compound is paramagnetic or diamagnetic +all right well how would you do this + + align:start position:0% +all right well how would you do this + + + align:start position:0% +all right well how would you do this +well if for example you had a nickel two + + align:start position:0% +well if for example you had a nickel two + + + align:start position:0% +well if for example you had a nickel two +plus system in an enzyme so you have a + + align:start position:0% +plus system in an enzyme so you have a + + + align:start position:0% +plus system in an enzyme so you have a +d8 center in your enzyme and it's found + + align:start position:0% +d8 center in your enzyme and it's found + + + align:start position:0% +d8 center in your enzyme and it's found +to be + + align:start position:0% +to be + + + align:start position:0% +to be +biomagnetic you could ask the question + + align:start position:0% +biomagnetic you could ask the question + + + align:start position:0% +biomagnetic you could ask the question +can I can I guess then whether it has + + align:start position:0% +can I can I guess then whether it has + + + align:start position:0% +can I can I guess then whether it has +Square planer geometry tetrahedral + + align:start position:0% +Square planer geometry tetrahedral + + + align:start position:0% +Square planer geometry tetrahedral +geometry or octahedral geometry because + + align:start position:0% +geometry or octahedral geometry because + + + align:start position:0% +geometry or octahedral geometry because +it is diamagnetic can I figure out the + + align:start position:0% +it is diamagnetic can I figure out the + + + align:start position:0% +it is diamagnetic can I figure out the +geometry knowing that fact knowing about + + align:start position:0% +geometry knowing that fact knowing about + + + align:start position:0% +geometry knowing that fact knowing about +unpaired or paired electrons in this + + align:start position:0% +unpaired or paired electrons in this + + + align:start position:0% +unpaired or paired electrons in this +case we'd have to have its diamagnetic + + align:start position:0% +case we'd have to have its diamagnetic + + + align:start position:0% +case we'd have to have its diamagnetic +all the electrons have to be + + align:start position:0% +all the electrons have to be + + + align:start position:0% +all the electrons have to be +paired so here are our splitting + + align:start position:0% +paired so here are our splitting + + + align:start position:0% +paired so here are our splitting +diagrams for all three cases let's look + + align:start position:0% +diagrams for all three cases let's look + + + align:start position:0% +diagrams for all three cases let's look +at octahedral again we have to put eight + + align:start position:0% +at octahedral again we have to put eight + + + align:start position:0% +at octahedral again we have to put eight +electrons in here are eight electrons + + align:start position:0% +electrons in here are eight electrons + + + align:start position:0% +electrons in here are eight electrons +does this matter if this was weak field + + align:start position:0% +does this matter if this was weak field + + + align:start position:0% +does this matter if this was weak field +or strong field in this case which which + + align:start position:0% +or strong field in this case which which + + + align:start position:0% +or strong field in this case which which +is it can you + + align:start position:0% + + + + align:start position:0% + +tell same right because you would put in + + align:start position:0% +tell same right because you would put in + + + align:start position:0% +tell same right because you would put in +electrons whether you put them in 1 2 3 + + align:start position:0% +electrons whether you put them in 1 2 3 + + + align:start position:0% +electrons whether you put them in 1 2 3 +four five six 78 or put them in 1 2 3 4 + + align:start position:0% +four five six 78 or put them in 1 2 3 4 + + + align:start position:0% +four five six 78 or put them in 1 2 3 4 +5 6 7 8 it's the same + + align:start position:0% +5 6 7 8 it's the same + + + align:start position:0% +5 6 7 8 it's the same +so this could be either notice we have + + align:start position:0% +so this could be either notice we have + + + align:start position:0% +so this could be either notice we have +unpaired electrons so this cannot be the + + align:start position:0% +unpaired electrons so this cannot be the + + + align:start position:0% +unpaired electrons so this cannot be the +geometry of this unknown Center what + + align:start position:0% +geometry of this unknown Center what + + + align:start position:0% +geometry of this unknown Center what +about Square planer let's put them in + + align:start position:0% +about Square planer let's put them in + + + align:start position:0% +about Square planer let's put them in +starting at the bottom so we'll put them + + align:start position:0% +starting at the bottom so we'll put them + + + align:start position:0% +starting at the bottom so we'll put them +all in keep going just put them all in + + align:start position:0% +all in keep going just put them all in + + + align:start position:0% +all in keep going just put them all in +they're + + align:start position:0% +they're + + + align:start position:0% +they're +eight so it didn't really matter too + + align:start position:0% +eight so it didn't really matter too + + + align:start position:0% +eight so it didn't really matter too +much the order I put them in down here + + align:start position:0% +much the order I put them in down here + + + align:start position:0% +much the order I put them in down here +the important point is I really didn't + + align:start position:0% +the important point is I really didn't + + + align:start position:0% +the important point is I really didn't +want to put any in here until I had to + + align:start position:0% +want to put any in here until I had to + + + align:start position:0% +want to put any in here until I had to +because this one if you recall is really + + align:start position:0% +because this one if you recall is really + + + align:start position:0% +because this one if you recall is really +destabilized compared to the rest all + + align:start position:0% +destabilized compared to the rest all + + + align:start position:0% +destabilized compared to the rest all +right so these are all paired up and + + align:start position:0% +right so these are all paired up and + + + align:start position:0% +right so these are all paired up and +let's look at tetrahedral tetrahedral + + align:start position:0% +let's look at tetrahedral tetrahedral + + + align:start position:0% +let's look at tetrahedral tetrahedral +tends to be what kind of + + align:start position:0% +tends to be what kind of + + + align:start position:0% +tends to be what kind of +spin High spin because the splitting + + align:start position:0% +spin High spin because the splitting + + + align:start position:0% +spin High spin because the splitting +energy is small because you don't have + + align:start position:0% +energy is small because you don't have + + + align:start position:0% +energy is small because you don't have +uh lians pointing directly at the D + + align:start position:0% +uh lians pointing directly at the D + + + align:start position:0% +uh lians pointing directly at the D +orbitals so we can put them in in a high + + align:start position:0% +orbitals so we can put them in in a high + + + align:start position:0% +orbitals so we can put them in in a high +spin fashion until we're + + align:start position:0% +spin fashion until we're + + + align:start position:0% +spin fashion until we're +done and uh that's our system it's going + + align:start position:0% +done and uh that's our system it's going + + + align:start position:0% +done and uh that's our system it's going +to this is small splitting energy + + align:start position:0% +to this is small splitting energy + + + align:start position:0% +to this is small splitting energy +and down here so we have unpaired + + align:start position:0% +and down here so we have unpaired + + + align:start position:0% +and down here so we have unpaired +electrons here so this is paramagnetic + + align:start position:0% +electrons here so this is paramagnetic + + + align:start position:0% +electrons here so this is paramagnetic +this is paramagnetic this is diamagnetic + + align:start position:0% +this is paramagnetic this is diamagnetic + + + align:start position:0% +this is paramagnetic this is diamagnetic +so then you could predict that the + + align:start position:0% +so then you could predict that the + + + align:start position:0% +so then you could predict that the +nickel in the enzyme must be square + + align:start position:0% +nickel in the enzyme must be square + + + align:start position:0% +nickel in the enzyme must be square +planer it can't be this and it can't be + + align:start position:0% +planer it can't be this and it can't be + + + align:start position:0% +planer it can't be this and it can't be +that so it tells you something about the + + align:start position:0% +that so it tells you something about the + + + align:start position:0% +that so it tells you something about the +geometry and I'll tell you that there + + align:start position:0% +geometry and I'll tell you that there + + + align:start position:0% +geometry and I'll tell you that there +are two square planer systems at least + + align:start position:0% +are two square planer systems at least + + + align:start position:0% +are two square planer systems at least +in enzymes of nickel and people + + align:start position:0% +in enzymes of nickel and people + + + align:start position:0% +in enzymes of nickel and people +predicted it using similar kinds of + + align:start position:0% +predicted it using similar kinds of + + + align:start position:0% +predicted it using similar kinds of +techniques to what you just learned + + align:start position:0% +techniques to what you just learned + + + align:start position:0% +techniques to what you just learned +about in freshman chemistry okay good + + align:start position:0% +about in freshman chemistry okay good + + + align:start position:0% +about in freshman chemistry okay good +good luck on the exam on Wednesday \ No newline at end of file diff --git a/LqwvVAtEIx8.txt b/LqwvVAtEIx8.txt new file mode 100644 index 0000000000000000000000000000000000000000..bba069ec4c1b13f0a098cf702bd7feb7bee1f527 --- /dev/null +++ b/LqwvVAtEIx8.txt @@ -0,0 +1,1659 @@ +align:start position:0% + +hello everyone today I'm going to talk + + align:start position:0% +hello everyone today I'm going to talk + + + align:start position:0% +hello everyone today I'm going to talk +to you about crystallographic point + + align:start position:0% +to you about crystallographic point + + + align:start position:0% +to you about crystallographic point +groups and how to visualize them with + + align:start position:0% +groups and how to visualize them with + + + align:start position:0% +groups and how to visualize them with +Mathematica phone books are important in + + align:start position:0% +Mathematica phone books are important in + + + align:start position:0% +Mathematica phone books are important in +crystallography as they enable us to + + align:start position:0% +crystallography as they enable us to + + + align:start position:0% +crystallography as they enable us to +classify crystal symmetries of questions + + align:start position:0% +classify crystal symmetries of questions + + + align:start position:0% +classify crystal symmetries of questions +so what are point groups one group sets + + align:start position:0% +so what are point groups one group sets + + + align:start position:0% +so what are point groups one group sets +of symmetries which are in a variant + + align:start position:0% +of symmetries which are in a variant + + + align:start position:0% +of symmetries which are in a variant +around the center from meaning a prompt + + align:start position:0% +around the center from meaning a prompt + + + align:start position:0% +around the center from meaning a prompt +will not change if it's ended at the + + align:start position:0% +will not change if it's ended at the + + + align:start position:0% +will not change if it's ended at the +center and has all of these symmetries + + align:start position:0% +center and has all of these symmetries + + + align:start position:0% +center and has all of these symmetries +applied through three elements of point + + align:start position:0% +applied through three elements of point + + + align:start position:0% +applied through three elements of point +groups our mirror planes rotation axis + + align:start position:0% +groups our mirror planes rotation axis + + + align:start position:0% +groups our mirror planes rotation axis +and roto infusion Isis and mirror planes + + align:start position:0% +and roto infusion Isis and mirror planes + + + align:start position:0% +and roto infusion Isis and mirror planes +as you can be imagined are just taking + + align:start position:0% +as you can be imagined are just taking + + + align:start position:0% +as you can be imagined are just taking +in and then the image the mirror image + + align:start position:0% +in and then the image the mirror image + + + align:start position:0% +in and then the image the mirror image +of this point will be no symmetry mirror + + align:start position:0% +of this point will be no symmetry mirror + + + align:start position:0% +of this point will be no symmetry mirror +planes can be in three dimension meaning + + align:start position:0% +planes can be in three dimension meaning + + + align:start position:0% +planes can be in three dimension meaning +that they can be perpendicular to X + + align:start position:0% +that they can be perpendicular to X + + + align:start position:0% +that they can be perpendicular to X +perpendicular to Y and perpendicular to + + align:start position:0% +perpendicular to Y and perpendicular to + + + align:start position:0% +perpendicular to Y and perpendicular to +the z axis rotation axes are also found + + align:start position:0% +the z axis rotation axes are also found + + + align:start position:0% +the z axis rotation axes are also found +into three dimensions that they are + + align:start position:0% +into three dimensions that they are + + + align:start position:0% +into three dimensions that they are +rotations around this axis so for + + align:start position:0% +rotations around this axis so for + + + align:start position:0% +rotations around this axis so for +example a two-fold rotation would be + + align:start position:0% +example a two-fold rotation would be + + + align:start position:0% +example a two-fold rotation would be +taking a point and making a rotation of + + align:start position:0% +taking a point and making a rotation of + + + align:start position:0% +taking a point and making a rotation of +half a circle around a certain axis and + + align:start position:0% +half a circle around a certain axis and + + + align:start position:0% +half a circle around a certain axis and +this will be the symmetry 3 for rotation + + align:start position:0% +this will be the symmetry 3 for rotation + + + align:start position:0% +this will be the symmetry 3 for rotation +axis will be 3 atoms which are each + + align:start position:0% +axis will be 3 atoms which are each + + + align:start position:0% +axis will be 3 atoms which are each +rotated from by one third of a circle so + + align:start position:0% +rotated from by one third of a circle so + + + align:start position:0% +rotated from by one third of a circle so +brutal inversion axes are bit more + + align:start position:0% +brutal inversion axes are bit more + + + align:start position:0% +brutal inversion axes are bit more +complicated to visualize there are + + align:start position:0% +complicated to visualize there are + + + align:start position:0% +complicated to visualize there are +basically a rotation followed by what we + + align:start position:0% +basically a rotation followed by what we + + + align:start position:0% +basically a rotation followed by what we +call an inversion so for example me if + + align:start position:0% +call an inversion so for example me if + + + align:start position:0% +call an inversion so for example me if +we take a four-fold roto inversion axis + + align:start position:0% +we take a four-fold roto inversion axis + + + align:start position:0% +we take a four-fold roto inversion axis +we have to take album rotated by 1/4 of + + align:start position:0% +we have to take album rotated by 1/4 of + + + align:start position:0% +we have to take album rotated by 1/4 of +a circle and then invert this point + + align:start position:0% +a circle and then invert this point + + + align:start position:0% +a circle and then invert this point +through the origin + + align:start position:0% +through the origin + + + align:start position:0% +through the origin +so basically inverting would be taking + + align:start position:0% +so basically inverting would be taking + + + align:start position:0% +so basically inverting would be taking +opponent which has the coordinates 1 on + + align:start position:0% +opponent which has the coordinates 1 on + + + align:start position:0% +opponent which has the coordinates 1 on +1 and transforming it into minus 1 minus + + align:start position:0% +1 and transforming it into minus 1 minus + + + align:start position:0% +1 and transforming it into minus 1 minus +1 minus 1 when we come when we mix all + + align:start position:0% +1 minus 1 when we come when we mix all + + + align:start position:0% +1 minus 1 when we come when we mix all +of these elements we get the 32 point + + align:start position:0% +of these elements we get the 32 point + + + align:start position:0% +of these elements we get the 32 point +groups which are in crystal graphene as + + align:start position:0% +groups which are in crystal graphene as + + + align:start position:0% +groups which are in crystal graphene as +you can see in their routine notation + + align:start position:0% +you can see in their routine notation + + + align:start position:0% +you can see in their routine notation +like this so let's talk a bit about the + + align:start position:0% +like this so let's talk a bit about the + + + align:start position:0% +like this so let's talk a bit about the +notation + + align:start position:0% +notation + + + align:start position:0% +notation +and it is fairly simple we take an M if + + align:start position:0% +and it is fairly simple we take an M if + + + align:start position:0% +and it is fairly simple we take an M if +we have a mirror plane two M's if we + + align:start position:0% +we have a mirror plane two M's if we + + + align:start position:0% +we have a mirror plane two M's if we +have two mirror planes Xterra if this + + align:start position:0% +have two mirror planes Xterra if this + + + align:start position:0% +have two mirror planes Xterra if this +mirror plane is perpendicular to an + + align:start position:0% +mirror plane is perpendicular to an + + + align:start position:0% +mirror plane is perpendicular to an +already existing rotation axis then we + + align:start position:0% +already existing rotation axis then we + + + align:start position:0% +already existing rotation axis then we +we noted slash air and a rotation axis + + align:start position:0% +we noted slash air and a rotation axis + + + align:start position:0% +we noted slash air and a rotation axis +is basically just a number which tells + + align:start position:0% +is basically just a number which tells + + + align:start position:0% +is basically just a number which tells +us the number of rotations so three four + + align:start position:0% +us the number of rotations so three four + + + align:start position:0% +us the number of rotations so three four +rotation axis would be three + + align:start position:0% +rotation axis would be three + + + align:start position:0% +rotation axis would be three +you know three rotation around the axis + + align:start position:0% +you know three rotation around the axis + + + align:start position:0% +you know three rotation around the axis +X bar is also antenatal four roto + + align:start position:0% +X bar is also antenatal four roto + + + align:start position:0% +X bar is also antenatal four roto +inversion axis so if we look at example + + align:start position:0% +inversion axis so if we look at example + + + align:start position:0% +inversion axis so if we look at example +examples in a couple of examples we can + + align:start position:0% +examples in a couple of examples we can + + + align:start position:0% +examples in a couple of examples we can +see the first point group which is named + + align:start position:0% +see the first point group which is named + + + align:start position:0% +see the first point group which is named +one which basically has no symmetry so + + align:start position:0% +one which basically has no symmetry so + + + align:start position:0% +one which basically has no symmetry so +we have a point and nothing happens with + + align:start position:0% +we have a point and nothing happens with + + + align:start position:0% +we have a point and nothing happens with +it then we have the two fold rotation + + align:start position:0% +it then we have the two fold rotation + + + align:start position:0% +it then we have the two fold rotation +axis so we take this point rotate it by + + align:start position:0% +axis so we take this point rotate it by + + + align:start position:0% +axis so we take this point rotate it by +half a circle and we get this pumped + + align:start position:0% +half a circle and we get this pumped + + + align:start position:0% +half a circle and we get this pumped +same for the 3/4 rotation axis one two + + align:start position:0% +same for the 3/4 rotation axis one two + + + align:start position:0% +same for the 3/4 rotation axis one two +and three and we're back to the original + + align:start position:0% +and three and we're back to the original + + + align:start position:0% +and three and we're back to the original +position and then we have here the + + align:start position:0% +position and then we have here the + + + align:start position:0% +position and then we have here the +fourfold rotation axis and here the six + + align:start position:0% +fourfold rotation axis and here the six + + + align:start position:0% +fourfold rotation axis and here the six +for rotation missus if we take something + + align:start position:0% +for rotation missus if we take something + + + align:start position:0% +for rotation missus if we take something +which has whenever planes this is mmm so + + align:start position:0% +which has whenever planes this is mmm so + + + align:start position:0% +which has whenever planes this is mmm so +for example we can take the cross which + + align:start position:0% +for example we can take the cross which + + + align:start position:0% +for example we can take the cross which +is the cross symbolizes an atom which is + + align:start position:0% +is the cross symbolizes an atom which is + + + align:start position:0% +is the cross symbolizes an atom which is +above the plane and a circle another + + align:start position:0% +above the plane and a circle another + + + align:start position:0% +above the plane and a circle another +which is below the plane so if we take + + align:start position:0% +which is below the plane so if we take + + + align:start position:0% +which is below the plane so if we take +this point and then say that there is a + + align:start position:0% +this point and then say that there is a + + + align:start position:0% +this point and then say that there is a +mirror plane here then we have of course + + align:start position:0% +mirror plane here then we have of course + + + align:start position:0% +mirror plane here then we have of course +to find a mirror image which is here + + align:start position:0% +to find a mirror image which is here + + + align:start position:0% +to find a mirror image which is here +then if we say it is a mirror plane on + + align:start position:0% +then if we say it is a mirror plane on + + + align:start position:0% +then if we say it is a mirror plane on +this direction then we have to take + + align:start position:0% +this direction then we have to take + + + align:start position:0% +this direction then we have to take +these two atoms and put them here and + + align:start position:0% +these two atoms and put them here and + + + align:start position:0% +these two atoms and put them here and +then we also have a third mirror plane + + align:start position:0% +then we also have a third mirror plane + + + align:start position:0% +then we also have a third mirror plane +which would be perpendicular to the x + + align:start position:0% +which would be perpendicular to the x + + + align:start position:0% +which would be perpendicular to the x +axis so the x axis in these images goes + + align:start position:0% +axis so the x axis in these images goes + + + align:start position:0% +axis so the x axis in these images goes +out of the screen and that's how we end + + align:start position:0% +out of the screen and that's how we end + + + align:start position:0% +out of the screen and that's how we end +up with four atoms on the top and four + + align:start position:0% +up with four atoms on the top and four + + + align:start position:0% +up with four atoms on the top and four +atoms below and then we can combine + + align:start position:0% +atoms below and then we can combine + + + align:start position:0% +atoms below and then we can combine +these with rotation axes so for example + + align:start position:0% +these with rotation axes so for example + + + align:start position:0% +these with rotation axes so for example +this is the two / M so basically we have + + align:start position:0% +this is the two / M so basically we have + + + align:start position:0% +this is the two / M so basically we have +a two for rotation and then we have a + + align:start position:0% +a two for rotation and then we have a + + + align:start position:0% +a two for rotation and then we have a +mirror plane which is perpendicular to + + align:start position:0% +mirror plane which is perpendicular to + + + align:start position:0% +mirror plane which is perpendicular to +the x axis so we get two atoms above and + + align:start position:0% +the x axis so we get two atoms above and + + + align:start position:0% +the x axis so we get two atoms above and +two atoms bill + + align:start position:0% +two atoms bill + + + align:start position:0% +two atoms bill +mm you can also play around with the + + align:start position:0% +mm you can also play around with the + + + align:start position:0% +mm you can also play around with the +rest and see if there if it works but we + + align:start position:0% +rest and see if there if it works but we + + + align:start position:0% +rest and see if there if it works but we +get it gets more and more complicated + + align:start position:0% +get it gets more and more complicated + + + align:start position:0% +get it gets more and more complicated +look to this one which is M power 3 M + + align:start position:0% +look to this one which is M power 3 M + + + align:start position:0% +look to this one which is M power 3 M +which is the most symmetric of these + + align:start position:0% +which is the most symmetric of these + + + align:start position:0% +which is the most symmetric of these +point groups so how do we use point + + align:start position:0% +point groups so how do we use point + + + align:start position:0% +point groups so how do we use point +groups it's basically if we combine the + + align:start position:0% +groups it's basically if we combine the + + + align:start position:0% +groups it's basically if we combine the +32 point groups with the transmission of + + align:start position:0% +32 point groups with the transmission of + + + align:start position:0% +32 point groups with the transmission of +symmetries after 14 bravais lattices and + + align:start position:0% +symmetries after 14 bravais lattices and + + + align:start position:0% +symmetries after 14 bravais lattices and +the light planes of complete screw axes + + align:start position:0% +the light planes of complete screw axes + + + align:start position:0% +the light planes of complete screw axes +which are which are found in an + + align:start position:0% +which are which are found in an + + + align:start position:0% +which are which are found in an +intuitive you start to combine point + + align:start position:0% +intuitive you start to combine point + + + align:start position:0% +intuitive you start to combine point +groups then we end up with the 270 space + + align:start position:0% +groups then we end up with the 270 space + + + align:start position:0% +groups then we end up with the 270 space +group to which all crystals belong and + + align:start position:0% +group to which all crystals belong and + + + align:start position:0% +group to which all crystals belong and +so how do we combine point groups and + + align:start position:0% +so how do we combine point groups and + + + align:start position:0% +so how do we combine point groups and +profit lattices so here is the list of + + align:start position:0% +profit lattices so here is the list of + + + align:start position:0% +profit lattices so here is the list of +the present this is the basically just + + align:start position:0% +the present this is the basically just + + + align:start position:0% +the present this is the basically just +taking a pond and transmitting it around + + align:start position:0% +taking a pond and transmitting it around + + + align:start position:0% +taking a pond and transmitting it around +a look this a cubic lattice tetragonal + + align:start position:0% +a look this a cubic lattice tetragonal + + + align:start position:0% +a look this a cubic lattice tetragonal +lattice exact and on everything the blue + + align:start position:0% +lattice exact and on everything the blue + + + align:start position:0% +lattice exact and on everything the blue +point will be the center of the point + + align:start position:0% +point will be the center of the point + + + align:start position:0% +point will be the center of the point +group and then we just translate this + + align:start position:0% +group and then we just translate this + + + align:start position:0% +group and then we just translate this +mass of atoms which are the signature on + + align:start position:0% +mass of atoms which are the signature on + + + align:start position:0% +mass of atoms which are the signature on +upon hoop and then transmitted around + + align:start position:0% +upon hoop and then transmitted around + + + align:start position:0% +upon hoop and then transmitted around +the lattice so let's look at the code + + align:start position:0% +the lattice so let's look at the code + + + align:start position:0% +the lattice so let's look at the code +and see how we visualize them so this is + + align:start position:0% +and see how we visualize them so this is + + + align:start position:0% +and see how we visualize them so this is +the manipulate which has the function + + align:start position:0% +the manipulate which has the function + + + align:start position:0% +the manipulate which has the function +embedded inside so we start with one + + align:start position:0% +embedded inside so we start with one + + + align:start position:0% +embedded inside so we start with one +atom which is the point group one if we + + align:start position:0% +atom which is the point group one if we + + + align:start position:0% +atom which is the point group one if we +decide to to make a mirror plane for + + align:start position:0% +decide to to make a mirror plane for + + + align:start position:0% +decide to to make a mirror plane for +support perpendicular to X then we end + + align:start position:0% +support perpendicular to X then we end + + + align:start position:0% +support perpendicular to X then we end +up with this this is a trust mode mirror + + align:start position:0% +up with this this is a trust mode mirror + + + align:start position:0% +up with this this is a trust mode mirror +plane which has an same name one then + + align:start position:0% +plane which has an same name one then + + + align:start position:0% +plane which has an same name one then +paint bench then we can have three + + align:start position:0% +paint bench then we can have three + + + align:start position:0% +paint bench then we can have three +mirror planes which would give us a + + align:start position:0% +mirror planes which would give us a + + + align:start position:0% +mirror planes which would give us a +patterns and and this is basically what + + align:start position:0% +patterns and and this is basically what + + + align:start position:0% +patterns and and this is basically what +the code does just taking or the or what + + align:start position:0% +the code does just taking or the or what + + + align:start position:0% +the code does just taking or the or what +will give it so if and so what we can + + align:start position:0% +will give it so if and so what we can + + + align:start position:0% +will give it so if and so what we can +take to to to which you can find is this + + align:start position:0% +take to to to which you can find is this + + + align:start position:0% +take to to to which you can find is this +one here + + align:start position:0% +one here + + + align:start position:0% +one here +two two two gives us this so this is two + + align:start position:0% +two two two gives us this so this is two + + + align:start position:0% +two two two gives us this so this is two +two two rotation axis symmetry two point + + align:start position:0% +two two rotation axis symmetry two point + + + align:start position:0% +two two rotation axis symmetry two point +group here in the function we also have + + align:start position:0% +group here in the function we also have + + + align:start position:0% +group here in the function we also have +the number of atoms which is four and we + + align:start position:0% +the number of atoms which is four and we + + + align:start position:0% +the number of atoms which is four and we +have the name of the point group which + + align:start position:0% +have the name of the point group which + + + align:start position:0% +have the name of the point group which +is a bit experimental because it's not + + align:start position:0% +is a bit experimental because it's not + + + align:start position:0% +is a bit experimental because it's not +easy to generate a name out of under the + + align:start position:0% +easy to generate a name out of under the + + + align:start position:0% +easy to generate a name out of under the +atomic chance and this code can generate + + align:start position:0% +atomic chance and this code can generate + + + align:start position:0% +atomic chance and this code can generate +for example this which is upon coop + + align:start position:0% +for example this which is upon coop + + + align:start position:0% +for example this which is upon coop +which doesn't + + align:start position:0% +which doesn't + + + align:start position:0% +which doesn't +exist six sixes it's just this is the + + align:start position:0% +exist six sixes it's just this is the + + + align:start position:0% +exist six sixes it's just this is the +first version of the code which might be + + align:start position:0% +first version of the code which might be + + + align:start position:0% +first version of the code which might be +improved of course we can also take both + + align:start position:0% +improved of course we can also take both + + + align:start position:0% +improved of course we can also take both +to a diversion axis here so if we try to + + align:start position:0% +to a diversion axis here so if we try to + + + align:start position:0% +to a diversion axis here so if we try to +understand what what's happening with + + align:start position:0% +understand what what's happening with + + + align:start position:0% +understand what what's happening with +this one is we have an atom then we + + align:start position:0% +this one is we have an atom then we + + + align:start position:0% +this one is we have an atom then we +trance + + align:start position:0% +trance + + + align:start position:0% +trance +so we said a wonderful rotation of + + align:start position:0% +so we said a wonderful rotation of + + + align:start position:0% +so we said a wonderful rotation of +rotoinversion axis would be at one for + + align:start position:0% +rotoinversion axis would be at one for + + + align:start position:0% +rotoinversion axis would be at one for +rotation so basically we end up at the + + align:start position:0% +rotation so basically we end up at the + + + align:start position:0% +rotation so basically we end up at the +same point and then we invert it through + + align:start position:0% +same point and then we invert it through + + + align:start position:0% +same point and then we invert it through +the origin and then weak this opposite + + align:start position:0% +the origin and then weak this opposite + + + align:start position:0% +the origin and then weak this opposite +atom as you can see if we get it maybe + + align:start position:0% +atom as you can see if we get it maybe + + + align:start position:0% +atom as you can see if we get it maybe +clearer to see if we have a three rotor + + align:start position:0% +clearer to see if we have a three rotor + + + align:start position:0% +clearer to see if we have a three rotor +in a version access so you can clearly + + align:start position:0% +in a version access so you can clearly + + + align:start position:0% +in a version access so you can clearly +see that at the three for rotation so we + + align:start position:0% +see that at the three for rotation so we + + + align:start position:0% +see that at the three for rotation so we +have three atoms on one side and three + + align:start position:0% +have three atoms on one side and three + + + align:start position:0% +have three atoms on one side and three +atoms on the other side so the atoms + + align:start position:0% +atoms on the other side so the atoms + + + align:start position:0% +atoms on the other side so the atoms +above and three atoms below and then and + + align:start position:0% +above and three atoms below and then and + + + align:start position:0% +above and three atoms below and then and +then we invert them each time so this is + + align:start position:0% +then we invert them each time so this is + + + align:start position:0% +then we invert them each time so this is +the code and now let's look at how it + + align:start position:0% +the code and now let's look at how it + + + align:start position:0% +the code and now let's look at how it +works + + align:start position:0% +works + + + align:start position:0% +works +so it is quite easy what the code does + + align:start position:0% +so it is quite easy what the code does + + + align:start position:0% +so it is quite easy what the code does +is taking inputs and then calculating + + align:start position:0% +is taking inputs and then calculating + + + align:start position:0% +is taking inputs and then calculating +all the matrices of molar + + align:start position:0% +all the matrices of molar + + + align:start position:0% +all the matrices of molar +transformations so the first line here + + align:start position:0% +transformations so the first line here + + + align:start position:0% +transformations so the first line here +would be taking the matrix of the BOK so + + align:start position:0% +would be taking the matrix of the BOK so + + + align:start position:0% +would be taking the matrix of the BOK so +with a function of reflection transform + + align:start position:0% +with a function of reflection transform + + + align:start position:0% +with a function of reflection transform +from Mathematica this line takes the + + align:start position:0% +from Mathematica this line takes the + + + align:start position:0% +from Mathematica this line takes the +rotation axis with the rotation + + align:start position:0% +rotation axis with the rotation + + + align:start position:0% +rotation axis with the rotation +transform function then these lines + + align:start position:0% +transform function then these lines + + + align:start position:0% +transform function then these lines +calculate all the rotation all the + + align:start position:0% +calculate all the rotation all the + + + align:start position:0% +calculate all the rotation all the +transformation matrices from each photo + + align:start position:0% +transformation matrices from each photo + + + align:start position:0% +transformation matrices from each photo +inversion X's in the as you can see is a + + align:start position:0% +inversion X's in the as you can see is a + + + align:start position:0% +inversion X's in the as you can see is a +bit more complicated to come up with and + + align:start position:0% +bit more complicated to come up with and + + + align:start position:0% +bit more complicated to come up with and +then taking all of these matrices which + + align:start position:0% +then taking all of these matrices which + + + align:start position:0% +then taking all of these matrices which +are found in the lines of matrices amira + + align:start position:0% +are found in the lines of matrices amira + + + align:start position:0% +are found in the lines of matrices amira +matrices reports and matrices in 402 + + align:start position:0% +matrices reports and matrices in 402 + + + align:start position:0% +matrices reports and matrices in 402 +inversion we do the outer product of all + + align:start position:0% +inversion we do the outer product of all + + + align:start position:0% +inversion we do the outer product of all +of these matrices we get every possible + + align:start position:0% +of these matrices we get every possible + + + align:start position:0% +of these matrices we get every possible +combination of every possible symmetry + + align:start position:0% +combination of every possible symmetry + + + align:start position:0% +combination of every possible symmetry +so we can have all the put on the + + align:start position:0% +so we can have all the put on the + + + align:start position:0% +so we can have all the put on the +symmetry positions and then we are + + align:start position:0% +symmetry positions and then we are + + + align:start position:0% +symmetry positions and then we are +applying that to our initial position + + align:start position:0% +applying that to our initial position + + + align:start position:0% +applying that to our initial position +and we get all the symmetry positions + + align:start position:0% +and we get all the symmetry positions + + + align:start position:0% +and we get all the symmetry positions +then we delete duplicates of symmetry + + align:start position:0% +then we delete duplicates of symmetry + + + align:start position:0% +then we delete duplicates of symmetry +position we make sphere out of it and + + align:start position:0% +position we make sphere out of it and + + + align:start position:0% +position we make sphere out of it and +then we + + align:start position:0% +then we + + + align:start position:0% +then we +we display everything in a graphics 3d + + align:start position:0% +we display everything in a graphics 3d + + + align:start position:0% +we display everything in a graphics 3d +this bit here is to generate the name of + + align:start position:0% +this bit here is to generate the name of + + + align:start position:0% +this bit here is to generate the name of +the point group as I said experimental + + align:start position:0% +the point group as I said experimental + + + align:start position:0% +the point group as I said experimental +and this bit here is to calculate the + + align:start position:0% +and this bit here is to calculate the + + + align:start position:0% +and this bit here is to calculate the +number of atoms we have so this is + + align:start position:0% +number of atoms we have so this is + + + align:start position:0% +number of atoms we have so this is +basically the function which is not that + + align:start position:0% +basically the function which is not that + + + align:start position:0% +basically the function which is not that +complicated as I said and here is the + + align:start position:0% +complicated as I said and here is the + + + align:start position:0% +complicated as I said and here is the +result as we can have as you can see we + + align:start position:0% +result as we can have as you can see we + + + align:start position:0% +result as we can have as you can see we +can start combining everything and + + align:start position:0% +can start combining everything and + + + align:start position:0% +can start combining everything and +having your toolbar am to borrow to + + align:start position:0% +having your toolbar am to borrow to + + + align:start position:0% +having your toolbar am to borrow to +param and just play with it this is a + + align:start position:0% +param and just play with it this is a + + + align:start position:0% +param and just play with it this is a +this is why it is clever this code is + + align:start position:0% +this is why it is clever this code is + + + align:start position:0% +this is why it is clever this code is +quite because we can actually visualize + + align:start position:0% +quite because we can actually visualize + + + align:start position:0% +quite because we can actually visualize +pollen groups in 3d instead of seeing + + align:start position:0% +pollen groups in 3d instead of seeing + + + align:start position:0% +pollen groups in 3d instead of seeing +them as these 2d representations so I + + align:start position:0% +them as these 2d representations so I + + + align:start position:0% +them as these 2d representations so I +hope you had a fun time and thank you + + align:start position:0% +hope you had a fun time and thank you + + + align:start position:0% +hope you had a fun time and thank you +for your attention \ No newline at end of file diff --git a/LxDmWdOwIA8.txt b/LxDmWdOwIA8.txt new file mode 100644 index 0000000000000000000000000000000000000000..ec2a0a84131969948c5f836f83d9bbd40af99e6b --- /dev/null +++ b/LxDmWdOwIA8.txt @@ -0,0 +1,1979 @@ +align:start position:0% + +welcome you are about to do something + + align:start position:0% +welcome you are about to do something + + + align:start position:0% +welcome you are about to do something +very special which is to negotiate the + + align:start position:0% +very special which is to negotiate the + + + align:start position:0% +very special which is to negotiate the +future of work this video is designed to + + align:start position:0% +future of work this video is designed to + + + align:start position:0% +future of work this video is designed to +help you know what you need to know to + + align:start position:0% +help you know what you need to know to + + + align:start position:0% +help you know what you need to know to +nav naate the software and the tools and + + align:start position:0% +nav naate the software and the tools and + + + align:start position:0% +nav naate the software and the tools and +methods to help you be successful in + + align:start position:0% +methods to help you be successful in + + + align:start position:0% +methods to help you be successful in +this + + align:start position:0% +this + + + align:start position:0% +this +process what you see on the screen are a + + align:start position:0% +process what you see on the screen are a + + + align:start position:0% +process what you see on the screen are a +series of slides uh we'll spend more + + align:start position:0% +series of slides uh we'll spend more + + + align:start position:0% +series of slides uh we'll spend more +time with some less with others but all + + align:start position:0% +time with some less with others but all + + + align:start position:0% +time with some less with others but all +of them will be available to you on the + + align:start position:0% +of them will be available to you on the + + + align:start position:0% +of them will be available to you on the +course website here's what you need to + + align:start position:0% +course website here's what you need to + + + align:start position:0% +course website here's what you need to +know at the + + align:start position:0% +know at the + + + align:start position:0% +know at the +beginning once you agree to be part of + + align:start position:0% +beginning once you agree to be part of + + + align:start position:0% +beginning once you agree to be part of +this negotiations we want you to sign up + + align:start position:0% +this negotiations we want you to sign up + + + align:start position:0% +this negotiations we want you to sign up +and we want you to commit because in the + + align:start position:0% +and we want you to commit because in the + + + align:start position:0% +and we want you to commit because in the +negotiations there will be yourself and + + align:start position:0% +negotiations there will be yourself and + + + align:start position:0% +negotiations there will be yourself and +three or four other people in + + align:start position:0% +three or four other people in + + + align:start position:0% +three or four other people in +appropriate roles and they'll all be + + align:start position:0% +appropriate roles and they'll all be + + + align:start position:0% +appropriate roles and they'll all be +depending on you to stay through uh to + + align:start position:0% +depending on you to stay through uh to + + + align:start position:0% +depending on you to stay through uh to +agreement and frankly that's how you'll + + align:start position:0% +agreement and frankly that's how you'll + + + align:start position:0% +agreement and frankly that's how you'll +all learn what are the roles the roles + + align:start position:0% +all learn what are the roles the roles + + + align:start position:0% +all learn what are the roles the roles +in the negotiation match key + + align:start position:0% +in the negotiation match key + + + align:start position:0% +in the negotiation match key +stakeholders in society Labor Management + + align:start position:0% +stakeholders in society Labor Management + + + align:start position:0% +stakeholders in society Labor Management +government and education and essentially + + align:start position:0% +government and education and essentially + + + align:start position:0% +government and education and essentially +each of you will be taking on one of + + align:start position:0% +each of you will be taking on one of + + + align:start position:0% +each of you will be taking on one of +these roles they'll be assigned through + + align:start position:0% +these roles they'll be assigned through + + + align:start position:0% +these roles they'll be assigned through +the course + + align:start position:0% +the course + + + align:start position:0% +the course +platform and that will tell you who + + align:start position:0% +platform and that will tell you who + + + align:start position:0% +platform and that will tell you who +you're going to represent in figuring + + align:start position:0% +you're going to represent in figuring + + + align:start position:0% +you're going to represent in figuring +out the future of work + + align:start position:0% +out the future of work + + + align:start position:0% +out the future of work +now once you're assigned to your role + + align:start position:0% +now once you're assigned to your role + + + align:start position:0% +now once you're assigned to your role +you'll come to the website uh platform + + align:start position:0% +you'll come to the website uh platform + + + align:start position:0% +you'll come to the website uh platform +for this negotiation that's what you see + + align:start position:0% +for this negotiation that's what you see + + + align:start position:0% +for this negotiation that's what you see +on the screen here it again reiterates + + align:start position:0% +on the screen here it again reiterates + + + align:start position:0% +on the screen here it again reiterates +what are the different roles in the + + align:start position:0% +what are the different roles in the + + + align:start position:0% +what are the different roles in the +exercise and gives you some background + + align:start position:0% +exercise and gives you some background + + + align:start position:0% +exercise and gives you some background +about the assignment and then for all + + align:start position:0% +about the assignment and then for all + + + align:start position:0% +about the assignment and then for all +four of the roles there's two here and + + align:start position:0% +four of the roles there's two here and + + + align:start position:0% +four of the roles there's two here and +two more uh you'll see some ex + + align:start position:0% +two more uh you'll see some ex + + + align:start position:0% +two more uh you'll see some ex +additional information to help you know + + align:start position:0% +additional information to help you know + + + align:start position:0% +additional information to help you know +what you need to know to be effective in + + align:start position:0% +what you need to know to be effective in + + + align:start position:0% +what you need to know to be effective in +your role you'll see there's a next + + align:start position:0% +your role you'll see there's a next + + + align:start position:0% +your role you'll see there's a next +button and I just checked it that will + + align:start position:0% +button and I just checked it that will + + + align:start position:0% +button and I just checked it that will +move you on to the next screen which is + + align:start position:0% +move you on to the next screen which is + + + align:start position:0% +move you on to the next screen which is +where you start to fill out some of the + + align:start position:0% +where you start to fill out some of the + + + align:start position:0% +where you start to fill out some of the +key information we need there's + + align:start position:0% +key information we need there's + + + align:start position:0% +key information we need there's +different universities that are + + align:start position:0% +different universities that are + + + align:start position:0% +different universities that are +participating in this check which one + + align:start position:0% +participating in this check which one + + + align:start position:0% +participating in this check which one +you're coming from you will be assigned + + align:start position:0% +you're coming from you will be assigned + + + align:start position:0% +you're coming from you will be assigned +a group number which you want to assign + + align:start position:0% +a group number which you want to assign + + + align:start position:0% +a group number which you want to assign +and then there's other demographic + + align:start position:0% +and then there's other demographic + + + align:start position:0% +and then there's other demographic +information that you'll fill out uh on + + align:start position:0% +information that you'll fill out uh on + + + align:start position:0% +information that you'll fill out uh on +education uh whether you've been a + + align:start position:0% +education uh whether you've been a + + + align:start position:0% +education uh whether you've been a +member of a union uh age and other + + align:start position:0% +member of a union uh age and other + + + align:start position:0% +member of a union uh age and other +factors uh they're all required except + + align:start position:0% +factors uh they're all required except + + + align:start position:0% +factors uh they're all required except +uh the gender item um which is optional + + align:start position:0% +uh the gender item um which is optional + + + align:start position:0% +uh the gender item um which is optional +but again once you finish uh filling out + + align:start position:0% +but again once you finish uh filling out + + + align:start position:0% +but again once you finish uh filling out +those different items you'll click next + + align:start position:0% +those different items you'll click next + + + align:start position:0% +those different items you'll click next +and you go onto a screen that now asks + + align:start position:0% +and you go onto a screen that now asks + + + align:start position:0% +and you go onto a screen that now asks +you to tell us about your preferences or + + align:start position:0% +you to tell us about your preferences or + + + align:start position:0% +you to tell us about your preferences or +priorities before negotiations begins + + align:start position:0% +priorities before negotiations begins + + + align:start position:0% +priorities before negotiations begins +you'll see that there's five different + + align:start position:0% +you'll see that there's five different + + + align:start position:0% +you'll see that there's five different +um issues about Workforce capability all + + align:start position:0% +um issues about Workforce capability all + + + align:start position:0% +um issues about Workforce capability all +of which could be subjects of + + align:start position:0% +of which could be subjects of + + + align:start position:0% +of which could be subjects of +negotiation and we want you to rank + + align:start position:0% +negotiation and we want you to rank + + + align:start position:0% +negotiation and we want you to rank +order them from your top priority to + + align:start position:0% +order them from your top priority to + + + align:start position:0% +order them from your top priority to +your second third fourth and fifth no + + align:start position:0% +your second third fourth and fifth no + + + align:start position:0% +your second third fourth and fifth no +ties here you have to pick one two 3 + + align:start position:0% +ties here you have to pick one two 3 + + + align:start position:0% +ties here you have to pick one two 3 +four or five for each of the five items + + align:start position:0% +four or five for each of the five items + + + align:start position:0% +four or five for each of the five items +there's also some questions about + + align:start position:0% +there's also some questions about + + + align:start position:0% +there's also some questions about +representation about organizational + + align:start position:0% +representation about organizational + + + align:start position:0% +representation about organizational +performance uh about compensation uh and + + align:start position:0% +performance uh about compensation uh and + + + align:start position:0% +performance uh about compensation uh and +rewards and incentives for managers as + + align:start position:0% +rewards and incentives for managers as + + + align:start position:0% +rewards and incentives for managers as +well as work family kinds of issues all + + align:start position:0% +well as work family kinds of issues all + + + align:start position:0% +well as work family kinds of issues all +of these are questions that indicate + + align:start position:0% +of these are questions that indicate + + + align:start position:0% +of these are questions that indicate +your priorities going in and frankly + + align:start position:0% +your priorities going in and frankly + + + align:start position:0% +your priorities going in and frankly +that get you thinking about what's at + + align:start position:0% +that get you thinking about what's at + + + align:start position:0% +that get you thinking about what's at +stake as you think about the future of + + align:start position:0% +stake as you think about the future of + + + align:start position:0% +stake as you think about the future of +work finally before we go on to the next + + align:start position:0% +work finally before we go on to the next + + + align:start position:0% +work finally before we go on to the next +screen in each of the five big + + align:start position:0% +screen in each of the five big + + + align:start position:0% +screen in each of the five big +categories Each of which had five sub + + align:start position:0% +categories Each of which had five sub + + + align:start position:0% +categories Each of which had five sub +questions we want you to rank order + + align:start position:0% +questions we want you to rank order + + + align:start position:0% +questions we want you to rank order +those in terms of what's important in + + align:start position:0% +those in terms of what's important in + + + align:start position:0% +those in terms of what's important in +the role that you're playing and again + + align:start position:0% +the role that you're playing and again + + + align:start position:0% +the role that you're playing and again +you'll press next and go on to the next + + align:start position:0% +you'll press next and go on to the next + + + align:start position:0% +you'll press next and go on to the next +screen here there's a couple of short + + align:start position:0% +screen here there's a couple of short + + + align:start position:0% +screen here there's a couple of short +attitude questions about cooperation and + + align:start position:0% +attitude questions about cooperation and + + + align:start position:0% +attitude questions about cooperation and +competition again these will be quick + + align:start position:0% +competition again these will be quick + + + align:start position:0% +competition again these will be quick +and they give us your attitudes before + + align:start position:0% +and they give us your attitudes before + + + align:start position:0% +and they give us your attitudes before +we begin the + + align:start position:0% +we begin the + + + align:start position:0% +we begin the +bargaining that's the setup now we're + + align:start position:0% +bargaining that's the setup now we're + + + align:start position:0% +bargaining that's the setup now we're +getting ready to bargain you'll see that + + align:start position:0% +getting ready to bargain you'll see that + + + align:start position:0% +getting ready to bargain you'll see that +there's a slide that tells you and a set + + align:start position:0% +there's a slide that tells you and a set + + + align:start position:0% +there's a slide that tells you and a set +of materials about preparation the key + + align:start position:0% +of materials about preparation the key + + + align:start position:0% +of materials about preparation the key +thing about preparation is to not just + + align:start position:0% +thing about preparation is to not just + + + align:start position:0% +thing about preparation is to not just +think about your own priorities and + + align:start position:0% +think about your own priorities and + + + align:start position:0% +think about your own priorities and +frankly your underlying interest but to + + align:start position:0% +frankly your underlying interest but to + + + align:start position:0% +frankly your underlying interest but to +think about the priorities and the + + align:start position:0% +think about the priorities and the + + + align:start position:0% +think about the priorities and the +interest what's really at stake for the + + align:start position:0% +interest what's really at stake for the + + + align:start position:0% +interest what's really at stake for the +people in the other + + align:start position:0% +people in the other + + + align:start position:0% +people in the other +roles and so the prep preparation + + align:start position:0% +roles and so the prep preparation + + + align:start position:0% +roles and so the prep preparation +materials will get you up to speed I'm + + align:start position:0% +materials will get you up to speed I'm + + + align:start position:0% +materials will get you up to speed I'm +moving through it quickly but there's a + + align:start position:0% +moving through it quickly but there's a + + + align:start position:0% +moving through it quickly but there's a +lot here to read that will help you in + + align:start position:0% +lot here to read that will help you in + + + align:start position:0% +lot here to read that will help you in +negotiations we say the three things + + align:start position:0% +negotiations we say the three things + + + align:start position:0% +negotiations we say the three things +that are most important are preparation + + align:start position:0% +that are most important are preparation + + + align:start position:0% +that are most important are preparation +preparation and preparation just like in + + align:start position:0% +preparation and preparation just like in + + + align:start position:0% +preparation and preparation just like in +real estate um location location and + + align:start position:0% +real estate um location location and + + + align:start position:0% +real estate um location location and +location this time is time that's well + + align:start position:0% +location this time is time that's well + + + align:start position:0% +location this time is time that's well +spent at this point now you've committed + + align:start position:0% +spent at this point now you've committed + + + align:start position:0% +spent at this point now you've committed +to bargain You've Got Your Role you've + + align:start position:0% +to bargain You've Got Your Role you've + + + align:start position:0% +to bargain You've Got Your Role you've +done your preparation and we're ready to + + align:start position:0% +done your preparation and we're ready to + + + align:start position:0% +done your preparation and we're ready to +begin negotiations I'm going to say a + + align:start position:0% +begin negotiations I'm going to say a + + + align:start position:0% +begin negotiations I'm going to say a +little bit about the negotiations and + + align:start position:0% +little bit about the negotiations and + + + align:start position:0% +little bit about the negotiations and +then we're going to talk about um the + + align:start position:0% +then we're going to talk about um the + + + align:start position:0% +then we're going to talk about um the +what happens afterwards you'll see that + + align:start position:0% +what happens afterwards you'll see that + + + align:start position:0% +what happens afterwards you'll see that +there's a link to the settlement form + + align:start position:0% +there's a link to the settlement form + + + align:start position:0% +there's a link to the settlement form +which I'll show you in a minute but + + align:start position:0% +which I'll show you in a minute but + + + align:start position:0% +which I'll show you in a minute but +there's also um I'm sorry there's also a + + align:start position:0% +there's also um I'm sorry there's also a + + + align:start position:0% +there's also um I'm sorry there's also a +page that's not on here but that will + + align:start position:0% +page that's not on here but that will + + + align:start position:0% +page that's not on here but that will +come uh on your screen that will let you + + align:start position:0% +come uh on your screen that will let you + + + align:start position:0% +come uh on your screen that will let you +print out all of your preparation + + align:start position:0% +print out all of your preparation + + + align:start position:0% +print out all of your preparation +choices either in a PDF or in a printed + + align:start position:0% +choices either in a PDF or in a printed + + + align:start position:0% +choices either in a PDF or in a printed +document so that you've got that in + + align:start position:0% +document so that you've got that in + + + align:start position:0% +document so that you've got that in +front of you when it comes to the actual + + align:start position:0% +front of you when it comes to the actual + + + align:start position:0% +front of you when it comes to the actual +bargaining um I'm going to just give you + + align:start position:0% +bargaining um I'm going to just give you + + + align:start position:0% +bargaining um I'm going to just give you +a very simple + + align:start position:0% +a very simple + + + align:start position:0% +a very simple +example let's say in the opening + + align:start position:0% +example let's say in the opening + + + align:start position:0% +example let's say in the opening +statement and you'll all make opening + + align:start position:0% +statement and you'll all make opening + + + align:start position:0% +statement and you'll all make opening +state ments and this is of course + + align:start position:0% +state ments and this is of course + + + align:start position:0% +state ments and this is of course +virtual negotiation so you'll be writing + + align:start position:0% +virtual negotiation so you'll be writing + + + align:start position:0% +virtual negotiation so you'll be writing +it out online for the others in your + + align:start position:0% +it out online for the others in your + + + align:start position:0% +it out online for the others in your +group to see uh the folks who are in the + + align:start position:0% +group to see uh the folks who are in the + + + align:start position:0% +group to see uh the folks who are in the +workers role might say there ought to be + + align:start position:0% +workers role might say there ought to be + + + align:start position:0% +workers role might say there ought to be +more government grants for skills + + align:start position:0% +more government grants for skills + + + align:start position:0% +more government grants for skills +training the person in the government + + align:start position:0% +training the person in the government + + + align:start position:0% +training the person in the government +role may say we're willing to provide + + align:start position:0% +role may say we're willing to provide + + + align:start position:0% +role may say we're willing to provide +some funding but only in areas that are + + align:start position:0% +some funding but only in areas that are + + + align:start position:0% +some funding but only in areas that are +skill shortages in society management + + align:start position:0% +skill shortages in society management + + + align:start position:0% +skill shortages in society management +might say yes but the grant should be + + align:start position:0% +might say yes but the grant should be + + + align:start position:0% +might say yes but the grant should be +the to the employers since they know + + align:start position:0% +the to the employers since they know + + + align:start position:0% +the to the employers since they know +what the skills are not just to the + + align:start position:0% +what the skills are not just to the + + + align:start position:0% +what the skills are not just to the +individuals + + align:start position:0% +individuals + + + align:start position:0% +individuals +the education providers say this needs + + align:start position:0% +the education providers say this needs + + + align:start position:0% +the education providers say this needs +to be part of an integrated education + + align:start position:0% +to be part of an integrated education + + + align:start position:0% +to be part of an integrated education +system and so uh These funds for + + align:start position:0% +system and so uh These funds for + + + align:start position:0% +system and so uh These funds for +curriculum development ought to come to + + align:start position:0% +curriculum development ought to come to + + + align:start position:0% +curriculum development ought to come to +the education institutions so that they + + align:start position:0% +the education institutions so that they + + + align:start position:0% +the education institutions so that they +can provide the new training that's + + align:start position:0% +can provide the new training that's + + + align:start position:0% +can provide the new training that's +needed government may say that's all + + align:start position:0% +needed government may say that's all + + + align:start position:0% +needed government may say that's all +great but um we need to have a funding + + align:start position:0% +great but um we need to have a funding + + + align:start position:0% +great but um we need to have a funding +mechanism let's say one cent per hour + + align:start position:0% +mechanism let's say one cent per hour + + + align:start position:0% +mechanism let's say one cent per hour +for the people that work management as + + align:start position:0% +for the people that work management as + + + align:start position:0% +for the people that work management as +you see here might say well we're + + align:start position:0% +you see here might say well we're + + + align:start position:0% +you see here might say well we're +education providers so we should be able + + align:start position:0% +education providers so we should be able + + + align:start position:0% +education providers so we should be able +to get development funds too ultimately + + align:start position:0% +to get development funds too ultimately + + + align:start position:0% +to get development funds too ultimately +the management the workers and the + + align:start position:0% +the management the workers and the + + + align:start position:0% +the management the workers and the +education providers might come together + + align:start position:0% +education providers might come together + + + align:start position:0% +education providers might come together +and say we need to provide governance + + align:start position:0% +and say we need to provide governance + + + align:start position:0% +and say we need to provide governance +and insight and input into this + + align:start position:0% +and insight and input into this + + + align:start position:0% +and insight and input into this +government initiative and together they + + align:start position:0% +government initiative and together they + + + align:start position:0% +government initiative and together they +might then outline what an agreement is + + align:start position:0% +might then outline what an agreement is + + + align:start position:0% +might then outline what an agreement is +but as you can see it there's a series + + align:start position:0% +but as you can see it there's a series + + + align:start position:0% +but as you can see it there's a series +of iterative proposals and + + align:start position:0% +of iterative proposals and + + + align:start position:0% +of iterative proposals and +counterproposals that are all part of + + align:start position:0% +counterproposals that are all part of + + + align:start position:0% +counterproposals that are all part of +the negotiations and in the end we're + + align:start position:0% +the negotiations and in the end we're + + + align:start position:0% +the negotiations and in the end we're +not looking for a simple sentence we had + + align:start position:0% +not looking for a simple sentence we had + + + align:start position:0% +not looking for a simple sentence we had +an agreement on government funded + + align:start position:0% +an agreement on government funded + + + align:start position:0% +an agreement on government funded +education we're really looking for two + + align:start position:0% +education we're really looking for two + + + align:start position:0% +education we're really looking for two +or three paragraphs that says who does + + align:start position:0% +or three paragraphs that says who does + + + align:start position:0% +or three paragraphs that says who does +what what are they agreeing to how will + + align:start position:0% +what what are they agreeing to how will + + + align:start position:0% +what what are they agreeing to how will +be it funded and what are the outcomes + + align:start position:0% +be it funded and what are the outcomes + + + align:start position:0% +be it funded and what are the outcomes +involved + + align:start position:0% +involved + + + align:start position:0% +involved +now we've done this many times and it + + align:start position:0% +now we've done this many times and it + + + align:start position:0% +now we've done this many times and it +turns out this issue um support for + + align:start position:0% +turns out this issue um support for + + + align:start position:0% +turns out this issue um support for +worker training is a common issue that + + align:start position:0% +worker training is a common issue that + + + align:start position:0% +worker training is a common issue that +people + + align:start position:0% +people + + + align:start position:0% +people +pick we want you to push the envelope + + align:start position:0% +pick we want you to push the envelope + + + align:start position:0% +pick we want you to push the envelope +about what's needed in the future of + + align:start position:0% +about what's needed in the future of + + + align:start position:0% +about what's needed in the future of +work so we're going to say that at least + + align:start position:0% +work so we're going to say that at least + + + align:start position:0% +work so we're going to say that at least +for your first two agreements they + + align:start position:0% +for your first two agreements they + + + align:start position:0% +for your first two agreements they +cannot be agreements that are on this + + align:start position:0% +cannot be agreements that are on this + + + align:start position:0% +cannot be agreements that are on this +issue of government funded uh education + + align:start position:0% +issue of government funded uh education + + + align:start position:0% +issue of government funded uh education +but on other issues that are among the + + align:start position:0% +but on other issues that are among the + + + align:start position:0% +but on other issues that are among the +many 25 issues that we've highlighted in + + align:start position:0% +many 25 issues that we've highlighted in + + + align:start position:0% +many 25 issues that we've highlighted in +five + + align:start position:0% +five + + + align:start position:0% +five +categories uh and then then if you want + + align:start position:0% +categories uh and then then if you want + + + align:start position:0% +categories uh and then then if you want +to come back to this as part of a + + align:start position:0% +to come back to this as part of a + + + align:start position:0% +to come back to this as part of a +package great but the point is um push + + align:start position:0% +package great but the point is um push + + + align:start position:0% +package great but the point is um push +the envelope do something new once you + + align:start position:0% +the envelope do something new once you + + + align:start position:0% +the envelope do something new once you +have an agreement you'll then follow the + + align:start position:0% +have an agreement you'll then follow the + + + align:start position:0% +have an agreement you'll then follow the +URL to a screen that looks like what you + + align:start position:0% +URL to a screen that looks like what you + + + align:start position:0% +URL to a screen that looks like what you +see here it says it's part two and again + + align:start position:0% +see here it says it's part two and again + + + align:start position:0% +see here it says it's part two and again +It'll ask you what group number you are + + align:start position:0% +It'll ask you what group number you are + + + align:start position:0% +It'll ask you what group number you are +at what institution are you doing this + + align:start position:0% +at what institution are you doing this + + + align:start position:0% +at what institution are you doing this +and then you'll find that there's a + + align:start position:0% +and then you'll find that there's a + + + align:start position:0% +and then you'll find that there's a +question about what role are you in how + + align:start position:0% +question about what role are you in how + + + align:start position:0% +question about what role are you in how +many people are part of this agreement + + align:start position:0% +many people are part of this agreement + + + align:start position:0% +many people are part of this agreement +um and what were their roles so + + align:start position:0% +um and what were their roles so + + + align:start position:0% +um and what were their roles so +obviously if you are an education + + align:start position:0% +obviously if you are an education + + + align:start position:0% +obviously if you are an education +institution you would check management + + align:start position:0% +institution you would check management + + + align:start position:0% +institution you would check management +labor and federal government and leave + + align:start position:0% +labor and federal government and leave + + + align:start position:0% +labor and federal government and leave +education blank on question five but at + + align:start position:0% +education blank on question five but at + + + align:start position:0% +education blank on question five but at +that point you go to the next screen and + + align:start position:0% +that point you go to the next screen and + + + align:start position:0% +that point you go to the next screen and +this is your chance to indicate what you + + align:start position:0% +this is your chance to indicate what you + + + align:start position:0% +this is your chance to indicate what you +actually agreed to You'll click let's + + align:start position:0% +actually agreed to You'll click let's + + + align:start position:0% +actually agreed to You'll click let's +say fair treatment and a screen will + + align:start position:0% +say fair treatment and a screen will + + + align:start position:0% +say fair treatment and a screen will +open up saying write into this what you + + align:start position:0% +open up saying write into this what you + + + align:start position:0% +open up saying write into this what you +agreed upon this is important each of + + align:start position:0% +agreed upon this is important each of + + + align:start position:0% +agreed upon this is important each of +you will be entering the agreement + + align:start position:0% +you will be entering the agreement + + + align:start position:0% +you will be entering the agreement +separately so if there's four people in + + align:start position:0% +separately so if there's four people in + + + align:start position:0% +separately so if there's four people in +the negotiations there'll be four + + align:start position:0% +the negotiations there'll be four + + + align:start position:0% +the negotiations there'll be four +entries of the text it's perfectly okay + + align:start position:0% +entries of the text it's perfectly okay + + + align:start position:0% +entries of the text it's perfectly okay +for you to each cut and splice the same + + align:start position:0% +for you to each cut and splice the same + + + align:start position:0% +for you to each cut and splice the same +language um but the key thing and by the + + align:start position:0% +language um but the key thing and by the + + + align:start position:0% +language um but the key thing and by the +way if you put in different language + + align:start position:0% +way if you put in different language + + + align:start position:0% +way if you put in different language +that's evidence that it might not be a + + align:start position:0% +that's evidence that it might not be a + + + align:start position:0% +that's evidence that it might not be a +very stable agreement but the point is + + align:start position:0% +very stable agreement but the point is + + + align:start position:0% +very stable agreement but the point is +you each put in your language because we + + align:start position:0% +you each put in your language because we + + + align:start position:0% +you each put in your language because we +also ask you to each rate how important + + align:start position:0% +also ask you to each rate how important + + + align:start position:0% +also ask you to each rate how important +is this in terms of your role uh and how + + align:start position:0% +is this in terms of your role uh and how + + + align:start position:0% +is this in terms of your role uh and how +satisfied you are you with the process + + align:start position:0% +satisfied you are you with the process + + + align:start position:0% +satisfied you are you with the process +not just the substance to get to this + + align:start position:0% +not just the substance to get to this + + + align:start position:0% +not just the substance to get to this +agreement and this way we can hear from + + align:start position:0% +agreement and this way we can hear from + + + align:start position:0% +agreement and this way we can hear from +each of you in the negotiations and of + + align:start position:0% +each of you in the negotiations and of + + + align:start position:0% +each of you in the negotiations and of +course there's a space for you to say if + + align:start position:0% +course there's a space for you to say if + + + align:start position:0% +course there's a space for you to say if +there's anything else that you want to + + align:start position:0% +there's anything else that you want to + + + align:start position:0% +there's anything else that you want to +put and that completes uh the process + + align:start position:0% +put and that completes uh the process + + + align:start position:0% +put and that completes uh the process +there's a link here that will let you um + + align:start position:0% +there's a link here that will let you um + + + align:start position:0% +there's a link here that will let you um +come back and enter a second or third + + align:start position:0% +come back and enter a second or third + + + align:start position:0% +come back and enter a second or third +agreement and when you're done when when + + align:start position:0% +agreement and when you're done when when + + + align:start position:0% +agreement and when you're done when when +you're done you will have done something + + align:start position:0% +you're done you will have done something + + + align:start position:0% +you're done you will have done something +very special which is you will have + + align:start position:0% +very special which is you will have + + + align:start position:0% +very special which is you will have +negotiated an agreement about the future + + align:start position:0% +negotiated an agreement about the future + + + align:start position:0% +negotiated an agreement about the future +of + + align:start position:0% +of + + + align:start position:0% +of +work people who are in positions of + + align:start position:0% +work people who are in positions of + + + align:start position:0% +work people who are in positions of +power and authority are interested to + + align:start position:0% +power and authority are interested to + + + align:start position:0% +power and authority are interested to +see what comes out of the negotiations + + align:start position:0% +see what comes out of the negotiations + + + align:start position:0% +see what comes out of the negotiations +in this course we will try to sum up the + + align:start position:0% +in this course we will try to sum up the + + + align:start position:0% +in this course we will try to sum up the +agreements and look for insights and + + align:start position:0% +agreements and look for insights and + + + align:start position:0% +agreements and look for insights and +lessons around which there might be the + + align:start position:0% +lessons around which there might be the + + + align:start position:0% +lessons around which there might be the +kind of alignment that could actually + + align:start position:0% +kind of alignment that could actually + + + align:start position:0% +kind of alignment that could actually +change things in society and ensure that + + align:start position:0% +change things in society and ensure that + + + align:start position:0% +change things in society and ensure that +the institutions of work are better + + align:start position:0% +the institutions of work are better + + + align:start position:0% +the institutions of work are better +designed to serve the needs of yourself + + align:start position:0% +designed to serve the needs of yourself + + + align:start position:0% +designed to serve the needs of yourself +and others in the future Generations + + align:start position:0% +and others in the future Generations + + + align:start position:0% +and others in the future Generations +thank you very much \ No newline at end of file diff --git a/MCrDzhpu3-s.txt b/MCrDzhpu3-s.txt new file mode 100644 index 0000000000000000000000000000000000000000..6fbc6cba187ed3b2bd7f9ee8d0cc6779b8b822d9 --- /dev/null +++ b/MCrDzhpu3-s.txt @@ -0,0 +1,2066 @@ +For the rest of the term, +we are going to be studying not + +just one differential equation +at a time, but rather what are + +called systems of differential +equations. + +Those are like systems of +linear equations. + +They have to be solved +simultaneously, + +in other words, +not just one at a time. + +So, how does a system look when +you write it down? + +Well, since we are going to be +talking about systems of + +ordinary differential equations, +there still will be only one + +independent variable, +but there will be several + +dependent variables. +I am going to call, + +let's say two. +The dependent variables are + +going to be, I will call them x +and y, and then the first order + +system, something involving just +first derivatives, + +will look like this. +On the left-hand side + +will be x prime, + +in other words. +On the right-hand side will be + +the dependent variables and then +also the independent variables. + +I will indicate that, +I will separate it all from the + +others by putting a semicolon +there. + +And the same way y prime, +the derivative of y with + +respect to t, +will be some other function of + +(x, y) and t. +Let's write down explicitly + +that x and y are dependent +variables. + +And what they depend upon is +the independent variable t, + +time. +A system like this is going to + +be called first order. +And we are going to consider + +basically only first-order +systems for a secret reason that + +I will explain at the end of the +period. + +This is a first-order system, +meaning that the only kind of + +derivatives that are up here are +first derivatives. + +So x prime is dx over dt +and so on. + +Now, there is still more +terminology. + +Of course, practically all the +equations after the term + +started, virtually all the +equations we have been + +considering are linear +equations, so it must be true + +that linear systems are the best +kind. + +And, boy, they certainly are. +When are we going to call a + +system linear? +I think in the beginning you + +should learn a little +terminology before we launch in + +and actually try to start to +solve these things. + +Well, the x and y, +the dependent variables must + +occur linearly. +In other words, + +it must look like this, +ax plus by. + +Now, the t can be a mess. +And so I will throw in an extra + +function of t there. +And y prime will be some + +other linear combination of x +and y, plus some other messy + +function of t. +But even the a, + +b, c, and d are allowed to be +functions of t. + +They could be one over t cubed +or sine t + +or something like that. +So I have to distinguish those + +cases. +The case where a, + +b, c, and d are constants, +that I will call -- + +Well, there are different +things you can call it. + +We will simply call it a +constant coefficient system. + +A system with coefficients +would probably be better + +English. +On the other hand, + +a, b, c, and d, +this system will still be + +called linear if these are +functions of t. + +Can also be functions of t. + +So it would be a perfectly good +linear system to have x prime + +equals tx plus sine t times y +plus e to the minus t squared. + +You would never see something +like that but it is okay. + +What else do you need to know? +Well, what would a homogenous + +system be? +A homogenous system is one + +without these extra guys. +That doesn't mean there is no t + +in it. +There could be t in the a, + +b, c and d, but these terms +with no x and y in them must not + +occur. +So, a linear homogenous. + +And that is the kind we are +going to start studying first in + +the same way when we studied +higher order equations. + +We studied first homogenous. +You had to know how to solve + +those first, and then you could +learn how to solve the more + +general kind. +So linear homogenous means that + +r1 is zero and r2 is zero for +all time. + +They are identically zero. +They are not there. + +You don't see them. +Have I left anything out? + +Yes, the initial conditions. +Since that is quite general, + +let's talk about what would +initial conditions look like? + +Well, in a general way, +the reason you have to have + +initial conditions is to get +values for the arbitrary + +constants that appear in the +solution. + +The question is, +how many arbitrary constants + +are going to appear in the +solutions of these equations? + +Well, I will just give you the +answer. + +Two. +The number of arbitrary + +constants that appear is the +total order of the system. + +For example, +if this were a second + +derivative and this were a first +derivative, I would expect three + +arbitrary constants in the +system -- + +-- because the total, +the sum of two and one makes + +three. +So you must have as many + +initial conditions as you have +arbitrary constants in the + +solution. +And that, of course, + +explains when we studied +second-order equations, + +we had to have two initial +conditions. + +I had to specify the initial +starting point and the initial + +velocity. +And the reason we had to have + +two conditions was because the +general solution had two + +arbitrary constants in it. +The same thing happens here but + +the answer is it is more +natural, the conditions here are + +more natural. +I don't have to specify the + +velocity. +Why not? + +Well, because an initial +condition, of course, + +would want me to say what the +starting value of x is, + +some number, +and it will also want to know + +what the starting value of y is +at that same point. + +Well, there are my two +conditions. + +And since this is going to have +two arbitrary constants in it, + +it is these initial conditions +that will satisfy, + +the arbitrary constants will +have to be picked so as to + +satisfy those initial +conditions. + +In some sense, +the giving of initial + +conditions for a system is a +more natural activity than + +giving the initial conditions of +a second order system. + +You don't have to be the least +bit cleaver about it. + +Anybody would give these two +numbers. + +Whereas, somebody faced with a +second order system might + +scratch his head. +And, in fact, + +there are other kinds of +conditions. + +There are boundary conditions +you learned a little bit about + +instead of initial conditions +for a second order equation. + +I cannot think of any more +general terminology, + +so it sounds like we are going +to actually have to get to work. + +Okay, let's get to work. +I want to set up a system and + +solve it. +And since one of the things in + +this course is supposed to be +simple modeling, + +it should be a system that +models something. + +In general, the kinds of models +we are going to use when we + +study systems are the same ones +we used in studying just + +first-order equations. +Mixing, radioactive decay, + +temperature, +the motion of temperature. + +Heat, heat conduction, +in other words. + +Diffusion. +I have given you a diffusion + +problem for your first homework +on this subject. + +What else did we do? +That's all I can think of for + +the moment, but I am sure they +will occur to me. + +When, out of those physical +ideas, are we going to get a + +system? +The answer is, + +whenever there are two of +something that there was only + +one of before. +For example, + +if I have mixing with two tanks +where the fluid goes like that. + +Say you want to have a big tank +and a little tank here and you + +want to put some stuff into the +little tank so that it will get + +mixed in the big tank without +having to climb a big ladder and + +stop and drop the stuff in. +That will require two tanks, + +the concentration of the +substance in each tank, + +therefore, that will require a +system of equations rather than + +just one. +Or, to give something closer to + +home, closer to this backboard, +anyway, suppose you have dah, + +dah, dah, don't groan, +at least not audibly, + +something that looks like that. +And next to it put an EMF + +there. +That is just a first order. + +That just leads to a single +first order equation. + +But suppose it is a two loop +circuit. + +Now I need a pair of equations. +Each of these loops gives a + +first order differential +equation, but they have to be + +solved simultaneously to find +the current or the charges on + +the condensers. +And if I want a system of three + +equations, throw in another +loop. + +Now, suppose I put in a coil +instead. + +What is this going to lead to? +This is going to give me a + +system of three equations of +which this will be first order, + +first order. +And this will be second order + +because it has a coil. +You are up to that, + +right? +You've had coils, + +inductance? +Good. + +So the whole thing is going to +count as first-order, + +first-order, +second-order. + +To find out how complicated it +is, you have to add up the + +orders. +That is one and one, + +and two. +This is really fourth-order + +stuff that we are talking about +here. + +We can expect it to be a little +complicated. + +Well, now let's take a modest +little problem. + +I am going to return to a +problem we considered earlier in + +the problem of heat conduction. +I had forgotten whether it was + +on the problem set or I did it +in class, but I am choosing it + +because it leads to something we +will be able to solve. + +And because it illustrates how +to add a little sophistication + +to something that was +unsophisticated before. + +A pot of water. +External temperature Te of t. + +I am talking about the + +temperature of something. +And what I am talking about the + +temperature of will be an egg +that is cooking inside, + +but with a difference. +This egg is not homogenous + +inside. +Instead it has a white and it + +has a yolk in the middle. +In other words, + +it is a real egg and not a +phony egg. + +That is a small pot, +or it is an ostrich egg. + +[LAUGHTER] That is the yoke. +The yolk is contained in a + +little membrane inside. +And there are little yucky + +things that hold it in position. +And we are going to let the + +temperature of the yolk, +if you can see in the back of + +the room, be T1. +That is the temperature of the + +yolk. +The temperature of the white, + +which we will assume is +uniform, is going to be T2. + +Oh, that's the water bath. +The temperature of the white is + +T2, and then the temperature of +the external water bath. + +In other words, +the reason for introducing two + +variables instead of just the +one variable for the overall + +temperature of the egg we had is +because egg white is liquid pure + +protein, more or less, +and the T1, the yolk has a lot + +of fat and cholesterol and other +stuff like that which is + +supposed to be bad for you. +It certainly has different + +conducting. +It is liquid, + +at the beginning at any rate, +but it certainly has different + +constants of conductivity than +the egg white would. + +And the condition of heat +through the shell of the egg + +would be different from the +conduction of heat through the + +membrane that keeps the yoke +together. + +So it is quite reasonable to +consider that the white and the + +yolk will be at different +temperatures and will have + +different conductivity +properties. + +I am going to use Newton's laws +but with this further + +refinement. +In other words, + +introducing two temperatures. +Whereas, before we only had one + +temperature. +But let's use Newton's law. + +Let's see. +The question is how does T1, + +the temperature of the yolk, +vary with time? + +Well, the yolk is getting all +its heat from the white. + +Therefore, Newton's law of +conduction will be some constant + +of conductivity for the yolk +times T2 minus T1. + +The yolk does not know anything +about the external temperature + +of the water bath. +It is completely surrounded, + +snug and secure within itself. +But how about the temperature + +of the egg white? +That gets heat and gives heat + +to two sources, +from the external water and + +also from the internal yolk +inside. + +So you have to take into +account both of those. + +Its conduction of the heat +through that membrane, + +we will use the same a, +which is going to be a times T1 + +minus T2. +Remember the order in which you + +have to write these is governed +by the yolk outside to the + +white. +Therefore, that has to come + +first when I write it in order +that a be a positive constant. + +But it is also getting heat +from the water bath. + +And, presumably, +the conductivity through the + +shell is different from what it +is through this membrane around + +the yolk. +So I am going to call that by a + +different constant. +This is the conductivity + +through the shell into the +white. + +And that is going to be T, +the external temperature minus + +the temperature of the egg +white. + +Here I have a system of +equations because I want to make + +two dependent variables by +refining the original problem. + +Now, you always have to write a +system in standard form to solve + +it. +You will see that the left-hand + +side will give the dependent +variables in a certain order. + +In this case, +the temperature of the yolk and + +then the temperature of the +white. + +The law is that in order not to +make mistakes -- + +And it's a very frequent source +of error so learn from the + +beginning not to do this. +You must write the variables on + +the right-hand side in the same +order left to right in which + +they occur top to bottom here. +In other words, + +this is not a good way to leave +that. + +This is the first attempt in +writing this system, + +but the final version should +like this. + +T1 prime, +I won't bother writing dT / dt, + +is equal to -- +T1 must come first, + +so minus a times T1 plus a +times T2. + +And the same law for the second +one. + +It must come in the same order. +Now, the coefficient of T1, + +that is easy. +That's a times T1. + +The coefficient of T2 is minus +a minus b, + +so minus (a plus b) times T2. + +But I am not done yet. +There is still this external + +temperature I must put into the +equation. + +Now, that is not a variable. +This is some given function of + +t. +And what the function of t is, + +of course, depends upon what +the problem is. + +So that, for example, +what might be some + +possibilities, +well, suppose the problem was I + +wanted to coddle the egg. +I think there is a generation + +gap here. +How many of you know what a + +coddled egg is? +How many of you don't know? + +Well, I'm just saying my +daughter didn't know. + +I mentioned it to her. +I said I think I'm going to do + +a coddled egg tomorrow in class. +And she said what is that? + +And so I said a cuddled egg? +She said why would someone + +cuddle an egg? +I said coddle. + +And she said, +oh, you mean like a person, + +like what you do to somebody +you like or don't like or I + +don't know. +Whatever. + +I thought a while and said, +yeah, more like that. + +[LAUGHTER] Anyway, +for the enrichment of your + +cooking skills, +to coddle an egg, + +it is considered to produce a +better quality product than + +boiling an egg. +That is why people do it. + +You heat up the water to +boiling, the egg should be at + +room temperature, +and then you carefully lower + +the egg into the water. +And you turn off the heat so + +the water bath cools +exponentially while the egg + +inside is rising in temperature. +And then you wait four minutes + +or six minutes or whatever and +take it out. + +You have a perfect egg. +So for coddling, + +spelled so, what will the +external temperature be? + +Well, it starts out at time +zero at 100 degrees centigrade + +because the water is supposed to +be boiling. + +The reason you have it boiling +is for calibration so that you + +can know what temperature it is +without having to use a + +thermometer, unless you're on +Pike's Peak or some place. + +It starts out at 100 degrees. +And after that, + +since the light is off, +it cools exponential because + +that is another law. +You only have to know what K is + +for your particular pot and you +will be able to solve the + +coddled egg problem. +In other words, + +you will then be able to solve +these equations and know how the + +temperature rises. +I am going to solve a different + +problem because I don't want to +have to deal with this + +inhomogeneous term. +Let's use, as a different + +problem, a person cooks an egg. +Coddles the egg by the first + +process, decides the egg is +done, let's say hardboiled, + +and then you are supposed to +drop a hardboiled egg into cold + +water. +Not just to cool it but also + +because I think it prevents that +dark thing from forming that + +looks sort of unattractive. +Let's ice bath. + +The only reason for dropping +the egg into an ice bath is so + +that you could have a homogenous +equation to solve. + +And since this a first system +we are going to solve, + +let's make life easy for +ourselves. + +Now, all my work in preparing +this example, + +and it took considerably longer +time than actually solving the + +problem, was in picking values +for a and b which would make + +everything come out nice. +It's harder than it looks. + +The values that we are going to +use, which make no physical + +sense whatsoever, +but a equals 2 and b + +equals 3. +These are called nice numbers. + +What is the equation? +What is the system? + +Can somebody read it off for +me? + +It is T1 prime equals, what +is it, minus 2T1 plus 2T2. + +That's good. + +Minus 2T1 plus 2T2. + +T2 prime is, +what is it? + +I think this is 2T1. +And the other one is minus a + +plus b, so minus 5. + +This is a system. +Now, on Wednesday I will teach + +you a fancy way of solving this. +But, to be honest, + +the fancy way will take roughly +about as long as the way I am + +going to do it now. +The main reason for doing it is + +that it introduces new +vocabulary which everyone wants + +you to have. +And also, more important + +reasons, it gives more insight +into the solution than this + +method. +This method just produces the + +answer, but you want insight, +also. + +And that is just as important. +But for now, + +let's use a method which always +works and which in 40 years, + +after you have forgotten all +other fancy methods, + +will still be available to you +because it is method you can + +figure out yourself. +You don't have to remember + +anything. +The method is to eliminate one + +of the dependent variables. +It is just the way you solve + +systems of linear equations in +general if you aren't doing + +something fancy with +determinants and matrices. + +If you just eliminate +variables. + +We are going to eliminate one +of these variables. + +Let's eliminate T2. +You could also eliminate T1. + +The main thing is eliminate one +of them so you will have just + +one left to work with. +How do I eliminate T2? + +Beg your pardon? +Is something wrong? + +If somebody thinks something is +wrong raise his hand. + +No? + +Why do I want to get rid of T1? +Well, I can add them. + +But, on the left-hand side, +I will have T1 prime plus T2 + +prime. What good is that? + +[LAUGHTER] + +I think you will want to do it +my way. + +[APPLAUSE] + +Solve for T2 in terms of T1. +That is going to be T1 prime + +plus 2T1 divided by 2. + +Now, take that and substitute +it into the second equation. + +Wherever you see a T2, +put that in, + +and what you will be left with +is something just in T1. + +To be honest, +I don't know any other good way + +of doing this. +There is a fancy method that I + +think is talked about in your +book, which leads to extraneous + +solutions and so on, +but you don't want to know + +about that. +This will work for a simple + +linear equation with constant +coefficients, + +always. +Substitute in. + +What do I do? +Now, here I do not advise doing + +this mentally. +It is just too easy to make a + +mistake. +Here, I will do it carefully, + +writing everything out just as +you would. + +T1 prime plus 2T1 over 2, +prime, equals 2T1 minus 5 time + +T1 prime plus 2T1 over two. + +I took that and substituted + +into this equation. +Now, I don't like those two's. + +Let's get rid of them by +multiplying. + +This will become 4. + +And now write this out. +What is this when you look at + +it? +This is an equation just in T1. + +It has constant coefficients. +And what is its order? + +Its order is two because T1 +prime primed. + +In other words, +I can eliminate T2 okay, + +but the equation I am going to +get is no longer a first-order. + +It becomes a second-order +differential equation. + +And that's a basic law. +Even if you have a system of + +more equations, +three or four or whatever, + +the law is that after you do +the elimination successfully and + +end up with a single equation, +normally the order of that + +equation will be the sum of the +orders of the things you started + +with. +So two first-order equations + +will always produce a +second-order equation in just + +one dependent variable, +three will produce a third + +order equation and so on. +So you trade one complexity for + +another. +You trade the complexity of + +having to deal with two +equations simultaneously instead + +of just one for the complexity +of having to deal with a single + +higher order equation which is +more trouble to solve. + +It is like all mathematical +problems. + +Unless you are very lucky, +if you push them down one way, + +they are really simple now, +they just pop up some place + +else. +You say, oh, + +I didn't save anything after +all. + +That is the law of conservation +of mathematical difficulty. + +[LAUGHTER] You saw that even +with the Laplace transform. + +In the beginning it looks +great, you've got these tables, + +take the equation, +horrible to solve. + +Take some transform, +trivial to solve for capital Y. + +Now I have to find the inverse +Laplace transform. + +And suddenly all the work is +there, partial fractions, + +funny formulas and so on. +It is very hard in mathematics + +to get away with something. +It happens now and then and + +everybody cheers. +Let's write this out now in the + +form in which it looks like an +equation we can actually solve. + +Just be careful. +Now it is all right to use the + +method by which you collect +terms. + +There is only one term +involving T1 double prime. + +It's the one that comes from +here. + +How about the terms in T1 +prime? + +There is a 2. +Here, there is minus 5 T1 + +prime. +If I put it on the other side + +it makes plus 5 T1 prime plus +this two makes 7 T1 prime. + +And how many T1's are there? +Well, none on the left-hand + +side. +On the right-hand side I have 4 + +here minus 10. +4 minus 10 is negative 6. + +Negative 6 T1 put on this +left-hand side the way we want + +to do makes plus 6 T1. + +There are no inhomogeneous +terms, so that is equal to zero. + +If I had gotten a negative +number for one of these + +coefficients, +I would instantly know if I had + +made a mistake. +Why? + +Why must those numbers come out +to be positive? + +It is because the system must +be, the system must be, + +fill in with one word, +stable. + +And why must this system be +stable? + +In other words, +the long-term solutions must be + +zero, must all go to zero, +whatever they are. + +Why is that? +Well, because you are putting + +the egg into an ice bath. +Or, because we know it was + +living but after being +hardboiled it is dead and, + +therefore, dead systems are +stable. + +That's not a good reason but it +is, so to speak, + +the real one. +It's clear anyway that all + +solutions must tend to zero +physically. + +That's obvious. +And, therefore, + +the differential equation must +have the same property, + +and that means that its +coefficients must be positive. + +All its coefficients must be +positive. + +If this weren't there, +I would get oscillating + +solutions, which wouldn't go to +zero. + +That is physical impossible for +this egg. + +Now the rest is just solving. +The characteristic equation, + +if you can remember way, +way back in prehistoric times + +when we were solving these +equations, is this. + +And what you want to do is +factor it. + +This is where all the work was, +getting those numbers so that + +this would factor. So it's +r plus 1 times r plus 6 + +And so the solutions are, +the roots are r equals + +negative 1. +I am just making marks on the + +board, but you have done this +often enough, + +you know what I am talking +about. + +So the characteristic roots are +those two numbers. + +And, therefore, +the solution is, + +I could write down immediately +with its arbitrary constant as + +c1 times e to the negative t +plus c2 times e to the negative + +6t. Now, I have got to get T2. + +Here the first worry is T2 is +going to give me two more + +arbitrary constants. +It better not. + +The system is only allowed to +have two arbitrary constants in + +its solution because that is the +initial conditions we are giving + +it. +By the way, I forgot to give + +initial conditions. +Let's give initial conditions. + +Let's say the initial +temperature of the yolk, + +when it is put in the ice bath, +is 40 degrees centigrade, + +Celsius. +And T2, let's say the white + +ought to be a little hotter than +the yolk is always cooler than + +the white for a soft boiled egg, +I don't know, + +or a hardboiled egg if it +hasn't been chilled too long. + +Let's make this 45. +Realistic numbers. + +Now, the thing not to do is to +say, hey, I found T1. + +Okay, I will find T2 by the +same procedure. + +I will go through the whole +thing. + +I will eliminate T1 instead. +Then I will end up with an + +equation T2 and I will solve +that and get T2 equals blah, + +blah, blah. +That is no good, + +A, because you are working too +hard and, B, because you are + +going to get two more arbitrary +constants unrelated to these + +two. +And that is no good. + +Because the correct solution +only has two constants in it. + +Not four. +So that procedure is wrong. + +You must calculate T2 from the +T1 that you found, + +and that is the equation which +does it. + +That's the one we have to have. +Where is the chalk? + +Yes. +Maybe I can have a little thing + +so I can just carry this around +with me. + +That is the relation between T2 +and T1. + +Or, if you don't like it, +either one of these equations + +will express T2 in terms of T1 +for you. + +It doesn't matter. +Whichever one you use, + +however you do it, +that's the way you must + +calculate T2. +So what is it? + +T2 is calculated from that pink +box. + +It is one-half of T1 prime plus +T1. + +Now, if I take the derivative +of this, I get minus c1 times + +the exponential. +The coefficient is minus c1, + +take half of that, +that is minus a half c1 + +and add it to T1. +Minus one-half c1 plus c1 gives + +me one-half c1. + +And here I take the derivative, +it is minus 6 c2. + +Take half of that, +minus 3 c2 and add this c2 to + +it, minus 3 plus 1 makes minus +2. + +That is T2. +And notice it uses the same + +arbitrary constants that T1 +uses. + +So we end up with just two +because we calculated T2 from + +that formula or from the +equation which is equivalent to + +it, not from scratch. +We haven't put in the initial + +conditions yet, +but that is easy to do. + +Everybody, when working with +exponentials, + +of course, you always want the +initial conditions to be when T + +is equal to zero +because that makes all the + +exponentials one and you don't +have to worry about them. + +But this you know. +If I put in the initial + +conditions, at time zero, +T1 has the value 40. + +So 40 should be equal to c1 + +c2. + +And the other equation will say +that 45 is equal to one-half c1 + +minus 2 c2. +Now we are supposed to + +solve these. +Well, this is called solving + +simultaneous linear equations. +We could use Kramer's rule, + +inverse matrices, +but why don't we just + +eliminate. +Let me see. + +If I multiply by, +45, so multiply by two, + +you get 90 equals c1 +minus 4 c2. + +Then subtract this guy from +that guy. + +So, 40 taken from 90 makes 50. +And c1 taken from c1, + +because I multiplied by two, +makes zero. + +And c2 taken from minus 4 c2, +that makes minus 5 c2, + +I guess. + +I seem to get c2 is equal to +negative 10. + +And if c2 is negative 10, +then c1 must be 50. + +There are two ways of checking +the answer. + +One is to plug it into the +equations, and the other is to + +peak. +Yes, that's right. + +[LAUGHTER] + +The final answer is, +in other words, + +you put a 50 here, +25 there, negative 10 here, + +and positive 20 there. +That gives the answer to the + +problem. +It tells you, + +in other words, +how the temperature of the yolk + +varies with time and how the +temperature of the white varies + +with time. +As I said, we are going to + +learn a slick way of doing this +problem, or at least a very + +different way of doing the same +problem next time, + +but let's put that on ice for +the moment. + +And instead I would like to +spend the rest of the period + +doing for first order systems +the same thing that I did for + +you the very first day of the +term. + +Remember, I walked in assuming +that you knew how to separate + +variables the first day of the +term, and I did not talk to you + +about how to solve fancier +equations by fancier methods. + +I instead talked to you about +the geometric significance, + +what the geometric meaning of a +single first order equation was + +and how that geometric meaning +enabled you to solve it + +numerically. +And we spent a little while + +working on such problems because +nowadays with computers it is + +really important that you get a +feeling for what these things + +mean as opposed to just +algorithms for solving them. + +As I say, most differential +equations, especially systems, + +are likely to be solved by a +computer anyway. + +You have to be the guiding +genius that interprets the + +answers and can see when +mistakes are being made, + +stuff like that. +The problem is, + +therefore, what is the meaning +of this system? + +Well, you are not going to get +anywhere interpreting it + +geometrically, +unless you get rid of that t on + +the right-hand side. +And the only way of getting rid + +of the t is to declare it is not +there. + +So I hereby declare that I will +only consider, + +for the rest of the period, +that is only ten minutes, + +systems in which no t appears +explicitly on the right-hand + +side. +Because I don't know what to do + +if it does up here. +We have a word for these. + +Remember what the first order +word was? + +A first order equation where +there was no t explicitly on the + +right-hand side, +we called it, + +anybody remember? +Just curious. + +Autonomous, right. + +This is an autonomous system. +It is not a linear system + +because these are messy +functions. + +This could be x times y +or x squared minus 3y squared + +divided by sine of x plus y. + +It could be a mess. +Definitely not linear. + +But autonomous means no t. +t means the independent + +variable appears on the +right-hand side. + +Of course, it is there. +It is buried in the dx/dt and + +dy/dt. +But it is not on the right-hand + +side. +No t appears on the right-hand + +side. + +Because no t appears on the +right-hand side, + +I can now draw a picture of +this. + +But, let's see, +what does a solution look like? + +I never even talked about what +a solution was, + +did I? +Well, pretend that immediately + +after I talked about that, +I talked about this. + +What is the solution? +Well, the solution, + +maybe you took it for granted, +is a pair of functions, + +x of t, y of t if when +you plug it in + +it satisfies the equation. +And so what else is new? + +The solution is x +equals x of t, + +y equals y of t. + +If I draw a picture of that +what would it look like? + +This is where your previous +knowledge of physics above all + +18.02, maybe 18.01 if you +learned this in high school, + +what is x equals x of t and +y equals y of t? + +How do you draw a picture of + +that? +What does it represent? + +A curve. +And what will be the title of + +the chapter of the calculus book +in which that is discussed? + +Parametric equations. +This is a parameterized curve. + +So we know what the solution +looks like. + +Our solution is a parameterized +curve. + +And what does a parameterized +curve look like? + +Well, it travels, +and in a certain direction. + +Okay. +That's enough. + +Why do I have several of those +curves? + +Well, because I have several +solutions. + +In fact, given any initial +starting point, + +there is a solution that goes +through it. + +I will put in possible starting +points. + +And you can do this on the +computer screen with a little + +program you will have, +one of the visuals you'll have. + +It's being made right now. +You put down starter point, + +put down a click, +and then it just draws the + +curve passing through that +point. + +Didn't we do this early in the +term? + +Yes. +But there is a difference now + +which I will explain. +These are various possible + +starting points at time zero for +this solution, + +and then you see what happens +to it afterwards. + +In fact, through every point in +the plane will pass a solution + +curve, parameterized curve. +Now, what is then the + +representation of this? +Well, what is the meaning of x + +prime of t and y prime of t? + +I am not going to worry for the +moment about the right-hand + +side. +What does this mean by itself? + +If this is the curve, +the parameterized motion, + +then this represents its +velocity vector. + +It is the velocity of the +solution at time t. + +If I think of the solution as +being a parameterized motion. + +All I have drawn here is the +trace, the path of the motion. + +This hasn't indicated how fast +it was going. + +One solution might go whoosh +and another one might go rah. + +That is a velocity, +and that velocity changes from + +point to point. +It changes direction. + +Well, we know its direction at +each point. + +That's tangent. +What I cannot tell is the + +speed. +From this picture, + +I cannot tell what the speed +was. + +Too bad. +Now, what is then the meaning + +of the system? +What the system does, + +it prescribes at each point the +velocity vector. + +If you tell me what the point +(x, y) is in the plane then + +these equations give you the +velocity vector at that point. + +And, therefore, +what I end up with, + +the system is what you call in +physics and what you call in + +18.02 a velocity field. +So at each point there is a + +certain vector. +The vector is always tangent to + +the solution curve through +there, but I cannot predict from + +just this picture what its +length will be because at some + +points, it might be going slow. +The solution might be going + +slowly. +In other words, + +the plane is filled up with +these guys. + +Stop me. +Not enough here. + +So on and so on. +We can say a system of first + +order equations, +ODEs of first order equations, + +autonomous because there must +be no t on the right-hand side, + +is equal to a velocity field. +A field of velocity. + +The plane covered with velocity +vectors. + +And a solution is a +parameterized curve with the + +right velocity everywhere. + +Now, there obviously must be a +connection between that and the + +direction fields we studied at +the beginning of the term. + +And there is. +It is a very important + +connection. +It is too important to talk + +about in minus one minute. +When we need it, + +I will have to spend some time +talking about it then. \ No newline at end of file diff --git a/ML5yVI18uaI.txt b/ML5yVI18uaI.txt new file mode 100644 index 0000000000000000000000000000000000000000..fa14a28c48154c60c4f0d98c2f73f3835607b1ab --- /dev/null +++ b/ML5yVI18uaI.txt @@ -0,0 +1,16735 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +to view additional materials from + + align:start position:0% +to view additional materials from + + + align:start position:0% +to view additional materials from +hundreds of MIT courses visit MIT open + + align:start position:0% +hundreds of MIT courses visit MIT open + + + align:start position:0% +hundreds of MIT courses visit MIT open +courseware at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu okay so for the ones that + + align:start position:0% +ocw.mit.edu okay so for the ones that + + + align:start position:0% +ocw.mit.edu okay so for the ones that +have just arrived uh I'm going to be + + align:start position:0% +have just arrived uh I'm going to be + + + align:start position:0% +have just arrived uh I'm going to be +giving the lecture today but George is + + align:start position:0% +giving the lecture today but George is + + + align:start position:0% +giving the lecture today but George is +here so if You' got questions you can + + align:start position:0% +here so if You' got questions you can + + + align:start position:0% +here so if You' got questions you can +ask ask me I don't mind it being + + align:start position:0% +ask ask me I don't mind it being + + + align:start position:0% +ask ask me I don't mind it being +interrupted at any time but also uh if + + align:start position:0% +interrupted at any time but also uh if + + + align:start position:0% +interrupted at any time but also uh if +if you want George to answer something + + align:start position:0% +if you want George to answer something + + + align:start position:0% +if you want George to answer something +he's sitting here as well so he can also + + align:start position:0% +he's sitting here as well so he can also + + + align:start position:0% +he's sitting here as well so he can also +contribute uh so uh last time uh George + + align:start position:0% +contribute uh so uh last time uh George + + + align:start position:0% +contribute uh so uh last time uh George +was uh looking at the fer transforming + + align:start position:0% +was uh looking at the fer transforming + + + align:start position:0% +was uh looking at the fer transforming +property of a + + align:start position:0% +property of a + + + align:start position:0% +property of a +lens uh and he he he looked at the + + align:start position:0% +lens uh and he he he looked at the + + + align:start position:0% +lens uh and he he he looked at the +derived the 1D case uh where you've just + + align:start position:0% +derived the 1D case uh where you've just + + + align:start position:0% +derived the 1D case uh where you've just +got a function of X rather than a + + align:start position:0% +got a function of X rather than a + + + align:start position:0% +got a function of X rather than a +function of XY uh you've got this + + align:start position:0% +function of XY uh you've got this + + + align:start position:0% +function of XY uh you've got this +transparency a distance Z in front of + + align:start position:0% +transparency a distance Z in front of + + + align:start position:0% +transparency a distance Z in front of +the + + align:start position:0% +the + + + align:start position:0% +the +lens uh and and then you've got a a + + align:start position:0% +lens uh and and then you've got a a + + + align:start position:0% +lens uh and and then you've got a a +screen placed a distance F behind the + + align:start position:0% +screen placed a distance F behind the + + + align:start position:0% +screen placed a distance F behind the +lens and so the question is what do you + + align:start position:0% +lens and so the question is what do you + + + align:start position:0% +lens and so the question is what do you +get on that screen uh and uh what I'm + + align:start position:0% +get on that screen uh and uh what I'm + + + align:start position:0% +get on that screen uh and uh what I'm +not going to go through all the algebra + + align:start position:0% +not going to go through all the algebra + + + align:start position:0% +not going to go through all the algebra +of that again because George did it last + + align:start position:0% +of that again because George did it last + + + align:start position:0% +of that again because George did it last +time this was the Cal this this was the + + align:start position:0% +time this was the Cal this this was the + + + align:start position:0% +time this was the Cal this this was the +answer what you find uh is that uh you + + align:start position:0% +answer what you find uh is that uh you + + + align:start position:0% +answer what you find uh is that uh you +what you get in in this plane here is + + align:start position:0% +what you get in in this plane here is + + + align:start position:0% +what you get in in this plane here is +actually the fer + + align:start position:0% +actually the fer + + + align:start position:0% +actually the fer +transform of the uh thin + + align:start position:0% +transform of the uh thin + + + align:start position:0% +transform of the uh thin +transparency right so G of X is this + + align:start position:0% +transparency right so G of X is this + + + align:start position:0% +transparency right so G of X is this +transparency here you get the fer + + align:start position:0% +transparency here you get the fer + + + align:start position:0% +transparency here you get the fer +transform of + + align:start position:0% +transform of + + + align:start position:0% +transform of +that uh + + align:start position:0% +that uh + + + align:start position:0% +that uh +and multiplied uh by a a parabolic phase + + align:start position:0% +and multiplied uh by a a parabolic phase + + + align:start position:0% +and multiplied uh by a a parabolic phase +Factor uh which depends on the position + + align:start position:0% +Factor uh which depends on the position + + + align:start position:0% +Factor uh which depends on the position +of this screen what the of the uh of the + + align:start position:0% +of this screen what the of the uh of the + + + align:start position:0% +of this screen what the of the uh of the +transparency + + align:start position:0% +transparency + + + align:start position:0% +transparency +what is the value of this Zed you'll + + align:start position:0% +what is the value of this Zed you'll + + + align:start position:0% +what is the value of this Zed you'll +notice that you get this uh Factor here + + align:start position:0% +notice that you get this uh Factor here + + + align:start position:0% +notice that you get this uh Factor here +1 - z/ F uh so if Z equals F uh this is + + align:start position:0% +1 - z/ F uh so if Z equals F uh this is + + + align:start position:0% +1 - z/ F uh so if Z equals F uh this is +going to be zero and this phase factor + + align:start position:0% +going to be zero and this phase factor + + + align:start position:0% +going to be zero and this phase factor +is going to disappear so for the special + + align:start position:0% +is going to disappear so for the special + + + align:start position:0% +is going to disappear so for the special +case where Z equals + + align:start position:0% +case where Z equals + + + align:start position:0% +case where Z equals +F all you see here is just the fer + + align:start position:0% +F all you see here is just the fer + + + align:start position:0% +F all you see here is just the fer +transform of this very simple very + + align:start position:0% +transform of this very simple very + + + align:start position:0% +transform of this very simple very +simple answer uh and um people actually + + align:start position:0% +simple answer uh and um people actually + + + align:start position:0% +simple answer uh and um people actually +have known this for quite a long time + + align:start position:0% +have known this for quite a long time + + + align:start position:0% +have known this for quite a long time +and at one time it did look really + + align:start position:0% +and at one time it did look really + + + align:start position:0% +and at one time it did look really +attractive that you could actually + + align:start position:0% +attractive that you could actually + + + align:start position:0% +attractive that you could actually +imagine using this as a real way of + + align:start position:0% +imagine using this as a real way of + + + align:start position:0% +imagine using this as a real way of +doing uh forer transforms uh especially + + align:start position:0% +doing uh forer transforms uh especially + + + align:start position:0% +doing uh forer transforms uh especially +as uh as we're now going to do you can + + align:start position:0% +as uh as we're now going to do you can + + + align:start position:0% +as uh as we're now going to do you can +immediately generalize that to the 2D + + align:start position:0% +immediately generalize that to the 2D + + + align:start position:0% +immediately generalize that to the 2D +case uh so you can do a 2d forer + + align:start position:0% +case uh so you can do a 2d forer + + + align:start position:0% +case uh so you can do a 2d forer +transform uh and when you think that um + + align:start position:0% +transform uh and when you think that um + + + align:start position:0% +transform uh and when you think that um +you know the the light propagates + + align:start position:0% +you know the the light propagates + + + align:start position:0% +you know the the light propagates +through this at the speed of light you + + align:start position:0% +through this at the speed of light you + + + align:start position:0% +through this at the speed of light you +can do a 2d forer transform at the speed + + align:start position:0% +can do a 2d forer transform at the speed + + + align:start position:0% +can do a 2d forer transform at the speed +of light uh and when people first + + align:start position:0% +of light uh and when people first + + + align:start position:0% +of light uh and when people first +realized this which was back in the + + align:start position:0% +realized this which was back in the + + + align:start position:0% +realized this which was back in the +1950s 50s or early + + align:start position:0% +1950s 50s or early + + + align:start position:0% +1950s 50s or early +60s uh you know computers were very slow + + align:start position:0% +60s uh you know computers were very slow + + + align:start position:0% +60s uh you know computers were very slow +then so doing a 2d forer transform was + + align:start position:0% +then so doing a 2d forer transform was + + + align:start position:0% +then so doing a 2d forer transform was +not trivial uh so a lot of effort was + + align:start position:0% +not trivial uh so a lot of effort was + + + align:start position:0% +not trivial uh so a lot of effort was +put into trying to design instruments to + + align:start position:0% +put into trying to design instruments to + + + align:start position:0% +put into trying to design instruments to +do that yes sure do you know who was the + + align:start position:0% +do that yes sure do you know who was the + + + align:start position:0% +do that yes sure do you know who was the +first one to realize this was it VL or + + align:start position:0% +first one to realize this was it VL or + + + align:start position:0% +first one to realize this was it VL or +uh uh the question is who was the first + + align:start position:0% +uh uh the question is who was the first + + + align:start position:0% +uh uh the question is who was the first +to recognize that yeah Vander Lutz well + + align:start position:0% +to recognize that yeah Vander Lutz well + + + align:start position:0% +to recognize that yeah Vander Lutz well +Vander Lutz was at um uh he was at + + align:start position:0% +Vander Lutz was at um uh he was at + + + align:start position:0% +Vander Lutz was at um uh he was at +Michigan wasn't he and an interestingly + + align:start position:0% +Michigan wasn't he and an interestingly + + + align:start position:0% +Michigan wasn't he and an interestingly +the um the holography guys were also in + + align:start position:0% +the um the holography guys were also in + + + align:start position:0% +the um the holography guys were also in +the same lab um what's the guy's name + + align:start position:0% +the same lab um what's the guy's name + + + align:start position:0% +the same lab um what's the guy's name +the one that em EMT Le uh and + + align:start position:0% +the one that em EMT Le uh and + + + align:start position:0% +the one that em EMT Le uh and +interestingly EMT LEF and Van + + align:start position:0% +interestingly EMT LEF and Van + + + align:start position:0% +interestingly EMT LEF and Van +delut uh both published virtually the + + align:start position:0% +delut uh both published virtually the + + + align:start position:0% +delut uh both published virtually the +same paper in the same year uh it's a + + align:start position:0% +same paper in the same year uh it's a + + + align:start position:0% +same paper in the same year uh it's a +very very interesting historical thing + + align:start position:0% +very very interesting historical thing + + + align:start position:0% +very very interesting historical thing +there they're both from the same lab and + + align:start position:0% +there they're both from the same lab and + + + align:start position:0% +there they're both from the same lab and +both invented almost the same idea as + + align:start position:0% +both invented almost the same idea as + + + align:start position:0% +both invented almost the same idea as +far as I can see uh and neither of them + + align:start position:0% +far as I can see uh and neither of them + + + align:start position:0% +far as I can see uh and neither of them +refer to the other guy very + + align:start position:0% +refer to the other guy very + + + align:start position:0% +refer to the other guy very +peculiar anyway um I don't know who + + align:start position:0% +peculiar anyway um I don't know who + + + align:start position:0% +peculiar anyway um I don't know who +really came up with this idea first but + + align:start position:0% +really came up with this idea first but + + + align:start position:0% +really came up with this idea first but +um but actually I think the I suspect + + align:start position:0% +um but actually I think the I suspect + + + align:start position:0% +um but actually I think the I suspect +that actually even uh an ABBA re + + align:start position:0% +that actually even uh an ABBA re + + + align:start position:0% +that actually even uh an ABBA re +realized this you know he uh an an daber + + align:start position:0% +realized this you know he uh an an daber + + + align:start position:0% +realized this you know he uh an an daber +was the + + align:start position:0% +was the + + + align:start position:0% +was the +scientist uh who designed the Zeiss + + align:start position:0% +scientist uh who designed the Zeiss + + + align:start position:0% +scientist uh who designed the Zeiss +microscopes + + align:start position:0% +microscopes + + + align:start position:0% +microscopes +uh 120 130 years ago and uh and and he + + align:start position:0% +uh 120 130 years ago and uh and and he + + + align:start position:0% +uh 120 130 years ago and uh and and he +came up with a theory for image + + align:start position:0% +came up with a theory for image + + + align:start position:0% +came up with a theory for image +formation and a microscope which is + + align:start position:0% +formation and a microscope which is + + + align:start position:0% +formation and a microscope which is +actually what we're going to be getting + + align:start position:0% +actually what we're going to be getting + + + align:start position:0% +actually what we're going to be getting +on to pretty well the next thing the um + + align:start position:0% +on to pretty well the next thing the um + + + align:start position:0% +on to pretty well the next thing the um +Imaging with a 4f system uh he he + + align:start position:0% +Imaging with a 4f system uh he he + + + align:start position:0% +Imaging with a 4f system uh he he +understood that 130 years ago uh and I + + align:start position:0% +understood that 130 years ago uh and I + + + align:start position:0% +understood that 130 years ago uh and I +don't think he's often given as much + + align:start position:0% +don't think he's often given as much + + + align:start position:0% +don't think he's often given as much +credit as he should get give anyway you + + align:start position:0% +credit as he should get give anyway you + + + align:start position:0% +credit as he should get give anyway you +can use this as a way of doing a a fer + + align:start position:0% +can use this as a way of doing a a fer + + + align:start position:0% +can use this as a way of doing a a fer +transform and even a 2d for a transform + + align:start position:0% +transform and even a 2d for a transform + + + align:start position:0% +transform and even a 2d for a transform +so you see going from this stage to this + + align:start position:0% +so you see going from this stage to this + + + align:start position:0% +so you see going from this stage to this +stage is is Trivial really uh all all + + align:start position:0% +stage is is Trivial really uh all all + + + align:start position:0% +stage is is Trivial really uh all all +you've all we've done here is assuming + + align:start position:0% +you've all we've done here is assuming + + + align:start position:0% +you've all we've done here is assuming +that it's a separable function of X and + + align:start position:0% +that it's a separable function of X and + + + align:start position:0% +that it's a separable function of X and +Y so you get exactly the same sort of + + align:start position:0% +Y so you get exactly the same sort of + + + align:start position:0% +Y so you get exactly the same sort of +integral for for y as you get get for X + + align:start position:0% +integral for for y as you get get for X + + + align:start position:0% +integral for for y as you get get for X +so it now becomes a a double integral + + align:start position:0% +so it now becomes a a double integral + + + align:start position:0% +so it now becomes a a double integral +this is a two the two-dimensional forer + + align:start position:0% +this is a two the two-dimensional forer + + + align:start position:0% +this is a two the two-dimensional forer +transform of G of G of + + align:start position:0% +transform of G of G of + + + align:start position:0% +transform of G of G of +XY and uh and you you can see uh you get + + align:start position:0% +XY and uh and you you can see uh you get + + + align:start position:0% +XY and uh and you you can see uh you get +again the phase Factor um here you + + align:start position:0% +again the phase Factor um here you + + + align:start position:0% +again the phase Factor um here you +because it's separable uh you got this e + + align:start position:0% +because it's separable uh you got this e + + + align:start position:0% +because it's separable uh you got this e +e to the I Pi x^2 and you've got an e to + + align:start position:0% +e to the I Pi x^2 and you've got an e to + + + align:start position:0% +e to the I Pi x^2 and you've got an e to +I Pi y^ 2 and of course x^2 + y^2 very + + align:start position:0% +I Pi y^ 2 and of course x^2 + y^2 very + + + align:start position:0% +I Pi y^ 2 and of course x^2 + y^2 very +nicely equals R 2 so this becomes a a a + + align:start position:0% +nicely equals R 2 so this becomes a a a + + + align:start position:0% +nicely equals R 2 so this becomes a a a +a spherical type um + + align:start position:0% +a spherical type um + + + align:start position:0% +a spherical type um +wave so we've still got this 1us Z over + + align:start position:0% +wave so we've still got this 1us Z over + + + align:start position:0% +wave so we've still got this 1us Z over +F so if Z equal f + + align:start position:0% +F so if Z equal f + + + align:start position:0% +F so if Z equal f +uh then again this this phase Factor + + align:start position:0% +uh then again this this phase Factor + + + align:start position:0% +uh then again this this phase Factor +vanishes and we end up with just the the + + align:start position:0% +vanishes and we end up with just the the + + + align:start position:0% +vanishes and we end up with just the the +pure fer + + align:start position:0% +pure fer + + + align:start position:0% +pure fer +transform yeah as I say so a lot of + + align:start position:0% +transform yeah as I say so a lot of + + + align:start position:0% +transform yeah as I say so a lot of +people thought that um this was quite a + + align:start position:0% +people thought that um this was quite a + + + align:start position:0% +people thought that um this was quite a +a neat way of doing fer transforms um + + align:start position:0% +a neat way of doing fer transforms um + + + align:start position:0% +a neat way of doing fer transforms um +there was a lot of work on optical + + align:start position:0% +there was a lot of work on optical + + + align:start position:0% +there was a lot of work on optical +computers all the way through the 60s + + align:start position:0% +computers all the way through the 60s + + + align:start position:0% +computers all the way through the 60s +and + + align:start position:0% +and + + + align:start position:0% +and +70s uh but the the trouble is that as + + align:start position:0% +70s uh but the the trouble is that as + + + align:start position:0% +70s uh but the the trouble is that as +fast as they could develop these systems + + align:start position:0% +fast as they could develop these systems + + + align:start position:0% +fast as they could develop these systems +the computer people + + align:start position:0% +the computer people + + + align:start position:0% +the computer people +develop their computers even faster so + + align:start position:0% +develop their computers even faster so + + + align:start position:0% +develop their computers even faster so +they were always one step behind I think + + align:start position:0% +they were always one step behind I think + + + align:start position:0% +they were always one step behind I think +uh so I think in the end people realized + + align:start position:0% +uh so I think in the end people realized + + + align:start position:0% +uh so I think in the end people realized +it was a waste of time and uh uh and and + + align:start position:0% +it was a waste of time and uh uh and and + + + align:start position:0% +it was a waste of time and uh uh and and +that it was never really going to become + + align:start position:0% +that it was never really going to become + + + align:start position:0% +that it was never really going to become +a uh a a + + align:start position:0% +a uh a a + + + align:start position:0% +a uh a a +um you know a a a practical way of doing + + align:start position:0% +um you know a a a practical way of doing + + + align:start position:0% +um you know a a a practical way of doing +real calculations but in the early days + + align:start position:0% +real calculations but in the early days + + + align:start position:0% +real calculations but in the early days +it was and emit Le we were just + + align:start position:0% +it was and emit Le we were just + + + align:start position:0% +it was and emit Le we were just +mentioning uh he first developed these + + align:start position:0% +mentioning uh he first developed these + + + align:start position:0% +mentioning uh he first developed these +systems for uh actually izing the um uh + + align:start position:0% +systems for uh actually izing the um uh + + + align:start position:0% +systems for uh actually izing the um uh +the images they took from um synthetic + + align:start position:0% +the images they took from um synthetic + + + align:start position:0% +the images they took from um synthetic +aperture they you know an airplane + + align:start position:0% +aperture they you know an airplane + + + align:start position:0% +aperture they you know an airplane +they'd fly an airplane over North + + align:start position:0% +they'd fly an airplane over North + + + align:start position:0% +they'd fly an airplane over North +Korea uh taking + + align:start position:0% +Korea uh taking + + + align:start position:0% +Korea uh taking +pictures uh and then the idea was that + + align:start position:0% +pictures uh and then the idea was that + + + align:start position:0% +pictures uh and then the idea was that +the the the the plane takes many + + align:start position:0% +the the the the plane takes many + + + align:start position:0% +the the the the plane takes many +pictures as it's traveling along uh and + + align:start position:0% +pictures as it's traveling along uh and + + + align:start position:0% +pictures as it's traveling along uh and +they're coherent with the respect to + + align:start position:0% +they're coherent with the respect to + + + align:start position:0% +they're coherent with the respect to +each other so you you can actually + + align:start position:0% +each other so you you can actually + + + align:start position:0% +each other so you you can actually +combine them digitally afterwards and + + align:start position:0% +combine them digitally afterwards and + + + align:start position:0% +combine them digitally afterwards and +get an image which has got amazing + + align:start position:0% +get an image which has got amazing + + + align:start position:0% +get an image which has got amazing +resolution and you can see the guy in + + align:start position:0% +resolution and you can see the guy in + + + align:start position:0% +resolution and you can see the guy in +North Korea reading his newspaper or + + align:start position:0% +North Korea reading his newspaper or + + + align:start position:0% +North Korea reading his newspaper or +whatever so they they really did that + + align:start position:0% +whatever so they they really did that + + + align:start position:0% +whatever so they they really did that +sort of thing way back then right so so + + align:start position:0% +sort of thing way back then right so so + + + align:start position:0% +sort of thing way back then right so so +that's the uh equation here then uh and + + align:start position:0% +that's the uh equation here then uh and + + + align:start position:0% +that's the uh equation here then uh and +um yeah so this is just going through + + align:start position:0% +um yeah so this is just going through + + + align:start position:0% +um yeah so this is just going through +how that thing was derived uh so we've + + align:start position:0% +how that thing was derived uh so we've + + + align:start position:0% +how that thing was derived uh so we've +got this um we've got the screen uh + + align:start position:0% +got this um we've got the screen uh + + + align:start position:0% +got this um we've got the screen uh +we've got the screen here the G of x + + align:start position:0% +we've got the screen here the G of x + + + align:start position:0% +we've got the screen here the G of x +by the time we get here there's a uh + + align:start position:0% +by the time we get here there's a uh + + + align:start position:0% +by the time we get here there's a uh +it's convolved with some phase parabolic + + align:start position:0% +it's convolved with some phase parabolic + + + align:start position:0% +it's convolved with some phase parabolic +phase function uh and then after it goes + + align:start position:0% +phase function uh and then after it goes + + + align:start position:0% +phase function uh and then after it goes +through here it's multiplied by another + + align:start position:0% +through here it's multiplied by another + + + align:start position:0% +through here it's multiplied by another +parabolic phase function and then as it + + align:start position:0% +parabolic phase function and then as it + + + align:start position:0% +parabolic phase function and then as it +propagates here it's convolved with + + align:start position:0% +propagates here it's convolved with + + + align:start position:0% +propagates here it's convolved with +another parabolic phase function uh and + + align:start position:0% +another parabolic phase function uh and + + + align:start position:0% +another parabolic phase function uh and +if we have that magic condition that + + align:start position:0% +if we have that magic condition that + + + align:start position:0% +if we have that magic condition that +this is f and this is f most of these + + align:start position:0% +this is f and this is f most of these + + + align:start position:0% +this is f and this is f most of these +parabolic phases cancel out and we're + + align:start position:0% +parabolic phases cancel out and we're + + + align:start position:0% +parabolic phases cancel out and we're +left with this very simple final answer + + align:start position:0% +left with this very simple final answer + + + align:start position:0% +left with this very simple final answer +so that's basically what's happening and + + align:start position:0% +so that's basically what's happening and + + + align:start position:0% +so that's basically what's happening and +George went through you know the the + + align:start position:0% +George went through you know the the + + + align:start position:0% +George went through you know the the +various stages of doing this of course + + align:start position:0% +various stages of doing this of course + + + align:start position:0% +various stages of doing this of course +you end up with a couple of integrals of + + align:start position:0% +you end up with a couple of integrals of + + + align:start position:0% +you end up with a couple of integrals of +of products of three phase functions + + align:start position:0% +of products of three phase functions + + + align:start position:0% +of products of three phase functions +here so uh the algebra was was quite um + + align:start position:0% +here so uh the algebra was was quite um + + + align:start position:0% +here so uh the algebra was was quite um +complicated well not really complicated + + align:start position:0% +complicated well not really complicated + + + align:start position:0% +complicated well not really complicated +but just lengthy uh and uh but but + + align:start position:0% +but just lengthy uh and uh but but + + + align:start position:0% +but just lengthy uh and uh but but +everything in the end + + align:start position:0% +everything in the end + + + align:start position:0% +everything in the end +cancels if you haven't got Z equals to F + + align:start position:0% +cancels if you haven't got Z equals to F + + + align:start position:0% +cancels if you haven't got Z equals to F +though uh then you can see uh that um + + align:start position:0% +though uh then you can see uh that um + + + align:start position:0% +though uh then you can see uh that um +you you do got got you have got this + + align:start position:0% +you you do got got you have got this + + + align:start position:0% +you you do got got you have got this +phase Factor so you don't actually get + + align:start position:0% +phase Factor so you don't actually get + + + align:start position:0% +phase Factor so you don't actually get +exactly the fuer transform in this plane + + align:start position:0% +exactly the fuer transform in this plane + + + align:start position:0% +exactly the fuer transform in this plane +in that case you get the fuer transform + + align:start position:0% +in that case you get the fuer transform + + + align:start position:0% +in that case you get the fuer transform +multiplied by this phase Factor uh and + + align:start position:0% +multiplied by this phase Factor uh and + + + align:start position:0% +multiplied by this phase Factor uh and +uh that can be important in some cases + + align:start position:0% +uh that can be important in some cases + + + align:start position:0% +uh that can be important in some cases +that's something that you need to take + + align:start position:0% +that's something that you need to take + + + align:start position:0% +that's something that you need to take +into account um there's another special + + align:start position:0% +into account um there's another special + + + align:start position:0% +into account um there's another special +case actually uh that's the case when Z + + align:start position:0% +case actually uh that's the case when Z + + + align:start position:0% +case actually uh that's the case when Z +equals not + + align:start position:0% +equals not + + + align:start position:0% +equals not +uh the case when Z equals not is if this + + align:start position:0% +uh the case when Z equals not is if this + + + align:start position:0% +uh the case when Z equals not is if this +screen coincides with the lens + + align:start position:0% +screen coincides with the lens + + + align:start position:0% +screen coincides with the lens +immediately close up to the lens uh and + + align:start position:0% +immediately close up to the lens uh and + + + align:start position:0% +immediately close up to the lens uh and +I think Goodman does that that one as + + align:start position:0% +I think Goodman does that that one as + + + align:start position:0% +I think Goodman does that that one as +well doesn't he uh and so if Z equals n + + align:start position:0% +well doesn't he uh and so if Z equals n + + + align:start position:0% +well doesn't he uh and so if Z equals n +this this goes uh and so we're still + + align:start position:0% +this this goes uh and so we're still + + + align:start position:0% +this this goes uh and so we're still +left with this phase Factor e to the I + + align:start position:0% +left with this phase Factor e to the I + + + align:start position:0% +left with this phase Factor e to the I +Pi X-2 over Lambda F right so and also + + align:start position:0% +Pi X-2 over Lambda F right so and also + + + align:start position:0% +Pi X-2 over Lambda F right so and also +Goodman does the case of the + + align:start position:0% +Goodman does the case of the + + + align:start position:0% +Goodman does the case of the +transparency after the lens which I did + + align:start position:0% +transparency after the lens which I did + + + align:start position:0% +transparency after the lens which I did +not do in the nodes right okay yeah so + + align:start position:0% +not do in the nodes right okay yeah so + + + align:start position:0% +not do in the nodes right okay yeah so +Goodman yeah Goodman does this case of + + align:start position:0% +Goodman yeah Goodman does this case of + + + align:start position:0% +Goodman yeah Goodman does this case of +the transparency placed in here that Z + + align:start position:0% +the transparency placed in here that Z + + + align:start position:0% +the transparency placed in here that Z +negative in yeah yeah but it's all it's + + align:start position:0% +negative in yeah yeah but it's all it's + + + align:start position:0% +negative in yeah yeah but it's all it's +very similar sort of + + align:start position:0% + + + + align:start position:0% + +answers okay so + + align:start position:0% +answers okay so + + + align:start position:0% +answers okay so +um yeah so so this is just writing down + + align:start position:0% +um yeah so so this is just writing down + + + align:start position:0% +um yeah so so this is just writing down +finally then uh we're defining then the + + align:start position:0% +finally then uh we're defining then the + + + align:start position:0% +finally then uh we're defining then the +fer transform is called the fer + + align:start position:0% +fer transform is called the fer + + + align:start position:0% +fer transform is called the fer +transform of little G is Big G right so + + align:start position:0% +transform of little G is Big G right so + + + align:start position:0% +transform of little G is Big G right so +the final answer is that you've got this + + align:start position:0% +the final answer is that you've got this + + + align:start position:0% +the final answer is that you've got this +parabolic phase function times the the + + align:start position:0% +parabolic phase function times the the + + + align:start position:0% +parabolic phase function times the the +fer transform of of + + align:start position:0% + + + + align:start position:0% + +G okay so um this is + + align:start position:0% +G okay so um this is + + + align:start position:0% +G okay so um this is +um uh pointing out that we've now looked + + align:start position:0% +um uh pointing out that we've now looked + + + align:start position:0% +um uh pointing out that we've now looked +at two different ways you can do a fer + + align:start position:0% +at two different ways you can do a fer + + + align:start position:0% +at two different ways you can do a fer +transform uh one way uh is to just + + align:start position:0% +transform uh one way uh is to just + + + align:start position:0% +transform uh one way uh is to just +propagate the light a very large + + align:start position:0% +propagate the light a very large + + + align:start position:0% +propagate the light a very large +distance you remember if you have frown + + align:start position:0% +distance you remember if you have frown + + + align:start position:0% +distance you remember if you have frown +off a defraction if your screen is a + + align:start position:0% +off a defraction if your screen is a + + + align:start position:0% +off a defraction if your screen is a +very long way away from the uh from the + + align:start position:0% +very long way away from the uh from the + + + align:start position:0% +very long way away from the uh from the +diffracting screen from the diffracting + + align:start position:0% +diffracting screen from the diffracting + + + align:start position:0% +diffracting screen from the diffracting +scre uh object whatever it was called uh + + align:start position:0% +scre uh object whatever it was called uh + + + align:start position:0% +scre uh object whatever it was called uh +transparency uh then again you get this + + align:start position:0% +transparency uh then again you get this + + + align:start position:0% +transparency uh then again you get this +for a transform relationship but of + + align:start position:0% +for a transform relationship but of + + + align:start position:0% +for a transform relationship but of +course here he's put a proportional sign + + align:start position:0% +course here he's put a proportional sign + + + align:start position:0% +course here he's put a proportional sign +there's some things out the front there + + align:start position:0% +there's some things out the front there + + + align:start position:0% +there's some things out the front there +uh and in particular there's going to be + + align:start position:0% +uh and in particular there's going to be + + + align:start position:0% +uh and in particular there's going to be +a again a parabolic phase term isn't + + align:start position:0% +a again a parabolic phase term isn't + + + align:start position:0% +a again a parabolic phase term isn't +there because in this case here what + + align:start position:0% +there because in this case here what + + + align:start position:0% +there because in this case here what +you'd expect actually is that this forer + + align:start position:0% +you'd expect actually is that this forer + + + align:start position:0% +you'd expect actually is that this forer +transform is going to be actually on the + + align:start position:0% +transform is going to be actually on the + + + align:start position:0% +transform is going to be actually on the +surface of of some curved surface uh not + + align:start position:0% +surface of of some curved surface uh not + + + align:start position:0% +surface of of some curved surface uh not +of a of a plain surface right so if you + + align:start position:0% +of a of a plain surface right so if you + + + align:start position:0% +of a of a plain surface right so if you +put the screen if the screen is plain + + align:start position:0% +put the screen if the screen is plain + + + align:start position:0% +put the screen if the screen is plain +then it's going to be multiplied by some + + align:start position:0% +then it's going to be multiplied by some + + + align:start position:0% +then it's going to be multiplied by some +parabolic phase term uh and now we've + + align:start position:0% +parabolic phase term uh and now we've + + + align:start position:0% +parabolic phase term uh and now we've +just looked at this other case where we + + align:start position:0% +just looked at this other case where we + + + align:start position:0% +just looked at this other case where we +don't have to uh have a very large Lab + + align:start position:0% +don't have to uh have a very large Lab + + + align:start position:0% +don't have to uh have a very large Lab +in order to do this + + align:start position:0% +in order to do this + + + align:start position:0% +in order to do this +experiment uh we can actually make the + + align:start position:0% +experiment uh we can actually make the + + + align:start position:0% +experiment uh we can actually make the +experiment quite small so that it fits + + align:start position:0% +experiment quite small so that it fits + + + align:start position:0% +experiment quite small so that it fits +on top of the table just by using a lens + + align:start position:0% +on top of the table just by using a lens + + + align:start position:0% +on top of the table just by using a lens +uh and you know really what you can see + + align:start position:0% +uh and you know really what you can see + + + align:start position:0% +uh and you know really what you can see +that that is actually doing according to + + align:start position:0% +that that is actually doing according to + + + align:start position:0% +that that is actually doing according to +your geometrical Optics ideas now you + + align:start position:0% +your geometrical Optics ideas now you + + + align:start position:0% +your geometrical Optics ideas now you +can see what this is doing uh this is + + align:start position:0% +can see what this is doing uh this is + + + align:start position:0% +can see what this is doing uh this is +producing an image of this at Infinity + + align:start position:0% +producing an image of this at Infinity + + + align:start position:0% +producing an image of this at Infinity +so you can see that the these these two + + align:start position:0% +so you can see that the these these two + + + align:start position:0% +so you can see that the these these two +things are actually equivalent what it's + + align:start position:0% +things are actually equivalent what it's + + + align:start position:0% +things are actually equivalent what it's +doing is bringing what would have been + + align:start position:0% +doing is bringing what would have been + + + align:start position:0% +doing is bringing what would have been +at Infinity uh to some finite plane + + align:start position:0% +at Infinity uh to some finite plane + + + align:start position:0% +at Infinity uh to some finite plane +isn't it right so that's that's that's + + align:start position:0% +isn't it right so that's that's that's + + + align:start position:0% +isn't it right so that's that's that's +all it's doing there uh but again we've + + align:start position:0% +all it's doing there uh but again we've + + + align:start position:0% +all it's doing there uh but again we've +got this uh this thing + + align:start position:0% +got this uh this thing + + + align:start position:0% +got this uh this thing +here uh this uh proportional sign which + + align:start position:0% +here uh this uh proportional sign which + + + align:start position:0% +here uh this uh proportional sign which +means there's some some other factors + + align:start position:0% +means there's some some other factors + + + align:start position:0% +means there's some some other factors +constant factors out there including in + + align:start position:0% +constant factors out there including in + + + align:start position:0% +constant factors out there including in +general uh a uh this parabolic phase + + align:start position:0% +general uh a uh this parabolic phase + + + align:start position:0% +general uh a uh this parabolic phase +factor which for the particular case + + align:start position:0% +factor which for the particular case + + + align:start position:0% +factor which for the particular case +when you got F and + + align:start position:0% +when you got F and + + + align:start position:0% +when you got F and +F + + align:start position:0% +F + + + align:start position:0% +F +uh disappears The parabolic Phase + + align:start position:0% +uh disappears The parabolic Phase + + + align:start position:0% +uh disappears The parabolic Phase +function disappears when you've got this + + align:start position:0% +function disappears when you've got this + + + align:start position:0% +function disappears when you've got this +uh special very very special case with + + align:start position:0% +uh special very very special case with + + + align:start position:0% +uh special very very special case with +the two FS + + align:start position:0% + + + + align:start position:0% + +there okay now this one um what this is + + align:start position:0% +there okay now this one um what this is + + + align:start position:0% +there okay now this one um what this is +really trying to show is that really + + align:start position:0% +really trying to show is that really + + + align:start position:0% +really trying to show is that really +there's two ways of looking at this + + align:start position:0% +there's two ways of looking at this + + + align:start position:0% +there's two ways of looking at this +problem uh you can uh what these two + + align:start position:0% +problem uh you can uh what these two + + + align:start position:0% +problem uh you can uh what these two +diagrams here are really trying to show + + align:start position:0% +diagrams here are really trying to show + + + align:start position:0% +diagrams here are really trying to show +uh there's it's trying to show the same + + align:start position:0% +uh there's it's trying to show the same + + + align:start position:0% +uh there's it's trying to show the same +case but trying to get you thinking + + align:start position:0% +case but trying to get you thinking + + + align:start position:0% +case but trying to get you thinking +about a different way of of of um + + align:start position:0% +about a different way of of of um + + + align:start position:0% +about a different way of of of um +viewing the problem so in this case here + + align:start position:0% +viewing the problem so in this case here + + + align:start position:0% +viewing the problem so in this case here +uh you can think of any point on the + + align:start position:0% +uh you can think of any point on the + + + align:start position:0% +uh you can think of any point on the +screen on the on the the um uh what does + + align:start position:0% +screen on the on the the um uh what does + + + align:start position:0% +screen on the on the the um uh what does +he call it + + align:start position:0% +he call it + + + align:start position:0% +he call it +transparency uh is going to act like a + + align:start position:0% +transparency uh is going to act like a + + + align:start position:0% +transparency uh is going to act like a +point + + align:start position:0% +point + + + align:start position:0% +point +source uh so it's going to produce a + + align:start position:0% +source uh so it's going to produce a + + + align:start position:0% +source uh so it's going to produce a +spherical expanding wave uh and then + + align:start position:0% +spherical expanding wave uh and then + + + align:start position:0% +spherical expanding wave uh and then +this is a distance F so that spherical + + align:start position:0% +this is a distance F so that spherical + + + align:start position:0% +this is a distance F so that spherical +wave is going to be converted into a + + align:start position:0% +wave is going to be converted into a + + + align:start position:0% +wave is going to be converted into a +plane wave uh the angle of propagation + + align:start position:0% +plane wave uh the angle of propagation + + + align:start position:0% +plane wave uh the angle of propagation +of this plane wave depends on the + + align:start position:0% +of this plane wave depends on the + + + align:start position:0% +of this plane wave depends on the +distance at this point from the orig + + align:start position:0% +distance at this point from the orig + + + align:start position:0% +distance at this point from the orig +from the origin of course right uh and + + align:start position:0% +from the origin of course right uh and + + + align:start position:0% +from the origin of course right uh and +uh so you can think then of what you see + + align:start position:0% +uh so you can think then of what you see + + + align:start position:0% +uh so you can think then of what you see +on the screen as being made up of an + + align:start position:0% +on the screen as being made up of an + + + align:start position:0% +on the screen as being made up of an +angular Spectrum what's called an + + align:start position:0% +angular Spectrum what's called an + + + align:start position:0% +angular Spectrum what's called an +angular spectrum of plain waves + + align:start position:0% +angular spectrum of plain waves + + + align:start position:0% +angular spectrum of plain waves +uh where the strength of each of those + + align:start position:0% +uh where the strength of each of those + + + align:start position:0% +uh where the strength of each of those +angular Spectrum components uh comes + + align:start position:0% +angular Spectrum components uh comes + + + align:start position:0% +angular Spectrum components uh comes +about from the value of g at that point + + align:start position:0% +about from the value of g at that point + + + align:start position:0% +about from the value of g at that point +right so uh so that's one way of + + align:start position:0% +right so uh so that's one way of + + + align:start position:0% +right so uh so that's one way of +thinking about it uh and this way is + + align:start position:0% +thinking about it uh and this way is + + + align:start position:0% +thinking about it uh and this way is +thinking about it the other way this way + + align:start position:0% +thinking about it the other way this way + + + align:start position:0% +thinking about it the other way this way +you're thinking of the object is going + + align:start position:0% +you're thinking of the object is going + + + align:start position:0% +you're thinking of the object is going +to Def if you imagine your uh + + align:start position:0% +to Def if you imagine your uh + + + align:start position:0% +to Def if you imagine your uh +transparency as being like a gring it + + align:start position:0% +transparency as being like a gring it + + + align:start position:0% +transparency as being like a gring it +produces uh + + align:start position:0% +produces uh + + + align:start position:0% +produces uh +defraction uh it produces like grating + + align:start position:0% +defraction uh it produces like grating + + + align:start position:0% +defraction uh it produces like grating +orders for example if this this was a + + align:start position:0% +orders for example if this this was a + + + align:start position:0% +orders for example if this this was a +very simple case of a of a sinusoidal + + align:start position:0% +very simple case of a of a sinusoidal + + + align:start position:0% +very simple case of a of a sinusoidal +grating you'd expect it to produce some + + align:start position:0% +grating you'd expect it to produce some + + + align:start position:0% +grating you'd expect it to produce some +grating orders uh and these grating + + align:start position:0% +grating orders uh and these grating + + + align:start position:0% +grating orders uh and these grating +orders correspond to plane waves + + align:start position:0% +orders correspond to plane waves + + + align:start position:0% +orders correspond to plane waves +traveling in particular angles so this + + align:start position:0% +traveling in particular angles so this + + + align:start position:0% +traveling in particular angles so this +shows uh the angular spectrum of the + + align:start position:0% +shows uh the angular spectrum of the + + + align:start position:0% +shows uh the angular spectrum of the +defraction of the light uh given by uh + + align:start position:0% +defraction of the light uh given by uh + + + align:start position:0% +defraction of the light uh given by uh +the uh + + align:start position:0% +the uh + + + align:start position:0% +the uh +transparency and then the lens collects + + align:start position:0% +transparency and then the lens collects + + + align:start position:0% +transparency and then the lens collects +these uh the uh the different um these + + align:start position:0% +these uh the uh the different um these + + + align:start position:0% +these uh the uh the different um these +different plane wave components all of + + align:start position:0% +different plane wave components all of + + + align:start position:0% +different plane wave components all of +them are going to be converted uh into a + + align:start position:0% +them are going to be converted uh into a + + + align:start position:0% +them are going to be converted uh into a +spherical converging wave uh that + + align:start position:0% +spherical converging wave uh that + + + align:start position:0% +spherical converging wave uh that +converges a distance F away it doesn't + + align:start position:0% +converges a distance F away it doesn't + + + align:start position:0% +converges a distance F away it doesn't +say F but it this must be F uh and + + align:start position:0% +say F but it this must be F uh and + + + align:start position:0% +say F but it this must be F uh and +different the plane waves moving at + + align:start position:0% +different the plane waves moving at + + + align:start position:0% +different the plane waves moving at +different angles are going to converge + + align:start position:0% +different angles are going to converge + + + align:start position:0% +different angles are going to converge +to a point + + align:start position:0% +to a point + + + align:start position:0% +to a point +which of course is proportional to the + + align:start position:0% +which of course is proportional to the + + + align:start position:0% +which of course is proportional to the +uh the the sign of the angle of the + + align:start position:0% +uh the the sign of the angle of the + + + align:start position:0% +uh the the sign of the angle of the +propagation right so here at any point + + align:start position:0% +propagation right so here at any point + + + align:start position:0% +propagation right so here at any point +on the screen uh you're you're going to + + align:start position:0% +on the screen uh you're you're going to + + + align:start position:0% +on the screen uh you're you're going to +sum up these again these angular Spectra + + align:start position:0% +sum up these again these angular Spectra + + + align:start position:0% +sum up these again these angular Spectra +components Each of which is going to + + align:start position:0% +components Each of which is going to + + + align:start position:0% +components Each of which is going to +give a spherical weight uh so um you can + + align:start position:0% +give a spherical weight uh so um you can + + + align:start position:0% +give a spherical weight uh so um you can +see looking at that diagram again + + align:start position:0% +see looking at that diagram again + + + align:start position:0% +see looking at that diagram again +they're like sort of inverses of each + + align:start position:0% +they're like sort of inverses of each + + + align:start position:0% +they're like sort of inverses of each +other I think this is another example + + align:start position:0% +other I think this is another example + + + align:start position:0% +other I think this is another example +where uh very often you can think of um + + align:start position:0% +where uh very often you can think of um + + + align:start position:0% +where uh very often you can think of um +uh a reciprocal type + + align:start position:0% +uh a reciprocal type + + + align:start position:0% +uh a reciprocal type +behavior um you know you could yeah you + + align:start position:0% +behavior um you know you could yeah you + + + align:start position:0% +behavior um you know you could yeah you +could you can just flip this over and it + + align:start position:0% +could you can just flip this over and it + + + align:start position:0% +could you can just flip this over and it +it would look the same the other way + + align:start position:0% +it would look the same the other way + + + align:start position:0% +it would look the same the other way +wouldn't + + align:start position:0% +wouldn't + + + align:start position:0% +wouldn't +it okay so so this way here then we're + + align:start position:0% +it okay so so this way here then we're + + + align:start position:0% +it okay so so this way here then we're +thinking this this um here we're + + align:start position:0% +thinking this this um here we're + + + align:start position:0% +thinking this this um here we're +thinking of this as as um just like the + + align:start position:0% +thinking of this as as um just like the + + + align:start position:0% +thinking of this as as um just like the +hyan uh uh sense that we spoke about + + align:start position:0% +hyan uh uh sense that we spoke about + + + align:start position:0% +hyan uh uh sense that we spoke about +when we were first doing defraction then + + align:start position:0% + + + + align:start position:0% + +okay so um this is giving some nice + + align:start position:0% +okay so um this is giving some nice + + + align:start position:0% +okay so um this is giving some nice +pictures I'm going to I'm going to steal + + align:start position:0% +pictures I'm going to I'm going to steal + + + align:start position:0% +pictures I'm going to I'm going to steal +this um presentation afterwards because + + align:start position:0% +this um presentation afterwards because + + + align:start position:0% +this um presentation afterwards because +there's so many good displays in this + + align:start position:0% +there's so many good displays in this + + + align:start position:0% +there's so many good displays in this +thing that I'm going to use in my own + + align:start position:0% +thing that I'm going to use in my own + + + align:start position:0% +thing that I'm going to use in my own +lectures in the future uh so uh so this + + align:start position:0% +lectures in the future uh so uh so this + + + align:start position:0% +lectures in the future uh so uh so this +is giving some good ideas the uh so we + + align:start position:0% +is giving some good ideas the uh so we + + + align:start position:0% +is giving some good ideas the uh so we +start off then uh this is a a rectangle + + align:start position:0% +start off then uh this is a a rectangle + + + align:start position:0% +start off then uh this is a a rectangle +uh oh I'm I'm I'm going to say something + + align:start position:0% +uh oh I'm I'm I'm going to say something + + + align:start position:0% +uh oh I'm I'm I'm going to say something +in a minute though uh the so this is a + + align:start position:0% +in a minute though uh the so this is a + + + align:start position:0% +in a minute though uh the so this is a +distance F this is a distance F uh so + + align:start position:0% +distance F this is a distance F uh so + + + align:start position:0% +distance F this is a distance F uh so +this lens then as we just described is + + align:start position:0% +this lens then as we just described is + + + align:start position:0% +this lens then as we just described is +going to produce a fer transform of that + + align:start position:0% +going to produce a fer transform of that + + + align:start position:0% +going to produce a fer transform of that +so the fer transform of a of a of a rect + + align:start position:0% +so the fer transform of a of a of a rect + + + align:start position:0% +so the fer transform of a of a of a rect +is a is a sync so you'd expect to get + + align:start position:0% +is a is a sync so you'd expect to get + + + align:start position:0% +is a is a sync so you'd expect to get +this a syn in x syn in x times a syn in + + align:start position:0% +this a syn in x syn in x times a syn in + + + align:start position:0% +this a syn in x syn in x times a syn in +y uh now the thing I was going to say + + align:start position:0% +y uh now the thing I was going to say + + + align:start position:0% +y uh now the thing I was going to say +though George this looks to me that this + + align:start position:0% +though George this looks to me that this + + + align:start position:0% +though George this looks to me that this +is longer than that this is longer this + + align:start position:0% +is longer than that this is longer this + + + align:start position:0% +is longer than that this is longer this +way than that way so this should be + + align:start position:0% +way than that way so this should be + + + align:start position:0% +way than that way so this should be +longer that way than this way I think + + align:start position:0% +longer that way than this way I think + + + align:start position:0% +longer that way than this way I think +you know that's the aspect ratio of the + + align:start position:0% +you know that's the aspect ratio of the + + + align:start position:0% +you know that's the aspect ratio of the +screen actually yeah the aspect ratio of + + align:start position:0% +screen actually yeah the aspect ratio of + + + align:start position:0% +screen actually yeah the aspect ratio of +the screen ought to be 90 does not obey + + align:start position:0% +the screen ought to be 90 does not obey + + + align:start position:0% +the screen ought to be 90 does not obey +the full transform gu anyway so but this + + align:start position:0% +the full transform gu anyway so but this + + + align:start position:0% +the full transform gu anyway so but this +conversation is um uh bringing home I + + align:start position:0% +conversation is um uh bringing home I + + + align:start position:0% +conversation is um uh bringing home I +think uh a very important point that + + align:start position:0% +think uh a very important point that + + + align:start position:0% +think uh a very important point that +you've that we've mentioned before in + + align:start position:0% +you've that we've mentioned before in + + + align:start position:0% +you've that we've mentioned before in +the course uh that if you if you make a + + align:start position:0% +the course uh that if you if you make a + + + align:start position:0% +the course uh that if you if you make a +function smaller it's for a transform is + + align:start position:0% +function smaller it's for a transform is + + + align:start position:0% +function smaller it's for a transform is +wider if you if you make the function + + align:start position:0% +wider if you if you make the function + + + align:start position:0% +wider if you if you make the function +wider it foror transform is smaller + + align:start position:0% +wider it foror transform is smaller + + + align:start position:0% +wider it foror transform is smaller +right so uh and you'll notice then this + + align:start position:0% +right so uh and you'll notice then this + + + align:start position:0% +right so uh and you'll notice then this +product of these two sinks gives uh a + + align:start position:0% +product of these two sinks gives uh a + + + align:start position:0% +product of these two sinks gives uh a +bright spot in the center a series of + + align:start position:0% +bright spot in the center a series of + + + align:start position:0% +bright spot in the center a series of +bright spots along the the the axes uh + + align:start position:0% +bright spots along the the the axes uh + + + align:start position:0% +bright spots along the the the axes uh +there are also some bright spots in this + + align:start position:0% +there are also some bright spots in this + + + align:start position:0% +there are also some bright spots in this +region here uh but they're so weak that + + align:start position:0% +region here uh but they're so weak that + + + align:start position:0% +region here uh but they're so weak that +you can't actually see them you really + + align:start position:0% +you can't actually see them you really + + + align:start position:0% +you can't actually see them you really +you can only see the ones along the + + align:start position:0% +you can only see the ones along the + + + align:start position:0% +you can only see the ones along the +axes uh so that's the first example uh + + align:start position:0% +axes uh so that's the first example uh + + + align:start position:0% +axes uh so that's the first example uh +then this one's showing how if we make + + align:start position:0% +then this one's showing how if we make + + + align:start position:0% +then this one's showing how if we make +the uh if we make the transparency + + align:start position:0% +the uh if we make the transparency + + + align:start position:0% +the uh if we make the transparency +smaller the rectangle smaller so this + + align:start position:0% +smaller the rectangle smaller so this + + + align:start position:0% +smaller the rectangle smaller so this +pattern gets + + align:start position:0% +pattern gets + + + align:start position:0% +pattern gets +bigger uh now actually we can just about + + align:start position:0% +bigger uh now actually we can just about + + + align:start position:0% +bigger uh now actually we can just about +manage to maybe see some ones other than + + align:start position:0% +manage to maybe see some ones other than + + + align:start position:0% +manage to maybe see some ones other than +along the axis uh and then this one is + + align:start position:0% +along the axis uh and then this one is + + + align:start position:0% +along the axis uh and then this one is +an interesting one um so now we've got + + align:start position:0% +an interesting one um so now we've got + + + align:start position:0% +an interesting one um so now we've got +not just one + + align:start position:0% +not just one + + + align:start position:0% +not just one +aperture but three + + align:start position:0% +aperture but three + + + align:start position:0% +aperture but three +apertures uh and uh so so so now how can + + align:start position:0% +apertures uh and uh so so so now how can + + + align:start position:0% +apertures uh and uh so so so now how can +we work out what what the the fer + + align:start position:0% +we work out what what the the fer + + + align:start position:0% +we work out what what the the fer +transform of of three apertures would be + + align:start position:0% +transform of of three apertures would be + + + align:start position:0% +transform of of three apertures would be +anyone got some ideas I'm sure Shin will + + align:start position:0% +anyone got some ideas I'm sure Shin will + + + align:start position:0% +anyone got some ideas I'm sure Shin will +have an idea um anyone any how would + + align:start position:0% +have an idea um anyone any how would + + + align:start position:0% +have an idea um anyone any how would +anyone think of of doing this sort of + + align:start position:0% + + + + align:start position:0% + +thing have you come across a thing + + align:start position:0% +thing have you come across a thing + + + align:start position:0% +thing have you come across a thing +called the convolution theorem probably + + align:start position:0% +called the convolution theorem probably + + + align:start position:0% +called the convolution theorem probably +you should have done somewhere I would + + align:start position:0% +you should have done somewhere I would + + + align:start position:0% +you should have done somewhere I would +have thought so there's a thing in fua + + align:start position:0% +have thought so there's a thing in fua + + + align:start position:0% +have thought so there's a thing in fua +transforms called the convolution + + align:start position:0% +transforms called the convolution + + + align:start position:0% +transforms called the convolution +theorem uh so this is + + align:start position:0% +theorem uh so this is + + + align:start position:0% +theorem uh so this is +actually uh this is actually like three + + align:start position:0% +actually uh this is actually like three + + + align:start position:0% +actually uh this is actually like three +three spikes convolved with a square + + align:start position:0% +three spikes convolved with a square + + + align:start position:0% +three spikes convolved with a square +which it really means all it means is we + + align:start position:0% +which it really means all it means is we + + + align:start position:0% +which it really means all it means is we +place a square on each of the three SP + + align:start position:0% +place a square on each of the three SP + + + align:start position:0% +place a square on each of the three SP +spikes uh and the convolution + + align:start position:0% +spikes uh and the convolution + + + align:start position:0% +spikes uh and the convolution +theorem uh says that the for a transform + + align:start position:0% +theorem uh says that the for a transform + + + align:start position:0% +theorem uh says that the for a transform +of a convolution is the product of the + + align:start position:0% +of a convolution is the product of the + + + align:start position:0% +of a convolution is the product of the +FIA + + align:start position:0% +FIA + + + align:start position:0% +FIA +transforms so what you'd X is that the + + align:start position:0% +transforms so what you'd X is that the + + + align:start position:0% +transforms so what you'd X is that the +fer transform that you're going to see + + align:start position:0% +fer transform that you're going to see + + + align:start position:0% +fer transform that you're going to see +here is the fer transform of this of the + + align:start position:0% +here is the fer transform of this of the + + + align:start position:0% +here is the fer transform of this of the +rectangle which is + + align:start position:0% +rectangle which is + + + align:start position:0% +rectangle which is +this multiplied by something else uh + + align:start position:0% +this multiplied by something else uh + + + align:start position:0% +this multiplied by something else uh +which is the fer transform of the three + + align:start position:0% +which is the fer transform of the three + + + align:start position:0% +which is the fer transform of the three +spikes and the three spikes uh is like + + align:start position:0% +spikes and the three spikes uh is like + + + align:start position:0% +spikes and the three spikes uh is like +uh a Delta function and a A plus or + + align:start position:0% +uh a Delta function and a A plus or + + + align:start position:0% +uh a Delta function and a A plus or +minus Delta function the the plus or + + align:start position:0% +minus Delta function the the plus or + + + align:start position:0% +minus Delta function the the plus or +minus Delta function together e to the I + + align:start position:0% +minus Delta function together e to the I + + + align:start position:0% +minus Delta function together e to the I +something plus e to Theus I something + + align:start position:0% +something plus e to Theus I something + + + align:start position:0% +something plus e to Theus I something +gives C + + align:start position:0% +gives C + + + align:start position:0% +gives C +and the the the one at the center just + + align:start position:0% +and the the the one at the center just + + + align:start position:0% +and the the the one at the center just +gives a constant so the fua transform of + + align:start position:0% +gives a constant so the fua transform of + + + align:start position:0% +gives a constant so the fua transform of +these three Delta functions is is one + + align:start position:0% +these three Delta functions is is one + + + align:start position:0% +these three Delta functions is is one +plus a a cosine or something like that + + align:start position:0% +plus a a cosine or something like that + + + align:start position:0% +plus a a cosine or something like that +uh and uh so that's what we expect to + + align:start position:0% +uh and uh so that's what we expect to + + + align:start position:0% +uh and uh so that's what we expect to +see then this thing uh this pattern that + + align:start position:0% +see then this thing uh this pattern that + + + align:start position:0% +see then this thing uh this pattern that +we saw before is going to be multiplied + + align:start position:0% +we saw before is going to be multiplied + + + align:start position:0% +we saw before is going to be multiplied +by a + + align:start position:0% +by a + + + align:start position:0% +by a +cosign function which comes about + + align:start position:0% +cosign function which comes about + + + align:start position:0% +cosign function which comes about +because of the separation of this uh and + + align:start position:0% +because of the separation of this uh and + + + align:start position:0% +because of the separation of this uh and +of course because this this distance is + + align:start position:0% +of course because this this distance is + + + align:start position:0% +of course because this this distance is +actually much bigger than the width of + + align:start position:0% +actually much bigger than the width of + + + align:start position:0% +actually much bigger than the width of +the + + align:start position:0% +the + + + align:start position:0% +the +rectangle the spacing of the of the + + align:start position:0% +rectangle the spacing of the of the + + + align:start position:0% +rectangle the spacing of the of the +cosine is much finer uh than the fora + + align:start position:0% +cosine is much finer uh than the fora + + + align:start position:0% +cosine is much finer uh than the fora +transform of the rectangle and so that's + + align:start position:0% +transform of the rectangle and so that's + + + align:start position:0% +transform of the rectangle and so that's +why these fringes you see these + + align:start position:0% +why these fringes you see these + + + align:start position:0% +why these fringes you see these +fringes very fine fringes become they + + align:start position:0% +fringes very fine fringes become they + + + align:start position:0% +fringes very fine fringes become they +become a a a a result of the fact that + + align:start position:0% +become a a a a result of the fact that + + + align:start position:0% +become a a a a result of the fact that +these components here are quite well + + align:start position:0% +these components here are quite well + + + align:start position:0% +these components here are quite well +separated uh so that's another very nice + + align:start position:0% +separated uh so that's another very nice + + + align:start position:0% +separated uh so that's another very nice +example uh and uh so all these all these + + align:start position:0% +example uh and uh so all these all these + + + align:start position:0% +example uh and uh so all these all these +um uh theorems that you learn in FIA + + align:start position:0% +um uh theorems that you learn in FIA + + + align:start position:0% +um uh theorems that you learn in FIA +transforms uh can all be directly taken + + align:start position:0% +transforms uh can all be directly taken + + + align:start position:0% +transforms uh can all be directly taken +over into Optics and uh sometimes they + + align:start position:0% +over into Optics and uh sometimes they + + + align:start position:0% +over into Optics and uh sometimes they +can save a lot of work because you can + + align:start position:0% +can save a lot of work because you can + + + align:start position:0% +can save a lot of work because you can +just use the standard forms for things + + align:start position:0% +just use the standard forms for things + + + align:start position:0% +just use the standard forms for things +that you can look up in a book of tables + + align:start position:0% +that you can look up in a book of tables + + + align:start position:0% +that you can look up in a book of tables +uh and uh would saves you a lot of + + align:start position:0% +uh and uh would saves you a lot of + + + align:start position:0% +uh and uh would saves you a lot of +algebra or even worse arithmetic + + align:start position:0% +algebra or even worse arithmetic + + + align:start position:0% +algebra or even worse arithmetic +right so this is another example so now + + align:start position:0% +right so this is another example so now + + + align:start position:0% +right so this is another example so now +we're back to the the bigger rectangle + + align:start position:0% +we're back to the the bigger rectangle + + + align:start position:0% +we're back to the the bigger rectangle +or something close to the bigger + + align:start position:0% +or something close to the bigger + + + align:start position:0% +or something close to the bigger +rectangle uh the fer transform of the + + align:start position:0% +rectangle uh the fer transform of the + + + align:start position:0% +rectangle uh the fer transform of the +rectangle we saw + + align:start position:0% +rectangle we saw + + + align:start position:0% +rectangle we saw +before uh but now this one you see the + + align:start position:0% +before uh but now this one you see the + + + align:start position:0% +before uh but now this one you see the +this is multiplied by some fringes so + + align:start position:0% +this is multiplied by some fringes so + + + align:start position:0% +this is multiplied by some fringes so +this is like the opposite of this one + + align:start position:0% +this is like the opposite of this one + + + align:start position:0% +this is like the opposite of this one +really so this is a this is a + + align:start position:0% +really so this is a this is a + + + align:start position:0% +really so this is a this is a +convolution this is a product so we use + + align:start position:0% +convolution this is a product so we use + + + align:start position:0% +convolution this is a product so we use +the same convolution theorem again uh + + align:start position:0% +the same convolution theorem again uh + + + align:start position:0% +the same convolution theorem again uh +the uh the fringes of course correspond + + align:start position:0% +the uh the fringes of course correspond + + + align:start position:0% +the uh the fringes of course correspond +just like we said before the fer + + align:start position:0% +just like we said before the fer + + + align:start position:0% +just like we said before the fer +transform of the three Delta functions + + align:start position:0% +transform of the three Delta functions + + + align:start position:0% +transform of the three Delta functions +with the fringes so the fer transform of + + align:start position:0% +with the fringes so the fer transform of + + + align:start position:0% +with the fringes so the fer transform of +the fringes is the is is like three + + align:start position:0% +the fringes is the is is like three + + + align:start position:0% +the fringes is the is is like three +Delta functions so what we'd expect this + + align:start position:0% +Delta functions so what we'd expect this + + + align:start position:0% +Delta functions so what we'd expect this +is a product of the fringes and the + + align:start position:0% +is a product of the fringes and the + + + align:start position:0% +is a product of the fringes and the +rectangle so we expect here to see the + + align:start position:0% +rectangle so we expect here to see the + + + align:start position:0% +rectangle so we expect here to see the +convolution of the fer transform of the + + align:start position:0% +convolution of the fer transform of the + + + align:start position:0% +convolution of the fer transform of the +fringes and the forer transform of the + + align:start position:0% +fringes and the forer transform of the + + + align:start position:0% +fringes and the forer transform of the +rectangle and that's that's what we see + + align:start position:0% +rectangle and that's that's what we see + + + align:start position:0% +rectangle and that's that's what we see +so we see three of these defraction + + align:start position:0% +so we see three of these defraction + + + align:start position:0% +so we see three of these defraction +patterns uh + + align:start position:0% +patterns uh + + + align:start position:0% +patterns uh +um situated on these three spots + + align:start position:0% +um situated on these three spots + + + align:start position:0% +um situated on these three spots +corresponding to the foror transform of + + align:start position:0% +corresponding to the foror transform of + + + align:start position:0% +corresponding to the foror transform of +that grating right so uh very nice uh + + align:start position:0% +that grating right so uh very nice uh + + + align:start position:0% +that grating right so uh very nice uh +display that one I like that + + align:start position:0% + + + + align:start position:0% + +one uh okay so yeah so this is now + + align:start position:0% +one uh okay so yeah so this is now + + + align:start position:0% +one uh okay so yeah so this is now +introducing um the idea of the What's + + align:start position:0% +introducing um the idea of the What's + + + align:start position:0% +introducing um the idea of the What's +called the 4f system so we're going to + + align:start position:0% +called the 4f system so we're going to + + + align:start position:0% +called the 4f system so we're going to +do not this not just once but do it + + align:start position:0% +do not this not just once but do it + + + align:start position:0% +do not this not just once but do it +twice so this is shows what we've had so + + align:start position:0% +twice so this is shows what we've had so + + + align:start position:0% +twice so this is shows what we've had so +far if we got some uh particular + + align:start position:0% +far if we got some uh particular + + + align:start position:0% +far if we got some uh particular +transparency we get some + + align:start position:0% +transparency we get some + + + align:start position:0% +transparency we get some +particular uh defraction pattern in the + + align:start position:0% +particular uh defraction pattern in the + + + align:start position:0% +particular uh defraction pattern in the +back focal + + align:start position:0% +back focal + + + align:start position:0% +back focal +plane and then in the 4f system we do + + align:start position:0% +plane and then in the 4f system we do + + + align:start position:0% +plane and then in the 4f system we do +the same again we now have another + + align:start position:0% +the same again we now have another + + + align:start position:0% +the same again we now have another +lens uh which is going to do exactly the + + align:start position:0% +lens uh which is going to do exactly the + + + align:start position:0% +lens uh which is going to do exactly the +same uh it's going to look at this + + align:start position:0% +same uh it's going to look at this + + + align:start position:0% +same uh it's going to look at this +pattern and produce its fer transform so + + align:start position:0% +pattern and produce its fer transform so + + + align:start position:0% +pattern and produce its fer transform so +if if uh remember if if the if this is f + + align:start position:0% +if if uh remember if if the if this is f + + + align:start position:0% +if if uh remember if if the if this is f +and this is f and this is f and this is + + align:start position:0% +and this is f and this is f and this is + + + align:start position:0% +and this is f and this is f and this is +f we won't have to worry anything about + + align:start position:0% +f we won't have to worry anything about + + + align:start position:0% +f we won't have to worry anything about +these parabolic phases it's just + + align:start position:0% +these parabolic phases it's just + + + align:start position:0% +these parabolic phases it's just +straight for a transforms with nothing + + align:start position:0% +straight for a transforms with nothing + + + align:start position:0% +straight for a transforms with nothing +else uh and uh so you can see what you + + align:start position:0% +else uh and uh so you can see what you + + + align:start position:0% +else uh and uh so you can see what you +get very simple you start off with this + + align:start position:0% +get very simple you start off with this + + + align:start position:0% +get very simple you start off with this +object so here you get uh is fer + + align:start position:0% +object so here you get uh is fer + + + align:start position:0% +object so here you get uh is fer +transform and if you take the fer + + align:start position:0% +transform and if you take the fer + + + align:start position:0% +transform and if you take the fer +transform of the F trans transform what + + align:start position:0% +transform of the F trans transform what + + + align:start position:0% +transform of the F trans transform what +do you get if you do a fer transform of + + align:start position:0% +do you get if you do a fer transform of + + + align:start position:0% +do you get if you do a fer transform of +a for + + align:start position:0% +a for + + + align:start position:0% +a for +transform yeah it's not quite is it you + + align:start position:0% +transform yeah it's not quite is it you + + + align:start position:0% +transform yeah it's not quite is it you +remember you're inverted that's right + + align:start position:0% +remember you're inverted that's right + + + align:start position:0% +remember you're inverted that's right +yeah so someone got that the um uh if + + align:start position:0% +yeah so someone got that the um uh if + + + align:start position:0% +yeah so someone got that the um uh if +you remember if you if you do a a fer + + align:start position:0% +you remember if you if you do a a fer + + + align:start position:0% +you remember if you if you do a a fer +transform of a fer transform you get the + + align:start position:0% +transform of a fer transform you get the + + + align:start position:0% +transform of a fer transform you get the +original function inverted you have to + + align:start position:0% +original function inverted you have to + + + align:start position:0% +original function inverted you have to +take for a transform four times and then + + align:start position:0% +take for a transform four times and then + + + align:start position:0% +take for a transform four times and then +you get back to where you + + align:start position:0% +you get back to where you + + + align:start position:0% +you get back to where you +start uh and uh so that's what we can + + align:start position:0% +start uh and uh so that's what we can + + + align:start position:0% +start uh and uh so that's what we can +see anyway so this is the uh inverted + + align:start position:0% +see anyway so this is the uh inverted + + + align:start position:0% +see anyway so this is the uh inverted +well of course inverted it's just what + + align:start position:0% +well of course inverted it's just what + + + align:start position:0% +well of course inverted it's just what +we expect isn't it because we know that + + align:start position:0% +we expect isn't it because we know that + + + align:start position:0% +we expect isn't it because we know that +when we have an IM Imaging system we get + + align:start position:0% +when we have an IM Imaging system we get + + + align:start position:0% +when we have an IM Imaging system we get +an inverted image so it's it everything + + align:start position:0% +an inverted image so it's it everything + + + align:start position:0% +an inverted image so it's it everything +fits together uh it gives exactly the + + align:start position:0% +fits together uh it gives exactly the + + + align:start position:0% +fits together uh it gives exactly the +same results that we expect from our + + align:start position:0% +same results that we expect from our + + + align:start position:0% +same results that we expect from our +geometrical + + align:start position:0% +geometrical + + + align:start position:0% +geometrical +Optics uh and um so in this case of + + align:start position:0% +Optics uh and um so in this case of + + + align:start position:0% +Optics uh and um so in this case of +course this is a rather symmetrical OB + + align:start position:0% +course this is a rather symmetrical OB + + + align:start position:0% +course this is a rather symmetrical OB +object so the fact that this is been + + align:start position:0% +object so the fact that this is been + + + align:start position:0% +object so the fact that this is been +inverted I guess you can't really even + + align:start position:0% +inverted I guess you can't really even + + + align:start position:0% +inverted I guess you can't really even +see + + align:start position:0% + + + + align:start position:0% + +okay so so this is saying then uh that + + align:start position:0% +okay so so this is saying then uh that + + + align:start position:0% +okay so so this is saying then uh that +you can um make a 4f system uh which + + align:start position:0% +you can um make a 4f system uh which + + + align:start position:0% +you can um make a 4f system uh which +produces then an uh an inverted version + + align:start position:0% +produces then an uh an inverted version + + + align:start position:0% +produces then an uh an inverted version +of the original object you might wonder + + align:start position:0% +of the original object you might wonder + + + align:start position:0% +of the original object you might wonder +what the point of that is I mean I guess + + align:start position:0% +what the point of that is I mean I guess + + + align:start position:0% +what the point of that is I mean I guess +in a + + align:start position:0% +in a + + + align:start position:0% +in a +way uh there's no point in making an an + + align:start position:0% +way uh there's no point in making an an + + + align:start position:0% +way uh there's no point in making an an +image which is much the same as the + + align:start position:0% +image which is much the same as the + + + align:start position:0% +image which is much the same as the +object really um but one reason why you + + align:start position:0% +object really um but one reason why you + + + align:start position:0% +object really um but one reason why you +might want well there's two reasons one + + align:start position:0% +might want well there's two reasons one + + + align:start position:0% +might want well there's two reasons one +is that it's actually of course moved + + align:start position:0% +is that it's actually of course moved + + + align:start position:0% +is that it's actually of course moved +it's it's produced this image in a + + align:start position:0% +it's it's produced this image in a + + + align:start position:0% +it's it's produced this image in a +different plane so it's actually it's + + align:start position:0% +different plane so it's actually it's + + + align:start position:0% +different plane so it's actually it's +like transported the this distribution + + align:start position:0% +like transported the this distribution + + + align:start position:0% +like transported the this distribution +of light here from this plane to this + + align:start position:0% +of light here from this plane to this + + + align:start position:0% +of light here from this plane to this +plane uh so that's one type of + + align:start position:0% +plane uh so that's one type of + + + align:start position:0% +plane uh so that's one type of +application where you might want to do + + align:start position:0% +application where you might want to do + + + align:start position:0% +application where you might want to do +something like this um and the second + + align:start position:0% +something like this um and the second + + + align:start position:0% +something like this um and the second +thing of course uh is that although this + + align:start position:0% +thing of course uh is that although this + + + align:start position:0% +thing of course uh is that although this +is always called a 4f system uh the we + + align:start position:0% +is always called a 4f system uh the we + + + align:start position:0% +is always called a 4f system uh the we +we obviously have to have this and this + + align:start position:0% +we obviously have to have this and this + + + align:start position:0% +we obviously have to have this and this +F both equal for this to work we have to + + align:start position:0% +F both equal for this to work we have to + + + align:start position:0% +F both equal for this to work we have to +have this and this F to be equal for it + + align:start position:0% +have this and this F to be equal for it + + + align:start position:0% +have this and this F to be equal for it +to work but this F doesn't have to be + + align:start position:0% +to work but this F doesn't have to be + + + align:start position:0% +to work but this F doesn't have to be +the same as that F so you can actually + + align:start position:0% +the same as that F so you can actually + + + align:start position:0% +the same as that F so you can actually +have a system like this where you + + align:start position:0% +have a system like this where you + + + align:start position:0% +have a system like this where you +actually produce a magnified image or a + + align:start position:0% +actually produce a magnified image or a + + + align:start position:0% +actually produce a magnified image or a +demagnified image uh and now that of + + align:start position:0% +demagnified image uh and now that of + + + align:start position:0% +demagnified image uh and now that of +course is getting a lot more + + align:start position:0% + + + + align:start position:0% + +useful uh so so that's how you can + + align:start position:0% +useful uh so so that's how you can + + + align:start position:0% +useful uh so so that's how you can +produce an image of a of an object in + + align:start position:0% +produce an image of a of an object in + + + align:start position:0% +produce an image of a of an object in +another + + align:start position:0% +another + + + align:start position:0% +another +plane uh now the next thing to note is + + align:start position:0% +plane uh now the next thing to note is + + + align:start position:0% +plane uh now the next thing to note is +of course so we're we're we're so far + + align:start position:0% +of course so we're we're we're so far + + + align:start position:0% +of course so we're we're we're so far +we've assumed that all this light gets + + align:start position:0% +we've assumed that all this light gets + + + align:start position:0% +we've assumed that all this light gets +through this Optical system and gets + + align:start position:0% +through this Optical system and gets + + + align:start position:0% +through this Optical system and gets +here uh so if that was the case you get + + align:start position:0% +here uh so if that was the case you get + + + align:start position:0% +here uh so if that was the case you get +a perfect image if all the information + + align:start position:0% +a perfect image if all the information + + + align:start position:0% +a perfect image if all the information +from the object was getting to the image + + align:start position:0% +from the object was getting to the image + + + align:start position:0% +from the object was getting to the image +uh then you wouldn't lose anything but + + align:start position:0% +uh then you wouldn't lose anything but + + + align:start position:0% +uh then you wouldn't lose anything but +in practice of course that's never going + + align:start position:0% +in practice of course that's never going + + + align:start position:0% +in practice of course that's never going +to be true um and um well one one way + + align:start position:0% +to be true um and um well one one way + + + align:start position:0% +to be true um and um well one one way +it's not going to be true of course is + + align:start position:0% +it's not going to be true of course is + + + align:start position:0% +it's not going to be true of course is +because in practice these lenses are + + align:start position:0% +because in practice these lenses are + + + align:start position:0% +because in practice these lenses are +never going to be infinitely large right + + align:start position:0% +never going to be infinitely large right + + + align:start position:0% +never going to be infinitely large right +so um but also uh we could if we wanted + + align:start position:0% +so um but also uh we could if we wanted + + + align:start position:0% +so um but also uh we could if we wanted +to actually put some sort of um mask in + + align:start position:0% +to actually put some sort of um mask in + + + align:start position:0% +to actually put some sort of um mask in +this plane here uh to actually stop some + + align:start position:0% +this plane here uh to actually stop some + + + align:start position:0% +this plane here uh to actually stop some +of that light getting through to the F + + align:start position:0% +of that light getting through to the F + + + align:start position:0% +of that light getting through to the F +to the image plane uh and so now we're + + align:start position:0% +to the image plane uh and so now we're + + + align:start position:0% +to the image plane uh and so now we're +going to look at what happens + + align:start position:0% +going to look at what happens + + + align:start position:0% +going to look at what happens +uh if we do that uh this is much the + + align:start position:0% +uh if we do that uh this is much the + + + align:start position:0% +uh if we do that uh this is much the +same overall effect as George spoke + + align:start position:0% +same overall effect as George spoke + + + align:start position:0% +same overall effect as George spoke +about in previous lectures actually not + + align:start position:0% +about in previous lectures actually not + + + align:start position:0% +about in previous lectures actually not +Imaging case but he spoke about you + + align:start position:0% +Imaging case but he spoke about you + + + align:start position:0% +Imaging case but he spoke about you +remember the the results with the the + + align:start position:0% +remember the the results with the the + + + align:start position:0% +remember the the results with the the +building with the windows that you could + + align:start position:0% +building with the windows that you could + + + align:start position:0% +building with the windows that you could +actually uh you could actually but by + + align:start position:0% +actually uh you could actually but by + + + align:start position:0% +actually uh you could actually but by +just by doing processing digital + + align:start position:0% +just by doing processing digital + + + align:start position:0% +just by doing processing digital +processing on the fer transforms you can + + align:start position:0% +processing on the fer transforms you can + + + align:start position:0% +processing on the fer transforms you can +manipulate the strength of the grading + + align:start position:0% +manipulate the strength of the grading + + + align:start position:0% +manipulate the strength of the grading +components in the final image uh so the + + align:start position:0% +components in the final image uh so the + + + align:start position:0% +components in the final image uh so the +same is true here except now we're doing + + align:start position:0% +same is true here except now we're doing + + + align:start position:0% +same is true here except now we're doing +it optically uh rather than digitally + + align:start position:0% +it optically uh rather than digitally + + + align:start position:0% +it optically uh rather than digitally +right so what you'd expect then is if we + + align:start position:0% +right so what you'd expect then is if we + + + align:start position:0% +right so what you'd expect then is if we +put something in here so here this is + + align:start position:0% +put something in here so here this is + + + align:start position:0% +put something in here so here this is +showing a a a pass band so let's say you + + align:start position:0% +showing a a a pass band so let's say you + + + align:start position:0% +showing a a a pass band so let's say you +put in here some uh opak screen with a + + align:start position:0% +put in here some uh opak screen with a + + + align:start position:0% +put in here some uh opak screen with a +small hole in the hole is this pass band + + align:start position:0% +small hole in the hole is this pass band + + + align:start position:0% +small hole in the hole is this pass band +uh and the screen is the Block band so + + align:start position:0% +uh and the screen is the Block band so + + + align:start position:0% +uh and the screen is the Block band so +it only lets through the region in the + + align:start position:0% +it only lets through the region in the + + + align:start position:0% +it only lets through the region in the +center + + align:start position:0% +center + + + align:start position:0% +center +according to how big that uh pass band + + align:start position:0% +according to how big that uh pass band + + + align:start position:0% +according to how big that uh pass band +is you'll get different answers in the + + align:start position:0% +is you'll get different answers in the + + + align:start position:0% +is you'll get different answers in the +uh in the um image + + align:start position:0% + + + + align:start position:0% + +plane yeah of course it says uh the + + align:start position:0% +plane yeah of course it says uh the + + + align:start position:0% +plane yeah of course it says uh the +transparency may be a gray scale uh it + + align:start position:0% +transparency may be a gray scale uh it + + + align:start position:0% +transparency may be a gray scale uh it +doesn't have to be a binary type thing + + align:start position:0% +doesn't have to be a binary type thing + + + align:start position:0% +doesn't have to be a binary type thing +black and white uh or it could even be a + + align:start position:0% +black and white uh or it could even be a + + + align:start position:0% +black and white uh or it could even be a +phase mask it could be that uh that this + + align:start position:0% +phase mask it could be that uh that this + + + align:start position:0% +phase mask it could be that uh that this +is uh changing the phase by let's say uh + + align:start position:0% +is uh changing the phase by let's say uh + + + align:start position:0% +is uh changing the phase by let's say uh +pi by2 relative to this or Pi relative + + align:start position:0% +pi by2 relative to this or Pi relative + + + align:start position:0% +pi by2 relative to this or Pi relative +to this or whatever and you'll get + + align:start position:0% +to this or whatever and you'll get + + + align:start position:0% +to this or whatever and you'll get +you'll get different answers according + + align:start position:0% +you'll get different answers according + + + align:start position:0% +you'll get different answers according +to what you choose obviously for the + + align:start position:0% +to what you choose obviously for the + + + align:start position:0% +to what you choose obviously for the +geometry of this what we call spatial + + align:start position:0% + + + + align:start position:0% + +filter okay so um yeah so this is going + + align:start position:0% +filter okay so um yeah so this is going + + + align:start position:0% +filter okay so um yeah so this is going +back to this idea of these two ways of + + align:start position:0% +back to this idea of these two ways of + + + align:start position:0% +back to this idea of these two ways of +thinking about the same problem uh so uh + + align:start position:0% +thinking about the same problem uh so uh + + + align:start position:0% +thinking about the same problem uh so uh +this is the first way where we think of + + align:start position:0% +this is the first way where we think of + + + align:start position:0% +this is the first way where we think of +our objects as being made up of lots of + + align:start position:0% +our objects as being made up of lots of + + + align:start position:0% +our objects as being made up of lots of +Point scatterers each of these + + align:start position:0% +Point scatterers each of these + + + align:start position:0% +Point scatterers each of these +scatterers gives way uh gives rise to uh + + align:start position:0% +scatterers gives way uh gives rise to uh + + + align:start position:0% +scatterers gives way uh gives rise to uh +like hyan spherical + + align:start position:0% +like hyan spherical + + + align:start position:0% +like hyan spherical +wavelets uh these are each of these is + + align:start position:0% +wavelets uh these are each of these is + + + align:start position:0% +wavelets uh these are each of these is +collected by a lens uh the lens converts + + align:start position:0% +collected by a lens uh the lens converts + + + align:start position:0% +collected by a lens uh the lens converts +that to a plain + + align:start position:0% +that to a plain + + + align:start position:0% +that to a plain +wave the plain wave reaches the second + + align:start position:0% +wave the plain wave reaches the second + + + align:start position:0% +wave the plain wave reaches the second +lens uh and because it's a plain Wave + + align:start position:0% +lens uh and because it's a plain Wave + + + align:start position:0% +lens uh and because it's a plain Wave +It's converted back to a spherical wave + + align:start position:0% +It's converted back to a spherical wave + + + align:start position:0% +It's converted back to a spherical wave +that converges a distance F uh away from + + align:start position:0% +that converges a distance F uh away from + + + align:start position:0% +that converges a distance F uh away from +that and now uh we've actually + + align:start position:0% +that and now uh we've actually + + + align:start position:0% +that and now uh we've actually +introduced the fact that these FS can be + + align:start position:0% +introduced the fact that these FS can be + + + align:start position:0% +introduced the fact that these FS can be +different so fub1 FS2 fub1 sorry fub1 + + align:start position:0% +different so fub1 FS2 fub1 sorry fub1 + + + align:start position:0% +different so fub1 FS2 fub1 sorry fub1 +F2 this has to be equal to this and this + + align:start position:0% +F2 this has to be equal to this and this + + + align:start position:0% +F2 this has to be equal to this and this +has to be equal to this otherwise the uh + + align:start position:0% +has to be equal to this otherwise the uh + + + align:start position:0% +has to be equal to this otherwise the uh +the phases won't cancel out + + align:start position:0% +the phases won't cancel out + + + align:start position:0% +the phases won't cancel out +properly and um so you can see that what + + align:start position:0% +properly and um so you can see that what + + + align:start position:0% +properly and um so you can see that what +you'd expect then uh is that because in + + align:start position:0% +you'd expect then uh is that because in + + + align:start position:0% +you'd expect then uh is that because in +this diagram here F1 one is bigger than + + align:start position:0% +this diagram here F1 one is bigger than + + + align:start position:0% +this diagram here F1 one is bigger than +F2 this image is actually uh smaller + + align:start position:0% +F2 this image is actually uh smaller + + + align:start position:0% +F2 this image is actually uh smaller +than the original + + align:start position:0% +than the original + + + align:start position:0% +than the original +object uh and and note now you can also + + align:start position:0% +object uh and and note now you can also + + + align:start position:0% +object uh and and note now you can also +see directly the um the geometry showing + + align:start position:0% +see directly the um the geometry showing + + + align:start position:0% +see directly the um the geometry showing +the inversion the point above the axis + + align:start position:0% +the inversion the point above the axis + + + align:start position:0% +the inversion the point above the axis +has come to an image uh below the axis + + align:start position:0% +has come to an image uh below the axis + + + align:start position:0% +has come to an image uh below the axis +here right so that's the one way of + + align:start position:0% +here right so that's the one way of + + + align:start position:0% +here right so that's the one way of +thinking about it uh and and then the + + align:start position:0% +thinking about it uh and and then the + + + align:start position:0% +thinking about it uh and and then the +other way is to think in terms of + + align:start position:0% +other way is to think in terms of + + + align:start position:0% +other way is to think in terms of +spatial frequencies we think of this + + align:start position:0% +spatial frequencies we think of this + + + align:start position:0% +spatial frequencies we think of this +object as being like a grating which is + + align:start position:0% +object as being like a grating which is + + + align:start position:0% +object as being like a grating which is +going to produce grating orders which + + align:start position:0% +going to produce grating orders which + + + align:start position:0% +going to produce grating orders which +travel in different directions each of + + align:start position:0% +travel in different directions each of + + + align:start position:0% +travel in different directions each of +these grating orders is like a a plain + + align:start position:0% +these grating orders is like a a plain + + + align:start position:0% +these grating orders is like a a plain +wave uh and when it reaches the lens + + align:start position:0% +wave uh and when it reaches the lens + + + align:start position:0% +wave uh and when it reaches the lens +it's going to um produce a converging + + align:start position:0% +it's going to um produce a converging + + + align:start position:0% +it's going to um produce a converging +spherical wave which comes to a focus a + + align:start position:0% +spherical wave which comes to a focus a + + + align:start position:0% +spherical wave which comes to a focus a +distance F behind the + + align:start position:0% +distance F behind the + + + align:start position:0% +distance F behind the +lens uh and then after that of course it + + align:start position:0% +lens uh and then after that of course it + + + align:start position:0% +lens uh and then after that of course it +doesn't stop but it Carries On diverges + + align:start position:0% +doesn't stop but it Carries On diverges + + + align:start position:0% +doesn't stop but it Carries On diverges +Again reaches the second lens uh and + + align:start position:0% +Again reaches the second lens uh and + + + align:start position:0% +Again reaches the second lens uh and +then the second lens because this is a + + align:start position:0% +then the second lens because this is a + + + align:start position:0% +then the second lens because this is a +spherical wave coming from a distance + + align:start position:0% +spherical wave coming from a distance + + + align:start position:0% +spherical wave coming from a distance +half away is converted into a plane wave + + align:start position:0% +half away is converted into a plane wave + + + align:start position:0% +half away is converted into a plane wave +again right so again you got this this + + align:start position:0% +again right so again you got this this + + + align:start position:0% +again right so again you got this this +nice symmetry uh between the the what + + align:start position:0% +nice symmetry uh between the the what + + + align:start position:0% +nice symmetry uh between the the what +goes in and what comes out uh so there + + align:start position:0% +goes in and what comes out uh so there + + + align:start position:0% +goes in and what comes out uh so there +are these two different um really + + align:start position:0% +are these two different um really + + + align:start position:0% +are these two different um really +different ways of U thinking about how + + align:start position:0% +different ways of U thinking about how + + + align:start position:0% +different ways of U thinking about how +this is all going + + align:start position:0% + + + + align:start position:0% + +on end of + + align:start position:0% + + + + align:start position:0% + +show right + + align:start position:0% +show right + + + align:start position:0% +show right +then right okay so so all that was U + + align:start position:0% +then right okay so so all that was U + + + align:start position:0% +then right okay so so all that was U +that was just a warmup uh that was last + + align:start position:0% +that was just a warmup uh that was last + + + align:start position:0% +that was just a warmup uh that was last +week's lecture last Monday's lecture + + align:start position:0% +week's lecture last Monday's lecture + + + align:start position:0% +week's lecture last Monday's lecture +we've done so far + + align:start position:0% + + + + align:start position:0% + +right ah oh yeah there LS lots of + + align:start position:0% +right ah oh yeah there LS lots of + + + align:start position:0% +right ah oh yeah there LS lots of +interesting things coming up + + align:start position:0% + + + + align:start position:0% + +later okay uh so we're going to carry on + + align:start position:0% +later okay uh so we're going to carry on + + + align:start position:0% +later okay uh so we're going to carry on +straight away with this more of this 4f + + align:start position:0% +straight away with this more of this 4f + + + align:start position:0% +straight away with this more of this 4f +system and spatial filtering so um we're + + align:start position:0% +system and spatial filtering so um we're + + + align:start position:0% +system and spatial filtering so um we're +just getting stting on this and so + + align:start position:0% +just getting stting on this and so + + + align:start position:0% +just getting stting on this and so +there's lots of very interesting things + + align:start position:0% +there's lots of very interesting things + + + align:start position:0% +there's lots of very interesting things +you can do with these uh so this is back + + align:start position:0% +you can do with these uh so this is back + + + align:start position:0% +you can do with these uh so this is back +to the same thing again Ren showing + + align:start position:0% +to the same thing again Ren showing + + + align:start position:0% +to the same thing again Ren showing +again uh but bit more detailed now + + align:start position:0% +again uh but bit more detailed now + + + align:start position:0% +again uh but bit more detailed now +because we're actually going to really + + align:start position:0% +because we're actually going to really + + + align:start position:0% +because we're actually going to really +uh look in more detail of where these + + align:start position:0% +uh look in more detail of where these + + + align:start position:0% +uh look in more detail of where these +orders are are formed and what you can + + align:start position:0% +orders are are formed and what you can + + + align:start position:0% +orders are are formed and what you can +do with them uh + + align:start position:0% +do with them uh + + + align:start position:0% +do with them uh +so we have a greatting + + align:start position:0% +so we have a greatting + + + align:start position:0% +so we have a greatting +objects uh let's imagine this is just a + + align:start position:0% +objects uh let's imagine this is just a + + + align:start position:0% +objects uh let's imagine this is just a +1 plus a cosine uh which means then it + + align:start position:0% +1 plus a cosine uh which means then it + + + align:start position:0% +1 plus a cosine uh which means then it +produces a zero order and then a plus + + align:start position:0% +produces a zero order and then a plus + + + align:start position:0% +produces a zero order and then a plus +and minus one order uh so three plane + + align:start position:0% +and minus one order uh so three plane + + + align:start position:0% +and minus one order uh so three plane +waves uh and as we said each of those + + align:start position:0% +waves uh and as we said each of those + + + align:start position:0% +waves uh and as we said each of those +plain waves is going to be converted to + + align:start position:0% +plain waves is going to be converted to + + + align:start position:0% +plain waves is going to be converted to +a a converging spherical wave and so in + + align:start position:0% +a a converging spherical wave and so in + + + align:start position:0% +a a converging spherical wave and so in +this back focal plane uh you'll see + + align:start position:0% +this back focal plane uh you'll see + + + align:start position:0% +this back focal plane uh you'll see +three spots corresponding to the three + + align:start position:0% +three spots corresponding to the three + + + align:start position:0% +three spots corresponding to the three +orders uh and uh and then carrying on uh + + align:start position:0% +orders uh and uh and then carrying on uh + + + align:start position:0% +orders uh and uh and then carrying on uh +these plane waves then converted back + + align:start position:0% +these plane waves then converted back + + + align:start position:0% +these plane waves then converted back +into a sperical wave and you get an + + align:start position:0% +into a sperical wave and you get an + + + align:start position:0% +into a sperical wave and you get an +image which is back to the grating again + + align:start position:0% +image which is back to the grating again + + + align:start position:0% +image which is back to the grating again +right so at the moment the optical + + align:start position:0% +right so at the moment the optical + + + align:start position:0% +right so at the moment the optical +system has transmitted all the + + align:start position:0% +system has transmitted all the + + + align:start position:0% +system has transmitted all the +information and so what we would expect + + align:start position:0% +information and so what we would expect + + + align:start position:0% +information and so what we would expect +is that the image uh is exactly the same + + align:start position:0% +is that the image uh is exactly the same + + + align:start position:0% +is that the image uh is exactly the same +as the object apart from the fact it's + + align:start position:0% +as the object apart from the fact it's + + + align:start position:0% +as the object apart from the fact it's +inverted and it might be magnified or or + + align:start position:0% +inverted and it might be magnified or or + + + align:start position:0% +inverted and it might be magnified or or +the opposite uh so but the the + + align:start position:0% +the opposite uh so but the the + + + align:start position:0% +the opposite uh so but the the +resolution you'd expect would be the + + align:start position:0% +resolution you'd expect would be the + + + align:start position:0% +resolution you'd expect would be the +same all the detail in here you'd expect + + align:start position:0% +same all the detail in here you'd expect + + + align:start position:0% +same all the detail in here you'd expect +to see in there right now so the next + + align:start position:0% +to see in there right now so the next + + + align:start position:0% +to see in there right now so the next +thing to look at is what happens if we + + align:start position:0% +thing to look at is what happens if we + + + align:start position:0% +thing to look at is what happens if we +now Place something in this plane that + + align:start position:0% +now Place something in this plane that + + + align:start position:0% +now Place something in this plane that +changes the relative strength of these + + align:start position:0% +changes the relative strength of these + + + align:start position:0% +changes the relative strength of these +different orders and there are lots of + + align:start position:0% +different orders and there are lots of + + + align:start position:0% +different orders and there are lots of +things that we could try uh the first + + align:start position:0% +things that we could try uh the first + + + align:start position:0% +things that we could try uh the first +one the simplest one to look at uh is + + align:start position:0% +one the simplest one to look at uh is + + + align:start position:0% +one the simplest one to look at uh is +what happens if we just put in something + + align:start position:0% +what happens if we just put in something + + + align:start position:0% +what happens if we just put in something +uh a mask here that lets through the + + align:start position:0% +uh a mask here that lets through the + + + align:start position:0% +uh a mask here that lets through the +zero order and not the others the two + + align:start position:0% +zero order and not the others the two + + + align:start position:0% +zero order and not the others the two +two the plus one and the minus one order + + align:start position:0% +two the plus one and the minus one order + + + align:start position:0% +two the plus one and the minus one order +are obstructed by this screen so all we + + align:start position:0% +are obstructed by this screen so all we + + + align:start position:0% +are obstructed by this screen so all we +let through is this single order uh + + align:start position:0% +let through is this single order uh + + + align:start position:0% +let through is this single order uh +which is going to be converted to a + + align:start position:0% +which is going to be converted to a + + + align:start position:0% +which is going to be converted to a +plain wave and so on your screen here + + align:start position:0% +plain wave and so on your screen here + + + align:start position:0% +plain wave and so on your screen here +all you'll see is the plane + + align:start position:0% +all you'll see is the plane + + + align:start position:0% +all you'll see is the plane +wave right so the the image that you see + + align:start position:0% +wave right so the the image that you see + + + align:start position:0% +wave right so the the image that you see +well I called it an image but it's not + + align:start position:0% +well I called it an image but it's not + + + align:start position:0% +well I called it an image but it's not +really much of an image it's completely + + align:start position:0% +really much of an image it's completely + + + align:start position:0% +really much of an image it's completely +featureless it's just like a a a a well + + align:start position:0% +featureless it's just like a a a a well + + + align:start position:0% +featureless it's just like a a a a well +gray spot a gray region there's no + + align:start position:0% +gray spot a gray region there's no + + + align:start position:0% +gray spot a gray region there's no +detail there so we've lost we've lost + + align:start position:0% +detail there so we've lost we've lost + + + align:start position:0% +detail there so we've lost we've lost +that + + align:start position:0% +that + + + align:start position:0% +that +structure uh the structure actually + + align:start position:0% +structure uh the structure actually + + + align:start position:0% +structure uh the structure actually +because we put this mask in here uh the + + align:start position:0% +because we put this mask in here uh the + + + align:start position:0% +because we put this mask in here uh the +structure is Bel is beyond the uh + + align:start position:0% +structure is Bel is beyond the uh + + + align:start position:0% +structure is Bel is beyond the uh +resolution limit of the optical system + + align:start position:0% +resolution limit of the optical system + + + align:start position:0% +resolution limit of the optical system +and so we can't see + + align:start position:0% + + + + align:start position:0% + +it okay so uh this is what we might call + + align:start position:0% +it okay so uh this is what we might call + + + align:start position:0% +it okay so uh this is what we might call +a low pass filter + + align:start position:0% +a low pass filter + + + align:start position:0% +a low pass filter +uh so if you think of uh these as being + + align:start position:0% +uh so if you think of uh these as being + + + align:start position:0% +uh so if you think of uh these as being +like these grating orders basically + + align:start position:0% +like these grating orders basically + + + align:start position:0% +like these grating orders basically +represent different spatial frequencies + + align:start position:0% +represent different spatial frequencies + + + align:start position:0% +represent different spatial frequencies +so just in analogy with what you have in + + align:start position:0% +so just in analogy with what you have in + + + align:start position:0% +so just in analogy with what you have in +electricity uh where you've got + + align:start position:0% +electricity uh where you've got + + + align:start position:0% +electricity uh where you've got +frequencies and time uh in space we + + align:start position:0% +frequencies and time uh in space we + + + align:start position:0% +frequencies and time uh in space we +think of uh we we've got distance and + + align:start position:0% +think of uh we we've got distance and + + + align:start position:0% +think of uh we we've got distance and +we've got spatial frequencies so this is + + align:start position:0% +we've got spatial frequencies so this is + + + align:start position:0% +we've got spatial frequencies so this is +why we we could talk about uh low pass + + align:start position:0% +why we we could talk about uh low pass + + + align:start position:0% +why we we could talk about uh low pass +filtering uh we're filtering the spatial + + align:start position:0% +filtering uh we're filtering the spatial + + + align:start position:0% +filtering uh we're filtering the spatial +frequencies and just like in in uh in in + + align:start position:0% +frequencies and just like in in uh in in + + + align:start position:0% +frequencies and just like in in uh in in +time you remember when you when you got + + align:start position:0% +time you remember when you when you got + + + align:start position:0% +time you remember when you when you got +your your Hi-Fi system if you turn turn + + align:start position:0% +your your Hi-Fi system if you turn turn + + + align:start position:0% +your your Hi-Fi system if you turn turn +down the + + align:start position:0% +down the + + + align:start position:0% +down the +treble that's acting like a a low pass + + align:start position:0% +treble that's acting like a a low pass + + + align:start position:0% +treble that's acting like a a low pass +filter it's it's cutting out the high + + align:start position:0% +filter it's it's cutting out the high + + + align:start position:0% +filter it's it's cutting out the high +frequency sound and letting through the + + align:start position:0% +frequency sound and letting through the + + + align:start position:0% +frequency sound and letting through the +low frequency sound only isn't it so + + align:start position:0% +low frequency sound only isn't it so + + + align:start position:0% +low frequency sound only isn't it so +that's what we call a low pass filter uh + + align:start position:0% +that's what we call a low pass filter uh + + + align:start position:0% +that's what we call a low pass filter uh +and this is exactly the same we put in + + align:start position:0% +and this is exactly the same we put in + + + align:start position:0% +and this is exactly the same we put in +The Mask uh it's a bit different in a + + align:start position:0% +The Mask uh it's a bit different in a + + + align:start position:0% +The Mask uh it's a bit different in a +way uh from the electronic case because + + align:start position:0% +way uh from the electronic case because + + + align:start position:0% +way uh from the electronic case because +in Optics we've got a lot more freedom + + align:start position:0% +in Optics we've got a lot more freedom + + + align:start position:0% +in Optics we've got a lot more freedom +as to what we can do uh we can actually + + align:start position:0% +as to what we can do uh we can actually + + + align:start position:0% +as to what we can do uh we can actually +put in something here which has got real + + align:start position:0% +put in something here which has got real + + + align:start position:0% +put in something here which has got real +sharp edges to it uh in in electronics + + align:start position:0% +sharp edges to it uh in in electronics + + + align:start position:0% +sharp edges to it uh in in electronics +if you try to make a filter uh there's + + align:start position:0% +if you try to make a filter uh there's + + + align:start position:0% +if you try to make a filter uh there's +there's always a limit to how much you + + align:start position:0% +there's always a limit to how much you + + + align:start position:0% +there's always a limit to how much you +can uh make the roll off of the filter + + align:start position:0% +can uh make the roll off of the filter + + + align:start position:0% +can uh make the roll off of the filter +all right so you can't get something + + align:start position:0% +all right so you can't get something + + + align:start position:0% +all right so you can't get something +that suddenly cuts off like that very + + align:start position:0% + + + + align:start position:0% + +easily okay so this is going through the + + align:start position:0% +easily okay so this is going through the + + + align:start position:0% +easily okay so this is going through the +math of this uh our original + + align:start position:0% +math of this uh our original + + + align:start position:0% +math of this uh our original +transparency then is a 1 plus + + align:start position:0% +transparency then is a 1 plus + + + align:start position:0% +transparency then is a 1 plus +cosine uh and the 1 plus cosine uh we F + + align:start position:0% +cosine uh and the 1 plus cosine uh we F + + + align:start position:0% +cosine uh and the 1 plus cosine uh we F +transform that to find the what we call + + align:start position:0% +transform that to find the what we call + + + align:start position:0% +transform that to find the what we call +the object + + align:start position:0% +the object + + + align:start position:0% +the object +Spectrum uh and um so in this case + + align:start position:0% +Spectrum uh and um so in this case + + + align:start position:0% +Spectrum uh and um so in this case +finding the fer transform of cosine is + + align:start position:0% +finding the fer transform of cosine is + + + align:start position:0% +finding the fer transform of cosine is +very straightforward because we just + + align:start position:0% +very straightforward because we just + + + align:start position:0% +very straightforward because we just +expand cosine as e to the I something + + align:start position:0% +expand cosine as e to the I something + + + align:start position:0% +expand cosine as e to the I something +plus e to Theus SI something over two uh + + align:start position:0% +plus e to Theus SI something over two uh + + + align:start position:0% +plus e to Theus SI something over two uh +and each of those e to the I type terms + + align:start position:0% +and each of those e to the I type terms + + + align:start position:0% +and each of those e to the I type terms +uh will correspond to a single uh + + align:start position:0% +uh will correspond to a single uh + + + align:start position:0% +uh will correspond to a single uh +frequency right so we can end up now + + align:start position:0% +frequency right so we can end up now + + + align:start position:0% +frequency right so we can end up now +with three terms at different + + align:start position:0% +with three terms at different + + + align:start position:0% +with three terms at different +frequencies the one for transforms to a + + align:start position:0% +frequencies the one for transforms to a + + + align:start position:0% +frequencies the one for transforms to a +Delta function of U which is a spike + + align:start position:0% +Delta function of U which is a spike + + + align:start position:0% +Delta function of U which is a spike +where U equals zero uh and the two + + align:start position:0% +where U equals zero uh and the two + + + align:start position:0% +where U equals zero uh and the two +components of the cosine correspond to + + align:start position:0% +components of the cosine correspond to + + + align:start position:0% +components of the cosine correspond to +another two uh another two Delta + + align:start position:0% +another two uh another two Delta + + + align:start position:0% +another two uh another two Delta +functions uh each + + align:start position:0% +functions uh each + + + align:start position:0% +functions uh each +situated this one's at at U equals some + + align:start position:0% +situated this one's at at U equals some + + + align:start position:0% +situated this one's at at U equals some +value u u and this one is some value U + + align:start position:0% +value u u and this one is some value U + + + align:start position:0% +value u u and this one is some value U +equals minus U right so you've got these + + align:start position:0% +equals minus U right so you've got these + + + align:start position:0% +equals minus U right so you've got these +three three spikes that we've been + + align:start position:0% +three three spikes that we've been + + + align:start position:0% +three three spikes that we've been +talking about uh for the last few slides + + align:start position:0% +talking about uh for the last few slides + + + align:start position:0% +talking about uh for the last few slides +now uh so this is the uh this is the the + + align:start position:0% +now uh so this is the uh this is the the + + + align:start position:0% +now uh so this is the uh this is the the +object Spectrum it's the angular + + align:start position:0% +object Spectrum it's the angular + + + align:start position:0% +object Spectrum it's the angular +Spectrum uh that we've got here so + + align:start position:0% +Spectrum uh that we've got here so + + + align:start position:0% +Spectrum uh that we've got here so +actually you can see that you here it + + align:start position:0% +actually you can see that you here it + + + align:start position:0% +actually you can see that you here it +basically represents the angle that + + align:start position:0% +basically represents the angle that + + + align:start position:0% +basically represents the angle that +these uh these plane waves are traveling + + align:start position:0% +these uh these plane waves are traveling + + + align:start position:0% +these uh these plane waves are traveling +in and there's three different angles + + align:start position:0% +in and there's three different angles + + + align:start position:0% +in and there's three different angles +that that the light can travel + + align:start position:0% +that that the light can travel + + + align:start position:0% +that that the light can travel +in uh and uh + + align:start position:0% +in uh and uh + + + align:start position:0% +in uh and uh +so um yeah so that will propagate then + + align:start position:0% +so um yeah so that will propagate then + + + align:start position:0% +so um yeah so that will propagate then +uh and uh so what as we've said before + + align:start position:0% +uh and uh so what as we've said before + + + align:start position:0% +uh and uh so what as we've said before +you can see that uh these these rays are + + align:start position:0% +you can see that uh these these rays are + + + align:start position:0% +you can see that uh these these rays are +moving at an angle uh and so uh as you + + align:start position:0% +moving at an angle uh and so uh as you + + + align:start position:0% +moving at an angle uh and so uh as you +trans as you go along a distance F uh + + align:start position:0% +trans as you go along a distance F uh + + + align:start position:0% +trans as you go along a distance F uh +you get a shift in the X position which + + align:start position:0% +you get a shift in the X position which + + + align:start position:0% +you get a shift in the X position which +is given by of course the this the slope + + align:start position:0% +is given by of course the this the slope + + + align:start position:0% +is given by of course the this the slope +of this the more the slope the more it + + align:start position:0% +of this the more the slope the more it + + + align:start position:0% +of this the more the slope the more it +deflects uh by the time you travel a + + align:start position:0% +deflects uh by the time you travel a + + + align:start position:0% +deflects uh by the time you travel a +distance F so this then gives the shifts + + align:start position:0% +distance F so this then gives the shifts + + + align:start position:0% +distance F so this then gives the shifts +of these two things so that's before the + + align:start position:0% +of these two things so that's before the + + + align:start position:0% +of these two things so that's before the +screen uh then then um sorry before the + + align:start position:0% +screen uh then then um sorry before the + + + align:start position:0% +screen uh then then um sorry before the +mask + + align:start position:0% + + + + align:start position:0% + +what happened did anything happen + + align:start position:0% +what happened did anything happen + + + align:start position:0% +what happened did anything happen +there + + align:start position:0% + + + + align:start position:0% + +sorry nothing + + align:start position:0% +sorry nothing + + + align:start position:0% +sorry nothing +happening oh something happened then + + align:start position:0% + + + + align:start position:0% + +we ah okay right so yeah so this is + + align:start position:0% +we ah okay right so yeah so this is + + + align:start position:0% +we ah okay right so yeah so this is +showing then uh so these Rays then uh as + + align:start position:0% +showing then uh so these Rays then uh as + + + align:start position:0% +showing then uh so these Rays then uh as +they come down here um we put in this + + align:start position:0% +they come down here um we put in this + + + align:start position:0% +they come down here um we put in this +pupil mask which is going to get rid of + + align:start position:0% +pupil mask which is going to get rid of + + + align:start position:0% +pupil mask which is going to get rid of +these two and it just leaves the other + + align:start position:0% +these two and it just leaves the other + + + align:start position:0% +these two and it just leaves the other +one so we just left them with our single + + align:start position:0% +one so we just left them with our single + + + align:start position:0% +one so we just left them with our single +um beam uh which um as we said said + + align:start position:0% +um beam uh which um as we said said + + + align:start position:0% +um beam uh which um as we said said +before gives an image which is not + + align:start position:0% +before gives an image which is not + + + align:start position:0% +before gives an image which is not +really an + + align:start position:0% + + + + align:start position:0% + +image right yeah so after the pupil mask + + align:start position:0% +image right yeah so after the pupil mask + + + align:start position:0% +image right yeah so after the pupil mask +uh we multiply by The Mask gets rid of + + align:start position:0% +uh we multiply by The Mask gets rid of + + + align:start position:0% +uh we multiply by The Mask gets rid of +those two just leaves the other one uh + + align:start position:0% +those two just leaves the other one uh + + + align:start position:0% +those two just leaves the other one uh +and then finally then um the final image + + align:start position:0% +and then finally then um the final image + + + align:start position:0% +and then finally then um the final image +you you'll see is going to be the fua + + align:start position:0% +you you'll see is going to be the fua + + + align:start position:0% +you you'll see is going to be the fua +transform of that uh and the fer + + align:start position:0% +transform of that uh and the fer + + + align:start position:0% +transform of that uh and the fer +transform of a Delta function is a + + align:start position:0% +transform of a Delta function is a + + + align:start position:0% +transform of a Delta function is a +constant uh and so you see something + + align:start position:0% +constant uh and so you see something + + + align:start position:0% +constant uh and so you see something +which has got no no detail in it + + align:start position:0% + + + + align:start position:0% + +okay so um this gives another example + + align:start position:0% +okay so um this gives another example + + + align:start position:0% +okay so um this gives another example +then uh of um here we're looking at some + + align:start position:0% +then uh of um here we're looking at some + + + align:start position:0% +then uh of um here we're looking at some +a binary amplitude grating so this is a + + align:start position:0% +a binary amplitude grating so this is a + + + align:start position:0% +a binary amplitude grating so this is a +particular example um another example so + + align:start position:0% +particular example um another example so + + + align:start position:0% +particular example um another example so +last time we looked at the cosine type + + align:start position:0% +last time we looked at the cosine type + + + align:start position:0% +last time we looked at the cosine type +thing so this one is now a binary + + align:start position:0% +thing so this one is now a binary + + + align:start position:0% +thing so this one is now a binary +grating which means that the object is + + align:start position:0% +grating which means that the object is + + + align:start position:0% +grating which means that the object is +something which is either black or + + align:start position:0% +something which is either black or + + + align:start position:0% +something which is either black or +white and we shine light onto this so uh + + align:start position:0% +white and we shine light onto this so uh + + + align:start position:0% +white and we shine light onto this so uh +it's like a square wave grating uh and + + align:start position:0% +it's like a square wave grating uh and + + + align:start position:0% +it's like a square wave grating uh and +uh so unlike the previous case where + + align:start position:0% +uh so unlike the previous case where + + + align:start position:0% +uh so unlike the previous case where +coign of course just produced those + + align:start position:0% +coign of course just produced those + + + align:start position:0% +coign of course just produced those +three three grating components uh in + + align:start position:0% +three three grating components uh in + + + align:start position:0% +three three grating components uh in +this case there's going to be a whole + + align:start position:0% +this case there's going to be a whole + + + align:start position:0% +this case there's going to be a whole +load of grating components they're going + + align:start position:0% +load of grating components they're going + + + align:start position:0% +load of grating components they're going +to go on forever uh and but they get + + align:start position:0% +to go on forever uh and but they get + + + align:start position:0% +to go on forever uh and but they get +weaker and weaker uh and uh so you can + + align:start position:0% +weaker and weaker uh and uh so you can + + + align:start position:0% +weaker and weaker uh and uh so you can +see here it shows a few of them uh the + + align:start position:0% +see here it shows a few of them uh the + + + align:start position:0% +see here it shows a few of them uh the +first the second so there'll be the + + align:start position:0% +first the second so there'll be the + + + align:start position:0% +first the second so there'll be the +third the fourth and so on and then + + align:start position:0% +third the fourth and so on and then + + + align:start position:0% +third the fourth and so on and then +minus one and so on and so on and each + + align:start position:0% +minus one and so on and so on and each + + + align:start position:0% +minus one and so on and so on and each +of these is moving at a different angle + + align:start position:0% +of these is moving at a different angle + + + align:start position:0% +of these is moving at a different angle +uh so when when the plane wave gets to + + align:start position:0% +uh so when when the plane wave gets to + + + align:start position:0% +uh so when when the plane wave gets to +the pupil mask uh it's sorry when the uh + + align:start position:0% +the pupil mask uh it's sorry when the uh + + + align:start position:0% +the pupil mask uh it's sorry when the uh +the plane wave is focused to the pupil + + align:start position:0% +the plane wave is focused to the pupil + + + align:start position:0% +the plane wave is focused to the pupil +mask it's going to reach there at a + + align:start position:0% +mask it's going to reach there at a + + + align:start position:0% +mask it's going to reach there at a +point the distance from the axis of + + align:start position:0% +point the distance from the axis of + + + align:start position:0% +point the distance from the axis of +course is going to depend on the angle + + align:start position:0% +course is going to depend on the angle + + + align:start position:0% +course is going to depend on the angle +of this uh uh plane wave component the + + align:start position:0% +of this uh uh plane wave component the + + + align:start position:0% +of this uh uh plane wave component the +gracing component right so + + align:start position:0% +gracing component right so + + + align:start position:0% +gracing component right so +so if you look here you're going to see + + align:start position:0% +so if you look here you're going to see + + + align:start position:0% +so if you look here you're going to see +all these different grating orders all + + align:start position:0% +all these different grating orders all + + + align:start position:0% +all these different grating orders all +arrayed in this position here uh and uh + + align:start position:0% +arrayed in this position here uh and uh + + + align:start position:0% +arrayed in this position here uh and uh +so uh by putting some sort of uh phase + + align:start position:0% +so uh by putting some sort of uh phase + + + align:start position:0% +so uh by putting some sort of uh phase +or all sort of mask here we can monitor + + align:start position:0% +or all sort of mask here we can monitor + + + align:start position:0% +or all sort of mask here we can monitor +and change uh the relative strength or + + align:start position:0% +and change uh the relative strength or + + + align:start position:0% +and change uh the relative strength or +phase or whatever we like of those + + align:start position:0% +phase or whatever we like of those + + + align:start position:0% +phase or whatever we like of those +different components and then they'll be + + align:start position:0% +different components and then they'll be + + + align:start position:0% +different components and then they'll be +added together and produce some nice + + align:start position:0% +added together and produce some nice + + + align:start position:0% +added together and produce some nice +effect uh that we might want to look at + + align:start position:0% +effect uh that we might want to look at + + + align:start position:0% +effect uh that we might want to look at +so uh let's see uh what we're going to + + align:start position:0% +so uh let's see uh what we're going to + + + align:start position:0% +so uh let's see uh what we're going to +get in this case so in this particular + + align:start position:0% +get in this case so in this particular + + + align:start position:0% +get in this case so in this particular +case in the picture uh the size of this + + align:start position:0% +case in the picture uh the size of this + + + align:start position:0% +case in the picture uh the size of this +aperture is enough to let through the + + align:start position:0% +aperture is enough to let through the + + + align:start position:0% +aperture is enough to let through the +central three components the zero order + + align:start position:0% +central three components the zero order + + + align:start position:0% +central three components the zero order +and the plus and minus one + + align:start position:0% +and the plus and minus one + + + align:start position:0% +and the plus and minus one +order uh but it's stopped all the other + + align:start position:0% +order uh but it's stopped all the other + + + align:start position:0% +order uh but it's stopped all the other +ones right so what you'll see here is + + align:start position:0% +ones right so what you'll see here is + + + align:start position:0% +ones right so what you'll see here is +the fer transform of this uh We've + + align:start position:0% +the fer transform of this uh We've + + + align:start position:0% +the fer transform of this uh We've +before it's the three it's these three + + align:start position:0% +before it's the three it's these three + + + align:start position:0% +before it's the three it's these three +spikes again the fer transform of the + + align:start position:0% +spikes again the fer transform of the + + + align:start position:0% +spikes again the fer transform of the +three spikes is just uh a a one plus a + + align:start position:0% +three spikes is just uh a a one plus a + + + align:start position:0% +three spikes is just uh a a one plus a +cosine the relative strengths of these + + align:start position:0% +cosine the relative strengths of these + + + align:start position:0% +cosine the relative strengths of these +might change according to uh the + + align:start position:0% +might change according to uh the + + + align:start position:0% +might change according to uh the +properties of these uh uh of the + + align:start position:0% +properties of these uh uh of the + + + align:start position:0% +properties of these uh uh of the +transmission of the Mask uh but anyway + + align:start position:0% +transmission of the Mask uh but anyway + + + align:start position:0% +transmission of the Mask uh but anyway +so what you see finally uh is uh an + + align:start position:0% +so what you see finally uh is uh an + + + align:start position:0% +so what you see finally uh is uh an +object which is like a uh you see the 1 + + align:start position:0% +object which is like a uh you see the 1 + + + align:start position:0% +object which is like a uh you see the 1 +plus cosine type uh variation in + + align:start position:0% +plus cosine type uh variation in + + + align:start position:0% +plus cosine type uh variation in +amplitude + + align:start position:0% +amplitude + + + align:start position:0% +amplitude +and uh so you notice that this thing + + align:start position:0% +and uh so you notice that this thing + + + align:start position:0% +and uh so you notice that this thing +here started with these um very Square + + align:start position:0% +here started with these um very Square + + + align:start position:0% +here started with these um very Square +edges we no longer see the very Square + + align:start position:0% +edges we no longer see the very Square + + + align:start position:0% +edges we no longer see the very Square +edges so this is an example of how we've + + align:start position:0% +edges so this is an example of how we've + + + align:start position:0% +edges so this is an example of how we've +um lost resolution the optical system + + align:start position:0% +um lost resolution the optical system + + + align:start position:0% +um lost resolution the optical system +has got a certain finite resolution + + align:start position:0% +has got a certain finite resolution + + + align:start position:0% +has got a certain finite resolution +there's detail uh in this original + + align:start position:0% +there's detail uh in this original + + + align:start position:0% +there's detail uh in this original +object that we can't actually see in the + + align:start position:0% +object that we can't actually see in the + + + align:start position:0% +object that we can't actually see in the +final image and this is because not all + + align:start position:0% +final image and this is because not all + + + align:start position:0% +final image and this is because not all +the light has got through the + + align:start position:0% + + + + align:start position:0% + +system okay so we're going to look at a + + align:start position:0% +system okay so we're going to look at a + + + align:start position:0% +system okay so we're going to look at a +particular uh case now uh this is the + + align:start position:0% +particular uh case now uh this is the + + + align:start position:0% +particular uh case now uh this is the +bit I was saying I wasn't very keen on + + align:start position:0% +bit I was saying I wasn't very keen on + + + align:start position:0% +bit I was saying I wasn't very keen on +uh no no it's all right uh but anyway + + align:start position:0% +uh no no it's all right uh but anyway + + + align:start position:0% +uh no no it's all right uh but anyway +there's a load of U maths here uh which + + align:start position:0% +there's a load of U maths here uh which + + + align:start position:0% +there's a load of U maths here uh which +I might uh actually gloss over a bit and + + align:start position:0% +I might uh actually gloss over a bit and + + + align:start position:0% +I might uh actually gloss over a bit and +let you look at it yourself later uh but + + align:start position:0% +let you look at it yourself later uh but + + + align:start position:0% +let you look at it yourself later uh but +basically then we're looking at a + + align:start position:0% +basically then we're looking at a + + + align:start position:0% +basically then we're looking at a +particular example uh the the it's a + + align:start position:0% +particular example uh the the it's a + + + align:start position:0% +particular example uh the the it's a +binary grating with perfect contrast m + + align:start position:0% +binary grating with perfect contrast m + + + align:start position:0% +binary grating with perfect contrast m +equal 1 I.E this goes from black to + + align:start position:0% +equal 1 I.E this goes from black to + + + align:start position:0% +equal 1 I.E this goes from black to +white that's what that means it's got a + + align:start position:0% +white that's what that means it's got a + + + align:start position:0% +white that's what that means it's got a +period of 10 microns right the spacing + + align:start position:0% +period of 10 microns right the spacing + + + align:start position:0% +period of 10 microns right the spacing +that the period is the distance between + + align:start position:0% +that the period is the distance between + + + align:start position:0% +that the period is the distance between +the repeat on this this + + align:start position:0% +the repeat on this this + + + align:start position:0% +the repeat on this this +grating uh and it's got a duty cycle of + + align:start position:0% +grating uh and it's got a duty cycle of + + + align:start position:0% +grating uh and it's got a duty cycle of +a + + align:start position:0% +a + + + align:start position:0% +a +third uh which means that the the um the + + align:start position:0% +third uh which means that the the um the + + + align:start position:0% +third uh which means that the the um the +white bit is a third of the black bits + + align:start position:0% +white bit is a third of the black bits + + + align:start position:0% +white bit is a third of the black bits +is that what that means a third of the + + align:start position:0% +is that what that means a third of the + + + align:start position:0% +is that what that means a third of the +whole yeah a third of the + + align:start position:0% +whole yeah a third of the + + + align:start position:0% +whole yeah a third of the +period uh + + align:start position:0% +period uh + + + align:start position:0% +period uh +okay uh and and then we're also told + + align:start position:0% +okay uh and and then we're also told + + + align:start position:0% +okay uh and and then we're also told +that the 4f system consists of two + + align:start position:0% +that the 4f system consists of two + + + align:start position:0% +that the 4f system consists of two +identical lenses of focal length FAL 20 + + align:start position:0% +identical lenses of focal length FAL 20 + + + align:start position:0% +identical lenses of focal length FAL 20 +cm so both F1 and F2 are 20 cm uh and we + + align:start position:0% +cm so both F1 and F2 are 20 cm uh and we + + + align:start position:0% +cm so both F1 and F2 are 20 cm uh and we +put a pupil mask of diameter 3 cm + + align:start position:0% +put a pupil mask of diameter 3 cm + + + align:start position:0% +put a pupil mask of diameter 3 cm +here at the at the fer plane what is the + + align:start position:0% +here at the at the fer plane what is the + + + align:start position:0% +here at the at the fer plane what is the +intensity observed at the output image + + align:start position:0% +intensity observed at the output image + + + align:start position:0% +intensity observed at the output image +plane so that's the + + align:start position:0% + + + + align:start position:0% + +question okay the sequence to solve this + + align:start position:0% +question okay the sequence to solve this + + + align:start position:0% +question okay the sequence to solve this +kind of problem uh what you got to do is + + align:start position:0% +kind of problem uh what you got to do is + + + align:start position:0% +kind of problem uh what you got to do is +to work out what you're going to get in + + align:start position:0% +to work out what you're going to get in + + + align:start position:0% +to work out what you're going to get in +this plane which is basically the for a + + align:start position:0% +this plane which is basically the for a + + + align:start position:0% +this plane which is basically the for a +transform of this uh and then you're + + align:start position:0% +transform of this uh and then you're + + + align:start position:0% +transform of this uh and then you're +going to have to + + align:start position:0% +going to have to + + + align:start position:0% +going to have to +uh multiply by the mask and see which of + + align:start position:0% +uh multiply by the mask and see which of + + + align:start position:0% +uh multiply by the mask and see which of +those orders get through right so the + + align:start position:0% +those orders get through right so the + + + align:start position:0% +those orders get through right so the +relative scaling of this defraction + + align:start position:0% +relative scaling of this defraction + + + align:start position:0% +relative scaling of this defraction +pattern and the mass uh is obviously all + + align:start position:0% +pattern and the mass uh is obviously all + + + align:start position:0% +pattern and the mass uh is obviously all +important for that if you don't get that + + align:start position:0% +important for that if you don't get that + + + align:start position:0% +important for that if you don't get that +right uh then you'll get the wrong + + align:start position:0% +right uh then you'll get the wrong + + + align:start position:0% +right uh then you'll get the wrong +answer obviously because uh you you you + + align:start position:0% +answer obviously because uh you you you + + + align:start position:0% +answer obviously because uh you you you +you'll you you might get orders getting + + align:start position:0% +you'll you you might get orders getting + + + align:start position:0% +you'll you you might get orders getting +through that shouldn't or the other way + + align:start position:0% +through that shouldn't or the other way + + + align:start position:0% +through that shouldn't or the other way +around uh and + + align:start position:0% +around uh and + + + align:start position:0% +around uh and +um so once we've done that we know now + + align:start position:0% +um so once we've done that we know now + + + align:start position:0% +um so once we've done that we know now +what the um grating orders the the the + + align:start position:0% +what the um grating orders the the the + + + align:start position:0% +what the um grating orders the the the +the fer components in the final image + + align:start position:0% +the fer components in the final image + + + align:start position:0% +the fer components in the final image +are going to be and we then do another + + align:start position:0% +are going to be and we then do another + + + align:start position:0% +are going to be and we then do another +forer transform and we got the image + + align:start position:0% + + + + align:start position:0% + +amplitude there we are right again we + + align:start position:0% +amplitude there we are right again we + + + align:start position:0% +amplitude there we are right again we +got to do scaling to get it to the right + + align:start position:0% +got to do scaling to get it to the right + + + align:start position:0% +got to do scaling to get it to the right +size normally of course at the very end + + align:start position:0% +size normally of course at the very end + + + align:start position:0% +size normally of course at the very end +we would be interested in intensity not + + align:start position:0% +we would be interested in intensity not + + + align:start position:0% +we would be interested in intensity not +amplitude as + + align:start position:0% + + + + align:start position:0% + +well okay so this is our example low + + align:start position:0% +well okay so this is our example low + + + align:start position:0% +well okay so this is our example low +pass filtering a binary amplitude + + align:start position:0% +pass filtering a binary amplitude + + + align:start position:0% +pass filtering a binary amplitude +grating uh so this is this grating as + + align:start position:0% +grating uh so this is this grating as + + + align:start position:0% +grating uh so this is this grating as +we've + + align:start position:0% +we've + + + align:start position:0% +we've +chosen uh and um so you can see here's + + align:start position:0% +chosen uh and um so you can see here's + + + align:start position:0% +chosen uh and um so you can see here's +the dimensions in in + + align:start position:0% +the dimensions in in + + + align:start position:0% +the dimensions in in +microns uh so uh this is quite a fine + + align:start position:0% +microns uh so uh this is quite a fine + + + align:start position:0% +microns uh so uh this is quite a fine +grating + + align:start position:0% +grating + + + align:start position:0% +grating +so uh you can see that it's not + + align:start position:0% +so uh you can see that it's not + + + align:start position:0% +so uh you can see that it's not +symmetrical by the way the um the um dut + + align:start position:0% +symmetrical by the way the um the um dut + + + align:start position:0% +symmetrical by the way the um the um dut +duty cycle is not a half right so the + + align:start position:0% +duty cycle is not a half right so the + + + align:start position:0% +duty cycle is not a half right so the +the width of the uh bright regions is + + align:start position:0% +the width of the uh bright regions is + + + align:start position:0% +the width of the uh bright regions is +smaller than the width of the dark + + align:start position:0% +smaller than the width of the dark + + + align:start position:0% +smaller than the width of the dark +regions uh and that's important when it + + align:start position:0% +regions uh and that's important when it + + + align:start position:0% +regions uh and that's important when it +comes to looking at the fer transform + + align:start position:0% +comes to looking at the fer transform + + + align:start position:0% +comes to looking at the fer transform +and therefore the spectrum of that uh + + align:start position:0% +and therefore the spectrum of that uh + + + align:start position:0% +and therefore the spectrum of that uh +and then uh the pupil mask uh that we're + + align:start position:0% +and then uh the pupil mask uh that we're + + + align:start position:0% +and then uh the pupil mask uh that we're +going to look at looks something like + + align:start position:0% +going to look at looks something like + + + align:start position:0% +going to look at looks something like +that we let through the frequencies near + + align:start position:0% +that we let through the frequencies near + + + align:start position:0% +that we let through the frequencies near +the center uh and we keep out reject the + + align:start position:0% +the center uh and we keep out reject the + + + align:start position:0% +the center uh and we keep out reject the +frequencies which are further from the + + align:start position:0% + + + + align:start position:0% + +center + + align:start position:0% +center + + + align:start position:0% +center +okay uh so we we got a do the fer + + align:start position:0% +okay uh so we we got a do the fer + + + align:start position:0% +okay uh so we we got a do the fer +transform of that this is a repetitive + + align:start position:0% +transform of that this is a repetitive + + + align:start position:0% +transform of that this is a repetitive +function so the fer transform just + + align:start position:0% +function so the fer transform just + + + align:start position:0% +function so the fer transform just +becomes a fuer + + align:start position:0% +becomes a fuer + + + align:start position:0% +becomes a fuer +series uh and uh this is an expression + + align:start position:0% +series uh and uh this is an expression + + + align:start position:0% +series uh and uh this is an expression +for the fer series of this uh it + + align:start position:0% +for the fer series of this uh it + + + align:start position:0% +for the fer series of this uh it +basically consists of um two parts uh + + align:start position:0% +basically consists of um two parts uh + + + align:start position:0% +basically consists of um two parts uh +there's it's it's got a a sort of + + align:start position:0% +there's it's it's got a a sort of + + + align:start position:0% +there's it's it's got a a sort of +envelope which is a + + align:start position:0% +envelope which is a + + + align:start position:0% +envelope which is a +sync uh basically this is going to + + align:start position:0% +sync uh basically this is going to + + + align:start position:0% +sync uh basically this is going to +consist of a infinite number of uh of + + align:start position:0% +consist of a infinite number of uh of + + + align:start position:0% +consist of a infinite number of uh of +discrete frequencies isn't it it's going + + align:start position:0% +discrete frequencies isn't it it's going + + + align:start position:0% +discrete frequencies isn't it it's going +to consist of a a a constant term which + + align:start position:0% +to consist of a a a constant term which + + + align:start position:0% +to consist of a a a constant term which +is the zero order term it's going to + + align:start position:0% +is the zero order term it's going to + + + align:start position:0% +is the zero order term it's going to +consist of a a a a first harmonic and + + align:start position:0% +consist of a a a a first harmonic and + + + align:start position:0% +consist of a a a a first harmonic and +then a second harmonic and a third + + align:start position:0% +then a second harmonic and a third + + + align:start position:0% +then a second harmonic and a third +harmonic and so on if the if the duty + + align:start position:0% +harmonic and so on if the if the duty + + + align:start position:0% +harmonic and so on if the if the duty +cycle had been chosen to be a half I it + + align:start position:0% +cycle had been chosen to be a half I it + + + align:start position:0% +cycle had been chosen to be a half I it +was a square wave then by symmetry it + + align:start position:0% +was a square wave then by symmetry it + + + align:start position:0% +was a square wave then by symmetry it +turns out that the second harmonic and + + align:start position:0% +turns out that the second harmonic and + + + align:start position:0% +turns out that the second harmonic and +the fourth harmonic and all those all + + align:start position:0% +the fourth harmonic and all those all + + + align:start position:0% +the fourth harmonic and all those all +vanish so you'd only end up with the + + align:start position:0% +vanish so you'd only end up with the + + + align:start position:0% +vanish so you'd only end up with the +zero the first the third fifth and so on + + align:start position:0% +zero the first the third fifth and so on + + + align:start position:0% +zero the first the third fifth and so on +uh but in general uh there will be all + + align:start position:0% +uh but in general uh there will be all + + + align:start position:0% +uh but in general uh there will be all +the orders there uh and the the relative + + align:start position:0% +the orders there uh and the the relative + + + align:start position:0% +the orders there uh and the the relative +strength of those orders uh here you can + + align:start position:0% +strength of those orders uh here you can + + + align:start position:0% +strength of those orders uh here you can +um you can see is um decide is it + + align:start position:0% +um you can see is um decide is it + + + align:start position:0% +um you can see is um decide is it +depends on the value of this sync + + align:start position:0% +depends on the value of this sync + + + align:start position:0% +depends on the value of this sync +function actually that's that's a very + + align:start position:0% +function actually that's that's a very + + + align:start position:0% +function actually that's that's a very +easy way of seeing about the even orders + + align:start position:0% +easy way of seeing about the even orders + + + align:start position:0% +easy way of seeing about the even orders +cancelling uh because uh what happens is + + align:start position:0% +cancelling uh because uh what happens is + + + align:start position:0% +cancelling uh because uh what happens is +if the duty uh the duty factor is a half + + align:start position:0% +if the duty uh the duty factor is a half + + + align:start position:0% +if the duty uh the duty factor is a half +it turns out that the even uh the even + + align:start position:0% +it turns out that the even uh the even + + + align:start position:0% +it turns out that the even uh the even +orders when cuticles even number + + align:start position:0% +orders when cuticles even number + + + align:start position:0% +orders when cuticles even number +coincide + + align:start position:0% +coincide + + + align:start position:0% +coincide +with the zeros of the sync function and + + align:start position:0% +with the zeros of the sync function and + + + align:start position:0% +with the zeros of the sync function and +that's why they vanish right uh + + align:start position:0% +that's why they vanish right uh + + + align:start position:0% +that's why they vanish right uh +so um so where this comes from uh is uh + + align:start position:0% +so um so where this comes from uh is uh + + + align:start position:0% +so um so where this comes from uh is uh +that uh so we're saying that this + + align:start position:0% +that uh so we're saying that this + + + align:start position:0% +that uh so we're saying that this +function is + + align:start position:0% +function is + + + align:start position:0% +function is +a uh maybe it's easier if I go on to the + + align:start position:0% +a uh maybe it's easier if I go on to the + + + align:start position:0% +a uh maybe it's easier if I go on to the +next line I think which is the fer + + align:start position:0% +next line I think which is the fer + + + align:start position:0% +next line I think which is the fer +transform yeah the fer transform uh so + + align:start position:0% +transform yeah the fer transform uh so + + + align:start position:0% +transform yeah the fer transform uh so +the the the fer transform the strength + + align:start position:0% +the the the fer transform the strength + + + align:start position:0% +the the the fer transform the strength +of of these components is what we're + + align:start position:0% +of of these components is what we're + + + align:start position:0% +of of these components is what we're +going to find out uh and uh so this + + align:start position:0% +going to find out uh and uh so this + + + align:start position:0% +going to find out uh and uh so this +function for transforms to something uh + + align:start position:0% +function for transforms to something uh + + + align:start position:0% +function for transforms to something uh +which is a series of Delta functions uh + + align:start position:0% +which is a series of Delta functions uh + + + align:start position:0% +which is a series of Delta functions uh +corresponding to the different orders + + align:start position:0% +corresponding to the different orders + + + align:start position:0% +corresponding to the different orders +different values of Q uh and um the + + align:start position:0% +different values of Q uh and um the + + + align:start position:0% +different values of Q uh and um the +strength of the different components is + + align:start position:0% +strength of the different components is + + + align:start position:0% +strength of the different components is +given by the value of the + + align:start position:0% +given by the value of the + + + align:start position:0% +given by the value of the +sync right so you can see again U if um + + align:start position:0% +sync right so you can see again U if um + + + align:start position:0% +sync right so you can see again U if um +if there are some values of alpha Q + + align:start position:0% +if there are some values of alpha Q + + + align:start position:0% +if there are some values of alpha Q +which can be uh zero and therefore uh + + align:start position:0% +which can be uh zero and therefore uh + + + align:start position:0% +which can be uh zero and therefore uh +would um mean that those components + + align:start position:0% +would um mean that those components + + + align:start position:0% +would um mean that those components +wouldn't be + + align:start position:0% + + + + align:start position:0% + +there okay so uh so when it gets to the + + align:start position:0% +there okay so uh so when it gets to the + + + align:start position:0% +there okay so uh so when it gets to the +uh to the pupil + + align:start position:0% +uh to the pupil + + + align:start position:0% +uh to the pupil +mask uh all that's happening uh maybe + + align:start position:0% +mask uh all that's happening uh maybe + + + align:start position:0% +mask uh all that's happening uh maybe +you want to go back to + + align:start position:0% +you want to go back to + + + align:start position:0% +you want to go back to +the we go back to + + align:start position:0% +the we go back to + + + align:start position:0% +the we go back to +this diagram uh so you can see that the + + align:start position:0% +this diagram uh so you can see that the + + + align:start position:0% +this diagram uh so you can see that the +um what we what we need to know is this + + align:start position:0% +um what we what we need to know is this + + + align:start position:0% +um what we what we need to know is this +this is coming to a focus at this point + + align:start position:0% +this is coming to a focus at this point + + + align:start position:0% +this is coming to a focus at this point +here but we need to know what that + + align:start position:0% +here but we need to know what that + + + align:start position:0% +here but we need to know what that +distance here is but we need to know um + + align:start position:0% +distance here is but we need to know um + + + align:start position:0% +distance here is but we need to know um +the relative scaling of of where where + + align:start position:0% +the relative scaling of of where where + + + align:start position:0% +the relative scaling of of where where +that defraction order appears + + align:start position:0% + + + + align:start position:0% + +on oh that was what appeared + + align:start position:0% + + + + align:start position:0% + +there okay so it's this is this Lambda F + + align:start position:0% +there okay so it's this is this Lambda F + + + align:start position:0% +there okay so it's this is this Lambda F +that comes in here because it's going + + align:start position:0% +that comes in here because it's going + + + align:start position:0% +that comes in here because it's going +through a distance F so that gives the + + align:start position:0% +through a distance F so that gives the + + + align:start position:0% +through a distance F so that gives the +uh the scaling of this distribution you + + align:start position:0% +uh the scaling of this distribution you + + + align:start position:0% +uh the scaling of this distribution you +get there uh and uh so uh so that's + + align:start position:0% +get there uh and uh so uh so that's + + + align:start position:0% +get there uh and uh so uh so that's +where U now is replaced by this x Double + + align:start position:0% +where U now is replaced by this x Double + + + align:start position:0% +where U now is replaced by this x Double +Dash over Lambda F right the scaling of + + align:start position:0% +Dash over Lambda F right the scaling of + + + align:start position:0% +Dash over Lambda F right the scaling of +that size of that defraction + + align:start position:0% +that size of that defraction + + + align:start position:0% +that size of that defraction +pattern uh and uh and then this is + + align:start position:0% +pattern uh and uh and then this is + + + align:start position:0% +pattern uh and uh and then this is +putting the answer in uh is that you get + + align:start position:0% +putting the answer in uh is that you get + + + align:start position:0% +putting the answer in uh is that you get +this + + align:start position:0% +this + + + align:start position:0% +this +um oh yeah we're told that Alpha is the + + align:start position:0% +um oh yeah we're told that Alpha is the + + + align:start position:0% +um oh yeah we're told that Alpha is the +duty F uh uh cycle the uh so that's the + + align:start position:0% +duty F uh uh cycle the uh so that's the + + + align:start position:0% +duty F uh uh cycle the uh so that's the +third uh so that becomes Alpha is a + + align:start position:0% +third uh so that becomes Alpha is a + + + align:start position:0% +third uh so that becomes Alpha is a +third in + + align:start position:0% +third in + + + align:start position:0% +third in +here + + align:start position:0% +here + + + align:start position:0% +here +uh and where do we get the 1 cm + + align:start position:0% + + + + align:start position:0% + +from yeah I think I saw something like + + align:start position:0% +from yeah I think I saw something like + + + align:start position:0% +from yeah I think I saw something like +this on the crib sheet which you've all + + align:start position:0% +this on the crib sheet which you've all + + + align:start position:0% +this on the crib sheet which you've all +had by the + + align:start position:0% +had by the + + + align:start position:0% +had by the +way + + align:start position:0% +way + + + align:start position:0% +way +uh so we've + + align:start position:0% + + + + align:start position:0% + +got right + + align:start position:0% +got right + + + align:start position:0% +got right +here we've got Lambda equal + + align:start position:0% +here we've got Lambda equal + + + align:start position:0% +here we've got Lambda equal +0.5 + + align:start position:0% +0.5 + + + align:start position:0% +0.5 +microns F = 20 + + align:start position:0% +microns F = 20 + + + align:start position:0% +microns F = 20 +cm + + align:start position:0% +cm + + + align:start position:0% +cm +Lambda period is equal to 10 + + align:start position:0% +Lambda period is equal to 10 + + + align:start position:0% +Lambda period is equal to 10 +microns so that gives that Lambda F over + + align:start position:0% +microns so that gives that Lambda F over + + + align:start position:0% +microns so that gives that Lambda F over +Capital Lambda is + + align:start position:0% +Capital Lambda is + + + align:start position:0% +Capital Lambda is +0.5 uh time + + align:start position:0% +0.5 uh time + + + align:start position:0% +0.5 uh time +20 over + + align:start position:0% +20 over + + + align:start position:0% +20 over + + align:start position:0% + + + align:start position:0% +um um that's not that's this is this is + + align:start position:0% +um um that's not that's this is this is + + + align:start position:0% +um um that's not that's this is this is +microns + + align:start position:0% +microns + + + align:start position:0% +microns +lamb oh yeah that's the these are in + + align:start position:0% +lamb oh yeah that's the these are in + + + align:start position:0% +lamb oh yeah that's the these are in +microns these are in microns these are + + align:start position:0% +microns these are in microns these are + + + align:start position:0% +microns these are in microns these are +in centimet so this is in centimet + + align:start position:0% +in centimet so this is in centimet + + + align:start position:0% +in centimet so this is in centimet +and this is equal to 1 + + align:start position:0% +and this is equal to 1 + + + align:start position:0% +and this is equal to 1 +cm right okay so so that's + + align:start position:0% +cm right okay so so that's + + + align:start position:0% +cm right okay so so that's +the uh what's going on there then so + + align:start position:0% +the uh what's going on there then so + + + align:start position:0% +the uh what's going on there then so +that's the 1 + + align:start position:0% + + + + align:start position:0% + +cm okay that's so that's just plotting + + align:start position:0% +cm okay that's so that's just plotting + + + align:start position:0% +cm okay that's so that's just plotting +then these different + + align:start position:0% +then these different + + + align:start position:0% +then these different +orders uh and so you can see here the + + align:start position:0% +orders uh and so you can see here the + + + align:start position:0% +orders uh and so you can see here the +zero order + one + two plus three so on + + align:start position:0% +zero order + one + two plus three so on + + + align:start position:0% +zero order + one + two plus three so on +uh but uh + + align:start position:0% +uh but uh + + + align:start position:0% +uh but uh +the screen blocks out all the ones + + align:start position:0% +the screen blocks out all the ones + + + align:start position:0% +the screen blocks out all the ones +except for these Central + + align:start position:0% + + + + align:start position:0% + +ones uh and uh so this thing these these + + align:start position:0% +ones uh and uh so this thing these these + + + align:start position:0% +ones uh and uh so this thing these these +relative + + align:start position:0% +relative + + + align:start position:0% +relative +strengths uh must come from well there's + + align:start position:0% +strengths uh must come from well there's + + + align:start position:0% +strengths uh must come from well there's +a the fact of third at the front is this + + align:start position:0% +a the fact of third at the front is this + + + align:start position:0% +a the fact of third at the front is this +one and then this is multiplied by the + + align:start position:0% +one and then this is multiplied by the + + + align:start position:0% +one and then this is multiplied by the +value of SN of of um a third which must + + align:start position:0% +value of SN of of um a third which must + + + align:start position:0% +value of SN of of um a third which must +give this this the rest of this thing + + align:start position:0% +give this this the rest of this thing + + + align:start position:0% +give this this the rest of this thing +here uh um so I have posted in the + + align:start position:0% +here uh um so I have posted in the + + + align:start position:0% +here uh um so I have posted in the +website a supplement to this lecture so + + align:start position:0% +website a supplement to this lecture so + + + align:start position:0% +website a supplement to this lecture so +in the supplement I have worked out all + + align:start position:0% +in the supplement I have worked out all + + + align:start position:0% +in the supplement I have worked out all +these calculations how you compute the + + align:start position:0% +these calculations how you compute the + + + align:start position:0% +these calculations how you compute the +sync of 1/3 sync of two over3 and so on + + align:start position:0% +sync of 1/3 sync of two over3 and so on + + + align:start position:0% +sync of 1/3 sync of two over3 and so on +so you can see some more details in the + + align:start position:0% +so you can see some more details in the + + + align:start position:0% +so you can see some more details in the +in the in the website yeah okay you + + align:start position:0% +in the in the website yeah okay you + + + align:start position:0% +in the in the website yeah okay you +remember sync you've defined as s of pix + + align:start position:0% +remember sync you've defined as s of pix + + + align:start position:0% +remember sync you've defined as s of pix +over pix remember that + + align:start position:0% + + + + align:start position:0% + +um so that's the that's the why that + + align:start position:0% +um so that's the that's the why that + + + align:start position:0% +um so that's the that's the why that +people usually Define it syn of x equal + + align:start position:0% +people usually Define it syn of x equal + + + align:start position:0% +people usually Define it syn of x equal +sin of PX over + + align:start position:0% +sin of PX over + + + align:start position:0% +sin of PX over +pix right + + align:start position:0% + + + + align:start position:0% + +so it's it's it's defined in that way + + align:start position:0% +so it's it's it's defined in that way + + + align:start position:0% +so it's it's it's defined in that way +because then then lots of n nasty pies + + align:start position:0% +because then then lots of n nasty pies + + + align:start position:0% +because then then lots of n nasty pies +and things cancel out and everything + + align:start position:0% +and things cancel out and everything + + + align:start position:0% +and things cancel out and everything +else + + align:start position:0% + + + + align:start position:0% + +okay uh so we got to then multiply that + + align:start position:0% +okay uh so we got to then multiply that + + + align:start position:0% +okay uh so we got to then multiply that +uh by the + + align:start position:0% +uh by the + + + align:start position:0% +uh by the +um the size of the Mask uh so as it + + align:start position:0% +um the size of the Mask uh so as it + + + align:start position:0% +um the size of the Mask uh so as it +shows here the mask going fromus 1.5 cm + + align:start position:0% +shows here the mask going fromus 1.5 cm + + + align:start position:0% +shows here the mask going fromus 1.5 cm +to 1 plus 1.5 CM which means that this + + align:start position:0% +to 1 plus 1.5 CM which means that this + + + align:start position:0% +to 1 plus 1.5 CM which means that this +grating component which is at 2 cm + + align:start position:0% +grating component which is at 2 cm + + + align:start position:0% +grating component which is at 2 cm +doesn't get through right so so that's + + align:start position:0% +doesn't get through right so so that's + + + align:start position:0% +doesn't get through right so so that's +what the what gets through the + + align:start position:0% +what the what gets through the + + + align:start position:0% +what the what gets through the +aperture uh and uh then we for transform + + align:start position:0% +aperture uh and uh then we for transform + + + align:start position:0% +aperture uh and uh then we for transform +that + + align:start position:0% +that + + + align:start position:0% +that +again uh and uh so the Delta function + + align:start position:0% +again uh and uh so the Delta function + + + align:start position:0% +again uh and uh so the Delta function +transforms to an exponential shifted + + align:start position:0% +transforms to an exponential shifted + + + align:start position:0% +transforms to an exponential shifted +Delta function corresponds to + + align:start position:0% + + + + align:start position:0% + +exponential and therefore our output uh + + align:start position:0% +exponential and therefore our output uh + + + align:start position:0% +exponential and therefore our output uh +of course this this F was the same in + + align:start position:0% +of course this this F was the same in + + + align:start position:0% +of course this this F was the same in +this case the two FS of the two two + + align:start position:0% +this case the two FS of the two two + + + align:start position:0% +this case the two FS of the two two +lenses were the same so we get a 1 over + + align:start position:0% +lenses were the same so we get a 1 over + + + align:start position:0% +lenses were the same so we get a 1 over +Lambda f again there + + align:start position:0% +Lambda f again there + + + align:start position:0% +Lambda f again there +R uh what will happen if we make the + + align:start position:0% +R uh what will happen if we make the + + + align:start position:0% +R uh what will happen if we make the +width of the uh this mask uh minus 2 to + + align:start position:0% +width of the uh this mask uh minus 2 to + + + align:start position:0% +width of the uh this mask uh minus 2 to ++2 will there be any deflection due to + + align:start position:0% ++2 will there be any deflection due to + + + align:start position:0% ++2 will there be any deflection due to +this uh second + + align:start position:0% +this uh second + + + align:start position:0% +this uh second +order um well if it was exactly minus 2 + + align:start position:0% +order um well if it was exactly minus 2 + + + align:start position:0% +order um well if it was exactly minus 2 +to plus two yes then uh I guess if it + + align:start position:0% +to plus two yes then uh I guess if it + + + align:start position:0% +to plus two yes then uh I guess if it +really was exactly there you'd expect + + align:start position:0% +really was exactly there you'd expect + + + align:start position:0% +really was exactly there you'd expect +half of it to get through wouldn't you + + align:start position:0% +half of it to get through wouldn't you + + + align:start position:0% +half of it to get through wouldn't you +this order but I mean normally we we we + + align:start position:0% +this order but I mean normally we we we + + + align:start position:0% +this order but I mean normally we we we +would assume it either lets it through + + align:start position:0% +would assume it either lets it through + + + align:start position:0% +would assume it either lets it through +or it doesn't let it through but so if + + align:start position:0% +or it doesn't let it through but so if + + + align:start position:0% +or it doesn't let it through but so if +you let if if you made the the size of + + align:start position:0% +you let if if you made the the size of + + + align:start position:0% +you let if if you made the the size of +the aperture 2 2.5 then of course this + + align:start position:0% +the aperture 2 2.5 then of course this + + + align:start position:0% +the aperture 2 2.5 then of course this +next order would get through wouldn't + + align:start position:0% +next order would get through wouldn't + + + align:start position:0% +next order would get through wouldn't +it yeah but if it is exit will there + + align:start position:0% +it yeah but if it is exit will there + + + align:start position:0% +it yeah but if it is exit will there +means do we have to consider a + + align:start position:0% +means do we have to consider a + + + align:start position:0% +means do we have to consider a +deflection + + align:start position:0% +deflection + + + align:start position:0% +deflection +of uh no I think that basically you know + + align:start position:0% +of uh no I think that basically you know + + + align:start position:0% +of uh no I think that basically you know +I think that effectively you I think + + align:start position:0% +I think that effectively you I think + + + align:start position:0% +I think that effectively you I think +you'd have to say that half of it got + + align:start position:0% +you'd have to say that half of it got + + + align:start position:0% +you'd have to say that half of it got +through and actually that's correct + + align:start position:0% +through and actually that's correct + + + align:start position:0% +through and actually that's correct +because in actuality the Great is finite + + align:start position:0% +because in actuality the Great is finite + + + align:start position:0% +because in actuality the Great is finite +so these are not Delta functions they're + + align:start position:0% +so these are not Delta functions they're + + + align:start position:0% +so these are not Delta functions they're +sync patterns so if you place the grade + + align:start position:0% +sync patterns so if you place the grade + + + align:start position:0% +sync patterns so if you place the grade +in at exactly two then you allow one + + align:start position:0% +in at exactly two then you allow one + + + align:start position:0% +in at exactly two then you allow one +half of the S to go through right so + + align:start position:0% +half of the S to go through right so + + + align:start position:0% +half of the S to go through right so +therefore one half is yeah yeah that's a + + align:start position:0% +therefore one half is yeah yeah that's a + + + align:start position:0% +therefore one half is yeah yeah that's a +very good way of thinking here we + + align:start position:0% +very good way of thinking here we + + + align:start position:0% +very good way of thinking here we +started off by saying that this is a um + + align:start position:0% +started off by saying that this is a um + + + align:start position:0% +started off by saying that this is a um +a continuous a repetitive grating and so + + align:start position:0% +a continuous a repetitive grating and so + + + align:start position:0% +a continuous a repetitive grating and so +we can think of it in terms of a Furious + + align:start position:0% +we can think of it in terms of a Furious + + + align:start position:0% +we can think of it in terms of a Furious +series but of course it's not actually + + align:start position:0% +series but of course it's not actually + + + align:start position:0% +series but of course it's not actually +infinitely + + align:start position:0% +infinitely + + + align:start position:0% +infinitely +big uh I guess it's not going to be more + + align:start position:0% +big uh I guess it's not going to be more + + + align:start position:0% +big uh I guess it's not going to be more +than a few + + align:start position:0% +than a few + + + align:start position:0% +than a few +uh like years across so this is + + align:start position:0% +uh like years across so this is + + + align:start position:0% +uh like years across so this is +multiplied by another rect function + + align:start position:0% +multiplied by another rect function + + + align:start position:0% +multiplied by another rect function +really right so the fora transform of + + align:start position:0% +really right so the fora transform of + + + align:start position:0% +really right so the fora transform of +this whole thing multiplied by re is + + align:start position:0% +this whole thing multiplied by re is + + + align:start position:0% +this whole thing multiplied by re is +something convolved with a sync so each + + align:start position:0% +something convolved with a sync so each + + + align:start position:0% +something convolved with a sync so each +of these these things is not really a + + align:start position:0% +of these these things is not really a + + + align:start position:0% +of these these things is not really a +Delta function but it's really a very + + align:start position:0% +Delta function but it's really a very + + + align:start position:0% +Delta function but it's really a very +narrow sync which depends on the size of + + align:start position:0% +narrow sync which depends on the size of + + + align:start position:0% +narrow sync which depends on the size of +our grating so yeah so the point George + + align:start position:0% +our grating so yeah so the point George + + + align:start position:0% +our grating so yeah so the point George +is making is if you think of it as a + + align:start position:0% +is making is if you think of it as a + + + align:start position:0% +is making is if you think of it as a +sync + + align:start position:0% +sync + + + align:start position:0% +sync +uh then you it really would be letting + + align:start position:0% +uh then you it really would be letting + + + align:start position:0% +uh then you it really would be letting +letting through half of it right um I + + align:start position:0% +letting through half of it right um I + + + align:start position:0% +letting through half of it right um I +think mathematically it have to be like + + align:start position:0% +think mathematically it have to be like + + + align:start position:0% +think mathematically it have to be like +that as well you get used to these when + + align:start position:0% +that as well you get used to these when + + + align:start position:0% +that as well you get used to these when +you do you you must remember from um + + align:start position:0% +you do you you must remember from um + + + align:start position:0% +you do you you must remember from um +solving partial differential equations + + align:start position:0% +solving partial differential equations + + + align:start position:0% +solving partial differential equations +when you do the boundary conditions you + + align:start position:0% +when you do the boundary conditions you + + + align:start position:0% +when you do the boundary conditions you +always have to do that sort of thing uh + + align:start position:0% +always have to do that sort of thing uh + + + align:start position:0% +always have to do that sort of thing uh +it seems a bit of a cheap + + align:start position:0% + + + + align:start position:0% + +but + + align:start position:0% +but + + + align:start position:0% +but +okay okay so this is putting the numbers + + align:start position:0% +okay okay so this is putting the numbers + + + align:start position:0% +okay okay so this is putting the numbers +in then so this is the uh the three + + align:start position:0% +in then so this is the uh the three + + + align:start position:0% +in then so this is the uh the three +components these are these root3 over 2 + + align:start position:0% +components these are these root3 over 2 + + + align:start position:0% +components these are these root3 over 2 +pi we had there uh and uh and then + + align:start position:0% +pi we had there uh and uh and then + + + align:start position:0% +pi we had there uh and uh and then +finally these two combine together to + + align:start position:0% +finally these two combine together to + + + align:start position:0% +finally these two combine together to +make a + + align:start position:0% +make a + + + align:start position:0% +make a +cosine uh and our final uh amplitude of + + align:start position:0% +cosine uh and our final uh amplitude of + + + align:start position:0% +cosine uh and our final uh amplitude of +our image is going to be a constant plus + + align:start position:0% +our image is going to be a constant plus + + + align:start position:0% +our image is going to be a constant plus +a + + align:start position:0% +a + + + align:start position:0% +a +cosine you notice that it's not the the + + align:start position:0% +cosine you notice that it's not the the + + + align:start position:0% +cosine you notice that it's not the the +the amplitude of this is not the same as + + align:start position:0% +the amplitude of this is not the same as + + + align:start position:0% +the amplitude of this is not the same as +the amplitude of that of course because + + align:start position:0% +the amplitude of that of course because + + + align:start position:0% +the amplitude of that of course because +of the uh the fact that it was a + + align:start position:0% +of the uh the fact that it was a + + + align:start position:0% +of the uh the fact that it was a +uh this um um rectangular + + align:start position:0% + + + + align:start position:0% + +grating yeah then finally though uh as I + + align:start position:0% +grating yeah then finally though uh as I + + + align:start position:0% +grating yeah then finally though uh as I +just uh mentioned briefly a little while + + align:start position:0% +just uh mentioned briefly a little while + + + align:start position:0% +just uh mentioned briefly a little while +ago what you actually see is not the + + align:start position:0% +ago what you actually see is not the + + + align:start position:0% +ago what you actually see is not the +amplitude what you see is the + + align:start position:0% +amplitude what you see is the + + + align:start position:0% +amplitude what you see is the +intensity uh which is the modulus square + + align:start position:0% +intensity uh which is the modulus square + + + align:start position:0% +intensity uh which is the modulus square +of the + + align:start position:0% +of the + + + align:start position:0% +of the +amplitude right so uh you remember we + + align:start position:0% +amplitude right so uh you remember we + + + align:start position:0% +amplitude right so uh you remember we +said that what we we normally are going + + align:start position:0% +said that what we we normally are going + + + align:start position:0% +said that what we we normally are going +to call the intensity just the modulus + + align:start position:0% +to call the intensity just the modulus + + + align:start position:0% +to call the intensity just the modulus +square of the amplitude there perhaps + + align:start position:0% +square of the amplitude there perhaps + + + align:start position:0% +square of the amplitude there perhaps +should be some some halves and funny + + align:start position:0% +should be some some halves and funny + + + align:start position:0% +should be some some halves and funny +things out there if we were really doing + + align:start position:0% +things out there if we were really doing + + + align:start position:0% +things out there if we were really doing +it according to uh the pointing Vector + + align:start position:0% +it according to uh the pointing Vector + + + align:start position:0% +it according to uh the pointing Vector +uh but normally we don't bother with + + align:start position:0% +uh but normally we don't bother with + + + align:start position:0% +uh but normally we don't bother with +that we just say is the modulus Square + + align:start position:0% +that we just say is the modulus Square + + + align:start position:0% +that we just say is the modulus Square +so the modulus square of this uh we're + + align:start position:0% +so the modulus square of this uh we're + + + align:start position:0% +so the modulus square of this uh we're +going to get this squared uh and uh + + align:start position:0% +going to get this squared uh and uh + + + align:start position:0% +going to get this squared uh and uh +twice the product of these two and then + + align:start position:0% +twice the product of these two and then + + + align:start position:0% +twice the product of these two and then +this one squared so we get this terming + + align:start position:0% +this one squared so we get this terming + + + align:start position:0% +this one squared so we get this terming +cos + + align:start position:0% +cos + + + align:start position:0% +cos +squar uh and then you have to remember + + align:start position:0% +squar uh and then you have to remember + + + align:start position:0% +squar uh and then you have to remember +your formula uh that you learned in Mass + + align:start position:0% +your formula uh that you learned in Mass + + + align:start position:0% +your formula uh that you learned in Mass +cos 2 Theta = 1 - 2 cosine 2 Theta which + + align:start position:0% +cos 2 Theta = 1 - 2 cosine 2 Theta which + + + align:start position:0% +cos 2 Theta = 1 - 2 cosine 2 Theta which +allows us to write cos s Theta is 1 + + + align:start position:0% +allows us to write cos s Theta is 1 + + + + align:start position:0% +allows us to write cos s Theta is 1 + +cos Theta / 2 uh so this cos squ uh we + + align:start position:0% +cos Theta / 2 uh so this cos squ uh we + + + align:start position:0% +cos Theta / 2 uh so this cos squ uh we +can now replace uh by a constant plus a + + align:start position:0% +can now replace uh by a constant plus a + + + align:start position:0% +can now replace uh by a constant plus a +cosine of twice the angle uh and uh so + + align:start position:0% +cosine of twice the angle uh and uh so + + + align:start position:0% +cosine of twice the angle uh and uh so +that this is the constant + + align:start position:0% +that this is the constant + + + align:start position:0% +that this is the constant +bit uh and this is the cosine of twice + + align:start position:0% +bit uh and this is the cosine of twice + + + align:start position:0% +bit uh and this is the cosine of twice +the angle + + align:start position:0% +the angle + + + align:start position:0% +the angle +right so that likes gives another + + align:start position:0% +right so that likes gives another + + + align:start position:0% +right so that likes gives another +harmonic in the image uh so that's + + align:start position:0% +harmonic in the image uh so that's + + + align:start position:0% +harmonic in the image uh so that's +something that people are a bit confused + + align:start position:0% +something that people are a bit confused + + + align:start position:0% +something that people are a bit confused +by sometimes first of all because we've + + align:start position:0% +by sometimes first of all because we've + + + align:start position:0% +by sometimes first of all because we've +gone through a lot of talk about how + + align:start position:0% +gone through a lot of talk about how + + + align:start position:0% +gone through a lot of talk about how +it's only the first harmonic that's got + + align:start position:0% +it's only the first harmonic that's got + + + align:start position:0% +it's only the first harmonic that's got +through uh but actually now when we look + + align:start position:0% +through uh but actually now when we look + + + align:start position:0% +through uh but actually now when we look +at the + + align:start position:0% +at the + + + align:start position:0% +at the +intensity uh We've now got a second + + align:start position:0% +intensity uh We've now got a second + + + align:start position:0% +intensity uh We've now got a second +harmonic that's that's appearing in the + + align:start position:0% +harmonic that's that's appearing in the + + + align:start position:0% +harmonic that's that's appearing in the +final + + align:start position:0% +final + + + align:start position:0% +final +intensity so note the second harmonic + + align:start position:0% +intensity so note the second harmonic + + + align:start position:0% +intensity so note the second harmonic +term intensity due to the magnitude + + align:start position:0% +term intensity due to the magnitude + + + align:start position:0% +term intensity due to the magnitude +Square operation + + align:start position:0% +Square operation + + + align:start position:0% +Square operation +uh this term explains the ringing in + + align:start position:0% +uh this term explains the ringing in + + + align:start position:0% +uh this term explains the ringing in +coherent low pass filtering systems + + align:start position:0% +coherent low pass filtering systems + + + align:start position:0% +coherent low pass filtering systems +right so yeah so it's + + align:start position:0% +right so yeah so it's + + + align:start position:0% +right so yeah so it's +um the ringing is the the the + + align:start position:0% +um the ringing is the the the + + + align:start position:0% +um the ringing is the the the +um Wiggles you get on a on a sharp + + align:start position:0% +um Wiggles you get on a on a sharp + + + align:start position:0% +um Wiggles you get on a on a sharp +edge right and that's a sketch of what + + align:start position:0% +edge right and that's a sketch of what + + + align:start position:0% +edge right and that's a sketch of what +it looks like uh so it doesn't look + + align:start position:0% +it looks like uh so it doesn't look + + + align:start position:0% +it looks like uh so it doesn't look +quite like a a a cosine grating anymore + + align:start position:0% +quite like a a a cosine grating anymore + + + align:start position:0% +quite like a a a cosine grating anymore +uh because when you Square it the the + + align:start position:0% +uh because when you Square it the the + + + align:start position:0% +uh because when you Square it the the +low values get depressed more uh than + + align:start position:0% +low values get depressed more uh than + + + align:start position:0% +low values get depressed more uh than +the high values right so it become makes + + align:start position:0% +the high values right so it become makes + + + align:start position:0% +the high values right so it become makes +it look more + + align:start position:0% +it look more + + + align:start position:0% +it look more +peaky like + + align:start position:0% + + + + align:start position:0% + +that okay so perhaps we ought to start + + align:start position:0% +that okay so perhaps we ought to start + + + align:start position:0% +that okay so perhaps we ought to start +again I was just waiting for one of our + + align:start position:0% +again I was just waiting for one of our + + + align:start position:0% +again I was just waiting for one of our +people to come back ah well there we are + + align:start position:0% + + + + align:start position:0% + +so just in + + align:start position:0% +so just in + + + align:start position:0% +so just in +time okay so um yeah before we carry on + + align:start position:0% +time okay so um yeah before we carry on + + + align:start position:0% +time okay so um yeah before we carry on +then uh there was a question just before + + align:start position:0% +then uh there was a question just before + + + align:start position:0% +then uh there was a question just before +the break so we're going to have a + + align:start position:0% +the break so we're going to have a + + + align:start position:0% +the break so we're going to have a +question okay actually I have two + + align:start position:0% +question okay actually I have two + + + align:start position:0% +question okay actually I have two +question the first question is regarding + + align:start position:0% +question the first question is regarding + + + align:start position:0% +question the first question is regarding +the physical meaning of the low pass + + align:start position:0% +the physical meaning of the low pass + + + align:start position:0% +the physical meaning of the low pass +filter just now in the previous slide + + align:start position:0% +filter just now in the previous slide + + + align:start position:0% +filter just now in the previous slide +yeah okay so the question is about the + + align:start position:0% +yeah okay so the question is about the + + + align:start position:0% +yeah okay so the question is about the +low pass + + align:start position:0% +low pass + + + align:start position:0% +low pass +filter uh so you you remember in you + + align:start position:0% +filter uh so you you remember in you + + + align:start position:0% +filter uh so you you remember in you +know in um perhaps I'll Draw Something + + align:start position:0% +know in um perhaps I'll Draw Something + + + align:start position:0% +know in um perhaps I'll Draw Something +from uh electronics so you know you you + + align:start position:0% +from uh electronics so you know you you + + + align:start position:0% +from uh electronics so you know you you +remember from uh your high-fi + + align:start position:0% +remember from uh your high-fi + + + align:start position:0% +remember from uh your high-fi +amplifier so this is + + align:start position:0% +amplifier so this is + + + align:start position:0% +amplifier so this is +frequency uh so these These are high + + align:start position:0% +frequency uh so these These are high + + + align:start position:0% +frequency uh so these These are high +frequencies and these are low + + align:start position:0% +frequencies and these are low + + + align:start position:0% +frequencies and these are low +frequencies so um so this corresponds + + align:start position:0% +frequencies so um so this corresponds + + + align:start position:0% +frequencies so um so this corresponds +to and this corresponds + + align:start position:0% +to and this corresponds + + + align:start position:0% +to and this corresponds +to and if we if we multiply this by some + + align:start position:0% +to and if we if we multiply this by some + + + align:start position:0% +to and if we if we multiply this by some +function that looks like that this is + + align:start position:0% +function that looks like that this is + + + align:start position:0% +function that looks like that this is +what we call a low pass filter because + + align:start position:0% +what we call a low pass filter because + + + align:start position:0% +what we call a low pass filter because +we we let through the low low + + align:start position:0% +we we let through the low low + + + align:start position:0% +we we let through the low low +frequencies and we stop the high + + align:start position:0% +frequencies and we stop the high + + + align:start position:0% +frequencies and we stop the high +frequency right um so the same is true + + align:start position:0% +frequency right um so the same is true + + + align:start position:0% +frequency right um so the same is true +here so when we say low low + + align:start position:0% +here so when we say low low + + + align:start position:0% +here so when we say low low +pass uh we we mean that the uh we let + + align:start position:0% +pass uh we we mean that the uh we let + + + align:start position:0% +pass uh we we mean that the uh we let +through the the um the spots which are + + align:start position:0% +through the the um the spots which are + + + align:start position:0% +through the the um the spots which are +close to the axis and stop the ones that + + align:start position:0% +close to the axis and stop the ones that + + + align:start position:0% +close to the axis and stop the ones that +are far from the axis right so that's + + align:start position:0% +are far from the axis right so that's + + + align:start position:0% +are far from the axis right so that's +the first question then there's another + + align:start position:0% +the first question then there's another + + + align:start position:0% +the first question then there's another +one uh the second one is regarding the a + + align:start position:0% +one uh the second one is regarding the a + + + align:start position:0% +one uh the second one is regarding the a +base rule because a Bas rule tell us if + + align:start position:0% +base rule because a Bas rule tell us if + + + align:start position:0% +base rule because a Bas rule tell us if +if we can collect two ERS of the weave + + align:start position:0% +if we can collect two ERS of the weave + + + align:start position:0% +if we can collect two ERS of the weave +we can form one image but just now we + + align:start position:0% +we can form one image but just now we + + + align:start position:0% +we can form one image but just now we +notice that even with the three orders I + + align:start position:0% +notice that even with the three orders I + + + align:start position:0% +notice that even with the three orders I +mean the wave we still get very strange + + align:start position:0% +mean the wave we still get very strange + + + align:start position:0% +mean the wave we still get very strange +weave compared to the original one so I + + align:start position:0% +weave compared to the original one so I + + + align:start position:0% +weave compared to the original one so I +not want to check it what's the reason + + align:start position:0% +not want to check it what's the reason + + + align:start position:0% +not want to check it what's the reason +right okay yeah so um so this is going + + align:start position:0% +right okay yeah so um so this is going + + + align:start position:0% +right okay yeah so um so this is going +back to ABBA's rule which I I I don't + + align:start position:0% +back to ABBA's rule which I I I don't + + + align:start position:0% +back to ABBA's rule which I I I don't +know um I've never really heard what he + + align:start position:0% +know um I've never really heard what he + + + align:start position:0% +know um I've never really heard what he +said actually but have you got that in a + + align:start position:0% +said actually but have you got that in a + + + align:start position:0% +said actually but have you got that in a +book or something it's probably in + + align:start position:0% +book or something it's probably in + + + align:start position:0% +book or something it's probably in +Chinese is it + + align:start position:0% +Chinese is it + + + align:start position:0% +Chinese is it +uh but anyway um the Chinese abber came + + align:start position:0% +uh but anyway um the Chinese abber came + + + align:start position:0% +uh but anyway um the Chinese abber came +up with this rule that you must have at + + align:start position:0% +up with this rule that you must have at + + + align:start position:0% +up with this rule that you must have at +least well we gave an example just now + + align:start position:0% +least well we gave an example just now + + + align:start position:0% +least well we gave an example just now +didn't we of one where you only had one + + align:start position:0% +didn't we of one where you only had one + + + align:start position:0% +didn't we of one where you only had one +beam one order got through and we didn't + + align:start position:0% +beam one order got through and we didn't + + + align:start position:0% +beam one order got through and we didn't +get an image uh so yeah because you're + + align:start position:0% +get an image uh so yeah because you're + + + align:start position:0% +get an image uh so yeah because you're +not obviously not going to get any + + align:start position:0% +not obviously not going to get any + + + align:start position:0% +not obviously not going to get any +interference if you've only got one beam + + align:start position:0% +interference if you've only got one beam + + + align:start position:0% +interference if you've only got one beam +uh so + + align:start position:0% +uh so + + + align:start position:0% +uh so +abbath according to Abba you've got to + + align:start position:0% +abbath according to Abba you've got to + + + align:start position:0% +abbath according to Abba you've got to +have two beams interfering in order to + + align:start position:0% +have two beams interfering in order to + + + align:start position:0% +have two beams interfering in order to +get some variation in in amplitude in + + align:start position:0% +get some variation in in amplitude in + + + align:start position:0% +get some variation in in amplitude in +the image uh and um so he he says at + + align:start position:0% +the image uh and um so he he says at + + + align:start position:0% +the image uh and um so he he says at +least two I guess so uh it could be you + + align:start position:0% +least two I guess so uh it could be you + + + align:start position:0% +least two I guess so uh it could be you +know if you think of these it could be + + align:start position:0% +know if you think of these it could be + + + align:start position:0% +know if you think of these it could be +you could let through the uh we last + + align:start position:0% +you could let through the uh we last + + + align:start position:0% +you could let through the uh we last +time we had the zero and the plus one + + align:start position:0% +time we had the zero and the plus one + + + align:start position:0% +time we had the zero and the plus one +and the minus one uh which is three + + align:start position:0% +and the minus one uh which is three + + + align:start position:0% +and the minus one uh which is three +beams uh and the the point that was made + + align:start position:0% +beams uh and the the point that was made + + + align:start position:0% +beams uh and the the point that was made +in the question was that although we got + + align:start position:0% +in the question was that although we got + + + align:start position:0% +in the question was that although we got +an image it was wasn't a very good image + + align:start position:0% +an image it was wasn't a very good image + + + align:start position:0% +an image it was wasn't a very good image +so um I think that's probably right that + + align:start position:0% +so um I think that's probably right that + + + align:start position:0% +so um I think that's probably right that +that um you know uh I guess Abus + + align:start position:0% +that um you know uh I guess Abus + + + align:start position:0% +that um you know uh I guess Abus +Criterion is is is aba's rule is all to + + align:start position:0% +Criterion is is is aba's rule is all to + + + align:start position:0% +Criterion is is is aba's rule is all to +do with resolution of an optical system + + align:start position:0% +do with resolution of an optical system + + + align:start position:0% +do with resolution of an optical system +the smallest detail you can see but it + + align:start position:0% +the smallest detail you can see but it + + + align:start position:0% +the smallest detail you can see but it +doesn't necessarily mean that you're + + align:start position:0% +doesn't necessarily mean that you're + + + align:start position:0% +doesn't necessarily mean that you're +going to get a good image uh and + + align:start position:0% +going to get a good image uh and + + + align:start position:0% +going to get a good image uh and +changing the relative strengths we're + + align:start position:0% +changing the relative strengths we're + + + align:start position:0% +changing the relative strengths we're +going to see this in lots of examples + + align:start position:0% +going to see this in lots of examples + + + align:start position:0% +going to see this in lots of examples +now actually uh I guess the the whole of + + align:start position:0% +now actually uh I guess the the whole of + + + align:start position:0% +now actually uh I guess the the whole of +the rest of this lecture will be about + + align:start position:0% +the rest of this lecture will be about + + + align:start position:0% +the rest of this lecture will be about +these uh more examples + + align:start position:0% +these uh more examples + + + align:start position:0% +these uh more examples +of stopping beams and so on and changing + + align:start position:0% +of stopping beams and so on and changing + + + align:start position:0% +of stopping beams and so on and changing +beams and seeing what it does to the + + align:start position:0% +beams and seeing what it does to the + + + align:start position:0% +beams and seeing what it does to the +pattern and uh so very often what you'll + + align:start position:0% +pattern and uh so very often what you'll + + + align:start position:0% +pattern and uh so very often what you'll +find then is you get something which may + + align:start position:0% +find then is you get something which may + + + align:start position:0% +find then is you get something which may +be not a good image of the uh original + + align:start position:0% +be not a good image of the uh original + + + align:start position:0% +be not a good image of the uh original +objects but it it's um an image which is + + align:start position:0% +objects but it it's um an image which is + + + align:start position:0% +objects but it it's um an image which is +perhaps better than + + align:start position:0% +perhaps better than + + + align:start position:0% +perhaps better than +nothing okay so is that all right that + + align:start position:0% +nothing okay so is that all right that + + + align:start position:0% +nothing okay so is that all right that +can that answer the + + align:start position:0% +can that answer the + + + align:start position:0% +can that answer the +question okay so we're now looking at a + + align:start position:0% +question okay so we're now looking at a + + + align:start position:0% +question okay so we're now looking at a +a a band pass filter so going back to + + align:start position:0% +a a band pass filter so going back to + + + align:start position:0% +a a band pass filter so going back to +what I was saying here the band pass + + align:start position:0% +what I was saying here the band pass + + + align:start position:0% +what I was saying here the band pass +filter of + + align:start position:0% +filter of + + + align:start position:0% +filter of +course uh is is something that looks + + align:start position:0% +course uh is is something that looks + + + align:start position:0% +course uh is is something that looks +like this it's it a band pass filter uh + + align:start position:0% +like this it's it a band pass filter uh + + + align:start position:0% +like this it's it a band pass filter uh +stops the low frequencies and also the + + align:start position:0% +stops the low frequencies and also the + + + align:start position:0% +stops the low frequencies and also the +high + + align:start position:0% +high + + + align:start position:0% +high +frequencies and so you can see here the + + align:start position:0% +frequencies and so you can see here the + + + align:start position:0% +frequencies and so you can see here the +uh the optical equivalent of this it's + + align:start position:0% +uh the optical equivalent of this it's + + + align:start position:0% +uh the optical equivalent of this it's +now stopping the zero order but allowing + + align:start position:0% +now stopping the zero order but allowing + + + align:start position:0% +now stopping the zero order but allowing +the first orders to get through uh and + + align:start position:0% +the first orders to get through uh and + + + align:start position:0% +the first orders to get through uh and +then the later ones would also uh not + + align:start position:0% +then the later ones would also uh not + + + align:start position:0% +then the later ones would also uh not +get through uh oh yeah that was another + + align:start position:0% +get through uh oh yeah that was another + + + align:start position:0% +get through uh oh yeah that was another +point that George mentioned to me during + + align:start position:0% +point that George mentioned to me during + + + align:start position:0% +point that George mentioned to me during +the break that I hadn't appreciated + + align:start position:0% +the break that I hadn't appreciated + + + align:start position:0% +the break that I hadn't appreciated +fully uh and that is that this + + align:start position:0% +fully uh and that is that this + + + align:start position:0% +fully uh and that is that this +particular example which had this um + + align:start position:0% +particular example which had this um + + + align:start position:0% +particular example which had this um +duty cycle of a + + align:start position:0% +duty cycle of a + + + align:start position:0% +duty cycle of a +third uh actually it turns out that the + + align:start position:0% +third uh actually it turns out that the + + + align:start position:0% +third uh actually it turns out that the +third order of this one vanishes so I + + align:start position:0% +third order of this one vanishes so I + + + align:start position:0% +third order of this one vanishes so I +guess the third the sixth the ninth all + + align:start position:0% +guess the third the sixth the ninth all + + + align:start position:0% +guess the third the sixth the ninth all +these and this is just like we we said + + align:start position:0% +these and this is just like we we said + + + align:start position:0% +these and this is just like we we said +that for a square wave grating all the + + align:start position:0% +that for a square wave grating all the + + + align:start position:0% +that for a square wave grating all the +even orders cancel so it's all to do + + align:start position:0% +even orders cancel so it's all to do + + + align:start position:0% +even orders cancel so it's all to do +with the the zeros of of that sync + + align:start position:0% +with the the zeros of of that sync + + + align:start position:0% +with the the zeros of of that sync +function we had sync of alpha Q right so + + align:start position:0% +function we had sync of alpha Q right so + + + align:start position:0% +function we had sync of alpha Q right so +where Alpha is the duty cycle so for any + + align:start position:0% +where Alpha is the duty cycle so for any + + + align:start position:0% +where Alpha is the duty cycle so for any +duty cycle there will be particular uh + + align:start position:0% +duty cycle there will be particular uh + + + align:start position:0% +duty cycle there will be particular uh +values of the uh + + align:start position:0% +values of the uh + + + align:start position:0% +values of the uh +particular uh integers for the order + + align:start position:0% +particular uh integers for the order + + + align:start position:0% +particular uh integers for the order +which would vanish in the forer + + align:start position:0% +which would vanish in the forer + + + align:start position:0% +which would vanish in the forer +transform right okay so um we here with + + align:start position:0% +transform right okay so um we here with + + + align:start position:0% +transform right okay so um we here with +we're letting through the plus one and + + align:start position:0% +we're letting through the plus one and + + + align:start position:0% +we're letting through the plus one and +the minus + + align:start position:0% + + + + align:start position:0% + +one what did something do + + align:start position:0% + + + + align:start position:0% + +then ah right yeah okay so okay so the + + align:start position:0% +then ah right yeah okay so okay so the + + + align:start position:0% +then ah right yeah okay so okay so the +amplitude is one going to be a 1 plus + + align:start position:0% +amplitude is one going to be a 1 plus + + + align:start position:0% +amplitude is one going to be a 1 plus +cosine uh and intensity we're going to + + align:start position:0% +cosine uh and intensity we're going to + + + align:start position:0% +cosine uh and intensity we're going to +get a second harmonic in it just like we + + align:start position:0% +get a second harmonic in it just like we + + + align:start position:0% +get a second harmonic in it just like we +had with the previous + + align:start position:0% +had with the previous + + + align:start position:0% +had with the previous +case Okay and then we now we're going to + + align:start position:0% +case Okay and then we now we're going to + + + align:start position:0% +case Okay and then we now we're going to +go through this in uh more detail so + + align:start position:0% +go through this in uh more detail so + + + align:start position:0% +go through this in uh more detail so +it's the same grating as before so we + + align:start position:0% +it's the same grating as before so we + + + align:start position:0% +it's the same grating as before so we +haven't got to work out all that stuff + + align:start position:0% +haven't got to work out all that stuff + + + align:start position:0% +haven't got to work out all that stuff +again uh the you remember it was 1 cm + + align:start position:0% +again uh the you remember it was 1 cm + + + align:start position:0% +again uh the you remember it was 1 cm +was where the first order was so we got + + align:start position:0% +was where the first order was so we got + + + align:start position:0% +was where the first order was so we got +this series of these uh um different um + + align:start position:0% +this series of these uh um different um + + + align:start position:0% +this series of these uh um different um +grating + + align:start position:0% +grating + + + align:start position:0% +grating +components and uh these ones are + + align:start position:0% +components and uh these ones are + + + align:start position:0% +components and uh these ones are +zero as I just described the next one + + align:start position:0% +zero as I just described the next one + + + align:start position:0% +zero as I just described the next one +would wouldn't be zero though and and we + + align:start position:0% +would wouldn't be zero though and and we + + + align:start position:0% +would wouldn't be zero though and and we +are putting this mask in which is just + + align:start position:0% +are putting this mask in which is just + + + align:start position:0% +are putting this mask in which is just +going to let through these + + align:start position:0% + + + + align:start position:0% + +two and uh so we mathematically we can + + align:start position:0% +two and uh so we mathematically we can + + + align:start position:0% +two and uh so we mathematically we can +write the mask as being the sum of two + + align:start position:0% +write the mask as being the sum of two + + + align:start position:0% +write the mask as being the sum of two +rectangles rectangle and another + + align:start position:0% + + + + align:start position:0% + +rectangle so then uh it lets through + + align:start position:0% +rectangle so then uh it lets through + + + align:start position:0% +rectangle so then uh it lets through +those two components and stops the + + align:start position:0% +those two components and stops the + + + align:start position:0% +those two components and stops the +others so we got the these two two Delta + + align:start position:0% +others so we got the these two two Delta + + + align:start position:0% +others so we got the these two two Delta +functions and then we just got to do a + + align:start position:0% +functions and then we just got to do a + + + align:start position:0% +functions and then we just got to do a +for a transform again uh each of the + + align:start position:0% +for a transform again uh each of the + + + align:start position:0% +for a transform again uh each of the +Delta functions produces a a a a plain + + align:start position:0% +Delta functions produces a a a a plain + + + align:start position:0% +Delta functions produces a a a a plain +uh wave an a complex + + align:start position:0% + + + + align:start position:0% + +exponential we then got to add those + + align:start position:0% +exponential we then got to add those + + + align:start position:0% +exponential we then got to add those +together well we got to got got to + + align:start position:0% +together well we got to got got to + + + align:start position:0% +together well we got to got got to +change the um um into distance of course + + align:start position:0% +change the um um into distance of course + + + align:start position:0% +change the um um into distance of course +uh and then uh combine these two complex + + align:start position:0% +uh and then uh combine these two complex + + + align:start position:0% +uh and then uh combine these two complex +exponentials to make a cosine and then + + align:start position:0% +exponentials to make a cosine and then + + + align:start position:0% +exponentials to make a cosine and then +finally we've got to square it again in + + align:start position:0% +finally we've got to square it again in + + + align:start position:0% +finally we've got to square it again in +order to get the intensity + + align:start position:0% +order to get the intensity + + + align:start position:0% +order to get the intensity +out and so now notice what we get + + align:start position:0% +out and so now notice what we get + + + align:start position:0% +out and so now notice what we get +now uh you see we get the constant + + align:start position:0% +now uh you see we get the constant + + + align:start position:0% +now uh you see we get the constant +term you see here is just cosine there's + + align:start position:0% +term you see here is just cosine there's + + + align:start position:0% +term you see here is just cosine there's +no constant term anymore because the + + align:start position:0% +no constant term anymore because the + + + align:start position:0% +no constant term anymore because the +constant terms gone so the COS when we + + align:start position:0% +constant terms gone so the COS when we + + + align:start position:0% +constant terms gone so the COS when we +Square it we get cos squar + + align:start position:0% +Square it we get cos squar + + + align:start position:0% +Square it we get cos squar +the COS squ we go into double angles + + align:start position:0% +the COS squ we go into double angles + + + align:start position:0% +the COS squ we go into double angles +again we get a constant plus a + + align:start position:0% +again we get a constant plus a + + + align:start position:0% +again we get a constant plus a +cosine and uh so you see that actually + + align:start position:0% +cosine and uh so you see that actually + + + align:start position:0% +cosine and uh so you see that actually +uh we get an image where the uh first + + align:start position:0% +uh we get an image where the uh first + + + align:start position:0% +uh we get an image where the uh first +harmonic doesn't appear at all but the + + align:start position:0% +harmonic doesn't appear at all but the + + + align:start position:0% +harmonic doesn't appear at all but the +second harmonic does so uh this comes + + align:start position:0% +second harmonic does so uh this comes + + + align:start position:0% +second harmonic does so uh this comes +back to your question in a way uh you + + align:start position:0% +back to your question in a way uh you + + + align:start position:0% +back to your question in a way uh you +end up with getting an image which is + + align:start position:0% +end up with getting an image which is + + + align:start position:0% +end up with getting an image which is +actually really not like the objects + + align:start position:0% +actually really not like the objects + + + align:start position:0% +actually really not like the objects +because you see that this has got twice + + align:start position:0% +because you see that this has got twice + + + align:start position:0% +because you see that this has got twice +the frequency of this + + align:start position:0% +the frequency of this + + + align:start position:0% +the frequency of this +right so uh although Abba uh says that + + align:start position:0% +right so uh although Abba uh says that + + + align:start position:0% +right so uh although Abba uh says that +you can get an image he doesn't say that + + align:start position:0% +you can get an image he doesn't say that + + + align:start position:0% +you can get an image he doesn't say that +you can get a correct image and in this + + align:start position:0% +you can get a correct image and in this + + + align:start position:0% +you can get a correct image and in this +case you could be very confused by this + + align:start position:0% +case you could be very confused by this + + + align:start position:0% +case you could be very confused by this +couldn't you you could look at in your + + align:start position:0% +couldn't you you could look at in your + + + align:start position:0% +couldn't you you could look at in your +microscope at something and you could + + align:start position:0% +microscope at something and you could + + + align:start position:0% +microscope at something and you could +see this uh and uh and you'd be + + align:start position:0% +see this uh and uh and you'd be + + + align:start position:0% +see this uh and uh and you'd be +completely mistaken about the object + + align:start position:0% +completely mistaken about the object + + + align:start position:0% +completely mistaken about the object +that was actually producing this because + + align:start position:0% +that was actually producing this because + + + align:start position:0% +that was actually producing this because +uh it's actually twice as big as what + + align:start position:0% +uh it's actually twice as big as what + + + align:start position:0% +uh it's actually twice as big as what +you + + align:start position:0% +you + + + align:start position:0% +you +expect uh so a question that's oh yeah + + align:start position:0% +expect uh so a question that's oh yeah + + + align:start position:0% +expect uh so a question that's oh yeah +um youen me if you grab just the zero + + align:start position:0% +um youen me if you grab just the zero + + + align:start position:0% +um youen me if you grab just the zero +order and say the first order but not + + align:start position:0% +order and say the first order but not + + + align:start position:0% +order and say the first order but not +the minus one then you get the same + + align:start position:0% +the minus one then you get the same + + + align:start position:0% +the minus one then you get the same +period as the original + + align:start position:0% +period as the original + + + align:start position:0% +period as the original +grading uh the yeah I guess so would + + align:start position:0% +grading uh the yeah I guess so would + + + align:start position:0% +grading uh the yeah I guess so would +that be right George if you take this + + align:start position:0% +that be right George if you take this + + + align:start position:0% +that be right George if you take this +one and this one uh so you got and then + + align:start position:0% +one and this one uh so you got and then + + + align:start position:0% +one and this one uh so you got and then +you square + + align:start position:0% +you square + + + align:start position:0% +you square +it uh you're going to get one plus an e + + align:start position:0% +it uh you're going to get one plus an e + + + align:start position:0% +it uh you're going to get one plus an e +to the I you're going + + align:start position:0% +to the I you're going + + + align:start position:0% +to the I you're going +to uh uh I don't yeah he's working it + + align:start position:0% +to uh uh I don't yeah he's working it + + + align:start position:0% +to uh uh I don't yeah he's working it +out he's working it out we have a race + + align:start position:0% +out he's working it out we have a race + + + align:start position:0% +out he's working it out we have a race +shall we + + align:start position:0% +shall we + + + align:start position:0% +shall we +um you're going to have a 1 plus e to + + align:start position:0% +um you're going to have a 1 plus e to + + + align:start position:0% +um you're going to have a 1 plus e to +the I um something or + + align:start position:0% + + + + align:start position:0% + +other and then this modulus + + align:start position:0% +other and then this modulus + + + align:start position:0% +other and then this modulus +squared so and then you can take out an + + align:start position:0% +squared so and then you can take out an + + + align:start position:0% +squared so and then you can take out an +e to the ey something over two e you got + + align:start position:0% +e to the ey something over two e you got + + + align:start position:0% +e to the ey something over two e you got +the answer yeah + + align:start position:0% + + + + align:start position:0% + +something like that so this is cosine so + + align:start position:0% +something like that so this is cosine so + + + align:start position:0% +something like that so this is cosine so +you're going to end that with cosine + + align:start position:0% +you're going to end that with cosine + + + align:start position:0% +you're going to end that with cosine +squared um it's the same as this isn't + + align:start position:0% +squared um it's the same as this isn't + + + align:start position:0% +squared um it's the same as this isn't +it the image with just with a phase term + + align:start position:0% +it the image with just with a phase term + + + align:start position:0% +it the image with just with a phase term +no it can't be because it's half as far + + align:start position:0% + + + + align:start position:0% + +apart yeah you get the first harmonic + + align:start position:0% +apart yeah you get the first harmonic + + + align:start position:0% +apart yeah you get the first harmonic +yeah because it's the square of half of + + align:start position:0% +yeah because it's the square of half of + + + align:start position:0% +yeah because it's the square of half of +it yeah okay so it's a it's it's double + + align:start position:0% +it yeah okay so it's a it's it's double + + + align:start position:0% +it yeah okay so it's a it's it's double +half of it so you do get the first + + align:start position:0% +half of it so you do get the first + + + align:start position:0% +half of it so you do get the first +harmonic yeah you're quite correct so + + align:start position:0% +harmonic yeah you're quite correct so + + + align:start position:0% +harmonic yeah you're quite correct so +but you know I mean it might work for + + align:start position:0% +but you know I mean it might work for + + + align:start position:0% +but you know I mean it might work for +this object but I guess there' be other + + align:start position:0% +this object but I guess there' be other + + + align:start position:0% +this object but I guess there' be other +objects which it would also uh produce + + align:start position:0% +objects which it would also uh produce + + + align:start position:0% +objects which it would also uh produce +funny results uh and uh and of course as + + align:start position:0% +funny results uh and uh and of course as + + + align:start position:0% +funny results uh and uh and of course as +we know um well some of us know uh most + + align:start position:0% +we know um well some of us know uh most + + + align:start position:0% +we know um well some of us know uh most +of you won't know but for example shalim + + align:start position:0% +of you won't know but for example shalim + + + align:start position:0% +of you won't know but for example shalim +will know uh that if you have uh uh a + + align:start position:0% +will know uh that if you have uh uh a + + + align:start position:0% +will know uh that if you have uh uh a +mask which is uh asymmetric like that + + align:start position:0% +mask which is uh asymmetric like that + + + align:start position:0% +mask which is uh asymmetric like that +it's going to have some quite + + align:start position:0% +it's going to have some quite + + + align:start position:0% +it's going to have some quite +interesting in properties so I don't + + align:start position:0% +interesting in properties so I don't + + + align:start position:0% +interesting in properties so I don't +know whether you go Ono these at some + + align:start position:0% +know whether you go Ono these at some + + + align:start position:0% +know whether you go Ono these at some +later + + align:start position:0% +later + + + align:start position:0% +later +point maybe in the exam okay so all + + align:start position:0% +point maybe in the exam okay so all + + + align:start position:0% +point maybe in the exam okay so all +everyone SWAT up on asymmetric + + align:start position:0% + + + + align:start position:0% + +gratings yeah yes single Side Band + + align:start position:0% +gratings yeah yes single Side Band + + + align:start position:0% +gratings yeah yes single Side Band +modulation yeah um and what's the other + + align:start position:0% +modulation yeah um and what's the other + + + align:start position:0% +modulation yeah um and what's the other +word for it what's this um when they um + + align:start position:0% +word for it what's this um when they um + + + align:start position:0% +word for it what's this um when they um +measure the um flow of the uh in + + align:start position:0% +measure the um flow of the uh in + + + align:start position:0% +measure the um flow of the uh in +aerodynamics scheren schen it's it's + + align:start position:0% +aerodynamics scheren schen it's it's + + + align:start position:0% +aerodynamics scheren schen it's it's +it's basically + + align:start position:0% +it's basically + + + align:start position:0% +it's basically +schen + + align:start position:0% +schen + + + align:start position:0% +schen +okay uh now we're looking at uh tilted + + align:start position:0% +okay uh now we're looking at uh tilted + + + align:start position:0% +okay uh now we're looking at uh tilted +illumination so same sort of system as + + align:start position:0% +illumination so same sort of system as + + + align:start position:0% +illumination so same sort of system as +the last one uh but we're now not + + align:start position:0% +the last one uh but we're now not + + + align:start position:0% +the last one uh but we're now not +Illuminating it with a plane wave along + + align:start position:0% +Illuminating it with a plane wave along + + + align:start position:0% +Illuminating it with a plane wave along +the a axis we're going to tilt this uh + + align:start position:0% +the a axis we're going to tilt this uh + + + align:start position:0% +the a axis we're going to tilt this uh +and um so what we find what do we find + + align:start position:0% +and um so what we find what do we find + + + align:start position:0% +and um so what we find what do we find +if we uh if we got a grating and we + + align:start position:0% +if we uh if we got a grating and we + + + align:start position:0% +if we uh if we got a grating and we +illuminate it with a plain wave + + align:start position:0% +illuminate it with a plain wave + + + align:start position:0% +illuminate it with a plain wave +what what do we find happens if we tilt + + align:start position:0% +what what do we find happens if we tilt + + + align:start position:0% +what what do we find happens if we tilt +the the plane + + align:start position:0% +the the plane + + + align:start position:0% +the the plane +wave have you come across this it was + + align:start position:0% +wave have you come across this it was + + + align:start position:0% +wave have you come across this it was +you did this earlier on did you I don't + + align:start position:0% +you did this earlier on did you I don't + + + align:start position:0% +you did this earlier on did you I don't +think I was there for this one but + + align:start position:0% +think I was there for this one but + + + align:start position:0% +think I was there for this one but +actually all that happens is it just + + align:start position:0% +actually all that happens is it just + + + align:start position:0% +actually all that happens is it just +tilts the defraction pattern very simple + + align:start position:0% +tilts the defraction pattern very simple + + + align:start position:0% +tilts the defraction pattern very simple +uh so you can see now the the zero + + align:start position:0% +uh so you can see now the the zero + + + align:start position:0% +uh so you can see now the the zero +order uh is still in this this + + align:start position:0% +order uh is still in this this + + + align:start position:0% +order uh is still in this this +direction uh and um and all the other + + align:start position:0% +direction uh and um and all the other + + + align:start position:0% +direction uh and um and all the other +orders just move bodily they all rotate + + align:start position:0% +orders just move bodily they all rotate + + + align:start position:0% +orders just move bodily they all rotate +through the same angle this is actually + + align:start position:0% +through the same angle this is actually + + + align:start position:0% +through the same angle this is actually +only true if you can think of this as + + align:start position:0% +only true if you can think of this as + + + align:start position:0% +only true if you can think of this as +being a thin + + align:start position:0% +being a thin + + + align:start position:0% +being a thin +grating and uh you know if you if you go + + align:start position:0% +grating and uh you know if you if you go + + + align:start position:0% +grating and uh you know if you if you go +into a theory of volume Holograms and + + align:start position:0% +into a theory of volume Holograms and + + + align:start position:0% +into a theory of volume Holograms and +things like that then you'll find that + + align:start position:0% +things like that then you'll find that + + + align:start position:0% +things like that then you'll find that +Things become much more complicated the + + align:start position:0% +Things become much more complicated the + + + align:start position:0% +Things become much more complicated the +relative strengths of the grading can + + align:start position:0% +relative strengths of the grading can + + + align:start position:0% +relative strengths of the grading can +change and so on but if this is a a thin + + align:start position:0% +change and so on but if this is a a thin + + + align:start position:0% +change and so on but if this is a a thin +grading so that you can uh use this uh + + align:start position:0% +grading so that you can uh use this uh + + + align:start position:0% +grading so that you can uh use this uh +property that you just multiply by the + + align:start position:0% +property that you just multiply by the + + + align:start position:0% +property that you just multiply by the +transm transmission of the Great + + align:start position:0% +transm transmission of the Great + + + align:start position:0% +transm transmission of the Great +uh then that will be the case uh so you + + align:start position:0% +uh then that will be the case uh so you + + + align:start position:0% +uh then that will be the case uh so you +can see what that's going to do all the + + align:start position:0% +can see what that's going to do all the + + + align:start position:0% +can see what that's going to do all the +gratings move up uh which means that + + align:start position:0% +gratings move up uh which means that + + + align:start position:0% +gratings move up uh which means that +they all get moved up there as well so + + align:start position:0% +they all get moved up there as well so + + + align:start position:0% +they all get moved up there as well so +the uh you see the zero order + + align:start position:0% +the uh you see the zero order + + + align:start position:0% +the uh you see the zero order +grating which was appearing down at the + + align:start position:0% +grating which was appearing down at the + + + align:start position:0% +grating which was appearing down at the +origin uh is now tilted upwards uh and + + align:start position:0% +origin uh is now tilted upwards uh and + + + align:start position:0% +origin uh is now tilted upwards uh and +appears at this point here so with this + + align:start position:0% +appears at this point here so with this + + + align:start position:0% +appears at this point here so with this +band pass filter uh that we've chosen uh + + align:start position:0% +band pass filter uh that we've chosen uh + + + align:start position:0% +band pass filter uh that we've chosen uh +we now get the zero order through so + + align:start position:0% +we now get the zero order through so + + + align:start position:0% +we now get the zero order through so +we're getting the the zero order + + align:start position:0% +we're getting the the zero order + + + align:start position:0% +we're getting the the zero order +through through this one and we get in + + align:start position:0% +through through this one and we get in + + + align:start position:0% +through through this one and we get in +the minus two order through this + + align:start position:0% + + + + align:start position:0% + +one right so it's we illuminate it with + + align:start position:0% +one right so it's we illuminate it with + + + align:start position:0% +one right so it's we illuminate it with +a uh uh we illiminate the grating with + + align:start position:0% +a uh uh we illiminate the grating with + + + align:start position:0% +a uh uh we illiminate the grating with +an off-axis plane wave at an angle of + + align:start position:0% +an off-axis plane wave at an angle of + + + align:start position:0% +an off-axis plane wave at an angle of +2.86 + + align:start position:0% +2.86 + + + align:start position:0% +2.86 +5° uh which is is obviously uh very + + align:start position:0% +5° uh which is is obviously uh very + + + align:start position:0% +5° uh which is is obviously uh very +carefully designed uh so that this this + + align:start position:0% +carefully designed uh so that this this + + + align:start position:0% +carefully designed uh so that this this +grazing this gracing order moves from + + align:start position:0% +grazing this gracing order moves from + + + align:start position:0% +grazing this gracing order moves from +it's + + align:start position:0% +it's + + + align:start position:0% +it's +here + + align:start position:0% +here + + + align:start position:0% +here +uh so what + + align:start position:0% + + + + align:start position:0% + +happens okay so yeah so it's just + + align:start position:0% +happens okay so yeah so it's just + + + align:start position:0% +happens okay so yeah so it's just +describing uh what what I just + + align:start position:0% +describing uh what what I just + + + align:start position:0% +describing uh what what I just +said um yeah this is just describing why + + align:start position:0% +said um yeah this is just describing why + + + align:start position:0% +said um yeah this is just describing why +that happens then in terms of um + + align:start position:0% +that happens then in terms of um + + + align:start position:0% +that happens then in terms of um +multiplying the um + + align:start position:0% +multiplying the um + + + align:start position:0% +multiplying the um +the the uh you see this tilted wave is + + align:start position:0% +the the uh you see this tilted wave is + + + align:start position:0% +the the uh you see this tilted wave is +just going to have a a + + align:start position:0% +just going to have a a + + + align:start position:0% +just going to have a a +complex + + align:start position:0% +complex + + + align:start position:0% +complex +uh a complex exponential phase variation + + align:start position:0% +uh a complex exponential phase variation + + + align:start position:0% +uh a complex exponential phase variation +like this so you multiply that by the + + align:start position:0% +like this so you multiply that by the + + + align:start position:0% +like this so you multiply that by the +grating uh and then the the uh it's just + + align:start position:0% +grating uh and then the the uh it's just + + + align:start position:0% +grating uh and then the the uh it's just +as this result of rotating the + + align:start position:0% + + + + align:start position:0% + +thing okay so um so there there are the + + align:start position:0% +thing okay so um so there there are the + + + align:start position:0% +thing okay so um so there there are the +rating + + align:start position:0% +rating + + + align:start position:0% +rating +orders uh the zero order one uh is this + + align:start position:0% +orders uh the zero order one uh is this + + + align:start position:0% +orders uh the zero order one uh is this +one uh and this is the plus and minus + + align:start position:0% +one uh and this is the plus and minus + + + align:start position:0% +one uh and this is the plus and minus +one and the plus and minus + + align:start position:0% +one and the plus and minus + + + align:start position:0% +one and the plus and minus +two uh and uh so we get let through + + align:start position:0% +two uh and uh so we get let through + + + align:start position:0% +two uh and uh so we get let through +those two so this is a bit like um so + + align:start position:0% +those two so this is a bit like um so + + + align:start position:0% +those two so this is a bit like um so +we're now letting through the uh the + + align:start position:0% +we're now letting through the uh the + + + align:start position:0% +we're now letting through the uh the +we're letting through the zero order and + + align:start position:0% +we're letting through the zero order and + + + align:start position:0% +we're letting through the zero order and +the minus two order uh so it's a bit + + align:start position:0% +the minus two order uh so it's a bit + + + align:start position:0% +the minus two order uh so it's a bit +like the the one in the question but uh + + align:start position:0% +like the the one in the question but uh + + + align:start position:0% +like the the one in the question but uh +but now it's the minus two order not the + + align:start position:0% +but now it's the minus two order not the + + + align:start position:0% +but now it's the minus two order not the +plus the not the minus one order uh so + + align:start position:0% +plus the not the minus one order uh so + + + align:start position:0% +plus the not the minus one order uh so +this is going to be another example + + align:start position:0% +this is going to be another example + + + align:start position:0% +this is going to be another example +where it doesn't give a very good image + + align:start position:0% +where it doesn't give a very good image + + + align:start position:0% +where it doesn't give a very good image +I think from that + + align:start position:0% +I think from that + + + align:start position:0% +I think from that +result uh okay + + align:start position:0% +result uh okay + + + align:start position:0% +result uh okay +so + + align:start position:0% +so + + + align:start position:0% +so +um yeah that's just + + align:start position:0% + + + + align:start position:0% + +really right here we are so it's it's 1 + + align:start position:0% +really right here we are so it's it's 1 + + + align:start position:0% +really right here we are so it's it's 1 +cm the the + + align:start position:0% +cm the the + + + align:start position:0% +cm the the +um the magic figure that magic angle was + + align:start position:0% +um the magic figure that magic angle was + + + align:start position:0% +um the magic figure that magic angle was +designed so that they're all shifted by + + align:start position:0% +designed so that they're all shifted by + + + align:start position:0% +designed so that they're all shifted by + + align:start position:0% + + + + align:start position:0% + +cm so after passing through the mask we + + align:start position:0% +cm so after passing through the mask we + + + align:start position:0% +cm so after passing through the mask we +just get those two + + align:start position:0% +just get those two + + + align:start position:0% +just get those two +components uh and so these are the two + + align:start position:0% +components uh and so these are the two + + + align:start position:0% +components uh and so these are the two +components uh oh yeah + + align:start position:0% +components uh oh yeah + + + align:start position:0% +components uh oh yeah +so ah but they no it isn't yeah that's + + align:start position:0% +so ah but they no it isn't yeah that's + + + align:start position:0% +so ah but they no it isn't yeah that's +right because there're still ah so it's + + align:start position:0% +right because there're still ah so it's + + + align:start position:0% +right because there're still ah so it's +bit more complicated than what I was ah + + align:start position:0% +bit more complicated than what I was ah + + + align:start position:0% +bit more complicated than what I was ah +It's Tricky this so not only of course + + align:start position:0% +It's Tricky this so not only of course + + + align:start position:0% +It's Tricky this so not only of course +uh do we let through the the zero order + + align:start position:0% +uh do we let through the the zero order + + + align:start position:0% +uh do we let through the the zero order +and the minus two order but those orders + + align:start position:0% +and the minus two order but those orders + + + align:start position:0% +and the minus two order but those orders +have got this complex phase shift is + + align:start position:0% +have got this complex phase shift is + + + align:start position:0% +have got this complex phase shift is +that + + align:start position:0% + + + + align:start position:0% + +right + + align:start position:0% + + + + align:start position:0% + +um yeah exactly exactly because of the + + align:start position:0% +um yeah exactly exactly because of the + + + align:start position:0% +um yeah exactly exactly because of the +pH because of the yeah okay so that's + + align:start position:0% +pH because of the yeah okay so that's + + + align:start position:0% +pH because of the yeah okay so that's +what I'm same so although this is a a + + align:start position:0% +what I'm same so although this is a a + + + align:start position:0% +what I'm same so although this is a a +zero order and aus2 order they're + + align:start position:0% +zero order and aus2 order they're + + + align:start position:0% +zero order and aus2 order they're +actually shifted uh and so when you do + + align:start position:0% +actually shifted uh and so when you do + + + align:start position:0% +actually shifted uh and so when you do +the fer transform uh + + align:start position:0% +the fer transform uh + + + align:start position:0% +the fer transform uh +they're they're just as though they were + + align:start position:0% +they're they're just as though they were + + + align:start position:0% +they're they're just as though they were +the plus one and the minus one order + + align:start position:0% +the plus one and the minus one order + + + align:start position:0% +the plus one and the minus one order +that's neat very + + align:start position:0% +that's neat very + + + align:start position:0% +that's neat very +interesting but with different + + align:start position:0% +interesting but with different + + + align:start position:0% +interesting but with different +amplitudes given by these two strengths + + align:start position:0% +amplitudes given by these two strengths + + + align:start position:0% +amplitudes given by these two strengths +here + + align:start position:0% + + + + align:start position:0% + +right uh and then uh so um + + align:start position:0% +right uh and then uh so um + + + align:start position:0% +right uh and then uh so um +yeah so then then we have to um put the + + align:start position:0% +yeah so then then we have to um put the + + + align:start position:0% +yeah so then then we have to um put the +values of U in terms of the X and then + + align:start position:0% +values of U in terms of the X and then + + + align:start position:0% +values of U in terms of the X and then +we combine the two exponentials well we + + align:start position:0% +we combine the two exponentials well we + + + align:start position:0% +we combine the two exponentials well we +can't do that anymore can we oh yes we + + align:start position:0% +can't do that anymore can we oh yes we + + + align:start position:0% +can't do that anymore can we oh yes we +can + + align:start position:0% + + + + align:start position:0% + +uh uh yeah exactly so how have you how + + align:start position:0% +uh uh yeah exactly so how have you how + + + align:start position:0% +uh uh yeah exactly so how have you how +have you actually done that + + align:start position:0% + + + + align:start position:0% + +then right so you got to do the the the + + align:start position:0% +then right so you got to do the the the + + + align:start position:0% +then right so you got to do the the the +modulus square of this so you're going + + align:start position:0% +modulus square of this so you're going + + + align:start position:0% +modulus square of this so you're going +to have this squared plus this squared + + align:start position:0% +to have this squared plus this squared + + + align:start position:0% +to have this squared plus this squared +oh yeah okay so that of course you are + + align:start position:0% +oh yeah okay so that of course you are + + + align:start position:0% +oh yeah okay so that of course you are +so then twice the products of these + + align:start position:0% +so then twice the products of these + + + align:start position:0% +so then twice the products of these +two uh and um + + align:start position:0% +two uh and um + + + align:start position:0% +two uh and um +okay that right uh no sorry that's not + + align:start position:0% +okay that right uh no sorry that's not + + + align:start position:0% +okay that right uh no sorry that's not +right is + + align:start position:0% + + + + align:start position:0% + +it yeah that's right + + align:start position:0% +it yeah that's right + + + align:start position:0% +it yeah that's right +yeah yeah yeah + + align:start position:0% + + + + align:start position:0% + +okay and this is what it looks like + + align:start position:0% +okay and this is what it looks like + + + align:start position:0% +okay and this is what it looks like +T so uh okay so the field is the first + + align:start position:0% +T so uh okay so the field is the first + + + align:start position:0% +T so uh okay so the field is the first +harmonic the intensity is the second + + align:start position:0% +harmonic the intensity is the second + + + align:start position:0% +harmonic the intensity is the second +harmonic because of the squaring and the + + align:start position:0% +harmonic because of the squaring and the + + + align:start position:0% +harmonic because of the squaring and the +contrast is + + align:start position:0% +contrast is + + + align:start position:0% +contrast is +.7 right so again we end up with a bad + + align:start position:0% +.7 right so again we end up with a bad + + + align:start position:0% +.7 right so again we end up with a bad +image because it's shifted uh because + + align:start position:0% +image because it's shifted uh because + + + align:start position:0% +image because it's shifted uh because +it's double frequency and also the + + align:start position:0% +it's double frequency and also the + + + align:start position:0% +it's double frequency and also the +contrast is reduced in this case because + + align:start position:0% +contrast is reduced in this case because + + + align:start position:0% +contrast is reduced in this case because +the strength of the two beams was not + + align:start position:0% +the strength of the two beams was not + + + align:start position:0% +the strength of the two beams was not +the same + + align:start position:0% +the same + + + align:start position:0% +the same +uh this is calculating here the contrast + + align:start position:0% +uh this is calculating here the contrast + + + align:start position:0% +uh this is calculating here the contrast +this is the normal definition of + + align:start position:0% +this is the normal definition of + + + align:start position:0% +this is the normal definition of +contrast of + + align:start position:0% +contrast of + + + align:start position:0% +contrast of +fringes uh the difference over the + + align:start position:0% +fringes uh the difference over the + + + align:start position:0% +fringes uh the difference over the +sum uh and it comes to 7062 the previous + + align:start position:0% +sum uh and it comes to 7062 the previous + + + align:start position:0% +sum uh and it comes to 7062 the previous +case of course it was uh the contrast + + align:start position:0% +case of course it was uh the contrast + + + align:start position:0% +case of course it was uh the contrast +was + + align:start position:0% + + + + align:start position:0% + +one right another example a new pupil + + align:start position:0% +one right another example a new pupil + + + align:start position:0% +one right another example a new pupil +mask consisting of two holes each of Di + + align:start position:0% +mask consisting of two holes each of Di + + + align:start position:0% +mask consisting of two holes each of Di +1 cm and centered further away from the + + align:start position:0% +1 cm and centered further away from the + + + align:start position:0% +1 cm and centered further away from the +axis at plus orus 2 cm from the optical + + align:start position:0% +axis at plus orus 2 cm from the optical + + + align:start position:0% +axis at plus orus 2 cm from the optical +axis respectively what is the intensity + + align:start position:0% +axis respectively what is the intensity + + + align:start position:0% +axis respectively what is the intensity +observed at the output image plane right + + align:start position:0% +observed at the output image plane right + + + align:start position:0% +observed at the output image plane right +so at least it's told us the 2 cm we + + align:start position:0% +so at least it's told us the 2 cm we + + + align:start position:0% +so at least it's told us the 2 cm we +know where that is we don't have to + + align:start position:0% +know where that is we don't have to + + + align:start position:0% +know where that is we don't have to +worry about working out what + + align:start position:0% +worry about working out what + + + align:start position:0% +worry about working out what +3479 degrees is uh we know that the the + + align:start position:0% +3479 degrees is uh we know that the the + + + align:start position:0% +3479 degrees is uh we know that the the +first one first uh order was at 1 C CM + + align:start position:0% +first one first uh order was at 1 C CM + + + align:start position:0% +first one first uh order was at 1 C CM +so uh this this is the second order is + + align:start position:0% +so uh this this is the second order is + + + align:start position:0% +so uh this this is the second order is +where the aperture is so the second + + align:start position:0% +where the aperture is so the second + + + align:start position:0% +where the aperture is so the second +order is going to get through the plus + + align:start position:0% +order is going to get through the plus + + + align:start position:0% +order is going to get through the plus +two and the minus + + align:start position:0% + + + + align:start position:0% + +two uh and did that did that appear then + + align:start position:0% +two uh and did that did that appear then + + + align:start position:0% +two uh and did that did that appear then +up there right okay so the second + + align:start position:0% +up there right okay so the second + + + align:start position:0% +up there right okay so the second +harmonic is going to get through and + + align:start position:0% +harmonic is going to get through and + + + align:start position:0% +harmonic is going to get through and +when you do the square of that you're + + align:start position:0% +when you do the square of that you're + + + align:start position:0% +when you do the square of that you're +going to get the fourth Harmony + + align:start position:0% + + + + align:start position:0% + +uh so this is going through the mass of + + align:start position:0% +uh so this is going through the mass of + + + align:start position:0% +uh so this is going through the mass of +that then uh so we got these just these + + align:start position:0% +that then uh so we got these just these + + + align:start position:0% +that then uh so we got these just these +two + + align:start position:0% +two + + + align:start position:0% +two +components um so these have now got two + + align:start position:0% +components um so these have now got two + + + align:start position:0% +components um so these have now got two +cm in rather than 1 + + align:start position:0% +cm in rather than 1 + + + align:start position:0% +cm in rather than 1 +cm uh so that means that you get a two + + align:start position:0% +cm uh so that means that you get a two + + + align:start position:0% +cm uh so that means that you get a two +multiplied in here that wasn't there + + align:start position:0% +multiplied in here that wasn't there + + + align:start position:0% +multiplied in here that wasn't there +before uh so that's the where the + + align:start position:0% +before uh so that's the where the + + + align:start position:0% +before uh so that's the where the +um second harmonic comes in and then + + align:start position:0% +um second harmonic comes in and then + + + align:start position:0% +um second harmonic comes in and then +when you do the square again you're only + + align:start position:0% +when you do the square again you're only + + + align:start position:0% +when you do the square again you're only +going to get the cosine and no constant + + align:start position:0% +going to get the cosine and no constant + + + align:start position:0% +going to get the cosine and no constant +term and then you do cos squar and + + align:start position:0% +term and then you do cos squar and + + + align:start position:0% +term and then you do cos squar and +change that into uh double angles or for + + align:start position:0% +change that into uh double angles or for + + + align:start position:0% +change that into uh double angles or for +four angles actually uh and now we're + + align:start position:0% +four angles actually uh and now we're + + + align:start position:0% +four angles actually uh and now we're +going to see what it looks like uh and + + align:start position:0% +going to see what it looks like uh and + + + align:start position:0% +going to see what it looks like uh and +now it's it's even worse an image of + + align:start position:0% +now it's it's even worse an image of + + + align:start position:0% +now it's it's even worse an image of +what we wanted so this I guess this is + + align:start position:0% +what we wanted so this I guess this is + + + align:start position:0% +what we wanted so this I guess this is +mainly telling us what we shouldn't do + + align:start position:0% +mainly telling us what we shouldn't do + + + align:start position:0% +mainly telling us what we shouldn't do +rather than what we should do yeah + + align:start position:0% +rather than what we should do yeah + + + align:start position:0% +rather than what we should do yeah +another question uh is this still + + align:start position:0% +another question uh is this still + + + align:start position:0% +another question uh is this still +assuming F1 equals FS2 and what happens + + align:start position:0% +assuming F1 equals FS2 and what happens + + + align:start position:0% +assuming F1 equals FS2 and what happens +if FS2 is smaller than F1 + + align:start position:0% +if FS2 is smaller than F1 + + + align:start position:0% +if FS2 is smaller than F1 +uh all it would do if you change the + + align:start position:0% +uh all it would do if you change the + + + align:start position:0% +uh all it would do if you change the +relative values of F and F1 and F2 all + + align:start position:0% +relative values of F and F1 and F2 all + + + align:start position:0% +relative values of F and F1 and F2 all +it would do uh is is is change the the + + align:start position:0% +it would do uh is is is change the the + + + align:start position:0% +it would do uh is is is change the the +size of the final image right if you if + + align:start position:0% +size of the final image right if you if + + + align:start position:0% +size of the final image right if you if +you think about this system um let's go + + align:start position:0% +you think about this system um let's go + + + align:start position:0% +you think about this system um let's go +back to one where it shows that here we + + align:start position:0% +back to one where it shows that here we + + + align:start position:0% +back to one where it shows that here we +are uh you can see that um it's only the + + align:start position:0% +are uh you can see that um it's only the + + + align:start position:0% +are uh you can see that um it's only the +relative sizes of the the rest relative + + align:start position:0% +relative sizes of the the rest relative + + + align:start position:0% +relative sizes of the the rest relative +distances uh from the + + align:start position:0% +distances uh from the + + + align:start position:0% +distances uh from the +axis uh + + align:start position:0% +axis uh + + + align:start position:0% +axis uh +only depend on the this part of the + + align:start position:0% +only depend on the this part of the + + + align:start position:0% +only depend on the this part of the +optical system and then after the after + + align:start position:0% +optical system and then after the after + + + align:start position:0% +optical system and then after the after +the the pupil mask we've already decided + + align:start position:0% +the the pupil mask we've already decided + + + align:start position:0% +the the pupil mask we've already decided +then what orders get into the final + + align:start position:0% +then what orders get into the final + + + align:start position:0% +then what orders get into the final +image uh and then the final part all + + align:start position:0% +image uh and then the final part all + + + align:start position:0% +image uh and then the final part all +that's going to do is just change the + + align:start position:0% +that's going to do is just change the + + + align:start position:0% +that's going to do is just change the +relative size of the final image you see + + align:start position:0% +relative size of the final image you see + + + align:start position:0% +relative size of the final image you see +yeah + + align:start position:0% + + + + align:start position:0% + +right now we're going to do another bit + + align:start position:0% +right now we're going to do another bit + + + align:start position:0% +right now we're going to do another bit +more complicated one a phase pupil + + align:start position:0% +more complicated one a phase pupil + + + align:start position:0% +more complicated one a phase pupil +mask uh and so what is what this is + + align:start position:0% +mask uh and so what is what this is + + + align:start position:0% +mask uh and so what is what this is +shown as uh is you can see it's got a an + + align:start position:0% +shown as uh is you can see it's got a an + + + align:start position:0% +shown as uh is you can see it's got a an +opaque part of the screen here uh and + + align:start position:0% +opaque part of the screen here uh and + + + align:start position:0% +opaque part of the screen here uh and +then in the central part it's it's + + align:start position:0% +then in the central part it's it's + + + align:start position:0% +then in the central part it's it's +transparent uh but it's got some uh some + + align:start position:0% +transparent uh but it's got some uh some + + + align:start position:0% +transparent uh but it's got some uh some +sort of structure there uh some some + + align:start position:0% +sort of structure there uh some some + + + align:start position:0% +sort of structure there uh some some +diffractive uh dialect element which + + align:start position:0% +diffractive uh dialect element which + + + align:start position:0% +diffractive uh dialect element which +changes the relative phase of this + + align:start position:0% +changes the relative phase of this + + + align:start position:0% +changes the relative phase of this +order compared with the other + + align:start position:0% +order compared with the other + + + align:start position:0% +order compared with the other +orders uh so the question is what's that + + align:start position:0% +orders uh so the question is what's that + + + align:start position:0% +orders uh so the question is what's that +going to do to your your your image uh + + align:start position:0% +going to do to your your your image uh + + + align:start position:0% +going to do to your your your image uh +so the rest of the system is completely + + align:start position:0% +so the rest of the system is completely + + + align:start position:0% +so the rest of the system is completely +the + + align:start position:0% + + + + align:start position:0% + +same uh so this is this is what we're + + align:start position:0% +same uh so this is this is what we're + + + align:start position:0% +same uh so this is this is what we're +considering putting in there uh it + + align:start position:0% +considering putting in there uh it + + + align:start position:0% +considering putting in there uh it +doesn't matter what the thickness of + + align:start position:0% +doesn't matter what the thickness of + + + align:start position:0% +doesn't matter what the thickness of +this is because all that's going to do + + align:start position:0% +this is because all that's going to do + + + align:start position:0% +this is because all that's going to do +is change the relative phase of all of + + align:start position:0% +is change the relative phase of all of + + + align:start position:0% +is change the relative phase of all of +these so it won't affect how they + + align:start position:0% +these so it won't affect how they + + + align:start position:0% +these so it won't affect how they +interfere with each other it just Chang + + align:start position:0% +interfere with each other it just Chang + + + align:start position:0% +interfere with each other it just Chang +the phase of the final image which you + + align:start position:0% +the phase of the final image which you + + + align:start position:0% +the phase of the final image which you +don't see anyway uh but what is + + align:start position:0% +don't see anyway uh but what is + + + align:start position:0% +don't see anyway uh but what is +important uh is this bit here uh the + + align:start position:0% +important uh is this bit here uh the + + + align:start position:0% +important uh is this bit here uh the +thickness of this uh s equal .25 + + align:start position:0% +thickness of this uh s equal .25 + + + align:start position:0% +thickness of this uh s equal .25 +microns uh and the wavelength was half + + align:start position:0% +microns uh and the wavelength was half + + + align:start position:0% +microns uh and the wavelength was half +of5 + + align:start position:0% +of5 + + + align:start position:0% +of5 +microns uh so that's Lambda by two uh so + + align:start position:0% +microns uh so that's Lambda by two uh so + + + align:start position:0% +microns uh so that's Lambda by two uh so +that means changes the phase uh it by + + align:start position:0% +that means changes the phase uh it by + + + align:start position:0% +that means changes the phase uh it by +180° right + + align:start position:0% +180° right + + + align:start position:0% +180° right +so M ah n minus one + + align:start position:0% +so M ah n minus one + + + align:start position:0% +so M ah n minus one +uh oh yeah n minus one so it's not going + + align:start position:0% +uh oh yeah n minus one so it's not going + + + align:start position:0% +uh oh yeah n minus one so it's not going +to do that take it back okay it's Pi by + + align:start position:0% +to do that take it back okay it's Pi by + + + align:start position:0% +to do that take it back okay it's Pi by +twoing right okay uh + + align:start position:0% +twoing right okay uh + + + align:start position:0% +twoing right okay uh +so okay this is known as a phase pupil + + align:start position:0% +so okay this is known as a phase pupil + + + align:start position:0% +so okay this is known as a phase pupil +mask or a pupil phase mask or a mask + + align:start position:0% +mask or a pupil phase mask or a mask + + + align:start position:0% +mask or a pupil phase mask or a mask +pupil + + align:start position:0% + + + + align:start position:0% + +phe yeah it yeah that's right so that + + align:start position:0% +phe yeah it yeah that's right so that + + + align:start position:0% +phe yeah it yeah that's right so that +must be in the next lecture because it's + + align:start position:0% +must be in the next lecture because it's + + + align:start position:0% +must be in the next lecture because it's +not in this one uh so that is getting on + + align:start position:0% +not in this one uh so that is getting on + + + align:start position:0% +not in this one uh so that is getting on +to the real applications okay so George + + align:start position:0% +to the real applications okay so George + + + align:start position:0% +to the real applications okay so George +George said that I would have just + + align:start position:0% +George said that I would have just + + + align:start position:0% +George said that I would have just +failed the exam uh because I I forgot + + align:start position:0% +failed the exam uh because I I forgot + + + align:start position:0% +failed the exam uh because I I forgot +the minus one so of course this light + + align:start position:0% +the minus one so of course this light + + + align:start position:0% +the minus one so of course this light +this light goes through the glass but + + align:start position:0% +this light goes through the glass but + + + align:start position:0% +this light goes through the glass but +this light goes through the glass and + + align:start position:0% +this light goes through the glass and + + + align:start position:0% +this light goes through the glass and +then the air right so to work out the + + align:start position:0% +then the air right so to work out the + + + align:start position:0% +then the air right so to work out the +relative phases of these you have to uh + + align:start position:0% +relative phases of these you have to uh + + + align:start position:0% +relative phases of these you have to uh +look at the relative uh change in the + + align:start position:0% +look at the relative uh change in the + + + align:start position:0% +look at the relative uh change in the +refractive index times the optical + + align:start position:0% +refractive index times the optical + + + align:start position:0% +refractive index times the optical +thickness right so um this is 0.25 + + align:start position:0% +thickness right so um this is 0.25 + + + align:start position:0% +thickness right so um this is 0.25 +microns uh and um this is a025 microns + + align:start position:0% +microns uh and um this is a025 microns + + + align:start position:0% +microns uh and um this is a025 microns +divided by the wavelength and it's going + + align:start position:0% +divided by the wavelength and it's going + + + align:start position:0% +divided by the wavelength and it's going +to be multiplied by 1.5 minus uh one so + + align:start position:0% +to be multiplied by 1.5 minus uh one so + + + align:start position:0% +to be multiplied by 1.5 minus uh one so +this is assuming it's glass uh so uh + + align:start position:0% +this is assuming it's glass uh so uh + + + align:start position:0% +this is assuming it's glass uh so uh +this means that the uh phase change is + + align:start position:0% +this means that the uh phase change is + + + align:start position:0% +this means that the uh phase change is +pi over + + align:start position:0% +pi over + + + align:start position:0% +pi over +two right so not not Pi but pi over + + align:start position:0% + + + + align:start position:0% + +two okay so exactly the same grating + + align:start position:0% +two okay so exactly the same grating + + + align:start position:0% +two okay so exactly the same grating +these are all the + + align:start position:0% + + + + align:start position:0% + +orders uh and uh so you now you see um + + align:start position:0% +orders uh and uh so you now you see um + + + align:start position:0% +orders uh and uh so you now you see um +first of all we get rid of these outer + + align:start position:0% +first of all we get rid of these outer + + + align:start position:0% +first of all we get rid of these outer +ones we let through just these three uh + + align:start position:0% +ones we let through just these three uh + + + align:start position:0% +ones we let through just these three uh +but of those uh we're also going to to + + align:start position:0% +but of those uh we're also going to to + + + align:start position:0% +but of those uh we're also going to to +uh change the relative phase uh of this + + align:start position:0% +uh change the relative phase uh of this + + + align:start position:0% +uh change the relative phase uh of this +one relative to the other two that + + align:start position:0% +one relative to the other two that + + + align:start position:0% +one relative to the other two that +doesn't matter of course if you uh in + + align:start position:0% +doesn't matter of course if you uh in + + + align:start position:0% +doesn't matter of course if you uh in +your sum whether you change the the + + align:start position:0% +your sum whether you change the the + + + align:start position:0% +your sum whether you change the the +phase of this or you change the phase of + + align:start position:0% +phase of this or you change the phase of + + + align:start position:0% +phase of this or you change the phase of +the other two it's only the relative + + align:start position:0% +the other two it's only the relative + + + align:start position:0% +the other two it's only the relative +phase uh which is the important + + align:start position:0% +phase uh which is the important + + + align:start position:0% +phase uh which is the important +thing okay + + align:start position:0% +thing okay + + + align:start position:0% +thing okay +so + + align:start position:0% + + + + align:start position:0% + +uh okay so these are the three + + align:start position:0% +uh okay so these are the three + + + align:start position:0% +uh okay so these are the three +conditions then for the ones that are + + align:start position:0% +conditions then for the ones that are + + + align:start position:0% +conditions then for the ones that are +not don't get through at all the + + align:start position:0% +not don't get through at all the + + + align:start position:0% +not don't get through at all the +strength of those is zero then is here + + align:start position:0% +strength of those is zero then is here + + + align:start position:0% +strength of those is zero then is here +we're taking this these ones to be of + + align:start position:0% +we're taking this these ones to be of + + + align:start position:0% +we're taking this these ones to be of +strength + + align:start position:0% +strength + + + align:start position:0% +strength +one and this one in the center uh to be + + align:start position:0% +one and this one in the center uh to be + + + align:start position:0% +one and this one in the center uh to be +a strength of e to the + + align:start position:0% +a strength of e to the + + + align:start position:0% +a strength of e to the +if5 uh and uh we know that e to the uh + + align:start position:0% +if5 uh and uh we know that e to the uh + + + align:start position:0% +if5 uh and uh we know that e to the uh +we know that f is pi/ 2 so this is e to + + align:start position:0% +we know that f is pi/ 2 so this is e to + + + align:start position:0% +we know that f is pi/ 2 so this is e to +the I pi over 2 uh which is just I is + + align:start position:0% +the I pi over 2 uh which is just I is + + + align:start position:0% +the I pi over 2 uh which is just I is +that + + align:start position:0% +that + + + align:start position:0% +that +right um why have we got this IUS one + + align:start position:0% + + + + align:start position:0% + +then so one way to write this pupil + + align:start position:0% +then so one way to write this pupil + + + align:start position:0% +then so one way to write this pupil +function is as a rect that is as big as + + align:start position:0% +function is as a rect that is as big as + + + align:start position:0% +function is as a rect that is as big as +the opening yeah yeah okay sorry yeah um + + align:start position:0% +the opening yeah yeah okay sorry yeah um + + + align:start position:0% +the opening yeah yeah okay sorry yeah um +so yeah so you can think of this as + + align:start position:0% +so yeah so you can think of this as + + + align:start position:0% +so yeah so you can think of this as +being um uh the whole thing uh uh the + + align:start position:0% +being um uh the whole thing uh uh the + + + align:start position:0% +being um uh the whole thing uh uh the +minus well this this this on top of the + + align:start position:0% +minus well this this this on top of the + + + align:start position:0% +minus well this this this on top of the +whole rectangle right otherwise you'd + + align:start position:0% +whole rectangle right otherwise you'd + + + align:start position:0% +whole rectangle right otherwise you'd +have to do this little bit of rectangle + + align:start position:0% +have to do this little bit of rectangle + + + align:start position:0% +have to do this little bit of rectangle +and this bit of rectangle and this bit + + align:start position:0% +and this bit of rectangle and this bit + + + align:start position:0% +and this bit of rectangle and this bit +of rectangle there three things so you + + align:start position:0% +of rectangle there three things so you + + + align:start position:0% +of rectangle there three things so you +could do it either of those ways I guess + + align:start position:0% +could do it either of those ways I guess + + + align:start position:0% +could do it either of those ways I guess +but the way that George has said done it + + align:start position:0% +but the way that George has said done it + + + align:start position:0% +but the way that George has said done it +here it's the rectangle the whole lot + + align:start position:0% +here it's the rectangle the whole lot + + + align:start position:0% +here it's the rectangle the whole lot +it's all of this uh minus the central + + align:start position:0% +it's all of this uh minus the central + + + align:start position:0% +it's all of this uh minus the central +one plus the central one with the phase + + align:start position:0% +one plus the central one with the phase + + + align:start position:0% +one plus the central one with the phase +change right so that's the minus the one + + align:start position:0% +change right so that's the minus the one + + + align:start position:0% +change right so that's the minus the one +that's not there plus the one that is + + align:start position:0% +that's not there plus the one that is + + + align:start position:0% +that's not there plus the one that is +there with a phase change + + align:start position:0% +there with a phase change + + + align:start position:0% +there with a phase change +and uh yeah so now we we well of course + + align:start position:0% +and uh yeah so now we we well of course + + + align:start position:0% +and uh yeah so now we we well of course +we still + + align:start position:0% +we still + + + align:start position:0% +we still +get uh all these Delta functions but now + + align:start position:0% +get uh all these Delta functions but now + + + align:start position:0% +get uh all these Delta functions but now +we've got some eyes coming + + align:start position:0% +we've got some eyes coming + + + align:start position:0% +we've got some eyes coming +in sorry just one ey just one eye yeah + + align:start position:0% +in sorry just one ey just one eye yeah + + + align:start position:0% +in sorry just one ey just one eye yeah +uh and uh and then uh these two combin + + align:start position:0% +uh and uh and then uh these two combin + + + align:start position:0% +uh and uh and then uh these two combin +to produce cosine still I guess if you + + align:start position:0% +to produce cosine still I guess if you + + + align:start position:0% +to produce cosine still I guess if you +change the pH of one relative to the + + align:start position:0% +change the pH of one relative to the + + + align:start position:0% +change the pH of one relative to the +other it' be more complicated uh but if + + align:start position:0% +other it' be more complicated uh but if + + + align:start position:0% +other it' be more complicated uh but if +these two produce a cosine so we've got + + align:start position:0% +these two produce a cosine so we've got + + + align:start position:0% +these two produce a cosine so we've got +an i plus a + + align:start position:0% +an i plus a + + + align:start position:0% +an i plus a +cosine uh and then we do the modulus + + align:start position:0% +cosine uh and then we do the modulus + + + align:start position:0% +cosine uh and then we do the modulus +square of that uh and the modulus square + + align:start position:0% +square of that uh and the modulus square + + + align:start position:0% +square of that uh and the modulus square +of that of course is um you're not going + + align:start position:0% +of that of course is um you're not going + + + align:start position:0% +of that of course is um you're not going +to get a cross product term are you + + align:start position:0% +to get a cross product term are you + + + align:start position:0% +to get a cross product term are you +because these two uh are in Phase + + align:start position:0% +because these two uh are in Phase + + + align:start position:0% +because these two uh are in Phase +quadrature so when you do the modulus + + align:start position:0% +quadrature so when you do the modulus + + + align:start position:0% +quadrature so when you do the modulus +Square uh you're only going to is that + + align:start position:0% +Square uh you're only going to is that + + + align:start position:0% +Square uh you're only going to is that +right yeah you're going to get this + + align:start position:0% +right yeah you're going to get this + + + align:start position:0% +right yeah you're going to get this +squar plus this squared and this squared + + align:start position:0% +squar plus this squared and this squared + + + align:start position:0% +squar plus this squared and this squared +you can write as these two + + align:start position:0% +you can write as these two + + + align:start position:0% +you can write as these two +terms uh when you do the the double + + align:start position:0% +terms uh when you do the the double + + + align:start position:0% +terms uh when you do the the double +angle and I guess the next one we're + + align:start position:0% +angle and I guess the next one we're + + + align:start position:0% +angle and I guess the next one we're +going to see what it looks like T this + + align:start position:0% +going to see what it looks like T this + + + align:start position:0% +going to see what it looks like T this +is what it looks like uh first harmonic + + align:start position:0% +is what it looks like uh first harmonic + + + align:start position:0% +is what it looks like uh first harmonic +in field second harmonic in intensity + + align:start position:0% +in field second harmonic in intensity + + + align:start position:0% +in field second harmonic in intensity +because of the + + align:start position:0% +because of the + + + align:start position:0% +because of the +squarey uh and again the contrast is now + + align:start position:0% +squarey uh and again the contrast is now + + + align:start position:0% +squarey uh and again the contrast is now +much reduced actually in this case uh + + align:start position:0% +much reduced actually in this case uh + + + align:start position:0% +much reduced actually in this case uh +down to + + align:start position:0% +down to + + + align:start position:0% +down to +0.25 um so I guess this hasn't turned + + align:start position:0% +0.25 um so I guess this hasn't turned + + + align:start position:0% +0.25 um so I guess this hasn't turned +out to be a very good strategy this this + + align:start position:0% +out to be a very good strategy this this + + + align:start position:0% +out to be a very good strategy this this +lecture seems to be mainly showing you + + align:start position:0% +lecture seems to be mainly showing you + + + align:start position:0% +lecture seems to be mainly showing you +what you shouldn't do when you make your + + align:start position:0% + + + + align:start position:0% + +microscope okay uh right + + align:start position:0% +microscope okay uh right + + + align:start position:0% +microscope okay uh right +so uh so now we're going to go on to + + align:start position:0% +so uh so now we're going to go on to + + + align:start position:0% +so uh so now we're going to go on to +think of this in terms of um what we + + align:start position:0% +think of this in terms of um what we + + + align:start position:0% +think of this in terms of um what we +call a point spread function of the low + + align:start position:0% +call a point spread function of the low + + + align:start position:0% +call a point spread function of the low +pass filter so do you remember that um + + align:start position:0% +pass filter so do you remember that um + + + align:start position:0% +pass filter so do you remember that um +going back to our analogies with + + align:start position:0% +going back to our analogies with + + + align:start position:0% +going back to our analogies with +electronics uh we can think of in + + align:start position:0% +electronics uh we can think of in + + + align:start position:0% +electronics uh we can think of in +electronics we think of um you can + + align:start position:0% +electronics we think of um you can + + + align:start position:0% +electronics we think of um you can +either think + + align:start position:0% +either think + + + align:start position:0% +either think +of you you think of your high-fi + + align:start position:0% +of you you think of your high-fi + + + align:start position:0% +of you you think of your high-fi +amplifier as being like a black box + + align:start position:0% +amplifier as being like a black box + + + align:start position:0% +amplifier as being like a black box +don't you and you put in something and + + align:start position:0% +don't you and you put in something and + + + align:start position:0% +don't you and you put in something and +you get out + + align:start position:0% +you get out + + + align:start position:0% +you get out +something uh and you can either think of + + align:start position:0% +something uh and you can either think of + + + align:start position:0% +something uh and you can either think of +what happens inside there as being like + + align:start position:0% +what happens inside there as being like + + + align:start position:0% +what happens inside there as being like +a h of T an Impulse response or you can + + align:start position:0% +a h of T an Impulse response or you can + + + align:start position:0% +a h of T an Impulse response or you can +think of it as being a um a a frequency + + align:start position:0% +think of it as being a um a a frequency + + + align:start position:0% +think of it as being a um a a frequency +response right so uh there are two two + + align:start position:0% +response right so uh there are two two + + + align:start position:0% +response right so uh there are two two +different ways of thinking about this + + align:start position:0% +different ways of thinking about this + + + align:start position:0% +different ways of thinking about this +black box the same is true in this case + + align:start position:0% +black box the same is true in this case + + + align:start position:0% +black box the same is true in this case +so up until now we've been thinking of + + align:start position:0% +so up until now we've been thinking of + + + align:start position:0% +so up until now we've been thinking of +this in terms of uh the frequency + + align:start position:0% +this in terms of uh the frequency + + + align:start position:0% +this in terms of uh the frequency +response what frequencies get into the + + align:start position:0% +response what frequencies get into the + + + align:start position:0% +response what frequencies get into the +image uh and now we're going to think of + + align:start position:0% +image uh and now we're going to think of + + + align:start position:0% +image uh and now we're going to think of +what that means in terms of the point + + align:start position:0% +what that means in terms of the point + + + align:start position:0% +what that means in terms of the point +spread function we've come across the + + align:start position:0% +spread function we've come across the + + + align:start position:0% +spread function we've come across the +point spread function before of course + + align:start position:0% +point spread function before of course + + + align:start position:0% +point spread function before of course +uh so um so we can the point spread + + align:start position:0% +uh so um so we can the point spread + + + align:start position:0% +uh so um so we can the point spread +function is + + align:start position:0% +function is + + + align:start position:0% +function is +basically uh the image of a point object + + align:start position:0% +basically uh the image of a point object + + + align:start position:0% +basically uh the image of a point object +object and our Point objects we make by + + align:start position:0% +object and our Point objects we make by + + + align:start position:0% +object and our Point objects we make by +having a screen with a very small hole + + align:start position:0% +having a screen with a very small hole + + + align:start position:0% +having a screen with a very small hole +in right so this then is going to + + align:start position:0% +in right so this then is going to + + + align:start position:0% +in right so this then is going to +expand + + align:start position:0% +expand + + + align:start position:0% +expand +uh re reach the lens it's going to be + + align:start position:0% +uh re reach the lens it's going to be + + + align:start position:0% +uh re reach the lens it's going to be +cated because we've assumed this to be + + align:start position:0% +cated because we've assumed this to be + + + align:start position:0% +cated because we've assumed this to be +on the + + align:start position:0% +on the + + + align:start position:0% +on the +axis uh this cated + + align:start position:0% +axis uh this cated + + + align:start position:0% +axis uh this cated +beam excuse me uh is going to arrive at + + align:start position:0% +beam excuse me uh is going to arrive at + + + align:start position:0% +beam excuse me uh is going to arrive at +our pupil mask part of this cated beam + + align:start position:0% +our pupil mask part of this cated beam + + + align:start position:0% +our pupil mask part of this cated beam +is going to go through the aperture it's + + align:start position:0% +is going to go through the aperture it's + + + align:start position:0% +is going to go through the aperture it's +going to get to a lens uh it's then + + align:start position:0% +going to get to a lens uh it's then + + + align:start position:0% +going to get to a lens uh it's then +going to be focused down uh and produce + + align:start position:0% +going to be focused down uh and produce + + + align:start position:0% +going to be focused down uh and produce +a uh a converging wave to form a a spot + + align:start position:0% +a uh a converging wave to form a a spot + + + align:start position:0% +a uh a converging wave to form a a spot +on the + + align:start position:0% +on the + + + align:start position:0% +on the +screen right so this is what we think of + + align:start position:0% +screen right so this is what we think of + + + align:start position:0% +screen right so this is what we think of +as uh the final spot is going to be what + + align:start position:0% +as uh the final spot is going to be what + + + align:start position:0% +as uh the final spot is going to be what +we call the point spread function uh h + + align:start position:0% +we call the point spread function uh h + + + align:start position:0% +we call the point spread function uh h +of + + align:start position:0% + + + + align:start position:0% + +XY okay so how do we uh how do we work + + align:start position:0% +XY okay so how do we uh how do we work + + + align:start position:0% +XY okay so how do we uh how do we work +out this point spread function + + align:start position:0% +out this point spread function + + + align:start position:0% +out this point spread function +uh so what we do is we can again work + + align:start position:0% +uh so what we do is we can again work + + + align:start position:0% +uh so what we do is we can again work +through this system in terms of forer + + align:start position:0% +through this system in terms of forer + + + align:start position:0% +through this system in terms of forer +transforms this is a Delta function so + + align:start position:0% +transforms this is a Delta function so + + + align:start position:0% +transforms this is a Delta function so +the fer transform of a Delta function is + + align:start position:0% +the fer transform of a Delta function is + + + align:start position:0% +the fer transform of a Delta function is +just a constant we multiply the constant + + align:start position:0% +just a constant we multiply the constant + + + align:start position:0% +just a constant we multiply the constant +uh by the pupil + + align:start position:0% +uh by the pupil + + + align:start position:0% +uh by the pupil +mask uh and uh and then we got another + + align:start position:0% +mask uh and uh and then we got another + + + align:start position:0% +mask uh and uh and then we got another +system here uh which does another fer + + align:start position:0% +system here uh which does another fer + + + align:start position:0% +system here uh which does another fer +transform uh so what what we're going to + + align:start position:0% +transform uh so what what we're going to + + + align:start position:0% +transform uh so what what we're going to +get uh in the in the plane the image of + + align:start position:0% +get uh in the in the plane the image of + + + align:start position:0% +get uh in the in the plane the image of +a point object is going to be the fer + + align:start position:0% +a point object is going to be the fer + + + align:start position:0% +a point object is going to be the fer +transform of the pupil + + align:start position:0% +transform of the pupil + + + align:start position:0% +transform of the pupil +mask uh and uh yeah so it makes the + + align:start position:0% +mask uh and uh yeah so it makes the + + + align:start position:0% +mask uh and uh yeah so it makes the +point here that we have to be careful of + + align:start position:0% +point here that we have to be careful of + + + align:start position:0% +point here that we have to be careful of +course how we scale things uh and of + + align:start position:0% +course how we scale things uh and of + + + align:start position:0% +course how we scale things uh and of +course the scaling uh is going to depend + + align:start position:0% +course the scaling uh is going to depend + + + align:start position:0% +course the scaling uh is going to depend +on the relative sizes of these F1 and F2 + + align:start position:0% +on the relative sizes of these F1 and F2 + + + align:start position:0% +on the relative sizes of these F1 and F2 +as well of course + + align:start position:0% + + + + align:start position:0% + +right so example if we got the low pass + + align:start position:0% +right so example if we got the low pass + + + align:start position:0% +right so example if we got the low pass +filter right so zero is in the center it + + align:start position:0% +filter right so zero is in the center it + + + align:start position:0% +filter right so zero is in the center it +lets through the low frequencies stops + + align:start position:0% +lets through the low frequencies stops + + + align:start position:0% +lets through the low frequencies stops +the outer + + align:start position:0% +the outer + + + align:start position:0% +the outer +frequencies uh so this is the uh this is + + align:start position:0% +frequencies uh so this is the uh this is + + + align:start position:0% +frequencies uh so this is the uh this is +the uh pupil mask what does the point + + align:start position:0% +the uh pupil mask what does the point + + + align:start position:0% +the uh pupil mask what does the point +spread function of that uh + + align:start position:0% +spread function of that uh + + + align:start position:0% +spread function of that uh +give uh and + + align:start position:0% +give uh and + + + align:start position:0% +give uh and +um so we're assuming that the input uh + + align:start position:0% +um so we're assuming that the input uh + + + align:start position:0% +um so we're assuming that the input uh +uh the input transparency is Delta X IE + + align:start position:0% +uh the input transparency is Delta X IE + + + align:start position:0% +uh the input transparency is Delta X IE +on the axis so this is illuminated on + + align:start position:0% +on the axis so this is illuminated on + + + align:start position:0% +on the axis so this is illuminated on +axis uh the field after the uh after the + + align:start position:0% +axis uh the field after the uh after the + + + align:start position:0% +axis uh the field after the uh after the +pupil mask is just the same as the as + + align:start position:0% +pupil mask is just the same as the as + + + align:start position:0% +pupil mask is just the same as the as +the pupil mask uh and then we FIA + + align:start position:0% +the pupil mask uh and then we FIA + + + align:start position:0% +the pupil mask uh and then we FIA +transform that and it's going to give uh + + align:start position:0% +transform that and it's going to give uh + + + align:start position:0% +transform that and it's going to give uh +a syn the fer Transformer of rect is + + align:start position:0% +a syn the fer Transformer of rect is + + + align:start position:0% +a syn the fer Transformer of rect is +sync uh and uh and here we've got the + + align:start position:0% +sync uh and uh and here we've got the + + + align:start position:0% +sync uh and uh and here we've got the +the relative sizes of this as well uh so + + align:start position:0% +the relative sizes of this as well uh so + + + align:start position:0% +the relative sizes of this as well uh so +that we know how big it is + + align:start position:0% + + + + align:start position:0% + +uh and uh so the amplitude point spread + + align:start position:0% +uh and uh so the amplitude point spread + + + align:start position:0% +uh and uh so the amplitude point spread +function then is is the is this thing + + align:start position:0% +function then is is the is this thing + + + align:start position:0% +function then is is the is this thing +this for transform uh + + align:start position:0% +this for transform uh + + + align:start position:0% +this for transform uh +rescaled with this x- over Lambda F we + + align:start position:0% +rescaled with this x- over Lambda F we + + + align:start position:0% +rescaled with this x- over Lambda F we +replace the U by the x- over Lambda F uh + + align:start position:0% +replace the U by the x- over Lambda F uh + + + align:start position:0% +replace the U by the x- over Lambda F uh +and this finally then is our + + align:start position:0% + + + + align:start position:0% + +answer uh + + align:start position:0% +answer uh + + + align:start position:0% +answer uh +and that uh + + align:start position:0% + + + + align:start position:0% + +um what which three which three times is + + align:start position:0% +um what which three which three times is + + + align:start position:0% +um what which three which three times is +it saying there this this three is that + + align:start position:0% +it saying there this this three is that + + + align:start position:0% +it saying there this this three is that +what that three yeah yeah okay yeah of + + align:start position:0% +what that three yeah yeah okay yeah of + + + align:start position:0% +what that three yeah yeah okay yeah of +course the um energy has to be conserved + + align:start position:0% +course the um energy has to be conserved + + + align:start position:0% +course the um energy has to be conserved +by this thing so you remember there's + + align:start position:0% +by this thing so you remember there's + + + align:start position:0% +by this thing so you remember there's +this theorem in for a transforms again + + align:start position:0% +this theorem in for a transforms again + + + align:start position:0% +this theorem in for a transforms again +that says the area under the uh function + + align:start position:0% +that says the area under the uh function + + + align:start position:0% +that says the area under the uh function +squared is equal to the area under the + + align:start position:0% +squared is equal to the area under the + + + align:start position:0% +squared is equal to the area under the +fora transform squared right so it's + + align:start position:0% +fora transform squared right so it's + + + align:start position:0% +fora transform squared right so it's +it's conservation of + + align:start position:0% +it's conservation of + + + align:start position:0% +it's conservation of +energy uh and um so this is the + + align:start position:0% +energy uh and um so this is the + + + align:start position:0% +energy uh and um so this is the +amplitude point spread function uh it's + + align:start position:0% +amplitude point spread function uh it's + + + align:start position:0% +amplitude point spread function uh it's +sync uh so it goes negative syn sync is + + align:start position:0% +sync uh so it goes negative syn sync is + + + align:start position:0% +sync uh so it goes negative syn sync is +sin pix over pix so it goes negative so + + align:start position:0% +sin pix over pix so it goes negative so + + + align:start position:0% +sin pix over pix so it goes negative so +that's why it's plotted here this is + + align:start position:0% +that's why it's plotted here this is + + + align:start position:0% +that's why it's plotted here this is +zero okay it Wiggles up and down above + + align:start position:0% +zero okay it Wiggles up and down above + + + align:start position:0% +zero okay it Wiggles up and down above +uh zero uh the zero + + align:start position:0% + + + + align:start position:0% + +L uh and uh so what you'd actually see + + align:start position:0% +L uh and uh so what you'd actually see + + + align:start position:0% +L uh and uh so what you'd actually see +of course if you looked at the image of + + align:start position:0% +of course if you looked at the image of + + + align:start position:0% +of course if you looked at the image of +a point object you'd see the modulus + + align:start position:0% +a point object you'd see the modulus + + + align:start position:0% +a point object you'd see the modulus +square of this wouldn't you right just + + align:start position:0% +square of this wouldn't you right just + + + align:start position:0% +square of this wouldn't you right just +like when we looked at our examples of + + align:start position:0% +like when we looked at our examples of + + + align:start position:0% +like when we looked at our examples of +um the + + align:start position:0% +um the + + + align:start position:0% +um the +gratings uh we we we finally look at the + + align:start position:0% +gratings uh we we we finally look at the + + + align:start position:0% +gratings uh we we we finally look at the +actual intensity rather than the + + align:start position:0% +actual intensity rather than the + + + align:start position:0% +actual intensity rather than the +amplitude the intensity of course is + + align:start position:0% +amplitude the intensity of course is + + + align:start position:0% +amplitude the intensity of course is +always positive uh so you'd actually be + + align:start position:0% +always positive uh so you'd actually be + + + align:start position:0% +always positive uh so you'd actually be +looking at the square of that but if + + align:start position:0% +looking at the square of that but if + + + align:start position:0% +looking at the square of that but if +you're trying so think of this thing as + + align:start position:0% +you're trying so think of this thing as + + + align:start position:0% +you're trying so think of this thing as +being um you know what we're going to + + align:start position:0% +being um you know what we're going to + + + align:start position:0% +being um you know what we're going to +carry on to say of course is in Furious + + align:start position:0% +carry on to say of course is in Furious + + + align:start position:0% +carry on to say of course is in Furious +space uh fuor domain uh the spatial + + align:start position:0% +space uh fuor domain uh the spatial + + + align:start position:0% +space uh fuor domain uh the spatial +frequencies of the object are multiplied + + align:start position:0% +frequencies of the object are multiplied + + + align:start position:0% +frequencies of the object are multiplied +by the + + align:start position:0% +by the + + + align:start position:0% +by the +mask in in in terms of of uh this of um + + align:start position:0% +mask in in in terms of of uh this of um + + + align:start position:0% +mask in in in terms of of uh this of um +uh real space you're going to get a + + align:start position:0% +uh real space you're going to get a + + + align:start position:0% +uh real space you're going to get a +convolution the product becomes a + + align:start position:0% +convolution the product becomes a + + + align:start position:0% +convolution the product becomes a +convolution so we're going to convolve + + align:start position:0% +convolution so we're going to convolve + + + align:start position:0% +convolution so we're going to convolve +our objects with an with an amplitude + + align:start position:0% +our objects with an with an amplitude + + + align:start position:0% +our objects with an with an amplitude +point spread function right so but we + + align:start position:0% +point spread function right so but we + + + align:start position:0% +point spread function right so but we +have to do it with the amplitude point + + align:start position:0% +have to do it with the amplitude point + + + align:start position:0% +have to do it with the amplitude point +spread function find the find the total + + align:start position:0% +spread function find the find the total + + + align:start position:0% +spread function find the find the total +amplitude in the image and then do the + + align:start position:0% +amplitude in the image and then do the + + + align:start position:0% +amplitude in the image and then do the +modular Square uh to find the final + + align:start position:0% +modular Square uh to find the final + + + align:start position:0% +modular Square uh to find the final +intensity okay and this is an example of + + align:start position:0% +intensity okay and this is an example of + + + align:start position:0% +intensity okay and this is an example of +the point spread function of this um + + align:start position:0% +the point spread function of this um + + + align:start position:0% +the point spread function of this um +face filter we looked at uh the the + + align:start position:0% +face filter we looked at uh the the + + + align:start position:0% +face filter we looked at uh the the +pupil mask this is the same as we had + + align:start position:0% +pupil mask this is the same as we had + + + align:start position:0% +pupil mask this is the same as we had +before uh so it's this is its modulus + + align:start position:0% +before uh so it's this is its modulus + + + align:start position:0% +before uh so it's this is its modulus +this is the phase uh and uh if you + + align:start position:0% +this is the phase uh and uh if you + + + align:start position:0% +this is the phase uh and uh if you +calculate the point spread function of + + align:start position:0% +calculate the point spread function of + + + align:start position:0% +calculate the point spread function of +this it comes to this this is the + + align:start position:0% +this it comes to this this is the + + + align:start position:0% +this it comes to this this is the +modulus this is the phase uh so you can + + align:start position:0% +modulus this is the phase uh so you can + + + align:start position:0% +modulus this is the phase uh so you can +see that that is why we got a pretty + + align:start position:0% +see that that is why we got a pretty + + + align:start position:0% +see that that is why we got a pretty +horrible image it's because it's got a + + align:start position:0% +horrible image it's because it's got a + + + align:start position:0% +horrible image it's because it's got a +very nasty point spread function uh it's + + align:start position:0% +very nasty point spread function uh it's + + + align:start position:0% +very nasty point spread function uh it's +point spread function for a start that's + + align:start position:0% +point spread function for a start that's + + + align:start position:0% +point spread function for a start that's +got these very large side loes which + + align:start position:0% +got these very large side loes which + + + align:start position:0% +got these very large side loes which +normally we don't like we normally like + + align:start position:0% +normally we don't like we normally like + + + align:start position:0% +normally we don't like we normally like +to have our point spread function to be + + align:start position:0% +to have our point spread function to be + + + align:start position:0% +to have our point spread function to be +nicely narrow and smooth and without big + + align:start position:0% +nicely narrow and smooth and without big + + + align:start position:0% +nicely narrow and smooth and without big +side loses and then more than that it's + + align:start position:0% +side loses and then more than that it's + + + align:start position:0% +side loses and then more than that it's +also got these horrible phase jumps uh + + align:start position:0% +also got these horrible phase jumps uh + + + align:start position:0% +also got these horrible phase jumps uh +which I think are very likely to produce + + align:start position:0% +which I think are very likely to produce + + + align:start position:0% +which I think are very likely to produce +pretty awful image uh which is probably + + align:start position:0% +pretty awful image uh which is probably + + + align:start position:0% +pretty awful image uh which is probably +what we saw uh so this goes through the + + align:start position:0% +what we saw uh so this goes through the + + + align:start position:0% +what we saw uh so this goes through the +the the sum of actually doing that so + + align:start position:0% +the the sum of actually doing that so + + + align:start position:0% +the the sum of actually doing that so +this is the same as we had before then + + align:start position:0% +this is the same as we had before then + + + align:start position:0% +this is the same as we had before then +uh the the big rectangle minus the + + align:start position:0% +uh the the big rectangle minus the + + + align:start position:0% +uh the the big rectangle minus the +little rectangle with a phase uh and um + + align:start position:0% +little rectangle with a phase uh and um + + + align:start position:0% +little rectangle with a phase uh and um +then we got to do the fer transform of + + align:start position:0% +then we got to do the fer transform of + + + align:start position:0% +then we got to do the fer transform of +that uh and um so the way we've done it + + align:start position:0% +that uh and um so the way we've done it + + + align:start position:0% +that uh and um so the way we've done it +here then we just got this the sum of + + align:start position:0% +here then we just got this the sum of + + + align:start position:0% +here then we just got this the sum of +two rectangles each of them becomes a + + align:start position:0% +two rectangles each of them becomes a + + + align:start position:0% +two rectangles each of them becomes a +sync uh but you got a you've got this + + align:start position:0% +sync uh but you got a you've got this + + + align:start position:0% +sync uh but you got a you've got this +eye here you have to be careful of uh + + align:start position:0% +eye here you have to be careful of uh + + + align:start position:0% +eye here you have to be careful of uh +and then finally um we work out the the + + align:start position:0% +and then finally um we work out the the + + + align:start position:0% +and then finally um we work out the the +the modulus square of the of the of the + + align:start position:0% +the modulus square of the of the of the + + + align:start position:0% +the modulus square of the of the of the +point spread function and the phase of + + align:start position:0% +point spread function and the phase of + + + align:start position:0% +point spread function and the phase of +the point spread function right so this + + align:start position:0% +the point spread function right so this + + + align:start position:0% +the point spread function right so this +is the modulus square of the point + + align:start position:0% +is the modulus square of the point + + + align:start position:0% +is the modulus square of the point +spread function so these side loes are + + align:start position:0% +spread function so these side loes are + + + align:start position:0% +spread function so these side loes are +actually quite + + align:start position:0% +actually quite + + + align:start position:0% +actually quite +huge um + + align:start position:0% +huge um + + + align:start position:0% +huge um +quite quite + + align:start position:0% + + + + align:start position:0% + +big okay yeah that's just looking at the + + align:start position:0% +big okay yeah that's just looking at the + + + align:start position:0% +big okay yeah that's just looking at the +difference between the two then uh so uh + + align:start position:0% +difference between the two then uh so uh + + + align:start position:0% +difference between the two then uh so uh +if we have our low pass filter uh so + + align:start position:0% +if we have our low pass filter uh so + + + align:start position:0% +if we have our low pass filter uh so +this is what I'm was saying about these + + align:start position:0% +this is what I'm was saying about these + + + align:start position:0% +this is what I'm was saying about these +being huge you see the the the low pass + + align:start position:0% +being huge you see the the the low pass + + + align:start position:0% +being huge you see the the the low pass +filter uh these side loes are pretty + + align:start position:0% +filter uh these side loes are pretty + + + align:start position:0% +filter uh these side loes are pretty +small by comparison I guess you could + + align:start position:0% +small by comparison I guess you could + + + align:start position:0% +small by comparison I guess you could +you you could use some sort of shaded + + align:start position:0% +you you could use some sort of shaded + + + align:start position:0% +you you could use some sort of shaded +aperture or maybe uh an aperture with + + align:start position:0% +aperture or maybe uh an aperture with + + + align:start position:0% +aperture or maybe uh an aperture with +some structure that would allow you to + + align:start position:0% +some structure that would allow you to + + + align:start position:0% +some structure that would allow you to +make those those um side loes even + + align:start position:0% +make those those um side loes even + + + align:start position:0% +make those those um side loes even +smaller uh this is this process that's + + align:start position:0% +smaller uh this is this process that's + + + align:start position:0% +smaller uh this is this process that's +sometimes called + + align:start position:0% +sometimes called + + + align:start position:0% +sometimes called +apodization um apodization means to uh + + align:start position:0% +apodization um apodization means to uh + + + align:start position:0% +apodization um apodization means to uh +cut off the feet I I think if George was + + align:start position:0% +cut off the feet I I think if George was + + + align:start position:0% +cut off the feet I I think if George was +giving the talk he'd say something about + + align:start position:0% +giving the talk he'd say something about + + + align:start position:0% +giving the talk he'd say something about +the Greek for Feats being something to + + align:start position:0% +the Greek for Feats being something to + + + align:start position:0% +the Greek for Feats being something to +do with + + align:start position:0% +do with + + + align:start position:0% +do with +pod right right there we are + + align:start position:0% + + + + align:start position:0% + +so okay are we we we're over time really + + align:start position:0% +so okay are we we we're over time really + + + align:start position:0% +so okay are we we we're over time really +you want to stop + + align:start position:0% +you want to stop + + + align:start position:0% +you want to stop +now yeah maybe that's a good point I + + align:start position:0% +now yeah maybe that's a good point I + + + align:start position:0% +now yeah maybe that's a good point I +think that's good you've got the a + + align:start position:0% +think that's good you've got the a + + + align:start position:0% +think that's good you've got the a +concept of the point spread function uh + + align:start position:0% +concept of the point spread function uh + + + align:start position:0% +concept of the point spread function uh +now you've got a week to think about the + + align:start position:0% +now you've got a week to think about the + + + align:start position:0% +now you've got a week to think about the +point spread function and and then next + + align:start position:0% +point spread function and and then next + + + align:start position:0% +point spread function and and then next +time it'll all be very + + align:start position:0% +time it'll all be very + + + align:start position:0% +time it'll all be very +clear okay so any questions from either + + align:start position:0% +clear okay so any questions from either + + + align:start position:0% +clear okay so any questions from either +side \ No newline at end of file diff --git a/MMWqGD4Urso.txt b/MMWqGD4Urso.txt new file mode 100644 index 0000000000000000000000000000000000000000..940282e5098c12c69dd9330fdcb934ed5c872ca1 --- /dev/null +++ b/MMWqGD4Urso.txt @@ -0,0 +1,1123 @@ +align:start position:0% + +hi there welcome back to recitation in + + align:start position:0% +hi there welcome back to recitation in + + + align:start position:0% +hi there welcome back to recitation in +lecture you've been learning about when + + align:start position:0% +lecture you've been learning about when + + + align:start position:0% +lecture you've been learning about when +vectors are + + align:start position:0% +vectors are + + + align:start position:0% +vectors are +dependent when they span a space what a + + align:start position:0% +dependent when they span a space what a + + + align:start position:0% +dependent when they span a space what a +basis is what a dimension of a vector + + align:start position:0% +basis is what a dimension of a vector + + + align:start position:0% +basis is what a dimension of a vector +space is and the problem for today is + + align:start position:0% +space is and the problem for today is + + + align:start position:0% +space is and the problem for today is +exactly about that we have a vector + + align:start position:0% +exactly about that we have a vector + + + align:start position:0% +exactly about that we have a vector +space that is given it's spanned by + + align:start position:0% +space that is given it's spanned by + + + align:start position:0% +space that is given it's spanned by +these four vectors and we're asked to + + align:start position:0% +these four vectors and we're asked to + + + align:start position:0% +these four vectors and we're asked to +find the dimension of that vector space + + align:start position:0% +find the dimension of that vector space + + + align:start position:0% +find the dimension of that vector space +and the basis for it well why don't you + + align:start position:0% +and the basis for it well why don't you + + + align:start position:0% +and the basis for it well why don't you +hit pause on the video and work on it + + align:start position:0% +hit pause on the video and work on it + + + align:start position:0% +hit pause on the video and work on it +for a while and I'll come back in a + + align:start position:0% +for a while and I'll come back in a + + + align:start position:0% +for a while and I'll come back in a +little bit to help you out with it all + + align:start position:0% +little bit to help you out with it all + + + align:start position:0% +little bit to help you out with it all +right we're back let's work on it well + + align:start position:0% +right we're back let's work on it well + + + align:start position:0% +right we're back let's work on it well +so we need to find the dimension and the + + align:start position:0% +so we need to find the dimension and the + + + align:start position:0% +so we need to find the dimension and the +basis remember what the dimension is + + align:start position:0% +basis remember what the dimension is + + + align:start position:0% +basis remember what the dimension is +it's simply the number of vectors in a + + align:start position:0% +it's simply the number of vectors in a + + + align:start position:0% +it's simply the number of vectors in a +basis for the vector space so actually + + align:start position:0% +basis for the vector space so actually + + + align:start position:0% +basis for the vector space so actually +the problems is backwards we want to + + align:start position:0% +the problems is backwards we want to + + + align:start position:0% +the problems is backwards we want to +find the basis for the space first and + + align:start position:0% +find the basis for the space first and + + + align:start position:0% +find the basis for the space first and +then find the dimension all right all + + align:start position:0% +then find the dimension all right all + + + align:start position:0% +then find the dimension all right all +right first here and second here all + + align:start position:0% +right first here and second here all + + + align:start position:0% +right first here and second here all +right so we want to find a basis for the + + align:start position:0% +right so we want to find a basis for the + + + align:start position:0% +right so we want to find a basis for the +vector space spanned by these four + + align:start position:0% +vector space spanned by these four + + + align:start position:0% +vector space spanned by these four +vectors all right so you might be + + align:start position:0% +vectors all right so you might be + + + align:start position:0% +vectors all right so you might be +tempted to just say that a basis for + + align:start position:0% +tempted to just say that a basis for + + + align:start position:0% +tempted to just say that a basis for +this vector space is those four vectors + + align:start position:0% +this vector space is those four vectors + + + align:start position:0% +this vector space is those four vectors +because they span the vector space but + + align:start position:0% +because they span the vector space but + + + align:start position:0% +because they span the vector space but +there's another thing that a basis has + + align:start position:0% +there's another thing that a basis has + + + align:start position:0% +there's another thing that a basis has +to satisfy and it is the elements of the + + align:start position:0% +to satisfy and it is the elements of the + + + align:start position:0% +to satisfy and it is the elements of the +basis have to be linearly independent + + align:start position:0% +basis have to be linearly independent + + + align:start position:0% +basis have to be linearly independent +and we don't know that these are so we + + align:start position:0% +and we don't know that these are so we + + + align:start position:0% +and we don't know that these are so we +have to check how do we check that four + + align:start position:0% +have to check how do we check that four + + + align:start position:0% +have to check how do we check that four +vectors are linearly independent well + + align:start position:0% +vectors are linearly independent well + + + align:start position:0% +vectors are linearly independent well +there's a couple of different ways but + + align:start position:0% +there's a couple of different ways but + + + align:start position:0% +there's a couple of different ways but +here's what we're going to do we're + + align:start position:0% +here's what we're going to do we're + + + align:start position:0% +here's what we're going to do we're +going to put these vectors as rows of a + + align:start position:0% +going to put these vectors as rows of a + + + align:start position:0% +going to put these vectors as rows of a +matrix and then we'll do elimination and + + align:start position:0% +matrix and then we'll do elimination and + + + align:start position:0% +matrix and then we'll do elimination and +when we get to the end the rows that + + align:start position:0% +when we get to the end the rows that + + + align:start position:0% +when we get to the end the rows that +have pivots are the independent ones so + + align:start position:0% +have pivots are the independent ones so + + + align:start position:0% +have pivots are the independent ones so +let's do that + + align:start position:0% +let's do that + + + align:start position:0% +let's do that +1 1 plus 2 0 minus 1 1 2 0 minus 4 1 0 1 + + align:start position:0% +1 1 plus 2 0 minus 1 1 2 0 minus 4 1 0 1 + + + align:start position:0% +1 1 plus 2 0 minus 1 1 2 0 minus 4 1 0 1 +3 2 + + align:start position:0% +3 2 + + + align:start position:0% +3 2 +- 3 0 - 2 + + align:start position:0% + + + + align:start position:0% + +all right by now you must have done + + align:start position:0% +all right by now you must have done + + + align:start position:0% +all right by now you must have done +elimination a million times so I'll go a + + align:start position:0% +elimination a million times so I'll go a + + + align:start position:0% +elimination a million times so I'll go a +little bit faster - its 1 0 1 0 + 2 - 4 + + align:start position:0% +little bit faster - its 1 0 1 0 + 2 - 4 + + + align:start position:0% +little bit faster - its 1 0 1 0 + 2 - 4 +- it's already done 1 3 minutes 3 - 2 + + align:start position:0% +- it's already done 1 3 minutes 3 - 2 + + + align:start position:0% +- it's already done 1 3 minutes 3 - 2 +minutes - 3 - 2 0 + 4 - 2 & 2 alright + + align:start position:0% +minutes - 3 - 2 0 + 4 - 2 & 2 alright + + + align:start position:0% +minutes - 3 - 2 0 + 4 - 2 & 2 alright +one more step 1 1 - 2 0 - 1 I'll do done + + align:start position:0% +one more step 1 1 - 2 0 - 1 I'll do done + + + align:start position:0% +one more step 1 1 - 2 0 - 1 I'll do done +0 1 2 1 2 0 1 minus 1 is 0 3 minus 2 is + + align:start position:0% +0 1 2 1 2 0 1 minus 1 is 0 3 minus 2 is + + + align:start position:0% +0 1 2 1 2 0 1 minus 1 is 0 3 minus 2 is +1 - 3 + 4 is 1 2 minus 2 is 0 1 minus 1 + + align:start position:0% +1 - 3 + 4 is 1 2 minus 2 is 0 1 minus 1 + + + align:start position:0% +1 - 3 + 4 is 1 2 minus 2 is 0 1 minus 1 +is 0 - 2 again and 0 oh you can see + + align:start position:0% +is 0 - 2 again and 0 oh you can see + + + align:start position:0% +is 0 - 2 again and 0 oh you can see +where this is going + + align:start position:0% +where this is going + + + align:start position:0% +where this is going +and the next step this row is going to + + align:start position:0% +and the next step this row is going to + + + align:start position:0% +and the next step this row is going to +disappear - 2 0 1 0 1 - 2 0 0 1 1 0 0 0 + + align:start position:0% +disappear - 2 0 1 0 1 - 2 0 0 1 1 0 0 0 + + + align:start position:0% +disappear - 2 0 1 0 1 - 2 0 0 1 1 0 0 0 +0 0 alright we're done with elimination + + align:start position:0% +0 0 alright we're done with elimination + + + align:start position:0% +0 0 alright we're done with elimination +and so let's circle our pivots and here + + align:start position:0% +and so let's circle our pivots and here + + + align:start position:0% +and so let's circle our pivots and here +our pivots we have three pivots and so + + align:start position:0% +our pivots we have three pivots and so + + + align:start position:0% +our pivots we have three pivots and so +these 3 rows are linearly independent no + + align:start position:0% +these 3 rows are linearly independent no + + + align:start position:0% +these 3 rows are linearly independent no +and in fact these rows still span the + + align:start position:0% +and in fact these rows still span the + + + align:start position:0% +and in fact these rows still span the +same space that the initial four rows + + align:start position:0% +same space that the initial four rows + + + align:start position:0% +same space that the initial four rows +did because when you do elimination all + + align:start position:0% +did because when you do elimination all + + + align:start position:0% +did because when you do elimination all +that you're doing is recombining a rose + + align:start position:0% +that you're doing is recombining a rose + + + align:start position:0% +that you're doing is recombining a rose +well by doing linear combinations of + + align:start position:0% +well by doing linear combinations of + + + align:start position:0% +well by doing linear combinations of +them so for example your first first row + + align:start position:0% +them so for example your first first row + + + align:start position:0% +them so for example your first first row +state + + align:start position:0% +state + + + align:start position:0% +state +same throughout your second row was + + align:start position:0% +same throughout your second row was + + + align:start position:0% +same throughout your second row was +replaced by Row 2 minus Row 1 but it's + + align:start position:0% +replaced by Row 2 minus Row 1 but it's + + + align:start position:0% +replaced by Row 2 minus Row 1 but it's +really still spanning the same space and + + align:start position:0% +really still spanning the same space and + + + align:start position:0% +really still spanning the same space and +it goes on and then the fourth row it + + align:start position:0% +it goes on and then the fourth row it + + + align:start position:0% +it goes on and then the fourth row it +turns out was useless you only needed + + align:start position:0% +turns out was useless you only needed + + + align:start position:0% +turns out was useless you only needed +the first three so the elements for a + + align:start position:0% +the first three so the elements for a + + + align:start position:0% +the first three so the elements for a +basis well they will be these three so + + align:start position:0% +basis well they will be these three so + + + align:start position:0% +basis well they will be these three so +let me write that zero one one zero + + align:start position:0% + + + + align:start position:0% + +could you have used the first three rows + + align:start position:0% +could you have used the first three rows + + + align:start position:0% +could you have used the first three rows +yes you could you can't always do that + + align:start position:0% +yes you could you can't always do that + + + align:start position:0% +yes you could you can't always do that +sometimes in elimination you have to + + align:start position:0% +sometimes in elimination you have to + + + align:start position:0% +sometimes in elimination you have to +switch rows because there's a zero where + + align:start position:0% +switch rows because there's a zero where + + + align:start position:0% +switch rows because there's a zero where +a pivot should be when that happens you + + align:start position:0% +a pivot should be when that happens you + + + align:start position:0% +a pivot should be when that happens you +have to use these three or you have to + + align:start position:0% +have to use these three or you have to + + + align:start position:0% +have to use these three or you have to +keep track of which row you switched to + + align:start position:0% +keep track of which row you switched to + + + align:start position:0% +keep track of which row you switched to +go back and use the initial ones but + + align:start position:0% +go back and use the initial ones but + + + align:start position:0% +go back and use the initial ones but +it's really safe to use these ones and + + align:start position:0% +it's really safe to use these ones and + + + align:start position:0% +it's really safe to use these ones and +also they're simpler than the ones that + + align:start position:0% +also they're simpler than the ones that + + + align:start position:0% +also they're simpler than the ones that +you started with so why not the other + + align:start position:0% +you started with so why not the other + + + align:start position:0% +you started with so why not the other +question that we had was what is the + + align:start position:0% +question that we had was what is the + + + align:start position:0% +question that we had was what is the +dimension of the vector space well this + + align:start position:0% +dimension of the vector space well this + + + align:start position:0% +dimension of the vector space well this +is the easy part + + align:start position:0% +is the easy part + + + align:start position:0% +is the easy part +the dimension of the vector space is 1 2 + + align:start position:0% +the dimension of the vector space is 1 2 + + + align:start position:0% +the dimension of the vector space is 1 2 +3 and that solves the problem but + + align:start position:0% +3 and that solves the problem but + + + align:start position:0% +3 and that solves the problem but +there's one more thing that I want to + + align:start position:0% +there's one more thing that I want to + + + align:start position:0% +there's one more thing that I want to +tell you I told you that there's a + + align:start position:0% +tell you I told you that there's a + + + align:start position:0% +tell you I told you that there's a +couple of ways to find out which of + + align:start position:0% +couple of ways to find out which of + + + align:start position:0% +couple of ways to find out which of +those four vectors are linearly + + align:start position:0% +those four vectors are linearly + + + align:start position:0% +those four vectors are linearly +independent and the one that I used was + + align:start position:0% +independent and the one that I used was + + + align:start position:0% +independent and the one that I used was +I put them in two rows and perform the + + align:start position:0% +I put them in two rows and perform the + + + align:start position:0% +I put them in two rows and perform the +elimination and picked out the rows that + + align:start position:0% +elimination and picked out the rows that + + + align:start position:0% +elimination and picked out the rows that +have pivots on them another way to do it + + align:start position:0% +have pivots on them another way to do it + + + align:start position:0% +have pivots on them another way to do it +is to write the initial vectors as + + align:start position:0% +is to write the initial vectors as + + + align:start position:0% +is to write the initial vectors as +columns of the matrix and then perform + + align:start position:0% +columns of the matrix and then perform + + + align:start position:0% +columns of the matrix and then perform +elimination that also works and as you + + align:start position:0% +elimination that also works and as you + + + align:start position:0% +elimination that also works and as you +know because you're only working with + + align:start position:0% +know because you're only working with + + + align:start position:0% +know because you're only working with +the transpose of this matrix you'll get + + align:start position:0% +the transpose of this matrix you'll get + + + align:start position:0% +the transpose of this matrix you'll get +the same number of pivots let's go over + + align:start position:0% +the same number of pivots let's go over + + + align:start position:0% +the same number of pivots let's go over +here where I have the same while the + + align:start position:0% +here where I have the same while the + + + align:start position:0% +here where I have the same while the +transpose of that matrix I have the same + + align:start position:0% +transpose of that matrix I have the same + + + align:start position:0% +transpose of that matrix I have the same +vectors but now written as columns my + + align:start position:0% +vectors but now written as columns my + + + align:start position:0% +vectors but now written as columns my +four initial vector is written as + + align:start position:0% +four initial vector is written as + + + align:start position:0% +four initial vector is written as +columns and here I have performed + + align:start position:0% +columns and here I have performed + + + align:start position:0% +columns and here I have performed +elimination + + align:start position:0% +elimination + + + align:start position:0% +elimination +and this is the final result let me + + align:start position:0% +and this is the final result let me + + + align:start position:0% +and this is the final result let me +circle the pivots again here they are + + align:start position:0% +circle the pivots again here they are + + + align:start position:0% +circle the pivots again here they are +three which is going to give me three + + align:start position:0% +three which is going to give me three + + + align:start position:0% +three which is going to give me three +independent three linearly independent + + align:start position:0% +independent three linearly independent + + + align:start position:0% +independent three linearly independent +vectors and hence three elements of the + + align:start position:0% +vectors and hence three elements of the + + + align:start position:0% +vectors and hence three elements of the +basis and hence dimension three for the + + align:start position:0% +basis and hence dimension three for the + + + align:start position:0% +basis and hence dimension three for the +vector space but I can no longer use + + align:start position:0% +vector space but I can no longer use + + + align:start position:0% +vector space but I can no longer use +these three these three columns as + + align:start position:0% +these three these three columns as + + + align:start position:0% +these three these three columns as +elements of the basis because when I did + + align:start position:0% +elements of the basis because when I did + + + align:start position:0% +elements of the basis because when I did +elimination I changed the column space + + align:start position:0% +elimination I changed the column space + + + align:start position:0% +elimination I changed the column space +so in the column space of this vectors + + align:start position:0% +so in the column space of this vectors + + + align:start position:0% +so in the column space of this vectors +of this matrix is not the same as the + + align:start position:0% +of this matrix is not the same as the + + + align:start position:0% +of this matrix is not the same as the +column space of the eliminated version + + align:start position:0% +column space of the eliminated version + + + align:start position:0% +column space of the eliminated version +so I cannot use these in fact if you + + align:start position:0% +so I cannot use these in fact if you + + + align:start position:0% +so I cannot use these in fact if you +look at them you can probably understand + + align:start position:0% +look at them you can probably understand + + + align:start position:0% +look at them you can probably understand +that they're not going to span the same + + align:start position:0% +that they're not going to span the same + + + align:start position:0% +that they're not going to span the same +space as these because all that I have + + align:start position:0% +space as these because all that I have + + + align:start position:0% +space as these because all that I have +done here are zeros and I get a lot more + + align:start position:0% +done here are zeros and I get a lot more + + + align:start position:0% +done here are zeros and I get a lot more +than just zeros in the last two entries + + align:start position:0% +than just zeros in the last two entries + + + align:start position:0% +than just zeros in the last two entries +of the vectors so what I need to do is + + align:start position:0% +of the vectors so what I need to do is + + + align:start position:0% +of the vectors so what I need to do is +the pivots are in the first second and + + align:start position:0% +the pivots are in the first second and + + + align:start position:0% +the pivots are in the first second and +third columns I need to use these three + + align:start position:0% +third columns I need to use these three + + + align:start position:0% +third columns I need to use these three +columns as my basis I'll just write + + align:start position:0% +columns as my basis I'll just write + + + align:start position:0% +columns as my basis I'll just write +basis down here and that will work too + + align:start position:0% +basis down here and that will work too + + + align:start position:0% +basis down here and that will work too +so see I have produced two different + + align:start position:0% +so see I have produced two different + + + align:start position:0% +so see I have produced two different +basis for the same vector space which is + + align:start position:0% +basis for the same vector space which is + + + align:start position:0% +basis for the same vector space which is +totally fine + + align:start position:0% +totally fine + + + align:start position:0% +totally fine +you can pick the basis that you prefer + + align:start position:0% +you can pick the basis that you prefer + + + align:start position:0% +you can pick the basis that you prefer +alright we're done thank you \ No newline at end of file diff --git a/MXTA8HlhnuM.txt b/MXTA8HlhnuM.txt new file mode 100644 index 0000000000000000000000000000000000000000..29abbab17ad097c5a8365df5ea8286d09a635389 --- /dev/null +++ b/MXTA8HlhnuM.txt @@ -0,0 +1,16027 @@ +align:start position:0% + +go ahead and uh turn turn to your + + align:start position:0% +go ahead and uh turn turn to your + + + align:start position:0% +go ahead and uh turn turn to your +neighbor and start. Uh one thing you + + align:start position:0% +neighbor and start. Uh one thing you + + + align:start position:0% +neighbor and start. Uh one thing you +could do is pull out the main reading + + align:start position:0% +could do is pull out the main reading + + + align:start position:0% +could do is pull out the main reading +that we did about situated learning + + align:start position:0% +that we did about situated learning + + + align:start position:0% +that we did about situated learning +because we'll do kind of a close read of + + align:start position:0% +because we'll do kind of a close read of + + + align:start position:0% +because we'll do kind of a close read of +that today. So, um, pull that up on + + align:start position:0% +that today. So, um, pull that up on + + + align:start position:0% +that today. So, um, pull that up on +something and then, um, in the minutes + + align:start position:0% +something and then, um, in the minutes + + + align:start position:0% +something and then, um, in the minutes +that we have, we usually start 105, but + + align:start position:0% +that we have, we usually start 105, but + + + align:start position:0% +that we have, we usually start 105, but +in the minutes that we have, uh, turn to + + align:start position:0% +in the minutes that we have, uh, turn to + + + align:start position:0% +in the minutes that we have, uh, turn to +your, uh, turn to your neighbor and + + align:start position:0% +your, uh, turn to your neighbor and + + + align:start position:0% +your, uh, turn to your neighbor and +start thinking about why why babies + + align:start position:0% +start thinking about why why babies + + + align:start position:0% +start thinking about why why babies +would give, uh, cognitive load theorist + + align:start position:0% +would give, uh, cognitive load theorist + + + align:start position:0% +would give, uh, cognitive load theorist +conions. + + align:start position:0% + + + + align:start position:0% + +All right. as a just just as one level + + align:start position:0% +All right. as a just just as one level + + + align:start position:0% +All right. as a just just as one level +setting thing in case you haven't hung + + align:start position:0% +setting thing in case you haven't hung + + + align:start position:0% +setting thing in case you haven't hung +out with babies in a while. Like in + + align:start position:0% +out with babies in a while. Like in + + + align:start position:0% +out with babies in a while. Like in +their first few years of life, how would + + align:start position:0% +their first few years of life, how would + + + align:start position:0% +their first few years of life, how would +you characterize the amount and rate of + + align:start position:0% +you characterize the amount and rate of + + + align:start position:0% +you characterize the amount and rate of +learning that babies do? Insane. Insane. + + align:start position:0% +learning that babies do? Insane. Insane. + + + align:start position:0% +learning that babies do? Insane. Insane. +It is bonkers how much babies learn. I + + align:start position:0% +It is bonkers how much babies learn. I + + + align:start position:0% +It is bonkers how much babies learn. I +mean, a very strong feeling I had when I + + align:start position:0% +mean, a very strong feeling I had when I + + + align:start position:0% +mean, a very strong feeling I had when I +was first father was like like I I do + + align:start position:0% +was first father was like like I I do + + + align:start position:0% +was first father was like like I I do +not improve at all in a week or in a + + align:start position:0% +not improve at all in a week or in a + + + align:start position:0% +not improve at all in a week or in a +month or really most years. I'm really + + align:start position:0% +month or really most years. I'm really + + + align:start position:0% +month or really most years. I'm really +like not that much better than I was the + + align:start position:0% +like not that much better than I was the + + + align:start position:0% +like not that much better than I was the +beginning of the year. And you're just + + align:start position:0% +beginning of the year. And you're just + + + align:start position:0% +beginning of the year. And you're just +watching these infants who are totally + + align:start position:0% +watching these infants who are totally + + + align:start position:0% +watching these infants who are totally +transformed because they are learning + + align:start position:0% +transformed because they are learning + + + align:start position:0% +transformed because they are learning +things at an amazing rate that you can + + align:start position:0% +things at an amazing rate that you can + + + align:start position:0% +things at an amazing rate that you can +see daily, weekly, monthly, you know, + + align:start position:0% +see daily, weekly, monthly, you know, + + + align:start position:0% +see daily, weekly, monthly, you know, +incredibly accelerated learning. Um so + + align:start position:0% +incredibly accelerated learning. Um so + + + align:start position:0% +incredibly accelerated learning. Um so +let's use we'll just use that to level + + align:start position:0% +let's use we'll just use that to level + + + align:start position:0% +let's use we'll just use that to level +set. Um let's let's let's take it as a + + align:start position:0% +set. Um let's let's let's take it as a + + + align:start position:0% +set. Um let's let's let's take it as a +given that babies learn an amazing + + align:start position:0% +given that babies learn an amazing + + + align:start position:0% +given that babies learn an amazing +amount in their early years. Um why now + + align:start position:0% +amount in their early years. Um why now + + + align:start position:0% +amount in their early years. Um why now +keep talking why would that prove to be + + align:start position:0% +keep talking why would that prove to be + + + align:start position:0% +keep talking why would that prove to be +such why would that give cognitive load + + align:start position:0% +such why would that give cognitive load + + + align:start position:0% +such why would that give cognitive load +theorist such a + + align:start position:0% +theorist such a + + + align:start position:0% +theorist such a +conipion and and you can think about um + + align:start position:0% +conipion and and you can think about um + + + align:start position:0% +conipion and and you can think about um +how it connects to some of the stuff + + align:start position:0% +how it connects to some of the stuff + + + align:start position:0% +how it connects to some of the stuff +that you've been reading about situated + + align:start position:0% +that you've been reading about situated + + + align:start position:0% +that you've been reading about situated +load theory keep talking + + align:start position:0% + + + + align:start position:0% + +all right good what are some what are + + align:start position:0% +all right good what are some what are + + + align:start position:0% +all right good what are some what are +some observations that people made + + align:start position:0% + + + + align:start position:0% + +what are what are baby babies are babies + + align:start position:0% +what are what are baby babies are babies + + + align:start position:0% +what are what are baby babies are babies +are significant so what are what are + + align:start position:0% +are significant so what are what are + + + align:start position:0% +are significant so what are what are +what are some of the observations that + + align:start position:0% +what are some of the observations that + + + align:start position:0% +what are some of the observations that +that you + + align:start position:0% +that you + + + align:start position:0% +that you +made. What were you guys talking about + + align:start position:0% +made. What were you guys talking about + + + align:start position:0% +made. What were you guys talking about +in the + + align:start position:0% +in the + + + align:start position:0% +in the +back? What was your group talking about, + + align:start position:0% +back? What was your group talking about, + + + align:start position:0% +back? What was your group talking about, +Gloria? Um, I was saying that if like + + align:start position:0% +Gloria? Um, I was saying that if like + + + align:start position:0% +Gloria? Um, I was saying that if like +cognitive load theory was true, then + + align:start position:0% +cognitive load theory was true, then + + + align:start position:0% +cognitive load theory was true, then +that would say that babies probably + + align:start position:0% +that would say that babies probably + + + align:start position:0% +that would say that babies probably +can't learn like anything because + + align:start position:0% +can't learn like anything because + + + align:start position:0% +can't learn like anything because +everything is extraneous knowledge to + + align:start position:0% +everything is extraneous knowledge to + + + align:start position:0% +everything is extraneous knowledge to +them and they don't have any long-term + + align:start position:0% +them and they don't have any long-term + + + align:start position:0% +them and they don't have any long-term +memory. They haven't formed any skills + + align:start position:0% +memory. They haven't formed any skills + + + align:start position:0% +memory. They haven't formed any skills +yet. All right. Yep. So, they're so + + align:start position:0% +yet. All right. Yep. So, they're so + + + align:start position:0% +yet. All right. Yep. So, they're so +they're not drawing in they don't have a + + align:start position:0% +they're not drawing in they don't have a + + + align:start position:0% +they're not drawing in they don't have a +lot of long-term memory to draw on. + + align:start position:0% +lot of long-term memory to draw on. + + + align:start position:0% +lot of long-term memory to draw on. +They, you know, they are like the + + align:start position:0% +They, you know, they are like the + + + align:start position:0% +They, you know, they are like the +canonical us looking at Sanskrit letters + + align:start position:0% +canonical us looking at Sanskrit letters + + + align:start position:0% +canonical us looking at Sanskrit letters +where like everything is its own sort of + + align:start position:0% +where like everything is its own sort of + + + align:start position:0% +where like everything is its own sort of +discrete part like um so you would think + + align:start position:0% +discrete part like um so you would think + + + align:start position:0% +discrete part like um so you would think +they're working memory. I mean, you + + align:start position:0% +they're working memory. I mean, you + + + align:start position:0% +they're working memory. I mean, you +know, this video I think is sort of + + align:start position:0% +know, this video I think is sort of + + + align:start position:0% +know, this video I think is sort of +helpful for that. Like everything on + + align:start position:0% +helpful for that. Like everything on + + + align:start position:0% +helpful for that. Like everything on +this screen is brand new to them. + + align:start position:0% +this screen is brand new to them. + + + align:start position:0% +this screen is brand new to them. +There's nothing that they've ever seen + + align:start position:0% +There's nothing that they've ever seen + + + align:start position:0% +There's nothing that they've ever seen +before and it's filled like there's a + + align:start position:0% +before and it's filled like there's a + + + align:start position:0% +before and it's filled like there's a +slide and a dad and that other thing + + align:start position:0% +slide and a dad and that other thing + + + align:start position:0% +slide and a dad and that other thing +back there and all this stuff on the + + align:start position:0% +back there and all this stuff on the + + + align:start position:0% +back there and all this stuff on the +ground and people are talking and the + + align:start position:0% +ground and people are talking and the + + + align:start position:0% +ground and people are talking and the +sun is out and all these things are + + align:start position:0% +sun is out and all these things are + + + align:start position:0% +sun is out and all these things are +happening at once. Good. What else did + + align:start position:0% +happening at once. Good. What else did + + + align:start position:0% +happening at once. Good. What else did +people talk about? + + align:start position:0% +people talk about? + + + align:start position:0% +people talk about? +Um it's also like the the speed with + + align:start position:0% +Um it's also like the the speed with + + + align:start position:0% +Um it's also like the the speed with +which they learn doesn't really connect + + align:start position:0% +which they learn doesn't really connect + + + align:start position:0% +which they learn doesn't really connect +with like the bottleneck theory and like + + align:start position:0% +with like the bottleneck theory and like + + + align:start position:0% +with like the bottleneck theory and like +um the theory of like it takes a while + + align:start position:0% +um the theory of like it takes a while + + + align:start position:0% +um the theory of like it takes a while +for you to like compile all of this + + align:start position:0% +for you to like compile all of this + + + align:start position:0% +for you to like compile all of this +information but it almost seems like a + + align:start position:0% +information but it almost seems like a + + + align:start position:0% +information but it almost seems like a +baby sees it one time and is like able + + align:start position:0% +baby sees it one time and is like able + + + align:start position:0% +baby sees it one time and is like able +to retain it. Yeah. babies seem to do + + align:start position:0% +to retain it. Yeah. babies seem to do + + + align:start position:0% +to retain it. Yeah. babies seem to do +exactly the thing that Sweller said um + + align:start position:0% +exactly the thing that Sweller said um + + + align:start position:0% +exactly the thing that Sweller said um +people should not be able to do, which + + align:start position:0% +people should not be able to do, which + + + align:start position:0% +people should not be able to do, which +is to be um I mean, would you gen like + + align:start position:0% +is to be um I mean, would you gen like + + + align:start position:0% +is to be um I mean, would you gen like +this baby learning stuff, would you + + align:start position:0% +this baby learning stuff, would you + + + align:start position:0% +this baby learning stuff, would you +generally characterize their experience + + align:start position:0% +generally characterize their experience + + + align:start position:0% +generally characterize their experience +as sort of open-ended problem solving or + + align:start position:0% +as sort of open-ended problem solving or + + + align:start position:0% +as sort of open-ended problem solving or +like being carefully walked through a + + align:start position:0% +like being carefully walked through a + + + align:start position:0% +like being carefully walked through a +series of worked + + align:start position:0% + + + + align:start position:0% + +examples? How would you describe it? + + align:start position:0% +examples? How would you describe it? + + + align:start position:0% +examples? How would you describe it? +Open. Yeah, this I mean like I'm just + + align:start position:0% +Open. Yeah, this I mean like I'm just + + + align:start position:0% +Open. Yeah, this I mean like I'm just +like going on the slide and going down, + + align:start position:0% +like going on the slide and going down, + + + align:start position:0% +like going on the slide and going down, +you know? It's not like dad's like, you + + align:start position:0% +you know? It's not like dad's like, you + + + align:start position:0% +you know? It's not like dad's like, you +know, I mean, I think I think you'd find + + align:start position:0% +know, I mean, I think I think you'd find + + + align:start position:0% +know, I mean, I think I think you'd find +more structure and stuff like that, but + + align:start position:0% +more structure and stuff like that, but + + + align:start position:0% +more structure and stuff like that, but +there's a lot of just like, wow, I'm a + + align:start position:0% +there's a lot of just like, wow, I'm a + + + align:start position:0% +there's a lot of just like, wow, I'm a +baby. I'm out there. I'm doing my thing. + + align:start position:0% +baby. I'm out there. I'm doing my thing. + + + align:start position:0% +baby. I'm out there. I'm doing my thing. +Um, you know, and and the worked example + + align:start position:0% +Um, you know, and and the worked example + + + align:start position:0% +Um, you know, and and the worked example +effect and the expert reversal effect + + align:start position:0% +effect and the expert reversal effect + + + align:start position:0% +effect and the expert reversal effect +suggests that that should not be very + + align:start position:0% +suggests that that should not be very + + + align:start position:0% +suggests that that should not be very +effective. You know, the most effective + + align:start position:0% +effective. You know, the most effective + + + align:start position:0% +effective. You know, the most effective +way to teach babies should be, you know, + + align:start position:0% +way to teach babies should be, you know, + + + align:start position:0% +way to teach babies should be, you know, +through like careful, you know, + + align:start position:0% +through like careful, you know, + + + align:start position:0% +through like careful, you know, +devolving scaffolding of language and + + align:start position:0% +devolving scaffolding of language and + + + align:start position:0% +devolving scaffolding of language and +things like that. And that's not what we + + align:start position:0% +things like that. And that's not what we + + + align:start position:0% +things like that. And that's not what we +do. We just like throw babies in with + + align:start position:0% +do. We just like throw babies in with + + + align:start position:0% +do. We just like throw babies in with +people all the time. Um and they uh and + + align:start position:0% +people all the time. Um and they uh and + + + align:start position:0% +people all the time. Um and they uh and +they learn language, they learn + + align:start position:0% +they learn language, they learn + + + align:start position:0% +they learn language, they learn +movement, they learn a few other things + + align:start position:0% +movement, they learn a few other things + + + align:start position:0% +movement, they learn a few other things +at sort of an extraordinary rate. Um so + + align:start position:0% +at sort of an extraordinary rate. Um so + + + align:start position:0% +at sort of an extraordinary rate. Um so +for how do how does how does what + + align:start position:0% +for how do how does how does what + + + align:start position:0% +for how do how does how does what +connections do you see between this set + + align:start position:0% +connections do you see between this set + + + align:start position:0% +connections do you see between this set +of ideas and situated + + align:start position:0% + + + + align:start position:0% + +learning? There's a lot of like trial + + align:start position:0% +learning? There's a lot of like trial + + + align:start position:0% +learning? There's a lot of like trial +and error in it. Like we were talking + + align:start position:0% +and error in it. Like we were talking + + + align:start position:0% +and error in it. Like we were talking +about like hey when they they see a + + align:start position:0% +about like hey when they they see a + + + align:start position:0% +about like hey when they they see a +block they want to go get they start to + + align:start position:0% +block they want to go get they start to + + + align:start position:0% +block they want to go get they start to +figure out the different ways that they + + align:start position:0% +figure out the different ways that they + + + align:start position:0% +figure out the different ways that they +can go get that block. Like but through + + align:start position:0% +can go get that block. Like but through + + + align:start position:0% +can go get that block. Like but through +trial and error trying to stand up, + + align:start position:0% +trial and error trying to stand up, + + + align:start position:0% +trial and error trying to stand up, +trying to crawl, trying to drag + + align:start position:0% +trying to crawl, trying to drag + + + align:start position:0% +trying to crawl, trying to drag +themselves. Yeah. all that kind of + + align:start position:0% +themselves. Yeah. all that kind of + + + align:start position:0% +themselves. Yeah. all that kind of +stuff. Kadus, come on in. Sit with me. + + align:start position:0% +stuff. Kadus, come on in. Sit with me. + + + align:start position:0% +stuff. Kadus, come on in. Sit with me. +No, no, delighted to have you. Um, yeah. + + align:start position:0% +No, no, delighted to have you. Um, yeah. + + + align:start position:0% +No, no, delighted to have you. Um, yeah. +Um, yeah. I mean, this this certainly + + align:start position:0% +Um, yeah. I mean, this this certainly + + + align:start position:0% +Um, yeah. I mean, this this certainly +looks a lot more like situated learning + + align:start position:0% +looks a lot more like situated learning + + + align:start position:0% +looks a lot more like situated learning +than it does look like a sort of + + align:start position:0% +than it does look like a sort of + + + align:start position:0% +than it does look like a sort of +carefully sculpted classroom. Um, and + + align:start position:0% +carefully sculpted classroom. Um, and + + + align:start position:0% +carefully sculpted classroom. Um, and +uh, so for situated learning people, and + + align:start position:0% +uh, so for situated learning people, and + + + align:start position:0% +uh, so for situated learning people, and +you know, we'll we'll I think we'll see + + align:start position:0% +you know, we'll we'll I think we'll see + + + align:start position:0% +you know, we'll we'll I think we'll see +this more in some stuff that we read. + + align:start position:0% +this more in some stuff that we read. + + + align:start position:0% +this more in some stuff that we read. +Um, the experience of babies seems like + + align:start position:0% +Um, the experience of babies seems like + + + align:start position:0% +Um, the experience of babies seems like +something that's pretty important to + + align:start position:0% +something that's pretty important to + + + align:start position:0% +something that's pretty important to +draw from. Um, how would you how would + + align:start position:0% +draw from. Um, how would you how would + + + align:start position:0% +draw from. Um, how would you how would +you how would you + + align:start position:0% +you how would you + + + align:start position:0% +you how would you +characterize like the feelings that + + align:start position:0% +characterize like the feelings that + + + align:start position:0% +characterize like the feelings that +babies have as they learn language? Like + + align:start position:0% +babies have as they learn language? Like + + + align:start position:0% +babies have as they learn language? Like +are they happy? Are they sad? Are they + + align:start position:0% +are they happy? Are they sad? Are they + + + align:start position:0% +are they happy? Are they sad? Are they +angry? Are they frustrated? Are they + + align:start position:0% +angry? Are they frustrated? Are they + + + align:start position:0% +angry? Are they frustrated? Are they +joyful? Are they playful? Like what kind + + align:start position:0% +joyful? Are they playful? Like what kind + + + align:start position:0% +joyful? Are they playful? Like what kind +of feelings do babies seem to have as + + align:start position:0% +of feelings do babies seem to have as + + + align:start position:0% +of feelings do babies seem to have as +they're learning words? + + align:start position:0% +they're learning words? + + + align:start position:0% +they're learning words? +What were you going to say, Jared? I was + + align:start position:0% +What were you going to say, Jared? I was + + + align:start position:0% +What were you going to say, Jared? I was +going to say like they seem kind of + + align:start position:0% +going to say like they seem kind of + + + align:start position:0% +going to say like they seem kind of +fearless and like there there's no like + + align:start position:0% +fearless and like there there's no like + + + align:start position:0% +fearless and like there there's no like +social pressure to like try and + + align:start position:0% +social pressure to like try and + + + align:start position:0% +social pressure to like try and +pronounce this word correctly. They'll + + align:start position:0% +pronounce this word correctly. They'll + + + align:start position:0% +pronounce this word correctly. They'll +just say the word be like, "Oh, good + + align:start position:0% +just say the word be like, "Oh, good + + + align:start position:0% +just say the word be like, "Oh, good +job. make noises come out of our mouths + + align:start position:0% +job. make noises come out of our mouths + + + align:start position:0% +job. make noises come out of our mouths +whenever. Yeah. Do you want to grab + + align:start position:0% +whenever. Yeah. Do you want to grab + + + align:start position:0% +whenever. Yeah. Do you want to grab +another chair? There's no It doesn't + + align:start position:0% +another chair? There's no It doesn't + + + align:start position:0% +another chair? There's no It doesn't +seem like there's there's a lot of fear + + align:start position:0% +seem like there's there's a lot of fear + + + align:start position:0% +seem like there's there's a lot of fear +behind trying to practice what they're + + align:start position:0% +behind trying to practice what they're + + + align:start position:0% +behind trying to practice what they're +learning. Uhhuh. Um but I think like in + + align:start position:0% +learning. Uhhuh. Um but I think like in + + + align:start position:0% +learning. Uhhuh. Um but I think like in +addition to that, there can be like a + + align:start position:0% +addition to that, there can be like a + + + align:start position:0% +addition to that, there can be like a +lot of frustration as well. The + + align:start position:0% +lot of frustration as well. The + + + align:start position:0% +lot of frustration as well. The +consequences of like not knowing how to + + align:start position:0% +consequences of like not knowing how to + + + align:start position:0% +consequences of like not knowing how to +say a specific thing. Yeah. Or or you + + align:start position:0% +say a specific thing. Yeah. Or or you + + + align:start position:0% +say a specific thing. Yeah. Or or you +watch babies when they're you know I + + align:start position:0% +watch babies when they're you know I + + + align:start position:0% +watch babies when they're you know I +mean they cry when they can't articulate + + align:start position:0% +mean they cry when they can't articulate + + + align:start position:0% +mean they cry when they can't articulate +the thing that they want to be able to + + align:start position:0% +the thing that they want to be able to + + + align:start position:0% +the thing that they want to be able to +say or Yeah. And in addition to + + align:start position:0% +say or Yeah. And in addition to + + + align:start position:0% +say or Yeah. And in addition to +frustration, I think there's a bit of + + align:start position:0% +frustration, I think there's a bit of + + + align:start position:0% +frustration, I think there's a bit of +like happiness when they actually + + align:start position:0% +like happiness when they actually + + + align:start position:0% +like happiness when they actually +achieve what they're trying to create + + align:start position:0% +achieve what they're trying to create + + + align:start position:0% +achieve what they're trying to create +and then they feel understood. I think + + align:start position:0% +and then they feel understood. I think + + + align:start position:0% +and then they feel understood. I think +there's some some sort of some sort of + + align:start position:0% +there's some some sort of some sort of + + + align:start position:0% +there's some some sort of some sort of +pride in that. What were you going to + + align:start position:0% +pride in that. What were you going to + + + align:start position:0% +pride in that. What were you going to +say, Courtney? Um, same kind. I wonder + + align:start position:0% +say, Courtney? Um, same kind. I wonder + + + align:start position:0% +say, Courtney? Um, same kind. I wonder +my my daughter, we used to uh we used to + + align:start position:0% +my my daughter, we used to uh we used to + + + align:start position:0% +my my daughter, we used to uh we used to +just my I guess it was my younger one, + + align:start position:0% +just my I guess it was my younger one, + + + align:start position:0% +just my I guess it was my younger one, +we used to just list vegetables and list + + align:start position:0% +we used to just list vegetables and list + + + align:start position:0% +we used to just list vegetables and list +things you get at the supermarket and + + align:start position:0% +things you get at the supermarket and + + + align:start position:0% +things you get at the supermarket and +she thought that was the funniest thing + + align:start position:0% +she thought that was the funniest thing + + + align:start position:0% +she thought that was the funniest thing +ever. you you would just be like + + align:start position:0% +ever. you you would just be like + + + align:start position:0% +ever. you you would just be like +pears in the back of the car just like + + align:start position:0% +pears in the back of the car just like + + + align:start position:0% +pears in the back of the car just like +saying stuff and she's giggling the + + align:start position:0% +saying stuff and she's giggling the + + + align:start position:0% +saying stuff and she's giggling the +whole time. Um you know I I mean if you + + align:start position:0% +whole time. Um you know I I mean if you + + + align:start position:0% +whole time. Um you know I I mean if you +watch a video like this like this is + + align:start position:0% +watch a video like this like this is + + + align:start position:0% +watch a video like this like this is +clearly a delightful um you know there's + + align:start position:0% +clearly a delightful um you know there's + + + align:start position:0% +clearly a delightful um you know there's +there's not a lot that Sweller and + + align:start position:0% +there's not a lot that Sweller and + + + align:start position:0% +there's not a lot that Sweller and +colleagues have to say about like being + + align:start position:0% +colleagues have to say about like being + + + align:start position:0% +colleagues have to say about like being +delighted. Um you know I I I think if + + align:start position:0% +delighted. Um you know I I I think if + + + align:start position:0% +delighted. Um you know I I I think if +you were to if you were to situate like + + align:start position:0% +you were to if you were to situate like + + + align:start position:0% +you were to if you were to situate like +the kind of like moral ethic of work + + align:start position:0% +the kind of like moral ethic of work + + + align:start position:0% +the kind of like moral ethic of work +around learning in cognitive load + + align:start position:0% +around learning in cognitive load + + + align:start position:0% +around learning in cognitive load +theory, it's very like learning is hard. + + align:start position:0% +theory, it's very like learning is hard. + + + align:start position:0% +theory, it's very like learning is hard. +we persevere through a hard thing. Um, + + align:start position:0% +we persevere through a hard thing. Um, + + + align:start position:0% +we persevere through a hard thing. Um, +and we control the hardness of it so + + align:start position:0% +and we control the hardness of it so + + + align:start position:0% +and we control the hardness of it so +that we can scaffold it for people. Um, + + align:start position:0% +that we can scaffold it for people. Um, + + + align:start position:0% +that we can scaffold it for people. Um, +and for situated learning people, these + + align:start position:0% +and for situated learning people, these + + + align:start position:0% +and for situated learning people, these +these aren't really I wouldn't even + + align:start position:0% +these aren't really I wouldn't even + + + align:start position:0% +these aren't really I wouldn't even +these aren't like arguments. And + + align:start position:0% +these aren't like arguments. And + + + align:start position:0% +these aren't like arguments. And +sometimes they're explicit arguments. + + align:start position:0% +sometimes they're explicit arguments. + + + align:start position:0% +sometimes they're explicit arguments. +Sometimes they're just tones that you + + align:start position:0% +Sometimes they're just tones that you + + + align:start position:0% +Sometimes they're just tones that you +find in the way people talk about these + + align:start position:0% +find in the way people talk about these + + + align:start position:0% +find in the way people talk about these +things. They'd be like, "Oh, you know, + + align:start position:0% +things. They'd be like, "Oh, you know, + + + align:start position:0% +things. They'd be like, "Oh, you know, +learning is great. Learning is the thing + + align:start position:0% +learning is great. Learning is the thing + + + align:start position:0% +learning is great. Learning is the thing +that we do and get better at stuff. It's + + align:start position:0% +that we do and get better at stuff. It's + + + align:start position:0% +that we do and get better at stuff. It's +like nice and natural and things like + + align:start position:0% +like nice and natural and things like + + + align:start position:0% +like nice and natural and things like +that." Um, can anybody think of a thing + + align:start position:0% +that." Um, can anybody think of a thing + + + align:start position:0% +that." Um, can anybody think of a thing +that you've learned in which you like + + align:start position:0% +that you've learned in which you like + + + align:start position:0% +that you've learned in which you like +got better at the thing and it was just + + align:start position:0% +got better at the thing and it was just + + + align:start position:0% +got better at the thing and it was just +like playful, enjoyable, natural to get + + align:start position:0% +like playful, enjoyable, natural to get + + + align:start position:0% +like playful, enjoyable, natural to get +better at it? Anybody can shout out one + + align:start position:0% +better at it? Anybody can shout out one + + + align:start position:0% +better at it? Anybody can shout out one +or two things that was like that for + + align:start position:0% +or two things that was like that for + + + align:start position:0% +or two things that was like that for +you? + + align:start position:0% +you? + + + align:start position:0% +you? +When I first learned how to use like a + + align:start position:0% +When I first learned how to use like a + + + align:start position:0% +When I first learned how to use like a +power drill. Awesome. Great. Learning + + align:start position:0% +power drill. Awesome. Great. Learning + + + align:start position:0% +power drill. Awesome. Great. Learning +how to use power drill like very + + align:start position:0% +how to use power drill like very + + + align:start position:0% +how to use power drill like very +satisfying immediate feedback things + + align:start position:0% +satisfying immediate feedback things + + + align:start position:0% +satisfying immediate feedback things +like that. Yeah. Other things that + + align:start position:0% +like that. Yeah. Other things that + + + align:start position:0% +like that. Yeah. Other things that +people really enjoyed learning? Um, I + + align:start position:0% +people really enjoyed learning? Um, I + + + align:start position:0% +people really enjoyed learning? Um, I +think similarly like like tactical + + align:start position:0% +think similarly like like tactical + + + align:start position:0% +think similarly like like tactical +things like learning how to do pottery. + + align:start position:0% +things like learning how to do pottery. + + + align:start position:0% +things like learning how to do pottery. +Oh, great. Yep. Pottery seems like a + + align:start position:0% +Oh, great. Yep. Pottery seems like a + + + align:start position:0% +Oh, great. Yep. Pottery seems like a +good one. Learning how to swim. Learning + + align:start position:0% +good one. Learning how to swim. Learning + + + align:start position:0% +good one. Learning how to swim. Learning +how to swim was all right. We're saying + + align:start position:0% +how to swim was all right. We're saying + + + align:start position:0% +how to swim was all right. We're saying +a lot of physical things. Good. Video + + align:start position:0% +a lot of physical things. Good. Video + + + align:start position:0% +a lot of physical things. Good. Video +games. Video video games. Video games + + align:start position:0% +games. Video video games. Video games + + + align:start position:0% +games. Video video games. Video games +are a there is a whole science. Um + + align:start position:0% +are a there is a whole science. Um + + + align:start position:0% +are a there is a whole science. Um +there's a there we won't read it. + + align:start position:0% +there's a there we won't read it. + + + align:start position:0% +there's a there we won't read it. +There's a guy named James G um who wrote + + align:start position:0% +There's a guy named James G um who wrote + + + align:start position:0% +There's a guy named James G um who wrote +a great book about learning in video + + align:start position:0% +a great book about learning in video + + + align:start position:0% +a great book about learning in video +games. It's a little bit like Toqueville + + align:start position:0% +games. It's a little bit like Toqueville + + + align:start position:0% +games. It's a little bit like Toqueville +coming to America if that's a reference + + align:start position:0% +coming to America if that's a reference + + + align:start position:0% +coming to America if that's a reference +that you know. Um, but Toqueville was + + align:start position:0% +that you know. Um, but Toqueville was + + + align:start position:0% +that you know. Um, but Toqueville was +this European who came to America. Um, + + align:start position:0% +this European who came to America. Um, + + + align:start position:0% +this European who came to America. Um, +and he saw America incredibly intimately + + align:start position:0% +and he saw America incredibly intimately + + + align:start position:0% +and he saw America incredibly intimately +in a way that sort of only an outsider + + align:start position:0% +in a way that sort of only an outsider + + + align:start position:0% +in a way that sort of only an outsider +could by in part by becoming an insider. + + align:start position:0% +could by in part by becoming an insider. + + + align:start position:0% +could by in part by becoming an insider. +Um, James G is an old guy who was like, + + align:start position:0% +Um, James G is an old guy who was like, + + + align:start position:0% +Um, James G is an old guy who was like, +"Why do my kids like video games so + + align:start position:0% +"Why do my kids like video games so + + + align:start position:0% +"Why do my kids like video games so +much?" And he starts playing them a + + align:start position:0% +much?" And he starts playing them a + + + align:start position:0% +much?" And he starts playing them a +bunch. He's like, "These are amazing + + align:start position:0% +bunch. He's like, "These are amazing + + + align:start position:0% +bunch. He's like, "These are amazing +learning experiences." Um, think like + + align:start position:0% +learning experiences." Um, think like + + + align:start position:0% +learning experiences." Um, think like +think about someone learning a really + + align:start position:0% +think about someone learning a really + + + align:start position:0% +think about someone learning a really +hard game like Civilization 6 or + + align:start position:0% +hard game like Civilization 6 or + + + align:start position:0% +hard game like Civilization 6 or +Stellaris or put in whatever game you've + + align:start position:0% +Stellaris or put in whatever game you've + + + align:start position:0% +Stellaris or put in whatever game you've +been playing recently that just has like + + align:start position:0% +been playing recently that just has like + + + align:start position:0% +been playing recently that just has like +incredibly complicated systems in them. + + align:start position:0% +incredibly complicated systems in them. + + + align:start position:0% +incredibly complicated systems in them. +There aren't a lot of people who are + + align:start position:0% +There aren't a lot of people who are + + + align:start position:0% +There aren't a lot of people who are +like, you know, + + align:start position:0% +like, you know, + + + align:start position:0% +like, you know, +Minecraft like redstone building in + + align:start position:0% +Minecraft like redstone building in + + + align:start position:0% +Minecraft like redstone building in +Minecraft, stuff like that. There aren't + + align:start position:0% +Minecraft, stuff like that. There aren't + + + align:start position:0% +Minecraft, stuff like that. There aren't +people who are like, "God, it was such a + + align:start position:0% +people who are like, "God, it was such a + + + align:start position:0% +people who are like, "God, it was such a +drag that I had to take all those + + align:start position:0% +drag that I had to take all those + + + align:start position:0% +drag that I had to take all those +classes on redstone to be able to, you + + align:start position:0% +classes on redstone to be able to, you + + + align:start position:0% +classes on redstone to be able to, you +know, um these games have have systems + + align:start position:0% +know, um these games have have systems + + + align:start position:0% +know, um these games have have systems +built within them. They're sort of canot + + align:start position:0% +built within them. They're sort of canot + + + align:start position:0% +built within them. They're sort of canot +almost all them canonically situated + + align:start position:0% +almost all them canonically situated + + + align:start position:0% +almost all them canonically situated +kinds of things. Um where you're just + + align:start position:0% +kinds of things. Um where you're just + + + align:start position:0% +kinds of things. Um where you're just +immersed in the environment, you're + + align:start position:0% +immersed in the environment, you're + + + align:start position:0% +immersed in the environment, you're +encouraged to play. There are some peer + + align:start position:0% +encouraged to play. There are some peer + + + align:start position:0% +encouraged to play. There are some peer +structures around to help you learn and + + align:start position:0% +structures around to help you learn and + + + align:start position:0% +structures around to help you learn and +stuff like that. But it's extremely + + align:start position:0% +stuff like that. But it's extremely + + + align:start position:0% +stuff like that. But it's extremely +pleasant. um you know even even when um + + align:start position:0% +pleasant. um you know even even when um + + + align:start position:0% +pleasant. um you know even even when um +you know people might find it + + align:start position:0% +you know people might find it + + + align:start position:0% +you know people might find it +frustrating or things like that. I think + + align:start position:0% +frustrating or things like that. I think + + + align:start position:0% +frustrating or things like that. I think +a lot of in families cooking is + + align:start position:0% +a lot of in families cooking is + + + align:start position:0% +a lot of in families cooking is +something that learning how to cook + + align:start position:0% +something that learning how to cook + + + align:start position:0% +something that learning how to cook +which has both tactile and kind of + + align:start position:0% +which has both tactile and kind of + + + align:start position:0% +which has both tactile and kind of +scientific ma you know measurement + + align:start position:0% +scientific ma you know measurement + + + align:start position:0% +scientific ma you know measurement +mathematical language components um that + + align:start position:0% +mathematical language components um that + + + align:start position:0% +mathematical language components um that +people often find quite pleasurable. Uh + + align:start position:0% +people often find quite pleasurable. Uh + + + align:start position:0% +people often find quite pleasurable. Uh +and this connects a lot to like the + + align:start position:0% +and this connects a lot to like the + + + align:start position:0% +and this connects a lot to like the +material I'm learning in CMS 587 about + + align:start position:0% +material I'm learning in CMS 587 about + + + align:start position:0% +material I'm learning in CMS 587 about +assessments. We're learning like the + + align:start position:0% +assessments. We're learning like the + + + align:start position:0% +assessments. We're learning like the +different theories of intelligence and + + align:start position:0% +different theories of intelligence and + + + align:start position:0% +different theories of intelligence and +how um if you believe that your + + align:start position:0% +how um if you believe that your + + + align:start position:0% +how um if you believe that your +intelligence isn't fixed and like it can + + align:start position:0% +intelligence isn't fixed and like it can + + + align:start position:0% +intelligence isn't fixed and like it can +expand then you can learn a lot more. + + align:start position:0% +expand then you can learn a lot more. + + + align:start position:0% +expand then you can learn a lot more. +And that's kind of like young children + + align:start position:0% +And that's kind of like young children + + + align:start position:0% +And that's kind of like young children +or babies because they're not really + + align:start position:0% +or babies because they're not really + + + align:start position:0% +or babies because they're not really +afraid of failure and like they just + + align:start position:0% +afraid of failure and like they just + + + align:start position:0% +afraid of failure and like they just +like they're very resilient. So yeah. + + align:start position:0% +like they're very resilient. So yeah. + + + align:start position:0% +like they're very resilient. So yeah. +Yeah. Yeah. They don't they don't care + + align:start position:0% +Yeah. Yeah. They don't they don't care + + + align:start position:0% +Yeah. Yeah. They don't they don't care +what's going on. They're just trying to + + align:start position:0% +what's going on. They're just trying to + + + align:start position:0% +what's going on. They're just trying to +figure things out. Um how many of you + + align:start position:0% +figure things out. Um how many of you + + + align:start position:0% +figure things out. Um how many of you +have have had uh experiences that you're + + align:start position:0% +have have had uh experiences that you're + + + align:start position:0% +have have had uh experiences that you're +really happy with where learning was + + align:start position:0% +really happy with where learning was + + + align:start position:0% +really happy with where learning was +hard where you like persevered through + + align:start position:0% +hard where you like persevered through + + + align:start position:0% +hard where you like persevered through +sort of a challenging set of learning + + align:start position:0% +sort of a challenging set of learning + + + align:start position:0% +sort of a challenging set of learning +experiences and got better at it and you + + align:start position:0% +experiences and got better at it and you + + + align:start position:0% +experiences and got better at it and you +were like, "Yeah, that's great. I'm + + align:start position:0% +were like, "Yeah, that's great. I'm + + + align:start position:0% +were like, "Yeah, that's great. I'm +super glad I did that." What what things + + align:start position:0% +super glad I did that." What what things + + + align:start position:0% +super glad I did that." What what things +come to mind for that for you? I think + + align:start position:0% +come to mind for that for you? I think + + + align:start position:0% +come to mind for that for you? I think +for me learning to code was a bit like + + align:start position:0% +for me learning to code was a bit like + + + align:start position:0% +for me learning to code was a bit like +that. I think differently from some + + align:start position:0% +that. I think differently from some + + + align:start position:0% +that. I think differently from some +people in the room like I didn't learn + + align:start position:0% +people in the room like I didn't learn + + + align:start position:0% +people in the room like I didn't learn +to code in middle school. I learned it + + align:start position:0% +to code in middle school. I learned it + + + align:start position:0% +to code in middle school. I learned it +in university. So there were like + + align:start position:0% +in university. So there were like + + + align:start position:0% +in university. So there were like +degrees associated with it and things + + align:start position:0% +degrees associated with it and things + + + align:start position:0% +degrees associated with it and things +like that. Yeah. Yeah. You watched a + + align:start position:0% +like that. Yeah. Yeah. You watched a + + + align:start position:0% +like that. Yeah. Yeah. You watched a +bunch of lectures and did pet sets and + + align:start position:0% +bunch of lectures and did pet sets and + + + align:start position:0% +bunch of lectures and did pet sets and +turn them in and but I remember like the + + align:start position:0% +turn them in and but I remember like the + + + align:start position:0% +turn them in and but I remember like the +first very complex pet that I completed + + align:start position:0% +first very complex pet that I completed + + + align:start position:0% +first very complex pet that I completed +and like my program worked perfectly and + + align:start position:0% +and like my program worked perfectly and + + + align:start position:0% +and like my program worked perfectly and +I was like it's amazing feeling. It felt + + align:start position:0% +I was like it's amazing feeling. It felt + + + align:start position:0% +I was like it's amazing feeling. It felt +it felt very satisfying even though some + + align:start position:0% +it felt very satisfying even though some + + + align:start position:0% +it felt very satisfying even though some +of the learning experience of doing + + align:start position:0% +of the learning experience of doing + + + align:start position:0% +of the learning experience of doing +that. Yeah. Yeah. So that that kind of + + align:start position:0% +that. Yeah. Yeah. So that that kind of + + + align:start position:0% +that. Yeah. Yeah. So that that kind of +that you know I think there's sort of a + + align:start position:0% +that you know I think there's sort of a + + + align:start position:0% +that you know I think there's sort of a +moral story that emerges around a lot of + + align:start position:0% +moral story that emerges around a lot of + + + align:start position:0% +moral story that emerges around a lot of +instructionist learning which is like it + + align:start position:0% +instructionist learning which is like it + + + align:start position:0% +instructionist learning which is like it +was hard we put our nose to the + + align:start position:0% +was hard we put our nose to the + + + align:start position:0% +was hard we put our nose to the +grindstoneone we sacrificed but after + + align:start position:0% +grindstoneone we sacrificed but after + + + align:start position:0% +grindstoneone we sacrificed but after +that sacrifice we had this great feeling + + align:start position:0% +that sacrifice we had this great feeling + + + align:start position:0% +that sacrifice we had this great feeling +of relief and I think most of us have + + align:start position:0% +of relief and I think most of us have + + + align:start position:0% +of relief and I think most of us have +some kind of learning experience that + + align:start position:0% +some kind of learning experience that + + + align:start position:0% +some kind of learning experience that +goes like that and then situated + + align:start position:0% +goes like that and then situated + + + align:start position:0% +goes like that and then situated +learning people have more of this story + + align:start position:0% +learning people have more of this story + + + align:start position:0% +learning people have more of this story +of like we just naturally found + + align:start position:0% +of like we just naturally found + + + align:start position:0% +of like we just naturally found +ourselves in this space surrounded by + + align:start position:0% +ourselves in this space surrounded by + + + align:start position:0% +ourselves in this space surrounded by +opportunities to learn and it was + + align:start position:0% +opportunities to learn and it was + + + align:start position:0% +opportunities to learn and it was +playful and it felt easy and natural and + + align:start position:0% +playful and it felt easy and natural and + + + align:start position:0% +playful and it felt easy and natural and +that's what we're trying to sort of + + align:start position:0% +that's what we're trying to sort of + + + align:start position:0% +that's what we're trying to sort of +restore So actually the cognitive load + + align:start position:0% +restore So actually the cognitive load + + + align:start position:0% +restore So actually the cognitive load +theorists have to me what I think is + + align:start position:0% +theorists have to me what I think is + + + align:start position:0% +theorists have to me what I think is +sort of a funny way of dealing with + + align:start position:0% +sort of a funny way of dealing with + + + align:start position:0% +sort of a funny way of dealing with +this. Um there was just a guy who + + align:start position:0% +this. Um there was just a guy who + + + align:start position:0% +this. Um there was just a guy who +proposed that there's two categories of + + align:start position:0% +proposed that there's two categories of + + + align:start position:0% +proposed that there's two categories of +things that are learned called + + align:start position:0% +things that are learned called + + + align:start position:0% +things that are learned called +biologically primary and biologically + + align:start position:0% +biologically primary and biologically + + + align:start position:0% +biologically primary and biologically +secondary kinds of things. Um and uh + + align:start position:0% +secondary kinds of things. Um and uh + + + align:start position:0% +secondary kinds of things. Um and uh +we're evolutionarily wired to naturally + + align:start position:0% +we're evolutionarily wired to naturally + + + align:start position:0% +we're evolutionarily wired to naturally +learn biologically primary kinds of + + align:start position:0% +learn biologically primary kinds of + + + align:start position:0% +learn biologically primary kinds of +things and everything else is + + align:start position:0% +things and everything else is + + + align:start position:0% +things and everything else is +biologically secondary and is much + + align:start position:0% +biologically secondary and is much + + + align:start position:0% +biologically secondary and is much +harder. So that you're sort of naturally + + align:start position:0% +harder. So that you're sort of naturally + + + align:start position:0% +harder. So that you're sort of naturally +wired to learn how to walk, how to eat, + + align:start position:0% +wired to learn how to walk, how to eat, + + + align:start position:0% +wired to learn how to walk, how to eat, +some basic parts of socializing, + + align:start position:0% +some basic parts of socializing, + + + align:start position:0% +some basic parts of socializing, +recognizing faces. Language ends up + + align:start position:0% +recognizing faces. Language ends up + + + align:start position:0% +recognizing faces. Language ends up +being a real problem for this because + + align:start position:0% +being a real problem for this because + + + align:start position:0% +being a real problem for this because +it's like are you biologically primed to + + align:start position:0% +it's like are you biologically primed to + + + align:start position:0% +it's like are you biologically primed to +learn your first language to learn + + align:start position:0% +learn your first language to learn + + + align:start position:0% +learn your first language to learn +multiple languages? Why would you be + + align:start position:0% +multiple languages? Why would you be + + + align:start position:0% +multiple languages? Why would you be +biologic? Like why was it easy for me to + + align:start position:0% +biologic? Like why was it easy for me to + + + align:start position:0% +biologic? Like why was it easy for me to +learn English when I was young, but not + + align:start position:0% +learn English when I was young, but not + + + align:start position:0% +learn English when I was young, but not +Spanish was really hard when I was + + align:start position:0% +Spanish was really hard when I was + + + align:start position:0% +Spanish was really hard when I was +older? Like my brain changed? Did + + align:start position:0% +older? Like my brain changed? Did + + + align:start position:0% +older? Like my brain changed? Did +evolution? Like anyway, um I actually + + align:start position:0% +evolution? Like anyway, um I actually + + + align:start position:0% +evolution? Like anyway, um I actually +find this theory totally unsatisfying. + + align:start position:0% +find this theory totally unsatisfying. + + + align:start position:0% +find this theory totally unsatisfying. +Um do do you are familiar with the idea + + align:start position:0% +Um do do you are familiar with the idea + + + align:start position:0% +Um do do you are familiar with the idea +of epicycles? Um like before the + + align:start position:0% +of epicycles? Um like before the + + + align:start position:0% +of epicycles? Um like before the +capernican revolution uh we uh everybody + + align:start position:0% +capernican revolution uh we uh everybody + + + align:start position:0% +capernican revolution uh we uh everybody +thought orbits were circles not you know + + align:start position:0% +thought orbits were circles not you know + + + align:start position:0% +thought orbits were circles not you know +uh ovals or or whatever it is that + + align:start position:0% +uh ovals or or whatever it is that + + + align:start position:0% +uh ovals or or whatever it is that +they're what is it? What's the shape of + + align:start position:0% +they're what is it? What's the shape of + + + align:start position:0% +they're what is it? What's the shape of +them? Ellipses. Um and so there was a + + align:start position:0% +them? Ellipses. Um and so there was a + + + align:start position:0% +them? Ellipses. Um and so there was a +period of time when they realized like + + align:start position:0% +period of time when they realized like + + + align:start position:0% +period of time when they realized like +oh circle measurements don't work. And + + align:start position:0% +oh circle measurements don't work. And + + + align:start position:0% +oh circle measurements don't work. And +so they added circles to the circles. Um + + align:start position:0% +so they added circles to the circles. Um + + + align:start position:0% +so they added circles to the circles. Um +there they like believed that there had + + align:start position:0% +there they like believed that there had + + + align:start position:0% +there they like believed that there had +to be sort of perfect circles making the + + align:start position:0% +to be sort of perfect circles making the + + + align:start position:0% +to be sort of perfect circles making the +orbits. And so they believed that + + align:start position:0% +orbits. And so they believed that + + + align:start position:0% +orbits. And so they believed that +somehow there were like orbits within + + align:start position:0% +somehow there were like orbits within + + + align:start position:0% +somehow there were like orbits within +the orbits. um you know and then I think + + align:start position:0% +the orbits. um you know and then I think + + + align:start position:0% +the orbits. um you know and then I think +it was capergus who came around was like + + align:start position:0% +it was capergus who came around was like + + + align:start position:0% +it was capergus who came around was like +actually it's just like this and that + + align:start position:0% +actually it's just like this and that + + + align:start position:0% +actually it's just like this and that +works a lot better but to me sort of + + align:start position:0% +works a lot better but to me sort of + + + align:start position:0% +works a lot better but to me sort of +biologically primary and biologically + + align:start position:0% +biologically primary and biologically + + + align:start position:0% +biologically primary and biologically +secondary thing sort of operate that + + align:start position:0% +secondary thing sort of operate that + + + align:start position:0% +secondary thing sort of operate that +like that seems a little bit like an + + align:start position:0% +like that seems a little bit like an + + + align:start position:0% +like that seems a little bit like an +epicycle to me like we haven't quite + + align:start position:0% +epicycle to me like we haven't quite + + + align:start position:0% +epicycle to me like we haven't quite +figured out um what's going on there but + + align:start position:0% +figured out um what's going on there but + + + align:start position:0% +figured out um what's going on there but +that is how um canonically the the + + align:start position:0% +that is how um canonically the the + + + align:start position:0% +that is how um canonically the the +cognitive load theory people just wave + + align:start position:0% +cognitive load theory people just wave + + + align:start position:0% +cognitive load theory people just wave +all this away and say ah but babies + + align:start position:0% +all this away and say ah but babies + + + align:start position:0% +all this away and say ah but babies +whatever biologically primary we don't + + align:start position:0% +whatever biologically primary we don't + + + align:start position:0% +whatever biologically primary we don't +have to worry about them um everything + + align:start position:0% +have to worry about them um everything + + + align:start position:0% +have to worry about them um everything +after you're four years old or something + + align:start position:0% +after you're four years old or something + + + align:start position:0% +after you're four years old or something +like that is uh cognitive load theory + + align:start position:0% +like that is uh cognitive load theory + + + align:start position:0% +like that is uh cognitive load theory +works um But for the situated learning + + align:start position:0% +works um But for the situated learning + + + align:start position:0% +works um But for the situated learning +people, you know, not not exactly, but + + align:start position:0% +people, you know, not not exactly, but + + + align:start position:0% +people, you know, not not exactly, but +in a lot of ways, they're trying to sort + + align:start position:0% +in a lot of ways, they're trying to sort + + + align:start position:0% +in a lot of ways, they're trying to sort +of recapture the learning experiences + + align:start position:0% +of recapture the learning experiences + + + align:start position:0% +of recapture the learning experiences +that we have when we're very young. Um, + + align:start position:0% +that we have when we're very young. Um, + + + align:start position:0% +that we have when we're very young. Um, +where where learning is natural, + + align:start position:0% +where where learning is natural, + + + align:start position:0% +where where learning is natural, +playful, not always happy, but often + + align:start position:0% +playful, not always happy, but often + + + align:start position:0% +playful, not always happy, but often +sort of socially satisfying. Um, and + + align:start position:0% +sort of socially satisfying. Um, and + + + align:start position:0% +sort of socially satisfying. Um, and +extremely effective. I mean, what babies + + align:start position:0% +extremely effective. I mean, what babies + + + align:start position:0% +extremely effective. I mean, what babies +learn in a short period of time is just + + align:start position:0% +learn in a short period of time is just + + + align:start position:0% +learn in a short period of time is just +bonkers. Um, it's one of the most fun + + align:start position:0% +bonkers. Um, it's one of the most fun + + + align:start position:0% +bonkers. Um, it's one of the most fun +things about being a parent or an auntie + + align:start position:0% +things about being a parent or an auntie + + + align:start position:0% +things about being a parent or an auntie +or a uncle or all the other ways you get + + align:start position:0% +or a uncle or all the other ways you get + + + align:start position:0% +or a uncle or all the other ways you get +to spend a lot of time with kids. Okay. + + align:start position:0% +to spend a lot of time with kids. Okay. + + + align:start position:0% +to spend a lot of time with kids. Okay. +Um, let's just get oriented + + align:start position:0% + + + + align:start position:0% + +here. So, again, we're in foundations. + + align:start position:0% +here. So, again, we're in foundations. + + + align:start position:0% +here. So, again, we're in foundations. +Um, we're trying to get a hand of these + + align:start position:0% +Um, we're trying to get a hand of these + + + align:start position:0% +Um, we're trying to get a hand of these +two sort of contemporary learning + + align:start position:0% +two sort of contemporary learning + + + align:start position:0% +two sort of contemporary learning +theories. Cognitive load theory, + + align:start position:0% +theories. Cognitive load theory, + + + align:start position:0% +theories. Cognitive load theory, +situated learning. Um, that these two + + align:start position:0% +situated learning. Um, that these two + + + align:start position:0% +situated learning. Um, that these two +ideas about how people learn are + + align:start position:0% +ideas about how people learn are + + + align:start position:0% +ideas about how people learn are +ancient. Um, that you can find people + + align:start position:0% +ancient. Um, that you can find people + + + align:start position:0% +ancient. Um, that you can find people +like Plutarch for the mind does not + + align:start position:0% +like Plutarch for the mind does not + + + align:start position:0% +like Plutarch for the mind does not +require filling like a bottle, but + + align:start position:0% +require filling like a bottle, but + + + align:start position:0% +require filling like a bottle, but +rather like wood. It only requires + + align:start position:0% +rather like wood. It only requires + + + align:start position:0% +rather like wood. It only requires +kindling to create in it an impulse to + + align:start position:0% +kindling to create in it an impulse to + + + align:start position:0% +kindling to create in it an impulse to +think independently and an ardent desire + + align:start position:0% +think independently and an ardent desire + + + align:start position:0% +think independently and an ardent desire +for truth. That's the sort of like this + + align:start position:0% +for truth. That's the sort of like this + + + align:start position:0% +for truth. That's the sort of like this +is Plutarch making a case for situated + + align:start position:0% +is Plutarch making a case for situated + + + align:start position:0% +is Plutarch making a case for situated +learning and against cognitive load + + align:start position:0% +learning and against cognitive load + + + align:start position:0% +learning and against cognitive load +theory, though he wouldn't have known + + align:start position:0% +theory, though he wouldn't have known + + + align:start position:0% +theory, though he wouldn't have known +those terms because they didn't show up + + align:start position:0% +those terms because they didn't show up + + + align:start position:0% +those terms because they didn't show up +for another 2,000 years. Um, but you can + + align:start position:0% +for another 2,000 years. Um, but you can + + + align:start position:0% +for another 2,000 years. Um, but you can +hear the resonance of the debate in his + + align:start position:0% +hear the resonance of the debate in his + + + align:start position:0% +hear the resonance of the debate in his +mind. Here's a little chunk from a 2017 + + align:start position:0% +mind. Here's a little chunk from a 2017 + + + align:start position:0% +mind. Here's a little chunk from a 2017 +New Yorker article. For nearly a + + align:start position:0% +New Yorker article. For nearly a + + + align:start position:0% +New Yorker article. For nearly a +century, public education in America has + + align:start position:0% +century, public education in America has + + + align:start position:0% +century, public education in America has +been influenced by two opposing + + align:start position:0% +been influenced by two opposing + + + align:start position:0% +been influenced by two opposing +pedagogical approaches. Traditionalism + + align:start position:0% +pedagogical approaches. Traditionalism + + + align:start position:0% +pedagogical approaches. Traditionalism +and progressivism. The thing that you + + align:start position:0% +and progressivism. The thing that you + + + align:start position:0% +and progressivism. The thing that you +got to catch is that there are these two + + align:start position:0% +got to catch is that there are these two + + + align:start position:0% +got to catch is that there are these two +ideas that have like each of them has + + align:start position:0% +ideas that have like each of them has + + + align:start position:0% +ideas that have like each of them has +8,000 different names. But anytime you + + align:start position:0% +8,000 different names. But anytime you + + + align:start position:0% +8,000 different names. But anytime you +sort of notice this dichconomy, broadly + + align:start position:0% +sort of notice this dichconomy, broadly + + + align:start position:0% +sort of notice this dichconomy, broadly +speaking, in the traditional approach to + + align:start position:0% +speaking, in the traditional approach to + + + align:start position:0% +speaking, in the traditional approach to +education, a teacher imparts knowledge + + align:start position:0% +education, a teacher imparts knowledge + + + align:start position:0% +education, a teacher imparts knowledge +to students through direct instruction + + align:start position:0% +to students through direct instruction + + + align:start position:0% +to students through direct instruction +and embodies a disciplinary culture in + + align:start position:0% +and embodies a disciplinary culture in + + + align:start position:0% +and embodies a disciplinary culture in +which obedience is both prized and + + align:start position:0% +which obedience is both prized and + + + align:start position:0% +which obedience is both prized and +rewarded. That's a that's a nice both + + align:start position:0% +rewarded. That's a that's a nice both + + + align:start position:0% +rewarded. That's a that's a nice both +like so like she frames it here's a + + align:start position:0% +like so like she frames it here's a + + + align:start position:0% +like so like she frames it here's a +pedagogical piece. Knowledge is imparted + + align:start position:0% +pedagogical piece. Knowledge is imparted + + + align:start position:0% +pedagogical piece. Knowledge is imparted +through direct instruction and embodies + + align:start position:0% +through direct instruction and embodies + + + align:start position:0% +through direct instruction and embodies +a disciplinary culture in which + + align:start position:0% +a disciplinary culture in which + + + align:start position:0% +a disciplinary culture in which +obedience is prized and rewarded. like + + align:start position:0% +obedience is prized and rewarded. like + + + align:start position:0% +obedience is prized and rewarded. like +obedience was not prized and rewarded + + align:start position:0% +obedience was not prized and rewarded + + + align:start position:0% +obedience was not prized and rewarded +amongst the baby on the playground. What + + align:start position:0% +amongst the baby on the playground. What + + + align:start position:0% +amongst the baby on the playground. What +was rewarded was screwing around. Um the + + align:start position:0% +was rewarded was screwing around. Um the + + + align:start position:0% +was rewarded was screwing around. Um the +purpose of the classroom is to equip all + + align:start position:0% +purpose of the classroom is to equip all + + + align:start position:0% +purpose of the classroom is to equip all +students to meet measurable academic + + align:start position:0% +students to meet measurable academic + + + align:start position:0% +students to meet measurable academic +standards. At progressive institutions, + + align:start position:0% +standards. At progressive institutions, + + + align:start position:0% +standards. At progressive institutions, +a teacher develops a curriculum but + + align:start position:0% +a teacher develops a curriculum but + + + align:start position:0% +a teacher develops a curriculum but +urges students to treat it as a staging + + align:start position:0% +urges students to treat it as a staging + + + align:start position:0% +urges students to treat it as a staging +ground for their own intellectual + + align:start position:0% +ground for their own intellectual + + + align:start position:0% +ground for their own intellectual +discoveries, often through hands-on + + align:start position:0% +discoveries, often through hands-on + + + align:start position:0% +discoveries, often through hands-on +activity and group work. Allowances are + + align:start position:0% +activity and group work. Allowances are + + + align:start position:0% +activity and group work. Allowances are +made for differences in the way + + align:start position:0% +made for differences in the way + + + align:start position:0% +made for differences in the way +individual students learn. Progressivism + + align:start position:0% +individual students learn. Progressivism + + + align:start position:0% +individual students learn. Progressivism +was inspired in large part by the work + + align:start position:0% +was inspired in large part by the work + + + align:start position:0% +was inspired in large part by the work +of John Dwey, the American philosopher + + align:start position:0% +of John Dwey, the American philosopher + + + align:start position:0% +of John Dwey, the American philosopher +and education theorist. Um maybe I'll + + align:start position:0% +and education theorist. Um maybe I'll + + + align:start position:0% +and education theorist. Um maybe I'll +say that last name. For Dwey, the + + align:start position:0% +say that last name. For Dwey, the + + + align:start position:0% +say that last name. For Dwey, the +classroom was not simply a place for + + align:start position:0% +classroom was not simply a place for + + + align:start position:0% +classroom was not simply a place for +acquiring academic credentials. It was + + align:start position:0% +acquiring academic credentials. It was + + + align:start position:0% +acquiring academic credentials. It was +also a venue in which students learned + + align:start position:0% +also a venue in which students learned + + + align:start position:0% +also a venue in which students learned +crucial values about being citizens in a + + align:start position:0% +crucial values about being citizens in a + + + align:start position:0% +crucial values about being citizens in a +democracy. So maybe maybe these things + + align:start position:0% +democracy. So maybe maybe these things + + + align:start position:0% +democracy. So maybe maybe these things +are laden not just with pedagogical + + align:start position:0% +are laden not just with pedagogical + + + align:start position:0% +are laden not just with pedagogical +ideas, beliefs about human architecture, + + align:start position:0% +ideas, beliefs about human architecture, + + + align:start position:0% +ideas, beliefs about human architecture, +um cultural sort of values, but even + + align:start position:0% +um cultural sort of values, but even + + + align:start position:0% +um cultural sort of values, but even +maybe the outcomes of education. Maybe + + align:start position:0% +maybe the outcomes of education. Maybe + + + align:start position:0% +maybe the outcomes of education. Maybe +we believe differently about that, + + align:start position:0% +we believe differently about that, + + + align:start position:0% +we believe differently about that, +though not necessarily. Um the person + + align:start position:0% +though not necessarily. Um the person + + + align:start position:0% +though not necessarily. Um the person +who's probably the best counterpoint to + + align:start position:0% +who's probably the best counterpoint to + + + align:start position:0% +who's probably the best counterpoint to +John Dwey is this guy Ed Thorndikeke. um + + align:start position:0% +John Dwey is this guy Ed Thorndikeke. um + + + align:start position:0% +John Dwey is this guy Ed Thorndikeke. um +who is a very early educational + + align:start position:0% +who is a very early educational + + + align:start position:0% +who is a very early educational +psychologist. I often think of him as + + align:start position:0% +psychologist. I often think of him as + + + align:start position:0% +psychologist. I often think of him as +the guy who is like no no no pale + + align:start position:0% +the guy who is like no no no pale + + + align:start position:0% +the guy who is like no no no pale +filling is great. Um like a particularly + + align:start position:0% +filling is great. Um like a particularly + + + align:start position:0% +filling is great. Um like a particularly +great thing about pale filling is that + + align:start position:0% +great thing about pale filling is that + + + align:start position:0% +great thing about pale filling is that +we can measure pale filling. You can + + align:start position:0% +we can measure pale filling. You can + + + align:start position:0% +we can measure pale filling. You can +measure like the rate at which you bore + + align:start position:0% +measure like the rate at which you bore + + + align:start position:0% +measure like the rate at which you bore +things into people and the rate at which + + align:start position:0% +things into people and the rate at which + + + align:start position:0% +things into people and the rate at which +it falls out and how leaky people are um + + align:start position:0% +it falls out and how leaky people are um + + + align:start position:0% +it falls out and how leaky people are um +and some of those kinds of things. So he + + align:start position:0% +and some of those kinds of things. So he + + + align:start position:0% +and some of those kinds of things. So he +was very involved in testing. Um he + + align:start position:0% +was very involved in testing. Um he + + + align:start position:0% +was very involved in testing. Um he +actually um played a really important + + align:start position:0% +actually um played a really important + + + align:start position:0% +actually um played a really important +role in developing ideas that + + align:start position:0% +role in developing ideas that + + + align:start position:0% +role in developing ideas that +educational progressives uh hold dearly. + + align:start position:0% +educational progressives uh hold dearly. + + + align:start position:0% +educational progressives uh hold dearly. +He's one of the things he studied which + + align:start position:0% +He's one of the things he studied which + + + align:start position:0% +He's one of the things he studied which +we'll talk about the course goes on is + + align:start position:0% +we'll talk about the course goes on is + + + align:start position:0% +we'll talk about the course goes on is +this idea of transfer. Um so uh uh you + + align:start position:0% +this idea of transfer. Um so uh uh you + + + align:start position:0% +this idea of transfer. Um so uh uh you +know in the 18th 19th century people in + + align:start position:0% +know in the 18th 19th century people in + + + align:start position:0% +know in the 18th 19th century people in +America Europe believed that a great + + align:start position:0% +America Europe believed that a great + + + align:start position:0% +America Europe believed that a great +thing about learning Latin and Greek was + + align:start position:0% +thing about learning Latin and Greek was + + + align:start position:0% +thing about learning Latin and Greek was +it sort of strengthened these kind of + + align:start position:0% +it sort of strengthened these kind of + + + align:start position:0% +it sort of strengthened these kind of +like generic thinking muscles. Like if + + align:start position:0% +like generic thinking muscles. Like if + + + align:start position:0% +like generic thinking muscles. Like if +you got really good at learning Latin + + align:start position:0% +you got really good at learning Latin + + + align:start position:0% +you got really good at learning Latin +and Greek you would just be a good + + align:start position:0% +and Greek you would just be a good + + + align:start position:0% +and Greek you would just be a good +thinker. And he was like that's dumb. Um + + align:start position:0% +thinker. And he was like that's dumb. Um + + + align:start position:0% +thinker. And he was like that's dumb. Um +if you learn Latin and Greek you're good + + align:start position:0% +if you learn Latin and Greek you're good + + + align:start position:0% +if you learn Latin and Greek you're good +at Latin and Greek but you're not + + align:start position:0% +at Latin and Greek but you're not + + + align:start position:0% +at Latin and Greek but you're not +actually good at anything else. um like + + align:start position:0% +actually good at anything else. um like + + + align:start position:0% +actually good at anything else. um like +the brain is not general purpose like + + align:start position:0% +the brain is not general purpose like + + + align:start position:0% +the brain is not general purpose like +that but that kind of thinking that kind + + align:start position:0% +that but that kind of thinking that kind + + + align:start position:0% +that but that kind of thinking that kind +of thinking if I learn this thing it'll + + align:start position:0% +of thinking if I learn this thing it'll + + + align:start position:0% +of thinking if I learn this thing it'll +help me like generically with these + + align:start position:0% +help me like generically with these + + + align:start position:0% +help me like generically with these +other things shows up all the time. Um + + align:start position:0% +other things shows up all the time. Um + + + align:start position:0% +other things shows up all the time. Um +the most contemporary uh version of this + + align:start position:0% +the most contemporary uh version of this + + + align:start position:0% +the most contemporary uh version of this +is have any of you ever encountered the + + align:start position:0% +is have any of you ever encountered the + + + align:start position:0% +is have any of you ever encountered the +idea of computational thinking. What + + align:start position:0% +idea of computational thinking. What + + + align:start position:0% +idea of computational thinking. What +people mean by computational thinking + + align:start position:0% +people mean by computational thinking + + + align:start position:0% +people mean by computational thinking +almost all the time is like we're going + + align:start position:0% +almost all the time is like we're going + + + align:start position:0% +almost all the time is like we're going +to teach you computer programming and if + + align:start position:0% +to teach you computer programming and if + + + align:start position:0% +to teach you computer programming and if +you learn about computer programming + + align:start position:0% +you learn about computer programming + + + align:start position:0% +you learn about computer programming +you're going to learn how to like break + + align:start position:0% +you're going to learn how to like break + + + align:start position:0% +you're going to learn how to like break +ideas down into smaller parts and you're + + align:start position:0% +ideas down into smaller parts and you're + + + align:start position:0% +ideas down into smaller parts and you're +going to learn how to think + + align:start position:0% +going to learn how to think + + + align:start position:0% +going to learn how to think +algorithmically and do all these other + + align:start position:0% +algorithmically and do all these other + + + align:start position:0% +algorithmically and do all these other +sort of and it's like no you're going to + + align:start position:0% +sort of and it's like no you're going to + + + align:start position:0% +sort of and it's like no you're going to +be good at programming computers. Um you + + align:start position:0% +be good at programming computers. Um you + + + align:start position:0% +be good at programming computers. Um you +know if you want to be able to break + + align:start position:0% +know if you want to be able to break + + + align:start position:0% +know if you want to be able to break +ideas down in poetry learning computer + + align:start position:0% +ideas down in poetry learning computer + + + align:start position:0% +ideas down in poetry learning computer +programming will not help you do that + + align:start position:0% +programming will not help you do that + + + align:start position:0% +programming will not help you do that +anymore. I mean it will help you about + + align:start position:0% +anymore. I mean it will help you about + + + align:start position:0% +anymore. I mean it will help you about +as much as learning Latin and Greek will + + align:start position:0% +as much as learning Latin and Greek will + + + align:start position:0% +as much as learning Latin and Greek will +help you do that which is to say like + + align:start position:0% +help you do that which is to say like + + + align:start position:0% +help you do that which is to say like +not that much. um that a frustrating + + align:start position:0% +not that much. um that a frustrating + + + align:start position:0% +not that much. um that a frustrating +thing about teaching is the things we + + align:start position:0% +thing about teaching is the things we + + + align:start position:0% +thing about teaching is the things we +learn um tend to only help us in like + + align:start position:0% +learn um tend to only help us in like + + + align:start position:0% +learn um tend to only help us in like +very near cognate areas. Um so these are + + align:start position:0% +very near cognate areas. Um so these are + + + align:start position:0% +very near cognate areas. Um so these are +sort of the two kind of you know again + + align:start position:0% +sort of the two kind of you know again + + + align:start position:0% +sort of the two kind of you know again +I'm trying to give you the sense that + + align:start position:0% +I'm trying to give you the sense that + + + align:start position:0% +I'm trying to give you the sense that +like these two big ideas are millennia + + align:start position:0% +like these two big ideas are millennia + + + align:start position:0% +like these two big ideas are millennia +old. They have a scientific basis that's + + align:start position:0% +old. They have a scientific basis that's + + + align:start position:0% +old. They have a scientific basis that's +at least a century old. Um and you're + + align:start position:0% +at least a century old. Um and you're + + + align:start position:0% +at least a century old. Um and you're +getting what I think are some of the + + align:start position:0% +getting what I think are some of the + + + align:start position:0% +getting what I think are some of the +best most recent contemporary uh + + align:start position:0% +best most recent contemporary uh + + + align:start position:0% +best most recent contemporary uh +formulations. Um like the work of John + + align:start position:0% +formulations. Um like the work of John + + + align:start position:0% +formulations. Um like the work of John +Sweller and some of these other folks + + align:start position:0% +Sweller and some of these other folks + + + align:start position:0% +Sweller and some of these other folks +like the little piece you read from + + align:start position:0% +like the little piece you read from + + + align:start position:0% +like the little piece you read from +Mitch Resnik for today. Um and then + + align:start position:0% +Mitch Resnik for today. Um and then + + + align:start position:0% +Mitch Resnik for today. Um and then +maybe just to give you like a broader + + align:start position:0% +maybe just to give you like a broader + + + align:start position:0% +maybe just to give you like a broader +overview like overwhelmingly Thorndikeke + + align:start position:0% +overview like overwhelmingly Thorndikeke + + + align:start position:0% +overview like overwhelmingly Thorndikeke +is one. Um if you were to walk through a + + align:start position:0% +is one. Um if you were to walk through a + + + align:start position:0% +is one. Um if you were to walk through a +typical American school in a typical + + align:start position:0% +typical American school in a typical + + + align:start position:0% +typical American school in a typical +American day, you would see very little + + align:start position:0% +American day, you would see very little + + + align:start position:0% +American day, you would see very little +education is life itself and you would + + align:start position:0% +education is life itself and you would + + + align:start position:0% +education is life itself and you would +see a lot of direct instruction. Um like + + align:start position:0% +see a lot of direct instruction. Um like + + + align:start position:0% +see a lot of direct instruction. Um like +the the canonical experience of students + + align:start position:0% +the the canonical experience of students + + + align:start position:0% +the the canonical experience of students +in schools is very organized around + + align:start position:0% +in schools is very organized around + + + align:start position:0% +in schools is very organized around +direct instruction. However, if you were + + align:start position:0% +direct instruction. However, if you were + + + align:start position:0% +direct instruction. However, if you were +to ask teachers who their favorite um + + align:start position:0% +to ask teachers who their favorite um + + + align:start position:0% +to ask teachers who their favorite um +educational philosopher is, you would + + align:start position:0% +educational philosopher is, you would + + + align:start position:0% +educational philosopher is, you would +get a lot of answers that are Dewey and + + align:start position:0% +get a lot of answers that are Dewey and + + + align:start position:0% +get a lot of answers that are Dewey and +you would not get a lot of answers that + + align:start position:0% +you would not get a lot of answers that + + + align:start position:0% +you would not get a lot of answers that +were Thorndikeke. Um so the um Dewey is + + align:start position:0% +were Thorndikeke. Um so the um Dewey is + + + align:start position:0% +were Thorndikeke. Um so the um Dewey is +beloved in a way that Thorndikeke is + + align:start position:0% +beloved in a way that Thorndikeke is + + + align:start position:0% +beloved in a way that Thorndikeke is +not. But Thorndikeke is like actually + + align:start position:0% +not. But Thorndikeke is like actually + + + align:start position:0% +not. But Thorndikeke is like actually +the person who uh inspires more of our + + align:start position:0% +the person who uh inspires more of our + + + align:start position:0% +the person who uh inspires more of our +ideas. All right, let's do just a little + + align:start position:0% +ideas. All right, let's do just a little + + + align:start position:0% +ideas. All right, let's do just a little +bit of close reading together, which is + + align:start position:0% +bit of close reading together, which is + + + align:start position:0% +bit of close reading together, which is +mostly me telling you about some things + + align:start position:0% +mostly me telling you about some things + + + align:start position:0% +mostly me telling you about some things +that you should read closely. This is + + align:start position:0% +that you should read closely. This is + + + align:start position:0% +that you should read closely. This is +what we looked at yesterday. Here's um + + align:start position:0% +what we looked at yesterday. Here's um + + + align:start position:0% +what we looked at yesterday. Here's um +one thing that's fun about the um + + align:start position:0% +one thing that's fun about the um + + + align:start position:0% +one thing that's fun about the um +cognitive load theory people is that + + align:start position:0% +cognitive load theory people is that + + + align:start position:0% +cognitive load theory people is that +they have they're really good at stating + + align:start position:0% +they have they're really good at stating + + + align:start position:0% +they have they're really good at stating +clearly what their models of human + + align:start position:0% +clearly what their models of human + + + align:start position:0% +clearly what their models of human +cognitive architecture are. I think the + + align:start position:0% +cognitive architecture are. I think the + + + align:start position:0% +cognitive architecture are. I think the +situated learning people have cognates. + + align:start position:0% +situated learning people have cognates. + + + align:start position:0% +situated learning people have cognates. +I think they have things that they + + align:start position:0% +I think they have things that they + + + align:start position:0% +I think they have things that they +believe are central about the brain, how + + align:start position:0% +believe are central about the brain, how + + + align:start position:0% +believe are central about the brain, how +learning works. Um but they would draw a + + align:start position:0% +learning works. Um but they would draw a + + + align:start position:0% +learning works. Um but they would draw a +different model like this is not what + + align:start position:0% +different model like this is not what + + + align:start position:0% +different model like this is not what +they were draw and and but and they're + + align:start position:0% +they were draw and and but and they're + + + align:start position:0% +they were draw and and but and they're +less explicit about it which makes our + + align:start position:0% +less explicit about it which makes our + + + align:start position:0% +less explicit about it which makes our +job a little bit harder but a thing that + + align:start position:0% +job a little bit harder but a thing that + + + align:start position:0% +job a little bit harder but a thing that +you can be thinking about now um is like + + align:start position:0% +you can be thinking about now um is like + + + align:start position:0% +you can be thinking about now um is like +what would be you know what is the what + + align:start position:0% +what would be you know what is the what + + + align:start position:0% +what would be you know what is the what +is the situated learning cognate of this + + align:start position:0% +is the situated learning cognate of this + + + align:start position:0% +is the situated learning cognate of this +like what would be the pieces that they + + align:start position:0% +like what would be the pieces that they + + + align:start position:0% +like what would be the pieces that they +would put in the model that would be + + align:start position:0% +would put in the model that would be + + + align:start position:0% +would put in the model that would be +most important um for their + + align:start position:0% +most important um for their + + + align:start position:0% +most important um for their +developmental learning. We'll play with + + align:start position:0% +developmental learning. We'll play with + + + align:start position:0% +developmental learning. We'll play with +that as we go along a little bit. Okay. + + align:start position:0% +that as we go along a little bit. Okay. + + + align:start position:0% +that as we go along a little bit. Okay. +Um how many of you ever use the logo + + align:start position:0% +Um how many of you ever use the logo + + + align:start position:0% +Um how many of you ever use the logo +programming language? + + align:start position:0% +programming language? + + + align:start position:0% +programming language? +Oh good. More than there. How many of + + align:start position:0% +Oh good. More than there. How many of + + + align:start position:0% +Oh good. More than there. How many of +you use Scratch? Okay, there we got + + align:start position:0% +you use Scratch? Okay, there we got + + + align:start position:0% +you use Scratch? Okay, there we got +everybody. Um, so Scratch is a + + align:start position:0% +everybody. Um, so Scratch is a + + + align:start position:0% +everybody. Um, so Scratch is a +descendant of Logo. Um, Logo is a + + align:start position:0% +descendant of Logo. Um, Logo is a + + + align:start position:0% +descendant of Logo. Um, Logo is a +programming language that was uh + + align:start position:0% +programming language that was uh + + + align:start position:0% +programming language that was uh +developed by Seymour Papert um in the + + align:start position:0% +developed by Seymour Papert um in the + + + align:start position:0% +developed by Seymour Papert um in the +media lab. Uh, one of the first efforts + + align:start position:0% +media lab. Uh, one of the first efforts + + + align:start position:0% +media lab. Uh, one of the first efforts +to bring computer programming to um kids + + align:start position:0% +to bring computer programming to um kids + + + align:start position:0% +to bring computer programming to um kids +in schools when I was in the fourth + + align:start position:0% +in schools when I was in the fourth + + + align:start position:0% +in schools when I was in the fourth +grade at a monastery school in South NIC + + align:start position:0% +grade at a monastery school in South NIC + + + align:start position:0% +grade at a monastery school in South NIC +not far from here. We had a little + + align:start position:0% +not far from here. We had a little + + + align:start position:0% +not far from here. We had a little +computer lab and logo was the language + + align:start position:0% +computer lab and logo was the language + + + align:start position:0% +computer lab and logo was the language +that I learned to do a little bit of + + align:start position:0% +that I learned to do a little bit of + + + align:start position:0% +that I learned to do a little bit of +programming anyway with um you'll see + + align:start position:0% +programming anyway with um you'll see + + + align:start position:0% +programming anyway with um you'll see +that a lot of it um is about shapes and + + align:start position:0% +that a lot of it um is about shapes and + + + align:start position:0% +that a lot of it um is about shapes and +geometry. Um but what I really loved + + align:start position:0% +geometry. Um but what I really loved + + + align:start position:0% +geometry. Um but what I really loved +about it was uh choose your own + + align:start position:0% +about it was uh choose your own + + + align:start position:0% +about it was uh choose your own +adventures. Um so you could essentially + + align:start position:0% +adventures. Um so you could essentially + + + align:start position:0% +adventures. Um so you could essentially +like like write a program or function + + align:start position:0% +like like write a program or function + + + align:start position:0% +like like write a program or function +whatever it is in which uh someone types + + align:start position:0% +whatever it is in which uh someone types + + + align:start position:0% +whatever it is in which uh someone types +a word and that triggers the the display + + align:start position:0% +a word and that triggers the the display + + + align:start position:0% +a word and that triggers the the display +of a set of text. Um, and so it wasn't + + align:start position:0% +of a set of text. Um, and so it wasn't + + + align:start position:0% +of a set of text. Um, and so it wasn't +that hard to make choose your own + + align:start position:0% +that hard to make choose your own + + + align:start position:0% +that hard to make choose your own +adventures, you know, you know, like + + align:start position:0% +adventures, you know, you know, like + + + align:start position:0% +adventures, you know, you know, like +you're you're you're at the front of the + + align:start position:0% +you're you're you're at the front of the + + + align:start position:0% +you're you're you're at the front of the +house. Do you want to walk up to the, + + align:start position:0% +house. Do you want to walk up to the, + + + align:start position:0% +house. Do you want to walk up to the, +you know, type porch if you want to walk + + align:start position:0% +you know, type porch if you want to walk + + + align:start position:0% +you know, type porch if you want to walk +into porch? Um, type, uh, knock if you + + align:start position:0% +into porch? Um, type, uh, knock if you + + + align:start position:0% +into porch? Um, type, uh, knock if you +want to knock on the door. And then + + align:start position:0% +want to knock on the door. And then + + + align:start position:0% +want to knock on the door. And then +knock is a program that releases another + + align:start position:0% +knock is a program that releases another + + + align:start position:0% +knock is a program that releases another +set of text and you can make choose your + + align:start position:0% +set of text and you can make choose your + + + align:start position:0% +set of text and you can make choose your +own adventure that way. How important is + + align:start position:0% +own adventure that way. How important is + + + align:start position:0% +own adventure that way. How important is +that for you to know? I don't know. Here + + align:start position:0% +that for you to know? I don't know. Here + + + align:start position:0% +that for you to know? I don't know. Here +um is a few minutes of Seymour Papert + + align:start position:0% +um is a few minutes of Seymour Papert + + + align:start position:0% +um is a few minutes of Seymour Papert +um who was a student of Jean PG who's + + align:start position:0% +um who was a student of Jean PG who's + + + align:start position:0% +um who was a student of Jean PG who's +another kind of major social + + align:start position:0% +another kind of major social + + + align:start position:0% +another kind of major social +constructivist sort of thinker. Here's + + align:start position:0% +constructivist sort of thinker. Here's + + + align:start position:0% +constructivist sort of thinker. Here's +um what uh logo was supposed to look + + align:start position:0% +um what uh logo was supposed to look + + + align:start position:0% +um what uh logo was supposed to look +like in the classroom in the 1980s about + + align:start position:0% +like in the classroom in the 1980s about + + + align:start position:0% +like in the classroom in the 1980s about +when I was a kid. + + align:start position:0% +when I was a kid. + + + align:start position:0% +when I was a kid. +The idea is quite + + align:start position:0% +The idea is quite + + + align:start position:0% +The idea is quite +simple. Let learn mathematics by + + align:start position:0% +simple. Let learn mathematics by + + + align:start position:0% +simple. Let learn mathematics by +speaking in mathematics about things + + align:start position:0% +speaking in mathematics about things + + + align:start position:0% +speaking in mathematics about things +that really matter to him. So at MIT, + + align:start position:0% +that really matter to him. So at MIT, + + + align:start position:0% +that really matter to him. So at MIT, +we've given computers the power to turn + + align:start position:0% +we've given computers the power to turn + + + align:start position:0% +we've given computers the power to turn +motors, to make sounds, to draw + + align:start position:0% +motors, to make sounds, to draw + + + align:start position:0% +motors, to make sounds, to draw +pictures, and we've found ways of giving + + align:start position:0% +pictures, and we've found ways of giving + + + align:start position:0% +pictures, and we've found ways of giving +children the power to control the + + align:start position:0% +children the power to control the + + + align:start position:0% +children the power to control the +computer. So the child can make the + + align:start position:0% +computer. So the child can make the + + + align:start position:0% +computer. So the child can make the +computer do anything that he can + + align:start position:0% +computer do anything that he can + + + align:start position:0% +computer do anything that he can +describe in a suitable mathematical + + align:start position:0% +describe in a suitable mathematical + + + align:start position:0% +describe in a suitable mathematical +language by typing on a keyboard like + + align:start position:0% +language by typing on a keyboard like + + + align:start position:0% +language by typing on a keyboard like +this. + + align:start position:0% + + + + align:start position:0% + +That's what um P1 sounds like. + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +P2. That's P2 and P3. + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +A computer controlled turtle is made to + + align:start position:0% +A computer controlled turtle is made to + + + align:start position:0% +A computer controlled turtle is made to +draw and dance by programs so simple + + align:start position:0% +draw and dance by programs so simple + + + align:start position:0% +draw and dance by programs so simple +that all children invent them in the + + align:start position:0% +that all children invent them in the + + + align:start position:0% +that all children invent them in the +first days of the course. Thus, the + + align:start position:0% +first days of the course. Thus, the + + + align:start position:0% +first days of the course. Thus, the +child acquires a taste of math power + + align:start position:0% +child acquires a taste of math power + + + align:start position:0% +child acquires a taste of math power +that grows and grows as his projects + + align:start position:0% +that grows and grows as his projects + + + align:start position:0% +that grows and grows as his projects +become more original, more complex, and + + align:start position:0% +become more original, more complex, and + + + align:start position:0% +become more original, more complex, and +more varied. So, you have like the um + + align:start position:0% +more varied. So, you have like the um + + + align:start position:0% +more varied. So, you have like the um +first one, then the second one, then the + + align:start position:0% +first one, then the second one, then the + + + align:start position:0% +first one, then the second one, then the +third one, then the first one again for + + align:start position:0% +third one, then the first one again for + + + align:start position:0% +third one, then the first one again for +the ending. Okay. Now they'll put their + + align:start position:0% +the ending. Okay. Now they'll put their + + + align:start position:0% +the ending. Okay. Now they'll put their +little tunes together to + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +make now. I'm telling it to do it. + + align:start position:0% + + + + align:start position:0% + +I know. + + align:start position:0% +I know. + + + align:start position:0% +I know. +Sometimes I get into bugs like this and + + align:start position:0% +Sometimes I get into bugs like this and + + + align:start position:0% +Sometimes I get into bugs like this and +it'll + + align:start position:0% +it'll + + + align:start position:0% +it'll +um when it was doing it in his mind, the + + align:start position:0% +um when it was doing it in his mind, the + + + align:start position:0% +um when it was doing it in his mind, the +little turtle, it's the little triangle + + align:start position:0% +little turtle, it's the little triangle + + + align:start position:0% +little turtle, it's the little triangle +thing um was on an angle. So it drew the + + align:start position:0% +thing um was on an angle. So it drew the + + + align:start position:0% +thing um was on an angle. So it drew the +picture on on an angle. So now I'll go + + align:start position:0% +picture on on an angle. So now I'll go + + + align:start position:0% +picture on on an angle. So now I'll go +back and have it draw it in its mind + + align:start position:0% +back and have it draw it in its mind + + + align:start position:0% +back and have it draw it in its mind +again while it's in the right position. + + align:start position:0% +again while it's in the right position. + + + align:start position:0% +again while it's in the right position. +And so the child doesn't have to be told + + align:start position:0% +And so the child doesn't have to be told + + + align:start position:0% +And so the child doesn't have to be told +by a teacher whether he's right or + + align:start position:0% +by a teacher whether he's right or + + + align:start position:0% +by a teacher whether he's right or +wrong. He can see for himself whether it + + align:start position:0% +wrong. He can see for himself whether it + + + align:start position:0% +wrong. He can see for himself whether it +works. That's what science and knowledge + + align:start position:0% +works. That's what science and knowledge + + + align:start position:0% +works. That's what science and knowledge +is about. Super procedure is named + + align:start position:0% +is about. Super procedure is named + + + align:start position:0% +is about. Super procedure is named +fancy. And then you have an input which + + align:start position:0% +fancy. And then you have an input which + + + align:start position:0% +fancy. And then you have an input which +means you can vary the size. I'm going + + align:start position:0% +means you can vary the size. I'm going + + + align:start position:0% +means you can vary the size. I'm going +to make it + + align:start position:0% + + + + align:start position:0% + +100. Right now it's doing a procedure + + align:start position:0% +100. Right now it's doing a procedure + + + align:start position:0% +100. Right now it's doing a procedure +called + + align:start position:0% +called + + + align:start position:0% +called +top. And each one of those little fins + + align:start position:0% +top. And each one of those little fins + + + align:start position:0% +top. And each one of those little fins +is called fin. And that's another sub + + align:start position:0% +is called fin. And that's another sub + + + align:start position:0% +is called fin. And that's another sub +procedure in top. Now it's doing inside. + + align:start position:0% +procedure in top. Now it's doing inside. + + + align:start position:0% +procedure in top. Now it's doing inside. +They are identifiable techniques for + + align:start position:0% +They are identifiable techniques for + + + align:start position:0% +They are identifiable techniques for +working on a problem. One of these is + + align:start position:0% +working on a problem. One of these is + + + align:start position:0% +working on a problem. One of these is +known by these children as writing + + align:start position:0% +known by these children as writing + + + align:start position:0% +known by these children as writing +procedures as subrocedures. Inside and + + align:start position:0% +procedures as subrocedures. Inside and + + + align:start position:0% +procedures as subrocedures. Inside and +top are the two main + + align:start position:0% +top are the two main + + + align:start position:0% +top are the two main +subprocedures and the other one the tail + + align:start position:0% +subprocedures and the other one the tail + + + align:start position:0% +subprocedures and the other one the tail +is made out of odds and ends. just put + + align:start position:0% +is made out of odds and ends. just put + + + align:start position:0% +is made out of odds and ends. just put +just put together the techniques really + + align:start position:0% +just put together the techniques really + + + align:start position:0% +just put together the techniques really +well known. Subdivide the problem. Split + + align:start position:0% +well known. Subdivide the problem. Split + + + align:start position:0% +well known. Subdivide the problem. Split +the + + align:start position:0% +the + + + align:start position:0% +the +difficulties. Make a procedure out of + + align:start position:0% +difficulties. Make a procedure out of + + + align:start position:0% +difficulties. Make a procedure out of +subprocedures. Make a whole I'll just + + align:start position:0% +subprocedures. Make a whole I'll just + + + align:start position:0% +subprocedures. Make a whole I'll just +tell you one second about this little + + align:start position:0% +tell you one second about this little + + + align:start position:0% +tell you one second about this little +robot which again is like iconic my + + align:start position:0% +robot which again is like iconic my + + + align:start position:0% +robot which again is like iconic my +childhood. I I had a commercialized + + align:start position:0% +childhood. I I had a commercialized + + + align:start position:0% +childhood. I I had a commercialized +version of this. Um but it it t it it + + align:start position:0% +version of this. Um but it it t it it + + + align:start position:0% +version of this. Um but it it t it it +takes the same commands and uses the + + align:start position:0% +takes the same commands and uses the + + + align:start position:0% +takes the same commands and uses the +same language as the turtle that's on + + align:start position:0% +same language as the turtle that's on + + + align:start position:0% +same language as the turtle that's on +the screen. So you can tell it like + + align:start position:0% +the screen. So you can tell it like + + + align:start position:0% +the screen. So you can tell it like +forward 10 and there's some equivalent + + align:start position:0% +forward 10 and there's some equivalent + + + align:start position:0% +forward 10 and there's some equivalent +to forward 10 that also shows up on the + + align:start position:0% +to forward 10 that also shows up on the + + + align:start position:0% +to forward 10 that also shows up on the +screen. It has a pen that's mounted in + + align:start position:0% +screen. It has a pen that's mounted in + + + align:start position:0% +screen. It has a pen that's mounted in +it that's controlled with pen up and pen + + align:start position:0% +it that's controlled with pen up and pen + + + align:start position:0% +it that's controlled with pen up and pen +down. Um, so you can like make varying + + align:start position:0% +down. Um, so you can like make varying + + + align:start position:0% +down. Um, so you can like make varying +kinds of shapes using that. And then if + + align:start position:0% +kinds of shapes using that. And then if + + + align:start position:0% +kinds of shapes using that. And then if +you see the cable that the person is + + align:start position:0% +you see the cable that the person is + + + align:start position:0% +you see the cable that the person is +walking around with, that was a serial + + align:start position:0% +walking around with, that was a serial + + + align:start position:0% +walking around with, that was a serial +cable which is the primary thing we used + + align:start position:0% +cable which is the primary thing we used + + + align:start position:0% +cable which is the primary thing we used +to use to connect computers to + + align:start position:0% +to use to connect computers to + + + align:start position:0% +to use to connect computers to +peripherals. So that like before + + align:start position:0% +peripherals. So that like before + + + align:start position:0% +peripherals. So that like before +wireless or before you know USB or other + + align:start position:0% +wireless or before you know USB or other + + + align:start position:0% +wireless or before you know USB or other +things like that that was the cable that + + align:start position:0% +things like that that was the cable that + + + align:start position:0% +things like that that was the cable that +they were using to move things around + + align:start position:0% +they were using to move things around + + + align:start position:0% +they were using to move things around +procedure out of sub procedures, make a + + align:start position:0% +procedure out of sub procedures, make a + + + align:start position:0% +procedure out of sub procedures, make a +hold out of parts. Understand each + + align:start position:0% +hold out of parts. Understand each + + + align:start position:0% +hold out of parts. Understand each +separately. Everybody knows that, but + + align:start position:0% +separately. Everybody knows that, but + + + align:start position:0% +separately. Everybody knows that, but +they don't do it. Now, it's moving + + align:start position:0% +they don't do it. Now, it's moving + + + align:start position:0% +they don't do it. Now, it's moving +across the screen the way I um told you + + align:start position:0% +across the screen the way I um told you + + + align:start position:0% +across the screen the way I um told you +it did it before, but this time, this is + + align:start position:0% +it did it before, but this time, this is + + + align:start position:0% +it did it before, but this time, this is +like the way I taught myself to get it + + align:start position:0% +like the way I taught myself to get it + + + align:start position:0% +like the way I taught myself to get it +across the screen. It's the first time I + + align:start position:0% +across the screen. It's the first time I + + + align:start position:0% +across the screen. It's the first time I +had done it. And so, the way I have the + + align:start position:0% +had done it. And so, the way I have the + + + align:start position:0% +had done it. And so, the way I have the +little one to go is every time it moves + + align:start position:0% +little one to go is every time it moves + + + align:start position:0% +little one to go is every time it moves +up a little, it subtracts a number, a + + align:start position:0% +up a little, it subtracts a number, a + + + align:start position:0% +up a little, it subtracts a number, a +little bit of a number, and then until + + align:start position:0% +little bit of a number, and then until + + + align:start position:0% +little bit of a number, and then until +it it's a small number. And when it's a + + align:start position:0% +it it's a small number. And when it's a + + + align:start position:0% +it it's a small number. And when it's a +certain number, I tell it that it should + + align:start position:0% +certain number, I tell it that it should + + + align:start position:0% +certain number, I tell it that it should +stop. + + align:start position:0% +stop. + + + align:start position:0% +stop. +Martha's getting mathematical knowledge + + align:start position:0% +Martha's getting mathematical knowledge + + + align:start position:0% +Martha's getting mathematical knowledge +in a meaningful context for use. Now, + + align:start position:0% +in a meaningful context for use. Now, + + + align:start position:0% +in a meaningful context for use. Now, +it just told me I can't move off the + + align:start position:0% +it just told me I can't move off the + + + align:start position:0% +it just told me I can't move off the +screen. When I was at school, they told + + align:start position:0% +screen. When I was at school, they told + + + align:start position:0% +screen. When I was at school, they told +me to learn long division because I + + align:start position:0% +me to learn long division because I + + + align:start position:0% +me to learn long division because I +would need it when I grew up. And I + + align:start position:0% +would need it when I grew up. And I + + + align:start position:0% +would need it when I grew up. And I +think I knew it was a + + align:start position:0% +think I knew it was a + + + align:start position:0% +think I knew it was a +lie. It was to make me despise the + + align:start position:0% +lie. It was to make me despise the + + + align:start position:0% +lie. It was to make me despise the +teachers a little more. Now it's drawing + + align:start position:0% +teachers a little more. Now it's drawing + + + align:start position:0% +teachers a little more. Now it's drawing +the + + align:start position:0% +the + + + align:start position:0% +the +gill a + + align:start position:0% +gill a + + + align:start position:0% +gill a +subrocedure. Now the bottom of the fish + + align:start position:0% +subrocedure. Now the bottom of the fish + + + align:start position:0% +subrocedure. Now the bottom of the fish +Steven is using the ideas of angle of + + align:start position:0% +Steven is using the ideas of angle of + + + align:start position:0% +Steven is using the ideas of angle of +subrocedure of arc and of circle in a + + align:start position:0% +subrocedure of arc and of circle in a + + + align:start position:0% +subrocedure of arc and of circle in a +confident purposeful way. The tail the + + align:start position:0% +confident purposeful way. The tail the + + + align:start position:0% +confident purposeful way. The tail the +triangle part is made out of a procedure + + align:start position:0% +triangle part is made out of a procedure + + + align:start position:0% +triangle part is made out of a procedure +called try one. First you got to do + + align:start position:0% +called try one. First you got to do + + + align:start position:0% +called try one. First you got to do +right 60, then forward 50, back 50, left + + align:start position:0% +right 60, then forward 50, back 50, left + + + align:start position:0% +right 60, then forward 50, back 50, left +60, forward 50, back 50, left 60, + + align:start position:0% +60, forward 50, back 50, left 60, + + + align:start position:0% +60, forward 50, back 50, left 60, +forward 50, back 50, and so on. + + align:start position:0% + + + + align:start position:0% + +Now it's doing a + + align:start position:0% +Now it's doing a + + + align:start position:0% +Now it's doing a +firm. That's a radius of 300 and a um + + align:start position:0% +firm. That's a radius of 300 and a um + + + align:start position:0% +firm. That's a radius of 300 and a um +arc of 90. I made a big radius. And then + + align:start position:0% +arc of 90. I made a big radius. And then + + + align:start position:0% +arc of 90. I made a big radius. And then +I went sector left which will go right + + align:start position:0% +I went sector left which will go right + + + align:start position:0% +I went sector left which will go right +over it and bring it back. Then I made a + + align:start position:0% +over it and bring it back. Then I made a + + + align:start position:0% +over it and bring it back. Then I made a +smaller radius of the same arc and then + + align:start position:0% +smaller radius of the same arc and then + + + align:start position:0% +smaller radius of the same arc and then +it would do that again. Then it's even + + align:start position:0% +it would do that again. Then it's even + + + align:start position:0% +it would do that again. Then it's even +smaller one. It will do that again. And + + align:start position:0% +smaller one. It will do that again. And + + + align:start position:0% +smaller one. It will do that again. And +that's how I got the + + align:start position:0% +that's how I got the + + + align:start position:0% +that's how I got the +fern. There we are. There's the finished + + align:start position:0% +fern. There we are. There's the finished + + + align:start position:0% +fern. There we are. There's the finished +picture. + + align:start position:0% +picture. + + + align:start position:0% +picture. +I made a big song and I used that for + + align:start position:0% +I made a big song and I used that for + + + align:start position:0% +I made a big song and I used that for +part of it and then I made an + + align:start position:0% +part of it and then I made an + + + align:start position:0% +part of it and then I made an +accompanying with it with the drum and + + align:start position:0% +accompanying with it with the drum and + + + align:start position:0% +accompanying with it with the drum and +that's um + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +The kids told me that's a spiral. I + + align:start position:0% +The kids told me that's a spiral. I + + + align:start position:0% +The kids told me that's a spiral. I +think there was a new mathematical word + + align:start position:0% +think there was a new mathematical word + + + align:start position:0% +think there was a new mathematical word +that was born there that's going to + + align:start position:0% +that was born there that's going to + + + align:start position:0% +that was born there that's going to +stick. I'd call that real discovery. + + align:start position:0% +stick. I'd call that real discovery. + + + align:start position:0% +stick. I'd call that real discovery. +[Music] + + align:start position:0% + + + + align:start position:0% + +Good. Don't spend time with this. Um, + + align:start position:0% +Good. Don't spend time with this. Um, + + + align:start position:0% +Good. Don't spend time with this. Um, +turn the people next to you. Talk to + + align:start position:0% +turn the people next to you. Talk to + + + align:start position:0% +turn the people next to you. Talk to +them a little bit. What are what are the + + align:start position:0% +them a little bit. What are what are the + + + align:start position:0% +them a little bit. What are what are the +things that you saw in there that coher + + align:start position:0% +things that you saw in there that coher + + + align:start position:0% +things that you saw in there that coher +with ideas that you read about from + + align:start position:0% +with ideas that you read about from + + + align:start position:0% +with ideas that you read about from +other communities of situated learning? + + align:start position:0% +other communities of situated learning? + + + align:start position:0% +other communities of situated learning? +What are some things that you saw in + + align:start position:0% +What are some things that you saw in + + + align:start position:0% +What are some things that you saw in +there that cohered with cognitive load + + align:start position:0% +there that cohered with cognitive load + + + align:start position:0% +there that cohered with cognitive load +theory? Do you see sort of evidence of + + align:start position:0% +theory? Do you see sort of evidence of + + + align:start position:0% +theory? Do you see sort of evidence of +direct instruction that was in there + + align:start position:0% +direct instruction that was in there + + + align:start position:0% +direct instruction that was in there +anywhere? Um and then what kind of + + align:start position:0% +anywhere? Um and then what kind of + + + align:start position:0% +anywhere? Um and then what kind of +learning environments have you been like + + align:start position:0% +learning environments have you been like + + + align:start position:0% +learning environments have you been like +um where you learned in this kind of way + + align:start position:0% +um where you learned in this kind of way + + + align:start position:0% +um where you learned in this kind of way +that was pleasurable? And have people + + align:start position:0% +that was pleasurable? And have people + + + align:start position:0% +that was pleasurable? And have people +been in learning environments where + + align:start position:0% +been in learning environments where + + + align:start position:0% +been in learning environments where +you've sort of learned in this way that + + align:start position:0% +you've sort of learned in this way that + + + align:start position:0% +you've sort of learned in this way that +you found very unpleasurable and + + align:start position:0% +you found very unpleasurable and + + + align:start position:0% +you found very unpleasurable and +unlikable? Then discuss that for a + + align:start position:0% +unlikable? Then discuss that for a + + + align:start position:0% +unlikable? Then discuss that for a +couple minutes. Ready? Go. + + align:start position:0% +couple minutes. Ready? Go. + + + align:start position:0% +couple minutes. Ready? Go. +Every good. What are what are what are + + align:start position:0% +Every good. What are what are what are + + + align:start position:0% +Every good. What are what are what are +some connections that people made? What + + align:start position:0% +some connections that people made? What + + + align:start position:0% +some connections that people made? What +are some things that uh where you saw + + align:start position:0% +are some things that uh where you saw + + + align:start position:0% +are some things that uh where you saw +examples of uh situated learning or + + align:start position:0% +examples of uh situated learning or + + + align:start position:0% +examples of uh situated learning or +cognitive load theory or things that + + align:start position:0% +cognitive load theory or things that + + + align:start position:0% +cognitive load theory or things that +seem pleasurable or or frustrating? What + + align:start position:0% +seem pleasurable or or frustrating? What + + + align:start position:0% +seem pleasurable or or frustrating? What +did you talk about in your groups? We + + align:start position:0% +did you talk about in your groups? We + + + align:start position:0% +did you talk about in your groups? We +were talking about learning like + + align:start position:0% +were talking about learning like + + + align:start position:0% +were talking about learning like +programming in general or it seems like + + align:start position:0% +programming in general or it seems like + + + align:start position:0% +programming in general or it seems like +you always need some base level of + + align:start position:0% +you always need some base level of + + + align:start position:0% +you always need some base level of +whether it's the instructions or knowing + + align:start position:0% +whether it's the instructions or knowing + + + align:start position:0% +whether it's the instructions or knowing +whatever commands there are in logo and + + align:start position:0% +whatever commands there are in logo and + + + align:start position:0% +whatever commands there are in logo and +that most likely comes from more of an + + align:start position:0% +that most likely comes from more of an + + + align:start position:0% +that most likely comes from more of an +instructional place but then you can get + + align:start position:0% +instructional place but then you can get + + + align:start position:0% +instructional place but then you can get +into these situations like we saw in the + + align:start position:0% +into these situations like we saw in the + + + align:start position:0% +into these situations like we saw in the +video where it becomes open world but it + + align:start position:0% +video where it becomes open world but it + + + align:start position:0% +video where it becomes open world but it +still seems like you need some base + + align:start position:0% +still seems like you need some base + + + align:start position:0% +still seems like you need some base +level where CLT needs to come in. All + + align:start position:0% +level where CLT needs to come in. All + + + align:start position:0% +level where CLT needs to come in. All +right. Yeah. Or or some kind of direct + + align:start position:0% +right. Yeah. Or or some kind of direct + + + align:start position:0% +right. Yeah. Or or some kind of direct +instruction. Where where did where what + + align:start position:0% +instruction. Where where did where what + + + align:start position:0% +instruction. Where where did where what +what evidence of direct instruction did + + align:start position:0% +what evidence of direct instruction did + + + align:start position:0% +what evidence of direct instruction did +people um did people see? Like where + + align:start position:0% +people um did people see? Like where + + + align:start position:0% +people um did people see? Like where +were you like h that kid didn't figure + + align:start position:0% +were you like h that kid didn't figure + + + align:start position:0% +were you like h that kid didn't figure +that out on their own? I mean just the + + align:start position:0% +that out on their own? I mean just the + + + align:start position:0% +that out on their own? I mean just the +terminology they figured out like + + align:start position:0% +terminology they figured out like + + + align:start position:0% +terminology they figured out like +procedure subrocedure all of these + + align:start position:0% +procedure subrocedure all of these + + + align:start position:0% +procedure subrocedure all of these +things are a kid a kid wouldn't just + + align:start position:0% +things are a kid a kid wouldn't just + + + align:start position:0% +things are a kid a kid wouldn't just +figure these out. Yeah. Yeah. It doesn't + + align:start position:0% +figure these out. Yeah. Yeah. It doesn't + + + align:start position:0% +figure these out. Yeah. Yeah. It doesn't +seem like Steven came up with the term + + align:start position:0% +seem like Steven came up with the term + + + align:start position:0% +seem like Steven came up with the term +procedure and subrocedure. Like pretty + + align:start position:0% +procedure and subrocedure. Like pretty + + + align:start position:0% +procedure and subrocedure. Like pretty +sure somebody taught him you know sat + + align:start position:0% +sure somebody taught him you know sat + + + align:start position:0% +sure somebody taught him you know sat +down and said this is you know here are + + align:start position:0% +down and said this is you know here are + + + align:start position:0% +down and said this is you know here are +a couple of useful definitions that will + + align:start position:0% +a couple of useful definitions that will + + + align:start position:0% +a couple of useful definitions that will +allow us communicate with us more + + align:start position:0% +allow us communicate with us more + + + align:start position:0% +allow us communicate with us more +clearly. Um also we were talking about + + align:start position:0% +clearly. Um also we were talking about + + + align:start position:0% +clearly. Um also we were talking about +like when the two girls were talking to + + align:start position:0% +like when the two girls were talking to + + + align:start position:0% +like when the two girls were talking to +each other it was like one at the + + align:start position:0% +each other it was like one at the + + + align:start position:0% +each other it was like one at the +beginning was like instruct instructing + + align:start position:0% +beginning was like instruct instructing + + + align:start position:0% +beginning was like instruct instructing +the other. Yeah. + + align:start position:0% +the other. Yeah. + + + align:start position:0% +the other. Yeah. +So, I guess that's kind of like Oh, very + + align:start position:0% +So, I guess that's kind of like Oh, very + + + align:start position:0% +So, I guess that's kind of like Oh, very +direct instruction. Yeah. Instruction + + align:start position:0% +direct instruction. Yeah. Instruction + + + align:start position:0% +direct instruction. Yeah. Instruction +within like a situated learning + + align:start position:0% +within like a situated learning + + + align:start position:0% +within like a situated learning +environment. Yeah. Yeah. I mean, it's + + align:start position:0% +environment. Yeah. Yeah. I mean, it's + + + align:start position:0% +environment. Yeah. Yeah. I mean, it's +it's Yeah. Yeah. It's a it's a kind of + + align:start position:0% +it's Yeah. Yeah. It's a it's a kind of + + + align:start position:0% +it's Yeah. Yeah. It's a it's a kind of +worked example like, oh, I'm going to + + align:start position:0% +worked example like, oh, I'm going to + + + align:start position:0% +worked example like, oh, I'm going to +show you how I you know, I made a thing + + align:start position:0% +show you how I you know, I made a thing + + + align:start position:0% +show you how I you know, I made a thing +like I'm going to, you know, we're going + + align:start position:0% +like I'm going to, you know, we're going + + + align:start position:0% +like I'm going to, you know, we're going +to make this thing together right now by + + align:start position:0% +to make this thing together right now by + + + align:start position:0% +to make this thing together right now by +first of all, play each of the pieces. + + align:start position:0% +first of all, play each of the pieces. + + + align:start position:0% +first of all, play each of the pieces. +Now, we're going to play all the pieces + + align:start position:0% +Now, we're going to play all the pieces + + + align:start position:0% +Now, we're going to play all the pieces +together. I've already learned how to do + + align:start position:0% +together. I've already learned how to do + + + align:start position:0% +together. I've already learned how to do +that. you know what makes it a kind of + + align:start position:0% +that. you know what makes it a kind of + + + align:start position:0% +that. you know what makes it a kind of +peer learning uh uh situated learning + + align:start position:0% +peer learning uh uh situated learning + + + align:start position:0% +peer learning uh uh situated learning +kind of thing is it's one young person + + align:start position:0% +kind of thing is it's one young person + + + align:start position:0% +kind of thing is it's one young person +teaching it to another person but does + + align:start position:0% +teaching it to another person but does + + + align:start position:0% +teaching it to another person but does +seem to be you know direct instruction + + align:start position:0% +seem to be you know direct instruction + + + align:start position:0% +seem to be you know direct instruction +for sure. Um that kind of led us into a + + align:start position:0% +for sure. Um that kind of led us into a + + + align:start position:0% +for sure. Um that kind of led us into a +conversation about how like within + + align:start position:0% +conversation about how like within + + + align:start position:0% +conversation about how like within +situated learning like that there's like + + align:start position:0% +situated learning like that there's like + + + align:start position:0% +situated learning like that there's like +kind of two ways that it can be seen as + + align:start position:0% +kind of two ways that it can be seen as + + + align:start position:0% +kind of two ways that it can be seen as +like you have someone who's like an + + align:start position:0% +like you have someone who's like an + + + align:start position:0% +like you have someone who's like an +old-timer like the the other girl like + + align:start position:0% +old-timer like the the other girl like + + + align:start position:0% +old-timer like the the other girl like +explaining to the other the like the + + align:start position:0% +explaining to the other the like the + + + align:start position:0% +explaining to the other the like the +other girl about um the situation that + + align:start position:0% +other girl about um the situation that + + + align:start position:0% +other girl about um the situation that +they were working with. But then there's + + align:start position:0% +they were working with. But then there's + + + align:start position:0% +they were working with. But then there's +also the instances when it was just like + + align:start position:0% +also the instances when it was just like + + + align:start position:0% +also the instances when it was just like +the student and the computer and that + + align:start position:0% +the student and the computer and that + + + align:start position:0% +the student and the computer and that +like you kind of lost that like social + + align:start position:0% +like you kind of lost that like social + + + align:start position:0% +like you kind of lost that like social +aspect that you have of like learning + + align:start position:0% +aspect that you have of like learning + + + align:start position:0% +aspect that you have of like learning +from another person. Um and then we like + + align:start position:0% +from another person. Um and then we like + + + align:start position:0% +from another person. Um and then we like +went into like an interesting + + align:start position:0% +went into like an interesting + + + align:start position:0% +went into like an interesting +conversation about whether like maybe + + align:start position:0% +conversation about whether like maybe + + + align:start position:0% +conversation about whether like maybe +the student was like having a social + + align:start position:0% +the student was like having a social + + + align:start position:0% +the student was like having a social +interaction from themsel and like + + align:start position:0% +interaction from themsel and like + + + align:start position:0% +interaction from themsel and like +learning with the computer as a tool or + + align:start position:0% +learning with the computer as a tool or + + + align:start position:0% +learning with the computer as a tool or +maybe they were having a social + + align:start position:0% +maybe they were having a social + + + align:start position:0% +maybe they were having a social +interaction with the computer itself and + + align:start position:0% +interaction with the computer itself and + + + align:start position:0% +interaction with the computer itself and +like they were learning from the + + align:start position:0% +like they were learning from the + + + align:start position:0% +like they were learning from the +computer and the computer was like + + align:start position:0% +computer and the computer was like + + + align:start position:0% +computer and the computer was like +learning what like they really wanted + + align:start position:0% +learning what like they really wanted + + + align:start position:0% +learning what like they really wanted +the outcome to be. So yeah. Yeah, good. + + align:start position:0% +the outcome to be. So yeah. Yeah, good. + + + align:start position:0% +the outcome to be. So yeah. Yeah, good. +Yeah, that's definitely something we'll + + align:start position:0% +Yeah, that's definitely something we'll + + + align:start position:0% +Yeah, that's definitely something we'll +think about more as we go along. Like + + align:start position:0% +think about more as we go along. Like + + + align:start position:0% +think about more as we go along. Like +what kind of agent is the machine? What + + align:start position:0% +what kind of agent is the machine? What + + + align:start position:0% +what kind of agent is the machine? What +kind of relationship do we have uh to + + align:start position:0% +kind of relationship do we have uh to + + + align:start position:0% +kind of relationship do we have uh to +the machines? How does the machine + + align:start position:0% +the machines? How does the machine + + + align:start position:0% +the machines? How does the machine +motivate? How does the machine explain? + + align:start position:0% +motivate? How does the machine explain? + + + align:start position:0% +motivate? How does the machine explain? +The thing that seems pretty rad here + + align:start position:0% +The thing that seems pretty rad here + + + align:start position:0% +The thing that seems pretty rad here +that that seem more pepper is the + + align:start position:0% +that that seem more pepper is the + + + align:start position:0% +that that seem more pepper is the +machine gives some great feedback. + + align:start position:0% +machine gives some great feedback. + + + align:start position:0% +machine gives some great feedback. +Although lots of other things do. Um uh + + align:start position:0% +Although lots of other things do. Um uh + + + align:start position:0% +Although lots of other things do. Um uh +hand drills give great feedback. You + + align:start position:0% +hand drills give great feedback. You + + + align:start position:0% +hand drills give great feedback. You +know, when you like go through the wall, + + align:start position:0% +know, when you like go through the wall, + + + align:start position:0% +know, when you like go through the wall, +you know it. And when you like, you + + align:start position:0% +you know it. And when you like, you + + + align:start position:0% +you know it. And when you like, you +know, hit something metal or something + + align:start position:0% +know, hit something metal or something + + + align:start position:0% +know, hit something metal or something +like that, you know it and you get that + + align:start position:0% +like that, you know it and you get that + + + align:start position:0% +like that, you know it and you get that +kind of instant feedback. Um there are + + align:start position:0% +kind of instant feedback. Um there are + + + align:start position:0% +kind of instant feedback. Um there are +other things that we teach people where + + align:start position:0% +other things that we teach people where + + + align:start position:0% +other things that we teach people where +it's just hard to imagine where that + + align:start position:0% +it's just hard to imagine where that + + + align:start position:0% +it's just hard to imagine where that +instant feedback might come from. Um + + align:start position:0% +instant feedback might come from. Um + + + align:start position:0% +instant feedback might come from. Um +writing is often that way especially + + align:start position:0% +writing is often that way especially + + + align:start position:0% +writing is often that way especially +like writing other people. There's + + align:start position:0% +like writing other people. There's + + + align:start position:0% +like writing other people. There's +nothing that a sort of screen right we + + align:start position:0% +nothing that a sort of screen right we + + + align:start position:0% +nothing that a sort of screen right we +haven't built things very well where a + + align:start position:0% +haven't built things very well where a + + + align:start position:0% +haven't built things very well where a +machine can tell you like oh that's a + + align:start position:0% +machine can tell you like oh that's a + + + align:start position:0% +machine can tell you like oh that's a +compelling way of expressing that idea + + align:start position:0% +compelling way of expressing that idea + + + align:start position:0% +compelling way of expressing that idea +um in the same way that I can be like oh + + align:start position:0% +um in the same way that I can be like oh + + + align:start position:0% +um in the same way that I can be like oh +my swan is on its side. Um so sort of + + align:start position:0% +my swan is on its side. Um so sort of + + + align:start position:0% +my swan is on its side. Um so sort of +different you know different + + align:start position:0% +different you know different + + + align:start position:0% +different you know different +technologies or and different in you + + align:start position:0% +technologies or and different in you + + + align:start position:0% +technologies or and different in you +know different things that we study have + + align:start position:0% +know different things that we study have + + + align:start position:0% +know different things that we study have +have different capacity to give us + + align:start position:0% +have different capacity to give us + + + align:start position:0% +have different capacity to give us +immediate feedback about what we're + + align:start position:0% +immediate feedback about what we're + + + align:start position:0% +immediate feedback about what we're +doing. Um good other has anybody ever + + align:start position:0% +doing. Um good other has anybody ever + + + align:start position:0% +doing. Um good other has anybody ever +been in an environment like this where + + align:start position:0% +been in an environment like this where + + + align:start position:0% +been in an environment like this where +you're like oh my gosh this is the worst + + align:start position:0% +you're like oh my gosh this is the worst + + + align:start position:0% +you're like oh my gosh this is the worst +do students have experience in this kind + + align:start position:0% +do students have experience in this kind + + + align:start position:0% +do students have experience in this kind +of like open-ended learning where you're + + align:start position:0% +of like open-ended learning where you're + + + align:start position:0% +of like open-ended learning where you're +like this is terrible. Yeah, I remember + + align:start position:0% +like this is terrible. Yeah, I remember + + + align:start position:0% +like this is terrible. Yeah, I remember +this like one or I guess the some more + + align:start position:0% +this like one or I guess the some more + + + align:start position:0% +this like one or I guess the some more +recent MIT experience where basically + + align:start position:0% +recent MIT experience where basically + + + align:start position:0% +recent MIT experience where basically +one of the classes like final project + + align:start position:0% +one of the classes like final project + + + align:start position:0% +one of the classes like final project +was very like open-ended and they were + + align:start position:0% +was very like open-ended and they were + + + align:start position:0% +was very like open-ended and they were +like, "Oh, like just like design this + + align:start position:0% +like, "Oh, like just like design this + + + align:start position:0% +like, "Oh, like just like design this +game." And I was like, "Wow, like it + + align:start position:0% +game." And I was like, "Wow, like it + + + align:start position:0% +game." And I was like, "Wow, like it +would be nice to get some kind of Yeah, + + align:start position:0% +would be nice to get some kind of Yeah, + + + align:start position:0% +would be nice to get some kind of Yeah, +will you please show me how to design + + align:start position:0% +will you please show me how to design + + + align:start position:0% +will you please show me how to design +this game? Like I don't like someone has + + align:start position:0% +this game? Like I don't like someone has + + + align:start position:0% +this game? Like I don't like someone has +figured this out before. Like I don't I + + align:start position:0% +figured this out before. Like I don't I + + + align:start position:0% +figured this out before. Like I don't I +don't want to explore this space + + align:start position:0% +don't want to explore this space + + + align:start position:0% +don't want to explore this space +forever." I've definitely have people + + align:start position:0% +forever." I've definitely have people + + + align:start position:0% +forever." I've definitely have people +who who have taken this class and they + + align:start position:0% +who who have taken this class and they + + + align:start position:0% +who who have taken this class and they +watch this video and they're like, "Give + + align:start position:0% +watch this video and they're like, "Give + + + align:start position:0% +watch this video and they're like, "Give +me a break." Like just show me how to + + align:start position:0% +me a break." Like just show me how to + + + align:start position:0% +me a break." Like just show me how to +use the turtle. them. Um I would say in + + align:start position:0% +use the turtle. them. Um I would say in + + + align:start position:0% +use the turtle. them. Um I would say in +high school um a lot of the AP computer + + align:start position:0% +high school um a lot of the AP computer + + + align:start position:0% +high school um a lot of the AP computer +science classes are like very into like + + align:start position:0% +science classes are like very into like + + + align:start position:0% +science classes are like very into like +this kind of situated learning. But then + + align:start position:0% +this kind of situated learning. But then + + + align:start position:0% +this kind of situated learning. But then +if you have certain classrooms where + + align:start position:0% +if you have certain classrooms where + + + align:start position:0% +if you have certain classrooms where +like in my instance it was like just + + align:start position:0% +like in my instance it was like just + + + align:start position:0% +like in my instance it was like just +overloaded with people who just need an + + align:start position:0% +overloaded with people who just need an + + + align:start position:0% +overloaded with people who just need an +elective and they were like you have to + + align:start position:0% +elective and they were like you have to + + + align:start position:0% +elective and they were like you have to +take this class then it becomes that um + + align:start position:0% +take this class then it becomes that um + + + align:start position:0% +take this class then it becomes that um +like peer-to-peer interaction becomes an + + align:start position:0% +like peer-to-peer interaction becomes an + + + align:start position:0% +like peer-to-peer interaction becomes an +issue where it's like okay you have + + align:start position:0% +issue where it's like okay you have + + + align:start position:0% +issue where it's like okay you have +three people who are trying to teach + + align:start position:0% +three people who are trying to teach + + + align:start position:0% +three people who are trying to teach +like 30 other people how to do a + + align:start position:0% +like 30 other people how to do a + + + align:start position:0% +like 30 other people how to do a +specific thing because you're in the + + align:start position:0% +specific thing because you're in the + + + align:start position:0% +specific thing because you're in the +same like group and they have to pass + + align:start position:0% +same like group and they have to pass + + + align:start position:0% +same like group and they have to pass +and they don't really care anyway. Good. + + align:start position:0% +and they don't really care anyway. Good. + + + align:start position:0% +and they don't really care anyway. Good. +people have different motivations or I + + align:start position:0% +people have different motivations or I + + + align:start position:0% +people have different motivations or I +mean a huge problem that computer + + align:start position:0% +mean a huge problem that computer + + + align:start position:0% +mean a huge problem that computer +science education has is that people + + align:start position:0% +science education has is that people + + + align:start position:0% +science education has is that people +unlike other subjects people come to it + + align:start position:0% +unlike other subjects people come to it + + + align:start position:0% +unlike other subjects people come to it +with very different levels of background + + align:start position:0% +with very different levels of background + + + align:start position:0% +with very different levels of background +experience. Um so like none of you + + align:start position:0% +experience. Um so like none of you + + + align:start position:0% +experience. Um so like none of you +probably ever took a geology class where + + align:start position:0% +probably ever took a geology class where + + + align:start position:0% +probably ever took a geology class where +like a third of the kids were like man I + + align:start position:0% +like a third of the kids were like man I + + + align:start position:0% +like a third of the kids were like man I +just love geology like I do I do geology + + align:start position:0% +just love geology like I do I do geology + + + align:start position:0% +just love geology like I do I do geology +all the time in my spare time. I'm way + + align:start position:0% +all the time in my spare time. I'm way + + + align:start position:0% +all the time in my spare time. I'm way +ahead of you guys. But that is + + align:start position:0% +ahead of you guys. But that is + + + align:start position:0% +ahead of you guys. But that is +essentially what just about every + + align:start position:0% +essentially what just about every + + + align:start position:0% +essentially what just about every +computer science class we teach is like + + align:start position:0% +computer science class we teach is like + + + align:start position:0% +computer science class we teach is like +where a chunk of people are like way + + align:start position:0% +where a chunk of people are like way + + + align:start position:0% +where a chunk of people are like way +into it know a bunch more already. Um, + + align:start position:0% +into it know a bunch more already. Um, + + + align:start position:0% +into it know a bunch more already. Um, +and in fact, those open-ended + + align:start position:0% +and in fact, those open-ended + + + align:start position:0% +and in fact, those open-ended +environments can be can be really great + + align:start position:0% +environments can be can be really great + + + align:start position:0% +environments can be can be really great +for those folks who have that extra + + align:start position:0% +for those folks who have that extra + + + align:start position:0% +for those folks who have that extra +expertise, and they can be a real bummer + + align:start position:0% +expertise, and they can be a real bummer + + + align:start position:0% +expertise, and they can be a real bummer +for people who like can't jump in as + + align:start position:0% +for people who like can't jump in as + + + align:start position:0% +for people who like can't jump in as +naturally. Harmon, what was you going to + + align:start position:0% +naturally. Harmon, what was you going to + + + align:start position:0% +naturally. Harmon, what was you going to +say? Uh, I think what this made me think + + align:start position:0% +say? Uh, I think what this made me think + + + align:start position:0% +say? Uh, I think what this made me think +of is how CLT and situated learning + + align:start position:0% +of is how CLT and situated learning + + + align:start position:0% +of is how CLT and situated learning +cannot be really separated from each + + align:start position:0% +cannot be really separated from each + + + align:start position:0% +cannot be really separated from each +other. Sometimes you need CLT to give + + align:start position:0% +other. Sometimes you need CLT to give + + + align:start position:0% +other. Sometimes you need CLT to give +framework for students and then from + + align:start position:0% +framework for students and then from + + + align:start position:0% +framework for students and then from +that I guess you can fire the wood and + + align:start position:0% +that I guess you can fire the wood and + + + align:start position:0% +that I guess you can fire the wood and +the situated. Yeah. Good. Good. I like + + align:start position:0% +the situated. Yeah. Good. Good. I like + + + align:start position:0% +the situated. Yeah. Good. Good. I like +it. I like it. Yeah. Yeah. What are the + + align:start position:0% +it. I like it. Yeah. Yeah. What are the + + + align:start position:0% +it. I like it. Yeah. Yeah. What are the +I think that's a great question to ask. + + align:start position:0% +I think that's a great question to ask. + + + align:start position:0% +I think that's a great question to ask. +What are the different sort of + + align:start position:0% +What are the different sort of + + + align:start position:0% +What are the different sort of +combination and permutations like the + + align:start position:0% +combination and permutations like the + + + align:start position:0% +combination and permutations like the +reason why these ideas have existed that + + align:start position:0% +reason why these ideas have existed that + + + align:start position:0% +reason why these ideas have existed that +we can find evidence of them for 2,000 + + align:start position:0% +we can find evidence of them for 2,000 + + + align:start position:0% +we can find evidence of them for 2,000 +years is that like they both seem pretty + + align:start position:0% +years is that like they both seem pretty + + + align:start position:0% +years is that like they both seem pretty +good. Um they both seem useful in + + align:start position:0% +good. Um they both seem useful in + + + align:start position:0% +good. Um they both seem useful in +different ways. You know, here you know + + align:start position:0% +different ways. You know, here you know + + + align:start position:0% +different ways. You know, here you know +here is here you know um Seymour Papard + + align:start position:0% +here is here you know um Seymour Papard + + + align:start position:0% +here is here you know um Seymour Papard +is once talking about like his teachers + + align:start position:0% +is once talking about like his teachers + + + align:start position:0% +is once talking about like his teachers +lying to them and despising schools. But + + align:start position:0% +lying to them and despising schools. But + + + align:start position:0% +lying to them and despising schools. But +you can also find sort of school things + + align:start position:0% +you can also find sort of school things + + + align:start position:0% +you can also find sort of school things +like we're going to need some + + align:start position:0% +like we're going to need some + + + align:start position:0% +like we're going to need some +definitions that I teach you um that are + + align:start position:0% +definitions that I teach you um that are + + + align:start position:0% +definitions that I teach you um that are +kind of woven even in this sort of + + align:start position:0% +kind of woven even in this sort of + + + align:start position:0% +kind of woven even in this sort of +extreme example. Um let me give you a + + align:start position:0% +extreme example. Um let me give you a + + + align:start position:0% +extreme example. Um let me give you a +few pieces from the thing that you read + + align:start position:0% +few pieces from the thing that you read + + + align:start position:0% +few pieces from the thing that you read +u from a guy named Jean Le um who with + + align:start position:0% +u from a guy named Jean Le um who with + + + align:start position:0% +u from a guy named Jean Le um who with +another person named Eddiad Winganger um + + align:start position:0% +another person named Eddiad Winganger um + + + align:start position:0% +another person named Eddiad Winganger um +really advanced some of these ideas. Um + + align:start position:0% +really advanced some of these ideas. Um + + + align:start position:0% +really advanced some of these ideas. Um +and I want you to like be thinking about + + align:start position:0% +and I want you to like be thinking about + + + align:start position:0% +and I want you to like be thinking about +like so how is the like what are the + + align:start position:0% +like so how is the like what are the + + + align:start position:0% +like so how is the like what are the +methods that this person uses to study? + + align:start position:0% +methods that this person uses to study? + + + align:start position:0% +methods that this person uses to study? +What are the kind of arguments they + + align:start position:0% +What are the kind of arguments they + + + align:start position:0% +What are the kind of arguments they +make? What are the implications for + + align:start position:0% +make? What are the implications for + + + align:start position:0% +make? What are the implications for +pedagogy? what's their framework about + + align:start position:0% +pedagogy? what's their framework about + + + align:start position:0% +pedagogy? what's their framework about +um human beings and how they learn and + + align:start position:0% +um human beings and how they learn and + + + align:start position:0% +um human beings and how they learn and +where do these things lap and overlap + + align:start position:0% +where do these things lap and overlap + + + align:start position:0% +where do these things lap and overlap +you know some like it can often seem + + align:start position:0% +you know some like it can often seem + + + align:start position:0% +you know some like it can often seem +like when you're writing about you know + + align:start position:0% +like when you're writing about you know + + + align:start position:0% +like when you're writing about you know +if you read a bunch of stuff on + + align:start position:0% +if you read a bunch of stuff on + + + align:start position:0% +if you read a bunch of stuff on +cognitive load theory it seems like + + align:start position:0% +cognitive load theory it seems like + + + align:start position:0% +cognitive load theory it seems like +they're just talking about instruction + + align:start position:0% +they're just talking about instruction + + + align:start position:0% +they're just talking about instruction +and they mostly are but they're ways at + + align:start position:0% +and they mostly are but they're ways at + + + align:start position:0% +and they mostly are but they're ways at +talking about instruction that evoke + + align:start position:0% +talking about instruction that evoke + + + align:start position:0% +talking about instruction that evoke +their beliefs about culture that evoke + + align:start position:0% +their beliefs about culture that evoke + + + align:start position:0% +their beliefs about culture that evoke +their beliefs about values that evoke + + align:start position:0% +their beliefs about values that evoke + + + align:start position:0% +their beliefs about values that evoke +their beliefs around methods and + + align:start position:0% +their beliefs around methods and + + + align:start position:0% +their beliefs around methods and +outcomes even if they don't talk about + + align:start position:0% +outcomes even if they don't talk about + + + align:start position:0% +outcomes even if they don't talk about +those things as much in this chapter I + + align:start position:0% +those things as much in this chapter I + + + align:start position:0% +those things as much in this chapter I +propose to consider learning not as a + + align:start position:0% +propose to consider learning not as a + + + align:start position:0% +propose to consider learning not as a +process process of socially shared + + align:start position:0% +process process of socially shared + + + align:start position:0% +process process of socially shared +cognition that results in the end in the + + align:start position:0% +cognition that results in the end in the + + + align:start position:0% +cognition that results in the end in the +internalization of knowledge by + + align:start position:0% +internalization of knowledge by + + + align:start position:0% +internalization of knowledge by +individuals but as a process of becoming + + align:start position:0% +individuals but as a process of becoming + + + align:start position:0% +individuals but as a process of becoming +a member of a sustained community of + + align:start position:0% +a member of a sustained community of + + + align:start position:0% +a member of a sustained community of +practice. Um so anytime you read + + align:start position:0% +practice. Um so anytime you read + + + align:start position:0% +practice. Um so anytime you read +anything a thing that you're almost all + + align:start position:0% +anything a thing that you're almost all + + + align:start position:0% +anything a thing that you're almost all +probably trained to do is try to figure + + align:start position:0% +probably trained to do is try to figure + + + align:start position:0% +probably trained to do is try to figure +out like what is the person's core + + align:start position:0% +out like what is the person's core + + + align:start position:0% +out like what is the person's core +argument like what is the thing they're + + align:start position:0% +argument like what is the thing they're + + + align:start position:0% +argument like what is the thing they're +arguing for. An equally useful thing to + + align:start position:0% +arguing for. An equally useful thing to + + + align:start position:0% +arguing for. An equally useful thing to +do almost anytime you read anything is + + align:start position:0% +do almost anytime you read anything is + + + align:start position:0% +do almost anytime you read anything is +to try to figure out what is this person + + align:start position:0% +to try to figure out what is this person + + + align:start position:0% +to try to figure out what is this person +arguing against. Um, and people are + + align:start position:0% +arguing against. Um, and people are + + + align:start position:0% +arguing against. Um, and people are +often not that explicit. Um, you know, + + align:start position:0% +often not that explicit. Um, you know, + + + align:start position:0% +often not that explicit. Um, you know, +he's not sort of saying like these jerks + + align:start position:0% +he's not sort of saying like these jerks + + + align:start position:0% +he's not sort of saying like these jerks +who are really like big on schools and + + align:start position:0% +who are really like big on schools and + + + align:start position:0% +who are really like big on schools and +direct instruction have totally missed + + align:start position:0% +direct instruction have totally missed + + + align:start position:0% +direct instruction have totally missed +this stuff. But there's that's kind of + + align:start position:0% +this stuff. But there's that's kind of + + + align:start position:0% +this stuff. But there's that's kind of +what he's he's getting at in here. And + + align:start position:0% +what he's he's getting at in here. And + + + align:start position:0% +what he's he's getting at in here. And +it's and it's a radical statement. + + align:start position:0% +it's and it's a radical statement. + + + align:start position:0% +it's and it's a radical statement. +Learning is not the internalization of + + align:start position:0% +Learning is not the internalization of + + + align:start position:0% +Learning is not the internalization of +knowledge. You know, last week I told + + align:start position:0% +knowledge. You know, last week I told + + + align:start position:0% +knowledge. You know, last week I told +you that for some of these kind of + + align:start position:0% +you that for some of these kind of + + + align:start position:0% +you that for some of these kind of +educational psychology people, memory is + + align:start position:0% +educational psychology people, memory is + + + align:start position:0% +educational psychology people, memory is +the residue of thought. Like the entire + + align:start position:0% +the residue of thought. Like the entire + + + align:start position:0% +the residue of thought. Like the entire +end point of cognitive load theory is to + + align:start position:0% +end point of cognitive load theory is to + + + align:start position:0% +end point of cognitive load theory is to +store memories facts as memories in our + + align:start position:0% +store memories facts as memories in our + + + align:start position:0% +store memories facts as memories in our +long-term memory. Um not as the + + align:start position:0% +long-term memory. Um not as the + + + align:start position:0% +long-term memory. Um not as the +internalization of knowledge as + + align:start position:0% +internalization of knowledge as + + + align:start position:0% +internalization of knowledge as +individuals but as a process of becoming + + align:start position:0% +individuals but as a process of becoming + + + align:start position:0% +individuals but as a process of becoming +a member of a sustained community of + + align:start position:0% +a member of a sustained community of + + + align:start position:0% +a member of a sustained community of +practice developing an identity as a + + align:start position:0% +practice developing an identity as a + + + align:start position:0% +practice developing an identity as a +member of a community and becoming + + align:start position:0% +member of a community and becoming + + + align:start position:0% +member of a community and becoming +knowledgeably skillful are part of the + + align:start position:0% +knowledgeably skillful are part of the + + + align:start position:0% +knowledgeably skillful are part of the +same process. You cannot separate + + align:start position:0% +same process. You cannot separate + + + align:start position:0% +same process. You cannot separate +storing things in long-term memory from + + align:start position:0% +storing things in long-term memory from + + + align:start position:0% +storing things in long-term memory from +building relationships with other + + align:start position:0% +building relationships with other + + + align:start position:0% +building relationships with other +people. Um with the former motivating + + align:start position:0% +people. Um with the former motivating + + + align:start position:0% +people. Um with the former motivating +one of the key things that we remember + + align:start position:0% +one of the key things that we remember + + + align:start position:0% +one of the key things that we remember +our colleague Michael Pashan you know + + align:start position:0% +our colleague Michael Pashan you know + + + align:start position:0% +our colleague Michael Pashan you know +not a theory of everything where is the + + align:start position:0% +not a theory of everything where is the + + + align:start position:0% +not a theory of everything where is the +motivation with the former motivating + + align:start position:0% +motivation with the former motivating + + + align:start position:0% +motivation with the former motivating +shaping and giving meaning to the latter + + align:start position:0% +shaping and giving meaning to the latter + + + align:start position:0% +shaping and giving meaning to the latter +which it subsumes it is difficult to + + align:start position:0% +which it subsumes it is difficult to + + + align:start position:0% +which it subsumes it is difficult to +move from peripheral to full + + align:start position:0% +move from peripheral to full + + + align:start position:0% +move from peripheral to full +participation in today's world including + + align:start position:0% +participation in today's world including + + + align:start position:0% +participation in today's world including +workplaces and schools thereby + + align:start position:0% +workplaces and schools thereby + + + align:start position:0% +workplaces and schools thereby +developing knowledgeably skilled + + align:start position:0% +developing knowledgeably skilled + + + align:start position:0% +developing knowledgeably skilled +identities. This is because the + + align:start position:0% +identities. This is because the + + + align:start position:0% +identities. This is because the +processes by which we divide and sell + + align:start position:0% +processes by which we divide and sell + + + align:start position:0% +processes by which we divide and sell +labor, which are ubiquitous in our way + + align:start position:0% +labor, which are ubiquitous in our way + + + align:start position:0% +labor, which are ubiquitous in our way +of producing goods and services, + + align:start position:0% +of producing goods and services, + + + align:start position:0% +of producing goods and services, +including knowledge, truncate both the + + align:start position:0% +including knowledge, truncate both the + + + align:start position:0% +including knowledge, truncate both the +movement from peripheral to full + + align:start position:0% +movement from peripheral to full + + + align:start position:0% +movement from peripheral to full +participation in the scope of + + align:start position:0% +participation in the scope of + + + align:start position:0% +participation in the scope of +knowledgeable skill. Taken to an + + align:start position:0% +knowledgeable skill. Taken to an + + + align:start position:0% +knowledgeable skill. Taken to an +extreme, these processes separate + + align:start position:0% +extreme, these processes separate + + + align:start position:0% +extreme, these processes separate +identity from intended forms of + + align:start position:0% +identity from intended forms of + + + align:start position:0% +identity from intended forms of +knowledgeable practice. This view + + align:start position:0% +knowledgeable practice. This view + + + align:start position:0% +knowledgeable practice. This view +implies that learning and failure to + + align:start position:0% +implies that learning and failure to + + + align:start position:0% +implies that learning and failure to +learn are aspects of the same social + + align:start position:0% +learn are aspects of the same social + + + align:start position:0% +learn are aspects of the same social +historical processes and points to + + align:start position:0% +historical processes and points to + + + align:start position:0% +historical processes and points to +relationships between knowledgeability + + align:start position:0% +relationships between knowledgeability + + + align:start position:0% +relationships between knowledgeability +and identity as important focus for + + align:start position:0% +and identity as important focus for + + + align:start position:0% +and identity as important focus for +research. These jerks, these education + + align:start position:0% +research. These jerks, these education + + + align:start position:0% +research. These jerks, these education +psychologists keep trying to convince + + align:start position:0% +psychologists keep trying to convince + + + align:start position:0% +psychologists keep trying to convince +you that what learning is is just + + align:start position:0% +you that what learning is is just + + + align:start position:0% +you that what learning is is just +shoving stuff in your brain. It's not. + + align:start position:0% +shoving stuff in your brain. It's not. + + + align:start position:0% +shoving stuff in your brain. It's not. +There are always people around when + + align:start position:0% +There are always people around when + + + align:start position:0% +There are always people around when +we're learning. Even when we're learning + + align:start position:0% +we're learning. Even when we're learning + + + align:start position:0% +we're learning. Even when we're learning +by ourselves, reading books and stuff + + align:start position:0% +by ourselves, reading books and stuff + + + align:start position:0% +by ourselves, reading books and stuff +like that, there are people in our minds + + align:start position:0% +like that, there are people in our minds + + + align:start position:0% +like that, there are people in our minds +or communities that we see ourselves + + align:start position:0% +or communities that we see ourselves + + + align:start position:0% +or communities that we see ourselves +being part of. Um try, you know, trying + + align:start position:0% +being part of. Um try, you know, trying + + + align:start position:0% +being part of. Um try, you know, trying +to understand how learning happens in + + align:start position:0% +to understand how learning happens in + + + align:start position:0% +to understand how learning happens in +schools or any other learning + + align:start position:0% +schools or any other learning + + + align:start position:0% +schools or any other learning +environment without thinking about the + + align:start position:0% +environment without thinking about the + + + align:start position:0% +environment without thinking about the +social environment that people learn is + + align:start position:0% +social environment that people learn is + + + align:start position:0% +social environment that people learn is +bonkers, is nuts. Um, it just it it it + + align:start position:0% +bonkers, is nuts. Um, it just it it it + + + align:start position:0% +bonkers, is nuts. Um, it just it it it +denies a crucial part of our humanity. + + align:start position:0% +denies a crucial part of our humanity. + + + align:start position:0% +denies a crucial part of our humanity. +Um, here's a a blog post that you can + + align:start position:0% +Um, here's a a blog post that you can + + + align:start position:0% +Um, here's a a blog post that you can +look at later if you sort of follow + + align:start position:0% +look at later if you sort of follow + + + align:start position:0% +look at later if you sort of follow +this. It's by a wonderful math educator + + align:start position:0% +this. It's by a wonderful math educator + + + align:start position:0% +this. It's by a wonderful math educator +named Dan Meyer. Um, who has been trying + + align:start position:0% +named Dan Meyer. Um, who has been trying + + + align:start position:0% +named Dan Meyer. Um, who has been trying +to explain to people why he thinks AI + + align:start position:0% +to explain to people why he thinks AI + + + align:start position:0% +to explain to people why he thinks AI +chat bots are a stupid idea and will not + + align:start position:0% +chat bots are a stupid idea and will not + + + align:start position:0% +chat bots are a stupid idea and will not +work. Um, and and uh and the you know + + align:start position:0% +work. Um, and and uh and the you know + + + align:start position:0% +work. Um, and and uh and the you know +his core issue is like nobody wants to + + align:start position:0% +his core issue is like nobody wants to + + + align:start position:0% +his core issue is like nobody wants to +talk to a computer. Like maybe the + + align:start position:0% +talk to a computer. Like maybe the + + + align:start position:0% +talk to a computer. Like maybe the +computer can provide a sort of perfect + + align:start position:0% +computer can provide a sort of perfect + + + align:start position:0% +computer can provide a sort of perfect +direct instructional sequence, but like + + align:start position:0% +direct instructional sequence, but like + + + align:start position:0% +direct instructional sequence, but like +the kids who are in my eighth grade + + align:start position:0% +the kids who are in my eighth grade + + + align:start position:0% +the kids who are in my eighth grade +algebra classroom, they don't want to be + + align:start position:0% +algebra classroom, they don't want to be + + + align:start position:0% +algebra classroom, they don't want to be +there. They're not interested in + + align:start position:0% +there. They're not interested in + + + align:start position:0% +there. They're not interested in +algebra. Um I love this framing. He's, + + align:start position:0% +algebra. Um I love this framing. He's, + + + align:start position:0% +algebra. Um I love this framing. He's, +you know, he a students attend school to + + align:start position:0% +you know, he a students attend school to + + + align:start position:0% +you know, he a students attend school to +answer two questions. Who am I? And how + + align:start position:0% +answer two questions. Who am I? And how + + + align:start position:0% +answer two questions. Who am I? And how +do I do this? Those are the two things + + align:start position:0% +do I do this? Those are the two things + + + align:start position:0% +do I do this? Those are the two things +they're thinking about all the time. Who + + align:start position:0% +they're thinking about all the time. Who + + + align:start position:0% +they're thinking about all the time. Who +am I? And how do I do this? A chatbot + + align:start position:0% +am I? And how do I do this? A chatbot + + + align:start position:0% +am I? And how do I do this? A chatbot +cannot help you at all with the first + + align:start position:0% +cannot help you at all with the first + + + align:start position:0% +cannot help you at all with the first +question. Um but the other thing I want + + align:start position:0% +question. Um but the other thing I want + + + align:start position:0% +question. Um but the other thing I want +to bring up here and you can disagree + + align:start position:0% +to bring up here and you can disagree + + + align:start position:0% +to bring up here and you can disagree +with that and we'll talk about more when + + align:start position:0% +with that and we'll talk about more when + + + align:start position:0% +with that and we'll talk about more when +we talk about chatbots but um who am I + + align:start position:0% +we talk about chatbots but um who am I + + + align:start position:0% +we talk about chatbots but um who am I +and how do I do this? This is exactly + + align:start position:0% +and how do I do this? This is exactly + + + align:start position:0% +and how do I do this? This is exactly +what Jean La was discussing that + + align:start position:0% +what Jean La was discussing that + + + align:start position:0% +what Jean La was discussing that +identity cannot be separated from the + + align:start position:0% +identity cannot be separated from the + + + align:start position:0% +identity cannot be separated from the +acquisition of knowledge. Um and I think + + align:start position:0% +acquisition of knowledge. Um and I think + + + align:start position:0% +acquisition of knowledge. Um and I think +most of you probably if you think of + + align:start position:0% +most of you probably if you think of + + + align:start position:0% +most of you probably if you think of +your own classroom exper you know think + + align:start position:0% +your own classroom exper you know think + + + align:start position:0% +your own classroom exper you know think +of your own school experience like I + + align:start position:0% +of your own school experience like I + + + align:start position:0% +of your own school experience like I +spent a lot of time in middle school and + + align:start position:0% +spent a lot of time in middle school and + + + align:start position:0% +spent a lot of time in middle school and +high school thinking to myself in one + + align:start position:0% +high school thinking to myself in one + + + align:start position:0% +high school thinking to myself in one +form or another who am I? Um what do + + align:start position:0% +form or another who am I? Um what do + + + align:start position:0% +form or another who am I? Um what do +people think of me? What kinds of + + align:start position:0% +people think of me? What kinds of + + + align:start position:0% +people think of me? What kinds of +relationships do I have? Why am I here? + + align:start position:0% +relationships do I have? Why am I here? + + + align:start position:0% +relationships do I have? Why am I here? +What am I supposed to be doing? + + align:start position:0% +What am I supposed to be doing? + + + align:start position:0% +What am I supposed to be doing? +Um uh Jordan has carried out extensive + + align:start position:0% +Um uh Jordan has carried out extensive + + + align:start position:0% +Um uh Jordan has carried out extensive +field research in the Yakatan Maya wavel + + align:start position:0% +field research in the Yakatan Maya wavel + + + align:start position:0% +field research in the Yakatan Maya wavel +whose apprenticeship is quite different + + align:start position:0% +whose apprenticeship is quite different + + + align:start position:0% +whose apprenticeship is quite different +more effective and less exploitative + + align:start position:0% +more effective and less exploitative + + + align:start position:0% +more effective and less exploitative +than the butchers of marshall study. The + + align:start position:0% +than the butchers of marshall study. The + + + align:start position:0% +than the butchers of marshall study. The +apprentices are peripheral participants + + align:start position:0% +apprentices are peripheral participants + + + align:start position:0% +apprentices are peripheral participants +legitimate peripherence and legitimate + + align:start position:0% +legitimate peripherence and legitimate + + + align:start position:0% +legitimate peripherence and legitimate +peripheral to the practice of midy. What + + align:start position:0% +peripheral to the practice of midy. What + + + align:start position:0% +peripheral to the practice of midy. What +did you all take away from what you + + align:start position:0% +did you all take away from what you + + + align:start position:0% +did you all take away from what you +think like what is legitimate peripheral + + align:start position:0% +think like what is legitimate peripheral + + + align:start position:0% +think like what is legitimate peripheral +practice or periphery? Like what does + + align:start position:0% +practice or periphery? Like what does + + + align:start position:0% +practice or periphery? Like what does +that mean sort of in your own words? + + align:start position:0% +that mean sort of in your own words? + + + align:start position:0% +that mean sort of in your own words? +What do you think Dana? Like they're + + align:start position:0% +What do you think Dana? Like they're + + + align:start position:0% +What do you think Dana? Like they're +doing work that like matters, but + + align:start position:0% +doing work that like matters, but + + + align:start position:0% +doing work that like matters, but +they're not like doing the main work. + + align:start position:0% +they're not like doing the main work. + + + align:start position:0% +they're not like doing the main work. +Like they're doing side tasks that are + + align:start position:0% +Like they're doing side tasks that are + + + align:start position:0% +Like they're doing side tasks that are +like helping them understand the main + + align:start position:0% +like helping them understand the main + + + align:start position:0% +like helping them understand the main +process, but like they themselves are + + align:start position:0% +process, but like they themselves are + + + align:start position:0% +process, but like they themselves are +not like giving birth to the child. + + align:start position:0% +not like giving birth to the child. + + + align:start position:0% +not like giving birth to the child. +Good. Good. And and there's a space + + align:start position:0% +Good. Good. And and there's a space + + + align:start position:0% +Good. Good. And and there's a space +there. A space is held for those people. + + align:start position:0% +there. A space is held for those people. + + + align:start position:0% +there. A space is held for those people. +It is expected that there are going to + + align:start position:0% +It is expected that there are going to + + + align:start position:0% +It is expected that there are going to +be some folks who are hanging around + + align:start position:0% +be some folks who are hanging around + + + align:start position:0% +be some folks who are hanging around +midwives who are not quite midwives yet. + + align:start position:0% +midwives who are not quite midwives yet. + + + align:start position:0% +midwives who are not quite midwives yet. +And that's normal. They're supposed to + + align:start position:0% +And that's normal. They're supposed to + + + align:start position:0% +And that's normal. They're supposed to +be there. Um, it's not a classroom of 20 + + align:start position:0% +be there. Um, it's not a classroom of 20 + + + align:start position:0% +be there. Um, it's not a classroom of 20 +people all lined up who are supposed to + + align:start position:0% +people all lined up who are supposed to + + + align:start position:0% +people all lined up who are supposed to +be doing the same thing all the time. + + align:start position:0% +be doing the same thing all the time. + + + align:start position:0% +be doing the same thing all the time. +There's supposed to be some people in + + align:start position:0% +There's supposed to be some people in + + + align:start position:0% +There's supposed to be some people in +the middle and there's supposed to be + + align:start position:0% +the middle and there's supposed to be + + + align:start position:0% +the middle and there's supposed to be +some people on the outside. I want to + + align:start position:0% +some people on the outside. I want to + + + align:start position:0% +some people on the outside. I want to +pose a question too to think of the + + align:start position:0% +pose a question too to think of the + + + align:start position:0% +pose a question too to think of the +relationship between what uh Gene Le was + + align:start position:0% +relationship between what uh Gene Le was + + + align:start position:0% +relationship between what uh Gene Le was +talking about the midwives and the + + align:start position:0% +talking about the midwives and the + + + align:start position:0% +talking about the midwives and the +butchers in the thinking. What's the + + align:start position:0% +butchers in the thinking. What's the + + + align:start position:0% +butchers in the thinking. What's the +difference between peripheral + + align:start position:0% +difference between peripheral + + + align:start position:0% +difference between peripheral +participants and legitimately peripheral + + align:start position:0% +participants and legitimately peripheral + + + align:start position:0% +participants and legitimately peripheral +participants? Do folks remember what + + align:start position:0% +participants? Do folks remember what + + + align:start position:0% +participants? Do folks remember what +they described about the butchers? Yeah. + + align:start position:0% +they described about the butchers? Yeah. + + + align:start position:0% +they described about the butchers? Yeah. +Yeah. Yeah. Was that the butchers even + + align:start position:0% +Yeah. Yeah. Was that the butchers even + + + align:start position:0% +Yeah. Yeah. Was that the butchers even +though like they were doing peripheral + + align:start position:0% +though like they were doing peripheral + + + align:start position:0% +though like they were doing peripheral +work, they were separated in space from + + align:start position:0% +work, they were separated in space from + + + align:start position:0% +work, they were separated in space from +the like + + align:start position:0% +the like + + + align:start position:0% +the like +the experts. So they didn't they + + align:start position:0% +the experts. So they didn't they + + + align:start position:0% +the experts. So they didn't they +wouldn't really pick up on things as + + align:start position:0% +wouldn't really pick up on things as + + + align:start position:0% +wouldn't really pick up on things as +opposed to midwives who still observe + + align:start position:0% +opposed to midwives who still observe + + + align:start position:0% +opposed to midwives who still observe +what the legitimate the expert was + + align:start position:0% +what the legitimate the expert was + + + align:start position:0% +what the legitimate the expert was +doing. Yeah. So what does that mean in + + align:start position:0% +doing. Yeah. So what does that mean in + + + align:start position:0% +doing. Yeah. So what does that mean in +terms of being a part of that community + + align:start position:0% +terms of being a part of that community + + + align:start position:0% +terms of being a part of that community +and then shaping the learning that + + align:start position:0% +and then shaping the learning that + + + align:start position:0% +and then shaping the learning that +they're able to + + align:start position:0% +they're able to + + + align:start position:0% +they're able to +acquire? If I'm a butcher and I'm I'm + + align:start position:0% +acquire? If I'm a butcher and I'm I'm + + + align:start position:0% +acquire? If I'm a butcher and I'm I'm +part of the community, if I'm standing + + align:start position:0% +part of the community, if I'm standing + + + align:start position:0% +part of the community, if I'm standing +over here cutting my meat, using my + + align:start position:0% +over here cutting my meat, using my + + + align:start position:0% +over here cutting my meat, using my +tool, that's all I get to do. And then + + align:start position:0% +tool, that's all I get to do. And then + + + align:start position:0% +tool, that's all I get to do. And then +Justin's over there, you know, hanging + + align:start position:0% +Justin's over there, you know, hanging + + + align:start position:0% +Justin's over there, you know, hanging +out with the pig or whatever it is, + + align:start position:0% +out with the pig or whatever it is, + + + align:start position:0% +out with the pig or whatever it is, +right? What am I losing then? The social + + align:start position:0% +right? What am I losing then? The social + + + align:start position:0% +right? What am I losing then? The social +aspect. The social aspect, right? Am I + + align:start position:0% +aspect. The social aspect, right? Am I + + + align:start position:0% +aspect. The social aspect, right? Am I +able to observe him? Can I see what he's + + align:start position:0% +able to observe him? Can I see what he's + + + align:start position:0% +able to observe him? Can I see what he's +doing when he leaves? Can I pick it up + + align:start position:0% +doing when he leaves? Can I pick it up + + + align:start position:0% +doing when he leaves? Can I pick it up +from watching? Totally miss that. But + + align:start position:0% +from watching? Totally miss that. But + + + align:start position:0% +from watching? Totally miss that. But +then what about the midwife? How's that + + align:start position:0% +then what about the midwife? How's that + + + align:start position:0% +then what about the midwife? How's that +different? + + align:start position:0% +different? + + + align:start position:0% +different? +How do they describe the midwife + + align:start position:0% +How do they describe the midwife + + + align:start position:0% +How do they describe the midwife +relationship? Justin, I hope this is + + align:start position:0% +relationship? Justin, I hope this is + + + align:start position:0% +relationship? Justin, I hope this is +okay. I love this book. So, yeah. Go + + align:start position:0% +okay. I love this book. So, yeah. Go + + + align:start position:0% +okay. I love this book. So, yeah. Go +ahead. Um, so I think the one of the + + align:start position:0% +ahead. Um, so I think the one of the + + + align:start position:0% +ahead. Um, so I think the one of the +main differences is beyond the fact that + + align:start position:0% +main differences is beyond the fact that + + + align:start position:0% +main differences is beyond the fact that +it wasn't supposed to be more efficient. + + align:start position:0% +it wasn't supposed to be more efficient. + + + align:start position:0% +it wasn't supposed to be more efficient. +So there was no capitalist aspect to it. + + align:start position:0% +So there was no capitalist aspect to it. + + + align:start position:0% +So there was no capitalist aspect to it. +There was a lot of culture embedded in + + align:start position:0% +There was a lot of culture embedded in + + + align:start position:0% +There was a lot of culture embedded in +it. So like the daughter of a midwife + + align:start position:0% +it. So like the daughter of a midwife + + + align:start position:0% +it. So like the daughter of a midwife +would become midwife, meaning that at 5 + + align:start position:0% +would become midwife, meaning that at 5 + + + align:start position:0% +would become midwife, meaning that at 5 +years old, they would already kind of be + + align:start position:0% +years old, they would already kind of be + + + align:start position:0% +years old, they would already kind of be +present in that situation and start like + + align:start position:0% +present in that situation and start like + + + align:start position:0% +present in that situation and start like +picking up on what was going on and then + + align:start position:0% +picking up on what was going on and then + + + align:start position:0% +picking up on what was going on and then +progressively have a more like + + align:start position:0% +progressively have a more like + + + align:start position:0% +progressively have a more like +protagonist role to that experience. So + + align:start position:0% +protagonist role to that experience. So + + + align:start position:0% +protagonist role to that experience. So +yeah. So like although both could be + + align:start position:0% +yeah. So like although both could be + + + align:start position:0% +yeah. So like although both could be +argued as peripheral, right? We're we're + + align:start position:0% +argued as peripheral, right? We're we're + + + align:start position:0% +argued as peripheral, right? We're we're +in the same space. We're hanging out. + + align:start position:0% +in the same space. We're hanging out. + + + align:start position:0% +in the same space. We're hanging out. +Like who's welcome in the community and + + align:start position:0% +Like who's welcome in the community and + + + align:start position:0% +Like who's welcome in the community and +then what type of knowledge are you able + + align:start position:0% +then what type of knowledge are you able + + + align:start position:0% +then what type of knowledge are you able +to gain from that type of peripheral + + align:start position:0% +to gain from that type of peripheral + + + align:start position:0% +to gain from that type of peripheral +participation? It's kind of cool. It's + + align:start position:0% +participation? It's kind of cool. It's + + + align:start position:0% +participation? It's kind of cool. It's +subtle, right? Yeah. All right. That's + + align:start position:0% +subtle, right? Yeah. All right. That's + + + align:start position:0% +subtle, right? Yeah. All right. That's +all I got. I have Can I make Okay. + + align:start position:0% +all I got. I have Can I make Okay. + + + align:start position:0% +all I got. I have Can I make Okay. +um the the previous paragraph I had a + + align:start position:0% +um the the previous paragraph I had a + + + align:start position:0% +um the the previous paragraph I had a +lot of reflection about it and I don't + + align:start position:0% +lot of reflection about it and I don't + + + align:start position:0% +lot of reflection about it and I don't +nec like kind of that in some aspects + + align:start position:0% +nec like kind of that in some aspects + + + align:start position:0% +nec like kind of that in some aspects +I'm not sure how you feel about it but + + align:start position:0% +I'm not sure how you feel about it but + + + align:start position:0% +I'm not sure how you feel about it but +like I really like the point that he + + align:start position:0% +like I really like the point that he + + + align:start position:0% +like I really like the point that he +makes about like learning kind of makes + + align:start position:0% +makes about like learning kind of makes + + + align:start position:0% +makes about like learning kind of makes +forms your identity as part of this + + align:start position:0% +forms your identity as part of this + + + align:start position:0% +forms your identity as part of this +social group right and I think that + + align:start position:0% +social group right and I think that + + + align:start position:0% +social group right and I think that +really applies to kids for example kind + + align:start position:0% +really applies to kids for example kind + + + align:start position:0% +really applies to kids for example kind +of like they come from this per + + align:start position:0% +of like they come from this per + + + align:start position:0% +of like they come from this per +peripheral existence and develop their + + align:start position:0% +peripheral existence and develop their + + + align:start position:0% +peripheral existence and develop their +own identities and become like a + + align:start position:0% +own identities and become like a + + + align:start position:0% +own identities and become like a +committed like functioning part of + + align:start position:0% +committed like functioning part of + + + align:start position:0% +committed like functioning part of +society. But then it really made me + + align:start position:0% +society. But then it really made me + + + align:start position:0% +society. But then it really made me +think like oh how do we think about it + + align:start position:0% +think like oh how do we think about it + + + align:start position:0% +think like oh how do we think about it +like from an abbleist um perspective + + align:start position:0% +like from an abbleist um perspective + + + align:start position:0% +like from an abbleist um perspective +right where people cannot acquire + + align:start position:0% +right where people cannot acquire + + + align:start position:0% +right where people cannot acquire +certain knowledges or certain abilities + + align:start position:0% +certain knowledges or certain abilities + + + align:start position:0% +certain knowledges or certain abilities +and does that mean they have less of an + + align:start position:0% +and does that mean they have less of an + + + align:start position:0% +and does that mean they have less of an +identity like I really thought about + + align:start position:0% +identity like I really thought about + + + align:start position:0% +identity like I really thought about +that for a while and at the same time + + align:start position:0% +that for a while and at the same time + + + align:start position:0% +that for a while and at the same time +there's like a criticism in the book + + align:start position:0% +there's like a criticism in the book + + + align:start position:0% +there's like a criticism in the book +about like commoditization of knowledge + + align:start position:0% +about like commoditization of knowledge + + + align:start position:0% +about like commoditization of knowledge +because before like with midwives etc + + align:start position:0% +because before like with midwives etc + + + align:start position:0% +because before like with midwives etc +like okay it was this really specific + + align:start position:0% +like okay it was this really specific + + + align:start position:0% +like okay it was this really specific +group of people teaching this very kind + + align:start position:0% +group of people teaching this very kind + + + align:start position:0% +group of people teaching this very kind +of like expertise u whereas today we + + align:start position:0% +of like expertise u whereas today we + + + align:start position:0% +of like expertise u whereas today we +have universities and we have schools or + + align:start position:0% +have universities and we have schools or + + + align:start position:0% +have universities and we have schools or +you can kind of get to whatever class + + align:start position:0% +you can kind of get to whatever class + + + align:start position:0% +you can kind of get to whatever class +and learn things, but it's not + + align:start position:0% +and learn things, but it's not + + + align:start position:0% +and learn things, but it's not +necessarily all bad, right? Because that + + align:start position:0% +necessarily all bad, right? Because that + + + align:start position:0% +necessarily all bad, right? Because that +would imply that if you're the daughter + + align:start position:0% +would imply that if you're the daughter + + + align:start position:0% +would imply that if you're the daughter +of the midwife, you don't really have a + + align:start position:0% +of the midwife, you don't really have a + + + align:start position:0% +of the midwife, you don't really have a +lot of say into becoming or not a + + align:start position:0% +lot of say into becoming or not a + + + align:start position:0% +lot of say into becoming or not a +midwife, right? Like the way that + + align:start position:0% +midwife, right? Like the way that + + + align:start position:0% +midwife, right? Like the way that +society was structured back then likely + + align:start position:0% +society was structured back then likely + + + align:start position:0% +society was structured back then likely +you would kind of become one because + + align:start position:0% +you would kind of become one because + + + align:start position:0% +you would kind of become one because +that's what expected of you. Whereas + + align:start position:0% +that's what expected of you. Whereas + + + align:start position:0% +that's what expected of you. Whereas +like when you kind of can choose that + + align:start position:0% +like when you kind of can choose that + + + align:start position:0% +like when you kind of can choose that +you have some sort of agency and power + + align:start position:0% +you have some sort of agency and power + + + align:start position:0% +you have some sort of agency and power +even if you won't have that exposure as + + align:start position:0% +even if you won't have that exposure as + + + align:start position:0% +even if you won't have that exposure as +a peripheral participant since a since + + align:start position:0% +a peripheral participant since a since + + + align:start position:0% +a peripheral participant since a since +you were a kid. So like it really made + + align:start position:0% +you were a kid. So like it really made + + + align:start position:0% +you were a kid. So like it really made +me think of many things. Great. Good. + + align:start position:0% +me think of many things. Great. Good. + + + align:start position:0% +me think of many things. Great. Good. +Good. And and none of them have to be + + align:start position:0% +Good. And and none of them have to be + + + align:start position:0% +Good. And and none of them have to be +resolved either. Um you know that that + + align:start position:0% +resolved either. Um you know that that + + + align:start position:0% +resolved either. Um you know that that +uh um probably probably some important + + align:start position:0% +uh um probably probably some important + + + align:start position:0% +uh um probably probably some important +things to take away are like how Jean + + align:start position:0% +things to take away are like how Jean + + + align:start position:0% +things to take away are like how Jean +assigns values to these different kinds + + align:start position:0% +assigns values to these different kinds + + + align:start position:0% +assigns values to these different kinds +of institutions. like he thinks it's a + + align:start position:0% +of institutions. like he thinks it's a + + + align:start position:0% +of institutions. like he thinks it's a +big problem, you know, a big problem + + align:start position:0% +big problem, you know, a big problem + + + align:start position:0% +big problem, you know, a big problem +with schools and university is sort of + + align:start position:0% +with schools and university is sort of + + + align:start position:0% +with schools and university is sort of +ripping knowledge away from these + + align:start position:0% +ripping knowledge away from these + + + align:start position:0% +ripping knowledge away from these +broader social contexts. Um that you go + + align:start position:0% +broader social contexts. Um that you go + + + align:start position:0% +broader social contexts. Um that you go +and take a physics class and in the vast + + align:start position:0% +and take a physics class and in the vast + + + align:start position:0% +and take a physics class and in the vast +majority of physics 101 classes, no one + + align:start position:0% +majority of physics 101 classes, no one + + + align:start position:0% +majority of physics 101 classes, no one +is trying to get you to be a physicist. + + align:start position:0% +is trying to get you to be a physicist. + + + align:start position:0% +is trying to get you to be a physicist. +They're not trying to get you to develop + + align:start position:0% +They're not trying to get you to develop + + + align:start position:0% +They're not trying to get you to develop +the identity of a physicist. They're + + align:start position:0% +the identity of a physicist. They're + + + align:start position:0% +the identity of a physicist. They're +just trying to teach you the physics. + + align:start position:0% +just trying to teach you the physics. + + + align:start position:0% +just trying to teach you the physics. +And what is lost sort of in that? Of + + align:start position:0% +And what is lost sort of in that? Of + + + align:start position:0% +And what is lost sort of in that? Of +course, what's pretty rad about like + + align:start position:0% +course, what's pretty rad about like + + + align:start position:0% +course, what's pretty rad about like +walking into a campus full of people who + + align:start position:0% +walking into a campus full of people who + + + align:start position:0% +walking into a campus full of people who +will be like, "Yeah, I'll teach you any + + align:start position:0% +will be like, "Yeah, I'll teach you any + + + align:start position:0% +will be like, "Yeah, I'll teach you any +of these atomized little things for you + + align:start position:0% +of these atomized little things for you + + + align:start position:0% +of these atomized little things for you +to learn." like that seems kind of cool + + align:start position:0% +to learn." like that seems kind of cool + + + align:start position:0% +to learn." like that seems kind of cool +too. Um it is worth noting that it would + + align:start position:0% +too. Um it is worth noting that it would + + + align:start position:0% +too. Um it is worth noting that it would +be difficult to find evidence that + + align:start position:0% +be difficult to find evidence that + + + align:start position:0% +be difficult to find evidence that +teaching is the mode of knowledge + + align:start position:0% +teaching is the mode of knowledge + + + align:start position:0% +teaching is the mode of knowledge +transmission amongst the midwives. Um he + + align:start position:0% +transmission amongst the midwives. Um he + + + align:start position:0% +transmission amongst the midwives. Um he +makes this claim that like you wouldn't + + align:start position:0% +makes this claim that like you wouldn't + + + align:start position:0% +makes this claim that like you wouldn't +find direct instruction amongst the + + align:start position:0% +find direct instruction amongst the + + + align:start position:0% +find direct instruction amongst the +midwives. Um I mean Jordan did the fil + + align:start position:0% +midwives. Um I mean Jordan did the fil + + + align:start position:0% +midwives. Um I mean Jordan did the fil +work and not me. That seems totally + + align:start position:0% +work and not me. That seems totally + + + align:start position:0% +work and not me. That seems totally +laughable to me. I've spent time with + + align:start position:0% +laughable to me. I've spent time with + + + align:start position:0% +laughable to me. I've spent time with +lots of people of lots of ages, learns + + align:start position:0% +lots of people of lots of ages, learns + + + align:start position:0% +lots of people of lots of ages, learns +lots of kinds of things and people are + + align:start position:0% +lots of kinds of things and people are + + + align:start position:0% +lots of kinds of things and people are +always transmitting and explaining + + align:start position:0% +always transmitting and explaining + + + align:start position:0% +always transmitting and explaining +stuff. It's always sort of nested in + + align:start position:0% +stuff. It's always sort of nested in + + + align:start position:0% +stuff. It's always sort of nested in +there. Um but there's a kind of politics + + align:start position:0% +there. Um but there's a kind of politics + + + align:start position:0% +there. Um but there's a kind of politics +of John Lave like we don't even need to + + align:start position:0% +of John Lave like we don't even need to + + + align:start position:0% +of John Lave like we don't even need to +explain these things. We don't even need + + align:start position:0% +explain these things. We don't even need + + + align:start position:0% +explain these things. We don't even need +to teach these people. We can learn it + + align:start position:0% +to teach these people. We can learn it + + + align:start position:0% +to teach these people. We can learn it +just like babies learn it sort of in + + align:start position:0% +just like babies learn it sort of in + + + align:start position:0% +just like babies learn it sort of in +their natural environment. You just you + + align:start position:0% +their natural environment. You just you + + + align:start position:0% +their natural environment. You just you +know just like you have to surround + + align:start position:0% +know just like you have to surround + + + align:start position:0% +know just like you have to surround +babies with language and they'll learn + + align:start position:0% +babies with language and they'll learn + + + align:start position:0% +babies with language and they'll learn +language. You surround young girls with + + align:start position:0% +language. You surround young girls with + + + align:start position:0% +language. You surround young girls with +birth and pregnancy and they learn + + align:start position:0% +birth and pregnancy and they learn + + + align:start position:0% +birth and pregnancy and they learn +midwiffery. Um + + align:start position:0% +midwiffery. Um + + + align:start position:0% +midwiffery. Um +uh apprenticeship happens as a way in + + align:start position:0% +uh apprenticeship happens as a way in + + + align:start position:0% +uh apprenticeship happens as a way in +the course of daily life. It may not be + + align:start position:0% +the course of daily life. It may not be + + + align:start position:0% +the course of daily life. It may not be +recognized as teaching effort at all. + + align:start position:0% +recognized as teaching effort at all. + + + align:start position:0% +recognized as teaching effort at all. +Again sort of doubling down like there's + + align:start position:0% +Again sort of doubling down like there's + + + align:start position:0% +Again sort of doubling down like there's +no instruction here. If there + + align:start position:0% +no instruction here. If there + + + align:start position:0% +no instruction here. If there +instruction, the people are lying to you + + align:start position:0% +instruction, the people are lying to you + + + align:start position:0% +instruction, the people are lying to you +and you should despise them. Um, a Maya + + align:start position:0% +and you should despise them. Um, a Maya + + + align:start position:0% +and you should despise them. Um, a Maya +girl who eventually became a midwife + + align:start position:0% +girl who eventually became a midwife + + + align:start position:0% +girl who eventually became a midwife +most likely as a mother, a grandmother + + align:start position:0% +most likely as a mother, a grandmother + + + align:start position:0% +most likely as a mother, a grandmother +as a midwife. Girls in such families + + align:start position:0% +as a midwife. Girls in such families + + + align:start position:0% +as a midwife. Girls in such families +without being identified as apprentice + + align:start position:0% +without being identified as apprentice + + + align:start position:0% +without being identified as apprentice +midwives absorb the effence of midwife + + align:start position:0% +midwives absorb the effence of midwife + + + align:start position:0% +midwives absorb the effence of midwife +practice as well as specific knowledge + + align:start position:0% +practice as well as specific knowledge + + + align:start position:0% +practice as well as specific knowledge +about many procedures simply in the + + align:start position:0% +about many procedures simply in the + + + align:start position:0% +about many procedures simply in the +process of growing up. They know what + + align:start position:0% +process of growing up. They know what + + + align:start position:0% +process of growing up. They know what +the life of a midwife is like, what + + align:start position:0% +the life of a midwife is like, what + + + align:start position:0% +the life of a midwife is like, what +kinds of stories the women and men who + + align:start position:0% +kinds of stories the women and men who + + + align:start position:0% +kinds of stories the women and men who +come to consult her tell, what kind of + + align:start position:0% +come to consult her tell, what kind of + + + align:start position:0% +come to consult her tell, what kind of +herbs and other remedies might be needed + + align:start position:0% +herbs and other remedies might be needed + + + align:start position:0% +herbs and other remedies might be needed +to collected. As young children, they + + align:start position:0% +to collected. As young children, they + + + align:start position:0% +to collected. As young children, they +might be sitting quietly in their + + align:start position:0% +might be sitting quietly in their + + + align:start position:0% +might be sitting quietly in their +corner. As their minister mother + + align:start position:0% +corner. As their minister mother + + + align:start position:0% +corner. As their minister mother +administers a prenatal massage, they + + align:start position:0% +administers a prenatal massage, they + + + align:start position:0% +administers a prenatal massage, they +would hear stories of difficult cases of + + align:start position:0% +would hear stories of difficult cases of + + + align:start position:0% +would hear stories of difficult cases of +miraculous outcomes and the like. As + + align:start position:0% +miraculous outcomes and the like. As + + + align:start position:0% +miraculous outcomes and the like. As +they grow older, they may be passing + + align:start position:0% +they grow older, they may be passing + + + align:start position:0% +they grow older, they may be passing +messages, running errands, getting + + align:start position:0% +messages, running errands, getting + + + align:start position:0% +messages, running errands, getting +needed supplies. A young girl might be + + align:start position:0% +needed supplies. A young girl might be + + + align:start position:0% +needed supplies. A young girl might be +present as her mother stops for a + + align:start position:0% +present as her mother stops for a + + + align:start position:0% +present as her mother stops for a +postpartum visit after the daily + + align:start position:0% +postpartum visit after the daily + + + align:start position:0% +postpartum visit after the daily +shopping trip to the market. Eventually, + + align:start position:0% +shopping trip to the market. Eventually, + + + align:start position:0% +shopping trip to the market. Eventually, +after she has a child herself, she might + + align:start position:0% +after she has a child herself, she might + + + align:start position:0% +after she has a child herself, she might +come along to her birth, perhaps because + + align:start position:0% +come along to her birth, perhaps because + + + align:start position:0% +come along to her birth, perhaps because +her alien grandmother needs someone to + + align:start position:0% +her alien grandmother needs someone to + + + align:start position:0% +her alien grandmother needs someone to +walk with, and thus finds herself doing + + align:start position:0% +walk with, and thus finds herself doing + + + align:start position:0% +walk with, and thus finds herself doing +for the woman in labor what other women + + align:start position:0% +for the woman in labor what other women + + + align:start position:0% +for the woman in labor what other women +had done for her when she gave birth. + + align:start position:0% +had done for her when she gave birth. + + + align:start position:0% +had done for her when she gave birth. +That is, she may take a turn at + + align:start position:0% +That is, she may take a turn at + + + align:start position:0% +That is, she may take a turn at +supporting the laboring woman. + + align:start position:0% +supporting the laboring woman. + + + align:start position:0% +supporting the laboring woman. +Eventually, she may even administer + + align:start position:0% +Eventually, she may even administer + + + align:start position:0% +Eventually, she may even administer +prenatal massages to the selected + + align:start position:0% +prenatal massages to the selected + + + align:start position:0% +prenatal massages to the selected +clients. At some point, she may decide + + align:start position:0% +clients. At some point, she may decide + + + align:start position:0% +clients. At some point, she may decide +she actually wants to do this kind of + + align:start position:0% +she actually wants to do this kind of + + + align:start position:0% +she actually wants to do this kind of +work. She then pays more attention, but + + align:start position:0% +work. She then pays more attention, but + + + align:start position:0% +work. She then pays more attention, but +only rarely does she ask questions. Her + + align:start position:0% +only rarely does she ask questions. Her + + + align:start position:0% +only rarely does she ask questions. Her +mentor sees their association, primarily + + align:start position:0% +mentor sees their association, primarily + + + align:start position:0% +mentor sees their association, primarily +one that is of some use to her. Rosa + + align:start position:0% +one that is of some use to her. Rosa + + + align:start position:0% +one that is of some use to her. Rosa +already knows how to do a massage, so I + + align:start position:0% +already knows how to do a massage, so I + + + align:start position:0% +already knows how to do a massage, so I +can send her if I'm too busy. Um, that + + align:start position:0% +can send her if I'm too busy. Um, that + + + align:start position:0% +can send her if I'm too busy. Um, that +is just a beautiful description of kind + + align:start position:0% +is just a beautiful description of kind + + + align:start position:0% +is just a beautiful description of kind +of legitimate peripheral participation, + + align:start position:0% +of legitimate peripheral participation, + + + align:start position:0% +of legitimate peripheral participation, +moving from the periphery to the center. + + align:start position:0% +moving from the periphery to the center. + + + align:start position:0% +moving from the periphery to the center. +You just watch this thing for a while + + align:start position:0% +You just watch this thing for a while + + + align:start position:0% +You just watch this thing for a while +and then your mom's hands are a little + + align:start position:0% +and then your mom's hands are a little + + + align:start position:0% +and then your mom's hands are a little +sore and so you do the massage this time + + align:start position:0% +sore and so you do the massage this time + + + align:start position:0% +sore and so you do the massage this time +and you know how to move the massage cuz + + align:start position:0% +and you know how to move the massage cuz + + + align:start position:0% +and you know how to move the massage cuz +it happened to you. You've seen it a + + align:start position:0% +it happened to you. You've seen it a + + + align:start position:0% +it happened to you. You've seen it a +zillion times. Are any of you part of + + align:start position:0% +zillion times. Are any of you part of + + + align:start position:0% +zillion times. Are any of you part of +sort of clubs or groups at MIT that have + + align:start position:0% +sort of clubs or groups at MIT that have + + + align:start position:0% +sort of clubs or groups at MIT that have +learning that feels like this? + + align:start position:0% + + + + align:start position:0% + +I guess like technically a lot of + + align:start position:0% +I guess like technically a lot of + + + align:start position:0% +I guess like technically a lot of +theater clubs are similar where people + + align:start position:0% +theater clubs are similar where people + + + align:start position:0% +theater clubs are similar where people +are just doing this like how do you + + align:start position:0% +are just doing this like how do you + + + align:start position:0% +are just doing this like how do you +become a stage manager? I don't know. + + align:start position:0% +become a stage manager? I don't know. + + + align:start position:0% +become a stage manager? I don't know. +Look at what the stage hand. Oh, and and + + align:start position:0% +Look at what the stage hand. Oh, and and + + + align:start position:0% +Look at what the stage hand. Oh, and and +the other thing is like you start as a + + align:start position:0% +the other thing is like you start as a + + + align:start position:0% +the other thing is like you start as a +stage hand like Yeah. Yeah. Yeah. Come, + + align:start position:0% +stage hand like Yeah. Yeah. Yeah. Come, + + + align:start position:0% +stage hand like Yeah. Yeah. Yeah. Come, +you know, you watch some theater. Yeah. + + align:start position:0% +you know, you watch some theater. Yeah. + + + align:start position:0% +you know, you watch some theater. Yeah. +You know, just stand there and like + + align:start position:0% +You know, just stand there and like + + + align:start position:0% +You know, just stand there and like +you're like between the second and third + + align:start position:0% +you're like between the second and third + + + align:start position:0% +you're like between the second and third +act like hand this prop to that person. + + align:start position:0% +act like hand this prop to that person. + + + align:start position:0% +act like hand this prop to that person. +Um and you're probably never going to + + align:start position:0% +Um and you're probably never going to + + + align:start position:0% +Um and you're probably never going to +take stage manager class. You're just + + align:start position:0% +take stage manager class. You're just + + + align:start position:0% +take stage manager class. You're just +going to hand that prop once and then + + align:start position:0% +going to hand that prop once and then + + + align:start position:0% +going to hand that prop once and then +you're the prop master and then the + + align:start position:0% +you're the prop master and then the + + + align:start position:0% +you're the prop master and then the +stage manager gets sick and you do it + + align:start position:0% +stage manager gets sick and you do it + + + align:start position:0% +stage manager gets sick and you do it +for the night and then you're the stage + + align:start position:0% +for the night and then you're the stage + + + align:start position:0% +for the night and then you're the stage +manager. Yeah, I think theater has a ton + + align:start position:0% +manager. Yeah, I think theater has a ton + + + align:start position:0% +manager. Yeah, I think theater has a ton +of stuff like this. That's a great + + align:start position:0% +of stuff like this. That's a great + + + align:start position:0% +of stuff like this. That's a great +example. What are you going to say, + + align:start position:0% +example. What are you going to say, + + + align:start position:0% +example. What are you going to say, +Omar? In the tech and technique, we have + + align:start position:0% +Omar? In the tech and technique, we have + + + align:start position:0% +Omar? In the tech and technique, we have +what's called like shadowing. So, when + + align:start position:0% +what's called like shadowing. So, when + + + align:start position:0% +what's called like shadowing. So, when +we go out for photo assignments where + + align:start position:0% +we go out for photo assignments where + + + align:start position:0% +we go out for photo assignments where +there's a studio photography assignment + + align:start position:0% +there's a studio photography assignment + + + align:start position:0% +there's a studio photography assignment +or something out in the field, um we can + + align:start position:0% +or something out in the field, um we can + + + align:start position:0% +or something out in the field, um we can +always have like a someone shadowing us + + align:start position:0% +always have like a someone shadowing us + + + align:start position:0% +always have like a someone shadowing us +and they can also be taking photos with + + align:start position:0% +and they can also be taking photos with + + + align:start position:0% +and they can also be taking photos with +their own camera and sometimes we will + + align:start position:0% +their own camera and sometimes we will + + + align:start position:0% +their own camera and sometimes we will +use their work as well. So, they can + + align:start position:0% +use their work as well. So, they can + + + align:start position:0% +use their work as well. So, they can +also do legitimate periphery work. I + + align:start position:0% +also do legitimate periphery work. I + + + align:start position:0% +also do legitimate periphery work. I +love it. and you have intentionally sort + + align:start position:0% +love it. and you have intentionally sort + + + align:start position:0% +love it. and you have intentionally sort +of held space for that. You've kind of + + align:start position:0% +of held space for that. You've kind of + + + align:start position:0% +of held space for that. You've kind of +designed like, oh yeah, come, you know, + + align:start position:0% +designed like, oh yeah, come, you know, + + + align:start position:0% +designed like, oh yeah, come, you know, +come along, hang out with us. Um, and + + align:start position:0% +come along, hang out with us. Um, and + + + align:start position:0% +come along, hang out with us. Um, and +you probably have parties and other + + align:start position:0% +you probably have parties and other + + + align:start position:0% +you probably have parties and other +kinds of things like that where it's + + align:start position:0% +kinds of things like that where it's + + + align:start position:0% +kinds of things like that where it's +like, oh, you know, where like some of + + align:start position:0% +like, oh, you know, where like some of + + + align:start position:0% +like, oh, you know, where like some of +you are just goofing around, but some of + + align:start position:0% +you are just goofing around, but some of + + + align:start position:0% +you are just goofing around, but some of +it you're like, ah, the story that we + + align:start position:0% +it you're like, ah, the story that we + + + align:start position:0% +it you're like, ah, the story that we +gota d, you know, I'm sure like them + + align:start position:0% +gota d, you know, I'm sure like them + + + align:start position:0% +gota d, you know, I'm sure like them +telling the stories of of difficult + + align:start position:0% +telling the stories of of difficult + + + align:start position:0% +telling the stories of of difficult +cases and miraculous outcomes. I'm sure + + align:start position:0% +cases and miraculous outcomes. I'm sure + + + align:start position:0% +cases and miraculous outcomes. I'm sure +the tech has other similar kinds of + + align:start position:0% +the tech has other similar kinds of + + + align:start position:0% +the tech has other similar kinds of +difficult cases and miraculous outcomes. + + align:start position:0% +difficult cases and miraculous outcomes. + + + align:start position:0% +difficult cases and miraculous outcomes. +I was going to say like on sports teams + + align:start position:0% +I was going to say like on sports teams + + + align:start position:0% +I was going to say like on sports teams +like when people become captains like + + align:start position:0% +like when people become captains like + + + align:start position:0% +like when people become captains like +not often is the coach sitting them down + + align:start position:0% +not often is the coach sitting them down + + + align:start position:0% +not often is the coach sitting them down +and being like this is how you be a + + align:start position:0% +and being like this is how you be a + + + align:start position:0% +and being like this is how you be a +captain, this is how you lead people. + + align:start position:0% +captain, this is how you lead people. + + + align:start position:0% +captain, this is how you lead people. +It's more like they just like naturally + + align:start position:0% +It's more like they just like naturally + + + align:start position:0% +It's more like they just like naturally +have this like personality of doing that + + align:start position:0% +have this like personality of doing that + + + align:start position:0% +have this like personality of doing that +of like maybe they grew up and like + + align:start position:0% +of like maybe they grew up and like + + + align:start position:0% +of like maybe they grew up and like +their their mom was like a girl boss or + + align:start position:0% +their their mom was like a girl boss or + + + align:start position:0% +their their mom was like a girl boss or +like they like just grew up seeing stuff + + align:start position:0% +like they like just grew up seeing stuff + + + align:start position:0% +like they like just grew up seeing stuff +like that. So then like you kind of have + + align:start position:0% +like that. So then like you kind of have + + + align:start position:0% +like that. So then like you kind of have +like that natural progression into like + + align:start position:0% +like that natural progression into like + + + align:start position:0% +like that natural progression into like +just learning by doing. Good. Yeah. + + align:start position:0% +just learning by doing. Good. Yeah. + + + align:start position:0% +just learning by doing. Good. Yeah. +Yeah. Pretty. What were you going to + + align:start position:0% +Yeah. Pretty. What were you going to + + + align:start position:0% +Yeah. Pretty. What were you going to +say, Sabrina? Okay, this is kind of a + + align:start position:0% +say, Sabrina? Okay, this is kind of a + + + align:start position:0% +say, Sabrina? Okay, this is kind of a +dumb example, but I like I'm really bad + + align:start position:0% +dumb example, but I like I'm really bad + + + align:start position:0% +dumb example, but I like I'm really bad +at Smash, so I always get placed with + + align:start position:0% +at Smash, so I always get placed with + + + align:start position:0% +at Smash, so I always get placed with +the best Smash player, and then we're on + + align:start position:0% +the best Smash player, and then we're on + + + align:start position:0% +the best Smash player, and then we're on +a team against two other people who are + + align:start position:0% +a team against two other people who are + + + align:start position:0% +a team against two other people who are +also really good, but this person is so + + align:start position:0% +also really good, but this person is so + + + align:start position:0% +also really good, but this person is so +good that like they carry they carry, + + align:start position:0% +good that like they carry they carry, + + + align:start position:0% +good that like they carry they carry, +but I'm kind of learning along with + + align:start position:0% +but I'm kind of learning along with + + + align:start position:0% +but I'm kind of learning along with +them. Um, and like I kind of like hold + + align:start position:0% +them. Um, and like I kind of like hold + + + align:start position:0% +them. Um, and like I kind of like hold +off onto the side where I just kind of + + align:start position:0% +off onto the side where I just kind of + + + align:start position:0% +off onto the side where I just kind of +like try to like hold lives while they + + align:start position:0% +like try to like hold lives while they + + + align:start position:0% +like try to like hold lives while they +like destroy the other people. Um, and I + + align:start position:0% +like destroy the other people. Um, and I + + + align:start position:0% +like destroy the other people. Um, and I +think that's kind of periphery. Oh yeah, + + align:start position:0% +think that's kind of periphery. Oh yeah, + + + align:start position:0% +think that's kind of periphery. Oh yeah, +yeah, yeah, yeah. I mean in and in that + + align:start position:0% +yeah, yeah, yeah. I mean in and in that + + + align:start position:0% +yeah, yeah, yeah. I mean in and in that +particular community it's a space of + + align:start position:0% +particular community it's a space of + + + align:start position:0% +particular community it's a space of +legitimate peripheral participation + + align:start position:0% +legitimate peripheral participation + + + align:start position:0% +legitimate peripheral participation +which somewhat exists because of this + + align:start position:0% +which somewhat exists because of this + + + align:start position:0% +which somewhat exists because of this +like fairness balancing kinds of things + + align:start position:0% +like fairness balancing kinds of things + + + align:start position:0% +like fairness balancing kinds of things +and so you know like every learning + + align:start position:0% +and so you know like every learning + + + align:start position:0% +and so you know like every learning +environment like the substance of uh + + align:start position:0% +environment like the substance of uh + + + align:start position:0% +environment like the substance of uh +Super Smash Brothers determines like + + align:start position:0% +Super Smash Brothers determines like + + + align:start position:0% +Super Smash Brothers determines like +where the legitimate you know and it + + align:start position:0% +where the legitimate you know and it + + + align:start position:0% +where the legitimate you know and it +determines spaces for peripheral + + align:start position:0% +determines spaces for peripheral + + + align:start position:0% +determines spaces for peripheral +partition that's different than + + align:start position:0% +partition that's different than + + + align:start position:0% +partition that's different than +journalism that different than sports + + align:start position:0% +journalism that different than sports + + + align:start position:0% +journalism that different than sports +that different but this theory is giving + + align:start position:0% +that different but this theory is giving + + + align:start position:0% +that different but this theory is giving +us commonality where we can talk about + + align:start position:0% +us commonality where we can talk about + + + align:start position:0% +us commonality where we can talk about +really different things that might arise + + align:start position:0% +really different things that might arise + + + align:start position:0% +really different things that might arise +in different circumstances be like I I + + align:start position:0% +in different circumstances be like I I + + + align:start position:0% +in different circumstances be like I I +think that's actually kind of the same + + align:start position:0% +think that's actually kind of the same + + + align:start position:0% +think that's actually kind of the same +thing and it's kind of spaces that I'm + + align:start position:0% +thing and it's kind of spaces that I'm + + + align:start position:0% +thing and it's kind of spaces that I'm +finding for learning. + + align:start position:0% +finding for learning. + + + align:start position:0% +finding for learning. +Um, in short, when official channels + + align:start position:0% +Um, in short, when official channels + + + align:start position:0% +Um, in short, when official channels +offer only a possibility to participate + + align:start position:0% +offer only a possibility to participate + + + align:start position:0% +offer only a possibility to participate +in institutionally mandated forms of + + align:start position:0% +in institutionally mandated forms of + + + align:start position:0% +in institutionally mandated forms of +commoditized activity, genuine + + align:start position:0% +commoditized activity, genuine + + + align:start position:0% +commoditized activity, genuine +participation, membership, and + + align:start position:0% +participation, membership, and + + + align:start position:0% +participation, membership, and +legitimate access to ongoing practice of + + align:start position:0% +legitimate access to ongoing practice of + + + align:start position:0% +legitimate access to ongoing practice of +a practice considered worthy to the name + + align:start position:0% +a practice considered worthy to the name + + + align:start position:0% +a practice considered worthy to the name +are rare. Practice is not to be found in + + align:start position:0% +are rare. Practice is not to be found in + + + align:start position:0% +are rare. Practice is not to be found in +schools and workplaces. At the same + + align:start position:0% +schools and workplaces. At the same + + + align:start position:0% +schools and workplaces. At the same +time, schools and school-like workplace + + align:start position:0% +time, schools and school-like workplace + + + align:start position:0% +time, schools and school-like workplace +educational enterprises accord knowledge + + align:start position:0% +educational enterprises accord knowledge + + + align:start position:0% +educational enterprises accord knowledge +skill a reified existed turning it from + + align:start position:0% +skill a reified existed turning it from + + + align:start position:0% +skill a reified existed turning it from +into something to be acquired and its + + align:start position:0% +into something to be acquired and its + + + align:start position:0% +into something to be acquired and its +transmission into an institutional + + align:start position:0% +transmission into an institutional + + + align:start position:0% +transmission into an institutional +motive. This process generates pressures + + align:start position:0% +motive. This process generates pressures + + + align:start position:0% +motive. This process generates pressures +towards the trivializing decomposing of + + align:start position:0% +towards the trivializing decomposing of + + + align:start position:0% +towards the trivializing decomposing of +forms or activity. The result is a + + align:start position:0% +forms or activity. The result is a + + + align:start position:0% +forms or activity. The result is a +widespread generation of negative + + align:start position:0% +widespread generation of negative + + + align:start position:0% +widespread generation of negative +identities of misrecognized or + + align:start position:0% +identities of misrecognized or + + + align:start position:0% +identities of misrecognized or +institutionally disapproved insistential + + align:start position:0% +institutionally disapproved insistential + + + align:start position:0% +institutionally disapproved insistential +communities of practice. um that some of + + align:start position:0% +communities of practice. um that some of + + + align:start position:0% +communities of practice. um that some of +the things that might feel most academic + + align:start position:0% +the things that might feel most academic + + + align:start position:0% +the things that might feel most academic +might feel less or least identity + + align:start position:0% +might feel less or least identity + + + align:start position:0% +might feel less or least identity +oriented to you. Um because there's not, + + align:start position:0% +oriented to you. Um because there's not, + + + align:start position:0% +oriented to you. Um because there's not, +you know, think about like what like + + align:start position:0% +you know, think about like what like + + + align:start position:0% +you know, think about like what like +what degrees here would be like I'm not + + align:start position:0% +what degrees here would be like I'm not + + + align:start position:0% +what degrees here would be like I'm not +sure there's a way to be a legitimate + + align:start position:0% +sure there's a way to be a legitimate + + + align:start position:0% +sure there's a way to be a legitimate +peripheral participant there. Like + + align:start position:0% +peripheral participant there. Like + + + align:start position:0% +peripheral participant there. Like +there's a way to learn the stuff. + + align:start position:0% +there's a way to learn the stuff. + + + align:start position:0% +there's a way to learn the stuff. +There's a way to be taught the discreet + + align:start position:0% +There's a way to be taught the discreet + + + align:start position:0% +There's a way to be taught the discreet +parts of this course or subject or + + align:start position:0% +parts of this course or subject or + + + align:start position:0% +parts of this course or subject or +major, but I I like I'm not learning how + + align:start position:0% +major, but I I like I'm not learning how + + + align:start position:0% +major, but I I like I'm not learning how +to be a part of this community. Um + + align:start position:0% +to be a part of this community. Um + + + align:start position:0% +to be a part of this community. Um +uh okay. + + align:start position:0% +uh okay. + + + align:start position:0% +uh okay. +Um, here are three things that I'll have + + align:start position:0% +Um, here are three things that I'll have + + + align:start position:0% +Um, here are three things that I'll have +you do together um for five or 10 + + align:start position:0% +you do together um for five or 10 + + + align:start position:0% +you do together um for five or 10 +minutes, which might involve some + + align:start position:0% +minutes, which might involve some + + + align:start position:0% +minutes, which might involve some +drawing. Um, + + align:start position:0% +drawing. Um, + + + align:start position:0% +drawing. Um, +uh, so grab grab some paper or some + + align:start position:0% +uh, so grab grab some paper or some + + + align:start position:0% +uh, so grab grab some paper or some +board space. Um, what see if you could + + align:start position:0% +board space. Um, what see if you could + + + align:start position:0% +board space. Um, what see if you could +draw sort of the equivalent of human + + align:start position:0% +draw sort of the equivalent of human + + + align:start position:0% +draw sort of the equivalent of human +cognitive architecture. Um, see if you + + align:start position:0% +cognitive architecture. Um, see if you + + + align:start position:0% +cognitive architecture. Um, see if you +could draw like just just like just like + + align:start position:0% +could draw like just just like just like + + + align:start position:0% +could draw like just just like just like +you drew these diagrams for um, uh, + + align:start position:0% +you drew these diagrams for um, uh, + + + align:start position:0% +you drew these diagrams for um, uh, +cognitive load theory. What is the + + align:start position:0% +cognitive load theory. What is the + + + align:start position:0% +cognitive load theory. What is the +diagram you would draw for um situated + + align:start position:0% +diagram you would draw for um situated + + + align:start position:0% +diagram you would draw for um situated +learning? Um what is um based on that + + align:start position:0% +learning? Um what is um based on that + + + align:start position:0% +learning? Um what is um based on that +cognitive architecture? Um what is the + + align:start position:0% +cognitive architecture? Um what is the + + + align:start position:0% +cognitive architecture? Um what is the +pedagogy that follows? So based on like + + align:start position:0% +pedagogy that follows? So based on like + + + align:start position:0% +pedagogy that follows? So based on like +the sort of key fundamental principles + + align:start position:0% +the sort of key fundamental principles + + + align:start position:0% +the sort of key fundamental principles +of of situated learning, cognitive load + + align:start position:0% +of of situated learning, cognitive load + + + align:start position:0% +of of situated learning, cognitive load +theory said like here's a model of human + + align:start position:0% +theory said like here's a model of human + + + align:start position:0% +theory said like here's a model of human +cognitive architecture. Here are series + + align:start position:0% +cognitive architecture. Here are series + + + align:start position:0% +cognitive architecture. Here are series +of like clearly defined effects. The + + align:start position:0% +of like clearly defined effects. The + + + align:start position:0% +of like clearly defined effects. The +situated learning people are not as good + + align:start position:0% +situated learning people are not as good + + + align:start position:0% +situated learning people are not as good +as like enumerating in bullet points all + + align:start position:0% +as like enumerating in bullet points all + + + align:start position:0% +as like enumerating in bullet points all +of their pieces, but it's all in there. + + align:start position:0% +of their pieces, but it's all in there. + + + align:start position:0% +of their pieces, but it's all in there. +um what are some of the what are some of + + align:start position:0% +um what are some of the what are some of + + + align:start position:0% +um what are some of the what are some of +the like instructional practices that + + align:start position:0% +the like instructional practices that + + + align:start position:0% +the like instructional practices that +follow from this model? Um think about + + align:start position:0% +follow from this model? Um think about + + + align:start position:0% +follow from this model? Um think about +those two things and then also see if + + align:start position:0% +those two things and then also see if + + + align:start position:0% +those two things and then also see if +you can sort of recreate some of your + + align:start position:0% +you can sort of recreate some of your + + + align:start position:0% +you can sort of recreate some of your +ven diagrams um of what are the + + align:start position:0% +ven diagrams um of what are the + + + align:start position:0% +ven diagrams um of what are the +categories of things that seem separate + + align:start position:0% +categories of things that seem separate + + + align:start position:0% +categories of things that seem separate +from um cognitive learning and situated + + align:start position:0% +from um cognitive learning and situated + + + align:start position:0% +from um cognitive learning and situated +learning and what are the things that + + align:start position:0% +learning and what are the things that + + + align:start position:0% +learning and what are the things that +they seem to be quite similar on um or + + align:start position:0% +they seem to be quite similar on um or + + + align:start position:0% +they seem to be quite similar on um or +quite together on. Um take 10 minutes to + + align:start position:0% +quite together on. Um take 10 minutes to + + + align:start position:0% +quite together on. Um take 10 minutes to +again grab one person or two other + + align:start position:0% +again grab one person or two other + + + align:start position:0% +again grab one person or two other +people do some drawing, do some + + align:start position:0% +people do some drawing, do some + + + align:start position:0% +people do some drawing, do some +composing. Feel free to pull up your + + align:start position:0% +composing. Feel free to pull up your + + + align:start position:0% +composing. Feel free to pull up your +notes from your learning journal where + + align:start position:0% +notes from your learning journal where + + + align:start position:0% +notes from your learning journal where +you should have done some of this uh + + align:start position:0% +you should have done some of this uh + + + align:start position:0% +you should have done some of this uh +things. And if any of these questions, + + align:start position:0% +things. And if any of these questions, + + + align:start position:0% +things. And if any of these questions, +you don't have to you don't have to + + align:start position:0% +you don't have to you don't have to + + + align:start position:0% +you don't have to you don't have to +spend equal time on all three questions. + + align:start position:0% +spend equal time on all three questions. + + + align:start position:0% +spend equal time on all three questions. +If you dive in on one, that's fine. But + + align:start position:0% +If you dive in on one, that's fine. But + + + align:start position:0% +If you dive in on one, that's fine. But +those three should keep you busy for + + align:start position:0% +those three should keep you busy for + + + align:start position:0% +those three should keep you busy for +eight minutes or something like that. + + align:start position:0% +eight minutes or something like that. + + + align:start position:0% +eight minutes or something like that. +Make sense? Ready? You go. + + align:start position:0% +Make sense? Ready? You go. + + + align:start position:0% +Make sense? Ready? You go. +So, one one thing I love about almost + + align:start position:0% +So, one one thing I love about almost + + + align:start position:0% +So, one one thing I love about almost +all of these drawings is it's kind of + + align:start position:0% +all of these drawings is it's kind of + + + align:start position:0% +all of these drawings is it's kind of +impossible to draw these models without + + align:start position:0% +impossible to draw these models without + + + align:start position:0% +impossible to draw these models without +drawing other people. Um, that when you + + align:start position:0% +drawing other people. Um, that when you + + + align:start position:0% +drawing other people. Um, that when you +all developed a kind of human cognitive + + align:start position:0% +all developed a kind of human cognitive + + + align:start position:0% +all developed a kind of human cognitive +architecture in cognitive load theory, + + align:start position:0% +architecture in cognitive load theory, + + + align:start position:0% +architecture in cognitive load theory, +you were sort of drawing like one brain. + + align:start position:0% +you were sort of drawing like one brain. + + + align:start position:0% +you were sort of drawing like one brain. +And actually like actually most of your + + align:start position:0% +And actually like actually most of your + + + align:start position:0% +And actually like actually most of your +drawings you didn't even really + + align:start position:0% +drawings you didn't even really + + + align:start position:0% +drawings you didn't even really +represent the rest of the world. But in + + align:start position:0% +represent the rest of the world. But in + + + align:start position:0% +represent the rest of the world. But in +this model it's impossible not to + + align:start position:0% +this model it's impossible not to + + + align:start position:0% +this model it's impossible not to +represent the rest of the world and in + + align:start position:0% +represent the rest of the world and in + + + align:start position:0% +represent the rest of the world and in +particular other people um because + + align:start position:0% +particular other people um because + + + align:start position:0% +particular other people um because +learning fundamentally is social and + + align:start position:0% +learning fundamentally is social and + + + align:start position:0% +learning fundamentally is social and +your identity is fundamentally + + align:start position:0% +your identity is fundamentally + + + align:start position:0% +your identity is fundamentally +reflective of your connections with uh + + align:start position:0% +reflective of your connections with uh + + + align:start position:0% +reflective of your connections with uh +with other people. So these are good. Um + + align:start position:0% +with other people. So these are good. Um + + + align:start position:0% +with other people. So these are good. Um +you read a little piece of um give P's a + + align:start position:0% +you read a little piece of um give P's a + + + align:start position:0% +you read a little piece of um give P's a +chance. So four P's from Mitch Resnik + + align:start position:0% +chance. So four P's from Mitch Resnik + + + align:start position:0% +chance. So four P's from Mitch Resnik +about projects passion uh play and + + align:start position:0% +about projects passion uh play and + + + align:start position:0% +about projects passion uh play and +peers. Hopefully, you can now start + + align:start position:0% +peers. Hopefully, you can now start + + + align:start position:0% +peers. Hopefully, you can now start +mapping some of these ideas to what we + + align:start position:0% +mapping some of these ideas to what we + + + align:start position:0% +mapping some of these ideas to what we +talked about the reason, you know, + + align:start position:0% +talked about the reason, you know, + + + align:start position:0% +talked about the reason, you know, +projects, kind of open-ended + + align:start position:0% +projects, kind of open-ended + + + align:start position:0% +projects, kind of open-ended +explorations, making music, making uh + + align:start position:0% +explorations, making music, making uh + + + align:start position:0% +explorations, making music, making uh +funny shape, having a robot draw funny + + align:start position:0% +funny shape, having a robot draw funny + + + align:start position:0% +funny shape, having a robot draw funny +shape somewhere. Um, those are spaces + + align:start position:0% +shape somewhere. Um, those are spaces + + + align:start position:0% +shape somewhere. Um, those are spaces +for open-ended exploration, for doing + + align:start position:0% +for open-ended exploration, for doing + + + align:start position:0% +for open-ended exploration, for doing +multiple kinds of things. Um, projects + + align:start position:0% +multiple kinds of things. Um, projects + + + align:start position:0% +multiple kinds of things. Um, projects +have more space for peripheral + + align:start position:0% +have more space for peripheral + + + align:start position:0% +have more space for peripheral +participation, like multiple people can + + align:start position:0% +participation, like multiple people can + + + align:start position:0% +participation, like multiple people can +be making music, even if someone's a + + align:start position:0% +be making music, even if someone's a + + + align:start position:0% +be making music, even if someone's a +little bit better at making music than + + align:start position:0% +little bit better at making music than + + + align:start position:0% +little bit better at making music than +the other person. um that they are um + + align:start position:0% +the other person. um that they are um + + + align:start position:0% +the other person. um that they are um +that that learning environments here are + + align:start position:0% +that that learning environments here are + + + align:start position:0% +that that learning environments here are +are driven by interests. Um you know + + align:start position:0% +are driven by interests. Um you know + + + align:start position:0% +are driven by interests. Um you know +there's very little reference in + + align:start position:0% +there's very little reference in + + + align:start position:0% +there's very little reference in +cognitive load theory to things like + + align:start position:0% +cognitive load theory to things like + + + align:start position:0% +cognitive load theory to things like +well yeah and sometimes the kids don't + + align:start position:0% +well yeah and sometimes the kids don't + + + align:start position:0% +well yeah and sometimes the kids don't +like learning math so they just don't. + + align:start position:0% +like learning math so they just don't. + + + align:start position:0% +like learning math so they just don't. +Um although that's very real. Um some + + align:start position:0% +Um although that's very real. Um some + + + align:start position:0% +Um although that's very real. Um some +some of the young w some of the + + align:start position:0% +some of the young w some of the + + + align:start position:0% +some of the young w some of the +daughters and midwives wanted to become + + align:start position:0% +daughters and midwives wanted to become + + + align:start position:0% +daughters and midwives wanted to become +midwives and some didn't. Um and for the + + align:start position:0% +midwives and some didn't. Um and for the + + + align:start position:0% +midwives and some didn't. Um and for the +ones who did want to become midwives + + align:start position:0% +ones who did want to become midwives + + + align:start position:0% +ones who did want to become midwives +they followed that interest and those + + align:start position:0% +they followed that interest and those + + + align:start position:0% +they followed that interest and those +who didn't went and did other things. + + align:start position:0% +who didn't went and did other things. + + + align:start position:0% +who didn't went and did other things. +Um, and in these kinds of models of + + align:start position:0% +Um, and in these kinds of models of + + + align:start position:0% +Um, and in these kinds of models of +learning, that's actually okay and + + align:start position:0% +learning, that's actually okay and + + + align:start position:0% +learning, that's actually okay and +really important. We're not supposed to + + align:start position:0% +really important. We're not supposed to + + + align:start position:0% +really important. We're not supposed to +make everyone better at everything. + + align:start position:0% +make everyone better at everything. + + + align:start position:0% +make everyone better at everything. +We're supposed to let people follow + + align:start position:0% +We're supposed to let people follow + + + align:start position:0% +We're supposed to let people follow +their interests and get good at the + + align:start position:0% +their interests and get good at the + + + align:start position:0% +their interests and get good at the +things that they want to get good at. um + + align:start position:0% +things that they want to get good at. um + + + align:start position:0% +things that they want to get good at. um +that in environments in which there is a + + align:start position:0% +that in environments in which there is a + + + align:start position:0% +that in environments in which there is a +kind of lightness to the environment + + align:start position:0% +kind of lightness to the environment + + + align:start position:0% +kind of lightness to the environment +where uh you know lightness play creates + + align:start position:0% +where uh you know lightness play creates + + + align:start position:0% +where uh you know lightness play creates +space for multiple forms of + + align:start position:0% +space for multiple forms of + + + align:start position:0% +space for multiple forms of +participation like like things don't + + align:start position:0% +participation like like things don't + + + align:start position:0% +participation like like things don't +have to be optimized + + align:start position:0% +have to be optimized + + + align:start position:0% +have to be optimized +um to to get to the the you know fastest + + align:start position:0% +um to to get to the the you know fastest + + + align:start position:0% +um to to get to the the you know fastest +best trajectory for all people. There + + align:start position:0% +best trajectory for all people. There + + + align:start position:0% +best trajectory for all people. There +can be like room to to play and mess + + align:start position:0% +can be like room to to play and mess + + + align:start position:0% +can be like room to to play and mess +around and try other things. And then + + align:start position:0% +around and try other things. And then + + + align:start position:0% +around and try other things. And then +you know doing it with other people is + + align:start position:0% +you know doing it with other people is + + + align:start position:0% +you know doing it with other people is +essential as you can see in kind of all + + align:start position:0% +essential as you can see in kind of all + + + align:start position:0% +essential as you can see in kind of all +of these kinds of things you know and + + align:start position:0% +of these kinds of things you know and + + + align:start position:0% +of these kinds of things you know and +part of what uh um you know in some ways + + align:start position:0% +part of what uh um you know in some ways + + + align:start position:0% +part of what uh um you know in some ways +the real genius Jean Leave was a woman I + + align:start position:0% +the real genius Jean Leave was a woman I + + + align:start position:0% +the real genius Jean Leave was a woman I +misrepresented her as a man before and + + align:start position:0% +misrepresented her as a man before and + + + align:start position:0% +misrepresented her as a man before and +Aaron hopefully corrected me. Um Eddie + + align:start position:0% +Aaron hopefully corrected me. Um Eddie + + + align:start position:0% +Aaron hopefully corrected me. Um Eddie +Wanger her partner is a co-writer as a + + align:start position:0% +Wanger her partner is a co-writer as a + + + align:start position:0% +Wanger her partner is a co-writer as a +guy. Um is is it's not it's not just + + align:start position:0% +guy. Um is is it's not it's not just + + + align:start position:0% +guy. Um is is it's not it's not just +like people hanging out with each other. + + align:start position:0% +like people hanging out with each other. + + + align:start position:0% +like people hanging out with each other. +we can describe repeated patterns we see + + align:start position:0% +we can describe repeated patterns we see + + + align:start position:0% +we can describe repeated patterns we see +of legitimate peripheral participation + + align:start position:0% +of legitimate peripheral participation + + + align:start position:0% +of legitimate peripheral participation +um of old-timers and newcomers um of uh + + align:start position:0% +um of old-timers and newcomers um of uh + + + align:start position:0% +um of old-timers and newcomers um of uh +there's lots in Le's work that you + + align:start position:0% +there's lots in Le's work that you + + + align:start position:0% +there's lots in Le's work that you +probably read that was about trying to + + align:start position:0% +probably read that was about trying to + + + align:start position:0% +probably read that was about trying to +trying to find new language to get away + + align:start position:0% +trying to find new language to get away + + + align:start position:0% +trying to find new language to get away +from the experts and noviceses because + + align:start position:0% +from the experts and noviceses because + + + align:start position:0% +from the experts and noviceses because +it's not ju that's part of it but it's + + align:start position:0% +it's not ju that's part of it but it's + + + align:start position:0% +it's not ju that's part of it but it's +not just that um it's our time in its + + align:start position:0% +not just that um it's our time in its + + + align:start position:0% +not just that um it's our time in its +community it's our space in community + + align:start position:0% +community it's our space in community + + + align:start position:0% +community it's our space in community +those kinds of things so there's some so + + align:start position:0% +those kinds of things so there's some so + + + align:start position:0% +those kinds of things so there's some so +just like in cognitive load theory you + + align:start position:0% +just like in cognitive load theory you + + + align:start position:0% +just like in cognitive load theory you +could say here's a human cognitive + + align:start position:0% +could say here's a human cognitive + + + align:start position:0% +could say here's a human cognitive +architecture here's a set of pedagogical + + align:start position:0% +architecture here's a set of pedagogical + + + align:start position:0% +architecture here's a set of pedagogical +principles that follow from that. Um, + + align:start position:0% +principles that follow from that. Um, + + + align:start position:0% +principles that follow from that. Um, +Jean Leave can describe these social + + align:start position:0% +Jean Leave can describe these social + + + align:start position:0% +Jean Leave can describe these social +interactions. We can as you can abstract + + align:start position:0% +interactions. We can as you can abstract + + + align:start position:0% +interactions. We can as you can abstract +from them some models of uh of human + + align:start position:0% +from them some models of uh of human + + + align:start position:0% +from them some models of uh of human +cognitive architecture and say well okay + + align:start position:0% +cognitive architecture and say well okay + + + align:start position:0% +cognitive architecture and say well okay +from those models there are some + + align:start position:0% +from those models there are some + + + align:start position:0% +from those models there are some +instructional principles that follow. Um + + align:start position:0% +instructional principles that follow. Um + + + align:start position:0% +instructional principles that follow. Um +if I were to draw one of these I think a + + align:start position:0% +if I were to draw one of these I think a + + + align:start position:0% +if I were to draw one of these I think a +thing that I would pay a bunch of + + align:start position:0% +thing that I would pay a bunch of + + + align:start position:0% +thing that I would pay a bunch of +attention to is that um you know the + + align:start position:0% +attention to is that um you know the + + + align:start position:0% +attention to is that um you know the +thing in in both learning models like + + align:start position:0% +thing in in both learning models like + + + align:start position:0% +thing in in both learning models like +you learn what you attend to. Um seeing + + align:start position:0% +you learn what you attend to. Um seeing + + + align:start position:0% +you learn what you attend to. Um seeing +is really important. Um, a key insight + + align:start position:0% +is really important. Um, a key insight + + + align:start position:0% +is really important. Um, a key insight +of of uh situated learning is that we + + align:start position:0% +of of uh situated learning is that we + + + align:start position:0% +of of uh situated learning is that we +attend to things that interest us and + + align:start position:0% +attend to things that interest us and + + + align:start position:0% +attend to things that interest us and +motivate us and where where we find our + + align:start position:0% +motivate us and where where we find our + + + align:start position:0% +motivate us and where where we find our +identity and care about like how you + + align:start position:0% +identity and care about like how you + + + align:start position:0% +identity and care about like how you +know if looking at something is + + align:start position:0% +know if looking at something is + + + align:start position:0% +know if looking at something is +essential to get people to learn about + + align:start position:0% +essential to get people to learn about + + + align:start position:0% +essential to get people to learn about +it then we ought to think very carefully + + align:start position:0% +it then we ought to think very carefully + + + align:start position:0% +it then we ought to think very carefully +about what motivates us to look at a + + align:start position:0% +about what motivates us to look at a + + + align:start position:0% +about what motivates us to look at a +thing. Um, uh, T-ball for me is a, + + align:start position:0% +thing. Um, uh, T-ball for me is a, + + + align:start position:0% +thing. Um, uh, T-ball for me is a, +um, a a a canonical example of a kind of + + align:start position:0% +um, a a a canonical example of a kind of + + + align:start position:0% +um, a a a canonical example of a kind of +activity which it would be almost + + align:start position:0% +activity which it would be almost + + + align:start position:0% +activity which it would be almost +impossible to teach primarily through + + align:start position:0% +impossible to teach primarily through + + + align:start position:0% +impossible to teach primarily through +cognitive load theory. Um, like it's + + align:start position:0% +cognitive load theory. Um, like it's + + + align:start position:0% +cognitive load theory. Um, like it's +really hard to imagine teaching kids + + align:start position:0% +really hard to imagine teaching kids + + + align:start position:0% +really hard to imagine teaching kids +baseball where you're like, "All right, + + align:start position:0% +baseball where you're like, "All right, + + + align:start position:0% +baseball where you're like, "All right, +sit down everyone. Like we're all going + + align:start position:0% +sit down everyone. Like we're all going + + + align:start position:0% +sit down everyone. Like we're all going +to watch a worked example of how you, + + align:start position:0% +to watch a worked example of how you, + + + align:start position:0% +to watch a worked example of how you, +you know, hit a ball or like like we + + align:start position:0% +you know, hit a ball or like like we + + + align:start position:0% +you know, hit a ball or like like we +have to learn the rule book of + + align:start position:0% +have to learn the rule book of + + + align:start position:0% +have to learn the rule book of +baseball." Like the way we teach kids + + align:start position:0% +baseball." Like the way we teach kids + + + align:start position:0% +baseball." Like the way we teach kids +baseball is we're like, "What is the + + align:start position:0% +baseball is we're like, "What is the + + + align:start position:0% +baseball is we're like, "What is the +fastest way we can get young people with + + align:start position:0% +fastest way we can get young people with + + + align:start position:0% +fastest way we can get young people with +limited coordination and no knowledge of + + align:start position:0% +limited coordination and no knowledge of + + + align:start position:0% +limited coordination and no knowledge of +the rules to play something like + + align:start position:0% +the rules to play something like + + + align:start position:0% +the rules to play something like +baseball? How do we get them baseballing + + align:start position:0% +baseball? How do we get them baseballing + + + align:start position:0% +baseball? How do we get them baseballing +as soon as we possibly can?" And some + + align:start position:0% +as soon as we possibly can?" And some + + + align:start position:0% +as soon as we possibly can?" And some +genius was like, "Don't do the pitching. + + align:start position:0% +genius was like, "Don't do the pitching. + + + align:start position:0% +genius was like, "Don't do the pitching. +Like, get rid of the pitching. Just put + + align:start position:0% +Like, get rid of the pitching. Just put + + + align:start position:0% +Like, get rid of the pitching. Just put +the ball on the stick and they can just + + align:start position:0% +the ball on the stick and they can just + + + align:start position:0% +the ball on the stick and they can just +hit the ball." Um, it h it it it has + + align:start position:0% +hit the ball." Um, it h it it it has + + + align:start position:0% +hit the ball." Um, it h it it it has +some kind of cognitive relationship to + + align:start position:0% +some kind of cognitive relationship to + + + align:start position:0% +some kind of cognitive relationship to +sort of part whole practice um to + + align:start position:0% +sort of part whole practice um to + + + align:start position:0% +sort of part whole practice um to +devolving scaffolding and things like + + align:start position:0% +devolving scaffolding and things like + + + align:start position:0% +devolving scaffolding and things like +that. There's a there's a researcher at + + align:start position:0% +that. There's a there's a researcher at + + + align:start position:0% +that. There's a there's a researcher at +Harvard uh who wrote a book called + + align:start position:0% +Harvard uh who wrote a book called + + + align:start position:0% +Harvard uh who wrote a book called +Making Learning Whole. Um where he said + + align:start position:0% +Making Learning Whole. Um where he said + + + align:start position:0% +Making Learning Whole. Um where he said +that that one of the things we can often + + align:start position:0% +that that one of the things we can often + + + align:start position:0% +that that one of the things we can often +do in curriculum that we underestimate + + align:start position:0% +do in curriculum that we underestimate + + + align:start position:0% +do in curriculum that we underestimate +is get people playing the whole game as + + align:start position:0% +is get people playing the whole game as + + + align:start position:0% +is get people playing the whole game as +early as possible. Um you could we'll + + align:start position:0% +early as possible. Um you could we'll + + + align:start position:0% +early as possible. Um you could we'll +talk about this more, but think about + + align:start position:0% +talk about this more, but think about + + + align:start position:0% +talk about this more, but think about +like what subjects have you taken in MIT + + align:start position:0% +like what subjects have you taken in MIT + + + align:start position:0% +like what subjects have you taken in MIT +that let you start playing the whole + + align:start position:0% +that let you start playing the whole + + + align:start position:0% +that let you start playing the whole +game as soon as possible and what + + align:start position:0% +game as soon as possible and what + + + align:start position:0% +game as soon as possible and what +require you to sort of build up lots of + + align:start position:0% +require you to sort of build up lots of + + + align:start position:0% +require you to sort of build up lots of +elementary pieces before you can do the + + align:start position:0% +elementary pieces before you can do the + + + align:start position:0% +elementary pieces before you can do the +thing that that whole discipline does. + + align:start position:0% +thing that that whole discipline does. + + + align:start position:0% +thing that that whole discipline does. +Um but ba baseball instruction in the + + align:start position:0% +Um but ba baseball instruction in the + + + align:start position:0% +Um but ba baseball instruction in the +United States like very difficult to + + align:start position:0% +United States like very difficult to + + + align:start position:0% +United States like very difficult to +imagine in a cognitive load theory + + align:start position:0% +imagine in a cognitive load theory + + + align:start position:0% +imagine in a cognitive load theory +framework. Um like very pleasant for + + align:start position:0% +framework. Um like very pleasant for + + + align:start position:0% +framework. Um like very pleasant for +millions of young people in a more + + align:start position:0% +millions of young people in a more + + + align:start position:0% +millions of young people in a more +experiential situated kind of way. All + + align:start position:0% +experiential situated kind of way. All + + + align:start position:0% +experiential situated kind of way. All +right. You did this a little bit. Um + + align:start position:0% +right. You did this a little bit. Um + + + align:start position:0% +right. You did this a little bit. Um +which is good. Here is one thing that I + + align:start position:0% +which is good. Here is one thing that I + + + align:start position:0% +which is good. Here is one thing that I +would like to have in the center of your + + align:start position:0% +would like to have in the center of your + + + align:start position:0% +would like to have in the center of your +ven diagrams of things that are similar. + + align:start position:0% +ven diagrams of things that are similar. + + + align:start position:0% +ven diagrams of things that are similar. +Um this I this is a misconception that + + align:start position:0% +Um this I this is a misconception that + + + align:start position:0% +Um this I this is a misconception that +my students have had over the years that + + align:start position:0% +my students have had over the years that + + + align:start position:0% +my students have had over the years that +I want to correct. + + align:start position:0% +I want to correct. + + + align:start position:0% +I want to correct. +um + + align:start position:0% +um + + + align:start position:0% +um +they're the cognitive loads theorists + + align:start position:0% +they're the cognitive loads theorists + + + align:start position:0% +they're the cognitive loads theorists +and the situated learning people agree + + align:start position:0% +and the situated learning people agree + + + align:start position:0% +and the situated learning people agree +on what expertise looks like. They agree + + align:start position:0% +on what expertise looks like. They agree + + + align:start position:0% +on what expertise looks like. They agree +on what high quality practice looks + + align:start position:0% +on what high quality practice looks + + + align:start position:0% +on what high quality practice looks +like. I don't think you'd find these + + align:start position:0% +like. I don't think you'd find these + + + align:start position:0% +like. I don't think you'd find these +people. They would not disagree about + + align:start position:0% +people. They would not disagree about + + + align:start position:0% +people. They would not disagree about +what a great body player or a great + + align:start position:0% +what a great body player or a great + + + align:start position:0% +what a great body player or a great +carpenter or a great surgeon or a great + + align:start position:0% +carpenter or a great surgeon or a great + + + align:start position:0% +carpenter or a great surgeon or a great +lawyer looks like. Um they would believe + + align:start position:0% +lawyer looks like. Um they would believe + + + align:start position:0% +lawyer looks like. Um they would believe +that sometimes people think that the + + align:start position:0% +that sometimes people think that the + + + align:start position:0% +that sometimes people think that the +cognitive load theorists want people who + + align:start position:0% +cognitive load theorists want people who + + + align:start position:0% +cognitive load theorists want people who +are experts to be really like rigid and + + align:start position:0% +are experts to be really like rigid and + + + align:start position:0% +are experts to be really like rigid and +disciplined and pattern repeating and + + align:start position:0% +disciplined and pattern repeating and + + + align:start position:0% +disciplined and pattern repeating and +that is not the case. That is not what + + align:start position:0% +that is not the case. That is not what + + + align:start position:0% +that is not the case. That is not what +they want as the end point. You know + + align:start position:0% +they want as the end point. You know + + + align:start position:0% +they want as the end point. You know +they they want your cancer surgeon to be + + align:start position:0% +they they want your cancer surgeon to be + + + align:start position:0% +they they want your cancer surgeon to be +dynamic and flexible when they cut open + + align:start position:0% +dynamic and flexible when they cut open + + + align:start position:0% +dynamic and flexible when they cut open +your belly um and find cancerous tumors + + align:start position:0% +your belly um and find cancerous tumors + + + align:start position:0% +your belly um and find cancerous tumors +and are pulling them out of there. Um + + align:start position:0% +and are pulling them out of there. Um + + + align:start position:0% +and are pulling them out of there. Um +they want poets to be creative and + + align:start position:0% +they want poets to be creative and + + + align:start position:0% +they want poets to be creative and +imaginative. They just think that the + + align:start position:0% +imaginative. They just think that the + + + align:start position:0% +imaginative. They just think that the +way that you develop the knowledge base + + align:start position:0% +way that you develop the knowledge base + + + align:start position:0% +way that you develop the knowledge base +that lets you be creative and flexible + + align:start position:0% +that lets you be creative and flexible + + + align:start position:0% +that lets you be creative and flexible +and dynamic and strategic is through + + align:start position:0% +and dynamic and strategic is through + + + align:start position:0% +and dynamic and strategic is through +really disciplined instruction. Um + + align:start position:0% +really disciplined instruction. Um + + + align:start position:0% +really disciplined instruction. Um +because if you don't go through a + + align:start position:0% +because if you don't go through a + + + align:start position:0% +because if you don't go through a +process of really disciplined + + align:start position:0% +process of really disciplined + + + align:start position:0% +process of really disciplined +instruction, um it's hard to get good at + + align:start position:0% +instruction, um it's hard to get good at + + + align:start position:0% +instruction, um it's hard to get good at +things because no one no one has showed + + align:start position:0% +things because no one no one has showed + + + align:start position:0% +things because no one no one has showed +you how to do fundamental pieces um in + + align:start position:0% +you how to do fundamental pieces um in + + + align:start position:0% +you how to do fundamental pieces um in +clear ways. Um I have a couple + + align:start position:0% +clear ways. Um I have a couple + + + align:start position:0% +clear ways. Um I have a couple +colleagues, Jal Meta and Sarah Fine. Um + + align:start position:0% +colleagues, Jal Meta and Sarah Fine. Um + + + align:start position:0% +colleagues, Jal Meta and Sarah Fine. Um +J still at Harvard. uh s was there for a + + align:start position:0% +J still at Harvard. uh s was there for a + + + align:start position:0% +J still at Harvard. uh s was there for a +while in his uh was it high-tech high + + align:start position:0% +while in his uh was it high-tech high + + + align:start position:0% +while in his uh was it high-tech high +graduate school of education for a while + + align:start position:0% +graduate school of education for a while + + + align:start position:0% +graduate school of education for a while +who said who studied schools a lot + + align:start position:0% +who said who studied schools a lot + + + align:start position:0% +who said who studied schools a lot +studied very different schools with very + + align:start position:0% +studied very different schools with very + + + align:start position:0% +studied very different schools with very +different pedagogical philosophies and + + align:start position:0% +different pedagogical philosophies and + + + align:start position:0% +different pedagogical philosophies and +found that across all of them they + + align:start position:0% +found that across all of them they + + + align:start position:0% +found that across all of them they +tended to believe that expertise + + align:start position:0% +tended to believe that expertise + + + align:start position:0% +tended to believe that expertise +consisted of mastery identity and + + align:start position:0% +consisted of mastery identity and + + + align:start position:0% +consisted of mastery identity and +creativity that you knew a bunch of + + align:start position:0% +creativity that you knew a bunch of + + + align:start position:0% +creativity that you knew a bunch of +stuff in a domain um that you developed + + align:start position:0% +stuff in a domain um that you developed + + + align:start position:0% +stuff in a domain um that you developed +an identity in that domain and that you + + align:start position:0% +an identity in that domain and that you + + + align:start position:0% +an identity in that domain and that you +were able to do flexible creative work + + align:start position:0% +were able to do flexible creative work + + + align:start position:0% +were able to do flexible creative work +um you know a bunch of physics equations + + align:start position:0% +um you know a bunch of physics equations + + + align:start position:0% +um you know a bunch of physics equations +and when to apply them you feel like + + align:start position:0% +and when to apply them you feel like + + + align:start position:0% +and when to apply them you feel like +you're kind of a physicist and a + + align:start position:0% +you're kind of a physicist and a + + + align:start position:0% +you're kind of a physicist and a +scientist and when you need to do + + align:start position:0% +scientist and when you need to do + + + align:start position:0% +scientist and when you need to do +something novel like build a bridge um + + align:start position:0% +something novel like build a bridge um + + + align:start position:0% +something novel like build a bridge um +or launch a rocket or something like + + align:start position:0% +or launch a rocket or something like + + + align:start position:0% +or launch a rocket or something like +that, you're not just following steps, + + align:start position:0% +that, you're not just following steps, + + + align:start position:0% +that, you're not just following steps, +but you're doing things that are that + + align:start position:0% +but you're doing things that are that + + + align:start position:0% +but you're doing things that are that +are creative um and expressive. One one + + align:start position:0% +are creative um and expressive. One one + + + align:start position:0% +are creative um and expressive. One one +way that I would um I think the + + align:start position:0% +way that I would um I think the + + + align:start position:0% +way that I would um I think the +cognitive load theorists and situated + + align:start position:0% +cognitive load theorists and situated + + + align:start position:0% +cognitive load theorists and situated +learning people tend to imagine + + align:start position:0% +learning people tend to imagine + + + align:start position:0% +learning people tend to imagine +different pathways at getting at these + + align:start position:0% +different pathways at getting at these + + + align:start position:0% +different pathways at getting at these +goals. Um, so the cognitive load + + align:start position:0% +goals. Um, so the cognitive load + + + align:start position:0% +goals. Um, so the cognitive load +theorists tend to think that mastery is + + align:start position:0% +theorists tend to think that mastery is + + + align:start position:0% +theorists tend to think that mastery is +like the starting point. If you know the + + align:start position:0% +like the starting point. If you know the + + + align:start position:0% +like the starting point. If you know the +stuff, if you can do the pieces, then a + + align:start position:0% +stuff, if you can do the pieces, then a + + + align:start position:0% +stuff, if you can do the pieces, then a +we often most enjoy things that we're + + align:start position:0% +we often most enjoy things that we're + + + align:start position:0% +we often most enjoy things that we're +good at. So like get you good at doing + + align:start position:0% +good at. So like get you good at doing + + + align:start position:0% +good at. So like get you good at doing +things. There's, you know, there's there + + align:start position:0% +things. There's, you know, there's there + + + align:start position:0% +things. There's, you know, there's there +there's there's lots of debates in the + + align:start position:0% +there's there's lots of debates in the + + + align:start position:0% +there's there's lots of debates in the +country right now, we'll talk about them + + align:start position:0% +country right now, we'll talk about them + + + align:start position:0% +country right now, we'll talk about them +some, about teaching kids to read. Um, + + align:start position:0% +some, about teaching kids to read. Um, + + + align:start position:0% +some, about teaching kids to read. Um, +and there's some folks who say like we + + align:start position:0% +and there's some folks who say like we + + + align:start position:0% +and there's some folks who say like we +just have to let kids explore books and + + align:start position:0% +just have to let kids explore books and + + + align:start position:0% +just have to let kids explore books and +find what they're interested in. And + + align:start position:0% +find what they're interested in. And + + + align:start position:0% +find what they're interested in. And +there other folks are like, you know + + align:start position:0% +there other folks are like, you know + + + align:start position:0% +there other folks are like, you know +what's fun about reading is actually + + align:start position:0% +what's fun about reading is actually + + + align:start position:0% +what's fun about reading is actually +being able to read. So like teach them a + + align:start position:0% +being able to read. So like teach them a + + + align:start position:0% +being able to read. So like teach them a +bunch of phonics and explain to them the + + align:start position:0% +bunch of phonics and explain to them the + + + align:start position:0% +bunch of phonics and explain to them the +basics of how to construct words. And + + align:start position:0% +basics of how to construct words. And + + + align:start position:0% +basics of how to construct words. And +that's what makes reading enjoyable. + + align:start position:0% +that's what makes reading enjoyable. + + + align:start position:0% +that's what makes reading enjoyable. +That would make people feel like + + align:start position:0% +That would make people feel like + + + align:start position:0% +That would make people feel like +readers, you know, not when they have + + align:start position:0% +readers, you know, not when they have + + + align:start position:0% +readers, you know, not when they have +like a beautiful library of things to + + align:start position:0% +like a beautiful library of things to + + + align:start position:0% +like a beautiful library of things to +choose from, whatever they want, but + + align:start position:0% +choose from, whatever they want, but + + + align:start position:0% +choose from, whatever they want, but +when they can actually make sense of + + align:start position:0% +when they can actually make sense of + + + align:start position:0% +when they can actually make sense of +what's in there. There's some sense in + + align:start position:0% +what's in there. There's some sense in + + + align:start position:0% +what's in there. There's some sense in +that. Um, you develop some kind of + + align:start position:0% +that. Um, you develop some kind of + + + align:start position:0% +that. Um, you develop some kind of +identity and then you get then you have + + align:start position:0% +identity and then you get then you have + + + align:start position:0% +identity and then you get then you have +the opportunity to do creative practice + + align:start position:0% +the opportunity to do creative practice + + + align:start position:0% +the opportunity to do creative practice +that builds that mastery. There are + + align:start position:0% +that builds that mastery. There are + + + align:start position:0% +that builds that mastery. There are +other people who say start with things + + align:start position:0% +other people who say start with things + + + align:start position:0% +other people who say start with things +like creativity. Start by getting people + + align:start position:0% +like creativity. Start by getting people + + + align:start position:0% +like creativity. Start by getting people +to play around in the space as much as + + align:start position:0% +to play around in the space as much as + + + align:start position:0% +to play around in the space as much as +possible so that they're motivated. Um + + align:start position:0% +possible so that they're motivated. Um + + + align:start position:0% +possible so that they're motivated. Um +so that they say, "Man, like I am a I am + + align:start position:0% +so that they say, "Man, like I am a I am + + + align:start position:0% +so that they say, "Man, like I am a I am +a this. I want, you know, I'm a I'm a + + align:start position:0% +a this. I want, you know, I'm a I'm a + + + align:start position:0% +a this. I want, you know, I'm a I'm a +baseball player. Like I, you know, I + + align:start position:0% +baseball player. Like I, you know, I + + + align:start position:0% +baseball player. Like I, you know, I +swung on a ball on a stick a few times." + + align:start position:0% +swung on a ball on a stick a few times." + + + align:start position:0% +swung on a ball on a stick a few times." +Um but now I am a baseball player. Um, + + align:start position:0% +Um but now I am a baseball player. Um, + + + align:start position:0% +Um but now I am a baseball player. Um, +and because I'm a baseball player, like + + align:start position:0% +and because I'm a baseball player, like + + + align:start position:0% +and because I'm a baseball player, like +in my heart, um, I'll memorize all the + + align:start position:0% +in my heart, um, I'll memorize all the + + + align:start position:0% +in my heart, um, I'll memorize all the +statistics and learn the rules and go to + + align:start position:0% +statistics and learn the rules and go to + + + align:start position:0% +statistics and learn the rules and go to +practice, you know, and eventually do + + align:start position:0% +practice, you know, and eventually do + + + align:start position:0% +practice, you know, and eventually do +like really boring learning kinds of + + align:start position:0% +like really boring learning kinds of + + + align:start position:0% +like really boring learning kinds of +things. Um, the sort of masteryoriented + + align:start position:0% +things. Um, the sort of masteryoriented + + + align:start position:0% +things. Um, the sort of masteryoriented +discipline kinds of things, but because + + align:start position:0% +discipline kinds of things, but because + + + align:start position:0% +discipline kinds of things, but because +I know how fun it is to play around in + + align:start position:0% +I know how fun it is to play around in + + + align:start position:0% +I know how fun it is to play around in +this space. Um, what what do you think + + align:start position:0% +this space. Um, what what do you think + + + align:start position:0% +this space. Um, what what do you think +at MIT are the are the subjects or + + align:start position:0% +at MIT are the are the subjects or + + + align:start position:0% +at MIT are the are the subjects or +courses that you would take that would + + align:start position:0% +courses that you would take that would + + + align:start position:0% +courses that you would take that would +be more canonically sort of mastery + + align:start position:0% +be more canonically sort of mastery + + + align:start position:0% +be more canonically sort of mastery +first oriented? + + align:start position:0% +first oriented? + + + align:start position:0% +first oriented? +What are what are the subjects you would + + align:start position:0% +What are what are the subjects you would + + + align:start position:0% +What are what are the subjects you would +take that you would like start with the + + align:start position:0% +take that you would like start with the + + + align:start position:0% +take that you would like start with the +smallest pieces or or by contrast if + + align:start position:0% +smallest pieces or or by contrast if + + + align:start position:0% +smallest pieces or or by contrast if +it's easier? What are the ones that seem + + align:start position:0% +it's easier? What are the ones that seem + + + align:start position:0% +it's easier? What are the ones that seem +to be more creativity first? + + align:start position:0% + + + + align:start position:0% + +I think more like bioheavy classes would + + align:start position:0% +I think more like bioheavy classes would + + + align:start position:0% +I think more like bioheavy classes would +definitely be like mastery first because + + align:start position:0% +definitely be like mastery first because + + + align:start position:0% +definitely be like mastery first because +if you don't understand like the basic + + align:start position:0% +if you don't understand like the basic + + + align:start position:0% +if you don't understand like the basic +of cells like you're not getting + + align:start position:0% +of cells like you're not getting + + + align:start position:0% +of cells like you're not getting +anywhere like you can't go like chapter + + align:start position:0% +anywhere like you can't go like chapter + + + align:start position:0% +anywhere like you can't go like chapter +2 without understanding like good. So it + + align:start position:0% +2 without understanding like good. So it + + + align:start position:0% +2 without understanding like good. So it +seems to be, you know, so eventually you + + align:start position:0% +seems to be, you know, so eventually you + + + align:start position:0% +seems to be, you know, so eventually you +can do some like pretty rad + + align:start position:0% +can do some like pretty rad + + + align:start position:0% +can do some like pretty rad +computational biology, biological + + align:start position:0% +computational biology, biological + + + align:start position:0% +computational biology, biological +engineering here, but there's not a lot + + align:start position:0% +engineering here, but there's not a lot + + + align:start position:0% +engineering here, but there's not a lot +in bio 101 where they're like, "Yeah, + + align:start position:0% +in bio 101 where they're like, "Yeah, + + + align:start position:0% +in bio 101 where they're like, "Yeah, +let's like have cells start generating + + align:start position:0% +let's like have cells start generating + + + align:start position:0% +let's like have cells start generating +novel proteins or things like that." I + + align:start position:0% +novel proteins or things like that." I + + + align:start position:0% +novel proteins or things like that." I +would say most of the general + + align:start position:0% +would say most of the general + + + align:start position:0% +would say most of the general +requirements like especially like the + + align:start position:0% +requirements like especially like the + + + align:start position:0% +requirements like especially like the +chemistry requirements and the biology + + align:start position:0% +chemistry requirements and the biology + + + align:start position:0% +chemistry requirements and the biology +requirements are like with the hopes + + align:start position:0% +requirements are like with the hopes + + + align:start position:0% +requirements are like with the hopes +that hey if you learn a little bit about + + align:start position:0% +that hey if you learn a little bit about + + + align:start position:0% +that hey if you learn a little bit about +this maybe then you become interested + + align:start position:0% +this maybe then you become interested + + + align:start position:0% +this maybe then you become interested +and want to go further and want that to + + align:start position:0% +and want to go further and want that to + + + align:start position:0% +and want to go further and want that to +be your major. But yeah, so so which + + align:start position:0% +be your major. But yeah, so so which + + + align:start position:0% +be your major. But yeah, so so which +which ones do that through like giving + + align:start position:0% +which ones do that through like giving + + + align:start position:0% +which ones do that through like giving +you a bunch of facts and which ones do + + align:start position:0% +you a bunch of facts and which ones do + + + align:start position:0% +you a bunch of facts and which ones do +that by letting you sort of play the + + align:start position:0% +that by letting you sort of play the + + + align:start position:0% +that by letting you sort of play the +whole + + align:start position:0% + + + + align:start position:0% + +game? I mean my understanding is that a + + align:start position:0% +game? I mean my understanding is that a + + + align:start position:0% +game? I mean my understanding is that a +number of the engineering departments + + align:start position:0% +number of the engineering departments + + + align:start position:0% +number of the engineering departments +like in mechanical engineering you'd be + + align:start position:0% +like in mechanical engineering you'd be + + + align:start position:0% +like in mechanical engineering you'd be +more likely earlier in your career to be + + align:start position:0% +more likely earlier in your career to be + + + align:start position:0% +more likely earlier in your career to be +like we're going to build a robot. Um + + align:start position:0% +like we're going to build a robot. Um + + + align:start position:0% +like we're going to build a robot. Um +and like do you know how to build a + + align:start position:0% +and like do you know how to build a + + + align:start position:0% +and like do you know how to build a +robot? No. Are you going to be good at + + align:start position:0% +robot? No. Are you going to be good at + + + align:start position:0% +robot? No. Are you going to be good at +building a robot? No. You're going to + + align:start position:0% +building a robot? No. You're going to + + + align:start position:0% +building a robot? No. You're going to +build a lousy robot. We're going to let + + align:start position:0% +build a lousy robot. We're going to let + + + align:start position:0% +build a lousy robot. We're going to let +you build a crummy robot. and some TA is + + align:start position:0% +you build a crummy robot. and some TA is + + + align:start position:0% +you build a crummy robot. and some TA is +going to put their arm around your + + align:start position:0% +going to put their arm around your + + + align:start position:0% +going to put their arm around your +shoulder and be like, "That robot's + + align:start position:0% +shoulder and be like, "That robot's + + + align:start position:0% +shoulder and be like, "That robot's +okay. That robot's only okay because you + + align:start position:0% +okay. That robot's only okay because you + + + align:start position:0% +okay. That robot's only okay because you +don't know anything about control + + align:start position:0% +don't know anything about control + + + align:start position:0% +don't know anything about control +systems." But guess what? Guess what? + + align:start position:0% +systems." But guess what? Guess what? + + + align:start position:0% +systems." But guess what? Guess what? +One of our junior classes is control + + align:start position:0% +One of our junior classes is control + + + align:start position:0% +One of our junior classes is control +systems. You're like, "Ah, I can't wait + + align:start position:0% +systems. You're like, "Ah, I can't wait + + + align:start position:0% +systems. You're like, "Ah, I can't wait +to take control system. It's going to be + + align:start position:0% +to take control system. It's going to be + + + align:start position:0% +to take control system. It's going to be +boring. It's going to be like a bunch of + + align:start position:0% +boring. It's going to be like a bunch of + + + align:start position:0% +boring. It's going to be like a bunch of +equations and other pets and things like + + align:start position:0% +equations and other pets and things like + + + align:start position:0% +equations and other pets and things like +that." But there's a robot that you want + + align:start position:0% +that." But there's a robot that you want + + + align:start position:0% +that." But there's a robot that you want +to drive. Um, the neat program I think + + align:start position:0% +to drive. Um, the neat program I think + + + align:start position:0% +to drive. Um, the neat program I think +at MIT is really about trying to create + + align:start position:0% +at MIT is really about trying to create + + + align:start position:0% +at MIT is really about trying to create +a bunch of these like experiential + + align:start position:0% +a bunch of these like experiential + + + align:start position:0% +a bunch of these like experiential +experiences. I mean, historically, if + + align:start position:0% +experiences. I mean, historically, if + + + align:start position:0% +experiences. I mean, historically, if +you were to look at our curriculum + + align:start position:0% +you were to look at our curriculum + + + align:start position:0% +you were to look at our curriculum +across MIT, many more things would be + + align:start position:0% +across MIT, many more things would be + + + align:start position:0% +across MIT, many more things would be +much more like this. I mean, like our + + align:start position:0% +much more like this. I mean, like our + + + align:start position:0% +much more like this. I mean, like our +math curriculum, I think, is very much + + align:start position:0% +math curriculum, I think, is very much + + + align:start position:0% +math curriculum, I think, is very much +this way. Like, you're just going to do + + align:start position:0% +this way. Like, you're just going to do + + + align:start position:0% +this way. Like, you're just going to do +math that other people have figured out + + align:start position:0% +math that other people have figured out + + + align:start position:0% +math that other people have figured out +for years and years, and maybe by the + + align:start position:0% +for years and years, and maybe by the + + + align:start position:0% +for years and years, and maybe by the +time you get to the end of MIT, but you + + align:start position:0% +time you get to the end of MIT, but you + + + align:start position:0% +time you get to the end of MIT, but you +might have to wait till graduate school + + align:start position:0% +might have to wait till graduate school + + + align:start position:0% +might have to wait till graduate school +that you can do some new math that + + align:start position:0% +that you can do some new math that + + + align:start position:0% +that you can do some new math that +someone else has never done before. Um, + + align:start position:0% +someone else has never done before. Um, + + + align:start position:0% +someone else has never done before. Um, +my uh my wife teaches the material + + align:start position:0% +my uh my wife teaches the material + + + align:start position:0% +my uh my wife teaches the material +science department. Um, and uh some of + + align:start position:0% +science department. Um, and uh some of + + + align:start position:0% +science department. Um, and uh some of +the stuff with like the Breaker Lab that + + align:start position:0% +the stuff with like the Breaker Lab that + + + align:start position:0% +the stuff with like the Breaker Lab that +they just developed and things like + + align:start position:0% +they just developed and things like + + + align:start position:0% +they just developed and things like +that. um where like they did an early + + align:start position:0% +that. um where like they did an early + + + align:start position:0% +that. um where like they did an early +exercise in one of our classes which is + + align:start position:0% +exercise in one of our classes which is + + + align:start position:0% +exercise in one of our classes which is +build products from the worst possible + + align:start position:0% +build products from the worst possible + + + align:start position:0% +build products from the worst possible +materials. Um so like phone cases that + + align:start position:0% +materials. Um so like phone cases that + + + align:start position:0% +materials. Um so like phone cases that +were made of sponges and absorbed water + + align:start position:0% +were made of sponges and absorbed water + + + align:start position:0% +were made of sponges and absorbed water +or um locks that were made of clear + + align:start position:0% +or um locks that were made of clear + + + align:start position:0% +or um locks that were made of clear +plastic where you could see all the + + align:start position:0% +plastic where you could see all the + + + align:start position:0% +plastic where you could see all the +tumblers and things like basically like + + align:start position:0% +tumblers and things like basically like + + + align:start position:0% +tumblers and things like basically like +play around with materials, do stuff + + align:start position:0% +play around with materials, do stuff + + + align:start position:0% +play around with materials, do stuff +with materials and then you're going to + + align:start position:0% +with materials and then you're going to + + + align:start position:0% +with materials and then you're going to +take like some super boring really hard + + align:start position:0% +take like some super boring really hard + + + align:start position:0% +take like some super boring really hard +classes but you're motivated to take + + align:start position:0% +classes but you're motivated to take + + + align:start position:0% +classes but you're motivated to take +those things. So I think you can look + + align:start position:0% +those things. So I think you can look + + + align:start position:0% +those things. So I think you can look +across environments um and see how they + + align:start position:0% +across environments um and see how they + + + align:start position:0% +across environments um and see how they +choose different pathways um through + + align:start position:0% +choose different pathways um through + + + align:start position:0% +choose different pathways um through +these uh these different if you look at + + align:start position:0% +these uh these different if you look at + + + align:start position:0% +these uh these different if you look at +reading instruction in the United States + + align:start position:0% +reading instruction in the United States + + + align:start position:0% +reading instruction in the United States +there's a huge debate right now about do + + align:start position:0% +there's a huge debate right now about do + + + align:start position:0% +there's a huge debate right now about do +you start with mastery and facts and + + align:start position:0% +you start with mastery and facts and + + + align:start position:0% +you start with mastery and facts and +pieces and build up to readers um or do + + align:start position:0% +pieces and build up to readers um or do + + + align:start position:0% +pieces and build up to readers um or do +you start by exposing people to books + + align:start position:0% +you start by exposing people to books + + + align:start position:0% +you start by exposing people to books +and letters and words and the things + + align:start position:0% +and letters and words and the things + + + align:start position:0% +and letters and words and the things +they love and and lots of time um you + + align:start position:0% +they love and and lots of time um you + + + align:start position:0% +they love and and lots of time um you +know and almost no course of study is + + align:start position:0% +know and almost no course of study is + + + align:start position:0% +know and almost no course of study is +the answer only one of those things like + + align:start position:0% +the answer only one of those things like + + + align:start position:0% +the answer only one of those things like +nobody believes you should just do + + align:start position:0% +nobody believes you should just do + + + align:start position:0% +nobody believes you should just do +creativity I think almost all of our + + align:start position:0% +creativity I think almost all of our + + + align:start position:0% +creativity I think almost all of our +subjects like have classes which are + + align:start position:0% +subjects like have classes which are + + + align:start position:0% +subjects like have classes which are +like okay time to buckle down and learn + + align:start position:0% +like okay time to buckle down and learn + + + align:start position:0% +like okay time to buckle down and learn +this thing. But we can often think about + + align:start position:0% +this thing. But we can often think about + + + align:start position:0% +this thing. But we can often think about +like how we order these things + + align:start position:0% +like how we order these things + + + align:start position:0% +like how we order these things +differently to produce more motivation + + align:start position:0% +differently to produce more motivation + + + align:start position:0% +differently to produce more motivation +or develop identity or other kinds of + + align:start position:0% +or develop identity or other kinds of + + + align:start position:0% +or develop identity or other kinds of +things like that. Um but again the like + + align:start position:0% +things like that. Um but again the like + + + align:start position:0% +things like that. Um but again the like +across different pedagogical + + align:start position:0% +across different pedagogical + + + align:start position:0% +across different pedagogical +philosophies is almost always the case + + align:start position:0% +philosophies is almost always the case + + + align:start position:0% +philosophies is almost always the case +that people have a very shared idea + + align:start position:0% +that people have a very shared idea + + + align:start position:0% +that people have a very shared idea +about what expertise is. Um so I think + + align:start position:0% +about what expertise is. Um so I think + + + align:start position:0% +about what expertise is. Um so I think +even people who you know um are situated + + align:start position:0% +even people who you know um are situated + + + align:start position:0% +even people who you know um are situated +learning folks um you know they like + + align:start position:0% +learning folks um you know they like + + + align:start position:0% +learning folks um you know they like +they they they don't want you to like + + align:start position:0% +they they they don't want you to like + + + align:start position:0% +they they they don't want you to like +invent midwiffery a new like they want + + align:start position:0% +invent midwiffery a new like they want + + + align:start position:0% +invent midwiffery a new like they want +the babies consistently delivered in + + align:start position:0% +the babies consistently delivered in + + + align:start position:0% +the babies consistently delivered in +safe healthy ways. Um uh so that so it's + + align:start position:0% +safe healthy ways. Um uh so that so it's + + + align:start position:0% +safe healthy ways. Um uh so that so it's +that it's different beliefs about how + + align:start position:0% +that it's different beliefs about how + + + align:start position:0% +that it's different beliefs about how +you get there. Um there are efforts to + + align:start position:0% +you get there. Um there are efforts to + + + align:start position:0% +you get there. Um there are efforts to +reconcile these things which I didn't + + align:start position:0% +reconcile these things which I didn't + + + align:start position:0% +reconcile these things which I didn't +make you read but if you wanted to + + align:start position:0% +make you read but if you wanted to + + + align:start position:0% +make you read but if you wanted to +explore a little bit more I'll give you + + align:start position:0% +explore a little bit more I'll give you + + + align:start position:0% +explore a little bit more I'll give you +an introduction to one of them um in the + + align:start position:0% +an introduction to one of them um in the + + + align:start position:0% +an introduction to one of them um in the +rabbit hole for this week. Ken Kadinger + + align:start position:0% +rabbit hole for this week. Ken Kadinger + + + align:start position:0% +rabbit hole for this week. Ken Kadinger +has a a couple of things you can look + + align:start position:0% +has a a couple of things you can look + + + align:start position:0% +has a a couple of things you can look +at. The the lecture he gives is actually + + align:start position:0% +at. The the lecture he gives is actually + + + align:start position:0% +at. The the lecture he gives is actually +the easiest way of getting it. There's a + + align:start position:0% +the easiest way of getting it. There's a + + + align:start position:0% +the easiest way of getting it. There's a +video in there. It's quite good. Um the + + align:start position:0% +video in there. It's quite good. Um the + + + align:start position:0% +video in there. It's quite good. Um the +knowledge learning instruction framework + + align:start position:0% +knowledge learning instruction framework + + + align:start position:0% +knowledge learning instruction framework +and he says one useful way to think + + align:start position:0% +and he says one useful way to think + + + align:start position:0% +and he says one useful way to think +about this um is that there are um uh + + align:start position:0% +about this um is that there are um uh + + + align:start position:0% +about this um is that there are um uh +more complex and less complex knowledge + + align:start position:0% +more complex and less complex knowledge + + + align:start position:0% +more complex and less complex knowledge +components in the things we learn. So + + align:start position:0% +components in the things we learn. So + + + align:start position:0% +components in the things we learn. So +there are things like um you know + + align:start position:0% +there are things like um you know + + + align:start position:0% +there are things like um you know +Chinese characters and there are things + + align:start position:0% +Chinese characters and there are things + + + align:start position:0% +Chinese characters and there are things +like you know um anthropological + + align:start position:0% +like you know um anthropological + + + align:start position:0% +like you know um anthropological +principles about how society are + + align:start position:0% +principles about how society are + + + align:start position:0% +principles about how society are +organized um and there different levels + + align:start position:0% +organized um and there different levels + + + align:start position:0% +organized um and there different levels +of complexity. There's also um sort of + + align:start position:0% +of complexity. There's also um sort of + + + align:start position:0% +of complexity. There's also um sort of +learning processes and there's things + + align:start position:0% +learning processes and there's things + + + align:start position:0% +learning processes and there's things +like flashc cards um and then you know + + align:start position:0% +like flashc cards um and then you know + + + align:start position:0% +like flashc cards um and then you know +which is just for memorizing stuff um + + align:start position:0% +which is just for memorizing stuff um + + + align:start position:0% +which is just for memorizing stuff um +and then there's things like um talk and + + align:start position:0% +and then there's things like um talk and + + + align:start position:0% +and then there's things like um talk and +explaining and sense making and stuff + + align:start position:0% +explaining and sense making and stuff + + + align:start position:0% +explaining and sense making and stuff +like that um and he has a theory that + + align:start position:0% +like that um and he has a theory that + + + align:start position:0% +like that um and he has a theory that +basically um you know you should be + + align:start position:0% +basically um you know you should be + + + align:start position:0% +basically um you know you should be +matching instructional components to how + + align:start position:0% +matching instructional components to how + + + align:start position:0% +matching instructional components to how +complex um the knowledge component + + align:start position:0% +complex um the knowledge component + + + align:start position:0% +complex um the knowledge component +learning processes to how complex the + + align:start position:0% +learning processes to how complex the + + + align:start position:0% +learning processes to how complex the +knowledge components are. Um he has a + + align:start position:0% +knowledge components are. Um he has a + + + align:start position:0% +knowledge components are. Um he has a +nice uh sort of this is kind of like a + + align:start position:0% +nice uh sort of this is kind of like a + + + align:start position:0% +nice uh sort of this is kind of like a +giant science which is in process where + + align:start position:0% +giant science which is in process where + + + align:start position:0% +giant science which is in process where +here are a bunch of things that people + + align:start position:0% +here are a bunch of things that people + + + align:start position:0% +here are a bunch of things that people +were trying to learn. Chinese vocab, + + align:start position:0% +were trying to learn. Chinese vocab, + + + align:start position:0% +were trying to learn. Chinese vocab, +French articles, chem models, pressure + + align:start position:0% +French articles, chem models, pressure + + + align:start position:0% +French articles, chem models, pressure +concept. Here are a bunch of uh + + align:start position:0% +concept. Here are a bunch of uh + + + align:start position:0% +concept. Here are a bunch of uh +instructional strategies, optimal + + align:start position:0% +instructional strategies, optimal + + + align:start position:0% +instructional strategies, optimal +scheduling, feedback, worked examples, + + align:start position:0% +scheduling, feedback, worked examples, + + + align:start position:0% +scheduling, feedback, worked examples, +accountable talk, collaboration and you + + align:start position:0% +accountable talk, collaboration and you + + + align:start position:0% +accountable talk, collaboration and you +find that like the you know these are + + align:start position:0% +find that like the you know these are + + + align:start position:0% +find that like the you know these are +less complex to more complex teaching. + + align:start position:0% +less complex to more complex teaching. + + + align:start position:0% +less complex to more complex teaching. +this is less complex to more complex um + + align:start position:0% +this is less complex to more complex um + + + align:start position:0% +this is less complex to more complex um +uh uh knowledge components and that like + + align:start position:0% +uh uh knowledge components and that like + + + align:start position:0% +uh uh knowledge components and that like +basically where you get uh studies with + + align:start position:0% +basically where you get uh studies with + + + align:start position:0% +basically where you get uh studies with +statistically significant effects on + + align:start position:0% +statistically significant effects on + + + align:start position:0% +statistically significant effects on +learning is when you kind of move + + align:start position:0% +learning is when you kind of move + + + align:start position:0% +learning is when you kind of move +through the middle of this space when + + align:start position:0% +through the middle of this space when + + + align:start position:0% +through the middle of this space when +you map the right knowledge component to + + align:start position:0% +you map the right knowledge component to + + + align:start position:0% +you map the right knowledge component to +the right learning process. I don't know + + align:start position:0% +the right learning process. I don't know + + + align:start position:0% +the right learning process. I don't know +that Ken Kinger and his colleagues have + + align:start position:0% +that Ken Kinger and his colleagues have + + + align:start position:0% +that Ken Kinger and his colleagues have +totally figured this out either. Um but + + align:start position:0% +totally figured this out either. Um but + + + align:start position:0% +totally figured this out either. Um but +it's one way to start sort of + + align:start position:0% +it's one way to start sort of + + + align:start position:0% +it's one way to start sort of +reconciling some of these ideas. Okay. + + align:start position:0% +reconciling some of these ideas. Okay. + + + align:start position:0% +reconciling some of these ideas. Okay. +Um the the most important thing for + + align:start position:0% +Um the the most important thing for + + + align:start position:0% +Um the the most important thing for +Wednesday is that we're meeting at the + + align:start position:0% +Wednesday is that we're meeting at the + + + align:start position:0% +Wednesday is that we're meeting at the +MIT Museum. Please try to be at the MIT + + align:start position:0% +MIT Museum. Please try to be at the MIT + + + align:start position:0% +MIT Museum. Please try to be at the MIT +Museum. Like if you could if you can get + + align:start position:0% +Museum. Like if you could if you can get + + + align:start position:0% +Museum. Like if you could if you can get +there by 1 and get checked in and put + + align:start position:0% +there by 1 and get checked in and put + + + align:start position:0% +there by 1 and get checked in and put +your bag in the locker, then we can + + align:start position:0% +your bag in the locker, then we can + + + align:start position:0% +your bag in the locker, then we can +start class at 105. So make every effort + + align:start position:0% +start class at 105. So make every effort + + + align:start position:0% +start class at 105. So make every effort +to get there as soon as you can. There's + + align:start position:0% +to get there as soon as you can. There's + + + align:start position:0% +to get there as soon as you can. There's +a few pieces of reading. Um the Steven + + align:start position:0% +a few pieces of reading. Um the Steven + + + align:start position:0% +a few pieces of reading. Um the Steven +Wolf thing is totally worth your time + + align:start position:0% +Wolf thing is totally worth your time + + + align:start position:0% +Wolf thing is totally worth your time +and it will require a little attention. + + align:start position:0% +and it will require a little attention. + + + align:start position:0% +and it will require a little attention. +Like you'll have to sort of move your + + align:start position:0% +Like you'll have to sort of move your + + + align:start position:0% +Like you'll have to sort of move your +way through it, but he does just a + + align:start position:0% +way through it, but he does just a + + + align:start position:0% +way through it, but he does just a +beautiful job explaining the + + align:start position:0% +beautiful job explaining the + + + align:start position:0% +beautiful job explaining the +fundamentals of generative pre-trained + + align:start position:0% +fundamentals of generative pre-trained + + + align:start position:0% +fundamentals of generative pre-trained +models. um a little bit about neural + + align:start position:0% +models. um a little bit about neural + + + align:start position:0% +models. um a little bit about neural +networks and things like that. And then + + align:start position:0% +networks and things like that. And then + + + align:start position:0% +networks and things like that. And then +there's a bunch of other readings that + + align:start position:0% +there's a bunch of other readings that + + + align:start position:0% +there's a bunch of other readings that +are in there. Some of which are about + + align:start position:0% +are in there. Some of which are about + + + align:start position:0% +are in there. Some of which are about +the mu the exhibits you'll see at the + + align:start position:0% +the mu the exhibits you'll see at the + + + align:start position:0% +the mu the exhibits you'll see at the +museum and some are some other + + align:start position:0% +museum and some are some other + + + align:start position:0% +museum and some are some other +educational things that me and some + + align:start position:0% +educational things that me and some + + + align:start position:0% +educational things that me and some +other folks at MIT have written about uh + + align:start position:0% +other folks at MIT have written about uh + + + align:start position:0% +other folks at MIT have written about uh +GPT. Um and then be sure you refresh + + align:start position:0% +GPT. Um and then be sure you refresh + + + align:start position:0% +GPT. Um and then be sure you refresh +yourself and you start thinking about + + align:start position:0% +yourself and you start thinking about + + + align:start position:0% +yourself and you start thinking about +working on the assignment because you + + align:start position:0% +working on the assignment because you + + + align:start position:0% +working on the assignment because you +now have two of the crucial building + + align:start position:0% +now have two of the crucial building + + + align:start position:0% +now have two of the crucial building +blocks that you'll need for the + + align:start position:0% +blocks that you'll need for the + + + align:start position:0% +blocks that you'll need for the +assignment. Um which is some sense of + + align:start position:0% +assignment. Um which is some sense of + + + align:start position:0% +assignment. Um which is some sense of +direct instruction, cognitive load + + align:start position:0% +direct instruction, cognitive load + + + align:start position:0% +direct instruction, cognitive load +theory, and some sense of + + align:start position:0% +theory, and some sense of + + + align:start position:0% +theory, and some sense of +constructionism, situated learning, um + + align:start position:0% +constructionism, situated learning, um + + + align:start position:0% +constructionism, situated learning, um +progressive learning kinds of things. + + align:start position:0% +progressive learning kinds of things. + + + align:start position:0% +progressive learning kinds of things. +And you'll need both of those ideas to + + align:start position:0% +And you'll need both of those ideas to + + + align:start position:0% +And you'll need both of those ideas to +do assignment number one. And we'll talk + + align:start position:0% +do assignment number one. And we'll talk + + + align:start position:0% +do assignment number one. And we'll talk +a little bit about uh how we want to do + + align:start position:0% +a little bit about uh how we want to do + + + align:start position:0% +a little bit about uh how we want to do +assignment number one on Wednesday. Stay + + align:start position:0% +assignment number one on Wednesday. Stay + + + align:start position:0% +assignment number one on Wednesday. Stay +safe in the snow. Have a wonderful uh + + align:start position:0% +safe in the snow. Have a wonderful uh + + + align:start position:0% +safe in the snow. Have a wonderful uh +next couple days. And I'll see you at + + align:start position:0% +next couple days. And I'll see you at + + + align:start position:0% +next couple days. And I'll see you at +the museum on Wednesday. \ No newline at end of file diff --git a/Mge-sj1UVFM.txt b/Mge-sj1UVFM.txt new file mode 100644 index 0000000000000000000000000000000000000000..258c909621b966e7c4c19f6fd36b7a703044a8fa --- /dev/null +++ b/Mge-sj1UVFM.txt @@ -0,0 +1,843 @@ +align:start position:0% + +this is a lecture of how IBM build a + + align:start position:0% +this is a lecture of how IBM build a + + + align:start position:0% +this is a lecture of how IBM build a +computer that plays a very popular game + + align:start position:0% +computer that plays a very popular game + + + align:start position:0% +computer that plays a very popular game +of Jeopardy in 2004 IBM vice president + + align:start position:0% +of Jeopardy in 2004 IBM vice president + + + align:start position:0% +of Jeopardy in 2004 IBM vice president +Charlie CO and co-workers were having + + align:start position:0% +Charlie CO and co-workers were having + + + align:start position:0% +Charlie CO and co-workers were having +dinner at the restaurant all of a sudden + + align:start position:0% +dinner at the restaurant all of a sudden + + + align:start position:0% +dinner at the restaurant all of a sudden +the restaurant fell silent everyone was + + align:start position:0% +the restaurant fell silent everyone was + + + align:start position:0% +the restaurant fell silent everyone was +watching the game jeopardy on the + + align:start position:0% +watching the game jeopardy on the + + + align:start position:0% +watching the game jeopardy on the +television a contention Ken Jennings was + + align:start position:0% +television a contention Ken Jennings was + + + align:start position:0% +television a contention Ken Jennings was +setting the record for the longest + + align:start position:0% +setting the record for the longest + + + align:start position:0% +setting the record for the longest +winning streak of all times 75 days why + + align:start position:0% +winning streak of all times 75 days why + + + align:start position:0% +winning streak of all times 75 days why +was everyone so interested Joe Pardy is + + align:start position:0% +was everyone so interested Joe Pardy is + + + align:start position:0% +was everyone so interested Joe Pardy is +a quiz show that asks complex and clever + + align:start position:0% +a quiz show that asks complex and clever + + + align:start position:0% +a quiz show that asks complex and clever +questions like pans of score facts and + + align:start position:0% +questions like pans of score facts and + + + align:start position:0% +questions like pans of score facts and +uncommon words it originally aired in + + align:start position:0% +uncommon words it originally aired in + + + align:start position:0% +uncommon words it originally aired in +1964 it covers a huge variety of topics + + align:start position:0% +1964 it covers a huge variety of topics + + + align:start position:0% +1964 it covers a huge variety of topics +and is generally viewed as an impressive + + align:start position:0% +and is generally viewed as an impressive + + + align:start position:0% +and is generally viewed as an impressive +feat to do well in this game no computer + + align:start position:0% +feat to do well in this game no computer + + + align:start position:0% +feat to do well in this game no computer +system has ever been developed that + + align:start position:0% +system has ever been developed that + + + align:start position:0% +system has ever been developed that +could even come close to competing with + + align:start position:0% +could even come close to competing with + + + align:start position:0% +could even come close to competing with +humans on Jeopardy IBM Research strives + + align:start position:0% +humans on Jeopardy IBM Research strives + + + align:start position:0% +humans on Jeopardy IBM Research strives +to push the limits of science it has a + + align:start position:0% +to push the limits of science it has a + + + align:start position:0% +to push the limits of science it has a +tradition of addressing inspiring and + + align:start position:0% +tradition of addressing inspiring and + + + align:start position:0% +tradition of addressing inspiring and +difficult challenges over the years in + + align:start position:0% +difficult challenges over the years in + + + align:start position:0% +difficult challenges over the years in +the mid-90s it built deep-blue a + + align:start position:0% +the mid-90s it built deep-blue a + + + align:start position:0% +the mid-90s it built deep-blue a +computer to compete against the best + + align:start position:0% +computer to compete against the best + + + align:start position:0% +computer to compete against the best +human chess players and then the mid-90s + + align:start position:0% +human chess players and then the mid-90s + + + align:start position:0% +human chess players and then the mid-90s +the blue bit Garry Kasparov who was at + + align:start position:0% +the blue bit Garry Kasparov who was at + + + align:start position:0% +the blue bit Garry Kasparov who was at +that time world champion in chess later + + align:start position:0% +that time world champion in chess later + + + align:start position:0% +that time world champion in chess later +it built Blue Gene a computer to map the + + align:start position:0% +it built Blue Gene a computer to map the + + + align:start position:0% +it built Blue Gene a computer to map the +human human genome in 2005 a team at IBM + + align:start position:0% +human human genome in 2005 a team at IBM + + + align:start position:0% +human human genome in 2005 a team at IBM +research started creating a computer + + align:start position:0% +research started creating a computer + + + align:start position:0% +research started creating a computer +that would compete at jeopardy of course + + align:start position:0% +that would compete at jeopardy of course + + + align:start position:0% +that would compete at jeopardy of course +no one knew at the time how to beat + + align:start position:0% +no one knew at the time how to beat + + + align:start position:0% +no one knew at the time how to beat +humans or even if it was even possible + + align:start position:0% +humans or even if it was even possible + + + align:start position:0% +humans or even if it was even possible +six years later a two-game exhibition + + align:start position:0% +six years later a two-game exhibition + + + align:start position:0% +six years later a two-game exhibition +match aired on television the winner + + align:start position:0% +match aired on television the winner + + + align:start position:0% +match aired on television the winner +would receive a million dollars the + + align:start position:0% +would receive a million dollars the + + + align:start position:0% +would receive a million dollars the +contentions were Ken Jennings the + + align:start position:0% +contentions were Ken Jennings the + + + align:start position:0% +contentions were Ken Jennings the +longest winning champion whose longest + + align:start position:0% +longest winning champion whose longest + + + align:start position:0% +longest winning champion whose longest +winning streak was 75 days Brad Rutter + + align:start position:0% +winning streak was 75 days Brad Rutter + + + align:start position:0% +winning streak was 75 days Brad Rutter +who was the biggest money winner of over + + align:start position:0% +who was the biggest money winner of over + + + align:start position:0% +who was the biggest money winner of over +3.5 million and watch on a supercomputer + + align:start position:0% +3.5 million and watch on a supercomputer + + + align:start position:0% +3.5 million and watch on a supercomputer +with 3000 + + align:start position:0% +with 3000 + + + align:start position:0% +with 3000 +and processors in a database of 200 + + align:start position:0% +and processors in a database of 200 + + + align:start position:0% +and processors in a database of 200 +million pages of information + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +and welcome everyone to a very special + + align:start position:0% +and welcome everyone to a very special + + + align:start position:0% +and welcome everyone to a very special +jeopardy event for the next three days + + align:start position:0% +jeopardy event for the next three days + + + align:start position:0% +jeopardy event for the next three days +we're gonna be coming to you from this + + align:start position:0% +we're gonna be coming to you from this + + + align:start position:0% +we're gonna be coming to you from this +IBM research facility just outside of + + align:start position:0% +IBM research facility just outside of + + + align:start position:0% +IBM research facility just outside of +New York City + + align:start position:0% +New York City + + + align:start position:0% +New York City +let me tell you why a little over three + + align:start position:0% +let me tell you why a little over three + + + align:start position:0% +let me tell you why a little over three +years ago the folks at IBM came to us + + align:start position:0% +years ago the folks at IBM came to us + + + align:start position:0% +years ago the folks at IBM came to us +with a proposal that they considered to + + align:start position:0% +with a proposal that they considered to + + + align:start position:0% +with a proposal that they considered to +be the next grand challenge in computing + + align:start position:0% +be the next grand challenge in computing + + + align:start position:0% +be the next grand challenge in computing +and that was designing a computer system + + align:start position:0% +and that was designing a computer system + + + align:start position:0% +and that was designing a computer system +that could understand the complexities + + align:start position:0% +that could understand the complexities + + + align:start position:0% +that could understand the complexities +of natural language well enough to + + align:start position:0% +of natural language well enough to + + + align:start position:0% +of natural language well enough to +compete against Jeopardy's best players + + align:start position:0% +compete against Jeopardy's best players + + + align:start position:0% +compete against Jeopardy's best players +well they think they've succeeded and + + align:start position:0% +well they think they've succeeded and + + + align:start position:0% +well they think they've succeeded and +that's why we're here today so you are + + align:start position:0% +that's why we're here today so you are + + + align:start position:0% +that's why we're here today so you are +about to witness what may prove to be an + + align:start position:0% +about to witness what may prove to be an + + + align:start position:0% +about to witness what may prove to be an +historic competition an exhibition match + + align:start position:0% +historic competition an exhibition match + + + align:start position:0% +historic competition an exhibition match +pitting an IBM computer system against + + align:start position:0% +pitting an IBM computer system against + + + align:start position:0% +pitting an IBM computer system against +the two most celebrated and successful + + align:start position:0% +the two most celebrated and successful + + + align:start position:0% +the two most celebrated and successful +players in jeopardy history sounds like + + align:start position:0% +players in jeopardy history sounds like + + + align:start position:0% +players in jeopardy history sounds like +a lot of fun doesn't it developed and + + align:start position:0% +a lot of fun doesn't it developed and + + + align:start position:0% +a lot of fun doesn't it developed and +programmed especially for this moment + + align:start position:0% +programmed especially for this moment + + + align:start position:0% +programmed especially for this moment +making its first appearance on our + + align:start position:0% +making its first appearance on our + + + align:start position:0% +making its first appearance on our +national television program ladies and + + align:start position:0% +national television program ladies and + + + align:start position:0% +national television program ladies and +gentlemen this is Watson + + align:start position:0% + + + + align:start position:0% + +just as I expected that was a very warm + + align:start position:0% +just as I expected that was a very warm + + + align:start position:0% +just as I expected that was a very warm +reception and I'm sure Watson would have + + align:start position:0% +reception and I'm sure Watson would have + + + align:start position:0% +reception and I'm sure Watson would have +appreciated the applause except for one + + align:start position:0% +appreciated the applause except for one + + + align:start position:0% +appreciated the applause except for one +thing + + align:start position:0% +thing + + + align:start position:0% +thing +Watson can neither hear nor see it will + + align:start position:0% +Watson can neither hear nor see it will + + + align:start position:0% +Watson can neither hear nor see it will +be receiving all of its information late + + align:start position:0% +be receiving all of its information late + + + align:start position:0% +be receiving all of its information late +and as a matter of fact what you're + + align:start position:0% +and as a matter of fact what you're + + + align:start position:0% +and as a matter of fact what you're +looking at right now is not the real + + align:start position:0% +looking at right now is not the real + + + align:start position:0% +looking at right now is not the real +Watson this is an avatar this is a + + align:start position:0% +Watson this is an avatar this is a + + + align:start position:0% +Watson this is an avatar this is a +representation of Watson Watson of + + align:start position:0% +representation of Watson Watson of + + + align:start position:0% +representation of Watson Watson of +course is a sophisticated computer + + align:start position:0% +course is a sophisticated computer + + + align:start position:0% +course is a sophisticated computer +system too big and too heavy to fit + + align:start position:0% +system too big and too heavy to fit + + + align:start position:0% +system too big and too heavy to fit +behind that lecture on our stage but it + + align:start position:0% +behind that lecture on our stage but it + + + align:start position:0% +behind that lecture on our stage but it +is close by it's right next door and a + + align:start position:0% +is close by it's right next door and a + + + align:start position:0% +is close by it's right next door and a +little while ago I paid it a visit the + + align:start position:0% +little while ago I paid it a visit the + + + align:start position:0% +little while ago I paid it a visit the +very first thing you will notice as I + + align:start position:0% +very first thing you will notice as I + + + align:start position:0% +very first thing you will notice as I +come in to Watson's space is noise there + + align:start position:0% +come in to Watson's space is noise there + + + align:start position:0% +come in to Watson's space is noise there +is a lot of noise a little bit comes + + align:start position:0% +is a lot of noise a little bit comes + + + align:start position:0% +is a lot of noise a little bit comes +from Watson himself but most of the + + align:start position:0% +from Watson himself but most of the + + + align:start position:0% +from Watson himself but most of the +noise comes from two very large + + align:start position:0% +noise comes from two very large + + + align:start position:0% +noise comes from two very large +refrigerator units that help to keep + + align:start position:0% +refrigerator units that help to keep + + + align:start position:0% +refrigerator units that help to keep +Watson cool now as you can see Watson + + align:start position:0% +Watson cool now as you can see Watson + + + align:start position:0% +Watson cool now as you can see Watson +has been set up in two units each half + + align:start position:0% +has been set up in two units each half + + + align:start position:0% +has been set up in two units each half +contains five separate Rex each of these + + align:start position:0% +contains five separate Rex each of these + + + align:start position:0% +contains five separate Rex each of these +racks contains ten IBM power 750 servers + + align:start position:0% +racks contains ten IBM power 750 servers + + + align:start position:0% +racks contains ten IBM power 750 servers +now when you link all of these servers + + align:start position:0% +now when you link all of these servers + + + align:start position:0% +now when you link all of these servers +together as they have done for Watson + + align:start position:0% +together as they have done for Watson + + + align:start position:0% +together as they have done for Watson +you create a deep analytic system that + + align:start position:0% +you create a deep analytic system that + + + align:start position:0% +you create a deep analytic system that +is the equivalent of two thousand eight + + align:start position:0% +is the equivalent of two thousand eight + + + align:start position:0% +is the equivalent of two thousand eight +hundred powerful computers tied together + + align:start position:0% +hundred powerful computers tied together + + + align:start position:0% +hundred powerful computers tied together +in a super high-speed network + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/MjRb8R33Ucc.txt b/MjRb8R33Ucc.txt new file mode 100644 index 0000000000000000000000000000000000000000..a299b427bba21e6e6a562641eb741d6ecbad0877 --- /dev/null +++ b/MjRb8R33Ucc.txt @@ -0,0 +1,11363 @@ +align:start position:0% + +Okay. So let's so assume that again that + + align:start position:0% +Okay. So let's so assume that again that + + + align:start position:0% +Okay. So let's so assume that again that +we have a so this here is a sequence + + align:start position:0% + + + + align:start position:0% + +then we can form from a sequence we can + + align:start position:0% +then we can form from a sequence we can + + + align:start position:0% +then we can form from a sequence we can +find we can form another sequence. So + + align:start position:0% +find we can form another sequence. So + + + align:start position:0% +find we can form another sequence. So +from + + align:start position:0% +from + + + align:start position:0% +from +from a end we can form + + align:start position:0% + + + + align:start position:0% + +another sequence. + + align:start position:0% + + + + align:start position:0% + +uh at least if um at least + + align:start position:0% +uh at least if um at least + + + align:start position:0% +uh at least if um at least +if a end is bounded from above. + + align:start position:0% + + + + align:start position:0% + +So we can form another sequence and + + align:start position:0% +So we can form another sequence and + + + align:start position:0% +So we can form another sequence and +that's what we we take + + align:start position:0% +that's what we we take + + + align:start position:0% +that's what we we take +uh bn + + align:start position:0% +uh bn + + + align:start position:0% +uh bn +is going to be the soup of the set + + align:start position:0% +is going to be the soup of the set + + + align:start position:0% +is going to be the soup of the set +of a starting at n. So this here is is + + align:start position:0% +of a starting at n. So this here is is + + + align:start position:0% +of a starting at n. So this here is is +oops this here is the the sequence bn. + + align:start position:0% +oops this here is the the sequence bn. + + + align:start position:0% +oops this here is the the sequence bn. +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +And so right again implicitly here we + + align:start position:0% +And so right again implicitly here we + + + align:start position:0% +And so right again implicitly here we +are assuming so assume + + align:start position:0% + + + + align:start position:0% + +that uh that there exist + + align:start position:0% + + + + align:start position:0% + +some c so that for all n + + align:start position:0% + + + + align:start position:0% + +uh a n is less than c in other words c + + align:start position:0% +uh a n is less than c in other words c + + + align:start position:0% +uh a n is less than c in other words c +are bounded from above right so if we If + + align:start position:0% +are bounded from above right so if we If + + + align:start position:0% +are bounded from above right so if we If +we if the sequence a n is bounded from + + align:start position:0% +we if the sequence a n is bounded from + + + align:start position:0% +we if the sequence a n is bounded from +above then this here gives us a real + + align:start position:0% +above then this here gives us a real + + + align:start position:0% +above then this here gives us a real +number + + align:start position:0% +number + + + align:start position:0% +number +uh and we see + + align:start position:0% +uh and we see + + + align:start position:0% +uh and we see +and we see that since if you're looking + + align:start position:0% +and we see that since if you're looking + + + align:start position:0% +and we see that since if you're looking +at uh bn + one this is now soup of a n + + + align:start position:0% +at uh bn + one this is now soup of a n + + + + align:start position:0% +at uh bn + one this is now soup of a n + +one a n + 2 + + align:start position:0% +one a n + 2 + + + align:start position:0% +one a n + 2 +and this here is soup over a smaller + + align:start position:0% +and this here is soup over a smaller + + + align:start position:0% +and this here is soup over a smaller +set. So this here is less than the soup + + align:start position:0% +set. So this here is less than the soup + + + align:start position:0% +set. So this here is less than the soup +where we do it over where we take soup + + align:start position:0% +where we do it over where we take soup + + + align:start position:0% +where we do it over where we take soup +over a larger set. + + align:start position:0% +over a larger set. + + + align:start position:0% +over a larger set. +Right? + + align:start position:0% +Right? + + + align:start position:0% +Right? +And that here is BN. + + align:start position:0% + + + + align:start position:0% + +So we have that if you take any sequence + + align:start position:0% +So we have that if you take any sequence + + + align:start position:0% +So we have that if you take any sequence +then you can and let's say that that + + align:start position:0% +then you can and let's say that that + + + align:start position:0% +then you can and let's say that that +sequence is bounded from above then you + + align:start position:0% +sequence is bounded from above then you + + + align:start position:0% +sequence is bounded from above then you +can find another you can form another + + align:start position:0% +can find another you can form another + + + align:start position:0% +can find another you can form another +sequence BN and BN here is mono + + align:start position:0% +sequence BN and BN here is mono + + + align:start position:0% +sequence BN and BN here is mono +decreasing right + + align:start position:0% + + + + align:start position:0% + +if + + align:start position:0% +if + + + align:start position:0% +if +if also if the sequence + + align:start position:0% + + + + align:start position:0% + +BN is bound from below + + align:start position:0% + + + + align:start position:0% + +then uh then the BN here in the sequence + + align:start position:0% +then uh then the BN here in the sequence + + + align:start position:0% +then uh then the BN here in the sequence +here converge and it converts to the + + align:start position:0% +here converge and it converts to the + + + align:start position:0% +here converge and it converts to the +infam right this is this uh with mono + + align:start position:0% +infam right this is this uh with mono + + + align:start position:0% +infam right this is this uh with mono +convergent sequences it's converging to + + align:start position:0% +convergent sequences it's converging to + + + align:start position:0% +convergent sequences it's converging to +the infimum of the BI + + align:start position:0% + + + + align:start position:0% + +like that. + + align:start position:0% +like that. + + + align:start position:0% +like that. +Okay. + + align:start position:0% + + + + align:start position:0% + +Now, um + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +and and likewise, so likewise, although + + align:start position:0% +and and likewise, so likewise, although + + + align:start position:0% +and and likewise, so likewise, although +we won't really use this here. So, + + align:start position:0% +we won't really use this here. So, + + + align:start position:0% +we won't really use this here. So, +likewise, but likewise, + + align:start position:0% + + + + align:start position:0% + +Um again if you take if a n is any + + align:start position:0% +Um again if you take if a n is any + + + align:start position:0% +Um again if you take if a n is any +sequence any sequence + + align:start position:0% +sequence any sequence + + + align:start position:0% +sequence any sequence +this time I want it to be bounded from + + align:start position:0% +this time I want it to be bounded from + + + align:start position:0% +this time I want it to be bounded from +below + + align:start position:0% + + + + align:start position:0% + +then you can find a sequence then you + + align:start position:0% +then you can find a sequence then you + + + align:start position:0% +then you can find a sequence then you +can form from a n you can form a + + align:start position:0% +can form from a n you can form a + + + align:start position:0% +can form from a n you can form a +sequence uh cn and cn is just where + + align:start position:0% +sequence uh cn and cn is just where + + + align:start position:0% +sequence uh cn and cn is just where +you're taking the infam one starting at + + align:start position:0% +you're taking the infam one starting at + + + align:start position:0% +you're taking the infam one starting at +a end, + + align:start position:0% + + + + align:start position:0% + +right? And you see that if you're + + align:start position:0% +right? And you see that if you're + + + align:start position:0% +right? And you see that if you're +looking at CN + one, then you take the + + align:start position:0% +looking at CN + one, then you take the + + + align:start position:0% +looking at CN + one, then you take the +infom over a smaller set. + + align:start position:0% + + + + align:start position:0% + +So this is a smaller set and so this + + align:start position:0% +So this is a smaller set and so this + + + align:start position:0% +So this is a smaller set and so this +here is bigger than where you're taking + + align:start position:0% +here is bigger than where you're taking + + + align:start position:0% +here is bigger than where you're taking +the info from a end + + align:start position:0% + + + + align:start position:0% + +and that's CN. So the sequence CN is + + align:start position:0% +and that's CN. So the sequence CN is + + + align:start position:0% +and that's CN. So the sequence CN is +therefore monotone increasing and if it + + align:start position:0% +therefore monotone increasing and if it + + + align:start position:0% +therefore monotone increasing and if it +is bounded. So if CN is bounded from + + align:start position:0% +is bounded. So if CN is bounded from + + + align:start position:0% +is bounded. So if CN is bounded from +above + + align:start position:0% + + + + align:start position:0% + +is bounded from above. + + align:start position:0% + + + + align:start position:0% + +Then the sequence CN converge to some C. + + align:start position:0% +Then the sequence CN converge to some C. + + + align:start position:0% +Then the sequence CN converge to some C. +And that sea is just a soup of the of + + align:start position:0% +And that sea is just a soup of the of + + + align:start position:0% +And that sea is just a soup of the of +the seas, + + align:start position:0% +the seas, + + + align:start position:0% +the seas, +right? + + align:start position:0% +right? + + + align:start position:0% +right? +And so and we talked a little bit about + + align:start position:0% +And so and we talked a little bit about + + + align:start position:0% +And so and we talked a little bit about +this earlier, right? And the thing is + + align:start position:0% +this earlier, right? And the thing is + + + align:start position:0% +this earlier, right? And the thing is +that but now we will use it in just a + + align:start position:0% +that but now we will use it in just a + + + align:start position:0% +that but now we will use it in just a +second. + + align:start position:0% +second. + + + align:start position:0% +second. +The thing is so that in the first case + + align:start position:0% +The thing is so that in the first case + + + align:start position:0% +The thing is so that in the first case +here we call B here B is written as a + + align:start position:0% +here we call B here B is written as a + + + align:start position:0% +here we call B here B is written as a +lem + + align:start position:0% +lem + + + align:start position:0% +lem +soup of of the of the an + + align:start position:0% +soup of of the of the an + + + align:start position:0% +soup of of the of the an +and in the second case it's called the + + align:start position:0% +and in the second case it's called the + + + align:start position:0% +and in the second case it's called the +lem in + + align:start position:0% +lem in + + + align:start position:0% +lem in +uh of of the a + + align:start position:0% +uh of of the a + + + align:start position:0% +uh of of the a +okay + + align:start position:0% + + + + align:start position:0% + +now + + align:start position:0% + + + + align:start position:0% + +so why is this relevant here for us so + + align:start position:0% +so why is this relevant here for us so + + + align:start position:0% +so why is this relevant here for us so +what we were looking at last time So + + align:start position:0% +what we were looking at last time So + + + align:start position:0% +what we were looking at last time So +last time and I'm only going to use the + + align:start position:0% +last time and I'm only going to use the + + + align:start position:0% +last time and I'm only going to use the +lem soup. So last time + + align:start position:0% +lem soup. So last time + + + align:start position:0% +lem soup. So last time +we had a sequence. So a n is a sequence + + align:start position:0% +we had a sequence. So a n is a sequence + + + align:start position:0% +we had a sequence. So a n is a sequence +or was a sequence + + align:start position:0% + + + + align:start position:0% + +and we looked we defined what we call a + + align:start position:0% +and we looked we defined what we call a + + + align:start position:0% +and we looked we defined what we call a +power series. And again power series + + align:start position:0% +power series. And again power series + + + align:start position:0% +power series. And again power series +think about that x as being just some + + align:start position:0% +think about that x as being just some + + + align:start position:0% +think about that x as being just some +fixed number + + align:start position:0% +fixed number + + + align:start position:0% +fixed number +and you have the sequence a n x is some + + align:start position:0% +and you have the sequence a n x is some + + + align:start position:0% +and you have the sequence a n x is some +fixed number and then you form the + + align:start position:0% +fixed number and then you form the + + + align:start position:0% +fixed number and then you form the +sequence a n xn right + + align:start position:0% +sequence a n xn right + + + align:start position:0% +sequence a n xn right +and so for each x fixed this gives you + + align:start position:0% +and so for each x fixed this gives you + + + align:start position:0% +and so for each x fixed this gives you +some number maybe if it converge I mean + + align:start position:0% +some number maybe if it converge I mean + + + align:start position:0% +some number maybe if it converge I mean +you can ask for each x you can ask does + + align:start position:0% +you can ask for each x you can ask does + + + align:start position:0% +you can ask for each x you can ask does +this sequence converge or + + align:start position:0% +this sequence converge or + + + align:start position:0% +this sequence converge or +And this here is called a power series. + + align:start position:0% +And this here is called a power series. + + + align:start position:0% +And this here is called a power series. +So you're suming from zero to whatever + + align:start position:0% +So you're suming from zero to whatever + + + align:start position:0% +So you're suming from zero to whatever +or you're signing from one or whatever + + align:start position:0% +or you're signing from one or whatever + + + align:start position:0% +or you're signing from one or whatever +you're starting with up to infinity. So + + align:start position:0% +you're starting with up to infinity. So + + + align:start position:0% +you're starting with up to infinity. So +this here is a power series. + + align:start position:0% +this here is a power series. + + + align:start position:0% +this here is a power series. +And so now it for power says the the the + + align:start position:0% +And so now it for power says the the the + + + align:start position:0% +And so now it for power says the the the +question is + + align:start position:0% +question is + + + align:start position:0% +question is +how serious is the question is what + + align:start position:0% +how serious is the question is what + + + align:start position:0% +how serious is the question is what +about for which + + align:start position:0% +about for which + + + align:start position:0% +about for which +for which + + align:start position:0% +for which + + + align:start position:0% +for which +X does it converge. + + align:start position:0% + + + + align:start position:0% + +Okay, so that's what we're interested in + + align:start position:0% +Okay, so that's what we're interested in + + + align:start position:0% +Okay, so that's what we're interested in +and what we looked at last time. + + align:start position:0% +and what we looked at last time. + + + align:start position:0% +and what we looked at last time. +So just let me remind you because we're + + align:start position:0% +So just let me remind you because we're + + + align:start position:0% +So just let me remind you because we're +going to use that anyway in a minute + + align:start position:0% +going to use that anyway in a minute + + + align:start position:0% +going to use that anyway in a minute +last time. So example + + align:start position:0% + + + + align:start position:0% + +from last time + + align:start position:0% + + + + align:start position:0% + +Well, the example we looked at last time + + align:start position:0% +Well, the example we looked at last time + + + align:start position:0% +Well, the example we looked at last time +was we're looking at xn. I mean, we + + align:start position:0% +was we're looking at xn. I mean, we + + + align:start position:0% +was we're looking at xn. I mean, we +looked at some other examples too, but + + align:start position:0% +looked at some other examples too, but + + + align:start position:0% +looked at some other examples too, but +this was the one we focused on. + + align:start position:0% +this was the one we focused on. + + + align:start position:0% +this was the one we focused on. +So, this here is a power series. The a n + + align:start position:0% +So, this here is a power series. The a n + + + align:start position:0% +So, this here is a power series. The a n +in this case here + + align:start position:0% +in this case here + + + align:start position:0% +in this case here +are one over n factorial, right? + + align:start position:0% +are one over n factorial, right? + + + align:start position:0% +are one over n factorial, right? +So now uh and we and for each fixed x so + + align:start position:0% +So now uh and we and for each fixed x so + + + align:start position:0% +So now uh and we and for each fixed x so +for for x fixed + + align:start position:0% +for for x fixed + + + align:start position:0% +for for x fixed +we looked at whether or not this + + align:start position:0% +we looked at whether or not this + + + align:start position:0% +we looked at whether or not this +sequence converge and so we defined we + + align:start position:0% +sequence converge and so we defined we + + + align:start position:0% +sequence converge and so we defined we +think about this thing here we thought + + align:start position:0% +think about this thing here we thought + + + align:start position:0% +think about this thing here we thought +this here we thought about it as just a + + align:start position:0% +this here we thought about it as just a + + + align:start position:0% +this here we thought about it as just a +sequence like this + + align:start position:0% +sequence like this + + + align:start position:0% +sequence like this +sum of of a sequence so this is as a + + align:start position:0% +sum of of a sequence so this is as a + + + align:start position:0% +sum of of a sequence so this is as a +series like is where the dn here is now + + align:start position:0% +series like is where the dn here is now + + + align:start position:0% +series like is where the dn here is now +x to the n / n factorial right + + align:start position:0% +x to the n / n factorial right + + + align:start position:0% +x to the n / n factorial right +and so in order to determine for which x + + align:start position:0% +and so in order to determine for which x + + + align:start position:0% +and so in order to determine for which x +it converge so just think about x as + + align:start position:0% +it converge so just think about x as + + + align:start position:0% +it converge so just think about x as +being fixed we use the ratio test + + align:start position:0% + + + + align:start position:0% + +so we use the ratio test + + align:start position:0% +so we use the ratio test + + + align:start position:0% +so we use the ratio test +and the ratio test um said that If + + align:start position:0% +and the ratio test um said that If + + + align:start position:0% +and the ratio test um said that If +you're looking at dn + 1 / dn, + + align:start position:0% +you're looking at dn + 1 / dn, + + + align:start position:0% +you're looking at dn + 1 / dn, +this here is well dn is just x to the n + + align:start position:0% +this here is well dn is just x to the n + + + align:start position:0% +this here is well dn is just x to the n ++ 1 / n + 1 factorial divided by x to + + align:start position:0% ++ 1 / n + 1 factorial divided by x to + + + align:start position:0% ++ 1 / n + 1 factorial divided by x to +the n / n factorial. + + align:start position:0% +the n / n factorial. + + + align:start position:0% +the n / n factorial. +And that's the same, right? So when you + + align:start position:0% +And that's the same, right? So when you + + + align:start position:0% +And that's the same, right? So when you +divide by a fraction, you just switch, + + align:start position:0% +divide by a fraction, you just switch, + + + align:start position:0% +divide by a fraction, you just switch, +right? So this is the same as x to the n + + align:start position:0% +right? So this is the same as x to the n + + + align:start position:0% +right? So this is the same as x to the n ++ 1 / n + 1 factorial * n factorial * x + + align:start position:0% ++ 1 / n + 1 factorial * n factorial * x + + + align:start position:0% ++ 1 / n + 1 factorial * n factorial * x +to the n. And you just think about this + + align:start position:0% +to the n. And you just think about this + + + align:start position:0% +to the n. And you just think about this +the top here as x n * x * n factorial. + + align:start position:0% +the top here as x n * x * n factorial. + + + align:start position:0% +the top here as x n * x * n factorial. +And the denominator you think about as n + + align:start position:0% +And the denominator you think about as n + + + align:start position:0% +And the denominator you think about as n ++1 * n factorial * x. You see that this + + align:start position:0% ++1 * n factorial * x. You see that this + + + align:start position:0% ++1 * n factorial * x. You see that this +here and this here cancel with those two + + align:start position:0% +here and this here cancel with those two + + + align:start position:0% +here and this here cancel with those two +and so you get x / n +1 + + align:start position:0% +and so you get x / n +1 + + + align:start position:0% +and so you get x / n +1 +and this here converts to zero right so + + align:start position:0% +and this here converts to zero right so + + + align:start position:0% +and this here converts to zero right so +therefore the power series is convergent + + align:start position:0% +therefore the power series is convergent + + + align:start position:0% +therefore the power series is convergent +for all x + + align:start position:0% +for all x + + + align:start position:0% +for all x +now so that was a particular example of + + align:start position:0% +now so that was a particular example of + + + align:start position:0% +now so that was a particular example of +a power series right but so uh and and + + align:start position:0% +a power series right but so uh and and + + + align:start position:0% +a power series right but so uh and and +and it worked uh well with ratio test, + + align:start position:0% +and it worked uh well with ratio test, + + + align:start position:0% +and it worked uh well with ratio test, +but but the root test actually is + + align:start position:0% +but but the root test actually is + + + align:start position:0% +but but the root test actually is +better. And this was related to a point + + align:start position:0% +better. And this was related to a point + + + align:start position:0% +better. And this was related to a point +somebody raised uh last time. And the + + align:start position:0% +somebody raised uh last time. And the + + + align:start position:0% +somebody raised uh last time. And the +point was like you know like for the + + align:start position:0% +point was like you know like for the + + + align:start position:0% +point was like you know like for the +ratio test it was you know implicitly + + align:start position:0% +ratio test it was you know implicitly + + + align:start position:0% +ratio test it was you know implicitly +somehow in the ratio test was something + + align:start position:0% +somehow in the ratio test was something + + + align:start position:0% +somehow in the ratio test was something +about that from a some stage on the next + + align:start position:0% +about that from a some stage on the next + + + align:start position:0% +about that from a some stage on the next +element is smaller than the previous one + + align:start position:0% +element is smaller than the previous one + + + align:start position:0% +element is smaller than the previous one +and you don't really need to have that + + align:start position:0% +and you don't really need to have that + + + align:start position:0% +and you don't really need to have that +uh uh you know I mean you certainly + + align:start position:0% +uh uh you know I mean you certainly + + + align:start position:0% +uh uh you know I mean you certainly +don't need it for a series to converge + + align:start position:0% +don't need it for a series to converge + + + align:start position:0% +don't need it for a series to converge +but but it's not even necessary if you + + align:start position:0% +but but it's not even necessary if you + + + align:start position:0% +but but it's not even necessary if you +apply the right test right + + align:start position:0% +apply the right test right + + + align:start position:0% +apply the right test right +and so + + align:start position:0% +and so + + + align:start position:0% +and so +so this come this this this bring us to + + align:start position:0% +so this come this this this bring us to + + + align:start position:0% +so this come this this this bring us to +what's called the radius of convergence + + align:start position:0% +what's called the radius of convergence + + + align:start position:0% +what's called the radius of convergence +so so this is a a crucial concept + + align:start position:0% +so so this is a a crucial concept + + + align:start position:0% +so so this is a a crucial concept +and why it is crucial concept because + + align:start position:0% +and why it is crucial concept because + + + align:start position:0% +and why it is crucial concept because +you see appro what you could imagine so + + align:start position:0% +you see appro what you could imagine so + + + align:start position:0% +you see appro what you could imagine so +suppose you just take + + align:start position:0% +suppose you just take + + + align:start position:0% +suppose you just take +suppose you just write down a power + + align:start position:0% +suppose you just write down a power + + + align:start position:0% +suppose you just write down a power +shares like this + + align:start position:0% +shares like this + + + align:start position:0% +shares like this +appro + + align:start position:0% +appro + + + align:start position:0% +appro +maybe like that it's convergent for at + + align:start position:0% +maybe like that it's convergent for at + + + align:start position:0% +maybe like that it's convergent for at +when x is equal to 5 it's divergent when + + align:start position:0% +when x is equal to 5 it's divergent when + + + align:start position:0% +when x is equal to 5 it's divergent when +x is equal to 10 and maybe it's + + align:start position:0% +x is equal to 10 and maybe it's + + + align:start position:0% +x is equal to 10 and maybe it's +convergent again if x is equal to 20 + + align:start position:0% +convergent again if x is equal to 20 + + + align:start position:0% +convergent again if x is equal to 20 +right that's not actually going to be + + align:start position:0% +right that's not actually going to be + + + align:start position:0% +right that's not actually going to be +the case so there's something called + + align:start position:0% +the case so there's something called + + + align:start position:0% +the case so there's something called +radius of convergence + + align:start position:0% + + + + align:start position:0% + +and the radius of convergence + + align:start position:0% + + + + align:start position:0% + +And the thing is that what you get out + + align:start position:0% +And the thing is that what you get out + + + align:start position:0% +And the thing is that what you get out +of this radius of convergence is that a + + align:start position:0% +of this radius of convergence is that a + + + align:start position:0% +of this radius of convergence is that a +power series like this is convergent on + + align:start position:0% +power series like this is convergent on + + + align:start position:0% +power series like this is convergent on +some interval and then outside this + + align:start position:0% +some interval and then outside this + + + align:start position:0% +some interval and then outside this +interval it's divergent. + + align:start position:0% +interval it's divergent. + + + align:start position:0% +interval it's divergent. +So it's not like you have some that is + + align:start position:0% +So it's not like you have some that is + + + align:start position:0% +So it's not like you have some that is +convergent here it's divergent there and + + align:start position:0% +convergent here it's divergent there and + + + align:start position:0% +convergent here it's divergent there and +then it's like converging again. Right? + + align:start position:0% +then it's like converging again. Right? + + + align:start position:0% +then it's like converging again. Right? +That's not what's going to happen. Okay, + + align:start position:0% +That's not what's going to happen. Okay, + + + align:start position:0% +That's not what's going to happen. Okay, +part of this is also we already saw this + + align:start position:0% +part of this is also we already saw this + + + align:start position:0% +part of this is also we already saw this +in the different test that there is at + + align:start position:0% +in the different test that there is at + + + align:start position:0% +in the different test that there is at +the boundary of this interval it's it's + + align:start position:0% +the boundary of this interval it's it's + + + align:start position:0% +the boundary of this interval it's it's +not it's it's the test is inconclusive. + + align:start position:0% +not it's it's the test is inconclusive. + + + align:start position:0% +not it's it's the test is inconclusive. +So you have to check the boundary + + align:start position:0% +So you have to check the boundary + + + align:start position:0% +So you have to check the boundary +separately. Okay. + + align:start position:0% +separately. Okay. + + + align:start position:0% +separately. Okay. +And so so the idea is that you take so + + align:start position:0% +And so so the idea is that you take so + + + align:start position:0% +And so so the idea is that you take so +you you have a power series like this + + align:start position:0% + + + + align:start position:0% + +and you think about again you're + + align:start position:0% +and you think about again you're + + + align:start position:0% +and you think about again you're +thinking about dn as x to the n x again + + align:start position:0% +thinking about dn as x to the n x again + + + align:start position:0% +thinking about dn as x to the n x again +is is thought of being fixed and now you + + align:start position:0% +is is thought of being fixed and now you + + + align:start position:0% +is is thought of being fixed and now you +apply the root test. So apply the root + + align:start position:0% +apply the root test. So apply the root + + + align:start position:0% +apply the root test. So apply the root +test but I'm going to apply it in a in a + + align:start position:0% +test but I'm going to apply it in a in a + + + align:start position:0% +test but I'm going to apply it in a in a +better form than what we did last time. + + align:start position:0% + + + + align:start position:0% + +Maybe I'll just state first first the + + align:start position:0% +Maybe I'll just state first first the + + + align:start position:0% +Maybe I'll just state first first the +better form of the root test. So here's + + align:start position:0% +better form of the root test. So here's + + + align:start position:0% +better form of the root test. So here's +the sort of + + align:start position:0% +the sort of + + + align:start position:0% +the sort of +um + + align:start position:0% +um + + + align:start position:0% +um +here's the the real version of the root + + align:start position:0% +here's the the real version of the root + + + align:start position:0% +here's the the real version of the root +test. + + align:start position:0% +test. + + + align:start position:0% +test. +So suppose you take a series. + + align:start position:0% +So suppose you take a series. + + + align:start position:0% +So suppose you take a series. +Suppose you have some serious here. + + align:start position:0% + + + + align:start position:0% + +This is let's call it the end. + + align:start position:0% +This is let's call it the end. + + + align:start position:0% +This is let's call it the end. +Suppose you take a series like this + + align:start position:0% + + + + align:start position:0% + +if you're looking at so now you the root + + align:start position:0% +if you're looking at so now you the root + + + align:start position:0% +if you're looking at so now you the root +test right you took dn you took the + + align:start position:0% +test right you took dn you took the + + + align:start position:0% +test right you took dn you took the +absolute value and you took the nth root + + align:start position:0% +absolute value and you took the nth root + + + align:start position:0% +absolute value and you took the nth root +right + + align:start position:0% +right + + + align:start position:0% +right +when I looked at the root test last time + + align:start position:0% +when I looked at the root test last time + + + align:start position:0% +when I looked at the root test last time +we looked at whether this is convergent + + align:start position:0% +we looked at whether this is convergent + + + align:start position:0% +we looked at whether this is convergent +or not right so we said if it was + + align:start position:0% +or not right so we said if it was + + + align:start position:0% +or not right so we said if it was +converging to something, right? But you + + align:start position:0% +converging to something, right? But you + + + align:start position:0% +converging to something, right? But you +could just take you could form this + + align:start position:0% +could just take you could form this + + + align:start position:0% +could just take you could form this +thing here. So you could form from from + + align:start position:0% +thing here. So you could form from from + + + align:start position:0% +thing here. So you could form from from +this here you could form this. This is + + align:start position:0% +this here you could form this. This is + + + align:start position:0% +this here you could form this. This is +now a sequence and you could look at lim + + align:start position:0% +now a sequence and you could look at lim + + + align:start position:0% +now a sequence and you could look at lim +soup of this. + + align:start position:0% + + + + align:start position:0% + +This these here are all non- negative + + align:start position:0% +This these here are all non- negative + + + align:start position:0% +This these here are all non- negative +numbers. Right? So um so uh and this le + + align:start position:0% +numbers. Right? So um so uh and this le + + + align:start position:0% +numbers. Right? So um so uh and this le +soup here is now going to be either + + align:start position:0% +soup here is now going to be either + + + align:start position:0% +soup here is now going to be either +infinite or it's going to be some real + + align:start position:0% +infinite or it's going to be some real + + + align:start position:0% +infinite or it's going to be some real +non- negative number right this here is + + align:start position:0% +non- negative number right this here is + + + align:start position:0% +non- negative number right this here is +going to be infinite usually we don't + + align:start position:0% +going to be infinite usually we don't + + + align:start position:0% +going to be infinite usually we don't +talk about that it's converging if it's + + align:start position:0% +talk about that it's converging if it's + + + align:start position:0% +talk about that it's converging if it's +infinite or it's it's some number + + align:start position:0% +infinite or it's it's some number + + + align:start position:0% +infinite or it's it's some number +um let's call it let's call it d I guess + + align:start position:0% +um let's call it let's call it d I guess + + + align:start position:0% +um let's call it let's call it d I guess +but + + align:start position:0% +but + + + align:start position:0% +but +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +And the thing is that if you're looking + + align:start position:0% +And the thing is that if you're looking + + + align:start position:0% +And the thing is that if you're looking +at if you set r equal to 1 /d + + align:start position:0% + + + + align:start position:0% + +right sorry no if you're setting uh if + + align:start position:0% +right sorry no if you're setting uh if + + + align:start position:0% +right sorry no if you're setting uh if +so so so this is just the root test the + + align:start position:0% +so so so this is just the root test the + + + align:start position:0% +so so so this is just the root test the +sort of adult version of the root test + + align:start position:0% +sort of adult version of the root test + + + align:start position:0% +sort of adult version of the root test +because this apply to all sequences + + align:start position:0% +because this apply to all sequences + + + align:start position:0% +because this apply to all sequences +right for any sequence you have this for + + align:start position:0% +right for any sequence you have this for + + + align:start position:0% +right for any sequence you have this for +any sequence dn if you're looking at + + align:start position:0% +any sequence dn if you're looking at + + + align:start position:0% +any sequence dn if you're looking at +this series you can look at this right + + align:start position:0% +this series you can look at this right + + + align:start position:0% +this series you can look at this right +and it's either infinity or d + + align:start position:0% +and it's either infinity or d + + + align:start position:0% +and it's either infinity or d +and then if d here is less than one then + + align:start position:0% +and then if d here is less than one then + + + align:start position:0% +and then if d here is less than one then +the series is convergent. + + align:start position:0% + + + + align:start position:0% + +If d is bigger than one, the series is + + align:start position:0% +If d is bigger than one, the series is + + + align:start position:0% +If d is bigger than one, the series is +divergent. + + align:start position:0% + + + + align:start position:0% + +And if d is equal to one, it's + + align:start position:0% +And if d is equal to one, it's + + + align:start position:0% +And if d is equal to one, it's +inconclusion, + + align:start position:0% + + + + align:start position:0% + +right? The difference between this and + + align:start position:0% +right? The difference between this and + + + align:start position:0% +right? The difference between this and +what we talked about last time was that + + align:start position:0% +what we talked about last time was that + + + align:start position:0% +what we talked about last time was that +last time we assume that this thing here + + align:start position:0% +last time we assume that this thing here + + + align:start position:0% +last time we assume that this thing here +converge here I'm not assuming it but + + align:start position:0% +converge here I'm not assuming it but + + + align:start position:0% +converge here I'm not assuming it but +I'm then I'm looking at the lem soup + + align:start position:0% +I'm then I'm looking at the lem soup + + + align:start position:0% +I'm then I'm looking at the lem soup +instead. Right? So this is does give us + + align:start position:0% +instead. Right? So this is does give us + + + align:start position:0% +instead. Right? So this is does give us +a number. + + align:start position:0% +a number. + + + align:start position:0% +a number. +Okay. And it's just a matter of whether + + align:start position:0% +Okay. And it's just a matter of whether + + + align:start position:0% +Okay. And it's just a matter of whether +the slim soup is smaller than one + + align:start position:0% +the slim soup is smaller than one + + + align:start position:0% +the slim soup is smaller than one +and then it's convergent or bigger than + + align:start position:0% +and then it's convergent or bigger than + + + align:start position:0% +and then it's convergent or bigger than +one then it's divergent. + + align:start position:0% + + + + align:start position:0% + +Okay. Now I'll come back to to the proof + + align:start position:0% +Okay. Now I'll come back to to the proof + + + align:start position:0% +Okay. Now I'll come back to to the proof +but the proof is really kind of the same + + align:start position:0% +but the proof is really kind of the same + + + align:start position:0% +but the proof is really kind of the same +as the one we gave. the one we gave + + align:start position:0% +as the one we gave. the one we gave + + + align:start position:0% +as the one we gave. the one we gave +really, you know, the if you kind of + + align:start position:0% +really, you know, the if you kind of + + + align:start position:0% +really, you know, the if you kind of +mimic what we did uh in the special case + + align:start position:0% +mimic what we did uh in the special case + + + align:start position:0% +mimic what we did uh in the special case +last time, then the proof would still + + align:start position:0% +last time, then the proof would still + + + align:start position:0% +last time, then the proof would still +apply to this case here and give this + + align:start position:0% +apply to this case here and give this + + + align:start position:0% +apply to this case here and give this +result. + + align:start position:0% +result. + + + align:start position:0% +result. +Okay. So now, but let's let's take this + + align:start position:0% +Okay. So now, but let's let's take this + + + align:start position:0% +Okay. So now, but let's let's take this +this more fancy version of uh the root + + align:start position:0% +this more fancy version of uh the root + + + align:start position:0% +this more fancy version of uh the root +test. Let's take that for granted. + + align:start position:0% + + + + align:start position:0% + +And so + + align:start position:0% +And so + + + align:start position:0% +And so +so now + + align:start position:0% +so now + + + align:start position:0% +so now +so now I have + + align:start position:0% +so now I have + + + align:start position:0% +so now I have +a power shares like this. I just for for + + align:start position:0% +a power shares like this. I just for for + + + align:start position:0% +a power shares like this. I just for for +you know for for clarity I define dn to + + align:start position:0% +you know for for clarity I define dn to + + + align:start position:0% +you know for for clarity I define dn to +be just a n + + align:start position:0% +be just a n + + + align:start position:0% +be just a n +time xn and I'm interested in is for + + align:start position:0% +time xn and I'm interested in is for + + + align:start position:0% +time xn and I'm interested in is for +what x + + align:start position:0% +what x + + + align:start position:0% +what x +for what x + + align:start position:0% + + + + align:start position:0% + +does it converge does the power series + + align:start position:0% +does it converge does the power series + + + align:start position:0% +does it converge does the power series +convert + + align:start position:0% + + + + align:start position:0% + +Okay. Now, + + align:start position:0% +Okay. Now, + + + align:start position:0% +Okay. Now, +so now you see that so lem soup. + + align:start position:0% +so now you see that so lem soup. + + + align:start position:0% +so now you see that so lem soup. +So you you were looking at lim soup of + + align:start position:0% +So you you were looking at lim soup of + + + align:start position:0% +So you you were looking at lim soup of +the nth root of d n is a n * xn + + align:start position:0% +the nth root of d n is a n * xn + + + align:start position:0% +the nth root of d n is a n * xn +and you take the absolute value of that + + align:start position:0% +and you take the absolute value of that + + + align:start position:0% +and you take the absolute value of that +right that's that's what you're looking + + align:start position:0% +right that's that's what you're looking + + + align:start position:0% +right that's that's what you're looking +at and you asking is this smaller than + + align:start position:0% +at and you asking is this smaller than + + + align:start position:0% +at and you asking is this smaller than +one or bigger than one + + align:start position:0% +one or bigger than one + + + align:start position:0% +one or bigger than one +but this thing here + + align:start position:0% +but this thing here + + + align:start position:0% +but this thing here +right this is the same as sou right if + + align:start position:0% +right this is the same as sou right if + + + align:start position:0% +right this is the same as sou right if +you're looking at this thing here let's + + align:start position:0% +you're looking at this thing here let's + + + align:start position:0% +you're looking at this thing here let's +do a + + align:start position:0% +do a + + + align:start position:0% +do a +side calculation. If you're looking at + + align:start position:0% +side calculation. If you're looking at + + + align:start position:0% +side calculation. If you're looking at +the nth root + + align:start position:0% +the nth root + + + align:start position:0% +the nth root +of uh a n * xn, + + align:start position:0% +of uh a n * xn, + + + align:start position:0% +of uh a n * xn, +this thing here is the same as the nth + + align:start position:0% +this thing here is the same as the nth + + + align:start position:0% +this thing here is the same as the nth +root of this product here. Absolute + + align:start position:0% +root of this product here. Absolute + + + align:start position:0% +root of this product here. Absolute +value is the same as this times x + + align:start position:0% +value is the same as this times x + + + align:start position:0% +value is the same as this times x +absolute value to the n. + + align:start position:0% +absolute value to the n. + + + align:start position:0% +absolute value to the n. +And when you take the nth root, you may + + align:start position:0% +And when you take the nth root, you may + + + align:start position:0% +And when you take the nth root, you may +as well take the nth root of each of + + align:start position:0% +as well take the nth root of each of + + + align:start position:0% +as well take the nth root of each of +those two factors individually. + + align:start position:0% +those two factors individually. + + + align:start position:0% +those two factors individually. +So this is what you get. + + align:start position:0% + + + + align:start position:0% + +But this thing here, you see this thing + + align:start position:0% +But this thing here, you see this thing + + + align:start position:0% +But this thing here, you see this thing +here, the end root, this here is + + align:start position:0% +here, the end root, this here is + + + align:start position:0% +here, the end root, this here is +whatever it is. + + align:start position:0% +whatever it is. + + + align:start position:0% +whatever it is. +Can't do much about that. + + align:start position:0% +Can't do much about that. + + + align:start position:0% +Can't do much about that. +But this thing here, that's just the + + align:start position:0% +But this thing here, that's just the + + + align:start position:0% +But this thing here, that's just the +norm of x, right? The norm of x has the + + align:start position:0% +norm of x, right? The norm of x has the + + + align:start position:0% +norm of x, right? The norm of x has the +property that when you raise it to the n + + align:start position:0% +property that when you raise it to the n + + + align:start position:0% +property that when you raise it to the n +power you're getting this right. So this + + align:start position:0% +power you're getting this right. So this + + + align:start position:0% +power you're getting this right. So this +is the end. + + align:start position:0% +is the end. + + + align:start position:0% +is the end. +Okay. So this means that this thing here + + align:start position:0% +Okay. So this means that this thing here + + + align:start position:0% +Okay. So this means that this thing here +is the same as the norm of x limb soup + + align:start position:0% +is the same as the norm of x limb soup + + + align:start position:0% +is the same as the norm of x limb soup +of the nth root of a n. + + align:start position:0% +of the nth root of a n. + + + align:start position:0% +of the nth root of a n. +Right? + + align:start position:0% +Right? + + + align:start position:0% +Right? +Often you do it like this. You don't + + align:start position:0% +Often you do it like this. You don't + + + align:start position:0% +Often you do it like this. You don't +have to do this. It's usually clear + + align:start position:0% +have to do this. It's usually clear + + + align:start position:0% +have to do this. It's usually clear +anyway. But it off you write like that. + + align:start position:0% +anyway. But it off you write like that. + + + align:start position:0% +anyway. But it off you write like that. +Okay. So now what you do is so you you + + align:start position:0% +Okay. So now what you do is so you you + + + align:start position:0% +Okay. So now what you do is so you you +want you asking when is this number here + + align:start position:0% +want you asking when is this number here + + + align:start position:0% +want you asking when is this number here +smaller than one when is it bigger than + + align:start position:0% +smaller than one when is it bigger than + + + align:start position:0% +smaller than one when is it bigger than +one right? And so you have that you see + + align:start position:0% +one right? And so you have that you see + + + align:start position:0% +one right? And so you have that you see +now you define something that's called + + align:start position:0% +now you define something that's called + + + align:start position:0% +now you define something that's called +the radius of convergence. + + align:start position:0% +the radius of convergence. + + + align:start position:0% +the radius of convergence. +And so this is the following. So the + + align:start position:0% +And so this is the following. So the + + + align:start position:0% +And so this is the following. So the +radius of convergence + + align:start position:0% +radius of convergence + + + align:start position:0% +radius of convergence +is oops + + align:start position:0% +is oops + + + align:start position:0% +is oops +radius of convergence is + + align:start position:0% +radius of convergence is + + + align:start position:0% +radius of convergence is +so this is just radius + + align:start position:0% +so this is just radius + + + align:start position:0% +so this is just radius +of convergent. + + align:start position:0% +of convergent. + + + align:start position:0% +of convergent. +The radius of convergence is just a + + align:start position:0% +The radius of convergence is just a + + + align:start position:0% +The radius of convergence is just a +number + + align:start position:0% + + + + align:start position:0% + +and that number is radius of convergence + + align:start position:0% +and that number is radius of convergence + + + align:start position:0% +and that number is radius of convergence +and we have to just interpret it a + + align:start position:0% +and we have to just interpret it a + + + align:start position:0% +and we have to just interpret it a +little bit. So it's one over lim super + + align:start position:0% +little bit. So it's one over lim super + + + align:start position:0% +little bit. So it's one over lim super +of of the nth root. + + align:start position:0% + + + + align:start position:0% + +This thing here could of course be + + align:start position:0% +This thing here could of course be + + + align:start position:0% +This thing here could of course be +infinite. + + align:start position:0% +infinite. + + + align:start position:0% +infinite. +If this here is infinite then the radius + + align:start position:0% +If this here is infinite then the radius + + + align:start position:0% +If this here is infinite then the radius +by definition this here would be zero. + + align:start position:0% +by definition this here would be zero. + + + align:start position:0% +by definition this here would be zero. +Right? Right? Where this here is equal + + align:start position:0% +Right? Right? Where this here is equal + + + align:start position:0% +Right? Right? Where this here is equal +to zero. If + + align:start position:0% +to zero. If + + + align:start position:0% +to zero. If +there's lean soup uh + + align:start position:0% + + + + align:start position:0% + +is infinite and otherwise right it's a + + align:start position:0% +is infinite and otherwise right it's a + + + align:start position:0% +is infinite and otherwise right it's a +it's always a right otherwise yeah + + align:start position:0% +it's always a right otherwise yeah + + + align:start position:0% +it's always a right otherwise yeah +there's one other case you have to + + align:start position:0% +there's one other case you have to + + + align:start position:0% +there's one other case you have to +define that if uh it's infinite if the + + align:start position:0% +define that if uh it's infinite if the + + + align:start position:0% +define that if uh it's infinite if the +lem soup + + align:start position:0% +lem soup + + + align:start position:0% +lem soup +sorry this should be absolute value if + + align:start position:0% +sorry this should be absolute value if + + + align:start position:0% +sorry this should be absolute value if +this lem soup + + align:start position:0% +this lem soup + + + align:start position:0% +this lem soup +is true and otherwise otherwise it's a + + align:start position:0% +is true and otherwise otherwise it's a + + + align:start position:0% +is true and otherwise otherwise it's a +you know otherwise there's nothing to + + align:start position:0% +you know otherwise there's nothing to + + + align:start position:0% +you know otherwise there's nothing to +you know it's a well you know that's the + + align:start position:0% +you know it's a well you know that's the + + + align:start position:0% +you know it's a well you know that's the +only thing you have to comment right + + align:start position:0% +only thing you have to comment right + + + align:start position:0% +only thing you have to comment right +because otherwise it's it's it's always + + align:start position:0% +because otherwise it's it's it's always + + + align:start position:0% +because otherwise it's it's it's always +a non- negative number but it could be + + align:start position:0% +a non- negative number but it could be + + + align:start position:0% +a non- negative number but it could be +zero or it could be infinity but if it's + + align:start position:0% +zero or it could be infinity but if it's + + + align:start position:0% +zero or it could be infinity but if it's +any other number then it is just what + + align:start position:0% +any other number then it is just what + + + align:start position:0% +any other number then it is just what +you think it should be is one over that + + align:start position:0% +you think it should be is one over that + + + align:start position:0% +you think it should be is one over that +number + + align:start position:0% +number + + + align:start position:0% +number +okay so this gives you this is this here + + align:start position:0% +okay so this gives you this is this here + + + align:start position:0% +okay so this gives you this is this here +r here is the radius of convergence okay + + align:start position:0% +r here is the radius of convergence okay + + + align:start position:0% +r here is the radius of convergence okay +and Now the the thing is that now we + + align:start position:0% +and Now the the thing is that now we + + + align:start position:0% +and Now the the thing is that now we +have the following symbol picture. + + align:start position:0% + + + + align:start position:0% + +So now we have that. So you have this + + align:start position:0% +So now we have that. So you have this + + + align:start position:0% +So now we have that. So you have this +power series + + align:start position:0% + + + + align:start position:0% + +again it doesn't matter what you start + + align:start position:0% +again it doesn't matter what you start + + + align:start position:0% +again it doesn't matter what you start +with the sum matters what you start with + + align:start position:0% +with the sum matters what you start with + + + align:start position:0% +with the sum matters what you start with +but not the convergence. So you have + + align:start position:0% +but not the convergence. So you have + + + align:start position:0% +but not the convergence. So you have +this power series you are forming a + + align:start position:0% +this power series you are forming a + + + align:start position:0% +this power series you are forming a +This is the radius of convergence. + + align:start position:0% + + + + align:start position:0% + +And then the claim is and again this + + align:start position:0% +And then the claim is and again this + + + align:start position:0% +And then the claim is and again this +could be zero it could be infinity but + + align:start position:0% +could be zero it could be infinity but + + + align:start position:0% +could be zero it could be infinity but +often it's just a a real number non- + + align:start position:0% +often it's just a a real number non- + + + align:start position:0% +often it's just a a real number non- +negative real positive real number and + + align:start position:0% +negative real positive real number and + + + align:start position:0% +negative real positive real number and +so it say that if you take the interval + + align:start position:0% +so it say that if you take the interval + + + align:start position:0% +so it say that if you take the interval +here around zero in the interval + + align:start position:0% +here around zero in the interval + + + align:start position:0% +here around zero in the interval +from minus r to r then inside this + + align:start position:0% +from minus r to r then inside this + + + align:start position:0% +from minus r to r then inside this +interval here inside here when x is in + + align:start position:0% +interval here inside here when x is in + + + align:start position:0% +interval here inside here when x is in +here then the Power series + + align:start position:0% + + + + align:start position:0% + +is convergent + + align:start position:0% + + + + align:start position:0% + +and when X is here or here + + align:start position:0% + + + + align:start position:0% + +power series is divergent + + align:start position:0% + + + + align:start position:0% + +and then when X's is here or here at + + align:start position:0% +and then when X's is here or here at + + + align:start position:0% +and then when X's is here or here at +those two points then it's and clear and + + align:start position:0% +those two points then it's and clear and + + + align:start position:0% +those two points then it's and clear and +further test is needed. + + align:start position:0% +further test is needed. + + + align:start position:0% +further test is needed. +Further test is needed. + + align:start position:0% + + + + align:start position:0% + +Test are needed. + + align:start position:0% + + + + align:start position:0% + +>> Okay. + + align:start position:0% +>> Okay. + + + align:start position:0% +>> Okay. +>> Yeah. + + align:start position:0% + + + + align:start position:0% + +less than one. + + align:start position:0% +less than one. + + + align:start position:0% +less than one. +>> Yeah. So that's right. So so let's come + + align:start position:0% +>> Yeah. So that's right. So so let's come + + + align:start position:0% +>> Yeah. So that's right. So so let's come +to the proof. Yeah. So this is what + + align:start position:0% +to the proof. Yeah. So this is what + + + align:start position:0% +to the proof. Yeah. So this is what +you're talking about. So + + align:start position:0% +you're talking about. So + + + align:start position:0% +you're talking about. So +So this is this is the the radius of + + align:start position:0% +So this is this is the the radius of + + + align:start position:0% +So this is this is the the radius of +convergence, right? And so as you say + + align:start position:0% +convergence, right? And so as you say + + + align:start position:0% +convergence, right? And so as you say +um all we need to do is right but we + + align:start position:0% +um all we need to do is right but we + + + align:start position:0% +um all we need to do is right but we +know from this from the more fancy + + align:start position:0% +know from this from the more fancy + + + align:start position:0% +know from this from the more fancy +version of the ratio test that is in + + align:start position:0% +version of the ratio test that is in + + + align:start position:0% +version of the ratio test that is in +terms of leap soup we know that so so + + align:start position:0% +terms of leap soup we know that so so + + + align:start position:0% +terms of leap soup we know that so so +prove here + + align:start position:0% +prove here + + + align:start position:0% +prove here +power series is convergent by the ratio + + align:start position:0% +power series is convergent by the ratio + + + align:start position:0% +power series is convergent by the ratio +test by the by the ratio test, + + align:start position:0% + + + + align:start position:0% + +not a ratio test. Sorry, the root test + + align:start position:0% +not a ratio test. Sorry, the root test + + + align:start position:0% +not a ratio test. Sorry, the root test +by the root test. + + align:start position:0% +by the root test. + + + align:start position:0% +by the root test. +So again, the version the version the + + align:start position:0% +So again, the version the version the + + + align:start position:0% +So again, the version the version the +lem soup version, + + align:start position:0% +lem soup version, + + + align:start position:0% +lem soup version, +not the one I talked about last time, + + align:start position:0% +not the one I talked about last time, + + + align:start position:0% +not the one I talked about last time, +but this one we just talked about, but + + align:start position:0% +but this one we just talked about, but + + + align:start position:0% +but this one we just talked about, but +the lem soup version of the ratio root + + align:start position:0% +the lem soup version of the ratio root + + + align:start position:0% +the lem soup version of the ratio root +test, + + align:start position:0% +test, + + + align:start position:0% +test, +then the power series is converging. If + + align:start position:0% +then the power series is converging. If + + + align:start position:0% +then the power series is converging. If +this thing here, so this means that this + + align:start position:0% +this thing here, so this means that this + + + align:start position:0% +this thing here, so this means that this +thing here. So if this thing here + + align:start position:0% + + + + align:start position:0% + +li + + align:start position:0% +li + + + align:start position:0% +li +of a nth + + align:start position:0% +of a nth + + + align:start position:0% +of a nth +root + + align:start position:0% +root + + + align:start position:0% +root +if this thing here is less than one, + + align:start position:0% +if this thing here is less than one, + + + align:start position:0% +if this thing here is less than one, +it's divergent. + + align:start position:0% +it's divergent. + + + align:start position:0% +it's divergent. +If this thing here + + align:start position:0% + + + + align:start position:0% + +is bigger than one and it's inconclusive + + align:start position:0% +is bigger than one and it's inconclusive + + + align:start position:0% +is bigger than one and it's inconclusive +and it's and it's inconclusive if this + + align:start position:0% +and it's and it's inconclusive if this + + + align:start position:0% +and it's and it's inconclusive if this +thing here + + align:start position:0% + + + + align:start position:0% + +is equal to one here it's inconclusive. + + align:start position:0% + + + + align:start position:0% + +But now you see that this here this here + + align:start position:0% +But now you see that this here this here + + + align:start position:0% +But now you see that this here this here +just means that the norm of X should be + + align:start position:0% +just means that the norm of X should be + + + align:start position:0% +just means that the norm of X should be +smaller than one over that. Right? So + + align:start position:0% +smaller than one over that. Right? So + + + align:start position:0% +smaller than one over that. Right? So +this here is is is + + align:start position:0% +this here is is is + + + align:start position:0% +this here is is is +the same as saying that the norm of X is + + align:start position:0% +the same as saying that the norm of X is + + + align:start position:0% +the same as saying that the norm of X is +smaller than R the radius of + + align:start position:0% +smaller than R the radius of + + + align:start position:0% +smaller than R the radius of +convergence. Right? + + align:start position:0% +convergence. Right? + + + align:start position:0% +convergence. Right? +This here is saying this is equivalent + + align:start position:0% +This here is saying this is equivalent + + + align:start position:0% +This here is saying this is equivalent +to saying that the norm of x is bigger + + align:start position:0% +to saying that the norm of x is bigger + + + align:start position:0% +to saying that the norm of x is bigger +than uh than r + + align:start position:0% +than uh than r + + + align:start position:0% +than uh than r +right and this here is equivalent to + + align:start position:0% +right and this here is equivalent to + + + align:start position:0% +right and this here is equivalent to +saying that the norm of x is equal to r. + + align:start position:0% + + + + align:start position:0% + +Okay. So so that is the that is the so + + align:start position:0% +Okay. So so that is the that is the so + + + align:start position:0% +Okay. So so that is the that is the so +that's a radius of convergence. So you + + align:start position:0% +that's a radius of convergence. So you + + + align:start position:0% +that's a radius of convergence. So you +see so this is like you know a pure this + + align:start position:0% +see so this is like you know a pure this + + + align:start position:0% +see so this is like you know a pure this +is not at all clear + + align:start position:0% +is not at all clear + + + align:start position:0% +is not at all clear +that it couldn't be that a power series + + align:start position:0% +that it couldn't be that a power series + + + align:start position:0% +that it couldn't be that a power series +couldn't be convergent for like you know + + align:start position:0% +couldn't be convergent for like you know + + + align:start position:0% +couldn't be convergent for like you know +some sort of discrete set of of x but + + align:start position:0% +some sort of discrete set of of x but + + + align:start position:0% +some sort of discrete set of of x but +that's not the case right it's it's + + align:start position:0% +that's not the case right it's it's + + + align:start position:0% +that's not the case right it's it's +convergent on some interval it's unclear + + align:start position:0% +convergent on some interval it's unclear + + + align:start position:0% +convergent on some interval it's unclear +at the at the end of that interval but + + align:start position:0% +at the at the end of that interval but + + + align:start position:0% +at the at the end of that interval but +it is convergence on an interval and + + align:start position:0% +it is convergence on an interval and + + + align:start position:0% +it is convergence on an interval and +divergent outside that interval now that + + align:start position:0% +divergent outside that interval now that + + + align:start position:0% +divergent outside that interval now that +interval could be just zero + + align:start position:0% +interval could be just zero + + + align:start position:0% +interval could be just zero +Or it could be all of R. Right. + + align:start position:0% +Or it could be all of R. Right. + + + align:start position:0% +Or it could be all of R. Right. +But it is also symmetric around zero. + + align:start position:0% +But it is also symmetric around zero. + + + align:start position:0% +But it is also symmetric around zero. +Yeah. + + align:start position:0% + + + + align:start position:0% + +>> Right. So it's so it's one over this + + align:start position:0% +>> Right. So it's so it's one over this + + + align:start position:0% +>> Right. So it's so it's one over this +here. But remember how R was defined. R + + align:start position:0% +here. But remember how R was defined. R + + + align:start position:0% +here. But remember how R was defined. R +is up there. + + align:start position:0% +is up there. + + + align:start position:0% +is up there. +>> Yeah. + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +Now + + align:start position:0% +Now + + + align:start position:0% +Now +um let me just say a word + + align:start position:0% +um let me just say a word + + + align:start position:0% +um let me just say a word +about why does the proof from last time + + align:start position:0% +about why does the proof from last time + + + align:start position:0% +about why does the proof from last time +why does it really prove this more you + + align:start position:0% +why does it really prove this more you + + + align:start position:0% +why does it really prove this more you +know I mean the sort of argument we gave + + align:start position:0% +know I mean the sort of argument we gave + + + align:start position:0% +know I mean the sort of argument we gave +last time + + align:start position:0% +last time + + + align:start position:0% +last time +why does it give you this much more sat + + align:start position:0% +why does it give you this much more sat + + + align:start position:0% +why does it give you this much more sat +I mean it's much more satisfying this + + align:start position:0% +I mean it's much more satisfying this + + + align:start position:0% +I mean it's much more satisfying this +version of the root test because it + + align:start position:0% +version of the root test because it + + + align:start position:0% +version of the root test because it +apply to any series right the because + + align:start position:0% +apply to any series right the because + + + align:start position:0% +apply to any series right the because +otherwise we talk about whether some + + align:start position:0% +otherwise we talk about whether some + + + align:start position:0% +otherwise we talk about whether some +ratio was convergent but it may not + + align:start position:0% +ratio was convergent but it may not + + + align:start position:0% +ratio was convergent but it may not +converge right so this is much more + + align:start position:0% +converge right so this is much more + + + align:start position:0% +converge right so this is much more +satisfying so suppose again you have a + + align:start position:0% +satisfying so suppose again you have a + + + align:start position:0% +satisfying so suppose again you have a +series like this + + align:start position:0% +series like this + + + align:start position:0% +series like this +and so now you form you're looking at + + align:start position:0% +and so now you form you're looking at + + + align:start position:0% +and so now you form you're looking at +lem soup so this here is again this is + + align:start position:0% +lem soup so this here is again this is + + + align:start position:0% +lem soup so this here is again this is +the root test + + align:start position:0% +the root test + + + align:start position:0% +the root test +root + + align:start position:0% +root + + + align:start position:0% +root +test + + align:start position:0% +test + + + align:start position:0% +test +version, let's call it version 2.0, + + align:start position:0% + + + + align:start position:0% + +right? And so it take um series like + + align:start position:0% +right? And so it take um series like + + + align:start position:0% +right? And so it take um series like +this and it's + + align:start position:0% +this and it's + + + align:start position:0% +this and it's +it's looking at le soup and then the nth + + align:start position:0% +it's looking at le soup and then the nth + + + align:start position:0% +it's looking at le soup and then the nth +root of the absolute value of dn + + align:start position:0% + + + + align:start position:0% + +and again it say that if this thing here + + align:start position:0% +and again it say that if this thing here + + + align:start position:0% +and again it say that if this thing here +is e is less than one it's convergent. + + align:start position:0% + + + + align:start position:0% + +If it's bigger than one, it's diverging + + align:start position:0% + + + + align:start position:0% + +and if it's equal to one, it's + + align:start position:0% +and if it's equal to one, it's + + + align:start position:0% +and if it's equal to one, it's +inconclusion. + + align:start position:0% + + + + align:start position:0% + +Okay. Now let's let's try to see why + + align:start position:0% +Okay. Now let's let's try to see why + + + align:start position:0% +Okay. Now let's let's try to see why +this here why this here is the case. So + + align:start position:0% +this here why this here is the case. So + + + align:start position:0% +this here why this here is the case. So +proof of + + align:start position:0% + + + + align:start position:0% + +of root test + + align:start position:0% + + + + align:start position:0% + +version 2.0. + + align:start position:0% + + + + align:start position:0% + +So now may maybe I won't do all of it + + align:start position:0% +So now may maybe I won't do all of it + + + align:start position:0% +So now may maybe I won't do all of it +but let's just say let's just look at + + align:start position:0% +but let's just say let's just look at + + + align:start position:0% +but let's just say let's just look at +because you see in a minute you see that + + align:start position:0% +because you see in a minute you see that + + + align:start position:0% +because you see in a minute you see that +it's really kind of super similar to + + align:start position:0% +it's really kind of super similar to + + + align:start position:0% +it's really kind of super similar to +last time. So suppose that this limit + + align:start position:0% +last time. So suppose that this limit + + + align:start position:0% +last time. So suppose that this limit +suppose + + align:start position:0% + + + + align:start position:0% + +that this limb soup + + align:start position:0% + + + + align:start position:0% + +of the nth root here of dn suppos + + align:start position:0% +of the nth root here of dn suppos + + + align:start position:0% +of the nth root here of dn suppos +supposed that this thing here + + align:start position:0% +supposed that this thing here + + + align:start position:0% +supposed that this thing here +is equal to some d which is strictly + + align:start position:0% +is equal to some d which is strictly + + + align:start position:0% +is equal to some d which is strictly +less than one. + + align:start position:0% +less than one. + + + align:start position:0% +less than one. +Okay. So this means that there exist + + align:start position:0% + + + + align:start position:0% + +uh + + align:start position:0% +uh + + + align:start position:0% +uh +they exist. + + align:start position:0% +they exist. + + + align:start position:0% +they exist. +So choose if you will choose + + align:start position:0% + + + + align:start position:0% + +uh d + + align:start position:0% +uh d + + + align:start position:0% +uh d +bar + + align:start position:0% +bar + + + align:start position:0% +bar +will + + align:start position:0% +will + + + align:start position:0% +will +uh d less than d bar strictly less than + + align:start position:0% +uh d less than d bar strictly less than + + + align:start position:0% +uh d less than d bar strictly less than +strictly less than one. + + align:start position:0% +strictly less than one. + + + align:start position:0% +strictly less than one. +Right? So I can choose it like this. + + align:start position:0% + + + + align:start position:0% + +But now you see that if I choose it like + + align:start position:0% +But now you see that if I choose it like + + + align:start position:0% +But now you see that if I choose it like +this then there exist + + align:start position:0% + + + + align:start position:0% + +that so remember that let's just remind + + align:start position:0% +that so remember that let's just remind + + + align:start position:0% +that so remember that let's just remind +ourselves that + + align:start position:0% +ourselves that + + + align:start position:0% +ourselves that +how was the lim soup defined + + align:start position:0% +how was the lim soup defined + + + align:start position:0% +how was the lim soup defined +the limb soup was defined + + align:start position:0% +the limb soup was defined + + + align:start position:0% +the limb soup was defined +to be + + align:start position:0% +to be + + + align:start position:0% +to be +that you take this new sequence so + + align:start position:0% +that you take this new sequence so + + + align:start position:0% +that you take this new sequence so +you're taking this sequence here + + align:start position:0% +you're taking this sequence here + + + align:start position:0% +you're taking this sequence here +to You're taking + + align:start position:0% +to You're taking + + + align:start position:0% +to You're taking +these guys here. + + align:start position:0% +these guys here. + + + align:start position:0% +these guys here. +So you're looking at now these guys here + + align:start position:0% +So you're looking at now these guys here + + + align:start position:0% +So you're looking at now these guys here +and you are taking a you define a + + align:start position:0% +and you are taking a you define a + + + align:start position:0% +and you are taking a you define a +sequence that is like the soup starting + + align:start position:0% +sequence that is like the soup starting + + + align:start position:0% +sequence that is like the soup starting +at the nth guy + + align:start position:0% +at the nth guy + + + align:start position:0% +at the nth guy +and like this here. + + align:start position:0% +and like this here. + + + align:start position:0% +and like this here. +Sorry this here is n plus one + + align:start position:0% +Sorry this here is n plus one + + + align:start position:0% +Sorry this here is n plus one +etc. Right. + + align:start position:0% +etc. Right. + + + align:start position:0% +etc. Right. +Right. This is the soup of the tail, + + align:start position:0% +Right. This is the soup of the tail, + + + align:start position:0% +Right. This is the soup of the tail, +right? And so this was this was that it + + align:start position:0% +right? And so this was this was that it + + + align:start position:0% +right? And so this was this was that it +was soup on as you're going further out, + + align:start position:0% +was soup on as you're going further out, + + + align:start position:0% +was soup on as you're going further out, +you're taking soup over a smaller set. + + align:start position:0% +you're taking soup over a smaller set. + + + align:start position:0% +you're taking soup over a smaller set. +So these this sequence going down, + + align:start position:0% +So these this sequence going down, + + + align:start position:0% +So these this sequence going down, +right? So now if this limit here is some + + align:start position:0% +right? So now if this limit here is some + + + align:start position:0% +right? So now if this limit here is some +D which is strictly less than D bar then + + align:start position:0% +D which is strictly less than D bar then + + + align:start position:0% +D which is strictly less than D bar then +it means that there exist so there exist + + align:start position:0% + + + + align:start position:0% + +capital N. So that if little n is bigger + + align:start position:0% +capital N. So that if little n is bigger + + + align:start position:0% +capital N. So that if little n is bigger +than capital n then all of these guys + + align:start position:0% +than capital n then all of these guys + + + align:start position:0% +than capital n then all of these guys +here is less than d bar. Right? So this + + align:start position:0% +here is less than d bar. Right? So this + + + align:start position:0% +here is less than d bar. Right? So this +here is so that so if this here then all + + align:start position:0% +here is so that so if this here then all + + + align:start position:0% +here is so that so if this here then all +of these guys here is less or equal to d + + align:start position:0% +of these guys here is less or equal to d + + + align:start position:0% +of these guys here is less or equal to d +bar this is if little n if you starting + + align:start position:0% +bar this is if little n if you starting + + + align:start position:0% +bar this is if little n if you starting +that far out right + + align:start position:0% +that far out right + + + align:start position:0% +that far out right +but so now you see that so you have that + + align:start position:0% +but so now you see that so you have that + + + align:start position:0% +but so now you see that so you have that +when n is bigger than this you have that + + align:start position:0% +when n is bigger than this you have that + + + align:start position:0% +when n is bigger than this you have that +this so you have that for all these guys + + align:start position:0% +this so you have that for all these guys + + + align:start position:0% +this so you have that for all these guys +here dn the nth root is less then d bar + + align:start position:0% +here dn the nth root is less then d bar + + + align:start position:0% +here dn the nth root is less then d bar +less or equal to d bar. + + align:start position:0% +less or equal to d bar. + + + align:start position:0% +less or equal to d bar. +But now you take the nth root the nth + + align:start position:0% +But now you take the nth root the nth + + + align:start position:0% +But now you take the nth root the nth +power on both sides. So you have that dn + + align:start position:0% +power on both sides. So you have that dn + + + align:start position:0% +power on both sides. So you have that dn +absolute value is less than d bar the n + + align:start position:0% +absolute value is less than d bar the n + + + align:start position:0% +absolute value is less than d bar the n +power. This here is d is is and n is + + align:start position:0% +power. This here is d is is and n is + + + align:start position:0% +power. This here is d is is and n is +this is even actually not negative. So + + align:start position:0% +this is even actually not negative. So + + + align:start position:0% +this is even actually not negative. So +you don't even need this absolute value + + align:start position:0% +you don't even need this absolute value + + + align:start position:0% +you don't even need this absolute value +sign. So you're having this but this is + + align:start position:0% +sign. So you're having this but this is + + + align:start position:0% +sign. So you're having this but this is +a number that is strictly less than one. + + align:start position:0% +a number that is strictly less than one. + + + align:start position:0% +a number that is strictly less than one. +So this here is a geometric series right + + align:start position:0% +So this here is a geometric series right + + + align:start position:0% +So this here is a geometric series right +geometric series + + align:start position:0% + + + + align:start position:0% + +with where where where + + align:start position:0% +with where where where + + + align:start position:0% +with where where where +d bar is less than one. So it's is a + + align:start position:0% +d bar is less than one. So it's is a + + + align:start position:0% +d bar is less than one. So it's is a +convergent geometric series. Right? So + + align:start position:0% +convergent geometric series. Right? So + + + align:start position:0% +convergent geometric series. Right? So +this is you see that it was it's + + align:start position:0% +this is you see that it was it's + + + align:start position:0% +this is you see that it was it's +basically the same proof we did last + + align:start position:0% +basically the same proof we did last + + + align:start position:0% +basically the same proof we did last +time but last time we were assuming that + + align:start position:0% +time but last time we were assuming that + + + align:start position:0% +time but last time we were assuming that +some ratio was convert you know or some + + align:start position:0% +some ratio was convert you know or some + + + align:start position:0% +some ratio was convert you know or some +we were consuming assuming that this + + align:start position:0% +we were consuming assuming that this + + + align:start position:0% +we were consuming assuming that this +this here converge to something but you + + align:start position:0% +this here converge to something but you + + + align:start position:0% +this here converge to something but you +don't need it to converge you just need + + align:start position:0% +don't need it to converge you just need + + + align:start position:0% +don't need it to converge you just need +that this soup is is um is is less than + + align:start position:0% +that this soup is is um is is less than + + + align:start position:0% +that this soup is is um is is less than +one + + align:start position:0% +one + + + align:start position:0% +one +and so likewise if you examine what this + + align:start position:0% +and so likewise if you examine what this + + + align:start position:0% +and so likewise if you examine what this +case here say then just like last time + + align:start position:0% +case here say then just like last time + + + align:start position:0% +case here say then just like last time +it's going to say that if this here is + + align:start position:0% +it's going to say that if this here is + + + align:start position:0% +it's going to say that if this here is +bigger than one then the ordinary + + align:start position:0% +bigger than one then the ordinary + + + align:start position:0% +bigger than one then the ordinary +element doesn't even go to zero. Okay. + + align:start position:0% +element doesn't even go to zero. Okay. + + + align:start position:0% +element doesn't even go to zero. Okay. +So it it fails the most basic test for + + align:start position:0% +So it it fails the most basic test for + + + align:start position:0% +So it it fails the most basic test for +being convergent. Okay. So and that was + + align:start position:0% +being convergent. Okay. So and that was + + + align:start position:0% +being convergent. Okay. So and that was +just like last time also and and again + + align:start position:0% +just like last time also and and again + + + align:start position:0% +just like last time also and and again +the advantage is saying you were the one + + align:start position:0% +the advantage is saying you were the one + + + align:start position:0% +the advantage is saying you were the one +that was asking yesterday. Yeah. I mean + + align:start position:0% +that was asking yesterday. Yeah. I mean + + + align:start position:0% +that was asking yesterday. Yeah. I mean +like last time this with a ratio test + + align:start position:0% +like last time this with a ratio test + + + align:start position:0% +like last time this with a ratio test +and the root test and and like in the + + align:start position:0% +and the root test and and like in the + + + align:start position:0% +and the root test and and like in the +ratio test it's something about that the + + align:start position:0% +ratio test it's something about that the + + + align:start position:0% +ratio test it's something about that the +next element is some you know is going + + align:start position:0% +next element is some you know is going + + + align:start position:0% +next element is some you know is going +down with some fraction right and here + + align:start position:0% +down with some fraction right and here + + + align:start position:0% +down with some fraction right and here +and you very much see that like this + + align:start position:0% +and you very much see that like this + + + align:start position:0% +and you very much see that like this +here works for all series right and it's + + align:start position:0% +here works for all series right and it's + + + align:start position:0% +here works for all series right and it's +really just because you don't compare + + align:start position:0% +really just because you don't compare + + + align:start position:0% +really just because you don't compare +the element to the next but you're + + align:start position:0% +the element to the next but you're + + + align:start position:0% +the element to the next but you're +comparing it to this fixed um + + align:start position:0% +comparing it to this fixed um + + + align:start position:0% +comparing it to this fixed um +series which is a geometric is + + align:start position:0% +series which is a geometric is + + + align:start position:0% +series which is a geometric is +okay. + + align:start position:0% +okay. + + + align:start position:0% +okay. +So that's that's like the + + align:start position:0% +So that's that's like the + + + align:start position:0% +So that's that's like the +uh that's the the the the real version + + align:start position:0% +uh that's the the the the real version + + + align:start position:0% +uh that's the the the the real version +uh so to speak of the of the boot test. + + align:start position:0% +uh so to speak of the of the boot test. + + + align:start position:0% +uh so to speak of the of the boot test. +So now let's + + align:start position:0% +So now let's + + + align:start position:0% +So now let's +let's talk a little bit more about power + + align:start position:0% +let's talk a little bit more about power + + + align:start position:0% +let's talk a little bit more about power +series. + + align:start position:0% +series. + + + align:start position:0% +series. +So + + align:start position:0% + + + + align:start position:0% + +and I want to talk about so like there's + + align:start position:0% +and I want to talk about so like there's + + + align:start position:0% +and I want to talk about so like there's +one function that is particular + + align:start position:0% +one function that is particular + + + align:start position:0% +one function that is particular +important + + align:start position:0% +important + + + align:start position:0% +important +and I mean like all of these sort of + + align:start position:0% +and I mean like all of these sort of + + + align:start position:0% +and I mean like all of these sort of +basic functions are of course important + + align:start position:0% +basic functions are of course important + + + align:start position:0% +basic functions are of course important +but they are somewhat similar and uh the + + align:start position:0% +but they are somewhat similar and uh the + + + align:start position:0% +but they are somewhat similar and uh the +one I want to talk about is the + + align:start position:0% +one I want to talk about is the + + + align:start position:0% +one I want to talk about is the +exponential function + + align:start position:0% + + + + align:start position:0% + +And and there's various way that you + + align:start position:0% +And and there's various way that you + + + align:start position:0% +And and there's various way that you +could define so what is the exponential + + align:start position:0% +could define so what is the exponential + + + align:start position:0% +could define so what is the exponential +function? There's various ways that you + + align:start position:0% +function? There's various ways that you + + + align:start position:0% +function? There's various ways that you +could define the exponential function. + + align:start position:0% +could define the exponential function. + + + align:start position:0% +could define the exponential function. +You can define it, you know, like two + + align:start position:0% +You can define it, you know, like two + + + align:start position:0% +You can define it, you know, like two +that comes to mind, but there's others + + align:start position:0% +that comes to mind, but there's others + + + align:start position:0% +that comes to mind, but there's others +too. One is that you could define it to + + align:start position:0% +too. One is that you could define it to + + + align:start position:0% +too. One is that you could define it to +be a function that's satisfying a + + align:start position:0% +be a function that's satisfying a + + + align:start position:0% +be a function that's satisfying a +certain differential equation and that + + align:start position:0% +certain differential equation and that + + + align:start position:0% +certain differential equation and that +would be a good way of defining it. + + align:start position:0% +would be a good way of defining it. + + + align:start position:0% +would be a good way of defining it. +Another way of defining it which is more + + align:start position:0% +Another way of defining it which is more + + + align:start position:0% +Another way of defining it which is more +relevant to what we're doing here is + + align:start position:0% +relevant to what we're doing here is + + + align:start position:0% +relevant to what we're doing here is +defining it as a power series. + + align:start position:0% +defining it as a power series. + + + align:start position:0% +defining it as a power series. +So I'm looking at + + align:start position:0% +So I'm looking at + + + align:start position:0% +So I'm looking at +but at e to the x + + align:start position:0% +but at e to the x + + + align:start position:0% +but at e to the x +and um and I'm looking at e to the x. So + + align:start position:0% +and um and I'm looking at e to the x. So + + + align:start position:0% +and um and I'm looking at e to the x. So +I define e capital e of x as this power + + align:start position:0% +I define e capital e of x as this power + + + align:start position:0% +I define e capital e of x as this power +series that we looked at before. + + align:start position:0% +series that we looked at before. + + + align:start position:0% +series that we looked at before. +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +Now I want to prove that this here is + + align:start position:0% +Now I want to prove that this here is + + + align:start position:0% +Now I want to prove that this here is +really what you should think of this. + + align:start position:0% +really what you should think of this. + + + align:start position:0% +really what you should think of this. +This here is the exponential function. + + align:start position:0% +This here is the exponential function. + + + align:start position:0% +This here is the exponential function. +So so I want to show but what does it + + align:start position:0% +So so I want to show but what does it + + + align:start position:0% +So so I want to show but what does it +mean that it is expon want to show + + align:start position:0% + + + + align:start position:0% + +that + + align:start position:0% +that + + + align:start position:0% +that +this is + + align:start position:0% +this is + + + align:start position:0% +this is +the exponential function. So what do I + + align:start position:0% +the exponential function. So what do I + + + align:start position:0% +the exponential function. So what do I +mean by I mean of course I could + + align:start position:0% +mean by I mean of course I could + + + align:start position:0% +mean by I mean of course I could +you know I could define any function to + + align:start position:0% +you know I could define any function to + + + align:start position:0% +you know I could define any function to +be the exponential function but there + + align:start position:0% +be the exponential function but there + + + align:start position:0% +be the exponential function but there +are certain properties of the + + align:start position:0% +are certain properties of the + + + align:start position:0% +are certain properties of the +exponential function that you would want + + align:start position:0% +exponential function that you would want + + + align:start position:0% +exponential function that you would want +right and so um well the first thing I + + align:start position:0% +right and so um well the first thing I + + + align:start position:0% +right and so um well the first thing I +observe is that e of zero + + align:start position:0% +observe is that e of zero + + + align:start position:0% +observe is that e of zero +is equal to if if all of these if x is + + align:start position:0% +is equal to if if all of these if x is + + + align:start position:0% +is equal to if if all of these if x is +zero then all of these are zero except + + align:start position:0% +zero then all of these are zero except + + + align:start position:0% +zero then all of these are zero except +when n is equal to zero and then x to + + align:start position:0% +when n is equal to zero and then x to + + + align:start position:0% +when n is equal to zero and then x to +the zero this here is by definition one + + align:start position:0% +the zero this here is by definition one + + + align:start position:0% +the zero this here is by definition one +okay and this here is is zero factorial + + align:start position:0% +okay and this here is is zero factorial + + + align:start position:0% +okay and this here is is zero factorial +is by definition one so this here is is + + align:start position:0% +is by definition one so this here is is + + + align:start position:0% +is by definition one so this here is is +one by definition + + align:start position:0% + + + + align:start position:0% + +and we know already by the way that this + + align:start position:0% +and we know already by the way that this + + + align:start position:0% +and we know already by the way that this +here we have already seen that the + + align:start position:0% +here we have already seen that the + + + align:start position:0% +here we have already seen that the +radius of convergence for this power + + align:start position:0% +radius of convergence for this power + + + align:start position:0% +radius of convergence for this power +series + + align:start position:0% + + + + align:start position:0% + +of convergence + + align:start position:0% + + + + align:start position:0% + +is equal to infinity right we have + + align:start position:0% +is equal to infinity right we have + + + align:start position:0% +is equal to infinity right we have +already seen that right so it's a well- + + align:start position:0% +already seen that right so it's a well- + + + align:start position:0% +already seen that right so it's a well- +definfined function for all x okay now + + align:start position:0% +definfined function for all x okay now + + + align:start position:0% +definfined function for all x okay now +I'm later going to prove so next time + + align:start position:0% + + + + align:start position:0% + +we will show + + align:start position:0% + + + + align:start position:0% + +that if you define it like that that + + align:start position:0% +that if you define it like that that + + + align:start position:0% +that if you define it like that that +that that this function here defined + + align:start position:0% +that that this function here defined + + + align:start position:0% +that that this function here defined +like that has a property that x e to x + + + align:start position:0% +like that has a property that x e to x + + + + align:start position:0% +like that has a property that x e to x + +y + + align:start position:0% +y + + + align:start position:0% +y +is equal to this product here. + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +Now uh using this well the first thing I + + align:start position:0% +Now uh using this well the first thing I + + + align:start position:0% +Now uh using this well the first thing I +can observe is I haven't really gotten + + align:start position:0% +can observe is I haven't really gotten + + + align:start position:0% +can observe is I haven't really gotten +to the property yet but I'm just at the + + align:start position:0% +to the property yet but I'm just at the + + + align:start position:0% +to the property yet but I'm just at the +moment I'm just examining that + + align:start position:0% +moment I'm just examining that + + + align:start position:0% +moment I'm just examining that +particular function you know some + + align:start position:0% +particular function you know some + + + align:start position:0% +particular function you know some +properties that it has + + align:start position:0% +properties that it has + + + align:start position:0% +properties that it has +and so the first thing I will observe is + + align:start position:0% +and so the first thing I will observe is + + + align:start position:0% +and so the first thing I will observe is +that if x here is positive or non- + + align:start position:0% +that if x here is positive or non- + + + align:start position:0% +that if x here is positive or non- +negative right then all of these numbers + + align:start position:0% +negative right then all of these numbers + + + align:start position:0% +negative right then all of these numbers +are non- negative so you're summing non- + + align:start position:0% +are non- negative so you're summing non- + + + align:start position:0% +are non- negative so you're summing non- +negative numbers so the sum is non- + + align:start position:0% +negative numbers so the sum is non- + + + align:start position:0% +negative numbers so the sum is non- +negative + + align:start position:0% +negative + + + align:start position:0% +negative +So if + + align:start position:0% +So if + + + align:start position:0% +So if +x is bigger equal to zero then it + + align:start position:0% +x is bigger equal to zero then it + + + align:start position:0% +x is bigger equal to zero then it +implies that e of x is big is actually + + align:start position:0% +implies that e of x is big is actually + + + align:start position:0% +implies that e of x is big is actually +strictly positive + + align:start position:0% +strictly positive + + + align:start position:0% +strictly positive +right in fact the smallest one is where + + align:start position:0% +right in fact the smallest one is where + + + align:start position:0% +right in fact the smallest one is where +you x was equal to zero but in that case + + align:start position:0% +you x was equal to zero but in that case + + + align:start position:0% +you x was equal to zero but in that case +you got one right + + align:start position:0% +you got one right + + + align:start position:0% +you got one right +now if x here is negative then it's not + + align:start position:0% +now if x here is negative then it's not + + + align:start position:0% +now if x here is negative then it's not +super clear right if x is negative you + + align:start position:0% +super clear right if x is negative you + + + align:start position:0% +super clear right if x is negative you +know some of these numbers that you'll + + align:start position:0% +know some of these numbers that you'll + + + align:start position:0% +know some of these numbers that you'll +be summing are positive and some of them + + align:start position:0% +be summing are positive and some of them + + + align:start position:0% +be summing are positive and some of them +are negative. So it's not at all clear + + align:start position:0% +are negative. So it's not at all clear + + + align:start position:0% +are negative. So it's not at all clear +what happened to the sum. But if if you + + align:start position:0% +what happened to the sum. But if if you + + + align:start position:0% +what happened to the sum. But if if you +grant me this for the for the moment + + align:start position:0% +grant me this for the for the moment + + + align:start position:0% +grant me this for the for the moment +this relationship here then we would + + align:start position:0% +this relationship here then we would + + + align:start position:0% +this relationship here then we would +have that e to the x minus e to minus + + align:start position:0% +have that e to the x minus e to minus + + + align:start position:0% +have that e to the x minus e to minus +sorry e in x - x. So that's the same as + + align:start position:0% +sorry e in x - x. So that's the same as + + + align:start position:0% +sorry e in x - x. So that's the same as +let me just make a little more space + + align:start position:0% +let me just make a little more space + + + align:start position:0% +let me just make a little more space +here. So e of zero which I already know + + align:start position:0% +here. So e of zero which I already know + + + align:start position:0% +here. So e of zero which I already know +is one. This here can think about that + + align:start position:0% +is one. This here can think about that + + + align:start position:0% +is one. This here can think about that +as x - x + + align:start position:0% +as x - x + + + align:start position:0% +as x - x +or if you will you could think about it + + align:start position:0% +or if you will you could think about it + + + align:start position:0% +or if you will you could think about it +as x + - x. + + align:start position:0% +as x + - x. + + + align:start position:0% +as x + - x. +And now if you grant me this this thing + + align:start position:0% +And now if you grant me this this thing + + + align:start position:0% +And now if you grant me this this thing +here that we prove next time then I can + + align:start position:0% +here that we prove next time then I can + + + align:start position:0% +here that we prove next time then I can +write this here as e + + align:start position:0% +write this here as e + + + align:start position:0% +write this here as e +of x * e of minus x right + + align:start position:0% +of x * e of minus x right + + + align:start position:0% +of x * e of minus x right +uh yeah sorry yeah + + align:start position:0% +uh yeah sorry yeah + + + align:start position:0% +uh yeah sorry yeah +okay and now if x here is negative then + + align:start position:0% +okay and now if x here is negative then + + + align:start position:0% +okay and now if x here is negative then +of course minus x is positive + + align:start position:0% + + + + align:start position:0% + +So this thing here. So now I know by + + align:start position:0% +So this thing here. So now I know by + + + align:start position:0% +So this thing here. So now I know by +this thing here that this here is + + align:start position:0% +this thing here that this here is + + + align:start position:0% +this thing here that this here is +positive. + + align:start position:0% +positive. + + + align:start position:0% +positive. +And so since the product of these two + + align:start position:0% +And so since the product of these two + + + align:start position:0% +And so since the product of these two +things is one, this here must be + + align:start position:0% +things is one, this here must be + + + align:start position:0% +things is one, this here must be +strictly positive as well. Right? So + + align:start position:0% +strictly positive as well. Right? So + + + align:start position:0% +strictly positive as well. Right? So +this imply that e to the x is also + + align:start position:0% +this imply that e to the x is also + + + align:start position:0% +this imply that e to the x is also +strictly positive. + + align:start position:0% +strictly positive. + + + align:start position:0% +strictly positive. +Okay? + + align:start position:0% +Okay? + + + align:start position:0% +Okay? +So this is just a couple of observation. + + align:start position:0% +So this is just a couple of observation. + + + align:start position:0% +So this is just a couple of observation. +Now, of course, I'm using that + + align:start position:0% +Now, of course, I'm using that + + + align:start position:0% +Now, of course, I'm using that +relationship that I haven't established + + align:start position:0% +relationship that I haven't established + + + align:start position:0% +relationship that I haven't established +yet, but I will establish that next + + align:start position:0% +yet, but I will establish that next + + + align:start position:0% +yet, but I will establish that next +time. + + align:start position:0% +time. + + + align:start position:0% +time. +The next thing is that I want to define + + align:start position:0% +The next thing is that I want to define + + + align:start position:0% +The next thing is that I want to define +the number E. + + align:start position:0% +the number E. + + + align:start position:0% +the number E. +And so I define this. + + align:start position:0% + + + + align:start position:0% + +So E that is 2.7 whatever I don't + + align:start position:0% +So E that is 2.7 whatever I don't + + + align:start position:0% +So E that is 2.7 whatever I don't +remember. Uh but so E we define so + + align:start position:0% +remember. Uh but so E we define so + + + align:start position:0% +remember. Uh but so E we define so +little E. So I define it as this + + align:start position:0% +little E. So I define it as this + + + align:start position:0% +little E. So I define it as this +function here + + align:start position:0% +function here + + + align:start position:0% +function here +evaluated in one. Okay. + + align:start position:0% + + + + align:start position:0% + +Now I want to define so I have my + + align:start position:0% +Now I want to define so I have my + + + align:start position:0% +Now I want to define so I have my +function capital E but I want to define + + align:start position:0% +function capital E but I want to define + + + align:start position:0% +function capital E but I want to define +a second function that is E. So, so want + + align:start position:0% +a second function that is E. So, so want + + + align:start position:0% +a second function that is E. So, so want +to define + + align:start position:0% + + + + align:start position:0% + +a second function + + align:start position:0% + + + + align:start position:0% + +and that is e to the x like this, right? + + align:start position:0% +and that is e to the x like this, right? + + + align:start position:0% +and that is e to the x like this, right? +And that should have the kind of + + align:start position:0% +And that should have the kind of + + + align:start position:0% +And that should have the kind of +properties that you uh that you think it + + align:start position:0% +properties that you uh that you think it + + + align:start position:0% +properties that you uh that you think it +should have. Okay? So but first before I + + align:start position:0% +should have. Okay? So but first before I + + + align:start position:0% +should have. Okay? So but first before I +do that let me just think if if you take + + align:start position:0% +do that let me just think if if you take + + + align:start position:0% +do that let me just think if if you take +e to the power m m here + + align:start position:0% +e to the power m m here + + + align:start position:0% +e to the power m m here +m is let's say that m here + + align:start position:0% +m is let's say that m here + + + align:start position:0% +m is let's say that m here +uh let's say that m is a is a integer + + align:start position:0% + + + + align:start position:0% + +if if um this here this here should just + + align:start position:0% +if if um this here this here should just + + + align:start position:0% +if if um this here this here should just +be + + align:start position:0% +be + + + align:start position:0% +be +e * E + + align:start position:0% + + + + align:start position:0% + +M*s + + align:start position:0% + + + + align:start position:0% + +right + + align:start position:0% +right + + + align:start position:0% +right +note that this here is this here I can + + align:start position:0% +note that this here is this here I can + + + align:start position:0% +note that this here is this here I can +of course write as E + + align:start position:0% +of course write as E + + + align:start position:0% +of course write as E +this is what E is so I can write it as + + align:start position:0% +this is what E is so I can write it as + + + align:start position:0% +this is what E is so I can write it as +this here + + align:start position:0% + + + + align:start position:0% + +M times + + align:start position:0% + + + + align:start position:0% + +but now I can use this hair that I will + + align:start position:0% +but now I can use this hair that I will + + + align:start position:0% +but now I can use this hair that I will +prove next time again. So if I take E of + + align:start position:0% +prove next time again. So if I take E of + + + align:start position:0% +prove next time again. So if I take E of +1 * E of 1 then that's E of two. And if + + align:start position:0% +1 * E of 1 then that's E of two. And if + + + align:start position:0% +1 * E of 1 then that's E of two. And if +I take E here three times then it's E of + + align:start position:0% +I take E here three times then it's E of + + + align:start position:0% +I take E here three times then it's E of +three. Right? So this thing here is + + align:start position:0% +three. Right? So this thing here is + + + align:start position:0% +three. Right? So this thing here is +actually the same as capital E of M. + + align:start position:0% +actually the same as capital E of M. + + + align:start position:0% +actually the same as capital E of M. +Right? + + align:start position:0% +Right? + + + align:start position:0% +Right? +So I have that. + + align:start position:0% +So I have that. + + + align:start position:0% +So I have that. +I also by definition so + + align:start position:0% +I also by definition so + + + align:start position:0% +I also by definition so +e to the zero this here I'm setting + + align:start position:0% +e to the zero this here I'm setting + + + align:start position:0% +e to the zero this here I'm setting +equal to one but I already have that one + + align:start position:0% +equal to one but I already have that one + + + align:start position:0% +equal to one but I already have that one +was equal to this capital e in in in + + align:start position:0% +was equal to this capital e in in in + + + align:start position:0% +was equal to this capital e in in in +zero right + + align:start position:0% +zero right + + + align:start position:0% +zero right +okay now what about if m here is a + + align:start position:0% +okay now what about if m here is a + + + align:start position:0% +okay now what about if m here is a +negative integer + + align:start position:0% + + + + align:start position:0% + +So suppose that m here is a negative + + align:start position:0% +So suppose that m here is a negative + + + align:start position:0% +So suppose that m here is a negative +integer. Suppose that m here is + + align:start position:0% +integer. Suppose that m here is + + + align:start position:0% +integer. Suppose that m here is +negative. + + align:start position:0% + + + + align:start position:0% + +So sorry what should e to the m here be? + + align:start position:0% +So sorry what should e to the m here be? + + + align:start position:0% +So sorry what should e to the m here be? +This here is just one over e to the + + align:start position:0% +This here is just one over e to the + + + align:start position:0% +This here is just one over e to the +minus + + align:start position:0% +minus + + + align:start position:0% +minus +uh m. Okay, minus m is a positive + + align:start position:0% +uh m. Okay, minus m is a positive + + + align:start position:0% +uh m. Okay, minus m is a positive +integer, right? So this so this makes + + align:start position:0% +integer, right? So this so this makes + + + align:start position:0% +integer, right? So this so this makes +sense. + + align:start position:0% + + + + align:start position:0% + +Now + + align:start position:0% +Now + + + align:start position:0% +Now +if you're looking at + + align:start position:0% +if you're looking at + + + align:start position:0% +if you're looking at +E + + align:start position:0% +E + + + align:start position:0% +E +to the again using this relationship + + align:start position:0% +to the again using this relationship + + + align:start position:0% +to the again using this relationship +here E the one and in fact the one we + + align:start position:0% +here E the one and in fact the one we + + + align:start position:0% +here E the one and in fact the one we +just did. + + align:start position:0% +just did. + + + align:start position:0% +just did. +So this is on integers + + align:start position:0% +So this is on integers + + + align:start position:0% +So this is on integers +um this here is now equal to E of zero + + align:start position:0% +um this here is now equal to E of zero + + + align:start position:0% +um this here is now equal to E of zero +which is equal to one. + + align:start position:0% +which is equal to one. + + + align:start position:0% +which is equal to one. +And so this imply and this is by this by + + align:start position:0% +And so this imply and this is by this by + + + align:start position:0% +And so this imply and this is by this by +that relationship over there. It's E of + + align:start position:0% +that relationship over there. It's E of + + + align:start position:0% +that relationship over there. It's E of +M * E of minus M. And so you see that + + align:start position:0% +M * E of minus M. And so you see that + + + align:start position:0% +M * E of minus M. And so you see that +this implies that E of minus M is equal + + align:start position:0% +this implies that E of minus M is equal + + + align:start position:0% +this implies that E of minus M is equal +to 1 / E of M by just dividing this on + + align:start position:0% +to 1 / E of M by just dividing this on + + + align:start position:0% +to 1 / E of M by just dividing this on +both sides. So you have this and this + + align:start position:0% +both sides. So you have this and this + + + align:start position:0% +both sides. So you have this and this +thing here. But this thing here, + + align:start position:0% +thing here. But this thing here, + + + align:start position:0% +thing here. But this thing here, +sorry, this is not what I wanted. Uh, if + + align:start position:0% +sorry, this is not what I wanted. Uh, if + + + align:start position:0% +sorry, this is not what I wanted. Uh, if +I take M negative, I just use the other + + align:start position:0% +I take M negative, I just use the other + + + align:start position:0% +I take M negative, I just use the other +one. Sorry, e of M + + align:start position:0% + + + + align:start position:0% + +is equal to 1 / E of minus M like that, + + align:start position:0% +is equal to 1 / E of minus M like that, + + + align:start position:0% +is equal to 1 / E of minus M like that, +right? + + align:start position:0% +right? + + + align:start position:0% +right? +M is M was supposed to be negative. So, + + align:start position:0% +M is M was supposed to be negative. So, + + + align:start position:0% +M is M was supposed to be negative. So, +this means that minus M is a positive + + align:start position:0% +this means that minus M is a positive + + + align:start position:0% +this means that minus M is a positive +integer. And this one here is then this + + align:start position:0% +integer. And this one here is then this + + + align:start position:0% +integer. And this one here is then this +one. I know that this here already agree + + align:start position:0% +one. I know that this here already agree + + + align:start position:0% +one. I know that this here already agree +with uh + + align:start position:0% +with uh + + + align:start position:0% +with uh +with um with uh this little function of + + align:start position:0% +with um with uh this little function of + + + align:start position:0% +with um with uh this little function of +e. So you see that this thing here is + + align:start position:0% +e. So you see that this thing here is + + + align:start position:0% +e. So you see that this thing here is +agrees with e to the power m. Right. + + align:start position:0% +agrees with e to the power m. Right. + + + align:start position:0% +agrees with e to the power m. Right. +Right. Because we we defined it like + + align:start position:0% +Right. Because we we defined it like + + + align:start position:0% +Right. Because we we defined it like +this. And now just checking that also on + + align:start position:0% +this. And now just checking that also on + + + align:start position:0% +this. And now just checking that also on +the negative integer this function here + + align:start position:0% +the negative integer this function here + + + align:start position:0% +the negative integer this function here +and this function here agree. Okay. So, + + align:start position:0% +and this function here agree. Okay. So, + + + align:start position:0% +and this function here agree. Okay. So, +so I now have these two different + + align:start position:0% +so I now have these two different + + + align:start position:0% +so I now have these two different +functions. Well, one I haven't really + + align:start position:0% +functions. Well, one I haven't really + + + align:start position:0% +functions. Well, one I haven't really +defined yet. I've only defined it now on + + align:start position:0% +defined yet. I've only defined it now on + + + align:start position:0% +defined yet. I've only defined it now on +all integers. + + align:start position:0% +all integers. + + + align:start position:0% +all integers. +But, but so far these two functions + + align:start position:0% +But, but so far these two functions + + + align:start position:0% +But, but so far these two functions +agree. + + align:start position:0% +agree. + + + align:start position:0% +agree. +Now what I also should have is that I + + align:start position:0% +Now what I also should have is that I + + + align:start position:0% +Now what I also should have is that I +should have so suppose you're looking at + + align:start position:0% +should have so suppose you're looking at + + + align:start position:0% +should have so suppose you're looking at +a rational number. + + align:start position:0% + + + + align:start position:0% + +So suppose you take a rational number. + + align:start position:0% +So suppose you take a rational number. + + + align:start position:0% +So suppose you take a rational number. +Remember we usually write a rational + + align:start position:0% +Remember we usually write a rational + + + align:start position:0% +Remember we usually write a rational +number. So suppose that Q here is a + + align:start position:0% +number. So suppose that Q here is a + + + align:start position:0% +number. So suppose that Q here is a +rational number. We usually write a + + align:start position:0% +rational number. We usually write a + + + align:start position:0% +rational number. We usually write a +rational number as + + align:start position:0% +rational number as + + + align:start position:0% +rational number as +a + + align:start position:0% + + + + align:start position:0% + +as an element in set. So it could be + + align:start position:0% +as an element in set. So it could be + + + align:start position:0% +as an element in set. So it could be +negative, it could be zero and n here is + + align:start position:0% +negative, it could be zero and n here is + + + align:start position:0% +negative, it could be zero and n here is +a positive integer. So fraction like + + align:start position:0% +a positive integer. So fraction like + + + align:start position:0% +a positive integer. So fraction like +this. + + align:start position:0% + + + + align:start position:0% + +Now what should E + + align:start position:0% +Now what should E + + + align:start position:0% +Now what should E +of Q be? Right? + + align:start position:0% +of Q be? Right? + + + align:start position:0% +of Q be? Right? +Well, E of Q um this here should be + + align:start position:0% +Well, E of Q um this here should be + + + align:start position:0% +Well, E of Q um this here should be +right how you would think about it is + + align:start position:0% +right how you would think about it is + + + align:start position:0% +right how you would think about it is +that it really should be something + + align:start position:0% +that it really should be something + + + align:start position:0% +that it really should be something +it should be something this here should + + align:start position:0% +it should be something this here should + + + align:start position:0% +it should be something this here should +be a number should be a number alpha and + + align:start position:0% +be a number should be a number alpha and + + + align:start position:0% +be a number should be a number alpha and +this should have the property that is + + align:start position:0% +this should have the property that is + + + align:start position:0% +this should have the property that is +positive + + align:start position:0% +positive + + + align:start position:0% +positive +and it should have the property so let's + + align:start position:0% +and it should have the property so let's + + + align:start position:0% +and it should have the property so let's +just write it so so E of Q this is m / + + align:start position:0% +just write it so so E of Q this is m / + + + align:start position:0% +just write it so so E of Q this is m / +n. It should have the property that if + + align:start position:0% +n. It should have the property that if + + + align:start position:0% +n. It should have the property that if +you raise it alpha here suppose you were + + align:start position:0% +you raise it alpha here suppose you were + + + align:start position:0% +you raise it alpha here suppose you were +raising it to the power n then you + + align:start position:0% +raising it to the power n then you + + + align:start position:0% +raising it to the power n then you +should get this number that we have + + align:start position:0% +should get this number that we have + + + align:start position:0% +should get this number that we have +already defined right. So should have it + + align:start position:0% +already defined right. So should have it + + + align:start position:0% +already defined right. So should have it +should be positive and when you raise it + + align:start position:0% +should be positive and when you raise it + + + align:start position:0% +should be positive and when you raise it +like this um then it should give you + + align:start position:0% +like this um then it should give you + + + align:start position:0% +like this um then it should give you +that and just like with square root of + + align:start position:0% +that and just like with square root of + + + align:start position:0% +that and just like with square root of +two it's just one element with this + + align:start position:0% +two it's just one element with this + + + align:start position:0% +two it's just one element with this +property + + align:start position:0% +property + + + align:start position:0% +property +okay so that's defined uh what it so so + + align:start position:0% +okay so that's defined uh what it so so + + + align:start position:0% +okay so that's defined uh what it so so +this way you see this way we have now + + align:start position:0% +this way you see this way we have now + + + align:start position:0% +this way you see this way we have now +defined + + align:start position:0% +defined + + + align:start position:0% +defined +this function e on all rational numbers + + align:start position:0% +this function e on all rational numbers + + + align:start position:0% +this function e on all rational numbers +but now we need to check right we need + + align:start position:0% +but now we need to check right we need + + + align:start position:0% +but now we need to check right we need +to check that this thing here need to + + align:start position:0% +to check that this thing here need to + + + align:start position:0% +to check that this thing here need to +check. So + + align:start position:0% + + + + align:start position:0% + +that that + + align:start position:0% +that that + + + align:start position:0% +that that +EQ + + align:start position:0% +EQ + + + align:start position:0% +EQ +is equal + + align:start position:0% +is equal + + + align:start position:0% +is equal +like that. Right? So I need to check + + align:start position:0% +like that. Right? So I need to check + + + align:start position:0% +like that. Right? So I need to check +that. Okay? + + align:start position:0% +that. Okay? + + + align:start position:0% +that. Okay? +So + + align:start position:0% +So + + + align:start position:0% +So +I want to say that that E to the Q is + + align:start position:0% +I want to say that that E to the Q is + + + align:start position:0% +I want to say that that E to the Q is +that alpha, right? + + align:start position:0% +that alpha, right? + + + align:start position:0% +that alpha, right? +So this means that + + align:start position:0% +So this means that + + + align:start position:0% +So this means that +I want to show + + align:start position:0% +I want to show + + + align:start position:0% +I want to show +so I need to show two things + + align:start position:0% +so I need to show two things + + + align:start position:0% +so I need to show two things +E + + align:start position:0% +E + + + align:start position:0% +E +to Q is positive. Well, I've already + + align:start position:0% +to Q is positive. Well, I've already + + + align:start position:0% +to Q is positive. Well, I've already +checked that right because you check at + + align:start position:0% +checked that right because you check at + + + align:start position:0% +checked that right because you check at +at E capital E at anything is positive. + + align:start position:0% +at E capital E at anything is positive. + + + align:start position:0% +at E capital E at anything is positive. +So this is okay. The second thing I need + + align:start position:0% +So this is okay. The second thing I need + + + align:start position:0% +So this is okay. The second thing I need +to check is that it has the property + + align:start position:0% +to check is that it has the property + + + align:start position:0% +to check is that it has the property +that if you raise it to the n power then + + align:start position:0% +that if you raise it to the n power then + + + align:start position:0% +that if you raise it to the n power then +you're getting uh then you're getting e + + align:start position:0% +you're getting uh then you're getting e + + + align:start position:0% +you're getting uh then you're getting e +um e to the to the m + + align:start position:0% +um e to the to the m + + + align:start position:0% +um e to the to the m +right now e to the m that's an integer. + + align:start position:0% +right now e to the m that's an integer. + + + align:start position:0% +right now e to the m that's an integer. +It could be negative + + align:start position:0% +It could be negative + + + align:start position:0% +It could be negative +but e to any negative integer whether + + align:start position:0% +but e to any negative integer whether + + + align:start position:0% +but e to any negative integer whether +it's ne positive or or negative we + + align:start position:0% +it's ne positive or or negative we + + + align:start position:0% +it's ne positive or or negative we +already checked that this is equal to + + align:start position:0% +already checked that this is equal to + + + align:start position:0% +already checked that this is equal to +capital e of m. + + align:start position:0% +capital e of m. + + + align:start position:0% +capital e of m. +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +So now I need to so this here is so now + + align:start position:0% +So now I need to so this here is so now + + + align:start position:0% +So now I need to so this here is so now +what is this? So what do I need to + + align:start position:0% +what is this? So what do I need to + + + align:start position:0% +what is this? So what do I need to +check? So I need to check + + align:start position:0% + + + + align:start position:0% + +that e + + align:start position:0% +that e + + + align:start position:0% +that e +to the m / n. This thing here raised to + + align:start position:0% +to the m / n. This thing here raised to + + + align:start position:0% +to the m / n. This thing here raised to +the power n is equal to this. But but + + align:start position:0% +the power n is equal to this. But but + + + align:start position:0% +the power n is equal to this. But but +what is this here? This here is just e + + align:start position:0% +what is this here? This here is just e + + + align:start position:0% +what is this here? This here is just e +to the m / n + + align:start position:0% +to the m / n + + + align:start position:0% +to the m / n +time multiply itself n times. + + align:start position:0% + + + + align:start position:0% + +So this is now n times. + + align:start position:0% + + + + align:start position:0% + +But now I can use again this thing that + + align:start position:0% +But now I can use again this thing that + + + align:start position:0% +But now I can use again this thing that +I proved next time that when I do it + + align:start position:0% +I proved next time that when I do it + + + align:start position:0% +I proved next time that when I do it +like here I'm just doing it two times + + align:start position:0% +like here I'm just doing it two times + + + align:start position:0% +like here I'm just doing it two times +and here I'm just doing it for I'm doing + + align:start position:0% +and here I'm just doing it for I'm doing + + + align:start position:0% +and here I'm just doing it for I'm doing +it for different x and y. But if I do it + + align:start position:0% +it for different x and y. But if I do it + + + align:start position:0% +it for different x and y. But if I do it +n times with the same x then I'm just + + align:start position:0% +n times with the same x then I'm just + + + align:start position:0% +n times with the same x then I'm just +adding that x together n times. + + align:start position:0% +adding that x together n times. + + + align:start position:0% +adding that x together n times. +Right? + + align:start position:0% +Right? + + + align:start position:0% +Right? +And so this thing here is the same as e + + align:start position:0% +And so this thing here is the same as e + + + align:start position:0% +And so this thing here is the same as e +by that rule over there n * m / n but + + align:start position:0% +by that rule over there n * m / n but + + + align:start position:0% +by that rule over there n * m / n but +this is just e of m as it should be + + align:start position:0% +this is just e of m as it should be + + + align:start position:0% +this is just e of m as it should be +right. So you see that these two + + align:start position:0% +right. So you see that these two + + + align:start position:0% +right. So you see that these two +functions here. So the conclusion so far + + align:start position:0% +functions here. So the conclusion so far + + + align:start position:0% +functions here. So the conclusion so far +is + + align:start position:0% + + + + align:start position:0% + +the conclusion now is that + + align:start position:0% +the conclusion now is that + + + align:start position:0% +the conclusion now is that +this function here + + align:start position:0% +this function here + + + align:start position:0% +this function here +is equal to this function here for all + + align:start position:0% +is equal to this function here for all + + + align:start position:0% +is equal to this function here for all +Q + + align:start position:0% + + + + align:start position:0% + +for all rational numbers. Okay. + + align:start position:0% +for all rational numbers. Okay. + + + align:start position:0% +for all rational numbers. Okay. +Now what other property should this + + align:start position:0% +Now what other property should this + + + align:start position:0% +Now what other property should this +exponential? So this here you know so + + align:start position:0% +exponential? So this here you know so + + + align:start position:0% +exponential? So this here you know so +far this is kind of the property that + + align:start position:0% +far this is kind of the property that + + + align:start position:0% +far this is kind of the property that +you want of the exponential function + + align:start position:0% +you want of the exponential function + + + align:start position:0% +you want of the exponential function +right but what other property should the + + align:start position:0% +right but what other property should the + + + align:start position:0% +right but what other property should the +exponential function have it should have + + align:start position:0% +exponential function have it should have + + + align:start position:0% +exponential function have it should have +one other property and that's enough to + + align:start position:0% +one other property and that's enough to + + + align:start position:0% +one other property and that's enough to +determine it and that is it should be + + align:start position:0% +determine it and that is it should be + + + align:start position:0% +determine it and that is it should be +continuous. So one more property is that + + align:start position:0% +continuous. So one more property is that + + + align:start position:0% +continuous. So one more property is that +this function e to the x when x is + + align:start position:0% +this function e to the x when x is + + + align:start position:0% +this function e to the x when x is +defined like this this function + + align:start position:0% + + + + align:start position:0% + +should be continuous + + align:start position:0% + + + + align:start position:0% + +and we'll talk a little bit more about + + align:start position:0% +and we'll talk a little bit more about + + + align:start position:0% +and we'll talk a little bit more about +continuous function in just a second. + + align:start position:0% +continuous function in just a second. + + + align:start position:0% +continuous function in just a second. +Okay. Now, now then I have a theorem + + align:start position:0% +Okay. Now, now then I have a theorem + + + align:start position:0% +Okay. Now, now then I have a theorem +that we prove next time + + align:start position:0% + + + + align:start position:0% + +one of the next times and and that is + + align:start position:0% +one of the next times and and that is + + + align:start position:0% +one of the next times and and that is +that suppose you take two functions. + + align:start position:0% +that suppose you take two functions. + + + align:start position:0% +that suppose you take two functions. +So so we then can appeal to the + + align:start position:0% +So so we then can appeal to the + + + align:start position:0% +So so we then can appeal to the +following theorem. + + align:start position:0% +following theorem. + + + align:start position:0% +following theorem. +If f and g are two + + align:start position:0% +If f and g are two + + + align:start position:0% +If f and g are two +continuous functions + + align:start position:0% + + + + align:start position:0% + +on a + + align:start position:0% +on a + + + align:start position:0% +on a +that agree + + align:start position:0% + + + + align:start position:0% + +on all + + align:start position:0% +on all + + + align:start position:0% +on all +of do. + + align:start position:0% +of do. + + + align:start position:0% +of do. +So if you have two continuous functions + + align:start position:0% +So if you have two continuous functions + + + align:start position:0% +So if you have two continuous functions +and they if you restrict it to the + + align:start position:0% +and they if you restrict it to the + + + align:start position:0% +and they if you restrict it to the +rational number then the two functions + + align:start position:0% +rational number then the two functions + + + align:start position:0% +rational number then the two functions +are the same. + + align:start position:0% +are the same. + + + align:start position:0% +are the same. +If they're both continuous then the + + align:start position:0% +If they're both continuous then the + + + align:start position:0% +If they're both continuous then the +function has to be the same. So this + + align:start position:0% +function has to be the same. So this + + + align:start position:0% +function has to be the same. So this +implies that f is equal to g everywhere + + align:start position:0% +implies that f is equal to g everywhere + + + align:start position:0% +implies that f is equal to g everywhere +not just on the rational function + + align:start position:0% +not just on the rational function + + + align:start position:0% +not just on the rational function +rational numbers. + + align:start position:0% + + + + align:start position:0% + +Okay. So we'll prove that either next + + align:start position:0% +Okay. So we'll prove that either next + + + align:start position:0% +Okay. So we'll prove that either next +time or the following time. Let me just + + align:start position:0% +time or the following time. Let me just + + + align:start position:0% +time or the following time. Let me just +go back and remind you + + align:start position:0% +go back and remind you + + + align:start position:0% +go back and remind you +about what it means for a function to be + + align:start position:0% +about what it means for a function to be + + + align:start position:0% +about what it means for a function to be +continuous. + + align:start position:0% +continuous. + + + align:start position:0% +continuous. +Uh so + + align:start position:0% +Uh so + + + align:start position:0% +Uh so +so this is the fine + + align:start position:0% + + + + align:start position:0% + +so continuous. + + align:start position:0% + + + + align:start position:0% + +So suppose you take a function and the + + align:start position:0% +So suppose you take a function and the + + + align:start position:0% +So suppose you take a function and the +function uh is it doesn't even need to + + align:start position:0% +function uh is it doesn't even need to + + + align:start position:0% +function uh is it doesn't even need to +be defined on an interval. Um + + align:start position:0% +be defined on an interval. Um + + + align:start position:0% +be defined on an interval. Um +I but you may as well assume that it's + + align:start position:0% +I but you may as well assume that it's + + + align:start position:0% +I but you may as well assume that it's +interval but it doesn't need to be + + align:start position:0% +interval but it doesn't need to be + + + align:start position:0% +interval but it doesn't need to be +defined on the interval. + + align:start position:0% +defined on the interval. + + + align:start position:0% +defined on the interval. +So a function here f is set to be + + align:start position:0% +So a function here f is set to be + + + align:start position:0% +So a function here f is set to be +continuous + + align:start position:0% + + + + align:start position:0% + +be continuous + + align:start position:0% + + + + align:start position:0% + +at x here + + align:start position:0% +at x here + + + align:start position:0% +at x here +in the domain where it's defined. + + align:start position:0% +in the domain where it's defined. + + + align:start position:0% +in the domain where it's defined. +If + + align:start position:0% + + + + align:start position:0% + +for all + + align:start position:0% +for all + + + align:start position:0% +for all +epsilon greater than zero + + align:start position:0% +epsilon greater than zero + + + align:start position:0% +epsilon greater than zero +there exist + + align:start position:0% + + + + align:start position:0% + +delta greater than zero such that + + align:start position:0% +delta greater than zero such that + + + align:start position:0% +delta greater than zero such that +if x - x0 + + align:start position:0% +if x - x0 + + + align:start position:0% +if x - x0 +is smaller than delta then the images + + align:start position:0% +is smaller than delta then the images + + + align:start position:0% +is smaller than delta then the images +are epsilon close to each + + align:start position:0% + + + + align:start position:0% + +And so again this delta typically + + align:start position:0% +And so again this delta typically + + + align:start position:0% +And so again this delta typically +depends not just on epsilon but also on + + align:start position:0% +depends not just on epsilon but also on + + + align:start position:0% +depends not just on epsilon but also on +x0 right and so the function so this is + + align:start position:0% +x0 right and so the function so this is + + + align:start position:0% +x0 right and so the function so this is +so it's continuous at a point x0 if this + + align:start position:0% +so it's continuous at a point x0 if this + + + align:start position:0% +so it's continuous at a point x0 if this +here is the case and the function f here + + align:start position:0% +here is the case and the function f here + + + align:start position:0% +here is the case and the function f here +is set to be continuous + + align:start position:0% + + + + align:start position:0% + +If + + align:start position:0% +If + + + align:start position:0% +If +it is + + align:start position:0% +it is + + + align:start position:0% +it is +continuous + + align:start position:0% + + + + align:start position:0% + +at all points. + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +Now let's just let's let's look at two + + align:start position:0% +Now let's just let's let's look at two + + + align:start position:0% +Now let's just let's let's look at two +simple examples and and and and + + align:start position:0% +simple examples and and and and + + + align:start position:0% +simple examples and and and and +then once we have those + + align:start position:0% +then once we have those + + + align:start position:0% +then once we have those +uh then together with some algebraic + + align:start position:0% +uh then together with some algebraic + + + align:start position:0% +uh then together with some algebraic +rules that are similar to the algebraic + + align:start position:0% +rules that are similar to the algebraic + + + align:start position:0% +rules that are similar to the algebraic +rules that we had for sequences + + align:start position:0% +rules that we had for sequences + + + align:start position:0% +rules that we had for sequences +then we get a huge + + align:start position:0% +then we get a huge + + + align:start position:0% +then we get a huge +number of examples of you get a large uh + + align:start position:0% +number of examples of you get a large uh + + + align:start position:0% +number of examples of you get a large uh +collection of examples of continuous + + align:start position:0% +collection of examples of continuous + + + align:start position:0% +collection of examples of continuous +functions. + + align:start position:0% +functions. + + + align:start position:0% +functions. +So the first example is like the + + align:start position:0% +So the first example is like the + + + align:start position:0% +So the first example is like the +simplest of all example + + align:start position:0% +simplest of all example + + + align:start position:0% +simplest of all example +where f here is is the constant + + align:start position:0% +where f here is is the constant + + + align:start position:0% +where f here is is the constant +function. + + align:start position:0% + + + + align:start position:0% + +So I'm thinking about f here is to be + + align:start position:0% +So I'm thinking about f here is to be + + + align:start position:0% +So I'm thinking about f here is to be +defined from r into r and for each x in + + align:start position:0% +defined from r into r and for each x in + + + align:start position:0% +defined from r into r and for each x in +r it's equal to the same constant. Okay. + + align:start position:0% +r it's equal to the same constant. Okay. + + + align:start position:0% +r it's equal to the same constant. Okay. +So that's f. I want to show that this f + + align:start position:0% +So that's f. I want to show that this f + + + align:start position:0% +So that's f. I want to show that this f +is that a constant function is + + align:start position:0% +is that a constant function is + + + align:start position:0% +is that a constant function is +continuous. So given so proof + + align:start position:0% +continuous. So given so proof + + + align:start position:0% +continuous. So given so proof +of continuity. + + align:start position:0% + + + + align:start position:0% + +So given epsilon + + align:start position:0% +So given epsilon + + + align:start position:0% +So given epsilon +given epsilon greater than zero in this + + align:start position:0% +given epsilon greater than zero in this + + + align:start position:0% +given epsilon greater than zero in this +part says you can pick any delta you + + align:start position:0% +part says you can pick any delta you + + + align:start position:0% +part says you can pick any delta you +want. I'm just picking + + align:start position:0% +want. I'm just picking + + + align:start position:0% +want. I'm just picking +let + + align:start position:0% +let + + + align:start position:0% +let +delta be equal to one but you could pick + + align:start position:0% +delta be equal to one but you could pick + + + align:start position:0% +delta be equal to one but you could pick +anything you want. It has to be positive + + align:start position:0% +anything you want. It has to be positive + + + align:start position:0% +anything you want. It has to be positive +but you can pick anything you want. Then + + align:start position:0% +but you can pick anything you want. Then + + + align:start position:0% +but you can pick anything you want. Then +you have that if x minus x0 + + align:start position:0% +you have that if x minus x0 + + + align:start position:0% +you have that if x minus x0 +is less than one. + + align:start position:0% +is less than one. + + + align:start position:0% +is less than one. +Well then of course f ofx + + align:start position:0% +Well then of course f ofx + + + align:start position:0% +Well then of course f ofx +minus f of x0 both of these numbers is + + align:start position:0% +minus f of x0 both of these numbers is + + + align:start position:0% +minus f of x0 both of these numbers is +c. So the difference so this is c minus + + align:start position:0% +c. So the difference so this is c minus + + + align:start position:0% +c. So the difference so this is c minus +c. + + align:start position:0% +c. + + + align:start position:0% +c. +So this is zero. So this is surely less + + align:start position:0% +So this is zero. So this is surely less + + + align:start position:0% +So this is zero. So this is surely less +than epsilon. Right? So they show that + + align:start position:0% +than epsilon. Right? So they show that + + + align:start position:0% +than epsilon. Right? So they show that +it's the function is continuous at all + + align:start position:0% +it's the function is continuous at all + + + align:start position:0% +it's the function is continuous at all +point. And you see that you could pick + + align:start position:0% +point. And you see that you could pick + + + align:start position:0% +point. And you see that you could pick +delta anything you want. And of course + + align:start position:0% +delta anything you want. And of course + + + align:start position:0% +delta anything you want. And of course +in particular it's it's doesn't even + + align:start position:0% +in particular it's it's doesn't even + + + align:start position:0% +in particular it's it's doesn't even +depend on x0. It doesn't depend on + + align:start position:0% +depend on x0. It doesn't depend on + + + align:start position:0% +depend on x0. It doesn't depend on +epsilon and it doesn't depend on x0. + + align:start position:0% +epsilon and it doesn't depend on x0. + + + align:start position:0% +epsilon and it doesn't depend on x0. +Okay. So the constant functions are for + + align:start position:0% +Okay. So the constant functions are for + + + align:start position:0% +Okay. So the constant functions are for +continuous. + + align:start position:0% +continuous. + + + align:start position:0% +continuous. +What about then next simple the next + + align:start position:0% +What about then next simple the next + + + align:start position:0% +What about then next simple the next +simplest function would be the linear + + align:start position:0% +simplest function would be the linear + + + align:start position:0% +simplest function would be the linear +function or just x function x. + + align:start position:0% +function or just x function x. + + + align:start position:0% +function or just x function x. +So suppose you take + + align:start position:0% +So suppose you take + + + align:start position:0% +So suppose you take +because you're looking at + + align:start position:0% + + + + align:start position:0% + +at the function f on r to r + + align:start position:0% +at the function f on r to r + + + align:start position:0% +at the function f on r to r +where f of x is equal to x. So this is + + align:start position:0% +where f of x is equal to x. So this is + + + align:start position:0% +where f of x is equal to x. So this is +also continuous + + align:start position:0% + + + + align:start position:0% + +also continuous + + align:start position:0% + + + + align:start position:0% + +and the proof of that + + align:start position:0% + + + + align:start position:0% + +given epsilon + + align:start position:0% + + + + align:start position:0% + +set + + align:start position:0% +set + + + align:start position:0% +set +delta equal to epsilon + + align:start position:0% +delta equal to epsilon + + + align:start position:0% +delta equal to epsilon +then you see that if x - x0 + + align:start position:0% +then you see that if x - x0 + + + align:start position:0% +then you see that if x - x0 +is less than epsilon then + + align:start position:0% +is less than epsilon then + + + align:start position:0% +is less than epsilon then +uh f ofx minus f of x0 but f of x is + + align:start position:0% +uh f ofx minus f of x0 but f of x is + + + align:start position:0% +uh f ofx minus f of x0 but f of x is +equal to x and f of x0 is equal to x0 so + + align:start position:0% +equal to x and f of x0 is equal to x0 so + + + align:start position:0% +equal to x and f of x0 is equal to x0 so +this thing here is of course less than + + align:start position:0% +this thing here is of course less than + + + align:start position:0% +this thing here is of course less than +epsilon not right + + align:start position:0% +epsilon not right + + + align:start position:0% +epsilon not right +so this is so so so that's kind of + + align:start position:0% +so this is so so so that's kind of + + + align:start position:0% +so this is so so so that's kind of +trivial okay + + align:start position:0% +trivial okay + + + align:start position:0% +trivial okay +now the next thing is that we have uh + + align:start position:0% +now the next thing is that we have uh + + + align:start position:0% +now the next thing is that we have uh +the algebraic uh property of continuous + + align:start position:0% +the algebraic uh property of continuous + + + align:start position:0% +the algebraic uh property of continuous +functions. So we have some as a break + + align:start position:0% +functions. So we have some as a break + + + align:start position:0% +functions. So we have some as a break +property. + + align:start position:0% + + + + align:start position:0% + +properties + + align:start position:0% + + + + align:start position:0% + +of continuous function + + align:start position:0% + + + + align:start position:0% + +and I will prove a couple of these and + + align:start position:0% +and I will prove a couple of these and + + + align:start position:0% +and I will prove a couple of these and +but the proofs you see in just a second + + align:start position:0% +but the proofs you see in just a second + + + align:start position:0% +but the proofs you see in just a second +that the proof is like I mean the + + align:start position:0% +that the proof is like I mean the + + + align:start position:0% +that the proof is like I mean the +properties is is is and There's good + + align:start position:0% +properties is is is and There's good + + + align:start position:0% +properties is is is and There's good +reasons for that. They're very similar + + align:start position:0% +reasons for that. They're very similar + + + align:start position:0% +reasons for that. They're very similar +to the property we had for for limits of + + align:start position:0% +to the property we had for for limits of + + + align:start position:0% +to the property we had for for limits of +sequences and the proofs are are very + + align:start position:0% +sequences and the proofs are are very + + + align:start position:0% +sequences and the proofs are are very +similar to those proofs. So the first + + align:start position:0% +similar to those proofs. So the first + + + align:start position:0% +similar to those proofs. So the first +one is that if + + align:start position:0% +one is that if + + + align:start position:0% +one is that if +f and g are continuous + + align:start position:0% + + + + align:start position:0% + +then the sum of these two functions is + + align:start position:0% +then the sum of these two functions is + + + align:start position:0% +then the sum of these two functions is +also continuous. + + align:start position:0% + + + + align:start position:0% + +The next one is that if um + + align:start position:0% +The next one is that if um + + + align:start position:0% +The next one is that if um +f is continuous + + align:start position:0% + + + + align:start position:0% + +and and c is a constant + + align:start position:0% + + + + align:start position:0% + +then c * f is continuous. + + align:start position:0% + + + + align:start position:0% + +The third property is + + align:start position:0% +The third property is + + + align:start position:0% +The third property is +that again if + + align:start position:0% +that again if + + + align:start position:0% +that again if +uh f comma g are continuous + + align:start position:0% + + + + align:start position:0% + +then the product + + align:start position:0% +then the product + + + align:start position:0% +then the product +then the product f * d is continuous. + + align:start position:0% + + + + align:start position:0% + +The fourth property is that if + + align:start position:0% +The fourth property is that if + + + align:start position:0% +The fourth property is that if +f is continuous + + align:start position:0% + + + + align:start position:0% + +and and uh and f is never equal to zero + + align:start position:0% +and and uh and f is never equal to zero + + + align:start position:0% +and and uh and f is never equal to zero +then + + align:start position:0% +then + + + align:start position:0% +then +1 / f is continuous. + + align:start position:0% + + + + align:start position:0% + +And the fifth property that's a little + + align:start position:0% +And the fifth property that's a little + + + align:start position:0% +And the fifth property that's a little +bit different and we didn't have that + + align:start position:0% +bit different and we didn't have that + + + align:start position:0% +bit different and we didn't have that +for sequences. + + align:start position:0% +for sequences. + + + align:start position:0% +for sequences. +The fifth property is that if you take a + + align:start position:0% +The fifth property is that if you take a + + + align:start position:0% +The fifth property is that if you take a +map f of take a function f. + + align:start position:0% +map f of take a function f. + + + align:start position:0% +map f of take a function f. +Let's think about it as a function from + + align:start position:0% +Let's think about it as a function from + + + align:start position:0% +Let's think about it as a function from +R to R. And then you have another + + align:start position:0% +R to R. And then you have another + + + align:start position:0% +R to R. And then you have another +function G from R to R. + + align:start position:0% +function G from R to R. + + + align:start position:0% +function G from R to R. +And now you could look at where you take + + align:start position:0% +And now you could look at where you take + + + align:start position:0% +And now you could look at where you take +first. You could look at the + + align:start position:0% +first. You could look at the + + + align:start position:0% +first. You could look at the +composition. So you could look at the + + align:start position:0% +composition. So you could look at the + + + align:start position:0% +composition. So you could look at the +function H of X which is where you first + + align:start position:0% +function H of X which is where you first + + + align:start position:0% +function H of X which is where you first +apply F of X F to X and then you apply G + + align:start position:0% +apply F of X F to X and then you apply G + + + align:start position:0% +apply F of X F to X and then you apply G +to it. Right? So if both f so if this + + align:start position:0% +to it. Right? So if both f so if this + + + align:start position:0% +to it. Right? So if both f so if this +here + + align:start position:0% +here + + + align:start position:0% +here +and the function g are continuous + + align:start position:0% + + + + align:start position:0% + +then the composition here is also + + align:start position:0% +then the composition here is also + + + align:start position:0% +then the composition here is also +continuous. + + align:start position:0% + + + + align:start position:0% + +When you have a composition of function + + align:start position:0% +When you have a composition of function + + + align:start position:0% +When you have a composition of function +you always have to be careful that it + + align:start position:0% +you always have to be careful that it + + + align:start position:0% +you always have to be careful that it +makes sense. So to make sense means that + + align:start position:0% +makes sense. So to make sense means that + + + align:start position:0% +makes sense. So to make sense means that +the function g the one that the second + + align:start position:0% +the function g the one that the second + + + align:start position:0% +the function g the one that the second +function that you apply is that the + + align:start position:0% +function that you apply is that the + + + align:start position:0% +function that you apply is that the +image of when you use the first function + + align:start position:0% +image of when you use the first function + + + align:start position:0% +image of when you use the first function +you have to make sure that what you get + + align:start position:0% +you have to make sure that what you get + + + align:start position:0% +you have to make sure that what you get +here is uh at some point where G is + + align:start position:0% +here is uh at some point where G is + + + align:start position:0% +here is uh at some point where G is +defined. Right? So I just for simplicity + + align:start position:0% +defined. Right? So I just for simplicity + + + align:start position:0% +defined. Right? So I just for simplicity +I just uh looked at maps into um + + align:start position:0% +I just uh looked at maps into um + + + align:start position:0% +I just uh looked at maps into um +functions into R where G also was + + align:start position:0% +functions into R where G also was + + + align:start position:0% +functions into R where G also was +defined on all of our but of course it + + align:start position:0% +defined on all of our but of course it + + + align:start position:0% +defined on all of our but of course it +doesn't have to be defined but you just + + align:start position:0% +doesn't have to be defined but you just + + + align:start position:0% +doesn't have to be defined but you just +have to make sure + + align:start position:0% +have to make sure + + + align:start position:0% +have to make sure +that G is defined where F and X end up + + align:start position:0% +that G is defined where F and X end up + + + align:start position:0% +that G is defined where F and X end up +right + + align:start position:0% +right + + + align:start position:0% +right +okay I'll talk a little bit about you + + align:start position:0% +okay I'll talk a little bit about you + + + align:start position:0% +okay I'll talk a little bit about you +know these uh how to prove these but + + align:start position:0% +know these uh how to prove these but + + + align:start position:0% +know these uh how to prove these but +it's very similar to what we did for + + align:start position:0% +it's very similar to what we did for + + + align:start position:0% +it's very similar to what we did for +sequences let me just apply apply it. + + align:start position:0% +sequences let me just apply apply it. + + + align:start position:0% +sequences let me just apply apply it. +So let me look at an example where I + + align:start position:0% +So let me look at an example where I + + + align:start position:0% +So let me look at an example where I +apply it. + + align:start position:0% + + + + align:start position:0% + +So suppose you take x2 + one. Suppose + + align:start position:0% +So suppose you take x2 + one. Suppose + + + align:start position:0% +So suppose you take x2 + one. Suppose +you take this function here. I'll take + + align:start position:0% +you take this function here. I'll take + + + align:start position:0% +you take this function here. I'll take +look at two examples. + + align:start position:0% + + + + align:start position:0% + +Suppose you take this function here. + + align:start position:0% +Suppose you take this function here. + + + align:start position:0% +Suppose you take this function here. +I claim that this here is continuous. + + align:start position:0% +I claim that this here is continuous. + + + align:start position:0% +I claim that this here is continuous. +I'm not going to go through the proof + + align:start position:0% +I'm not going to go through the proof + + + align:start position:0% +I'm not going to go through the proof +because + + align:start position:0% +because + + + align:start position:0% +because +because we already actually so if this + + align:start position:0% +because we already actually so if this + + + align:start position:0% +because we already actually so if this +here prove at least some of these + + align:start position:0% +here prove at least some of these + + + align:start position:0% +here prove at least some of these +properties but once you have that then + + align:start position:0% +properties but once you have that then + + + align:start position:0% +properties but once you have that then +you see that well you have that g of x + + align:start position:0% +you see that well you have that g of x + + + align:start position:0% +you see that well you have that g of x +equal to x this here is continuous. + + align:start position:0% +equal to x this here is continuous. + + + align:start position:0% +equal to x this here is continuous. +This is what we proved + + align:start position:0% +This is what we proved + + + align:start position:0% +This is what we proved +just a little while ago. And if you take + + align:start position:0% +just a little while ago. And if you take + + + align:start position:0% +just a little while ago. And if you take +the function that is constant and in + + align:start position:0% +the function that is constant and in + + + align:start position:0% +the function that is constant and in +this case constant one, we already + + align:start position:0% +this case constant one, we already + + + align:start position:0% +this case constant one, we already +proved that that's continuous. Right? + + align:start position:0% +proved that that's continuous. Right? + + + align:start position:0% +proved that that's continuous. Right? +Now this means that if you take a + + align:start position:0% +Now this means that if you take a + + + align:start position:0% +Now this means that if you take a +continuous function + + align:start position:0% +continuous function + + + align:start position:0% +continuous function +by by by whatever root three or + + align:start position:0% +by by by whatever root three or + + + align:start position:0% +by by by whatever root three or +something like that over there uh and + + align:start position:0% +something like that over there uh and + + + align:start position:0% +something like that over there uh and +you take the function where it's like + + align:start position:0% +you take the function where it's like + + + align:start position:0% +you take the function where it's like +multiply by itself this function here + + align:start position:0% +multiply by itself this function here + + + align:start position:0% +multiply by itself this function here +right because g is continuous this + + align:start position:0% +right because g is continuous this + + + align:start position:0% +right because g is continuous this +function here is also continuous + + align:start position:0% + + + + align:start position:0% + +and then once you have that you can add + + align:start position:0% +and then once you have that you can add + + + align:start position:0% +and then once you have that you can add +another. So you can look at G ^2 + + align:start position:0% +another. So you can look at G ^2 + + + align:start position:0% +another. So you can look at G ^2 +plus H. + + align:start position:0% +plus H. + + + align:start position:0% +plus H. +This is you now have established this is + + align:start position:0% +This is you now have established this is + + + align:start position:0% +This is you now have established this is +continuous. This here is a constant + + align:start position:0% +continuous. This here is a constant + + + align:start position:0% +continuous. This here is a constant +function. So we already proven that this + + align:start position:0% +function. So we already proven that this + + + align:start position:0% +function. So we already proven that this +is continuous. So the sum by rule one + + align:start position:0% +is continuous. So the sum by rule one + + + align:start position:0% +is continuous. So the sum by rule one +over there this here is continuous. + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +So this means that so okay. So this show + + align:start position:0% +So this means that so okay. So this show + + + align:start position:0% +So this means that so okay. So this show +that this function here this quadratic + + align:start position:0% +that this function here this quadratic + + + align:start position:0% +that this function here this quadratic +function is continuous. But in fact of + + align:start position:0% +function is continuous. But in fact of + + + align:start position:0% +function is continuous. But in fact of +course this argument gives you that any + + align:start position:0% +course this argument gives you that any + + + align:start position:0% +course this argument gives you that any +polomium any polomial is continuous + + align:start position:0% +polomium any polomial is continuous + + + align:start position:0% +polomium any polomial is continuous +right so this here proves that any + + align:start position:0% +right so this here proves that any + + + align:start position:0% +right so this here proves that any +polomium + + align:start position:0% +polomium + + + align:start position:0% +polomium +right so this the you know like the + + align:start position:0% +right so this the you know like the + + + align:start position:0% +right so this the you know like the +similar argument right so if you're + + align:start position:0% +similar argument right so if you're + + + align:start position:0% +similar argument right so if you're +using so if you're using one two and + + align:start position:0% +using so if you're using one two and + + + align:start position:0% +using so if you're using one two and +three + + align:start position:0% +three + + + align:start position:0% +three +then just starting at the constant + + align:start position:0% +then just starting at the constant + + + align:start position:0% +then just starting at the constant +function and the function x you can get + + align:start position:0% +function and the function x you can get + + + align:start position:0% +function and the function x you can get +to any polomium and and and using these + + align:start position:0% +to any polomium and and and using these + + + align:start position:0% +to any polomium and and and using these +operations and so it means that any + + align:start position:0% +operations and so it means that any + + + align:start position:0% +operations and so it means that any +polomial is continuous right so so you + + align:start position:0% +polomial is continuous right so so you + + + align:start position:0% +polomial is continuous right so so you +have the following theorem + + align:start position:0% + + + + align:start position:0% + +all polomials + + align:start position:0% + + + + align:start position:0% + +are continuous + + align:start position:0% + + + + align:start position:0% + +Okay. And in fact, so this is just using + + align:start position:0% +Okay. And in fact, so this is just using + + + align:start position:0% +Okay. And in fact, so this is just using +one, two, and three over here. If you + + align:start position:0% +one, two, and three over here. If you + + + align:start position:0% +one, two, and three over here. If you +now also bring in four + + align:start position:0% +now also bring in four + + + align:start position:0% +now also bring in four +then you have then so so this is this is + + align:start position:0% +then you have then so so this is this is + + + align:start position:0% +then you have then so so this is this is +proof, + + align:start position:0% + + + + align:start position:0% + +right? So it follows it uses the two + + align:start position:0% +right? So it follows it uses the two + + + align:start position:0% +right? So it follows it uses the two +examples that we gave and then + + align:start position:0% +examples that we gave and then + + + align:start position:0% +examples that we gave and then +in addition to that it follows from + + align:start position:0% +in addition to that it follows from + + + align:start position:0% +in addition to that it follows from +the algebraic rules + + align:start position:0% + + + + align:start position:0% + +one through uh one through three. + + align:start position:0% +one through uh one through three. + + + align:start position:0% +one through uh one through three. +If you bring in alt four, five is + + align:start position:0% +If you bring in alt four, five is + + + align:start position:0% +If you bring in alt four, five is +something slightly different. But if you + + align:start position:0% +something slightly different. But if you + + + align:start position:0% +something slightly different. But if you +bring in four here, then you you get + + align:start position:0% +bring in four here, then you you get + + + align:start position:0% +bring in four here, then you you get +that what's called any rational function + + align:start position:0% + + + + align:start position:0% + +uh any + + align:start position:0% +uh any + + + align:start position:0% +uh any +all rational function + + align:start position:0% + + + + align:start position:0% + +are continuous. So what is a a rational + + align:start position:0% +are continuous. So what is a a rational + + + align:start position:0% +are continuous. So what is a a rational +function? + + align:start position:0% + + + + align:start position:0% + +A rational function is just where you're + + align:start position:0% +A rational function is just where you're + + + align:start position:0% +A rational function is just where you're +taking a polomial + + align:start position:0% + + + + align:start position:0% + +and then you're dividing by another + + align:start position:0% +and then you're dividing by another + + + align:start position:0% +and then you're dividing by another +polinomial. + + align:start position:0% +polinomial. + + + align:start position:0% +polinomial. +Right? So we know that any polomial is + + align:start position:0% +Right? So we know that any polomial is + + + align:start position:0% +Right? So we know that any polomial is +continuous. If you take another polomium + + align:start position:0% +continuous. If you take another polomium + + + align:start position:0% +continuous. If you take another polomium +and let's look at the that other + + align:start position:0% +and let's look at the that other + + + align:start position:0% +and let's look at the that other +polinomial away from the roots away from + + align:start position:0% +polinomial away from the roots away from + + + align:start position:0% +polinomial away from the roots away from +where it is zero away from it where it's + + align:start position:0% +where it is zero away from it where it's + + + align:start position:0% +where it is zero away from it where it's +zero this is I mean it's of course even + + align:start position:0% +zero this is I mean it's of course even + + + align:start position:0% +zero this is I mean it's of course even +continuous where it's zero but you can't + + align:start position:0% +continuous where it's zero but you can't + + + align:start position:0% +continuous where it's zero but you can't +divide by it right so away from it this + + align:start position:0% +divide by it right so away from it this + + + align:start position:0% +divide by it right so away from it this +function here is not zero and it's + + align:start position:0% +function here is not zero and it's + + + align:start position:0% +function here is not zero and it's +continuous this is continuous rule four + + align:start position:0% +continuous this is continuous rule four + + + align:start position:0% +continuous this is continuous rule four +so this is proved + + align:start position:0% + + + + align:start position:0% + +Uh the theorem above + + align:start position:0% + + + + align:start position:0% + +plus + + align:start position:0% +plus + + + align:start position:0% +plus +rule four, + + align:start position:0% + + + + align:start position:0% + +right? Yeah. + + align:start position:0% + + + + align:start position:0% + +>> Yeah. + + align:start position:0% +>> Yeah. + + + align:start position:0% +>> Yeah. +>> Yeah. + + align:start position:0% + + + + align:start position:0% + +>> Yeah. In that case, exactly. In that + + align:start position:0% +>> Yeah. In that case, exactly. In that + + + align:start position:0% +>> Yeah. In that case, exactly. In that +case, I chose delta to be simply + + align:start position:0% +case, I chose delta to be simply + + + align:start position:0% +case, I chose delta to be simply +epsilon. Yeah. Yeah. + + align:start position:0% +epsilon. Yeah. Yeah. + + + align:start position:0% +epsilon. Yeah. Yeah. +>> Anything with that first? + + align:start position:0% +>> Anything with that first? + + + align:start position:0% +>> Anything with that first? +>> That's not a problem, right? But it's + + align:start position:0% +>> That's not a problem, right? But it's + + + align:start position:0% +>> That's not a problem, right? But it's +just like if you give me an epsilon, + + align:start position:0% +just like if you give me an epsilon, + + + align:start position:0% +just like if you give me an epsilon, +then I have to pick a a delta. And + + align:start position:0% +then I have to pick a a delta. And + + + align:start position:0% +then I have to pick a a delta. And +typically the delta will depend on + + align:start position:0% +typically the delta will depend on + + + align:start position:0% +typically the delta will depend on +epsilon. + + align:start position:0% +epsilon. + + + align:start position:0% +epsilon. +Typically, it also depends on x. Let me + + align:start position:0% +Typically, it also depends on x. Let me + + + align:start position:0% +Typically, it also depends on x. Let me +give you an example of the last. I don't + + align:start position:0% +give you an example of the last. I don't + + + align:start position:0% +give you an example of the last. I don't +think I I I might not get to to proving + + align:start position:0% +think I I I might not get to to proving + + + align:start position:0% +think I I I might not get to to proving +this, but that's fine. I mean they + + align:start position:0% +this, but that's fine. I mean they + + + align:start position:0% +this, but that's fine. I mean they +actually the proof I'm not even sure I + + align:start position:0% +actually the proof I'm not even sure I + + + align:start position:0% +actually the proof I'm not even sure I +would go through it but the proof is if + + align:start position:0% +would go through it but the proof is if + + + align:start position:0% +would go through it but the proof is if +maybe maybe if I have a minutes I will + + align:start position:0% +maybe maybe if I have a minutes I will + + + align:start position:0% +maybe maybe if I have a minutes I will +talk about one of them. + + align:start position:0% +talk about one of them. + + + align:start position:0% +talk about one of them. +So let me give you an example also where + + align:start position:0% +So let me give you an example also where + + + align:start position:0% +So let me give you an example also where +so typically + + align:start position:0% +so typically + + + align:start position:0% +so typically +typically it's it's highly unusual in + + align:start position:0% +typically it's it's highly unusual in + + + align:start position:0% +typically it's it's highly unusual in +the first example with a constant + + align:start position:0% +the first example with a constant + + + align:start position:0% +the first example with a constant +function that it doesn't really matter + + align:start position:0% +function that it doesn't really matter + + + align:start position:0% +function that it doesn't really matter +you could pick delta anything. Okay. Now + + align:start position:0% +you could pick delta anything. Okay. Now + + + align:start position:0% +you could pick delta anything. Okay. Now +suppose you're looking at the function f + + align:start position:0% +suppose you're looking at the function f + + + align:start position:0% +suppose you're looking at the function f +ofx = 1 /x. This is a rational function + + align:start position:0% +ofx = 1 /x. This is a rational function + + + align:start position:0% +ofx = 1 /x. This is a rational function +because it's a polomial. In that case + + align:start position:0% +because it's a polomial. In that case + + + align:start position:0% +because it's a polomial. In that case +the polomial in the denominator is the + + align:start position:0% +the polomial in the denominator is the + + + align:start position:0% +the polomial in the denominator is the +constant function one and then the + + align:start position:0% +constant function one and then the + + + align:start position:0% +constant function one and then the +denominator is is is x. If you're + + align:start position:0% +denominator is is is x. If you're + + + align:start position:0% +denominator is is is x. If you're +looking at this function let's just look + + align:start position:0% +looking at this function let's just look + + + align:start position:0% +looking at this function let's just look +at this function where it's pos strictly + + align:start position:0% +at this function where it's pos strictly + + + align:start position:0% +at this function where it's pos strictly +positive. Right? And then you see now + + align:start position:0% +positive. Right? And then you see now + + + align:start position:0% +positive. Right? And then you see now +the graphs looks basically like this. + + align:start position:0% +the graphs looks basically like this. + + + align:start position:0% +the graphs looks basically like this. +So in particular if you go close to zero + + align:start position:0% +So in particular if you go close to zero + + + align:start position:0% +So in particular if you go close to zero +it's not defined as zero but if you go + + align:start position:0% +it's not defined as zero but if you go + + + align:start position:0% +it's not defined as zero but if you go +close to zero then the image varies a + + align:start position:0% +close to zero then the image varies a + + + align:start position:0% +close to zero then the image varies a +lot right. So if you take some fixed + + align:start position:0% +lot right. So if you take some fixed + + + align:start position:0% +lot right. So if you take some fixed +thing here suppose you take suppose you + + align:start position:0% +thing here suppose you take suppose you + + + align:start position:0% +thing here suppose you take suppose you +take suppose you take you want to prove + + align:start position:0% +take suppose you take you want to prove + + + align:start position:0% +take suppose you take you want to prove +that it's continuous at some extreme. + + align:start position:0% +that it's continuous at some extreme. + + + align:start position:0% +that it's continuous at some extreme. +So this means that you have to pick some + + align:start position:0% +So this means that you have to pick some + + + align:start position:0% +So this means that you have to pick some +delta. So given an epsilon you have to + + align:start position:0% +delta. So given an epsilon you have to + + + align:start position:0% +delta. So given an epsilon you have to +pick a delta. So that if you are in this + + align:start position:0% +pick a delta. So that if you are in this + + + align:start position:0% +pick a delta. So that if you are in this +little interval then image lie in that + + align:start position:0% +little interval then image lie in that + + + align:start position:0% +little interval then image lie in that +little interval. But you see that as x0 + + align:start position:0% +little interval. But you see that as x0 + + + align:start position:0% +little interval. But you see that as x0 +becomes very close to zero then in any + + align:start position:0% +becomes very close to zero then in any + + + align:start position:0% +becomes very close to zero then in any +small interval the function varies a + + align:start position:0% +small interval the function varies a + + + align:start position:0% +small interval the function varies a +lot. So this means that that if if you + + align:start position:0% +lot. So this means that that if if you + + + align:start position:0% +lot. So this means that that if if you +take some fixed epsilon + + align:start position:0% +take some fixed epsilon + + + align:start position:0% +take some fixed epsilon +then you expect that if the x0 was close + + align:start position:0% +then you expect that if the x0 was close + + + align:start position:0% +then you expect that if the x0 was close +to zero then the delta had to be really + + align:start position:0% +to zero then the delta had to be really + + + align:start position:0% +to zero then the delta had to be really +really really small right for this to + + align:start position:0% +really really small right for this to + + + align:start position:0% +really really small right for this to +work right so typically delta depends + + align:start position:0% +work right so typically delta depends + + + align:start position:0% +work right so typically delta depends +not just on epsilon which it's I mean + + align:start position:0% +not just on epsilon which it's I mean + + + align:start position:0% +not just on epsilon which it's I mean +it's highly unusual it doesn't it also + + align:start position:0% +it's highly unusual it doesn't it also + + + align:start position:0% +it's highly unusual it doesn't it also +depends on x and in fact if it doesn't + + align:start position:0% +depends on x and in fact if it doesn't + + + align:start position:0% +depends on x and in fact if it doesn't +depend on x or extra then it has a + + align:start position:0% +depend on x or extra then it has a + + + align:start position:0% +depend on x or extra then it has a +particular name. We'll get to that + + align:start position:0% +particular name. We'll get to that + + + align:start position:0% +particular name. We'll get to that +later. It's called uniform continuity. + + align:start position:0% +later. It's called uniform continuity. + + + align:start position:0% +later. It's called uniform continuity. +Uniform continuity have some nice extra + + align:start position:0% +Uniform continuity have some nice extra + + + align:start position:0% +Uniform continuity have some nice extra +properties + + align:start position:0% +properties + + + align:start position:0% +properties +and and and and you will see later on + + align:start position:0% +and and and and you will see later on + + + align:start position:0% +and and and and you will see later on +that there's a good reason why the + + align:start position:0% +that there's a good reason why the + + + align:start position:0% +that there's a good reason why the +domain here was did not include zero. If + + align:start position:0% +domain here was did not include zero. If + + + align:start position:0% +domain here was did not include zero. If +somehow this is would have been a + + align:start position:0% +somehow this is would have been a + + + align:start position:0% +somehow this is would have been a +continuous function defined on an + + align:start position:0% +continuous function defined on an + + + align:start position:0% +continuous function defined on an +interval that included the end point + + align:start position:0% +interval that included the end point + + + align:start position:0% +interval that included the end point +then actually it would automatically be + + align:start position:0% +then actually it would automatically be + + + align:start position:0% +then actually it would automatically be +uniform continuous. So so it was the + + align:start position:0% +uniform continuous. So so it was the + + + align:start position:0% +uniform continuous. So so it was the +good reason this example here it didn't + + align:start position:0% +good reason this example here it didn't + + + align:start position:0% +good reason this example here it didn't +include the the the point zero. Okay. + + align:start position:0% +include the the the point zero. Okay. + + + align:start position:0% +include the the the point zero. Okay. +Now let me just so I have like three + + align:start position:0% +Now let me just so I have like three + + + align:start position:0% +Now let me just so I have like three +minutes left. Let me just talk about + + align:start position:0% +minutes left. Let me just talk about + + + align:start position:0% +minutes left. Let me just talk about +one particular of these like the first + + align:start position:0% +one particular of these like the first + + + align:start position:0% +one particular of these like the first +one and the second one super easy and + + align:start position:0% +one and the second one super easy and + + + align:start position:0% +one and the second one super easy and +the third one is also easy but and it + + align:start position:0% +the third one is also easy but and it + + + align:start position:0% +the third one is also easy but and it +uses exactly the same trick that we + + align:start position:0% +uses exactly the same trick that we + + + align:start position:0% +uses exactly the same trick that we +looked at before. So let me just talk + + align:start position:0% +looked at before. So let me just talk + + + align:start position:0% +looked at before. So let me just talk +about that for a minute just because + + align:start position:0% +about that for a minute just because + + + align:start position:0% +about that for a minute just because +it's it's it's a little bit more + + align:start position:0% +it's it's it's a little bit more + + + align:start position:0% +it's it's it's a little bit more +interesting than one and two is is + + align:start position:0% +interesting than one and two is is + + + align:start position:0% +interesting than one and two is is +barely interesting. So suppose I'm + + align:start position:0% +barely interesting. So suppose I'm + + + align:start position:0% +barely interesting. So suppose I'm +looking at the product of these two + + align:start position:0% +looking at the product of these two + + + align:start position:0% +looking at the product of these two +functions + + align:start position:0% + + + + align:start position:0% + +and you know so remember that you give + + align:start position:0% +and you know so remember that you give + + + align:start position:0% +and you know so remember that you give +me an epsilon I had to find a delta so I + + align:start position:0% +me an epsilon I had to find a delta so I + + + align:start position:0% +me an epsilon I had to find a delta so I +have to find a delta so that this + + align:start position:0% +have to find a delta so that this + + + align:start position:0% +have to find a delta so that this +difference here + + align:start position:0% +difference here + + + align:start position:0% +difference here +is smaller + + align:start position:0% +is smaller + + + align:start position:0% +is smaller +I want to find a delta so that if x + + align:start position:0% +I want to find a delta so that if x + + + align:start position:0% +I want to find a delta so that if x +minus x0 is smaller if it's smaller than + + align:start position:0% +minus x0 is smaller if it's smaller than + + + align:start position:0% +minus x0 is smaller if it's smaller than +delta then this difference here is + + align:start position:0% +delta then this difference here is + + + align:start position:0% +delta then this difference here is +smaller than epsilon right that's what + + align:start position:0% +smaller than epsilon right that's what + + + align:start position:0% +smaller than epsilon right that's what +I'm supposed to do + + align:start position:0% +I'm supposed to do + + + align:start position:0% +I'm supposed to do +just knowing that f and g are continuous + + align:start position:0% +just knowing that f and g are continuous + + + align:start position:0% +just knowing that f and g are continuous +right and so I do so this just like when + + align:start position:0% +right and so I do so this just like when + + + align:start position:0% +right and so I do so this just like when +we had this for sequences + + align:start position:0% +we had this for sequences + + + align:start position:0% +we had this for sequences +the similar thing for sequences it's too + + align:start position:0% +the similar thing for sequences it's too + + + align:start position:0% +the similar thing for sequences it's too +much it's too complicated if you just + + align:start position:0% +much it's too complicated if you just + + + align:start position:0% +much it's too complicated if you just +look at like this. So what you do is + + align:start position:0% +look at like this. So what you do is + + + align:start position:0% +look at like this. So what you do is +that you take f ofx times g of x. You + + align:start position:0% +that you take f ofx times g of x. You + + + align:start position:0% +that you take f ofx times g of x. You +insert something and so you insert. It + + align:start position:0% +insert something and so you insert. It + + + align:start position:0% +insert something and so you insert. It +doesn't really matter which way you do + + align:start position:0% +doesn't really matter which way you do + + + align:start position:0% +doesn't really matter which way you do +it, but this is like halfway between + + align:start position:0% +it, but this is like halfway between + + + align:start position:0% +it, but this is like halfway between +this and that where you take one point + + align:start position:0% +this and that where you take one point + + + align:start position:0% +this and that where you take one point +to be x0 the other two x. Of course you + + align:start position:0% +to be x0 the other two x. Of course you + + + align:start position:0% +to be x0 the other two x. Of course you +didn't have that. So you have to add it + + align:start position:0% +didn't have that. So you have to add it + + + align:start position:0% +didn't have that. So you have to add it +again. + + align:start position:0% +again. + + + align:start position:0% +again. +But now the thing is that what you've + + align:start position:0% +But now the thing is that what you've + + + align:start position:0% +But now the thing is that what you've +done here is you sort of have split the + + align:start position:0% +done here is you sort of have split the + + + align:start position:0% +done here is you sort of have split the +difference if you will. + + align:start position:0% + + + + align:start position:0% + +And so now when you want to estimate + + align:start position:0% +And so now when you want to estimate + + + align:start position:0% +And so now when you want to estimate +this you estimate this thing here first. + + align:start position:0% +this you estimate this thing here first. + + + align:start position:0% +this you estimate this thing here first. +So this is g of x * f ofx + + align:start position:0% +So this is g of x * f ofx + + + align:start position:0% +So this is g of x * f ofx +- f of x0 + + align:start position:0% +- f of x0 + + + align:start position:0% +- f of x0 +and you take the absolute value of this + + align:start position:0% +and you take the absolute value of this + + + align:start position:0% +and you take the absolute value of this +plus and then this here here you can + + align:start position:0% +plus and then this here here you can + + + align:start position:0% +plus and then this here here you can +factor out f of x0 + + align:start position:0% + + + + align:start position:0% + +uh g of x minus g of x0. + + align:start position:0% +uh g of x minus g of x0. + + + align:start position:0% +uh g of x minus g of x0. +And now you see now you can sort of do + + align:start position:0% +And now you see now you can sort of do + + + align:start position:0% +And now you see now you can sort of do +like we did before. This here is now + + align:start position:0% +like we did before. This here is now + + + align:start position:0% +like we did before. This here is now +fixed. So you just you can you can also + + align:start position:0% +fixed. So you just you can you can also + + + align:start position:0% +fixed. So you just you can you can also +take the absolute value sign like that. + + align:start position:0% +take the absolute value sign like that. + + + align:start position:0% +take the absolute value sign like that. +And now this here is like just x here is + + align:start position:0% +And now this here is like just x here is + + + align:start position:0% +And now this here is like just x here is +fixed. So this is just some fixed + + align:start position:0% +fixed. So this is just some fixed + + + align:start position:0% +fixed. So this is just some fixed +number. So this means that this thing + + align:start position:0% +number. So this means that this thing + + + align:start position:0% +number. So this means that this thing +here has to be maybe even smaller + + align:start position:0% +here has to be maybe even smaller + + + align:start position:0% +here has to be maybe even smaller +depending on what this constant is. But + + align:start position:0% +depending on what this constant is. But + + + align:start position:0% +depending on what this constant is. But +that's easy to achieve with some delta. + + align:start position:0% +that's easy to achieve with some delta. + + + align:start position:0% +that's easy to achieve with some delta. +Right? Here it's a little bit more + + align:start position:0% +Right? Here it's a little bit more + + + align:start position:0% +Right? Here it's a little bit more +complicated because this one here is not + + align:start position:0% +complicated because this one here is not + + + align:start position:0% +complicated because this one here is not +fixed. Right? But you have to then say + + align:start position:0% +fixed. Right? But you have to then say + + + align:start position:0% +fixed. Right? But you have to then say +that once you are close to x0 then this + + align:start position:0% +that once you are close to x0 then this + + + align:start position:0% +that once you are close to x0 then this +here there's a bound for this. You see + + align:start position:0% +here there's a bound for this. You see + + + align:start position:0% +here there's a bound for this. You see +it's sort of like what we did before. So + + align:start position:0% +it's sort of like what we did before. So + + + align:start position:0% +it's sort of like what we did before. So +we are out of time so I just leave it + + align:start position:0% +we are out of time so I just leave it + + + align:start position:0% +we are out of time so I just leave it +there. + + align:start position:0% +there. + + + align:start position:0% +there. +So next time we'll talk more about this + + align:start position:0% +So next time we'll talk more about this + + + align:start position:0% +So next time we'll talk more about this +with exponential function. Yeah. So a + + align:start position:0% +with exponential function. Yeah. So a + + + align:start position:0% +with exponential function. Yeah. So a +rational function said to be continuous + + align:start position:0% +rational function said to be continuous + + + align:start position:0% +rational function said to be continuous +or do we not call it continuous? No, a + + align:start position:0% +or do we not call it continuous? No, a + + + align:start position:0% +or do we not call it continuous? No, a +rational function any rational function + + align:start position:0% +rational function any rational function + + + align:start position:0% +rational function any rational function +is continuous. It's defined + + align:start position:0% +is continuous. It's defined + + + align:start position:0% +is continuous. It's defined +at points where the where the polinomial + + align:start position:0% +at points where the where the polinomial + + + align:start position:0% +at points where the where the polinomial +in the denominator + + align:start position:0% +in the denominator + + + align:start position:0% +in the denominator +away from the roots of the of the + + align:start position:0% +away from the roots of the of the + + + align:start position:0% +away from the roots of the of the +polomial in the denominator. + + align:start position:0% +polomial in the denominator. + + + align:start position:0% +polomial in the denominator. +>> It's continuous. What + + align:start position:0% +>> It's continuous. What + + + align:start position:0% +>> It's continuous. What +>> are they said to be continu + + align:start position:0% +>> are they said to be continu + + + align:start position:0% +>> are they said to be continu +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +one what yeah I mean any rational + + align:start position:0% +one what yeah I mean any rational + + + align:start position:0% +one what yeah I mean any rational +function is continuous. It's just not + + align:start position:0% +function is continuous. It's just not + + + align:start position:0% +function is continuous. It's just not +defined at the roots. + + align:start position:0% +defined at the roots. + + + align:start position:0% +defined at the roots. +Okay. Now for some polomium you could + + align:start position:0% +Okay. Now for some polomium you could + + + align:start position:0% +Okay. Now for some polomium you could +some rational functions if you were sort + + align:start position:0% +some rational functions if you were sort + + + align:start position:0% +some rational functions if you were sort +of silly and you wrote a if you wrote + + align:start position:0% +of silly and you wrote a if you wrote + + + align:start position:0% +of silly and you wrote a if you wrote +this thing here right this is a polomial + + align:start position:0% +this thing here right this is a polomial + + + align:start position:0% +this thing here right this is a polomial +that's a polomial this one have a root + + align:start position:0% +that's a polomial this one have a root + + + align:start position:0% +that's a polomial this one have a root +as zero but really this function here + + align:start position:0% +as zero but really this function here + + + align:start position:0% +as zero but really this function here +you would probably think about as being + + align:start position:0% +you would probably think about as being + + + align:start position:0% +you would probably think about as being +the constant function one right so it's + + align:start position:0% +the constant function one right so it's + + + align:start position:0% +the constant function one right so it's +still right but it's not a pure it's + + align:start position:0% +still right but it's not a pure it's + + + align:start position:0% +still right but it's not a pure it's +it's continuous + + align:start position:0% +it's continuous + + + align:start position:0% +it's continuous +away from the root. It doesn't say + + align:start position:0% +away from the root. It doesn't say + + + align:start position:0% +away from the root. It doesn't say +whether it's continuous at the root. + + align:start position:0% +whether it's continuous at the root. + + + align:start position:0% +whether it's continuous at the root. +It's just not defined at the root of the + + align:start position:0% +It's just not defined at the root of the + + + align:start position:0% +It's just not defined at the root of the +denominator. + + align:start position:0% +denominator. + + + align:start position:0% +denominator. +>> Yep. + + align:start position:0% + + + + align:start position:0% + +>> Yeah, that's right. That's right. So + + align:start position:0% +>> Yeah, that's right. That's right. So + + + align:start position:0% +>> Yeah, that's right. That's right. So +that's right. So if you have a polomial + + align:start position:0% +that's right. So if you have a polomial + + + align:start position:0% +that's right. So if you have a polomial +in the denominator, right, there's + + align:start position:0% +in the denominator, right, there's + + + align:start position:0% +in the denominator, right, there's +there's like finite many points where + + align:start position:0% +there's like finite many points where + + + align:start position:0% +there's like finite many points where +where where you have roots and at those + + align:start position:0% +where where you have roots and at those + + + align:start position:0% +where where you have roots and at those +point it's appro defined. You might be + + align:start position:0% +point it's appro defined. You might be + + + align:start position:0% +point it's appro defined. You might be +able to extend it in a continuous way to + + align:start position:0% +able to extend it in a continuous way to + + + align:start position:0% +able to extend it in a continuous way to +those points, but typically it's not + + align:start position:0% +those points, but typically it's not + + + align:start position:0% +those points, but typically it's not +defined in those points. \ No newline at end of file diff --git a/Mv2aDOe1o4w.txt b/Mv2aDOe1o4w.txt new file mode 100644 index 0000000000000000000000000000000000000000..63ea482ed162d379dce1e84cef0ca4a19a20b788 --- /dev/null +++ b/Mv2aDOe1o4w.txt @@ -0,0 +1,22595 @@ +align:start position:0% + +so we have uh we're going to spend most + + align:start position:0% +so we have uh we're going to spend most + + + align:start position:0% +so we have uh we're going to spend most +of today debriefing the + + align:start position:0% +of today debriefing the + + + align:start position:0% +of today debriefing the +trip and and + + align:start position:0% +trip and and + + + align:start position:0% +trip and and +uh we have a little uh going to have it + + align:start position:0% +uh we have a little uh going to have it + + + align:start position:0% +uh we have a little uh going to have it +broken down to three parts one is a a + + align:start position:0% +broken down to three parts one is a a + + + align:start position:0% +broken down to three parts one is a a +little reflection experience we want you + + align:start position:0% +little reflection experience we want you + + + align:start position:0% +little reflection experience we want you +to do then we want to do a debrief of + + align:start position:0% +to do then we want to do a debrief of + + + align:start position:0% +to do then we want to do a debrief of +the interviews that happened and then a + + align:start position:0% +the interviews that happened and then a + + + align:start position:0% +the interviews that happened and then a +debrief of the inventory work you did + + align:start position:0% +debrief of the inventory work you did + + + align:start position:0% +debrief of the inventory work you did +and then we're going to do uh kind of + + align:start position:0% +and then we're going to do uh kind of + + + align:start position:0% +and then we're going to do uh kind of +two discussions one a discussion about + + align:start position:0% +two discussions one a discussion about + + + align:start position:0% +two discussions one a discussion about +populationbased approaches to Economic + + align:start position:0% +populationbased approaches to Economic + + + align:start position:0% +populationbased approaches to Economic +Development and then another of kind of + + align:start position:0% +Development and then another of kind of + + + align:start position:0% +Development and then another of kind of +setting up for the work that we have to + + align:start position:0% +setting up for the work that we have to + + + align:start position:0% +setting up for the work that we have to +do that right so those are the kind of + + align:start position:0% +do that right so those are the kind of + + + align:start position:0% +do that right so those are the kind of +five steps we hope to get through today + + align:start position:0% +five steps we hope to get through today + + + align:start position:0% +five steps we hope to get through today +and if we don't get through all of them + + align:start position:0% +and if we don't get through all of them + + + align:start position:0% +and if we don't get through all of them +um we'll you know continue next session + + align:start position:0% +um we'll you know continue next session + + + align:start position:0% +um we'll you know continue next session +I think we have enough time next session + + align:start position:0% +I think we have enough time next session + + + align:start position:0% +I think we have enough time next session +to to sort of complete this this work + + align:start position:0% +to to sort of complete this this work + + + align:start position:0% +to to sort of complete this this work +and cover the the material for the next + + align:start position:0% +and cover the the material for the next + + + align:start position:0% +and cover the the material for the next +session too so uh I need I need a tester + + align:start position:0% +session too so uh I need I need a tester + + + align:start position:0% +session too so uh I need I need a tester +and can you me can you just test that + + align:start position:0% +and can you me can you just test that + + + align:start position:0% +and can you me can you just test that +and see if it'll actually stick on that + + align:start position:0% + + + + align:start position:0% + +board yeah will if you push hard huh you + + align:start position:0% +board yeah will if you push hard huh you + + + align:start position:0% +board yeah will if you push hard huh you +push if you push hard it'll stick okay + + align:start position:0% +push if you push hard it'll stick okay + + + align:start position:0% +push if you push hard it'll stick okay +good okay + + align:start position:0% +good okay + + + align:start position:0% +good okay +so can people just take + + align:start position:0% +so can people just take + + + align:start position:0% +so can people just take +like a few of these like six or seven or + + align:start position:0% +like a few of these like six or seven or + + + align:start position:0% +like a few of these like six or seven or +so of those + + align:start position:0% +so of those + + + align:start position:0% +so of those +uh then pass him + + align:start position:0% + + + + align:start position:0% + +around so take a set and then pass him + + align:start position:0% +around so take a set and then pass him + + + align:start position:0% +around so take a set and then pass him +around then we have supportive tape in + + align:start position:0% +around then we have supportive tape in + + + align:start position:0% +around then we have supportive tape in +case we need + + align:start position:0% + + + + align:start position:0% + +it and also you might want to get out a + + align:start position:0% +it and also you might want to get out a + + + align:start position:0% +it and also you might want to get out a +piece of + + align:start position:0% + + + + align:start position:0% + +paper everybody got a stack everyone + + align:start position:0% +paper everybody got a stack everyone + + + align:start position:0% +paper everybody got a stack everyone +have a stack good James you have a stack + + align:start position:0% +have a stack good James you have a stack + + + align:start position:0% +have a stack good James you have a stack +I don't have a stack + + align:start position:0% +I don't have a stack + + + align:start position:0% +I don't have a stack +oh + + align:start position:0% + + + + align:start position:0% + +good a want some sure only one color oh + + align:start position:0% +good a want some sure only one color oh + + + align:start position:0% +good a want some sure only one color oh +that's more color would you like Green + + align:start position:0% + + + + align:start position:0% + +instead color you want great okay so + + align:start position:0% +instead color you want great okay so + + + align:start position:0% +instead color you want great okay so +there are two parts to this and I want + + align:start position:0% +there are two parts to this and I want + + + align:start position:0% +there are two parts to this and I want +people to kind of concentrate on for the + + align:start position:0% +people to kind of concentrate on for the + + + align:start position:0% +people to kind of concentrate on for the +next like five minutes or so so + + align:start position:0% +next like five minutes or so so + + + align:start position:0% +next like five minutes or so so +um and that's why I asked you to + + align:start position:0% +um and that's why I asked you to + + + align:start position:0% +um and that's why I asked you to +actually have a piece of paper out then + + align:start position:0% +actually have a piece of paper out then + + + align:start position:0% +actually have a piece of paper out then +also have one of these the piece of + + align:start position:0% +also have one of these the piece of + + + align:start position:0% +also have one of these the piece of +paper you all have to share with us but + + align:start position:0% +paper you all have to share with us but + + + align:start position:0% +paper you all have to share with us but +these we're going to put up what I'd + + align:start position:0% +these we're going to put up what I'd + + + align:start position:0% +these we're going to put up what I'd +like you to do is just uh take a few + + align:start position:0% +like you to do is just uh take a few + + + align:start position:0% +like you to do is just uh take a few +minutes and write down from your + + align:start position:0% +minutes and write down from your + + + align:start position:0% +minutes and write down from your +perspective kind of five observations + + align:start position:0% +perspective kind of five observations + + + align:start position:0% +perspective kind of five observations +that you thought were the most important + + align:start position:0% +that you thought were the most important + + + align:start position:0% +that you thought were the most important +observations you made during your trip + + align:start position:0% +observations you made during your trip + + + align:start position:0% +observations you made during your trip +in Springfield just Things You observe + + align:start position:0% +in Springfield just Things You observe + + + align:start position:0% +in Springfield just Things You observe +saw things that happen + + align:start position:0% +saw things that happen + + + align:start position:0% +saw things that happen +Okay and + + align:start position:0% +Okay and + + + align:start position:0% +Okay and +it can be from any perspective it could + + align:start position:0% +it can be from any perspective it could + + + align:start position:0% +it can be from any perspective it could +be something it may not be related to + + align:start position:0% +be something it may not be related to + + + align:start position:0% +be something it may not be related to +Economic Development it could just be + + align:start position:0% +Economic Development it could just be + + + align:start position:0% +Economic Development it could just be +related to relationships whatever it is + + align:start position:0% +related to relationships whatever it is + + + align:start position:0% +related to relationships whatever it is +but you know try to think of from your + + align:start position:0% +but you know try to think of from your + + + align:start position:0% +but you know try to think of from your +own perspective there five really kind + + align:start position:0% +own perspective there five really kind + + + align:start position:0% +own perspective there five really kind +of + + align:start position:0% +of + + + align:start position:0% +of +key Impressions things you came back + + align:start position:0% +key Impressions things you came back + + + align:start position:0% +key Impressions things you came back +from in terms of your visit to the North + + align:start position:0% +from in terms of your visit to the North + + + align:start position:0% +from in terms of your visit to the North +End + + align:start position:0% +End + + + align:start position:0% +End +okay and then after you get those five + + align:start position:0% +okay and then after you get those five + + + align:start position:0% +okay and then after you get those five +down I'm going to ask you to do one + + align:start position:0% +down I'm going to ask you to do one + + + align:start position:0% +down I'm going to ask you to do one +other thing okay so I'm going to give + + align:start position:0% +other thing okay so I'm going to give + + + align:start position:0% +other thing okay so I'm going to give +you a few minutes to do that + + align:start position:0% +you a few minutes to do that + + + align:start position:0% +you a few minutes to do that +one pet please + + align:start position:0% +one pet please + + + align:start position:0% +one pet please +one yeah one ped on these + + align:start position:0% + + + + align:start position:0% + +people finished + + align:start position:0% + + + + align:start position:0% + +TR + + align:start position:0% + + + + align:start position:0% + +almost + + align:start position:0% + + + + align:start position:0% + +finished D just right next to it + + align:start position:0% + + + + align:start position:0% + +okay so after you've done + + align:start position:0% + + + + align:start position:0% + +that then in your own note book or + + align:start position:0% +that then in your own note book or + + + align:start position:0% +that then in your own note book or +another piece of paper I want you to + + align:start position:0% +another piece of paper I want you to + + + align:start position:0% +another piece of paper I want you to +write one more + + align:start position:0% +write one more + + + align:start position:0% +write one more +thing given your a whole experience + + align:start position:0% +thing given your a whole experience + + + align:start position:0% +thing given your a whole experience +there giving your + + align:start position:0% +there giving your + + + align:start position:0% +there giving your +experience that uh in the North End I + + align:start position:0% +experience that uh in the North End I + + + align:start position:0% +experience that uh in the North End I +want you to just kind of think back to + + align:start position:0% +want you to just kind of think back to + + + align:start position:0% +want you to just kind of think back to +any other experiences or events or uh + + align:start position:0% +any other experiences or events or uh + + + align:start position:0% +any other experiences or events or uh +places you know + + align:start position:0% +places you know + + + align:start position:0% +places you know +of that when you were there it reminded + + align:start position:0% +of that when you were there it reminded + + + align:start position:0% +of that when you were there it reminded +you of it's kind of like wow you know + + align:start position:0% +you of it's kind of like wow you know + + + align:start position:0% +you of it's kind of like wow you know +when I was walking around this + + align:start position:0% +when I was walking around this + + + align:start position:0% +when I was walking around this +experience or this event or this thing + + align:start position:0% +experience or this event or this thing + + + align:start position:0% +experience or this event or this thing +kind of popped up in my mind it could be + + align:start position:0% +kind of popped up in my mind it could be + + + align:start position:0% +kind of popped up in my mind it could be +something you actually live through or + + align:start position:0% +something you actually live through or + + + align:start position:0% +something you actually live through or +something you maybe have read about but + + align:start position:0% +something you maybe have read about but + + + align:start position:0% +something you maybe have read about but +there was a connection with something + + align:start position:0% +there was a connection with something + + + align:start position:0% +there was a connection with something +outside of the north end is that clear + + align:start position:0% +outside of the north end is that clear + + + align:start position:0% +outside of the north end is that clear +what I mean and just jot yourself a note + + align:start position:0% +what I mean and just jot yourself a note + + + align:start position:0% +what I mean and just jot yourself a note +down about what that + + align:start position:0% +down about what that + + + align:start position:0% +down about what that +was don't put it on no just totally + + align:start position:0% +was don't put it on no just totally + + + align:start position:0% +was don't put it on no just totally +independent of those things it doesn't + + align:start position:0% +independent of those things it doesn't + + + align:start position:0% +independent of those things it doesn't +have anything it doesn't have to have + + align:start position:0% +have anything it doesn't have to have + + + align:start position:0% +have anything it doesn't have to have +anything to do with those cards + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +okay is everybody + + align:start position:0% + + + + align:start position:0% + +ready + + align:start position:0% +ready + + + align:start position:0% +ready +so what I'm looking for at this point in + + align:start position:0% +so what I'm looking for at this point in + + + align:start position:0% +so what I'm looking for at this point in +time is + + align:start position:0% +time is + + + align:start position:0% +time is +volunteers person to come up and just + + align:start position:0% +volunteers person to come up and just + + + align:start position:0% +volunteers person to come up and just +tell us quickly about the five things + + align:start position:0% +tell us quickly about the five things + + + align:start position:0% +tell us quickly about the five things +that you have that you laid out and what + + align:start position:0% +that you have that you laid out and what + + + align:start position:0% +that you have that you laid out and what +I'd like you to do is when you do it + + align:start position:0% +I'd like you to do is when you do it + + + align:start position:0% +I'd like you to do is when you do it +if the thing you saw was positive you + + align:start position:0% +if the thing you saw was positive you + + + align:start position:0% +if the thing you saw was positive you +thought it was a positive thing + + align:start position:0% +thought it was a positive thing + + + align:start position:0% +thought it was a positive thing +experience it's all subjective put it on + + align:start position:0% +experience it's all subjective put it on + + + align:start position:0% +experience it's all subjective put it on +this board if it's something that you + + align:start position:0% +this board if it's something that you + + + align:start position:0% +this board if it's something that you +thought was negative put it on this + + align:start position:0% +thought was negative put it on this + + + align:start position:0% +thought was negative put it on this +board + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +yeah okay you know + + align:start position:0% + + + + align:start position:0% + +what it's kind of like + + align:start position:0% + + + + align:start position:0% + +okay neutral gets the biggest board only + + align:start position:0% +okay neutral gets the biggest board only + + + align:start position:0% +okay neutral gets the biggest board only +because that's not a suggestion about + + align:start position:0% +because that's not a suggestion about + + + align:start position:0% +because that's not a suggestion about +where you place things neutral and mixed + + align:start position:0% +where you place things neutral and mixed + + + align:start position:0% +where you place things neutral and mixed +bag this is neutral mixed bag bag no one + + align:start position:0% +bag this is neutral mixed bag bag no one + + + align:start position:0% +bag this is neutral mixed bag bag no one +side is neutral one side is mix bag oh + + align:start position:0% +side is neutral one side is mix bag oh + + + align:start position:0% +side is neutral one side is mix bag oh +okay mixed bag okay you want to give us + + align:start position:0% +okay mixed bag okay you want to give us + + + align:start position:0% +okay mixed bag okay you want to give us +a little sign write us one that says + + align:start position:0% +a little sign write us one that says + + + align:start position:0% +a little sign write us one that says +mixed bag one says neutral and then + + align:start position:0% +mixed bag one says neutral and then + + + align:start position:0% +mixed bag one says neutral and then +we'll make this one over here + + align:start position:0% +we'll make this one over here + + + align:start position:0% +we'll make this one over here +positive + + align:start position:0% + + + + align:start position:0% + +okay just a remind everyone you got a + + align:start position:0% +okay just a remind everyone you got a + + + align:start position:0% +okay just a remind everyone you got a +mix bag neutral neutral okay here's + + align:start position:0% +mix bag neutral neutral okay here's + + + align:start position:0% +mix bag neutral neutral okay here's +neutral and give us a mixed bag so who + + align:start position:0% +neutral and give us a mixed bag so who + + + align:start position:0% +neutral and give us a mixed bag so who +wants to go first + + align:start position:0% + + + + align:start position:0% + +okay this is like a graduate class we + + align:start position:0% +okay this is like a graduate class we + + + align:start position:0% +okay this is like a graduate class we +don't have to point people out right + + align:start position:0% +don't have to point people out right + + + align:start position:0% +don't have to point people out right +okay okay let's go come on up and put + + align:start position:0% +okay okay let's go come on up and put + + + align:start position:0% +okay okay let's go come on up and put +your things in case you don't stick just + + align:start position:0% +your things in case you don't stick just + + + align:start position:0% +your things in case you don't stick just +grab a piece of tape to put them up + + align:start position:0% +grab a piece of tape to put them up + + + align:start position:0% +grab a piece of tape to put them up +there + + align:start position:0% + + + + align:start position:0% + +okay okay the first thing was was very + + align:start position:0% +okay okay the first thing was was very + + + align:start position:0% +okay okay the first thing was was very +strong sociocultural + + align:start position:0% + + + + align:start position:0% + +infrastructure sry could you repeat that + + align:start position:0% +infrastructure sry could you repeat that + + + align:start position:0% +infrastructure sry could you repeat that +I a strong soci cultural infrastructure + + align:start position:0% +I a strong soci cultural infrastructure + + + align:start position:0% +I a strong soci cultural infrastructure +um underutilized parks and Open + + align:start position:0% +um underutilized parks and Open + + + align:start position:0% +um underutilized parks and Open +Spaces here I guess because is it + + align:start position:0% +Spaces here I guess because is it + + + align:start position:0% +Spaces here I guess because is it +positive + + align:start position:0% +positive + + + align:start position:0% +positive +like + + align:start position:0% +like + + + align:start position:0% +like +there so it could be a mixed bag could + + align:start position:0% +there so it could be a mixed bag could + + + align:start position:0% +there so it could be a mixed bag could +be a mixed + + align:start position:0% + + + + align:start position:0% + +bag you guys you guys would be + + align:start position:0% +bag you guys you guys would be + + + align:start position:0% +bag you guys you guys would be +helpful we could vote in + + align:start position:0% +helpful we could vote in + + + align:start position:0% +helpful we could vote in +a A diversity in housing is stock with + + align:start position:0% +a A diversity in housing is stock with + + + align:start position:0% +a A diversity in housing is stock with +the strong presence of public + + align:start position:0% +the strong presence of public + + + align:start position:0% +the strong presence of public +housing you can put it where you think + + align:start position:0% +housing you can put it where you think + + + align:start position:0% +housing you can put it where you think +it's + + align:start position:0% + + + + align:start position:0% + +wrong it's + + align:start position:0% +wrong it's + + + align:start position:0% +wrong it's +okay stronger presence of medical + + align:start position:0% + + + + align:start position:0% + +industry + + align:start position:0% + + + + align:start position:0% + +here and + + align:start position:0% +here and + + + align:start position:0% +here and +teral rivers side + + align:start position:0% + + + + align:start position:0% + +what was that last one the riv side the + + align:start position:0% +what was that last one the riv side the + + + align:start position:0% +what was that last one the riv side the +wall the + + align:start position:0% +wall the + + + align:start position:0% +wall the +side that big wall that goes uhhuh cool + + align:start position:0% +side that big wall that goes uhhuh cool + + + align:start position:0% +side that big wall that goes uhhuh cool +now um okay that's fine we're just going + + align:start position:0% +now um okay that's fine we're just going + + + align:start position:0% +now um okay that's fine we're just going +to go through these okay those are + + align:start position:0% + + + + align:start position:0% + +next just jump up you know don't raise + + align:start position:0% +next just jump up you know don't raise + + + align:start position:0% +next just jump up you know don't raise +your hand just jump up and do it you + + align:start position:0% +your hand just jump up and do it you + + + align:start position:0% +your hand just jump up and do it you +know sees the + + align:start position:0% + + + + align:start position:0% + +moment okay uh for first one I have uh + + align:start position:0% +moment okay uh for first one I have uh + + + align:start position:0% +moment okay uh for first one I have uh +that + + align:start position:0% +that + + + align:start position:0% +that +Springfield shows some as a city shows + + align:start position:0% +Springfield shows some as a city shows + + + align:start position:0% +Springfield shows some as a city shows +some economic dynamism and represents + + align:start position:0% +some economic dynamism and represents + + + align:start position:0% +some economic dynamism and represents +potential demand for the work and + + align:start position:0% +potential demand for the work and + + + align:start position:0% +potential demand for the work and +services of the people in the North + + align:start position:0% +services of the people in the North + + + align:start position:0% +services of the people in the North +End um another positive that I had is + + align:start position:0% +End um another positive that I had is + + + align:start position:0% +End um another positive that I had is +that the people in neon are ready to + + align:start position:0% +that the people in neon are ready to + + + align:start position:0% +that the people in neon are ready to +work on this ready to be pretty + + align:start position:0% +work on this ready to be pretty + + + align:start position:0% +work on this ready to be pretty +active um one neutral observation is + + align:start position:0% +active um one neutral observation is + + + align:start position:0% +active um one neutral observation is +that I found it seems that a lot of + + align:start position:0% +that I found it seems that a lot of + + + align:start position:0% +that I found it seems that a lot of +small local businesses are very like + + align:start position:0% +small local businesses are very like + + + align:start position:0% +small local businesses are very like +almost intentionally or at least + + align:start position:0% +almost intentionally or at least + + + align:start position:0% +almost intentionally or at least +knowingly volatile contingency plans + + align:start position:0% +knowingly volatile contingency plans + + + align:start position:0% +knowingly volatile contingency plans +where the owner knows in advance there's + + align:start position:0% +where the owner knows in advance there's + + + align:start position:0% +where the owner knows in advance there's +a high chance it'll close quickly and is + + align:start position:0% +a high chance it'll close quickly and is + + + align:start position:0% +a high chance it'll close quickly and is +not + + align:start position:0% +not + + + align:start position:0% +not +actually trying necessarily or intending + + align:start position:0% +actually trying necessarily or intending + + + align:start position:0% +actually trying necessarily or intending +to make it last a long + + align:start position:0% +to make it last a long + + + align:start position:0% +to make it last a long +time + + align:start position:0% +time + + + align:start position:0% +time +um as a mixed bag I have uh given State + + align:start position:0% +um as a mixed bag I have uh given State + + + align:start position:0% +um as a mixed bag I have uh given State +given take between uh the community and + + align:start position:0% +given take between uh the community and + + + align:start position:0% +given take between uh the community and +Bay State Medical so while there's a + + align:start position:0% +Bay State Medical so while there's a + + + align:start position:0% +Bay State Medical so while there's a +positive that I think B state is willing + + align:start position:0% +positive that I think B state is willing + + + align:start position:0% +positive that I think B state is willing +to come to the table with people there + + align:start position:0% +to come to the table with people there + + + align:start position:0% +to come to the table with people there +I'm not sure that there's that anyone's + + align:start position:0% +I'm not sure that there's that anyone's + + + align:start position:0% +I'm not sure that there's that anyone's +operating with a very coherent game plan + + align:start position:0% +operating with a very coherent game plan + + + align:start position:0% +operating with a very coherent game plan +of what the community wants from B + + align:start position:0% +of what the community wants from B + + + align:start position:0% +of what the community wants from B +State uh another mixed bag in a way is + + align:start position:0% +State uh another mixed bag in a way is + + + align:start position:0% +State uh another mixed bag in a way is +that there's it sounds negative the way + + align:start position:0% +that there's it sounds negative the way + + + align:start position:0% +that there's it sounds negative the way +I wrote it because I wrote language Gap + + align:start position:0% +I wrote it because I wrote language Gap + + + align:start position:0% +I wrote it because I wrote language Gap +but I think it's a mixed bag also + + align:start position:0% +but I think it's a mixed bag also + + + align:start position:0% +but I think it's a mixed bag also +because it shows some internal Unity + + align:start position:0% +because it shows some internal Unity + + + align:start position:0% +because it shows some internal Unity +cultural Unity um and then another + + align:start position:0% +cultural Unity um and then another + + + align:start position:0% +cultural Unity um and then another +positive was uh that the North End has + + align:start position:0% +positive was uh that the North End has + + + align:start position:0% +positive was uh that the North End has +been identified by the state as an + + align:start position:0% +been identified by the state as an + + + align:start position:0% +been identified by the state as an +anchor neighborhood so it shows that the + + align:start position:0% +anchor neighborhood so it shows that the + + + align:start position:0% +anchor neighborhood so it shows that the +state ready maybe to 20 up to the + + align:start position:0% + + + + align:start position:0% + +area I'm going to put this one in + + align:start position:0% +area I'm going to put this one in + + + align:start position:0% +area I'm going to put this one in +positive that I think it really was was + + align:start position:0% +positive that I think it really was was + + + align:start position:0% +positive that I think it really was was +a bit intimidating I said we received a + + align:start position:0% +a bit intimidating I said we received a + + + align:start position:0% +a bit intimidating I said we received a +very warm welcome in the north end but I + + align:start position:0% +very warm welcome in the north end but I + + + align:start position:0% +very warm welcome in the north end but I +think that it was still intimidating + + align:start position:0% +think that it was still intimidating + + + align:start position:0% +think that it was still intimidating +because it seemed + + align:start position:0% +because it seemed + + + align:start position:0% +because it seemed +like uh symptomatic of expectations of + + align:start position:0% +like uh symptomatic of expectations of + + + align:start position:0% +like uh symptomatic of expectations of +us uh this is definitely a mixed bag is + + align:start position:0% +us uh this is definitely a mixed bag is + + + align:start position:0% +us uh this is definitely a mixed bag is +I said we seem to have joined the + + align:start position:0% +I said we seem to have joined the + + + align:start position:0% +I said we seem to have joined the +conversation concerning the future of + + align:start position:0% +conversation concerning the future of + + + align:start position:0% +conversation concerning the future of +the north and at a very Advanced + + align:start position:0% +the north and at a very Advanced + + + align:start position:0% +the north and at a very Advanced +stage um this is I think positive could + + align:start position:0% +stage um this is I think positive could + + + align:start position:0% +stage um this is I think positive could +be considered mix bag too uh neon + + align:start position:0% +be considered mix bag too uh neon + + + align:start position:0% +be considered mix bag too uh neon +workers are deeply concerned about + + align:start position:0% +workers are deeply concerned about + + + align:start position:0% +workers are deeply concerned about +environmental and Public Health in the + + align:start position:0% +environmental and Public Health in the + + + align:start position:0% +environmental and Public Health in the +North + + align:start position:0% +North + + + align:start position:0% +North +End last + + align:start position:0% +End last + + + align:start position:0% +End last +I would say more + + align:start position:0% +I would say more + + + align:start position:0% +I would say more +negative um I felt that Jeff had really + + align:start position:0% +negative um I felt that Jeff had really + + + align:start position:0% +negative um I felt that Jeff had really +sort of impenetrable set of thoughts + + align:start position:0% +sort of impenetrable set of thoughts + + + align:start position:0% +sort of impenetrable set of thoughts +about what the ideal relationship + + align:start position:0% +about what the ideal relationship + + + align:start position:0% +about what the ideal relationship +between the Northend and Bas state was + + align:start position:0% +between the Northend and Bas state was + + + align:start position:0% +between the Northend and Bas state was +and I really couldn't get much of a + + align:start position:0% +and I really couldn't get much of a + + + align:start position:0% +and I really couldn't get much of a +handle of the way he thought about that + + align:start position:0% +handle of the way he thought about that + + + align:start position:0% +handle of the way he thought about that +relationship as it might move forward or + + align:start position:0% +relationship as it might move forward or + + + align:start position:0% +relationship as it might move forward or +does it not move forward he of talked + + align:start position:0% +does it not move forward he of talked + + + align:start position:0% +does it not move forward he of talked +about but wouldn't get into the details + + align:start position:0% +about but wouldn't get into the details + + + align:start position:0% +about but wouldn't get into the details +about seing rightwood from B St um so I + + align:start position:0% +about seing rightwood from B St um so I + + + align:start position:0% +about seing rightwood from B St um so I +feel that till that black box is somehow + + align:start position:0% +feel that till that black box is somehow + + + align:start position:0% +feel that till that black box is somehow +cracked open it's it's negative and then + + align:start position:0% +cracked open it's it's negative and then + + + align:start position:0% +cracked open it's it's negative and then +I thought the highway interchange is + + align:start position:0% +I thought the highway interchange is + + + align:start position:0% +I thought the highway interchange is +very dangerous which one the + + align:start position:0% + + + + align:start position:0% + +highway I have a + + align:start position:0% +highway I have a + + + align:start position:0% +highway I have a +few but first I found a wide range of + + align:start position:0% +few but first I found a wide range of + + + align:start position:0% +few but first I found a wide range of +community activities going on in the + + align:start position:0% +community activities going on in the + + + align:start position:0% +community activities going on in the +area + + align:start position:0% + + + + align:start position:0% + +iot just speak up just a little louder + + align:start position:0% +iot just speak up just a little louder + + + align:start position:0% +iot just speak up just a little louder +I'm having a hard time hearing + + align:start position:0% +I'm having a hard time hearing + + + align:start position:0% +I'm having a hard time hearing +and um there was an absence of close + + align:start position:0% +and um there was an absence of close + + + align:start position:0% +and um there was an absence of close +Community initiatives although I saw a + + align:start position:0% +Community initiatives although I saw a + + + align:start position:0% +Community initiatives although I saw a +lot of activities going on within the + + align:start position:0% +lot of activities going on within the + + + align:start position:0% +lot of activities going on within the +community I asked sever people and they + + align:start position:0% +community I asked sever people and they + + + align:start position:0% +community I asked sever people and they +didn't see that there were um a lot + + align:start position:0% +didn't see that there were um a lot + + + align:start position:0% +didn't see that there were um a lot +going on with other + + align:start position:0% +going on with other + + + align:start position:0% +going on with other +so + + align:start position:0% + + + + align:start position:0% + +that's and then um somebody told me that + + align:start position:0% +that's and then um somebody told me that + + + align:start position:0% +that's and then um somebody told me that +the health issue was a serious concern + + align:start position:0% +the health issue was a serious concern + + + align:start position:0% +the health issue was a serious concern +that they have the highest + + align:start position:0% +that they have the highest + + + align:start position:0% +that they have the highest +industrial um in the area okay this + + align:start position:0% + + + + align:start position:0% + +is and then I thought there's not enough + + align:start position:0% +is and then I thought there's not enough + + + align:start position:0% +is and then I thought there's not enough +internal demand within the the community + + align:start position:0% +internal demand within the the community + + + align:start position:0% +internal demand within the the community +like I didn't see that there was like an + + align:start position:0% +like I didn't see that there was like an + + + align:start position:0% +like I didn't see that there was like an +excess demand for the ex + + align:start position:0% + + + + align:start position:0% + +can I ask a question quick when it says + + align:start position:0% +can I ask a question quick when it says + + + align:start position:0% +can I ask a question quick when it says +n of demand you mean like commercial for + + align:start position:0% +n of demand you mean like commercial for + + + align:start position:0% +n of demand you mean like commercial for +services or yeah for servic Goods + + align:start position:0% +services or yeah for servic Goods + + + align:start position:0% +services or yeah for servic Goods +business but then also I Seth mentioned + + align:start position:0% +business but then also I Seth mentioned + + + align:start position:0% +business but then also I Seth mentioned +that too that I saw a strong sense of + + align:start position:0% +that too that I saw a strong sense of + + + align:start position:0% +that too that I saw a strong sense of +unity among the people because they + + align:start position:0% +unity among the people because they + + + align:start position:0% +unity among the people because they +speak the same language because they + + align:start position:0% +speak the same language because they + + + align:start position:0% +speak the same language because they +minority majority and I think + + align:start position:0% +minority majority and I think + + + align:start position:0% +minority majority and I think +that's the same oh um they speak most + + align:start position:0% +that's the same oh um they speak most + + + align:start position:0% +that's the same oh um they speak most +most of them speak Spanish and um I + + align:start position:0% +most of them speak Spanish and um I + + + align:start position:0% +most of them speak Spanish and um I +guess it is a minority language in the + + align:start position:0% +guess it is a minority language in the + + + align:start position:0% +guess it is a minority language in the +country but in the area that's the + + align:start position:0% +country but in the area that's the + + + align:start position:0% +country but in the area that's the +majority speak + + align:start position:0% +majority speak + + + align:start position:0% +majority speak +so sense + + align:start position:0% + + + + align:start position:0% + +of + + align:start position:0% + + + + align:start position:0% + +next okay let's see + + align:start position:0% +next okay let's see + + + align:start position:0% +next okay let's see +here um + + align:start position:0% +here um + + + align:start position:0% +here um +the first I have year is that not end + + align:start position:0% +the first I have year is that not end + + + align:start position:0% +the first I have year is that not end +didn't seem to be too poor to + + align:start position:0% + + + + align:start position:0% + +me that's interesting I mean I that's + + align:start position:0% +me that's interesting I mean I that's + + + align:start position:0% +me that's interesting I mean I that's +compared + + align:start position:0% +compared + + + align:start position:0% +compared +toity Philadelphia the summer + + align:start position:0% +toity Philadelphia the summer + + + align:start position:0% +toity Philadelphia the summer +I anyway I don't know where + + align:start position:0% + + + + align:start position:0% + +that + + align:start position:0% + + + + align:start position:0% + +POS um + + align:start position:0% +POS um + + + align:start position:0% +POS um +then uh two things actually on Neo one + + align:start position:0% +then uh two things actually on Neo one + + + align:start position:0% +then uh two things actually on Neo one +of them was I was a little bit concerned + + align:start position:0% +of them was I was a little bit concerned + + + align:start position:0% +of them was I was a little bit concerned +about the financial sustainability of + + align:start position:0% +about the financial sustainability of + + + align:start position:0% +about the financial sustainability of +neon for a long period of time and I + + align:start position:0% +neon for a long period of time and I + + + align:start position:0% +neon for a long period of time and I +thought it was a little bit concerned so + + align:start position:0% +thought it was a little bit concerned so + + + align:start position:0% +thought it was a little bit concerned so +um I don't know what to put that + + align:start position:0% +um I don't know what to put that + + + align:start position:0% +um I don't know what to put that +but just some concerns I + + align:start position:0% + + + + align:start position:0% + +have + + align:start position:0% +have + + + align:start position:0% +have +um then also I had a they appear to be a + + align:start position:0% +um then also I had a they appear to be a + + + align:start position:0% +um then also I had a they appear to be a +small number of people compared to the + + align:start position:0% +small number of people compared to the + + + align:start position:0% +small number of people compared to the +size of the city I mean in said it seem + + align:start position:0% +size of the city I mean in said it seem + + + align:start position:0% +size of the city I mean in said it seem +to be to be too big and too few people + + align:start position:0% +to be to be too big and too few people + + + align:start position:0% +to be to be too big and too few people +you know so in a way you might say that + + align:start position:0% +you know so in a way you might say that + + + align:start position:0% +you know so in a way you might say that +the city's capacity was greater than you + + align:start position:0% +the city's capacity was greater than you + + + align:start position:0% +the city's capacity was greater than you +know the available resource use or + + align:start position:0% +know the available resource use or + + + align:start position:0% +know the available resource use or +whatever so + + align:start position:0% +whatever so + + + align:start position:0% +whatever so +um you are very good + + align:start position:0% +um you are very good + + + align:start position:0% +um you are very good +aty so I don't + + align:start position:0% + + + + align:start position:0% + +know then another concern I had + + align:start position:0% +know then another concern I had + + + align:start position:0% +know then another concern I had +um was I had a concern about the + + align:start position:0% +um was I had a concern about the + + + align:start position:0% +um was I had a concern about the +technical capacity of the neon staff + + align:start position:0% +technical capacity of the neon staff + + + align:start position:0% +technical capacity of the neon staff +Beyond providing Social Services I mean + + align:start position:0% +Beyond providing Social Services I mean + + + align:start position:0% +Beyond providing Social Services I mean +like I kept thinking if we were to come + + align:start position:0% +like I kept thinking if we were to come + + + align:start position:0% +like I kept thinking if we were to come +up with any other project Beyond Social + + align:start position:0% +up with any other project Beyond Social + + + align:start position:0% +up with any other project Beyond Social +Services I would it be implemented and + + align:start position:0% +Services I would it be implemented and + + + align:start position:0% +Services I would it be implemented and +in my mind it was this question about + + align:start position:0% +in my mind it was this question about + + + align:start position:0% +in my mind it was this question about +what have the people I saw and talk with + + align:start position:0% +what have the people I saw and talk with + + + align:start position:0% +what have the people I saw and talk with +you know how to keep technical + + align:start position:0% +you know how to keep technical + + + align:start position:0% +you know how to keep technical +capacity so that it's a negative + + align:start position:0% + + + + align:start position:0% + +and my last observ Vision was that I + + align:start position:0% +and my last observ Vision was that I + + + align:start position:0% +and my last observ Vision was that I +mean like um shean I think Jeff had a + + align:start position:0% +mean like um shean I think Jeff had a + + + align:start position:0% +mean like um shean I think Jeff had a +very strong opinion about bringing the B + + align:start position:0% +very strong opinion about bringing the B + + + align:start position:0% +very strong opinion about bringing the B +employees out into the community and he + + align:start position:0% +employees out into the community and he + + + align:start position:0% +employees out into the community and he +kept saying that over and over I said + + align:start position:0% +kept saying that over and over I said + + + align:start position:0% +kept saying that over and over I said +this is the plan I have you know so I I + + align:start position:0% +this is the plan I have you know so I I + + + align:start position:0% +this is the plan I have you know so I I +felt a little bit uncomfortable with + + align:start position:0% +felt a little bit uncomfortable with + + + align:start position:0% +felt a little bit uncomfortable with +that that's a positive positive oh sorry + + align:start position:0% + + + + align:start position:0% + +the first thing I it doesn't look + + align:start position:0% +the first thing I it doesn't look + + + align:start position:0% +the first thing I it doesn't look +that expected it I'll just put that as + + align:start position:0% +that expected it I'll just put that as + + + align:start position:0% +that expected it I'll just put that as +neutral because looks be + + align:start position:0% +neutral because looks be + + + align:start position:0% +neutral because looks be +deceiving and um another thing is um + + align:start position:0% +deceiving and um another thing is um + + + align:start position:0% +deceiving and um another thing is um +drugs like nobody really talk nobody + + align:start position:0% +drugs like nobody really talk nobody + + + align:start position:0% +drugs like nobody really talk nobody +that I spoke to talk directly about it + + align:start position:0% +that I spoke to talk directly about it + + + align:start position:0% +that I spoke to talk directly about it +but there's you know methodone Clinic + + align:start position:0% +but there's you know methodone Clinic + + + align:start position:0% +but there's you know methodone Clinic +there's such huge race of incarceration + + align:start position:0% +there's such huge race of incarceration + + + align:start position:0% +there's such huge race of incarceration +you can kind of tell that there's + + align:start position:0% +you can kind of tell that there's + + + align:start position:0% +you can kind of tell that there's +something with drugs going on people are + + align:start position:0% +something with drugs going on people are + + + align:start position:0% +something with drugs going on people are +talking about + + align:start position:0% + + + + align:start position:0% + +the next one is the scary Highway ever + + align:start position:0% +the next one is the scary Highway ever + + + align:start position:0% +the next one is the scary Highway ever +pass + + align:start position:0% +pass + + + align:start position:0% +pass +too that was very + + align:start position:0% +too that was very + + + align:start position:0% +too that was very +traumatized um and next one everybody + + align:start position:0% +traumatized um and next one everybody + + + align:start position:0% +traumatized um and next one everybody +knows everybody people pick up each + + align:start position:0% +knows everybody people pick up each + + + align:start position:0% +knows everybody people pick up each +other's kids that asking like people are + + align:start position:0% +other's kids that asking like people are + + + align:start position:0% +other's kids that asking like people are +just really kind of you you can tell + + align:start position:0% +just really kind of you you can tell + + + align:start position:0% +just really kind of you you can tell +when you walk in stores and everything + + align:start position:0% +when you walk in stores and everything + + + align:start position:0% +when you walk in stores and everything +everybody part of it we're walking + + align:start position:0% +everybody part of it we're walking + + + align:start position:0% +everybody part of it we're walking +around with + + align:start position:0% +around with + + + align:start position:0% +around with +Myra and also women seem to write a lot + + align:start position:0% +Myra and also women seem to write a lot + + + align:start position:0% +Myra and also women seem to write a lot +of the datto day community activities + + align:start position:0% +of the datto day community activities + + + align:start position:0% +of the datto day community activities +like just like in the shops the + + align:start position:0% +like just like in the shops the + + + align:start position:0% +like just like in the shops the +shopkeepers to be wom people on stuff + + align:start position:0% +shopkeepers to be wom people on stuff + + + align:start position:0% +shopkeepers to be wom people on stuff +like B maybe that + + align:start position:0% + + + + align:start position:0% + +could oh like women tend to run they + + align:start position:0% +could oh like women tend to run they + + + align:start position:0% +could oh like women tend to run they +just seem to be a lot of like women tend + + align:start position:0% +just seem to be a lot of like women tend + + + align:start position:0% +just seem to be a lot of like women tend +to have like a really positive strong + + align:start position:0% +to have like a really positive strong + + + align:start position:0% +to have like a really positive strong +role in the community like just walking + + align:start position:0% +role in the community like just walking + + + align:start position:0% +role in the community like just walking +around like even a lot of people that + + align:start position:0% +around like even a lot of people that + + + align:start position:0% +around like even a lot of people that +work at stores are tend to + + align:start position:0% + + + + align:start position:0% + +be the first thing that I thought would + + align:start position:0% +be the first thing that I thought would + + + align:start position:0% +be the first thing that I thought would +be important was that they seem very + + align:start position:0% +be important was that they seem very + + + align:start position:0% +be important was that they seem very +interesting what we have to say I'm + + align:start position:0% +interesting what we have to say I'm + + + align:start position:0% +interesting what we have to say I'm +going to + + align:start position:0% + + + + align:start position:0% + +put um another thing I guess maybe that + + align:start position:0% +put um another thing I guess maybe that + + + align:start position:0% +put um another thing I guess maybe that +there is some State involvement that + + align:start position:0% +there is some State involvement that + + + align:start position:0% +there is some State involvement that +they're not talking about but it seemed + + align:start position:0% +they're not talking about but it seemed + + + align:start position:0% +they're not talking about but it seemed +like they weren't really engaging with + + align:start position:0% +like they weren't really engaging with + + + align:start position:0% +like they weren't really engaging with +the state that + + align:start position:0% + + + + align:start position:0% + +seem and uh in the same way they seem to + + align:start position:0% +seem and uh in the same way they seem to + + + align:start position:0% +seem and uh in the same way they seem to +not really be connecting with the rest + + align:start position:0% +not really be connecting with the rest + + + align:start position:0% +not really be connecting with the rest +of the city either on social or + + align:start position:0% +of the city either on social or + + + align:start position:0% +of the city either on social or +political level + + align:start position:0% + + + + align:start position:0% + +negative I mean maybe it's + + align:start position:0% + + + + align:start position:0% + +Neal might want to believe people seem + + align:start position:0% +Neal might want to believe people seem + + + align:start position:0% +Neal might want to believe people seem +very interested in making the most of + + align:start position:0% +very interested in making the most of + + + align:start position:0% +very interested in making the most of +the infrastructure they're part of so + + align:start position:0% +the infrastructure they're part of so + + + align:start position:0% +the infrastructure they're part of so +meaning whatever that thing was called + + align:start position:0% +meaning whatever that thing was called + + + align:start position:0% +meaning whatever that thing was called +the the school and all those Community + + align:start position:0% +the the school and all those Community + + + align:start position:0% +the the school and all those Community +rooms but that seemed like that could be + + align:start position:0% +rooms but that seemed like that could be + + + align:start position:0% +rooms but that seemed like that could be +positive or negative because maybe + + align:start position:0% +positive or negative because maybe + + + align:start position:0% +positive or negative because maybe +that's not really the way to go so + + align:start position:0% +that's not really the way to go so + + + align:start position:0% +that's not really the way to go so +mix + + align:start position:0% +mix + + + align:start position:0% +mix +bag and uh finally I felt like they were + + align:start position:0% +bag and uh finally I felt like they were + + + align:start position:0% +bag and uh finally I felt like they were +very helpful for the future of that + + align:start position:0% + + + + align:start position:0% + +Community First I have that the staff at + + align:start position:0% +Community First I have that the staff at + + + align:start position:0% +Community First I have that the staff at +neon is very committed and knowledgeable + + align:start position:0% +neon is very committed and knowledgeable + + + align:start position:0% +neon is very committed and knowledgeable +and capable and that came out very + + align:start position:0% +and capable and that came out very + + + align:start position:0% +and capable and that came out very +positive but I meant it actually more as + + align:start position:0% +positive but I meant it actually more as + + + align:start position:0% +positive but I meant it actually more as +a mixed bag + + align:start position:0% + + + + align:start position:0% + +I mean I think I was that my first + + align:start position:0% +I mean I think I was that my first + + + align:start position:0% +I mean I think I was that my first +impression but then I after back that's + + align:start position:0% +impression but then I after back that's + + + align:start position:0% +impression but then I after back that's +can be a dangerous thing especially when + + align:start position:0% +can be a dangerous thing especially when + + + align:start position:0% +can be a dangerous thing especially when +there're our client and we working for + + align:start position:0% +there're our client and we working for + + + align:start position:0% +there're our client and we working for +them you yeah I'm trying to find what + + align:start position:0% +them you yeah I'm trying to find what + + + align:start position:0% +them you yeah I'm trying to find what +the what well just because there's a + + align:start position:0% +the what well just because there's a + + + align:start position:0% +the what well just because there's a +danger that we completely accept their + + align:start position:0% +danger that we completely accept their + + + align:start position:0% +danger that we completely accept their +perceptions of things that they give us + + align:start position:0% +perceptions of things that they give us + + + align:start position:0% +perceptions of things that they give us +only one side of isues like Jeff the B + + align:start position:0% +only one side of isues like Jeff the B + + + align:start position:0% +only one side of isues like Jeff the B +St and I think that that can be + + align:start position:0% +St and I think that that can be + + + align:start position:0% +St and I think that that can be +dangerous uh second there was a Vibrance + + align:start position:0% +dangerous uh second there was a Vibrance + + + align:start position:0% +dangerous uh second there was a Vibrance +to the school area that really be When + + align:start position:0% +to the school area that really be When + + + align:start position:0% +to the school area that really be When +the Children weren't there so it was + + align:start position:0% +the Children weren't there so it was + + + align:start position:0% +the Children weren't there so it was +easy to see it when you we got of school + + align:start position:0% +easy to see it when you we got of school + + + align:start position:0% +easy to see it when you we got of school +and there was like everyone R around but + + align:start position:0% +and there was like everyone R around but + + + align:start position:0% +and there was like everyone R around but +even when uh we were there before the + + align:start position:0% +even when uh we were there before the + + + align:start position:0% +even when uh we were there before the +the whole complex was not nearly as bad + + align:start position:0% +the whole complex was not nearly as bad + + + align:start position:0% +the whole complex was not nearly as bad +as I pictured it to be so I thought that + + align:start position:0% +as I pictured it to be so I thought that + + + align:start position:0% +as I pictured it to be so I thought that +was a good + + align:start position:0% + + + + align:start position:0% + +thing uh the change of Main Street um + + align:start position:0% +thing uh the change of Main Street um + + + align:start position:0% +thing uh the change of Main Street um +was really drastic throughout the city + + align:start position:0% +was really drastic throughout the city + + + align:start position:0% +was really drastic throughout the city +and I think that's also Mi B I think I + + align:start position:0% +and I think that's also Mi B I think I + + + align:start position:0% +and I think that's also Mi B I think I +don't think M Street needs or should + + align:start position:0% +don't think M Street needs or should + + + align:start position:0% +don't think M Street needs or should +necessarily be one continous supporter + + align:start position:0% +necessarily be one continous supporter + + + align:start position:0% +necessarily be one continous supporter +throughout the whole city you that have + + align:start position:0% +throughout the whole city you that have + + + align:start position:0% +throughout the whole city you that have +different strengths and character um but + + align:start position:0% +different strengths and character um but + + + align:start position:0% +different strengths and character um but +at the same time it was um it was not + + align:start position:0% +at the same time it was um it was not + + + align:start position:0% +at the same time it was um it was not +necessarily A thriving kind of like + + align:start position:0% +necessarily A thriving kind of like + + + align:start position:0% +necessarily A thriving kind of like +retail or commercial area in the north + + align:start position:0% + + + + align:start position:0% + +east uh there's a lot of vacant + + align:start position:0% +east uh there's a lot of vacant + + + align:start position:0% +east uh there's a lot of vacant +developable land developable developable + + align:start position:0% +developable land developable developable + + + align:start position:0% +developable land developable developable +land uh the North End also I think a + + align:start position:0% +land uh the North End also I think a + + + align:start position:0% +land uh the North End also I think a +mixed value I think at the time at + + align:start position:0% +mixed value I think at the time at + + + align:start position:0% +mixed value I think at the time at +present it's not the best in we need but + + align:start position:0% +present it's not the best in we need but + + + align:start position:0% +present it's not the best in we need but +that means a lot of opportunity for + + align:start position:0% +that means a lot of opportunity for + + + align:start position:0% +that means a lot of opportunity for +us and will describe the + + align:start position:0% +us and will describe the + + + align:start position:0% +us and will describe the +change the the Brightway Development + + align:start position:0% +change the the Brightway Development + + + align:start position:0% +change the the Brightway Development +Corporation like the change in their + + align:start position:0% +Corporation like the change in their + + + align:start position:0% +Corporation like the change in their +presence in the community and I still + + align:start position:0% +presence in the community and I still + + + align:start position:0% +presence in the community and I still +fully understand the story simply there + + align:start position:0% +fully understand the story simply there + + + align:start position:0% +fully understand the story simply there +was kind of a lot of politics around + + align:start position:0% +was kind of a lot of politics around + + + align:start position:0% +was kind of a lot of politics around +that um so but I think just the whole + + align:start position:0% +that um so but I think just the whole + + + align:start position:0% +that um so but I think just the whole +part Development Corporation presence + + align:start position:0% +part Development Corporation presence + + + align:start position:0% +part Development Corporation presence +might be a negative + + align:start position:0% + + + + align:start position:0% + +okay positive uh + + align:start position:0% +okay positive uh + + + align:start position:0% +okay positive uh +the um the midday s of community + + align:start position:0% +the um the midday s of community + + + align:start position:0% +the um the midday s of community +Vitality that we saw we got there you + + align:start position:0% +Vitality that we saw we got there you + + + align:start position:0% +Vitality that we saw we got there you +know at night was kind of calm was kind + + align:start position:0% +know at night was kind of calm was kind + + + align:start position:0% +know at night was kind of calm was kind +of calm day people walking around it was + + align:start position:0% +of calm day people walking around it was + + + align:start position:0% +of calm day people walking around it was +like very positive energy um a negative + + align:start position:0% +like very positive energy um a negative + + + align:start position:0% +like very positive energy um a negative +uh the condition of the elementary + + align:start position:0% +uh the condition of the elementary + + + align:start position:0% +uh the condition of the elementary +school and the flooding made me very + + align:start position:0% +school and the flooding made me very + + + align:start position:0% +school and the flooding made me very +nervous I wasn't really comfortable with + + align:start position:0% +nervous I wasn't really comfortable with + + + align:start position:0% +nervous I wasn't really comfortable with +sort of um I mean it's it's definitely + + align:start position:0% +sort of um I mean it's it's definitely + + + align:start position:0% +sort of um I mean it's it's definitely +an asset and they a lot with it but as + + align:start position:0% +an asset and they a lot with it but as + + + align:start position:0% +an asset and they a lot with it but as +far as how it might be used any plans we + + align:start position:0% +far as how it might be used any plans we + + + align:start position:0% +far as how it might be used any plans we +make um just something that keep in mind + + align:start position:0% +make um just something that keep in mind + + + align:start position:0% +make um just something that keep in mind +that are + + align:start position:0% +that are + + + align:start position:0% +that are +there so um what else uh mixed bag + + align:start position:0% +there so um what else uh mixed bag + + + align:start position:0% +there so um what else uh mixed bag +majority of the neon folks that um I saw + + align:start position:0% +majority of the neon folks that um I saw + + + align:start position:0% +majority of the neon folks that um I saw +I interacted with were women which I + + align:start position:0% +I interacted with were women which I + + + align:start position:0% +I interacted with were women which I +think you know are self- importantly is + + align:start position:0% +think you know are self- importantly is + + + align:start position:0% +think you know are self- importantly is +great but at the same time you know it's + + align:start position:0% +great but at the same time you know it's + + + align:start position:0% +great but at the same time you know it's +not just so something + + align:start position:0% +not just so something + + + align:start position:0% +not just so something +that positive strength of all the + + align:start position:0% +that positive strength of all the + + + align:start position:0% +that positive strength of all the +relationships that I saw familial + + align:start position:0% +relationships that I saw familial + + + align:start position:0% +relationships that I saw familial +professional and general community and a + + align:start position:0% +professional and general community and a + + + align:start position:0% +professional and general community and a +negative last one the palpable well + + align:start position:0% +negative last one the palpable well + + + align:start position:0% +negative last one the palpable well +maybe mix bag um the difference in the + + align:start position:0% +maybe mix bag um the difference in the + + + align:start position:0% +maybe mix bag um the difference in the +feel between the Brightwood and the + + align:start position:0% +feel between the Brightwood and the + + + align:start position:0% +feel between the Brightwood and the +memorial Square size um and as we try to + + align:start position:0% +memorial Square size um and as we try to + + + align:start position:0% +memorial Square size um and as we try to +figure out what to do you know it's + + align:start position:0% +figure out what to do you know it's + + + align:start position:0% +figure out what to do you know it's +possible that we decide to + + align:start position:0% +possible that we decide to + + + align:start position:0% +possible that we decide to +have ideas things that will maintain + + align:start position:0% +have ideas things that will maintain + + + align:start position:0% +have ideas things that will maintain +that difference because it's something + + align:start position:0% +that difference because it's something + + + align:start position:0% +that difference because it's something +that we really can tackle or I don't + + align:start position:0% +that we really can tackle or I don't + + + align:start position:0% +that we really can tackle or I don't +know it could be an + + align:start position:0% + + + + align:start position:0% + +as go + + align:start position:0% + + + + align:start position:0% + +ahead + + align:start position:0% +ahead + + + align:start position:0% +ahead +um I have lots of vacant buildings and + + align:start position:0% +um I have lots of vacant buildings and + + + align:start position:0% +um I have lots of vacant buildings and +lots I'm going to put that as a negative + + align:start position:0% +lots I'm going to put that as a negative + + + align:start position:0% +lots I'm going to put that as a negative +although John classified it as a mixed + + align:start position:0% +although John classified it as a mixed + + + align:start position:0% +although John classified it as a mixed +bag but think now it's kind + + align:start position:0% + + + + align:start position:0% + +um kind of used a fancy planning word + + align:start position:0% +um kind of used a fancy planning word + + + align:start position:0% +um kind of used a fancy planning word +but I uh I call the dominance of + + align:start position:0% +but I uh I call the dominance of + + + align:start position:0% +but I uh I call the dominance of +automobility between neighborhoods so + + align:start position:0% +automobility between neighborhoods so + + + align:start position:0% +automobility between neighborhoods so +that scary overcat pets um which is the + + align:start position:0% +that scary overcat pets um which is the + + + align:start position:0% +that scary overcat pets um which is the +negative in my you know my own + + align:start position:0% +negative in my you know my own + + + align:start position:0% +negative in my you know my own +perspective + + align:start position:0% +perspective + + + align:start position:0% +perspective +um I have a Bay State Suburban campus + + align:start position:0% +um I have a Bay State Suburban campus + + + align:start position:0% +um I have a Bay State Suburban campus +versus the neighborhood's Urban + + align:start position:0% +versus the neighborhood's Urban + + + align:start position:0% +versus the neighborhood's Urban +grid which + + align:start position:0% + + + + align:start position:0% + +but it's just kind of a disconnect and + + align:start position:0% +but it's just kind of a disconnect and + + + align:start position:0% +but it's just kind of a disconnect and +then kind of similar I I felt similarly + + align:start position:0% +then kind of similar I I felt similarly + + + align:start position:0% +then kind of similar I I felt similarly +to an did about the neighbor the + + align:start position:0% +to an did about the neighbor the + + + align:start position:0% +to an did about the neighbor the +different neighborhoods as well um the + + align:start position:0% +different neighborhoods as well um the + + + align:start position:0% +different neighborhoods as well um the +positive is the deep roots of neon in + + align:start position:0% +positive is the deep roots of neon in + + + align:start position:0% +positive is the deep roots of neon in +the + + align:start position:0% +the + + + align:start position:0% +the +neighborhood and then my final one is uh + + align:start position:0% +neighborhood and then my final one is uh + + + align:start position:0% +neighborhood and then my final one is uh +which I'm going to put as a mixed bag is + + align:start position:0% +which I'm going to put as a mixed bag is + + + align:start position:0% +which I'm going to put as a mixed bag is +the resilience of the underground + + align:start position:0% +the resilience of the underground + + + align:start position:0% +the resilience of the underground +school I think there's something just + + align:start position:0% +school I think there's something just + + + align:start position:0% +school I think there's something just +weird about having a school underground + + align:start position:0% +weird about having a school underground + + + align:start position:0% +weird about having a school underground +um and that it's flooded yet um people + + align:start position:0% +um and that it's flooded yet um people + + + align:start position:0% +um and that it's flooded yet um people +are committed to it um but it also kind + + align:start position:0% +are committed to it um but it also kind + + + align:start position:0% +are committed to it um but it also kind +of buries Vitality underground in a way + + align:start position:0% +of buries Vitality underground in a way + + + align:start position:0% +of buries Vitality underground in a way +um but that's something I think we we + + align:start position:0% +um but that's something I think we we + + + align:start position:0% +um but that's something I think we we +need to discuss and + + align:start position:0% +need to discuss and + + + align:start position:0% +need to discuss and +Tackle so M are kind of experiences I + + align:start position:0% +Tackle so M are kind of experiences I + + + align:start position:0% +Tackle so M are kind of experiences I +been there's so many so many times um + + align:start position:0% +been there's so many so many times um + + + align:start position:0% +been there's so many so many times um +but actually one new one for me was when + + align:start position:0% +but actually one new one for me was when + + + align:start position:0% +but actually one new one for me was when +we left the herena school and walked up + + align:start position:0% +we left the herena school and walked up + + + align:start position:0% +we left the herena school and walked up +Main Street under the highway into the + + align:start position:0% +Main Street under the highway into the + + + align:start position:0% +Main Street under the highway into the +complex area where state is and just the + + align:start position:0% +complex area where state is and just the + + + align:start position:0% +complex area where state is and just the +difference of walking from one side of + + align:start position:0% +difference of walking from one side of + + + align:start position:0% +difference of walking from one side of +that underpass overpass to the other + + align:start position:0% +that underpass overpass to the other + + + align:start position:0% +that underpass overpass to the other +side uh and what was there and I I it's + + align:start position:0% +side uh and what was there and I I it's + + + align:start position:0% +side uh and what was there and I I it's +for me it's a negative because it's + + align:start position:0% +for me it's a negative because it's + + + align:start position:0% +for me it's a negative because it's +really about things just not + + align:start position:0% +really about things just not + + + align:start position:0% +really about things just not +connecting + + align:start position:0% +connecting + + + align:start position:0% +connecting +uh this is just always the truth it's + + align:start position:0% +uh this is just always the truth it's + + + align:start position:0% +uh this is just always the truth it's +really the kind of warmth with which + + align:start position:0% +really the kind of warmth with which + + + align:start position:0% +really the kind of warmth with which +people greet everyone and us and folks + + align:start position:0% +people greet everyone and us and folks + + + align:start position:0% +people greet everyone and us and folks +that they don't + + align:start position:0% +that they don't + + + align:start position:0% +that they don't +know uh the scary Bridge experience of + + align:start position:0% +know uh the scary Bridge experience of + + + align:start position:0% +know uh the scary Bridge experience of +walking across from Memorial Square to + + align:start position:0% +walking across from Memorial Square to + + + align:start position:0% +walking across from Memorial Square to +Brightwood the top of the highway you + + align:start position:0% +Brightwood the top of the highway you + + + align:start position:0% +Brightwood the top of the highway you +know in single file like the Little D + + align:start position:0% +know in single file like the Little D + + + align:start position:0% +know in single file like the Little D +ducklings and uh that was very scary um + + align:start position:0% +ducklings and uh that was very scary um + + + align:start position:0% +ducklings and uh that was very scary um +I also thought the lack of variety in + + align:start position:0% +I also thought the lack of variety in + + + align:start position:0% +I also thought the lack of variety in +the kinds of small businesses they were + + align:start position:0% +the kinds of small businesses they were + + + align:start position:0% +the kinds of small businesses they were +either grocery stores or grocery stores + + align:start position:0% +either grocery stores or grocery stores + + + align:start position:0% +either grocery stores or grocery stores +or restaurants and that was basically it + + align:start position:0% +or restaurants and that was basically it + + + align:start position:0% +or restaurants and that was basically it +and that didn't seem very viable uh to + + align:start position:0% +and that didn't seem very viable uh to + + + align:start position:0% +and that didn't seem very viable uh to +me I think that's + + align:start position:0% +me I think that's + + + align:start position:0% +me I think that's +fire oh this one is oh and the number of + + align:start position:0% +fire oh this one is oh and the number of + + + align:start position:0% +fire oh this one is oh and the number of +board I was actually very surprised by + + align:start position:0% +board I was actually very surprised by + + + align:start position:0% +board I was actually very surprised by +but the number of boarded up houses from + + align:start position:0% +but the number of boarded up houses from + + + align:start position:0% +but the number of boarded up houses from +fire there were actually + + align:start position:0% +fire there were actually + + + align:start position:0% +fire there were actually +that was actually quite a change from + + align:start position:0% +that was actually quite a change from + + + align:start position:0% +that was actually quite a change from +the last time I had walked through the + + align:start position:0% +the last time I had walked through the + + + align:start position:0% +the last time I had walked through the +neighborhood + + align:start position:0% +neighborhood + + + align:start position:0% +neighborhood +so uh it was last + + align:start position:0% +so uh it was last + + + align:start position:0% +so uh it was last +spring actually was it last spring or + + align:start position:0% +spring actually was it last spring or + + + align:start position:0% +spring actually was it last spring or +well it was in January so that's not + + align:start position:0% +well it was in January so that's not + + + align:start position:0% +well it was in January so that's not +really spring that's winter isn't it + + align:start position:0% +really spring that's winter isn't it + + + align:start position:0% +really spring that's winter isn't it +yeah spring semester months + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +okay how much you feel + + align:start position:0% + + + + align:start position:0% + +would it seemed double at least you know + + align:start position:0% +would it seemed double at least you know + + + align:start position:0% +would it seemed double at least you know +just was it in one area more than yeah + + align:start position:0% +just was it in one area more than yeah + + + align:start position:0% +just was it in one area more than yeah +in the in the square + + align:start position:0% +in the in the square + + + align:start position:0% +in the in the square +area um I thought that the scale of the + + align:start position:0% +area um I thought that the scale of the + + + align:start position:0% +area um I thought that the scale of the +vacant industrial buildings um you know + + align:start position:0% +vacant industrial buildings um you know + + + align:start position:0% +vacant industrial buildings um you know +they + + align:start position:0% +they + + + align:start position:0% +they +were quite large um some in pretty bad + + align:start position:0% +were quite large um some in pretty bad + + + align:start position:0% +were quite large um some in pretty bad +shape you know clearly some serious + + align:start position:0% +shape you know clearly some serious + + + align:start position:0% +shape you know clearly some serious +Brownfield issues so that that was going + + align:start position:0% +Brownfield issues so that that was going + + + align:start position:0% +Brownfield issues so that that was going +to + + align:start position:0% +to + + + align:start position:0% +to +be and I thought it + + align:start position:0% +be and I thought it + + + align:start position:0% +be and I thought it +um while they weren't at the center of + + align:start position:0% +um while they weren't at the center of + + + align:start position:0% +um while they weren't at the center of +the neighborhood they certainly you know + + align:start position:0% +the neighborhood they certainly you know + + + align:start position:0% +the neighborhood they certainly you know +had a strong a strong impact um and then + + align:start position:0% +had a strong a strong impact um and then + + + align:start position:0% +had a strong a strong impact um and then +another negative The Limited knowledge + + align:start position:0% +another negative The Limited knowledge + + + align:start position:0% +another negative The Limited knowledge +of businesses and residents at least + + align:start position:0% +of businesses and residents at least + + + align:start position:0% +of businesses and residents at least +among the Outreach worker and our tour + + align:start position:0% +among the Outreach worker and our tour + + + align:start position:0% +among the Outreach worker and our tour +um I was I was very surprised how little + + align:start position:0% +um I was I was very surprised how little + + + align:start position:0% +um I was I was very surprised how little +he seemed to know about you know who + + align:start position:0% +he seemed to know about you know who + + + align:start position:0% +he seemed to know about you know who +were these businesses who did they + + align:start position:0% +were these businesses who did they + + + align:start position:0% +were these businesses who did they +employ where did people work um and I I + + align:start position:0% +employ where did people work um and I I + + + align:start position:0% +employ where did people work um and I I +sort of fear it's kind of emblematic of + + align:start position:0% +sort of fear it's kind of emblematic of + + + align:start position:0% +sort of fear it's kind of emblematic of +the lack of relationships between some + + align:start position:0% +the lack of relationships between some + + + align:start position:0% +the lack of relationships between some +of the organizations and The Business + + align:start position:0% +of the organizations and The Business + + + align:start position:0% +of the organizations and The Business +Community although I don't really know + + align:start position:0% +Community although I don't really know + + + align:start position:0% +Community although I don't really know +that um I think on a positive side um I + + align:start position:0% +that um I think on a positive side um I + + + align:start position:0% +that um I think on a positive side um I +I was actually quite surprised by the + + align:start position:0% +I was actually quite surprised by the + + + align:start position:0% +I was actually quite surprised by the +level and diversity of economic activity + + align:start position:0% +level and diversity of economic activity + + + align:start position:0% +level and diversity of economic activity +in the neighborhood when you really add + + align:start position:0% +in the neighborhood when you really add + + + align:start position:0% +in the neighborhood when you really add +everything up with with base state with + + align:start position:0% +everything up with with base state with + + + align:start position:0% +everything up with with base state with +the small scale retail there's even some + + align:start position:0% +the small scale retail there's even some + + + align:start position:0% +the small scale retail there's even some +Distributors there you have all those + + align:start position:0% +Distributors there you have all those + + + align:start position:0% +Distributors there you have all those +Transportation businesses and then you + + align:start position:0% +Transportation businesses and then you + + + align:start position:0% +Transportation businesses and then you +have industry you know um um um it was + + align:start position:0% +have industry you know um um um it was + + + align:start position:0% +have industry you know um um um it was +it was quite diverse and and probably if + + align:start position:0% +it was quite diverse and and probably if + + + align:start position:0% +it was quite diverse and and probably if +you counted up all those jobs you know + + align:start position:0% +you counted up all those jobs you know + + + align:start position:0% +you counted up all those jobs you know +there's there's probably um you know a + + align:start position:0% +there's there's probably um you know a + + + align:start position:0% +there's there's probably um you know a +number of jobs that may equal or exceed + + align:start position:0% +number of jobs that may equal or exceed + + + align:start position:0% +number of jobs that may equal or exceed +you know the workforce that's in the + + align:start position:0% +you know the workforce that's in the + + + align:start position:0% +you know the workforce that's in the +neighborhood um I think probably the + + align:start position:0% +neighborhood um I think probably the + + + align:start position:0% +neighborhood um I think probably the +thing that impressed me the most was the + + align:start position:0% +thing that impressed me the most was the + + + align:start position:0% +thing that impressed me the most was the +accomplishments of neon and the + + align:start position:0% +accomplishments of neon and the + + + align:start position:0% +accomplishments of neon and the +Brightwood Health Center um and bringing + + align:start position:0% +Brightwood Health Center um and bringing + + + align:start position:0% +Brightwood Health Center um and bringing +back about some of the systematic change + + align:start position:0% +back about some of the systematic change + + + align:start position:0% +back about some of the systematic change +in the health care bringing you know + + align:start position:0% +in the health care bringing you know + + + align:start position:0% +in the health care bringing you know +getting the UN insurance rate cut in + + align:start position:0% +getting the UN insurance rate cut in + + + align:start position:0% +getting the UN insurance rate cut in +half um you know changing the model in + + align:start position:0% +half um you know changing the model in + + + align:start position:0% +half um you know changing the model in +which Healthcare was delivered getting + + align:start position:0% +which Healthcare was delivered getting + + + align:start position:0% +which Healthcare was delivered getting +better health care for the prison + + align:start position:0% +better health care for the prison + + + align:start position:0% +better health care for the prison +population that sure could really shows + + align:start position:0% +population that sure could really shows + + + align:start position:0% +population that sure could really shows +some some creative thinking and some + + align:start position:0% +some some creative thinking and some + + + align:start position:0% +some some creative thinking and some +significant capacity to get things done + + align:start position:0% +significant capacity to get things done + + + align:start position:0% +significant capacity to get things done +um and this I'll say is sort of neutral + + align:start position:0% +um and this I'll say is sort of neutral + + + align:start position:0% +um and this I'll say is sort of neutral +that the contrast between the two parts + + align:start position:0% +that the contrast between the two parts + + + align:start position:0% +that the contrast between the two parts +of the neighborhood I mean it was it was + + align:start position:0% +of the neighborhood I mean it was it was + + + align:start position:0% +of the neighborhood I mean it was it was +even after reading about it it did they + + align:start position:0% +even after reading about it it did they + + + align:start position:0% +even after reading about it it did they +really felt with two different worlds um + + align:start position:0% +really felt with two different worlds um + + + align:start position:0% +really felt with two different worlds um +the sort of very maybe it was because of + + align:start position:0% +the sort of very maybe it was because of + + + align:start position:0% +the sort of very maybe it was because of +of the time of day but this's very very + + align:start position:0% +of the time of day but this's very very + + + align:start position:0% +of the time of day but this's very very +quiet residential neighborhood with not + + align:start position:0% +quiet residential neighborhood with not + + + align:start position:0% +quiet residential neighborhood with not +many people out not much traffic and + + align:start position:0% +many people out not much traffic and + + + align:start position:0% +many people out not much traffic and +then Memorial Square you know with all + + align:start position:0% +then Memorial Square you know with all + + + align:start position:0% +then Memorial Square you know with all +that traffic and activity and everything + + align:start position:0% + + + + align:start position:0% + +so overall thoughts Impressions after + + align:start position:0% +so overall thoughts Impressions after + + + align:start position:0% +so overall thoughts Impressions after +kind of hearing everyone report out you + + align:start position:0% + + + + align:start position:0% + +commonalities what's the story you would + + align:start position:0% +commonalities what's the story you would + + + align:start position:0% +commonalities what's the story you would +take from what you just + + align:start position:0% + + + + align:start position:0% + +heard I thought a lot of the positive + + align:start position:0% +heard I thought a lot of the positive + + + align:start position:0% +heard I thought a lot of the positive +comments have something to do with the + + align:start position:0% +comments have something to do with the + + + align:start position:0% +comments have something to do with the +human asset kind like a lot of people + + align:start position:0% +human asset kind like a lot of people + + + align:start position:0% +human asset kind like a lot of people +made positive observations about the + + align:start position:0% +made positive observations about the + + + align:start position:0% +made positive observations about the +human Network that existed in the area + + align:start position:0% +human Network that existed in the area + + + align:start position:0% +human Network that existed in the area +while a lot of the negative comments had + + align:start position:0% +while a lot of the negative comments had + + + align:start position:0% +while a lot of the negative comments had +more to do with the physical + + align:start position:0% +more to do with the physical + + + align:start position:0% +more to do with the physical +infrastructures or I don't know if + + align:start position:0% +infrastructures or I don't know if + + + align:start position:0% +infrastructures or I don't know if +economic activities are part of the + + align:start position:0% +economic activities are part of the + + + align:start position:0% +economic activities are part of the +physical infrastructures but um how the + + align:start position:0% +physical infrastructures but um how the + + + align:start position:0% +physical infrastructures but um how the +physical setting was + + align:start position:0% + + + + align:start position:0% + +present some people think about that as + + align:start position:0% +present some people think about that as + + + align:start position:0% +present some people think about that as +an + + align:start position:0% +an + + + align:start position:0% +an +observation that's good + + align:start position:0% + + + + align:start position:0% + +anything else + + align:start position:0% + + + + align:start position:0% + +pleas let me ask us um last week we + + align:start position:0% +pleas let me ask us um last week we + + + align:start position:0% +pleas let me ask us um last week we +talked a little about um how people are + + align:start position:0% +talked a little about um how people are + + + align:start position:0% +talked a little about um how people are +feeling about the sort of charge we've + + align:start position:0% +feeling about the sort of charge we've + + + align:start position:0% +feeling about the sort of charge we've +been given by Neon before they went out + + align:start position:0% +been given by Neon before they went out + + + align:start position:0% +been given by Neon before they went out +there and I'm curious now that you've + + align:start position:0% +there and I'm curious now that you've + + + align:start position:0% +there and I'm curious now that you've +been out in the neighborhood um and have + + align:start position:0% +been out in the neighborhood um and have + + + align:start position:0% +been out in the neighborhood um and have +you know have actually seen it and met + + align:start position:0% +you know have actually seen it and met + + + align:start position:0% +you know have actually seen it and met +the people people and have you know a + + align:start position:0% +the people people and have you know a + + + align:start position:0% +the people people and have you know a +richer sense of of um you know the the + + align:start position:0% +richer sense of of um you know the the + + + align:start position:0% +richer sense of of um you know the the +client and the community how how do that + + align:start position:0% +client and the community how how do that + + + align:start position:0% +client and the community how how do that +changed your thinking about about the + + align:start position:0% +changed your thinking about about the + + + align:start position:0% +changed your thinking about about the +project and your sort of optimism or + + align:start position:0% +project and your sort of optimism or + + + align:start position:0% +project and your sort of optimism or +pessimism about + + align:start position:0% + + + + align:start position:0% + +it I was the only one last week who said + + align:start position:0% +it I was the only one last week who said + + + align:start position:0% +it I was the only one last week who said +anything pessimistic or explicitly + + align:start position:0% +anything pessimistic or explicitly + + + align:start position:0% +anything pessimistic or explicitly +pessimist but I felt a lot more positive + + align:start position:0% +pessimist but I felt a lot more positive + + + align:start position:0% +pessimist but I felt a lot more positive +after having been there I I was really I + + align:start position:0% +after having been there I I was really I + + + align:start position:0% +after having been there I I was really I +guess kind of skeptical about what they + + align:start position:0% +guess kind of skeptical about what they + + + align:start position:0% +guess kind of skeptical about what they +expected from us in terms of whether + + align:start position:0% +expected from us in terms of whether + + + align:start position:0% +expected from us in terms of whether +they were really excited about being + + align:start position:0% +they were really excited about being + + + align:start position:0% +they were really excited about being +involved and like I gu didn't really + + align:start position:0% +involved and like I gu didn't really + + + align:start position:0% +involved and like I gu didn't really +realize that they had saw us out that + + align:start position:0% +realize that they had saw us out that + + + align:start position:0% +realize that they had saw us out that +there was kind of long relationship + + align:start position:0% +there was kind of long relationship + + + align:start position:0% +there was kind of long relationship +so I don't know I think that um just + + align:start position:0% +so I don't know I think that um just + + + align:start position:0% +so I don't know I think that um just +they're being excited about working with + + align:start position:0% +they're being excited about working with + + + align:start position:0% +they're being excited about working with +us it makes me excited about working + + align:start position:0% +us it makes me excited about working + + + align:start position:0% +us it makes me excited about working +with + + align:start position:0% +with + + + align:start position:0% +with +them um I'm still really positive but + + align:start position:0% +them um I'm still really positive but + + + align:start position:0% +them um I'm still really positive but +especially with all these colorful posts + + align:start position:0% +especially with all these colorful posts + + + align:start position:0% +especially with all these colorful posts +up no idea how we will accomplish + + align:start position:0% +up no idea how we will accomplish + + + align:start position:0% +up no idea how we will accomplish +anything by the end of this + + align:start position:0% + + + + align:start position:0% + +St I ear as well I think that I felt + + align:start position:0% +St I ear as well I think that I felt + + + align:start position:0% +St I ear as well I think that I felt +very and I think that I I know I felt + + align:start position:0% +very and I think that I I know I felt + + + align:start position:0% +very and I think that I I know I felt +very um strongly about all the potential + + align:start position:0% +very um strongly about all the potential + + + align:start position:0% +very um strongly about all the potential +for what we as a group could + + align:start position:0% +for what we as a group could + + + align:start position:0% +for what we as a group could +do you know crafting and economic + + align:start position:0% +do you know crafting and economic + + + align:start position:0% +do you know crafting and economic +development plan once we got there + + align:start position:0% +development plan once we got there + + + align:start position:0% +development plan once we got there +walked around with a sense of what sort + + align:start position:0% +walked around with a sense of what sort + + + align:start position:0% +walked around with a sense of what sort +of of facilities and and business exist + + align:start position:0% +of of facilities and and business exist + + + align:start position:0% +of of facilities and and business exist +in the + + align:start position:0% +in the + + + align:start position:0% +in the +community but then every time a neon + + align:start position:0% +community but then every time a neon + + + align:start position:0% +community but then every time a neon +worker would talk about any of those + + align:start position:0% +worker would talk about any of those + + + align:start position:0% +worker would talk about any of those +businesses or facilities or talk about + + align:start position:0% +businesses or facilities or talk about + + + align:start position:0% +businesses or facilities or talk about +their ideas what was you know what they + + align:start position:0% +their ideas what was you know what they + + + align:start position:0% +their ideas what was you know what they +com to consisted of it was quite + + align:start position:0% +com to consisted of it was quite + + + align:start position:0% +com to consisted of it was quite +worrisome because it seems almost like + + align:start position:0% +worrisome because it seems almost like + + + align:start position:0% +worrisome because it seems almost like +one of our biggest obstacles is going to + + align:start position:0% +one of our biggest obstacles is going to + + + align:start position:0% +one of our biggest obstacles is going to +be our + + align:start position:0% +be our + + + align:start position:0% +be our +client and reminds me of this at the + + align:start position:0% +client and reminds me of this at the + + + align:start position:0% +client and reminds me of this at the +time would seemed like a really weird + + align:start position:0% +time would seemed like a really weird + + + align:start position:0% +time would seemed like a really weird +question that our Gateway take home fin + + align:start position:0% +question that our Gateway take home fin + + + align:start position:0% +question that our Gateway take home fin +which is like what do you do if the + + align:start position:0% +which is like what do you do if the + + + align:start position:0% +which is like what do you do if the +community group you work for doesn't + + align:start position:0% +community group you work for doesn't + + + align:start position:0% +community group you work for doesn't +want you to do what you think you should + + align:start position:0% +want you to do what you think you should + + + align:start position:0% +want you to do what you think you should +be doing in their best + + align:start position:0% +be doing in their best + + + align:start position:0% +be doing in their best +interest like look up the code of ethics + + align:start position:0% +interest like look up the code of ethics + + + align:start position:0% +interest like look up the code of ethics +to answer that question as well the time + + align:start position:0% + + + + align:start position:0% + +I actually I would I mean I I don't want + + align:start position:0% +I actually I would I mean I I don't want + + + align:start position:0% +I actually I would I mean I I don't want +to dwell on one topic too much but I I + + align:start position:0% +to dwell on one topic too much but I I + + + align:start position:0% +to dwell on one topic too much but I I +just there was an anecdote I was + + align:start position:0% +just there was an anecdote I was + + + align:start position:0% +just there was an anecdote I was +thinking of that do tells what both Shan + + align:start position:0% +thinking of that do tells what both Shan + + + align:start position:0% +thinking of that do tells what both Shan +and Anna were saying which is that + + align:start position:0% +and Anna were saying which is that + + + align:start position:0% +and Anna were saying which is that +uh at lunch uh the kind of questions we + + align:start position:0% +uh at lunch uh the kind of questions we + + + align:start position:0% +uh at lunch uh the kind of questions we +were getting were making me wonder you + + align:start position:0% +were getting were making me wonder you + + + align:start position:0% +were getting were making me wonder you +know how free we were to give any plan + + align:start position:0% +know how free we were to give any plan + + + align:start position:0% +know how free we were to give any plan +that we felt appropriate or I mean + + align:start position:0% +that we felt appropriate or I mean + + + align:start position:0% +that we felt appropriate or I mean +granted we're probably free to say + + align:start position:0% +granted we're probably free to say + + + align:start position:0% +granted we're probably free to say +anything but it made me wonder how + + align:start position:0% +anything but it made me wonder how + + + align:start position:0% +anything but it made me wonder how +receptive um the clients would be to + + align:start position:0% +receptive um the clients would be to + + + align:start position:0% +receptive um the clients would be to +anything you know cuz we sat down and it + + align:start position:0% +anything you know cuz we sat down and it + + + align:start position:0% +anything you know cuz we sat down and it +seemed like the first question out of + + align:start position:0% +seemed like the first question out of + + + align:start position:0% +seemed like the first question out of +first thing out of anyone's mouth was so + + align:start position:0% +first thing out of anyone's mouth was so + + + align:start position:0% +first thing out of anyone's mouth was so +what do we do about all the vacant + + align:start position:0% +what do we do about all the vacant + + + align:start position:0% +what do we do about all the vacant +houses here and um so + + align:start position:0% +houses here and um so + + + align:start position:0% +houses here and um so +I'm and I'm not and that just + + align:start position:0% +I'm and I'm not and that just + + + align:start position:0% +I'm and I'm not and that just +immediately was seemed to narrow the + + align:start position:0% +immediately was seemed to narrow the + + + align:start position:0% +immediately was seemed to narrow the +whole discourse that we were + + align:start position:0% +whole discourse that we were + + + align:start position:0% +whole discourse that we were +participating in about Economic + + align:start position:0% +participating in about Economic + + + align:start position:0% +participating in about Economic +Development and our project there and + + align:start position:0% +Development and our project there and + + + align:start position:0% +Development and our project there and +then there were a series of other very + + align:start position:0% +then there were a series of other very + + + align:start position:0% +then there were a series of other very +specific questions so I'm uncertain as + + align:start position:0% +specific questions so I'm uncertain as + + + align:start position:0% +specific questions so I'm uncertain as +to whether or not uh even though there's + + align:start position:0% +to whether or not uh even though there's + + + align:start position:0% +to whether or not uh even though there's +a lot of community capacity I think to + + align:start position:0% +a lot of community capacity I think to + + + align:start position:0% +a lot of community capacity I think to +do Grassroots and do good + + align:start position:0% +do Grassroots and do good + + + align:start position:0% +do Grassroots and do good +work I just wonder + + align:start position:0% +work I just wonder + + + align:start position:0% +work I just wonder +if there is a trust or a level of + + align:start position:0% +if there is a trust or a level of + + + align:start position:0% +if there is a trust or a level of +openness + + align:start position:0% +openness + + + align:start position:0% +openness +to for the partners to want to really + + align:start position:0% +to for the partners to want to really + + + align:start position:0% +to for the partners to want to really +act on plans that we a variety of plans + + align:start position:0% +act on plans that we a variety of plans + + + align:start position:0% +act on plans that we a variety of plans +that we might potentially provide + + align:start position:0% + + + + align:start position:0% + +them I didn't have that negative + + align:start position:0% +them I didn't have that negative + + + align:start position:0% +them I didn't have that negative +impression about what we could do given + + align:start position:0% +impression about what we could do given + + + align:start position:0% +impression about what we could do given +like that they have defin sense that you + + align:start position:0% +like that they have defin sense that you + + + align:start position:0% +like that they have defin sense that you +know like getting Bas employees into + + align:start position:0% +know like getting Bas employees into + + + align:start position:0% +know like getting Bas employees into +town Los and housing and all that but I + + align:start position:0% +town Los and housing and all that but I + + + align:start position:0% +town Los and housing and all that but I +don't know I got I I I feel like we I + + align:start position:0% +don't know I got I I I feel like we I + + + align:start position:0% +don't know I got I I I feel like we I +think that we can benefit from the prior + + align:start position:0% +think that we can benefit from the prior + + + align:start position:0% +think that we can benefit from the prior +experiences with students because they + + align:start position:0% +experiences with students because they + + + align:start position:0% +experiences with students because they +seem at least s like really pleased with + + align:start position:0% +seem at least s like really pleased with + + + align:start position:0% +seem at least s like really pleased with +the word that they got and I mean I feel + + align:start position:0% +the word that they got and I mean I feel + + + align:start position:0% +the word that they got and I mean I feel +confident us that we can drive an agenda + + align:start position:0% +confident us that we can drive an agenda + + + align:start position:0% +confident us that we can drive an agenda +we think that there's a different one + + align:start position:0% +we think that there's a different one + + + align:start position:0% +we think that there's a different one +than there out there um I don't I mean I + + align:start position:0% +than there out there um I don't I mean I + + + align:start position:0% +than there out there um I don't I mean I +think I was really impressed with them I + + align:start position:0% +think I was really impressed with them I + + + align:start position:0% +think I was really impressed with them I +didn't get I didn't hear Jeff as much + + align:start position:0% +didn't get I didn't hear Jeff as much + + + align:start position:0% +didn't get I didn't hear Jeff as much +people because we came in late to the + + align:start position:0% +people because we came in late to the + + + align:start position:0% +people because we came in late to the +lunch um but yeah there's this dominant + + align:start position:0% +lunch um but yeah there's this dominant + + + align:start position:0% +lunch um but yeah there's this dominant +personality aspect but I I don't feel + + align:start position:0% +personality aspect but I I don't feel + + + align:start position:0% +personality aspect but I I don't feel +like just cuz there there are find that + + align:start position:0% +like just cuz there there are find that + + + align:start position:0% +like just cuz there there are find that +we can't at them and kind of for we + + align:start position:0% +we can't at them and kind of for we + + + align:start position:0% +we can't at them and kind of for we +think is + + align:start position:0% + + + + align:start position:0% + +important so so listening to this I'm + + align:start position:0% +important so so listening to this I'm + + + align:start position:0% +important so so listening to this I'm +I'm curious if if um if People's + + align:start position:0% +I'm curious if if um if People's + + + align:start position:0% +I'm curious if if um if People's +thinking about what what the nature of + + align:start position:0% +thinking about what what the nature of + + + align:start position:0% +thinking about what what the nature of +your work + + align:start position:0% +your work + + + align:start position:0% +your work +is at least over the next few weeks is + + align:start position:0% +is at least over the next few weeks is + + + align:start position:0% +is at least over the next few weeks is +different now than it might have been + + align:start position:0% +different now than it might have been + + + align:start position:0% +different now than it might have been +last week are there things that are seem + + align:start position:0% +last week are there things that are seem + + + align:start position:0% +last week are there things that are seem +to be more of a priority for us in how + + align:start position:0% +to be more of a priority for us in how + + + align:start position:0% +to be more of a priority for us in how +we tackle this based upon either what + + align:start position:0% +we tackle this based upon either what + + + align:start position:0% +we tackle this based upon either what +you saw there or or some of the you know + + align:start position:0% +you saw there or or some of the you know + + + align:start position:0% +you saw there or or some of the you know +um client relationship issues people + + align:start position:0% +um client relationship issues people + + + align:start position:0% +um client relationship issues people +have talked about anything say wow you + + align:start position:0% +have talked about anything say wow you + + + align:start position:0% +have talked about anything say wow you +know this I wasn't really thinking that + + align:start position:0% +know this I wasn't really thinking that + + + align:start position:0% +know this I wasn't really thinking that +we had to do this but we we better make + + align:start position:0% +we had to do this but we we better make + + + align:start position:0% +we had to do this but we we better make +sure we understand this so we better + + align:start position:0% +sure we understand this so we better + + + align:start position:0% +sure we understand this so we better +make sure we learn about this to any any + + align:start position:0% +make sure we learn about this to any any + + + align:start position:0% +make sure we learn about this to any any +sort of epiphanies like like that happen + + align:start position:0% +sort of epiphanies like like that happen + + + align:start position:0% +sort of epiphanies like like that happen +or any reflection lead you to think + + align:start position:0% +or any reflection lead you to think + + + align:start position:0% +or any reflection lead you to think +something's more important than + + align:start position:0% +something's more important than + + + align:start position:0% +something's more important than +something else and and what we tackle or + + align:start position:0% +something else and and what we tackle or + + + align:start position:0% +something else and and what we tackle or +how we think about the + + align:start position:0% + + + + align:start position:0% + +work I don't think this is necess + + align:start position:0% +work I don't think this is necess + + + align:start position:0% +work I don't think this is necess +specific to this project but I think + + align:start position:0% +specific to this project but I think + + + align:start position:0% +specific to this project but I think +it's just real important that we + + align:start position:0% +it's just real important that we + + + align:start position:0% +it's just real important that we +have as soon as possible we have some + + align:start position:0% +have as soon as possible we have some + + + align:start position:0% +have as soon as possible we have some +sort of B agenda or concept what we're + + align:start position:0% +sort of B agenda or concept what we're + + + align:start position:0% +sort of B agenda or concept what we're +doing and just really run by them and + + align:start position:0% +doing and just really run by them and + + + align:start position:0% +doing and just really run by them and +have them and and have them not just be + + align:start position:0% +have them and and have them not just be + + + align:start position:0% +have them and and have them not just be +J or not just be one person different + + align:start position:0% +J or not just be one person different + + + align:start position:0% +J or not just be one person different +people um different members of the + + align:start position:0% +people um different members of the + + + align:start position:0% +people um different members of the +different organizations this um just + + align:start position:0% +different organizations this um just + + + align:start position:0% +different organizations this um just +like as soon as possible early on back + + align:start position:0% + + + + align:start position:0% + +for I mean I don't know what our agenda + + align:start position:0% +for I mean I don't know what our agenda + + + align:start position:0% +for I mean I don't know what our agenda +was previously I don't think that it be + + align:start position:0% +was previously I don't think that it be + + + align:start position:0% +was previously I don't think that it be +completely shaky after Friday but I do + + align:start position:0% +completely shaky after Friday but I do + + + align:start position:0% +completely shaky after Friday but I do +feel + + align:start position:0% +feel + + + align:start position:0% +feel +that there might be communication + + align:start position:0% +that there might be communication + + + align:start position:0% +that there might be communication +problems they and about whether Cent + + align:start position:0% +problems they and about whether Cent + + + align:start position:0% +problems they and about whether Cent +will continue to work with us but at + + align:start position:0% +will continue to work with us but at + + + align:start position:0% +will continue to work with us but at +some deeper level just feel that this + + align:start position:0% +some deeper level just feel that this + + + align:start position:0% +some deeper level just feel that this +isn't really going in the + + align:start position:0% +isn't really going in the + + + align:start position:0% +isn't really going in the +direction out and hope that a different + + align:start position:0% +direction out and hope that a different + + + align:start position:0% +direction out and hope that a different +group shows up + + align:start position:0% + + + + align:start position:0% + +in one of the things that keeps popping + + align:start position:0% +in one of the things that keeps popping + + + align:start position:0% +in one of the things that keeps popping +up for me and I think it was very well + + align:start position:0% +up for me and I think it was very well + + + align:start position:0% +up for me and I think it was very well +kind of Illustrated both through the + + align:start position:0% +kind of Illustrated both through the + + + align:start position:0% +kind of Illustrated both through the +visit and and uh through some previous + + align:start position:0% +visit and and uh through some previous + + + align:start position:0% +visit and and uh through some previous +dists we've had and that is that this + + align:start position:0% +dists we've had and that is that this + + + align:start position:0% +dists we've had and that is that this +kind of language of and kind of thinking + + align:start position:0% +kind of language of and kind of thinking + + + align:start position:0% +kind of language of and kind of thinking +about economic development is not + + align:start position:0% +about economic development is not + + + align:start position:0% +about economic development is not +something that's just you know as a + + align:start position:0% +something that's just you know as a + + + align:start position:0% +something that's just you know as a +planful thing it's not something just + + align:start position:0% +planful thing it's not something just + + + align:start position:0% +planful thing it's not something just +the community doesn't have experience in + + align:start position:0% +the community doesn't have experience in + + + align:start position:0% +the community doesn't have experience in +but it's also not kind of the language + + align:start position:0% +but it's also not kind of the language + + + align:start position:0% +but it's also not kind of the language +of politics and economic development in + + align:start position:0% +of politics and economic development in + + + align:start position:0% +of politics and economic development in +the city as a whole right so there's + + align:start position:0% +the city as a whole right so there's + + + align:start position:0% +the city as a whole right so there's +this really interesting problem I think + + align:start position:0% +this really interesting problem I think + + + align:start position:0% +this really interesting problem I think +when someone steps up and says well we + + align:start position:0% +when someone steps up and says well we + + + align:start position:0% +when someone steps up and says well we +think we need to do + + align:start position:0% +think we need to do + + + align:start position:0% +think we need to do +this uh then the question is a set of + + align:start position:0% +this uh then the question is a set of + + + align:start position:0% +this uh then the question is a set of +people who who have a set of skills + + align:start position:0% +people who who have a set of skills + + + align:start position:0% +people who who have a set of skills +about helping to do that is how much of + + align:start position:0% +about helping to do that is how much of + + + align:start position:0% +about helping to do that is how much of +your work is about coming up with a plan + + align:start position:0% +your work is about coming up with a plan + + + align:start position:0% +your work is about coming up with a plan +and how much of it is about helping the + + align:start position:0% +and how much of it is about helping the + + + align:start position:0% +and how much of it is about helping the +client really understand what does it + + align:start position:0% +client really understand what does it + + + align:start position:0% +client really understand what does it +mean to try to do Economic Development + + align:start position:0% +mean to try to do Economic Development + + + align:start position:0% +mean to try to do Economic Development +work and how do you what role do you + + align:start position:0% +work and how do you what role do you + + + align:start position:0% +work and how do you what role do you +have in kind of the development of their + + align:start position:0% +have in kind of the development of their + + + align:start position:0% +have in kind of the development of their +thinking and does that become a + + align:start position:0% +thinking and does that become a + + + align:start position:0% +thinking and does that become a +strategic part part of what does it mean + + align:start position:0% +strategic part part of what does it mean + + + align:start position:0% +strategic part part of what does it mean +to actually create a plan you know do + + align:start position:0% +to actually create a plan you know do + + + align:start position:0% +to actually create a plan you know do +you have the responsibility of creating + + align:start position:0% +you have the responsibility of creating + + + align:start position:0% +you have the responsibility of creating +the context where they can be receptive + + align:start position:0% +the context where they can be receptive + + + align:start position:0% +the context where they can be receptive +to it as opposed to you know assuming + + align:start position:0% +to it as opposed to you know assuming + + + align:start position:0% +to it as opposed to you know assuming +that well it's about getting the right + + align:start position:0% +that well it's about getting the right + + + align:start position:0% +that well it's about getting the right +plan of which they'll be acceptive to + + align:start position:0% +plan of which they'll be acceptive to + + + align:start position:0% +plan of which they'll be acceptive to +but that + + align:start position:0% +but that + + + align:start position:0% +but that +somehow there's a responsibility or + + align:start position:0% +somehow there's a responsibility or + + + align:start position:0% +somehow there's a responsibility or +there's a a need a requirement to really + + align:start position:0% +there's a a need a requirement to really + + + align:start position:0% +there's a a need a requirement to really +kind of help them in their own thinking + + align:start position:0% +kind of help them in their own thinking + + + align:start position:0% +kind of help them in their own thinking +in the development of their thinking so + + align:start position:0% +in the development of their thinking so + + + align:start position:0% +in the development of their thinking so +that they can be in the position to + + align:start position:0% +that they can be in the position to + + + align:start position:0% +that they can be in the position to +really kind of grapple with the plan in + + align:start position:0% +really kind of grapple with the plan in + + + align:start position:0% +really kind of grapple with the plan in +the ways in which you think would be + + align:start position:0% +the ways in which you think would be + + + align:start position:0% +the ways in which you think would be +most helpful to them I mean I think I + + align:start position:0% +most helpful to them I mean I think I + + + align:start position:0% +most helpful to them I mean I think I +think that's a very good point I think + + align:start position:0% +think that's a very good point I think + + + align:start position:0% +think that's a very good point I think +it picks up on John I definitely left + + align:start position:0% +it picks up on John I definitely left + + + align:start position:0% +it picks up on John I definitely left +with the sense that you know there's + + align:start position:0% +with the sense that you know there's + + + align:start position:0% +with the sense that you know there's +really a lot + + align:start position:0% +really a lot + + + align:start position:0% +really a lot +more uh discussion and back and forth + + align:start position:0% +more uh discussion and back and forth + + + align:start position:0% +more uh discussion and back and forth +communication I think involved in in in + + align:start position:0% +communication I think involved in in in + + + align:start position:0% +communication I think involved in in in +figuring out what our work should be + + align:start position:0% +figuring out what our work should be + + + align:start position:0% +figuring out what our work should be +than us going off and coming back in + + align:start position:0% +than us going off and coming back in + + + align:start position:0% +than us going off and coming back in +October and I think October is probably + + align:start position:0% +October and I think October is probably + + + align:start position:0% +October and I think October is probably +too late in some ways um um for us to be + + align:start position:0% +too late in some ways um um for us to be + + + align:start position:0% +too late in some ways um um for us to be +the discussion about what we see our + + align:start position:0% +the discussion about what we see our + + + align:start position:0% +the discussion about what we see our +task but that but I think Caesar's + + align:start position:0% +task but that but I think Caesar's + + + align:start position:0% +task but that but I think Caesar's +Point's really an excellent one is that + + align:start position:0% +Point's really an excellent one is that + + + align:start position:0% +Point's really an excellent one is that +I think + + align:start position:0% +I think + + + align:start position:0% +I think +um you know what is the what is the + + align:start position:0% +um you know what is the what is the + + + align:start position:0% +um you know what is the what is the +learning + + align:start position:0% +learning + + + align:start position:0% +learning +process um and and how do we we think + + align:start position:0% +process um and and how do we we think + + + align:start position:0% +process um and and how do we we think +about Framing and + + align:start position:0% +about Framing and + + + align:start position:0% +about Framing and +conceptualizing what we're going to be + + align:start position:0% +conceptualizing what we're going to be + + + align:start position:0% +conceptualizing what we're going to be +doing in a way that that's developmental + + align:start position:0% +doing in a way that that's developmental + + + align:start position:0% +doing in a way that that's developmental +for them that that helps them understand + + align:start position:0% +for them that that helps them understand + + + align:start position:0% +for them that that helps them understand +why we've we're talking about things in + + align:start position:0% +why we've we're talking about things in + + + align:start position:0% +why we've we're talking about things in +certain ways why we see these things as + + align:start position:0% +certain ways why we see these things as + + + align:start position:0% +certain ways why we see these things as +either why we why we endorse some of + + align:start position:0% +either why we why we endorse some of + + + align:start position:0% +either why we why we endorse some of +their ideas or if we are proposing + + align:start position:0% +their ideas or if we are proposing + + + align:start position:0% +their ideas or if we are proposing +different sort of ideas you know what is + + align:start position:0% +different sort of ideas you know what is + + + align:start position:0% +different sort of ideas you know what is +the thinking behind that um I think you + + align:start position:0% +the thinking behind that um I think you + + + align:start position:0% +the thinking behind that um I think you +know that's that that sort of the the + + align:start position:0% +know that's that that sort of the the + + + align:start position:0% +know that's that that sort of the the +sort of deeper communication of of why + + align:start position:0% +sort of deeper communication of of why + + + align:start position:0% +sort of deeper communication of of why +we arrived at what we are and and and + + align:start position:0% +we arrived at what we are and and and + + + align:start position:0% +we arrived at what we are and and and +having that challenge somewhat and + + align:start position:0% +having that challenge somewhat and + + + align:start position:0% +having that challenge somewhat and +having people take + + align:start position:0% +having people take + + + align:start position:0% +having people take +ownership uh and of that is going to be + + align:start position:0% +ownership uh and of that is going to be + + + align:start position:0% +ownership uh and of that is going to be +I think I think important + + align:start position:0% +I think I think important + + + align:start position:0% +I think I think important +um you know because um I think there is + + align:start position:0% +um you know because um I think there is + + + align:start position:0% +um you know because um I think there is +a big there is a big + + align:start position:0% +a big there is a big + + + align:start position:0% +a big there is a big +um um certainly disconnect in terms of + + align:start position:0% +um um certainly disconnect in terms of + + + align:start position:0% +um um certainly disconnect in terms of +the the work people are doing in the + + align:start position:0% +the the work people are doing in the + + + align:start position:0% +the the work people are doing in the +community now the type of relationships + + align:start position:0% +community now the type of relationships + + + align:start position:0% +community now the type of relationships +they have um and what what at least + + align:start position:0% +they have um and what what at least + + + align:start position:0% +they have um and what what at least +typical Economic Development work sort + + align:start position:0% +typical Economic Development work sort + + + align:start position:0% +typical Economic Development work sort +of entails so I think I think there's a + + align:start position:0% +of entails so I think I think there's a + + + align:start position:0% +of entails so I think I think there's a +lot of there's a lot of potential you + + align:start position:0% +lot of there's a lot of potential you + + + align:start position:0% +lot of there's a lot of potential you +know disconnect we just move ahead + + align:start position:0% +know disconnect we just move ahead + + + align:start position:0% +know disconnect we just move ahead +without engaging in that type of + + align:start position:0% +without engaging in that type of + + + align:start position:0% +without engaging in that type of +discussion POs to have three working + + align:start position:0% +discussion POs to have three working + + + align:start position:0% +discussion POs to have three working +simultanously like because I cannot see + + align:start position:0% +simultanously like because I cannot see + + + align:start position:0% +simultanously like because I cannot see +them having ownership role unless they + + align:start position:0% +them having ownership role unless they + + + align:start position:0% +them having ownership role unless they +see some some change going on and then + + align:start position:0% +see some some change going on and then + + + align:start position:0% +see some some change going on and then +they will be more receptive for what + + align:start position:0% +they will be more receptive for what + + + align:start position:0% +they will be more receptive for what +what change might because to them so I'm + + align:start position:0% +what change might because to them so I'm + + + align:start position:0% +what change might because to them so I'm +I'm just wondering like is it possible + + align:start position:0% +I'm just wondering like is it possible + + + align:start position:0% +I'm just wondering like is it possible +to have something changed while still + + align:start position:0% +to have something changed while still + + + align:start position:0% +to have something changed while still +dealing with them like convincing them + + align:start position:0% +dealing with them like convincing them + + + align:start position:0% +dealing with them like convincing them +and yeah during the learning process + + align:start position:0% +and yeah during the learning process + + + align:start position:0% +and yeah during the learning process +yeah I mean that's an interesting idea I + + align:start position:0% +yeah I mean that's an interesting idea I + + + align:start position:0% +yeah I mean that's an interesting idea I +know I've definitely worked on Project + + align:start position:0% +know I've definitely worked on Project + + + align:start position:0% +know I've definitely worked on Project +where you where you you try and identify + + align:start position:0% +where you where you you try and identify + + + align:start position:0% +where you where you you try and identify +a project people can start working on + + align:start position:0% +a project people can start working on + + + align:start position:0% +a project people can start working on +early so that you sort of break down the + + align:start position:0% +early so that you sort of break down the + + + align:start position:0% +early so that you sort of break down the +sort of thinking between you do a plan + + align:start position:0% +sort of thinking between you do a plan + + + align:start position:0% +sort of thinking between you do a plan +and then you begin to implement the plan + + align:start position:0% +and then you begin to implement the plan + + + align:start position:0% +and then you begin to implement the plan +um and that's something we might want to + + align:start position:0% +um and that's something we might want to + + + align:start position:0% +um and that's something we might want to +keep in mind um if we see something like + + align:start position:0% +keep in mind um if we see something like + + + align:start position:0% +keep in mind um if we see something like +that I mean I think that's a huge + + align:start position:0% +that I mean I think that's a huge + + + align:start position:0% +that I mean I think that's a huge +challenge um you know for for the class + + align:start position:0% +challenge um you know for for the class + + + align:start position:0% +challenge um you know for for the class +in the period we + + align:start position:0% +in the period we + + + align:start position:0% +in the period we +have you know to both do a piece of + + align:start position:0% +have you know to both do a piece of + + + align:start position:0% +have you know to both do a piece of +planning work and and sort of get a + + align:start position:0% +planning work and and sort of get a + + + align:start position:0% +planning work and and sort of get a +project going that will bring about + + align:start position:0% +project going that will bring about + + + align:start position:0% +project going that will bring about +change but I do think I do think that's + + align:start position:0% +change but I do think I do think that's + + + align:start position:0% +change but I do think I do think that's +an issue we should be asking ourselves + + align:start position:0% +an issue we should be asking ourselves + + + align:start position:0% +an issue we should be asking ourselves +are there ways we can begin to move + + align:start position:0% +are there ways we can begin to move + + + align:start position:0% +are there ways we can begin to move +forward on action without necessarily + + align:start position:0% +forward on action without necessarily + + + align:start position:0% +forward on action without necessarily +having completed a plan and that might + + align:start position:0% +having completed a plan and that might + + + align:start position:0% +having completed a plan and that might +that might + + align:start position:0% +that might + + + align:start position:0% +that might +involve how we engage with with neon and + + align:start position:0% +involve how we engage with with neon and + + + align:start position:0% +involve how we engage with with neon and +campus committee members and + + align:start position:0% +campus committee members and + + + align:start position:0% +campus committee members and +undertaking the research or having the + + align:start position:0% +undertaking the research or having the + + + align:start position:0% +undertaking the research or having the +discussions or participating in the + + align:start position:0% +discussions or participating in the + + + align:start position:0% +discussions or participating in the +meetings we have in developing the plan + + align:start position:0% +meetings we have in developing the plan + + + align:start position:0% +meetings we have in developing the plan +I mean that might you know that might be + + align:start position:0% +I mean that might you know that might be + + + align:start position:0% +I mean that might you know that might be +one way you know we use the work we're + + align:start position:0% +one way you know we use the work we're + + + align:start position:0% +one way you know we use the work we're +doing to facilitate some relationship + + align:start position:0% +doing to facilitate some relationship + + + align:start position:0% +doing to facilitate some relationship +building if if if we're going to be + + align:start position:0% +building if if if we're going to be + + + align:start position:0% +building if if if we're going to be +meeting with people in the business + + align:start position:0% +meeting with people in the business + + + align:start position:0% +meeting with people in the business +Community inviting a neon worker or + + align:start position:0% +Community inviting a neon worker or + + + align:start position:0% +Community inviting a neon worker or +inviting someone think to attend so you + + align:start position:0% +inviting someone think to attend so you + + + align:start position:0% +inviting someone think to attend so you +know I mean I think there are things we + + align:start position:0% +know I mean I think there are things we + + + align:start position:0% +know I mean I think there are things we +can do in the way we do the work that + + align:start position:0% +can do in the way we do the work that + + + align:start position:0% +can do in the way we do the work that +that will contribute to that somewhat + + align:start position:0% +that will contribute to that somewhat + + + align:start position:0% +that will contribute to that somewhat +um um you know um and and we may find we + + align:start position:0% +um um you know um and and we may find we + + + align:start position:0% +um um you know um and and we may find we +may find by October we have some ideas + + align:start position:0% +may find by October we have some ideas + + + align:start position:0% +may find by October we have some ideas +on some project and we we really want to + + align:start position:0% +on some project and we we really want to + + + align:start position:0% +on some project and we we really want to +begin working with them and implemented + + align:start position:0% +begin working with them and implemented + + + align:start position:0% +begin working with them and implemented +I think we should be very open to that + + align:start position:0% +I think we should be very open to that + + + align:start position:0% +I think we should be very open to that +approach you know if it if it + + align:start position:0% + + + + align:start position:0% + +emerge it Puerto Rican + + align:start position:0% + + + + align:start position:0% + +um and I don't know what kind + + align:start position:0% +um and I don't know what kind + + + align:start position:0% +um and I don't know what kind +of like you know if those are people + + align:start position:0% +of like you know if those are people + + + align:start position:0% +of like you know if those are people +were Bor here + + align:start position:0% +were Bor here + + + align:start position:0% +were Bor here +second here or do you know mostly Second + + align:start position:0% +second here or do you know mostly Second + + + align:start position:0% +second here or do you know mostly Second +Generation and third generation a pretty + + align:start position:0% +Generation and third generation a pretty + + + align:start position:0% +Generation and third generation a pretty +stable community what kind of Lifestyle + + align:start position:0% +stable community what kind of Lifestyle + + + align:start position:0% +stable community what kind of Lifestyle +the first generation had I think have a + + align:start position:0% +the first generation had I think have a + + + align:start position:0% +the first generation had I think have a +lot to do because a lot of times we just + + align:start position:0% +lot to do because a lot of times we just + + + align:start position:0% +lot to do because a lot of times we just +don't have the vision of what it is that + + align:start position:0% +don't have the vision of what it is that + + + align:start position:0% +don't have the vision of what it is that +you're going to see after that we can + + align:start position:0% +you're going to see after that we can + + + align:start position:0% +you're going to see after that we can +come and see this neighborhood needs + + align:start position:0% +come and see this neighborhood needs + + + align:start position:0% +come and see this neighborhood needs +some work but some of those people is + + align:start position:0% +some work but some of those people is + + + align:start position:0% +some work but some of those people is +this is this is good this is it used to + + align:start position:0% +this is this is good this is it used to + + + align:start position:0% +this is this is good this is it used to +be work in situations like that so + + align:start position:0% +be work in situations like that so + + + align:start position:0% +be work in situations like that so +sometimes a different + + align:start position:0% +sometimes a different + + + align:start position:0% +sometimes a different +Vision um so sometimes helping compare + + align:start position:0% +Vision um so sometimes helping compare + + + align:start position:0% +Vision um so sometimes helping compare +what this could be see the past and see + + align:start position:0% +what this could be see the past and see + + + align:start position:0% +what this could be see the past and see +the future what what it is right now and + + align:start position:0% +the future what what it is right now and + + + align:start position:0% +the future what what it is right now and +what it could be helps people take more + + align:start position:0% +what it could be helps people take more + + + align:start position:0% +what it could be helps people take more +initiative of where they want to go next + + align:start position:0% +initiative of where they want to go next + + + align:start position:0% +initiative of where they want to go next +we in a neighbor work in a neighborhood + + align:start position:0% +we in a neighbor work in a neighborhood + + + align:start position:0% +we in a neighbor work in a neighborhood +before there was before there was + + align:start position:0% +before there was before there was + + + align:start position:0% +before there was before there was +absolutely all the stores was closed and + + align:start position:0% +absolutely all the stores was closed and + + + align:start position:0% +absolutely all the stores was closed and +much like the came they start open their + + align:start position:0% +much like the came they start open their + + + align:start position:0% +much like the came they start open their +stores and of course they had no + + align:start position:0% +stores and of course they had no + + + align:start position:0% +stores and of course they had no +business plan they had no IDE is the the + + align:start position:0% +business plan they had no IDE is the the + + + align:start position:0% +business plan they had no IDE is the the +man will come to start to do and if they + + align:start position:0% +man will come to start to do and if they + + + align:start position:0% +man will come to start to do and if they +see this business was working then + + align:start position:0% +see this business was working then + + + align:start position:0% +see this business was working then +everybody else would go like right now + + align:start position:0% +everybody else would go like right now + + + align:start position:0% +everybody else would go like right now +we have 15 + + align:start position:0% +we have 15 + + + align:start position:0% +we have 15 +head not including the people that doing + + align:start position:0% +head not including the people that doing + + + align:start position:0% +head not including the people that doing +this in the houses so now the people had + + align:start position:0% +this in the houses so now the people had + + + align:start position:0% +this in the houses so now the people had +5,000 U you know + + align:start position:0% +5,000 U you know + + + align:start position:0% +5,000 U you know +$50,000 open up their business it's in a + + align:start position:0% +$50,000 open up their business it's in a + + + align:start position:0% +$50,000 open up their business it's in a +huge Dr now once all this development + + align:start position:0% +huge Dr now once all this development + + + align:start position:0% +huge Dr now once all this development +start to happen the people owns the + + align:start position:0% +start to happen the people owns the + + + align:start position:0% +start to happen the people owns the +business oh this is great you know + + align:start position:0% +business oh this is great you know + + + align:start position:0% +business oh this is great you know +everybody we have business this looks + + align:start position:0% +everybody we have business this looks + + + align:start position:0% +everybody we have business this looks +good now I can another development to of + + align:start position:0% +good now I can another development to of + + + align:start position:0% +good now I can another development to of +this so now they're going to invest + + align:start position:0% +this so now they're going to invest + + + align:start position:0% +this so now they're going to invest +about 65 to 70,000 + + align:start position:0% +about 65 to 70,000 + + + align:start position:0% +about 65 to 70,000 +million and then all those business + + align:start position:0% +million and then all those business + + + align:start position:0% +million and then all those business +that's there so now is only the + + align:start position:0% +that's there so now is only the + + + align:start position:0% +that's there so now is only the +this new developers only going to be not + + align:start position:0% +this new developers only going to be not + + + align:start position:0% +this new developers only going to be not +bra because the r going be so high so + + align:start position:0% +bra because the r going be so high so + + + align:start position:0% +bra because the r going be so high so +and less than 20 years I mean we say for + + align:start position:0% +and less than 20 years I mean we say for + + + align:start position:0% +and less than 20 years I mean we say for +the Last 5 Years something really good + + align:start position:0% +the Last 5 Years something really good + + + align:start position:0% +the Last 5 Years something really good +happened of helping them open their own + + align:start position:0% +happened of helping them open their own + + + align:start position:0% +happened of helping them open their own +business but they didn't have a plan of + + align:start position:0% +business but they didn't have a plan of + + + align:start position:0% +business but they didn't have a plan of +how is this going what is this going + + align:start position:0% +how is this going what is this going + + + align:start position:0% +how is this going what is this going +what kind of impact is going to be now + + align:start position:0% +what kind of impact is going to be now + + + align:start position:0% +what kind of impact is going to be now +and what is going to be five 10 years 20 + + align:start position:0% +and what is going to be five 10 years 20 + + + align:start position:0% +and what is going to be five 10 years 20 +years from now CU for some of those + + align:start position:0% +years from now CU for some of those + + + align:start position:0% +years from now CU for some of those +business in order for them to make of + + align:start position:0% +business in order for them to make of + + + align:start position:0% +business in order for them to make of +what they had already invest they need + + align:start position:0% +what they had already invest they need + + + align:start position:0% +what they had already invest they need +to be in business at least for five + + align:start position:0% +to be in business at least for five + + + align:start position:0% +to be in business at least for five +years so some of those not going for the + + align:start position:0% +years so some of those not going for the + + + align:start position:0% +years so some of those not going for the +next years so help can people to think + + align:start position:0% +next years so help can people to think + + + align:start position:0% +next years so help can people to think +about it what the plan in long term it + + align:start position:0% +about it what the plan in long term it + + + align:start position:0% +about it what the plan in long term it +could be better this because this + + align:start position:0% +could be better this because this + + + align:start position:0% +could be better this because this +particular Community they could L the + + align:start position:0% +particular Community they could L the + + + align:start position:0% +particular Community they could L the +business on the next + + align:start position:0% +business on the next + + + align:start position:0% +business on the next +years so that connects a lot with what + + align:start position:0% +years so that connects a lot with what + + + align:start position:0% +years so that connects a lot with what +you saw when you were talking to one in + + align:start position:0% +you saw when you were talking to one in + + + align:start position:0% +you saw when you were talking to one in +the business can you say a little bit + + align:start position:0% +the business can you say a little bit + + + align:start position:0% +the business can you say a little bit +about that story you had when you talked + + align:start position:0% +about that story you had when you talked + + + align:start position:0% +about that story you had when you talked +with the guy about the store yeah um I + + align:start position:0% +with the guy about the store yeah um I + + + align:start position:0% +with the guy about the store yeah um I +was walking with Bill and we stopped in + + align:start position:0% +was walking with Bill and we stopped in + + + align:start position:0% +was walking with Bill and we stopped in +one of the little local bodegas and I + + align:start position:0% +one of the little local bodegas and I + + + align:start position:0% +one of the little local bodegas and I +asked the owner about + + align:start position:0% +asked the owner about + + + align:start position:0% +asked the owner about +um just about his business and it's + + align:start position:0% +um just about his business and it's + + + align:start position:0% +um just about his business and it's +history + + align:start position:0% +history + + + align:start position:0% +history +and uh because there's a for sale sign + + align:start position:0% +and uh because there's a for sale sign + + + align:start position:0% +and uh because there's a for sale sign +on it and we were curious as to why the + + align:start position:0% +on it and we were curious as to why the + + + align:start position:0% +on it and we were curious as to why the +business was for sale and he said well I + + align:start position:0% +business was for sale and he said well I + + + align:start position:0% +business was for sale and he said well I +started it 3 years + + align:start position:0% +started it 3 years + + + align:start position:0% +started it 3 years +ago and after a year or so sold it and + + align:start position:0% +ago and after a year or so sold it and + + + align:start position:0% +ago and after a year or so sold it and +then bought it back and now I'm selling + + align:start position:0% +then bought it back and now I'm selling + + + align:start position:0% +then bought it back and now I'm selling +it + + align:start position:0% +it + + + align:start position:0% +it +again and um like really well + + align:start position:0% +again and um like really well + + + align:start position:0% +again and um like really well +why you know what did you do when you + + align:start position:0% +why you know what did you do when you + + + align:start position:0% +why you know what did you do when you +didn't know that and uh he said well I + + align:start position:0% +didn't know that and uh he said well I + + + align:start position:0% +didn't know that and uh he said well I +have this other store and it's much + + align:start position:0% +have this other store and it's much + + + align:start position:0% +have this other store and it's much +bigger than this one and and what came + + align:start position:0% +bigger than this one and and what came + + + align:start position:0% +bigger than this one and and what came +through in the conversation eventually + + align:start position:0% +through in the conversation eventually + + + align:start position:0% +through in the conversation eventually +was that he sort of bases himself on the + + align:start position:0% +was that he sort of bases himself on the + + + align:start position:0% +was that he sort of bases himself on the +one big story that he owns and that's + + align:start position:0% +one big story that he owns and that's + + + align:start position:0% +one big story that he owns and that's +like his foundation his entrepreneurial + + align:start position:0% +like his foundation his entrepreneurial + + + align:start position:0% +like his foundation his entrepreneurial +Foundation I guess and then + + align:start position:0% +Foundation I guess and then + + + align:start position:0% +Foundation I guess and then +this store when he feels like he has the + + align:start position:0% +this store when he feels like he has the + + + align:start position:0% +this store when he feels like he has the +money and it's like a good time or I + + align:start position:0% +money and it's like a good time or I + + + align:start position:0% +money and it's like a good time or I +don't know all of the conditions that + + align:start position:0% +don't know all of the conditions that + + + align:start position:0% +don't know all of the conditions that +decide this for but he buys this other + + align:start position:0% +decide this for but he buys this other + + + align:start position:0% +decide this for but he buys this other +store and runs it and just sells little + + align:start position:0% +store and runs it and just sells little + + + align:start position:0% +store and runs it and just sells little +foods and things there the other + + align:start position:0% +foods and things there the other + + + align:start position:0% +foods and things there the other +business is larger appliances I think or + + align:start position:0% +business is larger appliances I think or + + + align:start position:0% +business is larger appliances I think or +at least includes them and um but then + + align:start position:0% +at least includes them and um but then + + + align:start position:0% +at least includes them and um but then +when things get tight he sells the + + align:start position:0% +when things get tight he sells the + + + align:start position:0% +when things get tight he sells the +smaller business because he needs the + + align:start position:0% +smaller business because he needs the + + + align:start position:0% +smaller business because he needs the +fast cash and goes back and runs only + + align:start position:0% +fast cash and goes back and runs only + + + align:start position:0% +fast cash and goes back and runs only +the bigger one and he's he seemed + + align:start position:0% +the bigger one and he's he seemed + + + align:start position:0% +the bigger one and he's he seemed +perfectly comfortable with moving in and + + align:start position:0% +perfectly comfortable with moving in and + + + align:start position:0% +perfectly comfortable with moving in and +out of that and there wasn't like any + + align:start position:0% +out of that and there wasn't like any + + + align:start position:0% +out of that and there wasn't like any +big scheme to you know there wasn't any + + align:start position:0% +big scheme to you know there wasn't any + + + align:start position:0% +big scheme to you know there wasn't any +it didn't seem to be like part of some + + align:start position:0% +it didn't seem to be like part of some + + + align:start position:0% +it didn't seem to be like part of some +larger plan it was just well sometimes I + + align:start position:0% +larger plan it was just well sometimes I + + + align:start position:0% +larger plan it was just well sometimes I +own this store when I can afford it and + + align:start position:0% +own this store when I can afford it and + + + align:start position:0% +own this store when I can afford it and +sometimes I don't but things get a + + align:start position:0% +sometimes I don't but things get a + + + align:start position:0% +sometimes I don't but things get a +little rough and it moves in and out of + + align:start position:0% +little rough and it moves in and out of + + + align:start position:0% +little rough and it moves in and out of +that that's + + align:start position:0% + + + + align:start position:0% + +interesting another issue that sort of + + align:start position:0% +interesting another issue that sort of + + + align:start position:0% +interesting another issue that sort of +came to mind U as U we had a um train as + + align:start position:0% +came to mind U as U we had a um train as + + + align:start position:0% +came to mind U as U we had a um train as +well this morning that the conversations + + align:start position:0% +well this morning that the conversations + + + align:start position:0% +well this morning that the conversations +with the state or with City official to + + align:start position:0% + + + + align:start position:0% + +produce interesting + + align:start position:0% + + + + align:start position:0% + +conversations or at least Center has + + align:start position:0% +conversations or at least Center has + + + align:start position:0% +conversations or at least Center has +information on if such conversations + + align:start position:0% +information on if such conversations + + + align:start position:0% +information on if such conversations +took place between + + align:start position:0% + + + + align:start position:0% + +we have not a lot that would really uh + + align:start position:0% +we have not a lot that would really uh + + + align:start position:0% +we have not a lot that would really uh +impact on this I'm actually want to just + + align:start position:0% +impact on this I'm actually want to just + + + align:start position:0% +impact on this I'm actually want to just +show + + align:start position:0% + + + + align:start position:0% + +oops I want a + + align:start position:0% + + + + align:start position:0% + +computer recalling some the things that + + align:start position:0% +computer recalling some the things that + + + align:start position:0% +computer recalling some the things that +je said it sounds like they've actually + + align:start position:0% +je said it sounds like they've actually + + + align:start position:0% +je said it sounds like they've actually +very impressive relationship with the + + align:start position:0% +very impressive relationship with the + + + align:start position:0% +very impressive relationship with the +state with some some elements of the + + align:start position:0% +state with some some elements of the + + + align:start position:0% +state with some some elements of the +state + + align:start position:0% +state + + + align:start position:0% +state +self highly specialized programs they've + + align:start position:0% +self highly specialized programs they've + + + align:start position:0% +self highly specialized programs they've +done + + align:start position:0% + + + + align:start position:0% + +withy so obviously there are some + + align:start position:0% +withy so obviously there are some + + + align:start position:0% +withy so obviously there are some +departments within State apparatus that + + align:start position:0% +departments within State apparatus that + + + align:start position:0% +departments within State apparatus that +they have been very + + align:start position:0% + + + + align:start position:0% + +successful for development + + align:start position:0% +successful for development + + + align:start position:0% +successful for development +feel that those are at least if we were + + align:start position:0% +feel that those are at least if we were + + + align:start position:0% +feel that those are at least if we were +to have those convers at least Avenues + + align:start position:0% +to have those convers at least Avenues + + + align:start position:0% +to have those convers at least Avenues +in which we could point to and say + + align:start position:0% +in which we could point to and say + + + align:start position:0% +in which we could point to and say +actually successful around a whole set + + align:start position:0% +actually successful around a whole set + + + align:start position:0% +actually successful around a whole set +of Economic Development activities + + align:start position:0% +of Economic Development activities + + + align:start position:0% +of Economic Development activities +potentially a set of activities that + + align:start position:0% +potentially a set of activities that + + + align:start position:0% +potentially a set of activities that +have some economic development + + align:start position:0% +have some economic development + + + align:start position:0% +have some economic development +effect yeah another way to look at that + + align:start position:0% +effect yeah another way to look at that + + + align:start position:0% +effect yeah another way to look at that +which I've been thinking about is + + align:start position:0% +which I've been thinking about is + + + align:start position:0% +which I've been thinking about is +they've clearly accomplished a lot um + + align:start position:0% +they've clearly accomplished a lot um + + + align:start position:0% +they've clearly accomplished a lot um +and they clearly have some real + + align:start position:0% +and they clearly have some real + + + align:start position:0% +and they clearly have some real +organizational strengths and to what + + align:start position:0% +organizational strengths and to what + + + align:start position:0% +organizational strengths and to what +extent and and that's sort of this + + align:start position:0% +extent and and that's sort of this + + + align:start position:0% +extent and and that's sort of this +question of of you know how do we take + + align:start position:0% +question of of you know how do we take + + + align:start position:0% +question of of you know how do we take +this how do we perhaps apply this + + align:start position:0% +this how do we perhaps apply this + + + align:start position:0% +this how do we perhaps apply this +populationbased approach in other words + + align:start position:0% +populationbased approach in other words + + + align:start position:0% +populationbased approach in other words +what are their + + align:start position:0% +what are their + + + align:start position:0% +what are their +strengths + + align:start position:0% +strengths + + + align:start position:0% +strengths +uh and and how could that inform the + + align:start position:0% +uh and and how could that inform the + + + align:start position:0% +uh and and how could that inform the +approach we take you know if we realiz + + align:start position:0% +approach we take you know if we realiz + + + align:start position:0% +approach we take you know if we realiz +if our if our first step forward in any + + align:start position:0% +if our if our first step forward in any + + + align:start position:0% +if our if our first step forward in any +sort of Economic Development initiative + + align:start position:0% +sort of Economic Development initiative + + + align:start position:0% +sort of Economic Development initiative +is going to be built around the campus + + align:start position:0% +is going to be built around the campus + + + align:start position:0% +is going to be built around the campus +committee + + align:start position:0% +committee + + + align:start position:0% +committee +organizations then we have you know + + align:start position:0% +organizations then we have you know + + + align:start position:0% +organizations then we have you know +trying to understand how they approach + + align:start position:0% +trying to understand how they approach + + + align:start position:0% +trying to understand how they approach +their work think about their work how we + + align:start position:0% +their work think about their work how we + + + align:start position:0% +their work think about their work how we +might be able to translate that approach + + align:start position:0% +might be able to translate that approach + + + align:start position:0% +might be able to translate that approach +into Economic Development work so so + + align:start position:0% +into Economic Development work so so + + + align:start position:0% +into Economic Development work so so +that we can we can sort of build on + + align:start position:0% +that we can we can sort of build on + + + align:start position:0% +that we can we can sort of build on +their own their own capacities their own + + align:start position:0% +their own their own capacities their own + + + align:start position:0% +their own their own capacities their own +relationships their own way of doing + + align:start position:0% +relationships their own way of doing + + + align:start position:0% +relationships their own way of doing +things we may have more success um in + + align:start position:0% +things we may have more success um in + + + align:start position:0% +things we may have more success um in +getting the work accepted and getting + + align:start position:0% +getting the work accepted and getting + + + align:start position:0% +getting the work accepted and getting +the work U forward and and that's one + + align:start position:0% +the work U forward and and that's one + + + align:start position:0% +the work U forward and and that's one +approach I mean um you know so and I + + align:start position:0% +approach I mean um you know so and I + + + align:start position:0% +approach I mean um you know so and I +think it's worth exploring that on the + + align:start position:0% +think it's worth exploring that on the + + + align:start position:0% +think it's worth exploring that on the +other hand people you you might come to + + align:start position:0% +other hand people you you might come to + + + align:start position:0% +other hand people you you might come to +the feeling that that's just too big a + + align:start position:0% +the feeling that that's just too big a + + + align:start position:0% +the feeling that that's just too big a +disconnect that's that's not and you + + align:start position:0% +disconnect that's that's not and you + + + align:start position:0% +disconnect that's that's not and you +know the the tasks they need to do are + + align:start position:0% +know the the tasks they need to do are + + + align:start position:0% +know the the tasks they need to do are +so different that we really have to + + align:start position:0% +so different that we really have to + + + align:start position:0% +so different that we really have to +approach the work in a different way and + + align:start position:0% +approach the work in a different way and + + + align:start position:0% +approach the work in a different way and +I think I think that you might come to + + align:start position:0% +I think I think that you might come to + + + align:start position:0% +I think I think that you might come to +that conclusion as well but I think it's + + align:start position:0% +that conclusion as well but I think it's + + + align:start position:0% +that conclusion as well but I think it's +a good question to ask where are they + + align:start position:0% +a good question to ask where are they + + + align:start position:0% +a good question to ask where are they +starting from and how do we engage with + + align:start position:0% +starting from and how do we engage with + + + align:start position:0% +starting from and how do we engage with +them or where they're starting from um + + align:start position:0% +them or where they're starting from um + + + align:start position:0% +them or where they're starting from um +in terms of thinking about an economic + + align:start position:0% +in terms of thinking about an economic + + + align:start position:0% +in terms of thinking about an economic +development um um but but I would + + align:start position:0% +development um um but but I would + + + align:start position:0% +development um um but but I would +generally + + align:start position:0% +generally + + + align:start position:0% +generally +think setting aside some time to have a + + align:start position:0% +think setting aside some time to have a + + + align:start position:0% +think setting aside some time to have a +broader set of discussions s fairly soon + + align:start position:0% +broader set of discussions s fairly soon + + + align:start position:0% +broader set of discussions s fairly soon +is going to be important to that work + + align:start position:0% +is going to be important to that work + + + align:start position:0% +is going to be important to that work +both within the community and and within + + align:start position:0% +both within the community and and within + + + align:start position:0% +both within the community and and within +quote other stakeholders in the city the + + align:start position:0% +quote other stakeholders in the city the + + + align:start position:0% +quote other stakeholders in the city the +region the state um because I think it's + + align:start position:0% +region the state um because I think it's + + + align:start position:0% +region the state um because I think it's +going to be hard to to feel like we have + + align:start position:0% +going to be hard to to feel like we have + + + align:start position:0% +going to be hard to to feel like we have +a good understanding of of the + + align:start position:0% +a good understanding of of the + + + align:start position:0% +a good understanding of of the +opportunities for the community and + + align:start position:0% +opportunities for the community and + + + align:start position:0% +opportunities for the community and +where resources might be and why things + + align:start position:0% +where resources might be and why things + + + align:start position:0% +where resources might be and why things +may have worked or not worked in the + + align:start position:0% +may have worked or not worked in the + + + align:start position:0% +may have worked or not worked in the +past so that's probably one activity we + + align:start position:0% +past so that's probably one activity we + + + align:start position:0% +past so that's probably one activity we +should be be thinking about + + align:start position:0% + + + + align:start position:0% + +tackling I had been looking on my + + align:start position:0% +tackling I had been looking on my + + + align:start position:0% +tackling I had been looking on my +computer because I know I got an email + + align:start position:0% +computer because I know I got an email + + + align:start position:0% +computer because I know I got an email +from Jeff yesterday and I couldn't + + align:start position:0% +from Jeff yesterday and I couldn't + + + align:start position:0% +from Jeff yesterday and I couldn't +remember exactly what it said but part + + align:start position:0% +remember exactly what it said but part + + + align:start position:0% +remember exactly what it said but part +of it was basically that oh we need to + + align:start position:0% +of it was basically that oh we need to + + + align:start position:0% +of it was basically that oh we need to +make sure the students get to talk to + + align:start position:0% +make sure the students get to talk to + + + align:start position:0% +make sure the students get to talk to +Katie and Carlos and + + align:start position:0% +Katie and Carlos and + + + align:start position:0% +Katie and Carlos and +to Steve at Bay State and stuff like + + align:start position:0% +to Steve at Bay State and stuff like + + + align:start position:0% +to Steve at Bay State and stuff like +that so I think in some sense he's + + align:start position:0% +that so I think in some sense he's + + + align:start position:0% +that so I think in some sense he's +recognizing also the need to make sure + + align:start position:0% +recognizing also the need to make sure + + + align:start position:0% +recognizing also the need to make sure +there's a broader audience uh one part + + align:start position:0% +there's a broader audience uh one part + + + align:start position:0% +there's a broader audience uh one part +about this I just want to uh kind of + + align:start position:0% +about this I just want to uh kind of + + + align:start position:0% +about this I just want to uh kind of +reaffirm what uh affirm What + + align:start position:0% +reaffirm what uh affirm What + + + align:start position:0% +reaffirm what uh affirm What +U uh Carlo said is and thinking about + + align:start position:0% +U uh Carlo said is and thinking about + + + align:start position:0% +U uh Carlo said is and thinking about +this as you're kind of you know being + + align:start position:0% +this as you're kind of you know being + + + align:start position:0% +this as you're kind of you know being +the The Firm organization that's saying + + align:start position:0% +the The Firm organization that's saying + + + align:start position:0% +the The Firm organization that's saying +you know it's been asked to do this work + + align:start position:0% +you know it's been asked to do this work + + + align:start position:0% +you know it's been asked to do this work +uh for this community is I think it's + + align:start position:0% +uh for this community is I think it's + + + align:start position:0% +uh for this community is I think it's +really important that you're clear about + + align:start position:0% +really important that you're clear about + + + align:start position:0% +really important that you're clear about +what you need in order to be + + align:start position:0% +what you need in order to be + + + align:start position:0% +what you need in order to be +successful and that you can kind of + + align:start position:0% +successful and that you can kind of + + + align:start position:0% +successful and that you can kind of +communicate that to folks and right now + + align:start position:0% +communicate that to folks and right now + + + align:start position:0% +communicate that to folks and right now +you know I mean you have the attention + + align:start position:0% +you know I mean you have the attention + + + align:start position:0% +you know I mean you have the attention +of a few people who are part of the + + align:start position:0% +of a few people who are part of the + + + align:start position:0% +of a few people who are part of the +campus committee and I I think being + + align:start position:0% +campus committee and I I think being + + + align:start position:0% +campus committee and I I think being +able to say you know this is the + + align:start position:0% +able to say you know this is the + + + align:start position:0% +able to say you know this is the +accesses we need access we need there + + align:start position:0% +accesses we need access we need there + + + align:start position:0% +accesses we need access we need there +people we need to talk to this time + + align:start position:0% +people we need to talk to this time + + + align:start position:0% +people we need to talk to this time +commitment we need these are the things + + align:start position:0% +commitment we need these are the things + + + align:start position:0% +commitment we need these are the things +we kind of need in order to be able to + + align:start position:0% +we kind of need in order to be able to + + + align:start position:0% +we kind of need in order to be able to +do what we're trying to do is a + + align:start position:0% +do what we're trying to do is a + + + align:start position:0% +do what we're trying to do is a +reasonable thing for you to communicate + + align:start position:0% +reasonable thing for you to communicate + + + align:start position:0% +reasonable thing for you to communicate +back to the group uh that you know it + + align:start position:0% +back to the group uh that you know it + + + align:start position:0% +back to the group uh that you know it +doesn't have to be kind of a passive + + align:start position:0% +doesn't have to be kind of a passive + + + align:start position:0% +doesn't have to be kind of a passive +thing that you only have to deal with + + align:start position:0% +thing that you only have to deal with + + + align:start position:0% +thing that you only have to deal with +what's presented but I think folks need + + align:start position:0% +what's presented but I think folks need + + + align:start position:0% +what's presented but I think folks need +to know you know what you require in + + align:start position:0% +to know you know what you require in + + + align:start position:0% +to know you know what you require in +order to be + + align:start position:0% +order to be + + + align:start position:0% +order to be +successful and that they will I think + + align:start position:0% +successful and that they will I think + + + align:start position:0% +successful and that they will I think +they will help you do that if they kind + + align:start position:0% +they will help you do that if they kind + + + align:start position:0% +they will help you do that if they kind +of know what it is and we're very clear + + align:start position:0% +of know what it is and we're very clear + + + align:start position:0% +of know what it is and we're very clear +about it + + align:start position:0% + + + + align:start position:0% + +so it's a communication challenge I + + align:start position:0% +so it's a communication challenge I + + + align:start position:0% +so it's a communication challenge I +think you have with the with the campus + + align:start position:0% +think you have with the with the campus + + + align:start position:0% +think you have with the with the campus +committee with this work group that I + + align:start position:0% +committee with this work group that I + + + align:start position:0% +committee with this work group that I +think you need to establish really kind + + align:start position:0% +think you need to establish really kind + + + align:start position:0% +think you need to establish really kind +of early + + align:start position:0% +of early + + + align:start position:0% +of early +on how to do that and I think we're + + align:start position:0% +on how to do that and I think we're + + + align:start position:0% +on how to do that and I think we're +moving to a place where Carl and I don't + + align:start position:0% +moving to a place where Carl and I don't + + + align:start position:0% +moving to a place where Carl and I don't +want to be + + align:start position:0% +want to be + + + align:start position:0% +want to be +the the the uh interveners in that + + align:start position:0% +the the the uh interveners in that + + + align:start position:0% +the the the uh interveners in that +process but having it really be the + + align:start position:0% +process but having it really be the + + + align:start position:0% +process but having it really be the +negotiators around that + + align:start position:0% +negotiators around that + + + align:start position:0% +negotiators around that +process I one of our gos for this week + + align:start position:0% +process I one of our gos for this week + + + align:start position:0% +process I one of our gos for this week +between today and and tomorrow I mean + + align:start position:0% +between today and and tomorrow I mean + + + align:start position:0% +between today and and tomorrow I mean +then Thursday is to begin to sort of + + align:start position:0% +then Thursday is to begin to sort of + + + align:start position:0% +then Thursday is to begin to sort of +figure out how we want to tackle the + + align:start position:0% +figure out how we want to tackle the + + + align:start position:0% +figure out how we want to tackle the +work and how we're going to organize + + align:start position:0% +work and how we're going to organize + + + align:start position:0% +work and how we're going to organize +ourselves around it um at least over the + + align:start position:0% +ourselves around it um at least over the + + + align:start position:0% +ourselves around it um at least over the +first phase um so that will hopefully + + align:start position:0% +first phase um so that will hopefully + + + align:start position:0% +first phase um so that will hopefully +Empower everyone to to go out and and + + align:start position:0% +Empower everyone to to go out and and + + + align:start position:0% +Empower everyone to to go out and and +begin to to take the initiative around + + align:start position:0% +begin to to take the initiative around + + + align:start position:0% +begin to to take the initiative around +around contact with neon and + + align:start position:0% +around contact with neon and + + + align:start position:0% +around contact with neon and +Etc I guess question + + align:start position:0% + + + + align:start position:0% + +you talk a little bit + + align:start position:0% +you talk a little bit + + + align:start position:0% +you talk a little bit +about you + + align:start position:0% + + + + align:start position:0% + +involved for a few + + align:start position:0% +involved for a few + + + align:start position:0% +involved for a few +years I don't even know um and I guess + + align:start position:0% +years I don't even know um and I guess + + + align:start position:0% +years I don't even know um and I guess +I'm + + align:start position:0% +I'm + + + align:start position:0% +I'm +curious + + align:start position:0% +curious + + + align:start position:0% +curious +how the student products have been used + + align:start position:0% +how the student products have been used + + + align:start position:0% +how the student products have been used +by this past have they been um realize + + align:start position:0% +by this past have they been um realize + + + align:start position:0% +by this past have they been um realize +that they' been completely different + + align:start position:0% +that they' been completely different + + + align:start position:0% +that they' been completely different +types of t ask but the product of Sol + + align:start position:0% +types of t ask but the product of Sol + + + align:start position:0% +types of t ask but the product of Sol +has been viewed as actionable by the + + align:start position:0% +has been viewed as actionable by the + + + align:start position:0% +has been viewed as actionable by the +recipients or more like education piece + + align:start position:0% +recipients or more like education piece + + + align:start position:0% +recipients or more like education piece +or you know how would you describe well + + align:start position:0% +or you know how would you describe well + + + align:start position:0% +or you know how would you describe well +let me take the the the last course on + + align:start position:0% +let me take the the the last course on + + + align:start position:0% +let me take the the the last course on +the campus concept we did that + + align:start position:0% +the campus concept we did that + + + align:start position:0% +the campus concept we did that +uh one of the things that was very clear + + align:start position:0% +uh one of the things that was very clear + + + align:start position:0% +uh one of the things that was very clear +and that the community asked for and the + + align:start position:0% +and that the community asked for and the + + + align:start position:0% +and that the community asked for and the +class went back and forth with a morning + + align:start position:0% +class went back and forth with a morning + + + align:start position:0% +class went back and forth with a morning +around is that the community is very + + align:start position:0% +around is that the community is very + + + align:start position:0% +around is that the community is very +clear that they wanted actionable + + align:start position:0% +clear that they wanted actionable + + + align:start position:0% +clear that they wanted actionable +items on the plan they wanted things + + align:start position:0% +items on the plan they wanted things + + + align:start position:0% +items on the plan they wanted things +that they could do within the next 6 to + + align:start position:0% +that they could do within the next 6 to + + + align:start position:0% +that they could do within the next 6 to +12 months as well as a broader plan that + + align:start position:0% +12 months as well as a broader plan that + + + align:start position:0% +12 months as well as a broader plan that +that fit + + align:start position:0% +that fit + + + align:start position:0% +that fit +into and there were a number of + + align:start position:0% +into and there were a number of + + + align:start position:0% +into and there were a number of +recommendations actually that the class + + align:start position:0% +recommendations actually that the class + + + align:start position:0% +recommendations actually that the class +worked on that they thought could be + + align:start position:0% +worked on that they thought could be + + + align:start position:0% +worked on that they thought could be +accomplished in the next 6 to 12 months + + align:start position:0% +accomplished in the next 6 to 12 months + + + align:start position:0% +accomplished in the next 6 to 12 months +of which I think most of the they the + + align:start position:0% +of which I think most of the they the + + + align:start position:0% +of which I think most of the they the +community has acted on uh I'll give you + + align:start position:0% +community has acted on uh I'll give you + + + align:start position:0% +community has acted on uh I'll give you +three examples it used to be that there + + align:start position:0% +three examples it used to be that there + + + align:start position:0% +three examples it used to be that there +was a campus committee and then there + + align:start position:0% +was a campus committee and then there + + + align:start position:0% +was a campus committee and then there +was a steering committee that ran neon + + align:start position:0% +was a steering committee that ran neon + + + align:start position:0% +was a steering committee that ran neon +and neon was actually separate from the + + align:start position:0% +and neon was actually separate from the + + + align:start position:0% +and neon was actually separate from the +campus committee and one of the things + + align:start position:0% +campus committee and one of the things + + + align:start position:0% +campus committee and one of the things +that came out of is is the group said + + align:start position:0% +that came out of is is the group said + + + align:start position:0% +that came out of is is the group said +look neon needs to be responsive + + align:start position:0% +look neon needs to be responsive + + + align:start position:0% +look neon needs to be responsive +response needs to be a subset of the + + align:start position:0% +response needs to be a subset of the + + + align:start position:0% +response needs to be a subset of the +campus committee not a separate thing + + align:start position:0% +campus committee not a separate thing + + + align:start position:0% +campus committee not a separate thing +and actually the director of neon needs + + align:start position:0% +and actually the director of neon needs + + + align:start position:0% +and actually the director of neon needs +to be hired by the campus committee and + + align:start position:0% +to be hired by the campus committee and + + + align:start position:0% +to be hired by the campus committee and +be responsible to the campus committee + + align:start position:0% +be responsible to the campus committee + + + align:start position:0% +be responsible to the campus committee +and so they actually changed that + + align:start position:0% +and so they actually changed that + + + align:start position:0% +and so they actually changed that +organizational Arrangement they also + + align:start position:0% +organizational Arrangement they also + + + align:start position:0% +organizational Arrangement they also +talked about the need to hire someone + + align:start position:0% +talked about the need to hire someone + + + align:start position:0% +talked about the need to hire someone +who is going to be a coordinator for the + + align:start position:0% +who is going to be a coordinator for the + + + align:start position:0% +who is going to be a coordinator for the +campus itself which Vanessa I think some + + align:start position:0% +campus itself which Vanessa I think some + + + align:start position:0% +campus itself which Vanessa I think some +of you met Vanessa they actually then + + align:start position:0% +of you met Vanessa they actually then + + + align:start position:0% +of you met Vanessa they actually then +put money into hiring her to do that + + align:start position:0% +put money into hiring her to do that + + + align:start position:0% +put money into hiring her to do that +there were a set of other activities + + align:start position:0% +there were a set of other activities + + + align:start position:0% +there were a set of other activities +that they thought could happen and some + + align:start position:0% +that they thought could happen and some + + + align:start position:0% +that they thought could happen and some +changes in the building that could + + align:start position:0% +changes in the building that could + + + align:start position:0% +changes in the building that could +happen so when Peter took us on the tour + + align:start position:0% +happen so when Peter took us on the tour + + + align:start position:0% +happen so when Peter took us on the tour +and you remember the room he said there + + align:start position:0% +and you remember the room he said there + + + align:start position:0% +and you remember the room he said there +the playscape was in was in that + + align:start position:0% +the playscape was in was in that + + + align:start position:0% +the playscape was in was in that +actually was a classroom last year and + + align:start position:0% +actually was a classroom last year and + + + align:start position:0% +actually was a classroom last year and +it was suggested that that room be + + align:start position:0% +it was suggested that that room be + + + align:start position:0% +it was suggested that that room be +cleared out and actually be made as a + + align:start position:0% +cleared out and actually be made as a + + + align:start position:0% +cleared out and actually be made as a +central space for the community to do + + align:start position:0% +central space for the community to do + + + align:start position:0% +central space for the community to do +certain kinds of activity so the school + + align:start position:0% +certain kinds of activity so the school + + + align:start position:0% +certain kinds of activity so the school +acted on that and the idea was that the + + align:start position:0% +acted on that and the idea was that the + + + align:start position:0% +acted on that and the idea was that the +school released all the bill all the + + align:start position:0% +school released all the bill all the + + + align:start position:0% +school released all the bill all the +space on that floor for community activ + + align:start position:0% +space on that floor for community activ + + + align:start position:0% +space on that floor for community activ +ities and none of for educational + + align:start position:0% +ities and none of for educational + + + align:start position:0% +ities and none of for educational +activities from the school uh as a way + + align:start position:0% +activities from the school uh as a way + + + align:start position:0% +activities from the school uh as a way +of setting the base for and some of the + + align:start position:0% +of setting the base for and some of the + + + align:start position:0% +of setting the base for and some of the +other things they wanted to do so there + + align:start position:0% +other things they wanted to do so there + + + align:start position:0% +other things they wanted to do so there +were a number of steps that I think then + + align:start position:0% +were a number of steps that I think then + + + align:start position:0% +were a number of steps that I think then +people felt like oh well we can act on + + align:start position:0% +people felt like oh well we can act on + + + align:start position:0% +people felt like oh well we can act on +those things we can make that happen and + + align:start position:0% +those things we can make that happen and + + + align:start position:0% +those things we can make that happen and +they then kind of went on and started to + + align:start position:0% +they then kind of went on and started to + + + align:start position:0% +they then kind of went on and started to +do that so I think in the in the the way + + align:start position:0% +do that so I think in the in the the way + + + align:start position:0% +do that so I think in the in the the way +they work + + align:start position:0% +they work + + + align:start position:0% +they work +is is that they you know they really do + + align:start position:0% +is is that they you know they really do + + + align:start position:0% +is is that they you know they really do +need clear next steps and it doesn't + + align:start position:0% +need clear next steps and it doesn't + + + align:start position:0% +need clear next steps and it doesn't +matter how big or how small they are and + + align:start position:0% +matter how big or how small they are and + + + align:start position:0% +matter how big or how small they are and +then they need to be connected + + align:start position:0% +then they need to be connected + + + align:start position:0% +then they need to be connected +something much larger now I can tell you + + align:start position:0% +something much larger now I can tell you + + + align:start position:0% +something much larger now I can tell you +one of the problems we had last year + + align:start position:0% +one of the problems we had last year + + + align:start position:0% +one of the problems we had last year +which I think is a clear communication + + align:start position:0% +which I think is a clear communication + + + align:start position:0% +which I think is a clear communication +problem uh you remember the entrance + + align:start position:0% +problem uh you remember the entrance + + + align:start position:0% +problem uh you remember the entrance +into the school the + + align:start position:0% +into the school the + + + align:start position:0% +into the school the +park okay a very funny thing happened + + align:start position:0% +park okay a very funny thing happened + + + align:start position:0% +park okay a very funny thing happened +last + + align:start position:0% +last + + + align:start position:0% +last +year uh the class got together and they + + align:start position:0% +year uh the class got together and they + + + align:start position:0% +year uh the class got together and they +were trying to work on this much larger + + align:start position:0% +were trying to work on this much larger + + + align:start position:0% +were trying to work on this much larger +issue of how do you create let see if I + + align:start position:0% +issue of how do you create let see if I + + + align:start position:0% +issue of how do you create let see if I +have it here + + align:start position:0% +have it here + + + align:start position:0% +have it here +I'm not sure I do so may not have to + + align:start position:0% +I'm not sure I do so may not have to + + + align:start position:0% +I'm not sure I do so may not have to +hold anything + + align:start position:0% + + + + align:start position:0% + +up + + align:start position:0% +up + + + align:start position:0% +up +uh yeah actually I can use this + + align:start position:0% + + + + align:start position:0% + +one can you hold this up for + + align:start position:0% + + + + align:start position:0% + +me so they were worried you know the + + align:start position:0% +me so they were worried you know the + + + align:start position:0% +me so they were worried you know the +class last year was worried about this + + align:start position:0% +class last year was worried about this + + + align:start position:0% +class last year was worried about this +here's a herena school right and they + + align:start position:0% +here's a herena school right and they + + + align:start position:0% +here's a herena school right and they +were worried about this flow they were + + align:start position:0% +were worried about this flow they were + + + align:start position:0% +were worried about this flow they were +worried about how do you open up this + + align:start position:0% +worried about how do you open up this + + + align:start position:0% +worried about how do you open up this +school concept so that it really feels + + align:start position:0% +school concept so that it really feels + + + align:start position:0% +school concept so that it really feels +like it's an inviting Place coming in + + align:start position:0% +like it's an inviting Place coming in + + + align:start position:0% +like it's an inviting Place coming in +because you remember when you come down + + align:start position:0% +because you remember when you come down + + + align:start position:0% +because you remember when you come down +off the highway and you're there even + + align:start position:0% +off the highway and you're there even + + + align:start position:0% +off the highway and you're there even +now the park it does you know it's a + + align:start position:0% +now the park it does you know it's a + + + align:start position:0% +now the park it does you know it's a +park and you can't even unless you know + + align:start position:0% +park and you can't even unless you know + + + align:start position:0% +park and you can't even unless you know +there's a school there you would never + + align:start position:0% +there's a school there you would never + + + align:start position:0% +there's a school there you would never +know right unless somebody told you so + + align:start position:0% +know right unless somebody told you so + + + align:start position:0% +know right unless somebody told you so +uh one of the things that the class + + align:start position:0% +uh one of the things that the class + + + align:start position:0% +uh one of the things that the class +worked on was the design of a that space + + align:start position:0% +worked on was the design of a that space + + + align:start position:0% +worked on was the design of a that space +so that it would actually be an + + align:start position:0% +so that it would actually be an + + + align:start position:0% +so that it would actually be an +extension of Main + + align:start position:0% +extension of Main + + + align:start position:0% +extension of Main +Street right and they had a whole idea + + align:start position:0% +Street right and they had a whole idea + + + align:start position:0% +Street right and they had a whole idea +about both how push cars could be used + + align:start position:0% +about both how push cars could be used + + + align:start position:0% +about both how push cars could be used +how that one apartment building that's + + align:start position:0% +how that one apartment building that's + + + align:start position:0% +how that one apartment building that's +there could actually you could turn the + + align:start position:0% +there could actually you could turn the + + + align:start position:0% +there could actually you could turn the +first floor into a business space and + + align:start position:0% +first floor into a business space and + + + align:start position:0% +first floor into a business space and +keep apartments above it a whole kind of + + align:start position:0% +keep apartments above it a whole kind of + + + align:start position:0% +keep apartments above it a whole kind of +set of things like that + + align:start position:0% +set of things like that + + + align:start position:0% +set of things like that +unbeknownst to the class after several + + align:start position:0% +unbeknownst to the class after several + + + align:start position:0% +unbeknownst to the class after several +meetings with people the community + + align:start position:0% +meetings with people the community + + + align:start position:0% +meetings with people the community +actually had a plan that you can put + + align:start position:0% +actually had a plan that you can put + + + align:start position:0% +actually had a plan that you can put +that down had been + + align:start position:0% +that down had been + + + align:start position:0% +that down had been +developed uh two years ago three years + + align:start position:0% +developed uh two years ago three years + + + align:start position:0% +developed uh two years ago three years +ago that had been kind of + + align:start position:0% +ago that had been kind of + + + align:start position:0% +ago that had been kind of +sitting uh in a back room somewhere + + align:start position:0% +sitting uh in a back room somewhere + + + align:start position:0% +sitting uh in a back room somewhere +about redeveloping that + + align:start position:0% +about redeveloping that + + + align:start position:0% +about redeveloping that +Park okay now what you see now is + + align:start position:0% +Park okay now what you see now is + + + align:start position:0% +Park okay now what you see now is +actually the actualization of that plan + + align:start position:0% +actually the actualization of that plan + + + align:start position:0% +actually the actualization of that plan +not the one the students did right of + + align:start position:0% +not the one the students did right of + + + align:start position:0% +not the one the students did right of +the old plan because it had been on a + + align:start position:0% +the old plan because it had been on a + + + align:start position:0% +the old plan because it had been on a +track but nobody talked about it they + + align:start position:0% +track but nobody talked about it they + + + align:start position:0% +track but nobody talked about it they +would put it up and said they did show + + align:start position:0% +would put it up and said they did show + + + align:start position:0% +would put it up and said they did show +the plan said well we have these + + align:start position:0% +the plan said well we have these + + + align:start position:0% +the plan said well we have these +ideas but nobody was saying well we've + + align:start position:0% +ideas but nobody was saying well we've + + + align:start position:0% +ideas but nobody was saying well we've +got something going where this actually + + align:start position:0% +got something going where this actually + + + align:start position:0% +got something going where this actually +may happen it's actually in the parks + + align:start position:0% +may happen it's actually in the parks + + + align:start position:0% +may happen it's actually in the parks +department bud and they're starting to + + align:start position:0% +department bud and they're starting to + + + align:start position:0% +department bud and they're starting to +do something right right so the students + + align:start position:0% +do something right right so the students + + + align:start position:0% +do something right right so the students +are working on this plan and stuff and + + align:start position:0% +are working on this plan and stuff and + + + align:start position:0% +are working on this plan and stuff and +then when they came to one meeting with + + align:start position:0% +then when they came to one meeting with + + + align:start position:0% +then when they came to one meeting with +the new new North Citizens Council and + + align:start position:0% +the new new North Citizens Council and + + + align:start position:0% +the new new North Citizens Council and +they're laying out the concept of all of + + align:start position:0% +they're laying out the concept of all of + + + align:start position:0% +they're laying out the concept of all of +this and they had a whole set about what + + align:start position:0% +this and they had a whole set about what + + + align:start position:0% +this and they had a whole set about what +was going to happen on the Brightwood + + align:start position:0% +was going to happen on the Brightwood + + + align:start position:0% +was going to happen on the Brightwood +side and there was + + align:start position:0% +side and there was + + + align:start position:0% +side and there was +a there was basically a little battle + + align:start position:0% +a there was basically a little battle + + + align:start position:0% +a there was basically a little battle +that happened because the person who was + + align:start position:0% +that happened because the person who was + + + align:start position:0% +that happened because the person who was +head of the new citizen Council that + + align:start position:0% +head of the new citizen Council that + + + align:start position:0% +head of the new citizen Council that +time Barbera Rivera felt like well she + + align:start position:0% +time Barbera Rivera felt like well she + + + align:start position:0% +time Barbera Rivera felt like well she +had been dismissed because they had an + + align:start position:0% +had been dismissed because they had an + + + align:start position:0% +had been dismissed because they had an +idea and though it was + + align:start position:0% +idea and though it was + + + align:start position:0% +idea and though it was +communicated to the class as something + + align:start position:0% +communicated to the class as something + + + align:start position:0% +communicated to the class as something +they and I don't think this was + + align:start position:0% +they and I don't think this was + + + align:start position:0% +they and I don't think this was +because people were trying to set up the + + align:start position:0% +because people were trying to set up the + + + align:start position:0% +because people were trying to set up the +class I think it's because people didn't + + align:start position:0% +class I think it's because people didn't + + + align:start position:0% +class I think it's because people didn't +hold the information that way they just + + align:start position:0% +hold the information that way they just + + + align:start position:0% +hold the information that way they just +didn't hold it that way it that oh yeah + + align:start position:0% +didn't hold it that way it that oh yeah + + + align:start position:0% +didn't hold it that way it that oh yeah +there was this even and I think the + + align:start position:0% +there was this even and I think the + + + align:start position:0% +there was this even and I think the +other problem that they got caught up in + + align:start position:0% +other problem that they got caught up in + + + align:start position:0% +other problem that they got caught up in +is the person who set all that emotion + + align:start position:0% +is the person who set all that emotion + + + align:start position:0% +is the person who set all that emotion +Katie uh who's now the economic + + align:start position:0% +Katie uh who's now the economic + + + align:start position:0% +Katie uh who's now the economic +development person who was a senior + + align:start position:0% +development person who was a senior + + + align:start position:0% +development person who was a senior +planner was out on maternity to leave + + align:start position:0% +planner was out on maternity to leave + + + align:start position:0% +planner was out on maternity to leave +that whole semester so there was and the + + align:start position:0% +that whole semester so there was and the + + + align:start position:0% +that whole semester so there was and the +other person who was head of the plan + + align:start position:0% +other person who was head of the plan + + + align:start position:0% +other person who was head of the plan +Department who we would normally work + + align:start position:0% +Department who we would normally work + + + align:start position:0% +Department who we would normally work +with was actually Al CLE because she had + + align:start position:0% +with was actually Al CLE because she had + + + align:start position:0% +with was actually Al CLE because she had +cancer so the normal people who would + + align:start position:0% +cancer so the normal people who would + + + align:start position:0% +cancer so the normal people who would +have provided that information weren't + + align:start position:0% +have provided that information weren't + + + align:start position:0% +have provided that information weren't +in the picture there was no one in the + + align:start position:0% +in the picture there was no one in the + + + align:start position:0% +in the picture there was no one in the +picture who could do that connection for + + align:start position:0% +picture who could do that connection for + + + align:start position:0% +picture who could do that connection for +the class uh and I think the class what + + align:start position:0% +the class uh and I think the class what + + + align:start position:0% +the class uh and I think the class what +was interesting about it though in the + + align:start position:0% +was interesting about it though in the + + + align:start position:0% +was interesting about it though in the +public meetings that they had in the + + align:start position:0% +public meetings that they had in the + + + align:start position:0% +public meetings that they had in the +meeting with the campus committee folks + + align:start position:0% +meeting with the campus committee folks + + + align:start position:0% +meeting with the campus committee folks +wanted to do the + + align:start position:0% +wanted to do the + + + align:start position:0% +wanted to do the +plan that the students said they thought + + align:start position:0% +plan that the students said they thought + + + align:start position:0% +plan that the students said they thought +that that made sense + + align:start position:0% +that that made sense + + + align:start position:0% +that that made sense +and it could have been very easy for the + + align:start position:0% +and it could have been very easy for the + + + align:start position:0% +and it could have been very easy for the +students to have said well what's the + + align:start position:0% +students to have said well what's the + + + align:start position:0% +students to have said well what's the +transition from what you have and what's + + align:start position:0% +transition from what you have and what's + + + align:start position:0% +transition from what you have and what's +going to happen to this next stage and + + align:start position:0% +going to happen to this next stage and + + + align:start position:0% +going to happen to this next stage and +they could have built it as a + + align:start position:0% +they could have built it as a + + + align:start position:0% +they could have built it as a +transitional plan as opposed to well + + align:start position:0% +transitional plan as opposed to well + + + align:start position:0% +transitional plan as opposed to well +this is what you need to do next to + + align:start position:0% +this is what you need to do next to + + + align:start position:0% +this is what you need to do next to +clean up this area but there wasn't even + + align:start position:0% +clean up this area but there wasn't even + + + align:start position:0% +clean up this area but there wasn't even +that that that piece so there is + + align:start position:0% +that that that piece so there is + + + align:start position:0% +that that that piece so there is +some I think this important point is + + align:start position:0% +some I think this important point is + + + align:start position:0% +some I think this important point is +often you know in the politics of + + align:start position:0% +often you know in the politics of + + + align:start position:0% +often you know in the politics of +getting PL except that and acted on um + + align:start position:0% +getting PL except that and acted on um + + + align:start position:0% +getting PL except that and acted on um +understanding what people already + + align:start position:0% +understanding what people already + + + align:start position:0% +understanding what people already +invested in and sort of acknowledging at + + align:start position:0% +invested in and sort of acknowledging at + + + align:start position:0% +invested in and sort of acknowledging at +least acknowledging that and and perhaps + + align:start position:0% +least acknowledging that and and perhaps + + + align:start position:0% +least acknowledging that and and perhaps +even incorporating that you know can be + + align:start position:0% +even incorporating that you know can be + + + align:start position:0% +even incorporating that you know can be +very important because you know a lot of + + align:start position:0% +very important because you know a lot of + + + align:start position:0% +very important because you know a lot of +people will read will read the plan for + + align:start position:0% +people will read will read the plan for + + + align:start position:0% +people will read will read the plan for +where they're in it and how it + + align:start position:0% +where they're in it and how it + + + align:start position:0% +where they're in it and how it +influences resources for them and their + + align:start position:0% +influences resources for them and their + + + align:start position:0% +influences resources for them and their +organization so you know you do you have + + align:start position:0% +organization so you know you do you have + + + align:start position:0% +organization so you know you do you have +to sort of be be be conscious of that + + align:start position:0% +to sort of be be be conscious of that + + + align:start position:0% +to sort of be be be conscious of that +but I I do think in terms of of of + + align:start position:0% +but I I do think in terms of of of + + + align:start position:0% +but I I do think in terms of of of +action that um you know it's it's pretty + + align:start position:0% +action that um you know it's it's pretty + + + align:start position:0% +action that um you know it's it's pretty +much a given where our client is now + + align:start position:0% +much a given where our client is now + + + align:start position:0% +much a given where our client is now +that that um you know thinking about how + + align:start position:0% +that that um you know thinking about how + + + align:start position:0% +that that um you know thinking about how +they organize themselves to do Economic + + align:start position:0% +they organize themselves to do Economic + + + align:start position:0% +they organize themselves to do Economic +Development work and what sort of + + align:start position:0% +Development work and what sort of + + + align:start position:0% +Development work and what sort of +capacity and relationships they're going + + align:start position:0% +capacity and relationships they're going + + + align:start position:0% +capacity and relationships they're going +to need to act on you know + + align:start position:0% +to need to act on you know + + + align:start position:0% +to need to act on you know +whatever um we work with them to decide + + align:start position:0% +whatever um we work with them to decide + + + align:start position:0% +whatever um we work with them to decide +is their Economic Development agenda is + + align:start position:0% +is their Economic Development agenda is + + + align:start position:0% +is their Economic Development agenda is +going to be I think a big part of what + + align:start position:0% +going to be I think a big part of what + + + align:start position:0% +going to be I think a big part of what +we're going to be have to thinking about + + align:start position:0% +we're going to be have to thinking about + + + align:start position:0% +we're going to be have to thinking about +and and doing and so I think in that's a + + align:start position:0% +and and doing and so I think in that's a + + + align:start position:0% +and and doing and so I think in that's a +that's something once again to be + + align:start position:0% +that's something once again to be + + + align:start position:0% +that's something once again to be +thinking about as we begin to collect + + align:start position:0% +thinking about as we begin to collect + + + align:start position:0% +thinking about as we begin to collect +information you know what's important to + + align:start position:0% +information you know what's important to + + + align:start position:0% +information you know what's important to +help us plan the sort of capacity + + align:start position:0% +help us plan the sort of capacity + + + align:start position:0% +help us plan the sort of capacity +building you know the organization + + align:start position:0% +building you know the organization + + + align:start position:0% +building you know the organization +capacity building sort of aspect of of + + align:start position:0% +capacity building sort of aspect of of + + + align:start position:0% +capacity building sort of aspect of of +what what we're going to need to do + + align:start position:0% +what what we're going to need to do + + + align:start position:0% +what what we're going to need to do +because the um I guess to the extent + + align:start position:0% +because the um I guess to the extent + + + align:start position:0% +because the um I guess to the extent +Brightwood Development Corporation is + + align:start position:0% +Brightwood Development Corporation is + + + align:start position:0% +Brightwood Development Corporation is +doing something and to the extent that + + align:start position:0% +doing something and to the extent that + + + align:start position:0% +doing something and to the extent that +maybe um the Hispanic chamber is doing + + align:start position:0% +maybe um the Hispanic chamber is doing + + + align:start position:0% +maybe um the Hispanic chamber is doing +something that there there doesn't seem + + align:start position:0% +something that there there doesn't seem + + + align:start position:0% +something that there there doesn't seem +seem to be much capacity even something + + align:start position:0% +seem to be much capacity even something + + + align:start position:0% +seem to be much capacity even something +that I was sort of surprised when I + + align:start position:0% +that I was sort of surprised when I + + + align:start position:0% +that I was sort of surprised when I +asked about was well what's been done + + align:start position:0% +asked about was well what's been done + + + align:start position:0% +asked about was well what's been done +around employment programs so that the + + align:start position:0% +around employment programs so that the + + + align:start position:0% +around employment programs so that the +jobs that bait the state I mean they're + + align:start position:0% +jobs that bait the state I mean they're + + + align:start position:0% +jobs that bait the state I mean they're +just beginning to do something around + + align:start position:0% +just beginning to do something around + + + align:start position:0% +just beginning to do something around +that and that you think that would have + + align:start position:0% +that and that you think that would have + + + align:start position:0% +that and that you think that would have +been something that the employment and + + align:start position:0% +been something that the employment and + + + align:start position:0% +been something that the employment and +training the schools the employment and + + align:start position:0% +training the schools the employment and + + + align:start position:0% +training the schools the employment and +training programs and people in the city + + align:start position:0% +training programs and people in the city + + + align:start position:0% +training programs and people in the city +in the neighborhood would have been + + align:start position:0% +in the neighborhood would have been + + + align:start position:0% +in the neighborhood would have been +thinking about and working on so so I do + + align:start position:0% +thinking about and working on so so I do + + + align:start position:0% +thinking about and working on so so I do +I do think that's something you know we + + align:start position:0% +I do think that's something you know we + + + align:start position:0% +I do think that's something you know we +we should recognize it's going to be + + align:start position:0% +we should recognize it's going to be + + + align:start position:0% +we should recognize it's going to be +important important part of the the + + align:start position:0% + + + + align:start position:0% + +actions quick break yeah um sure yeah + + align:start position:0% +actions quick break yeah um sure yeah + + + align:start position:0% +actions quick break yeah um sure yeah +why don't we take a quick break then we + + align:start position:0% +why don't we take a quick break then we + + + align:start position:0% +why don't we take a quick break then we +could come back and Report out a little + + align:start position:0% +could come back and Report out a little + + + align:start position:0% +could come back and Report out a little +bit on the interviews and data + + align:start position:0% +bit on the interviews and data + + + align:start position:0% +bit on the interviews and data +collection okay and also I would like if + + align:start position:0% +collection okay and also I would like if + + + align:start position:0% +collection okay and also I would like if +somebody would take responsibility for + + align:start position:0% +somebody would take responsibility for + + + align:start position:0% +somebody would take responsibility for +like typing up those notes for the class + + align:start position:0% +like typing up those notes for the class + + + align:start position:0% +like typing up those notes for the class +under each of the categories and you can + + align:start position:0% +under each of the categories and you can + + + align:start position:0% +under each of the categories and you can +figure that out + + align:start position:0% + + + + align:start position:0% + +for like some of those procedural things + + align:start position:0% +for like some of those procedural things + + + align:start position:0% +for like some of those procedural things +outside um healthare I understand the + + align:start position:0% +outside um healthare I understand the + + + align:start position:0% +outside um healthare I understand the +definition of healthare is + + align:start position:0% +definition of healthare is + + + align:start position:0% +definition of healthare is +very well why don't we just pay + + align:start position:0% +very well why don't we just pay + + + align:start position:0% +very well why don't we just pay +attention to this this question for a + + align:start position:0% +attention to this this question for a + + + align:start position:0% +attention to this this question for a +second because I think it's an + + align:start position:0% +second because I think it's an + + + align:start position:0% +second because I think it's an +interesting one because I can give you a + + align:start position:0% +interesting one because I can give you a + + + align:start position:0% +interesting one because I can give you a +little more detail about that particular + + align:start position:0% +little more detail about that particular + + + align:start position:0% +little more detail about that particular +experience the person that they had + + align:start position:0% +experience the person that they had + + + align:start position:0% +experience the person that they had +worked a lot with last year was Michael + + align:start position:0% +worked a lot with last year was Michael + + + align:start position:0% +worked a lot with last year was Michael +Denny who's not part of neon he's + + align:start position:0% +Denny who's not part of neon he's + + + align:start position:0% +Denny who's not part of neon he's +actually with the new North Citizens + + align:start position:0% +actually with the new North Citizens + + + align:start position:0% +actually with the new North Citizens +Council he not an executive + + align:start position:0% + + + + align:start position:0% + +director he had been part of all the + + align:start position:0% +director he had been part of all the + + + align:start position:0% +director he had been part of all the +meetings with the students when they + + align:start position:0% +meetings with the students when they + + + align:start position:0% +meetings with the students when they +came back and reported and let the stuff + + align:start position:0% +came back and reported and let the stuff + + + align:start position:0% +came back and reported and let the stuff +everything like + + align:start position:0% +everything like + + + align:start position:0% +everything like +this and + + align:start position:0% + + + + align:start position:0% + +uh he had been part of that whole + + align:start position:0% +uh he had been part of that whole + + + align:start position:0% +uh he had been part of that whole +process and I think one of the things + + align:start position:0% +process and I think one of the things + + + align:start position:0% +process and I think one of the things +that came up was one of the questions + + align:start position:0% +that came up was one of the questions + + + align:start position:0% +that came up was one of the questions +that I guess the point I'm trying to + + align:start position:0% +that I guess the point I'm trying to + + + align:start position:0% +that I guess the point I'm trying to +make by that is that I don't think it's + + align:start position:0% +make by that is that I don't think it's + + + align:start position:0% +make by that is that I don't think it's +neon that really is the the issue here + + align:start position:0% +neon that really is the the issue here + + + align:start position:0% +neon that really is the the issue here +because I think you're right there are + + align:start position:0% +because I think you're right there are + + + align:start position:0% +because I think you're right there are +certain things that the neon workers are + + align:start position:0% +certain things that the neon workers are + + + align:start position:0% +certain things that the neon workers are +involved in not involved in but even + + align:start position:0% +involved in not involved in but even + + + align:start position:0% +involved in not involved in but even +when you're involved with a broader set + + align:start position:0% +when you're involved with a broader set + + + align:start position:0% +when you're involved with a broader set +of players in the community who kind of + + align:start position:0% +of players in the community who kind of + + + align:start position:0% +of players in the community who kind of +know some things and have a hold of some + + align:start position:0% +know some things and have a hold of some + + + align:start position:0% +know some things and have a hold of some +things there's a there's a question of + + align:start position:0% +things there's a there's a question of + + + align:start position:0% +things there's a there's a question of +you know how is how do people + + align:start position:0% +you know how is how do people + + + align:start position:0% +you know how is how do people +communicate what's real versus what is + + align:start position:0% +communicate what's real versus what is + + + align:start position:0% +communicate what's real versus what is +desired and sometimes those things get I + + align:start position:0% +desired and sometimes those things get I + + + align:start position:0% +desired and sometimes those things get I +think get mixed up and they were they + + align:start position:0% +think get mixed up and they were they + + + align:start position:0% +think get mixed up and they were they +were hard I think for the students to + + align:start position:0% +were hard I think for the students to + + + align:start position:0% +were hard I think for the students to +really kind of uh kind of make their way + + align:start position:0% +really kind of uh kind of make their way + + + align:start position:0% +really kind of uh kind of make their way +through I also think it's really true + + align:start position:0% +through I also think it's really true + + + align:start position:0% +through I also think it's really true +that no one in the community holds this + + align:start position:0% +that no one in the community holds this + + + align:start position:0% +that no one in the community holds this +Economic Development perspective and no + + align:start position:0% +Economic Development perspective and no + + + align:start position:0% +Economic Development perspective and no +one holds a more even though new + + align:start position:0% +one holds a more even though new + + + align:start position:0% +one holds a more even though new +Citizens + + align:start position:0% +Citizens + + + align:start position:0% +Citizens +Council has it in their purview there is + + align:start position:0% +Council has it in their purview there is + + + align:start position:0% +Council has it in their purview there is +really no agency that really have holds + + align:start position:0% +really no agency that really have holds + + + align:start position:0% +really no agency that really have holds +the kind of planning process for the + + align:start position:0% +the kind of planning process for the + + + align:start position:0% +the kind of planning process for the +neighborhood it does fall under the new + + align:start position:0% +neighborhood it does fall under the new + + + align:start position:0% +neighborhood it does fall under the new +North Citizens Council but if you kind + + align:start position:0% +North Citizens Council but if you kind + + + align:start position:0% +North Citizens Council but if you kind +of then think about the size of their + + align:start position:0% +of then think about the size of their + + + align:start position:0% +of then think about the size of their +budget and what the majority of their + + align:start position:0% +budget and what the majority of their + + + align:start position:0% +budget and what the majority of their +work is it's not around that right it's + + align:start position:0% +work is it's not around that right it's + + + align:start position:0% +work is it's not around that right it's +around something else and so I think + + align:start position:0% +around something else and so I think + + + align:start position:0% +around something else and so I think +there is a you know a little bit of a + + align:start position:0% +there is a you know a little bit of a + + + align:start position:0% +there is a you know a little bit of a +golf up between where people can put + + align:start position:0% +golf up between where people can put + + + align:start position:0% +golf up between where people can put +their attention and I think actually the + + align:start position:0% +their attention and I think actually the + + + align:start position:0% +their attention and I think actually the +folks who interview Jeff got some of + + align:start position:0% +folks who interview Jeff got some of + + + align:start position:0% +folks who interview Jeff got some of +that in the interview what I mean not + + align:start position:0% +that in the interview what I mean not + + + align:start position:0% +that in the interview what I mean not +Jeff but I mean uh Michael got some of + + align:start position:0% +Jeff but I mean uh Michael got some of + + + align:start position:0% +Jeff but I mean uh Michael got some of +that in the interview I think he was + + align:start position:0% +that in the interview I think he was + + + align:start position:0% +that in the interview I think he was +very Frank uh in the in in the interview + + align:start position:0% +very Frank uh in the in in the interview + + + align:start position:0% +very Frank uh in the in in the interview +about some of those things so Al if I + + align:start position:0% +about some of those things so Al if I + + + align:start position:0% +about some of those things so Al if I +recall I wasn't involved in the last + + align:start position:0% +recall I wasn't involved in the last + + + align:start position:0% +recall I wasn't involved in the last +year's classes but in some of the + + align:start position:0% +year's classes but in some of the + + + align:start position:0% +year's classes but in some of the +discussions you had I remember process + + align:start position:0% +discussions you had I remember process + + + align:start position:0% +discussions you had I remember process +began with a little bit of a conflict in + + align:start position:0% +began with a little bit of a conflict in + + + align:start position:0% +began with a little bit of a conflict in +agenda wasn't there the new North + + align:start position:0% +agenda wasn't there the new North + + + align:start position:0% +agenda wasn't there the new North +citizen Council had been pushing this + + align:start position:0% +citizen Council had been pushing this + + + align:start position:0% +citizen Council had been pushing this +idea of a community center yes and the + + align:start position:0% +idea of a community center yes and the + + + align:start position:0% +idea of a community center yes and the +idea of a of a campus connecting all of + + align:start position:0% +idea of a of a campus connecting all of + + + align:start position:0% +idea of a of a campus connecting all of +the other organizations was somewhat + + align:start position:0% +the other organizations was somewhat + + + align:start position:0% +the other organizations was somewhat +controversial so there were some + + align:start position:0% +controversial so there were some + + + align:start position:0% +controversial so there were some +divisions there were some division in + + align:start position:0% +divisions there were some division in + + + align:start position:0% +divisions there were some division in +the community even when the project + + align:start position:0% +the community even when the project + + + align:start position:0% +the community even when the project +started and I don't know if that played + + align:start position:0% +started and I don't know if that played + + + align:start position:0% +started and I don't know if that played +into how open some people might have + + align:start position:0% +into how open some people might have + + + align:start position:0% +into how open some people might have +been or not been you know with the + + align:start position:0% +been or not been you know with the + + + align:start position:0% +been or not been you know with the +community but but they did walk into a + + align:start position:0% +community but but they did walk into a + + + align:start position:0% +community but but they did walk into a +situation um where there were some + + align:start position:0% +situation um where there were some + + + align:start position:0% +situation um where there were some +conflicting agendas if I were to be + + align:start position:0% +conflicting agendas if I were to be + + + align:start position:0% +conflicting agendas if I were to be +going forward and so I think at least + + align:start position:0% +going forward and so I think at least + + + align:start position:0% +going forward and so I think at least +have your antennas up for that you know + + align:start position:0% +have your antennas up for that you know + + + align:start position:0% +have your antennas up for that you know +there might be segments of the community + + align:start position:0% +there might be segments of the community + + + align:start position:0% +there might be segments of the community +that think an economic development plan + + align:start position:0% +that think an economic development plan + + + align:start position:0% +that think an economic development plan +isn't what people should be working on + + align:start position:0% +isn't what people should be working on + + + align:start position:0% +isn't what people should be working on +now they might be they might feel + + align:start position:0% +now they might be they might feel + + + align:start position:0% +now they might be they might feel +dealing with vacant housing is is much + + align:start position:0% +dealing with vacant housing is is much + + + align:start position:0% +dealing with vacant housing is is much +more of an important issue or something + + align:start position:0% +more of an important issue or something + + + align:start position:0% +more of an important issue or something +like that so you know you should be you + + align:start position:0% +like that so you know you should be you + + + align:start position:0% +like that so you know you should be you +should be attentive to where there might + + align:start position:0% +should be attentive to where there might + + + align:start position:0% +should be attentive to where there might +be might the conflex of Divisions around + + align:start position:0% +be might the conflex of Divisions around + + + align:start position:0% +be might the conflex of Divisions around +the agenda you're working + + align:start position:0% +the agenda you're working + + + align:start position:0% +the agenda you're working +on why don't we um + + align:start position:0% + + + + align:start position:0% + +uh do some debriefing around the + + align:start position:0% +uh do some debriefing around the + + + align:start position:0% +uh do some debriefing around the +interviews that people had and uh who + + align:start position:0% +interviews that people had and uh who + + + align:start position:0% +interviews that people had and uh who +got to interview whom and tell us about + + align:start position:0% +got to interview whom and tell us about + + + align:start position:0% +got to interview whom and tell us about +your interview and what you learned and + + align:start position:0% +your interview and what you learned and + + + align:start position:0% +your interview and what you learned and +what you think is important for us to + + align:start position:0% + + + + align:start position:0% + +know and are there any of the teams here + + align:start position:0% +know and are there any of the teams here + + + align:start position:0% +know and are there any of the teams here +who let see who was interviewed Jeff was + + align:start position:0% +who let see who was interviewed Jeff was + + + align:start position:0% +who let see who was interviewed Jeff was +interviewed Robert Bailey was + + align:start position:0% +interviewed Robert Bailey was + + + align:start position:0% +interviewed Robert Bailey was +interviewed I guess or he spoke I'm not + + align:start position:0% +interviewed I guess or he spoke I'm not + + + align:start position:0% +interviewed I guess or he spoke I'm not +sure which one that was really + + align:start position:0% +sure which one that was really + + + align:start position:0% +sure which one that was really +interviewed he wasn't interviewed uh my + + align:start position:0% +interviewed he wasn't interviewed uh my + + + align:start position:0% +interviewed he wasn't interviewed uh my +Michael was + + align:start position:0% +Michael was + + + align:start position:0% +Michael was +interviewed Michael Denny Jeff anyone + + align:start position:0% +interviewed Michael Denny Jeff anyone + + + align:start position:0% +interviewed Michael Denny Jeff anyone +else Peter Peter Lon was interview so + + align:start position:0% +else Peter Peter Lon was interview so + + + align:start position:0% +else Peter Peter Lon was interview so +those are the three + + align:start position:0% +those are the three + + + align:start position:0% +those are the three +interviews cool so why don't we start + + align:start position:0% +interviews cool so why don't we start + + + align:start position:0% +interviews cool so why don't we start +with + + align:start position:0% +with + + + align:start position:0% +with +Peter who did Peter yeah we did okay + + align:start position:0% + + + + align:start position:0% + +actually try to suiz + + align:start position:0% +actually try to suiz + + + align:start position:0% +actually try to suiz +something I hope uh + + align:start position:0% + + + + align:start position:0% + +I think he's a principal from school + + align:start position:0% +I think he's a principal from school + + + align:start position:0% +I think he's a principal from school +sorry Phil did I give you my notes yeah + + align:start position:0% +sorry Phil did I give you my notes yeah + + + align:start position:0% +sorry Phil did I give you my notes yeah +you + + align:start position:0% +you + + + align:start position:0% +you +did yes he's the principal for + + align:start position:0% + + + + align:start position:0% + +this yeah I mean I I I didn't really + + align:start position:0% +this yeah I mean I I I didn't really + + + align:start position:0% +this yeah I mean I I I didn't really +like organize in any particular fashion + + align:start position:0% +like organize in any particular fashion + + + align:start position:0% +like organize in any particular fashion +I just kind like type up what I talk + + align:start position:0% +I just kind like type up what I talk + + + align:start position:0% +I just kind like type up what I talk +about the issues and just sort of pull + + align:start position:0% +about the issues and just sort of pull + + + align:start position:0% +about the issues and just sort of pull +up points you know is there extra one + + align:start position:0% +up points you know is there extra one + + + align:start position:0% +up points you know is there extra one +right + + align:start position:0% + + + + align:start position:0% + +we share okay okay and we can share + + align:start position:0% +we share okay okay and we can share + + + align:start position:0% +we share okay okay and we can share +we're + + align:start position:0% + + + + align:start position:0% + +fine yeah so um in the beginning one of + + align:start position:0% +fine yeah so um in the beginning one of + + + align:start position:0% +fine yeah so um in the beginning one of +the the first thing he talk about was + + align:start position:0% +the the first thing he talk about was + + + align:start position:0% +the the first thing he talk about was +just his connection with the community + + align:start position:0% +just his connection with the community + + + align:start position:0% +just his connection with the community +and he said that he's been working there + + align:start position:0% +and he said that he's been working there + + + align:start position:0% +and he said that he's been working there +um since since in + + align:start position:0% +um since since in + + + align:start position:0% +um since since in +1967 as a community activist and used to + + align:start position:0% +1967 as a community activist and used to + + + align:start position:0% +1967 as a community activist and used to +be the director for community services + + align:start position:0% +be the director for community services + + + align:start position:0% +be the director for community services +and people becoming principle he was a + + align:start position:0% +and people becoming principle he was a + + + align:start position:0% +and people becoming principle he was a +number two man for education I believe + + align:start position:0% +number two man for education I believe + + + align:start position:0% +number two man for education I believe +in spr I'm not sure of that but I think + + align:start position:0% +in spr I'm not sure of that but I think + + + align:start position:0% +in spr I'm not sure of that but I think +that's why I heard + + align:start position:0% +that's why I heard + + + align:start position:0% +that's why I heard +um and then he has been principal for + + align:start position:0% +um and then he has been principal for + + + align:start position:0% +um and then he has been principal for +four + + align:start position:0% +four + + + align:start position:0% +four +years + + align:start position:0% +years + + + align:start position:0% +years +um there was no specific order to our + + align:start position:0% +um there was no specific order to our + + + align:start position:0% +um there was no specific order to our +sort of interview just went around you + + align:start position:0% +sort of interview just went around you + + + align:start position:0% +sort of interview just went around you +know looking at issues that came up in + + align:start position:0% +know looking at issues that came up in + + + align:start position:0% +know looking at issues that came up in +our + + align:start position:0% +our + + + align:start position:0% +our +so one of the big things you talk about + + align:start position:0% +so one of the big things you talk about + + + align:start position:0% +so one of the big things you talk about +uh in the beginning was this issue of + + align:start position:0% +uh in the beginning was this issue of + + + align:start position:0% +uh in the beginning was this issue of +Housing and it was very clear from the + + align:start position:0% +Housing and it was very clear from the + + + align:start position:0% +Housing and it was very clear from the +very beginning that housing was the + + align:start position:0% +very beginning that housing was the + + + align:start position:0% +very beginning that housing was the +biggest his biggest concern uh in the + + align:start position:0% +biggest his biggest concern uh in the + + + align:start position:0% +biggest his biggest concern uh in the +beginning uh he talk about housing for + + align:start position:0% +beginning uh he talk about housing for + + + align:start position:0% +beginning uh he talk about housing for +the Ed as well and he did say um that + + align:start position:0% +the Ed as well and he did say um that + + + align:start position:0% +the Ed as well and he did say um that +from the bridal side of things the + + align:start position:0% +from the bridal side of things the + + + align:start position:0% +from the bridal side of things the +housing stock was pretty much stable and + + align:start position:0% +housing stock was pretty much stable and + + + align:start position:0% +housing stock was pretty much stable and +okay but that he felt that uh some of + + align:start position:0% +okay but that he felt that uh some of + + + align:start position:0% +okay but that he felt that uh some of +the housing on the mor Square side + + align:start position:0% +the housing on the mor Square side + + + align:start position:0% +the housing on the mor Square side +needed some attention + + align:start position:0% +needed some attention + + + align:start position:0% +needed some attention +uh in fact he they talk about some of + + align:start position:0% +uh in fact he they talk about some of + + + align:start position:0% +uh in fact he they talk about some of +those areas being completely clear out + + align:start position:0% +those areas being completely clear out + + + align:start position:0% +those areas being completely clear out +and new housing in put in + + align:start position:0% +and new housing in put in + + + align:start position:0% +and new housing in put in +there and then we talk a little bit + + align:start position:0% +there and then we talk a little bit + + + align:start position:0% +there and then we talk a little bit +about the school um and the environment + + align:start position:0% +about the school um and the environment + + + align:start position:0% +about the school um and the environment +there basically three elementary schools + + align:start position:0% +there basically three elementary schools + + + align:start position:0% +there basically three elementary schools +and one Middle School in the area and + + align:start position:0% +and one Middle School in the area and + + + align:start position:0% +and one Middle School in the area and +most high schools are in downtown the + + align:start position:0% +most high schools are in downtown the + + + align:start position:0% +most high schools are in downtown the +downtown area um the school in + + align:start position:0% +downtown area um the school in + + + align:start position:0% +downtown area um the school in +particular is mostly Hispanic and has + + align:start position:0% +particular is mostly Hispanic and has + + + align:start position:0% +particular is mostly Hispanic and has +and that group also also has the highest + + align:start position:0% +and that group also also has the highest + + + align:start position:0% +and that group also also has the highest +drug out + + align:start position:0% +drug out + + + align:start position:0% +drug out +rate um he did say that there were like + + align:start position:0% +rate um he did say that there were like + + + align:start position:0% +rate um he did say that there were like +92% free lunch introduced in the school + + align:start position:0% +92% free lunch introduced in the school + + + align:start position:0% +92% free lunch introduced in the school +uh he talk about how the school had made + + align:start position:0% +uh he talk about how the school had made + + + align:start position:0% +uh he talk about how the school had made +some progress in the last couple of in + + align:start position:0% +some progress in the last couple of in + + + align:start position:0% +some progress in the last couple of in +the last couple of years for example + + align:start position:0% +the last couple of years for example + + + align:start position:0% +the last couple of years for example +they used to place two from the bottom + + align:start position:0% +they used to place two from the bottom + + + align:start position:0% +they used to place two from the bottom +you know couple of years ago and now + + align:start position:0% +you know couple of years ago and now + + + align:start position:0% +you know couple of years ago and now +they're like 16 in math and 18 in + + align:start position:0% +they're like 16 in math and 18 in + + + align:start position:0% +they're like 16 in math and 18 in +English in massachusett + + align:start position:0% +English in massachusett + + + align:start position:0% +English in massachusett +so um just couple of curious point he + + align:start position:0% +so um just couple of curious point he + + + align:start position:0% +so um just couple of curious point he +talk about you know African-Americans is + + align:start position:0% +talk about you know African-Americans is + + + align:start position:0% +talk about you know African-Americans is +doing well incast as compared to other + + align:start position:0% +doing well incast as compared to other + + + align:start position:0% +doing well incast as compared to other +uh groups there it talks about how they + + align:start position:0% +uh groups there it talks about how they + + + align:start position:0% +uh groups there it talks about how they +were limited inage proficiency among + + align:start position:0% +were limited inage proficiency among + + + align:start position:0% +were limited inage proficiency among +students and then he also talk a lot + + align:start position:0% +students and then he also talk a lot + + + align:start position:0% +students and then he also talk a lot +about his the partnership the school had + + align:start position:0% +about his the partnership the school had + + + align:start position:0% +about his the partnership the school had +with Smith college uh which provide + + align:start position:0% +with Smith college uh which provide + + + align:start position:0% +with Smith college uh which provide +after school Tut and sports uh for the + + align:start position:0% +after school Tut and sports uh for the + + + align:start position:0% +after school Tut and sports uh for the +kids and there a couple of issue on the + + align:start position:0% +kids and there a couple of issue on the + + + align:start position:0% +kids and there a couple of issue on the +demographic um basically he talk about + + align:start position:0% +demographic um basically he talk about + + + align:start position:0% +demographic um basically he talk about +from the + + align:start position:0% +from the + + + align:start position:0% +from the +1950s how the area was set up by + + align:start position:0% +1950s how the area was set up by + + + align:start position:0% +1950s how the area was set up by +recruits from Puerto Rico for the + + align:start position:0% +recruits from Puerto Rico for the + + + align:start position:0% +recruits from Puerto Rico for the +tobacco + + align:start position:0% +tobacco + + + align:start position:0% +tobacco +Farms um and then the North End being + + align:start position:0% +Farms um and then the North End being + + + align:start position:0% +Farms um and then the North End being +the Forest + + align:start position:0% +the Forest + + + align:start position:0% +the Forest +community in the area but at the same + + align:start position:0% +community in the area but at the same + + + align:start position:0% +community in the area but at the same +time serve as a gway into the region uh + + align:start position:0% +time serve as a gway into the region uh + + + align:start position:0% +time serve as a gway into the region uh +he talk about a lot about how um + + align:start position:0% +he talk about a lot about how um + + + align:start position:0% +he talk about a lot about how um +pollution has taking place a lot in the + + align:start position:0% +pollution has taking place a lot in the + + + align:start position:0% +pollution has taking place a lot in the +area that has led to a high incidence of + + align:start position:0% +area that has led to a high incidence of + + + align:start position:0% +area that has led to a high incidence of +asthma uh we talk about new influx of + + align:start position:0% +asthma uh we talk about new influx of + + + align:start position:0% +asthma uh we talk about new influx of +immigrants from Mexico and Salvador + + align:start position:0% +immigrants from Mexico and Salvador + + + align:start position:0% +immigrants from Mexico and Salvador +Guatemala Dominican Republic in addition + + align:start position:0% +Guatemala Dominican Republic in addition + + + align:start position:0% +Guatemala Dominican Republic in addition +to + + align:start position:0% +to + + + align:start position:0% +to +the more traditional uh Puerto Rican in + + align:start position:0% +the more traditional uh Puerto Rican in + + + align:start position:0% +the more traditional uh Puerto Rican in +the + + align:start position:0% +the + + + align:start position:0% +the +community and one important thing he + + align:start position:0% +community and one important thing he + + + align:start position:0% +community and one important thing he +said was that I mean in a question I + + align:start position:0% +said was that I mean in a question I + + + align:start position:0% +said was that I mean in a question I +think it was uh James who asked a + + align:start position:0% +think it was uh James who asked a + + + align:start position:0% +think it was uh James who asked a +question or something like that + + align:start position:0% +question or something like that + + + align:start position:0% +question or something like that +concerning the political environment and + + align:start position:0% +concerning the political environment and + + + align:start position:0% +concerning the political environment and +he did say that uh there was a control + + align:start position:0% +he did say that uh there was a control + + + align:start position:0% +he did say that uh there was a control +go composed of five + + align:start position:0% +go composed of five + + + align:start position:0% +go composed of five +members and that three of those members + + align:start position:0% +members and that three of those members + + + align:start position:0% +members and that three of those members +were government appointees and they're + + align:start position:0% +were government appointees and they're + + + align:start position:0% +were government appointees and they're +particularly conservative you know state + + align:start position:0% +particularly conservative you know state + + + align:start position:0% +particularly conservative you know state +government state + + align:start position:0% +government state + + + align:start position:0% +government state +I didn't quite understand all of that + + align:start position:0% +I didn't quite understand all of that + + + align:start position:0% +I didn't quite understand all of that +but um but maybe you guys do + + align:start position:0% +but um but maybe you guys do + + + align:start position:0% +but um but maybe you guys do +anyway um and he also talk about the + + align:start position:0% +anyway um and he also talk about the + + + align:start position:0% +anyway um and he also talk about the +neighor drawing a lot of churches and + + align:start position:0% +neighor drawing a lot of churches and + + + align:start position:0% +neighor drawing a lot of churches and +Clinics uh on the health side the issues + + align:start position:0% +Clinics uh on the health side the issues + + + align:start position:0% +Clinics uh on the health side the issues +included HIV diabetes asthma and + + align:start position:0% +included HIV diabetes asthma and + + + align:start position:0% +included HIV diabetes asthma and +obesity from the employment side talk + + align:start position:0% +obesity from the employment side talk + + + align:start position:0% +obesity from the employment side talk +about B State um but he did mention that + + align:start position:0% +about B State um but he did mention that + + + align:start position:0% +about B State um but he did mention that +there was no concered effort by the + + align:start position:0% +there was no concered effort by the + + + align:start position:0% +there was no concered effort by the +community to push for job + + align:start position:0% +community to push for job + + + align:start position:0% +community to push for job +creation um and then mag workers of + + align:start position:0% +creation um and then mag workers of + + + align:start position:0% +creation um and then mag workers of +course work on farms along the colica + + align:start position:0% +course work on farms along the colica + + + align:start position:0% +course work on farms along the colica +river um terms of families you talk + + align:start position:0% +river um terms of families you talk + + + align:start position:0% +river um terms of families you talk +about how the the need + + align:start position:0% +about how the the need + + + align:start position:0% +about how the the need +for some kind of stabilization for + + align:start position:0% +for some kind of stabilization for + + + align:start position:0% +for some kind of stabilization for +families and he saw that as basically + + align:start position:0% +families and he saw that as basically + + + align:start position:0% +families and he saw that as basically +coming from the economic Foundation uh + + align:start position:0% +coming from the economic Foundation uh + + + align:start position:0% +coming from the economic Foundation uh +people getting jobs and having income to + + align:start position:0% +people getting jobs and having income to + + + align:start position:0% +people getting jobs and having income to +support their families talk a lot about + + align:start position:0% +support their families talk a lot about + + + align:start position:0% +support their families talk a lot about +broken families and how basically you + + align:start position:0% +broken families and how basically you + + + align:start position:0% +broken families and how basically you +had a situation where kids were raising + + align:start position:0% +had a situation where kids were raising + + + align:start position:0% +had a situation where kids were raising +kids + + align:start position:0% +kids + + + align:start position:0% +kids +um and + + align:start position:0% +um and + + + align:start position:0% +um and +lastly if I can just add one thing to + + align:start position:0% +lastly if I can just add one thing to + + + align:start position:0% +lastly if I can just add one thing to +that you talked a lot about adult + + align:start position:0% +that you talked a lot about adult + + + align:start position:0% +that you talked a lot about adult +literacy as well and trying to to to get + + align:start position:0% +literacy as well and trying to to to get + + + align:start position:0% +literacy as well and trying to to to get +that I + + align:start position:0% +that I + + + align:start position:0% +that I +mean kids having kids kind of if how can + + align:start position:0% +mean kids having kids kind of if how can + + + align:start position:0% +mean kids having kids kind of if how can +the kids kind of I mean based on the + + align:start position:0% +the kids kind of I mean based on the + + + align:start position:0% +the kids kind of I mean based on the +idea that how can the kids really um + + align:start position:0% +idea that how can the kids really um + + + align:start position:0% +idea that how can the kids really um +grow and learn if their parents aren't + + align:start position:0% +grow and learn if their parents aren't + + + align:start position:0% +grow and learn if their parents aren't +um don't have the capacity to help teach + + align:start position:0% +um don't have the capacity to help teach + + + align:start position:0% +um don't have the capacity to help teach +them um so they kind of teaching in the + + align:start position:0% +them um so they kind of teaching in the + + + align:start position:0% +them um so they kind of teaching in the +home thing so I think he I don't know if + + align:start position:0% +home thing so I think he I don't know if + + + align:start position:0% +home thing so I think he I don't know if +it's current or if it's a recent + + align:start position:0% +it's current or if it's a recent + + + align:start position:0% +it's current or if it's a recent +initiative but to do adult literacy in + + align:start position:0% +initiative but to do adult literacy in + + + align:start position:0% +initiative but to do adult literacy in +not only English but also in + + align:start position:0% +not only English but also in + + + align:start position:0% +not only English but also in +Spanish actually have some of that read + + align:start position:0% +Spanish actually have some of that read + + + align:start position:0% +Spanish actually have some of that read +okay sorry where you have challenges + + align:start position:0% +okay sorry where you have challenges + + + align:start position:0% +okay sorry where you have challenges +opportunities + + align:start position:0% +opportunities + + + align:start position:0% +opportunities +plans uh Peter thinks that business is a + + align:start position:0% +plans uh Peter thinks that business is a + + + align:start position:0% +plans uh Peter thinks that business is a +way to go I mean he is very strong on + + align:start position:0% +way to go I mean he is very strong on + + + align:start position:0% +way to go I mean he is very strong on +that he believes there are lots of + + align:start position:0% +that he believes there are lots of + + + align:start position:0% +that he believes there are lots of +entrepreneurs in the area for example + + align:start position:0% +entrepreneurs in the area for example + + + align:start position:0% +entrepreneurs in the area for example +talk about artist uh massage followers + + align:start position:0% +talk about artist uh massage followers + + + align:start position:0% +talk about artist uh massage followers +or viers even though most are illegal + + align:start position:0% +or viers even though most are illegal + + + align:start position:0% +or viers even though most are illegal +restaurants + + align:start position:0% +restaurants + + + align:start position:0% +restaurants +H all shops okay so when that St pet + + align:start position:0% +H all shops okay so when that St pet + + + align:start position:0% +H all shops okay so when that St pet +thinks business is the way to go yeah + + align:start position:0% +thinks business is the way to go yeah + + + align:start position:0% +thinks business is the way to go yeah +that that's helping people form + + align:start position:0% +that that's helping people form + + + align:start position:0% +that that's helping people form +businesses is is really should be a + + align:start position:0% +businesses is is really should be a + + + align:start position:0% +businesses is is really should be a +priority for any economic development + + align:start position:0% +priority for any economic development + + + align:start position:0% +priority for any economic development +plan is that sort of what you mean there + + align:start position:0% +plan is that sort of what you mean there + + + align:start position:0% +plan is that sort of what you mean there +yeah yeah + + align:start position:0% +yeah yeah + + + align:start position:0% +yeah yeah +um and then also you talk up a little + + align:start position:0% +um and then also you talk up a little + + + align:start position:0% +um and then also you talk up a little +bit about this whole idea of business + + align:start position:0% +bit about this whole idea of business + + + align:start position:0% +bit about this whole idea of business +incubation I think we you also talk + + align:start position:0% +incubation I think we you also talk + + + align:start position:0% +incubation I think we you also talk +about during the lunch time uh selecting + + align:start position:0% +about during the lunch time uh selecting + + + align:start position:0% +about during the lunch time uh selecting +or desting a place in the school for + + align:start position:0% +or desting a place in the school for + + + align:start position:0% +or desting a place in the school for +that uh so he talked about that and he + + align:start position:0% +that uh so he talked about that and he + + + align:start position:0% +that uh so he talked about that and he +felt that this whole idea will really be + + align:start position:0% +felt that this whole idea will really be + + + align:start position:0% +felt that this whole idea will really be +appealing to the three government + + align:start position:0% +appealing to the three government + + + align:start position:0% +appealing to the three government +appointees on this board that it will be + + align:start position:0% +appointees on this board that it will be + + + align:start position:0% +appointees on this board that it will be +really one way of getting them involved + + align:start position:0% +really one way of getting them involved + + + align:start position:0% +really one way of getting them involved +in the + + align:start position:0% +in the + + + align:start position:0% +in the +community + + align:start position:0% +community + + + align:start position:0% +community +um in terms of I mean one challenge you + + align:start position:0% +um in terms of I mean one challenge you + + + align:start position:0% +um in terms of I mean one challenge you +talk about was just the homeschool + + align:start position:0% +talk about was just the homeschool + + + align:start position:0% +talk about was just the homeschool +connection how do you connect the school + + align:start position:0% +connection how do you connect the school + + + align:start position:0% +connection how do you connect the school +to the home and some of the issues that + + align:start position:0% +to the home and some of the issues that + + + align:start position:0% +to the home and some of the issues that +Jim just talked about um how to engage + + align:start position:0% +Jim just talked about um how to engage + + + align:start position:0% +Jim just talked about um how to engage +the community and some ideas um he had + + align:start position:0% +the community and some ideas um he had + + + align:start position:0% +the community and some ideas um he had +was to provide um rural health care for + + align:start position:0% +was to provide um rural health care for + + + align:start position:0% +was to provide um rural health care for +students he estimated that about 90% of + + align:start position:0% +students he estimated that about 90% of + + + align:start position:0% +students he estimated that about 90% of +the students needed oral healthare and + + align:start position:0% +the students needed oral healthare and + + + align:start position:0% +the students needed oral healthare and +he also had his idea of opening the + + align:start position:0% +he also had his idea of opening the + + + align:start position:0% +he also had his idea of opening the +dental clinic for otherly people in the + + align:start position:0% +dental clinic for otherly people in the + + + align:start position:0% +dental clinic for otherly people in the +evening hours uh at + + align:start position:0% +evening hours uh at + + + align:start position:0% +evening hours uh at +school and then uh some ideas included + + align:start position:0% +school and then uh some ideas included + + + align:start position:0% +school and then uh some ideas included +providing English and Spanish literacy + + align:start position:0% +providing English and Spanish literacy + + + align:start position:0% +providing English and Spanish literacy +classes for + + align:start position:0% +classes for + + + align:start position:0% +classes for +parents uh where parents his idea was + + align:start position:0% +parents uh where parents his idea was + + + align:start position:0% +parents uh where parents his idea was +get a group of parents train them and + + align:start position:0% +get a group of parents train them and + + + align:start position:0% +get a group of parents train them and +and these parents then will be + + align:start position:0% +and these parents then will be + + + align:start position:0% +and these parents then will be +responsible to teach other + + align:start position:0% +responsible to teach other + + + align:start position:0% +responsible to teach other +parents uh and then he also talk about + + align:start position:0% +parents uh and then he also talk about + + + align:start position:0% +parents uh and then he also talk about +plans to research into how to deliver + + align:start position:0% +plans to research into how to deliver + + + align:start position:0% +plans to research into how to deliver +literacy classes for families and this + + align:start position:0% +literacy classes for families and this + + + align:start position:0% +literacy classes for families and this +would be I guess done by dis + + align:start position:0% +would be I guess done by dis + + + align:start position:0% +would be I guess done by dis +College um his idea on new was that + + align:start position:0% +College um his idea on new was that + + + align:start position:0% +College um his idea on new was that +they're very powerful and they get very + + align:start position:0% +they're very powerful and they get very + + + align:start position:0% +they're very powerful and they get very +good + + align:start position:0% +good + + + align:start position:0% +good +response he talk about State Rep living + + align:start position:0% +response he talk about State Rep living + + + align:start position:0% +response he talk about State Rep living +in the + + align:start position:0% +in the + + + align:start position:0% +in the +neighborhood and there was a very good + + align:start position:0% +neighborhood and there was a very good + + + align:start position:0% +neighborhood and there was a very good +connection to the mayor and and there're + + align:start position:0% +connection to the mayor and and there're + + + align:start position:0% +connection to the mayor and and there're +also funding for social services + + align:start position:0% +also funding for social services + + + align:start position:0% +also funding for social services +so just want to go back to one thing + + align:start position:0% +so just want to go back to one thing + + + align:start position:0% +so just want to go back to one thing +real quick do people understand what it + + align:start position:0% +real quick do people understand what it + + + align:start position:0% +real quick do people understand what it +means under the school thing it says 92% + + align:start position:0% +means under the school thing it says 92% + + + align:start position:0% +means under the school thing it says 92% +free + + align:start position:0% + + + + align:start position:0% + +lot is that clear to everyone what that + + align:start position:0% +lot is that clear to everyone what that + + + align:start position:0% +lot is that clear to everyone what that +actually means no in order in to qualify + + align:start position:0% +actually means no in order in to qualify + + + align:start position:0% +actually means no in order in to qualify +for kids to get free lunch at the school + + align:start position:0% +for kids to get free lunch at the school + + + align:start position:0% +for kids to get free lunch at the school +they basically they have to come from a + + align:start position:0% +they basically they have to come from a + + + align:start position:0% +they basically they have to come from a +family that lives within a certain + + align:start position:0% +family that lives within a certain + + + align:start position:0% +family that lives within a certain +percentage of the pover + + align:start position:0% +percentage of the pover + + + align:start position:0% +percentage of the pover +level uh set by the federal government + + align:start position:0% +level uh set by the federal government + + + align:start position:0% +level uh set by the federal government +so this is actually a measure of poverty + + align:start position:0% +so this is actually a measure of poverty + + + align:start position:0% +so this is actually a measure of poverty +of school kids who are in school that + + align:start position:0% +of school kids who are in school that + + + align:start position:0% +of school kids who are in school that +are actually + + align:start position:0% +are actually + + + align:start position:0% +are actually +living um yeah that doesn't necessarily + + align:start position:0% +living um yeah that doesn't necessarily + + + align:start position:0% +living um yeah that doesn't necessarily +represent everyone in the community + + align:start position:0% +represent everyone in the community + + + align:start position:0% +represent everyone in the community +because some people might be sending + + align:start position:0% +because some people might be sending + + + align:start position:0% +because some people might be sending +their kids to private schools or other + + align:start position:0% +their kids to private schools or other + + + align:start position:0% +their kids to private schools or other +schools but it's C it's certainly an + + align:start position:0% +schools but it's C it's certainly an + + + align:start position:0% +schools but it's C it's certainly an +indicator um any anyone else at the + + align:start position:0% +indicator um any anyone else at the + + + align:start position:0% +indicator um any anyone else at the +interview want to add anything any + + align:start position:0% +interview want to add anything any + + + align:start position:0% +interview want to add anything any +J um can I also do people understand the + + align:start position:0% +J um can I also do people understand the + + + align:start position:0% +J um can I also do people understand the +the the financial control board + + align:start position:0% +the the financial control board + + + align:start position:0% +the the financial control board +situation don't need any more + + align:start position:0% +situation don't need any more + + + align:start position:0% +situation don't need any more +clarification that okay yeah I think I + + align:start position:0% +clarification that okay yeah I think I + + + align:start position:0% +clarification that okay yeah I think I +mean just my big kind of global + + align:start position:0% +mean just my big kind of global + + + align:start position:0% +mean just my big kind of global +takeaway um was it was really you know + + align:start position:0% +takeaway um was it was really you know + + + align:start position:0% +takeaway um was it was really you know +Peter obviously has really deep roots in + + align:start position:0% +Peter obviously has really deep roots in + + + align:start position:0% +Peter obviously has really deep roots in +in the community um has been in + + align:start position:0% +in the community um has been in + + + align:start position:0% +in the community um has been in +positions you know I think you know even + + align:start position:0% +positions you know I think you know even + + + align:start position:0% +positions you know I think you know even +at lunchtime he kind of said oh yeah + + align:start position:0% +at lunchtime he kind of said oh yeah + + + align:start position:0% +at lunchtime he kind of said oh yeah +headed up the Redevelopment you know + + align:start position:0% +headed up the Redevelopment you know + + + align:start position:0% +headed up the Redevelopment you know +Authority and that didn't come out + + align:start position:0% +Authority and that didn't come out + + + align:start position:0% +Authority and that didn't come out +intervie at all um so and then you know + + align:start position:0% +intervie at all um so and then you know + + + align:start position:0% +intervie at all um so and then you know +he was talking about how you know he was + + align:start position:0% +he was talking about how you know he was + + + align:start position:0% +he was talking about how you know he was +in a construction you know had and like + + align:start position:0% +in a construction you know had and like + + + align:start position:0% +in a construction you know had and like +with this the school and build you know + + align:start position:0% +with this the school and build you know + + + align:start position:0% +with this the school and build you know +really building the school so um I think + + align:start position:0% +really building the school so um I think + + + align:start position:0% +really building the school so um I think +he feels um personally um responsible + + align:start position:0% +he feels um personally um responsible + + + align:start position:0% +he feels um personally um responsible +you know for a lot of the stuff that + + align:start position:0% +you know for a lot of the stuff that + + + align:start position:0% +you know for a lot of the stuff that +goes on um but he really did focus on + + align:start position:0% +goes on um but he really did focus on + + + align:start position:0% +goes on um but he really did focus on +the you know the small businesses and + + align:start position:0% +the you know the small businesses and + + + align:start position:0% +the you know the small businesses and +the entrepreneurship microenterprises + + align:start position:0% +the entrepreneurship microenterprises + + + align:start position:0% +the entrepreneurship microenterprises +the the kind of way way to go in the + + align:start position:0% +the the kind of way way to go in the + + + align:start position:0% +the the kind of way way to go in the +neighborhood so that was that was really + + align:start position:0% +neighborhood so that was that was really + + + align:start position:0% +neighborhood so that was that was really +his very clear uh + + align:start position:0% +his very clear uh + + + align:start position:0% +his very clear uh +agenda you're going to ask a question + + align:start position:0% +agenda you're going to ask a question + + + align:start position:0% +agenda you're going to ask a question +yeah I have a question about absente + + align:start position:0% +yeah I have a question about absente + + + align:start position:0% +yeah I have a question about absente +landlords did he say who are these and + + align:start position:0% +landlords did he say who are these and + + + align:start position:0% +landlords did he say who are these and +where are + + align:start position:0% + + + + align:start position:0% + +they I know he did talk a little bit + + align:start position:0% +they I know he did talk a little bit + + + align:start position:0% +they I know he did talk a little bit +about people living I think in Bost or + + align:start position:0% +about people living I think in Bost or + + + align:start position:0% +about people living I think in Bost or +something only properties there or + + align:start position:0% +something only properties there or + + + align:start position:0% +something only properties there or +something like + + align:start position:0% + + + + align:start position:0% + +that I interview Michael that that AOW + + align:start position:0% +that I interview Michael that that AOW + + + align:start position:0% +that I interview Michael that that AOW +theost + + align:start position:0% + + + + align:start position:0% + +juster so is it investment just to the + + align:start position:0% +juster so is it investment just to the + + + align:start position:0% +juster so is it investment just to the +prop few years + + align:start position:0% +prop few years + + + align:start position:0% +prop few years +or yeah how did Michael talk about that + + align:start position:0% +or yeah how did Michael talk about that + + + align:start position:0% +or yeah how did Michael talk about that +I mean he he did talk about that + + align:start position:0% +I mean he he did talk about that + + + align:start position:0% +I mean he he did talk about that +specifically about what they were doing + + align:start position:0% +specifically about what they were doing + + + align:start position:0% +specifically about what they were doing +yeah I mean basically like you can get + + align:start position:0% +yeah I mean basically like you can get + + + align:start position:0% +yeah I mean basically like you can get +you know it's the some of the cheapest + + align:start position:0% +you know it's the some of the cheapest + + + align:start position:0% +you know it's the some of the cheapest +property you can get in in Massachusetts + + align:start position:0% +property you can get in in Massachusetts + + + align:start position:0% +property you can get in in Massachusetts +and you can buy house for 100 or under + + align:start position:0% +and you can buy house for 100 or under + + + align:start position:0% +and you can buy house for 100 or under +Grand and there's buying they just + + align:start position:0% +Grand and there's buying they just + + + align:start position:0% +Grand and there's buying they just +letting housing interior + + align:start position:0% +letting housing interior + + + align:start position:0% +letting housing interior +um and there was like lots of turnover + + align:start position:0% +um and there was like lots of turnover + + + align:start position:0% +um and there was like lots of turnover +um you know + + align:start position:0% +um you know + + + align:start position:0% +um you know +people the house not well maintain at + + align:start position:0% +people the house not well maintain at + + + align:start position:0% +people the house not well maintain at +all been a huge problem I me there's + + align:start position:0% +all been a huge problem I me there's + + + align:start position:0% +all been a huge problem I me there's +probably a lot of money pour out of + + align:start position:0% +probably a lot of money pour out of + + + align:start position:0% +probably a lot of money pour out of +Boston because if you look at the + + align:start position:0% +Boston because if you look at the + + + align:start position:0% +Boston because if you look at the +situation of Boston right now you have + + align:start position:0% +situation of Boston right now you have + + + align:start position:0% +situation of Boston right now you have +there's been this huge run up in + + align:start position:0% +there's been this huge run up in + + + align:start position:0% +there's been this huge run up in +property values and there's a + + align:start position:0% +property values and there's a + + + align:start position:0% +property values and there's a +disjunction between the + + align:start position:0% +disjunction between the + + + align:start position:0% +disjunction between the +property the value the property is sell + + align:start position:0% +property the value the property is sell + + + align:start position:0% +property the value the property is sell +for and the rents that properties is are + + align:start position:0% +for and the rents that properties is are + + + align:start position:0% +for and the rents that properties is are +earning you can't really support a unit + + align:start position:0% +earning you can't really support a unit + + + align:start position:0% +earning you can't really support a unit +based on the rents the right now because + + align:start position:0% +based on the rents the right now because + + + align:start position:0% +based on the rents the right now because +properties have gone up so you may well + + align:start position:0% +properties have gone up so you may well + + + align:start position:0% +properties have gone up so you may well +see Property Owners saying H you know if + + align:start position:0% +see Property Owners saying H you know if + + + align:start position:0% +see Property Owners saying H you know if +I take my money out of Boston I'm gonna + + align:start position:0% +I take my money out of Boston I'm gonna + + + align:start position:0% +I take my money out of Boston I'm gonna +make a lot of money on this investment + + align:start position:0% +make a lot of money on this investment + + + align:start position:0% +make a lot of money on this investment +now and I can move into a market where + + align:start position:0% +now and I can move into a market where + + + align:start position:0% +now and I can move into a market where +values are lower and the rents will cash + + align:start position:0% +values are lower and the rents will cash + + + align:start position:0% +values are lower and the rents will cash +flow better for me so it doesn't surp + + align:start position:0% +flow better for me so it doesn't surp + + + align:start position:0% +flow better for me so it doesn't surp +it's sort of like Arbitrage in the state + + align:start position:0% +it's sort of like Arbitrage in the state + + + align:start position:0% +it's sort of like Arbitrage in the state +you know you have a very expensive + + align:start position:0% +you know you have a very expensive + + + align:start position:0% +you know you have a very expensive +housing market and a lost housing market + + align:start position:0% +housing market and a lost housing market + + + align:start position:0% +housing market and a lost housing market +and people are shifting some of their + + align:start position:0% +and people are shifting some of their + + + align:start position:0% +and people are shifting some of their +investment dollars to capitalize on that + + align:start position:0% +investment dollars to capitalize on that + + + align:start position:0% +investment dollars to capitalize on that +wouldn't surprise me at + + align:start position:0% +wouldn't surprise me at + + + align:start position:0% +wouldn't surprise me at +all + + align:start position:0% +all + + + align:start position:0% +all +great good + + align:start position:0% +great good + + + align:start position:0% +great good +job + + align:start position:0% +job + + + align:start position:0% +job +good um who else going + + align:start position:0% + + + + align:start position:0% + +ask + + align:start position:0% +ask + + + align:start position:0% +ask +okay so SE I + + align:start position:0% +okay so SE I + + + align:start position:0% +okay so SE I +interviewed head of the new Citizens + + align:start position:0% +interviewed head of the new Citizens + + + align:start position:0% +interviewed head of the new Citizens +Council he had a lot to + + align:start position:0% +Council he had a lot to + + + align:start position:0% +Council he had a lot to +say anyone not have a lot to + + align:start position:0% +say anyone not have a lot to + + + align:start position:0% +say anyone not have a lot to +that's problem I I I think our initial + + align:start position:0% +that's problem I I I think our initial + + + align:start position:0% +that's problem I I I think our initial +question was answered within like 40 + + align:start position:0% +question was answered within like 40 + + + align:start position:0% +question was answered within like 40 +minutes um but he he was really good he + + align:start position:0% +minutes um but he he was really good he + + + align:start position:0% +minutes um but he he was really good he +just like real information um some of + + align:start position:0% +just like real information um some of + + + align:start position:0% +just like real information um some of +the + + align:start position:0% +the + + + align:start position:0% +the +highlights basic so new North he really + + align:start position:0% +highlights basic so new North he really + + + align:start position:0% +highlights basic so new North he really +emphasized kind of Social Service + + align:start position:0% +emphasized kind of Social Service + + + align:start position:0% +emphasized kind of Social Service +aspects of what they do and there was + + align:start position:0% +aspects of what they do and there was + + + align:start position:0% +aspects of what they do and there was +kind point about how how much of a + + align:start position:0% +kind point about how how much of a + + + align:start position:0% +kind point about how how much of a +planning organization are they um like + + align:start position:0% +planning organization are they um like + + + align:start position:0% +planning organization are they um like +with key and actually another worker + + align:start position:0% +with key and actually another worker + + + align:start position:0% +with key and actually another worker +there Maria sat in us on the interview + + align:start position:0% +there Maria sat in us on the interview + + + align:start position:0% +there Maria sat in us on the interview +and she was showing us their uh kind of + + align:start position:0% +and she was showing us their uh kind of + + + align:start position:0% +and she was showing us their uh kind of +like the their scope of work their + + align:start position:0% +like the their scope of work their + + + align:start position:0% +like the their scope of work their +mission work as an organization and so + + align:start position:0% +mission work as an organization and so + + + align:start position:0% +mission work as an organization and so +much of it was Social Service based so + + align:start position:0% +much of it was Social Service based so + + + align:start position:0% +much of it was Social Service based so +they do like all sorts of like Child + + align:start position:0% +they do like all sorts of like Child + + + align:start position:0% +they do like all sorts of like Child +Care parenting issues family um tutoring + + align:start position:0% +Care parenting issues family um tutoring + + + align:start position:0% +Care parenting issues family um tutoring +job + + align:start position:0% +job + + + align:start position:0% +job +placement uh advocacy around Youth and + + align:start position:0% +placement uh advocacy around Youth and + + + align:start position:0% +placement uh advocacy around Youth and +family issues + + align:start position:0% +family issues + + + align:start position:0% +family issues +Healthcare um they do resource and + + align:start position:0% +Healthcare um they do resource and + + + align:start position:0% +Healthcare um they do resource and +referrals substance abuse programs HIV + + align:start position:0% +referrals substance abuse programs HIV + + + align:start position:0% +referrals substance abuse programs HIV +Aid prevention educ and + + align:start position:0% +Aid prevention educ and + + + align:start position:0% +Aid prevention educ and +education um school programs anyway like + + align:start position:0% +education um school programs anyway like + + + align:start position:0% +education um school programs anyway like +if for for a good like 10 minutes you + + align:start position:0% +if for for a good like 10 minutes you + + + align:start position:0% +if for for a good like 10 minutes you +wouldn't know that they actually do + + align:start position:0% +wouldn't know that they actually do + + + align:start position:0% +wouldn't know that they actually do +planning as well or do development or + + align:start position:0% +planning as well or do development or + + + align:start position:0% +planning as well or do development or +you know are the main um you know kind + + align:start position:0% +you know are the main um you know kind + + + align:start position:0% +you know are the main um you know kind +of yes or no on a lot of development + + align:start position:0% +of yes or no on a lot of development + + + align:start position:0% +of yes or no on a lot of development +projects in in the North End um so + + align:start position:0% +projects in in the North End um so + + + align:start position:0% +projects in in the North End um so +that's kind of a big issue that there's + + align:start position:0% +that's kind of a big issue that there's + + + align:start position:0% +that's kind of a big issue that there's +all this other activities going on + + align:start position:0% +all this other activities going on + + + align:start position:0% +all this other activities going on +within the + + align:start position:0% +within the + + + align:start position:0% +within the +organization um they so as I think + + align:start position:0% +organization um they so as I think + + + align:start position:0% +organization um they so as I think +described previously it's I'm not + + align:start position:0% +described previously it's I'm not + + + align:start position:0% +described previously it's I'm not +completely clear but the mechanism is + + align:start position:0% +completely clear but the mechanism is + + + align:start position:0% +completely clear but the mechanism is +that they have um any any new + + align:start position:0% +that they have um any any new + + + align:start position:0% +that they have um any any new +development goes through them so they + + align:start position:0% +development goes through them so they + + + align:start position:0% +development goes through them so they +have pretty much if not not official but + + align:start position:0% +have pretty much if not not official but + + + align:start position:0% +have pretty much if not not official but +they have a de facto um decision making + + align:start position:0% +they have a de facto um decision making + + + align:start position:0% +they have a de facto um decision making +role in development that happens um in + + align:start position:0% +role in development that happens um in + + + align:start position:0% +role in development that happens um in +the North End so are definitely the key + + align:start position:0% +the North End so are definitely the key + + + align:start position:0% +the North End so are definitely the key +player and they have the the city's ear + + align:start position:0% +player and they have the the city's ear + + + align:start position:0% +player and they have the the city's ear +when it comes to new + + align:start position:0% +when it comes to new + + + align:start position:0% +when it comes to new +projects tough a lot about again like + + align:start position:0% +projects tough a lot about again like + + + align:start position:0% +projects tough a lot about again like +abute landlords and the housing and how + + align:start position:0% +abute landlords and the housing and how + + + align:start position:0% +abute landlords and the housing and how +that's a big problem um but again show + + align:start position:0% +that's a big problem um but again show + + + align:start position:0% +that's a big problem um but again show +like the Memorial square and briwood and + + align:start position:0% +like the Memorial square and briwood and + + + align:start position:0% +like the Memorial square and briwood and +how like you know the how stock Memorial + + align:start position:0% +how like you know the how stock Memorial + + + align:start position:0% +how like you know the how stock Memorial +square is not really what briwood is he + + align:start position:0% +square is not really what briwood is he + + + align:start position:0% +square is not really what briwood is he +said he lives in Brightwood yeah he + + align:start position:0% +said he lives in Brightwood yeah he + + + align:start position:0% +said he lives in Brightwood yeah he +lives in Brightwood he's been there + + align:start position:0% +lives in Brightwood he's been there + + + align:start position:0% +lives in Brightwood he's been there +for several years 20 years or something + + align:start position:0% +for several years 20 years or something + + + align:start position:0% +for several years 20 years or something +and uh he justes you totally different + + align:start position:0% +and uh he justes you totally different + + + align:start position:0% +and uh he justes you totally different +place thanal + + align:start position:0% +place thanal + + + align:start position:0% +place thanal +Square uh new North is actually one of + + align:start position:0% +Square uh new North is actually one of + + + align:start position:0% +Square uh new North is actually one of +the largest employers in the + + align:start position:0% +the largest employers in the + + + align:start position:0% +the largest employers in the +north um we do with that + + align:start position:0% + + + + align:start position:0% + +but how many did + + align:start position:0% + + + + align:start position:0% + +say uh one of a couple of like successes + + align:start position:0% +say uh one of a couple of like successes + + + align:start position:0% +say uh one of a couple of like successes +he he pointed out that they've done one + + align:start position:0% +he he pointed out that they've done one + + + align:start position:0% +he he pointed out that they've done one +that was interesting that they turned a + + align:start position:0% +that was interesting that they turned a + + + align:start position:0% +that was interesting that they turned a +liquor store on Main Street into a child + + align:start position:0% +liquor store on Main Street into a child + + + align:start position:0% +liquor store on Main Street into a child +care center + + align:start position:0% + + + + align:start position:0% + +um ecomic is development + + align:start position:0% +um ecomic is development + + + align:start position:0% +um ecomic is development +issues he points it out some of the same + + align:start position:0% +issues he points it out some of the same + + + align:start position:0% +issues he points it out some of the same +on been talking about limited skills + + align:start position:0% +on been talking about limited skills + + + align:start position:0% +on been talking about limited skills +education language issues um kind of + + align:start position:0% +education language issues um kind of + + + align:start position:0% +education language issues um kind of +like anywhere can be better on subsidies + + align:start position:0% +like anywhere can be better on subsidies + + + align:start position:0% +like anywhere can be better on subsidies +than they can be by working get the type + + align:start position:0% +than they can be by working get the type + + + align:start position:0% +than they can be by working get the type +of jobs that are available then another + + align:start position:0% +of jobs that are available then another + + + align:start position:0% +of jobs that are available then another +interesting thing is + + align:start position:0% +interesting thing is + + + align:start position:0% +interesting thing is +that initial development reports read is + + align:start position:0% + + + + align:start position:0% + +that tool group with the largest + + align:start position:0% +that tool group with the largest + + + align:start position:0% +that tool group with the largest +employer + + align:start position:0% +employer + + + align:start position:0% +employer +in + + align:start position:0% +in + + + align:start position:0% +in +right rightwood they left so they're no + + align:start position:0% +right rightwood they left so they're no + + + align:start position:0% +right rightwood they left so they're no +longer in the North End so that's that's + + align:start position:0% +longer in the North End so that's that's + + + align:start position:0% +longer in the North End so that's that's +a major potential issue that + + align:start position:0% +a major potential issue that + + + align:start position:0% +a major potential issue that +um employers gone uh we talked a little + + align:start position:0% +um employers gone uh we talked a little + + + align:start position:0% +um employers gone uh we talked a little +bit about crime and safety on crime + + align:start position:0% +bit about crime and safety on crime + + + align:start position:0% +bit about crime and safety on crime +perceptions from of of crime and safety + + align:start position:0% +perceptions from of of crime and safety + + + align:start position:0% +perceptions from of of crime and safety +um and he thought that the perception + + align:start position:0% +um and he thought that the perception + + + align:start position:0% +um and he thought that the perception +isn't completely match with reality he + + align:start position:0% +isn't completely match with reality he + + + align:start position:0% +isn't completely match with reality he +thought that um it actually as as was a + + align:start position:0% +thought that um it actually as as was a + + + align:start position:0% +thought that um it actually as as was a +lot more safe was a lot safer than the + + align:start position:0% +lot more safe was a lot safer than the + + + align:start position:0% +lot more safe was a lot safer than the +people may make it out to + + align:start position:0% +people may make it out to + + + align:start position:0% +people may make it out to +be that's a lot about their relationship + + align:start position:0% +be that's a lot about their relationship + + + align:start position:0% +be that's a lot about their relationship +with B state which is interesting he + + align:start position:0% +with B state which is interesting he + + + align:start position:0% +with B state which is interesting he +said really adversarial for + + align:start position:0% +said really adversarial for + + + align:start position:0% +said really adversarial for +forever I guess um but that in the past + + align:start position:0% +forever I guess um but that in the past + + + align:start position:0% +forever I guess um but that in the past +like two to three years it's it's been + + align:start position:0% +like two to three years it's it's been + + + align:start position:0% +like two to three years it's it's been +improving significantly uh he thought + + align:start position:0% +improving significantly uh he thought + + + align:start position:0% +improving significantly uh he thought +that pretty much had to the change + + align:start position:0% +that pretty much had to the change + + + align:start position:0% +that pretty much had to the change +leadership um + + align:start position:0% +leadership um + + + align:start position:0% +leadership um +and there was + + align:start position:0% +and there was + + + align:start position:0% +and there was +a there was something that + + align:start position:0% +a there was something that + + + align:start position:0% +a there was something that +brought there something that brought + + align:start position:0% +brought there something that brought + + + align:start position:0% +brought there something that brought +them together they did um basic needed + + align:start position:0% +them together they did um basic needed + + + align:start position:0% +them together they did um basic needed +something from from + + align:start position:0% +something from from + + + align:start position:0% +something from from +new said point being that Rel are to new + + align:start position:0% +new said point being that Rel are to new + + + align:start position:0% +new said point being that Rel are to new +North that they St + + align:start position:0% + + + + align:start position:0% + +um he he he deped Bas St is pretty much + + align:start position:0% +um he he he deped Bas St is pretty much + + + align:start position:0% +um he he he deped Bas St is pretty much +like it should in land and property + + align:start position:0% +like it should in land and property + + + align:start position:0% +like it should in land and property +money um not necessarily a good + + align:start position:0% +money um not necessarily a good + + + align:start position:0% +money um not necessarily a good +Community partner but again that's that + + align:start position:0% +Community partner but again that's that + + + align:start position:0% +Community partner but again that's that +been improving over the past + + align:start position:0% +been improving over the past + + + align:start position:0% +been improving over the past +years uh they don't employ locally which + + align:start position:0% +years uh they don't employ locally which + + + align:start position:0% +years uh they don't employ locally which +is a big problem um as you know that it + + align:start position:0% +is a big problem um as you know that it + + + align:start position:0% +is a big problem um as you know that it +also has to do with the skills though + + align:start position:0% +also has to do with the skills though + + + align:start position:0% +also has to do with the skills though +exist in the community for the type of + + align:start position:0% +exist in the community for the type of + + + align:start position:0% +exist in the community for the type of +jobs that b is looking for at least good + + align:start position:0% +jobs that b is looking for at least good + + + align:start position:0% +jobs that b is looking for at least good +type of + + align:start position:0% +type of + + + align:start position:0% +type of +jobs um but so one one of the indicators + + align:start position:0% +jobs um but so one one of the indicators + + + align:start position:0% +jobs um but so one one of the indicators +that things are kind of changing is that + + align:start position:0% +that things are kind of changing is that + + + align:start position:0% +that things are kind of changing is that +Bas I'm working with to the link and one + + align:start position:0% +Bas I'm working with to the link and one + + + align:start position:0% +Bas I'm working with to the link and one +of the high schools on training programs + + align:start position:0% +of the high schools on training programs + + + align:start position:0% +of the high schools on training programs +so like we want to see continue was + + align:start position:0% +so like we want to see continue was + + + align:start position:0% +so like we want to see continue was +linking base data with the schools for + + align:start position:0% +linking base data with the schools for + + + align:start position:0% +linking base data with the schools for +um unification schools for real job + + align:start position:0% +um unification schools for real job + + + align:start position:0% +um unification schools for real job +training that would prepare High States + + align:start position:0% +training that would prepare High States + + + align:start position:0% +training that would prepare High States +for aate type + + align:start position:0% + + + + align:start position:0% + +jobs oh this is sorry this is the issue + + align:start position:0% +jobs oh this is sorry this is the issue + + + align:start position:0% +jobs oh this is sorry this is the issue +from is that they're landlocked so they + + align:start position:0% +from is that they're landlocked so they + + + align:start position:0% +from is that they're landlocked so they +don't have any way to expand directly + + align:start position:0% +don't have any way to expand directly + + + align:start position:0% +don't have any way to expand directly +around them so that they in his View at + + align:start position:0% +around them so that they in his View at + + + align:start position:0% +around them so that they in his View at +least they're BEC playing more + + align:start position:0% +least they're BEC playing more + + + align:start position:0% +least they're BEC playing more +interested in the neighborhood as a + + align:start position:0% +interested in the neighborhood as a + + + align:start position:0% +interested in the neighborhood as a +whole to offer them more opportunities + + align:start position:0% +whole to offer them more opportunities + + + align:start position:0% +whole to offer them more opportunities +for expansion because they pretty much + + align:start position:0% +for expansion because they pretty much + + + align:start position:0% +for expansion because they pretty much +take expanded everywhere they can in + + align:start position:0% +take expanded everywhere they can in + + + align:start position:0% +take expanded everywhere they can in +their you know directly around their + + align:start position:0% +their you know directly around their + + + align:start position:0% +their you know directly around their +existing + + align:start position:0% +existing + + + align:start position:0% +existing +property uh another interesting thing is + + align:start position:0% +property uh another interesting thing is + + + align:start position:0% +property uh another interesting thing is +he talks about the private Development + + align:start position:0% +he talks about the private Development + + + align:start position:0% +he talks about the private Development +Corporation how it's changed um and how + + align:start position:0% +Corporation how it's changed um and how + + + align:start position:0% +Corporation how it's changed um and how +it really was like a strong CBC in the + + align:start position:0% +it really was like a strong CBC in the + + + align:start position:0% +it really was like a strong CBC in the +neighborhood and now um I guess + + align:start position:0% +neighborhood and now um I guess + + + align:start position:0% +neighborhood and now um I guess +I guess their new leadership or at some + + align:start position:0% +I guess their new leadership or at some + + + align:start position:0% +I guess their new leadership or at some +point where existing leadership kind of + + align:start position:0% +point where existing leadership kind of + + + align:start position:0% +point where existing leadership kind of +changed and they're just completely you + + align:start position:0% +changed and they're just completely you + + + align:start position:0% +changed and they're just completely you +know not interested in the neigh or + + align:start position:0% +know not interested in the neigh or + + + align:start position:0% +know not interested in the neigh or +don't AR are not seen as a good + + align:start position:0% +don't AR are not seen as a good + + + align:start position:0% +don't AR are not seen as a good +Community Builder um but now their + + align:start position:0% +Community Builder um but now their + + + align:start position:0% +Community Builder um but now their +interests are a lot work outside + + align:start position:0% +interests are a lot work outside + + + align:start position:0% +interests are a lot work outside +Springfield so they're doing a lot of + + align:start position:0% +Springfield so they're doing a lot of + + + align:start position:0% +Springfield so they're doing a lot of +development work where either outside + + align:start position:0% +development work where either outside + + + align:start position:0% +development work where either outside +the North End or outside Springfield as + + align:start position:0% +the North End or outside Springfield as + + + align:start position:0% +the North End or outside Springfield as +well in other parts of Massachusetts and + + align:start position:0% +well in other parts of Massachusetts and + + + align:start position:0% +well in other parts of Massachusetts and +it seems like the impression is that + + align:start position:0% +it seems like the impression is that + + + align:start position:0% +it seems like the impression is that +they gotten kind of like too big and no + + align:start position:0% +they gotten kind of like too big and no + + + align:start position:0% +they gotten kind of like too big and no +longer as interested in + + align:start position:0% +longer as interested in + + + align:start position:0% +longer as interested in +north um so he really really stressed + + align:start position:0% +north um so he really really stressed + + + align:start position:0% +north um so he really really stressed +that the north needs a strong CDC and he + + align:start position:0% +that the north needs a strong CDC and he + + + align:start position:0% +that the north needs a strong CDC and he +was thr about this idea that the north + + align:start position:0% +was thr about this idea that the north + + + align:start position:0% +was thr about this idea that the north +the new North his organization could + + align:start position:0% +the new North his organization could + + + align:start position:0% +the new North his organization could +play that role um as + + align:start position:0% +play that role um as + + + align:start position:0% +play that role um as +developer um and soar about that or is + + align:start position:0% +developer um and soar about that or is + + + align:start position:0% +developer um and soar about that or is +is there need to be like a founding of a + + align:start position:0% +is there need to be like a founding of a + + + align:start position:0% +is there need to be like a founding of a +new CBC clear that was a huge + + align:start position:0% + + + + align:start position:0% + +need + + align:start position:0% +need + + + align:start position:0% +need +uh um and we had we as some kind like + + align:start position:0% +uh um and we had we as some kind like + + + align:start position:0% +uh um and we had we as some kind like +what if you you you're doing plan what + + align:start position:0% +what if you you you're doing plan what + + + align:start position:0% +what if you you you're doing plan what +you priorities you we talk about those + + align:start position:0% +you priorities you we talk about those + + + align:start position:0% +you priorities you we talk about those +kind of bigger issues but I mean he he + + align:start position:0% +kind of bigger issues but I mean he he + + + align:start position:0% +kind of bigger issues but I mean he he +would asked that question directly he + + align:start position:0% +would asked that question directly he + + + align:start position:0% +would asked that question directly he +said he doesn't really know um but some + + align:start position:0% +said he doesn't really know um but some + + + align:start position:0% +said he doesn't really know um but some +of the things he pointed out were just + + align:start position:0% +of the things he pointed out were just + + + align:start position:0% +of the things he pointed out were just +you know no destination shopping so + + align:start position:0% +you know no destination shopping so + + + align:start position:0% +you know no destination shopping so +nothing floring people from the outside + + align:start position:0% +nothing floring people from the outside + + + align:start position:0% +nothing floring people from the outside +in um not even enough convenience + + align:start position:0% +in um not even enough convenience + + + align:start position:0% +in um not even enough convenience +shopping so there's not like drugs for + + align:start position:0% +shopping so there's not like drugs for + + + align:start position:0% +shopping so there's not like drugs for +dry cleaners um it's not like the kind + + align:start position:0% +dry cleaners um it's not like the kind + + + align:start position:0% +dry cleaners um it's not like the kind +of diversity of commun some + + align:start position:0% +of diversity of commun some + + + align:start position:0% +of diversity of commun some +uh we asked a bit about that and he + + align:start position:0% +uh we asked a bit about that and he + + + align:start position:0% +uh we asked a bit about that and he +thought just kind as we've discussed + + align:start position:0% +thought just kind as we've discussed + + + align:start position:0% +thought just kind as we've discussed +before that um people kind of don't know + + align:start position:0% +before that um people kind of don't know + + + align:start position:0% +before that um people kind of don't know +what else to do so they start local + + align:start position:0% +what else to do so they start local + + + align:start position:0% +what else to do so they start local +business and they don't know what other + + align:start position:0% +business and they don't know what other + + + align:start position:0% +business and they don't know what other +local business starts they do with + + align:start position:0% +local business starts they do with + + + align:start position:0% +local business starts they do with +Bodega um and that's not necessarily + + align:start position:0% +Bodega um and that's not necessarily + + + align:start position:0% +Bodega um and that's not necessarily +obviously the best thing uh he did talk + + align:start position:0% +obviously the best thing uh he did talk + + + align:start position:0% +obviously the best thing uh he did talk +about how there's this opportunity to + + align:start position:0% +about how there's this opportunity to + + + align:start position:0% +about how there's this opportunity to +build around kind of like the E thing + + align:start position:0% +build around kind of like the E thing + + + align:start position:0% +build around kind of like the E thing +where um um emphasis of the nor event + + align:start position:0% +where um um emphasis of the nor event + + + align:start position:0% +where um um emphasis of the nor event +and he thought that that was an + + align:start position:0% +and he thought that that was an + + + align:start position:0% +and he thought that that was an +opportunity that might people um from + + align:start position:0% +opportunity that might people um from + + + align:start position:0% +opportunity that might people um from +the + + align:start position:0% +the + + + align:start position:0% +the +outside we know about um yeah so a + + align:start position:0% +outside we know about um yeah so a + + + align:start position:0% +outside we know about um yeah so a +marketing packaging issue of branding + + align:start position:0% +marketing packaging issue of branding + + + align:start position:0% +marketing packaging issue of branding +like the new North and again like I I + + align:start position:0% +like the new North and again like I I + + + align:start position:0% +like the new North and again like I I +think he recognize the potential + + align:start position:0% +think he recognize the potential + + + align:start position:0% +think he recognize the potential +pitfalls of that but just saw that that + + align:start position:0% +pitfalls of that but just saw that that + + + align:start position:0% +pitfalls of that but just saw that that +was an opportunity that that would might + + align:start position:0% +was an opportunity that that would might + + + align:start position:0% +was an opportunity that that would might +distinguish the North End from other + + align:start position:0% +distinguish the North End from other + + + align:start position:0% +distinguish the North End from other +parts of + + align:start position:0% + + + + align:start position:0% + +Springfield also I think notic that b + + align:start position:0% +Springfield also I think notic that b + + + align:start position:0% +Springfield also I think notic that b +this but something that was he know he + + align:start position:0% +this but something that was he know he + + + align:start position:0% +this but something that was he know he +noted was that in the past like four or + + align:start position:0% +noted was that in the past like four or + + + align:start position:0% +noted was that in the past like four or +five years there been a real influx of + + align:start position:0% +five years there been a real influx of + + + align:start position:0% +five years there been a real influx of +um of immigrants from guala salor Mexico + + align:start position:0% +um of immigrants from guala salor Mexico + + + align:start position:0% +um of immigrants from guala salor Mexico +and that so while the neighbor is + + align:start position:0% +and that so while the neighbor is + + + align:start position:0% +and that so while the neighbor is +definitely probably Puerto Rican is that + + align:start position:0% +definitely probably Puerto Rican is that + + + align:start position:0% +definitely probably Puerto Rican is that +it might be changing or at least there's + + align:start position:0% +it might be changing or at least there's + + + align:start position:0% +it might be changing or at least there's +kind of new groups coming in um and a + + align:start position:0% +kind of new groups coming in um and a + + + align:start position:0% +kind of new groups coming in um and a +lot of them are UND + + align:start position:0% + + + + align:start position:0% + +immigrants I guess I'll stop + + align:start position:0% +immigrants I guess I'll stop + + + align:start position:0% +immigrants I guess I'll stop +it uh I think those are the big things + + align:start position:0% +it uh I think those are the big things + + + align:start position:0% +it uh I think those are the big things +he also he he mentioned this guy I don't + + align:start position:0% +he also he he mentioned this guy I don't + + + align:start position:0% +he also he he mentioned this guy I don't +know Gonzalez who is an example of uh a + + align:start position:0% +know Gonzalez who is an example of uh a + + + align:start position:0% +know Gonzalez who is an example of uh a +successful businessman + + align:start position:0% +successful businessman + + + align:start position:0% +successful businessman +who I guess he owns or runs several + + align:start position:0% +who I guess he owns or runs several + + + align:start position:0% +who I guess he owns or runs several +stores in the north end but doesn't give + + align:start position:0% +stores in the north end but doesn't give + + + align:start position:0% +stores in the north end but doesn't give +back to the community so again just kind + + align:start position:0% +back to the community so again just kind + + + align:start position:0% +back to the community so again just kind +of like Bas there's all these like + + align:start position:0% +of like Bas there's all these like + + + align:start position:0% +of like Bas there's all these like +strong presences whether like + + align:start position:0% +strong presences whether like + + + align:start position:0% +strong presences whether like +institutional or individual in the + + align:start position:0% +institutional or individual in the + + + align:start position:0% +institutional or individual in the +neighborhood that are not good um + + align:start position:0% +neighborhood that are not good um + + + align:start position:0% +neighborhood that are not good um +Community are not good neighbors + + align:start position:0% +Community are not good neighbors + + + align:start position:0% +Community are not good neighbors +basically and really could do a lot + + align:start position:0% + + + + align:start position:0% + +more one of the things I said in on the + + align:start position:0% +more one of the things I said in on the + + + align:start position:0% +more one of the things I said in on the +interview one of the things I thought + + align:start position:0% +interview one of the things I thought + + + align:start position:0% +interview one of the things I thought +was very interesting that Michael said + + align:start position:0% +was very interesting that Michael said + + + align:start position:0% +was very interesting that Michael said +was about this whole thing about working + + align:start position:0% +was about this whole thing about working + + + align:start position:0% +was about this whole thing about working +with Bay State and B you know the change + + align:start position:0% +with Bay State and B you know the change + + + align:start position:0% +with Bay State and B you know the change +in their relationship and what was + + align:start position:0% +in their relationship and what was + + + align:start position:0% +in their relationship and what was +fascinating to me is his stance that + + align:start position:0% +fascinating to me is his stance that + + + align:start position:0% +fascinating to me is his stance that +they don't want anything from Bay State + + align:start position:0% +they don't want anything from Bay State + + + align:start position:0% +they don't want anything from Bay State +you it was very interesting that they've + + align:start position:0% +you it was very interesting that they've + + + align:start position:0% +you it was very interesting that they've +never really said we want you to do this + + align:start position:0% +never really said we want you to do this + + + align:start position:0% +never really said we want you to do this +that what they've said is we want you to + + align:start position:0% +that what they've said is we want you to + + + align:start position:0% +that what they've said is we want you to +recognize + + align:start position:0% +recognize + + + align:start position:0% +recognize +us you know and then come and present + + align:start position:0% +us you know and then come and present + + + align:start position:0% +us you know and then come and present +and recognize our Authority around some + + align:start position:0% +and recognize our Authority around some + + + align:start position:0% +and recognize our Authority around some +of this planning stuff but they have not + + align:start position:0% +of this planning stuff but they have not + + + align:start position:0% +of this planning stuff but they have not +made any demands really as a community + + align:start position:0% +made any demands really as a community + + + align:start position:0% +made any demands really as a community +on Bay + + align:start position:0% +on Bay + + + align:start position:0% +on Bay +State which I think is kind of + + align:start position:0% + + + + align:start position:0% + +interesting any other comments from that + + align:start position:0% +interesting any other comments from that + + + align:start position:0% +interesting any other comments from that +from other + + align:start position:0% +from other + + + align:start position:0% +from other +participant all said I don't know if you + + align:start position:0% +participant all said I don't know if you + + + align:start position:0% +participant all said I don't know if you +disappeared okay um so move on to + + align:start position:0% +disappeared okay um so move on to + + + align:start position:0% +disappeared okay um so move on to +Jeff summarize that + + align:start position:0% + + + + align:start position:0% + +Jeff what did Jeff have to say I feel + + align:start position:0% +Jeff what did Jeff have to say I feel + + + align:start position:0% +Jeff what did Jeff have to say I feel +there were a lot of us + + align:start position:0% +there were a lot of us + + + align:start position:0% +there were a lot of us +there there were a lot of so I'll say a + + align:start position:0% +there there were a lot of so I'll say a + + + align:start position:0% +there there were a lot of so I'll say a +couple of things and I'll invite all of + + align:start position:0% +couple of things and I'll invite all of + + + align:start position:0% +couple of things and I'll invite all of +those + + align:start position:0% + + + + align:start position:0% + +present that I might leave out + + align:start position:0% +present that I might leave out + + + align:start position:0% +present that I might leave out +um he also started out talking a lot + + align:start position:0% +um he also started out talking a lot + + + align:start position:0% +um he also started out talking a lot +about his history um both at the health + + align:start position:0% +about his history um both at the health + + + align:start position:0% +about his history um both at the health +clinic um and just in the neighborhood + + align:start position:0% +clinic um and just in the neighborhood + + + align:start position:0% +clinic um and just in the neighborhood +um about of + + align:start position:0% +um about of + + + align:start position:0% +um about of +his activist + + align:start position:0% + + + + align:start position:0% + +nature + + align:start position:0% + + + + align:start position:0% + +he what else he talked about we talked a + + align:start position:0% +he what else he talked about we talked a + + + align:start position:0% +he what else he talked about we talked a +lot about the history um then he went on + + align:start position:0% +lot about the history um then he went on + + + align:start position:0% +lot about the history um then he went on +to say I guess we didn't really get a + + align:start position:0% +to say I guess we didn't really get a + + + align:start position:0% +to say I guess we didn't really get a +lot of information about + + align:start position:0% +lot of information about + + + align:start position:0% +lot of information about +heal St thing I know you even tried to + + align:start position:0% +heal St thing I know you even tried to + + + align:start position:0% +heal St thing I know you even tried to +see the conversation that way a couple + + align:start position:0% +see the conversation that way a couple + + + align:start position:0% +see the conversation that way a couple +of points then that didn't really P out + + align:start position:0% +of points then that didn't really P out + + + align:start position:0% +of points then that didn't really P out +um but it does sound like he is + + align:start position:0% +um but it does sound like he is + + + align:start position:0% +um but it does sound like he is +something like he is very committed to + + align:start position:0% +something like he is very committed to + + + align:start position:0% +something like he is very committed to +his staff and so that + + align:start position:0% +his staff and so that + + + align:start position:0% +his staff and so that +is that's an + + align:start position:0% +is that's an + + + align:start position:0% +is that's an +ass um let see he it is Affiliated + + align:start position:0% +ass um let see he it is Affiliated + + + align:start position:0% +ass um let see he it is Affiliated +officially with B State um and has + + align:start position:0% +officially with B State um and has + + + align:start position:0% +officially with B State um and has +always been it + + align:start position:0% +always been it + + + align:start position:0% +always been it +has basically does not want the clinic + + align:start position:0% +has basically does not want the clinic + + + align:start position:0% +has basically does not want the clinic +to be an independent Clinic although + + align:start position:0% +to be an independent Clinic although + + + align:start position:0% +to be an independent Clinic although +Jeff said that he has should be + + align:start position:0% + + + + align:start position:0% + +mentioned trying + + align:start position:0% + + + + align:start position:0% + +to he said + + align:start position:0% +to he said + + + align:start position:0% +to he said +that there were three and this is I + + align:start position:0% +that there were three and this is I + + + align:start position:0% +that there were three and this is I +guess I wasn't really clear + + align:start position:0% +guess I wasn't really clear + + + align:start position:0% +guess I wasn't really clear +that neon is a + + align:start position:0% +that neon is a + + + align:start position:0% +that neon is a +product this is a + + align:start position:0% + + + + align:start position:0% + +program the okay so there are two other + + align:start position:0% +program the okay so there are two other + + + align:start position:0% +program the okay so there are two other +programs that he mentioned um one uh was + + align:start position:0% +programs that he mentioned um one uh was + + + align:start position:0% +programs that he mentioned um one uh was +s of a new approach to Primary Care team + + align:start position:0% +s of a new approach to Primary Care team + + + align:start position:0% +s of a new approach to Primary Care team +based + + align:start position:0% +based + + + align:start position:0% +based +not yeah sort of like that organization + + align:start position:0% +not yeah sort of like that organization + + + align:start position:0% +not yeah sort of like that organization +of professionals all working for one + + align:start position:0% +of professionals all working for one + + + align:start position:0% +of professionals all working for one +individual was one of the other programs + + align:start position:0% +individual was one of the other programs + + + align:start position:0% +individual was one of the other programs +mention the other wasal + + align:start position:0% +mention the other wasal + + + align:start position:0% +mention the other wasal +healthare um he then he went on to talk + + align:start position:0% +healthare um he then he went on to talk + + + align:start position:0% +healthare um he then he went on to talk +about so he talked about his history + + align:start position:0% +about so he talked about his history + + + align:start position:0% +about so he talked about his history +about history of the clinic uh and then + + align:start position:0% +about history of the clinic uh and then + + + align:start position:0% +about history of the clinic uh and then +he started talking about um s what he + + align:start position:0% +he started talking about um s what he + + + align:start position:0% +he started talking about um s what he +saw for other + + align:start position:0% +saw for other + + + align:start position:0% +saw for other +and he talked about personal care that + + align:start position:0% +and he talked about personal care that + + + align:start position:0% +and he talked about personal care that +was one of the things he talked about + + align:start position:0% +was one of the things he talked about + + + align:start position:0% +was one of the things he talked about +that being a possible area + + align:start position:0% +that being a possible area + + + align:start position:0% +that being a possible area +for both training um and then creating a + + align:start position:0% +for both training um and then creating a + + + align:start position:0% +for both training um and then creating a +supply of workers and then firstand + + align:start position:0% +supply of workers and then firstand + + + align:start position:0% +supply of workers and then firstand +problem um he also then spent a fair + + align:start position:0% +problem um he also then spent a fair + + + align:start position:0% +problem um he also then spent a fair +amount of time oh we talk similarly + + align:start position:0% +amount of time oh we talk similarly + + + align:start position:0% +amount of time oh we talk similarly +about Co-op daycare + + align:start position:0% +about Co-op daycare + + + align:start position:0% +about Co-op daycare +uh he then spent a amount of time + + align:start position:0% +uh he then spent a amount of time + + + align:start position:0% +uh he then spent a amount of time +talking about turning the North End um + + align:start position:0% +talking about turning the North End um + + + align:start position:0% +talking about turning the North End um +exp business small bus type of + + align:start position:0% +exp business small bus type of + + + align:start position:0% +exp business small bus type of +topic retail support area for + + align:start position:0% +topic retail support area for + + + align:start position:0% +topic retail support area for +B + + align:start position:0% +B + + + align:start position:0% +B +for recreational shopping but as well as + + align:start position:0% +for recreational shopping but as well as + + + align:start position:0% +for recreational shopping but as well as +serving U what he sees to + + align:start position:0% + + + + align:start position:0% + +be stff uh he talked about also brought + + align:start position:0% +be stff uh he talked about also brought + + + align:start position:0% +be stff uh he talked about also brought +corporation uh very similar opinions + + align:start position:0% +corporation uh very similar opinions + + + align:start position:0% +corporation uh very similar opinions +obstacle r as at this + + align:start position:0% +obstacle r as at this + + + align:start position:0% +obstacle r as at this +point Al that came up + + align:start position:0% +point Al that came up + + + align:start position:0% +point Al that came up +when + + align:start position:0% +when + + + align:start position:0% +when +oh + + align:start position:0% +oh + + + align:start position:0% +oh +yeah that was that was + + align:start position:0% + + + + align:start position:0% + +interesting yeah kind of + + align:start position:0% + + + + align:start position:0% + +changed what happened tell us some of us + + align:start position:0% +changed what happened tell us some of us + + + align:start position:0% +changed what happened tell us some of us +wenten there so why was it interesting + + align:start position:0% +wenten there so why was it interesting + + + align:start position:0% +wenten there so why was it interesting +well Robert came in and I guess it just + + align:start position:0% +well Robert came in and I guess it just + + + align:start position:0% +well Robert came in and I guess it just +changed it it must have been more just + + align:start position:0% +changed it it must have been more just + + + align:start position:0% +changed it it must have been more just +sort of was + + align:start position:0% + + + + align:start position:0% + +really we asked ask talk about the land + + align:start position:0% +really we asked ask talk about the land + + + align:start position:0% +really we asked ask talk about the land +trust idea + + align:start position:0% +trust idea + + + align:start position:0% +trust idea +right is + + align:start position:0% + + + + align:start position:0% + +else he also talked about kind of this + + align:start position:0% +else he also talked about kind of this + + + align:start position:0% +else he also talked about kind of this +idea of from he's part of like this + + align:start position:0% +idea of from he's part of like this + + + align:start position:0% +idea of from he's part of like this +whole we call it like the community he + + align:start position:0% +whole we call it like the community he + + + align:start position:0% +whole we call it like the community he +Center movement which was a whole um + + align:start position:0% +Center movement which was a whole um + + + align:start position:0% +Center movement which was a whole um +kind of idea I guess getting out of like + + align:start position:0% +kind of idea I guess getting out of like + + + align:start position:0% +kind of idea I guess getting out of like +major hospitals where patients go to + + align:start position:0% +major hospitals where patients go to + + + align:start position:0% +major hospitals where patients go to +hospital to try like having a community + + align:start position:0% +hospital to try like having a community + + + align:start position:0% +hospital to try like having a community +area that service by Clinic that's in a + + align:start position:0% +area that service by Clinic that's in a + + + align:start position:0% +area that service by Clinic that's in a +community and is kind of more the + + align:start position:0% +community and is kind of more the + + + align:start position:0% +community and is kind of more the +community is kind of on a board and like + + align:start position:0% +community is kind of on a board and like + + + align:start position:0% +community is kind of on a board and like +it's like the community kind of runs it + + align:start position:0% +it's like the community kind of runs it + + + align:start position:0% +it's like the community kind of runs it +in the way boards and associations and + + align:start position:0% +in the way boards and associations and + + + align:start position:0% +in the way boards and associations and +things kind of um and that that kind of + + align:start position:0% +things kind of um and that that kind of + + + align:start position:0% +things kind of um and that that kind of +movement also has an idea of like + + align:start position:0% +movement also has an idea of like + + + align:start position:0% +movement also has an idea of like +population based healthare which is what + + align:start position:0% +population based healthare which is what + + + align:start position:0% +population based healthare which is what +kind of his clinic and a lot of clinics + + align:start position:0% +kind of his clinic and a lot of clinics + + + align:start position:0% +kind of his clinic and a lot of clinics +that are involved in kind of this + + align:start position:0% +that are involved in kind of this + + + align:start position:0% +that are involved in kind of this +movement the 60s kind um which is like + + align:start position:0% +movement the 60s kind um which is like + + + align:start position:0% +movement the 60s kind um which is like +not looking it not saying okay how many + + align:start position:0% +not looking it not saying okay how many + + + align:start position:0% +not looking it not saying okay how many +we have 50 people who came to our clinic + + align:start position:0% +we have 50 people who came to our clinic + + + align:start position:0% +we have 50 people who came to our clinic +and 20 of them got well it's it's like + + align:start position:0% +and 20 of them got well it's it's like + + + align:start position:0% +and 20 of them got well it's it's like +looking at like the whole community so + + align:start position:0% +looking at like the whole community so + + + align:start position:0% +looking at like the whole community so +even if you don't see that person in + + align:start position:0% +even if you don't see that person in + + + align:start position:0% +even if you don't see that person in +your clinic that's the clinic + + align:start position:0% +your clinic that's the clinic + + + align:start position:0% +your clinic that's the clinic +responsibility to bring that person in + + align:start position:0% +responsibility to bring that person in + + + align:start position:0% +responsibility to bring that person in +the clinic and still give care to that + + align:start position:0% +the clinic and still give care to that + + + align:start position:0% +the clinic and still give care to that +person even if that person isn't on + + align:start position:0% +person even if that person isn't on + + + align:start position:0% +person even if that person isn't on +their own come to the clinic like + + align:start position:0% +their own come to the clinic like + + + align:start position:0% +their own come to the clinic like +looking at the + + align:start position:0% + + + + align:start position:0% + +whole so um and then well like what is + + align:start position:0% +whole so um and then well like what is + + + align:start position:0% +whole so um and then well like what is +that and and this is like something that + + align:start position:0% +that and and this is like something that + + + align:start position:0% +that and and this is like something that +um like like um I've asked this question + + align:start position:0% +um like like um I've asked this question + + + align:start position:0% +um like like um I've asked this question +because like people at neon also I've + + align:start position:0% +because like people at neon also I've + + + align:start position:0% +because like people at neon also I've +heard this several times and I talked to + + align:start position:0% +heard this several times and I talked to + + + align:start position:0% +heard this several times and I talked to +Myra about like what it was because she + + align:start position:0% +Myra about like what it was because she + + + align:start position:0% +Myra about like what it was because she +she stressed again like a coule stressed + + align:start position:0% +she stressed again like a coule stressed + + + align:start position:0% +she stressed again like a coule stressed +like neon is kind of a population based + + align:start position:0% +like neon is kind of a population based + + + align:start position:0% +like neon is kind of a population based +organization has a population based + + align:start position:0% +organization has a population based + + + align:start position:0% +organization has a population based +approach which is you know they knock on + + align:start position:0% +approach which is you know they knock on + + + align:start position:0% +approach which is you know they knock on +like the way my's been it's like you + + align:start position:0% +like the way my's been it's like you + + + align:start position:0% +like the way my's been it's like you +knock on the door every you know and try + + align:start position:0% +knock on the door every you know and try + + + align:start position:0% +knock on the door every you know and try +to reach everybody it's not just the + + align:start position:0% +to reach everybody it's not just the + + + align:start position:0% +to reach everybody it's not just the +person that aners the door it's like + + align:start position:0% +person that aners the door it's like + + + align:start position:0% +person that aners the door it's like +everybody in that house is part of the + + align:start position:0% +everybody in that house is part of the + + + align:start position:0% +everybody in that house is part of the +community and hopefully they can access + + align:start position:0% +community and hopefully they can access + + + align:start position:0% +community and hopefully they can access +all of people to it's not just people + + align:start position:0% +all of people to it's not just people + + + align:start position:0% +all of people to it's not just people +that show to Mee programs like that so + + align:start position:0% +that show to Mee programs like that so + + + align:start position:0% +that show to Mee programs like that so +then call asked a question like what + + align:start position:0% +then call asked a question like what + + + align:start position:0% +then call asked a question like what +would that mean for like Economic + + align:start position:0% +would that mean for like Economic + + + align:start position:0% +would that mean for like Economic +Development so then he kind of talked + + align:start position:0% +Development so then he kind of talked + + + align:start position:0% +Development so then he kind of talked +about maybe an um maybe what this kind + + align:start position:0% +about maybe an um maybe what this kind + + + align:start position:0% +about maybe an um maybe what this kind +of community based approach would for + + align:start position:0% +of community based approach would for + + + align:start position:0% +of community based approach would for +economic development is looking at maybe + + align:start position:0% +economic development is looking at maybe + + + align:start position:0% +economic development is looking at maybe +things that wouldn't Target like not + + align:start position:0% +things that wouldn't Target like not + + + align:start position:0% +things that wouldn't Target like not +like a Workforce program that would + + align:start position:0% +like a Workforce program that would + + + align:start position:0% +like a Workforce program that would +Target Like A specific group were + + align:start position:0% +Target Like A specific group were + + + align:start position:0% +Target Like A specific group were +interested but things that would make a + + align:start position:0% +interested but things that would make a + + + align:start position:0% +interested but things that would make a +large change for everybody in the + + align:start position:0% +large change for everybody in the + + + align:start position:0% +large change for everybody in the +neighborhood and he kind of talked about + + align:start position:0% +neighborhood and he kind of talked about + + + align:start position:0% +neighborhood and he kind of talked about +this idea that kind of like in most + + align:start position:0% +this idea that kind of like in most + + + align:start position:0% +this idea that kind of like in most +places like the community he was talking + + align:start position:0% +places like the community he was talking + + + align:start position:0% +places like the community he was talking +about where he lived in like where he + + align:start position:0% +about where he lived in like where he + + + align:start position:0% +about where he lived in like where he +grab in Queens it was like there were + + align:start position:0% +grab in Queens it was like there were + + + align:start position:0% +grab in Queens it was like there were +like 70% of people that that were pretty + + align:start position:0% +like 70% of people that that were pretty + + + align:start position:0% +like 70% of people that that were pretty +well out and doing okay and then like + + align:start position:0% +well out and doing okay and then like + + + align:start position:0% +well out and doing okay and then like +30% of people that were really + + align:start position:0% +30% of people that were really + + + align:start position:0% +30% of people that were really +struggling and that 70% really helped + + align:start position:0% +struggling and that 70% really helped + + + align:start position:0% +struggling and that 70% really helped +with 30% that were struggling so the + + align:start position:0% +with 30% that were struggling so the + + + align:start position:0% +with 30% that were struggling so the +commun was was great was well off and he + + align:start position:0% +commun was was great was well off and he + + + align:start position:0% +commun was was great was well off and he +said that that that's a little bit + + align:start position:0% +said that that that's a little bit + + + align:start position:0% +said that that that's a little bit +reversed in the North End so you have + + align:start position:0% +reversed in the North End so you have + + + align:start position:0% +reversed in the North End so you have +like 70% of people who aren't doing okay + + align:start position:0% +like 70% of people who aren't doing okay + + + align:start position:0% +like 70% of people who aren't doing okay +and 30% % of people who are doing okay + + align:start position:0% +and 30% % of people who are doing okay + + + align:start position:0% +and 30% % of people who are doing okay +but that 70% the massive kind of um + + align:start position:0% +but that 70% the massive kind of um + + + align:start position:0% +but that 70% the massive kind of um +that's kind of the big presence of opin + + align:start position:0% +that's kind of the big presence of opin + + + align:start position:0% +that's kind of the big presence of opin +kind of brings that 30% down so the + + align:start position:0% +kind of brings that 30% down so the + + + align:start position:0% +kind of brings that 30% down so the +whole Community isn't doing well so he + + align:start position:0% +whole Community isn't doing well so he + + + align:start position:0% +whole Community isn't doing well so he +kind of talking about approaches that + + align:start position:0% +kind of talking about approaches that + + + align:start position:0% +kind of talking about approaches that +would maybe um change the community kind + + align:start position:0% +would maybe um change the community kind + + + align:start position:0% +would maybe um change the community kind +of like on a larger scale and kind of + + align:start position:0% +of like on a larger scale and kind of + + + align:start position:0% +of like on a larger scale and kind of +get it to that 70% of people that were + + align:start position:0% +get it to that 70% of people that were + + + align:start position:0% +get it to that 70% of people that were +doing okay so the whole Community get + + align:start position:0% +doing okay so the whole Community get + + + align:start position:0% +doing okay so the whole Community get +kind of benefit from + + align:start position:0% + + + + align:start position:0% + +that one thing I would add is + + align:start position:0% +that one thing I would add is + + + align:start position:0% +that one thing I would add is +that one of the um the population based + + align:start position:0% +that one of the um the population based + + + align:start position:0% +that one of the um the population based +approach and the Outreach through + + align:start position:0% +approach and the Outreach through + + + align:start position:0% +approach and the Outreach through +through neon produced real Financial + + align:start position:0% +through neon produced real Financial + + + align:start position:0% +through neon produced real Financial +benefits for base a because they were + + align:start position:0% +benefits for base a because they were + + + align:start position:0% +benefits for base a because they were +able to sign everyone up who was + + align:start position:0% +able to sign everyone up who was + + + align:start position:0% +able to sign everyone up who was +eligible for Medicaid or some other + + align:start position:0% +eligible for Medicaid or some other + + + align:start position:0% +eligible for Medicaid or some other +health insurance plan so B they dropped + + align:start position:0% +health insurance plan so B they dropped + + + align:start position:0% +health insurance plan so B they dropped +Bas States uninsured percentage of of + + align:start position:0% +Bas States uninsured percentage of of + + + align:start position:0% +Bas States uninsured percentage of of +patients from 16% to 18% as were all the + + align:start position:0% +patients from 16% to 18% as were all the + + + align:start position:0% +patients from 16% to 18% as were all the +other community health clinics still + + align:start position:0% +other community health clinics still + + + align:start position:0% +other community health clinics still +have this 16% uninsured so it it it sort + + align:start position:0% +have this 16% uninsured so it it it sort + + + align:start position:0% +have this 16% uninsured so it it it sort +of did have this benefit for base Aid + + align:start position:0% +of did have this benefit for base Aid + + + align:start position:0% +of did have this benefit for base Aid +and and at least you know one of his + + align:start position:0% +and and at least you know one of his + + + align:start position:0% +and and at least you know one of his +other themes were there there's enough + + align:start position:0% +other themes were there there's enough + + + align:start position:0% +other themes were there there's enough +money in the healthare system that if + + align:start position:0% +money in the healthare system that if + + + align:start position:0% +money in the healthare system that if +you find ways to save money through + + align:start position:0% +you find ways to save money through + + + align:start position:0% +you find ways to save money through +actually delivering Better Health Care + + align:start position:0% +actually delivering Better Health Care + + + align:start position:0% +actually delivering Better Health Care +that does free them up some resources to + + align:start position:0% +that does free them up some resources to + + + align:start position:0% +that does free them up some resources to +do some other type of things um so that + + align:start position:0% +do some other type of things um so that + + + align:start position:0% +do some other type of things um so that +that that I thought was kind of + + align:start position:0% +that that I thought was kind of + + + align:start position:0% +that that I thought was kind of +interesting um um and that they were + + align:start position:0% +interesting um um and that they were + + + align:start position:0% +interesting um um and that they were +able to sort of bring about these kind + + align:start position:0% +able to sort of bring about these kind + + + align:start position:0% +able to sort of bring about these kind +of changes they sort of were able to + + align:start position:0% +of changes they sort of were able to + + + align:start position:0% +of changes they sort of were able to +sort of change the healthcare Del system + + align:start position:0% +sort of change the healthcare Del system + + + align:start position:0% +sort of change the healthcare Del system +and in what seemed to be you know + + align:start position:0% +and in what seemed to be you know + + + align:start position:0% +and in what seemed to be you know +overcome a lot of organizational + + align:start position:0% +overcome a lot of organizational + + + align:start position:0% +overcome a lot of organizational +obstacles he did walk us through this + + align:start position:0% +obstacles he did walk us through this + + + align:start position:0% +obstacles he did walk us through this +process he used to eventually get the + + align:start position:0% +process he used to eventually get the + + + align:start position:0% +process he used to eventually get the +the community health centers in the + + align:start position:0% +the community health centers in the + + + align:start position:0% +the community health centers in the +Springfield area to take responsibility + + align:start position:0% +Springfield area to take responsibility + + + align:start position:0% +Springfield area to take responsibility +for the healthc care of + + align:start position:0% +for the healthc care of + + + align:start position:0% +for the healthc care of +prisoners um so that they weren't you + + align:start position:0% +prisoners um so that they weren't you + + + align:start position:0% +prisoners um so that they weren't you +know having AIDS going into prison stop + + align:start position:0% +know having AIDS going into prison stop + + + align:start position:0% +know having AIDS going into prison stop +getting care and then coming back out + + align:start position:0% +getting care and then coming back out + + + align:start position:0% +getting care and then coming back out +with really deteriorated Health that + + align:start position:0% +with really deteriorated Health that + + + align:start position:0% +with really deteriorated Health that +also kind of interesting no I just want + + align:start position:0% +also kind of interesting no I just want + + + align:start position:0% +also kind of interesting no I just want +to say something on that because I think + + align:start position:0% +to say something on that because I think + + + align:start position:0% +to say something on that because I think +it's one of the interesting things about + + align:start position:0% +it's one of the interesting things about + + + align:start position:0% +it's one of the interesting things about +the + + align:start position:0% +the + + + align:start position:0% +the +health uh work that they're doing + + align:start position:0% +health uh work that they're doing + + + align:start position:0% +health uh work that they're doing +because I think often when we look at it + + align:start position:0% +because I think often when we look at it + + + align:start position:0% +because I think often when we look at it +we talk about it and think about it in + + align:start position:0% +we talk about it and think about it in + + + align:start position:0% +we talk about it and think about it in +that but this is about Healthcare it's + + align:start position:0% +that but this is about Healthcare it's + + + align:start position:0% +that but this is about Healthcare it's +about the Social Service delivery + + align:start position:0% +about the Social Service delivery + + + align:start position:0% +about the Social Service delivery +component of things but there have been + + align:start position:0% +component of things but there have been + + + align:start position:0% +component of things but there have been +some very interesting experimental + + align:start position:0% +some very interesting experimental + + + align:start position:0% +some very interesting experimental +business ideas you know economic ideas + + align:start position:0% +business ideas you know economic ideas + + + align:start position:0% +business ideas you know economic ideas +and what they've been doing with + + align:start position:0% +and what they've been doing with + + + align:start position:0% +and what they've been doing with +Healthcare that I think they haven't + + align:start position:0% +Healthcare that I think they haven't + + + align:start position:0% +Healthcare that I think they haven't +figured out how to leverage in really + + align:start position:0% +figured out how to leverage in really + + + align:start position:0% +figured out how to leverage in really +powerful ways so for example the + + align:start position:0% +powerful ways so for example the + + + align:start position:0% +powerful ways so for example the +Medicaid one that they're + + align:start position:0% +Medicaid one that they're + + + align:start position:0% +Medicaid one that they're +doing you know if you ask Jeff if + + align:start position:0% +doing you know if you ask Jeff if + + + align:start position:0% +doing you know if you ask Jeff if +they've been able to recoup an equal + + align:start position:0% +they've been able to recoup an equal + + + align:start position:0% +they've been able to recoup an equal +amount of the savings for them as + + align:start position:0% +amount of the savings for them as + + + align:start position:0% +amount of the savings for them as +opposed to going to Bay State they don't + + align:start position:0% +opposed to going to Bay State they don't + + + align:start position:0% +opposed to going to Bay State they don't +feel that they have been able to uh the + + align:start position:0% +feel that they have been able to uh the + + + align:start position:0% +feel that they have been able to uh the +same thing with with the insurance if + + align:start position:0% +same thing with with the insurance if + + + align:start position:0% +same thing with with the insurance if +Bay State gets a savings what's the + + align:start position:0% +Bay State gets a savings what's the + + + align:start position:0% +Bay State gets a savings what's the +benefit for the community clearly + + align:start position:0% +benefit for the community clearly + + + align:start position:0% +benefit for the community clearly +there's a health benefit but if there's + + align:start position:0% +there's a health benefit but if there's + + + align:start position:0% +there's a health benefit but if there's +a financial benefit for Bay State you + + align:start position:0% +a financial benefit for Bay State you + + + align:start position:0% +a financial benefit for Bay State you +know the community doesn't they don't + + align:start position:0% +know the community doesn't they don't + + + align:start position:0% +know the community doesn't they don't +they can't monetize you know get any + + align:start position:0% +they can't monetize you know get any + + + align:start position:0% +they can't monetize you know get any +value they trying aren't they trying to + + align:start position:0% +value they trying aren't they trying to + + + align:start position:0% +value they trying aren't they trying to +negotiate some cost sharing Arrangements + + align:start position:0% +negotiate some cost sharing Arrangements + + + align:start position:0% +negotiate some cost sharing Arrangements +they're trying to negotiate some of that + + align:start position:0% +they're trying to negotiate some of that + + + align:start position:0% +they're trying to negotiate some of that +but don't kind of have it but I think + + align:start position:0% +but don't kind of have it but I think + + + align:start position:0% +but don't kind of have it but I think +it's and then there's a third one thing + + align:start position:0% +it's and then there's a third one thing + + + align:start position:0% +it's and then there's a third one thing +with the prison thing is interesting + + align:start position:0% +with the prison thing is interesting + + + align:start position:0% +with the prison thing is interesting +because part of what they did with their + + align:start position:0% +because part of what they did with their + + + align:start position:0% +because part of what they did with their +model with the prison is because so many + + align:start position:0% +model with the prison is because so many + + + align:start position:0% +model with the prison is because so many +what's happened is is that a lot of the + + align:start position:0% +what's happened is is that a lot of the + + + align:start position:0% +what's happened is is that a lot of the +prisoners have gone to contract it their + + align:start position:0% +prisoners have gone to contract it their + + + align:start position:0% +prisoners have gone to contract it their +health care out to private and they've + + align:start position:0% +health care out to private and they've + + + align:start position:0% +health care out to private and they've +been able to show that they can provide + + align:start position:0% +been able to show that they can provide + + + align:start position:0% +been able to show that they can provide +the same care better care for less money + + align:start position:0% +the same care better care for less money + + + align:start position:0% +the same care better care for less money +you know into this contract ser and + + align:start position:0% +you know into this contract ser and + + + align:start position:0% +you know into this contract ser and +there's an interesting there's a model + + align:start position:0% +there's an interesting there's a model + + + align:start position:0% +there's an interesting there's a model +there so I just think it's interesting + + align:start position:0% +there so I just think it's interesting + + + align:start position:0% +there so I just think it's interesting +you have kind of like three different + + align:start position:0% +you have kind of like three different + + + align:start position:0% +you have kind of like three different +things that have happened Happ around + + align:start position:0% +things that have happened Happ around + + + align:start position:0% +things that have happened Happ around +the health thing where they're able to + + align:start position:0% +the health thing where they're able to + + + align:start position:0% +the health thing where they're able to +demonstrate that there's some way which + + align:start position:0% +demonstrate that there's some way which + + + align:start position:0% +demonstrate that there's some way which +financial benefits they Financial + + align:start position:0% +financial benefits they Financial + + + align:start position:0% +financial benefits they Financial +benefits they don't they don't capture + + align:start position:0% +benefits they don't they don't capture + + + align:start position:0% +benefits they don't they don't capture +they don't capture that cost savings and + + align:start position:0% +they don't capture that cost savings and + + + align:start position:0% +they don't capture that cost savings and +so that does raise interest if if they + + align:start position:0% +so that does raise interest if if they + + + align:start position:0% +so that does raise interest if if they +could capture some of that could that be + + align:start position:0% +could capture some of that could that be + + + align:start position:0% +could capture some of that could that be +a revenue stream that could help support + + align:start position:0% +a revenue stream that could help support + + + align:start position:0% +a revenue stream that could help support +you know other activities all + + align:start position:0% + + + + align:start position:0% + +right it was actually and just as a side + + align:start position:0% +right it was actually and just as a side + + + align:start position:0% +right it was actually and just as a side +note I don't when Massachusetts Housing + + align:start position:0% +note I don't when Massachusetts Housing + + + align:start position:0% +note I don't when Massachusetts Housing +Finance + + align:start position:0% +Finance + + + align:start position:0% +Finance +agency mhf when they were when they were + + align:start position:0% +agency mhf when they were when they were + + + align:start position:0% +agency mhf when they were when they were +mhfa they called Mass housing there was + + align:start position:0% +mhfa they called Mass housing there was + + + align:start position:0% +mhfa they called Mass housing there was +a gentleman called Tony flare who uh + + align:start position:0% +a gentleman called Tony flare who uh + + + align:start position:0% +a gentleman called Tony flare who uh +worked for them doing uh kind of + + align:start position:0% +worked for them doing uh kind of + + + align:start position:0% +worked for them doing uh kind of +community outreach and he got very + + align:start position:0% +community outreach and he got very + + + align:start position:0% +community outreach and he got very +interested + + align:start position:0% +interested + + + align:start position:0% +interested +in uh the insurance cost that they had + + align:start position:0% +in uh the insurance cost that they had + + + align:start position:0% +in uh the insurance cost that they had +to pay on buildings that they had and + + align:start position:0% +to pay on buildings that they had and + + + align:start position:0% +to pay on buildings that they had and +that in places where there were you know + + align:start position:0% +that in places where there were you know + + + align:start position:0% +that in places where there were you know +kind of high poverty and issues of you + + align:start position:0% +kind of high poverty and issues of you + + + align:start position:0% +kind of high poverty and issues of you +know drugs and things like that that you + + align:start position:0% +know drugs and things like that that you + + + align:start position:0% +know drugs and things like that that you +know the insurance premiums were high + + align:start position:0% +know the insurance premiums were high + + + align:start position:0% +know the insurance premiums were high +and he actually struck this deal with + + align:start position:0% +and he actually struck this deal with + + + align:start position:0% +and he actually struck this deal with +some of the insurance companies that if + + align:start position:0% +some of the insurance companies that if + + + align:start position:0% +some of the insurance companies that if +he could lower their loss + + align:start position:0% +he could lower their loss + + + align:start position:0% +he could lower their loss +rate right would they split with him + + align:start position:0% +rate right would they split with him + + + align:start position:0% +rate right would they split with him +5050 the savings and they actually ended + + align:start position:0% +5050 the savings and they actually ended + + + align:start position:0% +5050 the savings and they actually ended +up building the whole + + align:start position:0% +up building the whole + + + align:start position:0% +up building the whole +Community uh service program out of mhfa + + align:start position:0% +Community uh service program out of mhfa + + + align:start position:0% +Community uh service program out of mhfa +out of that whole insurance program + + align:start position:0% +out of that whole insurance program + + + align:start position:0% +out of that whole insurance program +which actually became a Mainstay of what + + align:start position:0% +which actually became a Mainstay of what + + + align:start position:0% +which actually became a Mainstay of what +Mass housing does now which is uh so + + align:start position:0% +Mass housing does now which is uh so + + + align:start position:0% +Mass housing does now which is uh so +there's some ways in which that can + + align:start position:0% +there's some ways in which that can + + + align:start position:0% +there's some ways in which that can +happen so + + align:start position:0% + + + + align:start position:0% + +but I you want to move on to this + + align:start position:0% +but I you want to move on to this + + + align:start position:0% +but I you want to move on to this +population base yeah if people want to + + align:start position:0% +population base yeah if people want to + + + align:start position:0% +population base yeah if people want to +take a few minutes to talk about the + + align:start position:0% +take a few minutes to talk about the + + + align:start position:0% +take a few minutes to talk about the +inventory or do you want to maybe maybe + + align:start position:0% +inventory or do you want to maybe maybe + + + align:start position:0% +inventory or do you want to maybe maybe +it's more of a segue to go into this + + align:start position:0% +it's more of a segue to go into this + + + align:start position:0% +it's more of a segue to go into this +population based discussion yeah okay so + + align:start position:0% + + + + align:start position:0% + +um Bailey + + align:start position:0% + + + + align:start position:0% + +okay you want to name them both yeah so + + align:start position:0% +okay you want to name them both yeah so + + + align:start position:0% +okay you want to name them both yeah so +so first was we were walking + + align:start position:0% +so first was we were walking + + + align:start position:0% +so first was we were walking +by the physical site + + align:start position:0% +by the physical site + + + align:start position:0% +by the physical site +where located and W quite sure which + + align:start position:0% +where located and W quite sure which + + + align:start position:0% +where located and W quite sure which +agency it was it + + align:start position:0% +agency it was it + + + align:start position:0% +agency it was it +just outside and I actually different + + align:start position:0% +just outside and I actually different + + + align:start position:0% +just outside and I actually different +agency that was out of the whole of that + + align:start position:0% + + + + align:start position:0% + +campus and Kam was like no no no we are + + align:start position:0% +campus and Kam was like no no no we are + + + align:start position:0% +campus and Kam was like no no no we are +under there umbrella on let's go + + align:start position:0% +under there umbrella on let's go + + + align:start position:0% +under there umbrella on let's go +inside don't have time but she of + + align:start position:0% +inside don't have time but she of + + + align:start position:0% +inside don't have time but she of +dragged Us in and + + align:start position:0% + + + + align:start position:0% + +uh + + align:start position:0% +uh + + + align:start position:0% +uh +a + + align:start position:0% +a + + + align:start position:0% +a +and he gave us about 10 minutes time and + + align:start position:0% +and he gave us about 10 minutes time and + + + align:start position:0% +and he gave us about 10 minutes time and +actually was just getting wound up + + align:start position:0% +actually was just getting wound up + + + align:start position:0% +actually was just getting wound up +really all the work they had been doing + + align:start position:0% +really all the work they had been doing + + + align:start position:0% +really all the work they had been doing +and how they had come every conceivable + + align:start position:0% +and how they had come every conceivable + + + align:start position:0% +and how they had come every conceivable +vibe from + + align:start position:0% +vibe from + + + align:start position:0% +vibe from +development prevention to car the + + align:start position:0% +development prevention to car the + + + align:start position:0% +development prevention to car the +seniors and the interesting thing of saw + + align:start position:0% +seniors and the interesting thing of saw + + + align:start position:0% +seniors and the interesting thing of saw +that car seniors is the way + + align:start position:0% +that car seniors is the way + + + align:start position:0% +that car seniors is the way +in and smashion work + + align:start position:0% +in and smashion work + + + align:start position:0% +in and smashion work +together and a little taste of them you + + align:start position:0% +together and a little taste of them you + + + align:start position:0% +together and a little taste of them you +know of seeing their organization as + + align:start position:0% +know of seeing their organization as + + + align:start position:0% +know of seeing their organization as +a hybrid commity based organization + + align:start position:0% +a hybrid commity based organization + + + align:start position:0% +a hybrid commity based organization +CDC trying to do pieces of work that + + align:start position:0% +CDC trying to do pieces of work that + + + align:start position:0% +CDC trying to do pieces of work that +might otherwise be + + align:start position:0% +might otherwise be + + + align:start position:0% +might otherwise be +a types and then when he turned + + align:start position:0% +a types and then when he turned + + + align:start position:0% +a types and then when he turned +up almost unexpectedly at lunch he prob + + align:start position:0% +up almost unexpectedly at lunch he prob + + + align:start position:0% +up almost unexpectedly at lunch he prob +wasn't going to have time to and it + + align:start position:0% +wasn't going to have time to and it + + + align:start position:0% +wasn't going to have time to and it +didn't seem like Tak care of the that + + align:start position:0% +didn't seem like Tak care of the that + + + align:start position:0% +didn't seem like Tak care of the that +keeping away so I don't think that any + + align:start position:0% +keeping away so I don't think that any + + + align:start position:0% +keeping away so I don't think that any +of that of pressure had really been + + align:start position:0% +of that of pressure had really been + + + align:start position:0% +of that of pressure had really been +released um I think he really wanted to + + align:start position:0% +released um I think he really wanted to + + + align:start position:0% +released um I think he really wanted to +talk about the need for a strong CDC in + + align:start position:0% +talk about the need for a strong CDC in + + + align:start position:0% +talk about the need for a strong CDC in +the area and + + align:start position:0% +the area and + + + align:start position:0% +the area and +that he had very specific ideas of what + + align:start position:0% +that he had very specific ideas of what + + + align:start position:0% +that he had very specific ideas of what +their mandate would be how that would + + align:start position:0% +their mandate would be how that would + + + align:start position:0% +their mandate would be how that would +support existing + + align:start position:0% +support existing + + + align:start position:0% +support existing +organizations there are two things about + + align:start position:0% +organizations there are two things about + + + align:start position:0% +organizations there are two things about +that that I struck by one and this again + + align:start position:0% +that that I struck by one and this again + + + align:start position:0% +that that I struck by one and this again +Taste of this even + + align:start position:0% +Taste of this even + + + align:start position:0% +Taste of this even +earlier + + align:start position:0% + + + + align:start position:0% + +relationship + + align:start position:0% +relationship + + + align:start position:0% +relationship +very the whole day previous night + + align:start position:0% +very the whole day previous night + + + align:start position:0% +very the whole day previous night +actually + + align:start position:0% + + + + align:start position:0% + +he seemed really around him in I don't + + align:start position:0% +he seemed really around him in I don't + + + align:start position:0% +he seemed really around him in I don't +know what the history there is and the + + align:start position:0% +know what the history there is and the + + + align:start position:0% +know what the history there is and the +second was almost like he was to Spanish + + align:start position:0% +second was almost like he was to Spanish + + + align:start position:0% +second was almost like he was to Spanish +Amer + + align:start position:0% + + + + align:start position:0% + +CC interesting but that's our that's a + + align:start position:0% +CC interesting but that's our that's a + + + align:start position:0% +CC interesting but that's our that's a +very + + align:start position:0% +very + + + align:start position:0% +very +different everything we' talked about + + align:start position:0% +different everything we' talked about + + + align:start position:0% +different everything we' talked about +so also did kind of introduce himself in + + align:start position:0% +so also did kind of introduce himself in + + + align:start position:0% +so also did kind of introduce himself in +an unusual I thought an unusual way + + align:start position:0% +an unusual I thought an unusual way + + + align:start position:0% +an unusual I thought an unusual way +because he emphasized + + align:start position:0% +because he emphasized + + + align:start position:0% +because he emphasized +his + + align:start position:0% +his + + + align:start position:0% +his +accounting background he was kind of + + align:start position:0% +accounting background he was kind of + + + align:start position:0% +accounting background he was kind of +like you know I've been I forget the + + align:start position:0% +like you know I've been I forget the + + + align:start position:0% +like you know I've been I forget the +fiscal administrator or something like + + align:start position:0% +fiscal administrator or something like + + + align:start position:0% +fiscal administrator or something like +that and you know I kind of ended up as + + align:start position:0% +that and you know I kind of ended up as + + + align:start position:0% +that and you know I kind of ended up as +executive director because everyone else + + align:start position:0% +executive director because everyone else + + + align:start position:0% +executive director because everyone else +came and went was almost how he told the + + align:start position:0% +came and went was almost how he told the + + + align:start position:0% +came and went was almost how he told the +story and and I still do the fiscal work + + align:start position:0% +story and and I still do the fiscal work + + + align:start position:0% +story and and I still do the fiscal work +and I really like the fiscal work it was + + align:start position:0% +and I really like the fiscal work it was + + + align:start position:0% +and I really like the fiscal work it was +it was it was an unusual way to + + align:start position:0% +it was it was an unusual way to + + + align:start position:0% +it was it was an unusual way to +introduce yourself was director for a + + align:start position:0% +introduce yourself was director for a + + + align:start position:0% +introduce yourself was director for a +while and + + align:start position:0% +while and + + + align:start position:0% +while and +actually a buch g us old business Cs and + + align:start position:0% +actually a buch g us old business Cs and + + + align:start position:0% +actually a buch g us old business Cs and +said + + align:start position:0% + + + + align:start position:0% + +scratched yeah well see that's that's + + align:start position:0% +scratched yeah well see that's that's + + + align:start position:0% +scratched yeah well see that's that's +the thing I had gone up to him and just + + align:start position:0% +the thing I had gone up to him and just + + + align:start position:0% +the thing I had gone up to him and just +to get the business cards and he you + + align:start position:0% +to get the business cards and he you + + + align:start position:0% +to get the business cards and he you +know each one he he very methodically + + align:start position:0% +know each one he he very methodically + + + align:start position:0% +know each one he he very methodically +crossed off the um and he also kind of + + align:start position:0% +crossed off the um and he also kind of + + + align:start position:0% +crossed off the um and he also kind of +talked me up and I think he mentioned it + + align:start position:0% +talked me up and I think he mentioned it + + + align:start position:0% +talked me up and I think he mentioned it +a little bit at lunch his the kind of + + align:start position:0% +a little bit at lunch his the kind of + + + align:start position:0% +a little bit at lunch his the kind of +land trust idea I guess I don't know if + + align:start position:0% +land trust idea I guess I don't know if + + + align:start position:0% +land trust idea I guess I don't know if +they've gotten money for that but it + + align:start position:0% +they've gotten money for that but it + + + align:start position:0% +they've gotten money for that but it +seemed that what he was emphasizing to + + align:start position:0% +seemed that what he was emphasizing to + + + align:start position:0% +seemed that what he was emphasizing to +me and maybe this is is the role that + + align:start position:0% +me and maybe this is is the role that + + + align:start position:0% +me and maybe this is is the role that +that where neon comes in that it's not + + align:start position:0% +that where neon comes in that it's not + + + align:start position:0% +that where neon comes in that it's not +so much you know the Spanish American + + align:start position:0% +so much you know the Spanish American + + + align:start position:0% +so much you know the Spanish American +Union that has to do the work of of kind + + align:start position:0% +Union that has to do the work of of kind + + + align:start position:0% +Union that has to do the work of of kind +of land banking but that the community + + align:start position:0% +of land banking but that the community + + + align:start position:0% +of land banking but that the community +itself has to kind of see the value and + + align:start position:0% +itself has to kind of see the value and + + + align:start position:0% +itself has to kind of see the value and +land trust and really take um the the + + align:start position:0% +land trust and really take um the the + + + align:start position:0% +land trust and really take um the the +Reigns and and and uh move that concept + + align:start position:0% +Reigns and and and uh move that concept + + + align:start position:0% +Reigns and and and uh move that concept +forward so there was it seemed kind of + + align:start position:0% +forward so there was it seemed kind of + + + align:start position:0% +forward so there was it seemed kind of +like it was a big idea a lot of work to + + align:start position:0% +like it was a big idea a lot of work to + + + align:start position:0% +like it was a big idea a lot of work to +be done and he was really kind of + + align:start position:0% +be done and he was really kind of + + + align:start position:0% +be done and he was really kind of +looking to spread that Work Out Among + + align:start position:0% +looking to spread that Work Out Among + + + align:start position:0% +looking to spread that Work Out Among +the community and using it as a + + align:start position:0% +the community and using it as a + + + align:start position:0% +the community and using it as a +community organiz + + align:start position:0% +community organiz + + + align:start position:0% +community organiz +kind of concept but I guess it didn't + + align:start position:0% +kind of concept but I guess it didn't + + + align:start position:0% +kind of concept but I guess it didn't +you know he did it seemed like he wasn't + + align:start position:0% +you know he did it seemed like he wasn't + + + align:start position:0% +you know he did it seemed like he wasn't +necessarily too sure about how to + + align:start position:0% +necessarily too sure about how to + + + align:start position:0% +necessarily too sure about how to +execute that + + align:start position:0% + + + + align:start position:0% + +idea very good + + align:start position:0% +idea very good + + + align:start position:0% +idea very good +observations I'll leave it at + + align:start position:0% + + + + align:start position:0% + +that I think no I think they're very + + align:start position:0% +that I think no I think they're very + + + align:start position:0% +that I think no I think they're very +good observations about what's what's + + align:start position:0% +good observations about what's what's + + + align:start position:0% +good observations about what's what's +what's going I'm sorry just what is the + + align:start position:0% +what's going I'm sorry just what is the + + + align:start position:0% +what's going I'm sorry just what is the +Spanish American un I was so kind of czy + + align:start position:0% +Spanish American un I was so kind of czy + + + align:start position:0% +Spanish American un I was so kind of czy +at the end like what like it's not like + + align:start position:0% +at the end like what like it's not like + + + align:start position:0% +at the end like what like it's not like +is it it's not like when you are + + align:start position:0% +is it it's not like when you are + + + align:start position:0% +is it it's not like when you are +Citizens Council it's + + align:start position:0% +Citizens Council it's + + + align:start position:0% +Citizens Council it's +it it is a Social Service + + align:start position:0% +it it is a Social Service + + + align:start position:0% +it it is a Social Service +Agency uh and it's independent of the + + align:start position:0% +Agency uh and it's independent of the + + + align:start position:0% +Agency uh and it's independent of the +new North Citizens Council the New York + + align:start position:0% +new North Citizens Council the New York + + + align:start position:0% +new North Citizens Council the New York +Citizens Council actually has uh a much + + align:start position:0% +Citizens Council actually has uh a much + + + align:start position:0% +Citizens Council actually has uh a much +more + + align:start position:0% +more + + + align:start position:0% +more +uh you know it has kind of an official + + align:start position:0% +uh you know it has kind of an official + + + align:start position:0% +uh you know it has kind of an official +role around its you know because of it's + + align:start position:0% +role around its you know because of it's + + + align:start position:0% +role around its you know because of it's +elected representative organization and + + align:start position:0% +elected representative organization and + + + align:start position:0% +elected representative organization and +what it does and it's tied into state + + align:start position:0% +what it does and it's tied into state + + + align:start position:0% +what it does and it's tied into state +government around how it gets funds and + + align:start position:0% +government around how it gets funds and + + + align:start position:0% +government around how it gets funds and +stuff like that Spanish American Union + + align:start position:0% +stuff like that Spanish American Union + + + align:start position:0% +stuff like that Spanish American Union +is very independent organization it does + + align:start position:0% +is very independent organization it does + + + align:start position:0% +is very independent organization it does +on Social Service side does some of the + + align:start position:0% +on Social Service side does some of the + + + align:start position:0% +on Social Service side does some of the +same kinds of things so it focused very + + align:start position:0% +same kinds of things so it focused very + + + align:start position:0% +same kinds of things so it focused very +heavily in two areas uh one was + + align:start position:0% +heavily in two areas uh one was + + + align:start position:0% +heavily in two areas uh one was +providing uh support for elders and the + + align:start position:0% +providing uh support for elders and the + + + align:start position:0% +providing uh support for elders and the +other was the training and + + align:start position:0% +other was the training and + + + align:start position:0% +other was the training and +preparation uh and certification of + + align:start position:0% +preparation uh and certification of + + + align:start position:0% +preparation uh and certification of +childcare workers in the community they + + align:start position:0% +childcare workers in the community they + + + align:start position:0% +childcare workers in the community they +had a whole program around there as a + + align:start position:0% +had a whole program around there as a + + + align:start position:0% +had a whole program around there as a +matter of fact they had developed a + + align:start position:0% +matter of fact they had developed a + + + align:start position:0% +matter of fact they had developed a +whole Spanish language program for + + align:start position:0% +whole Spanish language program for + + + align:start position:0% +whole Spanish language program for +actually training people to get uh + + align:start position:0% +actually training people to get uh + + + align:start position:0% +actually training people to get uh +certified as child care workers uh under + + align:start position:0% +certified as child care workers uh under + + + align:start position:0% +certified as child care workers uh under +the old director + + align:start position:0% +the old director + + + align:start position:0% +the old director +uh when the the last bust happened in + + align:start position:0% +uh when the the last bust happened in + + + align:start position:0% +uh when the the last bust happened in +the uh economy and there was all the + + align:start position:0% +the uh economy and there was all the + + + align:start position:0% +the uh economy and there was all the +cuts five years ago four years ago from + + align:start position:0% +cuts five years ago four years ago from + + + align:start position:0% +cuts five years ago four years ago from +the state I can't remember the dates or + + align:start position:0% +the state I can't remember the dates or + + + align:start position:0% +the state I can't remember the dates or +anything but uh they lost almost all + + align:start position:0% +anything but uh they lost almost all + + + align:start position:0% +anything but uh they lost almost all +their + + align:start position:0% +their + + + align:start position:0% +their +funding and so they became like a + + align:start position:0% +funding and so they became like a + + + align:start position:0% +funding and so they became like a +dormant institution in some sense kept + + align:start position:0% +dormant institution in some sense kept + + + align:start position:0% +dormant institution in some sense kept +together by the board only uh existing + + align:start position:0% +together by the board only uh existing + + + align:start position:0% +together by the board only uh existing +they weren't really running any programs + + align:start position:0% +they weren't really running any programs + + + align:start position:0% +they weren't really running any programs +and now they're trying to come back and + + align:start position:0% +and now they're trying to come back and + + + align:start position:0% +and now they're trying to come back and +I think they're searching for + + align:start position:0% +I think they're searching for + + + align:start position:0% +I think they're searching for +what kind of organization they're going + + align:start position:0% +what kind of organization they're going + + + align:start position:0% +what kind of organization they're going +to be and what what can they be as an + + align:start position:0% +to be and what what can they be as an + + + align:start position:0% +to be and what what can they be as an +organization that's going to let them + + align:start position:0% +organization that's going to let them + + + align:start position:0% +organization that's going to let them +sustain themselves I did get the + + align:start position:0% +sustain themselves I did get the + + + align:start position:0% +sustain themselves I did get the +impression that they're very + + align:start position:0% +impression that they're very + + + align:start position:0% +impression that they're very +oriented in + + align:start position:0% +oriented in + + + align:start position:0% +oriented in +towards State grant funding and that + + align:start position:0% +towards State grant funding and that + + + align:start position:0% +towards State grant funding and that +finding opportunities for State Grand + + align:start position:0% +finding opportunities for State Grand + + + align:start position:0% +finding opportunities for State Grand +funding you know he had talked about uh + + align:start position:0% +funding you know he had talked about uh + + + align:start position:0% +funding you know he had talked about uh +doing a lot of work now around tobacco + + align:start position:0% +doing a lot of work now around tobacco + + + align:start position:0% +doing a lot of work now around tobacco +prevention smoking + + align:start position:0% +prevention smoking + + + align:start position:0% +prevention smoking +prevention I I think because there was + + align:start position:0% +prevention I I think because there was + + + align:start position:0% +prevention I I think because there was +funding available from the the + + align:start position:0% +funding available from the the + + + align:start position:0% +funding available from the the +settlements with the tobacco industry + + align:start position:0% +settlements with the tobacco industry + + + align:start position:0% +settlements with the tobacco industry +and stuff like that so I I did get the + + align:start position:0% +and stuff like that so I I did get the + + + align:start position:0% +and stuff like that so I I did get the +sense they were sort of in a more + + align:start position:0% +sense they were sort of in a more + + + align:start position:0% +sense they were sort of in a more +opportunistic mode right now based on + + align:start position:0% +opportunistic mode right now based on + + + align:start position:0% +opportunistic mode right now based on +where they could get + + align:start position:0% + + + + align:start position:0% + +funded it's a 20 year something like a + + align:start position:0% +funded it's a 20 year something like a + + + align:start position:0% +funded it's a 20 year something like a +20-year funding + + align:start position:0% +20-year funding + + + align:start position:0% +20-year funding +stream I'm asking about this is the New + + align:start position:0% +stream I'm asking about this is the New + + + align:start position:0% +stream I'm asking about this is the New +York + + align:start position:0% +York + + + align:start position:0% +York +State cbos and cbcs can get the money to + + align:start position:0% +State cbos and cbcs can get the money to + + + align:start position:0% +State cbos and cbcs can get the money to +sign people up for subsidized health + + align:start position:0% +sign people up for subsidized health + + + align:start position:0% +sign people up for subsidized health +insurance + + align:start position:0% +insurance + + + align:start position:0% +insurance +that all comes out yeah each State's + + align:start position:0% +that all comes out yeah each State's + + + align:start position:0% +that all comes out yeah each State's +using that money + + align:start position:0% + + + + align:start position:0% + +differently yeah I mean there's a + + align:start position:0% +differently yeah I mean there's a + + + align:start position:0% +differently yeah I mean there's a +there's a long-term funding stream but + + align:start position:0% +there's a long-term funding stream but + + + align:start position:0% +there's a long-term funding stream but +I'm not really sure where how in + + align:start position:0% +I'm not really sure where how in + + + align:start position:0% +I'm not really sure where how in +Massachusetts that's + + align:start position:0% + + + + align:start position:0% + +that's I I thought it was kind of ironic + + align:start position:0% +that's I I thought it was kind of ironic + + + align:start position:0% +that's I I thought it was kind of ironic +that that they were doing so much anti + + align:start position:0% +that that they were doing so much anti + + + align:start position:0% +that that they were doing so much anti +tobacco stuff cuz everyone was saying + + align:start position:0% +tobacco stuff cuz everyone was saying + + + align:start position:0% +tobacco stuff cuz everyone was saying +that a lot of the migrant workers in the + + align:start position:0% +that a lot of the migrant workers in the + + + align:start position:0% +that a lot of the migrant workers in the +area work in the + + align:start position:0% + + + + align:start position:0% + +there's actually + + align:start position:0% + + + + align:start position:0% + +uh it's too bad when we're in the health + + align:start position:0% +uh it's too bad when we're in the health + + + align:start position:0% +uh it's too bad when we're in the health +CL we didn't meet in the community room + + align:start position:0% +CL we didn't meet in the community room + + + align:start position:0% +CL we didn't meet in the community room +because it's actually a huge display up + + align:start position:0% +because it's actually a huge display up + + + align:start position:0% +because it's actually a huge display up +on the wall they have about the health + + align:start position:0% +on the wall they have about the health + + + align:start position:0% +on the wall they have about the health +hazards of tobacco uh working the + + align:start position:0% +hazards of tobacco uh working the + + + align:start position:0% +hazards of tobacco uh working the +tobacco Fields + + align:start position:0% +tobacco Fields + + + align:start position:0% +tobacco Fields +smoking and everything like that and yet + + align:start position:0% +smoking and everything like that and yet + + + align:start position:0% +smoking and everything like that and yet +if you say that's where kind of a lot of + + align:start position:0% +if you say that's where kind of a lot of + + + align:start position:0% +if you say that's where kind of a lot of +people work they actually have a photo + + align:start position:0% +people work they actually have a photo + + + align:start position:0% +people work they actually have a photo +of Clinton standing in front of that + + align:start position:0% +of Clinton standing in front of that + + + align:start position:0% +of Clinton standing in front of that +sign and Jeff K saying I'm gonna send + + align:start position:0% +sign and Jeff K saying I'm gonna send + + + align:start position:0% +sign and Jeff K saying I'm gonna send +him a picture of that and then the one + + align:start position:0% +him a picture of that and then the one + + + align:start position:0% +him a picture of that and then the one +of him in the official you know cigar + + align:start position:0% +of him in the official you know cigar + + + align:start position:0% +of him in the official you know cigar +offici Auto + + align:start position:0% + + + + align:start position:0% + +magazine send it to him and remind + + align:start position:0% + + + + align:start position:0% + +him so anyway coming back to this issue + + align:start position:0% +him so anyway coming back to this issue + + + align:start position:0% +him so anyway coming back to this issue +of of populationbased + + align:start position:0% +of of populationbased + + + align:start position:0% +of of populationbased +approach um I thought it'd be useful to + + align:start position:0% +approach um I thought it'd be useful to + + + align:start position:0% +approach um I thought it'd be useful to +spend a little bit of time sort of + + align:start position:0% +spend a little bit of time sort of + + + align:start position:0% +spend a little bit of time sort of +talking about whether a what do you + + align:start position:0% +talking about whether a what do you + + + align:start position:0% +talking about whether a what do you +think that concept's useful um in + + align:start position:0% +think that concept's useful um in + + + align:start position:0% +think that concept's useful um in +thinking about or approach to Economic + + align:start position:0% +thinking about or approach to Economic + + + align:start position:0% +thinking about or approach to Economic +Development and if so what might it + + align:start position:0% +Development and if so what might it + + + align:start position:0% +Development and if so what might it +suggest about about how we might frame + + align:start position:0% +suggest about about how we might frame + + + align:start position:0% +suggest about about how we might frame +our war I don't know what + + align:start position:0% + + + + align:start position:0% + +it well let me let me give my + + align:start position:0% +it well let me let me give my + + + align:start position:0% +it well let me let me give my +interpretation of it I I I interpret it + + align:start position:0% +interpretation of it I I I interpret it + + + align:start position:0% +interpretation of it I I I interpret it +to mean that um you know a commitment to + + align:start position:0% +to mean that um you know a commitment to + + + align:start position:0% +to mean that um you know a commitment to +improve outcomes for as many people in + + align:start position:0% +improve outcomes for as many people in + + + align:start position:0% +improve outcomes for as many people in +the community as + + align:start position:0% +the community as + + + align:start position:0% +the community as +possible um and that the way that's + + align:start position:0% +possible um and that the way that's + + + align:start position:0% +possible um and that the way that's +being + + align:start position:0% +being + + + align:start position:0% +being +implemented is through neon and that's + + align:start position:0% +implemented is through neon and that's + + + align:start position:0% +implemented is through neon and that's +through actually trying + + align:start position:0% +through actually trying + + + align:start position:0% +through actually trying +to develop a relationship with everyone + + align:start position:0% +to develop a relationship with everyone + + + align:start position:0% +to develop a relationship with everyone +in the community be able to sort of + + align:start position:0% +in the community be able to sort of + + + align:start position:0% +in the community be able to sort of +reach out to every household and + + align:start position:0% +reach out to every household and + + + align:start position:0% +reach out to every household and +understand what their health needs are + + align:start position:0% +understand what their health needs are + + + align:start position:0% +understand what their health needs are +understand what services might be + + align:start position:0% +understand what services might be + + + align:start position:0% +understand what services might be +available to address those Health needs + + align:start position:0% +available to address those Health needs + + + align:start position:0% +available to address those Health needs +and sort of connect them up to them + + align:start position:0% +and sort of connect them up to them + + + align:start position:0% +and sort of connect them up to them +so I mean at least two aspects of that + + align:start position:0% +so I mean at least two aspects of that + + + align:start position:0% +so I mean at least two aspects of that +seem useful at least uh important one + + align:start position:0% +seem useful at least uh important one + + + align:start position:0% +seem useful at least uh important one +the sort of notion that you're really + + align:start position:0% +the sort of notion that you're really + + + align:start position:0% +the sort of notion that you're really +trying to to measure outcomes not just + + align:start position:0% +trying to to measure outcomes not just + + + align:start position:0% +trying to to measure outcomes not just +uh you know by for a small segment but + + align:start position:0% +uh you know by for a small segment but + + + align:start position:0% +uh you know by for a small segment but +how everyone's conditions improved and + + align:start position:0% +how everyone's conditions improved and + + + align:start position:0% +how everyone's conditions improved and +the idea of of of having this Service + + align:start position:0% +the idea of of of having this Service + + + align:start position:0% +the idea of of of having this Service +delivery model where you actually have + + align:start position:0% +delivery model where you actually have + + + align:start position:0% +delivery model where you actually have +relationships with everyone in the + + align:start position:0% +relationships with everyone in the + + + align:start position:0% +relationships with everyone in the +community you really try and have an + + align:start position:0% +community you really try and have an + + + align:start position:0% +community you really try and have an +Outreach Network that can try and + + align:start position:0% +Outreach Network that can try and + + + align:start position:0% +Outreach Network that can try and +connect now I don't I know you've said + + align:start position:0% +connect now I don't I know you've said + + + align:start position:0% +connect now I don't I know you've said +in the past that really only only about + + align:start position:0% +in the past that really only only about + + + align:start position:0% +in the past that really only only about +40% of the people have actually + + align:start position:0% +40% of the people have actually + + + align:start position:0% +40% of the people have actually +participated in a meaningful way in that + + align:start position:0% +participated in a meaningful way in that + + + align:start position:0% +participated in a meaningful way in that +so they're not to they're not to 100% at + + align:start position:0% +so they're not to they're not to 100% at + + + align:start position:0% +so they're not to they're not to 100% at +this point yeah I think there's other + + align:start position:0% +this point yeah I think there's other + + + align:start position:0% +this point yeah I think there's other +couple of things two ways to think about + + align:start position:0% +couple of things two ways to think about + + + align:start position:0% +couple of things two ways to think about +it one is + + align:start position:0% +it one is + + + align:start position:0% +it one is +that uh and I me you said this quite + + align:start position:0% +that uh and I me you said this quite + + + align:start position:0% +that uh and I me you said this quite +clear but it's the the kind of indicator + + align:start position:0% +clear but it's the the kind of indicator + + + align:start position:0% +clear but it's the the kind of indicator +of + + align:start position:0% +of + + + align:start position:0% +of +success for them and the indicators for + + align:start position:0% +success for them and the indicators for + + + align:start position:0% +success for them and the indicators for +Progress are not based on who they serve + + align:start position:0% +Progress are not based on who they serve + + + align:start position:0% +Progress are not based on who they serve +but who resides in the community so it's + + align:start position:0% +but who resides in the community so it's + + + align:start position:0% +but who resides in the community so it's +a very different model because most + + align:start position:0% +a very different model because most + + + align:start position:0% +a very different model because most +people kind of think about look if + + align:start position:0% +people kind of think about look if + + + align:start position:0% +people kind of think about look if +we if we if we Service as a clinic for + + align:start position:0% +we if we if we Service as a clinic for + + + align:start position:0% +we if we if we Service as a clinic for +example 100 people and 80% of them get + + align:start position:0% +example 100 people and 80% of them get + + + align:start position:0% +example 100 people and 80% of them get +well we're doing a good job but their + + align:start position:0% +well we're doing a good job but their + + + align:start position:0% +well we're doing a good job but their +notion is because they have this + + align:start position:0% +notion is because they have this + + + align:start position:0% +notion is because they have this +population B if we serve a 100 people + + align:start position:0% +population B if we serve a 100 people + + + align:start position:0% +population B if we serve a 100 people +and and 80% get well but there 300 we're + + align:start position:0% +and and 80% get well but there 300 we're + + + align:start position:0% +and and 80% get well but there 300 we're +not serving then we're not doing a good + + align:start position:0% +not serving then we're not doing a good + + + align:start position:0% +not serving then we're not doing a good +job so they have a it's a different you + + align:start position:0% +job so they have a it's a different you + + + align:start position:0% +job so they have a it's a different you +kind of cast a broader net of how you + + align:start position:0% +kind of cast a broader net of how you + + + align:start position:0% +kind of cast a broader net of how you +kind of + + align:start position:0% +kind of + + + align:start position:0% +kind of +measure uh what you're paying attention + + align:start position:0% +measure uh what you're paying attention + + + align:start position:0% +measure uh what you're paying attention +to as an indicator of success the other + + align:start position:0% +to as an indicator of success the other + + + align:start position:0% +to as an indicator of success the other +part that they talk about is where you + + align:start position:0% +part that they talk about is where you + + + align:start position:0% +part that they talk about is where you +put your emphasis on + + align:start position:0% +put your emphasis on + + + align:start position:0% +put your emphasis on +uh on your strategy for doing that + + align:start position:0% +uh on your strategy for doing that + + + align:start position:0% +uh on your strategy for doing that +and part of that is an assumption that + + align:start position:0% +and part of that is an assumption that + + + align:start position:0% +and part of that is an assumption that +you need to figure out why the people + + align:start position:0% +you need to figure out why the people + + + align:start position:0% +you need to figure out why the people +who are disconnected or disconnected and + + align:start position:0% +who are disconnected or disconnected and + + + align:start position:0% +who are disconnected or disconnected and +how do you kind of bring + + align:start position:0% +how do you kind of bring + + + align:start position:0% +how do you kind of bring +them you know if you have 300 people who + + align:start position:0% +them you know if you have 300 people who + + + align:start position:0% +them you know if you have 300 people who +are aren't serving and really trying to + + align:start position:0% +are aren't serving and really trying to + + + align:start position:0% +are aren't serving and really trying to +understand how you connect and really + + align:start position:0% +understand how you connect and really + + + align:start position:0% +understand how you connect and really +bring them into what you're doing with + + align:start position:0% +bring them into what you're doing with + + + align:start position:0% +bring them into what you're doing with +some assumption that you have a way of + + align:start position:0% +some assumption that you have a way of + + + align:start position:0% +some assumption that you have a way of +knowing how to do what you do in a good + + align:start position:0% +knowing how to do what you do in a good + + + align:start position:0% +knowing how to do what you do in a good +way so it works quite well in the + + align:start position:0% +way so it works quite well in the + + + align:start position:0% +way so it works quite well in the +medical work because they actually they + + align:start position:0% +medical work because they actually they + + + align:start position:0% +medical work because they actually they +know how to provide care and so if they + + align:start position:0% +know how to provide care and so if they + + + align:start position:0% +know how to provide care and so if they +can get people into the + + align:start position:0% +can get people into the + + + align:start position:0% +can get people into the +system then they can do a lot for + + align:start position:0% +system then they can do a lot for + + + align:start position:0% +system then they can do a lot for +them around the economic model is a + + align:start position:0% +them around the economic model is a + + + align:start position:0% +them around the economic model is a +different thing because they don't + + align:start position:0% +different thing because they don't + + + align:start position:0% +different thing because they don't +necessarily have something to get people + + align:start position:0% +necessarily have something to get people + + + align:start position:0% +necessarily have something to get people +into so it may you know present a + + align:start position:0% +into so it may you know present a + + + align:start position:0% +into so it may you know present a +different set of + + align:start position:0% + + + + align:start position:0% + +problems so I think it's much more of a + + align:start position:0% +problems so I think it's much more of a + + + align:start position:0% +problems so I think it's much more of a +strategy of what who you're holding as + + align:start position:0% +strategy of what who you're holding as + + + align:start position:0% +strategy of what who you're holding as +important to pay attention to and how + + align:start position:0% +important to pay attention to and how + + + align:start position:0% +important to pay attention to and how +you kind of + + align:start position:0% +you kind of + + + align:start position:0% +you kind of +measure and what are the indicators you + + align:start position:0% +measure and what are the indicators you + + + align:start position:0% +measure and what are the indicators you +look for for success + + align:start position:0% + + + + align:start position:0% + +about some of + + align:start position:0% +about some of + + + align:start position:0% +about some of +this third world and stories about + + align:start position:0% +this third world and stories about + + + align:start position:0% +this third world and stories about +how they + + align:start position:0% +how they + + + align:start position:0% +how they +found Scholars + + align:start position:0% +found Scholars + + + align:start position:0% +found Scholars +found a really successful cases of + + align:start position:0% +found a really successful cases of + + + align:start position:0% +found a really successful cases of +poverty + + align:start position:0% + + + + align:start position:0% + +deviation were made up of families where + + align:start position:0% +deviation were made up of families where + + + align:start position:0% +deviation were made up of families where +different members of the families did + + align:start position:0% +different members of the families did + + + align:start position:0% +different members of the families did +very + + align:start position:0% +very + + + align:start position:0% +very +differentes some of managment + + align:start position:0% + + + + align:start position:0% + +unfur a men of things that different + + align:start position:0% +unfur a men of things that different + + + align:start position:0% +unfur a men of things that different +members of each household + + align:start position:0% +members of each household + + + align:start position:0% +members of each household +find + + align:start position:0% +find + + + align:start position:0% +find +way to yeah from the household + + align:start position:0% +way to yeah from the household + + + align:start position:0% +way to yeah from the household +perspective right what could be a + + align:start position:0% +perspective right what could be a + + + align:start position:0% +perspective right what could be a +strategy what could be the set of + + align:start position:0% +strategy what could be the set of + + + align:start position:0% +strategy what could be the set of +activities that that you're looking at + + align:start position:0% +activities that that you're looking at + + + align:start position:0% +activities that that you're looking at +as a household might help bring them out + + align:start position:0% +as a household might help bring them out + + + align:start position:0% +as a household might help bring them out +of poverty I'm guessing that it's + + align:start position:0% +of poverty I'm guessing that it's + + + align:start position:0% +of poverty I'm guessing that it's +precisely not just saying that we were + + align:start position:0% +precisely not just saying that we were + + + align:start position:0% +precisely not just saying that we were +able to + + align:start position:0% +able to + + + align:start position:0% +able to +create + + align:start position:0% +create + + + align:start position:0% +create +100 jobs for people for the community + + align:start position:0% +100 jobs for people for the community + + + align:start position:0% +100 jobs for people for the community +then the community the nature of that + + align:start position:0% +then the community the nature of that + + + align:start position:0% +then the community the nature of that +work for bringing home $5,000 a year + + align:start position:0% +work for bringing home $5,000 a year + + + align:start position:0% +work for bringing home $5,000 a year +that brought 100 + + align:start position:0% + + + + align:start position:0% + +households could be a it could be a + + align:start position:0% +households could be a it could be a + + + align:start position:0% +households could be a it could be a +difference yeah that is a very different + + align:start position:0% + + + + align:start position:0% + +approach thoughts about any + + align:start position:0% +approach thoughts about any + + + align:start position:0% +approach thoughts about any +is this useful how might it be + + align:start position:0% +is this useful how might it be + + + align:start position:0% +is this useful how might it be +useful or is it really + + align:start position:0% +useful or is it really + + + align:start position:0% +useful or is it really +outside the way we should be thinking + + align:start position:0% +outside the way we should be thinking + + + align:start position:0% +outside the way we should be thinking +about Economic + + align:start position:0% + + + + align:start position:0% + +Development the Alterna taking more + + align:start position:0% +Development the Alterna taking more + + + align:start position:0% +Development the Alterna taking more +macro approach + + align:start position:0% +macro approach + + + align:start position:0% +macro approach +looking is that kind like I guess I'm + + align:start position:0% +looking is that kind like I guess I'm + + + align:start position:0% +looking is that kind like I guess I'm +looking I mean this this feels very + + align:start position:0% +looking I mean this this feels very + + + align:start position:0% +looking I mean this this feels very +intuitive do + + align:start position:0% +intuitive do + + + align:start position:0% +intuitive do +this iess how do + + align:start position:0% +this iess how do + + + align:start position:0% +this iess how do +you that even that they couple with + + align:start position:0% +you that even that they couple with + + + align:start position:0% +you that even that they couple with +other + + align:start position:0% +other + + + align:start position:0% +other +approaches because it's it strikes me + + align:start position:0% +approaches because it's it strikes me + + + align:start position:0% +approaches because it's it strikes me +someone interesting because the list of + + align:start position:0% +someone interesting because the list of + + + align:start position:0% +someone interesting because the list of +projects that they give us doesn't + + align:start position:0% +projects that they give us doesn't + + + align:start position:0% +projects that they give us doesn't +really + + align:start position:0% +really + + + align:start position:0% +really +connect at least explicitly with the + + align:start position:0% +connect at least explicitly with the + + + align:start position:0% +connect at least explicitly with the +sort of population approach I mean they + + align:start position:0% +sort of population approach I mean they + + + align:start position:0% +sort of population approach I mean they +may have + + align:start position:0% +may have + + + align:start position:0% +may have +connections in their mind somewhere but + + align:start position:0% +connections in their mind somewhere but + + + align:start position:0% +connections in their mind somewhere but +I mean you know um creating a creating a + + align:start position:0% +I mean you know um creating a creating a + + + align:start position:0% +I mean you know um creating a creating a +d a destination for people outside the + + align:start position:0% +d a destination for people outside the + + + align:start position:0% +d a destination for people outside the +community well where is the connection + + align:start position:0% +community well where is the connection + + + align:start position:0% +community well where is the connection +of that to the improved outcomes to + + align:start position:0% +of that to the improved outcomes to + + + align:start position:0% +of that to the improved outcomes to +people in the community now there might + + align:start position:0% +people in the community now there might + + + align:start position:0% +people in the community now there might +be a set of assumptions playing out in + + align:start position:0% +be a set of assumptions playing out in + + + align:start position:0% +be a set of assumptions playing out in +people's mind about it um um or reusing + + align:start position:0% +people's mind about it um um or reusing + + + align:start position:0% +people's mind about it um um or reusing +vacant buildings or things like that + + align:start position:0% +vacant buildings or things like that + + + align:start position:0% +vacant buildings or things like that +they don't they haven't their thinking + + align:start position:0% +they don't they haven't their thinking + + + align:start position:0% +they don't they haven't their thinking +hasn't started from + + align:start position:0% +hasn't started from + + + align:start position:0% +hasn't started from +okay what are the what are the the + + align:start position:0% +okay what are the what are the the + + + align:start position:0% +okay what are the what are the the +challenges to improving incomes of of + + align:start position:0% +challenges to improving incomes of of + + + align:start position:0% +challenges to improving incomes of of +the people we're working with what what + + align:start position:0% +the people we're working with what what + + + align:start position:0% +the people we're working with what what +the set of of economic opportunities + + align:start position:0% +the set of of economic opportunities + + + align:start position:0% +the set of of economic opportunities +that might support that I guess maybe + + align:start position:0% +that might support that I guess maybe + + + align:start position:0% +that might support that I guess maybe +Peter conception might be closest to + + align:start position:0% +Peter conception might be closest to + + + align:start position:0% +Peter conception might be closest to +that and then he's looking at the at the + + align:start position:0% +that and then he's looking at the at the + + + align:start position:0% +that and then he's looking at the at the +entrepreneurial activity around that um + + align:start position:0% +entrepreneurial activity around that um + + + align:start position:0% +entrepreneurial activity around that um +so um the thing that really struck me + + align:start position:0% +so um the thing that really struck me + + + align:start position:0% +so um the thing that really struck me +about it is that in a lot of the + + align:start position:0% +about it is that in a lot of the + + + align:start position:0% +about it is that in a lot of the +literature about at least obstacles to + + align:start position:0% +literature about at least obstacles to + + + align:start position:0% +literature about at least obstacles to +employment um in in poor households and + + align:start position:0% +employment um in in poor households and + + + align:start position:0% +employment um in in poor households and +especially households where you have you + + align:start position:0% +especially households where you have you + + + align:start position:0% +especially households where you have you +know multigenerational poverty and and + + align:start position:0% +know multigenerational poverty and and + + + align:start position:0% +know multigenerational poverty and and +um low educational attainment is that + + align:start position:0% +um low educational attainment is that + + + align:start position:0% +um low educational attainment is that +there are there are very complicated + + align:start position:0% +there are there are very complicated + + + align:start position:0% +there are there are very complicated +obstacles and Myriad obstacles to + + align:start position:0% +obstacles and Myriad obstacles to + + + align:start position:0% +obstacles and Myriad obstacles to +employment that include you know + + align:start position:0% +employment that include you know + + + align:start position:0% +employment that include you know +language barriers Health barriers um + + align:start position:0% +language barriers Health barriers um + + + align:start position:0% +language barriers Health barriers um +education um child care you know some + + align:start position:0% +education um child care you know some + + + align:start position:0% +education um child care you know some +sometimes + + align:start position:0% +sometimes + + + align:start position:0% +sometimes +Transportation um and that um you know + + align:start position:0% +Transportation um and that um you know + + + align:start position:0% +Transportation um and that um you know +getting those people in in employment + + align:start position:0% +getting those people in in employment + + + align:start position:0% +getting those people in in employment +and staying in employment and then + + align:start position:0% +and staying in employment and then + + + align:start position:0% +and staying in employment and then +ultimately moving up to higher level + + align:start position:0% +ultimately moving up to higher level + + + align:start position:0% +ultimately moving up to higher level +incomes requires a pretty um um strong + + align:start position:0% +incomes requires a pretty um um strong + + + align:start position:0% +incomes requires a pretty um um strong +involvement with them and you often a + + align:start position:0% +involvement with them and you often a + + + align:start position:0% +involvement with them and you often a +complicated mix of services so it did + + align:start position:0% +complicated mix of services so it did + + + align:start position:0% +complicated mix of services so it did +strike me that least in that you know + + align:start position:0% +strike me that least in that you know + + + align:start position:0% +strike me that least in that you know +some of the same issues they're facing + + align:start position:0% +some of the same issues they're facing + + + align:start position:0% +some of the same issues they're facing +around Healthcare in terms of the + + align:start position:0% +around Healthcare in terms of the + + + align:start position:0% +around Healthcare in terms of the +obstacles of getting people connected to + + align:start position:0% +obstacles of getting people connected to + + + align:start position:0% +obstacles of getting people connected to +healthare um are probably there on on + + align:start position:0% +healthare um are probably there on on + + + align:start position:0% +healthare um are probably there on on +the employment side and and I would + + align:start position:0% +the employment side and and I would + + + align:start position:0% +the employment side and and I would +imagine even on the small business + + align:start position:0% +imagine even on the small business + + + align:start position:0% +imagine even on the small business +development side that some of those same + + align:start position:0% +development side that some of those same + + + align:start position:0% +development side that some of those same +issues and obstacles + + align:start position:0% +issues and obstacles + + + align:start position:0% +issues and obstacles +you know are going to get in the way so + + align:start position:0% +you know are going to get in the way so + + + align:start position:0% +you know are going to get in the way so +I do think there's some potential + + align:start position:0% +I do think there's some potential + + + align:start position:0% +I do think there's some potential +analogy even though the system's very + + align:start position:0% +analogy even though the system's very + + + align:start position:0% +analogy even though the system's very +different you know there there isn't + + align:start position:0% +different you know there there isn't + + + align:start position:0% +different you know there there isn't +there isn't a health care delivery + + align:start position:0% +there isn't a health care delivery + + + align:start position:0% +there isn't a health care delivery +system and an insurance system that at + + align:start position:0% +system and an insurance system that at + + + align:start position:0% +system and an insurance system that at +least makes it a little easier to know + + align:start position:0% +least makes it a little easier to know + + + align:start position:0% +least makes it a little easier to know +what you're trying to connect people to + + align:start position:0% +what you're trying to connect people to + + + align:start position:0% +what you're trying to connect people to +um there isn't a business development + + align:start position:0% +um there isn't a business development + + + align:start position:0% +um there isn't a business development +system that you could plug people into + + align:start position:0% +system that you could plug people into + + + align:start position:0% +system that you could plug people into +with the same type of employment and + + align:start position:0% +with the same type of employment and + + + align:start position:0% +with the same type of employment and +training system is but at least in terms + + align:start position:0% +training system is but at least in terms + + + align:start position:0% +training system is but at least in terms +of the barriers to accessing that + + align:start position:0% +of the barriers to accessing that + + + align:start position:0% +of the barriers to accessing that +opportunity I I think there's going to + + align:start position:0% +opportunity I I think there's going to + + + align:start position:0% +opportunity I I think there's going to +be some analogies to what they've + + align:start position:0% +be some analogies to what they've + + + align:start position:0% +be some analogies to what they've +learned um on on the healthc care side + + align:start position:0% +learned um on on the healthc care side + + + align:start position:0% +learned um on on the healthc care side +um that's translation translatable um I + + align:start position:0% +um that's translation translatable um I + + + align:start position:0% +um that's translation translatable um I +think the other thing too is it does it + + align:start position:0% +think the other thing too is it does it + + + align:start position:0% +think the other thing too is it does it +gives us at least one potential screen + + align:start position:0% +gives us at least one potential screen + + + align:start position:0% +gives us at least one potential screen +to think about as we look at these ideas + + align:start position:0% +to think about as we look at these ideas + + + align:start position:0% +to think about as we look at these ideas +and these proposals which is how do we + + align:start position:0% +and these proposals which is how do we + + + align:start position:0% +and these proposals which is how do we +see + + align:start position:0% +see + + + align:start position:0% +see +them actually improving economic + + align:start position:0% +them actually improving economic + + + align:start position:0% +them actually improving economic +outcomes for the residents of the + + align:start position:0% +outcomes for the residents of the + + + align:start position:0% +outcomes for the residents of the +neighborhood that that should be a + + align:start position:0% +neighborhood that that should be a + + + align:start position:0% +neighborhood that that should be a +screen where thinking about um in + + align:start position:0% +screen where thinking about um in + + + align:start position:0% +screen where thinking about um in +deciding which activities to focus on + + align:start position:0% +deciding which activities to focus on + + + align:start position:0% +deciding which activities to focus on +you know we should be able to make a + + align:start position:0% +you know we should be able to make a + + + align:start position:0% +you know we should be able to make a +case um about how these activities will + + align:start position:0% +case um about how these activities will + + + align:start position:0% +case um about how these activities will +generate improved outcomes for people in + + align:start position:0% +generate improved outcomes for people in + + + align:start position:0% +generate improved outcomes for people in +the community you know we we should be + + align:start position:0% +the community you know we we should be + + + align:start position:0% +the community you know we we should be +uh or thinking about how our plan will + + align:start position:0% +uh or thinking about how our plan will + + + align:start position:0% +uh or thinking about how our plan will +help connect those activities to ways + + align:start position:0% +help connect those activities to ways + + + align:start position:0% +help connect those activities to ways +that will will lead to improve outcomes + + align:start position:0% +that will will lead to improve outcomes + + + align:start position:0% +that will will lead to improve outcomes +of residence since that's that's their + + align:start position:0% +of residence since that's that's their + + + align:start position:0% +of residence since that's that's their +overriding objective you know I think we + + align:start position:0% +overriding objective you know I think we + + + align:start position:0% +overriding objective you know I think we +need to to be applying that lens to what + + align:start position:0% +need to to be applying that lens to what + + + align:start position:0% +need to to be applying that lens to what +we're thinking about doing + + align:start position:0% +we're thinking about doing + + + align:start position:0% +we're thinking about doing +yeah I think you know in my mind is you + + align:start position:0% +yeah I think you know in my mind is you + + + align:start position:0% +yeah I think you know in my mind is you +know if you take this population base + + align:start position:0% +know if you take this population base + + + align:start position:0% +know if you take this population base +that's very active you know you're not + + align:start position:0% +that's very active you know you're not + + + align:start position:0% +that's very active you know you're not +doing door knocking and in the way I'm + + align:start position:0% +doing door knocking and in the way I'm + + + align:start position:0% +doing door knocking and in the way I'm +thinking maybe it's just another added + + align:start position:0% +thinking maybe it's just another added + + + align:start position:0% +thinking maybe it's just another added +component so they have this health care + + align:start position:0% +component so they have this health care + + + align:start position:0% +component so they have this health care +or Social Service kind of component now + + align:start position:0% +or Social Service kind of component now + + + align:start position:0% +or Social Service kind of component now +it's kind of like maybe that's the first + + align:start position:0% +it's kind of like maybe that's the first + + + align:start position:0% +it's kind of like maybe that's the first +layer and then Economic Development + + align:start position:0% +layer and then Economic Development + + + align:start position:0% +layer and then Economic Development +comes on top of that and so it's + + align:start position:0% +comes on top of that and so it's + + + align:start position:0% +comes on top of that and so it's +connecting you know um you know talked + + align:start position:0% +connecting you know um you know talked + + + align:start position:0% +connecting you know um you know talked +with some folks that that work um in uh + + align:start position:0% +with some folks that that work um in uh + + + align:start position:0% +with some folks that that work um in uh +kind of career uh computer centers for + + align:start position:0% +kind of career uh computer centers for + + + align:start position:0% +kind of career uh computer centers for +cdcs and and they often say you know + + align:start position:0% +cdcs and and they often say you know + + + align:start position:0% +cdcs and and they often say you know +we're we're going to meet people where + + align:start position:0% +we're we're going to meet people where + + + align:start position:0% +we're we're going to meet people where +they're at and uh so it's really kind of + + align:start position:0% +they're at and uh so it's really kind of + + + align:start position:0% +they're at and uh so it's really kind of +taking stock of where someone's at um + + align:start position:0% +taking stock of where someone's at um + + + align:start position:0% +taking stock of where someone's at um +based on their skills based on their + + align:start position:0% +based on their skills based on their + + + align:start position:0% +based on their skills based on their +their just kind of their emotions and + + align:start position:0% +their just kind of their emotions and + + + align:start position:0% +their just kind of their emotions and +their thinking about themselves and + + align:start position:0% +their thinking about themselves and + + + align:start position:0% +their thinking about themselves and +where their opportunities are and so so + + align:start position:0% +where their opportunities are and so so + + + align:start position:0% +where their opportunities are and so so +you know if it's getting + + align:start position:0% +you know if it's getting + + + align:start position:0% +you know if it's getting +esol program that is getting an esol Pro + + align:start position:0% +esol program that is getting an esol Pro + + + align:start position:0% +esol program that is getting an esol Pro +program so I guess it's you know and + + align:start position:0% +program so I guess it's you know and + + + align:start position:0% +program so I guess it's you know and +there's a framework um uh like the + + align:start position:0% +there's a framework um uh like the + + + align:start position:0% +there's a framework um uh like the +self-sufficiency framework I don't know + + align:start position:0% +self-sufficiency framework I don't know + + + align:start position:0% +self-sufficiency framework I don't know +if if people have have looked at that + + align:start position:0% +if if people have have looked at that + + + align:start position:0% +if if people have have looked at that +but that's a that's something that's + + align:start position:0% +but that's a that's something that's + + + align:start position:0% +but that's a that's something that's +been developed in the in the state of + + align:start position:0% +been developed in the in the state of + + + align:start position:0% +been developed in the in the state of +the work in the Workforce Development + + align:start position:0% +the work in the Workforce Development + + + align:start position:0% +the work in the Workforce Development +world that it's really kind of career + + align:start position:0% +world that it's really kind of career + + + align:start position:0% +world that it's really kind of career +development is is a stepped process and + + align:start position:0% +development is is a stepped process and + + + align:start position:0% +development is is a stepped process and +people go through stages so um it might + + align:start position:0% +people go through stages so um it might + + + align:start position:0% +people go through stages so um it might +be useful to kind of apply that to to + + align:start position:0% +be useful to kind of apply that to to + + + align:start position:0% +be useful to kind of apply that to to +the kind of population population + + align:start position:0% + + + + align:start position:0% + +base com observation \ No newline at end of file diff --git a/NnDqJhtUqjw.txt b/NnDqJhtUqjw.txt new file mode 100644 index 0000000000000000000000000000000000000000..ae442a6b73861501e119ee0e2d38f9ac7a21a94c --- /dev/null +++ b/NnDqJhtUqjw.txt @@ -0,0 +1,15475 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit MIT opencourseware + + align:start position:0% +of MIT courses visit MIT opencourseware + + + align:start position:0% +of MIT courses visit MIT opencourseware +at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu today what we're going to do + + align:start position:0% +ocw.mit.edu today what we're going to do + + + align:start position:0% +ocw.mit.edu today what we're going to do +is uh is we're going to finish off our + + align:start position:0% +is uh is we're going to finish off our + + + align:start position:0% +is uh is we're going to finish off our +discussion about oscillators in + + align:start position:0% +discussion about oscillators in + + + align:start position:0% +discussion about oscillators in +particular we're going to talk about + + align:start position:0% +particular we're going to talk about + + + align:start position:0% +particular we're going to talk about +alternative designs for oscillators so + + align:start position:0% +alternative designs for oscillators so + + + align:start position:0% +alternative designs for oscillators so +rather than having uh these Loops that + + align:start position:0% +rather than having uh these Loops that + + + align:start position:0% +rather than having uh these Loops that +are purely composed of negative U + + align:start position:0% +are purely composed of negative U + + + align:start position:0% +are purely composed of negative U +negative interactions negative feedback + + align:start position:0% +negative interactions negative feedback + + + align:start position:0% +negative interactions negative feedback +instead we're going to talk about cases + + align:start position:0% +instead we're going to talk about cases + + + align:start position:0% +instead we're going to talk about cases +where you have both positive and + + align:start position:0% +where you have both positive and + + + align:start position:0% +where you have both positive and +negative interactions all right so in + + align:start position:0% +negative interactions all right so in + + + align:start position:0% +negative interactions all right so in +using these uh this kind of combined + + align:start position:0% +using these uh this kind of combined + + + align:start position:0% +using these uh this kind of combined +Network structure you can generate what + + align:start position:0% +Network structure you can generate what + + + align:start position:0% +Network structure you can generate what +are known as relaxation oscillators + + align:start position:0% +are known as relaxation oscillators + + + align:start position:0% +are known as relaxation oscillators +which have uh some really um some + + align:start position:0% +which have uh some really um some + + + align:start position:0% +which have uh some really um some +wonderful properties in particular you + + align:start position:0% +wonderful properties in particular you + + + align:start position:0% +wonderful properties in particular you +can get more robust oscillations + + align:start position:0% +can get more robust oscillations + + + align:start position:0% +can get more robust oscillations +relative to the parameters but also you + + align:start position:0% +relative to the parameters but also you + + + align:start position:0% +relative to the parameters but also you +can uh the the oscillations become + + align:start position:0% +can uh the the oscillations become + + + align:start position:0% +can uh the the oscillations become +tunable I.E you can change the frequency + + align:start position:0% +tunable I.E you can change the frequency + + + align:start position:0% +tunable I.E you can change the frequency +without compromising for example the + + align:start position:0% +without compromising for example the + + + align:start position:0% +without compromising for example the +amplitude of the oscillations right so + + align:start position:0% +amplitude of the oscillations right so + + + align:start position:0% +amplitude of the oscillations right so +for many both uh natural and synthetic + + align:start position:0% +for many both uh natural and synthetic + + + align:start position:0% +for many both uh natural and synthetic +oscillators these these so-called + + align:start position:0% +oscillators these these so-called + + + align:start position:0% +oscillators these these so-called +synthetic oscillators are perhaps uh the + + align:start position:0% +synthetic oscillators are perhaps uh the + + + align:start position:0% +synthetic oscillators are perhaps uh the +way to + + align:start position:0% +way to + + + align:start position:0% +way to +go then we're going to transition to + + align:start position:0% +go then we're going to transition to + + + align:start position:0% +go then we're going to transition to +more of the global structure of U of + + align:start position:0% +more of the global structure of U of + + + align:start position:0% +more of the global structure of U of +some of these uh these networks in the + + align:start position:0% +some of these uh these networks in the + + + align:start position:0% +some of these uh these networks in the +context of transcription networks within + + align:start position:0% +context of transcription networks within + + + align:start position:0% +context of transcription networks within +within cells and and discuss this paper + + align:start position:0% +within cells and and discuss this paper + + + align:start position:0% +within cells and and discuss this paper +that you guys just read the barabasi + + align:start position:0% +that you guys just read the barabasi + + + align:start position:0% +that you guys just read the barabasi +paper which is uh one of the world's + + align:start position:0% +paper which is uh one of the world's + + + align:start position:0% +paper which is uh one of the world's +most cited papers I think right and + + align:start position:0% +most cited papers I think right and + + + align:start position:0% +most cited papers I think right and +um and then and then uh and then after + + align:start position:0% +um and then and then uh and then after + + + align:start position:0% +um and then and then uh and then after +thinking about this Global structure of + + align:start position:0% +thinking about this Global structure of + + + align:start position:0% +thinking about this Global structure of +how you might be able to generate these + + align:start position:0% +how you might be able to generate these + + + align:start position:0% +how you might be able to generate these +so-called power law structures uh we're + + align:start position:0% +so-called power law structures uh we're + + + align:start position:0% +so-called power law structures uh we're +going to look a little bit more detailed + + align:start position:0% +going to look a little bit more detailed + + + align:start position:0% +going to look a little bit more detailed +as that to try to understand something + + align:start position:0% +as that to try to understand something + + + align:start position:0% +as that to try to understand something +about these Network motifs we've already + + align:start position:0% +about these Network motifs we've already + + + align:start position:0% +about these Network motifs we've already +talked about them a little bit in the + + align:start position:0% +talked about them a little bit in the + + + align:start position:0% +talked about them a little bit in the +context of uh Auto regulatory Loops but + + align:start position:0% +context of uh Auto regulatory Loops but + + + align:start position:0% +context of uh Auto regulatory Loops but +now we'll talk about them in in in a + + align:start position:0% +now we'll talk about them in in in a + + + align:start position:0% +now we'll talk about them in in in a +little a little bit more generality in + + align:start position:0% +little a little bit more generality in + + + align:start position:0% +little a little bit more generality in +particular this cont in the context of + + align:start position:0% +particular this cont in the context of + + + align:start position:0% +particular this cont in the context of +feed forward + + align:start position:0% +feed forward + + + align:start position:0% +feed forward +loops and then and then on Thursday we + + align:start position:0% +loops and then and then on Thursday we + + + align:start position:0% +loops and then and then on Thursday we +will get into you know what some of the + + align:start position:0% +will get into you know what some of the + + + align:start position:0% +will get into you know what some of the +the possible beneficial features of feed + + align:start position:0% +the possible beneficial features of feed + + + align:start position:0% +the possible beneficial features of feed +forward loops on Thursday we talked + + align:start position:0% +forward loops on Thursday we talked + + + align:start position:0% +forward loops on Thursday we talked +about about the + + align:start position:0% +about about the + + + align:start position:0% +about about the +repressilator right so if you have x + + align:start position:0% +repressilator right so if you have x + + + align:start position:0% +repressilator right so if you have x +inhibiting y inhibiting z coming back + + align:start position:0% +inhibiting y inhibiting z coming back + + + align:start position:0% +inhibiting y inhibiting z coming back +and inhibiting X that this thing can is + + align:start position:0% +and inhibiting X that this thing can is + + + align:start position:0% +and inhibiting X that this thing can is +you know it's reasonable to expect that + + align:start position:0% +you know it's reasonable to expect that + + + align:start position:0% +you know it's reasonable to expect that +it might generate oscillations right and + + align:start position:0% +it might generate oscillations right and + + + align:start position:0% +it might generate oscillations right and +indeed in in the elowitz paper that we + + align:start position:0% +indeed in in the elowitz paper that we + + + align:start position:0% +indeed in in the elowitz paper that we +read uh such a such a synthetic circuit + + align:start position:0% +read uh such a such a synthetic circuit + + + align:start position:0% +read uh such a such a synthetic circuit +did indeed uh generate oscillations but + + align:start position:0% +did indeed uh generate oscillations but + + + align:start position:0% +did indeed uh generate oscillations but +uh there were perhaps a few problems + + align:start position:0% +uh there were perhaps a few problems + + + align:start position:0% +uh there were perhaps a few problems +there right so one is that only about + + align:start position:0% +there right so one is that only about + + + align:start position:0% +there right so one is that only about +40% % of the cells actually oscillated + + align:start position:0% +40% % of the cells actually oscillated + + + align:start position:0% +40% % of the cells actually oscillated +uh right uh who knows why not right but + + align:start position:0% +uh right uh who knows why not right but + + + align:start position:0% +uh right uh who knows why not right but +also there were there were other + + align:start position:0% +also there were there were other + + + align:start position:0% +also there were there were other +problems that the the oscillations + + align:start position:0% +problems that the the oscillations + + + align:start position:0% +problems that the the oscillations +seemed rather noisy there was relatively + + align:start position:0% +seemed rather noisy there was relatively + + + align:start position:0% +seemed rather noisy there was relatively +rapid uh U kind of + + align:start position:0% +rapid uh U kind of + + + align:start position:0% +rapid uh U kind of +desynchronization uh + + align:start position:0% +desynchronization uh + + + align:start position:0% +desynchronization uh +moreover if you if you go and you you + + align:start position:0% +moreover if you if you go and you you + + + align:start position:0% +moreover if you if you go and you you +ask well is it possible or how easy + + align:start position:0% +ask well is it possible or how easy + + + align:start position:0% +ask well is it possible or how easy +would it be to change the period of the + + align:start position:0% +would it be to change the period of the + + + align:start position:0% +would it be to change the period of the +oscillations just by changing something + + align:start position:0% +oscillations just by changing something + + + align:start position:0% +oscillations just by changing something +like the degradation rate what you'll + + align:start position:0% +like the degradation rate what you'll + + + align:start position:0% +like the degradation rate what you'll +find is that the oscillation + + align:start position:0% +find is that the oscillation + + + align:start position:0% +find is that the oscillation +are not very tunable okay so so I'll say + + align:start position:0% +are not very tunable okay so so I'll say + + + align:start position:0% +are not very tunable okay so so I'll say +the period or the frequency is not very + + align:start position:0% +the period or the frequency is not very + + + align:start position:0% +the period or the frequency is not very +tunable + + align:start position:0% +tunable + + + align:start position:0% +tunable +okay and indeed this is a general + + align:start position:0% +okay and indeed this is a general + + + align:start position:0% +okay and indeed this is a general +feature of os oscillatory networks that + + align:start position:0% +feature of os oscillatory networks that + + + align:start position:0% +feature of os oscillatory networks that +that have purely negative uh + + align:start position:0% +that have purely negative uh + + + align:start position:0% +that have purely negative uh +interactions right so we talked about a + + align:start position:0% +interactions right so we talked about a + + + align:start position:0% +interactions right so we talked about a +couple of these cases so for example you + + align:start position:0% +couple of these cases so for example you + + + align:start position:0% +couple of these cases so for example you +can get oscillations just with negative + + align:start position:0% +can get oscillations just with negative + + + align:start position:0% +can get oscillations just with negative +Auto regulation and what what is it + + align:start position:0% +Auto regulation and what what is it + + + align:start position:0% +Auto regulation and what what is it +that's necessary + + align:start position:0% + + + + align:start position:0% + +what's + + align:start position:0% +what's + + + align:start position:0% +what's +that high coordination you mean oh + + align:start position:0% +that high coordination you mean oh + + + align:start position:0% +that high coordination you mean oh +you're you're you're cooperativity in + + align:start position:0% +you're you're you're cooperativity in + + + align:start position:0% +you're you're you're cooperativity in +the repression all right so so that I + + align:start position:0% +the repression all right so so that I + + + align:start position:0% +the repression all right so so that I +think is necessary but is it is it going + + align:start position:0% +think is necessary but is it is it going + + + align:start position:0% +think is necessary but is it is it going +to be is it + + align:start position:0% +to be is it + + + align:start position:0% +to be is it +sufficient right I mean even in this + + align:start position:0% +sufficient right I mean even in this + + + align:start position:0% +sufficient right I mean even in this +case where I just have let's say that I + + align:start position:0% +case where I just have let's say that I + + + align:start position:0% +case where I just have let's say that I +I say okay x dot the rate of production + + align:start position:0% +I say okay x dot the rate of production + + + align:start position:0% +I say okay x dot the rate of production +if this thing is just as a function of X + + align:start position:0% +if this thing is just as a function of X + + + align:start position:0% +if this thing is just as a function of X +the sharpest it could be right this is + + align:start position:0% +the sharpest it could be right this is + + + align:start position:0% +the sharpest it could be right this is +kind of infinite cooperativity so it's + + align:start position:0% +kind of infinite cooperativity so it's + + + align:start position:0% +kind of infinite cooperativity so it's +maximal ression then when you get above + + align:start position:0% +maximal ression then when you get above + + + align:start position:0% +maximal ression then when you get above +some X critical all of a sudden you + + align:start position:0% +some X critical all of a sudden you + + + align:start position:0% +some X critical all of a sudden you +fully repress okay if I just have this + + align:start position:0% +fully repress okay if I just have this + + + align:start position:0% +fully repress okay if I just have this +be the formula do you guys understand + + align:start position:0% +be the formula do you guys understand + + + align:start position:0% +be the formula do you guys understand +what I'm referring to here right would + + align:start position:0% +what I'm referring to here right would + + + align:start position:0% +what I'm referring to here right would +would this generate would this generate + + align:start position:0% +would this generate would this generate + + + align:start position:0% +would this generate would this generate +oscillations so it actually doesn't + + align:start position:0% +oscillations so it actually doesn't + + + align:start position:0% +oscillations so it actually doesn't +right so if in the simple equation where + + align:start position:0% +right so if in the simple equation where + + + align:start position:0% +right so if in the simple equation where +we if we have x dot is equal to this + + align:start position:0% +we if we have x dot is equal to this + + + align:start position:0% +we if we have x dot is equal to this +function so I guess this is a + + align:start position:0% +function so I guess this is a + + + align:start position:0% +function so I guess this is a +Theta I want to make sure I get this x + + align:start position:0% +Theta I want to make sure I get this x + + + align:start position:0% +Theta I want to make sure I get this x +less than x critical that's what that's + + align:start position:0% +less than x critical that's what that's + + + align:start position:0% +less than x critical that's what that's +what this means right so with some B + + align:start position:0% +what this means right so with some B + + + align:start position:0% +what this means right so with some B +rate beta minus some alpha + + align:start position:0% +rate beta minus some alpha + + + align:start position:0% +rate beta minus some alpha +x did does this thing + + align:start position:0% +x did does this thing + + + align:start position:0% +x did does this thing +oscillate no and and we had a simple + + align:start position:0% +oscillate no and and we had a simple + + + align:start position:0% +oscillate no and and we had a simple +argument for why it did not oscillate as + + align:start position:0% + + + + align:start position:0% + +well yes right can yell it out somebody + + align:start position:0% +well yes right can yell it out somebody + + + align:start position:0% +well yes right can yell it out somebody +somebody that was you know I'm sure + + align:start position:0% +somebody that was you know I'm sure + + + align:start position:0% +somebody that was you know I'm sure +somebody was here on Thursday + + align:start position:0% + + + + align:start position:0% + +um that's right the T yeah so this is + + align:start position:0% +um that's right the T yeah so this is + + + align:start position:0% +um that's right the T yeah so this is +just this is a single this is just an x + + align:start position:0% +just this is a single this is just an x + + + align:start position:0% +just this is a single this is just an x +dot there's no X double dot right so + + align:start position:0% +dot there's no X double dot right so + + + align:start position:0% +dot there's no X double dot right so +that means the derivative of x is single + + align:start position:0% +that means the derivative of x is single + + + align:start position:0% +that means the derivative of x is single +value is a function of X that means that + + align:start position:0% +value is a function of X that means that + + + align:start position:0% +value is a function of X that means that +we can't get any that looks any any + + align:start position:0% +we can't get any that looks any any + + + align:start position:0% +we can't get any that looks any any +oscillation + + align:start position:0% +oscillation + + + align:start position:0% +oscillation +here right then we remember we analyze + + align:start position:0% +here right then we remember we analyze + + + align:start position:0% +here right then we remember we analyze +this model where we explicitly included + + align:start position:0% +this model where we explicitly included + + + align:start position:0% +this model where we explicitly included +the + + align:start position:0% +the + + + align:start position:0% +the +MRNA right so then we just had that X + + align:start position:0% +MRNA right so then we just had that X + + + align:start position:0% +MRNA right so then we just had that X +comes and what it does is it represses + + align:start position:0% +comes and what it does is it represses + + + align:start position:0% +comes and what it does is it represses +produ expression of this mRNA for x and + + align:start position:0% +produ expression of this mRNA for x and + + + align:start position:0% +produ expression of this mRNA for x and +then this mRNA comes back and makes + + align:start position:0% +then this mRNA comes back and makes + + + align:start position:0% +then this mRNA comes back and makes +X + + align:start position:0% +X + + + align:start position:0% +X +right and uh in this model was this + + align:start position:0% +right and uh in this model was this + + + align:start position:0% +right and uh in this model was this +sufficient did this give + + align:start position:0% +sufficient did this give + + + align:start position:0% +sufficient did this give +oscillations no all right so this Al so + + align:start position:0% +oscillations no all right so this Al so + + + align:start position:0% +oscillations no all right so this Al so +here there was no + + align:start position:0% +here there was no + + + align:start position:0% +here there was no +oscillations again here there were no + + align:start position:0% +oscillations again here there were no + + + align:start position:0% +oscillations again here there were no +oscillations but I did tell you that + + align:start position:0% +oscillations but I did tell you that + + + align:start position:0% +oscillations but I did tell you that +there was something that that you could + + align:start position:0% +there was something that that you could + + + align:start position:0% +there was something that that you could +do something more to get oscillations + + align:start position:0% +do something more to get oscillations + + + align:start position:0% +do something more to get oscillations +just with a single protein repressing + + align:start position:0% +just with a single protein repressing + + + align:start position:0% +just with a single protein repressing +itself right so yeah so you need more + + align:start position:0% +itself right so yeah so you need more + + + align:start position:0% +itself right so yeah so you need more +delays all right so if you add + + align:start position:0% +delays all right so if you add + + + align:start position:0% +delays all right so if you add +delays then it's possible + + align:start position:0% +delays then it's possible + + + align:start position:0% +delays then it's possible +to get um to get oscillations + + align:start position:0% +to get um to get oscillations + + + align:start position:0% +to get um to get oscillations +okay all right so those delays uh could + + align:start position:0% +okay all right so those delays uh could + + + align:start position:0% +okay all right so those delays uh could +be in the form of having a model where + + align:start position:0% +be in the form of having a model where + + + align:start position:0% +be in the form of having a model where +you explicitly take into account that + + align:start position:0% +you explicitly take into account that + + + align:start position:0% +you explicitly take into account that +that first the MRNA is made and then + + align:start position:0% +that first the MRNA is made and then + + + align:start position:0% +that first the MRNA is made and then +that goes and then you translate that to + + align:start position:0% +that goes and then you translate that to + + + align:start position:0% +that goes and then you translate that to +make some monomer and then the monomer + + align:start position:0% +make some monomer and then the monomer + + + align:start position:0% +make some monomer and then the monomer +has to maybe fold and then the folded + + align:start position:0% +has to maybe fold and then the folded + + + align:start position:0% +has to maybe fold and then the folded +protein maybe has to dimerize in order + + align:start position:0% +protein maybe has to dimerize in order + + + align:start position:0% +protein maybe has to dimerize in order +to do repression right so if you have a + + align:start position:0% +to do repression right so if you have a + + + align:start position:0% +to do repression right so if you have a +more detailed mechanistic model that + + align:start position:0% +more detailed mechanistic model that + + + align:start position:0% +more detailed mechanistic model that +includes all these steps that kind of + + align:start position:0% +includes all these steps that kind of + + + align:start position:0% +includes all these steps that kind of +introduces some sort of delay that can + + align:start position:0% +introduces some sort of delay that can + + + align:start position:0% +introduces some sort of delay that can +that in principle can lead to + + align:start position:0% +that in principle can lead to + + + align:start position:0% +that in principle can lead to +oscillations in such a circuit or if you + + align:start position:0% +oscillations in such a circuit or if you + + + align:start position:0% +oscillations in such a circuit or if you +want to you could just explicitly put in + + align:start position:0% +want to you could just explicitly put in + + + align:start position:0% +want to you could just explicitly put in +a delay right so you could say that x + + align:start position:0% +a delay right so you could say that x + + + align:start position:0% +a delay right so you could say that x +dot instead of being a function of + + align:start position:0% +dot instead of being a function of + + + align:start position:0% +dot instead of being a function of +X right instead what you can do is you + + align:start position:0% +X right instead what you can do is you + + + align:start position:0% +X right instead what you can do is you +can say all right well it's actually a + + align:start position:0% +can say all right well it's actually a + + + align:start position:0% +can say all right well it's actually a +function of X at some time uh T minus + + align:start position:0% +function of X at some time uh T minus + + + align:start position:0% +function of X at some time uh T minus +to all right so instead of having the + + align:start position:0% +to all right so instead of having the + + + align:start position:0% +to all right so instead of having the +rate of production of X be a function of + + align:start position:0% +rate of production of X be a function of + + + align:start position:0% +rate of production of X be a function of +X at that moment of time instead it + + align:start position:0% +X at that moment of time instead it + + + align:start position:0% +X at that moment of time instead it +could be a function of X at some + + align:start position:0% +could be a function of X at some + + + align:start position:0% +could be a function of X at some +previous time doing that that's a very + + align:start position:0% +previous time doing that that's a very + + + align:start position:0% +previous time doing that that's a very +explicit form of delay and that can Al + + align:start position:0% +explicit form of delay and that can Al + + + align:start position:0% +explicit form of delay and that can Al +be used to generate oscillations in a + + align:start position:0% +be used to generate oscillations in a + + + align:start position:0% +be used to generate oscillations in a +simple negative a auto regulatory + + align:start position:0% +simple negative a auto regulatory + + + align:start position:0% +simple negative a auto regulatory +Loop + + align:start position:0% +Loop + + + align:start position:0% +Loop +okay all right so these are all + + align:start position:0% +okay all right so these are all + + + align:start position:0% +okay all right so these are all +different kind of approaches for uh for + + align:start position:0% +different kind of approaches for uh for + + + align:start position:0% +different kind of approaches for uh for +encoding oscill or encoding delays into + + align:start position:0% +encoding oscill or encoding delays into + + + align:start position:0% +encoding oscill or encoding delays into +uh into uh the into a model and and and + + align:start position:0% +uh into uh the into a model and and and + + + align:start position:0% +uh into uh the into a model and and and +various approaches will give you + + align:start position:0% +various approaches will give you + + + align:start position:0% +various approaches will give you +oscillations okay + + align:start position:0% +oscillations okay + + + align:start position:0% +oscillations okay +yesod is + + align:start position:0% +yesod is + + + align:start position:0% +yesod is +notable because the LIF is very all + + align:start position:0% +notable because the LIF is very all + + + align:start position:0% +notable because the LIF is very all +right so when when we say yeah model in + + align:start position:0% +right so when when we say yeah model in + + + align:start position:0% +right so when when we say yeah model in +the model can yes that's right so in the + + align:start position:0% +the model can yes that's right so in the + + + align:start position:0% +the model can yes that's right so in the +model you can in principle T it so what + + align:start position:0% +model you can in principle T it so what + + + align:start position:0% +model you can in principle T it so what +what I mean when I say this is that um + + align:start position:0% +what I mean when I say this is that um + + + align:start position:0% +what I mean when I say this is that um +in this class of models so you can also + + align:start position:0% +in this class of models so you can also + + + align:start position:0% +in this class of models so you can also +have instead of this repated with three + + align:start position:0% +have instead of this repated with three + + + align:start position:0% +have instead of this repated with three +you can have the so-called pentil where + + align:start position:0% +you can have the so-called pentil where + + + align:start position:0% +you can have the so-called pentil where +you have five proteins and each is + + align:start position:0% +you have five proteins and each is + + + align:start position:0% +you have five proteins and each is +repressing itself right so there these + + align:start position:0% +repressing itself right so there these + + + align:start position:0% +repressing itself right so there these +are all have you know have similar + + align:start position:0% +are all have you know have similar + + + align:start position:0% +are all have you know have similar +features they all have like these odd + + align:start position:0% +features they all have like these odd + + + align:start position:0% +features they all have like these odd +numbers of proteins going around and + + align:start position:0% +numbers of proteins going around and + + + align:start position:0% +numbers of proteins going around and +repressing one another right so you can + + align:start position:0% +repressing one another right so you can + + + align:start position:0% +repressing one another right so you can +write down the model of seven if you + + align:start position:0% +write down the model of seven if you + + + align:start position:0% +write down the model of seven if you +want right + + align:start position:0% +want right + + + align:start position:0% +want right +but in all these in all these cases um + + align:start position:0% +but in all these in all these cases um + + + align:start position:0% +but in all these in all these cases um +there it's it's not tunable what we mean + + align:start position:0% +there it's it's not tunable what we mean + + + align:start position:0% +there it's it's not tunable what we mean +and what we mean by that is that if you + + align:start position:0% +and what we mean by that is that if you + + + align:start position:0% +and what we mean by that is that if you +when you tune the when you when you tune + + align:start position:0% +when you tune the when you when you tune + + + align:start position:0% +when you tune the when you when you tune +the frequency you in general uh lose uh + + align:start position:0% +the frequency you in general uh lose uh + + + align:start position:0% +the frequency you in general uh lose uh +the amplitude of the oscillation so the + + align:start position:0% +the amplitude of the oscillation so the + + + align:start position:0% +the amplitude of the oscillation so the +amplitude will go down right there's I + + align:start position:0% +amplitude will go down right there's I + + + align:start position:0% +amplitude will go down right there's I +think a very nice uh paper that was + + align:start position:0% +think a very nice uh paper that was + + + align:start position:0% +think a very nice uh paper that was +written in 2008 on this topic uh written + + align:start position:0% +written in 2008 on this topic uh written + + + align:start position:0% +written in 2008 on this topic uh written +by Jim Ferell at Stanford all right so I + + align:start position:0% +by Jim Ferell at Stanford all right so I + + + align:start position:0% +by Jim Ferell at Stanford all right so I +just want to mention this okay so it's + + align:start position:0% +just want to mention this okay so it's + + + align:start position:0% +just want to mention this okay so it's +um feral uh at Stanford + + align:start position:0% +um feral uh at Stanford + + + align:start position:0% +um feral uh at Stanford +uh this is an a paper in science + + align:start position:0% + + + + align:start position:0% + +2008 and um you know and it's called Uh + + align:start position:0% +2008 and um you know and it's called Uh + + + align:start position:0% +2008 and um you know and it's called Uh +robust tunable biological oscillations + + align:start position:0% +robust tunable biological oscillations + + + align:start position:0% +robust tunable biological oscillations +from inter interl positive and negative + + align:start position:0% +from inter interl positive and negative + + + align:start position:0% +from inter interl positive and negative +feedback loops right it's a nice title + + align:start position:0% +feedback loops right it's a nice title + + + align:start position:0% +feedback loops right it's a nice title +right I like titles that say something + + align:start position:0% +right I like titles that say something + + + align:start position:0% +right I like titles that say something +right so it's it's sort of a ultimate + + align:start position:0% +right so it's it's sort of a ultimate + + + align:start position:0% +right so it's it's sort of a ultimate +short version of an abstract right if + + align:start position:0% +short version of an abstract right if + + + align:start position:0% +short version of an abstract right if +you can if you can do it I recommend it + + align:start position:0% +you can if you can do it I recommend it + + + align:start position:0% +you can if you can do it I recommend it +incidentally in graduate school I once + + align:start position:0% +incidentally in graduate school I once + + + align:start position:0% +incidentally in graduate school I once +wrote a paper with four words short + + align:start position:0% +wrote a paper with four words short + + + align:start position:0% +wrote a paper with four words short +words DNA overwinds when stretched right + + align:start position:0% +words DNA overwinds when stretched right + + + align:start position:0% +words DNA overwinds when stretched right +nice statement okay you may or may not + + align:start position:0% +nice statement okay you may or may not + + + align:start position:0% +nice statement okay you may or may not +actually know what I mean by that but + + align:start position:0% +actually know what I mean by that but + + + align:start position:0% +actually know what I mean by that but +you know it's a nice short title it's a + + align:start position:0% +you know it's a nice short title it's a + + + align:start position:0% +you know it's a nice short title it's a +statement right so um I encourage you to + + align:start position:0% +statement right so um I encourage you to + + + align:start position:0% +statement right so um I encourage you to +to think about that when you're writing + + align:start position:0% +to think about that when you're writing + + + align:start position:0% +to think about that when you're writing +your papers + + align:start position:0% +your papers + + + align:start position:0% +your papers +okay all right so so Jim farell he he + + align:start position:0% +okay all right so so Jim farell he he + + + align:start position:0% +okay all right so so Jim farell he he +wrote he wrote this paper where he said + + align:start position:0% +wrote he wrote this paper where he said + + + align:start position:0% +wrote he wrote this paper where he said +all right well you know oscillations are + + align:start position:0% +all right well you know oscillations are + + + align:start position:0% +all right well you know oscillations are +really important right thinking about + + align:start position:0% +really important right thinking about + + + align:start position:0% +really important right thinking about +context of heart rhythms or cell cycle + + align:start position:0% +context of heart rhythms or cell cycle + + + align:start position:0% +context of heart rhythms or cell cycle +or this or that right so oscillations + + align:start position:0% +or this or that right so oscillations + + + align:start position:0% +or this or that right so oscillations +are important but if you go and you look + + align:start position:0% +are important but if you go and you look + + + align:start position:0% +are important but if you go and you look +at uh the the circuits that are + + align:start position:0% +at uh the the circuits that are + + + align:start position:0% +at uh the the circuits that are +generating oscillations in biology they + + align:start position:0% +generating oscillations in biology they + + + align:start position:0% +generating oscillations in biology they +often have so-called interl positive and + + align:start position:0% +often have so-called interl positive and + + + align:start position:0% +often have so-called interl positive and +negative feedback loops right so there + + align:start position:0% +negative feedback loops right so there + + + align:start position:0% +negative feedback loops right so there +are many cases where um you have some X + + align:start position:0% +are many cases where um you have some X + + + align:start position:0% +are many cases where um you have some X +that actually has is is positively it's + + align:start position:0% +that actually has is is positively it's + + + align:start position:0% +that actually has is is positively it's +kind of activating itself right and this + + align:start position:0% +kind of activating itself right and this + + + align:start position:0% +kind of activating itself right and this +is very much something that will not + + align:start position:0% +is very much something that will not + + + align:start position:0% +is very much something that will not +lead to oscillations on its own right it + + align:start position:0% +lead to oscillations on its own right it + + + align:start position:0% +lead to oscillations on its own right it +might be bable which is interesting but + + align:start position:0% +might be bable which is interesting but + + + align:start position:0% +might be bable which is interesting but +it not oscillations on its own but then + + align:start position:0% +it not oscillations on its own but then + + + align:start position:0% +it not oscillations on its own but then +there's there's also maybe a negative + + align:start position:0% +there's there's also maybe a negative + + + align:start position:0% +there's there's also maybe a negative +feedback loop through another another + + align:start position:0% +feedback loop through another another + + + align:start position:0% +feedback loop through another another +protein and the idea is that this one + + align:start position:0% +protein and the idea is that this one + + + align:start position:0% +protein and the idea is that this one +somehow operates uh this one's fast and + + align:start position:0% +somehow operates uh this one's fast and + + + align:start position:0% +somehow operates uh this one's fast and +this one's + + align:start position:0% +this one's + + + align:start position:0% +this one's +slow right the key feature of these + + align:start position:0% +slow right the key feature of these + + + align:start position:0% +slow right the key feature of these +relaxation oscillators is there are two + + align:start position:0% +relaxation oscillators is there are two + + + align:start position:0% +relaxation oscillators is there are two +time scales + + align:start position:0% + + + + align:start position:0% + +okay and it's the it's the slow time + + align:start position:0% +okay and it's the it's the slow time + + + align:start position:0% +okay and it's the it's the slow time +scale that specifies the the period of + + align:start position:0% +scale that specifies the the period of + + + align:start position:0% +scale that specifies the the period of +the oscillation and this fast one kind + + align:start position:0% +the oscillation and this fast one kind + + + align:start position:0% +the oscillation and this fast one kind +of locks the system into these + + align:start position:0% +of locks the system into these + + + align:start position:0% +of locks the system into these +alternative States right so you kind of + + align:start position:0% +alternative States right so you kind of + + + align:start position:0% +alternative States right so you kind of +you and this helps maintain the + + align:start position:0% +you and this helps maintain the + + + align:start position:0% +you and this helps maintain the +amplitude because it's it has this + + align:start position:0% +amplitude because it's it has this + + + align:start position:0% +amplitude because it's it has this +nature of being bable right so it's on + + align:start position:0% +nature of being bable right so it's on + + + align:start position:0% +nature of being bable right so it's on +or off okay so this helps you maintain + + align:start position:0% +or off okay so this helps you maintain + + + align:start position:0% +or off okay so this helps you maintain +amplitude all right so this is kind of + + align:start position:0% +amplitude all right so this is kind of + + + align:start position:0% +amplitude all right so this is kind of +in charge of + + align:start position:0% +in charge of + + + align:start position:0% +in charge of +amplitude and this one over here is in + + align:start position:0% +amplitude and this one over here is in + + + align:start position:0% +amplitude and this one over here is in +charge of the + + align:start position:0% +charge of the + + + align:start position:0% +charge of the +period okay so what you can imagine that + + align:start position:0% +period okay so what you can imagine that + + + align:start position:0% +period okay so what you can imagine that +by changing this time scale you can + + align:start position:0% +by changing this time scale you can + + + align:start position:0% +by changing this time scale you can +change the period of the oscillation + + align:start position:0% +change the period of the oscillation + + + align:start position:0% +change the period of the oscillation +whereas this Loop allows you to maintain + + align:start position:0% +whereas this Loop allows you to maintain + + + align:start position:0% +whereas this Loop allows you to maintain +uh maintain the + + align:start position:0% +uh maintain the + + + align:start position:0% +uh maintain the +amplitude Okay and what uh what Jim's + + align:start position:0% +amplitude Okay and what uh what Jim's + + + align:start position:0% +amplitude Okay and what uh what Jim's +group did computationally in this paper + + align:start position:0% +group did computationally in this paper + + + align:start position:0% +group did computationally in this paper +is uh they analyzed uh many different + + align:start position:0% +is uh they analyzed uh many different + + + align:start position:0% +is uh they analyzed uh many different +circuit designs that can lead to + + align:start position:0% +circuit designs that can lead to + + + align:start position:0% +circuit designs that can lead to +oscillations and they showed that for + + align:start position:0% +oscillations and they showed that for + + + align:start position:0% +oscillations and they showed that for +the the loop the loops that are made of + + align:start position:0% +the the loop the loops that are made of + + + align:start position:0% +the the loop the loops that are made of +purely negative interactions like this + + align:start position:0% +purely negative interactions like this + + + align:start position:0% +purely negative interactions like this +if you change if you change a parameter + + align:start position:0% +if you change if you change a parameter + + + align:start position:0% +if you change if you change a parameter +in order to change the period you'll + + align:start position:0% +in order to change the period you'll + + + align:start position:0% +in order to change the period you'll +also in general make the amplitude of + + align:start position:0% +also in general make the amplitude of + + + align:start position:0% +also in general make the amplitude of +the oscillations will drop dramatically + + align:start position:0% +the oscillations will drop dramatically + + + align:start position:0% +the oscillations will drop dramatically +right so that that's so that's the sense + + align:start position:0% +right so that that's so that's the sense + + + align:start position:0% +right so that that's so that's the sense +in which they're not tunable whereas if + + align:start position:0% +in which they're not tunable whereas if + + + align:start position:0% +in which they're not tunable whereas if +you have this kind of design you can + + align:start position:0% +you have this kind of design you can + + + align:start position:0% +you have this kind of design you can +actually uh tune over in some cases a + + align:start position:0% +actually uh tune over in some cases a + + + align:start position:0% +actually uh tune over in some cases a +very wide range but maintain the + + align:start position:0% +very wide range but maintain the + + + align:start position:0% +very wide range but maintain the +amplitude of the oscillation okay and in + + align:start position:0% +amplitude of the oscillation okay and in + + + align:start position:0% +amplitude of the oscillation okay and in +addition to being tunable these things + + align:start position:0% +addition to being tunable these things + + + align:start position:0% +addition to being tunable these things +also end up being robust in various ways + + align:start position:0% +also end up being robust in various ways + + + align:start position:0% +also end up being robust in various ways +right that the oscillation uh is + + align:start position:0% +right that the oscillation uh is + + + align:start position:0% +right that the oscillation uh is +maintained subject to various kinds of + + align:start position:0% +maintained subject to various kinds of + + + align:start position:0% +maintained subject to various kinds of +if you if you twiddle with the + + align:start position:0% +if you if you twiddle with the + + + align:start position:0% +if you if you twiddle with the +parameters you know you double this you + + align:start position:0% +parameters you know you double this you + + + align:start position:0% +parameters you know you double this you +have that you can still get nice + + align:start position:0% +have that you can still get nice + + + align:start position:0% +have that you can still get nice +oscillations here whereas um in in those + + align:start position:0% +oscillations here whereas um in in those + + + align:start position:0% +oscillations here whereas um in in those +designs you tend to you tend to lose the + + align:start position:0% +designs you tend to you tend to lose the + + + align:start position:0% +designs you tend to you tend to lose the +oscillations more easily right so they + + align:start position:0% +oscillations more easily right so they + + + align:start position:0% +oscillations more easily right so they +claim that based on that that these + + align:start position:0% +claim that based on that that these + + + align:start position:0% +claim that based on that that these +might be more evolvable okay so even in + + align:start position:0% +might be more evolvable okay so even in + + + align:start position:0% +might be more evolvable okay so even in +cases where you don't need to tune the + + align:start position:0% +cases where you don't need to tune the + + + align:start position:0% +cases where you don't need to tune the +period maybe you still end up evolving + + align:start position:0% +period maybe you still end up evolving + + + align:start position:0% +period maybe you still end up evolving +towards this design just because it's + + align:start position:0% +towards this design just because it's + + + align:start position:0% +towards this design just because it's +robust to stochastic fluctuations and + + align:start position:0% +robust to stochastic fluctuations and + + + align:start position:0% +robust to stochastic fluctuations and +the concentrations of things but also it + + align:start position:0% +the concentrations of things but also it + + + align:start position:0% +the concentrations of things but also it +might be easier to evolve these sorts of + + align:start position:0% +might be easier to evolve these sorts of + + + align:start position:0% +might be easier to evolve these sorts of +U these sorts of oscillations + + align:start position:0% +U these sorts of oscillations + + + align:start position:0% +U these sorts of oscillations +okay um are there any questions about + + align:start position:0% +okay um are there any questions about + + + align:start position:0% +okay um are there any questions about +the the kind of intuition behind this + + align:start position:0% +the the kind of intuition behind this + + + align:start position:0% +the the kind of intuition behind this +for + + align:start position:0% +for + + + align:start position:0% +for +now there's there's a nice kind of + + align:start position:0% +now there's there's a nice kind of + + + align:start position:0% +now there's there's a nice kind of +circuit analogy that people talk about + + align:start position:0% +circuit analogy that people talk about + + + align:start position:0% +circuit analogy that people talk about +in the context of um of this s right so + + align:start position:0% +in the context of um of this s right so + + + align:start position:0% +in the context of um of this s right so +if you imagine you have some battery + + align:start position:0% +if you imagine you have some battery + + + align:start position:0% +if you imagine you have some battery +with some voltage V well say we'll say V + + align:start position:0% +with some voltage V well say we'll say V + + + align:start position:0% +with some voltage V well say we'll say V +battery all + + align:start position:0% +battery all + + + align:start position:0% +battery all +right some capacitor over + + align:start position:0% + + + + align:start position:0% + +here + + align:start position:0% +here + + + align:start position:0% +here +right but over here you + + align:start position:0% +right but over here you + + + align:start position:0% +right but over here you +have something + + align:start position:0% +have something + + + align:start position:0% +have something +that uh will uh + + align:start position:0% +that uh will uh + + + align:start position:0% +that uh will uh +spark at some voltage some VT you get a + + align:start position:0% +spark at some voltage some VT you get a + + + align:start position:0% +spark at some voltage some VT you get a +you get a + + align:start position:0% +you get a + + + align:start position:0% +you get a +spark all right now the question is well + + align:start position:0% +spark all right now the question is well + + + align:start position:0% +spark all right now the question is well +um what happens over time if V threshold + + align:start position:0% +um what happens over time if V threshold + + + align:start position:0% +um what happens over time if V threshold +is less than V battery okay so oh no we + + align:start position:0% +is less than V battery okay so oh no we + + + align:start position:0% +is less than V battery okay so oh no we +maybe should have a resistor in here + + align:start position:0% + + + + align:start position:0% + +for so V threshold is Le less than V + + align:start position:0% +for so V threshold is Le less than V + + + align:start position:0% +for so V threshold is Le less than V +battery then um this can generate nice + + align:start position:0% +battery then um this can generate nice + + + align:start position:0% +battery then um this can generate nice +um nice oscillations in the voltage say + + align:start position:0% +um nice oscillations in the voltage say + + + align:start position:0% +um nice oscillations in the voltage say +across the capacitor as a function of + + align:start position:0% +across the capacitor as a function of + + + align:start position:0% +across the capacitor as a function of +time that are tunable right because if + + align:start position:0% +time that are tunable right because if + + + align:start position:0% +time that are tunable right because if +you plot as a function of + + align:start position:0% +you plot as a function of + + + align:start position:0% +you plot as a function of +time this is the voltage across the + + align:start position:0% +time this is the voltage across the + + + align:start position:0% +time this is the voltage across the +capacitor where up here we might have + + align:start position:0% +capacitor where up here we might have + + + align:start position:0% +capacitor where up here we might have +the V of the battery here we might have + + align:start position:0% +the V of the battery here we might have + + + align:start position:0% +the V of the battery here we might have +v v threshold okay now in the absence of + + align:start position:0% +v v threshold okay now in the absence of + + + align:start position:0% +v v threshold okay now in the absence of +this thing that's going to short + + align:start position:0% +this thing that's going to short + + + align:start position:0% +this thing that's going to short +periodically we're just going to charge + + align:start position:0% +periodically we're just going to charge + + + align:start position:0% +periodically we're just going to charge +up the capacitor right so in principle + + align:start position:0% +up the capacitor right so in principle + + + align:start position:0% +up the capacitor right so in principle +there's going to be this standard RC + + align:start position:0% +there's going to be this standard RC + + + align:start position:0% +there's going to be this standard RC +time constant coming up to here right + + align:start position:0% +time constant coming up to here right + + + align:start position:0% +time constant coming up to here right +but instead of before we get there we + + align:start position:0% +but instead of before we get there we + + + align:start position:0% +but instead of before we get there we +get the spark right so then we get we + + align:start position:0% +get the spark right so then we get we + + + align:start position:0% +get the spark right so then we get we +discharge across here and then we this + + align:start position:0% +discharge across here and then we this + + + align:start position:0% +discharge across here and then we this +drops + + align:start position:0% + + + + align:start position:0% + +right so you get something that looks + + align:start position:0% +right so you get something that looks + + + align:start position:0% +right so you get something that looks +like + + align:start position:0% +like + + + align:start position:0% +like +this all right now you can imagine by + + align:start position:0% +this all right now you can imagine by + + + align:start position:0% +this all right now you can imagine by +changing for example the + + align:start position:0% +changing for example the + + + align:start position:0% +changing for example the +resistor you can change the the rate + + align:start position:0% +resistor you can change the the rate + + + align:start position:0% +resistor you can change the the rate +that this thing the capacitor will + + align:start position:0% +that this thing the capacitor will + + + align:start position:0% +that this thing the capacitor will +charge up right but the amplitude of the + + align:start position:0% +charge up right but the amplitude of the + + + align:start position:0% +charge up right but the amplitude of the +oscillations stay constant because + + align:start position:0% +oscillations stay constant because + + + align:start position:0% +oscillations stay constant because +that's set by uh the voltage threshold + + align:start position:0% +that's set by uh the voltage threshold + + + align:start position:0% +that's set by uh the voltage threshold +across this um + + align:start position:0% +across this um + + + align:start position:0% +across this um +uh where it where it shorts okay right + + align:start position:0% +uh where it where it shorts okay right + + + align:start position:0% +uh where it where it shorts okay right +so this is and this is capturing this + + align:start position:0% +so this is and this is capturing this + + + align:start position:0% +so this is and this is capturing this +Dynamic of the separation of time scales + + align:start position:0% +Dynamic of the separation of time scales + + + align:start position:0% +Dynamic of the separation of time scales +right so there's a slow time scale which + + align:start position:0% +right so there's a slow time scale which + + + align:start position:0% +right so there's a slow time scale which +is this RC time constant and then + + align:start position:0% +is this RC time constant and then + + + align:start position:0% +is this RC time constant and then +there's the rapid time scale is where + + align:start position:0% +there's the rapid time scale is where + + + align:start position:0% +there's the rapid time scale is where +where this shorts off okay and so you + + align:start position:0% +where this shorts off okay and so you + + + align:start position:0% +where this shorts off okay and so you +can imagine that this is an example of + + align:start position:0% +can imagine that this is an example of + + + align:start position:0% +can imagine that this is an example of +an oscillatory signal that we can we can + + align:start position:0% +an oscillatory signal that we can we can + + + align:start position:0% +an oscillatory signal that we can we can +tune the frequency without sacrificing + + align:start position:0% +tune the frequency without sacrificing + + + align:start position:0% +tune the frequency without sacrificing +the amplitude + + align:start position:0% + + + + align:start position:0% + +right right so + + align:start position:0% +right right so + + + align:start position:0% +right right so +what we what we've said so far is that + + align:start position:0% +what we what we've said so far is that + + + align:start position:0% +what we what we've said so far is that +uh you know there they're engineering + + align:start position:0% +uh you know there they're engineering + + + align:start position:0% +uh you know there they're engineering +analoges to these sorts of relaxation + + align:start position:0% +analoges to these sorts of relaxation + + + align:start position:0% +analoges to these sorts of relaxation +oscillators we can model various + + align:start position:0% +oscillators we can model various + + + align:start position:0% +oscillators we can model various +synthetic circuits or we can look at + + align:start position:0% +synthetic circuits or we can look at + + + align:start position:0% +synthetic circuits or we can look at +natural uh at natural oscillatory + + align:start position:0% +natural uh at natural oscillatory + + + align:start position:0% +natural uh at natural oscillatory +networks in order to get a sense of + + align:start position:0% +networks in order to get a sense of + + + align:start position:0% +networks in order to get a sense of +what's going on right but of course uh a + + align:start position:0% +what's going on right but of course uh a + + + align:start position:0% +what's going on right but of course uh a +major goal of this kind of system + + align:start position:0% +major goal of this kind of system + + + align:start position:0% +major goal of this kind of system +synthetic approach to uh to the field is + + align:start position:0% +synthetic approach to uh to the field is + + + align:start position:0% +synthetic approach to uh to the field is +it you know if if all this stuff is + + align:start position:0% +it you know if if all this stuff is + + + align:start position:0% +it you know if if all this stuff is +really true we should be able to build + + align:start position:0% +really true we should be able to build + + + align:start position:0% +really true we should be able to build +it right and and there's a very nice + + align:start position:0% +it right and and there's a very nice + + + align:start position:0% +it right and and there's a very nice +demonstration of this also in 2008 by + + align:start position:0% +demonstration of this also in 2008 by + + + align:start position:0% +demonstration of this also in 2008 by +Jeff Hasty's + + align:start position:0% +Jeff Hasty's + + + align:start position:0% +Jeff Hasty's +group all right so Jeff + + align:start position:0% +group all right so Jeff + + + align:start position:0% +group all right so Jeff +Hasty uh was uh was actually trained as + + align:start position:0% +Hasty uh was uh was actually trained as + + + align:start position:0% +Hasty uh was uh was actually trained as +a high energy + + align:start position:0% +a high energy + + + align:start position:0% +a high energy +theorist uh and then I think guess it + + align:start position:0% +theorist uh and then I think guess it + + + align:start position:0% +theorist uh and then I think guess it +was during his postto maybe switched + + align:start position:0% +was during his postto maybe switched + + + align:start position:0% +was during his postto maybe switched +into uh experimental biology wenton did + + align:start position:0% +into uh experimental biology wenton did + + + align:start position:0% +into uh experimental biology wenton did +his postto I think with uh with Jim + + align:start position:0% +his postto I think with uh with Jim + + + align:start position:0% +his postto I think with uh with Jim +Collins and then uh and then eventually + + align:start position:0% +Collins and then uh and then eventually + + + align:start position:0% +Collins and then uh and then eventually +now has his own group doing systems + + align:start position:0% +now has his own group doing systems + + + align:start position:0% +now has his own group doing systems +synthetic biology right so in this paper + + align:start position:0% +synthetic biology right so in this paper + + + align:start position:0% +synthetic biology right so in this paper +it was a it was a nature paper in 2008 + + align:start position:0% + + + + align:start position:0% + +um it's called again a fast robust and + + align:start position:0% +um it's called again a fast robust and + + + align:start position:0% +um it's called again a fast robust and +tunable synthetic Gene oscillator right + + align:start position:0% +tunable synthetic Gene oscillator right + + + align:start position:0% +tunable synthetic Gene oscillator right +it's a nice statement tells you what + + align:start position:0% +it's a nice statement tells you what + + + align:start position:0% +it's a nice statement tells you what +he's about to do right but um the data + + align:start position:0% +he's about to do right but um the data + + + align:start position:0% +he's about to do right but um the data +here so this is again um it's it's using + + align:start position:0% +here so this is again um it's it's using + + + align:start position:0% +here so this is again um it's it's using +these B this basic Insight of uh having + + align:start position:0% +these B this basic Insight of uh having + + + align:start position:0% +these B this basic Insight of uh having +both interl positive negative feedback + + align:start position:0% +both interl positive negative feedback + + + align:start position:0% +both interl positive negative feedback +loops in eoli he demonstrated that uh + + align:start position:0% +loops in eoli he demonstrated that uh + + + align:start position:0% +loops in eoli he demonstrated that uh +that he can get really beautiful + + align:start position:0% +that he can get really beautiful + + + align:start position:0% +that he can get really beautiful +oscillations in essentially all the + + align:start position:0% +oscillations in essentially all the + + + align:start position:0% +oscillations in essentially all the +cells and that they're tunable in Period + + align:start position:0% +cells and that they're tunable in Period + + + align:start position:0% +cells and that they're tunable in Period +by a factor of three or four or so right + + align:start position:0% +by a factor of three or four or so right + + + align:start position:0% +by a factor of three or four or so right +so by a by a fair amount and indeed uh + + align:start position:0% +so by a by a fair amount and indeed uh + + + align:start position:0% +so by a by a fair amount and indeed uh +as as fast as 13 minutes the the + + align:start position:0% +as as fast as 13 minutes the the + + + align:start position:0% +as as fast as 13 minutes the the +oscillatory period right which is pretty + + align:start position:0% +oscillatory period right which is pretty + + + align:start position:0% +oscillatory period right which is pretty +nice right um so I encourage you to to + + align:start position:0% +nice right um so I encourage you to to + + + align:start position:0% +nice right um so I encourage you to to +to check out this paper U this paper was + + align:start position:0% +to check out this paper U this paper was + + + align:start position:0% +to check out this paper U this paper was +um was also an example of + + align:start position:0% +um was also an example of + + + align:start position:0% +um was also an example of +uh how it was in principle possible to + + align:start position:0% +uh how it was in principle possible to + + + align:start position:0% +uh how it was in principle possible to +get oscillations just uh by doing + + align:start position:0% +get oscillations just uh by doing + + + align:start position:0% +get oscillations just uh by doing +negative Auto regulation right so this + + align:start position:0% +negative Auto regulation right so this + + + align:start position:0% +negative Auto regulation right so this +was case where they they designed a gene + + align:start position:0% +was case where they they designed a gene + + + align:start position:0% +was case where they they designed a gene +Network that would uh that they could + + align:start position:0% +Network that would uh that they could + + + align:start position:0% +Network that would uh that they could +tune and had this wonderful property but + + align:start position:0% +tune and had this wonderful property but + + + align:start position:0% +tune and had this wonderful property but +then after they did that they noticed + + align:start position:0% +then after they did that they noticed + + + align:start position:0% +then after they did that they noticed +that in their model at least they could + + align:start position:0% +that in their model at least they could + + + align:start position:0% +that in their model at least they could +get oscillations in some parameter + + align:start position:0% +get oscillations in some parameter + + + align:start position:0% +get oscillations in some parameter +regime just by having a negative Auto + + align:start position:0% +regime just by having a negative Auto + + + align:start position:0% +regime just by having a negative Auto +regulatory Loop but and as a result of + + align:start position:0% +regulatory Loop but and as a result of + + + align:start position:0% +regulatory Loop but and as a result of +all these uh intermediate processes of + + align:start position:0% +all these uh intermediate processes of + + + align:start position:0% +all these uh intermediate processes of +protein maturation and so forth and they + + align:start position:0% +protein maturation and so forth and they + + + align:start position:0% +protein maturation and so forth and they +went and they constructed that Network + + align:start position:0% +went and they constructed that Network + + + align:start position:0% +went and they constructed that Network +and they showed that that could also + + align:start position:0% +and they showed that that could also + + + align:start position:0% +and they showed that that could also +oscillate right so again this is an + + align:start position:0% +oscillate right so again this is an + + + align:start position:0% +oscillate right so again this is an +example of the interplay between + + align:start position:0% +example of the interplay between + + + align:start position:0% +example of the interplay between +modeling experiment Theory modeling and + + align:start position:0% +modeling experiment Theory modeling and + + + align:start position:0% +modeling experiment Theory modeling and +and Jeff has gone on to to write another + + align:start position:0% +and Jeff has gone on to to write another + + + align:start position:0% +and Jeff has gone on to to write another +uh several really beautiful papers uh + + align:start position:0% +uh several really beautiful papers uh + + + align:start position:0% +uh several really beautiful papers uh +looking at at these sorts of + + align:start position:0% +looking at at these sorts of + + + align:start position:0% +looking at at these sorts of +oscillations looking at how you can get + + align:start position:0% +oscillations looking at how you can get + + + align:start position:0% +oscillations looking at how you can get +um synchronization of oscillators and + + align:start position:0% +um synchronization of oscillators and + + + align:start position:0% +um synchronization of oscillators and +you get period doubling ideas you know + + align:start position:0% +you get period doubling ideas you know + + + align:start position:0% +you get period doubling ideas you know +it's really a whole string of wonderful + + align:start position:0% +it's really a whole string of wonderful + + + align:start position:0% +it's really a whole string of wonderful +uh wonderful papers so I I encourage you + + align:start position:0% +uh wonderful papers so I I encourage you + + + align:start position:0% +uh wonderful papers so I I encourage you +to if you're interested in oscillations + + align:start position:0% +to if you're interested in oscillations + + + align:start position:0% +to if you're interested in oscillations +to look at look at Jeff Hasty's work + + align:start position:0% +to look at look at Jeff Hasty's work + + + align:start position:0% +to look at look at Jeff Hasty's work +over the years um and uh right so so um + + align:start position:0% +over the years um and uh right so so um + + + align:start position:0% +over the years um and uh right so so um +and you know and if you if you want to a + + align:start position:0% +and you know and if you if you want to a + + + align:start position:0% +and you know and if you if you want to a +quick introduction to these papers I I + + align:start position:0% +quick introduction to these papers I I + + + align:start position:0% +quick introduction to these papers I I +also wrote a News and Views and nature + + align:start position:0% +also wrote a News and Views and nature + + + align:start position:0% +also wrote a News and Views and nature +on these two papers so you can you can + + align:start position:0% +on these two papers so you can you can + + + align:start position:0% +on these two papers so you can you can +read that it's only um a page uh so um + + align:start position:0% +read that it's only um a page uh so um + + + align:start position:0% +read that it's only um a page uh so um +so that's although I guess you won't + + align:start position:0% +so that's although I guess you won't + + + align:start position:0% +so that's although I guess you won't +hear anything that you haven't already + + align:start position:0% +hear anything that you haven't already + + + align:start position:0% +hear anything that you haven't already +heard probably um but um yeah any any + + align:start position:0% +heard probably um but um yeah any any + + + align:start position:0% +heard probably um but um yeah any any +other any other questions about this + + align:start position:0% +other any other questions about this + + + align:start position:0% +other any other questions about this +idea of uh how how we can use both + + align:start position:0% +idea of uh how how we can use both + + + align:start position:0% +idea of uh how how we can use both +positive and negative feedback in order + + align:start position:0% +positive and negative feedback in order + + + align:start position:0% +positive and negative feedback in order +to get some nice oscillatory + + align:start position:0% + + + + align:start position:0% + +properties okay then let's um let's move + + align:start position:0% + + + + align:start position:0% + +on all right what did you guys think of + + align:start position:0% +on all right what did you guys think of + + + align:start position:0% +on all right what did you guys think of +um of this paper the barasi + + align:start position:0% + + + + align:start position:0% + +paper good bad difficult Easy Does It + + align:start position:0% +paper good bad difficult Easy Does It + + + align:start position:0% +paper good bad difficult Easy Does It +citations why does it have so many + + align:start position:0% +citations why does it have so many + + + align:start position:0% +citations why does it have so many +citations all right that's yeah no and + + align:start position:0% +citations all right that's yeah no and + + + align:start position:0% +citations all right that's yeah no and +you you should look at how many I mean + + align:start position:0% +you you should look at how many I mean + + + align:start position:0% +you you should look at how many I mean +according to Google Scholar I haven't + + align:start position:0% +according to Google Scholar I haven't + + + align:start position:0% +according to Google Scholar I haven't +checked this year but it's probably like + + align:start position:0% +checked this year but it's probably like + + + align:start position:0% +checked this year but it's probably like +20,000 citations I mean it's a c thing + + align:start position:0% +20,000 citations I mean it's a c thing + + + align:start position:0% +20,000 citations I mean it's a c thing +or um it's a cult thing um well I I I I + + align:start position:0% +or um it's a cult thing um well I I I I + + + align:start position:0% +or um it's a cult thing um well I I I I +don't know that might exaggerating um + + align:start position:0% +don't know that might exaggerating um + + + align:start position:0% +don't know that might exaggerating um +it's a nice yeah right um no right so + + align:start position:0% +it's a nice yeah right um no right so + + + align:start position:0% +it's a nice yeah right um no right so +this is interesting I think that the + + align:start position:0% +this is interesting I think that the + + + align:start position:0% +this is interesting I think that the +basic answer is that um there are + + align:start position:0% +basic answer is that um there are + + + align:start position:0% +basic answer is that um there are +networks that are relevant in many many + + align:start position:0% +networks that are relevant in many many + + + align:start position:0% +networks that are relevant in many many +many fields which they allude to and um + + align:start position:0% +many fields which they allude to and um + + + align:start position:0% +many fields which they allude to and um +and there are many researchers that have + + align:start position:0% +and there are many researchers that have + + + align:start position:0% +and there are many researchers that have +been excited about studying those + + align:start position:0% +been excited about studying those + + + align:start position:0% +been excited about studying those +networks in many many fields and uh many + + align:start position:0% +networks in many many fields and uh many + + + align:start position:0% +networks in many many fields and uh many +many many of the networks that are + + align:start position:0% +many many of the networks that are + + + align:start position:0% +many many of the networks that are +observed in nature social + + align:start position:0% +observed in nature social + + + align:start position:0% +observed in nature social +science the web everywhere they have + + align:start position:0% +science the web everywhere they have + + + align:start position:0% +science the web everywhere they have +these power power LW structures and and + + align:start position:0% +these power power LW structures and and + + + align:start position:0% +these power power LW structures and and +and this is + + align:start position:0% +and this is + + + align:start position:0% +and this is +um the the the you know the first clear + + align:start position:0% +um the the the you know the first clear + + + align:start position:0% +um the the the you know the first clear +simple mechanism to generate it my my + + align:start position:0% +simple mechanism to generate it my my + + + align:start position:0% +simple mechanism to generate it my my +understanding is actually that some you + + align:start position:0% +understanding is actually that some you + + + align:start position:0% +understanding is actually that some you +know that actually a mathematician + + align:start position:0% +know that actually a mathematician + + + align:start position:0% +know that actually a mathematician +decades before actually did demonstrate + + align:start position:0% +decades before actually did demonstrate + + + align:start position:0% +decades before actually did demonstrate +that this kind of thing could be + + align:start position:0% +that this kind of thing could be + + + align:start position:0% +that this kind of thing could be +constructed that would lead to this but + + align:start position:0% +constructed that would lead to this but + + + align:start position:0% +constructed that would lead to this but +um but that paper doesn't have 20,000 + + align:start position:0% +um but that paper doesn't have 20,000 + + + align:start position:0% +um but that paper doesn't have 20,000 +citations you know I mean like it's a + + align:start position:0% +citations you know I mean like it's a + + + align:start position:0% +citations you know I mean like it's a +lot of these things you have to be at + + align:start position:0% +lot of these things you have to be at + + + align:start position:0% +lot of these things you have to be at +the right time the right place and have + + align:start position:0% +the right time the right place and have + + + align:start position:0% +the right time the right place and have +the right idea and you know um yeah I + + align:start position:0% +the right idea and you know um yeah I + + + align:start position:0% +the right idea and you know um yeah I +guess my my main thought about paper is + + align:start position:0% +guess my my main thought about paper is + + + align:start position:0% +guess my my main thought about paper is +exactly that + + align:start position:0% +exactly that + + + align:start position:0% +exactly that +the interesting thing about it was it + + align:start position:0% +the interesting thing about it was it + + + align:start position:0% +the interesting thing about it was it +was it came out at about the time that + + align:start position:0% +was it came out at about the time that + + + align:start position:0% +was it came out at about the time that +data on laun networks was available + + align:start position:0% +data on laun networks was available + + + align:start position:0% +data on laun networks was available +that's right yeah there's a re there's a + + align:start position:0% +that's right yeah there's a re there's a + + + align:start position:0% +that's right yeah there's a re there's a +reason that this paper was U published + + align:start position:0% +reason that this paper was U published + + + align:start position:0% +reason that this paper was U published +at this time and you know and of course + + align:start position:0% +at this time and you know and of course + + + align:start position:0% +at this time and you know and of course +you know if barosi didn't do it here + + align:start position:0% +you know if barosi didn't do it here + + + align:start position:0% +you know if barosi didn't do it here +someone else would have done it a year + + align:start position:0% +someone else would have done it a year + + + align:start position:0% +someone else would have done it a year +or two later right but it was it was + + align:start position:0% +or two later right but it was it was + + + align:start position:0% +or two later right but it was it was +really that that the data were available + + align:start position:0% +really that that the data were available + + + align:start position:0% +really that that the data were available +everywhere and so then that and we were + + align:start position:0% +everywhere and so then that and we were + + + align:start position:0% +everywhere and so then that and we were +seeing these power law distributions and + + align:start position:0% +seeing these power law distributions and + + + align:start position:0% +seeing these power law distributions and +it's really crying out for for an + + align:start position:0% +it's really crying out for for an + + + align:start position:0% +it's really crying out for for an +explanation okay I think it it's you + + align:start position:0% +explanation okay I think it it's you + + + align:start position:0% +explanation okay I think it it's you +know sometimes people complain that they + + align:start position:0% +know sometimes people complain that they + + + align:start position:0% +know sometimes people complain that they +say oh yeah you know I could have come + + align:start position:0% +say oh yeah you know I could have come + + + align:start position:0% +say oh yeah you know I could have come +up with this idea you know it's not that + + align:start position:0% +up with this idea you know it's not that + + + align:start position:0% +up with this idea you know it's not that +deep you know and yeah maybe you could + + align:start position:0% +deep you know and yeah maybe you could + + + align:start position:0% +deep you know and yeah maybe you could +have but you know but you didn't you + + align:start position:0% +have but you know but you didn't you + + + align:start position:0% +have but you know but you didn't you +know uh you know and and also I'd say + + align:start position:0% +know uh you know and and also I'd say + + + align:start position:0% +know uh you know and and also I'd say +that you know you know barabasi has a + + align:start position:0% +that you know you know barabasi has a + + + align:start position:0% +that you know you know barabasi has a +has a record of doing interesting + + align:start position:0% +has a record of doing interesting + + + align:start position:0% +has a record of doing interesting +things and being the first to point out + + align:start position:0% +things and being the first to point out + + + align:start position:0% +things and being the first to point out +a simple idea you know and and you know + + align:start position:0% +a simple idea you know and and you know + + + align:start position:0% +a simple idea you know and and you know +and if if you can reliably be the first + + align:start position:0% +and if if you can reliably be the first + + + align:start position:0% +and if if you can reliably be the first +to point out a simple explanation for + + align:start position:0% +to point out a simple explanation for + + + align:start position:0% +to point out a simple explanation for +important things and that's um that's + + align:start position:0% +important things and that's um that's + + + align:start position:0% +important things and that's um that's +another kind of Genius right I mean you + + align:start position:0% +another kind of Genius right I mean you + + + align:start position:0% +another kind of Genius right I mean you +know and it's um and it's the kind of + + align:start position:0% +know and it's um and it's the kind of + + + align:start position:0% +know and it's um and it's the kind of +Genius that I I would you know I aspire + + align:start position:0% +Genius that I I would you know I aspire + + + align:start position:0% +Genius that I I would you know I aspire +to because I know that I'm not going to + + align:start position:0% +to because I know that I'm not going to + + + align:start position:0% +to because I know that I'm not going to +do the I'm not going to um reach the + + align:start position:0% +do the I'm not going to um reach the + + + align:start position:0% +do the I'm not going to um reach the +other kind of Genius right you know so + + align:start position:0% +other kind of Genius right you know so + + + align:start position:0% +other kind of Genius right you know so +you know I mean you know I mean there + + align:start position:0% +you know I mean you know I mean there + + + align:start position:0% +you know I mean you know I mean there +there I mean there are some things that + + align:start position:0% +there I mean there are some things that + + + align:start position:0% +there I mean there are some things that +you know you look at you're like oh well + + align:start position:0% +you know you look at you're like oh well + + + align:start position:0% +you know you look at you're like oh well +you know I would never be able to do + + align:start position:0% +you know I would never be able to do + + + align:start position:0% +you know I would never be able to do +that right um and uh and those you know + + align:start position:0% +that right um and uh and those you know + + + align:start position:0% +that right um and uh and those you know +everyone agrees that's hard but um but I + + align:start position:0% +everyone agrees that's hard but um but I + + + align:start position:0% +everyone agrees that's hard but um but I +think that there there is something + + align:start position:0% +think that there there is something + + + align:start position:0% +think that there there is something +about being able to see what the + + align:start position:0% +about being able to see what the + + + align:start position:0% +about being able to see what the +scientific opportunities are at a given + + align:start position:0% +scientific opportunities are at a given + + + align:start position:0% +scientific opportunities are at a given +time and you don't have to come up with + + align:start position:0% +time and you don't have to come up with + + + align:start position:0% +time and you don't have to come up with +a really complicated + + align:start position:0% +a really complicated + + + align:start position:0% +a really complicated +model or proof in order to have have + + align:start position:0% +model or proof in order to have have + + + align:start position:0% +model or proof in order to have have +really important impact uh and yeah and + + align:start position:0% +really important impact uh and yeah and + + + align:start position:0% +really important impact uh and yeah and +this paper is um is you know way I mean + + align:start position:0% +this paper is um is you know way I mean + + + align:start position:0% +this paper is um is you know way I mean +Way Beyond and you know in terms of like + + align:start position:0% +Way Beyond and you know in terms of like + + + align:start position:0% +Way Beyond and you know in terms of like +number of people that have read it cited + + align:start position:0% +number of people that have read it cited + + + align:start position:0% +number of people that have read it cited +it and so forth It's you know Way Beyond + + align:start position:0% +it and so forth It's you know Way Beyond + + + align:start position:0% +it and so forth It's you know Way Beyond +probably any other paper you'll likely + + align:start position:0% +probably any other paper you'll likely + + + align:start position:0% +probably any other paper you'll likely +read in your life uh yes uh just more + + align:start position:0% +read in your life uh yes uh just more + + + align:start position:0% +read in your life uh yes uh just more +thoughts more thoughts yeah that's fine + + align:start position:0% +thoughts more thoughts yeah that's fine + + + align:start position:0% +thoughts more thoughts yeah that's fine +yeah yeah I mean I guess what's + + align:start position:0% +yeah yeah I mean I guess what's + + + align:start position:0% +yeah yeah I mean I guess what's +interesting is yeah it starts the + + align:start position:0% +interesting is yeah it starts the + + + align:start position:0% +interesting is yeah it starts the +conversation + + align:start position:0% + + + + align:start position:0% + +yeah no I think that's that's a totally + + align:start position:0% +yeah no I think that's that's a totally + + + align:start position:0% +yeah no I think that's that's a totally +um so this is the barosi and ra Albert + + align:start position:0% +um so this is the barosi and ra Albert + + + align:start position:0% +um so this is the barosi and ra Albert +um so um so barosi is a professor over + + align:start position:0% +um so um so barosi is a professor over + + + align:start position:0% +um so um so barosi is a professor over +at nor Eastern now um ra Albert is a + + align:start position:0% +at nor Eastern now um ra Albert is a + + + align:start position:0% +at nor Eastern now um ra Albert is a +professor at Penn State and I think + + align:start position:0% +professor at Penn State and I think + + + align:start position:0% +professor at Penn State and I think +they've both gone on to do what I I + + align:start position:0% +they've both gone on to do what I I + + + align:start position:0% +they've both gone on to do what I I +think are really very interesting things + + align:start position:0% +think are really very interesting things + + + align:start position:0% +think are really very interesting things +you know in this network space but you + + align:start position:0% +you know in this network space but you + + + align:start position:0% +you know in this network space but you +know and more generally so I you I + + align:start position:0% +know and more generally so I you I + + + align:start position:0% +know and more generally so I you I +encourage you to to check out what what + + align:start position:0% +encourage you to to check out what what + + + align:start position:0% +encourage you to to check out what what +each of them have been doing over the + + align:start position:0% +each of them have been doing over the + + + align:start position:0% +each of them have been doing over the +years uh all right so so all right so + + align:start position:0% +years uh all right so so all right so + + + align:start position:0% +years uh all right so so all right so +this is the this model okay what what + + align:start position:0% +this is the this model okay what what + + + align:start position:0% +this is the this model okay what what +are the two key ingredients of of this + + align:start position:0% + + + + align:start position:0% + +model right so all right so the two + + align:start position:0% +model right so all right so the two + + + align:start position:0% +model right so all right so the two +things that you should be able + + align:start position:0% +things that you should be able + + + align:start position:0% +things that you should be able +to recapitulate on an exam is that there + + align:start position:0% +to recapitulate on an exam is that there + + + align:start position:0% +to recapitulate on an exam is that there +are two assumptions here there's growth + + align:start position:0% +are two assumptions here there's growth + + + align:start position:0% +are two assumptions here there's growth +and there's preferential attachment okay + + align:start position:0% +and there's preferential attachment okay + + + align:start position:0% +and there's preferential attachment okay +and we'll we'll talk about the degree to + + align:start position:0% +and we'll we'll talk about the degree to + + + align:start position:0% +and we'll we'll talk about the degree to +which we think each of those things + + align:start position:0% +which we think each of those things + + + align:start position:0% +which we think each of those things +might be necessary but um what's the + + align:start position:0% +might be necessary but um what's the + + + align:start position:0% +might be necessary but um what's the +what's the + + align:start position:0% +what's the + + + align:start position:0% +what's the +key yeah can somebody be a little more + + align:start position:0% +key yeah can somebody be a little more + + + align:start position:0% +key yeah can somebody be a little more +explicit than what we've been so far + + align:start position:0% +explicit than what we've been so far + + + align:start position:0% +explicit than what we've been so far +about what the key kind of observation + + align:start position:0% +about what the key kind of observation + + + align:start position:0% +about what the key kind of observation +is that we're trying to + + align:start position:0% + + + + align:start position:0% + +explain that + + align:start position:0% + + + + align:start position:0% + +edges random right Perfect Right + + align:start position:0% +edges random right Perfect Right + + + align:start position:0% +edges random right Perfect Right +observation right all right so some + + align:start position:0% +observation right all right so some + + + align:start position:0% +observation right all right so some +nodes have lots of + + align:start position:0% + + + + align:start position:0% + +edges it is kind of + + align:start position:0% + + + + align:start position:0% + +met yes it you it it indeed it is um it + + align:start position:0% +met yes it you it it indeed it is um it + + + align:start position:0% +met yes it you it it indeed it is um it +is ironic and and and we'll we'll we'll + + align:start position:0% +is ironic and and and we'll we'll we'll + + + align:start position:0% +is ironic and and and we'll we'll we'll +talk about how how the scaling of the + + align:start position:0% +talk about how how the scaling of the + + + align:start position:0% +talk about how how the scaling of the +citation networks go in a moment um + + align:start position:0% +citation networks go in a moment um + + + align:start position:0% +citation networks go in a moment um +right so some nodes have lots of edges + + align:start position:0% +right so some nodes have lots of edges + + + align:start position:0% +right so some nodes have lots of edges +all right and um and then you know you + + align:start position:0% +all right and um and then you know you + + + align:start position:0% +all right and um and then you know you +you have you want to be very clear about + + align:start position:0% +you have you want to be very clear about + + + align:start position:0% +you have you want to be very clear about +this this is what the you know you're + + align:start position:0% +this this is what the you know you're + + + align:start position:0% +this this is what the you know you're +trying to explain right so uh it's power + + align:start position:0% +trying to explain right so uh it's power + + + align:start position:0% +trying to explain right so uh it's power +law distribution right so in particular + + align:start position:0% +law distribution right so in particular + + + align:start position:0% +law distribution right so in particular +you can quantify this thing right that + + align:start position:0% +you can quantify this thing right that + + + align:start position:0% +you can quantify this thing right that +the probability of having K nodes or + + align:start position:0% +the probability of having K nodes or + + + align:start position:0% +the probability of having K nodes or +sorry the probability that a node has K + + align:start position:0% +sorry the probability that a node has K + + + align:start position:0% +sorry the probability that a node has K +edges falls off as a power law you know + + align:start position:0% +edges falls off as a power law you know + + + align:start position:0% +edges falls off as a power law you know +1 over K to some power 2 3 4 right so + + align:start position:0% +1 over K to some power 2 3 4 right so + + + align:start position:0% +1 over K to some power 2 3 4 right so +the probability having K edges um goes + + align:start position:0% +the probability having K edges um goes + + + align:start position:0% +the probability having K edges um goes +as 1 over K to some power Alpha right + + align:start position:0% +as 1 over K to some power Alpha right + + + align:start position:0% +as 1 over K to some power Alpha right +where Alpha is kind of you know maybe + + align:start position:0% +where Alpha is kind of you know maybe + + + align:start position:0% +where Alpha is kind of you know maybe +between two and four for a lot of these + + align:start position:0% +between two and four for a lot of these + + + align:start position:0% +between two and four for a lot of these +okay now you know it's important to make + + align:start position:0% +okay now you know it's important to make + + + align:start position:0% +okay now you know it's important to make +sure + + align:start position:0% +sure + + + align:start position:0% +sure +that you you keep this qualitative + + align:start position:0% +that you you keep this qualitative + + + align:start position:0% +that you you keep this qualitative +statement in mind though right because + + align:start position:0% +statement in mind though right because + + + align:start position:0% +statement in mind though right because +you know it's true that it falls off and + + align:start position:0% +you know it's true that it falls off and + + + align:start position:0% +you know it's true that it falls off and +and you know and sort of rapidly right + + align:start position:0% +and you know and sort of rapidly right + + + align:start position:0% +and you know and sort of rapidly right +you know one over K2 K cubed or k to the + + align:start position:0% +you know one over K2 K cubed or k to the + + + align:start position:0% +you know one over K2 K cubed or k to the +4th you'd say oh that's that that's a + + align:start position:0% +4th you'd say oh that's that that's a + + + align:start position:0% +4th you'd say oh that's that that's a +pretty rapid fallof right but it's not + + align:start position:0% +pretty rapid fallof right but it's not + + + align:start position:0% +pretty rapid fallof right but it's not +rapid compared to + + align:start position:0% +rapid compared to + + + align:start position:0% +rapid compared to +what expon right so the for these other + + align:start position:0% +what expon right so the for these other + + + align:start position:0% +what expon right so the for these other +yeah for these other models then it + + align:start position:0% +yeah for these other models then it + + + align:start position:0% +yeah for these other models then it +falls off exponential + + align:start position:0% +falls off exponential + + + align:start position:0% +falls off exponential +right so even faster okay so you know + + align:start position:0% +right so even faster okay so you know + + + align:start position:0% +right so even faster okay so you know +you know it's easy to kind of look at oh + + align:start position:0% +you know it's easy to kind of look at oh + + + align:start position:0% +you know it's easy to kind of look at oh +one k to 4th and think oh that's a fast + + align:start position:0% +one k to 4th and think oh that's a fast + + + align:start position:0% +one k to 4th and think oh that's a fast +fallof right but just we have to + + align:start position:0% +fallof right but just we have to + + + align:start position:0% +fallof right but just we have to +remember that it's uh it's slow compared + + align:start position:0% +remember that it's uh it's slow compared + + + align:start position:0% +remember that it's uh it's slow compared +to some other things right so um in + + align:start position:0% +to some other things right so um in + + + align:start position:0% +to some other things right so um in +particular if you look at the if you + + align:start position:0% +particular if you look at the if you + + + align:start position:0% +particular if you look at the if you +look at the data for real networks right + + align:start position:0% +look at the data for real networks right + + + align:start position:0% +look at the data for real networks right +you see that the probability + + align:start position:0% +you see that the probability + + + align:start position:0% +you see that the probability +distribution in many cases goes over + + align:start position:0% +distribution in many cases goes over + + + align:start position:0% +distribution in many cases goes over +orders of magnitude in terms of this + + align:start position:0% +orders of magnitude in terms of this + + + align:start position:0% +orders of magnitude in terms of this +probability right so you think oh that's + + align:start position:0% +probability right so you think oh that's + + + align:start position:0% +probability right so you think oh that's +a big that's a big range and it is a big + + align:start position:0% +a big that's a big range and it is a big + + + align:start position:0% +a big that's a big range and it is a big +range but uh the fact is that you + + align:start position:0% +range but uh the fact is that you + + + align:start position:0% +range but uh the fact is that you +actually see some no + + align:start position:0% +actually see some no + + + align:start position:0% +actually see some no +with you know the Thousand edges or + + align:start position:0% +with you know the Thousand edges or + + + align:start position:0% +with you know the Thousand edges or +whatnot right which is something you + + align:start position:0% +whatnot right which is something you + + + align:start position:0% +whatnot right which is something you +would just never see if it were a random + + align:start position:0% +would just never see if it were a random + + + align:start position:0% +would just never see if it were a random +Network or if it were you know if it + + align:start position:0% +Network or if it were you know if it + + + align:start position:0% +Network or if it were you know if it +were not a power law distributed Network + + align:start position:0% +were not a power law distributed Network + + + align:start position:0% +were not a power law distributed Network +okay and I think that this is also + + align:start position:0% +okay and I think that this is also + + + align:start position:0% +okay and I think that this is also +highlighting another statement which is + + align:start position:0% +highlighting another statement which is + + + align:start position:0% +highlighting another statement which is +that a powerful way to make a difference + + align:start position:0% +that a powerful way to make a difference + + + align:start position:0% +that a powerful way to make a difference +for example if you're going to write + + align:start position:0% +for example if you're going to write + + + align:start position:0% +for example if you're going to write +down a model or you're going to do + + align:start position:0% +down a model or you're going to do + + + align:start position:0% +down a model or you're going to do +theory is that it's nice if you start if + + align:start position:0% +theory is that it's nice if you start if + + + align:start position:0% +theory is that it's nice if you start if +there's a clear observation that needs + + align:start position:0% +there's a clear observation that needs + + + align:start position:0% +there's a clear observation that needs +to be + + align:start position:0% +to be + + + align:start position:0% +to be +explained okay because you can always + + align:start position:0% +explained okay because you can always + + + align:start position:0% +explained okay because you can always +write down a model of something + + align:start position:0% +write down a model of something + + + align:start position:0% +write down a model of something +and and maybe you'll find something + + align:start position:0% +and and maybe you'll find something + + + align:start position:0% +and and maybe you'll find something +interesting right uh but uh a way to I + + align:start position:0% +interesting right uh but uh a way to I + + + align:start position:0% +interesting right uh but uh a way to I +think massively increase the probability + + align:start position:0% +think massively increase the probability + + + align:start position:0% +think massively increase the probability +that you're going to um discover + + align:start position:0% +that you're going to um discover + + + align:start position:0% +that you're going to um discover +something interesting is if there's all + + align:start position:0% +something interesting is if there's all + + + align:start position:0% +something interesting is if there's all +if you already know there's something + + align:start position:0% +if you already know there's something + + + align:start position:0% +if you already know there's something +interesting there and that you're trying + + align:start position:0% +interesting there and that you're trying + + + align:start position:0% +interesting there and that you're trying +to explain it okay and I think that this + + align:start position:0% +to explain it okay and I think that this + + + align:start position:0% +to explain it okay and I think that this +is an example of that right there was + + align:start position:0% +is an example of that right there was + + + align:start position:0% +is an example of that right there was +already an observation it was already + + align:start position:0% +already an observation it was already + + + align:start position:0% +already an observation it was already +known right it's not that he was the + + align:start position:0% +known right it's not that he was the + + + align:start position:0% +known right it's not that he was the +first person to make those plots right + + align:start position:0% +first person to make those plots right + + + align:start position:0% +first person to make those plots right +there were other plots of citation + + align:start position:0% +there were other plots of citation + + + align:start position:0% +there were other plots of citation +networks before right so Sid rner for + + align:start position:0% +networks before right so Sid rner for + + + align:start position:0% +networks before right so Sid rner for +example had already done some analyses + + align:start position:0% +example had already done some analyses + + + align:start position:0% +example had already done some analyses +of citation networks over uh he's a + + align:start position:0% +of citation networks over uh he's a + + + align:start position:0% +of citation networks over uh he's a +theoretical statistical physicist over + + align:start position:0% +theoretical statistical physicist over + + + align:start position:0% +theoretical statistical physicist over +at bu uh but just now I guess moving uh + + align:start position:0% +at bu uh but just now I guess moving uh + + + align:start position:0% +at bu uh but just now I guess moving uh +over to the um Santa Fe Institute okay + + align:start position:0% +over to the um Santa Fe Institute okay + + + align:start position:0% +over to the um Santa Fe Institute okay +but so it's not that he was the first + + align:start position:0% +but so it's not that he was the first + + + align:start position:0% +but so it's not that he was the first +person to make that observation but he + + align:start position:0% +person to make that observation but he + + + align:start position:0% +person to make that observation but he +knew that there but the obser you know + + align:start position:0% +knew that there but the obser you know + + + align:start position:0% +knew that there but the obser you know +he knew there was something interesting + + align:start position:0% +he knew there was something interesting + + + align:start position:0% +he knew there was something interesting +that needed to be explained right so I'd + + align:start position:0% +that needed to be explained right so I'd + + + align:start position:0% +that needed to be explained right so I'd +say + + align:start position:0% +say + + + align:start position:0% +say +that whatever you know for for any of + + align:start position:0% +that whatever you know for for any of + + + align:start position:0% +that whatever you know for for any of +you that are going thinking about doing + + align:start position:0% +you that are going thinking about doing + + + align:start position:0% +you that are going thinking about doing +Theory or writing down models I I I + + align:start position:0% +Theory or writing down models I I I + + + align:start position:0% +Theory or writing down models I I I +would + + align:start position:0% +would + + + align:start position:0% +would +say whenever possible start start with + + align:start position:0% +say whenever possible start start with + + + align:start position:0% +say whenever possible start start with +an interesting observation + + align:start position:0% +an interesting observation + + + align:start position:0% +an interesting observation +okay all right so can somebody maybe you + + align:start position:0% +okay all right so can somebody maybe you + + + align:start position:0% +okay all right so can somebody maybe you +guys could just throw out what are some + + align:start position:0% +guys could just throw out what are some + + + align:start position:0% +guys could just throw out what are some +examples of nodes and edges that were + + align:start position:0% +examples of nodes and edges that were + + + align:start position:0% +examples of nodes and edges that were +given there or + + align:start position:0% + + + + align:start position:0% + +elsewhere pages and links all right web + + align:start position:0% +elsewhere pages and links all right web + + + align:start position:0% +elsewhere pages and links all right web +pages and links + + align:start position:0% + + + + align:start position:0% + +all right and uh is this a directed or + + align:start position:0% +all right and uh is this a directed or + + + align:start position:0% +all right and uh is this a directed or +an + + align:start position:0% +an + + + align:start position:0% +an +undirected yes so this is indeed + + align:start position:0% +undirected yes so this is indeed + + + align:start position:0% +undirected yes so this is indeed +directed + + align:start position:0% + + + + align:start position:0% + +right right some + + align:start position:0% +right right some + + + align:start position:0% +right right some +others movies movie stars and movies + + align:start position:0% +others movies movie stars and movies + + + align:start position:0% +others movies movie stars and movies +yeah this one's a funny one right okay + + align:start position:0% +yeah this one's a funny one right okay + + + align:start position:0% +yeah this one's a funny one right okay +yeah so movie + + align:start position:0% +yeah so movie + + + align:start position:0% +yeah so movie +stars and then um right and this this is + + align:start position:0% +stars and then um right and this this is + + + align:start position:0% +stars and then um right and this this is +this is um this is like being in a movie + + align:start position:0% +this is um this is like being in a movie + + + align:start position:0% +this is um this is like being in a movie +together right so co-starring or so + + align:start position:0% + + + + align:start position:0% + +all right + + align:start position:0% + + + + align:start position:0% + +others articles and + + align:start position:0% + + + + align:start position:0% + +citations + + align:start position:0% + + + + align:start position:0% + +great + + align:start position:0% +great + + + align:start position:0% +great +articles + + align:start position:0% +articles + + + align:start position:0% +articles +citations all right and this is again + + align:start position:0% +citations all right and this is again + + + align:start position:0% +citations all right and this is again +directed and this is not directed + + align:start position:0% +directed and this is not directed + + + align:start position:0% +directed and this is not directed +right um and and we can maybe even try + + align:start position:0% +right um and and we can maybe even try + + + align:start position:0% +right um and and we can maybe even try +to remind ourselves this this fell off + + align:start position:0% +to remind ourselves this this fell off + + + align:start position:0% +to remind ourselves this this fell off +as alpha alpha was equal to what I guess + + align:start position:0% +as alpha alpha was equal to what I guess + + + align:start position:0% +as alpha alpha was equal to what I guess +it was three I think they + + align:start position:0% +it was three I think they + + + align:start position:0% +it was three I think they +said + + align:start position:0% + + + + align:start position:0% + +um all right + + align:start position:0% + + + + align:start position:0% + +actors were around 2.3 I guess they + + align:start position:0% +actors were around 2.3 I guess they + + + align:start position:0% +actors were around 2.3 I guess they +said all right the web was 2.1 okay all + + align:start position:0% +said all right the web was 2.1 okay all + + + align:start position:0% +said all right the web was 2.1 okay all +right so you know just because it's a + + align:start position:0% +right so you know just because it's a + + + align:start position:0% +right so you know just because it's a +power law doesn't mean that it's always + + align:start position:0% +power law doesn't mean that it's always + + + align:start position:0% +power law doesn't mean that it's always +going to have the same Alpha right um + + align:start position:0% +going to have the same Alpha right um + + + align:start position:0% +going to have the same Alpha right um +but for example what this means is + + align:start position:0% +but for example what this means is + + + align:start position:0% +but for example what this means is +that for every paper that has + + align:start position:0% +that for every paper that has + + + align:start position:0% +that for every paper that has +um + + align:start position:0% +um + + + align:start position:0% +um +say 200 citations there are going to be + + align:start position:0% +say 200 citations there are going to be + + + align:start position:0% +say 200 citations there are going to be +roughly 10 papers that have 100 + + align:start position:0% +roughly 10 papers that have 100 + + + align:start position:0% +roughly 10 papers that have 100 +citations right because if you increase + + align:start position:0% +citations right because if you increase + + + align:start position:0% +citations right because if you increase +K by factor of two you get almost an + + align:start position:0% +K by factor of two you get almost an + + + align:start position:0% +K by factor of two you get almost an +order of magnitude in term in terms of + + align:start position:0% +order of magnitude in term in terms of + + + align:start position:0% +order of magnitude in term in terms of +the probability + + align:start position:0% +the probability + + + align:start position:0% +the probability +distribution + + align:start position:0% +distribution + + + align:start position:0% +distribution +right + + align:start position:0% + + + + align:start position:0% + +okay all right so so all right so this + + align:start position:0% +okay all right so so all right so this + + + align:start position:0% +okay all right so so all right so this +is an observation and and where barbos + + align:start position:0% +is an observation and and where barbos + + + align:start position:0% +is an observation and and where barbos +came in and said all right well what + + align:start position:0% +came in and said all right well what + + + align:start position:0% +came in and said all right well what +would be a model that would recapitulate + + align:start position:0% +would be a model that would recapitulate + + + align:start position:0% +would be a model that would recapitulate +this okay and and what are the models + + align:start position:0% +this okay and and what are the models + + + align:start position:0% +this okay and and what are the models +that uh that did not recapitulate + + align:start position:0% + + + + align:start position:0% + +it right so the Eros sheni okay so uh so + + align:start position:0% +it right so the Eros sheni okay so uh so + + + align:start position:0% +it right so the Eros sheni okay so uh so +other um other models right there was + + align:start position:0% +other um other models right there was + + + align:start position:0% +other um other models right there was +the ER other + + align:start position:0% + + + + align:start position:0% + +models there was the soal Eros reny + + align:start position:0% +models there was the soal Eros reny + + + align:start position:0% +models there was the soal Eros reny +Network um random + + align:start position:0% + + + + align:start position:0% + +Network okay right and that's uh because + + align:start position:0% +Network okay right and that's uh because + + + align:start position:0% +Network okay right and that's uh because +the here the the degree distribution is + + align:start position:0% +the here the the degree distribution is + + + align:start position:0% +the here the the degree distribution is +peaked around something and then falls + + align:start position:0% +peaked around something and then falls + + + align:start position:0% +peaked around something and then falls +off exponentially as you go above that + + align:start position:0% +off exponentially as you go above that + + + align:start position:0% +off exponentially as you go above that +um and this is actually where the I + + align:start position:0% +um and this is actually where the I + + + align:start position:0% +um and this is actually where the I +think the equations are wrong in terms + + align:start position:0% +think the equations are wrong in terms + + + align:start position:0% +think the equations are wrong in terms +in this in this paper um because you + + align:start position:0% +in this in this paper um because you + + + align:start position:0% +in this in this paper um because you +know if if you look at the paper page + + align:start position:0% +know if if you look at the paper page + + + align:start position:0% +know if if you look at the paper page +510 right they say the Eros Reni uh you + + align:start position:0% +510 right they say the Eros Reni uh you + + + align:start position:0% +510 right they say the Eros Reni uh you +connect the edges with p and then they + + align:start position:0% +connect the edges with p and then they + + + align:start position:0% +connect the edges with p and then they +say uh you get a Pon distribution P of K + + align:start position:0% +say uh you get a Pon distribution P of K + + + align:start position:0% +say uh you get a Pon distribution P of K +where you where Lambda the mean is + + align:start position:0% +where you where Lambda the mean is + + + align:start position:0% +where you where Lambda the mean is +something but then they say oh Lambda is + + align:start position:0% +something but then they say oh Lambda is + + + align:start position:0% +something but then they say oh Lambda is +equal to some binomial something of K + + align:start position:0% +equal to some binomial something of K + + + align:start position:0% +equal to some binomial something of K +and so forth um so I think that this is + + align:start position:0% +and so forth um so I think that this is + + + align:start position:0% +and so forth um so I think that this is +all not true but rather that it um you + + align:start position:0% +all not true but rather that it um you + + + align:start position:0% +all not true but rather that it um you +can approximate the binomial with a Pon + + align:start position:0% +can approximate the binomial with a Pon + + + align:start position:0% +can approximate the binomial with a Pon +and the limit of small + + align:start position:0% + + + + align:start position:0% + +PS okay so beware if you're um looking + + align:start position:0% +PS okay so beware if you're um looking + + + align:start position:0% +PS okay so beware if you're um looking +at that + + align:start position:0% +at that + + + align:start position:0% +at that +um all right there there was another + + align:start position:0% +um all right there there was another + + + align:start position:0% +um all right there there was another +Network that uh that oh do you have a + + align:start position:0% +Network that uh that oh do you have a + + + align:start position:0% +Network that uh that oh do you have a +question um all right so we'll you know + + align:start position:0% +question um all right so we'll you know + + + align:start position:0% +question um all right so we'll you know +we'll you know we we're going to spend a + + align:start position:0% +we'll you know we we're going to spend a + + + align:start position:0% +we'll you know we we're going to spend a +lot of time talking about probity + + align:start position:0% +lot of time talking about probity + + + align:start position:0% +lot of time talking about probity +distributions in the coming weeks but I + + align:start position:0% +distributions in the coming weeks but I + + + align:start position:0% +distributions in the coming weeks but I +just wanted to highlight that there is + + align:start position:0% +just wanted to highlight that there is + + + align:start position:0% +just wanted to highlight that there is +as far as I can tell that that is not + + align:start position:0% +as far as I can tell that that is not + + + align:start position:0% +as far as I can tell that that is not +true what they say um all right but + + align:start position:0% +true what they say um all right but + + + align:start position:0% +true what they say um all right but +there there there was one other uh model + + align:start position:0% +there there there was one other uh model + + + align:start position:0% +there there there was one other uh model +for a network that they they talk about + + align:start position:0% +for a network that they they talk about + + + align:start position:0% +for a network that they they talk about +or they mention does any anybody small + + align:start position:0% +or they mention does any anybody small + + + align:start position:0% +or they mention does any anybody small +the so-called small world Network right + + align:start position:0% +the so-called small world Network right + + + align:start position:0% +the so-called small world Network right +um and this is + + align:start position:0% +um and this is + + + align:start position:0% +um and this is +um small world Network and this this is + + align:start position:0% +um small world Network and this this is + + + align:start position:0% +um small world Network and this this is +based on a paper by + + align:start position:0% +based on a paper by + + + align:start position:0% +based on a paper by +stroets + + align:start position:0% +stroets + + + align:start position:0% +stroets +and yeah watts and stroat Okay small + + align:start position:0% +and yeah watts and stroat Okay small + + + align:start position:0% +and yeah watts and stroat Okay small +world that's + + align:start position:0% +world that's + + + align:start position:0% +world that's +watts and + + align:start position:0% +watts and + + + align:start position:0% +watts and +stroots right and and and and this this + + align:start position:0% +stroots right and and and and this this + + + align:start position:0% +stroots right and and and and this this +is this was a paper where they they + + align:start position:0% +is this was a paper where they they + + + align:start position:0% +is this was a paper where they they +demonstrated that there was a very + + align:start position:0% +demonstrated that there was a very + + + align:start position:0% +demonstrated that there was a very +simple mechanism uh just by kind of like + + align:start position:0% +simple mechanism uh just by kind of like + + + align:start position:0% +simple mechanism uh just by kind of like +rewind ing a network that you could get + + align:start position:0% +rewind ing a network that you could get + + + align:start position:0% +rewind ing a network that you could get +this so-called small world phenomenon + + align:start position:0% +this so-called small world phenomenon + + + align:start position:0% +this so-called small world phenomenon +right where uh you know the Kevin Bacon + + align:start position:0% +right where uh you know the Kevin Bacon + + + align:start position:0% +right where uh you know the Kevin Bacon +thing where you can take any you can + + align:start position:0% +thing where you can take any you can + + + align:start position:0% +thing where you can take any you can +right from Kevin Bacon and this is + + align:start position:0% +right from Kevin Bacon and this is + + + align:start position:0% +right from Kevin Bacon and this is +actually the actor Network right so you + + align:start position:0% +actually the actor Network right so you + + + align:start position:0% +actually the actor Network right so you +can say starting with Kevin Bacon can + + align:start position:0% +can say starting with Kevin Bacon can + + + align:start position:0% +can say starting with Kevin Bacon can +you construct um a list of actors that + + align:start position:0% +you construct um a list of actors that + + + align:start position:0% +you construct um a list of actors that +co-starred with each person that gets + + align:start position:0% +co-starred with each person that gets + + + align:start position:0% +co-starred with each person that gets +you to Any Given actor and the statement + + align:start position:0% +you to Any Given actor and the statement + + + align:start position:0% +you to Any Given actor and the statement +is you're supposed to be able to do that + + align:start position:0% +is you're supposed to be able to do that + + + align:start position:0% +is you're supposed to be able to do that +from you know a path of six right so + + align:start position:0% +from you know a path of six right so + + + align:start position:0% +from you know a path of six right so +that you know all the actors are + + align:start position:0% +that you know all the actors are + + + align:start position:0% +that you know all the actors are +supposed to be connected to Kevin Bacon + + align:start position:0% +supposed to be connected to Kevin Bacon + + + align:start position:0% +supposed to be connected to Kevin Bacon +by six right um although maybe you guys + + align:start position:0% +by six right um although maybe you guys + + + align:start position:0% +by six right um although maybe you guys +don't even remember who Kevin Kevin + + align:start position:0% +don't even remember who Kevin Kevin + + + align:start position:0% +don't even remember who Kevin Kevin +Bacon is anymore is it oh you do okay + + align:start position:0% +Bacon is anymore is it oh you do okay + + + align:start position:0% +Bacon is anymore is it oh you do okay +all right um no but this rule works for + + align:start position:0% +all right um no but this rule works for + + + align:start position:0% +all right um no but this rule works for +anybody so just you know in you know + + align:start position:0% +anybody so just you know in you know + + + align:start position:0% +anybody so just you know in you know +insert your favorite actor into that + + align:start position:0% +insert your favorite actor into that + + + align:start position:0% +insert your favorite actor into that +sentence + + align:start position:0% +sentence + + + align:start position:0% +sentence +um okay and it's important I just just + + align:start position:0% +um okay and it's important I just just + + + align:start position:0% +um okay and it's important I just just +to mention that just because something + + align:start position:0% +to mention that just because something + + + align:start position:0% +to mention that just because something +is a small world network does not mean + + align:start position:0% +is a small world network does not mean + + + align:start position:0% +is a small world network does not mean +that it's it has power law distributions + + align:start position:0% +that it's it has power law distributions + + + align:start position:0% +that it's it has power law distributions +right it may be the case that many power + + align:start position:0% +right it may be the case that many power + + + align:start position:0% +right it may be the case that many power +law networks also have this small world + + align:start position:0% +law networks also have this small world + + + align:start position:0% +law networks also have this small world +character + + align:start position:0% +character + + + align:start position:0% +character +and I'd say maybe even most of them + + align:start position:0% +and I'd say maybe even most of them + + + align:start position:0% +and I'd say maybe even most of them +right because some of those highly + + align:start position:0% +right because some of those highly + + + align:start position:0% +right because some of those highly +connected nodes are going to be useful + + align:start position:0% +connected nodes are going to be useful + + + align:start position:0% +connected nodes are going to be useful +for connecting any anybody to anybody + + align:start position:0% +for connecting any anybody to anybody + + + align:start position:0% +for connecting any anybody to anybody +else but that's not required to get the + + align:start position:0% +else but that's not required to get the + + + align:start position:0% +else but that's not required to get the +small world + + align:start position:0% +small world + + + align:start position:0% +small world +character + + align:start position:0% +character + + + align:start position:0% +character +okay any questions about that + + align:start position:0% + + + + align:start position:0% + +statement question so you can't go from + + align:start position:0% +statement question so you can't go from + + + align:start position:0% +statement question so you can't go from +this small statement strong statement + + align:start position:0% +this small statement strong statement + + + align:start position:0% +this small statement strong statement +conc + + align:start position:0% +conc + + + align:start position:0% +conc +connectivity um + + align:start position:0% +connectivity um + + + align:start position:0% +connectivity um +well I I guess the strong statement is + + align:start position:0% +well I I guess the strong statement is + + + align:start position:0% +well I I guess the strong statement is +that um that this property does not + + align:start position:0% +that um that this property does not + + + align:start position:0% +that um that this property does not +imply that property right I guess yeah + + align:start position:0% +imply that property right I guess yeah + + + align:start position:0% +imply that property right I guess yeah +you're not say the + + align:start position:0% +you're not say the + + + align:start position:0% +you're not say the +invers yeah you know and that seems + + align:start position:0% +invers yeah you know and that seems + + + align:start position:0% +invers yeah you know and that seems +Seems + + align:start position:0% +Seems + + + align:start position:0% +Seems +exed yeah no I I AG I think that this + + align:start position:0% +exed yeah no I I AG I think that this + + + align:start position:0% +exed yeah no I I AG I think that this +small world property that's why I was + + align:start position:0% +small world property that's why I was + + + align:start position:0% +small world property that's why I was +saying + + align:start position:0% +saying + + + align:start position:0% +saying +that + + align:start position:0% +that + + + align:start position:0% +that +it's okay what I do not know is whether + + align:start position:0% +it's okay what I do not know is whether + + + align:start position:0% +it's okay what I do not know is whether +it would be possible to construct a uh a + + align:start position:0% +it would be possible to construct a uh a + + + align:start position:0% +it would be possible to construct a uh a +power law distributed Network that does + + align:start position:0% +power law distributed Network that does + + + align:start position:0% +power law distributed Network that does +not have the small world property but + + align:start position:0% +not have the small world property but + + + align:start position:0% +not have the small world property but +what I would say is that uh the ones + + align:start position:0% +what I would say is that uh the ones + + + align:start position:0% +what I would say is that uh the ones +that I'm aware of would have the small + + align:start position:0% +that I'm aware of would have the small + + + align:start position:0% +that I'm aware of would have the small +world property + + align:start position:0% + + + + align:start position:0% + +right any other questions about where + + align:start position:0% +right any other questions about where + + + align:start position:0% +right any other questions about where +where we are right so there's + + align:start position:0% +where we are right so there's + + + align:start position:0% +where we are right so there's +interesting properties of networks that + + align:start position:0% +interesting properties of networks that + + + align:start position:0% +interesting properties of networks that +we would like to explain right and um I + + align:start position:0% +we would like to explain right and um I + + + align:start position:0% +we would like to explain right and um I +would say that what uh what this paper + + align:start position:0% +would say that what uh what this paper + + + align:start position:0% +would say that what uh what this paper +does I think kind of convincingly is + + align:start position:0% +does I think kind of convincingly is + + + align:start position:0% +does I think kind of convincingly is +that they demonstrate that at least this + + align:start position:0% +that they demonstrate that at least this + + + align:start position:0% +that they demonstrate that at least this +model and we'll get into the assumptions + + align:start position:0% +model and we'll get into the assumptions + + + align:start position:0% +model and we'll get into the assumptions +does lead to a power law distributed + + align:start position:0% +does lead to a power law distributed + + + align:start position:0% +does lead to a power law distributed +Network okay um now uh in the um there + + align:start position:0% +Network okay um now uh in the um there + + + align:start position:0% +Network okay um now uh in the um there +was + + align:start position:0% +was + + + align:start position:0% +was +uh yeah there the the answer to the + + align:start position:0% +uh yeah there the the answer to the + + + align:start position:0% +uh yeah there the the answer to the +reading questions about about whether + + align:start position:0% +reading questions about about whether + + + align:start position:0% +reading questions about about whether +both of these is strictly necessary I + + align:start position:0% +both of these is strictly necessary I + + + align:start position:0% +both of these is strictly necessary I +think was it was an interesting one + + align:start position:0% +think was it was an interesting one + + + align:start position:0% +think was it was an interesting one +right and and I I'd say that this this + + align:start position:0% +right and and I I'd say that this this + + + align:start position:0% +right and and I I'd say that this this +gets into the wider issue of um you know + + align:start position:0% +gets into the wider issue of um you know + + + align:start position:0% +gets into the wider issue of um you know +there's a observation that is maybe + + align:start position:0% +there's a observation that is maybe + + + align:start position:0% +there's a observation that is maybe +interesting okay and then we want to + + align:start position:0% +interesting okay and then we want to + + + align:start position:0% +interesting okay and then we want to +understand why that might be and you + + align:start position:0% +understand why that might be and you + + + align:start position:0% +understand why that might be and you +then then what you can do is you can + + align:start position:0% +then then what you can do is you can + + + align:start position:0% +then then what you can do is you can +write down a model that leads to that + + align:start position:0% +write down a model that leads to that + + + align:start position:0% +write down a model that leads to that +behavior okay we've already talked about + + align:start position:0% +behavior okay we've already talked about + + + align:start position:0% +behavior okay we've already talked about +this does that prove that the + + align:start position:0% +this does that prove that the + + + align:start position:0% +this does that prove that the +assumptions of the model are + + align:start position:0% +assumptions of the model are + + + align:start position:0% +assumptions of the model are +correct no in this case these are pretty + + align:start position:0% +correct no in this case these are pretty + + + align:start position:0% +correct no in this case these are pretty +generic features of lots and lots of the + + align:start position:0% +generic features of lots and lots of the + + + align:start position:0% +generic features of lots and lots of the +network so we we tend not so we I'd say + + align:start position:0% +network so we we tend not so we I'd say + + + align:start position:0% +network so we we tend not so we I'd say +when you read it you kind of believe + + align:start position:0% +when you read it you kind of believe + + + align:start position:0% +when you read it you kind of believe +that this is a dominant mechanism but it + + align:start position:0% +that this is a dominant mechanism but it + + + align:start position:0% +that this is a dominant mechanism but it +it very much does not prove that these + + align:start position:0% +it very much does not prove that these + + + align:start position:0% +it very much does not prove that these +are the only this you know this is not + + align:start position:0% +are the only this you know this is not + + + align:start position:0% +are the only this you know this is not +at all the only way to get a power law + + align:start position:0% +at all the only way to get a power law + + + align:start position:0% +at all the only way to get a power law +distributed Network right and I'd say + + align:start position:0% +distributed Network right and I'd say + + + align:start position:0% +distributed Network right and I'd say +that some of the language in the paper + + align:start position:0% +that some of the language in the paper + + + align:start position:0% +that some of the language in the paper +might kind of lead you to believe that + + align:start position:0% +might kind of lead you to believe that + + + align:start position:0% +might kind of lead you to believe that +that is the case and I think that that's + + align:start position:0% +that is the case and I think that that's + + + align:start position:0% +that is the case and I think that that's +you know this is a standard logical + + align:start position:0% +you know this is a standard logical + + + align:start position:0% +you know this is a standard logical +fallacy that we have to be careful of + + align:start position:0% +fallacy that we have to be careful of + + + align:start position:0% +fallacy that we have to be careful of +and some of and I think that some of the + + align:start position:0% +and some of and I think that some of the + + + align:start position:0% +and some of and I think that some of the +language is a little bit dangerous you + + align:start position:0% +language is a little bit dangerous you + + + align:start position:0% +language is a little bit dangerous you +know so the de development of the power + + align:start position:0% +know so the de development of the power + + + align:start position:0% +know so the de development of the power +law scaling of the model indicates that + + align:start position:0% +law scaling of the model indicates that + + + align:start position:0% +law scaling of the model indicates that +growth and preferential attachment play + + align:start position:0% +growth and preferential attachment play + + + align:start position:0% +growth and preferential attachment play +an important role ink you know I you + + align:start position:0% +an important role ink you know I you + + + align:start position:0% +an important role ink you know I you +know I would say that it's it's I think + + align:start position:0% +know I would say that it's it's I think + + + align:start position:0% +know I would say that it's it's I think +it's probably true but you know but once + + align:start position:0% +it's probably true but you know but once + + + align:start position:0% +it's probably true but you know but once +again you know it's a question of this + + align:start position:0% +again you know it's a question of this + + + align:start position:0% +again you know it's a question of this +is certainly not a proof that th that + + align:start position:0% +is certainly not a proof that th that + + + align:start position:0% +is certainly not a proof that th that +those assumptions are relevant for any + + align:start position:0% +those assumptions are relevant for any + + + align:start position:0% +those assumptions are relevant for any +given network of + + align:start position:0% +given network of + + + align:start position:0% +given network of +course in all these cases the network + + align:start position:0% +course in all these cases the network + + + align:start position:0% +course in all these cases the network +does grow and there is preferential ATT + + align:start position:0% +does grow and there is preferential ATT + + + align:start position:0% +does grow and there is preferential ATT +attachment um but you know it's also + + align:start position:0% +attachment um but you know it's also + + + align:start position:0% +attachment um but you know it's also +there are other things that are also + + align:start position:0% +there are other things that are also + + + align:start position:0% +there are other things that are also +true that may be important for example + + align:start position:0% +true that may be important for example + + + align:start position:0% +true that may be important for example +in determining exactly what Alpha is or + + align:start position:0% +in determining exactly what Alpha is or + + + align:start position:0% +in determining exactly what Alpha is or +other things and and I think that as + + align:start position:0% +other things and and I think that as + + + align:start position:0% +other things and and I think that as +indicated that there are uh other ways + + align:start position:0% +indicated that there are uh other ways + + + align:start position:0% +indicated that there are uh other ways +of getting power lot networks without + + align:start position:0% +of getting power lot networks without + + + align:start position:0% +of getting power lot networks without +making the exact assumptions that are + + align:start position:0% +making the exact assumptions that are + + + align:start position:0% +making the exact assumptions that are +here but I think it it's um it's in my + + align:start position:0% +here but I think it it's um it's in my + + + align:start position:0% +here but I think it it's um it's in my +mind probably you know a or the dominant + + align:start position:0% +mind probably you know a or the dominant + + + align:start position:0% +mind probably you know a or the dominant +mechanism for in a lot of these networks + + align:start position:0% +mechanism for in a lot of these networks + + + align:start position:0% +mechanism for in a lot of these networks +so I I I think it's a it's a fine paper + + align:start position:0% +so I I I think it's a it's a fine paper + + + align:start position:0% +so I I I think it's a it's a fine paper +but just remember that it doesn't it + + align:start position:0% +but just remember that it doesn't it + + + align:start position:0% +but just remember that it doesn't it +doesn't prove that those are the two the + + align:start position:0% +doesn't prove that those are the two the + + + align:start position:0% +doesn't prove that those are the two the +only two important things right + + align:start position:0% +only two important things right + + + align:start position:0% +only two important things right +um yes just about the preferential + + align:start position:0% +um yes just about the preferential + + + align:start position:0% +um yes just about the preferential +attachments like I think you mentioned + + align:start position:0% +attachments like I think you mentioned + + + align:start position:0% +attachments like I think you mentioned +that we tried yes only yeah yeah this is + + align:start position:0% +that we tried yes only yeah yeah this is + + + align:start position:0% +that we tried yes only yeah yeah this is +a + + align:start position:0% +a + + + align:start position:0% +a +troubling yeah yeah I I agree I agree uh + + align:start position:0% +troubling yeah yeah I I agree I agree uh + + + align:start position:0% +troubling yeah yeah I I agree I agree uh +right so uh right and what they what + + align:start position:0% +right so uh right and what they what + + + align:start position:0% +right so uh right and what they what +they assume + + align:start position:0% +they assume + + + align:start position:0% +they assume +in in the model here is that that the + + align:start position:0% +in in the model here is that that the + + + align:start position:0% +in in the model here is that that the +preferential attachment goes linearly + + align:start position:0% +preferential attachment goes linearly + + + align:start position:0% +preferential attachment goes linearly +with the um the number of existing uh + + align:start position:0% +with the um the number of existing uh + + + align:start position:0% +with the um the number of existing uh +edges right and I would say that I very + + align:start position:0% +edges right and I would say that I very + + + align:start position:0% +edges right and I would say that I very +much believe that preferential + + align:start position:0% +much believe that preferential + + + align:start position:0% +much believe that preferential +attachment is present in all those + + align:start position:0% +attachment is present in all those + + + align:start position:0% +attachment is present in all those +things but I'm sure that if you go and + + align:start position:0% +things but I'm sure that if you go and + + + align:start position:0% +things but I'm sure that if you go and +you measure it you're not going to find + + align:start position:0% +you measure it you're not going to find + + + align:start position:0% +you measure it you're not going to find +that it's linear with the number of + + align:start position:0% +that it's linear with the number of + + + align:start position:0% +that it's linear with the number of +edges it's going to I mean okay I + + align:start position:0% +edges it's going to I mean okay I + + + align:start position:0% +edges it's going to I mean okay I +actually I don't know what you'll find + + align:start position:0% +actually I don't know what you'll find + + + align:start position:0% +actually I don't know what you'll find +in each of those cases but there's no + + align:start position:0% +in each of those cases but there's no + + + align:start position:0% +in each of those cases but there's no +reason to believe it has to be linear + + align:start position:0% +reason to believe it has to be linear + + + align:start position:0% +reason to believe it has to be linear +right that being said it may be the + + align:start position:0% +right that being said it may be the + + + align:start position:0% +right that being said it may be the +question is how strong of a deviation + + align:start position:0% +question is how strong of a deviation + + + align:start position:0% +question is how strong of a deviation +from linearity is there and then how + + align:start position:0% +from linearity is there and then how + + + align:start position:0% +from linearity is there and then how +sensitive is the power law Behavior to + + align:start position:0% +sensitive is the power law Behavior to + + + align:start position:0% +sensitive is the power law Behavior to +that and and that's the kind of thing + + align:start position:0% +that and and that's the kind of thing + + + align:start position:0% +that and and that's the kind of thing +that I'm sure that that uh one of the + + align:start position:0% +that I'm sure that that uh one of the + + + align:start position:0% +that I'm sure that that uh one of the +20,000 papers that have cited this paper + + align:start position:0% +20,000 papers that have cited this paper + + + align:start position:0% +20,000 papers that have cited this paper +in the last 15 years address this issue + + align:start position:0% +in the last 15 years address this issue + + + align:start position:0% +in the last 15 years address this issue +right um yeah no but I mean this is also + + align:start position:0% +right um yeah no but I mean this is also + + + align:start position:0% +right um yeah no but I mean this is also +why there are so many papers I mean it's + + align:start position:0% +why there are so many papers I mean it's + + + align:start position:0% +why there are so many papers I mean it's +like you read thiser like oh you know it + + align:start position:0% +like you read thiser like oh you know it + + + align:start position:0% +like you read thiser like oh you know it +would be really interesting to do this + + align:start position:0% +would be really interesting to do this + + + align:start position:0% +would be really interesting to do this +that you know and and people have been + + align:start position:0% +that you know and and people have been + + + align:start position:0% +that you know and and people have been +following that interest + + align:start position:0% + + + + align:start position:0% + +right okay let let's go and uh I think + + align:start position:0% +right okay let let's go and uh I think + + + align:start position:0% +right okay let let's go and uh I think +that the derivation is is a little bit + + align:start position:0% +that the derivation is is a little bit + + + align:start position:0% +that the derivation is is a little bit +tricky U so I think it's worth you know + + align:start position:0% +tricky U so I think it's worth you know + + + align:start position:0% +tricky U so I think it's worth you know +just walking through + + align:start position:0% +just walking through + + + align:start position:0% +just walking through +it um especially since some people + + align:start position:0% +it um especially since some people + + + align:start position:0% +it um especially since some people +apparently couldn't even get the + + align:start position:0% +apparently couldn't even get the + + + align:start position:0% +apparently couldn't even get the +equations which are going to be is going + + align:start position:0% +equations which are going to be is going + + + align:start position:0% +equations which are going to be is going +to it's going to be a problem + + align:start position:0% + + + + align:start position:0% + +oh and maybe while we're on this + + align:start position:0% +oh and maybe while we're on this + + + align:start position:0% +oh and maybe while we're on this +question of preferential attachment + + align:start position:0% + + + + align:start position:0% + +um how do you guys feel about this + + align:start position:0% +um how do you guys feel about this + + + align:start position:0% +um how do you guys feel about this +question of uh networks within say the + + align:start position:0% +question of uh networks within say the + + + align:start position:0% +question of uh networks within say the +trans the transcriptional network of + + align:start position:0% +trans the transcriptional network of + + + align:start position:0% +trans the transcriptional network of +eoli or other cells I mean do you think + + align:start position:0% +eoli or other cells I mean do you think + + + align:start position:0% +eoli or other cells I mean do you think +that these these properties are are are + + align:start position:0% +that these these properties are are are + + + align:start position:0% +that these these properties are are are +relevant in the cell or + + align:start position:0% + + + + align:start position:0% + +right so what would what would growth + + align:start position:0% + + + + align:start position:0% + +mean right so growth would correspond to + + align:start position:0% +mean right so growth would correspond to + + + align:start position:0% +mean right so growth would correspond to +adding a new Gene does that ever + + align:start position:0% +adding a new Gene does that ever + + + align:start position:0% +adding a new Gene does that ever +happen okay and what uh can someone give + + align:start position:0% +happen okay and what uh can someone give + + + align:start position:0% +happen okay and what uh can someone give +an a possible mechanism by which a new + + align:start position:0% +an a possible mechanism by which a new + + + align:start position:0% +an a possible mechanism by which a new +Gene is added to the + + align:start position:0% +Gene is added to the + + + align:start position:0% +Gene is added to the +genome right so for example duplication + + align:start position:0% +genome right so for example duplication + + + align:start position:0% +genome right so for example duplication +is common + + align:start position:0% +is common + + + align:start position:0% +is common +right EG + + align:start position:0% + + + + align:start position:0% + +duplication and so what is this + + align:start position:0% +duplication and so what is this + + + align:start position:0% +duplication and so what is this +mean for preferential + + align:start position:0% + + + + align:start position:0% + +attachment sorry my phone is we have d + + align:start position:0% +attachment sorry my phone is we have d + + + align:start position:0% +attachment sorry my phone is we have d +the probably also duplicate the + + align:start position:0% +the probably also duplicate the + + + align:start position:0% +the probably also duplicate the +which right so this I think is very + + align:start position:0% +which right so this I think is very + + + align:start position:0% +which right so this I think is very +interesting um right so + + align:start position:0% +interesting um right so + + + align:start position:0% +interesting um right so +duplication you know in general you'll + + align:start position:0% +duplication you know in general you'll + + + align:start position:0% +duplication you know in general you'll +duplicate both the coding region that + + align:start position:0% +duplicate both the coding region that + + + align:start position:0% +duplicate both the coding region that +makes the protein but also maybe the + + align:start position:0% +makes the protein but also maybe the + + + align:start position:0% +makes the protein but also maybe the +promoter region that specifies the + + align:start position:0% +promoter region that specifies the + + + align:start position:0% +promoter region that specifies the +regulation right so if you imagine you + + align:start position:0% +regulation right so if you imagine you + + + align:start position:0% +regulation right so if you imagine you +have some X here that is right and and + + align:start position:0% +have some X here that is right and and + + + align:start position:0% +have some X here that is right and and +we can remind ourselves uh are both the + + align:start position:0% +we can remind ourselves uh are both the + + + align:start position:0% +we can remind ourselves uh are both the +incoming and outgoing edges power LW + + align:start position:0% +incoming and outgoing edges power LW + + + align:start position:0% +incoming and outgoing edges power LW +distributed and transcription networks + + align:start position:0% +distributed and transcription networks + + + align:start position:0% +distributed and transcription networks +no I know this was in the this was the + + align:start position:0% +no I know this was in the this was the + + + align:start position:0% +no I know this was in the this was the +pre-class reading but just in case right + + align:start position:0% +pre-class reading but just in case right + + + align:start position:0% +pre-class reading but just in case right +so it the what you find is that some + + align:start position:0% +so it the what you find is that some + + + align:start position:0% +so it the what you find is that some +transcription factors regulate many + + align:start position:0% +transcription factors regulate many + + + align:start position:0% +transcription factors regulate many +genes but we don't have any any proteins + + align:start position:0% +genes but we don't have any any proteins + + + align:start position:0% +genes but we don't have any any proteins +that are regulated by 200 genes right so + + align:start position:0% +that are regulated by 200 genes right so + + + align:start position:0% +that are regulated by 200 genes right so +in that sense there + + align:start position:0% +in that sense there + + + align:start position:0% +in that sense there +typically right we have things that are + + align:start position:0% +typically right we have things that are + + + align:start position:0% +typically right we have things that are +regulated X there's maybe some X1 + + align:start position:0% +regulated X there's maybe some X1 + + + align:start position:0% +regulated X there's maybe some X1 +X2 X3 right and there might be a few + + align:start position:0% +X2 X3 right and there might be a few + + + align:start position:0% +X2 X3 right and there might be a few +incoming edges right so expression of a + + align:start position:0% +incoming edges right so expression of a + + + align:start position:0% +incoming edges right so expression of a +gene is is typically specified by a few + + align:start position:0% +gene is is typically specified by a few + + + align:start position:0% +gene is is typically specified by a few +transcription factors right whereas some + + align:start position:0% +transcription factors right whereas some + + + align:start position:0% +transcription factors right whereas some +transcription factors might have 100 + + align:start position:0% +transcription factors might have 100 + + + align:start position:0% +transcription factors might have 100 +outgoing edges okay so it's the outgoing + + align:start position:0% +outgoing edges okay so it's the outgoing + + + align:start position:0% +outgoing edges okay so it's the outgoing +edges that are power lot distributed and + + align:start position:0% +edges that are power lot distributed and + + + align:start position:0% +edges that are power lot distributed and +the ingoing you know are closer to being + + align:start position:0% +the ingoing you know are closer to being + + + align:start position:0% +the ingoing you know are closer to being +kind of Plus on or so all right so you + + align:start position:0% +kind of Plus on or so all right so you + + + align:start position:0% +kind of Plus on or so all right so you +can imagine that we have this guy might + + align:start position:0% +can imagine that we have this guy might + + + align:start position:0% +can imagine that we have this guy might +you know have 100 or so and whereas over + + align:start position:0% +you know have 100 or so and whereas over + + + align:start position:0% +you know have 100 or so and whereas over +here some y transcription factor that is + + align:start position:0% +here some y transcription factor that is + + + align:start position:0% +here some y transcription factor that is +just regulating two genes say y1 and Y + + align:start position:0% +just regulating two genes say y1 and Y + + + align:start position:0% +just regulating two genes say y1 and Y +two okay + + align:start position:0% +two okay + + + align:start position:0% +two okay +now question is if Gene duplication + + align:start position:0% +now question is if Gene duplication + + + align:start position:0% +now question is if Gene duplication +occurs kind of randomly throughout the + + align:start position:0% +occurs kind of randomly throughout the + + + align:start position:0% +occurs kind of randomly throughout the +genome you know + + align:start position:0% +genome you know + + + align:start position:0% +genome you know +which Target or you know which which + + align:start position:0% +which Target or you know which which + + + align:start position:0% +which Target or you know which which +transcription Factor X or Y is more + + align:start position:0% +transcription Factor X or Y is more + + + align:start position:0% +transcription Factor X or Y is more +likely to have a Target that's + + align:start position:0% + + + + align:start position:0% + +duplicated X all right interestingly how + + align:start position:0% +duplicated X all right interestingly how + + + align:start position:0% +duplicated X all right interestingly how +does that scale with the number of + + align:start position:0% +does that scale with the number of + + + align:start position:0% +does that scale with the number of +targets + + align:start position:0% + + + + align:start position:0% + +linear this actually is linear right so + + align:start position:0% +linear this actually is linear right so + + + align:start position:0% +linear this actually is linear right so +so I'd say that that Gene + + align:start position:0% +so I'd say that that Gene + + + align:start position:0% +so I'd say that that Gene +duplication does + + align:start position:0% +duplication does + + + align:start position:0% +duplication does +give growth and preferential attachment + + align:start position:0% +give growth and preferential attachment + + + align:start position:0% +give growth and preferential attachment +that is basically linear with the number + + align:start position:0% +that is basically linear with the number + + + align:start position:0% +that is basically linear with the number +of targets um it's interesting I I'd say + + align:start position:0% +of targets um it's interesting I I'd say + + + align:start position:0% +of targets um it's interesting I I'd say +I find + + align:start position:0% +I find + + + align:start position:0% +I find +this kind of + + align:start position:0% +this kind of + + + align:start position:0% +this kind of +observation quite interesting and + + align:start position:0% +observation quite interesting and + + + align:start position:0% +observation quite interesting and +compelling and makes me feel kind of + + align:start position:0% +compelling and makes me feel kind of + + + align:start position:0% +compelling and makes me feel kind of +comfortable about this as a mechanism + + align:start position:0% +comfortable about this as a mechanism + + + align:start position:0% +comfortable about this as a mechanism +for uh some of the global properties you + + align:start position:0% +for uh some of the global properties you + + + align:start position:0% +for uh some of the global properties you +know I mean this of course there's no + + align:start position:0% +know I mean this of course there's no + + + align:start position:0% +know I mean this of course there's no +selection there's no way to explain you + + align:start position:0% +selection there's no way to explain you + + + align:start position:0% +selection there's no way to explain you +know the interesting Network motifs and + + align:start position:0% +know the interesting Network motifs and + + + align:start position:0% +know the interesting Network motifs and +so forth here but I'd say just in terms + + align:start position:0% +so forth here but I'd say just in terms + + + align:start position:0% +so forth here but I'd say just in terms +of some general properties I think it's + + align:start position:0% +of some general properties I think it's + + + align:start position:0% +of some general properties I think it's +it's interesting of course once again + + align:start position:0% +it's interesting of course once again + + + align:start position:0% +it's interesting of course once again +not approve Evolution can do whatever it + + align:start position:0% +not approve Evolution can do whatever it + + + align:start position:0% +not approve Evolution can do whatever it +wants with these Gene duplication events + + align:start position:0% +wants with these Gene duplication events + + + align:start position:0% +wants with these Gene duplication events +um but you know so I would say you know + + align:start position:0% +um but you know so I would say you know + + + align:start position:0% +um but you know so I would say you know +not everybody finds this argument very + + align:start position:0% +not everybody finds this argument very + + + align:start position:0% +not everybody finds this argument very +uh very compelling but I'd say I think + + align:start position:0% +uh very compelling but I'd say I think + + + align:start position:0% +uh very compelling but I'd say I think +it's kind of I get a warm fuzzy feeling + + align:start position:0% +it's kind of I get a warm fuzzy feeling + + + align:start position:0% +it's kind of I get a warm fuzzy feeling +inside yeah about transcription Network + + align:start position:0% +inside yeah about transcription Network + + + align:start position:0% +inside yeah about transcription Network +it's different from the other networks + + align:start position:0% +it's different from the other networks + + + align:start position:0% +it's different from the other networks +we talking about that also lose Gen Y so + + align:start position:0% +we talking about that also lose Gen Y so + + + align:start position:0% +we talking about that also lose Gen Y so +is there any discussion well you know + + align:start position:0% +is there any discussion well you know + + + align:start position:0% +is there any discussion well you know +you can + + align:start position:0% +you can + + + align:start position:0% +you can +lose you can lose web pages you can you + + align:start position:0% +lose you can lose web pages you can you + + + align:start position:0% +lose you can lose web pages you can you +can + + align:start position:0% +can + + + align:start position:0% +can +areast + + align:start position:0% +areast + + + align:start position:0% +areast +as + + align:start position:0% +as + + + align:start position:0% +as +um yeah I I don't know um I find that + + align:start position:0% +um yeah I I don't know um I find that + + + align:start position:0% +um yeah I I don't know um I find that +you know you know lots of links to my + + align:start position:0% +you know you know lots of links to my + + + align:start position:0% +you know you know lots of links to my +web pages just disappear over time and I + + align:start position:0% +web pages just disappear over time and I + + + align:start position:0% +web pages just disappear over time and I +don't know yeah I I it's it's a + + align:start position:0% +don't know yeah I I it's it's a + + + align:start position:0% +don't know yeah I I it's it's a +reasonable question I um I don't + + align:start position:0% + + + + align:start position:0% + +right you know in some of these you'd + + align:start position:0% +right you know in some of these you'd + + + align:start position:0% +right you know in some of these you'd +say oh well right so the the web has + + align:start position:0% +say oh well right so the the web has + + + align:start position:0% +say oh well right so the the web has +been growing a lot recently and and and + + align:start position:0% +been growing a lot recently and and and + + + align:start position:0% +been growing a lot recently and and and +so then we'd say that birth dominates + + align:start position:0% +so then we'd say that birth dominates + + + align:start position:0% +so then we'd say that birth dominates +over death there whereas if you talk + + align:start position:0% +over death there whereas if you talk + + + align:start position:0% +over death there whereas if you talk +about genome sizes along different + + align:start position:0% +about genome sizes along different + + + align:start position:0% +about genome sizes along different +lineages it certainly is not growing + + align:start position:0% +lineages it certainly is not growing + + + align:start position:0% +lineages it certainly is not growing +exponentially the way the web yeah I + + align:start position:0% +exponentially the way the web yeah I + + + align:start position:0% +exponentially the way the web yeah I +think that that's fair and true um but + + align:start position:0% +think that that's fair and true um but + + + align:start position:0% +think that that's fair and true um but +we we haven't really actually specified + + align:start position:0% +we we haven't really actually specified + + + align:start position:0% +we we haven't really actually specified +or made clear within a model what + + align:start position:0% +or made clear within a model what + + + align:start position:0% +or made clear within a model what +happens if you allow for birth and death + + align:start position:0% +happens if you allow for birth and death + + + align:start position:0% +happens if you allow for birth and death +right um but I think that uh you you + + align:start position:0% +right um but I think that uh you you + + + align:start position:0% +right um but I think that uh you you +could introduce death and and + + align:start position:0% +could introduce death and and + + + align:start position:0% +could introduce death and and +recapitulate these behaviors so it's not + + align:start position:0% +recapitulate these behaviors so it's not + + + align:start position:0% +recapitulate these behaviors so it's not +I think that it's just because some + + align:start position:0% +I think that it's just because some + + + align:start position:0% +I think that it's just because some +nodes disappear doesn't mean that the + + align:start position:0% +nodes disappear doesn't mean that the + + + align:start position:0% +nodes disappear doesn't mean that the +whole we have to throw the whole idea + + align:start position:0% +whole we have to throw the whole idea + + + align:start position:0% +whole we have to throw the whole idea +out the + + align:start position:0% + + + + align:start position:0% + +window but um but you know evolu you + + align:start position:0% +window but um but you know evolu you + + + align:start position:0% +window but um but you know evolu you +know in the presence of evolution this + + align:start position:0% +know in the presence of evolution this + + + align:start position:0% +know in the presence of evolution this +is all very complicated right so I you + + align:start position:0% +is all very complicated right so I you + + + align:start position:0% +is all very complicated right so I you +know you can't carry this argument too + + align:start position:0% +know you can't carry this argument too + + + align:start position:0% +know you can't carry this argument too +far + + align:start position:0% +far + + + align:start position:0% +far +but um + + align:start position:0% +but um + + + align:start position:0% +but um +okay so it's linear + + align:start position:0% +okay so it's linear + + + align:start position:0% +okay so it's linear +if has + + align:start position:0% +if has + + + align:start position:0% +if has +one if well what we're assuming is that + + align:start position:0% +one if well what we're assuming is that + + + align:start position:0% +one if well what we're assuming is that +right there's + + align:start position:0% +right there's + + + align:start position:0% +right there's +some you know some segment of DNA that's + + align:start position:0% +some you know some segment of DNA that's + + + align:start position:0% +some you know some segment of DNA that's +in front of the gene that specifi gives + + align:start position:0% +in front of the gene that specifi gives + + + align:start position:0% +in front of the gene that specifi gives +instructions of when to make when to + + align:start position:0% +instructions of when to make when to + + + align:start position:0% +instructions of when to make when to +when to transcribe the the + + align:start position:0% +when to transcribe the the + + + align:start position:0% +when to transcribe the the +gene right so the linearity is just + + align:start position:0% +gene right so the linearity is just + + + align:start position:0% +gene right so the linearity is just +assuming that that's really just + + align:start position:0% +assuming that that's really just + + + align:start position:0% +assuming that that's really just +assuming that genes have kind of the + + align:start position:0% +assuming that genes have kind of the + + + align:start position:0% +assuming that genes have kind of the +same rate of being duplicated on average + + align:start position:0% +same rate of being duplicated on average + + + align:start position:0% +same rate of being duplicated on average +you know and this is a very Global + + align:start position:0% +you know and this is a very Global + + + align:start position:0% +you know and this is a very Global +property so I I think + + align:start position:0% +property so I I think + + + align:start position:0% +property so I I think +that it's you know it's kind of roughly + + align:start position:0% +that it's you know it's kind of roughly + + + align:start position:0% +that it's you know it's kind of roughly +it's a it's a it's I would say it's the + + align:start position:0% +it's a it's a it's I would say it's the + + + align:start position:0% +it's a it's a it's I would say it's the +n model that you would use if you're + + align:start position:0% +n model that you would use if you're + + + align:start position:0% +n model that you would use if you're +going if you had to write down a null + + align:start position:0% + + + + align:start position:0% + +model um + + align:start position:0% +model um + + + align:start position:0% +model um +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +support yeah that's an interesting + + align:start position:0% +support yeah that's an interesting + + + align:start position:0% +support yeah that's an interesting +question + + align:start position:0% +question + + + align:start position:0% +question +uh you know and it's hard to know what + + align:start position:0% +uh you know and it's hard to know what + + + align:start position:0% +uh you know and it's hard to know what +it would even mean to quite be evidenced + + align:start position:0% +it would even mean to quite be evidenced + + + align:start position:0% +it would even mean to quite be evidenced +to support it in the sense that uh + + align:start position:0% +to support it in the sense that uh + + + align:start position:0% +to support it in the sense that uh +you're you're saying along different + + align:start position:0% +you're you're saying along different + + + align:start position:0% +you're you're saying along different +evolutionary lineages could we um say + + align:start position:0% +evolutionary lineages could we um say + + + align:start position:0% +evolutionary lineages could we um say +that it's more likely to grow you know + + align:start position:0% +that it's more likely to grow you know + + + align:start position:0% +that it's more likely to grow you know +of course the other thing to say is that + + align:start position:0% +of course the other thing to say is that + + + align:start position:0% +of course the other thing to say is that +the the rate of of death would also + + align:start position:0% +the the rate of of death would also + + + align:start position:0% +the the rate of of death would also +scale linearly I mean the sense that if + + align:start position:0% +scale linearly I mean the sense that if + + + align:start position:0% +scale linearly I mean the sense that if +a gene being uh stochastically um + + align:start position:0% +a gene being uh stochastically um + + + align:start position:0% +a gene being uh stochastically um +removed from the genome should also + + align:start position:0% +removed from the genome should also + + + align:start position:0% +removed from the genome should also +scale linearly right so it's not that um + + align:start position:0% +scale linearly right so it's not that um + + + align:start position:0% +scale linearly right so it's not that um +you don't actually then expect there to + + align:start position:0% +you don't actually then expect there to + + + align:start position:0% +you don't actually then expect there to +be any um systematic change I mean it's + + align:start position:0% +be any um systematic change I mean it's + + + align:start position:0% +be any um systematic change I mean it's +not as simple as just saying oh the the + + align:start position:0% +not as simple as just saying oh the the + + + align:start position:0% +not as simple as just saying oh the the +the number of targets of um a + + align:start position:0% +the number of targets of um a + + + align:start position:0% +the number of targets of um a +transcription factor with many targets + + align:start position:0% +transcription factor with many targets + + + align:start position:0% +transcription factor with many targets +should grow faster you know it's really + + align:start position:0% +should grow faster you know it's really + + + align:start position:0% +should grow faster you know it's really +that the expectations is it should be + + align:start position:0% +that the expectations is it should be + + + align:start position:0% +that the expectations is it should be +changing faster because they're because + + align:start position:0% +changing faster because they're because + + + align:start position:0% +changing faster because they're because +both duplication and removal would both + + align:start position:0% +both duplication and removal would both + + + align:start position:0% +both duplication and removal would both +be increasing so I think the signature + + align:start position:0% +be increasing so I think the signature + + + align:start position:0% +be increasing so I think the signature +is not totally obvious in that + + align:start position:0% + + + + align:start position:0% + +sense all right so how many people + + align:start position:0% +sense all right so how many people + + + align:start position:0% +sense all right so how many people +actually tried to piece the piece this + + align:start position:0% +actually tried to piece the piece this + + + align:start position:0% +actually tried to piece the piece this +derivation apart + + align:start position:0% +derivation apart + + + align:start position:0% +derivation apart +anybody all right and did were you happy + + align:start position:0% +anybody all right and did were you happy + + + align:start position:0% +anybody all right and did were you happy +with it at the end of your I think so an + + align:start position:0% +with it at the end of your I think so an + + + align:start position:0% +with it at the end of your I think so an +assumtion near the very end that I was a + + align:start position:0% +assumtion near the very end that I was a + + + align:start position:0% +assumtion near the very end that I was a +little bit okay yeah know it kind of you + + align:start position:0% +little bit okay yeah know it kind of you + + + align:start position:0% +little bit okay yeah know it kind of you +know there is like a Croc of the climb + + align:start position:0% +know there is like a Croc of the climb + + + align:start position:0% +know there is like a Croc of the climb +at the end all right um okay so um all + + align:start position:0% +at the end all right um okay so um all + + + align:start position:0% +at the end all right um okay so um all +right let's just make sure that we um + + align:start position:0% +right let's just make sure that we um + + + align:start position:0% +right let's just make sure that we um +you know we can understand kind of what + + align:start position:0% +you know we can understand kind of what + + + align:start position:0% +you know we can understand kind of what +happened there because it's it's worth + + align:start position:0% +happened there because it's it's worth + + + align:start position:0% +happened there because it's it's worth +you know since we read the paper it's + + align:start position:0% +you know since we read the paper it's + + + align:start position:0% +you know since we read the paper it's +worth trying to figure it out all right + + align:start position:0% +worth trying to figure it out all right + + + align:start position:0% +worth trying to figure it out all right +um okay so so what we're going to assume + + align:start position:0% +um okay so so what we're going to assume + + + align:start position:0% +um okay so so what we're going to assume +is that we + + align:start position:0% +is that we + + + align:start position:0% +is that we +start with uh M uh + + align:start position:0% +start with uh M uh + + + align:start position:0% +start with uh M uh +nodes okay so they're going to be here + + align:start position:0% +nodes okay so they're going to be here + + + align:start position:0% +nodes okay so they're going to be here +and the idea is that doesn't really + + align:start position:0% +and the idea is that doesn't really + + + align:start position:0% +and the idea is that doesn't really +matter how we start this thing they + + align:start position:0% +matter how we start this thing they + + + align:start position:0% +matter how we start this thing they +might start out being unconnected or + + align:start position:0% +might start out being unconnected or + + + align:start position:0% +might start out being unconnected or +they might be connected you know and + + align:start position:0% +they might be connected you know and + + + align:start position:0% +they might be connected you know and +over time you know the signature of how + + align:start position:0% +over time you know the signature of how + + + align:start position:0% +over time you know the signature of how +we start is not supposed to be that + + align:start position:0% +we start is not supposed to be that + + + align:start position:0% +we start is not supposed to be that +important right um and then what we're + + align:start position:0% +important right um and then what we're + + + align:start position:0% +important right um and then what we're +going to do is um at each time point + + align:start position:0% +going to do is um at each time point + + + align:start position:0% +going to do is um at each time point +we're going to add one more + + align:start position:0% +we're going to add one more + + + align:start position:0% +we're going to add one more +node and uh as we do that we're going to + + align:start position:0% +node and uh as we do that we're going to + + + align:start position:0% +node and uh as we do that we're going to +add uh M edges as well okay right so we + + align:start position:0% +add uh M edges as well okay right so we + + + align:start position:0% +add uh M edges as well okay right so we +can uh we then have the number of uh + + align:start position:0% +can uh we then have the number of uh + + + align:start position:0% +can uh we then have the number of uh +we'll say nodes and + + align:start position:0% +we'll say nodes and + + + align:start position:0% +we'll say nodes and +uh as a function of + + align:start position:0% +uh as a function of + + + align:start position:0% +uh as a function of +time is going to be equal to + + align:start position:0% + + + + align:start position:0% + +what all right this is just going to be + + align:start position:0% +what all right this is just going to be + + + align:start position:0% +what all right this is just going to be +we're going to start at m not and it's + + align:start position:0% +we're going to start at m not and it's + + + align:start position:0% +we're going to start at m not and it's +going to be we're going to add one each + + align:start position:0% +going to be we're going to add one each + + + align:start position:0% +going to be we're going to add one each +time m not plus T number of + + align:start position:0% +time m not plus T number of + + + align:start position:0% +time m not plus T number of +edges is just going to be equal to the + + align:start position:0% +edges is just going to be equal to the + + + align:start position:0% +edges is just going to be equal to the +number that we add each time Point times + + align:start position:0% +number that we add each time Point times + + + align:start position:0% +number that we add each time Point times +times the time okay right so here we're + + align:start position:0% +times the time okay right so here we're + + + align:start position:0% +times the time okay right so here we're +assuming that we start out with these + + align:start position:0% +assuming that we start out with these + + + align:start position:0% +assuming that we start out with these +nodes being + + align:start position:0% + + + + align:start position:0% + +unconnected now uh we're we're given the + + align:start position:0% +unconnected now uh we're we're given the + + + align:start position:0% +unconnected now uh we're we're given the +assumption that there's preferential + + align:start position:0% +assumption that there's preferential + + + align:start position:0% +assumption that there's preferential +attachment right so that means that the + + align:start position:0% +attachment right so that means that the + + + align:start position:0% +attachment right so that means that the +probability of connecting to uh this to + + align:start position:0% +probability of connecting to uh this to + + + align:start position:0% +probability of connecting to uh this to +some I node that has K edges is going to + + align:start position:0% +some I node that has K edges is going to + + + align:start position:0% +some I node that has K edges is going to +be K the I divided by the sum + + align:start position:0% + + + + align:start position:0% + +over um all of + + align:start position:0% +over um all of + + + align:start position:0% +over um all of +all of the + + align:start position:0% + + + + align:start position:0% + +edges + + align:start position:0% + + + + align:start position:0% + +yes all right so the assumption is that + + align:start position:0% +yes all right so the assumption is that + + + align:start position:0% +yes all right so the assumption is that +at each time point we add a new node + + align:start position:0% +at each time point we add a new node + + + align:start position:0% +at each time point we add a new node +let's say this node and with that we + + align:start position:0% +let's say this node and with that we + + + align:start position:0% +let's say this node and with that we +bring in some number M of new edges all + + align:start position:0% +bring in some number M of new edges all + + + align:start position:0% +bring in some number M of new edges all +right so this could be three and then we + + align:start position:0% +right so this could be three and then we + + + align:start position:0% +right so this could be three and then we +go randomly to three of the existing + + align:start position:0% +go randomly to three of the existing + + + align:start position:0% +go randomly to three of the existing +three of the existing nodes right so + + align:start position:0% +three of the existing nodes right so + + + align:start position:0% +three of the existing nodes right so +each time point we add M edges you add + + align:start position:0% +each time point we add M edges you add + + + align:start position:0% +each time point we add M edges you add +you necessarily add them to the + + align:start position:0% +you necessarily add them to the + + + align:start position:0% +you necessarily add them to the +new you + + align:start position:0% + + + + align:start position:0% + +connect + + align:start position:0% + + + + align:start position:0% + +um I'm sorry I don't understand oh yeah + + align:start position:0% +um I'm sorry I don't understand oh yeah + + + align:start position:0% +um I'm sorry I don't understand oh yeah +right so the assumption is that um is + + align:start position:0% +right so the assumption is that um is + + + align:start position:0% +right so the assumption is that um is +that the new the new node is indeed + + align:start position:0% +that the new the new node is indeed + + + align:start position:0% +that the new the new node is indeed +being connected to U right that all M + + align:start position:0% +being connected to U right that all M + + + align:start position:0% +being connected to U right that all M +edges that we're adding are to this new + + align:start position:0% +edges that we're adding are to this new + + + align:start position:0% +edges that we're adding are to this new +node + + align:start position:0% +node + + + align:start position:0% +node +yeah okay all right so this is the + + align:start position:0% +yeah okay all right so this is the + + + align:start position:0% +yeah okay all right so this is the +linear preferential attachment that we + + align:start position:0% +linear preferential attachment that we + + + align:start position:0% +linear preferential attachment that we +were talking about + + align:start position:0% + + + + align:start position:0% + +all + + align:start position:0% +all + + + align:start position:0% +all +right all right so what we want to know + + align:start position:0% +right all right so what we want to know + + + align:start position:0% +right all right so what we want to know +uh first is how um a after a node is is + + align:start position:0% +uh first is how um a after a node is is + + + align:start position:0% +uh first is how um a after a node is is +connected how is it that the number of + + align:start position:0% +connected how is it that the number of + + + align:start position:0% +connected how is it that the number of +edges will grow over + + align:start position:0% +edges will grow over + + + align:start position:0% +edges will grow over +time right what we know is that at when + + align:start position:0% +time right what we know is that at when + + + align:start position:0% +time right what we know is that at when +it's first added it has exactly M uh M + + align:start position:0% +it's first added it has exactly M uh M + + + align:start position:0% +it's first added it has exactly M uh M +edges right so but then but then as new + + align:start position:0% +edges right so but then but then as new + + + align:start position:0% +edges right so but then but then as new +nodes come then we'll maybe get some + + align:start position:0% +nodes come then we'll maybe get some + + + align:start position:0% +nodes come then we'll maybe get some +more and then it'll it'll + + align:start position:0% + + + + align:start position:0% + +grow and in particular we want to get um + + align:start position:0% +grow and in particular we want to get um + + + align:start position:0% +grow and in particular we want to get um +you know we're told that there's that + + align:start position:0% +you know we're told that there's that + + + align:start position:0% +you know we're told that there's that +it's going to grow as this differential + + align:start position:0% + + + + align:start position:0% + +equation okay so we want we want to kind + + align:start position:0% +equation okay so we want we want to kind + + + align:start position:0% +equation okay so we want we want to kind +of get to this all right and and the way + + align:start position:0% +of get to this all right and and the way + + + align:start position:0% +of get to this all right and and the way +to think about this is that all right + + align:start position:0% +to think about this is that all right + + + align:start position:0% +to think about this is that all right +well how is it that the number of edges + + align:start position:0% +well how is it that the number of edges + + + align:start position:0% +well how is it that the number of edges +will change at each time Point some + + align:start position:0% +will change at each time Point some + + + align:start position:0% +will change at each time Point some +Delta Ki right + + align:start position:0% +Delta Ki right + + + align:start position:0% +Delta Ki right +well the expected number of of edges + + align:start position:0% +well the expected number of of edges + + + align:start position:0% +well the expected number of of edges +that will be attached to some uh to some + + align:start position:0% +that will be attached to some uh to some + + + align:start position:0% +that will be attached to some uh to some +node well that's going to be uh the M + + align:start position:0% +node well that's going to be uh the M + + + align:start position:0% +node well that's going to be uh the M +this is the number of uh the number of + + align:start position:0% +this is the number of uh the number of + + + align:start position:0% +this is the number of uh the number of +edges that were attached by this + + align:start position:0% +edges that were attached by this + + + align:start position:0% +edges that were attached by this +incoming node and times this + + align:start position:0% +incoming node and times this + + + align:start position:0% +incoming node and times this +probability of attaching to this um to + + align:start position:0% +probability of attaching to this um to + + + align:start position:0% +probability of attaching to this um to +this node right so this is is the + + align:start position:0% +this node right so this is is the + + + align:start position:0% +this node right so this is is the +probability of + + align:start position:0% +probability of + + + align:start position:0% +probability of +Ki right now this is in one time + + align:start position:0% +Ki right now this is in one time + + + align:start position:0% +Ki right now this is in one time +step right so this is really a Delta Ki + + align:start position:0% +step right so this is really a Delta Ki + + + align:start position:0% +step right so this is really a Delta Ki +if we want we could say over some delta + + align:start position:0% +if we want we could say over some delta + + + align:start position:0% +if we want we could say over some delta +T which is one + + align:start position:0% +T which is one + + + align:start position:0% +T which is one +right so from that standpoint we can + + align:start position:0% +right so from that standpoint we can + + + align:start position:0% +right so from that standpoint we can +actually then write as a differential + + align:start position:0% +actually then write as a differential + + + align:start position:0% +actually then write as a differential +equation we you say the change in this + + align:start position:0% +equation we you say the change in this + + + align:start position:0% +equation we you say the change in this +number of edges with respect to time is + + align:start position:0% +number of edges with respect to time is + + + align:start position:0% +number of edges with respect to time is +indeed going to be equal to M + + align:start position:0% +indeed going to be equal to M + + + align:start position:0% +indeed going to be equal to M +* this guy + + align:start position:0% +* this guy + + + align:start position:0% +* this guy +here which + + align:start position:0% +here which + + + align:start position:0% +here which +is the number of edges that that that + + align:start position:0% +is the number of edges that that that + + + align:start position:0% +is the number of edges that that that +note has at this time divided by this + + align:start position:0% +note has at this time divided by this + + + align:start position:0% +note has at this time divided by this +sum + + align:start position:0% +sum + + + align:start position:0% +sum +over all those + + align:start position:0% +over all those + + + align:start position:0% +over all those +edges + + align:start position:0% + + + + align:start position:0% + +okay all right so this is just the kind + + align:start position:0% +okay all right so this is just the kind + + + align:start position:0% +okay all right so this is just the kind +of the expected number of edges to be + + align:start position:0% +of the expected number of edges to be + + + align:start position:0% +of the expected number of edges to be +added to that node at each time Point + + align:start position:0% +added to that node at each time Point + + + align:start position:0% +added to that node at each time Point +okay all right so but what what is this + + align:start position:0% +okay all right so but what what is this + + + align:start position:0% +okay all right so but what what is this +thing uh what is that thing equal to yes + + align:start position:0% + + + + align:start position:0% + +I + + align:start position:0% + + + + align:start position:0% + +did yeah so so this is kind of the + + align:start position:0% +did yeah so so this is kind of the + + + align:start position:0% +did yeah so so this is kind of the +discreet version of the differential of + + align:start position:0% +discreet version of the differential of + + + align:start position:0% +discreet version of the differential of +this differential equation right yeah + + align:start position:0% +this differential equation right yeah + + + align:start position:0% +this differential equation right yeah +that's right that's right yeah um and of + + align:start position:0% +that's right that's right yeah um and of + + + align:start position:0% +that's right that's right yeah um and of +course uh the beginning could be highly + + align:start position:0% +course uh the beginning could be highly + + + align:start position:0% +course uh the beginning could be highly +stochastic right but we're just we're + + align:start position:0% +stochastic right but we're just we're + + + align:start position:0% +stochastic right but we're just we're +just thinking about it in the limit of + + align:start position:0% +just thinking about it in the limit of + + + align:start position:0% +just thinking about it in the limit of +if if it's deterministic + + align:start position:0% +if if it's deterministic + + + align:start position:0% +if if it's deterministic +right right so what is this + + align:start position:0% +right right so what is this + + + align:start position:0% +right right so what is this +thing in terms I mean so from here this + + align:start position:0% +thing in terms I mean so from here this + + + align:start position:0% +thing in terms I mean so from here this +was just a normalization constant right + + align:start position:0% +was just a normalization constant right + + + align:start position:0% +was just a normalization constant right +because you know each Edge has to be + + align:start position:0% +because you know each Edge has to be + + + align:start position:0% +because you know each Edge has to be +attached somewhere we're assuming it's + + align:start position:0% +attached somewhere we're assuming it's + + + align:start position:0% +attached somewhere we're assuming it's +linear with respect to the number of + + align:start position:0% +linear with respect to the number of + + + align:start position:0% +linear with respect to the number of +edges at each node right and that means + + align:start position:0% +edges at each node right and that means + + + align:start position:0% +edges at each node right and that means +that for normalization we have + + align:start position:0% +that for normalization we have + + + align:start position:0% +that for normalization we have +to divide by the sum over all those + + align:start position:0% +to divide by the sum over all those + + + align:start position:0% +to divide by the sum over all those +edges right that the edges that each of + + align:start position:0% +edges right that the edges that each of + + + align:start position:0% +edges right that the edges that each of +the each of the nodes might have but how + + align:start position:0% +the each of the nodes might have but how + + + align:start position:0% +the each of the nodes might have but how +what is this thing equal to in terms of + + align:start position:0% +what is this thing equal to in terms of + + + align:start position:0% +what is this thing equal to in terms of +something else that we might have on the + + align:start position:0% +something else that we might have on the + + + align:start position:0% +something else that we might have on the +board yeah edges + + align:start position:0% +board yeah edges + + + align:start position:0% +board yeah edges +to right okay so I guess the question is + + align:start position:0% +to right okay so I guess the question is + + + align:start position:0% +to right okay so I guess the question is +well is this can we write + + align:start position:0% + + + + align:start position:0% + +this you know e where e is a function of + + align:start position:0% + + + + align:start position:0% + +time is is is that + + align:start position:0% +time is is is that + + + align:start position:0% +time is is is that +correct so we're getting + + align:start position:0% +correct so we're getting + + + align:start position:0% +correct so we're getting +shakes right so it's actually 2 + + align:start position:0% +shakes right so it's actually 2 + + + align:start position:0% +shakes right so it's actually 2 +e right because what you notice here is + + align:start position:0% +e right because what you notice here is + + + align:start position:0% +e right because what you notice here is +that this is the sum over all of the + + align:start position:0% +that this is the sum over all of the + + + align:start position:0% +that this is the sum over all of the +edges that each of the nodes have right + + align:start position:0% +edges that each of the nodes have right + + + align:start position:0% +edges that each of the nodes have right +but each Edge is connecting two nodes + + align:start position:0% +but each Edge is connecting two nodes + + + align:start position:0% +but each Edge is connecting two nodes +right so the sum over all these Edge + + align:start position:0% +right so the sum over all these Edge + + + align:start position:0% +right so the sum over all these Edge +distributions is twice the number of + + align:start position:0% +distributions is twice the number of + + + align:start position:0% +distributions is twice the number of +edges okay now I would say as a + + align:start position:0% +edges okay now I would say as a + + + align:start position:0% +edges okay now I would say as a +physicist you know working in biology my + + align:start position:0% +physicist you know working in biology my + + + align:start position:0% +physicist you know working in biology my +general attitude is that a factor of two + + align:start position:0% +general attitude is that a factor of two + + + align:start position:0% +general attitude is that a factor of two +here factor of two there doesn't really + + align:start position:0% +here factor of two there doesn't really + + + align:start position:0% +here factor of two there doesn't really +matter right um but this Factor two + + align:start position:0% +matter right um but this Factor two + + + align:start position:0% +matter right um but this Factor two +actually is relevant because it ends up + + align:start position:0% +actually is relevant because it ends up + + + align:start position:0% +actually is relevant because it ends up +determining the scaling over time right + + align:start position:0% +determining the scaling over time right + + + align:start position:0% +determining the scaling over time right +so um so this is you know you know not + + align:start position:0% +so um so this is you know you know not + + + align:start position:0% +so um so this is you know you know not +all factors of two are created equal and + + align:start position:0% +all factors of two are created equal and + + + align:start position:0% +all factors of two are created equal and +this this is one that is worth that is + + align:start position:0% +this this is one that is worth that is + + + align:start position:0% +this this is one that is worth that is +worth paying attention to okay all right + + align:start position:0% +worth paying attention to okay all right + + + align:start position:0% +worth paying attention to okay all right +does everybody understand why there's + + align:start position:0% +does everybody understand why there's + + + align:start position:0% +does everybody understand why there's +why this is two times the number of + + align:start position:0% +why this is two times the number of + + + align:start position:0% +why this is two times the number of +edges + + align:start position:0% + + + + align:start position:0% + +right right K1 is equal to 1 K2 is equal + + align:start position:0% +right right K1 is equal to 1 K2 is equal + + + align:start position:0% +right right K1 is equal to 1 K2 is equal +to 1 number of edges is equal to + + align:start position:0% + + + + align:start position:0% + +one yep okay so that means we're in an + + align:start position:0% +one yep okay so that means we're in an + + + align:start position:0% +one yep okay so that means we're in an +undirected network if you were in a + + align:start position:0% +undirected network if you were in a + + + align:start position:0% +undirected network if you were in a +directed Network then you would not have + + align:start position:0% +directed Network then you would not have + + + align:start position:0% +directed Network then you would not have +that fact yes so we are indeed in an + + align:start position:0% +that fact yes so we are indeed in an + + + align:start position:0% +that fact yes so we are indeed in an +undirected i' say in a directed Network + + align:start position:0% +undirected i' say in a directed Network + + + align:start position:0% +undirected i' say in a directed Network +you have to then be more careful about + + align:start position:0% +you have to then be more careful about + + + align:start position:0% +you have to then be more careful about +what you I mean you have to specify the + + align:start position:0% +what you I mean you have to specify the + + + align:start position:0% +what you I mean you have to specify the +K's in and K's out so actually already + + align:start position:0% +K's in and K's out so actually already + + + align:start position:0% +K's in and K's out so actually already +just by writing this we've already + + align:start position:0% +just by writing this we've already + + + align:start position:0% +just by writing this we've already +assumed it's undirected because we + + align:start position:0% +assumed it's undirected because we + + + align:start position:0% +assumed it's undirected because we +haven't specified what we mean by K + + align:start position:0% +haven't specified what we mean by K + + + align:start position:0% +haven't specified what we mean by K +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +um okay all right um we're here but you + + align:start position:0% +um okay all right um we're here but you + + + align:start position:0% +um okay all right um we're here but you +know very we already know how how many + + align:start position:0% +know very we already know how how many + + + align:start position:0% +know very we already know how how many +edges there are as a function of time + + align:start position:0% +edges there are as a function of time + + + align:start position:0% +edges there are as a function of time +right this is just equal to M * T all + + align:start position:0% +right this is just equal to M * T all + + + align:start position:0% +right this is just equal to M * T all +right so we get something that's very + + align:start position:0% +right so we get something that's very + + + align:start position:0% +right so we get something that's very +convenient Ki / 2 + + align:start position:0% + + + + align:start position:0% + +T right from here we can uh you know we + + align:start position:0% +T right from here we can uh you know we + + + align:start position:0% +T right from here we can uh you know we +can solve the differential equation + + align:start position:0% +can solve the differential equation + + + align:start position:0% +can solve the differential equation +right so this is what we were what we + + align:start position:0% +right so this is what we were what we + + + align:start position:0% +right so this is what we were what we +wanted to show right so uh the fact that + + align:start position:0% +wanted to show right so uh the fact that + + + align:start position:0% +wanted to show right so uh the fact that +we're doing partials doesn't really + + align:start position:0% +we're doing partials doesn't really + + + align:start position:0% +we're doing partials doesn't really +matter because it's just time here right + + align:start position:0% +matter because it's just time here right + + + align:start position:0% +matter because it's just time here right +so it's really so we have d k i over k i + + align:start position:0% +so it's really so we have d k i over k i + + + align:start position:0% +so it's really so we have d k i over k i +is equal to DT over + + align:start position:0% + + + + align:start position:0% + +2T right so this two really again is + + align:start position:0% +2T right so this two really again is + + + align:start position:0% +2T right so this two really again is +going to make a difference because you + + align:start position:0% +going to make a difference because you + + + align:start position:0% +going to make a difference because you +know when we're when we go and we + + align:start position:0% +know when we're when we go and we + + + align:start position:0% +know when we're when we go and we +integrate we get the logs and so forth + + align:start position:0% +integrate we get the logs and so forth + + + align:start position:0% +integrate we get the logs and so forth +right and so we get that Ki as a + + align:start position:0% +right and so we get that Ki as a + + + align:start position:0% +right and so we get that Ki as a +function time is going to grow with time + + align:start position:0% +function time is going to grow with time + + + align:start position:0% +function time is going to grow with time +with some constant C proportionality to + + align:start position:0% +with some constant C proportionality to + + + align:start position:0% +with some constant C proportionality to +the square root of + + align:start position:0% +the square root of + + + align:start position:0% +the square root of +time right so if we didn't have the half + + align:start position:0% +time right so if we didn't have the half + + + align:start position:0% +time right so if we didn't have the half +it would just be linear with time + + align:start position:0% + + + + align:start position:0% + +now uh how how do we know what c in + + align:start position:0% +now uh how how do we know what c in + + + align:start position:0% +now uh how how do we know what c in +general how how do we get constants of + + align:start position:0% +general how how do we get constants of + + + align:start position:0% +general how how do we get constants of +integration in + + align:start position:0% +integration in + + + align:start position:0% +integration in +life yeah boundary conditions in this + + align:start position:0% +life yeah boundary conditions in this + + + align:start position:0% +life yeah boundary conditions in this +case the initial condition what is it + + align:start position:0% +case the initial condition what is it + + + align:start position:0% +case the initial condition what is it +that we + + align:start position:0% + + + + align:start position:0% + +know right so what we know is that Ki so + + align:start position:0% +know right so what we know is that Ki so + + + align:start position:0% +know right so what we know is that Ki so +this this I node when it's added at time + + align:start position:0% +this this I node when it's added at time + + + align:start position:0% +this this I node when it's added at time +TI should be equal to what + + align:start position:0% + + + + align:start position:0% + +M yeah it's equal to M so when it's + + align:start position:0% +M yeah it's equal to M so when it's + + + align:start position:0% +M yeah it's equal to M so when it's +first added at sometime TI its number of + + align:start position:0% +first added at sometime TI its number of + + + align:start position:0% +first added at sometime TI its number of +edges is equal to M because that's + + align:start position:0% +edges is equal to M because that's + + + align:start position:0% +edges is equal to M because that's +that's what we've assumed is that we add + + align:start position:0% +that's what we've assumed is that we add + + + align:start position:0% +that's what we've assumed is that we add +we add a node we connect it randomly to + + align:start position:0% +we add a node we connect it randomly to + + + align:start position:0% +we add a node we connect it randomly to +M other things so it it has M edges + + align:start position:0% +M other things so it it has M edges + + + align:start position:0% +M other things so it it has M edges +initially right so from this K of T this + + align:start position:0% +initially right so from this K of T this + + + align:start position:0% +initially right so from this K of T this +is then equal to M * the sare < TK of T + + align:start position:0% +is then equal to M * the sare < TK of T + + + align:start position:0% +is then equal to M * the sare < TK of T +/ T initial right where TI is the time + + align:start position:0% +/ T initial right where TI is the time + + + align:start position:0% +/ T initial right where TI is the time +that the I node was added to the network + + align:start position:0% +that the I node was added to the network + + + align:start position:0% +that the I node was added to the network +okay are there any questions about how + + align:start position:0% +okay are there any questions about how + + + align:start position:0% +okay are there any questions about how +we got + + align:start position:0% + + + + align:start position:0% + +there all right um so I think that this + + align:start position:0% +there all right um so I think that this + + + align:start position:0% +there all right um so I think that this +is relatively straightforward I think + + align:start position:0% +is relatively straightforward I think + + + align:start position:0% +is relatively straightforward I think +the part that gets confusing are is the + + align:start position:0% +the part that gets confusing are is the + + + align:start position:0% +the part that gets confusing are is the +this this later part about the + + align:start position:0% +this this later part about the + + + align:start position:0% +this this later part about the +probabilities and kind of keeping + + align:start position:0% +probabilities and kind of keeping + + + align:start position:0% +probabilities and kind of keeping +keeping everything straight right so the + + align:start position:0% +keeping everything straight right so the + + + align:start position:0% +keeping everything straight right so the +the what what barasi did next is he said + + align:start position:0% +the what what barasi did next is he said + + + align:start position:0% +the what what barasi did next is he said +all right well what we're going to do is + + align:start position:0% +all right well what we're going to do is + + + align:start position:0% +all right well what we're going to do is +we're going to talk about the + + align:start position:0% +we're going to talk about the + + + align:start position:0% +we're going to talk about the +probability P right right now this is an + + align:start position:0% +probability P right right now this is an + + + align:start position:0% +probability P right right now this is an +actual honest to goodness + + align:start position:0% +actual honest to goodness + + + align:start position:0% +actual honest to goodness +probability okay the big p is actually a + + align:start position:0% +probability okay the big p is actually a + + + align:start position:0% +probability okay the big p is actually a +probability and that's as compared to a + + align:start position:0% +probability and that's as compared to a + + + align:start position:0% +probability and that's as compared to a +probability + + align:start position:0% +probability + + + align:start position:0% +probability +distribution Little + + align:start position:0% +distribution Little + + + align:start position:0% +distribution Little +P and I'll put in a little curly here + + align:start position:0% +P and I'll put in a little curly here + + + align:start position:0% +P and I'll put in a little curly here +thing so that's a little p all right + + align:start position:0% +thing so that's a little p all right + + + align:start position:0% +thing so that's a little p all right +this is saying if you want to get an + + align:start position:0% +this is saying if you want to get an + + + align:start position:0% +this is saying if you want to get an +actual probability here then you have to + + align:start position:0% +actual probability here then you have to + + + align:start position:0% +actual probability here then you have to +multiply that probability distribution + + align:start position:0% +multiply that probability distribution + + + align:start position:0% +multiply that probability distribution +times some range Delta K right so if you + + align:start position:0% +times some range Delta K right so if you + + + align:start position:0% +times some range Delta K right so if you +want to know that the probability that + + align:start position:0% +want to know that the probability that + + + align:start position:0% +want to know that the probability that +some node has between some number and + + align:start position:0% +some node has between some number and + + + align:start position:0% +some node has between some number and +some number of of edges then you + + align:start position:0% +some number of of edges then you + + + align:start position:0% +some number of of edges then you +multiply it by that that + + align:start position:0% +multiply it by that that + + + align:start position:0% +multiply it by that that +range + + align:start position:0% + + + + align:start position:0% + +right probability distribution this is + + align:start position:0% +right probability distribution this is + + + align:start position:0% +right probability distribution this is +an actual probability right and and as + + align:start position:0% +an actual probability right and and as + + + align:start position:0% +an actual probability right and and as +befits an actual probability we're going + + align:start position:0% +befits an actual probability we're going + + + align:start position:0% +befits an actual probability we're going +to say okay the probability that the I + + align:start position:0% +to say okay the probability that the I + + + align:start position:0% +to say okay the probability that the I +the I node has K edges that are less + + align:start position:0% +the I node has K edges that are less + + + align:start position:0% +the I node has K edges that are less +than some value + + align:start position:0% +than some value + + + align:start position:0% +than some value +K and remember this thing is actually a + + align:start position:0% +K and remember this thing is actually a + + + align:start position:0% +K and remember this thing is actually a +function of time + + align:start position:0% + + + + align:start position:0% + +okay but we have an expression for KI as + + align:start position:0% +okay but we have an expression for KI as + + + align:start position:0% +okay but we have an expression for KI as +function of time it's equal to + + align:start position:0% +function of time it's equal to + + + align:start position:0% +function of time it's equal to +this okay so we can kind of we can solve + + align:start position:0% +this okay so we can kind of we can solve + + + align:start position:0% +this okay so we can kind of we can solve +we can show that this probability is + + align:start position:0% +we can show that this probability is + + + align:start position:0% +we can show that this probability is +also the same as this other probability + + align:start position:0% +also the same as this other probability + + + align:start position:0% +also the same as this other probability +that that the node the I node was added + + align:start position:0% +that that the node the I node was added + + + align:start position:0% +that that the node the I node was added +after sometime T that is can be written + + align:start position:0% +after sometime T that is can be written + + + align:start position:0% +after sometime T that is can be written +as + + align:start position:0% + + + + align:start position:0% + +this okay so this is saying the + + align:start position:0% +this okay so this is saying the + + + align:start position:0% +this okay so this is saying the +probability that some random say I node + + align:start position:0% +probability that some random say I node + + + align:start position:0% +probability that some random say I node +has fewer than K edges is the same as + + align:start position:0% +has fewer than K edges is the same as + + + align:start position:0% +has fewer than K edges is the same as +saying that the it's the probability + + align:start position:0% +saying that the it's the probability + + + align:start position:0% +saying that the it's the probability +that the I node was added after sometime + + align:start position:0% +that the I node was added after sometime + + + align:start position:0% +that the I node was added after sometime +T which is which is this + + align:start position:0% +T which is which is this + + + align:start position:0% +T which is which is this +thing okay because the number of edges + + align:start position:0% +thing okay because the number of edges + + + align:start position:0% +thing okay because the number of edges +will grow over time for each of each of + + align:start position:0% +will grow over time for each of each of + + + align:start position:0% +will grow over time for each of each of +these nodes + + align:start position:0% + + + + align:start position:0% + +okay do you guys do you understand the + + align:start position:0% +okay do you guys do you understand the + + + align:start position:0% +okay do you guys do you understand the +the kind of conceptual statement that + + align:start position:0% +the kind of conceptual statement that + + + align:start position:0% +the kind of conceptual statement that +was made there + + align:start position:0% + + + + align:start position:0% + +yes any any + + align:start position:0% + + + + align:start position:0% + +questions all right so the probability + + align:start position:0% +questions all right so the probability + + + align:start position:0% +questions all right so the probability +that this I node was added after this + + align:start position:0% +that this I node was added after this + + + align:start position:0% +that this I node was added after this +time is also of course one + + align:start position:0% +time is also of course one + + + align:start position:0% +time is also of course one +minus the probability that it was added + + align:start position:0% +minus the probability that it was added + + + align:start position:0% +minus the probability that it was added +before that time + + align:start position:0% + + + + align:start position:0% + +right right where whereas time Little T + + align:start position:0% +right right where whereas time Little T + + + align:start position:0% +right right where whereas time Little T +here this is at the time that you're + + align:start position:0% +here this is at the time that you're + + + align:start position:0% +here this is at the time that you're +actually looking right so this is saying + + align:start position:0% +actually looking right so this is saying + + + align:start position:0% +actually looking right so this is saying +oh well if Little T is 100 for example + + align:start position:0% +oh well if Little T is 100 for example + + + align:start position:0% +oh well if Little T is 100 for example +it's saying oh at at that time point + + align:start position:0% +it's saying oh at at that time point + + + align:start position:0% +it's saying oh at at that time point +after we've added 100 nodes right we + + align:start position:0% +after we've added 100 nodes right we + + + align:start position:0% +after we've added 100 nodes right we +want to say all right what's the + + align:start position:0% +want to say all right what's the + + + align:start position:0% +want to say all right what's the +probability that some random I node was + + align:start position:0% +probability that some random I node was + + + align:start position:0% +probability that some random I node was +added before this quantity and this is + + align:start position:0% +added before this quantity and this is + + + align:start position:0% +added before this quantity and this is +just again some other kind of time if + + align:start position:0% +just again some other kind of time if + + + align:start position:0% +just again some other kind of time if +you'd + + align:start position:0% +you'd + + + align:start position:0% +you'd +like + + align:start position:0% + + + + align:start position:0% + +okay okay and I think this is the part + + align:start position:0% +okay okay and I think this is the part + + + align:start position:0% +okay okay and I think this is the part +that is especially kind of weird all + + align:start position:0% +that is especially kind of weird all + + + align:start position:0% +that is especially kind of weird all +right so this is also equal to this + + align:start position:0% +right so this is also equal to this + + + align:start position:0% +right so this is also equal to this +thing + + align:start position:0% +thing + + + align:start position:0% +thing +um and I think you know reasonable + + align:start position:0% +um and I think you know reasonable + + + align:start position:0% +um and I think you know reasonable +people can argue about exactly what you + + align:start position:0% +people can argue about exactly what you + + + align:start position:0% +people can argue about exactly what you +should write here uh but we we let's + + align:start position:0% +should write here uh but we we let's + + + align:start position:0% +should write here uh but we we let's +figure out the basic argument first all + + align:start position:0% +figure out the basic argument first all + + + align:start position:0% +figure out the basic argument first all +right so there's this probability is + + align:start position:0% +right so there's this probability is + + + align:start position:0% +right so there's this probability is +equal to this thing okay so the the + + align:start position:0% +equal to this thing okay so the the + + + align:start position:0% +equal to this thing okay so the the +statement is really that at some time + + align:start position:0% +statement is really that at some time + + + align:start position:0% +statement is really that at some time +sometime + + align:start position:0% +sometime + + + align:start position:0% +sometime +T we have how many nodes we have we have + + align:start position:0% +T we have how many nodes we have we have + + + align:start position:0% +T we have how many nodes we have we have +M plus T nodes right so this is this is + + align:start position:0% +M plus T nodes right so this is this is + + + align:start position:0% +M plus T nodes right so this is this is +something + + align:start position:0% +something + + + align:start position:0% +something +here and of course there are edges going + + align:start position:0% +here and of course there are edges going + + + align:start position:0% +here and of course there are edges going +around doing things right and what we + + align:start position:0% +around doing things right and what we + + + align:start position:0% +around doing things right and what we +want to know is what's the probability + + align:start position:0% +want to know is what's the probability + + + align:start position:0% +want to know is what's the probability +if I grab one of them you know we're + + align:start position:0% +if I grab one of them you know we're + + + align:start position:0% +if I grab one of them you know we're +going to call that the I node okay so + + align:start position:0% +going to call that the I node okay so + + + align:start position:0% +going to call that the I node okay so +what's the probability if I grab one of + + align:start position:0% +what's the probability if I grab one of + + + align:start position:0% +what's the probability if I grab one of +them that it was added + + align:start position:0% +them that it was added + + + align:start position:0% +them that it was added +before + + align:start position:0% +before + + + align:start position:0% +before +sometime + + align:start position:0% +sometime + + + align:start position:0% +sometime +here okay and and it's useful to just + + align:start position:0% +here okay and and it's useful to just + + + align:start position:0% +here okay and and it's useful to just +imagine this as just being sometime T + + align:start position:0% +imagine this as just being sometime T + + + align:start position:0% +imagine this as just being sometime T +which + + align:start position:0% +which + + + align:start position:0% +which +will you know just just so that we don't + + align:start position:0% +will you know just just so that we don't + + + align:start position:0% +will you know just just so that we don't +get confused by + + align:start position:0% +get confused by + + + align:start position:0% +get confused by +all the symbols right then you say oh + + align:start position:0% +all the symbols right then you say oh + + + align:start position:0% +all the symbols right then you say oh +well that Pro that probability is really + + align:start position:0% +well that Pro that probability is really + + + align:start position:0% +well that Pro that probability is really +just the probability well how how many + + align:start position:0% +just the probability well how how many + + + align:start position:0% +just the probability well how how many +nodes were how many nodes total do we + + align:start position:0% +nodes were how many nodes total do we + + + align:start position:0% +nodes were how many nodes total do we +have we have M plus T how many nodes + + align:start position:0% +have we have M plus T how many nodes + + + align:start position:0% +have we have M plus T how many nodes +were there that were added before this + + align:start position:0% +were there that were added before this + + + align:start position:0% +were there that were added before this +time T well that's going to + + align:start position:0% +time T well that's going to + + + align:start position:0% +time T well that's going to +be T if you want you might want to say t + + align:start position:0% +be T if you want you might want to say t + + + align:start position:0% +be T if you want you might want to say t +plus M there's a question of whether you + + align:start position:0% +plus M there's a question of whether you + + + align:start position:0% +plus M there's a question of whether you +include those nodes that started there + + align:start position:0% +include those nodes that started there + + + align:start position:0% +include those nodes that started there +or not right um given the equations that + + align:start position:0% +or not right um given the equations that + + + align:start position:0% +or not right um given the equations that +barabasi wrote down he kind of assumes + + align:start position:0% +barabasi wrote down he kind of assumes + + + align:start position:0% +barabasi wrote down he kind of assumes +that we're only counting the that were + + align:start position:0% +that we're only counting the that were + + + align:start position:0% +that we're only counting the that were +added later right but you know so so I'd + + align:start position:0% +added later right but you know so so I'd + + + align:start position:0% +added later right but you know so so I'd +say if you want you could either add an + + align:start position:0% +say if you want you could either add an + + + align:start position:0% +say if you want you could either add an +mot up there or get rid of this m notot + + align:start position:0% +mot up there or get rid of this m notot + + + align:start position:0% +mot up there or get rid of this m notot +depending on what you like right but + + align:start position:0% +depending on what you like right but + + + align:start position:0% +depending on what you like right but +broadly there's this idea that we have + + align:start position:0% +broadly there's this idea that we have + + + align:start position:0% +broadly there's this idea that we have +this many nodes and this many of them + + align:start position:0% +this many nodes and this many of them + + + align:start position:0% +this many nodes and this many of them +were added before some time T and that's + + align:start position:0% +were added before some time T and that's + + + align:start position:0% +were added before some time T and that's +how we get this m^2 T over K squ which + + align:start position:0% +how we get this m^2 T over K squ which + + + align:start position:0% +how we get this m^2 T over K squ which +just that time T divided by the total + + align:start position:0% +just that time T divided by the total + + + align:start position:0% +just that time T divided by the total +number of of + + align:start position:0% +number of of + + + align:start position:0% +number of of +nodes + + align:start position:0% +nodes + + + align:start position:0% +nodes +okay and this whole discussion about + + align:start position:0% +okay and this whole discussion about + + + align:start position:0% +okay and this whole discussion about +whether you count the initial m not + + align:start position:0% +whether you count the initial m not + + + align:start position:0% +whether you count the initial m not +nodes or not it doesn't matter because + + align:start position:0% +nodes or not it doesn't matter because + + + align:start position:0% +nodes or not it doesn't matter because +we're going to be taking the limit as T + + align:start position:0% +we're going to be taking the limit as T + + + align:start position:0% +we're going to be taking the limit as T +goes to infinity and that all goes away + + align:start position:0% +goes to infinity and that all goes away + + + align:start position:0% +goes to infinity and that all goes away +right are there are there questions + + align:start position:0% +right are there are there questions + + + align:start position:0% +right are there are there questions +about this + + align:start position:0% +about this + + + align:start position:0% +about this +this there there are + + align:start position:0% +this there there are + + + align:start position:0% +this there there are +there's something kind of mind twisting + + align:start position:0% +there's something kind of mind twisting + + + align:start position:0% +there's something kind of mind twisting +about this argument even though we're + + align:start position:0% +about this argument even though we're + + + align:start position:0% +about this argument even though we're +really just + + align:start position:0% +really just + + + align:start position:0% +really just +picking Big T objects out of essentially + + align:start position:0% +picking Big T objects out of essentially + + + align:start position:0% +picking Big T objects out of essentially +Little T objects right but somehow that + + align:start position:0% +Little T objects right but somehow that + + + align:start position:0% +Little T objects right but somehow that +something funny goes on + + align:start position:0% +something funny goes on + + + align:start position:0% +something funny goes on +there all right + + align:start position:0% + + + + align:start position:0% + +any questions about about + + align:start position:0% +any questions about about + + + align:start position:0% +any questions about about +that + + align:start position:0% +that + + + align:start position:0% +that +um you just go through the argument one + + align:start position:0% +um you just go through the argument one + + + align:start position:0% +um you just go through the argument one +more time yeah yeah yeah sure sure um + + align:start position:0% +more time yeah yeah yeah sure sure um + + + align:start position:0% +more time yeah yeah yeah sure sure um +right so I think that what's confusing + + align:start position:0% +right so I think that what's confusing + + + align:start position:0% +right so I think that what's confusing +about it is is the fact that we're + + align:start position:0% +about it is is the fact that we're + + + align:start position:0% +about it is is the fact that we're +asking whether this whether the I node + + align:start position:0% +asking whether this whether the I node + + + align:start position:0% +asking whether this whether the I node +was added before some time T and and and + + align:start position:0% +was added before some time T and and and + + + align:start position:0% +was added before some time T and and and +this time T is equal to something that's + + align:start position:0% +this time T is equal to something that's + + + align:start position:0% +this time T is equal to something that's +funny based on this other what we've + + align:start position:0% +funny based on this other what we've + + + align:start position:0% +funny based on this other what we've +just done but I think it's useful to + + align:start position:0% +just done but I think it's useful to + + + align:start position:0% +just done but I think it's useful to +just ask if if at time Little + + align:start position:0% +just ask if if at time Little + + + align:start position:0% +just ask if if at time Little +T you have you know you look at you look + + align:start position:0% +T you have you know you look at you look + + + align:start position:0% +T you have you know you look at you look +at this network and I ask you all right + + align:start position:0% +at this network and I ask you all right + + + align:start position:0% +at this network and I ask you all right +well was it added before this time Big T + + align:start position:0% +well was it added before this time Big T + + + align:start position:0% +well was it added before this time Big T +I.E let's just for concreteness say you + + align:start position:0% +I.E let's just for concreteness say you + + + align:start position:0% +I.E let's just for concreteness say you +know m is equal to we start with 10 + + align:start position:0% +know m is equal to we start with 10 + + + align:start position:0% +know m is equal to we start with 10 +nodes and we say okay at time t equal to + + align:start position:0% +nodes and we say okay at time t equal to + + + align:start position:0% +nodes and we say okay at time t equal to +100 I want I ask you what's the + + align:start position:0% +100 I want I ask you what's the + + + align:start position:0% +100 I want I ask you what's the +probability that I grab if I grab a + + align:start position:0% +probability that I grab if I grab a + + + align:start position:0% +probability that I grab if I grab a +random node what's the probability it + + align:start position:0% +random node what's the probability it + + + align:start position:0% +random node what's the probability it +was added before some time Big T equal + + align:start position:0% +was added before some time Big T equal + + + align:start position:0% +was added before some time Big T equal +to + + align:start position:0% + + + + align:start position:0% + +10 okay well you would say um you know + + align:start position:0% +10 okay well you would say um you know + + + align:start position:0% +10 okay well you would say um you know +very roughly actually you we can say + + align:start position:0% +very roughly actually you we can say + + + align:start position:0% +very roughly actually you we can say +let's let's actually we can even just if + + align:start position:0% +let's let's actually we can even just if + + + align:start position:0% +let's let's actually we can even just if +we'd like say we're not going to count + + align:start position:0% +we'd like say we're not going to count + + + align:start position:0% +we'd like say we're not going to count +we're not going to we're not going to + + align:start position:0% +we're not going to we're not going to + + + align:start position:0% +we're not going to we're not going to +count those m not initial nodes so we're + + align:start position:0% +count those m not initial nodes so we're + + + align:start position:0% +count those m not initial nodes so we're +just going to be looking at nodes we + + align:start position:0% +just going to be looking at nodes we + + + align:start position:0% +just going to be looking at nodes we +added later if you'd like right and then + + align:start position:0% +added later if you'd like right and then + + + align:start position:0% +added later if you'd like right and then +then you would say all right well at + + align:start position:0% +then you would say all right well at + + + align:start position:0% +then you would say all right well at +time T 100 we've added 100 nodes right + + align:start position:0% +time T 100 we've added 100 nodes right + + + align:start position:0% +time T 100 we've added 100 nodes right +and I'm asking you what's the if I grab + + align:start position:0% +and I'm asking you what's the if I grab + + + align:start position:0% +and I'm asking you what's the if I grab +one of the noes what's the probability + + align:start position:0% +one of the noes what's the probability + + + align:start position:0% +one of the noes what's the probability +that I that the node I grab was added in + + align:start position:0% +that I that the node I grab was added in + + + align:start position:0% +that I that the node I grab was added in +the first 10 time steps right well you + + align:start position:0% +the first 10 time steps right well you + + + align:start position:0% +the first 10 time steps right well you +would say it's going to be 10% right + + align:start position:0% +would say it's going to be 10% right + + + align:start position:0% +would say it's going to be 10% right +because there were 10 nodes that were + + align:start position:0% +because there were 10 nodes that were + + + align:start position:0% +because there were 10 nodes that were +added Before Time Big T and we added 100 + + align:start position:0% +added Before Time Big T and we added 100 + + + align:start position:0% +added Before Time Big T and we added 100 +so it's really just this divided by this + + align:start position:0% +so it's really just this divided by this + + + align:start position:0% +so it's really just this divided by this +and you know with the question of + + align:start position:0% +and you know with the question of + + + align:start position:0% +and you know with the question of +whether you want to include M knots or + + align:start position:0% +whether you want to include M knots or + + + align:start position:0% +whether you want to include M knots or +not right so I think that that argument + + align:start position:0% +not right so I think that that argument + + + align:start position:0% +not right so I think that that argument +is surprisingly straightforward but then + + align:start position:0% +is surprisingly straightforward but then + + + align:start position:0% +is surprisingly straightforward but then +somehow what gets really confusing is + + align:start position:0% +somehow what gets really confusing is + + + align:start position:0% +somehow what gets really confusing is +that you know the time T we're referring + + align:start position:0% +that you know the time T we're referring + + + align:start position:0% +that you know the time T we're referring +to it it it's depending on the the K's + + align:start position:0% +to it it it's depending on the the K's + + + align:start position:0% +to it it it's depending on the the K's +and the t's and so forth right but + + align:start position:0% +and the t's and so forth right but + + + align:start position:0% +and the t's and so forth right but +that's that's a way of keeping track of + + align:start position:0% +that's that's a way of keeping track of + + + align:start position:0% +that's that's a way of keeping track of +how how everything is scaling as a + + align:start position:0% +how how everything is scaling as a + + + align:start position:0% +how how everything is scaling as a +function of time right but if you just + + align:start position:0% +function of time right but if you just + + + align:start position:0% +function of time right but if you just +if you boil the argument down to this + + align:start position:0% +if you boil the argument down to this + + + align:start position:0% +if you boil the argument down to this +then + + align:start position:0% +then + + + align:start position:0% +then +it it makes sense but then of course + + align:start position:0% +it it makes sense but then of course + + + align:start position:0% +it it makes sense but then of course +then you look back at this and you get + + align:start position:0% +then you look back at this and you get + + + align:start position:0% +then you look back at this and you get +confused again right um which is um how + + align:start position:0% +confused again right um which is um how + + + align:start position:0% +confused again right um which is um how +I feel every year when I prepare this + + align:start position:0% +I feel every year when I prepare this + + + align:start position:0% +I feel every year when I prepare this +lecture but but I think it but it's all + + align:start position:0% +lecture but but I think it but it's all + + + align:start position:0% +lecture but but I think it but it's all +I think it's all it all does make sense + + align:start position:0% +I think it's all it all does make sense + + + align:start position:0% +I think it's all it all does make sense +if you + + align:start position:0% +if you + + + align:start position:0% +if you +um okay + + align:start position:0% +um okay + + + align:start position:0% +um okay +did any questions about this argument or + + align:start position:0% +did any questions about this argument or + + + align:start position:0% +did any questions about this argument or +that argument or any part of it um + + align:start position:0% + + + + align:start position:0% + +yes yes all right + + align:start position:0% +yes yes all right + + + align:start position:0% +yes yes all right +so right so okay so this is TI this is + + align:start position:0% +so right so okay so this is TI this is + + + align:start position:0% +so right so okay so this is TI this is +just saying that if I pick some random + + align:start position:0% +just saying that if I pick some random + + + align:start position:0% +just saying that if I pick some random +node we're we're calling it The I node + + align:start position:0% +node we're we're calling it The I node + + + align:start position:0% +node we're we're calling it The I node +I'm asking what's the probability that + + align:start position:0% +I'm asking what's the probability that + + + align:start position:0% +I'm asking what's the probability that +that the time it was added was before + + align:start position:0% +that the time it was added was before + + + align:start position:0% +that the time it was added was before +something right so this is just this is + + align:start position:0% +something right so this is just this is + + + align:start position:0% +something right so this is just this is +is not one of the variables and you'll + + align:start position:0% +is not one of the variables and you'll + + + align:start position:0% +is not one of the variables and you'll +see the ti doesn't appear down here + + align:start position:0% +see the ti doesn't appear down here + + + align:start position:0% +see the ti doesn't appear down here +because this is just saying because I'm + + align:start position:0% +because this is just saying because I'm + + + align:start position:0% +because this is just saying because I'm +just I'm I'm asking you if I grab some + + align:start position:0% +just I'm I'm asking you if I grab some + + + align:start position:0% +just I'm I'm asking you if I grab some +random node the I node I'm asking you + + align:start position:0% +random node the I node I'm asking you + + + align:start position:0% +random node the I node I'm asking you +what's the probability that it was added + + align:start position:0% +what's the probability that it was added + + + align:start position:0% +what's the probability that it was added +before some other time which is which is + + align:start position:0% +before some other time which is which is + + + align:start position:0% +before some other time which is which is +all this right so and what you can see + + align:start position:0% +all this right so and what you can see + + + align:start position:0% +all this right so and what you can see +is that it it's a function of of you + + align:start position:0% +is that it it's a function of of you + + + align:start position:0% +is that it it's a function of of you +know the time that we look right because + + align:start position:0% +know the time that we look right because + + + align:start position:0% +know the time that we look right because +if if I go to longer + + align:start position:0% +if if I go to longer + + + align:start position:0% +if if I go to longer +times you know then indeed this + + align:start position:0% +times you know then indeed this + + + align:start position:0% +times you know then indeed this +probability should have go what should + + align:start position:0% +probability should have go what should + + + align:start position:0% +probability should have go what should +it do + + align:start position:0% + + + + align:start position:0% + +okay but it depends on KS as well + + align:start position:0% +okay but it depends on KS as well + + + align:start position:0% +okay but it depends on KS as well +right what do I want to + + align:start position:0% + + + + align:start position:0% + +say all right because ultimately what + + align:start position:0% +say all right because ultimately what + + + align:start position:0% +say all right because ultimately what +what we what we see here is that as as + + align:start position:0% +what we what we see here is that as as + + + align:start position:0% +what we what we see here is that as as +as time goes to Infinity so as after a + + align:start position:0% +as time goes to Infinity so as after a + + + align:start position:0% +as time goes to Infinity so as after a +long time then we reach this stationary + + align:start position:0% +long time then we reach this stationary + + + align:start position:0% +long time then we reach this stationary +distribution where uh the the base + + align:start position:0% +distribution where uh the the base + + + align:start position:0% +distribution where uh the the base +structure of the network is not changing + + align:start position:0% +structure of the network is not changing + + + align:start position:0% +structure of the network is not changing +anymore right and that's because the + + align:start position:0% +anymore right and that's because the + + + align:start position:0% +anymore right and that's because the +there's a t in both the numerator and + + align:start position:0% +there's a t in both the numerator and + + + align:start position:0% +there's a t in both the numerator and +the denominator so then the only thing + + align:start position:0% +the denominator so then the only thing + + + align:start position:0% +the denominator so then the only thing +that kind of is left is this Behavior as + + align:start position:0% +that kind of is left is this Behavior as + + + align:start position:0% +that kind of is left is this Behavior as +a function of K right so this is and + + align:start position:0% +a function of K right so this is and + + + align:start position:0% +a function of K right so this is and +this is really saying that you know the + + align:start position:0% +this is really saying that you know the + + + align:start position:0% +this is really saying that you know the +probability + + align:start position:0% +probability + + + align:start position:0% +probability +that some node was added before some + + align:start position:0% +that some node was added before some + + + align:start position:0% +that some node was added before some +time is is kind of the same as saying + + align:start position:0% +time is is kind of the same as saying + + + align:start position:0% +time is is kind of the same as saying +that well that you have a lot of edges + + align:start position:0% +that well that you have a lot of edges + + + align:start position:0% +that well that you have a lot of edges +and and that's how we got here to begin + + align:start position:0% +and and that's how we got here to begin + + + align:start position:0% +and and that's how we got here to begin +with right because the the nodes that + + align:start position:0% +with right because the the nodes that + + + align:start position:0% +with right because the the nodes that +were added early end up with a lot of + + align:start position:0% +were added early end up with a lot of + + + align:start position:0% +were added early end up with a lot of +edges this is the so-called Rich get + + align:start position:0% +edges this is the so-called Rich get + + + align:start position:0% +edges this is the so-called Rich get +richer phenom phenomenon all right so if + + align:start position:0% +richer phenom phenomenon all right so if + + + align:start position:0% +richer phenom phenomenon all right so if +you're sitting on a manuscript and + + align:start position:0% +you're sitting on a manuscript and + + + align:start position:0% +you're sitting on a manuscript and +you're not submitting it for publication + + align:start position:0% +you're not submitting it for publication + + + align:start position:0% +you're not submitting it for publication +you should kind of get on it because you + + align:start position:0% +you should kind of get on it because you + + + align:start position:0% +you should kind of get on it because you +know the earlier that it's published the + + align:start position:0% +know the earlier that it's published the + + + align:start position:0% +know the earlier that it's published the +more citations it's going to get okay + + align:start position:0% +more citations it's going to get okay + + + align:start position:0% +more citations it's going to get okay +right but this is saying that right the + + align:start position:0% +right but this is saying that right the + + + align:start position:0% +right but this is saying that right the +probability that some random node has a + + align:start position:0% +probability that some random node has a + + + align:start position:0% +probability that some random node has a +small number of + + align:start position:0% +small number of + + + align:start position:0% +small number of +edges is the same as that the + + align:start position:0% +edges is the same as that the + + + align:start position:0% +edges is the same as that the +probability that the node was added + + align:start position:0% +probability that the node was added + + + align:start position:0% +probability that the node was added +late right and that makes sense because + + align:start position:0% +late right and that makes sense because + + + align:start position:0% +late right and that makes sense because +if it's added late doesn't have very + + align:start position:0% +if it's added late doesn't have very + + + align:start position:0% +if it's added late doesn't have very +many edges hasn't had time to grow right + + align:start position:0% +many edges hasn't had time to grow right + + + align:start position:0% +many edges hasn't had time to grow right +and then you know just you know from th + + align:start position:0% +and then you know just you know from th + + + align:start position:0% +and then you know just you know from th +those uh those calculations you can get + + align:start position:0% +those uh those calculations you can get + + + align:start position:0% +those uh those calculations you can get +it at this degree + + align:start position:0% + + + + align:start position:0% + +distribution okay yes in this analytical + + align:start position:0% +distribution okay yes in this analytical + + + align:start position:0% +distribution okay yes in this analytical +Anis assuming that the links could + + align:start position:0% + + + + align:start position:0% + +Beal non yeah okay right + + align:start position:0% +Beal non yeah okay right + + + align:start position:0% +Beal non yeah okay right +so yes so we're we're taking in + + align:start position:0% +so yes so we're we're taking in + + + align:start position:0% +so yes so we're we're taking in +principle it's a discret problem and + + align:start position:0% +principle it's a discret problem and + + + align:start position:0% +principle it's a discret problem and +converting it into into a differential + + align:start position:0% +converting it into into a differential + + + align:start position:0% +converting it into into a differential +equation right um you know and it's an + + align:start position:0% +equation right um you know and it's an + + + align:start position:0% +equation right um you know and it's an +interesting question of of I don't know + + align:start position:0% +interesting question of of I don't know + + + align:start position:0% +interesting question of of I don't know +how big of an error this ends up making + + align:start position:0% +how big of an error this ends up making + + + align:start position:0% +how big of an error this ends up making +right U and and of + + align:start position:0% +right U and and of + + + align:start position:0% +right U and and of +course this expression doesn't actually + + align:start position:0% +course this expression doesn't actually + + + align:start position:0% +course this expression doesn't actually +end up being integ you know having + + align:start position:0% +end up being integ you know having + + + align:start position:0% +end up being integ you know having +integers right but this is a this is a + + align:start position:0% +integers right but this is a this is a + + + align:start position:0% +integers right but this is a this is a +way of making it so that the errors + + align:start position:0% +way of making it so that the errors + + + align:start position:0% +way of making it so that the errors +don't grow or so right um you know so I + + align:start position:0% +don't grow or so right um you know so I + + + align:start position:0% +don't grow or so right um you know so I +think that it it you know it basically + + align:start position:0% +think that it it you know it basically + + + align:start position:0% +think that it it you know it basically +works I think you if you'd like you + + align:start position:0% +works I think you if you'd like you + + + align:start position:0% +works I think you if you'd like you +could you know you can sit down actually + + align:start position:0% +could you know you can sit down actually + + + align:start position:0% +could you know you can sit down actually +do the simulation with all the discrete + + align:start position:0% +do the simulation with all the discrete + + + align:start position:0% +do the simulation with all the discrete +I think that it's actually going to be + + align:start position:0% +I think that it's actually going to be + + + align:start position:0% +I think that it's actually going to be +the stochastic dynamics that end up + + align:start position:0% +the stochastic dynamics that end up + + + align:start position:0% +the stochastic dynamics that end up +being more relevant than the the integer + + align:start position:0% +being more relevant than the the integer + + + align:start position:0% +being more relevant than the the integer +kind of issue um but I I haven't + + align:start position:0% +kind of issue um but I I haven't + + + align:start position:0% +kind of issue um but I I haven't +actually looked into that + + align:start position:0% + + + + align:start position:0% + +though okay um all right any other + + align:start position:0% +though okay um all right any other + + + align:start position:0% +though okay um all right any other +questions about about that so far + + align:start position:0% + + + + align:start position:0% + +yes right so there's no loss of edges no + + align:start position:0% +yes right so there's no loss of edges no + + + align:start position:0% +yes right so there's no loss of edges no +loss of nodes strictly verboten + + align:start position:0% +loss of nodes strictly verboten + + + align:start position:0% +loss of nodes strictly verboten +[Applause] + + align:start position:0% + + + + align:start position:0% + +I spent a lot of time trying to plan an + + align:start position:0% +I spent a lot of time trying to plan an + + + align:start position:0% +I spent a lot of time trying to plan an +upcoming trip to Germany last night so + + align:start position:0% +upcoming trip to Germany last night so + + + align:start position:0% +upcoming trip to Germany last night so +I'm I'm German is on my + + align:start position:0% +I'm I'm German is on my + + + align:start position:0% +I'm I'm German is on my +mind + + align:start position:0% +mind + + + align:start position:0% +mind +[Applause] + + align:start position:0% + + + + align:start position:0% + +um all right so are are We Done Yet + + align:start position:0% +um all right so are are We Done Yet + + + align:start position:0% +um all right so are are We Done Yet +incidentally uh nearly right because we + + align:start position:0% +incidentally uh nearly right because we + + + align:start position:0% +incidentally uh nearly right because we +have um now this but but what we really + + align:start position:0% +have um now this but but what we really + + + align:start position:0% +have um now this but but what we really +wanted is the is the degree distribution + + align:start position:0% +wanted is the is the degree distribution + + + align:start position:0% +wanted is the is the degree distribution +not this probability + + align:start position:0% +not this probability + + + align:start position:0% +not this probability +right so we have to take a derivative + + align:start position:0% +right so we have to take a derivative + + + align:start position:0% +right so we have to take a derivative +still right but as as T goes to + + align:start position:0% + + + + align:start position:0% + +Infinity regardless of how you treat the + + align:start position:0% +Infinity regardless of how you treat the + + + align:start position:0% +Infinity regardless of how you treat the +M knots um oh actually well we maybe + + align:start position:0% +M knots um oh actually well we maybe + + + align:start position:0% +M knots um oh actually well we maybe +we'll sorry maybe we'll take take the + + align:start position:0% +we'll sorry maybe we'll take take the + + + align:start position:0% +we'll sorry maybe we'll take take the +derivative first okay so the this + + align:start position:0% +derivative first okay so the this + + + align:start position:0% +derivative first okay so the this +probability + + align:start position:0% +probability + + + align:start position:0% +probability +density right is going to be uh the + + align:start position:0% +density right is going to be uh the + + + align:start position:0% +density right is going to be uh the +derivative with respect to K of the + + align:start position:0% +derivative with respect to K of the + + + align:start position:0% +derivative with respect to K of the +actual + + align:start position:0% +actual + + + align:start position:0% +actual +probability here + + align:start position:0% + + + + align:start position:0% + +all right so we take a derivative this + + align:start position:0% +all right so we take a derivative this + + + align:start position:0% +all right so we take a derivative this +one derivative nothing happens K2 it's + + align:start position:0% +one derivative nothing happens K2 it's + + + align:start position:0% +one derivative nothing happens K2 it's +going to turn into a k a k cubed right + + align:start position:0% +going to turn into a k a k cubed right + + + align:start position:0% +going to turn into a k a k cubed right +so we get 2 m^ 2 T over K + + align:start position:0% +so we get 2 m^ 2 T over K + + + align:start position:0% +so we get 2 m^ 2 T over K +cubed we still have the m t plus + + align:start position:0% +cubed we still have the m t plus + + + align:start position:0% +cubed we still have the m t plus +M all right but when we uh when we let T + + align:start position:0% +M all right but when we uh when we let T + + + align:start position:0% +M all right but when we uh when we let T +go to Infinity so after this thing is + + align:start position:0% +go to Infinity so after this thing is + + + align:start position:0% +go to Infinity so after this thing is +reached stationary distribution + + align:start position:0% + + + + align:start position:0% + +then we end up just getting 2 m^2 over K + + align:start position:0% +then we end up just getting 2 m^2 over K + + + align:start position:0% +then we end up just getting 2 m^2 over K +Cub + + align:start position:0% +Cub + + + align:start position:0% +Cub +right I just want to be clear this is to + + align:start position:0% +right I just want to be clear this is to + + + align:start position:0% +right I just want to be clear this is to +the K right the key feature here is that + + align:start position:0% +the K right the key feature here is that + + + align:start position:0% +the K right the key feature here is that +um the probability distribution goes as + + align:start position:0% +um the probability distribution goes as + + + align:start position:0% +um the probability distribution goes as +um 1 over K + + align:start position:0% + + + + align:start position:0% + +cubed um what is interesting is that you + + align:start position:0% +cubed um what is interesting is that you + + + align:start position:0% +cubed um what is interesting is that you +know when I first read the paper I + + align:start position:0% +know when I first read the paper I + + + align:start position:0% +know when I first read the paper I +actually thought + + align:start position:0% +actually thought + + + align:start position:0% +actually thought +that this exponent here would be a + + align:start position:0% +that this exponent here would be a + + + align:start position:0% +that this exponent here would be a +function of the linearity of the + + align:start position:0% +function of the linearity of the + + + align:start position:0% +function of the linearity of the +preferential attachment so I actually I + + align:start position:0% +preferential attachment so I actually I + + + align:start position:0% +preferential attachment so I actually I +you know and of course they say that + + align:start position:0% +you know and of course they say that + + + align:start position:0% +you know and of course they say that +it's not true right but when I was + + align:start position:0% +it's not true right but when I was + + + align:start position:0% +it's not true right but when I was +halfway through the paper I thought oh + + align:start position:0% +halfway through the paper I thought oh + + + align:start position:0% +halfway through the paper I thought oh +well if you just let this go as some + + align:start position:0% +well if you just let this go as some + + + align:start position:0% +well if you just let this go as some +power to the beta or so then you would + + align:start position:0% +power to the beta or so then you would + + + align:start position:0% +power to the beta or so then you would +maybe get something like oh this was you + + align:start position:0% +maybe get something like oh this was you + + + align:start position:0% +maybe get something like oh this was you +know 2 plus beta you know I thought + + align:start position:0% +know 2 plus beta you know I thought + + + align:start position:0% +know 2 plus beta you know I thought +something like that uh but apparently + + align:start position:0% +something like that uh but apparently + + + align:start position:0% +something like that uh but apparently +it's not true right that uh if if you uh + + align:start position:0% +it's not true right that uh if if you uh + + + align:start position:0% +it's not true right that uh if if you uh +if you do not have linear attachment + + align:start position:0% +if you do not have linear attachment + + + align:start position:0% +if you do not have linear attachment +here then you just don't get power law + + align:start position:0% +here then you just don't get power law + + + align:start position:0% +here then you just don't get power law +distributions right they suggest other + + align:start position:0% +distributions right they suggest other + + + align:start position:0% +distributions right they suggest other +ways that you could maybe get different + + align:start position:0% +ways that you could maybe get different + + + align:start position:0% +ways that you could maybe get different +exponents which is very relevant given + + align:start position:0% +exponents which is very relevant given + + + align:start position:0% +exponents which is very relevant given +the fact that different real networks + + align:start position:0% +the fact that different real networks + + + align:start position:0% +the fact that different real networks +indeed have different exponents right um + + align:start position:0% +indeed have different exponents right um + + + align:start position:0% +indeed have different exponents right um +but I'd say that their their proferred + + align:start position:0% +but I'd say that their their proferred + + + align:start position:0% +but I'd say that their their proferred +explanation which is to include directed + + align:start position:0% +explanation which is to include directed + + + align:start position:0% +explanation which is to include directed +edges feels uh unsatisfying because not + + align:start position:0% +edges feels uh unsatisfying because not + + + align:start position:0% +edges feels uh unsatisfying because not +all networks are directed right uh and + + align:start position:0% +all networks are directed right uh and + + + align:start position:0% +all networks are directed right uh and +this network here is not directed and + + align:start position:0% +this network here is not directed and + + + align:start position:0% +this network here is not directed and +has different has an exponents closer to + + align:start position:0% +has different has an exponents closer to + + + align:start position:0% +has different has an exponents closer to +two right so you would you really want + + align:start position:0% +two right so you would you really want + + + align:start position:0% +two right so you would you really want +to have other other mechanisms but you + + align:start position:0% +to have other other mechanisms but you + + + align:start position:0% +to have other other mechanisms but you +know this as we've mentioned is it's a + + align:start position:0% +know this as we've mentioned is it's a + + + align:start position:0% +know this as we've mentioned is it's a +thriving field and uh and people have + + align:start position:0% +thriving field and uh and people have + + + align:start position:0% +thriving field and uh and people have +explored many different aspects of this + + align:start position:0% +explored many different aspects of this + + + align:start position:0% +explored many different aspects of this +problem + + align:start position:0% + + + + align:start position:0% + +okay um are there any any other + + align:start position:0% +okay um are there any any other + + + align:start position:0% +okay um are there any any other +questions about this derivation how we + + align:start position:0% +questions about this derivation how we + + + align:start position:0% +questions about this derivation how we +got there how convincing we maybe you + + align:start position:0% +got there how convincing we maybe you + + + align:start position:0% +got there how convincing we maybe you +think it should be or not be + + align:start position:0% + + + + align:start position:0% + +okay so I want I want us to to spend the + + align:start position:0% +okay so I want I want us to to spend the + + + align:start position:0% +okay so I want I want us to to spend the +the last five minutes of the class kind + + align:start position:0% +the last five minutes of the class kind + + + align:start position:0% +the last five minutes of the class kind +of setting up the discussion of uh how + + align:start position:0% +of setting up the discussion of uh how + + + align:start position:0% +of setting up the discussion of uh how +we should be searching for network + + align:start position:0% +we should be searching for network + + + align:start position:0% +we should be searching for network +motifs okay in particular there's a + + align:start position:0% +motifs okay in particular there's a + + + align:start position:0% +motifs okay in particular there's a +natural question which is um we have to + + align:start position:0% +natural question which is um we have to + + + align:start position:0% +natural question which is um we have to +decide what the right null model is in + + align:start position:0% +decide what the right null model is in + + + align:start position:0% +decide what the right null model is in +terms of deciding uh kind of what the + + align:start position:0% +terms of deciding uh kind of what the + + + align:start position:0% +terms of deciding uh kind of what the +expected frequency of a network Motif + + align:start position:0% +expected frequency of a network Motif + + + align:start position:0% +expected frequency of a network Motif +like a feed forward Loop might + + align:start position:0% + + + + align:start position:0% + +be so first of + + align:start position:0% +be so first of + + + align:start position:0% +be so first of +all why why is it that we think that you + + align:start position:0% +all why why is it that we think that you + + + align:start position:0% +all why why is it that we think that you +know why why is it that we we maybe + + align:start position:0% +know why why is it that we we maybe + + + align:start position:0% +know why why is it that we we maybe +should not use an OS Ry + + align:start position:0% + + + + align:start position:0% + +Network yes doesn't it's not very good + + align:start position:0% +Network yes doesn't it's not very good + + + align:start position:0% +Network yes doesn't it's not very good +for handling + + align:start position:0% +for handling + + + align:start position:0% +for handling +direct right okay so you oh not very + + align:start position:0% +direct right okay so you oh not very + + + align:start position:0% +direct right okay so you oh not very +good I mean I can maybe make I mean I + + align:start position:0% +good I mean I can maybe make I mean I + + + align:start position:0% +good I mean I can maybe make I mean I +can there's a clear analog to a a you + + align:start position:0% +can there's a clear analog to a a you + + + align:start position:0% +can there's a clear analog to a a you +know you can take a a random undirected + + align:start position:0% +know you can take a a random undirected + + + align:start position:0% +know you can take a a random undirected +ER Network and and say you know D you + + align:start position:0% +ER Network and and say you know D you + + + align:start position:0% +ER Network and and say you know D you +know put arrows randomly on each you + + align:start position:0% +know put arrows randomly on each you + + + align:start position:0% +know put arrows randomly on each you +know I mean I think that there's there's + + align:start position:0% +know I mean I think that there's there's + + + align:start position:0% +know I mean I think that there's there's +a natural ER version of a directed + + align:start position:0% +a natural ER version of a directed + + + align:start position:0% +a natural ER version of a directed +Network there + + align:start position:0% +Network there + + + align:start position:0% +Network there +con like + + align:start position:0% + + + + align:start position:0% + +what duplication you don't Rand + + align:start position:0% +what duplication you don't Rand + + + align:start position:0% +what duplication you don't Rand +ass Ed that's right okay so one thing is + + align:start position:0% +ass Ed that's right okay so one thing is + + + align:start position:0% +ass Ed that's right okay so one thing is +it may be that that biologically there + + align:start position:0% +it may be that that biologically there + + + align:start position:0% +it may be that that biologically there +are constraints um but you know and then + + align:start position:0% +are constraints um but you know and then + + + align:start position:0% +are constraints um but you know and then +but that should manifest itself somehow + + align:start position:0% +but that should manifest itself somehow + + + align:start position:0% +but that should manifest itself somehow +in the sense that if you know all that + + align:start position:0% +in the sense that if you know all that + + + align:start position:0% +in the sense that if you know all that +may be well and good it may be true what + + align:start position:0% +may be well and good it may be true what + + + align:start position:0% +may be well and good it may be true what +you're saying but if we go and we look + + align:start position:0% +you're saying but if we go and we look + + + align:start position:0% +you're saying but if we go and we look +at a transcription network if it looks + + align:start position:0% +at a transcription network if it looks + + + align:start position:0% +at a transcription network if it looks +like an ER Network then I would say it + + align:start position:0% +like an ER Network then I would say it + + + align:start position:0% +like an ER Network then I would say it +just doesn't matter right you know the + + align:start position:0% +just doesn't matter right you know the + + + align:start position:0% +just doesn't matter right you know the +fact that that there's microscopic + + align:start position:0% +fact that that there's microscopic + + + align:start position:0% +fact that that there's microscopic +things going on I mean if at the end of + + align:start position:0% +things going on I mean if at the end of + + + align:start position:0% +things going on I mean if at the end of +the day it looks like an ER Network + + align:start position:0% +the day it looks like an ER Network + + + align:start position:0% +the day it looks like an ER Network +then then maybe then maybe it's fine + + align:start position:0% +then then maybe then maybe it's fine + + + align:start position:0% +then then maybe then maybe it's fine +anyways + + align:start position:0% +anyways + + + align:start position:0% +anyways +right or maybe not you know yeah you can + + align:start position:0% +right or maybe not you know yeah you can + + + align:start position:0% +right or maybe not you know yeah you can +argue either way if if a particular I + + align:start position:0% +argue either way if if a particular I + + + align:start position:0% +argue either way if if a particular I +mean it depends on what you want if a + + align:start position:0% +mean it depends on what you want if a + + + align:start position:0% +mean it depends on what you want if a +particular Motif occurs a lot it might + + align:start position:0% +particular Motif occurs a lot it might + + + align:start position:0% +particular Motif occurs a lot it might +be because of the you know it might be + + align:start position:0% +be because of the you know it might be + + + align:start position:0% +be because of the you know it might be +because it's selected for evolution or + + align:start position:0% +because it's selected for evolution or + + + align:start position:0% +because it's selected for evolution or +for some other reason that's right okay + + align:start position:0% +for some other reason that's right okay + + + align:start position:0% +for some other reason that's right okay +so this is an important point that you + + align:start position:0% +so this is an important point that you + + + align:start position:0% +so this is an important point that you +know + + align:start position:0% +know + + + align:start position:0% +know +that right I would say that in in er's + + align:start position:0% +that right I would say that in in er's + + + align:start position:0% +that right I would say that in in er's +approach he basically says if if we see + + align:start position:0% +approach he basically says if if we see + + + align:start position:0% +approach he basically says if if we see +a network Motif more frequently than we + + align:start position:0% +a network Motif more frequently than we + + + align:start position:0% +a network Motif more frequently than we +would expect based on some null model + + align:start position:0% +would expect based on some null model + + + align:start position:0% +would expect based on some null model +some null Network then uh then it's kind + + align:start position:0% +some null Network then uh then it's kind + + + align:start position:0% +some null Network then uh then it's kind +of Prim aish evidence that Evolution was + + align:start position:0% +of Prim aish evidence that Evolution was + + + align:start position:0% +of Prim aish evidence that Evolution was +selecting for it for some reason right + + align:start position:0% +selecting for it for some reason right + + + align:start position:0% +selecting for it for some reason right +and what you're saying is that it could + + align:start position:0% +and what you're saying is that it could + + + align:start position:0% +and what you're saying is that it could +be that that there's a microscopic + + align:start position:0% +be that that there's a microscopic + + + align:start position:0% +be that that there's a microscopic +mechanism that just leads to those + + align:start position:0% +mechanism that just leads to those + + + align:start position:0% +mechanism that just leads to those +things happening and it so it doesn't + + align:start position:0% +things happening and it so it doesn't + + + align:start position:0% +things happening and it so it doesn't +have to be selection it could be just + + align:start position:0% +have to be selection it could be just + + + align:start position:0% +have to be selection it could be just +due to the the mechanistic processes + + align:start position:0% +due to the the mechanistic processes + + + align:start position:0% +due to the the mechanistic processes +below right I think that's a that's a + + align:start position:0% +below right I think that's a that's a + + + align:start position:0% +below right I think that's a that's a +fair concern and it's related to a lot + + align:start position:0% +fair concern and it's related to a lot + + + align:start position:0% +fair concern and it's related to a lot +of these other things and that uh just + + align:start position:0% +of these other things and that uh just + + + align:start position:0% +of these other things and that uh just +for example duplication will naturally + + align:start position:0% +for example duplication will naturally + + + align:start position:0% +for example duplication will naturally +lead to something I mean if you start + + align:start position:0% +lead to something I mean if you start + + + align:start position:0% +lead to something I mean if you start +out with X regulating Y and Y is + + align:start position:0% +out with X regulating Y and Y is + + + align:start position:0% +out with X regulating Y and Y is +duplicated then now you have X + + align:start position:0% +duplicated then now you have X + + + align:start position:0% +duplicated then now you have X +regulating some y1 and also some + + align:start position:0% +regulating some y1 and also some + + + align:start position:0% +regulating some y1 and also some +Y2 right and this is the beginnings of a + + align:start position:0% +Y2 right and this is the beginnings of a + + + align:start position:0% +Y2 right and this is the beginnings of a +network Motif right um and and so it's a + + align:start position:0% +network Motif right um and and so it's a + + + align:start position:0% +network Motif right um and and so it's a +reasonable it's a reasonable thing to + + align:start position:0% +reasonable it's a reasonable thing to + + + align:start position:0% +reasonable it's a reasonable thing to +worry about but maybe we can correct for + + align:start position:0% +worry about but maybe we can correct for + + + align:start position:0% +worry about but maybe we can correct for +at least a majority of this by using the + + align:start position:0% +at least a majority of this by using the + + + align:start position:0% +at least a majority of this by using the +proper null model at least that would be + + align:start position:0% +proper null model at least that would be + + + align:start position:0% +proper null model at least that would be +the + + align:start position:0% +the + + + align:start position:0% +the +hope well right but that's why you don't + + align:start position:0% +hope well right but that's why you don't + + + align:start position:0% +hope well right but that's why you don't +want necessarily okay that's why you + + align:start position:0% +want necessarily okay that's why you + + + align:start position:0% +want necessarily okay that's why you +don't yeah okay that's fair you know but + + align:start position:0% +don't yeah okay that's fair you know but + + + align:start position:0% +don't yeah okay that's fair you know but +then the question is what null model + + align:start position:0% +then the question is what null model + + + align:start position:0% +then the question is what null model +should we be using + + align:start position:0% +should we be using + + + align:start position:0% +should we be using +yeah so I feel like having the + + align:start position:0% +yeah so I feel like having the + + + align:start position:0% +yeah so I feel like having the +microscopic constraints does not + + align:start position:0% +microscopic constraints does not + + + align:start position:0% +microscopic constraints does not +necessarily need to be in the null model + + align:start position:0% +necessarily need to be in the null model + + + align:start position:0% +necessarily need to be in the null model +I feel like we can have a norel without + + align:start position:0% +I feel like we can have a norel without + + + align:start position:0% +I feel like we can have a norel without +using the microscopic constraints and + + align:start position:0% +using the microscopic constraints and + + + align:start position:0% +using the microscopic constraints and +then just say oh well that's another + + align:start position:0% +then just say oh well that's another + + + align:start position:0% +then just say oh well that's another +possibility for why we might have these + + align:start position:0% +possibility for why we might have these + + + align:start position:0% +possibility for why we might have these +divergencies I I don't think they need + + align:start position:0% +divergencies I I don't think they need + + + align:start position:0% +divergencies I I don't think they need +to be in the N model yeah it's just that + + align:start position:0% +to be in the N model yeah it's just that + + + align:start position:0% +to be in the N model yeah it's just that +then you can't say anything about + + align:start position:0% +then you can't say anything about + + + align:start position:0% +then you can't say anything about +Evolution well fair but I don't think + + align:start position:0% +Evolution well fair but I don't think + + + align:start position:0% +Evolution well fair but I don't think +you should have to be I don't think you + + align:start position:0% +you should have to be I don't think you + + + align:start position:0% +you should have to be I don't think you +have to say something about Evolution + + align:start position:0% +have to say something about Evolution + + + align:start position:0% +have to say something about Evolution +afterwards NE yeah and I think that this + + align:start position:0% +afterwards NE yeah and I think that this + + + align:start position:0% +afterwards NE yeah and I think that this +question about how strongly you can + + align:start position:0% +question about how strongly you can + + + align:start position:0% +question about how strongly you can +argue that Evolution selected for + + align:start position:0% +argue that Evolution selected for + + + align:start position:0% +argue that Evolution selected for +something um this is a little bit of a + + align:start position:0% +something um this is a little bit of a + + + align:start position:0% +something um this is a little bit of a +judgment call all right because most of + + align:start position:0% +judgment call all right because most of + + + align:start position:0% +judgment call all right because most of +these evolutionary arguments are not + + align:start position:0% +these evolutionary arguments are not + + + align:start position:0% +these evolutionary arguments are not +Ironclad you know there it's more a + + align:start position:0% +Ironclad you know there it's more a + + + align:start position:0% +Ironclad you know there it's more a +matter of making you feel yeah kind of + + align:start position:0% +matter of making you feel yeah kind of + + + align:start position:0% +matter of making you feel yeah kind of +comfortable with looking for what the + + align:start position:0% +comfortable with looking for what the + + + align:start position:0% +comfortable with looking for what the +evolution explanation might have been + + align:start position:0% +evolution explanation might have been + + + align:start position:0% +evolution explanation might have been +you know and that this is just I mean + + align:start position:0% +you know and that this is just I mean + + + align:start position:0% +you know and that this is just I mean +the nature of looking at I mean of + + align:start position:0% +the nature of looking at I mean of + + + align:start position:0% +the nature of looking at I mean of +historical science right um I mean you + + align:start position:0% +historical science right um I mean you + + + align:start position:0% +historical science right um I mean you +can speculate about what would have + + align:start position:0% +can speculate about what would have + + + align:start position:0% +can speculate about what would have +happened if Napoleon had done something + + align:start position:0% +happened if Napoleon had done something + + + align:start position:0% +happened if Napoleon had done something +else or whatever right but uh you know + + align:start position:0% +else or whatever right but uh you know + + + align:start position:0% +else or whatever right but uh you know +it's a it's you speculation I mean of + + align:start position:0% +it's a it's you speculation I mean of + + + align:start position:0% +it's a it's you speculation I mean of +course you know the hope is that we can + + align:start position:0% +course you know the hope is that we can + + + align:start position:0% +course you know the hope is that we can +collect multiple pieces of evidence that + + align:start position:0% +collect multiple pieces of evidence that + + + align:start position:0% +collect multiple pieces of evidence that +make us more and more comfortable with + + align:start position:0% +make us more and more comfortable with + + + align:start position:0% +make us more and more comfortable with +it in some cases we can do laboratory + + align:start position:0% +it in some cases we can do laboratory + + + align:start position:0% +it in some cases we can do laboratory +Evolution to get more Comfort right but + + align:start position:0% +Evolution to get more Comfort right but + + + align:start position:0% +Evolution to get more Comfort right but +you know laboratory Evolution doesn't + + align:start position:0% +you know laboratory Evolution doesn't + + + align:start position:0% +you know laboratory Evolution doesn't +prove that that's what happened you know + + align:start position:0% +prove that that's what happened you know + + + align:start position:0% +prove that that's what happened you know +a million years ago either right but I'd + + align:start position:0% +a million years ago either right but I'd + + + align:start position:0% +a million years ago either right but I'd +say it's it's more the accumulation of + + align:start position:0% +say it's it's more the accumulation of + + + align:start position:0% +say it's it's more the accumulation of +evidence to make you feel comfortable + + align:start position:0% +evidence to make you feel comfortable + + + align:start position:0% +evidence to make you feel comfortable +with an argument um but we you know + + align:start position:0% +with an argument um but we you know + + + align:start position:0% +with an argument um but we you know +let's first maybe make sure we + + align:start position:0% +let's first maybe make sure we + + + align:start position:0% +let's first maybe make sure we +understand what the null model is and + + align:start position:0% +understand what the null model is and + + + align:start position:0% +understand what the null model is and +then we can maybe and then you know and + + align:start position:0% +then we can maybe and then you know and + + + align:start position:0% +then we can maybe and then you know and +then on Thursday we'll decide whether + + align:start position:0% +then on Thursday we'll decide whether + + + align:start position:0% +then on Thursday we'll decide whether +well decide and we'll we'll we'll + + align:start position:0% +well decide and we'll we'll we'll + + + align:start position:0% +well decide and we'll we'll we'll +discuss what we think that means about + + align:start position:0% +discuss what we think that means about + + + align:start position:0% +discuss what we think that means about +Evolution yeah yeah so I think um what + + align:start position:0% +Evolution yeah yeah so I think um what + + + align:start position:0% +Evolution yeah yeah so I think um what +we the other part and the PEX that we + + align:start position:0% +we the other part and the PEX that we + + + align:start position:0% +we the other part and the PEX that we +read about the in and out distributions + + align:start position:0% +read about the in and out distributions + + + align:start position:0% +read about the in and out distributions +is important for the N model + + align:start position:0% +is important for the N model + + + align:start position:0% +is important for the N model +yes it seems to me + + align:start position:0% +yes it seems to me + + + align:start position:0% +yes it seems to me +that Network might be a good model for + + align:start position:0% +that Network might be a good model for + + + align:start position:0% +that Network might be a good model for +the IND + + align:start position:0% +the IND + + + align:start position:0% +the IND +distributions but not for the out + + align:start position:0% +distributions but not for the out + + + align:start position:0% +distributions but not for the out +distribtion that's + + align:start position:0% +distribtion that's + + + align:start position:0% +distribtion that's +right yeah and I think this is this is + + align:start position:0% +right yeah and I think this is this is + + + align:start position:0% +right yeah and I think this is this is +really important I think that it it's + + align:start position:0% +really important I think that it it's + + + align:start position:0% +really important I think that it it's +clear that the that the actual + + align:start position:0% +clear that the that the actual + + + align:start position:0% +clear that the that the actual +transcription network of eai for example + + align:start position:0% +transcription network of eai for example + + + align:start position:0% +transcription network of eai for example +is not well described as an erish or any + + align:start position:0% +is not well described as an erish or any + + + align:start position:0% +is not well described as an erish or any +kind of random Network U but then it + + align:start position:0% +kind of random Network U but then it + + + align:start position:0% +kind of random Network U but then it +kind of does big the question of of what + + align:start position:0% +kind of does big the question of of what + + + align:start position:0% +kind of does big the question of of what +should we be using and you could say + + align:start position:0% +should we be using and you could say + + + align:start position:0% +should we be using and you could say +well we just we just make a power law + + align:start position:0% +well we just we just make a power law + + + align:start position:0% +well we just we just make a power law +network but then you say oh but there's + + align:start position:0% +network but then you say oh but there's + + + align:start position:0% +network but then you say oh but there's +the in degree and the out degree you + + align:start position:0% +the in degree and the out degree you + + + align:start position:0% +the in degree and the out degree you +know how much do you want to keep track + + align:start position:0% +know how much do you want to keep track + + + align:start position:0% +know how much do you want to keep track +of that and I think that there's a a + + align:start position:0% +of that and I think that there's a a + + + align:start position:0% +of that and I think that there's a a +fairly strong argument that what you + + align:start position:0% +fairly strong argument that what you + + + align:start position:0% +fairly strong argument that what you +should do is what they call this degree + + align:start position:0% +should do is what they call this degree + + + align:start position:0% +should do is what they call this degree +preserving + + align:start position:0% + + + + align:start position:0% + +Network and in particular what that + + align:start position:0% +Network and in particular what that + + + align:start position:0% +Network and in particular what that +means is + + align:start position:0% +means is + + + align:start position:0% +means is +that you take all of you take the real + + align:start position:0% +that you take all of you take the real + + + align:start position:0% +that you take all of you take the real +Network right so you take the actual + + align:start position:0% +Network right so you take the actual + + + align:start position:0% +Network right so you take the actual +Network that you're going to be + + align:start position:0% +Network that you're going to be + + + align:start position:0% +Network that you're going to be +analyzing and there there is some + + align:start position:0% +analyzing and there there is some + + + align:start position:0% +analyzing and there there is some +actual degree distribution right so + + align:start position:0% +actual degree distribution right so + + + align:start position:0% +actual degree distribution right so +there's you know one node has you know + + align:start position:0% +there's you know one node has you know + + + align:start position:0% +there's you know one node has you know +so K1 might be + + align:start position:0% +so K1 might be + + + align:start position:0% +so K1 might be +106 K2 might be 7 + + align:start position:0% +106 K2 might be 7 + + + align:start position:0% +106 K2 might be 7 +73 dot dott dot dot you know up to KNN + + align:start position:0% +73 dot dott dot dot you know up to KNN + + + align:start position:0% +73 dot dott dot dot you know up to KNN +which is equal to one and of course I'm + + align:start position:0% +which is equal to one and of course I'm + + + align:start position:0% +which is equal to one and of course I'm +not even talking about it being directed + + align:start position:0% +not even talking about it being directed + + + align:start position:0% +not even talking about it being directed +but you can do the same thing with + + align:start position:0% +but you can do the same thing with + + + align:start position:0% +but you can do the same thing with +directed right um but then what you do + + align:start position:0% +directed right um but then what you do + + + align:start position:0% +directed right um but then what you do +is you kind of mix things up so you + + align:start position:0% +is you kind of mix things up so you + + + align:start position:0% +is you kind of mix things up so you +start with the real Network and then you + + align:start position:0% +start with the real Network and then you + + + align:start position:0% +start with the real Network and then you +do something to randomize it right and + + align:start position:0% +do something to randomize it right and + + + align:start position:0% +do something to randomize it right and +and it's a rather clever scheme I'm just + + align:start position:0% +and it's a rather clever scheme I'm just + + + align:start position:0% +and it's a rather clever scheme I'm just +going to describe it briefly here and + + align:start position:0% +going to describe it briefly here and + + + align:start position:0% +going to describe it briefly here and +then we'll talk more about it on + + align:start position:0% +then we'll talk more about it on + + + align:start position:0% +then we'll talk more about it on +Thursday what you do is you take all of + + align:start position:0% +Thursday what you do is you take all of + + + align:start position:0% +Thursday what you do is you take all of +the actual + + align:start position:0% +the actual + + + align:start position:0% +the actual +uh so let's say we have some X1 some X2 + + align:start position:0% +uh so let's say we have some X1 some X2 + + + align:start position:0% +uh so let's say we have some X1 some X2 +and some here we have a y y 1 a + + align:start position:0% +and some here we have a y y 1 a + + + align:start position:0% +and some here we have a y y 1 a +Y2 a Y3 okay now let's say that these + + align:start position:0% +Y2 a Y3 okay now let's say that these + + + align:start position:0% +Y2 a Y3 okay now let's say that these +guys are regulating something like this + + align:start position:0% +guys are regulating something like this + + + align:start position:0% +guys are regulating something like this +what you do is you take two edges + + align:start position:0% +what you do is you take two edges + + + align:start position:0% +what you do is you take two edges +randomly we'll claim we CL pick this one + + align:start position:0% +randomly we'll claim we CL pick this one + + + align:start position:0% +randomly we'll claim we CL pick this one +and that one what we do is we + + align:start position:0% +and that one what we do is we + + + align:start position:0% +and that one what we do is we +swap the um the targets okay so what we + + align:start position:0% +swap the um the targets okay so what we + + + align:start position:0% +swap the um the targets okay so what we +do is we make this guy come over here + + align:start position:0% +do is we make this guy come over here + + + align:start position:0% +do is we make this guy come over here +and then this one comes over + + align:start position:0% +and then this one comes over + + + align:start position:0% +and then this one comes over +here okay so now what we do is we erase + + align:start position:0% +here okay so now what we do is we erase + + + align:start position:0% +here okay so now what we do is we erase +this we erase this now we have a new + + align:start position:0% +this we erase this now we have a new + + + align:start position:0% +this we erase this now we have a new +network but intriguingly the degree + + align:start position:0% +network but intriguingly the degree + + + align:start position:0% +network but intriguingly the degree +distributions for both incoming and + + align:start position:0% +distributions for both incoming and + + + align:start position:0% +distributions for both incoming and +outgoing edges are identical to what we + + align:start position:0% +outgoing edges are identical to what we + + + align:start position:0% +outgoing edges are identical to what we +had before this right you know every guy + + align:start position:0% +had before this right you know every guy + + + align:start position:0% +had before this right you know every guy +has the same outgoing edges incoming + + align:start position:0% +has the same outgoing edges incoming + + + align:start position:0% +has the same outgoing edges incoming +edges but they're just they have + + align:start position:0% +edges but they're just they have + + + align:start position:0% +edges but they're just they have +different targets right so if you just + + align:start position:0% +different targets right so if you just + + + align:start position:0% +different targets right so if you just +do this procedure many many times then + + align:start position:0% +do this procedure many many times then + + + align:start position:0% +do this procedure many many times then +what you do is you achieve some + + align:start position:0% +what you do is you achieve some + + + align:start position:0% +what you do is you achieve some +randomized version of the real Network + + align:start position:0% +randomized version of the real Network + + + align:start position:0% +randomized version of the real Network +okay and then what you can do is you can + + align:start position:0% +okay and then what you can do is you can + + + align:start position:0% +okay and then what you can do is you can +ask you can ask how many feed forward + + align:start position:0% +ask you can ask how many feed forward + + + align:start position:0% +ask you can ask how many feed forward +Loops are there how many you know this + + align:start position:0% +Loops are there how many you know this + + + align:start position:0% +Loops are there how many you know this +that + + align:start position:0% +that + + + align:start position:0% +that +right and so I think that there's a fair + + align:start position:0% +right and so I think that there's a fair + + + align:start position:0% +right and so I think that there's a fair +argument that this is in some ways the + + align:start position:0% +argument that this is in some ways the + + + align:start position:0% +argument that this is in some ways the +proper null model to be asking the + + align:start position:0% +proper null model to be asking the + + + align:start position:0% +proper null model to be asking the +question and indeed for example there + + align:start position:0% +question and indeed for example there + + + align:start position:0% +question and indeed for example there +are many more feed forward Loops than + + align:start position:0% +are many more feed forward Loops than + + + align:start position:0% +are many more feed forward Loops than +there would be in an Eros reny but still + + align:start position:0% +there would be in an Eros reny but still + + + align:start position:0% +there would be in an Eros reny but still +what you see is that you lose many feed + + align:start position:0% +what you see is that you lose many feed + + + align:start position:0% +what you see is that you lose many feed +forward Loops so this is this is then + + align:start position:0% +forward Loops so this is this is then + + + align:start position:0% +forward Loops so this is this is then +the argument for U for feed for Loops + + align:start position:0% +the argument for U for feed for Loops + + + align:start position:0% +the argument for U for feed for Loops +being selected for right we'll talk + + align:start position:0% +being selected for right we'll talk + + + align:start position:0% +being selected for right we'll talk +about this and we'll quantify it on + + align:start position:0% +about this and we'll quantify it on + + + align:start position:0% +about this and we'll quantify it on +Thursday but I'm available for the next + + align:start position:0% +Thursday but I'm available for the next + + + align:start position:0% +Thursday but I'm available for the next +half hour if anybody has any questions + + align:start position:0% +half hour if anybody has any questions + + + align:start position:0% +half hour if anybody has any questions +all right \ No newline at end of file diff --git a/Posv6O0845c.txt b/Posv6O0845c.txt new file mode 100644 index 0000000000000000000000000000000000000000..cf74e89157c4ef0f08974a8d8acef4d0098296d7 --- /dev/null +++ b/Posv6O0845c.txt @@ -0,0 +1,2900 @@ +The following +content is provided + +under a Creative +Commons license. + +Your support will help MIT +OpenCourseWare continue + +to offer high quality +educational resources for free. + +To make a donation or to +view additional materials + +from hundreds of MIT courses, +visit MIT OpenCourseWare + +at ocw.mit.edu. + +TIM RAY: I guess +first of all I wanted + +to entertain any questions you +might've had about the concert. + +I know Mark is having you +write up some reports. + +Actually I got an advanced +copy of one person's report + +that had some really +interesting comments. + +One of the comments +that this person wrote + +was about hearing-- +trying to listen + +for the difference between +the improvised sections + +and the written sections. + +What was your feeling on that? + +Did you feel like you had +a pretty good sense of when + +we were improvising and when +we were playing written music? + +Was it a little hard to +tell sometimes, right? + +I actually tell-- we hear +that comment a lot, actually. + +Including from symphony players. + +It might have been hard for you +to tell, don't think that means + +anything negative. + +Like I say, a lot of musicians +come up to us afterwards + +and they go, I don't know +what you guys were doing, + +or how you were +blending the composition + +and the improvisation. + +And that's, to me, is sort +of an affirmation of one + +of my goals for this group, +is to blend composition + +and improvisation in +kind of a seamless way. + +I mean, it's obviously +not seamless, + +but to make that-- make +those lines blurry. + +And I think a lot of +composers of modern music-- + +I know Mark Harvey's +compositions do somewhat + +the same thing, as well +as of course Greg's. + +And a lot of people +I know sometimes + +look for that kind of blurry +line between composition + +improvisation. + +Because it's really all +the same thing, right? + +It's just composition, +you write it down. + +Improvisation is +spontaneous, but still it's + +all kind of the same thing. + +The piece that you transcribed +from an improvisation, + +did you play that-- +were you playing it + +exactly how it +sounded originally? + +Or did you kind +of reinterpret it? + +Because it sounded +like a real piece. + +[LAUGHTER] + +Yeah, that's-- + +GREG HOPKINS: (LAUGHING) +What do you mean by that? + +TIM RAY: Yeah, right. + +GREG HOPKINS: I +know what you mean. + +I know exactly what you mean. + +TIM RAY: Sounded like real +music, not improvisation. + +No, I'm teasing. + +No, that's a good question. + +That's another one +people ask a lot. + +Yeah, that was, again, +that was sort of Eugene's. + +That was something +that he had improvised + +with a different piano player +years ago in this cathedral. + +Now he talked about it +a little bit, I know. + +GREG HOPKINS: Oh, you're talking +about the piano-cello piece. + +TIM RAY: Yeah, the +piano-cello piece, right. + +And as he said, +they wrote it out. + +I mean, they wrote it out. + +Eugene kind of just +memorized his cello part. + +And his part was +pretty much as played, + +as improvised back however +many years ago that was. + +And then the piano part, they +wrote it out and of course, + +being a jazz player +I changed it. + +So I mean I basically +followed the intent of it, + +you know, and I played +something specific to what + +was played back then, as +according to the music. + +But then I did some other-- +I changed it up a little bit. + +Made it a little +bit more-- gave it + +a little bit of a personal +thing, a personal touch. + +But yeah, that's +one of the things. + +I know you weren't +here last week + +when we were doing the thing +with diatonic improvisation, + +but basically that's +what that was. + +It was a whole thing +about just improvising + +in the key of D major. + +And Eugene and this +guy, Paul Halley, + +was the pianist, basically +did an amazing job of kind + +of creating this thing. + +And as you said, it +sounded like real music. + +It sounded like something +that could have been composed. + +It had sections and +melody in the cello, + +melody in the piano, +all kinds of variations + +and accompaniments. + +And like I said, +that was just one + +of those things that kind +of worked out really well + +improvisationally and +happened to be recorded. + +And so that that's why +it keeps getting played. + +But yeah, so I don't know if +that answered your question, + +but that's kind of +the genesis of that. + +So, cool. + +And then Greg and I-- + +GREG HOPKINS: He probably played +the piece though, many times, + +right? + +TIM RAY: Yeah, yeah. + +Eugene's played that +piece many times. + +GREG HOPKINS: So it's not +improvisation of the moment, + +it's a creation that he +recreates many times over + +and over and over. + +So they kind of played +it similar each time. + +TIM RAY: Right, yeah. + +You know, and +sometimes it's funny + +because we, Greg and I and Mark, +are kind of jazz-- you know, + +what we might call +hardcore jazz guys. + +Who sort of believe +in the sanctity + +of spontaneous improvisation. + +But actually, if you look back +not that long ago in history + +that happened a lot. + +Duke Ellington spans +a perfect example. + +Cootie Williams would +take a trumpet solo + +and Duke would say, I like +that, do that solo again. + +The next thing you know, +that Cootie Williams solo + +becomes part of the book. + +What started off as an +improvisation, or at least + +largely as an improvisation, +became part of the music. + +So there's a little bit of +history even in the jazz + +world-- + +GREG HOPKINS: Well, +a lot of jazz music + +starts out as improvisation +and becomes concrete. + +Like some of Charlie +Parker's tunes. + +And he would play them +the same each time. + +OK, this is the melody. + +And they're nothing but, +really, improvisations + +that become part of history. + +TIM RAY: Indeed. + +And then, the duet +that Greg and I + +did, I made a little comment +at the beginning about I + +didn't know what +was going to happen. + +And it's kind of +true, I don't really + +know what's going to happen. + +That's one of those +moments, which + +I like to do in our program, and +Greg and I have done this a lot + +over the course of our-- + +GREG HOPKINS: We never decide +what tune we're going to play. + +TIM RAY: Yeah, well +we don't decide it. + +I'm happy to have Greg start. + +And I don't know, did you-- +when you started did you know-- + +GREG HOPKINS: I had no idea. + +TIM RAY: I had a +feeling you were-- + +GREG HOPKINS: I was +searching around, + +I was kind of doing a +little prelude stuff. + +Saying, now what do I feel +like I want to play here? + +Well, we just played something +in sharp key so I said, + +we're going to go into flats. + +Because I wanted to +have a different taste. + +And A-flat came out, OK, well +let's-- I know this tune. + +And, hey let's play +rhythm changes in A-flat, + +and then we went into +the Thelonious Monk + +tune "Little Rootie Tootie". + +Which we-- I know that +Tim knows and I know. + +So basically after a +little fooling around, + +OK, let's do that, no problem. + +But we had fun +with Monk's riffs, + +so then we really +played the composition. + +And as a composer, I think +that's-- I really appreciate + +that, when an improviser or a +soloist plays the composition. + +Because that's a strong way +to approach a improvisation-- + +playing the musical composition +instead of just playing + +your horn, your instrument. + +And playing a bunch of licks +and making the changes is fine, + +but what does it all mean +related to Mr. Monk's music? + +Because I put myself not +as so much a soloist, + +it's not about me +as much as it's + +about how can I interpret +his composition. + +So I'm more like the conduit +instead of the focal point. + +So we had a lot of +fun with his riffs. + +TIM RAY: Yeah, we did. + +And that gets a little bit back +to what we were talking about + +with the assignment, +which is this tune + +of Greg's, [? "Karagassian". ?] + +GREG HOPKINS: Oh, +you have that one? + +TIM RAY: Yeah, you guys +all brought it, right? + +All right, so we're going to +start playing in just a second. + +But the idea, being to-- +obviously, get the foundation. + +In other words, +learn the melody, + +get comfortable with the minor +blues progression-- which + +is what the improvisation +is based on-- if you're not + +already comfortable +with that, and then use + +some of the motifs in the melody +to inform your improvisation. + +Use to improvise in the motivic +fashion, as much as you can. + +I mean, you don't-- +obviously, no one-- well, + +I shouldn't say no one. + +It would be rare to hear +an improvisation created + +completely out of motivic +stuff, although I'm + +sure it's been done. + +GREG HOPKINS: Sure it is. + +TIM RAY: Some of my favorite +improvisers do that. + +I mean they don't-- + +GREG HOPKINS: I'm always +playing the melody up here. + +Even when I play a standard +tune, I'm on the melody. + +So then you're never at +a loss for what to do. + +I don't really have +to think of something. + +It's here. + +Do something with that. + +TIM RAY: Yeah, that's true. + +GREG HOPKINS: But then +what do you do with it? + +You have to know your +compositional techniques. + +Repetition, sequence, +transposition, elongation, + +augmentation, diminution, +transformation, embellishment, + +all that stuff. + +TIM RAY: Yeah, absolutely. + +GREG HOPKINS: And +then sometimes we + +play stuff, little +cannons back and forth. + +Question and answer, +question and answer. + +TIM RAY: Yeah, cool. + +So, should we jump +into this piece? + +What do we think? + +Yeah, we've got plenty of time. + +OK, so [? "Karagassian". ?] I +know I suggested maybe we have + +you guys do some-- you +know, pair up to do some + +improvisations. + +But maybe just for +rehearsal sake, + +why don't we all +play the melody. + +And we'll see if we're +on the same page. + +GREG HOPKINS: So, as you know +this is written for my cat. + +My late cat [? Karagassian. ?] +I wrote the piece probably + +in 15 minutes. + +It just came out. + +Because the cat +had so much spirit. + +And it's all here. + +You know cats, +they're very playful. + +So this melody's very playful. + +It's meant to be had +a lot of fun with. + +TIM RAY: Yes, indeed. + +So yeah, so let's +all play the melody. + +If you guys on guitar +want to do some chord + +changes in the +three-four measure + +you can, or you can just +stay with the melody + +if you want to do that. + +Let's just do that and +see where we're at. + +And then we'll get +into some improv. + +Do you want to +count it off, Greg? + +GREG HOPKINS: One, +two, a one, two, three. + +[MUSIC PLAYING] + +TIM RAY: That's a hard one. + +[MUSIC PLAYING] + +All right. + +Not bad. + +GREG HOPKINS: Not bad at all. + +But the inflection +is pretty good. + +Yeah, it's really +soft and distant. + +And then in the third measure +we can clobber that note. + +Actually, play a different +note than E-flat. + +That's like a crash. + +One more time. + +A one, two, a one, two. + +Yeah, but softer. + +Much softer. + +Just touch it. + +One, two, a one, two. + +That's it. + +One, two. + +Loud. + +Two, three,four. + +One, two. + +So I always put a doit on that. + +You know what a doit is? + +Where you fall up? + +It's a fall up instead +of a fall down. + +TIM RAY: Yeah, it's always +hard on a piano, right? + +I usually just +[INAUDIBLE] short little-- + +GREG HOPKINS: +That's an old term , + +nobody talks about +that stuff anymore. + +D-O-I-T it's called doit. + +Doy-eet. + +TIM RAY: Where are we? + +GREG HOPKINS: Bar nine. + +Third line. + +Two, a one, two, three. + +Two, three. + +Three, four. + +Two, three. + +Three, four. + +Good. + +A two, a one, two. + +Quiet. + +Two, three. + +Yeah, nice. + +So the fermata would +just be for the ending. + +And then we would go +to that three four bar + +and then go right back to the +beginning and start the blues. + +TIM RAY: The blues is +in four four by the way, + +and I know the chart's +not clear about that. + +But, yeah four four blues. + +For the improv. + +GREG HOPKINS: Yeah. + +So the whole ending +part is supposed + +to create this tension, +a little angst. + +With the rhythm, four against +three, and then the four + +goes faster than you think. + +And then when we start +to play the blues form, + +it relaxes back +to regular tempo. + +So the cat's kind of clawing +its way up the curtain. + +But we don't play-- we +don't improvise on that, + +but you could certainly +include the motifs + +in your improvisations. + +TIM RAY: Cool. + +GREG HOPKINS: Should we +do it with some solos? + +TIM RAY: Yeah, let's +do it with some solos. + +Yeah. + +GREG HOPKINS: Now, we perform +it as a totally conversational + +piece. + +There's no accompaniment. + +Everybody's just soloing +at the same time, which + +is an interesting +style which I like. + +I tend to play a lot less when +I'm playing conversationally. + +Because you want the +person to talk back to you. + +You can't be like +some professors who + +just talk and talk +and talk and talk + +and you can't say anything. + +OK. + +Just take notes. + +TIM RAY: Cool. + +But you want to-- maybe +we'll start with-- well, + +let's play the melody again. + +And then, and then maybe we'll +do a little bit of soloing. + +I'll maybe keep the form-- + +GREG HOPKINS: It's going to +be tough with this many people + +to play conversationally. + +TIM RAY: Yeah, well maybe +by the end we'll get there. + +We won't start there, though. + +But I would like to hear +some people kind of pair off. + +But you want-- maybe we should +do, like, individually first. + +GREG HOPKINS: Yeah, I think so. + +Let's do a chorus each. + +TIM RAY: Cool, all right. + +GREG HOPKINS: And will you comp? + +TIM RAY: Yeah, +I'll do some comp. + +GREG HOPKINS: Yeah, do +some typical comping. + +Base notes, you play the melody. + +I mean, all you need +really is base and melody. + +Two parts to have counterpoint. + +Any two lines could +be counterpointal. + +Then there's conversational. + +Much more fun than +playing alone. + +GUEST SPEAKER: And we've +all-- everybody's assignment + +was to prepare, right? + +Some thoughts about how +you would treat the motif. + +So why don't we start there? + +Then we see how that expands. + +TIM RAY: Cool. + +GREG HOPKINS: So, do the melody +once and then we'll start. + +So just go around, +you want to go first? + +We'll go around. + +We can start there. + +A one, two. + +[MUSIC PLAYING] + +TIM RAY: Yeah, all right. + +Cool. + +Let's stop there. + +Nice, all right. + +Great, it's great to +hear all of you play. + +Excellent, thank you. + +GREG HOPKINS: So we +all played one chorus. + +TIM RAY: Yeah, so we +all did one chorus. + +While I heard a lot +of really nice ideas, + +I didn't hear a whole +lot of use of the motifs. + +Let's look at those real quick. + +GREG HOPKINS: I heard +the first motif a lot. + +TIM RAY: Did you? + +OK. + +GREG HOPKINS: Yeah, +some of you played + +that opening, which +I did five times. + +But I transposed it each time. + +So it kind of created a +little line cliche, as we say. + +TIM RAY: Indeed. + +Indeed. + +Right. + +So that first one, I think +we looked at these just + +briefly last time. + +Yeah, the first one +is a good one to grab. + +The repeated note, +that's a nice one. + +GREG HOPKINS: Number +two, number two. + +That's funky. + +TIM RAY: That's +pretty funky, yeah. + +GREG HOPKINS: You +could go [PLAYS MUSIC]. + +You could go [PLAYS MUSIC]. + +You could go [PLAYS MUSIC]. + +You could go [PLAYS MUSIC]. + +You could go [PLAYS MUSIC]. + +Just play it, you +could do-- yeah, + +we could do several +choruses just on that. + +TIM RAY: Just on that, I know. + +And we probably have. + +GREG HOPKINS: By +changing notes, I'm + +using the rhythmic +contours of motif. + +So, the da da da da, I could +do anything I want there. + +[PLAYS MUSIC] + +Yeah. + +You could work your way through +creating interesting melodies + +by changing the notes. + +TIM RAY: Yeah, absolutely. + +Do you want to do a little +motivic exercise, maybe? + +We'll go-- we'll +do the same thing. + +We'll go around the-- + +GREG HOPKINS: Let's +just play that motif. + +Da da da da. + +TIM RAY: Yeah. + +GREG HOPKINS: So you +can play four notes. + +One two three four. + +You can play any +intervals, though. + +TIM RAY: Cool. + +GREG HOPKINS: Not yet. + +This is my warm up, +Mark, for the day. + +[LAUGHTER] + +GUEST SPEAKER: Pretty good. + +GREG HOPKINS: It's a +good tune to warm up on. + +TIM RAY: It is. + +So, you want to do +everybody four measures? + +GREG HOPKINS: Let's do-- + +TIM RAY: [INAUDIBLE] + +Sure. + +Four bars each. + +TIM RAY: What do you think? + +OK. + +Just doing that motif. + +Just the repeated note motif. + +All right. + +Why don't you start. + +GREG HOPKINS: A two, a one, two. + +Good Nice idea. + +Yeah. + +Do another one. + +You go. + +One. + +AUDIENCE: From this [INAUDIBLE]? + +GREG HOPKINS: Yeah. + +Flute. + +TIM RAY: You ready? + +Yeah, nice. + +GREG HOPKINS: Next solo. + +[LAUGHTER] + +Yeah. + +So we're setting parameters now. + +You have to use that material +and create with that. + +It's like, I mean we're +sculptors, Let's face it, + +we're just shaping stuff +out of these materials. + +So sometimes it's really +good to limit yourself. + +That's what an etude +is, an etude is always + +like one idea for +the whole page. + +And the composer of +the etude does it + +in all the different +keys so you'll learn it. + +So it's really good to set the +parameters like that I think. + +TIM RAY: Yeah, oh +I think so too. + +I think it's a great +way to-- you know, + +there's all kinds of parameters. + +You can obviously-- we're +doing the little motivic thing + +with the four +notes, but you can, + +obviously-- there's any +number of other motifs + +you could do that with. + +You can do set +parameters, as far + +as the range of +your instruments, + +or dynamics, or +rhythmic density, + +you know, do a solo +with all quarter notes. + +Right? + +Or do a solo with all +quarter note triplets, right? + +Something like that, +that's another great way + +to kind of expand your range. + +In other words, +expand your range + +of what you're doing +with improvisation. + +Let's do another one of those. + +Let's see, what's another +good motif to grab? + +GREG HOPKINS: Bar +nine is pretty good. + +That might be a little hard. + +Well, the opening motif is good. + +TIM RAY: Cool. + +Cool. + +Yeah, let's do the same thing. + +Four measures again? + +GREG HOPKINS: Four measures. + +We'll do the opening motif. + +Two, a one, two, three. + +Nice. + +Nice. + +Go ahead. + +Change direction. + +Nice. + +TIM RAY: Yeah. + +GREG HOPKINS: OK. + +So, I mean, how would you +practice something like that? + +Well, let's play that motif. + +Just those three notes. + +OK, let's go up in half steps. + +So I'm going to sequence it, I'm +going to play it in every key. + +OK, and then we +go (PLAYS MUSIC). + +Yeah. + +So the first one, D +G, D G, D G D. Now, + +what am I-- I'm +hearing in my head, + +I'm hearing five one five. + +So I'm hearing it in the key. + +Up a half. + +So an A-flat now. + +Let's do it in A. A. + +Next key. + +Next key. + +Next key. + +Next key. + +Yeah, good. + +OK? + +So then we could (PLAYS MUSIC). + +You can put it in, and we could +do the same thing going down. + +We could do the motif down. + +I mean, that's what you +do when you practice. + +You do really mundane-- +maybe not mundane, + +you do really small, +little things. + +I mean, it might +take me 10 minutes + +to really feel comfortable +with that, just those intervals + +going up in sequences like that. + +TIM RAY: Yeah, absolutely. + +GREG HOPKINS: And then +you could sequence + +things four different ways. + +Let's sequence it +in whole steps. + +Up a whole step, I'm going to +go up a whole step each time. + +Too high? + +Yeah. + +So the person is going +to be in G then A then B + +then C-sharp, then E-flat, +then F, and then G again. + +Right? + +TIM RAY: Yeah. + +Absolutely. + +GREG HOPKINS: Can we do that? + +TIM RAY: Sure. + +GREG HOPKINS: Let's just go up. + +Skip the first note. + +Now I'm going to sequence +just the first measure. + +Right. + +That's it. + +There I go. + +It's the whole thing, now +it's a whole different animal. + +Now it sounds like a +progression, right? + +TIM RAY: It does. + +Yeah, absolutely. + +GREG HOPKINS: So +that creates it. + +And we can do it +in minor thirds. + +OK? + +Let's do that over a G pedal. + +Yeah, that creates kind +of a bluesy feeling. + +It's like a G diminished chord. + +TIM RAY: Yeah, absolutely. + +Right, yeah. + +GREG HOPKINS: So now I'm +creating counterpoint just + +with the motif. + +Then we could do +it in major thirds. + +That's an interesting one too-- + +TIM RAY: It is. + +GREG HOPKINS: You think? + +TIM RAY: Oh yeah. + +Absolutely. + +GREG HOPKINS: This is-- I +learned all this from him. + +[LAUGHTER] + +Let's do that over a D pedal. + +TIM RAY: Sure. + +GREG HOPKINS: One, two. + +Then we could do cycle four. + +So we did half steps, +whole steps, minor thirds, + +major thirds, what's +the next interval? + +Above a major third +is a perfect fourth. + +So this is going-- there's +going to be 12 of them. + +This is cycle five, right? + +TIM RAY: Sure, yeah. + +Yeah, right. + +Or you can just-- + +GREG HOPKINS: Now we're +going to expand it. + +We're going to +play a minor triad. + +Instead of just one five, we're +going to play one three five. + +Let's play up and +down a minor triad. + +So we embellished the lick. + +That's fine. + +You can add notes +whenever you want. + +Why'd you do that? + +I wanted to. + +G minor, so now we're +going to do cycles, + +so we're going to go a forth +up to C minor, fourth up to F + +minor, B-flat minor, E-flat +minor, A-flat minor, D-flat + +minor, G-flat minor, B minor, +E minor, A minor, D minor, + +back to G. Slowly. + +Ready, go. + +So now I'm going to +take that same idea + +and do it in whole steps. + +And so on. + +It's all just grunt work. + +But that's what Coltrane did. + +He used to practice in his +apartment eight hours a day. + +Eight hours a day just on +these-- what he was playing. + +He made up his own etudes. + +Yeah, he did. + +Which is what all the good-- +all the great players do. + +TIM RAY: Yeah, absolutely. + +I mean, certainly-- + +GREG HOPKINS: This is the model. + +This is the model. + +This has dozens of ideas. + +TIM RAY: Yeah, and +certainly that's + +the idea of any kind of +work on improvisation. + +You know, when you're sitting +alone at home thinking, + +you know, because +everyone always says, + +well I don't know how to +practice improvisation. + +GREG HOPKINS: Yeah, +what should I do? + +Oh, I'm going to play +my scales every day. + +OK, that's fine. + +TIM RAY: Because +it's spontaneous. + +GREG HOPKINS: You got make +goals, a set of goals. + +And we can tell you what goals, +what projects to work on. + +TIM RAY: But yeah. + +But a lot of it's just about +coming up with stuff like this. + +Obviously, as Greg said, +we can tell you stuff + +or you could go +buy books that have + +patterns and stuff like that. + +And that's all great, +but sometimes it's + +just about what +we're doing, which + +is like, OK, let's try that. + +Now let's try it up a fourth. + +And let's find this +little two bar thing. + +I mean, if you want +to get more difficult + +you can find something +even in a tune like this. + +Something that's a +little more difficult + +and try that in all 12 keys. + +GREG HOPKINS: Let's +do bar 17, you know. + +[LAUGHTER] + +TIM RAY: Yeah, right. + +No, I'm not going to try it. + +GREG HOPKINS: +That's a-- basically + +it's this a B-flat lick. + +Yeah, that was my +idea, I want to go + +from B-flat to B-flat with some +kind of maybe 12 tone idea, + +I don't know what it is. + +TIM RAY: Yeah, so +that's, as Greg says, + +a lot of just sitting alone +at home work that's, I think, + +that's really helpful. + +All the great players did it. + +They all spent 10,000 hours. + +Is that the current idea? + +GREG HOPKINS: I +do the same thing. + +I do the same thing +with my scales. + +How do you practice your scales? + +Well, you do them in intervals. + +I mean, what is a melody? + +Let's define melody. + +This is a good place to do it. + +Let's have a real technical +definition of melody. + +Anybody, what is melody? + +First thing that +comes into your head. + +What's the melody? + +AUDIENCE: Whatever +you'd sing after you're + +done listening to it. + +GREG HOPKINS: Yeah, whatever +you hear-- what did you say? + +AUDIENCE: Whatever +you would sing + +after you were done +listening to it. + +GREG HOPKINS: Good, yeah, +whatever you'd sing. + +You're a melody player, violin, +you're all melody players. + +Yeah. + +You guys, too. + +What's melody to you? + +AUDIENCE: It's +kind of the song-- + +GREG HOPKINS: It's +the song, very good. + +AUDIENCE: [INAUDIBLE] + +GREG HOPKINS: Many +people say that. + +It's the main idea. + +It's the meaning. + +Technically, is this music? + +No, this is paper +with ink on it. + +This is graph paper. + +This is graph paper. + +Pitch goes up and down, +time goes that way. + +This is not music. + +It's only music when you +realize it, when you play it. + +So, the better you are +at creating intervals, + +the better you'll be +at melody playing. + +A melody is a +series of intervals + +in some kind of rhythm. + +So if I play-- that's the sixth. + +So six down, fourth +up, third up, + +minor sixth down, half step +up, half step, half step. + +That's what a melody is, +it's a series of intervals, + +that's all. + +In some kind of time, right? + +Every melody-- that's a +third, and then a fourth. + +Another third, second +second, major seventh. + +So, when we're playing +our scales, right? + +That's all the +same scale, I just + +played different intervals. + +I'll play the scale +in seconds, I'll + +play the scale in thirds, +fourths, fifths, sixths, + +and sevenths. + +Let's play G melodic minor. + +No, G-natural minor. + +Good, yeah, up and down. + +One note in the top. + +Go. + +Now play it in thirds. + +Now play it in fourths, slowly. + +Now in fifths. + +Nice. + +Sixth is really pretty. + +Sevenths is even more diverse, +a little obtuse, maybe? + +Yeah. + +Octaves. + +Ninths. + +I mean, you could +expand it even further. + +TIM RAY: Sure. + +GREG HOPKINS: You +do that, right? + +TIM RAY: Yeah. + +GREG HOPKINS: You've got +to learn your intervals. + +TIM RAY: Of course. + +Yeah, absolutely. + +GREG HOPKINS: And also +inherent in the scale + +is diatonic triads and +diatonic seventh chords. + +Do you do that in class? + +GUEST SPEAKER: We +haven't done that. + +Have you done that with Tom? + +GREG HOPKINS: Yeah, +play up all the triads + +in the G minor scale. + +TIM RAY: Yeah, well, right. + +If you're doing natural minor. + +GREG HOPKINS: Let's do that. + +It's just building blocks. + +This is the building blocks +of melody and harmony. + +TIM RAY: Yeah, that's true. + +GREG HOPKINS: And then +as you study each scale, + +each scale is different. + +Each scale has +characteristic notes + +that make it function +different than other scales. + +That's what makes +the scales different, + +is the different notes. + +And how the architecture +of the scale + +works and draws things together. + +So, I mean that's what we +study when we practice. + +I'll practice +scales and I'll try + +to really get the +meaning out of the scale. + +This scale, natural +minor, is-- Yeah, I + +mean there's certain things that +make that scale work, right? + +TIM RAY: Sure, absolutely. + +GREG HOPKINS: Flat sixth, right? + +TIM RAY: Yeah, yeah. + +Absolutely. + +GREG HOPKINS: So if I'm +playing a natural minor, + +I immediately know that the flat +sixth is a real strong note. + +Let's just play a natural-- +we'll play a natural minor just + +for a minute. + +TIM RAY: Sure. + +GREG HOPKINS: G, so it'll +be like C minor, right? + +Another chord? + +TIM RAY: Right, yeah. + +GREG HOPKINS: So one, +two, a one, two, three. + +Yeah. + +TIM RAY: Yeah, all right. + +GREG HOPKINS: So +you're using D seven? + +TIM RAY: Yeah, I used D seven. + +GREG HOPKINS: Oh, +you used D seven, OK. + +TIM RAY: Yeah, I threw that in. + +Which is not technically part-- + +GUEST SPEAKER: We did +this with [INAUDIBLE], + +and so you're already +talking [INAUDIBLE]. + +GREG HOPKINS: This +is aeolian mode. + +It's called the aeolian mode. + +Let's just play G minor C minor. + +TIM RAY: Yeah. + +GREG HOPKINS: One bar each. + +One two three four-- + +I think modes is a great way +to start learning harmony. + +TIM RAY: Absolutely, yeah. + +GREG HOPKINS: Because +there's only one note, + +really, that's really strong. + +So here were playing G minor +for a bar and C minor for a bar. + +G minor, C minor. + +What's the note that +changes the most? + +When you play the C minor +it's going to be the E-flat. + +The E-flat. + +So the G minor has +a D in it, right? + +In then you go to C minor. + +[SINGS NOTE] + +So that's the +meaning of aeolian. + +TIM RAY: Absolutely, yeah. + +GREG HOPKINS: You could +play E-flat major, + +would be a good +chord too, I think. + +Let's play a bar each, +G minor and C minor. + +Let's start over here, guitar. + +One, a two, a one, +two, three, four. + +Good. + +Yeah. + +Yeah, OK. + +Got the idea? + +Yeah, that's good. + +I mean that's really +good for your ear. + +Now I'm really working +on a small slice + +of harmonic information +that I could put to use. + +Now you played D seven before, +what scale would that be? + +TIM RAY: Yeah, right? + +So, D seven has got +what note in it-- + +GREG HOPKINS: What +note does D seven have? + +TIM RAY: --that doesn't +belong in the aeolian-- + +GREG HOPKINS: That's different. + +TIM RAY: Yeah, right. + +You played it, Chris. + +F-sharp, right? + +GREG HOPKINS: F-sharp. + +Yeah. + +So that's kind of +like G-- now we've + +got to learn G +harmonic minor scale. + +Which has that very interesting +augmented second interval. + +Gives it an exotic, Middle +Eastern or Detroit flavor. + +Let's play harmonic minor. + +One, two, three. + +Let's play the triads in +harmonic minor-- slowly. + +One, two-- Yeah. + +The three chord's very +interesting, augmented chord. + +And the four chord +is still minor. + +So it's similar to aeolian +but it has the much preferred + +leading tone, the F-sharp. + +TIM RAY: Yes, indeed. + +GREG HOPKINS: Just for fun, now +let's play G minor for a bar + +and D seven flat nine for a bar. + +What do you think? + +TIM RAY: Yeah. + +GREG HOPKINS: Flute first. + +Nah, I'll start. + +Two, a one, two, three-- +Yeah, yeah, nice. + +Yeah, and so on. + +It's another small +slice of harmony + +but it's different +than the first one. + +So you practice that and you +practice it, and then it sinks + +in your ear. + +Because this is nothing +but ear training. + +All this is just ear training +so you can pick your flavors. + +OK, I want this flavor, I +want that color, that mood, + +that sound. + +Then there's melodic minor. + +Yeah, because when +you play a minor key + +you don't just +play one scale, we + +mix four or five +minor scales together. + +And if I play a +certain note, he'll + +hear it and play the voicing +behind me, or whatever. + +TIM RAY: Exactly. + +That's where listening +comes into play. + +Listening to the +person you're with. + +GREG HOPKINS: When Wayne +Shorter was in the Army + +he used to spend a +month on one scale. + +He would practice the +key of D-flat for months. + +He'd play every tune +he knew in D-flat. + +He'd practice the scales, +he'd practice the chords, + +he'd play rhythm changes, +blues, everything in one key. + +And Coltrane did the same thing. + +All the guys that practiced. + +I have a tape of Clifford +Brown practicing the bridge + +to "Cherokee" for an hour. + +And you know he +did it every day. + +Played with his mute. + +TIM RAY: Cool. + +So I also wanted +to get back to-- + +and this great +information, certainly-- I + +wanted to get back the idea +of having you guys pair up + +a little bit. + +And maybe try it without me +doing the accompaniment, which + +of course is about listening, as +I was saying just a second ago, + +listening to who you're with. + +Without the accompaniment +it becomes-- + +what becomes more important? + +This is like as Greg +and I and Eugene + +were doing with +the song, where we + +were all kind of soloing +at the same time. + +That's what I want to try to +get you guys to do a little bit. + +And what aspect of +music becomes more + +important in that situation. + +Something we haven't really +talked about yet today. + +GREG HOPKINS: So let's have +flute, sax, and guitar. + +TIM RAY: What I was getting +at was rhythm, right? + +Again, getting back to the +idea that we're all time + +keepers, right. + +I mean, when you hear +somebody like Greg who + +is a great improviser, his +rhythmic ideas are very clear. + +His rhythmic ideas +are very clear, + +and if he does +something intentionally + +that's a little less +clear, he follows it up + +with something that's more clear +so that the people around him + +know where the beats are, right? + +So that's another thing that's +really important to work on + +and I know we did a little +thing with rhythm with Eugene + +last time. + +AUDIENCE: So are we doing +an accompaniment solo type + +thing or more like +a conversational? + +TIM RAY: I think we should try +doing like a conversational-- + +GREG HOPKINS: Conversation. + +So nobody's really +comping, you're + +all playing your own ideas. + +I'm leaving space for +other people's ideas. + +TIM RAY: Right. + +So what we'll do is +maybe have you guys play. + +You're all improvising again, +leaving space, conversing. + +I'll do a baseline for 12 +bars and then I'll drop + +and you guys keep going. + +OK? + +So this will be improv. + +We're not going +to do the melody, + +just starting right +with the improv. + +Feel free to throw in +some motivic stuff, some + +of the things Greg was talking +about in terms of the scales, + +obviously G minor scale can +figure prominently in this. + +OK, so here we go. + +Right at the top of the improv. + +One, a two, a one, two, three-- + +GREG HOPKINS: One more? + +One more. + +Not bad. + +That was good. + +TIM RAY: That was good. + +Everybody feel where +the time was, right? + +Felt pretty secure to me. + +And then listening, really nice. + +One of the motifs we +haven't touched on, + +which is the quarter +note triplets, right? + +Quarter note +triplets are tricky, + +because that's against +the feeling of duple. + +Against the feeling +of two and four, + +which is-- any +song in four four, + +most songs tend to +spend most of their time + +either quarter +notes, eight notes. + +Any kind of triplet feeling +is sort of against that. + +So when there's +not accompaniment, + +you have to be +really careful to-- + +I mean I'm not saying don't play +them, I think they're great-- + +but just be really careful to +articulate where your landing + +them. + +Because that's usually the thing +that gets rushed or dragged + +and that sometimes +can send you-- + +GREG HOPKINS: And sometimes if +somebody's playing quarter note + +triplets, maybe the other +person would play quarter notes + +against that. + +Just to be obstinate, or +to have that counterpoint + +so I can tell that +they're really triplets. + +I mean, sometimes you don't +want to use mimicry too much. + +If somebody plays an idea, don't +just play the same idea back. + +Play something different. + +If I say hello, you +don't say hello. + +Well, I guess you do. + +What's your name? + +What's your name? + +Yeah, you have to +have an answer. + +So let's do a flute, +guitar, and violin. + +TIM RAY: We'll do +the same thing. + +I'll start off with the +baseline and then I'll drop out. + +But you guys keep going. + +OK, here we go. + +One, a two, a one, +two, three, four-- + +GREG HOPKINS: Not +bad, yeah it was good. + +TIM RAY: OK, nice. + +So-- oh no, go ahead. + +GREG HOPKINS: Same as before, +nice use of the motifs. + +Sometimes I'll just +play the melody. + +And Tim and Eugene +will play around it, + +and sometimes Tim will +quote some of the melody. + +TIM RAY: Yeah, absolutely. + +A couple things to +just be careful of, + +I know you guys +are, to some degree, + +kind of hanging +on to the rhythm. + +I know, which is, of +course, what we all + +do in this situation. + +You're like, sometimes +you're kind of white + +knuckling the beats instead of +just kind of letting it flow. + +And I think sometimes +when that happens, + +you start to lose a +little bit of linear flow. + +I felt like there was a lot +of root improvisation based + +on the roots going on. + +GREG HOPKINS: It was +a little block style. + +TIM RAY: Yeah, right. + +And again, it's not to say +that if you did it again + +you might do something +entirely different. + +But it's just one thing +to be aware of, right? + +And this is one of these +situations where you try it + +again and you say, +OK I'm going to not + +focus on the root +so much I'm going + +to try to do more linear +stuff, more scales. + +Maybe focus on the third or the +fifth, or just, like I said, + +be a little bit more free +with what you're doing. + +So, again it's nice stuff. + +GREG HOPKINS: Let's +do flute and piano, + +and you get another chance. + +TIM RAY: All right. + +Same thing. + +One, two, a one, +two, three, four-- + +GREG HOPKINS: Bang! + +OK, you stopped before the end. + +We're still playing the fourth. + +We're still playing +12 bar forms, right? + +Did they stop before the end? + +TIM RAY: Yeah , we-- + +GREG HOPKINS: Or maybe it was +just really good use of space. + +TIM RAY: Yeah. + +It's either that or you +owe us three measures. + +I don't know. + +We'll come back and +collect next year. + +GREG HOPKINS: Let +me show you-- here's + +an interesting way to practice. + +This is going to be +a revolving trio. + +I'm going to start +with you three, OK. + +Then you're going to drop +out, you're going to join in, + +and then you're +going to drop out, + +then you're going to join in. + +Then you're going to-- +whatever three people. + +And no base line. + +A one, two, a one, +two, three, four-- + +OK. + +TIM RAY: Yeah, all right. + +GREG HOPKINS: To you? + +Yeah. + +It's a nice way to practice and +then you don't-- everyone's not + +jamming in your ear, and again +you're setting parameters. + +We're going to have three people +playing or two people playing. + +TIM RAY: Yeah. + +Yeah, you guys are +doing a great job. + +I mean, I can tell-- + +GREG HOPKINS: You're keeping the +form and your ideas are clear. + +TIM RAY: Very nice. + +And again, hearing some of +the motifs come into play, + +that's very cool. + +GREG HOPKINS: I'm thrilled. + +TIM RAY: Yeah, I-- + +GREG HOPKINS: [? Karagassian ?] +will be very happy. + +TIM RAY: I know we're +getting close to out of time. + +Are there any +questions about some + +of this stuff we've been +talking about, scales, modes? + +GREG HOPKINS: I need to +stress what Tim said before. + +Melodies and harmonies are fine, +but the most important thing + +in this music is rhythm. + +Rhythm. + +Rhythm. + +It's like location +in real estate. + +Rhythm. + +Rhythm. + +You could play any +note, it doesn't matter, + +if it's in the right time and +it swings, people will buy it. + +TIM RAY: That's true. + +GREG HOPKINS: It's +absolutely true. + +It's a rhythmic art form. + +Came from dancing. + +TIM RAY: Yeah, that's true. + +GREG HOPKINS: I do +an analogy my class. + +Let me just get to the +board right behind you + +for one second. + +Chalk, mighty chalk. + +Harmony. + +We study all this harmony. + +I'm going to give +it an H that big. + +But I'm a melody guy, so +melody is more important. + +But rhythm is-- and +actually it should + +go to the top of the building +to under the basement, + +and make an R out to +Mass Ave and back. + +TIM RAY: Very cool, thank you. + +That's-- I would +agree with the that. + +GREG HOPKINS: Rhythm is-- + +TIM RAY: So work on rhythm. + +GREG HOPKINS: Sometimes +I just play one note. + +TIM RAY: Yeah, I know. + +GREG HOPKINS: Let's play +a minimalistic chorus, + +just me and you. + +TIM RAY: OK. + +GREG HOPKINS: Two, a +one, two, three-- Yeah, + +so we left a lot of +space, but when we came in + +with the rhythms, they +were very strong that time. + +So sometimes I think I'm +playing like a melodic drummer. + +I want to lay that melody +down so people know right + +where it is. + +And sometimes I don't, +sometimes I'll float. + +TIM RAY: Right. + +And I think most of the +good players did that. + +They'd float for +awhile and then they'd + +lock it in with something +really specific. + +That's one of things I work +on with some of my students. + +Play a phrase, it +floats, and then play + +something that really locks in. + +So that you know the difference, +you can hear the difference, + +and you can feel the +difference in your hands + +as to what the different-- +whatever your instrument is. + +So you can feel the difference, +how it affects the music + +and how it affects +your improvisation. + +So, yeah that's +another great-- there's + +all these exercises, etudes, +whatever you want to call them, + +for improvisations +which are great to do. + +GREG HOPKINS: Transcribing +is really good, + +because you can't really +notate jazz rhythms. + +You can write the +notes down, but you + +can't notate how +they're playing them. + +So you've got to listen. + +And now copy Miles' +articulation, + +or Clifford Brown's +articulation, or whoever, + +Chet Baker. + +Because they would all +play a little differently, + +but-- it's all the tongue. + +It's all articulation. + +Because it's wind +instruments, I mean + +that's where a lot of +the language comes from. + +And piano. + +TIM RAY: But even with +piano or guitar, still, + +the articulation makes +all the difference. + +You could do a whole solo +just based on two notes. + +And be somewhat interesting. + +I mean, it's not going +to be super interesting, + +but just two notes with +articulation and strong + +rhythms, you can make +an interesting solo. + +Like I say, on any instrument. + +I think that's true. + +Drummers do it. + +That's how they solo. + +It's all about how +they hit the thing. + +They don't have 88 +keys to play with, + +they've just got four +drums and a couple symbols. + +GREG HOPKINS: And for +the wind instruments + +it's really just a matter +of slurring and tonguing. + +Some short notes, +some long notes, + +some slurred notes +in the middle. + +You've got to +tongue but it can't + +be-- you can't +tongue too hard or it + +sounds too much +like a classical. + +It's got to have the funkiness +and looseness of the swing. + +So yeah, working on your +articulation is very important. + +That's what we do, right? + +GUEST SPEAKER: +Unfortunately I think + +we have to wrap because +it's the end of the period. + +GREG HOPKINS: Is it +3 o'clock already? + +GUEST SPEAKER: It's 3:30. + +GREG HOPKINS: It's 3:30? + +I'm going to get a ticket. + +GUEST SPEAKER: So let's give +a round of applause for Greg. + +GREG HOPKINS: Thank you. + +Yeah, good play. + +TIM RAY: Yeah, nice play. + +GREG HOPKINS: And have no fear. + +Have no fear. + +Play whatever you want. + +And try and hear it. \ No newline at end of file diff --git a/QKXAd2PhZGY.txt b/QKXAd2PhZGY.txt new file mode 100644 index 0000000000000000000000000000000000000000..6340c92660f087528a37fba0c44358a59fd90788 --- /dev/null +++ b/QKXAd2PhZGY.txt @@ -0,0 +1,1128 @@ +align:start position:0% + +hi welcome back to recitation in lecture + + align:start position:0% +hi welcome back to recitation in lecture + + + align:start position:0% +hi welcome back to recitation in lecture +Professor jarrison was teaching you + + align:start position:0% +Professor jarrison was teaching you + + + align:start position:0% +Professor jarrison was teaching you +about lal's Rule and one thing that he + + align:start position:0% +about lal's Rule and one thing that he + + + align:start position:0% +about lal's Rule and one thing that he +mentioned several times was that when + + align:start position:0% +mentioned several times was that when + + + align:start position:0% +mentioned several times was that when +you have when you apply lal's rule it's + + align:start position:0% +you have when you apply lal's rule it's + + + align:start position:0% +you have when you apply lal's rule it's +really important that the second limit + + align:start position:0% +really important that the second limit + + + align:start position:0% +really important that the second limit +exists in order for lal's rule to be + + align:start position:0% +exists in order for lal's rule to be + + + align:start position:0% +exists in order for lal's rule to be +true in order for the first limit to + + align:start position:0% +true in order for the first limit to + + + align:start position:0% +true in order for the first limit to +equal the second limit so I have a uh + + align:start position:0% +equal the second limit so I have a uh + + + align:start position:0% +equal the second limit so I have a uh +but he didn't he didn't give you any + + align:start position:0% +but he didn't he didn't give you any + + + align:start position:0% +but he didn't he didn't give you any +examples of of uh what can go wrong um + + align:start position:0% +examples of of uh what can go wrong um + + + align:start position:0% +examples of of uh what can go wrong um +so I have here a limit for you to to + + align:start position:0% +so I have here a limit for you to to + + + align:start position:0% +so I have here a limit for you to to +work on um so what I'd like you to do is + + align:start position:0% +work on um so what I'd like you to do is + + + align:start position:0% +work on um so what I'd like you to do is +is try lall's rule see what happens and + + align:start position:0% +is try lall's rule see what happens and + + + align:start position:0% +is try lall's rule see what happens and +then try to solve it a different way not + + align:start position:0% +then try to solve it a different way not + + + align:start position:0% +then try to solve it a different way not +using lyall's rule so why don't you + + align:start position:0% +using lyall's rule so why don't you + + + align:start position:0% +using lyall's rule so why don't you +pause the video uh spend a couple + + align:start position:0% +pause the video uh spend a couple + + + align:start position:0% +pause the video uh spend a couple +minutes working on that come back and we + + align:start position:0% +minutes working on that come back and we + + + align:start position:0% +minutes working on that come back and we +can work on it + + align:start position:0% + + + + align:start position:0% + +together welcome back hopefully you had + + align:start position:0% +together welcome back hopefully you had + + + align:start position:0% +together welcome back hopefully you had +some fun working on this limit Let's uh + + align:start position:0% +some fun working on this limit Let's uh + + + align:start position:0% +some fun working on this limit Let's uh +let's go through it and and see what + + align:start position:0% +let's go through it and and see what + + + align:start position:0% +let's go through it and and see what +happens when we when we try to apply + + align:start position:0% +happens when we when we try to apply + + + align:start position:0% +happens when we when we try to apply +lal's rule to it so the first thing to + + align:start position:0% +lal's rule to it so the first thing to + + + align:start position:0% +lal's rule to it so the first thing to +notice is that as X goes to Infinity uh + + align:start position:0% +notice is that as X goes to Infinity uh + + + align:start position:0% +notice is that as X goes to Infinity uh +X plus cosine X well cosine X is is + + align:start position:0% +X plus cosine X well cosine X is is + + + align:start position:0% +X plus cosine X well cosine X is is +small you know between minus one and 1 x + + align:start position:0% +small you know between minus one and 1 x + + + align:start position:0% +small you know between minus one and 1 x +is going to Infinity so the top is going + + align:start position:0% +is going to Infinity so the top is going + + + align:start position:0% +is going to Infinity so the top is going +to infinity and the bottom is going to + + align:start position:0% +to infinity and the bottom is going to + + + align:start position:0% +to infinity and the bottom is going to +Infinity so this is an Infinity over + + align:start position:0% +Infinity so this is an Infinity over + + + align:start position:0% +Infinity so this is an Infinity over +infinity in determinate form so it is a + + align:start position:0% +infinity in determinate form so it is a + + + align:start position:0% +infinity in determinate form so it is a +a context in which we can try to apply + + align:start position:0% +a context in which we can try to apply + + + align:start position:0% +a context in which we can try to apply +lal's rules so that's that's fine it's + + align:start position:0% +lal's rules so that's that's fine it's + + + align:start position:0% +lal's rules so that's that's fine it's +it's an indeterminate ratio we can we + + align:start position:0% +it's an indeterminate ratio we can we + + + align:start position:0% +it's an indeterminate ratio we can we +can look at applying lal's rule so let's + + align:start position:0% +can look at applying lal's rule so let's + + + align:start position:0% +can look at applying lal's rule so let's +let's try to do that so lal's rule says + + align:start position:0% +let's try to do that so lal's rule says + + + align:start position:0% +let's try to do that so lal's rule says +that the limit as X goes to Infinity of + + align:start position:0% +that the limit as X goes to Infinity of + + + align:start position:0% +that the limit as X goes to Infinity of +our expression x + cosine x / X is equal + + align:start position:0% +our expression x + cosine x / X is equal + + + align:start position:0% +our expression x + cosine x / X is equal +and I'm going to put a little question + + align:start position:0% +and I'm going to put a little question + + + align:start position:0% +and I'm going to put a little question +mark here because what lal's rule says + + align:start position:0% +mark here because what lal's rule says + + + align:start position:0% +mark here because what lal's rule says +is that it's equal provided it's equal + + align:start position:0% +is that it's equal provided it's equal + + + align:start position:0% +is that it's equal provided it's equal +to what I'm going to write over here + + align:start position:0% +to what I'm going to write over here + + + align:start position:0% +to what I'm going to write over here +provided that the second limit exists so + + align:start position:0% +provided that the second limit exists so + + + align:start position:0% +provided that the second limit exists so +what goes over here well it's the limit + + align:start position:0% +what goes over here well it's the limit + + + align:start position:0% +what goes over here well it's the limit +as X goes to the same place as X go to + + align:start position:0% +as X goes to the same place as X go to + + + align:start position:0% +as X goes to the same place as X go to +Infinity of the the ratio of the + + align:start position:0% +Infinity of the the ratio of the + + + align:start position:0% +Infinity of the the ratio of the +derivative so the derivative of the top + + align:start position:0% +derivative so the derivative of the top + + + align:start position:0% +derivative so the derivative of the top +divided by the derivative of the bottom + + align:start position:0% +divided by the derivative of the bottom + + + align:start position:0% +divided by the derivative of the bottom +so in this case that's + + align:start position:0% +so in this case that's + + + align:start position:0% +so in this case that's + + align:start position:0% + + + align:start position:0% +minus sin x is the derivative of the top + + align:start position:0% +minus sin x is the derivative of the top + + + align:start position:0% +minus sin x is the derivative of the top +and 1 is the derivative of the + + align:start position:0% +and 1 is the derivative of the + + + align:start position:0% +and 1 is the derivative of the +bottom okay now let's look at this limit + + align:start position:0% +bottom okay now let's look at this limit + + + align:start position:0% +bottom okay now let's look at this limit +what happens well okay the over one part + + align:start position:0% +what happens well okay the over one part + + + align:start position:0% +what happens well okay the over one part +is irrelevant the the one minus part + + align:start position:0% +is irrelevant the the one minus part + + + align:start position:0% +is irrelevant the the one minus part +okay who cares the the only thing that's + + align:start position:0% +okay who cares the the only thing that's + + + align:start position:0% +okay who cares the the only thing that's +changing in this limit is the + + align:start position:0% +changing in this limit is the + + + align:start position:0% +changing in this limit is the +sinx so as X goes to Infinity what this + + align:start position:0% +sinx so as X goes to Infinity what this + + + align:start position:0% +sinx so as X goes to Infinity what this +does is it is it oscillates just like + + align:start position:0% +does is it is it oscillates just like + + + align:start position:0% +does is it is it oscillates just like +sinx does I mean it's it's offset and + + align:start position:0% +sinx does I mean it's it's offset and + + + align:start position:0% +sinx does I mean it's it's offset and +flipped upside down because of this one + + align:start position:0% +flipped upside down because of this one + + + align:start position:0% +flipped upside down because of this one +minus but um so in particular it you + + align:start position:0% +minus but um so in particular it you + + + align:start position:0% +minus but um so in particular it you +know sometimes it's near one sometimes + + align:start position:0% +know sometimes it's near one sometimes + + + align:start position:0% +know sometimes it's near one sometimes +it's near negative 1 sometimes it's near + + align:start position:0% +it's near negative 1 sometimes it's near + + + align:start position:0% +it's near negative 1 sometimes it's near +zero and it and it oscillates back and + + align:start position:0% +zero and it and it oscillates back and + + + align:start position:0% +zero and it and it oscillates back and +forth in between um so in particular + + align:start position:0% +forth in between um so in particular + + + align:start position:0% +forth in between um so in particular +because it's oscillating it's not + + align:start position:0% +because it's oscillating it's not + + + align:start position:0% +because it's oscillating it's not +approaching any value so this this limit + + align:start position:0% +approaching any value so this this limit + + + align:start position:0% +approaching any value so this this limit +doesn't exist uh it's not equal to any + + align:start position:0% +doesn't exist uh it's not equal to any + + + align:start position:0% +doesn't exist uh it's not equal to any +real number it's not equal to Infinity + + align:start position:0% +real number it's not equal to Infinity + + + align:start position:0% +real number it's not equal to Infinity +it's not equal to minus infinity it does + + align:start position:0% +it's not equal to minus infinity it does + + + align:start position:0% +it's not equal to minus infinity it does +not exist + + align:start position:0% + + + + align:start position:0% + +okay so the the statement of lal's + + align:start position:0% +okay so the the statement of lal's + + + align:start position:0% +okay so the the statement of lal's +theorem says that thise equality is + + align:start position:0% +theorem says that thise equality is + + + align:start position:0% +theorem says that thise equality is +really wrong okay what it what it means + + align:start position:0% +really wrong okay what it what it means + + + align:start position:0% +really wrong okay what it what it means +is that low rule tells you nothing you + + align:start position:0% +is that low rule tells you nothing you + + + align:start position:0% +is that low rule tells you nothing you +don't learn anything here so if we want + + align:start position:0% +don't learn anything here so if we want + + + align:start position:0% +don't learn anything here so if we want +to compute this first limit we can't use + + align:start position:0% +to compute this first limit we can't use + + + align:start position:0% +to compute this first limit we can't use +lal's rule we have to come up with some + + align:start position:0% +lal's rule we have to come up with some + + + align:start position:0% +lal's rule we have to come up with some +better way to do it okay um so so that's + + align:start position:0% +better way to do it okay um so so that's + + + align:start position:0% +better way to do it okay um so so that's +what's going wrong now let's see about + + align:start position:0% +what's going wrong now let's see about + + + align:start position:0% +what's going wrong now let's see about +doing this even though we don't have + + align:start position:0% +doing this even though we don't have + + + align:start position:0% +doing this even though we don't have +this tool so if we try and and solve + + align:start position:0% +this tool so if we try and and solve + + + align:start position:0% +this tool so if we try and and solve +this limit without lal's rule so we want + + align:start position:0% +this limit without lal's rule so we want + + + align:start position:0% +this limit without lal's rule so we want +to look at the limit as X goes to + + align:start position:0% +to look at the limit as X goes to + + + align:start position:0% +to look at the limit as X goes to +Infinity of X plus cosine x / X um well + + align:start position:0% +Infinity of X plus cosine x / X um well + + + align:start position:0% +Infinity of X plus cosine x / X um well +think about what's important in this + + align:start position:0% +think about what's important in this + + + align:start position:0% +think about what's important in this +limit as X is getting big well X is + + align:start position:0% +limit as X is getting big well X is + + + align:start position:0% +limit as X is getting big well X is +getting big and X is getting big and + + align:start position:0% +getting big and X is getting big and + + + align:start position:0% +getting big and X is getting big and +what's cosine X doing well cosine X is + + align:start position:0% +what's cosine X doing well cosine X is + + + align:start position:0% +what's cosine X doing well cosine X is +behaving like a constant but but wigger + + align:start position:0% +behaving like a constant but but wigger + + + align:start position:0% +behaving like a constant but but wigger +right we could we could say so cosine X + + align:start position:0% +right we could we could say so cosine X + + + align:start position:0% +right we could we could say so cosine X +is is always between minus one and one + + align:start position:0% +is is always between minus one and one + + + align:start position:0% +is is always between minus one and one +but you know it's oscillating but it's + + align:start position:0% +but you know it's oscillating but it's + + + align:start position:0% +but you know it's oscillating but it's +in some bounded interval there um + + align:start position:0% +in some bounded interval there um + + + align:start position:0% +in some bounded interval there um +whereas x and x + + align:start position:0% +whereas x and x + + + align:start position:0% +whereas x and x +are both going to Infinity at exactly + + align:start position:0% +are both going to Infinity at exactly + + + align:start position:0% +are both going to Infinity at exactly +the same speed + + align:start position:0% +the same speed + + + align:start position:0% +the same speed +so this suggests a manipulation that + + align:start position:0% +so this suggests a manipulation that + + + align:start position:0% +so this suggests a manipulation that +that sort of allows us to quantify that + + align:start position:0% +that sort of allows us to quantify that + + + align:start position:0% +that sort of allows us to quantify that +explicitly and so one thing that we can + + align:start position:0% +explicitly and so one thing that we can + + + align:start position:0% +explicitly and so one thing that we can +do is we can divide top and bottom of + + align:start position:0% +do is we can divide top and bottom of + + + align:start position:0% +do is we can divide top and bottom of +this limit by X um so if we do that or + + align:start position:0% +this limit by X um so if we do that or + + + align:start position:0% +this limit by X um so if we do that or +or equivalently we can just divide this + + align:start position:0% +or equivalently we can just divide this + + + align:start position:0% +or equivalently we can just divide this +x into the into the fraction above split + + align:start position:0% +x into the into the fraction above split + + + align:start position:0% +x into the into the fraction above split +it into two fractions + + align:start position:0% +it into two fractions + + + align:start position:0% +it into two fractions +so we have I'm just going to rewrite it + + align:start position:0% +so we have I'm just going to rewrite it + + + align:start position:0% +so we have I'm just going to rewrite it +one more time the limit as X goes to to + + align:start position:0% +one more time the limit as X goes to to + + + align:start position:0% +one more time the limit as X goes to to +Infinity of x + cosine x / X is equal to + + align:start position:0% +Infinity of x + cosine x / X is equal to + + + align:start position:0% +Infinity of x + cosine x / X is equal to +the Limit as X goes to Infinity of 1 + + align:start position:0% +the Limit as X goes to Infinity of 1 + + + align:start position:0% +the Limit as X goes to Infinity of 1 ++ cosine + + align:start position:0% ++ cosine + + + align:start position:0% ++ cosine +X + + align:start position:0% +X + + + align:start position:0% +X +overx all right so what's happening here + + align:start position:0% +overx all right so what's happening here + + + align:start position:0% +overx all right so what's happening here +well all I've done is I've divided that + + align:start position:0% +well all I've done is I've divided that + + + align:start position:0% +well all I've done is I've divided that +X in and now you see that this one that + + align:start position:0% +X in and now you see that this one that + + + align:start position:0% +X in and now you see that this one that +was from the X overx so that's a + + align:start position:0% +was from the X overx so that's a + + + align:start position:0% +was from the X overx so that's a +constant that's going to one and as X + + align:start position:0% +constant that's going to one and as X + + + align:start position:0% +constant that's going to one and as X +goes to Infinity cosine X again is we + + align:start position:0% +goes to Infinity cosine X again is we + + + align:start position:0% +goes to Infinity cosine X again is we +can think of it like a constant but + + align:start position:0% +can think of it like a constant but + + + align:start position:0% +can think of it like a constant but +wigger X is going to Infinity so cosine + + align:start position:0% +wigger X is going to Infinity so cosine + + + align:start position:0% +wigger X is going to Infinity so cosine +XX is going to zero as X goes to + + align:start position:0% +XX is going to zero as X goes to + + + align:start position:0% +XX is going to zero as X goes to +Infinity so at so I guess I wouldn't + + align:start position:0% +Infinity so at so I guess I wouldn't + + + align:start position:0% +Infinity so at so I guess I wouldn't +call this plugging in but it's you know + + align:start position:0% +call this plugging in but it's you know + + + align:start position:0% +call this plugging in but it's you know +sort of just like plugging in so this + + align:start position:0% +sort of just like plugging in so this + + + align:start position:0% +sort of just like plugging in so this +part is going to zero so we're left with + + align:start position:0% +part is going to zero so we're left with + + + align:start position:0% +part is going to zero so we're left with +just + + align:start position:0% + + + + align:start position:0% + +one okay so we can evaluate this limit + + align:start position:0% +one okay so we can evaluate this limit + + + align:start position:0% +one okay so we can evaluate this limit +fairly easily just took a couple steps + + align:start position:0% +fairly easily just took a couple steps + + + align:start position:0% +fairly easily just took a couple steps +but we can't evaluate it with lal's rule + + align:start position:0% +but we can't evaluate it with lal's rule + + + align:start position:0% +but we can't evaluate it with lal's rule +so this is why you have that that that + + align:start position:0% +so this is why you have that that that + + + align:start position:0% +so this is why you have that that that +extra thing in in the statement of the + + align:start position:0% +extra thing in in the statement of the + + + align:start position:0% +extra thing in in the statement of the +theorem that Professor Jaron kept saying + + align:start position:0% +theorem that Professor Jaron kept saying + + + align:start position:0% +theorem that Professor Jaron kept saying +and and that I'll say every time I use + + align:start position:0% +and and that I'll say every time I use + + + align:start position:0% +and and that I'll say every time I use +it which is lal's Rule says that the + + align:start position:0% +it which is lal's Rule says that the + + + align:start position:0% +it which is lal's Rule says that the +limit of the ratio is equal to the limit + + align:start position:0% +limit of the ratio is equal to the limit + + + align:start position:0% +limit of the ratio is equal to the limit +of the ratio of the derivatives provided + + align:start position:0% +of the ratio of the derivatives provided + + + align:start position:0% +of the ratio of the derivatives provided +the second limit exists okay so here's + + align:start position:0% +the second limit exists okay so here's + + + align:start position:0% +the second limit exists okay so here's +an example where the second limit didn't + + align:start position:0% +an example where the second limit didn't + + + align:start position:0% +an example where the second limit didn't +exist and so we can't say that the two + + align:start position:0% +exist and so we can't say that the two + + + align:start position:0% +exist and so we can't say that the two +are actually equal to each other and we + + align:start position:0% +are actually equal to each other and we + + + align:start position:0% +are actually equal to each other and we +need some other tools to evaluate the + + align:start position:0% +need some other tools to evaluate the + + + align:start position:0% +need some other tools to evaluate the +limit in question so I'll end there \ No newline at end of file diff --git a/QuZL5IKpO_U.txt b/QuZL5IKpO_U.txt new file mode 100644 index 0000000000000000000000000000000000000000..dcd4408f4251102719f2c15eae65e6d740613967 --- /dev/null +++ b/QuZL5IKpO_U.txt @@ -0,0 +1,6171 @@ +align:start position:0% + +okay this is quiz review day the quiz + + align:start position:0% +okay this is quiz review day the quiz + + + align:start position:0% +okay this is quiz review day the quiz +coming up on Wednesday will be for this + + align:start position:0% +coming up on Wednesday will be for this + + + align:start position:0% +coming up on Wednesday will be for this +lecture the quiz will be this our one + + align:start position:0% +lecture the quiz will be this our one + + + align:start position:0% +lecture the quiz will be this our one +o'clock Wednesday in Walker + + align:start position:0% +o'clock Wednesday in Walker + + + align:start position:0% +o'clock Wednesday in Walker +top floor of Walker closed book all + + align:start position:0% +top floor of Walker closed book all + + + align:start position:0% +top floor of Walker closed book all +normal I wrote down what we've covered + + align:start position:0% +normal I wrote down what we've covered + + + align:start position:0% +normal I wrote down what we've covered +in this second part of the course and + + align:start position:0% +in this second part of the course and + + + align:start position:0% +in this second part of the course and +actually I've impressed as I write it so + + align:start position:0% +actually I've impressed as I write it so + + + align:start position:0% +actually I've impressed as I write it so +that's chapter 4 on orthogonality and + + align:start position:0% +that's chapter 4 on orthogonality and + + + align:start position:0% +that's chapter 4 on orthogonality and +you're remembering these what this is + + align:start position:0% +you're remembering these what this is + + + align:start position:0% +you're remembering these what this is +suggesting these are those columns are + + align:start position:0% +suggesting these are those columns are + + + align:start position:0% +suggesting these are those columns are +orthonormal vectors and then we call + + align:start position:0% +orthonormal vectors and then we call + + + align:start position:0% +orthonormal vectors and then we call +that matrix Q and the what's the key how + + align:start position:0% +that matrix Q and the what's the key how + + + align:start position:0% +that matrix Q and the what's the key how +do we state the fact that those those + + align:start position:0% +do we state the fact that those those + + + align:start position:0% +do we state the fact that those those +columns are orthonormal in terms of Q it + + align:start position:0% +columns are orthonormal in terms of Q it + + + align:start position:0% +columns are orthonormal in terms of Q it +means that Q transpose Q is the identity + + align:start position:0% +means that Q transpose Q is the identity + + + align:start position:0% +means that Q transpose Q is the identity +so that's the matrix statement of the of + + align:start position:0% +so that's the matrix statement of the of + + + align:start position:0% +so that's the matrix statement of the of +the property that the columns are + + align:start position:0% +the property that the columns are + + + align:start position:0% +the property that the columns are +orthonormal the dot products are either + + align:start position:0% +orthonormal the dot products are either + + + align:start position:0% +orthonormal the dot products are either +1 or 0 and then we computed the + + align:start position:0% +1 or 0 and then we computed the + + + align:start position:0% +1 or 0 and then we computed the +projections onto lines and onto + + align:start position:0% +projections onto lines and onto + + + align:start position:0% +projections onto lines and onto +subspaces and we use that to solve + + align:start position:0% +subspaces and we use that to solve + + + align:start position:0% +subspaces and we use that to solve +problems ax equal B in in the least + + align:start position:0% +problems ax equal B in in the least + + + align:start position:0% +problems ax equal B in in the least +square sense when there was no solution + + align:start position:0% +square sense when there was no solution + + + align:start position:0% +square sense when there was no solution +we found the best solution and then + + align:start position:0% +we found the best solution and then + + + align:start position:0% +we found the best solution and then +finally this gram-schmidt idea which + + align:start position:0% +finally this gram-schmidt idea which + + + align:start position:0% +finally this gram-schmidt idea which +takes independent vectors and lines them + + align:start position:0% +takes independent vectors and lines them + + + align:start position:0% +takes independent vectors and lines them +up takes subtracts off the projections + + align:start position:0% +up takes subtracts off the projections + + + align:start position:0% +up takes subtracts off the projections +of the part you've already done so that + + align:start position:0% +of the part you've already done so that + + + align:start position:0% +of the part you've already done so that +the new part is orthogonal and so it + + align:start position:0% +the new part is orthogonal and so it + + + align:start position:0% +the new part is orthogonal and so it +takes a basis to an orthonormal basis + + align:start position:0% +takes a basis to an orthonormal basis + + + align:start position:0% +takes a basis to an orthonormal basis +and you those calculations involve + + align:start position:0% +and you those calculations involve + + + align:start position:0% +and you those calculations involve +square roots a lot because you're making + + align:start position:0% +square roots a lot because you're making + + + align:start position:0% +square roots a lot because you're making +things unit vectors but you should know + + align:start position:0% +things unit vectors but you should know + + + align:start position:0% +things unit vectors but you should know +that step + + align:start position:0% +that step + + + align:start position:0% +that step +okay four determinants the three big the + + align:start position:0% +okay four determinants the three big the + + + align:start position:0% +okay four determinants the three big the +big picture is the properties of the + + align:start position:0% +big picture is the properties of the + + + align:start position:0% +big picture is the properties of the +determinants one two three diff + + align:start position:0% +determinants one two three diff + + + align:start position:0% +determinants one two three diff +properties one two and three that define + + align:start position:0% +properties one two and three that define + + + align:start position:0% +properties one two and three that define +the determinants and then four five six + + align:start position:0% +the determinants and then four five six + + + align:start position:0% +the determinants and then four five six +through ten were consequences in the big + + align:start position:0% +through ten were consequences in the big + + + align:start position:0% +through ten were consequences in the big +formula that has n factorial terms half + + align:start position:0% +formula that has n factorial terms half + + + align:start position:0% +formula that has n factorial terms half +of them have plus signs and half minus + + align:start position:0% +of them have plus signs and half minus + + + align:start position:0% +of them have plus signs and half minus +signs and then the cofactor formula so + + align:start position:0% +signs and then the cofactor formula so + + + align:start position:0% +signs and then the cofactor formula so +and which led us to a formula for the + + align:start position:0% +and which led us to a formula for the + + + align:start position:0% +and which led us to a formula for the +inverse and finally just so you know + + align:start position:0% +inverse and finally just so you know + + + align:start position:0% +inverse and finally just so you know +what's covered in from Chapter three + + align:start position:0% +what's covered in from Chapter three + + + align:start position:0% +what's covered in from Chapter three +it's section six point one and two so + + align:start position:0% +it's section six point one and two so + + + align:start position:0% +it's section six point one and two so +that's the basic idea of eigenvalues and + + align:start position:0% +that's the basic idea of eigenvalues and + + + align:start position:0% +that's the basic idea of eigenvalues and +eigenvectors the equation for the + + align:start position:0% +eigenvectors the equation for the + + + align:start position:0% +eigenvectors the equation for the +eigenvalues the mechanical step this is + + align:start position:0% +eigenvalues the mechanical step this is + + + align:start position:0% +eigenvalues the mechanical step this is +really ax equal lambda X for all n + + align:start position:0% +really ax equal lambda X for all n + + + align:start position:0% +really ax equal lambda X for all n +eigenvectors at once if we have n + + align:start position:0% +eigenvectors at once if we have n + + + align:start position:0% +eigenvectors at once if we have n +independent eigenvectors and then using + + align:start position:0% +independent eigenvectors and then using + + + align:start position:0% +independent eigenvectors and then using +that to compute powers of a matrix so + + align:start position:0% +that to compute powers of a matrix so + + + align:start position:0% +that to compute powers of a matrix so +you notice the differential equations + + align:start position:0% +you notice the differential equations + + + align:start position:0% +you notice the differential equations +not on this list because that's six + + align:start position:0% +not on this list because that's six + + + align:start position:0% +not on this list because that's six +point three that that's for the third + + align:start position:0% +point three that that's for the third + + + align:start position:0% +point three that that's for the third +quiz okay so like what i usually do for + + align:start position:0% +quiz okay so like what i usually do for + + + align:start position:0% +quiz okay so like what i usually do for +review is to take an old exam and just + + align:start position:0% +review is to take an old exam and just + + + align:start position:0% +review is to take an old exam and just +try to pick out questions that are + + align:start position:0% +try to pick out questions that are + + + align:start position:0% +try to pick out questions that are +significant and write them quickly on + + align:start position:0% +significant and write them quickly on + + + align:start position:0% +significant and write them quickly on +the board shall I shall I proceed that + + align:start position:0% +the board shall I shall I proceed that + + + align:start position:0% +the board shall I shall I proceed that +way again this this exam is really old + + align:start position:0% + + + + align:start position:0% + +November 19 1984 so that was before the + + align:start position:0% +November 19 1984 so that was before the + + + align:start position:0% +November 19 1984 so that was before the +web existed so not only where the + + align:start position:0% +web existed so not only where the + + + align:start position:0% +web existed so not only where the +lectures are not on the web + + align:start position:0% + + + + align:start position:0% + +nobody even had a web page my god okay + + align:start position:0% +nobody even had a web page my god okay + + + align:start position:0% +nobody even had a web page my god okay +so can I nevertheless linear algebra was + + align:start position:0% +so can I nevertheless linear algebra was + + + align:start position:0% +so can I nevertheless linear algebra was +still as great as ever + + align:start position:0% +still as great as ever + + + align:start position:0% +still as great as ever +so may I and that wasn't meant to be a + + align:start position:0% +so may I and that wasn't meant to be a + + + align:start position:0% +so may I and that wasn't meant to be a +joke okay all right so let me just take + + align:start position:0% +joke okay all right so let me just take + + + align:start position:0% +joke okay all right so let me just take +these questions as they come all right + + align:start position:0% + + + + align:start position:0% + +okay so the first questions about + + align:start position:0% +okay so the first questions about + + + align:start position:0% +okay so the first questions about +projections it says we're given the line + + align:start position:0% +projections it says we're given the line + + + align:start position:0% +projections it says we're given the line +the vector a is the vector 2 1 2 and I + + align:start position:0% +the vector a is the vector 2 1 2 and I + + + align:start position:0% +the vector a is the vector 2 1 2 and I +want to find the projection matrix P + + align:start position:0% +want to find the projection matrix P + + + align:start position:0% +want to find the projection matrix P +that projects onto the line through a so + + align:start position:0% +that projects onto the line through a so + + + align:start position:0% +that projects onto the line through a so +my picture is well I'm in three + + align:start position:0% +my picture is well I'm in three + + + align:start position:0% +my picture is well I'm in three +dimensions of course so there's a vector + + align:start position:0% +dimensions of course so there's a vector + + + align:start position:0% +dimensions of course so there's a vector +- there's the vector a 2 1 2 let me draw + + align:start position:0% +- there's the vector a 2 1 2 let me draw + + + align:start position:0% +- there's the vector a 2 1 2 let me draw +the whole line through it and I want to + + align:start position:0% +the whole line through it and I want to + + + align:start position:0% +the whole line through it and I want to +project any vector B onto that line and + + align:start position:0% +project any vector B onto that line and + + + align:start position:0% +project any vector B onto that line and +I'm looking for the projection matrix so + + align:start position:0% +I'm looking for the projection matrix so + + + align:start position:0% +I'm looking for the projection matrix so +so this the projection matrix is the + + align:start position:0% +so this the projection matrix is the + + + align:start position:0% +so this the projection matrix is the +matrix that I multiply B by to get here + + align:start position:0% +matrix that I multiply B by to get here + + + align:start position:0% +matrix that I multiply B by to get here +and I guess this first part this is just + + align:start position:0% +and I guess this first part this is just + + + align:start position:0% +and I guess this first part this is just +part one a I'm really asking you the + + align:start position:0% +part one a I'm really asking you the + + + align:start position:0% +part one a I'm really asking you the +quick way to answer to find P is just to + + align:start position:0% +quick way to answer to find P is just to + + + align:start position:0% +quick way to answer to find P is just to +remember what the formula is and and + + align:start position:0% +remember what the formula is and and + + + align:start position:0% +remember what the formula is and and +we're in we're projecting onto a line so + + align:start position:0% +we're in we're projecting onto a line so + + + align:start position:0% +we're in we're projecting onto a line so +our formula our usual formula is a a + + align:start position:0% +our formula our usual formula is a a + + + align:start position:0% +our formula our usual formula is a a +transpose a inverse a transpose + + align:start position:0% +transpose a inverse a transpose + + + align:start position:0% +transpose a inverse a transpose +but now a is just a column one column + + align:start position:0% +but now a is just a column one column + + + align:start position:0% +but now a is just a column one column +matrix so it'll be just a so I'll just + + align:start position:0% +matrix so it'll be just a so I'll just + + + align:start position:0% +matrix so it'll be just a so I'll just +call it little a little a transpose and + + align:start position:0% +call it little a little a transpose and + + + align:start position:0% +call it little a little a transpose and +this is just a number now one by one so + + align:start position:0% +this is just a number now one by one so + + + align:start position:0% +this is just a number now one by one so +I can put it in the denominator so + + align:start position:0% +I can put it in the denominator so + + + align:start position:0% +I can put it in the denominator so +there's our that's really what we want + + align:start position:0% +there's our that's really what we want + + + align:start position:0% +there's our that's really what we want +to remember and using that - one - what + + align:start position:0% +to remember and using that - one - what + + + align:start position:0% +to remember and using that - one - what +will I get + + align:start position:0% +will I get + + + align:start position:0% +will I get +I'm dividing by what's the length + + align:start position:0% +I'm dividing by what's the length + + + align:start position:0% +I'm dividing by what's the length +squared of that vector so what's a + + align:start position:0% +squared of that vector so what's a + + + align:start position:0% +squared of that vector so what's a +transpose a looks like 9 and what's the + + align:start position:0% +transpose a looks like 9 and what's the + + + align:start position:0% +transpose a looks like 9 and what's the +matrix well I'm doing 2 1 2 against 2 1 + + align:start position:0% +matrix well I'm doing 2 1 2 against 2 1 + + + align:start position:0% +matrix well I'm doing 2 1 2 against 2 1 +2 so it's 1/9 + + align:start position:0% +2 so it's 1/9 + + + align:start position:0% +2 so it's 1/9 +of this matrix 4 2 4 2 1 2 4 2 4 now the + + align:start position:0% +of this matrix 4 2 4 2 1 2 4 2 4 now the + + + align:start position:0% +of this matrix 4 2 4 2 1 2 4 2 4 now the +next part asked about eigenvalues so you + + align:start position:0% +next part asked about eigenvalues so you + + + align:start position:0% +next part asked about eigenvalues so you +see where since we're learning we know a + + align:start position:0% +see where since we're learning we know a + + + align:start position:0% +see where since we're learning we know a +lot more + + align:start position:0% +lot more + + + align:start position:0% +lot more +now we can make connections between + + align:start position:0% +now we can make connections between + + + align:start position:0% +now we can make connections between +these chapters so what's the eigenvector + + align:start position:0% +these chapters so what's the eigenvector + + + align:start position:0% +these chapters so what's the eigenvector +what are the eigenvalues of p I could + + align:start position:0% +what are the eigenvalues of p I could + + + align:start position:0% +what are the eigenvalues of p I could +ask what's the rank of P what's the rank + + align:start position:0% +ask what's the rank of P what's the rank + + + align:start position:0% +ask what's the rank of P what's the rank +of that matrix the one rank is one + + align:start position:0% +of that matrix the one rank is one + + + align:start position:0% +of that matrix the one rank is one +what's the column space if I apply P to + + align:start position:0% +what's the column space if I apply P to + + + align:start position:0% +what's the column space if I apply P to +all vectors then I fill up the column + + align:start position:0% +all vectors then I fill up the column + + + align:start position:0% +all vectors then I fill up the column +space its combinations of the column so + + align:start position:0% +space its combinations of the column so + + + align:start position:0% +space its combinations of the column so +what's the column space well it's just + + align:start position:0% +what's the column space well it's just + + + align:start position:0% +what's the column space well it's just +this line the column space is the line + + align:start position:0% +this line the column space is the line + + + align:start position:0% +this line the column space is the line +through two one two and now what's the + + align:start position:0% +through two one two and now what's the + + + align:start position:0% +through two one two and now what's the +eigenvalue so or since that matrix has + + align:start position:0% +eigenvalue so or since that matrix has + + + align:start position:0% +eigenvalue so or since that matrix has +rank one so tell me the eigenvalues of + + align:start position:0% +rank one so tell me the eigenvalues of + + + align:start position:0% +rank one so tell me the eigenvalues of +this matrix it's a singular matrix so it + + align:start position:0% +this matrix it's a singular matrix so it + + + align:start position:0% +this matrix it's a singular matrix so it +certainly has an eigenvalue zero + + align:start position:0% +certainly has an eigenvalue zero + + + align:start position:0% +certainly has an eigenvalue zero +actually the rank is only one so that + + align:start position:0% +actually the rank is only one so that + + + align:start position:0% +actually the rank is only one so that +means that there's like going to be a + + align:start position:0% +means that there's like going to be a + + + align:start position:0% +means that there's like going to be a +two dimensional null space there be at + + align:start position:0% +two dimensional null space there be at + + + align:start position:0% +two dimensional null space there be at +least two this land this lambda equal + + align:start position:0% +least two this land this lambda equal + + + align:start position:0% +least two this land this lambda equal +zero will be repeated twice because I + + align:start position:0% +zero will be repeated twice because I + + + align:start position:0% +zero will be repeated twice because I +could find two independent eigenvectors + + align:start position:0% +could find two independent eigenvectors + + + align:start position:0% +could find two independent eigenvectors +with lambda equals zero and then of + + align:start position:0% +with lambda equals zero and then of + + + align:start position:0% +with lambda equals zero and then of +course since it's got three eigenvalues + + align:start position:0% +course since it's got three eigenvalues + + + align:start position:0% +course since it's got three eigenvalues +what's the third one it's one how do I + + align:start position:0% +what's the third one it's one how do I + + + align:start position:0% +what's the third one it's one how do I +know it's one either from the trace + + align:start position:0% +know it's one either from the trace + + + align:start position:0% +know it's one either from the trace +which is nine over nine which is one or + + align:start position:0% +which is nine over nine which is one or + + + align:start position:0% +which is nine over nine which is one or +by remembering what what is the + + align:start position:0% +by remembering what what is the + + + align:start position:0% +by remembering what what is the +eigenvector and actually now it's going + + align:start position:0% +eigenvector and actually now it's going + + + align:start position:0% +eigenvector and actually now it's going +to ask for the eigenvector so what's the + + align:start position:0% +to ask for the eigenvector so what's the + + + align:start position:0% +to ask for the eigenvector so what's the +eigenvector for that eigenvalue what's + + align:start position:0% +eigenvector for that eigenvalue what's + + + align:start position:0% +eigenvector for that eigenvalue what's +the eigenvector for that eigenvalue it's + + align:start position:0% +the eigenvector for that eigenvalue it's + + + align:start position:0% +the eigenvector for that eigenvalue it's +the vector it's the it's the vector that + + align:start position:0% +the vector it's the it's the vector that + + + align:start position:0% +the vector it's the it's the vector that +doesn't move I can value one so the + + align:start position:0% +doesn't move I can value one so the + + + align:start position:0% +doesn't move I can value one so the +vector that doesn't move is a this a is + + align:start position:0% +vector that doesn't move is a this a is + + + align:start position:0% +vector that doesn't move is a this a is +the is also the eigenvector with lambda + + align:start position:0% +the is also the eigenvector with lambda + + + align:start position:0% +the is also the eigenvector with lambda +equal one because if I apply the + + align:start position:0% +equal one because if I apply the + + + align:start position:0% +equal one because if I apply the +projection matrix to a I get a again + + align:start position:0% +projection matrix to a I get a again + + + align:start position:0% +projection matrix to a I get a again +everybody sees it if I apply that matrix + + align:start position:0% +everybody sees it if I apply that matrix + + + align:start position:0% +everybody sees it if I apply that matrix +to a can I do it in little letters if I + + align:start position:0% +to a can I do it in little letters if I + + + align:start position:0% +to a can I do it in little letters if I +apply that matrix to a then I have a + + align:start position:0% +apply that matrix to a then I have a + + + align:start position:0% +apply that matrix to a then I have a +transpose a canceling a transpose a and + + align:start position:0% +transpose a canceling a transpose a and + + + align:start position:0% +transpose a canceling a transpose a and +I get a again so sure enough PA equals a + + align:start position:0% +I get a again so sure enough PA equals a + + + align:start position:0% +I get a again so sure enough PA equals a +and the eigenvalue is one okay good now + + align:start position:0% +and the eigenvalue is one okay good now + + + align:start position:0% +and the eigenvalue is one okay good now +actually it asks you further to solve + + align:start position:0% +actually it asks you further to solve + + + align:start position:0% +actually it asks you further to solve +this difference equation so this will be + + align:start position:0% +this difference equation so this will be + + + align:start position:0% +this difference equation so this will be +this is this is solve you k plus 1 + + align:start position:0% +this is this is solve you k plus 1 + + + align:start position:0% +this is this is solve you k plus 1 +equals PUK starting from u 0 equal 9 9 0 + + align:start position:0% +equals PUK starting from u 0 equal 9 9 0 + + + align:start position:0% +equals PUK starting from u 0 equal 9 9 0 +and find you K so so what's up so we + + align:start position:0% +and find you K so so what's up so we + + + align:start position:0% +and find you K so so what's up so we +find you one first of all so just to get + + align:start position:0% +find you one first of all so just to get + + + align:start position:0% +find you one first of all so just to get +started so what is u 1 + + align:start position:0% +started so what is u 1 + + + align:start position:0% +started so what is u 1 +it's PU 0 of course + + align:start position:0% +it's PU 0 of course + + + align:start position:0% +it's PU 0 of course +so if I do the projection of this vector + + align:start position:0% +so if I do the projection of this vector + + + align:start position:0% +so if I do the projection of this vector +onto the line so this is like my vector + + align:start position:0% +onto the line so this is like my vector + + + align:start position:0% +onto the line so this is like my vector +B now that I'm projecting onto the line + + align:start position:0% +B now that I'm projecting onto the line + + + align:start position:0% +B now that I'm projecting onto the line +I get a times a transpose u 0 over a + + align:start position:0% +I get a times a transpose u 0 over a + + + align:start position:0% +I get a times a transpose u 0 over a +transpose a well in one way or another I + + align:start position:0% +transpose a well in one way or another I + + + align:start position:0% +transpose a well in one way or another I +just do this multiplication but maybe + + align:start position:0% +just do this multiplication but maybe + + + align:start position:0% +just do this multiplication but maybe +this is the easiest way to do it + + align:start position:0% +this is the easiest way to do it + + + align:start position:0% +this is the easiest way to do it +a transpose can I remember what a is on + + align:start position:0% +a transpose can I remember what a is on + + + align:start position:0% +a transpose can I remember what a is on +this board 2 1 2 so I'm projecting onto + + align:start position:0% +this board 2 1 2 so I'm projecting onto + + + align:start position:0% +this board 2 1 2 so I'm projecting onto +the line through there this is the + + align:start position:0% +the line through there this is the + + + align:start position:0% +the line through there this is the +projection it's P times the vector u 0 + + align:start position:0% +projection it's P times the vector u 0 + + + align:start position:0% +projection it's P times the vector u 0 +so what do I have for a transpose u 0 + + align:start position:0% +so what do I have for a transpose u 0 + + + align:start position:0% +so what do I have for a transpose u 0 +looks like 18 looks like 27 and a + + align:start position:0% +looks like 18 looks like 27 and a + + + align:start position:0% +looks like 18 looks like 27 and a +transpose a we figured was 9 so it's 3 a + + align:start position:0% +transpose a we figured was 9 so it's 3 a + + + align:start position:0% +transpose a we figured was 9 so it's 3 a +so that this is the this is the X hat + + align:start position:0% +so that this is the this is the X hat + + + align:start position:0% +so that this is the this is the X hat +the the multiple of a in our formulas + + align:start position:0% +the the multiple of a in our formulas + + + align:start position:0% +the the multiple of a in our formulas +and of course that's 6 3 6 + + align:start position:0% + + + + align:start position:0% + +so that's you one computed out directly + + align:start position:0% +so that's you one computed out directly + + + align:start position:0% +so that's you one computed out directly +that's on the line through a and it's + + align:start position:0% +that's on the line through a and it's + + + align:start position:0% +that's on the line through a and it's +the closest point to you zero and it's + + align:start position:0% +the closest point to you zero and it's + + + align:start position:0% +the closest point to you zero and it's +just pu zero you just straight forward + + align:start position:0% +just pu zero you just straight forward + + + align:start position:0% +just pu zero you just straight forward +multiplication produces that okay now + + align:start position:0% +multiplication produces that okay now + + + align:start position:0% +multiplication produces that okay now +what's you two + + align:start position:0% + + + + align:start position:0% + +well you two is P you one I agree + + align:start position:0% +well you two is P you one I agree + + + align:start position:0% +well you two is P you one I agree +do I need to compute that again no + + align:start position:0% +do I need to compute that again no + + + align:start position:0% +do I need to compute that again no +because once I'm already on the line + + align:start position:0% +because once I'm already on the line + + + align:start position:0% +because once I'm already on the line +through a UK will be I could do the + + align:start position:0% +through a UK will be I could do the + + + align:start position:0% +through a UK will be I could do the +projection K times but it's enough just + + align:start position:0% +projection K times but it's enough just + + + align:start position:0% +projection K times but it's enough just +to do it once it's the same it's this + + align:start position:0% +to do it once it's the same it's this + + + align:start position:0% +to do it once it's the same it's this +same six three six so this is a case + + align:start position:0% +same six three six so this is a case + + + align:start position:0% +same six three six so this is a case +where I could and actually on the quiz + + align:start position:0% +where I could and actually on the quiz + + + align:start position:0% +where I could and actually on the quiz +if you see one of these which could very + + align:start position:0% +if you see one of these which could very + + + align:start position:0% +if you see one of these which could very +well be there and it could very well be + + align:start position:0% +well be there and it could very well be + + + align:start position:0% +well be there and it could very well be +not a projection matrix then we would + + align:start position:0% +not a projection matrix then we would + + + align:start position:0% +not a projection matrix then we would +use all the eigenvalues and eigenvectors + + align:start position:0% +use all the eigenvalues and eigenvectors + + + align:start position:0% +use all the eigenvalues and eigenvectors +let's think for a moment how do you do + + align:start position:0% +let's think for a moment how do you do + + + align:start position:0% +let's think for a moment how do you do +those the point of this small part of a + + align:start position:0% +those the point of this small part of a + + + align:start position:0% +those the point of this small part of a +question was that when p is a projection + + align:start position:0% +question was that when p is a projection + + + align:start position:0% +question was that when p is a projection +matrix so that p squared equals p and p + + align:start position:0% +matrix so that p squared equals p and p + + + align:start position:0% +matrix so that p squared equals p and p +cubed equals p then then we don't need + + align:start position:0% +cubed equals p then then we don't need + + + align:start position:0% +cubed equals p then then we don't need +to get into the mechanics of all knowing + + align:start position:0% +to get into the mechanics of all knowing + + + align:start position:0% +to get into the mechanics of all knowing +all the other eigenvalues and + + align:start position:0% +all the other eigenvalues and + + + align:start position:0% +all the other eigenvalues and +eigenvectors we just can go directly but + + align:start position:0% +eigenvectors we just can go directly but + + + align:start position:0% +eigenvectors we just can go directly but +if p was now some other matrix can you + + align:start position:0% +if p was now some other matrix can you + + + align:start position:0% +if p was now some other matrix can you +just just just remember from these very + + align:start position:0% +just just just remember from these very + + + align:start position:0% +just just just remember from these very +recent lectures how you would proceed + + align:start position:0% +recent lectures how you would proceed + + + align:start position:0% +recent lectures how you would proceed +from these very recent lectures we know + + align:start position:0% +from these very recent lectures we know + + + align:start position:0% +from these very recent lectures we know +that UK we would we would expand u 0 as + + align:start position:0% +that UK we would we would expand u 0 as + + + align:start position:0% +that UK we would we would expand u 0 as +a combination of eigenvectors let me + + align:start position:0% +a combination of eigenvectors let me + + + align:start position:0% +a combination of eigenvectors let me +leave ya as a combination of + + align:start position:0% +leave ya as a combination of + + + align:start position:0% +leave ya as a combination of +eigenvectors c 1 x 1 some multiple of + + align:start position:0% +eigenvectors c 1 x 1 some multiple of + + + align:start position:0% +eigenvectors c 1 x 1 some multiple of +the second eigenvector some multiple of + + align:start position:0% +the second eigenvector some multiple of + + + align:start position:0% +the second eigenvector some multiple of +a third eigenvector and then a to the k + + align:start position:0% +a third eigenvector and then a to the k + + + align:start position:0% +a third eigenvector and then a to the k +u 0 + + align:start position:0% +u 0 + + + align:start position:0% +u 0 +would be c1 so this we have to find + + align:start position:0% +would be c1 so this we have to find + + + align:start position:0% +would be c1 so this we have to find +these numbers here that's the work + + align:start position:0% +these numbers here that's the work + + + align:start position:0% +these numbers here that's the work +actually the work is find the + + align:start position:0% +actually the work is find the + + + align:start position:0% +actually the work is find the +eigenvalues find the eigenvectors and + + align:start position:0% +eigenvalues find the eigenvectors and + + + align:start position:0% +eigenvalues find the eigenvectors and +find the C's because they all come into + + align:start position:0% +find the C's because they all come into + + + align:start position:0% +find the C's because they all come into +the formula we have so so to do this you + + align:start position:0% +the formula we have so so to do this you + + + align:start position:0% +the formula we have so so to do this you +can see what you have to compute you + + align:start position:0% +can see what you have to compute you + + + align:start position:0% +can see what you have to compute you +have to compute the eigenvalues you have + + align:start position:0% +have to compute the eigenvalues you have + + + align:start position:0% +have to compute the eigenvalues you have +to compute the eigenvectors and then to + + align:start position:0% +to compute the eigenvectors and then to + + + align:start position:0% +to compute the eigenvectors and then to +match you not you compute the C's and + + align:start position:0% +match you not you compute the C's and + + + align:start position:0% +match you not you compute the C's and +then you've got it so it's it's just + + align:start position:0% +then you've got it so it's it's just + + + align:start position:0% +then you've got it so it's it's just +that's a formula that shows what pieces + + align:start position:0% +that's a formula that shows what pieces + + + align:start position:0% +that's a formula that shows what pieces +we need and what would actually happen + + align:start position:0% +we need and what would actually happen + + + align:start position:0% +we need and what would actually happen +in the case of this projection matrix if + + align:start position:0% +in the case of this projection matrix if + + + align:start position:0% +in the case of this projection matrix if +this a is a projection matrix then a + + align:start position:0% +this a is a projection matrix then a + + + align:start position:0% +this a is a projection matrix then a +couple of eigenvalues are 0 that's why + + align:start position:0% +couple of eigenvalues are 0 that's why + + + align:start position:0% +couple of eigenvalues are 0 that's why +we just throw those away the other + + align:start position:0% +we just throw those away the other + + + align:start position:0% +we just throw those away the other +eigenvalue is a 1 so that we got the + + align:start position:0% +eigenvalue is a 1 so that we got the + + + align:start position:0% +eigenvalue is a 1 so that we got the +same thing every time see 3x3 from the + + align:start position:0% +same thing every time see 3x3 from the + + + align:start position:0% +same thing every time see 3x3 from the +first time second time third all + + align:start position:0% +first time second time third all + + + align:start position:0% +first time second time third all +iterations press with this constant left + + align:start position:0% +iterations press with this constant left + + + align:start position:0% +iterations press with this constant left +us right here at 6:36 but maybe I take + + align:start position:0% +us right here at 6:36 but maybe I take + + + align:start position:0% +us right here at 6:36 but maybe I take +I'm taking this chance to remind you of + + align:start position:0% +I'm taking this chance to remind you of + + + align:start position:0% +I'm taking this chance to remind you of +what to do for other matrices ok so + + align:start position:0% +what to do for other matrices ok so + + + align:start position:0% +what to do for other matrices ok so +that's a part way through ok the next + + align:start position:0% +that's a part way through ok the next + + + align:start position:0% +that's a part way through ok the next +question in 1984 is fitting a straight + + align:start position:0% +question in 1984 is fitting a straight + + + align:start position:0% +question in 1984 is fitting a straight +line to points and actually a straight + + align:start position:0% +line to points and actually a straight + + + align:start position:0% +line to points and actually a straight +line through the origin a straight line + + align:start position:0% +line through the origin a straight line + + + align:start position:0% +line through the origin a straight line +through the origin so can I go to + + align:start position:0% +through the origin so can I go to + + + align:start position:0% +through the origin so can I go to +question two so this is fitting a + + align:start position:0% +question two so this is fitting a + + + align:start position:0% +question two so this is fitting a +straight line to these points can I I'll + + align:start position:0% +straight line to these points can I I'll + + + align:start position:0% +straight line to these points can I I'll +just give you the points at T equal 1 + + align:start position:0% +just give you the points at T equal 1 + + + align:start position:0% +just give you the points at T equal 1 +the Y is 4 at T equal to 2 y is 5 at t + + align:start position:0% +the Y is 4 at T equal to 2 y is 5 at t + + + align:start position:0% +the Y is 4 at T equal to 2 y is 5 at t +equal to 3 y is 8 + + align:start position:0% + + + + align:start position:0% + +so we've got points one two three four + + align:start position:0% +so we've got points one two three four + + + align:start position:0% +so we've got points one two three four +five and eight and I'm trying to fit a + + align:start position:0% +five and eight and I'm trying to fit a + + + align:start position:0% +five and eight and I'm trying to fit a +straight line through the origin to + + align:start position:0% +straight line through the origin to + + + align:start position:0% +straight line through the origin to +these three values okay so my equation + + align:start position:0% +these three values okay so my equation + + + align:start position:0% +these three values okay so my equation +that I'm allowing myself is just y equal + + align:start position:0% +that I'm allowing myself is just y equal + + + align:start position:0% +that I'm allowing myself is just y equal +DT so I have only one unknown one degree + + align:start position:0% +DT so I have only one unknown one degree + + + align:start position:0% +DT so I have only one unknown one degree +of freedom one parameter D so I'm + + align:start position:0% +of freedom one parameter D so I'm + + + align:start position:0% +of freedom one parameter D so I'm +expecting to end up my matrix so my my + + align:start position:0% +expecting to end up my matrix so my my + + + align:start position:0% +expecting to end up my matrix so my my +when I try to when I try to fit a + + align:start position:0% +when I try to when I try to fit a + + + align:start position:0% +when I try to when I try to fit a +straight line that goes through the + + align:start position:0% +straight line that goes through the + + + align:start position:0% +straight line that goes through the +origin that's because it goes through + + align:start position:0% +origin that's because it goes through + + + align:start position:0% +origin that's because it goes through +the origin I've lost the constant C here + + align:start position:0% +the origin I've lost the constant C here + + + align:start position:0% +the origin I've lost the constant C here +so I have just this should be a quick + + align:start position:0% +so I have just this should be a quick + + + align:start position:0% +so I have just this should be a quick +calculation and I can write down the + + align:start position:0% +calculation and I can write down the + + + align:start position:0% +calculation and I can write down the +three equations that that would I'd like + + align:start position:0% +three equations that that would I'd like + + + align:start position:0% +three equations that that would I'd like +to solve if the line went through the + + align:start position:0% +to solve if the line went through the + + + align:start position:0% +to solve if the line went through the +points that's a good start because that + + align:start position:0% +points that's a good start because that + + + align:start position:0% +points that's a good start because that +displays the matrix so can I continue + + align:start position:0% +displays the matrix so can I continue + + + align:start position:0% +displays the matrix so can I continue +that problem we would like to solve so + + align:start position:0% +that problem we would like to solve so + + + align:start position:0% +that problem we would like to solve so +why is DT so I'd like to solve D times + + align:start position:0% +why is DT so I'd like to solve D times + + + align:start position:0% +why is DT so I'd like to solve D times +one times D equals four two times D + + align:start position:0% +one times D equals four two times D + + + align:start position:0% +one times D equals four two times D +equals five and three times D equals + + align:start position:0% +equals five and three times D equals + + + align:start position:0% +equals five and three times D equals +eight + + align:start position:0% +eight + + + align:start position:0% +eight +that would be perfection if I could find + + align:start position:0% +that would be perfection if I could find + + + align:start position:0% +that would be perfection if I could find +such a D then the line y equal DT would + + align:start position:0% +such a D then the line y equal DT would + + + align:start position:0% +such a D then the line y equal DT would +satisfy all three equations would go + + align:start position:0% +satisfy all three equations would go + + + align:start position:0% +satisfy all three equations would go +through all three points but it doesn't + + align:start position:0% +through all three points but it doesn't + + + align:start position:0% +through all three points but it doesn't +exist so so I have to solve this so that + + align:start position:0% +exist so so I have to solve this so that + + + align:start position:0% +exist so so I have to solve this so that +my matrix is now you can see my matrix + + align:start position:0% +my matrix is now you can see my matrix + + + align:start position:0% +my matrix is now you can see my matrix +it just has one column multiplying a + + align:start position:0% +it just has one column multiplying a + + + align:start position:0% +it just has one column multiplying a +scalar D and you can see the right-hand + + align:start position:0% +scalar D and you can see the right-hand + + + align:start position:0% +scalar D and you can see the right-hand +side this is my a X equal B I don't need + + align:start position:0% +side this is my a X equal B I don't need + + + align:start position:0% +side this is my a X equal B I don't need +three equal signs now cuz I've got + + align:start position:0% +three equal signs now cuz I've got + + + align:start position:0% +three equal signs now cuz I've got +vectors okay + + align:start position:0% +vectors okay + + + align:start position:0% +vectors okay +there's a X equal B and you take it from + + align:start position:0% +there's a X equal B and you take it from + + + align:start position:0% +there's a X equal B and you take it from +there + + align:start position:0% +there + + + align:start position:0% +there +you the best + + align:start position:0% +you the best + + + align:start position:0% +you the best +we'll be we'll come from so what's the + + align:start position:0% +we'll be we'll come from so what's the + + + align:start position:0% +we'll be we'll come from so what's the +the key equation so here this is the a + + align:start position:0% +the key equation so here this is the a + + + align:start position:0% +the key equation so here this is the a +this is the ax hat equal B equation + + align:start position:0% +this is the ax hat equal B equation + + + align:start position:0% +this is the ax hat equal B equation +well ax equal B and what's the equation + + align:start position:0% +well ax equal B and what's the equation + + + align:start position:0% +well ax equal B and what's the equation +for x hat the best D so to find the best + + align:start position:0% +for x hat the best D so to find the best + + + align:start position:0% +for x hat the best D so to find the best +D the best X the equation is a transpose + + align:start position:0% +D the best X the equation is a transpose + + + align:start position:0% +D the best X the equation is a transpose +a the best D is a transpose times the + + align:start position:0% +a the best D is a transpose times the + + + align:start position:0% +a the best D is a transpose times the +right hand side this is all coming from + + align:start position:0% +right hand side this is all coming from + + + align:start position:0% +right hand side this is all coming from +projection on a line or our matrix only + + align:start position:0% +projection on a line or our matrix only + + + align:start position:0% +projection on a line or our matrix only +has one column so a transpose a would be + + align:start position:0% +has one column so a transpose a would be + + + align:start position:0% +has one column so a transpose a would be +maybe 14 D hat and a transpose B I'm + + align:start position:0% +maybe 14 D hat and a transpose B I'm + + + align:start position:0% +maybe 14 D hat and a transpose B I'm +getting four ten and twenty four is that + + align:start position:0% +getting four ten and twenty four is that + + + align:start position:0% +getting four ten and twenty four is that +right for ten and twenty four so thirty + + align:start position:0% +right for ten and twenty four so thirty + + + align:start position:0% +right for ten and twenty four so thirty +eight so that tells me the best D hat is + + align:start position:0% +eight so that tells me the best D hat is + + + align:start position:0% +eight so that tells me the best D hat is +d hat is 38 over fourteen okay fine + + align:start position:0% +d hat is 38 over fourteen okay fine + + + align:start position:0% +d hat is 38 over fourteen okay fine +alright so we found the best line and + + align:start position:0% +alright so we found the best line and + + + align:start position:0% +alright so we found the best line and +now here's a here's the next question + + align:start position:0% +now here's a here's the next question + + + align:start position:0% +now here's a here's the next question +what vector did I just project onto what + + align:start position:0% +what vector did I just project onto what + + + align:start position:0% +what vector did I just project onto what +line see in this section on least + + align:start position:0% +line see in this section on least + + + align:start position:0% +line see in this section on least +squares here's the key point + + align:start position:0% +squares here's the key point + + + align:start position:0% +squares here's the key point +I'm asking you to think of the least + + align:start position:0% +I'm asking you to think of the least + + + align:start position:0% +I'm asking you to think of the least +squares problem in two ways two + + align:start position:0% +squares problem in two ways two + + + align:start position:0% +squares problem in two ways two +different pictures two different graphs + + align:start position:0% +different pictures two different graphs + + + align:start position:0% +different pictures two different graphs +one graph is this this is a graph in the + + align:start position:0% +one graph is this this is a graph in the + + + align:start position:0% +one graph is this this is a graph in the +in the B and the TB flame T Y plane the + + align:start position:0% +in the B and the TB flame T Y plane the + + + align:start position:0% +in the B and the TB flame T Y plane the +line itself the other picture I'm asking + + align:start position:0% +line itself the other picture I'm asking + + + align:start position:0% +line itself the other picture I'm asking +you to think of is like my projection + + align:start position:0% +you to think of is like my projection + + + align:start position:0% +you to think of is like my projection +picture what what what projection what + + align:start position:0% +picture what what what projection what + + + align:start position:0% +picture what what what projection what +what vector am I am i projecting onto + + align:start position:0% +what vector am I am i projecting onto + + + align:start position:0% +what vector am I am i projecting onto +what line or what subspace when i when i + + align:start position:0% +what line or what subspace when i when i + + + align:start position:0% +what line or what subspace when i when i +do this so is my second picture is a + + align:start position:0% +do this so is my second picture is a + + + align:start position:0% +do this so is my second picture is a +projection picture that sees the whole + + align:start position:0% +projection picture that sees the whole + + + align:start position:0% +projection picture that sees the whole +thing with vectors here's my vector of + + align:start position:0% +thing with vectors here's my vector of + + + align:start position:0% +thing with vectors here's my vector of +course that I'm projecting I'm + + align:start position:0% +course that I'm projecting I'm + + + align:start position:0% +course that I'm projecting I'm +projecting + + align:start position:0% + + + + align:start position:0% + +that vector B onto the column space of a + + align:start position:0% +that vector B onto the column space of a + + + align:start position:0% +that vector B onto the column space of a +or if you like it's just a line on two + + align:start position:0% +or if you like it's just a line on two + + + align:start position:0% +or if you like it's just a line on two +that's the line it's just a line of + + align:start position:0% +that's the line it's just a line of + + + align:start position:0% +that's the line it's just a line of +course that's what this calculation is + + align:start position:0% +course that's what this calculation is + + + align:start position:0% +course that's what this calculation is +doing this is computing the best D which + + align:start position:0% +doing this is computing the best D which + + + align:start position:0% +doing this is computing the best D which +is this is the X hat so so seeing it as + + align:start position:0% +is this is the X hat so so seeing it as + + + align:start position:0% +is this is the X hat so so seeing it as +a projection means I don't see the + + align:start position:0% +a projection means I don't see the + + + align:start position:0% +a projection means I don't see the +projection in this figure right in this + + align:start position:0% +projection in this figure right in this + + + align:start position:0% +projection in this figure right in this +figure I'm not projecting those points + + align:start position:0% +figure I'm not projecting those points + + + align:start position:0% +figure I'm not projecting those points +onto that line or anything of the sort + + align:start position:0% +onto that line or anything of the sort + + + align:start position:0% +onto that line or anything of the sort +the projection picture for for least + + align:start position:0% +the projection picture for for least + + + align:start position:0% +the projection picture for for least +squares is in the plane in the space + + align:start position:0% +squares is in the plane in the space + + + align:start position:0% +squares is in the plane in the space +where B lies the whole vector B and the + + align:start position:0% +where B lies the whole vector B and the + + + align:start position:0% +where B lies the whole vector B and the +columns of a and then the X is the best + + align:start position:0% +columns of a and then the X is the best + + + align:start position:0% +columns of a and then the X is the best +combination that gives the projection + + align:start position:0% +combination that gives the projection + + + align:start position:0% +combination that gives the projection +okay so that's a chance to tell me that + + align:start position:0% +okay so that's a chance to tell me that + + + align:start position:0% +okay so that's a chance to tell me that +okay I'll go okay now finally in + + align:start position:0% +okay I'll go okay now finally in + + + align:start position:0% +okay I'll go okay now finally in +orthogonality there's the gram-schmidt + + align:start position:0% +orthogonality there's the gram-schmidt + + + align:start position:0% +orthogonality there's the gram-schmidt +idea so that's problem 2d here it asks + + align:start position:0% +idea so that's problem 2d here it asks + + + align:start position:0% +idea so that's problem 2d here it asks +me if I have two vectors a1 equal 1 2 3 + + align:start position:0% +me if I have two vectors a1 equal 1 2 3 + + + align:start position:0% +me if I have two vectors a1 equal 1 2 3 +and a 2 equal 1 1 1 find two orthogonal + + align:start position:0% +and a 2 equal 1 1 1 find two orthogonal + + + align:start position:0% +and a 2 equal 1 1 1 find two orthogonal +vectors in that plane so those two + + align:start position:0% +vectors in that plane so those two + + + align:start position:0% +vectors in that plane so those two +vectors give a plane they give a plane + + align:start position:0% +vectors give a plane they give a plane + + + align:start position:0% +vectors give a plane they give a plane +which is of course the column space of + + align:start position:0% +which is of course the column space of + + + align:start position:0% +which is of course the column space of +the of the matrix and I'm looking for an + + align:start position:0% +the of the matrix and I'm looking for an + + + align:start position:0% +the of the matrix and I'm looking for an +orthogonal basis for that plane so I'm + + align:start position:0% +orthogonal basis for that plane so I'm + + + align:start position:0% +orthogonal basis for that plane so I'm +looking for two orthogonal vectors and + + align:start position:0% +looking for two orthogonal vectors and + + + align:start position:0% +looking for two orthogonal vectors and +of course there were lots of I mean I've + + align:start position:0% +of course there were lots of I mean I've + + + align:start position:0% +of course there were lots of I mean I've +got a plane there if I get one + + align:start position:0% +got a plane there if I get one + + + align:start position:0% +got a plane there if I get one +orthogonal pair I can rotate it there's + + align:start position:0% +orthogonal pair I can rotate it there's + + + align:start position:0% +orthogonal pair I can rotate it there's +not just one answer here but gram + + align:start position:0% +not just one answer here but gram + + + align:start position:0% +not just one answer here but gram +Schmidt says okay start with the first + + align:start position:0% +Schmidt says okay start with the first + + + align:start position:0% +Schmidt says okay start with the first +vector and let that be and keep that one + + align:start position:0% +vector and let that be and keep that one + + + align:start position:0% +vector and let that be and keep that one +and then take the second one orthogonal + + align:start position:0% +and then take the second one orthogonal + + + align:start position:0% +and then take the second one orthogonal +to this so so gram schmidt says start + + align:start position:0% +to this so so gram schmidt says start + + + align:start position:0% +to this so so gram schmidt says start +with this one and then make a second + + align:start position:0% +with this one and then make a second + + + align:start position:0% +with this one and then make a second +vector B can I call that second vector B + + align:start position:0% +vector B can I call that second vector B + + + align:start position:0% +vector B can I call that second vector B +this is going to be orthogonal to so + + align:start position:0% +this is going to be orthogonal to so + + + align:start position:0% +this is going to be orthogonal to so +perpendicular to a-1 if I could with my + + align:start position:0% +perpendicular to a-1 if I could with my + + + align:start position:0% +perpendicular to a-1 if I could with my +chalk create the key equation this + + align:start position:0% +chalk create the key equation this + + + align:start position:0% +chalk create the key equation this +vector B is going to be this 1 1 1 but + + align:start position:0% +vector B is going to be this 1 1 1 but + + + align:start position:0% +vector B is going to be this 1 1 1 but +that 1 1 1 1 1 is not perpendicular to a + + align:start position:0% +that 1 1 1 1 1 is not perpendicular to a + + + align:start position:0% +that 1 1 1 1 1 is not perpendicular to a +1 so I have to subtract off its + + align:start position:0% +1 so I have to subtract off its + + + align:start position:0% +1 so I have to subtract off its +projection I have to subtract off the be + + align:start position:0% +projection I have to subtract off the be + + + align:start position:0% +projection I have to subtract off the be +the the be transfer or yeah the B I + + align:start position:0% +the the be transfer or yeah the B I + + + align:start position:0% +the the be transfer or yeah the B I +should say the a 1 transpose B over a 1 + + align:start position:0% +should say the a 1 transpose B over a 1 + + + align:start position:0% +should say the a 1 transpose B over a 1 +transpose a 1 that multiple of a 1 I've + + align:start position:0% +transpose a 1 that multiple of a 1 I've + + + align:start position:0% +transpose a 1 that multiple of a 1 I've +got to remove so I just have to compute + + align:start position:0% +got to remove so I just have to compute + + + align:start position:0% +got to remove so I just have to compute +what that is and I get in I get a vector + + align:start position:0% +what that is and I get in I get a vector + + + align:start position:0% +what that is and I get in I get a vector +B that's orthogonal to a-1 it's the it's + + align:start position:0% +B that's orthogonal to a-1 it's the it's + + + align:start position:0% +B that's orthogonal to a-1 it's the it's +it's the original vector minus its + + align:start position:0% +it's the original vector minus its + + + align:start position:0% +it's the original vector minus its +projection oh so what is I mean this to + + align:start position:0% +projection oh so what is I mean this to + + + align:start position:0% +projection oh so what is I mean this to +be a 2 + + align:start position:0% +be a 2 + + + align:start position:0% +be a 2 +yeah so I'm projecting a 2 onto the line + + align:start position:0% +yeah so I'm projecting a 2 onto the line + + + align:start position:0% +yeah so I'm projecting a 2 onto the line +through a 1 that's the part that I don't + + align:start position:0% +through a 1 that's the part that I don't + + + align:start position:0% +through a 1 that's the part that I don't +want cuz that's in the direction I + + align:start position:0% +want cuz that's in the direction I + + + align:start position:0% +want cuz that's in the direction I +already have so I subtract off that + + align:start position:0% +already have so I subtract off that + + + align:start position:0% +already have so I subtract off that +projection and I get the part I want the + + align:start position:0% +projection and I get the part I want the + + + align:start position:0% +projection and I get the part I want the +orthogonal part okay so that's the + + align:start position:0% +orthogonal part okay so that's the + + + align:start position:0% +orthogonal part okay so that's the +gram-schmidt thing and we can put + + align:start position:0% +gram-schmidt thing and we can put + + + align:start position:0% +gram-schmidt thing and we can put +numbers in 1 1 1 take away a 1 transpose + + align:start position:0% +numbers in 1 1 1 take away a 1 transpose + + + align:start position:0% +numbers in 1 1 1 take away a 1 transpose +a 2 is 6 a 1 transpose a 1 is 14 + + align:start position:0% +a 2 is 6 a 1 transpose a 1 is 14 + + + align:start position:0% +a 2 is 6 a 1 transpose a 1 is 14 +multiplying a 1 and that gives us the + + align:start position:0% +multiplying a 1 and that gives us the + + + align:start position:0% +multiplying a 1 and that gives us the +new orthogonal vector B because I only + + align:start position:0% +new orthogonal vector B because I only + + + align:start position:0% +new orthogonal vector B because I only +asked for orthogonal right now I don't + + align:start position:0% +asked for orthogonal right now I don't + + + align:start position:0% +asked for orthogonal right now I don't +have to divide by the length which will + + align:start position:0% +have to divide by the length which will + + + align:start position:0% +have to divide by the length which will +involve a square root ok + + align:start position:0% +involve a square root ok + + + align:start position:0% +involve a square root ok +third question third question alright + + align:start position:0% +third question third question alright + + + align:start position:0% +third question third question alright +let me I'll move this board up third + + align:start position:0% +let me I'll move this board up third + + + align:start position:0% +let me I'll move this board up third +question I'll probably be about + + align:start position:0% +question I'll probably be about + + + align:start position:0% +question I'll probably be about +eigenvalues okay three this is a four by + + align:start position:0% +eigenvalues okay three this is a four by + + + align:start position:0% +eigenvalues okay three this is a four by +four matrix its eigenvalues are lambda 1 + + align:start position:0% +four matrix its eigenvalues are lambda 1 + + + align:start position:0% +four matrix its eigenvalues are lambda 1 +lambda 2 lambda 3 lambda 4 question 1 + + align:start position:0% +lambda 2 lambda 3 lambda 4 question 1 + + + align:start position:0% +lambda 2 lambda 3 lambda 4 question 1 +what's the condition on the lambdas so + + align:start position:0% +what's the condition on the lambdas so + + + align:start position:0% +what's the condition on the lambdas so +that the matrix is invertible okay so + + align:start position:0% +that the matrix is invertible okay so + + + align:start position:0% +that the matrix is invertible okay so +under what conditions on the lambdas + + align:start position:0% +under what conditions on the lambdas + + + align:start position:0% +under what conditions on the lambdas +will the matrix be invertible so that's + + align:start position:0% +will the matrix be invertible so that's + + + align:start position:0% +will the matrix be invertible so that's +easy invertible if what's the condition + + align:start position:0% +easy invertible if what's the condition + + + align:start position:0% +easy invertible if what's the condition +on the lambdas none of them are zero a + + align:start position:0% +on the lambdas none of them are zero a + + + align:start position:0% +on the lambdas none of them are zero a +zero eigenvalue would mean something in + + align:start position:0% +zero eigenvalue would mean something in + + + align:start position:0% +zero eigenvalue would mean something in +the null space would be in a solution to + + align:start position:0% +the null space would be in a solution to + + + align:start position:0% +the null space would be in a solution to +ax equals zero X but we're invertible so + + align:start position:0% +ax equals zero X but we're invertible so + + + align:start position:0% +ax equals zero X but we're invertible so +none of them is 0 the product however + + align:start position:0% +none of them is 0 the product however + + + align:start position:0% +none of them is 0 the product however +you want to say no no zero eigenvalues + + align:start position:0% +you want to say no no zero eigenvalues + + + align:start position:0% +you want to say no no zero eigenvalues +good ok what's the determinant of a + + align:start position:0% +good ok what's the determinant of a + + + align:start position:0% +good ok what's the determinant of a +inverse the determinant of a inverse so + + align:start position:0% +inverse the determinant of a inverse so + + + align:start position:0% +inverse the determinant of a inverse so +where's that going to come from well if + + align:start position:0% +where's that going to come from well if + + + align:start position:0% +where's that going to come from well if +we knew the eigenvalues of a inverse we + + align:start position:0% +we knew the eigenvalues of a inverse we + + + align:start position:0% +we knew the eigenvalues of a inverse we +could multiply them together to find the + + align:start position:0% +could multiply them together to find the + + + align:start position:0% +could multiply them together to find the +determinant and we do know the + + align:start position:0% +determinant and we do know the + + + align:start position:0% +determinant and we do know the +eigenvalues of a inverse what are they + + align:start position:0% +eigenvalues of a inverse what are they + + + align:start position:0% +eigenvalues of a inverse what are they +they're just 1 over lambda 1 times 1 + + align:start position:0% +they're just 1 over lambda 1 times 1 + + + align:start position:0% +they're just 1 over lambda 1 times 1 +over lambda 2 that's the second + + align:start position:0% +over lambda 2 that's the second + + + align:start position:0% +over lambda 2 that's the second +eigenvalue the third eigenvalue and the + + align:start position:0% +eigenvalue the third eigenvalue and the + + + align:start position:0% +eigenvalue the third eigenvalue and the +fourth so the product of the four + + align:start position:0% +fourth so the product of the four + + + align:start position:0% +fourth so the product of the four +eigenvalues of the inverse will give us + + align:start position:0% +eigenvalues of the inverse will give us + + + align:start position:0% +eigenvalues of the inverse will give us +the determinant of the inverse fine okay + + align:start position:0% +the determinant of the inverse fine okay + + + align:start position:0% +the determinant of the inverse fine okay +and what's the trace of a plus I + + align:start position:0% + + + + align:start position:0% + +so what do we know about trace it's the + + align:start position:0% +so what do we know about trace it's the + + + align:start position:0% +so what do we know about trace it's the +sum down the diagonal but we don't know + + align:start position:0% +sum down the diagonal but we don't know + + + align:start position:0% +sum down the diagonal but we don't know +what our matrix is the trace is also the + + align:start position:0% +what our matrix is the trace is also the + + + align:start position:0% +what our matrix is the trace is also the +sum of the eigenvalues and we do know + + align:start position:0% +sum of the eigenvalues and we do know + + + align:start position:0% +sum of the eigenvalues and we do know +the eigenvalues of a plus I so we just + + align:start position:0% +the eigenvalues of a plus I so we just + + + align:start position:0% +the eigenvalues of a plus I so we just +add them up so what's the first + + align:start position:0% +add them up so what's the first + + + align:start position:0% +add them up so what's the first +eigenvalue of a plus I when the matrix a + + align:start position:0% +eigenvalue of a plus I when the matrix a + + + align:start position:0% +eigenvalue of a plus I when the matrix a +has eigenvalues lambda 1 2 3 & 4 then + + align:start position:0% +has eigenvalues lambda 1 2 3 & 4 then + + + align:start position:0% +has eigenvalues lambda 1 2 3 & 4 then +the eigenvalues if I add the identity + + align:start position:0% +the eigenvalues if I add the identity + + + align:start position:0% +the eigenvalues if I add the identity +that moves all the eigenvalues by 1 so I + + align:start position:0% +that moves all the eigenvalues by 1 so I + + + align:start position:0% +that moves all the eigenvalues by 1 so I +just add up lambda 1 plus 1 lambda 2 + + align:start position:0% +just add up lambda 1 plus 1 lambda 2 + + + align:start position:0% +just add up lambda 1 plus 1 lambda 2 +plus 1 and so on lambda 3 plus 1 lambda + + align:start position:0% +plus 1 and so on lambda 3 plus 1 lambda + + + align:start position:0% +plus 1 and so on lambda 3 plus 1 lambda +4 plus 1 so it's lambda 1 plus lambda 2 + + align:start position:0% +4 plus 1 so it's lambda 1 plus lambda 2 + + + align:start position:0% +4 plus 1 so it's lambda 1 plus lambda 2 +plus lambda 3 plus lambda 4 plus 4 right + + align:start position:0% +plus lambda 3 plus lambda 4 plus 4 right + + + align:start position:0% +plus lambda 3 plus lambda 4 plus 4 right +that movement by the identity moved all + + align:start position:0% +that movement by the identity moved all + + + align:start position:0% +that movement by the identity moved all +the eigenvalues by 1 so it moved the + + align:start position:0% +the eigenvalues by 1 so it moved the + + + align:start position:0% +the eigenvalues by 1 so it moved the +whole trace by 4 so that was the trace + + align:start position:0% +whole trace by 4 so that was the trace + + + align:start position:0% +whole trace by 4 so that was the trace +of a plus 4 more ok let's see we may be + + align:start position:0% +of a plus 4 more ok let's see we may be + + + align:start position:0% +of a plus 4 more ok let's see we may be +finished this quiz 20 minutes early nope + + align:start position:0% +finished this quiz 20 minutes early nope + + + align:start position:0% +finished this quiz 20 minutes early nope +there's another question oh god ok how + + align:start position:0% +there's another question oh god ok how + + + align:start position:0% +there's another question oh god ok how +did this class ever do it well you'll + + align:start position:0% +did this class ever do it well you'll + + + align:start position:0% +did this class ever do it well you'll +see you'll see yeah you'll be able to do + + align:start position:0% +see you'll see yeah you'll be able to do + + + align:start position:0% +see you'll see yeah you'll be able to do +it ok + + align:start position:0% +it ok + + + align:start position:0% +it ok +this has got to be a determinate + + align:start position:0% +this has got to be a determinate + + + align:start position:0% +this has got to be a determinate +question all right amaura determinants + + align:start position:0% +question all right amaura determinants + + + align:start position:0% +question all right amaura determinants +and cofactors and big formula question + + align:start position:0% +and cofactors and big formula question + + + align:start position:0% +and cofactors and big formula question +ok let me do that so it's about a matrix + + align:start position:0% +ok let me do that so it's about a matrix + + + align:start position:0% +ok let me do that so it's about a matrix +or a whole family of matrices here's the + + align:start position:0% +or a whole family of matrices here's the + + + align:start position:0% +or a whole family of matrices here's the +4 by 4 1 the 4 by 4 1 is and all the + + align:start position:0% +4 by 4 1 the 4 by 4 1 is and all the + + + align:start position:0% +4 by 4 1 the 4 by 4 1 is and all the +matrices in this family are tridiagonal + + align:start position:0% +matrices in this family are tridiagonal + + + align:start position:0% +matrices in this family are tridiagonal +with with ones otherwise zeros so that's + + align:start position:0% +with with ones otherwise zeros so that's + + + align:start position:0% +with with ones otherwise zeros so that's +the pattern and we've seen this matrix I + + align:start position:0% +the pattern and we've seen this matrix I + + + align:start position:0% +the pattern and we've seen this matrix I +guess + + align:start position:0% +guess + + + align:start position:0% +guess +okay so the it's tridiagonal with ones + + align:start position:0% +okay so the it's tridiagonal with ones + + + align:start position:0% +okay so the it's tridiagonal with ones +on the diagonal ones above and ones + + align:start position:0% +on the diagonal ones above and ones + + + align:start position:0% +on the diagonal ones above and ones +below and you see the general formula am + + align:start position:0% +below and you see the general formula am + + + align:start position:0% +below and you see the general formula am +so I'll use DN for the determinant of a + + align:start position:0% +so I'll use DN for the determinant of a + + + align:start position:0% +so I'll use DN for the determinant of a +and okay alright so I'm gonna do a coke + + align:start position:0% +and okay alright so I'm gonna do a coke + + + align:start position:0% +and okay alright so I'm gonna do a coke +the first question is use cofactors to + + align:start position:0% +the first question is use cofactors to + + + align:start position:0% +the first question is use cofactors to +show that DN is something times DN minus + + align:start position:0% +show that DN is something times DN minus + + + align:start position:0% +show that DN is something times DN minus +one plus something times DN minus two + + align:start position:0% +one plus something times DN minus two + + + align:start position:0% +one plus something times DN minus two +and find those something's okay so this + + align:start position:0% +and find those something's okay so this + + + align:start position:0% +and find those something's okay so this +the fact that it's tri diagonal with + + align:start position:0% +the fact that it's tri diagonal with + + + align:start position:0% +the fact that it's tri diagonal with +these constant diagonals means that + + align:start position:0% +these constant diagonals means that + + + align:start position:0% +these constant diagonals means that +there is such a recurrence formula and + + align:start position:0% +there is such a recurrence formula and + + + align:start position:0% +there is such a recurrence formula and +so the first question is find it what's + + align:start position:0% +so the first question is find it what's + + + align:start position:0% +so the first question is find it what's +the recurrence formula okay how does it + + align:start position:0% +the recurrence formula okay how does it + + + align:start position:0% +the recurrence formula okay how does it +go so I'll use cofactors along the first + + align:start position:0% +go so I'll use cofactors along the first + + + align:start position:0% +go so I'll use cofactors along the first +row so I take that number times its + + align:start position:0% +row so I take that number times its + + + align:start position:0% +row so I take that number times its +cofactor so it's one times its cofactor + + align:start position:0% +cofactor so it's one times its cofactor + + + align:start position:0% +cofactor so it's one times its cofactor +and what is its cofactor DN minus 1 + + align:start position:0% +and what is its cofactor DN minus 1 + + + align:start position:0% +and what is its cofactor DN minus 1 +right exactly the cofactor is this is + + align:start position:0% +right exactly the cofactor is this is + + + align:start position:0% +right exactly the cofactor is this is +that this guy uses up Row one and column + + align:start position:0% +that this guy uses up Row one and column + + + align:start position:0% +that this guy uses up Row one and column +one so the cofactor is down here so it's + + align:start position:0% +one so the cofactor is down here so it's + + + align:start position:0% +one so the cofactor is down here so it's +one of those okay that's the first + + align:start position:0% +one of those okay that's the first + + + align:start position:0% +one of those okay that's the first +cofactor term now the other cofactor + + align:start position:0% +cofactor term now the other cofactor + + + align:start position:0% +cofactor term now the other cofactor +term is this guy which uses up Row one + + align:start position:0% +term is this guy which uses up Row one + + + align:start position:0% +term is this guy which uses up Row one +and column two and what's surprising + + align:start position:0% +and column two and what's surprising + + + align:start position:0% +and column two and what's surprising +about that when you use Row one and + + align:start position:0% +about that when you use Row one and + + + align:start position:0% +about that when you use Row one and +column two that brings in a minus + + align:start position:0% +column two that brings in a minus + + + align:start position:0% +column two that brings in a minus +there'll be a minus because the the + + align:start position:0% +there'll be a minus because the the + + + align:start position:0% +there'll be a minus because the the +cofactor is this determinant times minus + + align:start position:0% +cofactor is this determinant times minus + + + align:start position:0% +cofactor is this determinant times minus +one the the code the one to cofactor is + + align:start position:0% +one the the code the one to cofactor is + + + align:start position:0% +one the the code the one to cofactor is +that determinant with its sign changed + + align:start position:0% +that determinant with its sign changed + + + align:start position:0% +that determinant with its sign changed +okay so I have to look at that + + align:start position:0% +okay so I have to look at that + + + align:start position:0% +okay so I have to look at that +determinant I have to remember in my + + align:start position:0% +determinant I have to remember in my + + + align:start position:0% +determinant I have to remember in my +head a sign is going to get changed okay + + align:start position:0% +head a sign is going to get changed okay + + + align:start position:0% +head a sign is going to get changed okay +now how do I do that determinant how do + + align:start position:0% +now how do I do that determinant how do + + + align:start position:0% +now how do I do that determinant how do +I make that one clear + + align:start position:0% +I make that one clear + + + align:start position:0% +I make that one clear +I the the neat way to do is here I see + + align:start position:0% +I the the neat way to do is here I see + + + align:start position:0% +I the the neat way to do is here I see +I'll use cofactors down the first column + + align:start position:0% +I'll use cofactors down the first column + + + align:start position:0% +I'll use cofactors down the first column +because the first column is all zeros + + align:start position:0% +because the first column is all zeros + + + align:start position:0% +because the first column is all zeros +except for that one so this one is now + + align:start position:0% +except for that one so this one is now + + + align:start position:0% +except for that one so this one is now +and what's its cofactor within this + + align:start position:0% +and what's its cofactor within this + + + align:start position:0% +and what's its cofactor within this +three by three its cofactor will be 2 by + + align:start position:0% +three by three its cofactor will be 2 by + + + align:start position:0% +three by three its cofactor will be 2 by +2 and what is it it's this right so so + + align:start position:0% +2 and what is it it's this right so so + + + align:start position:0% +2 and what is it it's this right so so +that part is all gone so I'm taking that + + align:start position:0% +that part is all gone so I'm taking that + + + align:start position:0% +that part is all gone so I'm taking that +times its cofactor then 0 times whatever + + align:start position:0% +times its cofactor then 0 times whatever + + + align:start position:0% +times its cofactor then 0 times whatever +its cofactor is so it's really just 1 + + align:start position:0% +its cofactor is so it's really just 1 + + + align:start position:0% +its cofactor is so it's really just 1 +times and what's this in the general + + align:start position:0% +times and what's this in the general + + + align:start position:0% +times and what's this in the general +end-by-end case it's D and minus 2 but + + align:start position:0% +end-by-end case it's D and minus 2 but + + + align:start position:0% +end-by-end case it's D and minus 2 but +now + + align:start position:0% +now + + + align:start position:0% +now +so is this a plus or a sign or a minus + + align:start position:0% +so is this a plus or a sign or a minus + + + align:start position:0% +so is this a plus or a sign or a minus +sign it's it's just a 1 because there's + + align:start position:0% +sign it's it's just a 1 because there's + + + align:start position:0% +sign it's it's just a 1 because there's +a 1 from there and a 1 from there and is + + align:start position:0% +a 1 from there and a 1 from there and is + + + align:start position:0% +a 1 from there and a 1 from there and is +it a plus or a minus + + align:start position:0% +it a plus or a minus + + + align:start position:0% +it a plus or a minus +it's - I guess because it was a minus + + align:start position:0% +it's - I guess because it was a minus + + + align:start position:0% +it's - I guess because it was a minus +the first time and then the second time + + align:start position:0% +the first time and then the second time + + + align:start position:0% +the first time and then the second time +it's a plus so it's overall it's a minus + + align:start position:0% +it's a plus so it's overall it's a minus + + + align:start position:0% +it's a plus so it's overall it's a minus +so there's my a and B were 1 and minus 1 + + align:start position:0% +so there's my a and B were 1 and minus 1 + + + align:start position:0% +so there's my a and B were 1 and minus 1 +that was constants that's the that's the + + align:start position:0% +that was constants that's the that's the + + + align:start position:0% +that was constants that's the that's the +recurrence ok and oh then it asks you to + + align:start position:0% +recurrence ok and oh then it asks you to + + + align:start position:0% +recurrence ok and oh then it asks you to +and then it asks you to solve this thing + + align:start position:0% +and then it asks you to solve this thing + + + align:start position:0% +and then it asks you to solve this thing +first by writing it as a as a system so + + align:start position:0% +first by writing it as a as a system so + + + align:start position:0% +first by writing it as a as a system so +now I'd like to know these solution I + + align:start position:0% +now I'd like to know these solution I + + + align:start position:0% +now I'd like to know these solution I +better know how it starts right + + align:start position:0% +better know how it starts right + + + align:start position:0% +better know how it starts right +it starts with D 1 what was D 1 that's + + align:start position:0% +it starts with D 1 what was D 1 that's + + + align:start position:0% +it starts with D 1 what was D 1 that's +just a one by one case so D 1 is 1 and + + align:start position:0% +just a one by one case so D 1 is 1 and + + + align:start position:0% +just a one by one case so D 1 is 1 and +what is d 2 just to get us started and + + align:start position:0% +what is d 2 just to get us started and + + + align:start position:0% +what is d 2 just to get us started and +then this would give us d3 d4 and + + align:start position:0% +then this would give us d3 d4 and + + + align:start position:0% +then this would give us d3 d4 and +forever D 2 is this 2 by 2 that I'm + + align:start position:0% +forever D 2 is this 2 by 2 that I'm + + + align:start position:0% +forever D 2 is this 2 by 2 that I'm +seeing here and that determinant is + + align:start position:0% +seeing here and that determinant is + + + align:start position:0% +seeing here and that determinant is +obviously 0 so those little ones will + + align:start position:0% +obviously 0 so those little ones will + + + align:start position:0% +obviously 0 so those little ones will +start the recurrence and then we take + + align:start position:0% +start the recurrence and then we take + + + align:start position:0% +start the recurrence and then we take +off and then the idea is to write this + + align:start position:0% +off and then the idea is to write this + + + align:start position:0% +off and then the idea is to write this +recurrence as a as a DND n minus 1 is + + align:start position:0% +recurrence as a as a DND n minus 1 is + + + align:start position:0% +recurrence as a as a DND n minus 1 is +some matrix times + + align:start position:0% + + + + align:start position:0% + +the one before the DN minus 1 DN minus 2 + + align:start position:0% + + + + align:start position:0% + +what's the matrix you see you remember + + align:start position:0% +what's the matrix you see you remember + + + align:start position:0% +what's the matrix you see you remember +this step of taking a single + + align:start position:0% +this step of taking a single + + + align:start position:0% +this step of taking a single +second-order equation and by introducing + + align:start position:0% +second-order equation and by introducing + + + align:start position:0% +second-order equation and by introducing +a vector unknown to make it into a to a + + align:start position:0% +a vector unknown to make it into a to a + + + align:start position:0% +a vector unknown to make it into a to a +first-order system okay + + align:start position:0% +first-order system okay + + + align:start position:0% +first-order system okay +so DN is one of DN minus 1 minus 1 I + + align:start position:0% +so DN is one of DN minus 1 minus 1 I + + + align:start position:0% +so DN is one of DN minus 1 minus 1 I +think that that goes in the first row + + align:start position:0% +think that that goes in the first row + + + align:start position:0% +think that that goes in the first row +right from the equation above and the + + align:start position:0% +right from the equation above and the + + + align:start position:0% +right from the equation above and the +second one is this is the same as this + + align:start position:0% +second one is this is the same as this + + + align:start position:0% +second one is this is the same as this +so 1 and 0 are fine so there's the + + align:start position:0% +so 1 and 0 are fine so there's the + + + align:start position:0% +so 1 and 0 are fine so there's the +matrix ok so now how do I proceed we can + + align:start position:0% +matrix ok so now how do I proceed we can + + + align:start position:0% +matrix ok so now how do I proceed we can +guess what this examiner's got in his + + align:start position:0% +guess what this examiner's got in his + + + align:start position:0% +guess what this examiner's got in his +little mind well find the eigenvalues + + align:start position:0% +little mind well find the eigenvalues + + + align:start position:0% +little mind well find the eigenvalues +and actually it tells us that the sixth + + align:start position:0% +and actually it tells us that the sixth + + + align:start position:0% +and actually it tells us that the sixth +power of these eigenvalues turns out to + + align:start position:0% +power of these eigenvalues turns out to + + + align:start position:0% +power of these eigenvalues turns out to +be 1 well can can we get the equation + + align:start position:0% +be 1 well can can we get the equation + + + align:start position:0% +be 1 well can can we get the equation +for the eigenvalues let's do it and + + align:start position:0% +for the eigenvalues let's do it and + + + align:start position:0% +for the eigenvalues let's do it and +let's get a formula for them okay so + + align:start position:0% +let's get a formula for them okay so + + + align:start position:0% +let's get a formula for them okay so +what are the eigenvalues I look at the + + align:start position:0% +what are the eigenvalues I look at the + + + align:start position:0% +what are the eigenvalues I look at the +the matrix this determinant 1 minus + + align:start position:0% +the matrix this determinant 1 minus + + + align:start position:0% +the matrix this determinant 1 minus +lambda and 0 minus lambda and these guys + + align:start position:0% +lambda and 0 minus lambda and these guys + + + align:start position:0% +lambda and 0 minus lambda and these guys +are still there i compute that + + align:start position:0% +are still there i compute that + + + align:start position:0% +are still there i compute that +determinant I get lambda squared minus + + align:start position:0% +determinant I get lambda squared minus + + + align:start position:0% +determinant I get lambda squared minus +lambda and then plus 1 and I set that to + + align:start position:0% +lambda and then plus 1 and I set that to + + + align:start position:0% +lambda and then plus 1 and I set that to +0 okay so we're not Fibonacci here we're + + align:start position:0% +0 okay so we're not Fibonacci here we're + + + align:start position:0% +0 okay so we're not Fibonacci here we're +not seeing Fibonacci numbers because the + + align:start position:0% +not seeing Fibonacci numbers because the + + + align:start position:0% +not seeing Fibonacci numbers because the +sine we had a sign change there and it's + + align:start position:0% +sine we had a sign change there and it's + + + align:start position:0% +sine we had a sign change there and it's +not clear right away whether these + + align:start position:0% +not clear right away whether these + + + align:start position:0% +not clear right away whether these +whether this is it clear is this matrix + + align:start position:0% +whether this is it clear is this matrix + + + align:start position:0% +whether this is it clear is this matrix +stable or unstable when we take when we + + align:start position:0% +stable or unstable when we take when we + + + align:start position:0% +stable or unstable when we take when we +go further and further out are these D + + align:start position:0% +go further and further out are these D + + + align:start position:0% +go further and further out are these D +is increasing are they going to zero are + + align:start position:0% +is increasing are they going to zero are + + + align:start position:0% +is increasing are they going to zero are +they bouncing around periodically the + + align:start position:0% +they bouncing around periodically the + + + align:start position:0% +they bouncing around periodically the +answers have to be here I I would like + + align:start position:0% +answers have to be here I I would like + + + align:start position:0% +answers have to be here I I would like +to know how big these lambdas are right + + align:start position:0% +to know how big these lambdas are right + + + align:start position:0% +to know how big these lambdas are right +and the point is probably these let's + + align:start position:0% +and the point is probably these let's + + + align:start position:0% +and the point is probably these let's +let's see what's lambda from the + + align:start position:0% +let's see what's lambda from the + + + align:start position:0% +let's see what's lambda from the +quadratic formula lambda is one I + + align:start position:0% +quadratic formula lambda is one I + + + align:start position:0% +quadratic formula lambda is one I +switched the sign of that plus or minus + + align:start position:0% +switched the sign of that plus or minus + + + align:start position:0% +switched the sign of that plus or minus +the square root of one minus 4ac am I + + align:start position:0% +the square root of one minus 4ac am I + + + align:start position:0% +the square root of one minus 4ac am I +getting a minus three there / - what's + + align:start position:0% +getting a minus three there / - what's + + + align:start position:0% +getting a minus three there / - what's +up there complex the eigenvalues are 1 + + align:start position:0% +up there complex the eigenvalues are 1 + + + align:start position:0% +up there complex the eigenvalues are 1 +plus square root of 3i over 2 and 1 + + align:start position:0% +plus square root of 3i over 2 and 1 + + + align:start position:0% +plus square root of 3i over 2 and 1 +minus square root of 3i over 2 what's + + align:start position:0% +minus square root of 3i over 2 what's + + + align:start position:0% +minus square root of 3i over 2 what's +the magnitude of lambda that's the key + + align:start position:0% +the magnitude of lambda that's the key + + + align:start position:0% +the magnitude of lambda that's the key +point for stability these these these + + align:start position:0% +point for stability these these these + + + align:start position:0% +point for stability these these these +are two numbers in the complex plane 1 + + align:start position:0% +are two numbers in the complex plane 1 + + + align:start position:0% +are two numbers in the complex plane 1 +plus some somewhere here and it's + + align:start position:0% +plus some somewhere here and it's + + + align:start position:0% +plus some somewhere here and it's +complex conjugate there I want to know + + align:start position:0% +complex conjugate there I want to know + + + align:start position:0% +complex conjugate there I want to know +how far from the origin are those + + align:start position:0% +how far from the origin are those + + + align:start position:0% +how far from the origin are those +numbers what's the magnitude of lambda + + align:start position:0% +numbers what's the magnitude of lambda + + + align:start position:0% +numbers what's the magnitude of lambda +and you see what it is + + align:start position:0% +and you see what it is + + + align:start position:0% +and you see what it is +you recognize this a number like that + + align:start position:0% +you recognize this a number like that + + + align:start position:0% +you recognize this a number like that +take the real part squared and the + + align:start position:0% +take the real part squared and the + + + align:start position:0% +take the real part squared and the +imaginary part squared and add what do + + align:start position:0% +imaginary part squared and add what do + + + align:start position:0% +imaginary part squared and add what do +you get so the real part squared is of + + align:start position:0% +you get so the real part squared is of + + + align:start position:0% +you get so the real part squared is of +quarter the imaginary part squared is + + align:start position:0% +quarter the imaginary part squared is + + + align:start position:0% +quarter the imaginary part squared is +3/4 they add to 1 that's a number with + + align:start position:0% +3/4 they add to 1 that's a number with + + + align:start position:0% +3/4 they add to 1 that's a number with +that's on the unit circle that's an e to + + align:start position:0% +that's on the unit circle that's an e to + + + align:start position:0% +that's on the unit circle that's an e to +the I theta + + align:start position:0% +the I theta + + + align:start position:0% +the I theta +that's a cos theta plus I sine theta and + + align:start position:0% +that's a cos theta plus I sine theta and + + + align:start position:0% +that's a cos theta plus I sine theta and +what's theta is so this this is like a + + align:start position:0% +what's theta is so this this is like a + + + align:start position:0% +what's theta is so this this is like a +complex number that's worth knowing it's + + align:start position:0% +complex number that's worth knowing it's + + + align:start position:0% +complex number that's worth knowing it's +not totally obvious but it's nice that's + + align:start position:0% +not totally obvious but it's nice that's + + + align:start position:0% +not totally obvious but it's nice that's +that I should see that as cos theta plus + + align:start position:0% +that I should see that as cos theta plus + + + align:start position:0% +that I should see that as cos theta plus +I sine theta and the angle that would do + + align:start position:0% +I sine theta and the angle that would do + + + align:start position:0% +I sine theta and the angle that would do +that is 60 degrees PI over 3 so that's a + + align:start position:0% +that is 60 degrees PI over 3 so that's a + + + align:start position:0% +that is 60 degrees PI over 3 so that's a +let me improve my picture + + align:start position:0% +let me improve my picture + + + align:start position:0% +let me improve my picture +so those that's e to the I PI over six + + align:start position:0% +so those that's e to the I PI over six + + + align:start position:0% +so those that's e to the I PI over six +be PI over three + + align:start position:0% +be PI over three + + + align:start position:0% +be PI over three +this is this number is e to the I PI + + align:start position:0% +this is this number is e to the I PI + + + align:start position:0% +this is this number is e to the I PI +over three and he to the minus I PI over + + align:start position:0% +over three and he to the minus I PI over + + + align:start position:0% +over three and he to the minus I PI over +three will be doing more complex numbers + + align:start position:0% +three will be doing more complex numbers + + + align:start position:0% +three will be doing more complex numbers +briefly but a little more in the next + + align:start position:0% +briefly but a little more in the next + + + align:start position:0% +briefly but a little more in the next +two days next two lectures anyway so + + align:start position:0% +two days next two lectures anyway so + + + align:start position:0% +two days next two lectures anyway so +what's the deal with stability what do + + align:start position:0% +what's the deal with stability what do + + + align:start position:0% +what's the deal with stability what do +the d-ends do well look if if I take the + + align:start position:0% +the d-ends do well look if if I take the + + + align:start position:0% +the d-ends do well look if if I take the +sixth power I'm around at 1 the problem + + align:start position:0% +sixth power I'm around at 1 the problem + + + align:start position:0% +sixth power I'm around at 1 the problem +actually told me this the sixth power of + + align:start position:0% +actually told me this the sixth power of + + + align:start position:0% +actually told me this the sixth power of +those eigenvalues brings me around to 1 + + align:start position:0% +those eigenvalues brings me around to 1 + + + align:start position:0% +those eigenvalues brings me around to 1 +what does that tell you about the matrix + + align:start position:0% +what does that tell you about the matrix + + + align:start position:0% +what does that tell you about the matrix +by the way suppose you know this was a + + align:start position:0% +by the way suppose you know this was a + + + align:start position:0% +by the way suppose you know this was a +great quiz question so I should never + + align:start position:0% +great quiz question so I should never + + + align:start position:0% +great quiz question so I should never +have just said it but popped out suppose + + align:start position:0% +have just said it but popped out suppose + + + align:start position:0% +have just said it but popped out suppose +lambda 1 to the sixth and lambda 2 to + + align:start position:0% +lambda 1 to the sixth and lambda 2 to + + + align:start position:0% +lambda 1 to the sixth and lambda 2 to +the sixth or 1 which they are what does + + align:start position:0% +the sixth or 1 which they are what does + + + align:start position:0% +the sixth or 1 which they are what does +that tell me about a matrix about my + + align:start position:0% +that tell me about a matrix about my + + + align:start position:0% +that tell me about a matrix about my +matrix a here well what what matrix is + + align:start position:0% +matrix a here well what what matrix is + + + align:start position:0% +matrix a here well what what matrix is +connected with lambda 1 to the sixth and + + align:start position:0% +connected with lambda 1 to the sixth and + + + align:start position:0% +connected with lambda 1 to the sixth and +lambda 2 to the 6 it's got to be the + + align:start position:0% +lambda 2 to the 6 it's got to be the + + + align:start position:0% +lambda 2 to the 6 it's got to be the +matrix a to the sixth so what is a to + + align:start position:0% +matrix a to the sixth so what is a to + + + align:start position:0% +matrix a to the sixth so what is a to +the sixth for that matrix it's got I + + align:start position:0% +the sixth for that matrix it's got I + + + align:start position:0% +the sixth for that matrix it's got I +ghen values one in one cuz when I take + + align:start position:0% +ghen values one in one cuz when I take + + + align:start position:0% +ghen values one in one cuz when I take +the sixth power actually yeah if I take + + align:start position:0% +the sixth power actually yeah if I take + + + align:start position:0% +the sixth power actually yeah if I take +the sixth power both all the sixth power + + align:start position:0% +the sixth power both all the sixth power + + + align:start position:0% +the sixth power both all the sixth power +of that is one and the sixth power of + + align:start position:0% +of that is one and the sixth power of + + + align:start position:0% +of that is one and the sixth power of +that is one the sixth power of this is e + + align:start position:0% +that is one the sixth power of this is e + + + align:start position:0% +that is one the sixth power of this is e +to the 2 pi that's one the sixth power + + align:start position:0% +to the 2 pi that's one the sixth power + + + align:start position:0% +to the 2 pi that's one the sixth power +of this is e to the minus 2 pi that's + + align:start position:0% +of this is e to the minus 2 pi that's + + + align:start position:0% +of this is e to the minus 2 pi that's +one so the sixth powers the the 6th + + align:start position:0% +one so the sixth powers the the 6th + + + align:start position:0% +one so the sixth powers the the 6th +power of that matrix has eigenvalues one + + align:start position:0% +power of that matrix has eigenvalues one + + + align:start position:0% +power of that matrix has eigenvalues one +and one so what is it it's the identity + + align:start position:0% +and one so what is it it's the identity + + + align:start position:0% +and one so what is it it's the identity +right so if I operate this if I run this + + align:start position:0% +right so if I operate this if I run this + + + align:start position:0% +right so if I operate this if I run this +thing six times I'm back where I was the + + align:start position:0% +thing six times I'm back where I was the + + + align:start position:0% +thing six times I'm back where I was the +sixth power of that matrix is the + + align:start position:0% +sixth power of that matrix is the + + + align:start position:0% +sixth power of that matrix is the +identity good okay so it'll loop around + + align:start position:0% +identity good okay so it'll loop around + + + align:start position:0% +identity good okay so it'll loop around +it's it doesn't go to zero it doesn't + + align:start position:0% +it's it doesn't go to zero it doesn't + + + align:start position:0% +it's it doesn't go to zero it doesn't +blow up it just periodically goes around + + align:start position:0% +blow up it just periodically goes around + + + align:start position:0% +blow up it just periodically goes around +with period six okay + + align:start position:0% +with period six okay + + + align:start position:0% +with period six okay +let's just see if there's a alright + + align:start position:0% +let's just see if there's a alright + + + align:start position:0% +let's just see if there's a alright +oh let's see can I also look at a at a + + align:start position:0% +oh let's see can I also look at a at a + + + align:start position:0% +oh let's see can I also look at a at a +final exam from 1992 I think that's yeah + + align:start position:0% +final exam from 1992 I think that's yeah + + + align:start position:0% +final exam from 1992 I think that's yeah +let me do that on this last board it + + align:start position:0% +let me do that on this last board it + + + align:start position:0% +let me do that on this last board it +starts a lot of the questions in this + + align:start position:0% +starts a lot of the questions in this + + + align:start position:0% +starts a lot of the questions in this +exam are about a family of matrices let + + align:start position:0% +exam are about a family of matrices let + + + align:start position:0% +exam are about a family of matrices let +me give you the fourth the fourth guy in + + align:start position:0% +me give you the fourth the fourth guy in + + + align:start position:0% +me give you the fourth the fourth guy in +the family is has a 1 so it's zeros on + + align:start position:0% +the family is has a 1 so it's zeros on + + + align:start position:0% +the family is has a 1 so it's zeros on +the diagonal but these are going 1 2 3 + + align:start position:0% +the diagonal but these are going 1 2 3 + + + align:start position:0% +the diagonal but these are going 1 2 3 +and so on 1 2 3 and so on + + align:start position:0% +and so on 1 2 3 and so on + + + align:start position:0% +and so on 1 2 3 and so on +but for the 4 by 4 case I'm stopping at + + align:start position:0% +but for the 4 by 4 case I'm stopping at + + + align:start position:0% +but for the 4 by 4 case I'm stopping at +4 you see the pattern it's it's a family + + align:start position:0% +4 you see the pattern it's it's a family + + + align:start position:0% +4 you see the pattern it's it's a family +of matrices which is growing and + + align:start position:0% +of matrices which is growing and + + + align:start position:0% +of matrices which is growing and +actually the numbers it's symmetric + + align:start position:0% +actually the numbers it's symmetric + + + align:start position:0% +actually the numbers it's symmetric +right it's equal to a for transpose and + + align:start position:0% +right it's equal to a for transpose and + + + align:start position:0% +right it's equal to a for transpose and +we can ask all sorts of questions about + + align:start position:0% +we can ask all sorts of questions about + + + align:start position:0% +we can ask all sorts of questions about +its null space its range its column + + align:start position:0% +its null space its range its column + + + align:start position:0% +its null space its range its column +space find the projection matrix under + + align:start position:0% +space find the projection matrix under + + + align:start position:0% +space find the projection matrix under +the column space of a 3 for example is + + align:start position:0% +the column space of a 3 for example is + + + align:start position:0% +the column space of a 3 for example is +in here so so one so a 3 is 0 1 0 1 0 2 + + align:start position:0% +in here so so one so a 3 is 0 1 0 1 0 2 + + + align:start position:0% +in here so so one so a 3 is 0 1 0 1 0 2 +0 2 0 + + align:start position:0% + + + + align:start position:0% + +okay find the projection matrix onto the + + align:start position:0% +okay find the projection matrix onto the + + + align:start position:0% +okay find the projection matrix onto the +column space by the way is that matrix + + align:start position:0% +column space by the way is that matrix + + + align:start position:0% +column space by the way is that matrix +singular or invertible singular why do + + align:start position:0% +singular or invertible singular why do + + + align:start position:0% +singular or invertible singular why do +we know it's singular + + align:start position:0% +we know it's singular + + + align:start position:0% +we know it's singular +I see the column three is a cut is a + + align:start position:0% +I see the column three is a cut is a + + + align:start position:0% +I see the column three is a cut is a +multiple of column one or we could take + + align:start position:0% +multiple of column one or we could take + + + align:start position:0% +multiple of column one or we could take +its determinant so it's certainly + + align:start position:0% +its determinant so it's certainly + + + align:start position:0% +its determinant so it's certainly +singular the project so the projection + + align:start position:0% +singular the project so the projection + + + align:start position:0% +singular the project so the projection +will be matrix will be three by three + + align:start position:0% +will be matrix will be three by three + + + align:start position:0% +will be matrix will be three by three +but it will project onto the column + + align:start position:0% +but it will project onto the column + + + align:start position:0% +but it will project onto the column +space it'll project onto this plane the + + align:start position:0% +space it'll project onto this plane the + + + align:start position:0% +space it'll project onto this plane the +column space of a three and I guess I + + align:start position:0% +column space of a three and I guess I + + + align:start position:0% +column space of a three and I guess I +would find it from the formula a eight a + + align:start position:0% +would find it from the formula a eight a + + + align:start position:0% +would find it from the formula a eight a +a transpose a inverse I would have to I + + align:start position:0% +a transpose a inverse I would have to I + + + align:start position:0% +a transpose a inverse I would have to I +would I guess I would do all this there + + align:start position:0% +would I guess I would do all this there + + + align:start position:0% +would I guess I would do all this there +may be a better way perhaps like yeah I + + align:start position:0% +may be a better way perhaps like yeah I + + + align:start position:0% +may be a better way perhaps like yeah I +could think there might be a slightly + + align:start position:0% +could think there might be a slightly + + + align:start position:0% +could think there might be a slightly +quicker way but that would come out + + align:start position:0% +quicker way but that would come out + + + align:start position:0% +quicker way but that would come out +pretty fast okay so that's me the + + align:start position:0% +pretty fast okay so that's me the + + + align:start position:0% +pretty fast okay so that's me the +projection matrix + + align:start position:0% +projection matrix + + + align:start position:0% +projection matrix +next question find the eigenvalues and + + align:start position:0% +next question find the eigenvalues and + + + align:start position:0% +next question find the eigenvalues and +eigenvectors of that matrix okay there's + + align:start position:0% +eigenvectors of that matrix okay there's + + + align:start position:0% +eigenvectors of that matrix okay there's +a three by three matrix oh yes so what + + align:start position:0% +a three by three matrix oh yes so what + + + align:start position:0% +a three by three matrix oh yes so what +are its eigenvalues and eigenvectors we + + align:start position:0% +are its eigenvalues and eigenvectors we + + + align:start position:0% +are its eigenvalues and eigenvectors we +haven't done any three by threes let's + + align:start position:0% +haven't done any three by threes let's + + + align:start position:0% +haven't done any three by threes let's +do one I want to find so how do I find + + align:start position:0% +do one I want to find so how do I find + + + align:start position:0% +do one I want to find so how do I find +eigenvalues I take the determinant of a + + align:start position:0% +eigenvalues I take the determinant of a + + + align:start position:0% +eigenvalues I take the determinant of a +3 minus lambda hi so this is you just + + align:start position:0% +3 minus lambda hi so this is you just + + + align:start position:0% +3 minus lambda hi so this is you just +have to so I'm subtracting lambda from + + align:start position:0% +have to so I'm subtracting lambda from + + + align:start position:0% +have to so I'm subtracting lambda from +the diagonal and I have a 1 1 0 0 2 2 + + align:start position:0% +the diagonal and I have a 1 1 0 0 2 2 + + + align:start position:0% +the diagonal and I have a 1 1 0 0 2 2 +there and I just have to find that + + align:start position:0% +there and I just have to find that + + + align:start position:0% +there and I just have to find that +determinant okay since it's 3x3 I'll + + align:start position:0% +determinant okay since it's 3x3 I'll + + + align:start position:0% +determinant okay since it's 3x3 I'll +just go for it this way gives me minus + + align:start position:0% +just go for it this way gives me minus + + + align:start position:0% +just go for it this way gives me minus +lambda cubed and a 0 and a 0 then in + + align:start position:0% +lambda cubed and a 0 and a 0 then in + + + align:start position:0% +lambda cubed and a 0 and a 0 then in +this direction which has the minus sign + + align:start position:0% +this direction which has the minus sign + + + align:start position:0% +this direction which has the minus sign +that's a zero for lambdas i mean- for + + align:start position:0% +that's a zero for lambdas i mean- for + + + align:start position:0% +that's a zero for lambdas i mean- for +lambdas and - another lambda so that's + + align:start position:0% +lambdas and - another lambda so that's + + + align:start position:0% +lambdas and - another lambda so that's +-5 lambdas but that direction goes with + + align:start position:0% +-5 lambdas but that direction goes with + + + align:start position:0% +-5 lambdas but that direction goes with +a minus sign so I think it's plus 5 + + align:start position:0% +a minus sign so I think it's plus 5 + + + align:start position:0% +a minus sign so I think it's plus 5 +lambda that looks like the determinant + + align:start position:0% +lambda that looks like the determinant + + + align:start position:0% +lambda that looks like the determinant +of a 3 minus lambda I so I set it to 0 + + align:start position:0% +of a 3 minus lambda I so I set it to 0 + + + align:start position:0% +of a 3 minus lambda I so I set it to 0 +so what are the eigenvalues + + align:start position:0% +so what are the eigenvalues + + + align:start position:0% +so what are the eigenvalues +well lambda equals 0 lambda factors out + + align:start position:0% +well lambda equals 0 lambda factors out + + + align:start position:0% +well lambda equals 0 lambda factors out +of this times minus lambda squared plus + + align:start position:0% +of this times minus lambda squared plus + + + align:start position:0% +of this times minus lambda squared plus +4 so the eigenvalues are 5 thanks thanks + + align:start position:0% +4 so the eigenvalues are 5 thanks thanks + + + align:start position:0% +4 so the eigenvalues are 5 thanks thanks +so the eigenvalues are 0 square root of + + align:start position:0% +so the eigenvalues are 0 square root of + + + align:start position:0% +so the eigenvalues are 0 square root of +5 and minus square root of 5 and I would + + align:start position:0% +5 and minus square root of 5 and I would + + + align:start position:0% +5 and minus square root of 5 and I would +never write down those three eigenvalues + + align:start position:0% +never write down those three eigenvalues + + + align:start position:0% +never write down those three eigenvalues +without checking the trace to tell the + + align:start position:0% +without checking the trace to tell the + + + align:start position:0% +without checking the trace to tell the +truth because because we did a bunch of + + align:start position:0% +truth because because we did a bunch of + + + align:start position:0% +truth because because we did a bunch of +calculations here but then I can quickly + + align:start position:0% +calculations here but then I can quickly + + + align:start position:0% +calculations here but then I can quickly +add up the eigenvalues to get 0 add up + + align:start position:0% +add up the eigenvalues to get 0 add up + + + align:start position:0% +add up the eigenvalues to get 0 add up +the trace to get 0 and feel that I'm + + align:start position:0% +the trace to get 0 and feel that I'm + + + align:start position:0% +the trace to get 0 and feel that I'm +well I guess that wouldn't have caught + + align:start position:0% +well I guess that wouldn't have caught + + + align:start position:0% +well I guess that wouldn't have caught +my error if I made it if that had been a + + align:start position:0% +my error if I made it if that had been a + + + align:start position:0% +my error if I made it if that had been a +4 I wouldn't have noticed the + + align:start position:0% +4 I wouldn't have noticed the + + + align:start position:0% +4 I wouldn't have noticed the +determinant isn't anything greatly + + align:start position:0% +determinant isn't anything greatly + + + align:start position:0% +determinant isn't anything greatly +useful here right because the + + align:start position:0% +useful here right because the + + + align:start position:0% +useful here right because the +determinant is just 0 and so I never + + align:start position:0% +determinant is just 0 and so I never + + + align:start position:0% +determinant is just 0 and so I never +would know whether that 5 was right or + + align:start position:0% +would know whether that 5 was right or + + + align:start position:0% +would know whether that 5 was right or +wrong but thanks for making it right ok + + align:start position:0% + + + + align:start position:0% + +huh question to see whoever wrote this + + align:start position:0% +huh question to see whoever wrote this + + + align:start position:0% +huh question to see whoever wrote this +probably me said this is not difficult I + + align:start position:0% +probably me said this is not difficult I + + + align:start position:0% +probably me said this is not difficult I +don't know why I put that in it asks for + + align:start position:0% +don't know why I put that in it asks for + + + align:start position:0% +don't know why I put that in it asks for +the projection matrix onto the column + + align:start position:0% +the projection matrix onto the column + + + align:start position:0% +the projection matrix onto the column +space of a 4 how could I have thought + + align:start position:0% +space of a 4 how could I have thought + + + align:start position:0% +space of a 4 how could I have thought +that wasn't difficult it looks extremely + + align:start position:0% +that wasn't difficult it looks extremely + + + align:start position:0% +that wasn't difficult it looks extremely +difficult what's the projection matrix + + align:start position:0% +difficult what's the projection matrix + + + align:start position:0% +difficult what's the projection matrix +under the column space of a 4 I don't + + align:start position:0% +under the column space of a 4 I don't + + + align:start position:0% +under the column space of a 4 I don't +know whether that this is now difficult + + align:start position:0% +know whether that this is now difficult + + + align:start position:0% +know whether that this is now difficult +it's just like helpful or or insulting + + align:start position:0% + + + + align:start position:0% + +and what do you think there what's the + + align:start position:0% +and what do you think there what's the + + + align:start position:0% +and what do you think there what's the +column space of a 4 here well what's our + + align:start position:0% +column space of a 4 here well what's our + + + align:start position:0% +column space of a 4 here well what's our +first question is is the matrix singular + + align:start position:0% +first question is is the matrix singular + + + align:start position:0% +first question is is the matrix singular +or invertible if the answer is + + align:start position:0% +or invertible if the answer is + + + align:start position:0% +or invertible if the answer is +invertible then what's the column space + + align:start position:0% +invertible then what's the column space + + + align:start position:0% +invertible then what's the column space +if this matrix a for is invertible so + + align:start position:0% +if this matrix a for is invertible so + + + align:start position:0% +if this matrix a for is invertible so +that's my guess if this problem is easy + + align:start position:0% +that's my guess if this problem is easy + + + align:start position:0% +that's my guess if this problem is easy +it has to be because this matrix is + + align:start position:0% +it has to be because this matrix is + + + align:start position:0% +it has to be because this matrix is +probably invertible then it's column + + align:start position:0% +probably invertible then it's column + + + align:start position:0% +probably invertible then it's column +spaces are for good column spaces the + + align:start position:0% +spaces are for good column spaces the + + + align:start position:0% +spaces are for good column spaces the +whole space and the answer to this easy + + align:start position:0% +whole space and the answer to this easy + + + align:start position:0% +whole space and the answer to this easy +question is the projection matrix is the + + align:start position:0% +question is the projection matrix is the + + + align:start position:0% +question is the projection matrix is the +identity it's the 4 by 4 identity matrix + + align:start position:0% +identity it's the 4 by 4 identity matrix + + + align:start position:0% +identity it's the 4 by 4 identity matrix +if this matrix is invertible shall we + + align:start position:0% +if this matrix is invertible shall we + + + align:start position:0% +if this matrix is invertible shall we +check invertibility how would you find + + align:start position:0% +check invertibility how would you find + + + align:start position:0% +check invertibility how would you find +its determinant can we just like take + + align:start position:0% +its determinant can we just like take + + + align:start position:0% +its determinant can we just like take +the determinant of that matrix I could + + align:start position:0% +the determinant of that matrix I could + + + align:start position:0% +the determinant of that matrix I could +ask you how so there there are 24 terms + + align:start position:0% +ask you how so there there are 24 terms + + + align:start position:0% +ask you how so there there are 24 terms +do we want to write all 24 terms down + + align:start position:0% +do we want to write all 24 terms down + + + align:start position:0% +do we want to write all 24 terms down +not in the remaining 10 seconds better + + align:start position:0% +not in the remaining 10 seconds better + + + align:start position:0% +not in the remaining 10 seconds better +to use cofactors so I go along Row 1 I + + align:start position:0% +to use cofactors so I go along Row 1 I + + + align:start position:0% +to use cofactors so I go along Row 1 I +see one the only nonzero is this guy so + + align:start position:0% +see one the only nonzero is this guy so + + + align:start position:0% +see one the only nonzero is this guy so +I should take that 1 times the cofactor + + align:start position:0% +I should take that 1 times the cofactor + + + align:start position:0% +I should take that 1 times the cofactor +now so I'm down to this determinant okay + + align:start position:0% +now so I'm down to this determinant okay + + + align:start position:0% +now so I'm down to this determinant okay +so now I'm look at this for his column I + + align:start position:0% +so now I'm look at this for his column I + + + align:start position:0% +so now I'm look at this for his column I +see 1 times this there's the cofactor of + + align:start position:0% +see 1 times this there's the cofactor of + + + align:start position:0% +see 1 times this there's the cofactor of +the one so I'm using up Row 1 Row 1 and + + align:start position:0% +the one so I'm using up Row 1 Row 1 and + + + align:start position:0% +the one so I'm using up Row 1 Row 1 and +column 1 of this 3 by 3 matrix I'm down + + align:start position:0% +column 1 of this 3 by 3 matrix I'm down + + + align:start position:0% +column 1 of this 3 by 3 matrix I'm down +to this cofactor and by the way those + + align:start position:0% +to this cofactor and by the way those + + + align:start position:0% +to this cofactor and by the way those +were both plus signs right no they + + align:start position:0% +were both plus signs right no they + + + align:start position:0% +were both plus signs right no they +weren't that was a minus sign that was a + + align:start position:0% +weren't that was a minus sign that was a + + + align:start position:0% +weren't that was a minus sign that was a +that was a minus and then that was a + + align:start position:0% +that was a minus and then that was a + + + align:start position:0% +that was a minus and then that was a +plus and then this so what's the + + align:start position:0% +plus and then this so what's the + + + align:start position:0% +plus and then this so what's the +determinant 9 no determinate is not the + + align:start position:0% +determinant 9 no determinate is not the + + + align:start position:0% +determinant 9 no determinate is not the +determinate of a for is not okay where a + + align:start position:0% +determinate of a for is not okay where a + + + align:start position:0% +determinate of a for is not okay where a +3 so my guess is I'll put that on the + + align:start position:0% +3 so my guess is I'll put that on the + + + align:start position:0% +3 so my guess is I'll put that on the +final this year the probably the + + align:start position:0% +final this year the probably the + + + align:start position:0% +final this year the probably the +odd-numbered ones are singular and the + + align:start position:0% +odd-numbered ones are singular and the + + + align:start position:0% +odd-numbered ones are singular and the +even-numbered ones are invertible and I + + align:start position:0% +even-numbered ones are invertible and I + + + align:start position:0% +even-numbered ones are invertible and I +don't know what the determinants are but + + align:start position:0% +don't know what the determinants are but + + + align:start position:0% +don't know what the determinants are but +I'm betting that they have some nice + + align:start position:0% +I'm betting that they have some nice + + + align:start position:0% +I'm betting that they have some nice +formula okay so recitations this week + + align:start position:0% +formula okay so recitations this week + + + align:start position:0% +formula okay so recitations this week +will also be quiz review and then the + + align:start position:0% +will also be quiz review and then the + + + align:start position:0% +will also be quiz review and then the +quiz is Wednesday at 1 o'clock thanks \ No newline at end of file diff --git a/R4nGGs0m7lo.txt b/R4nGGs0m7lo.txt new file mode 100644 index 0000000000000000000000000000000000000000..03d931671824cdf65108cf9bc20285ee77c89bf3 --- /dev/null +++ b/R4nGGs0m7lo.txt @@ -0,0 +1,571 @@ +align:start position:0% + +when we have independence does anything + + align:start position:0% +when we have independence does anything + + + align:start position:0% +when we have independence does anything +interesting happen to expectations we + + align:start position:0% +interesting happen to expectations we + + + align:start position:0% +interesting happen to expectations we +know that in general the expected value + + align:start position:0% +know that in general the expected value + + + align:start position:0% +know that in general the expected value +of a function of random variables is not + + align:start position:0% +of a function of random variables is not + + + align:start position:0% +of a function of random variables is not +the same as applying the function to the + + align:start position:0% +the same as applying the function to the + + + align:start position:0% +the same as applying the function to the +expected values and we also know that + + align:start position:0% +expected values and we also know that + + + align:start position:0% +expected values and we also know that +there are some exceptions where we do + + align:start position:0% +there are some exceptions where we do + + + align:start position:0% +there are some exceptions where we do +get equality this is the case where we + + align:start position:0% +get equality this is the case where we + + + align:start position:0% +get equality this is the case where we +are dealing with linear functions of one + + align:start position:0% +are dealing with linear functions of one + + + align:start position:0% +are dealing with linear functions of one +or more random variables + + align:start position:0% +or more random variables + + + align:start position:0% +or more random variables +note that this last property is always + + align:start position:0% +note that this last property is always + + + align:start position:0% +note that this last property is always +true and does not require any + + align:start position:0% +true and does not require any + + + align:start position:0% +true and does not require any +independence assumptions when we have + + align:start position:0% +independence assumptions when we have + + + align:start position:0% +independence assumptions when we have +independence there is one additional + + align:start position:0% +independence there is one additional + + + align:start position:0% +independence there is one additional +property that turns out to be true the + + align:start position:0% +property that turns out to be true the + + + align:start position:0% +property that turns out to be true the +expected value of the product of two + + align:start position:0% +expected value of the product of two + + + align:start position:0% +expected value of the product of two +independent random variables is the + + align:start position:0% +independent random variables is the + + + align:start position:0% +independent random variables is the +product of their expected values let us + + align:start position:0% +product of their expected values let us + + + align:start position:0% +product of their expected values let us +verify this relation we are dealing here + + align:start position:0% +verify this relation we are dealing here + + + align:start position:0% +verify this relation we are dealing here +with the expected value of a function of + + align:start position:0% +with the expected value of a function of + + + align:start position:0% +with the expected value of a function of +random variables where the function is + + align:start position:0% +random variables where the function is + + + align:start position:0% +random variables where the function is +defined to be the product function so to + + align:start position:0% +defined to be the product function so to + + + align:start position:0% +defined to be the product function so to +calculate this expected value you can + + align:start position:0% +calculate this expected value you can + + + align:start position:0% +calculate this expected value you can +use the expected value rule and we are + + align:start position:0% +use the expected value rule and we are + + + align:start position:0% +use the expected value rule and we are +going to get the sum over all X the sum + + align:start position:0% +going to get the sum over all X the sum + + + align:start position:0% +going to get the sum over all X the sum +over all Y of G of X Y but in this case + + align:start position:0% +over all Y of G of X Y but in this case + + + align:start position:0% +over all Y of G of X Y but in this case +G of XY is x times y and then we weigh + + align:start position:0% +G of XY is x times y and then we weigh + + + align:start position:0% +G of XY is x times y and then we weigh +all those values according to the + + align:start position:0% +all those values according to the + + + align:start position:0% +all those values according to the +probabilities as given by the joint PMF + + align:start position:0% +probabilities as given by the joint PMF + + + align:start position:0% +probabilities as given by the joint PMF +now using independence this sum can be + + align:start position:0% +now using independence this sum can be + + + align:start position:0% +now using independence this sum can be +changed into the following form the + + align:start position:0% +changed into the following form the + + + align:start position:0% +changed into the following form the +joint PMF is the product of the marginal + + align:start position:0% +joint PMF is the product of the marginal + + + align:start position:0% +joint PMF is the product of the marginal +pmfs and now when we look at the inner + + align:start position:0% +pmfs and now when we look at the inner + + + align:start position:0% +pmfs and now when we look at the inner +sum over all values of Y we can take + + align:start position:0% +sum over all values of Y we can take + + + align:start position:0% +sum over all values of Y we can take +outside the summation those terms + + align:start position:0% +outside the summation those terms + + + align:start position:0% +outside the summation those terms +do not depend on why and so this term + + align:start position:0% +do not depend on why and so this term + + + align:start position:0% +do not depend on why and so this term +and that term and this is going to yield + + align:start position:0% +and that term and this is going to yield + + + align:start position:0% +and that term and this is going to yield +a summation over X of x times the + + align:start position:0% +a summation over X of x times the + + + align:start position:0% +a summation over X of x times the +marginal PMF of X and then the summation + + align:start position:0% +marginal PMF of X and then the summation + + + align:start position:0% +marginal PMF of X and then the summation +over all y of Y times the marginal PMF + + align:start position:0% +over all y of Y times the marginal PMF + + + align:start position:0% +over all y of Y times the marginal PMF +of Y but now we recognize that here we + + align:start position:0% +of Y but now we recognize that here we + + + align:start position:0% +of Y but now we recognize that here we +have just the expected value of y and + + align:start position:0% +have just the expected value of y and + + + align:start position:0% +have just the expected value of y and +then on we will be left with another + + align:start position:0% +then on we will be left with another + + + align:start position:0% +then on we will be left with another +expression which is the expected value + + align:start position:0% +expression which is the expected value + + + align:start position:0% +expression which is the expected value +of x and this completes the argument now + + align:start position:0% +of x and this completes the argument now + + + align:start position:0% +of x and this completes the argument now +consider a function of x and another + + align:start position:0% +consider a function of x and another + + + align:start position:0% +consider a function of x and another +function of y x and y are independent + + align:start position:0% +function of y x and y are independent + + + align:start position:0% +function of y x and y are independent +intuitively the value of x does not give + + align:start position:0% +intuitively the value of x does not give + + + align:start position:0% +intuitively the value of x does not give +you any new information about Y so the + + align:start position:0% +you any new information about Y so the + + + align:start position:0% +you any new information about Y so the +value of G of X does not give you any + + align:start position:0% +value of G of X does not give you any + + + align:start position:0% +value of G of X does not give you any +new information about H of Y so on the + + align:start position:0% +new information about H of Y so on the + + + align:start position:0% +new information about H of Y so on the +basis of this intuitive argument the + + align:start position:0% +basis of this intuitive argument the + + + align:start position:0% +basis of this intuitive argument the +functions G of X and H of Y are also + + align:start position:0% +functions G of X and H of Y are also + + + align:start position:0% +functions G of X and H of Y are also +independent of each other therefore we + + align:start position:0% +independent of each other therefore we + + + align:start position:0% +independent of each other therefore we +can apply the fact that we have already + + align:start position:0% +can apply the fact that we have already + + + align:start position:0% +can apply the fact that we have already +proved but with G of X in the place of X + + align:start position:0% +proved but with G of X in the place of X + + + align:start position:0% +proved but with G of X in the place of X +and H of Y in the place of Y and this + + align:start position:0% +and H of Y in the place of Y and this + + + align:start position:0% +and H of Y in the place of Y and this +gives us this more general fact that the + + align:start position:0% +gives us this more general fact that the + + + align:start position:0% +gives us this more general fact that the +expected value of the product of two + + align:start position:0% +expected value of the product of two + + + align:start position:0% +expected value of the product of two +functions of independent random + + align:start position:0% +functions of independent random + + + align:start position:0% +functions of independent random +variables is equal to the product of the + + align:start position:0% +variables is equal to the product of the + + + align:start position:0% +variables is equal to the product of the +expectations of these functions we could + + align:start position:0% +expectations of these functions we could + + + align:start position:0% +expectations of these functions we could +also prove this property directly + + align:start position:0% +also prove this property directly + + + align:start position:0% +also prove this property directly +without relying on the intuitive + + align:start position:0% +without relying on the intuitive + + + align:start position:0% +without relying on the intuitive +argument we could just follow the same + + align:start position:0% +argument we could just follow the same + + + align:start position:0% +argument we could just follow the same +steps as in this derivation wherever + + align:start position:0% +steps as in this derivation wherever + + + align:start position:0% +steps as in this derivation wherever +there's an X we would write G of X and + + align:start position:0% +there's an X we would write G of X and + + + align:start position:0% +there's an X we would write G of X and +wherever there is a Y we would write H + + align:start position:0% +wherever there is a Y we would write H + + + align:start position:0% +wherever there is a Y we would write H +of Y and the same algebra would go + + align:start position:0% +of Y and the same algebra would go + + + align:start position:0% +of Y and the same algebra would go +through and we would end up with the + + align:start position:0% +through and we would end up with the + + + align:start position:0% +through and we would end up with the +expected value of G of x times the + + align:start position:0% +expected value of G of x times the + + + align:start position:0% +expected value of G of x times the +expected value of H of Y \ No newline at end of file diff --git a/RcAkiv8Bkpo.txt b/RcAkiv8Bkpo.txt new file mode 100644 index 0000000000000000000000000000000000000000..4dc5ecd5023731cf24dfd2f72192ebc4008d2f73 --- /dev/null +++ b/RcAkiv8Bkpo.txt @@ -0,0 +1,99 @@ +align:start position:0% + +foreign + + align:start position:0% + + + + align:start position:0% + +how does diversity strengthen science + + align:start position:0% +how does diversity strengthen science + + + align:start position:0% +how does diversity strengthen science +can freezing your credit card help you + + align:start position:0% +can freezing your credit card help you + + + align:start position:0% +can freezing your credit card help you +spend less what is a seed librarian and + + align:start position:0% +spend less what is a seed librarian and + + + align:start position:0% +spend less what is a seed librarian and +what can they teach us is nuclear + + align:start position:0% +what can they teach us is nuclear + + + align:start position:0% +what can they teach us is nuclear +warfare still the greatest threat to + + align:start position:0% +warfare still the greatest threat to + + + align:start position:0% +warfare still the greatest threat to +life on Earth + + align:start position:0% + + + + align:start position:0% + +welcome to chalk radio season four tune + + align:start position:0% +welcome to chalk radio season four tune + + + align:start position:0% +welcome to chalk radio season four tune +in soon to hear candid personal and + + align:start position:0% +in soon to hear candid personal and + + + align:start position:0% +in soon to hear candid personal and +eye-opening conversations with some of + + align:start position:0% +eye-opening conversations with some of + + + align:start position:0% +eye-opening conversations with some of +mit's most passionate Educators + + align:start position:0% +mit's most passionate Educators + + + align:start position:0% +mit's most passionate Educators +subscribe to our channel to never miss + + align:start position:0% +subscribe to our channel to never miss + + + align:start position:0% +subscribe to our channel to never miss +an episode \ No newline at end of file diff --git a/RwDQWPhNZ8U.txt b/RwDQWPhNZ8U.txt new file mode 100644 index 0000000000000000000000000000000000000000..14428fb351aefaa37d52003a279172fd50199904 --- /dev/null +++ b/RwDQWPhNZ8U.txt @@ -0,0 +1,6062 @@ +The following content is +provided under a Creative + +Commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high-quality educational +resources for free. + +To make a donation or view +additional materials from + +hundreds of MIT courses, visit +MIT OpenCourseWare at + +ocw.mit.edu. + +PROFESSOR: When did +you arrive at MIT? + +ROSALIND WILLIAMS: I was +a post-doc in 1980. + +PROFESSOR: Yeah, I just +remember that. + +PROFESSOR: So Ros is also a +historian of technology. + +But she practices the craft +a little different + +than David and I do. + +She focuses on the cultural +side of things and is an + +expert in literature and what +writers have said about + +technological change +and has written a + +lot about those subjects. + +But also, she served +as the dean of + +undergraduate education. + +ROSALIND WILLIAMS: And +student affairs. + +I did both jobs. + +PROFESSOR: I didn't know +if I had the title. + +There was one time when you +didn't have two deans. + +You didn't a dean for +residential life. + +You had them combined +in one office. + +And she got stuck with that +job, which is as you might + +imagine, is a lot of work. + +And so Ross did that +for at least six-- + +ROSALIND WILLIAMS: Five years. + +PROFESSOR: Five years. + +So that's been a big +item on her agenda. + +And now, she's back +in the department. + +And today, she's going to talk +about chemical engineering + +basically, in the early +20th century. + +And this is extremely +interesting. + +She gave a lecture about +it last year. + +Because her grandfather +was Warren K. Lewis. + +If any of are familiar with the +"Lewis Report" of the late + +1940s, that's the report that in +effect that established the + +School of Humanities and +Social Sciences. + +But here's a chemical engineer +who is a very much involved + +and looking at all aspects of +life at MIT and coming up with + +this report. + +And as they say, the +rest is history. + +So Ros has a long lineage here, +that your grandfather + +goes back to the early +1900s, I would say. + +Didn't he get here-- + +ROSALIND WILLIAMS: He +was class of '05. + +PROFESSOR: Yeah. + +So she's going to talk +about this area. + +And she's brought some very +interesting materials I'm + +anxious to look at. + +ROSALIND WILLIAMS: So I wanted +to do something new this time. + +And that's why in the +last hour, I went + +though my Lewis box. + +Archives are just +boxes of stuff. + +This is from my attic. + +And the library's is just +not that different. + +And I pulled out some little +treasures, at least I think + +they're treasures, that will +give you a flavor of what + +archives are like and when +you're doing history, what you + +learn from archives that you +don't learn online, can't + +learn online. + +I may overstate that. + +I may take that back. + +But I'll stand by it for +a talking point. + +So I'm going to start with +giving you an overview of + +intertwined biography of Warren +K. Lewis and of the + +world here in the Boston area, +Cambridge, and MIT + +specifically, as they +intertwined. + +And in discussing afterwards, we +can talk about him, we can + +talk about chemical +engineering. + +We can also talk about +deanly things. + +If you're interested in student +life history, I've + +done a little boning up on that +for a documentary that + +was being shot last week +about the evolution of + +student life at MIT. + +So I sort of refreshed my memory +about some points on + +that topic. + +So we talk about anything +you want to talk about. + +But first of all, let me give +you some what my grandfather + +used to say, you want to put +the fodder down where the + +calves can get at it. + +So I'm going to put +out some fodder. + +Fodder is food, so cow food. + +They say you've got +to put it down. + +So I'm putting it down. + +And we'll chew on this +together and then see + +where it takes us. + +So this is this kind of +biographical history of + +chemical engineering at MIT. + +I remember my grandfather +sitting in the living room + +holding forth, as he was +wont to do, in Newton, + +Massachusetts. + +This is where he lived with my +grandmother and mother and + +three other siblings. + +He was a boarder in +the household + +and married the daughter. + +And this is a little part +history right there. + +Most MIT students, there +weren't residences. + +So you boarded with families or +you were in a fraternity. + +So boarding was very common. + +Let me just me just mention +something about his family. + +You see his dates. + +His father was born in 1845, +in Laurel, Delaware. + +And his father, my grandfather's +grandfather, had + +been born in the kind of, +well, mid to late 1700s. + +He had three wives. + +My grandfather's father +was the last child + +of the third wife. + +So there's a huge gap in the +half-brothers, between Henry + +Clay Lewis, Henry Clay Lewis, +that's the name of my + +grandfather's father, and the +first wife's, first child. + +Many of these children died. + +But this is just a part of +history, the fact that if I go + +from my grandfather, to his +father, to his father, I'm + +back to the Revolutionary War. + +Because his grandfather had a +brother who died in a prison + +ship, moored in the Hudson +River during the + +Revolutionary War. + +So it's just amazing to me that +you just take a few steps + +and you're back in +time, like that. + +This is Delaware. + +Delaware was a slave state. + +It was a slave-owning family. + +Also an abolitionist family, +which is a strange + +combination. + +But it's one of those, it's a +nice idea, but not until I die + +will I free my slaves, family. + +And that's what happened. + +But his father was one of the +two votes for Abraham Lincoln + +in his county in Delaware +in 1860. + +And his father-- + +God, these dates don't +seem right. + +Because if his father +is born in 18-- + +OK. + +It was his grandfather, his last +vote was for Abe Lincoln, + +that's it, in Laurel, +Delaware. + +If you look at the history of +slavery in Laurel, what's + +fascinating is that next door +was Maryland, where slaves + +could be traded, but +not in Delaware, + +after a certain date. + +You may know that. + +But in Delaware, you could +hold slaves, but you + +couldn't sell them. + +So there's a huge kidnapping +ring, where people from + +Maryland would go just over the +border to Laurel, kidnap + +either free blacks or slaves, +take them back to Maryland, + +where they could be sold +for a huge profit. + +Because at that time, they could +still be sold to other + +parts of the United States. + +So Delaware, Laurel was the +site of the Patty Cannon + +kidnapping ring, which is +a fascinating story. + +But it's not the story +I'm here to tell. + +But it does give context. + +This is a farm boy. + +Kenny was raised on the farm +in Laurel, Delaware. + +Expecting to say on the farm, +and his life, he got hijacked + +by the 20th century. + +These are just some more +pictures holding forth. + +That's a very familiar +pose, very familiar. + +PROFESSOR: You know it well. + +ROSALIND WILLIAMS: Yeah. + +I mean as a granddaughter, +you knew this guy. + +Students were terrified of him +because he'd get you up here. + +And you'd start doing something +on the board. + +And you wouldn't know +what you were doing + +and he would pounce. + +But as a granddaughter, it was +just a very affectionate + +relationship. + +I was aware how much he +terrified other people. + +But that was not my relationship +with him. + +That's the farmhouse, still +in a Laurel, Delaware. + +It used to be a bed and +breakfast not that long ago. + +I don't think it's in +business anymore. + +That's my brother. + +That's more Warren K. Lewis, +Jr., my uncle, and my + +grandfather. + +This is in 1952. + +He has just sold the farm. + +Heart breaking, because it had +been in the family back to the + +late 1700s. + +But a part of the farm was cut +through by a road, the dual, + +they call it there, +a dual highway. + +Route 14 cut through a corner of +the farm and he realized it + +was never going to be a +working farm again. + +And the irony is of course that +part of the reason for + +putting in that highway is that +DuPont had established + +big factories in northern +Delaware. + +And there's more commuter +traffic from south to north. + +So chemical engineering, +in a sense, + +destroyed the family farm. + +And I say there's +a sort of irony. + +There's quite a bit +of irony there. + +Not to mention the fact that the +whole automobile age was + +in part made possible through +new methods of refining + +petroleum, using catalytic +cracking, that my grandfather + +directly worked on. + +This is not the best-- but this +is the Eastern Shore, + +this peninsula. + +The Chesapeake Bay is here. + +So Baltimore is up +around here. + +Washington is kind of off +the map, over here. + +And Philadelphia is +to the north. + +But this is the Eastern Shore. + +And it's Virginia down here. + +You can't see the map-- + +the split division. + +So last time I went, I go to +the airport in Baltimore, I + +drive over the Chesapeake Bay +Bridge, I go down to roads, + +about right in the middle. + +And that takes me two hours. + +So you go from one end to the +other in a couple hours. + +With the dual, you +go fast, yeah. + +So there is a Maryland +over here. + +Oh, you can see the +dotted line, OK. + +So this is Maryland over here. + +This is where like Dick Cheney +lives now, in Easton. + +It's very high, upper crust. + +And this is Delaware, +which is much more + +farming, much more rural. + +And then Virginia down here. + +It's pretty rustic. + +The Chincoteague ponies, +Chincoteague is one of these + +islands off of here. + +So this is a garden spot in the +18th and 19th centuries. + +It is the truck garden area +for the Philadelphia and + +Baltimore markets, raising +mainly corn, fruits, + +vegetables, peaches, tomatoes, +live stock. + +It's mixed farming. + +And I'll tell you some more +about that as we go on. + +But the reason I have this map-- +this is from Bob Post-- + +the railroad comes to +Laurel in 1859. + +And that opens up the whole +area to commercial + +farming much more. + +I mean it had always been +such, but even more. + +Now, my grandfather's +grandfather was a sea captain. + +Farming was his-- + +that's where the wife +and kids stayed. + +But he made his money in the +trade, starting from the + +Chesapeake, doing a lot of +trade of the Caribbean. + +So that's where his +money came from. + +I mean he was a large, +established farmer and the + +state legislator. + +So he was a politician. + +But he was a well-off person +for Delaware, but still + +basically a sea captain +and a farmer. + +So the railroad comes. + +And this is sort of getting +ahead of the story. + +But my grandfather born in +1882, he goes through the + +three-year high school +in Laurel, Delaware. + +And learns everything you learn +there, because there's + +one teacher for all grades, +in one classroom. + +And his parents want him to +get a better education. + +He's an only child. + +He's obviously going to +inherit the farm. + +So they want him to go to a +better high school than the + +Laurel one. + +So his cousin, she's actually +a cousin I guess. + +He had an older female cousin +named Mary Witherby, who had + +left Laurel to teach school, +like her father, and she was + +teaching school at the Lasell +Female seminary, which still + +exists around here. + +Do any of you-- + +you know what I'm +talking about. + +PROFESSOR: Oh, sure. + +ROSALIND WILLIAMS: It's +now Lasell College. + +It used to be junior college, +now college. + +Yeah, and it's in West Newton, +just a stone's + +throw from your place. + +So my grandfather was sent up +by his parents to live in + +Newton, go to high school. + +Newton High was famous even +then as a good school. + +He would board with +the family. + +But he had his cousin in town. + +And she would look after him +and make sure he didn't get + +into too much trouble. + +This house is a block away +from where I live now. + +I go there all the time. + +So that's still there, one of +the older houses in the + +neighborhood. + +So this is where he boarded. + +Now, I happen to have his diary +from his first full + +winter at Hunnewell +Avenue in Newton. + +And it starts January +10, 1898 and it + +goes through the spring. + +So I'm a little mixed up about +the timing, because I believe + +this is his second year I +believe at Newton High. + +His first year he came up, he +got an A in arithmetic, a D in + +drawing, and F's in +everything else. + +So it was not a good high school +he was coming from. + +And he really had to catch up. + +By this time, I think it's the +second year, he's got his feet + +under him and he's +doing better. + +So he's boarding in +the winter of '98. + +And I just want to read a few +little details that will give + +you a sense of what life was +like, daily life was like for + +him at that time. + +This is the Second Industrial +Revolution, is what we call it + +from up here. + +But down here, this +is what it's like. + +After school, this is high +school, he says, this is + +January 12, I went up to Lasell +and read Cicero with + +cousin Mary. + +Who's Cicero? + +What does this tell you? + +You read Cicero in Latin. + +You start with doing Cicero. + +You wind up with Cicero +and Virgil. + +So he's reading his Latin +with his cousin. + +And then she gave me a supper +of canned chicken, cocoa, + +bread, butter, crackers, +and peanut butter. + +I had a fine time. + +OK, canned chicken? + +I mean I don't have +to rub this in. + +You can figure this out. + +This is not off the farm. + +Canned chicken, cocoa, you know +we're dealing with the + +Caribbean at least, if that's +not the East Indies. + +Bread, butter, all +right, crackers-- + +packaged food-- and +peanut butter. + +OK. + +So he mentions that-- at home, +he got a letter from home. + +And the letter from home says +four factories were going up + +in Laurel and vicinity +for canning. + +He, my father-- + +this is my grandfather's father, +he is going to put out + +10 acres of tomatoes. + +He has only four cows now. + +So there's a lot of agricultural +history there. + +There's a new canning factory, +more tomatoes, fewer cows. + +So just to jump ahead, my +grandfather would say that he + +paid for his MIT tuition when he +got to MIT, with tomatoes, + +sold to a cannery at $4 a ton. + +PROFESSOR: Jesus, $4 a ton. + +ROSALIND WILLIAMS: $4 a ton. + +Now, he had the bright +idea, during his + +college years, of recycling. + +That is, using the tomato skins, +which are removed in + +the canning process, or they +tried to remove them, using + +those skins to feed to +the cows as fodder. + +And they tried it. + +The cows ate them. + +But then they gave pink milk. + +So it didn't work. + +OK, just a few more of +these from his diary. + +We're still back in +January 1898. + +Today, as I was walking home +from school, cousin Mary in + +the electrics-- + +so what are the electrics? + +PROFESSOR: Trolleys. + +ROSALIND WILLIAMS: Trolleys. + +OK, the street car suburbs-- + +this is a little digression. + +But this is showing how the +electric trolley system was + +being extended at the time. + +This is the Sam Best Warner's +classic study. + +And the trolley, which I +remember from my childhood, + +near Hunewell Avenue, where he +lived, is just a block away. + +You can just walk. + +In fact, now it's +a bus system. + +But it's the same route. + +And you can get on where +we live and go to + +Fenway Park in one stop. + +PROFESSOR: No wonder you live +in that neighborhood. + +ROSALIND WILLIAMS: Of +course, you got it. + +Then we went into Boston. + +Cousin Mary in the electrics, +saw me, got out and walked + +home with me. + +Then we went into Boston. + +Now, this would have been on the +train track, which is the + +other side of the hill +that he's looking on. + +Went into Boston. + +And she bought two tin basins, +a pie pan, a strainer, and a + +dozen knives and forks. + +She carried it in a mug strainer +belonging to the + +coffee pot, to fit the strainer +she brought to it. + +So she's buying a piece +for her coffee pot. + +She's buying all this +stuff, taking the + +electrics into Boston. + +So this tells you a lot +about technological + +systems of the day. + +But I think my favorite +entry from this + +diary, this is in February. + +He says, I went downtown. + +This would be Newton Corner. + +I went downtown in the evening +and rode, R-O-D-E, underlined. + +I asked a man passing, for +a ride, and he consented. + +It was the first time, +underlined, I've ridden, + +underlined, on or behind a horse +since last September, + +and I a farmer's boy. + +So there's cars, there's +trolleys, there's trains. + +But he wants to ride the horse, +because that's what + +farmers; boys did. + +There's a lot. + +I could go on and on +about what you find + +out from this diary. + +There's a lot of reading, +Cicero, Shakespeare. + +There's a lot of magazines. + +He's reading magazines a lot. + +He's going to church. + +There are church plays. + +There are glee club performances +at Lasell. + +He goes into Boston for lectures +at the temple, + +Fremont Temple. + +He goes to the Museum of Fine +Arts, still with us, discusses + +modern illustrators who +are exhibited there. + +Then cousin Mary gives +him some pictures. + +But I mean it is an information + +age, in its own way. + +It's just a different +kind of media. + +But he's very connected. + +So, for example, on January +20, he says he goes into + +Boston to hear a lecture +on imperialism + +by Dr. Lyman Abbott. + +Now why in 1898, is he going to +a lecture on imperialism? + +What's going on? + +What's the news? + +Anybody know? + +AUDIENCE: Spanish-American +War. + +ROSALIND WILLIAMS: OK? + +Which-- + +PROFESSOR: He said it. + +ROSALIND WILLIAMS: +Spanish-American War, go to + +the head of the class, yeah. + +And it's interesting. + +He says the lecture was a fine +one in favor of staying to + +help them, the Filipinos in +this case, learn to govern + +themselves. + +And then he goes to another +lecture the next week, same + +topic, another speaker, who +also make good points. + +But cousin Mary said +some bad ones. + +He attacked, the second speaker, +Dr. Abbott, the first + +speaker, saying he had made some +misstatements concerning + +the arguments on Californian +annexation and made McKinley + +out as having imperial power. + +So there's debate going on. + +And then on February 7, we +received our first news + +yesterday of the Battle +of Manila. + +Reports of dead and wounded, +the gunboats + +did a fearful execution. + +Then there's Washington's +birthday soon after, the + +church bells ring all day. + +And my grandfather writes, these +are signs to me that it + +is the anniversary of the +birth of the greatest + +American, underlined, +ever borne. + +OK, anyway. + +PROFESSOR: It wasn't +Abe Lincoln. + +ROSALIND WILLIAMS: Um, true. + +PROFESSOR: It was GW. + +ROSALIND WILLIAMS: It was GW. + +How about that. + +AUDIENCE: [INAUDIBLE]. + +ROSALIND WILLIAMS: Yeah. + +PROFESSOR: Well, her-- + +yeah, but her-- + +it would be your great +grandfather's-- + +whose name is Henry Clay. + +Now, Henry Clay-- + +ROSALIND WILLIAMS: +That's another-- + +yeah. + +PROFESSOR: But Henry Clay +was Abraham Lincoln's + +great idol in a way. + +ROSALIND WILLIAMS: I mean the +story of this family and + +slavery is just fascinating. + +PROFESSOR: Yeah, it's very +interesting, very interesting. + +ROSALIND WILLIAMS: Well, I just +showed you this paper of + +my grandmother's, my +grandfather's wife, on the + +Negro problem in 1921. + +Because my grandfather, he +wanted to go back to the farm + +and improve race relations by +starting that farm up again in + +the right way. + +And that never happened. + +But that was the idea. + +OK, instead what happens? + +In the spring, he asked two +teachers at Newton High what + +they thought would be best for +him to do about college? + +They will think it +over, he writes. + +But the former advised either +Amherst Agricultural-- + +what's that? + +PROFESSOR: New Mass. + +ROSALIND WILLIAMS: Yeah, it's +the University of Amherst now, + +the Ag School-- other Amherst +agriculture, or as even + +better, tech. + +One of them mentioned +Cornell, but tech. + +Here we are. + +So he thinks about it. + +By the way, this is just a +picture of downtown Boston, + +when they take the +train in there. + +I was there Friday, meeting +my son and his girlfriend. + +It's not-- + +they're not people +like I know. + +And I was saying to my son, oh +gee, my grandparent's would be + +so distressed to see this. + +And he said-- he has a place +in Fort Point, he said. + +But that's up and coming. + +That needs to be [INAUDIBLE]. + +And now, it's happening. + +But let me just mention, I mean +these are quick reminders + +that the occupation of +engineering was growing very + +quickly at the time. + +And that the people who went +into engineering-- + +my grandfather is very typical, +in being off the farm + +and not particularly +well educated. + +This is the way for young men, +almost always young men, to + +have a professional or +quasi-professional career, + +without having to consider +postgraduate study, like law + +or divinity or medicine +required. + +So here's Boston Tech. + +You must have seen this picture + +somewhat, in this class. + +Here's Trinity Church +in Copley Square. + +This is Boston Tech? + +PROFESSOR: It's Boston Tech. + +ROSALIND WILLIAMS: Yeah. + +And I've seen other photos where +I can't really place it. + +So I would love to see somebody +do a sort of up to + +date GPS showing exactly-- + +AUDIENCE: So that's +still there. + +ROSALIND WILLIAMS: That's +there, yeah. + +AUDIENCE: And then across the +street from that building is + +Brooks Brothers, on Berkeley +Street, across from + +[INAUDIBLE]. + +ROSALIND WILLIAMS: This is all +one big building there. + +AUDIENCE: Yeah, that's +the [INAUDIBLE]. + +PROFESSOR: There's actually a +plaque on the front of that + +office building + +ROSALIND WILLIAMS: But there was +another building, not the + +Rogers Building, but +another building, + +like off to the side. + +PROFESSOR: Yeah. + +It would be in that direction. + +AUDIENCE: There's a +bunch of stuff. + +Mark Jarzombek showed us a map, +and sort of to the right + +of where the photograph is. + +There's train tracks +and stuff there. + +ROSALIND WILLIAMS: Now, the +steep steps, was that on this + +building, on the Rogers +Building, or the second one? + +PROFESSOR: I think +it's right there. + +ROSALIND WILLIAMS: Oh, there. + +PROFESSOR: Right there. + +ROSALIND WILLIAMS: Oh, OK. + +OK. + +Because again, my grandfather +had a story about a kind of a + +riot involving Harvard and MIT +students and a fire and he was + +on the witness stand. + +And it had to do +with the steps. + +Some things don't change. + +AUDIENCE: Mark talked +about the difference + +between those two-- + +ROSALIND WILLIAMS: These +two buildings. + +AUDIENCE: --buildings. + +But they're separated by +a couple of decades. + +But closer is a custom-built +laboratory, where you can see + +the fumes of the vents coming +at the top there. + +ROSALIND WILLIAMS: Oh, that +has happened here. + +That's fascinating. + +So in the subway spot at +Kimball, it says the second + +building MIT build was +a gym, a gymnasium? + +Does anybody-- + +I just read it there the +other day, thinking + +that's the first I knew. + +So Warren K. Lewis enters MIT +in 1901, planning to study + +chemical engineer-- excuse me, +mechanical engineering, still + +the dominant engineering, kind +of the default mode. + +But he had a friend, this friend +that he was boarding + +with in Newton, whose sister he +eventually married, urged + +him to try chemical +engineering. + +It seemed more interesting +and so on and so forth. + +So as you know from your +reading, something like + +industrial chemistry +had begun. + +Actually, it was 1888, I think +was the first offerings in + +industrial chemistry. + +And by 1893, there was a lab. + +This is sort of like the +first start of chemical + +engineering at MIT. + +But then because of deaths and + +departures, it sort of declined. + +But just when my grandfather's +was entering, actually in + +1903, this is when Walker +comes back. + +And Noyes had been there +for a couple years. + +So it's sort of like a +false start early on. + +And then it kind of +restarted around + +the turn of the century. + +And this is something that he +wrote many years later, that I + +think captures the overall +feeling of the time. + +Lewis wrote, the stimulus of +these concepts, and he's + +referring to unit operations +and these related concepts, + +the stimulus of these concepts +made work in chemical + +engineering at the Institute +from 1902 to the outbreak of + +World War I an inspiration for +both staff and student, which + +it is impossible to describe. + +So these are happening years. + +I mean the tension between +Noyes and Walker is a + +productive tension. + +They had each other +to play off of. + +And they certainly did. + +By the way, you know +Walker, that's not + +Walker, Memorial Walker. + +Walker Memorial is named after +Francis Amasa Walker, one of + +the early presidents. + +Have I got it right? + +PROFESSOR: Yup. + +ROSALIND WILLIAMS: And we're +talking about William Walker. + +It's no relation. + +So it's important to +those straight. + +So you have these two very +strong personalities. + +This is Noyes, trained in +Germany, a physical chemist. + +And really brought in serious +chemistry to the program, + +beginning in 1902. + +And then you have William H. +Walker, who had also been + +educated in Germany, Penn State +and Gottingen, both. + +And was teaching analytical +chemistry, the partner of A.D. + +Little, which was originally +Little and Walker. + +So he was entrusted with +Course 10 in 1903. + +And was entrusted with building +it up into a chemical + +engineering curriculum. + +Now this, you can't read. + +But I will read to you, because +this is Walker's + +statement written years later. + +This was after he +had left MIT. + +This is either from the late +'20s or early '30s-- + +well, he died in the '30s. + +So this is his statement of +what he was trying to do. + +It's a fascinating statement. + +So I'm going to read you +what Walker wrote. + +What an industry needed was not +a man who had been taught + +what the industry already knew, +but rather a man who was + +trained to do what the +industry had not + +been able to do. + +The ideal man for the industries +was one who had + +been given a sound knowledge +of chemistry and physics. + +And then as a part of the +curriculum, had been given + +systematic experience in the +application of this knowledge + +to the solution of industrial +problems. + +That he should not be a +specialist, but a solver of + +problems, any kind of problem +that industry might present. + +And then he goes on to say, this +idea met opposition, both + +from established courses +of chemical + +instruction and from industry. + +And the industry thought +it was too theoretical. + +But the scientists thought it +was too industry oriented. + +So Walker is on this very nice +edge between not trying to + +give into one or the other. + +And then he goes on and says-- + +this at the top of the second +paragraph, I love this-- + +to prove the soundness +of this idea, I + +returned to MIT in 1903. + +And after a hot fight with +both the chemical and the + +engineering faculties, I +reconstructed Course X as a + +general educational course +without options. + +And without options, that turns +out to be important. + +So this is a feisty guy. + +And I'm sure that's one reason +he and my grandfather got + +along very well. + +They were both feisty people, +very self assured. + +But my grandfather always would +say, it is Walker who + +invented chemical engineering +in this country. + +He did not claim that +for himself at all. + +But again, my grandfather +studied. + +With Noyes. + +You know, I was just reminding +you, this is particularly in + +Servos's article. + +My grandfather studied with +Noyes, took P-Chem from him, + +and graduating in the +class of '05. + +My grandfather's is this kind of +this grim-- he looks-- kind + +of a grim looking guy. + +And you'll see another +picture. + +I'll pass it around. + +In the spring of his senior +year, he expected to go back + +to the farm, as much as you and +I expect the Sun to come + +up tomorrow. + +However, he got a job in the +lab, I think with Noyes. + +And then that led to somebody, +I don't know whether it was + +Noyes or Walker, one of them +suggested that he apply for a + +traveling fellowship which +was being offered. + +And it was $1,000 stipend, which +is that day and age was + +a lot of money. + +A traveling fellowship, +he could go + +anywhere for a doctorate. + +And so he really was +not interested. + +But one of them basically +appealed to his competitive + +spirit and kind of said well, if +you don't get it, somebody + +else is going to get it. + +And $1,000 sounded very nice. + +He applied, got it and was on +his way to Breslau, in what is + +now Germany, it's kind of on the +Polish-German border, for + +graduate school the next year. + +Later, he found he was in fact +the only applicant that year. + +PROFESSOR: Well, it's +interesting. + +Think about what the Harvard +class of 1905, where they + +might have chosen to have +their picture taken. + +ROSALIND WILLIAMS: Aah. + +AUDIENCE: I'm sure it was +not in the laboratory. + +ROSALIND WILLIAMS: Yeah, yeah. + +I mean this is a good example, +where it tells you so much. + +It does. + +Began with the names +and faces. + +AUDIENCE: Books piled up +in the front of them. + +ROSALIND WILLIAMS: Yeah. + +So-- + +AUDIENCE: What's in the +books on the front? + +ROSALIND WILLIAMS: Yeah. + +Oh yeah, that's great. + +So this is his dissertation in +German, from Breslau, three + +years later. + +He wrote it in Florence, because +he thought Florence + +was the most beautiful city in +the world, and why not write + +your dissertation there? + +I recommend that highly, +if any of you write + +dissertations. + +But this is Germany. + +And just keep that in mind when +we get to World War II. + +PROFESSOR: Yeah, yeah. + +AUDIENCE: World War I. + +PROFESSOR: And he was +sufficiently literate in + +German to be able to write +a dissertation. + +ROSALIND WILLIAMS: Yeah. + +Yeah. + +Well, he never felt his +German was that great. + +And in fact, back to Latin, a +story he tells us taking the + +train to Italy, or maybe +back from Italy. + +But in any case, he was seated +next to somebody-- maybe they + +were like Polish or something. + +But German didn't work. + +The other person didn't +know English. + +So they conversed in Latin. + +PROFESSOR: Is that right? + +ROSALIND WILLIAMS: +You never know. + +PROFESSOR: It's fascinating. + +ROSALIND WILLIAMS: It +may come in handy. + +So then he comes back to-- + +well, he has a year working +at a tannery in + +Manchester, New Hampshire. + +And as a result of that +experience, he always said + +tanneries do not have +to pollute. + +It's not necessary, if +you run them right. + +And they don't have to smell +either, that's the other thing + +you associate was a tannery. + +So he comes back. + +And you can see how chemical +engineering around 1910, + +there's this kind of reversal +of who was majoring in what. + +And this is before the war. + +Because when World War I comes, +even before the US + +enters World War I, the Great +War, in 1917, there's a + +tremendous demand for +military equipment. + +And chemical engineering is +connected with gas warfare, + +which was used right near the +beginning of the war. + +It was in the spring of 1915 +that chlorine was first used + +on the battlefield +as a poison gas. + +Chlorine is not the most +effective, by any means. + +It dissipates pretty quickly. + +But the surprise factor was such +that it really did work + +in the initial use. + +And it had a tremendous +psychological effect in + +scaring people on both sides. + +So Walker, William Walker, was +put in charge of the Edgewood + +Arsenal, once the US +entered the war, to + +manufacture toxic gases. + +And my grandfather was put +in charge of gas defense. + +So he worked on the masks. + +And there's all sorts of-- + +I mean this is very specialized +equipment. + +And to try to design equipment +that made it possible to keep + +fighting and yet would protect +the soldier from poison gas, + +not just the soldier but-- + +do I have some of the-- +the animals too. + +In fact, there's a whole long +story about the horses being + +affected by mustard gas, +which is a vesicant. + +And it's a much nastier gas. + +And it would affect +the animals too. + +So the one story that I need +to tell you about my + +grandfather and gas defense, +this made such an + +impression on me. + +We had this conversation +was I was a teenager. + +Let's see, he said there was not +a single Allied soldier-- + +am I taking too much? + +PROFESSOR: No, no. + +ROSALIND WILLIAMS: It won't +take much longer. + +There's not a single Allied +soldier is World War I who + +died from poison gas when they +had the gas mask and other + +equipment on. + +And I grandpa, you must been so +proud because you designed + +something that was fail-safe. + +It worked every time. + +And he said no, it means +I over designed. + +And what he meant was the +cost of putting on a + +mask is quite high. + +It's makes it hard to breathe. + +And it does encumber you. + +So in designing the gas +mask, you have to make + +it just on the edge. + +Because then, soldiers are more +likely to put it on in + +the first place. + +So by over designing it, it +meant that he was surmising + +that more people had died +but not putting + +on the mask at all. + +Because it was such +a pain to put on. + +And for an engineer to think +that way about human life, it + +just really took me aback. + +And I thought, boy, that's +responsibility. + +After he died in 1975, you clean +out the house of the + +person who has passed on. + +And down in the cellar, big +basement, in the furnace room + +there are these shelves. + +And there were all these gas +masks lined up on the shelves. + +And it turned out at the end of +the war, the Allied troops + +have given him a model of each +of the gas masks that had been + +used by the Allies in the war. + +So he had this collection of +gas masks that were just + +sitting down there. + +And I called the Smithsonian and +I called the MIT Museum, + +and I said I think this +is really interesting. + +But nobody took the gas masks. + +So they have thrown out, +because I tried. + +I tried. + +AUDIENCE: You weren't tempted to +just mount them on wall in + +your living room? + +ROSALIND WILLIAMS: Well, +they're odd. + +Well, I mean we'd been looking +at pictures from Japan, + +testing children. + +And when you get in a haz +suit, it's really scary. + +It's just very curious, +period. + +So no, I was not inclined +to keep them around. + +I was just surprised somebody +didn't want them. + +Well, actually now +I can go back to + +gas masks for a minute. + +You've read about the tension +between Noyes and Walker, + +Walker finally leaving. + +My grandfather finally becoming +head of the chemical + +engineering department in 1920, + +known as Walker's protege. + +But also the real appreciation +for the science-based + +engineering. + +And the more I read Servos's +article, the more I would love + +to look at his headship of +Course 10 in that period. + +I think it's a really +interesting story. + +I don't know it. + +But I'm almost sure +it's there. + +OK, he it comes back. + +Heads the department for 10 +years, but that isn't what he + +wants to do. + +He's not an administrative +type. + +He doesn't like it. + +He loves teaching and he's +famous for his teaching. + +And that's where he really +made his mark. + +But he did a lot of consulting +for what was what was then + +Standard Oil in New Jersey, +Esso, Exxon. + +And one thing your articles +didn't mention I think is the + +relationship between the +university and industry + +through consulting +work and how that + +fits into the picture. + +And he was a great believer in +the value of consulting. + +That's how you find out what's +happening in the world and it + +keeps you on your toes. + +And it's also useful +for industry. + +So he, to his death, he got a +check every month from Exxon. + +I mean it wasn't a lot, +but it was a retainer. + +And he died at what, 94. + +So they were very loyal +to him and vice versa. + +So this is a drawing of the +catalytic cracking process. + +Let's see, have you been to +the MIT Museum exhibit? + +You must have been. + +AUDIENCE: I have. + +ROSALIND WILLIAMS: OK. + +And you go through +the whole thing. + +And just when you're going to +leave when to go out of the + +exhibit in that back room, on +the left, is a picture of my + +grandfather and a couple other +gentlemen at a refinery in + +Venezuela where catalytic +cracking has been put into + +production in 1939. + +And there's a barrel +above there, an + +empty barrel I trust. + +But anyway, just to +make the exhibit + +about catalytic cracking. + +But the timing, 1939, means that +once the war broke out in + +1940, the demand for aviation +fuel was huge. + +I mean catalytic cracking began +as a way to get higher + +octane for automobiles. + +And it was the automobile +race that instigated it. + +AUDIENCE: Does everybody know +what catalytic cracking is? + +ROSALIND WILLIAMS: So let me +give my brief, nontechnical-- + +actually this is very +interesting. + +He did the work in the basement +of Building 12. + +And you need some kind +of a catalytic agent + +to promote the cracking. + +It's usually a powder and its +mixed in with the petroleum to + +get more higher octane fractions +or lighter weight + +fractions out of a certain +amount of petroleum. + +So if you have the same amount +of petroleum and the cracking + +works efficiently, you get more +usable high octane fuel + +than you do without it. + +So you have this-- + +AUDIENCE: You take crude oil, +basically, and separating out + +all the parts. + +ROSALIND WILLIAMS: It's part of +the distillation process. + +And a higher octane means you +can run engines faster and get + +more power out of them, without +knocking and so forth. + +You know when you need higher +octane, if you fill up your + +car and your car starts +knocking. + +That's a sign that things +are not going well. + +It's true in cars. + +It's true in airplanes. + +So they were trying to blow +the catalyst through the + +petroleum stream. + +But as a pattern, it +kept settling out. + +It didn't stay mixed +in with the stream. + +So after months and months of +work, on trying to get it to + +hold into the stream, my +grandfather, who was famously + +profane, said damn it, +let it settle out. + +And in other words, if you let +it settle out, then you get a + +fluid bed at kind of the +bottom of the reactor. + +And it mixes the fumes, the +petroleum fumes with, or + +gases, with the catalyst, better +than if you try to blow + +it along with the stream. + +So it's fluid-bed catalytic +cracking that he and his + +students are known for and +brought a huge fortune to + +Exxon, which is one of +the early adopters. + +What he never imagined +was that-- + +again, it comes on +line in 1939. + +Within a year, the tankers are +going to Venezuela to fill up + +with a high octane aviation +fuel, going to the docks of + +Liverpool, and pumping +the fuel into + +the tanks of Spitfires. + +They don't even put it +in the holding tank. + +They put it right in the +tanks of the airplanes. + +And the Spitfires go +up to do battle in + +the Battle of Britain. + +So it's a dramatic example of +what you do and then how + +things happen to change the +implications of what you do, + +that are entirely out +of your control. + +That of course is also +the story of + +the Manhattan Project. + +When the Manhattan Project +got under way-- + +do I have any slides +about this? + +Oh, this goes back, OK-- + +basically my grandfather is +asked to head up the series of + +committees making +recommendations about the + +extraction and refinement +of fissionable material. + +In other words, the chemical +engineering problems of the + +atomic weapons, they require +high grade ore, high grade + +uranium or plutonium. + +And how do you get it? + +That's an engineering problem. + +That's a chemical engineering +problem. + +So if you go to the MIT archives +and ask for Warren K. + +Lewis material, a lot of it is +still classified from World + +War II, but there is a notebook +that he kept when he + +was going around to, trying +to figure out-- + +I think this is 1941. + +When was the chain reaction +started? '42, right, in Stagg + +Field, Chicago? + +AUDIENCE: Chicago? + +ROSALIND WILLIAMS: Chicago. + +Was that earlier? + +AUDIENCE: Earlier. + +ROSALIND WILLIAMS: +It was earlier. + +AUDIENCE: Before the +war I think. + +ROSALIND WILLIAMS: In the +middle of this notebook, + +appears that event. + +And he's going around to +DuPont, to Oak Ridge. + +He's going out to Berkeley, +Lawrence Lab, talking to all + +these people, trying to figure +out how to do the refining to + +get the material that they would +need for these weapons. + +And he served on a series +of committees. + +Was gone all during the war, +kind of overseeing the + +construction and the development +of these vast + +facilities, especially at Oak +Ridge, also out in Hanford. + +AUDIENCE: If you look at the +Manhattan Project, which my + +favorite statistics would be +the size of the US auto + +industry at the time, a huge +project, less that 10% of it + +is concentrated at Los Alamos +or [INAUDIBLE]. + +Brilliant physicists are-- + +and most of it were chemical +engineering plants in + +Tennessee and in Washington +state, huge plants making the + +actual material. + +ROSALIND WILLIAMS: So he told +his wife, my grandmother, just + +don't ask where I am. + +But if you need me in an +emergency, you call General + +Groves in Washington, and gave +her the phone number. + +And again, I presume the +students have already heard + +this, but my mother was +married in 1940 and + +I was born in 1944. + +So this was kind of +like the next + +generation was coming along. + +And my mother tells me that +when she heard the Lowell + +Thomas announcement of the +bomb being dropped on + +Hiroshima, on the radio, she +said now I know where pop's + +been, all the war. + +And I'm a baby. + +And we're back to Japan +these days. + +OK, I have to think he was +deeply troubled by his role in + +the Manhattan Project because +he didn't talk about it. + +He talked a lot about World +War I and gas masks. + +But World War II, he just-- + +I mean I wish I had pressed +him more, but I didn't. + +My mother said that +after the war-- + +for example, at those days if +you got a watch, a wrist + +watch, and you wanted it to glow +in the dark, they put a + +little radium on the dial just +to make it glow in the dark. + +And he would scrape it off. + +He didn't want any of +that stuff near him. + +Anyway, so I'm surmising. + +But he chaired the Lewis +committee, and you'll hear a + +lot more about that, kept +teaching at MIT. + +My husband had him as a kind +of senior thesis adviser in + +the early 1960s. + +And there's a lot of letters +that he wrote about the role + +of the engineer and +civilization, the profession + +of engineering. + +And this quote from +the Lewis Report I + +think really captures-- + +I mean we don't know who +actually wrote it. + +Maybe it Morrison or somebody. + +But he really believes that. + +He said, if I could come back, +it would be as a social + +scientist, because that's where +the big problems are, + +the really intractable ones. + +I can see after World War II +why you would say that. + +So that's the-- + +yeah, the Spring Garden +farm again. + +OK, so back to the farm. + +So what I did in about 15 +minutes before class was just + +go through my box of stuff. + +And I'm just going to +pass this around. + +Obviously, just collect +it back there, when it + +gets back to you. + +The point is what you learn from +archives that you don't + +learn from reading articles +or so forth. + +Monthly Report, Laurel City +Schools, Laurel, Delaware, + +Report of Warren Lewis, 1895. + +This tells you sort of, not only +what his grades are, but + +what they're teaching. + +PROFESSOR: Is that the +original document? + +ROSALIND WILLIAMS: That's +the document. + +Why do I have this stuff? + +I have no idea. + +I gave a lot of it +to the archives. + +And they have copies of this. + +And I kept a few original +documents. + +There's a lot more. + +I mean I am from a very +literate family. + +I don't know how +else to put it. + +Now Ross Basset told you about +going through MIT yearbooks + +and looking at where +people are from? + +PROFESSOR: A little bit. + +ROSALIND WILLIAMS: This is my +grandfather on the left. + +So this is what Ross was looking +at, hometown and list. + +My grandfather's list +is very brief. + +But again, I just thought +you'd like to see. + +And Breslau, here are +photographs of Breslau, where + +he studied, got his Ph.D. +I mean it got bombed to + +smithereens in the war. + +None of this is here anymore. + +But this is old Germany. + +PROFESSOR: Did you ever go back +to try to visit there? + +ROSALIND WILLIAMS: +Not Breslau, no. + +I think it blew all +to smithereens. + +PROFESSOR: Probably +nothing to see. + +ROSALIND WILLIAMS: And I had a +couple of bigger photos, that + +are really beauties, that I +have framed it at home. + +And here's his dissertation. + +I'm not sure, my German +not being workable. + +But it's signed Rosalind D. +Kenway, from Warren, July '05, + +that's my grandmother. + +The Tech, special chemistry +and chemical engineering + +issue, 1910. + +So remember that chart showing +chemistry is going down and + +chemical-- so this is published +at that time. + +I have no idea why I have +this, but I do. + +And it's so interesting. + +Few industries not founded +on chemistry, it says. + +Now, this is a Xerox. + +This is his father basically +selling off the stock of the + +farm, public sale of +valuable cows. + +And this is what his father +writes in 1917, back in + +Laurel, Delaware. + +I have sailed life's storm-swept +sea for 74 years + +and I am now nearing port. + +I smell the land. + +It is wise that I should take +in-- and I can't read it. + +But it must be take +in the sails-- + +Therefore on-- + +He's going to sell +his milk cows. + +This is the start of the decline +of agriculture in the + +United States right here, +the family farm. + +This is the high school, now +Newton North, Newton high + +school kind of review +magazine. + +This is 1918. + +A lot of young men are +going over to Europe. + +But it talks about a Newton +high school scientist. + +Of the many capable men on the +defense side of chemical + +warfare service, perhaps none +has contributed more practical + +ideas that Dr. Lewis. + +This is his high school, +hall of fame, kind of. + +This is page 10. + +My kids went to the +same school. + +PROFESSOR: Newton North? + +ROSALIND WILLIAMS: +Yeah, of course. + +OK, this is March 5, 1920. + +PROFESSOR: Of course. + +ROSALIND WILLIAMS: You +got to show spirit. + +PROFESSOR: Of course. + +Boy if live in Newton, +there's a difference. + +I know that. + +ROSALIND WILLIAMS: A +different Newton. + +It matters whether it's +north or south. + +OK, Debbie K. Lewis, required +Course 10, 1920. + +His time here seems +very interesting. + +AUDIENCE: [INAUDIBLE]. + +ROSALIND WILLIAMS: Well, +actually I won't pass this + +around because he-- well, +maybe I will. + +This is Spring Garden farm. + +I showed you the photo +actually earlier. + +OK, here we have-- oh look, +August 5, 1946. + +Anybody know what happened +on August 5, 19-- + +you know what happened +on August 6, 1945? + +It's Hiroshima. + +A year minus a day later, James +R. Killian writes to Dr. + +Compton, during the summer, +there have been a number of + +discussions of the need to +promote here at the Institute, + +more interest in the study of +educational objectives and + +procedures. + +This calls for the Lewis +Commission essentially. + +And it's a letter saying +Lewis should head it. + +And here's some people who +should be on it, and here's + +the budget. + +And then a second letter, +outlining in more detail what + +the Lewis Commission would do. + +It follows shortly thereafter. + +Then I just have a bunch of, +again my grandfather's + +thoughts about the history +of chemical engineering; + +engineering as a profession; my +favorite title, "The Place + +of Engineering in Society and +Civilization." This is from + +Tech Review. + +And I thought you would enjoy +this title, "Chemical + +Engineering, A New Science," +a new science, 1953. + +And so these are all published +in one form or another. + +But then there are letters. + +And there are quite a few +letters to me, to my mother, + +to my father, when my father's +trying to figure out-- this is + +1945 and my father notes that +at GE, so many younger + +engineers are getting offers +from small companies and + +should be thinking about this? + +And my grandfather writes +this long letter + +back, in long hand. + +In 1970, somebody has asked +him for conversations. + +He wants to discuss the +fundamental differences + +between Greek philosophy and +modern science on the purely + +intellectual level. + +And he wants me to come +up and help him write + +something about this. + +And this is very moving because +he says, I am getting + +older and it's hard for people +to understand me. + +You, however, have heard enough +of it over the years so + +you know at least +the direction in + +which my mind is working. + +PROFESSOR: Ah, interesting. + +High compliment. + +ROSALIND WILLIAMS: Yeah. + +It's a huge compliment. + +Anyway, if you don't get +the personality, + +you're missing things. + +Thanksgiving dinner. + +Actually this would be 1963, +the fall of 1963. + +So what happened in +the fall of 1963? + +PROFESSOR: Oh, Kennedy. + +ROSALIND WILLIAMS: It was +right after Kennedy's + +assassination. + +And my grandfather +is saying grace. + +I remember this like +yesterday. + +He had his usual grace and he +gave thanks for the American + +family, because in such +difficult times like these, + +that's the rock on which the +country is founded, the + +American family. + +This is my then boyfriend, +between me and my mother. + +PROFESSOR: It's not Gary. + +ROSALIND WILLIAMS: Yeah, yeah. + +Have you see the actual +Lewis Report? + +PROFESSOR: I have +never seen that. + +ROSALIND WILLIAMS: It's nice, +nice binding job. + +And this is A Dollar to a +Doughnut, which are stories + +about my grandfather's +teaching. + +And this is what the chemical +engineering department put + +together for him when he retired +as a feitschrift, + +because they felt the normal, +staid one was not appropriate + +for such a character. + +PROFESSOR: What year +did he retire? + +ROSALIND WILLIAMS: Well, this +is the official retirement. + +So this is like 1950 or so. + +But as I say, he's like Leo. + +He just kept teaching. + +This is a CD. + +Just so you know, in the +archives they have-- this is + +from tape, the original +tape, now on CD. + +At the 50th anniversary of the +Department of Chemical + +Engineering, so in 1970, +he gave a talk about + +reminiscences and the +fascinating history of + +chemical engineering in the 19th +century, where he has a + +whole theory about the time +lag between discovery and + +implementation, both in +electrical and chemical + +engineering. + +For example, the role of +batteries in running the + +telegraph system, which I had +never thought about it as an + +incentive to chemical +engineering. + +ROSALIND WILLIAMS: Oh, +very interesting. + +AUDIENCE: You know the great +mentors of the chemical + +industry that got [INAUDIBLE]? + +PROFESSOR: No. + +AUDIENCE: Paper making. + +A lot of early involvement. + +[INAUDIBLE] + +to some degree, much less than +they were a national center of + +paper making. + +A lot of the early MIT chemical +engineers were with + +the paper industry. + +ROSALIND WILLIAMS: I +didn't know that. + +And this last thing, and I +bring this along just in + +serendipity. + +This is an obituary in 1975. + +He died on March 9. + +This is the Tech Talk, +when we used to have + +a printed MIT newspaper. + +But what struck me +as I was picking + +it up, OK, an obituary. + +And then I look on the back of +the first page, "Response + +Awaited on Proposal to Train +Iranian Nuclear Engineers." + +And it just struck me, this +is why I love hard copy. + +Because you' come across +things you don't + +plan to come across. + +And this is a reminder +of this is happening. + +And of course this had my +attention, but on the back we + +were being friendly with Iran. + +The Shah was still around. + +OK. + +So that's my show and tell. + +Do you have any questions? + +PROFESSOR: Yeah. + +Thank you for bringing +all this stuff. + +ROSALIND WILLIAMS: Well, +I just love stuff. + +PROFESSOR: It reminds me that +I think historians have a + +special feeling for +stuff like this. + +But I remember when I was +working on my dissertation at + +the National Archives, I was +writing about a topic that + +dated back to the end +of the War of 1812. + +So it was a long time ago. + +And I was getting materials out +of the archives that were + +still bound in the original +red tape. + +And you'd pull those strings +apart and they would + +disintegrate. + +I don't know, it's a weird +feeling thinking that I'm the + +first one to look at the stuff +in over 200 years. + +ROSALIND WILLIAMS: It's kind +of creepy, but it's also + +exhilarating. + +PROFESSOR: Yeah, it is. + +ROSALIND WILLIAMS: Exploration, +right. + +PROFESSOR: And then we had a +colleague that Ros and I knew, + +and I think you may have +known him too, David. + +His name was Brooke Hindle. + +He was the former director of +the Museum of American History + +at the Smithsonian. + +But he wrote an article one time +called "What is a Piece + +of the True Cross Worth." Do +you remember that article, + +about the importance of +artifacts in the study of + +technology particularly? + +ROSALIND WILLIAMS: The story +is that they had four + +children, two daughters, +two sons. + +The other daughter, besides my +mother, Mary, married a guy + +named Cherry Emerson, who +went into plastics + +after World War II. + +Plastics, and to quote Chambers, +made quite a bit of + +money in chemical engineering. + +And he studied with Doc +during the war. + +So he gave the money to renovate +the library, naming + +it in honor of my grandmother, +Warren K Lewis' wife. + +And he always claimed +it was because she + +loved music so much. + +And I must say I never +heard her listen + +or talk about music. + +So I think it was more +Cherry's love + +of music, than her's. + +But that doesn't matter. + +I think it's a great library. + +And I think my grandmother would +particularly be happy + +that students can sleep +on the couches there. + +She's a very gentle soul. + +AUDIENCE: Does anybody here have +parents who went to MIT + +or other relatives? + +So one think you do see is, +any institution that lasts + +this long has this kind +of family connection. + +Universities are sort of famous +for keeping track of + +that sort of thig. + +And that's true among +faculty, as well. + +And there's the genealogies +of our blood families. + +And then we'll talk a bit about +this, but not to much + +explicitly yet. + +We'll talk about it in the +second half, the academic + +genealogies of so and so's +teacher was so and so's + +student, was so and +so's student, + +was so and so's student. + +And then our colleague, Leo +Marx, who was my teacher, Who + +said that, how does it go? + +His adviser from Harvard in the +'40s-- it's only two steps + +back to Ralph Waldo Emerson. + +You can trace four academic +generations today from Leo + +Marx to Ralph Waldo Emerson. + +I'm sure there are people +here, some of the senior + +faculty who were students +of your grandfather's. + +ROSALIND WILLIAMS: If +I go to Chemical + +Engineering, they just-- + +oh, Warren K-- + +AUDIENCE: And that's a person +who started here in 1896. + +And more than 100 years later, +there are still that person's + +students around. + +ROSALIND WILLIAMS: That's been +a great been pleasure of + +university life. + +It's a sense of continuity. + +I mean it would drive +me crazy too. + +PROFESSOR: Ros, your grandfather +was born in + +Delaware and pretty +much raised there. + +He obviously was a +religious person. + +What persuasion? + +ROSALIND WILLIAMS: I think in +Delaware, he was Methodist. + +PROFESSOR: Methodist. + +Yeah, that makes sense. + +ROSALIND WILLIAMS: And one of +the most fascinating books I + +have is of an uncle of his who +was a Methodist circuit rider + +in Delaware, in the 1850s, +setting up black churches. + +They were separate,-- + +PROFESSOR: Really. + +ROSALIND WILLIAMS: --but +setting them up. + +Oh, it's fascinating. + +And my grandfather then joined +the Congregational church up + +here, Elliott church +in Newton. + +Because Methodism up here is a +little different from what it + +was in the South. + +But you get the point. + +It's a low church. + +It's not Episcopalian. + +And he taught Sunday school +every Sunday, + +as long as he could. + +And his religious faith +meant a lot to him. + +He was not a fundamentalist, +at all. + +He said, I take the Bible +seriously, but not literally. + +But I mean he knew his +Bible up one side + +and down the other. + +And it was really fundamental +to him. + +In his old age, he became good +friends with John Crocker, who + +was the Episcopal chaplain +here at MIT. + +And they had a lot of talks. + +And I mean again, I think maybe +whether it was guilt + +about the Manhattan Project or +just trying to kind of talk + +about matters of faith and +other matters too. + +So Crocker led his funeral +service, which I was glad that + +he was able to do. + +So I think religion is one of +the great untapped kind of + +untapped, unappreciated sources +of motivation at MIT. + +And I don't think my +grandfather's unusual. + +And it's not necessarily any +particular religion. + +But people from outside MIT are +always amazed to find how + +strong the religious groups are +here and how many there + +are and how active they are. + +It's not their vision of MIT, +but it's very true. + +OK. + +ROSALIND WILLIAMS: Well, +thank you very much. + +PROFESSOR: Thank +you very much. + +PROFESSOR: OK, I want to just +talk today a little bit more + +about the '30s, the +'20s and the '30s. + +And again, kind of like Ros's +talk, use a specific case of a + +particular faculty member and +a particular machine to + +illustrate some of the general +ideas about where MIT moved + +between about 1925 and 1935 and +why that's interesting. + +And you of course know from the +readings, and the more you + +look at this, everybody says it +and the more I read about + +it, the more you really feel +like Karl Compton coming here + +in 1930 was a major +turning point. + +There was this kind of +internal warfare. + +What was the word that Lewis +used, hot fights about the + +relation of science +and engineering. + +And the Corporation definitely +has an opinion about it. + +And one thing they do-- + +they don't have a lot of control +over the faculty, but + +they do decide who +the president is. + +And so they bring +in Karl Compton. + +He's 42 years old-- + +and it probably sounds +old to you. + +It sounds young to me-- + +in 1930. + +And one of the young people who +was already here was this + +guy then Vannevar Bush, who +we've also heard about, and + +we'll hear about a bunch more, +who was a young electrical + +engineering professor. + +And he was building this +device called a + +differential analyzer. + +And what I want to do today-- +this is again, a sort of + +prototype for what a paper topic +might be, is to look at + +this instrument and how this +instrument was handled and how + +the instrument itself changed +as the goals of the + +Institution changed, from the +'20s through the '30s. + +So here's Bush and there's +the analyzer. + +And when we go to the MIT +Museum, one of the 150 objects + +is that part of the +analyzer that's in + +the wooden box there. + +I'll tell you more about +what that is. + +But it's sitting right there +on the front of the floor. + +And when I was first doing this +research, I asked them if + +they had a piece of it and +they didn't really know. + +And Debbie Douglas and I went +back in the storerooms and we + +found that the original +integrator was there. + +So if you go into the +1920s, Bush is here. + +He's a young professor. + +He had gotten his Ph.D. here. + +And he was a student of +Kennelly, who I mentioned + +before, who was Edison's +assistant. + +And they were very much in the +kind of technology plan world + +of MIT, solving problems for +big industrial partners. + +And what is the problem that +the big industrial partners + +are having? + +Well, in the electrical world, +and you've got to remember + +electrical engineering for a-- + +how people here are Core 6, +in one way or another? + +OK, so about a third. + +Electrical engineering, for its +first 100 years, really + +was electrical, without a lot of +electronics or any of that + +solid state physics +or certainly no + +computers and stuff. + +It was building big machines +to make big generators, and + +big generators, transmission +lines, large electric motors, + +to drive factories and other +kinds of things. + +And anybody ever hear of the +IEEE, Institute of Electrical + +and Electronic Engineers? + +This is a little +bit of trivia. + +But there was the AIEE, +American Institute of + +Electrical Engineers. + +Those are the big electric +power people. + +In fact, in German universities +they still divide + +the curriculum into big signals +and a little signals. + +And so big signals +was the AIEE. + +Little signals was the IRE, +Institute of Radio + +Engineering, lots of little +tiny, little small signals. + +And in 1964, they merged +in the IEEE. + +It's to electrical and +electronic engineers. + +Even though it's probably one of +the two major professional + +societies for computation, but +the word "computer" doesn't + +appear in the title at all. + +And so, this is back in the +days of electric power. + +And the problem with the +electric power industry is the + +electric generators start out as +basically local phenomena. + +A local entrepreneur will build +a generator, either a + +hydro plant or steam powered, +in one way or + +another, in a town. + +And they'll create lighting in +the town and maybe run some + +motors in factories. + +And it's all centralized and +it was all nonuniform. + +Every town had a different + +voltage, a different frequency. + +Some of them were running +on direct current versus + +alternating current. + +These are all big battles they +were having at the time. + +But over the course of the +teens and the '20s, those + +systems are becoming +standardized and they're + +becoming connected into what +today we would call grids. + +So they have a big electric +power grid. + +And they're not quite +national yet, but + +they're very much regional. + +And so in the '20s, General +Electric starts to build a big + +grid that brings hydroelectric +power from in Canada and also + +from Niagara Falls, through +very, very long transmission + +lines, hundreds and hundreds +of miles, down into the New + +York City area, which is where +most of the population and + +most of the energy +usage is from. + +And those lines begin +to have problems. + +And the problems are, if you've +got either a lightning + +strike at one part of the line, +you had a bad electrical + +storm, or even if you had a +short circuit and part of the + +grid tripped off and had just to +sort of save itself, you'd + +get these transients +on the line. + +And the transients would +travel great distances. + +They were just like big wave +power spikes on the line and + +create blackouts all +over the place. + +And there a couple of famous +blackouts that happened in the + +early '20s that really +caused a big problem. + +So this was like a critical +issue about how do you figure + +out, how do you model the +performance of these systems + +under this kind of stress? + +And General Electric, and this +has come up in the readings in + +places, had a very close +relationship with MIT. + +There were a lot of young +engineers who would go there, + +what they called on-test, +to Schenectady. + +In fact, that's where +Ros's father worked. + +I don't if she mention that, +Doc Lewis's son went to + +Schenectady and worked +for General Electric. + +And then they would come back +to MIT sometimes, to get a + +master's degree. + +And they began looking at this +problem of how do you + +understand these systems. + +Now, Bush had done earlier work +in his career, which was + +also based on this whole +idea of modeling. + +I may have mentioned +this before where-- + +how many of you have taken an +engineering class where you + +use a spring mass damper +system and model a RLC + +circuit with it? + +Ring a bell for anybody? + +OK, maybe a few too +many times. + +Or, there are other analogies, +different kinds + +of hydraulic analogies. + +Well, that whole idea basically +comes from the first + +book that Vannevar Bush wrote, +which is called Operational + +Circuit Analysis, where first +of all he applies a thing + +called Oliver Heaviside's +operational calculus. + +Anybody ever heard of the +Heaviside step function? + +And Heaviside was a sort of +somewhat outlandish English + +engineer around the turn of the +century, who came up with + +these ideas. + +Mathematicians didn't like them +because they couldn't + +prove they were valid. + +Heaviside just didn't care about +it at all because he + +could show that they +were useful. + +And they told you a lot about +how transients go down lines. + +And Bush really took the +Heaviside work and he put it + +on a rigorous mathematical +foundation. + +And said among other things, +you can use these analogies + +and you can model a second order +system in any of these + +different fields with +a set of equations. + +And that can be either RLC +circuit or a spring mass + +damper or there are also +hydraulic versions of it, I'm + +sure any number of other ones. + +And what that basic idea allows +you to do is to make + +models of different +kinds of circuits. + +And so what they said +is here's this + +electric power problem. + +Let's look at this problem and +let's build a model of it. + +And what this thing is, is +called a network analyzer. + +And this picture is probably +about 1927. + +And all it is, is-- well, first +thing they make a model + +of just the electric +power line between + +Niagara Falls and Boston. + +So there might be a couple of +generators on the line in + +Niagara Falls, then there's a +long transmission line, then + +there's a whole bunch of +different users, and maybe you + +make one circuit that's +50,000 times + +smaller than the original. + +And you use that as a model. + +And anybody know what +the big problem + +with that was actually? + +The hardest thing about making +these small models was + +measuring the output. + +If you go to the actual electric +power system and you + +put a voltmeter on the line, +that voltmeter is going to + +load the line by some amount. + +But it's negligible, it +really has no impact. + +If you make it 50,000 times +smaller, you've still got the + +same voltmeter. + +And you put it on the line and +it's the equivalent of like + +putting a whole factory +on the line. + +And it affects the performance +of it in ways + +that it wouldn't otherwise. + +So it's one thing to +make this model. + +And they did that rather +successfully and it helped + +them describe. + +And they then reported the +results to GE, this is how the + +thing would behave under +a lightning strike. + +And these are some strategies +you can take to make it a + +little more robust. + +Well, once the word out about +that, all these different + +power companies came and +said, we would like you + +to model our system. + +And so what did they do? + +Did they constantly build +a new one for + +everybody's power system? + +No. + +They built a little set up. + +Actually, I don't even have to +draw it, because it's here. + +Where they said OK, we're going +to put a bunch of models + +of transmission lines and a +bunch of models of generators + +and a bunch of models +of other things. + +And they're actually connected +together by + +telephone plug boards. + +And you bring your system here +and we'll plug it together in + +a certain way, much +like a telephone + +operator connects circuits. + +At that time, it was +done manually. + +And we'll create this thing. + +And this thing, they actually +called it a network computer, + +which is a nice word for it, +that comes up later in MIT + +culture, about 50 years later. + +And electric power companies +would come here. + +And students would write their +theses by designing this + +system and describing it for +a particular power company. + +And saying here, I modeled +your circuit. + +And this thing actually +was around until the + +'50s, it turns out. + +We'll talk about it getting shut +down when Gordon Brown + +shut it down. + +But it was again this kind of +classic MIT in the 1920s, + +early '30s, model of close +relationships with industry, + +solving very particular +problems, almost in a literal + +consulting role. + +Tell us what your issue is? + +We'll model it and we'll help +you solve the problem. + +So we read a lot about that. + +Then there was another approach, +which was to + +calculate the progress of these +transients directly. + +And how did they do that? + +Well, they could do it +analytically with algebra. + +It was extremely difficult +because it was not easy to + +write the equations. + +But it was much easier +to build an analog + +computer to model it. + +And it turned out, and you +probably recognize this, that + +the integral of the product +of two functions + +is a critical piece. + +Today, you find it in all kinds +of signals processing + +and convolution algorithms. + +And they said we'll build +basically these machines that + +will model the key +function of it. + +And this is an early version +of it, which is also a + +specific machine modeled +to evaluate + +the specific integral. + +They called it a product +intergraph. + +And it didn't use equations +at all. + +It just took curves in +and drew curves out. + +There you can see Bush. + +This is actually the output +device, which + +is a watt/hour meter. + +Why would they use +a watt/hour meter + +from an electric utility? + +Because a watt/hour meter does +the same thing, right. + +It evaluates the integral of +the product of the current. + +And the voltage is the +amount of power that + +you get billed for. + +So they take this thing and +they just stick there. + +And then there's these kind of +funky mechanical linkages. + +And there's all these +people involved. + +And actually they have +big high-power + +resistors, so they use a-- + +anybody want to guess what +that thing hanging + +up on the top is? + +AUDIENCE: Radiator. + +PROFESSOR: Close. + +AUDIENCE: Radiator. + +PROFESSOR: It's a +radiator, from? + +AUDIENCE: Model T. + +PROFESSOR: It's a radiator +from a Model T Ford, that + +they're using to provide cooling +water to this machine, + +which evaluates this particular +integral for this + +particular electric +power problem. + +In fact, some of these +are Bush's students. + +This one particularly is a guy +named Harold Hazen, who we + +will talk about later. + +In fact, he's also the guy +sitting in the middle there, + +in that picture. + +Here's another picture of it. + +You can see the watt/hour meter, +just taken right out of + +an electric power measurement +facility. + +Again, you sort of work +with what you have. + +They were working with +electric companies. + +They had these electrical +things, a whole bunch of + +different motor and gears +and interconnections. + +And this was probably +in Building-- + +somewhere in the main group. + +I'm forgetting exactly. + +Building 10, I believe +was this lab. + +I liked, you still have the +pencil sharpener there. + +This is probably the one part +of what was in the lab that + +you might still find in +a laboratory today. + +There's a picture +of Bush with it. + +You can see he looks +pretty young. + +And so there's the +first product + +intergraph, is this device. + +And what it does is all those +little graph chart holders + +basically, move under these +three independent needles. + +And the operators just follow +the first two curves and then + +the output plots the integral +of those two curves. + +So it's literally a graphical +user interface + +for an analog computer. + +And then, they actually bring +it up to one more level of + +complication. + +And there's a way that you can +make it solve a differential + +equation, as well as just +evaluating an integral. + +And so this thing is called the +second product intergraph, + +where it's the same +kind of thing. + +There's two different pieces and +then you can sort of tie + +the output back to the input. + +And this is about where things +stood when Karl Compton + +becomes president of MIT. + +And Compton basically says, +we're not going to do that + +kind of stuff anymore. + +It's too focused on +just one problem. + +It's too simple. + +And Bush responds in a +very energetic way. + +And he builds this machine +about 1931. + +And this is called the +differential analyzer. + +Anybody ever heard of +that term before? + +And really it's kind of nothing +more than this, but + +made in a fully general +purpose way. + +Or like I mentioned before, they +did with the simulator, + +they first started building a +custom one and then they built + +a general one. + +And what you see here is, these +guys here are called + +integrators. + +That's the core of +the problem. + +Again, it's primarily an +integral thing you're trying + +to evaluate. + +An integrator is nothing more +than, they call it a wheel and + +disk integrator. + +There's a disk that +spins around. + +In a mechanical sense, that's +just a transmission, but a + +continuously variable one. + +Then there's a wheel that sits +on the transmission. + +And if the disk is spinning at +a fixed rate and the wheel + +goes in and out, the number of +turns on the upper end of + +wheel is the integral of the +curve of the position of the + +wheel that pulls it off. + +But it's a very simple idea +mechanically, very hard to do + +that in a way that +is mechanically + +robust and very accurate. + +And that's the piece-- + +actually it was so critical to +make it accurate, they covered + +these with those wooden boxes. + +That's the piece that's +in the MIT Museum. + +And then there's all these +other elements. + +I may have a picture of it. + +So there are all these +other elements. + +You can take these integrators +and then you have a + +multiplier, which is nothing but +a gear that connects one + +rod to another in a ratio. + +And you have these rods that +go through the middle. + +They're almost like the +bus on a computer. + +And you can connect these things +in all different ways + +to evaluate a particular +equation. + +In this case, this is just a +second order equation for a + +falling body problem. + +But you can mix and match this +thing and essentially program + +it by rebuilding it around +these connecting rods. + +And so, I'll show you a couple +of pictures of the-- + +oops. + +Here is another view +of the integrator. + +Here you can see the +disk and the little + +wheel that takes off. + +It actually has a real +knife edge on it, to + +try to make it accurate. + +One of the real problems with +those integrators is that they + +can't drive much of a load. + +If they slip at all, they +lose a lot of accuracy. + +So here they have put these +things called torque + +amplifiers, which are these very +clunky, exotic, kind of + +cached in like devices that +amplify the torque. + +And then they connect them in. + +And where you might have in an +electrical analog computer, + +there's a voltage that gets +pushed around, in a mechanical + +analogue computer it's just the +rotation of these shafts + +that carry the data from +one place to another. + +And they do that by going into +this matrix of mechanical rods + +that you see over there +on the left. + +And each time they wanted, they +could kind of reprogram + +the whole thing. + +And here's another shot. + +So here's a gear ratio that +would perform the + +multiplication. + +You can see that this stuff is +beautifully machined, very + +interesting and carefully +done. + +Yeah? + +AUDIENCE: And they were doing +this in the electrical + +department. + +PROFESSOR: This is in electrical +engineering + +department, right. + +AUDIENCE: It seems very much +like a mechanical project. + +PROFESSOR: It does seem like +a mechanical project. + +That's a very good point. + +And Bush actually said, he was +very clear, he said, I want my + +engineers to be able to design +mathematical equations the way + +they design circuits. + +And he tried to make a +circuit design-type + +language, visual language-- + +I redrew this picture. + +But I redrew it from one +of their papers. + +It's the same terminology-- + +that you could actually design +these equations and make these + +big kind of systems. + +And already you're beginning +to see a move toward + +generality. + +So he says, this is not a device +to evaluate integrals + +for studying transience in the +electric power industry. + +This is a research device +for a general + +purpose calculating machine. + +And it's interesting, he goes +to the Rockefeller-- + +well, I'll cover that +in a minute. + +So already you're beginning to +see this guy beginning to + +think in a more general, kind +of fundamental terms, as + +opposed to in these +specific terms. + +And this is within just a couple +of years of Compton + +coming here to MIT. + +Here's the output +of the device. + +You can see it's basically +creating a family of curves. + +And they were very into +the fact that they + +didn't need any algebra. + +They didn't need +any equations. + +They said the world is +basically analog. + +They didn't use that term. + +And said, the world +is continuous. + +Our integrator is +continuous and + +produces continuous outputs. + +And again, you can +see this kind of + +graphical user interface. + +There's a little magnifying +glass there. + +And he's kind of following these +curves, which was a kind + +of manual input. + +Bush is kind of looking over +the shoulder there. + +And they would evaluate +all these + +different kinds of curves. + +Here's another view, where +they're all connected by an + +electrical audio system. + +And there's one guy in the +center, telling everybody OK, + +follow your curves now. + +And here, he's not doing it +by hand so much anymore. + +He's turning a little crank +to trace all the curves. + +And you can begin to see by the +curves, they can do some + +pretty complicated things. + +And there's a whole kind of +science of analog computing + +that comes up in the '30s around +these machines, where + +they measure the number of +integrators the way you would + +measure the number of megahertz +of processor that + +you have in your computer. + +Because the integrator was the +expensive thing that kind of + +described what order equation +you could possibly model with + +these things. + +And people start to use them +to model electron orbits in + +atomic physics. + +They used them particularly +for ballistics. + +The Army gets really +interested. + +And they have to calculate +ballistic equations for all + +different kinds of +guns and shells. + +And this makes it a lot +more convenient. + +And so you begin to see the move +away from, even with the + +same research group, the same +people literally, from this + +kind of specific industry +oriented work toward more + +general work in what +they think of as a + +general purpose computing. + +This is kind of the most famous +picture of the device. + +And you can see there +three integrators + +inside their glass cases. + +Those integrated became so +precise that you had to have + +them covered, free of dust, and + +really very well protected. + +And it turns out there was a +integrator that was developed + +secretly by the Navy for +controlling the big guns on + +battleships, that was better +than this one, that they + +weren't really aware yet. + +And has nobody ever see +a tubal integrator? + +It's a whole other kind of +mechanism that you can use to + +do mechanical integration. + +So then this project spurs a +whole bunch of different other + +kinds of projects. + +One is called the cinema +intergraph, where the idea is + +instead of integrating with +these kind of problematic + +mechanical integrators, you +integrate using this exotic + +new technology. + +Anybody want to guess what +that is over on the left? + +It's a photo cell. + +And they would actually plot +the mathematical curves as + +images on this 35 +millimeter film. + +And then shine a light through +it and plot the area under the + +curves by integrating the charge +that came through the + +photo cell. + +And this is the guy +who made it. + +As he said, it was mostly +a machine for producing + +dissertations. + +It had essentially no +practical output. + +But it was important in that, +this guy is named Gordon + +Brown, who is a student of +Harold Hazen, and becomes the + +dean of engineering right +at the end of the + +Second World War. + +And is the guy who closes down +all that old-fashioned + +electrical machinery. + +We read about him +a little bit. + +I think it was in the +[? Laquier ?] + +article. + +And kind of is the dean of +engineering when they kind of + +formalized a lot of things after +the Second World War. + +And there's another picture +of the cinema intergraph. + +Also one of his advisers on +there was Norbert Wiener, who + +was also very closely related +to Bush's work. + +And a lot of his earlier ideas +of cybernetics also came out + +of this work. + +This is Harold Hazen again. + +It's called an automatic +curve follower. + +And his idea is, gee, maybe I +could make these photo cells + +just follow these curves +automatically. + +And today, you can go to the +Science Museum and buy a + +little robot kit with a +robot that follows a + +line across the floor. + +This is the first +one of those. + +But what's much more interesting +and important than + +that about this, was that in +order to do this and order to + +make the differential analyzer +work, it's the amount of + +friction that builds up +in the mechanisms. + +And it gets to a point where you +basically just can't turn + +the crank anymore. + +And you start to lose +a lot of accuracy. + +You don't lose it +in the gears. + +Eventually you would, because +they would break. + +But you lose it in all these +other systems, particularly + +the integrator. + +So what they do is they put what +they call followers or + +servomechanisms between the +stages, where they can kind of + +renew the signal and add +energy to the system. + +Because with a mechanical +system, if you don't have any + +energy, it's just going +to eventually-- + +the energy is all dissipated. + +But if you can carry the data +from one point to another and + +just add energy and make it +constantly stronger, you can + +build them as big as you want. + +And it's between that problem +and this problem that Hazen + +actually writes the first paper +ever on what he calls + +the theory of servomechanisms, +which you now what know as + +feedback control theory. + +And anybody take a course on +that, or probably in every + +engineering course you're taking +something in feedback + +control theory. + +And he became interested in +these basic problems. + +Until that point, people had +governors on steam engines. + +They had different kinds of +regulators in this electric + +power network they +were working on. + +But nobody had thought of, let's +write about the theory + +of how this feedback mechanism +works overall. + +And there again, there's another +one of these, a little + +more detailed example of an +intellectual way that + +Compton's move was not just +administrative, he didn't just + +say let's stop working +with industry + +and think about science. + +He actually influenced these +people in their labs very + +quickly, within a couple years, +to start thinking about + +fundamental problems as opposed +to just these kind of + +immediate problems. + +Hazen also becomes dean of +engineering at MIT during the + +Second World War and head of +the electrical engineering + +department. + +Here's his model of +servomechanisms. + +Also in that group, looking at +again this electric power + +problem, and saw something +literally in the electrical + +power problem that was +bigger than simply + +the immediate problem. + +Anybody want to get +who this is? + +Let me describe what +he's doing and + +maybe then you'll guess? + +So you can actually see in this +picture, he says, I'm + +going to look at these +generators. + +And the problem is when +they have these + +transients of these-- + +they fall out of step, so that +in an A/C system, everything + +has to be running in +perfect synchrony. + +And if it's not running +synchronized, you get all + +kinds of issues. + +And he says, I'm going to tape +cardboard N and S. So that I'm + +going to tape them to each of +the poles on the generator and + +then let the generator +spin really fast. + +And then I'm going to shine a +light on it and I'm going to + +pulse the light at exactly +the same frequency as the + +generator is supposed +to be spinning. + +And that will freeze the +N and S in your eye + +when you look at it. + +And then if there's a phasing +problem, you'll see the N and + +the S moving back and forth. + +Now, anybody want to +guess who this is? + +AUDIENCE: Edgerton. + +PROFESSOR: This is +Edgerton, right? + +And this is the first +application he have of this + +stroboscope. + +And very soon, he says hey, +you know what, this + +stroboscope thing is +really interesting. + +I can make some innovations +there. + +Forget about electric +power stuff. + +I'm interested in high-speed +photography and generally + +high-speed electrical +discharge. + +AUDIENCE: It's like the first +timing light for a car. + +PROFESSOR: Yeah. + +It's exactly the same as the +timing light for a car. + +Most of which are made +by EG&G, which + +was Edgerton's company. + +And so there again, he gets +interested in a bunch of + +different things. + +But all of them have in common +this idea of like how even + +most of the flashes-- + +you don't see it so much in your +digital camera, with the + +little teeny ones. + +But if you ever have a big +flash, it fires and then you + +hear it charging up. + +And then it fires all again. + +And Edgerton really became an +expert at very rapid discharge + +of electrical energy. + +I work a lot at the Undersea +World, where Edgerton did a + +lot of work with sonar. + +But the particular kind of sonar +he built was very much + +like the flash bulb, in +that it was a sonar + +that flashed the sound. + +It's called side-scan sonar, +rather than continuous wave + +sonar, would just gave +it all the time. + +So for the plutonium bomb in +particular, the one during + +World War II, and I think they +still are spherical, and you + +had to implode this device. + +And a guy at Harvard, +Kistiakowsky, made these + +explosive lenses. + +And you had to trigger them +all around this sphere at + +exactly the same moment. + +Otherwise, you were going to get +a lopsided shock wave and + +you weren't going to implode +the thing perfectly. + +And it was Edgerton's company +that designed the triggering + +mechanisms for that +atomic bomb. + +They also did high-speed +photography of the actual + +mushroom clouds. + +And it's amazing, sort of +frightening imagery that + +they've collected all through +the Cold War about that. + +And that was EG&G. It was +founded by Edgerton, + +Germeshausen, and Grier, +two of his colleagues. + +And the-- let's see, +what is it-- + +Building 37 is the building +they gave. + +And there's a Grier room and +the Germeshausen room. + +And I forget which the +auditorium is called. + +But that work started here. + +And then Edgerton +developed that. + +And interestingly, one of the +students, a guy named Marty + +Klein, who is the sort of the +father of that side-scan + +sonar, is a good +friend of mine. + +And he always says, Edgerton +was a time domain man. + +He never thought in the +frequency domain. + +For those of you who are +EEs, you'll know + +what that refers to. + +And that really came out this +legacy from Bush's lab of + +thinking about transience +on these lines. + +There's nothing to say about +electric power systems in the + +frequency domain, because +it's all 60 Hertz. + +It's all exactly the same +frequency, unlike radio which + +is all about frequency domain. + +He thought in the time domain. + +And everything about +the electronics-- + +anybody work in the Edgerton +lab these days or + +take a class there? + +All that stuff is time domain +stuff, kind of epitomized by + +the high-speed photography. + +Here's an image again of the +Army getting interested at the + +Aberdeen Proving Ground, down +in Maryland, which did a lot + +of the measurement +for ballistics. + +They bought five or six of these +or they hired people and + +they made their own +copies of them. + +Within a few years, during the +'30s, they were all over the + +place, not just in +electric power. + +Yeah? + +AUDIENCE: When do you begin +to see military + +funding of this work? + +Does it start with Bush's +differential? + +No, OK. + +PROFESSOR: Really not +until the war. + +So I'll come to the funding +issue in a second, because + +it's pretty interesting. + +They also, with Bush's +consulting, built the control + +system for the Palomar +telescope, which at the time + +was the biggest telescope +ever built. + +It didn't even become +operational until after the + +Second World War. + +Anybody ever been there? + +It's in California, outside +of San Diego. + +And you have this enormous, +three-story high telescope. + +And you've got to point it +with great accuracy. + +And it actually had a lot of +similarities to the problems + +they were working on there. + +So there's also a funding +story here. + +Warren Weaver is also +mentioned in the-- + +I'm forgetting if it was the +Servos or the [? Laquier ?] + +article from the Rockefeller +Foundation. + +And they talk about it. + +It was [? Laquier. ?] + +He said, as soon as Compton +came in, he went to the + +Rockefeller Foundation and said, +I need $175,000 for this + +new initiative. + +And if you guys back +me on this-- + +at the time, there was no +National Science Foundation. + +There was no public money other +than from the military, + +available for research. + +But the Rockefeller Foundation +was basically the equivalent + +of the NSF today, a +private foundation + +handing out these checks. + +And Bush went to Weaver. + +And he went to Weaver with +this early version of the + +differential analyzer. + +And it was about 1931. + +And Weaver says, +not interested. + +That engineering stuff is best +handled by industrial funding. + +We don't support anything +that looks + +like engineering research. + +We only support fundamental +research. + +Why don't you go find an +electric power company or + +somebody to give it to you? + +Two years later, Bush goes back +to Weaver and says oh, + +this is not a machine for +electric power research. + +This is a machine for + +fundamental research in computing. + +And Weaver says, oh, well if +you're going to put it that + +way, here's $100,000. + +At the depths of the Depression, +that a lot of + +money for a research program, +far beyond what anybody-- in + +fact, I think there's a +statistic in there that before + +the war, the entire federal +funding for all of MIT was + +only $40,000 a year. + +And they gave Bush, not just +$100,000, but about $250,000 + +in the middle of the '30s, to +build the next version, which + +became known as the Rockefeller + +differential analyzer. + +And here you see, it looks a +little bit more sophisticated. + +Instead of those earlier tables, +they called them input + +tables, here you have +a rotating drum. + +There's still a person required +to sit there and turn + +the handle. + +But the basic model was +a lot more electrical. + +And also interestingly, the +operators of these machines + +changed from men to women. + +So they're no longer graduate +students operating them. + +They're much more what they +called human computers at the + +time, operating them. + +But you can see there, +a similar idea. + +There are curves on this drum. + +The person looks at the curves +and is providing the input to + +the machine by matching the +pointer to the curve. + +And the way this machine +worked, is also really + +interesting. + +A lot like the other one, but +instead of that matrix of + +circular rods in the middle, +it's a crossbar switch. + +Anybody know what industry a +crossbar switch comes from? + +It's a telephone switch. + +And its electrical switch that +basically says, I got all + +these inputs across the top and +all these inputs across + +the bottom. + +I can connect anyone to anyone, +in fact in this case + +using a punched paper tape. + +And so they get the +prototype crossbar + +switch from Bell Labs. + +It was a pretty big revolution +in telephone + +switching at the time. + +They had built this crossbar +and donated it to MIT. + +And what they did was they +said, we're just going to + +adapt each of these mechanical +elements-- in fact, the + +integrators were still +mechanical-- + +but we're going to give them +electrical outputs. + +Instead of the quantities +being represented by the + +rotation angle of the +rod, it's now + +represented by a voltage. + +We'll feed all the voltages +into the crossbar switch. + +And then you configure the +crossbar switch by reading a + +paper tape into it. + +And so you can basically model +any equation by some set of + +switch closings on the crossbar +switch and you + +program those by a paper tape. + +And now, you're beginning to see +the beginning of digital + +switching coming into -- there +wasn't even a word for + +"digital" at the time-- + +coming into this idea of +analogue computing. + +And so then the problem for the +programmer becomes, they + +have this continuous analog +equation across the top. + +I need to translate it into +these paper tapes. + +And that's kind of an +interesting problem, how do I + +think about the transformation +from a set of equations into a + +set of switch closures? + +And this young master student +looks at it and he says well, + +I can actually make +this kind of-- + +he calls it a relay algebra. + +And I'm going to design a little +kind of mechanical + +notation that will allow me +to design these circuits. + +And you know that totally +useless stuff that I studied + +in mathematics they called +Boolean algebra, from the 19th + +century, is actually kind +of useful here. + +And I'm going to call a closed +switch, a 1 and an open + +switch, a 0. + +And that allows you to +manipulate the whole thing + +mathematically. + +Anybody know who this is? + +You maybe the name flash by. + +AUDIENCE: You mean +Claude Shannon? + +PROFESSOR: Yeah, it's actually +Claude Shannon, writes his + +master's thesis on exactly +this problem. + +And many people call this the +most significant master's + +thesis ever written in +electrical engineering. + +The master's thesis basically +lays down the entire + +groundwork for the design of +digital systems in 1936 and + +based on the problems that are +raised by designing this + +computational machine. + +And he immediately gets hired by +Bell Labs and starts to go + +work there and think about how +to design switching circuits. + +And the kind of counterpart at +Bell Labs right at that moment + +reads this thesis and says, I'm +going to call this kind of + +electronics digital. + +And actually invents the word +"digital" to describe that + +kind of electronics. + +So here's a case of-- + +again, 1936, Karl Compton +has only been + +at MIT for six years. + +But he's already pushed this +particular laboratory and this + +particular set of students to +start thinking about their + +work in a different way. + +Much less specific to one +industry specific to solving + +particular applications, and +more generally thinking about + +the fundamentals, the +mathematics, with applications + +to lots and lots +of other areas. + +So that's just one case there, +I thought I would show you. + +And then, all those people are +also then people who get very + +involved in the early +digital computing. + +Once the war starts, basically +they all go to + +Washington with Bush. + +Some of them stay here and +get very involved. + +But we'll cover that in the next +time we actually meet. + +Questions, comments +about that? + +AUDIENCE: Is that the same +servomechanism laboratory that + +goes and creates +the Whirlwind? + +PROFESSOR: Yeah. + +The earlier question, it's +exactly that laboratory. + +So Gordon Brown starts +the Servomechanism + +Laboratory in 1940. + +He the first course ever +on feedback control + +theory at MIT in 1939. + +And he writes this one paper. + +In fact, it's called "Transient +Analysis of + +Servomechanisms." So it still +carries that transient idea + +from the early electric +power work. + +And Warren Weaver shows up in +his lab and says, guess what? + +I work for the government now. + +I don't work for the + +Rockefeller Foundation anymore. + +That paper that you just wrote, +that you're about to + +publish, it's classified. + +You're not allowed to +publish it anymore. + +And here's $500,000 +to start your lab. + +And Brown sort of takes it in. + +And if it happens for an +historian, very valuable that + +they classified that paper. + +Because then, anyone who +got a copy of it, + +had to sign it out. + +So he writes this fundamental +paper. + +And then you can actually trace +week by week, out in the + +community, who's reading the +paper and see how they are + +changing their work. + +And they begin to have this +idea, again if you look at + +feedback control, there's +governors on steam engines. + +There's regulators +on arc lights. + +There's automatic pilots +in airplanes. + +And is even feedback amplifiers +in electrical + +engineering. + +But there's nobody who says, +hey, you know what, all that + +stuff is really the same. + +And now, we take for granted +as that's what you study in + +control theory. + +You don't study any one +of those areas. + +You study the basic +phenomenon. + +And that was the beginning +of what Brown was doing. + +And it was really a coincidence +that right about + +that moment, it goes underground +and it stays + +underground for the whole war. + +And that's really where when +Norbert Wiener comes out in + +1948, and says, cybernetics, +feedback control, it's all + +about this, he was just saying +something that had been secret + +for eight years already +at that point. + +But one of the things that got +me interested in this research + +was, why was MIT's first digital +computer made by the + +Servomechanisms Lab? + +Because you don't necessarily +associate those two + +things in your mind. + +A servo, you think of as an +analog, mechanical thing and a + +digital computer as this +funny electronic thing. + +But during the war, it sort of-- +it actually happens after + +the war, but right +after the war. \ No newline at end of file diff --git a/SAgWL1G5Bcw.txt b/SAgWL1G5Bcw.txt new file mode 100644 index 0000000000000000000000000000000000000000..71ab374aec1a3520ef47c2d67914738c0b66f196 --- /dev/null +++ b/SAgWL1G5Bcw.txt @@ -0,0 +1,1507 @@ +align:start position:0% + +my name is an margules I'm the executive + + align:start position:0% +my name is an margules I'm the executive + + + align:start position:0% +my name is an margules I'm the executive +director of MIT open courseware in our + + align:start position:0% +director of MIT open courseware in our + + + align:start position:0% +director of MIT open courseware in our +session on open courseware you'll + + align:start position:0% +session on open courseware you'll + + + align:start position:0% +session on open courseware you'll +actually be spending some time on the + + align:start position:0% +actually be spending some time on the + + + align:start position:0% +actually be spending some time on the +site but I'll describe also how open + + align:start position:0% +site but I'll describe also how open + + + align:start position:0% +site but I'll describe also how open +courseware was developed a little bit + + align:start position:0% +courseware was developed a little bit + + + align:start position:0% +courseware was developed a little bit +about its history and we'll talk about + + align:start position:0% +about its history and we'll talk about + + + align:start position:0% +about its history and we'll talk about +some of the challenges for open + + align:start position:0% +some of the challenges for open + + + align:start position:0% +some of the challenges for open +courseware going forward for now I'd + + align:start position:0% +courseware going forward for now I'd + + + align:start position:0% +courseware going forward for now I'd +like to tell you a little bit about what + + align:start position:0% +like to tell you a little bit about what + + + align:start position:0% +like to tell you a little bit about what +open course Weare is and also share with + + align:start position:0% +open course Weare is and also share with + + + align:start position:0% +open course Weare is and also share with +you some of our experience with our + + align:start position:0% +you some of our experience with our + + + align:start position:0% +you some of our experience with our +first public launch of the site I'll + + align:start position:0% +first public launch of the site I'll + + + align:start position:0% +first public launch of the site I'll +then post some of the questions or the + + align:start position:0% +then post some of the questions or the + + + align:start position:0% +then post some of the questions or the +challenges we're facing in the area of + + align:start position:0% +challenges we're facing in the area of + + + align:start position:0% +challenges we're facing in the area of +access and + + align:start position:0% +access and + + + align:start position:0% +access and +sustainability MIT open courseware was + + align:start position:0% +sustainability MIT open courseware was + + + align:start position:0% +sustainability MIT open courseware was +announced about a year and a half ago + + align:start position:0% +announced about a year and a half ago + + + align:start position:0% +announced about a year and a half ago +with an overwhelmingly positive response + + align:start position:0% +with an overwhelmingly positive response + + + align:start position:0% +with an overwhelmingly positive response +with that tremendous response however + + align:start position:0% +with that tremendous response however + + + align:start position:0% +with that tremendous response however +came a lot of confusion about what MIT + + align:start position:0% +came a lot of confusion about what MIT + + + align:start position:0% +came a lot of confusion about what MIT +open courseware is and what it + + align:start position:0% +open courseware is and what it + + + align:start position:0% +open courseware is and what it +isn't oh CW is a large-scale web-based + + align:start position:0% +isn't oh CW is a large-scale web-based + + + align:start position:0% +isn't oh CW is a large-scale web-based +publication of all of mit's course + + align:start position:0% +publication of all of mit's course + + + align:start position:0% +publication of all of mit's course +materials offered to the world for + + align:start position:0% +materials offered to the world for + + + align:start position:0% +materials offered to the world for +free it's intended to be a new model for + + align:start position:0% +free it's intended to be a new model for + + + align:start position:0% +free it's intended to be a new model for +the open sharing of information and it + + align:start position:0% +the open sharing of information and it + + + align:start position:0% +the open sharing of information and it +is not intended to replace the real + + align:start position:0% +is not intended to replace the real + + + align:start position:0% +is not intended to replace the real +education that happens in the classroom + + align:start position:0% +education that happens in the classroom + + + align:start position:0% +education that happens in the classroom +that is the interaction between faculty + + align:start position:0% +that is the interaction between faculty + + + align:start position:0% +that is the interaction between faculty +and students and between + + align:start position:0% +and students and between + + + align:start position:0% +and students and between +students open courseware is not degree + + align:start position:0% +students open courseware is not degree + + + align:start position:0% +students open courseware is not degree +granting and it is not distance + + align:start position:0% +granting and it is not distance + + + align:start position:0% +granting and it is not distance +education when you visit the open + + align:start position:0% +education when you visit the open + + + align:start position:0% +education when you visit the open +courseware site what you will see is a + + align:start position:0% +courseware site what you will see is a + + + align:start position:0% +courseware site what you will see is a +depth and a breadth of materials that's + + align:start position:0% +depth and a breadth of materials that's + + + align:start position:0% +depth and a breadth of materials that's +different from what you see on other + + align:start position:0% +different from what you see on other + + + align:start position:0% +different from what you see on other +campus websites in terms of breadth + + align:start position:0% +campus websites in terms of breadth + + + align:start position:0% +campus websites in terms of breadth +we're publishing courses from all five + + align:start position:0% +we're publishing courses from all five + + + align:start position:0% +we're publishing courses from all five +of MIT + + align:start position:0% +of MIT + + + align:start position:0% +of MIT +schools we're also over time going to be + + align:start position:0% +schools we're also over time going to be + + + align:start position:0% +schools we're also over time going to be +publishing subjects or courses from all + + align:start position:0% +publishing subjects or courses from all + + + align:start position:0% +publishing subjects or courses from all +of mit's academic + + align:start position:0% + + + + align:start position:0% + +units many people say so what's the big + + align:start position:0% +units many people say so what's the big + + + align:start position:0% +units many people say so what's the big +deal lots of courses or subjects have + + align:start position:0% +deal lots of courses or subjects have + + + align:start position:0% +deal lots of courses or subjects have +websites what's unique about MIT open + + align:start position:0% +websites what's unique about MIT open + + + align:start position:0% +websites what's unique about MIT open +course Weare is truly the depth of the + + align:start position:0% +course Weare is truly the depth of the + + + align:start position:0% +course Weare is truly the depth of the +materials a typical subject site to use + + align:start position:0% +materials a typical subject site to use + + + align:start position:0% +materials a typical subject site to use +M mit's vernacular would include a + + align:start position:0% +M mit's vernacular would include a + + + align:start position:0% +M mit's vernacular would include a +course description a calendar a syllabus + + align:start position:0% +course description a calendar a syllabus + + + align:start position:0% +course description a calendar a syllabus +if it's a lecture based course it will + + align:start position:0% +if it's a lecture based course it will + + + align:start position:0% +if it's a lecture based course it will +include all of the lecture notes it's if + + align:start position:0% +include all of the lecture notes it's if + + + align:start position:0% +include all of the lecture notes it's if +a if it is a lab it will include the lab + + align:start position:0% +a if it is a lab it will include the lab + + + align:start position:0% +a if it is a lab it will include the lab +instructions and often all the tools if + + align:start position:0% +instructions and often all the tools if + + + align:start position:0% +instructions and often all the tools if +there software tools that are needed for + + align:start position:0% +there software tools that are needed for + + + align:start position:0% +there software tools that are needed for +that lab there are also related reading + + align:start position:0% +that lab there are also related reading + + + align:start position:0% +that lab there are also related reading +materials quizzes exams problem sets + + align:start position:0% +materials quizzes exams problem sets + + + align:start position:0% +materials quizzes exams problem sets +solution sets and so on there are also + + align:start position:0% +solution sets and so on there are also + + + align:start position:0% +solution sets and so on there are also +many different types of materials + + align:start position:0% +many different types of materials + + + align:start position:0% +many different types of materials +included on the site there are P the + + align:start position:0% +included on the site there are P the + + + align:start position:0% +included on the site there are P the +most common are text files PDF or HTML + + align:start position:0% +most common are text files PDF or HTML + + + align:start position:0% +most common are text files PDF or HTML +with lots of images graphs and charts + + align:start position:0% +with lots of images graphs and charts + + + align:start position:0% +with lots of images graphs and charts +but we also have simulations software + + align:start position:0% +but we also have simulations software + + + align:start position:0% +but we also have simulations software +tools tools and many + + align:start position:0% +tools tools and many + + + align:start position:0% +tools tools and many +other uh learning objects embedded in + + align:start position:0% +other uh learning objects embedded in + + + align:start position:0% +other uh learning objects embedded in +the + + align:start position:0% +the + + + align:start position:0% +the +site so that's what ocw is we just + + align:start position:0% +site so that's what ocw is we just + + + align:start position:0% +site so that's what ocw is we just +launched the site uh three weeks ago we + + align:start position:0% +launched the site uh three weeks ago we + + + align:start position:0% +launched the site uh three weeks ago we +actually opened the site to the public + + align:start position:0% +actually opened the site to the public + + + align:start position:0% +actually opened the site to the public +we did it very quietly because we didn't + + align:start position:0% +we did it very quietly because we didn't + + + align:start position:0% +we did it very quietly because we didn't +know what to expect people's + + align:start position:0% +know what to expect people's + + + align:start position:0% +know what to expect people's +expectations were so high we didn't know + + align:start position:0% +expectations were so high we didn't know + + + align:start position:0% +expectations were so high we didn't know +if what we were publishing was going to + + align:start position:0% +if what we were publishing was going to + + + align:start position:0% +if what we were publishing was going to +meet those expectations the good news is + + align:start position:0% +meet those expectations the good news is + + + align:start position:0% +meet those expectations the good news is +we've received once again an over inly + + align:start position:0% +we've received once again an over inly + + + align:start position:0% +we've received once again an over inly +positive response over 40 million there + + align:start position:0% +positive response over 40 million there + + + align:start position:0% +positive response over 40 million there +have been over 40 million hits to the + + align:start position:0% +have been over 40 million hits to the + + + align:start position:0% +have been over 40 million hits to the +site we've had from over 3,000 people + + align:start position:0% +site we've had from over 3,000 people + + + align:start position:0% +site we've had from over 3,000 people +and over + + align:start position:0% +and over + + + align:start position:0% +and over +3,000 email messages have been received + + align:start position:0% +3,000 email messages have been received + + + align:start position:0% +3,000 email messages have been received +those email messages have given us lots + + align:start position:0% +those email messages have given us lots + + + align:start position:0% +those email messages have given us lots +of important feedback regarding how + + align:start position:0% +of important feedback regarding how + + + align:start position:0% +of important feedback regarding how +people are going to use the site it's + + align:start position:0% +people are going to use the site it's + + + align:start position:0% +people are going to use the site it's +too early to tell what the impact on + + align:start position:0% +too early to tell what the impact on + + + align:start position:0% +too early to tell what the impact on +learning will be from open courseware + + align:start position:0% +learning will be from open courseware + + + align:start position:0% +learning will be from open courseware +but we know from messages people have + + align:start position:0% +but we know from messages people have + + + align:start position:0% +but we know from messages people have +sent us that Educators see tremendous + + align:start position:0% +sent us that Educators see tremendous + + + align:start position:0% +sent us that Educators see tremendous +value in being able to use the site to + + align:start position:0% +value in being able to use the site to + + + align:start position:0% +value in being able to use the site to +be able to build upon the work of others + + align:start position:0% +be able to build upon the work of others + + + align:start position:0% +be able to build upon the work of others +they can now spend their energy on + + align:start position:0% +they can now spend their energy on + + + align:start position:0% +they can now spend their energy on +creating new ideas instead of + + align:start position:0% +creating new ideas instead of + + + align:start position:0% +creating new ideas instead of +Reinventing ideas that other people have + + align:start position:0% +Reinventing ideas that other people have + + + align:start position:0% +Reinventing ideas that other people have +already done quite well educators are + + align:start position:0% +already done quite well educators are + + + align:start position:0% +already done quite well educators are +also interested in using ocw to be able + + align:start position:0% +also interested in using ocw to be able + + + align:start position:0% +also interested in using ocw to be able +to share best teaching practices so we + + align:start position:0% +to share best teaching practices so we + + + align:start position:0% +to share best teaching practices so we +expect over time for the for there to be + + align:start position:0% +expect over time for the for there to be + + + align:start position:0% +expect over time for the for there to be +much more + + align:start position:0% +much more + + + align:start position:0% +much more +collaboration and potentially much more + + align:start position:0% +collaboration and potentially much more + + + align:start position:0% +collaboration and potentially much more +Innovation many self-learners have also + + align:start position:0% +Innovation many self-learners have also + + + align:start position:0% +Innovation many self-learners have also +visited the site and told us some of the + + align:start position:0% +visited the site and told us some of the + + + align:start position:0% +visited the site and told us some of the +ways that they'll be using it + + align:start position:0% +ways that they'll be using it + + + align:start position:0% +ways that they'll be using it +self-learners are coming to ocw to + + align:start position:0% +self-learners are coming to ocw to + + + align:start position:0% +self-learners are coming to ocw to +explore whole new areas of study as well + + align:start position:0% +explore whole new areas of study as well + + + align:start position:0% +explore whole new areas of study as well +as to brush up on subjects that they + + align:start position:0% +as to brush up on subjects that they + + + align:start position:0% +as to brush up on subjects that they +took a while ago and perhaps have gotten + + align:start position:0% +took a while ago and perhaps have gotten + + + align:start position:0% +took a while ago and perhaps have gotten +rust + + align:start position:0% +rust + + + align:start position:0% +rust +on self- Learners have also told us that + + align:start position:0% +on self- Learners have also told us that + + + align:start position:0% +on self- Learners have also told us that +they e eager to come to ocw often in + + align:start position:0% +they e eager to come to ocw often in + + + align:start position:0% +they e eager to come to ocw often in +order to keep current on the latest on + + align:start position:0% +order to keep current on the latest on + + + align:start position:0% +order to keep current on the latest on +the latest thinking in their field we'll + + align:start position:0% +the latest thinking in their field we'll + + + align:start position:0% +the latest thinking in their field we'll +be measuring over time more about how + + align:start position:0% +be measuring over time more about how + + + align:start position:0% +be measuring over time more about how +people are using the site and what their + + align:start position:0% +people are using the site and what their + + + align:start position:0% +people are using the site and what their +impact may be in class we'll have more + + align:start position:0% +impact may be in class we'll have more + + + align:start position:0% +impact may be in class we'll have more +data to present to you and we'll be + + align:start position:0% +data to present to you and we'll be + + + align:start position:0% +data to present to you and we'll be +eager to talk about some of the ways + + align:start position:0% +eager to talk about some of the ways + + + align:start position:0% +eager to talk about some of the ways +that people will be using the site and + + align:start position:0% +that people will be using the site and + + + align:start position:0% +that people will be using the site and +what the potential impact will be we + + align:start position:0% +what the potential impact will be we + + + align:start position:0% +what the potential impact will be we +have great hopes for ocw but they're + + align:start position:0% +have great hopes for ocw but they're + + + align:start position:0% +have great hopes for ocw but they're +also great challenges our first area of + + align:start position:0% +also great challenges our first area of + + + align:start position:0% +also great challenges our first area of +challenge is in Access we can think of + + align:start position:0% +challenge is in Access we can think of + + + align:start position:0% +challenge is in Access we can think of +accessing two ways there's technical + + align:start position:0% +accessing two ways there's technical + + + align:start position:0% +accessing two ways there's technical +access just how do you get to the site + + align:start position:0% +access just how do you get to the site + + + align:start position:0% +access just how do you get to the site +and then there's cultural access let's + + align:start position:0% +and then there's cultural access let's + + + align:start position:0% +and then there's cultural access let's +talk first about technical + + align:start position:0% +talk first about technical + + + align:start position:0% +talk first about technical +access although people have accessed the + + align:start position:0% +access although people have accessed the + + + align:start position:0% +access although people have accessed the +site from 177 different countries there + + align:start position:0% +site from 177 different countries there + + + align:start position:0% +site from 177 different countries there +are plenty of remote Villages and other + + align:start position:0% +are plenty of remote Villages and other + + + align:start position:0% +are plenty of remote Villages and other +locations that just don't have the + + align:start position:0% +locations that just don't have the + + + align:start position:0% +locations that just don't have the +network infrastructure need needed to be + + align:start position:0% +network infrastructure need needed to be + + + align:start position:0% +network infrastructure need needed to be +able to truly access all the depth in + + align:start position:0% +able to truly access all the depth in + + + align:start position:0% +able to truly access all the depth in +open course Weare what should we do + + align:start position:0% +open course Weare what should we do + + + align:start position:0% +open course Weare what should we do +about that we'll talk about that when we + + align:start position:0% +about that we'll talk about that when we + + + align:start position:0% +about that we'll talk about that when we +get together cultural access is perhaps + + align:start position:0% +get together cultural access is perhaps + + + align:start position:0% +get together cultural access is perhaps +even more + + align:start position:0% +even more + + + align:start position:0% +even more +challenging those areas that are most + + align:start position:0% +challenging those areas that are most + + + align:start position:0% +challenging those areas that are most +eager to get to the content say they + + align:start position:0% +eager to get to the content say they + + + align:start position:0% +eager to get to the content say they +might have difficulty using it because + + align:start position:0% +might have difficulty using it because + + + align:start position:0% +might have difficulty using it because +it's not in their language or it might + + align:start position:0% +it's not in their language or it might + + + align:start position:0% +it's not in their language or it might +not make sense within their culture what + + align:start position:0% +not make sense within their culture what + + + align:start position:0% +not make sense within their culture what +should we in open courseware do to + + align:start position:0% +should we in open courseware do to + + + align:start position:0% +should we in open courseware do to +either encourage or facilitate local + + align:start position:0% +either encourage or facilitate local + + + align:start position:0% +either encourage or facilitate local +adaptations of the + + align:start position:0% + + + + align:start position:0% + +materials with any Innovation it's + + align:start position:0% +materials with any Innovation it's + + + align:start position:0% +materials with any Innovation it's +important not only to launch it properly + + align:start position:0% +important not only to launch it properly + + + align:start position:0% +important not only to launch it properly +but also to consider how to sustain it + + align:start position:0% +but also to consider how to sustain it + + + align:start position:0% +but also to consider how to sustain it +over + + align:start position:0% +over + + + align:start position:0% +over +time we + + align:start position:0% +time we + + + align:start position:0% +time we +know that many of the for profit models + + align:start position:0% +know that many of the for profit models + + + align:start position:0% +know that many of the for profit models +have struggled in fact many of them have + + align:start position:0% +have struggled in fact many of them have + + + align:start position:0% +have struggled in fact many of them have +folded and I would be willing to predict + + align:start position:0% +folded and I would be willing to predict + + + align:start position:0% +folded and I would be willing to predict +that many still will not make it and + + align:start position:0% +that many still will not make it and + + + align:start position:0% +that many still will not make it and +will + + align:start position:0% +will + + + align:start position:0% +will +fold how do we make the for free model + + align:start position:0% +fold how do we make the for free model + + + align:start position:0% +fold how do we make the for free model +survive and be sustainable over + + align:start position:0% +survive and be sustainable over + + + align:start position:0% +survive and be sustainable over +time let's think about it in terms of + + align:start position:0% +time let's think about it in terms of + + + align:start position:0% +time let's think about it in terms of +the local level and then perhaps at the + + align:start position:0% +the local level and then perhaps at the + + + align:start position:0% +the local level and then perhaps at the +national and international level at the + + align:start position:0% +national and international level at the + + + align:start position:0% +national and international level at the +local level for ocw to survive and to be + + align:start position:0% +local level for ocw to survive and to be + + + align:start position:0% +local level for ocw to survive and to be +sustainable it first of all has to be + + align:start position:0% +sustainable it first of all has to be + + + align:start position:0% +sustainable it first of all has to be +part of the way our faculty work it has + + align:start position:0% +part of the way our faculty work it has + + + align:start position:0% +part of the way our faculty work it has +to be part of their normal way of + + align:start position:0% +to be part of their normal way of + + + align:start position:0% +to be part of their normal way of +preparing their course materials + + align:start position:0% +preparing their course materials + + + align:start position:0% +preparing their course materials +ocw will not succeed if we place any + + align:start position:0% +ocw will not succeed if we place any + + + align:start position:0% +ocw will not succeed if we place any +additional burden on the + + align:start position:0% +additional burden on the + + + align:start position:0% +additional burden on the +faculty secondly we need to be as + + align:start position:0% +faculty secondly we need to be as + + + align:start position:0% +faculty secondly we need to be as +efficient and as cost effective as + + align:start position:0% +efficient and as cost effective as + + + align:start position:0% +efficient and as cost effective as +possible so that there aren't barriers + + align:start position:0% +possible so that there aren't barriers + + + align:start position:0% +possible so that there aren't barriers +for other campuses to join in the + + align:start position:0% +for other campuses to join in the + + + align:start position:0% +for other campuses to join in the +effort which takes us to the next level + + align:start position:0% +effort which takes us to the next level + + + align:start position:0% +effort which takes us to the next level +of concern around + + align:start position:0% +of concern around + + + align:start position:0% +of concern around +sustainability if our vision is truly + + align:start position:0% +sustainability if our vision is truly + + + align:start position:0% +sustainability if our vision is truly +realized and there are open coursewares + + align:start position:0% +realized and there are open coursewares + + + align:start position:0% +realized and there are open coursewares +not just in MIT but on every campus if + + align:start position:0% +not just in MIT but on every campus if + + + align:start position:0% +not just in MIT but on every campus if +open courseware becomes a a real + + align:start position:0% +open courseware becomes a a real + + + align:start position:0% +open courseware becomes a a real +movement then how do we allow people to + + align:start position:0% +movement then how do we allow people to + + + align:start position:0% +movement then how do we allow people to +navigate across different open course + + align:start position:0% +navigate across different open course + + + align:start position:0% +navigate across different open course +word platforms there will need to be + + align:start position:0% +word platforms there will need to be + + + align:start position:0% +word platforms there will need to be +some kind of organizing structures or + + align:start position:0% +some kind of organizing structures or + + + align:start position:0% +some kind of organizing structures or +Frameworks or standard bodies that exist + + align:start position:0% +Frameworks or standard bodies that exist + + + align:start position:0% +Frameworks or standard bodies that exist +to coordinate that in class I'd love to + + align:start position:0% +to coordinate that in class I'd love to + + + align:start position:0% +to coordinate that in class I'd love to +hear your ideas about how we here at + + align:start position:0% +hear your ideas about how we here at + + + align:start position:0% +hear your ideas about how we here at +Team might help lead that + + align:start position:0% +Team might help lead that + + + align:start position:0% +Team might help lead that +effort those are just a few of the many + + align:start position:0% +effort those are just a few of the many + + + align:start position:0% +effort those are just a few of the many +challenges we face in the future we're + + align:start position:0% +challenges we face in the future we're + + + align:start position:0% +challenges we face in the future we're +really just at the very beginning of + + align:start position:0% +really just at the very beginning of + + + align:start position:0% +really just at the very beginning of +open courseware but it's a very exciting + + align:start position:0% +open courseware but it's a very exciting + + + align:start position:0% +open courseware but it's a very exciting +time and I look forward to seeing you + + align:start position:0% +time and I look forward to seeing you + + + align:start position:0% +time and I look forward to seeing you +class seeing you in class and we'll talk + + align:start position:0% +class seeing you in class and we'll talk + + + align:start position:0% +class seeing you in class and we'll talk +more about this thank you \ No newline at end of file diff --git a/SbtqjZk80Qc.txt b/SbtqjZk80Qc.txt new file mode 100644 index 0000000000000000000000000000000000000000..f5d1e84b8d57334deb771279da7876d40629636b --- /dev/null +++ b/SbtqjZk80Qc.txt @@ -0,0 +1,13251 @@ +align:start position:0% + +one more lecture from me and so remember + + align:start position:0% +one more lecture from me and so remember + + + align:start position:0% +one more lecture from me and so remember +then on Thursday we'll be here and Chris + + align:start position:0% +then on Thursday we'll be here and Chris + + + align:start position:0% +then on Thursday we'll be here and Chris +Wolverton from Ford will be + + align:start position:0% +Wolverton from Ford will be + + + align:start position:0% +Wolverton from Ford will be +lecturing Straight live direct from Fort + + align:start position:0% +lecturing Straight live direct from Fort + + + align:start position:0% +lecturing Straight live direct from Fort +and so you better have good questions + + align:start position:0% +and so you better have good questions + + + align:start position:0% +and so you better have good questions +for him because he only lectures about + + align:start position:0% +for him because he only lectures about + + + align:start position:0% +for him because he only lectures about +an hour and so we usually in the past + + align:start position:0% +an hour and so we usually in the past + + + align:start position:0% +an hour and so we usually in the past +we've had quite some good discussion + + align:start position:0% +we've had quite some good discussion + + + align:start position:0% +we've had quite some good discussion +afterwards but that's going to depend on + + align:start position:0% +afterwards but that's going to depend on + + + align:start position:0% +afterwards but that's going to depend on +you um so what I'm going to do today is + + align:start position:0% +you um so what I'm going to do today is + + + align:start position:0% +you um so what I'm going to do today is +um a variety of topics but they all have + + align:start position:0% +um a variety of topics but they all have + + + align:start position:0% +um a variety of topics but they all have +to kind of do with the same idea of + + align:start position:0% +to kind of do with the same idea of + + + align:start position:0% +to kind of do with the same idea of +bigger and faster and better not + + align:start position:0% +bigger and faster and better not + + + align:start position:0% +bigger and faster and better not +necessarily better but um + + align:start position:0% + + + + align:start position:0% + +so you know when you deal with atoms uh + + align:start position:0% +so you know when you deal with atoms uh + + + align:start position:0% +so you know when you deal with atoms uh +both because of the size and the time um + + align:start position:0% +both because of the size and the time um + + + align:start position:0% +both because of the size and the time um +if you go away especially if you go away + + align:start position:0% +if you go away especially if you go away + + + align:start position:0% +if you go away especially if you go away +from periodic systems uh you'll always + + align:start position:0% +from periodic systems uh you'll always + + + align:start position:0% +from periodic systems uh you'll always +run into this problem that it's um too + + align:start position:0% +run into this problem that it's um too + + + align:start position:0% +run into this problem that it's um too +small your system that the simulation is + + align:start position:0% +small your system that the simulation is + + + align:start position:0% +small your system that the simulation is +too short um I always like to quote + + align:start position:0% +too short um I always like to quote + + + align:start position:0% +too short um I always like to quote +Professor marzari on this when people + + align:start position:0% +Professor marzari on this when people + + + align:start position:0% +Professor marzari on this when people +come to him with Nano Nano problems and + + align:start position:0% +come to him with Nano Nano problems and + + + align:start position:0% +come to him with Nano Nano problems and +he always says Nano is just a little too + + align:start position:0% +he always says Nano is just a little too + + + align:start position:0% +he always says Nano is just a little too +big for us um and so I think that's + + align:start position:0% +big for us um and so I think that's + + + align:start position:0% +big for us um and so I think that's +telling you something about the state of + + align:start position:0% +telling you something about the state of + + + align:start position:0% +telling you something about the state of +what we do um so what you've actually + + align:start position:0% +what we do um so what you've actually + + + align:start position:0% +what we do um so what you've actually +seen certain Solutions already to the + + align:start position:0% +seen certain Solutions already to the + + + align:start position:0% +seen certain Solutions already to the +sort of size and time problem um maybe + + align:start position:0% +sort of size and time problem um maybe + + + align:start position:0% +sort of size and time problem um maybe +they were fairly obvious but if you + + align:start position:0% +they were fairly obvious but if you + + + align:start position:0% +they were fairly obvious but if you +think of the time + + align:start position:0% +think of the time + + + align:start position:0% +think of the time +problem um what I've already showed you + + align:start position:0% +problem um what I've already showed you + + + align:start position:0% +problem um what I've already showed you +is how to essentially Co grain that away + + align:start position:0% +is how to essentially Co grain that away + + + align:start position:0% +is how to essentially Co grain that away +um which is it's one thing to C grain + + align:start position:0% +um which is it's one thing to C grain + + + align:start position:0% +um which is it's one thing to C grain +over time and space it's another thing + + align:start position:0% +over time and space it's another thing + + + align:start position:0% +over time and space it's another thing +and it's actually easier to almost + + align:start position:0% +and it's actually easier to almost + + + align:start position:0% +and it's actually easier to almost +remove it by integrating it away and + + align:start position:0% +remove it by integrating it away and + + + align:start position:0% +remove it by integrating it away and +when you essentially integrate time away + + align:start position:0% +when you essentially integrate time away + + + align:start position:0% +when you essentially integrate time away +completely you end up with + + align:start position:0% +completely you end up with + + + align:start position:0% +completely you end up with +thermodynamics I mean think about that's + + align:start position:0% +thermodynamics I mean think about that's + + + align:start position:0% +thermodynamics I mean think about that's +what integration over the partition + + align:start position:0% +what integration over the partition + + + align:start position:0% +what integration over the partition +function is you're essentially assuming + + align:start position:0% +function is you're essentially assuming + + + align:start position:0% +function is you're essentially assuming +the system has had enough time to sample + + align:start position:0% +the system has had enough time to sample + + + align:start position:0% +the system has had enough time to sample +all its excitations so you essentially + + align:start position:0% +all its excitations so you essentially + + + align:start position:0% +all its excitations so you essentially +integrate over that Ensemble you + + align:start position:0% +integrate over that Ensemble you + + + align:start position:0% +integrate over that Ensemble you +integrate over all the excitations and + + align:start position:0% +integrate over all the excitations and + + + align:start position:0% +integrate over all the excitations and +you end up with the thermodynamic + + align:start position:0% +you end up with the thermodynamic + + + align:start position:0% +you end up with the thermodynamic +functions and the examples that I showed + + align:start position:0% +functions and the examples that I showed + + + align:start position:0% +functions and the examples that I showed +you with the cluster expansion were + + align:start position:0% +you with the cluster expansion were + + + align:start position:0% +you with the cluster expansion were +essentially examples like that so that + + align:start position:0% +essentially examples like that so that + + + align:start position:0% +essentially examples like that so that +part I would say for crystalline system + + align:start position:0% +part I would say for crystalline system + + + align:start position:0% +part I would say for crystalline system +is a solved problem it's not a trivial + + align:start position:0% +is a solved problem it's not a trivial + + + align:start position:0% +is a solved problem it's not a trivial +solution it's still a lot of work but + + align:start position:0% +solution it's still a lot of work but + + + align:start position:0% +solution it's still a lot of work but +it's essentially a solved problem um I + + align:start position:0% +it's essentially a solved problem um I + + + align:start position:0% +it's essentially a solved problem um I +would say most of + + align:start position:0% +would say most of + + + align:start position:0% +would say most of +the spatial problem is solved if you're + + align:start position:0% +the spatial problem is solved if you're + + + align:start position:0% +the spatial problem is solved if you're +going to deal with static properties + + align:start position:0% +going to deal with static properties + + + align:start position:0% +going to deal with static properties +static properties and things such as + + align:start position:0% +static properties and things such as + + + align:start position:0% +static properties and things such as +elastic Behavior + + align:start position:0% +elastic Behavior + + + align:start position:0% +elastic Behavior +uh you know you essentially cor grain + + align:start position:0% +uh you know you essentially cor grain + + + align:start position:0% +uh you know you essentially cor grain +fairly easily and end up with Continuum + + align:start position:0% +fairly easily and end up with Continuum + + + align:start position:0% +fairly easily and end up with Continuum +Theory um the real problem lies in you + + align:start position:0% +Theory um the real problem lies in you + + + align:start position:0% +Theory um the real problem lies in you +know what should have happens in between + + align:start position:0% +know what should have happens in between + + + align:start position:0% +know what should have happens in between +here um when when you want to keep some + + align:start position:0% +here um when when you want to keep some + + + align:start position:0% +here um when when you want to keep some +level of detail that's not Continuum or + + align:start position:0% +level of detail that's not Continuum or + + + align:start position:0% +level of detail that's not Continuum or +that's in the time axis not + + align:start position:0% +that's in the time axis not + + + align:start position:0% +that's in the time axis not +thermodynamic but you can't afford to + + align:start position:0% +thermodynamic but you can't afford to + + + align:start position:0% +thermodynamic but you can't afford to +stay all the way down at the atomistic + + align:start position:0% +stay all the way down at the atomistic + + + align:start position:0% +stay all the way down at the atomistic +scale and the scale of the electrons + + align:start position:0% +scale and the scale of the electrons + + + align:start position:0% +scale and the scale of the electrons +that's where um I think the real + + align:start position:0% +that's where um I think the real + + + align:start position:0% +that's where um I think the real +challenge + + align:start position:0% +challenge + + + align:start position:0% +challenge +exists and I'll tell you a little more + + align:start position:0% +exists and I'll tell you a little more + + + align:start position:0% +exists and I'll tell you a little more +about that + + align:start position:0% +about that + + + align:start position:0% +about that +um that's when you break your + + align:start position:0% + + + + align:start position:0% + +computer um so first I'm going to tell + + align:start position:0% +computer um so first I'm going to tell + + + align:start position:0% +computer um so first I'm going to tell +you there's obviously the Brute Force + + align:start position:0% +you there's obviously the Brute Force + + + align:start position:0% +you there's obviously the Brute Force +approaches um which is you know just + + align:start position:0% +approaches um which is you know just + + + align:start position:0% +approaches um which is you know just +throw more computer power at it and + + align:start position:0% +throw more computer power at it and + + + align:start position:0% +throw more computer power at it and +these days the way you do that is not + + align:start position:0% +these days the way you do that is not + + + align:start position:0% +these days the way you do that is not +buying faster computers you buy more of + + align:start position:0% +buying faster computers you buy more of + + + align:start position:0% +buying faster computers you buy more of +them so you have to parallel + + align:start position:0% +them so you have to parallel + + + align:start position:0% +them so you have to parallel +ize um parallelization over space is + + align:start position:0% +ize um parallelization over space is + + + align:start position:0% +ize um parallelization over space is +obviously the most obvious one if you + + align:start position:0% +obviously the most obvious one if you + + + align:start position:0% +obviously the most obvious one if you +have a really big system you can divide + + align:start position:0% +have a really big system you can divide + + + align:start position:0% +have a really big system you can divide +it in chunks + + align:start position:0% +it in chunks + + + align:start position:0% +it in chunks +okay you know you'd probably do it a + + align:start position:0% +okay you know you'd probably do it a + + + align:start position:0% +okay you know you'd probably do it a +little more systematic but you can + + align:start position:0% +little more systematic but you can + + + align:start position:0% +little more systematic but you can +divide it in chunks and give each chunk + + align:start position:0% +divide it in chunks and give each chunk + + + align:start position:0% +divide it in chunks and give each chunk +of atoms to a CPU you know CPU 1 CPU 2 + + align:start position:0% +of atoms to a CPU you know CPU 1 CPU 2 + + + align:start position:0% +of atoms to a CPU you know CPU 1 CPU 2 +cpu3 + + align:start position:0% + + + + align:start position:0% + +Etc of course what + + align:start position:0% +Etc of course what + + + align:start position:0% +Etc of course what +that means that implies that the + + align:start position:0% +that means that implies that the + + + align:start position:0% +that means that implies that the +coupling between regions is not too + + align:start position:0% +coupling between regions is not too + + + align:start position:0% +coupling between regions is not too +severe because when you + + align:start position:0% +severe because when you + + + align:start position:0% +severe because when you +calculate uh say let's say you're doing + + align:start position:0% +calculate uh say let's say you're doing + + + align:start position:0% +calculate uh say let's say you're doing +molecular Dynamics when you calculate + + align:start position:0% +molecular Dynamics when you calculate + + + align:start position:0% +molecular Dynamics when you calculate +forces on the atoms in the region of + + align:start position:0% +forces on the atoms in the region of + + + align:start position:0% +forces on the atoms in the region of +cpu1 the atoms that live in the boundary + + align:start position:0% +cpu1 the atoms that live in the boundary + + + align:start position:0% +cpu1 the atoms that live in the boundary +layer of obviously + + align:start position:0% +layer of obviously + + + align:start position:0% +layer of obviously +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +see see forces coming from atoms in the + + align:start position:0% +see see forces coming from atoms in the + + + align:start position:0% +see see forces coming from atoms in the +other regions so how efficient this this + + align:start position:0% +other regions so how efficient this this + + + align:start position:0% +other regions so how efficient this this +method is will depend very much on how + + align:start position:0% +method is will depend very much on how + + + align:start position:0% +method is will depend very much on how +well you can divide the sort of spatial + + align:start position:0% +well you can divide the sort of spatial + + + align:start position:0% +well you can divide the sort of spatial +origin of the forces and the energy so + + align:start position:0% +origin of the forces and the energy so + + + align:start position:0% +origin of the forces and the energy so +you can already see that this is going + + align:start position:0% +you can already see that this is going + + + align:start position:0% +you can already see that this is going +to be easier when you do it with pair + + align:start position:0% +to be easier when you do it with pair + + + align:start position:0% +to be easier when you do it with pair +potential say with pair potentials you + + align:start position:0% +potential say with pair potentials you + + + align:start position:0% +potential say with pair potentials you +can directly + + align:start position:0% +can directly + + + align:start position:0% +can directly +assign when you have the force on an + + align:start position:0% +assign when you have the force on an + + + align:start position:0% +assign when you have the force on an +atom the component coming from other + + align:start position:0% +atom the component coming from other + + + align:start position:0% +atom the component coming from other +atoms okay you can say the force on this + + align:start position:0% +atoms okay you can say the force on this + + + align:start position:0% +atoms okay you can say the force on this +atom comes you know have a piece coming + + align:start position:0% +atom comes you know have a piece coming + + + align:start position:0% +atom comes you know have a piece coming +from the potential with that atom the + + align:start position:0% +from the potential with that atom the + + + align:start position:0% +from the potential with that atom the +potential with that atom Etc um you'll + + align:start position:0% +potential with that atom Etc um you'll + + + align:start position:0% +potential with that atom Etc um you'll +see that in the standard approximation + + align:start position:0% +see that in the standard approximation + + + align:start position:0% +see that in the standard approximation +for example to Quantum Mechanics this is + + align:start position:0% +for example to Quantum Mechanics this is + + + align:start position:0% +for example to Quantum Mechanics this is +virtually + + align:start position:0% +virtually + + + align:start position:0% +virtually +impossible when we work with um block + + align:start position:0% +impossible when we work with um block + + + align:start position:0% +impossible when we work with um block +States those are by definition extended + + align:start position:0% +States those are by definition extended + + + align:start position:0% +States those are by definition extended +over the whole + + align:start position:0% +over the whole + + + align:start position:0% +over the whole +system okay so you can partition them + + align:start position:0% +system okay so you can partition them + + + align:start position:0% +system okay so you can partition them +over pieces of space so to do this sort + + align:start position:0% +over pieces of space so to do this sort + + + align:start position:0% +over pieces of space so to do this sort +of divide and coner approach with + + align:start position:0% +of divide and coner approach with + + + align:start position:0% +of divide and coner approach with +quantum mechanics um you have to go to + + align:start position:0% +quantum mechanics um you have to go to + + + align:start position:0% +quantum mechanics um you have to go to +Alternative approaches and these are + + align:start position:0% +Alternative approaches and these are + + + align:start position:0% +Alternative approaches and these are +either um people invest a lot of time + + align:start position:0% +either um people invest a lot of time + + + align:start position:0% +either um people invest a lot of time +now in just real space + + align:start position:0% +now in just real space + + + align:start position:0% +now in just real space +grids uh you know in theory the Shing + + align:start position:0% +grids uh you know in theory the Shing + + + align:start position:0% +grids uh you know in theory the Shing +equation is a partial differential + + align:start position:0% +equation is a partial differential + + + align:start position:0% +equation is a partial differential +equation like any other partial + + align:start position:0% +equation like any other partial + + + align:start position:0% +equation like any other partial +differential equation you should be able + + align:start position:0% +differential equation you should be able + + + align:start position:0% +differential equation you should be able +to solve it on a real space grid there + + align:start position:0% +to solve it on a real space grid there + + + align:start position:0% +to solve it on a real space grid there +Al all kinds of complications that arise + + align:start position:0% +Al all kinds of complications that arise + + + align:start position:0% +Al all kinds of complications that arise +but people are doing a lot there's a lot + + align:start position:0% +but people are doing a lot there's a lot + + + align:start position:0% +but people are doing a lot there's a lot +of work actually being done on that um + + align:start position:0% +of work actually being done on that um + + + align:start position:0% +of work actually being done on that um +the other is to go to localized basis + + align:start position:0% +the other is to go to localized basis + + + align:start position:0% +the other is to go to localized basis +sets and you know one year functions + + align:start position:0% +sets and you know one year functions + + + align:start position:0% +sets and you know one year functions +maximally localized one functions fall + + align:start position:0% +maximally localized one functions fall + + + align:start position:0% +maximally localized one functions fall +in that category and Professor marar is + + align:start position:0% +in that category and Professor marar is + + + align:start position:0% +in that category and Professor marar is +an expert on that almost essentially + + align:start position:0% +an expert on that almost essentially + + + align:start position:0% +an expert on that almost essentially +invented them um uh tight binding + + align:start position:0% +invented them um uh tight binding + + + align:start position:0% +invented them um uh tight binding +approaches so you'll see a lot of work + + align:start position:0% +approaches so you'll see a lot of work + + + align:start position:0% +approaches so you'll see a lot of work +being done on real space methods which + + align:start position:0% +being done on real space methods which + + + align:start position:0% +being done on real space methods which +is in essence directed largely toward + + align:start position:0% +is in essence directed largely toward + + + align:start position:0% +is in essence directed largely toward +this sort of divide and conquer approach + + align:start position:0% +this sort of divide and conquer approach + + + align:start position:0% +this sort of divide and conquer approach +if you can go real space in quantum + + align:start position:0% +if you can go real space in quantum + + + align:start position:0% +if you can go real space in quantum +mechanics you can um divide space up so + + align:start position:0% +mechanics you can um divide space up so + + + align:start position:0% +mechanics you can um divide space up so +space is maybe in the end not the + + align:start position:0% +space is maybe in the end not the + + + align:start position:0% +space is maybe in the end not the +biggest problem we have to deal with um + + align:start position:0% +biggest problem we have to deal with um + + + align:start position:0% +biggest problem we have to deal with um +time is a much harder one because um how + + align:start position:0% +time is a much harder one because um how + + + align:start position:0% +time is a much harder one because um how +do you paralyze over time time is by + + align:start position:0% +do you paralyze over time time is by + + + align:start position:0% +do you paralyze over time time is by +nature sequential + + align:start position:0% +nature sequential + + + align:start position:0% +nature sequential +um so it's really hard to do + + align:start position:0% +um so it's really hard to do + + + align:start position:0% +um so it's really hard to do +something um that's in the future when + + align:start position:0% +something um that's in the future when + + + align:start position:0% +something um that's in the future when +you don't know the present yet um but + + align:start position:0% +you don't know the present yet um but + + + align:start position:0% +you don't know the present yet um but +you'll see in a second uh or not in a + + align:start position:0% +you'll see in a second uh or not in a + + + align:start position:0% +you'll see in a second uh or not in a +second a little more than a second but + + align:start position:0% +second a little more than a second but + + + align:start position:0% +second a little more than a second but +later in the lecture there are some + + align:start position:0% +later in the lecture there are some + + + align:start position:0% +later in the lecture there are some +approaches to paralyzing time but + + align:start position:0% +approaches to paralyzing time but + + + align:start position:0% +approaches to paralyzing time but +they're all I would say much more + + align:start position:0% +they're all I would say much more + + + align:start position:0% +they're all I would say much more +limited in scope um than um than the + + align:start position:0% +limited in scope um than um than the + + + align:start position:0% +limited in scope um than um than the +methods for paralyzing over + + align:start position:0% + + + + align:start position:0% + +space so you see time will be the big + + align:start position:0% +space so you see time will be the big + + + align:start position:0% +space so you see time will be the big +problem time time is easier to deal with + + align:start position:0% +problem time time is easier to deal with + + + align:start position:0% +problem time time is easier to deal with +when it's either short or very long + + align:start position:0% +when it's either short or very long + + + align:start position:0% +when it's either short or very long +because when it's very long you + + align:start position:0% +because when it's very long you + + + align:start position:0% +because when it's very long you +essentially integrate it away but in + + align:start position:0% +essentially integrate it away but in + + + align:start position:0% +essentially integrate it away but in +between is where it uh tends to get + + align:start position:0% + + + + align:start position:0% + +harder so let me give you sort of a + + align:start position:0% +harder so let me give you sort of a + + + align:start position:0% +harder so let me give you sort of a +couple of examples + + align:start position:0% +couple of examples + + + align:start position:0% +couple of examples +of ideas that have been kicked around + + align:start position:0% +of ideas that have been kicked around + + + align:start position:0% +of ideas that have been kicked around +for uh Co graining space and then I'll + + align:start position:0% +for uh Co graining space and then I'll + + + align:start position:0% +for uh Co graining space and then I'll +say a little more about the time and and + + align:start position:0% +say a little more about the time and and + + + align:start position:0% +say a little more about the time and and +with time comes temperature problem so + + align:start position:0% +with time comes temperature problem so + + + align:start position:0% +with time comes temperature problem so +you know you could imagine if you + + align:start position:0% +you know you could imagine if you + + + align:start position:0% +you know you could imagine if you +if you do an impurity calculation so you + + align:start position:0% +if you do an impurity calculation so you + + + align:start position:0% +if you do an impurity calculation so you +know you take a sort of Crystal of these + + align:start position:0% +know you take a sort of Crystal of these + + + align:start position:0% +know you take a sort of Crystal of these +bluish atoms and you stick a big red + + align:start position:0% +bluish atoms and you stick a big red + + + align:start position:0% +bluish atoms and you stick a big red +atom in you you want to calculate the + + align:start position:0% +atom in you you want to calculate the + + + align:start position:0% +atom in you you want to calculate the +energy of that with quantum mechanics + + align:start position:0% +energy of that with quantum mechanics + + + align:start position:0% +energy of that with quantum mechanics +well you know those NE those shells + + align:start position:0% +well you know those NE those shells + + + align:start position:0% +well you know those NE those shells +around the red atom kind of relax a lot + + align:start position:0% +around the red atom kind of relax a lot + + + align:start position:0% +around the red atom kind of relax a lot +and then as you sort of go further uh + + align:start position:0% +and then as you sort of go further uh + + + align:start position:0% +and then as you sort of go further uh +this is largely an elastic problem you + + align:start position:0% +this is largely an elastic problem you + + + align:start position:0% +this is largely an elastic problem you +know you've put a ball in a hole that's + + align:start position:0% +know you've put a ball in a hole that's + + + align:start position:0% +know you've put a ball in a hole that's +too small and sort of the system relaxes + + align:start position:0% +too small and sort of the system relaxes + + + align:start position:0% +too small and sort of the system relaxes +around it um you know we tend to sort + + align:start position:0% +around it um you know we tend to sort + + + align:start position:0% +around it um you know we tend to sort +brute force that typically you know we + + align:start position:0% +brute force that typically you know we + + + align:start position:0% +brute force that typically you know we +do quantum mechanics on bigger and + + align:start position:0% +do quantum mechanics on bigger and + + + align:start position:0% +do quantum mechanics on bigger and +bigger unit cells but it's actually + + align:start position:0% +bigger unit cells but it's actually + + + align:start position:0% +bigger unit cells but it's actually +remarkable if you ever plot the + + align:start position:0% +remarkable if you ever plot the + + + align:start position:0% +remarkable if you ever plot the +displacements um this system be you'll + + align:start position:0% +displacements um this system be you'll + + + align:start position:0% +displacements um this system be you'll +find that these systems behaves + + align:start position:0% +find that these systems behaves + + + align:start position:0% +find that these systems behaves +remarkably elastically in very close + + align:start position:0% +remarkably elastically in very close + + + align:start position:0% +remarkably elastically in very close +shells to the defect already you know + + align:start position:0% +shells to the defect already you know + + + align:start position:0% +shells to the defect already you know +often from the second third neighbor you + + align:start position:0% +often from the second third neighbor you + + + align:start position:0% +often from the second third neighbor you +if you were to apply elasticity Theory + + align:start position:0% +if you were to apply elasticity Theory + + + align:start position:0% +if you were to apply elasticity Theory +you'd still get it right it's amazing + + align:start position:0% +you'd still get it right it's amazing + + + align:start position:0% +you'd still get it right it's amazing +how how applicable elasticity theory is + + align:start position:0% +how how applicable elasticity theory is + + + align:start position:0% +how how applicable elasticity theory is +at the atomistic level um so that gave + + align:start position:0% +at the atomistic level um so that gave + + + align:start position:0% +at the atomistic level um so that gave +people the idea that really when they do + + align:start position:0% +people the idea that really when they do + + + align:start position:0% +people the idea that really when they do +uh calculations with broken symmetry so + + align:start position:0% +uh calculations with broken symmetry so + + + align:start position:0% +uh calculations with broken symmetry so +around defects um maybe you really don't + + align:start position:0% +around defects um maybe you really don't + + + align:start position:0% +around defects um maybe you really don't +need all the atoms that we tend to put + + align:start position:0% +need all the atoms that we tend to put + + + align:start position:0% +need all the atoms that we tend to put +in uh + + align:start position:0% +in uh + + + align:start position:0% +in uh +calculations um so the the idea that's + + align:start position:0% +calculations um so the the idea that's + + + align:start position:0% +calculations um so the the idea that's +been kicked around is that um let's say + + align:start position:0% +been kicked around is that um let's say + + + align:start position:0% +been kicked around is that um let's say +that this is a piece of your + + align:start position:0% +that this is a piece of your + + + align:start position:0% +that this is a piece of your +simulation that's far away from whatever + + align:start position:0% +simulation that's far away from whatever + + + align:start position:0% +simulation that's far away from whatever +perturbation you're looking at you know + + align:start position:0% +perturbation you're looking at you know + + + align:start position:0% +perturbation you're looking at you know +maybe it's a grain boundary maybe it's a + + align:start position:0% +maybe it's a grain boundary maybe it's a + + + align:start position:0% +maybe it's a grain boundary maybe it's a +dislocation moving Maybe youve just uh + + align:start position:0% +dislocation moving Maybe youve just uh + + + align:start position:0% +dislocation moving Maybe youve just uh +you know did nuclear fusion somewhere in + + align:start position:0% +you know did nuclear fusion somewhere in + + + align:start position:0% +you know did nuclear fusion somewhere in +the material um but far away you believe + + align:start position:0% +the material um but far away you believe + + + align:start position:0% +the material um but far away you believe +that the system acts almost in a + + align:start position:0% +that the system acts almost in a + + + align:start position:0% +that the system acts almost in a +Continuum mode and so the idea is that + + align:start position:0% +Continuum mode and so the idea is that + + + align:start position:0% +Continuum mode and so the idea is that +what if I kept track only of these red + + align:start position:0% + + + + align:start position:0% + +atoms if I knew say let's say I'm + + align:start position:0% +atoms if I knew say let's say I'm + + + align:start position:0% +atoms if I knew say let's say I'm +looking at you know at energy of an + + align:start position:0% +looking at you know at energy of an + + + align:start position:0% +looking at you know at energy of an +elastic displacement or even not elastic + + align:start position:0% +elastic displacement or even not elastic + + + align:start position:0% +elastic displacement or even not elastic +um if I knew how these four atoms moved + + align:start position:0% +um if I knew how these four atoms moved + + + align:start position:0% +um if I knew how these four atoms moved +I could probably know something about + + align:start position:0% +I could probably know something about + + + align:start position:0% +I could probably know something about +how the other atoms move + + align:start position:0% +how the other atoms move + + + align:start position:0% +how the other atoms move +okay so I could interpolate say their + + align:start position:0% +okay so I could interpolate say their + + + align:start position:0% +okay so I could interpolate say their +displacement from the displacement of + + align:start position:0% +displacement from the displacement of + + + align:start position:0% +displacement from the displacement of +the corner atoms okay so what one thing + + align:start position:0% +the corner atoms okay so what one thing + + + align:start position:0% +the corner atoms okay so what one thing +you can do is say well if I know how + + align:start position:0% +you can do is say well if I know how + + + align:start position:0% +you can do is say well if I know how +these atoms move I assume that the + + align:start position:0% +these atoms move I assume that the + + + align:start position:0% +these atoms move I assume that the +energy of the atoms in between is + + align:start position:0% +energy of the atoms in between is + + + align:start position:0% +energy of the atoms in between is +essentially the same as an energy of a + + align:start position:0% +essentially the same as an energy of a + + + align:start position:0% +essentially the same as an energy of a +sort of macroscopic solid that I deform + + align:start position:0% +sort of macroscopic solid that I deform + + + align:start position:0% +sort of macroscopic solid that I deform +with that + + align:start position:0% +with that + + + align:start position:0% +with that +displacement uh you can do things in + + align:start position:0% +displacement uh you can do things in + + + align:start position:0% +displacement uh you can do things in +between you can actually sort of + + align:start position:0% +between you can actually sort of + + + align:start position:0% +between you can actually sort of +calculate the energy of that unit cell + + align:start position:0% +calculate the energy of that unit cell + + + align:start position:0% +calculate the energy of that unit cell +as it's displaced + + align:start position:0% +as it's displaced + + + align:start position:0% +as it's displaced +but the whole idea is that essentially + + align:start position:0% +but the whole idea is that essentially + + + align:start position:0% +but the whole idea is that essentially +you only have to keep you start keeping + + align:start position:0% +you only have to keep you start keeping + + + align:start position:0% +you only have to keep you start keeping +only track of a limited number of atoms + + align:start position:0% +only track of a limited number of atoms + + + align:start position:0% +only track of a limited number of atoms +and you can think of these as nodes so + + align:start position:0% +and you can think of these as nodes so + + + align:start position:0% +and you can think of these as nodes so +these are called nodal atoms and what + + align:start position:0% +these are called nodal atoms and what + + + align:start position:0% +these are called nodal atoms and what +happens to all the atoms you removed you + + align:start position:0% +happens to all the atoms you removed you + + + align:start position:0% +happens to all the atoms you removed you +essentially get by interpolation and + + align:start position:0% +essentially get by interpolation and + + + align:start position:0% +essentially get by interpolation and +once you're happy with using elasticity + + align:start position:0% +once you're happy with using elasticity + + + align:start position:0% +once you're happy with using elasticity +Theory then essentially you know what + + align:start position:0% +Theory then essentially you know what + + + align:start position:0% +Theory then essentially you know what +the energy of that Cube how that changes + + align:start position:0% +the energy of that Cube how that changes + + + align:start position:0% +the energy of that Cube how that changes +as you change the Four + + align:start position:0% +as you change the Four + + + align:start position:0% +as you change the Four +Corners um typically people use TR + + align:start position:0% +Corners um typically people use TR + + + align:start position:0% +Corners um typically people use TR +triangles because people will tend to + + align:start position:0% +triangles because people will tend to + + + align:start position:0% +triangles because people will tend to +use triangular meshes but I want to give + + align:start position:0% +use triangular meshes but I want to give + + + align:start position:0% +use triangular meshes but I want to give +the + + align:start position:0% +the + + + align:start position:0% +the +the the example with a square since it's + + align:start position:0% +the the example with a square since it's + + + align:start position:0% +the the example with a square since it's +a little + + align:start position:0% + + + + align:start position:0% + +simpler so this is essentially the idea + + align:start position:0% +simpler so this is essentially the idea + + + align:start position:0% +simpler so this is essentially the idea +of the Quasi Continuum method that you + + align:start position:0% +of the Quasi Continuum method that you + + + align:start position:0% +of the Quasi Continuum method that you +know let's say add + + align:start position:0% +know let's say add + + + align:start position:0% +know let's say add +here you have some perturbation + + align:start position:0% +here you have some perturbation + + + align:start position:0% +here you have some perturbation +something you want to study at there at + + align:start position:0% +something you want to study at there at + + + align:start position:0% +something you want to study at there at +the Mystic level as you go farther and + + align:start position:0% +the Mystic level as you go farther and + + + align:start position:0% +the Mystic level as you go farther and +farther away you want to cor grain more + + align:start position:0% +farther away you want to cor grain more + + + align:start position:0% +farther away you want to cor grain more +and more so essentially you want to keep + + align:start position:0% +and more so essentially you want to keep + + + align:start position:0% +and more so essentially you want to keep +less and less Nal atoms and get more and + + align:start position:0% +less and less Nal atoms and get more and + + + align:start position:0% +less and less Nal atoms and get more and +more information simply by interpolation + + align:start position:0% +more information simply by interpolation + + + align:start position:0% +more information simply by interpolation +so you could say this is Coors graining + + align:start position:0% +so you could say this is Coors graining + + + align:start position:0% +so you could say this is Coors graining +at the level of one out of four when + + align:start position:0% +at the level of one out of four when + + + align:start position:0% +at the level of one out of four when +you're here okay and then you have a few + + align:start position:0% +you're here okay and then you have a few + + + align:start position:0% +you're here okay and then you have a few +regions of that and then you co grain at + + align:start position:0% +regions of that and then you co grain at + + + align:start position:0% +regions of that and then you co grain at +a higher + + align:start position:0% +a higher + + + align:start position:0% +a higher +level okay so you keep say I should have + + align:start position:0% +level okay so you keep say I should have + + + align:start position:0% +level okay so you keep say I should have +removed so this should not be red this + + align:start position:0% +removed so this should not be red this + + + align:start position:0% +removed so this should not be red this +should be blue sorry so you only keep + + align:start position:0% +should be blue sorry so you only keep + + + align:start position:0% +should be blue sorry so you only keep +these four atoms and you sort of assume + + align:start position:0% +these four atoms and you sort of assume + + + align:start position:0% +these four atoms and you sort of assume +that that solid under goes a homogeneous + + align:start position:0% +that that solid under goes a homogeneous + + + align:start position:0% +that that solid under goes a homogeneous +deformation within that + + align:start position:0% +deformation within that + + + align:start position:0% +deformation within that +box um what you see is that you know + + align:start position:0% +box um what you see is that you know + + + align:start position:0% +box um what you see is that you know +somewhere in this limit you're going to + + align:start position:0% +somewhere in this limit you're going to + + + align:start position:0% +somewhere in this limit you're going to +end up with finite element approaches + + align:start position:0% +end up with finite element approaches + + + align:start position:0% +end up with finite element approaches +where essentially you do Continuum + + align:start position:0% +where essentially you do Continuum + + + align:start position:0% +where essentially you do Continuum +Theory and you essentially say that you + + align:start position:0% +Theory and you essentially say that you + + + align:start position:0% +Theory and you essentially say that you +know if I know some displacements of + + align:start position:0% +know if I know some displacements of + + + align:start position:0% +know if I know some displacements of +elements I know how that of the corner + + align:start position:0% +elements I know how that of the corner + + + align:start position:0% +elements I know how that of the corner +points the vertices of elements I know + + align:start position:0% +points the vertices of elements I know + + + align:start position:0% +points the vertices of elements I know +how that element deforms okay so what + + align:start position:0% +how that element deforms okay so what + + + align:start position:0% +how that element deforms okay so what +you have is essentially a sort of + + align:start position:0% +you have is essentially a sort of + + + align:start position:0% +you have is essentially a sort of +continuous transition here in cor + + align:start position:0% +continuous transition here in cor + + + align:start position:0% +continuous transition here in cor +graining from atomistic Behavior to a + + align:start position:0% +graining from atomistic Behavior to a + + + align:start position:0% +graining from atomistic Behavior to a +finite element approach and people have + + align:start position:0% +finite element approach and people have + + + align:start position:0% +finite element approach and people have +put that together and this is called a + + align:start position:0% +put that together and this is called a + + + align:start position:0% +put that together and this is called a +quasi Continuum approach you know this + + align:start position:0% +quasi Continuum approach you know this + + + align:start position:0% +quasi Continuum approach you know this +is sort of a pictorial version of it + + align:start position:0% +is sort of a pictorial version of it + + + align:start position:0% +is sort of a pictorial version of it +near some let's say this is some + + align:start position:0% +near some let's say this is some + + + align:start position:0% +near some let's say this is some +boundary where you do something uh you + + align:start position:0% +boundary where you do something uh you + + + align:start position:0% +boundary where you do something uh you +have very fine resolution you could say + + align:start position:0% +have very fine resolution you could say + + + align:start position:0% +have very fine resolution you could say +the nodes of your finite element M are + + align:start position:0% +the nodes of your finite element M are + + + align:start position:0% +the nodes of your finite element M are +the atoms and then as you go farther and + + align:start position:0% +the atoms and then as you go farther and + + + align:start position:0% +the atoms and then as you go farther and +farther away you cor graen more and more + + align:start position:0% +farther away you cor graen more and more + + + align:start position:0% +farther away you cor graen more and more +and you keep less and less + + align:start position:0% +and you keep less and less + + + align:start position:0% +and you keep less and less +information um I'll give you a reference + + align:start position:0% +information um I'll give you a reference + + + align:start position:0% +information um I'll give you a reference +at the end but um uh the people + + align:start position:0% +at the end but um uh the people + + + align:start position:0% +at the end but um uh the people +developed this were essentially a fairly + + align:start position:0% +developed this were essentially a fairly + + + align:start position:0% +developed this were essentially a fairly +small group of people shenoi tadmore and + + align:start position:0% +small group of people shenoi tadmore and + + + align:start position:0% +small group of people shenoi tadmore and +Rob Phillips and Michael Ortiz at + + align:start position:0% +Rob Phillips and Michael Ortiz at + + + align:start position:0% +Rob Phillips and Michael Ortiz at +Caltech and there's some excellent + + align:start position:0% +Caltech and there's some excellent + + + align:start position:0% +Caltech and there's some excellent +review papers about this if you like to + + align:start position:0% +review papers about this if you like to + + + align:start position:0% +review papers about this if you like to +read more about + + align:start position:0% + + + + align:start position:0% + +this it's it's now been fairly well + + align:start position:0% +this it's it's now been fairly well + + + align:start position:0% +this it's it's now been fairly well +implemented these kind of approaches + + align:start position:0% +implemented these kind of approaches + + + align:start position:0% +implemented these kind of approaches +mainly with + + align:start position:0% +mainly with + + + align:start position:0% +mainly with +empirical energy methods um people have + + align:start position:0% +empirical energy methods um people have + + + align:start position:0% +empirical energy methods um people have +tried to implement it with quantum + + align:start position:0% +tried to implement it with quantum + + + align:start position:0% +tried to implement it with quantum +mechanics and some people have actually + + align:start position:0% +mechanics and some people have actually + + + align:start position:0% +mechanics and some people have actually +done it but it's not all that effective + + align:start position:0% +done it but it's not all that effective + + + align:start position:0% +done it but it's not all that effective +really because of the the it's extremely + + align:start position:0% +really because of the the it's extremely + + + align:start position:0% +really because of the the it's extremely +hard to couple the atomistic region when + + align:start position:0% +hard to couple the atomistic region when + + + align:start position:0% +hard to couple the atomistic region when +you where you do quantum mechanics to a + + align:start position:0% +you where you do quantum mechanics to a + + + align:start position:0% +you where you do quantum mechanics to a +sort of more coar grained region um but + + align:start position:0% +sort of more coar grained region um but + + + align:start position:0% +sort of more coar grained region um but +with potentials and with things like + + align:start position:0% +with potentials and with things like + + + align:start position:0% +with potentials and with things like +embeded atom method people have coupled + + align:start position:0% +embeded atom method people have coupled + + + align:start position:0% +embeded atom method people have coupled +these things fairly well together uh + + align:start position:0% +these things fairly well together uh + + + align:start position:0% +these things fairly well together uh +this is for example a grain boundary uh + + align:start position:0% +this is for example a grain boundary uh + + + align:start position:0% +this is for example a grain boundary uh +sorry a crack impinging on a grain + + align:start position:0% +sorry a crack impinging on a grain + + + align:start position:0% +sorry a crack impinging on a grain +boundary see this is a symmetric grain + + align:start position:0% +boundary see this is a symmetric grain + + + align:start position:0% +boundary see this is a symmetric grain +boundary and you have the crack in the + + align:start position:0% +boundary and you have the crack in the + + + align:start position:0% +boundary and you have the crack in the +middle there it uh comes in hits the + + align:start position:0% +middle there it uh comes in hits the + + + align:start position:0% +middle there it uh comes in hits the +grain boundary and essentially deflects + + align:start position:0% +grain boundary and essentially deflects + + + align:start position:0% +grain boundary and essentially deflects +in the grain boundary okay so that's a + + align:start position:0% +in the grain boundary okay so that's a + + + align:start position:0% +in the grain boundary okay so that's a +simulation done with quasi + + align:start position:0% +simulation done with quasi + + + align:start position:0% +simulation done with quasi +Continuum you know if you want to think + + align:start position:0% +Continuum you know if you want to think + + + align:start position:0% +Continuum you know if you want to think +about it what it really does for you + + align:start position:0% +about it what it really does for you + + + align:start position:0% +about it what it really does for you +quasi Continuum is that it's a way of + + align:start position:0% +quasi Continuum is that it's a way of + + + align:start position:0% +quasi Continuum is that it's a way of +getting the boundary conditions right on + + align:start position:0% +getting the boundary conditions right on + + + align:start position:0% +getting the boundary conditions right on +your atomistic simulation + + align:start position:0% +your atomistic simulation + + + align:start position:0% +your atomistic simulation +uh by slowly integrating essentially + + align:start position:0% +uh by slowly integrating essentially + + + align:start position:0% +uh by slowly integrating essentially +with a Continuum Theory um you first of + + align:start position:0% +with a Continuum Theory um you first of + + + align:start position:0% +with a Continuum Theory um you first of +all have adaptive your your um uh + + align:start position:0% +all have adaptive your your um uh + + + align:start position:0% +all have adaptive your your um uh +boundary conditions on your atomistic + + align:start position:0% +boundary conditions on your atomistic + + + align:start position:0% +boundary conditions on your atomistic +simulation change during the simulation + + align:start position:0% +simulation change during the simulation + + + align:start position:0% +simulation change during the simulation +and because you have a better embedding + + align:start position:0% +and because you have a better embedding + + + align:start position:0% +and because you have a better embedding +Theory you have a better Continuum + + align:start position:0% +Theory you have a better Continuum + + + align:start position:0% +Theory you have a better Continuum +Theory um they're sort of more + + align:start position:0% +Theory um they're sort of more + + + align:start position:0% +Theory um they're sort of more +appropriate and especially in mechanical + + align:start position:0% +appropriate and especially in mechanical + + + align:start position:0% +appropriate and especially in mechanical +problems that is very important uh to + + align:start position:0% +problems that is very important uh to + + + align:start position:0% +problems that is very important uh to +have the right elastic boundary + + align:start position:0% +have the right elastic boundary + + + align:start position:0% +have the right elastic boundary +conditions + + align:start position:0% + + + + align:start position:0% + +um so let me sort of position this for + + align:start position:0% +um so let me sort of position this for + + + align:start position:0% +um so let me sort of position this for +you uh to show you where we have the + + align:start position:0% +you uh to show you where we have the + + + align:start position:0% +you uh to show you where we have the +solution and where we still have + + align:start position:0% +solution and where we still have + + + align:start position:0% +solution and where we still have +significant problems you know I would + + align:start position:0% +significant problems you know I would + + + align:start position:0% +significant problems you know I would +essentially say when we work purely at a + + align:start position:0% +essentially say when we work purely at a + + + align:start position:0% +essentially say when we work purely at a +microscopic scale we have most things + + align:start position:0% +microscopic scale we have most things + + + align:start position:0% +microscopic scale we have most things +under control um you know we know well + + align:start position:0% +under control um you know we know well + + + align:start position:0% +under control um you know we know well +how to deal with the energetics we know + + align:start position:0% +how to deal with the energetics we know + + + align:start position:0% +how to deal with the energetics we know +fairly well how to deal with the + + align:start position:0% +fairly well how to deal with the + + + align:start position:0% +fairly well how to deal with the +Dynamics because for pretty much + + align:start position:0% +Dynamics because for pretty much + + + align:start position:0% +Dynamics because for pretty much +everything except things like hydrogen + + align:start position:0% +everything except things like hydrogen + + + align:start position:0% +everything except things like hydrogen +you can use Newtonian Dynamics even on + + align:start position:0% +you can use Newtonian Dynamics even on + + + align:start position:0% +you can use Newtonian Dynamics even on +the atomistic scale You could argue we + + align:start position:0% +the atomistic scale You could argue we + + + align:start position:0% +the atomistic scale You could argue we +don't really know how to deal well with + + align:start position:0% +don't really know how to deal well with + + + align:start position:0% +don't really know how to deal well with +electron Dynamics but that's another + + align:start position:0% +electron Dynamics but that's another + + + align:start position:0% +electron Dynamics but that's another +problem if you're willing to go all the + + align:start position:0% +problem if you're willing to go all the + + + align:start position:0% +problem if you're willing to go all the +way to the Continuum scale we also know + + align:start position:0% +way to the Continuum scale we also know + + + align:start position:0% +way to the Continuum scale we also know +the equations that describe matter it's + + align:start position:0% +the equations that describe matter it's + + + align:start position:0% +the equations that describe matter it's +essentially thermodynamics and + + align:start position:0% +essentially thermodynamics and + + + align:start position:0% +essentially thermodynamics and +elasticity you know and you could think + + align:start position:0% +elasticity you know and you could think + + + align:start position:0% +elasticity you know and you could think +of thermodynamics as the integrator of + + align:start position:0% +of thermodynamics as the integrator of + + + align:start position:0% +of thermodynamics as the integrator of +those um it's when we live at this + + align:start position:0% +those um it's when we live at this + + + align:start position:0% +those um it's when we live at this +inhomogeneous Co grain scale that we're + + align:start position:0% +inhomogeneous Co grain scale that we're + + + align:start position:0% +inhomogeneous Co grain scale that we're +really in trouble and I'll give you an + + align:start position:0% +really in trouble and I'll give you an + + + align:start position:0% +really in trouble and I'll give you an +example uh think of + + align:start position:0% +example uh think of + + + align:start position:0% +example uh think of +temperature in Continuum Theory + + align:start position:0% +temperature in Continuum Theory + + + align:start position:0% +temperature in Continuum Theory +temperature is a + + align:start position:0% +temperature is a + + + align:start position:0% +temperature is a +field um in a microscopic simulation + + align:start position:0% +field um in a microscopic simulation + + + align:start position:0% +field um in a microscopic simulation +it's kinetic energy of the + + align:start position:0% +it's kinetic energy of the + + + align:start position:0% +it's kinetic energy of the +atoms you can already see a problem of + + align:start position:0% +atoms you can already see a problem of + + + align:start position:0% +atoms you can already see a problem of +appear + + align:start position:0% +appear + + + align:start position:0% +appear +essentially as you inhomogeneously cor + + align:start position:0% +essentially as you inhomogeneously cor + + + align:start position:0% +essentially as you inhomogeneously cor +grain around an atomistic region that + + align:start position:0% +grain around an atomistic region that + + + align:start position:0% +grain around an atomistic region that +temperature has to evolve from being you + + align:start position:0% +temperature has to evolve from being you + + + align:start position:0% +temperature has to evolve from being you +know the kinetic energy of motion to a + + align:start position:0% +know the kinetic energy of motion to a + + + align:start position:0% +know the kinetic energy of motion to a +field and it's it's non tricky to know + + align:start position:0% +field and it's it's non tricky to know + + + align:start position:0% +field and it's it's non tricky to know +what you do in between I mean I know how + + align:start position:0% +what you do in between I mean I know how + + + align:start position:0% +what you do in between I mean I know how +to deal with temperature as a field I + + align:start position:0% +to deal with temperature as a field I + + + align:start position:0% +to deal with temperature as a field I +know how to deal with this kinetic + + align:start position:0% +know how to deal with this kinetic + + + align:start position:0% +know how to deal with this kinetic +energy but what is it in between what is + + align:start position:0% +energy but what is it in between what is + + + align:start position:0% +energy but what is it in between what is +it when you're say a factor of 10 cor + + align:start position:0% +it when you're say a factor of 10 cor + + + align:start position:0% +it when you're say a factor of 10 cor +grain so you've removed every 10th atom + + align:start position:0% +grain so you've removed every 10th atom + + + align:start position:0% +grain so you've removed every 10th atom +and I'm going to go a little deeper in + + align:start position:0% +and I'm going to go a little deeper in + + + align:start position:0% +and I'm going to go a little deeper in +some of these things but those are some + + align:start position:0% +some of these things but those are some + + + align:start position:0% +some of these things but those are some +of the problems we also don't know what + + align:start position:0% +of the problems we also don't know what + + + align:start position:0% +of the problems we also don't know what +the Dynamics here is at this + + align:start position:0% +the Dynamics here is at this + + + align:start position:0% +the Dynamics here is at this +scale um because think of you know how + + align:start position:0% +scale um because think of you know how + + + align:start position:0% +scale um because think of you know how +do you dissipate energy how do you + + align:start position:0% +do you dissipate energy how do you + + + align:start position:0% +do you dissipate energy how do you +dissipate energy in a microscopic + + align:start position:0% +dissipate energy in a microscopic + + + align:start position:0% +dissipate energy in a microscopic +system okay you dissipate it essentially + + align:start position:0% +system okay you dissipate it essentially + + + align:start position:0% +system okay you dissipate it essentially +by non-harmonic + + align:start position:0% +by non-harmonic + + + align:start position:0% +by non-harmonic +vibrations okay that's how you dissipate + + align:start position:0% +vibrations okay that's how you dissipate + + + align:start position:0% +vibrations okay that's how you dissipate +energy how do you dissipate it here + + align:start position:0% +energy how do you dissipate it here + + + align:start position:0% +energy how do you dissipate it here +actually you don't unless you put it in + + align:start position:0% +actually you don't unless you put it in + + + align:start position:0% +actually you don't unless you put it in +explicitly okay you in a perfectly + + align:start position:0% +explicitly okay you in a perfectly + + + align:start position:0% +explicitly okay you in a perfectly +elasticity Theory you you know you don't + + align:start position:0% +elasticity Theory you you know you don't + + + align:start position:0% +elasticity Theory you you know you don't +have + + align:start position:0% +have + + + align:start position:0% +have +dissipation so again energy dissipation + + align:start position:0% +dissipation so again energy dissipation + + + align:start position:0% +dissipation so again energy dissipation +is a big deal in inhomogeneously cor + + align:start position:0% +is a big deal in inhomogeneously cor + + + align:start position:0% +is a big deal in inhomogeneously cor +grain systems uh because the mechanism + + align:start position:0% +grain systems uh because the mechanism + + + align:start position:0% +grain systems uh because the mechanism +by which it happens at the atomistic and + + align:start position:0% +by which it happens at the atomistic and + + + align:start position:0% +by which it happens at the atomistic and +at the Continuum scale is + + align:start position:0% + + + + align:start position:0% + +different um so quasi Continuum + + align:start position:0% +different um so quasi Continuum + + + align:start position:0% +different um so quasi Continuum +approaches have been extremely + + align:start position:0% +approaches have been extremely + + + align:start position:0% +approaches have been extremely +successful for elastic static properties + + align:start position:0% +successful for elastic static properties + + + align:start position:0% +successful for elastic static properties +and even nonlinear elastic problems um + + align:start position:0% +and even nonlinear elastic problems um + + + align:start position:0% +and even nonlinear elastic problems um +it's when people try to put temperature + + align:start position:0% +it's when people try to put temperature + + + align:start position:0% +it's when people try to put temperature +and Dynamics in that life gets a lot + + align:start position:0% +and Dynamics in that life gets a lot + + + align:start position:0% +and Dynamics in that life gets a lot +more complicated so there are + + align:start position:0% +more complicated so there are + + + align:start position:0% +more complicated so there are +essentially two approaches that have + + align:start position:0% +essentially two approaches that have + + + align:start position:0% +essentially two approaches that have +been suggested tried and both you know + + align:start position:0% +been suggested tried and both you know + + + align:start position:0% +been suggested tried and both you know +sort of seem reasonable but have + + align:start position:0% +sort of seem reasonable but have + + + align:start position:0% +sort of seem reasonable but have +significant failures um one is to Simply + + align:start position:0% +significant failures um one is to Simply + + + align:start position:0% +significant failures um one is to Simply +let's say you how you do how would you + + align:start position:0% +let's say you how you do how would you + + + align:start position:0% +let's say you how you do how would you +do molecular Dynamics on a CO grain + + align:start position:0% +do molecular Dynamics on a CO grain + + + align:start position:0% +do molecular Dynamics on a CO grain +system like this well you remember + + align:start position:0% +system like this well you remember + + + align:start position:0% +system like this well you remember +you've removed these + + align:start position:0% +you've removed these + + + align:start position:0% +you've removed these +atoms uh you could lump their Mass into + + align:start position:0% +atoms uh you could lump their Mass into + + + align:start position:0% +atoms uh you could lump their Mass into +the + + align:start position:0% +the + + + align:start position:0% +the +nodes so essentially the nodes of your + + align:start position:0% +nodes so essentially the nodes of your + + + align:start position:0% +nodes so essentially the nodes of your +mesh now become heavier and then you do + + align:start position:0% +mesh now become heavier and then you do + + + align:start position:0% +mesh now become heavier and then you do +MD on those okay the problem with that + + align:start position:0% +MD on those okay the problem with that + + + align:start position:0% +MD on those okay the problem with that +is that as you cor grade more and more + + align:start position:0% +is that as you cor grade more and more + + + align:start position:0% +is that as you cor grade more and more +you get the heavier and heavier notes + + align:start position:0% +you get the heavier and heavier notes + + + align:start position:0% +you get the heavier and heavier notes +and after a while they don't move + + align:start position:0% +and after a while they don't move + + + align:start position:0% +and after a while they don't move +anymore because if they have the same + + align:start position:0% +anymore because if they have the same + + + align:start position:0% +anymore because if they have the same +temperature okay mv^ s average over two + + align:start position:0% +temperature okay mv^ s average over two + + + align:start position:0% +temperature okay mv^ s average over two +is the temperature so if the same + + align:start position:0% +is the temperature so if the same + + + align:start position:0% +is the temperature so if the same +temperature the V becomes very + + align:start position:0% +temperature the V becomes very + + + align:start position:0% +temperature the V becomes very +small um the other one is a sort of uh + + align:start position:0% +small um the other one is a sort of uh + + + align:start position:0% +small um the other one is a sort of uh +often used approach to use um static + + align:start position:0% +often used approach to use um static + + + align:start position:0% +often used approach to use um static +optimizations but rather than say get + + align:start position:0% +optimizations but rather than say get + + + align:start position:0% +optimizations but rather than say get +all the the positions of these + + align:start position:0% +all the the positions of these + + + align:start position:0% +all the the positions of these +atoms rather than get them from the + + align:start position:0% +atoms rather than get them from the + + + align:start position:0% +atoms rather than get them from the +energy get them from minimizing the free + + align:start position:0% +energy get them from minimizing the free + + + align:start position:0% +energy get them from minimizing the free +energy so use say the force would be now + + align:start position:0% +energy so use say the force would be now + + + align:start position:0% +energy so use say the force would be now +the gradient of something like the free + + align:start position:0% +the gradient of something like the free + + + align:start position:0% +the gradient of something like the free +energy rather than the gradient of the + + align:start position:0% +energy rather than the gradient of the + + + align:start position:0% +energy rather than the gradient of the +energy so you have some amount of + + align:start position:0% +energy so you have some amount of + + + align:start position:0% +energy so you have some amount of +temperature effects in there then um but + + align:start position:0% +temperature effects in there then um but + + + align:start position:0% +temperature effects in there then um but +you don't truly have + + align:start position:0% + + + + align:start position:0% + +Dynamics so one thing this would do for + + align:start position:0% +Dynamics so one thing this would do for + + + align:start position:0% +Dynamics so one thing this would do for +you for example is you'd get the right + + align:start position:0% +you for example is you'd get the right + + + align:start position:0% +you for example is you'd get the right +Bond Lings and lce parameters + + align:start position:0% + + + + align:start position:0% + +okay uh I want to show you some other + + align:start position:0% +okay uh I want to show you some other + + + align:start position:0% +okay uh I want to show you some other +ideas that have been out there uh this + + align:start position:0% +ideas that have been out there uh this + + + align:start position:0% +ideas that have been out there uh this +is one that I've worked on for a short + + align:start position:0% +is one that I've worked on for a short + + + align:start position:0% +is one that I've worked on for a short +while um but the generic idea has really + + align:start position:0% +while um but the generic idea has really + + + align:start position:0% +while um but the generic idea has really +been out there in the community a long + + align:start position:0% +been out there in the community a long + + + align:start position:0% +been out there in the community a long +time and it's very similar to what we've + + align:start position:0% +time and it's very similar to what we've + + + align:start position:0% +time and it's very similar to what we've +done in the cor graining of time um the + + align:start position:0% +done in the cor graining of time um the + + + align:start position:0% +done in the cor graining of time um the +idea is essentially you know think of + + align:start position:0% +idea is essentially you know think of + + + align:start position:0% +idea is essentially you know think of +three atoms on a chain one two three + + align:start position:0% +three atoms on a chain one two three + + + align:start position:0% +three atoms on a chain one two three +there um what if you want to remove atom + + align:start position:0% +there um what if you want to remove atom + + + align:start position:0% +there um what if you want to remove atom +two and So Co grain and only keep one + + align:start position:0% +two and So Co grain and only keep one + + + align:start position:0% +two and So Co grain and only keep one +and three as the nodes the question + + align:start position:0% +and three as the nodes the question + + + align:start position:0% +and three as the nodes the question +really is what should your + + align:start position:0% +really is what should your + + + align:start position:0% +really is what should your +potential let's say you do this with + + align:start position:0% +potential let's say you do this with + + + align:start position:0% +potential let's say you do this with +potential don't even worry about quantum + + align:start position:0% +potential don't even worry about quantum + + + align:start position:0% +potential don't even worry about quantum +mechanics what should your potential + + align:start position:0% +mechanics what should your potential + + + align:start position:0% +mechanics what should your potential +between one and + + align:start position:0% +between one and + + + align:start position:0% +between one and +3B um so that they behave the same way + + align:start position:0% +3B um so that they behave the same way + + + align:start position:0% +3B um so that they behave the same way +as if two were there so you're going to + + align:start position:0% +as if two were there so you're going to + + + align:start position:0% +as if two were there so you're going to +take two out but you want to set up a + + align:start position:0% +take two out but you want to set up a + + + align:start position:0% +take two out but you want to set up a +potential between one and three that + + align:start position:0% +potential between one and three that + + + align:start position:0% +potential between one and three that +acts like if two were there well you + + align:start position:0% +acts like if two were there well you + + + align:start position:0% +acts like if two were there well you +could can get the solution again from + + align:start position:0% +could can get the solution again from + + + align:start position:0% +could can get the solution again from +thermodynamics essentially + + align:start position:0% +thermodynamics essentially + + + align:start position:0% +thermodynamics essentially +requiring that the partition function + + align:start position:0% +requiring that the partition function + + + align:start position:0% +requiring that the partition function +for the motion of 1 and three is the + + align:start position:0% +for the motion of 1 and three is the + + + align:start position:0% +for the motion of 1 and three is the +same with or without two there and + + align:start position:0% +same with or without two there and + + + align:start position:0% +same with or without two there and +that's essentially what's written out + + align:start position:0% +that's essentially what's written out + + + align:start position:0% +that's essentially what's written out +out here if you think of uh q's and PS + + align:start position:0% +out here if you think of uh q's and PS + + + align:start position:0% +out here if you think of uh q's and PS +for the coordinates remember Q's are + + align:start position:0% +for the coordinates remember Q's are + + + align:start position:0% +for the coordinates remember Q's are +spatial coordinates PS are um velocities + + align:start position:0% +spatial coordinates PS are um velocities + + + align:start position:0% +spatial coordinates PS are um velocities +essentially they're moment um + + align:start position:0% +essentially they're moment um + + + align:start position:0% +essentially they're moment um +essentially what you're saying is that + + align:start position:0% +essentially what you're saying is that + + + align:start position:0% +essentially what you're saying is that +the free energy of the hamiltonian with + + align:start position:0% +the free energy of the hamiltonian with + + + align:start position:0% +the free energy of the hamiltonian with +only q1 and Q3 so now you keep only the + + align:start position:0% +only q1 and Q3 so now you keep only the + + + align:start position:0% +only q1 and Q3 so now you keep only the +positions of one and three is obtained + + align:start position:0% +positions of one and three is obtained + + + align:start position:0% +positions of one and three is obtained +by integrating away the coordinates of + + align:start position:0% +by integrating away the coordinates of + + + align:start position:0% +by integrating away the coordinates of +two so you integrate over the position + + align:start position:0% +two so you integrate over the position + + + align:start position:0% +two so you integrate over the position +and over the momentum of Two And if the + + align:start position:0% +and over the momentum of Two And if the + + + align:start position:0% +and over the momentum of Two And if the +Motions are classical then the + + align:start position:0% +Motions are classical then the + + + align:start position:0% +Motions are classical then the +integration over the momentum is Trivial + + align:start position:0% +integration over the momentum is Trivial + + + align:start position:0% +integration over the momentum is Trivial +you know you always get the same factors + + align:start position:0% +you know you always get the same factors + + + align:start position:0% +you know you always get the same factors +from the momentum so it's really the + + align:start position:0% +from the momentum so it's really the + + + align:start position:0% +from the momentum so it's really the +integration over um the coordinates and + + align:start position:0% +integration over um the coordinates and + + + align:start position:0% +integration over um the coordinates and +so you know if you integrate this away + + align:start position:0% +so you know if you integrate this away + + + align:start position:0% +so you know if you integrate this away +then formally this integral has no Q2 + + align:start position:0% +then formally this integral has no Q2 + + + align:start position:0% +then formally this integral has no Q2 +dependence by definition you've + + align:start position:0% +dependence by definition you've + + + align:start position:0% +dependence by definition you've +essentially integrated over all possible + + align:start position:0% +essentially integrated over all possible + + + align:start position:0% +essentially integrated over all possible +displacements of two to get the + + align:start position:0% +displacements of two to get the + + + align:start position:0% +displacements of two to get the +interaction between one and + + align:start position:0% +interaction between one and + + + align:start position:0% +interaction between one and +three um and so that then defines a + + align:start position:0% +three um and so that then defines a + + + align:start position:0% +three um and so that then defines a +potential just between one and three + + align:start position:0% +potential just between one and three + + + align:start position:0% +potential just between one and three +okay now there's all kinds of practical + + align:start position:0% +okay now there's all kinds of practical + + + align:start position:0% +okay now there's all kinds of practical +issues you can really only do this + + align:start position:0% +issues you can really only do this + + + align:start position:0% +issues you can really only do this +effectively if you have um interactions + + align:start position:0% +effectively if you have um interactions + + + align:start position:0% +effectively if you have um interactions +that are spatially limited because + + align:start position:0% +that are spatially limited because + + + align:start position:0% +that are spatially limited because +otherwise you really don't know over + + align:start position:0% +otherwise you really don't know over + + + align:start position:0% +otherwise you really don't know over +what you all have to integrate so this + + align:start position:0% +what you all have to integrate so this + + + align:start position:0% +what you all have to integrate so this +works great with pair + + align:start position:0% +works great with pair + + + align:start position:0% +works great with pair +potential okay so you know what does + + align:start position:0% +potential okay so you know what does + + + align:start position:0% +potential okay so you know what does +this physically mean it really means + + align:start position:0% +this physically mean it really means + + + align:start position:0% +this physically mean it really means +that um if you say displace atom three + + align:start position:0% +that um if you say displace atom three + + + align:start position:0% +that um if you say displace atom three +and you look at the force that it + + align:start position:0% +and you look at the force that it + + + align:start position:0% +and you look at the force that it +produces on atom one that you're looking + + align:start position:0% +produces on atom one that you're looking + + + align:start position:0% +produces on atom one that you're looking +at the kind of screening by atom 2 is + + align:start position:0% +at the kind of screening by atom 2 is + + + align:start position:0% +at the kind of screening by atom 2 is +included now you know in the real system + + align:start position:0% +included now you know in the real system + + + align:start position:0% +included now you know in the real system +atom 2 would sort of maybe screen that + + align:start position:0% +atom 2 would sort of maybe screen that + + + align:start position:0% +atom 2 would sort of maybe screen that +displacement away somewhat and that's + + align:start position:0% +displacement away somewhat and that's + + + align:start position:0% +displacement away somewhat and that's +not included and people have done this + + align:start position:0% +not included and people have done this + + + align:start position:0% +not included and people have done this +before like looking at interactions of + + align:start position:0% +before like looking at interactions of + + + align:start position:0% +before like looking at interactions of +you know when you look at interactions + + align:start position:0% +you know when you look at interactions + + + align:start position:0% +you know when you look at interactions +of ions in + + align:start position:0% +of ions in + + + align:start position:0% +of ions in +fluids okay the way to look at the + + align:start position:0% +fluids okay the way to look at the + + + align:start position:0% +fluids okay the way to look at the +interaction between two ions is by + + align:start position:0% +interaction between two ions is by + + + align:start position:0% +interaction between two ions is by +integrating over the possible + + align:start position:0% +integrating over the possible + + + align:start position:0% +integrating over the possible +displacements of all the other ones in + + align:start position:0% +displacements of all the other ones in + + + align:start position:0% +displacements of all the other ones in +between and that's how you end up with + + align:start position:0% +between and that's how you end up with + + + align:start position:0% +between and that's how you end up with +screening so this is sort of the + + align:start position:0% +screening so this is sort of the + + + align:start position:0% +screening so this is sort of the +screening equivalent um in displacement + + align:start position:0% + + + + align:start position:0% + +Fields um and what you geta is very much + + align:start position:0% +Fields um and what you geta is very much + + + align:start position:0% +Fields um and what you geta is very much +what you'd expected uh this is the + + align:start position:0% +what you'd expected uh this is the + + + align:start position:0% +what you'd expected uh this is the +potentials for different levels of Co + + align:start position:0% +potentials for different levels of Co + + + align:start position:0% +potentials for different levels of Co +grading in normalized distances so if + + align:start position:0% +grading in normalized distances so if + + + align:start position:0% +grading in normalized distances so if +the the length of the the the bond + + align:start position:0% +the the length of the the the bond + + + align:start position:0% +the the length of the the the bond +length is in is in units of one so this + + align:start position:0% +length is in is in units of one so this + + + align:start position:0% +length is in is in units of one so this +would be the normal potential if you cor + + align:start position:0% +would be the normal potential if you cor + + + align:start position:0% +would be the normal potential if you cor +green one level so you remove every + + align:start position:0% +green one level so you remove every + + + align:start position:0% +green one level so you remove every +other atom you actually end up with a + + align:start position:0% +other atom you actually end up with a + + + align:start position:0% +other atom you actually end up with a +potential that's twice the bond length + + align:start position:0% +potential that's twice the bond length + + + align:start position:0% +potential that's twice the bond length +because you remember you now you have + + align:start position:0% +because you remember you now you have + + + align:start position:0% +because you remember you now you have +one two atom one two three you've + + align:start position:0% +one two atom one two three you've + + + align:start position:0% +one two atom one two three you've +removed two so the equilibrium distance + + align:start position:0% +removed two so the equilibrium distance + + + align:start position:0% +removed two so the equilibrium distance +between one and three is about two times + + align:start position:0% +between one and three is about two times + + + align:start position:0% +between one and three is about two times +the bond + + align:start position:0% +the bond + + + align:start position:0% +the bond +length and you keep on Co graining and + + align:start position:0% +length and you keep on Co graining and + + + align:start position:0% +length and you keep on Co graining and +you end up with a potential that's four + + align:start position:0% +you end up with a potential that's four + + + align:start position:0% +you end up with a potential that's four +times the bond length 8 times the bond + + align:start position:0% +times the bond length 8 times the bond + + + align:start position:0% +times the bond length 8 times the bond +Ling okay + + align:start position:0% + + + + align:start position:0% + +um it turns out that spatial Co graining + + align:start position:0% +um it turns out that spatial Co graining + + + align:start position:0% +um it turns out that spatial Co graining +um always uh tends to ca some kind of + + align:start position:0% +um always uh tends to ca some kind of + + + align:start position:0% +um always uh tends to ca some kind of +time cor that's a much more difficult + + align:start position:0% +time cor that's a much more difficult + + + align:start position:0% +time cor that's a much more difficult +issue that I want to say much um you + + align:start position:0% +issue that I want to say much um you + + + align:start position:0% +issue that I want to say much um you +know in 1D it's easy to remove atoms uh + + align:start position:0% +know in 1D it's easy to remove atoms uh + + + align:start position:0% +know in 1D it's easy to remove atoms uh +and add up so when you remove atom two + + align:start position:0% +and add up so when you remove atom two + + + align:start position:0% +and add up so when you remove atom two +that's between one and three you + + align:start position:0% +that's between one and three you + + + align:start position:0% +that's between one and three you +essentially that defines the potential + + align:start position:0% +essentially that defines the potential + + + align:start position:0% +essentially that defines the potential +between and three + + align:start position:0% +between and three + + + align:start position:0% +between and three +in 2D it's a little harder how you + + align:start position:0% +in 2D it's a little harder how you + + + align:start position:0% +in 2D it's a little harder how you +partition bonds but you can do all kinds + + align:start position:0% +partition bonds but you can do all kinds + + + align:start position:0% +partition bonds but you can do all kinds +of bond moving approximations this is a + + align:start position:0% +of bond moving approximations this is a + + + align:start position:0% +of bond moving approximations this is a +simple one in a triangular lce where if + + align:start position:0% +simple one in a triangular lce where if + + + align:start position:0% +simple one in a triangular lce where if +you um if you have a + + align:start position:0% +you um if you have a + + + align:start position:0% +you um if you have a +triangle you essentially want to remove + + align:start position:0% +triangle you essentially want to remove + + + align:start position:0% +triangle you essentially want to remove +these guys + + align:start position:0% +these guys + + + align:start position:0% +these guys +here and so you can Define some scheme + + align:start position:0% +here and so you can Define some scheme + + + align:start position:0% +here and so you can Define some scheme +by which you sort of collapse + + align:start position:0% + + + + align:start position:0% + +um collapse the bonds onto these side es + + align:start position:0% +um collapse the bonds onto these side es + + + align:start position:0% +um collapse the bonds onto these side es +um you can also Define other schemes so + + align:start position:0% +um you can also Define other schemes so + + + align:start position:0% +um you can also Define other schemes so +here's an example of an inhomogeneously + + align:start position:0% +here's an example of an inhomogeneously + + + align:start position:0% +here's an example of an inhomogeneously +coar grain system in 2D where in this + + align:start position:0% +coar grain system in 2D where in this + + + align:start position:0% +coar grain system in 2D where in this +case it's fine at the edges and it's + + align:start position:0% +case it's fine at the edges and it's + + + align:start position:0% +case it's fine at the edges and it's +coarse in the middle + + align:start position:0% + + + + align:start position:0% + +um okay um there are essentially two + + align:start position:0% +um okay um there are essentially two + + + align:start position:0% +um okay um there are essentially two +major problems with almost any Co + + align:start position:0% +major problems with almost any Co + + + align:start position:0% +major problems with almost any Co +graining scheme and the first one is the + + align:start position:0% +graining scheme and the first one is the + + + align:start position:0% +graining scheme and the first one is the +worst + + align:start position:0% + + + + align:start position:0% + +is that um whenever you go from a you + + align:start position:0% +is that um whenever you go from a you + + + align:start position:0% +is that um whenever you go from a you +know let's say you're at the Mystic out + + align:start position:0% +know let's say you're at the Mystic out + + + align:start position:0% +know let's say you're at the Mystic out +here here you've Co grained level four + + align:start position:0% +here here you've Co grained level four + + + align:start position:0% +here here you've Co grained level four +Co grain another factor of four um you + + align:start position:0% +Co grain another factor of four um you + + + align:start position:0% +Co grain another factor of four um you +cannot sustain short wavelength phonons + + align:start position:0% +cannot sustain short wavelength phonons + + + align:start position:0% +cannot sustain short wavelength phonons +in the course regions you know let's say + + align:start position:0% +in the course regions you know let's say + + + align:start position:0% +in the course regions you know let's say +you have a phonon come in here that's + + align:start position:0% +you have a phonon come in here that's + + + align:start position:0% +you have a phonon come in here that's +um say has a wavelength uh like this + + align:start position:0% + + + + align:start position:0% + +uh since here you only have these + + align:start position:0% + + + + align:start position:0% + +nodes this is essentially the minimum + + align:start position:0% +nodes this is essentially the minimum + + + align:start position:0% +nodes this is essentially the minimum +wavelength you can have okay because the + + align:start position:0% +wavelength you can have okay because the + + + align:start position:0% +wavelength you can have okay because the +minimum bound distance so every time at + + align:start position:0% +minimum bound distance so every time at + + + align:start position:0% +minimum bound distance so every time at +every + + align:start position:0% +every + + + align:start position:0% +every +interface between a fine region and a + + align:start position:0% +interface between a fine region and a + + + align:start position:0% +interface between a fine region and a +corser region what happens is that + + align:start position:0% +corser region what happens is that + + + align:start position:0% +corser region what happens is that +there's a series of phonons the one with + + align:start position:0% +there's a series of phonons the one with + + + align:start position:0% +there's a series of phonons the one with +that have a wavelength that's too short + + align:start position:0% +that have a wavelength that's too short + + + align:start position:0% +that have a wavelength that's too short +get reflected back because they cannot + + align:start position:0% +get reflected back because they cannot + + + align:start position:0% +get reflected back because they cannot +not um go into the cors of + + align:start position:0% +not um go into the cors of + + + align:start position:0% +not um go into the cors of +region and ultimately you hit the + + align:start position:0% +region and ultimately you hit the + + + align:start position:0% +region and ultimately you hit the +Continuum region and you can't have any + + align:start position:0% +Continuum region and you can't have any + + + align:start position:0% +Continuum region and you can't have any +phons okay because there they should all + + align:start position:0% +phons okay because there they should all + + + align:start position:0% +phons okay because there they should all +be dissipated as + + align:start position:0% +be dissipated as + + + align:start position:0% +be dissipated as +temperature um so what does that cause + + align:start position:0% +temperature um so what does that cause + + + align:start position:0% +temperature um so what does that cause +well um if you look at dynamical + + align:start position:0% +well um if you look at dynamical + + + align:start position:0% +well um if you look at dynamical +processes um let's say you have a fine + + align:start position:0% +processes um let's say you have a fine + + + align:start position:0% +processes um let's say you have a fine +region in which you have some reaction + + align:start position:0% +region in which you have some reaction + + + align:start position:0% +region in which you have some reaction +that dissipates energy or that creates + + align:start position:0% +that dissipates energy or that creates + + + align:start position:0% +that dissipates energy or that creates +energy the way that that energy has to + + align:start position:0% +energy the way that that energy has to + + + align:start position:0% +energy the way that that energy has to +get out is by phon transmission okay you + + align:start position:0% +get out is by phon transmission okay you + + + align:start position:0% +get out is by phon transmission okay you +have to send lce vibrations out which + + align:start position:0% +have to send lce vibrations out which + + + align:start position:0% +have to send lce vibrations out which +through their anharmonicity have to get + + align:start position:0% +through their anharmonicity have to get + + + align:start position:0% +through their anharmonicity have to get +dissipated + + align:start position:0% +dissipated + + + align:start position:0% +dissipated +somewhere and so anytime you block phons + + align:start position:0% +somewhere and so anytime you block phons + + + align:start position:0% +somewhere and so anytime you block phons +you're essentially reducing the thermal + + align:start position:0% +you're essentially reducing the thermal + + + align:start position:0% +you're essentially reducing the thermal +conductivity of the system okay so this + + align:start position:0% +conductivity of the system okay so this + + + align:start position:0% +conductivity of the system okay so this +Co graining gives you lower thermal + + align:start position:0% +Co graining gives you lower thermal + + + align:start position:0% +Co graining gives you lower thermal +conductivity and I'll show you some + + align:start position:0% +conductivity and I'll show you some + + + align:start position:0% +conductivity and I'll show you some +examples in a second but you know it + + align:start position:0% +examples in a second but you know it + + + align:start position:0% +examples in a second but you know it +does worse things it's essentially + + align:start position:0% +does worse things it's essentially + + + align:start position:0% +does worse things it's essentially +elastically confining also your system + + align:start position:0% +elastically confining also your system + + + align:start position:0% +elastically confining also your system +somewhat but only in a dynamic sense so + + align:start position:0% +somewhat but only in a dynamic sense so + + + align:start position:0% +somewhat but only in a dynamic sense so +it's like you're having for + + align:start position:0% +it's like you're having for + + + align:start position:0% +it's like you're having for +certain dynamical modes a small unit + + align:start position:0% +certain dynamical modes a small unit + + + align:start position:0% +certain dynamical modes a small unit +cell and so that means that they reflect + + align:start position:0% +cell and so that means that they reflect + + + align:start position:0% +cell and so that means that they reflect +back of the co graining + + align:start position:0% +back of the co graining + + + align:start position:0% +back of the co graining +interface and they hit your your region + + align:start position:0% +interface and they hit your your region + + + align:start position:0% +interface and they hit your your region +of action fairly quickly as soon as + + align:start position:0% +of action fairly quickly as soon as + + + align:start position:0% +of action fairly quickly as soon as +they're reflected back okay um so it's + + align:start position:0% +they're reflected back okay um so it's + + + align:start position:0% +they're reflected back okay um so it's +exactly the same as + + align:start position:0% +exactly the same as + + + align:start position:0% +exactly the same as +putting you know your Dynamics in a very + + align:start position:0% +putting you know your Dynamics in a very + + + align:start position:0% +putting you know your Dynamics in a very +small box except that the size of the + + align:start position:0% +small box except that the size of the + + + align:start position:0% +small box except that the size of the +box that the system feels is different + + align:start position:0% +box that the system feels is different + + + align:start position:0% +box that the system feels is different +for different wavelengths okay but so a + + align:start position:0% +for different wavelengths okay but so a + + + align:start position:0% +for different wavelengths okay but so a +certain amount of elastic Behavior gets + + align:start position:0% +certain amount of elastic Behavior gets + + + align:start position:0% +certain amount of elastic Behavior gets +reflected back um fairly quickly so the + + align:start position:0% +reflected back um fairly quickly so the + + + align:start position:0% +reflected back um fairly quickly so the +phon on transmission prom is a serious + + align:start position:0% + + + + align:start position:0% + +one um and the phon transmission one is + + align:start position:0% +one um and the phon transmission one is + + + align:start position:0% +one um and the phon transmission one is +usually recognized very well uh there's + + align:start position:0% +usually recognized very well uh there's + + + align:start position:0% +usually recognized very well uh there's +one that's not as well recognized but is + + align:start position:0% +one that's not as well recognized but is + + + align:start position:0% +one that's not as well recognized but is +probably in the long term just a beer + + align:start position:0% +probably in the long term just a beer + + + align:start position:0% +probably in the long term just a beer +it's um anytime you remove degrees of + + align:start position:0% +it's um anytime you remove degrees of + + + align:start position:0% +it's um anytime you remove degrees of +freedom you remove + + align:start position:0% +freedom you remove + + + align:start position:0% +freedom you remove +entropy okay because entropy is + + align:start position:0% +entropy okay because entropy is + + + align:start position:0% +entropy okay because entropy is +essentially a count of your degrees of + + align:start position:0% +essentially a count of your degrees of + + + align:start position:0% +essentially a count of your degrees of +freedom um you may not worry about that + + align:start position:0% +freedom um you may not worry about that + + + align:start position:0% +freedom um you may not worry about that +but the problem is that if you do + + align:start position:0% +but the problem is that if you do + + + align:start position:0% +but the problem is that if you do +Dynamics your system will equilibrate + + align:start position:0% +Dynamics your system will equilibrate + + + align:start position:0% +Dynamics your system will equilibrate +along certain derivatives of the entropy + + align:start position:0% +along certain derivatives of the entropy + + + align:start position:0% +along certain derivatives of the entropy +and you'll get them wrong if you get the + + align:start position:0% +and you'll get them wrong if you get the + + + align:start position:0% +and you'll get them wrong if you get the +entropy wrong you'll get its derivatives + + align:start position:0% +entropy wrong you'll get its derivatives + + + align:start position:0% +entropy wrong you'll get its derivatives +wrong and some of the ones that you may + + align:start position:0% +wrong and some of the ones that you may + + + align:start position:0% +wrong and some of the ones that you may +worry about uh are heat capacity which + + align:start position:0% +worry about uh are heat capacity which + + + align:start position:0% +worry about uh are heat capacity which +is the temperature derivative of the + + align:start position:0% +is the temperature derivative of the + + + align:start position:0% +is the temperature derivative of the +entropy but also this one which you may + + align:start position:0% +entropy but also this one which you may + + + align:start position:0% +entropy but also this one which you may +worry a lot more about if you do + + align:start position:0% +worry a lot more about if you do + + + align:start position:0% +worry a lot more about if you do +mechanical Behavior thermal expansion + + align:start position:0% +mechanical Behavior thermal expansion + + + align:start position:0% +mechanical Behavior thermal expansion +which is the volume derivative of the + + align:start position:0% +which is the volume derivative of the + + + align:start position:0% +which is the volume derivative of the +entropy remember if remember your maxal + + align:start position:0% +entropy remember if remember your maxal + + + align:start position:0% +entropy remember if remember your maxal +relations d s DV is essentially dvdt up + + align:start position:0% +relations d s DV is essentially dvdt up + + + align:start position:0% +relations d s DV is essentially dvdt up +to some factors so how the entropy Chang + + align:start position:0% +to some factors so how the entropy Chang + + + align:start position:0% +to some factors so how the entropy Chang +with volume determines the thermal + + align:start position:0% +with volume determines the thermal + + + align:start position:0% +with volume determines the thermal +expansion and that's why if you actually + + align:start position:0% +expansion and that's why if you actually + + + align:start position:0% +expansion and that's why if you actually +look + + align:start position:0% +look + + + align:start position:0% +look +back the slide I showed + + align:start position:0% +back the slide I showed + + + align:start position:0% +back the slide I showed +you when we Define the effective + + align:start position:0% +you when we Define the effective + + + align:start position:0% +you when we Define the effective +potential between atoms 1 and + + align:start position:0% +potential between atoms 1 and + + + align:start position:0% +potential between atoms 1 and +three there's actually a potential and + + align:start position:0% +three there's actually a potential and + + + align:start position:0% +three there's actually a potential and +then there's a + + align:start position:0% +then there's a + + + align:start position:0% +then there's a +part that doesn't contain the + + align:start position:0% +part that doesn't contain the + + + align:start position:0% +part that doesn't contain the +coordinates of one and + + align:start position:0% +coordinates of one and + + + align:start position:0% +coordinates of one and +three and it's essentially the entropy + + align:start position:0% +three and it's essentially the entropy + + + align:start position:0% +three and it's essentially the entropy +you've lost by removing no too you have + + align:start position:0% +you've lost by removing no too you have + + + align:start position:0% +you've lost by removing no too you have +to + + align:start position:0% +to + + + align:start position:0% +to +actually keep that entropy in the system + + align:start position:0% +actually keep that entropy in the system + + + align:start position:0% +actually keep that entropy in the system +if you want to get the total + + align:start position:0% +if you want to get the total + + + align:start position:0% +if you want to get the total +thermodynamic quantities right okay it's + + align:start position:0% +thermodynamic quantities right okay it's + + + align:start position:0% +thermodynamic quantities right okay it's +sort of like you can think of this of + + align:start position:0% +sort of like you can think of this of + + + align:start position:0% +sort of like you can think of this of +the you you see that this is obvious if + + align:start position:0% +the you you see that this is obvious if + + + align:start position:0% +the you you see that this is obvious if +you take the complete limit of removing + + align:start position:0% +you take the complete limit of removing + + + align:start position:0% +you take the complete limit of removing +all nodes or going to one node then you + + align:start position:0% +all nodes or going to one node then you + + + align:start position:0% +all nodes or going to one node then you +end up with Continuum + + align:start position:0% +end up with Continuum + + + align:start position:0% +end up with Continuum +Behavior and the degrees of freedom of + + align:start position:0% +Behavior and the degrees of freedom of + + + align:start position:0% +Behavior and the degrees of freedom of +Continuum Behavior are not the entropy + + align:start position:0% +Continuum Behavior are not the entropy + + + align:start position:0% +Continuum Behavior are not the entropy +you've actually + + align:start position:0% +you've actually + + + align:start position:0% +you've actually +removed all the dynamic motion when you + + align:start position:0% +removed all the dynamic motion when you + + + align:start position:0% +removed all the dynamic motion when you +go to Continuum Theory so unless you've + + align:start position:0% +go to Continuum Theory so unless you've + + + align:start position:0% +go to Continuum Theory so unless you've +kept track of the degrees of freedom and + + align:start position:0% +kept track of the degrees of freedom and + + + align:start position:0% +kept track of the degrees of freedom and +the entropy that they include um you've + + align:start position:0% +the entropy that they include um you've + + + align:start position:0% +the entropy that they include um you've +lost all your information about that + + align:start position:0% + + + + align:start position:0% + +so when you do something like this + + align:start position:0% +so when you do something like this + + + align:start position:0% +so when you do something like this +here these will actually if you define + + align:start position:0% +here these will actually if you define + + + align:start position:0% +here these will actually if you define +the potentials at a given temperature + + align:start position:0% +the potentials at a given temperature + + + align:start position:0% +the potentials at a given temperature +because the renormalization of potential + + align:start position:0% +because the renormalization of potential + + + align:start position:0% +because the renormalization of potential +depends on temperature um if you define + + align:start position:0% +depends on temperature um if you define + + + align:start position:0% +depends on temperature um if you define +this at a given temperature and you run + + align:start position:0% +this at a given temperature and you run + + + align:start position:0% +this at a given temperature and you run +this at any other temperature these + + align:start position:0% +this at any other temperature these + + + align:start position:0% +this at any other temperature these +regions will have different thermal + + align:start position:0% +regions will have different thermal + + + align:start position:0% +regions will have different thermal +expansions and so you'll build up + + align:start position:0% +expansions and so you'll build up + + + align:start position:0% +expansions and so you'll build up +internal strain in your system without + + align:start position:0% +internal strain in your system without + + + align:start position:0% +internal strain in your system without +knowing + + align:start position:0% + + + + align:start position:0% + +it ah + + align:start position:0% +it ah + + + align:start position:0% +it ah +I get a new color + + align:start position:0% +I get a new color + + + align:start position:0% +I get a new color +scheme there we go so if you take a + + align:start position:0% +scheme there we go so if you take a + + + align:start position:0% +scheme there we go so if you take a +simple pair potential model um these Co + + align:start position:0% +simple pair potential model um these Co + + + align:start position:0% +simple pair potential model um these Co +graining schemes work pretty well here's + + align:start position:0% +graining schemes work pretty well here's + + + align:start position:0% +graining schemes work pretty well here's +essentially a static property even + + align:start position:0% +essentially a static property even + + + align:start position:0% +essentially a static property even +though it has temperature in it but this + + align:start position:0% +though it has temperature in it but this + + + align:start position:0% +though it has temperature in it but this +is the strain in that 2D system versus + + align:start position:0% +is the strain in that 2D system versus + + + align:start position:0% +is the strain in that 2D system versus +the + + align:start position:0% +the + + + align:start position:0% +the +stress um and the the black curve + + align:start position:0% +stress um and the the black curve + + + align:start position:0% +stress um and the the black curve +underlying this is the full system so no + + align:start position:0% +underlying this is the full system so no + + + align:start position:0% +underlying this is the full system so no +Co graining and the red curve is that + + align:start position:0% +Co graining and the red curve is that + + + align:start position:0% +Co graining and the red curve is that +hor grain system that I showed you and + + align:start position:0% +hor grain system that I showed you and + + + align:start position:0% +hor grain system that I showed you and +you'll see even in the nonlinear part + + align:start position:0% +you'll see even in the nonlinear part + + + align:start position:0% +you'll see even in the nonlinear part +this does very well and it makes sense + + align:start position:0% +this does very well and it makes sense + + + align:start position:0% +this does very well and it makes sense +you know this kind of mechanical + + align:start position:0% +you know this kind of mechanical + + + align:start position:0% +you know this kind of mechanical +Behavior you know strain versus stress + + align:start position:0% +Behavior you know strain versus stress + + + align:start position:0% +Behavior you know strain versus stress +is largely dominated by the Potentials + + align:start position:0% +is largely dominated by the Potentials + + + align:start position:0% +is largely dominated by the Potentials +in these kind of solid system there's + + align:start position:0% +in these kind of solid system there's + + + align:start position:0% +in these kind of solid system there's +very little dynamical factors that play + + align:start position:0% +very little dynamical factors that play + + + align:start position:0% +very little dynamical factors that play +a role in it so as long as you normalize + + align:start position:0% +a role in it so as long as you normalize + + + align:start position:0% +a role in it so as long as you normalize +the potentials right you will get the + + align:start position:0% +the potentials right you will get the + + + align:start position:0% +the potentials right you will get the +stress strain relation right even in the + + align:start position:0% +stress strain relation right even in the + + + align:start position:0% +stress strain relation right even in the +nonlinear regime so that's not a big + + align:start position:0% +nonlinear regime so that's not a big + + + align:start position:0% +nonlinear regime so that's not a big +surprise + + align:start position:0% + + + + align:start position:0% + +if you keep track of the entropy right + + align:start position:0% +if you keep track of the entropy right + + + align:start position:0% +if you keep track of the entropy right +you'll get uh things like the heat + + align:start position:0% +you'll get uh things like the heat + + + align:start position:0% +you'll get uh things like the heat +capacities right uh this is the ratio + + align:start position:0% +capacities right uh this is the ratio + + + align:start position:0% +capacities right uh this is the ratio +between um the heat capacity in the + + align:start position:0% +between um the heat capacity in the + + + align:start position:0% +between um the heat capacity in the +nonhomogeneous system which is the cor + + align:start position:0% +nonhomogeneous system which is the cor + + + align:start position:0% +nonhomogeneous system which is the cor +grain system divided by the exact result + + align:start position:0% +grain system divided by the exact result + + + align:start position:0% +grain system divided by the exact result +you could say the heat capacity and the + + align:start position:0% +you could say the heat capacity and the + + + align:start position:0% +you could say the heat capacity and the +homogeneous it essentially oscillates + + align:start position:0% +homogeneous it essentially oscillates + + + align:start position:0% +homogeneous it essentially oscillates +around one U as a function of + + align:start position:0% +around one U as a function of + + + align:start position:0% +around one U as a function of +temperature so by construction you + + align:start position:0% +temperature so by construction you + + + align:start position:0% +temperature so by construction you +pretty much have that right + + align:start position:0% + + + + align:start position:0% + +but so here it gets more interesting um + + align:start position:0% +but so here it gets more interesting um + + + align:start position:0% +but so here it gets more interesting um +if you look at heat + + align:start position:0% +if you look at heat + + + align:start position:0% +if you look at heat +conduction through a coar grained + + align:start position:0% +conduction through a coar grained + + + align:start position:0% +conduction through a coar grained +interface so let's say you're fine at + + align:start position:0% +interface so let's say you're fine at + + + align:start position:0% +interface so let's say you're fine at +this side these are let's say these are + + align:start position:0% +this side these are let's say these are + + + align:start position:0% +this side these are let's say these are +atoms and here we've + + align:start position:0% +atoms and here we've + + + align:start position:0% +atoms and here we've +removed uh a bunch of nodes we've Co + + align:start position:0% +removed uh a bunch of nodes we've Co + + + align:start position:0% +removed uh a bunch of nodes we've Co +grained and so you look at the heat + + align:start position:0% +grained and so you look at the heat + + + align:start position:0% +grained and so you look at the heat +conduction through this so you set up a + + align:start position:0% +conduction through this so you set up a + + + align:start position:0% +conduction through this so you set up a +temperature gradient and essentially + + align:start position:0% +temperature gradient and essentially + + + align:start position:0% +temperature gradient and essentially +look at the heat flux when you do + + align:start position:0% +look at the heat flux when you do + + + align:start position:0% +look at the heat flux when you do +Dynamics so what this is showing here is + + align:start position:0% +Dynamics so what this is showing here is + + + align:start position:0% +Dynamics so what this is showing here is +um the heat conduction the the heat + + align:start position:0% +um the heat conduction the the heat + + + align:start position:0% +um the heat conduction the the heat +conduction in the non-homogeneous system + + align:start position:0% +conduction in the non-homogeneous system + + + align:start position:0% +conduction in the non-homogeneous system +divide by the heat conduction in the + + align:start position:0% +divide by the heat conduction in the + + + align:start position:0% +divide by the heat conduction in the +homogeneous system and this is pretty + + align:start position:0% +homogeneous system and this is pretty + + + align:start position:0% +homogeneous system and this is pretty +much always lower than one so the + + align:start position:0% +much always lower than one so the + + + align:start position:0% +much always lower than one so the +non-homogeneous system has less heat + + align:start position:0% +non-homogeneous system has less heat + + + align:start position:0% +non-homogeneous system has less heat +conduction and the reason is you scatter + + align:start position:0% +conduction and the reason is you scatter + + + align:start position:0% +conduction and the reason is you scatter +phonons of this + + align:start position:0% +phonons of this + + + align:start position:0% +phonons of this +interface okay so here there's a certain + + align:start position:0% +interface okay so here there's a certain + + + align:start position:0% +interface okay so here there's a certain +amount of phonons that get reflected + + align:start position:0% +amount of phonons that get reflected + + + align:start position:0% +amount of phonons that get reflected +back but it's + + align:start position:0% +back but it's + + + align:start position:0% +back but it's +interesting if you show this here as a + + align:start position:0% +interesting if you show this here as a + + + align:start position:0% +interesting if you show this here as a +function of the length of the hom genous + + align:start position:0% +function of the length of the hom genous + + + align:start position:0% +function of the length of the hom genous +system okay you do better and better as + + align:start position:0% +system okay you do better and better as + + + align:start position:0% +system okay you do better and better as +this system gets bigger and that makes + + align:start position:0% +this system gets bigger and that makes + + + align:start position:0% +this system gets bigger and that makes +sense because then the interface becomes + + align:start position:0% +sense because then the interface becomes + + + align:start position:0% +sense because then the interface becomes +less and less important but you know + + align:start position:0% +less and less important but you know + + + align:start position:0% +less and less important but you know +look at the size here um you know to get + + align:start position:0% +look at the size here um you know to get + + + align:start position:0% +look at the size here um you know to get +up to sort of about one you need about + + align:start position:0% +up to sort of about one you need about + + + align:start position:0% +up to sort of about one you need about +1,500 atoms in the homogeneous + + align:start position:0% +1,500 atoms in the homogeneous + + + align:start position:0% +1,500 atoms in the homogeneous +region so this is a major problem with + + align:start position:0% +region so this is a major problem with + + + align:start position:0% +region so this is a major problem with +foun in general I think of all any + + align:start position:0% +foun in general I think of all any + + + align:start position:0% +foun in general I think of all any +atomistic level phenomena phonons are + + align:start position:0% +atomistic level phenomena phonons are + + + align:start position:0% +atomistic level phenomena phonons are +probably the ones that have the largest + + align:start position:0% +probably the ones that have the largest + + + align:start position:0% +probably the ones that have the largest +length scale the phonon mean free pad a + + align:start position:0% +length scale the phonon mean free pad a + + + align:start position:0% +length scale the phonon mean free pad a +low temperature is enormous it's can you + + align:start position:0% +low temperature is enormous it's can you + + + align:start position:0% +low temperature is enormous it's can you +know it's thousands of atoms far that + + align:start position:0% +know it's thousands of atoms far that + + + align:start position:0% +know it's thousands of atoms far that +means that phonons are usually the first + + align:start position:0% +means that phonons are usually the first + + + align:start position:0% +means that phonons are usually the first +thing to see something far away there's + + align:start position:0% +thing to see something far away there's + + + align:start position:0% +thing to see something far away there's +they're the first thing to see finite + + align:start position:0% +they're the first thing to see finite + + + align:start position:0% +they're the first thing to see finite +size effects there the first thing to + + align:start position:0% +size effects there the first thing to + + + align:start position:0% +size effects there the first thing to +see scattering of interfaces because you + + align:start position:0% +see scattering of interfaces because you + + + align:start position:0% +see scattering of interfaces because you +know the reason is that a lot of systems + + align:start position:0% +know the reason is that a lot of systems + + + align:start position:0% +know the reason is that a lot of systems +behave at low temperature fairly + + align:start position:0% +behave at low temperature fairly + + + align:start position:0% +behave at low temperature fairly +harmonic + + align:start position:0% +harmonic + + + align:start position:0% +harmonic +that means that these phonons just + + align:start position:0% +that means that these phonons just + + + align:start position:0% +that means that these phonons just +travel and travel and travel and their + + align:start position:0% +travel and travel and travel and their + + + align:start position:0% +travel and travel and travel and their +probability of being scattered is pretty + + align:start position:0% +probability of being scattered is pretty + + + align:start position:0% +probability of being scattered is pretty +low it's only as they start becoming + + align:start position:0% +low it's only as they start becoming + + + align:start position:0% +low it's only as they start becoming +inharmonic that they scatter um of + + align:start position:0% +inharmonic that they scatter um of + + + align:start position:0% +inharmonic that they scatter um of +course they could scatter off Disorder + + align:start position:0% +course they could scatter off Disorder + + + align:start position:0% +course they could scatter off Disorder +so if you have disordered systems that + + align:start position:0% +so if you have disordered systems that + + + align:start position:0% +so if you have disordered systems that +mean free path is a lot lower but phons + + align:start position:0% +mean free path is a lot lower but phons + + + align:start position:0% +mean free path is a lot lower but phons +you know often see hundreds of angstrom + + align:start position:0% +you know often see hundreds of angstrom + + + align:start position:0% +you know often see hundreds of angstrom +far essentially + + align:start position:0% + + + + align:start position:0% + +okay here's the same result as a + + align:start position:0% +okay here's the same result as a + + + align:start position:0% +okay here's the same result as a +function of + + align:start position:0% +function of + + + align:start position:0% +function of +temperature so the heat capacity versus + + align:start position:0% +temperature so the heat capacity versus + + + align:start position:0% +temperature so the heat capacity versus +the normalized temperature uh this is + + align:start position:0% +the normalized temperature uh this is + + + align:start position:0% +the normalized temperature uh this is +the real system so the these are uh this + + align:start position:0% +the real system so the these are uh this + + + align:start position:0% +the real system so the these are uh this +is a fully atomistic level system and + + align:start position:0% +is a fully atomistic level system and + + + align:start position:0% +is a fully atomistic level system and +this is the um in red here is the + + align:start position:0% +this is the um in red here is the + + + align:start position:0% +this is the um in red here is the +partially coed grain system in this case + + align:start position:0% +partially coed grain system in this case + + + align:start position:0% +partially coed grain system in this case +with two interfaces and what you see is + + align:start position:0% +with two interfaces and what you see is + + + align:start position:0% +with two interfaces and what you see is +the co grain system always has lower + + align:start position:0% +the co grain system always has lower + + + align:start position:0% +the co grain system always has lower +heat conductance um they tend tend to + + align:start position:0% +heat conductance um they tend tend to + + + align:start position:0% +heat conductance um they tend tend to +come a little closer together at higher + + align:start position:0% +come a little closer together at higher + + + align:start position:0% +come a little closer together at higher +temperature and the reason is at higher + + align:start position:0% +temperature and the reason is at higher + + + align:start position:0% +temperature and the reason is at higher +temperature you have more inharmonicity + + align:start position:0% +temperature you have more inharmonicity + + + align:start position:0% +temperature you have more inharmonicity +so the phonons have a shorter mean-free + + align:start position:0% +so the phonons have a shorter mean-free + + + align:start position:0% +so the phonons have a shorter mean-free +PAAD so they tend to see you know they + + align:start position:0% +PAAD so they tend to see you know they + + + align:start position:0% +PAAD so they tend to see you know they +tend to homogenize easier and don't see + + align:start position:0% +tend to homogenize easier and don't see + + + align:start position:0% +tend to homogenize easier and don't see +the interfaces um as + + align:start position:0% + + + + align:start position:0% + +much okay let me skip this okay um so + + align:start position:0% +much okay let me skip this okay um so + + + align:start position:0% +much okay let me skip this okay um so +that's some of the efforts going on in + + align:start position:0% +that's some of the efforts going on in + + + align:start position:0% +that's some of the efforts going on in +um Co graining over + + align:start position:0% + + + + align:start position:0% + +space u you know I think if you if you + + align:start position:0% +space u you know I think if you if you + + + align:start position:0% +space u you know I think if you if you +if there's an area in which you want to + + align:start position:0% +if there's an area in which you want to + + + align:start position:0% +if there's an area in which you want to +work and have high impact this is + + align:start position:0% +work and have high impact this is + + + align:start position:0% +work and have high impact this is +probably one um I haven't seen a single + + align:start position:0% +probably one um I haven't seen a single + + + align:start position:0% +probably one um I haven't seen a single +good idea in this field in the last 10 + + align:start position:0% +good idea in this field in the last 10 + + + align:start position:0% +good idea in this field in the last 10 +years I probably shouldn't say this on + + align:start position:0% +years I probably shouldn't say this on + + + align:start position:0% +years I probably shouldn't say this on +tape but um you know this is a field + + align:start position:0% +tape but um you know this is a field + + + align:start position:0% +tape but um you know this is a field +that where progress is desperately + + align:start position:0% +that where progress is desperately + + + align:start position:0% +that where progress is desperately +needed and it's a really really hard + + align:start position:0% +needed and it's a really really hard + + + align:start position:0% +needed and it's a really really hard +problem uh because you're essentially + + align:start position:0% +problem uh because you're essentially + + + align:start position:0% +problem uh because you're essentially +asking the question what is the Dynamics + + align:start position:0% +asking the question what is the Dynamics + + + align:start position:0% +asking the question what is the Dynamics +of partially Co grain + + align:start position:0% +of partially Co grain + + + align:start position:0% +of partially Co grain +systems and the pro the reason it's so + + align:start position:0% +systems and the pro the reason it's so + + + align:start position:0% +systems and the pro the reason it's so +hard that it's that it's a mixture of + + align:start position:0% +hard that it's that it's a mixture of + + + align:start position:0% +hard that it's that it's a mixture of +sort of Newtonian mechanics which is + + align:start position:0% +sort of Newtonian mechanics which is + + + align:start position:0% +sort of Newtonian mechanics which is +energy + + align:start position:0% +energy + + + align:start position:0% +energy +conserving and dissipative + + align:start position:0% +conserving and dissipative + + + align:start position:0% +conserving and dissipative +Dynamics okay and you have to sort of + + align:start position:0% +Dynamics okay and you have to sort of + + + align:start position:0% +Dynamics okay and you have to sort of +and that how you mix those essentially + + align:start position:0% +and that how you mix those essentially + + + align:start position:0% +and that how you mix those essentially +depends on the frequency of your + + align:start position:0% +depends on the frequency of your + + + align:start position:0% +depends on the frequency of your +motion uh and that's why this is such a + + align:start position:0% +motion uh and that's why this is such a + + + align:start position:0% +motion uh and that's why this is such a +hard problem people have tried things + + align:start position:0% +hard problem people have tried things + + + align:start position:0% +hard problem people have tried things +where you know with boundaries that have + + align:start position:0% +where you know with boundaries that have + + + align:start position:0% +where you know with boundaries that have +complex impedance + + align:start position:0% +complex impedance + + + align:start position:0% +complex impedance +where essentially your transmission + + align:start position:0% +where essentially your transmission + + + align:start position:0% +where essentially your transmission +through the boundary is frequency + + align:start position:0% +through the boundary is frequency + + + align:start position:0% +through the boundary is frequency +dependent and you can see with that way + + align:start position:0% +dependent and you can see with that way + + + align:start position:0% +dependent and you can see with that way +you can definitely sort of tailor better + + align:start position:0% +you can definitely sort of tailor better + + + align:start position:0% +you can definitely sort of tailor better +what the phons do okay because now you + + align:start position:0% +what the phons do okay because now you + + + align:start position:0% +what the phons do okay because now you +have a much more complex interface + + align:start position:0% +have a much more complex interface + + + align:start position:0% +have a much more complex interface +literally to control you know the + + align:start position:0% +literally to control you know the + + + align:start position:0% +literally to control you know the +problem is that some of these things you + + align:start position:0% +problem is that some of these things you + + + align:start position:0% +problem is that some of these things you +can make work but they get so + + align:start position:0% +can make work but they get so + + + align:start position:0% +can make work but they get so +complicated to implement that they're NE + + align:start position:0% +complicated to implement that they're NE + + + align:start position:0% +complicated to implement that they're NE +not necessarily very practical other + + align:start position:0% +not necessarily very practical other + + + align:start position:0% +not necessarily very practical other +people do things with large overlapping + + align:start position:0% +people do things with large overlapping + + + align:start position:0% +people do things with large overlapping +regions you could say you know one way + + align:start position:0% +regions you could say you know one way + + + align:start position:0% +regions you could say you know one way +to Sol this problem is to not have these + + align:start position:0% +to Sol this problem is to not have these + + + align:start position:0% +to Sol this problem is to not have these +sharp boundaries between different + + align:start position:0% +sharp boundaries between different + + + align:start position:0% +sharp boundaries between different +levels of Co graining but overlap the + + align:start position:0% +levels of Co graining but overlap the + + + align:start position:0% +levels of Co graining but overlap the +two regions and slowly force that in the + + align:start position:0% +two regions and slowly force that in the + + + align:start position:0% +two regions and slowly force that in the +overlap region the solution say to the + + align:start position:0% +overlap region the solution say to the + + + align:start position:0% +overlap region the solution say to the +displacement fields are the same + + align:start position:0% +displacement fields are the same + + + align:start position:0% +displacement fields are the same +um okay the the next thing I want to + + align:start position:0% +um okay the the next thing I want to + + + align:start position:0% +um okay the the next thing I want to +talk about is U accelerating time um I + + align:start position:0% +talk about is U accelerating time um I + + + align:start position:0% +talk about is U accelerating time um I +said without Einstein but I think + + align:start position:0% +said without Einstein but I think + + + align:start position:0% +said without Einstein but I think +Einstein only could slow down time isn't + + align:start position:0% +Einstein only could slow down time isn't + + + align:start position:0% +Einstein only could slow down time isn't +that right I'm not sure we can + + align:start position:0% +that right I'm not sure we can + + + align:start position:0% +that right I'm not sure we can +accelerate I don't know + + align:start position:0% +accelerate I don't know + + + align:start position:0% +accelerate I don't know +um I don't know my theory of relativity + + align:start position:0% +um I don't know my theory of relativity + + + align:start position:0% +um I don't know my theory of relativity +too well anymore um I think I don't have + + align:start position:0% +too well anymore um I think I don't have + + + align:start position:0% +too well anymore um I think I don't have +to convince you you've done MD uh why + + align:start position:0% +to convince you you've done MD uh why + + + align:start position:0% +to convince you you've done MD uh why +you need to speed up time sometimes most + + align:start position:0% +you need to speed up time sometimes most + + + align:start position:0% +you need to speed up time sometimes most +of what I'm going to say comes out of + + align:start position:0% +of what I'm going to say comes out of + + + align:start position:0% +of what I'm going to say comes out of +this review article by Art voter uh + + align:start position:0% +this review article by Art voter uh + + + align:start position:0% +this review article by Art voter uh +who's probably been the guy to like work + + align:start position:0% +who's probably been the guy to like work + + + align:start position:0% +who's probably been the guy to like work +on accelerated MD methods uh and I'll + + align:start position:0% +on accelerated MD methods uh and I'll + + + align:start position:0% +on accelerated MD methods uh and I'll +give you the references again at the end + + align:start position:0% +give you the references again at the end + + + align:start position:0% +give you the references again at the end +this is a great review if you want to + + align:start position:0% +this is a great review if you want to + + + align:start position:0% +this is a great review if you want to +read about + + align:start position:0% + + + + align:start position:0% + +this um cuz there's some really clever + + align:start position:0% +this um cuz there's some really clever + + + align:start position:0% +this um cuz there's some really clever +stuff in here that I think even if you + + align:start position:0% +stuff in here that I think even if you + + + align:start position:0% +stuff in here that I think even if you +don't want to do accelerate MD that you + + align:start position:0% +don't want to do accelerate MD that you + + + align:start position:0% +don't want to do accelerate MD that you +could use for for other um things um so + + align:start position:0% +could use for for other um things um so + + + align:start position:0% +could use for for other um things um so +first of all what's the problem um you + + align:start position:0% +first of all what's the problem um you + + + align:start position:0% +first of all what's the problem um you +know the problem is obviously that in + + align:start position:0% +know the problem is obviously that in + + + align:start position:0% +know the problem is obviously that in +most systems that are fairly U + + align:start position:0% +most systems that are fairly U + + + align:start position:0% +most systems that are fairly U +dense uh you have well defined minim in + + align:start position:0% +dense uh you have well defined minim in + + + align:start position:0% +dense uh you have well defined minim in +face space and often the barriers + + align:start position:0% +face space and often the barriers + + + align:start position:0% +face space and often the barriers +between them are pretty high so you + + align:start position:0% +between them are pretty high so you + + + align:start position:0% +between them are pretty high so you +sample the transitions between them at a + + align:start position:0% +sample the transitions between them at a + + + align:start position:0% +sample the transitions between them at a +very low rate uh the rate is essentially + + align:start position:0% +very low rate uh the rate is essentially + + + align:start position:0% +very low rate uh the rate is essentially +proportional to the exponential of the + + align:start position:0% +proportional to the exponential of the + + + align:start position:0% +proportional to the exponential of the +activation barrier between the Min and + + align:start position:0% +activation barrier between the Min and + + + align:start position:0% +activation barrier between the Min and +like I said in a lot of condensed + + align:start position:0% +like I said in a lot of condensed + + + align:start position:0% +like I said in a lot of condensed +systems those activation barriers uh are + + align:start position:0% +systems those activation barriers uh are + + + align:start position:0% +systems those activation barriers uh are +quite high and lead to time scales that + + align:start position:0% +quite high and lead to time scales that + + + align:start position:0% +quite high and lead to time scales that +you can't quite uh + + align:start position:0% + + + + align:start position:0% + +sample um so I'm going to talk briefly + + align:start position:0% +sample um so I'm going to talk briefly + + + align:start position:0% +sample um so I'm going to talk briefly +about three different methods to speed + + align:start position:0% +about three different methods to speed + + + align:start position:0% +about three different methods to speed +up time um parallel replica Dynamics + + align:start position:0% +up time um parallel replica Dynamics + + + align:start position:0% +up time um parallel replica Dynamics +hyper dynamics and temperature + + align:start position:0% +hyper dynamics and temperature + + + align:start position:0% +hyper dynamics and temperature +accelerated Dynamics + + align:start position:0% +accelerated Dynamics + + + align:start position:0% +accelerated Dynamics +um okay let me sort of quickly review + + align:start position:0% +um okay let me sort of quickly review + + + align:start position:0% +um okay let me sort of quickly review +what you would do with transition state + + align:start position:0% +what you would do with transition state + + + align:start position:0% +what you would do with transition state +Theory so if you knew the transitions + + align:start position:0% +Theory so if you knew the transitions + + + align:start position:0% +Theory so if you knew the transitions +that a system had to make like in a say + + align:start position:0% +that a system had to make like in a say + + + align:start position:0% +that a system had to make like in a say +a simple molecular reaction uh then you + + align:start position:0% +a simple molecular reaction uh then you + + + align:start position:0% +a simple molecular reaction uh then you +really don't need to do a simulation + + align:start position:0% +really don't need to do a simulation + + + align:start position:0% +really don't need to do a simulation +because if you know the activation + + align:start position:0% +because if you know the activation + + + align:start position:0% +because if you know the activation +barrier this quantity and you have some + + align:start position:0% +barrier this quantity and you have some + + + align:start position:0% +barrier this quantity and you have some +idea of the frequency with which the + + align:start position:0% +idea of the frequency with which the + + + align:start position:0% +idea of the frequency with which the +system tries to cross that barrier you + + align:start position:0% +system tries to cross that barrier you + + + align:start position:0% +system tries to cross that barrier you +know you can do Transition State Theory + + align:start position:0% +know you can do Transition State Theory + + + align:start position:0% +know you can do Transition State Theory +and essentially say that the The + + align:start position:0% +and essentially say that the The + + + align:start position:0% +and essentially say that the The +Crossing rate is going to be something + + align:start position:0% +Crossing rate is going to be something + + + align:start position:0% +Crossing rate is going to be something +like the attempt rate New Times the + + align:start position:0% +like the attempt rate New Times the + + + align:start position:0% +like the attempt rate New Times the +success rate which is this Bol Factor + + align:start position:0% +success rate which is this Bol Factor + + + align:start position:0% +success rate which is this Bol Factor +you know and the chemists among you and + + align:start position:0% +you know and the chemists among you and + + + align:start position:0% +you know and the chemists among you and +chemical Engineers know there's all + + align:start position:0% +chemical Engineers know there's all + + + align:start position:0% +chemical Engineers know there's all +kinds of approximations in there but + + align:start position:0% +kinds of approximations in there but + + + align:start position:0% +kinds of approximations in there but +none of them are particularly severe for + + align:start position:0% +none of them are particularly severe for + + + align:start position:0% +none of them are particularly severe for +most things to study like one + + align:start position:0% +most things to study like one + + + align:start position:0% +most things to study like one +approximation is this assumes you don't + + align:start position:0% +approximation is this assumes you don't + + + align:start position:0% +approximation is this assumes you don't +cross + + align:start position:0% +cross + + + align:start position:0% +cross +back uh often you know when you sit at + + align:start position:0% +back uh often you know when you sit at + + + align:start position:0% +back uh often you know when you sit at +the transition state you're essentially + + align:start position:0% +the transition state you're essentially + + + align:start position:0% +the transition state you're essentially +assuming that you fall over and don't + + align:start position:0% +assuming that you fall over and don't + + + align:start position:0% +assuming that you fall over and don't +cross back the other approximation is + + align:start position:0% +cross back the other approximation is + + + align:start position:0% +cross back the other approximation is +that this assumes that the transitions + + align:start position:0% +that this assumes that the transitions + + + align:start position:0% +that this assumes that the transitions +are infrequent compared to the + + align:start position:0% +are infrequent compared to the + + + align:start position:0% +are infrequent compared to the +vibrations in the minimum so you assume + + align:start position:0% +vibrations in the minimum so you assume + + + align:start position:0% +vibrations in the minimum so you assume +that when the system goes from here to + + align:start position:0% +that when the system goes from here to + + + align:start position:0% +that when the system goes from here to +here it sort of equilibrates here + + align:start position:0% +here it sort of equilibrates here + + + align:start position:0% +here it sort of equilibrates here +vibrates around until it makes a the + + align:start position:0% +vibrates around until it makes a the + + + align:start position:0% +vibrates around until it makes a the +next + + align:start position:0% +next + + + align:start position:0% +next +transition and the reason you need to do + + align:start position:0% +transition and the reason you need to do + + + align:start position:0% +transition and the reason you need to do +that is that um you need to equilibrate + + align:start position:0% +that is that um you need to equilibrate + + + align:start position:0% +that is that um you need to equilibrate +First in every potential well before you + + align:start position:0% +First in every potential well before you + + + align:start position:0% +First in every potential well before you +go to the next one because otherwise you + + align:start position:0% +go to the next one because otherwise you + + + align:start position:0% +go to the next one because otherwise you +have dynamical memory left from the + + align:start position:0% +have dynamical memory left from the + + + align:start position:0% +have dynamical memory left from the +previous transition which which + + align:start position:0% +previous transition which which + + + align:start position:0% +previous transition which which +essentially change your statistic would + + align:start position:0% +essentially change your statistic would + + + align:start position:0% +essentially change your statistic would +make your statistical mechanics approach + + align:start position:0% +make your statistical mechanics approach + + + align:start position:0% +make your statistical mechanics approach +invalid um but usually those are um easy + + align:start position:0% +invalid um but usually those are um easy + + + align:start position:0% +invalid um but usually those are um easy +to deal with um it's sort of obvious + + align:start position:0% +to deal with um it's sort of obvious + + + align:start position:0% +to deal with um it's sort of obvious +because if you think about if the system + + align:start position:0% +because if you think about if the system + + + align:start position:0% +because if you think about if the system +crosses very rapidly compared to the + + align:start position:0% +crosses very rapidly compared to the + + + align:start position:0% +crosses very rapidly compared to the +time it vibrates then you just do molec + + align:start position:0% +time it vibrates then you just do molec + + + align:start position:0% +time it vibrates then you just do molec +Dynamics because then you have very fast + + align:start position:0% +Dynamics because then you have very fast + + + align:start position:0% +Dynamics because then you have very fast +transition so who cares about transition + + align:start position:0% +transition so who cares about transition + + + align:start position:0% +transition so who cares about transition +state + + align:start position:0% + + + + align:start position:0% + +Theory okay + + align:start position:0% +Theory okay + + + align:start position:0% +Theory okay +so the parallel replica method is really + + align:start position:0% +so the parallel replica method is really + + + align:start position:0% +so the parallel replica method is really +kind of elegant in its triviality almost + + align:start position:0% +kind of elegant in its triviality almost + + + align:start position:0% +kind of elegant in its triviality almost +um if you think of you know what is time + + align:start position:0% +um if you think of you know what is time + + + align:start position:0% +um if you think of you know what is time +time is waiting for events to happen um + + align:start position:0% +time is waiting for events to happen um + + + align:start position:0% +time is waiting for events to happen um +and if you think of a really trivial + + align:start position:0% +and if you think of a really trivial + + + align:start position:0% +and if you think of a really trivial +example you know let's say the system + + align:start position:0% +example you know let's say the system + + + align:start position:0% +example you know let's say the system +wants to move from this state to that + + align:start position:0% +wants to move from this state to that + + + align:start position:0% +wants to move from this state to that +state you're just sitting there you know + + align:start position:0% +state you're just sitting there you know + + + align:start position:0% +state you're just sitting there you know +the atoms are vibrating around and + + align:start position:0% +the atoms are vibrating around and + + + align:start position:0% +the atoms are vibrating around and +waiting you're waiting for the system to + + align:start position:0% +waiting you're waiting for the system to + + + align:start position:0% +waiting you're waiting for the system to +to transition why not wait on many + + align:start position:0% +to transition why not wait on many + + + align:start position:0% +to transition why not wait on many +processors at a time + + align:start position:0% +processors at a time + + + align:start position:0% +processors at a time +so the idea is you run this simulation + + align:start position:0% +so the idea is you run this simulation + + + align:start position:0% +so the idea is you run this simulation +on a bunch of + + align:start position:0% +on a bunch of + + + align:start position:0% +on a bunch of +processors and if you run on say 100 you + + align:start position:0% +processors and if you run on say 100 you + + + align:start position:0% +processors and if you run on say 100 you +could say that's kind of like waiting a + + align:start position:0% +could say that's kind of like waiting a + + + align:start position:0% +could say that's kind of like waiting a +100 times the time you wait on One + + align:start position:0% +100 times the time you wait on One + + + align:start position:0% +100 times the time you wait on One +processor and then let's say it happens + + align:start position:0% +processor and then let's say it happens + + + align:start position:0% +processor and then let's say it happens +at on One + + align:start position:0% +at on One + + + align:start position:0% +at on One +processor okay the system transitions + + align:start position:0% +processor okay the system transitions + + + align:start position:0% +processor okay the system transitions +then you essentially add up all the time + + align:start position:0% +then you essentially add up all the time + + + align:start position:0% +then you essentially add up all the time +all the systems have waited and that's + + align:start position:0% +all the systems have waited and that's + + + align:start position:0% +all the systems have waited and that's +your total waiting time and in a + + align:start position:0% +your total waiting time and in a + + + align:start position:0% +your total waiting time and in a +statistical sense that's actually right + + align:start position:0% +statistical sense that's actually right + + + align:start position:0% +statistical sense that's actually right +you know if you do queuing Theory and + + align:start position:0% +you know if you do queuing Theory and + + + align:start position:0% +you know if you do queuing Theory and +things like that you'll find that this + + align:start position:0% +things like that you'll find that this + + + align:start position:0% +things like that you'll find that this +is the solution if you it's actually + + align:start position:0% +is the solution if you it's actually + + + align:start position:0% +is the solution if you it's actually +easy to see if you turn this all into + + align:start position:0% +easy to see if you turn this all into + + + align:start position:0% +easy to see if you turn this all into +probabilities for transfer you know + + align:start position:0% +probabilities for transfer you know + + + align:start position:0% +probabilities for transfer you know +essentially you could say when when you + + align:start position:0% +essentially you could say when when you + + + align:start position:0% +essentially you could say when when you +do it 100 times you've 100 times + + align:start position:0% +do it 100 times you've 100 times + + + align:start position:0% +do it 100 times you've 100 times +attempted or given the system chances in + + align:start position:0% +attempted or given the system chances in + + + align:start position:0% +attempted or given the system chances in +a given time to make a transition so you + + align:start position:0% +a given time to make a transition so you + + + align:start position:0% +a given time to make a transition so you +add up all the time and then you just + + align:start position:0% +add up all the time and then you just + + + align:start position:0% +add up all the time and then you just +restart so you put the system in the + + align:start position:0% +restart so you put the system in the + + + align:start position:0% +restart so you put the system in the +next + + align:start position:0% +next + + + align:start position:0% +next +state and you again run all those + + align:start position:0% +state and you again run all those + + + align:start position:0% +state and you again run all those +replicas you do you have to introduce a + + align:start position:0% +replicas you do you have to introduce a + + + align:start position:0% +replicas you do you have to introduce a +little bit of randomization of course + + align:start position:0% +little bit of randomization of course + + + align:start position:0% +little bit of randomization of course +you don't want these to fall exactly the + + align:start position:0% +you don't want these to fall exactly the + + + align:start position:0% +you don't want these to fall exactly the +same trajectory through face space okay + + align:start position:0% +same trajectory through face space okay + + + align:start position:0% +same trajectory through face space okay +so there's a certain amount of + + align:start position:0% +so there's a certain amount of + + + align:start position:0% +so there's a certain amount of +randomization that goes on um so + + align:start position:0% +randomization that goes on um so + + + align:start position:0% +randomization that goes on um so +essentially this is linear time scaling + + align:start position:0% +essentially this is linear time scaling + + + align:start position:0% +essentially this is linear time scaling +you know o overall you pretty much you + + align:start position:0% +you know o overall you pretty much you + + + align:start position:0% +you know o overall you pretty much you +know if you have n processors time is + + align:start position:0% +know if you have n processors time is + + + align:start position:0% +know if you have n processors time is +accelerated by a factor of n you could + + align:start position:0% +accelerated by a factor of n you could + + + align:start position:0% +accelerated by a factor of n you could +say it's a little less because there's + + align:start position:0% +say it's a little less because there's + + + align:start position:0% +say it's a little less because there's +overhead you know you have to first of + + align:start position:0% +overhead you know you have to first of + + + align:start position:0% +overhead you know you have to first of +all do a non-trivial thing which is + + align:start position:0% +all do a non-trivial thing which is + + + align:start position:0% +all do a non-trivial thing which is +detect the transition when you think + + align:start position:0% +detect the transition when you think + + + align:start position:0% +detect the transition when you think +about it this is kind of you know not + + align:start position:0% +about it this is kind of you know not + + + align:start position:0% +about it this is kind of you know not +that trivial you're doing your md + + align:start position:0% +that trivial you're doing your md + + + align:start position:0% +that trivial you're doing your md +simulation and you got to sort of ask + + align:start position:0% +simulation and you got to sort of ask + + + align:start position:0% +simulation and you got to sort of ask +your system oh has something happened + + align:start position:0% +your system oh has something happened + + + align:start position:0% +your system oh has something happened +and you know maybe it's like an atom + + align:start position:0% +and you know maybe it's like an atom + + + align:start position:0% +and you know maybe it's like an atom +diffusing whatever so you got to do + + align:start position:0% +diffusing whatever so you got to do + + + align:start position:0% +diffusing whatever so you got to do +quite a bit of work to sort of check + + align:start position:0% +quite a bit of work to sort of check + + + align:start position:0% +quite a bit of work to sort of check +whether a transition that happen so you + + align:start position:0% +whether a transition that happen so you + + + align:start position:0% +whether a transition that happen so you +got overhead there and then you have + + align:start position:0% +got overhead there and then you have + + + align:start position:0% +got overhead there and then you have +overhead when you sort of copy the the + + align:start position:0% +overhead when you sort of copy the the + + + align:start position:0% +overhead when you sort of copy the the +the trans transition state into all the + + align:start position:0% +the trans transition state into all the + + + align:start position:0% +the trans transition state into all the +other ones you have to do a little bit + + align:start position:0% +other ones you have to do a little bit + + + align:start position:0% +other ones you have to do a little bit +of randomization here so typically you + + align:start position:0% +of randomization here so typically you + + + align:start position:0% +of randomization here so typically you +like you may restart with a different + + align:start position:0% +like you may restart with a different + + + align:start position:0% +like you may restart with a different +uh like with a maxal boltman + + align:start position:0% +uh like with a maxal boltman + + + align:start position:0% +uh like with a maxal boltman +distribution of velocities and so but + + align:start position:0% +distribution of velocities and so but + + + align:start position:0% +distribution of velocities and so but +you have to like initialize that you + + align:start position:0% +you have to like initialize that you + + + align:start position:0% +you have to like initialize that you +have to run that for a very short time + + align:start position:0% +have to run that for a very short time + + + align:start position:0% +have to run that for a very short time +and so so you have a bit of overhead + + align:start position:0% +and so so you have a bit of overhead + + + align:start position:0% +and so so you have a bit of overhead +there so you'll get a little less than + + align:start position:0% +there so you'll get a little less than + + + align:start position:0% +there so you'll get a little less than +uh and scaling um but you know it's not + + align:start position:0% +uh and scaling um but you know it's not + + + align:start position:0% +uh and scaling um but you know it's not +bad it's not great either but like I + + align:start position:0% +bad it's not great either but like I + + + align:start position:0% +bad it's not great either but like I +said with a thousand processors you can + + align:start position:0% +said with a thousand processors you can + + + align:start position:0% +said with a thousand processors you can +go from uh Nan to microsc so yeah that's + + align:start position:0% +go from uh Nan to microsc so yeah that's + + + align:start position:0% +go from uh Nan to microsc so yeah that's +not bad I mean you you can see that + + align:start position:0% +not bad I mean you you can see that + + + align:start position:0% +not bad I mean you you can see that +you're never going to make it to Second + + align:start position:0% +you're never going to make it to Second + + + align:start position:0% +you're never going to make it to Second +some okay because of the linear scale + + align:start position:0% +some okay because of the linear scale + + + align:start position:0% +some okay because of the linear scale +scaling but it is a sort of intermediate + + align:start position:0% +scaling but it is a sort of intermediate + + + align:start position:0% +scaling but it is a sort of intermediate +time scale that can be + + align:start position:0% +time scale that can be + + + align:start position:0% +time scale that can be +useful here's an example this is + + align:start position:0% +useful here's an example this is + + + align:start position:0% +useful here's an example this is +planarization uh of silver on Silver uh + + align:start position:0% +planarization uh of silver on Silver uh + + + align:start position:0% +planarization uh of silver on Silver uh +and this comes straight out of our + + align:start position:0% +and this comes straight out of our + + + align:start position:0% +and this comes straight out of our +voter's article um so essentially this + + align:start position:0% +voter's article um so essentially this + + + align:start position:0% +voter's article um so essentially this +is a a one one layer of silver that's + + align:start position:0% +is a a one one layer of silver that's + + + align:start position:0% +is a a one one layer of silver that's +the white atoms um and then on top of + + align:start position:0% +the white atoms um and then on top of + + + align:start position:0% +the white atoms um and then on top of +that is an a first layer which is the + + align:start position:0% +that is an a first layer which is the + + + align:start position:0% +that is an a first layer which is the +blue atoms and then the yellow atoms is + + align:start position:0% +blue atoms and then the yellow atoms is + + + align:start position:0% +blue atoms and then the yellow atoms is +another layer on top okay so you're + + align:start position:0% +another layer on top okay so you're + + + align:start position:0% +another layer on top okay so you're +seeing three layers and so this studies + + align:start position:0% +seeing three layers and so this studies + + + align:start position:0% +seeing three layers and so this studies +this study um tracks how the system + + align:start position:0% +this study um tracks how the system + + + align:start position:0% +this study um tracks how the system +planarizes to lower its surface energy + + align:start position:0% +planarizes to lower its surface energy + + + align:start position:0% +planarizes to lower its surface energy +so the top atoms should sort of come + + align:start position:0% +so the top atoms should sort of come + + + align:start position:0% +so the top atoms should sort of come +down and form all one + + align:start position:0% +down and form all one + + + align:start position:0% +down and form all one +Island and so this is perfect for + + align:start position:0% +Island and so this is perfect for + + + align:start position:0% +Island and so this is perfect for +Accelerated MD I mean you know + + align:start position:0% +Accelerated MD I mean you know + + + align:start position:0% +Accelerated MD I mean you know +researchers know why they pick problems + + align:start position:0% +researchers know why they pick problems + + + align:start position:0% +researchers know why they pick problems +because they can solve them um because + + align:start position:0% +because they can solve them um because + + + align:start position:0% +because they can solve them um because +this is a set of discrete events you + + align:start position:0% +this is a set of discrete events you + + + align:start position:0% +this is a set of discrete events you +know atoms diffuse and maybe even + + align:start position:0% +know atoms diffuse and maybe even + + + align:start position:0% +know atoms diffuse and maybe even +collectively you see the nice thing + + align:start position:0% +collectively you see the nice thing + + + align:start position:0% +collectively you see the nice thing +about it these that you're not imposing + + align:start position:0% +about it these that you're not imposing + + + align:start position:0% +about it these that you're not imposing +the kinetic mechanism but it's still a + + align:start position:0% +the kinetic mechanism but it's still a + + + align:start position:0% +the kinetic mechanism but it's still a +set of discrete events so you know atoms + + align:start position:0% +set of discrete events so you know atoms + + + align:start position:0% +set of discrete events so you know atoms +May hop a little you can see it in the + + align:start position:0% +May hop a little you can see it in the + + + align:start position:0% +May hop a little you can see it in the +first few slides there and ultimately + + align:start position:0% +first few slides there and ultimately + + + align:start position:0% +first few slides there and ultimately +sort of PL Ariz and you know people got + + align:start position:0% +sort of PL Ariz and you know people got + + + align:start position:0% +sort of PL Ariz and you know people got +all the way up to um one micro second uh + + align:start position:0% +all the way up to um one micro second uh + + + align:start position:0% +all the way up to um one micro second uh +although it was done with empirical + + align:start position:0% +although it was done with empirical + + + align:start position:0% +although it was done with empirical +potential so and according to Art voter + + align:start position:0% +potential so and according to Art voter + + + align:start position:0% +potential so and according to Art voter +this took only about 5 days on 32 + + align:start position:0% +this took only about 5 days on 32 + + + align:start position:0% +this took only about 5 days on 32 +pennium and these are all I mean these + + align:start position:0% +pennium and these are all I mean these + + + align:start position:0% +pennium and these are all I mean these +are 1 GHz pennium so probably do it in + + align:start position:0% +are 1 GHz pennium so probably do it in + + + align:start position:0% +are 1 GHz pennium so probably do it in +maybe you know 1 to two days + + align:start position:0% +maybe you know 1 to two days + + + align:start position:0% +maybe you know 1 to two days +now + + align:start position:0% +now + + + align:start position:0% +now +um I think you can already see if I go + + align:start position:0% +um I think you can already see if I go + + + align:start position:0% +um I think you can already see if I go +back um when this will not + + align:start position:0% +back um when this will not + + + align:start position:0% +back um when this will not +work um it this will not work if the + + align:start position:0% +work um it this will not work if the + + + align:start position:0% +work um it this will not work if the +overhead becomes excessive and how is it + + align:start position:0% +overhead becomes excessive and how is it + + + align:start position:0% +overhead becomes excessive and how is it +going to become + + align:start position:0% +going to become + + + align:start position:0% +going to become +excessive + + align:start position:0% +excessive + + + align:start position:0% +excessive +if if you start getting a lot of + + align:start position:0% +if if you start getting a lot of + + + align:start position:0% +if if you start getting a lot of +Transitions okay if only after a little + + align:start position:0% +Transitions okay if only after a little + + + align:start position:0% +Transitions okay if only after a little +bit of simulation you get a transition + + align:start position:0% +bit of simulation you get a transition + + + align:start position:0% +bit of simulation you get a transition +then you're over head starts to weigh + + align:start position:0% +then you're over head starts to weigh + + + align:start position:0% +then you're over head starts to weigh +heavily and when's that going to happen + + align:start position:0% +heavily and when's that going to happen + + + align:start position:0% +heavily and when's that going to happen +well it's going to happen of course when + + align:start position:0% +well it's going to happen of course when + + + align:start position:0% +well it's going to happen of course when +you have low activation barriers but + + align:start position:0% +you have low activation barriers but + + + align:start position:0% +you have low activation barriers but +there's another problem which is a + + align:start position:0% +there's another problem which is a + + + align:start position:0% +there's another problem which is a +little more severe if you make your + + align:start position:0% +little more severe if you make your + + + align:start position:0% +little more severe if you make your +system bigger and bigger see the + + align:start position:0% +system bigger and bigger see the + + + align:start position:0% +system bigger and bigger see the +probability let's say you have a system + + align:start position:0% +probability let's say you have a system + + + align:start position:0% +probability let's say you have a system +that's sort of locally identical if you + + align:start position:0% +that's sort of locally identical if you + + + align:start position:0% +that's sort of locally identical if you +make it bigger and + + align:start position:0% +make it bigger and + + + align:start position:0% +make it bigger and +bigger the the probability that a + + align:start position:0% +bigger the the probability that a + + + align:start position:0% +bigger the the probability that a +transition occurs let's see an atom + + align:start position:0% +transition occurs let's see an atom + + + align:start position:0% +transition occurs let's see an atom +diffuses is proportional to the system + + align:start position:0% +diffuses is proportional to the system + + + align:start position:0% +diffuses is proportional to the system +size the pro the probability that an + + align:start position:0% +size the pro the probability that an + + + align:start position:0% +size the pro the probability that an +event happens is is proportional to the + + align:start position:0% +event happens is is proportional to the + + + align:start position:0% +event happens is is proportional to the +system size so as you make the system + + align:start position:0% +system size so as you make the system + + + align:start position:0% +system size so as you make the system +bigger and bigger this essentially + + align:start position:0% +bigger and bigger this essentially + + + align:start position:0% +bigger and bigger this essentially +becomes less and less efficient okay + + align:start position:0% +becomes less and less efficient okay + + + align:start position:0% +becomes less and less efficient okay +because you get more and more + + align:start position:0% +because you get more and more + + + align:start position:0% +because you get more and more +transitions uh and that's something + + align:start position:0% +transitions uh and that's something + + + align:start position:0% +transitions uh and that's something +you'll see in other versions of + + align:start position:0% +you'll see in other versions of + + + align:start position:0% +you'll see in other versions of +accelerated uh MD as + + align:start position:0% +accelerated uh MD as + + + align:start position:0% +accelerated uh MD as +well okay hyper dynamics I like I like + + align:start position:0% +well okay hyper dynamics I like I like + + + align:start position:0% +well okay hyper dynamics I like I like +the word very much but I'm not going to + + align:start position:0% +the word very much but I'm not going to + + + align:start position:0% +the word very much but I'm not going to +say much about it um hyper dynamics is + + align:start position:0% +say much about it um hyper dynamics is + + + align:start position:0% +say much about it um hyper dynamics is +really a class of methods uh that is + + align:start position:0% +really a class of methods uh that is + + + align:start position:0% +really a class of methods uh that is +getting very popular not just in + + align:start position:0% +getting very popular not just in + + + align:start position:0% +getting very popular not just in +accelerating mdn but the whole idea of + + align:start position:0% +accelerating mdn but the whole idea of + + + align:start position:0% +accelerating mdn but the whole idea of +modifying the potential surface it's + + align:start position:0% +modifying the potential surface it's + + + align:start position:0% +modifying the potential surface it's +it's getting sort of very popular also + + align:start position:0% +it's getting sort of very popular also + + + align:start position:0% +it's getting sort of very popular also +for Pure optimization methods you know + + align:start position:0% +for Pure optimization methods you know + + + align:start position:0% +for Pure optimization methods you know +if you think that this + + align:start position:0% + + + + align:start position:0% + +is the surface of the original system + + align:start position:0% +is the surface of the original system + + + align:start position:0% +is the surface of the original system +this is the energy surface you know your + + align:start position:0% +this is the energy surface you know your + + + align:start position:0% +this is the energy surface you know your +problem is that these Wells are too deep + + align:start position:0% +problem is that these Wells are too deep + + + align:start position:0% +problem is that these Wells are too deep +well solve the problem by lifting them + + align:start position:0% +well solve the problem by lifting them + + + align:start position:0% +well solve the problem by lifting them +up so if you can define a potential that + + align:start position:0% + + + + align:start position:0% + +tracks the original potential in most of + + align:start position:0% +tracks the original potential in most of + + + align:start position:0% +tracks the original potential in most of +space especially deactivated pieces but + + align:start position:0% +space especially deactivated pieces but + + + align:start position:0% +space especially deactivated pieces but +then lifts up the minimum of the + + align:start position:0% + + + + align:start position:0% + +well if your system moves on the red + + align:start position:0% +well if your system moves on the red + + + align:start position:0% +well if your system moves on the red +potential it's going to transition a lot + + align:start position:0% +potential it's going to transition a lot + + + align:start position:0% +potential it's going to transition a lot +faster okay because the activation barer + + align:start position:0% +faster okay because the activation barer + + + align:start position:0% +faster okay because the activation barer +goes down a lot um and you can actually + + align:start position:0% +goes down a lot um and you can actually + + + align:start position:0% +goes down a lot um and you can actually +run the system on the red curve and + + align:start position:0% +run the system on the red curve and + + + align:start position:0% +run the system on the red curve and +correct for the transition rates cuz see + + align:start position:0% +correct for the transition rates cuz see + + + align:start position:0% +correct for the transition rates cuz see +the cool thing is that once + + align:start position:0% +the cool thing is that once + + + align:start position:0% +the cool thing is that once +the MD finds the + + align:start position:0% +the MD finds the + + + align:start position:0% +the MD finds the +Transitions okay so you know MD is like + + align:start position:0% +Transitions okay so you know MD is like + + + align:start position:0% +Transitions okay so you know MD is like +going back and forth here but once it's + + align:start position:0% +going back and forth here but once it's + + + align:start position:0% +going back and forth here but once it's +found the transition you could calculate + + align:start position:0% +found the transition you could calculate + + + align:start position:0% +found the transition you could calculate +back what the real barrier should have + + align:start position:0% +back what the real barrier should have + + + align:start position:0% +back what the real barrier should have +been okay so you know at what rate the + + align:start position:0% +been okay so you know at what rate the + + + align:start position:0% +been okay so you know at what rate the +system should have + + align:start position:0% +system should have + + + align:start position:0% +system should have +transitioned okay so boosting the + + align:start position:0% +transitioned okay so boosting the + + + align:start position:0% +transitioned okay so boosting the +potential surface with this boost + + align:start position:0% +potential surface with this boost + + + align:start position:0% +potential surface with this boost +potential that's this difference here + + align:start position:0% +potential that's this difference here + + + align:start position:0% +potential that's this difference here +boosting it up is essentially you know + + align:start position:0% +boosting it up is essentially you know + + + align:start position:0% +boosting it up is essentially you know +accelerating the escape from the minimum + + align:start position:0% +accelerating the escape from the minimum + + + align:start position:0% +accelerating the escape from the minimum +okay and you can correct back by this + + align:start position:0% +okay and you can correct back by this + + + align:start position:0% +okay and you can correct back by this +boltzman factor which is essentially the + + align:start position:0% +boltzman factor which is essentially the + + + align:start position:0% +boltzman factor which is essentially the +the comes from the ratio of of the + + align:start position:0% +the comes from the ratio of of the + + + align:start position:0% +the comes from the ratio of of the +proper rate to the rate that you + + align:start position:0% +proper rate to the rate that you + + + align:start position:0% +proper rate to the rate that you +actually had in your ND simulation + + align:start position:0% +actually had in your ND simulation + + + align:start position:0% +actually had in your ND simulation +there's all kinds of Tricks involved + + align:start position:0% +there's all kinds of Tricks involved + + + align:start position:0% +there's all kinds of Tricks involved +this is a simplified version of it um + + align:start position:0% +this is a simplified version of it um + + + align:start position:0% +this is a simplified version of it um +like there's a lot of questions about + + align:start position:0% +like there's a lot of questions about + + + align:start position:0% +like there's a lot of questions about +how you define that boost surface uh for + + align:start position:0% +how you define that boost surface uh for + + + align:start position:0% +how you define that boost surface uh for +example do you want to keep the same + + align:start position:0% +example do you want to keep the same + + + align:start position:0% +example do you want to keep the same +frequencies so then you'd like to keep + + align:start position:0% +frequencies so then you'd like to keep + + + align:start position:0% +frequencies so then you'd like to keep +the curvature the same uh because then + + align:start position:0% +the curvature the same uh because then + + + align:start position:0% +the curvature the same uh because then +you keep the same attempt frequencies + + align:start position:0% +you keep the same attempt frequencies + + + align:start position:0% +you keep the same attempt frequencies +but you're only changing the the success + + align:start position:0% +but you're only changing the the success + + + align:start position:0% +but you're only changing the the success +rate of crossing the barrier that's a + + align:start position:0% +rate of crossing the barrier that's a + + + align:start position:0% +rate of crossing the barrier that's a +very elegant way of doing and people + + align:start position:0% +very elegant way of doing and people + + + align:start position:0% +very elegant way of doing and people +have ways that they can do this um + + align:start position:0% +have ways that they can do this um + + + align:start position:0% +have ways that they can do this um +so doing this in + + align:start position:0% +so doing this in + + + align:start position:0% +so doing this in +practice um often means calculating um + + align:start position:0% +practice um often means calculating um + + + align:start position:0% +practice um often means calculating um +derivatives of potential surfaces in + + align:start position:0% +derivatives of potential surfaces in + + + align:start position:0% +derivatives of potential surfaces in +many cases even H so matrices of second + + align:start position:0% +many cases even H so matrices of second + + + align:start position:0% +many cases even H so matrices of second +derivatives and that's easy to do when + + align:start position:0% +derivatives and that's easy to do when + + + align:start position:0% +derivatives and that's easy to do when +you have potentials it's a lot harder to + + align:start position:0% +you have potentials it's a lot harder to + + + align:start position:0% +you have potentials it's a lot harder to +do when you're doing quantum mechanics + + align:start position:0% +do when you're doing quantum mechanics + + + align:start position:0% +do when you're doing quantum mechanics +and so this again one of these things + + align:start position:0% +and so this again one of these things + + + align:start position:0% +and so this again one of these things +that is usually only done with empirical + + align:start position:0% +that is usually only done with empirical + + + align:start position:0% +that is usually only done with empirical +potentials uh actually I don't know of + + align:start position:0% +potentials uh actually I don't know of + + + align:start position:0% +potentials uh actually I don't know of +any implementation with Quanto mechanics + + align:start position:0% +any implementation with Quanto mechanics + + + align:start position:0% +any implementation with Quanto mechanics +but I it may be something I've just + + align:start position:0% +but I it may be something I've just + + + align:start position:0% +but I it may be something I've just +missed in the literature um this is used + + align:start position:0% +missed in the literature um this is used + + + align:start position:0% +missed in the literature um this is used +for sort of other schemes as well if you + + align:start position:0% +for sort of other schemes as well if you + + + align:start position:0% +for sort of other schemes as well if you +for a second don't care about Dynamics + + align:start position:0% +for a second don't care about Dynamics + + + align:start position:0% +for a second don't care about Dynamics +there are not schemes out there to use + + align:start position:0% +there are not schemes out there to use + + + align:start position:0% +there are not schemes out there to use +this for + + align:start position:0% +this for + + + align:start position:0% +this for +optimization you know if you think of + + align:start position:0% +optimization you know if you think of + + + align:start position:0% +optimization you know if you think of +global optimization of a system is a big + + align:start position:0% +global optimization of a system is a big + + + align:start position:0% +global optimization of a system is a big +problem because there's all kinds of + + align:start position:0% +problem because there's all kinds of + + + align:start position:0% +problem because there's all kinds of +local Wells well what you can do is if + + align:start position:0% +local Wells well what you can do is if + + + align:start position:0% +local Wells well what you can do is if +you fall in a well you essentially start + + align:start position:0% +you fall in a well you essentially start + + + align:start position:0% +you fall in a well you essentially start +filling up the + + align:start position:0% + + + + align:start position:0% + +well until you until it's sort of like + + align:start position:0% +well until you until it's sort of like + + + align:start position:0% +well until you until it's sort of like +water filling up the well until you fall + + align:start position:0% +water filling up the well until you fall + + + align:start position:0% +water filling up the well until you fall +out into the next well okay and then you + + align:start position:0% +out into the next well okay and then you + + + align:start position:0% +out into the next well okay and then you +start filling up that + + align:start position:0% + + + + align:start position:0% + +well till you fall in the next well and + + align:start position:0% +well till you fall in the next well and + + + align:start position:0% +well till you fall in the next well and +it's sort of like water cascading down + + align:start position:0% +it's sort of like water cascading down + + + align:start position:0% +it's sort of like water cascading down +an energy surface and it's a way to do + + align:start position:0% +an energy surface and it's a way to do + + + align:start position:0% +an energy surface and it's a way to do +Global optimization ation in a in a + + align:start position:0% +Global optimization ation in a in a + + + align:start position:0% +Global optimization ation in a in a +landscape of many minim and I think this + + align:start position:0% +landscape of many minim and I think this + + + align:start position:0% +landscape of many minim and I think this +method was developed by uh people at + + align:start position:0% +method was developed by uh people at + + + align:start position:0% +method was developed by uh people at +Princeton + + align:start position:0% + + + + align:start position:0% + +um so that's sort of in the category of + + align:start position:0% +um so that's sort of in the category of + + + align:start position:0% +um so that's sort of in the category of +hyper dynamics + + align:start position:0% +hyper dynamics + + + align:start position:0% +hyper dynamics +um the one that's actually very + + align:start position:0% +um the one that's actually very + + + align:start position:0% +um the one that's actually very +practical is the next one um which is + + align:start position:0% +practical is the next one um which is + + + align:start position:0% +practical is the next one um which is +temperature accelerated + + align:start position:0% + + + + align:start position:0% + +Dynamics which is again a sort of + + align:start position:0% +Dynamics which is again a sort of + + + align:start position:0% +Dynamics which is again a sort of +obvious idea you know if stuff runs too + + align:start position:0% +obvious idea you know if stuff runs too + + + align:start position:0% +obvious idea you know if stuff runs too +slow at low temperature run it at higher + + align:start position:0% +slow at low temperature run it at higher + + + align:start position:0% +slow at low temperature run it at higher +temperature and will go faster um that's + + align:start position:0% +temperature and will go faster um that's + + + align:start position:0% +temperature and will go faster um that's +actually something people have often + + align:start position:0% +actually something people have often + + + align:start position:0% +actually something people have often +done inmd without much + + align:start position:0% +done inmd without much + + + align:start position:0% +done inmd without much +justification uh what art voters group + + align:start position:0% +justification uh what art voters group + + + align:start position:0% +justification uh what art voters group +did in Los Al is essentially give this a + + align:start position:0% +did in Los Al is essentially give this a + + + align:start position:0% +did in Los Al is essentially give this a +justification and show how you can + + align:start position:0% +justification and show how you can + + + align:start position:0% +justification and show how you can +correct for that temperature difference + + align:start position:0% +correct for that temperature difference + + + align:start position:0% +correct for that temperature difference +between where you would like the result + + align:start position:0% +between where you would like the result + + + align:start position:0% +between where you would like the result +and where you're actually simulating um + + align:start position:0% +and where you're actually simulating um + + + align:start position:0% +and where you're actually simulating um +and so the idea of Tad as it's called is + + align:start position:0% +and so the idea of Tad as it's called is + + + align:start position:0% +and so the idea of Tad as it's called is +to uh use the high temperature to find + + align:start position:0% +to uh use the high temperature to find + + + align:start position:0% +to uh use the high temperature to find +the + + align:start position:0% +the + + + align:start position:0% +the +transitions but then execute them with + + align:start position:0% +transitions but then execute them with + + + align:start position:0% +transitions but then execute them with +the proper rate of the low + + align:start position:0% +the proper rate of the low + + + align:start position:0% +the proper rate of the low +temperature okay so essentially you run + + align:start position:0% +temperature okay so essentially you run + + + align:start position:0% +temperature okay so essentially you run +at high temperature so you sort of + + align:start position:0% +at high temperature so you sort of + + + align:start position:0% +at high temperature so you sort of +fairly quickly scan the potential + + align:start position:0% +fairly quickly scan the potential + + + align:start position:0% +fairly quickly scan the potential +surface and that tells you what the + + align:start position:0% +surface and that tells you what the + + + align:start position:0% +surface and that tells you what the +transitions are and then you go back to + + align:start position:0% +transitions are and then you go back to + + + align:start position:0% +transitions are and then you go back to +the low temperature and you do a sort of + + align:start position:0% +the low temperature and you do a sort of + + + align:start position:0% +the low temperature and you do a sort of +statistical mechanics a kind of kinetic + + align:start position:0% +statistical mechanics a kind of kinetic + + + align:start position:0% +statistical mechanics a kind of kinetic +Monte Carlo scheme or a um a transition + + align:start position:0% +Monte Carlo scheme or a um a transition + + + align:start position:0% +Monte Carlo scheme or a um a transition +state Theory approach and and execute + + align:start position:0% +state Theory approach and and execute + + + align:start position:0% +state Theory approach and and execute +the transitions so uh I'll show you an + + align:start position:0% +the transitions so uh I'll show you an + + + align:start position:0% +the transitions so uh I'll show you an +example um the idea is that you run at + + align:start position:0% +example um the idea is that you run at + + + align:start position:0% +example um the idea is that you run at +high temperature until a transition + + align:start position:0% +high temperature until a transition + + + align:start position:0% +high temperature until a transition +occurs once you find the transition it's + + align:start position:0% +occurs once you find the transition it's + + + align:start position:0% +occurs once you find the transition it's +a trivial matter of finding the + + align:start position:0% +a trivial matter of finding the + + + align:start position:0% +a trivial matter of finding the +activation barrier okay um then you + + align:start position:0% +activation barrier okay um then you + + + align:start position:0% +activation barrier okay um then you +reverse the transition and you run again + + align:start position:0% +reverse the transition and you run again + + + align:start position:0% +reverse the transition and you run again +at high temperature and the idea is that + + align:start position:0% +at high temperature and the idea is that + + + align:start position:0% +at high temperature and the idea is that +you get this catalog of transitions so + + align:start position:0% +you get this catalog of transitions so + + + align:start position:0% +you get this catalog of transitions so +you get this catalog of possible + + align:start position:0% +you get this catalog of possible + + + align:start position:0% +you get this catalog of possible +transitions now why do you need more + + align:start position:0% +transitions now why do you need more + + + align:start position:0% +transitions now why do you need more +than one you say well the reason is that + + align:start position:0% +than one you say well the reason is that + + + align:start position:0% +than one you say well the reason is that +the one you find at high temperature May + + align:start position:0% +the one you find at high temperature May + + + align:start position:0% +the one you find at high temperature May +not be the one that actually gets + + align:start position:0% +not be the one that actually gets + + + align:start position:0% +not be the one that actually gets +executed at low temperature if they have + + align:start position:0% +executed at low temperature if they have + + + align:start position:0% +executed at low temperature if they have +different activation barriers then their + + align:start position:0% +different activation barriers then their + + + align:start position:0% +different activation barriers then their +rates may cross with + + align:start position:0% +rates may cross with + + + align:start position:0% +rates may cross with +temperature + + align:start position:0% + + + + align:start position:0% + +um here's an example if I show The + + align:start position:0% +um here's an example if I show The + + + align:start position:0% +um here's an example if I show The +Crossing + + align:start position:0% +Crossing + + + align:start position:0% +Crossing +rate okay versus 1 overt let's say you + + align:start position:0% +rate okay versus 1 overt let's say you + + + align:start position:0% +rate okay versus 1 overt let's say you +run at high temperature uh you know if + + align:start position:0% +run at high temperature uh you know if + + + align:start position:0% +run at high temperature uh you know if +these behave arenus then their Crossing + + align:start position:0% +these behave arenus then their Crossing + + + align:start position:0% +these behave arenus then their Crossing +rate which is one one over the time you + + align:start position:0% +rate which is one one over the time you + + + align:start position:0% +rate which is one one over the time you +have to wait goes like 1 over T um you + + align:start position:0% +have to wait goes like 1 over T um you + + + align:start position:0% +have to wait goes like 1 over T um you +may find one that has a high Crossing + + align:start position:0% +may find one that has a high Crossing + + + align:start position:0% +may find one that has a high Crossing +rate at high + + align:start position:0% +rate at high + + + align:start position:0% +rate at high +temperature and one and this one that + + align:start position:0% +temperature and one and this one that + + + align:start position:0% +temperature and one and this one that +has a a lower Crossing rate at high + + align:start position:0% +has a a lower Crossing rate at high + + + align:start position:0% +has a a lower Crossing rate at high +temperature but if they have a different + + align:start position:0% +temperature but if they have a different + + + align:start position:0% +temperature but if they have a different +activation barrier they'll extrapolate + + align:start position:0% +activation barrier they'll extrapolate + + + align:start position:0% +activation barrier they'll extrapolate +differently to low temperature what you + + align:start position:0% +differently to low temperature what you + + + align:start position:0% +differently to low temperature what you +see now at low + + align:start position:0% +see now at low + + + align:start position:0% +see now at low +temperature okay the one with the high + + align:start position:0% +temperature okay the one with the high + + + align:start position:0% +temperature okay the one with the high +rate at high temperature has the lower + + align:start position:0% +rate at high temperature has the lower + + + align:start position:0% +rate at high temperature has the lower +rate at low temperature okay so because + + align:start position:0% +rate at low temperature okay so because + + + align:start position:0% +rate at low temperature okay so because +transition have different activation + + align:start position:0% +transition have different activation + + + align:start position:0% +transition have different activation +barriers they may not be in the same + + align:start position:0% +barriers they may not be in the same + + + align:start position:0% +barriers they may not be in the same +order the sort of same frequency the + + align:start position:0% +order the sort of same frequency the + + + align:start position:0% +order the sort of same frequency the +same rate at different + + align:start position:0% +same rate at different + + + align:start position:0% +same rate at different +temperatures and that's why you need a + + align:start position:0% +temperatures and that's why you need a + + + align:start position:0% +temperatures and that's why you need a +catalog of them you essentially need a + + align:start position:0% + + + + align:start position:0% + +window + + align:start position:0% +window + + + align:start position:0% +window +okay of rates of transition rates that + + align:start position:0% +okay of rates of transition rates that + + + align:start position:0% +okay of rates of transition rates that +give you a certain certainty that at the + + align:start position:0% +give you a certain certainty that at the + + + align:start position:0% +give you a certain certainty that at the +lower temperature you found the lowest + + align:start position:0% +lower temperature you found the lowest + + + align:start position:0% +lower temperature you found the lowest +one and you can kind of do back of the + + align:start position:0% +one and you can kind of do back of the + + + align:start position:0% +one and you can kind of do back of the +envelope calculation + + align:start position:0% +envelope calculation + + + align:start position:0% +envelope calculation +if you um make some assumptions about + + align:start position:0% +if you um make some assumptions about + + + align:start position:0% +if you um make some assumptions about +the range in which your EAS your + + align:start position:0% +the range in which your EAS your + + + align:start position:0% +the range in which your EAS your +activation barrier can vary then you + + align:start position:0% +activation barrier can vary then you + + + align:start position:0% +activation barrier can vary then you +know the range of slopes of these arous + + align:start position:0% +know the range of slopes of these arous + + + align:start position:0% +know the range of slopes of these arous +walls okay so that can tell you a little + + align:start position:0% +walls okay so that can tell you a little + + + align:start position:0% +walls okay so that can tell you a little +bit about how long you should be running + + align:start position:0% +bit about how long you should be running + + + align:start position:0% +bit about how long you should be running +okay uh at the high temperature to make + + align:start position:0% +okay uh at the high temperature to make + + + align:start position:0% +okay uh at the high temperature to make +sure you you found all the transitions + + align:start position:0% +sure you you found all the transitions + + + align:start position:0% +sure you you found all the transitions +or are likely to have found all the + + align:start position:0% +or are likely to have found all the + + + align:start position:0% +or are likely to have found all the +transitions that get executed at the low + + align:start position:0% +transitions that get executed at the low + + + align:start position:0% +transitions that get executed at the low +temperature so as everybody see the idea + + align:start position:0% +temperature so as everybody see the idea + + + align:start position:0% +temperature so as everybody see the idea +you're essentially using + + align:start position:0% +you're essentially using + + + align:start position:0% +you're essentially using +uh molecular Dynamics as a way of + + align:start position:0% +uh molecular Dynamics as a way of + + + align:start position:0% +uh molecular Dynamics as a way of +finding Transitions okay and that's the + + align:start position:0% +finding Transitions okay and that's the + + + align:start position:0% +finding Transitions okay and that's the +hard problem in any kinetic problem it's + + align:start position:0% +hard problem in any kinetic problem it's + + + align:start position:0% +hard problem in any kinetic problem it's +finding the transitions once you find + + align:start position:0% +finding the transitions once you find + + + align:start position:0% +finding the transitions once you find +them you know you can calculate their + + align:start position:0% +them you know you can calculate their + + + align:start position:0% +them you know you can calculate their +activation barrier and you can execute + + align:start position:0% +activation barrier and you can execute + + + align:start position:0% +activation barrier and you can execute +them with you know standard rate + + align:start position:0% +them with you know standard rate + + + align:start position:0% +them with you know standard rate +constant Theory but it's finding them + + align:start position:0% +constant Theory but it's finding them + + + align:start position:0% +constant Theory but it's finding them +and MD because it's unbiased is great um + + align:start position:0% +and MD because it's unbiased is great um + + + align:start position:0% +and MD because it's unbiased is great um +at doing that + + align:start position:0% + + + + align:start position:0% + +okay so the approximations of the method + + align:start position:0% +okay so the approximations of the method + + + align:start position:0% +okay so the approximations of the method +are fairly obvious um to do this + + align:start position:0% +are fairly obvious um to do this + + + align:start position:0% +are fairly obvious um to do this +extrapolation you assume harmonic + + align:start position:0% +extrapolation you assume harmonic + + + align:start position:0% +extrapolation you assume harmonic +transition state Theory so you + + align:start position:0% +transition state Theory so you + + + align:start position:0% +transition state Theory so you +essentially assume that you have a + + align:start position:0% +essentially assume that you have a + + + align:start position:0% +essentially assume that you have a +simple arenus extrapolation between + + align:start position:0% +simple arenus extrapolation between + + + align:start position:0% +simple arenus extrapolation between +temperature so that the pre-exponential + + align:start position:0% +temperature so that the pre-exponential + + + align:start position:0% +temperature so that the pre-exponential +factor is constant um and well like I + + align:start position:0% +factor is constant um and well like I + + + align:start position:0% +factor is constant um and well like I +said before you have to make sure that + + align:start position:0% +said before you have to make sure that + + + align:start position:0% +said before you have to make sure that +you found all the mechanisms at that you + + align:start position:0% +you found all the mechanisms at that you + + + align:start position:0% +you found all the mechanisms at that you +found enough mechanisms at high + + align:start position:0% +found enough mechanisms at high + + + align:start position:0% +found enough mechanisms at high +temperature show you definitely have the + + align:start position:0% +temperature show you definitely have the + + + align:start position:0% +temperature show you definitely have the +low the fastest one um at low + + align:start position:0% + + + + align:start position:0% + +temperature okay you know and here's + + align:start position:0% +temperature okay you know and here's + + + align:start position:0% +temperature okay you know and here's +another application out of uh art + + align:start position:0% +another application out of uh art + + + align:start position:0% +another application out of uh art +voter's work uh this is copper on copper + + align:start position:0% +voter's work uh this is copper on copper + + + align:start position:0% +voter's work uh this is copper on copper +deposition um so they literally I think + + align:start position:0% +deposition um so they literally I think + + + align:start position:0% +deposition um so they literally I think +add atoms to a surface and then + + align:start position:0% +add atoms to a surface and then + + + align:start position:0% +add atoms to a surface and then +equilibrate them um and you know they + + align:start position:0% +equilibrate them um and you know they + + + align:start position:0% +equilibrate them um and you know they +run so they do direct MD for two P + + align:start position:0% +run so they do direct MD for two P + + + align:start position:0% +run so they do direct MD for two P +seconds that's how they deposit the atom + + align:start position:0% +seconds that's how they deposit the atom + + + align:start position:0% +seconds that's how they deposit the atom +but then then uh run you know 3 seconds + + align:start position:0% +but then then uh run you know 3 seconds + + + align:start position:0% +but then then uh run you know 3 seconds +of intervening time with uh Tad uh now + + align:start position:0% +of intervening time with uh Tad uh now + + + align:start position:0% +of intervening time with uh Tad uh now +you may think you know 3 seconds that's + + align:start position:0% +you may think you know 3 seconds that's + + + align:start position:0% +you may think you know 3 seconds that's +a lot well it's not because you're + + align:start position:0% +a lot well it's not because you're + + + align:start position:0% +a lot well it's not because you're +really doing transition state Theory um + + align:start position:0% +really doing transition state Theory um + + + align:start position:0% +really doing transition state Theory um +if I have barriers of one electron volt + + align:start position:0% +if I have barriers of one electron volt + + + align:start position:0% +if I have barriers of one electron volt +okay then pretty much at room + + align:start position:0% +okay then pretty much at room + + + align:start position:0% +okay then pretty much at room +temperature one electron volt that tends + + align:start position:0% +temperature one electron volt that tends + + + align:start position:0% +temperature one electron volt that tends +to give you rates around one per second + + align:start position:0% +to give you rates around one per second + + + align:start position:0% +to give you rates around one per second +that's kind of the time scale so if you + + align:start position:0% +that's kind of the time scale so if you + + + align:start position:0% +that's kind of the time scale so if you +have barriers of one electron volt then + + align:start position:0% +have barriers of one electron volt then + + + align:start position:0% +have barriers of one electron volt then +every time you execute a step you're 1 + + align:start position:0% +every time you execute a step you're 1 + + + align:start position:0% +every time you execute a step you're 1 +second further on average so the 3 + + align:start position:0% +second further on average so the 3 + + + align:start position:0% +second further on average so the 3 +seconds is in that sense not that + + align:start position:0% +seconds is in that sense not that + + + align:start position:0% +seconds is in that sense not that +impressive you know I can do a thousand + + align:start position:0% +impressive you know I can do a thousand + + + align:start position:0% +impressive you know I can do a thousand +seconds with one step just by having a + + align:start position:0% +seconds with one step just by having a + + + align:start position:0% +seconds with one step just by having a +system with a very high activation + + align:start position:0% + + + + align:start position:0% + +barrier okay um you can look at the + + align:start position:0% +barrier okay um you can look at the + + + align:start position:0% +barrier okay um you can look at the +different events in the simulation and + + align:start position:0% +different events in the simulation and + + + align:start position:0% +different events in the simulation and +one of the nice things is because you're + + align:start position:0% +one of the nice things is because you're + + + align:start position:0% +one of the nice things is because you're +doing MD um your your system is + + align:start position:0% +doing MD um your your system is + + + align:start position:0% +doing MD um your your system is +unbiased and you know one we've learned + + align:start position:0% +unbiased and you know one we've learned + + + align:start position:0% +unbiased and you know one we've learned +more and more by doing MD on surfaces is + + align:start position:0% +more and more by doing MD on surfaces is + + + align:start position:0% +more and more by doing MD on surfaces is +that um the diffusive processes are not + + align:start position:0% +that um the diffusive processes are not + + + align:start position:0% +that um the diffusive processes are not +at all the way people thought they were + + align:start position:0% +at all the way people thought they were + + + align:start position:0% +at all the way people thought they were +people think of atoms hopping by + + align:start position:0% +people think of atoms hopping by + + + align:start position:0% +people think of atoms hopping by +themselves but because surfaces have so + + align:start position:0% +themselves but because surfaces have so + + + align:start position:0% +themselves but because surfaces have so +much open space of such low symmetry you + + align:start position:0% +much open space of such low symmetry you + + + align:start position:0% +much open space of such low symmetry you +see a lot of collectic Behavior Uh for + + align:start position:0% +see a lot of collectic Behavior Uh for + + + align:start position:0% +see a lot of collectic Behavior Uh for +example here's one um this this blue + + align:start position:0% +example here's one um this this blue + + + align:start position:0% +example here's one um this this blue +atom here um pushes in the surface + + align:start position:0% +atom here um pushes in the surface + + + align:start position:0% +atom here um pushes in the surface +pushing that um + + align:start position:0% +pushing that um + + + align:start position:0% +pushing that um +um uh orange at them or kind of what is + + align:start position:0% +um uh orange at them or kind of what is + + + align:start position:0% +um uh orange at them or kind of what is +it brown and that pushes then these two + + align:start position:0% +it brown and that pushes then these two + + + align:start position:0% +it brown and that pushes then these two +out and that's all one Collective event + + align:start position:0% +out and that's all one Collective event + + + align:start position:0% +out and that's all one Collective event +okay so these are not things you would + + align:start position:0% +okay so these are not things you would + + + align:start position:0% +okay so these are not things you would +easily guess + + align:start position:0% +easily guess + + + align:start position:0% +easily guess +at um here's another Collective event of + + align:start position:0% +at um here's another Collective event of + + + align:start position:0% +at um here's another Collective event of +sort of a kind of um row of atoms three + + align:start position:0% +sort of a kind of um row of atoms three + + + align:start position:0% +sort of a kind of um row of atoms three +at a time at a step Edge essentially + + align:start position:0% +at a time at a step Edge essentially + + + align:start position:0% +at a time at a step Edge essentially +kind of moving down + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so you you you typically need MD methods + + align:start position:0% +so you you you typically need MD methods + + + align:start position:0% +so you you you typically need MD methods +um whenever you don't know or you're not + + align:start position:0% +um whenever you don't know or you're not + + + align:start position:0% +um whenever you don't know or you're not +absolutely sure what the transition + + align:start position:0% +absolutely sure what the transition + + + align:start position:0% +absolutely sure what the transition +mechanisms are if you know what the + + align:start position:0% +mechanisms are if you know what the + + + align:start position:0% +mechanisms are if you know what the +transition mechanisms are then it tends + + align:start position:0% +transition mechanisms are then it tends + + + align:start position:0% +transition mechanisms are then it tends +to be much more efficient to do Mont + + align:start position:0% +to be much more efficient to do Mont + + + align:start position:0% +to be much more efficient to do Mont +Carlo okay you can set up kinetic Monte + + align:start position:0% +Carlo okay you can set up kinetic Monte + + + align:start position:0% +Carlo okay you can set up kinetic Monte +Carlo schemes um that execute + + align:start position:0% +Carlo schemes um that execute + + + align:start position:0% +Carlo schemes um that execute +transitions with the right uh transfer + + align:start position:0% +transitions with the right uh transfer + + + align:start position:0% +transitions with the right uh transfer +it's just that you have to know what + + align:start position:0% +it's just that you have to know what + + + align:start position:0% +it's just that you have to know what +those transitions are so you've already + + align:start position:0% +those transitions are so you've already + + + align:start position:0% +those transitions are so you've already +done Monte Carlo and lce models but we + + align:start position:0% +done Monte Carlo and lce models but we + + + align:start position:0% +done Monte Carlo and lce models but we +saw it as a sampling method um you could + + align:start position:0% +saw it as a sampling method um you could + + + align:start position:0% +saw it as a sampling method um you could +also now see it as a kinetic method you + + align:start position:0% +also now see it as a kinetic method you + + + align:start position:0% +also now see it as a kinetic method you +know let's say you have a latus of + + align:start position:0% +know let's say you have a latus of + + + align:start position:0% +know let's say you have a latus of +atoms let's make it easier even atoms + + align:start position:0% +atoms let's make it easier even atoms + + + align:start position:0% +atoms let's make it easier even atoms +and + + align:start position:0% +and + + + align:start position:0% +and +vacancies you + + align:start position:0% +vacancies you + + + align:start position:0% +vacancies you +know so we've shown you how to do the + + align:start position:0% +know so we've shown you how to do the + + + align:start position:0% +know so we've shown you how to do the +thermodynamics well let's say you want + + align:start position:0% +thermodynamics well let's say you want + + + align:start position:0% +thermodynamics well let's say you want +to study + + align:start position:0% +to study + + + align:start position:0% +to study +diffusion if you know microscopically + + align:start position:0% +diffusion if you know microscopically + + + align:start position:0% +diffusion if you know microscopically +how this atom would migrate to there + + align:start position:0% +how this atom would migrate to there + + + align:start position:0% +how this atom would migrate to there +through which path it would do that then + + align:start position:0% +through which path it would do that then + + + align:start position:0% +through which path it would do that then +you just calculate the energy along that + + align:start position:0% +you just calculate the energy along that + + + align:start position:0% +you just calculate the energy along that +path and you can now do a mon Carlo + + align:start position:0% +path and you can now do a mon Carlo + + + align:start position:0% +path and you can now do a mon Carlo +where the way you travel through face + + align:start position:0% +where the way you travel through face + + + align:start position:0% +where the way you travel through face +space is by a a real kinetic mechanism + + align:start position:0% +space is by a a real kinetic mechanism + + + align:start position:0% +space is by a a real kinetic mechanism +okay so you could not take your exchange + + align:start position:0% +okay so you could not take your exchange + + + align:start position:0% +okay so you could not take your exchange +rate dependent not only on the energy of + + align:start position:0% +rate dependent not only on the energy of + + + align:start position:0% +rate dependent not only on the energy of +the initial and the final state which is + + align:start position:0% +the initial and the final state which is + + + align:start position:0% +the initial and the final state which is +the way we did it in the Metropolis + + align:start position:0% +the way we did it in the Metropolis + + + align:start position:0% +the way we did it in the Metropolis +algorithm but also have a preactor now + + align:start position:0% +algorithm but also have a preactor now + + + align:start position:0% +algorithm but also have a preactor now +that kinetic so that has a frequency + + align:start position:0% +that kinetic so that has a frequency + + + align:start position:0% +that kinetic so that has a frequency +times an activation barrier that's + + align:start position:0% +times an activation barrier that's + + + align:start position:0% +times an activation barrier that's +essentially kinetic mon Carlo okay but + + align:start position:0% +essentially kinetic mon Carlo okay but + + + align:start position:0% +essentially kinetic mon Carlo okay but +you see kinetic mon car implies that you + + align:start position:0% +you see kinetic mon car implies that you + + + align:start position:0% +you see kinetic mon car implies that you +know what your + + align:start position:0% +know what your + + + align:start position:0% +know what your +possible migration mechanisms are + + align:start position:0% +possible migration mechanisms are + + + align:start position:0% +possible migration mechanisms are +between states and usually um you know + + align:start position:0% +between states and usually um you know + + + align:start position:0% +between states and usually um you know +that reasonably well in things like + + align:start position:0% +that reasonably well in things like + + + align:start position:0% +that reasonably well in things like +crystalline solids so there kinetic + + align:start position:0% +crystalline solids so there kinetic + + + align:start position:0% +crystalline solids so there kinetic +monol is very applicable people also use + + align:start position:0% +monol is very applicable people also use + + + align:start position:0% +monol is very applicable people also use +it on surfaces even though it gets a + + align:start position:0% +it on surfaces even though it gets a + + + align:start position:0% +it on surfaces even though it gets a +little more dicey there um but once of + + align:start position:0% +little more dicey there um but once of + + + align:start position:0% +little more dicey there um but once of +course you go to sort of very disorted + + align:start position:0% +course you go to sort of very disorted + + + align:start position:0% +course you go to sort of very disorted +systems it it really gets way out of + + align:start position:0% +systems it it really gets way out of + + + align:start position:0% +systems it it really gets way out of +hand what the kinetic mechanisms are and + + align:start position:0% +hand what the kinetic mechanisms are and + + + align:start position:0% +hand what the kinetic mechanisms are and +this wouldn't work + + align:start position:0% +this wouldn't work + + + align:start position:0% +this wouldn't work +anymore so I was going to show you one + + align:start position:0% +anymore so I was going to show you one + + + align:start position:0% +anymore so I was going to show you one +example to sort of end up and um at a + + align:start position:0% +example to sort of end up and um at a + + + align:start position:0% +example to sort of end up and um at a +continuity I was going to take the same + + align:start position:0% +continuity I was going to take the same + + + align:start position:0% +continuity I was going to take the same +example that we did for the phase + + align:start position:0% +example that we did for the phase + + + align:start position:0% +example that we did for the phase +stability if you remember this uh when + + align:start position:0% +stability if you remember this uh when + + + align:start position:0% +stability if you remember this uh when +we talked about the cluster expansion we + + align:start position:0% +we talked about the cluster expansion we + + + align:start position:0% +we talked about the cluster expansion we +looked at the phase diagram of um + + align:start position:0% +looked at the phase diagram of um + + + align:start position:0% +looked at the phase diagram of um +lithium and lithium vacancies in lithium + + align:start position:0% +lithium and lithium vacancies in lithium + + + align:start position:0% +lithium and lithium vacancies in lithium +Coral oxide so remember the issue is + + align:start position:0% +Coral oxide so remember the issue is + + + align:start position:0% +Coral oxide so remember the issue is +that if you take lithium out + + align:start position:0% +that if you take lithium out + + + align:start position:0% +that if you take lithium out +you create vacancies there and and the + + align:start position:0% +you create vacancies there and and the + + + align:start position:0% +you create vacancies there and and the +issue was how do they organize and I + + align:start position:0% +issue was how do they organize and I + + + align:start position:0% +issue was how do they organize and I +showed you how to use a cluster + + align:start position:0% +showed you how to use a cluster + + + align:start position:0% +showed you how to use a cluster +expansion to do the phase AR and the + + align:start position:0% +expansion to do the phase AR and the + + + align:start position:0% +expansion to do the phase AR and the +thermodynamics of that let's say you + + align:start position:0% +thermodynamics of that let's say you + + + align:start position:0% +thermodynamics of that let's say you +want to worry about the kinetics so + + align:start position:0% +want to worry about the kinetics so + + + align:start position:0% +want to worry about the kinetics so +essentially how fast can you get that + + align:start position:0% +essentially how fast can you get that + + + align:start position:0% +essentially how fast can you get that +lithium in and out so you essentially + + align:start position:0% +lithium in and out so you essentially + + + align:start position:0% +lithium in and out so you essentially +want a diffusion constant in that + + align:start position:0% +want a diffusion constant in that + + + align:start position:0% +want a diffusion constant in that +material um well this is fairly well + + align:start position:0% +material um well this is fairly well + + + align:start position:0% +material um well this is fairly well +suited for kinetic Monte Carlo rather + + align:start position:0% +suited for kinetic Monte Carlo rather + + + align:start position:0% +suited for kinetic Monte Carlo rather +than molecular Dynamics first of all the + + align:start position:0% +than molecular Dynamics first of all the + + + align:start position:0% +than molecular Dynamics first of all the +rates are fairly slow so um doing + + align:start position:0% +rates are fairly slow so um doing + + + align:start position:0% +rates are fairly slow so um doing +anything with transition state theory is + + align:start position:0% +anything with transition state theory is + + + align:start position:0% +anything with transition state theory is +going to help you a lot uh and it's um + + align:start position:0% +going to help you a lot uh and it's um + + + align:start position:0% +going to help you a lot uh and it's um +you you have transitions between + + align:start position:0% +you you have transitions between + + + align:start position:0% +you you have transitions between +welldefined positions you know the atoms + + align:start position:0% +welldefined positions you know the atoms + + + align:start position:0% +welldefined positions you know the atoms +go from one well-defined side to another + + align:start position:0% +go from one well-defined side to another + + + align:start position:0% +go from one well-defined side to another +side + + align:start position:0% + + + + align:start position:0% + +um so + + align:start position:0% + + + + align:start position:0% + +um if you had dute diffusion uh you + + align:start position:0% +um if you had dute diffusion uh you + + + align:start position:0% +um if you had dute diffusion uh you +could just use random walk Theory so in + + align:start position:0% +could just use random walk Theory so in + + + align:start position:0% +could just use random walk Theory so in +that case diffusion is sort of trivial + + align:start position:0% +that case diffusion is sort of trivial + + + align:start position:0% +that case diffusion is sort of trivial +all you need is an activation barrier + + align:start position:0% +all you need is an activation barrier + + + align:start position:0% +all you need is an activation barrier +and a preactor all the rest you know you + + align:start position:0% +and a preactor all the rest you know you + + + align:start position:0% +and a preactor all the rest you know you +have the lce constant which is actually + + align:start position:0% +have the lce constant which is actually + + + align:start position:0% +have the lce constant which is actually +the jump link and you have the geometric + + align:start position:0% +the jump link and you have the geometric + + + align:start position:0% +the jump link and you have the geometric +correlation Factor these are all known + + align:start position:0% +correlation Factor these are all known + + + align:start position:0% +correlation Factor these are all known +the things in green you would have to + + align:start position:0% +the things in green you would have to + + + align:start position:0% +the things in green you would have to +calculate but that's two calculation + + align:start position:0% +calculate but that's two calculation + + + align:start position:0% +calculate but that's two calculation +random walks only apply when you have + + align:start position:0% +random walks only apply when you have + + + align:start position:0% +random walks only apply when you have +dilute diffusion what I mean with dilute + + align:start position:0% +dilute diffusion what I mean with dilute + + + align:start position:0% +dilute diffusion what I mean with dilute +diffusion um it's when the carrier of + + align:start position:0% +diffusion um it's when the carrier of + + + align:start position:0% +diffusion um it's when the carrier of +diffusion is very dilute so it doesn't + + align:start position:0% +diffusion is very dilute so it doesn't + + + align:start position:0% +diffusion is very dilute so it doesn't +interact um uh with itself so if you + + align:start position:0% +interact um uh with itself so if you + + + align:start position:0% +interact um uh with itself so if you +have substitutional diffusion with very + + align:start position:0% +have substitutional diffusion with very + + + align:start position:0% +have substitutional diffusion with very +dilute vacancy concentration then this + + align:start position:0% +dilute vacancy concentration then this + + + align:start position:0% +dilute vacancy concentration then this +would apply um the problem of course + + align:start position:0% +would apply um the problem of course + + + align:start position:0% +would apply um the problem of course +that we're going to look at the lithium + + align:start position:0% +that we're going to look at the lithium + + + align:start position:0% +that we're going to look at the lithium +Cobalt waxin is by definition not dilute + + align:start position:0% +Cobalt waxin is by definition not dilute + + + align:start position:0% +Cobalt waxin is by definition not dilute +you essentially can go all the way from + + align:start position:0% +you essentially can go all the way from + + + align:start position:0% +you essentially can go all the way from +all lithium on the SES to all vacancies + + align:start position:0% +all lithium on the SES to all vacancies + + + align:start position:0% +all lithium on the SES to all vacancies +on the SES okay so you go to very non- + + align:start position:0% +on the SES okay so you go to very non- + + + align:start position:0% +on the SES okay so you go to very non- +dilute regimes um if you want to do that + + align:start position:0% +dilute regimes um if you want to do that + + + align:start position:0% +dilute regimes um if you want to do that +you need to actually simulate the + + align:start position:0% +you need to actually simulate the + + + align:start position:0% +you need to actually simulate the +diffusion and and you may have even done + + align:start position:0% +diffusion and and you may have even done + + + align:start position:0% +diffusion and and you may have even done +that in the MD homework um by doing some + + align:start position:0% +that in the MD homework um by doing some + + + align:start position:0% +that in the MD homework um by doing some +kinetic model and then tracking the root + + align:start position:0% +kinetic model and then tracking the root + + + align:start position:0% +kinetic model and then tracking the root +mean Square displacement um this is sort + + align:start position:0% +mean Square displacement um this is sort + + + align:start position:0% +mean Square displacement um this is sort +of a simple form for the self diffusion + + align:start position:0% +of a simple form for the self diffusion + + + align:start position:0% +of a simple form for the self diffusion +um the chemical diffusion constant which + + align:start position:0% +um the chemical diffusion constant which + + + align:start position:0% +um the chemical diffusion constant which +is the one you would use in macroscopic + + align:start position:0% +is the one you would use in macroscopic + + + align:start position:0% +is the one you would use in macroscopic +theories is the self diffusion times the + + align:start position:0% +theories is the self diffusion times the + + + align:start position:0% +theories is the self diffusion times the +ther thermodynamic Factor but the + + align:start position:0% +ther thermodynamic Factor but the + + + align:start position:0% +ther thermodynamic Factor but the +thermodynamic factor is essentially the + + align:start position:0% +thermodynamic factor is essentially the + + + align:start position:0% +thermodynamic factor is essentially the +derivative of the chemical potential + + align:start position:0% +derivative of the chemical potential + + + align:start position:0% +derivative of the chemical potential +with composition so that you already + + align:start position:0% +with composition so that you already + + + align:start position:0% +with composition so that you already +have from the thermodynamic + + align:start position:0% + + + + align:start position:0% + +calculation okay + + align:start position:0% +calculation okay + + + align:start position:0% +calculation okay +um so I have a few more slides here that + + align:start position:0% +um so I have a few more slides here that + + + align:start position:0% +um so I have a few more slides here that +I already Ed so I'm going to create to + + align:start position:0% +I already Ed so I'm going to create to + + + align:start position:0% +I already Ed so I'm going to create to +them uh you remember how we did the + + align:start position:0% +them uh you remember how we did the + + + align:start position:0% +them uh you remember how we did the +thermodynamics so we build a latus model + + align:start position:0% +thermodynamics so we build a latus model + + + align:start position:0% +thermodynamics so we build a latus model +uh we calculate a lot of lithium vacancy + + align:start position:0% +uh we calculate a lot of lithium vacancy + + + align:start position:0% +uh we calculate a lot of lithium vacancy +Arrangement build a cluster expansion + + align:start position:0% +Arrangement build a cluster expansion + + + align:start position:0% +Arrangement build a cluster expansion +and do Monte Carlo on that and that + + align:start position:0% +and do Monte Carlo on that and that + + + align:start position:0% +and do Monte Carlo on that and that +gives you the phase + + align:start position:0% +gives you the phase + + + align:start position:0% +gives you the phase +diagram um me skip that since we did + + align:start position:0% +diagram um me skip that since we did + + + align:start position:0% +diagram um me skip that since we did +that already those are the interactions + + align:start position:0% +that already those are the interactions + + + align:start position:0% +that already those are the interactions +okay + + align:start position:0% +okay + + + align:start position:0% +okay +um how would you do kinetic Monte Carlo + + align:start position:0% +um how would you do kinetic Monte Carlo + + + align:start position:0% +um how would you do kinetic Monte Carlo +I sort of also mentioned that you would + + align:start position:0% +I sort of also mentioned that you would + + + align:start position:0% +I sort of also mentioned that you would +now execute only exchanges in the Monte + + align:start position:0% +now execute only exchanges in the Monte + + + align:start position:0% +now execute only exchanges in the Monte +Carlo that look like diffusive processes + + align:start position:0% +Carlo that look like diffusive processes + + + align:start position:0% +Carlo that look like diffusive processes +and you would execute them with the + + align:start position:0% +and you would execute them with the + + + align:start position:0% +and you would execute them with the +proper rate um so you would have an + + align:start position:0% +proper rate um so you would have an + + + align:start position:0% +proper rate um so you would have an +activation barrier in + + align:start position:0% + + + + align:start position:0% + +there okay I think I said all this + + align:start position:0% +there okay I think I said all this + + + align:start position:0% +there okay I think I said all this +okay so here's an example of how that + + align:start position:0% +okay so here's an example of how that + + + align:start position:0% +okay so here's an example of how that +works + + align:start position:0% +works + + + align:start position:0% +works +out uh if you calculate barriers in + + align:start position:0% +out uh if you calculate barriers in + + + align:start position:0% +out uh if you calculate barriers in +lithium Coral oxide and you then do a + + align:start position:0% +lithium Coral oxide and you then do a + + + align:start position:0% +lithium Coral oxide and you then do a +kinetic mon caral simulation you keep + + align:start position:0% +kinetic mon caral simulation you keep + + + align:start position:0% +kinetic mon caral simulation you keep +track of the root mean Square + + align:start position:0% +track of the root mean Square + + + align:start position:0% +track of the root mean Square +displacement uh you get the macroscopic + + align:start position:0% +displacement uh you get the macroscopic + + + align:start position:0% +displacement uh you get the macroscopic +diffusivity uh and as you see um it + + align:start position:0% +diffusivity uh and as you see um it + + + align:start position:0% +diffusivity uh and as you see um it +varies by orders of magnitude it's 10- 7 + + align:start position:0% +varies by orders of magnitude it's 10- 7 + + + align:start position:0% +varies by orders of magnitude it's 10- 7 +here C uh cenim s/ Second and it's 10-3 + + align:start position:0% +here C uh cenim s/ Second and it's 10-3 + + + align:start position:0% +here C uh cenim s/ Second and it's 10-3 +here you can already see that you would + + align:start position:0% +here you can already see that you would + + + align:start position:0% +here you can already see that you would +never get to all these time scales uh + + align:start position:0% +never get to all these time scales uh + + + align:start position:0% +never get to all these time scales uh +with a simple Dynamics uh + + align:start position:0% + + + + align:start position:0% + +model okay um how you get uh activation + + align:start position:0% +model okay um how you get uh activation + + + align:start position:0% +model okay um how you get uh activation +barriers uh typically we get this with + + align:start position:0% +barriers uh typically we get this with + + + align:start position:0% +barriers uh typically we get this with +what's called a nud nudged elastic band + + align:start position:0% +what's called a nud nudged elastic band + + + align:start position:0% +what's called a nud nudged elastic band +model um you + + align:start position:0% +model um you + + + align:start position:0% +model um you +know what's the issue in finding + + align:start position:0% +know what's the issue in finding + + + align:start position:0% +know what's the issue in finding +activation barriers well you know the + + align:start position:0% +activation barriers well you know the + + + align:start position:0% +activation barriers well you know the +initial State and you know the final + + align:start position:0% +initial State and you know the final + + + align:start position:0% +initial State and you know the final +State this is not necessarily the state + + align:start position:0% +State this is not necessarily the state + + + align:start position:0% +State this is not necessarily the state +of an atom you really should think of + + align:start position:0% +of an atom you really should think of + + + align:start position:0% +of an atom you really should think of +these as two states in face space now if + + align:start position:0% +these as two states in face space now if + + + align:start position:0% +these as two states in face space now if +for Simplicity you can think well only + + align:start position:0% +for Simplicity you can think well only + + + align:start position:0% +for Simplicity you can think well only +one atom moves is different between the + + align:start position:0% +one atom moves is different between the + + + align:start position:0% +one atom moves is different between the +those two states but in reality more + + align:start position:0% +those two states but in reality more + + + align:start position:0% +those two states but in reality more +stuff is different because if the atom + + align:start position:0% +stuff is different because if the atom + + + align:start position:0% +stuff is different because if the atom +has moved the other atoms may have + + align:start position:0% +has moved the other atoms may have + + + align:start position:0% +has moved the other atoms may have +relaxed around it so these are really + + align:start position:0% +relaxed around it so these are really + + + align:start position:0% +relaxed around it so these are really +States in face space um so what you have + + align:start position:0% +States in face space um so what you have + + + align:start position:0% +States in face space um so what you have +to find is the path between the + + align:start position:0% +to find is the path between the + + + align:start position:0% +to find is the path between the +two with the lowest Max Energy maximum + + align:start position:0% +two with the lowest Max Energy maximum + + + align:start position:0% +two with the lowest Max Energy maximum +along that path that's essentially the + + align:start position:0% +along that path that's essentially the + + + align:start position:0% +along that path that's essentially the +activated State um and a very practical + + align:start position:0% +activated State um and a very practical + + + align:start position:0% +activated State um and a very practical +way to find is What's called the nudge + + align:start position:0% +way to find is What's called the nudge + + + align:start position:0% +way to find is What's called the nudge +elastic band model which is essentially + + align:start position:0% +elastic band model which is essentially + + + align:start position:0% +elastic band model which is essentially +that you do a + + align:start position:0% +that you do a + + + align:start position:0% +that you do a +simulation uh on many systems at a time + + align:start position:0% +simulation uh on many systems at a time + + + align:start position:0% +simulation uh on many systems at a time +and all the systems live at intermediate + + align:start position:0% +and all the systems live at intermediate + + + align:start position:0% +and all the systems live at intermediate +States between the inti the final State + + align:start position:0% +States between the inti the final State + + + align:start position:0% +States between the inti the final State +and the initial State and the way you + + align:start position:0% +and the initial State and the way you + + + align:start position:0% +and the initial State and the way you +keep them there is interesting um rather + + align:start position:0% +keep them there is interesting um rather + + + align:start position:0% +keep them there is interesting um rather +than optimizing the energy of each + + align:start position:0% +than optimizing the energy of each + + + align:start position:0% +than optimizing the energy of each +system what you optimize is the sum of + + align:start position:0% +system what you optimize is the sum of + + + align:start position:0% +system what you optimize is the sum of +their energies okay the sum of their + + align:start position:0% +their energies okay the sum of their + + + align:start position:0% +their energies okay the sum of their +hamiltonian values okay plus some spring + + align:start position:0% +hamiltonian values okay plus some spring + + + align:start position:0% +hamiltonian values okay plus some spring +constant okay basically plus some energy + + align:start position:0% +constant okay basically plus some energy + + + align:start position:0% +constant okay basically plus some energy +penalty which is associated with the + + align:start position:0% +penalty which is associated with the + + + align:start position:0% +penalty which is associated with the +difference in coordinate between the two + + align:start position:0% +difference in coordinate between the two + + + align:start position:0% +difference in coordinate between the two +systems and what that tends to do is + + align:start position:0% +systems and what that tends to do is + + + align:start position:0% +systems and what that tends to do is +actually since this is a quadratic in + + align:start position:0% +actually since this is a quadratic in + + + align:start position:0% +actually since this is a quadratic in +the difference in coordinates it tends + + align:start position:0% +the difference in coordinates it tends + + + align:start position:0% +the difference in coordinates it tends +to spread + + align:start position:0% +to spread + + + align:start position:0% +to spread +out the systems along the path between + + align:start position:0% +out the systems along the path between + + + align:start position:0% +out the systems along the path between +the two states I mean think of it if I + + align:start position:0% +the two states I mean think of it if I + + + align:start position:0% +the two states I mean think of it if I +got rid of this so if I set K to zero + + align:start position:0% +got rid of this so if I set K to zero + + + align:start position:0% +got rid of this so if I set K to zero +then you know I'm going to minimize this + + align:start position:0% +then you know I'm going to minimize this + + + align:start position:0% +then you know I'm going to minimize this +so they're all going to go down here but + + align:start position:0% +so they're all going to go down here but + + + align:start position:0% +so they're all going to go down here but +what you actually do is you hold one + + align:start position:0% +what you actually do is you hold one + + + align:start position:0% +what you actually do is you hold one +here you hold one there um and then + + align:start position:0% +here you hold one there um and then + + + align:start position:0% +here you hold one there um and then +because of the harmonic potential + + align:start position:0% +because of the harmonic potential + + + align:start position:0% +because of the harmonic potential +between them you tend to end up with + + align:start position:0% +between them you tend to end up with + + + align:start position:0% +between them you tend to end up with +systems that live in between so it's a + + align:start position:0% +systems that live in between so it's a + + + align:start position:0% +systems that live in between so it's a +very elegant way of finding um minimum + + align:start position:0% +very elegant way of finding um minimum + + + align:start position:0% +very elegant way of finding um minimum +energy paths between states um it's + + align:start position:0% +energy paths between states um it's + + + align:start position:0% +energy paths between states um it's +called the elastic band method or the + + align:start position:0% +called the elastic band method or the + + + align:start position:0% +called the elastic band method or the +nudg elastic band method and there's a + + align:start position:0% +nudg elastic band method and there's a + + + align:start position:0% +nudg elastic band method and there's a +whole bunch of variants of it um as well + + align:start position:0% +whole bunch of variants of it um as well + + + align:start position:0% +whole bunch of variants of it um as well +um it's the perfect parallelization may + + align:start position:0% +um it's the perfect parallelization may + + + align:start position:0% +um it's the perfect parallelization may +have noticed you you can run if you want + + align:start position:0% +have noticed you you can run if you want + + + align:start position:0% +have noticed you you can run if you want +to do say 10 r replicas so you want to + + align:start position:0% +to do say 10 r replicas so you want to + + + align:start position:0% +to do say 10 r replicas so you want to +do 10 points along the path you run on + + align:start position:0% +do 10 points along the path you run on + + + align:start position:0% +do 10 points along the path you run on +10 processors because it's the same + + align:start position:0% +10 processors because it's the same + + + align:start position:0% +10 processors because it's the same +system they pretty much run about the + + align:start position:0% +system they pretty much run about the + + + align:start position:0% +system they pretty much run about the +same amount of time they never have to + + align:start position:0% +same amount of time they never have to + + + align:start position:0% +same amount of time they never have to +talk to each other they have to talk to + + align:start position:0% +talk to each other they have to talk to + + + align:start position:0% +talk to each other they have to talk to +each other on extremely rare occasion + + align:start position:0% +each other on extremely rare occasion + + + align:start position:0% +each other on extremely rare occasion +when they exchange coordinat that's it + + align:start position:0% +when they exchange coordinat that's it + + + align:start position:0% +when they exchange coordinat that's it +so it's perfect paralyzation + + align:start position:0% + + + + align:start position:0% + +Tool uh if you do that in lithium cobal + + align:start position:0% +Tool uh if you do that in lithium cobal + + + align:start position:0% +Tool uh if you do that in lithium cobal +oxide you have a + + align:start position:0% +oxide you have a + + + align:start position:0% +oxide you have a +complication um just to show you how the + + align:start position:0% +complication um just to show you how the + + + align:start position:0% +complication um just to show you how the +data for kinetic mon Carlo simulation + + align:start position:0% +data for kinetic mon Carlo simulation + + + align:start position:0% +data for kinetic mon Carlo simulation +was derived um the yellow is the lithium + + align:start position:0% +was derived um the yellow is the lithium + + + align:start position:0% +was derived um the yellow is the lithium +here uh these are oxygens the the big + + align:start position:0% +here uh these are oxygens the the big + + + align:start position:0% +here uh these are oxygens the the big +red balls uh the way you can diffuse + + align:start position:0% +red balls uh the way you can diffuse + + + align:start position:0% +red balls uh the way you can diffuse +from this side to that side is straight + + align:start position:0% +from this side to that side is straight + + + align:start position:0% +from this side to that side is straight +through the oxygen Bond and if you do + + align:start position:0% +through the oxygen Bond and if you do + + + align:start position:0% +through the oxygen Bond and if you do +that this is this is obtained by elastic + + align:start position:0% +that this is this is obtained by elastic + + + align:start position:0% +that this is this is obtained by elastic +band method so these are the replicas so + + align:start position:0% +band method so these are the replicas so + + + align:start position:0% +band method so these are the replicas so +this is initial State this is the final + + align:start position:0% +this is initial State this is the final + + + align:start position:0% +this is initial State this is the final +State and so you get an activation bear + + align:start position:0% +State and so you get an activation bear + + + align:start position:0% +State and so you get an activation bear +of about 085 + + align:start position:0% + + + + align:start position:0% + +um so you it's very nice how you get + + align:start position:0% +um so you it's very nice how you get + + + align:start position:0% +um so you it's very nice how you get +these activation curves um but the + + align:start position:0% +these activation curves um but the + + + align:start position:0% +these activation curves um but the +problem is that there's two paths in + + align:start position:0% +problem is that there's two paths in + + + align:start position:0% +problem is that there's two paths in +this material so already you're starting + + align:start position:0% +this material so already you're starting + + + align:start position:0% +this material so already you're starting +to run into a particular problem of + + align:start position:0% +to run into a particular problem of + + + align:start position:0% +to run into a particular problem of +kinetic Monte Carlo that let's say you + + align:start position:0% +kinetic Monte Carlo that let's say you + + + align:start position:0% +kinetic Monte Carlo that let's say you +thought that was the path well you'd be + + align:start position:0% +thought that was the path well you'd be + + + align:start position:0% +thought that was the path well you'd be +very wrong because there's another path + + align:start position:0% +very wrong because there's another path + + + align:start position:0% +very wrong because there's another path +um and that's one when the atom actually + + align:start position:0% +um and that's one when the atom actually + + + align:start position:0% +um and that's one when the atom actually +rather than going straight through this + + align:start position:0% +rather than going straight through this + + + align:start position:0% +rather than going straight through this +Bond it takes a curve into this + + align:start position:0% +Bond it takes a curve into this + + + align:start position:0% +Bond it takes a curve into this +tetrahedron + + align:start position:0% +tetrahedron + + + align:start position:0% +tetrahedron +and comes back out and that's actually a + + align:start position:0% +and comes back out and that's actually a + + + align:start position:0% +and comes back out and that's actually a +pad if you do elastic band that is so + + align:start position:0% +pad if you do elastic band that is so + + + align:start position:0% +pad if you do elastic band that is so +much lower it's only about 200 M + + align:start position:0% +much lower it's only about 200 M + + + align:start position:0% +much lower it's only about 200 M +electron volts and it sort of shows the + + align:start position:0% +electron volts and it sort of shows the + + + align:start position:0% +electron volts and it sort of shows the +real problem you can run into that when + + align:start position:0% +real problem you can run into that when + + + align:start position:0% +real problem you can run into that when +you do kinetic mon Carlo you have to + + align:start position:0% +you do kinetic mon Carlo you have to + + + align:start position:0% +you do kinetic mon Carlo you have to +assume what your paths are for + + align:start position:0% +assume what your paths are for + + + align:start position:0% +assume what your paths are for +Transitions and if you don't get them + + align:start position:0% +Transitions and if you don't get them + + + align:start position:0% +Transitions and if you don't get them +right you can be seriously wrong and + + align:start position:0% +right you can be seriously wrong and + + + align:start position:0% +right you can be seriously wrong and +that's one of the nice things of MD that + + align:start position:0% +that's one of the nice things of MD that + + + align:start position:0% +that's one of the nice things of MD that +it's unbiased so it would find these + + align:start position:0% +it's unbiased so it would find these + + + align:start position:0% +it's unbiased so it would find these +things um for you but these are actually + + align:start position:0% +things um for you but these are actually + + + align:start position:0% +things um for you but these are actually +the only two paths and of course because + + align:start position:0% +the only two paths and of course because + + + align:start position:0% +the only two paths and of course because +the activation barrier of this is so + + align:start position:0% +the activation barrier of this is so + + + align:start position:0% +the activation barrier of this is so +much lower this is pretty much the one + + align:start position:0% +much lower this is pretty much the one + + + align:start position:0% +much lower this is pretty much the one +that gets executed almost all the time + + align:start position:0% +that gets executed almost all the time + + + align:start position:0% +that gets executed almost all the time +you know the difference between 0 2 EV + + align:start position:0% +you know the difference between 0 2 EV + + + align:start position:0% +you know the difference between 0 2 EV +and 08 EV at room temperature is amazing + + align:start position:0% +and 08 EV at room temperature is amazing + + + align:start position:0% +and 08 EV at room temperature is amazing +it's uh you know I think five six orders + + align:start position:0% +it's uh you know I think five six orders + + + align:start position:0% +it's uh you know I think five six orders +of magnitude in in in rate constant you + + align:start position:0% +of magnitude in in in rate constant you + + + align:start position:0% +of magnitude in in in rate constant you +just have to calculate the exponential + + align:start position:0% +just have to calculate the exponential + + + align:start position:0% +just have to calculate the exponential +of each of + + align:start position:0% +of each of + + + align:start position:0% +of each of +these + + align:start position:0% +these + + + align:start position:0% +these +um one of the problems you have whenever + + align:start position:0% +um one of the problems you have whenever + + + align:start position:0% +um one of the problems you have whenever +you have two rate constants uh um is + + align:start position:0% +you have two rate constants uh um is + + + align:start position:0% +you have two rate constants uh um is +that when you do your mon Carlo you can + + align:start position:0% +that when you do your mon Carlo you can + + + align:start position:0% +that when you do your mon Carlo you can +only scale the fastest one + + align:start position:0% +only scale the fastest one + + + align:start position:0% +only scale the fastest one +away so you have essentially one scale + + align:start position:0% +away so you have essentially one scale + + + align:start position:0% +away so you have essentially one scale +factor in the time of your mon Carlo + + align:start position:0% +factor in the time of your mon Carlo + + + align:start position:0% +factor in the time of your mon Carlo +simulation so when you do multiple time + + align:start position:0% +simulation so when you do multiple time + + + align:start position:0% +simulation so when you do multiple time +scales uh when you have multiple time + + align:start position:0% +scales uh when you have multiple time + + + align:start position:0% +scales uh when you have multiple time +scales it gets very inefficient to do + + align:start position:0% +scales it gets very inefficient to do + + + align:start position:0% +scales it gets very inefficient to do +kinetic mon + + align:start position:0% +kinetic mon + + + align:start position:0% +kinetic mon +Cara but this works you can get + + align:start position:0% +Cara but this works you can get + + + align:start position:0% +Cara but this works you can get +diffusion constants um this is + + align:start position:0% +diffusion constants um this is + + + align:start position:0% +diffusion constants um this is +with uh elastic band method this is the + + align:start position:0% +with uh elastic band method this is the + + + align:start position:0% +with uh elastic band method this is the +activation for that low energy mechanism + + align:start position:0% +activation for that low energy mechanism + + + align:start position:0% +activation for that low energy mechanism +as a function of lithium concentration + + align:start position:0% +as a function of lithium concentration + + + align:start position:0% +as a function of lithium concentration +so very dependent on concentration so + + align:start position:0% +so very dependent on concentration so + + + align:start position:0% +so very dependent on concentration so +you can do your kinetic Monte Carlo and + + align:start position:0% +you can do your kinetic Monte Carlo and + + + align:start position:0% +you can do your kinetic Monte Carlo and +then you know you have these and you can + + align:start position:0% +then you know you have these and you can + + + align:start position:0% +then you know you have these and you can +go all the way to macroscopic simulation + + align:start position:0% +go all the way to macroscopic simulation + + + align:start position:0% +go all the way to macroscopic simulation +then you can solve fix equation and + + align:start position:0% +then you can solve fix equation and + + + align:start position:0% +then you can solve fix equation and +actually look at you know diffusion on + + align:start position:0% +actually look at you know diffusion on + + + align:start position:0% +actually look at you know diffusion on +the scale of microns so it's a sort of + + align:start position:0% +the scale of microns so it's a sort of + + + align:start position:0% +the scale of microns so it's a sort of +Fairly simplistic way of cor + + align:start position:0% +Fairly simplistic way of cor + + + align:start position:0% +Fairly simplistic way of cor +graining + + align:start position:0% +graining + + + align:start position:0% +graining +um okay so I'm going to end just uh + + align:start position:0% +um okay so I'm going to end just uh + + + align:start position:0% +um okay so I'm going to end just uh +giving you some reference if you want to + + align:start position:0% +giving you some reference if you want to + + + align:start position:0% +giving you some reference if you want to +read more about the Quasi continu method + + align:start position:0% +read more about the Quasi continu method + + + align:start position:0% +read more about the Quasi continu method +uh there's these great papers by Miller + + align:start position:0% +uh there's these great papers by Miller + + + align:start position:0% +uh there's these great papers by Miller +and tadmore these are actually somewhat + + align:start position:0% +and tadmore these are actually somewhat + + + align:start position:0% +and tadmore these are actually somewhat +similar but the 202 version is an update + + align:start position:0% +similar but the 202 version is an update + + + align:start position:0% +similar but the 202 version is an update +uh these are not the original papers but + + align:start position:0% +uh these are not the original papers but + + + align:start position:0% +uh these are not the original papers but +uh they're actually some more + + align:start position:0% +uh they're actually some more + + + align:start position:0% +uh they're actually some more +pedagogical than the original papers you + + align:start position:0% +pedagogical than the original papers you + + + align:start position:0% +pedagogical than the original papers you +but you'll find the references in there + + align:start position:0% +but you'll find the references in there + + + align:start position:0% +but you'll find the references in there +to the original papers um the problem of + + align:start position:0% +to the original papers um the problem of + + + align:start position:0% +to the original papers um the problem of +sort of + + align:start position:0% +sort of + + + align:start position:0% +sort of +Dynamics uh at that scale is my own work + + align:start position:0% +Dynamics uh at that scale is my own work + + + align:start position:0% +Dynamics uh at that scale is my own work +um The Accelerated MD uh there's a + + align:start position:0% +um The Accelerated MD uh there's a + + + align:start position:0% +um The Accelerated MD uh there's a +series of papers by Art voter but uh + + align:start position:0% +series of papers by Art voter but uh + + + align:start position:0% +series of papers by Art voter but uh +this annual review of materials research + + align:start position:0% +this annual review of materials research + + + align:start position:0% +this annual review of materials research +is a I think a great review uh if you + + align:start position:0% +is a I think a great review uh if you + + + align:start position:0% +is a I think a great review uh if you +want to read about it and the lithium + + align:start position:0% +want to read about it and the lithium + + + align:start position:0% +want to read about it and the lithium +Cobalt application um is is in a few + + align:start position:0% +Cobalt application um is is in a few + + + align:start position:0% +Cobalt application um is is in a few +papers but it's quite elaborate the + + align:start position:0% +papers but it's quite elaborate the + + + align:start position:0% +papers but it's quite elaborate the +whole idea of kinetic Monte Carlo and + + align:start position:0% +whole idea of kinetic Monte Carlo and + + + align:start position:0% +whole idea of kinetic Monte Carlo and +parameterizing activation bearers is + + align:start position:0% +parameterizing activation bearers is + + + align:start position:0% +parameterizing activation bearers is +quite elaborately um discussed in this + + align:start position:0% +quite elaborately um discussed in this + + + align:start position:0% +quite elaborately um discussed in this +paper so I think we're done a little + + align:start position:0% +paper so I think we're done a little + + + align:start position:0% +paper so I think we're done a little +early but that's fine so I'm going to + + align:start position:0% +early but that's fine so I'm going to + + + align:start position:0% +early but that's fine so I'm going to +end here and uh I'll see you on Thursday + + align:start position:0% +end here and uh I'll see you on Thursday + + + align:start position:0% +end here and uh I'll see you on Thursday +for uh the lecture from Fort \ No newline at end of file diff --git a/SgJo7_4mp6w.txt b/SgJo7_4mp6w.txt new file mode 100644 index 0000000000000000000000000000000000000000..e8930564346f2b1ac793e905f5acd24d6e3ee40b --- /dev/null +++ b/SgJo7_4mp6w.txt @@ -0,0 +1,1376 @@ +align:start position:0% + +hi welcome back to recitation in lecture + + align:start position:0% +hi welcome back to recitation in lecture + + + align:start position:0% +hi welcome back to recitation in lecture +you've been learning about planes and + + align:start position:0% +you've been learning about planes and + + + align:start position:0% +you've been learning about planes and +their equations and various different + + align:start position:0% +their equations and various different + + + align:start position:0% +their equations and various different +geometric problems relating to them so I + + align:start position:0% +geometric problems relating to them so I + + + align:start position:0% +geometric problems relating to them so I +have an example of such a problem here + + align:start position:0% +have an example of such a problem here + + + align:start position:0% +have an example of such a problem here +so I've got a point which happens to be + + align:start position:0% +so I've got a point which happens to be + + + align:start position:0% +so I've got a point which happens to be +the origin which I'm going to call P + + align:start position:0% +the origin which I'm going to call P + + + align:start position:0% +the origin which I'm going to call P +0000 0 and I've got a plane which has + + align:start position:0% +0000 0 and I've got a plane which has + + + align:start position:0% +0000 0 and I've got a plane which has +the equation 2x + y - 2 Z is Al to four + + align:start position:0% +the equation 2x + y - 2 Z is Al to four + + + align:start position:0% +the equation 2x + y - 2 Z is Al to four +and what I'd like you to do is compute + + align:start position:0% +and what I'd like you to do is compute + + + align:start position:0% +and what I'd like you to do is compute +the distance from that point to that + + align:start position:0% +the distance from that point to that + + + align:start position:0% +the distance from that point to that +plane so um just to to to remind you the + + align:start position:0% +plane so um just to to to remind you the + + + align:start position:0% +plane so um just to to to remind you the +distance so there are lots of points on + + align:start position:0% +distance so there are lots of points on + + + align:start position:0% +distance so there are lots of points on +a plane of course and and our point in + + align:start position:0% +a plane of course and and our point in + + + align:start position:0% +a plane of course and and our point in +question has a distance to each of them + + align:start position:0% +question has a distance to each of them + + + align:start position:0% +question has a distance to each of them +when we talk about the distance between + + align:start position:0% +when we talk about the distance between + + + align:start position:0% +when we talk about the distance between +a point and a plane what we mean is the + + align:start position:0% +a point and a plane what we mean is the + + + align:start position:0% +a point and a plane what we mean is the +shortest distance so the the the + + align:start position:0% +shortest distance so the the the + + + align:start position:0% +shortest distance so the the the +perpendicular distance so if we have if + + align:start position:0% +perpendicular distance so if we have if + + + align:start position:0% +perpendicular distance so if we have if +we have the plane and we have the point + + align:start position:0% +we have the plane and we have the point + + + align:start position:0% +we have the plane and we have the point +so we we want to drop a perpendicular + + align:start position:0% +so we we want to drop a perpendicular + + + align:start position:0% +so we we want to drop a perpendicular +from from the point to the plane and + + align:start position:0% +from from the point to the plane and + + + align:start position:0% +from from the point to the plane and +then we're asking for for for that + + align:start position:0% +then we're asking for for for that + + + align:start position:0% +then we're asking for for for that +length of that segment um so that's + + align:start position:0% +length of that segment um so that's + + + align:start position:0% +length of that segment um so that's +that's the distance between the point + + align:start position:0% +that's the distance between the point + + + align:start position:0% +that's the distance between the point +and the plane so why don't you pause the + + align:start position:0% +and the plane so why don't you pause the + + + align:start position:0% +and the plane so why don't you pause the +video take a little while to uh to + + align:start position:0% +video take a little while to uh to + + + align:start position:0% +video take a little while to uh to +figure this out come back and we can + + align:start position:0% +figure this out come back and we can + + + align:start position:0% +figure this out come back and we can +figure it out + + align:start position:0% + + + + align:start position:0% + +together so hopefully you had some luck + + align:start position:0% +together so hopefully you had some luck + + + align:start position:0% +together so hopefully you had some luck +working out this problem let's uh let's + + align:start position:0% +working out this problem let's uh let's + + + align:start position:0% +working out this problem let's uh let's +let's think about it a little bit we + + align:start position:0% +let's think about it a little bit we + + + align:start position:0% +let's think about it a little bit we +have we have a point and we have a plane + + align:start position:0% +have we have a point and we have a plane + + + align:start position:0% +have we have a point and we have a plane +and we want to figure out what the what + + align:start position:0% +and we want to figure out what the what + + + align:start position:0% +and we want to figure out what the what +the perpendicular distance from from the + + align:start position:0% +the perpendicular distance from from the + + + align:start position:0% +the perpendicular distance from from the +point to the plane is um so one thing + + align:start position:0% +point to the plane is um so one thing + + + align:start position:0% +point to the plane is um so one thing +that's going to be important then is + + align:start position:0% +that's going to be important then is + + + align:start position:0% +that's going to be important then is +definitely knowing what what direction + + align:start position:0% +definitely knowing what what direction + + + align:start position:0% +definitely knowing what what direction +that that Vector is right we have the + + align:start position:0% +that that Vector is right we have the + + + align:start position:0% +that that Vector is right we have the +plane and and we and we want to find the + + align:start position:0% +plane and and we and we want to find the + + + align:start position:0% +plane and and we and we want to find the +a perpendicular segment to it um and so + + align:start position:0% +a perpendicular segment to it um and so + + + align:start position:0% +a perpendicular segment to it um and so +in order to do that it's it's useful to + + align:start position:0% +in order to do that it's it's useful to + + + align:start position:0% +in order to do that it's it's useful to +know which what direction is that + + align:start position:0% +know which what direction is that + + + align:start position:0% +know which what direction is that +segment pointing in so luckily we're + + align:start position:0% +segment pointing in so luckily we're + + + align:start position:0% +segment pointing in so luckily we're +given the plane in this in this simple + + align:start position:0% +given the plane in this in this simple + + + align:start position:0% +given the plane in this in this simple +equation form so the normal to the plane + + align:start position:0% + + + + align:start position:0% + +and when you're given an equation of a + + align:start position:0% +and when you're given an equation of a + + + align:start position:0% +and when you're given an equation of a +plane in this form the the normal + + align:start position:0% + + + + align:start position:0% + +Vector is just given by the the + + align:start position:0% +Vector is just given by the the + + + align:start position:0% +Vector is just given by the the +coefficients + + align:start position:0% + + + + align:start position:0% + +of X Y and Z so in our case the plane is + + align:start position:0% +of X Y and Z so in our case the plane is + + + align:start position:0% +of X Y and Z so in our case the plane is +2x + y - 2 Z = 4 so the normal Vector to + + align:start position:0% +2x + y - 2 Z = 4 so the normal Vector to + + + align:start position:0% +2x + y - 2 Z = 4 so the normal Vector to +this plane is the vector 2 1us 2 so this + + align:start position:0% +this plane is the vector 2 1us 2 so this + + + align:start position:0% +this plane is the vector 2 1us 2 so this +is the + + align:start position:0% +is the + + + align:start position:0% +is the +direction um in in which we need to go + + align:start position:0% +direction um in in which we need to go + + + align:start position:0% +direction um in in which we need to go +from our Point p in order to get to the + + align:start position:0% +from our Point p in order to get to the + + + align:start position:0% +from our Point p in order to get to the +plane by the by the shortest distance so + + align:start position:0% +plane by the by the shortest distance so + + + align:start position:0% +plane by the by the shortest distance so +now what we need is we need to know the + + align:start position:0% +now what we need is we need to know the + + + align:start position:0% +now what we need is we need to know the +component of oh sorry rather we need to + + align:start position:0% +component of oh sorry rather we need to + + + align:start position:0% +component of oh sorry rather we need to +know the the distance the the actual + + align:start position:0% +know the the distance the the actual + + + align:start position:0% +know the the distance the the actual +distance we have to travel in that + + align:start position:0% +distance we have to travel in that + + + align:start position:0% +distance we have to travel in that +direction um so one way to do this is if + + align:start position:0% +direction um so one way to do this is if + + + align:start position:0% +direction um so one way to do this is if +we go back to our little picture here + + align:start position:0% +we go back to our little picture here + + + align:start position:0% +we go back to our little picture here +if we choose we we don't know what this + + align:start position:0% +if we choose we we don't know what this + + + align:start position:0% +if we choose we we don't know what this +point is we don't know when we start + + align:start position:0% +point is we don't know when we start + + + align:start position:0% +point is we don't know when we start +from p and head in a direction + + align:start position:0% +from p and head in a direction + + + align:start position:0% +from p and head in a direction +perpendicular to the plane we don't know + + align:start position:0% +perpendicular to the plane we don't know + + + align:start position:0% +perpendicular to the plane we don't know +what point we're going to land on the + + align:start position:0% +what point we're going to land on the + + + align:start position:0% +what point we're going to land on the +plane at um but what we could do is if + + align:start position:0% +plane at um but what we could do is if + + + align:start position:0% +plane at um but what we could do is if +we knew some other point on the + + align:start position:0% +we knew some other point on the + + + align:start position:0% +we knew some other point on the +plane somewhere we could look at the + + align:start position:0% +plane somewhere we could look at the + + + align:start position:0% +plane somewhere we could look at the +vector connecting P to that other point + + align:start position:0% +vector connecting P to that other point + + + align:start position:0% +vector connecting P to that other point +and then we could project it onto the + + align:start position:0% +and then we could project it onto the + + + align:start position:0% +and then we could project it onto the +normal Direction so we could can take + + align:start position:0% +normal Direction so we could can take + + + align:start position:0% +normal Direction so we could can take +the components let's call this other + + align:start position:0% +the components let's call this other + + + align:start position:0% +the components let's call this other +point Q so if we choose any point Q in + + align:start position:0% +point Q so if we choose any point Q in + + + align:start position:0% +point Q so if we choose any point Q in +the plane that we're looking at we can + + align:start position:0% +the plane that we're looking at we can + + + align:start position:0% +the plane that we're looking at we can +take the vector PQ and we can project it + + align:start position:0% +take the vector PQ and we can project it + + + align:start position:0% +take the vector PQ and we can project it +onto this normal vector and if we take + + align:start position:0% +onto this normal vector and if we take + + + align:start position:0% +onto this normal vector and if we take +the component of of this Vector + + align:start position:0% +the component of of this Vector + + + align:start position:0% +the component of of this Vector +projected onto that normal Vector if we + + align:start position:0% +projected onto that normal Vector if we + + + align:start position:0% +projected onto that normal Vector if we +if we take the component of this Vector + + align:start position:0% +if we take the component of this Vector + + + align:start position:0% +if we take the component of this Vector +in the direction of the normal Vector + + align:start position:0% +in the direction of the normal Vector + + + align:start position:0% +in the direction of the normal Vector +what that'll give us is exactly the the + + align:start position:0% +what that'll give us is exactly the the + + + align:start position:0% +what that'll give us is exactly the the +length of this segment yeah that + + align:start position:0% +length of this segment yeah that + + + align:start position:0% +length of this segment yeah that +projection will be exactly the the + + align:start position:0% +projection will be exactly the the + + + align:start position:0% +projection will be exactly the the +perpendicular ular segment we're looking + + align:start position:0% +perpendicular ular segment we're looking + + + align:start position:0% +perpendicular ular segment we're looking +for and its length the component or the + + align:start position:0% +for and its length the component or the + + + align:start position:0% +for and its length the component or the +absolute value of the component perhaps + + align:start position:0% +absolute value of the component perhaps + + + align:start position:0% +absolute value of the component perhaps +um it's uh will be will be exactly that + + align:start position:0% +um it's uh will be will be exactly that + + + align:start position:0% +um it's uh will be will be exactly that +that distance so + + align:start position:0% +that distance so + + + align:start position:0% +that distance so +um so good so then we just have to + + align:start position:0% +um so good so then we just have to + + + align:start position:0% +um so good so then we just have to +compute well we need to find a point q + + align:start position:0% +compute well we need to find a point q + + + align:start position:0% +compute well we need to find a point q +and we need to compute a component so we + + align:start position:0% +and we need to compute a component so we + + + align:start position:0% +and we need to compute a component so we +need any point on the plane so actually + + align:start position:0% +need any point on the plane so actually + + + align:start position:0% +need any point on the plane so actually +I'm going to walk back over here and and + + align:start position:0% +I'm going to walk back over here and and + + + align:start position:0% +I'm going to walk back over here and and +and to find a point on the the plane we + + align:start position:0% +and to find a point on the the plane we + + + align:start position:0% +and to find a point on the the plane we +we can just do this by looking at the at + + align:start position:0% +we can just do this by looking at the at + + + align:start position:0% +we can just do this by looking at the at +the equation so so one way to go about + + align:start position:0% +the equation so so one way to go about + + + align:start position:0% +the equation so so one way to go about +this for example is that you pick a pick + + align:start position:0% +this for example is that you pick a pick + + + align:start position:0% +this for example is that you pick a pick +a variable that appears in the equation + + align:start position:0% +a variable that appears in the equation + + + align:start position:0% +a variable that appears in the equation +so X appears in the equation and now if + + align:start position:0% +so X appears in the equation and now if + + + align:start position:0% +so X appears in the equation and now if +you you could just set all the other + + align:start position:0% +you you could just set all the other + + + align:start position:0% +you you could just set all the other +variables equal to zero and that'll give + + align:start position:0% +variables equal to zero and that'll give + + + align:start position:0% +variables equal to zero and that'll give +you something you can solve for x so so + + align:start position:0% +you something you can solve for x so so + + + align:start position:0% +you something you can solve for x so so +in particular you know there's a point + + align:start position:0% +in particular you know there's a point + + + align:start position:0% +in particular you know there's a point +on this plane with yal zal 0 that point + + align:start position:0% +on this plane with yal zal 0 that point + + + align:start position:0% +on this plane with yal zal 0 that point +has 2x = 4 so we can take for + + align:start position:0% + + + + align:start position:0% + +example Q to be the point two + + align:start position:0% +example Q to be the point two + + + align:start position:0% +example Q to be the point two +0 0 so this is a point on the plane um + + align:start position:0% +0 0 so this is a point on the plane um + + + align:start position:0% +0 0 so this is a point on the plane um +so this is our point on the plane and so + + align:start position:0% +so this is our point on the plane and so + + + align:start position:0% +so this is our point on the plane and so +we have what we want to do is we want to + + align:start position:0% +we have what we want to do is we want to + + + align:start position:0% +we have what we want to do is we want to +project so + + align:start position:0% +project so + + + align:start position:0% +project so +PQ the vector from P to Q we get by + + align:start position:0% +PQ the vector from P to Q we get by + + + align:start position:0% +PQ the vector from P to Q we get by +subtracting the coordinates of of P from + + align:start position:0% +subtracting the coordinates of of P from + + + align:start position:0% +subtracting the coordinates of of P from +those of q q minus P so this is the + + align:start position:0% +those of q q minus P so this is the + + + align:start position:0% +those of q q minus P so this is the +vector 2 0 Z and we want the component + + align:start position:0% +vector 2 0 Z and we want the component + + + align:start position:0% +vector 2 0 Z and we want the component +of PQ in the direction n so + + align:start position:0% +of PQ in the direction n so + + + align:start position:0% +of PQ in the direction n so +the distance in + + align:start position:0% + + + + align:start position:0% + +question is + + align:start position:0% + + + + align:start position:0% + +the and really when I say component in + + align:start position:0% +the and really when I say component in + + + align:start position:0% +the and really when I say component in +this case I mean the + + align:start position:0% + + + + align:start position:0% + +positive component I want because the + + align:start position:0% +positive component I want because the + + + align:start position:0% +positive component I want because the +distance has to be positive so if I get + + align:start position:0% +distance has to be positive so if I get + + + align:start position:0% +distance has to be positive so if I get +a a negative component I really want its + + align:start position:0% +a a negative component I really want its + + + align:start position:0% +a a negative component I really want its +absolute value here so the distance is + + align:start position:0% +absolute value here so the distance is + + + align:start position:0% +absolute value here so the distance is +the positive component in the direction + + align:start position:0% +the positive component in the direction + + + align:start position:0% +the positive component in the direction +n um so what's that equal to well it's + + align:start position:0% +n um so what's that equal to well it's + + + align:start position:0% +n um so what's that equal to well it's +just equal to the absolute value of so + + align:start position:0% +just equal to the absolute value of so + + + align:start position:0% +just equal to the absolute value of so +we know the component of of PQ in the + + align:start position:0% +we know the component of of PQ in the + + + align:start position:0% +we know the component of of PQ in the +direction n is what we get when we take + + align:start position:0% +direction n is what we get when we take + + + align:start position:0% +direction n is what we get when we take +PQ and we dot it with n divided by the + + align:start position:0% +PQ and we dot it with n divided by the + + + align:start position:0% +PQ and we dot it with n divided by the +length of + + align:start position:0% +length of + + + align:start position:0% +length of +N and then I to make sure it's positive + + align:start position:0% +N and then I to make sure it's positive + + + align:start position:0% +N and then I to make sure it's positive +at the end I want to throw in these + + align:start position:0% +at the end I want to throw in these + + + align:start position:0% +at the end I want to throw in these +absolute value sign + + align:start position:0% +absolute value sign + + + align:start position:0% +absolute value sign +so okay so this is and this is now you + + align:start position:0% +so okay so this is and this is now you + + + align:start position:0% +so okay so this is and this is now you +know we have we have our Vector PQ and + + align:start position:0% +know we have we have our Vector PQ and + + + align:start position:0% +know we have we have our Vector PQ and +we have our Vector n so it should be + + align:start position:0% +we have our Vector n so it should be + + + align:start position:0% +we have our Vector n so it should be +straightforward to to compute this final + + align:start position:0% +straightforward to to compute this final + + + align:start position:0% +straightforward to to compute this final +expression so we know that n is equal to + + align:start position:0% +expression so we know that n is equal to + + + align:start position:0% +expression so we know that n is equal to +21 minus 2 so the length of n which is + + align:start position:0% +21 minus 2 so the length of n which is + + + align:start position:0% +21 minus 2 so the length of n which is +in the denominator here is equal to the + + align:start position:0% +in the denominator here is equal to the + + + align:start position:0% +in the denominator here is equal to the +square < TK of 2^ 2 + 1^ 2 + - 2^ + + align:start position:0% +square < TK of 2^ 2 + 1^ 2 + - 2^ + + + align:start position:0% +square < TK of 2^ 2 + 1^ 2 + - 2^ +2 and in the numerator we have the + + align:start position:0% +2 and in the numerator we have the + + + align:start position:0% +2 and in the numerator we have the +absolute value of PQ + + align:start position:0% +absolute value of PQ + + + align:start position:0% +absolute value of PQ +n so pqn is going to be 2 * + + align:start position:0% +n so pqn is going to be 2 * + + + align:start position:0% +n so pqn is going to be 2 * + + align:start position:0% + + + align:start position:0% +plus 0 * 1 + 0 * + + align:start position:0% +plus 0 * 1 + 0 * + + + align:start position:0% +plus 0 * 1 + 0 * +-2 okay and so if we this is just a + + align:start position:0% +-2 okay and so if we this is just a + + + align:start position:0% +-2 okay and so if we this is just a +fraction bar here and so if we simplify + + align:start position:0% +fraction bar here and so if we simplify + + + align:start position:0% +fraction bar here and so if we simplify +that a little bit so up top we just have + + align:start position:0% +that a little bit so up top we just have + + + align:start position:0% +that a little bit so up top we just have +four plus 0 plus 0 is 4 and on the + + align:start position:0% +four plus 0 plus 0 is 4 and on the + + + align:start position:0% +four plus 0 plus 0 is 4 and on the +bottom we have the square Ro T of 2^ 2 + + + align:start position:0% +bottom we have the square Ro T of 2^ 2 + + + + align:start position:0% +bottom we have the square Ro T of 2^ 2 + +1 2 + 2^ 2 that's uh going to going to + + align:start position:0% +1 2 + 2^ 2 that's uh going to going to + + + align:start position:0% +1 2 + 2^ 2 that's uh going to going to +be < TK of 9 which is 3 so this is just + + align:start position:0% +be < TK of 9 which is 3 so this is just + + + align:start position:0% +be < TK of 9 which is 3 so this is just +equal to + + align:start position:0% +equal to + + + align:start position:0% +equal to +4/3 so there we go the distance in + + align:start position:0% +4/3 so there we go the distance in + + + align:start position:0% +4/3 so there we go the distance in +question is 4/3 the way we got it is we + + align:start position:0% +question is 4/3 the way we got it is we + + + align:start position:0% +question is 4/3 the way we got it is we +realized that that distance is just the + + align:start position:0% +realized that that distance is just the + + + align:start position:0% +realized that that distance is just the +component of any segment any Vector + + align:start position:0% +component of any segment any Vector + + + align:start position:0% +component of any segment any Vector +connecting our Point P to the plane in + + align:start position:0% +connecting our Point P to the plane in + + + align:start position:0% +connecting our Point P to the plane in +the direction of the normal so you + + align:start position:0% +the direction of the normal so you + + + align:start position:0% +the direction of the normal so you +choose any any any Vector PQ so you know + + align:start position:0% +choose any any any Vector PQ so you know + + + align:start position:0% +choose any any any Vector PQ so you know +you just have to come up with a with a + + align:start position:0% +you just have to come up with a with a + + + align:start position:0% +you just have to come up with a with a +point Q on the plane which you can do by + + align:start position:0% +point Q on the plane which you can do by + + + align:start position:0% +point Q on the plane which you can do by +inspection from the equation so that + + align:start position:0% +inspection from the equation so that + + + align:start position:0% +inspection from the equation so that +gives you a vector that gets you from P + + align:start position:0% +gives you a vector that gets you from P + + + align:start position:0% +gives you a vector that gets you from P +to some point on the plane and then you + + align:start position:0% +to some point on the plane and then you + + + align:start position:0% +to some point on the plane and then you +choose the component in the normal + + align:start position:0% +choose the component in the normal + + + align:start position:0% +choose the component in the normal +Direction and so once you do that you + + align:start position:0% +Direction and so once you do that you + + + align:start position:0% +Direction and so once you do that you +get you get this distance your answer so + + align:start position:0% +get you get this distance your answer so + + + align:start position:0% +get you get this distance your answer so +I'll end there \ No newline at end of file diff --git a/Siqu0aOOQCM.txt b/Siqu0aOOQCM.txt new file mode 100644 index 0000000000000000000000000000000000000000..cdf898bb206213c82584bcbda6adf136b834503e --- /dev/null +++ b/Siqu0aOOQCM.txt @@ -0,0 +1,7939 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +to view additional materials from + + align:start position:0% +to view additional materials from + + + align:start position:0% +to view additional materials from +hundreds of MIT courses visit MIT open + + align:start position:0% +hundreds of MIT courses visit MIT open + + + align:start position:0% +hundreds of MIT courses visit MIT open +courseware at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu so uh today's lecture is + + align:start position:0% +ocw.mit.edu so uh today's lecture is + + + align:start position:0% +ocw.mit.edu so uh today's lecture is +partly kind of picking up cleaning up + + align:start position:0% +partly kind of picking up cleaning up + + + align:start position:0% +partly kind of picking up cleaning up +some pieces left from uh one D problems + + align:start position:0% +some pieces left from uh one D problems + + + align:start position:0% +some pieces left from uh one D problems +3.1 was second order equations 3.2 was + + align:start position:0% +3.1 was second order equations 3.2 was + + + align:start position:0% +3.1 was second order equations 3.2 was +fourth order equations for beams and + + align:start position:0% +fourth order equations for beams and + + + align:start position:0% +fourth order equations for beams and +just a few more comments to make but + + align:start position:0% +just a few more comments to make but + + + align:start position:0% +just a few more comments to make but +then I do want to say something about + + align:start position:0% +then I do want to say something about + + + align:start position:0% +then I do want to say something about +splines however I I'm not that's that + + align:start position:0% +splines however I I'm not that's that + + + align:start position:0% +splines however I I'm not that's that +topic will really and it I included a a + + align:start position:0% +topic will really and it I included a a + + + align:start position:0% +topic will really and it I included a a +homework question that asked you to use + + align:start position:0% +homework question that asked you to use + + + align:start position:0% +homework question that asked you to use +the spind command and and get a result + + align:start position:0% +the spind command and and get a result + + + align:start position:0% +the spind command and and get a result +uh I'm not planning to make that a major + + align:start position:0% +uh I'm not planning to make that a major + + + align:start position:0% +uh I'm not planning to make that a major +you know a serious Topic in the course + + align:start position:0% +you know a serious Topic in the course + + + align:start position:0% +you know a serious Topic in the course +um in other words you're not like going + + align:start position:0% +um in other words you're not like going + + + align:start position:0% +um in other words you're not like going +to be responsible on exam for the + + align:start position:0% +to be responsible on exam for the + + + align:start position:0% +to be responsible on exam for the +discussion of splines but it's such a + + align:start position:0% +discussion of splines but it's such a + + + align:start position:0% +discussion of splines but it's such a +major uh event in major requirement in + + align:start position:0% +major uh event in major requirement in + + + align:start position:0% +major uh event in major requirement in +scientific Computing if you're given + + align:start position:0% +scientific Computing if you're given + + + align:start position:0% +scientific Computing if you're given +some values put a curve through them + + align:start position:0% +some values put a curve through them + + + align:start position:0% +some values put a curve through them +that I have to say something about that + + align:start position:0% +that I have to say something about that + + + align:start position:0% +that I have to say something about that +so that's interpr ation if I if because + + align:start position:0% +so that's interpr ation if I if because + + + align:start position:0% +so that's interpr ation if I if because +you you I mean you'll have this all the + + align:start position:0% +you you I mean you'll have this all the + + + align:start position:0% +you you I mean you'll have this all the +time if you you you your experiment + + align:start position:0% +time if you you you your experiment + + + align:start position:0% +time if you you you your experiment +produces some values at specific times + + align:start position:0% +produces some values at specific times + + + align:start position:0% +produces some values at specific times +or specific you know a finite number of + + align:start position:0% +or specific you know a finite number of + + + align:start position:0% +or specific you know a finite number of +values and you want to fit a curve + + align:start position:0% +values and you want to fit a curve + + + align:start position:0% +values and you want to fit a curve +through those points how do you do it so + + align:start position:0% +through those points how do you do it so + + + align:start position:0% +through those points how do you do it so +splines give a very very good answer and + + align:start position:0% +splines give a very very good answer and + + + align:start position:0% +splines give a very very good answer and +then with + + align:start position:0% +then with + + + align:start position:0% +then with +the the ne the next and big uh topic of + + align:start position:0% +the the ne the next and big uh topic of + + + align:start position:0% +the the ne the next and big uh topic of +the course uh we'll make a beginning on + + align:start position:0% +the course uh we'll make a beginning on + + + align:start position:0% +the course uh we'll make a beginning on +which is gradient Divergence leading to + + align:start position:0% +which is gradient Divergence leading to + + + align:start position:0% +which is gradient Divergence leading to +thees equation problems in + + align:start position:0% +thees equation problems in + + + align:start position:0% +thees equation problems in +2D so partial differential equations are + + align:start position:0% +2D so partial differential equations are + + + align:start position:0% +2D so partial differential equations are +going to show up okay but let me just so + + align:start position:0% +going to show up okay but let me just so + + + align:start position:0% +going to show up okay but let me just so +I some small points f first point about + + align:start position:0% +I some small points f first point about + + + align:start position:0% +I some small points f first point about +the mat lab homework for for Monday + + align:start position:0% +the mat lab homework for for Monday + + + align:start position:0% +the mat lab homework for for Monday +uh a question came by email uh should we + + align:start position:0% +uh a question came by email uh should we + + + align:start position:0% +uh a question came by email uh should we +really uh so I I put the + + align:start position:0% +really uh so I I put the + + + align:start position:0% +really uh so I I put the +spike at and also the jump in C in the + + align:start position:0% +spike at and also the jump in C in the + + + align:start position:0% +spike at and also the jump in C in the +coefficient at not at mesh point if + + align:start position:0% +coefficient at not at mesh point if + + + align:start position:0% +coefficient at not at mesh point if +you've started on that problem you + + align:start position:0% +you've started on that problem you + + + align:start position:0% +you've started on that problem you +probably noticed that and and + + align:start position:0% +probably noticed that and and + + + align:start position:0% +probably noticed that and and +uh um maybe a little swearing went on + + align:start position:0% +uh um maybe a little swearing went on + + + align:start position:0% +uh um maybe a little swearing went on +but uh cuz it makes it uh not so easy + + align:start position:0% +but uh cuz it makes it uh not so easy + + + align:start position:0% +but uh cuz it makes it uh not so easy +and then um the question came did I + + align:start position:0% +and then um the question came did I + + + align:start position:0% +and then um the question came did I +really expect you to to compute to to + + align:start position:0% +really expect you to to compute to to + + + align:start position:0% +really expect you to to compute to to +use the exact position and figure out + + align:start position:0% +use the exact position and figure out + + + align:start position:0% +use the exact position and figure out +the when you have some interal integrals + + align:start position:0% +the when you have some interal integrals + + + align:start position:0% +the when you have some interal integrals +to + + align:start position:0% +to + + + align:start position:0% +to +do uh they'll change at the place where + + align:start position:0% +do uh they'll change at the place where + + + align:start position:0% +do uh they'll change at the place where +C changes values where we have integrals + + align:start position:0% +C changes values where we have integrals + + + align:start position:0% +C changes values where we have integrals +of C if C has one of those jumps on the + + align:start position:0% +of C if C has one of those jumps on the + + + align:start position:0% +of C if C has one of those jumps on the +quiz the jump came right at a neat point + + align:start position:0% +quiz the jump came right at a neat point + + + align:start position:0% +quiz the jump came right at a neat point +so it was clear see was one on one side + + align:start position:0% +so it was clear see was one on one side + + + align:start position:0% +so it was clear see was one on one side +and two on the other now the jump is + + align:start position:0% +and two on the other now the jump is + + + align:start position:0% +and two on the other now the jump is +going to come at a in between point so + + align:start position:0% +going to come at a in between point so + + + align:start position:0% +going to come at a in between point so +the answer is yes uh I uh well I had a + + align:start position:0% +the answer is yes uh I uh well I had a + + + align:start position:0% +the answer is yes uh I uh well I had a +nice email this morning from somebody + + align:start position:0% +nice email this morning from somebody + + + align:start position:0% +nice email this morning from somebody +who has done that mat lab homework and + + align:start position:0% +who has done that mat lab homework and + + + align:start position:0% +who has done that mat lab homework and +he said + + align:start position:0% +he said + + + align:start position:0% +he said +quote uh it's a good problem I learned + + align:start position:0% +quote uh it's a good problem I learned + + + align:start position:0% +quote uh it's a good problem I learned +more from it than I did from the other + + align:start position:0% +more from it than I did from the other + + + align:start position:0% +more from it than I did from the other +problems in the piece + + align:start position:0% +problems in the piece + + + align:start position:0% +problems in the piece +so I'll blame it on + + align:start position:0% +so I'll blame it on + + + align:start position:0% +so I'll blame it on +him I'll stay with that problem and ask + + align:start position:0% +him I'll stay with that problem and ask + + + align:start position:0% +him I'll stay with that problem and ask +you to do your best to to deal with the + + align:start position:0% +you to do your best to to deal with the + + + align:start position:0% +you to do your best to to deal with the +calculation of the it's second order and + + align:start position:0% +calculation of the it's second order and + + + align:start position:0% +calculation of the it's second order and +I Ed linear elements I didn't want to + + align:start position:0% +I Ed linear elements I didn't want to + + + align:start position:0% +I Ed linear elements I didn't want to +push you up to these cubic elements even + + align:start position:0% +push you up to these cubic elements even + + + align:start position:0% +push you up to these cubic elements even +though those would be give much better + + align:start position:0% +though those would be give much better + + + align:start position:0% +though those would be give much better +accuracy the one reason I didn't put the + + align:start position:0% +accuracy the one reason I didn't put the + + + align:start position:0% +accuracy the one reason I didn't put the +spike and the jump right at the node is + + align:start position:0% +spike and the jump right at the node is + + + align:start position:0% +spike and the jump right at the node is +that if I + + align:start position:0% +that if I + + + align:start position:0% +that if I +did the find out element Sol solution + + align:start position:0% +did the find out element Sol solution + + + align:start position:0% +did the find out element Sol solution +would be exactly right because the + + align:start position:0% +would be exactly right because the + + + align:start position:0% +would be exactly right because the +correct solution is going to be + + align:start position:0% +correct solution is going to be + + + align:start position:0% +correct solution is going to be +piecewise linear and if I put the the + + align:start position:0% +piecewise linear and if I put the the + + + align:start position:0% +piecewise linear and if I put the the +breaks in the in between pieces right at + + align:start position:0% +breaks in the in between pieces right at + + + align:start position:0% +breaks in the in between pieces right at +node points well then I have a function + + align:start position:0% +node points well then I have a function + + + align:start position:0% +node points well then I have a function +that's in my finite element space in my + + align:start position:0% +that's in my finite element space in my + + + align:start position:0% +that's in my finite element space in my +linear space so it'll come out exactly + + align:start position:0% +linear space so it'll come out exactly + + + align:start position:0% +linear space so it'll come out exactly +so I thought well let's at least have + + align:start position:0% +so I thought well let's at least have + + + align:start position:0% +so I thought well let's at least have +some chance to + + align:start position:0% +some chance to + + + align:start position:0% +some chance to +see the error between the finite element + + align:start position:0% +see the error between the finite element + + + align:start position:0% +see the error between the finite element +solution and the exact one do you see + + align:start position:0% +solution and the exact one do you see + + + align:start position:0% +solution and the exact one do you see +what I'm saying I'm just anticipating + + align:start position:0% +what I'm saying I'm just anticipating + + + align:start position:0% +what I'm saying I'm just anticipating +that the result the the exact solution + + align:start position:0% +that the result the the exact solution + + + align:start position:0% +that the result the the exact solution +will let's see there was something + + align:start position:0% +will let's see there was something + + + align:start position:0% +will let's see there was something +happened at 1/3 and something happened + + align:start position:0% +happened at 1/3 and something happened + + + align:start position:0% +happened at 1/3 and something happened +at 2/3 and I I'm afraid I don't remember + + align:start position:0% +at 2/3 and I I'm afraid I don't remember + + + align:start position:0% +at 2/3 and I I'm afraid I don't remember +the boundary conditions does anybody + + align:start position:0% +the boundary conditions does anybody + + + align:start position:0% +the boundary conditions does anybody +remember what I took for boundary + + align:start position:0% +remember what I took for boundary + + + align:start position:0% +remember what I took for boundary +conditions probably free fixed or + + align:start position:0% +conditions probably free fixed or + + + align:start position:0% +conditions probably free fixed or +something so maybe if it was free fixed + + align:start position:0% +something so maybe if it was free fixed + + + align:start position:0% +something so maybe if it was free fixed +probably uh the uh solution would be + + align:start position:0% +probably uh the uh solution would be + + + align:start position:0% +probably uh the uh solution would be +maybe something like that I don't know + + align:start position:0% +maybe something like that I don't know + + + align:start position:0% +maybe something like that I don't know +whatever piecewise linear with brakes + + align:start position:0% +whatever piecewise linear with brakes + + + align:start position:0% +whatever piecewise linear with brakes +where there's a jump in C or where the + + align:start position:0% +where there's a jump in C or where the + + + align:start position:0% +where there's a jump in C or where the +point load is hitting uh oh yeah uh I + + align:start position:0% +point load is hitting uh oh yeah uh I + + + align:start position:0% +point load is hitting uh oh yeah uh I +don't know if that picture is accurate + + align:start position:0% +don't know if that picture is accurate + + + align:start position:0% +don't know if that picture is accurate +but you my point was if I chose those + + align:start position:0% +but you my point was if I chose those + + + align:start position:0% +but you my point was if I chose those +points to be also mesh points then the + + align:start position:0% +points to be also mesh points then the + + + align:start position:0% +points to be also mesh points then the +finite element solution would would be + + align:start position:0% +finite element solution would would be + + + align:start position:0% +finite element solution would would be +exact and we wouldn't learn anything + + align:start position:0% +exact and we wouldn't learn anything + + + align:start position:0% +exact and we wouldn't learn anything +about accuracy okay so anyway for that + + align:start position:0% +about accuracy okay so anyway for that + + + align:start position:0% +about accuracy okay so anyway for that +mat lab problem I'm hoping you can do it + + align:start position:0% +mat lab problem I'm hoping you can do it + + + align:start position:0% +mat lab problem I'm hoping you can do it +uh you can you can do the integrals + + align:start position:0% +uh you can you can do the integrals + + + align:start position:0% +uh you can you can do the integrals +which will mean noticing which + + align:start position:0% +which will mean noticing which + + + align:start position:0% +which will mean noticing which +integral if that doesn't fall if so if + + align:start position:0% +integral if that doesn't fall if so if + + + align:start position:0% +integral if that doesn't fall if so if +the mesh points are like this then you + + align:start position:0% +the mesh points are like this then you + + + align:start position:0% +the mesh points are like this then you +do have in in the integral in the finite + + align:start position:0% +do have in in the integral in the finite + + + align:start position:0% +do have in in the integral in the finite +element integral over that mesh over + + align:start position:0% +element integral over that mesh over + + + align:start position:0% +element integral over that mesh over +that interval you're going to have to + + align:start position:0% +that interval you're going to have to + + + align:start position:0% +that interval you're going to have to +split it into two pieces that's that's + + align:start position:0% +split it into two pieces that's that's + + + align:start position:0% +split it into two pieces that's that's +it yeah just so so see if you can do + + align:start position:0% +it yeah just so so see if you can do + + + align:start position:0% +it yeah just so so see if you can do +that split do the split into two pieces + + align:start position:0% +that split do the split into two pieces + + + align:start position:0% +that split do the split into two pieces +okay so that's a comment on that + + align:start position:0% +okay so that's a comment on that + + + align:start position:0% +okay so that's a comment on that +homework okay what else do I need to + + align:start position:0% +homework okay what else do I need to + + + align:start position:0% +homework okay what else do I need to +comment on when I'm sort of catching up + + align:start position:0% +comment on when I'm sort of catching up + + + align:start position:0% +comment on when I'm sort of catching up +here oh about boundary + + align:start position:0% +here oh about boundary + + + align:start position:0% +here oh about boundary +conditions uh I thought I would just + + align:start position:0% +conditions uh I thought I would just + + + align:start position:0% +conditions uh I thought I would just +repeat clearly on the board uh the + + align:start position:0% +repeat clearly on the board uh the + + + align:start position:0% +repeat clearly on the board uh the +the uh + + align:start position:0% +the uh + + + align:start position:0% +the uh +rules about and the difference between + + align:start position:0% +rules about and the difference between + + + align:start position:0% +rules about and the difference between +fixed and free when we're doing this + + align:start position:0% +fixed and free when we're doing this + + + align:start position:0% +fixed and free when we're doing this +uh uh weak form approach to the uh to + + align:start position:0% +uh uh weak form approach to the uh to + + + align:start position:0% +uh uh weak form approach to the uh to +the problem and and then I gave the + + align:start position:0% +the problem and and then I gave the + + + align:start position:0% +the problem and and then I gave the +other names a fixed condition in in the + + align:start position:0% +other names a fixed condition in in the + + + align:start position:0% +other names a fixed condition in in the +in this Theory it's often called an + + align:start position:0% +in this Theory it's often called an + + + align:start position:0% +in this Theory it's often called an +essential boundary condition but many + + align:start position:0% +essential boundary condition but many + + + align:start position:0% +essential boundary condition but many +people just name d CL as the as the + + align:start position:0% +people just name d CL as the as the + + + align:start position:0% +people just name d CL as the as the +person's name that's associated with + + align:start position:0% +person's name that's associated with + + + align:start position:0% +person's name that's associated with +such conditions like U of 0 equals 0 so + + align:start position:0% +such conditions like U of 0 equals 0 so + + + align:start position:0% +such conditions like U of 0 equals 0 so +right fixed and then free conditions are + + align:start position:0% +right fixed and then free conditions are + + + align:start position:0% +right fixed and then free conditions are +natural conditions in the finite element + + align:start position:0% +natural conditions in the finite element + + + align:start position:0% +natural conditions in the finite element +method and that that means that we don't + + align:start position:0% +method and that that means that we don't + + + align:start position:0% +method and that that means that we don't +have to impose them right I I discussed + + align:start position:0% +have to impose them right I I discussed + + + align:start position:0% +have to impose them right I I discussed +this in the earlier lecture I just + + align:start position:0% +this in the earlier lecture I just + + + align:start position:0% +this in the earlier lecture I just +thought I'd bring it back here because + + align:start position:0% +thought I'd bring it back here because + + + align:start position:0% +thought I'd bring it back here because +uh um it's easy to describe in one line + + align:start position:0% +uh um it's easy to describe in one line + + + align:start position:0% +uh um it's easy to describe in one line +now somebody asked on Wednesday a good + + align:start position:0% +now somebody asked on Wednesday a good + + + align:start position:0% +now somebody asked on Wednesday a good +question suppose the the NOA suppose the + + align:start position:0% +question suppose the the NOA suppose the + + + align:start position:0% +question suppose the the NOA suppose the +suppose U + + align:start position:0% +suppose U + + + align:start position:0% +suppose U +Prime is + + align:start position:0% +Prime is + + + align:start position:0% +Prime is +given but not given a zero so suppose + + align:start position:0% +given but not given a zero so suppose + + + align:start position:0% +given but not given a zero so suppose +there's the the suppose we have have a + + align:start position:0% +there's the the suppose we have have a + + + align:start position:0% +there's the the suppose we have have a +condition like U Prime equals a let's + + align:start position:0% +condition like U Prime equals a let's + + + align:start position:0% +condition like U Prime equals a let's +say what to do so so I'll just put + + align:start position:0% +say what to do so so I'll just put + + + align:start position:0% +say what to do so so I'll just put +question mark there how do I deal with a + + align:start position:0% +question mark there how do I deal with a + + + align:start position:0% +question mark there how do I deal with a +a how does the how do I how does the + + align:start position:0% +a how does the how do I how does the + + + align:start position:0% +a how does the how do I how does the +weak form and the guran approach deal + + align:start position:0% +weak form and the guran approach deal + + + align:start position:0% +weak form and the guran approach deal +with a + + align:start position:0% +with a + + + align:start position:0% +with a +nonzero + + align:start position:0% +nonzero + + + align:start position:0% +nonzero +uh natural condition a nonzero noyman + + align:start position:0% +uh natural condition a nonzero noyman + + + align:start position:0% +uh natural condition a nonzero noyman +condition that would be the natural that + + align:start position:0% +condition that would be the natural that + + + align:start position:0% +condition that would be the natural that +would be the right words so this would + + align:start position:0% +would be the right words so this would + + + align:start position:0% +would be the right words so this would +be in a second order problem this would + + align:start position:0% +be in a second order problem this would + + + align:start position:0% +be in a second order problem this would +be a a noyon condition and I'm thinking + + align:start position:0% +be a a noyon condition and I'm thinking + + + align:start position:0% +be a a noyon condition and I'm thinking +what what do you do if a isn't zero + + align:start position:0% +what what do you do if a isn't zero + + + align:start position:0% +what what do you do if a isn't zero +somehow that has to show up in your + + align:start position:0% +somehow that has to show up in your + + + align:start position:0% +somehow that has to show up in your +finite element equations right so I + + align:start position:0% +finite element equations right so I + + + align:start position:0% +finite element equations right so I +guess the right way is to go back to + + align:start position:0% +guess the right way is to go back to + + + align:start position:0% +guess the right way is to go back to +where they came from so do you remember + + align:start position:0% +where they came from so do you remember + + + align:start position:0% +where they came from so do you remember +how the weak form came I I took the took + + align:start position:0% +how the weak form came I I took the took + + + align:start position:0% +how the weak form came I I took the took +the differential equation I multiplied + + align:start position:0% +the differential equation I multiplied + + + align:start position:0% +the differential equation I multiplied +by any test function and I integrated by + + align:start position:0% +by any test function and I integrated by + + + align:start position:0% +by any test function and I integrated by +parts that's where the weak form started + + align:start position:0% +parts that's where the weak form started + + + align:start position:0% +parts that's where the weak form started +so the integration by parts gave me this + + align:start position:0% +so the integration by parts gave me this + + + align:start position:0% +so the integration by parts gave me this +this + + align:start position:0% +this + + + align:start position:0% +this +nice + + align:start position:0% +nice + + + align:start position:0% +nice +uh + + align:start position:0% +uh + + + align:start position:0% +uh +symmetric uh uh integral s sort of it's + + align:start position:0% +symmetric uh uh integral s sort of it's + + + align:start position:0% +symmetric uh uh integral s sort of it's +symmetric in u and v it only requires + + align:start position:0% +symmetric in u and v it only requires + + + align:start position:0% +symmetric in u and v it only requires +one derivative of U so that I'm allowed + + align:start position:0% +one derivative of U so that I'm allowed + + + align:start position:0% +one derivative of U so that I'm allowed +to use uh uh hat functions and I'm + + align:start position:0% +to use uh uh hat functions and I'm + + + align:start position:0% +to use uh uh hat functions and I'm +allowed to use hat functions for V + + align:start position:0% +allowed to use hat functions for V + + + align:start position:0% +allowed to use hat functions for V +because their derivatives have just a + + align:start position:0% +because their derivatives have just a + + + align:start position:0% +because their derivatives have just a +jump and a jump function I can integrate + + align:start position:0% +jump and a jump function I can integrate + + + align:start position:0% +jump and a jump function I can integrate +no + + align:start position:0% +no + + + align:start position:0% +no +problem now what about + + align:start position:0% +problem now what about + + + align:start position:0% +problem now what about +this this U Prime equal a and I guess + + align:start position:0% +this this U Prime equal a and I guess + + + align:start position:0% +this this U Prime equal a and I guess +we're seeing it + + align:start position:0% +we're seeing it + + + align:start position:0% +we're seeing it +there if U Prime was Zero if we had a + + align:start position:0% +there if U Prime was Zero if we had a + + + align:start position:0% +there if U Prime was Zero if we had a +totally free n u Prime was Zero nothing + + align:start position:0% +totally free n u Prime was Zero nothing + + + align:start position:0% +totally free n u Prime was Zero nothing +happening there then that term would + + align:start position:0% +happening there then that term would + + + align:start position:0% +happening there then that term would +drop out of the integration by parts and + + align:start position:0% +drop out of the integration by parts and + + + align:start position:0% +drop out of the integration by parts and +you see why I don't have to impose + + align:start position:0% +you see why I don't have to impose + + + align:start position:0% +you see why I don't have to impose +anything on V because that term is + + align:start position:0% +anything on V because that term is + + + align:start position:0% +anything on V because that term is +already accounted for by the U Prime + + align:start position:0% +already accounted for by the U Prime + + + align:start position:0% +already accounted for by the U Prime +going away now what about if U Prime + + align:start position:0% +going away now what about if U Prime + + + align:start position:0% +going away now what about if U Prime +isn't is is is given but not given zero + + align:start position:0% +isn't is is is given but not given zero + + + align:start position:0% +isn't is is is given but not given zero +suppose it's given the value a all I + + align:start position:0% +suppose it's given the value a all I + + + align:start position:0% +suppose it's given the value a all I +want to say + + align:start position:0% +want to say + + + align:start position:0% +want to say +is then I have to I have to This this + + align:start position:0% +is then I have to I have to This this + + + align:start position:0% +is then I have to I have to This this +term is is uh has to stay I have to pay + + align:start position:0% +term is is uh has to stay I have to pay + + + align:start position:0% +term is is uh has to stay I have to pay +attention to it what what happens when + + align:start position:0% +attention to it what what happens when + + + align:start position:0% +attention to it what what happens when +gurin takes over gurin will try will put + + align:start position:0% +gurin takes over gurin will try will put + + + align:start position:0% +gurin takes over gurin will try will put +in one of his test functions maybe I + + align:start position:0% +in one of his test functions maybe I + + + align:start position:0% +in one of his test functions maybe I +just indicate that by changing the V to + + align:start position:0% +just indicate that by changing the V to + + + align:start position:0% +just indicate that by changing the V to +a cap V it'll be one of them there will + + align:start position:0% +a cap V it'll be one of them there will + + + align:start position:0% +a cap V it'll be one of them there will +be n of + + align:start position:0% +be n of + + + align:start position:0% +be n of +them each one of each VI each test guy + + align:start position:0% +them each one of each VI each test guy + + + align:start position:0% +them each one of each VI each test guy +gives me an equation and of course U is + + align:start position:0% +gives me an equation and of course U is + + + align:start position:0% +gives me an equation and of course U is +now going + + align:start position:0% +now going + + + align:start position:0% +now going +to the gurin idea is instead of any U I + + align:start position:0% +to the gurin idea is instead of any U I + + + align:start position:0% +to the gurin idea is instead of any U I +only have Capital U's combinations of + + align:start position:0% +only have Capital U's combinations of + + + align:start position:0% +only have Capital U's combinations of +these Fe + + align:start position:0% + + + + align:start position:0% + +I'm not going to say anything very big + + align:start position:0% +I'm not going to say anything very big + + + align:start position:0% +I'm not going to say anything very big +here or very clear all I want to say is + + align:start position:0% +here or very clear all I want to say is + + + align:start position:0% +here or very clear all I want to say is +that if U Prime is given at an end point + + align:start position:0% +that if U Prime is given at an end point + + + align:start position:0% +that if U Prime is given at an end point +then and given by a then when then this + + align:start position:0% +then and given by a then when then this + + + align:start position:0% +then and given by a then when then this +is part you know this whole stuff is + + align:start position:0% +is part you know this whole stuff is + + + align:start position:0% +is part you know this whole stuff is +equaling something with an F right FV DX + + align:start position:0% +equaling something with an F right FV DX + + + align:start position:0% +equaling something with an F right FV DX +X I should remember the other side of + + align:start position:0% +X I should remember the other side of + + + align:start position:0% +X I should remember the other side of +the equation If U Prime is given then + + align:start position:0% +the equation If U Prime is given then + + + align:start position:0% +the equation If U Prime is given then +then C at that end point times the given + + align:start position:0% +then C at that end point times the given + + + align:start position:0% +then C at that end point times the given +value of a times the + + align:start position:0% +value of a times the + + + align:start position:0% +value of a times the +V will be whatever value of V that is + + align:start position:0% +V will be whatever value of V that is + + + align:start position:0% +V will be whatever value of V that is +will show up in equation I this will be + + align:start position:0% +will show up in equation I this will be + + + align:start position:0% +will show up in equation I this will be +a + + align:start position:0% +a + + + align:start position:0% +a +term that'll be a term that goes on the + + align:start position:0% +term that'll be a term that goes on the + + + align:start position:0% +term that'll be a term that goes on the +right hand side that's what I all I'm + + align:start position:0% +right hand side that's what I all I'm + + + align:start position:0% +right hand side that's what I all I'm +saying and all you would expect + + align:start position:0% +saying and all you would expect + + + align:start position:0% +saying and all you would expect +that anytime I have a you know I'm I'm + + align:start position:0% +that anytime I have a you know I'm I'm + + + align:start position:0% +that anytime I have a you know I'm I'm +given some data I'm given some nonzero + + align:start position:0% +given some data I'm given some nonzero + + + align:start position:0% +given some data I'm given some nonzero +boundary conditions or I'm given some + + align:start position:0% +boundary conditions or I'm given some + + + align:start position:0% +boundary conditions or I'm given some +nonzero F in the inside that stuff is + + align:start position:0% +nonzero F in the inside that stuff is + + + align:start position:0% +nonzero F in the inside that stuff is +going to show up on the right hand side + + align:start position:0% +going to show up on the right hand side + + + align:start position:0% +going to show up on the right hand side +it'll show up as part of the big of the + + align:start position:0% +it'll show up as part of the big of the + + + align:start position:0% +it'll show up as part of the big of the +of the it'll show up as part of the F + + align:start position:0% +of the it'll show up as part of the F + + + align:start position:0% +of the it'll show up as part of the F +the the vector of these uh uh so up to + + align:start position:0% +the the vector of these uh uh so up to + + + align:start position:0% +the the vector of these uh uh so up to +now F has just come from Little F ofx + + align:start position:0% +now F has just come from Little F ofx + + + align:start position:0% +now F has just come from Little F ofx +integrated against V and all I'm saying + + align:start position:0% +integrated against V and all I'm saying + + + align:start position:0% +integrated against V and all I'm saying +is that uh if we had one of these guys + + align:start position:0% +is that uh if we had one of these guys + + + align:start position:0% +is that uh if we had one of these guys +then that would contribute to Big F + + align:start position:0% +then that would contribute to Big F + + + align:start position:0% +then that would contribute to Big F +also yeah you can see it's not beautiful + + align:start position:0% +also yeah you can see it's not beautiful + + + align:start position:0% +also yeah you can see it's not beautiful +it's it's uh it's uh but we have to + + align:start position:0% +it's it's uh it's uh but we have to + + + align:start position:0% +it's it's uh it's uh but we have to +realize what we would do okay maybe uh + + align:start position:0% +realize what we would do okay maybe uh + + + align:start position:0% +realize what we would do okay maybe uh +that's not my favorite topic but I'll + + align:start position:0% +that's not my favorite topic but I'll + + + align:start position:0% +that's not my favorite topic but I'll +just + + align:start position:0% +just + + + align:start position:0% +just +say quit on that one and uh not + + align:start position:0% +say quit on that one and uh not + + + align:start position:0% +say quit on that one and uh not +expecting you to do problems or anything + + align:start position:0% +expecting you to do problems or anything + + + align:start position:0% +expecting you to do problems or anything +that that involv that possibility just + + align:start position:0% +that that involv that possibility just + + + align:start position:0% +that that involv that possibility just +to see that it could happen okay quit + + align:start position:0% +to see that it could happen okay quit + + + align:start position:0% +to see that it could happen okay quit +now + + align:start position:0% +now + + + align:start position:0% +now +interpolation all + + align:start position:0% +interpolation all + + + align:start position:0% +interpolation all +right so I guess if I had to en list + + align:start position:0% +right so I guess if I had to en list + + + align:start position:0% +right so I guess if I had to en list +problems that people face all the time + + align:start position:0% +problems that people face all the time + + + align:start position:0% +problems that people face all the time +and need numerical guidance on + + align:start position:0% +and need numerical guidance on + + + align:start position:0% +and need numerical guidance on +this is one of them and and so let's say + + align:start position:0% +this is one of them and and so let's say + + + align:start position:0% +this is one of them and and so let's say +we're in + + align:start position:0% +we're in + + + align:start position:0% +we're in +1D 1D is certainly a lot easier so + + align:start position:0% +1D 1D is certainly a lot easier so + + + align:start position:0% +1D 1D is certainly a lot easier so +suppose I have this could be like I'll + + align:start position:0% +suppose I have this could be like I'll + + + align:start position:0% +suppose I have this could be like I'll +call this x just to have a name for the + + align:start position:0% +call this x just to have a name for the + + + align:start position:0% +call this x just to have a name for the +variable suppose I have some + + align:start position:0% + + + + align:start position:0% + +values say six + + align:start position:0% +values say six + + + align:start position:0% +values say six +values and I want to + + align:start position:0% +values and I want to + + + align:start position:0% +values and I want to +put uh and then measured them I've + + align:start position:0% +put uh and then measured them I've + + + align:start position:0% +put uh and then measured them I've +worked hard to find those six values but + + align:start position:0% +worked hard to find those six values but + + + align:start position:0% +worked hard to find those six values but +now you may say well so I'm I'm thinking + + align:start position:0% +now you may say well so I'm I'm thinking + + + align:start position:0% +now you may say well so I'm I'm thinking +I have some function uh F ofx + + align:start position:0% +I have some function uh F ofx + + + align:start position:0% +I have some function uh F ofx +here but right now I don't have a + + align:start position:0% +here but right now I don't have a + + + align:start position:0% +here but right now I don't have a +function right now I just have six + + align:start position:0% +function right now I just have six + + + align:start position:0% +function right now I just have six +values of that function you know what is + + align:start position:0% +values of that function you know what is + + + align:start position:0% +values of that function you know what is +the uh stretching constant what is the + + align:start position:0% +the uh stretching constant what is the + + + align:start position:0% +the uh stretching constant what is the +like the C + + align:start position:0% +like the C + + + align:start position:0% +like the C +ofx if you had if you had a physical + + align:start position:0% +ofx if you had if you had a physical + + + align:start position:0% +ofx if you had if you had a physical +expr experiment with a with a um uh you + + align:start position:0% +expr experiment with a with a um uh you + + + align:start position:0% +expr experiment with a with a um uh you +know an actual spring you might measure + + align:start position:0% +know an actual spring you might measure + + + align:start position:0% +know an actual spring you might measure +you might put on different uh forces and + + align:start position:0% +you might put on different uh forces and + + + align:start position:0% +you might put on different uh forces and +measure the stretching and have six + + align:start position:0% +measure the stretching and have six + + + align:start position:0% +measure the stretching and have six +values of that so this what how how do I + + align:start position:0% +values of that so this what how how do I + + + align:start position:0% +values of that so this what how how do I +fit those with a curve in other words + + align:start position:0% +fit those with a curve in other words + + + align:start position:0% +fit those with a curve in other words +how do I how do I know interpolation + + align:start position:0% +how do I how do I know interpolation + + + align:start position:0% +how do I how do I know interpolation +means inter means is sort of asking what + + align:start position:0% +means inter means is sort of asking what + + + align:start position:0% +means inter means is sort of asking what +about between the + + align:start position:0% +about between the + + + align:start position:0% +about between the +points what about between what value + + align:start position:0% +points what about between what value + + + align:start position:0% +points what about between what value +should it have + + align:start position:0% +should it have + + + align:start position:0% +should it have +there okay well there's a simple one + + align:start position:0% +there okay well there's a simple one + + + align:start position:0% +there okay well there's a simple one +simple rule would be just just uh + + align:start position:0% +simple rule would be just just uh + + + align:start position:0% +simple rule would be just just uh +interpolate linearly + + align:start position:0% +interpolate linearly + + + align:start position:0% +interpolate linearly +between + + align:start position:0% +between + + + align:start position:0% +between +okay + + align:start position:0% +okay + + + align:start position:0% +okay +that's that's certainly pretty stable it + + align:start position:0% +that's that's certainly pretty stable it + + + align:start position:0% +that's that's certainly pretty stable it +will not get out of control but it's not + + align:start position:0% +will not get out of control but it's not + + + align:start position:0% +will not get out of control but it's not +very accurate it's not it's it's has the + + align:start position:0% +very accurate it's not it's it's has the + + + align:start position:0% +very accurate it's not it's it's has the +that + + align:start position:0% +that + + + align:start position:0% +that +if there for the function that's + + align:start position:0% +if there for the function that's + + + align:start position:0% +if there for the function that's +probably lying behind this this isn't + + align:start position:0% +probably lying behind this this isn't + + + align:start position:0% +probably lying behind this this isn't +that great a + + align:start position:0% +that great a + + + align:start position:0% +that great a +representation okay you say I want + + align:start position:0% +representation okay you say I want + + + align:start position:0% +representation okay you say I want +something + + align:start position:0% +something + + + align:start position:0% +something +smoother well another idea that + + align:start position:0% +smoother well another idea that + + + align:start position:0% +smoother well another idea that +naturally comes up + + align:start position:0% +naturally comes up + + + align:start position:0% +naturally comes up +is second sort of The Other Extreme + + align:start position:0% +is second sort of The Other Extreme + + + align:start position:0% +is second sort of The Other Extreme +would + + align:start position:0% +would + + + align:start position:0% +would +be so that was completely local just + + align:start position:0% +be so that was completely local just + + + align:start position:0% +be so that was completely local just +every two values determine the broken + + align:start position:0% +every two values determine the broken + + + align:start position:0% +every two values determine the broken +line second idea that's completely + + align:start position:0% +line second idea that's completely + + + align:start position:0% +line second idea that's completely +natural would be fit a + + align:start position:0% +natural would be fit a + + + align:start position:0% +natural would be fit a +polinomial fit a polinomial through + + align:start position:0% +polinomial fit a polinomial through + + + align:start position:0% +polinomial fit a polinomial through +those points and then you have a nice + + align:start position:0% +those points and then you have a nice + + + align:start position:0% +those points and then you have a nice +totally simple function nice curve and + + align:start position:0% +totally simple function nice curve and + + + align:start position:0% +totally simple function nice curve and +uh so what degree polinomial would we be + + align:start position:0% +uh so what degree polinomial would we be + + + align:start position:0% +uh so what degree polinomial would we be +looking for here if I have six points I + + align:start position:0% +looking for here if I have six points I + + + align:start position:0% +looking for here if I have six points I +could fit a polom of + + align:start position:0% +could fit a polom of + + + align:start position:0% +could fit a polom of +degree what do you say I I want I want + + align:start position:0% +degree what do you say I I want I want + + + align:start position:0% +degree what do you say I I want I want +to have six coefficients so I can m get + + align:start position:0% +to have six coefficients so I can m get + + + align:start position:0% +to have six coefficients so I can m get +six equations to make the make the + + align:start position:0% +six equations to make the make the + + + align:start position:0% +six equations to make the make the +polinomial go through those six points + + align:start position:0% +polinomial go through those six points + + + align:start position:0% +polinomial go through those six points +so my polinomial P of X my which + + align:start position:0% +so my polinomial P of X my which + + + align:start position:0% +so my polinomial P of X my which +actually goes through those points would + + align:start position:0% +actually goes through those points would + + + align:start position:0% +actually goes through those points would +be some polinomial of the form it's got + + align:start position:0% +be some polinomial of the form it's got + + + align:start position:0% +be some polinomial of the form it's got +some constant term and it's got some + + align:start position:0% +some constant term and it's got some + + + align:start position:0% +some constant term and it's got some +linear term and how far am I going to + + align:start position:0% +linear term and how far am I going to + + + align:start position:0% +linear term and how far am I going to +go fifth right that'll give me six + + align:start position:0% +go fifth right that'll give me six + + + align:start position:0% +go fifth right that'll give me six +coefficients okay so I could fo put a + + align:start position:0% +coefficients okay so I could fo put a + + + align:start position:0% +coefficients okay so I could fo put a +fifth degree polinomial that gives me a + + align:start position:0% +fifth degree polinomial that gives me a + + + align:start position:0% +fifth degree polinomial that gives me a +A1 up to A5 + + align:start position:0% +A1 up to A5 + + + align:start position:0% +A1 up to A5 +six coefficients through six + + align:start position:0% +six coefficients through six + + + align:start position:0% +six coefficients through six +points well six isn't too + + align:start position:0% +points well six isn't too + + + align:start position:0% +points well six isn't too +bad but if six if six became + + align:start position:0% + + + + align:start position:0% + +60 don't do it that's the message don't + + align:start position:0% +60 don't do it that's the message don't + + + align:start position:0% +60 don't do it that's the message don't +do it don't I if if if I'm going on up + + align:start position:0% +do it don't I if if if I'm going on up + + + align:start position:0% +do it don't I if if if I'm going on up +to say I have an a59 x to the + + align:start position:0% +to say I have an a59 x to the + + + align:start position:0% +to say I have an a59 x to the +59th and that and that fits my 60 points + + align:start position:0% +59th and that and that fits my 60 points + + + align:start position:0% +59th and that and that fits my 60 points +and and you say well well look I've got + + align:start position:0% +and and you say well well look I've got + + + align:start position:0% +and and you say well well look I've got +60 values that should be way better than + + align:start position:0% +60 values that should be way better than + + + align:start position:0% +60 values that should be way better than +having only six but the polinomial that + + align:start position:0% +having only six but the polinomial that + + + align:start position:0% +having only six but the polinomial that +would come out of that even if these + + align:start position:0% +would come out of that even if these + + + align:start position:0% +would come out of that even if these +even if these values were on a pretty + + align:start position:0% +even if these values were on a pretty + + + align:start position:0% +even if these values were on a pretty +were pretty smooth the polom that fits + + align:start position:0% +were pretty smooth the polom that fits + + + align:start position:0% +were pretty smooth the polom that fits +well I have to put in a whole lot more + + align:start position:0% +well I have to put in a whole lot more + + + align:start position:0% +well I have to put in a whole lot more +to get 60 and I won't try the polinomial + + align:start position:0% +to get 60 and I won't try the polinomial + + + align:start position:0% +to get 60 and I won't try the polinomial +would go + + align:start position:0% +would go + + + align:start position:0% +would go +crazy right I mean it would just I I + + align:start position:0% +crazy right I mean it would just I I + + + align:start position:0% +crazy right I mean it would just I I +don't can I just draw something crazy I + + align:start position:0% +don't can I just draw something crazy I + + + align:start position:0% +don't can I just draw something crazy I +mean + + align:start position:0% +mean + + + align:start position:0% +mean +whatever it's it's unstable it's it and + + align:start position:0% +whatever it's it's unstable it's it and + + + align:start position:0% +whatever it's it's unstable it's it and +there are classical examples of that in + + align:start position:0% +there are classical examples of that in + + + align:start position:0% +there are classical examples of that in +fact the the famous example is the + + align:start position:0% +fact the the famous example is the + + + align:start position:0% +fact the the famous example is the +function 1 over 1 + + + align:start position:0% + + + + align:start position:0% + +X2 and later in a there's a figure in + + align:start position:0% +X2 and later in a there's a figure in + + + align:start position:0% +X2 and later in a there's a figure in +the book I think it's in section + + align:start position:0% +the book I think it's in section + + + align:start position:0% +the book I think it's in section +5.4 uh which + + align:start position:0% +5.4 uh which + + + align:start position:0% +5.4 uh which +shows uh the result of that's I mean + + align:start position:0% +shows uh the result of that's I mean + + + align:start position:0% +shows uh the result of that's I mean +that's a terrific function it it has no + + align:start position:0% +that's a terrific function it it has no + + + align:start position:0% +that's a terrific function it it has no +no it's infinitely differentiable it's + + align:start position:0% +no it's infinitely differentiable it's + + + align:start position:0% +no it's infinitely differentiable it's +it's I would even call it an analytic + + align:start position:0% +it's I would even call it an analytic + + + align:start position:0% +it's I would even call it an analytic +function it's great but if I try to fit + + align:start position:0% +function it's great but if I try to fit + + + align:start position:0% +function it's great but if I try to fit +it with a high degree polom at at + + align:start position:0% +it with a high degree polom at at + + + align:start position:0% +it with a high degree polom at at +points that polinomial gets out of hand + + align:start position:0% +points that polinomial gets out of hand + + + align:start position:0% +points that polinomial gets out of hand +right and the and a figure is in there's + + align:start position:0% +right and the and a figure is in there's + + + align:start position:0% +right and the and a figure is in there's +a figure there okay + + align:start position:0% + + + + align:start position:0% + +so uh + + align:start position:0% +so uh + + + align:start position:0% +so uh +I mean this I mean mat + + align:start position:0% +I mean this I mean mat + + + align:start position:0% +I mean this I mean mat +lab or any Computing system would have a + + align:start position:0% +lab or any Computing system would have a + + + align:start position:0% +lab or any Computing system would have a +would have a a + + align:start position:0% +would have a a + + + align:start position:0% +would have a a +subroutine that does interpolation and + + align:start position:0% +subroutine that does interpolation and + + + align:start position:0% +subroutine that does interpolation and +this is this was named after lron so + + align:start position:0% +this is this was named after lron so + + + align:start position:0% +this is this was named after lron so +this is called lron interpolation + + align:start position:0% +this is called lron interpolation + + + align:start position:0% +this is called lron interpolation +fitting a + + align:start position:0% +fitting a + + + align:start position:0% +fitting a +polom and if the if the degree is small + + align:start position:0% +polom and if the if the degree is small + + + align:start position:0% +polom and if the if the degree is small +and maybe maybe degree five would be + + align:start position:0% +and maybe maybe degree five would be + + + align:start position:0% +and maybe maybe degree five would be +okay then that that's a re that's an + + align:start position:0% +okay then that that's a re that's an + + + align:start position:0% +okay then that that's a re that's an +important uh thing to be able to do and + + align:start position:0% +important uh thing to be able to do and + + + align:start position:0% +important uh thing to be able to do and +and it's uh in other words you're + + align:start position:0% +and it's uh in other words you're + + + align:start position:0% +and it's uh in other words you're +finding these six coefficients from + + align:start position:0% +finding these six coefficients from + + + align:start position:0% +finding these six coefficients from +these six Heights you've got some 6x6 + + align:start position:0% +these six Heights you've got some 6x6 + + + align:start position:0% +these six Heights you've got some 6x6 +Matrix that connects the six Heights to + + align:start position:0% +Matrix that connects the six Heights to + + + align:start position:0% +Matrix that connects the six Heights to +the six + + align:start position:0% +the six + + + align:start position:0% +the six +A's but when you get up to 60 that + + align:start position:0% +A's but when you get up to 60 that + + + align:start position:0% +A's but when you get up to 60 that +Matrix stops behaving well it's uh + + align:start position:0% +Matrix stops behaving well it's uh + + + align:start position:0% +Matrix stops behaving well it's uh +becomes very ill conditioned and you're + + align:start position:0% +becomes very ill conditioned and you're + + + align:start position:0% +becomes very ill conditioned and you're +you're coefficients go all over the + + align:start position:0% +you're coefficients go all over the + + + align:start position:0% +you're coefficients go all over the +place okay so that my question is what + + align:start position:0% +place okay so that my question is what + + + align:start position:0% +place okay so that my question is what +do you do + + align:start position:0% +do you do + + + align:start position:0% +do you do +and one answer one good answer is fit + + align:start position:0% +and one answer one good answer is fit + + + align:start position:0% +and one answer one good answer is fit +those points not with straight lines + + align:start position:0% +those points not with straight lines + + + align:start position:0% +those points not with straight lines +that's too crude not with a single polom + + align:start position:0% +that's too crude not with a single polom + + + align:start position:0% +that's too crude not with a single polom +that's too unstable but fit it with + + align:start position:0% +that's too unstable but fit it with + + + align:start position:0% +that's too unstable but fit it with +splines so so interpolation by + + align:start position:0% +splines so so interpolation by + + + align:start position:0% +splines so so interpolation by +splines okay so that's where it's just + + align:start position:0% +splines okay so that's where it's just + + + align:start position:0% +splines okay so that's where it's just +sort of appearing in in this uh section + + align:start position:0% +sort of appearing in in this uh section + + + align:start position:0% +sort of appearing in in this uh section +3.2 because those + + align:start position:0% +3.2 because those + + + align:start position:0% +3.2 because those +are I'm I have and I mean by that and + + align:start position:0% +are I'm I have and I mean by that and + + + align:start position:0% +are I'm I have and I mean by that and +people often do mean when they say + + align:start position:0% +people often do mean when they say + + + align:start position:0% +people often do mean when they say +spline they mean cubic + + align:start position:0% +spline they mean cubic + + + align:start position:0% +spline they mean cubic +spline so so it's + + align:start position:0% +spline so so it's + + + align:start position:0% +spline so so it's +a you could have splines of other + + align:start position:0% +a you could have splines of other + + + align:start position:0% +a you could have splines of other +degrees but often the sort of the + + align:start position:0% +degrees but often the sort of the + + + align:start position:0% +degrees but often the sort of the +Natural Choice is the cubic so can I + + align:start position:0% +Natural Choice is the cubic so can I + + + align:start position:0% +Natural Choice is the cubic so can I +just briefly describe what uh that does + + align:start position:0% +just briefly describe what uh that does + + + align:start position:0% +just briefly describe what uh that does +what the cub bline would be + + align:start position:0% +what the cub bline would be + + + align:start position:0% +what the cub bline would be +like so let me draw in again these six + + align:start position:0% +like so let me draw in again these six + + + align:start position:0% +like so let me draw in again these six +points that I'm going to + + align:start position:0% +points that I'm going to + + + align:start position:0% +points that I'm going to +fit and just say for these few minutes + + align:start position:0% +fit and just say for these few minutes + + + align:start position:0% +fit and just say for these few minutes +what's a cubic + + align:start position:0% +what's a cubic + + + align:start position:0% +what's a cubic +spot I I got I touched on that uh + + align:start position:0% +spot I I got I touched on that uh + + + align:start position:0% +spot I I got I touched on that uh +Wednesday and now I just want to say a + + align:start position:0% +Wednesday and now I just want to say a + + + align:start position:0% +Wednesday and now I just want to say a +little bit more and then the homework + + align:start position:0% +little bit more and then the homework + + + align:start position:0% +little bit more and then the homework +asked you to + + align:start position:0% +asked you to + + + align:start position:0% +asked you to +actually uh do it with uh a a part + + align:start position:0% +actually uh do it with uh a a part + + + align:start position:0% +actually uh do it with uh a a part +values of a particular function and see + + align:start position:0% +values of a particular function and see + + + align:start position:0% +values of a particular function and see +how close does the cubic spline come to + + align:start position:0% +how close does the cubic spline come to + + + align:start position:0% +how close does the cubic spline come to +the to the uh given function okay so + + align:start position:0% +the to the uh given function okay so + + + align:start position:0% +the to the uh given function okay so +what's a cubic + + align:start position:0% +what's a cubic + + + align:start position:0% +what's a cubic +spline what does that word spline what + + align:start position:0% +spline what does that word spline what + + + align:start position:0% +spline what does that word spline what +should that mean in your mind so a cubic + + align:start position:0% +should that mean in your mind so a cubic + + + align:start position:0% +should that mean in your mind so a cubic +spline is a cubic in each + + align:start position:0% +spline is a cubic in each + + + align:start position:0% +spline is a cubic in each +piece a cubic in each + + align:start position:0% +piece a cubic in each + + + align:start position:0% +piece a cubic in each +piece now we we've met cubics in each + + align:start position:0% +piece now we we've met cubics in each + + + align:start position:0% +piece now we we've met cubics in each +piece as finite elements and and part of + + align:start position:0% +piece as finite elements and and part of + + + align:start position:0% +piece as finite elements and and part of +this short discussion is to keep those + + align:start position:0% +this short discussion is to keep those + + + align:start position:0% +this short discussion is to keep those +two slightly different ideas + + align:start position:0% +two slightly different ideas + + + align:start position:0% +two slightly different ideas +separate the finite element + + align:start position:0% +separate the finite element + + + align:start position:0% +separate the finite element +idea was also peie wise + + align:start position:0% +idea was also peie wise + + + align:start position:0% +idea was also peie wise +cubic and but it used values and + + align:start position:0% +cubic and but it used values and + + + align:start position:0% +cubic and but it used values and +slopes so it was completely local if I + + align:start position:0% +slopes so it was completely local if I + + + align:start position:0% +slopes so it was completely local if I +had a value as I have here six values + + align:start position:0% +had a value as I have here six values + + + align:start position:0% +had a value as I have here six values +and if I also had six slopes if I knew + + align:start position:0% +and if I also had six slopes if I knew + + + align:start position:0% +and if I also had six slopes if I knew +the slopes then I would use those find + + align:start position:0% +the slopes then I would use those find + + + align:start position:0% +the slopes then I would use those find +those cubic elements and I would fit + + align:start position:0% +those cubic elements and I would fit + + + align:start position:0% +those cubic elements and I would fit +a if I knew the height and slope there + + align:start position:0% +a if I knew the height and slope there + + + align:start position:0% +a if I knew the height and slope there +and I knew the height and slope there + + align:start position:0% +and I knew the height and slope there + + + align:start position:0% +and I knew the height and slope there +there would be exactly one cubic because + + align:start position:0% +there would be exactly one cubic because + + + align:start position:0% +there would be exactly one cubic because +I I would have four conditions two + + align:start position:0% +I I would have four conditions two + + + align:start position:0% +I I would have four conditions two +conditions there two conditions there + + align:start position:0% +conditions there two conditions there + + + align:start position:0% +conditions there two conditions there +would be four I could fit a cubic + + align:start position:0% +would be four I could fit a cubic + + + align:start position:0% +would be four I could fit a cubic +between another cubic there another + + align:start position:0% +between another cubic there another + + + align:start position:0% +between another cubic there another +cubic there and + + align:start position:0% +cubic there and + + + align:start position:0% +cubic there and +because I'm using the same slope from + + align:start position:0% +because I'm using the same slope from + + + align:start position:0% +because I'm using the same slope from +the left and from the right the slope + + align:start position:0% +the left and from the right the slope + + + align:start position:0% +the left and from the right the slope +would be good it would be continuous the + + align:start position:0% +would be good it would be continuous the + + + align:start position:0% +would be good it would be continuous the +second derivative the curving the + + align:start position:0% +second derivative the curving the + + + align:start position:0% +second derivative the curving the +curvature would not be continuous with + + align:start position:0% +curvature would not be continuous with + + + align:start position:0% +curvature would not be continuous with +those cubic elements and that's the + + align:start position:0% +those cubic elements and that's the + + + align:start position:0% +those cubic elements and that's the +difference so the difference is splines + + align:start position:0% +difference so the difference is splines + + + align:start position:0% +difference so the difference is splines +have + + align:start position:0% +have + + + align:start position:0% +have +continuous the no jump in let me just + + align:start position:0% +continuous the no jump in let me just + + + align:start position:0% +continuous the no jump in let me just +put it this way no jump + + align:start position:0% + + + + align:start position:0% + +in in the function I'll use S maybe for + + align:start position:0% +in in the function I'll use S maybe for + + + align:start position:0% +in in the function I'll use S maybe for +spline no jump in its slope and no jump + + align:start position:0% +spline no jump in its slope and no jump + + + align:start position:0% +spline no jump in its slope and no jump +in the second derivative so that's the + + align:start position:0% +in the second derivative so that's the + + + align:start position:0% +in the second derivative so that's the +that's the difference that that the + + align:start position:0% +that's the difference that that the + + + align:start position:0% +that's the difference that that the +spline + + align:start position:0% +spline + + + align:start position:0% +spline +functions the only jumps you see for + + align:start position:0% +functions the only jumps you see for + + + align:start position:0% +functions the only jumps you see for +those are jumps in the third + + align:start position:0% +those are jumps in the third + + + align:start position:0% +those are jumps in the third +derivative and uh so that makes it + + align:start position:0% +derivative and uh so that makes it + + + align:start position:0% +derivative and uh so that makes it +extremely smooth so so if I just try to + + align:start position:0% +extremely smooth so so if I just try to + + + align:start position:0% +extremely smooth so so if I just try to +draw now what a spline would do it'll go + + align:start position:0% +draw now what a spline would do it'll go + + + align:start position:0% +draw now what a spline would do it'll go +through those points coming out of the + + align:start position:0% +through those points coming out of the + + + align:start position:0% +through those points coming out of the +spline fit mat lab command and it will + + align:start position:0% +spline fit mat lab command and it will + + + align:start position:0% +spline fit mat lab command and it will +be well it'll be as smooth as I drew it + + align:start position:0% +be well it'll be as smooth as I drew it + + + align:start position:0% +be well it'll be as smooth as I drew it +uh there there'll be there is a change + + align:start position:0% +uh there there'll be there is a change + + + align:start position:0% +uh there there'll be there is a change +in the third derivative at these + + align:start position:0% +in the third derivative at these + + + align:start position:0% +in the third derivative at these +points and + + align:start position:0% +points and + + + align:start position:0% +points and +um actually do you you have you ever + + align:start position:0% +um actually do you you have you ever + + + align:start position:0% +um actually do you you have you ever +seen this word spine before uh came out + + align:start position:0% +seen this word spine before uh came out + + + align:start position:0% +seen this word spine before uh came out +of Naval + + align:start position:0% +of Naval + + + align:start position:0% +of Naval +engineering + + align:start position:0% + + + + align:start position:0% + +um when uh people were were designing + + align:start position:0% +um when uh people were were designing + + + align:start position:0% +um when uh people were were designing +the uh the shape of the + + align:start position:0% +the uh the shape of the + + + align:start position:0% +the uh the shape of the +ship uh for a naval architect is fitting + + align:start position:0% +ship uh for a naval architect is fitting + + + align:start position:0% +ship uh for a naval architect is fitting +the proposed shape of a ship by this was + + align:start position:0% +the proposed shape of a ship by this was + + + align:start position:0% +the proposed shape of a ship by this was +before mat lab before uh yeah before + + align:start position:0% +before mat lab before uh yeah before + + + align:start position:0% +before mat lab before uh yeah before +life started uh uh uh they had little uh + + align:start position:0% +life started uh uh uh they had little uh + + + align:start position:0% +life started uh uh uh they had little uh +physical slightly + + align:start position:0% +physical slightly + + + align:start position:0% +physical slightly +bendable uh + + align:start position:0% +bendable uh + + + align:start position:0% +bendable uh +um I'll call them splines I guess that's + + align:start position:0% +um I'll call them splines I guess that's + + + align:start position:0% +um I'll call them splines I guess that's +what they were that that's where the + + align:start position:0% +what they were that that's where the + + + align:start position:0% +what they were that that's where the +word came from some physical thing which + + align:start position:0% +word came from some physical thing which + + + align:start position:0% +word came from some physical thing which +was like a curve that you used I don't + + align:start position:0% +was like a curve that you used I don't + + + align:start position:0% +was like a curve that you used I don't +know if you guys ever did draw like + + align:start position:0% +know if you guys ever did draw like + + + align:start position:0% +know if you guys ever did draw like +mechanical drawing that was a freshman + + align:start position:0% +mechanical drawing that was a freshman + + + align:start position:0% +mechanical drawing that was a freshman +subject when I came to MIT mechanical + + align:start position:0% +subject when I came to MIT mechanical + + + align:start position:0% +subject when I came to MIT mechanical +drawing I was terrible terrible at + + align:start position:0% +drawing I was terrible terrible at + + + align:start position:0% +drawing I was terrible terrible at +mechanical + + align:start position:0% +mechanical + + + align:start position:0% +mechanical +drawing but uh I don't know I I had a + + align:start position:0% +drawing but uh I don't know I I had a + + + align:start position:0% +drawing but uh I don't know I I had a +friend uh who helped I mean just like I + + align:start position:0% +friend uh who helped I mean just like I + + + align:start position:0% +friend uh who helped I mean just like I +I help probably helped him at some other + + align:start position:0% +I help probably helped him at some other + + + align:start position:0% +I help probably helped him at some other +course anyway whatever uh so there were + + align:start position:0% +course anyway whatever uh so there were + + + align:start position:0% +course anyway whatever uh so there were +physical things curves that you used to + + align:start position:0% +physical things curves that you used to + + + align:start position:0% +physical things curves that you used to +use and these spline curves were used + + align:start position:0% +use and these spline curves were used + + + align:start position:0% +use and these spline curves were used +and maybe still are used by Naval + + align:start position:0% +and maybe still are used by Naval + + + align:start position:0% +and maybe still are used by Naval +architects in in in creating a drawing + + align:start position:0% +architects in in in creating a drawing + + + align:start position:0% +architects in in in creating a drawing +but I'm assuming that those things are + + align:start position:0% +but I'm assuming that those things are + + + align:start position:0% +but I'm assuming that those things are +now all computerized and and the spline + + align:start position:0% +now all computerized and and the spline + + + align:start position:0% +now all computerized and and the spline +command is used anyway the result is + + align:start position:0% +command is used anyway the result is + + + align:start position:0% +command is used anyway the result is +that now I have to draw one picture of a + + align:start position:0% +that now I have to draw one picture of a + + + align:start position:0% +that now I have to draw one picture of a +spline of the of the most important + + align:start position:0% +spline of the of the most important + + + align:start position:0% +spline of the of the most important +spine and then I'm done with + + align:start position:0% +spine and then I'm done with + + + align:start position:0% +spine and then I'm done with +splines yeah so + + align:start position:0% +splines yeah so + + + align:start position:0% +splines yeah so +so what I'm going to draw is now a b + + align:start position:0% + + + + align:start position:0% + +splot and and and and and that that's + + align:start position:0% +splot and and and and and that that's + + + align:start position:0% +splot and and and and and that that's +that's a Basics bline that's a it could + + align:start position:0% +that's a Basics bline that's a it could + + + align:start position:0% +that's a Basics bline that's a it could +be it could be one of our functions it + + align:start position:0% +be it could be one of our functions it + + + align:start position:0% +be it could be one of our functions it +could be one of our functions f of x one + + align:start position:0% +could be one of our functions f of x one + + + align:start position:0% +could be one of our functions f of x one +of our one of our trial functions it + + align:start position:0% +of our one of our trial functions it + + + align:start position:0% +of our one of our trial functions it +could be and let me comment on that so + + align:start position:0% +could be and let me comment on that so + + + align:start position:0% +could be and let me comment on that so +so I'll let me remind myself good or bad + + align:start position:0% +so I'll let me remind myself good or bad + + + align:start position:0% +so I'll let me remind myself good or bad +to to with a question and let me try to + + align:start position:0% +to to with a question and let me try to + + + align:start position:0% +to to with a question and let me try to +answer that but let me first draw the + + align:start position:0% +answer that but let me first draw the + + + align:start position:0% +answer that but let me first draw the +the be spine okay + + align:start position:0% +the be spine okay + + + align:start position:0% +the be spine okay +so it's like a hat function that's + + align:start position:0% +so it's like a hat function that's + + + align:start position:0% +so it's like a hat function that's +that's actually that a hat function is + + align:start position:0% +that's actually that a hat function is + + + align:start position:0% +that's actually that a hat function is +a linear spline a hat function is the + + align:start position:0% +a linear spline a hat function is the + + + align:start position:0% +a linear spline a hat function is the +that that lowlevel spline that's linear + + align:start position:0% +that that lowlevel spline that's linear + + + align:start position:0% +that that lowlevel spline that's linear +between pieces now the B + + align:start position:0% +between pieces now the B + + + align:start position:0% +between pieces now the B +spline is going to be is going to have + + align:start position:0% +spline is going to be is going to have + + + align:start position:0% +spline is going to be is going to have +the value one + + align:start position:0% +the value one + + + align:start position:0% +the value one +there it's going to have no jump in the + + align:start position:0% +there it's going to have no jump in the + + + align:start position:0% +there it's going to have no jump in the +function so the function will go through + + align:start position:0% +function so the function will go through + + + align:start position:0% +function so the function will go through +there no jump in the slope no jump in + + align:start position:0% +there no jump in the slope no jump in + + + align:start position:0% +there no jump in the slope no jump in +the second + + align:start position:0% +the second + + + align:start position:0% +the second +derivative and I want to get down to + + align:start position:0% +derivative and I want to get down to + + + align:start position:0% +derivative and I want to get down to +zero I want to get down to zero here and + + align:start position:0% +zero I want to get down to zero here and + + + align:start position:0% +zero I want to get down to zero here and +so it it's it's it's sort of it's just + + align:start position:0% +so it it's it's it's sort of it's just + + + align:start position:0% +so it it's it's it's sort of it's just +it's I want it to be as local as I can + + align:start position:0% +it's I want it to be as local as I can + + + align:start position:0% +it's I want it to be as local as I can +make it so I want it to get to + + align:start position:0% + + + + align:start position:0% + +zero here's the + + align:start position:0% +zero here's the + + + align:start position:0% +zero here's the +point I can't get down to with those + + align:start position:0% +point I can't get down to with those + + + align:start position:0% +point I can't get down to with those +with those uh + + align:start position:0% +with those uh + + + align:start position:0% +with those uh +cubic finite elements I got them down to + + align:start position:0% +cubic finite elements I got them down to + + + align:start position:0% +cubic finite elements I got them down to +zero they came in here with zero slope + + align:start position:0% +zero they came in here with zero slope + + + align:start position:0% +zero they came in here with zero slope +and then they continued to zero no + + align:start position:0% +and then they continued to zero no + + + align:start position:0% +and then they continued to zero no +problem with if I'm if I'm wanting the + + align:start position:0% +problem with if I'm if I'm wanting the + + + align:start position:0% +problem with if I'm if I'm wanting the +second derivative + + align:start position:0% +second derivative + + + align:start position:0% +second derivative +also to to to meet it to be zero to be + + align:start position:0% +also to to to meet it to be zero to be + + + align:start position:0% +also to to to meet it to be zero to be +continuous I won't be able to do it in + + align:start position:0% +continuous I won't be able to do it in + + + align:start position:0% +continuous I won't be able to do it in +one interval it's going to take + + align:start position:0% +one interval it's going to take + + + align:start position:0% +one interval it's going to take +me a total of four intervals this one + + align:start position:0% +me a total of four intervals this one + + + align:start position:0% +me a total of four intervals this one +can come down to some point here where + + align:start position:0% +can come down to some point here where + + + align:start position:0% +can come down to some point here where +it meets where another cubic starts and + + align:start position:0% +it meets where another cubic starts and + + + align:start position:0% +it meets where another cubic starts and +this is the Let Me Maybe I should drew + + align:start position:0% +this is the Let Me Maybe I should drew + + + align:start position:0% +this is the Let Me Maybe I should drew +the one here going up you remember the + + align:start position:0% +the one here going up you remember the + + + align:start position:0% +the one here going up you remember the +good the allowed cubic spine would be an + + align:start position:0% +good the allowed cubic spine would be an + + + align:start position:0% +good the allowed cubic spine would be an +a sort of an X Cub over 6 or some some + + align:start position:0% +a sort of an X Cub over 6 or some some + + + align:start position:0% +a sort of an X Cub over 6 or some some +multiple of X Cub I don't know what + + align:start position:0% +multiple of X Cub I don't know what + + + align:start position:0% +multiple of X Cub I don't know what +multiple it'll take maybe X Cub over 6 + + align:start position:0% +multiple it'll take maybe X Cub over 6 + + + align:start position:0% +multiple it'll take maybe X Cub over 6 +is right it'll come up to some point + + align:start position:0% +is right it'll come up to some point + + + align:start position:0% +is right it'll come up to some point +here now I've got to get it I've got to + + align:start position:0% +here now I've got to get it I've got to + + + align:start position:0% +here now I've got to get it I've got to +get it sort + + align:start position:0% +get it sort + + + align:start position:0% +get it sort +of beginning to curve downwards so I'm + + align:start position:0% +of beginning to curve downwards so I'm + + + align:start position:0% +of beginning to curve downwards so I'm +going to have to change the third + + align:start position:0% +going to have to change the third + + + align:start position:0% +going to have to change the third +derivative change to another cubic + + align:start position:0% +derivative change to another cubic + + + align:start position:0% +derivative change to another cubic +there change to another cubic there and + + align:start position:0% +there change to another cubic there and + + + align:start position:0% +there change to another cubic there and +a final cubic here so there is a picture + + align:start position:0% +a final cubic here so there is a picture + + + align:start position:0% +a final cubic here so there is a picture +of a b spline and we could figure + + align:start position:0% +of a b spline and we could figure + + + align:start position:0% +of a b spline and we could figure +out by requiring all these + + align:start position:0% +out by requiring all these + + + align:start position:0% +out by requiring all these +continuity conditions we could figure + + align:start position:0% +continuity conditions we could figure + + + align:start position:0% +continuity conditions we could figure +out the formulas for the cubic in these + + align:start position:0% +out the formulas for the cubic in these + + + align:start position:0% +out the formulas for the cubic in these +four pieces and it would be symetric of + + align:start position:0% +four pieces and it would be symetric of + + + align:start position:0% +four pieces and it would be symetric of +course ac across that center point but + + align:start position:0% +course ac across that center point but + + + align:start position:0% +course ac across that center point but +uh I think I won't try to do it I'll + + align:start position:0% +uh I think I won't try to do it I'll + + + align:start position:0% +uh I think I won't try to do it I'll +just leave that idea then the the the + + align:start position:0% +just leave that idea then the the the + + + align:start position:0% +just leave that idea then the the the +book there's a figure in the book + + align:start position:0% +book there's a figure in the book + + + align:start position:0% +book there's a figure in the book +showing a picture of the beast + + align:start position:0% +showing a picture of the beast + + + align:start position:0% +showing a picture of the beast +bline so so those are + + align:start position:0% +bline so so those are + + + align:start position:0% +bline so so those are +functions extremely valuable in this + + align:start position:0% +functions extremely valuable in this + + + align:start position:0% +functions extremely valuable in this +interpolation problem because all + + align:start position:0% +interpolation problem because all + + + align:start position:0% +interpolation problem because all +splines are combinations of B splines + + align:start position:0% +splines are combinations of B splines + + + align:start position:0% +splines are combinations of B splines +yeah now let me pull this topic together + + align:start position:0% +yeah now let me pull this topic together + + + align:start position:0% +yeah now let me pull this topic together +every + + align:start position:0% +every + + + align:start position:0% +every +spline every spline + + align:start position:0% +spline every spline + + + align:start position:0% +spline every spline +function is some + + align:start position:0% +function is some + + + align:start position:0% +function is some +combination of these Beast + + align:start position:0% +combination of these Beast + + + align:start position:0% +combination of these Beast +spines let bi of X be the one centered + + align:start position:0% +spines let bi of X be the one centered + + + align:start position:0% +spines let bi of X be the one centered +on node I + + align:start position:0% +on node I + + + align:start position:0% +on node I +and then there's a neighbor centered on + + align:start position:0% +and then there's a neighbor centered on + + + align:start position:0% +and then there's a neighbor centered on +node I + one and a a neighbor to the + + align:start position:0% +node I + one and a a neighbor to the + + + align:start position:0% +node I + one and a a neighbor to the +left centered on node I minus one what's + + align:start position:0% +left centered on node I minus one what's + + + align:start position:0% +left centered on node I minus one what's +the point the point is that at node at a + + align:start position:0% +the point the point is that at node at a + + + align:start position:0% +the point the point is that at node at a +typical node i+ + + align:start position:0% + + + + align:start position:0% + +one how three three of these functions + + align:start position:0% +one how three three of these functions + + + align:start position:0% +one how three three of these functions +will will be non zero with these very + + align:start position:0% +will will be non zero with these very + + + align:start position:0% +will will be non zero with these very +local hat functions at that node the + + align:start position:0% +local hat functions at that node the + + + align:start position:0% +local hat functions at that node the +only hat that was the only one of the Fe + + align:start position:0% +only hat that was the only one of the Fe + + + align:start position:0% +only hat that was the only one of the Fe +functions that wasn't zero is the one + + align:start position:0% +functions that wasn't zero is the one + + + align:start position:0% +functions that wasn't zero is the one +I've drawn all the others were were zero + + align:start position:0% +I've drawn all the others were were zero + + + align:start position:0% +I've drawn all the others were were zero +there right all the other + + align:start position:0% +there right all the other + + + align:start position:0% +there right all the other +hats were zero there was just the one + + align:start position:0% +hats were zero there was just the one + + + align:start position:0% +hats were zero there was just the one +but now there'll be a beast blind + + align:start position:0% +but now there'll be a beast blind + + + align:start position:0% +but now there'll be a beast blind +starting from here going up to here + + align:start position:0% +starting from here going up to here + + + align:start position:0% +starting from here going up to here +coming down from here there'll be a be + + align:start position:0% +coming down from here there'll be a be + + + align:start position:0% +coming down from here there'll be a be +there'll be the Beast blind starting + + align:start position:0% +there'll be the Beast blind starting + + + align:start position:0% +there'll be the Beast blind starting +from here going up to here up down so on + + align:start position:0% +from here going up to here up down so on + + + align:start position:0% +from here going up to here up down so on +so at a typical node I'm getting the one + + align:start position:0% +so at a typical node I'm getting the one + + + align:start position:0% +so at a typical node I'm getting the one +centered at that + + align:start position:0% +centered at that + + + align:start position:0% +centered at that +node and also the one to the left which + + align:start position:0% +node and also the one to the left which + + + align:start position:0% +node and also the one to the left which +is on its way down and also the one to + + align:start position:0% +is on its way down and also the one to + + + align:start position:0% +is on its way down and also the one to +the right which is on its way up in + + align:start position:0% +the right which is on its way up in + + + align:start position:0% +the right which is on its way up in +other + + align:start position:0% +other + + + align:start position:0% +other +words it's not as local as the other + + align:start position:0% +words it's not as local as the other + + + align:start position:0% +words it's not as local as the other +construction uh and that's and that's + + align:start position:0% +construction uh and that's and that's + + + align:start position:0% +construction uh and that's and that's +why so good good uh I would say good + + align:start position:0% +why so good good uh I would say good + + + align:start position:0% +why so good good uh I would say good +because it's + + align:start position:0% + + + + align:start position:0% + +smooth but bad because it's not fully + + align:start position:0% +smooth but bad because it's not fully + + + align:start position:0% +smooth but bad because it's not fully +local not completely local it it's + + align:start position:0% +local not completely local it it's + + + align:start position:0% +local not completely local it it's +reasonably local in that there are only + + align:start position:0% +reasonably local in that there are only + + + align:start position:0% +reasonably local in that there are only +three functions that are affecting these + + align:start position:0% +three functions that are affecting these + + + align:start position:0% +three functions that are affecting these +points if I used those + + align:start position:0% +points if I used those + + + align:start position:0% +points if I used those +pols they weren't local at all all the + + align:start position:0% +pols they weren't local at all all the + + + align:start position:0% +pols they weren't local at all all the +points + + align:start position:0% +points + + + align:start position:0% +points +uh it was a typical x to the 5ifth is + + align:start position:0% +uh it was a typical x to the 5ifth is + + + align:start position:0% +uh it was a typical x to the 5ifth is +not zero at any of the points these + + align:start position:0% +not zero at any of the points these + + + align:start position:0% +not zero at any of the points these +Beast lines are zero at a lot of points + + align:start position:0% +Beast lines are zero at a lot of points + + + align:start position:0% +Beast lines are zero at a lot of points +but three of them + + align:start position:0% +but three of them + + + align:start position:0% +but three of them +one two and three will be nonzero at a + + align:start position:0% +one two and three will be nonzero at a + + + align:start position:0% +one two and three will be nonzero at a +typical mesh Point + + align:start position:0% +typical mesh Point + + + align:start position:0% +typical mesh Point +okay in so so they're not popular as a + + align:start position:0% +okay in so so they're not popular as a + + + align:start position:0% +okay in so so they're not popular as a +result for finite elements and I'm just + + align:start position:0% +result for finite elements and I'm just + + + align:start position:0% +result for finite elements and I'm just +wanting to be sure you make the + + align:start position:0% +wanting to be sure you make the + + + align:start position:0% +wanting to be sure you make the +distinction they're very popular for the + + align:start position:0% +distinction they're very popular for the + + + align:start position:0% +distinction they're very popular for the +interpolation job they're very popular + + align:start position:0% +interpolation job they're very popular + + + align:start position:0% +interpolation job they're very popular +for the interpolation job I I I just + + align:start position:0% +for the interpolation job I I I just + + + align:start position:0% +for the interpolation job I I I just +I've got some comination of these at at + + align:start position:0% +I've got some comination of these at at + + + align:start position:0% +I've got some comination of these at at +particular mesh points is supposed to + + align:start position:0% +particular mesh points is supposed to + + + align:start position:0% +particular mesh points is supposed to +agree with F at those mesh points this + + align:start position:0% +agree with F at those mesh points this + + + align:start position:0% +agree with F at those mesh points this +is my this is my system to solve I've + + align:start position:0% +is my this is my system to solve I've + + + align:start position:0% +is my this is my system to solve I've +create these functions these be blindes + + align:start position:0% +create these functions these be blindes + + + align:start position:0% +create these functions these be blindes +I given an F at typical points and I + + align:start position:0% +I given an F at typical points and I + + + align:start position:0% +I given an F at typical points and I +choose a combination which matches F at + + align:start position:0% +choose a combination which matches F at + + + align:start position:0% +choose a combination which matches F at +those points yeah + + align:start position:0% +those points yeah + + + align:start position:0% +those points yeah +okay is there a question or a discussion + + align:start position:0% +okay is there a question or a discussion + + + align:start position:0% +okay is there a question or a discussion +on this it's a I always you know I I I + + align:start position:0% +on this it's a I always you know I I I + + + align:start position:0% +on this it's a I always you know I I I +don't like to not say anything about + + align:start position:0% +don't like to not say anything about + + + align:start position:0% +don't like to not say anything about +such an important problem as as putting + + align:start position:0% +such an important problem as as putting + + + align:start position:0% +such an important problem as as putting +points through curves through points but + + align:start position:0% +points through curves through points but + + + align:start position:0% +points through curves through points but +I don't want to make + + align:start position:0% +I don't want to make + + + align:start position:0% +I don't want to make +a make it a course on on + + align:start position:0% +a make it a course on on + + + align:start position:0% +a make it a course on on +splines + + align:start position:0% +splines + + + align:start position:0% +splines +yes yeah + + align:start position:0% +yes yeah + + + align:start position:0% +yes yeah +good okay I don't know that I'll do oh + + align:start position:0% +good okay I don't know that I'll do oh + + + align:start position:0% +good okay I don't know that I'll do oh +okay yes all right yeah two or three + + align:start position:0% +okay yes all right yeah two or three + + + align:start position:0% +okay yes all right yeah two or three +comments and that that that suggests a + + align:start position:0% +comments and that that that suggests a + + + align:start position:0% +comments and that that that suggests a +good question very good + + align:start position:0% +good question very good + + + align:start position:0% +good question very good +question can I make a a a separate + + align:start position:0% +question can I make a a a separate + + + align:start position:0% +question can I make a a a separate +comment that if I go into two + + align:start position:0% +comment that if I go into two + + + align:start position:0% +comment that if I go into two +Dimensions this is gets much tougher + + align:start position:0% +Dimensions this is gets much tougher + + + align:start position:0% +Dimensions this is gets much tougher +what happens if I had a function of X + + align:start position:0% +what happens if I had a function of X + + + align:start position:0% +what happens if I had a function of X +and Y so that I'm I've got points on a + + align:start position:0% +and Y so that I'm I've got points on a + + + align:start position:0% +and Y so that I'm I've got points on a +surface and I'm trying to fit a surface + + align:start position:0% +surface and I'm trying to fit a surface + + + align:start position:0% +surface and I'm trying to fit a surface +to it just just + + align:start position:0% +to it just just + + + align:start position:0% +to it just just +one message first that's not as easy + + align:start position:0% +one message first that's not as easy + + + align:start position:0% +one message first that's not as easy +it's pretty easy if though those points + + align:start position:0% +it's pretty easy if though those points + + + align:start position:0% +it's pretty easy if though those points +are on a rectangular grid so this is + + align:start position:0% +are on a rectangular grid so this is + + + align:start position:0% +are on a rectangular grid so this is +like typical if if I'm and then I'll + + align:start position:0% +like typical if if I'm and then I'll + + + align:start position:0% +like typical if if I'm and then I'll +come to your Nyquist question which is a + + align:start position:0% +come to your Nyquist question which is a + + + align:start position:0% +come to your Nyquist question which is a +very good one can I can I + + align:start position:0% +very good one can I can I + + + align:start position:0% +very good one can I can I +just because we're coming into 2D now + + align:start position:0% +just because we're coming into 2D now + + + align:start position:0% +just because we're coming into 2D now +suppose I there's two Dimensions I have + + align:start position:0% +suppose I there's two Dimensions I have + + + align:start position:0% +suppose I there's two Dimensions I have +a grid let's suppose it's a nice grid + + align:start position:0% +a grid let's suppose it's a nice grid + + + align:start position:0% +a grid let's suppose it's a nice grid +and at every point at every grid + + align:start position:0% +and at every point at every grid + + + align:start position:0% +and at every point at every grid +point I have a height then I'm fitting a + + align:start position:0% +point I have a height then I'm fitting a + + + align:start position:0% +point I have a height then I'm fitting a +surface right through I'm I'm my + + align:start position:0% +surface right through I'm I'm my + + + align:start position:0% +surface right through I'm I'm my +function is now a function of X and + + align:start position:0% +function is now a function of X and + + + align:start position:0% +function is now a function of X and +Y X is here Y is here f is the surface + + align:start position:0% +Y X is here Y is here f is the surface + + + align:start position:0% +Y X is here Y is here f is the surface +coming out of the board in the in the + + align:start position:0% +coming out of the board in the in the + + + align:start position:0% +coming out of the board in the in the +third dimension and fitting those points + + align:start position:0% +third dimension and fitting those points + + + align:start position:0% +third dimension and fitting those points +if they're regularly spaced like that my + + align:start position:0% +if they're regularly spaced like that my + + + align:start position:0% +if they're regularly spaced like that my +life would be okay I could use sort of + + align:start position:0% +life would be okay I could use sort of + + + align:start position:0% +life would be okay I could use sort of +products of splines in 1D X I could use + + align:start position:0% +products of splines in 1D X I could use + + + align:start position:0% +products of splines in 1D X I could use +products of + + align:start position:0% +products of + + + align:start position:0% +products of +of basis of of of uh function of splines + + align:start position:0% +of basis of of of uh function of splines + + + align:start position:0% +of basis of of of uh function of splines +in the X Direction times splines in the + + align:start position:0% +in the X Direction times splines in the + + + align:start position:0% +in the X Direction times splines in the +y direction and it would be pretty + + align:start position:0% +y direction and it would be pretty + + + align:start position:0% +y direction and it would be pretty +successful it's a it would be yeah not + + align:start position:0% +successful it's a it would be yeah not + + + align:start position:0% +successful it's a it would be yeah not +as not quite as nice but almost okay but + + align:start position:0% +as not quite as nice but almost okay but + + + align:start position:0% +as not quite as nice but almost okay but +if I have irregularly spaced points from + + align:start position:0% +if I have irregularly spaced points from + + + align:start position:0% +if I have irregularly spaced points from +a from a general + + align:start position:0% +a from a general + + + align:start position:0% +a from a general +grid uh + + align:start position:0% +grid uh + + + align:start position:0% +grid uh +it's not as easy yeah and I won't so + + align:start position:0% +it's not as easy yeah and I won't so + + + align:start position:0% +it's not as easy yeah and I won't so +people have obviously had to figure out + + align:start position:0% +people have obviously had to figure out + + + align:start position:0% +people have obviously had to figure out +how to do it and that to repeat again + + align:start position:0% +how to do it and that to repeat again + + + align:start position:0% +how to do it and that to repeat again +that's what the cad cam world is having + + align:start position:0% +that's what the cad cam world is having + + + align:start position:0% +that's what the cad cam world is having +to do all the time is fit a curve fit a + + align:start position:0% +to do all the time is fit a curve fit a + + + align:start position:0% +to do all the time is fit a curve fit a +surface through points it's it's + + align:start position:0% +surface through points it's it's + + + align:start position:0% +surface through points it's it's +significant now uh you asked about + + align:start position:0% +significant now uh you asked about + + + align:start position:0% +significant now uh you asked about +Nyquist that's so that's a good question + + align:start position:0% +Nyquist that's so that's a good question + + + align:start position:0% +Nyquist that's so that's a good question +can I just + + align:start position:0% +can I just + + + align:start position:0% +can I just +say um something about I have to say + + align:start position:0% +say um something about I have to say + + + align:start position:0% +say um something about I have to say +what but uh so what's a function called + + align:start position:0% +what but uh so what's a function called + + + align:start position:0% +what but uh so what's a function called +band + + align:start position:0% +band + + + align:start position:0% +band +limited how many have heard Nyquist + + align:start position:0% +limited how many have heard Nyquist + + + align:start position:0% +limited how many have heard Nyquist +name okay and some of you may know a lot + + align:start position:0% +name okay and some of you may know a lot + + + align:start position:0% +name okay and some of you may know a lot +more than I about it but let me + + align:start position:0% +more than I about it but let me + + + align:start position:0% +more than I about it but let me +just get some context for band limited + + align:start position:0% +just get some context for band limited + + + align:start position:0% +just get some context for band limited +function + + align:start position:0% +function + + + align:start position:0% +function +okay this is actually a topic that will + + align:start position:0% +okay this is actually a topic that will + + + align:start position:0% +okay this is actually a topic that will +belong in the third part of our course + + align:start position:0% +belong in the third part of our course + + + align:start position:0% +belong in the third part of our course +in the 48 part so this this is in this + + align:start position:0% +in the 48 part so this this is in this + + + align:start position:0% +in the 48 part so this this is in this +is a forier + + align:start position:0% + + + + align:start position:0% + +idea so we'll I'll come back to it + + align:start position:0% +idea so we'll I'll come back to it + + + align:start position:0% +idea so we'll I'll come back to it +actually and so right here I'm just + + align:start position:0% +actually and so right here I'm just + + + align:start position:0% +actually and so right here I'm just +going to say very briefly what uh what + + align:start position:0% +going to say very briefly what uh what + + + align:start position:0% +going to say very briefly what uh what +um uh how it might connect us to uh what + + align:start position:0% +um uh how it might connect us to uh what + + + align:start position:0% +um uh how it might connect us to uh what +I've said today but then let's make a a + + align:start position:0% +I've said today but then let's make a a + + + align:start position:0% +I've said today but then let's make a a +plan to when we're when we + + align:start position:0% +plan to when we're when we + + + align:start position:0% +plan to when we're when we +got the idea of 48 + + align:start position:0% +got the idea of 48 + + + align:start position:0% +got the idea of 48 +coefficients what what is a band limited + + align:start position:0% +coefficients what what is a band limited + + + align:start position:0% +coefficients what what is a band limited +function it's for it's so a f you know + + align:start position:0% +function it's for it's so a f you know + + + align:start position:0% +function it's for it's so a f you know +the F fora idea is to take F ofx and + + align:start position:0% +the F fora idea is to take F ofx and + + + align:start position:0% +the F fora idea is to take F ofx and +write it as some combination of pure + + align:start position:0% +write it as some combination of pure + + + align:start position:0% +write it as some combination of pure +frequencies e to the I KX let me say e + + align:start position:0% +frequencies e to the I KX let me say e + + + align:start position:0% +frequencies e to the I KX let me say e +to the I + + align:start position:0% +to the I + + + align:start position:0% +to the I +KX so this is Fier that's + + align:start position:0% +KX so this is Fier that's + + + align:start position:0% +KX so this is Fier that's +coming I take the function f ofx and I + + align:start position:0% +coming I take the function f ofx and I + + + align:start position:0% +coming I take the function f ofx and I +write it I could think of it as a + + align:start position:0% +write it I could think of it as a + + + align:start position:0% +write it I could think of it as a +combination + + align:start position:0% +combination + + + align:start position:0% +combination +of pure exponentials pure frequencies + + align:start position:0% +of pure exponentials pure frequencies + + + align:start position:0% +of pure exponentials pure frequencies +that would be a Fier + + align:start position:0% +that would be a Fier + + + align:start position:0% +that would be a Fier +Series so that's a for series because + + align:start position:0% +Series so that's a for series because + + + align:start position:0% +Series so that's a for series because +it's I'm using K has integer values the + + align:start position:0% +it's I'm using K has integer values the + + + align:start position:0% +it's I'm using K has integer values the +frequencies are 0 1 two three + + align:start position:0% +frequencies are 0 1 two three + + + align:start position:0% +frequencies are 0 1 two three +whatever now + + align:start position:0% +whatever now + + + align:start position:0% +whatever now +and and that that will'll use so that + + align:start position:0% +and and that that will'll use so that + + + align:start position:0% +and and that that will'll use so that +Fier series comes for functions that are + + align:start position:0% +Fier series comes for functions that are + + + align:start position:0% +Fier series comes for functions that are +periodic they repeat every 2 pi because + + align:start position:0% +periodic they repeat every 2 pi because + + + align:start position:0% +periodic they repeat every 2 pi because +those functions if I increase X by 2 pi + + align:start position:0% +those functions if I increase X by 2 pi + + + align:start position:0% +those functions if I increase X by 2 pi +don't change so I'm repeating every 2 pi + + align:start position:0% +don't change so I'm repeating every 2 pi + + + align:start position:0% +don't change so I'm repeating every 2 pi +now I I have to I have to say a word + + align:start position:0% +now I I have to I have to say a word + + + align:start position:0% +now I I have to I have to say a word +about the other possibility which would + + align:start position:0% +about the other possibility which would + + + align:start position:0% +about the other possibility which would +be to have all frequencies have I'll + + align:start position:0% +be to have all frequencies have I'll + + + align:start position:0% +be to have all frequencies have I'll +I'll integrate now K instead of summing + + align:start position:0% +I'll integrate now K instead of summing + + + align:start position:0% +I'll integrate now K instead of summing +on K I'll integrate on + + align:start position:0% +on K I'll integrate on + + + align:start position:0% +on K I'll integrate on +K what does band limited + + align:start position:0% +K what does band limited + + + align:start position:0% +K what does band limited +mean band limited means that + + align:start position:0% +mean band limited means that + + + align:start position:0% +mean band limited means that +only + + align:start position:0% +only + + + align:start position:0% +only +frequencies in a certain range say a + + align:start position:0% +frequencies in a certain range say a + + + align:start position:0% +frequencies in a certain range say a +range around zero are included so a band + + align:start position:0% +range around zero are included so a band + + + align:start position:0% +range around zero are included so a band +limited function would be a function + + align:start position:0% +limited function would be a function + + + align:start position:0% +limited function would be a function +whose frequencies go from some value say + + align:start position:0% +whose frequencies go from some value say + + + align:start position:0% +whose frequencies go from some value say +minus Omega to Omega instead of going + + align:start position:0% +minus Omega to Omega instead of going + + + align:start position:0% +minus Omega to Omega instead of going +from minus infinity to Infinity this + + align:start position:0% +from minus infinity to Infinity this + + + align:start position:0% +from minus infinity to Infinity this +would be band limited uh + + align:start position:0% + + + + align:start position:0% + +frequencies between minus + + align:start position:0% +frequencies between minus + + + align:start position:0% +frequencies between minus +Omega and + + align:start position:0% + + + + align:start position:0% + +Omega so + + align:start position:0% +Omega so + + + align:start position:0% +Omega so +that that that's another kind of smooth + + align:start position:0% +that that that's another kind of smooth + + + align:start position:0% +that that that's another kind of smooth +function that's another way + + align:start position:0% +function that's another way + + + align:start position:0% +function that's another way +to functions that have only low low + + align:start position:0% +to functions that have only low low + + + align:start position:0% +to functions that have only low low +frequencies are associated with + + align:start position:0% +frequencies are associated with + + + align:start position:0% +frequencies are associated with +smoothness + + align:start position:0% +smoothness + + + align:start position:0% +smoothness +high frequencies are associated with + + align:start position:0% +high frequencies are associated with + + + align:start position:0% +high frequencies are associated with +fast + + align:start position:0% +fast + + + align:start position:0% +fast +oscillations so the class of band + + align:start position:0% +oscillations so the class of band + + + align:start position:0% +oscillations so the class of band +limited functions gives me another a + + align:start position:0% +limited functions gives me another a + + + align:start position:0% +limited functions gives me another a +forier way to talk about smoothness so + + align:start position:0% +forier way to talk about smoothness so + + + align:start position:0% +forier way to talk about smoothness so +for us smoothness was something about + + align:start position:0% +for us smoothness was something about + + + align:start position:0% +for us smoothness was something about +how many derivatives were + + align:start position:0% +how many derivatives were + + + align:start position:0% +how many derivatives were +continuous that's the sort of smoothness + + align:start position:0% +continuous that's the sort of smoothness + + + align:start position:0% +continuous that's the sort of smoothness +in the X domain how many + + align:start position:0% +in the X domain how many + + + align:start position:0% +in the X domain how many +derivatives smoothness in the frequency + + align:start position:0% +derivatives smoothness in the frequency + + + align:start position:0% +derivatives smoothness in the frequency +domain is how fast of the frequencies + + align:start position:0% +domain is how fast of the frequencies + + + align:start position:0% +domain is how fast of the frequencies +drop off and here band limited means + + align:start position:0% +drop off and here band limited means + + + align:start position:0% +drop off and here band limited means +they drop like a shot band limited means + + align:start position:0% +they drop like a shot band limited means + + + align:start position:0% +they drop like a shot band limited means +that the frequencies in the + + align:start position:0% +that the frequencies in the + + + align:start position:0% +that the frequencies in the +function that that these e to the I kxs + + align:start position:0% +function that that these e to the I kxs + + + align:start position:0% +function that that these e to the I kxs +are not there for high frequencies high + + align:start position:0% +are not there for high frequencies high + + + align:start position:0% +are not there for high frequencies high +frequencies are are out for a band + + align:start position:0% +frequencies are are out for a band + + + align:start position:0% +frequencies are are out for a band +limited function and then you have uh + + align:start position:0% +limited function and then you have uh + + + align:start position:0% +limited function and then you have uh +then + + align:start position:0% +then + + + align:start position:0% +then +Shannon uh has a formula for the natural + + align:start position:0% +Shannon uh has a formula for the natural + + + align:start position:0% +Shannon uh has a formula for the natural +way to fit + + align:start position:0% +way to fit + + + align:start position:0% +way to fit +uh Val so our same interpolation + + align:start position:0% +uh Val so our same interpolation + + + align:start position:0% +uh Val so our same interpolation +problem so now I'm completing the answer + + align:start position:0% +problem so now I'm completing the answer + + + align:start position:0% +problem so now I'm completing the answer +to your question so I have these + + align:start position:0% +to your question so I have these + + + align:start position:0% +to your question so I have these +points so Shannon could fit a function + + align:start position:0% +points so Shannon could fit a function + + + align:start position:0% +points so Shannon could fit a function +as and it would look smooth through + + align:start position:0% +as and it would look smooth through + + + align:start position:0% +as and it would look smooth through +those + + align:start position:0% +those + + + align:start position:0% +those +points and His function would be band + + align:start position:0% +points and His function would be band + + + align:start position:0% +points and His function would be band +limited so it would be smooth again it + + align:start position:0% +limited so it would be smooth again it + + + align:start position:0% +limited so it would be smooth again it +would be uh yeah it would be smooth in + + align:start position:0% +would be uh yeah it would be smooth in + + + align:start position:0% +would be uh yeah it would be smooth in +some way yeah actually in some way this + + align:start position:0% +some way yeah actually in some way this + + + align:start position:0% +some way yeah actually in some way this +Shannon ban limited stuff is the limit + + align:start position:0% +Shannon ban limited stuff is the limit + + + align:start position:0% +Shannon ban limited stuff is the limit +of splines as the spline degree goes way + + align:start position:0% +of splines as the spline degree goes way + + + align:start position:0% +of splines as the spline degree goes way +up so we did hat functions degree one + + align:start position:0% +up so we did hat functions degree one + + + align:start position:0% +up so we did hat functions degree one +splines cubic splines I recommended as a + + align:start position:0% +splines cubic splines I recommended as a + + + align:start position:0% +splines cubic splines I recommended as a +as a as a pretty reliable construction + + align:start position:0% +as a as a pretty reliable construction + + + align:start position:0% +as a as a pretty reliable construction +but you could do fifth degre splines 7th + + align:start position:0% +but you could do fifth degre splines 7th + + + align:start position:0% +but you could do fifth degre splines 7th +degree Lins all you could keep going and + + align:start position:0% +degree Lins all you could keep going and + + + align:start position:0% +degree Lins all you could keep going and +in the limit you would get this so maybe + + align:start position:0% +in the limit you would get this so maybe + + + align:start position:0% +in the limit you would get this so maybe +that's some half part of partial answer + + align:start position:0% +that's some half part of partial answer + + + align:start position:0% +that's some half part of partial answer +to the connection between splines and + + align:start position:0% +to the connection between splines and + + + align:start position:0% +to the connection between splines and +and uh this Fier world yeah okay thanks + + align:start position:0% +and uh this Fier world yeah okay thanks + + + align:start position:0% +and uh this Fier world yeah okay thanks +yeah so the these are topics now wow + + align:start position:0% +yeah so the these are topics now wow + + + align:start position:0% +yeah so the these are topics now wow +today's lecture is kind of + + align:start position:0% +today's lecture is kind of + + + align:start position:0% +today's lecture is kind of +a can I do one really important thing + + align:start position:0% +a can I do one really important thing + + + align:start position:0% +a can I do one really important thing +now in today's lecture for you to + + align:start position:0% +now in today's lecture for you to + + + align:start position:0% +now in today's lecture for you to +remember gradient and Divergence I I + + align:start position:0% +remember gradient and Divergence I I + + + align:start position:0% +remember gradient and Divergence I I +don't want you to spend the weekend + + align:start position:0% +don't want you to spend the weekend + + + align:start position:0% +don't want you to spend the weekend +without uh thinking about gradient and + + align:start position:0% +without uh thinking about gradient and + + + align:start position:0% +without uh thinking about gradient and +Divergence + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +okay here's here's the + + align:start position:0% +okay here's here's the + + + align:start position:0% +okay here's here's the +idea that for lots and lots of + + align:start position:0% +idea that for lots and lots of + + + align:start position:0% +idea that for lots and lots of +applications for function for for region + + align:start position:0% +applications for function for for region + + + align:start position:0% +applications for function for for region +let's say in the + + align:start position:0% +let's say in the + + + align:start position:0% +let's say in the +plane I have the same uh maybe I I have + + align:start position:0% +plane I have the same uh maybe I I have + + + align:start position:0% +plane I have the same uh maybe I I have +uh uh + + align:start position:0% +uh uh + + + align:start position:0% +uh uh +what what physical example shall I pick + + align:start position:0% +what what physical example shall I pick + + + align:start position:0% +what what physical example shall I pick +now maybe I'll I'll let youu be the + + align:start position:0% +now maybe I'll I'll let youu be the + + + align:start position:0% +now maybe I'll I'll let youu be the +temperature so instead of being + + align:start position:0% +temperature so instead of being + + + align:start position:0% +temperature so instead of being +displacement let me make it + + align:start position:0% +displacement let me make it + + + align:start position:0% +displacement let me make it +temperature U okay then I have a + + align:start position:0% +temperature U okay then I have a + + + align:start position:0% +temperature U okay then I have a +temperature + + align:start position:0% +temperature + + + align:start position:0% +temperature +gradient a a slope but now the whole + + align:start position:0% +gradient a a slope but now the whole + + + align:start position:0% +gradient a a slope but now the whole +point is that's a function of X and Y + + align:start position:0% +point is that's a function of X and Y + + + align:start position:0% +point is that's a function of X and Y +then I have a temperature + + align:start position:0% +then I have a temperature + + + align:start position:0% +then I have a temperature +gradient and if I'm consistent with a + + align:start position:0% +gradient and if I'm consistent with a + + + align:start position:0% +gradient and if I'm consistent with a +notation that'll be e of X and + + align:start position:0% +notation that'll be e of X and + + + align:start position:0% +notation that'll be e of X and +Y and then you'll expect that there's + + align:start position:0% +Y and then you'll expect that there's + + + align:start position:0% +Y and then you'll expect that there's +some C of X and + + align:start position:0% +some C of X and + + + align:start position:0% +some C of X and +Y some operator C that makes that tells + + align:start position:0% +Y some operator C that makes that tells + + + align:start position:0% +Y some operator C that makes that tells +me how much heat flows this this will + + align:start position:0% +me how much heat flows this this will + + + align:start position:0% +me how much heat flows this this will +tell me something about the heat the + + align:start position:0% +tell me something about the heat the + + + align:start position:0% +tell me something about the heat the +thermal conductivity right I'm just + + align:start position:0% +thermal conductivity right I'm just + + + align:start position:0% +thermal conductivity right I'm just +really as + + align:start position:0% +really as + + + align:start position:0% +really as +I speak about this uh framework I'm just + + align:start position:0% +I speak about this uh framework I'm just + + + align:start position:0% +I speak about this uh framework I'm just +uttering the sort of the correct words + + align:start position:0% +uttering the sort of the correct words + + + align:start position:0% +uttering the sort of the correct words +having started with temperature this + + align:start position:0% +having started with temperature this + + + align:start position:0% +having started with temperature this +thing should be a temperature gradient + + align:start position:0% +thing should be a temperature gradient + + + align:start position:0% +thing should be a temperature gradient +then I should have some physical thermal + + align:start position:0% +then I should have some physical thermal + + + align:start position:0% +then I should have some physical thermal +conductivity different for different + + align:start position:0% +conductivity different for different + + + align:start position:0% +conductivity different for different +metals or different materials and and + + align:start position:0% +metals or different materials and and + + + align:start position:0% +metals or different materials and and +I'll have a heat + + align:start position:0% +I'll have a heat + + + align:start position:0% +I'll have a heat +flow W of X and Y and everybody knows + + align:start position:0% +flow W of X and Y and everybody knows + + + align:start position:0% +flow W of X and Y and everybody knows +that W will be C * e and then there will + + align:start position:0% +that W will be C * e and then there will + + + align:start position:0% +that W will be C * e and then there will +be some uh a transpose so of + + align:start position:0% +be some uh a transpose so of + + + align:start position:0% +be some uh a transpose so of +course there'll be some a transpose here + + align:start position:0% +course there'll be some a transpose here + + + align:start position:0% +course there'll be some a transpose here +and some a here and up here I'll have a + + align:start position:0% +and some a here and up here I'll have a + + + align:start position:0% +and some a here and up here I'll have a +balance + + align:start position:0% +balance + + + align:start position:0% +balance +equation + + align:start position:0% + + + + align:start position:0% + +okay so it it + + align:start position:0% +okay so it it + + + align:start position:0% +okay so it it +just I just want to think what's the + + align:start position:0% +just I just want to think what's the + + + align:start position:0% +just I just want to think what's the +what's the operator a that's that's the + + align:start position:0% +what's the operator a that's that's the + + + align:start position:0% +what's the operator a that's that's the +if we can focus on + + align:start position:0% +if we can focus on + + + align:start position:0% +if we can focus on +that question then that's what's going + + align:start position:0% +that question then that's what's going + + + align:start position:0% +that question then that's what's going +to occupy us for the certainly the whole + + align:start position:0% +to occupy us for the certainly the whole + + + align:start position:0% +to occupy us for the certainly the whole +of next week what's so I've actually + + align:start position:0% +of next week what's so I've actually + + + align:start position:0% +of next week what's so I've actually +used the word + + align:start position:0% + + + + align:start position:0% + +gradient we have functions of two + + align:start position:0% +gradient we have functions of two + + + align:start position:0% +gradient we have functions of two +variables we're looking for the change + + align:start position:0% +variables we're looking for the change + + + align:start position:0% +variables we're looking for the change +the rate of change the steepness of + + align:start position:0% +the rate of change the steepness of + + + align:start position:0% +the rate of change the steepness of +those functions so this a + + align:start position:0% +those functions so this a + + + align:start position:0% +those functions so this a +Au is going to give me two + + align:start position:0% +Au is going to give me two + + + align:start position:0% +Au is going to give me two +derivatives I've got fun I've got two + + align:start position:0% +derivatives I've got fun I've got two + + + align:start position:0% +derivatives I've got fun I've got two +variables there are two first + + align:start position:0% +variables there are two first + + + align:start position:0% +variables there are two first +derivatives both of them are + + align:start position:0% +derivatives both of them are + + + align:start position:0% +derivatives both of them are +important that's the that's what the A + + align:start position:0% +important that's the that's what the A + + + align:start position:0% +important that's the that's what the A +is for for the next big + + align:start position:0% +is for for the next big + + + align:start position:0% +is for for the next big +example in the course like the final + + align:start position:0% +example in the course like the final + + + align:start position:0% +example in the course like the final +major example of the course is when a + + align:start position:0% +major example of the course is when a + + + align:start position:0% +major example of the course is when a +acts on a function of two variables + + align:start position:0% +acts on a function of two variables + + + align:start position:0% +acts on a function of two variables +because I have a I'm in a region in the + + align:start position:0% +because I have a I'm in a region in the + + + align:start position:0% +because I have a I'm in a region in the +plane to find its rate of change and and + + align:start position:0% +plane to find its rate of change and and + + + align:start position:0% +plane to find its rate of change and and +this is called the gradient so this is + + align:start position:0% +this is called the gradient so this is + + + align:start position:0% +this is called the gradient so this is +the GR + + align:start position:0% +the GR + + + align:start position:0% +the GR +shorthand is the gradient of + + align:start position:0% +shorthand is the gradient of + + + align:start position:0% +shorthand is the gradient of +U uh yeah let me just so we have to + + align:start position:0% +U uh yeah let me just so we have to + + + align:start position:0% +U uh yeah let me just so we have to +understand + + align:start position:0% +understand + + + align:start position:0% +understand +that we have to understand what the + + align:start position:0% +that we have to understand what the + + + align:start position:0% +that we have to understand what the +gradient + + align:start position:0% +gradient + + + align:start position:0% +gradient +is and of course we want to know its + + align:start position:0% +is and of course we want to know its + + + align:start position:0% +is and of course we want to know its +transpose so let's can I just like think + + align:start position:0% +transpose so let's can I just like think + + + align:start position:0% +transpose so let's can I just like think +what should be the transpose of the + + align:start position:0% + + + + align:start position:0% + +gradient uh okay I'll take that picture + + align:start position:0% +gradient uh okay I'll take that picture + + + align:start position:0% +gradient uh okay I'll take that picture +out + + align:start position:0% +out + + + align:start position:0% +out +okay I'm thinking now about the + + align:start position:0% +okay I'm thinking now about the + + + align:start position:0% +okay I'm thinking now about the +transpose of the + + align:start position:0% +transpose of the + + + align:start position:0% +transpose of the +gradient + + align:start position:0% +gradient + + + align:start position:0% +gradient +okay so a itself + + align:start position:0% +okay so a itself + + + align:start position:0% +okay so a itself +is you could say is d by DX and D by Dy + + align:start position:0% +is you could say is d by DX and D by Dy + + + align:start position:0% +is you could say is d by DX and D by Dy +you notice how I'm I'm separating out a + + align:start position:0% +you notice how I'm I'm separating out a + + + align:start position:0% +you notice how I'm I'm separating out a +from Au U this is when this acts on a + + align:start position:0% +from Au U this is when this acts on a + + + align:start position:0% +from Au U this is when this acts on a +function this is the gradient operator + + align:start position:0% +function this is the gradient operator + + + align:start position:0% +function this is the gradient operator +that acts on a function U to produce DX + + align:start position:0% +that acts on a function U to produce DX + + + align:start position:0% +that acts on a function U to produce DX +and + + align:start position:0% +and + + + align:start position:0% +and +duy Okay now what's the transpose of + + align:start position:0% +duy Okay now what's the transpose of + + + align:start position:0% +duy Okay now what's the transpose of +this okay you can figure you can guess + + align:start position:0% +this okay you can figure you can guess + + + align:start position:0% +this okay you can figure you can guess +what it should be and then we'll see + + align:start position:0% +what it should be and then we'll see + + + align:start position:0% +what it should be and then we'll see +that yes that guess is correct so what + + align:start position:0% +that yes that guess is correct so what + + + align:start position:0% +that yes that guess is correct so what +what should a transpose look like if if + + align:start position:0% +what should a transpose look like if if + + + align:start position:0% +what should a transpose look like if if +if there's any + + align:start position:0% +if there's any + + + align:start position:0% +if there's any +justice a a transpose should + + align:start position:0% + + + + align:start position:0% + +be okay this is 2 by one + + align:start position:0% +be okay this is 2 by one + + + align:start position:0% +be okay this is 2 by one +the transpose you would expect to be a a + + align:start position:0% +the transpose you would expect to be a a + + + align:start position:0% +the transpose you would expect to be a a +a row a row Vector of I should have the + + align:start position:0% +a row a row Vector of I should have the + + + align:start position:0% +a row a row Vector of I should have the +transpose of that there and what is the + + align:start position:0% +transpose of that there and what is the + + + align:start position:0% +transpose of that there and what is the +transpose of that yeah just tell me what + + align:start position:0% +transpose of that yeah just tell me what + + + align:start position:0% +transpose of that yeah just tell me what +what because we have an idea of what + + align:start position:0% +what because we have an idea of what + + + align:start position:0% +what because we have an idea of what +what should be the transpose of d by + + align:start position:0% +what should be the transpose of d by + + + align:start position:0% +what should be the transpose of d by +DX negative d by + + align:start position:0% + + + + align:start position:0% + +DX and what should be the transpose of d + + align:start position:0% +DX and what should be the transpose of d + + + align:start position:0% +DX and what should be the transpose of d +by Dy should be negative d by Dy those + + align:start position:0% +by Dy should be negative d by Dy those + + + align:start position:0% +by Dy should be negative d by Dy those +are two different pieces this is not run + + align:start position:0% +are two different pieces this is not run + + + align:start position:0% +are two different pieces this is not run +together there's a big space in there + + align:start position:0% +together there's a big space in there + + + align:start position:0% +together there's a big space in there +right that's two pieces and what is so + + align:start position:0% +right that's two pieces and what is so + + + align:start position:0% +right that's two pieces and what is so +what is a transpose applied to a + + align:start position:0% +what is a transpose applied to a + + + align:start position:0% +what is a transpose applied to a +ah so heat flow W I want to say what is + + align:start position:0% +ah so heat flow W I want to say what is + + + align:start position:0% +ah so heat flow W I want to say what is +a transpose applied to + + align:start position:0% + + + + align:start position:0% + +W you're going to see this again + + align:start position:0% +W you're going to see this again + + + align:start position:0% +W you're going to see this again +but would just take these minutes to + + align:start position:0% +but would just take these minutes to + + + align:start position:0% +but would just take these minutes to +show it for the first time so a + + align:start position:0% +show it for the first time so a + + + align:start position:0% +show it for the first time so a +transpose wait a minute what is w a a + + align:start position:0% +transpose wait a minute what is w a a + + + align:start position:0% +transpose wait a minute what is w a a +function or is it a + + align:start position:0% +function or is it a + + + align:start position:0% +function or is it a +vector yeah we've got to get that + + align:start position:0% +vector yeah we've got to get that + + + align:start position:0% +vector yeah we've got to get that +straight before we start here's an + + align:start position:0% +straight before we start here's an + + + align:start position:0% +straight before we start here's an +ordinary function a scalar function just + + align:start position:0% +ordinary function a scalar function just + + + align:start position:0% +ordinary function a scalar function just +whatever X2 + + + align:start position:0% +whatever X2 + + + + align:start position:0% +whatever X2 + +y^2 what what is + + align:start position:0% +y^2 what what is + + + align:start position:0% +y^2 what what is +e suppose this is x^2 + y^2 what would + + align:start position:0% +e suppose this is x^2 + y^2 what would + + + align:start position:0% +e suppose this is x^2 + y^2 what would +just let's let's have a specific ific + + align:start position:0% +just let's let's have a specific ific + + + align:start position:0% +just let's let's have a specific ific +example what would e then + + align:start position:0% +example what would e then + + + align:start position:0% +example what would e then +be it's got two components right it's + + align:start position:0% +be it's got two components right it's + + + align:start position:0% +be it's got two components right it's +got an X derivative and a y derivative e + + align:start position:0% +got an X derivative and a y derivative e + + + align:start position:0% +got an X derivative and a y derivative e +is a + + align:start position:0% +is a + + + align:start position:0% +is a +vector 2X and 2 + + align:start position:0% +vector 2X and 2 + + + align:start position:0% +vector 2X and 2 +y then I multiply by C so this W has two + + align:start position:0% +y then I multiply by C so this W has two + + + align:start position:0% +y then I multiply by C so this W has two +components this has got a W1 of X and Y + + align:start position:0% +components this has got a W1 of X and Y + + + align:start position:0% +components this has got a W1 of X and Y +W2 of X and + + align:start position:0% +W2 of X and + + + align:start position:0% +W2 of X and +Y so just keep things straight so so + + align:start position:0% +Y so just keep things straight so so + + + align:start position:0% +Y so just keep things straight so so +it's that that I want to apply a + + align:start position:0% +it's that that I want to apply a + + + align:start position:0% +it's that that I want to apply a +transpose to so a transpose W is minus d + + align:start position:0% +transpose to so a transpose W is minus d + + + align:start position:0% +transpose to so a transpose W is minus d +by + + align:start position:0% +by + + + align:start position:0% +by +DX minus d by Dy and everything's coming + + align:start position:0% +DX minus d by Dy and everything's coming + + + align:start position:0% +DX minus d by Dy and everything's coming +out right because it's applied to a + + align:start position:0% +out right because it's applied to a + + + align:start position:0% +out right because it's applied to a +function W1 and + + align:start position:0% +function W1 and + + + align:start position:0% +function W1 and +W2 W is a vector field it's not a scalar + + align:start position:0% +W2 W is a vector field it's not a scalar + + + align:start position:0% +W2 W is a vector field it's not a scalar +field it's a vector field and the result + + align:start position:0% +field it's a vector field and the result + + + align:start position:0% +field it's a vector field and the result +is just what it should be minus dw1 DX + + align:start position:0% +is just what it should be minus dw1 DX + + + align:start position:0% +is just what it should be minus dw1 DX +minus dw2 + + align:start position:0% +minus dw2 + + + align:start position:0% +minus dw2 +Dy okay good + + align:start position:0% +Dy okay good + + + align:start position:0% +Dy okay good +that's we're going to this this has got + + align:start position:0% +that's we're going to this this has got + + + align:start position:0% +that's we're going to this this has got +to come out of integration by parts + + align:start position:0% +to come out of integration by parts + + + align:start position:0% +to come out of integration by parts +right so we'll have to think what is + + align:start position:0% +right so we'll have to think what is + + + align:start position:0% +right so we'll have to think what is +integration by parts mean in two + + align:start position:0% +integration by parts mean in two + + + align:start position:0% +integration by parts mean in two +variables and it's a famous formula + + align:start position:0% +variables and it's a famous formula + + + align:start position:0% +variables and it's a famous formula +named after gaus and green the greens + + align:start position:0% +named after gaus and green the greens + + + align:start position:0% +named after gaus and green the greens +formula often but do you recognize what + + align:start position:0% +formula often but do you recognize what + + + align:start position:0% +formula often but do you recognize what +I'm looking at here this is so important + + align:start position:0% +I'm looking at here this is so important + + + align:start position:0% +I'm looking at here this is so important +it has a + + align:start position:0% +it has a + + + align:start position:0% +it has a +name and what's the name and then we're + + align:start position:0% +name and what's the name and then we're + + + align:start position:0% +name and what's the name and then we're +ready to go what's the name of if I take + + align:start position:0% +ready to go what's the name of if I take + + + align:start position:0% +ready to go what's the name of if I take +a vector field like 2x2 y let me take + + align:start position:0% +a vector field like 2x2 y let me take + + + align:start position:0% +a vector field like 2x2 y let me take +2x2 y as a specific + + align:start position:0% + + + + align:start position:0% + +example suppose W is 2x2 + + align:start position:0% +example suppose W is 2x2 + + + align:start position:0% +example suppose W is 2x2 +y it was multiplied by let me take C to + + align:start position:0% +y it was multiplied by let me take C to + + + align:start position:0% +y it was multiplied by let me take C to +be one then what is a transpose + + align:start position:0% + + + + align:start position:0% + +W specifically what what what am I + + align:start position:0% +W specifically what what what am I + + + align:start position:0% +W specifically what what what am I +getting out of + + align:start position:0% +getting out of + + + align:start position:0% +getting out of +it I'm getting what do I get from + + align:start position:0% + + + + align:start position:0% + +here that's minus the X derivative of + + align:start position:0% +here that's minus the X derivative of + + + align:start position:0% +here that's minus the X derivative of +the first guy and the X derivative of + + align:start position:0% +the first guy and the X derivative of + + + align:start position:0% +the first guy and the X derivative of +that guy is two so I'm getting a minus + + align:start position:0% +that guy is two so I'm getting a minus + + + align:start position:0% +that guy is two so I'm getting a minus +two and this is minus the Y derivative + + align:start position:0% +two and this is minus the Y derivative + + + align:start position:0% +two and this is minus the Y derivative +of the second guy so that's another + + align:start position:0% +of the second guy so that's another + + + align:start position:0% +of the second guy so that's another +minus two so I'm getting a number it + + align:start position:0% +minus two so I'm getting a number it + + + align:start position:0% +minus two so I'm getting a number it +happens to be a number here I I chose + + align:start position:0% +happens to be a number here I I chose + + + align:start position:0% +happens to be a number here I I chose +such a simple function it came out to be + + align:start position:0% +such a simple function it came out to be + + + align:start position:0% +such a simple function it came out to be +a number uh and what's the name that so + + align:start position:0% +a number uh and what's the name that so + + + align:start position:0% +a number uh and what's the name that so +this is minus the what of w just just + + align:start position:0% +this is minus the what of w just just + + + align:start position:0% +this is minus the what of w just just +tell me what what's the the the name + + align:start position:0% +tell me what what's the the the name + + + align:start position:0% +tell me what what's the the the name +everybody uses for that + + align:start position:0% +everybody uses for that + + + align:start position:0% +everybody uses for that +operation the Divergence it's the minus + + align:start position:0% +operation the Divergence it's the minus + + + align:start position:0% +operation the Divergence it's the minus +the Divergence of w + + align:start position:0% + + + + align:start position:0% + +so what I'm saying here is + + align:start position:0% +so what I'm saying here is + + + align:start position:0% +so what I'm saying here is +that + + align:start position:0% +that + + + align:start position:0% +that +this + + align:start position:0% +this + + + align:start position:0% +this +I I'm saying it because uh somehow I + + align:start position:0% +I I'm saying it because uh somehow I + + + align:start position:0% +I I'm saying it because uh somehow I +remember learn studying Vector calculus + + align:start position:0% +remember learn studying Vector calculus + + + align:start position:0% +remember learn studying Vector calculus +and in that process I learned about the + + align:start position:0% +and in that process I learned about the + + + align:start position:0% +and in that process I learned about the +gradient and I learned about the + + align:start position:0% +gradient and I learned about the + + + align:start position:0% +gradient and I learned about the +Divergent but I never learned that the + + align:start position:0% +Divergent but I never learned that the + + + align:start position:0% +Divergent but I never learned that the +one was the transpose of the other I + + align:start position:0% +one was the transpose of the other I + + + align:start position:0% +one was the transpose of the other I +mean I think + + align:start position:0% +mean I think + + + align:start position:0% +mean I think +what looking back that was criminal uh + + align:start position:0% +what looking back that was criminal uh + + + align:start position:0% +what looking back that was criminal uh +to to to to teach to to describe those + + align:start position:0% +to to to to teach to to describe those + + + align:start position:0% +to to to to teach to to describe those +with a minus sign of course to to I + + align:start position:0% +with a minus sign of course to to I + + + align:start position:0% +with a minus sign of course to to I +learned Green's formula but + + align:start position:0% +learned Green's formula but + + + align:start position:0% +learned Green's formula but +now uh sort of we'll see why it why what + + align:start position:0% +now uh sort of we'll see why it why what + + + align:start position:0% +now uh sort of we'll see why it why what +it means okay that's next week's job + + align:start position:0% +it means okay that's next week's job + + + align:start position:0% +it means okay that's next week's job +have a great weekend and see you Monday \ No newline at end of file diff --git a/T8IjB94ka2g.txt b/T8IjB94ka2g.txt new file mode 100644 index 0000000000000000000000000000000000000000..08b14809b7da8f5ecc82c5978e5e479e1dcc4f3c --- /dev/null +++ b/T8IjB94ka2g.txt @@ -0,0 +1,1403 @@ +align:start position:0% + +you know so the idea is that if English + + align:start position:0% +you know so the idea is that if English + + + align:start position:0% +you know so the idea is that if English +is more of a Creole in Haitian Creole + + align:start position:0% +is more of a Creole in Haitian Creole + + + align:start position:0% +is more of a Creole in Haitian Creole +then why reserve the term Creole to only + + align:start position:0% +then why reserve the term Creole to only + + + align:start position:0% +then why reserve the term Creole to only +Creole languages right that's that's a + + align:start position:0% +Creole languages right that's that's a + + + align:start position:0% +Creole languages right that's that's a +passive very valid question and and and + + align:start position:0% +passive very valid question and and and + + + align:start position:0% +passive very valid question and and and +nowadays in Haiti and also in Mauritius + + align:start position:0% +nowadays in Haiti and also in Mauritius + + + align:start position:0% +nowadays in Haiti and also in Mauritius +I don't know whether you're aware of + + align:start position:0% +I don't know whether you're aware of + + + align:start position:0% +I don't know whether you're aware of +this debate in Mauritius people ask you + + align:start position:0% +this debate in Mauritius people ask you + + + align:start position:0% +this debate in Mauritius people ask you +know white why do we call you know + + align:start position:0% +know white why do we call you know + + + align:start position:0% +know white why do we call you know +Mauritian Creole Creole although you + + align:start position:0% +Mauritian Creole Creole although you + + + align:start position:0% +Mauritian Creole Creole although you +just call it Mauritian why don't you + + align:start position:0% +just call it Mauritian why don't you + + + align:start position:0% +just call it Mauritian why don't you +just call Asian Creole hey a Haitian and + + align:start position:0% +just call Asian Creole hey a Haitian and + + + align:start position:0% +just call Asian Creole hey a Haitian and +so as a linguist might take when I'm + + align:start position:0% +so as a linguist might take when I'm + + + align:start position:0% +so as a linguist might take when I'm +being asked that question is that well + + align:start position:0% +being asked that question is that well + + + align:start position:0% +being asked that question is that well +the people who speak the language + + align:start position:0% +the people who speak the language + + + align:start position:0% +the people who speak the language +most of them call it Creole so what is a + + align:start position:0% +most of them call it Creole so what is a + + + align:start position:0% +most of them call it Creole so what is a +linguist to say no you won't call it + + align:start position:0% +linguist to say no you won't call it + + + align:start position:0% +linguist to say no you won't call it +Haitian you see because we have a basic + + align:start position:0% +Haitian you see because we have a basic + + + align:start position:0% +Haitian you see because we have a basic +principle in linguistics at least in you + + align:start position:0% +principle in linguistics at least in you + + + align:start position:0% +principle in linguistics at least in you +know when you consider the center + + align:start position:0% +know when you consider the center + + + align:start position:0% +know when you consider the center +linguistics it's supposed to be + + align:start position:0% +linguistics it's supposed to be + + + align:start position:0% +linguistics it's supposed to be +descriptive not supposed to prescribe to + + align:start position:0% +descriptive not supposed to prescribe to + + + align:start position:0% +descriptive not supposed to prescribe to +tell people no this is what you say we + + align:start position:0% +tell people no this is what you say we + + + align:start position:0% +tell people no this is what you say we +supposed to be taught what we say I mean + + align:start position:0% +supposed to be taught what we say I mean + + + align:start position:0% +supposed to be taught what we say I mean +I have a Avila anecdote when it comes to + + align:start position:0% +I have a Avila anecdote when it comes to + + + align:start position:0% +I have a Avila anecdote when it comes to +the because people see that the time is + + align:start position:0% +the because people see that the time is + + + align:start position:0% +the because people see that the time is +negative that the term Creole because + + align:start position:0% +negative that the term Creole because + + + align:start position:0% +negative that the term Creole because +it's been used to refer to lesser + + align:start position:0% +it's been used to refer to lesser + + + align:start position:0% +it's been used to refer to lesser +languages it's basically bit of it and + + align:start position:0% +languages it's basically bit of it and + + + align:start position:0% +languages it's basically bit of it and +now as as someone but who has a question + + align:start position:0% +now as as someone but who has a question + + + align:start position:0% +now as as someone but who has a question +so as someone but up since we know at + + align:start position:0% +so as someone but up since we know at + + + align:start position:0% +so as someone but up since we know at +least we can claim that we have evidence + + align:start position:0% +least we can claim that we have evidence + + + align:start position:0% +least we can claim that we have evidence +that hey image in terms of its + + align:start position:0% +that hey image in terms of its + + + align:start position:0% +that hey image in terms of its +structures instead of its history might + + align:start position:0% +structures instead of its history might + + + align:start position:0% +structures instead of its history might +be more of a Creole than Haitian Creole + + align:start position:0% +be more of a Creole than Haitian Creole + + + align:start position:0% +be more of a Creole than Haitian Creole +so why you know the time curl then + + align:start position:0% +so why you know the time curl then + + + align:start position:0% +so why you know the time curl then +doesn't make sense if you think of + + align:start position:0% +doesn't make sense if you think of + + + align:start position:0% +doesn't make sense if you think of +Creole as a sexual term as but the party + + align:start position:0% +Creole as a sexual term as but the party + + + align:start position:0% +Creole as a sexual term as but the party +is that so the word Creole means + + align:start position:0% +is that so the word Creole means + + + align:start position:0% +is that so the word Creole means +different things different people right + + align:start position:0% +different things different people right + + + align:start position:0% +different things different people right +so in Haiti is someone called a language + + align:start position:0% +so in Haiti is someone called a language + + + align:start position:0% +so in Haiti is someone called a language +Creole they don't think of Bickerton we + + align:start position:0% +Creole they don't think of Bickerton we + + + align:start position:0% +Creole they don't think of Bickerton we +don't care about because I don't even + + align:start position:0% +don't care about because I don't even + + + align:start position:0% +don't care about because I don't even +know who begotten is I do not know who + + align:start position:0% +know who begotten is I do not know who + + + align:start position:0% +know who begotten is I do not know who +my poetry is you don't know who you know + + align:start position:0% +my poetry is you don't know who you know + + + align:start position:0% +my poetry is you don't know who you know +missing either or these other linguist + + align:start position:0% +missing either or these other linguist + + + align:start position:0% +missing either or these other linguist +who said all these ugly things about it + + align:start position:0% +who said all these ugly things about it + + + align:start position:0% +who said all these ugly things about it +about Creole languages I did not care is + + align:start position:0% +about Creole languages I did not care is + + + align:start position:0% +about Creole languages I did not care is +that that's why they call the languages + + align:start position:0% +that that's why they call the languages + + + align:start position:0% +that that's why they call the languages +and and they're happy with the time so + + align:start position:0% +and and they're happy with the time so + + + align:start position:0% +and and they're happy with the time so +for them the term has changed meaning + + align:start position:0% +for them the term has changed meaning + + + align:start position:0% +for them the term has changed meaning +the term means just this is my language + + align:start position:0% +the term means just this is my language + + + align:start position:0% +the term means just this is my language +the same way with words like let's take + + align:start position:0% +the same way with words like let's take + + + align:start position:0% +the same way with words like let's take +the word neg okay so this is the way + + align:start position:0% +the word neg okay so this is the way + + + align:start position:0% +the word neg okay so this is the way +that actually you know + + align:start position:0% +that actually you know + + + align:start position:0% +that actually you know +in Haiti we have this word now + + align:start position:0% +in Haiti we have this word now + + + align:start position:0% +in Haiti we have this word now +what does it come from it comes from the + + align:start position:0% +what does it come from it comes from the + + + align:start position:0% +what does it come from it comes from the +French okay Nick now the French neg you + + align:start position:0% +French okay Nick now the French neg you + + + align:start position:0% +French okay Nick now the French neg you +can speak in a puppy you know + + align:start position:0% +can speak in a puppy you know + + + align:start position:0% +can speak in a puppy you know +solicitation Creole this is French now + + align:start position:0% +solicitation Creole this is French now + + + align:start position:0% +solicitation Creole this is French now +you can tell that well this is connected + + align:start position:0% +you can tell that well this is connected + + + align:start position:0% +you can tell that well this is connected +to Negro right now in the movie that we + + align:start position:0% +to Negro right now in the movie that we + + + align:start position:0% +to Negro right now in the movie that we +talked about many times I'm not a negro + + align:start position:0% +talked about many times I'm not a negro + + + align:start position:0% +talked about many times I'm not a negro +you can see that the term negro can be + + align:start position:0% +you can see that the term negro can be + + + align:start position:0% +you can see that the term negro can be +seen as having some negative rotation + + align:start position:0% +seen as having some negative rotation + + + align:start position:0% +seen as having some negative rotation +it's not positive right but guess what + + align:start position:0% +it's not positive right but guess what + + + align:start position:0% +it's not positive right but guess what +in Haiti the term neg is positive you + + align:start position:0% +in Haiti the term neg is positive you + + + align:start position:0% +in Haiti the term neg is positive you +see like I can call you Michelle with + + align:start position:0% +see like I can call you Michelle with + + + align:start position:0% +see like I can call you Michelle with +the neck down no you may well I wouldn't + + align:start position:0% +the neck down no you may well I wouldn't + + + align:start position:0% +the neck down no you may well I wouldn't +see it well you might exactly my negro + + align:start position:0% +see it well you might exactly my negro + + + align:start position:0% +see it well you might exactly my negro +right but it doesn't mean it is + + align:start position:0% +right but it doesn't mean it is + + + align:start position:0% +right but it doesn't mean it is +something negative about calling someone + + align:start position:0% +something negative about calling someone + + + align:start position:0% +something negative about calling someone +like if you leave it if you live in + + align:start position:0% +like if you leave it if you live in + + + align:start position:0% +like if you leave it if you live in +Haiti yourself you know you're a white + + align:start position:0% +Haiti yourself you know you're a white + + + align:start position:0% +Haiti yourself you know you're a white +person after a couple of years Maxwell + + align:start position:0% +person after a couple of years Maxwell + + + align:start position:0% +person after a couple of years Maxwell +might call you neg you see you become + + align:start position:0% +might call you neg you see you become + + + align:start position:0% +might call you neg you see you become +neg + + align:start position:0% +neg + + + align:start position:0% +neg +and hear the term net just means person + + align:start position:0% +and hear the term net just means person + + + align:start position:0% +and hear the term net just means person +you know human you're human you see so + + align:start position:0% +you know human you're human you see so + + + align:start position:0% +you know human you're human you see so +in Haiti the term neg although it + + align:start position:0% +in Haiti the term neg although it + + + align:start position:0% +in Haiti the term neg although it +derives from neg which can be perceived + + align:start position:0% +derives from neg which can be perceived + + + align:start position:0% +derives from neg which can be perceived +as being negative it's become just now + + align:start position:0% +as being negative it's become just now + + + align:start position:0% +as being negative it's become just now +that refers to human being in fact we + + align:start position:0% +that refers to human being in fact we + + + align:start position:0% +that refers to human being in fact we +saw that in fact we'll go back to that + + align:start position:0% +saw that in fact we'll go back to that + + + align:start position:0% +saw that in fact we'll go back to that +the Italian himself see that you know in + + align:start position:0% +the Italian himself see that you know in + + + align:start position:0% +the Italian himself see that you know in +Haiti now at independence will all make + + align:start position:0% +Haiti now at independence will all make + + + align:start position:0% +Haiti now at independence will all make +with all Negroes even if you have white + + align:start position:0% +with all Negroes even if you have white + + + align:start position:0% +with all Negroes even if you have white +skin you know that's what 1805 right + + align:start position:0% +skin you know that's what 1805 right + + + align:start position:0% +skin you know that's what 1805 right +deciding told alterations that legally + + align:start position:0% +deciding told alterations that legally + + + align:start position:0% +deciding told alterations that legally +if we went in Haiti we independent we've + + align:start position:0% +if we went in Haiti we independent we've + + + align:start position:0% +if we went in Haiti we independent we've +established of freedom of sovereignty if + + align:start position:0% +established of freedom of sovereignty if + + + align:start position:0% +established of freedom of sovereignty if +you want is black + + align:start position:0% +you want is black + + + align:start position:0% +you want is black +whether you white whether you polish + + align:start position:0% +whether you white whether you polish + + + align:start position:0% +whether you white whether you polish +with since you live in Haiti you black + + align:start position:0% +with since you live in Haiti you black + + + align:start position:0% +with since you live in Haiti you black +and that was actually quite forward + + align:start position:0% +and that was actually quite forward + + + align:start position:0% +and that was actually quite forward +right it was postmodern he understood + + align:start position:0% +right it was postmodern he understood + + + align:start position:0% +right it was postmodern he understood +that race was not biological that + + align:start position:0% +that race was not biological that + + + align:start position:0% +that race was not biological that +marriage was a political concept you see + + align:start position:0% +marriage was a political concept you see + + + align:start position:0% +marriage was a political concept you see +so from the same perspective and could + + align:start position:0% +so from the same perspective and could + + + align:start position:0% +so from the same perspective and could +see well Creole in Haiti means language + + align:start position:0% +see well Creole in Haiti means language + + + align:start position:0% +see well Creole in Haiti means language +it's my language so you know and indeed + + align:start position:0% +it's my language so you know and indeed + + + align:start position:0% +it's my language so you know and indeed +there are groups like I'm on Facebook + + align:start position:0% +there are groups like I'm on Facebook + + + align:start position:0% +there are groups like I'm on Facebook +there's a group called Creole Oh funny + + align:start position:0% +there's a group called Creole Oh funny + + + align:start position:0% +there's a group called Creole Oh funny +you know Creole phony they claim that + + align:start position:0% +you know Creole phony they claim that + + + align:start position:0% +you know Creole phony they claim that +you know we can look at them or Creoles + + align:start position:0% +you know we can look at them or Creoles + + + align:start position:0% +you know we can look at them or Creoles +phony + + align:start position:0% +phony + + + align:start position:0% +phony +you know fooled me right + + align:start position:0% +you know fooled me right + + + align:start position:0% +you know fooled me right +so the route here is Creole and then + + align:start position:0% +so the route here is Creole and then + + + align:start position:0% +so the route here is Creole and then +they use it's like Francophonie you know + + align:start position:0% +they use it's like Francophonie you know + + + align:start position:0% +they use it's like Francophonie you know +this French linguistic cultural empires + + align:start position:0% +this French linguistic cultural empires + + + align:start position:0% +this French linguistic cultural empires +well let's do our own and and and talk + + align:start position:0% +well let's do our own and and and talk + + + align:start position:0% +well let's do our own and and and talk +about cool funny because we believe that + + align:start position:0% +about cool funny because we believe that + + + align:start position:0% +about cool funny because we believe that +we from wishes from seashell from heaven + + align:start position:0% +we from wishes from seashell from heaven + + + align:start position:0% +we from wishes from seashell from heaven +or from Martinique from Guadeloupe from + + align:start position:0% +or from Martinique from Guadeloupe from + + + align:start position:0% +or from Martinique from Guadeloupe from +Gyan we all speak that language that we + + align:start position:0% +Gyan we all speak that language that we + + + align:start position:0% +Gyan we all speak that language that we +call Creole and we share historical + + align:start position:0% +call Creole and we share historical + + + align:start position:0% +call Creole and we share historical +concerns interests in common so let's + + align:start position:0% +concerns interests in common so let's + + + align:start position:0% +concerns interests in common so let's +call this creates this clue for me that + + align:start position:0% +call this creates this clue for me that + + + align:start position:0% +call this creates this clue for me that +will make us stronger actually + + align:start position:0% +will make us stronger actually + + + align:start position:0% +will make us stronger actually +interestingly if you go to the web + + align:start position:0% +interestingly if you go to the web + + + align:start position:0% +interestingly if you go to the web +Facebook page do that because we have + + align:start position:0% +Facebook page do that because we have + + + align:start position:0% +Facebook page do that because we have +interesting recording so different like + + align:start position:0% +interesting recording so different like + + + align:start position:0% +interesting recording so different like +God people from God blue people from + + align:start position:0% +God people from God blue people from + + + align:start position:0% +God people from God blue people from +Martinique G Anne Marie she is speaking + + align:start position:0% +Martinique G Anne Marie she is speaking + + + align:start position:0% +Martinique G Anne Marie she is speaking +the Creole they even have Christian to + + align:start position:0% +the Creole they even have Christian to + + + align:start position:0% +the Creole they even have Christian to +be ha which is this famous French + + align:start position:0% +be ha which is this famous French + + + align:start position:0% +be ha which is this famous French +politician we know from beyond you know + + align:start position:0% +politician we know from beyond you know + + + align:start position:0% +politician we know from beyond you know +black woman raised from very eloquent + + align:start position:0% +black woman raised from very eloquent + + + align:start position:0% +black woman raised from very eloquent +they had the Rick Ritter have speaking a + + align:start position:0% +they had the Rick Ritter have speaking a + + + align:start position:0% +they had the Rick Ritter have speaking a +grannies Creole you know DNA you see and + + align:start position:0% +grannies Creole you know DNA you see and + + + align:start position:0% +grannies Creole you know DNA you see and +then you can understand them you know + + align:start position:0% +then you can understand them you know + + + align:start position:0% +then you can understand them you know +academic you know when I went to + + align:start position:0% +academic you know when I went to + + + align:start position:0% +academic you know when I went to +Mauritius I could speak Creole in + + align:start position:0% +Mauritius I could speak Creole in + + + align:start position:0% +Mauritius I could speak Creole in +Mauritius you see and people can + + align:start position:0% +Mauritius you see and people can + + + align:start position:0% +Mauritius you see and people can +understand me I could understand + + align:start position:0% +understand me I could understand + + + align:start position:0% +understand me I could understand +Mauritian speaking Creole so there is + + align:start position:0% +Mauritian speaking Creole so there is + + + align:start position:0% +Mauritian speaking Creole so there is +some evidence to Criollo funny you know + + align:start position:0% +some evidence to Criollo funny you know + + + align:start position:0% +some evidence to Criollo funny you know +that there is certain is the level of + + align:start position:0% +that there is certain is the level of + + + align:start position:0% +that there is certain is the level of +mutual understanding yeah definitely + + align:start position:0% +mutual understanding yeah definitely + + + align:start position:0% +mutual understanding yeah definitely +you're right you're right you know that + + align:start position:0% +you're right you're right you know that + + + align:start position:0% +you're right you're right you know that +that is thanks to the French that we + + align:start position:0% +that is thanks to the French that we + + + align:start position:0% +that is thanks to the French that we +have this solidarity right but you know + + align:start position:0% +have this solidarity right but you know + + + align:start position:0% +have this solidarity right but you know +it's it's it's you know you can either + + align:start position:0% +it's it's it's you know you can either + + + align:start position:0% +it's it's it's you know you can either +use it for your use it against you right + + align:start position:0% +use it for your use it against you right + + + align:start position:0% +use it for your use it against you right +in this case you think well we have this + + align:start position:0% +in this case you think well we have this + + + align:start position:0% +in this case you think well we have this +mutual common interest based on our + + align:start position:0% +mutual common interest based on our + + + align:start position:0% +mutual common interest based on our +similar languages and let's call it + + align:start position:0% +similar languages and let's call it + + + align:start position:0% +similar languages and let's call it +Californian s turn it into a critical + + align:start position:0% +Californian s turn it into a critical + + + align:start position:0% +Californian s turn it into a critical +critical power you know it's very + + align:start position:0% +critical power you know it's very + + + align:start position:0% +critical power you know it's very +idealistic but you know why not + + align:start position:0% + + + + align:start position:0% + +describing it to like people but what + + align:start position:0% +describing it to like people but what + + + align:start position:0% +describing it to like people but what +about within linguist like using a + + align:start position:0% +about within linguist like using a + + + align:start position:0% +about within linguist like using a +tongue Creole like to classify like + + align:start position:0% +tongue Creole like to classify like + + + align:start position:0% +tongue Creole like to classify like +languages originated stay the same + + align:start position:0% +languages originated stay the same + + + align:start position:0% +languages originated stay the same +well no because now in science you can + + align:start position:0% +well no because now in science you can + + + align:start position:0% +well no because now in science you can +redefine your terms right so this is + + align:start position:0% +redefine your terms right so this is + + + align:start position:0% +redefine your terms right so this is +different so when you're doing science + + align:start position:0% +different so when you're doing science + + + align:start position:0% +different so when you're doing science +you know it's like when you know so h2o + + align:start position:0% +you know it's like when you know so h2o + + + align:start position:0% +you know it's like when you know so h2o +water for a chemist it's not water for + + align:start position:0% +water for a chemist it's not water for + + + align:start position:0% +water for a chemist it's not water for +for a gardener right yes because I know + + align:start position:0% +for a gardener right yes because I know + + + align:start position:0% +for a gardener right yes because I know +we'll use water to to to to sprinkle + + align:start position:0% +we'll use water to to to to sprinkle + + + align:start position:0% +we'll use water to to to to sprinkle +flowers without thinking about this the + + align:start position:0% +flowers without thinking about this the + + + align:start position:0% +flowers without thinking about this the +structure of water but if you chemist + + align:start position:0% +structure of water but if you chemist + + + align:start position:0% +structure of water but if you chemist +the word water as it's a meaning for you + + align:start position:0% +the word water as it's a meaning for you + + + align:start position:0% +the word water as it's a meaning for you +and you might want to define what you + + align:start position:0% +and you might want to define what you + + + align:start position:0% +and you might want to define what you +mean by water in that case I think in + + align:start position:0% +mean by water in that case I think in + + + align:start position:0% +mean by water in that case I think in +system in linguistics I think that you + + align:start position:0% +system in linguistics I think that you + + + align:start position:0% +system in linguistics I think that you +can you can say well I'm going to use + + align:start position:0% +can you can say well I'm going to use + + + align:start position:0% +can you can say well I'm going to use +Creole with that particular sense and + + align:start position:0% +Creole with that particular sense and + + + align:start position:0% +Creole with that particular sense and +for me it's just you know I'm going to + + align:start position:0% +for me it's just you know I'm going to + + + align:start position:0% +for me it's just you know I'm going to +point to these languages you know the + + align:start position:0% +point to these languages you know the + + + align:start position:0% +point to these languages you know the +people call them Creoles who speak them + + align:start position:0% +people call them Creoles who speak them + + + align:start position:0% +people call them Creoles who speak them +and I'm going to use the name that they + + align:start position:0% +and I'm going to use the name that they + + + align:start position:0% +and I'm going to use the name that they +use but I'm not going to assume that it + + align:start position:0% +use but I'm not going to assume that it + + + align:start position:0% +use but I'm not going to assume that it +means something similar for all Creole + + align:start position:0% +means something similar for all Creole + + + align:start position:0% +means something similar for all Creole +languages \ No newline at end of file diff --git a/TNDIZI1v4as.txt b/TNDIZI1v4as.txt new file mode 100644 index 0000000000000000000000000000000000000000..0b523e09a1ef09980f93b6104c6ed1fb1417c084 --- /dev/null +++ b/TNDIZI1v4as.txt @@ -0,0 +1,715 @@ +align:start position:0% + +what we need to understand is at a very + + align:start position:0% +what we need to understand is at a very + + + align:start position:0% +what we need to understand is at a very +basic level how the cells uh are being + + align:start position:0% +basic level how the cells uh are being + + + align:start position:0% +basic level how the cells uh are being +governed by their environment and how we + + align:start position:0% +governed by their environment and how we + + + align:start position:0% +governed by their environment and how we +can in turn engineer the environment of + + align:start position:0% +can in turn engineer the environment of + + + align:start position:0% +can in turn engineer the environment of +the cells to affect an outcome that we + + align:start position:0% +the cells to affect an outcome that we + + + align:start position:0% +the cells to affect an outcome that we +want so there's got to be a very basic + + align:start position:0% +want so there's got to be a very basic + + + align:start position:0% +want so there's got to be a very basic +marriage of biology and Engineering to + + align:start position:0% +marriage of biology and Engineering to + + + align:start position:0% +marriage of biology and Engineering to +go from the molecular level up to a + + align:start position:0% +go from the molecular level up to a + + + align:start position:0% +go from the molecular level up to a +device level that would go into patients + + align:start position:0% +device level that would go into patients + + + align:start position:0% +device level that would go into patients +we work with an orthopedic surgeon at + + align:start position:0% +we work with an orthopedic surgeon at + + + align:start position:0% +we work with an orthopedic surgeon at +the Cleveland Clinic Dr George mushler + + align:start position:0% +the Cleveland Clinic Dr George mushler + + + align:start position:0% +the Cleveland Clinic Dr George mushler +and he treats a lot of patients who get + + align:start position:0% +and he treats a lot of patients who get + + + align:start position:0% +and he treats a lot of patients who get +big tumors in their bones and so they + + align:start position:0% +big tumors in their bones and so they + + + align:start position:0% +big tumors in their bones and so they +have to cut out very large segments of + + align:start position:0% +have to cut out very large segments of + + + align:start position:0% +have to cut out very large segments of +bone and right now there isn't a very + + align:start position:0% +bone and right now there isn't a very + + + align:start position:0% +bone and right now there isn't a very +good replacement for the large defects + + align:start position:0% +good replacement for the large defects + + + align:start position:0% +good replacement for the large defects +that are taken out so right now patients + + align:start position:0% +that are taken out so right now patients + + + align:start position:0% +that are taken out so right now patients +go in and have their knee joint chopped + + align:start position:0% +go in and have their knee joint chopped + + + align:start position:0% +go in and have their knee joint chopped +off and a prosthetic replac you can make + + align:start position:0% +off and a prosthetic replac you can make + + + align:start position:0% +off and a prosthetic replac you can make +a prosthetic knee in fact a metal knee + + align:start position:0% +a prosthetic knee in fact a metal knee + + + align:start position:0% +a prosthetic knee in fact a metal knee +with this mold that was made by + + align:start position:0% +with this mold that was made by + + + align:start position:0% +with this mold that was made by +three-dimensional printing about 10 + + align:start position:0% +three-dimensional printing about 10 + + + align:start position:0% +three-dimensional printing about 10 +years ago but what we want to do is + + align:start position:0% +years ago but what we want to do is + + + align:start position:0% +years ago but what we want to do is +instead of of chopping the knee off and + + align:start position:0% +instead of of chopping the knee off and + + + align:start position:0% +instead of of chopping the knee off and +replacing it we actually want to regrow + + align:start position:0% +replacing it we actually want to regrow + + + align:start position:0% +replacing it we actually want to regrow +the damaged tissue so now we're using + + align:start position:0% +the damaged tissue so now we're using + + + align:start position:0% +the damaged tissue so now we're using +three-dimensional printing to build + + align:start position:0% +three-dimensional printing to build + + + align:start position:0% +three-dimensional printing to build +build very sophisticated scaffolds that + + align:start position:0% +build very sophisticated scaffolds that + + + align:start position:0% +build very sophisticated scaffolds that +give instructions to the cells on how to + + align:start position:0% +give instructions to the cells on how to + + + align:start position:0% +give instructions to the cells on how to +regrow + + align:start position:0% + + + + align:start position:0% + +bone with the three-dimensional printing + + align:start position:0% +bone with the three-dimensional printing + + + align:start position:0% +bone with the three-dimensional printing +process we build complicated objects as + + align:start position:0% +process we build complicated objects as + + + align:start position:0% +process we build complicated objects as +a series of very thin two-dimensional + + align:start position:0% + + + + align:start position:0% + +slices we start by spreading a powder + + align:start position:0% +slices we start by spreading a powder + + + align:start position:0% +slices we start by spreading a powder +into a very thin layer about 100 microns + + align:start position:0% +into a very thin layer about 100 microns + + + align:start position:0% +into a very thin layer about 100 microns +thick this particular powder is made out + + align:start position:0% +thick this particular powder is made out + + + align:start position:0% +thick this particular powder is made out +of a biodegradable surgical polymer then + + align:start position:0% +of a biodegradable surgical polymer then + + + align:start position:0% +of a biodegradable surgical polymer then +we put a stencil over the top that + + align:start position:0% +we put a stencil over the top that + + + align:start position:0% +we put a stencil over the top that +governs where liquid can be printed onto + + align:start position:0% +governs where liquid can be printed onto + + + align:start position:0% +governs where liquid can be printed onto +this layer then a print head rasters + + align:start position:0% +this layer then a print head rasters + + + align:start position:0% +this layer then a print head rasters +across the surface and prints very very + + align:start position:0% +across the surface and prints very very + + + align:start position:0% +across the surface and prints very very +fine tiny droplets of a liquid in this + + align:start position:0% +fine tiny droplets of a liquid in this + + + align:start position:0% +fine tiny droplets of a liquid in this +case chloroform to dissolve the + + align:start position:0% +case chloroform to dissolve the + + + align:start position:0% +case chloroform to dissolve the +particles of powder and bind them + + align:start position:0% +particles of powder and bind them + + + align:start position:0% +particles of powder and bind them +together we can also add lots of other + + align:start position:0% +together we can also add lots of other + + + align:start position:0% +together we can also add lots of other +things that might be growth factors or + + align:start position:0% +things that might be growth factors or + + + align:start position:0% +things that might be growth factors or +things that would mediate the biological + + align:start position:0% +things that would mediate the biological + + + align:start position:0% +things that would mediate the biological +response during this + + align:start position:0% +response during this + + + align:start position:0% +response during this +process in this particular build we have + + align:start position:0% +process in this particular build we have + + + align:start position:0% +process in this particular build we have +77 different layers at the end what we + + align:start position:0% +77 different layers at the end what we + + + align:start position:0% +77 different layers at the end what we +have is a scaffold for bone regeneration + + align:start position:0% +have is a scaffold for bone regeneration + + + align:start position:0% +have is a scaffold for bone regeneration +and we're in the stage right now where + + align:start position:0% +and we're in the stage right now where + + + align:start position:0% +and we're in the stage right now where +we're testing these scaffolds in a dog + + align:start position:0% +we're testing these scaffolds in a dog + + + align:start position:0% +we're testing these scaffolds in a dog +model with an orthopedic surgeon who's + + align:start position:0% +model with an orthopedic surgeon who's + + + align:start position:0% +model with an orthopedic surgeon who's +developing better ways to use marrow in + + align:start position:0% +developing better ways to use marrow in + + + align:start position:0% +developing better ways to use marrow in +his human patients the scaffold has a + + align:start position:0% +his human patients the scaffold has a + + + align:start position:0% +his human patients the scaffold has a +very very precise internal architecture + + align:start position:0% +very very precise internal architecture + + + align:start position:0% +very very precise internal architecture +so we have a design that lets us put the + + align:start position:0% +so we have a design that lets us put the + + + align:start position:0% +so we have a design that lets us put the +marrow in and have it go to very + + align:start position:0% +marrow in and have it go to very + + + align:start position:0% +marrow in and have it go to very +specific places we also can use the + + align:start position:0% +specific places we also can use the + + + align:start position:0% +specific places we also can use the +design to call blood vessels in from the + + align:start position:0% +design to call blood vessels in from the + + + align:start position:0% +design to call blood vessels in from the +surrounding tissue so there was an + + align:start position:0% +surrounding tissue so there was an + + + align:start position:0% +surrounding tissue so there was an +enormous amount of engineering that went + + align:start position:0% +enormous amount of engineering that went + + + align:start position:0% +enormous amount of engineering that went +into making a three-dimensional model + + align:start position:0% +into making a three-dimensional model + + + align:start position:0% +into making a three-dimensional model +before we ever turned on the + + align:start position:0% +before we ever turned on the + + + align:start position:0% +before we ever turned on the +three-dimensional printer and we started + + align:start position:0% +three-dimensional printer and we started + + + align:start position:0% +three-dimensional printer and we started +with thinking about how the bone will + + align:start position:0% +with thinking about how the bone will + + + align:start position:0% +with thinking about how the bone will +grow into this scaffold we're at a very + + align:start position:0% +grow into this scaffold we're at a very + + + align:start position:0% +grow into this scaffold we're at a very +exciting time in the science of biology + + align:start position:0% +exciting time in the science of biology + + + align:start position:0% +exciting time in the science of biology +you read about it almost every day in + + align:start position:0% +you read about it almost every day in + + + align:start position:0% +you read about it almost every day in +the newspaper the Human Genome Project + + align:start position:0% +the newspaper the Human Genome Project + + + align:start position:0% +the newspaper the Human Genome Project +proteomics things that make the front + + align:start position:0% +proteomics things that make the front + + + align:start position:0% +proteomics things that make the front +page make the business page but what it + + align:start position:0% +page make the business page but what it + + + align:start position:0% +page make the business page but what it +takes to translate discoveries and basic + + align:start position:0% +takes to translate discoveries and basic + + + align:start position:0% +takes to translate discoveries and basic +science including biology into things + + align:start position:0% +science including biology into things + + + align:start position:0% +science including biology into things +that people use is engineering so you + + align:start position:0% +that people use is engineering so you + + + align:start position:0% +that people use is engineering so you +have to be able to go from molecular to + + align:start position:0% +have to be able to go from molecular to + + + align:start position:0% +have to be able to go from molecular to +a systems level and understand a huge + + align:start position:0% +a systems level and understand a huge + + + align:start position:0% +a systems level and understand a huge +context of Link scales and time scales + + align:start position:0% +context of Link scales and time scales + + + align:start position:0% +context of Link scales and time scales +you require engineering at the same time + + align:start position:0% +you require engineering at the same time + + + align:start position:0% +you require engineering at the same time +to move a science forward you need new + + align:start position:0% +to move a science forward you need new + + + align:start position:0% +to move a science forward you need new +engineering tools and new ways of + + align:start position:0% +engineering tools and new ways of + + + align:start position:0% +engineering tools and new ways of +engineering analysis in that field and + + align:start position:0% +engineering analysis in that field and + + + align:start position:0% +engineering analysis in that field and +we're at a very exciting time because + + align:start position:0% +we're at a very exciting time because + + + align:start position:0% +we're at a very exciting time because +engineering is starting to both create + + align:start position:0% +engineering is starting to both create + + + align:start position:0% +engineering is starting to both create +products out of biology and feedback + + align:start position:0% +products out of biology and feedback + + + align:start position:0% +products out of biology and feedback +into biology to make postgenomic biology + + align:start position:0% +into biology to make postgenomic biology + + + align:start position:0% +into biology to make postgenomic biology +a much uh more pervasive and exciting + + align:start position:0% +a much uh more pervasive and exciting + + + align:start position:0% +a much uh more pervasive and exciting +discipline so MIT is really the center + + align:start position:0% +discipline so MIT is really the center + + + align:start position:0% +discipline so MIT is really the center +of the universe where this is happening \ No newline at end of file diff --git a/TtItFQTNMA4.txt b/TtItFQTNMA4.txt new file mode 100644 index 0000000000000000000000000000000000000000..c8fc2bb16e3dc87576307b0a9f8dbb8ae90d323b --- /dev/null +++ b/TtItFQTNMA4.txt @@ -0,0 +1,9323 @@ +align:start position:0% + +so you know you've gone through and + + align:start position:0% +so you know you've gone through and + + + align:start position:0% +so you know you've gone through and +you've designed your converter and + + align:start position:0% +you've designed your converter and + + + align:start position:0% +you've designed your converter and +you've worked out the magnetics and the + + align:start position:0% +you've worked out the magnetics and the + + + align:start position:0% +you've worked out the magnetics and the +controls and the circuit topology all + + align:start position:0% +controls and the circuit topology all + + + align:start position:0% +controls and the circuit topology all +that stuff and now it's time to kind of + + align:start position:0% +that stuff and now it's time to kind of + + + align:start position:0% +that stuff and now it's time to kind of +put it on a board or put it in a package + + align:start position:0% +put it on a board or put it in a package + + + align:start position:0% +put it on a board or put it in a package +system and get the performance you want + + align:start position:0% +system and get the performance you want + + + align:start position:0% +system and get the performance you want +and what you'll find is that depending + + align:start position:0% +and what you'll find is that depending + + + align:start position:0% +and what you'll find is that depending +ending upon how you do this the details + + align:start position:0% +ending upon how you do this the details + + + align:start position:0% +ending upon how you do this the details +of how you put your circuit together you + + align:start position:0% +of how you put your circuit together you + + + align:start position:0% +of how you put your circuit together you +can get great performance or terrible + + align:start position:0% +can get great performance or terrible + + + align:start position:0% +can get great performance or terrible +performance and so what I'd like to do + + align:start position:0% +performance and so what I'd like to do + + + align:start position:0% +performance and so what I'd like to do +is spend a little bit of time today just + + align:start position:0% +is spend a little bit of time today just + + + align:start position:0% +is spend a little bit of time today just +talking about pla practical + + align:start position:0% +talking about pla practical + + + align:start position:0% +talking about pla practical +implementation issues and this is + + align:start position:0% +implementation issues and this is + + + align:start position:0% +implementation issues and this is +something that I'm what I'm hoping is + + align:start position:0% +something that I'm what I'm hoping is + + + align:start position:0% +something that I'm what I'm hoping is +you'll keep this in the back of your + + align:start position:0% +you'll keep this in the back of your + + + align:start position:0% +you'll keep this in the back of your +mind until the day you're actually + + align:start position:0% +mind until the day you're actually + + + align:start position:0% +mind until the day you're actually +building one of these things and and + + align:start position:0% +building one of these things and and + + + align:start position:0% +building one of these things and and +maybe the first one you build might + + align:start position:0% +maybe the first one you build might + + + align:start position:0% +maybe the first one you build might +cause you some unhappiness and then + + align:start position:0% +cause you some unhappiness and then + + + align:start position:0% +cause you some unhappiness and then +you'll remember the lecture and look at + + align:start position:0% +you'll remember the lecture and look at + + + align:start position:0% +you'll remember the lecture and look at +it and say what what can I do to fix + + align:start position:0% +it and say what what can I do to fix + + + align:start position:0% +it and say what what can I do to fix +that or you can kind of remember it all + + align:start position:0% +that or you can kind of remember it all + + + align:start position:0% +that or you can kind of remember it all +now and then you'll never have this + + align:start position:0% +now and then you'll never have this + + + align:start position:0% +now and then you'll never have this +problem and I and I certainly found over + + align:start position:0% +problem and I and I certainly found over + + + align:start position:0% +problem and I and I certainly found over +time that the more attention you pay to + + align:start position:0% +time that the more attention you pay to + + + align:start position:0% +time that the more attention you pay to +this kind of thing I'm going to talk + + align:start position:0% +this kind of thing I'm going to talk + + + align:start position:0% +this kind of thing I'm going to talk +about right now in your first design + + align:start position:0% +about right now in your first design + + + align:start position:0% +about right now in your first design +like when you + + align:start position:0% +like when you + + + align:start position:0% +like when you +first build the system the less trouble + + align:start position:0% +first build the system the less trouble + + + align:start position:0% +first build the system the less trouble +you'll have with it getting it across + + align:start position:0% +you'll have with it getting it across + + + align:start position:0% +you'll have with it getting it across +the Finish + + align:start position:0% +the Finish + + + align:start position:0% +the Finish +Line okay so uh let's talk about our + + align:start position:0% +Line okay so uh let's talk about our + + + align:start position:0% +Line okay so uh let's talk about our +friendly neighborhood Hood Buck + + align:start position:0% +friendly neighborhood Hood Buck + + + align:start position:0% +friendly neighborhood Hood Buck +converter okay so suppose I have a buck + + align:start position:0% + + + + align:start position:0% + +converter and I'll let me assume I'm + + align:start position:0% +converter and I'll let me assume I'm + + + align:start position:0% +converter and I'll let me assume I'm +coming from some Source impedance that + + align:start position:0% +coming from some Source impedance that + + + align:start position:0% +coming from some Source impedance that +we don't have to worry about it but I + + align:start position:0% +we don't have to worry about it but I + + + align:start position:0% +we don't have to worry about it but I +have a capacitor + + align:start position:0% +have a capacitor + + + align:start position:0% +have a capacitor +here to take the high frequency input + + align:start position:0% +here to take the high frequency input + + + align:start position:0% +here to take the high frequency input +Ripple Cur and to hold the voltage + + align:start position:0% +Ripple Cur and to hold the voltage + + + align:start position:0% +Ripple Cur and to hold the voltage +steady and I'll have a switch and I'll + + align:start position:0% +steady and I'll have a switch and I'll + + + align:start position:0% +steady and I'll have a switch and I'll +have a + + align:start position:0% +have a + + + align:start position:0% +have a +diode and my load inductor I mean my + + align:start position:0% +diode and my load inductor I mean my + + + align:start position:0% +diode and my load inductor I mean my +output inductor and my + + align:start position:0% +output inductor and my + + + align:start position:0% +output inductor and my +load okay + + align:start position:0% +load okay + + + align:start position:0% +load okay +as far as the switching of this + + align:start position:0% +as far as the switching of this + + + align:start position:0% +as far as the switching of this +circuit is concerned right when the + + align:start position:0% +circuit is concerned right when the + + + align:start position:0% +circuit is concerned right when the +diode is + + align:start position:0% + + + + align:start position:0% + +on the path through the circuits like + + align:start position:0% +on the path through the circuits like + + + align:start position:0% +on the path through the circuits like +this when I turn the diode off and the + + align:start position:0% +this when I turn the diode off and the + + + align:start position:0% +this when I turn the diode off and the +switch turns + + align:start position:0% +switch turns + + + align:start position:0% +switch turns +on + + align:start position:0% +on + + + align:start position:0% +on +essentially I'm commutating to this + + align:start position:0% +essentially I'm commutating to this + + + align:start position:0% +essentially I'm commutating to this +Branch right so I have a commutation + + align:start position:0% +Branch right so I have a commutation + + + align:start position:0% +Branch right so I have a commutation +between this branch and this branch of + + align:start position:0% +between this branch and this branch of + + + align:start position:0% +between this branch and this branch of +the circuit and I'm assuming all the + + align:start position:0% +the circuit and I'm assuming all the + + + align:start position:0% +the circuit and I'm assuming all the +high frequency currents going through + + align:start position:0% +high frequency currents going through + + + align:start position:0% +high frequency currents going through +the input capacitor okay likewise when + + align:start position:0% +the input capacitor okay likewise when + + + align:start position:0% +the input capacitor okay likewise when +the switch is on I'm carrying it this + + align:start position:0% +the switch is on I'm carrying it this + + + align:start position:0% +the switch is on I'm carrying it this +way and when I turn the switch + + align:start position:0% +way and when I turn the switch + + + align:start position:0% +way and when I turn the switch +off I essentially from an AC perspective + + align:start position:0% +off I essentially from an AC perspective + + + align:start position:0% +off I essentially from an AC perspective +I have a loop going this way so + + align:start position:0% +I have a loop going this way so + + + align:start position:0% +I have a loop going this way so +essentially what dominates The High + + align:start position:0% +essentially what dominates The High + + + align:start position:0% +essentially what dominates The High +Frequency behavior in terms of high + + align:start position:0% +Frequency behavior in terms of high + + + align:start position:0% +Frequency behavior in terms of high +currents is this switching Loop here + + align:start position:0% +currents is this switching Loop here + + + align:start position:0% +currents is this switching Loop here +right you can imagine that there's a + + align:start position:0% +right you can imagine that there's a + + + align:start position:0% +right you can imagine that there's a +large AC current running around this + + align:start position:0% +large AC current running around this + + + align:start position:0% +large AC current running around this +switching + + align:start position:0% +switching + + + align:start position:0% +switching +Loop okay this branch has almost + + align:start position:0% +Loop okay this branch has almost + + + align:start position:0% +Loop okay this branch has almost +constant current if you've done a good + + align:start position:0% +constant current if you've done a good + + + align:start position:0% +constant current if you've done a good +job of filtering this input will have an + + align:start position:0% +job of filtering this input will have an + + + align:start position:0% +job of filtering this input will have an +almost constant current but this is + + align:start position:0% +almost constant current but this is + + + align:start position:0% +almost constant current but this is +where the big AC current is so the first + + align:start position:0% +where the big AC current is so the first + + + align:start position:0% +where the big AC current is so the first +thing I think about when I'm putting + + align:start position:0% +thing I think about when I'm putting + + + align:start position:0% +thing I think about when I'm putting +together my circuit is how do I minimize + + align:start position:0% +together my circuit is how do I minimize + + + align:start position:0% +together my circuit is how do I minimize +that Loop in terms of its + + align:start position:0% +that Loop in terms of its + + + align:start position:0% +that Loop in terms of its +inductance + + align:start position:0% +inductance + + + align:start position:0% +inductance +okay and so um one of the things we're + + align:start position:0% +okay and so um one of the things we're + + + align:start position:0% +okay and so um one of the things we're +going to talk about today is + + align:start position:0% +going to talk about today is + + + align:start position:0% +going to talk about today is +minimizing Loop inductance and you got + + align:start position:0% +minimizing Loop inductance and you got + + + align:start position:0% +minimizing Loop inductance and you got +to the first thing you want to do when + + align:start position:0% +to the first thing you want to do when + + + align:start position:0% +to the first thing you want to do when +you look at any converter is which Loops + + align:start position:0% +you look at any converter is which Loops + + + align:start position:0% +you look at any converter is which Loops +do I care about right uh and this is the + + align:start position:0% +do I care about right uh and this is the + + + align:start position:0% +do I care about right uh and this is the +key Loop so the first thing I'm looking + + align:start position:0% +key Loop so the first thing I'm looking + + + align:start position:0% +key Loop so the first thing I'm looking +at when I'm laying out my power stage is + + align:start position:0% +at when I'm laying out my power stage is + + + align:start position:0% +at when I'm laying out my power stage is +you know what's my diode what's my + + align:start position:0% +you know what's my diode what's my + + + align:start position:0% +you know what's my diode what's my +capacitor I sorry what's my diode what's + + align:start position:0% +capacitor I sorry what's my diode what's + + + align:start position:0% +capacitor I sorry what's my diode what's +my switch here's the capacitor how am I + + align:start position:0% +my switch here's the capacitor how am I + + + align:start position:0% +my switch here's the capacitor how am I +going to close this Loop to minimize + + align:start position:0% +going to close this Loop to minimize + + + align:start position:0% +going to close this Loop to minimize +that and we've talked about how + + align:start position:0% +that and we've talked about how + + + align:start position:0% +that and we've talked about how +electromagnetic interference from that + + align:start position:0% +electromagnetic interference from that + + + align:start position:0% +electromagnetic interference from that +Loop can couple into other + + align:start position:0% +Loop can couple into other + + + align:start position:0% +Loop can couple into other +systems we'll talk about that in more + + align:start position:0% +systems we'll talk about that in more + + + align:start position:0% +systems we'll talk about that in more +detail um we should also uh + + align:start position:0% +detail um we should also uh + + + align:start position:0% +detail um we should also uh +recognize that where is the high + + align:start position:0% +recognize that where is the high + + + align:start position:0% +recognize that where is the high +switching node in this + + align:start position:0% +switching node in this + + + align:start position:0% +switching node in this +circuit + + align:start position:0% +circuit + + + align:start position:0% +circuit +okay this + + align:start position:0% +okay this + + + align:start position:0% +okay this +node has a big Square wave on it with + + align:start position:0% +node has a big Square wave on it with + + + align:start position:0% +node has a big Square wave on it with +respect to ground + + align:start position:0% +respect to ground + + + align:start position:0% +respect to ground +right + + align:start position:0% +right + + + align:start position:0% +right +so this node flying up and down can + + align:start position:0% +so this node flying up and down can + + + align:start position:0% +so this node flying up and down can +inject charge into other places in the + + align:start position:0% +inject charge into other places in the + + + align:start position:0% +inject charge into other places in the +circuit and cause noise so making this + + align:start position:0% +circuit and cause noise so making this + + + align:start position:0% +circuit and cause noise so making this +node this flying node bigger than I need + + align:start position:0% +node this flying node bigger than I need + + + align:start position:0% +node this flying node bigger than I need +it to be is kind of a bad thing right + + align:start position:0% +it to be is kind of a bad thing right + + + align:start position:0% +it to be is kind of a bad thing right +because that can capacitively inject + + align:start position:0% +because that can capacitively inject + + + align:start position:0% +because that can capacitively inject +noise into other places in the system + + align:start position:0% +noise into other places in the system + + + align:start position:0% +noise into other places in the system +okay so not only going to think about + + align:start position:0% +okay so not only going to think about + + + align:start position:0% +okay so not only going to think about +how to make this tight I also want to + + align:start position:0% +how to make this tight I also want to + + + align:start position:0% +how to make this tight I also want to +think about you know what's the size of + + align:start position:0% +think about you know what's the size of + + + align:start position:0% +think about you know what's the size of +this flying node uh and you know if if I + + align:start position:0% +this flying node uh and you know if if I + + + align:start position:0% +this flying node uh and you know if if I +imag imagine that I you know maybe I + + align:start position:0% +imag imagine that I you know maybe I + + + align:start position:0% +imag imagine that I you know maybe I +could place + + align:start position:0% +could place + + + align:start position:0% +could place +my you know maybe I could place my + + align:start position:0% +my you know maybe I could place my + + + align:start position:0% +my you know maybe I could place my +inductor over to the right and have a + + align:start position:0% +inductor over to the right and have a + + + align:start position:0% +inductor over to the right and have a +long lead going between the the switch + + align:start position:0% +long lead going between the the switch + + + align:start position:0% +long lead going between the the switch +and diode and the inductor or I could + + align:start position:0% +and diode and the inductor or I could + + + align:start position:0% +and diode and the inductor or I could +place you know if if this is my switch + + align:start position:0% +place you know if if this is my switch + + + align:start position:0% +place you know if if this is my switch +and and diode node or I could put the + + align:start position:0% +and and diode node or I could put the + + + align:start position:0% +and and diode node or I could put the +inductor here and then have a long lead + + align:start position:0% +inductor here and then have a long lead + + + align:start position:0% +inductor here and then have a long lead +going to the output + + align:start position:0% +going to the output + + + align:start position:0% +going to the output +capacitor right these two things seem + + align:start position:0% +capacitor right these two things seem + + + align:start position:0% +capacitor right these two things seem +the same because you know the lead's + + align:start position:0% +the same because you know the lead's + + + align:start position:0% +the same because you know the lead's +either in series with the inductor one + + align:start position:0% +either in series with the inductor one + + + align:start position:0% +either in series with the inductor one +side or another but this node is lying + + align:start position:0% +side or another but this node is lying + + + align:start position:0% +side or another but this node is lying +up and down and this node is about fixed + + align:start position:0% +up and down and this node is about fixed + + + align:start position:0% +up and down and this node is about fixed +right so in voltage so to the extent + + align:start position:0% +right so in voltage so to the extent + + + align:start position:0% +right so in voltage so to the extent +that this is forming a + + align:start position:0% +that this is forming a + + + align:start position:0% +that this is forming a +capacitor plate to other stuff and this + + align:start position:0% +capacitor plate to other stuff and this + + + align:start position:0% +capacitor plate to other stuff and this +is forming a capacitor plate to other + + align:start position:0% +is forming a capacitor plate to other + + + align:start position:0% +is forming a capacitor plate to other +stuff this is much worse than this + + align:start position:0% +stuff this is much worse than this + + + align:start position:0% +stuff this is much worse than this +one right so you got to think about both + + align:start position:0% +one right so you got to think about both + + + align:start position:0% +one right so you got to think about both +this Loop and this flying node in the + + align:start position:0% +this Loop and this flying node in the + + + align:start position:0% +this Loop and this flying node in the +buck converter in a boost converter it + + align:start position:0% +buck converter in a boost converter it + + + align:start position:0% +buck converter in a boost converter it +would be a different Loop in node or in + + align:start position:0% +would be a different Loop in node or in + + + align:start position:0% +would be a different Loop in node or in +some other converter would be different + + align:start position:0% +some other converter would be different + + + align:start position:0% +some other converter would be different +but that's the first thing you want to + + align:start position:0% +but that's the first thing you want to + + + align:start position:0% +but that's the first thing you want to +think about and it can really have have + + align:start position:0% +think about and it can really have have + + + align:start position:0% +think about and it can really have have +a big impact on performance and just to + + align:start position:0% +a big impact on performance and just to + + + align:start position:0% +a big impact on performance and just to +illustrate that um Rafa has actually set + + align:start position:0% +illustrate that um Rafa has actually set + + + align:start position:0% +illustrate that um Rafa has actually set +up a buck + + align:start position:0% +up a buck + + + align:start position:0% +up a buck +converter and I'm going to let her show + + align:start position:0% +converter and I'm going to let her show + + + align:start position:0% +converter and I'm going to let her show +you uh s sort of uh four + + align:start position:0% +you uh s sort of uh four + + + align:start position:0% +you uh s sort of uh four +cases okay why don't you tell me and + + align:start position:0% +cases okay why don't you tell me and + + + align:start position:0% +cases okay why don't you tell me and +since I have the mic which which case + + align:start position:0% +since I have the mic which which case + + + align:start position:0% +since I have the mic which which case +you going to do first uh we can start + + align:start position:0% +you going to do first uh we can start + + + align:start position:0% +you going to do first uh we can start +with the war one + + align:start position:0% +with the war one + + + align:start position:0% +with the war one +okay yeah so suppose I did a bad thing + + align:start position:0% +okay yeah so suppose I did a bad thing + + + align:start position:0% +okay yeah so suppose I did a bad thing +in two Dimensions I made this Loop + + align:start position:0% +in two Dimensions I made this Loop + + + align:start position:0% +in two Dimensions I made this Loop +terrible and I have excess area on this + + align:start position:0% +terrible and I have excess area on this + + + align:start position:0% +terrible and I have excess area on this +switching node right so so I'm just + + align:start position:0% +switching node right so so I'm just + + + align:start position:0% +switching node right so so I'm just +doing a bad job of laying out my circuit + + align:start position:0% +doing a bad job of laying out my circuit + + + align:start position:0% +doing a bad job of laying out my circuit +what would that waveform look like okay + + align:start position:0% +what would that waveform look like okay + + + align:start position:0% +what would that waveform look like okay +so we can see the first + + align:start position:0% + + + + align:start position:0% + +one and what you see is a whole pile of + + align:start position:0% +one and what you see is a whole pile of + + + align:start position:0% +one and what you see is a whole pile of +ringing in this circuit right so what + + align:start position:0% +ringing in this circuit right so what + + + align:start position:0% +ringing in this circuit right so what +she's looking at is you're you're + + align:start position:0% +she's looking at is you're you're + + + align:start position:0% +she's looking at is you're you're +looking at the vol at the switching node + + align:start position:0% +looking at the vol at the switching node + + + align:start position:0% +looking at the vol at the switching node +right that's right yeah so it's this + + align:start position:0% +right that's right yeah so it's this + + + align:start position:0% +right that's right yeah so it's this +voltage we're looking at this switching + + align:start position:0% +voltage we're looking at this switching + + + align:start position:0% +voltage we're looking at this switching +node voltage and what you see is there's + + align:start position:0% +node voltage and what you see is there's + + + align:start position:0% +node voltage and what you see is there's +all kinds of excess ringing there why + + align:start position:0% +all kinds of excess ringing there why + + + align:start position:0% +all kinds of excess ringing there why +because there's this inductance in this + + align:start position:0% +because there's this inductance in this + + + align:start position:0% +because there's this inductance in this +Loop which is ringing with things and + + align:start position:0% +Loop which is ringing with things and + + + align:start position:0% +Loop which is ringing with things and +then it's settling down and you know + + align:start position:0% +then it's settling down and you know + + + align:start position:0% +then it's settling down and you know +that's pretty bad right because that can + + align:start position:0% +that's pretty bad right because that can + + + align:start position:0% +that's pretty bad right because that can +inject noise elsewhere in the circuit it + + align:start position:0% +inject noise elsewhere in the circuit it + + + align:start position:0% +inject noise elsewhere in the circuit it +can even interfere with the circuit + + align:start position:0% +can even interfere with the circuit + + + align:start position:0% +can even interfere with the circuit +itself so you'll see a lot of people + + align:start position:0% +itself so you'll see a lot of people + + + align:start position:0% +itself so you'll see a lot of people +have problems that you know they build + + align:start position:0% +have problems that you know they build + + + align:start position:0% +have problems that you know they build +their circuit and maybe it works at + + align:start position:0% +their circuit and maybe it works at + + + align:start position:0% +their circuit and maybe it works at +super low voltage to the poers and they + + align:start position:0% +super low voltage to the poers and they + + + align:start position:0% +super low voltage to the poers and they +turn it off and everything starts + + align:start position:0% +turn it off and everything starts + + + align:start position:0% +turn it off and everything starts +misoperation and doing funny things it's + + align:start position:0% +misoperation and doing funny things it's + + + align:start position:0% +misoperation and doing funny things it's +because you're having interference with + + align:start position:0% +because you're having interference with + + + align:start position:0% +because you're having interference with +your own circuit right so not only can + + align:start position:0% +your own circuit right so not only can + + + align:start position:0% +your own circuit right so not only can +you interfere with the world you can + + align:start position:0% +you interfere with the world you can + + + align:start position:0% +you interfere with the world you can +interfere with yourself okay now that's + + align:start position:0% +interfere with yourself okay now that's + + + align:start position:0% +interfere with yourself okay now that's +the result of sort of two bad things + + align:start position:0% +the result of sort of two bad things + + + align:start position:0% +the result of sort of two bad things +which which one are we going to look at + + align:start position:0% +which which one are we going to look at + + + align:start position:0% +which which one are we going to look at +next we're going to move the capacitor + + align:start position:0% +next we're going to move the capacitor + + + align:start position:0% +next we're going to move the capacitor +closer to the + + align:start position:0% +closer to the + + + align:start position:0% +closer to the +switch we're going to have a bad + + align:start position:0% +switch we're going to have a bad + + + align:start position:0% +switch we're going to have a bad +switching Loop but small + + align:start position:0% +switching Loop but small + + + align:start position:0% +switching Loop but small +smaller right so we're gonna reduce the + + align:start position:0% +smaller right so we're gonna reduce the + + + align:start position:0% +smaller right so we're gonna reduce the +capacitance here we're going to improve + + align:start position:0% +capacitance here we're going to improve + + + align:start position:0% +capacitance here we're going to improve +one aspect of that + + align:start position:0% + + + + align:start position:0% + +okay so that's much more pleasant in + + align:start position:0% +okay so that's much more pleasant in + + + align:start position:0% +okay so that's much more pleasant in +terms of the amount of switching it's + + align:start position:0% +terms of the amount of switching it's + + + align:start position:0% +terms of the amount of switching it's +you can still you can see it's still + + align:start position:0% +you can still you can see it's still + + + align:start position:0% +you can still you can see it's still +noisy stuff still going on but not + + align:start position:0% +noisy stuff still going on but not + + + align:start position:0% +noisy stuff still going on but not +nearly as bad as when I was really + + align:start position:0% +nearly as bad as when I was really + + + align:start position:0% +nearly as bad as when I was really +sloppy about about both the loop + + align:start position:0% +sloppy about about both the loop + + + align:start position:0% +sloppy about about both the loop +inductance and the node capacitance now + + align:start position:0% +inductance and the node capacitance now + + + align:start position:0% +inductance and the node capacitance now +we'll do the case where we have um yeah + + align:start position:0% +we'll do the case where we have um yeah + + + align:start position:0% +we'll do the case where we have um yeah +the + + align:start position:0% +the + + + align:start position:0% +the +the capacitor is bad but I still have a + + align:start position:0% +the capacitor is bad but I still have a + + + align:start position:0% +the capacitor is bad but I still have a +big switching + + align:start position:0% + + + + align:start position:0% + +Loop and again yeah you got some ring + + align:start position:0% +Loop and again yeah you got some ring + + + align:start position:0% +Loop and again yeah you got some ring +you might not like that you might start + + align:start position:0% +you might not like that you might start + + + align:start position:0% +you might not like that you might start +thinking about putting snubbers in there + + align:start position:0% +thinking about putting snubbers in there + + + align:start position:0% +thinking about putting snubbers in there +but it's not as bad as that first case + + align:start position:0% +but it's not as bad as that first case + + + align:start position:0% +but it's not as bad as that first case +and then the last case is when you know + + align:start position:0% +and then the last case is when you know + + + align:start position:0% +and then the last case is when you know +perhaps better attention was paid to + + align:start position:0% +perhaps better attention was paid to + + + align:start position:0% +perhaps better attention was paid to +everything and this is you know sort of + + align:start position:0% +everything and this is you know sort of + + + align:start position:0% +everything and this is you know sort of +I don't want to say the ideal case but + + align:start position:0% +I don't want to say the ideal case but + + + align:start position:0% +I don't want to say the ideal case but +this is when attention was paid to the + + align:start position:0% +this is when attention was paid to the + + + align:start position:0% +this is when attention was paid to the +layout of the circuit so if you look at + + align:start position:0% +layout of the circuit so if you look at + + + align:start position:0% +layout of the circuit so if you look at +the two ends of that Spectrum you can + + align:start position:0% +the two ends of that Spectrum you can + + + align:start position:0% +the two ends of that Spectrum you can +see there's a pretty darn big difference + + align:start position:0% +see there's a pretty darn big difference + + + align:start position:0% +see there's a pretty darn big difference +between the actual performance of the + + align:start position:0% +between the actual performance of the + + + align:start position:0% +between the actual performance of the +converter right now this isn't a low + + align:start position:0% +converter right now this isn't a low + + + align:start position:0% +converter right now this isn't a low +voltage kind of low power thing that you + + align:start position:0% +voltage kind of low power thing that you + + + align:start position:0% +voltage kind of low power thing that you +know it's not that bad but when you're + + align:start position:0% +know it's not that bad but when you're + + + align:start position:0% +know it's not that bad but when you're +when you're operating at hundreds of + + align:start position:0% +when you're operating at hundreds of + + + align:start position:0% +when you're operating at hundreds of +volts and hundreds of amps + + align:start position:0% +volts and hundreds of amps + + + align:start position:0% +volts and hundreds of amps +these things get really really bad okay + + align:start position:0% +these things get really really bad okay + + + align:start position:0% +these things get really really bad okay +so you really want to think about layout + + align:start position:0% +so you really want to think about layout + + + align:start position:0% +so you really want to think about layout +so thanks very + + align:start position:0% +so thanks very + + + align:start position:0% +so thanks very +much so suppose I want to think + + align:start position:0% +much so suppose I want to think + + + align:start position:0% +much so suppose I want to think +about producing the inductance of my + + align:start position:0% +about producing the inductance of my + + + align:start position:0% +about producing the inductance of my +Loop + + align:start position:0% +Loop + + + align:start position:0% +Loop +okay what does that mean in practice + + align:start position:0% +okay what does that mean in practice + + + align:start position:0% +okay what does that mean in practice +well it means that I certainly want to + + align:start position:0% +well it means that I certainly want to + + + align:start position:0% +well it means that I certainly want to +uh place these three components close + + align:start position:0% +uh place these three components close + + + align:start position:0% +uh place these three components close +together okay okay such that if I think + + align:start position:0% +together okay okay such that if I think + + + align:start position:0% +together okay okay such that if I think +about the current flowing around in this + + align:start position:0% +about the current flowing around in this + + + align:start position:0% +about the current flowing around in this +Loop it forms a very tight area Okay so + + align:start position:0% +Loop it forms a very tight area Okay so + + + align:start position:0% +Loop it forms a very tight area Okay so +that's one way to think about it okay + + align:start position:0% +that's one way to think about it okay + + + align:start position:0% +that's one way to think about it okay +how if I imagine the current AC current + + align:start position:0% +how if I imagine the current AC current + + + align:start position:0% +how if I imagine the current AC current +circulating this Loop how much flux is + + align:start position:0% +circulating this Loop how much flux is + + + align:start position:0% +circulating this Loop how much flux is +it throwing out in the world and that + + align:start position:0% +it throwing out in the world and that + + + align:start position:0% +it throwing out in the world and that +relates to the + + align:start position:0% +relates to the + + + align:start position:0% +relates to the +inductance sometimes of course I have to + + align:start position:0% +inductance sometimes of course I have to + + + align:start position:0% +inductance sometimes of course I have to +put + + align:start position:0% +put + + + align:start position:0% +put +components at a distance there there's + + align:start position:0% +components at a distance there there's + + + align:start position:0% +components at a distance there there's +some inconnect between them that I have + + align:start position:0% +some inconnect between them that I have + + + align:start position:0% +some inconnect between them that I have +to live with right why don't we think + + align:start position:0% +to live with right why don't we think + + + align:start position:0% +to live with right why don't we think +about what is the + + align:start position:0% +about what is the + + + align:start position:0% +about what is the +um what is the parasitic of a pair of + + align:start position:0% +um what is the parasitic of a pair of + + + align:start position:0% +um what is the parasitic of a pair of +wires or a pair of traces + + align:start position:0% +wires or a pair of traces + + + align:start position:0% +wires or a pair of traces +interconnecting something okay so let's + + align:start position:0% +interconnecting something okay so let's + + + align:start position:0% +interconnecting something okay so let's +think about this + + align:start position:0% +think about this + + + align:start position:0% +think about this +example suppose I have two + + align:start position:0% +example suppose I have two + + + align:start position:0% +example suppose I have two +traces + + align:start position:0% +traces + + + align:start position:0% +traces +okay um here's the first + + align:start position:0% +okay um here's the first + + + align:start position:0% +okay um here's the first +trace and I'm going to carry current + + align:start position:0% +trace and I'm going to carry current + + + align:start position:0% +trace and I'm going to carry current +down + + align:start position:0% + + + + align:start position:0% + +it and then I'm going to return the + + align:start position:0% +it and then I'm going to return the + + + align:start position:0% +it and then I'm going to return the +current somewhere else so let me return + + align:start position:0% +current somewhere else so let me return + + + align:start position:0% +current somewhere else so let me return +it in a trace that's right under Neath + + align:start position:0% +it in a trace that's right under Neath + + + align:start position:0% +it in a trace that's right under Neath +it like + + align:start position:0% + + + + align:start position:0% + +this + + align:start position:0% +this + + + align:start position:0% +this +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and um you know I will close off the end + + align:start position:0% +and um you know I will close off the end + + + align:start position:0% +and um you know I will close off the end +I'm going to drive current in one return + + align:start position:0% +I'm going to drive current in one return + + + align:start position:0% +I'm going to drive current in one return +it on the other and let's say it's got a + + align:start position:0% +it on the other and let's say it's got a + + + align:start position:0% +it on the other and let's say it's got a +trace of a width + + align:start position:0% +trace of a width + + + align:start position:0% +trace of a width +w a length + + align:start position:0% + + + + align:start position:0% + +l and a spacing that I'm going to call + + align:start position:0% + + + + align:start position:0% + +Delta okay + + align:start position:0% +Delta okay + + + align:start position:0% +Delta okay +what would be the inductance of that + + align:start position:0% +what would be the inductance of that + + + align:start position:0% +what would be the inductance of that +Loop where I'm going to carry current + + align:start position:0% +Loop where I'm going to carry current + + + align:start position:0% +Loop where I'm going to carry current +down current down one side and back the + + align:start position:0% +down current down one side and back the + + + align:start position:0% +down current down one side and back the +other okay and if I look at this end + + align:start position:0% +other okay and if I look at this end + + + align:start position:0% +other okay and if I look at this end +on + + align:start position:0% +on + + + align:start position:0% +on +right maybe I'm going to put current in + + align:start position:0% +right maybe I'm going to put current in + + + align:start position:0% +right maybe I'm going to put current in +one end or maybe current will go in + + align:start position:0% + + + + align:start position:0% + +here right goes down the conductor comes + + align:start position:0% +here right goes down the conductor comes + + + align:start position:0% +here right goes down the conductor comes +back the other side coming out + + align:start position:0% +back the other side coming out + + + align:start position:0% +back the other side coming out +here okay and from from that what I'm + + align:start position:0% +here okay and from from that what I'm + + + align:start position:0% +here okay and from from that what I'm +going to get is some magnetic fields and + + align:start position:0% +going to get is some magnetic fields and + + + align:start position:0% +going to get is some magnetic fields and +they're going to be very + + align:start position:0% +they're going to be very + + + align:start position:0% +they're going to be very +concentrated in between the traces I'm + + align:start position:0% +concentrated in between the traces I'm + + + align:start position:0% +concentrated in between the traces I'm +assuming these traces are quite close + + align:start position:0% +assuming these traces are quite close + + + align:start position:0% +assuming these traces are quite close +together right and it's going to look + + align:start position:0% +together right and it's going to look + + + align:start position:0% +together right and it's going to look +something like this here's the magnetic + + align:start position:0% +something like this here's the magnetic + + + align:start position:0% +something like this here's the magnetic +fields right here's the H + + align:start position:0% +fields right here's the H + + + align:start position:0% +fields right here's the H +Fields looks like something like this if + + align:start position:0% +Fields looks like something like this if + + + align:start position:0% +Fields looks like something like this if +I'm being schematic about it does that + + align:start position:0% +I'm being schematic about it does that + + + align:start position:0% +I'm being schematic about it does that +make sense + + align:start position:0% + + + + align:start position:0% + +everybody so the question is if these + + align:start position:0% +everybody so the question is if these + + + align:start position:0% +everybody so the question is if these +are the H fields + + align:start position:0% + + + + align:start position:0% + +right how might I analyze this thing and + + align:start position:0% +right how might I analyze this thing and + + + align:start position:0% +right how might I analyze this thing and +let me do an + + align:start position:0% +let me do an + + + align:start position:0% +let me do an +analysis a very simple analysis just to + + align:start position:0% +analysis a very simple analysis just to + + + align:start position:0% +analysis a very simple analysis just to +say What are the tradeoffs in the + + align:start position:0% +say What are the tradeoffs in the + + + align:start position:0% +say What are the tradeoffs in the +interconnect so we can say okay the + + align:start position:0% +interconnect so we can say okay the + + + align:start position:0% +interconnect so we can say okay the +integral of h. + + align:start position:0% + + + + align:start position:0% + +DL is equal to the integral of aj. Da + + align:start position:0% +DL is equal to the integral of aj. Da + + + align:start position:0% +DL is equal to the integral of aj. Da +which is just the the which is just the + + align:start position:0% +which is just the the which is just the + + + align:start position:0% +which is just the the which is just the +net current right this a I'm I'm + + align:start position:0% +net current right this a I'm I'm + + + align:start position:0% +net current right this a I'm I'm +ignoring displacement current in this + + align:start position:0% +ignoring displacement current in this + + + align:start position:0% +ignoring displacement current in this +okay so what I'm saying is that if I + + align:start position:0% +okay so what I'm saying is that if I + + + align:start position:0% +okay so what I'm saying is that if I +integrate the H field around any + + align:start position:0% +integrate the H field around any + + + align:start position:0% +integrate the H field around any +Loop okay I'm going to get the net + + align:start position:0% +Loop okay I'm going to get the net + + + align:start position:0% +Loop okay I'm going to get the net +current enclosed so suppose this total + + align:start position:0% +current enclosed so suppose this total + + + align:start position:0% +current enclosed so suppose this total +current here is + + align:start position:0% +current here is + + + align:start position:0% +current here is +I all right well that's + + align:start position:0% +I all right well that's + + + align:start position:0% +I all right well that's +fine the simplest thing for me to think + + align:start position:0% +fine the simplest thing for me to think + + + align:start position:0% +fine the simplest thing for me to think +about might be the fact that the fields + + align:start position:0% +about might be the fact that the fields + + + align:start position:0% +about might be the fact that the fields +are really concentrated in between the + + align:start position:0% +are really concentrated in between the + + + align:start position:0% +are really concentrated in between the +traces and they're kind of very diffuse + + align:start position:0% +traces and they're kind of very diffuse + + + align:start position:0% +traces and they're kind of very diffuse +out here so maybe I can make the + + align:start position:0% +out here so maybe I can make the + + + align:start position:0% +out here so maybe I can make the +approximation and this is purely + + align:start position:0% +approximation and this is purely + + + align:start position:0% +approximation and this is purely +approximation that all the field that I + + align:start position:0% +approximation that all the field that I + + + align:start position:0% +approximation that all the field that I +I'm interested in is in here right so + + align:start position:0% +I'm interested in is in here right so + + + align:start position:0% +I'm interested in is in here right so +then if I took this integral around this + + align:start position:0% +then if I took this integral around this + + + align:start position:0% +then if I took this integral around this +loop I might say the integral of H.L is + + align:start position:0% +loop I might say the integral of H.L is + + + align:start position:0% +loop I might say the integral of H.L is +just H + + align:start position:0% +just H + + + align:start position:0% +just H +subx let me call this the X direction + + align:start position:0% +subx let me call this the X direction + + + align:start position:0% +subx let me call this the X direction +right it's the H inside the inside + + align:start position:0% +right it's the H inside the inside + + + align:start position:0% +right it's the H inside the inside +between here times this is the width of + + align:start position:0% +between here times this is the width of + + + align:start position:0% +between here times this is the width of +the + + align:start position:0% + + + + align:start position:0% + +winding is equal to I or equivalently I + + align:start position:0% +winding is equal to I or equivalently I + + + align:start position:0% +winding is equal to I or equivalently I +could approximate this H field as H subx + + align:start position:0% +could approximate this H field as H subx + + + align:start position:0% +could approximate this H field as H subx +is equal to I over + + align:start position:0% + + + + align:start position:0% + +all right has the right units amps per + + align:start position:0% +all right has the right units amps per + + + align:start position:0% +all right has the right units amps per +meter um how much energy am I storing in + + align:start position:0% +meter um how much energy am I storing in + + + align:start position:0% +meter um how much energy am I storing in +this thing well again I'm only going to + + align:start position:0% +this thing well again I'm only going to + + + align:start position:0% +this thing well again I'm only going to +pay attention to the really the energy + + align:start position:0% +pay attention to the really the energy + + + align:start position:0% +pay attention to the really the energy +I'm storing here but that ought to be + + align:start position:0% +I'm storing here but that ought to be + + + align:start position:0% +I'm storing here but that ought to be +most of the energy I'm going to ignore + + align:start position:0% +most of the energy I'm going to ignore + + + align:start position:0% +most of the energy I'm going to ignore +this sort of the fringing Fields out + + align:start position:0% +this sort of the fringing Fields out + + + align:start position:0% +this sort of the fringing Fields out +here even though I know they exist so + + align:start position:0% +here even though I know they exist so + + + align:start position:0% +here even though I know they exist so +that means I get the + + align:start position:0% +that means I get the + + + align:start position:0% +that means I get the +integral the magnetic energy storage is + + align:start position:0% +integral the magnetic energy storage is + + + align:start position:0% +integral the magnetic energy storage is +equal to the integral of b.h + + align:start position:0% +equal to the integral of b.h + + + align:start position:0% +equal to the integral of b.h +DV okay which is going to give me 12 + + align:start position:0% +DV okay which is going to give me 12 + + + align:start position:0% +DV okay which is going to give me 12 +mu uh H + + align:start position:0% + + + + align:start position:0% + +sared times the volume which in this + + align:start position:0% +sared times the volume which in this + + + align:start position:0% +sared times the volume which in this +case is going to be equal to 12 + + align:start position:0% +case is going to be equal to 12 + + + align:start position:0% +case is going to be equal to 12 +mu I over i^ 2 over w^2 time the volume + + align:start position:0% +mu I over i^ 2 over w^2 time the volume + + + align:start position:0% +mu I over i^ 2 over w^2 time the volume +which is W * L * Delta right so I'm + + align:start position:0% +which is W * L * Delta right so I'm + + + align:start position:0% +which is W * L * Delta right so I'm +finding all the energy stored sort of in + + align:start position:0% +finding all the energy stored sort of in + + + align:start position:0% +finding all the energy stored sort of in +between the plates of this conductor in + + align:start position:0% +between the plates of this conductor in + + + align:start position:0% +between the plates of this conductor in +return any questions about + + align:start position:0% + + + + align:start position:0% + +that so this is also equal + + align:start position:0% +that so this is also equal + + + align:start position:0% +that so this is also equal +to li^ + + align:start position:0% +to li^ + + + align:start position:0% +to li^ +2 okay that's the energy I'm storing in + + align:start position:0% +2 okay that's the energy I'm storing in + + + align:start position:0% +2 okay that's the energy I'm storing in +the magnetic field and if I work that + + align:start position:0% +the magnetic field and if I work that + + + align:start position:0% +the magnetic field and if I work that +out right this + + align:start position:0% + + + + align:start position:0% + +cancels right then I get if I just + + align:start position:0% +cancels right then I get if I just + + + align:start position:0% +cancels right then I get if I just +pattern match here what I get is + + align:start position:0% +pattern match here what I get is + + + align:start position:0% +pattern match here what I get is +L is approximately equal to the with + + align:start position:0% +L is approximately equal to the with + + + align:start position:0% +L is approximately equal to the with +these simp simplifications mu + + align:start position:0% +these simp simplifications mu + + + align:start position:0% +these simp simplifications mu +not + + align:start position:0% +not + + + align:start position:0% +not +L over W and + + align:start position:0% + + + + align:start position:0% + +Delta okay this is sort of the + + align:start position:0% +Delta okay this is sort of the + + + align:start position:0% +Delta okay this is sort of the +equivalent of saying you know + + align:start position:0% +equivalent of saying you know + + + align:start position:0% +equivalent of saying you know +capacitance is Epsilon not a over D I'm + + align:start position:0% +capacitance is Epsilon not a over D I'm + + + align:start position:0% +capacitance is Epsilon not a over D I'm +ignoring fringing between two plates + + align:start position:0% +ignoring fringing between two plates + + + align:start position:0% +ignoring fringing between two plates +this is sort of the magnetic equivalent + + align:start position:0% +this is sort of the magnetic equivalent + + + align:start position:0% +this is sort of the magnetic equivalent +of that okay so the + + align:start position:0% +of that okay so the + + + align:start position:0% +of that okay so the +inductance of this Trace to carry + + align:start position:0% +inductance of this Trace to carry + + + align:start position:0% +inductance of this Trace to carry +current up and back is going to be + + align:start position:0% +current up and back is going to be + + + align:start position:0% +current up and back is going to be +basically mu l w over W + + align:start position:0% +basically mu l w over W + + + align:start position:0% +basically mu l w over W +Delta so if I want a low inductance Loop + + align:start position:0% +Delta so if I want a low inductance Loop + + + align:start position:0% +Delta so if I want a low inductance Loop +what do I want I firstly obviously I + + align:start position:0% +what do I want I firstly obviously I + + + align:start position:0% +what do I want I firstly obviously I +mean I'm assuming there's no magnetic + + align:start position:0% +mean I'm assuming there's no magnetic + + + align:start position:0% +mean I'm assuming there's no magnetic +material in here clearly I don't want + + align:start position:0% +material in here clearly I don't want + + + align:start position:0% +material in here clearly I don't want +magnetic material in there if I want it + + align:start position:0% +magnetic material in there if I want it + + + align:start position:0% +magnetic material in there if I want it +to be low + + align:start position:0% +to be low + + + align:start position:0% +to be low +inductance uh I want it to be short put + + align:start position:0% +inductance uh I want it to be short put + + + align:start position:0% +inductance uh I want it to be short put +everything as close together in terms of + + align:start position:0% +everything as close together in terms of + + + align:start position:0% +everything as close together in terms of +the length I'm carrying the current over + + align:start position:0% +the length I'm carrying the current over + + + align:start position:0% +the length I'm carrying the current over +as + + align:start position:0% +as + + + align:start position:0% +as +possible if I have to carry a current in + + align:start position:0% +possible if I have to carry a current in + + + align:start position:0% +possible if I have to carry a current in +a trace I would like the trace to be + + align:start position:0% +a trace I would like the trace to be + + + align:start position:0% +a trace I would like the trace to be +wide The Wider the trace the more the + + align:start position:0% +wide The Wider the trace the more the + + + align:start position:0% +wide The Wider the trace the more the +current and field spreads out and the + + align:start position:0% +current and field spreads out and the + + + align:start position:0% +current and field spreads out and the +lower net energy + + align:start position:0% +lower net energy + + + align:start position:0% +lower net energy +stored okay because the width you know + + align:start position:0% +stored okay because the width you know + + + align:start position:0% +stored okay because the width you know +the width helps me reduce the field + + align:start position:0% +the width helps me reduce the field + + + align:start position:0% +the width helps me reduce the field +magnitude and even though I'm carrying + + align:start position:0% +magnitude and even though I'm carrying + + + align:start position:0% +magnitude and even though I'm carrying +it over a wider space I have more volume + + align:start position:0% +it over a wider space I have more volume + + + align:start position:0% +it over a wider space I have more volume +I get a lower inductance then the other + + align:start position:0% +I get a lower inductance then the other + + + align:start position:0% +I get a lower inductance then the other +thing I can see is here I want Delta to + + align:start position:0% +thing I can see is here I want Delta to + + + align:start position:0% +thing I can see is here I want Delta to +be small right so if I'm going to carry + + align:start position:0% +be small right so if I'm going to carry + + + align:start position:0% +be small right so if I'm going to carry +current out and return it I want the + + align:start position:0% +current out and return it I want the + + + align:start position:0% +current out and return it I want the +spacing between those traces to be + + align:start position:0% +spacing between those traces to be + + + align:start position:0% +spacing between those traces to be +really low okay so the thing I'm + + align:start position:0% +really low okay so the thing I'm + + + align:start position:0% +really low okay so the thing I'm +thinking about when I'm thinking about + + align:start position:0% +thinking about when I'm thinking about + + + align:start position:0% +thinking about when I'm thinking about +what am I going to make this + + align:start position:0% +what am I going to make this + + + align:start position:0% +what am I going to make this +interconnect Loop do it's not only that + + align:start position:0% +interconnect Loop do it's not only that + + + align:start position:0% +interconnect Loop do it's not only that +I want I can think about I can imagine + + align:start position:0% +I want I can think about I can imagine + + + align:start position:0% +I want I can think about I can imagine +this original thing I + + align:start position:0% +this original thing I + + + align:start position:0% +this original thing I +drew and say yeah I want this Loop to be + + align:start position:0% +drew and say yeah I want this Loop to be + + + align:start position:0% +drew and say yeah I want this Loop to be +tight but that can you know this might + + align:start position:0% +tight but that can you know this might + + + align:start position:0% +tight but that can you know this might +actually be in multiple Dimensions that + + align:start position:0% +actually be in multiple Dimensions that + + + align:start position:0% +actually be in multiple Dimensions that +I have to think about and if I have to + + align:start position:0% +I have to think about and if I have to + + + align:start position:0% +I have to think about and if I have to +carry current over some distance + + align:start position:0% +carry current over some distance + + + align:start position:0% +carry current over some distance +carrying a y trace and putting those + + align:start position:0% +carrying a y trace and putting those + + + align:start position:0% +carrying a y trace and putting those +traces closer together helps me make + + align:start position:0% +traces closer together helps me make + + + align:start position:0% +traces closer together helps me make +that inductance + + align:start position:0% +that inductance + + + align:start position:0% +that inductance +low okay any questions about + + align:start position:0% + + + + align:start position:0% + +that so you know if I'm you know an + + align:start position:0% +that so you know if I'm you know an + + + align:start position:0% +that so you know if I'm you know an +example of this would be not only for + + align:start position:0% +example of this would be not only for + + + align:start position:0% +example of this would be not only for +the switching Loop but you know the Gate + + align:start position:0% +the switching Loop but you know the Gate + + + align:start position:0% +the switching Loop but you know the Gate +Drive I got to put the gate drive and I + + align:start position:0% +Drive I got to put the gate drive and I + + + align:start position:0% +Drive I got to put the gate drive and I +want to send current out and bring the + + align:start position:0% +want to send current out and bring the + + + align:start position:0% +want to send current out and bring the +current back right when I'm thinking + + align:start position:0% +current back right when I'm thinking + + + align:start position:0% +current back right when I'm thinking +about that if you want the energy + + align:start position:0% +about that if you want the energy + + + align:start position:0% +about that if you want the energy +storage to be small at least the + + align:start position:0% +storage to be small at least the + + + align:start position:0% +storage to be small at least the +magnetic energy storage to be small use + + align:start position:0% +magnetic energy storage to be small use + + + align:start position:0% +magnetic energy storage to be small use +a wide Trace put the return very + + align:start position:0% +a wide Trace put the return very + + + align:start position:0% +a wide Trace put the return very +close + + align:start position:0% + + + + align:start position:0% + +okay now what would + + align:start position:0% +okay now what would + + + align:start position:0% +okay now what would +be um the equivalent of that for this + + align:start position:0% +be um the equivalent of that for this + + + align:start position:0% +be um the equivalent of that for this +Loop right what + + align:start position:0% +Loop right what + + + align:start position:0% +Loop right what +happens um the parasitic capacitance + + align:start position:0% +happens um the parasitic capacitance + + + align:start position:0% +happens um the parasitic capacitance +suppose I have some Trace + + align:start position:0% + + + + align:start position:0% + +you know this is my switching node and + + align:start position:0% +you know this is my switching node and + + + align:start position:0% +you know this is my switching node and +this is say ground or something or or + + align:start position:0% +this is say ground or something or or + + + align:start position:0% +this is say ground or something or or +some other node and I'm asking what's + + align:start position:0% +some other node and I'm asking what's + + + align:start position:0% +some other node and I'm asking what's +the capacitance between these two pieces + + align:start position:0% +the capacitance between these two pieces + + + align:start position:0% +the capacitance between these two pieces +of metal that are very close to each + + align:start position:0% +of metal that are very close to each + + + align:start position:0% +of metal that are very close to each +other that I think is + + align:start position:0% +other that I think is + + + align:start position:0% +other that I think is +um more familiar to people right people + + align:start position:0% +um more familiar to people right people + + + align:start position:0% +um more familiar to people right people +recall that the + + align:start position:0% +recall that the + + + align:start position:0% +recall that the +capacitance is equal to Epsilon it's the + + align:start position:0% +capacitance is equal to Epsilon it's the + + + align:start position:0% +capacitance is equal to Epsilon it's the +dialectric between my two pieces of + + align:start position:0% +dialectric between my two pieces of + + + align:start position:0% +dialectric between my two pieces of +metal times the a area ided the distance + + align:start position:0% +metal times the a area ided the distance + + + align:start position:0% +metal times the a area ided the distance +Epsilon a over D which in the way I've + + align:start position:0% +Epsilon a over D which in the way I've + + + align:start position:0% +Epsilon a over D which in the way I've +been writing this with these two plate + + align:start position:0% +been writing this with these two plate + + + align:start position:0% +been writing this with these two plate +sizes would be Epsilon times the area + + align:start position:0% +sizes would be Epsilon times the area + + + align:start position:0% +sizes would be Epsilon times the area +would be width time the length + + align:start position:0% +would be width time the length + + + align:start position:0% +would be width time the length +/ + + align:start position:0% +/ + + + align:start position:0% +/ +Delta does that make + + align:start position:0% +Delta does that make + + + align:start position:0% +Delta does that make +sense so what does this say um in this + + align:start position:0% +sense so what does this say um in this + + + align:start position:0% +sense so what does this say um in this +case if I want to make capacitance small + + align:start position:0% +case if I want to make capacitance small + + + align:start position:0% +case if I want to make capacitance small +I also want to make the length of this + + align:start position:0% +I also want to make the length of this + + + align:start position:0% +I also want to make the length of this +thing short + + align:start position:0% +thing short + + + align:start position:0% +thing short +okay but notice that whereas inductance + + align:start position:0% +okay but notice that whereas inductance + + + align:start position:0% +okay but notice that whereas inductance +goes + + align:start position:0% +goes + + + align:start position:0% +goes +as um let's see where do I have it here + + align:start position:0% +as um let's see where do I have it here + + + align:start position:0% +as um let's see where do I have it here +L over Del L over Delta so let me let me + + align:start position:0% +L over Del L over Delta so let me let me + + + align:start position:0% +L over Del L over Delta so let me let me +write c c is equal to + + align:start position:0% +write c c is equal to + + + align:start position:0% +write c c is equal to +Epsilon + + align:start position:0% +Epsilon + + + align:start position:0% +Epsilon +uh uh L * W over Delta + + align:start position:0% +uh uh L * W over Delta + + + align:start position:0% +uh uh L * W over Delta +right if I thought about my inductance + + align:start position:0% +right if I thought about my inductance + + + align:start position:0% +right if I thought about my inductance +per unit + + align:start position:0% +per unit + + + align:start position:0% +per unit +length is + + align:start position:0% +length is + + + align:start position:0% +length is +Mu over + + align:start position:0% +Mu over + + + align:start position:0% +Mu over +W + + align:start position:0% +W + + + align:start position:0% +W +Delta + + align:start position:0% +Delta + + + align:start position:0% +Delta +okay + + align:start position:0% +okay + + + align:start position:0% +okay +capacitance what did I do + + align:start position:0% + + + + align:start position:0% + +here it should be yes that's completely + + align:start position:0% +here it should be yes that's completely + + + align:start position:0% +here it should be yes that's completely +wrong it's what happens when I skip + + align:start position:0% +wrong it's what happens when I skip + + + align:start position:0% +wrong it's what happens when I skip +boards the inductance needs to + + align:start position:0% +boards the inductance needs to + + + align:start position:0% +boards the inductance needs to +be m not yeah all right that's what I + + align:start position:0% +be m not yeah all right that's what I + + + align:start position:0% +be m not yeah all right that's what I +did Delta over w + + align:start position:0% +did Delta over w + + + align:start position:0% +did Delta over w +right if I want the inductance to low + + align:start position:0% +right if I want the inductance to low + + + align:start position:0% +right if I want the inductance to low +make it make W big and and Delta small + + align:start position:0% +make it make W big and and Delta small + + + align:start position:0% +make it make W big and and Delta small +okay this should be uh W over + + align:start position:0% +okay this should be uh W over + + + align:start position:0% +okay this should be uh W over +Delta right it's the induct I'm sorry + + align:start position:0% +Delta right it's the induct I'm sorry + + + align:start position:0% +Delta right it's the induct I'm sorry +the + + align:start position:0% + + + + align:start position:0% + +capacitance right inductance per unit + + align:start position:0% +capacitance right inductance per unit + + + align:start position:0% +capacitance right inductance per unit +length is then Mu Delta over + + align:start position:0% + + + + align:start position:0% + +W right so L Prime because if I I have + + align:start position:0% +W right so L Prime because if I I have + + + align:start position:0% +W right so L Prime because if I I have +to do it over some length then I can say + + align:start position:0% +to do it over some length then I can say + + + align:start position:0% +to do it over some length then I can say +what this is and I want Delta to be + + align:start position:0% +what this is and I want Delta to be + + + align:start position:0% +what this is and I want Delta to be +small and W to be big if I calculated + + align:start position:0% +small and W to be big if I calculated + + + align:start position:0% +small and W to be big if I calculated +the capacitance the capacitance per unit + + align:start position:0% +the capacitance the capacitance per unit + + + align:start position:0% +the capacitance the capacitance per unit +length is Epsilon time W over + + align:start position:0% +length is Epsilon time W over + + + align:start position:0% +length is Epsilon time W over +Delta okay so if I'm thinking about some + + align:start position:0% +Delta okay so if I'm thinking about some + + + align:start position:0% +Delta okay so if I'm thinking about some +Trace in its return or two pieces of + + align:start position:0% +Trace in its return or two pieces of + + + align:start position:0% +Trace in its return or two pieces of +metal close to each other whatever I do + + align:start position:0% +metal close to each other whatever I do + + + align:start position:0% +metal close to each other whatever I do +to reduce the inductance increases the + + align:start position:0% +to reduce the inductance increases the + + + align:start position:0% +to reduce the inductance increases the +capacitance in vice + + align:start position:0% +capacitance in vice + + + align:start position:0% +capacitance in vice +versa Okay so so you know in some in + + align:start position:0% +versa Okay so so you know in some in + + + align:start position:0% +versa Okay so so you know in some in +some cases if I do the best thing I can + + align:start position:0% +some cases if I do the best thing I can + + + align:start position:0% +some cases if I do the best thing I can +do I'm going to be trading capacitance + + align:start position:0% +do I'm going to be trading capacitance + + + align:start position:0% +do I'm going to be trading capacitance +for inductance and I got to decide which + + align:start position:0% +for inductance and I got to decide which + + + align:start position:0% +for inductance and I got to decide which +I want you know which I don't like + + align:start position:0% +I want you know which I don't like + + + align:start position:0% +I want you know which I don't like +less okay now that doesn't mean you + + align:start position:0% +less okay now that doesn't mean you + + + align:start position:0% +less okay now that doesn't mean you +can't you know this tradeoff and I + + align:start position:0% +can't you know this tradeoff and I + + + align:start position:0% +can't you know this tradeoff and I +should say by the way one + + align:start position:0% +should say by the way one + + + align:start position:0% +should say by the way one +over um L Prime C + + align:start position:0% +over um L Prime C + + + align:start position:0% +over um L Prime C +Prime uh ends up being the speed of + + align:start position:0% +Prime uh ends up being the speed of + + + align:start position:0% +Prime uh ends up being the speed of +light squared okay so it's you know it's + + align:start position:0% +light squared okay so it's you know it's + + + align:start position:0% +light squared okay so it's you know it's +a physical constant mu m epon + + align:start position:0% +a physical constant mu m epon + + + align:start position:0% +a physical constant mu m epon +not but um that doesn't mean I can't do + + align:start position:0% +not but um that doesn't mean I can't do + + + align:start position:0% +not but um that doesn't mean I can't do +anything bad here that doesn't help me + + align:start position:0% +anything bad here that doesn't help me + + + align:start position:0% +anything bad here that doesn't help me +right if I thought about you know I'm + + align:start position:0% +right if I thought about you know I'm + + + align:start position:0% +right if I thought about you know I'm +going to carry some + + align:start position:0% +going to carry some + + + align:start position:0% +going to carry some +current over some distance you know I'm + + align:start position:0% +current over some distance you know I'm + + + align:start position:0% +current over some distance you know I'm +going to carry current here and it's + + align:start position:0% +going to carry current here and it's + + + align:start position:0% +going to carry current here and it's +going to return underneath here right if + + align:start position:0% +going to return underneath here right if + + + align:start position:0% +going to return underneath here right if +I put some piece of metal out here that + + align:start position:0% +I put some piece of metal out here that + + + align:start position:0% +I put some piece of metal out here that +doesn't really carry any current he can + + align:start position:0% +doesn't really carry any current he can + + + align:start position:0% +doesn't really carry any current he can +add capacitance without reducing + + align:start position:0% +add capacitance without reducing + + + align:start position:0% +add capacitance without reducing +inductance right so I can certainly do + + align:start position:0% +inductance right so I can certainly do + + + align:start position:0% +inductance right so I can certainly do +things to make both inductance and + + align:start position:0% +things to make both inductance and + + + align:start position:0% +things to make both inductance and +capacit accidents worse or make one of + + align:start position:0% +capacit accidents worse or make one of + + + align:start position:0% +capacit accidents worse or make one of +them worse without helping the other but + + align:start position:0% +them worse without helping the other but + + + align:start position:0% +them worse without helping the other but +when I get it down to the sort of the + + align:start position:0% +when I get it down to the sort of the + + + align:start position:0% +when I get it down to the sort of the +best interconnect strategy at some point + + align:start position:0% +best interconnect strategy at some point + + + align:start position:0% +best interconnect strategy at some point +you know if I put my trace and return + + align:start position:0% +you know if I put my trace and return + + + align:start position:0% +you know if I put my trace and return +close I'm making the inductance low and + + align:start position:0% +close I'm making the inductance low and + + + align:start position:0% +close I'm making the inductance low and +the capacit capacitance high and vice + + align:start position:0% +the capacit capacitance high and vice + + + align:start position:0% +the capacit capacitance high and vice +versa okay and you just got to think + + align:start position:0% +versa okay and you just got to think + + + align:start position:0% +versa okay and you just got to think +about which piece of Trace is it and + + align:start position:0% +about which piece of Trace is it and + + + align:start position:0% +about which piece of Trace is it and +what is it doing for + + align:start position:0% +what is it doing for + + + align:start position:0% +what is it doing for +you any question about that + + align:start position:0% + + + + align:start position:0% + +let's talk a little bit about more about + + align:start position:0% +let's talk a little bit about more about + + + align:start position:0% +let's talk a little bit about more about +this switching node here + + align:start position:0% +this switching node here + + + align:start position:0% +this switching node here +okay um one thing it does which we saw + + align:start position:0% +okay um one thing it does which we saw + + + align:start position:0% +okay um one thing it does which we saw +in the demo is it'll cause a bunch of + + align:start position:0% +in the demo is it'll cause a bunch of + + + align:start position:0% +in the demo is it'll cause a bunch of +ringing because you have excess + + align:start position:0% +ringing because you have excess + + + align:start position:0% +ringing because you have excess +capacitance at this node that you don't + + align:start position:0% +capacitance at this node that you don't + + + align:start position:0% +capacitance at this node that you don't +like but there are other capacitors is + + align:start position:0% +like but there are other capacitors is + + + align:start position:0% +like but there are other capacitors is +that node like the device capacitors and + + align:start position:0% +that node like the device capacitors and + + + align:start position:0% +that node like the device capacitors and +so forth but what really often hurts you + + align:start position:0% +so forth but what really often hurts you + + + align:start position:0% +so forth but what really often hurts you +is the capacitance of that node not to + + align:start position:0% +is the capacitance of that node not to + + + align:start position:0% +is the capacitance of that node not to +ground but to other stuff in your + + align:start position:0% +ground but to other stuff in your + + + align:start position:0% +ground but to other stuff in your +circuit so let's let's just + + align:start position:0% +circuit so let's let's just + + + align:start position:0% +circuit so let's let's just +imagine um this node is driven by the + + align:start position:0% +imagine um this node is driven by the + + + align:start position:0% +imagine um this node is driven by the +switching so there's a volt there sort + + align:start position:0% +switching so there's a volt there sort + + + align:start position:0% +switching so there's a volt there sort +of a square wave voltage here right so + + align:start position:0% +of a square wave voltage here right so + + + align:start position:0% +of a square wave voltage here right so +if I thought about modeling this I might + + align:start position:0% +if I thought about modeling this I might + + + align:start position:0% +if I thought about modeling this I might +say okay here's my here's my big Square + + align:start position:0% +say okay here's my here's my big Square + + + align:start position:0% +say okay here's my here's my big Square +wave + + align:start position:0% +wave + + + align:start position:0% +wave +voltage right this is going up and down + + align:start position:0% +voltage right this is going up and down + + + align:start position:0% +voltage right this is going up and down +like this okay + + align:start position:0% +like this okay + + + align:start position:0% +like this okay +and + + align:start position:0% +and + + + align:start position:0% +and +this piece of metal here forms one plate + + align:start position:0% +this piece of metal here forms one plate + + + align:start position:0% +this piece of metal here forms one plate +of a + + align:start position:0% +of a + + + align:start position:0% +of a +capacitor okay so maybe I think about + + align:start position:0% +capacitor okay so maybe I think about + + + align:start position:0% +capacitor okay so maybe I think about +that as being one plate here it is he's + + align:start position:0% +that as being one plate here it is he's + + + align:start position:0% +that as being one plate here it is he's +one plate of a + + align:start position:0% + + + + align:start position:0% + +capacitor all right what's the other + + align:start position:0% +capacitor all right what's the other + + + align:start position:0% +capacitor all right what's the other +plate of my capacitor well it depends + + align:start position:0% +plate of my capacitor well it depends + + + align:start position:0% +plate of my capacitor well it depends +what's around it but imagine + + align:start position:0% +what's around it but imagine + + + align:start position:0% +what's around it but imagine +nearby I have in my circuit for example + + align:start position:0% +nearby I have in my circuit for example + + + align:start position:0% +nearby I have in my circuit for example +suppose I have some control circuitry + + align:start position:0% +suppose I have some control circuitry + + + align:start position:0% +suppose I have some control circuitry +down here it's ground + + align:start position:0% +down here it's ground + + + align:start position:0% +down here it's ground +referenced right I have drivers and + + align:start position:0% +referenced right I have drivers and + + + align:start position:0% +referenced right I have drivers and +sensors and comparators are going to do + + align:start position:0% +sensors and comparators are going to do + + + align:start position:0% +sensors and comparators are going to do +all the computation for me right and + + align:start position:0% +all the computation for me right and + + + align:start position:0% +all the computation for me right and +maybe within this there's some very + + align:start position:0% +maybe within this there's some very + + + align:start position:0% +maybe within this there's some very +sensitive node maybe that's the input of + + align:start position:0% +sensitive node maybe that's the input of + + + align:start position:0% +sensitive node maybe that's the input of +a + + align:start position:0% +a + + + align:start position:0% +a +comparator or at the you know right + + align:start position:0% +comparator or at the you know right + + + align:start position:0% +comparator or at the you know right +where my error amplifier is my opamp and + + align:start position:0% +where my error amplifier is my opamp and + + + align:start position:0% +where my error amplifier is my opamp and +I can have some very high impedance + + align:start position:0% +I can have some very high impedance + + + align:start position:0% +I can have some very high impedance +nodes right so maybe I have a plate + + align:start position:0% +nodes right so maybe I have a plate + + + align:start position:0% +nodes right so maybe I have a plate +there that plate is just the metal of + + align:start position:0% +there that plate is just the metal of + + + align:start position:0% +there that plate is just the metal of +that node okay and you know it has some + + align:start position:0% +that node okay and you know it has some + + + align:start position:0% +that node okay and you know it has some +resistance too right so maybe my + + align:start position:0% +resistance too right so maybe my + + + align:start position:0% +resistance too right so maybe my +comparator has some resistance to ground + + align:start position:0% +comparator has some resistance to ground + + + align:start position:0% +comparator has some resistance to ground +so this is you know this white could be + + align:start position:0% +so this is you know this white could be + + + align:start position:0% +so this is you know this white could be +inside this box maybe there's a + + align:start position:0% +inside this box maybe there's a + + + align:start position:0% +inside this box maybe there's a +comparator and he has a positive input + + align:start position:0% +comparator and he has a positive input + + + align:start position:0% +comparator and he has a positive input +and there's some metal that I've got + + align:start position:0% +and there's some metal that I've got + + + align:start position:0% +and there's some metal that I've got +sitting right here that's the other + + align:start position:0% +sitting right here that's the other + + + align:start position:0% +sitting right here that's the other +plate of this capacitor okay does that + + align:start position:0% +plate of this capacitor okay does that + + + align:start position:0% +plate of this capacitor okay does that +make + + align:start position:0% +make + + + align:start position:0% +make +sense so if this voltage is here what is + + align:start position:0% +sense so if this voltage is here what is + + + align:start position:0% +sense so if this voltage is here what is +this voltage the induced voltage + + align:start position:0% +this voltage the induced voltage + + + align:start position:0% +this voltage the induced voltage +well simple RC divider what does that + + align:start position:0% +well simple RC divider what does that + + + align:start position:0% +well simple RC divider what does that +tell me it tells me I ought to be doing + + align:start position:0% +tell me it tells me I ought to be doing + + + align:start position:0% +tell me it tells me I ought to be doing +this I ought to be seeing a voltage that + + align:start position:0% +this I ought to be seeing a voltage that + + + align:start position:0% +this I ought to be seeing a voltage that +spikes up and Rings down and then and + + align:start position:0% +spikes up and Rings down and then and + + + align:start position:0% +spikes up and Rings down and then and +then spikes down and Rings up and vice + + align:start position:0% +then spikes down and Rings up and vice + + + align:start position:0% +then spikes down and Rings up and vice +versa right so this is the voltage I'm + + align:start position:0% +versa right so this is the voltage I'm + + + align:start position:0% +versa right so this is the voltage I'm +going to see here does that make sense + + align:start position:0% +going to see here does that make sense + + + align:start position:0% +going to see here does that make sense +everybody and maybe the energy in these + + align:start position:0% +everybody and maybe the energy in these + + + align:start position:0% +everybody and maybe the energy in these +spikes isn't very big but if that's the + + align:start position:0% +spikes isn't very big but if that's the + + + align:start position:0% +spikes isn't very big but if that's the +input to a comparator maybe I'm very + + align:start position:0% +input to a comparator maybe I'm very + + + align:start position:0% +input to a comparator maybe I'm very +unhappy right because if that comparator + + align:start position:0% +unhappy right because if that comparator + + + align:start position:0% +unhappy right because if that comparator +is determining when the switch turns on + + align:start position:0% +is determining when the switch turns on + + + align:start position:0% +is determining when the switch turns on +and off + + align:start position:0% +and off + + + align:start position:0% +and off +and I get a spike on that signal because + + align:start position:0% +and I get a spike on that signal because + + + align:start position:0% +and I get a spike on that signal because +of this capacitive injection I could be + + align:start position:0% +of this capacitive injection I could be + + + align:start position:0% +of this capacitive injection I could be +really + + align:start position:0% + + + + align:start position:0% + +unhappy any questions about + + align:start position:0% + + + + align:start position:0% + +that so what can I do about + + align:start position:0% +that so what can I do about + + + align:start position:0% +that so what can I do about +that one thing + + align:start position:0% +that one thing + + + align:start position:0% +that one thing +is we said you know the area the + + align:start position:0% +is we said you know the area the + + + align:start position:0% +is we said you know the area the +capacitance is related to the area I + + align:start position:0% +capacitance is related to the area I + + + align:start position:0% +capacitance is related to the area I +assume the two plate areas were the same + + align:start position:0% +assume the two plate areas were the same + + + align:start position:0% +assume the two plate areas were the same +here this is some small area that's this + + align:start position:0% +here this is some small area that's this + + + align:start position:0% +here this is some small area that's this +node + + align:start position:0% +node + + + align:start position:0% +node +this is some big area that's associated + + align:start position:0% +this is some big area that's associated + + + align:start position:0% +this is some big area that's associated +with carrying currents for my switching + + align:start position:0% +with carrying currents for my switching + + + align:start position:0% +with carrying currents for my switching +node one thing I want to do is make that + + align:start position:0% +node one thing I want to do is make that + + + align:start position:0% +node one thing I want to do is make that +as small as + + align:start position:0% +as small as + + + align:start position:0% +as small as +possible also keep the + + align:start position:0% +possible also keep the + + + align:start position:0% +possible also keep the +distance between this thing and this + + align:start position:0% +distance between this thing and this + + + align:start position:0% +distance between this thing and this +thing bigger so that the capacitance + + align:start position:0% +thing bigger so that the capacitance + + + align:start position:0% +thing bigger so that the capacitance +goes down right so I can kind of put + + align:start position:0% +goes down right so I can kind of put + + + align:start position:0% +goes down right so I can kind of put +them far apart farther as far as I can + + align:start position:0% +them far apart farther as far as I can + + + align:start position:0% +them far apart farther as far as I can +practically do it and reduce the areas + + align:start position:0% +practically do it and reduce the areas + + + align:start position:0% +practically do it and reduce the areas +and that will help me um minimize that + + align:start position:0% +and that will help me um minimize that + + + align:start position:0% +and that will help me um minimize that +capacitance that's causing noise does + + align:start position:0% +capacitance that's causing noise does + + + align:start position:0% +capacitance that's causing noise does +that make sense everybody + + align:start position:0% + + + + align:start position:0% + +what else could I do about that well + + align:start position:0% +what else could I do about that well + + + align:start position:0% +what else could I do about that well +another thing I could do about that is + + align:start position:0% +another thing I could do about that is + + + align:start position:0% +another thing I could do about that is +start to get smart about where those + + align:start position:0% +start to get smart about where those + + + align:start position:0% +start to get smart about where those +components are and what I put in between + + align:start position:0% +components are and what I put in between + + + align:start position:0% +components are and what I put in between +them okay so one thing I could do is put + + align:start position:0% +them okay so one thing I could do is put + + + align:start position:0% +them okay so one thing I could do is put +in what's known as a faraday Shield okay + + align:start position:0% +in what's known as a faraday Shield okay + + + align:start position:0% +in what's known as a faraday Shield okay +or lay out my circuit so I effectively + + align:start position:0% +or lay out my circuit so I effectively + + + align:start position:0% +or lay out my circuit so I effectively +get a faraday Shield what's a faraday + + align:start position:0% +get a faraday Shield what's a faraday + + + align:start position:0% +get a faraday Shield what's a faraday +Shield let me just say you know this is + + align:start position:0% +Shield let me just say you know this is + + + align:start position:0% +Shield let me just say you know this is +a model for what's going on right + + align:start position:0% +a model for what's going on right + + + align:start position:0% +a model for what's going on right +suppose I did this instead I said okay + + align:start position:0% +suppose I did this instead I said okay + + + align:start position:0% +suppose I did this instead I said okay +I have my switching node right it's + + align:start position:0% +I have my switching node right it's + + + align:start position:0% +I have my switching node right it's +switching up and down and I and I still + + align:start position:0% +switching up and down and I and I still + + + align:start position:0% +switching up and down and I and I still +have this you know maybe this is still a + + align:start position:0% +have this you know maybe this is still a + + + align:start position:0% +have this you know maybe this is still a +a i minimized it but I still got a + + align:start position:0% +a i minimized it but I still got a + + + align:start position:0% +a i minimized it but I still got a +certain plate area there and I've still + + align:start position:0% +certain plate area there and I've still + + + align:start position:0% +certain plate area there and I've still +you know I I need some area for + + align:start position:0% +you know I I need some area for + + + align:start position:0% +you know I I need some area for +my um I need some area for my switching + + align:start position:0% +my um I need some area for my switching + + + align:start position:0% +my um I need some area for my switching +node and he's still going to be a high + + align:start position:0% +node and he's still going to be a high + + + align:start position:0% +node and he's still going to be a high +impedance node the other thing I can do + + align:start position:0% +impedance node the other thing I can do + + + align:start position:0% +impedance node the other thing I can do +by the way is if I make this resistor + + align:start position:0% +by the way is if I make this resistor + + + align:start position:0% +by the way is if I make this resistor +smaller that starts to become + + align:start position:0% +smaller that starts to become + + + align:start position:0% +smaller that starts to become +less nasty but you know there's only so + + align:start position:0% +less nasty but you know there's only so + + + align:start position:0% +less nasty but you know there's only so +much I can do about that well what else + + align:start position:0% +much I can do about that well what else + + + align:start position:0% +much I can do about that well what else +could I do maybe I could come in and say + + align:start position:0% +could I do maybe I could come in and say + + + align:start position:0% +could I do maybe I could come in and say +okay let me put some piece of + + align:start position:0% +okay let me put some piece of + + + align:start position:0% +okay let me put some piece of +metal that sits + + align:start position:0% +metal that sits + + + align:start position:0% +metal that sits +between the noisy node and the thing the + + align:start position:0% +between the noisy node and the thing the + + + align:start position:0% +between the noisy node and the thing the +sensitive + + align:start position:0% +sensitive + + + align:start position:0% +sensitive +node and maybe I'll just take that piece + + align:start position:0% +node and maybe I'll just take that piece + + + align:start position:0% +node and maybe I'll just take that piece +of metal and I'll ground + + align:start position:0% +of metal and I'll ground + + + align:start position:0% +of metal and I'll ground +it okay so what would be the circuit + + align:start position:0% +it okay so what would be the circuit + + + align:start position:0% +it okay so what would be the circuit +model for this the circuit model for + + align:start position:0% +model for this the circuit model for + + + align:start position:0% +model for this the circuit model for +this would be the following right I have + + align:start position:0% +this would be the following right I have + + + align:start position:0% +this would be the following right I have +my I this is sort of a circuit model + + align:start position:0% +my I this is sort of a circuit model + + + align:start position:0% +my I this is sort of a circuit model +already but what I have is you know + + align:start position:0% +already but what I have is you know + + + align:start position:0% +already but what I have is you know +essentially one capacitor that's tied to + + align:start position:0% +essentially one capacitor that's tied to + + + align:start position:0% +essentially one capacitor that's tied to +ground right I have the capacitance + + align:start position:0% +ground right I have the capacitance + + + align:start position:0% +ground right I have the capacitance +between pink and green and I'm grounding + + align:start position:0% +between pink and green and I'm grounding + + + align:start position:0% +between pink and green and I'm grounding +green and then I have the capacitance + + align:start position:0% +green and then I have the capacitance + + + align:start position:0% +green and then I have the capacitance +between green and + + align:start position:0% +between green and + + + align:start position:0% +between green and +yellow right so here's my other + + align:start position:0% +yellow right so here's my other + + + align:start position:0% +yellow right so here's my other +capacitance that goes to my sensitive + + align:start position:0% +capacitance that goes to my sensitive + + + align:start position:0% +capacitance that goes to my sensitive +node + + align:start position:0% + + + + align:start position:0% + +and here's now the voltage I'm inducing + + align:start position:0% +and here's now the voltage I'm inducing + + + align:start position:0% +and here's now the voltage I'm inducing +on the sensitive node what voltage would + + align:start position:0% +on the sensitive node what voltage would + + + align:start position:0% +on the sensitive node what voltage would +I be inducing due to this Square wave in + + align:start position:0% +I be inducing due to this Square wave in + + + align:start position:0% +I be inducing due to this Square wave in +this + + align:start position:0% + + + + align:start position:0% + +case am I going to see a voltage over + + align:start position:0% +case am I going to see a voltage over + + + align:start position:0% +case am I going to see a voltage over +here in this + + align:start position:0% + + + + align:start position:0% + +circuit no right I he's on he's got a + + align:start position:0% +circuit no right I he's on he's got a + + + align:start position:0% +circuit no right I he's on he's got a +grounded capacitor over here okay so + + align:start position:0% +grounded capacitor over here okay so + + + align:start position:0% +grounded capacitor over here okay so +essentially this piece of metal acts as + + align:start position:0% +essentially this piece of metal acts as + + + align:start position:0% +essentially this piece of metal acts as +an electrostatic Shield right if it was + + align:start position:0% +an electrostatic Shield right if it was + + + align:start position:0% +an electrostatic Shield right if it was +all the way around you'd call it a + + align:start position:0% +all the way around you'd call it a + + + align:start position:0% +all the way around you'd call it a +faraday cage okay but it prevents this + + align:start position:0% +faraday cage okay but it prevents this + + + align:start position:0% +faraday cage okay but it prevents this +noisy signal from injecting onto this + + align:start position:0% +noisy signal from injecting onto this + + + align:start position:0% +noisy signal from injecting onto this +well how would I do that one way to do + + align:start position:0% +well how would I do that one way to do + + + align:start position:0% +well how would I do that one way to do +that is maybe I put this switching Noe + + align:start position:0% +that is maybe I put this switching Noe + + + align:start position:0% +that is maybe I put this switching Noe +on one side of my circuit board I have a + + align:start position:0% +on one side of my circuit board I have a + + + align:start position:0% +on one side of my circuit board I have a +ground plane in between them and I put + + align:start position:0% +ground plane in between them and I put + + + align:start position:0% +ground plane in between them and I put +my control circuitry on the other side + + align:start position:0% +my control circuitry on the other side + + + align:start position:0% +my control circuitry on the other side +of the circuit board is sort of shielded + + align:start position:0% +of the circuit board is sort of shielded + + + align:start position:0% +of the circuit board is sort of shielded +or hidden from the high switching + + align:start position:0% +or hidden from the high switching + + + align:start position:0% +or hidden from the high switching +node that make sense + + align:start position:0% +node that make sense + + + align:start position:0% +node that make sense +everybody now you can't always do that + + align:start position:0% +everybody now you can't always do that + + + align:start position:0% +everybody now you can't always do that +what else could you do if you have + + align:start position:0% +what else could you do if you have + + + align:start position:0% +what else could you do if you have +really sensitive stuff so suppose I had + + align:start position:0% +really sensitive stuff so suppose I had + + + align:start position:0% +really sensitive stuff so suppose I had +a radio receiver right next to my + + align:start position:0% +a radio receiver right next to my + + + align:start position:0% +a radio receiver right next to my +switching node circuit + + align:start position:0% +switching node circuit + + + align:start position:0% +switching node circuit +right is that a good thing no but you + + align:start position:0% +right is that a good thing no but you + + + align:start position:0% +right is that a good thing no but you +know some days you don't get a choice + + align:start position:0% +know some days you don't get a choice + + + align:start position:0% +know some days you don't get a choice +right you can actually + + align:start position:0% +right you can actually + + + align:start position:0% +right you can actually +buy for printed circuit board Mount + + align:start position:0% +buy for printed circuit board Mount + + + align:start position:0% +buy for printed circuit board Mount +little shielding cans so basically is + + align:start position:0% +little shielding cans so basically is + + + align:start position:0% +little shielding cans so basically is +like it'll be it'll run around on the + + align:start position:0% +like it'll be it'll run around on the + + + align:start position:0% +like it'll be it'll run around on the +circuit board and provide a side edge + + align:start position:0% +circuit board and provide a side edge + + + align:start position:0% +circuit board and provide a side edge +and then put a little cap on it and you + + align:start position:0% +and then put a little cap on it and you + + + align:start position:0% +and then put a little cap on it and you +can put your whole your radio receiver + + align:start position:0% +can put your whole your radio receiver + + + align:start position:0% +can put your whole your radio receiver +or whatever very sensitive noise noise + + align:start position:0% +or whatever very sensitive noise noise + + + align:start position:0% +or whatever very sensitive noise noise +sensitive element inside of there so + + align:start position:0% +sensitive element inside of there so + + + align:start position:0% +sensitive element inside of there so +actually if you take a w take aart a WI + + align:start position:0% +actually if you take a w take aart a WI + + + align:start position:0% +actually if you take a w take aart a WI +router or something like that you'll + + align:start position:0% +router or something like that you'll + + + align:start position:0% +router or something like that you'll +often see these little kind of metal + + align:start position:0% +often see these little kind of metal + + + align:start position:0% +often see these little kind of metal +boxes at the top will pop off and and + + align:start position:0% +boxes at the top will pop off and and + + + align:start position:0% +boxes at the top will pop off and and +some of the RF stuff will be in there + + align:start position:0% +some of the RF stuff will be in there + + + align:start position:0% +some of the RF stuff will be in there +that's both to keep the RF noise in and + + align:start position:0% +that's both to keep the RF noise in and + + + align:start position:0% +that's both to keep the RF noise in and +to keep the external stuff out but you + + align:start position:0% +to keep the external stuff out but you + + + align:start position:0% +to keep the external stuff out but you +could do that with your control + + align:start position:0% +could do that with your control + + + align:start position:0% +could do that with your control +circuitry too if you had to but mostly + + align:start position:0% +circuitry too if you had to but mostly + + + align:start position:0% +circuitry too if you had to but mostly +what do you do you try to be smart by + + align:start position:0% +what do you do you try to be smart by + + + align:start position:0% +what do you do you try to be smart by +not putting it close or maybe putting it + + align:start position:0% +not putting it close or maybe putting it + + + align:start position:0% +not putting it close or maybe putting it +on the other side of the circuit board + + align:start position:0% +on the other side of the circuit board + + + align:start position:0% +on the other side of the circuit board +and getting yourself an electrostatic + + align:start position:0% +and getting yourself an electrostatic + + + align:start position:0% +and getting yourself an electrostatic +shield in there + + align:start position:0% +shield in there + + + align:start position:0% +shield in there +okay questions about that + + align:start position:0% + + + + align:start position:0% + +I should give + + align:start position:0% +I should give + + + align:start position:0% +I should give +you a little + + align:start position:0% +you a little + + + align:start position:0% +you a little +warning right when I did this + + align:start position:0% +warning right when I did this + + + align:start position:0% +warning right when I did this +approximation and hopefully get the + + align:start position:0% +approximation and hopefully get the + + + align:start position:0% +approximation and hopefully get the +right actual equation here to get the + + align:start position:0% +right actual equation here to get the + + + align:start position:0% +right actual equation here to get the +inductance and the capacitance in both + + align:start position:0% +inductance and the capacitance in both + + + align:start position:0% +inductance and the capacitance in both +cases I was neglecting fringing Fields + + align:start position:0% +cases I was neglecting fringing Fields + + + align:start position:0% +cases I was neglecting fringing Fields +right so when does this inductance + + align:start position:0% +right so when does this inductance + + + align:start position:0% +right so when does this inductance +equation really work well it works well + + align:start position:0% +equation really work well it works well + + + align:start position:0% +equation really work well it works well +when you have two really kind of wide + + align:start position:0% +when you have two really kind of wide + + + align:start position:0% +when you have two really kind of wide +conductors put close together so maybe I + + align:start position:0% +conductors put close together so maybe I + + + align:start position:0% +conductors put close together so maybe I +send my Gate Drive signal out and I + + align:start position:0% +send my Gate Drive signal out and I + + + align:start position:0% +send my Gate Drive signal out and I +return it right underneath that becomes + + align:start position:0% +return it right underneath that becomes + + + align:start position:0% +return it right underneath that becomes +a pretty good approximation to the loop + + align:start position:0% +a pretty good approximation to the loop + + + align:start position:0% +a pretty good approximation to the loop +inductance you're going to get or in a + + align:start position:0% +inductance you're going to get or in a + + + align:start position:0% +inductance you're going to get or in a +capacitance if I have two pieces of + + align:start position:0% +capacitance if I have two pieces of + + + align:start position:0% +capacitance if I have two pieces of +metal that are of the same size and + + align:start position:0% +metal that are of the same size and + + + align:start position:0% +metal that are of the same size and +they're really close together that's a + + align:start position:0% +they're really close together that's a + + + align:start position:0% +they're really close together that's a +pretty good approximation when I start + + align:start position:0% +pretty good approximation when I start + + + align:start position:0% +pretty good approximation when I start +to pull them apart what happens well I + + align:start position:0% +to pull them apart what happens well I + + + align:start position:0% +to pull them apart what happens well I +you know in the capacitance case + + align:start position:0% + + + + align:start position:0% + +right for example this approximation + + align:start position:0% +right for example this approximation + + + align:start position:0% +right for example this approximation +is really just capturing the fields that + + align:start position:0% +is really just capturing the fields that + + + align:start position:0% +is really just capturing the fields that +are directly between these plates that's + + align:start position:0% +are directly between these plates that's + + + align:start position:0% +are directly between these plates that's +how you get to this equation once you + + align:start position:0% +how you get to this equation once you + + + align:start position:0% +how you get to this equation once you +start to have significant fringing + + align:start position:0% +start to have significant fringing + + + align:start position:0% +start to have significant fringing +Fields right the distance between the + + align:start position:0% +Fields right the distance between the + + + align:start position:0% +Fields right the distance between the +plates is long compared to the sort of + + align:start position:0% +plates is long compared to the sort of + + + align:start position:0% +plates is long compared to the sort of +the Coss the areas or the lengths on the + + align:start position:0% +the Coss the areas or the lengths on the + + + align:start position:0% +the Coss the areas or the lengths on the +other dimensions of the plate then these + + align:start position:0% +other dimensions of the plate then these + + + align:start position:0% +other dimensions of the plate then these +fringing Fields start to become + + align:start position:0% +fringing Fields start to become + + + align:start position:0% +fringing Fields start to become +important okay so you can't necessarily + + align:start position:0% +important okay so you can't necessarily + + + align:start position:0% +important okay so you can't necessarily +think of oh jeez you know my Capac is + + align:start position:0% +think of oh jeez you know my Capac is + + + align:start position:0% +think of oh jeez you know my Capac is +going to go exactly as the inverse of + + align:start position:0% +going to go exactly as the inverse of + + + align:start position:0% +going to go exactly as the inverse of +the distance between whatever things I'm + + align:start position:0% +the distance between whatever things I'm + + + align:start position:0% +the distance between whatever things I'm +going to have that's true when they're + + align:start position:0% +going to have that's true when they're + + + align:start position:0% +going to have that's true when they're +really close together but less true as + + align:start position:0% +really close together but less true as + + + align:start position:0% +really close together but less true as +you start to pull them far apart so a + + align:start position:0% +you start to pull them far apart so a + + + align:start position:0% +you start to pull them far apart so a +classic analysis you might look at is + + align:start position:0% +classic analysis you might look at is + + + align:start position:0% +classic analysis you might look at is +like + + align:start position:0% +like + + + align:start position:0% +like +this suppose I took a + + align:start position:0% +this suppose I took a + + + align:start position:0% +this suppose I took a +sphere of radius R + + align:start position:0% +sphere of radius R + + + align:start position:0% +sphere of radius R +KN okay and I'm going to put a little + + align:start position:0% +KN okay and I'm going to put a little + + + align:start position:0% +KN okay and I'm going to put a little +charge on that sphere plus + + align:start position:0% +charge on that sphere plus + + + align:start position:0% +charge on that sphere plus +Q right right total net charge on the + + align:start position:0% +Q right right total net charge on the + + + align:start position:0% +Q right right total net charge on the +sphere and let me make the other plate + + align:start position:0% +sphere and let me make the other plate + + + align:start position:0% +sphere and let me make the other plate +of my capacitor a sphere that's around + + align:start position:0% +of my capacitor a sphere that's around + + + align:start position:0% +of my capacitor a sphere that's around +it at some you know Big + + align:start position:0% +it at some you know Big + + + align:start position:0% +it at some you know Big +R okay there's that itself forms a + + align:start position:0% +R okay there's that itself forms a + + + align:start position:0% +R okay there's that itself forms a +capacitance right where I have electric + + align:start position:0% +capacitance right where I have electric + + + align:start position:0% +capacitance right where I have electric +fields that are sort of you know I'm + + align:start position:0% +fields that are sort of you know I'm + + + align:start position:0% +fields that are sort of you know I'm +going to have mirror + + align:start position:0% +going to have mirror + + + align:start position:0% +going to have mirror +charges distributed on my outer plate on + + align:start position:0% +charges distributed on my outer plate on + + + align:start position:0% +charges distributed on my outer plate on +my outer sphere okay and I'm going to + + align:start position:0% +my outer sphere okay and I'm going to + + + align:start position:0% +my outer sphere okay and I'm going to +have electric field pointing outward + + align:start position:0% +have electric field pointing outward + + + align:start position:0% +have electric field pointing outward +here like this does that make sense + + align:start position:0% +here like this does that make sense + + + align:start position:0% +here like this does that make sense +everybody the picture I'm drawing I've + + align:start position:0% +everybody the picture I'm drawing I've + + + align:start position:0% +everybody the picture I'm drawing I've +got an inner sphere and an outer sphere + + align:start position:0% +got an inner sphere and an outer sphere + + + align:start position:0% +got an inner sphere and an outer sphere +and I want to calculate the capacitance + + align:start position:0% +and I want to calculate the capacitance + + + align:start position:0% +and I want to calculate the capacitance +between them and why am I doing spheres + + align:start position:0% +between them and why am I doing spheres + + + align:start position:0% +between them and why am I doing spheres +because I'm lazy and the Math's easy + + align:start position:0% +because I'm lazy and the Math's easy + + + align:start position:0% +because I'm lazy and the Math's easy +okay so think of whatever you got as + + align:start position:0% +okay so think of whatever you got as + + + align:start position:0% +okay so think of whatever you got as +being a little sphere okay but here's + + align:start position:0% +being a little sphere okay but here's + + + align:start position:0% +being a little sphere okay but here's +what I'm going to do let me make the + + align:start position:0% +what I'm going to do let me make the + + + align:start position:0% +what I'm going to do let me make the +outer sphere go off to + + align:start position:0% +outer sphere go off to + + + align:start position:0% +outer sphere go off to +Infinity right so I can say what is the + + align:start position:0% +Infinity right so I can say what is the + + + align:start position:0% +Infinity right so I can say what is the +capacitance of this little sphere of + + align:start position:0% +capacitance of this little sphere of + + + align:start position:0% +capacitance of this little sphere of +metal to the rest of the universe + + align:start position:0% +metal to the rest of the universe + + + align:start position:0% +metal to the rest of the universe +okay well what is that well we can + + align:start position:0% +okay well what is that well we can + + + align:start position:0% +okay well what is that well we can +calculate + + align:start position:0% +calculate + + + align:start position:0% +calculate +that + + align:start position:0% +that + + + align:start position:0% +that +um if I take the integral of Epsilon KN + + align:start position:0% +um if I take the integral of Epsilon KN + + + align:start position:0% +um if I take the integral of Epsilon KN +a over uh + + align:start position:0% +a over uh + + + align:start position:0% +a over uh +the the integral of Epsilon e Doda is + + align:start position:0% +the the integral of Epsilon e Doda is + + + align:start position:0% +the the integral of Epsilon e Doda is +equal to the net charge I'm enclosing + + align:start position:0% +equal to the net charge I'm enclosing + + + align:start position:0% +equal to the net charge I'm enclosing +right so um if I then figured this out + + align:start position:0% +right so um if I then figured this out + + + align:start position:0% +right so um if I then figured this out +suppose I took a a sphere around my + + align:start position:0% +suppose I took a a sphere around my + + + align:start position:0% +suppose I took a a sphere around my +inner sphere and I said what's the + + align:start position:0% +inner sphere and I said what's the + + + align:start position:0% +inner sphere and I said what's the +radial electric field what is the E subr + + align:start position:0% +radial electric field what is the E subr + + + align:start position:0% +radial electric field what is the E subr +the radial electric field going to be + + align:start position:0% +the radial electric field going to be + + + align:start position:0% +the radial electric field going to be +you know what is this electric field + + align:start position:0% +you know what is this electric field + + + align:start position:0% +you know what is this electric field +going to be at some distance R from the + + align:start position:0% +going to be at some distance R from the + + + align:start position:0% +going to be at some distance R from the +center right that's going to be equal to + + align:start position:0% +center right that's going to be equal to + + + align:start position:0% +center right that's going to be equal to +e subr is just going to be equal to Q + + align:start position:0% +e subr is just going to be equal to Q + + + align:start position:0% +e subr is just going to be equal to Q +over Epsilon times the area which is 4 + + align:start position:0% +over Epsilon times the area which is 4 + + + align:start position:0% +over Epsilon times the area which is 4 +pi r 2 + + align:start position:0% + + + + align:start position:0% + +right what's the voltage that's going to + + align:start position:0% +right what's the voltage that's going to + + + align:start position:0% +right what's the voltage that's going to +be + + align:start position:0% +be + + + align:start position:0% +be +between the outer sphere and the inner + + align:start position:0% +between the outer sphere and the inner + + + align:start position:0% +between the outer sphere and the inner +sphere well the voltage is going to be + + align:start position:0% +sphere well the voltage is going to be + + + align:start position:0% +sphere well the voltage is going to be +equal + + align:start position:0% +equal + + + align:start position:0% +equal +to minus the integral from of es subar + + align:start position:0% +to minus the integral from of es subar + + + align:start position:0% +to minus the integral from of es subar +Dr or I could write that just to be easy + + align:start position:0% +Dr or I could write that just to be easy + + + align:start position:0% +Dr or I could write that just to be easy +as Infinity to R not the integral from + + align:start position:0% +as Infinity to R not the integral from + + + align:start position:0% +as Infinity to R not the integral from +Infinity out to the surface of my little + + align:start position:0% +Infinity out to the surface of my little + + + align:start position:0% +Infinity out to the surface of my little +piece of metal that's got charge on + + align:start position:0% +piece of metal that's got charge on + + + align:start position:0% +piece of metal that's got charge on +it of uh Q over Epsilon * 4i r^ 2 which + + align:start position:0% +it of uh Q over Epsilon * 4i r^ 2 which + + + align:start position:0% +it of uh Q over Epsilon * 4i r^ 2 which +is just going to be equal to Q + + align:start position:0% +is just going to be equal to Q + + + align:start position:0% +is just going to be equal to Q +/ uh Epsilon over 4 pi r + + align:start position:0% +/ uh Epsilon over 4 pi r + + + align:start position:0% +/ uh Epsilon over 4 pi r +right and that means that Q if I write + + align:start position:0% +right and that means that Q if I write + + + align:start position:0% +right and that means that Q if I write +this Q is just going to be equal to V * + + align:start position:0% +this Q is just going to be equal to V * + + + align:start position:0% +this Q is just going to be equal to V * +Epsilon * 4i r + + align:start position:0% +Epsilon * 4i r + + + align:start position:0% +Epsilon * 4i r +r r KN it's the radius of this little + + align:start position:0% +r r KN it's the radius of this little + + + align:start position:0% +r r KN it's the radius of this little +sphere R KN + + align:start position:0% +sphere R KN + + + align:start position:0% +sphere R KN +okay but we know that Q is equal to + + align:start position:0% + + + + align:start position:0% + +CV right so this must be the + + align:start position:0% + + + + align:start position:0% + +capacitance okay so I'm kind of taking + + align:start position:0% +capacitance okay so I'm kind of taking + + + align:start position:0% +capacitance okay so I'm kind of taking +the other case where all of my field is + + align:start position:0% +the other case where all of my field is + + + align:start position:0% +the other case where all of my field is +fringing field out to the universe + + align:start position:0% +fringing field out to the universe + + + align:start position:0% +fringing field out to the universe +okay and in this case the capacitance to + + align:start position:0% +okay and in this case the capacitance to + + + align:start position:0% +okay and in this case the capacitance to +the universe from some little sphere of + + align:start position:0% +the universe from some little sphere of + + + align:start position:0% +the universe from some little sphere of +metal that I've got sitting here is + + align:start position:0% +metal that I've got sitting here is + + + align:start position:0% +metal that I've got sitting here is +exactly the dialectric which presumably + + align:start position:0% +exactly the dialectric which presumably + + + align:start position:0% +exactly the dialectric which presumably +if it's free space it's Epsilon KN Time + + align:start position:0% +if it's free space it's Epsilon KN Time + + + align:start position:0% +if it's free space it's Epsilon KN Time +4 Pi * the radius of the sphere so it's + + align:start position:0% +4 Pi * the radius of the sphere so it's + + + align:start position:0% +4 Pi * the radius of the sphere so it's +related to the square root of the area + + align:start position:0% +related to the square root of the area + + + align:start position:0% +related to the square root of the area +of the sphere if I increase the area of + + align:start position:0% +of the sphere if I increase the area of + + + align:start position:0% +of the sphere if I increase the area of +this thing the capacitance to the + + align:start position:0% +this thing the capacitance to the + + + align:start position:0% +this thing the capacitance to the +universe is not zero even though the + + align:start position:0% +universe is not zero even though the + + + align:start position:0% +universe is not zero even though the +universe is infinitely far away it's + + align:start position:0% +universe is infinitely far away it's + + + align:start position:0% +universe is infinitely far away it's +some finite amount related to the area + + align:start position:0% +some finite amount related to the area + + + align:start position:0% +some finite amount related to the area +or the radius of the thing I've got okay + + align:start position:0% +or the radius of the thing I've got okay + + + align:start position:0% +or the radius of the thing I've got okay +so that's like this basically a long way + + align:start position:0% +so that's like this basically a long way + + + align:start position:0% +so that's like this basically a long way +of saying when I make things space far + + align:start position:0% +of saying when I make things space far + + + align:start position:0% +of saying when I make things space far +apart fringing becomes very very + + align:start position:0% +apart fringing becomes very very + + + align:start position:0% +apart fringing becomes very very +important and I can get you know nonzero + + align:start position:0% +important and I can get you know nonzero + + + align:start position:0% +important and I can get you know nonzero +capacitances right or significant + + align:start position:0% +capacitances right or significant + + + align:start position:0% +capacitances right or significant +capacitances and in that light the only + + align:start position:0% +capacitances and in that light the only + + + align:start position:0% +capacitances and in that light the only +way you can really make that capacit + + align:start position:0% +way you can really make that capacit + + + align:start position:0% +way you can really make that capacit +smaller is to basically make R KN + + align:start position:0% +smaller is to basically make R KN + + + align:start position:0% +smaller is to basically make R KN +smaller or Mak basically make the area + + align:start position:0% +smaller or Mak basically make the area + + + align:start position:0% +smaller or Mak basically make the area +of the thing that you're worried about + + align:start position:0% +of the thing that you're worried about + + + align:start position:0% +of the thing that you're worried about +spraying field out smaller so its + + align:start position:0% +spraying field out smaller so its + + + align:start position:0% +spraying field out smaller so its +capacitance to other stuff will be + + align:start position:0% + + + + align:start position:0% + +smaller questions about + + align:start position:0% + + + + align:start position:0% + +that so this is just sort of a case + + align:start position:0% +that so this is just sort of a case + + + align:start position:0% +that so this is just sort of a case +where you know physics + + align:start position:0% +where you know physics + + + align:start position:0% +where you know physics +101 leads you to some conclusions about + + align:start position:0% +101 leads you to some conclusions about + + + align:start position:0% +101 leads you to some conclusions about +how you should lay your circuits out + + align:start position:0% +how you should lay your circuits out + + + align:start position:0% +how you should lay your circuits out +which comes back to + + align:start position:0% + + + + align:start position:0% + +make your Loops very tight and you I + + align:start position:0% +make your Loops very tight and you I + + + align:start position:0% +make your Loops very tight and you I +could make this I could have done the + + align:start position:0% +could make this I could have done the + + + align:start position:0% +could make this I could have done the +same analysis for finding inductances of + + align:start position:0% +same analysis for finding inductances of + + + align:start position:0% +same analysis for finding inductances of +loops and so so forth right you make + + align:start position:0% +loops and so so forth right you make + + + align:start position:0% +loops and so so forth right you make +your Loop tight you spread the area you + + align:start position:0% +your Loop tight you spread the area you + + + align:start position:0% +your Loop tight you spread the area you +spread the current out to get the + + align:start position:0% +spread the current out to get the + + + align:start position:0% +spread the current out to get the +inductance low so and and make the loop + + align:start position:0% +inductance low so and and make the loop + + + align:start position:0% +inductance low so and and make the loop +very + + align:start position:0% +very + + + align:start position:0% +very +tight don't use excess Loop don't use + + align:start position:0% +tight don't use excess Loop don't use + + + align:start position:0% +tight don't use excess Loop don't use +excess Trace area especially at these + + align:start position:0% +excess Trace area especially at these + + + align:start position:0% +excess Trace area especially at these +this Loop and this node + + align:start position:0% + + + + align:start position:0% + +okay if you going to go analyze a che + + align:start position:0% +okay if you going to go analyze a che + + + align:start position:0% +okay if you going to go analyze a che +converter or some other kind of + + align:start position:0% +converter or some other kind of + + + align:start position:0% +converter or some other kind of +converter the which Loop you care about + + align:start position:0% +converter the which Loop you care about + + + align:start position:0% +converter the which Loop you care about +is different which nodes you care about + + align:start position:0% +is different which nodes you care about + + + align:start position:0% +is different which nodes you care about +are different but they're usually the + + align:start position:0% +are different but they're usually the + + + align:start position:0% +are different but they're usually the +ones with the square wave currents in + + align:start position:0% +ones with the square wave currents in + + + align:start position:0% +ones with the square wave currents in +them and the square wave voltages on or + + align:start position:0% +them and the square wave voltages on or + + + align:start position:0% +them and the square wave voltages on or +the high dvdt or didt elements on them + + align:start position:0% +the high dvdt or didt elements on them + + + align:start position:0% +the high dvdt or didt elements on them +okay and small changes can make a big + + align:start position:0% +okay and small changes can make a big + + + align:start position:0% +okay and small changes can make a big +difference questions about any of that + + align:start position:0% + + + + align:start position:0% + +let me just talk about a couple of other + + align:start position:0% +let me just talk about a couple of other + + + align:start position:0% +let me just talk about a couple of other +things that I've glossed over or just + + align:start position:0% +things that I've glossed over or just + + + align:start position:0% +things that I've glossed over or just +not it's not that I've glossed over I've + + align:start position:0% +not it's not that I've glossed over I've + + + align:start position:0% +not it's not that I've glossed over I've +just not worried about them uh and these + + align:start position:0% +just not worried about them uh and these + + + align:start position:0% +just not worried about them uh and these +again are practical implementation + + align:start position:0% +again are practical implementation + + + align:start position:0% +again are practical implementation +issues which are important but you know + + align:start position:0% +issues which are important but you know + + + align:start position:0% +issues which are important but you know +you got to worry about them after you + + align:start position:0% +you got to worry about them after you + + + align:start position:0% +you got to worry about them after you +worry about the rest of your + + align:start position:0% +worry about the rest of your + + + align:start position:0% +worry about the rest of your +system let's think about driving the + + align:start position:0% +system let's think about driving the + + + align:start position:0% +system let's think about driving the +gates of our uh + + align:start position:0% +gates of our uh + + + align:start position:0% +gates of our uh +converters a Gates of our transistors + + align:start position:0% +converters a Gates of our transistors + + + align:start position:0% +converters a Gates of our transistors +right so if I think about my mosfet so + + align:start position:0% +right so if I think about my mosfet so + + + align:start position:0% +right so if I think about my mosfet so +suppose I I don't know suppose I make a + + align:start position:0% +suppose I I don't know suppose I make a + + + align:start position:0% +suppose I I don't know suppose I make a +boost converter for example so I've been + + align:start position:0% +boost converter for example so I've been + + + align:start position:0% +boost converter for example so I've been +talking about Buck converters now I'll + + align:start position:0% +talking about Buck converters now I'll + + + align:start position:0% +talking about Buck converters now I'll +talk about boost converters right I'm + + align:start position:0% +talk about boost converters right I'm + + + align:start position:0% +talk about boost converters right I'm +going to + + align:start position:0% + + + + align:start position:0% + +have some circuit here and I'm going to + + align:start position:0% +have some circuit here and I'm going to + + + align:start position:0% +have some circuit here and I'm going to +drive him right and usually what's going + + align:start position:0% +drive him right and usually what's going + + + align:start position:0% +drive him right and usually what's going +to be here is there's going to be some + + align:start position:0% +to be here is there's going to be some + + + align:start position:0% +to be here is there's going to be some +circuit which is making switching + + align:start position:0% +circuit which is making switching + + + align:start position:0% +circuit which is making switching +decisions it's powered from some low + + align:start position:0% +decisions it's powered from some low + + + align:start position:0% +decisions it's powered from some low +voltage + + align:start position:0% +voltage + + + align:start position:0% +voltage +Supply and it's you know it's got some + + align:start position:0% +Supply and it's you know it's got some + + + align:start position:0% +Supply and it's you know it's got some +input that's telling me when to switch + + align:start position:0% +input that's telling me when to switch + + + align:start position:0% +input that's telling me when to switch +this transistor + + align:start position:0% +this transistor + + + align:start position:0% +this transistor +right + + align:start position:0% +right + + + align:start position:0% +right +um what does the input of that + + align:start position:0% +um what does the input of that + + + align:start position:0% +um what does the input of that +transistor look like well you know this + + align:start position:0% +transistor look like well you know this + + + align:start position:0% +transistor look like well you know this +thing in him the last thing between me + + align:start position:0% +thing in him the last thing between me + + + align:start position:0% +thing in him the last thing between me +and my switch is some sort of gate + + align:start position:0% +and my switch is some sort of gate + + + align:start position:0% +and my switch is some sort of gate +driver right which is going to be + + align:start position:0% +driver right which is going to be + + + align:start position:0% +driver right which is going to be +powered from some voltage and he's got + + align:start position:0% +powered from some voltage and he's got + + + align:start position:0% +powered from some voltage and he's got +some signal coming + + align:start position:0% +some signal coming + + + align:start position:0% +some signal coming +in and he's going to try to turn this + + align:start position:0% +in and he's going to try to turn this + + + align:start position:0% +in and he's going to try to turn this +transistor on and off right so if I I + + align:start position:0% +transistor on and off right so if I I + + + align:start position:0% +transistor on and off right so if I I +thought about my + + align:start position:0% + + + + align:start position:0% + +transistor right here I'm going to I'm + + align:start position:0% +transistor right here I'm going to I'm + + + align:start position:0% +transistor right here I'm going to I'm +going to drive this with some Square + + align:start position:0% +going to drive this with some Square + + + align:start position:0% +going to drive this with some Square +wave + + align:start position:0% +wave + + + align:start position:0% +wave +voltage and I I need to remember that + + align:start position:0% +voltage and I I need to remember that + + + align:start position:0% +voltage and I I need to remember that +this transistor is going to have some + + align:start position:0% +this transistor is going to have some + + + align:start position:0% +this transistor is going to have some +gate Source + + align:start position:0% + + + + align:start position:0% + +capacitance he's going to have some + + align:start position:0% +capacitance he's going to have some + + + align:start position:0% +capacitance he's going to have some +drain Source capacitance but he's also + + align:start position:0% +drain Source capacitance but he's also + + + align:start position:0% +drain Source capacitance but he's also +importantly going to have some gate to + + align:start position:0% +importantly going to have some gate to + + + align:start position:0% +importantly going to have some gate to +drain + + align:start position:0% +drain + + + align:start position:0% +drain +capacitance + + align:start position:0% +capacitance + + + align:start position:0% +capacitance +okay and and this gate to drain + + align:start position:0% +okay and and this gate to drain + + + align:start position:0% +okay and and this gate to drain +capacitance actually has a significant + + align:start position:0% +capacitance actually has a significant + + + align:start position:0% +capacitance actually has a significant +influence especially in the case when + + align:start position:0% +influence especially in the case when + + + align:start position:0% +influence especially in the case when +suppose I'm driving this between you + + align:start position:0% +suppose I'm driving this between you + + + align:start position:0% +suppose I'm driving this between you +know 0 and 10 volts or something or 0 + + align:start position:0% +know 0 and 10 volts or something or 0 + + + align:start position:0% +know 0 and 10 volts or something or 0 +and 5 volts if it's a a lower you know a + + align:start position:0% +and 5 volts if it's a a lower you know a + + + align:start position:0% +and 5 volts if it's a a lower you know a +logic level kind of device all right but + + align:start position:0% +logic level kind of device all right but + + + align:start position:0% +logic level kind of device all right but +maybe this drain node is switching by + + align:start position:0% +maybe this drain node is switching by + + + align:start position:0% +maybe this drain node is switching by +hundreds of volts so this capacitance is + + align:start position:0% +hundreds of volts so this capacitance is + + + align:start position:0% +hundreds of volts so this capacitance is +the so-called sort of Miller feedback + + align:start position:0% +the so-called sort of Miller feedback + + + align:start position:0% +the so-called sort of Miller feedback +capacitance this guy right here can have + + align:start position:0% +capacitance this guy right here can have + + + align:start position:0% +capacitance this guy right here can have +a big impact + + align:start position:0% +a big impact + + + align:start position:0% +a big impact +on the switching characteristics here + + align:start position:0% +on the switching characteristics here + + + align:start position:0% +on the switching characteristics here +okay because what happens if I look at + + align:start position:0% +okay because what happens if I look at + + + align:start position:0% +okay because what happens if I look at +sort of the charge I'm sourcing in here + + align:start position:0% +sort of the charge I'm sourcing in here + + + align:start position:0% +sort of the charge I'm sourcing in here +and the voltage vgs I'm getting and this + + align:start position:0% +and the voltage vgs I'm getting and this + + + align:start position:0% +and the voltage vgs I'm getting and this +voltage if this is a end Channel mosfet + + align:start position:0% +voltage if this is a end Channel mosfet + + + align:start position:0% +voltage if this is a end Channel mosfet +it's this voltage that this vgs voltage + + align:start position:0% +it's this voltage that this vgs voltage + + + align:start position:0% +it's this voltage that this vgs voltage +is what's controlling how he switches on + + align:start position:0% +is what's controlling how he switches on + + + align:start position:0% +is what's controlling how he switches on +right if I looked + + align:start position:0% +right if I looked + + + align:start position:0% +right if I looked +at + + align:start position:0% +at + + + align:start position:0% +at +vgs versus + + align:start position:0% +vgs versus + + + align:start position:0% +vgs versus +Q sub Q + + align:start position:0% +Q sub Q + + + align:start position:0% +Q sub Q +subg right the gate charge I'm putting + + align:start position:0% +subg right the gate charge I'm putting + + + align:start position:0% +subg right the gate charge I'm putting +in what would happen well when this + + align:start position:0% +in what would happen well when this + + + align:start position:0% +in what would happen well when this +thing's + + align:start position:0% +thing's + + + align:start position:0% +thing's +off before he turns on I'm going to + + align:start position:0% +off before he turns on I'm going to + + + align:start position:0% +off before he turns on I'm going to +start + + align:start position:0% +start + + + align:start position:0% +start +charging the gate right and this is the + + align:start position:0% +charging the gate right and this is the + + + align:start position:0% +charging the gate right and this is the +capacitance my gate driver is driving + + align:start position:0% +capacitance my gate driver is driving + + + align:start position:0% +capacitance my gate driver is driving +right DQ is + + align:start position:0% +right DQ is + + + align:start position:0% +right DQ is +CDV all right but what happens at some + + align:start position:0% +CDV all right but what happens at some + + + align:start position:0% +CDV all right but what happens at some +point is when vgs gets bigger than the + + align:start position:0% +point is when vgs gets bigger than the + + + align:start position:0% +point is when vgs gets bigger than the +threshold + + align:start position:0% +threshold + + + align:start position:0% +threshold +voltage I'm going to start turning on + + align:start position:0% +voltage I'm going to start turning on + + + align:start position:0% +voltage I'm going to start turning on +this fet which and what what does that + + align:start position:0% +this fet which and what what does that + + + align:start position:0% +this fet which and what what does that +happen this voltage which was up at some + + align:start position:0% +happen this voltage which was up at some + + + align:start position:0% +happen this voltage which was up at some +high voltage this was the output voltage + + align:start position:0% +high voltage this was the output voltage + + + align:start position:0% +high voltage this was the output voltage +maybe that's 200 volts starts to swing + + align:start position:0% +maybe that's 200 volts starts to swing + + + align:start position:0% +maybe that's 200 volts starts to swing +down and when it starts to swing down I + + align:start position:0% +down and when it starts to swing down I + + + align:start position:0% +down and when it starts to swing down I +need to feed charge in from the gate to + + align:start position:0% +need to feed charge in from the gate to + + + align:start position:0% +need to feed charge in from the gate to +to sort of discharge this + + align:start position:0% +to sort of discharge this + + + align:start position:0% +to sort of discharge this +capacitor + + align:start position:0% +capacitor + + + align:start position:0% +capacitor +right and what that means is I'm going + + align:start position:0% +right and what that means is I'm going + + + align:start position:0% +right and what that means is I'm going +to be trying I'm going to be pumping + + align:start position:0% +to be trying I'm going to be pumping + + + align:start position:0% +to be trying I'm going to be pumping +charge in + + align:start position:0% +charge in + + + align:start position:0% +charge in +here but the gate voltage isn't going to + + align:start position:0% +here but the gate voltage isn't going to + + + align:start position:0% +here but the gate voltage isn't going to +be going up appreciatively he's just + + align:start position:0% +be going up appreciatively he's just + + + align:start position:0% +be going up appreciatively he's just +going to sit flat and all the charge I'm + + align:start position:0% +going to sit flat and all the charge I'm + + + align:start position:0% +going to sit flat and all the charge I'm +pumping in here is basically going to + + align:start position:0% +pumping in here is basically going to + + + align:start position:0% +pumping in here is basically going to +drive the drain + + align:start position:0% +drive the drain + + + align:start position:0% +drive the drain +down Okay so this capacitor basically + + align:start position:0% +down Okay so this capacitor basically + + + align:start position:0% +down Okay so this capacitor basically +suddenly makes the equivalent + + align:start position:0% +suddenly makes the equivalent + + + align:start position:0% +suddenly makes the equivalent +capacitance I'm driving at my gate very + + align:start position:0% +capacitance I'm driving at my gate very + + + align:start position:0% +capacitance I'm driving at my gate very +large eventually once I've pumped enough + + align:start position:0% +large eventually once I've pumped enough + + + align:start position:0% +large eventually once I've pumped enough +in this node comes down to close to + + align:start position:0% +in this node comes down to close to + + + align:start position:0% +in this node comes down to close to +ground this voltage ceases changing and + + align:start position:0% +ground this voltage ceases changing and + + + align:start position:0% +ground this voltage ceases changing and +then this goes up like this okay so this + + align:start position:0% +then this goes up like this okay so this + + + align:start position:0% +then this goes up like this okay so this +happens you know somewhere near vth the + + align:start position:0% +happens you know somewhere near vth the + + + align:start position:0% +happens you know somewhere near vth the +threshold voltage of the f + + align:start position:0% +threshold voltage of the f + + + align:start position:0% +threshold voltage of the f +that does that make sense + + align:start position:0% +that does that make sense + + + align:start position:0% +that does that make sense +everybody why am I why am I pointing + + align:start position:0% +everybody why am I why am I pointing + + + align:start position:0% +everybody why am I why am I pointing +this out well two reasons + + align:start position:0% +this out well two reasons + + + align:start position:0% +this out well two reasons +firstly um when I think about the amount + + align:start position:0% +firstly um when I think about the amount + + + align:start position:0% +firstly um when I think about the amount +of charge I need to put in you know + + align:start position:0% +of charge I need to put in you know + + + align:start position:0% +of charge I need to put in you know +maybe this is my this is my threshold + + align:start position:0% +maybe this is my this is my threshold + + + align:start position:0% +maybe this is my this is my threshold +voltage I don't know whatever that is + + align:start position:0% +voltage I don't know whatever that is + + + align:start position:0% +voltage I don't know whatever that is +maybe this is 10 volts and this is 50 + + align:start position:0% +maybe this is 10 volts and this is 50 + + + align:start position:0% +maybe this is 10 volts and this is 50 +nanocs right so what I sort of care + + align:start position:0% +nanocs right so what I sort of care + + + align:start position:0% +nanocs right so what I sort of care +about + + align:start position:0% +about + + + align:start position:0% +about +is I need to Source this total + + align:start position:0% +is I need to Source this total + + + align:start position:0% +is I need to Source this total +charge um to get to 10 volts and if I + + align:start position:0% +charge um to get to 10 volts and if I + + + align:start position:0% +charge um to get to 10 volts and if I +only paid attention to what this + + align:start position:0% +only paid attention to what this + + + align:start position:0% +only paid attention to what this +capacitance was I wouldn't really + + align:start position:0% +capacitance was I wouldn't really + + + align:start position:0% +capacitance was I wouldn't really +calculate the total charge I needed + + align:start position:0% +calculate the total charge I needed + + + align:start position:0% +calculate the total charge I needed +right and how much energy how much do I + + align:start position:0% +right and how much energy how much do I + + + align:start position:0% +right and how much energy how much do I +lose from this Gate Drive power supply + + align:start position:0% +lose from this Gate Drive power supply + + + align:start position:0% +lose from this Gate Drive power supply +well we talked about this when we talked + + align:start position:0% +well we talked about this when we talked + + + align:start position:0% +well we talked about this when we talked +about switch capacitor converters right + + align:start position:0% +about switch capacitor converters right + + + align:start position:0% +about switch capacitor converters right +if I'm supplying you know here's some + + align:start position:0% +if I'm supplying you know here's some + + + align:start position:0% +if I'm supplying you know here's some +value Q + + align:start position:0% +value Q + + + align:start position:0% +value Q +subg total right that Supply is always + + align:start position:0% +subg total right that Supply is always + + + align:start position:0% +subg total right that Supply is always +coming from this you know Gate Drive + + align:start position:0% +coming from this you know Gate Drive + + + align:start position:0% +coming from this you know Gate Drive +power supply voltage 10 volts or + + align:start position:0% +power supply voltage 10 volts or + + + align:start position:0% +power supply voltage 10 volts or +something right so the amount of energy + + align:start position:0% +something right so the amount of energy + + + align:start position:0% +something right so the amount of energy +that comes in to charge up this gate is + + align:start position:0% +that comes in to charge up this gate is + + + align:start position:0% +that comes in to charge up this gate is +going to be equal to + + align:start position:0% +going to be equal to + + + align:start position:0% +going to be equal to +qg times vgs + + align:start position:0% +qg times vgs + + + align:start position:0% +qg times vgs +Max or v v + + align:start position:0% + + + + align:start position:0% + +Supply or this is my Gate Drive power + + align:start position:0% +Supply or this is my Gate Drive power + + + align:start position:0% +Supply or this is my Gate Drive power +supply V + + align:start position:0% +supply V + + + align:start position:0% +supply V +Supply right if I wanted the power + + align:start position:0% +Supply right if I wanted the power + + + align:start position:0% +Supply right if I wanted the power +dissipation that's how much I L you know + + align:start position:0% +dissipation that's how much I L you know + + + align:start position:0% +dissipation that's how much I L you know +some of that energy goes to charging the + + align:start position:0% +some of that energy goes to charging the + + + align:start position:0% +some of that energy goes to charging the +gate some of it goes it gets dissipated + + align:start position:0% +gate some of it goes it gets dissipated + + + align:start position:0% +gate some of it goes it gets dissipated +in the resistors here right we talked + + align:start position:0% +in the resistors here right we talked + + + align:start position:0% +in the resistors here right we talked +about that um when we talked about + + align:start position:0% +about that um when we talked about + + + align:start position:0% +about that um when we talked about +switch capacitor supplies but in the end + + align:start position:0% +switch capacitor supplies but in the end + + + align:start position:0% +switch capacitor supplies but in the end +what happens is I dump all that energy + + align:start position:0% +what happens is I dump all that energy + + + align:start position:0% +what happens is I dump all that energy +anyways when I turn the switch off and + + align:start position:0% +anyways when I turn the switch off and + + + align:start position:0% +anyways when I turn the switch off and +so each cycle I'm going to lose qg time + + align:start position:0% +so each cycle I'm going to lose qg time + + + align:start position:0% +so each cycle I'm going to lose qg time +V Supply or my power is going to be qg V + + align:start position:0% +V Supply or my power is going to be qg V + + + align:start position:0% +V Supply or my power is going to be qg V +Supply times the frequ switching + + align:start position:0% +Supply times the frequ switching + + + align:start position:0% +Supply times the frequ switching +frequency does that make sense + + align:start position:0% + + + + align:start position:0% + +everybody the + + align:start position:0% +everybody the + + + align:start position:0% +everybody the +you know so P + + align:start position:0% +you know so P + + + align:start position:0% +you know so P +gate might be equal to q subg v + + align:start position:0% +gate might be equal to q subg v + + + align:start position:0% +gate might be equal to q subg v +Supply times F switch the number of + + align:start position:0% +Supply times F switch the number of + + + align:start position:0% +Supply times F switch the number of +times I'm turning on and off the switch + + align:start position:0% +times I'm turning on and off the switch + + + align:start position:0% +times I'm turning on and off the switch +per second notice that it has nothing to + + align:start position:0% +per second notice that it has nothing to + + + align:start position:0% +per second notice that it has nothing to +do with the necessarily with the Gate + + align:start position:0% +do with the necessarily with the Gate + + + align:start position:0% +do with the necessarily with the Gate +Drive um internal resistances for the + + align:start position:0% +Drive um internal resistances for the + + + align:start position:0% +Drive um internal resistances for the +same reasons we talked about when we + + align:start position:0% +same reasons we talked about when we + + + align:start position:0% +same reasons we talked about when we +talked about switch capacitor + + align:start position:0% +talked about switch capacitor + + + align:start position:0% +talked about switch capacitor +converters any questions about that + + align:start position:0% + + + + align:start position:0% + +so let's think + + align:start position:0% +so let's think + + + align:start position:0% +so let's think +about so that's one thing I want you to + + align:start position:0% +about so that's one thing I want you to + + + align:start position:0% +about so that's one thing I want you to +pay attention about is you got to really + + align:start position:0% +pay attention about is you got to really + + + align:start position:0% +pay attention about is you got to really +look at these threshold curves to get + + align:start position:0% +look at these threshold curves to get + + + align:start position:0% +look at these threshold curves to get +your total loss okay there's another + + align:start position:0% +your total loss okay there's another + + + align:start position:0% +your total loss okay there's another +thing you might want to think about when + + align:start position:0% +thing you might want to think about when + + + align:start position:0% +thing you might want to think about when +you think about the driver itself and + + align:start position:0% +you think about the driver itself and + + + align:start position:0% +you think about the driver itself and +that's the + + align:start position:0% +that's the + + + align:start position:0% +that's the +following what would this driver this + + align:start position:0% +following what would this driver this + + + align:start position:0% +following what would this driver this +guy look like inside right inside this + + align:start position:0% +guy look like inside right inside this + + + align:start position:0% +guy look like inside right inside this +driver you might model as um you know + + align:start position:0% +driver you might model as um you know + + + align:start position:0% +driver you might model as um you know +one + + align:start position:0% +one + + + align:start position:0% +one +mosfet and another + + align:start position:0% + + + + align:start position:0% + +mosfet and then he's connected to the + + align:start position:0% +mosfet and then he's connected to the + + + align:start position:0% +mosfet and then he's connected to the +gate that he's going to drive right so + + align:start position:0% +gate that he's going to drive right so + + + align:start position:0% +gate that he's going to drive right so +I'm going to either turn on the top you + + align:start position:0% +I'm going to either turn on the top you + + + align:start position:0% +I'm going to either turn on the top you +know so this is my gate driver right I'm + + align:start position:0% +know so this is my gate driver right I'm + + + align:start position:0% +know so this is my gate driver right I'm +going to turn on this is V + + align:start position:0% +going to turn on this is V + + + align:start position:0% +going to turn on this is V +Supply so I'm going to turn on the top + + align:start position:0% +Supply so I'm going to turn on the top + + + align:start position:0% +Supply so I'm going to turn on the top +switch and he's going to charge the gate + + align:start position:0% +switch and he's going to charge the gate + + + align:start position:0% +switch and he's going to charge the gate +and I'm going to turn on the bottom + + align:start position:0% +and I'm going to turn on the bottom + + + align:start position:0% +and I'm going to turn on the bottom +switch and he's going to discharge the + + align:start position:0% +switch and he's going to discharge the + + + align:start position:0% +switch and he's going to discharge the +gate and turn it off does that make + + align:start position:0% +gate and turn it off does that make + + + align:start position:0% +gate and turn it off does that make +sense to everybody + + align:start position:0% + + + + align:start position:0% + +let's think about and by the way + + align:start position:0% +let's think about and by the way + + + align:start position:0% +let's think about and by the way +sometimes let me just think about this + + align:start position:0% +sometimes let me just think about this + + + align:start position:0% +sometimes let me just think about this +I'm going to simplify this as just being + + align:start position:0% +I'm going to simplify this as just being + + + align:start position:0% +I'm going to simplify this as just being +a capacitance a simple linear + + align:start position:0% +a capacitance a simple linear + + + align:start position:0% +a capacitance a simple linear +capacitance but what we know is it's + + align:start position:0% +capacitance but what we know is it's + + + align:start position:0% +capacitance but what we know is it's +anything but a simple linear capacitance + + align:start position:0% +anything but a simple linear capacitance + + + align:start position:0% +anything but a simple linear capacitance +right maybe I'm thinking about this + + align:start position:0% +right maybe I'm thinking about this + + + align:start position:0% +right maybe I'm thinking about this +equivalent capacitance now for + + align:start position:0% +equivalent capacitance now for + + + align:start position:0% +equivalent capacitance now for +Simplicity this cordal + + align:start position:0% +Simplicity this cordal + + + align:start position:0% +Simplicity this cordal +capacitance + + align:start position:0% + + + + align:start position:0% + +um let's think about charging this up + + align:start position:0% +um let's think about charging this up + + + align:start position:0% +um let's think about charging this up +and discharging it okay + + align:start position:0% +and discharging it okay + + + align:start position:0% +and discharging it okay +if I turn on you know one of my + + align:start position:0% +if I turn on you know one of my + + + align:start position:0% +if I turn on you know one of my +Tendencies might be to turn this on as + + align:start position:0% +Tendencies might be to turn this on as + + + align:start position:0% +Tendencies might be to turn this on as +fast as possible but maybe let me just + + align:start position:0% +fast as possible but maybe let me just + + + align:start position:0% +fast as possible but maybe let me just +imagine I have some resistance + + align:start position:0% +imagine I have some resistance + + + align:start position:0% +imagine I have some resistance +here sometimes I have resistance in the + + align:start position:0% +here sometimes I have resistance in the + + + align:start position:0% +here sometimes I have resistance in the +driver sometimes I have resistance in + + align:start position:0% +driver sometimes I have resistance in + + + align:start position:0% +driver sometimes I have resistance in +the gate and sometimes I actually add + + align:start position:0% +the gate and sometimes I actually add + + + align:start position:0% +the gate and sometimes I actually add +external resistor why would I add + + align:start position:0% +external resistor why would I add + + + align:start position:0% +external resistor why would I add +external resistor we talked about Emi + + align:start position:0% +external resistor we talked about Emi + + + align:start position:0% +external resistor we talked about Emi +before when I turn this transistor + + align:start position:0% +before when I turn this transistor + + + align:start position:0% +before when I turn this transistor +on I'm discharging this + + align:start position:0% +on I'm discharging this + + + align:start position:0% +on I'm discharging this +capacitance right so I have some + + align:start position:0% +capacitance right so I have some + + + align:start position:0% +capacitance right so I have some +capacitance here and I'm discharging it + + align:start position:0% +capacitance here and I'm discharging it + + + align:start position:0% +capacitance here and I'm discharging it +into the switch capacitance on my diode + + align:start position:0% +into the switch capacitance on my diode + + + align:start position:0% +into the switch capacitance on my diode +I'm discharging or I'm charging it into + + align:start position:0% +I'm discharging or I'm charging it into + + + align:start position:0% +I'm discharging or I'm charging it into +the switch that causes a huge pulse of + + align:start position:0% +the switch that causes a huge pulse of + + + align:start position:0% +the switch that causes a huge pulse of +current in this + + align:start position:0% +current in this + + + align:start position:0% +current in this +Loop which could cause a lot of noise if + + align:start position:0% +Loop which could cause a lot of noise if + + + align:start position:0% +Loop which could cause a lot of noise if +it rings a lot right and yet the amount + + align:start position:0% +it rings a lot right and yet the amount + + + align:start position:0% +it rings a lot right and yet the amount +I lose at least in the capacitive + + align:start position:0% +I lose at least in the capacitive + + + align:start position:0% +I lose at least in the capacitive +portion doesn't depend on how fast I + + align:start position:0% +portion doesn't depend on how fast I + + + align:start position:0% +portion doesn't depend on how fast I +turn it on right so at some level maybe + + align:start position:0% +turn it on right so at some level maybe + + + align:start position:0% +turn it on right so at some level maybe +I'm motivated to turn on my + + align:start position:0% +I'm motivated to turn on my + + + align:start position:0% +I'm motivated to turn on my +switch somewhat slowly so that I don't + + align:start position:0% +switch somewhat slowly so that I don't + + + align:start position:0% +switch somewhat slowly so that I don't +like discharge this capacitors really + + align:start position:0% +like discharge this capacitors really + + + align:start position:0% +like discharge this capacitors really +really fast and cause a lot of noise so + + align:start position:0% +really fast and cause a lot of noise so + + + align:start position:0% +really fast and cause a lot of noise so +a lot of the time we actually put + + align:start position:0% +a lot of the time we actually put + + + align:start position:0% +a lot of the time we actually put +additional resistance in + + align:start position:0% +additional resistance in + + + align:start position:0% +additional resistance in +here to slow up how fast I turn on the + + align:start position:0% +here to slow up how fast I turn on the + + + align:start position:0% +here to slow up how fast I turn on the +device and some gate drivers will tell + + align:start position:0% +device and some gate drivers will tell + + + align:start position:0% +device and some gate drivers will tell +you what that is sometimes you put your + + align:start position:0% +you what that is sometimes you put your + + + align:start position:0% +you what that is sometimes you put your +in a discrete resistor + + align:start position:0% +in a discrete resistor + + + align:start position:0% +in a discrete resistor +to do + + align:start position:0% +to do + + + align:start position:0% +to do +that what about turning off the + + align:start position:0% +that what about turning off the + + + align:start position:0% +that what about turning off the +device when I turn off the device well + + align:start position:0% +device when I turn off the device well + + + align:start position:0% +device when I turn off the device well +he was on so this already has zero + + align:start position:0% +he was on so this already has zero + + + align:start position:0% +he was on so this already has zero +voltage when I turn him off this device + + align:start position:0% +voltage when I turn him off this device + + + align:start position:0% +voltage when I turn him off this device +isn't going to turn on instantly it's + + align:start position:0% +isn't going to turn on instantly it's + + + align:start position:0% +isn't going to turn on instantly it's +not going to turn on until the inductor + + align:start position:0% +not going to turn on until the inductor + + + align:start position:0% +not going to turn on until the inductor +charges up this capacitance again right + + align:start position:0% +charges up this capacitance again right + + + align:start position:0% +charges up this capacitance again right +so in some sense this capacitance it + + align:start position:0% +so in some sense this capacitance it + + + align:start position:0% +so in some sense this capacitance it +hurt me when I turn it on but now that + + align:start position:0% +hurt me when I turn it on but now that + + + align:start position:0% +hurt me when I turn it on but now that +I'm turning them off he's actually + + align:start position:0% +I'm turning them off he's actually + + + align:start position:0% +I'm turning them off he's actually +acting like a little bit like a snubber + + align:start position:0% +acting like a little bit like a snubber + + + align:start position:0% +acting like a little bit like a snubber +and slowing down the rate of Rise of + + align:start position:0% +and slowing down the rate of Rise of + + + align:start position:0% +and slowing down the rate of Rise of +this thing right + + align:start position:0% +this thing right + + + align:start position:0% +this thing right +but the longer I take to turn him off + + align:start position:0% +but the longer I take to turn him off + + + align:start position:0% +but the longer I take to turn him off +the more overlap I get right like the if + + align:start position:0% +the more overlap I get right like the if + + + align:start position:0% +the more overlap I get right like the if +the longer his current takes to fall The + + align:start position:0% +the longer his current takes to fall The + + + align:start position:0% +the longer his current takes to fall The +More Voltage + + align:start position:0% +More Voltage + + + align:start position:0% +More Voltage +I'm I'm building up across this + + align:start position:0% +I'm I'm building up across this + + + align:start position:0% +I'm I'm building up across this +transistor and dissipating them so it + + align:start position:0% +transistor and dissipating them so it + + + align:start position:0% +transistor and dissipating them so it +doesn't cost me anything to turn them + + align:start position:0% +doesn't cost me anything to turn them + + + align:start position:0% +doesn't cost me anything to turn them +off + + align:start position:0% +off + + + align:start position:0% +off +fast whereas it costs me something to + + align:start position:0% +fast whereas it costs me something to + + + align:start position:0% +fast whereas it costs me something to +turn them on fast in terms of noise so + + align:start position:0% +turn them on fast in terms of noise so + + + align:start position:0% +turn them on fast in terms of noise so +very often we would like to turn on the + + align:start position:0% +very often we would like to turn on the + + + align:start position:0% +very often we would like to turn on the +transistor somewhat slow + + align:start position:0% +transistor somewhat slow + + + align:start position:0% +transistor somewhat slow +slowly and turn them off really fast + + align:start position:0% +slowly and turn them off really fast + + + align:start position:0% +slowly and turn them off really fast +right so you don't + + align:start position:0% +right so you don't + + + align:start position:0% +right so you don't +want this resistor if I if I load it all + + align:start position:0% +want this resistor if I if I load it all + + + align:start position:0% +want this resistor if I if I load it all +into this resistor I don't want this + + align:start position:0% +into this resistor I don't want this + + + align:start position:0% +into this resistor I don't want this +resistor to be the same for turn on and + + align:start position:0% +resistor to be the same for turn on and + + + align:start position:0% +resistor to be the same for turn on and +turn off and what you'll see in a lot of + + align:start position:0% +turn off and what you'll see in a lot of + + + align:start position:0% +turn off and what you'll see in a lot of +drivers is that what they'll do is for + + align:start position:0% +drivers is that what they'll do is for + + + align:start position:0% +drivers is that what they'll do is for +turn on this resistance or equivalently + + align:start position:0% +turn on this resistance or equivalently + + + align:start position:0% +turn on this resistance or equivalently +the positive sourcing capability will be + + align:start position:0% +the positive sourcing capability will be + + + align:start position:0% +the positive sourcing capability will be +you know a bigger resistance and the + + align:start position:0% +you know a bigger resistance and the + + + align:start position:0% +you know a bigger resistance and the +resistance for turning off will be a + + align:start position:0% +resistance for turning off will be a + + + align:start position:0% +resistance for turning off will be a +much smaller resistance so you can turn + + align:start position:0% +much smaller resistance so you can turn + + + align:start position:0% +much smaller resistance so you can turn +the transistor off fast but turn them on + + align:start position:0% +the transistor off fast but turn them on + + + align:start position:0% +the transistor off fast but turn them on +only slightly slow and that'll help + + align:start position:0% +only slightly slow and that'll help + + + align:start position:0% +only slightly slow and that'll help +reduce your + + align:start position:0% +reduce your + + + align:start position:0% +reduce your +noise okay if you don't like what that + + align:start position:0% +noise okay if you don't like what that + + + align:start position:0% +noise okay if you don't like what that +looks + + align:start position:0% +looks + + + align:start position:0% +looks +like right you can add your own resistor + + align:start position:0% +like right you can add your own resistor + + + align:start position:0% +like right you can add your own resistor +that'll slow down the turn on maybe you + + align:start position:0% +that'll slow down the turn on maybe you + + + align:start position:0% +that'll slow down the turn on maybe you +don't want to slow down the turn off as + + align:start position:0% +don't want to slow down the turn off as + + + align:start position:0% +don't want to slow down the turn off as +much so for the turn off maybe what you + + align:start position:0% +much so for the turn off maybe what you + + + align:start position:0% +much so for the turn off maybe what you +do is you put a diode in a smaller + + align:start position:0% +do is you put a diode in a smaller + + + align:start position:0% +do is you put a diode in a smaller +resistor or no resistor here so he + + align:start position:0% +resistor or no resistor here so he + + + align:start position:0% +resistor or no resistor here so he +charges slowly through the yellow + + align:start position:0% +charges slowly through the yellow + + + align:start position:0% +charges slowly through the yellow +resistor and he discharges quickly + + align:start position:0% +resistor and he discharges quickly + + + align:start position:0% +resistor and he discharges quickly +through the green diode + + align:start position:0% +through the green diode + + + align:start position:0% +through the green diode +okay so you can control rate of turn on + + align:start position:0% +okay so you can control rate of turn on + + + align:start position:0% +okay so you can control rate of turn on +and turn off to control that switching + + align:start position:0% +and turn off to control that switching + + + align:start position:0% +and turn off to control that switching +and the noise injection elsewhere in + + align:start position:0% +and the noise injection elsewhere in + + + align:start position:0% +and the noise injection elsewhere in +your circuit and you think about that + + align:start position:0% +your circuit and you think about that + + + align:start position:0% +your circuit and you think about that +when you buy your driver and how you + + align:start position:0% +when you buy your driver and how you + + + align:start position:0% +when you buy your driver and how you +drive you connect your driver to your + + align:start position:0% + + + + align:start position:0% + +switch questions about + + align:start position:0% + + + + align:start position:0% + +that okay so I'm sort of out of time to + + align:start position:0% +that okay so I'm sort of out of time to + + + align:start position:0% +that okay so I'm sort of out of time to +talk about these practical + + align:start position:0% +talk about these practical + + + align:start position:0% +talk about these practical +implementation issues there's like you + + align:start position:0% +implementation issues there's like you + + + align:start position:0% +implementation issues there's like you +could spend a whole course on this but + + align:start position:0% +could spend a whole course on this but + + + align:start position:0% +could spend a whole course on this but +um um at least I hope you get a bit of a + + align:start position:0% +um um at least I hope you get a bit of a + + + align:start position:0% +um um at least I hope you get a bit of a +sense of you know how you might do some + + align:start position:0% +sense of you know how you might do some + + + align:start position:0% +sense of you know how you might do some +of these things in laying out your + + align:start position:0% +of these things in laying out your + + + align:start position:0% +of these things in laying out your +circuit and so at least I've attempted + + align:start position:0% +circuit and so at least I've attempted + + + align:start position:0% +circuit and so at least I've attempted +this term to take you from you know + + align:start position:0% +this term to take you from you know + + + align:start position:0% +this term to take you from you know +what's the basic operation of a + + align:start position:0% +what's the basic operation of a + + + align:start position:0% +what's the basic operation of a +switching circuit how do you design all + + align:start position:0% +switching circuit how do you design all + + + align:start position:0% +switching circuit how do you design all +the components how do you control it how + + align:start position:0% +the components how do you control it how + + + align:start position:0% +the components how do you control it how +do you deal with the + + align:start position:0% +do you deal with the + + + align:start position:0% +do you deal with the +filters how do you lay it out and I'm + + align:start position:0% +filters how do you lay it out and I'm + + + align:start position:0% +filters how do you lay it out and I'm +afraid that's all we have time for I + + align:start position:0% +afraid that's all we have time for I + + + align:start position:0% +afraid that's all we have time for I +wish you the best in finishing your + + align:start position:0% +wish you the best in finishing your + + + align:start position:0% +wish you the best in finishing your +projects and a really nice summer so + + align:start position:0% +projects and a really nice summer so + + + align:start position:0% +projects and a really nice summer so +have a great day \ No newline at end of file diff --git a/Txidu-5VYfU.txt b/Txidu-5VYfU.txt new file mode 100644 index 0000000000000000000000000000000000000000..56ff79efa48864d9bd86ea66a4e406d726d52aef --- /dev/null +++ b/Txidu-5VYfU.txt @@ -0,0 +1,8450 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit mitop courseware at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu um so last time we finished + + align:start position:0% +ocw.mit.edu um so last time we finished + + + align:start position:0% +ocw.mit.edu um so last time we finished +talking about tricular bone and what I + + align:start position:0% +talking about tricular bone and what I + + + align:start position:0% +talking about tricular bone and what I +wanted to talk about this week was + + align:start position:0% +wanted to talk about this week was + + + align:start position:0% +wanted to talk about this week was +tissue engineering scaffolds so the idea + + align:start position:0% +tissue engineering scaffolds so the idea + + + align:start position:0% +tissue engineering scaffolds so the idea +with tissue engineering is you want to + + align:start position:0% +with tissue engineering is you want to + + + align:start position:0% +with tissue engineering is you want to +be able to repair damaged or disease + + align:start position:0% +be able to repair damaged or disease + + + align:start position:0% +be able to repair damaged or disease +tissue and typically that's done by + + align:start position:0% +tissue and typically that's done by + + + align:start position:0% +tissue and typically that's done by +regenerating the tissue in some way so + + align:start position:0% +regenerating the tissue in some way so + + + align:start position:0% +regenerating the tissue in some way so +in your body um many types of cells like + + align:start position:0% +in your body um many types of cells like + + + align:start position:0% +in your body um many types of cells like +maybe not blood cells but most types of + + align:start position:0% +maybe not blood cells but most types of + + + align:start position:0% +maybe not blood cells but most types of +cells for sort of structural tissues are + + align:start position:0% +cells for sort of structural tissues are + + + align:start position:0% +cells for sort of structural tissues are +attached to an extracellular Matrix and + + align:start position:0% +attached to an extracellular Matrix and + + + align:start position:0% +attached to an extracellular Matrix and +this is sort of a schematic of the + + align:start position:0% +this is sort of a schematic of the + + + align:start position:0% +this is sort of a schematic of the +extracellular Matrix here and the + + align:start position:0% +extracellular Matrix here and the + + + align:start position:0% +extracellular Matrix here and the +composition depends on the type of + + align:start position:0% +composition depends on the type of + + + align:start position:0% +composition depends on the type of +tissue that's involved so for example in + + align:start position:0% +tissue that's involved so for example in + + + align:start position:0% +tissue that's involved so for example in +skin it would be um collagen and + + align:start position:0% +skin it would be um collagen and + + + align:start position:0% +skin it would be um collagen and +something called glycoaminoglycans and + + align:start position:0% +something called glycoaminoglycans and + + + align:start position:0% +something called glycoaminoglycans and +elastin in bone it would be collagen and + + align:start position:0% +elastin in bone it would be collagen and + + + align:start position:0% +elastin in bone it would be collagen and +a mineral calcium phosphate mineral + + align:start position:0% +a mineral calcium phosphate mineral + + + align:start position:0% +a mineral calcium phosphate mineral +hydroxy appetite so the composition + + align:start position:0% +hydroxy appetite so the composition + + + align:start position:0% +hydroxy appetite so the composition +varies but the idea with the tissue + + align:start position:0% +varies but the idea with the tissue + + + align:start position:0% +varies but the idea with the tissue +engineering scaffold is that you want to + + align:start position:0% +engineering scaffold is that you want to + + + align:start position:0% +engineering scaffold is that you want to +make a material that essentially + + align:start position:0% +make a material that essentially + + + align:start position:0% +make a material that essentially +substitutes for the extracellular Matrix + + align:start position:0% +substitutes for the extracellular Matrix + + + align:start position:0% +substitutes for the extracellular Matrix +and it does so on a sort of temporary + + align:start position:0% +and it does so on a sort of temporary + + + align:start position:0% +and it does so on a sort of temporary +basis so the idea is you put something + + align:start position:0% +basis so the idea is you put something + + + align:start position:0% +basis so the idea is you put something +in the body the cells attached to that + + align:start position:0% +in the body the cells attached to that + + + align:start position:0% +in the body the cells attached to that +whatever scaffold you put in and the + + align:start position:0% +whatever scaffold you put in and the + + + align:start position:0% +whatever scaffold you put in and the +scaffold has to be made in such a way + + align:start position:0% +scaffold has to be made in such a way + + + align:start position:0% +scaffold has to be made in such a way +that the material that the cells can um + + align:start position:0% +that the material that the cells can um + + + align:start position:0% +that the material that the cells can um +they can migrate through it they can + + align:start position:0% +they can migrate through it they can + + + align:start position:0% +they can migrate through it they can +attach to it they can differentiate they + + align:start position:0% +attach to it they can differentiate they + + + align:start position:0% +attach to it they can differentiate they +can proliferate so the cells can do all + + align:start position:0% +can proliferate so the cells can do all + + + align:start position:0% +can proliferate so the cells can do all +their normal function and the idea is is + + align:start position:0% +their normal function and the idea is is + + + align:start position:0% +their normal function and the idea is is +that as the cells are doing their normal + + align:start position:0% +that as the cells are doing their normal + + + align:start position:0% +that as the cells are doing their normal +function they then secrete the natural + + align:start position:0% +function they then secrete the natural + + + align:start position:0% +function they then secrete the natural +extracellular Matrix and the engineered + + align:start position:0% +extracellular Matrix and the engineered + + + align:start position:0% +extracellular Matrix and the engineered +thing that you put in is resorbed so + + align:start position:0% +thing that you put in is resorbed so + + + align:start position:0% +thing that you put in is resorbed so +there has to be a balance between the + + align:start position:0% +there has to be a balance between the + + + align:start position:0% +there has to be a balance between the +rate at which the scaffold you've made + + align:start position:0% +rate at which the scaffold you've made + + + align:start position:0% +rate at which the scaffold you've made +resorbs and the rate at which the cells + + align:start position:0% +resorbs and the rate at which the cells + + + align:start position:0% +resorbs and the rate at which the cells +are depositing the new native + + align:start position:0% +are depositing the new native + + + align:start position:0% +are depositing the new native +extracellular Matrix so that's one of + + align:start position:0% +extracellular Matrix so that's one of + + + align:start position:0% +extracellular Matrix so that's one of +the the key things about this so so this + + align:start position:0% +the the key things about this so so this + + + align:start position:0% +the the key things about this so so this +is just an example of um sort of a + + align:start position:0% +is just an example of um sort of a + + + align:start position:0% +is just an example of um sort of a +schematic of an extracellular Matrix in + + align:start position:0% +schematic of an extracellular Matrix in + + + align:start position:0% +schematic of an extracellular Matrix in +this case here uh there's collagen + + align:start position:0% +this case here uh there's collagen + + + align:start position:0% +this case here uh there's collagen +fibers so these guys here are collagen + + align:start position:0% +fibers so these guys here are collagen + + + align:start position:0% +fibers so these guys here are collagen +fibers and these kind of hairy looking + + align:start position:0% +fibers and these kind of hairy looking + + + align:start position:0% +fibers and these kind of hairy looking +things are + + align:start position:0% +things are + + + align:start position:0% +things are +proteoglycans so they have a core of + + align:start position:0% +proteoglycans so they have a core of + + + align:start position:0% +proteoglycans so they have a core of +protein with sugars kind of hanging off + + align:start position:0% +protein with sugars kind of hanging off + + + align:start position:0% +protein with sugars kind of hanging off +of them and there's different kinds of + + align:start position:0% +of them and there's different kinds of + + + align:start position:0% +of them and there's different kinds of +of uh gags they're called that hang off + + align:start position:0% +of uh gags they're called that hang off + + + align:start position:0% +of uh gags they're called that hang off +of them uh so one's krtin sulfate the Cs + + align:start position:0% +of them uh so one's krtin sulfate the Cs + + + align:start position:0% +of them uh so one's krtin sulfate the Cs +here stands for condroitin sulfate uh + + align:start position:0% +here stands for condroitin sulfate uh + + + align:start position:0% +here stands for condroitin sulfate uh +there's one called there's one called um + + align:start position:0% +there's one called there's one called um + + + align:start position:0% +there's one called there's one called um +dermatin sulfate and there's one called + + align:start position:0% +dermatin sulfate and there's one called + + + align:start position:0% +dermatin sulfate and there's one called +Heparin sulfate so there there's + + align:start position:0% +Heparin sulfate so there there's + + + align:start position:0% +Heparin sulfate so there there's +different of these + + align:start position:0% +different of these + + + align:start position:0% +different of these +glycosaminoglycans so let me write down + + align:start position:0% +glycosaminoglycans so let me write down + + + align:start position:0% +glycosaminoglycans so let me write down +some of this and then we'll we'll kind + + align:start position:0% +some of this and then we'll we'll kind + + + align:start position:0% +some of this and then we'll we'll kind +of get into this so what I wanted to do + + align:start position:0% +of get into this so what I wanted to do + + + align:start position:0% +of get into this so what I wanted to do +today will show you uh some examples of + + align:start position:0% +today will show you uh some examples of + + + align:start position:0% +today will show you uh some examples of +tissue engineering scaffolds show you uh + + align:start position:0% +tissue engineering scaffolds show you uh + + + align:start position:0% +tissue engineering scaffolds show you uh +some of the sort of design requirements + + align:start position:0% +some of the sort of design requirements + + + align:start position:0% +some of the sort of design requirements +so you have to have obviously a material + + align:start position:0% +so you have to have obviously a material + + + align:start position:0% +so you have to have obviously a material +that's porous so the cells can get in + + align:start position:0% +that's porous so the cells can get in + + + align:start position:0% +that's porous so the cells can get in +there and that's where the cellular + + align:start position:0% +there and that's where the cellular + + + align:start position:0% +there and that's where the cellular +solids comes in um so we'll talk about + + align:start position:0% +solids comes in um so we'll talk about + + + align:start position:0% +solids comes in um so we'll talk about +some scaffolds some of the sort of + + align:start position:0% +some scaffolds some of the sort of + + + align:start position:0% +some scaffolds some of the sort of +design requirements for them and also uh + + align:start position:0% +design requirements for them and also uh + + + align:start position:0% +design requirements for them and also uh +we'll talk a little bit about processing + + align:start position:0% +we'll talk a little bit about processing + + + align:start position:0% +we'll talk a little bit about processing +of the scaffolds and mechanical + + align:start position:0% +of the scaffolds and mechanical + + + align:start position:0% +of the scaffolds and mechanical +properties of the scaffolds so I'm + + align:start position:0% +properties of the scaffolds so I'm + + + align:start position:0% +properties of the scaffolds so I'm +hoping I can finish most of that today + + align:start position:0% +hoping I can finish most of that today + + + align:start position:0% +hoping I can finish most of that today +and then next time I have a little case + + align:start position:0% +and then next time I have a little case + + + align:start position:0% +and then next time I have a little case +study on osteochondral scaffolds so + + align:start position:0% +study on osteochondral scaffolds so + + + align:start position:0% +study on osteochondral scaffolds so +Osteo means bone and the condal means + + align:start position:0% +Osteo means bone and the condal means + + + align:start position:0% +Osteo means bone and the condal means +cartilage so this was sort of a + + align:start position:0% +cartilage so this was sort of a + + + align:start position:0% +cartilage so this was sort of a +two-layer scaffold that we developed in + + align:start position:0% +two-layer scaffold that we developed in + + + align:start position:0% +two-layer scaffold that we developed in +collaboration with some other people in + + align:start position:0% +collaboration with some other people in + + + align:start position:0% +collaboration with some other people in +MIT and some people at Cambridge + + align:start position:0% +MIT and some people at Cambridge + + + align:start position:0% +MIT and some people at Cambridge +University um and it went from sort of a + + align:start position:0% +University um and it went from sort of a + + + align:start position:0% +University um and it went from sort of a +research thing to a startup thing and + + align:start position:0% +research thing to a startup thing and + + + align:start position:0% +research thing to a startup thing and +being used clinically so I was going to + + align:start position:0% +being used clinically so I was going to + + + align:start position:0% +being used clinically so I was going to +talk about that uh Wednesday okay so + + align:start position:0% +talk about that uh Wednesday okay so + + + align:start position:0% +talk about that uh Wednesday okay so +oops let me just get started + + align:start position:0% + + + + align:start position:0% + +here so the goal of tissue engineering + + align:start position:0% + + + + align:start position:0% + +is to regenerate diseased or damaged + + align:start position:0% + + + + align:start position:0% + +tissues and in the body the cells + + align:start position:0% +tissues and in the body the cells + + + align:start position:0% +tissues and in the body the cells +attached to the extracellular Matrix + + align:start position:0% + + + + align:start position:0% + +and that's sometimes called the + + align:start position:0% + + + + align:start position:0% + +ECM so sometimes the scaffolds are + + align:start position:0% +ECM so sometimes the scaffolds are + + + align:start position:0% +ECM so sometimes the scaffolds are +called scaffolds and sometimes they're + + align:start position:0% +called scaffolds and sometimes they're + + + align:start position:0% +called scaffolds and sometimes they're +called Matrix because the extracellular + + align:start position:0% +called Matrix because the extracellular + + + align:start position:0% +called Matrix because the extracellular +Matrix is called uh + + align:start position:0% + + + + align:start position:0% + +Matrix so then the composition of the + + align:start position:0% +Matrix so then the composition of the + + + align:start position:0% +Matrix so then the composition of the +ECM + + align:start position:0% + + + + align:start position:0% + +depends on the + + align:start position:0% + + + + align:start position:0% + +tissue but it usually involves some sort + + align:start position:0% +tissue but it usually involves some sort + + + align:start position:0% +tissue but it usually involves some sort +of structural protein so something like + + align:start position:0% +of structural protein so something like + + + align:start position:0% +of structural protein so something like +collagen or elastin + + align:start position:0% + + + + align:start position:0% + +it also typically involves some sort of + + align:start position:0% +it also typically involves some sort of + + + align:start position:0% +it also typically involves some sort of +adhesive + + align:start position:0% + + + + align:start position:0% + +proteins so something like fibron + + align:start position:0% +proteins so something like fibron + + + align:start position:0% +proteins so something like fibron +nectin or + + align:start position:0% + + + + align:start position:0% + +laminin and it involves these + + align:start position:0% +laminin and it involves these + + + align:start position:0% +laminin and it involves these +proteoglycans which are the core of + + align:start position:0% +proteoglycans which are the core of + + + align:start position:0% +proteoglycans which are the core of +protein with a sugar hanging off them + + align:start position:0% +protein with a sugar hanging off them + + + align:start position:0% +protein with a sugar hanging off them +oops + + align:start position:0% + + + + align:start position:0% + +and the sugars are typically um + + align:start position:0% + + + + align:start position:0% + +glycosaminoglycans and for short people + + align:start position:0% +glycosaminoglycans and for short people + + + align:start position:0% +glycosaminoglycans and for short people +call them Gags Just because it's easier + + align:start position:0% +call them Gags Just because it's easier + + + align:start position:0% +call them Gags Just because it's easier +to + + align:start position:0% + + + + align:start position:0% + +say so some examples of the gags are kro + + align:start position:0% +say so some examples of the gags are kro + + + align:start position:0% +say so some examples of the gags are kro +and + + align:start position:0% + + + + align:start position:0% + +sulfate and we're going to talk more + + align:start position:0% +sulfate and we're going to talk more + + + align:start position:0% +sulfate and we're going to talk more +about that a little later because that's + + align:start position:0% +about that a little later because that's + + + align:start position:0% +about that a little later because that's +that's one that we've used um in making + + align:start position:0% +that's one that we've used um in making + + + align:start position:0% +that's one that we've used um in making +collagen based scaffolds with uh Yanni + + align:start position:0% +collagen based scaffolds with uh Yanni + + + align:start position:0% +collagen based scaffolds with uh Yanni +and ass + + align:start position:0% + + + + align:start position:0% + +so for example if you look at the + + align:start position:0% +so for example if you look at the + + + align:start position:0% +so for example if you look at the +composition of extracellular Matrix and + + align:start position:0% +composition of extracellular Matrix and + + + align:start position:0% +composition of extracellular Matrix and +something like cartilage it has a + + align:start position:0% +something like cartilage it has a + + + align:start position:0% +something like cartilage it has a +collagen component and um and a h + + align:start position:0% +collagen component and um and a h + + + align:start position:0% +collagen component and um and a h +hyaluronic acid component and some gags + + align:start position:0% + + + + align:start position:0% + +and this hialuronic acid is a + + align:start position:0% + + + + align:start position:0% + +proteoglycan if you look at + + align:start position:0% +proteoglycan if you look at + + + align:start position:0% +proteoglycan if you look at +bone extracellular matrix in bone is + + align:start position:0% +bone extracellular matrix in bone is + + + align:start position:0% +bone extracellular matrix in bone is +made up mostly of collagen and hydroxy + + align:start position:0% +made up mostly of collagen and hydroxy + + + align:start position:0% +made up mostly of collagen and hydroxy +appetite + + align:start position:0% + + + + align:start position:0% + +and if you look at + + align:start position:0% +and if you look at + + + align:start position:0% +and if you look at +skin skin is made up of + + align:start position:0% +skin skin is made up of + + + align:start position:0% +skin skin is made up of +collagen elastin and + + align:start position:0% + + + + align:start position:0% + +proteoglycans and the idea is that the + + align:start position:0% +proteoglycans and the idea is that the + + + align:start position:0% +proteoglycans and the idea is that the +cells have to be attached to this + + align:start position:0% +cells have to be attached to this + + + align:start position:0% +cells have to be attached to this +extracellular Matrix in order to + + align:start position:0% +extracellular Matrix in order to + + + align:start position:0% +extracellular Matrix in order to +function or they have to be attached to + + align:start position:0% +function or they have to be attached to + + + align:start position:0% +function or they have to be attached to +this or to other cells in most cases is + + align:start position:0% + + + + align:start position:0% + +so next week I'm going to talk a bit + + align:start position:0% +so next week I'm going to talk a bit + + + align:start position:0% +so next week I'm going to talk a bit +about cell mechanics and uh we have some + + align:start position:0% +about cell mechanics and uh we have some + + + align:start position:0% +about cell mechanics and uh we have some +video where we watch a cell um deforming + + align:start position:0% +video where we watch a cell um deforming + + + align:start position:0% +video where we watch a cell um deforming +a scaffold and I don't have videos to + + align:start position:0% +a scaffold and I don't have videos to + + + align:start position:0% +a scaffold and I don't have videos to +show you but I had a student who took + + align:start position:0% +show you but I had a student who took + + + align:start position:0% +show you but I had a student who took +videos of cells migrating along the + + align:start position:0% +videos of cells migrating along the + + + align:start position:0% +videos of cells migrating along the +scaffolds um and you can see how we'll + + align:start position:0% +scaffolds um and you can see how we'll + + + align:start position:0% +scaffolds um and you can see how we'll +look at how the stiffness of the + + align:start position:0% +look at how the stiffness of the + + + align:start position:0% +look at how the stiffness of the +scaffold affects how the cells m along + + align:start position:0% +scaffold affects how the cells m along + + + align:start position:0% +scaffold affects how the cells m along +the + + align:start position:0% + + + + align:start position:0% + +scaffold so that's kind of the the + + align:start position:0% +scaffold so that's kind of the the + + + align:start position:0% +scaffold so that's kind of the the +native ECM in the body and the idea with + + align:start position:0% +native ECM in the body and the idea with + + + align:start position:0% +native ECM in the body and the idea with +tissue engineering is that you want to + + align:start position:0% +tissue engineering is that you want to + + + align:start position:0% +tissue engineering is that you want to +make a scaffold that's porous that mimic + + align:start position:0% +make a scaffold that's porous that mimic + + + align:start position:0% +make a scaffold that's porous that mimic +The extracellular Matrix in the body so + + align:start position:0% +The extracellular Matrix in the body so + + + align:start position:0% +The extracellular Matrix in the body so +that say there's some tissue that's + + align:start position:0% +that say there's some tissue that's + + + align:start position:0% +that say there's some tissue that's +damaged say there's damaged cartilage + + align:start position:0% +damaged say there's damaged cartilage + + + align:start position:0% +damaged say there's damaged cartilage +you want to provide sort of an + + align:start position:0% +you want to provide sort of an + + + align:start position:0% +you want to provide sort of an +extracellular Matrix that's a sort of + + align:start position:0% +extracellular Matrix that's a sort of + + + align:start position:0% +extracellular Matrix that's a sort of +synthetic thing that's going to provide + + align:start position:0% +synthetic thing that's going to provide + + + align:start position:0% +synthetic thing that's going to provide +the same function as the the ECM in the + + align:start position:0% +the same function as the the ECM in the + + + align:start position:0% +the same function as the the ECM in the +native + + align:start position:0% + + + + align:start position:0% + +tissue so people have been working on + + align:start position:0% +tissue so people have been working on + + + align:start position:0% +tissue so people have been working on +scaffolds for regenerating all sorts of + + align:start position:0% +scaffolds for regenerating all sorts of + + + align:start position:0% +scaffolds for regenerating all sorts of +different tissues and probably the most + + align:start position:0% +different tissues and probably the most + + + align:start position:0% +different tissues and probably the most +successful one has been used to + + align:start position:0% +successful one has been used to + + + align:start position:0% +successful one has been used to +regenerate skin and there's been + + align:start position:0% +regenerate skin and there's been + + + align:start position:0% +regenerate skin and there's been +scaffolds available for regenerating + + align:start position:0% +scaffolds available for regenerating + + + align:start position:0% +scaffolds available for regenerating +skin for probably almost 20 years now + + align:start position:0% +skin for probably almost 20 years now + + + align:start position:0% +skin for probably almost 20 years now +and one of the first ones was developed + + align:start position:0% +and one of the first ones was developed + + + align:start position:0% +and one of the first ones was developed +by professor yanos in mechanical + + align:start position:0% +by professor yanos in mechanical + + + align:start position:0% +by professor yanos in mechanical +engineering here at MIT and it's + + align:start position:0% +engineering here at MIT and it's + + + align:start position:0% +engineering here at MIT and it's +actually still sold by a company called + + align:start position:0% +actually still sold by a company called + + + align:start position:0% +actually still sold by a company called +Integra + + align:start position:0% + + + + align:start position:0% + +but there's research to develop + + align:start position:0% +but there's research to develop + + + align:start position:0% +but there's research to develop +scaffolds for lots of different tissues + + align:start position:0% +scaffolds for lots of different tissues + + + align:start position:0% +scaffolds for lots of different tissues +um Orthopedic tissues things like bone + + align:start position:0% +um Orthopedic tissues things like bone + + + align:start position:0% +um Orthopedic tissues things like bone +and cartilage cardiovascular tissues uh + + align:start position:0% +and cartilage cardiovascular tissues uh + + + align:start position:0% +and cartilage cardiovascular tissues uh +nerve like Professor Yos works on + + align:start position:0% +nerve like Professor Yos works on + + + align:start position:0% +nerve like Professor Yos works on +peripheral nerve these days people have + + align:start position:0% +peripheral nerve these days people have + + + align:start position:0% +peripheral nerve these days people have +looked at trying to make scaffolds for + + align:start position:0% +looked at trying to make scaffolds for + + + align:start position:0% +looked at trying to make scaffolds for +gastrointestinal tissues so all sorts of + + align:start position:0% +gastrointestinal tissues so all sorts of + + + align:start position:0% +gastrointestinal tissues so all sorts of +different tissues and MIT there's quite + + align:start position:0% +different tissues and MIT there's quite + + + align:start position:0% +different tissues and MIT there's quite +a lot of interest in this there's a lot + + align:start position:0% +a lot of interest in this there's a lot + + + align:start position:0% +a lot of interest in this there's a lot +of people work on it so Bob Langer works + + align:start position:0% +of people work on it so Bob Langer works + + + align:start position:0% +of people work on it so Bob Langer works +on it Linda Griffith Sita baa there's + + align:start position:0% +on it Linda Griffith Sita baa there's + + + align:start position:0% +on it Linda Griffith Sita baa there's +there's really quite a number of people + + align:start position:0% +there's really quite a number of people + + + align:start position:0% +there's really quite a number of people +at MIT who work on it + + align:start position:0% + + + + align:start position:0% + +so those are just some of the people at + + align:start position:0% +so those are just some of the people at + + + align:start position:0% +so those are just some of the people at +MIT so the idea is is in the body the + + align:start position:0% +MIT so the idea is is in the body the + + + align:start position:0% +MIT so the idea is is in the body the +cells are constantly resorbing The + + align:start position:0% +cells are constantly resorbing The + + + align:start position:0% +cells are constantly resorbing The +extracellular Matrix and depositing more + + align:start position:0% +extracellular Matrix and depositing more + + + align:start position:0% +extracellular Matrix and depositing more +so if you think about bone B for example + + align:start position:0% +so if you think about bone B for example + + + align:start position:0% +so if you think about bone B for example +remember we said bone grows in response + + align:start position:0% +remember we said bone grows in response + + + align:start position:0% +remember we said bone grows in response +to load even in healthy bone the bone is + + align:start position:0% +to load even in healthy bone the bone is + + + align:start position:0% +to load even in healthy bone the bone is +constantly being resorbed and deposited + + align:start position:0% +constantly being resorbed and deposited + + + align:start position:0% +constantly being resorbed and deposited +and in normal bone the rate of + + align:start position:0% +and in normal bone the rate of + + + align:start position:0% +and in normal bone the rate of +resorption and the rate of deposition is + + align:start position:0% +resorption and the rate of deposition is + + + align:start position:0% +resorption and the rate of deposition is +roughly the same when people get + + align:start position:0% +roughly the same when people get + + + align:start position:0% +roughly the same when people get +osteoporosis the thing that happens is + + align:start position:0% +osteoporosis the thing that happens is + + + align:start position:0% +osteoporosis the thing that happens is +that that balance gets out of whack and + + align:start position:0% +that that balance gets out of whack and + + + align:start position:0% +that that balance gets out of whack and +so it's not being deposited at the same + + align:start position:0% +so it's not being deposited at the same + + + align:start position:0% +so it's not being deposited at the same +rate it's being resorbed + + align:start position:0% + + + + align:start position:0% + +and the idea with the tissue engineering + + align:start position:0% +and the idea with the tissue engineering + + + align:start position:0% +and the idea with the tissue engineering +scaffolds is that that they degrade over + + align:start position:0% +scaffolds is that that they degrade over + + + align:start position:0% +scaffolds is that that they degrade over +time and that the cells that were + + align:start position:0% +time and that the cells that were + + + align:start position:0% +time and that the cells that were +attached to them uh are forming their + + align:start position:0% +attached to them uh are forming their + + + align:start position:0% +attached to them uh are forming their +own extracellular Matrix so there's kind + + align:start position:0% +own extracellular Matrix so there's kind + + + align:start position:0% +own extracellular Matrix so there's kind +of a balancing act between the cells + + align:start position:0% +of a balancing act between the cells + + + align:start position:0% +of a balancing act between the cells +depositing the native ECM and the tissue + + align:start position:0% +depositing the native ECM and the tissue + + + align:start position:0% +depositing the native ECM and the tissue +engineering scaffold that was provided + + align:start position:0% +engineering scaffold that was provided + + + align:start position:0% +engineering scaffold that was provided +Say by the clinician being + + align:start position:0% +Say by the clinician being + + + align:start position:0% +Say by the clinician being +resorbed so the so the scaffolds are + + align:start position:0% +resorbed so the so the scaffolds are + + + align:start position:0% +resorbed so the so the scaffolds are +actually designed to degrade and + + align:start position:0% +actually designed to degrade and + + + align:start position:0% +actually designed to degrade and +controlling that degradation rate is one + + align:start position:0% +controlling that degradation rate is one + + + align:start position:0% +controlling that degradation rate is one +of the design parameters of the + + align:start position:0% +of the design parameters of the + + + align:start position:0% +of the design parameters of the +scaffolds + + align:start position:0% + + + + align:start position:0% + +okay so that's kind of the the overall + + align:start position:0% +okay so that's kind of the the overall + + + align:start position:0% +okay so that's kind of the the overall +kind of big picture and what I wanted to + + align:start position:0% +kind of big picture and what I wanted to + + + align:start position:0% +kind of big picture and what I wanted to +talk about next was some design + + align:start position:0% +talk about next was some design + + + align:start position:0% +talk about next was some design +requirements for the scaffolds so if you + + align:start position:0% +requirements for the scaffolds so if you + + + align:start position:0% +requirements for the scaffolds so if you +think about it there's there's different + + align:start position:0% +think about it there's there's different + + + align:start position:0% +think about it there's there's different +sort of um ways you can think about what + + align:start position:0% +sort of um ways you can think about what + + + align:start position:0% +sort of um ways you can think about what +the requirements are so you have to make + + align:start position:0% +the requirements are so you have to make + + + align:start position:0% +the requirements are so you have to make +the scaffold out of Some solid and + + align:start position:0% +the scaffold out of Some solid and + + + align:start position:0% +the scaffold out of Some solid and +there's some requirements for the solid + + align:start position:0% +there's some requirements for the solid + + + align:start position:0% +there's some requirements for the solid +so obviously you want a solid that's + + align:start position:0% +so obviously you want a solid that's + + + align:start position:0% +so obviously you want a solid that's +biocompatible that's one kind of main + + align:start position:0% +biocompatible that's one kind of main + + + align:start position:0% +biocompatible that's one kind of main +requirement another requirement is that + + align:start position:0% +requirement another requirement is that + + + align:start position:0% +requirement another requirement is that +not only the solid has to be + + align:start position:0% +not only the solid has to be + + + align:start position:0% +not only the solid has to be +biocompatible but when the solid + + align:start position:0% +biocompatible but when the solid + + + align:start position:0% +biocompatible but when the solid +decomposes if it decomposes into other + + align:start position:0% +decomposes if it decomposes into other + + + align:start position:0% +decomposes if it decomposes into other +components they have to be biocompatible + + align:start position:0% +components they have to be biocompatible + + + align:start position:0% +components they have to be biocompatible +too so you don't want the the solid to + + align:start position:0% +too so you don't want the the solid to + + + align:start position:0% +too so you don't want the the solid to +degrade during this resorption process + + align:start position:0% +degrade during this resorption process + + + align:start position:0% +degrade during this resorption process +into toxic components that would be a + + align:start position:0% +into toxic components that would be a + + + align:start position:0% +into toxic components that would be a +bad idea and then the other thing is the + + align:start position:0% +bad idea and then the other thing is the + + + align:start position:0% +bad idea and then the other thing is the +solid itself has to promote cell + + align:start position:0% +solid itself has to promote cell + + + align:start position:0% +solid itself has to promote cell +attachment and cell proliferation and uh + + align:start position:0% +attachment and cell proliferation and uh + + + align:start position:0% +attachment and cell proliferation and uh +cell migration all these kinds of things + + align:start position:0% +cell migration all these kinds of things + + + align:start position:0% +cell migration all these kinds of things +so we're going to talk about some + + align:start position:0% +so we're going to talk about some + + + align:start position:0% +so we're going to talk about some +different materials for the scaffolds + + align:start position:0% +different materials for the scaffolds + + + align:start position:0% +different materials for the scaffolds +and some of them are are sort of native + + align:start position:0% +and some of them are are sort of native + + + align:start position:0% +and some of them are are sort of native +proteins so some of them are things like + + align:start position:0% +proteins so some of them are things like + + + align:start position:0% +proteins so some of them are things like +collagen collagen already has binding + + align:start position:0% +collagen collagen already has binding + + + align:start position:0% +collagen collagen already has binding +sites for cells to attach to it + + align:start position:0% +sites for cells to attach to it + + + align:start position:0% +sites for cells to attach to it +obviously it's one of the proteins in in + + align:start position:0% +obviously it's one of the proteins in in + + + align:start position:0% +obviously it's one of the proteins in in +the native ECM there's also a number of + + align:start position:0% +the native ECM there's also a number of + + + align:start position:0% +the native ECM there's also a number of +synthetic polymers you can use and with + + align:start position:0% +synthetic polymers you can use and with + + + align:start position:0% +synthetic polymers you can use and with +the synthetic polymers they don't have + + align:start position:0% +the synthetic polymers they don't have + + + align:start position:0% +the synthetic polymers they don't have +natural binding sites for the cells and + + align:start position:0% +natural binding sites for the cells and + + + align:start position:0% +natural binding sites for the cells and +so you have to coat them with something + + align:start position:0% +so you have to coat them with something + + + align:start position:0% +so you have to coat them with something +else so you have to coat them with say + + align:start position:0% +else so you have to coat them with say + + + align:start position:0% +else so you have to coat them with say +adhesive proteins so that the cells will + + align:start position:0% +adhesive proteins so that the cells will + + + align:start position:0% +adhesive proteins so that the cells will +attach to them so we're going to talk + + align:start position:0% +attach to them so we're going to talk + + + align:start position:0% +attach to them so we're going to talk +about the um requirements for the solid + + align:start position:0% +about the um requirements for the solid + + + align:start position:0% +about the um requirements for the solid +then you make the solid into some sort + + align:start position:0% +then you make the solid into some sort + + + align:start position:0% +then you make the solid into some sort +of porous foamy thing I think I have + + align:start position:0% +of porous foamy thing I think I have + + + align:start position:0% +of porous foamy thing I think I have +some slides here here's an example of a + + align:start position:0% +some slides here here's an example of a + + + align:start position:0% +some slides here here's an example of a +collagen gag scaffold and this is one of + + align:start position:0% +collagen gag scaffold and this is one of + + + align:start position:0% +collagen gag scaffold and this is one of +the ones that um is made in yasis lab + + align:start position:0% +the ones that um is made in yasis lab + + + align:start position:0% +the ones that um is made in yasis lab +and you can see it looks a lot like a + + align:start position:0% +and you can see it looks a lot like a + + + align:start position:0% +and you can see it looks a lot like a +foam it's very very porous and there's + + align:start position:0% +foam it's very very porous and there's + + + align:start position:0% +foam it's very very porous and there's +some requirements for the sort of + + align:start position:0% +some requirements for the sort of + + + align:start position:0% +some requirements for the sort of +cellular structure the foamy structure + + align:start position:0% +cellular structure the foamy structure + + + align:start position:0% +cellular structure the foamy structure +of the scaffold as well so typically you + + align:start position:0% +of the scaffold as well so typically you + + + align:start position:0% +of the scaffold as well so typically you +want interconnected pores so it's easy + + align:start position:0% +want interconnected pores so it's easy + + + align:start position:0% +want interconnected pores so it's easy +for the cells to migrate in you want a + + align:start position:0% +for the cells to migrate in you want a + + + align:start position:0% +for the cells to migrate in you want a +typically you want pores to be within a + + align:start position:0% +typically you want pores to be within a + + + align:start position:0% +typically you want pores to be within a +certain range it turns out if the pores + + align:start position:0% +certain range it turns out if the pores + + + align:start position:0% +certain range it turns out if the pores +are too small it makes difficult for the + + align:start position:0% +are too small it makes difficult for the + + + align:start position:0% +are too small it makes difficult for the +cells to get in I mean sometimes they + + align:start position:0% +cells to get in I mean sometimes they + + + align:start position:0% +cells to get in I mean sometimes they +can by eating away at the material but + + align:start position:0% +can by eating away at the material but + + + align:start position:0% +can by eating away at the material but +um typically the pores want you want + + align:start position:0% +um typically the pores want you want + + + align:start position:0% +um typically the pores want you want +them to be bigger than a certain size + + align:start position:0% +them to be bigger than a certain size + + + align:start position:0% +them to be bigger than a certain size +you Al also want them to be smaller than + + align:start position:0% +you Al also want them to be smaller than + + + align:start position:0% +you Al also want them to be smaller than +a certain size because how much specific + + align:start position:0% +a certain size because how much specific + + + align:start position:0% +a certain size because how much specific +surface area how much surface area per + + align:start position:0% +surface area how much surface area per + + + align:start position:0% +surface area how much surface area per +unit volume you've got depends on the + + align:start position:0% +unit volume you've got depends on the + + + align:start position:0% +unit volume you've got depends on the +pore size the smaller the pores the more + + align:start position:0% +pore size the smaller the pores the more + + + align:start position:0% +pore size the smaller the pores the more +surface area per unit volume you have + + align:start position:0% +surface area per unit volume you have + + + align:start position:0% +surface area per unit volume you have +and then the number of binding sites you + + align:start position:0% +and then the number of binding sites you + + + align:start position:0% +and then the number of binding sites you +have for cells to attach to it depends + + align:start position:0% +have for cells to attach to it depends + + + align:start position:0% +have for cells to attach to it depends +on that specific surface area I'm going + + align:start position:0% +on that specific surface area I'm going + + + align:start position:0% +on that specific surface area I'm going +to write all this down so um I'll do + + align:start position:0% +to write all this down so um I'll do + + + align:start position:0% +to write all this down so um I'll do +that so so there's requirements for sort + + align:start position:0% +that so so there's requirements for sort + + + align:start position:0% +that so so there's requirements for sort +of the pore structure uh and then + + align:start position:0% +of the pore structure uh and then + + + align:start position:0% +of the pore structure uh and then +there's also some requirements for the + + align:start position:0% +there's also some requirements for the + + + align:start position:0% +there's also some requirements for the +whole scaffold itself so for instance + + align:start position:0% +whole scaffold itself so for instance + + + align:start position:0% +whole scaffold itself so for instance +it's got to have some minimum mechanical + + align:start position:0% +it's got to have some minimum mechanical + + + align:start position:0% +it's got to have some minimum mechanical +Integrity so there's sort of some + + align:start position:0% +Integrity so there's sort of some + + + align:start position:0% +Integrity so there's sort of some +requirements for that so there's + + align:start position:0% +requirements for that so there's + + + align:start position:0% +requirements for that so there's +requirements for the solid there's + + align:start position:0% +requirements for the solid there's + + + align:start position:0% +requirements for the solid there's +requirements for the sort of cells + + align:start position:0% +requirements for the sort of cells + + + align:start position:0% +requirements for the sort of cells +cellular structure the porous structure + + align:start position:0% +cellular structure the porous structure + + + align:start position:0% +cellular structure the porous structure +and there requirements for the overall + + align:start position:0% +and there requirements for the overall + + + align:start position:0% +and there requirements for the overall +scaffold so let me um write some of + + align:start position:0% +scaffold so let me um write some of + + + align:start position:0% +scaffold so let me um write some of +these things down + + align:start position:0% + + + + align:start position:0% + +so there's some requirements for the + + align:start position:0% +so there's some requirements for the + + + align:start position:0% +so there's some requirements for the +solid so it must be + + align:start position:0% + + + + align:start position:0% + +biocompatible it must also promote cell + + align:start position:0% +biocompatible it must also promote cell + + + align:start position:0% +biocompatible it must also promote cell +attachment and proliferation in the cell + + align:start position:0% +attachment and proliferation in the cell + + + align:start position:0% +attachment and proliferation in the cell +functions + + align:start position:0% + + + + align:start position:0% + +and then it must degrade into non-toxic + + align:start position:0% +and then it must degrade into non-toxic + + + align:start position:0% +and then it must degrade into non-toxic +components + + align:start position:0% + + + + align:start position:0% + +so there's some requirements for the + + align:start position:0% +so there's some requirements for the + + + align:start position:0% +so there's some requirements for the +cellular structure too and what you want + + align:start position:0% +cellular structure too and what you want + + + align:start position:0% +cellular structure too and what you want +to have is a large volume fraction + + align:start position:0% +to have is a large volume fraction + + + align:start position:0% +to have is a large volume fraction +interconnected pores and so you want + + align:start position:0% +interconnected pores and so you want + + + align:start position:0% +interconnected pores and so you want +that to facilitate the cell migration + + align:start position:0% +that to facilitate the cell migration + + + align:start position:0% +that to facilitate the cell migration +and also the transport of nutrients into + + align:start position:0% +and also the transport of nutrients into + + + align:start position:0% +and also the transport of nutrients into +the cells + + align:start position:0% + + + + align:start position:0% + +for for + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +so you also want the pore size with the + + align:start position:0% +so you also want the pore size with the + + + align:start position:0% +so you also want the pore size with the +pore size to be within a critical range + + align:start position:0% +pore size to be within a critical range + + + align:start position:0% +pore size to be within a critical range +so you need the pores bigger than a + + align:start position:0% +so you need the pores bigger than a + + + align:start position:0% +so you need the pores bigger than a +lower limit so the cells can Mig migrate + + align:start position:0% +lower limit so the cells can Mig migrate + + + align:start position:0% +lower limit so the cells can Mig migrate +through easily can kind of get in there + + align:start position:0% +through easily can kind of get in there + + + align:start position:0% +through easily can kind of get in there +and you want the porees size to be less + + align:start position:0% +and you want the porees size to be less + + + align:start position:0% +and you want the porees size to be less +than an upper limit to have enough + + align:start position:0% +than an upper limit to have enough + + + align:start position:0% +than an upper limit to have enough +surface area to have enough binding SES + + align:start position:0% +surface area to have enough binding SES + + + align:start position:0% +surface area to have enough binding SES +to actually attach cells and for + + align:start position:0% +to actually attach cells and for + + + align:start position:0% +to actually attach cells and for +different tissues there's different + + align:start position:0% +different tissues there's different + + + align:start position:0% +different tissues there's different +critical ranges of the pore size + + align:start position:0% + + + + align:start position:0% + +so for example for + + align:start position:0% +so for example for + + + align:start position:0% +so for example for +skin they found that you want to have a + + align:start position:0% +skin they found that you want to have a + + + align:start position:0% +skin they found that you want to have a +pore size between about 20 + + align:start position:0% +pore size between about 20 + + + align:start position:0% +pore size between about 20 +microns and about 150 + + align:start position:0% +microns and about 150 + + + align:start position:0% +microns and about 150 +microns and for + + align:start position:0% + + + + align:start position:0% + +bone the pore sizes that people tend to + + align:start position:0% +bone the pore sizes that people tend to + + + align:start position:0% +bone the pore sizes that people tend to +use are between about 100 and + + align:start position:0% +use are between about 100 and + + + align:start position:0% +use are between about 100 and + + align:start position:0% + + + + align:start position:0% + +microns so there's the pore size and one + + align:start position:0% +microns so there's the pore size and one + + + align:start position:0% +microns so there's the pore size and one +other feature is that the POR geometry + + align:start position:0% +other feature is that the POR geometry + + + align:start position:0% +other feature is that the POR geometry +should be conducive for the cell type so + + align:start position:0% +should be conducive for the cell type so + + + align:start position:0% +should be conducive for the cell type so +lots of cells are somewhat equiaxed + + align:start position:0% +lots of cells are somewhat equiaxed + + + align:start position:0% +lots of cells are somewhat equiaxed +maybe a little elongated uh but if you + + align:start position:0% +maybe a little elongated uh but if you + + + align:start position:0% +maybe a little elongated uh but if you +look at something like nerve cells like + + align:start position:0% +look at something like nerve cells like + + + align:start position:0% +look at something like nerve cells like +peripheral nerve they're incredibly + + align:start position:0% +peripheral nerve they're incredibly + + + align:start position:0% +peripheral nerve they're incredibly +elongated so you want to have pores in + + align:start position:0% +elongated so you want to have pores in + + + align:start position:0% +elongated so you want to have pores in +the scaffold that are also very + + align:start position:0% +the scaffold that are also very + + + align:start position:0% +the scaffold that are also very +elongated + + align:start position:0% + + + + align:start position:0% + +and then for the overall scaffold it + + align:start position:0% +and then for the overall scaffold it + + + align:start position:0% +and then for the overall scaffold it +needs to have some mechanical Integrity + + align:start position:0% +needs to have some mechanical Integrity + + + align:start position:0% +needs to have some mechanical Integrity +you guys okay yeah we're good um oh achy + + align:start position:0% +you guys okay yeah we're good um oh achy + + + align:start position:0% +you guys okay yeah we're good um oh achy +yeah I don't I know + + align:start position:0% +yeah I don't I know + + + align:start position:0% +yeah I don't I know +um uh so you want to have some overall + + align:start position:0% +um uh so you want to have some overall + + + align:start position:0% +um uh so you want to have some overall +mechanical Integrity I mean the thing + + align:start position:0% +mechanical Integrity I mean the thing + + + align:start position:0% +mechanical Integrity I mean the thing +has to be put into the body in surgery + + align:start position:0% +has to be put into the body in surgery + + + align:start position:0% +has to be put into the body in surgery +and people are going to be pushing and + + align:start position:0% +and people are going to be pushing and + + + align:start position:0% +and people are going to be pushing and +poking at it and so there has to have + + align:start position:0% +poking at it and so there has to have + + + align:start position:0% +poking at it and so there has to have +some just overall mechanical Integrity + + align:start position:0% +some just overall mechanical Integrity + + + align:start position:0% +some just overall mechanical Integrity +also it it turns out that if you put + + align:start position:0% +also it it turns out that if you put + + + align:start position:0% +also it it turns out that if you put +stem cells into scaffolds uh the types + + align:start position:0% +stem cells into scaffolds uh the types + + + align:start position:0% +stem cells into scaffolds uh the types +of cells they differentiate into depends + + align:start position:0% +of cells they differentiate into depends + + + align:start position:0% +of cells they differentiate into depends +in part on the stiffness of the scaffold + + align:start position:0% +in part on the stiffness of the scaffold + + + align:start position:0% +in part on the stiffness of the scaffold +so you want to be able to control the + + align:start position:0% +so you want to be able to control the + + + align:start position:0% +so you want to be able to control the +stiffness of the scaffold how they do + + align:start position:0% +stiffness of the scaffold how they do + + + align:start position:0% +stiffness of the scaffold how they do +this research do they use like animals + + align:start position:0% +this research do they use like animals + + + align:start position:0% +this research do they use like animals +or they do yeah so the question is how + + align:start position:0% +or they do yeah so the question is how + + + align:start position:0% +or they do yeah so the question is how +do they do the research so they do a + + align:start position:0% +do they do the research so they do a + + + align:start position:0% +do they do the research so they do a +sort of a series of different things so + + align:start position:0% +sort of a series of different things so + + + align:start position:0% +sort of a series of different things so +uh you know at one level you could have + + align:start position:0% +uh you know at one level you could have + + + align:start position:0% +uh you know at one level you could have +the scaffold and you'd put cells on it + + align:start position:0% +the scaffold and you'd put cells on it + + + align:start position:0% +the scaffold and you'd put cells on it +so you could put you know say you're + + align:start position:0% +so you could put you know say you're + + + align:start position:0% +so you could put you know say you're +making a bone scaffold you'd put + + align:start position:0% +making a bone scaffold you'd put + + + align:start position:0% +making a bone scaffold you'd put +osteocytes onto it so so one level you + + align:start position:0% +osteocytes onto it so so one level you + + + align:start position:0% +osteocytes onto it so so one level you +just put cells onto it + + align:start position:0% +just put cells onto it + + + align:start position:0% +just put cells onto it +and you want to see you know are the + + align:start position:0% +and you want to see you know are the + + + align:start position:0% +and you want to see you know are the +cells attaching are they dying are they + + align:start position:0% +cells attaching are they dying are they + + + align:start position:0% +cells attaching are they dying are they +proliferating so you know sometimes what + + align:start position:0% +proliferating so you know sometimes what + + + align:start position:0% +proliferating so you know sometimes what +people will do is put this they'll see a + + align:start position:0% +people will do is put this they'll see a + + + align:start position:0% +people will do is put this they'll see a +certain number of cells at a certain + + align:start position:0% +certain number of cells at a certain + + + align:start position:0% +certain number of cells at a certain +time say Time Zero then they'll um look + + align:start position:0% +time say Time Zero then they'll um look + + + align:start position:0% +time say Time Zero then they'll um look +at how many cells are attached at 24 + + align:start position:0% +at how many cells are attached at 24 + + + align:start position:0% +at how many cells are attached at 24 +hours or 48 hours and you kind of see um + + align:start position:0% +hours or 48 hours and you kind of see um + + + align:start position:0% +hours or 48 hours and you kind of see um +the cell attachment you can measure + + align:start position:0% +the cell attachment you can measure + + + align:start position:0% +the cell attachment you can measure +relatively easily um another thing + + align:start position:0% +relatively easily um another thing + + + align:start position:0% +relatively easily um another thing +people do is animal studies so for + + align:start position:0% +people do is animal studies so for + + + align:start position:0% +people do is animal studies so for +instance yanos does research on + + align:start position:0% +instance yanos does research on + + + align:start position:0% +instance yanos does research on +peripheral nerves and scaffold for + + align:start position:0% +peripheral nerves and scaffold for + + + align:start position:0% +peripheral nerves and scaffold for +peripheral nerves and they cut a piece + + align:start position:0% +peripheral nerves and they cut a piece + + + align:start position:0% +peripheral nerves and they cut a piece +out of the sciatic nerve of rats so + + align:start position:0% +out of the sciatic nerve of rats so + + + align:start position:0% +out of the sciatic nerve of rats so +obviously they have a surgeon and do a + + align:start position:0% +obviously they have a surgeon and do a + + + align:start position:0% +obviously they have a surgeon and do a +surgery thing with it you can't just + + align:start position:0% +surgery thing with it you can't just + + + align:start position:0% +surgery thing with it you can't just +kind of do this in the lab you've got to + + align:start position:0% +kind of do this in the lab you've got to + + + align:start position:0% +kind of do this in the lab you've got to +get permissions and stuff to do it um + + align:start position:0% +get permissions and stuff to do it um + + + align:start position:0% +get permissions and stuff to do it um +and then they put in the scaffold and + + align:start position:0% +and then they put in the scaffold and + + + align:start position:0% +and then they put in the scaffold and +the scaffold is actually in a tube and + + align:start position:0% +the scaffold is actually in a tube and + + + align:start position:0% +the scaffold is actually in a tube and +so they put the two stumps of the nerve + + align:start position:0% +so they put the two stumps of the nerve + + + align:start position:0% +so they put the two stumps of the nerve +end at either end of the tube and then + + align:start position:0% +end at either end of the tube and then + + + align:start position:0% +end at either end of the tube and then +the tube's filled with the sort of + + align:start position:0% +the tube's filled with the sort of + + + align:start position:0% +the tube's filled with the sort of +porous scaffold that we're talking about + + align:start position:0% +porous scaffold that we're talking about + + + align:start position:0% +porous scaffold that we're talking about +here and then they you know they wait + + align:start position:0% +here and then they you know they wait + + + align:start position:0% +here and then they you know they wait +some period of time um and they you know + + align:start position:0% +some period of time um and they you know + + + align:start position:0% +some period of time um and they you know +they take video of rat running things + + align:start position:0% +they take video of rat running things + + + align:start position:0% +they take video of rat running things +like that they um they then sacrifice + + align:start position:0% +like that they um they then sacrifice + + + align:start position:0% +like that they um they then sacrifice +the rat and they do histology and they + + align:start position:0% +the rat and they do histology and they + + + align:start position:0% +the rat and they do histology and they +look at the the sort of cross-sections + + align:start position:0% +look at the the sort of cross-sections + + + align:start position:0% +look at the the sort of cross-sections +and see what it looks like um and so I'm + + align:start position:0% +and see what it looks like um and so I'm + + + align:start position:0% +and see what it looks like um and so I'm +going to talk next time about this + + align:start position:0% +going to talk next time about this + + + align:start position:0% +going to talk next time about this +osteochondral scaffold we worked on so + + align:start position:0% +osteochondral scaffold we worked on so + + + align:start position:0% +osteochondral scaffold we worked on so +we did cell studies we did goat studies + + align:start position:0% +we did cell studies we did goat studies + + + align:start position:0% +we did cell studies we did goat studies +we put into goat knees there was a + + align:start position:0% +we put into goat knees there was a + + + align:start position:0% +we put into goat knees there was a +longer term sheep study and then uh the + + align:start position:0% +longer term sheep study and then uh the + + + align:start position:0% +longer term sheep study and then uh the +the student who's in Cambridge England + + align:start position:0% +the student who's in Cambridge England + + + align:start position:0% +the student who's in Cambridge England +started up a company and um he ended up + + align:start position:0% +started up a company and um he ended up + + + align:start position:0% +started up a company and um he ended up +getting approval in Europe to start + + align:start position:0% +getting approval in Europe to start + + + align:start position:0% +getting approval in Europe to start +clinical trials and and you know he + + align:start position:0% +clinical trials and and you know he + + + align:start position:0% +clinical trials and and you know he +worked with an orthopedic surgeon who + + align:start position:0% +worked with an orthopedic surgeon who + + + align:start position:0% +worked with an orthopedic surgeon who +started putting in people but typically + + align:start position:0% +started putting in people but typically + + + align:start position:0% +started putting in people but typically +they're sort of looking at cells looking + + align:start position:0% +they're sort of looking at cells looking + + + align:start position:0% +they're sort of looking at cells looking +at animals before you get to the people + + align:start position:0% +at animals before you get to the people + + + align:start position:0% +at animals before you get to the people +stage okay and you know one of the + + align:start position:0% +stage okay and you know one of the + + + align:start position:0% +stage okay and you know one of the +things people do when they're making + + align:start position:0% +things people do when they're making + + + align:start position:0% +things people do when they're making +these scaffolds is you want to use + + align:start position:0% +these scaffolds is you want to use + + + align:start position:0% +these scaffolds is you want to use +materials that already have some sort of + + align:start position:0% +materials that already have some sort of + + + align:start position:0% +materials that already have some sort of +regulatory approval so say FDA approval + + align:start position:0% +regulatory approval so say FDA approval + + + align:start position:0% +regulatory approval so say FDA approval +or approval in Europe so typically + + align:start position:0% +or approval in Europe so typically + + + align:start position:0% +or approval in Europe so typically +people don't start with a brand new + + align:start position:0% +people don't start with a brand new + + + align:start position:0% +people don't start with a brand new +material from scratch because to get + + align:start position:0% +material from scratch because to get + + + align:start position:0% +material from scratch because to get +approval for that would just take a very + + align:start position:0% +approval for that would just take a very + + + align:start position:0% +approval for that would just take a very +long time so so typically people start + + align:start position:0% +long time so so typically people start + + + align:start position:0% +long time so so typically people start +with the solid material is already + + align:start position:0% +with the solid material is already + + + align:start position:0% +with the solid material is already +approved for some other sort of use so + + align:start position:0% +approved for some other sort of use so + + + align:start position:0% +approved for some other sort of use so +okay um so One requirement for the + + align:start position:0% +okay um so One requirement for the + + + align:start position:0% +okay um so One requirement for the +overall scaffold is it has to have + + align:start position:0% +overall scaffold is it has to have + + + align:start position:0% +overall scaffold is it has to have +sufficient mechanical + + align:start position:0% +sufficient mechanical + + + align:start position:0% +sufficient mechanical +Integrity uh sufficient + + align:start position:0% + + + + align:start position:0% + +and then also as I mentioned the + + align:start position:0% +and then also as I mentioned the + + + align:start position:0% +and then also as I mentioned the +stiffness of the scaffold can affect the + + align:start position:0% +stiffness of the scaffold can affect the + + + align:start position:0% +stiffness of the scaffold can affect the +differentiation of + + align:start position:0% + + + + align:start position:0% + +cells and the other thing that is really + + align:start position:0% +cells and the other thing that is really + + + align:start position:0% +cells and the other thing that is really +a factor for the overall SC scaffold is + + align:start position:0% +a factor for the overall SC scaffold is + + + align:start position:0% +a factor for the overall SC scaffold is +you want to control the rate of + + align:start position:0% +you want to control the rate of + + + align:start position:0% +you want to control the rate of +degradation of the overall scaffold so + + align:start position:0% +degradation of the overall scaffold so + + + align:start position:0% +degradation of the overall scaffold so +you want that rate to be matched to the + + align:start position:0% +you want that rate to be matched to the + + + align:start position:0% +you want that rate to be matched to the +rate at which the new tissue is + + align:start position:0% +rate at which the new tissue is + + + align:start position:0% +rate at which the new tissue is +forming so it has to degrade at a + + align:start position:0% +forming so it has to degrade at a + + + align:start position:0% +forming so it has to degrade at a +controllable rate + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +uh so I wanted to talk about the + + align:start position:0% +uh so I wanted to talk about the + + + align:start position:0% +uh so I wanted to talk about the +materials that people use and you can + + align:start position:0% +materials that people use and you can + + + align:start position:0% +materials that people use and you can +kind of break them down into a few + + align:start position:0% +kind of break them down into a few + + + align:start position:0% +kind of break them down into a few +classes so one class is natural polymers + + align:start position:0% +classes so one class is natural polymers + + + align:start position:0% +classes so one class is natural polymers +so things like collagen so you can get + + align:start position:0% +so things like collagen so you can get + + + align:start position:0% +so things like collagen so you can get +collagen and that's an example up there + + align:start position:0% +collagen and that's an example up there + + + align:start position:0% +collagen and that's an example up there +of a scaffold that's made with collagen + + align:start position:0% +of a scaffold that's made with collagen + + + align:start position:0% +of a scaffold that's made with collagen +another class of materials is synthetic + + align:start position:0% +another class of materials is synthetic + + + align:start position:0% +another class of materials is synthetic +biomaterials and if you've had stitches + + align:start position:0% +biomaterials and if you've had stitches + + + align:start position:0% +biomaterials and if you've had stitches +or surgery uh you may know that some of + + align:start position:0% +or surgery uh you may know that some of + + + align:start position:0% +or surgery uh you may know that some of +the sutures they use are resorbable so + + align:start position:0% +the sutures they use are resorbable so + + + align:start position:0% +the sutures they use are resorbable so +some of those polymers that they use for + + align:start position:0% +some of those polymers that they use for + + + align:start position:0% +some of those polymers that they use for +resorbable sutures are also used for uh + + align:start position:0% +resorbable sutures are also used for uh + + + align:start position:0% +resorbable sutures are also used for uh +tissue engineering scaffold and then + + align:start position:0% +tissue engineering scaffold and then + + + align:start position:0% +tissue engineering scaffold and then +there's also Hydro gels that people use + + align:start position:0% +there's also Hydro gels that people use + + + align:start position:0% +there's also Hydro gels that people use +as well so those are probably the three + + align:start position:0% +as well so those are probably the three + + + align:start position:0% +as well so those are probably the three +main groups are um sort of natural + + align:start position:0% +main groups are um sort of natural + + + align:start position:0% +main groups are um sort of natural +polymers synthetic + + align:start position:0% +polymers synthetic + + + align:start position:0% +polymers synthetic +biopolymers and I guess the hydrogels + + align:start position:0% +biopolymers and I guess the hydrogels + + + align:start position:0% +biopolymers and I guess the hydrogels +are sort of a subset of the synthetic + + align:start position:0% + + + + align:start position:0% + +biopolymers so collagen is probably the + + align:start position:0% +biopolymers so collagen is probably the + + + align:start position:0% +biopolymers so collagen is probably the +most common kind of natural polymer + + align:start position:0% +most common kind of natural polymer + + + align:start position:0% +most common kind of natural polymer +that's used U they also use gags and + + align:start position:0% +that's used U they also use gags and + + + align:start position:0% +that's used U they also use gags and +this scaffold up here is made by making + + align:start position:0% +this scaffold up here is made by making + + + align:start position:0% +this scaffold up here is made by making +a co-precipitate of collagen with a gag + + align:start position:0% +a co-precipitate of collagen with a gag + + + align:start position:0% +a co-precipitate of collagen with a gag +Condren sulfate people also use + + align:start position:0% + + + + align:start position:0% + +alginate I think one of the project + + align:start position:0% +alginate I think one of the project + + + align:start position:0% +alginate I think one of the project +groups you guys are going to make some + + align:start position:0% +groups you guys are going to make some + + + align:start position:0% +groups you guys are going to make some +sort of alate scaffold right no scal + + align:start position:0% +sort of alate scaffold right no scal + + + align:start position:0% +sort of alate scaffold right no scal +foamy thing yeah um and people also use + + align:start position:0% +foamy thing yeah um and people also use + + + align:start position:0% +foamy thing yeah um and people also use +something called + + align:start position:0% +something called + + + align:start position:0% +something called +kosan which is a derivative of kiten + + align:start position:0% +kosan which is a derivative of kiten + + + align:start position:0% +kosan which is a derivative of kiten +which is what's in the exoskeleton of + + align:start position:0% +which is what's in the exoskeleton of + + + align:start position:0% +which is what's in the exoskeleton of +insects and things like lobsters so + + align:start position:0% +insects and things like lobsters so + + + align:start position:0% +insects and things like lobsters so +those would be all examples of natural + + align:start position:0% +those would be all examples of natural + + + align:start position:0% +those would be all examples of natural +polymers that can be used and people + + align:start position:0% +polymers that can be used and people + + + align:start position:0% +polymers that can be used and people +have + + align:start position:0% +have + + + align:start position:0% +have +tried I'm going to talk a bit more about + + align:start position:0% +tried I'm going to talk a bit more about + + + align:start position:0% +tried I'm going to talk a bit more about +collagen just because it's the most + + align:start position:0% +collagen just because it's the most + + + align:start position:0% +collagen just because it's the most +common one so collagen's a major + + align:start position:0% +common one so collagen's a major + + + align:start position:0% +common one so collagen's a major +component in the natural extracellular + + align:start position:0% +component in the natural extracellular + + + align:start position:0% +component in the natural extracellular +Matrix and not surprisingly it has + + align:start position:0% +Matrix and not surprisingly it has + + + align:start position:0% +Matrix and not surprisingly it has +binding sites for cells to attach to it + + align:start position:0% +binding sites for cells to attach to it + + + align:start position:0% +binding sites for cells to attach to it +so if you use that that kind of takes + + align:start position:0% +so if you use that that kind of takes + + + align:start position:0% +so if you use that that kind of takes +care of that + + align:start position:0% + + + + align:start position:0% + +issue down here + + align:start position:0% + + + + align:start position:0% + +so collagen exists in many types of + + align:start position:0% +so collagen exists in many types of + + + align:start position:0% +so collagen exists in many types of +tissues exists in skin exists in bone + + align:start position:0% +tissues exists in skin exists in bone + + + align:start position:0% +tissues exists in skin exists in bone +cartilage ligament tendon + + align:start position:0% + + + + align:start position:0% + +cartilage so it's very common + + align:start position:0% +cartilage so it's very common + + + align:start position:0% +cartilage so it's very common +it has surface binding + + align:start position:0% +it has surface binding + + + align:start position:0% +it has surface binding +sites for cells + + align:start position:0% + + + + align:start position:0% + +um it has a relatively low young + + align:start position:0% + + + + align:start position:0% + +modulus so the low Young's modulus is a + + align:start position:0% +modulus so the low Young's modulus is a + + + align:start position:0% +modulus so the low Young's modulus is a +little less than a gigap + + align:start position:0% + + + + align:start position:0% + +pascal uh but you can increase the + + align:start position:0% +pascal uh but you can increase the + + + align:start position:0% +pascal uh but you can increase the +modulus by either cross- linking or by + + align:start position:0% +modulus by either cross- linking or by + + + align:start position:0% +modulus by either cross- linking or by +using it in conjunction with some + + align:start position:0% +using it in conjunction with some + + + align:start position:0% +using it in conjunction with some +synthetic polymers + + align:start position:0% + + + + align:start position:0% + +and I'm going to talk a little bit about + + align:start position:0% +and I'm going to talk a little bit about + + + align:start position:0% +and I'm going to talk a little bit about +how you make these scaffolds up here and + + align:start position:0% +how you make these scaffolds up here and + + + align:start position:0% +how you make these scaffolds up here and +the first step in doing making those + + align:start position:0% +the first step in doing making those + + + align:start position:0% +the first step in doing making those +scaffolds is you put the collagen in + + align:start position:0% +scaffolds is you put the collagen in + + + align:start position:0% +scaffolds is you put the collagen in +acetic acid and then you add the + + align:start position:0% +acetic acid and then you add the + + + align:start position:0% +acetic acid and then you add the +glycosaminoglycan and it forms a + + align:start position:0% +glycosaminoglycan and it forms a + + + align:start position:0% +glycosaminoglycan and it forms a +co-precipitate and the fact that it + + align:start position:0% +co-precipitate and the fact that it + + + align:start position:0% +co-precipitate and the fact that it +forms a go coprecipitate with the uh + + align:start position:0% +forms a go coprecipitate with the uh + + + align:start position:0% +forms a go coprecipitate with the uh +glycosaminoglycan the gag means that you + + align:start position:0% +glycosaminoglycan the gag means that you + + + align:start position:0% +glycosaminoglycan the gag means that you +can use a freeze drying process and + + align:start position:0% +can use a freeze drying process and + + + align:start position:0% +can use a freeze drying process and +that's how that's made + + align:start position:0% + + + + align:start position:0% + +so that's collagen is one option so then + + align:start position:0% +so that's collagen is one option so then + + + align:start position:0% +so that's collagen is one option so then +synthetic biopolymers is another + + align:start position:0% + + + + align:start position:0% + +option and as I said typically they use + + align:start position:0% +option and as I said typically they use + + + align:start position:0% +option and as I said typically they use +the materials that are used for + + align:start position:0% +the materials that are used for + + + align:start position:0% +the materials that are used for +resorbable + + align:start position:0% + + + + align:start position:0% + +sutures so there's several of those + + align:start position:0% +sutures so there's several of those + + + align:start position:0% +sutures so there's several of those +there's something called + + align:start position:0% +there's something called + + + align:start position:0% +there's something called +PGA that's polyglycolic acid + + align:start position:0% + + + + align:start position:0% + +there's something called pla that's + + align:start position:0% +there's something called pla that's + + + align:start position:0% +there's something called pla that's +polylactic + + align:start position:0% + + + + align:start position:0% + +acid and then you can combine those two + + align:start position:0% +acid and then you can combine those two + + + align:start position:0% +acid and then you can combine those two +and make something called plga + + align:start position:0% +and make something called plga + + + align:start position:0% +and make something called plga +polylactic Co glycolic acid + + align:start position:0% + + + + align:start position:0% + +and you can control the degradation rate + + align:start position:0% +and you can control the degradation rate + + + align:start position:0% +and you can control the degradation rate +of these things by controlling the + + align:start position:0% +of these things by controlling the + + + align:start position:0% +of these things by controlling the +molecular weight and in this case you + + align:start position:0% +molecular weight and in this case you + + + align:start position:0% +molecular weight and in this case you +can also control it by controlling how + + align:start position:0% +can also control it by controlling how + + + align:start position:0% +can also control it by controlling how +much of each of those things you put in + + align:start position:0% + + + + align:start position:0% + +and there's another one called + + align:start position:0% + + + + align:start position:0% + +polycaprolactone so those are + + align:start position:0% +polycaprolactone so those are + + + align:start position:0% +polycaprolactone so those are +several uh synthetic biop poers that + + align:start position:0% +several uh synthetic biop poers that + + + align:start position:0% +several uh synthetic biop poers that +people use there's lots of different + + align:start position:0% +people use there's lots of different + + + align:start position:0% +people use there's lots of different +materials but these are just some + + align:start position:0% +materials but these are just some + + + align:start position:0% +materials but these are just some +typical ones + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +and then another class are hydrogels + + align:start position:0% +and then another class are hydrogels + + + align:start position:0% +and then another class are hydrogels +which are produced by crosslinking water + + align:start position:0% +which are produced by crosslinking water + + + align:start position:0% +which are produced by crosslinking water +soluble polymers to form an insoluble + + align:start position:0% +soluble polymers to form an insoluble + + + align:start position:0% +soluble polymers to form an insoluble +Network + + align:start position:0% + + + + align:start position:0% + +and those are typically used for soft + + align:start position:0% + + + + align:start position:0% + +tissues so sometimes they're used for + + align:start position:0% +tissues so sometimes they're used for + + + align:start position:0% +tissues so sometimes they're used for +things like cartilage and this again + + align:start position:0% +things like cartilage and this again + + + align:start position:0% +things like cartilage and this again +there's a few different materials that + + align:start position:0% +there's a few different materials that + + + align:start position:0% +there's a few different materials that +are commonly used one's Peg po + + align:start position:0% +are commonly used one's Peg po + + + align:start position:0% +are commonly used one's Peg po +polyethylene + + align:start position:0% + + + + align:start position:0% + +glycol one's + + align:start position:0% +glycol one's + + + align:start position:0% +glycol one's +PVA polyvinyl + + align:start position:0% + + + + align:start position:0% + +alcohol and another one's + + align:start position:0% +alcohol and another one's + + + align:start position:0% +alcohol and another one's +paa polyacrylic acid + + align:start position:0% + + + + align:start position:0% + +so for these synthetic polymers there's + + align:start position:0% +so for these synthetic polymers there's + + + align:start position:0% +so for these synthetic polymers there's +many different processing techniques + + align:start position:0% +many different processing techniques + + + align:start position:0% +many different processing techniques +available and I'll talk a little bit + + align:start position:0% +available and I'll talk a little bit + + + align:start position:0% +available and I'll talk a little bit +about some of the processing techniques + + align:start position:0% +about some of the processing techniques + + + align:start position:0% +about some of the processing techniques +but one of the uh limitations is they + + align:start position:0% +but one of the uh limitations is they + + + align:start position:0% +but one of the uh limitations is they +don't have natural binding sites and you + + align:start position:0% +don't have natural binding sites and you + + + align:start position:0% +don't have natural binding sites and you +have to coat them with some sort of um + + align:start position:0% +have to coat them with some sort of um + + + align:start position:0% +have to coat them with some sort of um +binding agent like an adhesive protein + + align:start position:0% +binding agent like an adhesive protein + + + align:start position:0% +binding agent like an adhesive protein +to get the cells to attach to them + + align:start position:0% + + + + align:start position:0% + +and then as I mentioned before you have + + align:start position:0% +and then as I mentioned before you have + + + align:start position:0% +and then as I mentioned before you have +to make sure that whatever material you + + align:start position:0% +to make sure that whatever material you + + + align:start position:0% +to make sure that whatever material you +choose if it's a synthetic material but + + align:start position:0% +choose if it's a synthetic material but + + + align:start position:0% +choose if it's a synthetic material but +when it degrades it's not toxic uh to + + align:start position:0% +when it degrades it's not toxic uh to + + + align:start position:0% +when it degrades it's not toxic uh to +the cells because you don't want to have + + align:start position:0% +the cells because you don't want to have + + + align:start position:0% +the cells because you don't want to have +some sort of toxic reaction or + + align:start position:0% + + + + align:start position:0% + +inflammation okay so there's a couple + + align:start position:0% +inflammation okay so there's a couple + + + align:start position:0% +inflammation okay so there's a couple +more things about + + align:start position:0% +more things about + + + align:start position:0% +more things about +materials so those are all sort of + + align:start position:0% +materials so those are all sort of + + + align:start position:0% +materials so those are all sort of +polymer-based materials when people are + + align:start position:0% +polymer-based materials when people are + + + align:start position:0% +polymer-based materials when people are +trying to make scaffolds for bone tissue + + align:start position:0% +trying to make scaffolds for bone tissue + + + align:start position:0% +trying to make scaffolds for bone tissue +engineering they also include a calcium + + align:start position:0% +engineering they also include a calcium + + + align:start position:0% +engineering they also include a calcium +phosphate mineral and there's different + + align:start position:0% +phosphate mineral and there's different + + + align:start position:0% +phosphate mineral and there's different +versions of the calcium phosphate so + + align:start position:0% +versions of the calcium phosphate so + + + align:start position:0% +versions of the calcium phosphate so +they can include you can buy for + + align:start position:0% +they can include you can buy for + + + align:start position:0% +they can include you can buy for +instance hydroxy appetite powders now + + align:start position:0% +instance hydroxy appetite powders now + + + align:start position:0% +instance hydroxy appetite powders now +there's another calcium phosphate called + + align:start position:0% +there's another calcium phosphate called + + + align:start position:0% +there's another calcium phosphate called +octacalcium phosphate which will with + + align:start position:0% +octacalcium phosphate which will with + + + align:start position:0% +octacalcium phosphate which will with +water uh turn into hydroxyapetite so + + align:start position:0% +water uh turn into hydroxyapetite so + + + align:start position:0% +water uh turn into hydroxyapetite so +typically this this mineral some sort of + + align:start position:0% +typically this this mineral some sort of + + + align:start position:0% +typically this this mineral some sort of +calcium phosphate is combined with + + align:start position:0% +calcium phosphate is combined with + + + align:start position:0% +calcium phosphate is combined with +either collagen or with one of these + + align:start position:0% +either collagen or with one of these + + + align:start position:0% +either collagen or with one of these +synthetic biopolymers + + align:start position:0% + + + + align:start position:0% + +and one other option is something called + + align:start position:0% +and one other option is something called + + + align:start position:0% +and one other option is something called +an acellular scaffold and what that is + + align:start position:0% +an acellular scaffold and what that is + + + align:start position:0% +an acellular scaffold and what that is +is they take some natural tissue and + + align:start position:0% +is they take some natural tissue and + + + align:start position:0% +is they take some natural tissue and +they remove all the cell material from + + align:start position:0% +they remove all the cell material from + + + align:start position:0% +they remove all the cell material from +it and so when they remove all the cell + + align:start position:0% +it and so when they remove all the cell + + + align:start position:0% +it and so when they remove all the cell +material what they're left with is the + + align:start position:0% +material what they're left with is the + + + align:start position:0% +material what they're left with is the +native ECM and that's called an a + + align:start position:0% +native ECM and that's called an a + + + align:start position:0% +native ECM and that's called an a +cellular + + align:start position:0% +cellular + + + align:start position:0% +cellular +scaffold so it's a a + + align:start position:0% +scaffold so it's a a + + + align:start position:0% +scaffold so it's a a +native ECM with all the cell matter + + align:start position:0% +native ECM with all the cell matter + + + align:start position:0% +native ECM with all the cell matter +removed + + align:start position:0% + + + + align:start position:0% + +and they remove the cells by they can + + align:start position:0% +and they remove the cells by they can + + + align:start position:0% +and they remove the cells by they can +use sort of a physical agitation or + + align:start position:0% +use sort of a physical agitation or + + + align:start position:0% +use sort of a physical agitation or +chemical um or or using enzymatic + + align:start position:0% +chemical um or or using enzymatic + + + align:start position:0% +chemical um or or using enzymatic +methods using something like Tron to get + + align:start position:0% +methods using something like Tron to get + + + align:start position:0% +methods using something like Tron to get +rid of the cell so there's ways that + + align:start position:0% +rid of the cell so there's ways that + + + align:start position:0% +rid of the cell so there's ways that +they can get rid of the + + align:start position:0% +they can get rid of the + + + align:start position:0% +they can get rid of the +cells okay so are we good so far so + + align:start position:0% +cells okay so are we good so far so + + + align:start position:0% +cells okay so are we good so far so +there's some requirements for what + + align:start position:0% +there's some requirements for what + + + align:start position:0% +there's some requirements for what +materials we kind of use what the cell + + align:start position:0% +materials we kind of use what the cell + + + align:start position:0% +materials we kind of use what the cell +structure should be and these are some + + align:start position:0% +structure should be and these are some + + + align:start position:0% +structure should be and these are some +examples of typical materials so I want + + align:start position:0% +examples of typical materials so I want + + + align:start position:0% +examples of typical materials so I want +to talk a little bit about the process + + align:start position:0% +to talk a little bit about the process + + + align:start position:0% +to talk a little bit about the process +processing of the + + align:start position:0% +processing of the + + + align:start position:0% +processing of the +materials um Let Me Wait Till people + + align:start position:0% +materials um Let Me Wait Till people + + + align:start position:0% +materials um Let Me Wait Till people +catch up a + + align:start position:0% + + + + align:start position:0% + +little oh and I have some scaffolds I + + align:start position:0% +little oh and I have some scaffolds I + + + align:start position:0% +little oh and I have some scaffolds I +was going to pass + + align:start position:0% +was going to pass + + + align:start position:0% +was going to pass +around so uh this big sheet is a piece + + align:start position:0% +around so uh this big sheet is a piece + + + align:start position:0% +around so uh this big sheet is a piece +of the collagen gag scaffold that I + + align:start position:0% +of the collagen gag scaffold that I + + + align:start position:0% +of the collagen gag scaffold that I +showed a minute ago and then this little + + align:start position:0% +showed a minute ago and then this little + + + align:start position:0% +showed a minute ago and then this little +piece is a mineralized version of that + + align:start position:0% +piece is a mineralized version of that + + + align:start position:0% +piece is a mineralized version of that +so this has the collagen plus um a + + align:start position:0% +so this has the collagen plus um a + + + align:start position:0% +so this has the collagen plus um a +calcium phosphate plus hydroxy appetite + + align:start position:0% +calcium phosphate plus hydroxy appetite + + + align:start position:0% +calcium phosphate plus hydroxy appetite +in + + align:start position:0% + + + + align:start position:0% + +it okay uh so this slide shows some + + align:start position:0% +it okay uh so this slide shows some + + + align:start position:0% +it okay uh so this slide shows some +examples of different uh scaffolds that + + align:start position:0% +examples of different uh scaffolds that + + + align:start position:0% +examples of different uh scaffolds that +people have made and I was going to talk + + align:start position:0% +people have made and I was going to talk + + + align:start position:0% +people have made and I was going to talk +a little bit about some of these methods + + align:start position:0% +a little bit about some of these methods + + + align:start position:0% +a little bit about some of these methods +and I'll why don't I talk about them and + + align:start position:0% +and I'll why don't I talk about them and + + + align:start position:0% +and I'll why don't I talk about them and +then I'll write some notes on the board + + align:start position:0% +then I'll write some notes on the board + + + align:start position:0% +then I'll write some notes on the board +so this top one here on the top left + + align:start position:0% +so this top one here on the top left + + + align:start position:0% +so this top one here on the top left +that's the collagen gag scaffold that's + + align:start position:0% +that's the collagen gag scaffold that's + + + align:start position:0% +that's the collagen gag scaffold that's +made in yanasa group and that's made by + + align:start position:0% +made in yanasa group and that's made by + + + align:start position:0% +made in yanasa group and that's made by +a freeze drying process so you put the + + align:start position:0% +a freeze drying process so you put the + + + align:start position:0% +a freeze drying process so you put the +collagen in acetic acid then you put in + + align:start position:0% +collagen in acetic acid then you put in + + + align:start position:0% +collagen in acetic acid then you put in +the gag the gag the collagen form a + + align:start position:0% +the gag the gag the collagen form a + + + align:start position:0% +the gag the gag the collagen form a +co-precipitate and then you can freeze + + align:start position:0% +co-precipitate and then you can freeze + + + align:start position:0% +co-precipitate and then you can freeze +that and if you freeze it what happens + + align:start position:0% +that and if you freeze it what happens + + + align:start position:0% +that and if you freeze it what happens +is uh you know it's just like if you + + align:start position:0% +is uh you know it's just like if you + + + align:start position:0% +is uh you know it's just like if you +freeze salt water the the water um + + align:start position:0% +freeze salt water the the water um + + + align:start position:0% +freeze salt water the the water um +freezes pure water freezes and you've + + align:start position:0% +freezes pure water freezes and you've + + + align:start position:0% +freezes pure water freezes and you've +got increasingly higher brine content in + + align:start position:0% +got increasingly higher brine content in + + + align:start position:0% +got increasingly higher brine content in +the bit in between the water grains or + + align:start position:0% +the bit in between the water grains or + + + align:start position:0% +the bit in between the water grains or +in in between the ice so you get the + + align:start position:0% +in in between the ice so you get the + + + align:start position:0% +in in between the ice so you get the +sort of solid ice forming and the + + align:start position:0% +sort of solid ice forming and the + + + align:start position:0% +sort of solid ice forming and the +collagen and the gag are kind of swee + + align:start position:0% +collagen and the gag are kind of swee + + + align:start position:0% +collagen and the gag are kind of swee +squeezed into the interstitial bits + + align:start position:0% +squeezed into the interstitial bits + + + align:start position:0% +squeezed into the interstitial bits +between the ice crystals and then if you + + align:start position:0% +between the ice crystals and then if you + + + align:start position:0% +between the ice crystals and then if you +sublimate the ice off you're left with + + align:start position:0% +sublimate the ice off you're left with + + + align:start position:0% +sublimate the ice off you're left with +this porous kind of structure that looks + + align:start position:0% +this porous kind of structure that looks + + + align:start position:0% +this porous kind of structure that looks +like a foam so that's made by a freeze + + align:start position:0% +like a foam so that's made by a freeze + + + align:start position:0% +like a foam so that's made by a freeze +drying process and I I'll go over it in + + align:start position:0% +drying process and I I'll go over it in + + + align:start position:0% +drying process and I I'll go over it in +a bit more detail when I write the notes + + align:start position:0% +a bit more detail when I write the notes + + + align:start position:0% +a bit more detail when I write the notes +on the board you can also foam some of + + align:start position:0% +on the board you can also foam some of + + + align:start position:0% +on the board you can also foam some of +these polymers so just blowing a gas the + + align:start position:0% +these polymers so just blowing a gas the + + + align:start position:0% +these polymers so just blowing a gas the +same way you can blow a gas through you + + align:start position:0% +same way you can blow a gas through you + + + align:start position:0% +same way you can blow a gas through you +know an engineering foam you do the same + + align:start position:0% +know an engineering foam you do the same + + + align:start position:0% +know an engineering foam you do the same +thing with some of these polymers this + + align:start position:0% +thing with some of these polymers this + + + align:start position:0% +thing with some of these polymers this +one's made by foaming you can have a + + align:start position:0% +one's made by foaming you can have a + + + align:start position:0% +one's made by foaming you can have a +fugitive phase process so this is made + + align:start position:0% +fugitive phase process so this is made + + + align:start position:0% +fugitive phase process so this is made +by salt leeching the second row on the + + align:start position:0% +by salt leeching the second row on the + + + align:start position:0% +by salt leeching the second row on the +left there so you could imagine you + + align:start position:0% +left there so you could imagine you + + + align:start position:0% +left there so you could imagine you +could take a polymer powder you could + + align:start position:0% +could take a polymer powder you could + + + align:start position:0% +could take a polymer powder you could +mix it with salt you can sort of mix + + align:start position:0% +mix it with salt you can sort of mix + + + align:start position:0% +mix it with salt you can sort of mix +them up combine them together you heat + + align:start position:0% +them up combine them together you heat + + + align:start position:0% +them up combine them together you heat +it up to get the polymer to melt and to + + align:start position:0% +it up to get the polymer to melt and to + + + align:start position:0% +it up to get the polymer to melt and to +sort of form a a connected mass and then + + align:start position:0% +sort of form a a connected mass and then + + + align:start position:0% +sort of form a a connected mass and then +you Lee out the salt and then you get + + align:start position:0% +you Lee out the salt and then you get + + + align:start position:0% +you Lee out the salt and then you get +pores where the salt was this one here + + align:start position:0% +pores where the salt was this one here + + + align:start position:0% +pores where the salt was this one here +is made by an electri spinning process + + align:start position:0% +is made by an electri spinning process + + + align:start position:0% +is made by an electri spinning process +so you have a nozzle you feed the + + align:start position:0% +so you have a nozzle you feed the + + + align:start position:0% +so you have a nozzle you feed the +polymer through the nozzle then you have + + align:start position:0% +polymer through the nozzle then you have + + + align:start position:0% +polymer through the nozzle then you have +plates that are charged and you get + + align:start position:0% +plates that are charged and you get + + + align:start position:0% +plates that are charged and you get +fibers uh forming and kind of scattered + + align:start position:0% +fibers uh forming and kind of scattered + + + align:start position:0% +fibers uh forming and kind of scattered +in different directions by the electro + + align:start position:0% +in different directions by the electro + + + align:start position:0% +in different directions by the electro +spinning process then this one here + + align:start position:0% +spinning process then this one here + + + align:start position:0% +spinning process then this one here +represents + + align:start position:0% +represents + + + align:start position:0% +represents +um scaffold that are made by + + align:start position:0% +um scaffold that are made by + + + align:start position:0% +um scaffold that are made by +um uh by things like 3D printing + + align:start position:0% +um uh by things like 3D printing + + + align:start position:0% +um uh by things like 3D printing +selective laser centering you can have + + align:start position:0% +selective laser centering you can have + + + align:start position:0% +selective laser centering you can have +um you know laser sensitive sensitive + + align:start position:0% +um you know laser sensitive sensitive + + + align:start position:0% +um you know laser sensitive sensitive +polymer and you can produce uh scaffolds + + align:start position:0% +polymer and you can produce uh scaffolds + + + align:start position:0% +polymer and you can produce uh scaffolds +that way I think the geometry of this + + align:start position:0% +that way I think the geometry of this + + + align:start position:0% +that way I think the geometry of this +one matches I don't know some part in + + align:start position:0% +one matches I don't know some part in + + + align:start position:0% +one matches I don't know some part in +the body I think it was a a knee or + + align:start position:0% +the body I think it was a a knee or + + + align:start position:0% +the body I think it was a a knee or +something like that and then these two + + align:start position:0% +something like that and then these two + + + align:start position:0% +something like that and then these two +examples down here are the acellular + + align:start position:0% +examples down here are the acellular + + + align:start position:0% +examples down here are the acellular +scaffolds that's what I was talking + + align:start position:0% +scaffolds that's what I was talking + + + align:start position:0% +scaffolds that's what I was talking +about at the very end there so those are + + align:start position:0% +about at the very end there so those are + + + align:start position:0% +about at the very end there so those are +from porcine pork heart tissue you know + + align:start position:0% +from porcine pork heart tissue you know + + + align:start position:0% +from porcine pork heart tissue you know +pig heart tissue and those are mostly + + align:start position:0% +pig heart tissue and those are mostly + + + align:start position:0% +pig heart tissue and those are mostly +elastin um and they've had all the cell + + align:start position:0% +elastin um and they've had all the cell + + + align:start position:0% +elastin um and they've had all the cell +matter removed from them okay so you can + + align:start position:0% +matter removed from them okay so you can + + + align:start position:0% +matter removed from them okay so you can +kind of see that these synthetic + + align:start position:0% +kind of see that these synthetic + + + align:start position:0% +kind of see that these synthetic +scaffolds here have a structure that's + + align:start position:0% +scaffolds here have a structure that's + + + align:start position:0% +scaffolds here have a structure that's +not so different from these native ECM + + align:start position:0% +not so different from these native ECM + + + align:start position:0% +not so different from these native ECM +scaffolds down here okay so let me write + + align:start position:0% +scaffolds down here okay so let me write + + + align:start position:0% +scaffolds down here okay so let me write +some of the um things about the + + align:start position:0% +some of the um things about the + + + align:start position:0% +some of the um things about the +processing on the board uh see let me + + align:start position:0% +processing on the board uh see let me + + + align:start position:0% +processing on the board uh see let me +rub this off start over here + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +so these freeze Sky freeze dried + + align:start position:0% +so these freeze Sky freeze dried + + + align:start position:0% +so these freeze Sky freeze dried +scaffolds are used for um the skin + + align:start position:0% +scaffolds are used for um the skin + + + align:start position:0% +scaffolds are used for um the skin +regeneration + + align:start position:0% + + + + align:start position:0% + +and I think I have some more slides here + + align:start position:0% +and I think I have some more slides here + + + align:start position:0% +and I think I have some more slides here +so there kind of a two-step process in + + align:start position:0% +so there kind of a two-step process in + + + align:start position:0% +so there kind of a two-step process in +the first step you make what they call a + + align:start position:0% +the first step you make what they call a + + + align:start position:0% +the first step you make what they call a +slurry so you make the slurry by taking + + align:start position:0% +slurry so you make the slurry by taking + + + align:start position:0% +slurry so you make the slurry by taking +the collagen and uh for skin I think you + + align:start position:0% +the collagen and uh for skin I think you + + + align:start position:0% +the collagen and uh for skin I think you +want type one collagen yeah skin is type + + align:start position:0% +want type one collagen yeah skin is type + + + align:start position:0% +want type one collagen yeah skin is type +one collagen there's different types you + + align:start position:0% +one collagen there's different types you + + + align:start position:0% +one collagen there's different types you +put it in acidic acid and then you add + + align:start position:0% +put it in acidic acid and then you add + + + align:start position:0% +put it in acidic acid and then you add +the gag and we use kren 6 sulfate as + + align:start position:0% +the gag and we use kren 6 sulfate as + + + align:start position:0% +the gag and we use kren 6 sulfate as +just the particular gag that that we use + + align:start position:0% +just the particular gag that that we use + + + align:start position:0% +just the particular gag that that we use +and the one of the things that the acid + + align:start position:0% +and the one of the things that the acid + + + align:start position:0% +and the one of the things that the acid +does is that it swells the collagen and + + align:start position:0% +does is that it swells the collagen and + + + align:start position:0% +does is that it swells the collagen and +collagen has a sort of periodic + + align:start position:0% +collagen has a sort of periodic + + + align:start position:0% +collagen has a sort of periodic +structure in it sort of a periodic + + align:start position:0% +structure in it sort of a periodic + + + align:start position:0% +structure in it sort of a periodic +banding and the acid destroys that + + align:start position:0% +banding and the acid destroys that + + + align:start position:0% +banding and the acid destroys that +periodic banding structure and that + + align:start position:0% +periodic banding structure and that + + + align:start position:0% +periodic banding structure and that +helps um increase the uh resistance to + + align:start position:0% +helps um increase the uh resistance to + + + align:start position:0% +helps um increase the uh resistance to +having some host immune response so that + + align:start position:0% +having some host immune response so that + + + align:start position:0% +having some host immune response so that +you remove the immunological markers and + + align:start position:0% +you remove the immunological markers and + + + align:start position:0% +you remove the immunological markers and +it makes it less likely that the + + align:start position:0% +it makes it less likely that the + + + align:start position:0% +it makes it less likely that the +scaffold's going to get rejected by the + + align:start position:0% +scaffold's going to get rejected by the + + + align:start position:0% +scaffold's going to get rejected by the +body um so then when you put the gag in + + align:start position:0% +body um so then when you put the gag in + + + align:start position:0% +body um so then when you put the gag in +you form a co-precipitate so this next + + align:start position:0% +you form a co-precipitate so this next + + + align:start position:0% +you form a co-precipitate so this next +step just shows kind of mixing the whole + + align:start position:0% +step just shows kind of mixing the whole + + + align:start position:0% +step just shows kind of mixing the whole +thing up and then you've got kind of a + + align:start position:0% +thing up and then you've got kind of a + + + align:start position:0% +thing up and then you've got kind of a +you know little slurry that you can + + align:start position:0% +you know little slurry that you can + + + align:start position:0% +you know little slurry that you can +store and then this is the freeze drying + + align:start position:0% +store and then this is the freeze drying + + + align:start position:0% +store and then this is the freeze drying +step here so you put the the slurry of + + align:start position:0% +step here so you put the the slurry of + + + align:start position:0% +step here so you put the the slurry of +the suspension into a pan kind of like a + + align:start position:0% +the suspension into a pan kind of like a + + + align:start position:0% +the suspension into a pan kind of like a +just like a cookie sheet really um and + + align:start position:0% +just like a cookie sheet really um and + + + align:start position:0% +just like a cookie sheet really um and +then you freeze it so if you think of + + align:start position:0% +then you freeze it so if you think of + + + align:start position:0% +then you freeze it so if you think of +this phase diagram here we have + + align:start position:0% +this phase diagram here we have + + + align:start position:0% +this phase diagram here we have +temperature and pressure so here we have + + align:start position:0% +temperature and pressure so here we have + + + align:start position:0% +temperature and pressure so here we have +liquid solid and Vapor so if you start + + align:start position:0% +liquid solid and Vapor so if you start + + + align:start position:0% +liquid solid and Vapor so if you start +off at this point here you freeze it so + + align:start position:0% +off at this point here you freeze it so + + + align:start position:0% +off at this point here you freeze it so +you reduce the temperature uh so that + + align:start position:0% +you reduce the temperature uh so that + + + align:start position:0% +you reduce the temperature uh so that +forms the the ice and the ice is + + align:start position:0% +forms the the ice and the ice is + + + align:start position:0% +forms the the ice and the ice is +surrounded by the collagen and the gag + + align:start position:0% +surrounded by the collagen and the gag + + + align:start position:0% +surrounded by the collagen and the gag +fibers and then if you do the + + align:start position:0% +fibers and then if you do the + + + align:start position:0% +fibers and then if you do the +sublimation step you reduce the pressure + + align:start position:0% +sublimation step you reduce the pressure + + + align:start position:0% +sublimation step you reduce the pressure +and increase the temperature a bit and + + align:start position:0% +and increase the temperature a bit and + + + align:start position:0% +and increase the temperature a bit and +then you get over to the vapor end of + + align:start position:0% +then you get over to the vapor end of + + + align:start position:0% +then you get over to the vapor end of +the world and then you're left with this + + align:start position:0% +the world and then you're left with this + + + align:start position:0% +the world and then you're left with this +porous + + align:start position:0% +porous + + + align:start position:0% +porous +scaffold um and then let me see let me + + align:start position:0% +scaffold um and then let me see let me + + + align:start position:0% +scaffold um and then let me see let me +do one more step here and then you can + + align:start position:0% +do one more step here and then you can + + + align:start position:0% +do one more step here and then you can +control the size of the pores by + + align:start position:0% +control the size of the pores by + + + align:start position:0% +control the size of the pores by +controlling the freezing temperature so + + align:start position:0% +controlling the freezing temperature so + + + align:start position:0% +controlling the freezing temperature so +the the size of the pores is exactly + + align:start position:0% +the the size of the pores is exactly + + + align:start position:0% +the the size of the pores is exactly +related to the size of the ice grains + + align:start position:0% +related to the size of the ice grains + + + align:start position:0% +related to the size of the ice grains +that are forming and the fast fter it + + align:start position:0% +that are forming and the fast fter it + + + align:start position:0% +that are forming and the fast fter it +freezes the smaller the grains are going + + align:start position:0% +freezes the smaller the grains are going + + + align:start position:0% +freezes the smaller the grains are going +to be and then the smaller your pore + + align:start position:0% +to be and then the smaller your pore + + + align:start position:0% +to be and then the smaller your pore +size are going to be so you can control + + align:start position:0% +size are going to be so you can control + + + align:start position:0% +size are going to be so you can control +that + + align:start position:0% + + + + align:start position:0% + +okay so the type one collagen is mixed + + align:start position:0% +okay so the type one collagen is mixed + + + align:start position:0% +okay so the type one collagen is mixed +with acetic + + align:start position:0% + + + + align:start position:0% + +acid and it then swells the collagen + + align:start position:0% +acid and it then swells the collagen + + + align:start position:0% +acid and it then swells the collagen +and disrupts this periodic + + align:start position:0% + + + + align:start position:0% + +banding and it removes immunological + + align:start position:0% + + + + align:start position:0% + +markers immune + + align:start position:0% + + + + align:start position:0% + +and then you add the the gag the krtin 6 + + align:start position:0% +and then you add the the gag the krtin 6 + + + align:start position:0% +and then you add the the gag the krtin 6 +sulfate + + align:start position:0% + + + + align:start position:0% + +and then that cross links with the + + align:start position:0% +and then that cross links with the + + + align:start position:0% +and then that cross links with the +collagen and forms a + + align:start position:0% + + + + align:start position:0% + +co-precipitate and then you can freeze + + align:start position:0% +co-precipitate and then you can freeze + + + align:start position:0% +co-precipitate and then you can freeze +dry that to get the porous scaffold + + align:start position:0% + + + + align:start position:0% + +and typically the relative densities of + + align:start position:0% +and typically the relative densities of + + + align:start position:0% +and typically the relative densities of +these scaffolds is very + + align:start position:0% +these scaffolds is very + + + align:start position:0% +these scaffolds is very +low so typically they're 05% dense the + + align:start position:0% +low so typically they're 05% dense the + + + align:start position:0% +low so typically they're 05% dense the +relative density is 0.05 so they're + + align:start position:0% +relative density is 0.05 so they're + + + align:start position:0% +relative density is 0.05 so they're +99.5% air and the rest of it's the + + align:start position:0% +99.5% air and the rest of it's the + + + align:start position:0% +99.5% air and the rest of it's the +collagen and the gag and the pore sizes + + align:start position:0% +collagen and the gag and the pore sizes + + + align:start position:0% +collagen and the gag and the pore sizes +are + + align:start position:0% +are + + + align:start position:0% +are +typically between about 100 150 + + align:start position:0% + + + + align:start position:0% + +microns and yanos uses the same + + align:start position:0% +microns and yanos uses the same + + + align:start position:0% +microns and yanos uses the same +scaffolds for the nerve regeneration and + + align:start position:0% +scaffolds for the nerve regeneration and + + + align:start position:0% +scaffolds for the nerve regeneration and +he uses a directional Cooling and that + + align:start position:0% +he uses a directional Cooling and that + + + align:start position:0% +he uses a directional Cooling and that +then elongates the pores so that the the + + align:start position:0% +then elongates the pores so that the the + + + align:start position:0% +then elongates the pores so that the the +ideas that they elongate so the nerves + + align:start position:0% +ideas that they elongate so the nerves + + + align:start position:0% +ideas that they elongate so the nerves +kind of grow along that length + + align:start position:0% + + + + align:start position:0% + +so that's one way another + + align:start position:0% +so that's one way another + + + align:start position:0% +so that's one way another +way is leeching a f fugitive + + align:start position:0% + + + + align:start position:0% + +phase so let's see I + + align:start position:0% +phase so let's see I + + + align:start position:0% +phase so let's see I +think here we go back to there so if you + + align:start position:0% +think here we go back to there so if you + + + align:start position:0% +think here we go back to there so if you +look at the the one on the second row on + + align:start position:0% +look at the the one on the second row on + + + align:start position:0% +look at the the one on the second row on +the left that's done by using salt as + + align:start position:0% +the left that's done by using salt as + + + align:start position:0% +the left that's done by using salt as +The Fugitive phase people use other + + align:start position:0% +The Fugitive phase people use other + + + align:start position:0% +The Fugitive phase people use other +things you can use wax par paraffin wax + + align:start position:0% +things you can use wax par paraffin wax + + + align:start position:0% +things you can use wax par paraffin wax +works as well uh so it doesn't have to + + align:start position:0% +works as well uh so it doesn't have to + + + align:start position:0% +works as well uh so it doesn't have to +be salt there's different things you can + + align:start position:0% +be salt there's different things you can + + + align:start position:0% +be salt there's different things you can +use + + align:start position:0% + + + + align:start position:0% + +so you combine a powder of the polymer + + align:start position:0% +so you combine a powder of the polymer + + + align:start position:0% +so you combine a powder of the polymer +with your fugitive phase say + + align:start position:0% + + + + align:start position:0% + +salt then you heat it up to get the + + align:start position:0% +salt then you heat it up to get the + + + align:start position:0% +salt then you heat it up to get the +polymer to + + align:start position:0% +polymer to + + + align:start position:0% +polymer to +bind and then you leech out the salt + + align:start position:0% + + + + align:start position:0% + +so you can control the paracity by the + + align:start position:0% +so you can control the paracity by the + + + align:start position:0% +so you can control the paracity by the +volume fraction of the fugitive phase + + align:start position:0% +volume fraction of the fugitive phase + + + align:start position:0% +volume fraction of the fugitive phase +and then the pore size by the size of + + align:start position:0% +and then the pore size by the size of + + + align:start position:0% +and then the pore size by the size of +whatever The Fugitive phase is + + align:start position:0% + + + + align:start position:0% + +so another technique is electr spinning + + align:start position:0% +so another technique is electr spinning + + + align:start position:0% +so another technique is electr spinning +the idea is you produce fibers uh from a + + align:start position:0% +the idea is you produce fibers uh from a + + + align:start position:0% +the idea is you produce fibers uh from a +polymer solution that you extrude + + align:start position:0% +polymer solution that you extrude + + + align:start position:0% +polymer solution that you extrude +through a nozzle and then you apply a + + align:start position:0% +through a nozzle and then you apply a + + + align:start position:0% +through a nozzle and then you apply a +voltage uh across some plates to spin + + align:start position:0% +voltage uh across some plates to spin + + + align:start position:0% +voltage uh across some plates to spin +the fibers + + align:start position:0% + + + + align:start position:0% + +and then you get a + + align:start position:0% +and then you get a + + + align:start position:0% +and then you get a +network of these fibers and typically + + align:start position:0% +network of these fibers and typically + + + align:start position:0% +network of these fibers and typically +they're Micron scale diameter + + align:start position:0% + + + + align:start position:0% + +and the last method I'm going to talk + + align:start position:0% +and the last method I'm going to talk + + + align:start position:0% +and the last method I'm going to talk +about is rapid prototyping so you could + + align:start position:0% +about is rapid prototyping so you could + + + align:start position:0% +about is rapid prototyping so you could +think of using 3D printing or you could + + align:start position:0% +think of using 3D printing or you could + + + align:start position:0% +think of using 3D printing or you could +use um selective laser centering or + + align:start position:0% +use um selective laser centering or + + + align:start position:0% +use um selective laser centering or +stereol lithography using a + + align:start position:0% +stereol lithography using a + + + align:start position:0% +stereol lithography using a +photosensitive sensitive polymer so the + + align:start position:0% +photosensitive sensitive polymer so the + + + align:start position:0% +photosensitive sensitive polymer so the +idea is you you know how this works you + + align:start position:0% +idea is you you know how this works you + + + align:start position:0% +idea is you you know how this works you +just build up layers um of solid one + + align:start position:0% +just build up layers um of solid one + + + align:start position:0% +just build up layers um of solid one +layer at a time + + align:start position:0% + + + + align:start position:0% + +and then you can make complex geometries + + align:start position:0% +and then you can make complex geometries + + + align:start position:0% +and then you can make complex geometries +with that so that's one of the + + align:start position:0% + + + + align:start position:0% + +advantages so if you wanted to make a + + align:start position:0% +advantages so if you wanted to make a + + + align:start position:0% +advantages so if you wanted to make a +part to fit you know a particular place + + align:start position:0% +part to fit you know a particular place + + + align:start position:0% +part to fit you know a particular place +in the tissue then it's it's convenient + + align:start position:0% +in the tissue then it's it's convenient + + + align:start position:0% +in the tissue then it's it's convenient +that you can control the geometry of the + + align:start position:0% +that you can control the geometry of the + + + align:start position:0% +that you can control the geometry of the +whole + + align:start position:0% + + + + align:start position:0% + +part for + + align:start position:0% + + + + align:start position:0% + +okay so that just kind of summarizes + + align:start position:0% +okay so that just kind of summarizes + + + align:start position:0% +okay so that just kind of summarizes +very briefly kind of how the tissue + + align:start position:0% +very briefly kind of how the tissue + + + align:start position:0% +very briefly kind of how the tissue +engineering scaffolds are meant to work + + align:start position:0% +engineering scaffolds are meant to work + + + align:start position:0% +engineering scaffolds are meant to work +what kinds of materials people make them + + align:start position:0% +what kinds of materials people make them + + + align:start position:0% +what kinds of materials people make them +from and a few of the processes and + + align:start position:0% +from and a few of the processes and + + + align:start position:0% +from and a few of the processes and +there there's many many processes these + + align:start position:0% +there there's many many processes these + + + align:start position:0% +there there's many many processes these +are just sort of a few common processes + + align:start position:0% +are just sort of a few common processes + + + align:start position:0% +are just sort of a few common processes +I wanted to talk a little bit about the + + align:start position:0% +I wanted to talk a little bit about the + + + align:start position:0% +I wanted to talk a little bit about the +mechanical Behavior because that's kind + + align:start position:0% +mechanical Behavior because that's kind + + + align:start position:0% +mechanical Behavior because that's kind +of what I do uh and so this next plot + + align:start position:0% +of what I do uh and so this next plot + + + align:start position:0% +of what I do uh and so this next plot +just shows a stress strain curve in + + align:start position:0% +just shows a stress strain curve in + + + align:start position:0% +just shows a stress strain curve in +compression for a collagen gag scaffold + + align:start position:0% +compression for a collagen gag scaffold + + + align:start position:0% +compression for a collagen gag scaffold +and I'm hoping that by now you're + + align:start position:0% +and I'm hoping that by now you're + + + align:start position:0% +and I'm hoping that by now you're +getting the idea all of these cellular + + align:start position:0% +getting the idea all of these cellular + + + align:start position:0% +getting the idea all of these cellular +materials have this kind of shape of a + + align:start position:0% +materials have this kind of shape of a + + + align:start position:0% +materials have this kind of shape of a +curve so there's the same kind of linear + + align:start position:0% +curve so there's the same kind of linear + + + align:start position:0% +curve so there's the same kind of linear +elastic regime and then a collapsed + + align:start position:0% +elastic regime and then a collapsed + + + align:start position:0% +elastic regime and then a collapsed +Plateau these collagen things as you can + + align:start position:0% +Plateau these collagen things as you can + + + align:start position:0% +Plateau these collagen things as you can +imagine just pressing them in your hand + + align:start position:0% +imagine just pressing them in your hand + + + align:start position:0% +imagine just pressing them in your hand +they fail by buckling by an elastic + + align:start position:0% +they fail by buckling by an elastic + + + align:start position:0% +they fail by buckling by an elastic +buckling and then there's a + + align:start position:0% +buckling and then there's a + + + align:start position:0% +buckling and then there's a +densification regime so they look like + + align:start position:0% +densification regime so they look like + + + align:start position:0% +densification regime so they look like +all the other kinds of curves that we've + + align:start position:0% +all the other kinds of curves that we've + + + align:start position:0% +all the other kinds of curves that we've +got um one of the things we've done in + + align:start position:0% +got um one of the things we've done in + + + align:start position:0% +got um one of the things we've done in +the modeling is typically in the model + + align:start position:0% +the modeling is typically in the model + + + align:start position:0% +the modeling is typically in the model +we want to be able to calculate or + + align:start position:0% +we want to be able to calculate or + + + align:start position:0% +we want to be able to calculate or +measure the uh modulus of the solid or + + align:start position:0% +measure the uh modulus of the solid or + + + align:start position:0% +measure the uh modulus of the solid or +the strength of the solid from which the + + align:start position:0% +the strength of the solid from which the + + + align:start position:0% +the strength of the solid from which the +things made so Brendan Harley was one of + + align:start position:0% +things made so Brendan Harley was one of + + + align:start position:0% +things made so Brendan Harley was one of +my PhD students uh and he took a little + + align:start position:0% +my PhD students uh and he took a little + + + align:start position:0% +my PhD students uh and he took a little +microscope cut a little strut the struts + + align:start position:0% +microscope cut a little strut the struts + + + align:start position:0% +microscope cut a little strut the struts +are very small right the pore size is + + align:start position:0% +are very small right the pore size is + + + align:start position:0% +are very small right the pore size is +100 Micron so the struts are you know on + + align:start position:0% +100 Micron so the struts are you know on + + + align:start position:0% +100 Micron so the struts are you know on +that order uh he glued one end of the + + align:start position:0% +that order uh he glued one end of the + + + align:start position:0% +that order uh he glued one end of the +strut to a glass slide and then he used + + align:start position:0% +strut to a glass slide and then he used + + + align:start position:0% +strut to a glass slide and then he used +an AFM probe to do a little bending test + + align:start position:0% +an AFM probe to do a little bending test + + + align:start position:0% +an AFM probe to do a little bending test +on that little strut and so he could + + align:start position:0% +on that little strut and so he could + + + align:start position:0% +on that little strut and so he could +measure you know if he could measure the + + align:start position:0% +measure you know if he could measure the + + + align:start position:0% +measure you know if he could measure the +deflection he knew the length he knew + + align:start position:0% +deflection he knew the length he knew + + + align:start position:0% +deflection he knew the length he knew +the geometry of the strut he could + + align:start position:0% +the geometry of the strut he could + + + align:start position:0% +the geometry of the strut he could +figure out what the modulus was for the + + align:start position:0% +figure out what the modulus was for the + + + align:start position:0% +figure out what the modulus was for the +solid so he backs out what the modulus + + align:start position:0% +solid so he backs out what the modulus + + + align:start position:0% +solid so he backs out what the modulus +is so he did these measurements on a dry + + align:start position:0% +is so he did these measurements on a dry + + + align:start position:0% +is so he did these measurements on a dry +strut and then by comparing the um + + align:start position:0% +strut and then by comparing the um + + + align:start position:0% +strut and then by comparing the um +overall modulus of a dry scaffold with a + + align:start position:0% +overall modulus of a dry scaffold with a + + + align:start position:0% +overall modulus of a dry scaffold with a +wet scaffold he estimated what the + + align:start position:0% +wet scaffold he estimated what the + + + align:start position:0% +wet scaffold he estimated what the +modulus of the wet scaffold or the wet + + align:start position:0% +modulus of the wet scaffold or the wet + + + align:start position:0% +modulus of the wet scaffold or the wet +strut would be so the modulus of the dry + + align:start position:0% +strut would be so the modulus of the dry + + + align:start position:0% +strut would be so the modulus of the dry +collagen gag was 672 megap Pascal it's a + + align:start position:0% +collagen gag was 672 megap Pascal it's a + + + align:start position:0% +collagen gag was 672 megap Pascal it's a +little less than a gigap pascal and wet + + align:start position:0% +little less than a gigap pascal and wet + + + align:start position:0% +little less than a gigap pascal and wet +it was about five so it's there's a huge + + align:start position:0% +it was about five so it's there's a huge + + + align:start position:0% +it was about five so it's there's a huge +difference between the wet and the + + align:start position:0% +difference between the wet and the + + + align:start position:0% +difference between the wet and the +dry okay so let me uh let me just write + + align:start position:0% +dry okay so let me uh let me just write + + + align:start position:0% +dry okay so let me uh let me just write +a few notes about that + + align:start position:0% + + + + align:start position:0% + +so in compression there's the three + + align:start position:0% +so in compression there's the three + + + align:start position:0% +so in compression there's the three +regimes that we see for all these + + align:start position:0% +regimes that we see for all these + + + align:start position:0% +regimes that we see for all these +cellular + + align:start position:0% + + + + align:start position:0% + +materials and so you can estimate the + + align:start position:0% +materials and so you can estimate the + + + align:start position:0% +materials and so you can estimate the +modulus by using the model we have for + + align:start position:0% +modulus by using the model we have for + + + align:start position:0% +modulus by using the model we have for +the foam for the modulus the modulus of + + align:start position:0% +the foam for the modulus the modulus of + + + align:start position:0% +the foam for the modulus the modulus of +the foam divided by the modulus of the + + align:start position:0% +the foam divided by the modulus of the + + + align:start position:0% +the foam divided by the modulus of the +solid goes as the relative density + + align:start position:0% +solid goes as the relative density + + + align:start position:0% +solid goes as the relative density +squared and that's related to bending in + + align:start position:0% +squared and that's related to bending in + + + align:start position:0% +squared and that's related to bending in +the cell + + align:start position:0% +the cell + + + align:start position:0% +the cell +wall and then the collapse Plateau is + + align:start position:0% +wall and then the collapse Plateau is + + + align:start position:0% +wall and then the collapse Plateau is +related to elastic buckling and so + + align:start position:0% +related to elastic buckling and so + + + align:start position:0% +related to elastic buckling and so +that's equal to some constant * e of the + + align:start position:0% +that's equal to some constant * e of the + + + align:start position:0% +that's equal to some constant * e of the +solid time the relative density squared + + align:start position:0% +solid time the relative density squared + + + align:start position:0% +solid time the relative density squared +and that's related to elastic + + align:start position:0% + + + + align:start position:0% + +buckling and then we measured e of the + + align:start position:0% +buckling and then we measured e of the + + + align:start position:0% +buckling and then we measured e of the +solid doing this little AFM uh beam + + align:start position:0% +solid doing this little AFM uh beam + + + align:start position:0% +solid doing this little AFM uh beam +bending test + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +okay and for one of these low density + + align:start position:0% +okay and for one of these low density + + + align:start position:0% +okay and for one of these low density +scaffold folds uh we measured the + + align:start position:0% +scaffold folds uh we measured the + + + align:start position:0% +scaffold folds uh we measured the +modulus we measured the buckling + + align:start position:0% +modulus we measured the buckling + + + align:start position:0% +modulus we measured the buckling +strength and we got pretty good + + align:start position:0% +strength and we got pretty good + + + align:start position:0% +strength and we got pretty good +agreement by using these equations here + + align:start position:0% +agreement by using these equations here + + + align:start position:0% +agreement by using these equations here +and uh the good + + align:start position:0% +and uh the good + + + align:start position:0% +and uh the good +agreement was if this constant was 0 2 + + align:start position:0% +agreement was if this constant was 0 2 + + + align:start position:0% +agreement was if this constant was 0 2 +that was the strain at buckling yeah so + + align:start position:0% +that was the strain at buckling yeah so + + + align:start position:0% +that was the strain at buckling yeah so +what does it mean to be like wet here + + align:start position:0% +what does it mean to be like wet here + + + align:start position:0% +what does it mean to be like wet here +and and uh like why is it so much lower + + align:start position:0% +and and uh like why is it so much lower + + + align:start position:0% +and and uh like why is it so much lower +um well we can you know we make the + + align:start position:0% +um well we can you know we make the + + + align:start position:0% +um well we can you know we make the +scaffolds by this freeze drying thing + + align:start position:0% +scaffolds by this freeze drying thing + + + align:start position:0% +scaffolds by this freeze drying thing +and like this thing I passed around that + + align:start position:0% +and like this thing I passed around that + + + align:start position:0% +and like this thing I passed around that +was dry right we just immerse it in + + align:start position:0% +was dry right we just immerse it in + + + align:start position:0% +was dry right we just immerse it in +water we just put it in water and then + + align:start position:0% +water we just put it in water and then + + + align:start position:0% +water we just put it in water and then +we he does the test um you know so he + + align:start position:0% +we he does the test um you know so he + + + align:start position:0% +we he does the test um you know so he +does the test on the whole scaffold dry + + align:start position:0% +does the test on the whole scaffold dry + + + align:start position:0% +does the test on the whole scaffold dry +and then he does the test on the whole + + align:start position:0% +and then he does the test on the whole + + + align:start position:0% +and then he does the test on the whole +scaffold wet and I assume there's some + + align:start position:0% +scaffold wet and I assume there's some + + + align:start position:0% +scaffold wet and I assume there's some +sort of bonding that gets disrupted by + + align:start position:0% +sort of bonding that gets disrupted by + + + align:start position:0% +sort of bonding that gets disrupted by +having the water I don't know the + + align:start position:0% +having the water I don't know the + + + align:start position:0% +having the water I don't know the +details of how that works but there must + + align:start position:0% +details of how that works but there must + + + align:start position:0% +details of how that works but there must +be some change in the bonding to make + + align:start position:0% +be some change in the bonding to make + + + align:start position:0% +be some change in the bonding to make +that + + align:start position:0% +that + + + align:start position:0% +that +happen um so let's see I'm trying to see + + align:start position:0% +happen um so let's see I'm trying to see + + + align:start position:0% +happen um so let's see I'm trying to see +what else should we do today oh yeah + + align:start position:0% +what else should we do today oh yeah + + + align:start position:0% +what else should we do today oh yeah +so um so we get pretty good agreement + + align:start position:0% +so um so we get pretty good agreement + + + align:start position:0% +so um so we get pretty good agreement +with this sort of simple foamy model one + + align:start position:0% +with this sort of simple foamy model one + + + align:start position:0% +with this sort of simple foamy model one +of the things we did find was that when + + align:start position:0% +of the things we did find was that when + + + align:start position:0% +of the things we did find was that when +we tested higher density scaffolds the + + align:start position:0% +we tested higher density scaffolds the + + + align:start position:0% +we tested higher density scaffolds the +agreement wasn't so good and I think + + align:start position:0% +agreement wasn't so good and I think + + + align:start position:0% +agreement wasn't so good and I think +this was because when you get higher + + align:start position:0% +this was because when you get higher + + + align:start position:0% +this was because when you get higher +density it's just hard to get the + + align:start position:0% +density it's just hard to get the + + + align:start position:0% +density it's just hard to get the +collagen gag mixture to mix in with the + + align:start position:0% +collagen gag mixture to mix in with the + + + align:start position:0% +collagen gag mixture to mix in with the +acetic acid so we ended up getting + + align:start position:0% +acetic acid so we ended up getting + + + align:start position:0% +acetic acid so we ended up getting +inhomogeneous scaffolds with sort of + + align:start position:0% +inhomogeneous scaffolds with sort of + + + align:start position:0% +inhomogeneous scaffolds with sort of +large voids in them so in order for the + + align:start position:0% +large voids in them so in order for the + + + align:start position:0% +large voids in them so in order for the +modeling to work you have to have a + + align:start position:0% +modeling to work you have to have a + + + align:start position:0% +modeling to work you have to have a +scaffold that's relatively homogeneous + + align:start position:0% +scaffold that's relatively homogeneous + + + align:start position:0% +scaffold that's relatively homogeneous +you don't have kind of big defects in it + + align:start position:0% +you don't have kind of big defects in it + + + align:start position:0% +you don't have kind of big defects in it +um so I think that's all I'm going to + + align:start position:0% +um so I think that's all I'm going to + + + align:start position:0% +um so I think that's all I'm going to +say about that + + align:start position:0% +say about that + + + align:start position:0% +say about that +I have one more slide + + align:start position:0% +I have one more slide + + + align:start position:0% +I have one more slide +here um so those are sort of + + align:start position:0% +here um so those are sort of + + + align:start position:0% +here um so those are sort of +three-dimensional scaffolds we've been + + align:start position:0% +three-dimensional scaffolds we've been + + + align:start position:0% +three-dimensional scaffolds we've been +talking about sort of foam like + + align:start position:0% +talking about sort of foam like + + + align:start position:0% +talking about sort of foam like +scaffolds people have also made + + align:start position:0% +scaffolds people have also made + + + align:start position:0% +scaffolds people have also made +honeycomb like scaffolds as well and + + align:start position:0% +honeycomb like scaffolds as well and + + + align:start position:0% +honeycomb like scaffolds as well and +this just shows some examples of some + + align:start position:0% +this just shows some examples of some + + + align:start position:0% +this just shows some examples of some +honeycomb type + + align:start position:0% +honeycomb type + + + align:start position:0% +honeycomb type +scaffolds so uh this one here I think + + align:start position:0% +scaffolds so uh this one here I think + + + align:start position:0% +scaffolds so uh this one here I think +was made in s bia's lab it's sort of you + + align:start position:0% +was made in s bia's lab it's sort of you + + + align:start position:0% +was made in s bia's lab it's sort of you +can sort of think of it as a hexagon but + + align:start position:0% +can sort of think of it as a hexagon but + + + align:start position:0% +can sort of think of it as a hexagon but +it's also kind of triangulated as well + + align:start position:0% +it's also kind of triangulated as well + + + align:start position:0% +it's also kind of triangulated as well +uh these two here were made by George + + align:start position:0% +uh these two here were made by George + + + align:start position:0% +uh these two here were made by George +Angel he worked with Bob Langer at one + + align:start position:0% +Angel he worked with Bob Langer at one + + + align:start position:0% +Angel he worked with Bob Langer at one +point and they were these two scaffolds + + align:start position:0% +point and they were these two scaffolds + + + align:start position:0% +point and they were these two scaffolds +here you know they're both sort of + + align:start position:0% +here you know they're both sort of + + + align:start position:0% +here you know they're both sort of +rectangular cells uh and they were + + align:start position:0% +rectangular cells uh and they were + + + align:start position:0% +rectangular cells uh and they were +designed to look at how the cell + + align:start position:0% +designed to look at how the cell + + + align:start position:0% +designed to look at how the cell +geometry or the pore geometry affected + + align:start position:0% +geometry or the pore geometry affected + + + align:start position:0% +geometry or the pore geometry affected +the sort of morphology of the cells that + + align:start position:0% +the sort of morphology of the cells that + + + align:start position:0% +the sort of morphology of the cells that +attached so if you have different shaped + + align:start position:0% +attached so if you have different shaped + + + align:start position:0% +attached so if you have different shaped +porest you get different morphology in + + align:start position:0% +porest you get different morphology in + + + align:start position:0% +porest you get different morphology in +the cells that you're trying to attach + + align:start position:0% +the cells that you're trying to attach + + + align:start position:0% +the cells that you're trying to attach +and then George engelm also made these + + align:start position:0% +and then George engelm also made these + + + align:start position:0% +and then George engelm also made these +scaffolds here uh and those were + + align:start position:0% +scaffolds here uh and those were + + + align:start position:0% +scaffolds here uh and those were +designed to be anisotropic and have + + align:start position:0% +designed to be anisotropic and have + + + align:start position:0% +designed to be anisotropic and have +different mechanical properties in + + align:start position:0% +different mechanical properties in + + + align:start position:0% +different mechanical properties in +different directions + + align:start position:0% +different directions + + + align:start position:0% +different directions +and I think what they had done was try + + align:start position:0% +and I think what they had done was try + + + align:start position:0% +and I think what they had done was try +to match the anisotropy and the + + align:start position:0% +to match the anisotropy and the + + + align:start position:0% +to match the anisotropy and the +mechanical properties to anisotropy and + + align:start position:0% +mechanical properties to anisotropy and + + + align:start position:0% +mechanical properties to anisotropy and +heart tissue and cardiac tissue so these + + align:start position:0% +heart tissue and cardiac tissue so these + + + align:start position:0% +heart tissue and cardiac tissue so these +are some examples of honeycomb type + + align:start position:0% +are some examples of honeycomb type + + + align:start position:0% +are some examples of honeycomb type +scaffolds so let me just write down a + + align:start position:0% +scaffolds so let me just write down a + + + align:start position:0% +scaffolds so let me just write down a +few things about those + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +so I think these were + + align:start position:0% +so I think these were + + + align:start position:0% +so I think these were +more sometimes you know obviously the + + align:start position:0% +more sometimes you know obviously the + + + align:start position:0% +more sometimes you know obviously the +scaffolds are used the ultimate goal is + + align:start position:0% +scaffolds are used the ultimate goal is + + + align:start position:0% +scaffolds are used the ultimate goal is +to use them clinically but sometimes + + align:start position:0% +to use them clinically but sometimes + + + align:start position:0% +to use them clinically but sometimes +people make scaffolds just to study cell + + align:start position:0% +people make scaffolds just to study cell + + + align:start position:0% +people make scaffolds just to study cell +behavior and some of these I think were + + align:start position:0% +behavior and some of these I think were + + + align:start position:0% +behavior and some of these I think were +made just to study how the cells would + + align:start position:0% +made just to study how the cells would + + + align:start position:0% +made just to study how the cells would +behave on them so they're sort of IDE + + align:start position:0% +behave on them so they're sort of IDE + + + align:start position:0% +behave on them so they're sort of IDE +realized to do + + align:start position:0% + + + + align:start position:0% + +that so that triangulated kind of looks + + align:start position:0% +that so that triangulated kind of looks + + + align:start position:0% +that so that triangulated kind of looks +like a hexagon but there also sort of + + align:start position:0% +like a hexagon but there also sort of + + + align:start position:0% +like a hexagon but there also sort of +triangles in + + align:start position:0% + + + + align:start position:0% + +there I think the thing they were + + align:start position:0% +there I think the thing they were + + + align:start position:0% +there I think the thing they were +looking at with that was the uh was + + align:start position:0% +looking at with that was the uh was + + + align:start position:0% +looking at with that was the uh was +transport of nutrients to cells um + + align:start position:0% + + + + align:start position:0% + +and from a mechanical point of view if + + align:start position:0% +and from a mechanical point of view if + + + align:start position:0% +and from a mechanical point of view if +it's triangulated you'd expect say the + + align:start position:0% +it's triangulated you'd expect say the + + + align:start position:0% +it's triangulated you'd expect say the +modulus of that to go + + align:start position:0% +modulus of that to go + + + align:start position:0% +modulus of that to go +linearly with how much solid there is + + align:start position:0% + + + + align:start position:0% + +there so the rectangular honeycomb and + + align:start position:0% +there so the rectangular honeycomb and + + + align:start position:0% +there so the rectangular honeycomb and +the diamond shaped pores they were used + + align:start position:0% +the diamond shaped pores they were used + + + align:start position:0% +the diamond shaped pores they were used +to study the effect of pore geometry on + + align:start position:0% +to study the effect of pore geometry on + + + align:start position:0% +to study the effect of pore geometry on +the cell orientation they used fiber + + align:start position:0% +the cell orientation they used fiber + + + align:start position:0% +the cell orientation they used fiber +blasts + + align:start position:0% + + + + align:start position:0% + +and that I'm going to call it the + + align:start position:0% +and that I'm going to call it the + + + align:start position:0% +and that I'm going to call it the +accordion like + + align:start position:0% + + + + align:start position:0% + +honeycomb that's mechanically + + align:start position:0% +honeycomb that's mechanically + + + align:start position:0% +honeycomb that's mechanically +anisotropic and the mechanical an + + align:start position:0% +anisotropic and the mechanical an + + + align:start position:0% +anisotropic and the mechanical an +anisotropy is matched to the cardiac + + align:start position:0% +anisotropy is matched to the cardiac + + + align:start position:0% +anisotropy is matched to the cardiac +tissue + + align:start position:0% + + + + align:start position:0% + +okay so I think I'm going to stop there + + align:start position:0% +okay so I think I'm going to stop there + + + align:start position:0% +okay so I think I'm going to stop there +for today um that's sort of the end of + + align:start position:0% +for today um that's sort of the end of + + + align:start position:0% +for today um that's sort of the end of +this part of it and next time I'm going + + align:start position:0% +this part of it and next time I'm going + + + align:start position:0% +this part of it and next time I'm going +to talk about the osteochondral scaffold + + align:start position:0% +to talk about the osteochondral scaffold + + + align:start position:0% +to talk about the osteochondral scaffold +so I don't think it really makes sense + + align:start position:0% +so I don't think it really makes sense + + + align:start position:0% +so I don't think it really makes sense +to start it for two or three minutes so + + align:start position:0% +to start it for two or three minutes so + + + align:start position:0% +to start it for two or three minutes so +I'll start that tomorrow our wedding day + + align:start position:0% +I'll start that tomorrow our wedding day + + + align:start position:0% +I'll start that tomorrow our wedding day +and we should be able to finish that on + + align:start position:0% +and we should be able to finish that on + + + align:start position:0% +and we should be able to finish that on +weding day so one of the things that the + + align:start position:0% +weding day so one of the things that the + + + align:start position:0% +weding day so one of the things that the +these honeycomb type scaffolds kind of + + align:start position:0% +these honeycomb type scaffolds kind of + + + align:start position:0% +these honeycomb type scaffolds kind of +suggests is that the scaffolds are used + + align:start position:0% +suggests is that the scaffolds are used + + + align:start position:0% +suggests is that the scaffolds are used +both to try to regenerate tissue in the + + align:start position:0% +both to try to regenerate tissue in the + + + align:start position:0% +both to try to regenerate tissue in the +body and clinical applications but + + align:start position:0% +body and clinical applications but + + + align:start position:0% +body and clinical applications but +they're also used as sort of an + + align:start position:0% +they're also used as sort of an + + + align:start position:0% +they're also used as sort of an +environment for cells in order to study + + align:start position:0% +environment for cells in order to study + + + align:start position:0% +environment for cells in order to study +cell Behavior so next time I'm going to + + align:start position:0% +cell Behavior so next time I'm going to + + + align:start position:0% +cell Behavior so next time I'm going to +talk about an osteochondral scaffold and + + align:start position:0% +talk about an osteochondral scaffold and + + + align:start position:0% +talk about an osteochondral scaffold and +the idea with that was to try to use it + + align:start position:0% +the idea with that was to try to use it + + + align:start position:0% +the idea with that was to try to use it +clinically but next week I'm going to + + align:start position:0% +clinically but next week I'm going to + + + align:start position:0% +clinically but next week I'm going to +talk about cell mechanics a bit and when + + align:start position:0% +talk about cell mechanics a bit and when + + + align:start position:0% +talk about cell mechanics a bit and when +people study cell mechanics so we're + + align:start position:0% +people study cell mechanics so we're + + + align:start position:0% +people study cell mechanics so we're +looking at this the mechanics of + + align:start position:0% +looking at this the mechanics of + + + align:start position:0% +looking at this the mechanics of +biological cells not the not the + + align:start position:0% +biological cells not the not the + + + align:start position:0% +biological cells not the not the +cellular structures so when people look + + align:start position:0% +cellular structures so when people look + + + align:start position:0% +cellular structures so when people look +at trying to study how cells behave they + + align:start position:0% +at trying to study how cells behave they + + + align:start position:0% +at trying to study how cells behave they +need some environment to put them on + + align:start position:0% +need some environment to put them on + + + align:start position:0% +need some environment to put them on +typically people started by just using + + align:start position:0% +typically people started by just using + + + align:start position:0% +typically people started by just using +flat 2D substrates but the flat 2D + + align:start position:0% +flat 2D substrates but the flat 2D + + + align:start position:0% +flat 2D substrates but the flat 2D +substrates are kind of easy to study but + + align:start position:0% +substrates are kind of easy to study but + + + align:start position:0% +substrates are kind of easy to study but +they don't really represent the tissue + + align:start position:0% +they don't really represent the tissue + + + align:start position:0% +they don't really represent the tissue +in the body and so people are now using + + align:start position:0% +in the body and so people are now using + + + align:start position:0% +in the body and so people are now using +tissue engineering scaffolds as an + + align:start position:0% +tissue engineering scaffolds as an + + + align:start position:0% +tissue engineering scaffolds as an +environment that they can control to + + align:start position:0% +environment that they can control to + + + align:start position:0% +environment that they can control to +study how cells behave so they study + + align:start position:0% +study how cells behave so they study + + + align:start position:0% +study how cells behave so they study +cell attachment cell proliferation cell + + align:start position:0% +cell attachment cell proliferation cell + + + align:start position:0% +cell attachment cell proliferation cell +migration and cell differentiation all + + align:start position:0% +migration and cell differentiation all + + + align:start position:0% +migration and cell differentiation all +by using the scaffolds as kind of a + + align:start position:0% +by using the scaffolds as kind of a + + + align:start position:0% +by using the scaffolds as kind of a +controlled environment so we'll talk + + align:start position:0% +controlled environment so we'll talk + + + align:start position:0% +controlled environment so we'll talk +talk about that probably not I don't + + align:start position:0% +talk about that probably not I don't + + + align:start position:0% +talk about that probably not I don't +know if we'll get to it on Wednesday but + + align:start position:0% +know if we'll get to it on Wednesday but + + + align:start position:0% +know if we'll get to it on Wednesday but +we'll we might start it on Wednesday and + + align:start position:0% +we'll we might start it on Wednesday and + + + align:start position:0% +we'll we might start it on Wednesday and +finish it next week okay \ No newline at end of file diff --git a/U_sZrNjbj1I.txt b/U_sZrNjbj1I.txt new file mode 100644 index 0000000000000000000000000000000000000000..f47c48ead8b6801c8c25b46c3a12321f4f214b81 --- /dev/null +++ b/U_sZrNjbj1I.txt @@ -0,0 +1,1411 @@ +align:start position:0% + +good morning Board of Directors as all + + align:start position:0% +good morning Board of Directors as all + + + align:start position:0% +good morning Board of Directors as all +of you know from 2002 to 2007 the u.s. + + align:start position:0% +of you know from 2002 to 2007 the u.s. + + + align:start position:0% +of you know from 2002 to 2007 the u.s. +lost 4 million acres agricultural land + + align:start position:0% +lost 4 million acres agricultural land + + + align:start position:0% +lost 4 million acres agricultural land +development and area nearly the size of + + align:start position:0% +development and area nearly the size of + + + align:start position:0% +development and area nearly the size of +Massachusetts and although there are + + align:start position:0% +Massachusetts and although there are + + + align:start position:0% +Massachusetts and although there are +federal policies targeted to combat this + + align:start position:0% +federal policies targeted to combat this + + + align:start position:0% +federal policies targeted to combat this +loss of farmland they are not nearly + + align:start position:0% +loss of farmland they are not nearly + + + align:start position:0% +loss of farmland they are not nearly +enough to deal with this problem we have + + align:start position:0% +enough to deal with this problem we have + + + align:start position:0% +enough to deal with this problem we have +here at home and so I'll speak about + + align:start position:0% +here at home and so I'll speak about + + + align:start position:0% +here at home and so I'll speak about +three things today firstly what I intend + + align:start position:0% +three things today firstly what I intend + + + align:start position:0% +three things today firstly what I intend +to find out for my upcoming trips to + + align:start position:0% +to find out for my upcoming trips to + + + align:start position:0% +to find out for my upcoming trips to +yield Japan Australia who I intend to + + align:start position:0% +yield Japan Australia who I intend to + + + align:start position:0% +yield Japan Australia who I intend to +find out this information from secondly + + align:start position:0% +find out this information from secondly + + + align:start position:0% +find out this information from secondly +what opportunities I see in these strips + + align:start position:0% +what opportunities I see in these strips + + + align:start position:0% +what opportunities I see in these strips +for cross contextual learning and + + align:start position:0% +for cross contextual learning and + + + align:start position:0% +for cross contextual learning and +thirdly what challenges anticipate + + align:start position:0% +thirdly what challenges anticipate + + + align:start position:0% +thirdly what challenges anticipate +translating this learning to ideas and + + align:start position:0% +translating this learning to ideas and + + + align:start position:0% +translating this learning to ideas and +strategies that are really useful for us + + align:start position:0% +strategies that are really useful for us + + + align:start position:0% +strategies that are really useful for us +here in the US so firstly in these + + align:start position:0% +here in the US so firstly in these + + + align:start position:0% +here in the US so firstly in these +regions we intend to focus on three + + align:start position:0% +regions we intend to focus on three + + + align:start position:0% +regions we intend to focus on three +critical issues drawn from the problems + + align:start position:0% +critical issues drawn from the problems + + + align:start position:0% +critical issues drawn from the problems +here at home we term them the three P's + + align:start position:0% +here at home we term them the three P's + + + align:start position:0% +here at home we term them the three P's +place policies and people so firstly + + align:start position:0% +place policies and people so firstly + + + align:start position:0% +place policies and people so firstly +this very strong geographical notion of + + align:start position:0% +this very strong geographical notion of + + + align:start position:0% +this very strong geographical notion of +place and a better for it the u.s. is + + align:start position:0% +place and a better for it the u.s. is + + + align:start position:0% +place and a better for it the u.s. is +losing its finest land to development + + align:start position:0% +losing its finest land to development + + + align:start position:0% +losing its finest land to development +and we want to find out in these regions + + align:start position:0% +and we want to find out in these regions + + + align:start position:0% +and we want to find out in these regions +how they view the trade-off between + + align:start position:0% +how they view the trade-off between + + + align:start position:0% +how they view the trade-off between +development and found land protection or + + align:start position:0% +development and found land protection or + + + align:start position:0% +development and found land protection or +if it even exists for them in the first + + align:start position:0% +if it even exists for them in the first + + + align:start position:0% +if it even exists for them in the first +place secondly we want to find out what + + align:start position:0% +place secondly we want to find out what + + + align:start position:0% +place secondly we want to find out what +policies these regions have to combat + + align:start position:0% +policies these regions have to combat + + + align:start position:0% +policies these regions have to combat +the development of farmland into other + + align:start position:0% +the development of farmland into other + + + align:start position:0% +the development of farmland into other +users and the impact of the format's and + + align:start position:0% +users and the impact of the format's and + + + align:start position:0% +users and the impact of the format's and +thirdly the people we want to find out + + align:start position:0% +thirdly the people we want to find out + + + align:start position:0% +thirdly the people we want to find out +the cultural institutions and cultural + + align:start position:0% +the cultural institutions and cultural + + + align:start position:0% +the cultural institutions and cultural +mindset stamp addressing places and + + align:start position:0% +mindset stamp addressing places and + + + align:start position:0% +mindset stamp addressing places and +policies essentially what the + + align:start position:0% +policies essentially what the + + + align:start position:0% +policies essentially what the +stakeholders of these farming + + align:start position:0% +stakeholders of these farming + + + align:start position:0% +stakeholders of these farming +communities are responding to the + + align:start position:0% +communities are responding to the + + + align:start position:0% +communities are responding to the +policies that have been developed so who + + align:start position:0% +policies that have been developed so who + + + align:start position:0% +policies that have been developed so who +do we intend to find out this + + align:start position:0% +do we intend to find out this + + + align:start position:0% +do we intend to find out this +information from we intend to look for + + align:start position:0% +information from we intend to look for + + + align:start position:0% +information from we intend to look for +stakeholders and business industry that + + align:start position:0% +stakeholders and business industry that + + + align:start position:0% +stakeholders and business industry that +are driving the interaction between farm + + align:start position:0% +are driving the interaction between farm + + + align:start position:0% +are driving the interaction between farm +land and development and they were + + align:start position:0% +land and development and they were + + + align:start position:0% +land and development and they were +inform us most about the issues of + + align:start position:0% +inform us most about the issues of + + + align:start position:0% +inform us most about the issues of +please we also intend to look to talk to + + align:start position:0% +please we also intend to look to talk to + + + align:start position:0% +please we also intend to look to talk to +the chairpersons of agriculture + + align:start position:0% +the chairpersons of agriculture + + + align:start position:0% +the chairpersons of agriculture +committees in EU member states as long + + align:start position:0% +committees in EU member states as long + + + align:start position:0% +committees in EU member states as long +as officials and apartments of + + align:start position:0% +as officials and apartments of + + + align:start position:0% +as officials and apartments of +agriculture in Japan Australia + + align:start position:0% +agriculture in Japan Australia + + + align:start position:0% +agriculture in Japan Australia +define our experiences that challenges + + align:start position:0% +define our experiences that challenges + + + align:start position:0% +define our experiences that challenges +and their successes we are dealing with + + align:start position:0% +and their successes we are dealing with + + + align:start position:0% +and their successes we are dealing with +farmland protection policies we also + + align:start position:0% +farmland protection policies we also + + + align:start position:0% +farmland protection policies we also +plan to look at the people to whom these + + align:start position:0% +plan to look at the people to whom these + + + align:start position:0% +plan to look at the people to whom these +effects of policies are filtering down + + align:start position:0% +effects of policies are filtering down + + + align:start position:0% +effects of policies are filtering down +to the members of farming community who + + align:start position:0% +to the members of farming community who + + + align:start position:0% +to the members of farming community who +through that individually unique stories + + align:start position:0% +through that individually unique stories + + + align:start position:0% +through that individually unique stories +are supposed to just policy man was a + + align:start position:0% +are supposed to just policy man was a + + + align:start position:0% +are supposed to just policy man was a +big day + + align:start position:0% +big day + + + align:start position:0% +big day +inform us most about issues of people we + + align:start position:0% +inform us most about issues of people we + + + align:start position:0% +inform us most about issues of people we +need these three piece together to find + + align:start position:0% +need these three piece together to find + + + align:start position:0% +need these three piece together to find +out what was intended what is happening + + align:start position:0% +out what was intended what is happening + + + align:start position:0% +out what was intended what is happening +and what it really should be so the next + + align:start position:0% +and what it really should be so the next + + + align:start position:0% +and what it really should be so the next +idea I would like to talk about would be + + align:start position:0% +idea I would like to talk about would be + + + align:start position:0% +idea I would like to talk about would be +the why you know I want to visit these + + align:start position:0% +the why you know I want to visit these + + + align:start position:0% +the why you know I want to visit these +three countries my opportunities there + + align:start position:0% +three countries my opportunities there + + + align:start position:0% +three countries my opportunities there +are + + align:start position:0% +are + + + align:start position:0% +are +is it really unnecessary available and + + align:start position:0% +is it really unnecessary available and + + + align:start position:0% +is it really unnecessary available and +ever and I would say yes because these + + align:start position:0% +ever and I would say yes because these + + + align:start position:0% +ever and I would say yes because these +three regions are similar enough to the + + align:start position:0% +three regions are similar enough to the + + + align:start position:0% +three regions are similar enough to the +US to raise the possibility of + + align:start position:0% +US to raise the possibility of + + + align:start position:0% +US to raise the possibility of +opportunities for learning and yet + + align:start position:0% +opportunities for learning and yet + + + align:start position:0% +opportunities for learning and yet +different enough to guarantee these + + align:start position:0% +different enough to guarantee these + + + align:start position:0% +different enough to guarantee these +opportunities for learning so the EU the + + align:start position:0% +opportunities for learning so the EU the + + + align:start position:0% +opportunities for learning so the EU the +US the EU Japan Australia they are and + + align:start position:0% +US the EU Japan Australia they are and + + + align:start position:0% +US the EU Japan Australia they are and +the u.s. large industrialized nations + + align:start position:0% +the u.s. large industrialized nations + + + align:start position:0% +the u.s. large industrialized nations +nobody we look beyond the blocks + + align:start position:0% +nobody we look beyond the blocks + + + align:start position:0% +nobody we look beyond the blocks +tonalities of wealth power development + + align:start position:0% +tonalities of wealth power development + + + align:start position:0% +tonalities of wealth power development +levels influence a whole host of + + align:start position:0% +levels influence a whole host of + + + align:start position:0% +levels influence a whole host of +differences appear the unlocated in + + align:start position:0% +differences appear the unlocated in + + + align:start position:0% +differences appear the unlocated in +different parts of the world in the + + align:start position:0% +different parts of the world in the + + + align:start position:0% +different parts of the world in the +Western Hemisphere in Asia and the + + align:start position:0% +Western Hemisphere in Asia and the + + + align:start position:0% +Western Hemisphere in Asia and the +southern hemisphere + + align:start position:0% +southern hemisphere + + + align:start position:0% +southern hemisphere +they have different geographies + + align:start position:0% +they have different geographies + + + align:start position:0% +they have different geographies +histories neighborhoods contexts and + + align:start position:0% +histories neighborhoods contexts and + + + align:start position:0% +histories neighborhoods contexts and +ideologies and in these differences + + align:start position:0% +ideologies and in these differences + + + align:start position:0% +ideologies and in these differences +drive cross context online for two + + align:start position:0% +drive cross context online for two + + + align:start position:0% +drive cross context online for two +reasons firstly they greatly reduce the + + align:start position:0% +reasons firstly they greatly reduce the + + + align:start position:0% +reasons firstly they greatly reduce the +learning curve for looking at the + + align:start position:0% +learning curve for looking at the + + + align:start position:0% +learning curve for looking at the +effects of different policies by + + align:start position:0% +effects of different policies by + + + align:start position:0% +effects of different policies by +providing a test build with exposed + + align:start position:0% +providing a test build with exposed + + + align:start position:0% +providing a test build with exposed +results as well + + align:start position:0% +results as well + + + align:start position:0% +results as well +so instead of sitting up live up with + + align:start position:0% +so instead of sitting up live up with + + + align:start position:0% +so instead of sitting up live up with +all of us debating the merits and + + align:start position:0% +all of us debating the merits and + + + align:start position:0% +all of us debating the merits and +demerits of increased intervention of + + align:start position:0% +demerits of increased intervention of + + + align:start position:0% +demerits of increased intervention of +online policies we need only look at + + align:start position:0% +online policies we need only look at + + + align:start position:0% +online policies we need only look at +Japan highest producer support levels + + align:start position:0% +Japan highest producer support levels + + + align:start position:0% +Japan highest producer support levels +among OECD countries with overly + + align:start position:0% +among OECD countries with overly + + + align:start position:0% +among OECD countries with overly +protected subsidies they have driven + + align:start position:0% +protected subsidies they have driven + + + align:start position:0% +protected subsidies they have driven +average annual Fung house who income + + align:start position:0% +average annual Fung house who income + + + align:start position:0% +average annual Fung house who income +levels 25 to 30 percent higher than the + + align:start position:0% +levels 25 to 30 percent higher than the + + + align:start position:0% +levels 25 to 30 percent higher than the +national average and Australia the + + align:start position:0% +national average and Australia the + + + align:start position:0% +national average and Australia the +second lowest produces support levels + + align:start position:0% +second lowest produces support levels + + + align:start position:0% +second lowest produces support levels +among OECD countries and whereas strong + + align:start position:0% +among OECD countries and whereas strong + + + align:start position:0% +among OECD countries and whereas strong +adherence to macro oriented policies has + + align:start position:0% +adherence to macro oriented policies has + + + align:start position:0% +adherence to macro oriented policies has +actually created a different result of + + align:start position:0% +actually created a different result of + + + align:start position:0% +actually created a different result of +Japan and secondly these are countries + + align:start position:0% +Japan and secondly these are countries + + + align:start position:0% +Japan and secondly these are countries +also provide us with different ideas + + align:start position:0% +also provide us with different ideas + + + align:start position:0% +also provide us with different ideas +that we might not have considered before + + align:start position:0% +that we might not have considered before + + + align:start position:0% +that we might not have considered before +for example the European Union's Common + + align:start position:0% +for example the European Union's Common + + + align:start position:0% +for example the European Union's Common +Agricultural Policy contracts with + + align:start position:0% +Agricultural Policy contracts with + + + align:start position:0% +Agricultural Policy contracts with +farmers for the development of a for the + + align:start position:0% +farmers for the development of a for the + + + align:start position:0% +farmers for the development of a for the +provision of act of ecological services + + align:start position:0% +provision of act of ecological services + + + align:start position:0% +provision of act of ecological services +which is kind of alternative to the + + align:start position:0% +which is kind of alternative to the + + + align:start position:0% +which is kind of alternative to the +traditional notion here in u.s. when + + align:start position:0% +traditional notion here in u.s. when + + + align:start position:0% +traditional notion here in u.s. when +farm land policy is essentially meant to + + align:start position:0% +farm land policy is essentially meant to + + + align:start position:0% +farm land policy is essentially meant to +product to the protect land for + + align:start position:0% +product to the protect land for + + + align:start position:0% +product to the protect land for +productive purposes + + align:start position:0% +productive purposes + + + align:start position:0% +productive purposes +so essentially exposure to these new + + align:start position:0% +so essentially exposure to these new + + + align:start position:0% +so essentially exposure to these new +ideas would provide us with a bigger + + align:start position:0% +ideas would provide us with a bigger + + + align:start position:0% +ideas would provide us with a bigger +toolkit to develop more robust + + align:start position:0% +toolkit to develop more robust + + + align:start position:0% +toolkit to develop more robust +strategies for my protection + + align:start position:0% +strategies for my protection + + + align:start position:0% +strategies for my protection +u.s. might with these great + + align:start position:0% +u.s. might with these great + + + align:start position:0% +u.s. might with these great +opportunities also come great challenges + + align:start position:0% +opportunities also come great challenges + + + align:start position:0% +opportunities also come great challenges +in the form of two in two forms + + align:start position:0% +in the form of two in two forms + + + align:start position:0% +in the form of two in two forms +essentially you differences in + + align:start position:0% +essentially you differences in + + + align:start position:0% +essentially you differences in +institutions and differences in culture + + align:start position:0% +institutions and differences in culture + + + align:start position:0% +institutions and differences in culture +so differences institutions like + + align:start position:0% +so differences institutions like + + + align:start position:0% +so differences institutions like +political systems laws they essentially + + align:start position:0% +political systems laws they essentially + + + align:start position:0% +political systems laws they essentially +make policies nor body relevance in the + + align:start position:0% +make policies nor body relevance in the + + + align:start position:0% +make policies nor body relevance in the +United States in certain way so in a + + align:start position:0% +United States in certain way so in a + + + align:start position:0% +United States in certain way so in a +European Union they have a greater + + align:start position:0% +European Union they have a greater + + + align:start position:0% +European Union they have a greater +acceptance of regional international + + align:start position:0% +acceptance of regional international + + + align:start position:0% +acceptance of regional international +treaties and conventions and this is + + align:start position:0% +treaties and conventions and this is + + + align:start position:0% +treaties and conventions and this is +implications for trying to transplant + + align:start position:0% +implications for trying to transplant + + + align:start position:0% +implications for trying to transplant +policies across their latitude and + + align:start position:0% +policies across their latitude and + + + align:start position:0% +policies across their latitude and +culture we cannot underestimate the + + align:start position:0% +culture we cannot underestimate the + + + align:start position:0% +culture we cannot underestimate the +influence of culture history and + + align:start position:0% +influence of culture history and + + + align:start position:0% +influence of culture history and +policies for example after all in Japan + + align:start position:0% +policies for example after all in Japan + + + align:start position:0% +policies for example after all in Japan +that the reason for the high levels of + + align:start position:0% +that the reason for the high levels of + + + align:start position:0% +that the reason for the high levels of +produces the pot and essentially do can + + align:start position:0% +produces the pot and essentially do can + + + align:start position:0% +produces the pot and essentially do can +be traced back to the memories of food + + align:start position:0% +be traced back to the memories of food + + + align:start position:0% +be traced back to the memories of food +shortage that occurred after World War + + align:start position:0% +shortage that occurred after World War + + + align:start position:0% +shortage that occurred after World War +two something that cannot be said of the + + align:start position:0% +two something that cannot be said of the + + + align:start position:0% +two something that cannot be said of the +US so what may be popular in one country + + align:start position:0% +US so what may be popular in one country + + + align:start position:0% +US so what may be popular in one country +may be very unpopular in another so what + + align:start position:0% +may be very unpopular in another so what + + + align:start position:0% +may be very unpopular in another so what +we intend to do on outfits is not to be + + align:start position:0% +we intend to do on outfits is not to be + + + align:start position:0% +we intend to do on outfits is not to be +transplanted of these policies back to + + align:start position:0% +transplanted of these policies back to + + + align:start position:0% +transplanted of these policies back to +the u.s. we intend to be translators + + align:start position:0% +the u.s. we intend to be translators + + + align:start position:0% +the u.s. we intend to be translators +where we take the spirit and not the + + align:start position:0% +where we take the spirit and not the + + + align:start position:0% +where we take the spirit and not the +letter of these policies and combine it + + align:start position:0% +letter of these policies and combine it + + + align:start position:0% +letter of these policies and combine it +with our understanding of the realities + + align:start position:0% +with our understanding of the realities + + + align:start position:0% +with our understanding of the realities +here in the u.s. to develop a selection + + align:start position:0% +here in the u.s. to develop a selection + + + align:start position:0% +here in the u.s. to develop a selection +of ideas that circumvent differences + + align:start position:0% +of ideas that circumvent differences + + + align:start position:0% +of ideas that circumvent differences +institutions and account for differences + + align:start position:0% +institutions and account for differences + + + align:start position:0% +institutions and account for differences +in culture that's it even in the u.s. + + align:start position:0% +in culture that's it even in the u.s. + + + align:start position:0% +in culture that's it even in the u.s. +that institutions do change and cultures + + align:start position:0% +that institutions do change and cultures + + + align:start position:0% +that institutions do change and cultures +do evolve or be it at a much lower rate + + align:start position:0% +do evolve or be it at a much lower rate + + + align:start position:0% +do evolve or be it at a much lower rate +and even in within the country country + + align:start position:0% +and even in within the country country + + + align:start position:0% +and even in within the country country +cultures will vary widely + + align:start position:0% +cultures will vary widely + + + align:start position:0% +cultures will vary widely +so even ideas that seem improbable for + + align:start position:0% +so even ideas that seem improbable for + + + align:start position:0% +so even ideas that seem improbable for +now should not be discarded but kept for + + align:start position:0% +now should not be discarded but kept for + + + align:start position:0% +now should not be discarded but kept for +future reference so whenever the time + + align:start position:0% +future reference so whenever the time + + + align:start position:0% +future reference so whenever the time +comes we are ready to defend them so in + + align:start position:0% +comes we are ready to defend them so in + + + align:start position:0% +comes we are ready to defend them so in +conclusion my trips will have great a + + align:start position:0% +conclusion my trips will have great a + + + align:start position:0% +conclusion my trips will have great a +deep and benamber + + align:start position:0% +deep and benamber + + + align:start position:0% +deep and benamber +opportunities that also are fraught with + + align:start position:0% +opportunities that also are fraught with + + + align:start position:0% +opportunities that also are fraught with +challenges but an appreciation that + + align:start position:0% +challenges but an appreciation that + + + align:start position:0% +challenges but an appreciation that +promise the differences in countries are + + align:start position:0% +promise the differences in countries are + + + align:start position:0% +promise the differences in countries are +the drivers of learning and not + + align:start position:0% +the drivers of learning and not + + + align:start position:0% +the drivers of learning and not +similarities and also an appreciation + + align:start position:0% +similarities and also an appreciation + + + align:start position:0% +similarities and also an appreciation +that policy learning observations are + + align:start position:0% +that policy learning observations are + + + align:start position:0% +that policy learning observations are +just start to a greater translation + + align:start position:0% +just start to a greater translation + + + align:start position:0% +just start to a greater translation +efforts should allow us to reap the full + + align:start position:0% +efforts should allow us to reap the full + + + align:start position:0% +efforts should allow us to reap the full +benefits of our trips of thank you for \ No newline at end of file diff --git a/UdEX0E9lIQM.txt b/UdEX0E9lIQM.txt new file mode 100644 index 0000000000000000000000000000000000000000..f81e516dab2b0f97141a846720e45e665799bf71 --- /dev/null +++ b/UdEX0E9lIQM.txt @@ -0,0 +1,14643 @@ +align:start position:0% + +so let's start today's lecture we're + + align:start position:0% +so let's start today's lecture we're + + + align:start position:0% +so let's start today's lecture we're +going to be looking at sort of three + + align:start position:0% +going to be looking at sort of three + + + align:start position:0% +going to be looking at sort of three +different topics the first is we're + + align:start position:0% +different topics the first is we're + + + align:start position:0% +different topics the first is we're +going to look at a new object type + + align:start position:0% +going to look at a new object type + + + align:start position:0% +going to look at a new object type +called a string we briefly mentioned + + align:start position:0% +called a string we briefly mentioned + + + align:start position:0% +called a string we briefly mentioned +this word last lecture then we're going + + align:start position:0% +this word last lecture then we're going + + + align:start position:0% +this word last lecture then we're going +to see how we can write programs that + + align:start position:0% +to see how we can write programs that + + + align:start position:0% +to see how we can write programs that +start to get input from the user and + + align:start position:0% +start to get input from the user and + + + align:start position:0% +start to get input from the user and +show the user + + align:start position:0% +show the user + + + align:start position:0% +show the user +output and finally we're going to go + + align:start position:0% +output and finally we're going to go + + + align:start position:0% +output and finally we're going to go +into writing a little bit more + + align:start position:0% +into writing a little bit more + + + align:start position:0% +into writing a little bit more +interesting programs that uh that make + + align:start position:0% +interesting programs that uh that make + + + align:start position:0% +interesting programs that uh that make +decisions based on decisions that we + + align:start position:0% +decisions based on decisions that we + + + align:start position:0% +decisions based on decisions that we +actually input in the code so not + + align:start position:0% +actually input in the code so not + + + align:start position:0% +actually input in the code so not +decisions spontaneously but things that + + align:start position:0% +decisions spontaneously but things that + + + align:start position:0% +decisions spontaneously but things that +we will code within our programs but + + align:start position:0% +we will code within our programs but + + + align:start position:0% +we will code within our programs but +before we go on to these topics I just + + align:start position:0% +before we go on to these topics I just + + + align:start position:0% +before we go on to these topics I just +wanted to do a quick recap of what we + + align:start position:0% +wanted to do a quick recap of what we + + + align:start position:0% +wanted to do a quick recap of what we +learned last lecture just to make sure + + align:start position:0% +learned last lecture just to make sure + + + align:start position:0% +learned last lecture just to make sure +we're all on the same page so we + + align:start position:0% +we're all on the same page so we + + + align:start position:0% +we're all on the same page so we +introduced the idea of an object and + + align:start position:0% +introduced the idea of an object and + + + align:start position:0% +introduced the idea of an object and +every object in python has a specific + + align:start position:0% +every object in python has a specific + + + align:start position:0% +every object in python has a specific +type and the type tells python the kinds + + align:start position:0% +type and the type tells python the kinds + + + align:start position:0% +type and the type tells python the kinds +of things you're allowed to do with that + + align:start position:0% +of things you're allowed to do with that + + + align:start position:0% +of things you're allowed to do with that +object okay um we talked about once you + + align:start position:0% +object okay um we talked about once you + + + align:start position:0% +object okay um we talked about once you +have objects you can actually assign + + align:start position:0% +have objects you can actually assign + + + align:start position:0% +have objects you can actually assign +these objects to variables and these + + align:start position:0% +these objects to variables and these + + + align:start position:0% +these objects to variables and these +variables basically bind a name to the + + align:start position:0% +variables basically bind a name to the + + + align:start position:0% +variables basically bind a name to the +object in memory with objects you can + + align:start position:0% +object in memory with objects you can + + + align:start position:0% +object in memory with objects you can +also create Expressions by combining + + align:start position:0% +also create Expressions by combining + + + align:start position:0% +also create Expressions by combining +objects together and the Expressions can + + align:start position:0% +objects together and the Expressions can + + + align:start position:0% +objects together and the Expressions can +either be things that we've seen in math + + align:start position:0% +either be things that we've seen in math + + + align:start position:0% +either be things that we've seen in math +like with parentheses and with operator + + align:start position:0% +like with parentheses and with operator + + + align:start position:0% +like with parentheses and with operator +like object operator object or they can + + align:start position:0% +like object operator object or they can + + + align:start position:0% +like object operator object or they can +be things like this which we which was + + align:start position:0% +be things like this which we which was + + + align:start position:0% +be things like this which we which was +kind of introduced in programming it's + + align:start position:0% +kind of introduced in programming it's + + + align:start position:0% +kind of introduced in programming it's +an expression but it's kind of a + + align:start position:0% +an expression but it's kind of a + + + align:start position:0% +an expression but it's kind of a +different one it's uh more like a + + align:start position:0% +different one it's uh more like a + + + align:start position:0% +different one it's uh more like a +command or I'm asking python to do this + + align:start position:0% +command or I'm asking python to do this + + + align:start position:0% +command or I'm asking python to do this +operation for me what is the object that + + align:start position:0% +operation for me what is the object that + + + align:start position:0% +operation for me what is the object that +comes back from this + + align:start position:0% +comes back from this + + + align:start position:0% +comes back from this +operation so today um I'm going to go + + align:start position:0% +operation so today um I'm going to go + + + align:start position:0% +operation so today um I'm going to go +over this little uh sort of memory + + align:start position:0% +over this little uh sort of memory + + + align:start position:0% +over this little uh sort of memory +diagram we started drawing last lecture + + align:start position:0% +diagram we started drawing last lecture + + + align:start position:0% +diagram we started drawing last lecture +and I'm going to use this memory diagram + + align:start position:0% +and I'm going to use this memory diagram + + + align:start position:0% +and I'm going to use this memory diagram +today as well um here's some lines of + + align:start position:0% +today as well um here's some lines of + + + align:start position:0% +today as well um here's some lines of +code that we wrote last lecture so we + + align:start position:0% +code that we wrote last lecture so we + + + align:start position:0% +code that we wrote last lecture so we +created uh we we wrote a line in Python + + align:start position:0% +created uh we we wrote a line in Python + + + align:start position:0% +created uh we we wrote a line in Python +that created an object its value is 3.14 + + align:start position:0% +that created an object its value is 3.14 + + + align:start position:0% +that created an object its value is 3.14 +a float in memory and the name we gave + + align:start position:0% +a float in memory and the name we gave + + + align:start position:0% +a float in memory and the name we gave +this object was Pi so just the the name + + align:start position:0% +this object was Pi so just the the name + + + align:start position:0% +this object was Pi so just the the name +Pi + + align:start position:0% +Pi + + + align:start position:0% +Pi +Pi radius equals 2.2 is another + + align:start position:0% +Pi radius equals 2.2 is another + + + align:start position:0% +Pi radius equals 2.2 is another +assignment uh statement in Python and it + + align:start position:0% +assignment uh statement in Python and it + + + align:start position:0% +assignment uh statement in Python and it +binds the name radius to the value 2.2 + + align:start position:0% +binds the name radius to the value 2.2 + + + align:start position:0% +binds the name radius to the value 2.2 +in memory and once we've created these + + align:start position:0% +in memory and once we've created these + + + align:start position:0% +in memory and once we've created these +variables we can just invoke their names + + align:start position:0% +variables we can just invoke their names + + + align:start position:0% +variables we can just invoke their names +we can use their names to tell python to + + align:start position:0% +we can use their names to tell python to + + + align:start position:0% +we can use their names to tell python to +grab for me the values from memory so + + align:start position:0% +grab for me the values from memory so + + + align:start position:0% +grab for me the values from memory so +when python sees Pi * radius star star 2 + + align:start position:0% +when python sees Pi * radius star star 2 + + + align:start position:0% +when python sees Pi * radius star star 2 +that means take Pi multiply it with the + + align:start position:0% +that means take Pi multiply it with the + + + align:start position:0% +that means take Pi multiply it with the +radius squared so behind the scenes + + align:start position:0% +radius squared so behind the scenes + + + align:start position:0% +radius squared so behind the scenes +python goes grabs the value 3.14 from + + align:start position:0% +python goes grabs the value 3.14 from + + + align:start position:0% +python goes grabs the value 3.14 from +memory replaces Pi with that value grabs + + align:start position:0% +memory replaces Pi with that value grabs + + + align:start position:0% +memory replaces Pi with that value grabs +2.2 from memory replaces radius with + + align:start position:0% +2.2 from memory replaces radius with + + + align:start position:0% +2.2 from memory replaces radius with +that value does the operation according + + align:start position:0% +that value does the operation according + + + align:start position:0% +that value does the operation according +to the precedent rules and then that + + align:start position:0% +to the precedent rules and then that + + + align:start position:0% +to the precedent rules and then that +expression the thing on the right hand + + align:start position:0% +expression the thing on the right hand + + + align:start position:0% +expression the thing on the right hand +side of this equal sign becomes a value + + align:start position:0% +side of this equal sign becomes a value + + + align:start position:0% +side of this equal sign becomes a value +that value is then created as a new + + align:start position:0% +that value is then created as a new + + + align:start position:0% +that value is then created as a new +object in memory right here and that + + align:start position:0% +object in memory right here and that + + + align:start position:0% +object in memory right here and that +object in memory is then bound to the + + align:start position:0% +object in memory is then bound to the + + + align:start position:0% +object in memory is then bound to the +name area that's exactly what this + + align:start position:0% +name area that's exactly what this + + + align:start position:0% +name area that's exactly what this +assignment statement said okay and we + + align:start position:0% +assignment statement said okay and we + + + align:start position:0% +assignment statement said okay and we +can do something like this in Python + + align:start position:0% +can do something like this in Python + + + align:start position:0% +can do something like this in Python +which we can't actually do in math right + + align:start position:0% +which we can't actually do in math right + + + align:start position:0% +which we can't actually do in math right +if we did this in math the expression + + align:start position:0% +if we did this in math the expression + + + align:start position:0% +if we did this in math the expression +would basically say 0 equals 1 but in + + align:start position:0% +would basically say 0 equals 1 but in + + + align:start position:0% +would basically say 0 equals 1 but in +Python it's totally fine because again + + align:start position:0% +Python it's totally fine because again + + + align:start position:0% +Python it's totally fine because again +we evaluate the thing on the right hand + + align:start position:0% +we evaluate the thing on the right hand + + + align:start position:0% +we evaluate the thing on the right hand +side of the equal sign so on the right + + align:start position:0% +side of the equal sign so on the right + + + align:start position:0% +side of the equal sign so on the right +hand side of the equal sign we say I + + align:start position:0% +hand side of the equal sign we say I + + + align:start position:0% +hand side of the equal sign we say I +want to grab the value of radius so 2.2 + + align:start position:0% +want to grab the value of radius so 2.2 + + + align:start position:0% +want to grab the value of radius so 2.2 +add one to it 3.2 create this object in + + align:start position:0% +add one to it 3.2 create this object in + + + align:start position:0% +add one to it 3.2 create this object in +memory here I have a whole new object in + + align:start position:0% +memory here I have a whole new object in + + + align:start position:0% +memory here I have a whole new object in +memory 3.2 and then assign it to the + + align:start position:0% +memory 3.2 and then assign it to the + + + align:start position:0% +memory 3.2 and then assign it to the +name radius so I've lost The Binding + + align:start position:0% +name radius so I've lost The Binding + + + align:start position:0% +name radius so I've lost The Binding +from the original 2.2 and rebound the + + align:start position:0% +from the original 2.2 and rebound the + + + align:start position:0% +from the original 2.2 and rebound the +name to 3.2 okay so we're not modifying + + align:start position:0% +name to 3.2 okay so we're not modifying + + + align:start position:0% +name to 3.2 okay so we're not modifying +objects in memory we're creating new + + align:start position:0% +objects in memory we're creating new + + + align:start position:0% +objects in memory we're creating new +objects in memory whenever we uh do such + + align:start position:0% +objects in memory whenever we uh do such + + + align:start position:0% +objects in memory whenever we uh do such +operations we're going to see how we can + + align:start position:0% +operations we're going to see how we can + + + align:start position:0% +operations we're going to see how we can +modify objects way into the + + align:start position:0% +modify objects way into the + + + align:start position:0% +modify objects way into the +future and uh just sort of for + + align:start position:0% +future and uh just sort of for + + + align:start position:0% +future and uh just sort of for +completion when we have a line that says + + align:start position:0% +completion when we have a line that says + + + align:start position:0% +completion when we have a line that says +VAR is equal type five multiplied by + + align:start position:0% +VAR is equal type five multiplied by + + + align:start position:0% +VAR is equal type five multiplied by +four python also sees this as an + + align:start position:0% +four python also sees this as an + + + align:start position:0% +four python also sees this as an +expression and so as an expression it + + align:start position:0% +expression and so as an expression it + + + align:start position:0% +expression and so as an expression it +has a value so the right hand side of + + align:start position:0% +has a value so the right hand side of + + + align:start position:0% +has a value so the right hand side of +this equal sign says well I'm going to + + align:start position:0% +this equal sign says well I'm going to + + + align:start position:0% +this equal sign says well I'm going to +sort of systematically evaluate this and + + align:start position:0% +sort of systematically evaluate this and + + + align:start position:0% +sort of systematically evaluate this and +say what's 5 * 4 it's + + align:start position:0% +say what's 5 * 4 it's + + + align:start position:0% +say what's 5 * 4 it's +20 what's the type of 20 it's an integer + + align:start position:0% +20 what's the type of 20 it's an integer + + + align:start position:0% +20 what's the type of 20 it's an integer +and so that's what the right hand side + + align:start position:0% +and so that's what the right hand side + + + align:start position:0% +and so that's what the right hand side +evaluates to an integer and I'm going to + + align:start position:0% +evaluates to an integer and I'm going to + + + align:start position:0% +evaluates to an integer and I'm going to +bom find that value int to the name VAR + + align:start position:0% +bom find that value int to the name VAR + + + align:start position:0% +bom find that value int to the name VAR +okay so VAR is another variable name and + + align:start position:0% +okay so VAR is another variable name and + + + align:start position:0% +okay so VAR is another variable name and +its value is int right the type of my + + align:start position:0% +its value is int right the type of my + + + align:start position:0% +its value is int right the type of my +object which is a little strange right + + align:start position:0% +object which is a little strange right + + + align:start position:0% +object which is a little strange right +so far we've kind of just put numbers in + + align:start position:0% +so far we've kind of just put numbers in + + + align:start position:0% +so far we've kind of just put numbers in +our memory but we can put any object + + align:start position:0% +our memory but we can put any object + + + align:start position:0% +our memory but we can put any object +type in + + align:start position:0% +type in + + + align:start position:0% +type in +memory okay so let's move on a little + + align:start position:0% +memory okay so let's move on a little + + + align:start position:0% +memory okay so let's move on a little +bit uh in onto the new object type + + align:start position:0% +bit uh in onto the new object type + + + align:start position:0% +bit uh in onto the new object type +called a string so a string is actually + + align:start position:0% +called a string so a string is actually + + + align:start position:0% +called a string so a string is actually +a sequence of K sensitive + + align:start position:0% +a sequence of K sensitive + + + align:start position:0% +a sequence of K sensitive +characters um the characters can be + + align:start position:0% +characters um the characters can be + + + align:start position:0% +characters um the characters can be +anything uh we have lowercase letters + + align:start position:0% +anything uh we have lowercase letters + + + align:start position:0% +anything uh we have lowercase letters +uppercase letters the numbers on your + + align:start position:0% +uppercase letters the numbers on your + + + align:start position:0% +uppercase letters the numbers on your +keyboard the special characters you see + + align:start position:0% +keyboard the special characters you see + + + align:start position:0% +keyboard the special characters you see +on the keyboard even the enter when you + + align:start position:0% +on the keyboard even the enter when you + + + align:start position:0% +on the keyboard even the enter when you +do a new line or a tab has a special + + align:start position:0% +do a new line or a tab has a special + + + align:start position:0% +do a new line or a tab has a special +character associated with it and the way + + align:start position:0% +character associated with it and the way + + + align:start position:0% +character associated with it and the way +we tell python we're creating an object + + align:start position:0% +we tell python we're creating an object + + + align:start position:0% +we tell python we're creating an object +of type string is by enclosing the the + + align:start position:0% +of type string is by enclosing the the + + + align:start position:0% +of type string is by enclosing the the +characters we want to be part of that + + align:start position:0% +characters we want to be part of that + + + align:start position:0% +characters we want to be part of that +object in these quotation marks so when + + align:start position:0% +object in these quotation marks so when + + + align:start position:0% +object in these quotation marks so when +python sees the quotation mark it knows + + align:start position:0% +python sees the quotation mark it knows + + + align:start position:0% +python sees the quotation mark it knows +you're creating a string object so here + + align:start position:0% +you're creating a string object so here + + + align:start position:0% +you're creating a string object so here +I'm creating the string object uh which + + align:start position:0% +I'm creating the string object uh which + + + align:start position:0% +I'm creating the string object uh which +has the lowercase letter M lowercase + + align:start position:0% +has the lowercase letter M lowercase + + + align:start position:0% +has the lowercase letter M lowercase +letter e and here I'm creating the uh + + align:start position:0% +letter e and here I'm creating the uh + + + align:start position:0% +letter e and here I'm creating the uh +string object which has the lowercase y + + align:start position:0% +string object which has the lowercase y + + + align:start position:0% +string object which has the lowercase y +lowercase o and lowercase U letters and + + align:start position:0% +lowercase o and lowercase U letters and + + + align:start position:0% +lowercase o and lowercase U letters and +these objects are things in Python and + + align:start position:0% +these objects are things in Python and + + + align:start position:0% +these objects are things in Python and +we're just going to give them a handle a + + align:start position:0% +we're just going to give them a handle a + + + align:start position:0% +we're just going to give them a handle a +binding with some more convenient + + align:start position:0% +binding with some more convenient + + + align:start position:0% +binding with some more convenient +variable names A and Z so in memory the + + align:start position:0% +variable names A and Z so in memory the + + + align:start position:0% +variable names A and Z so in memory the +way this would look in a little me + + align:start position:0% +way this would look in a little me + + + align:start position:0% +way this would look in a little me +memory diagram is we would have the + + align:start position:0% +memory diagram is we would have the + + + align:start position:0% +memory diagram is we would have the +string uh characters me bound to the + + align:start position:0% +string uh characters me bound to the + + + align:start position:0% +string uh characters me bound to the +variable a right so basically what we've + + align:start position:0% +variable a right so basically what we've + + + align:start position:0% +variable a right so basically what we've +seen + + align:start position:0% +seen + + + align:start position:0% +seen +before all right so now what are some + + align:start position:0% +before all right so now what are some + + + align:start position:0% +before all right so now what are some +things we can do with strings well some + + align:start position:0% +things we can do with strings well some + + + align:start position:0% +things we can do with strings well some +really common operations is are that we + + align:start position:0% +really common operations is are that we + + + align:start position:0% +really common operations is are that we +can concatenate strings or we can repeat + + align:start position:0% +can concatenate strings or we can repeat + + + align:start position:0% +can concatenate strings or we can repeat +strings so here I'm not going to put the + + align:start position:0% +strings so here I'm not going to put the + + + align:start position:0% +strings so here I'm not going to put the +Z in memory you can kind of imagine how + + align:start position:0% +Z in memory you can kind of imagine how + + + align:start position:0% +Z in memory you can kind of imagine how +that would look like but let's say I + + align:start position:0% +that would look like but let's say I + + + align:start position:0% +that would look like but let's say I +create now a variable b equals the + + align:start position:0% +create now a variable b equals the + + + align:start position:0% +create now a variable b equals the +letters uh my y c + + align:start position:0% +letters uh my y c + + + align:start position:0% +letters uh my y c +LF what if I do a plus operator between + + align:start position:0% +LF what if I do a plus operator between + + + align:start position:0% +LF what if I do a plus operator between +these two strings the plus operator + + align:start position:0% +these two strings the plus operator + + + align:start position:0% +these two strings the plus operator +tells python that I'm going to take + + align:start position:0% +tells python that I'm going to take + + + align:start position:0% +tells python that I'm going to take +these two strings the individual + + align:start position:0% +these two strings the individual + + + align:start position:0% +these two strings the individual +characters in each string and kind of + + align:start position:0% +characters in each string and kind of + + + align:start position:0% +characters in each string and kind of +just put them together to make one new + + align:start position:0% +just put them together to make one new + + + align:start position:0% +just put them together to make one new +object that is all of these letters put + + align:start position:0% +object that is all of these letters put + + + align:start position:0% +object that is all of these letters put +together so C is equal to a plus b is + + align:start position:0% +together so C is equal to a plus b is + + + align:start position:0% +together so C is equal to a plus b is +another uh uh assignment operator and on + + align:start position:0% +another uh uh assignment operator and on + + + align:start position:0% +another uh uh assignment operator and on +the right hand side we have an + + align:start position:0% +the right hand side we have an + + + align:start position:0% +the right hand side we have an +expression plus operator between two + + align:start position:0% +expression plus operator between two + + + align:start position:0% +expression plus operator between two +objects it's going to put me which is + + align:start position:0% +objects it's going to put me which is + + + align:start position:0% +objects it's going to put me which is +the uh the c letters and the my LF the + + align:start position:0% +the uh the c letters and the my LF the + + + align:start position:0% +the uh the c letters and the my LF the +uh B letters Al together to create a new + + align:start position:0% +uh B letters Al together to create a new + + + align:start position:0% +uh B letters Al together to create a new +object which I then give a handle a + + align:start position:0% +object which I then give a handle a + + + align:start position:0% +object which I then give a handle a +binding C so from now on anytime I want + + align:start position:0% +binding C so from now on anytime I want + + + align:start position:0% +binding C so from now on anytime I want +this particular uh string of characters + + align:start position:0% +this particular uh string of characters + + + align:start position:0% +this particular uh string of characters +M me m + + align:start position:0% +M me m + + + align:start position:0% +M me m +ysf I can just invoke the name c in my + + align:start position:0% +ysf I can just invoke the name c in my + + + align:start position:0% +ysf I can just invoke the name c in my +program that's just the variable name + + align:start position:0% +program that's just the variable name + + + align:start position:0% +program that's just the variable name +that I gave + + align:start position:0% +that I gave + + + align:start position:0% +that I gave +it now notice it didn't insert a space + + align:start position:0% +it now notice it didn't insert a space + + + align:start position:0% +it now notice it didn't insert a space +right it didn't do me space myself + + align:start position:0% +right it didn't do me space myself + + + align:start position:0% +right it didn't do me space myself +because we didn't tell it to do a space + + align:start position:0% +because we didn't tell it to do a space + + + align:start position:0% +because we didn't tell it to do a space +so if we want it to do a space we'd have + + align:start position:0% +so if we want it to do a space we'd have + + + align:start position:0% +so if we want it to do a space we'd have +to put it in ourselves so we can + + align:start position:0% +to put it in ourselves so we can + + + align:start position:0% +to put it in ourselves so we can +concatenate so we can have a larger + + align:start position:0% +concatenate so we can have a larger + + + align:start position:0% +concatenate so we can have a larger +expression where we concatenate a with a + + align:start position:0% +expression where we concatenate a with a + + + align:start position:0% +expression where we concatenate a with a +space and with B together so that will + + align:start position:0% +space and with B together so that will + + + align:start position:0% +space and with B together so that will +give me an entirely new object in memory + + align:start position:0% +give me an entirely new object in memory + + + align:start position:0% +give me an entirely new object in memory +the string me space m y s e LF this new + + align:start position:0% +the string me space m y s e LF this new + + + align:start position:0% +the string me space m y s e LF this new +object is bound to the name + + align:start position:0% +object is bound to the name + + + align:start position:0% +object is bound to the name +d is that okay so far does that make + + align:start position:0% +d is that okay so far does that make + + + align:start position:0% +d is that okay so far does that make +sense okay all right so that's + + align:start position:0% +sense okay all right so that's + + + align:start position:0% +sense okay all right so that's +concatenation basically takes these two + + align:start position:0% +concatenation basically takes these two + + + align:start position:0% +concatenation basically takes these two +string characters puts them together in + + align:start position:0% +string characters puts them together in + + + align:start position:0% +string characters puts them together in +a new object what about the star I kind + + align:start position:0% +a new object what about the star I kind + + + align:start position:0% +a new object what about the star I kind +of briefly talked about this as + + align:start position:0% +of briefly talked about this as + + + align:start position:0% +of briefly talked about this as +repeating something last lecture well + + align:start position:0% +repeating something last lecture well + + + align:start position:0% +repeating something last lecture well +the star operator Works between a string + + align:start position:0% +the star operator Works between a string + + + align:start position:0% +the star operator Works between a string +and a number it doesn't work between a + + align:start position:0% +and a number it doesn't work between a + + + align:start position:0% +and a number it doesn't work between a +string and a string it doesn't work + + align:start position:0% +string and a string it doesn't work + + + align:start position:0% +string and a string it doesn't work +between uh you know things like that it + + align:start position:0% +between uh you know things like that it + + + align:start position:0% +between uh you know things like that it +works between a string and a number in + + align:start position:0% +works between a string and a number in + + + align:start position:0% +works between a string and a number in +either order so a number string or + + align:start position:0% +either order so a number string or + + + align:start position:0% +either order so a number string or +string times + + align:start position:0% +string times + + + align:start position:0% +string times +number so here again it's an assignment + + align:start position:0% +number so here again it's an assignment + + + align:start position:0% +number so here again it's an assignment +operator the right hand side we're going + + align:start position:0% +operator the right hand side we're going + + + align:start position:0% +operator the right hand side we're going +to figure out what it what it evaluates + + align:start position:0% +to figure out what it what it evaluates + + + align:start position:0% +to figure out what it what it evaluates +to first so a * 3 means I'm going to + + align:start position:0% +to first so a * 3 means I'm going to + + + align:start position:0% +to first so a * 3 means I'm going to +repeat this particular sequence of + + align:start position:0% +repeat this particular sequence of + + + align:start position:0% +repeat this particular sequence of +characters me because that's what a is + + align:start position:0% +characters me because that's what a is + + + align:start position:0% +characters me because that's what a is +it's me three times + + align:start position:0% +it's me three times + + + align:start position:0% +it's me three times +so this line of code here is going to + + align:start position:0% +so this line of code here is going to + + + align:start position:0% +so this line of code here is going to +create me me me as a new object and the + + align:start position:0% +create me me me as a new object and the + + + align:start position:0% +create me me me as a new object and the +equal sign tells it to bind it to the + + align:start position:0% +equal sign tells it to bind it to the + + + align:start position:0% +equal sign tells it to bind it to the +name silly so anytime I want to grab + + align:start position:0% +name silly so anytime I want to grab + + + align:start position:0% +name silly so anytime I want to grab +this particular string of characters for + + align:start position:0% +this particular string of characters for + + + align:start position:0% +this particular string of characters for +memory I can just type in silly in my + + align:start position:0% +memory I can just type in silly in my + + + align:start position:0% +memory I can just type in silly in my +program and that will automatically grab + + align:start position:0% +program and that will automatically grab + + + align:start position:0% +program and that will automatically grab +that particular sequence of characters + + align:start position:0% +that particular sequence of characters + + + align:start position:0% +that particular sequence of characters +from + + align:start position:0% +from + + + align:start position:0% +from +memory all right let's do a quick + + align:start position:0% +memory all right let's do a quick + + + align:start position:0% +memory all right let's do a quick +exercise to make sure that you all have + + align:start position:0% +exercise to make sure that you all have + + + align:start position:0% +exercise to make sure that you all have +this and um as you're thinking about + + align:start position:0% +this and um as you're thinking about + + + align:start position:0% +this and um as you're thinking about +what this does I can can start typing it + + align:start position:0% +what this does I can can start typing it + + + align:start position:0% +what this does I can can start typing it +in uh to the um to the console um or you + + align:start position:0% +in uh to the um to the console um or you + + + align:start position:0% +in uh to the um to the console um or you +can either even type it in to check uh + + align:start position:0% +can either even type it in to check uh + + + align:start position:0% +can either even type it in to check uh +yourself so B is going to be colon and C + + align:start position:0% +yourself so B is going to be colon and C + + + align:start position:0% +yourself so B is going to be colon and C +is going to be the closed + + align:start position:0% +is going to be the closed + + + align:start position:0% +is going to be the closed +parenthesis so if we go here right we + + align:start position:0% +parenthesis so if we go here right we + + + align:start position:0% +parenthesis so if we go here right we +have B is equal to just this + + align:start position:0% +have B is equal to just this + + + align:start position:0% +have B is equal to just this +colon and C is equal to the Clos + + align:start position:0% +colon and C is equal to the Clos + + + align:start position:0% +colon and C is equal to the Clos +parenthesis and we don't have to do all + + align:start position:0% +parenthesis and we don't have to do all + + + align:start position:0% +parenthesis and we don't have to do all +the operations at once right we can just + + align:start position:0% +the operations at once right we can just + + + align:start position:0% +the operations at once right we can just +do something like 2 * C and figure out + + align:start position:0% +do something like 2 * C and figure out + + + align:start position:0% +do something like 2 * C and figure out +what that is right it's just repeating + + align:start position:0% +what that is right it's just repeating + + + align:start position:0% +what that is right it's just repeating +the closed parenthesis twice and then we + + align:start position:0% +the closed parenthesis twice and then we + + + align:start position:0% +the closed parenthesis twice and then we +can do B + 2 * + + align:start position:0% +can do B + 2 * + + + align:start position:0% +can do B + 2 * +C to give us closed parenthesis or colon + + align:start position:0% +C to give us closed parenthesis or colon + + + align:start position:0% +C to give us closed parenthesis or colon +closed parenthesis Clos parenthesis + + align:start position:0% +closed parenthesis Clos parenthesis + + + align:start position:0% +closed parenthesis Clos parenthesis +right so super + + align:start position:0% + + + + align:start position:0% + +happy what about the next one f is + + align:start position:0% +happy what about the next one f is + + + align:start position:0% +happy what about the next one f is +a g is actually the + + align:start position:0% +a g is actually the + + + align:start position:0% +a g is actually the +space b right so there's a space + + align:start position:0% +space b right so there's a space + + + align:start position:0% +space b right so there's a space +character in there little trick + + align:start position:0% +character in there little trick + + + align:start position:0% +character in there little trick +and H is + + align:start position:0% +and H is + + + align:start position:0% +and H is +three is this the number three or the + + align:start position:0% +three is this the number three or the + + + align:start position:0% +three is this the number three or the +string three for + + align:start position:0% +string three for + + + align:start position:0% +string three for +H yeah exactly it's the string + + align:start position:0% +H yeah exactly it's the string + + + align:start position:0% +H yeah exactly it's the string +three so what is f plus G again we can + + align:start position:0% +three so what is f plus G again we can + + + align:start position:0% +three so what is f plus G again we can +do it in pieces what is f plus + + align:start position:0% + + + + align:start position:0% + +g a space b exactly right a is uh um a + + align:start position:0% +g a space b exactly right a is uh um a + + + align:start position:0% +g a space b exactly right a is uh um a +is by itself and G is a space b what is + + align:start position:0% +is by itself and G is a space b what is + + + align:start position:0% +is by itself and G is a space b what is +int + + align:start position:0% + + + + align:start position:0% + +H yes yeah it's just three what's the + + align:start position:0% +H yes yeah it's just three what's the + + + align:start position:0% +H yes yeah it's just three what's the +type of + + align:start position:0% +type of + + + align:start position:0% +type of +three int exactly I just cast it to an + + align:start position:0% +three int exactly I just cast it to an + + + align:start position:0% +three int exactly I just cast it to an +INT right so if I have f is equal to a g + + align:start position:0% +INT right so if I have f is equal to a g + + + align:start position:0% +INT right so if I have f is equal to a g +is equal to space + + align:start position:0% +is equal to space + + + align:start position:0% +is equal to space +B and H is equal to the string + + align:start position:0% +B and H is equal to the string + + + align:start position:0% +B and H is equal to the string +three um f+ G we're doing it in uh a + + align:start position:0% +three um f+ G we're doing it in uh a + + + align:start position:0% +three um f+ G we're doing it in uh a +little bit at a time right is a space B + + align:start position:0% +little bit at a time right is a space B + + + align:start position:0% +little bit at a time right is a space B +and H is just see this string three here + + align:start position:0% +and H is just see this string three here + + + align:start position:0% +and H is just see this string three here +so if I cast it to + + align:start position:0% +so if I cast it to + + + align:start position:0% +so if I cast it to +an integer it gives me just the number + + align:start position:0% +an integer it gives me just the number + + + align:start position:0% +an integer it gives me just the number +three right and we can wrap each of + + align:start position:0% +three right and we can wrap each of + + + align:start position:0% +three right and we can wrap each of +these in a type command to see the Act + + align:start position:0% +these in a type command to see the Act + + + align:start position:0% +these in a type command to see the Act +exact type but we can tell right + + align:start position:0% +exact type but we can tell right + + + align:start position:0% +exact type but we can tell right +away so if we do f+ G multiplied by int + + align:start position:0% +away so if we do f+ G multiplied by int + + + align:start position:0% +away so if we do f+ G multiplied by int +of three or sorry oops int of H right + + align:start position:0% +of three or sorry oops int of H right + + + align:start position:0% +of three or sorry oops int of H right +which is just a three it's going to + + align:start position:0% +which is just a three it's going to + + + align:start position:0% +which is just a three it's going to +repeat a space b three times right so + + align:start position:0% +repeat a space b three times right so + + + align:start position:0% +repeat a space b three times right so +there's one there's two and there's + + align:start position:0% +there's one there's two and there's + + + align:start position:0% +there's one there's two and there's +three what would have happened if I + + align:start position:0% +three what would have happened if I + + + align:start position:0% +three what would have happened if I +forgot to cast it to an integer what do + + align:start position:0% +forgot to cast it to an integer what do + + + align:start position:0% +forgot to cast it to an integer what do +you + + align:start position:0% +you + + + align:start position:0% +you +think if I just did H an error yeah + + align:start position:0% +think if I just did H an error yeah + + + align:start position:0% +think if I just did H an error yeah +exactly they're not scary they're kind + + align:start position:0% +exactly they're not scary they're kind + + + align:start position:0% +exactly they're not scary they're kind +of informative once you get to know them + + align:start position:0% +of informative once you get to know them + + + align:start position:0% +of informative once you get to know them +so it's a type error yeah something's + + align:start position:0% +so it's a type error yeah something's + + + align:start position:0% +so it's a type error yeah something's +wrong with our types can't multiply a + + align:start position:0% +wrong with our types can't multiply a + + + align:start position:0% +wrong with our types can't multiply a +sequence so an integer or a string uh a + + align:start position:0% +sequence so an integer or a string uh a + + + align:start position:0% +sequence so an integer or a string uh a +sequence by a non- + + align:start position:0% +sequence by a non- + + + align:start position:0% +sequence by a non- +integer right + + align:start position:0% + + + + align:start position:0% + +okay so what are some other operations + + align:start position:0% +okay so what are some other operations + + + align:start position:0% +okay so what are some other operations +we can do with strings there's some + + align:start position:0% +we can do with strings there's some + + + align:start position:0% +we can do with strings there's some +different things we can do with strings + + align:start position:0% +different things we can do with strings + + + align:start position:0% +different things we can do with strings +that we actually haven't seen uh with uh + + align:start position:0% +that we actually haven't seen uh with uh + + + align:start position:0% +that we actually haven't seen uh with uh +with numbers uh in last lecture one of + + align:start position:0% +with numbers uh in last lecture one of + + + align:start position:0% +with numbers uh in last lecture one of +the more common operations is to get the + + align:start position:0% +the more common operations is to get the + + + align:start position:0% +the more common operations is to get the +length of a string so this tells us how + + align:start position:0% +length of a string so this tells us how + + + align:start position:0% +length of a string so this tells us how +many characters are in the string so if + + align:start position:0% +many characters are in the string so if + + + align:start position:0% +many characters are in the string so if +we say s is equal to ABC here I'm + + align:start position:0% +we say s is equal to ABC here I'm + + + align:start position:0% +we say s is equal to ABC here I'm +creating a string uh with characters a b + + align:start position:0% +creating a string uh with characters a b + + + align:start position:0% +creating a string uh with characters a b +and c and I'm giving it the name s now + + align:start position:0% +and c and I'm giving it the name s now + + + align:start position:0% +and c and I'm giving it the name s now +anytime in my program when I say s + + align:start position:0% +anytime in my program when I say s + + + align:start position:0% +anytime in my program when I say s +python will replace that with this + + align:start position:0% +python will replace that with this + + + align:start position:0% +python will replace that with this +string of characters ABC I can wrap s in + + align:start position:0% +string of characters ABC I can wrap s in + + + align:start position:0% +string of characters ABC I can wrap s in +this Len command and this Len command is + + align:start position:0% +this Len command and this Len command is + + + align:start position:0% +this Len command and this Len command is +is an expression basically python reads + + align:start position:0% +is an expression basically python reads + + + align:start position:0% +is an expression basically python reads +this and it evaluates it to one value so + + align:start position:0% +this and it evaluates it to one value so + + + align:start position:0% +this and it evaluates it to one value so +replaces this expression with one value + + align:start position:0% +replaces this expression with one value + + + align:start position:0% +replaces this expression with one value +how many characters are in my string so + + align:start position:0% +how many characters are in my string so + + + align:start position:0% +how many characters are in my string so +Len s will basically become the number + + align:start position:0% +Len s will basically become the number + + + align:start position:0% +Len s will basically become the number +three so in my program I can say + + align:start position:0% +three so in my program I can say + + + align:start position:0% +three so in my program I can say +something like another assignment + + align:start position:0% +something like another assignment + + + align:start position:0% +something like another assignment +statement down here right chariz is is + + align:start position:0% +statement down here right chariz is is + + + align:start position:0% +statement down here right chariz is is +equal to lens s this is an expression + + align:start position:0% +equal to lens s this is an expression + + + align:start position:0% +equal to lens s this is an expression +right like in the previous line that + + align:start position:0% +right like in the previous line that + + + align:start position:0% +right like in the previous line that +evaluates to three so basically this + + align:start position:0% +evaluates to three so basically this + + + align:start position:0% +evaluates to three so basically this +line says chars is equal to + + align:start position:0% +line says chars is equal to + + + align:start position:0% +line says chars is equal to +three + + align:start position:0% +three + + + align:start position:0% +three +right okay that's a pretty simple + + align:start position:0% +right okay that's a pretty simple + + + align:start position:0% +right okay that's a pretty simple +operation with strings now we're going + + align:start position:0% +operation with strings now we're going + + + align:start position:0% +operation with strings now we're going +to get into a little bit more uh uh + + align:start position:0% +to get into a little bit more uh uh + + + align:start position:0% +to get into a little bit more uh uh +detailed ones that requires you to kind + + align:start position:0% +detailed ones that requires you to kind + + + align:start position:0% +detailed ones that requires you to kind +of remember this python syntax so one + + align:start position:0% +of remember this python syntax so one + + + align:start position:0% +of remember this python syntax so one +thing we can do with strings is we can + + align:start position:0% +thing we can do with strings is we can + + + align:start position:0% +thing we can do with strings is we can +grab individual characters at different + + align:start position:0% +grab individual characters at different + + + align:start position:0% +grab individual characters at different +positions so that's called + + align:start position:0% +positions so that's called + + + align:start position:0% +positions so that's called +slicing the syntax or the way that we + + align:start position:0% +slicing the syntax or the way that we + + + align:start position:0% +slicing the syntax or the way that we +actually do this in Python is using + + align:start position:0% +actually do this in Python is using + + + align:start position:0% +actually do this in Python is using +square brackets so you can see this here + + align:start position:0% +square brackets so you can see this here + + + align:start position:0% +square brackets so you can see this here +right we have some square bracket + + align:start position:0% +right we have some square bracket + + + align:start position:0% +right we have some square bracket +notation and this is just how python + + align:start position:0% +notation and this is just how python + + + align:start position:0% +notation and this is just how python +does it so if we have string s is equal + + align:start position:0% +does it so if we have string s is equal + + + align:start position:0% +does it so if we have string s is equal +to the characters + + align:start position:0% +to the characters + + + align:start position:0% +to the characters +ABC The Way We Tell python we'd like to + + align:start position:0% +ABC The Way We Tell python we'd like to + + + align:start position:0% +ABC The Way We Tell python we'd like to +extract a character at a particular + + align:start position:0% +extract a character at a particular + + + align:start position:0% +extract a character at a particular +position is by indexing into that + + align:start position:0% +position is by indexing into that + + + align:start position:0% +position is by indexing into that +string now in Python and modern + + align:start position:0% +string now in Python and modern + + + align:start position:0% +string now in Python and modern +programming languages indexing happens + + align:start position:0% +programming languages indexing happens + + + align:start position:0% +programming languages indexing happens +from zero we count from zero in + + align:start position:0% +from zero we count from zero in + + + align:start position:0% +from zero we count from zero in +programming okay in computer science so + + align:start position:0% +programming okay in computer science so + + + align:start position:0% +programming okay in computer science so +what that means is the + + align:start position:0% +what that means is the + + + align:start position:0% +what that means is the +index of the first character the index + + align:start position:0% +index of the first character the index + + + align:start position:0% +index of the first character the index +of a is zero the index of B is one and + + align:start position:0% +of a is zero the index of B is one and + + + align:start position:0% +of a is zero the index of B is one and +the index of C is two right so we can + + align:start position:0% +the index of C is two right so we can + + + align:start position:0% +the index of C is two right so we can +say the what's the character at the + + align:start position:0% +say the what's the character at the + + + align:start position:0% +say the what's the character at the +first position or the first location but + + align:start position:0% +first position or the first location but + + + align:start position:0% +first position or the first location but +in computer science speak we say that's + + align:start position:0% +in computer science speak we say that's + + + align:start position:0% +in computer science speak we say that's +the character at index zero the + + align:start position:0% +the character at index zero the + + + align:start position:0% +the character at index zero the +character at index one is the is the + + align:start position:0% +character at index one is the is the + + + align:start position:0% +character at index one is the is the +character location to and so on right so + + align:start position:0% +character location to and so on right so + + + align:start position:0% +character location to and so on right so +when we're indexing into a string we're + + align:start position:0% +when we're indexing into a string we're + + + align:start position:0% +when we're indexing into a string we're +always starting to count from + + align:start position:0% +always starting to count from + + + align:start position:0% +always starting to count from +zero so s at index zero uh that's how we + + align:start position:0% +zero so s at index zero uh that's how we + + + align:start position:0% +zero so s at index zero uh that's how we +call this line here is another python + + align:start position:0% +call this line here is another python + + + align:start position:0% +call this line here is another python +expression it just has uh it just looks + + align:start position:0% +expression it just has uh it just looks + + + align:start position:0% +expression it just has uh it just looks +different than the Expressions we've + + align:start position:0% +different than the Expressions we've + + + align:start position:0% +different than the Expressions we've +seen so far but this entire expression + + align:start position:0% +seen so far but this entire expression + + + align:start position:0% +seen so far but this entire expression +python evaluates to a particular value + + align:start position:0% +python evaluates to a particular value + + + align:start position:0% +python evaluates to a particular value +and the value it evaluates it to is the + + align:start position:0% +and the value it evaluates it to is the + + + align:start position:0% +and the value it evaluates it to is the +character at that index so just to show + + align:start position:0% +character at that index so just to show + + + align:start position:0% +character at that index so just to show +you kind of what that looks like in here + + align:start position:0% +you kind of what that looks like in here + + + align:start position:0% +you kind of what that looks like in here +if s is equal to ABC all we would type + + align:start position:0% +if s is equal to ABC all we would type + + + align:start position:0% +if s is equal to ABC all we would type +is this s at index zero and this + + align:start position:0% +is this s at index zero and this + + + align:start position:0% +is this s at index zero and this +expression evaluates to that Single + + align:start position:0% +expression evaluates to that Single + + + align:start position:0% +expression evaluates to that Single +Character a okay s at index one b s at + + align:start position:0% +Character a okay s at index one b s at + + + align:start position:0% +Character a okay s at index one b s at +index 2 c s set index + + align:start position:0% +index 2 c s set index + + + align:start position:0% +index 2 c s set index +3 basically says what is the character + + align:start position:0% +3 basically says what is the character + + + align:start position:0% +3 basically says what is the character +at the fourth position well ABC only has + + align:start position:0% +at the fourth position well ABC only has + + + align:start position:0% +at the fourth position well ABC only has +three positions so this will actually + + align:start position:0% +three positions so this will actually + + + align:start position:0% +three positions so this will actually +give us our second error of the class an + + align:start position:0% +give us our second error of the class an + + + align:start position:0% +give us our second error of the class an +index error this is a pretty common + + align:start position:0% +index error this is a pretty common + + + align:start position:0% +index error this is a pretty common +error as we start working with more + + align:start position:0% +error as we start working with more + + + align:start position:0% +error as we start working with more +complex programs it basically means + + align:start position:0% +complex programs it basically means + + + align:start position:0% +complex programs it basically means +you've indexed too far into the list + + align:start position:0% +you've indexed too far into the list + + + align:start position:0% +you've indexed too far into the list +either to the right or to the + + align:start position:0% + + + + align:start position:0% + +left you can index into a list with + + align:start position:0% +left you can index into a list with + + + align:start position:0% +left you can index into a list with +negative indices as well so if you ever + + align:start position:0% +negative indices as well so if you ever + + + align:start position:0% +negative indices as well so if you ever +want to grab the character at the last + + align:start position:0% +want to grab the character at the last + + + align:start position:0% +want to grab the character at the last +position so at the rightmost place + + align:start position:0% +position so at the rightmost place + + + align:start position:0% +position so at the rightmost place +that's the character at index negative 1 + + align:start position:0% +that's the character at index negative 1 + + + align:start position:0% +that's the character at index negative 1 +it's a really convenient way to grab + + align:start position:0% +it's a really convenient way to grab + + + align:start position:0% +it's a really convenient way to grab +that last character you basically ask + + align:start position:0% +that last character you basically ask + + + align:start position:0% +that last character you basically ask +what's s at1 and python automatically + + align:start position:0% +what's s at1 and python automatically + + + align:start position:0% +what's s at1 and python automatically +grabs for us that last character so we + + align:start position:0% +grabs for us that last character so we + + + align:start position:0% +grabs for us that last character so we +don't have to use an expression sort of + + align:start position:0% +don't have to use an expression sort of + + + align:start position:0% +don't have to use an expression sort of +like Len of + + align:start position:0% +like Len of + + + align:start position:0% +like Len of +S1 right that would be c as well and + + align:start position:0% +S1 right that would be c as well and + + + align:start position:0% +S1 right that would be c as well and +here I've inserted an expression lens s + + align:start position:0% +here I've inserted an expression lens s + + + align:start position:0% +here I've inserted an expression lens s +minus one directly in that index and + + align:start position:0% +minus one directly in that index and + + + align:start position:0% +minus one directly in that index and +that's totally fine again python + + align:start position:0% +that's totally fine again python + + + align:start position:0% +that's totally fine again python +evaluates things in to out left to right + + align:start position:0% +evaluates things in to out left to right + + + align:start position:0% +evaluates things in to out left to right +it evaluated Len s minus one to be two + + align:start position:0% +it evaluated Len s minus one to be two + + + align:start position:0% +it evaluated Len s minus one to be two +and basically this line became what s at + + align:start position:0% +and basically this line became what s at + + + align:start position:0% +and basically this line became what s at +index 2 which we knew was + + align:start position:0% + + + + align:start position:0% + +c c uh because when you index into + + align:start position:0% +c c uh because when you index into + + + align:start position:0% +c c uh because when you index into +negative numbers the we start counting + + align:start position:0% +negative numbers the we start counting + + + align:start position:0% +negative numbers the we start counting +from the right hand side just python + + align:start position:0% +from the right hand side just python + + + align:start position:0% +from the right hand side just python +convention + + align:start position:0% + + + + align:start position:0% + +yeah and so s at -4 will give us an + + align:start position:0% +yeah and so s at -4 will give us an + + + align:start position:0% +yeah and so s at -4 will give us an +error as well because now we're indexing + + align:start position:0% +error as well because now we're indexing + + + align:start position:0% +error as well because now we're indexing +too far to the left there's nothing + + align:start position:0% +too far to the left there's nothing + + + align:start position:0% +too far to the left there's nothing +there okay so we can index to get single + + align:start position:0% +there okay so we can index to get single + + + align:start position:0% +there okay so we can index to get single +characters that's fine we just use + + align:start position:0% +characters that's fine we just use + + + align:start position:0% +characters that's fine we just use +square bracket and say the index that + + align:start position:0% +square bracket and say the index that + + + align:start position:0% +square bracket and say the index that +we'd like to get the character at we can + + align:start position:0% +we'd like to get the character at we can + + + align:start position:0% +we'd like to get the character at we can +also slice to get substrings so instead + + align:start position:0% +also slice to get substrings so instead + + + align:start position:0% +also slice to get substrings so instead +of getting single characters we can ask + + align:start position:0% +of getting single characters we can ask + + + align:start position:0% +of getting single characters we can ask +python to get us a substring starting + + align:start position:0% +python to get us a substring starting + + + align:start position:0% +python to get us a substring starting +from one index going up to some other + + align:start position:0% +from one index going up to some other + + + align:start position:0% +from one index going up to some other +index and potentially skipping + + align:start position:0% +index and potentially skipping + + + align:start position:0% +index and potentially skipping +characters you can take every character + + align:start position:0% +characters you can take every character + + + align:start position:0% +characters you can take every character +along the way you can skip every other + + align:start position:0% +along the way you can skip every other + + + align:start position:0% +along the way you can skip every other +character or some other um you know some + + align:start position:0% +character or some other um you know some + + + align:start position:0% +character or some other um you know some +other uh pattern like + + align:start position:0% +other uh pattern like + + + align:start position:0% +other uh pattern like +that the syntax for that is similar to + + align:start position:0% +that the syntax for that is similar to + + + align:start position:0% +that the syntax for that is similar to +slicing to get a A Single Character + + align:start position:0% +slicing to get a A Single Character + + + align:start position:0% +slicing to get a A Single Character +slightly different though it's similar + + align:start position:0% +slightly different though it's similar + + + align:start position:0% +slightly different though it's similar +in that we have square brackets + + align:start position:0% +in that we have square brackets + + + align:start position:0% +in that we have square brackets +involved slightly different because now + + align:start position:0% +involved slightly different because now + + + align:start position:0% +involved slightly different because now +we have to give three numbers within + + align:start position:0% +we have to give three numbers within + + + align:start position:0% +we have to give three numbers within +those square + + align:start position:0% +those square + + + align:start position:0% +those square +brackets separated by + + align:start position:0% +brackets separated by + + + align:start position:0% +brackets separated by +colons the first number number will + + align:start position:0% +colons the first number number will + + + align:start position:0% +colons the first number number will +represent what's the start index so + + align:start position:0% +represent what's the start index so + + + align:start position:0% +represent what's the start index so +where do you want to start your + + align:start position:0% +where do you want to start your + + + align:start position:0% +where do you want to start your +substring from the second is what's the + + align:start position:0% +substring from the second is what's the + + + align:start position:0% +substring from the second is what's the +stop index so we're going to take every + + align:start position:0% +stop index so we're going to take every + + + align:start position:0% +stop index so we're going to take every +character from that start index going + + align:start position:0% +character from that start index going + + + align:start position:0% +character from that start index going +all the way up to but not including the + + align:start position:0% +all the way up to but not including the + + + align:start position:0% +all the way up to but not including the +stop okay and the step means how many + + align:start position:0% +stop okay and the step means how many + + + align:start position:0% +stop okay and the step means how many +characters do we skip so if the step is + + align:start position:0% +characters do we skip so if the step is + + + align:start position:0% +characters do we skip so if the step is +one we're taking every character if the + + align:start position:0% +one we're taking every character if the + + + align:start position:0% +one we're taking every character if the +step is two we'll take every other + + align:start position:0% +step is two we'll take every other + + + align:start position:0% +step is two we'll take every other +character the step is three we skip + + align:start position:0% +character the step is three we skip + + + align:start position:0% +character the step is three we skip +every uh every two characters and so on + + align:start position:0% +every uh every two characters and so on + + + align:start position:0% +every uh every two characters and so on +now there's a bunch of combinations we + + align:start position:0% +now there's a bunch of combinations we + + + align:start position:0% +now there's a bunch of combinations we +can do within these uh with these three + + align:start position:0% +can do within these uh with these three + + + align:start position:0% +can do within these uh with these three +um three numbers within the square + + align:start position:0% +um three numbers within the square + + + align:start position:0% +um three numbers within the square +brackets uh that you'll you know as you + + align:start position:0% +brackets uh that you'll you know as you + + + align:start position:0% +brackets uh that you'll you know as you +work with these with these exercises um + + align:start position:0% +work with these with these exercises um + + + align:start position:0% +work with these with these exercises um +you'll sort of get the hang of for now + + align:start position:0% +you'll sort of get the hang of for now + + + align:start position:0% +you'll sort of get the hang of for now +it won't hurt to always give it a start + + align:start position:0% +it won't hurt to always give it a start + + + align:start position:0% +it won't hurt to always give it a start +a stop and a step that's perfectly fine + + align:start position:0% +a stop and a step that's perfectly fine + + + align:start position:0% +a stop and a step that's perfectly fine +but something that's really common if + + align:start position:0% +but something that's really common if + + + align:start position:0% +but something that's really common if +you're always going to take every single + + align:start position:0% +you're always going to take every single + + + align:start position:0% +you're always going to take every single +character is to just omit the step part + + align:start position:0% +character is to just omit the step part + + + align:start position:0% +character is to just omit the step part +so if you just give it two numbers + + align:start position:0% +so if you just give it two numbers + + + align:start position:0% +so if you just give it two numbers +number colon number python automatically + + align:start position:0% +number colon number python automatically + + + align:start position:0% +number colon number python automatically +knows that your step will be one by + + align:start position:0% +knows that your step will be one by + + + align:start position:0% +knows that your step will be one by +default so you're not skipping anything + + align:start position:0% +default so you're not skipping anything + + + align:start position:0% +default so you're not skipping anything +okay if you're just giving it one number + + align:start position:0% +okay if you're just giving it one number + + + align:start position:0% +okay if you're just giving it one number +no colons we back to the previous slide + + align:start position:0% +no colons we back to the previous slide + + + align:start position:0% +no colons we back to the previous slide +right where we're just grabbing one + + align:start position:0% +right where we're just grabbing one + + + align:start position:0% +right where we're just grabbing one +element and I know this is going to be a + + align:start position:0% +element and I know this is going to be a + + + align:start position:0% +element and I know this is going to be a +little confusing we're going to look at + + align:start position:0% +little confusing we're going to look at + + + align:start position:0% +little confusing we're going to look at +an example on the next slide but this is + + align:start position:0% +an example on the next slide but this is + + + align:start position:0% +an example on the next slide but this is +something you'll just have to practice a + + align:start position:0% +something you'll just have to practice a + + + align:start position:0% +something you'll just have to practice a +little bit on the shell um with the + + align:start position:0% +little bit on the shell um with the + + + align:start position:0% +little bit on the shell um with the +following example hopefully just you + + align:start position:0% +following example hopefully just you + + + align:start position:0% +following example hopefully just you +know just when you go home um just to + + align:start position:0% +know just when you go home um just to + + + align:start position:0% +know just when you go home um just to +kind of make sure that you understand + + align:start position:0% +kind of make sure that you understand + + + align:start position:0% +kind of make sure that you understand +what it's doing if you're have a + + align:start position:0% +what it's doing if you're have a + + + align:start position:0% +what it's doing if you're have a +question like what if I put in this + + align:start position:0% +question like what if I put in this + + + align:start position:0% +question like what if I put in this +number or this number just put it in the + + align:start position:0% +number or this number just put it in the + + + align:start position:0% +number or this number just put it in the +shell and see what happens + + align:start position:0% +shell and see what happens + + + align:start position:0% +shell and see what happens +so let's take a look at a couple of + + align:start position:0% +so let's take a look at a couple of + + + align:start position:0% +so let's take a look at a couple of +examples so how do we slice to get + + align:start position:0% +examples so how do we slice to get + + + align:start position:0% +examples so how do we slice to get +substrings let's say our string is this + + align:start position:0% +substrings let's say our string is this + + + align:start position:0% +substrings let's say our string is this +longer thing a b CDE E F G H when we + + align:start position:0% +longer thing a b CDE E F G H when we + + + align:start position:0% +longer thing a b CDE E F G H when we +slice the first thing we want to look at + + align:start position:0% +slice the first thing we want to look at + + + align:start position:0% +slice the first thing we want to look at +is the step is it positive or negative + + align:start position:0% +is the step is it positive or negative + + + align:start position:0% +is the step is it positive or negative +if it's positive and remember if you + + align:start position:0% +if it's positive and remember if you + + + align:start position:0% +if it's positive and remember if you +omit it by default it's plus one so if + + align:start position:0% +omit it by default it's plus one so if + + + align:start position:0% +omit it by default it's plus one so if +it's positive we're going to work our + + align:start position:0% +it's positive we're going to work our + + + align:start position:0% +it's positive we're going to work our +way left to right right the way we read + + align:start position:0% +way left to right right the way we read + + + align:start position:0% +way left to right right the way we read +if it's negative we're going to work our + + align:start position:0% +if it's negative we're going to work our + + + align:start position:0% +if it's negative we're going to work our +way right to left + + align:start position:0% +way right to left + + + align:start position:0% +way right to left +so what if we index s from 3 colum 6 the + + align:start position:0% +so what if we index s from 3 colum 6 the + + + align:start position:0% +so what if we index s from 3 colum 6 the +step is positive one so we're going to + + align:start position:0% +step is positive one so we're going to + + + align:start position:0% +step is positive one so we're going to +work our way left to right so that means + + align:start position:0% +work our way left to right so that means + + + align:start position:0% +work our way left to right so that means +we're going to start at index three so + + align:start position:0% +we're going to start at index three so + + + align:start position:0% +we're going to start at index three so +that's the D so we're going to grab the + + align:start position:0% +that's the D so we're going to grab the + + + align:start position:0% +that's the D so we're going to grab the +D and we're going to go up to get the + + align:start position:0% +D and we're going to go up to get the + + + align:start position:0% +D and we're going to go up to get the +substring from D up to but not including + + align:start position:0% +substring from D up to but not including + + + align:start position:0% +substring from D up to but not including +the character at index + + align:start position:0% +the character at index + + + align:start position:0% +the character at index +six the H the G sorry the g okay so the + + align:start position:0% +six the H the G sorry the g okay so the + + + align:start position:0% +six the H the G sorry the g okay so the +characters we're going to grab are the D + + align:start position:0% +characters we're going to grab are the D + + + align:start position:0% +characters we're going to grab are the D +the E and the F right we started step + + align:start position:0% +the E and the F right we started step + + + align:start position:0% +the E and the F right we started step +three we go up to but not including six + + align:start position:0% +three we go up to but not including six + + + align:start position:0% +three we go up to but not including six +taking every character because the step + + align:start position:0% +taking every character because the step + + + align:start position:0% +taking every character because the step +is + + align:start position:0% +is + + + align:start position:0% +is +one what if the step was two so same + + align:start position:0% +one what if the step was two so same + + + align:start position:0% +one what if the step was two so same +thing as we just did except the step is + + align:start position:0% +thing as we just did except the step is + + + align:start position:0% +thing as we just did except the step is +two again the step is positive so we're + + align:start position:0% +two again the step is positive so we're + + + align:start position:0% +two again the step is positive so we're +going to work work our way left to right + + align:start position:0% +going to work work our way left to right + + + align:start position:0% +going to work work our way left to right +we're going to start at index three so + + align:start position:0% +we're going to start at index three so + + + align:start position:0% +we're going to start at index three so +we're going to grab the D and we're + + align:start position:0% +we're going to grab the D and we're + + + align:start position:0% +we're going to grab the D and we're +going to create a new object which is + + align:start position:0% +going to create a new object which is + + + align:start position:0% +going to create a new object which is +going to be the the characters D we're + + align:start position:0% +going to be the the characters D we're + + + align:start position:0% +going to be the the characters D we're +going to skip the E because the step is + + align:start position:0% +going to skip the E because the step is + + + align:start position:0% +going to skip the E because the step is +two take the + + align:start position:0% +two take the + + + align:start position:0% +two take the +F and that's it we've worked our way up + + align:start position:0% +F and that's it we've worked our way up + + + align:start position:0% +F and that's it we've worked our way up +to but not not including the element at + + align:start position:0% +to but not not including the element at + + + align:start position:0% +to but not not including the element at +index + + align:start position:0% + + + + align:start position:0% + +six there are some other things uh uh I + + align:start position:0% +six there are some other things uh uh I + + + align:start position:0% +six there are some other things uh uh I +guess tricks or you might want to call + + align:start position:0% +guess tricks or you might want to call + + + align:start position:0% +guess tricks or you might want to call +them that you can do so if we just put + + align:start position:0% +them that you can do so if we just put + + + align:start position:0% +them that you can do so if we just put +an empty colon here that says just make + + align:start position:0% +an empty colon here that says just make + + + align:start position:0% +an empty colon here that says just make +the same object again so that will + + align:start position:0% +the same object again so that will + + + align:start position:0% +the same object again so that will +evaluate to just ABCD E F G + + align:start position:0% +evaluate to just ABCD E F G + + + align:start position:0% +evaluate to just ABCD E F G +again if we do colon + + align:start position:0% +again if we do colon + + + align:start position:0% +again if we do colon +colon1 this is shorthand notation for + + align:start position:0% +colon1 this is shorthand notation for + + + align:start position:0% +colon1 this is shorthand notation for +basically grabbing for me the string + + align:start position:0% +basically grabbing for me the string + + + align:start position:0% +basically grabbing for me the string +backward so h g f e d c b a right just + + align:start position:0% +backward so h g f e d c b a right just + + + align:start position:0% +backward so h g f e d c b a right just +make the same string as the original one + + align:start position:0% +make the same string as the original one + + + align:start position:0% +make the same string as the original one +but + + align:start position:0% +but + + + align:start position:0% +but +backward and we can do something like + + align:start position:0% +backward and we can do something like + + + align:start position:0% +backward and we can do something like +this for one with a step + + align:start position:0% +this for one with a step + + + align:start position:0% +this for one with a step +-2 now the step is negative right so + + align:start position:0% +-2 now the step is negative right so + + + align:start position:0% +-2 now the step is negative right so +that means we're going to work our way + + align:start position:0% +that means we're going to work our way + + + align:start position:0% +that means we're going to work our way +right to left we're going to start at + + align:start position:0% +right to left we're going to start at + + + align:start position:0% +right to left we're going to start at +index 4 so we're going to grab the + + align:start position:0% +index 4 so we're going to grab the + + + align:start position:0% +index 4 so we're going to grab the +E we're going to skip every other + + align:start position:0% +E we're going to skip every other + + + align:start position:0% +E we're going to skip every other +character so we're not going to take the + + align:start position:0% +character so we're not going to take the + + + align:start position:0% +character so we're not going to take the +d but we will take the C and we're going + + align:start position:0% +d but we will take the C and we're going + + + align:start position:0% +d but we will take the C and we're going +to go down to but not including the + + align:start position:0% +to go down to but not including the + + + align:start position:0% +to go down to but not including the +character at index one so we're going to + + align:start position:0% +character at index one so we're going to + + + align:start position:0% +character at index one so we're going to +stop right here so the characters we + + align:start position:0% +stop right here so the characters we + + + align:start position:0% +stop right here so the characters we +took in this order were e and then C so + + align:start position:0% +took in this order were e and then C so + + + align:start position:0% +took in this order were e and then C so +this entire expression evaluates to + + align:start position:0% + + + + align:start position:0% + +EC yes question we D why did we skip D + + align:start position:0% +EC yes question we D why did we skip D + + + align:start position:0% +EC yes question we D why did we skip D +because the step is two so when the step + + align:start position:0% +because the step is two so when the step + + + align:start position:0% +because the step is two so when the step +is one we take every character the step + + align:start position:0% +is one we take every character the step + + + align:start position:0% +is one we take every character the step +is two skip every other one yeah for the + + align:start position:0% +is two skip every other one yeah for the + + + align:start position:0% +is two skip every other one yeah for the +first one S3 to why is G not included G + + align:start position:0% +first one S3 to why is G not included G + + + align:start position:0% +first one S3 to why is G not included G +is not included just by definition we go + + align:start position:0% +is not included just by definition we go + + + align:start position:0% +is not included just by definition we go +up to but not including the stop so + + align:start position:0% +up to but not including the stop so + + + align:start position:0% +up to but not including the stop so +we'll go up to but not including the the + + align:start position:0% +we'll go up to but not including the the + + + align:start position:0% +we'll go up to but not including the the +character at index + + align:start position:0% +character at index + + + align:start position:0% +character at index +six that's just the definition of + + align:start position:0% +six that's just the definition of + + + align:start position:0% +six that's just the definition of +slicing in + + align:start position:0% + + + + align:start position:0% + +Python so up to an including stop minus + + align:start position:0% +Python so up to an including stop minus + + + align:start position:0% +Python so up to an including stop minus +one means we go up to an including five + + align:start position:0% +one means we go up to an including five + + + align:start position:0% +one means we go up to an including five +right yeah exactly yep + + align:start position:0% + + + + align:start position:0% + +okay so again if you're unsure what a + + align:start position:0% +okay so again if you're unsure what a + + + align:start position:0% +okay so again if you're unsure what a +com a command does always try you can + + align:start position:0% +com a command does always try you can + + + align:start position:0% +com a command does always try you can +always try it in your console right the + + align:start position:0% +always try it in your console right the + + + align:start position:0% +always try it in your console right the +shell and um here's an opportunity to do + + align:start position:0% +shell and um here's an opportunity to do + + + align:start position:0% +shell and um here's an opportunity to do +that so here's a string s + + align:start position:0% +that so here's a string s + + + align:start position:0% +that so here's a string s +ABC d3f and I'm actually going to write + + align:start position:0% +ABC d3f and I'm actually going to write + + + align:start position:0% +ABC d3f and I'm actually going to write +this one down just ABC space right + + align:start position:0% +this one down just ABC space right + + + align:start position:0% +this one down just ABC space right +there's a space here 3D what I do or d3f + + align:start position:0% + + + + align:start position:0% + +and then another space and + + align:start position:0% + + + + align:start position:0% + +ghi so what do you guys think the first + + align:start position:0% +ghi so what do you guys think the first + + + align:start position:0% +ghi so what do you guys think the first +one will be three colon Len s minus one + + align:start position:0% +one will be three colon Len s minus one + + + align:start position:0% +one will be three colon Len s minus one +I'll even do the indices here for + + align:start position:0% + + + + align:start position:0% + +you what's the + + align:start position:0% + + + + align:start position:0% + +start yeah the space exactly so it's + + align:start position:0% +start yeah the space exactly so it's + + + align:start position:0% +start yeah the space exactly so it's +going to be a little space + + align:start position:0% +going to be a little space + + + align:start position:0% +going to be a little space +what is len s minus + + align:start position:0% + + + + align:start position:0% + +one 10 yeah what's the length how many + + align:start position:0% +one 10 yeah what's the length how many + + + align:start position:0% +one 10 yeah what's the length how many +characters are in here 11 yep and - one + + align:start position:0% +characters are in here 11 yep and - one + + + align:start position:0% +characters are in here 11 yep and - one +is 10 so when we do this when the stop + + align:start position:0% +is 10 so when we do this when the stop + + + align:start position:0% +is 10 so when we do this when the stop +is 10 that means we're going to go up to + + align:start position:0% +is 10 that means we're going to go up to + + + align:start position:0% +is 10 that means we're going to go up to +but not including the character at 10 so + + align:start position:0% +but not including the character at 10 so + + + align:start position:0% +but not including the character at 10 so +we're going to go up to this H right so + + align:start position:0% +we're going to go up to this H right so + + + align:start position:0% +we're going to go up to this H right so +we're going to take the space d 3 f + + align:start position:0% +we're going to take the space d 3 f + + + align:start position:0% +we're going to take the space d 3 f +space g h and we + + align:start position:0% +space g h and we + + + align:start position:0% +space g h and we +stop yeah why do we start at zero again + + align:start position:0% +stop yeah why do we start at zero again + + + align:start position:0% +stop yeah why do we start at zero again +convention computer science + + align:start position:0% +convention computer science + + + align:start position:0% +convention computer science +programming except for mat lab I think + + align:start position:0% +programming except for mat lab I think + + + align:start position:0% +programming except for mat lab I think +they still start indexing it + + align:start position:0% +they still start indexing it + + + align:start position:0% +they still start indexing it +one other questions about this one is + + align:start position:0% +one other questions about this one is + + + align:start position:0% +one other questions about this one is +that all + + align:start position:0% +that all + + + align:start position:0% +that all +right okay how about the next one S4 + + align:start position:0% +right okay how about the next one S4 + + + align:start position:0% +right okay how about the next one S4 +colon Z colon negative 1 what's the + + align:start position:0% +colon Z colon negative 1 what's the + + + align:start position:0% +colon Z colon negative 1 what's the +element at index four + + align:start position:0% + + + + align:start position:0% + +the D yep so we're going to grab the + + align:start position:0% +the D yep so we're going to grab the + + + align:start position:0% +the D yep so we're going to grab the +D are we working our way right or to the + + align:start position:0% +D are we working our way right or to the + + + align:start position:0% +D are we working our way right or to the +right or to the left yeah exactly so + + align:start position:0% +right or to the left yeah exactly so + + + align:start position:0% +right or to the left yeah exactly so +we're going to go up to but not + + align:start position:0% +we're going to go up to but not + + + align:start position:0% +we're going to go up to but not +including the character index zero so + + align:start position:0% +including the character index zero so + + + align:start position:0% +including the character index zero so +we're going to get the D the space it's + + align:start position:0% +we're going to get the D the space it's + + + align:start position:0% +we're going to get the D the space it's +the C the + + align:start position:0% +the C the + + + align:start position:0% +the C the +B am I taking the a no exactly so that's + + align:start position:0% +B am I taking the a no exactly so that's + + + align:start position:0% +B am I taking the a no exactly so that's +it d space + + align:start position:0% +it d space + + + align:start position:0% +it d space +CB yes want to include the a would uh + + align:start position:0% +CB yes want to include the a would uh + + + align:start position:0% +CB yes want to include the a would uh +the second value + + align:start position:0% +the second value + + + align:start position:0% +the second value +if you did want to include the a + + align:start position:0% +if you did want to include the a + + + align:start position:0% +if you did want to include the a +actually you would want to do something + + align:start position:0% +actually you would want to do something + + + align:start position:0% +actually you would want to do something +different I think it you can't go to + + align:start position:0% +different I think it you can't go to + + + align:start position:0% +different I think it you can't go to +negative one because negative one is + + align:start position:0% +negative one because negative one is + + + align:start position:0% +negative one because negative one is +actually this right here that's a good + + align:start position:0% +actually this right here that's a good + + + align:start position:0% +actually this right here that's a good +question I'd have to try it out um play + + align:start position:0% +question I'd have to try it out um play + + + align:start position:0% +question I'd have to try it out um play +around with it but if you want to + + align:start position:0% +around with it but if you want to + + + align:start position:0% +around with it but if you want to +include it I think maybe you would just + + align:start position:0% +include it I think maybe you would just + + + align:start position:0% +include it I think maybe you would just +do an empty sorry go + + align:start position:0% +do an empty sorry go + + + align:start position:0% +do an empty sorry go +ahead you just probably do an empty + + align:start position:0% +ahead you just probably do an empty + + + align:start position:0% +ahead you just probably do an empty +colon and by default that means the + + align:start position:0% +colon and by default that means the + + + align:start position:0% +colon and by default that means the +beginning + + align:start position:0% +beginning + + + align:start position:0% +beginning +but I'd have to try it out + + align:start position:0% +but I'd have to try it out + + + align:start position:0% +but I'd have to try it out +yeah how about the last one uh six colon + + align:start position:0% +yeah how about the last one uh six colon + + + align:start position:0% +yeah how about the last one uh six colon +3 what's the element at index six the + + align:start position:0% +3 what's the element at index six the + + + align:start position:0% +3 what's the element at index six the +empty work empty Colon work okay perfect + + align:start position:0% +empty work empty Colon work okay perfect + + + align:start position:0% +empty work empty Colon work okay perfect +thanks for trying it out the empty colon + + align:start position:0% +thanks for trying it out the empty colon + + + align:start position:0% +thanks for trying it out the empty colon +works yeah if you wanted to grab the a + + align:start position:0% +works yeah if you wanted to grab the a + + + align:start position:0% +works yeah if you wanted to grab the a +all right so S6 colon 3 what's the + + align:start position:0% +all right so S6 colon 3 what's the + + + align:start position:0% +all right so S6 colon 3 what's the +element at index six F the F okay great + + align:start position:0% +element at index six F the F okay great + + + align:start position:0% +element at index six F the F okay great +and we're working our way to the right + + align:start position:0% +and we're working our way to the right + + + align:start position:0% +and we're working our way to the right +or to the + + align:start position:0% +or to the + + + align:start position:0% +or to the +left to the right okay so we're going to + + align:start position:0% +left to the right okay so we're going to + + + align:start position:0% +left to the right okay so we're going to +start here but we need to go this way + + align:start position:0% +start here but we need to go this way + + + align:start position:0% +start here but we need to go this way +but what's the stop + + align:start position:0% +but what's the stop + + + align:start position:0% +but what's the stop +index yeah it's not there it's behind + + align:start position:0% +index yeah it's not there it's behind + + + align:start position:0% +index yeah it's not there it's behind +us so this last one is actually an empty + + align:start position:0% +us so this last one is actually an empty + + + align:start position:0% +us so this last one is actually an empty +string and I'll even we can even we can + + align:start position:0% +string and I'll even we can even we can + + + align:start position:0% +string and I'll even we can even we can +try it with something else too um so if + + align:start position:0% +try it with something else too um so if + + + align:start position:0% +try it with something else too um so if +we have this ABC right if I'm indexing + + align:start position:0% +we have this ABC right if I'm indexing + + + align:start position:0% +we have this ABC right if I'm indexing +starting from Two and I'm going backward + + align:start position:0% +starting from Two and I'm going backward + + + align:start position:0% +starting from Two and I'm going backward +to zero then that gives me the empty + + align:start position:0% +to zero then that gives me the empty + + + align:start position:0% +to zero then that gives me the empty +string and the empty string is just + + align:start position:0% +string and the empty string is just + + + align:start position:0% +string and the empty string is just +quote quote with nothing + + align:start position:0% +quote quote with nothing + + + align:start position:0% +quote quote with nothing +inside so that means we didn't take any + + align:start position:0% +inside so that means we didn't take any + + + align:start position:0% +inside so that means we didn't take any +characters in that particular + + align:start position:0% + + + + align:start position:0% + +case is that right it's invalid it's + + align:start position:0% +case is that right it's invalid it's + + + align:start position:0% +case is that right it's invalid it's +valid we just there are no characters in + + align:start position:0% +valid we just there are no characters in + + + align:start position:0% +valid we just there are no characters in +between the F and behind the F + + align:start position:0% + + + + align:start position:0% + +yeah okay so I'll mention the strings + + align:start position:0% +yeah okay so I'll mention the strings + + + align:start position:0% +yeah okay so I'll mention the strings +are actually immutable objects and + + align:start position:0% +are actually immutable objects and + + + align:start position:0% +are actually immutable objects and +really a lot of the objects we've seen + + align:start position:0% +really a lot of the objects we've seen + + + align:start position:0% +really a lot of the objects we've seen +so far are immutable that means they + + align:start position:0% +so far are immutable that means they + + + align:start position:0% +so far are immutable that means they +can't be modified once they're created + + align:start position:0% +can't be modified once they're created + + + align:start position:0% +can't be modified once they're created +we've kind of seen this already right + + align:start position:0% +we've kind of seen this already right + + + align:start position:0% +we've kind of seen this already right +when I draw the memory diagrams when I + + align:start position:0% +when I draw the memory diagrams when I + + + align:start position:0% +when I draw the memory diagrams when I +create a new object which is you know + + align:start position:0% +create a new object which is you know + + + align:start position:0% +create a new object which is you know +for example what's the string version of + + align:start position:0% +for example what's the string version of + + + align:start position:0% +for example what's the string version of +this integer or you know when I cast a + + align:start position:0% +this integer or you know when I cast a + + + align:start position:0% +this integer or you know when I cast a +float to an in things like that I'm not + + align:start position:0% +float to an in things like that I'm not + + + align:start position:0% +float to an in things like that I'm not +changing those original objects I've + + align:start position:0% +changing those original objects I've + + + align:start position:0% +changing those original objects I've +created I'm just making a new little + + align:start position:0% +created I'm just making a new little + + + align:start position:0% +created I'm just making a new little +green box in my memory and reassigning + + align:start position:0% +green box in my memory and reassigning + + + align:start position:0% +green box in my memory and reassigning +the name and we're going to see later on + + align:start position:0% +the name and we're going to see later on + + + align:start position:0% +the name and we're going to see later on +in this course mutable objects which + + align:start position:0% +in this course mutable objects which + + + align:start position:0% +in this course mutable objects which +means that once you create them in + + align:start position:0% +means that once you create them in + + + align:start position:0% +means that once you create them in +memory you can modify them but for now + + align:start position:0% +memory you can modify them but for now + + + align:start position:0% +memory you can modify them but for now +anytime you make a change to such an + + align:start position:0% +anytime you make a change to such an + + + align:start position:0% +anytime you make a change to such an +object well you can't change the object + + align:start position:0% +object well you can't change the object + + + align:start position:0% +object well you can't change the object +right if you want to get a different + + align:start position:0% +right if you want to get a different + + + align:start position:0% +right if you want to get a different +version of the object python will create + + align:start position:0% +version of the object python will create + + + align:start position:0% +version of the object python will create +a new object in memory and you can + + align:start position:0% +a new object in memory and you can + + + align:start position:0% +a new object in memory and you can +reassign the variable to that new object + + align:start position:0% +reassign the variable to that new object + + + align:start position:0% +reassign the variable to that new object +so in this example if I want to grab uh + + align:start position:0% +so in this example if I want to grab uh + + + align:start position:0% +so in this example if I want to grab uh +if I have the uh the string C in memory + + align:start position:0% +if I have the uh the string C in memory + + + align:start position:0% +if I have the uh the string C in memory +like this and it's bound to variable s + + align:start position:0% +like this and it's bound to variable s + + + align:start position:0% +like this and it's bound to variable s +and I want to change the first letter to + + align:start position:0% +and I want to change the first letter to + + + align:start position:0% +and I want to change the first letter to +a b I'm not allowed to python won't let + + align:start position:0% +a b I'm not allowed to python won't let + + + align:start position:0% +a b I'm not allowed to python won't let +me do something like I want to change + + align:start position:0% +me do something like I want to change + + + align:start position:0% +me do something like I want to change +the + + align:start position:0% +the + + + align:start position:0% +the +uh the letter at index zero to B that's + + align:start position:0% +uh the letter at index zero to B that's + + + align:start position:0% +uh the letter at index zero to B that's +not + + align:start position:0% +not + + + align:start position:0% +not +allowed you can get new versions of that + + align:start position:0% +allowed you can get new versions of that + + + align:start position:0% +allowed you can get new versions of that +particular string so you can do some you + + align:start position:0% +particular string so you can do some you + + + align:start position:0% +particular string so you can do some you +know random uh expression to create the + + align:start position:0% +know random uh expression to create the + + + align:start position:0% +know random uh expression to create the +bar that you might want but then the C + + align:start position:0% +bar that you might want but then the C + + + align:start position:0% +bar that you might want but then the C +remains in memory right so the C will + + align:start position:0% +remains in memory right so the C will + + + align:start position:0% +remains in memory right so the C will +still be there we're just losing The + + align:start position:0% +still be there we're just losing The + + + align:start position:0% +still be there we're just losing The +Binding from + + align:start position:0% + + + + align:start position:0% + +it so uh any questions so far + + align:start position:0% +it so uh any questions so far + + + align:start position:0% +it so uh any questions so far +on these + + align:start position:0% +on these + + + align:start position:0% +on these +strings mostly they're a new data type + + align:start position:0% +strings mostly they're a new data type + + + align:start position:0% +strings mostly they're a new data type +right you haven't worked with them like + + align:start position:0% +right you haven't worked with them like + + + align:start position:0% +right you haven't worked with them like +you have with numbers so it's a little + + align:start position:0% +you have with numbers so it's a little + + + align:start position:0% +you have with numbers so it's a little +bit different again you know someone had + + align:start position:0% +bit different again you know someone had + + + align:start position:0% +bit different again you know someone had +a question how do you get the a right + + align:start position:0% +a question how do you get the a right + + + align:start position:0% +a question how do you get the a right +backward try it out in the console um + + align:start position:0% +backward try it out in the console um + + + align:start position:0% +backward try it out in the console um +I'm happy to answer questions help you + + align:start position:0% +I'm happy to answer questions help you + + + align:start position:0% +I'm happy to answer questions help you +try it try it along with you um but + + align:start position:0% +try it try it along with you um but + + + align:start position:0% +try it try it along with you um but +that's what the console is there for + + align:start position:0% +that's what the console is there for + + + align:start position:0% +that's what the console is there for +right the shell here that's what it's + + align:start position:0% +right the shell here that's what it's + + + align:start position:0% +right the shell here that's what it's +there for it's just to try quick little + + align:start position:0% +there for it's just to try quick little + + + align:start position:0% +there for it's just to try quick little +things if you ever have a question you + + align:start position:0% +things if you ever have a question you + + + align:start position:0% +things if you ever have a question you +know what if this or this and you get to + + align:start position:0% +know what if this or this and you get to + + + align:start position:0% +know what if this or this and you get to +try it out + + align:start position:0% +try it out + + + align:start position:0% +try it out +now let's move on to some input output + + align:start position:0% +now let's move on to some input output + + + align:start position:0% +now let's move on to some input output +right so far the programs that we can + + align:start position:0% +right so far the programs that we can + + + align:start position:0% +right so far the programs that we can +write are pretty stagnant right there + + align:start position:0% +write are pretty stagnant right there + + + align:start position:0% +write are pretty stagnant right there +isn't much interesting uh things that we + + align:start position:0% +isn't much interesting uh things that we + + + align:start position:0% +isn't much interesting uh things that we +can do with them there's no interaction + + align:start position:0% +can do with them there's no interaction + + + align:start position:0% +can do with them there's no interaction +with the + + align:start position:0% +with the + + + align:start position:0% +with the +user so so far when we've tried to + + align:start position:0% +user so so far when we've tried to + + + align:start position:0% +user so so far when we've tried to +Output things well we you might think we + + align:start position:0% +Output things well we you might think we + + + align:start position:0% +Output things well we you might think we +have been outputting things right so + + align:start position:0% +have been outputting things right so + + + align:start position:0% +have been outputting things right so +when we write in our console something + + align:start position:0% +when we write in our console something + + + align:start position:0% +when we write in our console something +like 3+ two python does show something + + align:start position:0% +like 3+ two python does show something + + + align:start position:0% +like 3+ two python does show something +in the Shell right this is maybe how we + + align:start position:0% +in the Shell right this is maybe how we + + + align:start position:0% +in the Shell right this is maybe how we +interact with the user user but this is + + align:start position:0% +interact with the user user but this is + + + align:start position:0% +interact with the user user but this is +not actual true output this is I I call + + align:start position:0% +not actual true output this is I I call + + + align:start position:0% +not actual true output this is I I call +this kind of like peeking into the value + + align:start position:0% +this kind of like peeking into the value + + + align:start position:0% +this kind of like peeking into the value +of the expression but if you were to + + align:start position:0% +of the expression but if you were to + + + align:start position:0% +of the expression but if you were to +write some uh some expression like this + + align:start position:0% +write some uh some expression like this + + + align:start position:0% +write some uh some expression like this +in a file editor python wouldn't + + align:start position:0% +in a file editor python wouldn't + + + align:start position:0% +in a file editor python wouldn't +actually print it out and so here's all + + align:start position:0% +actually print it out and so here's all + + + align:start position:0% +actually print it out and so here's all +the things that we've already tried + + align:start position:0% +the things that we've already tried + + + align:start position:0% +the things that we've already tried +today right we've created all these + + align:start position:0% +today right we've created all these + + + align:start position:0% +today right we've created all these +strings we've got the length of s right + + align:start position:0% +strings we've got the length of s right + + + align:start position:0% +strings we've got the length of s right +we indexed anytime we typed these + + align:start position:0% +we indexed anytime we typed these + + + align:start position:0% +we indexed anytime we typed these +expressions in the Shell python + + align:start position:0% +expressions in the Shell python + + + align:start position:0% +expressions in the Shell python +automatically gave us our value right + + align:start position:0% +automatically gave us our value right + + + align:start position:0% +automatically gave us our value right +but if I were to type those exact + + align:start position:0% +but if I were to type those exact + + + align:start position:0% +but if I were to type those exact +expressions in a file editor on the left + + align:start position:0% +expressions in a file editor on the left + + + align:start position:0% +expressions in a file editor on the left +here Python's not actually going to + + align:start position:0% +here Python's not actually going to + + + align:start position:0% +here Python's not actually going to +print these out so this is the file + + align:start position:0% +print these out so this is the file + + + align:start position:0% +print these out so this is the file +editor from now on we're just going to + + align:start position:0% +editor from now on we're just going to + + + align:start position:0% +editor from now on we're just going to +work with files I'm going to run it by + + align:start position:0% +work with files I'm going to run it by + + + align:start position:0% +work with files I'm going to run it by +hitting this little green run button or + + align:start position:0% +hitting this little green run button or + + + align:start position:0% +hitting this little green run button or +hitting + + align:start position:0% +hitting + + + align:start position:0% +hitting +F5 something happened in the Shell my + + align:start position:0% +F5 something happened in the Shell my + + + align:start position:0% +F5 something happened in the Shell my +program + + align:start position:0% +program + + + align:start position:0% +program +ran right it says here it ran this file + + align:start position:0% +ran right it says here it ran this file + + + align:start position:0% +ran right it says here it ran this file +but there's no output right where was + + align:start position:0% +but there's no output right where was + + + align:start position:0% +but there's no output right where was +the length of s where were all these + + align:start position:0% +the length of s where were all these + + + align:start position:0% +the length of s where were all these +indices we've done before and that's + + align:start position:0% +indices we've done before and that's + + + align:start position:0% +indices we've done before and that's +because these aren't actual outputs + + align:start position:0% +because these aren't actual outputs + + + align:start position:0% +because these aren't actual outputs +right when we typed them into the shell + + align:start position:0% +right when we typed them into the shell + + + align:start position:0% +right when we typed them into the shell +that was just us doing quick little + + align:start position:0% +that was just us doing quick little + + + align:start position:0% +that was just us doing quick little +expressions in the Shell giving us quick + + align:start position:0% +expressions in the Shell giving us quick + + + align:start position:0% +expressions in the Shell giving us quick +you know I that's why I call it peeking + + align:start position:0% +you know I that's why I call it peeking + + + align:start position:0% +you know I that's why I call it peeking +into the value because it's not true + + align:start position:0% +into the value because it's not true + + + align:start position:0% +into the value because it's not true +output if you want the user to see + + align:start position:0% +output if you want the user to see + + + align:start position:0% +output if you want the user to see +output and the shell is how we're going + + align:start position:0% +output and the shell is how we're going + + + align:start position:0% +output and the shell is how we're going +to show the user output from running a + + align:start position:0% +to show the user output from running a + + + align:start position:0% +to show the user output from running a +file we have to explicitly tell python + + align:start position:0% +file we have to explicitly tell python + + + align:start position:0% +file we have to explicitly tell python +hey I want you to show the output from + + align:start position:0% +hey I want you to show the output from + + + align:start position:0% +hey I want you to show the output from +this expression or I want you to show + + align:start position:0% +this expression or I want you to show + + + align:start position:0% +this expression or I want you to show +the out output from this command okay + + align:start position:0% +the out output from this command okay + + + align:start position:0% +the out output from this command okay +and we do this using the print command + + align:start position:0% +and we do this using the print command + + + align:start position:0% +and we do this using the print command +so if we take our expression that we + + align:start position:0% +so if we take our expression that we + + + align:start position:0% +so if we take our expression that we +want to show the output from and wrap it + + align:start position:0% +want to show the output from and wrap it + + + align:start position:0% +want to show the output from and wrap it +in a print command python will then show + + align:start position:0% +in a print command python will then show + + + align:start position:0% +in a print command python will then show +that output and only that output right + + align:start position:0% +that output and only that output right + + + align:start position:0% +that output and only that output right +can you imagine if we wrote a file that + + align:start position:0% +can you imagine if we wrote a file that + + + align:start position:0% +can you imagine if we wrote a file that +did all these operations and all these + + align:start position:0% +did all these operations and all these + + + align:start position:0% +did all these operations and all these +intermediary outputs were being shown + + align:start position:0% +intermediary outputs were being shown + + + align:start position:0% +intermediary outputs were being shown +that would lead to a really messy file + + align:start position:0% +that would lead to a really messy file + + + align:start position:0% +that would lead to a really messy file +or a messy program right and so that's + + align:start position:0% +or a messy program right and so that's + + + align:start position:0% +or a messy program right and so that's +why we have a command where you can + + align:start position:0% +why we have a command where you can + + + align:start position:0% +why we have a command where you can +explicitly tell python just the things + + align:start position:0% +explicitly tell python just the things + + + align:start position:0% +explicitly tell python just the things +you want to show to the user + + align:start position:0% +you want to show to the user + + + align:start position:0% +you want to show to the user +so here if you want to print the length + + align:start position:0% +so here if you want to print the length + + + align:start position:0% +so here if you want to print the length +of s we can wrap the length of s in a + + align:start position:0% +of s we can wrap the length of s in a + + + align:start position:0% +of s we can wrap the length of s in a +print statement and then run the file + + align:start position:0% +print statement and then run the file + + + align:start position:0% +print statement and then run the file +and now the only thing that gets shown + + align:start position:0% +and now the only thing that gets shown + + + align:start position:0% +and now the only thing that gets shown +to the user is the thing I explicitly + + align:start position:0% +to the user is the thing I explicitly + + + align:start position:0% +to the user is the thing I explicitly +printed out the + + align:start position:0% +printed out the + + + align:start position:0% +printed out the +three right and then down here if I want + + align:start position:0% +three right and then down here if I want + + + align:start position:0% +three right and then down here if I want +to print this other result this the + + align:start position:0% +to print this other result this the + + + align:start position:0% +to print this other result this the +result of this other expression I can + + align:start position:0% +result of this other expression I can + + + align:start position:0% +result of this other expression I can +wrap that around a print statement and + + align:start position:0% +wrap that around a print statement and + + + align:start position:0% +wrap that around a print statement and +python will then print that one as well + + align:start position:0% +python will then print that one as well + + + align:start position:0% +python will then print that one as well +but now I'm in charge of showing the + + align:start position:0% +but now I'm in charge of showing the + + + align:start position:0% +but now I'm in charge of showing the +user the things that I want to show show + + align:start position:0% +user the things that I want to show show + + + align:start position:0% +user the things that I want to show show +them + + align:start position:0% + + + + align:start position:0% + +right + + align:start position:0% +right + + + align:start position:0% +right +okay so whenever you have a print + + align:start position:0% +okay so whenever you have a print + + + align:start position:0% +okay so whenever you have a print +statement python will print that + + align:start position:0% +statement python will print that + + + align:start position:0% +statement python will print that +resulting expression and then enter a + + align:start position:0% +resulting expression and then enter a + + + align:start position:0% +resulting expression and then enter a +new line so as you saw here we had two + + align:start position:0% +new line so as you saw here we had two + + + align:start position:0% +new line so as you saw here we had two +print statements one around Len and one + + align:start position:0% +print statements one around Len and one + + + align:start position:0% +print statements one around Len and one +around s atg -3 and python put the + + align:start position:0% +around s atg -3 and python put the + + + align:start position:0% +around s atg -3 and python put the +result of these um uh Expressions each + + align:start position:0% +result of these um uh Expressions each + + + align:start position:0% +result of these um uh Expressions each +one on a different line sometimes you + + align:start position:0% +one on a different line sometimes you + + + align:start position:0% +one on a different line sometimes you +might want to have Expressions on the + + align:start position:0% +might want to have Expressions on the + + + align:start position:0% +might want to have Expressions on the +same line or uh the results of + + align:start position:0% +same line or uh the results of + + + align:start position:0% +same line or uh the results of +Expressions all on the the same line so + + align:start position:0% +Expressions all on the the same line so + + + align:start position:0% +Expressions all on the the same line so +we can do that we can put all of these + + align:start position:0% +we can do that we can put all of these + + + align:start position:0% +we can do that we can put all of these +different objects within the same print + + align:start position:0% +different objects within the same print + + + align:start position:0% +different objects within the same print +statement okay we separate them by a + + align:start position:0% +statement okay we separate them by a + + + align:start position:0% +statement okay we separate them by a +comma within the print statement that's + + align:start position:0% +comma within the print statement that's + + + align:start position:0% +comma within the print statement that's +down here python will print all of our + + align:start position:0% +down here python will print all of our + + + align:start position:0% +down here python will print all of our +objects no matter what types they are + + align:start position:0% +objects no matter what types they are + + + align:start position:0% +objects no matter what types they are +and it'll separate each object by a + + align:start position:0% +and it'll separate each object by a + + + align:start position:0% +and it'll separate each object by a +space so there's my object the there's + + align:start position:0% +space so there's my object the there's + + + align:start position:0% +space so there's my object the there's +my object the number three and there's + + align:start position:0% +my object the number three and there's + + + align:start position:0% +my object the number three and there's +my object the string Musketeers and it + + align:start position:0% +my object the string Musketeers and it + + + align:start position:0% +my object the string Musketeers and it +printed it all on one line with the + + align:start position:0% +printed it all on one line with the + + + align:start position:0% +printed it all on one line with the +space in between them and that's what + + align:start position:0% +space in between them and that's what + + + align:start position:0% +space in between them and that's what +this comma does it automatically inserts + + align:start position:0% +this comma does it automatically inserts + + + align:start position:0% +this comma does it automatically inserts +the + + align:start position:0% +the + + + align:start position:0% +the +space now let's say you don't want a + + align:start position:0% +space now let's say you don't want a + + + align:start position:0% +space now let's say you don't want a +space for whatever + + align:start position:0% +space for whatever + + + align:start position:0% +space for whatever +reason what if we try concatenating + + align:start position:0% +reason what if we try concatenating + + + align:start position:0% +reason what if we try concatenating +these objects together right remember we + + align:start position:0% +these objects together right remember we + + + align:start position:0% +these objects together right remember we +saw concatenation we said it doesn't + + align:start position:0% +saw concatenation we said it doesn't + + + align:start position:0% +saw concatenation we said it doesn't +automatically insert spaces it just kind + + align:start position:0% +automatically insert spaces it just kind + + + align:start position:0% +automatically insert spaces it just kind +of merges the strings together and we + + align:start position:0% +of merges the strings together and we + + + align:start position:0% +of merges the strings together and we +run it well I kind of already gave it + + align:start position:0% +run it well I kind of already gave it + + + align:start position:0% +run it well I kind of already gave it +away it's going to be an error but let's + + align:start position:0% +away it's going to be an error but let's + + + align:start position:0% +away it's going to be an error but let's +see the error it's a type error it says + + align:start position:0% +see the error it's a type error it says + + + align:start position:0% +see the error it's a type error it says +can only concatenate strings not + + align:start position:0% +can only concatenate strings not + + + align:start position:0% +can only concatenate strings not +integers to + + align:start position:0% +integers to + + + align:start position:0% +integers to +strings all right makes sense this is a + + align:start position:0% +strings all right makes sense this is a + + + align:start position:0% +strings all right makes sense this is a +string this is not a string so that's + + align:start position:0% +string this is not a string so that's + + + align:start position:0% +string this is not a string so that's +not okay and this is a + + align:start position:0% +not okay and this is a + + + align:start position:0% +not okay and this is a +string so instead of + + align:start position:0% +string so instead of + + + align:start position:0% +string so instead of +concatenating different objects together + + align:start position:0% +concatenating different objects together + + + align:start position:0% +concatenating different objects together +we now have to remember to cast every + + align:start position:0% +we now have to remember to cast every + + + align:start position:0% +we now have to remember to cast every +object that's not a string to a string + + align:start position:0% +object that's not a string to a string + + + align:start position:0% +object that's not a string to a string +so this line is exactly the same as the + + align:start position:0% +so this line is exactly the same as the + + + align:start position:0% +so this line is exactly the same as the +previous one except that b which was the + + align:start position:0% +previous one except that b which was the + + + align:start position:0% +previous one except that b which was the +number the integer three is now being + + align:start position:0% +number the integer three is now being + + + align:start position:0% +number the integer three is now being +cast to a string so I'm wrapping the B + + align:start position:0% +cast to a string so I'm wrapping the B + + + align:start position:0% +cast to a string so I'm wrapping the B +around + + align:start position:0% +around + + + align:start position:0% +around +the Str Str and that casts my integer to + + align:start position:0% +the Str Str and that casts my integer to + + + align:start position:0% +the Str Str and that casts my integer to +the string and now python is happy to + + align:start position:0% +the string and now python is happy to + + + align:start position:0% +the string and now python is happy to +concatenate these three strings for + + align:start position:0% + + + + align:start position:0% + +me okay that's basically what I said so + + align:start position:0% +me okay that's basically what I said so + + + align:start position:0% +me okay that's basically what I said so +that's output using the print statement + + align:start position:0% +that's output using the print statement + + + align:start position:0% +that's output using the print statement +now how about + + align:start position:0% +now how about + + + align:start position:0% +now how about +input we can get input from the user not + + align:start position:0% +input we can get input from the user not + + + align:start position:0% +input we can get input from the user not +surprisingly with a command called input + + align:start position:0% +surprisingly with a command called input + + + align:start position:0% +surprisingly with a command called input +the format of input is usually like this + + align:start position:0% +the format of input is usually like this + + + align:start position:0% +the format of input is usually like this +so we have the input command in the + + align:start position:0% +so we have the input command in the + + + align:start position:0% +so we have the input command in the +parentheses we give it a string and then + + align:start position:0% +parentheses we give it a string and then + + + align:start position:0% +parentheses we give it a string and then +we usually want to save the input to a + + align:start position:0% +we usually want to save the input to a + + + align:start position:0% +we usually want to save the input to a +variable so the next few slides are + + align:start position:0% +variable so the next few slides are + + + align:start position:0% +variable so the next few slides are +going to go through step by step what + + align:start position:0% +going to go through step by step what + + + align:start position:0% +going to go through step by step what +happens when I have these two lines of + + align:start position:0% +happens when I have these two lines of + + + align:start position:0% +happens when I have these two lines of +code text equals input type anything and + + align:start position:0% +code text equals input type anything and + + + align:start position:0% +code text equals input type anything and +then I'm going to print five times + + align:start position:0% +then I'm going to print five times + + + align:start position:0% +then I'm going to print five times +text so when python sees a line that + + align:start position:0% +text so when python sees a line that + + + align:start position:0% +text so when python sees a line that +says you know input and then some string + + align:start position:0% +says you know input and then some string + + + align:start position:0% +says you know input and then some string +python will automatically take the + + align:start position:0% +python will automatically take the + + + align:start position:0% +python will automatically take the +string within the input right so in this + + align:start position:0% +string within the input right so in this + + + align:start position:0% +string within the input right so in this +particular case here's my input command + + align:start position:0% +particular case here's my input command + + + align:start position:0% +particular case here's my input command +the string inside the input is type + + align:start position:0% +the string inside the input is type + + + align:start position:0% +the string inside the input is type +anything colon space on the shell python + + align:start position:0% +anything colon space on the shell python + + + align:start position:0% +anything colon space on the shell python +will put that string for you and then it + + align:start position:0% +will put that string for you and then it + + + align:start position:0% +will put that string for you and then it +will + + align:start position:0% +will + + + align:start position:0% +will +wait it waits for the user to type some + + align:start position:0% +wait it waits for the user to type some + + + align:start position:0% +wait it waits for the user to type some +stuff in and hit + + align:start position:0% +stuff in and hit + + + align:start position:0% +stuff in and hit +enter as soon as the user hits enter + + align:start position:0% +enter as soon as the user hits enter + + + align:start position:0% +enter as soon as the user hits enter +whatever the user typed in so let's say + + align:start position:0% +whatever the user typed in so let's say + + + align:start position:0% +whatever the user typed in so let's say +the user typed in howdy whatever the + + align:start position:0% +the user typed in howdy whatever the + + + align:start position:0% +the user typed in howdy whatever the +user types in will be saved as a + + align:start position:0% +user types in will be saved as a + + + align:start position:0% +user types in will be saved as a +string sort of + + align:start position:0% +string sort of + + + align:start position:0% +string sort of +replacing this input statement so you + + align:start position:0% +replacing this input statement so you + + + align:start position:0% +replacing this input statement so you +can think of the input kind of like an + + align:start position:0% +can think of the input kind of like an + + + align:start position:0% +can think of the input kind of like an +expression it's a weird one because it's + + align:start position:0% +expression it's a weird one because it's + + + align:start position:0% +expression it's a weird one because it's +waiting for the user to give us + + align:start position:0% +waiting for the user to give us + + + align:start position:0% +waiting for the user to give us +something right but in the end the input + + align:start position:0% +something right but in the end the input + + + align:start position:0% +something right but in the end the input +gets replaced by the string version of + + align:start position:0% +gets replaced by the string version of + + + align:start position:0% +gets replaced by the string version of +whatever the user typed in so the user + + align:start position:0% +whatever the user typed in so the user + + + align:start position:0% +whatever the user typed in so the user +can type in something you know numbers + + align:start position:0% +can type in something you know numbers + + + align:start position:0% +can type in something you know numbers +letters characters anything as as soon + + align:start position:0% +letters characters anything as as soon + + + align:start position:0% +letters characters anything as as soon +as the user hits enter whatever the user + + align:start position:0% +as the user hits enter whatever the user + + + align:start position:0% +as the user hits enter whatever the user +typed in will be saved as a string + + align:start position:0% +typed in will be saved as a string + + + align:start position:0% +typed in will be saved as a string +replacing this + + align:start position:0% +replacing this + + + align:start position:0% +replacing this +input so in memory the way this looks + + align:start position:0% +input so in memory the way this looks + + + align:start position:0% +input so in memory the way this looks +like is this is our you know memory + + align:start position:0% +like is this is our you know memory + + + align:start position:0% +like is this is our you know memory +Cloud here is this very here is this + + align:start position:0% +Cloud here is this very here is this + + + align:start position:0% +Cloud here is this very here is this +object that I've created which is the + + align:start position:0% +object that I've created which is the + + + align:start position:0% +object that I've created which is the +exact characters the user typed + + align:start position:0% +exact characters the user typed + + + align:start position:0% +exact characters the user typed +in okay well if the user typed in howdy + + align:start position:0% +in okay well if the user typed in howdy + + + align:start position:0% +in okay well if the user typed in howdy +then what does this line end up being + + align:start position:0% +then what does this line end up being + + + align:start position:0% +then what does this line end up being +text is equal to the string + + align:start position:0% +text is equal to the string + + + align:start position:0% +text is equal to the string +howdy and that basically is what we've + + align:start position:0% +howdy and that basically is what we've + + + align:start position:0% +howdy and that basically is what we've +seen on the previous two slides right + + align:start position:0% +seen on the previous two slides right + + + align:start position:0% +seen on the previous two slides right +when we've worked with strings we're + + align:start position:0% +when we've worked with strings we're + + + align:start position:0% +when we've worked with strings we're +going to assign uh this variable and + + align:start position:0% +going to assign uh this variable and + + + align:start position:0% +going to assign uh this variable and +bind it to this particular string of + + align:start position:0% + + + + align:start position:0% + +characters now the next line is easy + + align:start position:0% +characters now the next line is easy + + + align:start position:0% +characters now the next line is easy +right we're going to print whatever the + + align:start position:0% +right we're going to print whatever the + + + align:start position:0% +right we're going to print whatever the +result of repeating text is five + + align:start position:0% +result of repeating text is five + + + align:start position:0% +result of repeating text is five +times so the print will uh show on the + + align:start position:0% +times so the print will uh show on the + + + align:start position:0% +times so the print will uh show on the +shell howdy howdy howdy howdy howdy + + align:start position:0% +shell howdy howdy howdy howdy howdy + + + align:start position:0% +shell howdy howdy howdy howdy howdy +right five that whatever the user typed + + align:start position:0% +right five that whatever the user typed + + + align:start position:0% +right five that whatever the user typed +in five times + + align:start position:0% + + + + align:start position:0% + +okay let's look at another example in + + align:start position:0% +okay let's look at another example in + + + align:start position:0% +okay let's look at another example in +this particular one we're going to ask + + align:start position:0% +this particular one we're going to ask + + + align:start position:0% +this particular one we're going to ask +the user for a number and I want to + + align:start position:0% +the user for a number and I want to + + + align:start position:0% +the user for a number and I want to +print five times whatever the user types + + align:start position:0% +print five times whatever the user types + + + align:start position:0% +print five times whatever the user types +in so num one we again grab input so + + align:start position:0% +in so num one we again grab input so + + + align:start position:0% +in so num one we again grab input so +what we're asking the user to do is to + + align:start position:0% +what we're asking the user to do is to + + + align:start position:0% +what we're asking the user to do is to +uh type in a number right so when the + + align:start position:0% +uh type in a number right so when the + + + align:start position:0% +uh type in a number right so when the +python sees this it uh prints type a + + align:start position:0% +python sees this it uh prints type a + + + align:start position:0% +python sees this it uh prints type a +number and then waits for user input + + align:start position:0% +number and then waits for user input + + + align:start position:0% +number and then waits for user input +let's say the user types in the number + + align:start position:0% +let's say the user types in the number + + + align:start position:0% +let's say the user types in the number +three that gets saved as the string + + align:start position:0% +three that gets saved as the string + + + align:start position:0% +three that gets saved as the string +three again so no matter what the user + + align:start position:0% +three again so no matter what the user + + + align:start position:0% +three again so no matter what the user +types in it's being saved as a string + + align:start position:0% +types in it's being saved as a string + + + align:start position:0% +types in it's being saved as a string +even if it's a number it's being saved + + align:start position:0% +even if it's a number it's being saved + + + align:start position:0% +even if it's a number it's being saved +as the string that number right so to + + align:start position:0% +as the string that number right so to + + + align:start position:0% +as the string that number right so to +python it's a character to us it's a + + align:start position:0% +python it's a character to us it's a + + + align:start position:0% +python it's a character to us it's a +number but to python it's still a + + align:start position:0% +number but to python it's still a + + + align:start position:0% +number but to python it's still a +character so num one in memory basically + + align:start position:0% +character so num one in memory basically + + + align:start position:0% +character so num one in memory basically +becomes the string three just one single + + align:start position:0% +becomes the string three just one single + + + align:start position:0% +becomes the string three just one single +character + + align:start position:0% +character + + + align:start position:0% +character +three when I print five times num one + + align:start position:0% +three when I print five times num one + + + align:start position:0% +three when I print five times num one +what is that going to look like you guys + + align:start position:0% +what is that going to look like you guys + + + align:start position:0% +what is that going to look like you guys +tell me + + align:start position:0% +tell me + + + align:start position:0% +tell me +exactly right 3 3 3 3 three right + + align:start position:0% +exactly right 3 3 3 3 three right + + + align:start position:0% +exactly right 3 3 3 3 three right +because we're not we're working with a + + align:start position:0% +because we're not we're working with a + + + align:start position:0% +because we're not we're working with a +string here not an + + align:start position:0% +string here not an + + + align:start position:0% +string here not an +integer if we want to work with an + + align:start position:0% +integer if we want to work with an + + + align:start position:0% +integer if we want to work with an +integer we have to wrap our input + + align:start position:0% +integer we have to wrap our input + + + align:start position:0% +integer we have to wrap our input +statement with a cast statement right so + + align:start position:0% +statement with a cast statement right so + + + align:start position:0% +statement with a cast statement right so +again this is what python does we can + + align:start position:0% +again this is what python does we can + + + align:start position:0% +again this is what python does we can +combine Expressions together in this + + align:start position:0% +combine Expressions together in this + + + align:start position:0% +combine Expressions together in this +particular case we're going to combine + + align:start position:0% +particular case we're going to combine + + + align:start position:0% +particular case we're going to combine +the uh casting the input with the input + + align:start position:0% +the uh casting the input with the input + + + align:start position:0% +the uh casting the input with the input +statement so now the user can type in + + align:start position:0% +statement so now the user can type in + + + align:start position:0% +statement so now the user can type in +for me three again the input itself is + + align:start position:0% +for me three again the input itself is + + + align:start position:0% +for me three again the input itself is +going to be the string three but that + + align:start position:0% +going to be the string three but that + + + align:start position:0% +going to be the string three but that +line becomes num two equals int + + align:start position:0% +line becomes num two equals int + + + align:start position:0% +line becomes num two equals int +parentheses string three right and that + + align:start position:0% +parentheses string three right and that + + + align:start position:0% +parentheses string three right and that +we've I did it on the shell a little + + align:start position:0% +we've I did it on the shell a little + + + align:start position:0% +we've I did it on the shell a little +earlier today right we when we cast a + + align:start position:0% +earlier today right we when we cast a + + + align:start position:0% +earlier today right we when we cast a +number a string to an INT it becomes the + + align:start position:0% +number a string to an INT it becomes the + + + align:start position:0% +number a string to an INT it becomes the +number that + + align:start position:0% + + + + align:start position:0% + +int so num two is then going to be + + align:start position:0% +int so num two is then going to be + + + align:start position:0% +int so num two is then going to be +three in memory num two is not the + + align:start position:0% +three in memory num two is not the + + + align:start position:0% +three in memory num two is not the +string anymore because we've cast it to + + align:start position:0% +string anymore because we've cast it to + + + align:start position:0% +string anymore because we've cast it to +three so when we print 5 * 3 we're doing + + align:start position:0% +three so when we print 5 * 3 we're doing + + + align:start position:0% +three so when we print 5 * 3 we're doing +the mathematical operation 5 * 3 right + + align:start position:0% + + + + align:start position:0% + +15 okay let's have you code so I'm going + + align:start position:0% +15 okay let's have you code so I'm going + + + align:start position:0% +15 okay let's have you code so I'm going +to give you a couple + + align:start position:0% +to give you a couple + + + align:start position:0% +to give you a couple +minutes I'm going to have you write a + + align:start position:0% +minutes I'm going to have you write a + + + align:start position:0% +minutes I'm going to have you write a +program that is interactive so it's + + align:start position:0% +program that is interactive so it's + + + align:start position:0% +program that is interactive so it's +going to ask the user for something and + + align:start position:0% +going to ask the user for something and + + + align:start position:0% +going to ask the user for something and +it's going to print the something uh + + align:start position:0% +it's going to print the something uh + + + align:start position:0% +it's going to print the something uh +back to the user so we're going to ask + + align:start position:0% +back to the user so we're going to ask + + + align:start position:0% +back to the user so we're going to ask +the user for a verb and then I want you + + align:start position:0% +the user for a verb and then I want you + + + align:start position:0% +the user for a verb and then I want you +to print two things for me the first is + + align:start position:0% +to print two things for me the first is + + + align:start position:0% +to print two things for me the first is +whatever the verb that user typed in + + align:start position:0% +whatever the verb that user typed in + + + align:start position:0% +whatever the verb that user typed in +you're going to write I can whatever + + align:start position:0% +you're going to write I can whatever + + + align:start position:0% +you're going to write I can whatever +better than you on one line and then on + + align:start position:0% +better than you on one line and then on + + + align:start position:0% +better than you on one line and then on +the next line so with another print + + align:start position:0% +the next line so with another print + + + align:start position:0% +the next line so with another print +statement I want you to print that verb + + align:start position:0% +statement I want you to print that verb + + + align:start position:0% +statement I want you to print that verb +five times so if the user types in run + + align:start position:0% +five times so if the user types in run + + + align:start position:0% +five times so if the user types in run +you're going to write I can run better + + align:start position:0% +you're going to write I can run better + + + align:start position:0% +you're going to write I can run better +than you and then on the next line run + + align:start position:0% +than you and then on the next line run + + + align:start position:0% +than you and then on the next line run +run run run run so the way these try it + + align:start position:0% +run run run run so the way these try it + + + align:start position:0% +run run run run so the way these try it +you try it work is I actually have some + + align:start position:0% +you try it work is I actually have some + + + align:start position:0% +you try it work is I actually have some +space here I've already pre-written the + + align:start position:0% +space here I've already pre-written the + + + align:start position:0% +space here I've already pre-written the +instructions for you and all you have to + + align:start position:0% +instructions for you and all you have to + + + align:start position:0% +instructions for you and all you have to +do is fill in the code okay so I'll give + + align:start position:0% +do is fill in the code okay so I'll give + + + align:start position:0% +do is fill in the code okay so I'll give +you a couple minutes and then we'll + + align:start position:0% +you a couple minutes and then we'll + + + align:start position:0% +you a couple minutes and then we'll +write it together with suggestions from + + align:start position:0% +write it together with suggestions from + + + align:start position:0% +write it together with suggestions from +you and uh we'll see how how far we can + + align:start position:0% +you and uh we'll see how how far we can + + + align:start position:0% +you and uh we'll see how how far we can +get and we'll + + align:start position:0% +get and we'll + + + align:start position:0% +get and we'll +definitely we'll definitely finish it + + align:start position:0% +definitely we'll definitely finish it + + + align:start position:0% +definitely we'll definitely finish it +together so you don't have to finish it + + align:start position:0% +together so you don't have to finish it + + + align:start position:0% +together so you don't have to finish it +on your + + align:start position:0% + + + + align:start position:0% + +own yeah suppos + + align:start position:0% + + + + align:start position:0% + +to um you should have this file it's + + align:start position:0% +to um you should have this file it's + + + align:start position:0% +to um you should have this file it's +part of the zip file you downloaded for + + align:start position:0% +part of the zip file you downloaded for + + + align:start position:0% +part of the zip file you downloaded for +today + + align:start position:0% +today + + + align:start position:0% +today +uh yeah + + align:start position:0% + + + + align:start position:0% + +all right does anyone have a start for + + align:start position:0% +all right does anyone have a start for + + + align:start position:0% +all right does anyone have a start for +me so how can I ask the user for + + align:start position:0% +me so how can I ask the user for + + + align:start position:0% +me so how can I ask the user for +input + + align:start position:0% + + + + align:start position:0% + +yeah yep that works for me and I'm + + align:start position:0% +yeah yep that works for me and I'm + + + align:start position:0% +yeah yep that works for me and I'm +adding a little extra space here between + + align:start position:0% +adding a little extra space here between + + + align:start position:0% +adding a little extra space here between +the colon or whatever prompt you have + + align:start position:0% +the colon or whatever prompt you have + + + align:start position:0% +the colon or whatever prompt you have +just so that when the user types it in + + align:start position:0% +just so that when the user types it in + + + align:start position:0% +just so that when the user types it in +isn't it isn't right beside the colon or + + align:start position:0% +isn't it isn't right beside the colon or + + + align:start position:0% +isn't it isn't right beside the colon or +the end of your uh uh the end of this + + align:start position:0% + + + + align:start position:0% + +string so as soon as we do this the user + + align:start position:0% +string so as soon as we do this the user + + + align:start position:0% +string so as soon as we do this the user +will uh the program will wait and the + + align:start position:0% +will uh the program will wait and the + + + align:start position:0% +will uh the program will wait and the +user will get to type something in + + align:start position:0% +user will get to type something in + + + align:start position:0% +user will get to type something in +what's the next + + align:start position:0% +what's the next + + + align:start position:0% +what's the next +step what's the first how can you how + + align:start position:0% +step what's the first how can you how + + + align:start position:0% +step what's the first how can you how +can you use this + + align:start position:0% +can you use this + + + align:start position:0% +can you use this +um this input to uh print yep let's + + align:start position:0% +um this input to uh print yep let's + + + align:start position:0% +um this input to uh print yep let's +print something + + align:start position:0% + + + + align:start position:0% + +I can in quotes yep I can would you + + align:start position:0% +I can in quotes yep I can would you + + + align:start position:0% +I can in quotes yep I can would you +outside of the quotes put the + + align:start position:0% +outside of the quotes put the + + + align:start position:0% +outside of the quotes put the +question yep we can put put question yep + + align:start position:0% +question yep we can put put question yep + + + align:start position:0% +question yep we can put put question yep +exactly I can question comma because + + align:start position:0% +exactly I can question comma because + + + align:start position:0% +exactly I can question comma because +it's another object and I'm happy to put + + align:start position:0% +it's another object and I'm happy to put + + + align:start position:0% +it's another object and I'm happy to put +a space in between it I can question add + + align:start position:0% +a space in between it I can question add + + + align:start position:0% +a space in between it I can question add +another string better than you oops + + align:start position:0% +another string better than you oops + + + align:start position:0% +another string better than you oops +okay + + align:start position:0% + + + + align:start position:0% + +there and we don't need to write the + + align:start position:0% +there and we don't need to write the + + + align:start position:0% +there and we don't need to write the +full program right away we can just test + + align:start position:0% +full program right away we can just test + + + align:start position:0% +full program right away we can just test +this little bit out um so choose a verb + + align:start position:0% +this little bit out um so choose a verb + + + align:start position:0% +this little bit out um so choose a verb +run the one I gave you is fine that + + align:start position:0% +run the one I gave you is fine that + + + align:start position:0% +run the one I gave you is fine that +looks good so far all right so then then + + align:start position:0% +looks good so far all right so then then + + + align:start position:0% +looks good so far all right so then then +we can work keep working on the second + + align:start position:0% +we can work keep working on the second + + + align:start position:0% +we can work keep working on the second +part how can I print that + + align:start position:0% +part how can I print that + + + align:start position:0% +part how can I print that +verb five + + align:start position:0% +verb five + + + align:start position:0% +verb five +times yeah print and then Question Time + + align:start position:0% +times yeah print and then Question Time + + + align:start position:0% +times yeah print and then Question Time +5 print Question Time 5 okay let's run + + align:start position:0% +5 print Question Time 5 okay let's run + + + align:start position:0% +5 print Question Time 5 okay let's run +it and see what + + align:start position:0% +it and see what + + + align:start position:0% +it and see what +happens + + align:start position:0% +happens + + + align:start position:0% +happens +run not quite I'm missing spaces but + + align:start position:0% +run not quite I'm missing spaces but + + + align:start position:0% +run not quite I'm missing spaces but +this is an aome start how can I add the + + align:start position:0% +this is an aome start how can I add the + + + align:start position:0% +this is an aome start how can I add the +spaces in + + align:start position:0% +spaces in + + + align:start position:0% +spaces in +there + + align:start position:0% +there + + + align:start position:0% +there +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +put like with a space in parentheses yep + + align:start position:0% +put like with a space in parentheses yep + + + align:start position:0% +put like with a space in parentheses yep +we can uh concatenate it with a space + + align:start position:0% +we can uh concatenate it with a space + + + align:start position:0% +we can uh concatenate it with a space +exactly times on all that times five + + align:start position:0% +exactly times on all that times five + + + align:start position:0% +exactly times on all that times five +yeah let's try + + align:start position:0% +yeah let's try + + + align:start position:0% +yeah let's try +that + + align:start position:0% +that + + + align:start position:0% +that +run yep that looks pretty + + align:start position:0% +run yep that looks pretty + + + align:start position:0% +run yep that looks pretty +good I do want to mention one thing + + align:start position:0% +good I do want to mention one thing + + + align:start position:0% +good I do want to mention one thing +there is one Improvement we can make to + + align:start position:0% +there is one Improvement we can make to + + + align:start position:0% +there is one Improvement we can make to +this program if we look at the output + + align:start position:0% +this program if we look at the output + + + align:start position:0% +this program if we look at the output +here the thing that we're actually run + + align:start position:0% +here the thing that we're actually run + + + align:start position:0% +here the thing that we're actually run +uh printing out is this verb space right + + align:start position:0% +uh printing out is this verb space right + + + align:start position:0% +uh printing out is this verb space right +there's one two three four and the last + + align:start position:0% +there's one two three four and the last + + + align:start position:0% +there's one two three four and the last +one actually prints it with a space at + + align:start position:0% +one actually prints it with a space at + + + align:start position:0% +one actually prints it with a space at +the end so a challenge for you and the + + align:start position:0% +the end so a challenge for you and the + + + align:start position:0% +the end so a challenge for you and the +answer is a little bit lower I provide + + align:start position:0% +answer is a little bit lower I provide + + + align:start position:0% +answer is a little bit lower I provide +you guys with answers to these but a + + align:start position:0% +you guys with answers to these but a + + + align:start position:0% +you guys with answers to these but a +challenge for you is think about how you + + align:start position:0% +challenge for you is think about how you + + + align:start position:0% +challenge for you is think about how you +can change it change this last print + + align:start position:0% +can change it change this last print + + + align:start position:0% +can change it change this last print +statement so that this last run doesn't + + align:start position:0% +statement so that this last run doesn't + + + align:start position:0% +statement so that this last run doesn't +actually have that extra space just you + + align:start position:0% +actually have that extra space just you + + + align:start position:0% +actually have that extra space just you +know think about it + + align:start position:0% +know think about it + + + align:start position:0% +know think about it +um you don't have to do it right + + align:start position:0% + + + + align:start position:0% + +now okay so with what we know so far we + + align:start position:0% +now okay so with what we know so far we + + + align:start position:0% +now okay so with what we know so far we +can actually apply some of these ideas + + align:start position:0% +can actually apply some of these ideas + + + align:start position:0% +can actually apply some of these ideas +to a more numerical example um so + + align:start position:0% +to a more numerical example um so + + + align:start position:0% +to a more numerical example um so +Newton's method is a way to actually + + align:start position:0% +Newton's method is a way to actually + + + align:start position:0% +Newton's method is a way to actually +grab the uh the roots of a polinomial + + align:start position:0% +grab the uh the roots of a polinomial + + + align:start position:0% +grab the uh the roots of a polinomial +numerically using this idea called + + align:start position:0% +numerically using this idea called + + + align:start position:0% +numerically using this idea called +successive + + align:start position:0% +successive + + + align:start position:0% +successive +approximation we can't actually write + + align:start position:0% +approximation we can't actually write + + + align:start position:0% +approximation we can't actually write +the full algorithm with what we know so + + align:start position:0% +the full algorithm with what we know so + + + align:start position:0% +the full algorithm with what we know so +far but we can write a really important + + align:start position:0% +far but we can write a really important + + + align:start position:0% +far but we can write a really important +part of it the part is the the part that + + align:start position:0% +part of it the part is the the part that + + + align:start position:0% +part of it the part is the the part that +we can write is the one that gets a next + + align:start position:0% +we can write is the one that gets a next + + + align:start position:0% +we can write is the one that gets a next +guess based on an initial + + align:start position:0% +guess based on an initial + + + align:start position:0% +guess based on an initial +guess so you don't need to understand + + align:start position:0% +guess so you don't need to understand + + + align:start position:0% +guess so you don't need to understand +how the algorithm works but basically + + align:start position:0% +how the algorithm works but basically + + + align:start position:0% +how the algorithm works but basically +the next guess based on an original + + align:start position:0% +the next guess based on an original + + + align:start position:0% +the next guess based on an original +guess looks like this this is the + + align:start position:0% +guess looks like this this is the + + + align:start position:0% +guess looks like this this is the +formula so the next guess is the + + align:start position:0% +formula so the next guess is the + + + align:start position:0% +formula so the next guess is the +original guess minus and we evaluate the + + align:start position:0% +original guess minus and we evaluate the + + + align:start position:0% +original guess minus and we evaluate the +formula for whatever uh uh you know + + align:start position:0% +formula for whatever uh uh you know + + + align:start position:0% +formula for whatever uh uh you know +polinomial we want to find at the + + align:start position:0% +polinomial we want to find at the + + + align:start position:0% +polinomial we want to find at the +original guess divided by the derivative + + align:start position:0% +original guess divided by the derivative + + + align:start position:0% +original guess divided by the derivative +of that uh of that function at the same + + align:start position:0% +of that uh of that function at the same + + + align:start position:0% +of that uh of that function at the same +guess + + align:start position:0% + + + + align:start position:0% + +so here's just some code we've got + + align:start position:0% +so here's just some code we've got + + + align:start position:0% +so here's just some code we've got +uh asking the user for input what x do + + align:start position:0% +uh asking the user for input what x do + + + align:start position:0% +uh asking the user for input what x do +we want to find the cube root of then we + + align:start position:0% +we want to find the cube root of then we + + + align:start position:0% +we want to find the cube root of then we +ask the user for input what guest do you + + align:start position:0% +ask the user for input what guest do you + + + align:start position:0% +ask the user for input what guest do you +want to start with and then we can just + + align:start position:0% +want to start with and then we can just + + + align:start position:0% +want to start with and then we can just +print the current estimate cubed so we + + align:start position:0% +print the current estimate cubed so we + + + align:start position:0% +print the current estimate cubed so we +just guess + + align:start position:0% +just guess + + + align:start position:0% +just guess +cubed and then the next guess is just + + align:start position:0% +cubed and then the next guess is just + + + align:start position:0% +cubed and then the next guess is just +following the formula up here right the + + align:start position:0% +following the formula up here right the + + + align:start position:0% +following the formula up here right the +next guess is going to say it's my + + align:start position:0% +next guess is going to say it's my + + + align:start position:0% +next guess is going to say it's my +original guess so the G that I read in + + align:start position:0% +original guess so the G that I read in + + + align:start position:0% +original guess so the G that I read in +from the student or from the input minus + + align:start position:0% +from the student or from the input minus + + + align:start position:0% +from the student or from the input minus +and now I have a division the top of it + + align:start position:0% +and now I have a division the top of it + + + align:start position:0% +and now I have a division the top of it +is going to be F at + + align:start position:0% +is going to be F at + + + align:start position:0% +is going to be F at +G right and the computer is not + + align:start position:0% +G right and the computer is not + + + align:start position:0% +G right and the computer is not +evaluating F right we have to give we + + align:start position:0% +evaluating F right we have to give we + + + align:start position:0% +evaluating F right we have to give we +have to actually write down what the + + align:start position:0% +have to actually write down what the + + + align:start position:0% +have to actually write down what the +formula is uh the function is we want to + + align:start position:0% +formula is uh the function is we want to + + + align:start position:0% +formula is uh the function is we want to +evaluate at G so it's G Cub minus X + + align:start position:0% +evaluate at G so it's G Cub minus X + + + align:start position:0% +evaluate at G so it's G Cub minus X +that's our function up there divided by + + align:start position:0% +that's our function up there divided by + + + align:start position:0% +that's our function up there divided by +the derivative and again the program is + + align:start position:0% +the derivative and again the program is + + + align:start position:0% +the derivative and again the program is +not going to evaluate the derivative + + align:start position:0% +not going to evaluate the derivative + + + align:start position:0% +not going to evaluate the derivative +automatically we're going to tell it + + align:start position:0% +automatically we're going to tell it + + + align:start position:0% +automatically we're going to tell it +what the derivative is manually so you + + align:start position:0% +what the derivative is manually so you + + + align:start position:0% +what the derivative is manually so you +know the derivative G Cub - x is just 3 + + align:start position:0% +know the derivative G Cub - x is just 3 + + + align:start position:0% +know the derivative G Cub - x is just 3 +G ^2 so then we just kind of hardcode + + align:start position:0% +G ^2 so then we just kind of hardcode + + + align:start position:0% +G ^2 so then we just kind of hardcode +that in and the next guess to try is + + align:start position:0% +that in and the next guess to try is + + + align:start position:0% +that in and the next guess to try is +just going to be that particular + + align:start position:0% +just going to be that particular + + + align:start position:0% +just going to be that particular +Division and + + align:start position:0% + + + + align:start position:0% + +subtraction I'm sorry Sor there's no + + align:start position:0% +subtraction I'm sorry Sor there's no + + + align:start position:0% +subtraction I'm sorry Sor there's no +function there are there uh there are + + align:start position:0% +function there are there uh there are + + + align:start position:0% +function there are there uh there are +python packages that allow you to do + + align:start position:0% +python packages that allow you to do + + + align:start position:0% +python packages that allow you to do +that but for our purposes we we're just + + align:start position:0% +that but for our purposes we we're just + + + align:start position:0% +that but for our purposes we we're just +going to hard hard code it in this case + + align:start position:0% +going to hard hard code it in this case + + + align:start position:0% +going to hard hard code it in this case +but + + align:start position:0% +but + + + align:start position:0% +but +yeah so the way this + + align:start position:0% +yeah so the way this + + + align:start position:0% +yeah so the way this +looks um and code is as follows right + + align:start position:0% +looks um and code is as follows right + + + align:start position:0% +looks um and code is as follows right +that's exactly what we had in there and + + align:start position:0% +that's exactly what we had in there and + + + align:start position:0% +that's exactly what we had in there and +if we run this program all it does is + + align:start position:0% +if we run this program all it does is + + + align:start position:0% +if we run this program all it does is +let's say we want to find the cube root + + align:start position:0% +let's say we want to find the cube root + + + align:start position:0% +let's say we want to find the cube root +of say 27 let's start with I don't know + + align:start position:0% +of say 27 let's start with I don't know + + + align:start position:0% +of say 27 let's start with I don't know +five right it tells me that 5 cubed is + + align:start position:0% +five right it tells me that 5 cubed is + + + align:start position:0% +five right it tells me that 5 cubed is +125 way too big obviously so the next + + align:start position:0% +125 way too big obviously so the next + + + align:start position:0% +125 way too big obviously so the next +guess to try is + + align:start position:0% +guess to try is + + + align:start position:0% +guess to try is +3.69 right and that's all the program + + align:start position:0% +3.69 right and that's all the program + + + align:start position:0% +3.69 right and that's all the program +does it doesn't take this next guess and + + align:start position:0% +does it doesn't take this next guess and + + + align:start position:0% +does it doesn't take this next guess and +do another guess we haven't learned how + + align:start position:0% +do another guess we haven't learned how + + + align:start position:0% +do another guess we haven't learned how +to do such a thing yet but we will in + + align:start position:0% +to do such a thing yet but we will in + + + align:start position:0% +to do such a thing yet but we will in +the next couple lectures + + align:start position:0% + + + + align:start position:0% + +one other thing I want to mention is + + align:start position:0% +one other thing I want to mention is + + + align:start position:0% +one other thing I want to mention is +this thing called an F string um it's + + align:start position:0% +this thing called an F string um it's + + + align:start position:0% +this thing called an F string um it's +something that became available I think + + align:start position:0% +something that became available I think + + + align:start position:0% +something that became available I think +a couple years ago in Python with python + + align:start position:0% +a couple years ago in Python with python + + + align:start position:0% +a couple years ago in Python with python +3.6 it's a way more convenient way for + + align:start position:0% +3.6 it's a way more convenient way for + + + align:start position:0% +3.6 it's a way more convenient way for +us to print out mixtures of literal + + align:start position:0% +us to print out mixtures of literal + + + align:start position:0% +us to print out mixtures of literal +text and resulting Expressions so if you + + align:start position:0% +text and resulting Expressions so if you + + + align:start position:0% +text and resulting Expressions so if you +have a bunch of complicated Expressions + + align:start position:0% +have a bunch of complicated Expressions + + + align:start position:0% +have a bunch of complicated Expressions +you you want to print out an FST string + + align:start position:0% +you you want to print out an FST string + + + align:start position:0% +you you want to print out an FST string +is the way to do it these days um what + + align:start position:0% +is the way to do it these days um what + + + align:start position:0% +is the way to do it these days um what +we know is these first two lines this is + + align:start position:0% +we know is these first two lines this is + + + align:start position:0% +we know is these first two lines this is +what we've learned in the past couple + + align:start position:0% +what we've learned in the past couple + + + align:start position:0% +what we've learned in the past couple +slides so if you wanted to have you know + + align:start position:0% +slides so if you wanted to have you know + + + align:start position:0% +slides so if you wanted to have you know +these two values and print uh you know + + align:start position:0% +these two values and print uh you know + + + align:start position:0% +these two values and print uh you know +this big number is whatever fraction + + align:start position:0% +this big number is whatever fraction + + + align:start position:0% +this big number is whatever fraction +percent out of the original + + align:start position:0% +percent out of the original + + + align:start position:0% +percent out of the original +number if you actually run this in the + + align:start position:0% +number if you actually run this in the + + + align:start position:0% +number if you actually run this in the +in the python file you'll see that this + + align:start position:0% +in the python file you'll see that this + + + align:start position:0% +in the python file you'll see that this +comma here puts an extra space between + + align:start position:0% +comma here puts an extra space between + + + align:start position:0% +comma here puts an extra space between +my number and the percent right and that + + align:start position:0% +my number and the percent right and that + + + align:start position:0% +my number and the percent right and that +doesn't look very good when you have 3% + + align:start position:0% +doesn't look very good when you have 3% + + + align:start position:0% +doesn't look very good when you have 3% +You're Expecting the percent sign to be + + align:start position:0% +You're Expecting the percent sign to be + + + align:start position:0% +You're Expecting the percent sign to be +right by the three + + align:start position:0% +right by the three + + + align:start position:0% +right by the three +but this comma adds for me an extra + + align:start position:0% +but this comma adds for me an extra + + + align:start position:0% +but this comma adds for me an extra +space so it looks a little bit weird + + align:start position:0% +space so it looks a little bit weird + + + align:start position:0% +space so it looks a little bit weird +which means that our solution was to + + align:start position:0% +which means that our solution was to + + + align:start position:0% +which means that our solution was to +cast things to Strings so if we wanted + + align:start position:0% +cast things to Strings so if we wanted + + + align:start position:0% +cast things to Strings so if we wanted +to have that percent sign be right + + align:start position:0% +to have that percent sign be right + + + align:start position:0% +to have that percent sign be right +beside the number we'd + + align:start position:0% +beside the number we'd + + + align:start position:0% +beside the number we'd +concatenate this cast with a + + align:start position:0% +concatenate this cast with a + + + align:start position:0% +concatenate this cast with a +percent but F strings allow us to do + + align:start position:0% +percent but F strings allow us to do + + + align:start position:0% +percent but F strings allow us to do +this all in one so there's no + + align:start position:0% +this all in one so there's no + + + align:start position:0% +this all in one so there's no +concatenation to think about there's no + + align:start position:0% +concatenation to think about there's no + + + align:start position:0% +concatenation to think about there's no +casting to think about F strings + + align:start position:0% +casting to think about F strings + + + align:start position:0% +casting to think about F strings +basically are this F and then a long + + align:start position:0% +basically are this F and then a long + + + align:start position:0% +basically are this F and then a long +string and it's a mixture of expressions + + align:start position:0% +string and it's a mixture of expressions + + + align:start position:0% +string and it's a mixture of expressions +and things that I want to print + + align:start position:0% +and things that I want to print + + + align:start position:0% +and things that I want to print +literally to the screen so the thing + + align:start position:0% +literally to the screen so the thing + + + align:start position:0% +literally to the screen so the thing +that's not inside a curly bracket are + + align:start position:0% +that's not inside a curly bracket are + + + align:start position:0% +that's not inside a curly bracket are +all things I'm going to print literally + + align:start position:0% +all things I'm going to print literally + + + align:start position:0% +all things I'm going to print literally +to the screen so the space is space and + + align:start position:0% +to the screen so the space is space and + + + align:start position:0% +to the screen so the space is space and +then later on percent space of percent + + align:start position:0% +then later on percent space of percent + + + align:start position:0% +then later on percent space of percent +those are all things that will literally + + align:start position:0% +those are all things that will literally + + + align:start position:0% +those are all things that will literally +be printed to the screen anything that's + + align:start position:0% +be printed to the screen anything that's + + + align:start position:0% +be printed to the screen anything that's +within a curly bracket is considered an + + align:start position:0% +within a curly bracket is considered an + + + align:start position:0% +within a curly bracket is considered an +expression in Python and so before + + align:start position:0% +expression in Python and so before + + + align:start position:0% +expression in Python and so before +python prints out the thing to the + + align:start position:0% +python prints out the thing to the + + + align:start position:0% +python prints out the thing to the +screen it's actually going to evaluate + + align:start position:0% +screen it's actually going to evaluate + + + align:start position:0% +screen it's actually going to evaluate +whatever num times fraction is and it + + align:start position:0% +whatever num times fraction is and it + + + align:start position:0% +whatever num times fraction is and it +knows these are going to be variables + + align:start position:0% +knows these are going to be variables + + + align:start position:0% +knows these are going to be variables +and then later on fraction time 100 and + + align:start position:0% +and then later on fraction time 100 and + + + align:start position:0% +and then later on fraction time 100 and +then later on N these are all variables + + align:start position:0% +then later on N these are all variables + + + align:start position:0% +then later on N these are all variables +or Expressions that it will evaluate + + align:start position:0% +or Expressions that it will evaluate + + + align:start position:0% +or Expressions that it will evaluate +before actually putting them on the + + align:start position:0% +before actually putting them on the + + + align:start position:0% +before actually putting them on the +screen and now notice these these these + + align:start position:0% +screen and now notice these these these + + + align:start position:0% +screen and now notice these these these +Expressions we might have had to cast to + + align:start position:0% +Expressions we might have had to cast to + + + align:start position:0% +Expressions we might have had to cast to +Strings beforehand if we wanted to + + align:start position:0% +Strings beforehand if we wanted to + + + align:start position:0% +Strings beforehand if we wanted to +concatenate them but now we don't + + align:start position:0% +concatenate them but now we don't + + + align:start position:0% +concatenate them but now we don't +because they're in this special format + + align:start position:0% +because they're in this special format + + + align:start position:0% +because they're in this special format +with the curly brackets of the FST + + align:start position:0% +with the curly brackets of the FST + + + align:start position:0% +with the curly brackets of the FST +string so just something to practice uh + + align:start position:0% +string so just something to practice uh + + + align:start position:0% +string so just something to practice uh +I'll interchange change I'll I'll use + + align:start position:0% +I'll interchange change I'll I'll use + + + align:start position:0% +I'll interchange change I'll I'll use +sometimes this I'll use sometimes + + align:start position:0% +sometimes this I'll use sometimes + + + align:start position:0% +sometimes this I'll use sometimes +casting I'll use sometimes FST strings + + align:start position:0% +casting I'll use sometimes FST strings + + + align:start position:0% +casting I'll use sometimes FST strings +but um you know if you can use FST + + align:start position:0% +but um you know if you can use FST + + + align:start position:0% +but um you know if you can use FST +strings whenever you can that's really + + align:start position:0% +strings whenever you can that's really + + + align:start position:0% +strings whenever you can that's really +the way to go um uh in Python uh you + + align:start position:0% +the way to go um uh in Python uh you + + + align:start position:0% +the way to go um uh in Python uh you +know these + + align:start position:0% +know these + + + align:start position:0% +know these +days so the big idea actually even with + + align:start position:0% +days so the big idea actually even with + + + align:start position:0% +days so the big idea actually even with +FST strings is that you can place + + align:start position:0% +FST strings is that you can place + + + align:start position:0% +FST strings is that you can place +Expressions anywhere right we saw we + + align:start position:0% +Expressions anywhere right we saw we + + + align:start position:0% +Expressions anywhere right we saw we +placed expression I forget here where we + + align:start position:0% +placed expression I forget here where we + + + align:start position:0% +placed expression I forget here where we +where we indexed we placed an expression + + align:start position:0% +where we indexed we placed an expression + + + align:start position:0% +where we indexed we placed an expression +in the index right now we're placing + + align:start position:0% +in the index right now we're placing + + + align:start position:0% +in the index right now we're placing +expressions in uh inside print + + align:start position:0% +expressions in uh inside print + + + align:start position:0% +expressions in uh inside print +statements and now we're placing + + align:start position:0% +statements and now we're placing + + + align:start position:0% +statements and now we're placing +expressions inside F string so + + align:start position:0% +expressions inside F string so + + + align:start position:0% +expressions inside F string so +Expressions can be placed really + + align:start position:0% +Expressions can be placed really + + + align:start position:0% +Expressions can be placed really +anywhere which is pretty awesome very + + align:start position:0% +anywhere which is pretty awesome very + + + align:start position:0% +anywhere which is pretty awesome very +versatile python will just evaluate them + + align:start position:0% +versatile python will just evaluate them + + + align:start position:0% +versatile python will just evaluate them +and then just you know move on to the + + align:start position:0% +and then just you know move on to the + + + align:start position:0% +and then just you know move on to the +next + + align:start position:0% +next + + + align:start position:0% +next +lines okay so the last topic of sorry + + align:start position:0% +lines okay so the last topic of sorry + + + align:start position:0% +lines okay so the last topic of sorry +any other questions about the inputs and + + align:start position:0% +any other questions about the inputs and + + + align:start position:0% +any other questions about the inputs and +outputs or is that + + align:start position:0% +outputs or is that + + + align:start position:0% +outputs or is that +right okay so the last thing that uh + + align:start position:0% +right okay so the last thing that uh + + + align:start position:0% +right okay so the last thing that uh +we'll talk about today and we will maybe + + align:start position:0% +we'll talk about today and we will maybe + + + align:start position:0% +we'll talk about today and we will maybe +talk a little bit about it next time is + + align:start position:0% +talk a little bit about it next time is + + + align:start position:0% +talk a little bit about it next time is +conditions for branching + + align:start position:0% +conditions for branching + + + align:start position:0% +conditions for branching +so right now the kinds of programs we + + align:start position:0% +so right now the kinds of programs we + + + align:start position:0% +so right now the kinds of programs we +can write are basically very linear we + + align:start position:0% +can write are basically very linear we + + + align:start position:0% +can write are basically very linear we +have a bunch of lines of code and they + + align:start position:0% +have a bunch of lines of code and they + + + align:start position:0% +have a bunch of lines of code and they +get evaluated one by one there's no way + + align:start position:0% +get evaluated one by one there's no way + + + align:start position:0% +get evaluated one by one there's no way +to skip around there's no way to repeat + + align:start position:0% +to skip around there's no way to repeat + + + align:start position:0% +to skip around there's no way to repeat +things there's no decision points in the + + align:start position:0% +things there's no decision points in the + + + align:start position:0% +things there's no decision points in the +programs you know the values that you + + align:start position:0% +programs you know the values that you + + + align:start position:0% +programs you know the values that you +get are just the values that are in the + + align:start position:0% +get are just the values that are in the + + + align:start position:0% +get are just the values that are in the +program now we're going to look at ways + + align:start position:0% +program now we're going to look at ways + + + align:start position:0% +program now we're going to look at ways +that we can add decision points in our + + align:start position:0% +that we can add decision points in our + + + align:start position:0% +that we can add decision points in our +program so if some uh value if some + + align:start position:0% +program so if some uh value if some + + + align:start position:0% +program so if some uh value if some +variable value is less than some other + + align:start position:0% +variable value is less than some other + + + align:start position:0% +variable value is less than some other +variable value we want to valate some + + align:start position:0% +variable value we want to valate some + + + align:start position:0% +variable value we want to valate some +codee and otherwise we'll do some other + + align:start position:0% +codee and otherwise we'll do some other + + + align:start position:0% +codee and otherwise we'll do some other +code right so some code can now be + + align:start position:0% +code right so some code can now be + + + align:start position:0% +code right so some code can now be +skipped in programs with this new uh + + align:start position:0% +skipped in programs with this new uh + + + align:start position:0% +skipped in programs with this new uh +with this new + + align:start position:0% +with this new + + + align:start position:0% +with this new +idea before we go on to showing you + + align:start position:0% +idea before we go on to showing you + + + align:start position:0% +idea before we go on to showing you +exactly how to do that I'm going to talk + + align:start position:0% +exactly how to do that I'm going to talk + + + align:start position:0% +exactly how to do that I'm going to talk +about another notion of equal in + + align:start position:0% +about another notion of equal in + + + align:start position:0% +about another notion of equal in +programming and this might be more the + + align:start position:0% +programming and this might be more the + + + align:start position:0% +programming and this might be more the +notion of equal you might be used to in + + align:start position:0% +notion of equal you might be used to in + + + align:start position:0% +notion of equal you might be used to in +uh in math so the first notion of equal + + align:start position:0% +uh in math so the first notion of equal + + + align:start position:0% +uh in math so the first notion of equal +is the one we've already seen it's + + align:start position:0% +is the one we've already seen it's + + + align:start position:0% +is the one we've already seen it's +assignment it's done with one equal sign + + align:start position:0% +assignment it's done with one equal sign + + + align:start position:0% +assignment it's done with one equal sign +the value on the right hand side is + + align:start position:0% +the value on the right hand side is + + + align:start position:0% +the value on the right hand side is +bound to the variable on the left hand + + align:start position:0% +bound to the variable on the left hand + + + align:start position:0% +bound to the variable on the left hand +side right that we've + + align:start position:0% +side right that we've + + + align:start position:0% +side right that we've +known double equal in in Python is how + + align:start position:0% +known double equal in in Python is how + + + align:start position:0% +known double equal in in Python is how +we tell python that we'd like to know + + align:start position:0% +we tell python that we'd like to know + + + align:start position:0% +we tell python that we'd like to know +whether these two expressions are equal + + align:start position:0% +whether these two expressions are equal + + + align:start position:0% +whether these two expressions are equal +or equivalent sorry + + align:start position:0% +or equivalent sorry + + + align:start position:0% +or equivalent sorry +not + + align:start position:0% +not + + + align:start position:0% +not +so if we're going to be looking at + + align:start position:0% +so if we're going to be looking at + + + align:start position:0% +so if we're going to be looking at +equivalency how do we how so how do we + + align:start position:0% +equivalency how do we how so how do we + + + align:start position:0% +equivalency how do we how so how do we +express equivalency well if something is + + align:start position:0% +express equivalency well if something is + + + align:start position:0% +express equivalency well if something is +equal to something else we can say yes + + align:start position:0% +equal to something else we can say yes + + + align:start position:0% +equal to something else we can say yes +or no we can say true or false right + + align:start position:0% +or no we can say true or false right + + + align:start position:0% +or no we can say true or false right +true or false should ring a bell it's + + align:start position:0% +true or false should ring a bell it's + + + align:start position:0% +true or false should ring a bell it's +the Boolean data type that we saw last + + align:start position:0% +the Boolean data type that we saw last + + + align:start position:0% +the Boolean data type that we saw last +lecture and so now that we're going to + + align:start position:0% +lecture and so now that we're going to + + + align:start position:0% +lecture and so now that we're going to +show you equality or conditionals in + + align:start position:0% +show you equality or conditionals in + + + align:start position:0% +show you equality or conditionals in +programming we're going to start talking + + align:start position:0% +programming we're going to start talking + + + align:start position:0% +programming we're going to start talking +about booleans a little bit + + align:start position:0% +about booleans a little bit + + + align:start position:0% +about booleans a little bit +more so Expressions don't just have to + + align:start position:0% +more so Expressions don't just have to + + + align:start position:0% +more so Expressions don't just have to +be numerical expressions can actually + + align:start position:0% +be numerical expressions can actually + + + align:start position:0% +be numerical expressions can actually +give us Boolean results so for example + + align:start position:0% +give us Boolean results so for example + + + align:start position:0% +give us Boolean results so for example +an expression like + + align:start position:0% + + + + align:start position:0% + +2 less than + + align:start position:0% +2 less than + + + align:start position:0% +2 less than +three is okay in Python and this + + align:start position:0% +three is okay in Python and this + + + align:start position:0% +three is okay in Python and this +expression actually evaluates to a + + align:start position:0% +expression actually evaluates to a + + + align:start position:0% +expression actually evaluates to a +certain value it's not a number it + + align:start position:0% +certain value it's not a number it + + + align:start position:0% +certain value it's not a number it +evaluates to true the Boolean value true + + align:start position:0% +evaluates to true the Boolean value true + + + align:start position:0% +evaluates to true the Boolean value true +because yes two is less than + + align:start position:0% + + + + align:start position:0% + +three the equal sign here this + + align:start position:0% +three the equal sign here this + + + align:start position:0% +three the equal sign here this +notion with a double equal is how we ask + + align:start position:0% +notion with a double equal is how we ask + + + align:start position:0% +notion with a double equal is how we ask +python to tell us whether two things are + + align:start position:0% +python to tell us whether two things are + + + align:start position:0% +python to tell us whether two things are +equivalent and this will be the Boolean + + align:start position:0% +equivalent and this will be the Boolean + + + align:start position:0% +equivalent and this will be the Boolean +value + + align:start position:0% +value + + + align:start position:0% +value +false + + align:start position:0% + + + + align:start position:0% + +okay so here's a bunch of other + + align:start position:0% +okay so here's a bunch of other + + + align:start position:0% +okay so here's a bunch of other +operators that we can run on any type + + align:start position:0% +operators that we can run on any type + + + align:start position:0% +operators that we can run on any type +really in Python uh most of the most of + + align:start position:0% +really in Python uh most of the most of + + + align:start position:0% +really in Python uh most of the most of +the time we're going to run them on + + align:start position:0% +the time we're going to run them on + + + align:start position:0% +the time we're going to run them on +numbers but they can be run on strings + + align:start position:0% +numbers but they can be run on strings + + + align:start position:0% +numbers but they can be run on strings +and and things like that as well so + + align:start position:0% +and and things like that as well so + + + align:start position:0% +and and things like that as well so +obviously the double equal sign checks + + align:start position:0% +obviously the double equal sign checks + + + align:start position:0% +obviously the double equal sign checks +for equality so if I is the same as J + + align:start position:0% +for equality so if I is the same as J + + + align:start position:0% +for equality so if I is the same as J +this entire expression is replaced with + + align:start position:0% +this entire expression is replaced with + + + align:start position:0% +this entire expression is replaced with +true and if they're not equivalent this + + align:start position:0% +true and if they're not equivalent this + + + align:start position:0% +true and if they're not equivalent this +entire expression is replaced with false + + align:start position:0% +entire expression is replaced with false + + + align:start position:0% +entire expression is replaced with false +okay if we want to check for inequality + + align:start position:0% +okay if we want to check for inequality + + + align:start position:0% +okay if we want to check for inequality +we use uh not equal so exclamation mark + + align:start position:0% +we use uh not equal so exclamation mark + + + align:start position:0% +we use uh not equal so exclamation mark +equal is uh means not equal so if the + + align:start position:0% +equal is uh means not equal so if the + + + align:start position:0% +equal is uh means not equal so if the +number I or whatever V object I is not + + align:start position:0% +number I or whatever V object I is not + + + align:start position:0% +number I or whatever V object I is not +equal to object + + align:start position:0% +equal to object + + + align:start position:0% +equal to object +J then this entire expression is true if + + align:start position:0% +J then this entire expression is true if + + + align:start position:0% +J then this entire expression is true if +they are equal then theti entire + + align:start position:0% +they are equal then theti entire + + + align:start position:0% +they are equal then theti entire +expression is + + align:start position:0% +expression is + + + align:start position:0% +expression is +false and then of course we've got the + + align:start position:0% +false and then of course we've got the + + + align:start position:0% +false and then of course we've got the +uh the less than less than or equal to + + align:start position:0% +uh the less than less than or equal to + + + align:start position:0% +uh the less than less than or equal to +greater greater than or equal to um to + + align:start position:0% +greater greater than or equal to um to + + + align:start position:0% +greater greater than or equal to um to +work with this well + + align:start position:0% +work with this well + + + align:start position:0% +work with this well +we can apply these to + + align:start position:0% +we can apply these to + + + align:start position:0% +we can apply these to +Strings and uh with strings it's + + align:start position:0% +Strings and uh with strings it's + + + align:start position:0% +Strings and uh with strings it's +important to be careful about case so + + align:start position:0% +important to be careful about case so + + + align:start position:0% +important to be careful about case so +for example lower case a equivalent to + + align:start position:0% +for example lower case a equivalent to + + + align:start position:0% +for example lower case a equivalent to +uppercase a is false right because they + + align:start position:0% +uppercase a is false right because they + + + align:start position:0% +uppercase a is false right because they +are not the same + + align:start position:0% + + + + align:start position:0% + +character now that we're talking about + + align:start position:0% +character now that we're talking about + + + align:start position:0% +character now that we're talking about +Boolean operators we can actually start + + align:start position:0% +Boolean operators we can actually start + + + align:start position:0% +Boolean operators we can actually start +to combine them together so if I have + + align:start position:0% +to combine them together so if I have + + + align:start position:0% +to combine them together so if I have +the expression for example 2 less than + + align:start position:0% +the expression for example 2 less than + + + align:start position:0% +the expression for example 2 less than +three right like I wrote on the board + + align:start position:0% +three right like I wrote on the board + + + align:start position:0% +three right like I wrote on the board +that's true + + align:start position:0% +that's true + + + align:start position:0% +that's true +but I can combine that expression with + + align:start position:0% +but I can combine that expression with + + + align:start position:0% +but I can combine that expression with +another one actually by itself I can say + + align:start position:0% +another one actually by itself I can say + + + align:start position:0% +another one actually by itself I can say +what is not two less than three and that + + align:start position:0% +what is not two less than three and that + + + align:start position:0% +what is not two less than three and that +will be false right it's the opposite of + + align:start position:0% +will be false right it's the opposite of + + + align:start position:0% +will be false right it's the opposite of +it but I can also combine Boolean + + align:start position:0% +it but I can also combine Boolean + + + align:start position:0% +it but I can also combine Boolean +Expressions together so I can say what's + + align:start position:0% +Expressions together so I can say what's + + + align:start position:0% +Expressions together so I can say what's +two less than three and uh three less + + align:start position:0% +two less than three and uh three less + + + align:start position:0% +two less than three and uh three less +than + + align:start position:0% +than + + + align:start position:0% +than +four so two less than three is true + + align:start position:0% +four so two less than three is true + + + align:start position:0% +four so two less than three is true +right and three less than four is also + + align:start position:0% +right and three less than four is also + + + align:start position:0% +right and three less than four is also +true so the combination of these two + + align:start position:0% +true so the combination of these two + + + align:start position:0% +true so the combination of these two +expression of these two ring Expressions + + align:start position:0% +expression of these two ring Expressions + + + align:start position:0% +expression of these two ring Expressions +is what is true and true + + align:start position:0% +is what is true and true + + + align:start position:0% +is what is true and true +true right so if one is true and the + + align:start position:0% +true right so if one is true and the + + + align:start position:0% +true right so if one is true and the +other one is true then both of them and + + align:start position:0% +other one is true then both of them and + + + align:start position:0% +other one is true then both of them and +both of them together are going to be + + align:start position:0% +both of them together are going to be + + + align:start position:0% +both of them together are going to be +true if one of these is false so is uh + + align:start position:0% +true if one of these is false so is uh + + + align:start position:0% +true if one of these is false so is uh +three greater than four is false well + + align:start position:0% +three greater than four is false well + + + align:start position:0% +three greater than four is false well +what's false and true it's going to be + + align:start position:0% +what's false and true it's going to be + + + align:start position:0% +what's false and true it's going to be +false so if one of these operators is + + align:start position:0% +false so if one of these operators is + + + align:start position:0% +false so if one of these operators is +false then the entire expression is + + align:start position:0% +false then the entire expression is + + + align:start position:0% +false then the entire expression is +false and you don't have have to + + align:start position:0% +false and you don't have have to + + + align:start position:0% +false and you don't have have to +remember this truth table um you can + + align:start position:0% +remember this truth table um you can + + + align:start position:0% +remember this truth table um you can +always check it like I just did right + + align:start position:0% +always check it like I just did right + + + align:start position:0% +always check it like I just did right +here in the + + align:start position:0% +here in the + + + align:start position:0% +here in the +console but at a high level right when + + align:start position:0% +console but at a high level right when + + + align:start position:0% +console but at a high level right when +we're doing the and operator between two + + align:start position:0% +we're doing the and operator between two + + + align:start position:0% +we're doing the and operator between two +Boolean Expressions we need both of the + + align:start position:0% +Boolean Expressions we need both of the + + + align:start position:0% +Boolean Expressions we need both of the +Expressions to be + + align:start position:0% +Expressions to be + + + align:start position:0% +Expressions to be +true for the result and to be true the + + align:start position:0% +true for the result and to be true the + + + align:start position:0% +true for the result and to be true the +or is the other one we usually uh we we + + align:start position:0% +or is the other one we usually uh we we + + + align:start position:0% +or is the other one we usually uh we we +can usually do the or is always true + + align:start position:0% +can usually do the or is always true + + + align:start position:0% +can usually do the or is always true +except for when both of the operators + + align:start position:0% +except for when both of the operators + + + align:start position:0% +except for when both of the operators +are false right and it kind of makes + + align:start position:0% +are false right and it kind of makes + + + align:start position:0% +are false right and it kind of makes +makes sense in English too + + align:start position:0% +makes sense in English too + + + align:start position:0% +makes sense in English too +right if either operator is true then + + align:start position:0% +right if either operator is true then + + + align:start position:0% +right if either operator is true then +the entire result is true but when both + + align:start position:0% +the entire result is true but when both + + + align:start position:0% +the entire result is true but when both +are false the or of both of them is + + align:start position:0% +are false the or of both of them is + + + align:start position:0% +are false the or of both of them is +false as + + align:start position:0% +false as + + + align:start position:0% +false as +well so here's a little example uh where + + align:start position:0% +well so here's a little example uh where + + + align:start position:0% +well so here's a little example uh where +we can use these operators in Python so + + align:start position:0% +we can use these operators in Python so + + + align:start position:0% +we can use these operators in Python so +we can draw the little memory diagram as + + align:start position:0% +we can draw the little memory diagram as + + + align:start position:0% +we can draw the little memory diagram as +well so P set time is 15 there's my + + align:start position:0% +well so P set time is 15 there's my + + + align:start position:0% +well so P set time is 15 there's my +variable sleep time is eight there's my + + align:start position:0% +variable sleep time is eight there's my + + + align:start position:0% +variable sleep time is eight there's my +other variable I'm going to print sleep + + align:start position:0% +other variable I'm going to print sleep + + + align:start position:0% +other variable I'm going to print sleep +time is greater than PE at time so here + + align:start position:0% +time is greater than PE at time so here + + + align:start position:0% +time is greater than PE at time so here +my print statement is going to grab that + + align:start position:0% +my print statement is going to grab that + + + align:start position:0% +my print statement is going to grab that +expression which evaluates + + align:start position:0% +expression which evaluates + + + align:start position:0% +expression which evaluates +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +to false 8 is is less than 15 is false + + align:start position:0% +to false 8 is is less than 15 is false + + + align:start position:0% +to false 8 is is less than 15 is false +so that's going to print false and then + + align:start position:0% +so that's going to print false and then + + + align:start position:0% +so that's going to print false and then +I have two more variables these ones + + align:start position:0% +I have two more variables these ones + + + align:start position:0% +I have two more variables these ones +just happen to be booleans derive is + + align:start position:0% +just happen to be booleans derive is + + + align:start position:0% +just happen to be booleans derive is +true drink is false so drink and derive + + align:start position:0% +true drink is false so drink and derive + + + align:start position:0% +true drink is false so drink and derive +is going to be false because one of them + + align:start position:0% +is going to be false because one of them + + + align:start position:0% +is going to be false because one of them +is + + align:start position:0% +is + + + align:start position:0% +is +false and so here I've got this other + + align:start position:0% +false and so here I've got this other + + + align:start position:0% +false and so here I've got this other +variable both and then I'm going to + + align:start position:0% +variable both and then I'm going to + + + align:start position:0% +variable both and then I'm going to +print false to the console + + align:start position:0% + + + + align:start position:0% + +okay quick you try it for you guys so + + align:start position:0% +okay quick you try it for you guys so + + + align:start position:0% +okay quick you try it for you guys so +let's have you write a program that + + align:start position:0% +let's have you write a program that + + + align:start position:0% +let's have you write a program that +saves a secret number in a + + align:start position:0% +saves a secret number in a + + + align:start position:0% +saves a secret number in a +variable okay so that's going to be your + + align:start position:0% +variable okay so that's going to be your + + + align:start position:0% +variable okay so that's going to be your +program's Secrets presumably people uh + + align:start position:0% +program's Secrets presumably people uh + + + align:start position:0% +program's Secrets presumably people uh +using your program won't be looking at + + align:start position:0% +using your program won't be looking at + + + align:start position:0% +using your program won't be looking at +the program itself they'll just be + + align:start position:0% +the program itself they'll just be + + + align:start position:0% +the program itself they'll just be +interacting with the program in the + + align:start position:0% +interacting with the program in the + + + align:start position:0% +interacting with the program in the +Shell so save a secret number in a + + align:start position:0% +Shell so save a secret number in a + + + align:start position:0% +Shell so save a secret number in a +variable ask the user to guess a number + + align:start position:0% +variable ask the user to guess a number + + + align:start position:0% +variable ask the user to guess a number +and then print either true or false if + + align:start position:0% +and then print either true or false if + + + align:start position:0% +and then print either true or false if +it's the same as your secret or not so + + align:start position:0% +it's the same as your secret or not so + + + align:start position:0% +it's the same as your secret or not so +it's here in this you try it down here + + align:start position:0% +it's here in this you try it down here + + + align:start position:0% +it's here in this you try it down here +so you can start with something like + + align:start position:0% +so you can start with something like + + + align:start position:0% +so you can start with something like +secret equals and then put your favorite + + align:start position:0% +secret equals and then put your favorite + + + align:start position:0% +secret equals and then put your favorite +number there five whatever and then + + align:start position:0% +number there five whatever and then + + + align:start position:0% +number there five whatever and then +write the rest of the code so ask the + + align:start position:0% +write the rest of the code so ask the + + + align:start position:0% +write the rest of the code so ask the +user to guess a number print a Boolean + + align:start position:0% +user to guess a number print a Boolean + + + align:start position:0% +user to guess a number print a Boolean +depending on whether the guess equals + + align:start position:0% +depending on whether the guess equals + + + align:start position:0% +depending on whether the guess equals +this secret or not so I'll give you a + + align:start position:0% +this secret or not so I'll give you a + + + align:start position:0% +this secret or not so I'll give you a +couple minutes to write + + align:start position:0% + + + + align:start position:0% + +that yeah + + align:start position:0% +that yeah + + + align:start position:0% +that yeah +sorry the symbol and simar + + align:start position:0% +sorry the symbol and simar + + + align:start position:0% +sorry the symbol and simar +to if you use the symbol and it's not + + align:start position:0% +to if you use the symbol and it's not + + + align:start position:0% +to if you use the symbol and it's not +the same have to actually type out A and + + align:start position:0% +the same have to actually type out A and + + + align:start position:0% +the same have to actually type out A and +D in Python the and means something else + + align:start position:0% +D in Python the and means something else + + + align:start position:0% +D in Python the and means something else +it's like a it's an operator with the + + align:start position:0% +it's like a it's an operator with the + + + align:start position:0% +it's like a it's an operator with the +bits of the number so something it's not + + align:start position:0% +bits of the number so something it's not + + + align:start position:0% +bits of the number so something it's not +going to give the same answers + + align:start position:0% +going to give the same answers + + + align:start position:0% +going to give the same answers +yeah right you're thinking about Java or + + align:start position:0% +yeah right you're thinking about Java or + + + align:start position:0% +yeah right you're thinking about Java or +C++ or something right + + align:start position:0% + + + + align:start position:0% + +yeah all right does anyone have a start + + align:start position:0% +yeah all right does anyone have a start + + + align:start position:0% +yeah all right does anyone have a start +for me for this program how do I get + + align:start position:0% +for me for this program how do I get + + + align:start position:0% +for me for this program how do I get +grab the user input + + align:start position:0% + + + + align:start position:0% + +guess equals + + align:start position:0% + + + + align:start position:0% + +input yeah we can be nice please guess a + + align:start position:0% +input yeah we can be nice please guess a + + + align:start position:0% +input yeah we can be nice please guess a +number what's + + align:start position:0% +number what's + + + align:start position:0% +number what's +that we want the user to give us an + + align:start position:0% +that we want the user to give us an + + + align:start position:0% +that we want the user to give us an +integer yeah a number exactly + + align:start position:0% +integer yeah a number exactly + + + align:start position:0% +integer yeah a number exactly +so okay yeah if we leave it like + + align:start position:0% +so okay yeah if we leave it like + + + align:start position:0% +so okay yeah if we leave it like +that then we're just grabbing the string + + align:start position:0% +that then we're just grabbing the string + + + align:start position:0% +that then we're just grabbing the string +so we have to cast it to an integer + + align:start position:0% + + + + align:start position:0% + +exactly now + + align:start position:0% +exactly now + + + align:start position:0% +exactly now +what how do I check for equivalency + + align:start position:0% +what how do I check for equivalency + + + align:start position:0% +what how do I check for equivalency +between my secret and the + + align:start position:0% + + + + align:start position:0% + +guests + + align:start position:0% +guests + + + align:start position:0% +guests +secret equal equal + + align:start position:0% +secret equal equal + + + align:start position:0% +secret equal equal +guess and do you want to print this yeah + + align:start position:0% +guess and do you want to print this yeah + + + align:start position:0% +guess and do you want to print this yeah +let's print + + align:start position:0% + + + + align:start position:0% + +that okay run it + + align:start position:0% +that okay run it + + + align:start position:0% +that okay run it +let's guess something that's not the + + align:start position:0% +let's guess something that's not the + + + align:start position:0% +let's guess something that's not the +same false run it again let's guess + + align:start position:0% +same false run it again let's guess + + + align:start position:0% +same false run it again let's guess +something that's the same true and we + + align:start position:0% +something that's the same true and we + + + align:start position:0% +something that's the same true and we +can guess something that's lower too + + align:start position:0% + + + + align:start position:0% + +just is everyone yeah you + + align:start position:0% + + + + align:start position:0% + +assign secret equal + + align:start position:0% +assign secret equal + + + align:start position:0% +assign secret equal +yes con yep yep exactly equal equals + + align:start position:0% +yes con yep yep exactly equal equals + + + align:start position:0% +yes con yep yep exactly equal equals +this thing yep and then you can you know + + align:start position:0% +this thing yep and then you can you know + + + align:start position:0% +this thing yep and then you can you know +do whatever you want with that print + + align:start position:0% +do whatever you want with that print + + + align:start position:0% +do whatever you want with that print +equals or something that's the same but + + align:start position:0% +equals or something that's the same but + + + align:start position:0% +equals or something that's the same but +yeah you can do other things with this + + align:start position:0% +yeah you can do other things with this + + + align:start position:0% +yeah you can do other things with this +variable + + align:start position:0% +variable + + + align:start position:0% +variable +yeah exactly five + + align:start position:0% + + + + align:start position:0% + +yeah if you want at home try to see what + + align:start position:0% +yeah if you want at home try to see what + + + align:start position:0% +yeah if you want at home try to see what +would have happened if you didn't cast + + align:start position:0% +would have happened if you didn't cast + + + align:start position:0% +would have happened if you didn't cast +it to an + + align:start position:0% +it to an + + + align:start position:0% +it to an +integer uh see if the program would have + + align:start position:0% +integer uh see if the program would have + + + align:start position:0% +integer uh see if the program would have +crashed or not or if it would have just + + align:start position:0% +crashed or not or if it would have just + + + align:start position:0% +crashed or not or if it would have just +you know worked but given a wrong answer + + align:start position:0% +you know worked but given a wrong answer + + + align:start position:0% +you know worked but given a wrong answer +so why do we do booleans right booleans + + align:start position:0% +so why do we do booleans right booleans + + + align:start position:0% +so why do we do booleans right booleans +are important variables because they + + align:start position:0% +are important variables because they + + + align:start position:0% +are important variables because they +allow us to start thinking about writing + + align:start position:0% +allow us to start thinking about writing + + + align:start position:0% +allow us to start thinking about writing +programs that make decisions right the + + align:start position:0% +programs that make decisions right the + + + align:start position:0% +programs that make decisions right the +way we talk is you know we can say + + align:start position:0% +way we talk is you know we can say + + + align:start position:0% +way we talk is you know we can say +something like if this is true do this + + align:start position:0% +something like if this is true do this + + + align:start position:0% +something like if this is true do this +otherwise do this the Boolean part is if + + align:start position:0% +otherwise do this the Boolean part is if + + + align:start position:0% +otherwise do this the Boolean part is if +that something is true right so the + + align:start position:0% +that something is true right so the + + + align:start position:0% +that something is true right so the +something is true is going to be the the + + align:start position:0% +something is true is going to be the the + + + align:start position:0% +something is true is going to be the the +Boolean that we can create in our + + align:start position:0% +Boolean that we can create in our + + + align:start position:0% +Boolean that we can create in our +programs and then the do this is some + + align:start position:0% +programs and then the do this is some + + + align:start position:0% +programs and then the do this is some +sort of commands and then the otherwise + + align:start position:0% +sort of commands and then the otherwise + + + align:start position:0% +sort of commands and then the otherwise +do that is going to be some other set of + + align:start position:0% +do that is going to be some other set of + + + align:start position:0% +do that is going to be some other set of +commands Okay so a really simple uh you + + align:start position:0% +commands Okay so a really simple uh you + + + align:start position:0% +commands Okay so a really simple uh you +know Boolean expression could be it's + + align:start position:0% +know Boolean expression could be it's + + + align:start position:0% +know Boolean expression could be it's +midnight you get a free food email do + + align:start position:0% +midnight you get a free food email do + + + align:start position:0% +midnight you get a free food email do +you go get the free food or do you sleep + + align:start position:0% +you go get the free food or do you sleep + + + align:start position:0% +you go get the free food or do you sleep +right that's the very simplest kind of + + align:start position:0% +right that's the very simplest kind of + + + align:start position:0% +right that's the very simplest kind of +decision point you can make but with + + align:start position:0% +decision point you can make but with + + + align:start position:0% +decision point you can make but with +conditionals you can actually write a + + align:start position:0% +conditionals you can actually write a + + + align:start position:0% +conditionals you can actually write a +pretty cool program that gets you to + + align:start position:0% +pretty cool program that gets you to + + + align:start position:0% +pretty cool program that gets you to +that free food right so let's say this + + align:start position:0% +that free food right so let's say this + + + align:start position:0% +that free food right so let's say this +is a map of MIT this is where you are + + align:start position:0% +is a map of MIT this is where you are + + + align:start position:0% +is a map of MIT this is where you are +that's where the free food is okay we + + align:start position:0% +that's where the free food is okay we + + + align:start position:0% +that's where the free food is okay we +can write a really simple algorithm + + align:start position:0% +can write a really simple algorithm + + + align:start position:0% +can write a really simple algorithm +using just conditionals that takes you + + align:start position:0% +using just conditionals that takes you + + + align:start position:0% +using just conditionals that takes you +to that free food so the algorithm goes + + align:start position:0% +to that free food so the algorithm goes + + + align:start position:0% +to that free food so the algorithm goes +like this so I'm going to say I'm going + + align:start position:0% +like this so I'm going to say I'm going + + + align:start position:0% +like this so I'm going to say I'm going +to walk always you know in this + + align:start position:0% +to walk always you know in this + + + align:start position:0% +to walk always you know in this +direction so I'm either going forward + + align:start position:0% +direction so I'm either going forward + + + align:start position:0% +direction so I'm either going forward +backward left and right I'm not turning + + align:start position:0% +backward left and right I'm not turning + + + align:start position:0% +backward left and right I'm not turning +and I'm going to say the algorithm is + + align:start position:0% +and I'm going to say the algorithm is + + + align:start position:0% +and I'm going to say the algorithm is +always going to have my right hand be on + + align:start position:0% +always going to have my right hand be on + + + align:start position:0% +always going to have my right hand be on +a wall so if the right is clear so + + align:start position:0% +a wall so if the right is clear so + + + align:start position:0% +a wall so if the right is clear so +standing here my right is clear so I'm + + align:start position:0% +standing here my right is clear so I'm + + + align:start position:0% +standing here my right is clear so I'm +just going to keep shimming until I + + align:start position:0% +just going to keep shimming until I + + + align:start position:0% +just going to keep shimming until I +reach a wall if my right is blocked but + + align:start position:0% +reach a wall if my right is blocked but + + + align:start position:0% +reach a wall if my right is blocked but +my forward is clear I'm going to keep + + align:start position:0% +my forward is clear I'm going to keep + + + align:start position:0% +my forward is clear I'm going to keep +going like this all the way to the end + + align:start position:0% +going like this all the way to the end + + + align:start position:0% +going like this all the way to the end +of this uh the the um the the the um the + + align:start position:0% +of this uh the the um the the the um the + + + align:start position:0% +of this uh the the um the the the um the +room if my right is blocked and my + + align:start position:0% +room if my right is blocked and my + + + align:start position:0% +room if my right is blocked and my +forward is blocked right as if I would + + align:start position:0% +forward is blocked right as if I would + + + align:start position:0% +forward is blocked right as if I would +have reached the end of the room I would + + align:start position:0% +have reached the end of the room I would + + + align:start position:0% +have reached the end of the room I would +have gone to the left and if my right + + align:start position:0% +have gone to the left and if my right + + + align:start position:0% +have gone to the left and if my right +forward and left is blocked if I'm over + + align:start position:0% +forward and left is blocked if I'm over + + + align:start position:0% +forward and left is blocked if I'm over +there I would go backward right so I'd + + align:start position:0% +there I would go backward right so I'd + + + align:start position:0% +there I would go backward right so I'd +go backward so basically starting from + + align:start position:0% +go backward so basically starting from + + + align:start position:0% +go backward so basically starting from +here I've made my way all the way around + + align:start position:0% +here I've made my way all the way around + + + align:start position:0% +here I've made my way all the way around +this room and I would go out the door + + align:start position:0% +this room and I would go out the door + + + align:start position:0% +this room and I would go out the door +down the hallway right and if the map of + + align:start position:0% +down the hallway right and if the map of + + + align:start position:0% +down the hallway right and if the map of +MIT doesn't have Islands so if the free + + align:start position:0% +MIT doesn't have Islands so if the free + + + align:start position:0% +MIT doesn't have Islands so if the free +food isn't somewhere sort of in an + + align:start position:0% +food isn't somewhere sort of in an + + + align:start position:0% +food isn't somewhere sort of in an +island in the middle here if it's just a + + align:start position:0% +island in the middle here if it's just a + + + align:start position:0% +island in the middle here if it's just a +a regular old maze I would eventually + + align:start position:0% +a regular old maze I would eventually + + + align:start position:0% +a regular old maze I would eventually +make my way to the free food following + + align:start position:0% +make my way to the free food following + + + align:start position:0% +make my way to the free food following +this really simple conditional + + align:start position:0% + + + + align:start position:0% + +algorithm so how do we actually do + + align:start position:0% +algorithm so how do we actually do + + + align:start position:0% +algorithm so how do we actually do +conditionals in Python how do we tell + + align:start position:0% +conditionals in Python how do we tell + + + align:start position:0% +conditionals in Python how do we tell +python hey I want to create I want to + + align:start position:0% +python hey I want to create I want to + + + align:start position:0% +python hey I want to create I want to +insert a decision point right here we do + + align:start position:0% +insert a decision point right here we do + + + align:start position:0% +insert a decision point right here we do +that using the keyword if and the if + + align:start position:0% +that using the keyword if and the if + + + align:start position:0% +that using the keyword if and the if +starts a decision + + align:start position:0% +starts a decision + + + align:start position:0% +starts a decision +block now the simplest decision block is + + align:start position:0% +block now the simplest decision block is + + + align:start position:0% +block now the simplest decision block is +just an if by itself so if python sees + + align:start position:0% +just an if by itself so if python sees + + + align:start position:0% +just an if by itself so if python sees +that if so there's some code that it's + + align:start position:0% +that if so there's some code that it's + + + align:start position:0% +that if so there's some code that it's +following and then at some point it + + align:start position:0% +following and then at some point it + + + align:start position:0% +following and then at some point it +reaches the if the condition tells + + align:start position:0% +reaches the if the condition tells + + + align:start position:0% +reaches the if the condition tells +python uh to to check whether that + + align:start position:0% +python uh to to check whether that + + + align:start position:0% +python uh to to check whether that +condition is true if the condition is + + align:start position:0% +condition is true if the condition is + + + align:start position:0% +condition is true if the condition is +true so this is our decision point then + + align:start position:0% +true so this is our decision point then + + + align:start position:0% +true so this is our decision point then +I'm going to deviate from my main + + align:start position:0% +I'm going to deviate from my main + + + align:start position:0% +I'm going to deviate from my main +program and potential and and do the + + align:start position:0% +program and potential and and do the + + + align:start position:0% +program and potential and and do the +code that's part of that + + align:start position:0% +code that's part of that + + + align:start position:0% +code that's part of that +condition those I guess two lines dot + + align:start position:0% +condition those I guess two lines dot + + + align:start position:0% +condition those I guess two lines dot +dot dot inside there if the condition is + + align:start position:0% +dot dot inside there if the condition is + + + align:start position:0% +dot dot inside there if the condition is +not false I'm not going to go that route + + align:start position:0% +not false I'm not going to go that route + + + align:start position:0% +not false I'm not going to go that route +and I'll just keep following the rest of + + align:start position:0% +and I'll just keep following the rest of + + + align:start position:0% +and I'll just keep following the rest of +main + + align:start position:0% +main + + + align:start position:0% +main +program how does python know how many + + align:start position:0% +program how does python know how many + + + align:start position:0% +program how does python know how many +code code lines to execute that's part + + align:start position:0% +code code lines to execute that's part + + + align:start position:0% +code code lines to execute that's part +of that condition well it looks at the + + align:start position:0% +of that condition well it looks at the + + + align:start position:0% +of that condition well it looks at the +indentation so notice here I've kind of + + align:start position:0% +indentation so notice here I've kind of + + + align:start position:0% +indentation so notice here I've kind of +put a few spaces and for these two and + + align:start position:0% +put a few spaces and for these two and + + + align:start position:0% +put a few spaces and for these two and +dot dot dot code blocks here anything + + align:start position:0% +dot dot dot code blocks here anything + + + align:start position:0% +dot dot dot code blocks here anything +that's indented right after that if + + align:start position:0% +that's indented right after that if + + + align:start position:0% +that's indented right after that if +statement and that colon there is a a + + align:start position:0% +statement and that colon there is a a + + + align:start position:0% +statement and that colon there is a a +set of commands that are part of that + + align:start position:0% +set of commands that are part of that + + + align:start position:0% +set of commands that are part of that +block so anything here will get executed + + align:start position:0% +block so anything here will get executed + + + align:start position:0% +block so anything here will get executed +all at + + align:start position:0% +all at + + + align:start position:0% +all at +once and that's a really simple if + + align:start position:0% +once and that's a really simple if + + + align:start position:0% +once and that's a really simple if +either you do this set of commands extra + + align:start position:0% +either you do this set of commands extra + + + align:start position:0% +either you do this set of commands extra +commands if the condition is true or you + + align:start position:0% +commands if the condition is true or you + + + align:start position:0% +commands if the condition is true or you +don't now you can add an exception to + + align:start position:0% +don't now you can add an exception to + + + align:start position:0% +don't now you can add an exception to +that so if the condition is true again + + align:start position:0% +that so if the condition is true again + + + align:start position:0% +that so if the condition is true again +we're following the program we reach + + align:start position:0% +we're following the program we reach + + + align:start position:0% +we're following the program we reach +this if conditional here if the + + align:start position:0% +this if conditional here if the + + + align:start position:0% +this if conditional here if the +condition is true again we're going to + + align:start position:0% +condition is true again we're going to + + + align:start position:0% +condition is true again we're going to +deviate from the program and execute + + align:start position:0% +deviate from the program and execute + + + align:start position:0% +deviate from the program and execute +this other set of commands right + + align:start position:0% +this other set of commands right + + + align:start position:0% +this other set of commands right +here otherwise the condition is not true + + align:start position:0% +here otherwise the condition is not true + + + align:start position:0% +here otherwise the condition is not true +and we're going to execute this other + + align:start position:0% +and we're going to execute this other + + + align:start position:0% +and we're going to execute this other +set of commands over here so these guys + + align:start position:0% +set of commands over here so these guys + + + align:start position:0% +set of commands over here so these guys +over here so either we do this set of + + align:start position:0% +over here so either we do this set of + + + align:start position:0% +over here so either we do this set of +commands or the other set of commands + + align:start position:0% +commands or the other set of commands + + + align:start position:0% +commands or the other set of commands +but we never do both and we never skip + + align:start position:0% +but we never do both and we never skip + + + align:start position:0% +but we never do both and we never skip +both of them so either we do one set or + + align:start position:0% +both of them so either we do one set or + + + align:start position:0% +both of them so either we do one set or +the other when we're done executing all + + align:start position:0% +the other when we're done executing all + + + align:start position:0% +the other when we're done executing all +the indented Blocks part of the + + align:start position:0% +the indented Blocks part of the + + + align:start position:0% +the indented Blocks part of the +condition or the other one that's that + + align:start position:0% +condition or the other one that's that + + + align:start position:0% +condition or the other one that's that +if the condition wasn't true then we + + align:start position:0% +if the condition wasn't true then we + + + align:start position:0% +if the condition wasn't true then we +rejoin the rest of the program and + + align:start position:0% +rejoin the rest of the program and + + + align:start position:0% +rejoin the rest of the program and +continue executing so this is all the + + align:start position:0% +continue executing so this is all the + + + align:start position:0% +continue executing so this is all the +rest of the program is at the same + + align:start position:0% +rest of the program is at the same + + + align:start position:0% +rest of the program is at the same +indentation level as our original if and + + align:start position:0% +indentation level as our original if and + + + align:start position:0% +indentation level as our original if and +else we can add a whole bunch of + + align:start position:0% +else we can add a whole bunch of + + + align:start position:0% +else we can add a whole bunch of +conditions right not just an if do this + + align:start position:0% +conditions right not just an if do this + + + align:start position:0% +conditions right not just an if do this +otherwise do this we can actually + + align:start position:0% +otherwise do this we can actually + + + align:start position:0% +otherwise do this we can actually +add a bunch of things to check using L + + align:start position:0% +add a bunch of things to check using L + + + align:start position:0% +add a bunch of things to check using L +if which basically stands for else if + + align:start position:0% +if which basically stands for else if + + + align:start position:0% +if which basically stands for else if +another condition do this so here's our + + align:start position:0% +another condition do this so here's our + + + align:start position:0% +another condition do this so here's our +program we reach a decision point if the + + align:start position:0% +program we reach a decision point if the + + + align:start position:0% +program we reach a decision point if the +condition is true like before we'll + + align:start position:0% +condition is true like before we'll + + + align:start position:0% +condition is true like before we'll +execute the set of commands but + + align:start position:0% +execute the set of commands but + + + align:start position:0% +execute the set of commands but +otherwise the condition is not + + align:start position:0% +otherwise the condition is not + + + align:start position:0% +otherwise the condition is not +true we're going to check another + + align:start position:0% +true we're going to check another + + + align:start position:0% +true we're going to check another +condition + + align:start position:0% +condition + + + align:start position:0% +condition +else if this other condition is is true + + align:start position:0% +else if this other condition is is true + + + align:start position:0% +else if this other condition is is true +we'll execute this other set of commands + + align:start position:0% +we'll execute this other set of commands + + + align:start position:0% +we'll execute this other set of commands +otherwise here's another elsf we'll + + align:start position:0% +otherwise here's another elsf we'll + + + align:start position:0% +otherwise here's another elsf we'll +check another condition if it's true + + align:start position:0% +check another condition if it's true + + + align:start position:0% +check another condition if it's true +we'll execute some other set of commands + + align:start position:0% +we'll execute some other set of commands + + + align:start position:0% +we'll execute some other set of commands +otherwise there can be more L ifs and at + + align:start position:0% +otherwise there can be more L ifs and at + + + align:start position:0% +otherwise there can be more L ifs and at +some point we're going to rejoin the + + align:start position:0% +some point we're going to rejoin the + + + align:start position:0% +some point we're going to rejoin the +rest of the + + align:start position:0% +rest of the + + + align:start position:0% +rest of the +program now these L ifs are going to be + + align:start position:0% +program now these L ifs are going to be + + + align:start position:0% +program now these L ifs are going to be +each condition is checked one at a time + + align:start position:0% +each condition is checked one at a time + + + align:start position:0% +each condition is checked one at a time +the very first one that's true is the + + align:start position:0% +the very first one that's true is the + + + align:start position:0% +the very first one that's true is the +one that gets executed we're never going + + align:start position:0% +one that gets executed we're never going + + + align:start position:0% +one that gets executed we're never going +to execute more than one right because + + align:start position:0% +to execute more than one right because + + + align:start position:0% +to execute more than one right because +this is an if else if else if else if so + + align:start position:0% +this is an if else if else if else if so + + + align:start position:0% +this is an if else if else if else if so +even in English you're only going to do + + align:start position:0% +even in English you're only going to do + + + align:start position:0% +even in English you're only going to do +one of these right you're never going to + + align:start position:0% +one of these right you're never going to + + + align:start position:0% +one of these right you're never going to +do all of them it is possible to skip + + align:start position:0% +do all of them it is possible to skip + + + align:start position:0% +do all of them it is possible to skip +all of them though because if none of + + align:start position:0% +all of them though because if none of + + + align:start position:0% +all of them though because if none of +those conditions are true you just don't + + align:start position:0% +those conditions are true you just don't + + + align:start position:0% +those conditions are true you just don't +do any of them if more than one is true + + align:start position:0% +do any of them if more than one is true + + + align:start position:0% +do any of them if more than one is true +you do the first one that is + + align:start position:0% +you do the first one that is + + + align:start position:0% +you do the first one that is +true if you want to have sort of a + + align:start position:0% +true if you want to have sort of a + + + align:start position:0% +true if you want to have sort of a +catchall kind of version of the middle L + + align:start position:0% +catchall kind of version of the middle L + + + align:start position:0% +catchall kind of version of the middle L +if L if L if L if you just add an else + + align:start position:0% +if L if L if L if you just add an else + + + align:start position:0% +if L if L if L if you just add an else +at the end so if none of those condition + + align:start position:0% +at the end so if none of those condition + + + align:start position:0% +at the end so if none of those condition +are true you can add an else which says + + align:start position:0% +are true you can add an else which says + + + align:start position:0% +are true you can add an else which says +you just do this if nothing is + + align:start position:0% +you just do this if nothing is + + + align:start position:0% +you just do this if nothing is +true okay kind of like what we had over + + align:start position:0% +true okay kind of like what we had over + + + align:start position:0% +true okay kind of like what we had over +here if this one otherwise do this well + + align:start position:0% +here if this one otherwise do this well + + + align:start position:0% +here if this one otherwise do this well +if any of these conditions are true do + + align:start position:0% +if any of these conditions are true do + + + align:start position:0% +if any of these conditions are true do +one of them otherwise do this + + align:start position:0% + + + + align:start position:0% + +thing so here's an example we've got + + align:start position:0% +thing so here's an example we've got + + + align:start position:0% +thing so here's an example we've got +piece at time we'll just put some + + align:start position:0% +piece at time we'll just put some + + + align:start position:0% +piece at time we'll just put some +variables in there sleep time we'll put + + align:start position:0% +variables in there sleep time we'll put + + + align:start position:0% +variables in there sleep time we'll put +some variables in there and run it see + + align:start position:0% +some variables in there and run it see + + + align:start position:0% +some variables in there and run it see +what we get I've got one code block here + + align:start position:0% +what we get I've got one code block here + + + align:start position:0% +what we get I've got one code block here +and if if and an else so the first code + + align:start position:0% +and if if and an else so the first code + + + align:start position:0% +and if if and an else so the first code +block the condition is it checks that + + align:start position:0% +block the condition is it checks that + + + align:start position:0% +block the condition is it checks that +the the sum of those two is greater than + + align:start position:0% +the the sum of those two is greater than + + + align:start position:0% +the the sum of those two is greater than +24 and it does something this is the + + align:start position:0% +24 and it does something this is the + + + align:start position:0% +24 and it does something this is the +block that's part of that condition + + align:start position:0% +block that's part of that condition + + + align:start position:0% +block that's part of that condition +notice it's indented by usually four + + align:start position:0% +notice it's indented by usually four + + + align:start position:0% +notice it's indented by usually four +spaces L if so if this one was not true + + align:start position:0% +spaces L if so if this one was not true + + + align:start position:0% +spaces L if so if this one was not true +then I'm going to go ahead and check the + + align:start position:0% +then I'm going to go ahead and check the + + + align:start position:0% +then I'm going to go ahead and check the +next one uh the next condition is that + + align:start position:0% +next one uh the next condition is that + + + align:start position:0% +next one uh the next condition is that +the addition is greater than or equal to + + align:start position:0% +the addition is greater than or equal to + + + align:start position:0% +the addition is greater than or equal to +24 and then we're going to do this print + + align:start position:0% +24 and then we're going to do this print + + + align:start position:0% +24 and then we're going to do this print +statement + + align:start position:0% +statement + + + align:start position:0% +statement +here and if neither of those are true + + align:start position:0% +here and if neither of those are true + + + align:start position:0% +here and if neither of those are true +I'm going to do whatever is in in this + + align:start position:0% +I'm going to do whatever is in in this + + + align:start position:0% +I'm going to do whatever is in in this +code block here I'm going to do these + + align:start position:0% +code block here I'm going to do these + + + align:start position:0% +code block here I'm going to do these +two lines okay so this is my sort of I + + align:start position:0% +two lines okay so this is my sort of I + + + align:start position:0% +two lines okay so this is my sort of I +call it a catchall because none of those + + align:start position:0% +call it a catchall because none of those + + + align:start position:0% +call it a catchall because none of those +other conditions were true so we're + + align:start position:0% +other conditions were true so we're + + + align:start position:0% +other conditions were true so we're +going to catch ourselves and do this PR + + align:start position:0% +going to catch ourselves and do this PR + + + align:start position:0% +going to catch ourselves and do this PR +uh do these commands here and otherwise + + align:start position:0% +uh do these commands here and otherwise + + + align:start position:0% +uh do these commands here and otherwise +uh once we finish doing either this one + + align:start position:0% +uh once we finish doing either this one + + + align:start position:0% +uh once we finish doing either this one +or this one or catching whatever is left + + align:start position:0% +or this one or catching whatever is left + + + align:start position:0% +or this one or catching whatever is left +over in here we're going to evaluate the + + align:start position:0% +over in here we're going to evaluate the + + + align:start position:0% +over in here we're going to evaluate the +print statement here and I'm going to + + align:start position:0% +print statement here and I'm going to + + + align:start position:0% +print statement here and I'm going to +print end of day because this is the + + align:start position:0% +print end of day because this is the + + + align:start position:0% +print end of day because this is the +rest of my program notice it's at the + + align:start position:0% +rest of my program notice it's at the + + + align:start position:0% +rest of my program notice it's at the +same indentation level as my original + + align:start position:0% +same indentation level as my original + + + align:start position:0% +same indentation level as my original +program + + align:start position:0% +program + + + align:start position:0% +program +so here + + align:start position:0% +so here + + + align:start position:0% +so here +is this oops this + + align:start position:0% +is this oops this + + + align:start position:0% +is this oops this +program so if uh piece at time and sleep + + align:start position:0% +program so if uh piece at time and sleep + + + align:start position:0% +program so if uh piece at time and sleep +time is uh 22 and 8 right the addition + + align:start position:0% +time is uh 22 and 8 right the addition + + + align:start position:0% +time is uh 22 and 8 right the addition +is more than 24 so this is going to + + align:start position:0% +is more than 24 so this is going to + + + align:start position:0% +is more than 24 so this is going to +enter this code block here and print + + align:start position:0% +enter this code block here and print + + + align:start position:0% +enter this code block here and print +impossible if it's exactly equal to 24 + + align:start position:0% +impossible if it's exactly equal to 24 + + + align:start position:0% +impossible if it's exactly equal to 24 +right so 22 and two we're not going to + + align:start position:0% +right so 22 and two we're not going to + + + align:start position:0% +right so 22 and two we're not going to +enter this one but we will will enter + + align:start position:0% +enter this one but we will will enter + + + align:start position:0% +enter this one but we will will enter +this one right because it's exactly + + align:start position:0% +this one right because it's exactly + + + align:start position:0% +this one right because it's exactly +equal to it's not greater than so then + + align:start position:0% +equal to it's not greater than so then + + + align:start position:0% +equal to it's not greater than so then +we're going to print full schedule and + + align:start position:0% +we're going to print full schedule and + + + align:start position:0% +we're going to print full schedule and +then rejoin the rest of the program here + + align:start position:0% +then rejoin the rest of the program here + + + align:start position:0% +then rejoin the rest of the program here +and print end of + + align:start position:0% +and print end of + + + align:start position:0% +and print end of +day and otherwise if this is something + + align:start position:0% +day and otherwise if this is something + + + align:start position:0% +day and otherwise if this is something +low right less than 24 and not equal to + + align:start position:0% +low right less than 24 and not equal to + + + align:start position:0% +low right less than 24 and not equal to +24 right so neither of these conditions + + align:start position:0% +24 right so neither of these conditions + + + align:start position:0% +24 right so neither of these conditions +are true then we're going to enter the + + align:start position:0% +are true then we're going to enter the + + + align:start position:0% +are true then we're going to enter the +else and we're going to evaluate uh or + + align:start position:0% +else and we're going to evaluate uh or + + + align:start position:0% +else and we're going to evaluate uh or +run these two lines of code here so the + + align:start position:0% +run these two lines of code here so the + + + align:start position:0% +run these two lines of code here so the +two lines of code here are going to grab + + align:start position:0% +two lines of code here are going to grab + + + align:start position:0% +two lines of code here are going to grab +the absolute value of 24 minus the P set + + align:start position:0% +the absolute value of 24 minus the P set + + + align:start position:0% +the absolute value of 24 minus the P set +time minus the sleep time figuring out + + align:start position:0% +time minus the sleep time figuring out + + + align:start position:0% +time minus the sleep time figuring out +how much time we have left in the day + + align:start position:0% +how much time we have left in the day + + + align:start position:0% +how much time we have left in the day +it's also going to print this line here + + align:start position:0% +it's also going to print this line here + + + align:start position:0% +it's also going to print this line here +and then rejoin the rest of the program + + align:start position:0% +and then rejoin the rest of the program + + + align:start position:0% +and then rejoin the rest of the program +to print end of + + align:start position:0% + + + + align:start position:0% + +day okay Quick Check nothing to run + + align:start position:0% +day okay Quick Check nothing to run + + + align:start position:0% +day okay Quick Check nothing to run +nothing to write here nothing to run + + align:start position:0% +nothing to write here nothing to run + + + align:start position:0% +nothing to write here nothing to run +think about this program what is wrong + + align:start position:0% +think about this program what is wrong + + + align:start position:0% +think about this program what is wrong +with + + align:start position:0% + + + + align:start position:0% + +it so I'm grabbing a number for x a + + align:start position:0% +it so I'm grabbing a number for x a + + + align:start position:0% +it so I'm grabbing a number for x a +number for y and I'm checking if x is + + align:start position:0% +number for y and I'm checking if x is + + + align:start position:0% +number for y and I'm checking if x is +the same as y I'm printing X is the same + + align:start position:0% +the same as y I'm printing X is the same + + + align:start position:0% +the same as y I'm printing X is the same +as y so if I give it five and five I'm + + align:start position:0% +as y so if I give it five and five I'm + + + align:start position:0% +as y so if I give it five and five I'm +going to print five is the same as five + + align:start position:0% +going to print five is the same as five + + + align:start position:0% +going to print five is the same as five +and then I'd also like to print these + + align:start position:0% +and then I'd also like to print these + + + align:start position:0% +and then I'd also like to print these +are equal what's the problem with this + + align:start position:0% +are equal what's the problem with this + + + align:start position:0% +are equal what's the problem with this +program yeah if X is not equal to Y it's + + align:start position:0% +program yeah if X is not equal to Y it's + + + align:start position:0% +program yeah if X is not equal to Y it's +still going to print these are equal + + align:start position:0% +still going to print these are equal + + + align:start position:0% +still going to print these are equal +it's not ined exactly if X is not the + + align:start position:0% +it's not ined exactly if X is not the + + + align:start position:0% +it's not ined exactly if X is not the +same as y we rejoin the rest of a + + align:start position:0% +same as y we rejoin the rest of a + + + align:start position:0% +same as y we rejoin the rest of a +program because the indentation level of + + align:start position:0% +program because the indentation level of + + + align:start position:0% +program because the indentation level of +this print statement is the same as the + + align:start position:0% +this print statement is the same as the + + + align:start position:0% +this print statement is the same as the +rest of our program so how do we fix + + align:start position:0% + + + + align:start position:0% + +it indent yep we'll just indent that + + align:start position:0% +it indent yep we'll just indent that + + + align:start position:0% +it indent yep we'll just indent that +print statement in to be at the same + + align:start position:0% +print statement in to be at the same + + + align:start position:0% +print statement in to be at the same +level as the if + + align:start position:0% + + + + align:start position:0% + +statement so we can actually Nest + + align:start position:0% +statement so we can actually Nest + + + align:start position:0% +statement so we can actually Nest +indentation statement uh we can Nest uh + + align:start position:0% +indentation statement uh we can Nest uh + + + align:start position:0% +indentation statement uh we can Nest uh +conditionals right because once we've + + align:start position:0% +conditionals right because once we've + + + align:start position:0% +conditionals right because once we've +created a conditional it's just a code + + align:start position:0% +created a conditional it's just a code + + + align:start position:0% +created a conditional it's just a code +block so here I've got an if statement + + align:start position:0% +block so here I've got an if statement + + + align:start position:0% +block so here I've got an if statement +with its own code block and inside that + + align:start position:0% +with its own code block and inside that + + + align:start position:0% +with its own code block and inside that +code block I can actually have more if + + align:start position:0% +code block I can actually have more if + + + align:start position:0% +code block I can actually have more if +statements that are just going to be + + align:start position:0% +statements that are just going to be + + + align:start position:0% +statements that are just going to be +executed whenever this condition is + + align:start position:0% +executed whenever this condition is + + + align:start position:0% +executed whenever this condition is +true so this is the insided code block + + align:start position:0% +true so this is the insided code block + + + align:start position:0% +true so this is the insided code block +so for example the the the place where + + align:start position:0% +so for example the the the place where + + + align:start position:0% +so for example the the the place where +we would execute this inner code block + + align:start position:0% +we would execute this inner code block + + + align:start position:0% +we would execute this inner code block +is when X and Y are equivalent right + + align:start position:0% +is when X and Y are equivalent right + + + align:start position:0% +is when X and Y are equivalent right +because then I'm going to enter this + + align:start position:0% +because then I'm going to enter this + + + align:start position:0% +because then I'm going to enter this +code block here this is true I'm going + + align:start position:0% +code block here this is true I'm going + + + align:start position:0% +code block here this is true I'm going +to print X and Y are equal and then this + + align:start position:0% +to print X and Y are equal and then this + + + align:start position:0% +to print X and Y are equal and then this +second co uh conditional here Y is not + + align:start position:0% +second co uh conditional here Y is not + + + align:start position:0% +second co uh conditional here Y is not +equal to zero is also + + align:start position:0% +equal to zero is also + + + align:start position:0% +equal to zero is also +true and then I'm going to print this + + align:start position:0% +true and then I'm going to print this + + + align:start position:0% +true and then I'm going to print this +one as + + align:start position:0% +one as + + + align:start position:0% +one as +well right I've already done one of the + + align:start position:0% +well right I've already done one of the + + + align:start position:0% +well right I've already done one of the +conditionals they're true so I'm going + + align:start position:0% +conditionals they're true so I'm going + + + align:start position:0% +conditionals they're true so I'm going +to skip the L if and skip the else and + + align:start position:0% +to skip the L if and skip the else and + + + align:start position:0% +to skip the L if and skip the else and +I'm going to rejoin the rest of the + + align:start position:0% +I'm going to rejoin the rest of the + + + align:start position:0% +I'm going to rejoin the rest of the +program all the other cases right when + + align:start position:0% +program all the other cases right when + + + align:start position:0% +program all the other cases right when +one uh value is different than the other + + align:start position:0% +one uh value is different than the other + + + align:start position:0% +one uh value is different than the other +will either take me here in the + + align:start position:0% +will either take me here in the + + + align:start position:0% +will either take me here in the +else and then rejoin the rest of the + + align:start position:0% +else and then rejoin the rest of the + + + align:start position:0% +else and then rejoin the rest of the +program or when they're equivalent I'm + + align:start position:0% +program or when they're equivalent I'm + + + align:start position:0% +program or when they're equivalent I'm +going or you know here I don't have I + + align:start position:0% +going or you know here I don't have I + + + align:start position:0% +going or you know here I don't have I +don't actually have a case for that on + + align:start position:0% +don't actually have a case for that on + + + align:start position:0% +don't actually have a case for that on +on the slides but when they're + + align:start position:0% +on the slides but when they're + + + align:start position:0% +on the slides but when they're +equivalent and one and Y is equal to + + align:start position:0% +equivalent and one and Y is equal to + + + align:start position:0% +equivalent and one and Y is equal to +zero I'm not actually going to enter + + align:start position:0% +zero I'm not actually going to enter + + + align:start position:0% +zero I'm not actually going to enter +this inner conditional right because y + + align:start position:0% +this inner conditional right because y + + + align:start position:0% +this inner conditional right because y +while X and Y were true were equivalent + + align:start position:0% +while X and Y were true were equivalent + + + align:start position:0% +while X and Y were true were equivalent +which is true y was equal to zero so + + align:start position:0% +which is true y was equal to zero so + + + align:start position:0% +which is true y was equal to zero so +that not equal to zero is + + align:start position:0% +that not equal to zero is + + + align:start position:0% +that not equal to zero is +false just that + + align:start position:0% +false just that + + + align:start position:0% +false just that +word and then we rejoin the rest of the + + align:start position:0% +word and then we rejoin the rest of the + + + align:start position:0% +word and then we rejoin the rest of the +program yeah what did you do the flo + + align:start position:0% +program yeah what did you do the flo + + + align:start position:0% +program yeah what did you do the flo +for oh I'm casting the numbers to floats + + align:start position:0% +for oh I'm casting the numbers to floats + + + align:start position:0% +for oh I'm casting the numbers to floats +I could cast them to ins as well yeah + + align:start position:0% +I could cast them to ins as well yeah + + + align:start position:0% +I could cast them to ins as well yeah +yeah just so I'm not comparing strings + + align:start position:0% +yeah just so I'm not comparing strings + + + align:start position:0% +yeah just so I'm not comparing strings +yeah so now that I've introduced + + align:start position:0% +yeah so now that I've introduced + + + align:start position:0% +yeah so now that I've introduced +conditionals it's important to do a + + align:start position:0% +conditionals it's important to do a + + + align:start position:0% +conditionals it's important to do a +little bit more practice to get a mental + + align:start position:0% +little bit more practice to get a mental + + + align:start position:0% +little bit more practice to get a mental +model oops a mental model of how to + + align:start position:0% +model oops a mental model of how to + + + align:start position:0% +model oops a mental model of how to +trace the code right and the the visual + + align:start position:0% +trace the code right and the the visual + + + align:start position:0% +trace the code right and the the visual +structure of the code actually helps a + + align:start position:0% +structure of the code actually helps a + + + align:start position:0% +structure of the code actually helps a +lot and python is unique in the sense + + align:start position:0% +lot and python is unique in the sense + + + align:start position:0% +lot and python is unique in the sense +there's no other languages that actually + + align:start position:0% +there's no other languages that actually + + + align:start position:0% +there's no other languages that actually +force you to indent things so the other + + align:start position:0% +force you to indent things so the other + + + align:start position:0% +force you to indent things so the other +anges don't really force you to have + + align:start position:0% +anges don't really force you to have + + + align:start position:0% +anges don't really force you to have +this visual structure to match exactly + + align:start position:0% +this visual structure to match exactly + + + align:start position:0% +this visual structure to match exactly +what's going on but it's actually really + + align:start position:0% +what's going on but it's actually really + + + align:start position:0% +what's going on but it's actually really +useful in Python it that's what I like + + align:start position:0% +useful in Python it that's what I like + + + align:start position:0% +useful in Python it that's what I like +about python it's just helps you see + + align:start position:0% +about python it's just helps you see + + + align:start position:0% +about python it's just helps you see +things that are going on immediately + + align:start position:0% +things that are going on immediately + + + align:start position:0% +things that are going on immediately +like you know this this set of code is + + align:start position:0% +like you know this this set of code is + + + align:start position:0% +like you know this this set of code is +part of this code block and so it it + + align:start position:0% +part of this code block and so it it + + + align:start position:0% +part of this code block and so it it +helps you kind of debug a little bit + + align:start position:0% +helps you kind of debug a little bit + + + align:start position:0% +helps you kind of debug a little bit +more efficiently but the more practice + + align:start position:0% +more efficiently but the more practice + + + align:start position:0% +more efficiently but the more practice +you get the more you'll get used to kind + + align:start position:0% +you get the more you'll get used to kind + + + align:start position:0% +you get the more you'll get used to kind +of tracing the code and knowing exactly + + align:start position:0% +of tracing the code and knowing exactly + + + align:start position:0% +of tracing the code and knowing exactly +you know if these variables have this + + align:start position:0% +you know if these variables have this + + + align:start position:0% +you know if these variables have this +value exactly where your code is going + + align:start position:0% +value exactly where your code is going + + + align:start position:0% +value exactly where your code is going +to go so I'm going to skip this you triy + + align:start position:0% +to go so I'm going to skip this you triy + + + align:start position:0% +to go so I'm going to skip this you triy +it because it's just kind of you tra ing + + align:start position:0% +it because it's just kind of you tra ing + + + align:start position:0% +it because it's just kind of you tra ing +the code and I'm going to uh have you do + + align:start position:0% +the code and I'm going to uh have you do + + + align:start position:0% +the code and I'm going to uh have you do +this one or we can write it real quick + + align:start position:0% +this one or we can write it real quick + + + align:start position:0% +this one or we can write it real quick +or you can start and then we can write + + align:start position:0% +or you can start and then we can write + + + align:start position:0% +or you can start and then we can write +it together it's a variation of the + + align:start position:0% +it together it's a variation of the + + + align:start position:0% +it together it's a variation of the +program you just wrote instead of + + align:start position:0% +program you just wrote instead of + + + align:start position:0% +program you just wrote instead of +telling me whether the guess is true or + + align:start position:0% +telling me whether the guess is true or + + + align:start position:0% +telling me whether the guess is true or +F is the same as the secret number I + + align:start position:0% +F is the same as the secret number I + + + align:start position:0% +F is the same as the secret number I +just want you to print whether the guest + + align:start position:0% +just want you to print whether the guest + + + align:start position:0% +just want you to print whether the guest +is too low too high or the same as the + + align:start position:0% +is too low too high or the same as the + + + align:start position:0% +is too low too high or the same as the +secret number okay so we're going to + + align:start position:0% +secret number okay so we're going to + + + align:start position:0% +secret number okay so we're going to +need to put a conditional in there if + + align:start position:0% +need to put a conditional in there if + + + align:start position:0% +need to put a conditional in there if +some conditional you know we're going to + + align:start position:0% +some conditional you know we're going to + + + align:start position:0% +some conditional you know we're going to +print something and yeah so I'll give + + align:start position:0% +print something and yeah so I'll give + + + align:start position:0% +print something and yeah so I'll give +you about a minute and then we can write + + align:start position:0% +you about a minute and then we can write + + + align:start position:0% +you about a minute and then we can write +it together and then we can be + + align:start position:0% +it together and then we can be + + + align:start position:0% +it together and then we can be +done oh yeah have do if statements in + + align:start position:0% +done oh yeah have do if statements in + + + align:start position:0% +done oh yeah have do if statements in +the programs you can have two if + + align:start position:0% +the programs you can have two if + + + align:start position:0% +the programs you can have two if +statements in the program yeah and + + align:start position:0% +statements in the program yeah and + + + align:start position:0% +statements in the program yeah and +there's actually some exercises I have + + align:start position:0% +there's actually some exercises I have + + + align:start position:0% +there's actually some exercises I have +for you guys to try at home here where + + align:start position:0% +for you guys to try at home here where + + + align:start position:0% +for you guys to try at home here where +there are two if statements in the + + align:start position:0% +there are two if statements in the + + + align:start position:0% +there are two if statements in the +program and just to see what happens + + align:start position:0% +program and just to see what happens + + + align:start position:0% +program and just to see what happens +that starts two conditionals so if you + + align:start position:0% +that starts two conditionals so if you + + + align:start position:0% +that starts two conditionals so if you +have if some conditional that one can be + + align:start position:0% +have if some conditional that one can be + + + align:start position:0% +have if some conditional that one can be +true and if some other conditional that + + align:start position:0% +true and if some other conditional that + + + align:start position:0% +true and if some other conditional that +one can also be true and then both will + + align:start position:0% +one can also be true and then both will + + + align:start position:0% +one can also be true and then both will +be evaluated it's not an lse situation + + align:start position:0% +be evaluated it's not an lse situation + + + align:start position:0% +be evaluated it's not an lse situation +right yeah that's a good + + align:start position:0% + + + + align:start position:0% + +question so I'm just going to copy the + + align:start position:0% +question so I'm just going to copy the + + + align:start position:0% +question so I'm just going to copy the +in input from + + align:start position:0% +in input from + + + align:start position:0% +in input from +before does anyone have a start to my + + align:start position:0% +before does anyone have a start to my + + + align:start position:0% +before does anyone have a start to my +conditional I just copied what we had + + align:start position:0% +conditional I just copied what we had + + + align:start position:0% +conditional I just copied what we had +before for the + + align:start position:0% + + + + align:start position:0% + +input yeah so + + align:start position:0% + + + + align:start position:0% + +if text + + align:start position:0% + + + + align:start position:0% + +is + + align:start position:0% +is + + + align:start position:0% +is +yep + + align:start position:0% + + + + align:start position:0% + +yep + + align:start position:0% +yep + + + align:start position:0% +yep +print yep ju High + + align:start position:0% +print yep ju High + + + align:start position:0% +print yep ju High +good yep that's a great start so we can + + align:start position:0% +good yep that's a great start so we can + + + align:start position:0% +good yep that's a great start so we can +even run it and you know guess something + + align:start position:0% +even run it and you know guess something + + + align:start position:0% +even run it and you know guess something +that's we know is too high perfect too + + align:start position:0% +that's we know is too high perfect too + + + align:start position:0% +that's we know is too high perfect too +high yep + + align:start position:0% + + + + align:start position:0% + +next do you want to do an else or an L + + align:start position:0% +next do you want to do an else or an L + + + align:start position:0% +next do you want to do an else or an L +if yeah actually I would get rid of the + + align:start position:0% +if yeah actually I would get rid of the + + + align:start position:0% +if yeah actually I would get rid of the +uh equal sign because if we put in a + + align:start position:0% +uh equal sign because if we put in a + + + align:start position:0% +uh equal sign because if we put in a +five now it would still say too high + + align:start position:0% +five now it would still say too high + + + align:start position:0% +five now it would still say too high +that's a good point so if we run it now + + align:start position:0% +that's a good point so if we run it now + + + align:start position:0% +that's a good point so if we run it now +let's run it with a + + align:start position:0% +let's run it with a + + + align:start position:0% +let's run it with a +five it says too high exactly yeah so + + align:start position:0% +five it says too high exactly yeah so + + + align:start position:0% +five it says too high exactly yeah so +let's remove the equal sign it's a good + + align:start position:0% +let's remove the equal sign it's a good + + + align:start position:0% +let's remove the equal sign it's a good +thing we debugged that + + align:start position:0% +thing we debugged that + + + align:start position:0% +thing we debugged that +um so we can do an L if the guess is + + align:start position:0% +um so we can do an L if the guess is + + + align:start position:0% +um so we can do an L if the guess is +equivalent to the + + align:start position:0% +equivalent to the + + + align:start position:0% +equivalent to the +secret and then we can + + align:start position:0% +secret and then we can + + + align:start position:0% +secret and then we can +print uh equal right + + align:start position:0% + + + + align:start position:0% + +oops does everyone understand why we + + align:start position:0% +oops does everyone understand why we + + + align:start position:0% +oops does everyone understand why we +remove that equal sign from the greater + + align:start position:0% +remove that equal sign from the greater + + + align:start position:0% +remove that equal sign from the greater +than yeah because we would have Mist + + align:start position:0% +than yeah because we would have Mist + + + align:start position:0% +than yeah because we would have Mist +yeah we would have mistakenly gone into + + align:start position:0% +yeah we would have mistakenly gone into + + + align:start position:0% +yeah we would have mistakenly gone into +that first path but L if we can have a + + align:start position:0% +that first path but L if we can have a + + + align:start position:0% +that first path but L if we can have a +case where the guess is equivalent to + + align:start position:0% +case where the guess is equivalent to + + + align:start position:0% +case where the guess is equivalent to +secret sure and then we'll print equal + + align:start position:0% +secret sure and then we'll print equal + + + align:start position:0% +secret sure and then we'll print equal +and then the last one can either be an + + align:start position:0% +and then the last one can either be an + + + align:start position:0% +and then the last one can either be an +else because we know the only other + + align:start position:0% +else because we know the only other + + + align:start position:0% +else because we know the only other +option is guess is less than or we can + + align:start position:0% +option is guess is less than or we can + + + align:start position:0% +option is guess is less than or we can +do another LF if we want to but we can + + align:start position:0% +do another LF if we want to but we can + + + align:start position:0% +do another LF if we want to but we can +leave it as an else and then we can + + align:start position:0% +leave it as an else and then we can + + + align:start position:0% +leave it as an else and then we can +print um to + + align:start position:0% + + + + align:start position:0% + +low and then we can run it and we can + + align:start position:0% +low and then we can run it and we can + + + align:start position:0% +low and then we can run it and we can +guess all the variations so something + + align:start position:0% +guess all the variations so something + + + align:start position:0% +guess all the variations so something +that's too high something that's the + + align:start position:0% +that's too high something that's the + + + align:start position:0% +that's too high something that's the +same + + align:start position:0% + + + + align:start position:0% + +and I'm not sure what I did + + align:start position:0% +and I'm not sure what I did + + + align:start position:0% +and I'm not sure what I did +there I should restart my + + align:start position:0% + + + + align:start position:0% + +Cal so we did something that's too high + + align:start position:0% +Cal so we did something that's too high + + + align:start position:0% +Cal so we did something that's too high +something that + + align:start position:0% + + + + align:start position:0% + +is uh equivalent and then we can do + + align:start position:0% +is uh equivalent and then we can do + + + align:start position:0% +is uh equivalent and then we can do +something that's too low + + align:start position:0% +something that's too low + + + align:start position:0% +something that's too low +okay yeah what's the difference between + + align:start position:0% +okay yeah what's the difference between + + + align:start position:0% +okay yeah what's the difference between +having El and El as a so there is no + + align:start position:0% +having El and El as a so there is no + + + align:start position:0% +having El and El as a so there is no +difference we can do an L if guess is + + align:start position:0% +difference we can do an L if guess is + + + align:start position:0% +difference we can do an L if guess is +less than secret that would the the + + align:start position:0% +less than secret that would the the + + + align:start position:0% +less than secret that would the the +program would work just the same the + + align:start position:0% +program would work just the same the + + + align:start position:0% +program would work just the same the +else is just quicker because we know + + align:start position:0% +else is just quicker because we know + + + align:start position:0% +else is just quicker because we know +there are no other options uh here why + + align:start position:0% +there are no other options uh here why + + + align:start position:0% +there are no other options uh here why +would + + align:start position:0% +would + + + align:start position:0% +would +a we could also in this particular case + + align:start position:0% +a we could also in this particular case + + + align:start position:0% +a we could also in this particular case +we could also put a bunch of if + + align:start position:0% +we could also put a bunch of if + + + align:start position:0% +we could also put a bunch of if +statements in a row but then we'd have + + align:start position:0% +statements in a row but then we'd have + + + align:start position:0% +statements in a row but then we'd have +to be careful that they are mutually + + align:start position:0% +to be careful that they are mutually + + + align:start position:0% +to be careful that they are mutually +exclusive so like in the pre in the + + align:start position:0% +exclusive so like in the pre in the + + + align:start position:0% +exclusive so like in the pre in the +previous example right if we have a + + align:start position:0% +previous example right if we have a + + + align:start position:0% +previous example right if we have a +bunch of conditions that might all all + + align:start position:0% +bunch of conditions that might all all + + + align:start position:0% +bunch of conditions that might all all +be true all those ifs will + + align:start position:0% +be true all those ifs will + + + align:start position:0% +be true all those ifs will +execute right that's the thing because + + align:start position:0% +execute right that's the thing because + + + align:start position:0% +execute right that's the thing because +the if starts a block the L if is just + + align:start position:0% +the if starts a block the L if is just + + + align:start position:0% +the if starts a block the L if is just +associated with that block so either you + + align:start position:0% +associated with that block so either you + + + align:start position:0% +associated with that block so either you +do one or the other or the other but if + + align:start position:0% +do one or the other or the other but if + + + align:start position:0% +do one or the other or the other but if +you have a whole bunch of ifs then they + + align:start position:0% +you have a whole bunch of ifs then they + + + align:start position:0% +you have a whole bunch of ifs then they +might all be true and they'll all be + + align:start position:0% +might all be true and they'll all be + + + align:start position:0% +might all be true and they'll all be +executed + + align:start position:0% +executed + + + align:start position:0% +executed +yeah yeah why don't we use parentheses + + align:start position:0% +yeah yeah why don't we use parentheses + + + align:start position:0% +yeah yeah why don't we use parentheses +with an oh we could use parentheses in + + align:start position:0% +with an oh we could use parentheses in + + + align:start position:0% +with an oh we could use parentheses in +the if El statements you mean like this + + align:start position:0% +the if El statements you mean like this + + + align:start position:0% +the if El statements you mean like this +yeah we can do that especially if we + + align:start position:0% +yeah we can do that especially if we + + + align:start position:0% +yeah we can do that especially if we +have a whole bunch of Expressions + + align:start position:0% +have a whole bunch of Expressions + + + align:start position:0% +have a whole bunch of Expressions +together but if there's just one python + + align:start position:0% +together but if there's just one python + + + align:start position:0% +together but if there's just one python +will automatically know to do the + + align:start position:0% +will automatically know to do the + + + align:start position:0% +will automatically know to do the +expression first and then do the if yeah + + align:start position:0% +expression first and then do the if yeah + + + align:start position:0% +expression first and then do the if yeah +these are all wonderful questions by the + + align:start position:0% +these are all wonderful questions by the + + + align:start position:0% +these are all wonderful questions by the +way + + align:start position:0% +way + + + align:start position:0% +way +okay so um as we saw there was a little + + align:start position:0% +okay so um as we saw there was a little + + + align:start position:0% +okay so um as we saw there was a little +bug in our code it's a good thing we ran + + align:start position:0% +bug in our code it's a good thing we ran + + + align:start position:0% +bug in our code it's a good thing we ran +it I should have run it with a bunch of + + align:start position:0% +it I should have run it with a bunch of + + + align:start position:0% +it I should have run it with a bunch of +different options but it's important to + + align:start position:0% +different options but it's important to + + + align:start position:0% +different options but it's important to +debug early and debug often just to make + + align:start position:0% +debug early and debug often just to make + + + align:start position:0% +debug early and debug often just to make +sure that you don't introduce a bug that + + align:start position:0% +sure that you don't introduce a bug that + + + align:start position:0% +sure that you don't introduce a bug that +will kind of carry on throughout the + + align:start position:0% +will kind of carry on throughout the + + + align:start position:0% +will kind of carry on throughout the +code um that's another big idea and then + + align:start position:0% +code um that's another big idea and then + + + align:start position:0% +code um that's another big idea and then +a quick summary of what we've learned + + align:start position:0% +a quick summary of what we've learned + + + align:start position:0% +a quick summary of what we've learned +input and outputs obviously make our + + align:start position:0% +input and outputs obviously make our + + + align:start position:0% +input and outputs obviously make our +programs interactive we uh added + + align:start position:0% +programs interactive we uh added + + + align:start position:0% +programs interactive we uh added +branching as a way to introduce decision + + align:start position:0% +branching as a way to introduce decision + + + align:start position:0% +branching as a way to introduce decision +points in our program and next time + + align:start position:0% +points in our program and next time + + + align:start position:0% +points in our program and next time +we're going to do a little bit more + + align:start position:0% +we're going to do a little bit more + + + align:start position:0% +we're going to do a little bit more +branching and then introduce looping so + + align:start position:0% +branching and then introduce looping so + + + align:start position:0% +branching and then introduce looping so +ways to repeat uh commands in our + + align:start position:0% +ways to repeat uh commands in our + + + align:start position:0% +ways to repeat uh commands in our +programs sorry I went a little bit over + + align:start position:0% +programs sorry I went a little bit over + + + align:start position:0% +programs sorry I went a little bit over +time uh I won't do that again \ No newline at end of file diff --git a/Ug6DYV6za-k.txt b/Ug6DYV6za-k.txt new file mode 100644 index 0000000000000000000000000000000000000000..3c812b0aa72d0ed6a6f898875ff1060de81e39cb --- /dev/null +++ b/Ug6DYV6za-k.txt @@ -0,0 +1,387 @@ +align:start position:0% + +first problem is right here uh I'm going + + align:start position:0% +first problem is right here uh I'm going + + + align:start position:0% +first problem is right here uh I'm going +to give you a chance to practice doing a + + align:start position:0% +to give you a chance to practice doing a + + + align:start position:0% +to give you a chance to practice doing a +proportional derivative + + align:start position:0% +proportional derivative + + + align:start position:0% +proportional derivative +controller and I've actually written the + + align:start position:0% +controller and I've actually written the + + + align:start position:0% +controller and I've actually written the +specifications directly in terms of + + align:start position:0% +specifications directly in terms of + + + align:start position:0% +specifications directly in terms of +phase margin and crossover frequency + + align:start position:0% +phase margin and crossover frequency + + + align:start position:0% +phase margin and crossover frequency +so you can either imagine that that's + + align:start position:0% +so you can either imagine that that's + + + align:start position:0% +so you can either imagine that that's +the way the the specifications are given + + align:start position:0% +the way the the specifications are given + + + align:start position:0% +the way the the specifications are given +or that we started with a rise time uh + + align:start position:0% +or that we started with a rise time uh + + + align:start position:0% +or that we started with a rise time uh +and Peak overshoot and and derive these + + align:start position:0% +and Peak overshoot and and derive these + + + align:start position:0% +and Peak overshoot and and derive these +so your goal is to design a kfs that + + align:start position:0% +so your goal is to design a kfs that + + + align:start position:0% +so your goal is to design a kfs that +meets these um specifications so if + + align:start position:0% +meets these um specifications so if + + + align:start position:0% +meets these um specifications so if +everyone could please uh form up in + + align:start position:0% +everyone could please uh form up in + + + align:start position:0% +everyone could please uh form up in +groups of two around the room as usual + + align:start position:0% +groups of two around the room as usual + + + align:start position:0% +groups of two around the room as usual +I'm Steve Hall I'm the instructor of + + align:start position:0% +I'm Steve Hall I'm the instructor of + + + align:start position:0% +I'm Steve Hall I'm the instructor of +16006 which is principles of automatic + + align:start position:0% +16006 which is principles of automatic + + + align:start position:0% +16006 which is principles of automatic +control uh it's a junior level + + align:start position:0% +control uh it's a junior level + + + align:start position:0% +control uh it's a junior level +uh classical control class which I've + + align:start position:0% +uh classical control class which I've + + + align:start position:0% +uh classical control class which I've +been teaching for about six years so + + align:start position:0% +been teaching for about six years so + + + align:start position:0% +been teaching for about six years so +recitations in 16006 are a little + + align:start position:0% +recitations in 16006 are a little + + + align:start position:0% +recitations in 16006 are a little +different than most recitations at MIT + + align:start position:0% +different than most recitations at MIT + + + align:start position:0% +different than most recitations at MIT +it in in most recitations uh the + + align:start position:0% +it in in most recitations uh the + + + align:start position:0% +it in in most recitations uh the +instructor would uh present a series of + + align:start position:0% +instructor would uh present a series of + + + align:start position:0% +instructor would uh present a series of +problems uh maybe related to the + + align:start position:0% +problems uh maybe related to the + + + align:start position:0% +problems uh maybe related to the +homework uh just to give examples of how + + align:start position:0% +homework uh just to give examples of how + + + align:start position:0% +homework uh just to give examples of how +uh the problem should be worked uh + + align:start position:0% +uh the problem should be worked uh + + + align:start position:0% +uh the problem should be worked uh +sometimes they might have students uh + + align:start position:0% +sometimes they might have students uh + + + align:start position:0% +sometimes they might have students uh +try some themselves uh in my recitations + + align:start position:0% +try some themselves uh in my recitations + + + align:start position:0% +try some themselves uh in my recitations +it's much more active students are are + + align:start position:0% +it's much more active students are are + + + align:start position:0% +it's much more active students are are +um always standing up uh we work at the + + align:start position:0% +um always standing up uh we work at the + + + align:start position:0% +um always standing up uh we work at the +board uh usually in in groups of two so + + align:start position:0% +board uh usually in in groups of two so + + + align:start position:0% +board uh usually in in groups of two so +uh there might be 10 groups of two + + align:start position:0% +uh there might be 10 groups of two + + + align:start position:0% +uh there might be 10 groups of two +spread around the room uh each group of + + align:start position:0% +spread around the room uh each group of + + + align:start position:0% +spread around the room uh each group of +two working at a board uh a Blackboard a + + align:start position:0% +two working at a board uh a Blackboard a + + + align:start position:0% +two working at a board uh a Blackboard a +whiteboard could be a a a poster board + + align:start position:0% +whiteboard could be a a a poster board + + + align:start position:0% +whiteboard could be a a a poster board +uh they're working + + align:start position:0% +uh they're working + + + align:start position:0% +uh they're working +problems uh and the TA and I are walking + + align:start position:0% +problems uh and the TA and I are walking + + + align:start position:0% +problems uh and the TA and I are walking +around and um helping when we can + + align:start position:0% +around and um helping when we can + + + align:start position:0% +around and um helping when we can +answering questions when uh students + + align:start position:0% +answering questions when uh students + + + align:start position:0% +answering questions when uh students +have them uh in generally just coaching + + align:start position:0% +have them uh in generally just coaching + + + align:start position:0% +have them uh in generally just coaching +trying to help the students uh + + align:start position:0% +trying to help the students uh + + + align:start position:0% +trying to help the students uh +understand what they're doing and solve + + align:start position:0% +understand what they're doing and solve + + + align:start position:0% +understand what they're doing and solve +the problems really is a chance for + + align:start position:0% +the problems really is a chance for + + + align:start position:0% +the problems really is a chance for +students to understand uh what they know + + align:start position:0% +students to understand uh what they know + + + align:start position:0% +students to understand uh what they know +and what they don't know and to exercise + + align:start position:0% +and what they don't know and to exercise + + + align:start position:0% +and what they don't know and to exercise +the skills that they've learned in the + + align:start position:0% +the skills that they've learned in the + + + align:start position:0% +the skills that they've learned in the +class uh and if they have problems with + + align:start position:0% +class uh and if they have problems with + + + align:start position:0% +class uh and if they have problems with +those skills it's a chance for me to + + align:start position:0% +those skills it's a chance for me to + + + align:start position:0% +those skills it's a chance for me to +help them uh learn them better \ No newline at end of file diff --git a/WK5o1nGwTdU.txt b/WK5o1nGwTdU.txt new file mode 100644 index 0000000000000000000000000000000000000000..c38b7aaeb14beb6e251c95bf2c1a4601551a5116 --- /dev/null +++ b/WK5o1nGwTdU.txt @@ -0,0 +1,155 @@ +align:start position:0% + +My name is Luis Perez Breva and I teach + + align:start position:0% +My name is Luis Perez Breva and I teach + + + align:start position:0% +My name is Luis Perez Breva and I teach +the MIT class on how to move + + align:start position:0% +the MIT class on how to move + + + align:start position:0% +the MIT class on how to move +technologies from lab to impact. It is + + align:start position:0% +technologies from lab to impact. It is + + + align:start position:0% +technologies from lab to impact. It is +called innovation teams and it's the + + align:start position:0% +called innovation teams and it's the + + + align:start position:0% +called innovation teams and it's the +longest running course at MIT in + + align:start position:0% +longest running course at MIT in + + + align:start position:0% +longest running course at MIT in +technology innovation. In it, students + + align:start position:0% +technology innovation. In it, students + + + align:start position:0% +technology innovation. In it, students +learn to solve problems with technology. + + align:start position:0% +learn to solve problems with technology. + + + align:start position:0% +learn to solve problems with technology. +This series of videos is an introduction + + align:start position:0% +This series of videos is an introduction + + + align:start position:0% +This series of videos is an introduction +to a whole new mindset for innovation. + + align:start position:0% +to a whole new mindset for innovation. + + + align:start position:0% +to a whole new mindset for innovation. +We can help you think the way the most + + align:start position:0% +We can help you think the way the most + + + align:start position:0% +We can help you think the way the most +creative engineers do. There's 40 years + + align:start position:0% +creative engineers do. There's 40 years + + + align:start position:0% +creative engineers do. There's 40 years +worth of technology sitting and awaiting + + align:start position:0% +worth of technology sitting and awaiting + + + align:start position:0% +worth of technology sitting and awaiting +for individuals with a new kind of + + align:start position:0% +for individuals with a new kind of + + + align:start position:0% +for individuals with a new kind of +problem solving skill. I will share with + + align:start position:0% +problem solving skill. I will share with + + + align:start position:0% +problem solving skill. I will share with +you the MIT way to solve problems with + + align:start position:0% +you the MIT way to solve problems with + + + align:start position:0% +you the MIT way to solve problems with +technology. Many of the ideas I will + + align:start position:0% +technology. Many of the ideas I will + + + align:start position:0% +technology. Many of the ideas I will +share with you in these videos and more + + align:start position:0% +share with you in these videos and more + + + align:start position:0% +share with you in these videos and more +can be found in my book, Innovating AR's + + align:start position:0% +can be found in my book, Innovating AR's + + + align:start position:0% +can be found in my book, Innovating AR's +Manifesto. + + align:start position:0% + + + + align:start position:0% + +[Music] \ No newline at end of file diff --git a/XMVoIzP6Kpo.txt b/XMVoIzP6Kpo.txt new file mode 100644 index 0000000000000000000000000000000000000000..f6b6a222a62bd6c38ea3c0e7910669bf4e8515b6 --- /dev/null +++ b/XMVoIzP6Kpo.txt @@ -0,0 +1,14523 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit MIT opencourseware + + align:start position:0% +of MIT courses visit MIT opencourseware + + + align:start position:0% +of MIT courses visit MIT opencourseware +at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu let's March ahead into + + align:start position:0% +ocw.mit.edu let's March ahead into + + + align:start position:0% +ocw.mit.edu let's March ahead into +Upstate New York and do for Malahide + + align:start position:0% +Upstate New York and do for Malahide + + + align:start position:0% +Upstate New York and do for Malahide +but + + align:start position:0% +but + + + align:start position:0% +but +first there's a what should business do + + align:start position:0% +first there's a what should business do + + + align:start position:0% +first there's a what should business do +issue that I should have brought up last + + align:start position:0% +issue that I should have brought up last + + + align:start position:0% +issue that I should have brought up last +time so I'll bring it up now because I + + align:start position:0% +time so I'll bring it up now because I + + + align:start position:0% +time so I'll bring it up now because I +didn't this is super + + align:start position:0% +didn't this is super + + + align:start position:0% +didn't this is super +Pacs how many people know what the + + align:start position:0% +Pacs how many people know what the + + + align:start position:0% +Pacs how many people know what the +citizens united decision is or + + align:start position:0% + + + + align:start position:0% + +was so well it's more than that yep a + + align:start position:0% +was so well it's more than that yep a + + + align:start position:0% +was so well it's more than that yep a +few let me just walk through it a little + + align:start position:0% +few let me just walk through it a little + + + align:start position:0% +few let me just walk through it a little +bit so before + + align:start position:0% +bit so before + + + align:start position:0% +bit so before +2010 basically corporations and unions + + align:start position:0% +2010 basically corporations and unions + + + align:start position:0% +2010 basically corporations and unions +well they still can't make direct + + align:start position:0% +well they still can't make direct + + + align:start position:0% +well they still can't make direct +contributions to + + align:start position:0% +contributions to + + + align:start position:0% +contributions to +candidates um they could fund + + align:start position:0% +candidates um they could fund + + + align:start position:0% +candidates um they could fund +independent organizations that put up + + align:start position:0% +independent organizations that put up + + + align:start position:0% +independent organizations that put up +political ads but the political ads + + align:start position:0% +political ads but the political ads + + + align:start position:0% +political ads but the political ads +couldn't be near + + align:start position:0% +couldn't be near + + + align:start position:0% +couldn't be near +elections etc etc now after this + + align:start position:0% +elections etc etc now after this + + + align:start position:0% +elections etc etc now after this +decision they can do essentially + + align:start position:0% +decision they can do essentially + + + align:start position:0% +decision they can do essentially +anything as long as it's not formally + + align:start position:0% +anything as long as it's not formally + + + align:start position:0% +anything as long as it's not formally +part of a + + align:start position:0% +part of a + + + align:start position:0% +part of a +campaign so if you've been + + align:start position:0% +campaign so if you've been + + + align:start position:0% +campaign so if you've been +following this year's Republican primary + + align:start position:0% +following this year's Republican primary + + + align:start position:0% +following this year's Republican primary +season there a lot of super pack ads + + align:start position:0% +season there a lot of super pack ads + + + align:start position:0% +season there a lot of super pack ads +targeting one candidate or another most + + align:start position:0% +targeting one candidate or another most + + + align:start position:0% +targeting one candidate or another most +of it's negative and there's a lot of + + align:start position:0% +of it's negative and there's a lot of + + + align:start position:0% +of it's negative and there's a lot of +money the question is you're the head of + + align:start position:0% +money the question is you're the head of + + + align:start position:0% +money the question is you're the head of +a publicly traded Corporation you can + + align:start position:0% +a publicly traded Corporation you can + + + align:start position:0% +a publicly traded Corporation you can +now make major political + + align:start position:0% +now make major political + + + align:start position:0% +now make major political +contributions the corporation can now + + align:start position:0% +contributions the corporation can now + + + align:start position:0% +contributions the corporation can now +make major + + align:start position:0% +make major + + + align:start position:0% +make major +political contributions should + + align:start position:0% +political contributions should + + + align:start position:0% +political contributions should +you should you or when should + + align:start position:0% +you should you or when should + + + align:start position:0% +you should you or when should +you Stephen what do you + + align:start position:0% +you Stephen what do you + + + align:start position:0% +you Stephen what do you +think um I think they should be able to + + align:start position:0% +think um I think they should be able to + + + align:start position:0% +think um I think they should be able to +able to I'm not talking about that + + align:start position:0% +able to I'm not talking about that + + + align:start position:0% +able to I'm not talking about that +should they you're the you're the CEO of + + align:start position:0% +should they you're the you're the CEO of + + + align:start position:0% +should they you're the you're the CEO of +oh pick your fa you're the CEO of + + align:start position:0% +oh pick your fa you're the CEO of + + + align:start position:0% +oh pick your fa you're the CEO of +Apple should you and Apple's got a lot + + align:start position:0% +Apple should you and Apple's got a lot + + + align:start position:0% +Apple should you and Apple's got a lot +of cash should you spend some of it uh + + align:start position:0% +of cash should you spend some of it uh + + + align:start position:0% +of cash should you spend some of it uh +to give some of it to a Super PAC which + + align:start position:0% +to give some of it to a Super PAC which + + + align:start position:0% +to give some of it to a Super PAC which +has a political + + align:start position:0% +has a political + + + align:start position:0% +has a political +agenda that you know that's all um at + + align:start position:0% +agenda that you know that's all um at + + + align:start position:0% +agenda that you know that's all um at +the end of the day I think there is no + + align:start position:0% +the end of the day I think there is no + + + align:start position:0% +the end of the day I think there is no +harm in doing so so I would recommend or + + align:start position:0% +harm in doing so so I would recommend or + + + align:start position:0% +harm in doing so so I would recommend or +I would eventally do that just because + + align:start position:0% +I would eventally do that just because + + + align:start position:0% +I would eventally do that just because +um when you have all these different + + align:start position:0% +um when you have all these different + + + align:start position:0% +um when you have all these different +candidates that could potentially move + + align:start position:0% +candidates that could potentially move + + + align:start position:0% +candidates that could potentially move +things in different directions + + align:start position:0% +things in different directions + + + align:start position:0% +things in different directions +especially for a company that like apple + + align:start position:0% +especially for a company that like apple + + + align:start position:0% +especially for a company that like apple +that relies heavily on foreign countries + + align:start position:0% +that relies heavily on foreign countries + + + align:start position:0% +that relies heavily on foreign countries +to do some of their manufacturing or + + align:start position:0% +to do some of their manufacturing or + + + align:start position:0% +to do some of their manufacturing or +some of their new products coming out + + align:start position:0% +some of their new products coming out + + + align:start position:0% +some of their new products coming out +and other related patents it could be + + align:start position:0% +and other related patents it could be + + + align:start position:0% +and other related patents it could be +very favorable for them to see a certain + + align:start position:0% +very favorable for them to see a certain + + + align:start position:0% +very favorable for them to see a certain +type of political candidate in office + + align:start position:0% +type of political candidate in office + + + align:start position:0% +type of political candidate in office +rather than someone else so you would do + + align:start position:0% +rather than someone else so you would do + + + align:start position:0% +rather than someone else so you would do +it where the corporations interests were + + align:start position:0% +it where the corporations interests were + + + align:start position:0% +it where the corporations interests were +direct likely to be directly affected + + align:start position:0% +direct likely to be directly affected + + + align:start position:0% +direct likely to be directly affected +yes any any other reason you might Do It + + align:start position:0% +yes any any other reason you might Do It + + + align:start position:0% +yes any any other reason you might Do It +um I would also do it as could also do + + align:start position:0% +um I would also do it as could also do + + + align:start position:0% +um I would also do it as could also do +it more of a publicity type of thing + + align:start position:0% +it more of a publicity type of thing + + + align:start position:0% +it more of a publicity type of thing +where it's saying that um we're in favor + + align:start position:0% +where it's saying that um we're in favor + + + align:start position:0% +where it's saying that um we're in favor +of this screen energy initiative and we + + align:start position:0% +of this screen energy initiative and we + + + align:start position:0% +of this screen energy initiative and we +would like to see um our candidates + + align:start position:0% +would like to see um our candidates + + + align:start position:0% +would like to see um our candidates +supported in that + + align:start position:0% +supported in that + + + align:start position:0% +supported in that +area okay David you with him um yeah I + + align:start position:0% +area okay David you with him um yeah I + + + align:start position:0% +area okay David you with him um yeah I +agree that um I mean the the overall + + align:start position:0% +agree that um I mean the the overall + + + align:start position:0% +agree that um I mean the the overall +like morality dist as a CEO I would + + align:start position:0% +like morality dist as a CEO I would + + + align:start position:0% +like morality dist as a CEO I would +probably um donate some money if there + + align:start position:0% +probably um donate some money if there + + + align:start position:0% +probably um donate some money if there +was a direct impact so again from a PR + + align:start position:0% +was a direct impact so again from a PR + + + align:start position:0% +was a direct impact so again from a PR +whatever I'm trying to accomplish as far + + align:start position:0% +whatever I'm trying to accomplish as far + + + align:start position:0% +whatever I'm trying to accomplish as far +as the company know I think Apple gave + + align:start position:0% +as the company know I think Apple gave + + + align:start position:0% +as the company know I think Apple gave +money to a political action campaign + + align:start position:0% +money to a political action campaign + + + align:start position:0% +money to a political action campaign +opposing the gay marriage m in + + align:start position:0% +opposing the gay marriage m in + + + align:start position:0% +opposing the gay marriage m in +California so that's you know part of + + align:start position:0% +California so that's you know part of + + + align:start position:0% +California so that's you know part of +the image that they push forward I think + + align:start position:0% +the image that they push forward I think + + + align:start position:0% +the image that they push forward I think +that might have been Apple's Regular + + align:start position:0% +that might have been Apple's Regular + + + align:start position:0% +that might have been Apple's Regular +Pack I don't think it was a super Maybe + + align:start position:0% +Pack I don't think it was a super Maybe + + + align:start position:0% +Pack I don't think it was a super Maybe +I'm Wrong I think it was the regular the + + align:start position:0% +I'm Wrong I think it was the regular the + + + align:start position:0% +I'm Wrong I think it was the regular the +regular packs let me describe it they've + + align:start position:0% +regular packs let me describe it they've + + + align:start position:0% +regular packs let me describe it they've +existed for a long time the regular + + align:start position:0% +existed for a long time the regular + + + align:start position:0% +existed for a long time the regular +packs where the executives of the + + align:start position:0% +packs where the executives of the + + + align:start position:0% +packs where the executives of the +company contribute money + + align:start position:0% +company contribute money + + + align:start position:0% +company contribute money +the Super PAC is where the company + + align:start position:0% +the Super PAC is where the company + + + align:start position:0% +the Super PAC is where the company +contributes money there's a big + + align:start position:0% +contributes money there's a big + + + align:start position:0% +contributes money there's a big +difference right one is one is the + + align:start position:0% +difference right one is one is the + + + align:start position:0% +difference right one is one is the +executives own money Executives or board + + align:start position:0% +executives own money Executives or board + + + align:start position:0% +executives own money Executives or board +members and the other is my money as a + + align:start position:0% +members and the other is my money as a + + + align:start position:0% +members and the other is my money as a +shareholder of + + align:start position:0% +shareholder of + + + align:start position:0% +shareholder of +Apple but if it directly affects the + + align:start position:0% +Apple but if it directly affects the + + + align:start position:0% +Apple but if it directly affects the +corporation I take the point but you do + + align:start position:0% +corporation I take the point but you do + + + align:start position:0% +corporation I take the point but you do +it for publicity and you do it for a + + align:start position:0% +it for publicity and you do it for a + + + align:start position:0% +it for publicity and you do it for a +variety of causes so I'm a right-wing + + align:start position:0% +variety of causes so I'm a right-wing + + + align:start position:0% +variety of causes so I'm a right-wing +Republican who owns Apple stock do I + + align:start position:0% +Republican who owns Apple stock do I + + + align:start position:0% +Republican who owns Apple stock do I +like you you giving to a green + + align:start position:0% +like you you giving to a green + + + align:start position:0% +like you you giving to a green +pack you don't care + + align:start position:0% +pack you don't care + + + align:start position:0% +pack you don't care +okay app shares the you know have + + align:start position:0% +okay app shares the you know have + + + align:start position:0% +okay app shares the you know have +distaste in the + + align:start position:0% + + + + align:start position:0% + +political okay stance that we're taking + + align:start position:0% +political okay stance that we're taking + + + align:start position:0% +political okay stance that we're taking +is really that offensive to you anybody + + align:start position:0% +is really that offensive to you anybody + + + align:start position:0% +is really that offensive to you anybody +from the other side of the room Vivian + + align:start position:0% +from the other side of the room Vivian + + + align:start position:0% +from the other side of the room Vivian +what do you think sorry i w a little B I + + align:start position:0% +what do you think sorry i w a little B I + + + align:start position:0% +what do you think sorry i w a little B I +don't really know where we're at the the + + align:start position:0% +don't really know where we're at the the + + + align:start position:0% +don't really know where we're at the the +question is uh should a corporation + + align:start position:0% +question is uh should a corporation + + + align:start position:0% +question is uh should a corporation +let's say take a big corporation that + + align:start position:0% +let's say take a big corporation that + + + align:start position:0% +let's say take a big corporation that +has cash make contributions not the + + align:start position:0% +has cash make contributions not the + + + align:start position:0% +has cash make contributions not the +executives but should the CEO cause the + + align:start position:0% +executives but should the CEO cause the + + + align:start position:0% +executives but should the CEO cause the +company to make political + + align:start position:0% +company to make political + + + align:start position:0% +company to make political +contributions and if so when and if not + + align:start position:0% +contributions and if so when and if not + + + align:start position:0% +contributions and if so when and if not +why + + align:start position:0% + + + + align:start position:0% + +not contri should I go for the reform + + align:start position:0% +not contri should I go for the reform + + + align:start position:0% +not contri should I go for the reform +America pack that favors Ron Paul or the + + align:start position:0% +America pack that favors Ron Paul or the + + + align:start position:0% +America pack that favors Ron Paul or the +I forget what it's called pack that + + align:start position:0% +I forget what it's called pack that + + + align:start position:0% +I forget what it's called pack that +favors Romney or one of the Obama + + align:start position:0% +favors Romney or one of the Obama + + + align:start position:0% +favors Romney or one of the Obama +leaning packs + + align:start position:0% +leaning packs + + + align:start position:0% +leaning packs +or I think that's a really risky + + align:start position:0% +or I think that's a really risky + + + align:start position:0% +or I think that's a really risky +decision to make as of like different + + align:start position:0% +decision to make as of like different + + + align:start position:0% +decision to make as of like different +interest of your + + align:start position:0% +interest of your + + + align:start position:0% +interest of your +shareholders so sh shareholders might + + align:start position:0% +shareholders so sh shareholders might + + + align:start position:0% +shareholders so sh shareholders might +not all agree right yeah FY you were in + + align:start position:0% +not all agree right yeah FY you were in + + + align:start position:0% +not all agree right yeah FY you were in +the interest of the company like in + + align:start position:0% +the interest of the company like in + + + align:start position:0% +the interest of the company like in +regards to like apple with exports from + + align:start position:0% +regards to like apple with exports from + + + align:start position:0% +regards to like apple with exports from +or imports from other countries in terms + + align:start position:0% +or imports from other countries in terms + + + align:start position:0% +or imports from other countries in terms +of manufacturing like it's in the + + align:start position:0% +of manufacturing like it's in the + + + align:start position:0% +of manufacturing like it's in the +benefit it's beneficial to the company + + align:start position:0% +benefit it's beneficial to the company + + + align:start position:0% +benefit it's beneficial to the company +and to the shareholders to maximize + + align:start position:0% +and to the shareholders to maximize + + + align:start position:0% +and to the shareholders to maximize +value in that way + + align:start position:0% +value in that way + + + align:start position:0% +value in that way +so I think I think it's favorable if + + align:start position:0% +so I think I think it's favorable if + + + align:start position:0% +so I think I think it's favorable if +they're doing it for the compan so if + + align:start position:0% +they're doing it for the compan so if + + + align:start position:0% +they're doing it for the compan so if +it's if it's somebody particularly + + align:start position:0% +it's if it's somebody particularly + + + align:start position:0% +it's if it's somebody particularly +focused on on them Ariana I agree um I + + align:start position:0% +focused on on them Ariana I agree um I + + + align:start position:0% +focused on on them Ariana I agree um I +think that like even if like uh the the + + align:start position:0% +think that like even if like uh the the + + + align:start position:0% +think that like even if like uh the the +company ends up giving money to a cause + + align:start position:0% +company ends up giving money to a cause + + + align:start position:0% +company ends up giving money to a cause +that you don't necessarily personally + + align:start position:0% +that you don't necessarily personally + + + align:start position:0% +that you don't necessarily personally +support like as a shareholder you like I + + align:start position:0% +support like as a shareholder you like I + + + align:start position:0% +support like as a shareholder you like I +think you should think of your interest + + align:start position:0% +think you should think of your interest + + + align:start position:0% +think you should think of your interest +separately so like you have interest in + + align:start position:0% +separately so like you have interest in + + + align:start position:0% +separately so like you have interest in +this uh corporation like as pertains to + + align:start position:0% +this uh corporation like as pertains to + + + align:start position:0% +this uh corporation like as pertains to +making a profit and you might also have + + align:start position:0% +making a profit and you might also have + + + align:start position:0% +making a profit and you might also have +separate person interest and so like if + + align:start position:0% +separate person interest and so like if + + + align:start position:0% +separate person interest and so like if +you personally you want to donate to + + align:start position:0% +you personally you want to donate to + + + align:start position:0% +you personally you want to donate to +like whoever you think has the right + + align:start position:0% +like whoever you think has the right + + + align:start position:0% +like whoever you think has the right +position on gay marriage I think that's + + align:start position:0% +position on gay marriage I think that's + + + align:start position:0% +position on gay marriage I think that's +that that's fine but you should know + + align:start position:0% +that that's fine but you should know + + + align:start position:0% +that that's fine but you should know +that the interest in the corporation is + + align:start position:0% +that the interest in the corporation is + + + align:start position:0% +that the interest in the corporation is +purely about making a profit so if the + + align:start position:0% +purely about making a profit so if the + + + align:start position:0% +purely about making a profit so if the +corporation is supporting um is + + align:start position:0% +corporation is supporting um is + + + align:start position:0% +corporation is supporting um is +supporting a cause that that furthers + + align:start position:0% +supporting a cause that that furthers + + + align:start position:0% +supporting a cause that that furthers +that goal then that's fine but gab + + align:start position:0% +that goal then that's fine but gab + + + align:start position:0% +that goal then that's fine but gab +marriage probably doesn't have a lot to + + align:start position:0% +marriage probably doesn't have a lot to + + + align:start position:0% +marriage probably doesn't have a lot to +do with my my earnings as a shareholder + + align:start position:0% +do with my my earnings as a shareholder + + + align:start position:0% +do with my my earnings as a shareholder +you you shouldn't be worried about the + + align:start position:0% +you you shouldn't be worried about the + + + align:start position:0% +you you shouldn't be worried about the +corporation getting involved in that + + align:start position:0% + + + + align:start position:0% + +Andrew so uh one thing about like this + + align:start position:0% +Andrew so uh one thing about like this + + + align:start position:0% +Andrew so uh one thing about like this +sort of uh uh allowing companies to do + + align:start position:0% +sort of uh uh allowing companies to do + + + align:start position:0% +sort of uh uh allowing companies to do +these sort of things I think is that + + align:start position:0% +these sort of things I think is that + + + align:start position:0% +these sort of things I think is that +whereas in some situations you can see + + align:start position:0% +whereas in some situations you can see + + + align:start position:0% +whereas in some situations you can see +the Merit like directly say if I'm bank + + align:start position:0% +the Merit like directly say if I'm bank + + + align:start position:0% +the Merit like directly say if I'm bank +and there's this uh there's this uh + + align:start position:0% +and there's this uh there's this uh + + + align:start position:0% +and there's this uh there's this uh +candidate that I know is going to like + + align:start position:0% +candidate that I know is going to like + + + align:start position:0% +candidate that I know is going to like +force me to have like higher standards + + align:start position:0% +force me to have like higher standards + + + align:start position:0% +force me to have like higher standards +and all that stuff I might might want to + + align:start position:0% +and all that stuff I might might want to + + + align:start position:0% +and all that stuff I might might want to +like uh go for the other candidate but I + + align:start position:0% +like uh go for the other candidate but I + + + align:start position:0% +like uh go for the other candidate but I +think that having these sort of rules + + align:start position:0% +think that having these sort of rules + + + align:start position:0% +think that having these sort of rules +like allows for companies to to go like + + align:start position:0% +like allows for companies to to go like + + + align:start position:0% +like allows for companies to to go like +in these like murky territory where + + align:start position:0% +in these like murky territory where + + + align:start position:0% +in these like murky territory where +you're kind of influencing things you + + align:start position:0% +you're kind of influencing things you + + + align:start position:0% +you're kind of influencing things you +may shouldn't you probably shouldn't and + + align:start position:0% +may shouldn't you probably shouldn't and + + + align:start position:0% +may shouldn't you probably shouldn't and +like your uh you increase your uh in + + align:start position:0% +like your uh you increase your uh in + + + align:start position:0% +like your uh you increase your uh in +terms of like you're arguing you don't + + align:start position:0% +terms of like you're arguing you don't + + + align:start position:0% +terms of like you're arguing you don't +like the decision sorry you don't like + + align:start position:0% +like the decision sorry you don't like + + + align:start position:0% +like the decision sorry you don't like +the decision you don't like what I'm + + align:start position:0% +the decision you don't like what I'm + + + align:start position:0% +the decision you don't like what I'm +trying to say the decision's there what + + align:start position:0% +trying to say the decision's there what + + + align:start position:0% +trying to say the decision's there what +I'm trying to say is that like as a as a + + align:start position:0% +I'm trying to say is that like as a as a + + + align:start position:0% +I'm trying to say is that like as a as a +CEO doing something is uh supposedly to + + align:start position:0% +CEO doing something is uh supposedly to + + + align:start position:0% +CEO doing something is uh supposedly to +improve like the the company's position + + align:start position:0% +improve like the the company's position + + + align:start position:0% +improve like the the company's position +is is like completely subjective because + + align:start position:0% +is is like completely subjective because + + + align:start position:0% +is is like completely subjective because +they're M like doing the giving money to + + align:start position:0% +they're M like doing the giving money to + + + align:start position:0% +they're M like doing the giving money to +cand X might be interpreted okay I'm I'm + + align:start position:0% +cand X might be interpreted okay I'm I'm + + + align:start position:0% +cand X might be interpreted okay I'm I'm +doing it because I want him to support + + align:start position:0% +doing it because I want him to support + + + align:start position:0% +doing it because I want him to support +this which is good for my company but + + align:start position:0% +this which is good for my company but + + + align:start position:0% +this which is good for my company but +then there are whole other things that + + align:start position:0% +then there are whole other things that + + + align:start position:0% +then there are whole other things that +you're doing by doing so this I think is + + align:start position:0% +you're doing by doing so this I think is + + + align:start position:0% +you're doing by doing so this I think is +more of a negative publicity than + + align:start position:0% +more of a negative publicity than + + + align:start position:0% +more of a negative publicity than +positive publicity in the sense that + + align:start position:0% +positive publicity in the sense that + + + align:start position:0% +positive publicity in the sense that +you're influencing uh decision making + + align:start position:0% +you're influencing uh decision making + + + align:start position:0% +you're influencing uh decision making +because it might be that you're doing it + + align:start position:0% +because it might be that you're doing it + + + align:start position:0% +because it might be that you're doing it +for him uh to support action a but for + + align:start position:0% +for him uh to support action a but for + + + align:start position:0% +for him uh to support action a but for +action B you also have influence on him + + align:start position:0% +action B you also have influence on him + + + align:start position:0% +action B you also have influence on him +and then that might be that you don't + + align:start position:0% +and then that might be that you don't + + + align:start position:0% +and then that might be that you don't +want have apple to have influence on he + + align:start position:0% +want have apple to have influence on he + + + align:start position:0% +want have apple to have influence on he +decides on something else I've been on + + align:start position:0% +decides on something else I've been on + + + align:start position:0% +decides on something else I've been on +the board of a company that had one of + + align:start position:0% +the board of a company that had one of + + + align:start position:0% +the board of a company that had one of +these ordinary + + align:start position:0% +these ordinary + + + align:start position:0% +these ordinary +packs uh and the directors and the + + align:start position:0% +packs uh and the directors and the + + + align:start position:0% +packs uh and the directors and the +officers chipped + + align:start position:0% +officers chipped + + + align:start position:0% +officers chipped +in + + align:start position:0% +in + + + align:start position:0% +in +and we made contributions this was a + + align:start position:0% +and we made contributions this was a + + + align:start position:0% +and we made contributions this was a +company located on Wall Street and we + + align:start position:0% +company located on Wall Street and we + + + align:start position:0% +company located on Wall Street and we +made and we were a regulated company a + + align:start position:0% +made and we were a regulated company a + + + align:start position:0% +made and we were a regulated company a +Securities Exchange and we made + + align:start position:0% +Securities Exchange and we made + + + align:start position:0% +Securities Exchange and we made +contributions to both New York senators + + align:start position:0% +contributions to both New York senators + + + align:start position:0% +contributions to both New York senators +and to the congressman from Wall Street + + align:start position:0% +and to the congressman from Wall Street + + + align:start position:0% +and to the congressman from Wall Street +so that they'd return our phone calls + + align:start position:0% +so that they'd return our phone calls + + + align:start position:0% +so that they'd return our phone calls +basically we're not going to buy + + align:start position:0% +basically we're not going to buy + + + align:start position:0% +basically we're not going to buy +influence if they're not concerned about + + align:start position:0% +influence if they're not concerned about + + + align:start position:0% +influence if they're not concerned about +the fate of uh companies on Wall Street + + align:start position:0% +the fate of uh companies on Wall Street + + + align:start position:0% +the fate of uh companies on Wall Street +then they're in a a lot of trouble but + + align:start position:0% +then they're in a a lot of trouble but + + + align:start position:0% +then they're in a a lot of trouble but +to basically get your phone call + + align:start position:0% +to basically get your phone call + + + align:start position:0% +to basically get your phone call +returned you make a few thousand + + align:start position:0% +returned you make a few thousand + + + align:start position:0% +returned you make a few thousand +contribution that's a that's different + + align:start position:0% +contribution that's a that's different + + + align:start position:0% +contribution that's a that's different +from giving $10 million to support n + + align:start position:0% +from giving $10 million to support n + + + align:start position:0% +from giving $10 million to support n +Gingrich um but so Marie you had a point + + align:start position:0% +Gingrich um but so Marie you had a point + + + align:start position:0% +Gingrich um but so Marie you had a point +or you were you were waving no sorry + + align:start position:0% +or you were you were waving no sorry + + + align:start position:0% +or you were you were waving no sorry +okay + + align:start position:0% +okay + + + align:start position:0% +okay +Jacob kind a question is it Poss for an + + align:start position:0% +Jacob kind a question is it Poss for an + + + align:start position:0% +Jacob kind a question is it Poss for an +international corporation to contribute + + align:start position:0% +international corporation to contribute + + + align:start position:0% +international corporation to contribute +to an American politician or like if + + align:start position:0% +to an American politician or like if + + + align:start position:0% +to an American politician or like if +it's an American company with say + + align:start position:0% +it's an American company with say + + + align:start position:0% +it's an American company with say +foreign Executives who are making the + + align:start position:0% +foreign Executives who are making the + + + align:start position:0% +foreign Executives who are making the +decision whether appropriation Don any + + align:start position:0% +decision whether appropriation Don any + + + align:start position:0% +decision whether appropriation Don any +Mone + + align:start position:0% +Mone + + + align:start position:0% +Mone +to well if if they have a if they have a + + align:start position:0% +to well if if they have a if they have a + + + align:start position:0% +to well if if they have a if they have a +subsidiary that is a US person okay so + + align:start position:0% +subsidiary that is a US person okay so + + + align:start position:0% +subsidiary that is a US person okay so +if you have a a subsidiary that has a US + + align:start position:0% +if you have a a subsidiary that has a US + + + align:start position:0% +if you have a a subsidiary that has a US +Charter then presumably that entity can + + align:start position:0% +Charter then presumably that entity can + + + align:start position:0% +Charter then presumably that entity can +you can't you can't make direct + + align:start position:0% +you can't you can't make direct + + + align:start position:0% +you can't you can't make direct +contributions in well sorry they can't + + align:start position:0% +contributions in well sorry they can't + + + align:start position:0% +contributions in well sorry they can't +make Direct contributions to the + + align:start position:0% +make Direct contributions to the + + + align:start position:0% +make Direct contributions to the +candidate in any case the question is + + align:start position:0% +candidate in any case the question is + + + align:start position:0% +candidate in any case the question is +can you contribute to a Super PAC I I + + align:start position:0% +can you contribute to a Super PAC I I + + + align:start position:0% +can you contribute to a Super PAC I I +doubt a foreign corporation doesn't have + + align:start position:0% +doubt a foreign corporation doesn't have + + + align:start position:0% +doubt a foreign corporation doesn't have +us rights of free speech so I've never + + align:start position:0% +us rights of free speech so I've never + + + align:start position:0% +us rights of free speech so I've never +heard it brought up but I don't think I + + align:start position:0% +heard it brought up but I don't think I + + + align:start position:0% +heard it brought up but I don't think I +think it could be barred question + + align:start position:0% +think it could be barred question + + + align:start position:0% +think it could be barred question +whether it should be done but I just set + + align:start position:0% +whether it should be done but I just set + + + align:start position:0% +whether it should be done but I just set +up I just set up a us company if I + + align:start position:0% +up I just set up a us company if I + + + align:start position:0% +up I just set up a us company if I +wanted to do that well could yeah in + + align:start position:0% +wanted to do that well could yeah in + + + align:start position:0% +wanted to do that well could yeah in +which case could there be anti-American + + align:start position:0% +which case could there be anti-American + + + align:start position:0% +which case could there be anti-American +interests like influencing our politi so + + align:start position:0% +interests like influencing our politi so + + + align:start position:0% +interests like influencing our politi so +I actually found it found it interesting + + align:start position:0% +I actually found it found it interesting + + + align:start position:0% +I actually found it found it interesting +I looked + + align:start position:0% +I looked + + + align:start position:0% +I looked +at uh there's a foundation called + + align:start position:0% +at uh there's a foundation called + + + align:start position:0% +at uh there's a foundation called +sunlight Foundation you can find them on + + align:start position:0% +sunlight Foundation you can find them on + + + align:start position:0% +sunlight Foundation you can find them on +the web and they looked at who's making + + align:start position:0% +the web and they looked at who's making + + + align:start position:0% +the web and they looked at who's making +these + + align:start position:0% +these + + + align:start position:0% +these +contributions and in fact you don't find + + align:start position:0% +contributions and in fact you don't find + + + align:start position:0% +contributions and in fact you don't find +any publicly held contrib uh I couldn't + + align:start position:0% +any publicly held contrib uh I couldn't + + + align:start position:0% +any publicly held contrib uh I couldn't +find any um certainly no company I'd + + align:start position:0% +find any um certainly no company I'd + + + align:start position:0% +find any um certainly no company I'd +ever heard of is on the list for + + align:start position:0% +ever heard of is on the list for + + + align:start position:0% +ever heard of is on the list for +contributions above 25 20,000 actually + + align:start position:0% +contributions above 25 20,000 actually + + + align:start position:0% +contributions above 25 20,000 actually +was their cut lots of private + + align:start position:0% +was their cut lots of private + + + align:start position:0% +was their cut lots of private +corporations + + align:start position:0% +corporations + + + align:start position:0% +corporations +individuals unions Partnerships the only + + align:start position:0% +individuals unions Partnerships the only + + + align:start position:0% +individuals unions Partnerships the only +publicly traded company I could find is + + align:start position:0% +publicly traded company I could find is + + + align:start position:0% +publicly traded company I could find is +console which is a Coal Company as far + + align:start position:0% +console which is a Coal Company as far + + + align:start position:0% +console which is a Coal Company as far +as I can tell I don't know them well + + align:start position:0% +as I can tell I don't know them well + + + align:start position:0% +as I can tell I don't know them well +they gave + + align:start position:0% +they gave + + + align:start position:0% +they gave +$125,000 to a Romney + + align:start position:0% +$125,000 to a Romney + + + align:start position:0% +$125,000 to a Romney +pack and you have to ask + + align:start position:0% +pack and you have to ask + + + align:start position:0% +pack and you have to ask +yourself + + align:start position:0% +yourself + + + align:start position:0% +yourself +why I assume that's a CEO who leans + + align:start position:0% +why I assume that's a CEO who leans + + + align:start position:0% +why I assume that's a CEO who leans +Romney and whose board is + + align:start position:0% +Romney and whose board is + + + align:start position:0% +Romney and whose board is +captive which is not unheard of that the + + align:start position:0% +captive which is not unheard of that the + + + align:start position:0% +captive which is not unheard of that the +board is opposed of his friends or her + + align:start position:0% +board is opposed of his friends or her + + + align:start position:0% +board is opposed of his friends or her +friends I don't know who the CEO is um + + align:start position:0% +friends I don't know who the CEO is um + + + align:start position:0% +friends I don't know who the CEO is um +so it's interesting that most + + align:start position:0% +so it's interesting that most + + + align:start position:0% +so it's interesting that most +corporations most large corporations + + align:start position:0% +corporations most large corporations + + + align:start position:0% +corporations most large corporations +Apple Etc are not playing this + + align:start position:0% +Apple Etc are not playing this + + + align:start position:0% +Apple Etc are not playing this +game even though by law they + + align:start position:0% +game even though by law they + + + align:start position:0% +game even though by law they +can I just find that interesting and it + + align:start position:0% +can I just find that interesting and it + + + align:start position:0% +can I just find that interesting and it +has to do with what they think their + + align:start position:0% +has to do with what they think their + + + align:start position:0% +has to do with what they think their +role as CEO is and how they should + + align:start position:0% +role as CEO is and how they should + + + align:start position:0% +role as CEO is and how they should +behave as I said I can only find one + + align:start position:0% +behave as I said I can only find one + + + align:start position:0% +behave as I said I can only find one +publicly traded company there are a lot + + align:start position:0% +publicly traded company there are a lot + + + align:start position:0% +publicly traded company there are a lot +of you know so and so family company + + align:start position:0% +of you know so and so family company + + + align:start position:0% +of you know so and so family company +contributes and you know that's a family + + align:start position:0% +contributes and you know that's a family + + + align:start position:0% +contributes and you know that's a family +company it's effectively a + + align:start position:0% +company it's effectively a + + + align:start position:0% +company it's effectively a +partnership so not publicly + + align:start position:0% +partnership so not publicly + + + align:start position:0% +partnership so not publicly +traded so + + align:start position:0% +traded so + + + align:start position:0% +traded so +it which + + align:start position:0% +it which + + + align:start position:0% +it which +is + + align:start position:0% +is + + + align:start position:0% +is +yeah yeah yeah oh yeah oh yeah AR that + + align:start position:0% +yeah yeah yeah oh yeah oh yeah AR that + + + align:start position:0% +yeah yeah yeah oh yeah oh yeah AR that +maybe all the companies don't think + + align:start position:0% +maybe all the companies don't think + + + align:start position:0% +maybe all the companies don't think +Romney is going to win so nobody's + + align:start position:0% +Romney is going to win so nobody's + + + align:start position:0% +Romney is going to win so nobody's +putting any money into + + align:start position:0% +putting any money into + + + align:start position:0% +putting any money into +it there's a lot of money going in and + + align:start position:0% +it there's a lot of money going in and + + + align:start position:0% +it there's a lot of money going in and +what we don't + + align:start position:0% +what we don't + + + align:start position:0% +what we don't +see um if you look at what finance's + + align:start position:0% +see um if you look at what finance's + + + align:start position:0% +see um if you look at what finance's +senatorial and Congressional + + align:start position:0% +senatorial and Congressional + + + align:start position:0% +senatorial and Congressional +campaigns you will see plain old + + align:start position:0% +campaigns you will see plain old + + + align:start position:0% +campaigns you will see plain old +ordinary packs contributing uh like the + + align:start position:0% +ordinary packs contributing uh like the + + + align:start position:0% +ordinary packs contributing uh like the +one I described where I want to make + + align:start position:0% +one I described where I want to make + + + align:start position:0% +one I described where I want to make +sure my phone call gets returned uh and + + align:start position:0% +sure my phone call gets returned uh and + + + align:start position:0% +sure my phone call gets returned uh and +I want you to be sure that you worry + + align:start position:0% +I want you to be sure that you worry + + + align:start position:0% +I want you to be sure that you worry +about wheat Farmers so the wheat Farmers + + align:start position:0% +about wheat Farmers so the wheat Farmers + + + align:start position:0% +about wheat Farmers so the wheat Farmers +Association well but + + align:start position:0% +Association well but + + + align:start position:0% +Association well but +um it is interesting Obama has a pack + + align:start position:0% +um it is interesting Obama has a pack + + + align:start position:0% +um it is interesting Obama has a pack +but they're not sure he's going to win + + align:start position:0% +but they're not sure he's going to win + + + align:start position:0% +but they're not sure he's going to win +either + + align:start position:0% +either + + + align:start position:0% +either +so + + align:start position:0% +so + + + align:start position:0% +so +anyway we'll come back to to lobbying + + align:start position:0% +anyway we'll come back to to lobbying + + + align:start position:0% +anyway we'll come back to to lobbying +and and contributions it's more for + + align:start position:0% +and and contributions it's more for + + + align:start position:0% +and and contributions it's more for +Access than for votes I think but okay + + align:start position:0% +Access than for votes I think but okay + + + align:start position:0% +Access than for votes I think but okay +yes Stephen uh just a quick question for + + align:start position:0% +yes Stephen uh just a quick question for + + + align:start position:0% +yes Stephen uh just a quick question for +the you mentioned that there were + + align:start position:0% +the you mentioned that there were + + + align:start position:0% +the you mentioned that there were +private companies that were still doing + + align:start position:0% +private companies that were still doing + + + align:start position:0% +private companies that were still doing +this type of stuff could it be that some + + align:start position:0% +this type of stuff could it be that some + + + align:start position:0% +this type of stuff could it be that some +of the public companies are going + + align:start position:0% +of the public companies are going + + + align:start position:0% +of the public companies are going +through those means to make their + + align:start position:0% +through those means to make their + + + align:start position:0% +through those means to make their +donations I I think and they've talked + + align:start position:0% +donations I I think and they've talked + + + align:start position:0% +donations I I think and they've talked +about it that there are some companies + + align:start position:0% +about it that there are some companies + + + align:start position:0% +about it that there are some companies +that are dummy companies that get set up + + align:start position:0% +that are dummy companies that get set up + + + align:start position:0% +that are dummy companies that get set up +um uh but mostly it hides Rich + + align:start position:0% +um uh but mostly it hides Rich + + + align:start position:0% +um uh but mostly it hides Rich +individuals + + align:start position:0% +individuals + + + align:start position:0% +individuals +ual so I you can't follow through from + + align:start position:0% +ual so I you can't follow through from + + + align:start position:0% +ual so I you can't follow through from +this website but if you read in the + + align:start position:0% +this website but if you read in the + + + align:start position:0% +this website but if you read in the +paper they talk about trying to track + + align:start position:0% +paper they talk about trying to track + + + align:start position:0% +paper they talk about trying to track +down donors and getting a post office + + align:start position:0% +down donors and getting a post office + + + align:start position:0% +down donors and getting a post office +box so it's a company it has a post + + align:start position:0% +box so it's a company it has a post + + + align:start position:0% +box so it's a company it has a post +office box it's legally + + align:start position:0% +office box it's legally + + + align:start position:0% +office box it's legally +Incorporated uh it's documents aren't + + align:start position:0% +Incorporated uh it's documents aren't + + + align:start position:0% +Incorporated uh it's documents aren't +public because it's closely held so + + align:start position:0% +public because it's closely held so + + + align:start position:0% +public because it's closely held so +that's a that's a mask behind which some + + align:start position:0% +that's a that's a mask behind which some + + + align:start position:0% +that's a that's a mask behind which some +rich person is hiding I don't think it + + align:start position:0% +rich person is hiding I don't think it + + + align:start position:0% +rich person is hiding I don't think it +would be a sane thing for a big publicly + + align:start position:0% +would be a sane thing for a big publicly + + + align:start position:0% +would be a sane thing for a big publicly +traded company to hide that way because + + align:start position:0% +traded company to hide that way because + + + align:start position:0% +traded company to hide that way because +if there were enough money somebody will + + align:start position:0% +if there were enough money somebody will + + + align:start position:0% +if there were enough money somebody will +find it out I mean there's a lot there's + + align:start position:0% +find it out I mean there's a lot there's + + + align:start position:0% +find it out I mean there's a lot there's +a lot somebody gives a million dollars + + align:start position:0% +a lot somebody gives a million dollars + + + align:start position:0% +a lot somebody gives a million dollars +and they're hiding it's a good story if + + align:start position:0% +and they're hiding it's a good story if + + + align:start position:0% +and they're hiding it's a good story if +you can figure out who it is if it turns + + align:start position:0% +you can figure out who it is if it turns + + + align:start position:0% +you can figure out who it is if it turns +out to be apple it's a scandal so that's + + align:start position:0% +out to be apple it's a scandal so that's + + + align:start position:0% +out to be apple it's a scandal so that's +too risky David um could it be possible + + align:start position:0% +too risky David um could it be possible + + + align:start position:0% +too risky David um could it be possible +that some of the larger companies whose + + align:start position:0% +that some of the larger companies whose + + + align:start position:0% +that some of the larger companies whose +um Financial contributions would make a + + align:start position:0% +um Financial contributions would make a + + + align:start position:0% +um Financial contributions would make a +significant impact in the campaign are + + align:start position:0% +significant impact in the campaign are + + + align:start position:0% +significant impact in the campaign are +companies that would already have access + + align:start position:0% +companies that would already have access + + + align:start position:0% +companies that would already have access +anyways if D called up you know the + + align:start position:0% +anyways if D called up you know the + + + align:start position:0% +anyways if D called up you know the +White House and said if you really need + + align:start position:0% +White House and said if you really need + + + align:start position:0% +White House and said if you really need +to talk to someone in treasury or + + align:start position:0% +to talk to someone in treasury or + + + align:start position:0% +to talk to someone in treasury or +something they could probably get + + align:start position:0% +something they could probably get + + + align:start position:0% +something they could probably get +a yeah apple doesn't need to buy access + + align:start position:0% +a yeah apple doesn't need to buy access + + + align:start position:0% +a yeah apple doesn't need to buy access +um this Mining Company May backing + + align:start position:0% +um this Mining Company May backing + + + align:start position:0% +um this Mining Company May backing +Romney is not the most obvious way to do + + align:start position:0% +Romney is not the most obvious way to do + + + align:start position:0% +Romney is not the most obvious way to do +it so I assume that this is just a + + align:start position:0% +it so I assume that this is just a + + + align:start position:0% +it so I assume that this is just a +personal preference of somebody and a + + align:start position:0% +personal preference of somebody and a + + + align:start position:0% +personal preference of somebody and a +board that says yeah sure it's 125,000 + + align:start position:0% +board that says yeah sure it's 125,000 + + + align:start position:0% +board that says yeah sure it's 125,000 +who cares we'll just cut your bonus okay + + align:start position:0% +who cares we'll just cut your bonus okay + + + align:start position:0% +who cares we'll just cut your bonus okay +um I it's it's an interesting + + align:start position:0% +um I it's it's an interesting + + + align:start position:0% +um I it's it's an interesting +an interesting issue of the role of the + + align:start position:0% +an interesting issue of the role of the + + + align:start position:0% +an interesting issue of the role of the +the role of the of the corporation but + + align:start position:0% +the role of the of the corporation but + + + align:start position:0% +the role of the of the corporation but +it's also interesting what most of them + + align:start position:0% +it's also interesting what most of them + + + align:start position:0% +it's also interesting what most of them +choose to do let's go to Upstate New + + align:start position:0% +choose to do let's go to Upstate New + + + align:start position:0% +choose to do let's go to Upstate New +York and do F Malahide uh I just told + + align:start position:0% +York and do F Malahide uh I just told + + + align:start position:0% +York and do F Malahide uh I just told +you what it I just answered that + + align:start position:0% +you what it I just answered that + + + align:start position:0% +you what it I just answered that +question so we've lost that one uh + + align:start position:0% +question so we've lost that one uh + + + align:start position:0% +question so we've lost that one uh +what's Darren's issue in the case + + align:start position:0% +what's Darren's issue in the case + + + align:start position:0% +what's Darren's issue in the case +Matthew uh he's in of + + align:start position:0% + + + + align:start position:0% + +the + + align:start position:0% +the + + + align:start position:0% +the +the but what what problem is he + + align:start position:0% +the but what what problem is he + + + align:start position:0% +the but what what problem is he +addressing or what opportunity is he + + align:start position:0% +addressing or what opportunity is he + + + align:start position:0% +addressing or what opportunity is he +addressing what's the wasted heat a lot + + align:start position:0% +addressing what's the wasted heat a lot + + + align:start position:0% +addressing what's the wasted heat a lot +of wasted heat they're venting a lot of + + align:start position:0% +of wasted heat they're venting a lot of + + + align:start position:0% +of wasted heat they're venting a lot of +a lot of steam and anything else it does + + align:start position:0% +a lot of steam and anything else it does + + + align:start position:0% +a lot of steam and anything else it does +Scott also the steam causes damage to + + align:start position:0% +Scott also the steam causes damage to + + + align:start position:0% +Scott also the steam causes damage to +the building it uh corrodes the + + align:start position:0% +the building it uh corrodes the + + + align:start position:0% +the building it uh corrodes the +materials in the building and also + + align:start position:0% +materials in the building and also + + + align:start position:0% +materials in the building and also +causes an ice sheet on the ground which + + align:start position:0% +causes an ice sheet on the ground which + + + align:start position:0% +causes an ice sheet on the ground which +is dangerous for the lovely stuff lovely + + align:start position:0% +is dangerous for the lovely stuff lovely + + + align:start position:0% +is dangerous for the lovely stuff lovely +stuff okay that's what he's got + + align:start position:0% +stuff okay that's what he's got + + + align:start position:0% +stuff okay that's what he's got +he has three options to to deal with + + align:start position:0% +he has three options to to deal with + + + align:start position:0% +he has three options to to deal with +these that he considers first of all do + + align:start position:0% +these that he considers first of all do + + + align:start position:0% +these that he considers first of all do +you call what they are + + align:start position:0% + + + + align:start position:0% + +Rachel + + align:start position:0% + + + + align:start position:0% + +yep lithium bromine Romine + + align:start position:0% + + + + align:start position:0% + +yeah anybody got anybody got the third + + align:start position:0% +yeah anybody got anybody got the third + + + align:start position:0% +yeah anybody got anybody got the third +one W third one is to uh speed theow of + + align:start position:0% +one W third one is to uh speed theow of + + + align:start position:0% +one W third one is to uh speed theow of +water speed the flow of water through so + + align:start position:0% +water speed the flow of water through so + + + align:start position:0% +water speed the flow of water through so +it just comes out hot it doesn't come + + align:start position:0% +it just comes out hot it doesn't come + + + align:start position:0% +it just comes out hot it doesn't come +out as + + align:start position:0% +out as + + + align:start position:0% +out as +Steam um + + align:start position:0% +Steam um + + + align:start position:0% +Steam um +okay why is he focused on combined heat + + align:start position:0% +okay why is he focused on combined heat + + + align:start position:0% +okay why is he focused on combined heat +and power why is he focused on cenation + + align:start position:0% +and power why is he focused on cenation + + + align:start position:0% +and power why is he focused on cenation +what are the issues with the others or + + align:start position:0% +what are the issues with the others or + + + align:start position:0% +what are the issues with the others or +the advantage of this in Broad + + align:start position:0% +the advantage of this in Broad + + + align:start position:0% +the advantage of this in Broad +terms Kirsten oh um the disadvantage for + + align:start position:0% +terms Kirsten oh um the disadvantage for + + + align:start position:0% +terms Kirsten oh um the disadvantage for +the speeding up the process in producing + + align:start position:0% +the speeding up the process in producing + + + align:start position:0% +the speeding up the process in producing +hot water was that they didn't have a + + align:start position:0% +hot water was that they didn't have a + + + align:start position:0% +hot water was that they didn't have a +good place to put the hot water + + align:start position:0% +good place to put the hot water + + + align:start position:0% +good place to put the hot water +especially in the summer they didn't + + align:start position:0% +especially in the summer they didn't + + + align:start position:0% +especially in the summer they didn't +want to just dump it into the + + align:start position:0% +want to just dump it into the + + + align:start position:0% +want to just dump it into the +environment because that might have a + + align:start position:0% +environment because that might have a + + + align:start position:0% +environment because that might have a +detrimental effect to the environment + + align:start position:0% +detrimental effect to the environment + + + align:start position:0% +detrimental effect to the environment +right and theage they had to just dump + + align:start position:0% +right and theage they had to just dump + + + align:start position:0% +right and theage they had to just dump +it in a cool stream y yeah they in the + + align:start position:0% +it in a cool stream y yeah they in the + + + align:start position:0% +it in a cool stream y yeah they in the +win it would be good they could keep the + + align:start position:0% +win it would be good they could keep the + + + align:start position:0% +win it would be good they could keep the +buildings without using too much other + + align:start position:0% +buildings without using too much other + + + align:start position:0% +buildings without using too much other +electricity but Su be problem and the + + align:start position:0% +electricity but Su be problem and the + + + align:start position:0% +electricity but Su be problem and the +disadvantage of lium gr was that it + + align:start position:0% +disadvantage of lium gr was that it + + + align:start position:0% +disadvantage of lium gr was that it +would require a lot more um + + align:start position:0% +would require a lot more um + + + align:start position:0% +would require a lot more um +infrastructure + + align:start position:0% +infrastructure + + + align:start position:0% +infrastructure +changes okay so we focused on combined + + align:start position:0% +changes okay so we focused on combined + + + align:start position:0% +changes okay so we focused on combined +heat and power + + align:start position:0% +heat and power + + + align:start position:0% +heat and power +um did anybody look at this is this + + align:start position:0% +um did anybody look at this is this + + + align:start position:0% +um did anybody look at this is this +a if it saves money does it save much + + align:start position:0% +a if it saves money does it save much + + + align:start position:0% +a if it saves money does it save much +money relative to the firm's Revenue to + + align:start position:0% +money relative to the firm's Revenue to + + + align:start position:0% +money relative to the firm's Revenue to +that plant's + + align:start position:0% + + + + align:start position:0% + +Revenue not really um in terms of uh I + + align:start position:0% +Revenue not really um in terms of uh I + + + align:start position:0% +Revenue not really um in terms of uh I +think power SA + + align:start position:0% +think power SA + + + align:start position:0% +think power SA +or cleaning the water or treating the + + align:start position:0% +or cleaning the water or treating the + + + align:start position:0% +or cleaning the water or treating the +water so that they can making it soft + + align:start position:0% +water so that they can making it soft + + + align:start position:0% +water so that they can making it soft +because it's usually typically hard um + + align:start position:0% +because it's usually typically hard um + + + align:start position:0% +because it's usually typically hard um +you save 75% but that's only like 10,000 + + align:start position:0% +you save 75% but that's only like 10,000 + + + align:start position:0% +you save 75% but that's only like 10,000 +or $8,000 but this is they make millions + + align:start position:0% +or $8,000 but this is they make millions + + + align:start position:0% +or $8,000 but this is they make millions +upon millions of dollars and savings are + + align:start position:0% +upon millions of dollars and savings are + + + align:start position:0% +upon millions of dollars and savings are +in the low hundreds thousand low + + align:start position:0% +in the low hundreds thousand low + + + align:start position:0% +in the low hundreds thousand low +hundreds thousands right if you + + align:start position:0% +hundreds thousands right if you + + + align:start position:0% +hundreds thousands right if you +calculate + + align:start position:0% +calculate + + + align:start position:0% +calculate +there's a there's a typo in the case + + align:start position:0% +there's a there's a typo in the case + + + align:start position:0% +there's a there's a typo in the case +where it says it talks about 5 days + + align:start position:0% +where it says it talks about 5 days + + + align:start position:0% +where it says it talks about 5 days +absence being + + align:start position:0% +absence being + + + align:start position:0% +absence being +.01% it's in fact 1% and if you use the + + align:start position:0% +.01% it's in fact 1% and if you use the + + + align:start position:0% +.01% it's in fact 1% and if you use the +other numbers that plant has an annual + + align:start position:0% +other numbers that plant has an annual + + + align:start position:0% +other numbers that plant has an annual +revenue of about $5.1 million based on + + align:start position:0% +revenue of about $5.1 million based on + + + align:start position:0% +revenue of about $5.1 million based on +the production numbers they give you + + align:start position:0% +the production numbers they give you + + + align:start position:0% +the production numbers they give you +work the numbers Veronica + + align:start position:0% +work the numbers Veronica + + + align:start position:0% +work the numbers Veronica +good so what I get is that that the + + align:start position:0% +good so what I get is that that the + + + align:start position:0% +good so what I get is that that the +savings would be maybe 2% of Revenue the + + align:start position:0% +savings would be maybe 2% of Revenue the + + + align:start position:0% +savings would be maybe 2% of Revenue the +pre-tax savings to compare pre-tax to + + align:start position:0% +pre-tax savings to compare pre-tax to + + + align:start position:0% +pre-tax savings to compare pre-tax to +pre-tax + + align:start position:0% +pre-tax + + + align:start position:0% +pre-tax +okay so not a big deal we're going to + + align:start position:0% +okay so not a big deal we're going to + + + align:start position:0% +okay so not a big deal we're going to +talk about whether it's a good deal and + + align:start position:0% +talk about whether it's a good deal and + + + align:start position:0% +talk about whether it's a good deal and +we're going to talk about whether + + align:start position:0% +we're going to talk about whether + + + align:start position:0% +we're going to talk about whether +they'll do it let me just do a short + + align:start position:0% +they'll do it let me just do a short + + + align:start position:0% +they'll do it let me just do a short +Riff + + align:start position:0% +Riff + + + align:start position:0% +Riff +on uh combine heat and power and waste + + align:start position:0% +on uh combine heat and power and waste + + + align:start position:0% +on uh combine heat and power and waste +energy + + align:start position:0% +energy + + + align:start position:0% +energy +um it's interesting if you if you look + + align:start position:0% +um it's interesting if you if you look + + + align:start position:0% +um it's interesting if you if you look +at + + align:start position:0% +at + + + align:start position:0% +at +the rejected energy versus usable energy + + align:start position:0% +the rejected energy versus usable energy + + + align:start position:0% +the rejected energy versus usable energy +B sector right so this is + + align:start position:0% +B sector right so this is + + + align:start position:0% +B sector right so this is +waste Transportation 75% of what goes in + + align:start position:0% +waste Transportation 75% of what goes in + + + align:start position:0% +waste Transportation 75% of what goes in +comes out as waste + + align:start position:0% +comes out as waste + + + align:start position:0% +comes out as waste +energy uh electric generation just about + + align:start position:0% +energy uh electric generation just about + + + align:start position:0% +energy uh electric generation just about +a third and every place else about + + align:start position:0% +a third and every place else about + + + align:start position:0% +a third and every place else about +20% + + align:start position:0% +20% + + + align:start position:0% +20% +um and you all know the answer to that + + align:start position:0% +um and you all know the answer to that + + + align:start position:0% +um and you all know the answer to that +what form the waste takes yes waste + + align:start position:0% +what form the waste takes yes waste + + + align:start position:0% +what form the waste takes yes waste +energy is + + align:start position:0% +energy is + + + align:start position:0% +energy is +usually heat yeah yep so I mean oops + + align:start position:0% +usually heat yeah yep so I mean oops + + + align:start position:0% +usually heat yeah yep so I mean oops +backwards this + + align:start position:0% +backwards this + + + align:start position:0% +backwards this +one transportation's tough cuz cars are + + align:start position:0% +one transportation's tough cuz cars are + + + align:start position:0% +one transportation's tough cuz cars are +not all that that efficient really um + + align:start position:0% +not all that that efficient really um + + + align:start position:0% +not all that that efficient really um +and uh but for public transportation + + align:start position:0% +and uh but for public transportation + + + align:start position:0% +and uh but for public transportation +this is a tough one uh residential and + + align:start position:0% +this is a tough one uh residential and + + + align:start position:0% +this is a tough one uh residential and +Commercial an awful lot of the energy is + + align:start position:0% +Commercial an awful lot of the energy is + + + align:start position:0% +Commercial an awful lot of the energy is +going into heating and cooling you can + + align:start position:0% +going into heating and cooling you can + + + align:start position:0% +going into heating and cooling you can +make it more efficient of course um but + + align:start position:0% +make it more efficient of course um but + + + align:start position:0% +make it more efficient of course um but +it's hard to capture what's attractive + + align:start position:0% +it's hard to capture what's attractive + + + align:start position:0% +it's hard to capture what's attractive +about + + align:start position:0% +about + + + align:start position:0% +about +industrial and + + align:start position:0% +industrial and + + + align:start position:0% +industrial and +electricity is you have high heat you + + align:start position:0% +electricity is you have high heat you + + + align:start position:0% +electricity is you have high heat you +have large delta T you have the ability + + align:start position:0% +have large delta T you have the ability + + + align:start position:0% +have large delta T you have the ability +to use a big temperature + + align:start position:0% +to use a big temperature + + + align:start position:0% +to use a big temperature +differential uh and that's the whole + + align:start position:0% +differential uh and that's the whole + + + align:start position:0% +differential uh and that's the whole +combined heat and power + + align:start position:0% +combined heat and power + + + align:start position:0% +combined heat and power +story that there really are two basic + + align:start position:0% +story that there really are two basic + + + align:start position:0% +story that there really are two basic +forms and the case kind of mentions it + + align:start position:0% +forms and the case kind of mentions it + + + align:start position:0% +forms and the case kind of mentions it +the first is called District heating + + align:start position:0% +the first is called District heating + + + align:start position:0% +the first is called District heating +where you + + align:start position:0% +where you + + + align:start position:0% +where you +take waste heat relatively low + + align:start position:0% +take waste heat relatively low + + + align:start position:0% +take waste heat relatively low +temperature from Electric generation and + + align:start position:0% +temperature from Electric generation and + + + align:start position:0% +temperature from Electric generation and +you pipe it around to heat + + align:start position:0% +you pipe it around to heat + + + align:start position:0% +you pipe it around to heat +buildings uh the Danes uh did a lot of + + align:start position:0% +buildings uh the Danes uh did a lot of + + + align:start position:0% +buildings uh the Danes uh did a lot of +this one of the readings mentioned that + + align:start position:0% +this one of the readings mentioned that + + + align:start position:0% +this one of the readings mentioned that +it's also interesting the Soviets did a + + align:start position:0% +it's also interesting the Soviets did a + + + align:start position:0% +it's also interesting the Soviets did a +lot of + + align:start position:0% +lot of + + + align:start position:0% +lot of +it um it requires you to have power + + align:start position:0% +it um it requires you to have power + + + align:start position:0% +it um it requires you to have power +plants relatively close to offices or + + align:start position:0% +plants relatively close to offices or + + + align:start position:0% +plants relatively close to offices or +factories or homes so it's not the + + align:start position:0% +factories or homes so it's not the + + + align:start position:0% +factories or homes so it's not the +greatest thing and of course it makes + + align:start position:0% +greatest thing and of course it makes + + + align:start position:0% +greatest thing and of course it makes +more sense in a cold + + align:start position:0% +more sense in a cold + + + align:start position:0% +more sense in a cold +climate using waste heat to heat + + align:start position:0% +climate using waste heat to heat + + + align:start position:0% +climate using waste heat to heat +buildings in Arizona is not + + align:start position:0% +buildings in Arizona is not + + + align:start position:0% +buildings in Arizona is not +necessarily a great a great uh a great + + align:start position:0% +necessarily a great a great uh a great + + + align:start position:0% +necessarily a great a great uh a great +deal we put in subsidies in + + align:start position:0% +deal we put in subsidies in + + + align:start position:0% +deal we put in subsidies in +1978 we'll talk a little bit about Pera + + align:start position:0% +1978 we'll talk a little bit about Pera + + + align:start position:0% +1978 we'll talk a little bit about Pera +some point that we supposed to + + align:start position:0% +some point that we supposed to + + + align:start position:0% +some point that we supposed to +encourage District + + align:start position:0% +encourage District + + + align:start position:0% +encourage District +heating uh it it didn't do much for a + + align:start position:0% +heating uh it it didn't do much for a + + + align:start position:0% +heating uh it it didn't do much for a +variety of complicated reasons it's + + align:start position:0% +variety of complicated reasons it's + + + align:start position:0% +variety of complicated reasons it's +generally acknowledged as a good thing + + align:start position:0% +generally acknowledged as a good thing + + + align:start position:0% +generally acknowledged as a good thing +in lots of places but we don't do very + + align:start position:0% +in lots of places but we don't do very + + + align:start position:0% +in lots of places but we don't do very +much of it in this country for a variety + + align:start position:0% +much of it in this country for a variety + + + align:start position:0% +much of it in this country for a variety +of reasons the + + align:start position:0% +of reasons the + + + align:start position:0% +of reasons the +other is electricity generation and + + align:start position:0% +other is electricity generation and + + + align:start position:0% +other is electricity generation and +there are sort of two versions the first + + align:start position:0% +there are sort of two versions the first + + + align:start position:0% +there are sort of two versions the first +is basic combined cycle gas turbine + + align:start position:0% +is basic combined cycle gas turbine + + + align:start position:0% +is basic combined cycle gas turbine +which is + + align:start position:0% +which is + + + align:start position:0% +which is +a relatively recent I I should be able + + align:start position:0% +a relatively recent I I should be able + + + align:start position:0% +a relatively recent I I should be able +to date it but I can't maybe the 70s + + align:start position:0% +to date it but I can't maybe the 70s + + + align:start position:0% +to date it but I can't maybe the 70s +maybe the 80s generation technology + + align:start position:0% +maybe the 80s generation technology + + + align:start position:0% +maybe the 80s generation technology +that's sort of how people are building + + align:start position:0% +that's sort of how people are building + + + align:start position:0% +that's sort of how people are building +efficient gas plants these days right + + align:start position:0% +efficient gas plants these days right + + + align:start position:0% +efficient gas plants these days right +you you run a combustion + + align:start position:0% +you you run a combustion + + + align:start position:0% +you you run a combustion +turbine which has a hot exhaust you + + align:start position:0% +turbine which has a hot exhaust you + + + align:start position:0% +turbine which has a hot exhaust you +recover the heat from the hot exhaust + + align:start position:0% +recover the heat from the hot exhaust + + + align:start position:0% +recover the heat from the hot exhaust +which makes steam which drives a steam + + align:start position:0% +which makes steam which drives a steam + + + align:start position:0% +which makes steam which drives a steam +turbine combined cycle CC so you got two + + align:start position:0% +turbine combined cycle CC so you got two + + + align:start position:0% +turbine combined cycle CC so you got two +cycles working and basically New + + align:start position:0% +cycles working and basically New + + + align:start position:0% +cycles working and basically New +Generation units this this can be a very + + align:start position:0% +Generation units this this can be a very + + + align:start position:0% +Generation units this this can be a very +this is pulled off a Seaman's website + + align:start position:0% +this is pulled off a Seaman's website + + + align:start position:0% +this is pulled off a Seaman's website +this can be a very efficient a very + + align:start position:0% +this can be a very efficient a very + + + align:start position:0% +this can be a very efficient a very +efficient technology and it's the same + + align:start position:0% +efficient technology and it's the same + + + align:start position:0% +efficient technology and it's the same +notion of capturing waste + + align:start position:0% +notion of capturing waste + + + align:start position:0% +notion of capturing waste +heat um the all you mechanical engineers + + align:start position:0% +heat um the all you mechanical engineers + + + align:start position:0% +heat um the all you mechanical engineers +know more about this than I do + + align:start position:0% +know more about this than I do + + + align:start position:0% +know more about this than I do +but others may not uh and this is the + + align:start position:0% +but others may not uh and this is the + + + align:start position:0% +but others may not uh and this is the +proposal this is the kind of proposal + + align:start position:0% +proposal this is the kind of proposal + + + align:start position:0% +proposal this is the kind of proposal +this is pulled from the case this is the + + align:start position:0% +this is pulled from the case this is the + + + align:start position:0% +this is pulled from the case this is the +kind of proposal that our friend Darren + + align:start position:0% +kind of proposal that our friend Darren + + + align:start position:0% +kind of proposal that our friend Darren +is + + align:start position:0% +is + + + align:start position:0% +is +considering uh it has to do this shows a + + align:start position:0% +considering uh it has to do this shows a + + + align:start position:0% +considering uh it has to do this shows a +boiler but it has to do as you know with + + align:start position:0% +boiler but it has to do as you know with + + + align:start position:0% +boiler but it has to do as you know with +the heat from that exothermic reaction + + align:start position:0% +the heat from that exothermic reaction + + + align:start position:0% +the heat from that exothermic reaction +that makes from Malahide so this is what + + align:start position:0% +that makes from Malahide so this is what + + + align:start position:0% +that makes from Malahide so this is what +he's considering he's considering a + + align:start position:0% +he's considering he's considering a + + + align:start position:0% +he's considering he's considering a +simple system that uh take steam to + + align:start position:0% +simple system that uh take steam to + + + align:start position:0% +simple system that uh take steam to +drive a turbine generate electricity for + + align:start position:0% +drive a turbine generate electricity for + + + align:start position:0% +drive a turbine generate electricity for +internal use maybe for sale you cool it + + align:start position:0% +internal use maybe for sale you cool it + + + align:start position:0% +internal use maybe for sale you cool it +down you recycle it you pump it through + + align:start position:0% +down you recycle it you pump it through + + + align:start position:0% +down you recycle it you pump it through +you don't re you will you will have to + + align:start position:0% +you don't re you will you will have to + + + align:start position:0% +you don't re you will you will have to +use some water but you'll pull a lot of + + align:start position:0% +use some water but you'll pull a lot of + + + align:start position:0% +use some water but you'll pull a lot of +the water a lot of the water through and + + align:start position:0% +the water a lot of the water through and + + + align:start position:0% +the water a lot of the water through and +the stuff that comes out will be + + align:start position:0% +the stuff that comes out will be + + + align:start position:0% +the stuff that comes out will be +basically cooling the uh cooling the + + align:start position:0% +basically cooling the uh cooling the + + + align:start position:0% +basically cooling the uh cooling the +condenser so this is what he's + + align:start position:0% + + + + align:start position:0% + +got there are a lot of benefits of this + + align:start position:0% +got there are a lot of benefits of this + + + align:start position:0% +got there are a lot of benefits of this +kind of system in general terms you can + + align:start position:0% +kind of system in general terms you can + + + align:start position:0% +kind of system in general terms you can +reduce energy expenses you can worry it + + align:start position:0% +reduce energy expenses you can worry it + + + align:start position:0% +reduce energy expenses you can worry it +it could avoid the risk of um uh varying + + align:start position:0% +it could avoid the risk of um uh varying + + + align:start position:0% +it could avoid the risk of um uh varying +Energy prices a lot of security good + + align:start position:0% +Energy prices a lot of security good + + + align:start position:0% +Energy prices a lot of security good +environmental benefits mom and Apple + + align:start position:0% +environmental benefits mom and Apple + + + align:start position:0% +environmental benefits mom and Apple +Pi but the + + align:start position:0% +Pi but the + + + align:start position:0% +Pi but the +question that Darren faces is is it a + + align:start position:0% +question that Darren faces is is it a + + + align:start position:0% +question that Darren faces is is it a +good + + align:start position:0% +good + + + align:start position:0% +good +deal I want to mention + + align:start position:0% +deal I want to mention + + + align:start position:0% +deal I want to mention +two concepts that the case kind of puts + + align:start position:0% +two concepts that the case kind of puts + + + align:start position:0% +two concepts that the case kind of puts +forward and the spreadsheet puts forward + + align:start position:0% +forward and the spreadsheet puts forward + + + align:start position:0% +forward and the spreadsheet puts forward +without defining them and I'll talk + + align:start position:0% +without defining them and I'll talk + + + align:start position:0% +without defining them and I'll talk +about them briefly so if you've got a + + align:start position:0% +about them briefly so if you've got a + + + align:start position:0% +about them briefly so if you've got a +vector of cash flows + + align:start position:0% +vector of cash flows + + + align:start position:0% +vector of cash flows +CT that's the Net Present Value right + + align:start position:0% +CT that's the Net Present Value right + + + align:start position:0% +CT that's the Net Present Value right +you just discount all the cash flows the + + align:start position:0% +you just discount all the cash flows the + + + align:start position:0% +you just discount all the cash flows the +case talks about the payback + + align:start position:0% +case talks about the payback + + + align:start position:0% +case talks about the payback +period and the payback period right is + + align:start position:0% +period and the payback period right is + + + align:start position:0% +period and the payback period right is +the + + align:start position:0% + + + + align:start position:0% + +smallest time such that basically you + + align:start position:0% +smallest time such that basically you + + + align:start position:0% +smallest time such that basically you +get your initial investment back + + align:start position:0% +get your initial investment back + + + align:start position:0% +get your initial investment back +assuming there's an initial investment + + align:start position:0% +assuming there's an initial investment + + + align:start position:0% +assuming there's an initial investment +up front and + + align:start position:0% +up front and + + + align:start position:0% +up front and +then uh returns in subsequent periods + + align:start position:0% +then uh returns in subsequent periods + + + align:start position:0% +then uh returns in subsequent periods +you go out as far as um uh you need to + + align:start position:0% +you go out as far as um uh you need to + + + align:start position:0% +you go out as far as um uh you need to +to recover the initial + + align:start position:0% + + + + align:start position:0% + +investment this is kind of an old a very + + align:start position:0% +investment this is kind of an old a very + + + align:start position:0% +investment this is kind of an old a very +oldfashioned way of making investment + + align:start position:0% +oldfashioned way of making investment + + + align:start position:0% +oldfashioned way of making investment +decisions and the problem with it is + + align:start position:0% +decisions and the problem with it is + + + align:start position:0% +decisions and the problem with it is +stated there because it matters what + + align:start position:0% +stated there because it matters what + + + align:start position:0% +stated there because it matters what +happens after that + + align:start position:0% +happens after that + + + align:start position:0% +happens after that +time you know I tell you that you invest + + align:start position:0% +time you know I tell you that you invest + + + align:start position:0% +time you know I tell you that you invest +$100 today you get $50 a year from now + + align:start position:0% +$100 today you get $50 a year from now + + + align:start position:0% +$100 today you get $50 a year from now +$50 two years from now the payback + + align:start position:0% +$50 two years from now the payback + + + align:start position:0% +$50 two years from now the payback +period is two years if that's all you + + align:start position:0% +period is two years if that's all you + + + align:start position:0% +period is two years if that's all you +know that's a terrible + + align:start position:0% +know that's a terrible + + + align:start position:0% +know that's a terrible +investment right you've just given me + + align:start position:0% +investment right you've just given me + + + align:start position:0% +investment right you've just given me +your money for two + + align:start position:0% +your money for two + + + align:start position:0% +your money for two +years what really matters is okay what + + align:start position:0% +years what really matters is okay what + + + align:start position:0% +years what really matters is okay what +happens after after + + align:start position:0% +happens after after + + + align:start position:0% +happens after after +that what happens after and the longer + + align:start position:0% +that what happens after and the longer + + + align:start position:0% +that what happens after and the longer +the payback all else equal it may be the + + align:start position:0% +the payback all else equal it may be the + + + align:start position:0% +the payback all else equal it may be the +worse the investment but you you can + + align:start position:0% +worse the investment but you you can + + + align:start position:0% +worse the investment but you you can +have a really + + align:start position:0% +have a really + + + align:start position:0% +have a really +terrible investment with a short payback + + align:start position:0% +terrible investment with a short payback + + + align:start position:0% +terrible investment with a short payback +period because it + + align:start position:0% +period because it + + + align:start position:0% +period because it +dies so the case talks about it I just + + align:start position:0% +dies so the case talks about it I just + + + align:start position:0% +dies so the case talks about it I just +want to caution you that by any sort of + + align:start position:0% +want to caution you that by any sort of + + + align:start position:0% +want to caution you that by any sort of +reasonable standard that's not something + + align:start position:0% +reasonable standard that's not something + + + align:start position:0% +reasonable standard that's not something +you want it's something you want to look + + align:start position:0% +you want it's something you want to look + + + align:start position:0% +you want it's something you want to look +at perhaps because it it may be a + + align:start position:0% +at perhaps because it it may be a + + + align:start position:0% +at perhaps because it it may be a +horseback way of thinking about + + align:start position:0% +horseback way of thinking about + + + align:start position:0% +horseback way of thinking about +risk right right after two years we're + + align:start position:0% +risk right right after two years we're + + + align:start position:0% +risk right right after two years we're +playing with house money because we've + + align:start position:0% +playing with house money because we've + + + align:start position:0% +playing with house money because we've +gotten our money back Andrew you have a + + align:start position:0% +gotten our money back Andrew you have a + + + align:start position:0% +gotten our money back Andrew you have a +comment I was going to ask I mean that I + + align:start position:0% +comment I was going to ask I mean that I + + + align:start position:0% +comment I was going to ask I mean that I +assume that even though it's not like + + align:start position:0% +assume that even though it's not like + + + align:start position:0% +assume that even though it's not like +the best metric to make the decision it + + align:start position:0% +the best metric to make the decision it + + + align:start position:0% +the best metric to make the decision it +could be a good metric to see like when + + align:start position:0% +could be a good metric to see like when + + + align:start position:0% +could be a good metric to see like when +your cash flows are coming in terms of + + align:start position:0% +your cash flows are coming in terms of + + + align:start position:0% +your cash flows are coming in terms of +like if I have something that has a + + align:start position:0% +like if I have something that has a + + + align:start position:0% +like if I have something that has a +payback period of Two and a payback de + + align:start position:0% +payback period of Two and a payback de + + + align:start position:0% +payback period of Two and a payback de +of 15 years I just know that uh like my + + align:start position:0% +of 15 years I just know that uh like my + + + align:start position:0% +of 15 years I just know that uh like my +risk is uh I have higher risk in terms + + align:start position:0% +risk is uh I have higher risk in terms + + + align:start position:0% +risk is uh I have higher risk in terms +of uh like when I get my money back with + + align:start position:0% +of uh like when I get my money back with + + + align:start position:0% +of uh like when I get my money back with +the second one no I think that's right + + align:start position:0% +the second one no I think that's right + + + align:start position:0% +the second one no I think that's right +but you you also want to just look at + + align:start position:0% +but you you also want to just look at + + + align:start position:0% +but you you also want to just look at +the nature of the risks if I tell you + + align:start position:0% +the nature of the risks if I tell you + + + align:start position:0% +the nature of the risks if I tell you +it's a + + align:start position:0% +it's a + + + align:start position:0% +it's a +bond and you don't worry about it if I + + align:start position:0% +bond and you don't worry about it if I + + + align:start position:0% +bond and you don't worry about it if I +tell you it's a nuclear plant okay the + + align:start position:0% +tell you it's a nuclear plant okay the + + + align:start position:0% +tell you it's a nuclear plant okay the +nuclear plant has a 20-year + + align:start position:0% +nuclear plant has a 20-year + + + align:start position:0% +nuclear plant has a 20-year +payback but if it runs for 40 years it's + + align:start position:0% +payback but if it runs for 40 years it's + + + align:start position:0% +payback but if it runs for 40 years it's +got a high Net Present Value you're + + align:start position:0% +got a high Net Present Value you're + + + align:start position:0% +got a high Net Present Value you're +right to say wait a minute an awful lot + + align:start position:0% +right to say wait a minute an awful lot + + + align:start position:0% +right to say wait a minute an awful lot +can happen see Germany see + + align:start position:0% +can happen see Germany see + + + align:start position:0% +can happen see Germany see +Japan uh so maybe I maybe I don't want + + align:start position:0% +Japan uh so maybe I maybe I don't want + + + align:start position:0% +Japan uh so maybe I maybe I don't want +to do that but that's that's sort of the + + align:start position:0% +to do that but that's that's sort of the + + + align:start position:0% +to do that but that's that's sort of the +main the main argument the internal rate + + align:start position:0% +main the main argument the internal rate + + + align:start position:0% +main the main argument the internal rate +of return turn is also sort of + + align:start position:0% +of return turn is also sort of + + + align:start position:0% +of return turn is also sort of +interesting okay you can think about the + + align:start position:0% +interesting okay you can think about the + + + align:start position:0% +interesting okay you can think about the +Net Present Value as a as a polom well + + align:start position:0% +Net Present Value as a as a polom well + + + align:start position:0% +Net Present Value as a as a polom well +it's a polinomial in 1 over 1+ + + align:start position:0% +it's a polinomial in 1 over 1+ + + + align:start position:0% +it's a polinomial in 1 over 1+ +R uh and you can say well + + align:start position:0% +R uh and you can say well + + + align:start position:0% +R uh and you can say well +suppose we doing this + + align:start position:0% +suppose we doing this + + + align:start position:0% +suppose we doing this +chocas suppose + + align:start position:0% + + + + align:start position:0% + +that this is the net present + + align:start position:0% + + + + align:start position:0% + +value and this is the discount rate then + + align:start position:0% +value and this is the discount rate then + + + align:start position:0% +value and this is the discount rate then +what you might expect is that as you if + + align:start position:0% +what you might expect is that as you if + + + align:start position:0% +what you might expect is that as you if +you if you make an upfront investment + + align:start position:0% +you if you make an upfront investment + + + align:start position:0% +you if you make an upfront investment +you get returns over time the higher the + + align:start position:0% +you get returns over time the higher the + + + align:start position:0% +you get returns over time the higher the +discount rate the lower the Net Present + + align:start position:0% +discount rate the lower the Net Present + + + align:start position:0% +discount rate the lower the Net Present +Value this point would + + align:start position:0% +Value this point would + + + align:start position:0% +Value this point would +be the internal rate of + + align:start position:0% +be the internal rate of + + + align:start position:0% +be the internal rate of +return now what's interesting about + + align:start position:0% +return now what's interesting about + + + align:start position:0% +return now what's interesting about +that is that when the picture looks like + + align:start position:0% +that is that when the picture looks like + + + align:start position:0% +that is that when the picture looks like +that you don't have to get too fussy + + align:start position:0% +that you don't have to get too fussy + + + align:start position:0% +that you don't have to get too fussy +about the discount rate as long as you + + align:start position:0% +about the discount rate as long as you + + + align:start position:0% +about the discount rate as long as you +know it's below our star right that's + + align:start position:0% +know it's below our star right that's + + + align:start position:0% +know it's below our star right that's +what it's good for it says well I know + + align:start position:0% +what it's good for it says well I know + + + align:start position:0% +what it's good for it says well I know +it's got a positive Net Present Value + + align:start position:0% +it's got a positive Net Present Value + + + align:start position:0% +it's got a positive Net Present Value +back + + align:start position:0% +back + + + align:start position:0% +back +here + + align:start position:0% +here + + + align:start position:0% +here +but so if if the discount rate somewhere + + align:start position:0% +but so if if the discount rate somewhere + + + align:start position:0% +but so if if the discount rate somewhere +in this range but I'm not sure which + + align:start position:0% +in this range but I'm not sure which + + + align:start position:0% +in this range but I'm not sure which +where it is I know enough to know the + + align:start position:0% +where it is I know enough to know the + + + align:start position:0% +where it is I know enough to know the +net present value is + + align:start position:0% +net present value is + + + align:start position:0% +net present value is +positive + + align:start position:0% +positive + + + align:start position:0% +positive +but you can have the graph could look + + align:start position:0% + + + + align:start position:0% + +it could look like + + align:start position:0% + + + + align:start position:0% + +that it could look like that if you know + + align:start position:0% +that it could look like that if you know + + + align:start position:0% +that it could look like that if you know +at the end of the period it is a nuclear + + align:start position:0% +at the end of the period it is a nuclear + + + align:start position:0% +at the end of the period it is a nuclear +reactor and we've got to clean it + + align:start position:0% +reactor and we've got to clean it + + + align:start position:0% +reactor and we've got to clean it +up okay then High discount rates make + + align:start position:0% +up okay then High discount rates make + + + align:start position:0% +up okay then High discount rates make +that cleanup cost smaller in present + + align:start position:0% +that cleanup cost smaller in present + + + align:start position:0% +that cleanup cost smaller in present +value + + align:start position:0% +value + + + align:start position:0% +value +terms right it's a polinomial so the + + align:start position:0% +terms right it's a polinomial so the + + + align:start position:0% +terms right it's a polinomial so the +number of sign changes is related in + + align:start position:0% +number of sign changes is related in + + + align:start position:0% +number of sign changes is related in +ways I've long since forgotten to the + + align:start position:0% +ways I've long since forgotten to the + + + align:start position:0% +ways I've long since forgotten to the +number of real + + align:start position:0% +number of real + + + align:start position:0% +number of real +Roots um + + align:start position:0% +Roots um + + + align:start position:0% +Roots um +if you have a if there's only one sign + + align:start position:0% +if you have a if there's only one sign + + + align:start position:0% +if you have a if there's only one sign +change you're only going to get one real + + align:start position:0% +change you're only going to get one real + + + align:start position:0% +change you're only going to get one real +root but if you have negative n negative + + align:start position:0% +root but if you have negative n negative + + + align:start position:0% +root but if you have negative n negative +returns at the end you can get two I + + align:start position:0% +returns at the end you can get two I + + + align:start position:0% +returns at the end you can get two I +suppose you can get more than two the + + align:start position:0% +suppose you can get more than two the + + + align:start position:0% +suppose you can get more than two the +normal thing and that's what the slide + + align:start position:0% +normal thing and that's what the slide + + + align:start position:0% +normal thing and that's what the slide +says is to call the smallest one R star + + align:start position:0% +says is to call the smallest one R star + + + align:start position:0% +says is to call the smallest one R star +and think that's a little + + align:start position:0% +and think that's a little + + + align:start position:0% +and think that's a little +weird the other thing to keep in + + align:start position:0% +weird the other thing to keep in + + + align:start position:0% +weird the other thing to keep in +mind again if you just graph these + + align:start position:0% + + + + align:start position:0% + +you can + + align:start position:0% +you can + + + align:start position:0% +you can +say here's project + + align:start position:0% + + + + align:start position:0% + +a here's Project + + align:start position:0% + + + + align:start position:0% + +B A has a higher internal rate of return + + align:start position:0% +B A has a higher internal rate of return + + + align:start position:0% +B A has a higher internal rate of return +than + + align:start position:0% + + + + align:start position:0% + +b but for discount rates back here you'd + + align:start position:0% +b but for discount rates back here you'd + + + align:start position:0% +b but for discount rates back here you'd +prefer + + align:start position:0% +prefer + + + align:start position:0% +prefer +B if you have to + + align:start position:0% +B if you have to + + + align:start position:0% +B if you have to +choose if you have limited funds they + + align:start position:0% +choose if you have limited funds they + + + align:start position:0% +choose if you have limited funds they +have the same upfront cost your discount + + align:start position:0% +have the same upfront cost your discount + + + align:start position:0% +have the same upfront cost your discount +rate is in here B has the higher Net + + align:start position:0% +rate is in here B has the higher Net + + + align:start position:0% +rate is in here B has the higher Net +Present Value you'd pick + + align:start position:0% +Present Value you'd pick + + + align:start position:0% +Present Value you'd pick +it so ranking by internal rate of return + + align:start position:0% +it so ranking by internal rate of return + + + align:start position:0% +it so ranking by internal rate of return +doesn't give you a desirability measure + + align:start position:0% +doesn't give you a desirability measure + + + align:start position:0% +doesn't give you a desirability measure +it just gives you some confidence + + align:start position:0% +it just gives you some confidence + + + align:start position:0% +it just gives you some confidence +about um + + align:start position:0% +about um + + + align:start position:0% +about um +uh it it allows you to be uncertain + + align:start position:0% +uh it it allows you to be uncertain + + + align:start position:0% +uh it it allows you to be uncertain +about the discount rate and still make a + + align:start position:0% +about the discount rate and still make a + + + align:start position:0% +about the discount rate and still make a +judgment about present + + align:start position:0% +judgment about present + + + align:start position:0% +judgment about present +value + + align:start position:0% +value + + + align:start position:0% +value +okay questions about those David + + align:start position:0% +okay questions about those David + + + align:start position:0% +okay questions about those David +so you just for + + align:start position:0% +so you just for + + + align:start position:0% +so you just for +Value + + align:start position:0% +Value + + + align:start position:0% +Value +no normally that's not that's how they + + align:start position:0% +no normally that's not that's how they + + + align:start position:0% +no normally that's not that's how they +do it this I don't worry about interest + + align:start position:0% +do it this I don't worry about interest + + + align:start position:0% +do it this I don't worry about interest +rates don't give me any of that fancy + + align:start position:0% +rates don't give me any of that fancy + + + align:start position:0% +rates don't give me any of that fancy +stuff when do I get my money + + align:start position:0% +stuff when do I get my money + + + align:start position:0% +stuff when do I get my money +out right and you could see the problem + + align:start position:0% +out right and you could see the problem + + + align:start position:0% +out right and you could see the problem +as I say I could give it to I can give + + align:start position:0% +as I say I could give it to I can give + + + align:start position:0% +as I say I could give it to I can give +you a one-year payback period That's a + + align:start position:0% +you a one-year payback period That's a + + + align:start position:0% +you a one-year payback period That's a +lousy investment that's pretty easy give + + align:start position:0% +lousy investment that's pretty easy give + + + align:start position:0% +lousy investment that's pretty easy give +me $100 today I'll give it back to you + + align:start position:0% +me $100 today I'll give it back to you + + + align:start position:0% +me $100 today I'll give it back to you +in a year one year payback fabulous H + + align:start position:0% +in a year one year payback fabulous H + + + align:start position:0% +in a year one year payback fabulous H +not a good idea so it's a uh + + align:start position:0% +not a good idea so it's a uh + + + align:start position:0% +not a good idea so it's a uh +I it's hard to imagine but but you can + + align:start position:0% +I it's hard to imagine but but you can + + + align:start position:0% +I it's hard to imagine but but you can +read texts in the 50s that are debating + + align:start position:0% +read texts in the 50s that are debating + + + align:start position:0% +read texts in the 50s that are debating +the merits of payback versus Net Present + + align:start position:0% +the merits of payback versus Net Present + + + align:start position:0% +the merits of payback versus Net Present +Value and you say wait what how anyway + + align:start position:0% +Value and you say wait what how anyway + + + align:start position:0% +Value and you say wait what how anyway +okay what I want to do unless there are + + align:start position:0% +okay what I want to do unless there are + + + align:start position:0% +okay what I want to do unless there are +questions about any of this or general + + align:start position:0% +questions about any of this or general + + + align:start position:0% +questions about any of this or general +questions about combined heat and power + + align:start position:0% +questions about combined heat and power + + + align:start position:0% +questions about combined heat and power +I want to go to the + + align:start position:0% +I want to go to the + + + align:start position:0% +I want to go to the +spreadsheet um H it I it didn't occur to + + align:start position:0% +spreadsheet um H it I it didn't occur to + + + align:start position:0% +spreadsheet um H it I it didn't occur to +me to ask because of course this is MIT + + align:start position:0% +me to ask because of course this is MIT + + + align:start position:0% +me to ask because of course this is MIT +but how many of you have played with e + + align:start position:0% +but how many of you have played with e + + + align:start position:0% +but how many of you have played with e +Excel + + align:start position:0% +Excel + + + align:start position:0% +Excel +before oh good that's what I thought + + align:start position:0% +before oh good that's what I thought + + + align:start position:0% +before oh good that's what I thought +I feel so much better all right let's go + + align:start position:0% + + + + align:start position:0% + +there that Accords with my priors + + align:start position:0% +there that Accords with my priors + + + align:start position:0% +there that Accords with my priors +but all right so there we have there we + + align:start position:0% +but all right so there we have there we + + + align:start position:0% +but all right so there we have there we +have the spreadsheet is that readable + + align:start position:0% +have the spreadsheet is that readable + + + align:start position:0% +have the spreadsheet is that readable +more or less in the + + align:start position:0% +more or less in the + + + align:start position:0% +more or less in the +back + + align:start position:0% +back + + + align:start position:0% +back +okay and let's let's walk through a set + + align:start position:0% +okay and let's let's walk through a set + + + align:start position:0% +okay and let's let's walk through a set +of + + align:start position:0% +of + + + align:start position:0% +of +questions let's figure out how to walk + + align:start position:0% +questions let's figure out how to walk + + + align:start position:0% +questions let's figure out how to walk +through a set of questions irum What's + + align:start position:0% +through a set of questions irum What's + + + align:start position:0% +through a set of questions irum What's +Happening Here turn the side screen + + align:start position:0% +Happening Here turn the side screen + + + align:start position:0% +Happening Here turn the side screen +on that's what you got to do turn the + + align:start position:0% +on that's what you got to do turn the + + + align:start position:0% +on that's what you got to do turn the +side screen + + align:start position:0% +side screen + + + align:start position:0% +side screen +on all + + align:start position:0% + + + + align:start position:0% + +right + + align:start position:0% + + + + align:start position:0% + +no + + align:start position:0% +no + + + align:start position:0% +no +Tada all right this works Let Die thank + + align:start position:0% +Tada all right this works Let Die thank + + + align:start position:0% +Tada all right this works Let Die thank +you um if you walk through + + align:start position:0% +you um if you walk through + + + align:start position:0% +you um if you walk through +this this this illustrates my point + + align:start position:0% +this this this illustrates my point + + + align:start position:0% +this this this illustrates my point +about + + align:start position:0% + + + + align:start position:0% + +depreciation you get total + + align:start position:0% +depreciation you get total + + + align:start position:0% +depreciation you get total +savings total expenses gross margin that + + align:start position:0% +savings total expenses gross margin that + + + align:start position:0% +savings total expenses gross margin that +is to say what does this thing throw off + + align:start position:0% +is to say what does this thing throw off + + + align:start position:0% +is to say what does this thing throw off +in terms of total savings per + + align:start position:0% +in terms of total savings per + + + align:start position:0% +in terms of total savings per +year you can subtract depreciation and + + align:start position:0% +year you can subtract depreciation and + + + align:start position:0% +year you can subtract depreciation and +get earnings before taxes if you want to + + align:start position:0% +get earnings before taxes if you want to + + + align:start position:0% +get earnings before taxes if you want to +but then you'll notice what + + align:start position:0% + + + + align:start position:0% + +happens they compute taxes and they add + + align:start position:0% +happens they compute taxes and they add + + + align:start position:0% +happens they compute taxes and they add +back depreciation right it appears here + + align:start position:0% +back depreciation right it appears here + + + align:start position:0% +back depreciation right it appears here +and it appears + + align:start position:0% +and it appears + + + align:start position:0% +and it appears +there depreciation is a game you and + + align:start position:0% +there depreciation is a game you and + + + align:start position:0% +there depreciation is a game you and +your accountant play with the tax + + align:start position:0% +your accountant play with the tax + + + align:start position:0% +your accountant play with the tax +people so when calculating the after tax + + align:start position:0% +people so when calculating the after tax + + + align:start position:0% +people so when calculating the after tax +in your pocket savings you have to say + + align:start position:0% +in your pocket savings you have to say + + + align:start position:0% +in your pocket savings you have to say +what depreciation do I get to take how + + align:start position:0% +what depreciation do I get to take how + + + align:start position:0% +what depreciation do I get to take how +does that affect my + + align:start position:0% +does that affect my + + + align:start position:0% +does that affect my +taxes that's it that's it if you get + + align:start position:0% +taxes that's it that's it if you get + + + align:start position:0% +taxes that's it that's it if you get +faster depreciation your income is lower + + align:start position:0% +faster depreciation your income is lower + + + align:start position:0% +faster depreciation your income is lower +and your taxes are lower your income + + align:start position:0% +and your taxes are lower your income + + + align:start position:0% +and your taxes are lower your income +being lower doesn't matter your taxes + + align:start position:0% +being lower doesn't matter your taxes + + + align:start position:0% +being lower doesn't matter your taxes +being lower + + align:start position:0% +being lower + + + align:start position:0% +being lower +does is that reasonably straightforward + + align:start position:0% +does is that reasonably straightforward + + + align:start position:0% +does is that reasonably straightforward +because you're going to see this in + + align:start position:0% +because you're going to see this in + + + align:start position:0% +because you're going to see this in +later life I'll guarantee you and it + + align:start position:0% +later life I'll guarantee you and it + + + align:start position:0% +later life I'll guarantee you and it +shouldn't be mysterious it really is and + + align:start position:0% +shouldn't be mysterious it really is and + + + align:start position:0% +shouldn't be mysterious it really is and +it's it's an accounting entity you + + align:start position:0% +it's it's an accounting entity you + + + align:start position:0% +it's it's an accounting entity you +report it on taxes some companies use + + align:start position:0% +report it on taxes some companies use + + + align:start position:0% +report it on taxes some companies use +different depreciation schedules for + + align:start position:0% +different depreciation schedules for + + + align:start position:0% +different depreciation schedules for +taxes than for financial + + align:start position:0% +taxes than for financial + + + align:start position:0% +taxes than for financial +reporting which you're allowed to do to + + align:start position:0% +reporting which you're allowed to do to + + + align:start position:0% +reporting which you're allowed to do to +some + + align:start position:0% +some + + + align:start position:0% +some +extent okay + + align:start position:0% +extent okay + + + align:start position:0% +extent okay +question I talked before about the + + align:start position:0% +question I talked before about the + + + align:start position:0% +question I talked before about the +difference between doing things in real + + align:start position:0% +difference between doing things in real + + + align:start position:0% +difference between doing things in real +terms and doing things in nominal + + align:start position:0% +terms and doing things in nominal + + + align:start position:0% +terms and doing things in nominal +terms which is Dar assuming this is + + align:start position:0% +terms which is Dar assuming this is + + + align:start position:0% +terms which is Dar assuming this is +Darren and not not some um Sloan student + + align:start position:0% +Darren and not not some um Sloan student + + + align:start position:0% +Darren and not not some um Sloan student +who wrote up the case um what's Darren + + align:start position:0% +who wrote up the case um what's Darren + + + align:start position:0% +who wrote up the case um what's Darren +doing is this a real analysis a nominal + + align:start position:0% +doing is this a real analysis a nominal + + + align:start position:0% +doing is this a real analysis a nominal +analysis is he + + align:start position:0% +analysis is he + + + align:start position:0% +analysis is he +confused G what do you + + align:start position:0% + + + + align:start position:0% + +think I'm confused huh I'm confused + + align:start position:0% +think I'm confused huh I'm confused + + + align:start position:0% +think I'm confused huh I'm confused +you're confused okay okay say + + align:start position:0% +you're confused okay okay say + + + align:start position:0% +you're confused okay okay say +why + + align:start position:0% + + + + align:start position:0% + +um I don't exactly understand like + + align:start position:0% +um I don't exactly understand like + + + align:start position:0% +um I don't exactly understand like +how like I would characterize + + align:start position:0% +how like I would characterize + + + align:start position:0% +how like I would characterize +depreciation as nomal real oh what I + + align:start position:0% +depreciation as nomal real oh what I + + + align:start position:0% +depreciation as nomal real oh what I +don't understand how I will like + + align:start position:0% +don't understand how I will like + + + align:start position:0% +don't understand how I will like +characterize it as either nominal real + + align:start position:0% +characterize it as either nominal real + + + align:start position:0% +characterize it as either nominal real +or + + align:start position:0% +or + + + align:start position:0% +or +inconsistent like is this the nominal + + align:start position:0% +inconsistent like is this the nominal + + + align:start position:0% +inconsistent like is this the nominal +like what things should be or nominal + + align:start position:0% +like what things should be or nominal + + + align:start position:0% +like what things should be or nominal +like like interest rate well what I said + + align:start position:0% +like like interest rate well what I said + + + align:start position:0% +like like interest rate well what I said +last time was if you want to assume that + + align:start position:0% +last time was if you want to assume that + + + align:start position:0% +last time was if you want to assume that +prices don't change in this + + align:start position:0% +prices don't change in this + + + align:start position:0% +prices don't change in this +world um where prices do change then + + align:start position:0% +world um where prices do change then + + + align:start position:0% +world um where prices do change then +you'd better use a real discount rate + + align:start position:0% +you'd better use a real discount rate + + + align:start position:0% +you'd better use a real discount rate +that measures purchasing power if you + + align:start position:0% +that measures purchasing power if you + + + align:start position:0% +that measures purchasing power if you +want to use the kind of rates you see in + + align:start position:0% +want to use the kind of rates you see in + + + align:start position:0% +want to use the kind of rates you see in +the market those rates are based on + + align:start position:0% +the market those rates are based on + + + align:start position:0% +the market those rates are based on +people's expectations about inflation so + + align:start position:0% +people's expectations about inflation so + + + align:start position:0% +people's expectations about inflation so +you'd better build in expectations about + + align:start position:0% +you'd better build in expectations about + + + align:start position:0% +you'd better build in expectations about +inflation what people often do and it's + + align:start position:0% +inflation what people often do and it's + + + align:start position:0% +inflation what people often do and it's +a mistake is to use discount rates or + + align:start position:0% +a mistake is to use discount rates or + + + align:start position:0% +a mistake is to use discount rates or +interest rates from the market and + + align:start position:0% +interest rates from the market and + + + align:start position:0% +interest rates from the market and +assume prices don't + + align:start position:0% +assume prices don't + + + align:start position:0% +assume prices don't +change so is he inconsistent like that + + align:start position:0% +change so is he inconsistent like that + + + align:start position:0% +change so is he inconsistent like that +or is he + + align:start position:0% +or is he + + + align:start position:0% +or is he +consistent I give you a hint a 10% real + + align:start position:0% +consistent I give you a hint a 10% real + + + align:start position:0% +consistent I give you a hint a 10% real +rate would be + + align:start position:0% +rate would be + + + align:start position:0% +rate would be +amazing that would be very very + + align:start position:0% + + + + align:start position:0% + +high not amazing it would be + + align:start position:0% +high not amazing it would be + + + align:start position:0% +high not amazing it would be +High + + align:start position:0% +High + + + align:start position:0% +High +maora um I mean from what you just said + + align:start position:0% +maora um I mean from what you just said + + + align:start position:0% +maora um I mean from what you just said +she's doing nominal analysis doing a + + align:start position:0% +she's doing nominal analysis doing a + + + align:start position:0% +she's doing nominal analysis doing a +nominal analysis yeah cuz he he builds + + align:start position:0% +nominal analysis yeah cuz he he builds + + + align:start position:0% +nominal analysis yeah cuz he he builds +in he has + + align:start position:0% +in he has + + + align:start position:0% +in he has +explicit + + align:start position:0% +explicit + + + align:start position:0% +explicit +assumptions about it about + + align:start position:0% +assumptions about it about + + + align:start position:0% +assumptions about it about +inflation and he's got an interest rate + + align:start position:0% +inflation and he's got an interest rate + + + align:start position:0% +inflation and he's got an interest rate +that's 2003 that's a pretty that's a + + align:start position:0% +that's 2003 that's a pretty that's a + + + align:start position:0% +that's 2003 that's a pretty that's a +market rate in 2003 no reason you would + + align:start position:0% +market rate in 2003 no reason you would + + + align:start position:0% +market rate in 2003 no reason you would +know that but you see the you see the + + align:start position:0% +know that but you see the you see the + + + align:start position:0% +know that but you see the you see the +explicit inflation numbers and a fairly + + align:start position:0% +explicit inflation numbers and a fairly + + + align:start position:0% +explicit inflation numbers and a fairly +High interest rate so he's doing a + + align:start position:0% +High interest rate so he's doing a + + + align:start position:0% +High interest rate so he's doing a +nominal analysis it looks consistent + + align:start position:0% + + + + align:start position:0% + +um is there any defense in the + + align:start position:0% +um is there any defense in the + + + align:start position:0% +um is there any defense in the +spreadsheet or in the case as to the + + align:start position:0% +spreadsheet or in the case as to the + + + align:start position:0% +spreadsheet or in the case as to the +choice of discount + + align:start position:0% + + + + align:start position:0% + +rate Sarah I don't remember there being + + align:start position:0% +rate Sarah I don't remember there being + + + align:start position:0% +rate Sarah I don't remember there being +a very specific one but I would assume + + align:start position:0% +a very specific one but I would assume + + + align:start position:0% +a very specific one but I would assume +comparable risky assets on the market + + align:start position:0% +comparable risky assets on the market + + + align:start position:0% +comparable risky assets on the market +yeah he didn't say it though there's no + + align:start position:0% +yeah he didn't say it though there's no + + + align:start position:0% +yeah he didn't say it though there's no +discussion of where that 10% came from + + align:start position:0% +discussion of where that 10% came from + + + align:start position:0% +discussion of where that 10% came from +after all of that in comprehensible + + align:start position:0% +after all of that in comprehensible + + + align:start position:0% +after all of that in comprehensible +nonsense last time about beta uh I was + + align:start position:0% +nonsense last time about beta uh I was + + + align:start position:0% +nonsense last time about beta uh I was +giving you what you ought to do not what + + align:start position:0% +giving you what you ought to do not what + + + align:start position:0% +giving you what you ought to do not what +people often do and clearly what he did + + align:start position:0% +people often do and clearly what he did + + + align:start position:0% +people often do and clearly what he did +here was to take kind of a horseback + + align:start position:0% +here was to take kind of a horseback + + + align:start position:0% +here was to take kind of a horseback +reasonable rate and say at 10% that's + + align:start position:0% +reasonable rate and say at 10% that's + + + align:start position:0% +reasonable rate and say at 10% that's +pretty pretty much in line with cost of + + align:start position:0% +pretty pretty much in line with cost of + + + align:start position:0% +pretty pretty much in line with cost of +capital you see and discount rates you + + align:start position:0% +capital you see and discount rates you + + + align:start position:0% +capital you see and discount rates you +see you would like him to have done more + + align:start position:0% +see you would like him to have done more + + + align:start position:0% +see you would like him to have done more +this is not necessarily an ideal + + align:start position:0% +this is not necessarily an ideal + + + align:start position:0% +this is not necessarily an ideal +are the inflation assumptions + + align:start position:0% + + + + align:start position:0% + +reasonable anybody react to those what + + align:start position:0% +reasonable anybody react to those what + + + align:start position:0% +reasonable anybody react to those what +do you think 2% electricity 2% + + align:start position:0% +do you think 2% electricity 2% + + + align:start position:0% +do you think 2% electricity 2% +maintenance 2% chemicals to be added to + + align:start position:0% +maintenance 2% chemicals to be added to + + + align:start position:0% +maintenance 2% chemicals to be added to +the + + align:start position:0% + + + + align:start position:0% + +water I haven't been looking at interest + + align:start position:0% +water I haven't been looking at interest + + + align:start position:0% +water I haven't been looking at interest +rates on a yearly basis so I don't know + + align:start position:0% +rates on a yearly basis so I don't know + + + align:start position:0% +rates on a yearly basis so I don't know +what to compare it to I'm + + align:start position:0% +what to compare it to I'm + + + align:start position:0% +what to compare it to I'm +shocked shocked I that's what people + + align:start position:0% +shocked shocked I that's what people + + + align:start position:0% +shocked shocked I that's what people +around here did I certainly do + + align:start position:0% +around here did I certainly do + + + align:start position:0% +around here did I certainly do +um I + + align:start position:0% +um I + + + align:start position:0% +um I +mean these are not implausible numbers + + align:start position:0% +mean these are not implausible numbers + + + align:start position:0% +mean these are not implausible numbers +right I mean if you look historically at + + align:start position:0% +right I mean if you look historically at + + + align:start position:0% +right I mean if you look historically at +inflation rates they run in this country + + align:start position:0% +inflation rates they run in this country + + + align:start position:0% +inflation rates they run in this country +one one two two and a half percent so 2% + + align:start position:0% +one one two two and a half percent so 2% + + + align:start position:0% +one one two two and a half percent so 2% +is reasonable what you don't see in this + + align:start position:0% +is reasonable what you don't see in this + + + align:start position:0% +is reasonable what you don't see in this +spreadsheet what you might like to see + + align:start position:0% +spreadsheet what you might like to see + + + align:start position:0% +spreadsheet what you might like to see +in life is you might like to see well + + align:start position:0% +in life is you might like to see well + + + align:start position:0% +in life is you might like to see well +does the choice of discount rate matter + + align:start position:0% +does the choice of discount rate matter + + + align:start position:0% +does the choice of discount rate matter +you could check easily enough we could + + align:start position:0% +you could check easily enough we could + + + align:start position:0% +you could check easily enough we could +put another rate in uh do the inflation + + align:start position:0% +put another rate in uh do the inflation + + + align:start position:0% +put another rate in uh do the inflation +assumptions + + align:start position:0% +assumptions + + + align:start position:0% +assumptions +matter uh are these is the outcome + + align:start position:0% +matter uh are these is the outcome + + + align:start position:0% +matter uh are these is the outcome +sensitive to these things that don't get + + align:start position:0% +sensitive to these things that don't get + + + align:start position:0% +sensitive to these things that don't get +defended + + align:start position:0% +defended + + + align:start position:0% +defended +much that would be if you were doing + + align:start position:0% +much that would be if you were doing + + + align:start position:0% +much that would be if you were doing +this for real and it was your money + + align:start position:0% +this for real and it was your money + + + align:start position:0% +this for real and it was your money +you'd want to do that you'd want to say + + align:start position:0% +you'd want to do that you'd want to say + + + align:start position:0% +you'd want to do that you'd want to say +okay I'm not too sure about those + + align:start position:0% +okay I'm not too sure about those + + + align:start position:0% +okay I'm not too sure about those +assumptions are they critical do they + + align:start position:0% +assumptions are they critical do they + + + align:start position:0% +assumptions are they critical do they +drive the answer if they do you'd want + + align:start position:0% +drive the answer if they do you'd want + + + align:start position:0% +drive the answer if they do you'd want +to look harder we don't see any of that + + align:start position:0% +to look harder we don't see any of that + + + align:start position:0% +to look harder we don't see any of that +we may be missing a dozen spreadsheets + + align:start position:0% +we may be missing a dozen spreadsheets + + + align:start position:0% +we may be missing a dozen spreadsheets +in the background but we don't see it + + align:start position:0% +in the background but we don't see it + + + align:start position:0% +in the background but we don't see it +here okay as you read the + + align:start position:0% + + + + align:start position:0% + +case where are there risks on this + + align:start position:0% + + + + align:start position:0% + +sheet + + align:start position:0% +sheet + + + align:start position:0% +sheet +Jorge anything here that's not + + align:start position:0% + + + + align:start position:0% + +certain you think it's all pretty Rock + + align:start position:0% +certain you think it's all pretty Rock + + + align:start position:0% +certain you think it's all pretty Rock +solid Matthew I think something that we + + align:start position:0% +solid Matthew I think something that we + + + align:start position:0% +solid Matthew I think something that we +didn't really bring it up he said that + + align:start position:0% +didn't really bring it up he said that + + + align:start position:0% +didn't really bring it up he said that +the + + align:start position:0% +the + + + align:start position:0% +the +company that time took much longer or + + align:start position:0% +company that time took much longer or + + + align:start position:0% +company that time took much longer or +even like a day longer production would + + align:start position:0% +even like a day longer production would + + + align:start position:0% +even like a day longer production would +set + + align:start position:0% +set + + + align:start position:0% +set +back offset of the cost year yeah we + + align:start position:0% +back offset of the cost year yeah we + + + align:start position:0% +back offset of the cost year yeah we +don't see the Lost production here uh + + align:start position:0% +don't see the Lost production here uh + + + align:start position:0% +don't see the Lost production here uh +and there is presumably some risk + + align:start position:0% +and there is presumably some risk + + + align:start position:0% +and there is presumably some risk +there what about and that's related to + + align:start position:0% +there what about and that's related to + + + align:start position:0% +there what about and that's related to +the installation + + align:start position:0% +the installation + + + align:start position:0% +the installation +cost for which we have only an estimate + + align:start position:0% +cost for which we have only an estimate + + + align:start position:0% +cost for which we have only an estimate +right we don't have a guarantee + + align:start position:0% +right we don't have a guarantee + + + align:start position:0% +right we don't have a guarantee +Rachel I guess the thing that kind jump + + align:start position:0% +Rachel I guess the thing that kind jump + + + align:start position:0% +Rachel I guess the thing that kind jump +out to me was assuming that they could + + align:start position:0% +out to me was assuming that they could + + + align:start position:0% +out to me was assuming that they could +get that yeah because a lot + + align:start position:0% + + + + align:start position:0% + +of yeah I thought that was that was + + align:start position:0% +of yeah I thought that was that was + + + align:start position:0% +of yeah I thought that was that was +pretty bold to say well I know the the + + align:start position:0% +pretty bold to say well I know the the + + + align:start position:0% +pretty bold to say well I know the the +text says we're pretty sure we can get + + align:start position:0% +text says we're pretty sure we can get + + + align:start position:0% +text says we're pretty sure we can get +this match in Grant for + + align:start position:0% +this match in Grant for + + + align:start position:0% +this match in Grant for +1725 so we'll just assume we get + + align:start position:0% +1725 so we'll just assume we get + + + align:start position:0% +1725 so we'll just assume we get +it and there's no lost production in + + align:start position:0% +it and there's no lost production in + + + align:start position:0% +it and there's no lost production in +here sharing I think during during that + + align:start position:0% +here sharing I think during during that + + + align:start position:0% +here sharing I think during during that +time was much more reasonable inorder to + + align:start position:0% +time was much more reasonable inorder to + + + align:start position:0% +time was much more reasonable inorder to +get the CR I think nowaday might be much + + align:start position:0% +get the CR I think nowaday might be much + + + align:start position:0% +get the CR I think nowaday might be much +more difficult after the financial + + align:start position:0% +more difficult after the financial + + + align:start position:0% +more difficult after the financial +crisis but before then the period kind + + align:start position:0% +crisis but before then the period kind + + + align:start position:0% +crisis but before then the period kind +of leading up to 2007 it wasn't very + + align:start position:0% +of leading up to 2007 it wasn't very + + + align:start position:0% +of leading up to 2007 it wasn't very +difficult for like + + align:start position:0% +difficult for like + + + align:start position:0% +difficult for like +that's I mean comparably if you I think + + align:start position:0% +that's I mean comparably if you I think + + + align:start position:0% +that's I mean comparably if you I think +sure that it's probably fair for + + align:start position:0% +sure that it's probably fair for + + + align:start position:0% +sure that it's probably fair for +nowadays but not necessarily the case + + align:start position:0% +nowadays but not necessarily the case + + + align:start position:0% +nowadays but not necessarily the case +back then if I were a naysayer I'd say + + align:start position:0% +back then if I were a naysayer I'd say + + + align:start position:0% +back then if I were a naysayer I'd say +do you have that in + + align:start position:0% +do you have that in + + + align:start position:0% +do you have that in +writing do you have that Grant that's + + align:start position:0% +writing do you have that Grant that's + + + align:start position:0% +writing do you have that Grant that's +that's that's big relative to the to the + + align:start position:0% +that's that's big relative to the to the + + + align:start position:0% +that's that's big relative to the to the +whole upfront cost and he didn't he + + align:start position:0% +whole upfront cost and he didn't he + + + align:start position:0% +whole upfront cost and he didn't he +didn't quite mention that yeah really I + + align:start position:0% +didn't quite mention that yeah really I + + + align:start position:0% +didn't quite mention that yeah really I +mean companies like Tesla and viscar + + align:start position:0% +mean companies like Tesla and viscar + + + align:start position:0% +mean companies like Tesla and viscar +Karma got like half a billion dollar + + align:start position:0% +Karma got like half a billion dollar + + + align:start position:0% +Karma got like half a billion dollar +loans for their + + align:start position:0% +loans for their + + + align:start position:0% +loans for their +projects yeah but he this is a New York + + align:start position:0% +projects yeah but he this is a New York + + + align:start position:0% +projects yeah but he this is a New York +state I don't know this program or I + + align:start position:0% +state I don't know this program or I + + + align:start position:0% +state I don't know this program or I +certainly don't what this program looked + + align:start position:0% +certainly don't what this program looked + + + align:start position:0% +certainly don't what this program looked +like in 2003 all I know is that the case + + align:start position:0% +like in 2003 all I know is that the case + + + align:start position:0% +like in 2003 all I know is that the case +said can probably get the + + align:start position:0% +said can probably get the + + + align:start position:0% +said can probably get the +Grant I I I would say gee I'd really + + align:start position:0% +Grant I I I would say gee I'd really + + + align:start position:0% +Grant I I I would say gee I'd really +like to know how does this look without + + align:start position:0% +like to know how does this look without + + + align:start position:0% +like to know how does this look without +getting the + + align:start position:0% +getting the + + + align:start position:0% +getting the +grant um I mean do we know we're going + + align:start position:0% +grant um I mean do we know we're going + + + align:start position:0% +grant um I mean do we know we're going +to get it + + align:start position:0% +to get it + + + align:start position:0% +to get it +suppose installation in fact the + + align:start position:0% +suppose installation in fact the + + + align:start position:0% +suppose installation in fact the +installation + + align:start position:0% +installation + + + align:start position:0% +installation +cost didn't they say 120 125 and he said + + align:start position:0% +cost didn't they say 120 125 and he said + + + align:start position:0% +cost didn't they say 120 125 and he said +I think we can get it down to + + align:start position:0% +I think we can get it down to + + + align:start position:0% +I think we can get it down to +100 isn't that right yeah thank you I + + align:start position:0% +100 isn't that right yeah thank you I + + + align:start position:0% +100 isn't that right yeah thank you I +need support + + align:start position:0% +need support + + + align:start position:0% +need support +um so this + + align:start position:0% + + + + align:start position:0% + +is so we I anything else that's + + align:start position:0% +is so we I anything else that's + + + align:start position:0% +is so we I anything else that's +uncertain here that you might want to + + align:start position:0% +uncertain here that you might want to + + + align:start position:0% +uncertain here that you might want to +focus on + + align:start position:0% +focus on + + + align:start position:0% +focus on +Julian I don't see any removal cost on + + align:start position:0% +Julian I don't see any removal cost on + + + align:start position:0% +Julian I don't see any removal cost on +there like removal cost you mean when + + align:start position:0% +there like removal cost you mean when + + + align:start position:0% +there like removal cost you mean when +when you scrap it at the end yeah uh + + align:start position:0% +when you scrap it at the end yeah uh + + + align:start position:0% +when you scrap it at the end yeah uh +that's a good good point that's a good + + align:start position:0% +that's a good good point that's a good + + + align:start position:0% +that's a good good point that's a good +point he doesn't talk about he runs it + + align:start position:0% +point he doesn't talk about he runs it + + + align:start position:0% +point he doesn't talk about he runs it +out for I forget how long this + + align:start position:0% +out for I forget how long this + + + align:start position:0% +out for I forget how long this +spreadsheet runs uh but he + + align:start position:0% +spreadsheet runs uh but he + + + align:start position:0% +spreadsheet runs uh but he +doesn't he didn't talk about what you + + align:start position:0% +doesn't he didn't talk about what you + + + align:start position:0% +doesn't he didn't talk about what you +presumably you + + align:start position:0% +presumably you + + + align:start position:0% +presumably you +wouldn't presumably you wouldn't throw + + align:start position:0% +wouldn't presumably you wouldn't throw + + + align:start position:0% +wouldn't presumably you wouldn't throw +it all away since some of it's pipe well + + align:start position:0% +it all away since some of it's pipe well + + + align:start position:0% +it all away since some of it's pipe well +maybe you would I mean it's pipe with + + align:start position:0% +maybe you would I mean it's pipe with + + + align:start position:0% +maybe you would I mean it's pipe with +water so it shouldn't be it should last + + align:start position:0% +water so it shouldn't be it should last + + + align:start position:0% +water so it shouldn't be it should last +pretty well but you but the generator + + align:start position:0% +pretty well but you but the generator + + + align:start position:0% +pretty well but you but the generator +you'd have to replace and the turbine + + align:start position:0% +you'd have to replace and the turbine + + + align:start position:0% +you'd have to replace and the turbine +you'd have to replace after a while + + align:start position:0% +you'd have to replace after a while + + + align:start position:0% +you'd have to replace after a while +you're right there's none of that but I + + align:start position:0% +you're right there's none of that but I + + + align:start position:0% +you're right there's none of that but I +guess you could think about + + align:start position:0% +guess you could think about + + + align:start position:0% +guess you could think about +well the question is is there a disposal + + align:start position:0% +well the question is is there a disposal + + + align:start position:0% +well the question is is there a disposal +cost yeah the question isn't would you + + align:start position:0% +cost yeah the question isn't would you + + + align:start position:0% +cost yeah the question isn't would you +have to replace it because you probably + + align:start position:0% +have to replace it because you probably + + + align:start position:0% +have to replace it because you probably +would the question is should there be a + + align:start position:0% +would the question is should there be a + + + align:start position:0% +would the question is should there be a +negative number at the end or could you + + align:start position:0% +negative number at the end or could you + + + align:start position:0% +negative number at the end or could you +sell it for + + align:start position:0% +sell it for + + + align:start position:0% +sell it for +scrap and he didn't mention that + + align:start position:0% +scrap and he didn't mention that + + + align:start position:0% +scrap and he didn't mention that +anything + + align:start position:0% +anything + + + align:start position:0% +anything +else + + align:start position:0% +else + + + align:start position:0% +else +okay do you like his treatment of these + + align:start position:0% +okay do you like his treatment of these + + + align:start position:0% +okay do you like his treatment of these +risks Darren is not our favorite person + + align:start position:0% +risks Darren is not our favorite person + + + align:start position:0% +risks Darren is not our favorite person +here yes well the the thing is we since + + align:start position:0% +here yes well the the thing is we since + + + align:start position:0% +here yes well the the thing is we since +we don't know exactly how he came up + + align:start position:0% +we don't know exactly how he came up + + + align:start position:0% +we don't know exactly how he came up +with that discount rate uh there's a + + align:start position:0% +with that discount rate uh there's a + + + align:start position:0% +with that discount rate uh there's a +possibility that he's not really + + align:start position:0% +possibility that he's not really + + + align:start position:0% +possibility that he's not really +accounting for the risk and the cash + + align:start position:0% +accounting for the risk and the cash + + + align:start position:0% +accounting for the risk and the cash +flows he might just I mean the discount + + align:start position:0% +flows he might just I mean the discount + + + align:start position:0% +flows he might just I mean the discount +rate is barely it's not it's kind of low + + align:start position:0% +rate is barely it's not it's kind of low + + + align:start position:0% +rate is barely it's not it's kind of low +but maybe he he's he took that into + + align:start position:0% +but maybe he he's he took that into + + + align:start position:0% +but maybe he he's he took that into +account when calculating the the you + + align:start position:0% +account when calculating the the you + + + align:start position:0% +account when calculating the the you +know risk premium uh associated with uh + + align:start position:0% +know risk premium uh associated with uh + + + align:start position:0% +know risk premium uh associated with uh +his discount rate so + + align:start position:0% +his discount rate so + + + align:start position:0% +his discount rate so +maybe but is this my next question + + align:start position:0% + + + + align:start position:0% + +yes did he use pessimistic figures + + align:start position:0% +yes did he use pessimistic figures + + + align:start position:0% +yes did he use pessimistic figures +optimistic figures or more or less + + align:start position:0% +optimistic figures or more or less + + + align:start position:0% +optimistic figures or more or less +middle of the road + + align:start position:0% +middle of the road + + + align:start position:0% +middle of the road +figures pretty optimistic huh yeah Chad + + align:start position:0% +figures pretty optimistic huh yeah Chad + + + align:start position:0% +figures pretty optimistic huh yeah Chad +you agree optimistic + + align:start position:0% +you agree optimistic + + + align:start position:0% +you agree optimistic +okay uh that's + + align:start position:0% + + + + align:start position:0% + +a it's an + + align:start position:0% +a it's an + + + align:start position:0% +a it's an +interesting it's an interesting + + align:start position:0% +interesting it's an interesting + + + align:start position:0% +interesting it's an interesting +presentational choice right cuz Darren + + align:start position:0% +presentational choice right cuz Darren + + + align:start position:0% +presentational choice right cuz Darren +knows all of + + align:start position:0% +knows all of + + + align:start position:0% +knows all of +this and Darren could just say well yeah + + align:start position:0% +this and Darren could just say well yeah + + + align:start position:0% +this and Darren could just say well yeah +I've been a little optimistic but the + + align:start position:0% +I've been a little optimistic but the + + + align:start position:0% +I've been a little optimistic but the +10% is + + align:start position:0% +10% is + + + align:start position:0% +10% is +High + + align:start position:0% + + + + align:start position:0% + +um this project looks so good on his + + align:start position:0% +um this project looks so good on his + + + align:start position:0% +um this project looks so good on his +numbers that the better strategy would + + align:start position:0% +numbers that the better strategy would + + + align:start position:0% +numbers that the better strategy would +be to be + + align:start position:0% +be to be + + + align:start position:0% +be to be +pessimistic so you can say look I mean I + + align:start position:0% +pessimistic so you can say look I mean I + + + align:start position:0% +pessimistic so you can say look I mean I +was very pessimistic and it still looked + + align:start position:0% +was very pessimistic and it still looked + + + align:start position:0% +was very pessimistic and it still looked +good he didn't do that uh or he didn't + + align:start position:0% +good he didn't do that uh or he didn't + + + align:start position:0% +good he didn't do that uh or he didn't +explore again if somebody shows you one + + align:start position:0% +explore again if somebody shows you one + + + align:start position:0% +explore again if somebody shows you one +of these spreadsheets in later life uh + + align:start position:0% +of these spreadsheets in later life uh + + + align:start position:0% +of these spreadsheets in later life uh +or if when you're working for McKenzie + + align:start position:0% +or if when you're working for McKenzie + + + align:start position:0% +or if when you're working for McKenzie +they ask you to make one for heaven's + + align:start position:0% +they ask you to make one for heaven's + + + align:start position:0% +they ask you to make one for heaven's +sakes think about the central case think + + align:start position:0% +sakes think about the central case think + + + align:start position:0% +sakes think about the central case think +about variations around it he didn't do + + align:start position:0% +about variations around it he didn't do + + + align:start position:0% +about variations around it he didn't do +that he took the optimistic + + align:start position:0% +that he took the optimistic + + + align:start position:0% +that he took the optimistic +case + + align:start position:0% + + + + align:start position:0% + +um kind of a surprise I think what he + + align:start position:0% +um kind of a surprise I think what he + + + align:start position:0% +um kind of a surprise I think what he +should have done is um oops let's get it + + align:start position:0% +should have done is um oops let's get it + + + align:start position:0% +should have done is um oops let's get it +up + + align:start position:0% +up + + + align:start position:0% +up +there yep he should have been a kind of + + align:start position:0% +there yep he should have been a kind of + + + align:start position:0% +there yep he should have been a kind of +central of the road + + align:start position:0% +central of the road + + + align:start position:0% +central of the road +uh here's a beta + + align:start position:0% + + + + align:start position:0% + +question so the discounting applies to + + align:start position:0% +question so the discounting applies to + + + align:start position:0% +question so the discounting applies to +how do we value Energy + + align:start position:0% + + + + align:start position:0% + +savings those Energy savings going to + + align:start position:0% +savings those Energy savings going to + + + align:start position:0% +savings those Energy savings going to +tend to be correlated with the + + align:start position:0% +tend to be correlated with the + + + align:start position:0% +tend to be correlated with the +economy against the economy not at + + align:start position:0% + + + + align:start position:0% + +all the energy + + align:start position:0% +all the energy + + + align:start position:0% +all the energy +savings probably two components one + + align:start position:0% +savings probably two components one + + + align:start position:0% +savings probably two components one +what's the production volume + + align:start position:0% +what's the production volume + + + align:start position:0% +what's the production volume +and let's take that as fixed for the + + align:start position:0% +and let's take that as fixed for the + + + align:start position:0% +and let's take that as fixed for the +moment because they sort of do you tend + + align:start position:0% +moment because they sort of do you tend + + + align:start position:0% +moment because they sort of do you tend +to run the thing flat out unless things + + align:start position:0% +to run the thing flat out unless things + + + align:start position:0% +to run the thing flat out unless things +are terrible and the electricity + + align:start position:0% +are terrible and the electricity + + + align:start position:0% +are terrible and the electricity +price which way does the electricity + + align:start position:0% +price which way does the electricity + + + align:start position:0% +price which way does the electricity +price go with the economy Brendan it + + align:start position:0% +price go with the economy Brendan it + + + align:start position:0% +price go with the economy Brendan it +doesn't vary too much with the economy + + align:start position:0% +doesn't vary too much with the economy + + + align:start position:0% +doesn't vary too much with the economy +I'd say that's more you know energy in + + align:start position:0% +I'd say that's more you know energy in + + + align:start position:0% +I'd say that's more you know energy in +terms of gasoline and stuff that's more + + align:start position:0% +terms of gasoline and stuff that's more + + + align:start position:0% +terms of gasoline and stuff that's more +of that varies a lot more with the eony + + align:start position:0% +of that varies a lot more with the eony + + + align:start position:0% +of that varies a lot more with the eony +but vares a lot more but if you have + + align:start position:0% +but vares a lot more but if you have + + + align:start position:0% +but vares a lot more but if you have +high demand there's going to be a supply + + align:start position:0% +high demand there's going to be a supply + + + align:start position:0% +high demand there's going to be a supply +curve particularly in New York which is + + align:start position:0% +curve particularly in New York which is + + + align:start position:0% +curve particularly in New York which is +a market driven electricity system + + align:start position:0% +a market driven electricity system + + + align:start position:0% +a market driven electricity system +you'll be running up a supply curve so a + + align:start position:0% +you'll be running up a supply curve so a + + + align:start position:0% +you'll be running up a supply curve so a +little bit with the economy I wouldn't + + align:start position:0% +little bit with the economy I wouldn't + + + align:start position:0% +little bit with the economy I wouldn't +say like a very high beta no no no not a + + align:start position:0% +say like a very high beta no no no not a + + + align:start position:0% +say like a very high beta no no no not a +very high beta but a positive beta yeah + + align:start position:0% +very high beta but a positive beta yeah + + + align:start position:0% +very high beta but a positive beta yeah +so maybe yeah the thing is if he was + + align:start position:0% +so maybe yeah the thing is if he was + + + align:start position:0% +so maybe yeah the thing is if he was +using the the whatever the heat that he + + align:start position:0% +using the the whatever the heat that he + + + align:start position:0% +using the the whatever the heat that he +recovers for uh generating more + + align:start position:0% +recovers for uh generating more + + + align:start position:0% +recovers for uh generating more +electricity then maybe that's the case + + align:start position:0% +electricity then maybe that's the case + + + align:start position:0% +electricity then maybe that's the case +but he if he's using heat uh to sell to + + align:start position:0% +but he if he's using heat uh to sell to + + + align:start position:0% +but he if he's using heat uh to sell to +people then you can say that that's + + align:start position:0% +people then you can say that that's + + + align:start position:0% +people then you can say that that's +something that's fairly you know that + + align:start position:0% +something that's fairly you know that + + + align:start position:0% +something that's fairly you know that +people wouldn't be very like Priceless + + align:start position:0% +people wouldn't be very like Priceless + + + align:start position:0% +people wouldn't be very like Priceless +that maybe the E like people will need + + align:start position:0% +that maybe the E like people will need + + + align:start position:0% +that maybe the E like people will need +the heat regardless but what's on the + + align:start position:0% +the heat regardless but what's on the + + + align:start position:0% +the heat regardless but what's on the +what's on the table here is + + align:start position:0% +what's on the table here is + + + align:start position:0% +what's on the table here is +Generation what's on the table is + + align:start position:0% +Generation what's on the table is + + + align:start position:0% +Generation what's on the table is +Generation not heat he doesn't have a he + + align:start position:0% +Generation not heat he doesn't have a he + + + align:start position:0% +Generation not heat he doesn't have a he +doesn't have a scheme to pipe the heat + + align:start position:0% +doesn't have a scheme to pipe the heat + + + align:start position:0% +doesn't have a scheme to pipe the heat +away he has a scheme to use the heat to + + align:start position:0% +away he has a scheme to use the heat to + + + align:start position:0% +away he has a scheme to use the heat to +R use the steam to run a + + align:start position:0% +R use the steam to run a + + + align:start position:0% +R use the steam to run a +turbine so Point good point it's it's + + align:start position:0% +turbine so Point good point it's it's + + + align:start position:0% +turbine so Point good point it's it's +cold in New York even in in good years + + align:start position:0% +cold in New York even in in good years + + + align:start position:0% +cold in New York even in in good years +and bad but but the electricity price is + + align:start position:0% +and bad but but the electricity price is + + + align:start position:0% +and bad but but the electricity price is +what's an issue here you'd value the + + align:start position:0% +what's an issue here you'd value the + + + align:start position:0% +what's an issue here you'd value the +savings so + + align:start position:0% + + + + align:start position:0% + +he you you could + + align:start position:0% +he you you could + + + align:start position:0% +he you you could +argue well you could make it you could + + align:start position:0% +argue well you could make it you could + + + align:start position:0% +argue well you could make it you could +argue you should use a somewhat higher + + align:start position:0% +argue you should use a somewhat higher + + + align:start position:0% +argue you should use a somewhat higher +discount rate uh than the firms over + + align:start position:0% +discount rate uh than the firms over + + + align:start position:0% +discount rate uh than the firms over +than the C cost of capital to the firm + + align:start position:0% +than the C cost of capital to the firm + + + align:start position:0% +than the C cost of capital to the firm +as a whole just because there's a a + + align:start position:0% +as a whole just because there's a a + + + align:start position:0% +as a whole just because there's a a +positive beta we'd have to look at the + + align:start position:0% +positive beta we'd have to look at the + + + align:start position:0% +positive beta we'd have to look at the +firm + + align:start position:0% + + + + align:start position:0% + +now I have no idea yeah does anybody + + align:start position:0% +now I have no idea yeah does anybody + + + align:start position:0% +now I have no idea yeah does anybody +know anything about F the felhide + + align:start position:0% +know anything about F the felhide + + + align:start position:0% +know anything about F the felhide +business it's a very diverse group no + + align:start position:0% +business it's a very diverse group no + + + align:start position:0% +business it's a very diverse group no +one does fahid at + + align:start position:0% +one does fahid at + + + align:start position:0% +one does fahid at +Okay Okay I uh I I don't have a clue + + align:start position:0% +Okay Okay I uh I I don't have a clue + + + align:start position:0% +Okay Okay I uh I I don't have a clue +they wrote the case as if you just ran + + align:start position:0% +they wrote the case as if you just ran + + + align:start position:0% +they wrote the case as if you just ran +the + + align:start position:0% +the + + + align:start position:0% +the +factory uh they didn't talk about it + + align:start position:0% +factory uh they didn't talk about it + + + align:start position:0% +factory uh they didn't talk about it +being cyclical uh and nobody talked + + align:start position:0% +being cyclical uh and nobody talked + + + align:start position:0% +being cyclical uh and nobody talked +about none of none of the naysayers + + align:start position:0% +about none of none of the naysayers + + + align:start position:0% +about none of none of the naysayers +talked about much cyclicality but I + + align:start position:0% +talked about much cyclicality but I + + + align:start position:0% +talked about much cyclicality but I +don't know Brandon yeah I mean I think + + align:start position:0% +don't know Brandon yeah I mean I think + + + align:start position:0% +don't know Brandon yeah I mean I think +people are still going to die + + align:start position:0% +people are still going to die + + + align:start position:0% +people are still going to die +so it has other uses but it does have + + align:start position:0% +so it has other uses but it does have + + + align:start position:0% +so it has other uses but it does have +other uses which the case discussed and + + align:start position:0% +other uses which the case discussed and + + + align:start position:0% +other uses which the case discussed and +I don't remember but uh okay what are + + align:start position:0% +I don't remember but uh okay what are + + + align:start position:0% +I don't remember but uh okay what are +the most what do you think are the most + + align:start position:0% +the most what do you think are the most + + + align:start position:0% +the most what do you think are the most +important assumptions in this in this uh + + align:start position:0% + + + + align:start position:0% + +spreadsheet Rachel what do you think + + align:start position:0% + + + + align:start position:0% + +tough call just staring at it yes you'd + + align:start position:0% +tough call just staring at it yes you'd + + + align:start position:0% +tough call just staring at it yes you'd +have to go and and look at you'd have to + + align:start position:0% +have to go and and look at you'd have to + + + align:start position:0% +have to go and and look at you'd have to +do to answer that question and I raise + + align:start position:0% +do to answer that question and I raise + + + align:start position:0% +do to answer that question and I raise +it because that is really the key + + align:start position:0% +it because that is really the key + + + align:start position:0% +it because that is really the key +question if I'm a naysayer and he gives + + align:start position:0% +question if I'm a naysayer and he gives + + + align:start position:0% +question if I'm a naysayer and he gives +me this + + align:start position:0% +me this + + + align:start position:0% +me this +spreadsheet um I say well what did you + + align:start position:0% +spreadsheet um I say well what did you + + + align:start position:0% +spreadsheet um I say well what did you +check how sensitive is this to the + + align:start position:0% +check how sensitive is this to the + + + align:start position:0% +check how sensitive is this to the +discount rate to the electricity price + + align:start position:0% +discount rate to the electricity price + + + align:start position:0% +discount rate to the electricity price +to the electricity inflation how + + align:start position:0% +to the electricity inflation how + + + align:start position:0% +to the electricity inflation how +sensitive is it to variations in the + + align:start position:0% +sensitive is it to variations in the + + + align:start position:0% +sensitive is it to variations in the +installation cost does it matter whether + + align:start position:0% +installation cost does it matter whether + + + align:start position:0% +installation cost does it matter whether +you not whether or not you get the grant + + align:start position:0% +you not whether or not you get the grant + + + align:start position:0% +you not whether or not you get the grant +I can't tell here which are the key + + align:start position:0% +I can't tell here which are the key + + + align:start position:0% +I can't tell here which are the key +assumptions uh but a little fiddling + + align:start position:0% +assumptions uh but a little fiddling + + + align:start position:0% +assumptions uh but a little fiddling +with this can Alex wouldn't the grant be + + align:start position:0% +with this can Alex wouldn't the grant be + + + align:start position:0% +with this can Alex wouldn't the grant be +like the most important assumtion + + align:start position:0% +like the most important assumtion + + + align:start position:0% +like the most important assumtion +because it's like half of your it's half + + align:start position:0% +because it's like half of your it's half + + + align:start position:0% +because it's like half of your it's half +the capital cost if you go down though + + align:start position:0% +the capital cost if you go down though + + + align:start position:0% +the capital cost if you go down though +to his net present value you say well + + align:start position:0% +to his net present value you say well + + + align:start position:0% +to his net present value you say well +that doesn't matter because it's 1725 + + align:start position:0% +that doesn't matter because it's 1725 + + + align:start position:0% +that doesn't matter because it's 1725 +and the net present value is ginormous + + align:start position:0% +and the net present value is ginormous + + + align:start position:0% +and the net present value is ginormous +so lose the grant the qu the the the + + align:start position:0% +so lose the grant the qu the the the + + + align:start position:0% +so lose the grant the qu the the the +question is what is + + align:start position:0% +question is what is + + + align:start position:0% +question is what is +assumptions would turn it + + align:start position:0% +assumptions would turn it + + + align:start position:0% +assumptions would turn it +negative and he didn't answer that I uh + + align:start position:0% +negative and he didn't answer that I uh + + + align:start position:0% +negative and he didn't answer that I uh +if if it saved less than you assumed it + + align:start position:0% +if if it saved less than you assumed it + + + align:start position:0% +if if it saved less than you assumed it +would save well there are a lot of + + align:start position:0% +would save well there are a lot of + + + align:start position:0% +would save well there are a lot of +things that'll do it the question is + + align:start position:0% +things that'll do it the question is + + + align:start position:0% +things that'll do it the question is +which are uncertain that s the technical + + align:start position:0% +which are uncertain that s the technical + + + align:start position:0% +which are uncertain that s the technical +they they describ the technology as + + align:start position:0% +they they describ the technology as + + + align:start position:0% +they they describ the technology as +pretty vanilla so I assume that was + + align:start position:0% +pretty vanilla so I assume that was + + + align:start position:0% +pretty vanilla so I assume that was +you're right that would do it um if you + + align:start position:0% +you're right that would do it um if you + + + align:start position:0% +you're right that would do it um if you +saved less + + align:start position:0% +saved less + + + align:start position:0% +saved less +if if the electricity price collapsed + + align:start position:0% +if if the electricity price collapsed + + + align:start position:0% +if if the electricity price collapsed +if the discount rate were much higher in + + align:start position:0% +if the discount rate were much higher in + + + align:start position:0% +if the discount rate were much higher in +fact for one reason or another if it + + align:start position:0% +fact for one reason or another if it + + + align:start position:0% +fact for one reason or another if it +couldn't do the I mean you could you + + align:start position:0% +couldn't do the I mean you could you + + + align:start position:0% +couldn't do the I mean you could you +could add them + + align:start position:0% +could add them + + + align:start position:0% +could add them +up what you I asked this questions not + + align:start position:0% +up what you I asked this questions not + + + align:start position:0% +up what you I asked this questions not +because I expect you to be able to + + align:start position:0% +because I expect you to be able to + + + align:start position:0% +because I expect you to be able to +answer it but because you always have to + + align:start position:0% +answer it but because you always have to + + + align:start position:0% +answer it but because you always have to +ask that + + align:start position:0% +ask that + + + align:start position:0% +ask that +question uh what's what what's driving + + align:start position:0% +question uh what's what what's driving + + + align:start position:0% +question uh what's what what's driving +this answer what's driving this answer + + align:start position:0% +this answer what's driving this answer + + + align:start position:0% +this answer what's driving this answer +finally did anybody see the mistake in + + align:start position:0% +finally did anybody see the mistake in + + + align:start position:0% +finally did anybody see the mistake in +Computing that present + + align:start position:0% +Computing that present + + + align:start position:0% +Computing that present +value Sarah he started in colum C + + align:start position:0% +value Sarah he started in colum C + + + align:start position:0% +value Sarah he started in colum C +instead ofum + + align:start position:0% + + + + align:start position:0% + +bingoing to if you go here he takes the + + align:start position:0% +bingoing to if you go here he takes the + + + align:start position:0% +bingoing to if you go here he takes the +net present value of it's + + align:start position:0% +net present value of it's + + + align:start position:0% +net present value of it's +c45 uh no the net yeah c45 which is here + + align:start position:0% +c45 uh no the net yeah c45 which is here + + + align:start position:0% +c45 uh no the net yeah c45 which is here +D dot do dot dot c45 which is the after + + align:start position:0% +D dot do dot dot c45 which is the after + + + align:start position:0% +D dot do dot dot c45 which is the after +tax net cash flow that's the right thing + + align:start position:0% +tax net cash flow that's the right thing + + + align:start position:0% +tax net cash flow that's the right thing +all the way + + align:start position:0% +all the way + + + align:start position:0% +all the way +out but he forgot the initial cost + + align:start position:0% + + + + align:start position:0% + +that's one of the most bizarre mistakes + + align:start position:0% +that's one of the most bizarre mistakes + + + align:start position:0% +that's one of the most bizarre mistakes +I've ever + + align:start position:0% +I've ever + + + align:start position:0% +I've ever +seen if you look at there's the formula + + align:start position:0% +seen if you look at there's the formula + + + align:start position:0% +seen if you look at there's the formula +that present value of all the + + align:start position:0% +that present value of all the + + + align:start position:0% +that present value of all the +savings well what what needs to happen + + align:start position:0% +savings well what what needs to happen + + + align:start position:0% +savings well what what needs to happen +here it's got a not available in + + align:start position:0% +here it's got a not available in + + + align:start position:0% +here it's got a not available in +protected + + align:start position:0% +protected + + + align:start position:0% +protected +view do I trust the contents of the file + + align:start position:0% +view do I trust the contents of the file + + + align:start position:0% +view do I trust the contents of the file +of course I trust the contents of the + + align:start position:0% +of course I trust the contents of the + + + align:start position:0% +of course I trust the contents of the +file we're all friends here uh what he + + align:start position:0% +file we're all friends here uh what he + + + align:start position:0% +file we're all friends here uh what he +needs to oh I see cuz I I erased uh what + + align:start position:0% +needs to oh I see cuz I I erased uh what + + + align:start position:0% +needs to oh I see cuz I I erased uh what +I need to do + + align:start position:0% +I need to do + + + align:start position:0% +I need to do +here is I need to + + align:start position:0% +here is I need to + + + align:start position:0% +here is I need to +subtract the initial + + align:start position:0% + + + + align:start position:0% + +cost that doesn't turn it negative but + + align:start position:0% +cost that doesn't turn it negative but + + + align:start position:0% +cost that doesn't turn it negative but +it did make a significant + + align:start position:0% +it did make a significant + + + align:start position:0% +it did make a significant +difference right you see what he did I + + align:start position:0% +difference right you see what he did I + + + align:start position:0% +difference right you see what he did I +just it's one of these you say + + align:start position:0% +just it's one of these you say + + + align:start position:0% +just it's one of these you say +Okay um he took the after tax net cash + + align:start position:0% +Okay um he took the after tax net cash + + + align:start position:0% +Okay um he took the after tax net cash +flow so he went down added the saving + + align:start position:0% +flow so he went down added the saving + + + align:start position:0% +flow so he went down added the saving +added uh that that that's maintenance + + align:start position:0% + + + + align:start position:0% + +savings you got savings on electricity + + align:start position:0% +savings you got savings on electricity + + + align:start position:0% +savings you got savings on electricity +maintenance and chemicals which gets + + align:start position:0% +maintenance and chemicals which gets + + + align:start position:0% +maintenance and chemicals which gets +inflated + + align:start position:0% +inflated + + + align:start position:0% +inflated +um all these get inflated you'll see the + + align:start position:0% +um all these get inflated you'll see the + + + align:start position:0% +um all these get inflated you'll see the +inflation rate coming in + + align:start position:0% +inflation rate coming in + + + align:start position:0% +inflation rate coming in +here coming in coming in adds them up + + align:start position:0% +here coming in coming in adds them up + + + align:start position:0% +here coming in coming in adds them up +subtracts the required maintenance gets + + align:start position:0% +subtracts the required maintenance gets + + + align:start position:0% +subtracts the required maintenance gets +the net gets the gross margin so to + + align:start position:0% +the net gets the gross margin so to + + + align:start position:0% +the net gets the gross margin so to +speak subtracts depreciation to get the + + align:start position:0% +speak subtracts depreciation to get the + + + align:start position:0% +speak subtracts depreciation to get the +impact on earnings that'd be the + + align:start position:0% +impact on earnings that'd be the + + + align:start position:0% +impact on earnings that'd be the +increase in + + align:start position:0% +increase in + + + align:start position:0% +increase in +earnings gets the taxes adds back + + align:start position:0% +earnings gets the taxes adds back + + + align:start position:0% +earnings gets the taxes adds back +depreciation uh does all + + align:start position:0% +depreciation uh does all + + + align:start position:0% +depreciation uh does all +that row 45 is the right row Net Present + + align:start position:0% +that row 45 is the right row Net Present + + + align:start position:0% +that row 45 is the right row Net Present +Value forgot the initial investment + + align:start position:0% +Value forgot the initial investment + + + align:start position:0% +Value forgot the initial investment +cost that's a bad move that's a bad move + + align:start position:0% +cost that's a bad move that's a bad move + + + align:start position:0% +cost that's a bad move that's a bad move +okay Darren is not doing real well here + + align:start position:0% +okay Darren is not doing real well here + + + align:start position:0% +okay Darren is not doing real well here +uh + + align:start position:0% +uh + + + align:start position:0% +uh +did anybody see anybody look at the + + align:start position:0% +did anybody see anybody look at the + + + align:start position:0% +did anybody see anybody look at the +payback or the internal rate of + + align:start position:0% + + + + align:start position:0% + +return I just want to go back to the + + align:start position:0% +return I just want to go back to the + + + align:start position:0% +return I just want to go back to the +Assumption you're also assuming that for + + align:start position:0% +Assumption you're also assuming that for + + + align:start position:0% +Assumption you're also assuming that for +10 years your production of form Al do + + align:start position:0% +10 years your production of form Al do + + + align:start position:0% +10 years your production of form Al do +the + + align:start position:0% +the + + + align:start position:0% +the +same he's making that assumption + + align:start position:0% +same he's making that assumption + + + align:start position:0% +same he's making that assumption +um and we don't know how sensible it is + + align:start position:0% +um and we don't know how sensible it is + + + align:start position:0% +um and we don't know how sensible it is +because we don't know much about the + + align:start position:0% +because we don't know much about the + + + align:start position:0% +because we don't know much about the +faldy market + + align:start position:0% +faldy market + + + align:start position:0% +faldy market +um they say that they run the plant 24 + + align:start position:0% +um they say that they run the plant 24 + + + align:start position:0% +um they say that they run the plant 24 +hours a day 365 days a year and it's a + + align:start position:0% +hours a day 365 days a year and it's a + + + align:start position:0% +hours a day 365 days a year and it's a +highly automated + + align:start position:0% +highly automated + + + align:start position:0% +highly automated +facility and he's assuming that'll + + align:start position:0% +facility and he's assuming that'll + + + align:start position:0% +facility and he's assuming that'll +continue um it's not clear what other + + align:start position:0% +continue um it's not clear what other + + + align:start position:0% +continue um it's not clear what other +assumption you ought to make but you're + + align:start position:0% +assumption you ought to make but you're + + + align:start position:0% +assumption you ought to make but you're +right that's a key + + align:start position:0% +right that's a key + + + align:start position:0% +right that's a key +assumption if the plant shuts down or + + align:start position:0% +assumption if the plant shuts down or + + + align:start position:0% +assumption if the plant shuts down or +goes to one shift those savings figures + + align:start position:0% +goes to one shift those savings figures + + + align:start position:0% +goes to one shift those savings figures +get + + align:start position:0% +get + + + align:start position:0% +get +cut uh actual sign I mean the science + + align:start position:0% +cut uh actual sign I mean the science + + + align:start position:0% +cut uh actual sign I mean the science +like if if your Delta e is less and + + align:start position:0% +like if if your Delta e is less and + + + align:start position:0% +like if if your Delta e is less and +stuff like that like if you is less + + align:start position:0% +stuff like that like if you is less + + + align:start position:0% +stuff like that like if you is less +make develop Catalyst well you could you + + align:start position:0% +make develop Catalyst well you could you + + + align:start position:0% +make develop Catalyst well you could you +could do it right I mean if it's + + align:start position:0% +could do it right I mean if it's + + + align:start position:0% +could do it right I mean if it's +proportional to + + align:start position:0% +proportional to + + + align:start position:0% +proportional to +throughput the case explicitly states + + align:start position:0% +throughput the case explicitly states + + + align:start position:0% +throughput the case explicitly states +that the board mainly cares about + + align:start position:0% +that the board mainly cares about + + + align:start position:0% +that the board mainly cares about +production of form alide is y use of + + align:start position:0% + + + + align:start position:0% + +electricity uh I'm not sure I get it + + align:start position:0% +electricity uh I'm not sure I get it + + + align:start position:0% +electricity uh I'm not sure I get it +what you're they mainly care about form + + align:start position:0% +what you're they mainly care about form + + + align:start position:0% +what you're they mainly care about form +aldhy and he's + + align:start position:0% +aldhy and he's + + + align:start position:0% +aldhy and he's +assuming that we're just going to keep + + align:start position:0% +assuming that we're just going to keep + + + align:start position:0% +assuming that we're just going to keep +running it flat out because the board + + align:start position:0% +running it flat out because the board + + + align:start position:0% +running it flat out because the board +cares about production I mean if the + + align:start position:0% +cares about production I mean if the + + + align:start position:0% +cares about production I mean if the +market dies or if there's a plant + + align:start position:0% +market dies or if there's a plant + + + align:start position:0% +market dies or if there's a plant +problem that won't happen and you just + + align:start position:0% +problem that won't happen and you just + + + align:start position:0% +problem that won't happen and you just +cut the savings proportionately well + + align:start position:0% +cut the savings proportionately well + + + align:start position:0% +cut the savings proportionately well +you'd cut the savings on electricity and + + align:start position:0% +you'd cut the savings on electricity and + + + align:start position:0% +you'd cut the savings on electricity and +chemicals proportionately I'd have to + + align:start position:0% +chemicals proportionately I'd have to + + + align:start position:0% +chemicals proportionately I'd have to +think about + + align:start position:0% +think about + + + align:start position:0% +think about +maintenance yeah okay + + align:start position:0% +maintenance yeah okay + + + align:start position:0% +maintenance yeah okay +um internal rate of return how did he do + + align:start position:0% +um internal rate of return how did he do + + + align:start position:0% +um internal rate of return how did he do +that it's + + align:start position:0% + + + + align:start position:0% + +Roa um and the formula is up + + align:start position:0% + + + + align:start position:0% + +there you can tell it's an internal rate + + align:start position:0% +there you can tell it's an internal rate + + + align:start position:0% +there you can tell it's an internal rate +of return because that's what Excel + + align:start position:0% +of return because that's what Excel + + + align:start position:0% +of return because that's what Excel +calls the + + align:start position:0% +calls the + + + align:start position:0% +calls the +formula uh and if you look at it it's um + + align:start position:0% +formula uh and if you look at it it's um + + + align:start position:0% +formula uh and if you look at it it's um +and 15% is an initial guess it's a it's + + align:start position:0% +and 15% is an initial guess it's a it's + + + align:start position:0% +and 15% is an initial guess it's a it's +an iterative procedure um it's b49 to + + align:start position:0% +an iterative procedure um it's b49 to + + + align:start position:0% +an iterative procedure um it's b49 to +r49 so it's the pre-tax it's the + + align:start position:0% +r49 so it's the pre-tax it's the + + + align:start position:0% +r49 so it's the pre-tax it's the +internal rate of return on the pre-tax + + align:start position:0% +internal rate of return on the pre-tax + + + align:start position:0% +internal rate of return on the pre-tax +cash + + align:start position:0% +cash + + + align:start position:0% +cash +flow + + align:start position:0% +flow + + + align:start position:0% +flow +which why would you do + + align:start position:0% +which why would you do + + + align:start position:0% +which why would you do +that why wouldn't you take into account + + align:start position:0% +that why wouldn't you take into account + + + align:start position:0% +that why wouldn't you take into account +the effect effect of + + align:start position:0% +the effect effect of + + + align:start position:0% +the effect effect of +taxes if you looked at that that's weird + + align:start position:0% +taxes if you looked at that that's weird + + + align:start position:0% +taxes if you looked at that that's weird +you should do it up + + align:start position:0% +you should do it up + + + align:start position:0% +you should do it up +here um and we could do it I haven't + + align:start position:0% +here um and we could do it I haven't + + + align:start position:0% +here um and we could do it I haven't +it's going to be significant but um + + align:start position:0% +it's going to be significant but um + + + align:start position:0% +it's going to be significant but um +that's just + + align:start position:0% +that's just + + + align:start position:0% +that's just +strange that's just + + align:start position:0% +strange that's just + + + align:start position:0% +strange that's just +strange and just for humor you really + + align:start position:0% +strange and just for humor you really + + + align:start position:0% +strange and just for humor you really +have to look at the formulas in a + + align:start position:0% +have to look at the formulas in a + + + align:start position:0% +have to look at the formulas in a +spreadsheet + + align:start position:0% + + + + align:start position:0% + +that's he didn't actually compute the + + align:start position:0% +that's he didn't actually compute the + + + align:start position:0% +that's he didn't actually compute the +payback + + align:start position:0% +payback + + + align:start position:0% +payback +per that slide I did he didn't actually + + align:start position:0% +per that slide I did he didn't actually + + + align:start position:0% +per that slide I did he didn't actually +see when you get your money back he may + + align:start position:0% +see when you get your money back he may + + + align:start position:0% +see when you get your money back he may +he he went up here and took + + align:start position:0% +he he went up here and took + + + align:start position:0% +he he went up here and took +the installed cost divided it by + + align:start position:0% +the installed cost divided it by + + + align:start position:0% +the installed cost divided it by +the c21 minus + + align:start position:0% +the c21 minus + + + align:start position:0% +the c21 minus +c29 + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% +um + + + align:start position:0% +um +yeah divided it by what amounts to G3 + + align:start position:0% +yeah divided it by what amounts to G3 + + + align:start position:0% +yeah divided it by what amounts to G3 +the C32 divided by the annual Savings in + + align:start position:0% +the C32 divided by the annual Savings in + + + align:start position:0% +the C32 divided by the annual Savings in +the first + + align:start position:0% +the first + + + align:start position:0% +the first +year but the savings differ Year + + align:start position:0% +year but the savings differ Year + + + align:start position:0% +year but the savings differ Year +bye so it's just a very and he doesn't + + align:start position:0% +bye so it's just a very and he doesn't + + + align:start position:0% +bye so it's just a very and he doesn't +consider + + align:start position:0% +consider + + + align:start position:0% +consider +taxes so this is a good-looking + + align:start position:0% +taxes so this is a good-looking + + + align:start position:0% +taxes so this is a good-looking +spreadsheet and what astonished me when + + align:start position:0% +spreadsheet and what astonished me when + + + align:start position:0% +spreadsheet and what astonished me when +I looked at it was wait a minute that's + + align:start position:0% +I looked at it was wait a minute that's + + + align:start position:0% +I looked at it was wait a minute that's +wrong that's wrong that's wrong + + align:start position:0% +wrong that's wrong that's wrong + + + align:start position:0% +wrong that's wrong that's wrong +otherwise pretty good otherwise pretty + + align:start position:0% +otherwise pretty good otherwise pretty + + + align:start position:0% +otherwise pretty good otherwise pretty +good any questions about the spreadsheet + + align:start position:0% + + + + align:start position:0% + +okay let's leave this no I + + align:start position:0% +okay let's leave this no I + + + align:start position:0% +okay let's leave this no I +don't let's go away and let's go back + + align:start position:0% + + + + align:start position:0% + +so I just put the spreadsheet with the + + align:start position:0% +so I just put the spreadsheet with the + + + align:start position:0% +so I just put the spreadsheet with the +formulas in the notes those are the + + align:start position:0% +formulas in the notes those are the + + + align:start position:0% +formulas in the notes those are the +issues we've talked + + align:start position:0% +issues we've talked + + + align:start position:0% +issues we've talked +about now let's talk about let's see + + align:start position:0% + + + + align:start position:0% + +let's talk about the naysayers so I'm + + align:start position:0% +let's talk about the naysayers so I'm + + + align:start position:0% +let's talk about the naysayers so I'm +guessing I haven't spent my life doing + + align:start position:0% +guessing I haven't spent my life doing + + + align:start position:0% +guessing I haven't spent my life doing +this + + align:start position:0% +this + + + align:start position:0% +this +spreadsheet uh but I'm guessing if you + + align:start position:0% +spreadsheet uh but I'm guessing if you + + + align:start position:0% +spreadsheet uh but I'm guessing if you +run through all of the things that we've + + align:start position:0% +run through all of the things that we've + + + align:start position:0% +run through all of the things that we've +talked about you know the basic + + align:start position:0% +talked about you know the basic + + + align:start position:0% +talked about you know the basic +assumptions look + + align:start position:0% +assumptions look + + + align:start position:0% +assumptions look +okay + + align:start position:0% +okay + + + align:start position:0% +okay +um the + + align:start position:0% +um the + + + align:start position:0% +um the +um numbers he's too optimistic but his + + align:start position:0% +um numbers he's too optimistic but his + + + align:start position:0% +um numbers he's too optimistic but his +his discount rat's probably a little + + align:start position:0% +his discount rat's probably a little + + + align:start position:0% +his discount rat's probably a little +high + + align:start position:0% +high + + + align:start position:0% +high +so I'm guessing that if you fiddle and + + align:start position:0% +so I'm guessing that if you fiddle and + + + align:start position:0% +so I'm guessing that if you fiddle and +didd you will come to the conclusion + + align:start position:0% +didd you will come to the conclusion + + + align:start position:0% +didd you will come to the conclusion +that it does have a positive Net Present + + align:start position:0% + + + + align:start position:0% + +Value First + + align:start position:0% +Value First + + + align:start position:0% +Value First +objection you were now Darren folks + + align:start position:0% +objection you were now Darren folks + + + align:start position:0% +objection you were now Darren folks +first objection if it's such a great + + align:start position:0% +first objection if it's such a great + + + align:start position:0% +first objection if it's such a great +idea how come nobody else is doing + + align:start position:0% +idea how come nobody else is doing + + + align:start position:0% +idea how come nobody else is doing +it and your answer + + align:start position:0% +it and your answer + + + align:start position:0% +it and your answer +is obadia what do you say you're going + + align:start position:0% +is obadia what do you say you're going + + + align:start position:0% +is obadia what do you say you're going +to just take that you're not going to + + align:start position:0% +to just take that you're not going to + + + align:start position:0% +to just take that you're not going to +just take that what's your + + align:start position:0% + + + + align:start position:0% + +answer nobody + + align:start position:0% +answer nobody + + + align:start position:0% +answer nobody +has might be we're + + align:start position:0% +has might be we're + + + align:start position:0% +has might be we're +smart might be this is a chance to take + + align:start position:0% +smart might be this is a chance to take + + + align:start position:0% +smart might be this is a chance to take +a leadership position Charlotte it could + + align:start position:0% +a leadership position Charlotte it could + + + align:start position:0% +a leadership position Charlotte it could +be that like the reason they're + + align:start position:0% +be that like the reason they're + + + align:start position:0% +be that like the reason they're +considering this is because they do have + + align:start position:0% +considering this is because they do have + + + align:start position:0% +considering this is because they do have +all that excess heat and steam that's + + align:start position:0% +all that excess heat and steam that's + + + align:start position:0% +all that excess heat and steam that's +cting their plant and maybe other + + align:start position:0% +cting their plant and maybe other + + + align:start position:0% +cting their plant and maybe other +people's plants are designed in a way + + align:start position:0% +people's plants are designed in a way + + + align:start position:0% +people's plants are designed in a way +that they never had that problem before + + align:start position:0% +that they never had that problem before + + + align:start position:0% +that they never had that problem before +so have I considered + + align:start position:0% +so have I considered + + + align:start position:0% +so have I considered +it could be although it sounds like a + + align:start position:0% +it could be although it sounds like a + + + align:start position:0% +it could be although it sounds like a +standard problem the way they describe + + align:start position:0% +standard problem the way they describe + + + align:start position:0% +standard problem the way they describe +the basic reaction you just dump this + + align:start position:0% +the basic reaction you just dump this + + + align:start position:0% +the basic reaction you just dump this +stuff in a vat and you get it gets hot + + align:start position:0% +stuff in a vat and you get it gets hot + + + align:start position:0% +stuff in a vat and you get it gets hot +Martha in warmer areas don't the same + + align:start position:0% +Martha in warmer areas don't the same + + + align:start position:0% +Martha in warmer areas don't the same +issue with ice of yor they might not + + align:start position:0% +issue with ice of yor they might not + + + align:start position:0% +issue with ice of yor they might not +have the same issue with ice they might + + align:start position:0% +have the same issue with ice they might + + + align:start position:0% +have the same issue with ice they might +all yeah the ice is kind of a big deal + + align:start position:0% +all yeah the ice is kind of a big deal + + + align:start position:0% +all yeah the ice is kind of a big deal +you're right if you're if you're in the + + align:start position:0% +you're right if you're if you're in the + + + align:start position:0% +you're right if you're if you're in the +middle of the desert and nobody can see + + align:start position:0% +middle of the desert and nobody can see + + + align:start position:0% +middle of the desert and nobody can see +you venting a lot of steam you might + + align:start position:0% +you venting a lot of steam you might + + + align:start position:0% +you venting a lot of steam you might +just say of course if you're in the + + align:start position:0% +just say of course if you're in the + + + align:start position:0% +just say of course if you're in the +middle of the desert you may have a + + align:start position:0% +middle of the desert you may have a + + + align:start position:0% +middle of the desert you may have a +water problem + + align:start position:0% +water problem + + + align:start position:0% +water problem +but uh actually I think my my response + + align:start position:0% +but uh actually I think my my response + + + align:start position:0% +but uh actually I think my my response +would be this is an opportunity to show + + align:start position:0% +would be this is an opportunity to show + + + align:start position:0% +would be this is an opportunity to show +leadership uh uh I I but let's try the + + align:start position:0% +leadership uh uh I I but let's try the + + + align:start position:0% +leadership uh uh I I but let's try the +next + + align:start position:0% +next + + + align:start position:0% +next +one what's your answer to that one this + + align:start position:0% +one what's your answer to that one this + + + align:start position:0% +one what's your answer to that one this +is what I what what I got is I estimated + + align:start position:0% +is what I what what I got is I estimated + + + align:start position:0% +is what I what what I got is I estimated +the the the + + align:start position:0% +the the the + + + align:start position:0% +the the the +revenue yeah yeah I love your I love + + align:start position:0% +revenue yeah yeah I love your I love + + + align:start position:0% +revenue yeah yeah I love your I love +your Net Present Value that's just swell + + align:start position:0% +your Net Present Value that's just swell + + + align:start position:0% +your Net Present Value that's just swell +but there's a risk here there's always a + + align:start position:0% +but there's a risk here there's always a + + + align:start position:0% +but there's a risk here there's always a +risk here um + + align:start position:0% + + + + align:start position:0% + +yes there's always a risk talked about + + align:start position:0% +yes there's always a risk talked about + + + align:start position:0% +yes there's always a risk talked about +outage we'll come back to outage but I + + align:start position:0% +outage we'll come back to outage but I + + + align:start position:0% +outage we'll come back to outage but I +mean it's 2% of Revenue you're going to + + align:start position:0% +mean it's 2% of Revenue you're going to + + + align:start position:0% +mean it's 2% of Revenue you're going to +make the plant more complicated and if + + align:start position:0% +make the plant more complicated and if + + + align:start position:0% +make the plant more complicated and if +you're lucky we'll save 2% of Revenue + + align:start position:0% +you're lucky we'll save 2% of Revenue + + + align:start position:0% +you're lucky we'll save 2% of Revenue +why should we do that it's going to be + + align:start position:0% +why should we do that it's going to be + + + align:start position:0% +why should we do that it's going to be +lost in the noise as production varies + + align:start position:0% +lost in the noise as production varies + + + align:start position:0% +lost in the noise as production varies +as price varies as everything varies why + + align:start position:0% +as price varies as everything varies why + + + align:start position:0% +as price varies as everything varies why +should we complicate our + + align:start position:0% +should we complicate our + + + align:start position:0% +should we complicate our +lives now these kinds of things come up + + align:start position:0% +lives now these kinds of things come up + + + align:start position:0% +lives now these kinds of things come up +Sam one you could say the whole you put + + align:start position:0% +Sam one you could say the whole you put + + + align:start position:0% +Sam one you could say the whole you put +the whole green angle like it's a good + + align:start position:0% +the whole green angle like it's a good + + + align:start position:0% +the whole green angle like it's a good +way to make the environment better but + + align:start position:0% +way to make the environment better but + + + align:start position:0% +way to make the environment better but +also you can say about like in the + + align:start position:0% +also you can say about like in the + + + align:start position:0% +also you can say about like in the +future we don't know what's going to + + align:start position:0% +future we don't know what's going to + + + align:start position:0% +future we don't know what's going to +happen to the rice of electricity and if + + align:start position:0% +happen to the rice of electricity and if + + + align:start position:0% +happen to the rice of electricity and if +it rises it's a good insurance policy we + + align:start position:0% +it rises it's a good insurance policy we + + + align:start position:0% +it rises it's a good insurance policy we +have and also you can say that you know + + align:start position:0% +have and also you can say that you know + + + align:start position:0% +have and also you can say that you know +the technology that we're adding has a + + align:start position:0% +the technology that we're adding has a + + + align:start position:0% +the technology that we're adding has a +pretty good track record like it's not + + align:start position:0% +pretty good track record like it's not + + + align:start position:0% +pretty good track record like it's not +that complex yeah I mean this is this is + + align:start position:0% +that complex yeah I mean this is this is + + + align:start position:0% +that complex yeah I mean this is this is +not the first time this contractor's + + align:start position:0% +not the first time this contractor's + + + align:start position:0% +not the first time this contractor's +ever done it so the risk is doesn't + + align:start position:0% +ever done it so the risk is doesn't + + + align:start position:0% +ever done it so the risk is doesn't +sound to doesn't sound like it's that + + align:start position:0% +sound to doesn't sound like it's that + + + align:start position:0% +sound to doesn't sound like it's that +high 2% is + + align:start position:0% +high 2% is + + + align:start position:0% +high 2% is +2% not bad anybody else wrong + + align:start position:0% +2% not bad anybody else wrong + + + align:start position:0% +2% not bad anybody else wrong +it's not actually changing the formal + + align:start position:0% +it's not actually changing the formal + + + align:start position:0% +it's not actually changing the formal +process so it's not complicating it in + + align:start position:0% +process so it's not complicating it in + + + align:start position:0% +process so it's not complicating it in +that respect there's also the safety + + align:start position:0% +that respect there's also the safety + + + align:start position:0% +that respect there's also the safety +issue and like you said the uh green + + align:start position:0% +issue and like you said the uh green + + + align:start position:0% +issue and like you said the uh green +issue safety issue being like the ice + + align:start position:0% +issue safety issue being like the ice + + + align:start position:0% +issue safety issue being like the ice +yeah got the safety issue that's a risk + + align:start position:0% +yeah got the safety issue that's a risk + + + align:start position:0% +yeah got the safety issue that's a risk +boy somebody slips and falls on that ice + + align:start position:0% +boy somebody slips and falls on that ice + + + align:start position:0% +boy somebody slips and falls on that ice +and uh we get we get stuck with uh nice + + align:start position:0% +and uh we get we get stuck with uh nice + + + align:start position:0% +and uh we get we get stuck with uh nice +negligence big medical bills sympathetic + + align:start position:0% +negligence big medical bills sympathetic + + + align:start position:0% +negligence big medical bills sympathetic +plaintive it's really depressing Scott + + align:start position:0% +plaintive it's really depressing Scott + + + align:start position:0% +plaintive it's really depressing Scott +so I think if you look at it in terms of + + align:start position:0% +so I think if you look at it in terms of + + + align:start position:0% +so I think if you look at it in terms of +the percentage it does doesn't sound + + align:start position:0% +the percentage it does doesn't sound + + + align:start position:0% +the percentage it does doesn't sound +like very much like saying like oh it's + + align:start position:0% +like very much like saying like oh it's + + + align:start position:0% +like very much like saying like oh it's +only 2% of our Revenue that doesn't + + align:start position:0% +only 2% of our Revenue that doesn't + + + align:start position:0% +only 2% of our Revenue that doesn't +sound like very much at all but if you + + align:start position:0% +sound like very much at all but if you + + + align:start position:0% +sound like very much at all but if you +say oh it's $300,000 we're saving then + + align:start position:0% +say oh it's $300,000 we're saving then + + + align:start position:0% +say oh it's $300,000 we're saving then +that's like while it may be only a small + + align:start position:0% +that's like while it may be only a small + + + align:start position:0% +that's like while it may be only a small +portion of the revenue $3,000 is a large + + align:start position:0% +portion of the revenue $3,000 is a large + + + align:start position:0% +portion of the revenue $3,000 is a large +amount of money to pretty much + + align:start position:0% +amount of money to pretty much + + + align:start position:0% +amount of money to pretty much +any to a $5 million operation I don't + + align:start position:0% +any to a $5 million operation I don't + + + align:start position:0% +any to a $5 million operation I don't +know maybe yeah yeah it's not trivial in + + align:start position:0% +know maybe yeah yeah it's not trivial in + + + align:start position:0% +know maybe yeah yeah it's not trivial in +the absolute anybody else uh um they're + + align:start position:0% +the absolute anybody else uh um they're + + + align:start position:0% +the absolute anybody else uh um they're +also going to use current employees to + + align:start position:0% +also going to use current employees to + + + align:start position:0% +also going to use current employees to +run the same thing so I presume their + + align:start position:0% +run the same thing so I presume their + + + align:start position:0% +run the same thing so I presume their +their um salary would increase I + + align:start position:0% +their um salary would increase I + + + align:start position:0% +their um salary would increase I +wouldn't want to presume that I want I + + align:start position:0% +wouldn't want to presume that I want I + + + align:start position:0% +wouldn't want to presume that I want I +I'd say their job satisfaction would + + align:start position:0% +I'd say their job satisfaction would + + + align:start position:0% +I'd say their job satisfaction would +increase because it would make their + + align:start position:0% +increase because it would make their + + + align:start position:0% +increase because it would make their +jobs more interesting that's that's the + + align:start position:0% +jobs more interesting that's that's the + + + align:start position:0% +jobs more interesting that's that's the +that's the pitch I'd use and it's a good + + align:start position:0% +that's the pitch I'd use and it's a good + + + align:start position:0% +that's the pitch I'd use and it's a good +point you might want to see if you can + + align:start position:0% +point you might want to see if you can + + + align:start position:0% +point you might want to see if you can +get them behind + + align:start position:0% +get them behind + + + align:start position:0% +get them behind +it you might want to you might want to + + align:start position:0% +it you might want to you might want to + + + align:start position:0% +it you might want to you might want to +talk it up so you can say well I've + + align:start position:0% +talk it up so you can say well I've + + + align:start position:0% +talk it up so you can say well I've +talked it with talked up with the folks + + align:start position:0% +talked it with talked up with the folks + + + align:start position:0% +talked it with talked up with the folks +in the factory and they actually like + + align:start position:0% +in the factory and they actually like + + + align:start position:0% +in the factory and they actually like +the idea everon + + align:start position:0% +the idea everon + + + align:start position:0% +the idea everon +having those same people who are work in + + align:start position:0% +having those same people who are work in + + + align:start position:0% +having those same people who are work in +the factory doing extra things I think + + align:start position:0% +the factory doing extra things I think + + + align:start position:0% +the factory doing extra things I think +it eliminates some risk because um more + + align:start position:0% +it eliminates some risk because um more + + + align:start position:0% +it eliminates some risk because um more +familiar with the + + align:start position:0% + + + + align:start position:0% + +process that helps yeah these people + + align:start position:0% +process that helps yeah these people + + + align:start position:0% +process that helps yeah these people +know it they they want to keep the plant + + align:start position:0% +know it they they want to keep the plant + + + align:start position:0% +know it they they want to keep the plant +running we all want to keep the plant + + align:start position:0% +running we all want to keep the plant + + + align:start position:0% +running we all want to keep the plant +running um this actually is a common I + + align:start position:0% +running um this actually is a common I + + + align:start position:0% +running um this actually is a common I +mean these paraphrase the the objections + + align:start position:0% +mean these paraphrase the the objections + + + align:start position:0% +mean these paraphrase the the objections +in the case I've added a little bit of + + align:start position:0% +in the case I've added a little bit of + + + align:start position:0% +in the case I've added a little bit of +what you always hear this this is + + align:start position:0% +what you always hear this this is + + + align:start position:0% +what you always hear this this is +another + + align:start position:0% +another + + + align:start position:0% +another +one we can invest and grow + + align:start position:0% +one we can invest and grow + + + align:start position:0% +one we can invest and grow +capacity as opposed to this complicating + + align:start position:0% +capacity as opposed to this complicating + + + align:start position:0% +capacity as opposed to this complicating +investment and we want to grow the + + align:start position:0% +investment and we want to grow the + + + align:start position:0% +investment and we want to grow the +business you're not growing the + + align:start position:0% +business you're not growing the + + + align:start position:0% +business you're not growing the +business you know if we didn't have + + align:start position:0% +business you know if we didn't have + + + align:start position:0% +business you know if we didn't have +money well then we wouldn't invest but + + align:start position:0% +money well then we wouldn't invest but + + + align:start position:0% +money well then we wouldn't invest but +if times are good and we're selling this + + align:start position:0% +if times are good and we're selling this + + + align:start position:0% +if times are good and we're selling this +stuff we want to make more of it because + + align:start position:0% +stuff we want to make more of it because + + + align:start position:0% +stuff we want to make more of it because +that's how we grow and your investment + + align:start position:0% +that's how we grow and your investment + + + align:start position:0% +that's how we grow and your investment +isn't a growth + + align:start position:0% +isn't a growth + + + align:start position:0% +isn't a growth +investment James well maybe by selling + + align:start position:0% +investment James well maybe by selling + + + align:start position:0% +investment James well maybe by selling +electricity you're + + align:start position:0% + + + + align:start position:0% + +diversify a little safer even though + + align:start position:0% +diversify a little safer even though + + + align:start position:0% +diversify a little safer even though +it's not + + align:start position:0% +it's not + + + align:start position:0% +it's not +much so yeah we're we're we're reducing + + align:start position:0% +much so yeah we're we're we're reducing + + + align:start position:0% +much so yeah we're we're we're reducing +the risk of our operation overall + + align:start position:0% +the risk of our operation overall + + + align:start position:0% +the risk of our operation overall +because of this electricity hedge and + + align:start position:0% +because of this electricity hedge and + + + align:start position:0% +because of this electricity hedge and +that means growth is safer you might try + + align:start position:0% +that means growth is safer you might try + + + align:start position:0% +that means growth is safer you might try +that yes arue that it gives you + + align:start position:0% +that yes arue that it gives you + + + align:start position:0% +that yes arue that it gives you +experience the technology that's more PR + + align:start position:0% +experience the technology that's more PR + + + align:start position:0% +experience the technology that's more PR +friendly in the sense that you have less + + align:start position:0% +friendly in the sense that you have less + + + align:start position:0% +friendly in the sense that you have less +Flume gas putting out it's easier to + + align:start position:0% +Flume gas putting out it's easier to + + + align:start position:0% +Flume gas putting out it's easier to +build things wherever you want CU you + + align:start position:0% +build things wherever you want CU you + + + align:start position:0% +build things wherever you want CU you +get less public out and so that the + + align:start position:0% +get less public out and so that the + + + align:start position:0% +get less public out and so that the +ability to grow more in the + + align:start position:0% + + + + align:start position:0% + +future yeah of course except I mean we + + align:start position:0% +future yeah of course except I mean we + + + align:start position:0% +future yeah of course except I mean we +are making from Malahide we you know we + + align:start position:0% +are making from Malahide we you know we + + + align:start position:0% +are making from Malahide we you know we +can't make it into into flowers + + align:start position:0% +can't make it into into flowers + + + align:start position:0% +can't make it into into flowers +chimo yeah um I think maybe finding like + + align:start position:0% +chimo yeah um I think maybe finding like + + + align:start position:0% +chimo yeah um I think maybe finding like +a better solution to get rid of the + + align:start position:0% +a better solution to get rid of the + + + align:start position:0% +a better solution to get rid of the +steam could allow you to I increased + + align:start position:0% +steam could allow you to I increased + + + align:start position:0% +steam could allow you to I increased +capacity cuz like if it's just like + + align:start position:0% +capacity cuz like if it's just like + + + align:start position:0% +capacity cuz like if it's just like +lying around there's probably a maximum + + align:start position:0% +lying around there's probably a maximum + + + align:start position:0% +lying around there's probably a maximum +amount of that you can produce and have + + align:start position:0% +amount of that you can produce and have + + + align:start position:0% +amount of that you can produce and have +the theme creating ice or that's an + + align:start position:0% +the theme creating ice or that's an + + + align:start position:0% +the theme creating ice or that's an +interesting thought so you're you're + + align:start position:0% +interesting thought so you're you're + + + align:start position:0% +interesting thought so you're you're +saying we can only do so much of this + + align:start position:0% +saying we can only do so much of this + + + align:start position:0% +saying we can only do so much of this +venting and ice and so on and this that + + align:start position:0% +venting and ice and so on and this that + + + align:start position:0% +venting and ice and so on and this that +may someday be a constraint on us yes + + align:start position:0% +may someday be a constraint on us yes + + + align:start position:0% +may someday be a constraint on us yes +and finding like a better solution like + + align:start position:0% +and finding like a better solution like + + + align:start position:0% +and finding like a better solution like +that maybe might make them enable them + + align:start position:0% +that maybe might make them enable them + + + align:start position:0% +that maybe might make them enable them +to expand it even more okay + + align:start position:0% + + + + align:start position:0% + +thanks year that get your initial + + align:start position:0% +thanks year that get your initial + + + align:start position:0% +thanks year that get your initial +investment back you're going have extra + + align:start position:0% +investment back you're going have extra + + + align:start position:0% +investment back you're going have extra +money roughly year three yeah extra + + align:start position:0% +money roughly year three yeah extra + + + align:start position:0% +money roughly year three yeah extra +money extra money you + + align:start position:0% +money extra money you + + + align:start position:0% +money extra money you +invest every year after that oh that's + + align:start position:0% +invest every year after that oh that's + + + align:start position:0% +invest every year after that oh that's +nice that's nice if we play it right I + + align:start position:0% +nice that's nice if we play it right I + + + align:start position:0% +nice that's nice if we play it right I +mean this is presumably you get this + + align:start position:0% +mean this is presumably you get this + + + align:start position:0% +mean this is presumably you get this +stuff you're getting this um they don't + + align:start position:0% +stuff you're getting this um they don't + + + align:start position:0% +stuff you're getting this um they don't +specify in the case who he's talking to + + align:start position:0% +specify in the case who he's talking to + + + align:start position:0% +specify in the case who he's talking to +but presumably this is is a middle + + align:start position:0% +but presumably this is is a middle + + + align:start position:0% +but presumably this is is a middle +management group that passes on Capital + + align:start position:0% +management group that passes on Capital + + + align:start position:0% +management group that passes on Capital +spending requests so your response would + + align:start position:0% +spending requests so your response would + + + align:start position:0% +spending requests so your response would +be look + + align:start position:0% +be look + + + align:start position:0% +be look +folks if this plant is more profitable + + align:start position:0% +folks if this plant is more profitable + + + align:start position:0% +folks if this plant is more profitable +which it will be we're going to be able + + align:start position:0% +which it will be we're going to be able + + + align:start position:0% +which it will be we're going to be able +to use that to generate to get more + + align:start position:0% +to use that to generate to get more + + + align:start position:0% +to use that to generate to get more +investment money to to + + align:start position:0% +investment money to to + + + align:start position:0% +investment money to to +expand uh we don't necessarily get to + + align:start position:0% +expand uh we don't necessarily get to + + + align:start position:0% +expand uh we don't necessarily get to +put it in our pocket because it's all + + align:start position:0% +put it in our pocket because it's all + + + align:start position:0% +put it in our pocket because it's all +part of the corporation but it'll be a + + align:start position:0% +part of the corporation but it'll be a + + + align:start position:0% +part of the corporation but it'll be a +good + + align:start position:0% +good + + + align:start position:0% +good +justification Andrew uh what we could be + + align:start position:0% +justification Andrew uh what we could be + + + align:start position:0% +justification Andrew uh what we could be +doing with the uh I it's kind of a + + align:start position:0% +doing with the uh I it's kind of a + + + align:start position:0% +doing with the uh I it's kind of a +question but what you could be doing + + align:start position:0% +question but what you could be doing + + + align:start position:0% +question but what you could be doing +with the money you're using to do this + + align:start position:0% +with the money you're using to do this + + + align:start position:0% +with the money you're using to do this +like isn't that captured by your + + align:start position:0% +like isn't that captured by your + + + align:start position:0% +like isn't that captured by your +discount rate essentially like so can + + align:start position:0% +discount rate essentially like so can + + + align:start position:0% +discount rate essentially like so can +you just argue that uh I mean because + + align:start position:0% +you just argue that uh I mean because + + + align:start position:0% +you just argue that uh I mean because +this kind of an opportunity cost that + + align:start position:0% +this kind of an opportunity cost that + + + align:start position:0% +this kind of an opportunity cost that +they're mentioning right I mean instead + + align:start position:0% +they're mentioning right I mean instead + + + align:start position:0% +they're mentioning right I mean instead +of spending the money to do this you + + align:start position:0% +of spending the money to do this you + + + align:start position:0% +of spending the money to do this you +could spend it to grow the business but + + align:start position:0% +could spend it to grow the business but + + + align:start position:0% +could spend it to grow the business but +then you can answer like but that's why + + align:start position:0% +then you can answer like but that's why + + + align:start position:0% +then you can answer like but that's why +I'm using it is except it in in most + + align:start position:0% +I'm using it is except it in in most + + + align:start position:0% +I'm using it is except it in in most +companies of any size you basically do a + + align:start position:0% +companies of any size you basically do a + + + align:start position:0% +companies of any size you basically do a +capital budgeting process we're going to + + align:start position:0% +capital budgeting process we're going to + + + align:start position:0% +capital budgeting process we're going to +invest X I + + align:start position:0% +invest X I + + + align:start position:0% +invest X I +mean you shouldn't but you do we're + + align:start position:0% +mean you shouldn't but you do we're + + + align:start position:0% +mean you shouldn't but you do we're +going to invest X this year your job is + + align:start position:0% +going to invest X this year your job is + + + align:start position:0% +going to invest X this year your job is +to figure out how best to invest it as + + align:start position:0% +to figure out how best to invest it as + + + align:start position:0% +to figure out how best to invest it as +opposed to saying anything that makes + + align:start position:0% +opposed to saying anything that makes + + + align:start position:0% +opposed to saying anything that makes +that that clears the uh uh has a + + align:start position:0% +that that clears the uh uh has a + + + align:start position:0% +that that clears the uh uh has a +positive net presentence value we'll + + align:start position:0% +positive net presentence value we'll + + + align:start position:0% +positive net presentence value we'll +figure out how to fund I mean if you + + align:start position:0% +figure out how to fund I mean if you + + + align:start position:0% +figure out how to fund I mean if you +have a great + + align:start position:0% +have a great + + + align:start position:0% +have a great +project and it and this is a way of just + + align:start position:0% +project and it and this is a way of just + + + align:start position:0% +project and it and this is a way of just +kind of doing a regular systematic + + align:start position:0% +kind of doing a regular systematic + + + align:start position:0% +kind of doing a regular systematic +budgeting process if you come up with a + + align:start position:0% +budgeting process if you come up with a + + + align:start position:0% +budgeting process if you come up with a +great + + align:start position:0% +great + + + align:start position:0% +great +big great comma big project then you go + + align:start position:0% +big great comma big project then you go + + + align:start position:0% +big great comma big project then you go +to top management and you say I know + + align:start position:0% +to top management and you say I know + + + align:start position:0% +to top management and you say I know +this is over the capital budget but but + + align:start position:0% +this is over the capital budget but but + + + align:start position:0% +this is over the capital budget but but +for little things like this and for this + + align:start position:0% +for little things like this and for this + + + align:start position:0% +for little things like this and for this +company this is probably a relatively + + align:start position:0% +company this is probably a relatively + + + align:start position:0% +company this is probably a relatively +small project Darren doesn't have the + + align:start position:0% +small project Darren doesn't have the + + + align:start position:0% +small project Darren doesn't have the +discretion to do it + + align:start position:0% +discretion to do it + + + align:start position:0% +discretion to do it +himself routine things he probably has a + + align:start position:0% +himself routine things he probably has a + + + align:start position:0% +himself routine things he probably has a +limit you can you can you have a + + align:start position:0% +limit you can you can you have a + + + align:start position:0% +limit you can you can you have a +spending limit without authorization of + + align:start position:0% +spending limit without authorization of + + + align:start position:0% +spending limit without authorization of +without approval of 20,000 maybe maybe + + align:start position:0% +without approval of 20,000 maybe maybe + + + align:start position:0% +without approval of 20,000 maybe maybe +more um + + align:start position:0% +more um + + + align:start position:0% +more um +for anything above that up to some + + align:start position:0% +for anything above that up to some + + + align:start position:0% +for anything above that up to some +ceiling you got to clear it with + + align:start position:0% +ceiling you got to clear it with + + + align:start position:0% +ceiling you got to clear it with +whatever this group is that is full of + + align:start position:0% +whatever this group is that is full of + + + align:start position:0% +whatever this group is that is full of +Skeptics beyond that the group has to go + + align:start position:0% +Skeptics beyond that the group has to go + + + align:start position:0% +Skeptics beyond that the group has to go +and say to top management I know you + + align:start position:0% +and say to top management I know you + + + align:start position:0% +and say to top management I know you +only gave us $800,000 for the fahid + + align:start position:0% +only gave us $800,000 for the fahid + + + align:start position:0% +only gave us $800,000 for the fahid +division but we have this great idea and + + align:start position:0% +division but we have this great idea and + + + align:start position:0% +division but we have this great idea and +we'd like to present it + + align:start position:0% +we'd like to present it + + + align:start position:0% +we'd like to present it +so + + align:start position:0% +so + + + align:start position:0% +so +it's it economizes on top management + + align:start position:0% +it's it economizes on top management + + + align:start position:0% +it's it economizes on top management +time to some extent + + align:start position:0% +time to some extent + + + align:start position:0% +time to some extent +it + + align:start position:0% +it + + + align:start position:0% +it +also + + align:start position:0% +also + + + align:start position:0% +also +um gives you an orderly budgeting + + align:start position:0% +um gives you an orderly budgeting + + + align:start position:0% +um gives you an orderly budgeting +process so you can kind of predict cash + + align:start position:0% +process so you can kind of predict cash + + + align:start position:0% +process so you can kind of predict cash +flows but it imposes this kind of + + align:start position:0% +flows but it imposes this kind of + + + align:start position:0% +flows but it imposes this kind of +constraint I mean Capital budgeting + + align:start position:0% +constraint I mean Capital budgeting + + + align:start position:0% +constraint I mean Capital budgeting +processes do at some point somebody sits + + align:start position:0% +processes do at some point somebody sits + + + align:start position:0% +processes do at some point somebody sits +in the room you know you got a good + + align:start position:0% +in the room you know you got a good + + + align:start position:0% +in the room you know you got a good +project I got a good project we don't + + align:start position:0% +project I got a good project we don't + + + align:start position:0% +project I got a good project we don't +have money for both and they're not so + + align:start position:0% +have money for both and they're not so + + + align:start position:0% +have money for both and they're not so +good that we can get money for both we + + align:start position:0% +good that we can get money for both we + + + align:start position:0% +good that we can get money for both we +need to choose um and there is a + + align:start position:0% +need to choose um and there is a + + + align:start position:0% +need to choose um and there is a +tendency to say + + align:start position:0% +tendency to say + + + align:start position:0% +tendency to say +we want to grow we want to grow that is + + align:start position:0% +we want to grow we want to grow that is + + + align:start position:0% +we want to grow we want to grow that is +an issue faced that the that investments + + align:start position:0% +an issue faced that the that investments + + + align:start position:0% +an issue faced that the that investments +in efficiency and + + align:start position:0% +in efficiency and + + + align:start position:0% +in efficiency and +conservation traditionally face because + + align:start position:0% +conservation traditionally face because + + + align:start position:0% +conservation traditionally face because +they're not growth Investments and + + align:start position:0% +they're not growth Investments and + + + align:start position:0% +they're not growth Investments and +people like growth obina I don't know if + + align:start position:0% +people like growth obina I don't know if + + + align:start position:0% +people like growth obina I don't know if +someone mention this about the second + + align:start position:0% +someone mention this about the second + + + align:start position:0% +someone mention this about the second +Point um but you know it might be 2% of + + align:start position:0% +Point um but you know it might be 2% of + + + align:start position:0% +Point um but you know it might be 2% of +revenue for one plant but what if you + + align:start position:0% +revenue for one plant but what if you + + + align:start position:0% +revenue for one plant but what if you +have several plants they're like this + + align:start position:0% +have several plants they're like this + + + align:start position:0% +have several plants they're like this +plant it's 2% of revenue for all plants + + align:start position:0% +plant it's 2% of revenue for all plants + + + align:start position:0% +plant it's 2% of revenue for all plants +right if if you if you install the + + align:start position:0% +right if if you if you install the + + + align:start position:0% +right if if you if you install the +system at a number of plants you could + + align:start position:0% +system at a number of plants you could + + + align:start position:0% +system at a number of plants you could +easily end up Revenue Savings in in the + + align:start position:0% +easily end up Revenue Savings in in the + + + align:start position:0% +easily end up Revenue Savings in in the +millions you could end up with with a + + align:start position:0% +millions you could end up with with a + + + align:start position:0% +millions you could end up with with a +good number it would still be 2% of + + align:start position:0% +good number it would still be 2% of + + + align:start position:0% +good number it would still be 2% of +Revenue probably on that order okay yep + + align:start position:0% +Revenue probably on that order okay yep + + + align:start position:0% +Revenue probably on that order okay yep +no I + + align:start position:0% + + + + align:start position:0% + +I another way to do that argument and + + align:start position:0% +I another way to do that argument and + + + align:start position:0% +I another way to do that argument and +it's sort of a little variation on the + + align:start position:0% +it's sort of a little variation on the + + + align:start position:0% +it's sort of a little variation on the +first one would be um look guys we can + + align:start position:0% +first one would be um look guys we can + + + align:start position:0% +first one would be um look guys we can +lead the way for the company whatever + + align:start position:0% +lead the way for the company whatever + + + align:start position:0% +lead the way for the company whatever +this group is that's approving the + + align:start position:0% +this group is that's approving the + + + align:start position:0% +this group is that's approving the +budget if this works here and we're very + + align:start position:0% +budget if this works here and we're very + + + align:start position:0% +budget if this works here and we're very +confident it it works we're going to get + + align:start position:0% +confident it it works we're going to get + + + align:start position:0% +confident it it works we're going to get +a lot of points with the company because + + align:start position:0% +a lot of points with the company because + + + align:start position:0% +a lot of points with the company because +we led the way to 2% of Revenue Savings + + align:start position:0% +we led the way to 2% of Revenue Savings + + + align:start position:0% +we led the way to 2% of Revenue Savings +in all of our form alahh operations now + + align:start position:0% +in all of our form alahh operations now + + + align:start position:0% +in all of our form alahh operations now +maybe it's not 2% everywhere we got to + + align:start position:0% +maybe it's not 2% everywhere we got to + + + align:start position:0% +maybe it's not 2% everywhere we got to +run the + + align:start position:0% +run the + + + align:start position:0% +run the +numbers um electricity is probably + + align:start position:0% +numbers um electricity is probably + + + align:start position:0% +numbers um electricity is probably +particularly expensive in Upstate New + + align:start position:0% +particularly expensive in Upstate New + + + align:start position:0% +particularly expensive in Upstate New +York would be cheaper in Ohio but that's + + align:start position:0% +York would be cheaper in Ohio but that's + + + align:start position:0% +York would be cheaper in Ohio but that's +where that's where I'd go with that I + + align:start position:0% +where that's where I'd go with that I + + + align:start position:0% +where that's where I'd go with that I +wouldn't say 2% is 2% is um 2% is big if + + align:start position:0% +wouldn't say 2% is 2% is um 2% is big if + + + align:start position:0% +wouldn't say 2% is 2% is um 2% is big if +I If I multiply it by a large number I + + align:start position:0% +I If I multiply it by a large number I + + + align:start position:0% +I If I multiply it by a large number I +would say it's in our interest as the + + align:start position:0% +would say it's in our interest as the + + + align:start position:0% +would say it's in our interest as the +group sitting around the table to + + align:start position:0% +group sitting around the table to + + + align:start position:0% +group sitting around the table to +demonstrate to the guys up + + align:start position:0% +demonstrate to the guys up + + + align:start position:0% +demonstrate to the guys up +above that that we can we can do this + + align:start position:0% +above that that we can we can do this + + + align:start position:0% +above that that we can we can do this +okay here's another one this is a + + align:start position:0% + + + + align:start position:0% + +killer our bonuses depend on + + align:start position:0% +killer our bonuses depend on + + + align:start position:0% +killer our bonuses depend on +compensation or on production that's how + + align:start position:0% +compensation or on production that's how + + + align:start position:0% +compensation or on production that's how +we do it and you're telling me it's 5 + + align:start position:0% +we do it and you're telling me it's 5 + + + align:start position:0% +we do it and you're telling me it's 5 +days of downtime and we can recover for + + align:start position:0% +days of downtime and we can recover for + + + align:start position:0% +days of downtime and we can recover for +it recover from it but we don't know we + + align:start position:0% +it recover from it but we don't know we + + + align:start position:0% +it recover from it but we don't know we +can recover from it + + align:start position:0% +can recover from it + + + align:start position:0% +can recover from it +you're putting my trip to the Caribbean + + align:start position:0% +you're putting my trip to the Caribbean + + + align:start position:0% +you're putting my trip to the Caribbean +at risk and it's very cold in Upstate + + align:start position:0% +at risk and it's very cold in Upstate + + + align:start position:0% +at risk and it's very cold in Upstate +New York in the winter I need that + + align:start position:0% +New York in the winter I need that + + + align:start position:0% +New York in the winter I need that +bonus this is a + + align:start position:0% +bonus this is a + + + align:start position:0% +bonus this is a +risk what's your response Casey you look + + align:start position:0% +risk what's your response Casey you look + + + align:start position:0% +risk what's your response Casey you look +ready you're ready on this one am I + + align:start position:0% +ready you're ready on this one am I + + + align:start position:0% +ready you're ready on this one am I +right well um first they might be able + + align:start position:0% +right well um first they might be able + + + align:start position:0% +right well um first they might be able +to switch their production schedule to + + align:start position:0% +to switch their production schedule to + + + align:start position:0% +to switch their production schedule to +kind of account for taking those days + + align:start position:0% +kind of account for taking those days + + + align:start position:0% +kind of account for taking those days +off because they're not running at full + + align:start position:0% +off because they're not running at full + + + align:start position:0% +off because they're not running at full +capacity all the time anyway the case + + align:start position:0% +capacity all the time anyway the case + + + align:start position:0% +capacity all the time anyway the case +the case leads you to some optimism yes + + align:start position:0% +the case leads you to some optimism yes + + + align:start position:0% +the case leads you to some optimism yes +um and + + align:start position:0% +um and + + + align:start position:0% +um and +then I mean additionally you can just go + + align:start position:0% +then I mean additionally you can just go + + + align:start position:0% +then I mean additionally you can just go +back to the handy argument that + + align:start position:0% +back to the handy argument that + + + align:start position:0% +back to the handy argument that +businesses need to produce money but + + align:start position:0% +businesses need to produce money but + + + align:start position:0% +businesses need to produce money but +they don't necessarily need to maximize + + align:start position:0% +they don't necessarily need to maximize + + + align:start position:0% +they don't necessarily need to maximize +their funding we can do this because but + + align:start position:0% +their funding we can do this because but + + + align:start position:0% +their funding we can do this because but +this isn't about this this last point + + align:start position:0% +this isn't about this this last point + + + align:start position:0% +this isn't about this this last point +isn't about the business it's about my + + align:start position:0% +isn't about the business it's about my + + + align:start position:0% +isn't about the business it's about my +trip to the Caribbean + + align:start position:0% + + + + align:start position:0% + +care about + + align:start position:0% +care about + + + align:start position:0% +care about +that this one's tough I don't mean to + + align:start position:0% +that this one's tough I don't mean to + + + align:start position:0% +that this one's tough I don't mean to +put you particularly on the spot but + + align:start position:0% +put you particularly on the spot but + + + align:start position:0% +put you particularly on the spot but +this one's tough if you've got the + + align:start position:0% +this one's tough if you've got the + + + align:start position:0% +this one's tough if you've got the +compensation structure set in such a way + + align:start position:0% +compensation structure set in such a way + + + align:start position:0% +compensation structure set in such a way +that it biases toward growth and towards + + align:start position:0% +that it biases toward growth and towards + + + align:start position:0% +that it biases toward growth and towards +Revenue this is a tough one Charlotte + + align:start position:0% +Revenue this is a tough one Charlotte + + + align:start position:0% +Revenue this is a tough one Charlotte +you could go back to the point that we + + align:start position:0% +you could go back to the point that we + + + align:start position:0% +you could go back to the point that we +made on the the last objection where if + + align:start position:0% +made on the the last objection where if + + + align:start position:0% +made on the the last objection where if +you know you're the first plant to start + + align:start position:0% +you know you're the first plant to start + + + align:start position:0% +you know you're the first plant to start +uh something that saves your company 2% + + align:start position:0% +uh something that saves your company 2% + + + align:start position:0% +uh something that saves your company 2% +in revenue and it happens to other + + align:start position:0% +in revenue and it happens to other + + + align:start position:0% +in revenue and it happens to other +plants in + + align:start position:0% +plants in + + + align:start position:0% +plants in +organ the heads of organization will + + align:start position:0% +organ the heads of organization will + + + align:start position:0% +organ the heads of organization will +look favly on you and in + + align:start position:0% + + + + align:start position:0% + +later we can get a bigger bonus if we + + align:start position:0% +later we can get a bigger bonus if we + + + align:start position:0% +later we can get a bigger bonus if we +can sell + + align:start position:0% +can sell + + + align:start position:0% +can sell +this tough argument it's one you'd try + + align:start position:0% +this tough argument it's one you'd try + + + align:start position:0% +this tough argument it's one you'd try +though David you also get a promotion if + + align:start position:0% +though David you also get a promotion if + + + align:start position:0% +though David you also get a promotion if +you can demonstrate initiative and + + align:start position:0% +you can demonstrate initiative and + + + align:start position:0% +you can demonstrate initiative and +larger scale thinking and if you don't + + align:start position:0% +larger scale thinking and if you don't + + + align:start position:0% +larger scale thinking and if you don't +do it and someone else implements it + + align:start position:0% +do it and someone else implements it + + + align:start position:0% +do it and someone else implements it +they might displace + + align:start position:0% +they might displace + + + align:start position:0% +they might displace +you it works for Dar it might not work + + align:start position:0% +you it works for Dar it might not work + + + align:start position:0% +you it works for Dar it might not work +for the guys one notch above Darren it + + align:start position:0% +for the guys one notch above Darren it + + + align:start position:0% +for the guys one notch above Darren it +might though it might look if you guys + + align:start position:0% +might though it might look if you guys + + + align:start position:0% +might though it might look if you guys +all get behind this we'll all ride up + + align:start position:0% +all get behind this we'll all ride up + + + align:start position:0% +all get behind this we'll all ride up +right up the ladder together Martha um + + align:start position:0% +right up the ladder together Martha um + + + align:start position:0% +right up the ladder together Martha um +going back to what was said about how + + align:start position:0% +going back to what was said about how + + + align:start position:0% +going back to what was said about how +after your investment was returned + + align:start position:0% +after your investment was returned + + + align:start position:0% +after your investment was returned +you'll be continuing to save money so + + align:start position:0% +you'll be continuing to save money so + + + align:start position:0% +you'll be continuing to save money so +youron us may be less this year but it + + align:start position:0% +youron us may be less this year but it + + + align:start position:0% +youron us may be less this year but it +may be much greater in future years when + + align:start position:0% +may be much greater in future years when + + + align:start position:0% +may be much greater in future years when +we're able to start expanding that grow + + align:start position:0% +we're able to start expanding that grow + + + align:start position:0% +we're able to start expanding that grow +we're able to start so maybe instead of + + align:start position:0% +we're able to start so maybe instead of + + + align:start position:0% +we're able to start so maybe instead of +going to the Caribbean this year you go + + align:start position:0% +going to the Caribbean this year you go + + + align:start position:0% +going to the Caribbean this year you go +to + + align:start position:0% +to + + + align:start position:0% +to +bail or + + align:start position:0% +bail or + + + align:start position:0% +bail or +something but five years down the road + + align:start position:0% +something but five years down the road + + + align:start position:0% +something but five years down the road +you could go to Jurassic Park I don't + + align:start position:0% +you could go to Jurassic Park I don't + + + align:start position:0% +you could go to Jurassic Park I don't +know they ski in the adx instead of + + align:start position:0% +know they ski in the adx instead of + + + align:start position:0% +know they ski in the adx instead of +skiing in Vermont I don't know okay um + + align:start position:0% +skiing in Vermont I don't know okay um + + + align:start position:0% +skiing in Vermont I don't know okay um +anybody + + align:start position:0% +anybody + + + align:start position:0% +anybody +else + + align:start position:0% +else + + + align:start position:0% +else +okay + + align:start position:0% + + + + align:start position:0% + +um how about that the case talks about + + align:start position:0% +um how about that the case talks about + + + align:start position:0% +um how about that the case talks about +all these policies there's this kill + + align:start position:0% +all these policies there's this kill + + + align:start position:0% +all these policies there's this kill +switch + + align:start position:0% +switch + + + align:start position:0% +switch +problem uh there are other polic I about + + align:start position:0% +problem uh there are other polic I about + + + align:start position:0% +problem uh there are other polic I about +interconnection they're still in flux + + align:start position:0% +interconnection they're still in flux + + + align:start position:0% +interconnection they're still in flux +maybe what we ought to do it's good idea + + align:start position:0% +maybe what we ought to do it's good idea + + + align:start position:0% +maybe what we ought to do it's good idea +okay you've sold me it's a good idea why + + align:start position:0% +okay you've sold me it's a good idea why + + + align:start position:0% +okay you've sold me it's a good idea why +don't we just + + align:start position:0% +don't we just + + + align:start position:0% +don't we just +wait let's just let this stuff + + align:start position:0% + + + + align:start position:0% + +settle you know maybe they'll maybe if + + align:start position:0% +settle you know maybe they'll maybe if + + + align:start position:0% +settle you know maybe they'll maybe if +we do it now we'll have to take + + align:start position:0% +we do it now we'll have to take + + + align:start position:0% +we do it now we'll have to take +precautions we wouldn't have to take if + + align:start position:0% +precautions we wouldn't have to take if + + + align:start position:0% +precautions we wouldn't have to take if +they apply more sensible policies down + + align:start position:0% +they apply more sensible policies down + + + align:start position:0% +they apply more sensible policies down +the + + align:start position:0% +the + + + align:start position:0% +the +road David you none of the competitors + + align:start position:0% +road David you none of the competitors + + + align:start position:0% +road David you none of the competitors +are doing it now so doing it now us a + + align:start position:0% +are doing it now so doing it now us a + + + align:start position:0% +are doing it now so doing it now us a +competitive Advantage versus in the + + align:start position:0% +competitive Advantage versus in the + + + align:start position:0% +competitive Advantage versus in the +future compe have already introduced + + align:start position:0% +future compe have already introduced + + + align:start position:0% +future compe have already introduced +itat well we are but suppose the policy + + align:start position:0% +itat well we are but suppose the policy + + + align:start position:0% +itat well we are but suppose the policy +goes against us suppose instead of + + align:start position:0% +goes against us suppose instead of + + + align:start position:0% +goes against us suppose instead of +making it easier to interconnect that + + align:start position:0% +making it easier to interconnect that + + + align:start position:0% +making it easier to interconnect that +the policy change makes it harder + + align:start position:0% +the policy change makes it harder + + + align:start position:0% +the policy change makes it harder +requires us to put on more protective + + align:start position:0% +requires us to put on more protective + + + align:start position:0% +requires us to put on more protective +devices or let's say $200,000 worth uh + + align:start position:0% +devices or let's say $200,000 worth uh + + + align:start position:0% +devices or let's say $200,000 worth uh +and then all of a sudden it's that's + + align:start position:0% +and then all of a sudden it's that's + + + align:start position:0% +and then all of a sudden it's that's +that's extreme but + + align:start position:0% +that's extreme but + + + align:start position:0% +that's extreme but +but uh all of a sudden the policies we + + align:start position:0% +but uh all of a sudden the policies we + + + align:start position:0% +but uh all of a sudden the policies we +were counting on the ability to sell + + align:start position:0% +were counting on the ability to sell + + + align:start position:0% +were counting on the ability to sell +Excess power which is still in flux at + + align:start position:0% +Excess power which is still in flux at + + + align:start position:0% +Excess power which is still in flux at +this point um turns out we can't sell it + + align:start position:0% +this point um turns out we can't sell it + + + align:start position:0% +this point um turns out we can't sell it +turns out we need to have more + + align:start position:0% +turns out we need to have more + + + align:start position:0% +turns out we need to have more +protection maybe we should + + align:start position:0% +protection maybe we should + + + align:start position:0% +protection maybe we should +wait Claudia what do you + + align:start position:0% +wait Claudia what do you + + + align:start position:0% +wait Claudia what do you +say you sold you sold with the Skeptics + + align:start position:0% +say you sold you sold with the Skeptics + + + align:start position:0% +say you sold you sold with the Skeptics +I mean that's not a crazy point + + align:start position:0% +I mean that's not a crazy point + + + align:start position:0% +I mean that's not a crazy point +no is it is there a chance to like + + align:start position:0% +no is it is there a chance to like + + + align:start position:0% +no is it is there a chance to like +approach local Regulators directly and + + align:start position:0% +approach local Regulators directly and + + + align:start position:0% +approach local Regulators directly and +just make + + align:start position:0% +just make + + + align:start position:0% +just make +it well one thing Darren might have done + + align:start position:0% +it well one thing Darren might have done + + + align:start position:0% +it well one thing Darren might have done +is he might have not necessarily + + align:start position:0% +is he might have not necessarily + + + align:start position:0% +is he might have not necessarily +approached them but he might try to get + + align:start position:0% +approached them but he might try to get + + + align:start position:0% +approached them but he might try to get +a feel from say his local representative + + align:start position:0% +a feel from say his local representative + + + align:start position:0% +a feel from say his local representative +a lot of this stuff is going on at the + + align:start position:0% +a lot of this stuff is going on at the + + + align:start position:0% +a lot of this stuff is going on at the +state + + align:start position:0% +state + + + align:start position:0% +state +level he's running a pretty big pretty + + align:start position:0% +level he's running a pretty big pretty + + + align:start position:0% +level he's running a pretty big pretty +big operation he's one of the great + + align:start position:0% +big operation he's one of the great + + + align:start position:0% +big operation he's one of the great +polluters no one of the great great + + align:start position:0% +polluters no one of the great great + + + align:start position:0% +polluters no one of the great great +operations in the area might make a + + align:start position:0% +operations in the area might make a + + + align:start position:0% +operations in the area might make a +phone call and say look can you tell me + + align:start position:0% +phone call and say look can you tell me + + + align:start position:0% +phone call and say look can you tell me +where this stuff stands I mean are we + + align:start position:0% +where this stuff stands I mean are we + + + align:start position:0% +where this stuff stands I mean are we +going to get we going to is it going to + + align:start position:0% +going to get we going to is it going to + + + align:start position:0% +going to get we going to is it going to +get resolved in 6 months or is this a + + align:start position:0% +get resolved in 6 months or is this a + + + align:start position:0% +get resolved in 6 months or is this a +5year marathon and it'll get changed + + align:start position:0% +5year marathon and it'll get changed + + + align:start position:0% +5year marathon and it'll get changed +every so often that matters if it's + + align:start position:0% +every so often that matters if it's + + + align:start position:0% +every so often that matters if it's +going to get resolved in six months + + align:start position:0% +going to get resolved in six months + + + align:start position:0% +going to get resolved in six months +let's wait if it's if it's going to be + + align:start position:0% +let's wait if it's if it's going to be + + + align:start position:0% +let's wait if it's if it's going to be +debated for the next 10 years why wait + + align:start position:0% +debated for the next 10 years why wait + + + align:start position:0% +debated for the next 10 years why wait +Ariana I think this is where it would + + align:start position:0% +Ariana I think this is where it would + + + align:start position:0% +Ariana I think this is where it would +have come in useful for him to have made + + align:start position:0% +have come in useful for him to have made + + + align:start position:0% +have come in useful for him to have made +a more pessimistic analysis um and so + + align:start position:0% +a more pessimistic analysis um and so + + + align:start position:0% +a more pessimistic analysis um and so +maybe you know you do that first and + + align:start position:0% +maybe you know you do that first and + + + align:start position:0% +maybe you know you do that first and +then you say like okay well um because I + + align:start position:0% +then you say like okay well um because I + + + align:start position:0% +then you say like okay well um because I +mean when we looked at it it looked like + + align:start position:0% +mean when we looked at it it looked like + + + align:start position:0% +mean when we looked at it it looked like +even if some of the um estimates were a + + align:start position:0% +even if some of the um estimates were a + + + align:start position:0% +even if some of the um estimates were a +little bit more pessimistic or you + + align:start position:0% +little bit more pessimistic or you + + + align:start position:0% +little bit more pessimistic or you +couldn't get the grant that you wanted + + align:start position:0% +couldn't get the grant that you wanted + + + align:start position:0% +couldn't get the grant that you wanted +maybe um or you like estimated it with + + align:start position:0% +maybe um or you like estimated it with + + + align:start position:0% +maybe um or you like estimated it with +some of the policies not falling your + + align:start position:0% +some of the policies not falling your + + + align:start position:0% +some of the policies not falling your +way and you could still maybe like the + + align:start position:0% +way and you could still maybe like the + + + align:start position:0% +way and you could still maybe like the +profit wouldn't be as large but in the + + align:start position:0% +profit wouldn't be as large but in the + + + align:start position:0% +profit wouldn't be as large but in the +long run it's still worth it then you + + align:start position:0% +long run it's still worth it then you + + + align:start position:0% +long run it's still worth it then you +could come and say like look this is + + align:start position:0% +could come and say like look this is + + + align:start position:0% +could come and say like look this is +what I think is going to happen but even + + align:start position:0% +what I think is going to happen but even + + + align:start position:0% +what I think is going to happen but even +if I mean you never really know and even + + align:start position:0% +if I mean you never really know and even + + + align:start position:0% +if I mean you never really know and even +if it goes a little bit sour like we + + align:start position:0% +if it goes a little bit sour like we + + + align:start position:0% +if it goes a little bit sour like we +still are making some kind of profit so + + align:start position:0% +still are making some kind of profit so + + + align:start position:0% +still are making some kind of profit so +like it's it's worth it + + align:start position:0% +like it's it's worth it + + + align:start position:0% +like it's it's worth it +anyway okay let me go to one last one + + align:start position:0% +anyway okay let me go to one last one + + + align:start position:0% +anyway okay let me go to one last one +who'd like to make the elevator + + align:start position:0% +who'd like to make the elevator + + + align:start position:0% +who'd like to make the elevator +pitch is there a spin he can put on this + + align:start position:0% +pitch is there a spin he can put on this + + + align:start position:0% +pitch is there a spin he can put on this +so so he's he walked in with his + + align:start position:0% +so so he's he walked in with his + + + align:start position:0% +so so he's he walked in with his +spreadsheet he got all these arguments + + align:start position:0% +spreadsheet he got all these arguments + + + align:start position:0% +spreadsheet he got all these arguments +all these naysaying + + align:start position:0% +all these naysaying + + + align:start position:0% +all these naysaying +nitpickers what do you stand up and + + align:start position:0% +nitpickers what do you stand up and + + + align:start position:0% +nitpickers what do you stand up and +say what do you stand up and say + + align:start position:0% +say what do you stand up and say + + + align:start position:0% +say what do you stand up and say +Caroline are you ready with an elevator + + align:start position:0% +Caroline are you ready with an elevator + + + align:start position:0% +Caroline are you ready with an elevator +pitch here you ready with a one minute + + align:start position:0% +pitch here you ready with a one minute + + + align:start position:0% +pitch here you ready with a one minute +speech to to make the committee turn + + align:start position:0% +speech to to make the committee turn + + + align:start position:0% +speech to to make the committee turn +around and charge out the door and go to + + align:start position:0% +around and charge out the door and go to + + + align:start position:0% +around and charge out the door and go to +the CEO and do + + align:start position:0% + + + + align:start position:0% + +it not quite ready okay anybody AA + + align:start position:0% +it not quite ready okay anybody AA + + + align:start position:0% +it not quite ready okay anybody AA +you're ready today okay that's good so + + align:start position:0% +you're ready today okay that's good so + + + align:start position:0% +you're ready today okay that's good so +uh sorry to disappoint you I don't have + + align:start position:0% +uh sorry to disappoint you I don't have + + + align:start position:0% +uh sorry to disappoint you I don't have +an elevator pitch but I'm I'm curious as + + align:start position:0% +an elevator pitch but I'm I'm curious as + + + align:start position:0% +an elevator pitch but I'm I'm curious as +to what the outcome was of this case + + align:start position:0% +to what the outcome was of this case + + + align:start position:0% +to what the outcome was of this case +because it's just not these AR let me + + align:start position:0% +because it's just not these AR let me + + + align:start position:0% +because it's just not these AR let me +fish one more time for an elevator pitch + + align:start position:0% +fish one more time for an elevator pitch + + + align:start position:0% +fish one more time for an elevator pitch +and then I'll and then I'll tell you + + align:start position:0% +and then I'll and then I'll tell you + + + align:start position:0% +and then I'll and then I'll tell you +what I think happened which is not + + align:start position:0% +what I think happened which is not + + + align:start position:0% +what I think happened which is not +unrelated to that question Max um you + + align:start position:0% +unrelated to that question Max um you + + + align:start position:0% +unrelated to that question Max um you +want to appeal to the interest of the + + align:start position:0% +want to appeal to the interest of the + + + align:start position:0% +want to appeal to the interest of the +board and their interest is obviously + + align:start position:0% +board and their interest is obviously + + + align:start position:0% +board and their interest is obviously +production and maximizing profit so + + align:start position:0% +production and maximizing profit so + + + align:start position:0% +production and maximizing profit so +emphasizing the fact that this + + align:start position:0% +emphasizing the fact that this + + + align:start position:0% +emphasizing the fact that this +short-term investment will save a lot of + + align:start position:0% +short-term investment will save a lot of + + + align:start position:0% +short-term investment will save a lot of +money in the long run which you can in + + align:start position:0% +money in the long run which you can in + + + align:start position:0% +money in the long run which you can in +turn invest in Creer production in the + + align:start position:0% +turn invest in Creer production in the + + + align:start position:0% +turn invest in Creer production in the +future which will give them bigger + + align:start position:0% +future which will give them bigger + + + align:start position:0% +future which will give them bigger +bonuses you could also appeal I think + + align:start position:0% +bonuses you could also appeal I think + + + align:start position:0% +bonuses you could also appeal I think +for it deals with a couple of points to + + align:start position:0% +for it deals with a couple of points to + + + align:start position:0% +for it deals with a couple of points to +the safety of the workers and to the + + align:start position:0% +the safety of the workers and to the + + + align:start position:0% +the safety of the workers and to the +Integrity of the whole plan so know in + + align:start position:0% +Integrity of the whole plan so know in + + + align:start position:0% +Integrity of the whole plan so know in +the article it talked about the ice + + align:start position:0% +the article it talked about the ice + + + align:start position:0% +the article it talked about the ice +being a hazard for the workers and the + + align:start position:0% +being a hazard for the workers and the + + + align:start position:0% +being a hazard for the workers and the +corosion of some of the uh structure of + + align:start position:0% +corosion of some of the uh structure of + + + align:start position:0% +corosion of some of the uh structure of +the building spin it that way as well + + align:start position:0% +the building spin it that way as well + + + align:start position:0% +the building spin it that way as well +what I think happened and it's not + + align:start position:0% +what I think happened and it's not + + + align:start position:0% +what I think happened and it's not +unrelated to that my my understanding + + align:start position:0% +unrelated to that my my understanding + + + align:start position:0% +unrelated to that my my understanding +and I've tried to verify it and I'll see + + align:start position:0% +and I've tried to verify it and I'll see + + + align:start position:0% +and I've tried to verify it and I'll see +if I can do it next time um is that in + + align:start position:0% +if I can do it next time um is that in + + + align:start position:0% +if I can do it next time um is that in +fact when he presented it to the review + + align:start position:0% +fact when he presented it to the review + + + align:start position:0% +fact when he presented it to the review +operation it was turned down for sort of + + align:start position:0% +operation it was turned down for sort of + + + align:start position:0% +operation it was turned down for sort of +all of those + + align:start position:0% +all of those + + + align:start position:0% +all of those +reasons uh and he + + align:start position:0% +reasons uh and he + + + align:start position:0% +reasons uh and he +managed uh to get the ear one way or + + align:start position:0% +managed uh to get the ear one way or + + + align:start position:0% +managed uh to get the ear one way or +another of the CEO when he pitched it as + + align:start position:0% +another of the CEO when he pitched it as + + + align:start position:0% +another of the CEO when he pitched it as +industry + + align:start position:0% +industry + + + align:start position:0% +industry +leadership green public relations + + align:start position:0% +leadership green public relations + + + align:start position:0% +leadership green public relations +economics are okay economics are pretty + + align:start position:0% +economics are okay economics are pretty + + + align:start position:0% +economics are okay economics are pretty +good uh so you don't we're not going to + + align:start position:0% +good uh so you don't we're not going to + + + align:start position:0% +good uh so you don't we're not going to +lose money on this investment but + + align:start position:0% +lose money on this investment but + + + align:start position:0% +lose money on this investment but +moreover think about what we can say to + + align:start position:0% +moreover think about what we can say to + + + align:start position:0% +moreover think about what we can say to +the community think about what we can + + align:start position:0% +the community think about what we can + + + align:start position:0% +the community think about what we can +say to the workers think about what you + + align:start position:0% +say to the workers think about what you + + + align:start position:0% +say to the workers think about what you +can say at the next industry convention + + align:start position:0% +can say at the next industry convention + + + align:start position:0% +can say at the next industry convention +when you stand up and give your + + align:start position:0% +when you stand up and give your + + + align:start position:0% +when you stand up and give your +leadership + + align:start position:0% +leadership + + + align:start position:0% +leadership +speech um we'll get benefits I mean + + align:start position:0% +speech um we'll get benefits I mean + + + align:start position:0% +speech um we'll get benefits I mean +we're vetting steam it's not hurting + + align:start position:0% +we're vetting steam it's not hurting + + + align:start position:0% +we're vetting steam it's not hurting +anybody but it doesn't look good it's + + align:start position:0% +anybody but it doesn't look good it's + + + align:start position:0% +anybody but it doesn't look good it's +going to look better so he went around + + align:start position:0% +going to look better so he went around + + + align:start position:0% +going to look better so he went around +these guys is my understanding and + + align:start position:0% +these guys is my understanding and + + + align:start position:0% +these guys is my understanding and +pitched it as an + + align:start position:0% +pitched it as an + + + align:start position:0% +pitched it as an +opportunity as an and not just an + + align:start position:0% +opportunity as an and not just an + + + align:start position:0% +opportunity as an and not just an +Economic Opportunity he he overstated + + align:start position:0% +Economic Opportunity he he overstated + + + align:start position:0% +Economic Opportunity he he overstated +the economics economics are + + align:start position:0% +the economics economics are + + + align:start position:0% +the economics economics are +okay but he pitched it as an opportunity + + align:start position:0% +okay but he pitched it as an opportunity + + + align:start position:0% +okay but he pitched it as an opportunity +and we'll see next week and we will see + + align:start position:0% +and we'll see next week and we will see + + + align:start position:0% +and we'll see next week and we will see +after the vacation that whether you view + + align:start position:0% +after the vacation that whether you view + + + align:start position:0% +after the vacation that whether you view +something as a threat or an oper + + align:start position:0% +something as a threat or an oper + + + align:start position:0% +something as a threat or an oper +opportunity makes a lot of difference as + + align:start position:0% +opportunity makes a lot of difference as + + + align:start position:0% +opportunity makes a lot of difference as +to how you act on it thank you very much \ No newline at end of file diff --git a/YD7QG4G7WVg.txt b/YD7QG4G7WVg.txt new file mode 100644 index 0000000000000000000000000000000000000000..4de88593620a2805bafc80eb7a2679328ab908a9 --- /dev/null +++ b/YD7QG4G7WVg.txt @@ -0,0 +1,16368 @@ +align:start position:0% + +all right 1105 let's get started so the + + align:start position:0% +all right 1105 let's get started so the + + + align:start position:0% +all right 1105 let's get started so the +agenda for today we're doing this whole + + align:start position:0% +agenda for today we're doing this whole + + + align:start position:0% +agenda for today we're doing this whole +thing on the methods in human cognitive + + align:start position:0% +thing on the methods in human cognitive + + + align:start position:0% +thing on the methods in human cognitive +neuroscience and i'm illustrating those + + align:start position:0% +neuroscience and i'm illustrating those + + + align:start position:0% +neuroscience and i'm illustrating those +methods with the case of face perception + + align:start position:0% +methods with the case of face perception + + + align:start position:0% +methods with the case of face perception +not just because i'm into face + + align:start position:0% +not just because i'm into face + + + align:start position:0% +not just because i'm into face +perception but it's like a particularly + + align:start position:0% +perception but it's like a particularly + + + align:start position:0% +perception but it's like a particularly +rich + + align:start position:0% +rich + + + align:start position:0% +rich +domain of research where there's lots + + align:start position:0% +domain of research where there's lots + + + align:start position:0% +domain of research where there's lots +lots to say about it from all these + + align:start position:0% +lots to say about it from all these + + + align:start position:0% +lots to say about it from all these +different methods and so last time we + + align:start position:0% +different methods and so last time we + + + align:start position:0% +different methods and so last time we +talked a bit about applying mars + + align:start position:0% +talked a bit about applying mars + + + align:start position:0% +talked a bit about applying mars +computational theory level to face + + align:start position:0% +computational theory level to face + + + align:start position:0% +computational theory level to face +perception we talked a teeny bit about + + align:start position:0% +perception we talked a teeny bit about + + + align:start position:0% +perception we talked a teeny bit about +some behavioral data and a little bit + + align:start position:0% +some behavioral data and a little bit + + + align:start position:0% +some behavioral data and a little bit +about functional mri what i'm going to + + align:start position:0% +about functional mri what i'm going to + + + align:start position:0% +about functional mri what i'm going to +do today is quickly zoom through + + align:start position:0% +do today is quickly zoom through + + + align:start position:0% +do today is quickly zoom through +speed speeded-up review of those things + + align:start position:0% +speed speeded-up review of those things + + + align:start position:0% +speed speeded-up review of those things +and then we're going to get to some of + + align:start position:0% +and then we're going to get to some of + + + align:start position:0% +and then we're going to get to some of +these other methods and there's a quiz + + align:start position:0% +these other methods and there's a quiz + + + align:start position:0% +these other methods and there's a quiz +at the end all right + + align:start position:0% +at the end all right + + + align:start position:0% +at the end all right +okay so um + + align:start position:0% +okay so um + + + align:start position:0% +okay so um +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +methods in + + align:start position:0% +methods in + + + align:start position:0% +methods in +in any field of science are just there + + align:start position:0% +in any field of science are just there + + + align:start position:0% +in any field of science are just there +to enable us to answer scientific + + align:start position:0% +to enable us to answer scientific + + + align:start position:0% +to enable us to answer scientific +questions they're not to you know + + align:start position:0% +questions they're not to you know + + + align:start position:0% +questions they're not to you know +impress our friends with all the fancy + + align:start position:0% +impress our friends with all the fancy + + + align:start position:0% +impress our friends with all the fancy +things we know how to do or our + + align:start position:0% +things we know how to do or our + + + align:start position:0% +things we know how to do or our +colleagues + + align:start position:0% +colleagues + + + align:start position:0% +colleagues +they're just to answer questions and so + + align:start position:0% +they're just to answer questions and so + + + align:start position:0% +they're just to answer questions and so +you always have to start with the + + align:start position:0% +you always have to start with the + + + align:start position:0% +you always have to start with the +questions and so last time i listed a + + align:start position:0% +questions and so last time i listed a + + + align:start position:0% +questions and so last time i listed a +bunch of questions not all of them but a + + align:start position:0% +bunch of questions not all of them but a + + + align:start position:0% +bunch of questions not all of them but a +bunch of questions one would really want + + align:start position:0% +bunch of questions one would really want + + + align:start position:0% +bunch of questions one would really want +to know about face perception if we were + + align:start position:0% +to know about face perception if we were + + + align:start position:0% +to know about face perception if we were +to understand how it works in the brain + + align:start position:0% +to understand how it works in the brain + + + align:start position:0% +to understand how it works in the brain +and last time we focused on these first + + align:start position:0% +and last time we focused on these first + + + align:start position:0% +and last time we focused on these first +three so let me just do super quick + + align:start position:0% +three so let me just do super quick + + + align:start position:0% +three so let me just do super quick +review + + align:start position:0% +review + + + align:start position:0% +review +questions at the level of mars + + align:start position:0% +questions at the level of mars + + + align:start position:0% +questions at the level of mars +computational theory we ask + + align:start position:0% +computational theory we ask + + + align:start position:0% +computational theory we ask +what is the problem that's being solved + + align:start position:0% +what is the problem that's being solved + + + align:start position:0% +what is the problem that's being solved +and why is that important to the + + align:start position:0% +and why is that important to the + + + align:start position:0% +and why is that important to the +organism + + align:start position:0% +organism + + + align:start position:0% +organism +what is the input what is the output how + + align:start position:0% +what is the input what is the output how + + + align:start position:0% +what is the input what is the output how +much you get from that input to that + + align:start position:0% +much you get from that input to that + + + align:start position:0% +much you get from that input to that +output right so for the case of face + + align:start position:0% +output right so for the case of face + + + align:start position:0% +output right so for the case of face +perception here's a very simple version + + align:start position:0% +perception here's a very simple version + + + align:start position:0% +perception here's a very simple version +of it here's an example of the input + + align:start position:0% +of it here's an example of the input + + + align:start position:0% +of it here's an example of the input +goes in hits the retina + + align:start position:0% +goes in hits the retina + + + align:start position:0% +goes in hits the retina +the stuff that we want to understand + + align:start position:0% +the stuff that we want to understand + + + align:start position:0% +the stuff that we want to understand +happens in here and you have an output + + align:start position:0% +happens in here and you have an output + + + align:start position:0% +happens in here and you have an output +okay so just even thinking about it that + + align:start position:0% +okay so just even thinking about it that + + + align:start position:0% +okay so just even thinking about it that +way + + align:start position:0% +way + + + align:start position:0% +way +we can already just see with common + + align:start position:0% +we can already just see with common + + + align:start position:0% +we can already just see with common +sense that one of the big challenges in + + align:start position:0% +sense that one of the big challenges in + + + align:start position:0% +sense that one of the big challenges in +solving this problem + + align:start position:0% +solving this problem + + + align:start position:0% +solving this problem +is that faces look different every time + + align:start position:0% +is that faces look different every time + + + align:start position:0% +is that faces look different every time +you see them + + align:start position:0% +you see them + + + align:start position:0% +you see them +the lighting changes the orientation of + + align:start position:0% +the lighting changes the orientation of + + + align:start position:0% +the lighting changes the orientation of +the face changes the hair changes the + + align:start position:0% +the face changes the hair changes the + + + align:start position:0% +the face changes the hair changes the +mood changes all this stuff happens + + align:start position:0% +mood changes all this stuff happens + + + align:start position:0% +mood changes all this stuff happens +people put on makeup they shave off + + align:start position:0% +people put on makeup they shave off + + + align:start position:0% +people put on makeup they shave off +their facial hair they do all these + + align:start position:0% +their facial hair they do all these + + + align:start position:0% +their facial hair they do all these +things to make it a real a big challenge + + align:start position:0% +things to make it a real a big challenge + + + align:start position:0% +things to make it a real a big challenge +to recognize faces and yet we manage + + align:start position:0% +to recognize faces and yet we manage + + + align:start position:0% +to recognize faces and yet we manage +really well so how do we do that + + align:start position:0% +really well so how do we do that + + + align:start position:0% +really well so how do we do that +well our field has many methods to + + align:start position:0% +well our field has many methods to + + + align:start position:0% +well our field has many methods to +address this question + + align:start position:0% +address this question + + + align:start position:0% +address this question +last time i talked about one little + + align:start position:0% +last time i talked about one little + + + align:start position:0% +last time i talked about one little +example of a behavioral study simple + + align:start position:0% +example of a behavioral study simple + + + align:start position:0% +example of a behavioral study simple +cognitive psychology study measuring + + align:start position:0% +cognitive psychology study measuring + + + align:start position:0% +cognitive psychology study measuring +behavior + + align:start position:0% +behavior + + + align:start position:0% +behavior +where we showed that + + align:start position:0% +where we showed that + + + align:start position:0% +where we showed that +that the way people solve this problem + + align:start position:0% +that the way people solve this problem + + + align:start position:0% +that the way people solve this problem +is fundamentally different with people + + align:start position:0% +is fundamentally different with people + + + align:start position:0% +is fundamentally different with people +they know well and people they don't + + align:start position:0% +they know well and people they don't + + + align:start position:0% +they know well and people they don't +know well + + align:start position:0% +know well + + + align:start position:0% +know well +so i showed an example that you know all + + align:start position:0% +so i showed an example that you know all + + + align:start position:0% +so i showed an example that you know all +of you presumably would have no trouble + + align:start position:0% +of you presumably would have no trouble + + + align:start position:0% +of you presumably would have no trouble +saying determining that those are all + + align:start position:0% +saying determining that those are all + + + align:start position:0% +saying determining that those are all +pictures of the same person even though + + align:start position:0% +pictures of the same person even though + + + align:start position:0% +pictures of the same person even though +the pics at the pixel level they're + + align:start position:0% +the pics at the pixel level they're + + + align:start position:0% +the pics at the pixel level they're +wildly different + + align:start position:0% +wildly different + + + align:start position:0% +wildly different +and yet you have a hell of a time saying + + align:start position:0% +and yet you have a hell of a time saying + + + align:start position:0% +and yet you have a hell of a time saying +which of those images are of the same + + align:start position:0% +which of those images are of the same + + + align:start position:0% +which of those images are of the same +people and which aren't and so the point + + align:start position:0% +people and which aren't and so the point + + + align:start position:0% +people and which aren't and so the point +is that our ability to extract this + + align:start position:0% +is that our ability to extract this + + + align:start position:0% +is that our ability to extract this +invariant representation that is to + + align:start position:0% +invariant representation that is to + + + align:start position:0% +invariant representation that is to +figure out abstractly who is that + + align:start position:0% +figure out abstractly who is that + + + align:start position:0% +figure out abstractly who is that +um + + align:start position:0% +um + + + align:start position:0% +um +uh is really well to figure out that any + + align:start position:0% +uh is really well to figure out that any + + + align:start position:0% +uh is really well to figure out that any +any of these images are the same as each + + align:start position:0% +any of these images are the same as each + + + align:start position:0% +any of these images are the same as each +other is much better for familiar than + + align:start position:0% +other is much better for familiar than + + + align:start position:0% +other is much better for familiar than +unfamiliar faces and that means we don't + + align:start position:0% +unfamiliar faces and that means we don't + + + align:start position:0% +unfamiliar faces and that means we don't +have a perfectly general ability to take + + align:start position:0% +have a perfectly general ability to take + + + align:start position:0% +have a perfectly general ability to take +any face and abstract out this + + align:start position:0% +any face and abstract out this + + + align:start position:0% +any face and abstract out this +completely of + + align:start position:0% +completely of + + + align:start position:0% +completely of +image independent version of it that's + + align:start position:0% +image independent version of it that's + + + align:start position:0% +image independent version of it that's +what invariant representation is yeah + + align:start position:0% +what invariant representation is yeah + + + align:start position:0% +what invariant representation is yeah +for the case of the dutch politicians + + align:start position:0% +for the case of the dutch politicians + + + align:start position:0% +for the case of the dutch politicians +did they like ever do this study on + + align:start position:0% +did they like ever do this study on + + + align:start position:0% +did they like ever do this study on +people who are like super + + align:start position:0% +people who are like super + + + align:start position:0% +people who are like super +recognizers uh i don't know about that + + align:start position:0% +recognizers uh i don't know about that + + + align:start position:0% +recognizers uh i don't know about that +but they did do it on um + + align:start position:0% +but they did do it on um + + + align:start position:0% +but they did do it on um +uh people who are professional + + align:start position:0% +uh people who are professional + + + align:start position:0% +uh people who are professional +um + + align:start position:0% +um + + + align:start position:0% +um +uh you know tsa type people + + align:start position:0% +uh you know tsa type people + + + align:start position:0% +uh you know tsa type people +right and i'll tell you guys about that + + align:start position:0% +right and i'll tell you guys about that + + + align:start position:0% +right and i'll tell you guys about that +later but you could think about you know + + align:start position:0% +later but you could think about you know + + + align:start position:0% +later but you could think about you know +you could think about whether you think + + align:start position:0% +you could think about whether you think + + + align:start position:0% +you could think about whether you think +it might work better with those people + + align:start position:0% +it might work better with those people + + + align:start position:0% +it might work better with those people +or not + + align:start position:0% + + + + align:start position:0% + +okay everybody get this general point + + align:start position:0% +okay everybody get this general point + + + align:start position:0% +okay everybody get this general point +here all right + + align:start position:0% +here all right + + + align:start position:0% +here all right +so i i skipped over another simple + + align:start position:0% +so i i skipped over another simple + + + align:start position:0% +so i i skipped over another simple +behavioral finding last time that i want + + align:start position:0% +behavioral finding last time that i want + + + align:start position:0% +behavioral finding last time that i want +to mention now + + align:start position:0% +to mention now + + + align:start position:0% +to mention now +and that is an extremely low-tech + + align:start position:0% +and that is an extremely low-tech + + + align:start position:0% +and that is an extremely low-tech +charmingly low-tech and yet i think very + + align:start position:0% +charmingly low-tech and yet i think very + + + align:start position:0% +charmingly low-tech and yet i think very +powerful discovery about face perception + + align:start position:0% +powerful discovery about face perception + + + align:start position:0% +powerful discovery about face perception +one of the most important original + + align:start position:0% +one of the most important original + + + align:start position:0% +one of the most important original +bits of evidence that face perception + + align:start position:0% +bits of evidence that face perception + + + align:start position:0% +bits of evidence that face perception +might be a different thing in the brain + + align:start position:0% +might be a different thing in the brain + + + align:start position:0% +might be a different thing in the brain +came from a phd thesis in this + + align:start position:0% +came from a phd thesis in this + + + align:start position:0% +came from a phd thesis in this +department by a guy named robert yin + + align:start position:0% +department by a guy named robert yin + + + align:start position:0% +department by a guy named robert yin +and he used the extremely high tech + + align:start position:0% +and he used the extremely high tech + + + align:start position:0% +and he used the extremely high tech +equipment of + + align:start position:0% +equipment of + + + align:start position:0% +equipment of +a stopwatch and paper + + align:start position:0% +a stopwatch and paper + + + align:start position:0% +a stopwatch and paper +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so what did he do he presented faces to + + align:start position:0% +so what did he do he presented faces to + + + align:start position:0% +so what did he do he presented faces to +people upright and he said study these + + align:start position:0% +people upright and he said study these + + + align:start position:0% +people upright and he said study these +20 faces and then he tested them later + + align:start position:0% +20 faces and then he tested them later + + + align:start position:0% +20 faces and then he tested them later +did you see this face did you see this + + align:start position:0% +did you see this face did you see this + + + align:start position:0% +did you see this face did you see this +face did you see this face + + align:start position:0% +face did you see this face + + + align:start position:0% +face did you see this face +and then he did the exact same + + align:start position:0% +and then he did the exact same + + + align:start position:0% +and then he did the exact same +experiment on a different set of phases + + align:start position:0% +experiment on a different set of phases + + + align:start position:0% +experiment on a different set of phases +but they were all upside down studied + + align:start position:0% +but they were all upside down studied + + + align:start position:0% +but they were all upside down studied +upside down and tested upside down + + align:start position:0% +upside down and tested upside down + + + align:start position:0% +upside down and tested upside down +okay and what did he find + + align:start position:0% +okay and what did he find + + + align:start position:0% +okay and what did he find +he found what's known as the face + + align:start position:0% +he found what's known as the face + + + align:start position:0% +he found what's known as the face +inversion effect + + align:start position:0% +inversion effect + + + align:start position:0% +inversion effect +namely people do much worse at this task + + align:start position:0% +namely people do much worse at this task + + + align:start position:0% +namely people do much worse at this task +when the faces are upside down here's + + align:start position:0% +when the faces are upside down here's + + + align:start position:0% +when the faces are upside down here's +errors for inverted upside down errors + + align:start position:0% +errors for inverted upside down errors + + + align:start position:0% +errors for inverted upside down errors +for upright at this task + + align:start position:0% +for upright at this task + + + align:start position:0% +for upright at this task +even though importantly they were + + align:start position:0% +even though importantly they were + + + align:start position:0% +even though importantly they were +studied and tested upside down or + + align:start position:0% +studied and tested upside down or + + + align:start position:0% +studied and tested upside down or +studied and tested inverted + + align:start position:0% +studied and tested inverted + + + align:start position:0% +studied and tested inverted +upright + + align:start position:0% +upright + + + align:start position:0% +upright +okay everybody got what this shows okay + + align:start position:0% +okay everybody got what this shows okay + + + align:start position:0% +okay everybody got what this shows okay +so that's cool um that this face + + align:start position:0% +so that's cool um that this face + + + align:start position:0% +so that's cool um that this face +inversion um so but the further cool + + align:start position:0% +inversion um so but the further cool + + + align:start position:0% +inversion um so but the further cool +thing is he showed that this face + + align:start position:0% +thing is he showed that this face + + + align:start position:0% +thing is he showed that this face +inversion effect is greater for faces + + align:start position:0% +inversion effect is greater for faces + + + align:start position:0% +inversion effect is greater for faces +than for other kinds of stimuli so he + + align:start position:0% +than for other kinds of stimuli so he + + + align:start position:0% +than for other kinds of stimuli so he +tested lots of other things including + + align:start position:0% +tested lots of other things including + + + align:start position:0% +tested lots of other things including +houses and stick figures + + align:start position:0% +houses and stick figures + + + align:start position:0% +houses and stick figures +and he showed that that cost when you + + align:start position:0% +and he showed that that cost when you + + + align:start position:0% +and he showed that that cost when you +turn the stimuli upside down is greater + + align:start position:0% +turn the stimuli upside down is greater + + + align:start position:0% +turn the stimuli upside down is greater +that difference is greater for faces + + align:start position:0% +that difference is greater for faces + + + align:start position:0% +that difference is greater for faces +than for other classes of stimuli + + align:start position:0% +than for other classes of stimuli + + + align:start position:0% +than for other classes of stimuli +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so what that suggests + + align:start position:0% +so what that suggests + + + align:start position:0% +so what that suggests +is that + + align:start position:0% +is that + + + align:start position:0% +is that +face recognition may just work + + align:start position:0% +face recognition may just work + + + align:start position:0% +face recognition may just work +differently in some deep way from + + align:start position:0% +differently in some deep way from + + + align:start position:0% +differently in some deep way from +recognition of other classes of stimuli + + align:start position:0% +recognition of other classes of stimuli + + + align:start position:0% +recognition of other classes of stimuli +and robert yin actually inferred in his + + align:start position:0% +and robert yin actually inferred in his + + + align:start position:0% +and robert yin actually inferred in his +phd thesis way way back before any + + align:start position:0% +phd thesis way way back before any + + + align:start position:0% +phd thesis way way back before any +imaging method that maybe there are + + align:start position:0% +imaging method that maybe there are + + + align:start position:0% +imaging method that maybe there are +special parts of the brain for face + + align:start position:0% +special parts of the brain for face + + + align:start position:0% +special parts of the brain for face +recognition and maybe face recognition + + align:start position:0% +recognition and maybe face recognition + + + align:start position:0% +recognition and maybe face recognition +is just a totally different thing that's + + align:start position:0% +is just a totally different thing that's + + + align:start position:0% +is just a totally different thing that's +why it is more affected by inversion + + align:start position:0% +why it is more affected by inversion + + + align:start position:0% +why it is more affected by inversion +than recognition of other kinds of + + align:start position:0% +than recognition of other kinds of + + + align:start position:0% +than recognition of other kinds of +things was there a question back there + + align:start position:0% +things was there a question back there + + + align:start position:0% +things was there a question back there +yeah i was going to ask is that just + + align:start position:0% +yeah i was going to ask is that just + + + align:start position:0% +yeah i was going to ask is that just +could that just be because spaces are + + align:start position:0% +could that just be because spaces are + + + align:start position:0% +could that just be because spaces are +much more complex than houses or stick + + align:start position:0% +much more complex than houses or stick + + + align:start position:0% +much more complex than houses or stick +figures in that + + align:start position:0% +figures in that + + + align:start position:0% +figures in that +good question hang on to + + align:start position:0% +good question hang on to + + + align:start position:0% +good question hang on to +good question that's that's a very good + + align:start position:0% +good question that's that's a very good + + + align:start position:0% +good question that's that's a very good +question and many people have tried to + + align:start position:0% +question and many people have tried to + + + align:start position:0% +question and many people have tried to +grapple with that um and actually about + + align:start position:0% +grapple with that um and actually about + + + align:start position:0% +grapple with that um and actually about +10 years ago the idea that this + + align:start position:0% +10 years ago the idea that this + + + align:start position:0% +10 years ago the idea that this +disproportionate effect for faces was + + align:start position:0% +disproportionate effect for faces was + + + align:start position:0% +disproportionate effect for faces was +like you know standard textbook + + align:start position:0% +like you know standard textbook + + + align:start position:0% +like you know standard textbook +completely accepted and now there's like + + align:start position:0% +completely accepted and now there's like + + + align:start position:0% +completely accepted and now there's like +another round of people doubting it with + + align:start position:0% +another round of people doubting it with + + + align:start position:0% +another round of people doubting it with +other kinds of stimuli so it's kind of + + align:start position:0% +other kinds of stimuli so it's kind of + + + align:start position:0% +other kinds of stimuli so it's kind of +ongoing it's a very robust difference + + align:start position:0% +ongoing it's a very robust difference + + + align:start position:0% +ongoing it's a very robust difference +but to say exactly what it is about face + + align:start position:0% +but to say exactly what it is about face + + + align:start position:0% +but to say exactly what it is about face +stimuli versus other kinds of things + + align:start position:0% +stimuli versus other kinds of things + + + align:start position:0% +stimuli versus other kinds of things +that is responsible for that difference + + align:start position:0% +that is responsible for that difference + + + align:start position:0% +that is responsible for that difference +you can imagine + + align:start position:0% +you can imagine + + + align:start position:0% +you can imagine +it's um it's subtle for the for the + + align:start position:0% +it's um it's subtle for the for the + + + align:start position:0% +it's um it's subtle for the for the +purposes of this this course i'm trying + + align:start position:0% +purposes of this this course i'm trying + + + align:start position:0% +purposes of this this course i'm trying +to like not quite lie to you guys but + + align:start position:0% +to like not quite lie to you guys but + + + align:start position:0% +to like not quite lie to you guys but +give you the most standard view without + + align:start position:0% +give you the most standard view without + + + align:start position:0% +give you the most standard view without +freighting you with every possible + + align:start position:0% +freighting you with every possible + + + align:start position:0% +freighting you with every possible +objection to every little thing because + + align:start position:0% +objection to every little thing because + + + align:start position:0% +objection to every little thing because +pretty much every finding there's + + align:start position:0% +pretty much every finding there's + + + align:start position:0% +pretty much every finding there's +somebody who has a beef with it you know + + align:start position:0% +somebody who has a beef with it you know + + + align:start position:0% +somebody who has a beef with it you know +and we'll tell you that's not really + + align:start position:0% +and we'll tell you that's not really + + + align:start position:0% +and we'll tell you that's not really +true because bloody blood okay so yes + + align:start position:0% +true because bloody blood okay so yes + + + align:start position:0% +true because bloody blood okay so yes +there are there's a little bit of uh + + align:start position:0% +there are there's a little bit of uh + + + align:start position:0% +there are there's a little bit of uh +debate going on about this right now but + + align:start position:0% +debate going on about this right now but + + + align:start position:0% +debate going on about this right now but +for the purposes of this course it's + + align:start position:0% +for the purposes of this course it's + + + align:start position:0% +for the purposes of this course it's +pretty damn rock solid at least as an + + align:start position:0% +pretty damn rock solid at least as an + + + align:start position:0% +pretty damn rock solid at least as an +empirical result okay + + align:start position:0% +empirical result okay + + + align:start position:0% +empirical result okay +all right um so there's in fact lots of + + align:start position:0% +all right um so there's in fact lots of + + + align:start position:0% +all right um so there's in fact lots of +versions of the um of the face inversion + + align:start position:0% +versions of the um of the face inversion + + + align:start position:0% +versions of the um of the face inversion +effect one you may have seen before but + + align:start position:0% +effect one you may have seen before but + + + align:start position:0% +effect one you may have seen before but +which is very amusing if you look at + + align:start position:0% +which is very amusing if you look at + + + align:start position:0% +which is very amusing if you look at +faces like this that are upside down + + align:start position:0% +faces like this that are upside down + + + align:start position:0% +faces like this that are upside down +they look + + align:start position:0% +they look + + + align:start position:0% +they look +you know sort of normal + + align:start position:0% +you know sort of normal + + + align:start position:0% +you know sort of normal +uh but then if you rotate them you + + align:start position:0% +uh but then if you rotate them you + + + align:start position:0% +uh but then if you rotate them you +realize there's something deeply weird + + align:start position:0% +realize there's something deeply weird + + + align:start position:0% +realize there's something deeply weird +going on okay so the point is you're + + align:start position:0% +going on okay so the point is you're + + + align:start position:0% +going on okay so the point is you're +much more sensitive to those grotesquely + + align:start position:0% +much more sensitive to those grotesquely + + + align:start position:0% +much more sensitive to those grotesquely +distorted faces when you see them right + + align:start position:0% +distorted faces when you see them right + + + align:start position:0% +distorted faces when you see them right +side up than when you see them upside + + align:start position:0% +side up than when you see them upside + + + align:start position:0% +side up than when you see them upside +down so that's another version of the + + align:start position:0% +down so that's another version of the + + + align:start position:0% +down so that's another version of the +face inversion effect and there are many + + align:start position:0% +face inversion effect and there are many + + + align:start position:0% +face inversion effect and there are many +many incarnations of this effect you'll + + align:start position:0% +many incarnations of this effect you'll + + + align:start position:0% +many incarnations of this effect you'll +see another one later in the + + align:start position:0% +see another one later in the + + + align:start position:0% +see another one later in the +in the lecture so um so where did we get + + align:start position:0% +in the lecture so um so where did we get + + + align:start position:0% +in the lecture so um so where did we get +last time with these questions we got + + align:start position:0% +last time with these questions we got + + + align:start position:0% +last time with these questions we got +that one of the major if not the major + + align:start position:0% +that one of the major if not the major + + + align:start position:0% +that one of the major if not the major +central challenge in face recognition at + + align:start position:0% +central challenge in face recognition at + + + align:start position:0% +central challenge in face recognition at +a computational level + + align:start position:0% +a computational level + + + align:start position:0% +a computational level +is the fact that we deal with a huge + + align:start position:0% +is the fact that we deal with a huge + + + align:start position:0% +is the fact that we deal with a huge +image variation each time we see a face + + align:start position:0% +image variation each time we see a face + + + align:start position:0% +image variation each time we see a face +and yet somehow we're able to grapple + + align:start position:0% +and yet somehow we're able to grapple + + + align:start position:0% +and yet somehow we're able to grapple +with it so to understand how face + + align:start position:0% +with it so to understand how face + + + align:start position:0% +with it so to understand how face +recognition works would be to understand + + align:start position:0% +recognition works would be to understand + + + align:start position:0% +recognition works would be to understand +what is the code ultimately nobody knows + + align:start position:0% +what is the code ultimately nobody knows + + + align:start position:0% +what is the code ultimately nobody knows +right now but what is the code running + + align:start position:0% +right now but what is the code running + + + align:start position:0% +right now but what is the code running +in our heads that enables us to do that + + align:start position:0% +in our heads that enables us to do that + + + align:start position:0% +in our heads that enables us to do that +what is our mental representation of the + + align:start position:0% +what is our mental representation of the + + + align:start position:0% +what is our mental representation of the +face that enables us to deal with this + + align:start position:0% +face that enables us to deal with this + + + align:start position:0% +face that enables us to deal with this +problem + + align:start position:0% +problem + + + align:start position:0% +problem +by looking at behavioral data + + align:start position:0% +by looking at behavioral data + + + align:start position:0% +by looking at behavioral data +we got some evidence from the dutch + + align:start position:0% +we got some evidence from the dutch + + + align:start position:0% +we got some evidence from the dutch +politician study that + + align:start position:0% +politician study that + + + align:start position:0% +politician study that +whatever that representation is that we + + align:start position:0% +whatever that representation is that we + + + align:start position:0% +whatever that representation is that we +extract from faces it's not independent + + align:start position:0% +extract from faces it's not independent + + + align:start position:0% +extract from faces it's not independent +of the particular image it's not that we + + align:start position:0% +of the particular image it's not that we + + + align:start position:0% +of the particular image it's not that we +have some you know platonic ideal of the + + align:start position:0% +have some you know platonic ideal of the + + + align:start position:0% +have some you know platonic ideal of the +face that we can extract from any face + + align:start position:0% +face that we can extract from any face + + + align:start position:0% +face that we can extract from any face +that lands on our retina a planet + + align:start position:0% +that lands on our retina a planet + + + align:start position:0% +that lands on our retina a planet +platonic ideal of that person's face + + align:start position:0% +platonic ideal of that person's face + + + align:start position:0% +platonic ideal of that person's face +right so whatever we're doing it's not + + align:start position:0% +right so whatever we're doing it's not + + + align:start position:0% +right so whatever we're doing it's not +completely invariant um because we can't + + align:start position:0% +completely invariant um because we can't + + + align:start position:0% +completely invariant um because we can't +do that so well with + + align:start position:0% +do that so well with + + + align:start position:0% +do that so well with +unfamiliar faces okay + + align:start position:0% +unfamiliar faces okay + + + align:start position:0% +unfamiliar faces okay +also as i just showed you related but + + align:start position:0% +also as i just showed you related but + + + align:start position:0% +also as i just showed you related but +not exactly the same point + + align:start position:0% +not exactly the same point + + + align:start position:0% +not exactly the same point +our mental representations of faces are + + align:start position:0% +our mental representations of faces are + + + align:start position:0% +our mental representations of faces are +very sensitive to the orientation of the + + align:start position:0% +very sensitive to the orientation of the + + + align:start position:0% +very sensitive to the orientation of the +face + + align:start position:0% +face + + + align:start position:0% +face +more than our mental representations of + + align:start position:0% +more than our mental representations of + + + align:start position:0% +more than our mental representations of +other classes of stimuli + + align:start position:0% +other classes of stimuli + + + align:start position:0% +other classes of stimuli +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so those are just very simple uh + + align:start position:0% +so those are just very simple uh + + + align:start position:0% +so those are just very simple uh +insights about the whatever whatever our + + align:start position:0% +insights about the whatever whatever our + + + align:start position:0% +insights about the whatever whatever our +representations of faces are in our + + align:start position:0% +representations of faces are in our + + + align:start position:0% +representations of faces are in our +heads just from simple behavioral data + + align:start position:0% +heads just from simple behavioral data + + + align:start position:0% +heads just from simple behavioral data +okay + + align:start position:0% +okay + + + align:start position:0% +okay +okay + + align:start position:0% +okay + + + align:start position:0% +okay +um so let me just review some of the + + align:start position:0% +um so let me just review some of the + + + align:start position:0% +um so let me just review some of the +strengths and weaknesses of + + align:start position:0% +strengths and weaknesses of + + + align:start position:0% +strengths and weaknesses of +simple behavioral methods strengths are + + align:start position:0% +simple behavioral methods strengths are + + + align:start position:0% +simple behavioral methods strengths are +they're good for characterizing the + + align:start position:0% +they're good for characterizing the + + + align:start position:0% +they're good for characterizing the +internal representation right not with + + align:start position:0% +internal representation right not with + + + align:start position:0% +internal representation right not with +huge computational precision they're + + align:start position:0% +huge computational precision they're + + + align:start position:0% +huge computational precision they're +more like with gisty kind of ideas like + + align:start position:0% +more like with gisty kind of ideas like + + + align:start position:0% +more like with gisty kind of ideas like +okay they're not very invariant they + + align:start position:0% +okay they're not very invariant they + + + align:start position:0% +okay they're not very invariant they +depend on the orientation right that's + + align:start position:0% +depend on the orientation right that's + + + align:start position:0% +depend on the orientation right that's +not very precise but it's a whole lot + + align:start position:0% +not very precise but it's a whole lot + + + align:start position:0% +not very precise but it's a whole lot +better than nothing okay + + align:start position:0% +better than nothing okay + + + align:start position:0% +better than nothing okay +that's what i mean by at least + + align:start position:0% +that's what i mean by at least + + + align:start position:0% +that's what i mean by at least +qualitatively + + align:start position:0% +qualitatively + + + align:start position:0% +qualitatively +they're good for dissociating mental + + align:start position:0% +they're good for dissociating mental + + + align:start position:0% +they're good for dissociating mental +phenomena so you've already seen that in + + align:start position:0% +phenomena so you've already seen that in + + + align:start position:0% +phenomena so you've already seen that in +the inversion effect it happens more for + + align:start position:0% +the inversion effect it happens more for + + + align:start position:0% +the inversion effect it happens more for +faces than other things so that already + + align:start position:0% +faces than other things so that already + + + align:start position:0% +faces than other things so that already +starts to tell us okay maybe however + + align:start position:0% +starts to tell us okay maybe however + + + align:start position:0% +starts to tell us okay maybe however +whatever the code in our head is that we + + align:start position:0% +whatever the code in our head is that we + + + align:start position:0% +whatever the code in our head is that we +use for face recognition maybe it's + + align:start position:0% +use for face recognition maybe it's + + + align:start position:0% +use for face recognition maybe it's +pretty different than the code that we + + align:start position:0% +pretty different than the code that we + + + align:start position:0% +pretty different than the code that we +use in our head to recognize objects + + align:start position:0% +use in our head to recognize objects + + + align:start position:0% +use in our head to recognize objects +okay + + align:start position:0% +okay + + + align:start position:0% +okay +um + + align:start position:0% +um + + + align:start position:0% +um +okay it's also cheap it's really cheap + + align:start position:0% +okay it's also cheap it's really cheap + + + align:start position:0% +okay it's also cheap it's really cheap +much cheaper than all the other methods + + align:start position:0% +much cheaper than all the other methods + + + align:start position:0% +much cheaper than all the other methods +okay weaknesses + + align:start position:0% +okay weaknesses + + + align:start position:0% +okay weaknesses +it doesn't behavioral methods alone + + align:start position:0% +it doesn't behavioral methods alone + + + align:start position:0% +it doesn't behavioral methods alone +don't have any relationship to the brain + + align:start position:0% +don't have any relationship to the brain + + + align:start position:0% +don't have any relationship to the brain +at least without doing extra work okay + + align:start position:0% +at least without doing extra work okay + + + align:start position:0% +at least without doing extra work okay +and it it + + align:start position:0% +and it it + + + align:start position:0% +and it it +it's not that they are useless until you + + align:start position:0% +it's not that they are useless until you + + + align:start position:0% +it's not that they are useless until you +link them to the brain it's just that + + align:start position:0% +link them to the brain it's just that + + + align:start position:0% +link them to the brain it's just that +the brain is a whole source of other + + align:start position:0% +the brain is a whole source of other + + + align:start position:0% +the brain is a whole source of other +data and it's nice to link them because + + align:start position:0% +data and it's nice to link them because + + + align:start position:0% +data and it's nice to link them because +then you can connect with all those + + align:start position:0% +then you can connect with all those + + + align:start position:0% +then you can connect with all those +other data + + align:start position:0% +other data + + + align:start position:0% +other data +also behavioral data are pretty sparse + + align:start position:0% +also behavioral data are pretty sparse + + + align:start position:0% +also behavioral data are pretty sparse +like for the most part you have accuracy + + align:start position:0% +like for the most part you have accuracy + + + align:start position:0% +like for the most part you have accuracy +and reaction time and that's it + + align:start position:0% +and reaction time and that's it + + + align:start position:0% +and reaction time and that's it +and that's just not a whole lot of data + + align:start position:0% +and that's just not a whole lot of data + + + align:start position:0% +and that's just not a whole lot of data +to work with you have to actually be + + align:start position:0% +to work with you have to actually be + + + align:start position:0% +to work with you have to actually be +much smarter to be a behavioral + + align:start position:0% +much smarter to be a behavioral + + + align:start position:0% +much smarter to be a behavioral +cognitive psychologist and you have to + + align:start position:0% +cognitive psychologist and you have to + + + align:start position:0% +cognitive psychologist and you have to +be to be to to be a cognitive + + align:start position:0% +be to be to to be a cognitive + + + align:start position:0% +be to be to to be a cognitive +neuroscientist where you have much + + align:start position:0% +neuroscientist where you have much + + + align:start position:0% +neuroscientist where you have much +richer data to reason from like + + align:start position:0% +richer data to reason from like + + + align:start position:0% +richer data to reason from like +cognitive psychologists really have very + + align:start position:0% +cognitive psychologists really have very + + + align:start position:0% +cognitive psychologists really have very +very clever designs because they're + + align:start position:0% +very clever designs because they're + + + align:start position:0% +very clever designs because they're +taking this extremely limited data and + + align:start position:0% +taking this extremely limited data and + + + align:start position:0% +taking this extremely limited data and +trying to pull out interesting insights + + align:start position:0% +trying to pull out interesting insights + + + align:start position:0% +trying to pull out interesting insights +about mental function + + align:start position:0% +about mental function + + + align:start position:0% +about mental function +another way of looking at that is + + align:start position:0% +another way of looking at that is + + + align:start position:0% +another way of looking at that is +here's you know an eyeball and a bunch + + align:start position:0% +here's you know an eyeball and a bunch + + + align:start position:0% +here's you know an eyeball and a bunch +of processing going over stages and a + + align:start position:0% +of processing going over stages and a + + + align:start position:0% +of processing going over stages and a +response right + + align:start position:0% +response right + + + align:start position:0% +response right +with behavioral data all you have is + + align:start position:0% +with behavioral data all you have is + + + align:start position:0% +with behavioral data all you have is +that response + + align:start position:0% +that response + + + align:start position:0% +that response +but presumably for most of the mental + + align:start position:0% +but presumably for most of the mental + + + align:start position:0% +but presumably for most of the mental +processes that go on in our heads there + + align:start position:0% +processes that go on in our heads there + + + align:start position:0% +processes that go on in our heads there +are many different stages of processing + + align:start position:0% +are many different stages of processing + + + align:start position:0% +are many different stages of processing +where different things are going on + + align:start position:0% +where different things are going on + + + align:start position:0% +where different things are going on +computations tend to have multiple + + align:start position:0% +computations tend to have multiple + + + align:start position:0% +computations tend to have multiple +stages and unfold over time and all we + + align:start position:0% +stages and unfold over time and all we + + + align:start position:0% +stages and unfold over time and all we +have is output + + align:start position:0% +have is output + + + align:start position:0% +have is output +so really what we want to be able to do + + align:start position:0% +so really what we want to be able to do + + + align:start position:0% +so really what we want to be able to do +is characterize the whole sequence of + + align:start position:0% +is characterize the whole sequence of + + + align:start position:0% +is characterize the whole sequence of +processes + + align:start position:0% +processes + + + align:start position:0% +processes +and it's not that you can't get insights + + align:start position:0% +and it's not that you can't get insights + + + align:start position:0% +and it's not that you can't get insights +about some of those intermediates from + + align:start position:0% +about some of those intermediates from + + + align:start position:0% +about some of those intermediates from +behavioral data it's just much more + + align:start position:0% +behavioral data it's just much more + + + align:start position:0% +behavioral data it's just much more +challenging + + align:start position:0% +challenging + + + align:start position:0% +challenging +so if we had a way to look at those + + align:start position:0% +so if we had a way to look at those + + + align:start position:0% +so if we had a way to look at those +things independently wouldn't that be + + align:start position:0% +things independently wouldn't that be + + + align:start position:0% +things independently wouldn't that be +awesome + + align:start position:0% + + + + align:start position:0% + +okay so there's lots of ways to do that + + align:start position:0% +okay so there's lots of ways to do that + + + align:start position:0% +okay so there's lots of ways to do that +and a particularly good one is + + align:start position:0% +and a particularly good one is + + + align:start position:0% +and a particularly good one is +functional mri so as i mentioned before + + align:start position:0% +functional mri so as i mentioned before + + + align:start position:0% +functional mri so as i mentioned before +i mentioned this very of + + align:start position:0% +i mentioned this very of + + + align:start position:0% +i mentioned this very of +brief very briefly this very early + + align:start position:0% +brief very briefly this very early + + + align:start position:0% +brief very briefly this very early +experiment that i did way back + + align:start position:0% +experiment that i did way back + + + align:start position:0% +experiment that i did way back +asking whether there is a region of the + + align:start position:0% +asking whether there is a region of the + + + align:start position:0% +asking whether there is a region of the +brain that's selectively involved in + + align:start position:0% +brain that's selectively involved in + + + align:start position:0% +brain that's selectively involved in +processing faces + + align:start position:0% +processing faces + + + align:start position:0% +processing faces +and i'm going to put a slightly + + align:start position:0% +and i'm going to put a slightly + + + align:start position:0% +and i'm going to put a slightly +different spin on it from what i put + + align:start position:0% +different spin on it from what i put + + + align:start position:0% +different spin on it from what i put +before it's the same experiment same + + align:start position:0% +before it's the same experiment same + + + align:start position:0% +before it's the same experiment same +data but i want to emphasize more the + + align:start position:0% +data but i want to emphasize more the + + + align:start position:0% +data but i want to emphasize more the +logic of the experimental design because + + align:start position:0% +logic of the experimental design because + + + align:start position:0% +logic of the experimental design because +you guys will be designing an experiment + + align:start position:0% +you guys will be designing an experiment + + + align:start position:0% +you guys will be designing an experiment +on a different topic um + + align:start position:0% +on a different topic um + + + align:start position:0% +on a different topic um +by + + align:start position:0% +by + + + align:start position:0% +by +a due monday night okay that we're gonna + + align:start position:0% +a due monday night okay that we're gonna + + + align:start position:0% +a due monday night okay that we're gonna +discuss in uh sunday night that we're + + align:start position:0% +discuss in uh sunday night that we're + + + align:start position:0% +discuss in uh sunday night that we're +gonna discuss in class on monday okay + + align:start position:0% +gonna discuss in class on monday okay + + + align:start position:0% +gonna discuss in class on monday okay +so we start with a hypothesis that + + align:start position:0% +so we start with a hypothesis that + + + align:start position:0% +so we start with a hypothesis that +there's a special um there's a a region + + align:start position:0% +there's a special um there's a a region + + + align:start position:0% +there's a special um there's a a region +of the brain that's selectively + + align:start position:0% +of the brain that's selectively + + + align:start position:0% +of the brain that's selectively +responsive to faces that's the + + align:start position:0% +responsive to faces that's the + + + align:start position:0% +responsive to faces that's the +hypothesis the way we test it is to pop + + align:start position:0% +hypothesis the way we test it is to pop + + + align:start position:0% +hypothesis the way we test it is to pop +people in a scanner and show them faces + + align:start position:0% +people in a scanner and show them faces + + + align:start position:0% +people in a scanner and show them faces +and objects the data that i showed you + + align:start position:0% +and objects the data that i showed you + + + align:start position:0% +and objects the data that i showed you +before is that this little patch of the + + align:start position:0% +before is that this little patch of the + + + align:start position:0% +before is that this little patch of the +brain remember this is a horizontal + + align:start position:0% +brain remember this is a horizontal + + + align:start position:0% +brain remember this is a horizontal +slice back of the head left and right + + align:start position:0% +slice back of the head left and right + + + align:start position:0% +slice back of the head left and right +are flipped so that little region in me + + align:start position:0% +are flipped so that little region in me + + + align:start position:0% +are flipped so that little region in me +is right about in there everybody + + align:start position:0% +is right about in there everybody + + + align:start position:0% +is right about in there everybody +oriented okay + + align:start position:0% +oriented okay + + + align:start position:0% +oriented okay +that region responds much more to faces + + align:start position:0% +that region responds much more to faces + + + align:start position:0% +that region responds much more to faces +than objects is that clear to everybody + + align:start position:0% +than objects is that clear to everybody + + + align:start position:0% +than objects is that clear to everybody +what that is okay + + align:start position:0% +what that is okay + + + align:start position:0% +what that is okay +so + + align:start position:0% +so + + + align:start position:0% +so +um yes there's and you see that in most + + align:start position:0% +um yes there's and you see that in most + + + align:start position:0% +um yes there's and you see that in most +subjects so yes there's a bit that + + align:start position:0% +subjects so yes there's a bit that + + + align:start position:0% +subjects so yes there's a bit that +responds more to faces and objects + + align:start position:0% +responds more to faces and objects + + + align:start position:0% +responds more to faces and objects +um but now let's consider the hypothesis + + align:start position:0% +um but now let's consider the hypothesis + + + align:start position:0% +um but now let's consider the hypothesis +that that region is really selective to + + align:start position:0% +that that region is really selective to + + + align:start position:0% +that that region is really selective to +faces per se + + align:start position:0% +faces per se + + + align:start position:0% +faces per se +and the way you evaluate whether these + + align:start position:0% +and the way you evaluate whether these + + + align:start position:0% +and the way you evaluate whether these +data so how strongly these data support + + align:start position:0% +data so how strongly these data support + + + align:start position:0% +data so how strongly these data support +that hypothesis they're certainly + + align:start position:0% +that hypothesis they're certainly + + + align:start position:0% +that hypothesis they're certainly +consistent with it but do they nail that + + align:start position:0% +consistent with it but do they nail that + + + align:start position:0% +consistent with it but do they nail that +hypothesis fully + + align:start position:0% +hypothesis fully + + + align:start position:0% +hypothesis fully +is to consider are there any other + + align:start position:0% +is to consider are there any other + + + align:start position:0% +is to consider are there any other +alternative accounts we can think of + + align:start position:0% +alternative accounts we can think of + + + align:start position:0% +alternative accounts we can think of +that are consistent with these data and + + align:start position:0% +that are consistent with these data and + + + align:start position:0% +that are consistent with these data and +different from that hypothesis + + align:start position:0% +different from that hypothesis + + + align:start position:0% +different from that hypothesis +is that clear it's really important + + align:start position:0% +is that clear it's really important + + + align:start position:0% +is that clear it's really important +that's just the whole + + align:start position:0% +that's just the whole + + + align:start position:0% +that's just the whole +kernel of scientific thinking + + align:start position:0% +kernel of scientific thinking + + + align:start position:0% +kernel of scientific thinking +and evaluating evidence is asking + + align:start position:0% +and evaluating evidence is asking + + + align:start position:0% +and evaluating evidence is asking +yourself that question is there any + + align:start position:0% +yourself that question is there any + + + align:start position:0% +yourself that question is there any +other way we could get those data where + + align:start position:0% +other way we could get those data where + + + align:start position:0% +other way we could get those data where +that hypothesis was wasn't true and if + + align:start position:0% +that hypothesis was wasn't true and if + + + align:start position:0% +that hypothesis was wasn't true and if +so you got to grapple with it + + align:start position:0% +so you got to grapple with it + + + align:start position:0% +so you got to grapple with it +so what you do next is you think about + + align:start position:0% +so what you do next is you think about + + + align:start position:0% +so what you do next is you think about +our alternative hypotheses + + align:start position:0% +our alternative hypotheses + + + align:start position:0% +our alternative hypotheses +to the one you started with + + align:start position:0% +to the one you started with + + + align:start position:0% +to the one you started with +that is different accounts of the same + + align:start position:0% +that is different accounts of the same + + + align:start position:0% +that is different accounts of the same +data + + align:start position:0% +data + + + align:start position:0% +data +and so in in our case you guys suggested + + align:start position:0% +and so in in our case you guys suggested + + + align:start position:0% +and so in in our case you guys suggested +a whole bunch i suggested a bunch + + align:start position:0% +a whole bunch i suggested a bunch + + + align:start position:0% +a whole bunch i suggested a bunch +and though then the next thing i showed + + align:start position:0% +and though then the next thing i showed + + + align:start position:0% +and though then the next thing i showed +you is that we can test those + + align:start position:0% +you is that we can test those + + + align:start position:0% +you is that we can test those +alternative hypotheses at least these + + align:start position:0% +alternative hypotheses at least these + + + align:start position:0% +alternative hypotheses at least these +ones here + + align:start position:0% +ones here + + + align:start position:0% +ones here +by um first + + align:start position:0% +by um first + + + align:start position:0% +by um first +what we did was i didn't really + + align:start position:0% +what we did was i didn't really + + + align:start position:0% +what we did was i didn't really +emphasize this before but we re-ran that + + align:start position:0% +emphasize this before but we re-ran that + + + align:start position:0% +emphasize this before but we re-ran that +experiment in a new bunch of subjects + + align:start position:0% +experiment in a new bunch of subjects + + + align:start position:0% +experiment in a new bunch of subjects +each subject individually we found in + + align:start position:0% +each subject individually we found in + + + align:start position:0% +each subject individually we found in +each subject the little bit that does + + align:start position:0% +each subject the little bit that does + + + align:start position:0% +each subject the little bit that does +this + + align:start position:0% +this + + + align:start position:0% +this +we write down exactly where that is in + + align:start position:0% +we write down exactly where that is in + + + align:start position:0% +we write down exactly where that is in +the br in that person's brain okay now + + align:start position:0% +the br in that person's brain okay now + + + align:start position:0% +the br in that person's brain okay now +that we've found that region that's + + align:start position:0% +that we've found that region that's + + + align:start position:0% +that we've found that region that's +called a localizer run because we're + + align:start position:0% +called a localizer run because we're + + + align:start position:0% +called a localizer run because we're +finding that region in each subject + + align:start position:0% +finding that region in each subject + + + align:start position:0% +finding that region in each subject +individually + + align:start position:0% +individually + + + align:start position:0% +individually +now we can ask it new questions + + align:start position:0% +now we can ask it new questions + + + align:start position:0% +now we can ask it new questions +okay and so the new questions we asked + + align:start position:0% +okay and so the new questions we asked + + + align:start position:0% +okay and so the new questions we asked +it last time + + align:start position:0% +it last time + + + align:start position:0% +it last time +was to present faces and hands and we + + align:start position:0% +was to present faces and hands and we + + + align:start position:0% +was to present faces and hands and we +found oh that region right there + + align:start position:0% +found oh that region right there + + + align:start position:0% +found oh that region right there +responds like this + + align:start position:0% +responds like this + + + align:start position:0% +responds like this +okay so the key ideas here is that we + + align:start position:0% +okay so the key ideas here is that we + + + align:start position:0% +okay so the key ideas here is that we +can we can identify that region in each + + align:start position:0% +can we can identify that region in each + + + align:start position:0% +can we can identify that region in each +subject individually with a functional + + align:start position:0% +subject individually with a functional + + + align:start position:0% +subject individually with a functional +scan the reason that's important which + + align:start position:0% +scan the reason that's important which + + + align:start position:0% +scan the reason that's important which +i'll carry on about in more detail later + + align:start position:0% +i'll carry on about in more detail later + + + align:start position:0% +i'll carry on about in more detail later +is that the exact location of that + + align:start position:0% +is that the exact location of that + + + align:start position:0% +is that the exact location of that +region varies from one subject to the + + align:start position:0% +region varies from one subject to the + + + align:start position:0% +region varies from one subject to the +next + + align:start position:0% +next + + + align:start position:0% +next +so if we just grab + + align:start position:0% +so if we just grab + + + align:start position:0% +so if we just grab +you know the whole fusiform gyrus or the + + align:start position:0% +you know the whole fusiform gyrus or the + + + align:start position:0% +you know the whole fusiform gyrus or the +whole lateral side of the fusiform gyrus + + align:start position:0% +whole lateral side of the fusiform gyrus + + + align:start position:0% +whole lateral side of the fusiform gyrus +and each subject we'll get lots of stuff + + align:start position:0% +and each subject we'll get lots of stuff + + + align:start position:0% +and each subject we'll get lots of stuff +that is that region and lots of cortical + + align:start position:0% +that is that region and lots of cortical + + + align:start position:0% +that is that region and lots of cortical +neighbors it's something else okay + + align:start position:0% +neighbors it's something else okay + + + align:start position:0% +neighbors it's something else okay +and if we grab you know if we took the + + align:start position:0% +and if we grab you know if we took the + + + align:start position:0% +and if we grab you know if we took the +exact location of that region to my + + align:start position:0% +exact location of that region to my + + + align:start position:0% +exact location of that region to my +brain and registered it to any of your + + align:start position:0% +brain and registered it to any of your + + + align:start position:0% +brain and registered it to any of your +brains and said okay let's take the part + + align:start position:0% +brains and said okay let's take the part + + + align:start position:0% +brains and said okay let's take the part +of your brain that registers spatially + + align:start position:0% +of your brain that registers spatially + + + align:start position:0% +of your brain that registers spatially +as well as we can with mine + + align:start position:0% +as well as we can with mine + + + align:start position:0% +as well as we can with mine +we're not going to exactly get the right + + align:start position:0% +we're not going to exactly get the right + + + align:start position:0% +we're not going to exactly get the right +bit + + align:start position:0% +bit + + + align:start position:0% +bit +so to study that thing we got to first + + align:start position:0% +so to study that thing we got to first + + + align:start position:0% +so to study that thing we got to first +find it functionally and then we can ask + + align:start position:0% +find it functionally and then we can ask + + + align:start position:0% +find it functionally and then we can ask +it new questions does that make sense + + align:start position:0% +it new questions does that make sense + + + align:start position:0% +it new questions does that make sense +okay if anybody's unclear about that i + + align:start position:0% +okay if anybody's unclear about that i + + + align:start position:0% +okay if anybody's unclear about that i +have actually online talks that go + + align:start position:0% +have actually online talks that go + + + align:start position:0% +have actually online talks that go +through the whole logic of this in + + align:start position:0% +through the whole logic of this in + + + align:start position:0% +through the whole logic of this in +painful detail and i'm happy to answer + + align:start position:0% +painful detail and i'm happy to answer + + + align:start position:0% +painful detail and i'm happy to answer +other questions about it later + + align:start position:0% +other questions about it later + + + align:start position:0% +other questions about it later +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so um i put the word conditions in red + + align:start position:0% +so um i put the word conditions in red + + + align:start position:0% +so um i put the word conditions in red +because somebody asked one of the tas + + align:start position:0% +because somebody asked one of the tas + + + align:start position:0% +because somebody asked one of the tas +what a condition was + + align:start position:0% +what a condition was + + + align:start position:0% +what a condition was +and that's not stupid i should have made + + align:start position:0% +and that's not stupid i should have made + + + align:start position:0% +and that's not stupid i should have made +that clear + + align:start position:0% +that clear + + + align:start position:0% +that clear +this is just experimental design + + align:start position:0% +this is just experimental design + + + align:start position:0% +this is just experimental design +gobbledygook that means + + align:start position:0% +gobbledygook that means + + + align:start position:0% +gobbledygook that means +any any + + align:start position:0% + + + + align:start position:0% + +okay what is the definition of condition + + align:start position:0% +okay what is the definition of condition + + + align:start position:0% +okay what is the definition of condition +in an experimental design you have + + align:start position:0% +in an experimental design you have + + + align:start position:0% +in an experimental design you have +things that you are manipulating and + + align:start position:0% +things that you are manipulating and + + + align:start position:0% +things that you are manipulating and +measuring + + align:start position:0% +measuring + + + align:start position:0% +measuring +okay so in this case we're manipulating + + align:start position:0% +okay so in this case we're manipulating + + + align:start position:0% +okay so in this case we're manipulating +the stimulus + + align:start position:0% +the stimulus + + + align:start position:0% +the stimulus +and we're measuring the magnitude of + + align:start position:0% +and we're measuring the magnitude of + + + align:start position:0% +and we're measuring the magnitude of +response in the fusiform face area okay + + align:start position:0% +response in the fusiform face area okay + + + align:start position:0% +response in the fusiform face area okay +or in the brain + + align:start position:0% +or in the brain + + + align:start position:0% +or in the brain +so what we're manipulating in this case + + align:start position:0% +so what we're manipulating in this case + + + align:start position:0% +so what we're manipulating in this case +is this the stimulus condition so that + + align:start position:0% +is this the stimulus condition so that + + + align:start position:0% +is this the stimulus condition so that +will be one condition that's another + + align:start position:0% +will be one condition that's another + + + align:start position:0% +will be one condition that's another +condition that's another condition does + + align:start position:0% +condition that's another condition does + + + align:start position:0% +condition that's another condition does +that make sense + + align:start position:0% +that make sense + + + align:start position:0% +that make sense +okay so for your experimental design + + align:start position:0% +okay so for your experimental design + + + align:start position:0% +okay so for your experimental design +assignment for uh monday night + + align:start position:0% +assignment for uh monday night + + + align:start position:0% +assignment for uh monday night +you'll be designing one or more + + align:start position:0% +you'll be designing one or more + + + align:start position:0% +you'll be designing one or more +experiments + + align:start position:0% +experiments + + + align:start position:0% +experiments +uh and you will be describing exactly + + align:start position:0% +uh and you will be describing exactly + + + align:start position:0% +uh and you will be describing exactly +what conditions you are going to test + + align:start position:0% +what conditions you are going to test + + + align:start position:0% +what conditions you are going to test +everybody clear on that + + align:start position:0% +everybody clear on that + + + align:start position:0% +everybody clear on that +okay all right um so these data enable + + align:start position:0% +okay all right um so these data enable + + + align:start position:0% +okay all right um so these data enable +us to rule out those hypotheses + + align:start position:0% +us to rule out those hypotheses + + + align:start position:0% +us to rule out those hypotheses +and now you could ask okay + + align:start position:0% +and now you could ask okay + + + align:start position:0% +and now you could ask okay +once you get more data like this have + + align:start position:0% +once you get more data like this have + + + align:start position:0% +once you get more data like this have +you completely nailed that hypothesis is + + align:start position:0% +you completely nailed that hypothesis is + + + align:start position:0% +you completely nailed that hypothesis is +there just no way that hypothesis could + + align:start position:0% +there just no way that hypothesis could + + + align:start position:0% +there just no way that hypothesis could +be wrong now given these data and those + + align:start position:0% +be wrong now given these data and those + + + align:start position:0% +be wrong now given these data and those +data and i'll let you percolate on that + + align:start position:0% +data and i'll let you percolate on that + + + align:start position:0% +data and i'll let you percolate on that +there are ways it could be wrong + + align:start position:0% +there are ways it could be wrong + + + align:start position:0% +there are ways it could be wrong +but they're you know you have to work + + align:start position:0% +but they're you know you have to work + + + align:start position:0% +but they're you know you have to work +harder to come up with them okay + + align:start position:0% + + + + align:start position:0% + +okay so + + align:start position:0% +okay so + + + align:start position:0% +okay so +um skipping ahead just to give you the + + align:start position:0% +um skipping ahead just to give you the + + + align:start position:0% +um skipping ahead just to give you the +gist this this field has been going on + + align:start position:0% +gist this this field has been going on + + + align:start position:0% +gist this this field has been going on +for a long time uh and there are now + + align:start position:0% +for a long time uh and there are now + + + align:start position:0% +for a long time uh and there are now +many many studies hundreds maybe even i + + align:start position:0% +many many studies hundreds maybe even i + + + align:start position:0% +many many studies hundreds maybe even i +don't know god maybe even thousands i + + align:start position:0% +don't know god maybe even thousands i + + + align:start position:0% +don't know god maybe even thousands i +don't know + + align:start position:0% +don't know + + + align:start position:0% +don't know +uh studies of this region um in which + + align:start position:0% +uh studies of this region um in which + + + align:start position:0% +uh studies of this region um in which +and so sort of a summary statement from + + align:start position:0% +and so sort of a summary statement from + + + align:start position:0% +and so sort of a summary statement from +a long time ago in my lab we've tested + + align:start position:0% +a long time ago in my lab we've tested + + + align:start position:0% +a long time ago in my lab we've tested +the response of this region to lots of + + align:start position:0% +the response of this region to lots of + + + align:start position:0% +the response of this region to lots of +different kinds of stimuli with that + + align:start position:0% +different kinds of stimuli with that + + + align:start position:0% +different kinds of stimuli with that +same method localize it in each subject + + align:start position:0% +same method localize it in each subject + + + align:start position:0% +same method localize it in each subject +measure its response when people look at + + align:start position:0% +measure its response when people look at + + + align:start position:0% +measure its response when people look at +that kind of stimulus okay + + align:start position:0% +that kind of stimulus okay + + + align:start position:0% +that kind of stimulus okay +and so what we know now was that this + + align:start position:0% +and so what we know now was that this + + + align:start position:0% +and so what we know now was that this +region is found in roughly the same + + align:start position:0% +region is found in roughly the same + + + align:start position:0% +region is found in roughly the same +location + + align:start position:0% +location + + + align:start position:0% +location +in pretty much every normal subject it + + align:start position:0% +in pretty much every normal subject it + + + align:start position:0% +in pretty much every normal subject it +responds more to faces than to any other + + align:start position:0% +responds more to faces than to any other + + + align:start position:0% +responds more to faces than to any other +kind of stimuli anyone has ever tested + + align:start position:0% +kind of stimuli anyone has ever tested + + + align:start position:0% +kind of stimuli anyone has ever tested +let me just give you + + align:start position:0% +let me just give you + + + align:start position:0% +let me just give you +one example here if you haven't seen + + align:start position:0% +one example here if you haven't seen + + + align:start position:0% +one example here if you haven't seen +this stimulus before raise your hand if + + align:start position:0% +this stimulus before raise your hand if + + + align:start position:0% +this stimulus before raise your hand if +you can tell what it is + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +raise your hand if you can tell what + + align:start position:0% +raise your hand if you can tell what + + + align:start position:0% +raise your hand if you can tell what +that is + + align:start position:0% +that is + + + align:start position:0% +that is +okay some of you didn't quite get it yet + + align:start position:0% +okay some of you didn't quite get it yet + + + align:start position:0% +okay some of you didn't quite get it yet +if you don't see it don't worry there's + + align:start position:0% +if you don't see it don't worry there's + + + align:start position:0% +if you don't see it don't worry there's +nothing wrong with you it's a little + + align:start position:0% +nothing wrong with you it's a little + + + align:start position:0% +nothing wrong with you it's a little +subtle + + align:start position:0% +subtle + + + align:start position:0% +subtle +it's a face in profile eyes nose mouth + + align:start position:0% +it's a face in profile eyes nose mouth + + + align:start position:0% +it's a face in profile eyes nose mouth +everyone got it + + align:start position:0% +everyone got it + + + align:start position:0% +everyone got it +okay so here's the thing that's the same + + align:start position:0% +okay so here's the thing that's the same + + + align:start position:0% +okay so here's the thing that's the same +stimulus it's just upside down another + + align:start position:0% +stimulus it's just upside down another + + + align:start position:0% +stimulus it's just upside down another +version of the face inversion effect + + align:start position:0% +version of the face inversion effect + + + align:start position:0% +version of the face inversion effect +in this case you can't even make + + align:start position:0% +in this case you can't even make + + + align:start position:0% +in this case you can't even make +yourself see the face when it's upside + + align:start position:0% +yourself see the face when it's upside + + + align:start position:0% +yourself see the face when it's upside +down if you think you see the the upside + + align:start position:0% +down if you think you see the the upside + + + align:start position:0% +down if you think you see the the upside +down version of the face you probably + + align:start position:0% +down version of the face you probably + + + align:start position:0% +down version of the face you probably +have the wrong bits the thing you think + + align:start position:0% +have the wrong bits the thing you think + + + align:start position:0% +have the wrong bits the thing you think +is the nose probably isn't etc okay so + + align:start position:0% +is the nose probably isn't etc okay so + + + align:start position:0% +is the nose probably isn't etc okay so +this is an extreme version of the face + + align:start position:0% +this is an extreme version of the face + + + align:start position:0% +this is an extreme version of the face +inversion effect and it's a gift to an + + align:start position:0% +inversion effect and it's a gift to an + + + align:start position:0% +inversion effect and it's a gift to an +experimental psychologist + + align:start position:0% +experimental psychologist + + + align:start position:0% +experimental psychologist +why is that such a gift + + align:start position:0% +why is that such a gift + + + align:start position:0% +why is that such a gift +because it's the same damn stimulus but + + align:start position:0% +because it's the same damn stimulus but + + + align:start position:0% +because it's the same damn stimulus but +in one case you see a face and another + + align:start position:0% +in one case you see a face and another + + + align:start position:0% +in one case you see a face and another +case you don't all we did was tip it + + align:start position:0% +case you don't all we did was tip it + + + align:start position:0% +case you don't all we did was tip it +upside down + + align:start position:0% +upside down + + + align:start position:0% +upside down +and the response of the fusiform face + + align:start position:0% +and the response of the fusiform face + + + align:start position:0% +and the response of the fusiform face +area is much stronger + + align:start position:0% +area is much stronger + + + align:start position:0% +area is much stronger +to the upright version when you see the + + align:start position:0% +to the upright version when you see the + + + align:start position:0% +to the upright version when you see the +face than to the inverted version when + + align:start position:0% +face than to the inverted version when + + + align:start position:0% +face than to the inverted version when +you don't + + align:start position:0% +you don't + + + align:start position:0% +you don't +so that enables us to + + align:start position:0% +so that enables us to + + + align:start position:0% +so that enables us to +stifle a whole line of attack from all + + align:start position:0% +stifle a whole line of attack from all + + + align:start position:0% +stifle a whole line of attack from all +of these hardcore vision people + + align:start position:0% +of these hardcore vision people + + + align:start position:0% +of these hardcore vision people +who early on said cowisher your face + + align:start position:0% +who early on said cowisher your face + + + align:start position:0% +who early on said cowisher your face +area isn't really selective for faces + + align:start position:0% +area isn't really selective for faces + + + align:start position:0% +area isn't really selective for faces +it's respect it's selective for these uh + + align:start position:0% +it's respect it's selective for these uh + + + align:start position:0% +it's respect it's selective for these uh +spatial frequencies or those that kind + + align:start position:0% +spatial frequencies or those that kind + + + align:start position:0% +spatial frequencies or those that kind +of contrast or this kind of shading + + align:start position:0% +of contrast or this kind of shading + + + align:start position:0% +of contrast or this kind of shading +information it's like no same stimulus + + align:start position:0% +information it's like no same stimulus + + + align:start position:0% +information it's like no same stimulus +it's just upside down it makes all the + + align:start position:0% +it's just upside down it makes all the + + + align:start position:0% +it's just upside down it makes all the +difference it's really whether you see a + + align:start position:0% +difference it's really whether you see a + + + align:start position:0% +difference it's really whether you see a +face or not yeah when you're measuring + + align:start position:0% +face or not yeah when you're measuring + + + align:start position:0% +face or not yeah when you're measuring +the response of that example + + align:start position:0% +the response of that example + + + align:start position:0% +the response of that example +did you like did you have it so that at + + align:start position:0% +did you like did you have it so that at + + + align:start position:0% +did you like did you have it so that at +first when people that the first time + + align:start position:0% +first when people that the first time + + + align:start position:0% +first when people that the first time +didn't recognize it and then you told + + align:start position:0% +didn't recognize it and then you told + + + align:start position:0% +didn't recognize it and then you told +them we did that later not in this + + align:start position:0% +them we did that later not in this + + + align:start position:0% +them we did that later not in this +experiment but we did that later and + + align:start position:0% +experiment but we did that later and + + + align:start position:0% +experiment but we did that later and +then look to see like what + + align:start position:0% +then look to see like what + + + align:start position:0% +then look to see like what +um + + align:start position:0% +um + + + align:start position:0% +um +okay so uh it's a great question and + + align:start position:0% +okay so uh it's a great question and + + + align:start position:0% +okay so uh it's a great question and +there's a lot you could do with that and + + align:start position:0% +there's a lot you could do with that and + + + align:start position:0% +there's a lot you could do with that and +actually i think other people have + + align:start position:0% +actually i think other people have + + + align:start position:0% +actually i think other people have +published studies like that since i + + align:start position:0% +published studies like that since i + + + align:start position:0% +published studies like that since i +can't quite remember who all has done it + + align:start position:0% +can't quite remember who all has done it + + + align:start position:0% +can't quite remember who all has done it +um + + align:start position:0% +um + + + align:start position:0% +um +but what we did was most of our subjects + + align:start position:0% +but what we did was most of our subjects + + + align:start position:0% +but what we did was most of our subjects +especially in the context of a whole + + align:start position:0% +especially in the context of a whole + + + align:start position:0% +especially in the context of a whole +experiment we chose stimuli so that most + + align:start position:0% +experiment we chose stimuli so that most + + + align:start position:0% +experiment we chose stimuli so that most +people could see the face in most of the + + align:start position:0% +people could see the face in most of the + + + align:start position:0% +people could see the face in most of the +upright stimuli and most people could + + align:start position:0% +upright stimuli and most people could + + + align:start position:0% +upright stimuli and most people could +not see the face in most of the inverted + + align:start position:0% +not see the face in most of the inverted + + + align:start position:0% +not see the face in most of the inverted +stimuli it wasn't perfect at all they + + align:start position:0% +stimuli it wasn't perfect at all they + + + align:start position:0% +stimuli it wasn't perfect at all they +didn't see faces in all of the upright + + align:start position:0% +didn't see faces in all of the upright + + + align:start position:0% +didn't see faces in all of the upright +ones and they didn't fail to see them in + + align:start position:0% +ones and they didn't fail to see them in + + + align:start position:0% +ones and they didn't fail to see them in +all of the inverted ones + + align:start position:0% +all of the inverted ones + + + align:start position:0% +all of the inverted ones +and that's probably why this difference + + align:start position:0% +and that's probably why this difference + + + align:start position:0% +and that's probably why this difference +in response is not you know two to one + + align:start position:0% +in response is not you know two to one + + + align:start position:0% +in response is not you know two to one +it's but it's close + + align:start position:0% +it's but it's close + + + align:start position:0% +it's but it's close +but you could do lots of other + + align:start position:0% +but you could do lots of other + + + align:start position:0% +but you could do lots of other +experiments like that and you should + + align:start position:0% +experiments like that and you should + + + align:start position:0% +experiments like that and you should +think about what kinds of designs would + + align:start position:0% +think about what kinds of designs would + + + align:start position:0% +think about what kinds of designs would +be good ones to do + + align:start position:0% +be good ones to do + + + align:start position:0% +be good ones to do +and what it would enable you to test + + align:start position:0% +and what it would enable you to test + + + align:start position:0% +and what it would enable you to test +exactly + + align:start position:0% +exactly + + + align:start position:0% +exactly +okay + + align:start position:0% +okay + + + align:start position:0% +okay +all right + + align:start position:0% +all right + + + align:start position:0% +all right +um + + align:start position:0% +um + + + align:start position:0% +um +so okay i'm as usual taking too long to + + align:start position:0% +so okay i'm as usual taking too long to + + + align:start position:0% +so okay i'm as usual taking too long to +do things so i'm just going to throw out + + align:start position:0% +do things so i'm just going to throw out + + + align:start position:0% +do things so i'm just going to throw out +some questions for you to percolate on + + align:start position:0% +some questions for you to percolate on + + + align:start position:0% +some questions for you to percolate on +and we will come back to them later in + + align:start position:0% +and we will come back to them later in + + + align:start position:0% +and we will come back to them later in +the course + + align:start position:0% +the course + + + align:start position:0% +the course +do these data the fact that you can see + + align:start position:0% +do these data the fact that you can see + + + align:start position:0% +do these data the fact that you can see +this so robustly in all subjects and + + align:start position:0% +this so robustly in all subjects and + + + align:start position:0% +this so robustly in all subjects and +that all this evidence suggests it's + + align:start position:0% +that all this evidence suggests it's + + + align:start position:0% +that all this evidence suggests it's +really very selective for faces + + align:start position:0% +really very selective for faces + + + align:start position:0% +really very selective for faces +does that tell us that this region is + + align:start position:0% +does that tell us that this region is + + + align:start position:0% +does that tell us that this region is +innate + + align:start position:0% + + + + align:start position:0% + +it's in the same place more or less than + + align:start position:0% +it's in the same place more or less than + + + align:start position:0% +it's in the same place more or less than +pretty much everyone + + align:start position:0% +pretty much everyone + + + align:start position:0% +pretty much everyone +does that mean it's innate + + align:start position:0% +does that mean it's innate + + + align:start position:0% +does that mean it's innate +think about it + + align:start position:0% +think about it + + + align:start position:0% +think about it +okay it's not immediately obvious + + align:start position:0% +okay it's not immediately obvious + + + align:start position:0% +okay it's not immediately obvious +another question + + align:start position:0% +another question + + + align:start position:0% +another question +does the fact that this thing responds + + align:start position:0% +does the fact that this thing responds + + + align:start position:0% +does the fact that this thing responds +so selectively to faces in pretty much + + align:start position:0% +so selectively to faces in pretty much + + + align:start position:0% +so selectively to faces in pretty much +everyone + + align:start position:0% +everyone + + + align:start position:0% +everyone +um + + align:start position:0% +um + + + align:start position:0% +um +mean that it's necessary for face + + align:start position:0% +mean that it's necessary for face + + + align:start position:0% +mean that it's necessary for face +recognition + + align:start position:0% + + + + align:start position:0% + +what do you guys think about that + + align:start position:0% + + + + align:start position:0% + +in the sense of like does that + + align:start position:0% +in the sense of like does that + + + align:start position:0% +in the sense of like does that +necessarily mean that if you lost that + + align:start position:0% +necessarily mean that if you lost that + + + align:start position:0% +necessarily mean that if you lost that +thing you wouldn't be able to recognize + + align:start position:0% +thing you wouldn't be able to recognize + + + align:start position:0% +thing you wouldn't be able to recognize +faces isabelle is that isabelle yes um + + align:start position:0% +faces isabelle is that isabelle yes um + + + align:start position:0% +faces isabelle is that isabelle yes um +well + + align:start position:0% +well + + + align:start position:0% +well +i would think would you really test that + + align:start position:0% +i would think would you really test that + + + align:start position:0% +i would think would you really test that +i promise you + + align:start position:0% +i promise you + + + align:start position:0% +i promise you +um + + align:start position:0% + + + + align:start position:0% + +exactly + + align:start position:0% +exactly + + + align:start position:0% +exactly +exactly + + align:start position:0% +exactly + + + align:start position:0% +exactly +exactly and we'll talk more about that + + align:start position:0% +exactly and we'll talk more about that + + + align:start position:0% +exactly and we'll talk more about that +in a moment the critical thing is that + + align:start position:0% +in a moment the critical thing is that + + + align:start position:0% +in a moment the critical thing is that +it's fabulous and powerful and cool to + + align:start position:0% +it's fabulous and powerful and cool to + + + align:start position:0% +it's fabulous and powerful and cool to +be able to find this thing in everybody + + align:start position:0% +be able to find this thing in everybody + + + align:start position:0% +be able to find this thing in everybody +measure its response it's taken us very + + align:start position:0% +measure its response it's taken us very + + + align:start position:0% +measure its response it's taken us very +far but + + align:start position:0% +far but + + + align:start position:0% +far but +just the fact that people have that + + align:start position:0% +just the fact that people have that + + + align:start position:0% +just the fact that people have that +thing doesn't tell us that you need it + + align:start position:0% +thing doesn't tell us that you need it + + + align:start position:0% +thing doesn't tell us that you need it +for face recognition it just tells you + + align:start position:0% +for face recognition it just tells you + + + align:start position:0% +for face recognition it just tells you +what turns on when you recognize faces + + align:start position:0% +what turns on when you recognize faces + + + align:start position:0% +what turns on when you recognize faces +okay + + align:start position:0% +okay + + + align:start position:0% +okay +this is really important we'll + + align:start position:0% +this is really important we'll + + + align:start position:0% +this is really important we'll +keep coming around to this + + align:start position:0% +keep coming around to this + + + align:start position:0% +keep coming around to this +um + + align:start position:0% +um + + + align:start position:0% +um +does this tell us how face recognition + + align:start position:0% +does this tell us how face recognition + + + align:start position:0% +does this tell us how face recognition +actually works in the human brain + + align:start position:0% +actually works in the human brain + + + align:start position:0% +actually works in the human brain +no + + align:start position:0% +no + + + align:start position:0% +no +i mean it's important but it's like + + align:start position:0% +i mean it's important but it's like + + + align:start position:0% +i mean it's important but it's like +barely step zero unfortunately the field + + align:start position:0% +barely step zero unfortunately the field + + + align:start position:0% +barely step zero unfortunately the field +is kind of still at step zero for most + + align:start position:0% +is kind of still at step zero for most + + + align:start position:0% +is kind of still at step zero for most +things + + align:start position:0% +things + + + align:start position:0% +things +uh step zero is better than i guess i + + align:start position:0% +uh step zero is better than i guess i + + + align:start position:0% +uh step zero is better than i guess i +don't know maybe i should call it step + + align:start position:0% +don't know maybe i should call it step + + + align:start position:0% +don't know maybe i should call it step +one uh anyway it's something but we + + align:start position:0% +one uh anyway it's something but we + + + align:start position:0% +one uh anyway it's something but we +doesn't tell us how it works + + align:start position:0% +doesn't tell us how it works + + + align:start position:0% +doesn't tell us how it works +okay + + align:start position:0% +okay + + + align:start position:0% +okay +all right so advantages and + + align:start position:0% +all right so advantages and + + + align:start position:0% +all right so advantages and +disadvantages of functional mri + + align:start position:0% +disadvantages of functional mri + + + align:start position:0% +disadvantages of functional mri +advantages it is as i mentioned last + + align:start position:0% +advantages it is as i mentioned last + + + align:start position:0% +advantages it is as i mentioned last +time the best spatial resolution + + align:start position:0% +time the best spatial resolution + + + align:start position:0% +time the best spatial resolution +available for studies on normal subjects + + align:start position:0% +available for studies on normal subjects + + + align:start position:0% +available for studies on normal subjects +without opening their heads okay + + align:start position:0% +without opening their heads okay + + + align:start position:0% +without opening their heads okay +that's what it means to say non-invasive + + align:start position:0% +that's what it means to say non-invasive + + + align:start position:0% +that's what it means to say non-invasive +disadvantages + + align:start position:0% +disadvantages + + + align:start position:0% +disadvantages +as i just said we don't know just + + align:start position:0% +as i just said we don't know just + + + align:start position:0% +as i just said we don't know just +because we see a response there doesn't + + align:start position:0% +because we see a response there doesn't + + + align:start position:0% +because we see a response there doesn't +mean that that region is causally + + align:start position:0% +mean that that region is causally + + + align:start position:0% +mean that that region is causally +involved in perception or cognition or + + align:start position:0% +involved in perception or cognition or + + + align:start position:0% +involved in perception or cognition or +experience + + align:start position:0% + + + + align:start position:0% + +we don't know exactly what is going on + + align:start position:0% +we don't know exactly what is going on + + + align:start position:0% +we don't know exactly what is going on +at a neural level underlying that bold + + align:start position:0% +at a neural level underlying that bold + + + align:start position:0% +at a neural level underlying that bold +response that blood flow change it could + + align:start position:0% +response that blood flow change it could + + + align:start position:0% +response that blood flow change it could +be any metabolic change not necessarily + + align:start position:0% +be any metabolic change not necessarily + + + align:start position:0% +be any metabolic change not necessarily +neuronal spiking okay so it's a little + + align:start position:0% +neuronal spiking okay so it's a little + + + align:start position:0% +neuronal spiking okay so it's a little +bit it's very indirect and a little + + align:start position:0% +bit it's very indirect and a little + + + align:start position:0% +bit it's very indirect and a little +imprecise + + align:start position:0% +imprecise + + + align:start position:0% +imprecise +spatial resolution is much better than + + align:start position:0% +spatial resolution is much better than + + + align:start position:0% +spatial resolution is much better than +anything else in humans but it's + + align:start position:0% +anything else in humans but it's + + + align:start position:0% +anything else in humans but it's +appallingly bad compared to + + align:start position:0% +appallingly bad compared to + + + align:start position:0% +appallingly bad compared to +anything that people who work on animals + + align:start position:0% +anything that people who work on animals + + + align:start position:0% +anything that people who work on animals +can do or they routinely record from + + align:start position:0% +can do or they routinely record from + + + align:start position:0% +can do or they routinely record from +individual neurons or you know even + + align:start position:0% +individual neurons or you know even + + + align:start position:0% +individual neurons or you know even +dendrites on a + + align:start position:0% +dendrites on a + + + align:start position:0% +dendrites on a +on a neuron + + align:start position:0% +on a neuron + + + align:start position:0% +on a neuron +we are summing over + + align:start position:0% +we are summing over + + + align:start position:0% +we are summing over +hundreds of thousands of neurons in each + + align:start position:0% +hundreds of thousands of neurons in each + + + align:start position:0% +hundreds of thousands of neurons in each +pixel or voxel that we measure with + + align:start position:0% +pixel or voxel that we measure with + + + align:start position:0% +pixel or voxel that we measure with +functional mri + + align:start position:0% +functional mri + + + align:start position:0% +functional mri +it's very expensive + + align:start position:0% +it's very expensive + + + align:start position:0% +it's very expensive +it's a little cheaper than that here but + + align:start position:0% +it's a little cheaper than that here but + + + align:start position:0% +it's a little cheaper than that here but +in most places it's more than 600 bucks + + align:start position:0% +in most places it's more than 600 bucks + + + align:start position:0% +in most places it's more than 600 bucks +an hour that is a lot + + align:start position:0% +an hour that is a lot + + + align:start position:0% +an hour that is a lot +um there are other + + align:start position:0% +um there are other + + + align:start position:0% +um there are other +they're parts of the brain where it's + + align:start position:0% +they're parts of the brain where it's + + + align:start position:0% +they're parts of the brain where it's +really hard to get any signal for + + align:start position:0% +really hard to get any signal for + + + align:start position:0% +really hard to get any signal for +various physics he + + align:start position:0% +various physics he + + + align:start position:0% +various physics he +reasons + + align:start position:0% + + + + align:start position:0% + +and it makes a loud noise which is not + + align:start position:0% +and it makes a loud noise which is not + + + align:start position:0% +and it makes a loud noise which is not +always a problem but it's a problem for + + align:start position:0% +always a problem but it's a problem for + + + align:start position:0% +always a problem but it's a problem for +some things like scanning infants or + + align:start position:0% +some things like scanning infants or + + + align:start position:0% +some things like scanning infants or +like doing auditory experiments + + align:start position:0% + + + + align:start position:0% + +the temporal resolution + + align:start position:0% +the temporal resolution + + + align:start position:0% +the temporal resolution +is not even close to the time scale on + + align:start position:0% +is not even close to the time scale on + + + align:start position:0% +is not even close to the time scale on +which vision happens okay so vision is + + align:start position:0% +which vision happens okay so vision is + + + align:start position:0% +which vision happens okay so vision is +really fast + + align:start position:0% +really fast + + + align:start position:0% +really fast +um + + align:start position:0% +um + + + align:start position:0% +um +and + + align:start position:0% +and + + + align:start position:0% +and +functional mri is really slow + + align:start position:0% +functional mri is really slow + + + align:start position:0% +functional mri is really slow +right it's slow why is it slow + + align:start position:0% + + + + align:start position:0% + +yeah blood levels take time to change + + align:start position:0% +yeah blood levels take time to change + + + align:start position:0% +yeah blood levels take time to change +yeah just takes a long time for blood + + align:start position:0% +yeah just takes a long time for blood + + + align:start position:0% +yeah just takes a long time for blood +blood flow to change after the increase + + align:start position:0% +blood flow to change after the increase + + + align:start position:0% +blood flow to change after the increase +in neural activity + + align:start position:0% +in neural activity + + + align:start position:0% +in neural activity +all right + + align:start position:0% +all right + + + align:start position:0% +all right +okay so back to our questions that we're + + align:start position:0% +okay so back to our questions that we're + + + align:start position:0% +okay so back to our questions that we're +asking about face perception where did + + align:start position:0% +asking about face perception where did + + + align:start position:0% +asking about face perception where did +we get with functional mri well actually + + align:start position:0% +we get with functional mri well actually + + + align:start position:0% +we get with functional mri well actually +from both behavior and functional mri it + + align:start position:0% +from both behavior and functional mri it + + + align:start position:0% +from both behavior and functional mri it +kind of looks like we have a distinct + + align:start position:0% +kind of looks like we have a distinct + + + align:start position:0% +kind of looks like we have a distinct +system for recognizing faces than for + + align:start position:0% +system for recognizing faces than for + + + align:start position:0% +system for recognizing faces than for +for recognizing everything else + + align:start position:0% +for recognizing everything else + + + align:start position:0% +for recognizing everything else +i don't think we've totally nailed it + + align:start position:0% +i don't think we've totally nailed it + + + align:start position:0% +i don't think we've totally nailed it +yes quick question regardless + + align:start position:0% +yes quick question regardless + + + align:start position:0% +yes quick question regardless +so it's uh the resolution is the order + + align:start position:0% +so it's uh the resolution is the order + + + align:start position:0% +so it's uh the resolution is the order +of like a couple of seconds + + align:start position:0% +of like a couple of seconds + + + align:start position:0% +of like a couple of seconds +yeah some people would say you could get + + align:start position:0% +yeah some people would say you could get + + + align:start position:0% +yeah some people would say you could get +it down to a couple hundred milliseconds + + align:start position:0% +it down to a couple hundred milliseconds + + + align:start position:0% +it down to a couple hundred milliseconds +but that's debated you have you have to + + align:start position:0% +but that's debated you have you have to + + + align:start position:0% +but that's debated you have you have to +go to great lengths to do that normal + + align:start position:0% +go to great lengths to do that normal + + + align:start position:0% +go to great lengths to do that normal +functional mri a couple seconds at best + + align:start position:0% + + + + align:start position:0% + +all right + + align:start position:0% +all right + + + align:start position:0% +all right +so let's let's consider this next + + align:start position:0% +so let's let's consider this next + + + align:start position:0% +so let's let's consider this next +question how fast does face recognition + + align:start position:0% +question how fast does face recognition + + + align:start position:0% +question how fast does face recognition +happen + + align:start position:0% +happen + + + align:start position:0% +happen +now that may seem like a completely + + align:start position:0% +now that may seem like a completely + + + align:start position:0% +now that may seem like a completely +arbitrary question to ask but it's not + + align:start position:0% +arbitrary question to ask but it's not + + + align:start position:0% +arbitrary question to ask but it's not +remember we're trying to understand the + + align:start position:0% +remember we're trying to understand the + + + align:start position:0% +remember we're trying to understand the +computations that are running in your + + align:start position:0% +computations that are running in your + + + align:start position:0% +computations that are running in your +head when you recognize faces + + align:start position:0% +head when you recognize faces + + + align:start position:0% +head when you recognize faces +and you might imagine some computations + + align:start position:0% +and you might imagine some computations + + + align:start position:0% +and you might imagine some computations +that are iterative that involve + + align:start position:0% +that are iterative that involve + + + align:start position:0% +that are iterative that involve +multiple repeated + + align:start position:0% +multiple repeated + + + align:start position:0% +multiple repeated +testing of hypotheses generative models + + align:start position:0% +testing of hypotheses generative models + + + align:start position:0% +testing of hypotheses generative models +whatever things that involve lots of + + align:start position:0% +whatever things that involve lots of + + + align:start position:0% +whatever things that involve lots of +iterated feedback versus things where + + align:start position:0% +iterated feedback versus things where + + + align:start position:0% +iterated feedback versus things where +you just have a feed-forward sweep of + + align:start position:0% +you just have a feed-forward sweep of + + + align:start position:0% +you just have a feed-forward sweep of +the visual system and so there might be + + align:start position:0% +the visual system and so there might be + + + align:start position:0% +the visual system and so there might be +very different time scales for those + + align:start position:0% +very different time scales for those + + + align:start position:0% +very different time scales for those +different kinds of + + align:start position:0% +different kinds of + + + align:start position:0% +different kinds of +mental processes + + align:start position:0% +mental processes + + + align:start position:0% +mental processes +uh so we just went through this + + align:start position:0% +uh so we just went through this + + + align:start position:0% +uh so we just went through this +functional mri is not going to answer + + align:start position:0% +functional mri is not going to answer + + + align:start position:0% +functional mri is not going to answer +this question it's just not it's a + + align:start position:0% +this question it's just not it's a + + + align:start position:0% +this question it's just not it's a +bummer but that's life we're adults + + align:start position:0% +bummer but that's life we're adults + + + align:start position:0% +bummer but that's life we're adults +we're going to just move on and use a + + align:start position:0% +we're going to just move on and use a + + + align:start position:0% +we're going to just move on and use a +different method + + align:start position:0% +different method + + + align:start position:0% +different method +okay so there's a bunch of different + + align:start position:0% +okay so there's a bunch of different + + + align:start position:0% +okay so there's a bunch of different +methods one is i kind of been around + + align:start position:0% +methods one is i kind of been around + + + align:start position:0% +methods one is i kind of been around +forever you glue electrodes on the head + + align:start position:0% +forever you glue electrodes on the head + + + align:start position:0% +forever you glue electrodes on the head +right sometimes you push the hair apart + + align:start position:0% +right sometimes you push the hair apart + + + align:start position:0% +right sometimes you push the hair apart +or try to find bald people and glue + + align:start position:0% +or try to find bald people and glue + + + align:start position:0% +or try to find bald people and glue +electrodes right on there and you can + + align:start position:0% +electrodes right on there and you can + + + align:start position:0% +electrodes right on there and you can +use in the old days you know about 10 + + align:start position:0% +use in the old days you know about 10 + + + align:start position:0% +use in the old days you know about 10 +electrodes or you can use in more modern + + align:start position:0% +electrodes or you can use in more modern + + + align:start position:0% +electrodes or you can use in more modern +devices these nets with you know a few + + align:start position:0% +devices these nets with you know a few + + + align:start position:0% +devices these nets with you know a few +hundred + + align:start position:0% +hundred + + + align:start position:0% +hundred +electrodes that you settle onto the head + + align:start position:0% +electrodes that you settle onto the head + + + align:start position:0% +electrodes that you settle onto the head +and so then you just measure directly + + align:start position:0% +and so then you just measure directly + + + align:start position:0% +and so then you just measure directly +electrical potentials right on the scalp + + align:start position:0% +electrical potentials right on the scalp + + + align:start position:0% +electrical potentials right on the scalp +okay so what's cool about that is it's + + align:start position:0% +okay so what's cool about that is it's + + + align:start position:0% +okay so what's cool about that is it's +totally non-invasive and it gives you a + + align:start position:0% +totally non-invasive and it gives you a + + + align:start position:0% +totally non-invasive and it gives you a +beautiful online temporal measure of + + align:start position:0% +beautiful online temporal measure of + + + align:start position:0% +beautiful online temporal measure of +underlying neural activity + + align:start position:0% +underlying neural activity + + + align:start position:0% +underlying neural activity +what's not so cool about it is that + + align:start position:0% +what's not so cool about it is that + + + align:start position:0% +what's not so cool about it is that +electrical potentials blur all over the + + align:start position:0% +electrical potentials blur all over the + + + align:start position:0% +electrical potentials blur all over the +scalp and the spatial resolution is + + align:start position:0% +scalp and the spatial resolution is + + + align:start position:0% +scalp and the spatial resolution is +really awful + + align:start position:0% +really awful + + + align:start position:0% +really awful +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so the analogy has been made + + align:start position:0% +so the analogy has been made + + + align:start position:0% +so the analogy has been made +that it will be like sticking a + + align:start position:0% +that it will be like sticking a + + + align:start position:0% +that it will be like sticking a +microphone on the um inside of the top + + align:start position:0% +microphone on the um inside of the top + + + align:start position:0% +microphone on the um inside of the top +of a football stadium + + align:start position:0% +of a football stadium + + + align:start position:0% +of a football stadium +and collecting audio there like you + + align:start position:0% +and collecting audio there like you + + + align:start position:0% +and collecting audio there like you +would know + + align:start position:0% +would know + + + align:start position:0% +would know +when a touchdown was scored there's a + + align:start position:0% +when a touchdown was scored there's a + + + align:start position:0% +when a touchdown was scored there's a +lot of noise all over it's like okay + + align:start position:0% +lot of noise all over it's like okay + + + align:start position:0% +lot of noise all over it's like okay +there's an event we detected that event + + align:start position:0% +there's an event we detected that event + + + align:start position:0% +there's an event we detected that event +right you might be able to tell a touch + + align:start position:0% +right you might be able to tell a touch + + + align:start position:0% +right you might be able to tell a touch +ball from a touchdown from something + + align:start position:0% +ball from a touchdown from something + + + align:start position:0% +ball from a touchdown from something +else i don't know about football so i + + align:start position:0% +else i don't know about football so i + + + align:start position:0% +else i don't know about football so i +can't tell you what else anyway + + align:start position:0% +can't tell you what else anyway + + + align:start position:0% +can't tell you what else anyway +something else some other event that + + align:start position:0% +something else some other event that + + + align:start position:0% +something else some other event that +could happen okay + + align:start position:0% +could happen okay + + + align:start position:0% +could happen okay +um + + align:start position:0% +um + + + align:start position:0% +um +so that will be useful for some things + + align:start position:0% +so that will be useful for some things + + + align:start position:0% +so that will be useful for some things +but kind of crude + + align:start position:0% +but kind of crude + + + align:start position:0% +but kind of crude +um + + align:start position:0% +um + + + align:start position:0% +um +but you'd have a hell of a time telling + + align:start position:0% +but you'd have a hell of a time telling + + + align:start position:0% +but you'd have a hell of a time telling +anything else like what one person is + + align:start position:0% +anything else like what one person is + + + align:start position:0% +anything else like what one person is +saying to another person in the + + align:start position:0% +saying to another person in the + + + align:start position:0% +saying to another person in the +bleachers okay + + align:start position:0% +bleachers okay + + + align:start position:0% +bleachers okay +so that's the old analogy this is + + align:start position:0% +so that's the old analogy this is + + + align:start position:0% +so that's the old analogy this is +changing slightly + + align:start position:0% +changing slightly + + + align:start position:0% +changing slightly +um and i will get to that later + + align:start position:0% +um and i will get to that later + + + align:start position:0% +um and i will get to that later +but first i want to briefly mention the + + align:start position:0% +but first i want to briefly mention the + + + align:start position:0% +but first i want to briefly mention the +one of the assigned readings that i just + + align:start position:0% +one of the assigned readings that i just + + + align:start position:0% +one of the assigned readings that i just +hoped you guys could figure out on your + + align:start position:0% +hoped you guys could figure out on your + + + align:start position:0% +hoped you guys could figure out on your +own but just in case you were confused + + align:start position:0% +own but just in case you were confused + + + align:start position:0% +own but just in case you were confused +about it the point i wanted you to get + + align:start position:0% +about it the point i wanted you to get + + + align:start position:0% +about it the point i wanted you to get +from the thorpe reading + + align:start position:0% +from the thorpe reading + + + align:start position:0% +from the thorpe reading +is he's asking how how quickly can we + + align:start position:0% +is he's asking how how quickly can we + + + align:start position:0% +is he's asking how how quickly can we +tell if an image contains an animal or + + align:start position:0% +tell if an image contains an animal or + + + align:start position:0% +tell if an image contains an animal or +not it's a kind of way to say how fast + + align:start position:0% +not it's a kind of way to say how fast + + + align:start position:0% +not it's a kind of way to say how fast +is object recognition okay + + align:start position:0% +is object recognition okay + + + align:start position:0% +is object recognition okay +so what does he do he has people look at + + align:start position:0% +so what does he do he has people look at + + + align:start position:0% +so what does he do he has people look at +a bunch of images and they press a + + align:start position:0% +a bunch of images and they press a + + + align:start position:0% +a bunch of images and they press a +button if this button if it's an has an + + align:start position:0% +button if this button if it's an has an + + + align:start position:0% +button if this button if it's an has an +animal and this button if it doesn't + + align:start position:0% +animal and this button if it doesn't + + + align:start position:0% +animal and this button if it doesn't +really simple task + + align:start position:0% +really simple task + + + align:start position:0% +really simple task +so first question is why not just use + + align:start position:0% +so first question is why not just use + + + align:start position:0% +so first question is why not just use +those reaction times we can measure how + + align:start position:0% +those reaction times we can measure how + + + align:start position:0% +those reaction times we can measure how +fast it takes for people to press a + + align:start position:0% +fast it takes for people to press a + + + align:start position:0% +fast it takes for people to press a +button after the image comes on why not + + align:start position:0% +button after the image comes on why not + + + align:start position:0% +button after the image comes on why not +just use that + + align:start position:0% +just use that + + + align:start position:0% +just use that +does that tell us how fast object + + align:start position:0% +does that tell us how fast object + + + align:start position:0% +does that tell us how fast object +recognition occurs + + align:start position:0% +recognition occurs + + + align:start position:0% +recognition occurs +yeah jimmy it doesn't because if you + + align:start position:0% +yeah jimmy it doesn't because if you + + + align:start position:0% +yeah jimmy it doesn't because if you +perceive it and then you it also + + align:start position:0% +perceive it and then you it also + + + align:start position:0% +perceive it and then you it also +activates the motor neurons + + align:start position:0% +activates the motor neurons + + + align:start position:0% +activates the motor neurons +yeah i have to take all that time to + + align:start position:0% +yeah i have to take all that time to + + + align:start position:0% +yeah i have to take all that time to +figure out okay i see the animal okay + + align:start position:0% +figure out okay i see the animal okay + + + align:start position:0% +figure out okay i see the animal okay +which button is that and then like which + + align:start position:0% +which button is that and then like which + + + align:start position:0% +which button is that and then like which +finger do i push and then you got to + + align:start position:0% +finger do i push and then you got to + + + align:start position:0% +finger do i push and then you got to +send a signal all the way down here + + align:start position:0% +send a signal all the way down here + + + align:start position:0% +send a signal all the way down here +conduction velocity all the way out down + + align:start position:0% +conduction velocity all the way out down + + + align:start position:0% +conduction velocity all the way out down +to your finger that takes a long time + + align:start position:0% +to your finger that takes a long time + + + align:start position:0% +to your finger that takes a long time +and so it includes all that motor stuff + + align:start position:0% +and so it includes all that motor stuff + + + align:start position:0% +and so it includes all that motor stuff +in with the perceptual stuff we can make + + align:start position:0% +in with the perceptual stuff we can make + + + align:start position:0% +in with the perceptual stuff we can make +some guesses about how long that + + align:start position:0% +some guesses about how long that + + + align:start position:0% +some guesses about how long that +motor stuff takes but it's still not + + align:start position:0% +motor stuff takes but it's still not + + + align:start position:0% +motor stuff takes but it's still not +very precise + + align:start position:0% +very precise + + + align:start position:0% +very precise +so the point of the thorpe paper is + + align:start position:0% +so the point of the thorpe paper is + + + align:start position:0% +so the point of the thorpe paper is +they're basically trying to collect a + + align:start position:0% +they're basically trying to collect a + + + align:start position:0% +they're basically trying to collect a +reaction time out of the neurons in the + + align:start position:0% +reaction time out of the neurons in the + + + align:start position:0% +reaction time out of the neurons in the +head right + + align:start position:0% +head right + + + align:start position:0% +head right +so they're trying to actually collect + + align:start position:0% +so they're trying to actually collect + + + align:start position:0% +so they're trying to actually collect +it's essentially what they're collecting + + align:start position:0% +it's essentially what they're collecting + + + align:start position:0% +it's essentially what they're collecting +in this case is more the motor response + + align:start position:0% +in this case is more the motor response + + + align:start position:0% +in this case is more the motor response +because they're collecting responses + + align:start position:0% +because they're collecting responses + + + align:start position:0% +because they're collecting responses +over frontal lobes right and we haven't + + align:start position:0% +over frontal lobes right and we haven't + + + align:start position:0% +over frontal lobes right and we haven't +talked about this much but all of the + + align:start position:0% +talked about this much but all of the + + + align:start position:0% +talked about this much but all of the +visual stuff we've been talking about + + align:start position:0% +visual stuff we've been talking about + + + align:start position:0% +visual stuff we've been talking about +all happens in the back of the head okay + + align:start position:0% +all happens in the back of the head okay + + + align:start position:0% +all happens in the back of the head okay +more motor planning stuff mostly happens + + align:start position:0% +more motor planning stuff mostly happens + + + align:start position:0% +more motor planning stuff mostly happens +in the front of the head and so they're + + align:start position:0% +in the front of the head and so they're + + + align:start position:0% +in the front of the head and so they're +collecting responses out of here + + align:start position:0% +collecting responses out of here + + + align:start position:0% +collecting responses out of here +averaging over a bunch of frontal + + align:start position:0% +averaging over a bunch of frontal + + + align:start position:0% +averaging over a bunch of frontal +responses and they see the average + + align:start position:0% +responses and they see the average + + + align:start position:0% +responses and they see the average +response when there's an animal this is + + align:start position:0% +response when there's an animal this is + + + align:start position:0% +response when there's an animal this is +just potential average over those + + align:start position:0% +just potential average over those + + + align:start position:0% +just potential average over those +frontal electrodes is like this and when + + align:start position:0% +frontal electrodes is like this and when + + + align:start position:0% +frontal electrodes is like this and when +there's no animal it's like that + + align:start position:0% +there's no animal it's like that + + + align:start position:0% +there's no animal it's like that +and so what does that tell us + + align:start position:0% +and so what does that tell us + + + align:start position:0% +and so what does that tell us +about how fast people can distinguish + + align:start position:0% +about how fast people can distinguish + + + align:start position:0% +about how fast people can distinguish +whether an image has an animal or not + + align:start position:0% + + + + align:start position:0% + +yes yeah it's less than that number + + align:start position:0% +yes yeah it's less than that number + + + align:start position:0% +yes yeah it's less than that number +less than + + align:start position:0% +less than + + + align:start position:0% +less than +1 516. okay why less than 150 + + align:start position:0% +1 516. okay why less than 150 + + + align:start position:0% +1 516. okay why less than 150 +i i've read the paper so it's kind of + + align:start position:0% +i i've read the paper so it's kind of + + + align:start position:0% +i i've read the paper so it's kind of +cheating that's okay that's good that's + + align:start position:0% +cheating that's okay that's good that's + + + align:start position:0% +cheating that's okay that's good that's +fine + + align:start position:0% +fine + + + align:start position:0% +fine +so + + align:start position:0% +so + + + align:start position:0% +so +it gives you like a bound + + align:start position:0% +it gives you like a bound + + + align:start position:0% +it gives you like a bound +uh the 150 second news giving you a + + align:start position:0% +uh the 150 second news giving you a + + + align:start position:0% +uh the 150 second news giving you a +bounce saying + + align:start position:0% +bounce saying + + + align:start position:0% +bounce saying +some process has been registered and now + + align:start position:0% +some process has been registered and now + + + align:start position:0% +some process has been registered and now +you're trying to do something else + + align:start position:0% +you're trying to do something else + + + align:start position:0% +you're trying to do something else +uh in the case of non-admins right + + align:start position:0% +uh in the case of non-admins right + + + align:start position:0% +uh in the case of non-admins right +so that's the deviation starts telling + + align:start position:0% +so that's the deviation starts telling + + + align:start position:0% +so that's the deviation starts telling +you that okay two different actions have + + align:start position:0% +you that okay two different actions have + + + align:start position:0% +you that okay two different actions have +started taking place yep so by that time + + align:start position:0% +started taking place yep so by that time + + + align:start position:0% +started taking place yep so by that time +the image ought to have been sort of + + align:start position:0% +the image ought to have been sort of + + + align:start position:0% +the image ought to have been sort of +fully processed so + + align:start position:0% +fully processed so + + + align:start position:0% +fully processed so +that should be something less than that + + align:start position:0% +that should be something less than that + + + align:start position:0% +that should be something less than that +number one yeah yeah i did everybody get + + align:start position:0% +number one yeah yeah i did everybody get + + + align:start position:0% +number one yeah yeah i did everybody get +that there's it's it's actually quite + + align:start position:0% +that there's it's it's actually quite + + + align:start position:0% +that there's it's it's actually quite +subtle so + + align:start position:0% +subtle so + + + align:start position:0% +subtle so +so the key thing is the these curves + + align:start position:0% +so the key thing is the these curves + + + align:start position:0% +so the key thing is the these curves +diverge right there at 150. so that + + align:start position:0% +diverge right there at 150. so that + + + align:start position:0% +diverge right there at 150. so that +tells you that by 150 milliseconds + + align:start position:0% +tells you that by 150 milliseconds + + + align:start position:0% +tells you that by 150 milliseconds +something in your brain is happening + + align:start position:0% +something in your brain is happening + + + align:start position:0% +something in your brain is happening +different if there's an animal and not + + align:start position:0% +different if there's an animal and not + + + align:start position:0% +different if there's an animal and not +an animal + + align:start position:0% +an animal + + + align:start position:0% +an animal +okay that's the key question but what is + + align:start position:0% +okay that's the key question but what is + + + align:start position:0% +okay that's the key question but what is +that something + + align:start position:0% +that something + + + align:start position:0% +that something +it may be your motor preparation of the + + align:start position:0% +it may be your motor preparation of the + + + align:start position:0% +it may be your motor preparation of the +response in that case the actual visual + + align:start position:0% +response in that case the actual visual + + + align:start position:0% +response in that case the actual visual +part happened before because you + + align:start position:0% +part happened before because you + + + align:start position:0% +part happened before because you +wouldn't know which button to press if + + align:start position:0% +wouldn't know which button to press if + + + align:start position:0% +wouldn't know which button to press if +you hadn't already recognized it okay + + align:start position:0% +you hadn't already recognized it okay + + + align:start position:0% +you hadn't already recognized it okay +so + + align:start position:0% +so + + + align:start position:0% +so +it's + + align:start position:0% +it's + + + align:start position:0% +it's +an upper bound for when that process + + align:start position:0% +an upper bound for when that process + + + align:start position:0% +an upper bound for when that process +happened because maybe it happened + + align:start position:0% +happened because maybe it happened + + + align:start position:0% +happened because maybe it happened +before and we're looking at a later + + align:start position:0% +before and we're looking at a later + + + align:start position:0% +before and we're looking at a later +stage + + align:start position:0% +stage + + + align:start position:0% +stage +okay + + align:start position:0% +okay + + + align:start position:0% +okay +does that make sense + + align:start position:0% +does that make sense + + + align:start position:0% +does that make sense +um but also it's an upper bound + + align:start position:0% +um but also it's an upper bound + + + align:start position:0% +um but also it's an upper bound +for the beginning of that process + + align:start position:0% +for the beginning of that process + + + align:start position:0% +for the beginning of that process +because the fact that those electrode + + align:start position:0% +because the fact that those electrode + + + align:start position:0% +because the fact that those electrode +responses have diverged doesn't mean + + align:start position:0% +responses have diverged doesn't mean + + + align:start position:0% +responses have diverged doesn't mean +you've finished processing whether it's + + align:start position:0% +you've finished processing whether it's + + + align:start position:0% +you've finished processing whether it's +an animal or not + + align:start position:0% +an animal or not + + + align:start position:0% +an animal or not +okay so it's kind of a subtle business + + align:start position:0% +okay so it's kind of a subtle business + + + align:start position:0% +okay so it's kind of a subtle business +reasoning from this + + align:start position:0% +reasoning from this + + + align:start position:0% +reasoning from this +okay + + align:start position:0% +okay + + + align:start position:0% +okay +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so + + align:start position:0% +so + + + align:start position:0% +so +um that's all that + + align:start position:0% +um that's all that + + + align:start position:0% +um that's all that +so um that's a case with detecting + + align:start position:0% +so um that's a case with detecting + + + align:start position:0% +so um that's a case with detecting +animals what about faces to get back to + + align:start position:0% +animals what about faces to get back to + + + align:start position:0% +animals what about faces to get back to +our theme for today + + align:start position:0% +our theme for today + + + align:start position:0% +our theme for today +um yes you can learn about the speed of + + align:start position:0% +um yes you can learn about the speed of + + + align:start position:0% +um yes you can learn about the speed of +face detection at least with erps and so + + align:start position:0% +face detection at least with erps and so + + + align:start position:0% +face detection at least with erps and so +here's the first paper that did that + + align:start position:0% +here's the first paper that did that + + + align:start position:0% +here's the first paper that did that +back in 1996 they had electrodes over + + align:start position:0% +back in 1996 they had electrodes over + + + align:start position:0% +back in 1996 they had electrodes over +where's where are these just right + + align:start position:0% +where's where are these just right + + + align:start position:0% +where's where are these just right +around here and here i actually have + + align:start position:0% +around here and here i actually have + + + align:start position:0% +around here and here i actually have +those electrode locations tattooed and + + align:start position:0% +those electrode locations tattooed and + + + align:start position:0% +those electrode locations tattooed and +my on my scalp + + align:start position:0% +my on my scalp + + + align:start position:0% +my on my scalp +color coded anyway yes is erp just + + align:start position:0% +color coded anyway yes is erp just + + + align:start position:0% +color coded anyway yes is erp just +the same as an eeg just specifically yes + + align:start position:0% +the same as an eeg just specifically yes + + + align:start position:0% +the same as an eeg just specifically yes +exactly um it is + + align:start position:0% +exactly um it is + + + align:start position:0% +exactly um it is +it's the same as an eeg except what you + + align:start position:0% +it's the same as an eeg except what you + + + align:start position:0% +it's the same as an eeg except what you +do is you + + align:start position:0% +do is you + + + align:start position:0% +do is you +time lock the data collection to + + align:start position:0% +time lock the data collection to + + + align:start position:0% +time lock the data collection to +stimulus onset so it actually stands for + + align:start position:0% +stimulus onset so it actually stands for + + + align:start position:0% +stimulus onset so it actually stands for +event related potential and the reason + + align:start position:0% +event related potential and the reason + + + align:start position:0% +event related potential and the reason +it's event related is you collect all + + align:start position:0% +it's event related is you collect all + + + align:start position:0% +it's event related is you collect all +those trials and you time lock to + + align:start position:0% +those trials and you time lock to + + + align:start position:0% +those trials and you time lock to +stimulus onset and then you signal + + align:start position:0% +stimulus onset and then you signal + + + align:start position:0% +stimulus onset and then you signal +average + + align:start position:0% +average + + + align:start position:0% +average +okay + + align:start position:0% +okay + + + align:start position:0% +okay +i had a slide on that but i took it out + + align:start position:0% +i had a slide on that but i took it out + + + align:start position:0% +i had a slide on that but i took it out +as to detail but that's exactly the idea + + align:start position:0% +as to detail but that's exactly the idea + + + align:start position:0% +as to detail but that's exactly the idea +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +so here stimulus onset is you know right + + align:start position:0% +so here stimulus onset is you know right + + + align:start position:0% +so here stimulus onset is you know right +around here this is time going this way + + align:start position:0% +around here this is time going this way + + + align:start position:0% +around here this is time going this way +and what you see it's hard to see here + + align:start position:0% +and what you see it's hard to see here + + + align:start position:0% +and what you see it's hard to see here +but the faces are right there and at 170 + + align:start position:0% +but the faces are right there and at 170 + + + align:start position:0% +but the faces are right there and at 170 +milliseconds after stimulus onset + + align:start position:0% +milliseconds after stimulus onset + + + align:start position:0% +milliseconds after stimulus onset +there's a bigger bump + + align:start position:0% +there's a bigger bump + + + align:start position:0% +there's a bigger bump +for faces at you know an electrode + + align:start position:0% +for faces at you know an electrode + + + align:start position:0% +for faces at you know an electrode +approximately here + + align:start position:0% +approximately here + + + align:start position:0% +approximately here +uh and even more so actually even more + + align:start position:0% +uh and even more so actually even more + + + align:start position:0% +uh and even more so actually even more +so over the right hemisphere right there + + align:start position:0% +so over the right hemisphere right there + + + align:start position:0% +so over the right hemisphere right there +okay compared to cars and scrambled + + align:start position:0% +okay compared to cars and scrambled + + + align:start position:0% +okay compared to cars and scrambled +faces and stuff like that yeah what is + + align:start position:0% +faces and stuff like that yeah what is + + + align:start position:0% +faces and stuff like that yeah what is +your exactly measuring is it just like + + align:start position:0% +your exactly measuring is it just like + + + align:start position:0% +your exactly measuring is it just like +activity yeah so again it's it's + + align:start position:0% +activity yeah so again it's it's + + + align:start position:0% +activity yeah so again it's it's +electrodes glued on your scalp okay + + align:start position:0% +electrodes glued on your scalp okay + + + align:start position:0% +electrodes glued on your scalp okay +or just stuck there with some kind of + + align:start position:0% +or just stuck there with some kind of + + + align:start position:0% +or just stuck there with some kind of +icky gel okay + + align:start position:0% +icky gel okay + + + align:start position:0% +icky gel okay +and so they're just measuring potentials + + align:start position:0% +and so they're just measuring potentials + + + align:start position:0% +and so they're just measuring potentials +and so the idea is it's neural activity + + align:start position:0% +and so the idea is it's neural activity + + + align:start position:0% +and so the idea is it's neural activity +somewhere underneath those electrodes + + align:start position:0% +somewhere underneath those electrodes + + + align:start position:0% +somewhere underneath those electrodes +but maybe like anywhere within + + align:start position:0% +but maybe like anywhere within + + + align:start position:0% +but maybe like anywhere within +you know in you know inches like along + + align:start position:0% +you know in you know inches like along + + + align:start position:0% +you know in you know inches like along +probably averages over much of the whole + + align:start position:0% +probably averages over much of the whole + + + align:start position:0% +probably averages over much of the whole +lobe underneath so it's very spatially + + align:start position:0% +lobe underneath so it's very spatially + + + align:start position:0% +lobe underneath so it's very spatially +blurry + + align:start position:0% +blurry + + + align:start position:0% +blurry +it's giving you some kind of summed idea + + align:start position:0% +it's giving you some kind of summed idea + + + align:start position:0% +it's giving you some kind of summed idea +of activity under that electrode makes + + align:start position:0% +of activity under that electrode makes + + + align:start position:0% +of activity under that electrode makes +sense electrical activity because it's + + align:start position:0% +sense electrical activity because it's + + + align:start position:0% +sense electrical activity because it's +the direct electrical consequence of + + align:start position:0% +the direct electrical consequence of + + + align:start position:0% +the direct electrical consequence of +neural activity it's very precisely time + + align:start position:0% +neural activity it's very precisely time + + + align:start position:0% +neural activity it's very precisely time +locked + + align:start position:0% +locked + + + align:start position:0% +locked +okay + + align:start position:0% +okay + + + align:start position:0% +okay +unlike functional mri which is going by + + align:start position:0% +unlike functional mri which is going by + + + align:start position:0% +unlike functional mri which is going by +way of blood flow + + align:start position:0% +way of blood flow + + + align:start position:0% +way of blood flow +okay + + align:start position:0% +okay + + + align:start position:0% +okay +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so that tells us that we have a phase + + align:start position:0% +so that tells us that we have a phase + + + align:start position:0% +so that tells us that we have a phase +specific response at 170 milliseconds + + align:start position:0% +specific response at 170 milliseconds + + + align:start position:0% +specific response at 170 milliseconds +and that's + + align:start position:0% +and that's + + + align:start position:0% +and that's +sort of more evidence that there might + + align:start position:0% +sort of more evidence that there might + + + align:start position:0% +sort of more evidence that there might +be something special in the brain for + + align:start position:0% +be something special in the brain for + + + align:start position:0% +be something special in the brain for +face recognition that's useful + + align:start position:0% +face recognition that's useful + + + align:start position:0% +face recognition that's useful +it tells us that faces are discriminated + + align:start position:0% +it tells us that faces are discriminated + + + align:start position:0% +it tells us that faces are discriminated +from non-faces + + align:start position:0% +from non-faces + + + align:start position:0% +from non-faces +they've begun to be discriminated from + + align:start position:0% +they've begun to be discriminated from + + + align:start position:0% +they've begun to be discriminated from +non-faces by 170 milliseconds after the + + align:start position:0% +non-faces by 170 milliseconds after the + + + align:start position:0% +non-faces by 170 milliseconds after the +stimulus comes on + + align:start position:0% +stimulus comes on + + + align:start position:0% +stimulus comes on +make sense + + align:start position:0% +make sense + + + align:start position:0% +make sense +okay + + align:start position:0% +okay + + + align:start position:0% +okay +now do we know whether the signal is + + align:start position:0% +now do we know whether the signal is + + + align:start position:0% +now do we know whether the signal is +coming from the fusiform face area + + align:start position:0% +coming from the fusiform face area + + + align:start position:0% +coming from the fusiform face area +no we have no idea it's like probably + + align:start position:0% +no we have no idea it's like probably + + + align:start position:0% +no we have no idea it's like probably +somewhere in the back of the head + + align:start position:0% +somewhere in the back of the head + + + align:start position:0% +somewhere in the back of the head +because you get it better with + + align:start position:0% +because you get it better with + + + align:start position:0% +because you get it better with +electrodes back here than electrodes up + + align:start position:0% +electrodes back here than electrodes up + + + align:start position:0% +electrodes back here than electrodes up +here but that's about it that's all you + + align:start position:0% +here but that's about it that's all you + + + align:start position:0% +here but that's about it that's all you +can tell + + align:start position:0% +can tell + + + align:start position:0% +can tell +um + + align:start position:0% +um + + + align:start position:0% +um +so can we do a little bit better + + align:start position:0% +so can we do a little bit better + + + align:start position:0% +so can we do a little bit better +localizing the source of that signal + + align:start position:0% +localizing the source of that signal + + + align:start position:0% +localizing the source of that signal +well maybe a hair better using a very + + align:start position:0% +well maybe a hair better using a very + + + align:start position:0% +well maybe a hair better using a very +similar method called + + align:start position:0% +similar method called + + + align:start position:0% +similar method called +magnetoencephalography + + align:start position:0% +magnetoencephalography + + + align:start position:0% +magnetoencephalography +so this is a picture that chris brewer + + align:start position:0% +so this is a picture that chris brewer + + + align:start position:0% +so this is a picture that chris brewer +took + + align:start position:0% +took + + + align:start position:0% +took +of + + align:start position:0% +of + + + align:start position:0% +of +laila ishik postdoc in my lab and me in + + align:start position:0% +laila ishik postdoc in my lab and me in + + + align:start position:0% +laila ishik postdoc in my lab and me in +the meg system this is in + + align:start position:0% +the meg system this is in + + + align:start position:0% +the meg system this is in +on the other side of the building + + align:start position:0% +on the other side of the building + + + align:start position:0% +on the other side of the building +so meg is a lot like um eeg and erps + + align:start position:0% +so meg is a lot like um eeg and erps + + + align:start position:0% +so meg is a lot like um eeg and erps +except it detects magnetic fields not + + align:start position:0% +except it detects magnetic fields not + + + align:start position:0% +except it detects magnetic fields not +electric fields okay and it does this by + + align:start position:0% +electric fields okay and it does this by + + + align:start position:0% +electric fields okay and it does this by +having these um several hundred um + + align:start position:0% +having these um several hundred um + + + align:start position:0% +having these um several hundred um +devices that are placed right next to + + align:start position:0% +devices that are placed right next to + + + align:start position:0% +devices that are placed right next to +your head in this big hairdryer thing + + align:start position:0% +your head in this big hairdryer thing + + + align:start position:0% +your head in this big hairdryer thing +there's like 300 devices in there that + + align:start position:0% +there's like 300 devices in there that + + + align:start position:0% +there's like 300 devices in there that +measure + + align:start position:0% +measure + + + align:start position:0% +measure +teeny tiny magnetic field changes that + + align:start position:0% +teeny tiny magnetic field changes that + + + align:start position:0% +teeny tiny magnetic field changes that +happen with neural activity + + align:start position:0% +happen with neural activity + + + align:start position:0% +happen with neural activity +the crux of the idea is + + align:start position:0% +the crux of the idea is + + + align:start position:0% +the crux of the idea is +this is a cross section through the + + align:start position:0% +this is a cross section through the + + + align:start position:0% +this is a cross section through the +brain so remember from uh angry bill's + + align:start position:0% +brain so remember from uh angry bill's + + + align:start position:0% +brain so remember from uh angry bill's +dissection right this is cortex here and + + align:start position:0% +dissection right this is cortex here and + + + align:start position:0% +dissection right this is cortex here and +this is underlying what is this stuff + + align:start position:0% +this is underlying what is this stuff + + + align:start position:0% +this is underlying what is this stuff +underneath underneath it + + align:start position:0% + + + + align:start position:0% + +sorry + + align:start position:0% +sorry + + + align:start position:0% +sorry +white matter yeah well those are all the + + align:start position:0% +white matter yeah well those are all the + + + align:start position:0% +white matter yeah well those are all the +fibers okay so + + align:start position:0% +fibers okay so + + + align:start position:0% +fibers okay so +the activity that underlies perception + + align:start position:0% +the activity that underlies perception + + + align:start position:0% +the activity that underlies perception +and and cognition mostly happens in the + + align:start position:0% +and and cognition mostly happens in the + + + align:start position:0% +and and cognition mostly happens in the +gray matter where the cell bodies are + + align:start position:0% +gray matter where the cell bodies are + + + align:start position:0% +gray matter where the cell bodies are +um and so a lot of that activity goes in + + align:start position:0% +um and so a lot of that activity goes in + + + align:start position:0% +um and so a lot of that activity goes in +a direction perpendicular to the + + align:start position:0% +a direction perpendicular to the + + + align:start position:0% +a direction perpendicular to the +cortical orientation with these cells + + align:start position:0% +cortical orientation with these cells + + + align:start position:0% +cortical orientation with these cells +that cross the cortical surface like + + align:start position:0% +that cross the cortical surface like + + + align:start position:0% +that cross the cortical surface like +that + + align:start position:0% +that + + + align:start position:0% +that +so if you remember 802 + + align:start position:0% +so if you remember 802 + + + align:start position:0% +so if you remember 802 +if you have activity that's going + + align:start position:0% +if you have activity that's going + + + align:start position:0% +if you have activity that's going +through the cortex like this + + align:start position:0% +through the cortex like this + + + align:start position:0% +through the cortex like this +right hand rule + + align:start position:0% +right hand rule + + + align:start position:0% +right hand rule +the magnetic field here + + align:start position:0% +the magnetic field here + + + align:start position:0% +the magnetic field here +is going to be that's a consequence of + + align:start position:0% +is going to be that's a consequence of + + + align:start position:0% +is going to be that's a consequence of +that electrical activity in this + + align:start position:0% +that electrical activity in this + + + align:start position:0% +that electrical activity in this +direction + + align:start position:0% +direction + + + align:start position:0% +direction +is going to mostly stay within the + + align:start position:0% +is going to mostly stay within the + + + align:start position:0% +is going to mostly stay within the +cortex everybody see how that's true + + align:start position:0% +cortex everybody see how that's true + + + align:start position:0% +cortex everybody see how that's true +that's not so great because our + + align:start position:0% +that's not so great because our + + + align:start position:0% +that's not so great because our +detectors are out there outside the + + align:start position:0% +detectors are out there outside the + + + align:start position:0% +detectors are out there outside the +cortex + + align:start position:0% +cortex + + + align:start position:0% +cortex +however consider the activity that's in + + align:start position:0% +however consider the activity that's in + + + align:start position:0% +however consider the activity that's in +the sulcus in here in this fold of the + + align:start position:0% +the sulcus in here in this fold of the + + + align:start position:0% +the sulcus in here in this fold of the +brain + + align:start position:0% +brain + + + align:start position:0% +brain +electrical activity in this direction + + align:start position:0% +electrical activity in this direction + + + align:start position:0% +electrical activity in this direction +right hand rule + + align:start position:0% +right hand rule + + + align:start position:0% +right hand rule +will stick outside the brain and we can + + align:start position:0% +will stick outside the brain and we can + + + align:start position:0% +will stick outside the brain and we can +detect it with our magnetic sensors does + + align:start position:0% +detect it with our magnetic sensors does + + + align:start position:0% +detect it with our magnetic sensors does +that make sense + + align:start position:0% +that make sense + + + align:start position:0% +that make sense +so you can sort of see + + align:start position:0% +so you can sort of see + + + align:start position:0% +so you can sort of see +um the most cortical activity better if + + align:start position:0% +um the most cortical activity better if + + + align:start position:0% +um the most cortical activity better if +it's in a sulcus or at least + + align:start position:0% +it's in a sulcus or at least + + + align:start position:0% +it's in a sulcus or at least +in part of the cortical surface that's + + align:start position:0% +in part of the cortical surface that's + + + align:start position:0% +in part of the cortical surface that's +perpendicular to the scalp where the + + align:start position:0% +perpendicular to the scalp where the + + + align:start position:0% +perpendicular to the scalp where the +detectors are just because of the + + align:start position:0% +detectors are just because of the + + + align:start position:0% +detectors are just because of the +orientation in the right hand rule + + align:start position:0% +orientation in the right hand rule + + + align:start position:0% +orientation in the right hand rule +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so it primarily sees + + align:start position:0% +so it primarily sees + + + align:start position:0% +so it primarily sees +activity in the in the folds or soul + + align:start position:0% +activity in the in the folds or soul + + + align:start position:0% +activity in the in the folds or soul +site not in the outer bumps or right + + align:start position:0% + + + + align:start position:0% + +field strengths are minuscule as a + + align:start position:0% +field strengths are minuscule as a + + + align:start position:0% +field strengths are minuscule as a +consequence of neural activity so the + + align:start position:0% +consequence of neural activity so the + + + align:start position:0% +consequence of neural activity so the +fields we measure are 10 to the minus + + align:start position:0% +fields we measure are 10 to the minus + + + align:start position:0% +fields we measure are 10 to the minus +13th tesla + + align:start position:0% +13th tesla + + + align:start position:0% +13th tesla +a million times weaker than the earth's + + align:start position:0% +a million times weaker than the earth's + + + align:start position:0% +a million times weaker than the earth's +magnetic field + + align:start position:0% +magnetic field + + + align:start position:0% +magnetic field +so you can imagine that if you set up an + + align:start position:0% +so you can imagine that if you set up an + + + align:start position:0% +so you can imagine that if you set up an +meg system + + align:start position:0% +meg system + + + align:start position:0% +meg system +you need a lot of shielding we had a + + align:start position:0% +you need a lot of shielding we had a + + + align:start position:0% +you need a lot of shielding we had a +whole rigmarole when the + + align:start position:0% +whole rigmarole when the + + + align:start position:0% +whole rigmarole when the +meg system was set up in this building + + align:start position:0% +meg system was set up in this building + + + align:start position:0% +meg system was set up in this building +because it's right near the um the + + align:start position:0% +because it's right near the um the + + + align:start position:0% +because it's right near the um the +subway and the train + + align:start position:0% +subway and the train + + + align:start position:0% +subway and the train +and so there are many many layers of + + align:start position:0% +and so there are many many layers of + + + align:start position:0% +and so there are many many layers of +copper shielding to protect it so we can + + align:start position:0% +copper shielding to protect it so we can + + + align:start position:0% +copper shielding to protect it so we can +detect these teeny tiny + + align:start position:0% +detect these teeny tiny + + + align:start position:0% +detect these teeny tiny +magnetic fields from the brain's + + align:start position:0% +magnetic fields from the brain's + + + align:start position:0% +magnetic fields from the brain's +activity with + + align:start position:0% +activity with + + + align:start position:0% +activity with +separated from the noise of the outside + + align:start position:0% +separated from the noise of the outside + + + align:start position:0% +separated from the noise of the outside +world which is much greater in magnitude + + align:start position:0% +world which is much greater in magnitude + + + align:start position:0% +world which is much greater in magnitude +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so um all right so actually meg was + + align:start position:0% +so um all right so actually meg was + + + align:start position:0% +so um all right so actually meg was +invented here at mit by this guy david + + align:start position:0% +invented here at mit by this guy david + + + align:start position:0% +invented here at mit by this guy david +cohen + + align:start position:0% +cohen + + + align:start position:0% +cohen +and this is the first mg device ever + + align:start position:0% +and this is the first mg device ever + + + align:start position:0% +and this is the first mg device ever +built very cool + + align:start position:0% +built very cool + + + align:start position:0% +built very cool +way back in + + align:start position:0% +way back in + + + align:start position:0% +way back in + + align:start position:0% + + + align:start position:0% +um and + + align:start position:0% +um and + + + align:start position:0% +um and +what can it tell us about face + + align:start position:0% +what can it tell us about face + + + align:start position:0% +what can it tell us about face +perception well a lot i'll give you just + + align:start position:0% +perception well a lot i'll give you just + + + align:start position:0% +perception well a lot i'll give you just +one + + align:start position:0% +one + + + align:start position:0% +one +rudimentary example + + align:start position:0% +rudimentary example + + + align:start position:0% +rudimentary example +that n170 that you can detect with scalp + + align:start position:0% +that n170 that you can detect with scalp + + + align:start position:0% +that n170 that you can detect with scalp +electrodes you can also detect with + + align:start position:0% +electrodes you can also detect with + + + align:start position:0% +electrodes you can also detect with +magnetic sensors on the head so here's + + align:start position:0% +magnetic sensors on the head so here's + + + align:start position:0% +magnetic sensors on the head so here's +some of our data from a long time ago + + align:start position:0% +some of our data from a long time ago + + + align:start position:0% +some of our data from a long time ago +this is the + + align:start position:0% +this is the + + + align:start position:0% +this is the +strength of the magnetic field at sites + + align:start position:0% +strength of the magnetic field at sites + + + align:start position:0% +strength of the magnetic field at sites +right about you know out here + + align:start position:0% +right about you know out here + + + align:start position:0% +right about you know out here +and you can see a face selective + + align:start position:0% +and you can see a face selective + + + align:start position:0% +and you can see a face selective +response also at 170 milliseconds just + + align:start position:0% +response also at 170 milliseconds just + + + align:start position:0% +response also at 170 milliseconds just +like you can + + align:start position:0% +like you can + + + align:start position:0% +like you can +uh with scalp with scalp electrodes + + align:start position:0% +uh with scalp with scalp electrodes + + + align:start position:0% +uh with scalp with scalp electrodes +um + + align:start position:0% +um + + + align:start position:0% +um +so that tells us that at least you've + + align:start position:0% +so that tells us that at least you've + + + align:start position:0% +so that tells us that at least you've +you've started to detect faces by 170 + + align:start position:0% +you've started to detect faces by 170 + + + align:start position:0% +you've started to detect faces by 170 +milliseconds that's pretty fast + + align:start position:0% + + + + align:start position:0% + +and again it's more evidence that + + align:start position:0% +and again it's more evidence that + + + align:start position:0% +and again it's more evidence that +there's specialized machinery these data + + align:start position:0% +there's specialized machinery these data + + + align:start position:0% +there's specialized machinery these data +don't yet go beyond the eeg data the erp + + align:start position:0% +don't yet go beyond the eeg data the erp + + + align:start position:0% +don't yet go beyond the eeg data the erp +data from electrical potentials + + align:start position:0% +data from electrical potentials + + + align:start position:0% +data from electrical potentials +but they might in principle and there's + + align:start position:0% +but they might in principle and there's + + + align:start position:0% +but they might in principle and there's +lots of ongoing work trying to do that + + align:start position:0% +lots of ongoing work trying to do that + + + align:start position:0% +lots of ongoing work trying to do that +okay + + align:start position:0% +okay + + + align:start position:0% +okay +overview advantages of these these + + align:start position:0% +overview advantages of these these + + + align:start position:0% +overview advantages of these these +methods both eeg and and meg they're + + align:start position:0% +methods both eeg and and meg they're + + + align:start position:0% +methods both eeg and and meg they're +non-invasive that means you don't need + + align:start position:0% +non-invasive that means you don't need + + + align:start position:0% +non-invasive that means you don't need +to open the head a very good thing + + align:start position:0% +to open the head a very good thing + + + align:start position:0% +to open the head a very good thing +especially if you're the subject + + align:start position:0% +especially if you're the subject + + + align:start position:0% +especially if you're the subject +they have very good temporal resolution + + align:start position:0% +they have very good temporal resolution + + + align:start position:0% +they have very good temporal resolution +and if we want to see computations + + align:start position:0% +and if we want to see computations + + + align:start position:0% +and if we want to see computations +unfolding over time in the brain this is + + align:start position:0% +unfolding over time in the brain this is + + + align:start position:0% +unfolding over time in the brain this is +a good way + + align:start position:0% +a good way + + + align:start position:0% +a good way +um + + align:start position:0% +um + + + align:start position:0% +um +i just said why would care about that + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so far well never mind i'm going to skip + + align:start position:0% +so far well never mind i'm going to skip + + + align:start position:0% +so far well never mind i'm going to skip +this point not that important we will + + align:start position:0% +this point not that important we will + + + align:start position:0% +this point not that important we will +get back and do more sophisticated + + align:start position:0% +get back and do more sophisticated + + + align:start position:0% +get back and do more sophisticated +things with eeg and meg and subsequent + + align:start position:0% +things with eeg and meg and subsequent + + + align:start position:0% +things with eeg and meg and subsequent +lectures + + align:start position:0% +lectures + + + align:start position:0% +lectures +disadvantages + + align:start position:0% +disadvantages + + + align:start position:0% +disadvantages +spatial resolution is terrible + + align:start position:0% +spatial resolution is terrible + + + align:start position:0% +spatial resolution is terrible +and this is another kind of ill-posed + + align:start position:0% +and this is another kind of ill-posed + + + align:start position:0% +and this is another kind of ill-posed +problem so just as the brain is facing + + align:start position:0% +problem so just as the brain is facing + + + align:start position:0% +problem so just as the brain is facing +lots of ill-posed problems in perception + + align:start position:0% +lots of ill-posed problems in perception + + + align:start position:0% +lots of ill-posed problems in perception +and cognition + + align:start position:0% +and cognition + + + align:start position:0% +and cognition +we scientists are facing ill pose + + align:start position:0% +we scientists are facing ill pose + + + align:start position:0% +we scientists are facing ill pose +problems when we collect + + align:start position:0% +problems when we collect + + + align:start position:0% +problems when we collect +electrical or magnetic activity at the + + align:start position:0% +electrical or magnetic activity at the + + + align:start position:0% +electrical or magnetic activity at the +scalp and try to infer the exact + + align:start position:0% +scalp and try to infer the exact + + + align:start position:0% +scalp and try to infer the exact +location in the brain where it's coming + + align:start position:0% +location in the brain where it's coming + + + align:start position:0% +location in the brain where it's coming +from + + align:start position:0% +from + + + align:start position:0% +from +it's a similar problem to the problem of + + align:start position:0% +it's a similar problem to the problem of + + + align:start position:0% +it's a similar problem to the problem of +invariant object recognition there are + + align:start position:0% +invariant object recognition there are + + + align:start position:0% +invariant object recognition there are +many possible configurations of sources + + align:start position:0% +many possible configurations of sources + + + align:start position:0% +many possible configurations of sources +in the brain + + align:start position:0% +in the brain + + + align:start position:0% +in the brain +that could give rise to the same set of + + align:start position:0% +that could give rise to the same set of + + + align:start position:0% +that could give rise to the same set of +electrical and magnetic fields out of + + align:start position:0% +electrical and magnetic fields out of + + + align:start position:0% +electrical and magnetic fields out of +the scalp + + align:start position:0% +the scalp + + + align:start position:0% +the scalp +and that means it's ill-posed we don't + + align:start position:0% +and that means it's ill-posed we don't + + + align:start position:0% +and that means it's ill-posed we don't +have a way to get a unique solution okay + + align:start position:0% +have a way to get a unique solution okay + + + align:start position:0% +have a way to get a unique solution okay +so all that to say + + align:start position:0% +so all that to say + + + align:start position:0% +so all that to say +we can't figure out the exact sources we + + align:start position:0% +we can't figure out the exact sources we + + + align:start position:0% +we can't figure out the exact sources we +can make some guesses that's not very + + align:start position:0% +can make some guesses that's not very + + + align:start position:0% +can make some guesses that's not very +good + + align:start position:0% +good + + + align:start position:0% +good +so what do we do just give up + + align:start position:0% +so what do we do just give up + + + align:start position:0% +so what do we do just give up +no we use another method + + align:start position:0% +no we use another method + + + align:start position:0% +no we use another method +um so here's an amazing method + + align:start position:0% +um so here's an amazing method + + + align:start position:0% +um so here's an amazing method +this is the one method in humans that + + align:start position:0% +this is the one method in humans that + + + align:start position:0% +this is the one method in humans that +gives us high resolution in both space + + align:start position:0% +gives us high resolution in both space + + + align:start position:0% +gives us high resolution in both space +and time and that's when we have the + + align:start position:0% +and time and that's when we have the + + + align:start position:0% +and time and that's when we have the +very rare opportunity to record directly + + align:start position:0% +very rare opportunity to record directly + + + align:start position:0% +very rare opportunity to record directly +from inside the human brain this happens + + align:start position:0% +from inside the human brain this happens + + + align:start position:0% +from inside the human brain this happens +only in the context of neurosurgery + + align:start position:0% +only in the context of neurosurgery + + + align:start position:0% +only in the context of neurosurgery +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so + + align:start position:0% +so + + + align:start position:0% +so +neurosurgical patients like this guy + + align:start position:0% +neurosurgical patients like this guy + + + align:start position:0% +neurosurgical patients like this guy +here we'll meet in a little bit + + align:start position:0% +here we'll meet in a little bit + + + align:start position:0% +here we'll meet in a little bit +this guy had intractable epilepsy + + align:start position:0% +this guy had intractable epilepsy + + + align:start position:0% +this guy had intractable epilepsy +and most people with epilepsy are + + align:start position:0% +and most people with epilepsy are + + + align:start position:0% +and most people with epilepsy are +treated well by drugs that suppress + + align:start position:0% +treated well by drugs that suppress + + + align:start position:0% +treated well by drugs that suppress +seizures + + align:start position:0% +seizures + + + align:start position:0% +seizures +but some people are just not responsive + + align:start position:0% +but some people are just not responsive + + + align:start position:0% +but some people are just not responsive +to drugs and if the seizures are bad + + align:start position:0% +to drugs and if the seizures are bad + + + align:start position:0% +to drugs and if the seizures are bad +enough they can be you know totally life + + align:start position:0% +enough they can be you know totally life + + + align:start position:0% +enough they can be you know totally life +disrupting if they happen + + align:start position:0% +disrupting if they happen + + + align:start position:0% +disrupting if they happen +dozens of times a day you just can't + + align:start position:0% +dozens of times a day you just can't + + + align:start position:0% +dozens of times a day you just can't +live a normal life and under those + + align:start position:0% +live a normal life and under those + + + align:start position:0% +live a normal life and under those +rather extreme circumstances + + align:start position:0% +rather extreme circumstances + + + align:start position:0% +rather extreme circumstances +sometimes the best option is + + align:start position:0% +sometimes the best option is + + + align:start position:0% +sometimes the best option is +neurosurgery that is trying to find the + + align:start position:0% +neurosurgery that is trying to find the + + + align:start position:0% +neurosurgery that is trying to find the +the source of that of those seizures and + + align:start position:0% +the source of that of those seizures and + + + align:start position:0% +the source of that of those seizures and +trying to remove it surgically + + align:start position:0% +trying to remove it surgically + + + align:start position:0% +trying to remove it surgically +okay so you hope you never have to go + + align:start position:0% +okay so you hope you never have to go + + + align:start position:0% +okay so you hope you never have to go +through this or anyone you care about + + align:start position:0% +through this or anyone you care about + + + align:start position:0% +through this or anyone you care about +has to go through it it's no picnic + + align:start position:0% +has to go through it it's no picnic + + + align:start position:0% +has to go through it it's no picnic +but actually this surgical treatment is + + align:start position:0% +but actually this surgical treatment is + + + align:start position:0% +but actually this surgical treatment is +often very effective okay + + align:start position:0% +often very effective okay + + + align:start position:0% +often very effective okay +so when neurosurgeons + + align:start position:0% +so when neurosurgeons + + + align:start position:0% +so when neurosurgeons +decide to do this they have to remove a + + align:start position:0% +decide to do this they have to remove a + + + align:start position:0% +decide to do this they have to remove a +whole piece of + + align:start position:0% +whole piece of + + + align:start position:0% +whole piece of +of skull bone to get access to the brain + + align:start position:0% +of skull bone to get access to the brain + + + align:start position:0% +of skull bone to get access to the brain +they have to go through what structure + + align:start position:0% +they have to go through what structure + + + align:start position:0% +they have to go through what structure +that ann treesman and treesman and + + align:start position:0% +that ann treesman and treesman and + + + align:start position:0% +that ann treesman and treesman and +graybill showed you in her dissection + + align:start position:0% +graybill showed you in her dissection + + + align:start position:0% +graybill showed you in her dissection +the other day + + align:start position:0% +the other day + + + align:start position:0% +the other day +what do you have to after you take off + + align:start position:0% +what do you have to after you take off + + + align:start position:0% +what do you have to after you take off +the + + align:start position:0% +the + + + align:start position:0% +the +the um + + align:start position:0% +the um + + + align:start position:0% +the um +a skull patch yes + + align:start position:0% +a skull patch yes + + + align:start position:0% +a skull patch yes +dura mater exactly that nice big piece + + align:start position:0% +dura mater exactly that nice big piece + + + align:start position:0% +dura mater exactly that nice big piece +of white leathery stuff that was sitting + + align:start position:0% +of white leathery stuff that was sitting + + + align:start position:0% +of white leathery stuff that was sitting +over the surface of the brain so you + + align:start position:0% +over the surface of the brain so you + + + align:start position:0% +over the surface of the brain so you +need to take off a skull piece of skull + + align:start position:0% +need to take off a skull piece of skull + + + align:start position:0% +need to take off a skull piece of skull +then you need to like you know cut + + align:start position:0% +then you need to like you know cut + + + align:start position:0% +then you need to like you know cut +through and push apart the dura and then + + align:start position:0% +through and push apart the dura and then + + + align:start position:0% +through and push apart the dura and then +what they sometimes do is stick + + align:start position:0% +what they sometimes do is stick + + + align:start position:0% +what they sometimes do is stick +electrodes straight on the surface of + + align:start position:0% +electrodes straight on the surface of + + + align:start position:0% +electrodes straight on the surface of +the brain + + align:start position:0% +the brain + + + align:start position:0% +the brain +okay and they do that for two reasons + + align:start position:0% +okay and they do that for two reasons + + + align:start position:0% +okay and they do that for two reasons +one + + align:start position:0% +one + + + align:start position:0% +one +if they have enough of them sampled far + + align:start position:0% +if they have enough of them sampled far + + + align:start position:0% +if they have enough of them sampled far +enough apart they can kind of + + align:start position:0% +enough apart they can kind of + + + align:start position:0% +enough apart they can kind of +triangulate and figure out where is the + + align:start position:0% +triangulate and figure out where is the + + + align:start position:0% +triangulate and figure out where is the +source of the seizure so the patient + + align:start position:0% +source of the seizure so the patient + + + align:start position:0% +source of the seizure so the patient +hangs out in the hospital for a week or + + align:start position:0% +hangs out in the hospital for a week or + + + align:start position:0% +hangs out in the hospital for a week or +so with these electrodes in their head + + align:start position:0% +so with these electrodes in their head + + + align:start position:0% +so with these electrodes in their head +waiting to have seizures and then when + + align:start position:0% +waiting to have seizures and then when + + + align:start position:0% +waiting to have seizures and then when +they have a seizure the clinicians can + + align:start position:0% +they have a seizure the clinicians can + + + align:start position:0% +they have a seizure the clinicians can +figure out where the source is so they + + align:start position:0% +figure out where the source is so they + + + align:start position:0% +figure out where the source is so they +know what bit to cut out + + align:start position:0% +know what bit to cut out + + + align:start position:0% +know what bit to cut out +okay + + align:start position:0% +okay + + + align:start position:0% +okay +the other reason to do this is to map + + align:start position:0% +the other reason to do this is to map + + + align:start position:0% +the other reason to do this is to map +functions because once the surgeons + + align:start position:0% +functions because once the surgeons + + + align:start position:0% +functions because once the surgeons +decide they have to go in and cut + + align:start position:0% +decide they have to go in and cut + + + align:start position:0% +decide they have to go in and cut +they want to try to not cut out any of + + align:start position:0% +they want to try to not cut out any of + + + align:start position:0% +they want to try to not cut out any of +the most important parts i don't know + + align:start position:0% +the most important parts i don't know + + + align:start position:0% +the most important parts i don't know +what it means to have unimportant parts + + align:start position:0% +what it means to have unimportant parts + + + align:start position:0% +what it means to have unimportant parts +of the brain but you know they try to + + align:start position:0% +of the brain but you know they try to + + + align:start position:0% +of the brain but you know they try to +they try to avoid language regions and + + align:start position:0% +they try to avoid language regions and + + + align:start position:0% +they try to avoid language regions and +stuff like that because then you know + + align:start position:0% +stuff like that because then you know + + + align:start position:0% +stuff like that because then you know +patients really notice if they lose + + align:start position:0% +patients really notice if they lose + + + align:start position:0% +patients really notice if they lose +those things + + align:start position:0% +those things + + + align:start position:0% +those things +right or motor control regions okay so + + align:start position:0% +right or motor control regions okay so + + + align:start position:0% +right or motor control regions okay so +they map out functions where they might + + align:start position:0% +they map out functions where they might + + + align:start position:0% +they map out functions where they might +be planning their route okay make sense + + align:start position:0% +be planning their route okay make sense + + + align:start position:0% +be planning their route okay make sense +now + + align:start position:0% +now + + + align:start position:0% +now +some of these patients are very kind and + + align:start position:0% +some of these patients are very kind and + + + align:start position:0% +some of these patients are very kind and +generous to the world and say + + align:start position:0% +generous to the world and say + + + align:start position:0% +generous to the world and say +yes you scientists can measure responses + + align:start position:0% +yes you scientists can measure responses + + + align:start position:0% +yes you scientists can measure responses +in my brain while i look at your damn + + align:start position:0% +in my brain while i look at your damn + + + align:start position:0% +in my brain while i look at your damn +stimuli + + align:start position:0% +stimuli + + + align:start position:0% +stimuli +and so whenever we can we ask them + + align:start position:0% +and so whenever we can we ask them + + + align:start position:0% +and so whenever we can we ask them +please please please can we show you + + align:start position:0% +please please please can we show you + + + align:start position:0% +please please please can we show you +some pictures or play you some towns or + + align:start position:0% +some pictures or play you some towns or + + + align:start position:0% +some pictures or play you some towns or +have you read some sentences while we + + align:start position:0% +have you read some sentences while we + + + align:start position:0% +have you read some sentences while we +record from your brain + + align:start position:0% +record from your brain + + + align:start position:0% +record from your brain +and some of those patients very kindly + + align:start position:0% +and some of those patients very kindly + + + align:start position:0% +and some of those patients very kindly +let us do that + + align:start position:0% +let us do that + + + align:start position:0% +let us do that +and that gives us the most amazing data + + align:start position:0% +and that gives us the most amazing data + + + align:start position:0% +and that gives us the most amazing data +you can get from human brains + + align:start position:0% +you can get from human brains + + + align:start position:0% +you can get from human brains +so for example i had a rare opportunity + + align:start position:0% +so for example i had a rare opportunity + + + align:start position:0% +so for example i had a rare opportunity +to do this a few years ago from this + + align:start position:0% +to do this a few years ago from this + + + align:start position:0% +to do this a few years ago from this +lovely guy who was undergoing + + align:start position:0% +lovely guy who was undergoing + + + align:start position:0% +lovely guy who was undergoing +neurosurgery in japan and while he had + + align:start position:0% +neurosurgery in japan and while he had + + + align:start position:0% +neurosurgery in japan and while he had +electrodes in his brain a colleague of + + align:start position:0% +electrodes in his brain a colleague of + + + align:start position:0% +electrodes in his brain a colleague of +mine was there and emailed me and said + + align:start position:0% +mine was there and emailed me and said + + + align:start position:0% +mine was there and emailed me and said +look where these electrodes are right + + align:start position:0% +look where these electrodes are right + + + align:start position:0% +look where these electrodes are right +near regions i care about do you want to + + align:start position:0% +near regions i care about do you want to + + + align:start position:0% +near regions i care about do you want to +show us some stimuli and we can we'll + + align:start position:0% +show us some stimuli and we can we'll + + + align:start position:0% +show us some stimuli and we can we'll +record responses from those electrodes + + align:start position:0% +record responses from those electrodes + + + align:start position:0% +record responses from those electrodes +and i said damn straight i want to send + + align:start position:0% +and i said damn straight i want to send + + + align:start position:0% +and i said damn straight i want to send +you some stimuli + + align:start position:0% +you some stimuli + + + align:start position:0% +you some stimuli +so my students and i stayed up for a + + align:start position:0% +so my students and i stayed up for a + + + align:start position:0% +so my students and i stayed up for a +couple days and made some stimuli and + + align:start position:0% +couple days and made some stimuli and + + + align:start position:0% +couple days and made some stimuli and +shot them to japan and got some + + align:start position:0% +shot them to japan and got some + + + align:start position:0% +shot them to japan and got some +responses from those very electrodes + + align:start position:0% + + + + align:start position:0% + +and here they are + + align:start position:0% +and here they are + + + align:start position:0% +and here they are +so this is a strip of + + align:start position:0% +so this is a strip of + + + align:start position:0% +so this is a strip of +a pair of two parallel strips of + + align:start position:0% +a pair of two parallel strips of + + + align:start position:0% +a pair of two parallel strips of +electrodes right along the fusiform + + align:start position:0% +electrodes right along the fusiform + + + align:start position:0% +electrodes right along the fusiform +gyrus right where the fusiform face area + + align:start position:0% +gyrus right where the fusiform face area + + + align:start position:0% +gyrus right where the fusiform face area +should be in most people + + align:start position:0% +should be in most people + + + align:start position:0% +should be in most people +and here are the responses of each of + + align:start position:0% +and here are the responses of each of + + + align:start position:0% +and here are the responses of each of +those electrodes like 174 is here what's + + align:start position:0% +those electrodes like 174 is here what's + + + align:start position:0% +those electrodes like 174 is here what's +173 and so forth and what you see is + + align:start position:0% +173 and so forth and what you see is + + + align:start position:0% +173 and so forth and what you see is +this batch of electrodes right here this + + align:start position:0% +this batch of electrodes right here this + + + align:start position:0% +this batch of electrodes right here this +is the response when the patient was + + align:start position:0% +is the response when the patient was + + + align:start position:0% +is the response when the patient was +looking at faces and these are the + + align:start position:0% +looking at faces and these are the + + + align:start position:0% +looking at faces and these are the +responses when they looked at a whole + + align:start position:0% +responses when they looked at a whole + + + align:start position:0% +responses when they looked at a whole +bunch of different kinds of stimuli + + align:start position:0% +bunch of different kinds of stimuli + + + align:start position:0% +bunch of different kinds of stimuli +objects and this guy's japanese so we + + align:start position:0% +objects and this guy's japanese so we + + + align:start position:0% +objects and this guy's japanese so we +showed him kana and kanji and digit + + align:start position:0% +showed him kana and kanji and digit + + + align:start position:0% +showed him kana and kanji and digit +strings and other kinds of stuff + + align:start position:0% +strings and other kinds of stuff + + + align:start position:0% +strings and other kinds of stuff +very low response to those other things + + align:start position:0% +very low response to those other things + + + align:start position:0% +very low response to those other things +this is a extremely selective response + + align:start position:0% +this is a extremely selective response + + + align:start position:0% +this is a extremely selective response +right it's much more selective than you + + align:start position:0% +right it's much more selective than you + + + align:start position:0% +right it's much more selective than you +see with functional mri because we are + + align:start position:0% +see with functional mri because we are + + + align:start position:0% +see with functional mri because we are +recording directly from the surface of + + align:start position:0% +recording directly from the surface of + + + align:start position:0% +recording directly from the surface of +the brain + + align:start position:0% +the brain + + + align:start position:0% +the brain +further we have time information this + + align:start position:0% +further we have time information this + + + align:start position:0% +further we have time information this +axis here is time and you can see that + + align:start position:0% +axis here is time and you can see that + + + align:start position:0% +axis here is time and you can see that +that response well you can't see the + + align:start position:0% +that response well you can't see the + + + align:start position:0% +that response well you can't see the +axis but that response starts up at + + align:start position:0% +axis but that response starts up at + + + align:start position:0% +axis but that response starts up at +around 130 milliseconds and peaks up + + align:start position:0% +around 130 milliseconds and peaks up + + + align:start position:0% +around 130 milliseconds and peaks up +there at around 170. everybody clear + + align:start position:0% +there at around 170. everybody clear + + + align:start position:0% +there at around 170. everybody clear +what we're seeing here + + align:start position:0% +what we're seeing here + + + align:start position:0% +what we're seeing here +and why this is so vastly better than + + align:start position:0% +and why this is so vastly better than + + + align:start position:0% +and why this is so vastly better than +either functional mri or mg or erps or + + align:start position:0% +either functional mri or mg or erps or + + + align:start position:0% +either functional mri or mg or erps or +anything else + + align:start position:0% +anything else + + + align:start position:0% +anything else +makes sense + + align:start position:0% +makes sense + + + align:start position:0% +makes sense +okay so these are very very precious + + align:start position:0% +okay so these are very very precious + + + align:start position:0% +okay so these are very very precious +data + + align:start position:0% +data + + + align:start position:0% +data +um + + align:start position:0% +um + + + align:start position:0% +um +okay + + align:start position:0% +okay + + + align:start position:0% +okay +uh + + align:start position:0% +uh + + + align:start position:0% +uh +okay + + align:start position:0% +okay + + + align:start position:0% +okay +nonetheless the electrodes in this in + + align:start position:0% +nonetheless the electrodes in this in + + + align:start position:0% +nonetheless the electrodes in this in +this case + + align:start position:0% +this case + + + align:start position:0% +this case +are about two millimeters across + + align:start position:0% +are about two millimeters across + + + align:start position:0% +are about two millimeters across +each electrode + + align:start position:0% +each electrode + + + align:start position:0% +each electrode +and that is about the size of a + + align:start position:0% +and that is about the size of a + + + align:start position:0% +and that is about the size of a +functional mri pixel or voxel + + align:start position:0% +functional mri pixel or voxel + + + align:start position:0% +functional mri pixel or voxel +okay a little bit smaller + + align:start position:0% +okay a little bit smaller + + + align:start position:0% +okay a little bit smaller +it has less blurring because functional + + align:start position:0% +it has less blurring because functional + + + align:start position:0% +it has less blurring because functional +mri blurs spatially because it's looking + + align:start position:0% +mri blurs spatially because it's looking + + + align:start position:0% +mri blurs spatially because it's looking +at blood flow so this is a more precise + + align:start position:0% +at blood flow so this is a more precise + + + align:start position:0% +at blood flow so this is a more precise +spatial measurement than functional mri + + align:start position:0% +spatial measurement than functional mri + + + align:start position:0% +spatial measurement than functional mri +but it is still averaging over probably + + align:start position:0% +but it is still averaging over probably + + + align:start position:0% +but it is still averaging over probably +tens of thousands of neurons down from + + align:start position:0% +tens of thousands of neurons down from + + + align:start position:0% +tens of thousands of neurons down from +hundreds of thousands of neurons with + + align:start position:0% +hundreds of thousands of neurons with + + + align:start position:0% +hundreds of thousands of neurons with +functional mri okay + + align:start position:0% +functional mri okay + + + align:start position:0% +functional mri okay +so can we ever get responses from + + align:start position:0% +so can we ever get responses from + + + align:start position:0% +so can we ever get responses from +individual neurons in the human brain + + align:start position:0% +individual neurons in the human brain + + + align:start position:0% +individual neurons in the human brain +yes occasionally + + align:start position:0% +yes occasionally + + + align:start position:0% +yes occasionally +in fact a paper came out on the bio + + align:start position:0% +in fact a paper came out on the bio + + + align:start position:0% +in fact a paper came out on the bio +archive a couple months ago i was on + + align:start position:0% +archive a couple months ago i was on + + + align:start position:0% +archive a couple months ago i was on +this guy's phd thesis defense and this + + align:start position:0% +this guy's phd thesis defense and this + + + align:start position:0% +this guy's phd thesis defense and this +is a guy who works with a neurosurgeon + + align:start position:0% +is a guy who works with a neurosurgeon + + + align:start position:0% +is a guy who works with a neurosurgeon +on long island and this neurosurgeon + + align:start position:0% +on long island and this neurosurgeon + + + align:start position:0% +on long island and this neurosurgeon +specializes in epilepsy + + align:start position:0% +specializes in epilepsy + + + align:start position:0% +specializes in epilepsy +neurosurgery and he's very interested in + + align:start position:0% +neurosurgery and he's very interested in + + + align:start position:0% +neurosurgery and he's very interested in +not + + align:start position:0% +not + + + align:start position:0% +not +damaging people's ability to recognize + + align:start position:0% +damaging people's ability to recognize + + + align:start position:0% +damaging people's ability to recognize +faces + + align:start position:0% +faces + + + align:start position:0% +faces +and so he sticks electrodes to map out + + align:start position:0% +and so he sticks electrodes to map out + + + align:start position:0% +and so he sticks electrodes to map out +neural activity and to discover seizure + + align:start position:0% +neural activity and to discover seizure + + + align:start position:0% +neural activity and to discover seizure +foci before the neurosurgery he sticks + + align:start position:0% +foci before the neurosurgery he sticks + + + align:start position:0% +foci before the neurosurgery he sticks +electrodes in + + align:start position:0% +electrodes in + + + align:start position:0% +electrodes in +parts of the brain near the fusiform + + align:start position:0% +parts of the brain near the fusiform + + + align:start position:0% +parts of the brain near the fusiform +face area + + align:start position:0% +face area + + + align:start position:0% +face area +so this is a slice like this through the + + align:start position:0% +so this is a slice like this through the + + + align:start position:0% +so this is a slice like this through the +brain i should do before horizontal + + align:start position:0% +brain i should do before horizontal + + + align:start position:0% +brain i should do before horizontal +slices okay so left and right are + + align:start position:0% +slices okay so left and right are + + + align:start position:0% +slices okay so left and right are +flipped that region is like you know + + align:start position:0% +flipped that region is like you know + + + align:start position:0% +flipped that region is like you know +right in there everybody oriented with + + align:start position:0% +right in there everybody oriented with + + + align:start position:0% +right in there everybody oriented with +this picture here so that this is an mri + + align:start position:0% +this picture here so that this is an mri + + + align:start position:0% +this picture here so that this is an mri +image of this person was it was scanned + + align:start position:0% +image of this person was it was scanned + + + align:start position:0% +image of this person was it was scanned +with functional mri before the + + align:start position:0% +with functional mri before the + + + align:start position:0% +with functional mri before the +electrodes were put in and that shows + + align:start position:0% +electrodes were put in and that shows + + + align:start position:0% +electrodes were put in and that shows +you their fusiform face area right there + + align:start position:0% +you their fusiform face area right there + + + align:start position:0% +you their fusiform face area right there +okay so now the neurosurgeons put in + + align:start position:0% +okay so now the neurosurgeons put in + + + align:start position:0% +okay so now the neurosurgeons put in +electrodes for clinical reasons but the + + align:start position:0% +electrodes for clinical reasons but the + + + align:start position:0% +electrodes for clinical reasons but the +electrodes this surgeon uses have these + + align:start position:0% +electrodes this surgeon uses have these + + + align:start position:0% +electrodes this surgeon uses have these +little tiny micro wires that come out of + + align:start position:0% +little tiny micro wires that come out of + + + align:start position:0% +little tiny micro wires that come out of +the tip of the electrode that enable him + + align:start position:0% +the tip of the electrode that enable him + + + align:start position:0% +the tip of the electrode that enable him +to record from individual neurons + + align:start position:0% +to record from individual neurons + + + align:start position:0% +to record from individual neurons +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and so + + align:start position:0% +and so + + + align:start position:0% +and so +these guys for the first time have + + align:start position:0% +these guys for the first time have + + + align:start position:0% +these guys for the first time have +recorded from individual neurons in the + + align:start position:0% +recorded from individual neurons in the + + + align:start position:0% +recorded from individual neurons in the +fusiform face area in humans + + align:start position:0% +fusiform face area in humans + + + align:start position:0% +fusiform face area in humans +and here's an example of one of these + + align:start position:0% +and here's an example of one of these + + + align:start position:0% +and here's an example of one of these +neurons + + align:start position:0% +neurons + + + align:start position:0% +neurons +so + + align:start position:0% +so + + + align:start position:0% +so +here different stimuli here a bunch of + + align:start position:0% +here different stimuli here a bunch of + + + align:start position:0% +here different stimuli here a bunch of +different face stimuli body stimuli + + align:start position:0% +different face stimuli body stimuli + + + align:start position:0% +different face stimuli body stimuli +houses patterns and tools + + align:start position:0% +houses patterns and tools + + + align:start position:0% +houses patterns and tools +and this shows you + + align:start position:0% +and this shows you + + + align:start position:0% +and this shows you +time across here each one of those dots + + align:start position:0% +time across here each one of those dots + + + align:start position:0% +time across here each one of those dots +is + + align:start position:0% +is + + + align:start position:0% +is +this is all the response of a single + + align:start position:0% +this is all the response of a single + + + align:start position:0% +this is all the response of a single +neuron that's been identified in a human + + align:start position:0% +neuron that's been identified in a human + + + align:start position:0% +neuron that's been identified in a human +brain + + align:start position:0% +brain + + + align:start position:0% +brain +each dot is an action potential is a + + align:start position:0% +each dot is an action potential is a + + + align:start position:0% +each dot is an action potential is a +spike out of that neuron so you can see + + align:start position:0% +spike out of that neuron so you can see + + + align:start position:0% +spike out of that neuron so you can see +them happening over time here to all the + + align:start position:0% +them happening over time here to all the + + + align:start position:0% +them happening over time here to all the +faces this is an average amount of + + align:start position:0% +faces this is an average amount of + + + align:start position:0% +faces this is an average amount of +activity to all of the faces and average + + align:start position:0% +activity to all of the faces and average + + + align:start position:0% +activity to all of the faces and average +amount of activity to all the other + + align:start position:0% +amount of activity to all the other + + + align:start position:0% +amount of activity to all the other +stimuli + + align:start position:0% +stimuli + + + align:start position:0% +stimuli +okay makes sense + + align:start position:0% +okay makes sense + + + align:start position:0% +okay makes sense +so that's pretty breathtaking to me + + align:start position:0% +so that's pretty breathtaking to me + + + align:start position:0% +so that's pretty breathtaking to me +because i've been using these very + + align:start position:0% +because i've been using these very + + + align:start position:0% +because i've been using these very +indirect methods for a long time + + align:start position:0% +indirect methods for a long time + + + align:start position:0% +indirect methods for a long time +inferring that they must result from the + + align:start position:0% +inferring that they must result from the + + + align:start position:0% +inferring that they must result from the +average across a lot of neurons doing + + align:start position:0% +average across a lot of neurons doing + + + align:start position:0% +average across a lot of neurons doing +that but it's pretty awesome to actually + + align:start position:0% +that but it's pretty awesome to actually + + + align:start position:0% +that but it's pretty awesome to actually +see individual neurons doing that + + align:start position:0% +see individual neurons doing that + + + align:start position:0% +see individual neurons doing that +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +okay + + align:start position:0% +okay + + + align:start position:0% +okay +here's the time course of responses just + + align:start position:0% +here's the time course of responses just + + + align:start position:0% +here's the time course of responses just +averaging over this raster over time + + align:start position:0% +averaging over this raster over time + + + align:start position:0% +averaging over this raster over time +showing you a similar time course to + + align:start position:0% +showing you a similar time course to + + + align:start position:0% +showing you a similar time course to +what i've shown before + + align:start position:0% +what i've shown before + + + align:start position:0% +what i've shown before +uh and in this guy's thesis he found + + align:start position:0% +uh and in this guy's thesis he found + + + align:start position:0% +uh and in this guy's thesis he found +three other + + align:start position:0% +three other + + + align:start position:0% +three other +phase selective neurons in the ffa + + align:start position:0% +phase selective neurons in the ffa + + + align:start position:0% +phase selective neurons in the ffa +but the electors are so rarely in the + + align:start position:0% +but the electors are so rarely in the + + + align:start position:0% +but the electors are so rarely in the +right location that they only have a few + + align:start position:0% +right location that they only have a few + + + align:start position:0% +right location that they only have a few +in this whole thesis and there they are + + align:start position:0% +in this whole thesis and there they are + + + align:start position:0% +in this whole thesis and there they are +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +well even if we can measure individual + + align:start position:0% +well even if we can measure individual + + + align:start position:0% +well even if we can measure individual +neurons we don't really know like which + + align:start position:0% +neurons we don't really know like which + + + align:start position:0% +neurons we don't really know like which +neuron it is right if i wanted to go + + align:start position:0% +neuron it is right if i wanted to go + + + align:start position:0% +neuron it is right if i wanted to go +back and find the same neuron again + + align:start position:0% +back and find the same neuron again + + + align:start position:0% +back and find the same neuron again +that's pretty much impossible forget it + + align:start position:0% +that's pretty much impossible forget it + + + align:start position:0% +that's pretty much impossible forget it +yep + + align:start position:0% +yep + + + align:start position:0% +yep +yep so + + align:start position:0% +yep so + + + align:start position:0% +yep so +people like me who almost never get to + + align:start position:0% +people like me who almost never get to + + + align:start position:0% +people like me who almost never get to +see responses from individual neurons + + align:start position:0% +see responses from individual neurons + + + align:start position:0% +see responses from individual neurons +and human brains have kind of neuron + + align:start position:0% +and human brains have kind of neuron + + + align:start position:0% +and human brains have kind of neuron +envy you know it's like everyone else in + + align:start position:0% +envy you know it's like everyone else in + + + align:start position:0% +envy you know it's like everyone else in +this building has they can measure stuff + + align:start position:0% +this building has they can measure stuff + + + align:start position:0% +this building has they can measure stuff +from like dendrites or ion channels or + + align:start position:0% +from like dendrites or ion channels or + + + align:start position:0% +from like dendrites or ion channels or +individual neurons they can do all this + + align:start position:0% +individual neurons they can do all this + + + align:start position:0% +individual neurons they can do all this +amazing stuff but actually there are a + + align:start position:0% +amazing stuff but actually there are a + + + align:start position:0% +amazing stuff but actually there are a +lot of limits in those limitations in + + align:start position:0% +lot of limits in those limitations in + + + align:start position:0% +lot of limits in those limitations in +those methods too and you just put your + + align:start position:0% +those methods too and you just put your + + + align:start position:0% +those methods too and you just put your +finger on one of them so there's like + + align:start position:0% +finger on one of them so there's like + + + align:start position:0% +finger on one of them so there's like +okay they found those neurons they're + + align:start position:0% +okay they found those neurons they're + + + align:start position:0% +okay they found those neurons they're +four neurons we can't go back and find + + align:start position:0% +four neurons we can't go back and find + + + align:start position:0% +four neurons we can't go back and find +those neurons again that's that right + + align:start position:0% +those neurons again that's that right + + + align:start position:0% +those neurons again that's that right +and they're probably + + align:start position:0% +and they're probably + + + align:start position:0% +and they're probably +subtly different in different brains + + align:start position:0% +subtly different in different brains + + + align:start position:0% +subtly different in different brains +right so they're it's it's cool and + + align:start position:0% +right so they're it's it's cool and + + + align:start position:0% +right so they're it's it's cool and +powerful but has still has many + + align:start position:0% +powerful but has still has many + + + align:start position:0% +powerful but has still has many +limitations + + align:start position:0% +limitations + + + align:start position:0% +limitations +okay + + align:start position:0% +okay + + + align:start position:0% +okay +um + + align:start position:0% +um + + + align:start position:0% +um +does this tell us that these neurons are + + align:start position:0% +does this tell us that these neurons are + + + align:start position:0% +does this tell us that these neurons are +involved in discriminating one face from + + align:start position:0% +involved in discriminating one face from + + + align:start position:0% +involved in discriminating one face from +another or just detecting faces can we + + align:start position:0% +another or just detecting faces can we + + + align:start position:0% +another or just detecting faces can we +tell from these data + + align:start position:0% +tell from these data + + + align:start position:0% +tell from these data +are they just saying here's a face + + align:start position:0% +are they just saying here's a face + + + align:start position:0% +are they just saying here's a face +are they saying that's joe + + align:start position:0% +are they saying that's joe + + + align:start position:0% +are they saying that's joe +did they + + align:start position:0% +did they + + + align:start position:0% +did they +have different conditions for different + + align:start position:0% +have different conditions for different + + + align:start position:0% +have different conditions for different +people + + align:start position:0% +people + + + align:start position:0% +people +these are different faces here + + align:start position:0% + + + + align:start position:0% + +what do you think what are these neurons + + align:start position:0% +what do you think what are these neurons + + + align:start position:0% +what do you think what are these neurons +doing + + align:start position:0% + + + + align:start position:0% + +yeah just right from that + + align:start position:0% +yeah just right from that + + + align:start position:0% +yeah just right from that +you can see + + align:start position:0% + + + + align:start position:0% + +you mean just detecting + + align:start position:0% +you mean just detecting + + + align:start position:0% +you mean just detecting +no just say more what do you think + + align:start position:0% +no just say more what do you think + + + align:start position:0% +no just say more what do you think +they're doing uh like they're just + + align:start position:0% +they're doing uh like they're just + + + align:start position:0% +they're doing uh like they're just +selected from faces + + align:start position:0% +selected from faces + + + align:start position:0% +selected from faces +there's no evidence to show them and + + align:start position:0% +there's no evidence to show them and + + + align:start position:0% +there's no evidence to show them and +distinguish different places + + align:start position:0% +distinguish different places + + + align:start position:0% +distinguish different places +well how about this these are different + + align:start position:0% +well how about this these are different + + + align:start position:0% +well how about this these are different +faces here + + align:start position:0% +faces here + + + align:start position:0% +faces here +these are different faces here + + align:start position:0% + + + + align:start position:0% + +was the task did the task involve them + + align:start position:0% +was the task did the task involve them + + + align:start position:0% +was the task did the task involve them +sort of acknowledging what phrases what + + align:start position:0% +sort of acknowledging what phrases what + + + align:start position:0% +sort of acknowledging what phrases what +did they have to put into their face + + align:start position:0% +did they have to put into their face + + + align:start position:0% +did they have to put into their face +nope they do they're just sitting there + + align:start position:0% +nope they do they're just sitting there + + + align:start position:0% +nope they do they're just sitting there +looking at stuff + + align:start position:0% +looking at stuff + + + align:start position:0% +looking at stuff +okay so bottom line is we don't know + + align:start position:0% +okay so bottom line is we don't know + + + align:start position:0% +okay so bottom line is we don't know +from this it could be just responding + + align:start position:0% +from this it could be just responding + + + align:start position:0% +from this it could be just responding +and saying essentially there's a face + + align:start position:0% +and saying essentially there's a face + + + align:start position:0% +and saying essentially there's a face +but the fact that there's different + + align:start position:0% +but the fact that there's different + + + align:start position:0% +but the fact that there's different +responses to different faces + + align:start position:0% +responses to different faces + + + align:start position:0% +responses to different faces +suggests that maybe there's some + + align:start position:0% +suggests that maybe there's some + + + align:start position:0% +suggests that maybe there's some +information in there + + align:start position:0% +information in there + + + align:start position:0% +information in there +like if you ran some machine learning + + align:start position:0% +like if you ran some machine learning + + + align:start position:0% +like if you ran some machine learning +code on this + + align:start position:0% +code on this + + + align:start position:0% +code on this +you could tell a little bit which face + + align:start position:0% +you could tell a little bit which face + + + align:start position:0% +you could tell a little bit which face +was being presented because those + + align:start position:0% +was being presented because those + + + align:start position:0% +was being presented because those +neurons are responding differently to + + align:start position:0% +neurons are responding differently to + + + align:start position:0% +neurons are responding differently to +different faces + + align:start position:0% +different faces + + + align:start position:0% +different faces +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +is it really like if they just show the + + align:start position:0% +is it really like if they just show the + + + align:start position:0% +is it really like if they just show the +same face repeat that you wouldn't just + + align:start position:0% +same face repeat that you wouldn't just + + + align:start position:0% +same face repeat that you wouldn't just +feel like + + align:start position:0% +feel like + + + align:start position:0% +feel like +okay very good question very good + + align:start position:0% +okay very good question very good + + + align:start position:0% +okay very good question very good +question that's why i said suggests + + align:start position:0% +question that's why i said suggests + + + align:start position:0% +question that's why i said suggests +right you're absolutely right that could + + align:start position:0% +right you're absolutely right that could + + + align:start position:0% +right you're absolutely right that could +be just noise it could be that if you + + align:start position:0% +be just noise it could be that if you + + + align:start position:0% +be just noise it could be that if you +presented the same face every time you + + align:start position:0% +presented the same face every time you + + + align:start position:0% +presented the same face every time you +get that same distribution you're + + align:start position:0% +get that same distribution you're + + + align:start position:0% +get that same distribution you're +exactly right + + align:start position:0% +exactly right + + + align:start position:0% +exactly right +and so we will talk not next time i + + align:start position:0% +and so we will talk not next time i + + + align:start position:0% +and so we will talk not next time i +think wednesday next week but anyways + + align:start position:0% +think wednesday next week but anyways + + + align:start position:0% +think wednesday next week but anyways +very soon we'll talk about methods that + + align:start position:0% +very soon we'll talk about methods that + + + align:start position:0% +very soon we'll talk about methods that +enable us to exactly deal with that + + align:start position:0% +enable us to exactly deal with that + + + align:start position:0% +enable us to exactly deal with that +question and ask is there actually + + align:start position:0% +question and ask is there actually + + + align:start position:0% +question and ask is there actually +information + + align:start position:0% +information + + + align:start position:0% +information +in this pattern of response across + + align:start position:0% +in this pattern of response across + + + align:start position:0% +in this pattern of response across +neurons or voxels or whatever it is + + align:start position:0% +neurons or voxels or whatever it is + + + align:start position:0% +neurons or voxels or whatever it is +or is that just the noise of variation + + align:start position:0% +or is that just the noise of variation + + + align:start position:0% +or is that just the noise of variation +yeah okay + + align:start position:0% +yeah okay + + + align:start position:0% +yeah okay +well how many neurons are in the + + align:start position:0% +well how many neurons are in the + + + align:start position:0% +well how many neurons are in the +epidemic + + align:start position:0% +epidemic + + + align:start position:0% +epidemic +oh good question um + + align:start position:0% +oh good question um + + + align:start position:0% +oh good question um +let's see uh + + align:start position:0% +let's see uh + + + align:start position:0% +let's see uh +i would say um + + align:start position:0% +i would say um + + + align:start position:0% +i would say um +i think a few million so let's think + + align:start position:0% +i think a few million so let's think + + + align:start position:0% +i think a few million so let's think +about it each each voxel is about um + + align:start position:0% +about it each each voxel is about um + + + align:start position:0% +about it each each voxel is about um +a half a + + align:start position:0% +a half a + + + align:start position:0% +a half a +half a million and they're typically + + align:start position:0% +half a million and they're typically + + + align:start position:0% +half a million and they're typically +maybe like + + align:start position:0% +maybe like + + + align:start position:0% +maybe like +30 voxels something like that somewhere + + align:start position:0% +30 voxels something like that somewhere + + + align:start position:0% +30 voxels something like that somewhere +on the order of 20 million something + + align:start position:0% +on the order of 20 million something + + + align:start position:0% +on the order of 20 million something +like that i mean with huge error bars + + align:start position:0% +like that i mean with huge error bars + + + align:start position:0% +like that i mean with huge error bars +okay + + align:start position:0% +okay + + + align:start position:0% +okay +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so um + + align:start position:0% +so um + + + align:start position:0% +so um +this is cool and tantalizing but it + + align:start position:0% +this is cool and tantalizing but it + + + align:start position:0% +this is cool and tantalizing but it +doesn't even tell us what these neurons + + align:start position:0% +doesn't even tell us what these neurons + + + align:start position:0% +doesn't even tell us what these neurons +what exactly they're participating in it + + align:start position:0% +what exactly they're participating in it + + + align:start position:0% +what exactly they're participating in it +doesn't tell us if those neurons are + + align:start position:0% +doesn't tell us if those neurons are + + + align:start position:0% +doesn't tell us if those neurons are +telling that person which face is there + + align:start position:0% +telling that person which face is there + + + align:start position:0% +telling that person which face is there +or maybe what facial expression the + + align:start position:0% +or maybe what facial expression the + + + align:start position:0% +or maybe what facial expression the +person has or how old they are or + + align:start position:0% +person has or how old they are or + + + align:start position:0% +person has or how old they are or +whether they're male or female or god + + align:start position:0% +whether they're male or female or god + + + align:start position:0% +whether they're male or female or god +knows what else right + + align:start position:0% +knows what else right + + + align:start position:0% +knows what else right +and it certainly doesn't tell us how + + align:start position:0% +and it certainly doesn't tell us how + + + align:start position:0% +and it certainly doesn't tell us how +those neurons get that information okay + + align:start position:0% +those neurons get that information okay + + + align:start position:0% +those neurons get that information okay +still it's cool + + align:start position:0% +still it's cool + + + align:start position:0% +still it's cool +okay so intracranial recording + + align:start position:0% +okay so intracranial recording + + + align:start position:0% +okay so intracranial recording +both with the um the grids that i showed + + align:start position:0% +both with the um the grids that i showed + + + align:start position:0% +both with the um the grids that i showed +you and the single unit version + + align:start position:0% +you and the single unit version + + + align:start position:0% +you and the single unit version +advantages are this is the only method + + align:start position:0% +advantages are this is the only method + + + align:start position:0% +advantages are this is the only method +in humans that has both pretty good + + align:start position:0% +in humans that has both pretty good + + + align:start position:0% +in humans that has both pretty good +spatial resolution and temporal + + align:start position:0% +spatial resolution and temporal + + + align:start position:0% +spatial resolution and temporal +resolution at the same time + + align:start position:0% +resolution at the same time + + + align:start position:0% +resolution at the same time +um disadvantage well you need to have a + + align:start position:0% +um disadvantage well you need to have a + + + align:start position:0% +um disadvantage well you need to have a +craniotomy which is no picnic to put it + + align:start position:0% +craniotomy which is no picnic to put it + + + align:start position:0% +craniotomy which is no picnic to put it +mildly you need to have a huge piece of + + align:start position:0% +mildly you need to have a huge piece of + + + align:start position:0% +mildly you need to have a huge piece of +your skull removed and + + align:start position:0% +your skull removed and + + + align:start position:0% +your skull removed and +neurosurgery and that means that the + + align:start position:0% +neurosurgery and that means that the + + + align:start position:0% +neurosurgery and that means that the +only times we get to do this are when + + align:start position:0% +only times we get to do this are when + + + align:start position:0% +only times we get to do this are when +it's required clinically + + align:start position:0% +it's required clinically + + + align:start position:0% +it's required clinically +and everything is under control of the + + align:start position:0% +and everything is under control of the + + + align:start position:0% +and everything is under control of the +doctors as it should be right so the + + align:start position:0% +doctors as it should be right so the + + + align:start position:0% +doctors as it should be right so the +doctors make all the choices about where + + align:start position:0% +doctors make all the choices about where + + + align:start position:0% +doctors make all the choices about where +the electrodes go + + align:start position:0% +the electrodes go + + + align:start position:0% +the electrodes go +and we just get to sit in the background + + align:start position:0% +and we just get to sit in the background + + + align:start position:0% +and we just get to sit in the background +and say please please please look at + + align:start position:0% +and say please please please look at + + + align:start position:0% +and say please please please look at +these stimuli + + align:start position:0% +these stimuli + + + align:start position:0% +these stimuli +but try not to hassle the patients too + + align:start position:0% +but try not to hassle the patients too + + + align:start position:0% +but try not to hassle the patients too +much + + align:start position:0% +much + + + align:start position:0% +much +right now there's a patient in albany + + align:start position:0% +right now there's a patient in albany + + + align:start position:0% +right now there's a patient in albany +new york who has electrodes right over a + + align:start position:0% +new york who has electrodes right over a + + + align:start position:0% +new york who has electrodes right over a +really exciting part of the brain to us + + align:start position:0% +really exciting part of the brain to us + + + align:start position:0% +really exciting part of the brain to us +that i'll talk about in a few months + + align:start position:0% +that i'll talk about in a few months + + + align:start position:0% +that i'll talk about in a few months +this patient has electrodes that respond + + align:start position:0% +this patient has electrodes that respond + + + align:start position:0% +this patient has electrodes that respond +specifically to music we will talk about + + align:start position:0% +specifically to music we will talk about + + + align:start position:0% +specifically to music we will talk about +that later it's pretty amazing + + align:start position:0% +that later it's pretty amazing + + + align:start position:0% +that later it's pretty amazing +and for the last couple days dana and i + + align:start position:0% +and for the last couple days dana and i + + + align:start position:0% +and for the last couple days dana and i +have been mostly dana has been + + align:start position:0% +have been mostly dana has been + + + align:start position:0% +have been mostly dana has been +collecting stimuli because we really + + align:start position:0% +collecting stimuli because we really + + + align:start position:0% +collecting stimuli because we really +want to ask questions about the response + + align:start position:0% +want to ask questions about the response + + + align:start position:0% +want to ask questions about the response +of those electrodes and this patient is + + align:start position:0% +of those electrodes and this patient is + + + align:start position:0% +of those electrodes and this patient is +not too thrilled listening to our + + align:start position:0% +not too thrilled listening to our + + + align:start position:0% +not too thrilled listening to our +stimuli so we finally said oh you okay + + align:start position:0% +stimuli so we finally said oh you okay + + + align:start position:0% +stimuli so we finally said oh you okay +you can watch tell the patient they can + + align:start position:0% +you can watch tell the patient they can + + + align:start position:0% +you can watch tell the patient they can +just do instagram on their phone and + + align:start position:0% +just do instagram on their phone and + + + align:start position:0% +just do instagram on their phone and +we'll play the stimuli in the background + + align:start position:0% +we'll play the stimuli in the background + + + align:start position:0% +we'll play the stimuli in the background +so + + align:start position:0% +so + + + align:start position:0% +so +hopefully we'll have cool data from that + + align:start position:0% +hopefully we'll have cool data from that + + + align:start position:0% +hopefully we'll have cool data from that +soon + + align:start position:0% +soon + + + align:start position:0% +soon +okay so to say that these data are + + align:start position:0% +okay so to say that these data are + + + align:start position:0% +okay so to say that these data are +limited and hard to control is an + + align:start position:0% +limited and hard to control is an + + + align:start position:0% +limited and hard to control is an +understatement like we basically can't + + align:start position:0% +understatement like we basically can't + + + align:start position:0% +understatement like we basically can't +control it at all all we can control + + align:start position:0% +control it at all all we can control + + + align:start position:0% +control it at all all we can control +occasionally is the stimuli + + align:start position:0% +occasionally is the stimuli + + + align:start position:0% +occasionally is the stimuli +and + + align:start position:0% +and + + + align:start position:0% +and +and it also like functional mri just + + align:start position:0% +and it also like functional mri just + + + align:start position:0% +and it also like functional mri just +because we see those beautiful responses + + align:start position:0% +because we see those beautiful responses + + + align:start position:0% +because we see those beautiful responses +it doesn't tell us + + align:start position:0% +it doesn't tell us + + + align:start position:0% +it doesn't tell us +how how those responses are connected to + + align:start position:0% +how how those responses are connected to + + + align:start position:0% +how how those responses are connected to +behavior + + align:start position:0% +behavior + + + align:start position:0% +behavior +right + + align:start position:0% +right + + + align:start position:0% +right +so that's a that's a real challenge + + align:start position:0% +so that's a that's a real challenge + + + align:start position:0% +so that's a that's a real challenge +so that won't do + + align:start position:0% +so that won't do + + + align:start position:0% +so that won't do +uh we need to get beyond this problem i + + align:start position:0% +uh we need to get beyond this problem i + + + align:start position:0% +uh we need to get beyond this problem i +keep saying this method is great but it + + align:start position:0% +keep saying this method is great but it + + + align:start position:0% +keep saying this method is great but it +doesn't tell us the causal role of that + + align:start position:0% +doesn't tell us the causal role of that + + + align:start position:0% +doesn't tell us the causal role of that +neural phenomenon in in cognition and + + align:start position:0% +neural phenomenon in in cognition and + + + align:start position:0% +neural phenomenon in in cognition and +behavior as scientists science is all + + align:start position:0% +behavior as scientists science is all + + + align:start position:0% +behavior as scientists science is all +about discovering causal mechanisms + + align:start position:0% +about discovering causal mechanisms + + + align:start position:0% +about discovering causal mechanisms +right we're not just interested in what + + align:start position:0% +right we're not just interested in what + + + align:start position:0% +right we're not just interested in what +is correlated with what we want to know + + align:start position:0% +is correlated with what we want to know + + + align:start position:0% +is correlated with what we want to know +what's causing what that's really of the + + align:start position:0% +what's causing what that's really of the + + + align:start position:0% +what's causing what that's really of the +essence and so we need to do better here + + align:start position:0% +essence and so we need to do better here + + + align:start position:0% +essence and so we need to do better here +uh so what are we gonna do somebody + + align:start position:0% +uh so what are we gonna do somebody + + + align:start position:0% +uh so what are we gonna do somebody +mentioned a while ago maybe it was + + align:start position:0% +mentioned a while ago maybe it was + + + align:start position:0% +mentioned a while ago maybe it was +isabelle that one of the ways to do that + + align:start position:0% +isabelle that one of the ways to do that + + + align:start position:0% +isabelle that one of the ways to do that +and ask whether the face area is + + align:start position:0% +and ask whether the face area is + + + align:start position:0% +and ask whether the face area is +causally involved in face perception + + align:start position:0% +causally involved in face perception + + + align:start position:0% +causally involved in face perception +is to look at a case where the face area + + align:start position:0% +is to look at a case where the face area + + + align:start position:0% +is to look at a case where the face area +is altered okay so there's a bunch of + + align:start position:0% +is altered okay so there's a bunch of + + + align:start position:0% +is altered okay so there's a bunch of +ways to do that + + align:start position:0% +ways to do that + + + align:start position:0% +ways to do that +and one of them + + align:start position:0% +and one of them + + + align:start position:0% +and one of them +okay that's just a review we said faces + + align:start position:0% +okay that's just a review we said faces + + + align:start position:0% +okay that's just a review we said faces +are recognized fast but we haven't + + align:start position:0% +are recognized fast but we haven't + + + align:start position:0% +are recognized fast but we haven't +learned much more + + align:start position:0% +learned much more + + + align:start position:0% +learned much more +how do we + + align:start position:0% +how do we + + + align:start position:0% +how do we +test causality okay patients with vocal + + align:start position:0% +test causality okay patients with vocal + + + align:start position:0% +test causality okay patients with vocal +brain damage + + align:start position:0% +brain damage + + + align:start position:0% +brain damage +here is a patient these are vertical + + align:start position:0% +here is a patient these are vertical + + + align:start position:0% +here is a patient these are vertical +slices through the back back of this + + align:start position:0% +slices through the back back of this + + + align:start position:0% +slices through the back back of this +patient's head okay let me get oriented + + align:start position:0% +patient's head okay let me get oriented + + + align:start position:0% +patient's head okay let me get oriented +this slice is maybe like this here and + + align:start position:0% +this slice is maybe like this here and + + + align:start position:0% +this slice is maybe like this here and +as you go rightward you're marching back + + align:start position:0% +as you go rightward you're marching back + + + align:start position:0% +as you go rightward you're marching back +in the brain like that everybody + + align:start position:0% +in the brain like that everybody + + + align:start position:0% +in the brain like that everybody +oriented + + align:start position:0% +oriented + + + align:start position:0% +oriented +what's this thing right there + + align:start position:0% + + + + align:start position:0% + +yeah cerebellum right + + align:start position:0% +yeah cerebellum right + + + align:start position:0% +yeah cerebellum right +that thing right there is this patient's + + align:start position:0% +that thing right there is this patient's + + + align:start position:0% +that thing right there is this patient's +lesion that spans several slices going + + align:start position:0% +lesion that spans several slices going + + + align:start position:0% +lesion that spans several slices going +back like that + + align:start position:0% +back like that + + + align:start position:0% +back like that +and this patient's lesion + + align:start position:0% +and this patient's lesion + + + align:start position:0% +and this patient's lesion +looks a whole lot like my ffa there's my + + align:start position:0% +looks a whole lot like my ffa there's my + + + align:start position:0% +looks a whole lot like my ffa there's my +ffa + + align:start position:0% +ffa + + + align:start position:0% +ffa +greater response to faces and objects on + + align:start position:0% +greater response to faces and objects on + + + align:start position:0% +greater response to faces and objects on +similar slices + + align:start position:0% +similar slices + + + align:start position:0% +similar slices +we don't have functional mri from this + + align:start position:0% +we don't have functional mri from this + + + align:start position:0% +we don't have functional mri from this +patient so we don't know exactly where + + align:start position:0% +patient so we don't know exactly where + + + align:start position:0% +patient so we don't know exactly where +this guy's ffa was but there's a good + + align:start position:0% +this guy's ffa was but there's a good + + + align:start position:0% +this guy's ffa was but there's a good +bet that it was blitzed by that lesion + + align:start position:0% +bet that it was blitzed by that lesion + + + align:start position:0% +bet that it was blitzed by that lesion +okay because it's right in the zone + + align:start position:0% +okay because it's right in the zone + + + align:start position:0% +okay because it's right in the zone +where it usually lands + + align:start position:0% +where it usually lands + + + align:start position:0% +where it usually lands +and this patient + + align:start position:0% +and this patient + + + align:start position:0% +and this patient +can't recognize faces at all + + align:start position:0% +can't recognize faces at all + + + align:start position:0% +can't recognize faces at all +and importantly + + align:start position:0% +and importantly + + + align:start position:0% +and importantly +patient is absolutely normal at + + align:start position:0% +patient is absolutely normal at + + + align:start position:0% +patient is absolutely normal at +recognizing objects + + align:start position:0% +recognizing objects + + + align:start position:0% +recognizing objects +no problem whatsoever at recognizing + + align:start position:0% +no problem whatsoever at recognizing + + + align:start position:0% +no problem whatsoever at recognizing +objects + + align:start position:0% +objects + + + align:start position:0% +objects +okay + + align:start position:0% +okay + + + align:start position:0% +okay +how does this take us beyond functional + + align:start position:0% +how does this take us beyond functional + + + align:start position:0% +how does this take us beyond functional +mri + + align:start position:0% + + + + align:start position:0% + +speak up + + align:start position:0% +speak up + + + align:start position:0% +speak up +yeah say more what what is it what does + + align:start position:0% +yeah say more what what is it what does + + + align:start position:0% +yeah say more what what is it what does +it tell us so because the because of the + + align:start position:0% +it tell us so because the because of the + + + align:start position:0% +it tell us so because the because of the +fact that like that theory is damaged + + align:start position:0% +fact that like that theory is damaged + + + align:start position:0% +fact that like that theory is damaged +and then + + align:start position:0% +and then + + + align:start position:0% +and then +it makes it to like not being recognized + + align:start position:0% +it makes it to like not being recognized + + + align:start position:0% +it makes it to like not being recognized +because i could see how there's + + align:start position:0% +because i could see how there's + + + align:start position:0% +because i could see how there's +something to do with that period exactly + + align:start position:0% +something to do with that period exactly + + + align:start position:0% +something to do with that period exactly +exactly it says you need that bit to + + align:start position:0% +exactly it says you need that bit to + + + align:start position:0% +exactly it says you need that bit to +recognize faces but also says something + + align:start position:0% +recognize faces but also says something + + + align:start position:0% +recognize faces but also says something +else + + align:start position:0% +else + + + align:start position:0% +else +what else does it + + align:start position:0% + + + + align:start position:0% + +you don't need it for recognizing + + align:start position:0% +you don't need it for recognizing + + + align:start position:0% +you don't need it for recognizing +objects so this is actually really + + align:start position:0% +objects so this is actually really + + + align:start position:0% +objects so this is actually really +strong evidence that that bit of brain + + align:start position:0% +strong evidence that that bit of brain + + + align:start position:0% +strong evidence that that bit of brain +is + + align:start position:0% +is + + + align:start position:0% +is +very specialized for face recognition + + align:start position:0% +very specialized for face recognition + + + align:start position:0% +very specialized for face recognition +specialized and necessary for face + + align:start position:0% +specialized and necessary for face + + + align:start position:0% +specialized and necessary for face +recognition + + align:start position:0% +recognition + + + align:start position:0% +recognition +okay + + align:start position:0% +okay + + + align:start position:0% +okay +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so um + + align:start position:0% + + + + align:start position:0% + +so person still attacked faces + + align:start position:0% +so person still attacked faces + + + align:start position:0% +so person still attacked faces +oh yes good question absolutely like + + align:start position:0% +oh yes good question absolutely like + + + align:start position:0% +oh yes good question absolutely like +okay so let me just distinguish this + + align:start position:0% +okay so let me just distinguish this + + + align:start position:0% +okay so let me just distinguish this +person here + + align:start position:0% +person here + + + align:start position:0% +person here +um who has prosopagnosia that means a + + align:start position:0% +um who has prosopagnosia that means a + + + align:start position:0% +um who has prosopagnosia that means a +selective deficit and face recognition + + align:start position:0% +selective deficit and face recognition + + + align:start position:0% +selective deficit and face recognition +like jacob hodes who i described + + align:start position:0% +like jacob hodes who i described + + + align:start position:0% +like jacob hodes who i described +yesterday who has no brain damage + + align:start position:0% +yesterday who has no brain damage + + + align:start position:0% +yesterday who has no brain damage +whatsoever but has just never been able + + align:start position:0% +whatsoever but has just never been able + + + align:start position:0% +whatsoever but has just never been able +to recognize faces at any point in his + + align:start position:0% +to recognize faces at any point in his + + + align:start position:0% +to recognize faces at any point in his +life + + align:start position:0% +life + + + align:start position:0% +life +so this syndrome can arise just from + + align:start position:0% +so this syndrome can arise just from + + + align:start position:0% +so this syndrome can arise just from +some weird developmental thing where + + align:start position:0% +some weird developmental thing where + + + align:start position:0% +some weird developmental thing where +you're atypical and you're just really + + align:start position:0% +you're atypical and you're just really + + + align:start position:0% +you're atypical and you're just really +bad at it or it can result from damage + + align:start position:0% +bad at it or it can result from damage + + + align:start position:0% +bad at it or it can result from damage +to that part of the brain okay so now + + align:start position:0% +to that part of the brain okay so now + + + align:start position:0% +to that part of the brain okay so now +we're talking about the case of damage + + align:start position:0% +we're talking about the case of damage + + + align:start position:0% +we're talking about the case of damage +but in both cases + + align:start position:0% +but in both cases + + + align:start position:0% +but in both cases +people with prosopagnosia have no + + align:start position:0% +people with prosopagnosia have no + + + align:start position:0% +people with prosopagnosia have no +problem knowing that a face is a face + + align:start position:0% +problem knowing that a face is a face + + + align:start position:0% +problem knowing that a face is a face +they just don't know who it is + + align:start position:0% +they just don't know who it is + + + align:start position:0% +they just don't know who it is +okay + + align:start position:0% +okay + + + align:start position:0% +okay +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +has there ever been a case + + align:start position:0% + + + + align:start position:0% + +of people who can't recognize spaces who + + align:start position:0% +of people who can't recognize spaces who + + + align:start position:0% +of people who can't recognize spaces who +um + + align:start position:0% + + + + align:start position:0% + +indeed + + align:start position:0% +indeed + + + align:start position:0% +indeed +indeed jacob hodes who i talked about + + align:start position:0% +indeed jacob hodes who i talked about + + + align:start position:0% +indeed jacob hodes who i talked about +last time who is just absolutely awful + + align:start position:0% +last time who is just absolutely awful + + + align:start position:0% +last time who is just absolutely awful +at face recognition including family + + align:start position:0% +at face recognition including family + + + align:start position:0% +at face recognition including family +members close friends can't do it like + + align:start position:0% +members close friends can't do it like + + + align:start position:0% +members close friends can't do it like +not at all + + align:start position:0% +not at all + + + align:start position:0% +not at all +he has a very normal looking fusiform + + align:start position:0% +he has a very normal looking fusiform + + + align:start position:0% +he has a very normal looking fusiform +face area + + align:start position:0% +face area + + + align:start position:0% +face area +so after i told you that i had that + + align:start position:0% +so after i told you that i had that + + + align:start position:0% +so after i told you that i had that +conversation with him + + align:start position:0% +conversation with him + + + align:start position:0% +conversation with him +a dozen years ago or something like that + + align:start position:0% +a dozen years ago or something like that + + + align:start position:0% +a dozen years ago or something like that +i scanned him + + align:start position:0% +i scanned him + + + align:start position:0% +i scanned him +and he had a beautiful fusiform face + + align:start position:0% +and he had a beautiful fusiform face + + + align:start position:0% +and he had a beautiful fusiform face +area like textbook it looked + + align:start position:0% +area like textbook it looked + + + align:start position:0% +area like textbook it looked +well looked like mine which is a damn + + align:start position:0% +well looked like mine which is a damn + + + align:start position:0% +well looked like mine which is a damn +fine one if i if i do say so myself + + align:start position:0% +fine one if i if i do say so myself + + + align:start position:0% +fine one if i if i do say so myself +um and um + + align:start position:0% +um and um + + + align:start position:0% +um and um +i looked at that and i went oh + + align:start position:0% +i looked at that and i went oh + + + align:start position:0% +i looked at that and i went oh +i better publish this before someone + + align:start position:0% +i better publish this before someone + + + align:start position:0% +i better publish this before someone +else does and i didn't get my act + + align:start position:0% +else does and i didn't get my act + + + align:start position:0% +else does and i didn't get my act +together and then a whole bunch of + + align:start position:0% +together and then a whole bunch of + + + align:start position:0% +together and then a whole bunch of +papers came out saying oh people with + + align:start position:0% +papers came out saying oh people with + + + align:start position:0% +papers came out saying oh people with +developmental prosopagnosia have normal + + align:start position:0% +developmental prosopagnosia have normal + + + align:start position:0% +developmental prosopagnosia have normal +looking face areas take that canvasser + + align:start position:0% +looking face areas take that canvasser + + + align:start position:0% +looking face areas take that canvasser +what do you say about that + + align:start position:0% + + + + align:start position:0% + +and it was a little shocking + + align:start position:0% +and it was a little shocking + + + align:start position:0% +and it was a little shocking +but upon further reflection it's not + + align:start position:0% +but upon further reflection it's not + + + align:start position:0% +but upon further reflection it's not +really devastating right i mean it's + + align:start position:0% +really devastating right i mean it's + + + align:start position:0% +really devastating right i mean it's +bracing it's informative + + align:start position:0% +bracing it's informative + + + align:start position:0% +bracing it's informative +but it tells you + + align:start position:0% +but it tells you + + + align:start position:0% +but it tells you +that having a face area that is a region + + align:start position:0% +that having a face area that is a region + + + align:start position:0% +that having a face area that is a region +that responds more to faces and objects + + align:start position:0% +that responds more to faces and objects + + + align:start position:0% +that responds more to faces and objects +isn't sufficient + + align:start position:0% +isn't sufficient + + + align:start position:0% +isn't sufficient +for normal face recognition + + align:start position:0% +for normal face recognition + + + align:start position:0% +for normal face recognition +right you need other stuff + + align:start position:0% +right you need other stuff + + + align:start position:0% +right you need other stuff +what might that other stuff be well the + + align:start position:0% +what might that other stuff be well the + + + align:start position:0% +what might that other stuff be well the +circuits in there need to work right + + align:start position:0% +circuits in there need to work right + + + align:start position:0% +circuits in there need to work right +it's not enough to just respond more to + + align:start position:0% +it's not enough to just respond more to + + + align:start position:0% +it's not enough to just respond more to +faces and objects to recognize faces + + align:start position:0% +faces and objects to recognize faces + + + align:start position:0% +faces and objects to recognize faces +they need to be able to distinguish + + align:start position:0% +they need to be able to distinguish + + + align:start position:0% +they need to be able to distinguish +faces from objects we don't know if + + align:start position:0% +faces from objects we don't know if + + + align:start position:0% +faces from objects we don't know if +that's working right + + align:start position:0% +that's working right + + + align:start position:0% +that's working right +what else do you need + + align:start position:0% +what else do you need + + + align:start position:0% +what else do you need +memory absolutely + + align:start position:0% +memory absolutely + + + align:start position:0% +memory absolutely +yes you need to remember faces what else + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +could be but in jacob's case it was like + + align:start position:0% +could be but in jacob's case it was like + + + align:start position:0% +could be but in jacob's case it was like +close friends he couldn't recognize + + align:start position:0% +close friends he couldn't recognize + + + align:start position:0% +close friends he couldn't recognize +so what's another possible account of + + align:start position:0% +so what's another possible account of + + + align:start position:0% +so what's another possible account of +how could he have a normal face area and + + align:start position:0% +how could he have a normal face area and + + + align:start position:0% +how could he have a normal face area and +yeah david it might be a + + align:start position:0% +yeah david it might be a + + + align:start position:0% +yeah david it might be a +gap between + + align:start position:0% +gap between + + + align:start position:0% +gap between +recognizing on face and connecting that + + align:start position:0% +recognizing on face and connecting that + + + align:start position:0% +recognizing on face and connecting that +to recognizing a person + + align:start position:0% +to recognizing a person + + + align:start position:0% +to recognizing a person +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +yeah or to put that neuroanatomically + + align:start position:0% +yeah or to put that neuroanatomically + + + align:start position:0% +yeah or to put that neuroanatomically +you got to get the information out of + + align:start position:0% +you got to get the information out of + + + align:start position:0% +you got to get the information out of +there + + align:start position:0% +there + + + align:start position:0% +there +like maybe for all we know + + align:start position:0% +like maybe for all we know + + + align:start position:0% +like maybe for all we know +that little face area is working + + align:start position:0% +that little face area is working + + + align:start position:0% +that little face area is working +perfectly maybe that face area knows who + + align:start position:0% +perfectly maybe that face area knows who + + + align:start position:0% +perfectly maybe that face area knows who +that person is in a sense + + align:start position:0% +that person is in a sense + + + align:start position:0% +that person is in a sense +but if the connections out of that brain + + align:start position:0% +but if the connections out of that brain + + + align:start position:0% +but if the connections out of that brain +region to the rest of the brain + + align:start position:0% +region to the rest of the brain + + + align:start position:0% +region to the rest of the brain +are messed up it doesn't do you any good + + align:start position:0% +are messed up it doesn't do you any good + + + align:start position:0% +are messed up it doesn't do you any good +right you need to be able to read that + + align:start position:0% +right you need to be able to read that + + + align:start position:0% +right you need to be able to read that +information out and act on the basis of + + align:start position:0% +information out and act on the basis of + + + align:start position:0% +information out and act on the basis of +it right + + align:start position:0% +it right + + + align:start position:0% +it right +anyway that's a big sidebar + + align:start position:0% +anyway that's a big sidebar + + + align:start position:0% +anyway that's a big sidebar +point is you can have prosopagnosia + + align:start position:0% +point is you can have prosopagnosia + + + align:start position:0% +point is you can have prosopagnosia +either as just a developmental disorder + + align:start position:0% +either as just a developmental disorder + + + align:start position:0% +either as just a developmental disorder +or as a result of brain damage oh god i + + align:start position:0% +or as a result of brain damage oh god i + + + align:start position:0% +or as a result of brain damage oh god i +knew that was going to happen all right + + align:start position:0% +knew that was going to happen all right + + + align:start position:0% +knew that was going to happen all right +um + + align:start position:0% +um + + + align:start position:0% +um +so okay so very briefly um it s it + + align:start position:0% +so okay so very briefly um it s it + + + align:start position:0% +so okay so very briefly um it s it +messes up ability to discriminate and + + align:start position:0% +messes up ability to discriminate and + + + align:start position:0% +messes up ability to discriminate and +recognize faces not your ability to + + align:start position:0% +recognize faces not your ability to + + + align:start position:0% +recognize faces not your ability to +detect a face right so spurted ass it's + + align:start position:0% +detect a face right so spurted ass it's + + + align:start position:0% +detect a face right so spurted ass it's +not just you can't uh tell the thing as + + align:start position:0% +not just you can't uh tell the thing as + + + align:start position:0% +not just you can't uh tell the thing as +a face they're fine with that + + align:start position:0% +a face they're fine with that + + + align:start position:0% +a face they're fine with that +importantly they're normal at voice + + align:start position:0% +importantly they're normal at voice + + + align:start position:0% +importantly they're normal at voice +recognition okay so it's not that + + align:start position:0% +recognition okay so it's not that + + + align:start position:0% +recognition okay so it's not that +they're confused about distinguishing + + align:start position:0% +they're confused about distinguishing + + + align:start position:0% +they're confused about distinguishing +one person from another they can do it + + align:start position:0% +one person from another they can do it + + + align:start position:0% +one person from another they can do it +fine + + align:start position:0% +fine + + + align:start position:0% +fine +from audition just not from vision + + align:start position:0% +from audition just not from vision + + + align:start position:0% +from audition just not from vision +um when the in the rare cases where the + + align:start position:0% +um when the in the rare cases where the + + + align:start position:0% +um when the in the rare cases where the +lesion is small it can be very specific + + align:start position:0% +lesion is small it can be very specific + + + align:start position:0% +lesion is small it can be very specific +leaving object recognition intact more + + align:start position:0% +leaving object recognition intact more + + + align:start position:0% +leaving object recognition intact more +often there's kind of a blurry mess you + + align:start position:0% +often there's kind of a blurry mess you + + + align:start position:0% +often there's kind of a blurry mess you +have a big lesion and a bunch of things + + align:start position:0% +have a big lesion and a bunch of things + + + align:start position:0% +have a big lesion and a bunch of things +are affected + + align:start position:0% +are affected + + + align:start position:0% +are affected +okay so we've talked about that okay now + + align:start position:0% +okay so we've talked about that okay now + + + align:start position:0% +okay so we've talked about that okay now +it's very important in neuropsychology + + align:start position:0% +it's very important in neuropsychology + + + align:start position:0% +it's very important in neuropsychology +reasoning like we want to say okay + + align:start position:0% +reasoning like we want to say okay + + + align:start position:0% +reasoning like we want to say okay +that's really powerful the case of + + align:start position:0% +that's really powerful the case of + + + align:start position:0% +that's really powerful the case of +prosopagnosia you lose that bit you + + align:start position:0% +prosopagnosia you lose that bit you + + + align:start position:0% +prosopagnosia you lose that bit you +can't recognize faces + + align:start position:0% +can't recognize faces + + + align:start position:0% +can't recognize faces +um + + align:start position:0% +um + + + align:start position:0% +um +and and that that establishes a kind of + + align:start position:0% +and and that that establishes a kind of + + + align:start position:0% +and and that that establishes a kind of +causality that we didn't have before + + align:start position:0% +causality that we didn't have before + + + align:start position:0% +causality that we didn't have before +okay with just functional mri + + align:start position:0% +okay with just functional mri + + + align:start position:0% +okay with just functional mri +but is that sufficient to say that that + + align:start position:0% +but is that sufficient to say that that + + + align:start position:0% +but is that sufficient to say that that +region is specialized for face + + align:start position:0% +region is specialized for face + + + align:start position:0% +region is specialized for face +recognition only + + align:start position:0% + + + + align:start position:0% + +it's not whenever i ask this the answer + + align:start position:0% +it's not whenever i ask this the answer + + + align:start position:0% +it's not whenever i ask this the answer +is no your task is to say why + + align:start position:0% +is no your task is to say why + + + align:start position:0% +is no your task is to say why +how could you have + + align:start position:0% +how could you have + + + align:start position:0% +how could you have +great difficulty recognizing faces and + + align:start position:0% +great difficulty recognizing faces and + + + align:start position:0% +great difficulty recognizing faces and +be okay at object recognition and yet + + align:start position:0% +be okay at object recognition and yet + + + align:start position:0% +be okay at object recognition and yet +not have a deficit that's specific to + + align:start position:0% +not have a deficit that's specific to + + + align:start position:0% +not have a deficit that's specific to +faces + + align:start position:0% +faces + + + align:start position:0% +faces +what what are how how might that arise + + align:start position:0% +what what are how how might that arise + + + align:start position:0% +what what are how how might that arise +you guys have suggested this hypothesis + + align:start position:0% +you guys have suggested this hypothesis + + + align:start position:0% +you guys have suggested this hypothesis +in different contexts before + + align:start position:0% + + + + align:start position:0% + +yes you look like you know + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% +um + + + align:start position:0% +um +sort of um but the question here is + + align:start position:0% +sort of um but the question here is + + + align:start position:0% +sort of um but the question here is +how if you if you + + align:start position:0% +how if you if you + + + align:start position:0% +how if you if you +okay let's just start bare bones you + + align:start position:0% +okay let's just start bare bones you + + + align:start position:0% +okay let's just start bare bones you +have a lesion + + align:start position:0% +have a lesion + + + align:start position:0% +have a lesion +you get around fine in the world you can + + align:start position:0% +you get around fine in the world you can + + + align:start position:0% +you get around fine in the world you can +do everything else but you have a real + + align:start position:0% +do everything else but you have a real + + + align:start position:0% +do everything else but you have a real +problem recognizing faces + + align:start position:0% +problem recognizing faces + + + align:start position:0% +problem recognizing faces +does that mean that the region lesioned + + align:start position:0% +does that mean that the region lesioned + + + align:start position:0% +does that mean that the region lesioned +is necessary for face recognition per se + + align:start position:0% +is necessary for face recognition per se + + + align:start position:0% +is necessary for face recognition per se +there might be + + align:start position:0% +there might be + + + align:start position:0% +there might be +like other ancients + + align:start position:0% +like other ancients + + + align:start position:0% +like other ancients +right + + align:start position:0% +right + + + align:start position:0% +right +that's true there could be other things + + align:start position:0% +that's true there could be other things + + + align:start position:0% +that's true there could be other things +going on absolutely but let's suppose + + align:start position:0% +going on absolutely but let's suppose + + + align:start position:0% +going on absolutely but let's suppose +they're not let's suppose you had good + + align:start position:0% +they're not let's suppose you had good + + + align:start position:0% +they're not let's suppose you had good +reason to think there weren't yeah it + + align:start position:0% +reason to think there weren't yeah it + + + align:start position:0% +reason to think there weren't yeah it +could be like uh + + align:start position:0% +could be like uh + + + align:start position:0% +could be like uh +like could be a path it could be like + + align:start position:0% +like could be a path it could be like + + + align:start position:0% +like could be a path it could be like +one point in a pathway that's true it + + align:start position:0% +one point in a pathway that's true it + + + align:start position:0% +one point in a pathway that's true it +could be totally a point in a pathway + + align:start position:0% +could be totally a point in a pathway + + + align:start position:0% +could be totally a point in a pathway +absolutely that's another account what + + align:start position:0% +absolutely that's another account what + + + align:start position:0% +absolutely that's another account what +else + + align:start position:0% +else + + + align:start position:0% +else +oh i i couldn't give lots of comments he + + align:start position:0% +oh i i couldn't give lots of comments he + + + align:start position:0% +oh i i couldn't give lots of comments he +said like maybe you damage a pathway + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +maybe there's some other function we + + align:start position:0% +maybe there's some other function we + + + align:start position:0% +maybe there's some other function we +haven't tested + + align:start position:0% +haven't tested + + + align:start position:0% +haven't tested +let's all these are very good + + align:start position:0% +let's all these are very good + + + align:start position:0% +let's all these are very good +alternative hypotheses you guys are very + + align:start position:0% +alternative hypotheses you guys are very + + + align:start position:0% +alternative hypotheses you guys are very +good at this the one i'm fishing for is + + align:start position:0% +good at this the one i'm fishing for is + + + align:start position:0% +good at this the one i'm fishing for is +maybe face recognition is just harder + + align:start position:0% +maybe face recognition is just harder + + + align:start position:0% +maybe face recognition is just harder +than object recognition + + align:start position:0% +than object recognition + + + align:start position:0% +than object recognition +maybe the part that's damaged is just + + align:start position:0% +maybe the part that's damaged is just + + + align:start position:0% +maybe the part that's damaged is just +generically involved in object + + align:start position:0% +generically involved in object + + + align:start position:0% +generically involved in object +recognition + + align:start position:0% +recognition + + + align:start position:0% +recognition +but you damage part of the object + + align:start position:0% +but you damage part of the object + + + align:start position:0% +but you damage part of the object +recognition system and face recognition + + align:start position:0% +recognition system and face recognition + + + align:start position:0% +recognition system and face recognition +takes a bigger hit because it's harder + + align:start position:0% +takes a bigger hit because it's harder + + + align:start position:0% +takes a bigger hit because it's harder +right does that make sense + + align:start position:0% +right does that make sense + + + align:start position:0% +right does that make sense +do you see how the case of prosopagnosia + + align:start position:0% +do you see how the case of prosopagnosia + + + align:start position:0% +do you see how the case of prosopagnosia +is consistent with that so that means we + + align:start position:0% +is consistent with that so that means we + + + align:start position:0% +is consistent with that so that means we +cannot infer from these data alone that + + align:start position:0% +cannot infer from these data alone that + + + align:start position:0% +cannot infer from these data alone that +that region is specialized for face + + align:start position:0% +that region is specialized for face + + + align:start position:0% +that region is specialized for face +recognition + + align:start position:0% +recognition + + + align:start position:0% +recognition +now we can do various things like test + + align:start position:0% +now we can do various things like test + + + align:start position:0% +now we can do various things like test +them on really hard versions of object + + align:start position:0% +them on really hard versions of object + + + align:start position:0% +them on really hard versions of object +recognition and people have done that + + align:start position:0% +recognition and people have done that + + + align:start position:0% +recognition and people have done that +but there's another kind of data that + + align:start position:0% +but there's another kind of data that + + + align:start position:0% +but there's another kind of data that +are really powerful here + + align:start position:0% +are really powerful here + + + align:start position:0% +are really powerful here +and that's when we have the opposite + + align:start position:0% +and that's when we have the opposite + + + align:start position:0% +and that's when we have the opposite +syndrome + + align:start position:0% +syndrome + + + align:start position:0% +syndrome +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so there's a only a couple cases of this + + align:start position:0% +so there's a only a couple cases of this + + + align:start position:0% +so there's a only a couple cases of this +the best one is called ck published in a + + align:start position:0% +the best one is called ck published in a + + + align:start position:0% +the best one is called ck published in a +paper in 1997. you don't need to + + align:start position:0% +paper in 1997. you don't need to + + + align:start position:0% +paper in 1997. you don't need to +remember that the point about this is + + align:start position:0% +remember that the point about this is + + + align:start position:0% +remember that the point about this is +that this guy has the opposite syndrome + + align:start position:0% +that this guy has the opposite syndrome + + + align:start position:0% +that this guy has the opposite syndrome +he's severely impaired at object + + align:start position:0% +he's severely impaired at object + + + align:start position:0% +he's severely impaired at object +recognition he can't tell a chair from a + + align:start position:0% +recognition he can't tell a chair from a + + + align:start position:0% +recognition he can't tell a chair from a +table from a car from a toaster + + align:start position:0% +table from a car from a toaster + + + align:start position:0% +table from a car from a toaster +but he's a hundred percent normal at + + align:start position:0% +but he's a hundred percent normal at + + + align:start position:0% +but he's a hundred percent normal at +face recognition + + align:start position:0% +face recognition + + + align:start position:0% +face recognition +totally normal at face recognition in + + align:start position:0% +totally normal at face recognition in + + + align:start position:0% +totally normal at face recognition in +fact better than average + + align:start position:0% + + + + align:start position:0% + +do you see how that's in some ways even + + align:start position:0% +do you see how that's in some ways even + + + align:start position:0% +do you see how that's in some ways even +more powerful evidence + + align:start position:0% +more powerful evidence + + + align:start position:0% +more powerful evidence +that face recognition goes on in + + align:start position:0% +that face recognition goes on in + + + align:start position:0% +that face recognition goes on in +specialized brain machinery than the + + align:start position:0% +specialized brain machinery than the + + + align:start position:0% +specialized brain machinery than the +case of prostagnosia + + align:start position:0% +case of prostagnosia + + + align:start position:0% +case of prostagnosia +like face recognition isn't even like a + + align:start position:0% +like face recognition isn't even like a + + + align:start position:0% +like face recognition isn't even like a +special thing that sits on top of normal + + align:start position:0% +special thing that sits on top of normal + + + align:start position:0% +special thing that sits on top of normal +object recognition it's a totally + + align:start position:0% +object recognition it's a totally + + + align:start position:0% +object recognition it's a totally +different pathway you can have no + + align:start position:0% +different pathway you can have no + + + align:start position:0% +different pathway you can have no +ability to recognize objects and you're + + align:start position:0% +ability to recognize objects and you're + + + align:start position:0% +ability to recognize objects and you're +okay at face recognition does everybody + + align:start position:0% +okay at face recognition does everybody + + + align:start position:0% +okay at face recognition does everybody +see how that's really powerful + + align:start position:0% +see how that's really powerful + + + align:start position:0% +see how that's really powerful +and how those two kinds of evidence + + align:start position:0% +and how those two kinds of evidence + + + align:start position:0% +and how those two kinds of evidence +together are vastly more powerful than + + align:start position:0% +together are vastly more powerful than + + + align:start position:0% +together are vastly more powerful than +either one alone okay + + align:start position:0% +either one alone okay + + + align:start position:0% +either one alone okay +well that's called a doubled association + + align:start position:0% +well that's called a doubled association + + + align:start position:0% +well that's called a doubled association +um we'll skip all of that for now double + + align:start position:0% +um we'll skip all of that for now double + + + align:start position:0% +um we'll skip all of that for now double +dissociations are particularly powerful + + align:start position:0% +dissociations are particularly powerful + + + align:start position:0% +dissociations are particularly powerful +examples uh powerful forms of evidence + + align:start position:0% +examples uh powerful forms of evidence + + + align:start position:0% +examples uh powerful forms of evidence +in cognitive neuroscience where we have + + align:start position:0% +in cognitive neuroscience where we have + + + align:start position:0% +in cognitive neuroscience where we have +opposite syndromes that collectively + + align:start position:0% +opposite syndromes that collectively + + + align:start position:0% +opposite syndromes that collectively +make it really hard to wiggle out and + + align:start position:0% +make it really hard to wiggle out and + + + align:start position:0% +make it really hard to wiggle out and +come up with alternative accounts other + + align:start position:0% +come up with alternative accounts other + + + align:start position:0% +come up with alternative accounts other +than that + + align:start position:0% +than that + + + align:start position:0% +than that +there's a there's a bit of brain that's + + align:start position:0% +there's a there's a bit of brain that's + + + align:start position:0% +there's a there's a bit of brain that's +really specialized for face recognition + + align:start position:0% +really specialized for face recognition + + + align:start position:0% +really specialized for face recognition +it's not just that face recognition is + + align:start position:0% +it's not just that face recognition is + + + align:start position:0% +it's not just that face recognition is +harder or else you'd never get this + + align:start position:0% +harder or else you'd never get this + + + align:start position:0% +harder or else you'd never get this +syndrome + + align:start position:0% +syndrome + + + align:start position:0% +syndrome +okay + + align:start position:0% +okay + + + align:start position:0% +okay +all right i just wanted to finish that + + align:start position:0% +all right i just wanted to finish that + + + align:start position:0% +all right i just wanted to finish that +point okay now how much time do i have + + align:start position:0% +point okay now how much time do i have + + + align:start position:0% +point okay now how much time do i have +until the quiz + + align:start position:0% + + + + align:start position:0% + +50 minutes okay good um okay good we're + + align:start position:0% +50 minutes okay good um okay good we're + + + align:start position:0% +50 minutes okay good um okay good we're +going to skip over tms i'm sorry about + + align:start position:0% +going to skip over tms i'm sorry about + + + align:start position:0% +going to skip over tms i'm sorry about +that guys someday i'll learn to time + + align:start position:0% +that guys someday i'll learn to time + + + align:start position:0% +that guys someday i'll learn to time +things in a lecture actually i knew this + + align:start position:0% +things in a lecture actually i knew this + + + align:start position:0% +things in a lecture actually i knew this +was going to happen just + + align:start position:0% +was going to happen just + + + align:start position:0% +was going to happen just +we'll get back to tms later + + align:start position:0% +we'll get back to tms later + + + align:start position:0% +we'll get back to tms later +and we will skip to + + align:start position:0% +and we will skip to + + + align:start position:0% +and we will skip to +the most amazing method in all of + + align:start position:0% +the most amazing method in all of + + + align:start position:0% +the most amazing method in all of +cognitive neuroscience + + align:start position:0% +cognitive neuroscience + + + align:start position:0% +cognitive neuroscience +for which we're going to come back to + + align:start position:0% +for which we're going to come back to + + + align:start position:0% +for which we're going to come back to +this dude who you met before who has the + + align:start position:0% +this dude who you met before who has the + + + align:start position:0% +this dude who you met before who has the +face selective responses in that part of + + align:start position:0% +face selective responses in that part of + + + align:start position:0% +face selective responses in that part of +his brain + + align:start position:0% +his brain + + + align:start position:0% +his brain +okay remember how i said that even + + align:start position:0% +okay remember how i said that even + + + align:start position:0% +okay remember how i said that even +though these data are gorgeous and + + align:start position:0% +though these data are gorgeous and + + + align:start position:0% +though these data are gorgeous and +spectacular and the only way we can get + + align:start position:0% +spectacular and the only way we can get + + + align:start position:0% +spectacular and the only way we can get +high spatial and temporal resolution + + align:start position:0% +high spatial and temporal resolution + + + align:start position:0% +high spatial and temporal resolution +together but they don't tell us + + align:start position:0% +together but they don't tell us + + + align:start position:0% +together but they don't tell us +causality + + align:start position:0% +causality + + + align:start position:0% +causality +right that's true here + + align:start position:0% +right that's true here + + + align:start position:0% +right that's true here +resolution doesn't get you causality to + + align:start position:0% +resolution doesn't get you causality to + + + align:start position:0% +resolution doesn't get you causality to +test the causal role of something you + + align:start position:0% +test the causal role of something you + + + align:start position:0% +test the causal role of something you +need to mess with it + + align:start position:0% +need to mess with it + + + align:start position:0% +need to mess with it +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so it turns out that sometimes the + + align:start position:0% +so it turns out that sometimes the + + + align:start position:0% +so it turns out that sometimes the +neurosurgeons electrically stimulate + + align:start position:0% +neurosurgeons electrically stimulate + + + align:start position:0% +neurosurgeons electrically stimulate +through those same electrodes + + align:start position:0% +through those same electrodes + + + align:start position:0% +through those same electrodes +and they do that to test the function of + + align:start position:0% +and they do that to test the function of + + + align:start position:0% +and they do that to test the function of +those regions causally + + align:start position:0% +those regions causally + + + align:start position:0% +those regions causally +they also do it to test their hypotheses + + align:start position:0% +they also do it to test their hypotheses + + + align:start position:0% +they also do it to test their hypotheses +about the location of the seizure foci + + align:start position:0% +about the location of the seizure foci + + + align:start position:0% +about the location of the seizure foci +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so in those rare cases where you have a + + align:start position:0% +so in those rare cases where you have a + + + align:start position:0% +so in those rare cases where you have a +patient like this with selective + + align:start position:0% +patient like this with selective + + + align:start position:0% +patient like this with selective +electrodes like that + + align:start position:0% +electrodes like that + + + align:start position:0% +electrodes like that +where the clinicians decide that they + + align:start position:0% +where the clinicians decide that they + + + align:start position:0% +where the clinicians decide that they +are going to electrically stimulate + + align:start position:0% +are going to electrically stimulate + + + align:start position:0% +are going to electrically stimulate +through some of those electrodes then + + align:start position:0% +through some of those electrodes then + + + align:start position:0% +through some of those electrodes then +we're in a position to kind of have it + + align:start position:0% +we're in a position to kind of have it + + + align:start position:0% +we're in a position to kind of have it +all scientifically right i don't mean to + + align:start position:0% +all scientifically right i don't mean to + + + align:start position:0% +all scientifically right i don't mean to +be so crude this is a horrible situation + + align:start position:0% +be so crude this is a horrible situation + + + align:start position:0% +be so crude this is a horrible situation +for that lovely guy to be in but + + align:start position:0% +for that lovely guy to be in but + + + align:start position:0% +for that lovely guy to be in but +scientifically it's extremely powerful + + align:start position:0% +scientifically it's extremely powerful + + + align:start position:0% +scientifically it's extremely powerful +so + + align:start position:0% +so + + + align:start position:0% +so +i'm going to show you um we did in fact + + align:start position:0% +i'm going to show you um we did in fact + + + align:start position:0% +i'm going to show you um we did in fact +have an opportunity the same guys in + + align:start position:0% +have an opportunity the same guys in + + + align:start position:0% +have an opportunity the same guys in +japan + + align:start position:0% +japan + + + align:start position:0% +japan +emailed me and said okay we're going to + + align:start position:0% +emailed me and said okay we're going to + + + align:start position:0% +emailed me and said okay we're going to +be stimulating that electrode + + align:start position:0% +be stimulating that electrode + + + align:start position:0% +be stimulating that electrode +what do we do + + align:start position:0% +what do we do + + + align:start position:0% +what do we do +and i said okay have him look at faces + + align:start position:0% +and i said okay have him look at faces + + + align:start position:0% +and i said okay have him look at faces +and have him look at other objects and + + align:start position:0% +and have him look at other objects and + + + align:start position:0% +and have him look at other objects and +ask him if anything changes and i'm + + align:start position:0% +ask him if anything changes and i'm + + + align:start position:0% +ask him if anything changes and i'm +going to show you a video of what + + align:start position:0% +going to show you a video of what + + + align:start position:0% +going to show you a video of what +happens when that goes on + + align:start position:0% +happens when that goes on + + + align:start position:0% +happens when that goes on +okay there we go + + align:start position:0% + + + + align:start position:0% + +oh and i need to turn on the audio + + align:start position:0% + + + + align:start position:0% + +okay here this is getting stimulated + + align:start position:0% +okay here this is getting stimulated + + + align:start position:0% +okay here this is getting stimulated +right there and he says + + align:start position:0% + + + + align:start position:0% + +he's such a good subject this guy + + align:start position:0% + + + + align:start position:0% + +okay that tells us that that region is + + align:start position:0% +okay that tells us that that region is + + + align:start position:0% +okay that tells us that that region is +causally involved in face perception is + + align:start position:0% +causally involved in face perception is + + + align:start position:0% +causally involved in face perception is +it causally involved in perception of + + align:start position:0% +it causally involved in perception of + + + align:start position:0% +it causally involved in perception of +things that aren't faces he's getting + + align:start position:0% +things that aren't faces he's getting + + + align:start position:0% +things that aren't faces he's getting +stimulated in the same electrode he + + align:start position:0% +stimulated in the same electrode he + + + align:start position:0% +stimulated in the same electrode he +doesn't know that there's a face area + + align:start position:0% +doesn't know that there's a face area + + + align:start position:0% +doesn't know that there's a face area +he doesn't know what which electrode is + + align:start position:0% +he doesn't know what which electrode is + + + align:start position:0% +he doesn't know what which electrode is +being stimulated + + align:start position:0% + + + + align:start position:0% + +this is a kanji character on a card here + + align:start position:0% + + + + align:start position:0% + +one more time + + align:start position:0% + + + + align:start position:0% + +awesome huh what did we just learn + + align:start position:0% + + + + align:start position:0% + +you can trigger it yeah + + align:start position:0% +you can trigger it yeah + + + align:start position:0% +you can trigger it yeah +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +so what does that tell us about the + + align:start position:0% +so what does that tell us about the + + + align:start position:0% +so what does that tell us about the +function of that region + + align:start position:0% + + + + align:start position:0% + +why is this i mean it's amazing to see + + align:start position:0% +why is this i mean it's amazing to see + + + align:start position:0% +why is this i mean it's amazing to see +no question but what does it tell us + + align:start position:0% +no question but what does it tell us + + + align:start position:0% +no question but what does it tell us +scientifically + + align:start position:0% +scientifically + + + align:start position:0% +scientifically +specific + + align:start position:0% +specific + + + align:start position:0% +specific +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +how does it tell us that it's specific + + align:start position:0% +how does it tell us that it's specific + + + align:start position:0% +how does it tell us that it's specific +because when you stimulate it like + + align:start position:0% +because when you stimulate it like + + + align:start position:0% +because when you stimulate it like +it particularly sees a face + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +and what happens when he's looking at + + align:start position:0% +and what happens when he's looking at + + + align:start position:0% +and what happens when he's looking at +things that aren't faces + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +so you know if that region was causally + + align:start position:0% +so you know if that region was causally + + + align:start position:0% +so you know if that region was causally +involved in perception of things that + + align:start position:0% +involved in perception of things that + + + align:start position:0% +involved in perception of things that +aren't faces + + align:start position:0% +aren't faces + + + align:start position:0% +aren't faces +you might think that um that it would + + align:start position:0% +you might think that um that it would + + + align:start position:0% +you might think that um that it would +distort the box would look different or + + align:start position:0% +distort the box would look different or + + + align:start position:0% +distort the box would look different or +the ball would look different or the + + align:start position:0% +the ball would look different or the + + + align:start position:0% +the ball would look different or the +kanji would look different it doesn't + + align:start position:0% +kanji would look different it doesn't + + + align:start position:0% +kanji would look different it doesn't +there's just a face on top + + align:start position:0% +there's just a face on top + + + align:start position:0% +there's just a face on top +so i think that's very strong evidence + + align:start position:0% +so i think that's very strong evidence + + + align:start position:0% +so i think that's very strong evidence +that that region is not only causally + + align:start position:0% +that that region is not only causally + + + align:start position:0% +that that region is not only causally +involved in face perception + + align:start position:0% +involved in face perception + + + align:start position:0% +involved in face perception +but very specifically causally involved + + align:start position:0% +but very specifically causally involved + + + align:start position:0% +but very specifically causally involved +in face perception only anybody get that + + align:start position:0% +in face perception only anybody get that + + + align:start position:0% +in face perception only anybody get that +do i have to stop + + align:start position:0% +do i have to stop + + + align:start position:0% +do i have to stop +okay + + align:start position:0% +okay + + + align:start position:0% +okay +um okay i have another video consider + + align:start position:0% +um okay i have another video consider + + + align:start position:0% +um okay i have another video consider +and we'll get back to this later + + align:start position:0% +and we'll get back to this later + + + align:start position:0% +and we'll get back to this later +consider + + align:start position:0% +consider + + + align:start position:0% +consider +um + + align:start position:0% +um + + + align:start position:0% +um +other alternative hypotheses to this + + align:start position:0% +other alternative hypotheses to this + + + align:start position:0% +other alternative hypotheses to this +this is this is pretty powerful like + + align:start position:0% +this is this is pretty powerful like + + + align:start position:0% +this is this is pretty powerful like +this is more powerful than most of the + + align:start position:0% +this is more powerful than most of the + + + align:start position:0% +this is more powerful than most of the +other things i showed you but there's + + align:start position:0% +other things i showed you but there's + + + align:start position:0% +other things i showed you but there's +always ways to come up with alternative + + align:start position:0% +always ways to come up with alternative + + + align:start position:0% +always ways to come up with alternative +hypotheses and that's the business we're + + align:start position:0% +hypotheses and that's the business we're + + + align:start position:0% +hypotheses and that's the business we're +in here so be percolating on what other + + align:start position:0% +in here so be percolating on what other + + + align:start position:0% +in here so be percolating on what other +control conditions you'd want from this + + align:start position:0% +control conditions you'd want from this + + + align:start position:0% +control conditions you'd want from this +guy + + align:start position:0% +guy + + + align:start position:0% +guy +to really believe these data \ No newline at end of file diff --git a/YEZUywtDJQ4.txt b/YEZUywtDJQ4.txt new file mode 100644 index 0000000000000000000000000000000000000000..912d487692e707c8b8b3bc56d0d7084cd46bfcad --- /dev/null +++ b/YEZUywtDJQ4.txt @@ -0,0 +1,608 @@ +In order to understand how procedures are +implemented on the beta, we will take a look + +at a mystery function and its translation +into beta assembly code. + +The mystery function is shown here: +The function f takes an argument x as an input. + +It then performs a logical AND operation on +the input x and the constant 5 to produce + +the variable a. +After that, it checks if the input x is equal + +to 0, and if so returns the value 0, otherwise +it returns an unknown value which we need + +to determine. +We are provided with the translation of this + +C code into beta assembly as shown here. +We take a closer look at the various parts + +of this code to understand how this function +as well as procedures in general work on the + +beta. +The code that calls the procedure is responsible + +for pushing any arguments onto the stack. +This is shown in pink in the code and on the + +stack. +If there are multiple arguments then they + +are pushed in reverse order so that the first +argument is always in the same location relative + +to the BP, or base pointer, register which +we will see in a moment. + +The BR instruction branches to label f after +storing the return address, which is b, into + +the LP, or linkage pointer, register. +In yellow, we see the entry sequence for the + +procedure. +The structure of this entry sequence is identical + +for all procedures. +The first thing it does is PUSH(LP) which + +pushes the LP register onto the stack immediately +after the arguments that were pushed onto + +the stack by the caller. +Next it pushes the BP onto the stack in order + +to save the most recent value of the BP register +before updating it. + +Now, a MOVE(SP, BP) is performed. +SP is the stack pointer which always points + +to the next empty location on the stack. +At the time that this MOVE operation is executed, + +the SP, points to the location immediately +following the saved BP. + +This move instruction makes the BP point to +the same location that the SP is currently + +pointing to, which is the location that is +immediately following the saved BP. + +Note, that once the BP register is set up, +one can always find the first argument at + +location BP – 12 (or in other words, 3 words +before the current BP register). + +If there was a second argument, it could be +found in location BP – 16, and so on. + +Next, we allocate space on the stack for any +local variables. + +This procedure allocates space for one local +variable. + +Finally, we push all registers that are going +to be modified by our procedure onto the stack. + +Doing this makes it possible to recover the +registers' original values once the procedure + +completes execution. +In this example, register R1 is saved onto + +the stack. +Once the entry sequence is complete, the BP + +register still points to the location immediately +following the saved BP. + +The SP, however, now points to the location +immediately following the saved R1 register. + +So for this procedure, after executing the +entry sequence, the stack has been modified + +as shown here. +The procedure return, or exit, sequence for + +all beta procedures follows the same structure. +It is assumed that the return value for the + +procedure has already been placed into register +R0. + +Next, all registers that were used in the +procedure body, are restored to their original + +values. +This is followed by deallocating all of the + +local variables from the stack. +We then restore the BP, followed by the LP + +register. +Finally, we jump to LP which contains the + +return address of our procedure. +In this case, LP contains the address b which + +is the address of the next instruction that +should be executed following the execution + +of the f procedure. +Taking a closer look at the details for our + +example, we see that we begin our exit sequence +with POP(R1) in order to restore the original + +value of register R1. +Note that this also frees up the location + +on the stack that was used to store the value +of R1. + +Next, we get rid of the local variables we +stored on the stack. + +This is achieved using the MOVE(BP, SP) instruction +which makes the SP point to the same location + +as the BP thus specifying that all the locations +following the updated SP are now considered + +unused. +Next, we restore the BP register. + +Restoring the BP register is particularly +important for nested procedure calls. + +If we did not restore the BP register, then +upon return to the calling procedure, the + +calling procedure would no longer have a correct +BP, so it would not be able to rely on the + +fact that it's first argument is located at +location BP-12, for example. + +Finally, we restore the LP register and JMP +to the location of the restored LP register. + +This is the return address, so by jumping +to LP, we return from our procedure call and + +are now ready to execute the next instruction +at label b. + +Now let's get back to our original procedure +and its translation to beta assembly. + +We will now try to understand what this mystery +function is actually doing by examining the + +remaining sections of our assembly code highlighted +here. + +Let's zoom into the highlighted code. +The LD instruction loads the first argument + +into register R0. +Recall that the first argument can always + +be found at location BP – 12, or in other +words, 3 words before the current BP register. + +This means that the value x is loaded into +R0. + +Next we perform a binary AND operation between +R0 and the constant 5, and store the result + +of that operation into register R1. +Note that its okay to overwrite R1 because + +the entry sequence already saved a copy of +the original R1 onto the stack. + +Also, note that overwriting R0 is considered +fine because we ultimately expect the result + +to be returned in R0, so there is no expectation +of maintaining the original value of R0. + +Looking back at the c code of our function, +we see that the bitwise AND of x and 5 is + +stored into a local variable named a. +In our entry sequence, we allocated 1 word + +on the stack for our local variables. +That is where we want to store this intermediate + +result. +The address of this location is equal to the + +contents of the BP register. +Since the destination of a store operation + +is determined by adding the contents of the +last register in the instruction to the constant, + +the destination of this store operation is +the value of BP + 0. + +So as expected, variable a is stored at the +location pointed to by the BP register. + +Now we check if x equals 0 and if so we want +to return the value 0. + +This is achieved in beta assembly by checking +if R0 is equal to 0 since R0 was loaded with + +the value of x by the LD operation. +The BEQ operation checks whether or not this + +condition holds and if so, it branches to +label bye which is our exit sequence. + +In that situation, we just saw that R0 = 0, +so R0 already contains the correct return + +value and we are ready to execute our return +sequence. + +If x is not equal to 0, then we perform the +instructions after label xx. + +By figuring out what these instructions do, +we can identify the value of our mystery function + +labeled ?????. +We begin by decrementing R0 by 1. + +This means that R0 will be updated to hold +x-1. + +We then push this value onto the stack and +make a recursive call to procedure f. + +In other words, we call f again with a new +argument which is equal to x-1. + +So far we know that our mystery function will +contain the term f(x-1). + +We also see that LP gets updated with the +new return address which is yy + 4. + +So just before our recursive call to f with +the new argument x-1, our stack looks like + +this. +After the procedure entry sequence is executed + +in the first recursive call, our stack looks +like this. + +Note that this time the saved LP is yy + 4 +because that is our return address for the + +recursive procedure call. +The previous BP points to where the BP was + +pointing to in the original call to f. +Another term for this group of stack elements + +is the activation record. +In this example, each activation record consists + +of 5 elements. +These are the argument to f, the saved LP, + +the saved BP, the local variable, and the +saved R1. + +Each time that f is called recursively another +activation record will be added to the stack. + +When we finally return from all of these recursive +calls, we are back to a stack that looks like + +this with a single activation record left +on the stack plus the first argument with + +which the recursive call was made. +The DEALLOCATE(1) instruction then removes + +this argument from the stack. +So the SP is now pointing to the location + +where we previously pushed the argument x-1. +R0 holds the return value from the recursive + +call to f which is the value of f(x-1). +Now, we execute a LD into register R1 of the + +address that is the contents of register BP ++ 0. + +This value is a. +We then ADD R1 to R0 to produce our final + +result in R0. +R0 is now equal to a + f(x-1), so we have + +discovered that our mystery function is a ++ f(x-1). + +Before we continue with analyzing a stack +trace from this problem, let's answer a few + +simpler questions. +The first question is whether or not variable + +a, from the statement a = x & 5, is stored +on the stack and if so where is it stored + +relative to the BP register. +Earlier we saw that our assembly program allocates + +space for one local variable on the stack. +It then stores R1, which holds the result + +of performing a binary ANDC between x and +the constant 5, into the location pointed + +to by the BP register, as shown here. +Next, we want to translate the instruction + +at label yy into its binary representation. +The instruction at label yy is BR(f, LP). + +This instruction is actually a macro that +translates to a BEQ(R31, f, LP). + +Note that because R31 always equals 0, this +branch is always taken. + +The format of the binary representation for +this instruction is a 6-bit opcode, followed + +by a 5 bit Rc identifier, followed by another +5 bits which specify Ra, and then followed + +by a 16 bit literal. +The opcode for BEQ is 011100. + +Rc = LP which is register R28. +The 5-bit encoding of 28 is 11100. + +Ra is R31 whose encoding is 11111. +Now, we need to determine the value of the + +literal in this instruction. +The literal in a branch instruction stores + +the offset measured in words from the instruction +immediately following the branch, to the destination + +address. +Looking at our assembly code for this function, + +we see that we want to count the number of +words from the DEALLOCATE(1) instruction back + +to label f. +Recall that the PUSH and POP macros are actually + +each made of up two instructions so each of +those counts as 2 words. + +Counting back, and accounting for the two +instructions per push and pop, we see that + +we have to go back 16 instructions, so our +literal is -16 expressed as a 16 bit binary + +number. +Positive 16 is 0000 0000 0001 0000, so -16 + +is 1111 1111 1111 0000. +Now, suppose that the function f is called + +from an external main program, and the machine +is halted when a recursive call to f is about + +to execute the BEQ instruction tagged xx. +The BP register of the halted machine contains + +0x174, and the hex contents of a region of +memory are shown here. + +The values on the left of the stack are the +addresses of each location on the stack. + +We first want to determine the current value +of the SP, or stack pointer, register. + +We were told that the machine is halted when +a recursive call to f is about to execute + +the BEQ instruction tagged xx. +And that the BP register was 0x174 at that + +point. +We see that after the BP was updated to be + +equal to the SP in the MOVE operation, two +additional entries were made on the stack. + +The first was an ALLOCATE instruction which +allocated space for one local variable, thus + +making the SP point to location 0x178, and +then PUSH(R1), which saves a copy of R1 on + +the stack, thus moving the SP register one +further location down to 0x17C. + +We now want to answer some questions about +the stack trace itself to help us better understand + +its structure. +We first want to determine the value of local + +variable a in the current stack frame. +We know that a is stored at location BP + + +0. +So a is the variable stored at address 0x174, + +and that value is 5. +From here, we can label all the entries in + +the stack trace as follows. +We saw earlier, that each activation record + +consists of 5 words, the argument x followed +by the saved LP, the saved BP, the local variable, + +and the saved register R1. +We can apply this structure to label our stack + +trace. +Now that our stack trace is fully labeled + +we can take a closer look at the details of +implementing procedures on the beta. + +We begin by looking at the multiple LP values +that were stored on the stack. + +Note that the first one at address 0x144 has +a value of 0x5C whereas the following two + +have a value of 0xA4. +This occurs because the LP value stored at + +address 0x144 is the return address from the +main procedure that originally called procedure + +f, whereas the following two LP values are +the return addresses from recursive calls + +to f made from within the f function itself. +Using this information you can now answer + +the question: What is the address of the BR +instruction that made the original call to + +f from the external main program? +Recall that the value stored in the LP register + +is actually the return address which is the +address of the instruction immediately following + +the branch instruction. +So if the original LP value was 0x5C, that + +means that the address of the branch instruction +was 0x58. + +We can also answer the question, what is the +value of the PC when the program is halted. + +We know that the program was halted just before +executing the instruction at label xx. + +We also know, that the instruction at label +yy makes a recursive call to f. + +We know that the LP value from the recursive +calls is 0xA4. + +This means that the address of the DEALLOCATE(1) +instruction is 0xA4. + +Counting backwards by 4 bytes, and accounting +for the fact that a PUSH operation consists + +of two instructions, we see that label xx += 0x90 and that is the value of the PC when + +the program is halted. +As our last question, we want to consider + +the following: Suppose that you are told that +you could delete 4 instructions from your + +program without affecting the behavior of +the program. + +The 4 instructions to be removed are a LD, +a ST, an ALLOCATE, and a MOVE instruction. + +Removing these instructions would make our +program shorter and faster. + +So, our goal is to determine whether or not +this is possible without affecting the behavior + +of the program. +Let's first consider removing the ALLOCATE + +instruction. +If this instruction is removed, that means + +that we will not be saving space on the stack +for local variable a. + +However, if we take a closer look at the 3 +lines of code highlighted in yellow, we see + +that the actual value of a is first computed +in R1 before storing it in local variable + +a. +Since R1 is going to be saved on the stack + +during each recursive call, we could get away +without saving a on the stack because we can + +find its value in the stored R1 of the next +activation record as shown in the highlighted + +pairs of a and R1 on the stack. +This means that we could safely remove the + +ALLOCATE instruction. +As a result, this also means that we don't + +need the ST operation that stores a on the +stack or the LD operation that reloads a into + +register R1. +Finally, because there are no longer any local + +variables stored on the stack, then the instruction +MOVE(BP,SP) which is normally used to deallocate + +all local variables, can be skipped because +after popping R1, the BP and SP registers + +will already point to the same location. +So, in conclusion the 4 operations can be + +removed from the program without changing +the behavior of the code. \ No newline at end of file diff --git a/YPAbQU7NUZQ.txt b/YPAbQU7NUZQ.txt new file mode 100644 index 0000000000000000000000000000000000000000..c61a265be41113333c9ce3925fb5cb211cf56d67 --- /dev/null +++ b/YPAbQU7NUZQ.txt @@ -0,0 +1,3851 @@ +PROFESSOR: Chapter six, problem +set three, problem set + +two solutions. + +OK. + +Good morning. + +Nice to see you all again +on this mild day. + +I want to start off by thanking +Ashish greatly for + +giving the last three +lectures. + +I have very high confidence in +Ashish, and I'm sure he give + +you excellent lectures and was +able to answer all your + +questions, right? + +But if you feel dissatisfied at +any point, you'll have an + +opportunity to ask the +question again today. + +We will continue now +in chapter six. + +I understand Ashish got up to +section six point one already, + +so that makes my life +a little easier. + +And we'll just continue to plow +ahead through the notes. + +You have as handouts today +chapter six, the outgoing + +problem set, the solutions to +the incoming problem set. + +So does anyone have any comments +or questions or + +suggestions as we go forward +at this point? + +Let's say I'll do a very quick +review of everything so far, + +at least what we need to +proceed, so you'll have a + +chance to ask questions along +there if you like. + +Anyone have anything to say? + +Anyone want to say +thanks to Ashish? + +All right. + +Great. + +OK. + +So a very quick review. + +We first said we were going to +work with a continuous time + +Additive White Gaussian noise +channel, but we quickly + +reduced it to a discrete +time additive white + +Gaussian noise model. + +Vector model, Y equals X plus N, +where the vectors may go on + +as long as you like. + +And implicit in here is we +have some kind of power + +limitation expressed +by various -- + +I know I've probably introduced +too many parameters + +in the early part +of the course. + +But you'll see them all in the +literature, and I thought you + +might as well see the relation +between them all at once. + +The noise. + +The main thing about this +is it's an independent, + +identically distributed noise, +also independent of X, and + +it's characterized simply by +its variance per symbol, or + +average power. + +Again, there are various +notations that we + +can use for its power. + +OK. + +However you express the power +of the signal of the noise, + +you're going to get some +signal-to-noise ratio out of + +that, as long as you use +consistent the same units for + +signal and noise. + +And so the key parameters +of this channel turn + +out to be just two. + +One is the signal-to-noise +ratio. + +And the other is something which +in the discrete time + +domain we might think of as a +data rate, rho, the number of + +bits per two dimensions. + +But we were at pains +to show -- + +and the reason we measure it in +bits per two dimensions is + +that it converts directly to the +spectral efficiency, or we + +sometimes say, the nominal +spectral efficiency, or the + +Nyquist spectral efficiency. + +Basically, this is the spectral +efficiency if you + +assume that you only use the +nominal Nyquist bandwidth. + +And both in 450 and here it was +shown that you can really + +get as close to the nominal +bandwidth as you like, its + +sharp or roll off as you +like, by using filters. + +Very sharp filters or very sharp +digital filters that + +today we can really +realistically get effectively + +to the Nyquist bandwidth. + +So this is a good measure of +nominal spectral efficiency, + +which is an extremely important +parameter, the + +spectral efficiency in +continuous time. + +And then the Shannon limit is +expressed in this very simple + +form that we can never do better +in data rate or nominal + +spectral efficiency than +log of 1 plus SNR. + +And the units are bits +per two dimensions. + +So there's an awful lot about +parameters and units in the + +first part of the course, and +sometimes it's a little + +overwhelming and confusing. + +But in my experience in +engineering is, it's extremely + +important to get the +units right. + +It helps you in thinking +clearly. + +It helps you to focus +on the right things. + +And so in the first couple of +chapters, there's a lot of + +emphasis on getting +the units right. + +For instance, bits per +two dimensions. + +I could simply assert to you +that things are always to come + +out better if you do things +per two dimensions. + +This basically has to do with +Gaussian distributions being + +simpler in two dimensions than +they are in one dimension. + +So you know you can get closed +form integrals in two and four + +and so forth dimensions that you +can't get in one and three + +and so forth dimensions. + +So you know, the geometrical +formulas for the volume of the + +sphere and so forth are much +simpler in even dimensions + +than they are in +odd dimensions. + +This all, I think, has to do +with the fact that really a + +one-dimensional complex Gaussian +variable, or in + +general, complex Gaussian +variables, are in some sense + +mathematically simpler than +real Gaussian variables. + +For instance, the Q function +is a very ugly thing. + +In two dimensions, you can +closed-form integrals with + +probability of error. + +So there's a lot of clues that +we really want to think in + +terms of pairs of +real dimensions. + +All right. + +And then we introduced a +couple more parameters. + +And I understand Ashish +got the questions + +that I get every year. + +Why do we introduce both +of these things? + +SNR norm, which is SNR +normalized by 2 to the rho + +minus 1, that's motivated +directly by the + +Shannon limit formula. + +Or Eb over N_0, which is +SNR divided by rho. + +You know, these are +both more or less + +equivalent to each other. + +From this Eb over N_0 is just 2 +to the rho minus 1 over rho + +times SNR norm, so why do we +introduce both of them? + +And there's not an +intellectually very strong + +argument to introduce +both of them. + +Because one is easily translated +into the other. + +For fixed nominal spectral +efficiency rho, there clearly + +is just a one-to-one +translation. + +We could use either one. + +If you graph something versus +Eb over N_0 or versus SNR + +norm, it's just a matter of +shifting it by this factor. + +They're going to be exactly the +same graph with the 0 dB + +point in a different place, +according to where 0 dB is. + +Philosophically, of course, SNR +norm, which is sometimes + +called the gap to capacity, is +exactly a measure of how many + +dBs away are we from +the Shannon limit. + +Measuring things on +a log scale in dB. + +And so 0 dB is always the +Shannon limit point with SNR + +norm, because this statement +translates into SNR norm is + +greater than 1, which is 0 dB. + +So here the focus is always, how +far are you from capacity? + +How far are you from +the Shannon limit? + +And that really is +the modern view. + +In the early days of coding, the +view was, well, how much + +coding gain can we get +over no coding? + +And as we'll see, Eb over N_0 +is often a very convenient + +parameter to use when we're +focusing on coding gain. + +In fact, for binary linear block +codes, which is what + +we're talking about in chapter +six, we get an extremely + +simple expression that Eb over +N_0 it's just kd over N, where + +N, k, d are the basic parameters +of a block code. + +If you don't know those +yet, you will by + +the end of this lecture. + +And Eb over N_0 is what was put +forward in the early days, + +when the principal coding +application was coding for + +deep space communications. + +It makes sense in the +power-limited regime. + +In the power-limited regime, +we showed that this + +essentially goes -- this is rho +log2 over rho, so up to a + +factor of natural logarithm of +two, these are the same, + +almost independent of the +spectral efficiency, as well. + +And so this is a very natural +thing to use, especially in + +the power-limited regime. + +In the bandwidth-limited regime, +as rho gets large, + +then these things become +very different. + +SNR norm always keeps us in +the neighborhood of 0 dB. + +This thing goes up to 10 dB, +20 dB, 30 dB, and so forth. + +Nonetheless, you'll see in +some literature, people + +continue to measure against Eb +over N_0 maybe I would say, + +just because they don't +know any better. + +Anyway, since I started writing +these notes about + +eight or nine years ago, I've +been advocating SNR norm. + +It's more and more widely +used in our business, + +in the coding business. + +Or equivalently, one always +shows nowadays how far are you + +from capacity, and that's +what SNR norm is about. + +And you can always translate +this into this and this into + +this by this simple formula. + +So that's why we introduce +them both. + +Eb over N_0 is traditional. + +SNR norm is more of the modern +gap to capacity viewpoint. + +Any questions about that? + +Because I understood that +Ashish got a number of + +questions about that. + +Yes? + +AUDIENCE: And the probability +of error you mentioned + +[UNINTELLIGIBLE] is natural +with SNR model. + +PROFESSOR: Well, this +is a slightly + +different point, actually. + +So we go on from this to talk +about the power-limited + +regime, which we defined more +or less arbitrarily as the + +regime where rho is less than +or equal to two bits per two + +dimensions, and the +bandwidth-limited regime, + +which is where rho is larger. + +And at this point, I simply +assert that it's better to do + +everything per two dimensions +in the bandwidth-limited + +regime and to do everything +per bit in the + +power-limited regime. + +And the reason for this is +basically long practice and + +intuition and experience that +things do work out better, and + +this is the proper +normalization. + +But I think at this point +in the course, with your + +background, this is only an +assertion, all right? + +So I simply say, this is the way +we're going to do things + +in bandwidth-limited +and power-limited. + +For most of the rest of the +course, we're going to be in + +the power-limited regime. + +Then we'll come back to the +bandwidth-limited very late in + +the course. + +So you can now forget this +assertion for a while. + +Yes? + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: Well, I'm trying +to focus on that here. + +That if two systems have +different rhos, then you + +should take that into account +in their comparison. + +And when you see charts of a +rate 7/8 system, or a rho 7/4 + +system versus one that's rate +1/8, those are very different + +regimes, and it probably isn't +fair to compare two systems, + +just in terms of their +probability of error versus Eb + +over N_0 at two different +spectral efficiencies. + +What is more fair is to compare +them in terms of their + +gap to capacity. + +You can get more powerful +codes with more + +error-correcting capability the +lower in rate that you go. + +And so you should start from +the point of view that two + +systems with different rho are +incomparable, and then using + +this you can say, but, you know, +if we can get within 1 + +dB of the Shannon limit with +both of them, then they're + +both approximately +equally powerful. + +That would be the modern +point of view. + +But it's really apples and +oranges if they have different + +rates, different rhos. + +Yes? + +AUDIENCE: [INAUDIBLE] + +If [UNINTELLIGIBLE] + +systems modulation +[INAUDIBLE]. + +Then is it fair -- + +because if one of them +has coding -- + +PROFESSOR: If none of them +have coding, well -- + +AUDIENCE: No, just modulation. + +PROFESSOR: So what shall +I say to that. + +In the power-limited regime, +an uncoded system is simply + +binary modulation or 4-QAM, +and there aren't different + +systems to compare, really. + +There's only one baseline +system. + +As you go up into the +bandwidth-limited regime, then + +it is fair to compare +systems of the same + +class, like M by M QAM. + +That's a simple uncoded +system. + +Now there, rho keeps changing. + +rho equals 2, rho equals 4, rho +equals 6, rho equals 8. + +Or you can easily find +intermediate + +rates that are uncoded. + +And there you find that this +normalization makes all these + +systems comparable. + +In fact, we saw that we got a +universal baseline curve for + +the bandwidth-limited regime, +which was independent of rho, + +for, say, the class of 4 by +4, by the class of M by M + +bandwidth-limited QAM systems. + +I'm sorry. + +I got off a plane at nine +o'clock last night, so I may + +not be totally coherent today. + +But all of these systems have +exactly the same baseline + +curve up to the approximations +we've made that their exactly + +four nearest neighbors +and so forth. + +But on a curve of probability +of error per two dimensions, + +per QAM symbol, versus +SNR norm, we + +get a universal curve. + +So that indicates they really +are comparable. + +They form a class where the +performance of the class is + +independent of rho. + +And that's sort of typical of +the bandwidth-limited regime. + +Two systems that differ, that +basically use the same code + +with smaller constellation +or a larger-based uncoded + +constellation are going to be +directly comparable, and are + +probably going to have the +same gap to capacity. + +Going to be just as far away +from the Shannon limit. + +But we don't have that +phenomenon in the + +power-limited case. + +Other questions, or +shall I proceed? + +OK. + +Again continuing what I hope +will be a quick review, but I + +don't want to go any faster than +you're comfortable with. + +We get this baseline curve +for 2-PAM or 2 + +by 2 QAM, same thing. + +So this is the baseline of Pb of +E on a log scale, where we + +typically go down to ten to +the minus six, ten to the + +minus five. + +Here's 0 dB. + +This goes down through +about 9.6 dB here or + +about 10.5 dB here. + +And the ultimate Shannon +limit is over here. + +The ultimate Shannon limit for +very low rho, as rho goes to + +0, is about minus 1.6 dB. + +And we get expressions. + +0 dB is the Shannon limit +at rho equals 1. + +At rho equals 2, it's +up about 1.8 dB. + +Shannon limit for rho equals +2, and so forth. + +And anyway, so we see as a +function of rho, we can + +measure the gap to capacity at +different probabilities of + +error and see how much +coding gain is, + +in principle, possible. + +And then for a coded system, +we can put that on here. + +The effective coding gain +is the distance + +between here and here. + +At some target probability +of error. + +It's going to differ according +to probably of error. + +You found a way of getting a +good, rough-cut estimate, at + +least for not very complicated +codes called the union bound + +estimate for any signal +constellation in any number of + +dimensions. + +So if we have a signal +constellation A, which + +consists of M points in N +dimensions, so forth, + +basically found that we could, +in the power-limited regime, + +get an approximate expression +from considering pairwise + +error probabilities that's +very simple. + +And I used this notation. + +Q of the square root of some +coding gain of the + +constellation times +2 Eb over N_0. + +If it's just 2-PAM then the +coding gain becomes 1. + +This is the average number +of nearest neighbors per + +transmitted bit. + +And so the whole thing reduces +to this expression in terms of + +couple of parameters. + +the principal parameter is the +nominal coding gain, which is + +the minimum squared distance of +A over 4 times the energy + +per bit of this constellation +A. So we really only need to + +know this kind of normalized +measure of goodness of the + +constellation. + +And K_b of A Is the average +number of nearest neighbors. + +I forget what we call it. + +What is the numerator here? + +K_min of A, which itself is an +average, over the number of + +bits that we're actually +sending, which is log2 of the + +size of A. + +So basically we only need to +know a couple of parameters of + +this signal constellation. + +Its minimum square distance +is very important. + +Energy parameter, which we +choose to make the energy per + +bit, or so that we get +this expression. + +And the average number of +nearest neighbors per bit that + +we transmit. + +OK. + +And our best example so far is +the tetrahedral constellation, + +where we basically +pick every other + +point from the 4 simplex. + +Maybe I should do that +in a different color. + +I don't think that's +a different color. + +Nope. + +Anyway. + +You know this quite +well by now. + +And if we do that, we find that +normalizing everything, + +this is 4/3 or 1.25 dB. + +And every point has three +nearest neighbors, and we're + +sending 2 bits, so +this is 3/2. + +So then we get this handy dandy +engineering rule to make + +a quick plot of the union +bound estimate. + +Given that we decided to put +this on a log-log scale to + +start with, all we have to do +to plot this expression -- + +if we're given, as we always +are, the baseline curve, which + +is simply Q to the square +root of 2 Eb over N_0. + +How do you convert this +curve to this curve + +on a log-log plot? + +Well, you simply move it to the +left by the coding gain. + +And you move it up by the +log of whatever K_b is. + +So if the dominant effect is +moving it left, in this case, + +by 1.25 dB -- + +I'm going to wind up getting +about this curve, so I won't + +draw it again -- + +then we move it up by a factor +of 3/2, we developed a rule of + +thumb that said a factor of two +is basically going to cost + +you about 0.2 dB. + +Around ten to the minus five. + +This is just based on the slope +of this baseline curve, + +as long as we're somewhat +in that region. + +So this will cost us about 1/10 +of a dB, so we'll get an + +effective coding gain +of about 1.15 dB. + +So graphically, we take +this curve bodily. + +We move it over 1.25 dB, +and we move it up + +by a factor of 3/2. + +And what we'll find is the +effective coding gain is + +thereby reduced to, I estimate, +about 1.15 dB. + +And this is all just engineering +rules of thumb. + +Nice template. + +I sometimes say you should +fill out a copy of this + +baseline curve, cut it out, put +it in your wallet for the + +duration of this course, +because you'll have the + +opportunity to make +this kind of + +calculation again and again. + +All right. + +So that's union bound SNR. + +For simple constellations, +the union bound + +estimate is very accurate. + +So this is a very good way to +proceed, from an engineering + +point of view. + +We want to write a paper? + +You know, it's a little late +to write a paper on the + +performance of the four simplex +signal constellations, + +but if you wanted to, and you +wanted to have one graph in + +that paper, you would +have the graph of -- + +well, you would actually +probably compute the exact + +error of probability, either by +analysis or by Monte Carlo + +simulation, you would +put that in there. + +But in your first draft of the +paper, you would put in union + +bound estimate and you would +find that wasn't far off. + +OK. + +Any questions on that? + +This has basically got +us up to chapter six. + +So in chapter six now, which +Ashish got into last time. + +This is basically about binary +linear block codes. + +And well, we first just +start talking about + +binary block codes. + +That's what Ashish +did last time. + +We basically take 0 and 1 +as our binary alphabet. + +We take a blocks of length n. + +Sorry. + +Are we using little +n or big N? + +Little n, where n is called +the block plank. + +So we take the set of all binary +symbols of length n, + +and we're going to convert +this to real n space. + +How do we convert it? + +Component-wise, by the +standard 2-PAM map. + +We map 0 into plus alpha, +1 into minus alpha. + +So this maps into plus or +minus alpha to the n. + +So the entire universe of +possible code words that we + +have is this set of 2 to the +n real n-tuples, which are + +simply the vertices of an +n cube of size 2 alpha, + +obviously, right? + +Just like this. + +We have eight possible +vertices in 3-space. + +They obviously all have +the same power. + +They all lie on the surface of +a sphere of squared radius n + +alpha squared. + +So they're not only the vertices +of a cube, they're + +vertices that are spread on +an equal energy sphere. + +And the whole idea is that our +code is going to be some + +subset of this, and the code +will map under the same map, + +which we call S, into +some subset of the + +vertices of the n-cube. + +OK? + +And again, our favorite example +is the tetrahedron. + +For instance, if we take the +code as being 0, 0, 0, 0, 1, + +1, 1, 0, 1 1, 1, 0, those for +binary three-tuples, this maps + +into T, the tetrahedron. + +OK? + +Well, we get this signal +structure, which we've already + +found the coding gain. + +It has a little bit +of coding gain. + +We actually accomplished +something. + +All right. + +So that's the basic idea that +we go through in 6.1. + +That's our favorite example. + +And Ashish also shows you that, +you know, you might + +think this is an awfully +restricted way of designing + +constellations. + +But when we're talking about low +spectral efficiencies, by + +going through the capacity +calculation, we can assure + +ourselves that in principle, +this is not going to be very + +sub-optimal for it. + +Capacity is about the regime +where n gets very large for + +very long block codes. + +We don't lose much in potential +coding gain, or in + +the Shannon limit, equivalently, +by restricting + +the input output input alphabet +to be just these two + +numbers, plus or minus alpha, +I should say, rather than + +using the whole real line as +an input, as long as the + +nominal spectral efficiency is +less than or equal to one bit + +per two dimensions. + +And the exact numbers -- + +at rho equals 1, you lose about +0.2 dB, in principle, + +using the Shannon limit +as your guide. + +And for lower rho, it +just goes to 0. + +And you did this last time. + +OK. + +So it's a very reasonable, and +obviously attractive from an + +implementation point of view, +way of designing signal + +constellations. + +And again, this is basically all +we're going to be talking + +about for the majority of +the course, is signal + +constellations like this. + +But of course as we get to codes +that are thousands of + +bits long, or perhaps even +infinitely long, as in the + +case of convolutional codes and +trellis codes, sometimes + +you forget that we're really +talking about just putting + +points in Euclidian +signal space. + +Because we're going to be very +abstracted back into the + +binary domain. + +But in this course, we're always +thinking of codes as + +means of designing signal +constellations. + +Of course, codes are used far +more widely than just for + +signaling over the additive +white Gaussian noise channel. + +I've sort of packaged this +course as a search to get to + +capacity, we have added +the additive white + +Gaussian noise channel. + +First of all because +this corresponds + +very closely to history. + +Within this package, we can +talk about all of the + +principal classes of codes that +have been developed to + +date, and we can compare them +in some performance terms. + +How close do they get to +capacity on the additive white + +Gaussian noise channel. + +So you get most of what you +would get if you took a + +communications-free view +of coding theory. + +You know, people are interested +in codes for + +computer memories, for +God knows what, + +lots of other things. + +And for many of these other +applications, you are going to + +be interested in the same +class of codes. + +Basically, you're going to want +to maximize the distance + +between code words for a given +rate, which has to do with the + +size of the code. + +And so you're going to be +interested in the same codes. + +Putting it in the framework of +getting to capacity on the + +additive white Gaussian noise +channel gives a motivation, + +gives a very nice story, because +over 50 years, we were + +able to get to capacity, +and gives it a real + +communications flavor. + +Some of you, I'm sure, are here +without any interest in + +communications whatsoever. + +You simply want to know +about coding. + +You will still get that story, +but you'll get it + +in this nice package. + +That's why I do it this way. + +OK. + +I'm about to get +into new stuff. + +End of review. + +Any questions? + +So you must have done +a great job. + +Everyone understands +perfectly. + +All right. + +So now let's talk about, +as I said, binary + +linear block codes. + +When you see the word "linear," +that's a signal that + +there's some algebra ahead. + +And so this is the very first +point at which we get into + +what's called algebraic +coding theory. + +The algebra will be extremely +simple at this + +point, not to worry. + +And what are we doing here? + +First thing we do is to identify +0 and 1 with the + +binary field, which I'm always +going to write as F2. + +The older way of writing this +is GF(2), for Galois field + +with two elements. + +They mean exactly +the same thing. + +Nowadays most people +write just F2. + +Now we have [UNINTELLIGIBLE], +we can write this blackboard + +F. + +And OK. + +Step one. + +We've identified our alphabet +with a field. + +So algebraically, +this is a field. + +Some of you know exactly +what I mean by that. + +Others don't. + +We'll come back to this again. + +Informally, I would say a field +is simply something + +where you can add, subtract, +multiply, or divide. + +Our best examples of that before +now have been the real + +and complex fields. + +There is a more formal +definition of that. + +In this case, we have +only two elements. + +So let me just write down the +tables, which you all know, + +regardless of your background. + +What's the addition table +for this field? + +Well, 0 is the additive +identity. + +So we know that 0 added to +anything gives itself, so that + +gives us three of the entries +of this table. + +What do we put down here? + +There's really only one choice +to satisfy one of the axioms + +of the field, which is that +under addition, the field must + +form a group. + +In particular, that means that +all elements are invertible. + +That means that each row or +column has to be a permutation + +of the group elements. + +And so the only possibility +here is to put in a 0. + +And well, we are forced, if +we're going to make 0 and 1 + +into a field to find an addition +table which is the + +table of mod2 addition. + +You've had this stated +as an axiom before. + +You can derive it just from the +fact that 0 needs to be + +the additive identity, and then +we need to put a 0 in + +here in order to get +invertibility. + +Under multiplication. + +What is the multiplication +table? + +Well, the additive identity +is also a nullifier under + +multiplication in any field. + +So 0 times anything +is equal to 0. + +1 times anything is +equal to itself. + +So that completely determines +the multiplication table. + +Again, just the table of +mod2 multiplication. + +So if I'd done this +axiomatically, I would have + +given you the axioms of field. + +Then I would show that under +this binary addition + +operation, this multiplication +operation, + +we satisfy the axioms. + +I'll do that as we get +into chapter seven. + +OK. + +So now we have 0 1 to the n, +n-tuples, binary n-tuples, we + +will now regard as n-tuples +of field elements, F2. + +And these will be regarded as +vectors in a vector space. + +Well, I'll just say that F2 to +the n is a vector space, which + +clearly has 2 to +the n elements. + +Now again, informally. + +What's a vector space? + +A vector space is always +over a given field. + +In this case, it's going +to be over the + +binary field, of course. + +F2. + +The given field is +called a scalar. + +Just like vector space over +the reals, the scalars are + +real numbers. + +Here the scalars are +elements of F2. + +And what do we have to have to +make something algebraically a + +vector space? + +We have to have that the +addition of two vectors is + +well-defined and gives another +vector, and that the + +multiplication of a vector by +a scalar is well-defined and + +gives another vector in +our vector space. + +All right? + +OK. + +So how are we going to define +that to addition? + +If we want to add +two n-tuples -- + +again, you aren't going to see +anything here that you haven't + +already seen in some +other context. + +What do we do? + +We add them component-wise, +using the component-wise rules + +of field addition. + +OK. + +So we just add two +vector n-tuples, + +component by component. + +We obviously get some result, +which is itself a binary + +vector or an F2 vector. + +No problem there. + +Except that -- + +well, all right. + +As long as we're talking about +all possible n-tuples, the + +result is certainly in the +vector space, right? + +We add two binary n-tuples, +we get a binary n-tuple. + +So the result is +in F2 to the n. + +This is going to be the key test +when we get to subspaces + +of F2 to the n. + +OK. + +And multiplication +is even easier. + +How do we define multiplication +by scalars? + +Well, we only have +two scalars -- + +0 and 1. + +So 0 times any vector is going +to equal the all 0 vector. + +Again, you can view that +as just component-wise + +multiplication of everything +by 0, and since 0 times + +anything equals 0, we're +always going + +to get the 0 vector. + +All right? + +So is the 0 vector in +the vector space? + +Well, yes. + +If we're talking about several +n-tuples, it of + +course always is. + +And one times anything, again, +we can just do this + +component-wise, and it +just gives itself. + +Trivially. + +So since this was a vector in +the vector space, this is + +certainly a vector in +the vector space. + +OK. + +This seems pretty +trivial so far. + +But what's a binary +linear block code? + +Again, focusing on the +linear, is a -- + +now I'll give a formal +definition. + +it's a subspace of F2 +to the n for some n + +called the block length. + +All right. + +What do I mean when +I say a subspace? + +I mean subsets of the elements +of a vector space that itself + +forms a vector space. + +So in this case when I +say subset, I mean a + +set of binary n-tuples. + +OK? + +That itself forms +a vector space. + +OK. + +What are the components +of that? + +To check that it forms a vector +space, let's see. + +Multiplication by scalars is, +again, easy to check. + +If it's going to be a subspace, +then the all 0 -- + +so it has to contain the all 0 +vector in order that when I + +multiply by the scalar +0, I get another + +element of this subspace. + +Multiplication by 1 is always +trivially satisfied. + +If I start off with a set, I +multiply by 1, I'm going to + +get the same set. + +So let's check whether the +elements of a subspace are + +closed under vector addition. + +What do I mean by that? + +I mean if you add two elements +of the of the subspace + +together, you get another +element of the subspace. + +That's the key property +to check. + +Key property -- we can +write that as closure + +under vector addition. + +Which is also called +the group property. + +It means that just under +addition, under vector + +addition, the set of elements +that you have forms a group. + +You add any two elements, +you get another + +element of the subset. + +The example is our favorite +example so far. + +Let's take this little code, +and I'm going to ask. + +Is that a subspace of +F2 to the three? + +So does this equal subspace +of the set of all binary + +three-tuples? + +Anyone care to hazard a guess +whether it is or isn't? + +AUDIENCE: It is. + +PROFESSOR: It is? + +Why? + +AUDIENCE: It has the +all 0 vector. + +PROFESSOR: It has the all +0 vector, first of all. + +Good. + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: And it's closed +under addition. + +Now how might we see that? + +You could, of course, just +take all pair-wise -- + +you could form the addition +table of these four elements, + +and you would find that you +always get another one of + +these elements. + +For instance, 0, 1, 1 plus 1, +0, 1, is equal to 1, 1, 0. + +In fact, you easily see that you +take any two of these, add + +them together, you get +the third one. + +If you call this a, b, and c, +a plus b plus c equals 0, + +addition is the same as +subtraction, because we're in + +a binary field. + +So that means that a plus b +equals c, a equals b plus c, c + +equals b plus a, whatever +you like. + +And of course, if you add 0 to +anything, it's trivially + +closed under that. + +All right. + +So it is. + +It satisfies -- + +it's all you've got to check. + +A more abstract proof of this +would be, this is the set of + +all even-weight three-tuples. + +If I add even to even, I'm +going to get even. + +So of course my result is +going to be another + +even-weight three-tuple, +therefore in the set. + +That's the more algebraic +proof. + +All right. + +Suppose I just add 0, 0, 1 +to all of these things. + +I'll get the set of all +odd-weight n-tuples. + +Add any odd-weight +n-tuple to this. + +Let me take the C prime, +which is the set of + +all odd-weight n-tuples. + +Is that a vector space? + +It doesn't have 0, and in fact, +it's not even closed + +under vector addition. + +All right. + +If I take in C double prime is +equal to 0, 0, 0 0, 1, 1, 1, + +0, 1 and I stop there, +is that a subspace? + +No. + +Because? + +Not closed. + +For instance, if I add these +two together, I would get + +that, and that's missing. + +OK. + +So actually, everything is +much simpler when we're + +talking about finite fields. + +All the finite dimensional +vector spaces consist of a + +finite number of elements. + +It's easier than real and +complex vector spaces. + +There's no analysis involved. + +So forth. + +All right. + +So a binary linear block +code is in a subspace + +of F2 to the n. + +What are some of the key +algebraic facts we know about + +vector spaces from our study +of linear algebra, which I + +assume all of you have had +in some form or another? + +What's a key algebraic property +of a vector space? + +What's the very first +property? + +All vector spaces have a -- + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: Norm? + +No. + +Dimension. + +Dimension, that's +where I'm going. + +What's the significance +of dimension? + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: The definition of +dimension is the number of + +generators in any basis. + +So we're talking about +generators of the vector + +space, or a set of generators +which form a basis. + +If you think we have the same +properties here in the case of + +vector spaces over finite +fields, well, we probably do. + +But let's see how +it works out. + +So we're talking about +things like + +generators, basis, dimension. + +These are all closely +interlinked properties. + +Again, the fact that everything +is finite here + +gives us very elementary +ways of addressing + +all of these concepts. + +We don't have any +geometry yet. + +We don't have norms. + +We don't have distances. + +We don't have angles. + +We'll talk about that +in a minute. + +Here we just have a set that +basically has these two + +properties. + +It contains the all-0 vector, +and it's closed + +as the group property. + +It's closed under +vector addition. + +All right. + +So the first property is that +the all-0 vector is always in + +the subspace, which I'll +represent by C, meaning code. + +So when I talk about a code +now, I'm talking about a + +binary linear block code, +which by definition is a + +vector space, a subspace +of F2 to the n, where + +n is the code length. + +All right. + +Let me try to find a set of +generators for the code. + +All right? + +If somebody gives me a code, +they say, this is a binary + +linear block code. + +Let me see if I can find a +set of generators for it. + +If I find three generators, +then I'll know the + +dimension is three. + +That's basically where +I'm going. + +I'll state this a little bit +more formally as we go ahead. + +So suppose I'm given a code. + +I know it's a binary linear +block code, so I know it has + +the all-0 element. + +So how might I go about finding +a set of generators? + +Let's just take a greedy +algorithm. + +All right? + +Suppose the code contains +only the all-0 vector. + +Is that a subspace? + +What's its dimension? + +0. + +All right? + +So that's a very trivial vector +space, but it's a + +vector space. + +Satisfies the axioms. + +Suppose it is not the +trivial code. + +That means it has more than +the all-0 vector. + +So I take as my first generator +any non-zero vector. + +OK? + +I can always do that. + +Don't have the axiom of choice +involved here, because + +everything is finite. + +So I'm going to take g1 to +be any non-zero vector. + +Now I've got a generator. + +And how many code words +does it generate? + +I want to take the set of all +binary linear combinations of + +all the generators that +I have so far. + +At this point, the binary linear +combinations are 0 + +times g1 and 1 times g1 And that +just gives me this word + +and this word. + +So now I have counted for two +words with one generator. + +Could it be that that's +the whole code? + +Sure. + +The all-0 vector and any +non-zero vector together form + +a one-dimensional subspace. + +That's all you can get +from one dimension. + +So I could be finished +here now. + +But if I'm not finished, there's +still more code words + +that I haven't accounted for. + +Then I greedily pick +a second generator. + +So this is now, let's say, any +vector not generated by g1. + +So I have a branch here. + +Either I've finished or I can +pick another generator g2. + +Now with g1 and g-two, how many +vectors can I generate? + +Let me take all binary +linear combinations. + +So a binary linear combination +is any vector of the form + +alpha1 g1 plus alpha2 g2 where +these are both scalars. + +And therefore this can be 0 or +1, this could be 0 or 1. + +So what have I got now? + +I've got 0, g1 g2 and g1 plus g2 +I've got four binary linear + +combinations of two +generators. + +Could that be the whole code? + +Certainly. + +At this point, again, consider +our standing example. + +I start out what I take +as my first generator. + +Let me take g1 equal 1 0, 1, g2 +equals whatever, 0, 1, 1. + +Then if I take all binary linear +combinations of these + +two generators, I'm going to +get the whole code, right? + +These four code words. + +They can all be expressed +in this form. + +Or I'm not done, and then +I have to pick g3. + +And how many binary linear +combinations are there of g1, + +g2, and g3? + +Eight. + +Are they all necessarily +in my subspace? + +Yes, by the fact that the +subspace is closed under + +scalar multiplication. + +Alpha g1. + +Alpha1 g1, alpha2 g2 alpha3 g3 +are all in the subspace. + +Any vector addition of any of +these scalar multiples is in + +the subspace. + +So I get now eight possible +elements of the subspace, and + +I either may be done or not. + +Continuing in this way, I get +some number gk of generators, + +just by picking greedily the +next one until I'm done. + +All right? + +When I'm done -- + +so I have to stop. + +Why do I have to stop? + +All right. + +Let's look at the size. + +At each point here, this +accounts for two code words, + +this for four, this for eight, +this for 2 to the k. + +How many binary n-tuples +are there? + +2 to the n. + +All right? + +So I clearly can't find more +than n generators. + +More more than n independent +generators, in the sense that + +the set of all the +binary linear + +combinations are distinct. + +All right. + +So k is, at most, +going to be n. + +So I will stop in a finite +number of steps. + +I'll stop at some number k. + +When I've stopped, that's +because the code consists of + +all binary linear combinations +of these k generators, and + +therefore has size 2 to the k. + +So the only possible size of a +subspace is 2 to the k for k + +less than n. + +A power of 2 where the +power is, at most, n. + +So any subspace besides +the subspace -- + +I'm repeating myself. + +OK. + +So this means I found a basis. + +Does this mean that all possible +bases of any subspace + +have the same size? + +Well yeah, it must. + +I mean, I've proved now that any +subspace has to have this + +size 2 to the k for some k. + +So obviously, if I go through +this process, no matter how I + +choose my generators, I could +choose any pair of these + +non-zero n-tuples as +my generators. + +So that would be a +legitimate basis. + +Take any two out +of these three. + +But it's always going to take +exactly two of them, right? + +Why? + +Because the size of this +subspace is four. + +Two to the two. + +So if I go through this process, +I'm always going to + +come up with k generators, where +k is the log to the base + +2 of the size of this code that +I was given, which I was + +told was a linear code, meaning +it's a subspace. + +So I'm somewhat free to choose +the generators, but I'm always + +going to come up with k of +them if the code has + +size 2 to the k. + +So a basis is a set of k +linearly independent k-tuples, + +where linear independence has +the same meaning here as + +you're accustomed to, meaning +that all linear combinations + +of the k generators +are distinct. + +So I get 2 to the k distinct +elements of the code. + +And I say the dimension +of the code is k. + +In this case, basically it's the +size of the code is 2 to + +the k, then its dimension +is k. + +Has to be. + +And all basis have k +generators in them. + +And there are, in general, +many ways to pick them. + +All right? + +So just by considering this +greedy basis construction + +algorithm, I basically find the +size of any subspace is a + +power of two, and the power +is equal to the dimension. + +And any basis is going to +have that cardinality. + +Are you with me? + +This is a pretty simple proof. + +And I call this an n, k binary +linear block code. + +n being the length. + +That just means that every code +word is an n-tuple over + +the binary field. + +And k is the dimension. + +So an n, k binary linear block +code has size 2 to the k. + +That's 2 to the k distinct +code words. + +Main example is this guy. + +Easy? + +Any questions? + +I think this is clear. + +AUDIENCE: Can n use the number +of code word, I take + +like 2 to the k? + +PROFESSOR: n is something I +specify a priori as the length + +of every vector in the code. + +In other words, it has size 2 to +the k, and it's a subset of + +the set of all binary +n-tuples, which + +I write like that. + +In other words, the +elements of the + +code are binary n-tuples. + +If I write them out, each +one has length n. + +OK? + +We're good? + +What are some other examples? + +The simplest codes you can +think of is, first of + +all, an n, 0 code. + +That means a code with dimension +zero, has size what? + +1. + +And what does it consist of? + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: Yeah. + +So this is the so-called trivial +code, just containing + +the all-0 word. + +Has to mention 0. + +It is a binary linear block +code, but it's not much use + +for communication. + +So but nonetheless, we include +that in this family. + +Another trivial one is n, n. + +What's that? + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: F2 to the n, right. + +What's its size? + +2 to the n. + +That means it has to contain all +distinct binary n-tuples. + +So this is called the +trivial code. + +This is called the +universe code. + +Contains the entire universe +of binary n-tuples. + +Let's get some slightly +less trivial ones. + +n, 1. + +What would that be? + +An n, 1 code. + +What's its size? + +2. + +What does it consist of? + +The 0 word, and? + +Any other non-zero generator. + +And that's correct. + +This can be 0 and any generator, +two words. + +In communications, where we want +to maximize the distance, + +in some sense, between the +two code words, what is g + +always taken as? + +0,1's, right. + +So if it's in particular the +all-0 and the all-1 word, + +which I might write as a vector +of 0's and a vector of + +1's, this is called the +repetition code. + +The binary repetition +code of length n. + +It either gives me a 0 and I +repeat it n times, or gives me + +a 1 and I repeat it n times. + +So whenever you see n,1, you +can pretty well assume it's + +the repetition code, though +it might be any pair 0, g. + +And n, minus 1. + +This is an interesting one. + +Again, while this could +be a lot of things, in + +communications, whenever you see +this, this will always be + +the set of all even-weight +n-tuples. + +In other words, the set of all +n-tuples with even parity such + +that if you sum up all of +the components of any + +vector, mod2 equals 0. + +OK? + +So this I will call the single +parity check, or more briefly, + +the SPC code, or the +even-weight code. + +That's equally good. + +And here we maybe should do +a little bit more work. + +Say, is this in fact +a subspace? + +Does it include the all-zero +code word? + +Yes, all-zero has even weight. + +The sum of any two even-weight +code words, an even-weight + +code word, an even-weight +n-tuple. + +Yes. + +As here. + +This is an example. + +This is the three, +two SPC code. + +OK. + +Why is this dimension +n minus one? + +AUDIENCE: [INAUDIBLE] + +Is every code word orthogonal +to the one-vector? + +PROFESSOR: OK. + +That's an excellent answer. + +It's a little advanced +for us right now. + +I'm looking for an elementary +argument. + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: OK. + +So you're saying we have +a set of generators + +that looks like this. + +Is that what you're saying? + +You are correct. + +And how many such generators +are there? + +There are n minus 1 of them. + +I always like to find the most +elementary argument possible. + +I think the most elementary +argument here is that the + +number of even-weight n-tuples +is equal to the number of + +odd-weight n-tuples, and +together they form the set of + +all n-tuples. + +So exactly half of the n-tuples +are even weight. + +That means there are 2 to the n +minus 1 of them, 2 to the n + +over 2, and therefore, the +dimension must be n minus 1. + +But perhaps this is just +as elementary a proof. + +Well, however you do it, you'll +find that there are 2 + +to the n minus 1 of them, or +that here is clearly a set of + +generators. + +It might take a few more lines +to show that every even-weight + +code word is a linear +combination of this particular + +set of generators, but +it's certainly true. + +All right. + +So these four classes of codes, +these two entirely + +trivial ones, these two which +are actually somewhat more + +interesting for coding +purposes -- + +we've already seen, we can get a +coding game with this length + +three, dimension two code -- + +are basically the simplest +codes we can think of. + +The simplest binary linear +block codes. + +Now we'll see them +again and again. + +They turn up. + +All right? + +So the whole course is +going to be about + +finding 1's in between. + +More complicated ones. + +There's clearly more +room to play. + +For instance, if k is equal to +half of n, which means that + +rho is equal to one bit per two +dimensions, there's a lot + +of possibilities. + +And so we're going to explore +those possibilities. + +AUDIENCE: [INAUDIBLE] + +[UNINTELLIGIBLE] + +PROFESSOR: Sure. + +Let's take the 6,5 code +generated by these five + +generators. + +Well, it contains some + +odd-weight code words, obviously. + +But it's not as interesting from +a coding point of view. + +It's not the only one, +but it's the only one + +you'll ever see here. + +All right. + +Let's see. + +One thing I didn't point out +in the notes but probably + +should have here is, what is rho +for an n, k binary linear + +block code? + +How many bits can we send? + +Suppose we take the Euclidean +image of this. + +It is going to have 2 to the k +points, 2 to the k vertices of + +the n-cube, and so +what is rho? + +What is the rate in bits +per two dimensions? + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: Right. + +The rate is basically k over n +over 2, if you like, or 2 k + +over n bits per two +dimensions. + +You can send k bits in n +dimensions, or 2 k over n bits + +per two dimensions. + +And since k can't be larger than +n, this is going to be + +less than or equal to two +bits per two dimensions. + +So again, we see we're +definitely in the + +power-limited regime, and that +we can really get any nominal + +spectral efficiency between 0 +and 2 by choosing k and n + +appropriately. + +All right. + +So n and k determine the rate, +determine the nominal spectral + +efficiency. + +All right. + +Let's now talk about things that +I think are also very old + +hat to you. + +I mean weight and distance. + +But we begin to get into areas +that show us that these vector + +spaces are very different from +the real and complex vector + +spaces that we're +accustomed to. + +So what are we doing now? + +We're starting to get into the +geometry of this vector space. + +The geometry is not Euclidean +geometry, but + +it's Hamming geometry. + +We define the Hamming weight +of a vector as simply the + +number of 1's in v. So the +Hamming weight of the all-0 + +vector is 0, the Hamming weight +of the all-1 vector is + +n, and in general, the Hamming +weight is somewhere + +between 0 and n. + +Just the number of 1's. + +Pretty simple. + +And given two vectors x and +y, what is their distance? + +The Hamming distance between x +and y is equal to the Hamming + +weight of x minus y. + +This is the standard way of +converting a weight metric + +into a distance metric. + +Or because addition is the +same as subtraction in a + +binary vector space, we might +equally well write this is as + +the Hamming weight +of x plus y. + +And more informally, this is +simply the number of places in + +which they differ. + +OK. + +So if x and y are identical, +then x plus y is equal to 0 + +and the distance is 0. + +If they are complementary, y is +the complement of x, then + +they differ in every place. + +The sum will then be the all-1 +vector, and the weight, the + +Hamming distance, will be n. + +And so again, the Hamming +distance is somewhere between + +0 and n, measures how +different they are. + +Clearly going to be important +for coding. + +It's going to translate directly +into Euclidean + +distance under this standard +2-PAM map. + +OK. + +Again, let's check that it +satisfies the distance axioms. + +I don't know how many of you +have seen this, but let's see. + +What are the distance axioms? + +Strict non-negativity. + +In other words, the Hamming +distance between x and y -- + +that's a single comma -- + +is greater than or equal to +0, and equality if and + +only if x equals y. + +That's what strict means. + +So if we find the Hamming +distance is 0, we can assert + +that x equals y. + +We have, of course, symmetry. + +The Hamming distance between +x and y is the same as the + +Hamming distance between +y and x. + +Order doesn't matter. + +And finally we have the triangle +inequality, that the + +Hamming distance between x and z +certainly can't be more than + +the Hamming distance between +x and y plus the Hamming + +distance between y and z. + +If x differs from y in only n1 +places, and y differs from z + +in only n2 places, then clearly +z can't differ from x + +in more than n1 plus +n2 places. + +So check, check, check. + +This is a legitimate metric for +defining a geometry on the + +space, and this is the one that +we use on the space of + +all n-tuples. + +But notice it's not all like +the Euclidean Distance. + +Now when we have a +linear code -- + +let's combine these things. + +When we have a linear code, we +have a group property which + +is, let me write it this way. + +If we take any code word and add +it to any other code word, + +that's in the code. + +And furthermore, c plus c prime +is not equal to c prime + +plus c single prime, c +plus c single prime, + +because we can -- + +well, I'll finish it. + +Unless c prime equals +c double prime. + +Why is that? + +We can do subtraction, +cancellation. + +Cancel c out from each side. + +So if we add c to c double +prime, we're going to get a + +different result from adding c +to c prime, if c prime and c + +double prime are different. + +So this implies that +c plus C -- + +I write that as an abbreviation +for the set of + +all c plus c prime, as a c prime +runs through the code C. + +So this is the 2 to the k sums +of the code plus any code word + +in the code. + +Sorry if I don't write +down all steps. + +What is that going to be? + +C. How did we conclude that? + +AUDIENCE: [INAUDIBLE] + +[UNINTELLIGIBLE] + +PROFESSOR: Perfect. + +Did you all hear that? + +By the group property, +each one of these + +things is in the code. + +By this argument, no two +of them are the same. + +That means I get 2 to the k +distinct elements all in the + +code, that's got to be the code, +because the code only + +has 2 to the k elements. + +All right. + +So if I add a code word -- + +in other words, if I write +down the code -- + +0, 0, 0, 0, 1, 1, 1 0 1, 1 1 0- +and I add any code word to + +it -- say I add 0 +1 1 to the code. + +So let me just do one column +of the addition table. + +I get 0, 1, 1, 0, 0, 0, +1, 1, 0, 1, 0, 1. + +I'll get the code +itself again. + +This has a very important +property. + +The set of Hamming distances C +and c prime, as c prime runs + +through c, from any given code +word C, it is independent of + +C. So I can start from any code +word, measure the Hamming + +distances, the 2 to the k +Hamming distances to all other + +code words, including +C itself -- + +let c prime run through the +entire code, I'm going to get + +a set of 2 to the k distances +called the distance + +profile of the code. + +And I claim that it doesn't +matter which code + +word I start from. + +I'm going to get the same +distance profile regardless of + +where I start. + +In other words, the set of all +distances from the all-0 word + +here, which is 0, 2, 2, 2, is +the same as the set of all + +distances from the 0, +1, 1, code word, + +which is 2, 0, 2, 2. + +And the proof is basically +that this is simply the + +Hamming weight of C plus c prime +as c prime runs through + +C. What is this equal to? + +So the proof is that this is +equal to the Hamming weight of + +c prime as c prime +runs through C. + +So the distance profile from any +code word is simply equal + +to the weight profile +of the code itself. + +The weight profile of this code +is 0, 2, 2, 2, Start from + +any code word, measure the +distances to other code words, + +I'm always going to get +0, 2, 2, 2, 0, to + +itself, and the others. + +Sounds sort of like the +tetrahedron, doesn't it? + +It's zero distance from a code +word to itself and equal + +distance to all the other +code words, in + +that particular case. + +OK. + +So again, everything is +very elementary here. + +The distance profile is +independent of C and equal to + +the weight profile. + +So this has an extremely +important corollary. + +What's the minimum Hamming +distance of the code? + +You might expect this +is going to be an + +important code parameter. + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: The minimum Hamming +distance between any two code + +words is going to +be equal to -- + +I think you said it. + +AUDIENCE: The 0 +[UNINTELLIGIBLE]. + +PROFESSOR: Non-zero +is important here. + +If the distance profile is equal +to the weight profile, + +one of the weights is always +going to be zero. + +And that corresponds to the +distance between a code word + +and itself. + +All right. + +If I go through all the other 2 +to the k minus 1 distances, + +they're going to be weights. + +They're going to be the +distances from a code to all + +other code words. + +And the minimum distance is +simply going to be the minimum + +non-zero weight of the code. + +For example, in this code, the +minimum Hamming distance + +between any two distinct code +words is going to be equal to + +the minimum distance from +the 0 code word -- + +that's another way +of doing it. + +Since it's independent of C, we +may as well take the base + +code word C to be zero. + +And then what's the minimum +distance to 0? + +To the 0-code word? + +It's the minimum weight. + +From the 0 code word, distance +equals weight. + +So the minimum distance is the +minimum weight of any non-zero + +code word, which for +this code is two. + +Now here the weight profile +is 0, 2, 2, 2, 0. + +The distance profile from any +code word to all the others is + +0, 2, 2,2 2. + +This is always the distance +to itself. + +So minimum distance to +other code words is + +always going to be two. + +Furthermore, the number of +nearest neighbors -- + +to go back and use chapter +five terminology -- + +the number of nearest neighbors +is going to be the + +number of code words that have +that minimum weight -- + +in this case, three. + +Still sounding a lot like +a tetrahedron, isn't it? + +This easy map between Hamming +distance and Euclidean + +distance for this case and in +general for all of our cases. + +So corollary. + +The minimum Hamming distance, +which implicitly means between + +two distinct code words of C, +is equal to the minimum + +non-zero weight of C, and the +number of minimum weight code + +words is independent -- + +I'm doing this backwards. + +From any code word, the number +of code words that distance, + +let's call this d, is equal +to the number of + +weight d code words. + +Sorry, you probably +can't see that. + +All right. + +So we get this symmetry property +for codes that + +follows from the group property +of the code that if + +we stand on any code word and +look out, we're always going + +to see the same thing. + +We have this constant. + +It's actually easiest to see +this when we make the map from + +the code to the Euclidean +image of the code. + +So the Euclidean image S of C +of the code word is going to + +be some set of 2 to the +k vertices of an + +n-cube of side alpha. + +Let's talk about the Euclidean +image of these properties. + +If the minimum Hamming distance +of the code is d, + +what's the minimum squared +Euclidean distance between + +elements of S of +C going to be? + +Well, let's do it coordinate +by coordinates. + +Let's take two code words, +C and c prime, let's say. + +And let's suppose we have +some Hamming distance + +between C and c prime. + +That means that c and c prime +differ in the Hamming + +distance, number of places. + +So if we map this into the +corresponding pair of vertices + +of the n-cube in Euclidean +space, S of C and S of c + +prime, how many coordinates are +these going to differ in? + +It's going to differ in same +number of coordinates, D_h. + +If they don't differ, what's +Euclidean squared distance in + +those coordinates? + +0. + +If they do differ, the Euclidean +squared distance is + +4 alpha squared. + +So the Euclidean distance D_e +between S of C and S of c + +prime is simply going to be +4 alpha squared times the + +Hamming distance between +C and c prime, yes? + +So I should say this is the +squared Euclidean distance. + +Why do we always talk about the + +squared Euclidean distance? + +Because it's additive, +coordinate-wise. + +And the Hamming distance is +additive, coordinate-wise. + +So there's a nice +easy map here. + +So what does this mean d_min +squared is going to be? + +d_min squared of, let's say, S +of C. This constellation that + +we've formed by taking the +Euclidean image of c. + +The minimum square distance +between points in S of C is + +just going to be 4 alpha squared +times d, where I don't + +think I ever -- + +d equals min Hamming distance. + +And we're always going to talk +about n, k, d as the three key + +parameters of a binary +linear block code. + +n is the code length, F2 to the +n, k is the dimension, d + +is the minimum Hamming +distance. + +So by going into this Hamming +geometry, we've got a third + +key property of the code. + +And we see it's key, because we +can get the minimum squared + +distance between this Euclidean +image constellation, + +just 4 alpha squared d. + +AUDIENCE: nd makes +a probability of + +[UNINTELLIGIBLE] that is +dependent on [UNINTELLIGIBLE] + +then. + +PROFESSOR: Correct. + +This is all we need to know to +get the union bound estimate. + +Well, a few more things. + +We need to know what K_min +average of S of C. And what is + +that going to be? + +This is simply going to be the +number of words in the code. + +To get this minimum squared +distance, we need a Hamming + +distance of d. + +So the number of words in the +code of distance d, which is + +given by the parameter n sub d, +is simply going to be the + +number of nearest neighbors. + +Not just the average distance, +but I want to emphasize this + +symmetry property. + +If we stand on any point, on +any vertex of this cube in + +n-space, which is the code +vertex, and we look at all the + +other points in the +constellation, no matter which + +point we stand on, we +will always see the + +same profile of distances. + +We'll see precisely nd code +words at Euclidean distance 4 + +alpha squared d. + +We'll see nd plus 1 at Euclidean +squared distance 4 + +alpha squared d plus 1, and so +forth, right up the profile. + +So there's complete symmetry +in the constellation. + +In that universe, you don't know +which code point you're + +standing on just by looking out, +because the world looks + +the same to you. + +Is that clear? + +OK. + +So from a communications point +of view, this is important, + +because it means it doesn't +matter what code word we send. + +The probability of error from +any code word is going to be + +the same as the probability of +error from any other code + +word, because the geometry +is exactly the same. + +The Voronoi regions are +all the same shape. + +So given the exact probability +of error, not just the + +union-bound estimate, is going +to be independent of which + +code word was sent. + +This all follows from the fact +that it's a linear code and + +therefore has the group +property, which translates + +into this very strong +geometrical uniformity + +property in Euclidean space. + +Or actually in Hamming space +too, but it's more striking in + +Euclidean space. + +OK? + +So we have everything we +need to write down + +the union bound estimate. + +Union bound estimate was just +the probably of error per bit + +is well approximated by K_b of +constellation, in this case, S + +of C, times Q of the square root +of the coding gain of the + +constellation times +2 Eb over N_0. \ No newline at end of file diff --git a/YUjdyKhWt6E.txt b/YUjdyKhWt6E.txt new file mode 100644 index 0000000000000000000000000000000000000000..4fe1f840b3325aa099071e64d3b899f0a913b7ab --- /dev/null +++ b/YUjdyKhWt6E.txt @@ -0,0 +1,1179 @@ +align:start position:0% + +welcome back so in this session we're + + align:start position:0% +welcome back so in this session we're + + + align:start position:0% +welcome back so in this session we're +going to use the Matrix method to solve + + align:start position:0% +going to use the Matrix method to solve + + + align:start position:0% +going to use the Matrix method to solve +this linear system of differential + + align:start position:0% +this linear system of differential + + + align:start position:0% +this linear system of differential +equations these are X doal 6x + 5 Y and + + align:start position:0% +equations these are X doal 6x + 5 Y and + + + align:start position:0% +equations these are X doal 6x + 5 Y and +Y dot equal x + 2 y so why don't you + + align:start position:0% +Y dot equal x + 2 y so why don't you + + + align:start position:0% +Y dot equal x + 2 y so why don't you +take a few minutes to write down a + + align:start position:0% +take a few minutes to write down a + + + align:start position:0% +take a few minutes to write down a +system in Matrix form and go through the + + align:start position:0% +system in Matrix form and go through the + + + align:start position:0% +system in Matrix form and go through the +method of the M The Matrix method to + + align:start position:0% +method of the M The Matrix method to + + + align:start position:0% +method of the M The Matrix method to +solve it and I'll be right back + + align:start position:0% + + + + align:start position:0% + +welcome back so let's write down this + + align:start position:0% +welcome back so let's write down this + + + align:start position:0% +welcome back so let's write down this +system in Matrix + + align:start position:0% +system in Matrix + + + align:start position:0% +system in Matrix +form we would have a vector with entries + + align:start position:0% +form we would have a vector with entries + + + align:start position:0% +form we would have a vector with entries +X and Y Prime equals a matrix with entry + + align:start position:0% + + + + align:start position:0% + +65 one two + + align:start position:0% + + + + align:start position:0% + +multiplying the colum Vector X Y so now + + align:start position:0% +multiplying the colum Vector X Y so now + + + align:start position:0% +multiplying the colum Vector X Y so now +we did big part of the work the Matrix + + align:start position:0% +we did big part of the work the Matrix + + + align:start position:0% +we did big part of the work the Matrix +method tells us that we need to find the + + align:start position:0% +method tells us that we need to find the + + + align:start position:0% +method tells us that we need to find the +aen values of this Matrix to be able to + + align:start position:0% +aen values of this Matrix to be able to + + + align:start position:0% +aen values of this Matrix to be able to +basically diagonalize it and seek aen + + align:start position:0% +basically diagonalize it and seek aen + + + align:start position:0% +basically diagonalize it and seek aen +vectors so that then we can just read + + align:start position:0% +vectors so that then we can just read + + + align:start position:0% +vectors so that then we can just read +off the solutions and write the solution + + align:start position:0% +off the solutions and write the solution + + + align:start position:0% +off the solutions and write the solution +of the system as a linear combination of + + align:start position:0% +of the system as a linear combination of + + + align:start position:0% +of the system as a linear combination of +the aen vectors that we found so let's + + align:start position:0% +the aen vectors that we found so let's + + + align:start position:0% +the aen vectors that we found so let's +look for The Egan values first + + align:start position:0% + + + + align:start position:0% + +the aen values would be computed by + + align:start position:0% +the aen values would be computed by + + + align:start position:0% +the aen values would be computed by +seeking the determinant of this + + align:start position:0% + + + + align:start position:0% + +Matrix in this + + align:start position:0% +Matrix in this + + + align:start position:0% +Matrix in this +form 6 minus lamba 5 1 2 minus Lambda + + align:start position:0% +form 6 minus lamba 5 1 2 minus Lambda + + + align:start position:0% +form 6 minus lamba 5 1 2 minus Lambda +we're going to have an equation on + + align:start position:0% +we're going to have an equation on + + + align:start position:0% +we're going to have an equation on +Lambda solve for Lambda and the + + align:start position:0% +Lambda solve for Lambda and the + + + align:start position:0% +Lambda solve for Lambda and the +solutions will be out a + + align:start position:0% + + + + align:start position:0% + +values so the determinant would be 6 + + align:start position:0% +values so the determinant would be 6 + + + align:start position:0% +values so the determinant would be 6 +minus Lambda multiplying 2us LDA minus 5 + + align:start position:0% +minus Lambda multiplying 2us LDA minus 5 + + + align:start position:0% +minus Lambda multiplying 2us LDA minus 5 +1. 5 = to0 so here the Landa Landa gives + + align:start position:0% +1. 5 = to0 so here the Landa Landa gives + + + align:start position:0% +1. 5 = to0 so here the Landa Landa gives +us a land Square we have Min - 6 L minus + + align:start position:0% +us a land Square we have Min - 6 L minus + + + align:start position:0% +us a land Square we have Min - 6 L minus +2 land which would be minus 8 Landa and + + align:start position:0% +2 land which would be minus 8 Landa and + + + align:start position:0% +2 land which would be minus 8 Landa and +then we would have 2. 6 which is 12 + + align:start position:0% +then we would have 2. 6 which is 12 + + + align:start position:0% +then we would have 2. 6 which is 12 +minus + + align:start position:0% +minus + + + align:start position:0% +minus +5 which gives us a seven so quadratic + + align:start position:0% +5 which gives us a seven so quadratic + + + align:start position:0% +5 which gives us a seven so quadratic +equation on in Landa and you can + + align:start position:0% +equation on in Landa and you can + + + align:start position:0% +equation on in Landa and you can +factorize it and find the solutions + + align:start position:0% +factorize it and find the solutions + + + align:start position:0% +factorize it and find the solutions +which as Lambda 1 = 2 1 Lambda 2 equal 2 + + align:start position:0% +which as Lambda 1 = 2 1 Lambda 2 equal 2 + + + align:start position:0% +which as Lambda 1 = 2 1 Lambda 2 equal 2 +7 okay so we're done with the first part + + align:start position:0% +7 okay so we're done with the first part + + + align:start position:0% +7 okay so we're done with the first part +first part these are aen values they're + + align:start position:0% +first part these are aen values they're + + + align:start position:0% +first part these are aen values they're +not repeated they're just completely + + align:start position:0% +not repeated they're just completely + + + align:start position:0% +not repeated they're just completely +different and real valued so now we're + + align:start position:0% +different and real valued so now we're + + + align:start position:0% +different and real valued so now we're +going to look at the aen vectors + + align:start position:0% +going to look at the aen vectors + + + align:start position:0% +going to look at the aen vectors +Associated to each aen + + align:start position:0% +Associated to each aen + + + align:start position:0% +Associated to each aen +value um + + align:start position:0% + + + + align:start position:0% + +so so first aen + + align:start position:0% +so so first aen + + + align:start position:0% +so so first aen +Vector would be associated with Lambda 1 + + align:start position:0% +Vector would be associated with Lambda 1 + + + align:start position:0% +Vector would be associated with Lambda 1 +equals to 1 + + align:start position:0% + + + + align:start position:0% + +okay so we would be solving the + + align:start position:0% +okay so we would be solving the + + + align:start position:0% +okay so we would be solving the +system uh we would be solving the system + + align:start position:0% +system uh we would be solving the system + + + align:start position:0% +system uh we would be solving the system +with the new Matrix 6 minus one I'm + + align:start position:0% +with the new Matrix 6 minus one I'm + + + align:start position:0% +with the new Matrix 6 minus one I'm +going to spell out this one so + + align:start position:0% +going to spell out this one so + + + align:start position:0% +going to spell out this one so +that 2 - one so this is just our land + + align:start position:0% +that 2 - one so this is just our land + + + align:start position:0% +that 2 - one so this is just our land +multiplying an unknown Vector with + + align:start position:0% +multiplying an unknown Vector with + + + align:start position:0% +multiplying an unknown Vector with +composant and 1 and + + align:start position:0% +composant and 1 and + + + align:start position:0% +composant and 1 and +A2 equals to zero + + align:start position:0% +A2 equals to zero + + + align:start position:0% +A2 equals to zero +vector and basically here the unknowns + + align:start position:0% +vector and basically here the unknowns + + + align:start position:0% +vector and basically here the unknowns +are A1 and A2 okay so this is + + align:start position:0% +are A1 and A2 okay so this is + + + align:start position:0% +are A1 and A2 okay so this is +simply five five 1 and + + align:start position:0% +simply five five 1 and + + + align:start position:0% +simply five five 1 and +one A1 A2 equal to 0 0 so as you saw + + align:start position:0% +one A1 A2 equal to 0 0 so as you saw + + + align:start position:0% +one A1 A2 equal to 0 0 so as you saw +before here basically we can read off + + align:start position:0% +before here basically we can read off + + + align:start position:0% +before here basically we can read off +the equation as being 5 A1 + 5 A2 equal + + align:start position:0% +the equation as being 5 A1 + 5 A2 equal + + + align:start position:0% +the equation as being 5 A1 + 5 A2 equal +to0 and another one which is A1 + A2 + + align:start position:0% +to0 and another one which is A1 + A2 + + + align:start position:0% +to0 and another one which is A1 + A2 +equal to Z they are the same equations + + align:start position:0% +equal to Z they are the same equations + + + align:start position:0% +equal to Z they are the same equations +so really we just have A1 + A2 equal to + + align:start position:0% +so really we just have A1 + A2 equal to + + + align:start position:0% +so really we just have A1 + A2 equal to +zero and so our Vector + + align:start position:0% +zero and so our Vector + + + align:start position:0% +zero and so our Vector +V1 could be picked to just have compon + + align:start position:0% +V1 could be picked to just have compon + + + align:start position:0% +V1 could be picked to just have compon +component one for example A1 equals to + + align:start position:0% +component one for example A1 equals to + + + align:start position:0% +component one for example A1 equals to +one and its second component would just + + align:start position:0% +one and its second component would just + + + align:start position:0% +one and its second component would just +be minus one that would be one pick for + + align:start position:0% +be minus one that would be one pick for + + + align:start position:0% +be minus one that would be one pick for +our V1 okay we could normalize this + + align:start position:0% +our V1 okay we could normalize this + + + align:start position:0% +our V1 okay we could normalize this +Vector if we wanted to I'm just going to + + align:start position:0% +Vector if we wanted to I'm just going to + + + align:start position:0% +Vector if we wanted to I'm just going to +keep it like this for now so if we look + + align:start position:0% +keep it like this for now so if we look + + + align:start position:0% +keep it like this for now so if we look +now for the second negative vector + + align:start position:0% +now for the second negative vector + + + align:start position:0% +now for the second negative vector +corresponding to the second angle value + + align:start position:0% + + + + align:start position:0% + +S I would be looking for the components + + align:start position:0% +S I would be looking for the components + + + align:start position:0% +S I would be looking for the components +of this vector by doing the + + align:start position:0% +of this vector by doing the + + + align:start position:0% +of this vector by doing the +similar solving for the same thing and + + align:start position:0% +similar solving for the same thing and + + + align:start position:0% +similar solving for the same thing and +I'm going to spell it out again so that + + align:start position:0% +I'm going to spell it out again so that + + + align:start position:0% +I'm going to spell it out again so that +you see where the terms are coming from + + align:start position:0% +you see where the terms are coming from + + + align:start position:0% +you see where the terms are coming from +it's just six minus the value of + + align:start position:0% + + + + align:start position:0% + +LDA 0 Z so here we have 6 - 7 which is 1 + + align:start position:0% +LDA 0 Z so here we have 6 - 7 which is 1 + + + align:start position:0% +LDA 0 Z so here we have 6 - 7 which is 1 +five and then we have 1 and 2 - 7 which + + align:start position:0% +five and then we have 1 and 2 - 7 which + + + align:start position:0% +five and then we have 1 and 2 - 7 which +is minus 5 so really what do we have is + + align:start position:0% +is minus 5 so really what do we have is + + + align:start position:0% +is minus 5 so really what do we have is +an + + align:start position:0% +an + + + align:start position:0% +an +equation + + align:start position:0% +equation + + + align:start position:0% +equation +min-1 + 5 A2 in both + + align:start position:0% + + + + align:start position:0% + +cases so we can pick a value for V1 for + + align:start position:0% +cases so we can pick a value for V1 for + + + align:start position:0% +cases so we can pick a value for V1 for +A1 or + + align:start position:0% +A1 or + + + align:start position:0% +A1 or +A2 and write down a vector + + align:start position:0% +A2 and write down a vector + + + align:start position:0% +A2 and write down a vector +V2 in for example the form of A1 equals + + align:start position:0% +V2 in for example the form of A1 equals + + + align:start position:0% +V2 in for example the form of A1 equals +to Let's Pi A2 equals to 1 and we would + + align:start position:0% +to Let's Pi A2 equals to 1 and we would + + + align:start position:0% +to Let's Pi A2 equals to 1 and we would +have A1 equal to 5 for example again if + + align:start position:0% +have A1 equal to 5 for example again if + + + align:start position:0% +have A1 equal to 5 for example again if +you wanted an auton normal uh basis + + align:start position:0% +you wanted an auton normal uh basis + + + align:start position:0% +you wanted an auton normal uh basis +formed by your V1 V2 you would just + + align:start position:0% +formed by your V1 V2 you would just + + + align:start position:0% +formed by your V1 V2 you would just +normalize these two + + align:start position:0% +normalize these two + + + align:start position:0% +normalize these two +vectors so here basically we can then + + align:start position:0% +vectors so here basically we can then + + + align:start position:0% +vectors so here basically we can then +rewrite the + + align:start position:0% + + + + align:start position:0% + +solution to the original system + + align:start position:0% + + + + align:start position:0% + +as being a linear combinations + + align:start position:0% +as being a linear combinations + + + align:start position:0% +as being a linear combinations +of so I'm just going to write it in + + align:start position:0% +of so I'm just going to write it in + + + align:start position:0% +of so I'm just going to write it in +Vector + + align:start position:0% +Vector + + + align:start position:0% +Vector +form the first + + align:start position:0% +form the first + + + align:start position:0% +form the first +Vector one I keep it in V1 V2 that way + + align:start position:0% +Vector one I keep it in V1 V2 that way + + + align:start position:0% +Vector one I keep it in V1 V2 that way +you see it and then I'll go into the + + align:start position:0% + + + + align:start position:0% + +components we we have V1 + + align:start position:0% +components we we have V1 + + + align:start position:0% +components we we have V1 +exponential of the value of Lambda we + + align:start position:0% +exponential of the value of Lambda we + + + align:start position:0% +exponential of the value of Lambda we +found that corresponds to V1 so it would + + align:start position:0% +found that corresponds to V1 so it would + + + align:start position:0% +found that corresponds to V1 so it would +be 1. T and then + + align:start position:0% + + + + align:start position:0% + +V2 exponential of the Lambda value that + + align:start position:0% +V2 exponential of the Lambda value that + + + align:start position:0% +V2 exponential of the Lambda value that +corresponds to + + align:start position:0% +corresponds to + + + align:start position:0% +corresponds to +V2 okay and then uh basically we would + + align:start position:0% +V2 okay and then uh basically we would + + + align:start position:0% +V2 okay and then uh basically we would +just have constants of + + align:start position:0% +just have constants of + + + align:start position:0% +just have constants of +integration here and so the solution to + + align:start position:0% +integration here and so the solution to + + + align:start position:0% +integration here and so the solution to +this problem would be linear combination + + align:start position:0% +this problem would be linear combination + + + align:start position:0% +this problem would be linear combination +of the vectors form by our the bases of + + align:start position:0% +of the vectors form by our the bases of + + + align:start position:0% +of the vectors form by our the bases of +our aen vectors and multiply by the + + align:start position:0% +our aen vectors and multiply by the + + + align:start position:0% +our aen vectors and multiply by the +exponentials assign the values of the a + + align:start position:0% +exponentials assign the values of the a + + + align:start position:0% +exponentials assign the values of the a +values that we found when we looked for + + align:start position:0% +values that we found when we looked for + + + align:start position:0% +values that we found when we looked for +uh the Ang values of the Matrix of the + + align:start position:0% +uh the Ang values of the Matrix of the + + + align:start position:0% +uh the Ang values of the Matrix of the +system so here just note that like for + + align:start position:0% +system so here just note that like for + + + align:start position:0% +system so here just note that like for +the linear like for the 1D problem that + + align:start position:0% +the linear like for the 1D problem that + + + align:start position:0% +the linear like for the 1D problem that +we saw before we're building a solution + + align:start position:0% +we saw before we're building a solution + + + align:start position:0% +we saw before we're building a solution +based on linear combination of of lucky + + align:start position:0% +based on linear combination of of lucky + + + align:start position:0% +based on linear combination of of lucky +guesses that we used and in the one + + align:start position:0% +guesses that we used and in the one + + + align:start position:0% +guesses that we used and in the one +equation case we used a guess of e to + + align:start position:0% +equation case we used a guess of e to + + + align:start position:0% +equation case we used a guess of e to +lamb T in a + + align:start position:0% +lamb T in a + + + align:start position:0% +lamb T in a +1D here in this case we had a g a guess + + align:start position:0% +1D here in this case we had a g a guess + + + align:start position:0% +1D here in this case we had a g a guess +of a vector v in the form of LDA T that + + align:start position:0% +of a vector v in the form of LDA T that + + + align:start position:0% +of a vector v in the form of LDA T that +we used and then basically we just solve + + align:start position:0% +we used and then basically we just solve + + + align:start position:0% +we used and then basically we just solve +for the lendas and solve for the v's and + + align:start position:0% +for the lendas and solve for the v's and + + + align:start position:0% +for the lendas and solve for the v's and +did a linear combination of all those + + align:start position:0% +did a linear combination of all those + + + align:start position:0% +did a linear combination of all those +Solutions like we did before in the 1D + + align:start position:0% +Solutions like we did before in the 1D + + + align:start position:0% +Solutions like we did before in the 1D +case we softed out the lenda we had + + align:start position:0% +case we softed out the lenda we had + + + align:start position:0% +case we softed out the lenda we had +different values of lenda we did linear + + align:start position:0% +different values of lenda we did linear + + + align:start position:0% +different values of lenda we did linear +combinations of those exponentials so + + align:start position:0% +combinations of those exponentials so + + + align:start position:0% +combinations of those exponentials so +that ends this problem and here the key + + align:start position:0% +that ends this problem and here the key + + + align:start position:0% +that ends this problem and here the key +is just to go through the method of + + align:start position:0% +is just to go through the method of + + + align:start position:0% +is just to go through the method of +diagonalizing your Matrix basically it's + + align:start position:0% +diagonalizing your Matrix basically it's + + + align:start position:0% +diagonalizing your Matrix basically it's +finding the aen values and then + + align:start position:0% +finding the aen values and then + + + align:start position:0% +finding the aen values and then +Computing the aen vectors associated + + align:start position:0% +Computing the aen vectors associated + + + align:start position:0% +Computing the aen vectors associated +with that and writing your Solutions in + + align:start position:0% +with that and writing your Solutions in + + + align:start position:0% +with that and writing your Solutions in +terms of linear combination of the + + align:start position:0% +terms of linear combination of the + + + align:start position:0% +terms of linear combination of the +solution that you found \ No newline at end of file diff --git a/Yarwp7TNTL4.txt b/Yarwp7TNTL4.txt new file mode 100644 index 0000000000000000000000000000000000000000..f143b75511c0945c7d3d9137bfb106efdfa27cef --- /dev/null +++ b/Yarwp7TNTL4.txt @@ -0,0 +1,13344 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit MIT opencourseware + + align:start position:0% +of MIT courses visit MIT opencourseware + + + align:start position:0% +of MIT courses visit MIT opencourseware +at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu all right welcome to my last + + align:start position:0% +ocw.mit.edu all right welcome to my last + + + align:start position:0% +ocw.mit.edu all right welcome to my last +lecture for the semester um we finish + + align:start position:0% +lecture for the semester um we finish + + + align:start position:0% +lecture for the semester um we finish +our coverage of dynamic graphs and also + + align:start position:0% +our coverage of dynamic graphs and also + + + align:start position:0% +our coverage of dynamic graphs and also +our coverage of lower bounds we saw one + + align:start position:0% +our coverage of lower bounds we saw one + + + align:start position:0% +our coverage of lower bounds we saw one +big lower Bound in this class uh in the + + align:start position:0% +big lower Bound in this class uh in the + + + align:start position:0% +big lower Bound in this class uh in the +cell probe model you may recall cell + + align:start position:0% +cell probe model you may recall cell + + + align:start position:0% +cell probe model you may recall cell +probe model you just count how many + + align:start position:0% +probe model you just count how many + + + align:start position:0% +probe model you just count how many +cells of memory do you + + align:start position:0% +cells of memory do you + + + align:start position:0% +cells of memory do you +touch uh you want to prove a lower bound + + align:start position:0% +touch uh you want to prove a lower bound + + + align:start position:0% +touch uh you want to prove a lower bound +on that uh and today we're going to + + align:start position:0% +on that uh and today we're going to + + + align:start position:0% +on that uh and today we're going to +prove a cell prob lower bound on Dynamic + + align:start position:0% +prove a cell prob lower bound on Dynamic + + + align:start position:0% +prove a cell prob lower bound on Dynamic +connectivity uh which is a problem we've + + align:start position:0% +connectivity uh which is a problem we've + + + align:start position:0% +connectivity uh which is a problem we've +solved a few different times our lower + + align:start position:0% +solved a few different times our lower + + + align:start position:0% +solved a few different times our lower +bound will apply even when each of the + + align:start position:0% +bound will apply even when each of the + + + align:start position:0% +bound will apply even when each of the +connected compon components of your + + align:start position:0% +connected compon components of your + + + align:start position:0% +connected compon components of your +graph are just a + + align:start position:0% +graph are just a + + + align:start position:0% +graph are just a +path and so in particular they imply + + align:start position:0% +path and so in particular they imply + + + align:start position:0% +path and so in particular they imply +matching lower bounds for dynamic + + align:start position:0% + + + + align:start position:0% + +trees so here's the theorem we'll be + + align:start position:0% +trees so here's the theorem we'll be + + + align:start position:0% +trees so here's the theorem we'll be +proving today uh you want to + + align:start position:0% +proving today uh you want to + + + align:start position:0% +proving today uh you want to +insert and delete + + align:start position:0% + + + + align:start position:0% + +edges and do connectivity queries + + align:start position:0% + + + + align:start position:0% + +uh between Pairs of vertices + + align:start position:0% +uh between Pairs of vertices + + + align:start position:0% +uh between Pairs of vertices +VW I want to know is there a path from V + + align:start position:0% +VW I want to know is there a path from V + + + align:start position:0% +VW I want to know is there a path from V +to + + align:start position:0% +to + + + align:start position:0% +to +W just like we've been + + align:start position:0% +W just like we've been + + + align:start position:0% +W just like we've been +considering + + align:start position:0% +considering + + + align:start position:0% +considering +um these + + align:start position:0% + + + + align:start position:0% + +require Omega log n uh time per + + align:start position:0% + + + + align:start position:0% + +operation this is the max of update and + + align:start position:0% +operation this is the max of update and + + + align:start position:0% +operation this is the max of update and +query times has to be at least log n + + align:start position:0% +query times has to be at least log n + + + align:start position:0% +query times has to be at least log n +time proper + + align:start position:0% +time proper + + + align:start position:0% +time proper +operation uh + + align:start position:0% +operation uh + + + align:start position:0% +operation uh +even if the connected + + align:start position:0% + + + + align:start position:0% + +components are + + align:start position:0% + + + + align:start position:0% + +paths and even amortized and even + + align:start position:0% +paths and even amortized and even + + + align:start position:0% +paths and even amortized and even +randomized although I'm not going to + + align:start position:0% +randomized although I'm not going to + + + align:start position:0% +randomized although I'm not going to +prove all of these versions I I won't + + align:start position:0% +prove all of these versions I I won't + + + align:start position:0% +prove all of these versions I I won't +prove the amortized version I'm going to + + align:start position:0% +prove the amortized version I'm going to + + + align:start position:0% +prove the amortized version I'm going to +prove a worst case log and lower bound + + align:start position:0% +prove a worst case log and lower bound + + + align:start position:0% +prove a worst case log and lower bound +it's just a little more work to prove an + + align:start position:0% +it's just a little more work to prove an + + + align:start position:0% +it's just a little more work to prove an +amortized lower bound uh but same same + + align:start position:0% +amortized lower bound uh but same same + + + align:start position:0% +amortized lower bound uh but same same +principles and so that's going to + + align:start position:0% +principles and so that's going to + + + align:start position:0% +principles and so that's going to +be today is proving this theorem uh it's + + align:start position:0% +be today is proving this theorem uh it's + + + align:start position:0% +be today is proving this theorem uh it's +not short proof but it combines a bunch + + align:start position:0% +not short proof but it combines a bunch + + + align:start position:0% +not short proof but it combines a bunch +of relatively simple ideas uh and ends + + align:start position:0% +of relatively simple ideas uh and ends + + + align:start position:0% +of relatively simple ideas uh and ends +up being pretty clean overall piece by + + align:start position:0% +up being pretty clean overall piece by + + + align:start position:0% +up being pretty clean overall piece by +piece but there's just a bunch of pieces + + align:start position:0% +piece but there's just a bunch of pieces + + + align:start position:0% +piece but there's just a bunch of pieces +as we will get to key concept is an idea + + align:start position:0% +as we will get to key concept is an idea + + + align:start position:0% +as we will get to key concept is an idea +uh introduced in this paper which is uh + + align:start position:0% +uh introduced in this paper which is uh + + + align:start position:0% +uh introduced in this paper which is uh +to build build a balance binary tree + + align:start position:0% +to build build a balance binary tree + + + align:start position:0% +to build build a balance binary tree +over time over your access sequence and + + align:start position:0% +over time over your access sequence and + + + align:start position:0% +over time over your access sequence and +argue about different sub trees within + + align:start position:0% +argue about different sub trees within + + + align:start position:0% +argue about different sub trees within +that + + align:start position:0% +that + + + align:start position:0% +that +tree uh this is a + + align:start position:0% +tree uh this is a + + + align:start position:0% +tree uh this is a +paper uh that maybe came out of this + + align:start position:0% +paper uh that maybe came out of this + + + align:start position:0% +paper uh that maybe came out of this +class in some sense it was uh by Mii + + align:start position:0% +class in some sense it was uh by Mii + + + align:start position:0% +class in some sense it was uh by Mii +patashu and myself uh back when Mii was + + align:start position:0% +patashu and myself uh back when Mii was + + + align:start position:0% +patashu and myself uh back when Mii was +an undergrad I think he'd just taken + + align:start position:0% +an undergrad I think he'd just taken + + + align:start position:0% +an undergrad I think he'd just taken +this class uh but at that point the + + align:start position:0% +this class uh but at that point the + + + align:start position:0% +this class uh but at that point the +class didn't even cover Dynamic + + align:start position:0% +class didn't even cover Dynamic + + + align:start position:0% +class didn't even cover Dynamic +connectivity + + align:start position:0% +connectivity + + + align:start position:0% +connectivity +so uh uh and time here is cell + + align:start position:0% + + + + align:start position:0% + +probes so this is a very strong model uh + + align:start position:0% +probes so this is a very strong model uh + + + align:start position:0% +probes so this is a very strong model uh +it implies a lower bound on RAM it + + align:start position:0% +it implies a lower bound on RAM it + + + align:start position:0% +it implies a lower bound on RAM it +implies lower bound on pointer machine + + align:start position:0% +implies lower bound on pointer machine + + + align:start position:0% +implies lower bound on pointer machine +we know matching upper bounds for trees + + align:start position:0% +we know matching upper bounds for trees + + + align:start position:0% +we know matching upper bounds for trees +on a pointer machine uh link cut trees + + align:start position:0% +on a pointer machine uh link cut trees + + + align:start position:0% +on a pointer machine uh link cut trees +and Oiler tour trees it's kind of fun + + align:start position:0% +and Oiler tour trees it's kind of fun + + + align:start position:0% +and Oiler tour trees it's kind of fun +that this lower bound even applies to + + align:start position:0% +that this lower bound even applies to + + + align:start position:0% +that this lower bound even applies to +paths because most of the work in link + + align:start position:0% +paths because most of the work in link + + + align:start position:0% +paths because most of the work in link +cut trees is about decomposing your tree + + align:start position:0% +cut trees is about decomposing your tree + + + align:start position:0% +cut trees is about decomposing your tree +into paths and so what this is saying is + + align:start position:0% +into paths and so what this is saying is + + + align:start position:0% +into paths and so what this is saying is +even if that's done for you and you just + + align:start position:0% +even if that's done for you and you just + + + align:start position:0% +even if that's done for you and you just +need to be able to take paths and + + align:start position:0% +need to be able to take paths and + + + align:start position:0% +need to be able to take paths and +concatenate them together by adding + + align:start position:0% +concatenate them together by adding + + + align:start position:0% +concatenate them together by adding +edges uh then maintaining the find root + + align:start position:0% +edges uh then maintaining the find root + + + align:start position:0% +edges uh then maintaining the find root +property so that you can do connectivity + + align:start position:0% +property so that you can do connectivity + + + align:start position:0% +property so that you can do connectivity +queries even that requires log and time + + align:start position:0% +queries even that requires log and time + + + align:start position:0% +queries even that requires log and time +so the converting a tree into a path is + + align:start position:0% +so the converting a tree into a path is + + + align:start position:0% +so the converting a tree into a path is +basically free uh the hard part is + + align:start position:0% +basically free uh the hard part is + + + align:start position:0% +basically free uh the hard part is +maintaining the + + align:start position:0% +maintaining the + + + align:start position:0% +maintaining the +paths + + align:start position:0% +paths + + + align:start position:0% +paths +so let's prove the + + align:start position:0% +so let's prove the + + + align:start position:0% +so let's prove the +theorem uh the lower bound we get to + + align:start position:0% +theorem uh the lower bound we get to + + + align:start position:0% +theorem uh the lower bound we get to +choose what access sequence we think is + + align:start position:0% +choose what access sequence we think is + + + align:start position:0% +choose what access sequence we think is +bad and so we're going to uh come up + + align:start position:0% +bad and so we're going to uh come up + + + align:start position:0% +bad and so we're going to uh come up +with a particular style of + + align:start position:0% + + + + align:start position:0% + +graph which looks like the + + align:start position:0% + + + + align:start position:0% + +following graph is going to be the + + align:start position:0% +following graph is going to be the + + + align:start position:0% +following graph is going to be the +vertices are going to be a root n by + + align:start position:0% +vertices are going to be a root n by + + + align:start position:0% +vertices are going to be a root n by +root n + + align:start position:0% +root n + + + align:start position:0% +root n +grid + + align:start position:0% + + + + align:start position:0% + +and uh we're going to these guys are in + + align:start position:0% +and uh we're going to these guys are in + + + align:start position:0% +and uh we're going to these guys are in +what do I call them groups columns + + align:start position:0% +what do I call them groups columns + + + align:start position:0% +what do I call them groups columns +columns is good name these are columns + + align:start position:0% +columns is good name these are columns + + + align:start position:0% +columns is good name these are columns +of the + + align:start position:0% +of the + + + align:start position:0% +of the +Matrix or vertices and what I'd like to + + align:start position:0% +Matrix or vertices and what I'd like to + + + align:start position:0% +Matrix or vertices and what I'd like to +have is between consecutive columns I + + align:start position:0% +have is between consecutive columns I + + + align:start position:0% +have is between consecutive columns I +want to have a perfect matching between + + align:start position:0% +want to have a perfect matching between + + + align:start position:0% +want to have a perfect matching between +these + + align:start position:0% +these + + + align:start position:0% +these +vertices so could be I don't know this + + align:start position:0% +vertices so could be I don't know this + + + align:start position:0% +vertices so could be I don't know this +Edge this Edge this Edge and that edge + + align:start position:0% +Edge this Edge this Edge and that edge + + + align:start position:0% +Edge this Edge this Edge and that edge +and I also want a perfect matching + + align:start position:0% +and I also want a perfect matching + + + align:start position:0% +and I also want a perfect matching +between these two columns so maybe this + + align:start position:0% +between these two columns so maybe this + + + align:start position:0% +between these two columns so maybe this +one this + + align:start position:0% +one this + + + align:start position:0% +one this +one uh this one this + + align:start position:0% +one uh this one this + + + align:start position:0% +one uh this one this +one and I know you can have some boring + + align:start position:0% +one and I know you can have some boring + + + align:start position:0% +one and I know you can have some boring +things + + align:start position:0% +things + + + align:start position:0% +things +too something like that so between every + + align:start position:0% +too something like that so between every + + + align:start position:0% +too something like that so between every +pair of columns is a perfect + + align:start position:0% +pair of columns is a perfect + + + align:start position:0% +pair of columns is a perfect +matching meaning perfect + + align:start position:0% + + + + align:start position:0% + +pairing okay this of course results in a + + align:start position:0% +pairing okay this of course results in a + + + align:start position:0% +pairing okay this of course results in a +collection of paths square root of n + + align:start position:0% +collection of paths square root of n + + + align:start position:0% +collection of paths square root of n +paths you can start at any vertex on the + + align:start position:0% +paths you can start at any vertex on the + + + align:start position:0% +paths you can start at any vertex on the +left and you'll have a unique way to go + + align:start position:0% +left and you'll have a unique way to go + + + align:start position:0% +left and you'll have a unique way to go +to the right and so that's your that's + + align:start position:0% +to the right and so that's your that's + + + align:start position:0% +to the right and so that's your that's +path one this is path two this is path + + align:start position:0% +path one this is path two this is path + + + align:start position:0% +path one this is path two this is path +three and this is path + + align:start position:0% +three and this is path + + + align:start position:0% +three and this is path +four and so if I an interesting + + align:start position:0% +four and so if I an interesting + + + align:start position:0% +four and so if I an interesting +query well I mean interesting query is + + align:start position:0% +query well I mean interesting query is + + + align:start position:0% +query well I mean interesting query is +something like I want to know is this + + align:start position:0% +something like I want to know is this + + + align:start position:0% +something like I want to know is this +vertex connected to this one uh it's not + + align:start position:0% +vertex connected to this one uh it's not + + + align:start position:0% +vertex connected to this one uh it's not +so easy to figure it out because you + + align:start position:0% +so easy to figure it out because you + + + align:start position:0% +so easy to figure it out because you +have to sort of walk through this path + + align:start position:0% +have to sort of walk through this path + + + align:start position:0% +have to sort of walk through this path +to to figure that out we're going to + + align:start position:0% +to to figure that out we're going to + + + align:start position:0% +to to figure that out we're going to +think of each of these perfect matchings + + align:start position:0% +think of each of these perfect matchings + + + align:start position:0% +think of each of these perfect matchings +as defining a + + align:start position:0% +as defining a + + + align:start position:0% +as defining a +permutation on the vertices on the + + align:start position:0% +permutation on the vertices on the + + + align:start position:0% +permutation on the vertices on the +column really so you start with the + + align:start position:0% +column really so you start with the + + + align:start position:0% +column really so you start with the +identity permutation and then some + + align:start position:0% +identity permutation and then some + + + align:start position:0% +identity permutation and then some +things get swapped around that's Pi 1 + + align:start position:0% +things get swapped around that's Pi 1 + + + align:start position:0% +things get swapped around that's Pi 1 +some things get swapped around again + + align:start position:0% +some things get swapped around again + + + align:start position:0% +some things get swapped around again +that's Pi 2 some things get swapped + + align:start position:0% +that's Pi 2 some things get swapped + + + align:start position:0% +that's Pi 2 some things get swapped +around here that's Pi 3 and then this + + align:start position:0% +around here that's Pi 3 and then this + + + align:start position:0% +around here that's Pi 3 and then this +position would be uh Pi 3 of Pi 2 of Pi + + align:start position:0% +position would be uh Pi 3 of Pi 2 of Pi + + + align:start position:0% +position would be uh Pi 3 of Pi 2 of Pi + + align:start position:0% + + + align:start position:0% +of Vertex + + align:start position:0% +of Vertex + + + align:start position:0% +of Vertex +4 we call this Vertex + + align:start position:0% +4 we call this Vertex + + + align:start position:0% +4 we call this Vertex +4 or Row Row + + align:start position:0% +4 or Row Row + + + align:start position:0% +4 or Row Row +4 so in some sense we have to compose + + align:start position:0% +4 so in some sense we have to compose + + + align:start position:0% +4 so in some sense we have to compose +permutations I'll call this Pi 1 circle + + align:start position:0% +permutations I'll call this Pi 1 circle + + + align:start position:0% +permutations I'll call this Pi 1 circle +Pi 2 Circle + + align:start position:0% +Pi 2 Circle + + + align:start position:0% +Pi 2 Circle +pi3 uh of + + align:start position:0% +pi3 uh of + + + align:start position:0% +pi3 uh of +four and we're going to show basically + + align:start position:0% +four and we're going to show basically + + + align:start position:0% +four and we're going to show basically +composing permutations is tough when you + + align:start position:0% +composing permutations is tough when you + + + align:start position:0% +composing permutations is tough when you +can change those permutations + + align:start position:0% +can change those permutations + + + align:start position:0% +can change those permutations +dynamically so what we're going to do is + + align:start position:0% +dynamically so what we're going to do is + + + align:start position:0% +dynamically so what we're going to do is +a series of block + + align:start position:0% + + + + align:start position:0% + +operations which uh change or query + + align:start position:0% +operations which uh change or query + + + align:start position:0% +operations which uh change or query +entire + + align:start position:0% +entire + + + align:start position:0% +entire +permutations so here an + + align:start position:0% +permutations so here an + + + align:start position:0% +permutations so here an +update is going to be a whole bunch of + + align:start position:0% +update is going to be a whole bunch of + + + align:start position:0% +update is going to be a whole bunch of +uh insertions and deletions of + + align:start position:0% +uh insertions and deletions of + + + align:start position:0% +uh insertions and deletions of +edges basically what we want to do is + + align:start position:0% +edges basically what we want to do is + + + align:start position:0% +edges basically what we want to do is +set Pi I equal to + + align:start position:0% +set Pi I equal to + + + align:start position:0% +set Pi I equal to +Pi so that's what update of I comma Pi + + align:start position:0% +Pi so that's what update of I comma Pi + + + align:start position:0% +Pi so that's what update of I comma Pi +does it changes an entire perfect + + align:start position:0% +does it changes an entire perfect + + + align:start position:0% +does it changes an entire perfect +matching to be a specified permutation + + align:start position:0% +matching to be a specified permutation + + + align:start position:0% +matching to be a specified permutation +so how do you do that well you delete + + align:start position:0% +so how do you do that well you delete + + + align:start position:0% +so how do you do that well you delete +all the edges that are in the existing + + align:start position:0% +all the edges that are in the existing + + + align:start position:0% +all the edges that are in the existing +permutation and then you insert all the + + align:start position:0% +permutation and then you insert all the + + + align:start position:0% +permutation and then you insert all the +new edges so this can be done in + + align:start position:0% +new edges so this can be done in + + + align:start position:0% +new edges so this can be done in +uh square root of n Edge deletions and + + align:start position:0% + + + + align:start position:0% + +insertions so it's a bulk update of + + align:start position:0% +insertions so it's a bulk update of + + + align:start position:0% +insertions so it's a bulk update of +square of V operations and so this could + + align:start position:0% +square of V operations and so this could + + + align:start position:0% +square of V operations and so this could +only make our problem easier because + + align:start position:0% +only make our problem easier because + + + align:start position:0% +only make our problem easier because +we're given Square event updates that we + + align:start position:0% +we're given Square event updates that we + + + align:start position:0% +we're given Square event updates that we +all need to do at once uh so you could + + align:start position:0% +all need to do at once uh so you could + + + align:start position:0% +all need to do at once uh so you could +amortise over them you could do lots of + + align:start position:0% +amortise over them you could do lots of + + + align:start position:0% +amortise over them you could do lots of +different things uh but we're sure that + + align:start position:0% +different things uh but we're sure that + + + align:start position:0% +different things uh but we're sure that +won't won't + + align:start position:0% +won't won't + + + align:start position:0% +won't won't +help and then we have a + + align:start position:0% +help and then we have a + + + align:start position:0% +help and then we have a +query and the query is going to it's + + align:start position:0% +query and the query is going to it's + + + align:start position:0% +query and the query is going to it's +going to be a little bit + + align:start position:0% +going to be a little bit + + + align:start position:0% +going to be a little bit +weird and it's also going to make the + + align:start position:0% +weird and it's also going to make the + + + align:start position:0% +weird and it's also going to make the +proof a little bit more + + align:start position:0% +proof a little bit more + + + align:start position:0% +proof a little bit more +awkward but what it asks + + align:start position:0% +awkward but what it asks + + + align:start position:0% +awkward but what it asks +is if I look at the + + align:start position:0% +is if I look at the + + + align:start position:0% +is if I look at the +composition of Pi J from one up to + + align:start position:0% +composition of Pi J from one up to + + + align:start position:0% +composition of Pi J from one up to +I this is + + align:start position:0% +I this is + + + align:start position:0% +I this is +one to I I want to know is that + + align:start position:0% +one to I I want to know is that + + + align:start position:0% +one to I I want to know is that +composition equal to + + align:start position:0% +composition equal to + + + align:start position:0% +composition equal to +Pi yes or no this is what I'll call + + align:start position:0% +Pi yes or no this is what I'll call + + + align:start position:0% +Pi yes or no this is what I'll call +verify sum sum meaning composition uh + + align:start position:0% +verify sum sum meaning composition uh + + + align:start position:0% +verify sum sum meaning composition uh +but the sum terminology comes from a + + align:start position:0% +but the sum terminology comes from a + + + align:start position:0% +but the sum terminology comes from a +different problem which we won't talk + + align:start position:0% +different problem which we won't talk + + + align:start position:0% +different problem which we won't talk +about directly here called partial sums + + align:start position:0% +about directly here called partial sums + + + align:start position:0% +about directly here called partial sums +this partial sums is basically this + + align:start position:0% +this partial sums is basically this + + + align:start position:0% +this partial sums is basically this +problem you can change numbers in an + + align:start position:0% +problem you can change numbers in an + + + align:start position:0% +problem you can change numbers in an +array + + align:start position:0% +array + + + align:start position:0% +array +and you can compute the prefix sum from + + align:start position:0% +and you can compute the prefix sum from + + + align:start position:0% +and you can compute the prefix sum from +one up to I here we're not Computing it + + align:start position:0% +one up to I here we're not Computing it + + + align:start position:0% +one up to I here we're not Computing it +uh why are we not Computing it because + + align:start position:0% +uh why are we not Computing it because + + + align:start position:0% +uh why are we not Computing it because +actually figuring out what pi 3 of Pi 2 + + align:start position:0% +actually figuring out what pi 3 of Pi 2 + + + align:start position:0% +actually figuring out what pi 3 of Pi 2 +of Pi 1 is of something is tricky in + + align:start position:0% +of Pi 1 is of something is tricky in + + + align:start position:0% +of Pi 1 is of something is tricky in +this setting what we the operations + + align:start position:0% +this setting what we the operations + + + align:start position:0% +this setting what we the operations +we're given are given two vertices are + + align:start position:0% +we're given are given two vertices are + + + align:start position:0% +we're given are given two vertices are +they connected by a + + align:start position:0% +they connected by a + + + align:start position:0% +they connected by a +path uh so to figure out where the other + + align:start position:0% +path uh so to figure out where the other + + + align:start position:0% +path uh so to figure out where the other +end of this path that + + align:start position:0% +end of this path that + + + align:start position:0% +end of this path that +requires I mean it's hard to figure out + + align:start position:0% +requires I mean it's hard to figure out + + + align:start position:0% +requires I mean it's hard to figure out +where the other end is if I told you is + + align:start position:0% +where the other end is if I told you is + + + align:start position:0% +where the other end is if I told you is +it is it this one then I can answer that + + align:start position:0% +it is it this one then I can answer that + + + align:start position:0% +it is it this one then I can answer that +question with just a connectivity query + + align:start position:0% +question with just a connectivity query + + + align:start position:0% +question with just a connectivity query +so verify sum can be done with order + + align:start position:0% +so verify sum can be done with order + + + align:start position:0% +so verify sum can be done with order +square root of + + align:start position:0% +square root of + + + align:start position:0% +square root of +n uh connectivity + + align:start position:0% + + + + align:start position:0% + +queries whereas Computing the sum could + + align:start position:0% +queries whereas Computing the sum could + + + align:start position:0% +queries whereas Computing the sum could +not be as far as we know uh if I tell + + align:start position:0% +not be as far as we know uh if I tell + + + align:start position:0% +not be as far as we know uh if I tell +you what the what that composition is + + align:start position:0% +you what the what that composition is + + + align:start position:0% +you what the what that composition is +supposed to be I can check oh does four + + align:start position:0% +supposed to be I can check oh does four + + + align:start position:0% +supposed to be I can check oh does four +go to one yes or no does three go to + + align:start position:0% +go to one yes or no does three go to + + + align:start position:0% +go to one yes or no does three go to +three yes or no does two go to four yes + + align:start position:0% +three yes or no does two go to four yes + + + align:start position:0% +three yes or no does two go to four yes +or no does one go to two yes or no so + + align:start position:0% +or no does one go to two yes or no so + + + align:start position:0% +or no does one go to two yes or no so +with four queries I can check whether + + align:start position:0% +with four queries I can check whether + + + align:start position:0% +with four queries I can check whether +the permutation is what it + + align:start position:0% +the permutation is what it + + + align:start position:0% +the permutation is what it +is uh if any of those fail then I return + + align:start position:0% +is uh if any of those fail then I return + + + align:start position:0% +is uh if any of those fail then I return +no um so I mean the way this proceed is + + align:start position:0% +no um so I mean the way this proceed is + + + align:start position:0% +no um so I mean the way this proceed is +first we proved a lower bound on partial + + align:start position:0% +first we proved a lower bound on partial + + + align:start position:0% +first we proved a lower bound on partial +sums uh which is Computing this value + + align:start position:0% +sums uh which is Computing this value + + + align:start position:0% +sums uh which is Computing this value +when you're not not told what the answer + + align:start position:0% +when you're not not told what the answer + + + align:start position:0% +when you're not not told what the answer +is and then we extended that Pro and + + align:start position:0% +is and then we extended that Pro and + + + align:start position:0% +is and then we extended that Pro and +we'll we'll do such a proof here today + + align:start position:0% +we'll we'll do such a proof here today + + + align:start position:0% +we'll we'll do such a proof here today +first we're going to prove a lower bound + + align:start position:0% +first we're going to prove a lower bound + + + align:start position:0% +first we're going to prove a lower bound +on the sum operation which is Computing + + align:start position:0% +on the sum operation which is Computing + + + align:start position:0% +on the sum operation which is Computing +this value that's on our outline over + + align:start position:0% +this value that's on our outline over + + + align:start position:0% +this value that's on our outline over +here sum lower + + align:start position:0% +here sum lower + + + align:start position:0% +here sum lower +bounds uh and then we'll extend that + + align:start position:0% +bounds uh and then we'll extend that + + + align:start position:0% +bounds uh and then we'll extend that +make the argument a little bit more + + align:start position:0% +make the argument a little bit more + + + align:start position:0% +make the argument a little bit more +complicated then we'll get an actual + + align:start position:0% +complicated then we'll get an actual + + + align:start position:0% +complicated then we'll get an actual +connectivity lower bound a lower bound + + align:start position:0% +connectivity lower bound a lower bound + + + align:start position:0% +connectivity lower bound a lower bound +on verify + + align:start position:0% +on verify + + + align:start position:0% +on verify +sum okay but obviously if we can prove + + align:start position:0% +sum okay but obviously if we can prove + + + align:start position:0% +sum okay but obviously if we can prove +uh that these operations take a long + + align:start position:0% +uh that these operations take a long + + + align:start position:0% +uh that these operations take a long +time to do + + align:start position:0% +time to do + + + align:start position:0% +time to do +we can prove that these original + + align:start position:0% +we can prove that these original + + + align:start position:0% +we can prove that these original +operations take a long time to do + + align:start position:0% +operations take a long time to do + + + align:start position:0% +operations take a long time to do +so what we + + align:start position:0% + + + + align:start position:0% + +claim is that uh square root of n + + align:start position:0% + + + + align:start position:0% + +updates these uh block updates plus + + align:start position:0% +updates these uh block updates plus + + + align:start position:0% +updates these uh block updates plus +square root of n uh verify sum + + align:start position:0% + + + + align:start position:0% + +queries uh require + + align:start position:0% + + + + align:start position:0% + +root n * root n log + + align:start position:0% +root n * root n log + + + align:start position:0% +root n * root n log +n cell + + align:start position:0% + + + + align:start position:0% + +probes I guess this is the amortised + + align:start position:0% +probes I guess this is the amortised + + + align:start position:0% +probes I guess this is the amortised +claim so if I want to do Ruden updates + + align:start position:0% +claim so if I want to do Ruden updates + + + align:start position:0% +claim so if I want to do Ruden updates +and roten queries and I take rud * roten + + align:start position:0% +and roten queries and I take rud * roten + + + align:start position:0% +and roten queries and I take rud * roten +time log n funny way of writing n logn + + align:start position:0% +time log n funny way of writing n logn + + + align:start position:0% +time log n funny way of writing n logn +uh cell probes then uh if I divide + + align:start position:0% +uh cell probes then uh if I divide + + + align:start position:0% +uh cell probes then uh if I divide +through I want the amortized lower bound + + align:start position:0% +through I want the amortized lower bound + + + align:start position:0% +through I want the amortized lower bound +I I lose one of these root ends because + + align:start position:0% +I I lose one of these root ends because + + + align:start position:0% +I I lose one of these root ends because +I'm doing different operations I lose + + align:start position:0% +I'm doing different operations I lose + + + align:start position:0% +I'm doing different operations I lose +another root n because each of these + + align:start position:0% +another root n because each of these + + + align:start position:0% +another root n because each of these +updates corresponds to root n operations + + align:start position:0% +updates corresponds to root n operations + + + align:start position:0% +updates corresponds to root n operations +each of the verify sums corresponds to + + align:start position:0% +each of the verify sums corresponds to + + + align:start position:0% +each of the verify sums corresponds to +root n operations so overall per + + align:start position:0% +root n operations so overall per + + + align:start position:0% +root n operations so overall per +operation per original operation of edge + + align:start position:0% +operation per original operation of edge + + + align:start position:0% +operation per original operation of edge +deletion insertion or connectivity query + + align:start position:0% +deletion insertion or connectivity query + + + align:start position:0% +deletion insertion or connectivity query +I'm paying log n per operation so if I + + align:start position:0% +I'm paying log n per operation so if I + + + align:start position:0% +I'm paying log n per operation so if I +can prove this claim then I get this + + align:start position:0% +can prove this claim then I get this + + + align:start position:0% +can prove this claim then I get this +theorem all clear so now we've reduced + + align:start position:0% +theorem all clear so now we've reduced + + + align:start position:0% +theorem all clear so now we've reduced +the problem to these bulk operations + + align:start position:0% +the problem to these bulk operations + + + align:start position:0% +the problem to these bulk operations +we'll just be thinking about the bulk + + align:start position:0% +we'll just be thinking about the bulk + + + align:start position:0% +we'll just be thinking about the bulk +operations update verify some we won't + + align:start position:0% +operations update verify some we won't + + + align:start position:0% +operations update verify some we won't +think about Edge deletions insertions + + align:start position:0% +think about Edge deletions insertions + + + align:start position:0% +think about Edge deletions insertions +and connectivity queries + + align:start position:0% + + + + align:start position:0% + +anymore + + align:start position:0% + + + + align:start position:0% + +okay so this is just sort of the general + + align:start position:0% +okay so this is just sort of the general + + + align:start position:0% +okay so this is just sort of the general +setup of what the graph's going to look + + align:start position:0% +setup of what the graph's going to look + + + align:start position:0% +setup of what the graph's going to look +like and now I'm going to tell you what + + align:start position:0% +like and now I'm going to tell you what + + + align:start position:0% +like and now I'm going to tell you what +sequence of updates and verify sums + + align:start position:0% +sequence of updates and verify sums + + + align:start position:0% +sequence of updates and verify sums +we're actually going to do that are bad + + align:start position:0% +we're actually going to do that are bad + + + align:start position:0% +we're actually going to do that are bad +this is the bad access + + align:start position:0% + + + + align:start position:0% + +sequence and this is actually something + + align:start position:0% +sequence and this is actually something + + + align:start position:0% +sequence and this is actually something +we've seen before in lecture six I think + + align:start position:0% +we've seen before in lecture six I think + + + align:start position:0% +we've seen before in lecture six I think +the binary search tree + + align:start position:0% +the binary search tree + + + align:start position:0% +the binary search tree +stuff + + align:start position:0% + + + + align:start position:0% + +uh we're going to look at the bit + + align:start position:0% +uh we're going to look at the bit + + + align:start position:0% +uh we're going to look at the bit +reversal + + align:start position:0% + + + + align:start position:0% + +sequence + + align:start position:0% +sequence + + + align:start position:0% +sequence +so you may recall a bit reversal + + align:start position:0% +so you may recall a bit reversal + + + align:start position:0% +so you may recall a bit reversal +sequence you take binary + + align:start position:0% +sequence you take binary + + + align:start position:0% +sequence you take binary +numbers in + + align:start position:0% + + + + align:start position:0% + +order uh reverse the bits so this + + align:start position:0% +order uh reverse the bits so this + + + align:start position:0% +order uh reverse the bits so this +becomes 0 0 0 1 0 0 0 1 0 1 1 0 0 0 + + align:start position:0% +becomes 0 0 0 1 0 0 0 1 0 1 1 0 0 0 + + + align:start position:0% +becomes 0 0 0 1 0 0 0 1 0 1 1 0 0 0 +1 one 1 0 1 1 and 11 one1 so those are + + align:start position:0% +1 one 1 0 1 1 and 11 one1 so those are + + + align:start position:0% +1 one 1 0 1 1 and 11 one1 so those are +the + + align:start position:0% +the + + + align:start position:0% +the +Reversed + + align:start position:0% +Reversed + + + align:start position:0% +Reversed +strings and then you reinterpret those + + align:start position:0% +strings and then you reinterpret those + + + align:start position:0% +strings and then you reinterpret those +as regular numbers so this is 0 4 2 + + align:start position:0% + + + + align:start position:0% + +6 and then it should be the same thing + + align:start position:0% +6 and then it should be the same thing + + + align:start position:0% +6 and then it should be the same thing +but the odd version so we'll have 1 5 3 + + align:start position:0% + + + + align:start position:0% + +7 okay we uh I claimed I think probably + + align:start position:0% +7 okay we uh I claimed I think probably + + + align:start position:0% +7 okay we uh I claimed I think probably +didn't prove that this bit reversal + + align:start position:0% +didn't prove that this bit reversal + + + align:start position:0% +didn't prove that this bit reversal +sequence has a high Wilbur lower bound + + align:start position:0% +sequence has a high Wilbur lower bound + + + align:start position:0% +sequence has a high Wilbur lower bound +uh and so any binary search tree + + align:start position:0% +uh and so any binary search tree + + + align:start position:0% +uh and so any binary search tree +accessing items in this order requires + + align:start position:0% +accessing items in this order requires + + + align:start position:0% +accessing items in this order requires +log and per operation and we want log in + + align:start position:0% +log and per operation and we want log in + + + align:start position:0% +log and per operation and we want log in +prop operation here so it seems like a + + align:start position:0% +prop operation here so it seems like a + + + align:start position:0% +prop operation here so it seems like a +good choice why not so we're going to + + align:start position:0% +good choice why not so we're going to + + + align:start position:0% +good choice why not so we're going to +follow this access sequence and sorry + + align:start position:0% +follow this access sequence and sorry + + + align:start position:0% +follow this access sequence and sorry +I've changed notation here we're going + + align:start position:0% +I've changed notation here we're going + + + align:start position:0% +I've changed notation here we're going +to number the permutations from zero to + + align:start position:0% +to number the permutations from zero to + + + align:start position:0% +to number the permutations from zero to +root n minus one + + align:start position:0% +root n minus one + + + align:start position:0% +root n minus one +now and assume root N is a power of two + + align:start position:0% +now and assume root N is a power of two + + + align:start position:0% +now and assume root N is a power of two +so the bit reversal sequence is well + + align:start position:0% +so the bit reversal sequence is well + + + align:start position:0% +so the bit reversal sequence is well +defined and then we are going to do two + + align:start position:0% + + + + align:start position:0% + +things for each such I we're going to do + + align:start position:0% +things for each such I we're going to do + + + align:start position:0% +things for each such I we're going to do +a verify sum + + align:start position:0% + + + + align:start position:0% + +operation + + align:start position:0% + + + + align:start position:0% + +uh actually maybe it is starting at one + + align:start position:0% +uh actually maybe it is starting at one + + + align:start position:0% +uh actually maybe it is starting at one +I don't know doesn't + + align:start position:0% +I don't know doesn't + + + align:start position:0% +I don't know doesn't +matter and then we'll do an + + align:start position:0% + + + + align:start position:0% + +update + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so let's see this Pi random is just a + + align:start position:0% +so let's see this Pi random is just a + + + align:start position:0% +so let's see this Pi random is just a +uniform random permutation it's computed + + align:start position:0% +uniform random permutation it's computed + + + align:start position:0% +uniform random permutation it's computed +fresh every time so we're just + + align:start position:0% +fresh every time so we're just + + + align:start position:0% +fresh every time so we're just +randomizing Pi + + align:start position:0% +randomizing Pi + + + align:start position:0% +randomizing Pi +I in this operation before we do that + + align:start position:0% +I in this operation before we do that + + + align:start position:0% +I in this operation before we do that +we're checking that this the sum the + + align:start position:0% +we're checking that this the sum the + + + align:start position:0% +we're checking that this the sum the +composition of all the permutations up + + align:start position:0% +composition of all the permutations up + + + align:start position:0% +composition of all the permutations up +to position I is what it is so this is + + align:start position:0% +to position I is what it is so this is + + + align:start position:0% +to position I is what it is so this is +the actual value here and we're + + align:start position:0% +the actual value here and we're + + + align:start position:0% +the actual value here and we're +verifying uh that that is the indeed the + + align:start position:0% +verifying uh that that is the indeed the + + + align:start position:0% +verifying uh that that is the indeed the +sum so this will always return + + align:start position:0% +sum so this will always return + + + align:start position:0% +sum so this will always return +Yes but data structure has to be correct + + align:start position:0% +Yes but data structure has to be correct + + + align:start position:0% +Yes but data structure has to be correct +so it needs to really verify that that + + align:start position:0% +so it needs to really verify that that + + + align:start position:0% +so it needs to really verify that that +is the case uh there's the threat that + + align:start position:0% +is the case uh there's the threat that + + + align:start position:0% +is the case uh there's the threat that +maybe we gave the wrong answer here and + + align:start position:0% +maybe we gave the wrong answer here and + + + align:start position:0% +maybe we gave the wrong answer here and +it needs to double check that that is + + align:start position:0% +it needs to double check that that is + + + align:start position:0% +it needs to double check that that is +indeed the right answer it may seem a + + align:start position:0% +indeed the right answer it may seem a + + + align:start position:0% +indeed the right answer it may seem a +little weird but we'll see why it works + + align:start position:0% +little weird but we'll see why it works + + + align:start position:0% +little weird but we'll see why it works +so this is the bad access sequence just + + align:start position:0% +so this is the bad access sequence just + + + align:start position:0% +so this is the bad access sequence just +do a query do an update in this weird + + align:start position:0% +do a query do an update in this weird + + + align:start position:0% +do a query do an update in this weird +order in + + align:start position:0% +order in + + + align:start position:0% +order in +I okay and big idea is + + align:start position:0% +I okay and big idea is + + + align:start position:0% +I okay and big idea is +to uh build a nice balanced binary + + align:start position:0% +to uh build a nice balanced binary + + + align:start position:0% +to uh build a nice balanced binary +tree over + + align:start position:0% + + + + align:start position:0% + +time so we have on the ground here 0 4 2 + + align:start position:0% +time so we have on the ground here 0 4 2 + + + align:start position:0% +time so we have on the ground here 0 4 2 +6 1 5 3 7 and when I write five mean + + align:start position:0% +6 1 5 3 7 and when I write five mean + + + align:start position:0% +6 1 5 3 7 and when I write five mean +verify sum of five and update + + align:start position:0% +verify sum of five and update + + + align:start position:0% +verify sum of five and update +permutation five and then we can build a + + align:start position:0% +permutation five and then we can build a + + + align:start position:0% +permutation five and then we can build a +binary tree on + + align:start position:0% + + + + align:start position:0% + +that and for each node in this tree we + + align:start position:0% +that and for each node in this tree we + + + align:start position:0% +that and for each node in this tree we +have the notion of a left sub tree and + + align:start position:0% +have the notion of a left sub tree and + + + align:start position:0% +have the notion of a left sub tree and +we have the notion of a right sub tree + + align:start position:0% +we have the notion of a right sub tree + + + align:start position:0% +we have the notion of a right sub tree +and cool thing about bit reversal + + align:start position:0% +and cool thing about bit reversal + + + align:start position:0% +and cool thing about bit reversal +sequence is kind of this nice + + align:start position:0% +sequence is kind of this nice + + + align:start position:0% +sequence is kind of this nice +self-similarity if you look at the left + + align:start position:0% +self-similarity if you look at the left + + + align:start position:0% +self-similarity if you look at the left +sub tree of any node and the right sub + + align:start position:0% +sub tree of any node and the right sub + + + align:start position:0% +sub tree of any node and the right sub +tree of any node those items inter leave + + align:start position:0% +tree of any node those items inter leave + + + align:start position:0% +tree of any node those items inter leave +if you look at the sorted order it's one + + align:start position:0% +if you look at the sorted order it's one + + + align:start position:0% +if you look at the sorted order it's one +on the left three on the right five on + + align:start position:0% +on the left three on the right five on + + + align:start position:0% +on the left three on the right five on +the left seven on the right they always + + align:start position:0% +the left seven on the right they always + + + align:start position:0% +the left seven on the right they always +perfectly interl because this thing is + + align:start position:0% +perfectly interl because this thing is + + + align:start position:0% +perfectly interl because this thing is +designed to interl at every possible + + align:start position:0% +designed to interl at every possible + + + align:start position:0% +designed to interl at every possible +level so that's the fact we're going to + + align:start position:0% +level so that's the fact we're going to + + + align:start position:0% +level so that's the fact we're going to +use we're going to analyze each node + + align:start position:0% +use we're going to analyze each node + + + align:start position:0% +use we're going to analyze each node +separately and talk about uh what + + align:start position:0% +separately and talk about uh what + + + align:start position:0% +separately and talk about uh what +information has to be carried from the + + align:start position:0% +information has to be carried from the + + + align:start position:0% +information has to be carried from the +left sub tree to the right sub Tree in + + align:start position:0% +left sub tree to the right sub Tree in + + + align:start position:0% +left sub tree to the right sub Tree in +particular we're interested on the in + + align:start position:0% +particular we're interested on the in + + + align:start position:0% +particular we're interested on the in +the updates being done on the left sub + + align:start position:0% +the updates being done on the left sub + + + align:start position:0% +the updates being done on the left sub +tree cuz we change Pi 1 we change Pi 5 + + align:start position:0% +tree cuz we change Pi 1 we change Pi 5 + + + align:start position:0% +tree cuz we change Pi 1 we change Pi 5 +and the quer is being done on the right + + align:start position:0% +and the quer is being done on the right + + + align:start position:0% +and the quer is being done on the right +subt tree because here we query uh three + + align:start position:0% +subt tree because here we query uh three + + + align:start position:0% +subt tree because here we query uh three +we query 7even when we query three that + + align:start position:0% +we query 7even when we query three that + + + align:start position:0% +we query 7even when we query three that +queries everything all the permutations + + align:start position:0% +queries everything all the permutations + + + align:start position:0% +queries everything all the permutations +up to three it's the composition of all + + align:start position:0% +up to three it's the composition of all + + + align:start position:0% +up to three it's the composition of all +permutations up to three so in + + align:start position:0% +permutations up to three so in + + + align:start position:0% +permutations up to three so in +particular it involves one so the claim + + align:start position:0% +particular it involves one so the claim + + + align:start position:0% +particular it involves one so the claim +is going to be that the permutation that + + align:start position:0% +is going to be that the permutation that + + + align:start position:0% +is going to be that the permutation that +we set in one has to be carried over to + + align:start position:0% +we set in one has to be carried over to + + + align:start position:0% +we set in one has to be carried over to +this query and similarly five a changing + + align:start position:0% +this query and similarly five a changing + + + align:start position:0% +this query and similarly five a changing +permutation five will affect the query + + align:start position:0% +permutation five will affect the query + + + align:start position:0% +permutation five will affect the query +for seven also query the update for one + + align:start position:0% +for seven also query the update for one + + + align:start position:0% +for seven also query the update for one +will affect the query for + + align:start position:0% +will affect the query for + + + align:start position:0% +will affect the query for +seven so uh we need to formalize that a + + align:start position:0% +seven so uh we need to formalize that a + + + align:start position:0% +seven so uh we need to formalize that a +little + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +bit so here is the + + align:start position:0% + + + + align:start position:0% + +claim for every node in the + + align:start position:0% + + + + align:start position:0% + +tree uh say it has L + + align:start position:0% + + + + align:start position:0% + +leaves in its sub + + align:start position:0% + + + + align:start position:0% + +tree + + align:start position:0% +tree + + + align:start position:0% +tree +uh this should be a comma this should be + + align:start position:0% +uh this should be a comma this should be + + + align:start position:0% +uh this should be a comma this should be +a colon + + align:start position:0% +a colon + + + align:start position:0% +a colon +whatever here's we + + align:start position:0% +whatever here's we + + + align:start position:0% +whatever here's we +say during the right sub tree of V of + + align:start position:0% +say during the right sub tree of V of + + + align:start position:0% +say during the right sub tree of V of +course the right sub tree corresponds to + + align:start position:0% +course the right sub tree corresponds to + + + align:start position:0% +course the right sub tree corresponds to +an interval of time so we're talking + + align:start position:0% +an interval of time so we're talking + + + align:start position:0% +an interval of time so we're talking +talking about those operations done + + align:start position:0% +talking about those operations done + + + align:start position:0% +talking about those operations done +during the right sub tree of + + align:start position:0% + + + + align:start position:0% + +V claim is we must + + align:start position:0% +V claim is we must + + + align:start position:0% +V claim is we must +do Omega L root n cell + + align:start position:0% + + + + align:start position:0% + +probes sorry expected cell + + align:start position:0% + + + + align:start position:0% + +probes we are using some Randomness here + + align:start position:0% +probes we are using some Randomness here + + + align:start position:0% +probes we are using some Randomness here +right we said we're going to update each + + align:start position:0% +right we said we're going to update each + + + align:start position:0% +right we said we're going to update each +permutation to a random value so we can + + align:start position:0% +permutation to a random value so we can + + + align:start position:0% +permutation to a random value so we can +only make claims about the expected + + align:start position:0% + + + + align:start position:0% + +performance uh fine but that's actually + + align:start position:0% +performance uh fine but that's actually + + + align:start position:0% +performance uh fine but that's actually +a stronger thing it implies a lower + + align:start position:0% +a stronger thing it implies a lower + + + align:start position:0% +a stronger thing it implies a lower +bound even for randomized algorithms if + + align:start position:0% +bound even for randomized algorithms if + + + align:start position:0% +bound even for randomized algorithms if +you can randomize your input + + align:start position:0% +you can randomize your input + + + align:start position:0% +you can randomize your input +Set uh and + + align:start position:0% +Set uh and + + + align:start position:0% +Set uh and +then not just any cell probes but + + align:start position:0% +then not just any cell probes but + + + align:start position:0% +then not just any cell probes but +they're cell probes that read cells last + + align:start position:0% +they're cell probes that read cells last + + + align:start position:0% +they're cell probes that read cells last +written during the left + + align:start position:0% +written during the left + + + align:start position:0% +written during the left +subtree + + align:start position:0% + + + + align:start position:0% + +okay so this is what I + + align:start position:0% +okay so this is what I + + + align:start position:0% +okay so this is what I +was saying at a high level before we're + + align:start position:0% +was saying at a high level before we're + + + align:start position:0% +was saying at a high level before we're +looking at reads over + + align:start position:0% +looking at reads over + + + align:start position:0% +looking at reads over +here to cells that are written over here + + align:start position:0% +here to cells that are written over here + + + align:start position:0% +here to cells that are written over here +because we claim the updates over here + + align:start position:0% +because we claim the updates over here + + + align:start position:0% +because we claim the updates over here +have to store some information that is I + + align:start position:0% +have to store some information that is I + + + align:start position:0% +have to store some information that is I +mean whatever the updates that happen + + align:start position:0% +mean whatever the updates that happen + + + align:start position:0% +mean whatever the updates that happen +over here influence the queries that + + align:start position:0% +over here influence the queries that + + + align:start position:0% +over here influence the queries that +happen over here so these queries have + + align:start position:0% +happen over here so these queries have + + + align:start position:0% +happen over here so these queries have +to read the data that was written over + + align:start position:0% +to read the data that was written over + + + align:start position:0% +to read the data that was written over +here and specifically we're claiming at + + align:start position:0% +here and specifically we're claiming at + + + align:start position:0% +here and specifically we're claiming at +least L root n cell probes have to be + + align:start position:0% +least L root n cell probes have to be + + + align:start position:0% +least L root n cell probes have to be +read over here uh from cells that were + + align:start position:0% +read over here uh from cells that were + + + align:start position:0% +read over here uh from cells that were +written that were basically just written + + align:start position:0% +written that were basically just written + + + align:start position:0% +written that were basically just written +in the left sub tree if we could prove + + align:start position:0% +in the left sub tree if we could prove + + + align:start position:0% +in the left sub tree if we could prove +this then we get our other claim this + + align:start position:0% +this then we get our other claim this + + + align:start position:0% +this then we get our other claim this +one over here that root n updates and + + align:start position:0% +one over here that root n updates and + + + align:start position:0% +one over here that root n updates and +root n verify sums require this much + + align:start position:0% +root n verify sums require this much + + + align:start position:0% +root n verify sums require this much +time uh the difference + + align:start position:0% +time uh the difference + + + align:start position:0% +time uh the difference +is well here we have an L for an L leaf + + align:start position:0% +is well here we have an L for an L leaf + + + align:start position:0% +is well here we have an L for an L leaf +tree and so uh what I'd like to do is + + align:start position:0% +tree and so uh what I'd like to do is + + + align:start position:0% +tree and so uh what I'd like to do is +sum this lower bound over every node in + + align:start position:0% +sum this lower bound over every node in + + + align:start position:0% +sum this lower bound over every node in +the tree need to check that that is + + align:start position:0% +the tree need to check that that is + + + align:start position:0% +the tree need to check that that is +valid to do so let's do + + align:start position:0% + + + + align:start position:0% + +that okay for for every node V we + + align:start position:0% +that okay for for every node V we + + + align:start position:0% +that okay for for every node V we +claiming there's a certain number of + + align:start position:0% +claiming there's a certain number of + + + align:start position:0% +claiming there's a certain number of +reads that happen over here that + + align:start position:0% +reads that happen over here that + + + align:start position:0% +reads that happen over here that +corresponder writes over here uh but you + + align:start position:0% +corresponder writes over here uh but you + + + align:start position:0% +corresponder writes over here uh but you +know uh let's say you look at the parent + + align:start position:0% +know uh let's say you look at the parent + + + align:start position:0% +know uh let's say you look at the parent +of e which is over here this thing is + + align:start position:0% +of e which is over here this thing is + + + align:start position:0% +of e which is over here this thing is +also in the right sub tree and we're + + align:start position:0% +also in the right sub tree and we're + + + align:start position:0% +also in the right sub tree and we're +claiming there's some number of reads on + + align:start position:0% +claiming there's some number of reads on + + + align:start position:0% +claiming there's some number of reads on +the right sub tree that read things that + + align:start position:0% +the right sub tree that read things that + + + align:start position:0% +the right sub tree that read things that +written over on the left the worry would + + align:start position:0% +written over on the left the worry would + + + align:start position:0% +written over on the left the worry would +be that the reads we counted here we + + align:start position:0% +be that the reads we counted here we + + + align:start position:0% +be that the reads we counted here we +also count at the next level up we don't + + align:start position:0% +also count at the next level up we don't + + + align:start position:0% +also count at the next level up we don't +want to double count in our lower bounds + + align:start position:0% +want to double count in our lower bounds + + + align:start position:0% +want to double count in our lower bounds +if we're able to sum them up we can't be + + align:start position:0% +if we're able to sum them up we can't be + + + align:start position:0% +if we're able to sum them up we can't be +double counting uh but the claim is + + align:start position:0% +double counting uh but the claim is + + + align:start position:0% +double counting uh but the claim is +we're not double counting because if you + + align:start position:0% +we're not double counting because if you + + + align:start position:0% +we're not double counting because if you +look at any particular any read so you + + align:start position:0% +look at any particular any read so you + + + align:start position:0% +look at any particular any read so you +here's time and suppose you do a read + + align:start position:0% +here's time and suppose you do a read + + + align:start position:0% +here's time and suppose you do a read +here you're reading a cell that was + + align:start position:0% +here you're reading a cell that was + + + align:start position:0% +here you're reading a cell that was +written sometime in the past if it was + + align:start position:0% +written sometime in the past if it was + + + align:start position:0% +written sometime in the past if it was +never written it's not very interesting + + align:start position:0% +never written it's not very interesting + + + align:start position:0% +never written it's not very interesting +read communicates no information so + + align:start position:0% +read communicates no information so + + + align:start position:0% +read communicates no information so +there's some right in the past that uh + + align:start position:0% +there's some right in the past that uh + + + align:start position:0% +there's some right in the past that uh +changed the the cell is just red and + + align:start position:0% +changed the the cell is just red and + + + align:start position:0% +changed the the cell is just red and +we're going to count this read at a + + align:start position:0% +we're going to count this read at a + + + align:start position:0% +we're going to count this read at a +particular node namely the LCA of those + + align:start position:0% +particular node namely the LCA of those + + + align:start position:0% +particular node namely the LCA of those +two times so if you look at the LCA of + + align:start position:0% +two times so if you look at the LCA of + + + align:start position:0% +two times so if you look at the LCA of +the times the reads and the wrs that is + + align:start position:0% +the times the reads and the wrs that is + + + align:start position:0% +the times the reads and the wrs that is +the single node we'll think about that + + align:start position:0% +the single node we'll think about that + + + align:start position:0% +the single node we'll think about that +read uh that happened in the right sub + + align:start position:0% +read uh that happened in the right sub + + + align:start position:0% +read uh that happened in the right sub +tree that was written in the left sub + + align:start position:0% +tree that was written in the left sub + + + align:start position:0% +tree that was written in the left sub +tree okay so no double + + align:start position:0% + + + + align:start position:0% + +counting + + align:start position:0% +counting + + + align:start position:0% +counting +because + + align:start position:0% +because + + + align:start position:0% +because +uh we only count at the + + align:start position:0% + + + + align:start position:0% + +LCA uh the other thing we need to be + + align:start position:0% +LCA uh the other thing we need to be + + + align:start position:0% +LCA uh the other thing we need to be +able to do is because this is an + + align:start position:0% +able to do is because this is an + + + align:start position:0% +able to do is because this is an +expected lower bound we need linearity + + align:start position:0% +expected lower bound we need linearity + + + align:start position:0% +expected lower bound we need linearity +of expectation but expectation is indeed + + align:start position:0% +of expectation but expectation is indeed + + + align:start position:0% +of expectation but expectation is indeed +linear so we're we're all set + + align:start position:0% + + + + align:start position:0% + +okay so all this left is a little bit of + + align:start position:0% +okay so all this left is a little bit of + + + align:start position:0% +okay so all this left is a little bit of +combinatorics if we take L root n where + + align:start position:0% +combinatorics if we take L root n where + + + align:start position:0% +combinatorics if we take L root n where +L is the size of the sub tree below a + + align:start position:0% +L is the size of the sub tree below a + + + align:start position:0% +L is the size of the sub tree below a +given node uh and we sum that up over + + align:start position:0% +given node uh and we sum that up over + + + align:start position:0% +given node uh and we sum that up over +all nodes and it's a balanced binary + + align:start position:0% +all nodes and it's a balanced binary + + + align:start position:0% +all nodes and it's a balanced binary +search tree uh or a balanced binary tree + + align:start position:0% +search tree uh or a balanced binary tree + + + align:start position:0% +search tree uh or a balanced binary tree +I should say not a search tree uh what + + align:start position:0% +I should say not a search tree uh what + + + align:start position:0% +I should say not a search tree uh what +do we get well every leaf appears in log + + align:start position:0% +do we get well every leaf appears in log + + + align:start position:0% +do we get well every leaf appears in log +and sub trees so we get the total size + + align:start position:0% +and sub trees so we get the total size + + + align:start position:0% +and sub trees so we get the total size +of the tree time log n for this and we + + align:start position:0% +of the tree time log n for this and we + + + align:start position:0% +of the tree time log n for this and we +get another root n over here the total + + align:start position:0% +get another root n over here the total + + + align:start position:0% +get another root n over here the total +size of the sub tree of the tree is root + + align:start position:0% +size of the sub tree of the tree is root + + + align:start position:0% +size of the sub tree of the tree is root +n so we get + + align:start position:0% +n so we get + + + align:start position:0% +n so we get +uh this root n log n that's when you sum + + align:start position:0% +uh this root n log n that's when you sum + + + align:start position:0% +uh this root n log n that's when you sum +up the L part then everything gets + + align:start position:0% +up the L part then everything gets + + + align:start position:0% +up the L part then everything gets +multiplied by root + + align:start position:0% +multiplied by root + + + align:start position:0% +multiplied by root +n and that becomes our lower bound and + + align:start position:0% +n and that becomes our lower bound and + + + align:start position:0% +n and that becomes our lower bound and +that's exactly what we need over + + align:start position:0% +that's exactly what we need over + + + align:start position:0% +that's exactly what we need over +here so now uh this claim is + + align:start position:0% +here so now uh this claim is + + + align:start position:0% +here so now uh this claim is +done uh maybe I should do a check mark + + align:start position:0% +done uh maybe I should do a check mark + + + align:start position:0% +done uh maybe I should do a check mark +provided we can prove this claim so now + + align:start position:0% +provided we can prove this claim so now + + + align:start position:0% +provided we can prove this claim so now +our goal is to prove this thing and now + + align:start position:0% +our goal is to prove this thing and now + + + align:start position:0% +our goal is to prove this thing and now +we're in a sort of more local world + + align:start position:0% +we're in a sort of more local world + + + align:start position:0% +we're in a sort of more local world +looking at a single node counting reads + + align:start position:0% +looking at a single node counting reads + + + align:start position:0% +looking at a single node counting reads +over here the correspondent writes over + + align:start position:0% +over here the correspondent writes over + + + align:start position:0% +over here the correspondent writes over +there and then you just add up those + + align:start position:0% +there and then you just add up those + + + align:start position:0% +there and then you just add up those +lower bounds you get what you want so + + align:start position:0% +lower bounds you get what you want so + + + align:start position:0% +lower bounds you get what you want so +this is where the log comes from because + + align:start position:0% +this is where the log comes from because + + + align:start position:0% +this is where the log comes from because +it's a balanced tree and there's log end + + align:start position:0% +it's a balanced tree and there's log end + + + align:start position:0% +it's a balanced tree and there's log end +levels in a balance tree that's where + + align:start position:0% +levels in a balance tree that's where + + + align:start position:0% +levels in a balance tree that's where +we're getting our lower bound the root + + align:start position:0% +we're getting our lower bound the root + + + align:start position:0% +we're getting our lower bound the root +ends are just you know keeping track of + + align:start position:0% +ends are just you know keeping track of + + + align:start position:0% +ends are just you know keeping track of +the size of the things we're + + align:start position:0% + + + + align:start position:0% + +manipulating all right + + align:start position:0% + + + + align:start position:0% + +so it remains to prove this + + align:start position:0% + + + + align:start position:0% + +claim we prove that claim we get that + + align:start position:0% +claim we prove that claim we get that + + + align:start position:0% +claim we prove that claim we get that +claim and then we get this + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +theorem + + align:start position:0% + + + + align:start position:0% + +so proof of + + align:start position:0% + + + + align:start position:0% + +claim uh we're going to do an + + align:start position:0% +claim uh we're going to do an + + + align:start position:0% +claim uh we're going to do an +information theoretic argument uh so let + + align:start position:0% +information theoretic argument uh so let + + + align:start position:0% +information theoretic argument uh so let +me set it up it's again it's making this + + align:start position:0% +me set it up it's again it's making this + + + align:start position:0% +me set it up it's again it's making this +claim that I said before that the + + align:start position:0% +claim that I said before that the + + + align:start position:0% +claim that I said before that the +permutations that get written over here + + align:start position:0% +permutations that get written over here + + + align:start position:0% +permutations that get written over here +somehow have to be communicated to the + + align:start position:0% +somehow have to be communicated to the + + + align:start position:0% +somehow have to be communicated to the +queries over here because uh they matter + + align:start position:0% +queries over here because uh they matter + + + align:start position:0% +queries over here because uh they matter +because the the permutations that get + + align:start position:0% +because the the permutations that get + + + align:start position:0% +because the the permutations that get +set over here in change the answers to + + align:start position:0% +set over here in change the answers to + + + align:start position:0% +set over here in change the answers to +all the queries over here because they + + align:start position:0% +all the queries over here because they + + + align:start position:0% +all the queries over here because they +because of the interleaving between left + + align:start position:0% +because of the interleaving between left + + + align:start position:0% +because of the interleaving between left +and right so how we going to formalize + + align:start position:0% +and right so how we going to formalize + + + align:start position:0% +and right so how we going to formalize +that + + align:start position:0% + + + + align:start position:0% + +well left sub + + align:start position:0% +well left sub + + + align:start position:0% +well left sub +tree uh does L over2 + + align:start position:0% + + + + align:start position:0% + +updates uh uh with L over2 random + + align:start position:0% + + + + align:start position:0% + +permutations uniform random permutations + + align:start position:0% +permutations uniform random permutations + + + align:start position:0% +permutations uniform random permutations +because every node does an + + align:start position:0% +because every node does an + + + align:start position:0% +because every node does an +update um and so the information + + align:start position:0% +update um and so the information + + + align:start position:0% +update um and so the information +theoretic idea is that if we were to + + align:start position:0% +theoretic idea is that if we were to + + + align:start position:0% +theoretic idea is that if we were to +somehow encode those + + align:start position:0% + + + + align:start position:0% + +permutations that + + align:start position:0% +permutations that + + + align:start position:0% +permutations that +encoding um must + + align:start position:0% +encoding um must + + + align:start position:0% +encoding um must +use Omega L log l l no sorry that's not + + align:start position:0% +use Omega L log l l no sorry that's not + + + align:start position:0% +use Omega L log l l no sorry that's not +right off by some root n factors here L + + align:start position:0% +right off by some root n factors here L + + + align:start position:0% +right off by some root n factors here L +root n log + + align:start position:0% +root n log + + + align:start position:0% +root n log +n okay each permutation must take root n + + align:start position:0% +n okay each permutation must take root n + + + align:start position:0% +n okay each permutation must take root n +log root n Bits to encode uh if you have + + align:start position:0% +log root n Bits to encode uh if you have + + + align:start position:0% +log root n Bits to encode uh if you have +a random permutation expected number of + + align:start position:0% +a random permutation expected number of + + + align:start position:0% +a random permutation expected number of +bits effect with very high probability + + align:start position:0% +bits effect with very high probability + + + align:start position:0% +bits effect with very high probability +almost every permutation requires root n + + align:start position:0% +almost every permutation requires root n + + + align:start position:0% +almost every permutation requires root n +log root n Bits I'm not going to worry + + align:start position:0% +log root n Bits I'm not going to worry + + + align:start position:0% +log root n Bits I'm not going to worry +about constant factors put an Omega here + + align:start position:0% +about constant factors put an Omega here + + + align:start position:0% +about constant factors put an Omega here +so the root n turns into an n and then + + align:start position:0% +so the root n turns into an n and then + + + align:start position:0% +so the root n turns into an n and then +we've got L over2 of them so again + + align:start position:0% +we've got L over2 of them so again + + + align:start position:0% +we've got L over2 of them so again +ignoring constant factors that's L root + + align:start position:0% +ignoring constant factors that's L root + + + align:start position:0% +ignoring constant factors that's L root +n log n + + align:start position:0% + + + + align:start position:0% + +Bits okay this is just information + + align:start position:0% +Bits okay this is just information + + + align:start position:0% +Bits okay this is just information +theoretic + + align:start position:0% +theoretic + + + align:start position:0% +theoretic +fact uh or kagor Theory fact and + + align:start position:0% +fact uh or kagor Theory fact and + + + align:start position:0% +fact uh or kagor Theory fact and +uh once we know that the idea is let's + + align:start position:0% +uh once we know that the idea is let's + + + align:start position:0% +uh once we know that the idea is let's +find an encoding that's better than this + + align:start position:0% +find an encoding that's better than this + + + align:start position:0% +find an encoding that's better than this +and get a + + align:start position:0% +and get a + + + align:start position:0% +and get a +contradiction of course we shouldn't get + + align:start position:0% +contradiction of course we shouldn't get + + + align:start position:0% +contradiction of course we shouldn't get +a contradiction unless this claim is + + align:start position:0% +a contradiction unless this claim is + + + align:start position:0% +a contradiction unless this claim is +false so either this claim is true and + + align:start position:0% +false so either this claim is true and + + + align:start position:0% +false so either this claim is true and +we're happy but if somehow there were + + align:start position:0% +we're happy but if somehow there were + + + align:start position:0% +we're happy but if somehow there were +not enough cell reads on the right that + + align:start position:0% +not enough cell reads on the right that + + + align:start position:0% +not enough cell reads on the right that +did things that were written on the left + + align:start position:0% +did things that were written on the left + + + align:start position:0% +did things that were written on the left +then we will from that get a smaller + + align:start position:0% +then we will from that get a smaller + + + align:start position:0% +then we will from that get a smaller +encoding of the uh update permutations + + align:start position:0% +encoding of the uh update permutations + + + align:start position:0% +encoding of the uh update permutations +that happen on the left if we could + + align:start position:0% +that happen on the left if we could + + + align:start position:0% +that happen on the left if we could +somehow do that then we get a + + align:start position:0% +somehow do that then we get a + + + align:start position:0% +somehow do that then we get a +contradiction and therefore conclude uh + + align:start position:0% +contradiction and therefore conclude uh + + + align:start position:0% +contradiction and therefore conclude uh +the claim is in fact + + align:start position:0% +the claim is in fact + + + align:start position:0% +the claim is in fact +true + + align:start position:0% +true + + + align:start position:0% +true +so + + align:start position:0% + + + + align:start position:0% + +uh so if the claim + + align:start position:0% +uh so if the claim + + + align:start position:0% +uh so if the claim +fails uh we'll find a smaller + + align:start position:0% + + + + align:start position:0% + +encoding which will give us a + + align:start position:0% + + + + align:start position:0% + +contradiction all + + align:start position:0% +contradiction all + + + align:start position:0% +contradiction all +right + + align:start position:0% +right + + + align:start position:0% +right +so + + align:start position:0% +so + + + align:start position:0% +so +set up this problem a little bit + + align:start position:0% +set up this problem a little bit + + + align:start position:0% +set up this problem a little bit +more uh I'm going + + align:start position:0% +more uh I'm going + + + align:start position:0% +more uh I'm going +to because we're really just interested + + align:start position:0% +to because we're really just interested + + + align:start position:0% +to because we're really just interested +in this sub tree V stuff on the left + + align:start position:0% +in this sub tree V stuff on the left + + + align:start position:0% +in this sub tree V stuff on the left +stuff on the right but this of course + + align:start position:0% +stuff on the right but this of course + + + align:start position:0% +stuff on the right but this of course +lives in a much bigger tree there's + + align:start position:0% +lives in a much bigger tree there's + + + align:start position:0% +lives in a much bigger tree there's +stuff that happens over here this I will + + align:start position:0% +stuff that happens over here this I will + + + align:start position:0% +stuff that happens over here this I will +call the past I'm just going to assum + + align:start position:0% +call the past I'm just going to assum + + + align:start position:0% +call the past I'm just going to assum +assume we know everything about the + + align:start position:0% +assume we know everything about the + + + align:start position:0% +assume we know everything about the +past everything to the left of V + + align:start position:0% +past everything to the left of V + + + align:start position:0% +past everything to the left of V +subtree we know we can assume that we + + align:start position:0% +subtree we know we can assume that we + + + align:start position:0% +subtree we know we can assume that we +know when I say we know + + align:start position:0% +know when I say we know + + + align:start position:0% +know when I say we know +uh what what do we know we know all the + + align:start position:0% +uh what what do we know we know all the + + + align:start position:0% +uh what what do we know we know all the +updates we know all the queries that + + align:start position:0% +updates we know all the queries that + + + align:start position:0% +updates we know all the queries that +happen and we know at this moment in + + align:start position:0% +happen and we know at this moment in + + + align:start position:0% +happen and we know at this moment in +particular what is the state of the data + + align:start position:0% +particular what is the state of the data + + + align:start position:0% +particular what is the state of the data +structure because this claim has nothing + + align:start position:0% +structure because this claim has nothing + + + align:start position:0% +structure because this claim has nothing +to do with this stuff it's all about + + align:start position:0% +to do with this stuff it's all about + + + align:start position:0% +to do with this stuff it's all about +reads here that correspond to writes + + align:start position:0% +reads here that correspond to writes + + + align:start position:0% +reads here that correspond to writes +here so we can just assume we know + + align:start position:0% +here so we can just assume we know + + + align:start position:0% +here so we can just assume we know +everything up to this point in our + + align:start position:0% +everything up to this point in our + + + align:start position:0% +everything up to this point in our +encoding this is a key point one way to + + align:start position:0% +encoding this is a key point one way to + + + align:start position:0% +encoding this is a key point one way to +say this in a probabilistic sense is + + align:start position:0% +say this in a probabilistic sense is + + + align:start position:0% +say this in a probabilistic sense is +we're conditioning on what this what + + align:start position:0% +we're conditioning on what this what + + + align:start position:0% +we're conditioning on what this what +happened over here on the left what + + align:start position:0% +happened over here on the left what + + + align:start position:0% +happened over here on the left what +updates happened and if we can prove + + align:start position:0% +updates happened and if we can prove + + + align:start position:0% +updates happened and if we can prove +that whatever we need to happen here + + align:start position:0% +that whatever we need to happen here + + + align:start position:0% +that whatever we need to happen here +holds no matter what the condition is + + align:start position:0% +holds no matter what the condition is + + + align:start position:0% +holds no matter what the condition is +then it will hold overall so that's how + + align:start position:0% +then it will hold overall so that's how + + + align:start position:0% +then it will hold overall so that's how +we uh that's probabilistic justification + + align:start position:0% +we uh that's probabilistic justification + + + align:start position:0% +we uh that's probabilistic justification +for why we can assume we know the + + align:start position:0% +for why we can assume we know the + + + align:start position:0% +for why we can assume we know the +past okay uh so then our + + align:start position:0% + + + + align:start position:0% + +goal is + + align:start position:0% +goal is + + + align:start position:0% +goal is +to + + align:start position:0% +to + + + align:start position:0% +to +encode this is a little bit different + + align:start position:0% +encode this is a little bit different + + + align:start position:0% +encode this is a little bit different +from this + + align:start position:0% + + + + align:start position:0% + +goal + + align:start position:0% + + + + align:start position:0% + +okay what we really want to do is encode + + align:start position:0% +okay what we really want to do is encode + + + align:start position:0% +okay what we really want to do is encode +the update permutations on the + + align:start position:0% +the update permutations on the + + + align:start position:0% +the update permutations on the +left that's a little awkward to think + + align:start position:0% +left that's a little awkward to think + + + align:start position:0% +left that's a little awkward to think +about because this is a claim about how + + align:start position:0% +about because this is a claim about how + + + align:start position:0% +about because this is a claim about how +many probes happen on the right so + + align:start position:0% +many probes happen on the right so + + + align:start position:0% +many probes happen on the right so +instead what we're going to do is encode + + align:start position:0% +instead what we're going to do is encode + + + align:start position:0% +instead what we're going to do is encode +the query permutations on the right so + + align:start position:0% +the query permutations on the right so + + + align:start position:0% +the query permutations on the right so +there are updates over here that's what + + align:start position:0% +there are updates over here that's what + + + align:start position:0% +there are updates over here that's what +we want to encode but we're instead + + align:start position:0% +we want to encode but we're instead + + + align:start position:0% +we want to encode but we're instead +going to encode the queries over here I + + align:start position:0% +going to encode the queries over here I + + + align:start position:0% +going to encode the queries over here I +claim if you know what the results of + + align:start position:0% +claim if you know what the results of + + + align:start position:0% +claim if you know what the results of +the queries were over here then uh you + + align:start position:0% +the queries were over here then uh you + + + align:start position:0% +the queries were over here then uh you +know what the updates were over + + align:start position:0% +know what the updates were over + + + align:start position:0% +know what the updates were over +there basically because of this + + align:start position:0% +there basically because of this + + + align:start position:0% +there basically because of this +interleaving property so I can write + + align:start position:0% +interleaving property so I can write + + + align:start position:0% +interleaving property so I can write +that down a little more + + align:start position:0% + + + + align:start position:0% + +formally so if we look at time here over + + align:start position:0% +formally so if we look at time here over + + + align:start position:0% +formally so if we look at time here over +let's say this is V's + + align:start position:0% + + + + align:start position:0% + +subtree then what we have are sequence + + align:start position:0% +subtree then what we have are sequence + + + align:start position:0% +subtree then what we have are sequence +of + + align:start position:0% +of + + + align:start position:0% +of +updates and a sequence of + + align:start position:0% + + + + align:start position:0% + +queries these are + + align:start position:0% + + + + align:start position:0% + +queries and these are + + align:start position:0% +queries and these are + + + align:start position:0% +queries and these are +Updates this is what the sequence looks + + align:start position:0% +Updates this is what the sequence looks + + + align:start position:0% +Updates this is what the sequence looks +like uh sorry this is V sub this is the + + align:start position:0% +like uh sorry this is V sub this is the + + + align:start position:0% +like uh sorry this is V sub this is the +pi eyes I should + + align:start position:0% + + + + align:start position:0% + +say I mean these operations are all + + align:start position:0% +say I mean these operations are all + + + align:start position:0% +say I mean these operations are all +happen during time but now I'm sorting + + align:start position:0% +happen during time but now I'm sorting + + + align:start position:0% +happen during time but now I'm sorting +by + + align:start position:0% +by + + + align:start position:0% +by +I a little + + align:start position:0% +I a little + + + align:start position:0% +I a little +confusing there's two orders to think + + align:start position:0% +confusing there's two orders to think + + + align:start position:0% +confusing there's two orders to think +about right there's the the sequence + + align:start position:0% +about right there's the the sequence + + + align:start position:0% +about right there's the the sequence +over time we're now looking at such a + + align:start position:0% +over time we're now looking at such a + + + align:start position:0% +over time we're now looking at such a +left sub tree where we do say 15 and + + align:start position:0% +left sub tree where we do say 15 and + + + align:start position:0% +left sub tree where we do say 15 and +37 what that means so you're imagining + + align:start position:0% +37 what that means so you're imagining + + + align:start position:0% +37 what that means so you're imagining +here this is one this is five this is + + align:start position:0% +here this is one this is five this is + + + align:start position:0% +here this is one this is five this is +three this is seven here we've sorted by + + align:start position:0% +three this is seven here we've sorted by + + + align:start position:0% +three this is seven here we've sorted by +the the value written down there sorting + + align:start position:0% +the the value written down there sorting + + + align:start position:0% +the the value written down there sorting +by the I the pi I that you're changing + + align:start position:0% +by the I the pi I that you're changing + + + align:start position:0% +by the I the pi I that you're changing +or querying and so all the red things + + align:start position:0% +or querying and so all the red things + + + align:start position:0% +or querying and so all the red things +are on in the right sub tree of + + align:start position:0% + + + + align:start position:0% + +v and all the + + align:start position:0% +v and all the + + + align:start position:0% +v and all the +updates are in the left sub tree of + + align:start position:0% + + + + align:start position:0% + +V this is the interleaving property that + + align:start position:0% +V this is the interleaving property that + + + align:start position:0% +V this is the interleaving property that +I mentioned + + align:start position:0% +I mentioned + + + align:start position:0% +I mentioned +earlier uh so I claim that if I encode + + align:start position:0% +earlier uh so I claim that if I encode + + + align:start position:0% +earlier uh so I claim that if I encode +the results of the queries namely I + + align:start position:0% +the results of the queries namely I + + + align:start position:0% +the results of the queries namely I +encode these + + align:start position:0% +encode these + + + align:start position:0% +encode these +permutations these are like summary + + align:start position:0% +permutations these are like summary + + + align:start position:0% +permutations these are like summary +partial sums these are prefix sums of + + align:start position:0% +partial sums these are prefix sums of + + + align:start position:0% +partial sums these are prefix sums of +the permutation lists then I can figure + + align:start position:0% +the permutation lists then I can figure + + + align:start position:0% +the permutation lists then I can figure +out what the updates were why because if + + align:start position:0% +out what the updates were why because if + + + align:start position:0% +out what the updates were why because if +I if I figure out what this query what + + align:start position:0% +I if I figure out what this query what + + + align:start position:0% +I if I figure out what this query what +its permutation is that's the sum of all + + align:start position:0% +its permutation is that's the sum of all + + + align:start position:0% +its permutation is that's the sum of all +of these + + align:start position:0% +of these + + + align:start position:0% +of these +permutations now only one of them + + align:start position:0% +permutations now only one of them + + + align:start position:0% +permutations now only one of them +changed in the left sub tree the rest + + align:start position:0% +changed in the left sub tree the rest + + + align:start position:0% +changed in the left sub tree the rest +all are in the past they were all set + + align:start position:0% +all are in the past they were all set + + + align:start position:0% +all are in the past they were all set +before this time over here and I know + + align:start position:0% +before this time over here and I know + + + align:start position:0% +before this time over here and I know +everything about the past I'm assuming + + align:start position:0% +everything about the past I'm assuming + + + align:start position:0% +everything about the past I'm assuming +so most of these I already know the one + + align:start position:0% +so most of these I already know the one + + + align:start position:0% +so most of these I already know the one +thing I don't know is this one but I + + align:start position:0% +thing I don't know is this one but I + + + align:start position:0% +thing I don't know is this one but I +claim if I know this + + align:start position:0% +claim if I know this + + + align:start position:0% +claim if I know this +sum and I know uh and I know all the + + align:start position:0% +sum and I know uh and I know all the + + + align:start position:0% +sum and I know uh and I know all the +others then I can figure out what this + + align:start position:0% +others then I can figure out what this + + + align:start position:0% +others then I can figure out what this +one is right it's slightly awkward to do + + align:start position:0% +one is right it's slightly awkward to do + + + align:start position:0% +one is right it's slightly awkward to do +if I give you this uh I give you the sum + + align:start position:0% +if I give you this uh I give you the sum + + + align:start position:0% +if I give you this uh I give you the sum +of Pi J from J equal 0 I or + + align:start position:0% +of Pi J from J equal 0 I or + + + align:start position:0% +of Pi J from J equal 0 I or +something uh I've got + + align:start position:0% +something uh I've got + + + align:start position:0% +something uh I've got +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +to I want to strip away all these strip + + align:start position:0% +to I want to strip away all these strip + + + align:start position:0% +to I want to strip away all these strip +away all these so I'm going to multiply + + align:start position:0% +away all these so I'm going to multiply + + + align:start position:0% +away all these so I'm going to multiply +by some sum of Pi J inverses over here + + align:start position:0% +by some sum of Pi J inverses over here + + + align:start position:0% +by some sum of Pi J inverses over here +and multiply by su Pi J or I say + + align:start position:0% +and multiply by su Pi J or I say + + + align:start position:0% +and multiply by su Pi J or I say +multiply I mean + + align:start position:0% +multiply I mean + + + align:start position:0% +multiply I mean +compose some PJ inverses here maybe + + align:start position:0% +compose some PJ inverses here maybe + + + align:start position:0% +compose some PJ inverses here maybe +let's not worry about the exact indices + + align:start position:0% +let's not worry about the exact indices + + + align:start position:0% +let's not worry about the exact indices +here but the point is this is all in the + + align:start position:0% +here but the point is this is all in the + + + align:start position:0% +here but the point is this is all in the +past + + align:start position:0% +past + + + align:start position:0% +past +and this is all in the past so I know + + align:start position:0% +and this is all in the past so I know + + + align:start position:0% +and this is all in the past so I know +all these Pi JS I know they're + + align:start position:0% +all these Pi JS I know they're + + + align:start position:0% +all these Pi JS I know they're +inverses so if I have this total sum and + + align:start position:0% +inverses so if I have this total sum and + + + align:start position:0% +inverses so if I have this total sum and +I right multiply with these inverses + + align:start position:0% +I right multiply with these inverses + + + align:start position:0% +I right multiply with these inverses +left multiply with these inverses I get + + align:start position:0% +left multiply with these inverses I get + + + align:start position:0% +left multiply with these inverses I get +the one that I want this gives me uh + + align:start position:0% +the one that I want this gives me uh + + + align:start position:0% +the one that I want this gives me uh +some + + align:start position:0% +some + + + align:start position:0% +some +particular uh Pi + + align:start position:0% +particular uh Pi + + + align:start position:0% +particular uh Pi +K if I set the indices + + align:start position:0% + + + + align:start position:0% + +right okay so if I know this query I + + align:start position:0% +right okay so if I know this query I + + + align:start position:0% +right okay so if I know this query I +figure out what this update is now once + + align:start position:0% +figure out what this update is now once + + + align:start position:0% +figure out what this update is now once +I know what this update is and I know + + align:start position:0% +I know what this update is and I know + + + align:start position:0% +I know what this update is and I know +this query then in this sum I know + + align:start position:0% +this query then in this sum I know + + + align:start position:0% +this query then in this sum I know +everything except this one thing and so + + align:start position:0% +everything except this one thing and so + + + align:start position:0% +everything except this one thing and so +uh using the same trick I can figure out + + align:start position:0% +uh using the same trick I can figure out + + + align:start position:0% +uh using the same trick I can figure out +what this update is that so now I know + + align:start position:0% +what this update is that so now I know + + + align:start position:0% +what this update is that so now I know +the first two updates if I then know the + + align:start position:0% +the first two updates if I then know the + + + align:start position:0% +the first two updates if I then know the +answer to this query I can figure out + + align:start position:0% +answer to this query I can figure out + + + align:start position:0% +answer to this query I can figure out +what this update is if I know the answer + + align:start position:0% +what this update is if I know the answer + + + align:start position:0% +what this update is if I know the answer +to this query I can figure out this + + align:start position:0% +to this query I can figure out this + + + align:start position:0% +to this query I can figure out this +update because they're perfectly + + align:start position:0% +update because they're perfectly + + + align:start position:0% +update because they're perfectly +interleaved I only need to reconstruct + + align:start position:0% +interleaved I only need to reconstruct + + + align:start position:0% +interleaved I only need to reconstruct +One update at a time so if I'm given if + + align:start position:0% +One update at a time so if I'm given if + + + align:start position:0% +One update at a time so if I'm given if +I've somehow encoded all of the queries + + align:start position:0% +I've somehow encoded all of the queries + + + align:start position:0% +I've somehow encoded all of the queries +results all of these prefix sums and I'm + + align:start position:0% +results all of these prefix sums and I'm + + + align:start position:0% +results all of these prefix sums and I'm +given the past then I can reconstruct + + align:start position:0% +given the past then I can reconstruct + + + align:start position:0% +given the past then I can reconstruct +what all the updates were so that's + + align:start position:0% +what all the updates were so that's + + + align:start position:0% +what all the updates were so that's +basically saying these two are the same + + align:start position:0% +basically saying these two are the same + + + align:start position:0% +basically saying these two are the same +issue if I can encode the verified sums + + align:start position:0% +issue if I can encode the verified sums + + + align:start position:0% +issue if I can encode the verified sums +in the right subtree using less than L + + align:start position:0% +in the right subtree using less than L + + + align:start position:0% +in the right subtree using less than L +root n log n Bits then I'll get a + + align:start position:0% +root n log n Bits then I'll get a + + + align:start position:0% +root n log n Bits then I'll get a +contradiction because it implies from + + align:start position:0% +contradiction because it implies from + + + align:start position:0% +contradiction because it implies from +that same encoding you can also decode + + align:start position:0% +that same encoding you can also decode + + + align:start position:0% +that same encoding you can also decode +the update permutations in the left sub + + align:start position:0% +the update permutations in the left sub + + + align:start position:0% +the update permutations in the left sub +tree so that's our + + align:start position:0% + + + + align:start position:0% + +goal okay uh + + align:start position:0% + + + + align:start position:0% + +so we'd like to prove this for verify + + align:start position:0% +so we'd like to prove this for verify + + + align:start position:0% +so we'd like to prove this for verify +sum but the first thing I'm going to do + + align:start position:0% +sum but the first thing I'm going to do + + + align:start position:0% +sum but the first thing I'm going to do +is consider an easier problem which is + + align:start position:0% +is consider an easier problem which is + + + align:start position:0% +is consider an easier problem which is +sum so suppose basically this was not an + + align:start position:0% +sum so suppose basically this was not an + + + align:start position:0% +sum so suppose basically this was not an +input to the query suppose the query was + + align:start position:0% +input to the query suppose the query was + + + align:start position:0% +input to the query suppose the query was +what is the sum of + + align:start position:0% +what is the sum of + + + align:start position:0% +what is the sum of +I it's like this I just want to I want + + align:start position:0% +I it's like this I just want to I want + + + align:start position:0% +I it's like this I just want to I want +this is the partial sum problem and + + align:start position:0% +this is the partial sum problem and + + + align:start position:0% +this is the partial sum problem and +given an index I I want to know what is + + align:start position:0% +given an index I I want to know what is + + + align:start position:0% +given an index I I want to know what is +the permutation from PI 0 up to Pi I now + + align:start position:0% +the permutation from PI 0 up to Pi I now + + + align:start position:0% +the permutation from PI 0 up to Pi I now +that is not that doesn't correspond to + + align:start position:0% +that is not that doesn't correspond to + + + align:start position:0% +that is not that doesn't correspond to +Dynamic connectivity it's a new problem + + align:start position:0% +Dynamic connectivity it's a new problem + + + align:start position:0% +Dynamic connectivity it's a new problem +we'll first prove a lower Bound for that + + align:start position:0% +we'll first prove a lower Bound for that + + + align:start position:0% +we'll first prove a lower Bound for that +problem and then we'll put the verify + + align:start position:0% +problem and then we'll put the verify + + + align:start position:0% +problem and then we'll put the verify +word back + + align:start position:0% +word back + + + align:start position:0% +word back +in okay that's uh we're now + + align:start position:0% +in okay that's uh we're now + + + align:start position:0% +in okay that's uh we're now +here some lower bound and where should I + + align:start position:0% +here some lower bound and where should I + + + align:start position:0% +here some lower bound and where should I +go different so this is a lower bound on + + align:start position:0% +go different so this is a lower bound on + + + align:start position:0% +go different so this is a lower bound on +the operation sum as opposed to here + + align:start position:0% +the operation sum as opposed to here + + + align:start position:0% +the operation sum as opposed to here +where we were adding up lower bounds + + align:start position:0% +where we were adding up lower bounds + + + align:start position:0% +where we were adding up lower bounds +sorry for the conflation of terms + + align:start position:0% +sorry for the conflation of terms + + + align:start position:0% +sorry for the conflation of terms +uh let's + + align:start position:0% +uh let's + + + align:start position:0% +uh let's +go up + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +here so I'll call this a + + align:start position:0% + + + + align:start position:0% + +warm-up + + align:start position:0% + + + + align:start position:0% + +suppose the query is sum of I which is + + align:start position:0% +suppose the query is sum of I which is + + + align:start position:0% +suppose the query is sum of I which is +supposed to give + + align:start position:0% +supposed to give + + + align:start position:0% +supposed to give +you this prefix sum of Pi JS again sum + + align:start position:0% +you this prefix sum of Pi JS again sum + + + align:start position:0% +you this prefix sum of Pi JS again sum +means + + align:start position:0% +means + + + align:start position:0% +means +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +composition uh + + align:start position:0% + + + + align:start position:0% + +so this is going to be relatively easy + + align:start position:0% +so this is going to be relatively easy + + + align:start position:0% +so this is going to be relatively easy +to prove but it's not the problem we + + align:start position:0% +to prove but it's not the problem we + + + align:start position:0% +to prove but it's not the problem we +actually want to solve we'll use it to + + align:start position:0% +actually want to solve we'll use it to + + + align:start position:0% +actually want to solve we'll use it to +then solve the the real problem and this + + align:start position:0% +then solve the the real problem and this + + + align:start position:0% +then solve the the real problem and this +is the order in which we actually solve + + align:start position:0% +is the order in which we actually solve + + + align:start position:0% +is the order in which we actually solve +things first prove a lower bound on + + align:start position:0% +things first prove a lower bound on + + + align:start position:0% +things first prove a lower bound on +partial sums uh okay so let me give you + + align:start position:0% +partial sums uh okay so let me give you + + + align:start position:0% +partial sums uh okay so let me give you +some + + align:start position:0% +some + + + align:start position:0% +some +notation so we can really get at uh this + + align:start position:0% +notation so we can really get at uh this + + + align:start position:0% +notation so we can really get at uh this +claim reading on the + + align:start position:0% +claim reading on the + + + align:start position:0% +claim reading on the +right writing on the left so let R be + + align:start position:0% +right writing on the left so let R be + + + align:start position:0% +right writing on the left so let R be +all the cells that are read + + align:start position:0% +all the cells that are read + + + align:start position:0% +all the cells that are read +during the right sub tree which is an + + align:start position:0% +during the right sub tree which is an + + + align:start position:0% +during the right sub tree which is an +interval of + + align:start position:0% + + + + align:start position:0% + +time and let + + align:start position:0% +time and let + + + align:start position:0% +time and let +W be the cells written in the left sub + + align:start position:0% + + + + align:start position:0% + +tree okay so what we're talking about + + align:start position:0% +tree okay so what we're talking about + + + align:start position:0% +tree okay so what we're talking about +over here is that R intersect W those + + align:start position:0% +over here is that R intersect W those + + + align:start position:0% +over here is that R intersect W those +are cells that are read during the right + + align:start position:0% +are cells that are read during the right + + + align:start position:0% +are cells that are read during the right +C Tre that were at some point written + + align:start position:0% +C Tre that were at some point written + + + align:start position:0% +C Tre that were at some point written +during the left sub tree uh should be + + align:start position:0% +during the left sub tree uh should be + + + align:start position:0% +during the left sub tree uh should be +large so we want to prove a lower bound + + align:start position:0% +large so we want to prove a lower bound + + + align:start position:0% +large so we want to prove a lower bound +on the size of R intersect w + + align:start position:0% + + + + align:start position:0% + +so if the lower bound doesn't hold that + + align:start position:0% +so if the lower bound doesn't hold that + + + align:start position:0% +so if the lower bound doesn't hold that +means that R intersect W is relatively + + align:start position:0% +means that R intersect W is relatively + + + align:start position:0% +means that R intersect W is relatively +small so imagine a situation where R + + align:start position:0% +small so imagine a situation where R + + + align:start position:0% +small so imagine a situation where R +intersect W is very small there's not + + align:start position:0% +intersect W is very small there's not + + + align:start position:0% +intersect W is very small there's not +very much information passed on the left + + align:start position:0% +very much information passed on the left + + + align:start position:0% +very much information passed on the left +sub tree to the right sub tree if R + + align:start position:0% +sub tree to the right sub tree if R + + + align:start position:0% +sub tree to the right sub tree if R +intersect W is small then presumably I + + align:start position:0% +intersect W is small then presumably I + + + align:start position:0% +intersect W is small then presumably I +can afford to write it down I can encode + + align:start position:0% +can afford to write it down I can encode + + + align:start position:0% +can afford to write it down I can encode +it so that's what we're going to do and + + align:start position:0% +it so that's what we're going to do and + + + align:start position:0% +it so that's what we're going to do and +we'll compute we'll figure out that this + + align:start position:0% +we'll compute we'll figure out that this + + + align:start position:0% +we'll compute we'll figure out that this +is indeed something we can afford I'm + + align:start position:0% +is indeed something we can afford I'm + + + align:start position:0% +is indeed something we can afford I'm +going to encode R intersect W explicitly + + align:start position:0% +going to encode R intersect W explicitly + + + align:start position:0% +going to encode R intersect W explicitly +meaning this is a a set of cells in + + align:start position:0% +meaning this is a a set of cells in + + + align:start position:0% +meaning this is a a set of cells in +memory so for every cell I'm going to + + align:start position:0% +memory so for every cell I'm going to + + + align:start position:0% +memory so for every cell I'm going to +write down what its address is and what + + align:start position:0% +write down what its address is and what + + + align:start position:0% +write down what its address is and what +the contents of the cell are + + align:start position:0% +the contents of the cell are + + + align:start position:0% +the contents of the cell are +so write down the + + align:start position:0% +so write down the + + + align:start position:0% +so write down the +addresses and the + + align:start position:0% +addresses and the + + + align:start position:0% +addresses and the +contents for every such cell so how many + + align:start position:0% +contents for every such cell so how many + + + align:start position:0% +contents for every such cell so how many +bits does that take uh I'm going to say + + align:start position:0% +bits does that take uh I'm going to say + + + align:start position:0% +bits does that take uh I'm going to say +that it's R inter + + align:start position:0% +that it's R inter + + + align:start position:0% +that it's R inter +W time log n + + align:start position:0% + + + + align:start position:0% + +Bits uh here's where I need to mention + + align:start position:0% +Bits uh here's where I need to mention + + + align:start position:0% +Bits uh here's where I need to mention +an assumption uh I'm assuming that the + + align:start position:0% +an assumption uh I'm assuming that the + + + align:start position:0% +an assumption uh I'm assuming that the +address space is order log n Bits long + + align:start position:0% +address space is order log n Bits long + + + align:start position:0% +address space is order log n Bits long +that's like saying that the space of + + align:start position:0% +that's like saying that the space of + + + align:start position:0% +that's like saying that the space of +your data structure is order uh is + + align:start position:0% +your data structure is order uh is + + + align:start position:0% +your data structure is order uh is +polinomial In N and if you want any hope + + align:start position:0% +polinomial In N and if you want any hope + + + align:start position:0% +polinomial In N and if you want any hope +of having a reasonable update time you + + align:start position:0% +of having a reasonable update time you + + + align:start position:0% +of having a reasonable update time you +need to have polinomial space at most so + + align:start position:0% +need to have polinomial space at most so + + + align:start position:0% +need to have polinomial space at most so +assuming polinomial space each of those + + align:start position:0% +assuming polinomial space each of those + + + align:start position:0% +assuming polinomial space each of those +addresses only takes order log n Bits to + + align:start position:0% +addresses only takes order log n Bits to + + + align:start position:0% +addresses only takes order log n Bits to +write down the contents uh let's say + + align:start position:0% +write down the contents uh let's say + + + align:start position:0% +write down the contents uh let's say +also take order log n Bits to write + + align:start position:0% + + + + align:start position:0% + +down okay so + + align:start position:0% +down okay so + + + align:start position:0% +down okay so +fine uh + + align:start position:0% +fine uh + + + align:start position:0% +fine uh +that's uh I mean yeah we don't really + + align:start position:0% +that's uh I mean yeah we don't really + + + align:start position:0% +that's uh I mean yeah we don't really +need to make those assumptions I don't + + align:start position:0% +need to make those assumptions I don't + + + align:start position:0% +need to make those assumptions I don't +think but uh we will for here to keep + + align:start position:0% +think but uh we will for here to keep + + + align:start position:0% +think but uh we will for here to keep +things + + align:start position:0% +things + + + align:start position:0% +things +simple so if R intersect W is small + + align:start position:0% +simple so if R intersect W is small + + + align:start position:0% +simple so if R intersect W is small +meaning smaller than this thing then + + align:start position:0% +meaning smaller than this thing then + + + align:start position:0% +meaning smaller than this thing then +this will be small smaller than L root n + + align:start position:0% +this will be small smaller than L root n + + + align:start position:0% +this will be small smaller than L root n +log + + align:start position:0% + + + + align:start position:0% + +n + + align:start position:0% +n + + + align:start position:0% +n +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so uh on the other hand we know that + + align:start position:0% +so uh on the other hand we know that + + + align:start position:0% +so uh on the other hand we know that +every encoding should take L root n log + + align:start position:0% +every encoding should take L root n log + + + align:start position:0% +every encoding should take L root n log +n + + align:start position:0% +n + + + align:start position:0% +n +Bits right so this will be a + + align:start position:0% +Bits right so this will be a + + + align:start position:0% +Bits right so this will be a +contradiction although we're not we + + align:start position:0% +contradiction although we're not we + + + align:start position:0% +contradiction although we're not we +haven't quite encoded what we need yet + + align:start position:0% +haven't quite encoded what we need yet + + + align:start position:0% +haven't quite encoded what we need yet +uh or we haven't proved that but we're + + align:start position:0% +uh or we haven't proved that but we're + + + align:start position:0% +uh or we haven't proved that but we're +we're getting to be the right point + + align:start position:0% +we're getting to be the right point + + + align:start position:0% +we're getting to be the right point +there these log ends are going to cancel + + align:start position:0% +there these log ends are going to cancel + + + align:start position:0% +there these log ends are going to cancel +in a + + align:start position:0% +in a + + + align:start position:0% +in a +moment so what what we need to do is I + + align:start position:0% +moment so what what we need to do is I + + + align:start position:0% +moment so what what we need to do is I +claim this is actually enough to encode + + align:start position:0% +claim this is actually enough to encode + + + align:start position:0% +claim this is actually enough to encode +what we need and so all that's left is a + + align:start position:0% +what we need and so all that's left is a + + + align:start position:0% +what we need and so all that's left is a +decoding + + align:start position:0% + + + + align:start position:0% + +algorithm uh for the sum + + align:start position:0% +algorithm uh for the sum + + + align:start position:0% +algorithm uh for the sum +queries in the right sub + + align:start position:0% + + + + align:start position:0% + +tree so how we going to do that uh so + + align:start position:0% +tree so how we going to do that uh so + + + align:start position:0% +tree so how we going to do that uh so +this is my encoding these are the bits + + align:start position:0% +this is my encoding these are the bits + + + align:start position:0% +this is my encoding these are the bits +that I have written down so now what I + + align:start position:0% +that I have written down so now what I + + + align:start position:0% +that I have written down so now what I +know as a decoder is I know everything + + align:start position:0% +know as a decoder is I know everything + + + align:start position:0% +know as a decoder is I know everything +about the past I don't know what these + + align:start position:0% +about the past I don't know what these + + + align:start position:0% +about the past I don't know what these +updates are that's my whole goal is to + + align:start position:0% +updates are that's my whole goal is to + + + align:start position:0% +updates are that's my whole goal is to +figure out what they are I don't know + + align:start position:0% +figure out what they are I don't know + + + align:start position:0% +figure out what they are I don't know +what the results of the queries are but + + align:start position:0% +what the results of the queries are but + + + align:start position:0% +what the results of the queries are but +magically I know R intersect W well not + + align:start position:0% +magically I know R intersect W well not + + + align:start position:0% +magically I know R intersect W well not +magically I wrote it down kept on a + + align:start position:0% +magically I wrote it down kept on a + + + align:start position:0% +magically I wrote it down kept on a +piece of paper so that's what I know and + + align:start position:0% +piece of paper so that's what I know and + + + align:start position:0% +piece of paper so that's what I know and +so the idea is well um we somebody gave + + align:start position:0% +so the idea is well um we somebody gave + + + align:start position:0% +so the idea is well um we somebody gave +us a data structure to tells you how to + + align:start position:0% +us a data structure to tells you how to + + + align:start position:0% +us a data structure to tells you how to +do an update tells you how to do a query + + align:start position:0% +do an update tells you how to do a query + + + align:start position:0% +do an update tells you how to do a query +let's run the query algorithm over + + align:start position:0% +let's run the query algorithm over + + + align:start position:0% +let's run the query algorithm over +here run that query run that query + + align:start position:0% +here run that query run that query + + + align:start position:0% +here run that query run that query +whatever uh it's a little hard to run + + align:start position:0% +whatever uh it's a little hard to run + + + align:start position:0% +whatever uh it's a little hard to run +them because we don't know what happened + + align:start position:0% +them because we don't know what happened + + + align:start position:0% +them because we don't know what happened +in this intermediate part but I claim R + + align:start position:0% +in this intermediate part but I claim R + + + align:start position:0% +in this intermediate part but I claim R +intersect W tells us everything we need + + align:start position:0% +intersect W tells us everything we need + + + align:start position:0% +intersect W tells us everything we need +to know so decoding algorithm is just + + align:start position:0% + + + + align:start position:0% + +simulate uh some + + align:start position:0% + + + + align:start position:0% + +queries simulate that + + align:start position:0% +queries simulate that + + + align:start position:0% +queries simulate that +algorithm + + align:start position:0% + + + + align:start position:0% + +uh and let's go up + + align:start position:0% + + + + align:start position:0% + +here how do we simulate that algorithm + + align:start position:0% +here how do we simulate that algorithm + + + align:start position:0% +here how do we simulate that algorithm +well this the algorithm makes a series + + align:start position:0% +well this the algorithm makes a series + + + align:start position:0% +well this the algorithm makes a series +of cell reads and maybe wres but really + + align:start position:0% +of cell reads and maybe wres but really + + + align:start position:0% +of cell reads and maybe wres but really +we care about the + + align:start position:0% +we care about the + + + align:start position:0% +we care about the +reads wres are pretty easy to + + align:start position:0% + + + + align:start position:0% + +simulate there are three cases for reads + + align:start position:0% +simulate there are three cases for reads + + + align:start position:0% +simulate there are three cases for reads +it could be that the thing you're trying + + align:start position:0% +it could be that the thing you're trying + + + align:start position:0% +it could be that the thing you're trying +to read was written in the right sub + + align:start position:0% +to read was written in the right sub + + + align:start position:0% +to read was written in the right sub +tree it could be that it was written in + + align:start position:0% +tree it could be that it was written in + + + align:start position:0% +tree it could be that it was written in +the left sub tree or it could be it was + + align:start position:0% +the left sub tree or it could be it was + + + align:start position:0% +the left sub tree or it could be it was +written in the past before we got to V's + + align:start position:0% +written in the past before we got to V's + + + align:start position:0% +written in the past before we got to V's +sub + + align:start position:0% +sub + + + align:start position:0% +sub +tree now we don't necessarily know which + + align:start position:0% +tree now we don't necessarily know which + + + align:start position:0% +tree now we don't necessarily know which +case we're in but I claim we'll be able + + align:start position:0% +case we're in but I claim we'll be able + + + align:start position:0% +case we're in but I claim we'll be able +to figure it out because any cells that + + align:start position:0% +to figure it out because any cells that + + + align:start position:0% +to figure it out because any cells that +are written in the right subtree well we + + align:start position:0% +are written in the right subtree well we + + + align:start position:0% +are written in the right subtree well we +we've just been running the simulation + + align:start position:0% +we've just been running the simulation + + + align:start position:0% +we've just been running the simulation +algorithm so every time we do a right we + + align:start position:0% +algorithm so every time we do a right we + + + align:start position:0% +algorithm so every time we do a right we +just we can store it off to the side so + + align:start position:0% +just we can store it off to the side so + + + align:start position:0% +just we can store it off to the side so +as when we're doing simulations we don't + + align:start position:0% +as when we're doing simulations we don't + + + align:start position:0% +as when we're doing simulations we don't +need that the simulation takes low speed + + align:start position:0% +need that the simulation takes low speed + + + align:start position:0% +need that the simulation takes low speed +space we just need that the input I this + + align:start position:0% +space we just need that the input I this + + + align:start position:0% +space we just need that the input I this +decoding algorithm doesn't have to be + + align:start position:0% +decoding algorithm doesn't have to be + + + align:start position:0% +decoding algorithm doesn't have to be +low space we just need that the encoding + + align:start position:0% +low space we just need that the encoding + + + align:start position:0% +low space we just need that the encoding +was small we've already made the + + align:start position:0% +was small we've already made the + + + align:start position:0% +was small we've already made the +encoding small and so the decoding + + align:start position:0% +encoding small and so the decoding + + + align:start position:0% +encoding small and so the decoding +algorithm can spend lots of time and + + align:start position:0% +algorithm can spend lots of time and + + + align:start position:0% +algorithm can spend lots of time and +space we just need to show the decoding + + align:start position:0% +space we just need to show the decoding + + + align:start position:0% +space we just need to show the decoding +algorithm can recover what it's supposed + + align:start position:0% +algorithm can recover what it's supposed + + + align:start position:0% +algorithm can recover what it's supposed +to recover this is like a compression + + align:start position:0% +to recover this is like a compression + + + align:start position:0% +to recover this is like a compression +algorithm to show there's some way to + + align:start position:0% +algorithm to show there's some way to + + + align:start position:0% +algorithm to show there's some way to +decompress could take arbitrarily amount + + align:start position:0% +decompress could take arbitrarily amount + + + align:start position:0% +decompress could take arbitrarily amount +of time and space so uh when we're + + align:start position:0% +of time and space so uh when we're + + + align:start position:0% +of time and space so uh when we're +simulating the right subtree I mean we + + align:start position:0% +simulating the right subtree I mean we + + + align:start position:0% +simulating the right subtree I mean we +simulate not only the sum the sum + + align:start position:0% +simulate not only the sum the sum + + + align:start position:0% +simulate not only the sum the sum +queries but also the + + align:start position:0% +queries but also the + + + align:start position:0% +queries but also the +updates + + align:start position:0% +updates + + + align:start position:0% +updates +so whatever gets written during that + + align:start position:0% +so whatever gets written during that + + + align:start position:0% +so whatever gets written during that +simulation we just store it and so easy + + align:start position:0% +simulation we just store it and so easy + + + align:start position:0% +simulation we just store it and so easy +to reread it if it was store if it was + + align:start position:0% +to reread it if it was store if it was + + + align:start position:0% +to reread it if it was store if it was +written in the left sub tree well that + + align:start position:0% +written in the left sub tree well that + + + align:start position:0% +written in the left sub tree well that +is R intersect + + align:start position:0% + + + + align:start position:0% + +W and we've written down our intersect W + + align:start position:0% +W and we've written down our intersect W + + + align:start position:0% +W and we've written down our intersect W +so we can detect that this happened + + align:start position:0% +so we can detect that this happened + + + align:start position:0% +so we can detect that this happened +because we look at uh our intersect w we + + align:start position:0% +because we look at uh our intersect w we + + + align:start position:0% +because we look at uh our intersect w we +see oh that word was in there that + + align:start position:0% +see oh that word was in there that + + + align:start position:0% +see oh that word was in there that +address was in there and so we read the + + align:start position:0% +address was in there and so we read the + + + align:start position:0% +address was in there and so we read the +contents from the + + align:start position:0% +contents from the + + + align:start position:0% +contents from the +encoding if it was in the past + + align:start position:0% +encoding if it was in the past + + + align:start position:0% +encoding if it was in the past +uh it's also + + align:start position:0% +uh it's also + + + align:start position:0% +uh it's also +easy we already knew + + align:start position:0% +easy we already knew + + + align:start position:0% +easy we already knew +it okay so basically what we + + align:start position:0% +it okay so basically what we + + + align:start position:0% +it okay so basically what we +do what the simulation algorithm is + + align:start position:0% +do what the simulation algorithm is + + + align:start position:0% +do what the simulation algorithm is +doing is it says okay let's assume that + + align:start position:0% +doing is it says okay let's assume that + + + align:start position:0% +doing is it says okay let's assume that +main memory was whatever it was at this + + align:start position:0% +main memory was whatever it was at this + + + align:start position:0% +main memory was whatever it was at this +point the data structure I mean we know + + align:start position:0% +point the data structure I mean we know + + + align:start position:0% +point the data structure I mean we know +everything about the past so we know + + align:start position:0% +everything about the past so we know + + + align:start position:0% +everything about the past so we know +what the data structure looked like at + + align:start position:0% +what the data structure looked like at + + + align:start position:0% +what the data structure looked like at +this moment store that uh update all of + + align:start position:0% +this moment store that uh update all of + + + align:start position:0% +this moment store that uh update all of +the cells that are in R intersect W + + align:start position:0% +the cells that are in R intersect W + + + align:start position:0% +the cells that are in R intersect W +given by our encoding and then just run + + align:start position:0% +given by our encoding and then just run + + + align:start position:0% +given by our encoding and then just run +the algorithm so we're sort of jumping + + align:start position:0% +the algorithm so we're sort of jumping + + + align:start position:0% +the algorithm so we're sort of jumping +into this moment in time with a slightly + + align:start position:0% +into this moment in time with a slightly + + + align:start position:0% +into this moment in time with a slightly +weird data structure it's not the + + align:start position:0% +weird data structure it's not the + + + align:start position:0% +weird data structure it's not the +correct data + + align:start position:0% +correct data + + + align:start position:0% +correct data +structure uh it's not what the data + + align:start position:0% +structure uh it's not what the data + + + align:start position:0% +structure uh it's not what the data +structure will actually look like at + + align:start position:0% +structure will actually look like at + + + align:start position:0% +structure will actually look like at +this point but it's close enough because + + align:start position:0% +this point but it's close enough because + + + align:start position:0% +this point but it's close enough because +anything that's read here uh either was + + align:start position:0% +anything that's read here uh either was + + + align:start position:0% +anything that's read here uh either was +written here which case it's correct or + + align:start position:0% +written here which case it's correct or + + + align:start position:0% +written here which case it's correct or +was written here in which case it's + + align:start position:0% +was written here in which case it's + + + align:start position:0% +was written here in which case it's +correct because R intersect W had it um + + align:start position:0% +correct because R intersect W had it um + + + align:start position:0% +correct because R intersect W had it um +or is written here in which case maybe + + align:start position:0% +or is written here in which case maybe + + + align:start position:0% +or is written here in which case maybe +it's always + + align:start position:0% +it's always + + + align:start position:0% +it's always +correct no no see there could be some + + align:start position:0% +correct no no see there could be some + + + align:start position:0% +correct no no see there could be some +rights that happened here where there's + + align:start position:0% +rights that happened here where there's + + + align:start position:0% +rights that happened here where there's +no corresponding read over here so the + + align:start position:0% +no corresponding read over here so the + + + align:start position:0% +no corresponding read over here so the +data structure may have been changed in + + align:start position:0% +data structure may have been changed in + + + align:start position:0% +data structure may have been changed in +ways here that don't matter for this R + + align:start position:0% +ways here that don't matter for this R + + + align:start position:0% +ways here that don't matter for this R +execution of the right sub tree because + + align:start position:0% +execution of the right sub tree because + + + align:start position:0% +execution of the right sub tree because +any rights that happen here to some cell + + align:start position:0% +any rights that happen here to some cell + + + align:start position:0% +any rights that happen here to some cell +probe to some cell where that cell is + + align:start position:0% +probe to some cell where that cell is + + + align:start position:0% +probe to some cell where that cell is +not red over here we don't care about + + align:start position:0% +not red over here we don't care about + + + align:start position:0% +not red over here we don't care about +because they don't affect the simulation + + align:start position:0% +because they don't affect the simulation + + + align:start position:0% +because they don't affect the simulation +so we have a good enough data structure + + align:start position:0% +so we have a good enough data structure + + + align:start position:0% +so we have a good enough data structure +over here may not be completely accurate + + align:start position:0% +over here may not be completely accurate + + + align:start position:0% +over here may not be completely accurate +but it's accurate enough to run these + + align:start position:0% +but it's accurate enough to run these + + + align:start position:0% +but it's accurate enough to run these +queries once we run the queries the + + align:start position:0% +queries once we run the queries the + + + align:start position:0% +queries once we run the queries the +queries output the sums that's what + + align:start position:0% +queries output the sums that's what + + + align:start position:0% +queries output the sums that's what +we're assuming in this warmup We Run The + + align:start position:0% +we're assuming in this warmup We Run The + + + align:start position:0% +we're assuming in this warmup We Run The +query we get the sum once I have that + + align:start position:0% +query we get the sum once I have that + + + align:start position:0% +query we get the sum once I have that +sum as I argued before once you know + + align:start position:0% +sum as I argued before once you know + + + align:start position:0% +sum as I argued before once you know +what the results of these queries were I + + align:start position:0% +what the results of these queries were I + + + align:start position:0% +what the results of these queries were I +can figure out what the arguments to the + + align:start position:0% +can figure out what the arguments to the + + + align:start position:0% +can figure out what the arguments to the +updates were by doing that inverse + + align:start position:0% +updates were by doing that inverse + + + align:start position:0% +updates were by doing that inverse +multiplication stuff okay so that's + + align:start position:0% +multiplication stuff okay so that's + + + align:start position:0% +multiplication stuff okay so that's +actually it what this + + align:start position:0% +actually it what this + + + align:start position:0% +actually it what this +implies is that this is a correct + + align:start position:0% +implies is that this is a correct + + + align:start position:0% +implies is that this is a correct +encoding which means that this uh order + + align:start position:0% +encoding which means that this uh order + + + align:start position:0% +encoding which means that this uh order +R intersect w time log n Bits that we + + align:start position:0% +R intersect w time log n Bits that we + + + align:start position:0% +R intersect w time log n Bits that we +use to encode must be at least this big + + align:start position:0% +use to encode must be at least this big + + + align:start position:0% +use to encode must be at least this big +because we know and any encoding is + + align:start position:0% +because we know and any encoding is + + + align:start position:0% +because we know and any encoding is +going to require at least that many + + align:start position:0% +going to require at least that many + + + align:start position:0% +going to require at least that many +bits L root n log + + align:start position:0% +bits L root n log + + + align:start position:0% +bits L root n log +n and so the log n's + + align:start position:0% +n and so the log n's + + + align:start position:0% +n and so the log n's +cancel and we're left with r intersect W + + align:start position:0% +cancel and we're left with r intersect W + + + align:start position:0% +cancel and we're left with r intersect W +is at least L root n and this is exactly + + align:start position:0% +is at least L root n and this is exactly + + + align:start position:0% +is at least L root n and this is exactly +the quantity we cared about for this + + align:start position:0% +the quantity we cared about for this + + + align:start position:0% +the quantity we cared about for this +claim so same thing R intersect is at + + align:start position:0% +claim so same thing R intersect is at + + + align:start position:0% +claim so same thing R intersect is at +least lot + + align:start position:0% +least lot + + + align:start position:0% +least lot +n okay so warmup done any questions + + align:start position:0% +n okay so warmup done any questions + + + align:start position:0% +n okay so warmup done any questions +about the + + align:start position:0% +about the + + + align:start position:0% +about the +warmup so in this weird problem which + + align:start position:0% +warmup so in this weird problem which + + + align:start position:0% +warmup so in this weird problem which +does not correspond to Dynamic + + align:start position:0% +does not correspond to Dynamic + + + align:start position:0% +does not correspond to Dynamic +connectivity it's this other problem + + align:start position:0% +connectivity it's this other problem + + + align:start position:0% +connectivity it's this other problem +prefix sums computation uh we get the + + align:start position:0% +prefix sums computation uh we get the + + + align:start position:0% +prefix sums computation uh we get the +intended lower bound you need log n per + + align:start position:0% +intended lower bound you need log n per + + + align:start position:0% +intended lower bound you need log n per +operation or need root n log n per block + + align:start position:0% +operation or need root n log n per block + + + align:start position:0% +operation or need root n log n per block +operation okay but this is not what we + + align:start position:0% +operation okay but this is not what we + + + align:start position:0% +operation okay but this is not what we +really want we really want a lower bound + + align:start position:0% +really want we really want a lower bound + + + align:start position:0% +really want we really want a lower bound +on verify sum well you're given as an + + align:start position:0% +on verify sum well you're given as an + + + align:start position:0% +on verify sum well you're given as an +argument the permutation that we're + + align:start position:0% +argument the permutation that we're + + + align:start position:0% +argument the permutation that we're +talking about over here so it's uh this + + align:start position:0% +talking about over here so it's uh this + + + align:start position:0% +talking about over here so it's uh this +goal is not the right goal for verify + + align:start position:0% +goal is not the right goal for verify + + + align:start position:0% +goal is not the right goal for verify +sum in some sense well sort of the right + + align:start position:0% +sum in some sense well sort of the right + + + align:start position:0% +sum in some sense well sort of the right +goal it's a little awkward though + + align:start position:0% +goal it's a little awkward though + + + align:start position:0% +goal it's a little awkward though +because they're given as inputs to the + + align:start position:0% +because they're given as inputs to the + + + align:start position:0% +because they're given as inputs to the +queries so what is there to + + align:start position:0% +queries so what is there to + + + align:start position:0% +queries so what is there to +encode well we can still set it up in a + + align:start position:0% +encode well we can still set it up in a + + + align:start position:0% +encode well we can still set it up in a +useful way same goal slightly + + align:start position:0% +useful way same goal slightly + + + align:start position:0% +useful way same goal slightly +restated + + align:start position:0% +restated + + + align:start position:0% +restated +[Applause] + + align:start position:0% + + + + align:start position:0% + +so this is the the last step to verify + + align:start position:0% +so this is the the last step to verify + + + align:start position:0% +so this is the the last step to verify +some lower + + align:start position:0% + + + + align:start position:0% + +bound + + align:start position:0% + + + + align:start position:0% + +so here's the + + align:start position:0% + + + + align:start position:0% + +setup + + align:start position:0% + + + + align:start position:0% + +is + + align:start position:0% + + + + align:start position:0% + +okay it's a slightly different setup + + align:start position:0% +okay it's a slightly different setup + + + align:start position:0% +okay it's a slightly different setup +here here I assume that we just knew the + + align:start position:0% +here here I assume that we just knew the + + + align:start position:0% +here here I assume that we just knew the +past uh I also basically assumed these + + align:start position:0% +past uh I also basically assumed these + + + align:start position:0% +past uh I also basically assumed these +two things that we don't we didn't know + + align:start position:0% +two things that we don't we didn't know + + + align:start position:0% +two things that we don't we didn't know +what the update permutations were in the + + align:start position:0% +what the update permutations were in the + + + align:start position:0% +what the update permutations were in the +left sub tree and we didn't know what + + align:start position:0% +left sub tree and we didn't know what + + + align:start position:0% +left sub tree and we didn't know what +the answers to the queries were in the + + align:start position:0% +the answers to the queries were in the + + + align:start position:0% +the answers to the queries were in the +right sub tree now I'm going to assume + + align:start position:0% +right sub tree now I'm going to assume + + + align:start position:0% +right sub tree now I'm going to assume +we don't even know what we're passing + + align:start position:0% +we don't even know what we're passing + + + align:start position:0% +we don't even know what we're passing +into the queries because is the + + align:start position:0% +into the queries because is the + + + align:start position:0% +into the queries because is the +information we're trying to figure out + + align:start position:0% +information we're trying to figure out + + + align:start position:0% +information we're trying to figure out +or these two things are basically the + + align:start position:0% +or these two things are basically the + + + align:start position:0% +or these two things are basically the +same if if you knew all the update + + align:start position:0% +same if if you knew all the update + + + align:start position:0% +same if if you knew all the update +permutations you could figure out all + + align:start position:0% +permutations you could figure out all + + + align:start position:0% +permutations you could figure out all +the query permutations if you knew all + + align:start position:0% +the query permutations if you knew all + + + align:start position:0% +the query permutations if you knew all +the query permutations you could figure + + align:start position:0% +the query permutations you could figure + + + align:start position:0% +the query permutations you could figure +out all the update permutations that's + + align:start position:0% +out all the update permutations that's + + + align:start position:0% +out all the update permutations that's +what we argued over here it was enough + + align:start position:0% +what we argued over here it was enough + + + align:start position:0% +what we argued over here it was enough +to figure out uh query permutations that + + align:start position:0% +to figure out uh query permutations that + + + align:start position:0% +to figure out uh query permutations that +we could figure out the update + + align:start position:0% +we could figure out the update + + + align:start position:0% +we could figure out the update +permutations uh it's just a little more + + align:start position:0% +permutations uh it's just a little more + + + align:start position:0% +permutations uh it's just a little more +Awkward because now they're arguments to + + align:start position:0% +Awkward because now they're arguments to + + + align:start position:0% +Awkward because now they're arguments to +queries and so if we did this simulation + + align:start position:0% +queries and so if we did this simulation + + + align:start position:0% +queries and so if we did this simulation +right we' simulate we don't know how to + + align:start position:0% +right we' simulate we don't know how to + + + align:start position:0% +right we' simulate we don't know how to +simulate the quer query algorithm + + align:start position:0% +simulate the quer query algorithm + + + align:start position:0% +simulate the quer query algorithm +because it's supposed to be given the + + align:start position:0% +because it's supposed to be given the + + + align:start position:0% +because it's supposed to be given the +argument which is what we're trying to + + align:start position:0% +argument which is what we're trying to + + + align:start position:0% +argument which is what we're trying to +figure out so we can't simulate the + + align:start position:0% +figure out so we can't simulate the + + + align:start position:0% +figure out so we can't simulate the +query + + align:start position:0% + + + + align:start position:0% + +algorithm it's kind of annoying but + + align:start position:0% +algorithm it's kind of annoying but + + + align:start position:0% +algorithm it's kind of annoying but +otherwise the setup is roughly the same + + align:start position:0% +otherwise the setup is roughly the same + + + align:start position:0% +otherwise the setup is roughly the same +uh the one thing we know is that the + + align:start position:0% +uh the one thing we know is that the + + + align:start position:0% +uh the one thing we know is that the +query is supposed to return Yes because + + align:start position:0% +query is supposed to return Yes because + + + align:start position:0% +query is supposed to return Yes because +if you look at uh this bad access + + align:start position:0% +if you look at uh this bad access + + + align:start position:0% +if you look at uh this bad access +sequence it is designed to always return + + align:start position:0% +sequence it is designed to always return + + + align:start position:0% +sequence it is designed to always return +yes so that is a a thing we know um but + + align:start position:0% +yes so that is a a thing we know um but + + + align:start position:0% +yes so that is a a thing we know um but +we don't know the arguments to the + + align:start position:0% +we don't know the arguments to the + + + align:start position:0% +we don't know the arguments to the +updates on the left we don't know + + align:start position:0% +updates on the left we don't know + + + align:start position:0% +updates on the left we don't know +arguments the updates on the right we'll + + align:start position:0% +arguments the updates on the right we'll + + + align:start position:0% +arguments the updates on the right we'll +assume we know everything else basically + + align:start position:0% +assume we know everything else basically + + + align:start position:0% +assume we know everything else basically +up to this time again this is a a + + align:start position:0% +up to this time again this is a a + + + align:start position:0% +up to this time again this is a a +probabilistic statement that uh + + align:start position:0% +probabilistic statement that uh + + + align:start position:0% +probabilistic statement that uh +conditioned on the past conditioned on + + align:start position:0% +conditioned on the past conditioned on + + + align:start position:0% +conditioned on the past conditioned on +the queries on the left which probably + + align:start position:0% +the queries on the left which probably + + + align:start position:0% +the queries on the left which probably +don't matter conditioned on the updates + + align:start position:0% +don't matter conditioned on the updates + + + align:start position:0% +don't matter conditioned on the updates +on the right which do matter but they're + + align:start position:0% +on the right which do matter but they're + + + align:start position:0% +on the right which do matter but they're +sort of irrelevant to this R intersect W + + align:start position:0% +sort of irrelevant to this R intersect W + + + align:start position:0% +sort of irrelevant to this R intersect W +issue uh conditioned on all those things + + align:start position:0% +issue uh conditioned on all those things + + + align:start position:0% +issue uh conditioned on all those things +will prove that the expected number of + + align:start position:0% +will prove that the expected number of + + + align:start position:0% +will prove that the expected number of +operations you need to or expected + + align:start position:0% +operations you need to or expected + + + align:start position:0% +operations you need to or expected +encoding size for this problem is at + + align:start position:0% +encoding size for this problem is at + + + align:start position:0% +encoding size for this problem is at +least what it is L root n log n Bits And + + align:start position:0% +least what it is L root n log n Bits And + + + align:start position:0% +least what it is L root n log n Bits And +from that lower bound you can then uh + + align:start position:0% +from that lower bound you can then uh + + + align:start position:0% +from that lower bound you can then uh +take the sum over all possible setups + + align:start position:0% +take the sum over all possible setups + + + align:start position:0% +take the sum over all possible setups +overall + + align:start position:0% +overall + + + align:start position:0% +overall +conditions and that implies a lower + + align:start position:0% +conditions and that implies a lower + + + align:start position:0% +conditions and that implies a lower +bound on the overall setting without + + align:start position:0% +bound on the overall setting without + + + align:start position:0% +bound on the overall setting without +these + + align:start position:0% +these + + + align:start position:0% +these +assumptions + + align:start position:0% +assumptions + + + align:start position:0% +assumptions +okay so all I'm saying is in this setup + + align:start position:0% +okay so all I'm saying is in this setup + + + align:start position:0% +okay so all I'm saying is in this setup +it still takes a lot of bits to encode + + align:start position:0% +it still takes a lot of bits to encode + + + align:start position:0% +it still takes a lot of bits to encode +these updates because we don't have the + + align:start position:0% +these updates because we don't have the + + + align:start position:0% +these updates because we don't have the +queries which would tell us the answers + + align:start position:0% +queries which would tell us the answers + + + align:start position:0% +queries which would tell us the answers +so we get a lower bound on encoding + + align:start position:0% +so we get a lower bound on encoding + + + align:start position:0% +so we get a lower bound on encoding +these updates or a lower bound encoding + + align:start position:0% +these updates or a lower bound encoding + + + align:start position:0% +these updates or a lower bound encoding +these queries because we assume we don't + + align:start position:0% +these queries because we assume we don't + + + align:start position:0% +these queries because we assume we don't +know them the rest of the all the + + align:start position:0% +know them the rest of the all the + + + align:start position:0% +know them the rest of the all the +remaining operations don't tell us + + align:start position:0% +remaining operations don't tell us + + + align:start position:0% +remaining operations don't tell us +enough about + + align:start position:0% +enough about + + + align:start position:0% +enough about +this okay so how the heck are we going + + align:start position:0% +this okay so how the heck are we going + + + align:start position:0% +this okay so how the heck are we going +to do prove a lower Bound in this + + align:start position:0% +to do prove a lower Bound in this + + + align:start position:0% +to do prove a lower Bound in this +setting when we can't simulate the query + + align:start position:0% +setting when we can't simulate the query + + + align:start position:0% +setting when we can't simulate the query +algorithm it's one cool idea to make + + align:start position:0% +algorithm it's one cool idea to make + + + align:start position:0% +algorithm it's one cool idea to make +this + + align:start position:0% + + + + align:start position:0% + +work you may recall our last uh Cell Pro + + align:start position:0% +work you may recall our last uh Cell Pro + + + align:start position:0% +work you may recall our last uh Cell Pro +blower + + align:start position:0% +blower + + + align:start position:0% +blower +Bound for the the predecessor + + align:start position:0% + + + + align:start position:0% + +problem uh use this idea of round + + align:start position:0% +problem uh use this idea of round + + + align:start position:0% +problem uh use this idea of round +elimination the idea with round + + align:start position:0% +elimination the idea with round + + + align:start position:0% +elimination the idea with round +elimination was uh Alice was sending a + + align:start position:0% +elimination was uh Alice was sending a + + + align:start position:0% +elimination was uh Alice was sending a +message Bob was sending a response but + + align:start position:0% +message Bob was sending a response but + + + align:start position:0% +message Bob was sending a response but +that first me we set things up we set up + + align:start position:0% +that first me we set things up we set up + + + align:start position:0% +that first me we set things up we set up +the problem so the first message sent by + + align:start position:0% +the problem so the first message sent by + + + align:start position:0% +the problem so the first message sent by +Alice had on average less than one bit + + align:start position:0% +Alice had on average less than one bit + + + align:start position:0% +Alice had on average less than one bit +of information to Bob or very little + + align:start position:0% +of information to Bob or very little + + + align:start position:0% +of information to Bob or very little +information to Bob and so what Bob could + + align:start position:0% +information to Bob and so what Bob could + + + align:start position:0% +information to Bob and so what Bob could +do is basically guess what that message + + align:start position:0% +do is basically guess what that message + + + align:start position:0% +do is basically guess what that message +was and that would be accurate with some + + align:start position:0% +was and that would be accurate with some + + + align:start position:0% +was and that would be accurate with some +probability now here we're not quite + + align:start position:0% +probability now here we're not quite + + + align:start position:0% +probability now here we're not quite +allowed to do that we're not allowed to + + align:start position:0% +allowed to do that we're not allowed to + + + align:start position:0% +allowed to do that we're not allowed to +change the accuracy of our results + + align:start position:0% +change the accuracy of our results + + + align:start position:0% +change the accuracy of our results +because of our particular setting uh so + + align:start position:0% +because of our particular setting uh so + + + align:start position:0% +because of our particular setting uh so +we can't afford to just guess by like + + align:start position:0% +we can't afford to just guess by like + + + align:start position:0% +we can't afford to just guess by like +flipping coins what we were supposed to + + align:start position:0% +flipping coins what we were supposed to + + + align:start position:0% +flipping coins what we were supposed to +know uh what we supposed to know here is + + align:start position:0% +know uh what we supposed to know here is + + + align:start position:0% +know uh what we supposed to know here is +we're trying to simulate a query + + align:start position:0% +we're trying to simulate a query + + + align:start position:0% +we're trying to simulate a query +operation and so we need to know the + + align:start position:0% +operation and so we need to know the + + + align:start position:0% +operation and so we need to know the +argument that whole permutation to the + + align:start position:0% +argument that whole permutation to the + + + align:start position:0% +argument that whole permutation to the +query it's hard to run it without that + + align:start position:0% +query it's hard to run it without that + + + align:start position:0% +query it's hard to run it without that +permutation so instead of guessing by + + align:start position:0% +permutation so instead of guessing by + + + align:start position:0% +permutation so instead of guessing by +flipping coins we're going to guess in + + align:start position:0% +flipping coins we're going to guess in + + + align:start position:0% +flipping coins we're going to guess in +the dynamic programming sense which is + + align:start position:0% +the dynamic programming sense which is + + + align:start position:0% +the dynamic programming sense which is +going to try all the + + align:start position:0% +going to try all the + + + align:start position:0% +going to try all the +possibilities run this simulation over + + align:start position:0% +possibilities run this simulation over + + + align:start position:0% +possibilities run this simulation over +all possible queries all possible second + + align:start position:0% +all possible queries all possible second + + + align:start position:0% +all possible queries all possible second +arguments to the query we don't know + + align:start position:0% +arguments to the query we don't know + + + align:start position:0% +arguments to the query we don't know +what the permutation is so just try them + + align:start position:0% +what the permutation is so just try them + + + align:start position:0% +what the permutation is so just try them +all cool thing is only one argument here + + align:start position:0% +all cool thing is only one argument here + + + align:start position:0% +all cool thing is only one argument here +should return yes that's the one we're + + align:start position:0% +should return yes that's the one we're + + + align:start position:0% +should return yes that's the one we're +looking for so if we try them all find + + align:start position:0% +looking for so if we try them all find + + + align:start position:0% +looking for so if we try them all find +which one says yes we'll be + + align:start position:0% +which one says yes we'll be + + + align:start position:0% +which one says yes we'll be +done so this is called the decod + + align:start position:0% + + + + align:start position:0% + +idea uh + + align:start position:0% + + + + align:start position:0% + +simulate uh verify + + align:start position:0% + + + + align:start position:0% + +sum of I comma Pi for all + + align:start position:0% +sum of I comma Pi for all + + + align:start position:0% +sum of I comma Pi for all +pi and take the one that returns yes + + align:start position:0% +pi and take the one that returns yes + + + align:start position:0% +pi and take the one that returns yes +that is our permutation and so if we + + align:start position:0% +that is our permutation and so if we + + + align:start position:0% +that is our permutation and so if we +figure out what those query permutations + + align:start position:0% +figure out what those query permutations + + + align:start position:0% +figure out what those query permutations +are then we figure out what the update + + align:start position:0% +are then we figure out what the update + + + align:start position:0% +are then we figure out what the update +permutations are and we get our lower + + align:start position:0% +permutations are and we get our lower + + + align:start position:0% +permutations are and we get our lower +balce just like + + align:start position:0% +balce just like + + + align:start position:0% +balce just like +before okay uh this is easier said than + + align:start position:0% +before okay uh this is easier said than + + + align:start position:0% +before okay uh this is easier said than +done unfortunately um we'd like to run + + align:start position:0% +done unfortunately um we'd like to run + + + align:start position:0% +done unfortunately um we'd like to run +the simulation just + + align:start position:0% +the simulation just + + + align:start position:0% +the simulation just +like here so simulating query algorith + + align:start position:0% +like here so simulating query algorith + + + align:start position:0% +like here so simulating query algorith +we said okay still the case that if + + align:start position:0% +we said okay still the case that if + + + align:start position:0% +we said okay still the case that if +you're reading a Cell It's either in the + + align:start position:0% +you're reading a Cell It's either in the + + + align:start position:0% +you're reading a Cell It's either in the +left sub tree in the right sub tree or + + align:start position:0% +left sub tree in the right sub tree or + + + align:start position:0% +left sub tree in the right sub tree or +in the + + align:start position:0% +in the + + + align:start position:0% +in the +past uh and we said this was easy this + + align:start position:0% +past uh and we said this was easy this + + + align:start position:0% +past uh and we said this was easy this +was known and the hard part is this case + + align:start position:0% +was known and the hard part is this case + + + align:start position:0% +was known and the hard part is this case +because if we're running this + + align:start position:0% +because if we're running this + + + align:start position:0% +because if we're running this +query and it reads something that was + + align:start position:0% +query and it reads something that was + + + align:start position:0% +query and it reads something that was +written in the left subtree it may not + + align:start position:0% +written in the left subtree it may not + + + align:start position:0% +written in the left subtree it may not +be in R intersect + + align:start position:0% +be in R intersect + + + align:start position:0% +be in R intersect +w why is + + align:start position:0% +w why is + + + align:start position:0% +w why is +that little puzzle for + + align:start position:0% +that little puzzle for + + + align:start position:0% +that little puzzle for +you so we're running one of these + + align:start position:0% +you so we're running one of these + + + align:start position:0% +you so we're running one of these +queries for some pi and I claim that + + align:start position:0% +queries for some pi and I claim that + + + align:start position:0% +queries for some pi and I claim that +when we read something left sub tree we + + align:start position:0% +when we read something left sub tree we + + + align:start position:0% +when we read something left sub tree we +don't know if it's an R intersect W + + align:start position:0% +don't know if it's an R intersect W + + + align:start position:0% +don't know if it's an R intersect W +might not + + align:start position:0% + + + + align:start position:0% + +be + + align:start position:0% + + + + align:start position:0% + +see if we're on the same page so + + align:start position:0% +see if we're on the same page so + + + align:start position:0% +see if we're on the same page so +r r is a set of cells read during the + + align:start position:0% +r r is a set of cells read during the + + + align:start position:0% +r r is a set of cells read during the +right subtree when executing these + + align:start position:0% +right subtree when executing these + + + align:start position:0% +right subtree when executing these +operations okay but what we're doing now + + align:start position:0% +operations okay but what we're doing now + + + align:start position:0% +operations okay but what we're doing now +is simulating some executions that + + align:start position:0% +is simulating some executions that + + + align:start position:0% +is simulating some executions that +didn't necessarily happen we're doing + + align:start position:0% +didn't necessarily happen we're doing + + + align:start position:0% +didn't necessarily happen we're doing +verify sum of I comma Pi but in the bad + + align:start position:0% +verify sum of I comma Pi but in the bad + + + align:start position:0% +verify sum of I comma Pi but in the bad +access sequence we did verify sum of I + + align:start position:0% +access sequence we did verify sum of I + + + align:start position:0% +access sequence we did verify sum of I +comma something specific not any PI but + + align:start position:0% +comma something specific not any PI but + + + align:start position:0% +comma something specific not any PI but +the correct Pi so we only ran the yes + + align:start position:0% +the correct Pi so we only ran the yes + + + align:start position:0% +the correct Pi so we only ran the yes +verify sums and that's what R is defined + + align:start position:0% +verify sums and that's what R is defined + + + align:start position:0% +verify sums and that's what R is defined +with respect to R is a set of things to + + align:start position:0% +with respect to R is a set of things to + + + align:start position:0% +with respect to R is a set of things to +get read during these operations where + + align:start position:0% +get read during these operations where + + + align:start position:0% +get read during these operations where +the verify sums always output yes if you + + align:start position:0% +the verify sums always output yes if you + + + align:start position:0% +the verify sums always output yes if you +now run a verify sum where the answer is + + align:start position:0% +now run a verify sum where the answer is + + + align:start position:0% +now run a verify sum where the answer is +no it may read stuff that the other + + align:start position:0% +no it may read stuff that the other + + + align:start position:0% +no it may read stuff that the other +verify sum didn't read maybe shouldn't + + align:start position:0% +verify sum didn't read maybe shouldn't + + + align:start position:0% +verify sum didn't read maybe shouldn't +matter but it's awkward because now it's + + align:start position:0% +matter but it's awkward because now it's + + + align:start position:0% +matter but it's awkward because now it's +not just R intersect w we need to encode + + align:start position:0% +not just R intersect w we need to encode + + + align:start position:0% +not just R intersect w we need to encode +we need to encode some more stuff + + align:start position:0% +we need to encode some more stuff + + + align:start position:0% +we need to encode some more stuff +it's basically a new RP Prime that may + + align:start position:0% +it's basically a new RP Prime that may + + + align:start position:0% +it's basically a new RP Prime that may +happen during these reads and we just + + align:start position:0% +happen during these reads and we just + + + align:start position:0% +happen during these reads and we just +can't afford to encode that RP Prime + + align:start position:0% +can't afford to encode that RP Prime + + + align:start position:0% +can't afford to encode that RP Prime +because it's not the thing we care about + + align:start position:0% +because it's not the thing we care about + + + align:start position:0% +because it's not the thing we care about +we care about what happens in the actual + + align:start position:0% +we care about what happens in the actual + + + align:start position:0% +we care about what happens in the actual +AIS sequence not in this arbitrary + + align:start position:0% +AIS sequence not in this arbitrary + + + align:start position:0% +AIS sequence not in this arbitrary +simulation so + + align:start position:0% +simulation so + + + align:start position:0% +simulation so +uh This Is The Annoying Thing uh + + align:start position:0% + + + + align:start position:0% + +trouble if you look at an incorrect + + align:start position:0% +trouble if you look at an incorrect + + + align:start position:0% +trouble if you look at an incorrect +query + + align:start position:0% +query + + + align:start position:0% +query +meaning the the wrong + + align:start position:0% +meaning the the wrong + + + align:start position:0% +meaning the the wrong +Pi so this is like a no query the + + align:start position:0% +Pi so this is like a no query the + + + align:start position:0% +Pi so this is like a no query the +output's + + align:start position:0% +output's + + + align:start position:0% +output's +no uh reads some different set of + + align:start position:0% +no uh reads some different set of + + + align:start position:0% +no uh reads some different set of +cells R Prime which isn't the same thing + + align:start position:0% +cells R Prime which isn't the same thing + + + align:start position:0% +cells R Prime which isn't the same thing +as + + align:start position:0% +as + + + align:start position:0% +as +R and so + + align:start position:0% + + + + align:start position:0% + +if we have some good news which is if we + + align:start position:0% +if we have some good news which is if we + + + align:start position:0% +if we have some good news which is if we +could somehow detect that this happened + + align:start position:0% +could somehow detect that this happened + + + align:start position:0% +could somehow detect that this happened +that we read something that is in our + + align:start position:0% +that we read something that is in our + + + align:start position:0% +that we read something that is in our +Prime but not + + align:start position:0% +Prime but not + + + align:start position:0% +Prime but not +R uh then the answer must be + + align:start position:0% + + + + align:start position:0% + +no so that's our our Saving Hope is that + + align:start position:0% +no so that's our our Saving Hope is that + + + align:start position:0% +no so that's our our Saving Hope is that +either uh we're reading something in R + + align:start position:0% +either uh we're reading something in R + + + align:start position:0% +either uh we're reading something in R +intersect W in which case it's been + + align:start position:0% +intersect W in which case it's been + + + align:start position:0% +intersect W in which case it's been +written down we know how to do it or + + align:start position:0% +written down we know how to do it or + + + align:start position:0% +written down we know how to do it or +it's not written + + align:start position:0% +it's not written + + + align:start position:0% +it's not written +there and if it's not written there then + + align:start position:0% +there and if it's not written there then + + + align:start position:0% +there and if it's not written there then +it should be hopefully in R Prime minus + + align:start position:0% +it should be hopefully in R Prime minus + + + align:start position:0% +it should be hopefully in R Prime minus +r and so the answer should be + + align:start position:0% +r and so the answer should be + + + align:start position:0% +r and so the answer should be +no maybe maybe slight problem though + + align:start position:0% +no maybe maybe slight problem though + + + align:start position:0% +no maybe maybe slight problem though +because we used R intersect W to detect + + align:start position:0% +because we used R intersect W to detect + + + align:start position:0% +because we used R intersect W to detect +what case we were in if we were in our + + align:start position:0% +what case we were in if we were in our + + + align:start position:0% +what case we were in if we were in our +our intersect W then we knew we should + + align:start position:0% +our intersect W then we knew we should + + + align:start position:0% +our intersect W then we knew we should +read from those encoded cells if we + + align:start position:0% +read from those encoded cells if we + + + align:start position:0% +read from those encoded cells if we +weren't uh we were either in the past or + + align:start position:0% +weren't uh we were either in the past or + + + align:start position:0% +weren't uh we were either in the past or +in the right sub tree these things we + + align:start position:0% +in the right sub tree these things we + + + align:start position:0% +in the right sub tree these things we +are easy to detect because they got + + align:start position:0% +are easy to detect because they got + + + align:start position:0% +are easy to detect because they got +written during the simulation but we + + align:start position:0% +written during the simulation but we + + + align:start position:0% +written during the simulation but we +need to distinguish between did we read + + align:start position:0% +need to distinguish between did we read + + + align:start position:0% +need to distinguish between did we read +something that was in the left sub tree + + align:start position:0% +something that was in the left sub tree + + + align:start position:0% +something that was in the left sub tree +or did we read something that was known + + align:start position:0% +or did we read something that was known + + + align:start position:0% +or did we read something that was known +this is a little tricky because this + + align:start position:0% +this is a little tricky because this + + + align:start position:0% +this is a little tricky because this +gets it exactly the issue left sub tree + + align:start position:0% +gets it exactly the issue left sub tree + + + align:start position:0% +gets it exactly the issue left sub tree +might write some stuff that didn't get + + align:start position:0% +might write some stuff that didn't get + + + align:start position:0% +might write some stuff that didn't get +re read by verify sum so now you go to + + align:start position:0% +re read by verify sum so now you go to + + + align:start position:0% +re read by verify sum so now you go to +read it you need to know am I reading + + align:start position:0% +read it you need to know am I reading + + + align:start position:0% +read it you need to know am I reading +something that was not in our intersect + + align:start position:0% +something that was not in our intersect + + + align:start position:0% +something that was not in our intersect +W and therefore uh + + align:start position:0% +W and therefore uh + + + align:start position:0% +W and therefore uh +yeah basically the issue is is it in + + align:start position:0% +yeah basically the issue is is it in + + + align:start position:0% +yeah basically the issue is is it in +W if it's in W but not in R intersect W + + align:start position:0% +W if it's in W but not in R intersect W + + + align:start position:0% +W if it's in W but not in R intersect W +then I know the answer is no should stop + + align:start position:0% +then I know the answer is no should stop + + + align:start position:0% +then I know the answer is no should stop +if it's not in W though that means it + + align:start position:0% +if it's not in W though that means it + + + align:start position:0% +if it's not in W though that means it +was in the known past and then I should + + align:start position:0% +was in the known past and then I should + + + align:start position:0% +was in the known past and then I should +continue how do I know whether I should + + align:start position:0% +continue how do I know whether I should + + + align:start position:0% +continue how do I know whether I should +stop or continue + + align:start position:0% +stop or continue + + + align:start position:0% +stop or continue +so uh this is the tricky + + align:start position:0% +so uh this is the tricky + + + align:start position:0% +so uh this is the tricky +part we can't + + align:start position:0% + + + + align:start position:0% + +tell whether here's the weird + + align:start position:0% +tell whether here's the weird + + + align:start position:0% +tell whether here's the weird +notation we want to know whether R is in + + align:start position:0% +notation we want to know whether R is in + + + align:start position:0% +notation we want to know whether R is in +wus + + align:start position:0% +wus + + + align:start position:0% +wus +r or + + align:start position:0% +r or + + + align:start position:0% +r or +past minus r inter + + align:start position:0% +past minus r inter + + + align:start position:0% +past minus r inter +W okay we know we can tell whether it's + + align:start position:0% +W okay we know we can tell whether it's + + + align:start position:0% +W okay we know we can tell whether it's +in R intersect W if it is we're happy if + + align:start position:0% +in R intersect W if it is we're happy if + + + align:start position:0% +in R intersect W if it is we're happy if +it's not in R intersect W it could be + + align:start position:0% +it's not in R intersect W it could be + + + align:start position:0% +it's not in R intersect W it could be +that's because it was just in some past + + align:start position:0% +that's because it was just in some past + + + align:start position:0% +that's because it was just in some past +thing we were reading uh that didn't get + + align:start position:0% +thing we were reading uh that didn't get + + + align:start position:0% +thing we were reading uh that didn't get +read other read otherwise or it could be + + align:start position:0% +read other read otherwise or it could be + + + align:start position:0% +read other read otherwise or it could be +something we're reading something that + + align:start position:0% +something we're reading something that + + + align:start position:0% +something we're reading something that +was written in the left subtree but not + + align:start position:0% +was written in the left subtree but not + + + align:start position:0% +was written in the left subtree but not +read in the right subtree so in this + + align:start position:0% +read in the right subtree so in this + + + align:start position:0% +read in the right subtree so in this +case we want to + + align:start position:0% +case we want to + + + align:start position:0% +case we want to +abort and in this case uh it's known and + + align:start position:0% +abort and in this case uh it's known and + + + align:start position:0% +abort and in this case uh it's known and +so we just + + align:start position:0% + + + + align:start position:0% + +continue so that's what the simulation + + align:start position:0% +continue so that's what the simulation + + + align:start position:0% +continue so that's what the simulation +would like to do if we could distinguish + + align:start position:0% +would like to do if we could distinguish + + + align:start position:0% +would like to do if we could distinguish +between these two + + align:start position:0% +between these two + + + align:start position:0% +between these two +cases but right now we can't distinguish + + align:start position:0% +cases but right now we can't distinguish + + + align:start position:0% +cases but right now we can't distinguish +between these two cases because we don't + + align:start position:0% +between these two cases because we don't + + + align:start position:0% +between these two cases because we don't +have enough information so we're going + + align:start position:0% +have enough information so we're going + + + align:start position:0% +have enough information so we're going +to make our encoding a little bit + + align:start position:0% +to make our encoding a little bit + + + align:start position:0% +to make our encoding a little bit +bigger what we're going to + + align:start position:0% + + + + align:start position:0% + +do this is over + + align:start position:0% + + + + align:start position:0% + +here is in code a + + align:start position:0% + + + + align:start position:0% + +separator for Rus + + align:start position:0% + + + + align:start position:0% + +W and wus + + align:start position:0% +W and wus + + + align:start position:0% +W and wus +R so + + align:start position:0% + + + + align:start position:0% + +let's go over + + align:start position:0% + + + + align:start position:0% + +here + + align:start position:0% + + + + align:start position:0% + +what does this mean separator is going + + align:start position:0% +what does this mean separator is going + + + align:start position:0% +what does this mean separator is going +to call called the + + align:start position:0% +to call called the + + + align:start position:0% +to call called the +S so I want this picture R minus + + align:start position:0% +S so I want this picture R minus + + + align:start position:0% +S so I want this picture R minus +W sits inside + + align:start position:0% +W sits inside + + + align:start position:0% +W sits inside +S and wus R sits outside s so this is my + + align:start position:0% +S and wus R sits outside s so this is my + + + align:start position:0% +S and wus R sits outside s so this is my +universe of + + align:start position:0% +universe of + + + align:start position:0% +universe of +cells these are the things that are read + + align:start position:0% +cells these are the things that are read + + + align:start position:0% +cells these are the things that are read +in the right sub tree but not written in + + align:start position:0% +in the right sub tree but not written in + + + align:start position:0% +in the right sub tree but not written in +the left sub tree those are the things I + + align:start position:0% +the left sub tree those are the things I + + + align:start position:0% +the left sub tree those are the things I +care + + align:start position:0% +care + + + align:start position:0% +care +about + + align:start position:0% +about + + + align:start position:0% +about +uh well not quite this the other ones so + + align:start position:0% +uh well not quite this the other ones so + + + align:start position:0% +uh well not quite this the other ones so +things that are read in the right sub + + align:start position:0% +things that are read in the right sub + + + align:start position:0% +things that are read in the right sub +tree and that are not written in the + + align:start position:0% +tree and that are not written in the + + + align:start position:0% +tree and that are not written in the +left sub tree this is the past + + align:start position:0% +left sub tree this is the past + + + align:start position:0% +left sub tree this is the past +essentially that that's useful over + + align:start position:0% +essentially that that's useful over + + + align:start position:0% +essentially that that's useful over +there over here I have uh wus R these + + align:start position:0% +there over here I have uh wus R these + + + align:start position:0% +there over here I have uh wus R these +are things that are written in the left + + align:start position:0% +are things that are written in the left + + + align:start position:0% +are things that are written in the left +sub tree but not read in the right sub + + align:start position:0% +sub tree but not read in the right sub + + + align:start position:0% +sub tree but not read in the right sub +tree these are the things that I worry + + align:start position:0% +tree these are the things that I worry + + + align:start position:0% +tree these are the things that I worry +about because those ones I need to + + align:start position:0% +about because those ones I need to + + + align:start position:0% +about because those ones I need to +detect that that was changed and say + + align:start position:0% +detect that that was changed and say + + + align:start position:0% +detect that that was changed and say +whoops um you must have an answer of + + align:start position:0% +whoops um you must have an answer of + + + align:start position:0% +whoops um you must have an answer of +no okay so I can't afford to store these + + align:start position:0% +no okay so I can't afford to store these + + + align:start position:0% +no okay so I can't afford to store these +sets exactly so I'm going to approximate + + align:start position:0% +sets exactly so I'm going to approximate + + + align:start position:0% +sets exactly so I'm going to approximate +them by saying well let's store this + + align:start position:0% +them by saying well let's store this + + + align:start position:0% +them by saying well let's store this +separator out + + align:start position:0% +separator out + + + align:start position:0% +separator out +here uh and if you're in s then you're + + align:start position:0% +here uh and if you're in s then you're + + + align:start position:0% +here uh and if you're in s then you're +definitely not in wus R if you're + + align:start position:0% +definitely not in wus R if you're + + + align:start position:0% +definitely not in wus R if you're +definitely not in wus R then you can run + + align:start position:0% +definitely not in wus R then you can run + + + align:start position:0% +definitely not in wus R then you can run +you can treat it as if if it was + + align:start position:0% +you can treat it as if if it was + + + align:start position:0% +you can treat it as if if it was +known okay so if you're in s this will + + align:start position:0% +known okay so if you're in s this will + + + align:start position:0% +known okay so if you're in s this will +be well why don't I write it + + align:start position:0% +be well why don't I write it + + + align:start position:0% +be well why don't I write it +here uh for the decoding algorithm if + + align:start position:0% +here uh for the decoding algorithm if + + + align:start position:0% +here uh for the decoding algorithm if +you want to read a + + align:start position:0% +you want to read a + + + align:start position:0% +you want to read a +cell that + + align:start position:0% +cell that + + + align:start position:0% +cell that +is uh + + align:start position:0% + + + + align:start position:0% + +written or last written + + align:start position:0% + + + + align:start position:0% + +in right + + align:start position:0% + + + + align:start position:0% + +subtree in the past the these are the + + align:start position:0% +subtree in the past the these are the + + + align:start position:0% +subtree in the past the these are the +two easy + + align:start position:0% +two easy + + + align:start position:0% +two easy +cases um sorry in I don't want to write + + align:start position:0% +cases um sorry in I don't want to write + + + align:start position:0% +cases um sorry in I don't want to write +in the past because the whole point is + + align:start position:0% +in the past because the whole point is + + + align:start position:0% +in the past because the whole point is +to figure out what's in the past uh the + + align:start position:0% +to figure out what's in the past uh the + + + align:start position:0% +to figure out what's in the past uh the +other easy case is if it's in R + + align:start position:0% +other easy case is if it's in R + + + align:start position:0% +other easy case is if it's in R +intersect W then it's written down for + + align:start position:0% +intersect W then it's written down for + + + align:start position:0% +intersect W then it's written down for +us so this is + + align:start position:0% +us so this is + + + align:start position:0% +us so this is +encoded uh this is easy because during + + align:start position:0% +encoded uh this is easy because during + + + align:start position:0% +encoded uh this is easy because during +the simulation we did those rights and + + align:start position:0% +the simulation we did those rights and + + + align:start position:0% +the simulation we did those rights and +so we know what they were uh R intersect + + align:start position:0% +so we know what they were uh R intersect + + + align:start position:0% +so we know what they were uh R intersect +W we've written down so it's easy to + + align:start position:0% +W we've written down so it's easy to + + + align:start position:0% +W we've written down so it's easy to +know then the other cases are either + + align:start position:0% +know then the other cases are either + + + align:start position:0% +know then the other cases are either +you're in s or you're not in s + + align:start position:0% + + + + align:start position:0% + +okay I claim if you're in s you must be + + align:start position:0% +okay I claim if you're in s you must be + + + align:start position:0% +okay I claim if you're in s you must be +in the + + align:start position:0% +in the + + + align:start position:0% +in the +past that cell must have been written in + + align:start position:0% +past that cell must have been written in + + + align:start position:0% +past that cell must have been written in +the + + align:start position:0% +the + + + align:start position:0% +the +past and so you know what the value + + align:start position:0% +past and so you know what the value + + + align:start position:0% +past and so you know what the value +was and so you can continue running the + + align:start position:0% +was and so you can continue running the + + + align:start position:0% +was and so you can continue running the +simulation just like in this + + align:start position:0% + + + + align:start position:0% + +situation the other situation is you're + + align:start position:0% +situation the other situation is you're + + + align:start position:0% +situation the other situation is you're +not in s then you don't know it could + + align:start position:0% +not in s then you don't know it could + + + align:start position:0% +not in s then you don't know it could +have been written or it might not have + + align:start position:0% +have been written or it might not have + + + align:start position:0% +have been written or it might not have +been + + align:start position:0% +been + + + align:start position:0% +been +but what you know is that you're + + align:start position:0% +but what you know is that you're + + + align:start position:0% +but what you know is that you're +definitely not in + + align:start position:0% +definitely not in + + + align:start position:0% +definitely not in +R because if you're not in R minus W and + + align:start position:0% +R because if you're not in R minus W and + + + align:start position:0% +R because if you're not in R minus W and +you're not in R intersect W then you're + + align:start position:0% +you're not in R intersect W then you're + + + align:start position:0% +you're not in R intersect W then you're +not in R if you're not in R then we're + + align:start position:0% +not in R if you're not in R then we're + + + align:start position:0% +not in R if you're not in R then we're +in this situation if you read something + + align:start position:0% +in this situation if you read something + + + align:start position:0% +in this situation if you read something +not an r that means you're running the + + align:start position:0% +not an r that means you're running the + + + align:start position:0% +not an r that means you're running the +wrong query because the correct query + + align:start position:0% +wrong query because the correct query + + + align:start position:0% +wrong query because the correct query +does r only reads from R so if you're + + align:start position:0% +does r only reads from R so if you're + + + align:start position:0% +does r only reads from R so if you're +not an S you must not be in + + align:start position:0% +not an S you must not be in + + + align:start position:0% +not an S you must not be in +R and so in this case you know you can + + align:start position:0% +R and so in this case you know you can + + + align:start position:0% +R and so in this case you know you can +abort and try the next Pi so we're going + + align:start position:0% +abort and try the next Pi so we're going + + + align:start position:0% +abort and try the next Pi so we're going +to do this for all Pi run the simulation + + align:start position:0% +to do this for all Pi run the simulation + + + align:start position:0% +to do this for all Pi run the simulation +according to this way of reading + + align:start position:0% +according to this way of reading + + + align:start position:0% +according to this way of reading +cells at the end the query is either + + align:start position:0% +cells at the end the query is either + + + align:start position:0% +cells at the end the query is either +going to say yes or no or it may uh + + align:start position:0% +going to say yes or no or it may uh + + + align:start position:0% +going to say yes or no or it may uh +abort + + align:start position:0% +abort + + + align:start position:0% +abort +early so if it says no or it aborts + + align:start position:0% +early so if it says no or it aborts + + + align:start position:0% +early so if it says no or it aborts +early then we know that was not the + + align:start position:0% +early then we know that was not the + + + align:start position:0% +early then we know that was not the +right P only one of them can say yes + + align:start position:0% +right P only one of them can say yes + + + align:start position:0% +right P only one of them can say yes +that tells what the pi is that tells us + + align:start position:0% +that tells what the pi is that tells us + + + align:start position:0% +that tells what the pi is that tells us +what the queries were once we know what + + align:start position:0% +what the queries were once we know what + + + align:start position:0% +what the queries were once we know what +the queries were in the right sube we + + align:start position:0% +the queries were in the right sube we + + + align:start position:0% +the queries were in the right sube we +can use the same multiplying by inverses + + align:start position:0% +can use the same multiplying by inverses + + + align:start position:0% +can use the same multiplying by inverses +trick figure out what the updates were + + align:start position:0% +trick figure out what the updates were + + + align:start position:0% +trick figure out what the updates were +in the left sub tree but the those + + align:start position:0% +in the left sub tree but the those + + + align:start position:0% +in the left sub tree but the those +permutations require L root n log n Bits + + align:start position:0% +permutations require L root n log n Bits + + + align:start position:0% +permutations require L root n log n Bits +which used to be on this board an erase + + align:start position:0% +which used to be on this board an erase + + + align:start position:0% +which used to be on this board an erase +now that's what we use for this + + align:start position:0% +now that's what we use for this + + + align:start position:0% +now that's what we use for this +argument and so what we get is overall + + align:start position:0% +argument and so what we get is overall + + + align:start position:0% +argument and so what we get is overall +encoding must use l root n log n + + align:start position:0% +encoding must use l root n log n + + + align:start position:0% +encoding must use l root n log n +Bits okay but our encodings a little bit + + align:start position:0% +Bits okay but our encodings a little bit + + + align:start position:0% +Bits okay but our encodings a little bit +bigger now the big issue is how do we + + align:start position:0% +bigger now the big issue is how do we + + + align:start position:0% +bigger now the big issue is how do we +store this separator we need to do store + + align:start position:0% +store this separator we need to do store + + + align:start position:0% +store this separator we need to do store +the separator with very few bits + + align:start position:0% +the separator with very few bits + + + align:start position:0% +the separator with very few bits +otherwise uh doesn't we don't haven't + + align:start position:0% +otherwise uh doesn't we don't haven't + + + align:start position:0% +otherwise uh doesn't we don't haven't +really proved anything we want the + + align:start position:0% +really proved anything we want the + + + align:start position:0% +really proved anything we want the +encoding to be + + align:start position:0% +encoding to be + + + align:start position:0% +encoding to be +small + + align:start position:0% +small + + + align:start position:0% +small +so uh so we get that the + + align:start position:0% +so uh so we get that the + + + align:start position:0% +so uh so we get that the +encoding must + + align:start position:0% + + + + align:start position:0% + +use Omega L root n log n Bits in + + align:start position:0% +use Omega L root n log n Bits in + + + align:start position:0% +use Omega L root n log n Bits in +expectation + + align:start position:0% + + + + align:start position:0% + +because this is a valid decoding + + align:start position:0% +because this is a valid decoding + + + align:start position:0% +because this is a valid decoding +algorithm it will figure out what the + + align:start position:0% +algorithm it will figure out what the + + + align:start position:0% +algorithm it will figure out what the +permutations were so and they require at + + align:start position:0% +permutations were so and they require at + + + align:start position:0% +permutations were so and they require at +least this many bits so encoding must + + align:start position:0% +least this many bits so encoding must + + + align:start position:0% +least this many bits so encoding must +use this many bits in expectation now + + align:start position:0% +use this many bits in expectation now + + + align:start position:0% +use this many bits in expectation now +the question is how many bits does the + + align:start position:0% +the question is how many bits does the + + + align:start position:0% +the question is how many bits does the +encoding use then we'll get either a + + align:start position:0% +encoding use then we'll get either a + + + align:start position:0% +encoding use then we'll get either a +contradiction or we'll prove the prove + + align:start position:0% +contradiction or we'll prove the prove + + + align:start position:0% +contradiction or we'll prove the prove +the + + align:start position:0% +the + + + align:start position:0% +the +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +claim so let's go over + + align:start position:0% + + + + align:start position:0% + +here + + align:start position:0% + + + + align:start position:0% + +so here's a fun fact about separators + + align:start position:0% +so here's a fun fact about separators + + + align:start position:0% +so here's a fun fact about separators +I'm not going to prove it fully but I'm + + align:start position:0% +I'm not going to prove it fully but I'm + + + align:start position:0% +I'm not going to prove it fully but I'm +going to rely on some hashing + + align:start position:0% + + + + align:start position:0% + +ability so given some Universe u in this + + align:start position:0% +ability so given some Universe u in this + + + align:start position:0% +ability so given some Universe u in this +case it's going to be the cells in our + + align:start position:0% +case it's going to be the cells in our + + + align:start position:0% +case it's going to be the cells in our +data structure but speak a little bit + + align:start position:0% +data structure but speak a little bit + + + align:start position:0% +data structure but speak a little bit +more generally of universe U we have + + align:start position:0% +more generally of universe U we have + + + align:start position:0% +more generally of universe U we have +some number M which is our set size and + + align:start position:0% +some number M which is our set size and + + + align:start position:0% +some number M which is our set size and +what we're interested is in defining we + + align:start position:0% +what we're interested is in defining we + + + align:start position:0% +what we're interested is in defining we +call a separator family + + align:start position:0% +call a separator family + + + align:start position:0% +call a separator family +kind of like a family of hash + + align:start position:0% +kind of like a family of hash + + + align:start position:0% +kind of like a family of hash +functions closely related in fact call + + align:start position:0% +functions closely related in fact call + + + align:start position:0% +functions closely related in fact call +it + + align:start position:0% +it + + + align:start position:0% +it +s + + align:start position:0% +s + + + align:start position:0% +s +uh and it's going to work for size M + + align:start position:0% + + + + align:start position:0% + +sets uh and so s is a separator family + + align:start position:0% +sets uh and so s is a separator family + + + align:start position:0% +sets uh and so s is a separator family +if uh for any two sets A and + + align:start position:0% +if uh for any two sets A and + + + align:start position:0% +if uh for any two sets A and +B in the + + align:start position:0% +B in the + + + align:start position:0% +B in the +universe of size at most + + align:start position:0% + + + + align:start position:0% + +M uh and + + align:start position:0% +M uh and + + + align:start position:0% +M uh and +disjoint so a intersect B is the empty + + align:start position:0% +disjoint so a intersect B is the empty + + + align:start position:0% +disjoint so a intersect B is the empty +set so of course what we're thinking + + align:start position:0% +set so of course what we're thinking + + + align:start position:0% +set so of course what we're thinking +about here is R minus W and wus R these + + align:start position:0% +about here is R minus W and wus R these + + + align:start position:0% +about here is R minus W and wus R these +are two subsets of the universe + + align:start position:0% +are two subsets of the universe + + + align:start position:0% +are two subsets of the universe +hopefully they're not too big because if + + align:start position:0% +hopefully they're not too big because if + + + align:start position:0% +hopefully they're not too big because if +this one's huge that means you read a + + align:start position:0% +this one's huge that means you read a + + + align:start position:0% +this one's huge that means you read a +huge amount of data in the right sub + + align:start position:0% +huge amount of data in the right sub + + + align:start position:0% +huge amount of data in the right sub +tree if this one is huge it meant you + + align:start position:0% +tree if this one is huge it meant you + + + align:start position:0% +tree if this one is huge it meant you +wrote a huge amount of data on the left + + align:start position:0% +wrote a huge amount of data on the left + + + align:start position:0% +wrote a huge amount of data on the left +sub tree and then we get lower bounds in + + align:start position:0% +sub tree and then we get lower bounds in + + + align:start position:0% +sub tree and then we get lower bounds in +an easier way or or they're not so big + + align:start position:0% +an easier way or or they're not so big + + + align:start position:0% +an easier way or or they're not so big +it's say their size at most M they're + + align:start position:0% +it's say their size at most M they're + + + align:start position:0% +it's say their size at most M they're +disjoint for sure by definition Rus W is + + align:start position:0% +disjoint for sure by definition Rus W is + + + align:start position:0% +disjoint for sure by definition Rus W is +disjoint from wus R you removes the + + align:start position:0% +disjoint from wus R you removes the + + + align:start position:0% +disjoint from wus R you removes the +intersection + + align:start position:0% +intersection + + + align:start position:0% +intersection +uh so that's our + + align:start position:0% +uh so that's our + + + align:start position:0% +uh so that's our +setup then what we want is that there is + + align:start position:0% +setup then what we want is that there is + + + align:start position:0% +setup then what we want is that there is +some set C in the separator + + align:start position:0% +some set C in the separator + + + align:start position:0% +some set C in the separator +family such + + align:start position:0% + + + + align:start position:0% + +that + + align:start position:0% +that + + + align:start position:0% +that +uh a is contained in C and B is outside + + align:start position:0% +uh a is contained in C and B is outside + + + align:start position:0% +uh a is contained in C and B is outside +of + + align:start position:0% + + + + align:start position:0% + +C so B is in the universe minus C so + + align:start position:0% +C so B is in the universe minus C so + + + align:start position:0% +C so B is in the universe minus C so +this is exactly our picture from before + + align:start position:0% +this is exactly our picture from before + + + align:start position:0% +this is exactly our picture from before +we have a a contains C and we have B + + align:start position:0% +we have a a contains C and we have B + + + align:start position:0% +we have a a contains C and we have B +over on the right and this is the whole + + align:start position:0% +over on the right and this is the whole + + + align:start position:0% +over on the right and this is the whole +universe U and so B is outside of c a is + + align:start position:0% +universe U and so B is outside of c a is + + + align:start position:0% +universe U and so B is outside of c a is +entirely inside + + align:start position:0% +entirely inside + + + align:start position:0% +entirely inside +C + + align:start position:0% +C + + + align:start position:0% +C +okay this is what we want to exist cuz + + align:start position:0% +okay this is what we want to exist cuz + + + align:start position:0% +okay this is what we want to exist cuz +if a separator family exists then we + + align:start position:0% +if a separator family exists then we + + + align:start position:0% +if a separator family exists then we +know whatever our Rus W and wus R sets + + align:start position:0% +know whatever our Rus W and wus R sets + + + align:start position:0% +know whatever our Rus W and wus R sets +were as long as they're not too big + + align:start position:0% +were as long as they're not too big + + + align:start position:0% +were as long as they're not too big +they're definitely disjoint we can find + + align:start position:0% +they're definitely disjoint we can find + + + align:start position:0% +they're definitely disjoint we can find +one of these separators that encodes + + align:start position:0% +one of these separators that encodes + + + align:start position:0% +one of these separators that encodes +what we need to encode which is this set + + align:start position:0% +what we need to encode which is this set + + + align:start position:0% +what we need to encode which is this set +C which is called uh s over + + align:start position:0% +C which is called uh s over + + + align:start position:0% +C which is called uh s over +there cool uh how do we encode it well + + align:start position:0% +there cool uh how do we encode it well + + + align:start position:0% +there cool uh how do we encode it well +if this if the number if the + + align:start position:0% +if this if the number if the + + + align:start position:0% +if this if the number if the +size of the separator family is + + align:start position:0% +size of the separator family is + + + align:start position:0% +size of the separator family is +something then we need log of that bits + + align:start position:0% +something then we need log of that bits + + + align:start position:0% +something then we need log of that bits +to write down the separator said so as + + align:start position:0% +to write down the separator said so as + + + align:start position:0% +to write down the separator said so as +long as this is small we're + + align:start position:0% +long as this is small we're + + + align:start position:0% +long as this is small we're +happy so uh let me tell you what's not + + align:start position:0% +happy so uh let me tell you what's not + + + align:start position:0% +happy so uh let me tell you what's not +about + + align:start position:0% + + + + align:start position:0% + +separators uh there exists a separator + + align:start position:0% +separators uh there exists a separator + + + align:start position:0% +separators uh there exists a separator +family + + align:start position:0% +family + + + align:start position:0% +family +s with size of + + align:start position:0% +s with size of + + + align:start position:0% +s with size of +s at most 2 to the order m + log log + + align:start position:0% +s at most 2 to the order m + log log + + + align:start position:0% +s at most 2 to the order m + log log +U now this is getting into an area that + + align:start position:0% +U now this is getting into an area that + + + align:start position:0% +U now this is getting into an area that +we haven't spent a lot of time on uh but + + align:start position:0% +we haven't spent a lot of time on uh but + + + align:start position:0% +we haven't spent a lot of time on uh but +so I'm going to give you a sketch of a + + align:start position:0% +so I'm going to give you a sketch of a + + + align:start position:0% +so I'm going to give you a sketch of a +proof of this + + align:start position:0% + + + + align:start position:0% + +claim relying on perfect hash + + align:start position:0% +claim relying on perfect hash + + + align:start position:0% +claim relying on perfect hash +functions so + + align:start position:0% +functions so + + + align:start position:0% +functions so +the idea is the following we want to + + align:start position:0% +the idea is the following we want to + + + align:start position:0% +the idea is the following we want to +know basically which elements are in a + + align:start position:0% +know basically which elements are in a + + + align:start position:0% +know basically which elements are in a +which elements are in B but it's kind of + + align:start position:0% +which elements are in B but it's kind of + + + align:start position:0% +which elements are in B but it's kind of +annoying to do that you can't store that + + align:start position:0% +annoying to do that you can't store that + + + align:start position:0% +annoying to do that you can't store that +for all Universe elements so if we could + + align:start position:0% +for all Universe elements so if we could + + + align:start position:0% +for all Universe elements so if we could +just find a nice perfect hash function + + align:start position:0% +just find a nice perfect hash function + + + align:start position:0% +just find a nice perfect hash function +that mapped the elements of a and the + + align:start position:0% +that mapped the elements of a and the + + + align:start position:0% +that mapped the elements of a and the +elements of B to different slots in some + + align:start position:0% +elements of B to different slots in some + + + align:start position:0% +elements of B to different slots in some +hash table then for every slot in the + + align:start position:0% +hash table then for every slot in the + + + align:start position:0% +hash table then for every slot in the +hash table we could say is it in a or is + + align:start position:0% +hash table we could say is it in a or is + + + align:start position:0% +hash table we could say is it in a or is +it in B now if you not in a union B and + + align:start position:0% +it in B now if you not in a union B and + + + align:start position:0% +it in B now if you not in a union B and +you hash somewhere I mean you'll get + + align:start position:0% +you hash somewhere I mean you'll get + + + align:start position:0% +you hash somewhere I mean you'll get +some bit who knows what that bit stores + + align:start position:0% +some bit who knows what that bit stores + + + align:start position:0% +some bit who knows what that bit stores +I don't care I don't for for the things + + align:start position:0% +I don't care I don't for for the things + + + align:start position:0% +I don't care I don't for for the things +outside of a union B they could be in C + + align:start position:0% +outside of a union B they could be in C + + + align:start position:0% +outside of a union B they could be in C +or not in C I don't really care and so + + align:start position:0% +or not in C I don't really care and so + + + align:start position:0% +or not in C I don't really care and so +uh all I care about is that a and b have + + align:start position:0% +uh all I care about is that a and b have + + + align:start position:0% +uh all I care about is that a and b have +no + + align:start position:0% +no + + + align:start position:0% +no +collisions between each other I don't + + align:start position:0% +collisions between each other I don't + + + align:start position:0% +collisions between each other I don't +want any a thing to Hash to a b thing + + align:start position:0% +want any a thing to Hash to a b thing + + + align:start position:0% +want any a thing to Hash to a b thing +then I can store a bit in every cell in + + align:start position:0% +then I can store a bit in every cell in + + + align:start position:0% +then I can store a bit in every cell in +the hash table and that will tell me in + + align:start position:0% +the hash table and that will tell me in + + + align:start position:0% +the hash table and that will tell me in +particular a versus B and then the rest + + align:start position:0% +particular a versus B and then the rest + + + align:start position:0% +particular a versus B and then the rest +of the items are somehow categorized but + + align:start position:0% +of the items are somehow categorized but + + + align:start position:0% +of the items are somehow categorized but +I don't care how they're + + align:start position:0% +I don't care how they're + + + align:start position:0% +I don't care how they're +categorized so going to use this fact + + align:start position:0% +categorized so going to use this fact + + + align:start position:0% +categorized so going to use this fact +that there is a set of perfect hash + + align:start position:0% +that there is a set of perfect hash + + + align:start position:0% +that there is a set of perfect hash +functions + + align:start position:0% + + + + align:start position:0% + +of the same + + align:start position:0% +of the same + + + align:start position:0% +of the same +size + + align:start position:0% + + + + align:start position:0% + +uh sorry that should be + + align:start position:0% + + + + align:start position:0% + +H this is what's really + + align:start position:0% +H this is what's really + + + align:start position:0% +H this is what's really +true size of H is 2 to the order m+ log + + align:start position:0% +true size of H is 2 to the order m+ log + + + align:start position:0% +true size of H is 2 to the order m+ log +log + + align:start position:0% +log + + + align:start position:0% +log +U okay I'm not going to prove this but + + align:start position:0% +U okay I'm not going to prove this but + + + align:start position:0% +U okay I'm not going to prove this but +this is about succinct hash functions + + align:start position:0% +this is about succinct hash functions + + + align:start position:0% +this is about succinct hash functions +may be hard to find such a hash family + + align:start position:0% +may be hard to find such a hash family + + + align:start position:0% +may be hard to find such a hash family +but the claim is there they exist or + + align:start position:0% +but the claim is there they exist or + + + align:start position:0% +but the claim is there they exist or +it's hard to find the hash function in + + align:start position:0% +it's hard to find the hash function in + + + align:start position:0% +it's hard to find the hash function in +the family that has no collisions but + + align:start position:0% +the family that has no collisions but + + + align:start position:0% +the family that has no collisions but +the guarantee is as long as you have uh + + align:start position:0% +the guarantee is as long as you have uh + + + align:start position:0% +the guarantee is as long as you have uh +I guess in total 2 m items out of your + + align:start position:0% +I guess in total 2 m items out of your + + + align:start position:0% +I guess in total 2 m items out of your +univers of size U uh you can get a + + align:start position:0% +univers of size U uh you can get a + + + align:start position:0% +univers of size U uh you can get a +collision free hash function 2 to the + + align:start position:0% +collision free hash function 2 to the + + + align:start position:0% +collision free hash function 2 to the +order M plus log log + + align:start position:0% +order M plus log log + + + align:start position:0% +order M plus log log +U okay so this is going to um + + align:start position:0% +U okay so this is going to um + + + align:start position:0% +U okay so this is going to um +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +Maps say a union B to an order M size + + align:start position:0% + + + + align:start position:0% + +table and here there are no + + align:start position:0% + + + + align:start position:0% + +collisions so then what we also + + align:start position:0% +collisions so then what we also + + + align:start position:0% +collisions so then what we also +store is an A or B + + align:start position:0% + + + + align:start position:0% + +bit uh for each table + + align:start position:0% +bit uh for each table + + + align:start position:0% +bit uh for each table +entry + + align:start position:0% + + + + align:start position:0% + +uh so that's our encoding we store a + + align:start position:0% +uh so that's our encoding we store a + + + align:start position:0% +uh so that's our encoding we store a +hash fun perfect hash function uh that's + + align:start position:0% +hash fun perfect hash function uh that's + + + align:start position:0% +hash fun perfect hash function uh that's +going to cost you know log H + + align:start position:0% + + + + align:start position:0% + +bits for this part and log of H is just + + align:start position:0% +bits for this part and log of H is just + + + align:start position:0% +bits for this part and log of H is just +M plus log log U and then we're going to + + align:start position:0% +M plus log log U and then we're going to + + + align:start position:0% +M plus log log U and then we're going to +store this A or B uh B for every table + + align:start position:0% +store this A or B uh B for every table + + + align:start position:0% +store this A or B uh B for every table +entry the number of table entries is + + align:start position:0% +entry the number of table entries is + + + align:start position:0% +entry the number of table entries is +order M so this is going to take 2 to + + align:start position:0% +order M so this is going to take 2 to + + + align:start position:0% +order M so this is going to take 2 to +the order + + align:start position:0% +the order + + + align:start position:0% +the order +M bits or sorry not uh sorry terms of + + align:start position:0% +M bits or sorry not uh sorry terms of + + + align:start position:0% +M bits or sorry not uh sorry terms of +bits it's order M bits I should + + align:start position:0% + + + + align:start position:0% + +say in terms of functions it's uh you + + align:start position:0% +say in terms of functions it's uh you + + + align:start position:0% +say in terms of functions it's uh you +know two to the order M possible choices + + align:start position:0% +know two to the order M possible choices + + + align:start position:0% +know two to the order M possible choices +for this bit vector and so uh the easy + + align:start position:0% +for this bit vector and so uh the easy + + + align:start position:0% +for this bit vector and so uh the easy +way is to just sum up these bits you use + + align:start position:0% +way is to just sum up these bits you use + + + align:start position:0% +way is to just sum up these bits you use +log of H bits plus order M bits this + + align:start position:0% +log of H bits plus order M bits this + + + align:start position:0% +log of H bits plus order M bits this +already had an order M term and so you + + align:start position:0% +already had an order M term and so you + + + align:start position:0% +already had an order M term and so you +get this that log of s is order M plus + + align:start position:0% +get this that log of s is order M plus + + + align:start position:0% +get this that log of s is order M plus +log log + + align:start position:0% +log log + + + align:start position:0% +log log +U okay so that's the end of proof sketch + + align:start position:0% +U okay so that's the end of proof sketch + + + align:start position:0% +U okay so that's the end of proof sketch +of the claim if you believe perfect hash + + align:start position:0% +of the claim if you believe perfect hash + + + align:start position:0% +of the claim if you believe perfect hash +functions can be written down in small + + align:start position:0% +functions can be written down in small + + + align:start position:0% +functions can be written down in small +way then we're done now for with + + align:start position:0% +way then we're done now for with + + + align:start position:0% +way then we're done now for with +separators now let's apply this + + align:start position:0% +separators now let's apply this + + + align:start position:0% +separators now let's apply this +separator theorem claim to this + + align:start position:0% +separator theorem claim to this + + + align:start position:0% +separator theorem claim to this +setting so now we can compute the size + + align:start position:0% +setting so now we can compute the size + + + align:start position:0% +setting so now we can compute the size +of our en coding our encoding involves + + align:start position:0% +of our en coding our encoding involves + + + align:start position:0% +of our en coding our encoding involves +writing down R intersect W that takes R + + align:start position:0% +writing down R intersect W that takes R + + + align:start position:0% +writing down R intersect W that takes R +intersect W * log n just like + + align:start position:0% +intersect W * log n just like + + + align:start position:0% +intersect W * log n just like +before uh it also + + align:start position:0% +before uh it also + + + align:start position:0% +before uh it also +involves uh writing down the separator + + align:start position:0% +involves uh writing down the separator + + + align:start position:0% +involves uh writing down the separator +separator takes order M bits m is r+ + + align:start position:0% +separator takes order M bits m is r+ + + + align:start position:0% +separator takes order M bits m is r+ +W things that are its order R plus W + + align:start position:0% +W things that are its order R plus W + + + align:start position:0% +W things that are its order R plus W +these are all the things trying to write + + align:start position:0% +these are all the things trying to write + + + align:start position:0% +these are all the things trying to write +down Rus W and wus R so that you add up + + align:start position:0% +down Rus W and wus R so that you add up + + + align:start position:0% +down Rus W and wus R so that you add up +those sizes basically R plus W plus log + + align:start position:0% +those sizes basically R plus W plus log + + + align:start position:0% +those sizes basically R plus W plus log +log u u + + align:start position:0% +log u u + + + align:start position:0% +log u u +is some small thing uh size of memory + + align:start position:0% +is some small thing uh size of memory + + + align:start position:0% +is some small thing uh size of memory +number of cells in memory we're assuming + + align:start position:0% +number of cells in memory we're assuming + + + align:start position:0% +number of cells in memory we're assuming +that's polinomial so you take log log of + + align:start position:0% +that's polinomial so you take log log of + + + align:start position:0% +that's polinomial so you take log log of +a + + align:start position:0% +a + + + align:start position:0% +a +polinomial uh that's like log log + + align:start position:0% +polinomial uh that's like log log + + + align:start position:0% +polinomial uh that's like log log +n so let's finish this + + align:start position:0% + + + + align:start position:0% + +off so + + align:start position:0% + + + + align:start position:0% + +before before this was our equation R + + align:start position:0% +before before this was our equation R + + + align:start position:0% +before before this was our equation R +inter W * log n that was the size of our + + align:start position:0% +inter W * log n that was the size of our + + + align:start position:0% +inter W * log n that was the size of our +encoding we still have that + + align:start position:0% + + + + align:start position:0% + +term sorry R inter W size of + + align:start position:0% +term sorry R inter W size of + + + align:start position:0% +term sorry R inter W size of +that uh Times log n so we still do + + align:start position:0% + + + + align:start position:0% + +that now we also pay for this separator + + align:start position:0% +that now we also pay for this separator + + + align:start position:0% +that now we also pay for this separator +we're going to pay r plus + + align:start position:0% +we're going to pay r plus + + + align:start position:0% +we're going to pay r plus +W that's the M part plus log log + + align:start position:0% +W that's the M part plus log log + + + align:start position:0% +W that's the M part plus log log +n this is the number of bits in our + + align:start position:0% +n this is the number of bits in our + + + align:start position:0% +n this is the number of bits in our +encoding okay and I claim or what we + + align:start position:0% +encoding okay and I claim or what we + + + align:start position:0% +encoding okay and I claim or what we +proved over here is that any encoding + + align:start position:0% +proved over here is that any encoding + + + align:start position:0% +proved over here is that any encoding +must use l root n log n + + align:start position:0% + + + + align:start position:0% + +Bits so this thing must be at least this + + align:start position:0% +Bits so this thing must be at least this + + + align:start position:0% +Bits so this thing must be at least this +thing so we have a little bit more work + + align:start position:0% +thing so we have a little bit more work + + + align:start position:0% +thing so we have a little bit more work +to prove there are now two cases it + + align:start position:0% +to prove there are now two cases it + + + align:start position:0% +to prove there are now two cases it +depends there's basically log log n is + + align:start position:0% +depends there's basically log log n is + + + align:start position:0% +depends there's basically log log n is +unlikely to dominate we're doing a block + + align:start position:0% +unlikely to dominate we're doing a block + + + align:start position:0% +unlikely to dominate we're doing a block +operation on root N Things probably need + + align:start position:0% +operation on root N Things probably need + + + align:start position:0% +operation on root N Things probably need +to use at least log log and steps so + + align:start position:0% +to use at least log log and steps so + + + align:start position:0% +to use at least log log and steps so +that's not really relevant what will + + align:start position:0% +that's not really relevant what will + + + align:start position:0% +that's not really relevant what will +dominate is either this term as it used + + align:start position:0% +dominate is either this term as it used + + + align:start position:0% +dominate is either this term as it used +to or this term these are two different + + align:start position:0% +to or this term these are two different + + + align:start position:0% +to or this term these are two different +cases call them case one case two in + + align:start position:0% +cases call them case one case two in + + + align:start position:0% +cases call them case one case two in +case two r+ w is at least L root n log + + align:start position:0% +case two r+ w is at least L root n log + + + align:start position:0% +case two r+ w is at least L root n log +n that's the lower bound we want if we + + align:start position:0% +n that's the lower bound we want if we + + + align:start position:0% +n that's the lower bound we want if we +can in case two uh r + + + align:start position:0% +can in case two uh r + + + + align:start position:0% +can in case two uh r + +W is Omega L root n log n what that + + align:start position:0% +W is Omega L root n log n what that + + + align:start position:0% +W is Omega L root n log n what that +means is in this sub tree the amount of + + align:start position:0% +means is in this sub tree the amount of + + + align:start position:0% +means is in this sub tree the amount of +reading we did in the right sub tree + + align:start position:0% +reading we did in the right sub tree + + + align:start position:0% +reading we did in the right sub tree +plus the amount of writing we did in the + + align:start position:0% +plus the amount of writing we did in the + + + align:start position:0% +plus the amount of writing we did in the +left sub tree is at least L root n log n + + align:start position:0% +left sub tree is at least L root n log n + + + align:start position:0% +left sub tree is at least L root n log n +that's our goal over here we want to + + align:start position:0% +that's our goal over here we want to + + + align:start position:0% +that's our goal over here we want to +prove uh sorry it's a previous claim + + align:start position:0% +prove uh sorry it's a previous claim + + + align:start position:0% +prove uh sorry it's a previous claim +that's Now by now erased it's the easier + + align:start position:0% +that's Now by now erased it's the easier + + + align:start position:0% +that's Now by now erased it's the easier +claim we just want to show that the + + align:start position:0% +claim we just want to show that the + + + align:start position:0% +claim we just want to show that the +total amount of time spent in V sub + + align:start position:0% +total amount of time spent in V sub + + + align:start position:0% +total amount of time spent in V sub +is at least log n per operation we're + + align:start position:0% +is at least log n per operation we're + + + align:start position:0% +is at least log n per operation we're +doing L root N Things here so this is a + + align:start position:0% +doing L root N Things here so this is a + + + align:start position:0% +doing L root N Things here so this is a +ton of reading and writing so in that + + align:start position:0% +ton of reading and writing so in that + + + align:start position:0% +ton of reading and writing so in that +case we are happy because we get an + + align:start position:0% +case we are happy because we get an + + + align:start position:0% +case we are happy because we get an +actual lower bound on time + + align:start position:0% +actual lower bound on time + + + align:start position:0% +actual lower bound on time +otherwise uh we don't I mean these are + + align:start position:0% +otherwise uh we don't I mean these are + + + align:start position:0% +otherwise uh we don't I mean these are +actual reads and wrs or total number of + + align:start position:0% +actual reads and wrs or total number of + + + align:start position:0% +actual reads and wrs or total number of +reads and wrs here we're getting uh in + + align:start position:0% +reads and wrs here we're getting uh in + + + align:start position:0% +reads and wrs here we're getting uh in +the other case we get our intersect + + align:start position:0% + + + + align:start position:0% + +W as log n is at least L root n log n + + align:start position:0% +W as log n is at least L root n log n + + + align:start position:0% +W as log n is at least L root n log n +just like before so again the log n's + + align:start position:0% +just like before so again the log n's + + + align:start position:0% +just like before so again the log n's +cancel so here we lose a log n Factor + + align:start position:0% +cancel so here we lose a log n Factor + + + align:start position:0% +cancel so here we lose a log n Factor +but it's okay uh because this is only + + align:start position:0% +but it's okay uh because this is only + + + align:start position:0% +but it's okay uh because this is only +talking about R intersect W this we use + + align:start position:0% +talking about R intersect W this we use + + + align:start position:0% +talking about R intersect W this we use +the LCA charging say well if you look at + + align:start position:0% +the LCA charging say well if you look at + + + align:start position:0% +the LCA charging say well if you look at +a particular read it's only gets charged + + align:start position:0% +a particular read it's only gets charged + + + align:start position:0% +a particular read it's only gets charged +by the LCA so then we can afford to sum + + align:start position:0% +by the LCA so then we can afford to sum + + + align:start position:0% +by the LCA so then we can afford to sum +up lower bounds so there it's a little + + align:start position:0% +up lower bounds so there it's a little + + + align:start position:0% +up lower bounds so there it's a little +bit weird in this situation we add up + + align:start position:0% +bit weird in this situation we add up + + + align:start position:0% +bit weird in this situation we add up +all the lower bounds each of them + + align:start position:0% +all the lower bounds each of them + + + align:start position:0% +all the lower bounds each of them +doesn't give us a log n but in aggregate + + align:start position:0% +doesn't give us a log n but in aggregate + + + align:start position:0% +doesn't give us a log n but in aggregate +we get a log n because every leaf + + align:start position:0% +we get a log n because every leaf + + + align:start position:0% +we get a log n because every leaf +appears in log n levels in this case we + + align:start position:0% +appears in log n levels in this case we + + + align:start position:0% +appears in log n levels in this case we +don't need to aggregate because we just + + align:start position:0% +don't need to aggregate because we just + + + align:start position:0% +don't need to aggregate because we just +say well the number of operations in the + + align:start position:0% +say well the number of operations in the + + + align:start position:0% +say well the number of operations in the +subtree is at least log n per operation + + align:start position:0% +subtree is at least log n per operation + + + align:start position:0% +subtree is at least log n per operation +number this time spent cell probes done + + align:start position:0% +number this time spent cell probes done + + + align:start position:0% +number this time spent cell probes done +is at least log n per operation so in + + align:start position:0% +is at least log n per operation so in + + + align:start position:0% +is at least log n per operation so in +that case we don't need to sum the lower + + align:start position:0% +that case we don't need to sum the lower + + + align:start position:0% +that case we don't need to sum the lower +bounds which're is dumb so in either + + align:start position:0% +bounds which're is dumb so in either + + + align:start position:0% +bounds which're is dumb so in either +case we're happy little weird because + + align:start position:0% +case we're happy little weird because + + + align:start position:0% +case we're happy little weird because +you kind of have a mix of cases you know + + align:start position:0% +you kind of have a mix of cases you know + + + align:start position:0% +you kind of have a mix of cases you know +one vertex V could be in case two then + + align:start position:0% +one vertex V could be in case two then + + + align:start position:0% +one vertex V could be in case two then +you just ignore all the things below it + + align:start position:0% +you just ignore all the things below it + + + align:start position:0% +you just ignore all the things below it +some other the rest of the tree might be + + align:start position:0% +some other the rest of the tree might be + + + align:start position:0% +some other the rest of the tree might be +in case one but you can mix and match + + align:start position:0% +in case one but you can mix and match + + + align:start position:0% +in case one but you can mix and match +one and two as long as you uh you don't + + align:start position:0% +one and two as long as you uh you don't + + + align:start position:0% +one and two as long as you uh you don't +use a one below a two you're okay you + + align:start position:0% +use a one below a two you're okay you + + + align:start position:0% +use a one below a two you're okay you +won't double count and so in either case + + align:start position:0% +won't double count and so in either case + + + align:start position:0% +won't double count and so in either case +we're happy we get a log n lower bound + + align:start position:0% +we're happy we get a log n lower bound + + + align:start position:0% +we're happy we get a log n lower bound +either on time per operation or on this + + align:start position:0% +either on time per operation or on this + + + align:start position:0% +either on time per operation or on this +kind of time per + + align:start position:0% +kind of time per + + + align:start position:0% +kind of time per +operation add up all those lower bounds + + align:start position:0% +operation add up all those lower bounds + + + align:start position:0% +operation add up all those lower bounds +get log n per + + align:start position:0% +get log n per + + + align:start position:0% +get log n per +operation uh we get root n log n per + + align:start position:0% +operation uh we get root n log n per + + + align:start position:0% +operation uh we get root n log n per +block operation which implies log n per + + align:start position:0% +block operation which implies log n per + + + align:start position:0% +block operation which implies log n per +insert delete Edge or connectivity + + align:start position:0% +insert delete Edge or connectivity + + + align:start position:0% +insert delete Edge or connectivity +query and that proves our + + align:start position:0% +query and that proves our + + + align:start position:0% +query and that proves our +theorem more or less on time you can use + + align:start position:0% +theorem more or less on time you can use + + + align:start position:0% +theorem more or less on time you can use +the same technique to do a trade-off + + align:start position:0% +the same technique to do a trade-off + + + align:start position:0% +the same technique to do a trade-off +between updates and queries this is just + + align:start position:0% +between updates and queries this is just + + + align:start position:0% +between updates and queries this is just +log in worst case of the two I mentioned + + align:start position:0% +log in worst case of the two I mentioned + + + align:start position:0% +log in worst case of the two I mentioned +what the bound was last time same trick + + align:start position:0% +what the bound was last time same trick + + + align:start position:0% +what the bound was last time same trick +works you just do more updates than + + align:start position:0% +works you just do more updates than + + + align:start position:0% +works you just do more updates than +queries or more queries than updates so + + align:start position:0% +queries or more queries than updates so + + + align:start position:0% +queries or more queries than updates so +we get link cut trees are optimal or + + align:start position:0% +we get link cut trees are optimal or + + + align:start position:0% +we get link cut trees are optimal or +tour trees are optimal and we got lots + + align:start position:0% +tour trees are optimal and we got lots + + + align:start position:0% +tour trees are optimal and we got lots +of other points on the trade-off curve + + align:start position:0% +of other points on the trade-off curve + + + align:start position:0% +of other points on the trade-off curve +as you may recall last class like our + + align:start position:0% +as you may recall last class like our + + + align:start position:0% +as you may recall last class like our +log squared up update is optimal for a + + align:start position:0% +log squared up update is optimal for a + + + align:start position:0% +log squared up update is optimal for a +log over log log + + align:start position:0% +log over log log + + + align:start position:0% +log over log log +query and that's the end of that dynamic + + align:start position:0% +query and that's the end of that dynamic + + + align:start position:0% +query and that's the end of that dynamic +graphs in the end of advanced data + + align:start position:0% +graphs in the end of advanced data + + + align:start position:0% +graphs in the end of advanced data +structures um hope you had a fun time we + + align:start position:0% +structures um hope you had a fun time we + + + align:start position:0% +structures um hope you had a fun time we +got to see lots of different topics and + + align:start position:0% +got to see lots of different topics and + + + align:start position:0% +got to see lots of different topics and +I hope you all enjoy watching on the + + align:start position:0% +I hope you all enjoy watching on the + + + align:start position:0% +I hope you all enjoy watching on the +videos and let me know if you have any + + align:start position:0% +videos and let me know if you have any + + + align:start position:0% +videos and let me know if you have any +comments send email or + + align:start position:0% +comments send email or + + + align:start position:0% +comments send email or +whatever + + align:start position:0% +whatever + + + align:start position:0% +whatever +[Applause] + + align:start position:0% + + + + align:start position:0% + +yay \ No newline at end of file diff --git a/YegKLHb9TOU.txt b/YegKLHb9TOU.txt new file mode 100644 index 0000000000000000000000000000000000000000..7827c4a14324134462cbed9231ce3b7cd29520d3 --- /dev/null +++ b/YegKLHb9TOU.txt @@ -0,0 +1,3176 @@ +[WRITING ON CHALKBOARD] + +PROFESSOR: Good morning. + +I think I'll start even though +people are not quite all here, + +because it's time. + +Sorry, I'd hoped to start +Chapter 10 last time, but + +we'll start it this time. + +When Ashish comes, we'll have +handouts for Chapter 10, the + +new problem set and the +old problem set + +solutions as usual. + +This chapter is about trellis +diagrams for block codes. + +Binary linear block codes of +the kind that we've seen + +before, it's actually a much +more general notion that + +applies to -- + +well, linearity is important, +although we don't see it very + +specifically in the +trellis diagram. + +But we'll see that for +constructing a unique minimal + +trellis, linearity is +an important aspect. + +Or more generally, it's just +the group property of codes + +that allows us to +construct unique + +minimal trellis diagrams. + +And I think it's best +to motivate this + +chapter by an example. + +Here's a nice example of a code +that we know very well. + +It has a nice trellis diagram. + +It's the 8, 4, 4 Reed-Muller +code. + +Just to remind you of how we +construct this code, or one of + +the methods. + +We have many methods. + +We take this kind of universal +eight by eight -- + +well, it's a list +of eight tuples. + +And it's the tensor product +of this little + +matrix three times. + +And if we create this, we get a +matrix that looks like that. + +And we just pick the rows that +have weight four or greater, + +and they are the generators of +the 8, 4, 4 Reed-Muller code. + +So we'll take those as our +set of generators. + +It's the 16 code words generated +by these four + +generators here. + +This goes back to the first part +of the term, but I hope + +you recall that fairly +quickly. + +Now I'd like to draw a trellis +diagram for this code. + +I don't particularly +know why yet. + +One idea I might have in mind +is to do a Viterbi algorithm + +decoding as a maximum likelihood +decoding algorithm + +for this code. + +So let's see if I can +come up with an + +efficient trellis diagram. + +That means one that first +of all has really + +few states in it. + +Relatively few branches would be +efficient as a decoding map + +for the Viterbi algorithm. + +And here's a very nice one. + +This looks sort of +like a rate 1/2 + +four-state trellis diagram. + +Of course, it's not +time-invariant, doesn't go on + +forever like for a convolutional +code, for a + +block code. + +Block code only exists +over a finite time. + +So we're going to get a block +trellis that starts at a + +particular time, that +ends at a particular + +time in a single state. + +But we want the basic +property that the -- + +the paths in this trellis are +in one-to-one correspondence + +with the words in the code. + +So, how many words are +there in the code? + +There are 16 in this code. + +How many paths are there +through this trellis? + +Well, again it has a very +regular structure. + +There is a four-way +branch here. + +Wherever you get to, you have +a two-way branch here. + +You have a two-way +branch here. + +You have no choice here. + +So there are 16 possible ways +to get through this trellis, + +16 trajectories if you like. + +And next let's check if they +correspond to all the possible + +code words. + +Here is the all 0 code +word up here. + +What's next? + +Let's check for the +generators. + +Here is one of the generators, +1, 1, 1, 1, 0, 0, 0, 0. + +And it's a 1, 1, 0, 0. + +This is 1, 1 also. + +1, 1 -- + +no, I'm sorry. + +1, 1, 0, 0, 1, 1, 0, 0. + +That's right. + +That's this one going +through here. + +And 1, 0, 1, 0, 1, 0, 1, 0. + +That's here. + +And what's the last one? + +All ones. + +Well, that's up here too. + +The all one path. + +Yeah. + +AUDIENCE: How did you know +whether to make the + +[INAUDIBLE] procedure? + +PROFESSOR: I had side +information. + +A genie told me. + +I know that this is an +efficient trellis. + +Where we'll get to, and I hope +today in this lecture, is a + +turn-the-crank method of +constructing not only a + +trellis, but the minimal +possible trellis. + +So you'll be able to see how +starting from a set of four + +generators like this, turn the +crank, and I'll produce a + +trellis for you. + +But of course you don't +see that yet. + +I just know that this +is a trellis, + +and it's a nice trellis. + +It has nice, regular +structure. + +You could decode this with a +Viterbi algorithm, and you + +could see the complexity would +be comparable to the + +complexity of decoding +a rate 1/2 four-state + +convolutional code. + +And in fact, you remember I +compared our example rate 1/2 + +four-state convolutional code +which had a coding gain of 4 + +dB with this code saying they +roughly have the same + +complexity. + +And when I said that, this is +what I had in mind, that I + +could decode each of them with +a Viterbi algorithm with + +approximately the same +amount of complexity. + +And unfortunately this only has +a nominal coding gain of 3 + +dB, and an effective +coding gain of + +slightly less than that. + +So it's not quite as good as +the convolutional code. + +And at the end of the day, we're +going to find out that + +that's kind of typical of a +comparison between block and + +convolutional codes of the +same trellis complexity. + +But on the other hand, this is +certainly a better way to + +decode this code, recursive by +the Viterbi algorithm, than to + +do a full maximum likelihood +decoding of all 16 code words, + +which involves just brute force +computing the distance + +to 16 code words. + +This is if you like a more +organized way of performing + +the computation of how far is +the receive sequence from each + +of the 16 code words. + +So the reason we look for +trellises of block codes is + +first of all, it's better +than exhaustive + +maximum likelihood decoding. + +It is a maximum likelihood +decoding algorithm since we're + +going to find that we can +construct a trellis for any + +linear block code, which at +worst, it's never going to be + +more complicated than just +enumerating all the code words + +and doing exhaustive maximum +likelihood decoding. + +And usually, as in this case, +it's going to be a more + +efficient method of doing +maximum likelihood decoding. + +So we will have a general method +of maximum likelihood + +decoding that is more +efficient than + +the exhaustive method. + +Secondly, there's +an interesting + +link to system theory. + +I won't make a great deal +of this in this course. + +But what are we really +doing here? + +We're representing a block code +as a finite state system. + +In fact, a linear block code +is a finite state linear + +system, although again the +linearity is not terribly + +transparent from this picture. + +So we have a linear finite state +system, just as we did + +for the convolutional code. + +However, it's necessarily +time varying. + +It couldn't possibly be shift +invariant because we only have + +a finite time axis, +if you like. + +Time axis only goes over four +time units in this particular + +picture, where I've grouped +two outputs at a time. + +So that's interesting, and for +our purposes an interesting + +aspect of this is that we now +get a notion of how complex is + +a block code. + +So far we've been focused on +parameters like n, k, d, which + +are all algebraic parameters +of the code itself. + +But we really want to know +about performance versus + +complexity. + +So how complex is +the 8 4 4 code? + +Well, now we have a little +bit of a handle on it. + +We can say its complexity is +that of a four-state machine. + +So trellis complexity gives us a +measure of the complexity of + +a block code so that we can, +for instance, say the + +Reed-Muller codes tend to be +less complex than PCH codes. + +And I'll try to give +some substance to + +that as we go along. + +So we get additional parameters +that have more to + +do with what we really care +about, which is decoding + +complexity. + +And finally, I introduce this +subject because it's a + +stepping stone to where we're +really going, is this notion + +of codes on graphs, which is the +underlying concept for the + +capacity-approaching codes +that is our goal point. + +Our whole goal in this course +is to get to capacity, + +specifically on the additive +white Gaussian noise channel. + +And the way that people have +found they get to capacity + +turbo codes, low-density +parity check codes, the + +underlying concept that I'm +going to be framing that in is + +codes on graphs. + +And this is kind of a code on +a very elementary graph. + +So it's a good way from +here to there. + +So that's why we're taking +a little time to + +look at this subject. + +Even though as I say, at the +end of the day, even though + +there's a better way of decoding +block codes than the + +ways we've had previously, and a +better non-algebraic way, it + +still is not going to turn out +to be as good as convolutional + +codes, which we already +know about. + +Any questions on what +we're doing, + +motivation and so forth? + +Yeah. + +AUDIENCE: [INAUDIBLE] +convolutional codes is that + +each node doesn't have two +things coming on to it? + +PROFESSOR: That's right, it's +a little bit more irregular, + +and this trellis section +doesn't look the same. + +We had a completely mixing +trellis section for the + +convolutional code. + +This kind of divides it into two +halves which don't meet. + +This basically expresses the +code as a certain subcode, and + +its coset is down here. + +So, it's not quite the same. + +Looks different. + +Maybe this will turn out +to be interesting. + +Good observation. + +Anything else at this point? + +AUDIENCE: You just said +that this is not a + +convolutional code. + +Or maybe we can have more than +one states, and it is a + +convolutional code. + +PROFESSOR: Let's see, it's +not a convolutional code. + +It's not even a terminated +convolutional code, because it + +doesn't have the simple +shift register + +type of trellis diagram. + +At least it's not the kind +of convolutional + +code we know about. + +But why should it be? + +Let's open up our minds +to more possibilities. + +We don't really care. + +The objective that we have in +mind here is we're just going + +to try to come up with the most +efficient trellis picture + +that we can for block code. + +And we're going to use the +linearity, and we're going to + +basically try to find +as few states as + +possible at each time. + +That's going to be our measure +of efficiency. + +That's not the only one you +could think of, but it'll turn + +out that any notion of efficient +representation comes + +down to the same thing. + +So we'll focus on a minimal +state representation of a + +block code, and you can think +of this as an exercise in + +system theory and minimal + +realizations of a linear system. + +This you can view. + +A set of all 16 code words you +can view is the set of + +possible trajectories of a +linear system on a time axis + +of length 8, and we want to find +a minimal realization, + +minimal state realization +of that linear system. + +So that'll make sense to some +of you, and it won't make an + +awful lot of sense to +the rest of you. + +So we're after a minimal, in the +state sense, minimal state + +complexity, let's say. + +And let's continue to focus on +this example, and let's focus + +on a particular time. + +Let's focus on the halfway +point here. + +Where do the state times +occur, by the way? + +They occur between +the symbol tags. + +You can think of a state as +being associated with a cut + +between a certain set of symbols +which we call the past + +and another set of symbols +which we call the future, + +again using just some theoretic +temporal language. + +So if we make a cut -- + +let's say I do it over here. + +States are based on cuts between +a past and a future, + +so the state actually occurs +between the fourth and the + +fifth symbol here, not at either +of them, if you want to + +draw where is the stated time. + +And let's start with +this example. + +And let's ask if we could find +any simpler trellis for this. + +In other words, let's see if +we can have fewer than four + +states at this midpoint. + +Could we possibly have +fewer than four + +states at the midpoint? + +What's the key property +of states? + +The key property of states is +that once you get to a state, + +that then becomes a summary of +all the history that you know + +about the past, and any past +sequence or partial sequence + +that gets you to this state has +to have the same set of + +possible continuations over here +in the future in order + +for this to be a valid trellis +representation. + +So maybe it will help if I draw +this just focusing on the + +central time. + +There are two ways to get +to this central time. + +One is to get to what +we call the 0 state. + +We can get there by 0, 0, +0, 0 or 1, 1, 1, 1. + +There's a second state which +we can get to again by two + +paths, which are 0, 0, +1, 1 or 1, 1, 0, 0. + +There's a third one, which we +can get to by 1, 0, 1, 0 or + +its complement, 0, 1, 0, 1. + +We'll see that each of these +involves a four-tuple and its + +complement. + +And this is 1, 0, 0, +1 or 0, 1, 1, 0. + +Those are the set of possible +past sequences that can get to + +any of these four states. + +There are two of them. + +Now what this trellis says +is that from this state, + +regardless of how we got here, +either of these two things, + +there are two possible +continuations, which happen to + +be the same thing. + +And the property state has to +be that either of these + +continuations is a legitimate +continuation of either of the + +paths that it takes +to get there. + +So we now have four possible +code words that go through + +this particular state, that +pass through this state. + +And down here, similarly, I +think what we have is the same + +set of code words. + +There's complete symmetry +and so forth. + +Let's ask, could we combine +these two states, somehow + +smush them together into +a single state? + +And the answer is obviously no, +because 0, 0, 1, 1 is not + +a continuation of the +all 0 sequence, or + +of the all 1 sequence. + +And 0, 0, 0, 0 is not a +continuation of the 0, 0, 1, 1 + +sequence or the 1, +1, 0, 0 sequence. + +The property of the state +is the Markov property. + +And there are many ways of +phrasing this, but this is the + +defining property of states, is +that if two past paths have + +a future continuation -- + +I hope you understand this +language as I introduce it -- + +in common, then all +their future + +continuations are in common. + +So I have two past +paths, let's say. + +This is the definition +of states. + +If we can find such a situation, +then we can say + +that these two past paths go +through the same state at the + +cut time, because then we +can smush them together. + +You can think of this as our +starting from, but suppose we + +drew all 16 code words, +and we drew a -- + +here would be a 16 state +trellis, and the first two + +elements of it might be 0, 0, +0, 1, 1, 1, 1, 1, 1, 1, 1. + +And we'd ask, can we smush these +two states together? + +And the answer is yes because +of this property, because 0, + +0, 0 can also be followed +by 1, 1, 1, 1. + +There are actually four +states that we're + +smushing together here. + +1, 1, 1, 1 and 0, 0, 0. + +These are all legitimate code +words, and because they're all + +legitimate, we can basically +break this up into a Cartesian + +product of two paths with two +futures, and represent all + +four of them by a +single state. + +So that's what states do. + +If we want a minimal state +diagram, we should do this as + +much as possible. + +It's not very well-defined right +now, but we should merge + +states wherever this +property holds. + +So this implies they go through +a common state, and + +it's if and only if. + +So you could see it +very concretely + +from the trellis diagram. + +This is the property +that we need. + +You can see that for this +particular code, we do have + +the possibility of combining +all 16 possible states here + +into 4, because we can +combine them all + +pair-wise in this way. + +This is going to come from the +linear property of the code. + +That's why everything +is so symmetric. + +But we can't go any +further than that. + +So we can conclude from this is +that for the 8, 4, 4 code, + +the minimal state space +at the center has four + +states, has size four. + +For simple code like this, you +can simply see what all the + +possibilities are, and this +is the best we can do. + +So do you get that? + +This is fundamental +system theory + +state realization theory. + +I don't know where +in the curriculum + +one gets this nowadays. + +Probably somewhere over towards +the control side, + +maybe in digital signal +processing, but maybe not. + +But we're doing system +theory here. + +We all get that? + +Yeah. + +AUDIENCE: [INAUDIBLE] + +properties basically defined, I +have two possible paths, and + +they have one common +[INAUDIBLE] + +data, they have [INAUDIBLE] + +PROFESSOR: Yeah, if they go +through a common state, that + +implies this statement. + +Conversely, if we have a set of +past paths and future paths + +that have this property, then +we can define a state. + +In other words, states are +always going to look something + +like this, with a set +of past paths. + +We have a set of future paths, +and the state is simply a node + +that they go through such that +you can combine any of these + +paths with any of +these futures. + +If it's symmetric, you could +say the same thing. + +If two futures have a past in +common, then they have all + +their paths in common. + +But whenever you have a state +representation -- + +let's suppose we have +three states there. + +Then this is what, just looking +at those states and + +the initial and final states, +this is what the code is going + +to have to look like. + +Because property of state is +that however you got there, + +you have to be able to take +any of these over here. + +Otherwise the trellis +is invalid. + +If not all of these nine +sequences are code words, then + +it's not a valid trellis +representation, or + +equivalently, it's not a valid +state representation. + +So if, and only if, we +can draw the thing in + +this way, we get it. + +So for a small code, you can +just see how much combining + +you can do. + +In particular, you can ask, +what can the 0, 0 state -- + +0, 0 path sequence -- what can +that be combined with? + +Well, it can only be combined +with sequences that have a 0 + +first part. + +So let me introduce now +the idea of subcodes. + +We have a linear code C. Let's +define an interval on the time + +axis: k, k prime, whatever. + +The subcode C on that interval +is the set of all code words. + +Elegant way to say it is whose +support is in k, k prime. + +In other words, which are all +0 outside, which have all 0 + +symbols outside of this +interval that we've + +identified. + +So that's just notation. + +So specifically, let's say the +past code with respect to a + +certain time, like the +midpoint there. + +Well, we can define that as the +set of all code words that + +are 0 outside the past, the +first four symbols, and we + +define the future subcode as the +set of all code words that + +are 0 outside the future. + +For this code, what is that? + +We list the 16 code words. + +We make this the past. + +We make this the future. + +What is the past subcode here? + +In this particular case, the +past subcode is, of course, + +the all 0 sequence. + +It was always in this code +or this sequence, + +1, 1, 1, 0, 0, 0. + +It's a linear code of dimension +one, and it consists + +of these two code words. + +It is precisely the set of all +code words that can be + +followed by the all +0 sequence. + +So I can read it directly off of +this trellis picture here. + +So everybody with me? + +The past subcode just consists +of those two words. + +The future subcode consists +similarly. + +Looking at the trellis, it's the +1's that are all 0 outside + +the future. + +In other words, can follow +a past which is all 0. + +In other words, it's these +two code words. + +So here are two little +subcodes with a code. + +So by definition, this is +subcode of C. If C is linear, + +you can quickly convince +yourself this is a linear + +subcode, so it's going to have +a certain dimension. + +It's going to have size equal +to a power of two. + +It's even going to have a +minimum distance that is at + +least as great as the minimum +distance of C, because it + +consists of code words of C, so +its minimum non-zero weight + +is going to be at least as great +as that of C. So it has + +some properties immediately. + +These past and future codes seem +to have a lot to do with + +the structure of the +trellis up here. + +In fact, the zero state consists +of precisely -- + +the sequences that go through +the zero state here are not + +coincidentally the set of all +past code words in Cp followed + +by the set of all future +code words in Cf. + +And why is that? + +It's because the set of all +ways of getting to here, + +getting to this state, have +to be the set of all code + +sequences that can be followed +by the all 0 sequence. + +Similarly, the set of all +continuations from this state + +have to be the set of +all continuations + +of the all 0 sequence. + +So the zero state is always +going to be a little + +sub-trellis that is going to +represent in effect -- + +you can draw it as a sum, or +a product, of the past and + +future subcodes. + +In other words, there's a +two-dimensional code that has + +these two generators. + +g1, g2 generates a little +two-dimensional code. + +Here's the fourth code word in +it, the all 1 code sequence. + +And every element in that +two-dimensional code goes + +through the zero state. + +AUDIENCE: [INAUDIBLE] + +code word. + +So then you know -- + +PROFESSOR: It's whatever +it happens to be. + +AUDIENCE: Then you have a +separate state just for -- + +you could combine them. + +PROFESSOR: It doesn't matter. + +Suppose that Cp has +dimension one. + +Cf has dimension one. + +That means Cp is going to +be something like this. + +Cf is going to be something +like this. + +Whatever, what way. + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: It just follows +from linearity. + +And clearly, since C itself was +linear, we're allowed to + +add x, x, x, x all 0's +to y, y, y, y. + +That's a code word, because +these were both code words in + +C. So the linearity allows you +to fill in this fourth corner + +of the rectangle, if you like. + +So Cp plus Cf is always going +to look like this. + +And we'll always call this the +zero state, the state that you + +get to by the all 0 sequence. + +And that can be followed +by the all 0 sequence. + +That's always going to be +called the zero state. + +By linearity, it's always +going to look like that. + +It might not be dimension one. + +It could have any +dimension here. + +So we're really beginning +to get somewhere now. + +What do all these other states +look like, grouped + +theoretically? + +Cosets. + +Somebody -- who said cosets? + +Good, that's right. + +So Cp plus Cf is itself +a subcode of C, a + +two-dimensional subcode. + +So there are four cosets of Cp +plus Cf in C, and we'll see if + +they correspond to +the four states. + +So how do we do this +algebraically? + +Let's draw a generator matrix +for C in a certain form. + +Again, I'll draw the +past, the future. + +So that's the only division I'm +concerned with right now. + +And let me draw it in +general form first. + +I've defined this past subcode, +Cp, at a certain + +dimension, so it has a certain +number of generators. + +So we're going to put up here a +set of generators for Cp, g + +of Cp, however many there +happen to be. + +And what's their common +characteristic? + +They all are all 0 +in the future. + +So they're all going +to look like that. + +Then I'm going to take a set +of generators of Cf, and + +similarly I'm going to use +them up over there. + +These are all code words, and +they're clearly linear and + +independent of those. + +So I'm on my way to constructing +a generator + +matrix for C. + +But obviously I'm going +to need some more. + +We can call this the number of +generators in the past, the + +number of generators +in the future. + +This is the dimension of Cp. + +This is the dimension of Cf. + +And now I need some more +generators, which by + +definition are going to have to +span both past and future. + +Let's see. + +Since I've already introduced +the coset language, let me + +just mysteriously put that +as the generators + +of a quotient group. + +C mod Cp and Cf is what that +means, and it's a quotient + +group, if you know or recall +what a quotient group is. + +But anyway, there are k minus +kp minus kf of these. + +And I don't particularly care +what I put down in here. + +Their property is that +they have to span + +both past and future. + +So for our particular example, +here's the generator for the + +8, 4, 4 code. + +What we're talking about is +a generator that looks + +like 1, 1, 1, 1. + +That's k past is 1. + +0, 0, 0, 1, 1, 1, 1. + +k future is 1. + +They're both one-dimensional +codes. + +Now I need two other generators, +which must span + +past and future. + +So what'll I take? + +Let me just take two more. + +1, 1, 0, 0, 1, 1, 0, 0, 1, +0, 1, 0, 1, 0, 1, 0. + +That would be one +possible choice. + +And so this is k minus kp +minus kf, which is 2. + +What I'm going to claim is that +I'm going to need a state + +for every possible linear +combination of these + +generators. + +So claim -- + +well, let me break it down into +more logical sequence. + +Every code word in C can be +written as some linear + +combination of the generators. + +What does that amount to? + +It amounts to a certain code +word in the past code plus a + +certain component in the future +code, either all 0 or + +they're all one, plus -- + +let me call this the state code, +S, as I do in the notes. + +So in this case we have a +two-dimensional state code. + +Its elements are eight-tuples. + +It's just a subcode of the code +we started with, so it's + +not quite clear how it +corresponds to states yet. + +Well, let me just call that +S for state sequence. + +And I claim I can break this up +because the proof is that + +for every c in C is equal +to a sum of -- + +it's a linear combination +of the generators. + +So I just break that up into +the three possible parts. + +So I get one part that's in the +past subcode, one part's + +in the future subcode, and +one is in the state. + +So this is the past, this is the +future, this is the state. + +So I just break it up +according to this. + +So the 16 code words can all be +written in this way in our + +particular example. + +So let's project this code +word on the past. + +What does projection mean? + +It means you just don't +look at the part + +that's in the future. + +So we're looking at +four-tuples now. + +So C projected on to the +past, this is the part + +that lives over here. + +It is equal to -- well, if I +project the past code word on + +the past, I basically get the +past code word again. + +Let me write it like that, but +it's a little bit redundant. + +Incidental comment: I can regard +this past subcode as + +either an 8 1 4 code, but +what is it really? + +It doesn't live out here. + +It's support is on these four. + +It's really a 4 1 4 repetition +code that lives on the past. + +It's support is the past. + +Similarly, the support here +is the future, and it's + +effectively a 4 1 4 repetition +code for our example. + +But formally, if we project +this on the past, it's a + +one-to-one projection. + +What happens to the +future part? + +This disappears, because the +projection of anything in the + +future code on the past is +all 0 by definition. + +Plus, it's the projection +of the state + +sequence on the past. + +Could the projection of +the state sequence on + +the past be all 0? + +This is actually an +important point. + +Could the the projection of +any linear combination of + +these generators down here +be all 0 in the past? + +The answer is no by +the definition + +of the future subcode. + +If I found a linear combination +of this that was + +all 0 in the past, I should add +that to the generators of + +the future subcode. + +So by defining this in this way, +I've forced this to be + +nonzero, unless, of +course, the state + +sequence itself was 0. + +The all 0 sequence is +in the state code. + +So this is nonzero +if S is nonzero. + +And similarly, if I project +a code word on the + +future, I get -- + +this becomes all 0. + +I get the element of the future +code projected on the + +future, plus the state on the +future, the state projected on + +the future. + +And now I claim further that +this means I can draw a + +trellis as follows. + +Start from here. + +For the all 0 sequence, I'll +have a bunch of parallel paths + +going to the zero state +that together add + +up to the past subcode. + +These are precise. + +One of these is going to be all +0, and these are precisely + +the ones over here that can be +followed by all 0, as I've + +already claimed. + +So these are the ones that +can be followed by 0, and + +similarly over here I'm going to +put all the future subcode. + +I will say these correspond +to the state sequence 0. + +These are the ones where if I +put 0 coefficients down here, + +I just get linear combinations +of the past subcode and the + +future subcode. + +I'm going to write those +as going through + +all one trellis state. + +And I believe I've already made +the argument that this + +state at least is legitimate, +that every combination of + +something in the past subcode +with something in the future + +subcode is a code word. + +This is simply just Cp plus +Cf, what I wrote before. + +So I've got one state that +represents all of Cp plus Cf. + +And now let's take another +typical state down here. + +We'll say this state corresponds +to the state + +sequence S, or S is a general +state sequence. + +Think of it as being nonzero. + +And what am I going +to put on that? + +I'm going to put Cp plus +this state sequence + +projected on the past. + +And that way I'll get all past +projections that are of this + +form for a specific S projected +on the past, + +allowing this to vary through +the past subcode. + +And similarly over here, I will +let the set of all these + +trellis branches be +Cf plus the state + +projected on the future. + +So all the things that go +through this state here will + +be Cp plus Cf plus this +particular state sequence. + +So for each of the state +sequences, I claim I can + +define a state. + +So it's the set of all past +continuations of anything that + +projects on the past as anything +in the past subcode + +plus a past projection of the +state sequence can be combined + +with anything in the future, +Cf plus the future + +continuation of the +state sequence. + +One of these is simply the past +projection of the state + +sequence plus the future +projection + +of the state sequence. + +And this is S, and by +construction this is a code + +word in the code. + +Now by linearity I can add any +past code word to this past + +projection. + +And that's a code word, so any +of these elements plus Sf, + +continued by Sf, the future +projection is a code word. + +See, there we're taking +something generated by Cp and + +the state code. + +And similarly, anything by +here comes out here. + +So I think I've left one or two +details undone, but are + +you convinced that I can define +a state in this way + +such that all of these pasts can +be followed by all these + +futures, and they're +code words? + +In fact, they correspond +to this subset of + +elements of the code. + +We have examples +of it up here. + +For instance, 0, 0, 1, 1. + +Or let's see. + +Let's take a past protection, +1, 1, 0, 0. + +Here's a typical state +sequence, 1, 1, + +0, 0, 1, 1, 0, 0. + +And I can add to this anything +in the past, so I get 0, 0, 1, + +1, 1, 1, 0, 0. + +I can add to it any of these +two, anything in the future. + +So I get 1, 1, 0, 0, 0, 0, 1, 1 +and 0, 0, 1, 1, 0, 0, 1, 1. + +And I claim that all four of +these have the state projected + +on the past equals 1, 1, 0, 0. + +The state projected on the +future is 1, 1, 0, 0. + +And that any of these pasts +can be followed by any of + +these futures. + +So this is C past plus +C future plus 1, 1, + +0, 0, 1, 1, 0, 0. + +That is the claim. + +And furthermore, if I go through +this, dot dot dot, I'm + +going to generate everything in +C. So this is the partition + +of C -- into what? + +S cosets of Cp plus Cf, +subcode of C. So + +algebraically, that's +what's going on. + +But having done this partition, +at least with + +respect to this state space, I +can create something which has + +S states the size of +S, which is -- + +what is this? + +The dimension of S is the +dimension of C minus the + +dimension of Cp minus +the dimension of Cf. + +So I've argued that +I can get a state + +space with this dimension. + +It's a linear state space, and +it has a certain dimension, + +which is just the dimension of +C minus the dimension of the + +past subcode minus +the dimension + +of the future subcode. + +It's the number of generators +that I need for S. So in the + +example, I need two generators +for S, so I get a state space + +of dimension two, +or size four. + +It's just a vector space +over F2 in this case. + +You all with me? + +I think you are. + +I don't see any great puzzles. + +So I can get at least +these few states. + +Could I get any fewer? + +Can I possibly merge any +two of these states? + +Could I draw a trellis in which, +say, I've mushed the + +zero state together with one +of these nonzero states? + +And the answer to that is +clearly no by the definition + +of the past and the +future subcodes. + +These are all of the future +sequences that can follow the + +all 0 past sequence. + +There can't be any more down +here, so we can't possibly + +mush them together. + +And similarly, just by going +through this, if you can't + +take the past part of one state +and combine it with a + +future part of another state +sequence, because that clearly + +is not in the code. + +And I don't have a slick proof +of that in mind at the moment, + +but there is one in the notes. + +The conclusion from this +is what I call + +the state space theorem. + +Given code C, any partition of +the time axis, the total index + +set, into past and future, +I can do this + +not just at the midpoint. + +I can do this any point along +the code that I want to, any + +partition into past +and future. + +The minimal -- + +we get a linear state space, in +other words a vector space, + +S. And the dimension of S is +equal to the dimension of C + +minus the dimension of this +past subcode minus the + +dimension of the +future subcode. + +So we can simply calculate what +the minimal dimension of + +a state space is at any +point along here. + +So for instance, at this point +here, what's the minimal size + +of a state space? + +What's the past subcode here? + +What's the set of all code +sequences that are all 0 in + +the future, as we have +all 0's out here? + +This point, Cp, is just 0, 0. + +It just has dimension 0. + +Yeah, 0 + +What's the future subcode? + +This is the subcode which has +support all out here. + +This is anything that +starts with 0, 0. + +This is 0, 0, 0, 0, 0, +0, 0, 1, 1, 1, 1. + +Let me just write +down generators. + +1, 1, 1, 1, 0, 0. + +So there is -- this is dimension +Cp equals 0. + +Dimension Cf equals 2. + +And so the minimum size of the +state space is 4 minus 2. + +That's again 2. + +AUDIENCE: Does this mean +that [INAUDIBLE] + +each state's the number +of states is the same? + +PROFESSOR: Certainly not +true in general. + +Let me ask about time three. + +Can certainly do that. + +Time three, what's +the past subcode? + +This is the code words that +have support on the first + +three symbols. + +Again, that has to have +dimension 0, because the + +minimum weight of +this code is 4. + +So there can't be anything that +just looks like 1,1,1 and + +then five 0's + +What is the future +subcode for that? + +Now the only generator +of the future subcode + +is 0, 1, 1, 1, 1. + +We have to go this far, and then +it's what futures can we + +get from here? + +There are only two words +that are in the future. + +So in that case we have +dimension past is 0. + +Dimension future is 1. + +So if we drew a state space +here, we would have to have + +eight states. + +In fact, I can do that if I just +draw a little state in + +the middle of each +of these lines. + +I get now a trellis picture +which has an explicit state at + +this third time here, but +it has eight states. + +Oo ugly, so I've masked that. + +I've suppressed that +by this nice + +little four-state trellis. + +But yeah, if you insisted on +drawing a state space at time + +three, it would have +eight states in it. + +We'll get back to that when I +get to this turn-the-crank + +procedure, if I do, of getting +to minimal trellises. + +So what have we done? + +We've established that there is +a uniquely defined minimal + +state space size for +any partition + +between past and future. + +In other words, if there's any +time where you want to make a + +cut in the time axis between +past and future, you can + +define what the minimal +state space size is. + +And now you might ask +the question, can we + +simultaneously achieve minimal +state spaces at all times? + +In other words, can we draw a +single trellis which gets the + +minimal state space +at each time? + +We haven't proved +that there is. + +It might be that if you push +in the state space at one + +time, it forces the state +space to balloon out at + +another time. + +And in fact, for nonlinear +codes, that is + +typically what happens. + +But for linear codes, a +minor miracle occurs. + +And the answer is yes. + +So how am I going +to prove that? + +I'm going to prove it via this +very handy tool, which is also + +a construction tool which is +called a trellis-oriented, or + +a little bit more formally, a +minimum span generator matrix. + +The idea here is, given a +generator matrix, reduce to + +trellis-oriented form. + +We're going to prove that this +is unique, or effectively + +unique, and specifies minimal +trellis at all times in a + +certain way. + +Let's start again. + +So loosely, what is a + +trellis-oriented generator matrix? + +Well, if we have a generator, +say 0, 0, 1, 1, 1, 1, 0, 0, + +its span is this interval from +its starting time to its + +ending time. + +It's this. + +We say it starts at time 3, it +ends at time 6, the span is + +the interval 3 to +6 in this case. + +So we think of this as not being +active before time 3. + +At time 3 we get the first +interesting thing happens. + +A 1 comes up, but then goes +through something. + +These don't have +to all be ones. + +It could be 1, 1, 0, 1. + +Then there's a last 1 at some +point, and then it quiets + +down, and it's dead again. + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: Yes. + +Except I'm not sure. + +Would you say the support of +this was 3, 4, and 6, or would + +you say it was the interval +from 3 to 6? + +I don't know. + +What's the definition +of support? + +AUDIENCE: I don't know it. + +PROFESSOR: I'm not +sure I know. + +It's probably been defined +both ways in different + +literatures. + +So I'll call it a span, but it's +roughly the support of + +the interesting part. + +So that's the definition +of span. + +And what a trellis-oriented +general matrix is, a + +minimal-span matrix, meaning all +generators have a short a + +span as possible. + +I'll just say, are as +short as possible. + +This is a lecture. + +I can be loose. + +Now it's not even clear that's +well-defined yet. + +But let me again give you an +example, and show you how to + +find a trellis-oriented +generating + +matrix just by example. + +Let me take our example here, 1, +1, 0, 0, 1, 1, 0, 0, 1, 0, + +1, 0, 1, 0, 1, 0, 1, +1, 1, 1, 1, 1, 1. + +So there is a generator +matrix that's not in + +trellis-oriented form. + +In particular, I can see that by +adding this to this, I can + +make this generator +have shorter span. + +I can replace it by one, which +is four 0's and then four 1's, + +which we've already +found useful in + +constructing a trellis. + +But let me proceed through +it more systematically. + +How can I make -- + +this generator generates +all words in the code. + +So how can I find a set of +linearly independent + +generators that has +shorter span? + +There's the sort of greedy +way of proceeding. + +Let's take the first +two generators. + +Can I combine these to find +anything that has a shorter + +span, that I can replace one +of the generators with? + +Anybody? + +AUDIENCE: No. + +PROFESSOR: No, I can't. + +That's not the answer +I expected to hear. + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: Let's identify what +the spans of these are. + +That has a span of four. + +That has a span of six. + +That has a span of seven. + +This has a span of eight. + +What I'm trying to do +is to reduce that. + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: So if I add the first +two, that seems like a + +good thing to do, because then +I get 0, 0, 1, 1, and I've + +reduced the span of +that generator. + +Any way I can combine these +two to reduce the span? + +Obviously not, because the span +of this is completely + +included in the span of this. + +If I add these two together, +then I'll get something which + +still starts here +and ends here. + +Why was I able to reduce +the span here? + +Because the spans had the same +starting time, so I got a + +cancellation of the first bit. + +I got a 0 up here. + +That's what I wanted. + +So that's the key +to proceeding. + +If I see any place, any two that +have the same starting + +time, then I can add them +together, and the result will + +be something that has a +shorter span than at + +least one of them. + +So let me do that. + +I see two here that have the +same starting time, and so I + +add that to that, and +I get 0 1 0 1. + +So I've got the span +down to here. + +I can do that down here. + +And I get this, which is a very +nice reduction in span. + +Can I go any further? + +I can clearly look for the same +thing in ending times, if + +I could find two ending times +that were the same. + +I could do the same trick, add +those two generators together, + +and the result would be +something that was shorter + +than at least one of the +component generators. + +But here are my starting +times, here, + +here, here, and here. + +They're all different. + +So I have no possibility for +combining two and getting a + +better starting time. + +Similarly, the ending times +are here, here, and here. + +They're all different. + +So I'm done. + +So, that's how you find a + +trellis-oriented generator matrix. + +And there's a closely associated +theorem, which is + +that a generator matrix g is +trellis-oriented if, and only + +if, all starting times differ, +all ending terms differ. + +Yeah? + +AUDIENCE: What's the definition +of all generators + +as short as possible? + +PROFESSOR: I'm now making it. + +This is really just +motivation. + +So this can be my actual +definition of a + +trellis-oriented generator +matrix, which + +I've proved this theorem. + +It's a matrix in which all the +starting times are different, + +and all the ending times +are different. + +And what I've achieved is +that all generators + +are as short as possible. + +How would I go about proving +the theorem? + +Suppose I have a matrix that's +not in this form. + +And I've already proved that I +can shorten the generators. + +So if it's not in this form, +it's not trellis-oriented. + +The generators are not +as short as possible. + +So all I need to do is +prove the other side. + +Suppose it is in this form. + +Then could I possibly find +shorter generators? + +And the proof of that is +basically the following lemma, + +that the subcode C, take +any interval kk prime. + +So given a trellis-oriented +generating matrix, namely one + +that satisfies these conditions, +then the subcode + +consisting of all the code words +who have support on this + +interval is generated by +the gj in G that have + +support in kk prime. + +And that's kind of intuitive +and obvious. + +On the one hand, it's clear that +any linear combination of + +these generators is a code +word in the subcode. + +Obviously they all have support +in this interval. + +I can't generate anything that +has support outside that + +interval by linear +combinations. + +So the only question is, can I +possibly get anything that's + +in the subcode by combining +with a generator that is + +outside this interval? + +And again, it's clear that say I +take kk prime to be here, if + +all the starting times are +different, and all the ending + +times are different, and I start +to add generators that + +are outside here, I can't +possibly get cancellation of + +the starting time, or I can't +possibly get cancellation of + +the ending time. + +So I'm going to wind up with a +code word which has support + +outside the interval. + +So, it really is +a simple lemma. + +AUDIENCE: [INAUDIBLE] + +have the all 0 code word? + +PROFESSOR: Excuse me? + +AUDIENCE: The all 0 word will +be part of the subcode. + +PROFESSOR: The all 0 word is +always part of the subcode. + +AUDIENCE: [INAUDIBLE] + +who has something outside +this interval. + +Then when you add that with the +all 0 one, you would get + +something that does not belong +to the subcode, [INAUDIBLE] + +PROFESSOR: Right, but +I have to ask if + +there's any code word. + +So I have to consider all +the code words, really. + +But I'm saying if I have a code +word C that is sum of the + +generators, and I have a nonzero +coefficient here on + +any generator that has starting +time outside this + +interval or ending time outside +this interval, then I + +can't possibly get +cancellation of + +that nonzero thing. + +And so if it really requires +this to be nonzero, and then + +I'm going to say that +I get a code word + +that's not in this subcode. + +So that's very quick, intuitive + +sketch of that proof. + +Again, for writing it +out, see the notes. + +But this lemma then proves this +theorem, because it now + +says I can't -- + +if all the starting times are +different, and all the ending + +times are different, then I +can't possibly get shorter + +support for any of +the generators. + +And I don't think so in a +totally convincing way, but + +that basically is +the point here. + +Yeah? + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: Well, now +I'm defining this. + +So, meaning that all the +starting times are different, + +and all the ending times +are different. + +From now on that's going to +be my definition of a + +trellis-oriented generator +matrix. + +So, saying that this property +implies this property. + +But now this lemma has an +interesting consequence. + +This implies for any past and +future, Cp is generated by the + +generators in a trellis-oriented +generating + +matrix with support in p. + +And similarly, Cf is generated +by the generators + +with support in f. + +So for any p and f, I get a +picture that looks like this. + +I can draw now this boundary +anywhere I want, and if the + +matrix was trellis-oriented, +then I'm going to get a + +certain subset of generators +that live in the past, and + +they'll be the generators +in fact of Cp. + +The dimension of them will +simply be the number of + +generators that live in +the past for that + +definition of the past. + +There will be some other +set that live + +entirely in the future. + +Those will be the ones that +generate the future. + +And the ones that are neither +wholly in the past or in the + +future will generate +the state code. + +So that says I can read off the +dimensions of the state + +spaces just by looking at this +single trellis-oriented + +generator matrix. + +So now let me very quickly go +through the calculation that I + +went through a little bit +laboriously over here. + +Suppose I make the whole +thing the future. + +In other words, I draw +a cut before time 0. + +Then the state space +has dimension 0. + +All four generators live +on the future. + +If I make the cut here, the +state space has dimension 1, + +because three of the generators +live on the future. + +One is active at time 1. + +So that means I'm going to get a +two-state trellis at time 1. + +If I make the cut here between +past and future, I see two + +generators live on the future +and are inactive, haven't + +started yet. + +But two of the generators +have already started. + +At this time we have three +active generators. + +Only one is still completely +on the future. + +At this time in the middle I +have two generators which -- + +past subcode, future subcode, +and two that aren't. + +So I get this form that we +looked at over there. + +And I get a state space here +generated by these two + +generators of size two. + +So just by looking at this I go +right through the picture, + +and I find the size of the +state space at each time. + +So this is an algebraic way of +finding the minimal state. + +So now I can draw from this a +trellis just by writing down + +these state spaces. + +Let me leave these +trellises here. + +Let me draw now a full +trellis, or an + +eight-section trellis. + +I'm only going to put one +bit on each trellis. + +Here is the starting +state, dimension 0. + +One state. + +From that I can go +out to 0 or 1. + +I won't label the +state spaces. + +Next time, I'm still +just branching. + +Actually, to make it look like +that, I'm going to want to + +come down here, 0, +1, 1, 1, 1, 0. + +I basically just have four +states at time two + +corresponding to whatever +the first two bits are. + +They all go to different states, +because all these have + +possible future continuations. + +Then I have eight +states at this + +time, still just branching. + +Sorry, this is going to take +some time to do correctly. + +Add this time, then +I come in here. + +0, 1. + +Anyway, and it's symmetrical +on the other side. + +So that's what a full trellis +will look like. + +And how did I do this trellis +in principle? + +I wrote down all +16 code words. + +I wrote down what linear +combinations they were up + +here, and I therefore found what +states they went through + +at each time. + +And then I just drew the graph +that goes through that + +describes those trajectories. + +So I wrote down all +the code words. + +I wrote down all these state +codes at all these times. + +I could have written them +down in any order. + +And then I just connected +the dots according + +to which state -- + +I make this calculation as to +which state they go through. + +That's a good place to stop. + +Let me summarize. + +We now have a method, given a +generator matrix for a binary + +linear block code, of reducing +that generator matrix to + +trellis-oriented form. + +Just by inspection of the +trellis-oriented generator + +matrix, we can determine what +the state space dimensions are + +at each instant of time, at +each possible state cut. + +And we can then draw a trellis +which achieves that minimal + +state space dimension, or +minimal state space size, for + +every moment of time +simultaneously. + +And I assert that this trellis +is the minimal trellis in + +every respect, whether you're +trying to minimize state + +complexity, or if you're using +the Viterbi algorithm. + +Really what you want to minimize +is the number of + +branches, but there's a +calculation about branch + +spaces in the notes that shows +that this also achieves the + +minimal branch space size at +every time, regardless of how + +you draw the trellis. + +More elaborate calculations with +a more refined notion of + +Viterbi algorithm complexities +still come up + +with the same result. + +The result is there is +essentially a unique minimal + +trellis, where it's minimal +in every way. + +And this comes from the linear, +or more broadly, the + +group property of the code. + +So for any linear group code, +there's a well-defined, + +essentially unique up to +re-labeling, minimal trellis + +that achieves the minimum of +whatever complexity quantity + +you want to define. + +So in this sense, the trellis +complexity of a group or + +linear code is very +well-defined. + +It's defined by this minimal +trellis, or by its parameters, + +and we can use that as a measure +of the complexity of + +the corresponding group code. + +And from an engineering point +of view, once we've got this + +minimal trellis, we can use the +Viterbi algorithm to do + +maximum likelihood decoding. + +Just in the same way we did for +convolutional codes, sweep + +from the starting node +to the ending node. + +Digest that, and we'll come back +and talk about it again. + +Do a few more details +on Monday, but + +that's the basic idea. \ No newline at end of file diff --git a/Z2ENBilJWN0.txt b/Z2ENBilJWN0.txt new file mode 100644 index 0000000000000000000000000000000000000000..38bbfa1353868ce7cc75e8fd23b68fd083abd323 --- /dev/null +++ b/Z2ENBilJWN0.txt @@ -0,0 +1,10483 @@ +align:start position:0% + +So today we're going to continue our + + align:start position:0% +So today we're going to continue our + + + align:start position:0% +So today we're going to continue our +discussion of networking we're going to + + align:start position:0% +discussion of networking we're going to + + + align:start position:0% +discussion of networking we're going to +if you remember from the last two times + + align:start position:0% +if you remember from the last two times + + + align:start position:0% +if you remember from the last two times +we've talked about these three different + + align:start position:0% +we've talked about these three different + + + align:start position:0% +we've talked about these three different +network two different network two + + align:start position:0% +network two different network two + + + align:start position:0% +network two different network two +different layers of the network stack so + + align:start position:0% +different layers of the network stack so + + + align:start position:0% +different layers of the network stack so +far we talked about the link layer and + + align:start position:0% +far we talked about the link layer and + + + align:start position:0% +far we talked about the link layer and +we talked about the network layer and + + align:start position:0% +we talked about the network layer and + + + align:start position:0% +we talked about the network layer and +today we're going to talk about the end + + align:start position:0% +today we're going to talk about the end + + + align:start position:0% +today we're going to talk about the end +to end layer um and what we so what + + align:start position:0% +to end layer um and what we so what + + + align:start position:0% +to end layer um and what we so what +we've talked about so far has been a + + align:start position:0% +we've talked about so far has been a + + + align:start position:0% +we've talked about so far has been a +network stack that provides this + + align:start position:0% +network stack that provides this + + + align:start position:0% +network stack that provides this +abstraction of being able to send a + + align:start position:0% +abstraction of being able to send a + + + align:start position:0% +abstraction of being able to send a +message from one machine to another + + align:start position:0% +message from one machine to another + + + align:start position:0% +message from one machine to another +machine across a number of links on a + + align:start position:0% +machine across a number of links on a + + + align:start position:0% +machine across a number of links on a +network and this network stack that + + align:start position:0% +network and this network stack that + + + align:start position:0% +network and this network stack that +we've talked about is if you'll remember + + align:start position:0% +we've talked about is if you'll remember + + + align:start position:0% +we've talked about is if you'll remember +a best effort + + align:start position:0% + + + + align:start position:0% + +Network so best effort Network + + align:start position:0% +Network so best effort Network + + + align:start position:0% +Network so best effort Network +as you'll remember is a network that is + + align:start position:0% +as you'll remember is a network that is + + + align:start position:0% +as you'll remember is a network that is +subject to + + align:start position:0% +subject to + + + align:start position:0% +subject to +losses so some messages may not be + + align:start position:0% +losses so some messages may not be + + + align:start position:0% +losses so some messages may not be +properly transmitted from one point to + + align:start position:0% +properly transmitted from one point to + + + align:start position:0% +properly transmitted from one point to +the other point it's subject to the + + align:start position:0% +the other point it's subject to the + + + align:start position:0% +the other point it's subject to the +possibility of reordering of + + align:start position:0% +possibility of reordering of + + + align:start position:0% +possibility of reordering of +messages as messages may take say for + + align:start position:0% +messages as messages may take say for + + + align:start position:0% +messages as messages may take say for +example different routes through the + + align:start position:0% +example different routes through the + + + align:start position:0% +example different routes through the +network and it's subject to + + align:start position:0% + + + + align:start position:0% + +delays and congestion + + align:start position:0% + + + + align:start position:0% + +typically due to queuing within the + + align:start position:0% +typically due to queuing within the + + + align:start position:0% +typically due to queuing within the +network so today what we're going to + + align:start position:0% +network so today what we're going to + + + align:start position:0% +network so today what we're going to +talk about our is the end to- end layer + + align:start position:0% +talk about our is the end to- end layer + + + align:start position:0% +talk about our is the end to- end layer +and the end to end layer is going to be + + align:start position:0% +and the end to end layer is going to be + + + align:start position:0% +and the end to end layer is going to be +the way that we're going to get at + + align:start position:0% +the way that we're going to get at + + + align:start position:0% +the way that we're going to get at +finally addressing some of these best + + align:start position:0% +finally addressing some of these best + + + align:start position:0% +finally addressing some of these best +effort Network properties we've been + + align:start position:0% +effort Network properties we've been + + + align:start position:0% +effort Network properties we've been +kind of skirting around for the last few + + align:start position:0% +kind of skirting around for the last few + + + align:start position:0% +kind of skirting around for the last few +lectures particular today we're going to + + align:start position:0% +lectures particular today we're going to + + + align:start position:0% +lectures particular today we're going to +focus on the issue of loss how do we + + align:start position:0% +focus on the issue of loss how do we + + + align:start position:0% +focus on the issue of loss how do we +mitigate how do we avoid losses within + + align:start position:0% +mitigate how do we avoid losses within + + + align:start position:0% +mitigate how do we avoid losses within +the network and we'll talk a little bit + + align:start position:0% +the network and we'll talk a little bit + + + align:start position:0% +the network and we'll talk a little bit +about this problem of reordering uh + + align:start position:0% +about this problem of reordering uh + + + align:start position:0% +about this problem of reordering uh +we're going to save the discussion of + + align:start position:0% +we're going to save the discussion of + + + align:start position:0% +we're going to save the discussion of +delays in congestion for next + + align:start position:0% + + + + align:start position:0% + +time + + align:start position:0% +time + + + align:start position:0% +time +so the endand layer in addition to + + align:start position:0% +so the endand layer in addition to + + + align:start position:0% +so the endand layer in addition to +helping us deal with these limitations + + align:start position:0% +helping us deal with these limitations + + + align:start position:0% +helping us deal with these limitations +of a best effort Network provides a few + + align:start position:0% +of a best effort Network provides a few + + + align:start position:0% +of a best effort Network provides a few +other features that we need to mention + + align:start position:0% + + + + align:start position:0% + +so the first thing that the end to-end + + align:start position:0% +so the first thing that the end to-end + + + align:start position:0% +so the first thing that the end to-end +layer does is it provides the ability to + + align:start position:0% +layer does is it provides the ability to + + + align:start position:0% +layer does is it provides the ability to +Multiplex multi applications on top of + + align:start position:0% +Multiplex multi applications on top of + + + align:start position:0% +Multiplex multi applications on top of +the network so the network that we've + + align:start position:0% +the network so the network that we've + + + align:start position:0% +the network so the network that we've +talked about so far is one in which + + align:start position:0% +talked about so far is one in which + + + align:start position:0% +talked about so far is one in which +there are these two end points two + + align:start position:0% +there are these two end points two + + + align:start position:0% +there are these two end points two +computers that are connected to each + + align:start position:0% +computers that are connected to each + + + align:start position:0% +computers that are connected to each +other and they're transmitting a + + align:start position:0% +other and they're transmitting a + + + align:start position:0% +other and they're transmitting a +sequence of messages but we haven't + + align:start position:0% +sequence of messages but we haven't + + + align:start position:0% +sequence of messages but we haven't +really said anything about how those + + align:start position:0% +really said anything about how those + + + align:start position:0% +really said anything about how those +messages get dispatched to different + + align:start position:0% +messages get dispatched to different + + + align:start position:0% +messages get dispatched to different +applications that are running above the + + align:start position:0% +applications that are running above the + + + align:start position:0% +applications that are running above the +network + + align:start position:0% + + + + align:start position:0% + +layer the other thing the end to end + + align:start position:0% +layer the other thing the end to end + + + align:start position:0% +layer the other thing the end to end +layer provides for us is the ability to + + align:start position:0% +layer provides for us is the ability to + + + align:start position:0% +layer provides for us is the ability to +is is + + align:start position:0% +is is + + + align:start position:0% +is is +fragmentation of + + align:start position:0% + + + + align:start position:0% + +messages okay and fragmentation is + + align:start position:0% +messages okay and fragmentation is + + + align:start position:0% +messages okay and fragmentation is +really about is the the fact that these + + align:start position:0% +really about is the the fact that these + + + align:start position:0% +really about is the the fact that these +link layer the link itself may have some + + align:start position:0% +link layer the link itself may have some + + + align:start position:0% +link layer the link itself may have some +maximum size message that it can + + align:start position:0% +maximum size message that it can + + + align:start position:0% +maximum size message that it can +physically transmit because that's the + + align:start position:0% +physically transmit because that's the + + + align:start position:0% +physically transmit because that's the +say for example the maximum size message + + align:start position:0% +say for example the maximum size message + + + align:start position:0% +say for example the maximum size message +is how long the sender and receiver can + + align:start position:0% +is how long the sender and receiver can + + + align:start position:0% +is how long the sender and receiver can +remain synchronized with each other so + + align:start position:0% +remain synchronized with each other so + + + align:start position:0% +remain synchronized with each other so +what the end end layer often does is it + + align:start position:0% +what the end end layer often does is it + + + align:start position:0% +what the end end layer often does is it +provides the ability to take a longer + + align:start position:0% +provides the ability to take a longer + + + align:start position:0% +provides the ability to take a longer +message and fragment it up into smaller + + align:start position:0% +message and fragment it up into smaller + + + align:start position:0% +message and fragment it up into smaller +chunks or fragments that it transmit and + + align:start position:0% +chunks or fragments that it transmit and + + + align:start position:0% +chunks or fragments that it transmit and +it transmits each of those fragments + + align:start position:0% +it transmits each of those fragments + + + align:start position:0% +it transmits each of those fragments +independently as a as a separate message + + align:start position:0% +independently as a as a separate message + + + align:start position:0% +independently as a as a separate message +across the + + align:start position:0% +across the + + + align:start position:0% +across the +network so just to sort of illustrate + + align:start position:0% +network so just to sort of illustrate + + + align:start position:0% +network so just to sort of illustrate +how these things are dealt with within + + align:start position:0% +how these things are dealt with within + + + align:start position:0% +how these things are dealt with within +the end to end layer let's look at a + + align:start position:0% +the end to end layer let's look at a + + + align:start position:0% +the end to end layer let's look at a +little illustration so suppose we have + + align:start position:0% +little illustration so suppose we have + + + align:start position:0% +little illustration so suppose we have +some set of + + align:start position:0% + + + + align:start position:0% + +applications that are connected up to + + align:start position:0% +applications that are connected up to + + + align:start position:0% +applications that are connected up to +the end to end + + align:start position:0% + + + + align:start position:0% + +layer okay so these applications the + + align:start position:0% +layer okay so these applications the + + + align:start position:0% +layer okay so these applications the +idea is going to be that when a message + + align:start position:0% +idea is going to be that when a message + + + align:start position:0% +idea is going to be that when a message +arrives over the end to end layer it's + + align:start position:0% +arrives over the end to end layer it's + + + align:start position:0% +arrives over the end to end layer it's +going to be dispatched to one of these + + align:start position:0% +going to be dispatched to one of these + + + align:start position:0% +going to be dispatched to one of these +applications by looking at a special + + align:start position:0% +applications by looking at a special + + + align:start position:0% +applications by looking at a special +number that's in the header of this + + align:start position:0% +number that's in the header of this + + + align:start position:0% +number that's in the header of this +message that comes in so this number is + + align:start position:0% +message that comes in so this number is + + + align:start position:0% +message that comes in so this number is +often referred to as a port + + align:start position:0% +often referred to as a port + + + align:start position:0% +often referred to as a port +number and each application is going to + + align:start position:0% +number and each application is going to + + + align:start position:0% +number and each application is going to +be running on one of these ports so + + align:start position:0% +be running on one of these ports so + + + align:start position:0% +be running on one of these ports so +often times these ports are sort of + + align:start position:0% +often times these ports are sort of + + + align:start position:0% +often times these ports are sort of +running at well-known addresses so we + + align:start position:0% +running at well-known addresses so we + + + align:start position:0% +running at well-known addresses so we +talk about a little we talk about this + + align:start position:0% +talk about a little we talk about this + + + align:start position:0% +talk about a little we talk about this +numbers very briefly earlier for example + + align:start position:0% +numbers very briefly earlier for example + + + align:start position:0% +numbers very briefly earlier for example +web servers run at Port number 80 on uh + + align:start position:0% +web servers run at Port number 80 on uh + + + align:start position:0% +web servers run at Port number 80 on uh +in the tcpip in the TCP protocol so uh + + align:start position:0% +in the tcpip in the TCP protocol so uh + + + align:start position:0% +in the tcpip in the TCP protocol so uh +web Ser if you want to contact a web + + align:start position:0% +web Ser if you want to contact a web + + + align:start position:0% +web Ser if you want to contact a web +server at a particular machine you talk + + align:start position:0% +server at a particular machine you talk + + + align:start position:0% +server at a particular machine you talk +to Port 80 other times applications will + + align:start position:0% +to Port 80 other times applications will + + + align:start position:0% +to Port 80 other times applications will +send the port number that they're + + align:start position:0% +send the port number that they're + + + align:start position:0% +send the port number that they're +listening at in the message that they in + + align:start position:0% +listening at in the message that they in + + + align:start position:0% +listening at in the message that they in +in a message or two people will exchange + + align:start position:0% +in a message or two people will exchange + + + align:start position:0% +in a message or two people will exchange +the port numbers through some out ofand + + align:start position:0% +the port numbers through some out ofand + + + align:start position:0% +the port numbers through some out ofand +protocol Say by you know telling telling + + align:start position:0% +protocol Say by you know telling telling + + + align:start position:0% +protocol Say by you know telling telling +some telling your friend in an email + + align:start position:0% +some telling your friend in an email + + + align:start position:0% +some telling your friend in an email +that he should connect your server + + align:start position:0% +that he should connect your server + + + align:start position:0% +that he should connect your server +because it's running on Port + + align:start position:0% +because it's running on Port + + + align:start position:0% +because it's running on Port +X so this is the way that so messages + + align:start position:0% +X so this is the way that so messages + + + align:start position:0% +X so this is the way that so messages +now are going to arrive into the end to + + align:start position:0% +now are going to arrive into the end to + + + align:start position:0% +now are going to arrive into the end to +endend layer from the network layer and + + align:start position:0% +endend layer from the network layer and + + + align:start position:0% +endend layer from the network layer and +these messages are going to have in + + align:start position:0% +these messages are going to have in + + + align:start position:0% +these messages are going to have in +their Header information about which + + align:start position:0% +their Header information about which + + + align:start position:0% +their Header information about which +Port they should be dispatched to so the + + align:start position:0% +Port they should be dispatched to so the + + + align:start position:0% +Port they should be dispatched to so the +other functionality the end to end layer + + align:start position:0% +other functionality the end to end layer + + + align:start position:0% +other functionality the end to end layer +I said is this is fragmentation and + + align:start position:0% +I said is this is fragmentation and + + + align:start position:0% +I said is this is fragmentation and +fragmentation is about taking a + + align:start position:0% + + + + align:start position:0% + +message that's being sent down from one + + align:start position:0% +message that's being sent down from one + + + align:start position:0% +message that's being sent down from one +of these applications into the end + + align:start position:0% +of these applications into the end + + + align:start position:0% +of these applications into the end +to-end layer and then that message on + + align:start position:0% +to-end layer and then that message on + + + align:start position:0% +to-end layer and then that message on +its + + align:start position:0% +its + + + align:start position:0% +its +way to the network + + align:start position:0% + + + + align:start position:0% + +layer gets fragmented up into a number + + align:start position:0% +layer gets fragmented up into a number + + + align:start position:0% +layer gets fragmented up into a number +of chunks so these are each each of + + align:start position:0% +of chunks so these are each each of + + + align:start position:0% +of chunks so these are each each of +these little chunks in this message is a + + align:start position:0% +these little chunks in this message is a + + + align:start position:0% +these little chunks in this message is a +it's called a + + align:start position:0% + + + + align:start position:0% + +fragment so these are sort of two uh and + + align:start position:0% +fragment so these are sort of two uh and + + + align:start position:0% +fragment so these are sort of two uh and +the so often times we talk about what + + align:start position:0% +the so often times we talk about what + + + align:start position:0% +the so often times we talk about what +the end one common end to end layer is + + align:start position:0% +the end one common end to end layer is + + + align:start position:0% +the end one common end to end layer is +one that provides an abstraction that's + + align:start position:0% +one that provides an abstraction that's + + + align:start position:0% +one that provides an abstraction that's +called a stream so a + + align:start position:0% + + + + align:start position:0% + +stream is simply a uh flow of messages + + align:start position:0% +stream is simply a uh flow of messages + + + align:start position:0% +stream is simply a uh flow of messages +or data from one endpoint to the other + + align:start position:0% +or data from one endpoint to the other + + + align:start position:0% +or data from one endpoint to the other +one application to the the other um and + + align:start position:0% +one application to the the other um and + + + align:start position:0% +one application to the the other um and +where the where the the segments in that + + align:start position:0% +where the where the the segments in that + + + align:start position:0% +where the where the the segments in that +stream are guaranteed to be delivered uh + + align:start position:0% +stream are guaranteed to be delivered uh + + + align:start position:0% +stream are guaranteed to be delivered uh +Lo are are loss free so there are no + + align:start position:0% +Lo are are loss free so there are no + + + align:start position:0% +Lo are are loss free so there are no +missing segments or missing messages uh + + align:start position:0% +missing segments or missing messages uh + + + align:start position:0% +missing segments or missing messages uh +and they're in order so the + + align:start position:0% +and they're in order so the + + + align:start position:0% +and they're in order so the +application knows that the data that it + + align:start position:0% +application knows that the data that it + + + align:start position:0% +application knows that the data that it +receives is going to be in the order + + align:start position:0% +receives is going to be in the order + + + align:start position:0% +receives is going to be in the order +that the the receiver knows the + + align:start position:0% +that the the receiver knows the + + + align:start position:0% +that the the receiver knows the +application it rece the data it receives + + align:start position:0% +application it rece the data it receives + + + align:start position:0% +application it rece the data it receives +is going to be in the order that the + + align:start position:0% +is going to be in the order that the + + + align:start position:0% +is going to be in the order that the +sender sent it out on the channel and + + align:start position:0% +sender sent it out on the channel and + + + align:start position:0% +sender sent it out on the channel and +there won't be any missing messages so + + align:start position:0% +there won't be any missing messages so + + + align:start position:0% +there won't be any missing messages so +this sounds like a pretty convenient + + align:start position:0% +this sounds like a pretty convenient + + + align:start position:0% +this sounds like a pretty convenient +abstraction and it's one that is often + + align:start position:0% +abstraction and it's one that is often + + + align:start position:0% +abstraction and it's one that is often +used in applications and in fact the + + align:start position:0% +used in applications and in fact the + + + align:start position:0% +used in applications and in fact the +stream the stream abstraction is the + + align:start position:0% +stream the stream abstraction is the + + + align:start position:0% +stream the stream abstraction is the +abstraction that the TCP protocol + + align:start position:0% +abstraction that the TCP protocol + + + align:start position:0% +abstraction that the TCP protocol +provides + + align:start position:0% +provides + + + align:start position:0% +provides +okay so um just to sort of make it + + align:start position:0% +okay so um just to sort of make it + + + align:start position:0% +okay so um just to sort of make it +clear I just want to look quickly the at + + align:start position:0% +clear I just want to look quickly the at + + + align:start position:0% +clear I just want to look quickly the at +a simplified endtoend header format so + + align:start position:0% +a simplified endtoend header format so + + + align:start position:0% +a simplified endtoend header format so +we looked at the header formats for uh + + align:start position:0% +we looked at the header formats for uh + + + align:start position:0% +we looked at the header formats for uh +other at the other layers last time and + + align:start position:0% +other at the other layers last time and + + + align:start position:0% +other at the other layers last time and +this is just showing some of the things + + align:start position:0% +this is just showing some of the things + + + align:start position:0% +this is just showing some of the things +that you might expect to see in an end + + align:start position:0% +that you might expect to see in an end + + + align:start position:0% +that you might expect to see in an end +to- end header there of course could be + + align:start position:0% +to- end header there of course could be + + + align:start position:0% +to- end header there of course could be +there are additional things if you go + + align:start position:0% +there are additional things if you go + + + align:start position:0% +there are additional things if you go +look at the TCP header but these are the + + align:start position:0% +look at the TCP header but these are the + + + align:start position:0% +look at the TCP header but these are the +ones that mostly matter from the point + + align:start position:0% +ones that mostly matter from the point + + + align:start position:0% +ones that mostly matter from the point +of view of this class so there's a + + align:start position:0% +of view of this class so there's a + + + align:start position:0% +of view of this class so there's a +source Port which allows the which + + align:start position:0% +source Port which allows the which + + + align:start position:0% +source Port which allows the which +specifies which Port the sender of the + + align:start position:0% +specifies which Port the sender of the + + + align:start position:0% +specifies which Port the sender of the +message is listening at on the other + + align:start position:0% +message is listening at on the other + + + align:start position:0% +message is listening at on the other +side there's a destination Port which + + align:start position:0% +side there's a destination Port which + + + align:start position:0% +side there's a destination Port which +specifies which port number uh this + + align:start position:0% +specifies which port number uh this + + + align:start position:0% +specifies which port number uh this +message should be sent to on the + + align:start position:0% +message should be sent to on the + + + align:start position:0% +message should be sent to on the +receiver side um there's something + + align:start position:0% +receiver side um there's something + + + align:start position:0% +receiver side um there's something +called the nons the non is just a unique + + align:start position:0% +called the nons the non is just a unique + + + align:start position:0% +called the nons the non is just a unique +identifier it's just a thing that + + align:start position:0% +identifier it's just a thing that + + + align:start position:0% +identifier it's just a thing that +uniquely identifies this message as far + + align:start position:0% +uniquely identifies this message as far + + + align:start position:0% +uniquely identifies this message as far +as the two as as far as the conversation + + align:start position:0% +as the two as as far as the conversation + + + align:start position:0% +as the two as as far as the conversation +between the two endpoints is concerned + + align:start position:0% +between the two endpoints is concerned + + + align:start position:0% +between the two endpoints is concerned +for the purposes a common kind of anoun + + align:start position:0% +for the purposes a common kind of anoun + + + align:start position:0% +for the purposes a common kind of anoun +to use is just a sequence number that + + align:start position:0% +to use is just a sequence number that + + + align:start position:0% +to use is just a sequence number that +gets incremented by one every time an + + align:start position:0% +gets incremented by one every time an + + + align:start position:0% +gets incremented by one every time an +additional message is sent and then + + align:start position:0% +additional message is sent and then + + + align:start position:0% +additional message is sent and then +oftentimes in the end to end layer + + align:start position:0% +oftentimes in the end to end layer + + + align:start position:0% +oftentimes in the end to end layer +there's also some check check sum + + align:start position:0% +there's also some check check sum + + + align:start position:0% +there's also some check check sum +information something that allows you to + + align:start position:0% +information something that allows you to + + + align:start position:0% +information something that allows you to +verify the Integrity of the messages + + align:start position:0% +verify the Integrity of the messages + + + align:start position:0% +verify the Integrity of the messages +that are transmitted out over the + + align:start position:0% +that are transmitted out over the + + + align:start position:0% +that are transmitted out over the +network and we do this at the end to end + + align:start position:0% +network and we do this at the end to end + + + align:start position:0% +network and we do this at the end to end +layer we we we saw that the check sums + + align:start position:0% +layer we we we saw that the check sums + + + align:start position:0% +layer we we we saw that the check sums +sometimes appeared in the link layer + + align:start position:0% +sometimes appeared in the link layer + + + align:start position:0% +sometimes appeared in the link layer +before they also appear at the end to + + align:start position:0% +before they also appear at the end to + + + align:start position:0% +before they also appear at the end to +end layer because it's uh important it's + + align:start position:0% +end layer because it's uh important it's + + + align:start position:0% +end layer because it's uh important it's +it's possible that as you guys read in + + align:start position:0% +it's possible that as you guys read in + + + align:start position:0% +it's possible that as you guys read in +the in the paper about end to end + + align:start position:0% +the in the paper about end to end + + + align:start position:0% +the in the paper about end to end +arguments the end to end argument often + + align:start position:0% +arguments the end to end argument often + + + align:start position:0% +arguments the end to end argument often +times we want to verify that a message + + align:start position:0% +times we want to verify that a message + + + align:start position:0% +times we want to verify that a message +is correct uh at the at the end to end + + align:start position:0% +is correct uh at the at the end to end + + + align:start position:0% +is correct uh at the at the end to end +layer or at the application layer even + + align:start position:0% +layer or at the application layer even + + + align:start position:0% +layer or at the application layer even +if we have already maybe verified that + + align:start position:0% +if we have already maybe verified that + + + align:start position:0% +if we have already maybe verified that +that was the case at the link layer + + align:start position:0% +that was the case at the link layer + + + align:start position:0% +that was the case at the link layer +because the message could have been + + align:start position:0% +because the message could have been + + + align:start position:0% +because the message could have been +corrupted somewhere above just the link + + align:start position:0% +corrupted somewhere above just the link + + + align:start position:0% +corrupted somewhere above just the link +layer right so um this is sort of the + + align:start position:0% +layer right so um this is sort of the + + + align:start position:0% +layer right so um this is sort of the +abstraction that the end to end layer + + align:start position:0% +abstraction that the end to end layer + + + align:start position:0% +abstraction that the end to end layer +provides notice that the the header + + align:start position:0% +provides notice that the the header + + + align:start position:0% +provides notice that the the header +format here doesn't actually include not + + align:start position:0% +format here doesn't actually include not + + + align:start position:0% +format here doesn't actually include not +it doesn't include for example the + + align:start position:0% +it doesn't include for example the + + + align:start position:0% +it doesn't include for example the +addresses of the endpoints the IP + + align:start position:0% +addresses of the endpoints the IP + + + align:start position:0% +addresses of the endpoints the IP +addresses that's because the IP address + + align:start position:0% +addresses that's because the IP address + + + align:start position:0% +addresses that's because the IP address +are in the IP header so remember this is + + align:start position:0% +are in the IP header so remember this is + + + align:start position:0% +are in the IP header so remember this is +just the additional information that's + + align:start position:0% +just the additional information that's + + + align:start position:0% +just the additional information that's +added by the end to end layer and is + + align:start position:0% +added by the end to end layer and is + + + align:start position:0% +added by the end to end layer and is +used to dispatch from the end to end + + align:start position:0% +used to dispatch from the end to end + + + align:start position:0% +used to dispatch from the end to end +layer to the applications that are + + align:start position:0% +layer to the applications that are + + + align:start position:0% +layer to the applications that are +running above it the once the we're + + align:start position:0% +running above it the once the we're + + + align:start position:0% +running above it the once the we're +we're dealing with the endtoend header + + align:start position:0% +we're dealing with the endtoend header + + + align:start position:0% +we're dealing with the endtoend header +all the network the packets have already + + align:start position:0% +all the network the packets have already + + + align:start position:0% +all the network the packets have already +been transmitted across the network and + + align:start position:0% +been transmitted across the network and + + + align:start position:0% +been transmitted across the network and +in fact we don't necessarily we don't + + align:start position:0% +in fact we don't necessarily we don't + + + align:start position:0% +in fact we don't necessarily we don't +need to know what the IP address is + + align:start position:0% +need to know what the IP address is + + + align:start position:0% +need to know what the IP address is +anymore because this is happening on the + + align:start position:0% +anymore because this is happening on the + + + align:start position:0% +anymore because this is happening on the +local machine and the IP all the + + align:start position:0% +local machine and the IP all the + + + align:start position:0% +local machine and the IP all the +applications are running at the same IP + + align:start position:0% +applications are running at the same IP + + + align:start position:0% +applications are running at the same IP +address okay so um but the other things + + align:start position:0% +address okay so um but the other things + + + align:start position:0% +address okay so um but the other things +that we said the end so I said today + + align:start position:0% +that we said the end so I said today + + + align:start position:0% +that we said the end so I said today +we're going to focus mostly on the + + align:start position:0% +we're going to focus mostly on the + + + align:start position:0% +we're going to focus mostly on the +ability of the end to-end layer to + + align:start position:0% +ability of the end to-end layer to + + + align:start position:0% +ability of the end to-end layer to +mitigate these problems of losses so + + align:start position:0% +mitigate these problems of losses so + + + align:start position:0% +mitigate these problems of losses so +this is sort of the abstraction that the + + align:start position:0% +this is sort of the abstraction that the + + + align:start position:0% +this is sort of the abstraction that the +end to- end layer provides but what we + + align:start position:0% +end to- end layer provides but what we + + + align:start position:0% +end to- end layer provides but what we +want to look at now is how does the end + + align:start position:0% +want to look at now is how does the end + + + align:start position:0% +want to look at now is how does the end +to-end layer actually deal with loss and + + align:start position:0% +to-end layer actually deal with loss and + + + align:start position:0% +to-end layer actually deal with loss and +we're going to talk about two different + + align:start position:0% +we're going to talk about two different + + + align:start position:0% +we're going to talk about two different +uh techniques or there's two different + + align:start position:0% +uh techniques or there's two different + + + align:start position:0% +uh techniques or there's two different +components to uh dealing with loss so + + align:start position:0% +components to uh dealing with loss so + + + align:start position:0% +components to uh dealing with loss so +the first thing we want to do is we want + + align:start position:0% +the first thing we want to do is we want + + + align:start position:0% +the first thing we want to do is we want +to make sure that no packets get lost + + align:start position:0% +to make sure that no packets get lost + + + align:start position:0% +to make sure that no packets get lost +during transmission and the way we're + + align:start position:0% +during transmission and the way we're + + + align:start position:0% +during transmission and the way we're +going to do that is providing we call + + align:start position:0% +going to do that is providing we call + + + align:start position:0% +going to do that is providing we call +at least + + align:start position:0% + + + + align:start position:0% + +once + + align:start position:0% + + + + align:start position:0% + +delivery the reason I put at least once + + align:start position:0% +delivery the reason I put at least once + + + align:start position:0% +delivery the reason I put at least once +in quotes here is that I'm going to talk + + align:start position:0% +in quotes here is that I'm going to talk + + + align:start position:0% +in quotes here is that I'm going to talk +you through a protocol but and this + + align:start position:0% +you through a protocol but and this + + + align:start position:0% +you through a protocol but and this +protocol is going to guarantee that a + + align:start position:0% +protocol is going to guarantee that a + + + align:start position:0% +protocol is going to guarantee that a +message gets received by the receiver as + + align:start position:0% +message gets received by the receiver as + + + align:start position:0% +message gets received by the receiver as +long as for example the receiver doesn't + + align:start position:0% +long as for example the receiver doesn't + + + align:start position:0% +long as for example the receiver doesn't +completely fail or the network doesn't + + align:start position:0% +completely fail or the network doesn't + + + align:start position:0% +completely fail or the network doesn't +completely explode so it's always + + align:start position:0% +completely explode so it's always + + + align:start position:0% +completely explode so it's always +possible that messages can be lost + + align:start position:0% +possible that messages can be lost + + + align:start position:0% +possible that messages can be lost +because there can be some physical + + align:start position:0% +because there can be some physical + + + align:start position:0% +because there can be some physical +failure that makes it impossible for the + + align:start position:0% +failure that makes it impossible for the + + + align:start position:0% +failure that makes it impossible for the +messages to get through but as long as + + align:start position:0% +messages to get through but as long as + + + align:start position:0% +messages to get through but as long as +it is possible for the message to get + + align:start position:0% +it is possible for the message to get + + + align:start position:0% +it is possible for the message to get +through uh there there there's a a very + + align:start position:0% +through uh there there there's a a very + + + align:start position:0% +through uh there there there's a a very +high probability the message will in + + align:start position:0% +high probability the message will in + + + align:start position:0% +high probability the message will in +fact get through and if the message + + align:start position:0% +fact get through and if the message + + + align:start position:0% +fact get through and if the message +doesn't get through what this is this at + + align:start position:0% +doesn't get through what this is this at + + + align:start position:0% +doesn't get through what this is this at +least once delivery protocol is going to + + align:start position:0% +least once delivery protocol is going to + + + align:start position:0% +least once delivery protocol is going to +guarantee is that the receiver knows + + align:start position:0% +guarantee is that the receiver knows + + + align:start position:0% +guarantee is that the receiver knows +that the sender may not have actually + + align:start position:0% +that the sender may not have actually + + + align:start position:0% +that the sender may not have actually +received the message okay so um now once + + align:start position:0% +received the message okay so um now once + + + align:start position:0% +received the message okay so um now once +we talk about at least once we're going + + align:start position:0% +we talk about at least once we're going + + + align:start position:0% +we talk about at least once we're going +to talk about something we call at most + + align:start position:0% +to talk about something we call at most + + + align:start position:0% +to talk about something we call at most +once + + align:start position:0% +once + + + align:start position:0% +once +delivery um and the issue with it most + + align:start position:0% +delivery um and the issue with it most + + + align:start position:0% +delivery um and the issue with it most +once delivery is that the at least once + + align:start position:0% +once delivery is that the at least once + + + align:start position:0% +once delivery is that the at least once +protocol that I'm going to sketch out is + + align:start position:0% +protocol that I'm going to sketch out is + + + align:start position:0% +protocol that I'm going to sketch out is +going to generate duplicates and we're + + align:start position:0% +going to generate duplicates and we're + + + align:start position:0% +going to generate duplicates and we're +going to need to make sure that we can + + align:start position:0% +going to need to make sure that we can + + + align:start position:0% +going to need to make sure that we can +get rid of some of the + + align:start position:0% +get rid of some of the + + + align:start position:0% +get rid of some of the +duplicates um and these two things + + align:start position:0% +duplicates um and these two things + + + align:start position:0% +duplicates um and these two things +together are going to provide what's + + align:start position:0% +together are going to provide what's + + + align:start position:0% +together are going to provide what's +known as exactly once delivery of + + align:start position:0% + + + + align:start position:0% + +messages + + align:start position:0% +messages + + + align:start position:0% +messages +okay so let's start off by talking about + + align:start position:0% +okay so let's start off by talking about + + + align:start position:0% +okay so let's start off by talking about +our at least once + + align:start position:0% + + + + align:start position:0% + +protocol this protocol is going to + + align:start position:0% +protocol this protocol is going to + + + align:start position:0% +protocol this protocol is going to +guarantee that uh if at all possible the + + align:start position:0% +guarantee that uh if at all possible the + + + align:start position:0% +guarantee that uh if at all possible the +message will be received a message will + + align:start position:0% +message will be received a message will + + + align:start position:0% +message will be received a message will +be received by the receiver and the way + + align:start position:0% +be received by the receiver and the way + + + align:start position:0% +be received by the receiver and the way +that we're going to do this is really + + align:start position:0% +that we're going to do this is really + + + align:start position:0% +that we're going to do this is really +very straightforward we're just going to + + align:start position:0% +very straightforward we're just going to + + + align:start position:0% +very straightforward we're just going to +have the receiver send a message back to + + align:start position:0% +have the receiver send a message back to + + + align:start position:0% +have the receiver send a message back to +the sender that says I got the message + + align:start position:0% +the sender that says I got the message + + + align:start position:0% +the sender that says I got the message +so the receiver when it gets the message + + align:start position:0% +so the receiver when it gets the message + + + align:start position:0% +so the receiver when it gets the message +sends this what's called an + + align:start position:0% +sends this what's called an + + + align:start position:0% +sends this what's called an +acknowledgement + + align:start position:0% + + + + align:start position:0% + +back sometimes abbreviated + + align:start position:0% +back sometimes abbreviated + + + align:start position:0% +back sometimes abbreviated +act + + align:start position:0% +act + + + align:start position:0% +act +uh indicating that the message was + + align:start position:0% +uh indicating that the message was + + + align:start position:0% +uh indicating that the message was +received at the other end okay this is + + align:start position:0% +received at the other end okay this is + + + align:start position:0% +received at the other end okay this is +just going to be uh this just going to + + align:start position:0% +just going to be uh this just going to + + + align:start position:0% +just going to be uh this just going to +be sent back to the receiver directly so + + align:start position:0% +be sent back to the receiver directly so + + + align:start position:0% +be sent back to the receiver directly so +um in order to send this acknowledgement + + align:start position:0% +um in order to send this acknowledgement + + + align:start position:0% +um in order to send this acknowledgement +though we're going to need a way for the + + align:start position:0% +though we're going to need a way for the + + + align:start position:0% +though we're going to need a way for the +receiver to refer to the message that + + align:start position:0% +receiver to refer to the message that + + + align:start position:0% +receiver to refer to the message that +the sender sent right so we want the + + align:start position:0% +the sender sent right so we want the + + + align:start position:0% +the sender sent right so we want the +receiver to be able to say I received + + align:start position:0% +receiver to be able to say I received + + + align:start position:0% +receiver to be able to say I received +this message that you that you sent to + + align:start position:0% +this message that you that you sent to + + + align:start position:0% +this message that you that you sent to +me and one way that you so and the + + align:start position:0% +me and one way that you so and the + + + align:start position:0% +me and one way that you so and the +simplest way to be able to do that is to + + align:start position:0% +simplest way to be able to do that is to + + + align:start position:0% +simplest way to be able to do that is to +just use this nons information that's in + + align:start position:0% +just use this nons information that's in + + + align:start position:0% +just use this nons information that's in +the packets we said the nons is a unique + + align:start position:0% +the packets we said the nons is a unique + + + align:start position:0% +the packets we said the nons is a unique +identifier as far as the two end points + + align:start position:0% +identifier as far as the two end points + + + align:start position:0% +identifier as far as the two end points +of the conversation are Ur are are + + align:start position:0% +of the conversation are Ur are are + + + align:start position:0% +of the conversation are Ur are are +concerned so the the acknowledgement is + + align:start position:0% +concerned so the the acknowledgement is + + + align:start position:0% +concerned so the the acknowledgement is +basically just going to be the knots of + + align:start position:0% +basically just going to be the knots of + + + align:start position:0% +basically just going to be the knots of +the message + + align:start position:0% + + + + align:start position:0% + +okay so let's look at how this works in + + align:start position:0% +okay so let's look at how this works in + + + align:start position:0% +okay so let's look at how this works in +a simple + + align:start position:0% +a simple + + + align:start position:0% +a simple +example so the idea is that the sender + + align:start position:0% +example so the idea is that the sender + + + align:start position:0% +example so the idea is that the sender +at some + + align:start position:0% +at some + + + align:start position:0% +at some +point is going to send a message to the + + align:start position:0% +point is going to send a message to the + + + align:start position:0% +point is going to send a message to the +receiver and this message is going to + + align:start position:0% +receiver and this message is going to + + + align:start position:0% +receiver and this message is going to +contain information like uh well it's + + align:start position:0% +contain information like uh well it's + + + align:start position:0% +contain information like uh well it's +going to have the uh address of the + + align:start position:0% +going to have the uh address of the + + + align:start position:0% +going to have the uh address of the +sender the address of the receiver the + + align:start position:0% +sender the address of the receiver the + + + align:start position:0% +sender the address of the receiver the +ports on both ends the message is + + align:start position:0% +ports on both ends the message is + + + align:start position:0% +ports on both ends the message is +supposed to be sent to this knots + + align:start position:0% +supposed to be sent to this knots + + + align:start position:0% +supposed to be sent to this knots +information that uniquely identifies the + + align:start position:0% +information that uniquely identifies the + + + align:start position:0% +information that uniquely identifies the +message and then whatever the data that + + align:start position:0% +message and then whatever the data that + + + align:start position:0% +message and then whatever the data that +needs to go in the message now uh when + + align:start position:0% +needs to go in the message now uh when + + + align:start position:0% +needs to go in the message now uh when +it sends this message what's going to + + align:start position:0% +it sends this message what's going to + + + align:start position:0% +it sends this message what's going to +happen is that the the sender is going + + align:start position:0% +happen is that the the sender is going + + + align:start position:0% +happen is that the the sender is going +to keep this table of pending messages + + align:start position:0% +to keep this table of pending messages + + + align:start position:0% +to keep this table of pending messages +so the sender is going to keep a list of + + align:start position:0% +so the sender is going to keep a list of + + + align:start position:0% +so the sender is going to keep a list of +all the messages that it hasn't yet + + align:start position:0% +all the messages that it hasn't yet + + + align:start position:0% +all the messages that it hasn't yet +heard + + align:start position:0% + + + + align:start position:0% + +acknowledged and then at some point and + + align:start position:0% +acknowledged and then at some point and + + + align:start position:0% +acknowledged and then at some point and +it's going to keep for example if this + + align:start position:0% +it's going to keep for example if this + + + align:start position:0% +it's going to keep for example if this +message is message say that the the name + + align:start position:0% +message is message say that the the name + + + align:start position:0% +message is message say that the the name +of this message is what + + align:start position:0% +of this message is what + + + align:start position:0% +of this message is what +and the knots for this message is X is + + align:start position:0% +and the knots for this message is X is + + + align:start position:0% +and the knots for this message is X is +going to add that information into its + + align:start position:0% +going to add that information into its + + + align:start position:0% +going to add that information into its +table now at some point later the + + align:start position:0% +table now at some point later the + + + align:start position:0% +table now at some point later the +receiver is going to send an + + align:start position:0% +receiver is going to send an + + + align:start position:0% +receiver is going to send an +acknowledgement for this message one + + align:start position:0% +acknowledgement for this message one + + + align:start position:0% +acknowledgement for this message one +back uh and it's just going to have this + + align:start position:0% +back uh and it's just going to have this + + + align:start position:0% +back uh and it's just going to have this +the sender and the receiver IP address + + align:start position:0% +the sender and the receiver IP address + + + align:start position:0% +the sender and the receiver IP address +the port number that of uh of the + + align:start position:0% +the port number that of uh of the + + + align:start position:0% +the port number that of uh of the +receiver and the knots um which the + + align:start position:0% +receiver and the knots um which the + + + align:start position:0% +receiver and the knots um which the +sender is going to use in order to + + align:start position:0% +sender is going to use in order to + + + align:start position:0% +sender is going to use in order to +remove this entry from its table so once + + align:start position:0% +remove this entry from its table so once + + + align:start position:0% +remove this entry from its table so once +the sender receives an acknowledgement + + align:start position:0% +the sender receives an acknowledgement + + + align:start position:0% +the sender receives an acknowledgement +for a message it no longer needs to keep + + align:start position:0% +for a message it no longer needs to keep + + + align:start position:0% +for a message it no longer needs to keep +any state about it because it knows that + + align:start position:0% +any state about it because it knows that + + + align:start position:0% +any state about it because it knows that +the receiver has received it okay okay + + align:start position:0% +the receiver has received it okay okay + + + align:start position:0% +the receiver has received it okay okay +so how does this do us any good how is + + align:start position:0% +so how does this do us any good how is + + + align:start position:0% +so how does this do us any good how is +this at least once well let's see what + + align:start position:0% +this at least once well let's see what + + + align:start position:0% +this at least once well let's see what +happens when there's loss that occurs + + align:start position:0% +happens when there's loss that occurs + + + align:start position:0% +happens when there's loss that occurs +within the network so the idea is is + + align:start position:0% +within the network so the idea is is + + + align:start position:0% +within the network so the idea is is +very simple suppose we suppose that the + + align:start position:0% +very simple suppose we suppose that the + + + align:start position:0% +very simple suppose we suppose that the +sender sends out a message message two + + align:start position:0% +sender sends out a message message two + + + align:start position:0% +sender sends out a message message two +this this time and that message somehow + + align:start position:0% +this this time and that message somehow + + + align:start position:0% +this this time and that message somehow +gets lost in in transit through the + + align:start position:0% +gets lost in in transit through the + + + align:start position:0% +gets lost in in transit through the +network so the network uh drops the + + align:start position:0% +network so the network uh drops the + + + align:start position:0% +network so the network uh drops the +message either because of congestion or + + align:start position:0% +message either because of congestion or + + + align:start position:0% +message either because of congestion or +because some link failed and it doesn't + + align:start position:0% +because some link failed and it doesn't + + + align:start position:0% +because some link failed and it doesn't +get through the idea is that the sender + + align:start position:0% +get through the idea is that the sender + + + align:start position:0% +get through the idea is that the sender +is going to keep a timer associated with + + align:start position:0% +is going to keep a timer associated with + + + align:start position:0% +is going to keep a timer associated with +every message that it sends + + align:start position:0% +every message that it sends + + + align:start position:0% +every message that it sends +and this timer is going to be a timeout + + align:start position:0% +and this timer is going to be a timeout + + + align:start position:0% +and this timer is going to be a timeout +value that's going to tell the sender + + align:start position:0% +value that's going to tell the sender + + + align:start position:0% +value that's going to tell the sender +when it should retry transmitting this + + align:start position:0% +when it should retry transmitting this + + + align:start position:0% +when it should retry transmitting this +message and the sender is just going to + + align:start position:0% +message and the sender is just going to + + + align:start position:0% +message and the sender is just going to +retry transmitting messages over and + + align:start position:0% +retry transmitting messages over and + + + align:start position:0% +retry transmitting messages over and +over and over again until the message + + align:start position:0% +over and over again until the message + + + align:start position:0% +over and over again until the message +actually gets through so in this case uh + + align:start position:0% +actually gets through so in this case uh + + + align:start position:0% +actually gets through so in this case uh +it sets this timer for time + + align:start position:0% +it sets this timer for time + + + align:start position:0% +it sets this timer for time +tr1 uh at the same instant that it sends + + align:start position:0% +tr1 uh at the same instant that it sends + + + align:start position:0% +tr1 uh at the same instant that it sends +out this message and then when time tr1 + + align:start position:0% +out this message and then when time tr1 + + + align:start position:0% +out this message and then when time tr1 +arrives and the message hasn't yet been + + align:start position:0% +arrives and the message hasn't yet been + + + align:start position:0% +arrives and the message hasn't yet been +acknowledged the sender is so after this + + align:start position:0% +acknowledged the sender is so after this + + + align:start position:0% +acknowledged the sender is so after this +this retry interval time the sender is + + align:start position:0% +this retry interval time the sender is + + + align:start position:0% +this retry interval time the sender is +just going to try and retransmit the + + align:start position:0% +just going to try and retransmit the + + + align:start position:0% +just going to try and retransmit the +message so now in this case the receiver + + align:start position:0% +message so now in this case the receiver + + + align:start position:0% +message so now in this case the receiver +has successfully received the message + + align:start position:0% +has successfully received the message + + + align:start position:0% +has successfully received the message +but notice that the sender doesn't + + align:start position:0% +but notice that the sender doesn't + + + align:start position:0% +but notice that the sender doesn't +actually know that the receiver has + + align:start position:0% +actually know that the receiver has + + + align:start position:0% +actually know that the receiver has +received it it's we can see it from the + + align:start position:0% +received it it's we can see it from the + + + align:start position:0% +received it it's we can see it from the +diagram but there's been no feedback + + align:start position:0% +diagram but there's been no feedback + + + align:start position:0% +diagram but there's been no feedback +that has come from the receiver yet and + + align:start position:0% +that has come from the receiver yet and + + + align:start position:0% +that has come from the receiver yet and +now suppose that the receiver sends its + + align:start position:0% +now suppose that the receiver sends its + + + align:start position:0% +now suppose that the receiver sends its +acknowledgement for this message and + + align:start position:0% +acknowledgement for this message and + + + align:start position:0% +acknowledgement for this message and +along the way the acknowledgement gets + + align:start position:0% +along the way the acknowledgement gets + + + align:start position:0% +along the way the acknowledgement gets +lost right so this could happen just as + + align:start position:0% +lost right so this could happen just as + + + align:start position:0% +lost right so this could happen just as +easily as the original message being + + align:start position:0% +easily as the original message being + + + align:start position:0% +easily as the original message being +sent out um so now in this case our + + align:start position:0% +sent out um so now in this case our + + + align:start position:0% +sent out um so now in this case our +retry mechanism continues to + + align:start position:0% +retry mechanism continues to + + + align:start position:0% +retry mechanism continues to +work and after this retry interval and + + align:start position:0% +work and after this retry interval and + + + align:start position:0% +work and after this retry interval and +time tr2 is reached the message gets + + align:start position:0% +time tr2 is reached the message gets + + + align:start position:0% +time tr2 is reached the message gets +resent and then in this case finally the + + align:start position:0% +resent and then in this case finally the + + + align:start position:0% +resent and then in this case finally the +message is actually received and we can + + align:start position:0% +message is actually received and we can + + + align:start position:0% +message is actually received and we can +go ahead and remove it from the pending + + align:start position:0% +go ahead and remove it from the pending + + + align:start position:0% +go ahead and remove it from the pending +message list so this process the + + align:start position:0% +message list so this process the + + + align:start position:0% +message list so this process the +receiver the sender is just going to + + align:start position:0% +receiver the sender is just going to + + + align:start position:0% +receiver the sender is just going to +continually try retry transmitting these + + align:start position:0% +continually try retry transmitting these + + + align:start position:0% +continually try retry transmitting these +messages until it gets an + + align:start position:0% +messages until it gets an + + + align:start position:0% +messages until it gets an +acknowledgement from the receiver it's + + align:start position:0% +acknowledgement from the receiver it's + + + align:start position:0% +acknowledgement from the receiver it's +actually in practice it's the case that + + align:start position:0% +actually in practice it's the case that + + + align:start position:0% +actually in practice it's the case that +the receiver will only retry a fixed + + align:start position:0% +the receiver will only retry a fixed + + + align:start position:0% +the receiver will only retry a fixed +number of times because as we said it is + + align:start position:0% +number of times because as we said it is + + + align:start position:0% +number of times because as we said it is +there are certain situations in which + + align:start position:0% +there are certain situations in which + + + align:start position:0% +there are certain situations in which +the network can just be simply + + align:start position:0% +the network can just be simply + + + align:start position:0% +the network can just be simply +unavailable suppose there's no network + + align:start position:0% +unavailable suppose there's no network + + + align:start position:0% +unavailable suppose there's no network +connection ail aailable to the to the + + align:start position:0% +connection ail aailable to the to the + + + align:start position:0% +connection ail aailable to the to the +transmitter to the sender of course at + + align:start position:0% +transmitter to the sender of course at + + + align:start position:0% +transmitter to the sender of course at +some point it's going to make sense for + + align:start position:0% +some point it's going to make sense for + + + align:start position:0% +some point it's going to make sense for +it to give up and stop trying and then + + align:start position:0% +it to give up and stop trying and then + + + align:start position:0% +it to give up and stop trying and then +it will report an error to the user the + + align:start position:0% +it will report an error to the user the + + + align:start position:0% +it will report an error to the user the +other thing to notice about this + + align:start position:0% +other thing to notice about this + + + align:start position:0% +other thing to notice about this +protocol that we've described here is + + align:start position:0% +protocol that we've described here is + + + align:start position:0% +protocol that we've described here is +that the receiver has received two + + align:start position:0% +that the receiver has received two + + + align:start position:0% +that the receiver has received two +copies of this + + align:start position:0% +copies of this + + + align:start position:0% +copies of this +message so that seems a little bit + + align:start position:0% +message so that seems a little bit + + + align:start position:0% +message so that seems a little bit +problematic right the rece if if this is + + align:start position:0% +problematic right the rece if if this is + + + align:start position:0% +problematic right the rece if if this is +a message that says withdraw $10,000 + + align:start position:0% +a message that says withdraw $10,000 + + + align:start position:0% +a message that says withdraw $10,000 +from your bank account we don't probably + + align:start position:0% +from your bank account we don't probably + + + align:start position:0% +from your bank account we don't probably +want to process that message twice right + + align:start position:0% +want to process that message twice right + + + align:start position:0% +want to process that message twice right +that might be problematic so + + align:start position:0% +that might be problematic so + + + align:start position:0% +that might be problematic so +uh that that's the so we're going to + + align:start position:0% +uh that that's the so we're going to + + + align:start position:0% +uh that that's the so we're going to +address that issue when we get to + + align:start position:0% +address that issue when we get to + + + align:start position:0% +address that issue when we get to +talking about at most once delivery but + + align:start position:0% +talking about at most once delivery but + + + align:start position:0% +talking about at most once delivery but +just bear in mind for now that these + + align:start position:0% +just bear in mind for now that these + + + align:start position:0% +just bear in mind for now that these +duplicates can occur there's another + + align:start position:0% +duplicates can occur there's another + + + align:start position:0% +duplicates can occur there's another +subtlety with this protocol that I've + + align:start position:0% +subtlety with this protocol that I've + + + align:start position:0% +subtlety with this protocol that I've +described here though um does anybody + + align:start position:0% +described here though um does anybody + + + align:start position:0% +described here though um does anybody +see does anybody see something that's a + + align:start position:0% +see does anybody see something that's a + + + align:start position:0% +see does anybody see something that's a +little bit suspicious about this diagram + + align:start position:0% +little bit suspicious about this diagram + + + align:start position:0% +little bit suspicious about this diagram +that I've shown here a little bit a + + align:start position:0% +that I've shown here a little bit a + + + align:start position:0% +that I've shown here a little bit a +little bit weird about the way I've + + align:start position:0% +little bit weird about the way I've + + + align:start position:0% +little bit weird about the way I've +shown it + + align:start position:0% + + + + align:start position:0% + +yeah okay right good so there's this + + align:start position:0% +yeah okay right good so there's this + + + align:start position:0% +yeah okay right good so there's this +question about how are you going to set + + align:start position:0% +question about how are you going to set + + + align:start position:0% +question about how are you going to set +the retry interval for these messag + + align:start position:0% +the retry interval for these messag + + + align:start position:0% +the retry interval for these messag +mesages right so what I've shown here is + + align:start position:0% +mesages right so what I've shown here is + + + align:start position:0% +mesages right so what I've shown here is +that the retry interval is short and the + + align:start position:0% +that the retry interval is short and the + + + align:start position:0% +that the retry interval is short and the +first time we sent and received this + + align:start position:0% +first time we sent and received this + + + align:start position:0% +first time we sent and received this +message in fact the time that it took us + + align:start position:0% +message in fact the time that it took us + + + align:start position:0% +message in fact the time that it took us +to do that appeared to be quite quite + + align:start position:0% +to do that appeared to be quite quite + + + align:start position:0% +to do that appeared to be quite quite +long on this diagram right and so in in + + align:start position:0% +long on this diagram right and so in in + + + align:start position:0% +long on this diagram right and so in in +fact what would have happened if we had + + align:start position:0% +fact what would have happened if we had + + + align:start position:0% +fact what would have happened if we had +if we had done this is that the sender + + align:start position:0% +if we had done this is that the sender + + + align:start position:0% +if we had done this is that the sender +would have retransmitted this message + + align:start position:0% +would have retransmitted this message + + + align:start position:0% +would have retransmitted this message +several times even though the receiver + + align:start position:0% +several times even though the receiver + + + align:start position:0% +several times even though the receiver +had actually received the message and + + align:start position:0% +had actually received the message and + + + align:start position:0% +had actually received the message and +and the the acknowledgement was on the + + align:start position:0% +and the the acknowledgement was on the + + + align:start position:0% +and the the acknowledgement was on the +way back to way back to us correctly + + align:start position:0% +way back to way back to us correctly + + + align:start position:0% +way back to way back to us correctly +it's just that we uh didn't wait long + + align:start position:0% +it's just that we uh didn't wait long + + + align:start position:0% +it's just that we uh didn't wait long +enough for that acknowledgement to come + + align:start position:0% +enough for that acknowledgement to come + + + align:start position:0% +enough for that acknowledgement to come +back to us so there's this question + + align:start position:0% +back to us so there's this question + + + align:start position:0% +back to us so there's this question +about well how are we going to pick this + + align:start position:0% +about well how are we going to pick this + + + align:start position:0% +about well how are we going to pick this +timer interval so that it's appropriate + + align:start position:0% +timer interval so that it's appropriate + + + align:start position:0% +timer interval so that it's appropriate +for the network that we're running + + align:start position:0% +for the network that we're running + + + align:start position:0% +for the network that we're running +on + + align:start position:0% +on + + + align:start position:0% +on +and this this turns out to be kind of an + + align:start position:0% +and this this turns out to be kind of an + + + align:start position:0% +and this this turns out to be kind of an +interesting and challenging + + align:start position:0% + + + + align:start position:0% + +problem + + align:start position:0% +problem + + + align:start position:0% +problem +so there's this question about how long + + align:start position:0% +so there's this question about how long + + + align:start position:0% +so there's this question about how long +do we wait before retry + + align:start position:0% + + + + align:start position:0% + +so a simple answer for how long we + + align:start position:0% +so a simple answer for how long we + + + align:start position:0% +so a simple answer for how long we +should wait is well however whatever the + + align:start position:0% +should wait is well however whatever the + + + align:start position:0% +should wait is well however whatever the +roundtrip time of the network is however + + align:start position:0% +roundtrip time of the network is however + + + align:start position:0% +roundtrip time of the network is however +long it takes for a message to reach the + + align:start position:0% +long it takes for a message to reach the + + + align:start position:0% +long it takes for a message to reach the +receiver and then uh for the + + align:start position:0% +receiver and then uh for the + + + align:start position:0% +receiver and then uh for the +acknowledgement to be sent back to the + + align:start position:0% +acknowledgement to be sent back to the + + + align:start position:0% +acknowledgement to be sent back to the +sender so we call that the round trip + + align:start position:0% +sender so we call that the round trip + + + align:start position:0% +sender so we call that the round trip +time or the rtt um so we'd like to wait + + align:start position:0% +time or the rtt um so we'd like to wait + + + align:start position:0% +time or the rtt um so we'd like to wait +at least rtt + + align:start position:0% +at least rtt + + + align:start position:0% +at least rtt +right but the problem is that rtt is uh + + align:start position:0% +right but the problem is that rtt is uh + + + align:start position:0% +right but the problem is that rtt is uh +this round trip time is not necessarily + + align:start position:0% +this round trip time is not necessarily + + + align:start position:0% +this round trip time is not necessarily +going to be constant over the whole + + align:start position:0% +going to be constant over the whole + + + align:start position:0% +going to be constant over the whole +lifetime of the network so let me show + + align:start position:0% +lifetime of the network so let me show + + + align:start position:0% +lifetime of the network so let me show +you you what I mean this is a a plot of + + align:start position:0% +you you what I mean this is a a plot of + + + align:start position:0% +you you what I mean this is a a plot of +round of some round trip time + + align:start position:0% +round of some round trip time + + + align:start position:0% +round of some round trip time +information from a wide area wireless + + align:start position:0% +information from a wide area wireless + + + align:start position:0% +information from a wide area wireless +link so these uh transit times are very + + align:start position:0% +link so these uh transit times are very + + + align:start position:0% +link so these uh transit times are very +long here over this link they're sort of + + align:start position:0% +long here over this link they're sort of + + + align:start position:0% +long here over this link they're sort of +order of thousands of Mill thousands of + + align:start position:0% +order of thousands of Mill thousands of + + + align:start position:0% +order of thousands of Mill thousands of +milliseconds um so the long so the + + align:start position:0% +milliseconds um so the long so the + + + align:start position:0% +milliseconds um so the long so the +average transmission time is 2.4 seconds + + align:start position:0% +average transmission time is 2.4 seconds + + + align:start position:0% +average transmission time is 2.4 seconds +here the standard deviation the sort of + + align:start position:0% +here the standard deviation the sort of + + + align:start position:0% +here the standard deviation the sort of +which is a measure of the variance + + align:start position:0% +which is a measure of the variance + + + align:start position:0% +which is a measure of the variance +between these different samples um is is + + align:start position:0% +between these different samples um is is + + + align:start position:0% +between these different samples um is is +1.5 seconds so there's a lot of sort of + + align:start position:0% +1.5 seconds so there's a lot of sort of + + + align:start position:0% +1.5 seconds so there's a lot of sort of +bouncing around of this signal and it's + + align:start position:0% +bouncing around of this signal and it's + + + align:start position:0% +bouncing around of this signal and it's +not so it's not as though the roundtrip + + align:start position:0% +not so it's not as though the roundtrip + + + align:start position:0% +not so it's not as though the roundtrip +time is just a it's saying that the + + align:start position:0% +time is just a it's saying that the + + + align:start position:0% +time is just a it's saying that the +round expecting the roundtrip time to + + align:start position:0% +round expecting the roundtrip time to + + + align:start position:0% +round expecting the roundtrip time to +simply be a single constant value isn't + + align:start position:0% +simply be a single constant value isn't + + + align:start position:0% +simply be a single constant value isn't +a very good idea so if we want to set + + align:start position:0% +a very good idea so if we want to set + + + align:start position:0% +a very good idea so if we want to set +the timeout just to + + align:start position:0% + + + + align:start position:0% + +rtt that's going to cause us you know if + + align:start position:0% +rtt that's going to cause us you know if + + + align:start position:0% +rtt that's going to cause us you know if +you think about this for a minute if we + + align:start position:0% +you think about this for a minute if we + + + align:start position:0% +you think about this for a minute if we +said it just to be rtt uh which is say + + align:start position:0% +said it just to be rtt uh which is say + + + align:start position:0% +said it just to be rtt uh which is say +for example maybe the average uh the the + + align:start position:0% +for example maybe the average uh the the + + + align:start position:0% +for example maybe the average uh the the +the average roundtrip time that we've + + align:start position:0% +the average roundtrip time that we've + + + align:start position:0% +the average roundtrip time that we've +measured in a signal like this well half + + align:start position:0% +measured in a signal like this well half + + + align:start position:0% +measured in a signal like this well half +the time we're going to be uh well uh + + align:start position:0% +the time we're going to be uh well uh + + + align:start position:0% +the time we're going to be uh well uh +you know some significant proportion of + + align:start position:0% +you know some significant proportion of + + + align:start position:0% +you know some significant proportion of +the time we're going to be above the the + + align:start position:0% +the time we're going to be above the the + + + align:start position:0% +the time we're going to be above the the +rtt right um because you know if just + + align:start position:0% +rtt right um because you know if just + + + align:start position:0% +rtt right um because you know if just +just picking the average there's going + + align:start position:0% +just picking the average there's going + + + align:start position:0% +just picking the average there's going +to be many samples that are above the + + align:start position:0% +to be many samples that are above the + + + align:start position:0% +to be many samples that are above the +rtt um so instead we want to do rtt plus + + align:start position:0% +rtt um so instead we want to do rtt plus + + + align:start position:0% +rtt um so instead we want to do rtt plus +some slop value something that's sort of + + align:start position:0% +some slop value something that's sort of + + + align:start position:0% +some slop value something that's sort of +some adjustment factor that uh gets us a + + align:start position:0% +some adjustment factor that uh gets us a + + + align:start position:0% +some adjustment factor that uh gets us a +little bit gives us a little bit of + + align:start position:0% +little bit gives us a little bit of + + + align:start position:0% +little bit gives us a little bit of +extra sort of leeway in how long we wait + + align:start position:0% +extra sort of leeway in how long we wait + + + align:start position:0% +extra sort of leeway in how long we wait +but of course we don't want to wait too + + align:start position:0% +but of course we don't want to wait too + + + align:start position:0% +but of course we don't want to wait too +long because if we wait too long then + + align:start position:0% +long because if we wait too long then + + + align:start position:0% +long because if we wait too long then +we're not going to actually retransmit + + align:start position:0% +we're not going to actually retransmit + + + align:start position:0% +we're not going to actually retransmit +messages that were in fact + + align:start position:0% +messages that were in fact + + + align:start position:0% +messages that were in fact +lost okay so let's look at how so that's + + align:start position:0% +lost okay so let's look at how so that's + + + align:start position:0% +lost okay so let's look at how so that's +sort of a simple intuitive argument for + + align:start position:0% +sort of a simple intuitive argument for + + + align:start position:0% +sort of a simple intuitive argument for +how we should do this um what I want to + + align:start position:0% +how we should do this um what I want to + + + align:start position:0% +how we should do this um what I want to +do now is just quickly take you through + + align:start position:0% +do now is just quickly take you through + + + align:start position:0% +do now is just quickly take you through +the way that these round trip times are + + align:start position:0% +the way that these round trip times are + + + align:start position:0% +the way that these round trip times are +done uh actually are the these roundt + + align:start position:0% +done uh actually are the these roundt + + + align:start position:0% +done uh actually are the these roundt +trip times are estimated in the TCP + + align:start position:0% +trip times are estimated in the TCP + + + align:start position:0% +trip times are estimated in the TCP +protocol um and the way this is done is + + align:start position:0% +protocol um and the way this is done is + + + align:start position:0% +protocol um and the way this is done is +really pretty pretty + + align:start position:0% +really pretty pretty + + + align:start position:0% +really pretty pretty +straightforward the idea is that we want + + align:start position:0% +straightforward the idea is that we want + + + align:start position:0% +straightforward the idea is that we want +to estimate the um the the average rtt + + align:start position:0% +to estimate the um the the average rtt + + + align:start position:0% +to estimate the um the the average rtt +so one way that we could and then we + + align:start position:0% +so one way that we could and then we + + + align:start position:0% +so one way that we could and then we +also want to estimate the sort of + + align:start position:0% +also want to estimate the sort of + + + align:start position:0% +also want to estimate the sort of +variance which is going to be our slop + + align:start position:0% +variance which is going to be our slop + + + align:start position:0% +variance which is going to be our slop +number okay the way that we want we we + + align:start position:0% +number okay the way that we want we we + + + align:start position:0% +number okay the way that we want we we +so one way we could compute the average + + align:start position:0% +so one way we could compute the average + + + align:start position:0% +so one way we could compute the average +rtt is to keep this sort of set of + + align:start position:0% +rtt is to keep this sort of set of + + + align:start position:0% +rtt is to keep this sort of set of +samples of all the roundtrip time so I + + align:start position:0% +samples of all the roundtrip time so I + + + align:start position:0% +samples of all the roundtrip time so I +have maybe 20 points I have whatever it + + align:start position:0% +have maybe 20 points I have whatever it + + + align:start position:0% +have maybe 20 points I have whatever it +is 20 points here they're samples of the + + align:start position:0% +is 20 points here they're samples of the + + + align:start position:0% +is 20 points here they're samples of the +round trip time so I could take this uh + + align:start position:0% +round trip time so I could take this uh + + + align:start position:0% +round trip time so I could take this uh +set of 20 numbers and compute the + + align:start position:0% +set of 20 numbers and compute the + + + align:start position:0% +set of 20 numbers and compute the +average of them and I could recompute + + align:start position:0% +average of them and I could recompute + + + align:start position:0% +average of them and I could recompute +the average every time a new number + + align:start position:0% +the average every time a new number + + + align:start position:0% +the average every time a new number +comes in the problem with that is that I + + align:start position:0% +comes in the problem with that is that I + + + align:start position:0% +comes in the problem with that is that I +have to keep this window of all the + + align:start position:0% +have to keep this window of all the + + + align:start position:0% +have to keep this window of all the +averages around so instead what we want + + align:start position:0% +averages around so instead what we want + + + align:start position:0% +averages around so instead what we want +to do is to have some way of sort of + + align:start position:0% +to do is to have some way of sort of + + + align:start position:0% +to do is to have some way of sort of +updating the average without having to + + align:start position:0% +updating the average without having to + + + align:start position:0% +updating the average without having to +keep all the previous values around and + + align:start position:0% +keep all the previous values around and + + + align:start position:0% +keep all the previous values around and +there's a simple technique that's + + align:start position:0% +there's a simple technique that's + + + align:start position:0% +there's a simple technique that's +commonly used uh in computer systems + + align:start position:0% +commonly used uh in computer systems + + + align:start position:0% +commonly used uh in computer systems +called an exponentially weighted moving + + align:start position:0% +called an exponentially weighted moving + + + align:start position:0% +called an exponentially weighted moving +average which is a way that we can keep + + align:start position:0% +average which is a way that we can keep + + + align:start position:0% +average which is a way that we can keep +track of this average with just a single + + align:start position:0% +track of this average with just a single + + + align:start position:0% +track of this average with just a single +number so this is the + + align:start position:0% + + + + align:start position:0% + +ewma what the ewma does is it given a + + align:start position:0% +ewma what the ewma does is it given a + + + align:start position:0% +ewma what the ewma does is it given a +set of samples + + align:start position:0% + + + + align:start position:0% + +say S1 up to some most recent sample s + + align:start position:0% +say S1 up to some most recent sample s + + + align:start position:0% +say S1 up to some most recent sample s +new what the ewma does is computes the + + align:start position:0% +new what the ewma does is computes the + + + align:start position:0% +new what the ewma does is computes the +RT uh uh incrementally adjusts the rtt + + align:start position:0% +RT uh uh incrementally adjusts the rtt + + + align:start position:0% +RT uh uh incrementally adjusts the rtt +according to the following formula says + + align:start position:0% +according to the following formula says + + + align:start position:0% +according to the following formula says +the new rtt is going to be equal to 1 + + align:start position:0% +the new rtt is going to be equal to 1 + + + align:start position:0% +the new rtt is going to be equal to 1 +minus Alpha so these samples are samples + + align:start position:0% +minus Alpha so these samples are samples + + + align:start position:0% +minus Alpha so these samples are samples +uh of round trip times okay like this + + align:start position:0% +uh of round trip times okay like this + + + align:start position:0% +uh of round trip times okay like this +number here so these are numbers the + + align:start position:0% +number here so these are numbers the + + + align:start position:0% +number here so these are numbers the +numbers that we've observed over time as + + align:start position:0% +numbers that we've observed over time as + + + align:start position:0% +numbers that we've observed over time as +messages have been trans committed back + + align:start position:0% +messages have been trans committed back + + + align:start position:0% +messages have been trans committed back +and forth we're going to take some + + align:start position:0% +and forth we're going to take some + + + align:start position:0% +and forth we're going to take some +number 1us Alpha time uh s new our our + + align:start position:0% +number 1us Alpha time uh s new our our + + + align:start position:0% +number 1us Alpha time uh s new our our +newly observed roundtrip time and we're + + align:start position:0% +newly observed roundtrip time and we're + + + align:start position:0% +newly observed roundtrip time and we're +going to add to that some Alpha times + + align:start position:0% +going to add to that some Alpha times + + + align:start position:0% +going to add to that some Alpha times +the + + align:start position:0% +the + + + align:start position:0% +the +old roundtrip + + align:start position:0% +old roundtrip + + + align:start position:0% +old roundtrip +time okay so what this does is basically + + align:start position:0% +time okay so what this does is basically + + + align:start position:0% +time okay so what this does is basically +it adds into the it it computes the rtt + + align:start position:0% +it adds into the it it computes the rtt + + + align:start position:0% +it adds into the it it computes the rtt +as some weighted combination of the old + + align:start position:0% +as some weighted combination of the old + + + align:start position:0% +as some weighted combination of the old +roundtrip time and the newly observed + + align:start position:0% +roundtrip time and the newly observed + + + align:start position:0% +roundtrip time and the newly observed +roundtrip time and if you think about + + align:start position:0% +roundtrip time and if you think about + + + align:start position:0% +roundtrip time and if you think about +this for a minute if we make alpha if so + + align:start position:0% +this for a minute if we make alpha if so + + + align:start position:0% +this for a minute if we make alpha if so +Alpha is in this case is going to be + + align:start position:0% +Alpha is in this case is going to be + + + align:start position:0% +Alpha is in this case is going to be +some number between zero and + + align:start position:0% +some number between zero and + + + align:start position:0% +some number between zero and +one um and if you think about Alpha + + align:start position:0% +one um and if you think about Alpha + + + align:start position:0% +one um and if you think about Alpha +being zero if Alpha is zero then the new + + align:start position:0% +being zero if Alpha is zero then the new + + + align:start position:0% +being zero if Alpha is zero then the new +art roundtrip the newly computed + + align:start position:0% +art roundtrip the newly computed + + + align:start position:0% +art roundtrip the newly computed +roundtrip time is just equal to s new + + align:start position:0% +roundtrip time is just equal to s new + + + align:start position:0% +roundtrip time is just equal to s new +right and if Alpha is one then the newly + + align:start position:0% +right and if Alpha is one then the newly + + + align:start position:0% +right and if Alpha is one then the newly +uh the newly computed roundtrip time is + + align:start position:0% +uh the newly computed roundtrip time is + + + align:start position:0% +uh the newly computed roundtrip time is +just equal to whatever the old round + + align:start position:0% +just equal to whatever the old round + + + align:start position:0% +just equal to whatever the old round +trip time was right so the new sample + + align:start position:0% +trip time was right so the new sample + + + align:start position:0% +trip time was right so the new sample +has no effect so as we move veryy Alpha + + align:start position:0% +has no effect so as we move veryy Alpha + + + align:start position:0% +has no effect so as we move veryy Alpha +between these two extremes we're going + + align:start position:0% +between these two extremes we're going + + + align:start position:0% +between these two extremes we're going +to wait the new roundtrip time more or + + align:start position:0% +to wait the new roundtrip time more or + + + align:start position:0% +to wait the new roundtrip time more or +less heavily okay so this is not going + + align:start position:0% +less heavily okay so this is not going + + + align:start position:0% +less heavily okay so this is not going +to perfectly compute the average of the + + align:start position:0% +to perfectly compute the average of the + + + align:start position:0% +to perfectly compute the average of the +samples over time but it's going to give + + align:start position:0% +samples over time but it's going to give + + + align:start position:0% +samples over time but it's going to give +us some estimate that sort of varies + + align:start position:0% +us some estimate that sort of varies + + + align:start position:0% +us some estimate that sort of varies +with + + align:start position:0% +with + + + align:start position:0% +with +time the other thing we said we wanted + + align:start position:0% +time the other thing we said we wanted + + + align:start position:0% +time the other thing we said we wanted +to is compute what this slop factor is + + align:start position:0% +to is compute what this slop factor is + + + align:start position:0% +to is compute what this slop factor is +and this slop factor is just going to be + + align:start position:0% +and this slop factor is just going to be + + + align:start position:0% +and this slop factor is just going to be +we just want this to be some measure of + + align:start position:0% +we just want this to be some measure of + + + align:start position:0% +we just want this to be some measure of +the variance of this signal so in + + align:start position:0% +the variance of this signal so in + + + align:start position:0% +the variance of this signal so in +particular what we want it to meet is + + align:start position:0% +particular what we want it to meet is + + + align:start position:0% +particular what we want it to meet is +uh just going to push this up so can + + align:start position:0% +uh just going to push this up so can + + + align:start position:0% +uh just going to push this up so can +write slop is going to be equal to uh + + align:start position:0% +write slop is going to be equal to uh + + + align:start position:0% +write slop is going to be equal to uh +some Factor beta times some variance of + + align:start position:0% +some Factor beta times some variance of + + + align:start position:0% +some Factor beta times some variance of +this some some some number that's the + + align:start position:0% +this some some some number that's the + + + align:start position:0% +this some some some number that's the +variance and what I mean by variance is + + align:start position:0% +variance and what I mean by variance is + + + align:start position:0% +variance and what I mean by variance is +simply the + + align:start position:0% +simply the + + + align:start position:0% +simply the +difference + + align:start position:0% +difference + + + align:start position:0% +difference +between the + + align:start position:0% + + + + align:start position:0% + +predicted and actual roundt trip + + align:start position:0% +predicted and actual roundt trip + + + align:start position:0% +predicted and actual roundt trip +times so if our formula says that this + + align:start position:0% +times so if our formula says that this + + + align:start position:0% +times so if our formula says that this +round trip time given a sample uh the + + align:start position:0% +round trip time given a sample uh the + + + align:start position:0% +round trip time given a sample uh the +the round trip time uh should be you + + align:start position:0% +the round trip time uh should be you + + + align:start position:0% +the round trip time uh should be you +know 10 milliseconds and the next sample + + align:start position:0% +know 10 milliseconds and the next sample + + + align:start position:0% +know 10 milliseconds and the next sample +comes in and it says the you know actual + + align:start position:0% +comes in and it says the you know actual + + + align:start position:0% +comes in and it says the you know actual +roundtrip time was 20 milliseconds then + + align:start position:0% +roundtrip time was 20 milliseconds then + + + align:start position:0% +roundtrip time was 20 milliseconds then +the variance we would we would say that + + align:start position:0% +the variance we would we would say that + + + align:start position:0% +the variance we would we would say that +the sort of this deviation the + + align:start position:0% +the sort of this deviation the + + + align:start position:0% +the sort of this deviation the +difference between those two things + + align:start position:0% +difference between those two things + + + align:start position:0% +difference between those two things +would be 10 milliseconds okay so let's + + align:start position:0% +would be 10 milliseconds okay so let's + + + align:start position:0% +would be 10 milliseconds okay so let's +see how this works I'll show you now the + + align:start position:0% +see how this works I'll show you now the + + + align:start position:0% +see how this works I'll show you now the +pseudo code for how this actually works + + align:start position:0% +pseudo code for how this actually works + + + align:start position:0% +pseudo code for how this actually works +in the internet um and it should be + + align:start position:0% +in the internet um and it should be + + + align:start position:0% +in the internet um and it should be +pretty clear what's going on so what + + align:start position:0% +pretty clear what's going on so what + + + align:start position:0% +pretty clear what's going on so what +we're going to do is we're going to keep + + align:start position:0% +we're going to do is we're going to keep + + + align:start position:0% +we're going to do is we're going to keep +a set of variables called one of which + + align:start position:0% +a set of variables called one of which + + + align:start position:0% +a set of variables called one of which +is called SRT so this is this is ex + + align:start position:0% +is called SRT so this is this is ex + + + align:start position:0% +is called SRT so this is this is ex +almost exactly what the TCP protocol + + align:start position:0% +almost exactly what the TCP protocol + + + align:start position:0% +almost exactly what the TCP protocol +does so we're going to have srtt which + + align:start position:0% +does so we're going to have srtt which + + + align:start position:0% +does so we're going to have srtt which +is the current roundtrip the roundt trip + + align:start position:0% +is the current roundtrip the roundt trip + + + align:start position:0% +is the current roundtrip the roundt trip +time estimate and then we're going to + + align:start position:0% +time estimate and then we're going to + + + align:start position:0% +time estimate and then we're going to +have this thing we're call RTD which is + + align:start position:0% +have this thing we're call RTD which is + + + align:start position:0% +have this thing we're call RTD which is +the deviation the current estimate of + + align:start position:0% +the deviation the current estimate of + + + align:start position:0% +the deviation the current estimate of +the sort of variance of this uh round + + align:start position:0% +the sort of variance of this uh round + + + align:start position:0% +the sort of variance of this uh round +trip time and we're going to initialize + + align:start position:0% +trip time and we're going to initialize + + + align:start position:0% +trip time and we're going to initialize +these two numbers to be something that + + align:start position:0% +these two numbers to be something that + + + align:start position:0% +these two numbers to be something that +seems reasonable we might say the + + align:start position:0% +seems reasonable we might say the + + + align:start position:0% +seems reasonable we might say the +roundtrip time is 100 milliseconds and + + align:start position:0% +roundtrip time is 100 milliseconds and + + + align:start position:0% +roundtrip time is 100 milliseconds and +this rtt D is 50 + + align:start position:0% +this rtt D is 50 + + + align:start position:0% +this rtt D is 50 +milliseconds and now what we're going to + + align:start position:0% +milliseconds and now what we're going to + + + align:start position:0% +milliseconds and now what we're going to +do is we're going to just every time new + + align:start position:0% +do is we're going to just every time new + + + align:start position:0% +do is we're going to just every time new +one of these samples of the roundtrip + + align:start position:0% +one of these samples of the roundtrip + + + align:start position:0% +one of these samples of the roundtrip +time comes in we're going to call this + + align:start position:0% +time comes in we're going to call this + + + align:start position:0% +time comes in we're going to call this +Cal rtt function what the Cal rtt + + align:start position:0% +Cal rtt function what the Cal rtt + + + align:start position:0% +Cal rtt function what the Cal rtt +function is going to do it's going to + + align:start position:0% +function is going to do it's going to + + + align:start position:0% +function is going to do it's going to +update the old uh update the the round + + align:start position:0% +update the old uh update the the round + + + align:start position:0% +update the old uh update the the round +trip time using this formula that we've + + align:start position:0% +trip time using this formula that we've + + + align:start position:0% +trip time using this formula that we've +seen here and in the case of TCP people + + align:start position:0% +seen here and in the case of TCP people + + + align:start position:0% +seen here and in the case of TCP people +have sort of experimented with different + + align:start position:0% +have sort of experimented with different + + + align:start position:0% +have sort of experimented with different +values and you know there the sort of + + align:start position:0% +values and you know there the sort of + + + align:start position:0% +values and you know there the sort of +the number that is typically used is + + align:start position:0% +the number that is typically used is + + + align:start position:0% +the number that is typically used is +that you sort of 18 uh a number that is + + align:start position:0% +that you sort of 18 uh a number that is + + + align:start position:0% +that you sort of 18 uh a number that is +commonly used is that uh sort of use + + align:start position:0% +commonly used is that uh sort of use + + + align:start position:0% +commonly used is that uh sort of use +Alpha you set Alpha to be 7 es so that + + align:start position:0% +Alpha you set Alpha to be 7 es so that + + + align:start position:0% +Alpha you set Alpha to be 7 es so that +means that you sort of add in 1/8 of the + + align:start position:0% +means that you sort of add in 1/8 of the + + + align:start position:0% +means that you sort of add in 1/8 of the +uh new number and use 78 of the old + + align:start position:0% +uh new number and use 78 of the old + + + align:start position:0% +uh new number and use 78 of the old +number so this is not going to the a new + + align:start position:0% +number so this is not going to the a new + + + align:start position:0% +number so this is not going to the a new +number that varies a lot isn't going to + + align:start position:0% +number that varies a lot isn't going to + + + align:start position:0% +number that varies a lot isn't going to +change the overall uh the overall round + + align:start position:0% +change the overall uh the overall round + + + align:start position:0% +change the overall uh the overall round +trip time estimate of the round time + + align:start position:0% +trip time estimate of the round time + + + align:start position:0% +trip time estimate of the round time +trip time terribly dramatically and + + align:start position:0% +trip time terribly dramatically and + + + align:start position:0% +trip time terribly dramatically and +we're going to compute the deviation as + + align:start position:0% +we're going to compute the deviation as + + + align:start position:0% +we're going to compute the deviation as +I've shown here we're going to take the + + align:start position:0% +I've shown here we're going to take the + + + align:start position:0% +I've shown here we're going to take the +absolute value of it um and then we're + + align:start position:0% +absolute value of it um and then we're + + + align:start position:0% +absolute value of it um and then we're +going to keep some running estimate of + + align:start position:0% +going to keep some running estimate of + + + align:start position:0% +going to keep some running estimate of +the roundtrip time again using one of + + align:start position:0% +the roundtrip time again using one of + + + align:start position:0% +the roundtrip time again using one of +these sort of exponentially weighted + + align:start position:0% +these sort of exponentially weighted + + + align:start position:0% +these sort of exponentially weighted +things so in this case we're going to + + align:start position:0% +things so in this case we're going to + + + align:start position:0% +things so in this case we're going to +wait with + + align:start position:0% +wait with + + + align:start position:0% +wait with +with this uh setting the the value of + + align:start position:0% +with this uh setting the the value of + + + align:start position:0% +with this uh setting the the value of +the weight here to + + align:start position:0% +the weight here to + + + align:start position:0% +the weight here to +3/4 okay so that's a simple way to + + align:start position:0% +3/4 okay so that's a simple way to + + + align:start position:0% +3/4 okay so that's a simple way to +compute the round trip time and now + + align:start position:0% +compute the round trip time and now + + + align:start position:0% +compute the round trip time and now +given the the computation of the round + + align:start position:0% +given the the computation of the round + + + align:start position:0% +given the the computation of the round +trip time what we need to do is to + + align:start position:0% +trip time what we need to do is to + + + align:start position:0% +trip time what we need to do is to +compute the timeout value that we should + + align:start position:0% +compute the timeout value that we should + + + align:start position:0% +compute the timeout value that we should +use so in uh what we said is the the + + align:start position:0% +use so in uh what we said is the the + + + align:start position:0% +use so in uh what we said is the the +timeout value we want to use is rtt plus + + align:start position:0% +timeout value we want to use is rtt plus + + + align:start position:0% +timeout value we want to use is rtt plus +some slop and uh in the case of TCP a + + align:start position:0% +some slop and uh in the case of TCP a + + + align:start position:0% +some slop and uh in the case of TCP a +commonly used slop value might be four + + align:start position:0% +commonly used slop value might be four + + + align:start position:0% +commonly used slop value might be four +times the estimate of the deviation so + + align:start position:0% +times the estimate of the deviation so + + + align:start position:0% +times the estimate of the deviation so +the idea is that we want the slot value + + align:start position:0% +the idea is that we want the slot value + + + align:start position:0% +the idea is that we want the slot value +to be larger if this if the round trip + + align:start position:0% +to be larger if this if the round trip + + + align:start position:0% +to be larger if this if the round trip +time varies more if the roundtrip time + + align:start position:0% +time varies more if the roundtrip time + + + align:start position:0% +time varies more if the roundtrip time +is practically constant we don't want it + + align:start position:0% +is practically constant we don't want it + + + align:start position:0% +is practically constant we don't want it +to vary much we we we're sort of happy + + align:start position:0% +to vary much we we we're sort of happy + + + align:start position:0% +to vary much we we we're sort of happy +if we're um we don't want we we if the + + align:start position:0% +if we're um we don't want we we if the + + + align:start position:0% +if we're um we don't want we we if the +roundtrip time is is practically + + align:start position:0% +roundtrip time is is practically + + + align:start position:0% +roundtrip time is is practically +constant then we uh don't the timeout + + align:start position:0% +constant then we uh don't the timeout + + + align:start position:0% +constant then we uh don't the timeout +shouldn't be very much longer than that + + align:start position:0% +shouldn't be very much longer than that + + + align:start position:0% +shouldn't be very much longer than that +roundt trip time because that's going to + + align:start position:0% +roundt trip time because that's going to + + + align:start position:0% +roundt trip time because that's going to +suggest that we're going to be waiting + + align:start position:0% +suggest that we're going to be waiting + + + align:start position:0% +suggest that we're going to be waiting +longer than we need to to time out if + + align:start position:0% +longer than we need to to time out if + + + align:start position:0% +longer than we need to to time out if +the roundtrip time varies very + + align:start position:0% +the roundtrip time varies very + + + align:start position:0% +the roundtrip time varies very +dramatically we need to wait a + + align:start position:0% +dramatically we need to wait a + + + align:start position:0% +dramatically we need to wait a +relatively long time in order to be sure + + align:start position:0% +relatively long time in order to be sure + + + align:start position:0% +relatively long time in order to be sure +that the message uh in fact has has been + + align:start position:0% +that the message uh in fact has has been + + + align:start position:0% +that the message uh in fact has has been +lost as a oos to Simply uh taking a long + + align:start position:0% +lost as a oos to Simply uh taking a long + + + align:start position:0% +lost as a oos to Simply uh taking a long +time for the acknowledgement to get back + + align:start position:0% +time for the acknowledgement to get back + + + align:start position:0% +time for the acknowledgement to get back +to + + align:start position:0% + + + + align:start position:0% + +us okay so this is what we've seen so + + align:start position:0% +us okay so this is what we've seen so + + + align:start position:0% +us okay so this is what we've seen so +far now is we've seen how we can uh do + + align:start position:0% +far now is we've seen how we can uh do + + + align:start position:0% +far now is we've seen how we can uh do +build up this at at least once semantics + + align:start position:0% +build up this at at least once semantics + + + align:start position:0% +build up this at at least once semantics +using acknowledgements and we've talked + + align:start position:0% +using acknowledgements and we've talked + + + align:start position:0% +using acknowledgements and we've talked +about how we can go ahead and set these + + align:start position:0% +about how we can go ahead and set these + + + align:start position:0% +about how we can go ahead and set these +timers in order to uh allow us to + + align:start position:0% +timers in order to uh allow us to + + + align:start position:0% +timers in order to uh allow us to +calculate the roundtrip time for a + + align:start position:0% +calculate the roundtrip time for a + + + align:start position:0% +calculate the roundtrip time for a +message uh and these timers are going to + + align:start position:0% +message uh and these timers are going to + + + align:start position:0% +message uh and these timers are going to +allow us to sort of decide when we + + align:start position:0% +allow us to sort of decide when we + + + align:start position:0% +allow us to sort of decide when we +should ask when we should retransmit a + + align:start position:0% +should ask when we should retransmit a + + + align:start position:0% +should ask when we should retransmit a +message but we also saw how we have a + + align:start position:0% +message but we also saw how we have a + + + align:start position:0% +message but we also saw how we have a +little bit of a + + align:start position:0% +little bit of a + + + align:start position:0% +little bit of a +problem in the uh at least once protocol + + align:start position:0% +problem in the uh at least once protocol + + + align:start position:0% +problem in the uh at least once protocol +and the problem is that we can generate + + align:start position:0% +and the problem is that we can generate + + + align:start position:0% +and the problem is that we can generate +duplicates so in order to avoid + + align:start position:0% +duplicates so in order to avoid + + + align:start position:0% +duplicates so in order to avoid +duplicates we need to introduce this + + align:start position:0% +duplicates we need to introduce this + + + align:start position:0% +duplicates we need to introduce this +notion of atmost + + align:start position:0% + + + + align:start position:0% + +once okay so the idea with the at most + + align:start position:0% +once okay so the idea with the at most + + + align:start position:0% +once okay so the idea with the at most +wants is that we want to suppress + + align:start position:0% +wants is that we want to suppress + + + align:start position:0% +wants is that we want to suppress +duplicates + + align:start position:0% + + + + align:start position:0% + +and duplicate suppression it turns out + + align:start position:0% +and duplicate suppression it turns out + + + align:start position:0% +and duplicate suppression it turns out +it works a lot like the way that uh + + align:start position:0% +it works a lot like the way that uh + + + align:start position:0% +it works a lot like the way that uh +acknowledgements work on the on the + + align:start position:0% +acknowledgements work on the on the + + + align:start position:0% +acknowledgements work on the on the +receiver side uh or on the sender side + + align:start position:0% +receiver side uh or on the sender side + + + align:start position:0% +receiver side uh or on the sender side +so on the receiver side we're going to + + align:start position:0% +so on the receiver side we're going to + + + align:start position:0% +so on the receiver side we're going to +keep a table of all the of the nonces of + + align:start position:0% +keep a table of all the of the nonces of + + + align:start position:0% +keep a table of all the of the nonces of +all the messages that we've heard and + + align:start position:0% +all the messages that we've heard and + + + align:start position:0% +all the messages that we've heard and +we're only going to process a message + + align:start position:0% +we're only going to process a message + + + align:start position:0% +we're only going to process a message +when we receive when when we haven't + + align:start position:0% +when we receive when when we haven't + + + align:start position:0% +when we receive when when we haven't +already processed that message and we're + + align:start position:0% +already processed that message and we're + + + align:start position:0% +already processed that message and we're +going to tell whether we've already + + align:start position:0% +going to tell whether we've already + + + align:start position:0% +going to tell whether we've already +processed it by looking in this table of + + align:start position:0% +processed it by looking in this table of + + + align:start position:0% +processed it by looking in this table of +Anis so let's look at an example so here + + align:start position:0% +Anis so let's look at an example so here + + + align:start position:0% +Anis so let's look at an example so here +we are at this is sort of I'm showing + + align:start position:0% +we are at this is sort of I'm showing + + + align:start position:0% +we are at this is sort of I'm showing +you the protocol a stage in the uh at + + align:start position:0% +you the protocol a stage in the uh at + + + align:start position:0% +you the protocol a stage in the uh at +least once protocol that we were in + + align:start position:0% +least once protocol that we were in + + + align:start position:0% +least once protocol that we were in +before so we've already sent message one + + align:start position:0% +before so we've already sent message one + + + align:start position:0% +before so we've already sent message one +it's been successfully acknowledged um + + align:start position:0% +it's been successfully acknowledged um + + + align:start position:0% +it's been successfully acknowledged um +and you notice that we have this table + + align:start position:0% +and you notice that we have this table + + + align:start position:0% +and you notice that we have this table +of non's received messages that is at + + align:start position:0% +of non's received messages that is at + + + align:start position:0% +of non's received messages that is at +the receiver and in this table we have + + align:start position:0% +the receiver and in this table we have + + + align:start position:0% +the receiver and in this table we have +received uh this message with knot + + align:start position:0% +received uh this message with knot + + + align:start position:0% +received uh this message with knot +X Okay so now when the sender starts to + + align:start position:0% +X Okay so now when the sender starts to + + + align:start position:0% +X Okay so now when the sender starts to +decides to send message to with knots y + + align:start position:0% +decides to send message to with knots y + + + align:start position:0% +decides to send message to with knots y +it sends it out the message doesn't + + align:start position:0% +it sends it out the message doesn't + + + align:start position:0% +it sends it out the message doesn't +arrive uh we time out we + + align:start position:0% +arrive uh we time out we + + + align:start position:0% +arrive uh we time out we +retry um and this time the message is + + align:start position:0% +retry um and this time the message is + + + align:start position:0% +retry um and this time the message is +successfully received so what we do is + + align:start position:0% +successfully received so what we do is + + + align:start position:0% +successfully received so what we do is +we go ahead and add the nons for this + + align:start position:0% +we go ahead and add the nons for this + + + align:start position:0% +we go ahead and add the nons for this +message into the table on the + + align:start position:0% +message into the table on the + + + align:start position:0% +message into the table on the +receiver and then the receiver goes + + align:start position:0% +receiver and then the receiver goes + + + align:start position:0% +receiver and then the receiver goes +ahead and sends the acknowledgement but + + align:start position:0% +ahead and sends the acknowledgement but + + + align:start position:0% +ahead and sends the acknowledgement but +the acknowledgement is lost so again the + + align:start position:0% +the acknowledgement is lost so again the + + + align:start position:0% +the acknowledgement is lost so again the +sender times out sends the message and + + align:start position:0% +sender times out sends the message and + + + align:start position:0% +sender times out sends the message and +this time when the receiver receives + + align:start position:0% +this time when the receiver receives + + + align:start position:0% +this time when the receiver receives +this message it's going to look it up in + + align:start position:0% +this message it's going to look it up in + + + align:start position:0% +this message it's going to look it up in +the Reed messages table and it's going + + align:start position:0% +the Reed messages table and it's going + + + align:start position:0% +the Reed messages table and it's going +to see that this is a duplicate it + + align:start position:0% +to see that this is a duplicate it + + + align:start position:0% +to see that this is a duplicate it +already has seen a message with nony so + + align:start position:0% +already has seen a message with nony so + + + align:start position:0% +already has seen a message with nony so +it's not going to process this but it + + align:start position:0% +it's not going to process this but it + + + align:start position:0% +it's not going to process this but it +needs to still be sure that it sends the + + align:start position:0% +needs to still be sure that it sends the + + + align:start position:0% +needs to still be sure that it sends the +acknowledgement for the message so it + + align:start position:0% +acknowledgement for the message so it + + + align:start position:0% +acknowledgement for the message so it +doesn't actually do anything it doesn't + + align:start position:0% +doesn't actually do anything it doesn't + + + align:start position:0% +doesn't actually do anything it doesn't +actually process this message it doesn't + + align:start position:0% +actually process this message it doesn't + + + align:start position:0% +actually process this message it doesn't +pass it up to the application so the + + align:start position:0% +pass it up to the application so the + + + align:start position:0% +pass it up to the application so the +application can look at it but it still + + align:start position:0% +application can look at it but it still + + + align:start position:0% +application can look at it but it still +sends the acknowledgement so that the + + align:start position:0% +sends the acknowledgement so that the + + + align:start position:0% +sends the acknowledgement so that the +receiver knows that the message has been + + align:start position:0% +receiver knows that the message has been + + + align:start position:0% +receiver knows that the message has been +received okay + + align:start position:0% +received okay + + + align:start position:0% +received okay +so this is fine but if you think about + + align:start position:0% +so this is fine but if you think about + + + align:start position:0% +so this is fine but if you think about +this for a second this table of received + + align:start position:0% +this for a second this table of received + + + align:start position:0% +this for a second this table of received +messages is now just going to be kind of + + align:start position:0% +messages is now just going to be kind of + + + align:start position:0% +messages is now just going to be kind of +growing without bound right because + + align:start position:0% +growing without bound right because + + + align:start position:0% +growing without bound right because +every time we receive a message we're + + align:start position:0% +every time we receive a message we're + + + align:start position:0% +every time we receive a message we're +going to add a new message to this table + + align:start position:0% +going to add a new message to this table + + + align:start position:0% +going to add a new message to this table +of nonas right and this is a problem I + + align:start position:0% +of nonas right and this is a problem I + + + align:start position:0% +of nonas right and this is a problem I +mean if we're sending you know thousands + + align:start position:0% +mean if we're sending you know thousands + + + align:start position:0% +mean if we're sending you know thousands +of messages out over the out over the + + align:start position:0% +of messages out over the out over the + + + align:start position:0% +of messages out over the out over the +network then this table is going to + + align:start position:0% +network then this table is going to + + + align:start position:0% +network then this table is going to +become very very + + align:start position:0% +become very very + + + align:start position:0% +become very very +large so what are we going to do about + + align:start position:0% +large so what are we going to do about + + + align:start position:0% +large so what are we going to do about +it well uh we're going to do sort of + + align:start position:0% +it well uh we're going to do sort of + + + align:start position:0% +it well uh we're going to do sort of +again uh the obvious thing we're going + + align:start position:0% +again uh the obvious thing we're going + + + align:start position:0% +again uh the obvious thing we're going +to have the the sender send some + + align:start position:0% +to have the the sender send some + + + align:start position:0% +to have the the sender send some +additional information that lets the + + align:start position:0% +additional information that lets the + + + align:start position:0% +additional information that lets the +receiver know when the receiver when + + align:start position:0% +receiver know when the receiver when + + + align:start position:0% +receiver know when the receiver when +which messages the receiver has actually + + align:start position:0% +which messages the receiver has actually + + + align:start position:0% +which messages the receiver has actually +heard so a common way that this might be + + align:start position:0% +heard so a common way that this might be + + + align:start position:0% +heard so a common way that this might be +done is to Simply along with each + + align:start position:0% +done is to Simply along with each + + + align:start position:0% +done is to Simply along with each +message that gets sent piggy back a + + align:start position:0% +message that gets sent piggy back a + + + align:start position:0% +message that gets sent piggy back a +little bit of information for example + + align:start position:0% +little bit of information for example + + + align:start position:0% +little bit of information for example +that contains the list of messages that + + align:start position:0% +that contains the list of messages that + + + align:start position:0% +that contains the list of messages that +the uh sender knows that the receiver + + align:start position:0% +the uh sender knows that the receiver + + + align:start position:0% +the uh sender knows that the receiver +has actually received right so when a + + align:start position:0% +has actually received right so when a + + + align:start position:0% +has actually received right so when a +sender receives an acknowledgement for a + + align:start position:0% +sender receives an acknowledgement for a + + + align:start position:0% +sender receives an acknowledgement for a +message um it knows that it's never + + align:start position:0% +message um it knows that it's never + + + align:start position:0% +message um it knows that it's never +going to have to request that the uh + + align:start position:0% +going to have to request that the uh + + + align:start position:0% +going to have to request that the uh +it's never going to resend that message + + align:start position:0% +it's never going to resend that message + + + align:start position:0% +it's never going to resend that message +anymore and so there's no reason for the + + align:start position:0% +anymore and so there's no reason for the + + + align:start position:0% +anymore and so there's no reason for the +receiver to keep that message in its + + align:start position:0% +receiver to keep that message in its + + + align:start position:0% +receiver to keep that message in its +table of received messages because it's + + align:start position:0% +table of received messages because it's + + + align:start position:0% +table of received messages because it's +never going to be asked to acknowledge + + align:start position:0% +never going to be asked to acknowledge + + + align:start position:0% +never going to be asked to acknowledge +that message again so we can attach a + + align:start position:0% +that message again so we can attach a + + + align:start position:0% +that message again so we can attach a +little bit of information to the + + align:start position:0% +little bit of information to the + + + align:start position:0% +little bit of information to the +messages that we send that indicates + + align:start position:0% +messages that we send that indicates + + + align:start position:0% +messages that we send that indicates +sort of which messages we' have + + align:start position:0% +sort of which messages we' have + + + align:start position:0% +sort of which messages we' have +definitely we've completed up to this + + align:start position:0% +definitely we've completed up to this + + + align:start position:0% +definitely we've completed up to this +point + + align:start position:0% + + + + align:start position:0% + +okay um so this is a simple way in which + + align:start position:0% +okay um so this is a simple way in which + + + align:start position:0% +okay um so this is a simple way in which +we can sort of eliminate these uh + + align:start position:0% +we can sort of eliminate these uh + + + align:start position:0% +we can sort of eliminate these uh +messages that are hanging around um + + align:start position:0% +messages that are hanging around um + + + align:start position:0% +messages that are hanging around um +these messages that are sort of left in + + align:start position:0% +these messages that are sort of left in + + + align:start position:0% +these messages that are sort of left in +the uh in our table of uh received + + align:start position:0% +the uh in our table of uh received + + + align:start position:0% +the uh in our table of uh received +messages are sometimes referred to as + + align:start position:0% +messages are sometimes referred to as + + + align:start position:0% +messages are sometimes referred to as +tombstones which is kind of a funny name + + align:start position:0% +tombstones which is kind of a funny name + + + align:start position:0% +tombstones which is kind of a funny name +but uh the idea is that there these + + align:start position:0% +but uh the idea is that there these + + + align:start position:0% +but uh the idea is that there these +messages that are kind of hanging the + + align:start position:0% +messages that are kind of hanging the + + + align:start position:0% +messages that are kind of hanging the +they're these the sort of remnants of a + + align:start position:0% +they're these the sort of remnants of a + + + align:start position:0% +they're these the sort of remnants of a +dead message that's hanging around that + + align:start position:0% +dead message that's hanging around that + + + align:start position:0% +dead message that's hanging around that +we're never going to need to process + + align:start position:0% +we're never going to need to process + + + align:start position:0% +we're never going to need to process +again but uh it might just be sitting in + + align:start position:0% +again but uh it might just be sitting in + + + align:start position:0% +again but uh it might just be sitting in +this table and we're able to get rid of + + align:start position:0% +this table and we're able to get rid of + + + align:start position:0% +this table and we're able to get rid of +some of the tombstones by piggybacking + + align:start position:0% +some of the tombstones by piggybacking + + + align:start position:0% +some of the tombstones by piggybacking +this information onto the ends of the + + align:start position:0% +this information onto the ends of the + + + align:start position:0% +this information onto the ends of the +messages that we retransmit but uh you + + align:start position:0% +messages that we retransmit but uh you + + + align:start position:0% +messages that we retransmit but uh you +have to you have to realize that there's + + align:start position:0% +have to you have to realize that there's + + + align:start position:0% +have to you have to realize that there's +always going to be a few messages left + + align:start position:0% +always going to be a few messages left + + + align:start position:0% +always going to be a few messages left +over in this received messages table + + align:start position:0% +over in this received messages table + + + align:start position:0% +over in this received messages table +because if we use this piggybacking + + align:start position:0% +because if we use this piggybacking + + + align:start position:0% +because if we use this piggybacking +technique because we're piggybacking + + align:start position:0% +technique because we're piggybacking + + + align:start position:0% +technique because we're piggybacking +messages uh piggybacking the list of + + align:start position:0% +messages uh piggybacking the list of + + + align:start position:0% +messages uh piggybacking the list of +done messages uh onto messages that are + + align:start position:0% +done messages uh onto messages that are + + + align:start position:0% +done messages uh onto messages that are +sent so if me if the sender never sends + + align:start position:0% +sent so if me if the sender never sends + + + align:start position:0% +sent so if me if the sender never sends +any more messages then the receiver is + + align:start position:0% +any more messages then the receiver is + + + align:start position:0% +any more messages then the receiver is +never going to be able to eliminate any + + align:start position:0% +never going to be able to eliminate any + + + align:start position:0% +never going to be able to eliminate any +of the Tombstones from its list of + + align:start position:0% +of the Tombstones from its list of + + + align:start position:0% +of the Tombstones from its list of +received messages + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so now what we've seen is a simple way + + align:start position:0% +so now what we've seen is a simple way + + + align:start position:0% +so now what we've seen is a simple way +to provide this sort of notion of at + + align:start position:0% +to provide this sort of notion of at + + + align:start position:0% +to provide this sort of notion of at +least once and at most once delivery um + + align:start position:0% +least once and at most once delivery um + + + align:start position:0% +least once and at most once delivery um +and so as I said before taken together + + align:start position:0% +and so as I said before taken together + + + align:start position:0% +and so as I said before taken together +this is of is sometimes called exactly + + align:start position:0% +this is of is sometimes called exactly + + + align:start position:0% +this is of is sometimes called exactly +once an exactly once protocol um and + + align:start position:0% +once an exactly once protocol um and + + + align:start position:0% +once an exactly once protocol um and +this variant of this protocol that we've + + align:start position:0% +this variant of this protocol that we've + + + align:start position:0% +this variant of this protocol that we've +seen uh is is called a lock step + + align:start position:0% +seen uh is is called a lock step + + + align:start position:0% +seen uh is is called a lock step +protocol + + align:start position:0% +protocol + + + align:start position:0% +protocol +okay so it's called lock step + + align:start position:0% + + + + align:start position:0% + +because the sender and receiver are + + align:start position:0% +because the sender and receiver are + + + align:start position:0% +because the sender and receiver are +operating in lockstep the sender is the + + align:start position:0% +operating in lockstep the sender is the + + + align:start position:0% +operating in lockstep the sender is the +receiver sends a message and then it + + align:start position:0% +receiver sends a message and then it + + + align:start position:0% +receiver sends a message and then it +waits for the the sender sends a message + + align:start position:0% +waits for the the sender sends a message + + + align:start position:0% +waits for the the sender sends a message +and then it waits for the receiver to + + align:start position:0% +and then it waits for the receiver to + + + align:start position:0% +and then it waits for the receiver to +send an acknowledgement before it sends + + align:start position:0% +send an acknowledgement before it sends + + + align:start position:0% +send an acknowledgement before it sends +any additional messages right so we're + + align:start position:0% +any additional messages right so we're + + + align:start position:0% +any additional messages right so we're +always sort of sitting here uh waiting + + align:start position:0% +always sort of sitting here uh waiting + + + align:start position:0% +always sort of sitting here uh waiting +for the the the sender is sort of + + align:start position:0% +for the the the sender is sort of + + + align:start position:0% +for the the the sender is sort of +basically spending a lot of time idle + + align:start position:0% +basically spending a lot of time idle + + + align:start position:0% +basically spending a lot of time idle +waiting to receive an acknowledgement + + align:start position:0% +waiting to receive an acknowledgement + + + align:start position:0% +waiting to receive an acknowledgement +and if you think about what this + + align:start position:0% +and if you think about what this + + + align:start position:0% +and if you think about what this +means in terms of + + align:start position:0% + + + + align:start position:0% + +the in terms of the throughput of the + + align:start position:0% +the in terms of the throughput of the + + + align:start position:0% +the in terms of the throughput of the +network it's kind of a limitation so + + align:start position:0% +network it's kind of a limitation so + + + align:start position:0% +network it's kind of a limitation so +let's do a simple + + align:start position:0% + + + + align:start position:0% + +calculation so suppose that we said that + + align:start position:0% +calculation so suppose that we said that + + + align:start position:0% +calculation so suppose that we said that +uh packets that the the segments that + + align:start position:0% +uh packets that the the segments that + + + align:start position:0% +uh packets that the the segments that +are being sent in this network that are + + align:start position:0% +are being sent in this network that are + + + align:start position:0% +are being sent in this network that are +being these things that are being sent + + align:start position:0% +being these things that are being sent + + + align:start position:0% +being these things that are being sent +back and forth and being acknowledged + + align:start position:0% +back and forth and being acknowledged + + + align:start position:0% +back and forth and being acknowledged +are say 512 bytes large + + align:start position:0% + + + + align:start position:0% + +and suppose we said that it takes the + + align:start position:0% +and suppose we said that it takes the + + + align:start position:0% +and suppose we said that it takes the +roundtrip time in the network is say 100 + + align:start position:0% +roundtrip time in the network is say 100 + + + align:start position:0% +roundtrip time in the network is say 100 +milliseconds which might be a common + + align:start position:0% +milliseconds which might be a common + + + align:start position:0% +milliseconds which might be a common +roundtrip time uh in a traditional + + align:start position:0% +roundtrip time uh in a traditional + + + align:start position:0% +roundtrip time uh in a traditional +Network well the throughput of this + + align:start position:0% +Network well the throughput of this + + + align:start position:0% +Network well the throughput of this +network is going to be the maximum + + align:start position:0% +network is going to be the maximum + + + align:start position:0% +network is going to be the maximum +throughput of this network is going to + + align:start position:0% +throughput of this network is going to + + + align:start position:0% +throughput of this network is going to +be limited by this number 512 bytes + + align:start position:0% +be limited by this number 512 bytes + + + align:start position:0% +be limited by this number 512 bytes +divided by 100 milliseconds right the + + align:start position:0% +divided by 100 milliseconds right the + + + align:start position:0% +divided by 100 milliseconds right the +roundt trip time is 100 milliseconds um + + align:start position:0% +roundt trip time is 100 milliseconds um + + + align:start position:0% +roundt trip time is 100 milliseconds um +and so we have to wait 100 milliseconds + + align:start position:0% +and so we have to wait 100 milliseconds + + + align:start position:0% +and so we have to wait 100 milliseconds +between each transmission of messages + + align:start position:0% +between each transmission of messages + + + align:start position:0% +between each transmission of messages +and the sort of size of a message is uh + + align:start position:0% +and the sort of size of a message is uh + + + align:start position:0% +and the sort of size of a message is uh +if the size of a message is 512 bytes + + align:start position:0% +if the size of a message is 512 bytes + + + align:start position:0% +if the size of a message is 512 bytes +then we're going to be able to send 10 + + align:start position:0% +then we're going to be able to send 10 + + + align:start position:0% +then we're going to be able to send 10 +of these messages per second so we're + + align:start position:0% +of these messages per second so we're + + + align:start position:0% +of these messages per second so we're +going to send sort of uh approximately + + align:start position:0% +going to send sort of uh approximately + + + align:start position:0% +going to send sort of uh approximately +50 kilobits per + + align:start position:0% +50 kilobits per + + + align:start position:0% +50 kilobits per +second okay that's not very fast right + + align:start position:0% +second okay that's not very fast right + + + align:start position:0% +second okay that's not very fast right +if we want to send you know to modern + + align:start position:0% +if we want to send you know to modern + + + align:start position:0% +if we want to send you know to modern +modern networks are often capable of + + align:start position:0% +modern networks are often capable of + + + align:start position:0% +modern networks are often capable of +sending uh you know tens or hundreds of + + align:start position:0% +sending uh you know tens or hundreds of + + + align:start position:0% +sending uh you know tens or hundreds of +megabytes a second so megabits a second + + align:start position:0% +megabytes a second so megabits a second + + + align:start position:0% +megabytes a second so megabits a second +so we would like to be able to make this + + align:start position:0% +so we would like to be able to make this + + + align:start position:0% +so we would like to be able to make this +number higher + + align:start position:0% +number higher + + + align:start position:0% +number higher +um so this is a this is a bit of a + + align:start position:0% +um so this is a this is a bit of a + + + align:start position:0% +um so this is a this is a bit of a +performance + + align:start position:0% + + + + align:start position:0% + +problem and the way we're going to do + + align:start position:0% +problem and the way we're going to do + + + align:start position:0% +problem and the way we're going to do +this is by making it so that the rece + + align:start position:0% +this is by making it so that the rece + + + align:start position:0% +this is by making it so that the rece +the sender doesn't wait uh to receive + + align:start position:0% +the sender doesn't wait uh to receive + + + align:start position:0% +the sender doesn't wait uh to receive +its acknowledgements before it goes and + + align:start position:0% +its acknowledgements before it goes and + + + align:start position:0% +its acknowledgements before it goes and +sends the next message so the sender is + + align:start position:0% +sends the next message so the sender is + + + align:start position:0% +sends the next message so the sender is +going to start sending the next message + + align:start position:0% +going to start sending the next message + + + align:start position:0% +going to start sending the next message +before it's even heard the first message + + align:start position:0% +before it's even heard the first message + + + align:start position:0% +before it's even heard the first message +being acknowledged so we're going to + + align:start position:0% +being acknowledged so we're going to + + + align:start position:0% +being acknowledged so we're going to +have + + align:start position:0% + + + + align:start position:0% + +multiple overlapping + + align:start position:0% + + + + align:start position:0% + +Transmissions + + align:start position:0% +Transmissions + + + align:start position:0% +Transmissions +okay so let's see a really simple + + align:start position:0% +okay so let's see a really simple + + + align:start position:0% +okay so let's see a really simple +example of how this + + align:start position:0% +example of how this + + + align:start position:0% +example of how this +works so the idea is now that the sender + + align:start position:0% +works so the idea is now that the sender + + + align:start position:0% +works so the idea is now that the sender +is it's going to send a message and then + + align:start position:0% +is it's going to send a message and then + + + align:start position:0% +is it's going to send a message and then +before the receiver before it's even + + align:start position:0% +before the receiver before it's even + + + align:start position:0% +before the receiver before it's even +heard the acknowledgement from the + + align:start position:0% +heard the acknowledgement from the + + + align:start position:0% +heard the acknowledgement from the +receiver it's going to go ahead and + + align:start position:0% +receiver it's going to go ahead and + + + align:start position:0% +receiver it's going to go ahead and +start sending the message at the same + + align:start position:0% +start sending the message at the same + + + align:start position:0% +start sending the message at the same +time the receiver can go ahead and + + align:start position:0% +time the receiver can go ahead and + + + align:start position:0% +time the receiver can go ahead and +acknowledge the messages that have + + align:start position:0% +acknowledge the messages that have + + + align:start position:0% +acknowledge the messages that have +already been sent so you sort of see + + align:start position:0% +already been sent so you sort of see + + + align:start position:0% +already been sent so you sort of see +what's happening here is that as time + + align:start position:0% +what's happening here is that as time + + + align:start position:0% +what's happening here is that as time +passes the additional messages are being + + align:start position:0% +passes the additional messages are being + + + align:start position:0% +passes the additional messages are being +sent and the acknowledgement for those + + align:start position:0% +sent and the acknowledgement for those + + + align:start position:0% +sent and the acknowledgement for those +messages start getting being sent as + + align:start position:0% +messages start getting being sent as + + + align:start position:0% +messages start getting being sent as +soon as possible so we have a whole + + align:start position:0% +soon as possible so we have a whole + + + align:start position:0% +soon as possible so we have a whole +bunch of messages that are kind of + + align:start position:0% +bunch of messages that are kind of + + + align:start position:0% +bunch of messages that are kind of +flying back and forth within this + + align:start position:0% +flying back and forth within this + + + align:start position:0% +flying back and forth within this +network um and these I've only shown the + + align:start position:0% +network um and these I've only shown the + + + align:start position:0% +network um and these I've only shown the +sort of yellow red and blue messages + + align:start position:0% +sort of yellow red and blue messages + + + align:start position:0% +sort of yellow red and blue messages +actually being acknowledged here the + + align:start position:0% +actually being acknowledged here the + + + align:start position:0% +actually being acknowledged here the +white messages aren't being acknowledged + + align:start position:0% +white messages aren't being acknowledged + + + align:start position:0% +white messages aren't being acknowledged +but of course there would be + + align:start position:0% +but of course there would be + + + align:start position:0% +but of course there would be +acknowledgements flowing for those as + + align:start position:0% +acknowledgements flowing for those as + + + align:start position:0% +acknowledgements flowing for those as +well um so this is this seems really + + align:start position:0% +well um so this is this seems really + + + align:start position:0% +well um so this is this seems really +good right now we can send messages + + align:start position:0% +good right now we can send messages + + + align:start position:0% +good right now we can send messages +basically as fast as we can cram them + + align:start position:0% +basically as fast as we can cram them + + + align:start position:0% +basically as fast as we can cram them +onto the network work um and we sort of + + align:start position:0% +onto the network work um and we sort of + + + align:start position:0% +onto the network work um and we sort of +don't have to wait for the + + align:start position:0% +don't have to wait for the + + + align:start position:0% +don't have to wait for the +acknowledgements to come back + + align:start position:0% +acknowledgements to come back + + + align:start position:0% +acknowledgements to come back +anymore um so in in effect what we've + + align:start position:0% +anymore um so in in effect what we've + + + align:start position:0% +anymore um so in in effect what we've +said is now the throughput is simply + + align:start position:0% +said is now the throughput is simply + + + align:start position:0% +said is now the throughput is simply +constrained by how fast we can cram the + + align:start position:0% +constrained by how fast we can cram the + + + align:start position:0% +constrained by how fast we can cram the +bites onto the + + align:start position:0% +bites onto the + + + align:start position:0% +bites onto the +network but this is a little bit of an + + align:start position:0% +network but this is a little bit of an + + + align:start position:0% +network but this is a little bit of an +oversimplification right because this is + + align:start position:0% +oversimplification right because this is + + + align:start position:0% +oversimplification right because this is +sort of uh + + align:start position:0% +sort of uh + + + align:start position:0% +sort of uh +ignoring what it is that the receiver + + align:start position:0% +ignoring what it is that the receiver + + + align:start position:0% +ignoring what it is that the receiver +suppose the sender is just sending data + + align:start position:0% +suppose the sender is just sending data + + + align:start position:0% +suppose the sender is just sending data +as fast as it can well the receiver has + + align:start position:0% +as fast as it can well the receiver has + + + align:start position:0% +as fast as it can well the receiver has +to receive that data has to do something + + align:start position:0% +to receive that data has to do something + + + align:start position:0% +to receive that data has to do something +with it it has to process it has to take + + align:start position:0% +with it it has to process it has to take + + + align:start position:0% +with it it has to process it has to take +some action on it right and so it's very + + align:start position:0% +some action on it right and so it's very + + + align:start position:0% +some action on it right and so it's very +possible or very likely in fact that uh + + align:start position:0% +possible or very likely in fact that uh + + + align:start position:0% +possible or very likely in fact that uh +if we send if we if we cram data at the + + align:start position:0% +if we send if we if we cram data at the + + + align:start position:0% +if we send if we if we cram data at the +receiver in this way that the receiver + + align:start position:0% +receiver in this way that the receiver + + + align:start position:0% +receiver in this way that the receiver +is going to become overloaded right the + + align:start position:0% +is going to become overloaded right the + + + align:start position:0% +is going to become overloaded right the +receiver has some limited SI limited + + align:start position:0% +receiver has some limited SI limited + + + align:start position:0% +receiver has some limited SI limited +amount of data that it can buffer or + + align:start position:0% +amount of data that it can buffer or + + + align:start position:0% +amount of data that it can buffer or +that it can hold on to um and it's going + + align:start position:0% +that it can hold on to um and it's going + + + align:start position:0% +that it can hold on to um and it's going +to you're going we're going to overflow + + align:start position:0% +to you're going we're going to overflow + + + align:start position:0% +to you're going we're going to overflow +those buffers and we're going to create + + align:start position:0% +those buffers and we're going to create + + + align:start position:0% +those buffers and we're going to create +a problem so what we want to do is to + + align:start position:0% +a problem so what we want to do is to + + + align:start position:0% +a problem so what we want to do is to +have some way to allow the receiver to + + align:start position:0% +have some way to allow the receiver to + + + align:start position:0% +have some way to allow the receiver to +kind of throttle the transmission of the + + align:start position:0% +kind of throttle the transmission of the + + + align:start position:0% +kind of throttle the transmission of the +sender to ask the sender to back off a + + align:start position:0% +sender to ask the sender to back off a + + + align:start position:0% +sender to ask the sender to back off a +little bit and not send so + + align:start position:0% + + + + align:start position:0% + +aggressively okay so we call + + align:start position:0% + + + + align:start position:0% + +this the the technique that we're going + + align:start position:0% +this the the technique that we're going + + + align:start position:0% +this the the technique that we're going +to use is called flow control and it's + + align:start position:0% +to use is called flow control and it's + + + align:start position:0% +to use is called flow control and it's +basically just a way in which the + + align:start position:0% +basically just a way in which the + + + align:start position:0% +basically just a way in which the +receiver can tell the sender what rate + + align:start position:0% +receiver can tell the sender what rate + + + align:start position:0% +receiver can tell the sender what rate +it would like to receive data + + align:start position:0% + + + + align:start position:0% + +at okay so this is going to be sort of + + align:start position:0% +at okay so this is going to be sort of + + + align:start position:0% +at okay so this is going to be sort of +receiver driven + + align:start position:0% + + + + align:start position:0% + +feedback um and we're going to look + + align:start position:0% +feedback um and we're going to look + + + align:start position:0% +feedback um and we're going to look +at two techniques basically for doing + + align:start position:0% +at two techniques basically for doing + + + align:start position:0% +at two techniques basically for doing +this the first one is a technique called + + align:start position:0% +this the first one is a technique called + + + align:start position:0% +this the first one is a technique called +fixed + + align:start position:0% +fixed + + + align:start position:0% +fixed +windows and + + align:start position:0% + + + + align:start position:0% + +the other technique is a technique + + align:start position:0% +the other technique is a technique + + + align:start position:0% +the other technique is a technique +called sliding + + align:start position:0% + + + + align:start position:0% + +Windows okay and what we mean by wind + + align:start position:0% +Windows okay and what we mean by wind + + + align:start position:0% +Windows okay and what we mean by wind +here this is simply a window is simply a + + align:start position:0% +here this is simply a window is simply a + + + align:start position:0% +here this is simply a window is simply a +the the the size of the data that the + + align:start position:0% +the the the size of the data that the + + + align:start position:0% +the the the size of the data that the +receiver uh can accept the amount the + + align:start position:0% +receiver uh can accept the amount the + + + align:start position:0% +receiver uh can accept the amount the +number of messages that the receiver can + + align:start position:0% +number of messages that the receiver can + + + align:start position:0% +number of messages that the receiver can +accept so this + + align:start position:0% + + + + align:start position:0% + +is can accept at one time + + align:start position:0% + + + + align:start position:0% + +so the idea is we're going to send a + + align:start position:0% +so the idea is we're going to send a + + + align:start position:0% +so the idea is we're going to send a +Windows worth of data uh all + + align:start position:0% +Windows worth of data uh all + + + align:start position:0% +Windows worth of data uh all +continuously and then once the receiver + + align:start position:0% +continuously and then once the receiver + + + align:start position:0% +continuously and then once the receiver +says that it's done processing that + + align:start position:0% +says that it's done processing that + + + align:start position:0% +says that it's done processing that +window we're going to be able to go + + align:start position:0% +window we're going to be able to go + + + align:start position:0% +window we're going to be able to go +ahead and uh send uh send send a next + + align:start position:0% +ahead and uh send uh send send a next + + + align:start position:0% +ahead and uh send uh send send a next +window to it so this first scheme that + + align:start position:0% +window to it so this first scheme that + + + align:start position:0% +window to it so this first scheme that +we're going to look at um is called + + align:start position:0% +we're going to look at um is called + + + align:start position:0% +we're going to look at um is called +fixed is called the fixed wind is called + + align:start position:0% +fixed is called the fixed wind is called + + + align:start position:0% +fixed is called the fixed wind is called +the fixed window scheme um and the idea + + align:start position:0% +the fixed window scheme um and the idea + + + align:start position:0% +the fixed window scheme um and the idea +is really very straightforward the + + align:start position:0% +is really very straightforward the + + + align:start position:0% +is really very straightforward the +sender and the receiver at the beginning + + align:start position:0% +sender and the receiver at the beginning + + + align:start position:0% +sender and the receiver at the beginning +of communication are going to negotiate + + align:start position:0% +of communication are going to negotiate + + + align:start position:0% +of communication are going to negotiate +they're going to exchange some + + align:start position:0% +they're going to exchange some + + + align:start position:0% +they're going to exchange some +information about what the window size + + align:start position:0% +information about what the window size + + + align:start position:0% +information about what the window size +is so the receiver is gonna so the + + align:start position:0% +is so the receiver is gonna so the + + + align:start position:0% +is so the receiver is gonna so the +sender is going to request the + + align:start position:0% +sender is going to request the + + + align:start position:0% +sender is going to request the +connection be opened and then the + + align:start position:0% +connection be opened and then the + + + align:start position:0% +connection be opened and then the +receiver is going to say for example + + align:start position:0% +receiver is going to say for example + + + align:start position:0% +receiver is going to say for example +okay uh I'm let's go ahead and start + + align:start position:0% +okay uh I'm let's go ahead and start + + + align:start position:0% +okay uh I'm let's go ahead and start +having this conversation and by the way + + align:start position:0% +having this conversation and by the way + + + align:start position:0% +having this conversation and by the way +my window size is four + + align:start position:0% +my window size is four + + + align:start position:0% +my window size is four +segments so now the sender can send four + + align:start position:0% +segments so now the sender can send four + + + align:start position:0% +segments so now the sender can send four +segments all at once and the receiver + + align:start position:0% +segments all at once and the receiver + + + align:start position:0% +segments all at once and the receiver +can go ahead and acknowledge them so we + + align:start position:0% +can go ahead and acknowledge them so we + + + align:start position:0% +can go ahead and acknowledge them so we +can have four segments that are sort of + + align:start position:0% +can have four segments that are sort of + + + align:start position:0% +can have four segments that are sort of +uh inflight at any one time and then + + align:start position:0% +uh inflight at any one time and then + + + align:start position:0% +uh inflight at any one time and then +after those messages have all been + + align:start position:0% +after those messages have all been + + + align:start position:0% +after those messages have all been +acknowledged um + + align:start position:0% +acknowledged um + + + align:start position:0% +acknowledged um +the receiver is going to have to sort of + + align:start position:0% +the receiver is going to have to sort of + + + align:start position:0% +the receiver is going to have to sort of +chew on those messages and process them + + align:start position:0% +chew on those messages and process them + + + align:start position:0% +chew on those messages and process them +for a little + + align:start position:0% +for a little + + + align:start position:0% +for a little +while after which during which time + + align:start position:0% +while after which during which time + + + align:start position:0% +while after which during which time +basically the sender is simply waiting + + align:start position:0% +basically the sender is simply waiting + + + align:start position:0% +basically the sender is simply waiting +it's simply sitting there waiting but + + align:start position:0% +it's simply sitting there waiting but + + + align:start position:0% +it's simply sitting there waiting but +notice that we were at least able to uh + + align:start position:0% +notice that we were at least able to uh + + + align:start position:0% +notice that we were at least able to uh +the sender was able to do a little bit + + align:start position:0% +the sender was able to do a little bit + + + align:start position:0% +the sender was able to do a little bit +of extra work it was able to send all + + align:start position:0% +of extra work it was able to send all + + + align:start position:0% +of extra work it was able to send all +four of these messages + + align:start position:0% +four of these messages + + + align:start position:0% +four of these messages +simultaneously and then when this + + align:start position:0% +simultaneously and then when this + + + align:start position:0% +simultaneously and then when this +receiver has finished processing these + + align:start position:0% +receiver has finished processing these + + + align:start position:0% +receiver has finished processing these +messages it's going to go ahead and uh + + align:start position:0% +messages it's going to go ahead and uh + + + align:start position:0% +messages it's going to go ahead and uh +ask for some additional set of messages + + align:start position:0% +ask for some additional set of messages + + + align:start position:0% +ask for some additional set of messages +to be transmitted out over the Network + + align:start position:0% +to be transmitted out over the Network + + + align:start position:0% +to be transmitted out over the Network +so notice that there's uh a s a little + + align:start position:0% +so notice that there's uh a s a little + + + align:start position:0% +so notice that there's uh a s a little +assumption here which is that + + align:start position:0% +assumption here which is that + + + align:start position:0% +assumption here which is that +acknowledgements uh are being sent + + align:start position:0% +acknowledgements uh are being sent + + + align:start position:0% +acknowledgements uh are being sent +before the sort of receiver has actually + + align:start position:0% +before the sort of receiver has actually + + + align:start position:0% +before the sort of receiver has actually +finished processing the messages so that + + align:start position:0% +finished processing the messages so that + + + align:start position:0% +finished processing the messages so that +we're it's sort of what the protocol + + align:start position:0% +we're it's sort of what the protocol + + + align:start position:0% +we're it's sort of what the protocol +that I'm showing here is that the + + align:start position:0% +that I'm showing here is that the + + + align:start position:0% +that I'm showing here is that the +receiver receives a message and it + + align:start position:0% +receiver receives a message and it + + + align:start position:0% +receiver receives a message and it +immediately acknowledges it uh without + + align:start position:0% +immediately acknowledges it uh without + + + align:start position:0% +immediately acknowledges it uh without +even though it hasn't actually the + + align:start position:0% +even though it hasn't actually the + + + align:start position:0% +even though it hasn't actually the +application hasn't necessarily processed + + align:start position:0% +application hasn't necessarily processed + + + align:start position:0% +application hasn't necessarily processed +this message yet the reason we want to + + align:start position:0% +this message yet the reason we want to + + + align:start position:0% +this message yet the reason we want to +do this is that application process + + align:start position:0% +do this is that application process + + + align:start position:0% +do this is that application process +remember we're it's already hard enough + + align:start position:0% +remember we're it's already hard enough + + + align:start position:0% +remember we're it's already hard enough +for us to estimate this roundtrip time + + align:start position:0% +for us to estimate this roundtrip time + + + align:start position:0% +for us to estimate this roundtrip time +using this estimated this this ewma uh + + align:start position:0% +using this estimated this this ewma uh + + + align:start position:0% +using this estimated this this ewma uh +approach and so trying to sort of also + + align:start position:0% +approach and so trying to sort of also + + + align:start position:0% +approach and so trying to sort of also +estimate how long it would take the + + align:start position:0% +estimate how long it would take the + + + align:start position:0% +estimate how long it would take the +application to process the data would + + align:start position:0% +application to process the data would + + + align:start position:0% +application to process the data would +further complicate this process of + + align:start position:0% +further complicate this process of + + + align:start position:0% +further complicate this process of +setting timers so we usually just send + + align:start position:0% +setting timers so we usually just send + + + align:start position:0% +setting timers so we usually just send +acknowledgements right + + align:start position:0% +acknowledgements right + + + align:start position:0% +acknowledgements right +away okay so this is the fix size window + + align:start position:0% +away okay so this is the fix size window + + + align:start position:0% +away okay so this is the fix size window +scheme and it's nice because now uh + + align:start position:0% +scheme and it's nice because now uh + + + align:start position:0% +scheme and it's nice because now uh +basically we've set this thing up so + + align:start position:0% +basically we've set this thing up so + + + align:start position:0% +basically we've set this thing up so +that uh the the sender can send more me + + align:start position:0% +that uh the the sender can send more me + + + align:start position:0% +that uh the the sender can send more me +can can sort of send more messages + + align:start position:0% +can can sort of send more messages + + + align:start position:0% +can can sort of send more messages +without waiting for the acknowledgements + + align:start position:0% +without waiting for the acknowledgements + + + align:start position:0% +without waiting for the acknowledgements +but the receiver has a way that it can + + align:start position:0% +but the receiver has a way that it can + + + align:start position:0% +but the receiver has a way that it can +kind of throttle how fast the sender + + align:start position:0% +kind of throttle how fast the sender + + + align:start position:0% +kind of throttle how fast the sender +sends it knows that it only has buffers + + align:start position:0% +sends it knows that it only has buffers + + + align:start position:0% +sends it knows that it only has buffers +for four messages so it says my window + + align:start position:0% +for four messages so it says my window + + + align:start position:0% +for four messages so it says my window +size is + + align:start position:0% +size is + + + align:start position:0% +size is +four but we would like to do a little + + align:start position:0% +four but we would like to do a little + + + align:start position:0% +four but we would like to do a little +bit better right in particular we would + + align:start position:0% +bit better right in particular we would + + + align:start position:0% +bit better right in particular we would +like to avoid this sort of situation + + align:start position:0% +like to avoid this sort of situation + + + align:start position:0% +like to avoid this sort of situation +where uh the sender both so so in this + + align:start position:0% +where uh the sender both so so in this + + + align:start position:0% +where uh the sender both so so in this +case we sort of have long periods where + + align:start position:0% +case we sort of have long periods where + + + align:start position:0% +case we sort of have long periods where +the network is kind of sitting idle + + align:start position:0% +the network is kind of sitting idle + + + align:start position:0% +the network is kind of sitting idle +where we're not using available + + align:start position:0% +where we're not using available + + + align:start position:0% +where we're not using available +bandwidth within the network um because + + align:start position:0% +bandwidth within the network um because + + + align:start position:0% +bandwidth within the network um because +we're sort of waiting the the the sender + + align:start position:0% +we're sort of waiting the the the sender + + + align:start position:0% +we're sort of waiting the the the sender +has perhaps has data to send but it + + align:start position:0% +has perhaps has data to send but it + + + align:start position:0% +has perhaps has data to send but it +hasn't received the message to send more + + align:start position:0% +hasn't received the message to send more + + + align:start position:0% +hasn't received the message to send more +that the it could the receiver can + + align:start position:0% +that the it could the receiver can + + + align:start position:0% +that the it could the receiver can +accept more messages and the receiver + + align:start position:0% +accept more messages and the receiver + + + align:start position:0% +accept more messages and the receiver +maybe has processed some of the messages + + align:start position:0% +maybe has processed some of the messages + + + align:start position:0% +maybe has processed some of the messages +that it's received but it hasn't yet + + align:start position:0% +that it's received but it hasn't yet + + + align:start position:0% +that it's received but it hasn't yet +sent this message uh over to it hasn't + + align:start position:0% +sent this message uh over to it hasn't + + + align:start position:0% +sent this message uh over to it hasn't +yet asked the sender to go ahead and + + align:start position:0% +yet asked the sender to go ahead and + + + align:start position:0% +yet asked the sender to go ahead and +send any additional data so the way that + + align:start position:0% +send any additional data so the way that + + + align:start position:0% +send any additional data so the way that +we're going to fix this um is to use + + align:start position:0% +we're going to fix this um is to use + + + align:start position:0% +we're going to fix this um is to use +something called a sliding window + + align:start position:0% +something called a sliding window + + + align:start position:0% +something called a sliding window +technique and the idea is that when the + + align:start position:0% +technique and the idea is that when the + + + align:start position:0% +technique and the idea is that when the +receiver rather than the receiver + + align:start position:0% +receiver rather than the receiver + + + align:start position:0% +receiver rather than the receiver +waiting until it has processed the whole + + align:start position:0% +waiting until it has processed the whole + + + align:start position:0% +waiting until it has processed the whole +Windows worth of data when the receiver + + align:start position:0% +Windows worth of data when the receiver + + + align:start position:0% +Windows worth of data when the receiver +processes one or it processes each + + align:start position:0% +processes one or it processes each + + + align:start position:0% +processes one or it processes each +message within its window so if this + + align:start position:0% +message within its window so if this + + + align:start position:0% +message within its window so if this +window is four messages big once it's + + align:start position:0% +window is four messages big once it's + + + align:start position:0% +window is four messages big once it's +processed the first message it's going + + align:start position:0% +processed the first message it's going + + + align:start position:0% +processed the first message it's going +to go ahead and indicate that to the + + align:start position:0% +to go ahead and indicate that to the + + + align:start position:0% +to go ahead and indicate that to the +sender so that the sender can then go + + align:start position:0% +sender so that the sender can then go + + + align:start position:0% +sender so that the sender can then go +ahead and send additional messages so + + align:start position:0% +ahead and send additional messages so + + + align:start position:0% +ahead and send additional messages so +rather than this window sort of moving + + align:start position:0% +rather than this window sort of moving + + + align:start position:0% +rather than this window sort of moving +rather than sort of getting four new + + align:start position:0% +rather than sort of getting four new + + + align:start position:0% +rather than sort of getting four new +messages at a time what we're going to + + align:start position:0% +messages at a time what we're going to + + + align:start position:0% +messages at a time what we're going to +do is we're going to send our first four + + align:start position:0% +do is we're going to send our first four + + + align:start position:0% +do is we're going to send our first four +messages and then we're going to just + + align:start position:0% +messages and then we're going to just + + + align:start position:0% +messages and then we're going to just +send one additional message at a time so + + align:start position:0% +send one additional message at a time so + + + align:start position:0% +send one additional message at a time so +that's why we call the window we say the + + align:start position:0% +that's why we call the window we say the + + + align:start position:0% +that's why we call the window we say the +window is sliding because we're going to + + align:start position:0% +window is sliding because we're going to + + + align:start position:0% +window is sliding because we're going to +sort of allow the sender to send an + + align:start position:0% +sort of allow the sender to send an + + + align:start position:0% +sort of allow the sender to send an +additional message whenever it is that + + align:start position:0% +additional message whenever it is that + + + align:start position:0% +additional message whenever it is that +the receiver has Pro finished processing + + align:start position:0% +the receiver has Pro finished processing + + + align:start position:0% +the receiver has Pro finished processing +just one message and the way we're going + + align:start position:0% +just one message and the way we're going + + + align:start position:0% +just one message and the way we're going +to do this again um we're going to + + align:start position:0% +to do this again um we're going to + + + align:start position:0% +to do this again um we're going to +initially negotiate a window + + align:start position:0% +initially negotiate a window + + + align:start position:0% +initially negotiate a window +size um and then when the sender starts + + align:start position:0% +size um and then when the sender starts + + + align:start position:0% +size um and then when the sender starts +sending it's going to do the same thing + + align:start position:0% +sending it's going to do the same thing + + + align:start position:0% +sending it's going to do the same thing +it's going to send all four of these + + align:start position:0% +it's going to send all four of these + + + align:start position:0% +it's going to send all four of these +messages um I've sort of halted this + + align:start position:0% +messages um I've sort of halted this + + + align:start position:0% +messages um I've sort of halted this +animation in the middle of it so I can + + align:start position:0% +animation in the middle of it so I can + + + align:start position:0% +animation in the middle of it so I can +show you an intermediate step but what + + align:start position:0% +show you an intermediate step but what + + + align:start position:0% +show you an intermediate step but what +would really be happening here is the + + align:start position:0% +would really be happening here is the + + + align:start position:0% +would really be happening here is the +sender would sort of send all the + + align:start position:0% +sender would sort of send all the + + + align:start position:0% +sender would sort of send all the +messages that were in the window um and + + align:start position:0% +messages that were in the window um and + + + align:start position:0% +messages that were in the window um and +then the receiver would begin processing + + align:start position:0% +then the receiver would begin processing + + + align:start position:0% +then the receiver would begin processing +them so now the the receiver begins + + align:start position:0% +them so now the the receiver begins + + + align:start position:0% +them so now the the receiver begins +processing this message and suppose the + + align:start position:0% +processing this message and suppose the + + + align:start position:0% +processing this message and suppose the +the first message so suppose it finishes + + align:start position:0% +the first message so suppose it finishes + + + align:start position:0% +the first message so suppose it finishes +processing segment one um before it + + align:start position:0% +processing segment one um before it + + + align:start position:0% +processing segment one um before it +receives uh the the segment two from the + + align:start position:0% +receives uh the the segment two from the + + + align:start position:0% +receives uh the the segment two from the +from the cender so now what it can do is + + align:start position:0% +from the cender so now what it can do is + + + align:start position:0% +from the cender so now what it can do is +in its acknowledgement for Segment two + + align:start position:0% +in its acknowledgement for Segment two + + + align:start position:0% +in its acknowledgement for Segment two +it can piggyback again using this idea + + align:start position:0% +it can piggyback again using this idea + + + align:start position:0% +it can piggyback again using this idea +can stick a little bit of information + + align:start position:0% +can stick a little bit of information + + + align:start position:0% +can stick a little bit of information +onto the acknowledgement that says oh + + align:start position:0% +onto the acknowledgement that says oh + + + align:start position:0% +onto the acknowledgement that says oh +and by the way I have finished + + align:start position:0% +and by the way I have finished + + + align:start position:0% +and by the way I have finished +processing one of these messages you can + + align:start position:0% +processing one of these messages you can + + + align:start position:0% +processing one of these messages you can +go ahead and send one more additional + + align:start position:0% +go ahead and send one more additional + + + align:start position:0% +go ahead and send one more additional +message you can slide the window by one + + align:start position:0% +message you can slide the window by one + + + align:start position:0% +message you can slide the window by one +okay + + align:start position:0% +okay + + + align:start position:0% +okay +um so I'm going to hit the next step of + + align:start position:0% +um so I'm going to hit the next step of + + + align:start position:0% +um so I'm going to hit the next step of +this animation and it's going to zip by + + align:start position:0% +this animation and it's going to zip by + + + align:start position:0% +this animation and it's going to zip by +really fast um don't I I'll explain what + + align:start position:0% +really fast um don't I I'll explain what + + + align:start position:0% +really fast um don't I I'll explain what +what's what's happening but don't try + + align:start position:0% +what's what's happening but don't try + + + align:start position:0% +what's what's happening but don't try +and worry too much about exactly + + align:start position:0% +and worry too much about exactly + + + align:start position:0% +and worry too much about exactly +following the details um okay so what + + align:start position:0% +following the details um okay so what + + + align:start position:0% +following the details um okay so what +happened here is now so now what what uh + + align:start position:0% +happened here is now so now what what uh + + + align:start position:0% +happened here is now so now what what uh +what happens is that the receiver sort + + align:start position:0% +what happens is that the receiver sort + + + align:start position:0% +what happens is that the receiver sort +of continues to process these messages + + align:start position:0% +of continues to process these messages + + + align:start position:0% +of continues to process these messages +as it arrives and then it continues to + + align:start position:0% +as it arrives and then it continues to + + + align:start position:0% +as it arrives and then it continues to +uh piggyback this acknow this + + align:start position:0% +uh piggyback this acknow this + + + align:start position:0% +uh piggyback this acknow this +information about the fact that it has + + align:start position:0% +information about the fact that it has + + + align:start position:0% +information about the fact that it has +finished sending + + align:start position:0% +finished sending + + + align:start position:0% +finished sending +uh some some messages onto the + + align:start position:0% +uh some some messages onto the + + + align:start position:0% +uh some some messages onto the +acknowledgements finished processing + + align:start position:0% +acknowledgements finished processing + + + align:start position:0% +acknowledgements finished processing +some messages onto the acknowledgements + + align:start position:0% +some messages onto the acknowledgements + + + align:start position:0% +some messages onto the acknowledgements +um if their sender if the receiver + + align:start position:0% +um if their sender if the receiver + + + align:start position:0% +um if their sender if the receiver +doesn't have any acknowledgements to + + align:start position:0% +doesn't have any acknowledgements to + + + align:start position:0% +doesn't have any acknowledgements to +send which was the case for these last + + align:start position:0% +send which was the case for these last + + + align:start position:0% +send which was the case for these last +two messages that it sent out here that + + align:start position:0% +two messages that it sent out here that + + + align:start position:0% +two messages that it sent out here that +I have labeled send more it may need to + + align:start position:0% +I have labeled send more it may need to + + + align:start position:0% +I have labeled send more it may need to +send these sort of uh Slide the window + + align:start position:0% +send these sort of uh Slide the window + + + align:start position:0% +send these sort of uh Slide the window +messages out by itself with without + + align:start position:0% +messages out by itself with without + + + align:start position:0% +messages out by itself with without +acknowledgement so here it sends a + + align:start position:0% +acknowledgement so here it sends a + + + align:start position:0% +acknowledgement so here it sends a +couple of additional messages that say + + align:start position:0% +couple of additional messages that say + + + align:start position:0% +couple of additional messages that say +go ahead and uh send me some more + + align:start position:0% +go ahead and uh send me some more + + + align:start position:0% +go ahead and uh send me some more +data okay so in this way now what we've + + align:start position:0% +data okay so in this way now what we've + + + align:start position:0% +data okay so in this way now what we've +done is we've managed to make it so that + + align:start position:0% +done is we've managed to make it so that + + + align:start position:0% +done is we've managed to make it so that +the uh send + + align:start position:0% +the uh send + + + align:start position:0% +the uh send +so so that the sender can send + + align:start position:0% +so so that the sender can send + + + align:start position:0% +so so that the sender can send +additional information before all of the + + align:start position:0% +additional information before all of the + + + align:start position:0% +additional information before all of the +uh sort of messages in the initial in + + align:start position:0% +uh sort of messages in the initial in + + + align:start position:0% +uh sort of messages in the initial in +the initial window were processed by the + + align:start position:0% +the initial window were processed by the + + + align:start position:0% +the initial window were processed by the +receiver so you see that uh + + align:start position:0% +receiver so you see that uh + + + align:start position:0% +receiver so you see that uh +the before the sender sends excuse me + + align:start position:0% +the before the sender sends excuse me + + + align:start position:0% +the before the sender sends excuse me +before the receiver actually requests + + align:start position:0% +before the receiver actually requests + + + align:start position:0% +before the receiver actually requests +you know sends a message requesting a + + align:start position:0% +you know sends a message requesting a + + + align:start position:0% +you know sends a message requesting a +whole new window SI window worth of data + + align:start position:0% +whole new window SI window worth of data + + + align:start position:0% +whole new window SI window worth of data +so you see now that some of the uh sort + + align:start position:0% +so you see now that some of the uh sort + + + align:start position:0% +so you see now that some of the uh sort +of go ahead and send more messages from + + align:start position:0% +of go ahead and send more messages from + + + align:start position:0% +of go ahead and send more messages from +the receiver arrive at the sender after + + align:start position:0% +the receiver arrive at the sender after + + + align:start position:0% +the receiver arrive at the sender after +the time that the + + align:start position:0% +the time that the + + + align:start position:0% +the time that the +um a after the time that the the sender + + align:start position:0% +um a after the time that the the sender + + + align:start position:0% +um a after the time that the the sender +starts Pro sending messages this fifth + + align:start position:0% +starts Pro sending messages this fifth + + + align:start position:0% +starts Pro sending messages this fifth +and sixth meage message to be go ahead + + align:start position:0% +and sixth meage message to be go ahead + + + align:start position:0% +and sixth meage message to be go ahead +and process so we managed to sort of + + align:start position:0% +and process so we managed to sort of + + + align:start position:0% +and process so we managed to sort of +increase the amount of concurrent + + align:start position:0% +increase the amount of concurrent + + + align:start position:0% +increase the amount of concurrent +processing that we can do in this + + align:start position:0% +processing that we can do in this + + + align:start position:0% +processing that we can do in this +network um but there's still are periods + + align:start position:0% +network um but there's still are periods + + + align:start position:0% +network um but there's still are periods +where the network is sort of idle where + + align:start position:0% +where the network is sort of idle where + + + align:start position:0% +where the network is sort of idle where +we're not actually where the sender and + + align:start position:0% +we're not actually where the sender and + + + align:start position:0% +we're not actually where the sender and +receiver are sort of not not + + align:start position:0% +receiver are sort of not not + + + align:start position:0% +receiver are sort of not not +transmitting data so we haven't done + + align:start position:0% +transmitting data so we haven't done + + + align:start position:0% +transmitting data so we haven't done +quite as good a job as maybe we would + + align:start position:0% +quite as good a job as maybe we would + + + align:start position:0% +quite as good a job as maybe we would +like um and the reason we haven't done + + align:start position:0% +like um and the reason we haven't done + + + align:start position:0% +like um and the reason we haven't done +quite as good a job as maybe we would + + align:start position:0% +quite as good a job as maybe we would + + + align:start position:0% +quite as good a job as maybe we would +like is that the sender that that when + + align:start position:0% +like is that the sender that that when + + + align:start position:0% +like is that the sender that that when +the receiver so so the property that we + + align:start position:0% +the receiver so so the property that we + + + align:start position:0% +the receiver so so the property that we +would like to enforce is that when the + + align:start position:0% +would like to enforce is that when the + + + align:start position:0% +would like to enforce is that when the +receiver says go ahead and uh go ahead + + align:start position:0% +receiver says go ahead and uh go ahead + + + align:start position:0% +receiver says go ahead and uh go ahead +and send me a new message when the + + align:start position:0% +and send me a new message when the + + + align:start position:0% +and send me a new message when the +receiver says Slide the window by one by + + align:start position:0% +receiver says Slide the window by one by + + + align:start position:0% +receiver says Slide the window by one by +the time that that the message the next + + align:start position:0% +the time that that the message the next + + + align:start position:0% +the time that that the message the next +message to process arrives from the + + align:start position:0% +message to process arrives from the + + + align:start position:0% +message to process arrives from the +sender we would like uh the receiver to + + align:start position:0% +sender we would like uh the receiver to + + + align:start position:0% +sender we would like uh the receiver to +uh still to not have uh reached the + + align:start position:0% +uh still to not have uh reached the + + + align:start position:0% +uh still to not have uh reached the +point where it's idle where it has to + + align:start position:0% +point where it's idle where it has to + + + align:start position:0% +point where it's idle where it has to +wait so we'd like the receiver's buffer + + align:start position:0% +wait so we'd like the receiver's buffer + + + align:start position:0% +wait so we'd like the receiver's buffer +to be big enough such that uh By the + + align:start position:0% +to be big enough such that uh By the + + + align:start position:0% +to be big enough such that uh By the +time its request for more data reaches + + align:start position:0% +time its request for more data reaches + + + align:start position:0% +time its request for more data reaches +the receiver and by the time the + + align:start position:0% +the receiver and by the time the + + + align:start position:0% +the receiver and by the time the +receiver's uh the sender and by the time + + align:start position:0% +receiver's uh the sender and by the time + + + align:start position:0% +receiver's uh the sender and by the time +the sender's uh uh response comes back + + align:start position:0% +the sender's uh uh response comes back + + + align:start position:0% +the sender's uh uh response comes back +we would like the receiver to still have + + align:start position:0% +we would like the receiver to still have + + + align:start position:0% +we would like the receiver to still have +some data to process whereas what's + + align:start position:0% +some data to process whereas what's + + + align:start position:0% +some data to process whereas what's +happened here is that the receiver + + align:start position:0% +happened here is that the receiver + + + align:start position:0% +happened here is that the receiver +finished processing all four messages in + + align:start position:0% +finished processing all four messages in + + + align:start position:0% +finished processing all four messages in +its buffer before this next message came + + align:start position:0% +its buffer before this next message came + + + align:start position:0% +its buffer before this next message came +back that with additional data for the + + align:start position:0% +back that with additional data for the + + + align:start position:0% +back that with additional data for the +receiver to process from the sender + + align:start position:0% +receiver to process from the sender + + + align:start position:0% +receiver to process from the sender +right so basically the problem was that + + align:start position:0% +right so basically the problem was that + + + align:start position:0% +right so basically the problem was that +the receiver's buffer wasn't quite large + + align:start position:0% +the receiver's buffer wasn't quite large + + + align:start position:0% +the receiver's buffer wasn't quite large +enough for it to it to uh be able to + + align:start position:0% +enough for it to it to uh be able to + + + align:start position:0% +enough for it to it to uh be able to +continuously process data uh while it uh + + align:start position:0% +continuously process data uh while it uh + + + align:start position:0% +continuously process data uh while it uh +for it to be able to it didn't have + + align:start position:0% +for it to be able to it didn't have + + + align:start position:0% +for it to be able to it didn't have +quite enough data for it to be able to + + align:start position:0% +quite enough data for it to be able to + + + align:start position:0% +quite enough data for it to be able to +continuously process while it waited for + + align:start position:0% +continuously process while it waited for + + + align:start position:0% +continuously process while it waited for +the sort of additional data to arrive + + align:start position:0% +the sort of additional data to arrive + + + align:start position:0% +the sort of additional data to arrive +from the + + align:start position:0% +from the + + + align:start position:0% +from the +sender so what we want is what this + + align:start position:0% +sender so what we want is what this + + + align:start position:0% +sender so what we want is what this +suggests that we want is to set this + + align:start position:0% +suggests that we want is to set this + + + align:start position:0% +suggests that we want is to set this +buffer size to set the size of the + + align:start position:0% +buffer size to set the size of the + + + align:start position:0% +buffer size to set the size of the +window to be uh the the appropriate size + + align:start position:0% +window to be uh the the appropriate size + + + align:start position:0% +window to be uh the the appropriate size +in order for the receiver to be able to + + align:start position:0% +in order for the receiver to be able to + + + align:start position:0% +in order for the receiver to be able to +sort of continuously process information + + align:start position:0% +sort of continuously process information + + + align:start position:0% +sort of continuously process information +um if at all + + align:start position:0% +um if at all + + + align:start position:0% +um if at all +possible so there's this question about + + align:start position:0% +possible so there's this question about + + + align:start position:0% +possible so there's this question about +how do we pick the window + + align:start position:0% + + + + align:start position:0% + +size so let's assume so the the problem + + align:start position:0% +size so let's assume so the the problem + + + align:start position:0% +size so let's assume so the the problem +we have is that small + + align:start position:0% + + + + align:start position:0% + +Windows imply uh underutilization of the + + align:start position:0% + + + + align:start position:0% + +network okay because we have both the + + align:start position:0% +network okay because we have both the + + + align:start position:0% +network okay because we have both the +cender and receiver are sort of Sitting + + align:start position:0% +cender and receiver are sort of Sitting + + + align:start position:0% +cender and receiver are sort of Sitting +Waiting there's times when there's no + + align:start position:0% +Waiting there's times when there's no + + + align:start position:0% +Waiting there's times when there's no +data that's actually trans that's being + + align:start position:0% +data that's actually trans that's being + + + align:start position:0% +data that's actually trans that's being +transferred across the + + align:start position:0% +transferred across the + + + align:start position:0% +transferred across the +network + + align:start position:0% +network + + + align:start position:0% +network +um so the question is then how big + + align:start position:0% +um so the question is then how big + + + align:start position:0% +um so the question is then how big +should we make the + + align:start position:0% + + + + align:start position:0% + +window what we said is we want the uh + + align:start position:0% +window what we said is we want the uh + + + align:start position:0% +window what we said is we want the uh +window size to be greater than the + + align:start position:0% +window size to be greater than the + + + align:start position:0% +window size to be greater than the +amount of time + + align:start position:0% + + + + align:start position:0% + +we want it to be long enough so that the + + align:start position:0% +we want it to be long enough so that the + + + align:start position:0% +we want it to be long enough so that the +receiver which say for example if the + + align:start position:0% +receiver which say for example if the + + + align:start position:0% +receiver which say for example if the +receiver can process some number of + + align:start position:0% +receiver can process some number of + + + align:start position:0% +receiver can process some number of +messages rate messages per second okay + + align:start position:0% +messages rate messages per second okay + + + align:start position:0% +messages rate messages per second okay +the receiver can process this many + + align:start position:0% +the receiver can process this many + + + align:start position:0% +the receiver can process this many +messages uh we want the its buffer uh to + + align:start position:0% +messages uh we want the its buffer uh to + + + align:start position:0% +messages uh we want the its buffer uh to +be large enough that uh the it if it + + align:start position:0% +be large enough that uh the it if it + + + align:start position:0% +be large enough that uh the it if it +processes that many messages per second + + align:start position:0% +processes that many messages per second + + + align:start position:0% +processes that many messages per second +that the amount of time for an + + align:start position:0% +that the amount of time for an + + + align:start position:0% +that the amount of time for an +additional additional messages for it to + + align:start position:0% +additional additional messages for it to + + + align:start position:0% +additional additional messages for it to +process that that it will still have + + align:start position:0% +process that that it will still have + + + align:start position:0% +process that that it will still have +messages to process by the time + + align:start position:0% +messages to process by the time + + + align:start position:0% +messages to process by the time +additional messages arrive from the + + align:start position:0% +additional messages arrive from the + + + align:start position:0% +additional messages arrive from the +sender so + + align:start position:0% +sender so + + + align:start position:0% +sender so +um the amount of time that it takes for + + align:start position:0% +um the amount of time that it takes for + + + align:start position:0% +um the amount of time that it takes for +a message to arrive additional messages + + align:start position:0% +a message to arrive additional messages + + + align:start position:0% +a message to arrive additional messages +to arrive from the sender from the time + + align:start position:0% +to arrive from the sender from the time + + + align:start position:0% +to arrive from the sender from the time +that this guy first sends this uh okay + + align:start position:0% +that this guy first sends this uh okay + + + align:start position:0% +that this guy first sends this uh okay +to send more message right is one + + align:start position:0% +to send more message right is one + + + align:start position:0% +to send more message right is one +roundtrip time of the network so it + + align:start position:0% +roundtrip time of the network so it + + + align:start position:0% +roundtrip time of the network so it +takes one roundtrip time of the network + + align:start position:0% +takes one roundtrip time of the network + + + align:start position:0% +takes one roundtrip time of the network +for the the sender for the for the + + align:start position:0% +for the the sender for the for the + + + align:start position:0% +for the the sender for the for the +receiver to receive additional messages + + align:start position:0% +receiver to receive additional messages + + + align:start position:0% +receiver to receive additional messages +to process from the sender um and the + + align:start position:0% +to process from the sender um and the + + + align:start position:0% +to process from the sender um and the +number of messages that it will process + + align:start position:0% +number of messages that it will process + + + align:start position:0% +number of messages that it will process +during that round trip time is whatever + + align:start position:0% +during that round trip time is whatever + + + align:start position:0% +during that round trip time is whatever +it message processing rate is times the + + align:start position:0% +it message processing rate is times the + + + align:start position:0% +it message processing rate is times the +roundtrip time of the network um and so + + align:start position:0% +roundtrip time of the network um and so + + + align:start position:0% +roundtrip time of the network um and so +therefore this is sort of ideally how we + + align:start position:0% +therefore this is sort of ideally how we + + + align:start position:0% +therefore this is sort of ideally how we +would set the window size in this + + align:start position:0% +would set the window size in this + + + align:start position:0% +would set the window size in this +network of course we talked about before + + align:start position:0% +network of course we talked about before + + + align:start position:0% +network of course we talked about before +How It's tricky to estimate this sort of + + align:start position:0% +How It's tricky to estimate this sort of + + + align:start position:0% +How It's tricky to estimate this sort of +ewma thing that we do to estimate the + + align:start position:0% +ewma thing that we do to estimate the + + + align:start position:0% +ewma thing that we do to estimate the +window size is not a perfect estimator + + align:start position:0% +window size is not a perfect estimator + + + align:start position:0% +window size is not a perfect estimator +um but we're going to try and sort of + + align:start position:0% +um but we're going to try and sort of + + + align:start position:0% +um but we're going to try and sort of +set this we're we're going to this is + + align:start position:0% +set this we're we're going to this is + + + align:start position:0% +set this we're we're going to this is +this is going to be a sort of good + + align:start position:0% +this is going to be a sort of good + + + align:start position:0% +this is going to be a sort of good +choice for a window size to use um and + + align:start position:0% +choice for a window size to use um and + + + align:start position:0% +choice for a window size to use um and +so typically the the receiver is the + + align:start position:0% +so typically the the receiver is the + + + align:start position:0% +so typically the the receiver is the +receiver is going to try and sort of use + + align:start position:0% +receiver is going to try and sort of use + + + align:start position:0% +receiver is going to try and sort of use +some rough estimate of what it thinks + + align:start position:0% +some rough estimate of what it thinks + + + align:start position:0% +some rough estimate of what it thinks +the round trip time is and the rate + + align:start position:0% +the round trip time is and the rate + + + align:start position:0% +the round trip time is and the rate +process the rate at which it can process + + align:start position:0% +process the rate at which it can process + + + align:start position:0% +process the rate at which it can process +messages when it informs the cender of + + align:start position:0% +messages when it informs the cender of + + + align:start position:0% +messages when it informs the cender of +the uh sort of the window size at the + + align:start position:0% +the uh sort of the window size at the + + + align:start position:0% +the uh sort of the window size at the +initiation of the + + align:start position:0% +initiation of the + + + align:start position:0% +initiation of the +connection okay so this basically um is + + align:start position:0% +connection okay so this basically um is + + + align:start position:0% +connection okay so this basically um is +going to wrap up our discussion of the + + align:start position:0% +going to wrap up our discussion of the + + + align:start position:0% +going to wrap up our discussion of the +end to-end layer or of this the the sort + + align:start position:0% +end to-end layer or of this the the sort + + + align:start position:0% +end to-end layer or of this the the sort +of the loss recovery issues in the end + + align:start position:0% +of the loss recovery issues in the end + + + align:start position:0% +of the loss recovery issues in the end +to-end layer what we're going to talk + + align:start position:0% +to-end layer what we're going to talk + + + align:start position:0% +to-end layer what we're going to talk +about next time um is this issue of how + + align:start position:0% +about next time um is this issue of how + + + align:start position:0% +about next time um is this issue of how +we deal with congestion right so we said + + align:start position:0% +we deal with congestion right so we said + + + align:start position:0% +we deal with congestion right so we said +that in one of these networks there be + + align:start position:0% +that in one of these networks there be + + + align:start position:0% +that in one of these networks there be +uh in one of these networks there can be + + align:start position:0% +uh in one of these networks there can be + + + align:start position:0% +uh in one of these networks there can be +all these delays due to queuing um and + + align:start position:0% +all these delays due to queuing um and + + + align:start position:0% +all these delays due to queuing um and +that these delays can introduce + + align:start position:0% +that these delays can introduce + + + align:start position:0% +that these delays can introduce +additional loss and we call these delays + + align:start position:0% +additional loss and we call these delays + + + align:start position:0% +additional loss and we call these delays +congestion and so the what we're going + + align:start position:0% +congestion and so the what we're going + + + align:start position:0% +congestion and so the what we're going +to talk about next time is how we + + align:start position:0% +to talk about next time is how we + + + align:start position:0% +to talk about next time is how we +actually deal with congestion how we + + align:start position:0% +actually deal with congestion how we + + + align:start position:0% +actually deal with congestion how we +respond to congestion okay so we'll see + + align:start position:0% +respond to congestion okay so we'll see + + + align:start position:0% +respond to congestion okay so we'll see +you on Wednesday \ No newline at end of file diff --git a/ZDQk45NQbEo.txt b/ZDQk45NQbEo.txt new file mode 100644 index 0000000000000000000000000000000000000000..190bcd1b6e89d7534abb4dcdac7b07bd3db82f2f --- /dev/null +++ b/ZDQk45NQbEo.txt @@ -0,0 +1,2200 @@ +align:start position:0% + +we've considered arithmetic sums where + + align:start position:0% +we've considered arithmetic sums where + + + align:start position:0% +we've considered arithmetic sums where +each term is a fixed amount larger than + + align:start position:0% +each term is a fixed amount larger than + + + align:start position:0% +each term is a fixed amount larger than +the previous term by an additive amount + + align:start position:0% +the previous term by an additive amount + + + align:start position:0% +the previous term by an additive amount +another kind of sum called geometric + + align:start position:0% +another kind of sum called geometric + + + align:start position:0% +another kind of sum called geometric +sums which we're going to look at now + + align:start position:0% +sums which we're going to look at now + + + align:start position:0% +sums which we're going to look at now +come about where each sum is a fixed + + align:start position:0% +come about where each sum is a fixed + + + align:start position:0% +come about where each sum is a fixed +multiple of the previous sum and + + align:start position:0% +multiple of the previous sum and + + + align:start position:0% +multiple of the previous sum and +these come up all the time in lots of + + align:start position:0% +these come up all the time in lots of + + + align:start position:0% +these come up all the time in lots of +different settings in this particular + + align:start position:0% +different settings in this particular + + + align:start position:0% +different settings in this particular +case we're going to look at an example + + align:start position:0% +case we're going to look at an example + + + align:start position:0% +case we're going to look at an example +of how it applies to + + align:start position:0% +of how it applies to + + + align:start position:0% +of how it applies to +analyzing the value of money in the + + align:start position:0% +analyzing the value of money in the + + + align:start position:0% +analyzing the value of money in the +future so let's begin with a geometric + + align:start position:0% +future so let's begin with a geometric + + + align:start position:0% +future so let's begin with a geometric +sum and there's the standard form of it + + align:start position:0% +sum and there's the standard form of it + + + align:start position:0% +sum and there's the standard form of it +geometric sum is of the form uh 1 plus x + + align:start position:0% +geometric sum is of the form uh 1 plus x + + + align:start position:0% +geometric sum is of the form uh 1 plus x +plus x squared up through the nth power + + align:start position:0% +plus x squared up through the nth power + + + align:start position:0% +plus x squared up through the nth power +of x and for uniformly notice that 1 is + + align:start position:0% +of x and for uniformly notice that 1 is + + + align:start position:0% +of x and for uniformly notice that 1 is +actually x to the zero so we're taking + + align:start position:0% +actually x to the zero so we're taking + + + align:start position:0% +actually x to the zero so we're taking +the sum from and from k equals 0 to n of + + align:start position:0% +the sum from and from k equals 0 to n of + + + align:start position:0% +the sum from and from k equals 0 to n of +x to the k + + align:start position:0% +x to the k + + + align:start position:0% +x to the k +now what i'd like to do is find a nice + + align:start position:0% +now what i'd like to do is find a nice + + + align:start position:0% +now what i'd like to do is find a nice +closed form for this without those + + align:start position:0% +closed form for this without those + + + align:start position:0% +closed form for this without those +ellipses uh and and having a growing + + align:start position:0% +ellipses uh and and having a growing + + + align:start position:0% +ellipses uh and and having a growing +number of terms n and there's a simple + + align:start position:0% +number of terms n and there's a simple + + + align:start position:0% +number of terms n and there's a simple +trick with the arithmetic sum the way + + align:start position:0% +trick with the arithmetic sum the way + + + align:start position:0% +trick with the arithmetic sum the way +gauss got it and the way we got it was + + align:start position:0% +gauss got it and the way we got it was + + + align:start position:0% +gauss got it and the way we got it was +by reversing the summonating the things + + align:start position:0% +by reversing the summonating the things + + + align:start position:0% +by reversing the summonating the things +together this time the trick is to + + align:start position:0% +together this time the trick is to + + + align:start position:0% +together this time the trick is to +multiply gn by x + + align:start position:0% +multiply gn by x + + + align:start position:0% +multiply gn by x +now what's that going to do is it's + + align:start position:0% +now what's that going to do is it's + + + align:start position:0% +now what's that going to do is it's +going to increase the power of x in each + + align:start position:0% +going to increase the power of x in each + + + align:start position:0% +going to increase the power of x in each +term by one + + align:start position:0% +term by one + + + align:start position:0% +term by one +which is tantamount to a right shift + + align:start position:0% +which is tantamount to a right shift + + + align:start position:0% +which is tantamount to a right shift +let's look at that there's x g of n so + + align:start position:0% +let's look at that there's x g of n so + + + align:start position:0% +let's look at that there's x g of n so +uh uh one times x of course i'm + + align:start position:0% +uh uh one times x of course i'm + + + align:start position:0% +uh uh one times x of course i'm +subtracting looking ahead so one times x + + align:start position:0% +subtracting looking ahead so one times x + + + align:start position:0% +subtracting looking ahead so one times x +is minus l minus x um + + align:start position:0% +is minus l minus x um + + + align:start position:0% +is minus l minus x um + + align:start position:0% + + + align:start position:0% +x times + + align:start position:0% +x times + + + align:start position:0% +x times +x is x squared i'm going to subtract it + + align:start position:0% +x is x squared i'm going to subtract it + + + align:start position:0% +x is x squared i'm going to subtract it +down through + + align:start position:0% +down through + + + align:start position:0% +down through +x to the n minus 1 times x gives me the + + align:start position:0% +x to the n minus 1 times x gives me the + + + align:start position:0% +x to the n minus 1 times x gives me the +x to the n term and finally i have an + + align:start position:0% +x to the n term and finally i have an + + + align:start position:0% +x to the n term and finally i have an +extra term from right shifting x to the + + align:start position:0% +extra term from right shifting x to the + + + align:start position:0% +extra term from right shifting x to the +n to be x to the n plus 1. now let's do + + align:start position:0% +n to be x to the n plus 1. now let's do + + + align:start position:0% +n to be x to the n plus 1. now let's do +this subtraction + + align:start position:0% +this subtraction + + + align:start position:0% +this subtraction +but of course i'm going to line the + + align:start position:0% +but of course i'm going to line the + + + align:start position:0% +but of course i'm going to line the +terms up so that they're easy to + + align:start position:0% +terms up so that they're easy to + + + align:start position:0% +terms up so that they're easy to +subtract and now all the terms in the + + align:start position:0% +subtract and now all the terms in the + + + align:start position:0% +subtract and now all the terms in the +middle cancel which is very cool because + + align:start position:0% +middle cancel which is very cool because + + + align:start position:0% +middle cancel which is very cool because +we've just figured out that gn minus xgn + + align:start position:0% +we've just figured out that gn minus xgn + + + align:start position:0% +we've just figured out that gn minus xgn +is 1 minus + + align:start position:0% +is 1 minus + + + align:start position:0% +is 1 minus +x to the n plus 1. so we have this nice + + align:start position:0% +x to the n plus 1. so we have this nice + + + align:start position:0% +x to the n plus 1. so we have this nice +elegant formula now i can factor out gn + + align:start position:0% +elegant formula now i can factor out gn + + + align:start position:0% +elegant formula now i can factor out gn +and i get a gn times 1 minus x on the + + align:start position:0% +and i get a gn times 1 minus x on the + + + align:start position:0% +and i get a gn times 1 minus x on the +left + + align:start position:0% +left + + + align:start position:0% +left +and the result is that i get the gn is 1 + + align:start position:0% +and the result is that i get the gn is 1 + + + align:start position:0% +and the result is that i get the gn is 1 +minus x to the n plus 1 over 1 minus x + + align:start position:0% +minus x to the n plus 1 over 1 minus x + + + align:start position:0% +minus x to the n plus 1 over 1 minus x +this is actually a formula that we + + align:start position:0% +this is actually a formula that we + + + align:start position:0% +this is actually a formula that we +proved before by induction but when we + + align:start position:0% +proved before by induction but when we + + + align:start position:0% +proved before by induction but when we +did it by induction there was no clue + + align:start position:0% +did it by induction there was no clue + + + align:start position:0% +did it by induction there was no clue +about + + align:start position:0% +about + + + align:start position:0% +about +who was the clever person to think of + + align:start position:0% +who was the clever person to think of + + + align:start position:0% +who was the clever person to think of +this formula now you know how that + + align:start position:0% +this formula now you know how that + + + align:start position:0% +this formula now you know how that +clever person uh found it and that's + + align:start position:0% +clever person uh found it and that's + + + align:start position:0% +clever person uh found it and that's +kind of a standard trick that we'll see + + align:start position:0% +kind of a standard trick that we'll see + + + align:start position:0% +kind of a standard trick that we'll see +more of when we look at generating + + align:start position:0% +more of when we look at generating + + + align:start position:0% +more of when we look at generating +functions but for now um it's a simple + + align:start position:0% +functions but for now um it's a simple + + + align:start position:0% +functions but for now um it's a simple +trick for getting a nice closed form for + + align:start position:0% +trick for getting a nice closed form for + + + align:start position:0% +trick for getting a nice closed form for +a sum we refer to as the perturbation + + align:start position:0% +a sum we refer to as the perturbation + + + align:start position:0% +a sum we refer to as the perturbation +method you take the sum you perturb it a + + align:start position:0% +method you take the sum you perturb it a + + + align:start position:0% +method you take the sum you perturb it a +little see how it relates to itself get + + align:start position:0% +little see how it relates to itself get + + + align:start position:0% +little see how it relates to itself get +an arithmetic relation and solve for a + + align:start position:0% +an arithmetic relation and solve for a + + + align:start position:0% +an arithmetic relation and solve for a +formula for the sum + + align:start position:0% +formula for the sum + + + align:start position:0% +formula for the sum +okay um + + align:start position:0% +okay um + + + align:start position:0% +okay um +a geometric series i use the word sum + + align:start position:0% +a geometric series i use the word sum + + + align:start position:0% +a geometric series i use the word sum +for a finite sum geometric series is + + align:start position:0% +for a finite sum geometric series is + + + align:start position:0% +for a finite sum geometric series is +when you take an infinite sum so the + + align:start position:0% +when you take an infinite sum so the + + + align:start position:0% +when you take an infinite sum so the +infinite geometric sum is the sum 1 plus + + align:start position:0% +infinite geometric sum is the sum 1 plus + + + align:start position:0% +infinite geometric sum is the sum 1 plus +x plus x squared x to the n and it keeps + + align:start position:0% +x plus x squared x to the n and it keeps + + + align:start position:0% +x plus x squared x to the n and it keeps +going it's the sum from i equals 0 to + + align:start position:0% +going it's the sum from i equals 0 to + + + align:start position:0% +going it's the sum from i equals 0 to +infinity of x to the i + + align:start position:0% +infinity of x to the i + + + align:start position:0% +infinity of x to the i +and there's a simple formula for that + + align:start position:0% +and there's a simple formula for that + + + align:start position:0% +and there's a simple formula for that +too it's even simpler actually because + + align:start position:0% +too it's even simpler actually because + + + align:start position:0% +too it's even simpler actually because +the definition of + + align:start position:0% +the definition of + + + align:start position:0% +the definition of +an infinite sum is it's the limit of the + + align:start position:0% +an infinite sum is it's the limit of the + + + align:start position:0% +an infinite sum is it's the limit of the +truncated sums it's the limit of the sum + + align:start position:0% +truncated sums it's the limit of the sum + + + align:start position:0% +truncated sums it's the limit of the sum +of the first n terms as n goes to + + align:start position:0% +of the first n terms as n goes to + + + align:start position:0% +of the first n terms as n goes to +infinity assuming that limit exists and + + align:start position:0% +infinity assuming that limit exists and + + + align:start position:0% +infinity assuming that limit exists and +so for uh the value of o of this + + align:start position:0% +so for uh the value of o of this + + + align:start position:0% +so for uh the value of o of this +infinite series is the limit of g n + + align:start position:0% +infinite series is the limit of g n + + + align:start position:0% +infinite series is the limit of g n +which is the sum up to n + + align:start position:0% +which is the sum up to n + + + align:start position:0% +which is the sum up to n +um and let's look at that well it's uh + + align:start position:0% +um and let's look at that well it's uh + + + align:start position:0% +um and let's look at that well it's uh +why it's g n is one minus x to the n + + align:start position:0% +why it's g n is one minus x to the n + + + align:start position:0% +why it's g n is one minus x to the n +plus one over one minus x so the limit + + align:start position:0% +plus one over one minus x so the limit + + + align:start position:0% +plus one over one minus x so the limit +of that the limits distribute past the + + align:start position:0% +of that the limits distribute past the + + + align:start position:0% +of that the limits distribute past the +one uh down to + + align:start position:0% +one uh down to + + + align:start position:0% +one uh down to +um and the x doesn't have an n in it so + + align:start position:0% +um and the x doesn't have an n in it so + + + align:start position:0% +um and the x doesn't have an n in it so +it winds up being um one minus the limit + + align:start position:0% +it winds up being um one minus the limit + + + align:start position:0% +it winds up being um one minus the limit +as n approaches infinity of x to the n + + align:start position:0% +as n approaches infinity of x to the n + + + align:start position:0% +as n approaches infinity of x to the n +plus one divided by one minus x and as + + align:start position:0% +plus one divided by one minus x and as + + + align:start position:0% +plus one divided by one minus x and as +long as x is less than one + + align:start position:0% +long as x is less than one + + + align:start position:0% +long as x is less than one +x to the n plus one is going to go to + + align:start position:0% +x to the n plus one is going to go to + + + align:start position:0% +x to the n plus one is going to go to +zero and i wind up with this nice simple + + align:start position:0% +zero and i wind up with this nice simple + + + align:start position:0% +zero and i wind up with this nice simple +formula that the uh infinite series uh + + align:start position:0% +formula that the uh infinite series uh + + + align:start position:0% +formula that the uh infinite series uh +the sum from i equals zero to infinity + + align:start position:0% +the sum from i equals zero to infinity + + + align:start position:0% +the sum from i equals zero to infinity +of x to the i is equal to one over one + + align:start position:0% +of x to the i is equal to one over one + + + align:start position:0% +of x to the i is equal to one over one +minus x + + align:start position:0% +minus x + + + align:start position:0% +minus x +providing that the magnitude of x is + + align:start position:0% +providing that the magnitude of x is + + + align:start position:0% +providing that the magnitude of x is +less than one okay that's the uh basics + + align:start position:0% +less than one okay that's the uh basics + + + align:start position:0% +less than one okay that's the uh basics +mathematical preliminaries of uh of + + align:start position:0% +mathematical preliminaries of uh of + + + align:start position:0% +mathematical preliminaries of uh of +geometric sums and geometric series now + + align:start position:0% +geometric sums and geometric series now + + + align:start position:0% +geometric sums and geometric series now +let's look at a typical application + + align:start position:0% +let's look at a typical application + + + align:start position:0% +let's look at a typical application +having to do with the future value of + + align:start position:0% +having to do with the future value of + + + align:start position:0% +having to do with the future value of +money + + align:start position:0% +money + + + align:start position:0% +money +suppose we want to make the following + + align:start position:0% +suppose we want to make the following + + + align:start position:0% +suppose we want to make the following +deal i promise i will pay you 100 in one + + align:start position:0% +deal i promise i will pay you 100 in one + + + align:start position:0% +deal i promise i will pay you 100 in one +year + + align:start position:0% +year + + + align:start position:0% +year +if you will pay me a fixed amount now + + align:start position:0% +if you will pay me a fixed amount now + + + align:start position:0% +if you will pay me a fixed amount now +so let's call it x dollars and the + + align:start position:0% +so let's call it x dollars and the + + + align:start position:0% +so let's call it x dollars and the +puzzle is + + align:start position:0% +puzzle is + + + align:start position:0% +puzzle is +how much money is a hundred dollars + + align:start position:0% +how much money is a hundred dollars + + + align:start position:0% +how much money is a hundred dollars +worth if you can't have it now you can + + align:start position:0% +worth if you can't have it now you can + + + align:start position:0% +worth if you can't have it now you can +only have it in one year it's worth x + + align:start position:0% +only have it in one year it's worth x + + + align:start position:0% +only have it in one year it's worth x +dollars how are we going to figure out + + align:start position:0% +dollars how are we going to figure out + + + align:start position:0% +dollars how are we going to figure out +what x should be what would be a fair + + align:start position:0% +what x should be what would be a fair + + + align:start position:0% +what x should be what would be a fair +amount for you to pay me so that i'm + + align:start position:0% +amount for you to pay me so that i'm + + + align:start position:0% +amount for you to pay me so that i'm +willing to pay you a hundred dollars in + + align:start position:0% +willing to pay you a hundred dollars in + + + align:start position:0% +willing to pay you a hundred dollars in +one year and it's fair nobody loses okay + + align:start position:0% +one year and it's fair nobody loses okay + + + align:start position:0% +one year and it's fair nobody loses okay +well here's the basic fact that is the + + align:start position:0% +well here's the basic fact that is the + + + align:start position:0% +well here's the basic fact that is the +basis for + + align:start position:0% +basis for + + + align:start position:0% +basis for +evaluating what the value of money in + + align:start position:0% +evaluating what the value of money in + + + align:start position:0% +evaluating what the value of money in +the future is is i'm going to assume + + align:start position:0% +the future is is i'm going to assume + + + align:start position:0% +the future is is i'm going to assume +that my bank will pay me 3 interest this + + align:start position:0% +that my bank will pay me 3 interest this + + + align:start position:0% +that my bank will pay me 3 interest this +is a generous bank in today's uh economy + + align:start position:0% +is a generous bank in today's uh economy + + + align:start position:0% +is a generous bank in today's uh economy +but it used to be a a stingy offer + + align:start position:0% +but it used to be a a stingy offer + + + align:start position:0% +but it used to be a a stingy offer +interest rates in my lifetime have + + align:start position:0% +interest rates in my lifetime have + + + align:start position:0% +interest rates in my lifetime have +ranged between about 17 a year down to + + align:start position:0% +ranged between about 17 a year down to + + + align:start position:0% +ranged between about 17 a year down to +uh less than one percent a year + + align:start position:0% +uh less than one percent a year + + + align:start position:0% +uh less than one percent a year +uh three percent a reasonable number to + + align:start position:0% +uh three percent a reasonable number to + + + align:start position:0% +uh three percent a reasonable number to +play with so let's suppose that my bank + + align:start position:0% +play with so let's suppose that my bank + + + align:start position:0% +play with so let's suppose that my bank +commits to paying me three percent + + align:start position:0% +commits to paying me three percent + + + align:start position:0% +commits to paying me three percent +interest uh on a deposit now that is to + + align:start position:0% +interest uh on a deposit now that is to + + + align:start position:0% +interest uh on a deposit now that is to +say uh let's define the bank rate b to + + align:start position:0% +say uh let's define the bank rate b to + + + align:start position:0% +say uh let's define the bank rate b to +be 1.03 and the deal is that the bank + + align:start position:0% +be 1.03 and the deal is that the bank + + + align:start position:0% +be 1.03 and the deal is that the bank +will increase the money that i have now + + align:start position:0% +will increase the money that i have now + + + align:start position:0% +will increase the money that i have now +by a factor of b in one year + + align:start position:0% +by a factor of b in one year + + + align:start position:0% +by a factor of b in one year +okay + + align:start position:0% +okay + + + align:start position:0% +okay +well so if i deposit your x dollars now + + align:start position:0% +well so if i deposit your x dollars now + + + align:start position:0% +well so if i deposit your x dollars now +i means i will have b times x dollars in + + align:start position:0% +i means i will have b times x dollars in + + + align:start position:0% +i means i will have b times x dollars in +one year + + align:start position:0% +one year + + + align:start position:0% +one year +okay assuming that the bank is + + align:start position:0% +okay assuming that the bank is + + + align:start position:0% +okay assuming that the bank is +completely reliable there's no risk + + align:start position:0% +completely reliable there's no risk + + + align:start position:0% +completely reliable there's no risk +there and it's and i get exactly b times + + align:start position:0% +there and it's and i get exactly b times + + + align:start position:0% +there and it's and i get exactly b times +x in one year then i won't lose any + + align:start position:0% +x in one year then i won't lose any + + + align:start position:0% +x in one year then i won't lose any +money + + align:start position:0% +money + + + align:start position:0% +money +providing that b times x is greater than + + align:start position:0% +providing that b times x is greater than + + + align:start position:0% +providing that b times x is greater than +or equal to 100. i need the x dollars + + align:start position:0% +or equal to 100. i need the x dollars + + + align:start position:0% +or equal to 100. i need the x dollars +you give me now to be worth the hundred + + align:start position:0% +you give me now to be worth the hundred + + + align:start position:0% +you give me now to be worth the hundred +dollars i'm supposed to pay you i'll + + align:start position:0% +dollars i'm supposed to pay you i'll + + + align:start position:0% +dollars i'm supposed to pay you i'll +come out ahead if bx is greater than or + + align:start position:0% +come out ahead if bx is greater than or + + + align:start position:0% +come out ahead if bx is greater than or +equal to 100. um + + align:start position:0% +equal to 100. um + + + align:start position:0% +equal to 100. um +i'll lose if it's less than 100 and it's + + align:start position:0% +i'll lose if it's less than 100 and it's + + + align:start position:0% +i'll lose if it's less than 100 and it's +a completely fair if bx is equal to 100. + + align:start position:0% +a completely fair if bx is equal to 100. + + + align:start position:0% +a completely fair if bx is equal to 100. +all right well that means that x is + + align:start position:0% +all right well that means that x is + + + align:start position:0% +all right well that means that x is +simply uh 100 over b which we decided + + align:start position:0% +simply uh 100 over b which we decided + + + align:start position:0% +simply uh 100 over b which we decided +was 1.03 9709 so a hundred dollars in + + align:start position:0% +was 1.03 9709 so a hundred dollars in + + + align:start position:0% +was 1.03 9709 so a hundred dollars in +one year + + align:start position:0% +one year + + + align:start position:0% +one year +is worth um + + align:start position:0% +is worth um + + + align:start position:0% +is worth um +uh + + align:start position:0% +uh + + + align:start position:0% +uh +97. + + align:start position:0% +97. + + + align:start position:0% +97. +and + + align:start position:0% +and + + + align:start position:0% +and +nine cents or normalizing to one dollar + + align:start position:0% +nine cents or normalizing to one dollar + + + align:start position:0% +nine cents or normalizing to one dollar +one dollar in one year is worth 97 cents + + align:start position:0% +one dollar in one year is worth 97 cents + + + align:start position:0% +one dollar in one year is worth 97 cents +essentially now + + align:start position:0% +essentially now + + + align:start position:0% +essentially now +well now we can shift perspective a + + align:start position:0% +well now we can shift perspective a + + + align:start position:0% +well now we can shift perspective a +little bit and think back a year + + align:start position:0% +little bit and think back a year + + + align:start position:0% +little bit and think back a year +so + + align:start position:0% +so + + + align:start position:0% +so +how much money did i need last year in + + align:start position:0% +how much money did i need last year in + + + align:start position:0% +how much money did i need last year in +order to be worth a dollar today well by + + align:start position:0% +order to be worth a dollar today well by + + + align:start position:0% +order to be worth a dollar today well by +the same reasoning the bank is going to + + align:start position:0% +the same reasoning the bank is going to + + + align:start position:0% +the same reasoning the bank is going to +pay me + + align:start position:0% +pay me + + + align:start position:0% +pay me +b times r today so i need b times r to + + align:start position:0% +b times r today so i need b times r to + + + align:start position:0% +b times r today so i need b times r to +equal a dollar in other words i r has + + align:start position:0% +equal a dollar in other words i r has + + + align:start position:0% +equal a dollar in other words i r has +got to be 1 over b r is one over the + + align:start position:0% +got to be 1 over b r is one over the + + + align:start position:0% +got to be 1 over b r is one over the +bank rate so a dollar a year ago is + + align:start position:0% +bank rate so a dollar a year ago is + + + align:start position:0% +bank rate so a dollar a year ago is +worth our dollars a year ago is worth a + + align:start position:0% +worth our dollars a year ago is worth a + + + align:start position:0% +worth our dollars a year ago is worth a +dollar today + + align:start position:0% +dollar today + + + align:start position:0% +dollar today +and by the same reasoning um + + align:start position:0% +and by the same reasoning um + + + align:start position:0% +and by the same reasoning um +uh n dollars paid in two years is worth + + align:start position:0% +uh n dollars paid in two years is worth + + + align:start position:0% +uh n dollars paid in two years is worth +n times r + + align:start position:0% +n times r + + + align:start position:0% +n times r +paid in one year which is worth n times + + align:start position:0% +paid in one year which is worth n times + + + align:start position:0% +paid in one year which is worth n times +r squared paid today paid today + + align:start position:0% +r squared paid today paid today + + + align:start position:0% +r squared paid today paid today +so i can iterate + + align:start position:0% +so i can iterate + + + align:start position:0% +so i can iterate +this bank of this one over bank rate + + align:start position:0% +this bank of this one over bank rate + + + align:start position:0% +this bank of this one over bank rate +factor and as time goes on uh k years + + align:start position:0% +factor and as time goes on uh k years + + + align:start position:0% +factor and as time goes on uh k years +out + + align:start position:0% +out + + + align:start position:0% +out +uh + + align:start position:0% +uh + + + align:start position:0% +uh +a value of n dollars paid in k years is + + align:start position:0% +a value of n dollars paid in k years is + + + align:start position:0% +a value of n dollars paid in k years is +worth + + align:start position:0% +worth + + + align:start position:0% +worth +n times r to the k today where r is one + + align:start position:0% +n times r to the k today where r is one + + + align:start position:0% +n times r to the k today where r is one +over the bank rate + + align:start position:0% +over the bank rate + + + align:start position:0% +over the bank rate +okay + + align:start position:0% +okay + + + align:start position:0% +okay +that's good to know + + align:start position:0% +that's good to know + + + align:start position:0% +that's good to know +um let's think about annuities now an + + align:start position:0% +um let's think about annuities now an + + + align:start position:0% +um let's think about annuities now an +annuity is a contract that people buy + + align:start position:0% +annuity is a contract that people buy + + + align:start position:0% +annuity is a contract that people buy +to provide income for themselves without + + align:start position:0% +to provide income for themselves without + + + align:start position:0% +to provide income for themselves without +risk so they will make a deal typically + + align:start position:0% +risk so they will make a deal typically + + + align:start position:0% +risk so they will make a deal typically +with insurance company where they will + + align:start position:0% +with insurance company where they will + + + align:start position:0% +with insurance company where they will +pay a certain amount of money now to the + + align:start position:0% +pay a certain amount of money now to the + + + align:start position:0% +pay a certain amount of money now to the +insurance company and the insurance + + align:start position:0% +insurance company and the insurance + + + align:start position:0% +insurance company and the insurance +company promises to provide them a + + align:start position:0% +company promises to provide them a + + + align:start position:0% +company promises to provide them a +regular income sometimes for life or + + align:start position:0% +regular income sometimes for life or + + + align:start position:0% +regular income sometimes for life or +sometimes for a fixed period so let's + + align:start position:0% +sometimes for a fixed period so let's + + + align:start position:0% +sometimes for a fixed period so let's +look at an example i will pay you one + + align:start position:0% +look at an example i will pay you one + + + align:start position:0% +look at an example i will pay you one +hundred dollars a year for ten years + + align:start position:0% +hundred dollars a year for ten years + + + align:start position:0% +hundred dollars a year for ten years +if you will pay me a fixed premium what + + align:start position:0% +if you will pay me a fixed premium what + + + align:start position:0% +if you will pay me a fixed premium what +should it be so i'm i'm gonna promise as + + align:start position:0% +should it be so i'm i'm gonna promise as + + + align:start position:0% +should it be so i'm i'm gonna promise as +the insurance company to pay you one + + align:start position:0% +the insurance company to pay you one + + + align:start position:0% +the insurance company to pay you one +hundred dollars a year for ten years i + + align:start position:0% +hundred dollars a year for ten years i + + + align:start position:0% +hundred dollars a year for ten years i +want you to pay me a a premium of why + + align:start position:0% +want you to pay me a a premium of why + + + align:start position:0% +want you to pay me a a premium of why +dollars now how much should you pay + + align:start position:0% +dollars now how much should you pay + + + align:start position:0% +dollars now how much should you pay +well let's think about it + + align:start position:0% +well let's think about it + + + align:start position:0% +well let's think about it +um + + align:start position:0% +um + + + align:start position:0% +um +one hundred dollars in one year is worth + + align:start position:0% +one hundred dollars in one year is worth + + + align:start position:0% +one hundred dollars in one year is worth +a hundred times r + + align:start position:0% +a hundred times r + + + align:start position:0% +a hundred times r +and one hundred dollars in two years is + + align:start position:0% +and one hundred dollars in two years is + + + align:start position:0% +and one hundred dollars in two years is +worth 100 times r squared and finally + + align:start position:0% +worth 100 times r squared and finally + + + align:start position:0% +worth 100 times r squared and finally +100 in 10 years is worth 100 times r to + + align:start position:0% +100 in 10 years is worth 100 times r to + + + align:start position:0% +100 in 10 years is worth 100 times r to +the 10th + + align:start position:0% +the 10th + + + align:start position:0% +the 10th +so this is the amount that i will have + + align:start position:0% +so this is the amount that i will have + + + align:start position:0% +so this is the amount that i will have +to pay you in today's dollars + + align:start position:0% +to pay you in today's dollars + + + align:start position:0% +to pay you in today's dollars +i need in order to be paying you 100 a + + align:start position:0% +i need in order to be paying you 100 a + + + align:start position:0% +i need in order to be paying you 100 a +year for ten years i need a total of + + align:start position:0% +year for ten years i need a total of + + + align:start position:0% +year for ten years i need a total of +this amount much amount of money now + + align:start position:0% +this amount much amount of money now + + + align:start position:0% +this amount much amount of money now +because each of these terms is the + + align:start position:0% +because each of these terms is the + + + align:start position:0% +because each of these terms is the +amount of money that the hundred dollars + + align:start position:0% +amount of money that the hundred dollars + + + align:start position:0% +amount of money that the hundred dollars +will be worth paid to you that many + + align:start position:0% +will be worth paid to you that many + + + align:start position:0% +will be worth paid to you that many +years out well look at this + + align:start position:0% +years out well look at this + + + align:start position:0% +years out well look at this +some if i factor out a hundred r + + align:start position:0% +some if i factor out a hundred r + + + align:start position:0% +some if i factor out a hundred r +i'm left with a hundred r times the + + align:start position:0% +i'm left with a hundred r times the + + + align:start position:0% +i'm left with a hundred r times the +geometric sum from one to r to the ninth + + align:start position:0% +geometric sum from one to r to the ninth + + + align:start position:0% +geometric sum from one to r to the ninth +where the base of the sum is r the + + align:start position:0% +where the base of the sum is r the + + + align:start position:0% +where the base of the sum is r the +factor is r well we have a nice formula + + align:start position:0% +factor is r well we have a nice formula + + + align:start position:0% +factor is r well we have a nice formula +for that + + align:start position:0% +for that + + + align:start position:0% +for that +it's simply 1 minus r to the 10th over 1 + + align:start position:0% +it's simply 1 minus r to the 10th over 1 + + + align:start position:0% +it's simply 1 minus r to the 10th over 1 +minus r + + align:start position:0% +minus r + + + align:start position:0% +minus r +and now plugging in r equals 1 over 1.03 + + align:start position:0% +and now plugging in r equals 1 over 1.03 + + + align:start position:0% +and now plugging in r equals 1 over 1.03 +i wind up with the conclusion that this + + align:start position:0% +i wind up with the conclusion that this + + + align:start position:0% +i wind up with the conclusion that this +annuity + + align:start position:0% +annuity + + + align:start position:0% +annuity +is worth + + align:start position:0% +is worth + + + align:start position:0% +is worth +dollars and 853.00 cents today + + align:start position:0% +dollars and 853.00 cents today + + + align:start position:0% +dollars and 853.00 cents today +my promise to pay you a thousand dollars + + align:start position:0% +my promise to pay you a thousand dollars + + + align:start position:0% +my promise to pay you a thousand dollars +but spread out over the next 11 years is + + align:start position:0% +but spread out over the next 11 years is + + + align:start position:0% +but spread out over the next 11 years is +worth + + align:start position:0% +worth + + + align:start position:0% +worth +853.2 cents today assuming that the bank + + align:start position:0% +853.2 cents today assuming that the bank + + + align:start position:0% +853.2 cents today assuming that the bank +rate is three percent a year + + align:start position:0% +rate is three percent a year + + + align:start position:0% +rate is three percent a year +and that's a typical case where um + + align:start position:0% +and that's a typical case where um + + + align:start position:0% +and that's a typical case where um +geometric series come up and you'll see + + align:start position:0% +geometric series come up and you'll see + + + align:start position:0% +geometric series come up and you'll see +other examples uh in problems just a + + align:start position:0% +other examples uh in problems just a + + + align:start position:0% +other examples uh in problems just a +quick thing to think about suppose that + + align:start position:0% +quick thing to think about suppose that + + + align:start position:0% +quick thing to think about suppose that +the bank rates uh rapidly increase + + align:start position:0% +the bank rates uh rapidly increase + + + align:start position:0% +the bank rates uh rapidly increase +unexpectedly increase the fed finally + + align:start position:0% +unexpectedly increase the fed finally + + + align:start position:0% +unexpectedly increase the fed finally +gets the economy moving and interest + + align:start position:0% +gets the economy moving and interest + + + align:start position:0% +gets the economy moving and interest +rates run up to five percent say + + align:start position:0% +rates run up to five percent say + + + align:start position:0% +rates run up to five percent say +what happens + + align:start position:0% +what happens + + + align:start position:0% +what happens +on this annuity you've already paid me + + align:start position:0% +on this annuity you've already paid me + + + align:start position:0% +on this annuity you've already paid me +the 853 and i've already committed to + + align:start position:0% +the 853 and i've already committed to + + + align:start position:0% +the 853 and i've already committed to +paying you 100 a year for the next 10 + + align:start position:0% +paying you 100 a year for the next 10 + + + align:start position:0% +paying you 100 a year for the next 10 +years uh starting in a year who comes + + align:start position:0% +years uh starting in a year who comes + + + align:start position:0% +years uh starting in a year who comes +out ahead if bank if + + align:start position:0% +out ahead if bank if + + + align:start position:0% +out ahead if bank if +uh bank rates increase you come out + + align:start position:0% +uh bank rates increase you come out + + + align:start position:0% +uh bank rates increase you come out +ahead the deal stays fair or i come out + + align:start position:0% +ahead the deal stays fair or i come out + + + align:start position:0% +ahead the deal stays fair or i come out +ahead and i'll close by letting you + + align:start position:0% +ahead and i'll close by letting you + + + align:start position:0% +ahead and i'll close by letting you +think about + + align:start position:0% +think about + + + align:start position:0% +think about +that question \ No newline at end of file diff --git a/ZQQiquqm7Ro.txt b/ZQQiquqm7Ro.txt new file mode 100644 index 0000000000000000000000000000000000000000..f2f974779d32ded03b05b4cb5f020494f734cd22 --- /dev/null +++ b/ZQQiquqm7Ro.txt @@ -0,0 +1,16939 @@ +align:start position:0% + +foreign + + align:start position:0% + + + + align:start position:0% + +So today we're talking about uh the + + align:start position:0% +So today we're talking about uh the + + + align:start position:0% +So today we're talking about uh the +reception of Einstein's work from 1905 + + align:start position:0% +reception of Einstein's work from 1905 + + + align:start position:0% +reception of Einstein's work from 1905 +on the electrodynamics moving body so + + align:start position:0% +on the electrodynamics moving body so + + + align:start position:0% +on the electrodynamics moving body so +we'll talk about the reception of what + + align:start position:0% +we'll talk about the reception of what + + + align:start position:0% +we'll talk about the reception of what +we have come to call the special theory + + align:start position:0% +we have come to call the special theory + + + align:start position:0% +we have come to call the special theory +of relativity + + align:start position:0% +of relativity + + + align:start position:0% +of relativity +so as a quick uh reminder we're gonna um + + align:start position:0% +so as a quick uh reminder we're gonna um + + + align:start position:0% +so as a quick uh reminder we're gonna um +sorry so excuse me the the class today + + align:start position:0% +sorry so excuse me the the class today + + + align:start position:0% +sorry so excuse me the the class today +has three main parts like they usually + + align:start position:0% +has three main parts like they usually + + + align:start position:0% +has three main parts like they usually +do we'll talk about some of the early + + align:start position:0% +do we'll talk about some of the early + + + align:start position:0% +do we'll talk about some of the early +reactions to Einstein himself and to + + align:start position:0% +reactions to Einstein himself and to + + + align:start position:0% +reactions to Einstein himself and to +this body of work and then we'll look at + + align:start position:0% +this body of work and then we'll look at + + + align:start position:0% +this body of work and then we'll look at +two specific examples of those reactions + + align:start position:0% +two specific examples of those reactions + + + align:start position:0% +two specific examples of those reactions +in a bit more detail get more of a sense + + align:start position:0% +in a bit more detail get more of a sense + + + align:start position:0% +in a bit more detail get more of a sense +of what ways where people could have + + align:start position:0% +of what ways where people could have + + + align:start position:0% +of what ways where people could have +engaging with Einstein's paper from 1905 + + align:start position:0% +engaging with Einstein's paper from 1905 + + + align:start position:0% +engaging with Einstein's paper from 1905 +what did they think it was really about + + align:start position:0% +what did they think it was really about + + + align:start position:0% +what did they think it was really about +what do they get excited about what do + + align:start position:0% +what do they get excited about what do + + + align:start position:0% +what do they get excited about what do +they ignore that otherwise seem to have + + align:start position:0% +they ignore that otherwise seem to have + + + align:start position:0% +they ignore that otherwise seem to have +been really important to Einstein + + align:start position:0% +been really important to Einstein + + + align:start position:0% +been really important to Einstein +himself so we're going to talk about not + + align:start position:0% +himself so we're going to talk about not + + + align:start position:0% +himself so we're going to talk about not +just did people read the paper and make + + align:start position:0% +just did people read the paper and make + + + align:start position:0% +just did people read the paper and make +use of it but in what specific ways how + + align:start position:0% +use of it but in what specific ways how + + + align:start position:0% +use of it but in what specific ways how +would they kind of creatively making + + align:start position:0% +would they kind of creatively making + + + align:start position:0% +would they kind of creatively making +this work uh relevant from where they + + align:start position:0% +this work uh relevant from where they + + + align:start position:0% +this work uh relevant from where they +sat intellectually and institutionally + + align:start position:0% +sat intellectually and institutionally + + + align:start position:0% +sat intellectually and institutionally +and we'll see that sometimes that + + align:start position:0% +and we'll see that sometimes that + + + align:start position:0% +and we'll see that sometimes that +diverged sometimes in dramatic ways from + + align:start position:0% +diverged sometimes in dramatic ways from + + + align:start position:0% +diverged sometimes in dramatic ways from +what Einstein himself thought was most + + align:start position:0% +what Einstein himself thought was most + + + align:start position:0% +what Einstein himself thought was most +relevant or most interesting or most + + align:start position:0% +relevant or most interesting or most + + + align:start position:0% +relevant or most interesting or most +important about his own work and that's + + align:start position:0% +important about his own work and that's + + + align:start position:0% +important about his own work and that's +a theme again we've seen already a few + + align:start position:0% +a theme again we've seen already a few + + + align:start position:0% +a theme again we've seen already a few +times so far in this class different + + align:start position:0% +times so far in this class different + + + align:start position:0% +times so far in this class different +people engaging with Maxwell's equations + + align:start position:0% +people engaging with Maxwell's equations + + + align:start position:0% +people engaging with Maxwell's equations +in different ways + + align:start position:0% +in different ways + + + align:start position:0% +in different ways +it's a theme that we'll see really + + align:start position:0% +it's a theme that we'll see really + + + align:start position:0% +it's a theme that we'll see really +throughout the entire semester and + + align:start position:0% +throughout the entire semester and + + + align:start position:0% +throughout the entire semester and +here's a class I like I this is pretty + + align:start position:0% +here's a class I like I this is pretty + + + align:start position:0% +here's a class I like I this is pretty +fun material because I think we get to + + align:start position:0% +fun material because I think we get to + + + align:start position:0% +fun material because I think we get to +really sit with some examples in some + + align:start position:0% +really sit with some examples in some + + + align:start position:0% +really sit with some examples in some +detail and really watch people kind of + + align:start position:0% +detail and really watch people kind of + + + align:start position:0% +detail and really watch people kind of +wrestle with what was a fairly new + + align:start position:0% +wrestle with what was a fairly new + + + align:start position:0% +wrestle with what was a fairly new +material Einstein's paper from 1905. + + align:start position:0% +material Einstein's paper from 1905. + + + align:start position:0% +material Einstein's paper from 1905. +so just a reminder where what we cover + + align:start position:0% +so just a reminder where what we cover + + + align:start position:0% +so just a reminder where what we cover +in our previous discussion just on + + align:start position:0% +in our previous discussion just on + + + align:start position:0% +in our previous discussion just on +Monday + + align:start position:0% +Monday + + + align:start position:0% +Monday +Einstein had many different kind of + + align:start position:0% +Einstein had many different kind of + + + align:start position:0% +Einstein had many different kind of +threads that he brought together in this + + align:start position:0% +threads that he brought together in this + + + align:start position:0% +threads that he brought together in this +paper from 1905 entitled on the + + align:start position:0% +paper from 1905 entitled on the + + + align:start position:0% +paper from 1905 entitled on the +electronomics of moving bodies he was a + + align:start position:0% +electronomics of moving bodies he was a + + + align:start position:0% +electronomics of moving bodies he was a +recent college graduate he was working + + align:start position:0% +recent college graduate he was working + + + align:start position:0% +recent college graduate he was working +kind of off hours on his PhD thesis he + + align:start position:0% +kind of off hours on his PhD thesis he + + + align:start position:0% +kind of off hours on his PhD thesis he +had a full-time day job working at the + + align:start position:0% +had a full-time day job working at the + + + align:start position:0% +had a full-time day job working at the +patent office in Barron Switzerland at + + align:start position:0% +patent office in Barron Switzerland at + + + align:start position:0% +patent office in Barron Switzerland at +the lowest level entry-level job of + + align:start position:0% +the lowest level entry-level job of + + + align:start position:0% +the lowest level entry-level job of +patent office with third class and in + + align:start position:0% +patent office with third class and in + + + align:start position:0% +patent office with third class and in +the evenings he would hang out with his + + align:start position:0% +the evenings he would hang out with his + + + align:start position:0% +the evenings he would hang out with his +friends like um Laurie Sullivan and + + align:start position:0% +friends like um Laurie Sullivan and + + + align:start position:0% +friends like um Laurie Sullivan and +comrade had peaked and another friend uh + + align:start position:0% +comrade had peaked and another friend uh + + + align:start position:0% +comrade had peaked and another friend uh +Michelangelo besso and a small circle + + align:start position:0% +Michelangelo besso and a small circle + + + align:start position:0% +Michelangelo besso and a small circle +and they would read physics and + + align:start position:0% +and they would read physics and + + + align:start position:0% +and they would read physics and +philosophy together and they call + + align:start position:0% +philosophy together and they call + + + align:start position:0% +philosophy together and they call +themselves The Olympia Academy even + + align:start position:0% +themselves The Olympia Academy even + + + align:start position:0% +themselves The Olympia Academy even +though it was really just three recent + + align:start position:0% +though it was really just three recent + + + align:start position:0% +though it was really just three recent +graduates drinking beer in the in the + + align:start position:0% +graduates drinking beer in the in the + + + align:start position:0% +graduates drinking beer in the in the +pub talking about things like the work + + align:start position:0% +pub talking about things like the work + + + align:start position:0% +pub talking about things like the work +of Aaron's mock not a bad way to spend + + align:start position:0% +of Aaron's mock not a bad way to spend + + + align:start position:0% +of Aaron's mock not a bad way to spend +your time after college + + align:start position:0% +your time after college + + + align:start position:0% +your time after college +so one of the people that we're really + + align:start position:0% +so one of the people that we're really + + + align:start position:0% +so one of the people that we're really +interested in was Aaron's Mock and again + + align:start position:0% +interested in was Aaron's Mock and again + + + align:start position:0% +interested in was Aaron's Mock and again +we have this great reading um that was + + align:start position:0% +we have this great reading um that was + + + align:start position:0% +we have this great reading um that was +on the + + align:start position:0% +on the + + + align:start position:0% +on the +um the canvas site I think designed for + + align:start position:0% +um the canvas site I think designed for + + + align:start position:0% +um the canvas site I think designed for +this for Mondays this past Monday's + + align:start position:0% +this for Mondays this past Monday's + + + align:start position:0% +this for Mondays this past Monday's +class by our own Amanda gafter one of + + align:start position:0% +class by our own Amanda gafter one of + + + align:start position:0% +class by our own Amanda gafter one of +our Tas who helps us really even more + + align:start position:0% +our Tas who helps us really even more + + + align:start position:0% +our Tas who helps us really even more +understand what was mock all about what + + align:start position:0% +understand what was mock all about what + + + align:start position:0% +understand what was mock all about what +did Einstein take from Mock's work and + + align:start position:0% +did Einstein take from Mock's work and + + + align:start position:0% +did Einstein take from Mock's work and +so I encourage you to go back and reread + + align:start position:0% +so I encourage you to go back and reread + + + align:start position:0% +so I encourage you to go back and reread +Amanda's piece as well + + align:start position:0% +Amanda's piece as well + + + align:start position:0% +Amanda's piece as well +so Aaron's mock was his Viennese + + align:start position:0% +so Aaron's mock was his Viennese + + + align:start position:0% +so Aaron's mock was his Viennese +polymath who introduced this philosophy + + align:start position:0% +polymath who introduced this philosophy + + + align:start position:0% +polymath who introduced this philosophy +of science in the later years of the + + align:start position:0% +of science in the later years of the + + + align:start position:0% +of science in the later years of the +19th century uh really during kind of + + align:start position:0% +19th century uh really during kind of + + + align:start position:0% +19th century uh really during kind of +Einstein's childhood + + align:start position:0% +Einstein's childhood + + + align:start position:0% +Einstein's childhood +they came to be called positivism as far + + align:start position:0% +they came to be called positivism as far + + + align:start position:0% +they came to be called positivism as far +as ants Mark was concerned the only the + + align:start position:0% +as ants Mark was concerned the only the + + + align:start position:0% +as ants Mark was concerned the only the +best way to make progress scientifically + + align:start position:0% +best way to make progress scientifically + + + align:start position:0% +best way to make progress scientifically +was to focus on objects of positive + + align:start position:0% +was to focus on objects of positive + + + align:start position:0% +was to focus on objects of positive +experience that's where the positivism + + align:start position:0% +experience that's where the positivism + + + align:start position:0% +experience that's where the positivism +comes from things we could really + + align:start position:0% +comes from things we could really + + + align:start position:0% +comes from things we could really +concretely observe or measure and not + + align:start position:0% +concretely observe or measure and not + + + align:start position:0% +concretely observe or measure and not +focus on things that could never even in + + align:start position:0% +focus on things that could never even in + + + align:start position:0% +focus on things that could never even in +principle be subject to these kind of + + align:start position:0% +principle be subject to these kind of + + + align:start position:0% +principle be subject to these kind of +empirical inputs so we have this + + align:start position:0% +empirical inputs so we have this + + + align:start position:0% +empirical inputs so we have this +extensive often very biting very very uh + + align:start position:0% +extensive often very biting very very uh + + + align:start position:0% +extensive often very biting very very uh +very you know uh + + align:start position:0% +very you know uh + + + align:start position:0% +very you know uh +significant critique of Newtonian + + align:start position:0% +significant critique of Newtonian + + + align:start position:0% +significant critique of Newtonian +physics which Mark was as far as Mark + + align:start position:0% +physics which Mark was as far as Mark + + + align:start position:0% +physics which Mark was as far as Mark +was concerned was like riddled with + + align:start position:0% +was concerned was like riddled with + + + align:start position:0% +was concerned was like riddled with +these things that could never ever + + align:start position:0% +these things that could never ever + + + align:start position:0% +these things that could never ever +become objects of positive experience + + align:start position:0% +become objects of positive experience + + + align:start position:0% +become objects of positive experience +and that really was very very inspiring + + align:start position:0% +and that really was very very inspiring + + + align:start position:0% +and that really was very very inspiring +for Young Einstein and his circle of + + align:start position:0% +for Young Einstein and his circle of + + + align:start position:0% +for Young Einstein and his circle of +friends so one of the lessons that + + align:start position:0% +friends so one of the lessons that + + + align:start position:0% +friends so one of the lessons that +Einstein took from that among several + + align:start position:0% +Einstein took from that among several + + + align:start position:0% +Einstein took from that among several +in these years leading up to around 1905 + + align:start position:0% +in these years leading up to around 1905 + + + align:start position:0% +in these years leading up to around 1905 +was that it would make sense to focus on + + align:start position:0% +was that it would make sense to focus on + + + align:start position:0% +was that it would make sense to focus on +kinematics the the motion of objects + + align:start position:0% +kinematics the the motion of objects + + + align:start position:0% +kinematics the the motion of objects +through space and time things we could + + align:start position:0% +through space and time things we could + + + align:start position:0% +through space and time things we could +at least in principle really measure and + + align:start position:0% +at least in principle really measure and + + + align:start position:0% +at least in principle really measure and +observe rather than starting our inquiry + + align:start position:0% +observe rather than starting our inquiry + + + align:start position:0% +observe rather than starting our inquiry +with Dynamics the study of forces that + + align:start position:0% +with Dynamics the study of forces that + + + align:start position:0% +with Dynamics the study of forces that +was really turning on its head would + + align:start position:0% +was really turning on its head would + + + align:start position:0% +was really turning on its head would +have become quite a standard way to + + align:start position:0% +have become quite a standard way to + + + align:start position:0% +have become quite a standard way to +approach topics like electrodynamics we + + align:start position:0% +approach topics like electrodynamics we + + + align:start position:0% +approach topics like electrodynamics we +saw when Hendrick Lorenz considered + + align:start position:0% +saw when Hendrick Lorenz considered + + + align:start position:0% +saw when Hendrick Lorenz considered +electronomics he would start with the + + align:start position:0% +electronomics he would start with the + + + align:start position:0% +electronomics he would start with the +forces exerted by The Ether on objects + + align:start position:0% +forces exerted by The Ether on objects + + + align:start position:0% +forces exerted by The Ether on objects +and so on Einstein said let's start with + + align:start position:0% +and so on Einstein said let's start with + + + align:start position:0% +and so on Einstein said let's start with +kinematics first it was that kind of + + align:start position:0% +kinematics first it was that kind of + + + align:start position:0% +kinematics first it was that kind of +thinking that led him to postulate these + + align:start position:0% +thinking that led him to postulate these + + + align:start position:0% +thinking that led him to postulate these +opening postulates in his 1905 paper + + align:start position:0% +opening postulates in his 1905 paper + + + align:start position:0% +opening postulates in his 1905 paper +which hopefully is now quite familiar to + + align:start position:0% +which hopefully is now quite familiar to + + + align:start position:0% +which hopefully is now quite familiar to +you in these opening few pages this is + + align:start position:0% +you in these opening few pages this is + + + align:start position:0% +you in these opening few pages this is +the subject for your first paper + + align:start position:0% +the subject for your first paper + + + align:start position:0% +the subject for your first paper +assignment + + align:start position:0% +assignment + + + align:start position:0% +assignment +and to to paraphrase these two passwords + + align:start position:0% +and to to paraphrase these two passwords + + + align:start position:0% +and to to paraphrase these two passwords +that Einstein elevates in those opening + + align:start position:0% +that Einstein elevates in those opening + + + align:start position:0% +that Einstein elevates in those opening +paragraphs the first is a kind of + + align:start position:0% +paragraphs the first is a kind of + + + align:start position:0% +paragraphs the first is a kind of +extension or generalization of an idea + + align:start position:0% +extension or generalization of an idea + + + align:start position:0% +extension or generalization of an idea +that was actually centuries old by this + + align:start position:0% +that was actually centuries old by this + + + align:start position:0% +that was actually centuries old by this +point he was really building on + + align:start position:0% +point he was really building on + + + align:start position:0% +point he was really building on +Galileo's work and Einstein says not + + align:start position:0% +Galileo's work and Einstein says not + + + align:start position:0% +Galileo's work and Einstein says not +only should the laws of mechanics be + + align:start position:0% +only should the laws of mechanics be + + + align:start position:0% +only should the laws of mechanics be +valid for any Observer who's moving at a + + align:start position:0% +valid for any Observer who's moving at a + + + align:start position:0% +valid for any Observer who's moving at a +constant speed as long as they're not + + align:start position:0% +constant speed as long as they're not + + + align:start position:0% +constant speed as long as they're not +speeding up or slowing down they're not + + align:start position:0% +speeding up or slowing down they're not + + + align:start position:0% +speeding up or slowing down they're not +accelerating then all the laws and + + align:start position:0% +accelerating then all the laws and + + + align:start position:0% +accelerating then all the laws and +mechanics or ballistics of you know a a + + align:start position:0% +mechanics or ballistics of you know a a + + + align:start position:0% +mechanics or ballistics of you know a a +ball you might toss and play catch all + + align:start position:0% +ball you might toss and play catch all + + + align:start position:0% +ball you might toss and play catch all +those laws are valid whether you're on a + + align:start position:0% +those laws are valid whether you're on a + + + align:start position:0% +those laws are valid whether you're on a +boat moving at a constant speed down the + + align:start position:0% +boat moving at a constant speed down the + + + align:start position:0% +boat moving at a constant speed down the +river or standing still on the on the + + align:start position:0% +river or standing still on the on the + + + align:start position:0% +river or standing still on the on the +shore Einstein says that's true that + + align:start position:0% +shore Einstein says that's true that + + + align:start position:0% +shore Einstein says that's true that +should be true for all of physics for + + align:start position:0% +should be true for all of physics for + + + align:start position:0% +should be true for all of physics for +electricity for magnesium for optics for + + align:start position:0% +electricity for magnesium for optics for + + + align:start position:0% +electricity for magnesium for optics for +thermodynamics so part one is kind of + + align:start position:0% +thermodynamics so part one is kind of + + + align:start position:0% +thermodynamics so part one is kind of +elevating or generalizing what was + + align:start position:0% +elevating or generalizing what was + + + align:start position:0% +elevating or generalizing what was +already a fairly familiar notion to many + + align:start position:0% +already a fairly familiar notion to many + + + align:start position:0% +already a fairly familiar notion to many +many physicists and part two at least at + + align:start position:0% +many physicists and part two at least at + + + align:start position:0% +many physicists and part two at least at +first he says looks apparently + + align:start position:0% +first he says looks apparently + + + align:start position:0% +first he says looks apparently +irreconcilable with the first the second + + align:start position:0% +irreconcilable with the first the second + + + align:start position:0% +irreconcilable with the first the second +postulate according to Einstein is that + + align:start position:0% +postulate according to Einstein is that + + + align:start position:0% +postulate according to Einstein is that +the speed of light C is a con constant + + align:start position:0% +the speed of light C is a con constant + + + align:start position:0% +the speed of light C is a con constant +independent of the motion of the source + + align:start position:0% +independent of the motion of the source + + + align:start position:0% +independent of the motion of the source +and he had we now know he came to that + + align:start position:0% +and he had we now know he came to that + + + align:start position:0% +and he had we now know he came to that +in his own kind of private thinking or + + align:start position:0% +in his own kind of private thinking or + + + align:start position:0% +in his own kind of private thinking or +in talking with a small circle of + + align:start position:0% +in talking with a small circle of + + + align:start position:0% +in talking with a small circle of +friends by a series of these thought + + align:start position:0% +friends by a series of these thought + + + align:start position:0% +friends by a series of these thought +experiments like what would it be like + + align:start position:0% +experiments like what would it be like + + + align:start position:0% +experiments like what would it be like +if you could catch up to a light wave + + align:start position:0% +if you could catch up to a light wave + + + align:start position:0% +if you could catch up to a light wave +like this Surfer riding at the same + + align:start position:0% +like this Surfer riding at the same + + + align:start position:0% +like this Surfer riding at the same +speed as the ocean wave you would see + + align:start position:0% +speed as the ocean wave you would see + + + align:start position:0% +speed as the ocean wave you would see +this frozen field configuration which + + align:start position:0% +this frozen field configuration which + + + align:start position:0% +this frozen field configuration which +Einstein was convinced could never + + align:start position:0% +Einstein was convinced could never + + + align:start position:0% +Einstein was convinced could never +really happen so how do you make sure no + + align:start position:0% +really happen so how do you make sure no + + + align:start position:0% +really happen so how do you make sure no +one gets caught in that absurdity make + + align:start position:0% +one gets caught in that absurdity make + + + align:start position:0% +one gets caught in that absurdity make +sure no one can ever catch up to a light + + align:start position:0% +sure no one can ever catch up to a light + + + align:start position:0% +sure no one can ever catch up to a light +wave who have lights always going to + + align:start position:0% +wave who have lights always going to + + + align:start position:0% +wave who have lights always going to +travel at a fixed speed no matter how + + align:start position:0% +travel at a fixed speed no matter how + + + align:start position:0% +travel at a fixed speed no matter how +fast you're chasing after it if I'm on a + + align:start position:0% +fast you're chasing after it if I'm on a + + + align:start position:0% +fast you're chasing after it if I'm on a +supersonic Jet Plane + + align:start position:0% +supersonic Jet Plane + + + align:start position:0% +supersonic Jet Plane +I'm still going to see the light wave + + align:start position:0% +I'm still going to see the light wave + + + align:start position:0% +I'm still going to see the light wave +travel past me at this fixed speed of + + align:start position:0% +travel past me at this fixed speed of + + + align:start position:0% +travel past me at this fixed speed of +light that no matter what you know fancy + + align:start position:0% +light that no matter what you know fancy + + + align:start position:0% +light that no matter what you know fancy +engines I soup up on my on my means of + + align:start position:0% +engines I soup up on my on my means of + + + align:start position:0% +engines I soup up on my on my means of +transportation I will never ever be like + + align:start position:0% +transportation I will never ever be like + + + align:start position:0% +transportation I will never ever be like +this Surfer I will never catch up to and + + align:start position:0% +this Surfer I will never catch up to and + + + align:start position:0% +this Surfer I will never catch up to and +move at the same speed as that light + + align:start position:0% +move at the same speed as that light + + + align:start position:0% +move at the same speed as that light +wave and that was Einstein considered + + align:start position:0% +wave and that was Einstein considered + + + align:start position:0% +wave and that was Einstein considered +really Central as a posture he doesn't + + align:start position:0% +really Central as a posture he doesn't + + + align:start position:0% +really Central as a posture he doesn't +prove it he doesn't even really motivate + + align:start position:0% +prove it he doesn't even really motivate + + + align:start position:0% +prove it he doesn't even really motivate +it in this paper very strongly he + + align:start position:0% +it in this paper very strongly he + + + align:start position:0% +it in this paper very strongly he +elevates it to an assumption and sees + + align:start position:0% +elevates it to an assumption and sees + + + align:start position:0% +elevates it to an assumption and sees +what will follow + + align:start position:0% +what will follow + + + align:start position:0% +what will follow +and then it's from those starting + + align:start position:0% +and then it's from those starting + + + align:start position:0% +and then it's from those starting +postulates where again just in the + + align:start position:0% +postulates where again just in the + + + align:start position:0% +postulates where again just in the +opening few pages of this article where + + align:start position:0% +opening few pages of this article where + + + align:start position:0% +opening few pages of this article where +he comes to what he calls the relativity + + align:start position:0% +he comes to what he calls the relativity + + + align:start position:0% +he comes to what he calls the relativity +of simultaneity that events that that we + + align:start position:0% +of simultaneity that events that that we + + + align:start position:0% +of simultaneity that events that that we +might consider to have happened at the + + align:start position:0% +might consider to have happened at the + + + align:start position:0% +might consider to have happened at the +same time to have been simultaneous will + + align:start position:0% +same time to have been simultaneous will + + + align:start position:0% +same time to have been simultaneous will +not appear to have been simultaneous to + + align:start position:0% +not appear to have been simultaneous to + + + align:start position:0% +not appear to have been simultaneous to +emotion to an observer who is otherwise + + align:start position:0% +emotion to an observer who is otherwise + + + align:start position:0% +emotion to an observer who is otherwise +fully legitimate meaning all the laws of + + align:start position:0% +fully legitimate meaning all the laws of + + + align:start position:0% +fully legitimate meaning all the laws of +physics should hold perfectly valid for + + align:start position:0% +physics should hold perfectly valid for + + + align:start position:0% +physics should hold perfectly valid for +her she just happens to be moving at + + align:start position:0% +her she just happens to be moving at + + + align:start position:0% +her she just happens to be moving at +some constant speed with respect to us + + align:start position:0% +some constant speed with respect to us + + + align:start position:0% +some constant speed with respect to us +we will disagree on what counts as + + align:start position:0% +we will disagree on what counts as + + + align:start position:0% +we will disagree on what counts as +simultaneous + + align:start position:0% +simultaneous + + + align:start position:0% +simultaneous +and from that from that Einstein was + + align:start position:0% +and from that from that Einstein was + + + align:start position:0% +and from that from that Einstein was +convinced would lead uh these other + + align:start position:0% +convinced would lead uh these other + + + align:start position:0% +convinced would lead uh these other +phenomena like length contraction and + + align:start position:0% +phenomena like length contraction and + + + align:start position:0% +phenomena like length contraction and +time dilation not because of forces + + align:start position:0% +time dilation not because of forces + + + align:start position:0% +time dilation not because of forces +exerted by an ether but because we + + align:start position:0% +exerted by an ether but because we + + + align:start position:0% +exerted by an ether but because we +disagree on when to implement our + + align:start position:0% +disagree on when to implement our + + + align:start position:0% +disagree on when to implement our +measurements because we disagree on what + + align:start position:0% +measurements because we disagree on what + + + align:start position:0% +measurements because we disagree on what +counts as simultaneous events and that + + align:start position:0% +counts as simultaneous events and that + + + align:start position:0% +counts as simultaneous events and that +comes for him come from starting with + + align:start position:0% +comes for him come from starting with + + + align:start position:0% +comes for him come from starting with +kinematics not Dynamics and again that's + + align:start position:0% +kinematics not Dynamics and again that's + + + align:start position:0% +kinematics not Dynamics and again that's +the the form of reasoning that Einstein + + align:start position:0% +the the form of reasoning that Einstein + + + align:start position:0% +the the form of reasoning that Einstein +puts in those uh those opening pages of + + align:start position:0% +puts in those uh those opening pages of + + + align:start position:0% +puts in those uh those opening pages of +his paper from 1905. okay + + align:start position:0% +his paper from 1905. okay + + + align:start position:0% +his paper from 1905. okay +so what were the early reactions to that + + align:start position:0% +so what were the early reactions to that + + + align:start position:0% +so what were the early reactions to that +body of work remember it was published + + align:start position:0% +body of work remember it was published + + + align:start position:0% +body of work remember it was published +in really the leading or certainly one + + align:start position:0% +in really the leading or certainly one + + + align:start position:0% +in really the leading or certainly one +of the leading journals in Western + + align:start position:0% +of the leading journals in Western + + + align:start position:0% +of the leading journals in Western +Europe for professional physicists it + + align:start position:0% +Europe for professional physicists it + + + align:start position:0% +Europe for professional physicists it +was it was a perfect uh venue to try to + + align:start position:0% +was it was a perfect uh venue to try to + + + align:start position:0% +was it was a perfect uh venue to try to +get some attention and yet we now know + + align:start position:0% +get some attention and yet we now know + + + align:start position:0% +get some attention and yet we now know +historically the first reaction was no + + align:start position:0% +historically the first reaction was no + + + align:start position:0% +historically the first reaction was no +reaction at all the kind of Baseline + + align:start position:0% +reaction at all the kind of Baseline + + + align:start position:0% +reaction at all the kind of Baseline +summary for today's class is no one paid + + align:start position:0% +summary for today's class is no one paid + + + align:start position:0% +summary for today's class is no one paid +attention to very few people paid + + align:start position:0% +attention to very few people paid + + + align:start position:0% +attention to very few people paid +attention we now know Einstein's name we + + align:start position:0% +attention we now know Einstein's name we + + + align:start position:0% +attention we now know Einstein's name we +might own Einstein's swag you know + + align:start position:0% +might own Einstein's swag you know + + + align:start position:0% +might own Einstein's swag you know +t-shirts and coffee mugs bumper stickers + + align:start position:0% +t-shirts and coffee mugs bumper stickers + + + align:start position:0% +t-shirts and coffee mugs bumper stickers +uh that simply was not the case in 1905 + + align:start position:0% +uh that simply was not the case in 1905 + + + align:start position:0% +uh that simply was not the case in 1905 +or 1906 or 1907 it really was quite a + + align:start position:0% +or 1906 or 1907 it really was quite a + + + align:start position:0% +or 1906 or 1907 it really was quite a +delay so at the time Einstein as we saw + + align:start position:0% +delay so at the time Einstein as we saw + + + align:start position:0% +delay so at the time Einstein as we saw +was this really little-known patent + + align:start position:0% +was this really little-known patent + + + align:start position:0% +was this really little-known patent +clerk he was not employed as a research + + align:start position:0% +clerk he was not employed as a research + + + align:start position:0% +clerk he was not employed as a research +scientist he was not teaching in a + + align:start position:0% +scientist he was not teaching in a + + + align:start position:0% +scientist he was not teaching in a +university that that had been his + + align:start position:0% +university that that had been his + + + align:start position:0% +university that that had been his +ambition he just was not able to get + + align:start position:0% +ambition he just was not able to get + + + align:start position:0% +ambition he just was not able to get +that kind of job at first + + align:start position:0% +that kind of job at first + + + align:start position:0% +that kind of job at first +he was publishing before then perfectly + + align:start position:0% +he was publishing before then perfectly + + + align:start position:0% +he was publishing before then perfectly +adequate not very special articles on + + align:start position:0% +adequate not very special articles on + + + align:start position:0% +adequate not very special articles on +other topics in the main Journal he was + + align:start position:0% +other topics in the main Journal he was + + + align:start position:0% +other topics in the main Journal he was +building up a kind of portfolio of + + align:start position:0% +building up a kind of portfolio of + + + align:start position:0% +building up a kind of portfolio of +perfectly competent not very + + align:start position:0% +perfectly competent not very + + + align:start position:0% +perfectly competent not very +earth-shattering work so no one was like + + align:start position:0% +earth-shattering work so no one was like + + + align:start position:0% +earth-shattering work so no one was like +hanging on you know waiting at their + + align:start position:0% +hanging on you know waiting at their + + + align:start position:0% +hanging on you know waiting at their +mailbox to get the latest issue of the + + align:start position:0% +mailbox to get the latest issue of the + + + align:start position:0% +mailbox to get the latest issue of the +journal to see what Einstein had done + + align:start position:0% +journal to see what Einstein had done + + + align:start position:0% +journal to see what Einstein had done +lately very few people noticed anything + + align:start position:0% +lately very few people noticed anything + + + align:start position:0% +lately very few people noticed anything +at all + + align:start position:0% +at all + + + align:start position:0% +at all +so what I this next point I I is one of + + align:start position:0% +so what I this next point I I is one of + + + align:start position:0% +so what I this next point I I is one of +my favorites not only did Einstein still + + align:start position:0% +my favorites not only did Einstein still + + + align:start position:0% +my favorites not only did Einstein still +not get the kind of job he had most + + align:start position:0% +not get the kind of job he had most + + + align:start position:0% +not get the kind of job he had most +wanted an academic position he didn't + + align:start position:0% +wanted an academic position he didn't + + + align:start position:0% +wanted an academic position he didn't +even get a raise or promotion at his + + align:start position:0% +even get a raise or promotion at his + + + align:start position:0% +even get a raise or promotion at his +current job he was he remained a patent + + align:start position:0% +current job he was he remained a patent + + + align:start position:0% +current job he was he remained a patent +clerk third class even after publishing + + align:start position:0% +clerk third class even after publishing + + + align:start position:0% +clerk third class even after publishing +all of these articles even in the space + + align:start position:0% +all of these articles even in the space + + + align:start position:0% +all of these articles even in the space +of just one year within the leading + + align:start position:0% +of just one year within the leading + + + align:start position:0% +of just one year within the leading +physics journal not just the one we've + + align:start position:0% +physics journal not just the one we've + + + align:start position:0% +physics journal not just the one we've +looked at so far even others will look + + align:start position:0% +looked at so far even others will look + + + align:start position:0% +looked at so far even others will look +at soon he didn't even become patent + + align:start position:0% +at soon he didn't even become patent + + + align:start position:0% +at soon he didn't even become patent +Clerk's second class this was really + + align:start position:0% +Clerk's second class this was really + + + align:start position:0% +Clerk's second class this was really +really a complete you know shattering + + align:start position:0% +really a complete you know shattering + + + align:start position:0% +really a complete you know shattering +silence + + align:start position:0% +silence + + + align:start position:0% +silence +in response to his work so one of his + + align:start position:0% +in response to his work so one of his + + + align:start position:0% +in response to his work so one of his +close friends an exact contemporary of + + align:start position:0% +close friends an exact contemporary of + + + align:start position:0% +close friends an exact contemporary of +his max funlawa whom he happened to me + + align:start position:0% +his max funlawa whom he happened to me + + + align:start position:0% +his max funlawa whom he happened to me +uh who was following a more traditional + + align:start position:0% +uh who was following a more traditional + + + align:start position:0% +uh who was following a more traditional +uh physics research and academic career + + align:start position:0% +uh physics research and academic career + + + align:start position:0% +uh physics research and academic career +so now he was the same age as Einstein + + align:start position:0% +so now he was the same age as Einstein + + + align:start position:0% +so now he was the same age as Einstein +but was making advances of the sore nice + + align:start position:0% +but was making advances of the sore nice + + + align:start position:0% +but was making advances of the sore nice +I had hoped to make but it was not yet + + align:start position:0% +I had hoped to make but it was not yet + + + align:start position:0% +I had hoped to make but it was not yet +making for now what did his PhD quickly + + align:start position:0% +making for now what did his PhD quickly + + + align:start position:0% +making for now what did his PhD quickly +he got a very prestigious post-doctoral + + align:start position:0% +he got a very prestigious post-doctoral + + + align:start position:0% +he got a very prestigious post-doctoral +position he was soon teaching at a + + align:start position:0% +position he was soon teaching at a + + + align:start position:0% +position he was soon teaching at a +central uh Research Institute funlawy + + align:start position:0% +central uh Research Institute funlawy + + + align:start position:0% +central uh Research Institute funlawy +had befriended Einstein they would talk + + align:start position:0% +had befriended Einstein they would talk + + + align:start position:0% +had befriended Einstein they would talk +and because of this kind of direct + + align:start position:0% +and because of this kind of direct + + + align:start position:0% +and because of this kind of direct +connection Max funlawy and a very small + + align:start position:0% +connection Max funlawy and a very small + + + align:start position:0% +connection Max funlawy and a very small +number of others began trying to get a + + align:start position:0% +number of others began trying to get a + + + align:start position:0% +number of others began trying to get a +little more attention to Einstein's work + + align:start position:0% +little more attention to Einstein's work + + + align:start position:0% +little more attention to Einstein's work +on on what we would Now call special + + align:start position:0% +on on what we would Now call special + + + align:start position:0% +on on what we would Now call special +relativity so for example + + align:start position:0% +relativity so for example + + + align:start position:0% +relativity so for example +from his sort of better established uh + + align:start position:0% +from his sort of better established uh + + + align:start position:0% +from his sort of better established uh +academic position for now I wrote a + + align:start position:0% +academic position for now I wrote a + + + align:start position:0% +academic position for now I wrote a +review article that people did pay + + align:start position:0% +review article that people did pay + + + align:start position:0% +review article that people did pay +attention to he was kind of seen as a + + align:start position:0% +attention to he was kind of seen as a + + + align:start position:0% +attention to he was kind of seen as a +rising person to follow he wrote an + + align:start position:0% +rising person to follow he wrote an + + + align:start position:0% +rising person to follow he wrote an +article fully four years later in 1909 + + align:start position:0% +article fully four years later in 1909 + + + align:start position:0% +article fully four years later in 1909 +which helped to bring Einstein's work to + + align:start position:0% +which helped to bring Einstein's work to + + + align:start position:0% +which helped to bring Einstein's work to +others attention Isis work and that work + + align:start position:0% +others attention Isis work and that work + + + align:start position:0% +others attention Isis work and that work +of others as well so a few years later + + align:start position:0% +of others as well so a few years later + + + align:start position:0% +of others as well so a few years later +um some more people began to pay + + align:start position:0% +um some more people began to pay + + + align:start position:0% +um some more people began to pay +attention not because they were + + align:start position:0% +attention not because they were + + + align:start position:0% +attention not because they were +following Einstein per se but a little + + align:start position:0% +following Einstein per se but a little + + + align:start position:0% +following Einstein per se but a little +bit of a kind of percolation starts + + align:start position:0% +bit of a kind of percolation starts + + + align:start position:0% +bit of a kind of percolation starts +so reaction one is really no reaction at + + align:start position:0% +so reaction one is really no reaction at + + + align:start position:0% +so reaction one is really no reaction at +all the second reaction didn't make + + align:start position:0% +all the second reaction didn't make + + + align:start position:0% +all the second reaction didn't make +Einstein much happier so when people did + + align:start position:0% +Einstein much happier so when people did + + + align:start position:0% +Einstein much happier so when people did +notice the work the minority the + + align:start position:0% +notice the work the minority the + + + align:start position:0% +notice the work the minority the +exceptions to that rule who paid any + + align:start position:0% +exceptions to that rule who paid any + + + align:start position:0% +exceptions to that rule who paid any +attention at all they tended to read + + align:start position:0% +attention at all they tended to read + + + align:start position:0% +attention at all they tended to read +Einstein's paper the one that we're all + + align:start position:0% +Einstein's paper the one that we're all + + + align:start position:0% +Einstein's paper the one that we're all +immersed in now as kind of a clever + + align:start position:0% +immersed in now as kind of a clever + + + align:start position:0% +immersed in now as kind of a clever +rederivation of what was by then kind of + + align:start position:0% +rederivation of what was by then kind of + + + align:start position:0% +rederivation of what was by then kind of +old news they saw this as a really kind + + align:start position:0% +old news they saw this as a really kind + + + align:start position:0% +old news they saw this as a really kind +of smart way to get back to the results + + align:start position:0% +of smart way to get back to the results + + + align:start position:0% +of smart way to get back to the results +that leading physicists like Hedrick + + align:start position:0% +that leading physicists like Hedrick + + + align:start position:0% +that leading physicists like Hedrick +Lorenz and Henri pankarai in Paris and + + align:start position:0% +Lorenz and Henri pankarai in Paris and + + + align:start position:0% +Lorenz and Henri pankarai in Paris and +others had been fighting for a decade + + align:start position:0% +others had been fighting for a decade + + + align:start position:0% +others had been fighting for a decade +since the 1890s remember we even we saw + + align:start position:0% +since the 1890s remember we even we saw + + + align:start position:0% +since the 1890s remember we even we saw +this in our own class discussions a few + + align:start position:0% +this in our own class discussions a few + + + align:start position:0% +this in our own class discussions a few +sessions ago + + align:start position:0% +sessions ago + + + align:start position:0% +sessions ago +Hendrick Lorenz had already published on + + align:start position:0% +Hendrick Lorenz had already published on + + + align:start position:0% +Hendrick Lorenz had already published on +length contraction he was directly + + align:start position:0% +length contraction he was directly + + + align:start position:0% +length contraction he was directly +responding to the Michaelson model + + align:start position:0% +responding to the Michaelson model + + + align:start position:0% +responding to the Michaelson model +experiment in Lorenzo's case he hadn't + + align:start position:0% +experiment in Lorenzo's case he hadn't + + + align:start position:0% +experiment in Lorenzo's case he hadn't +only argued about there should be a + + align:start position:0% +only argued about there should be a + + + align:start position:0% +only argued about there should be a +contraction he had derived + + align:start position:0% +contraction he had derived + + + align:start position:0% +contraction he had derived +quantitatively an expression involving + + align:start position:0% +quantitatively an expression involving + + + align:start position:0% +quantitatively an expression involving +this Factor gamma that we've already + + align:start position:0% +this Factor gamma that we've already + + + align:start position:0% +this Factor gamma that we've already +seen many times one over the square root + + align:start position:0% +seen many times one over the square root + + + align:start position:0% +seen many times one over the square root +of one minus V over c squared that was + + align:start position:0% +of one minus V over c squared that was + + + align:start position:0% +of one minus V over c squared that was +the exact same quantitative result to + + align:start position:0% +the exact same quantitative result to + + + align:start position:0% +the exact same quantitative result to +which Einstein had arrived by very + + align:start position:0% +which Einstein had arrived by very + + + align:start position:0% +which Einstein had arrived by very +different forms of reasoning lorentz was + + align:start position:0% +different forms of reasoning lorentz was + + + align:start position:0% +different forms of reasoning lorentz was +a very senior very established very + + align:start position:0% +a very senior very established very + + + align:start position:0% +a very senior very established very +productive mathematical physicist people + + align:start position:0% +productive mathematical physicist people + + + align:start position:0% +productive mathematical physicist people +really did want to see what was + + align:start position:0% +really did want to see what was + + + align:start position:0% +really did want to see what was +Lorenzo's latest work they really would + + align:start position:0% +Lorenzo's latest work they really would + + + align:start position:0% +Lorenzo's latest work they really would +you know hang on his latest articles so + + align:start position:0% +you know hang on his latest articles so + + + align:start position:0% +you know hang on his latest articles so +the small number the exceptions who + + align:start position:0% +the small number the exceptions who + + + align:start position:0% +the small number the exceptions who +noticed Einstein's work in 1905 so I've + + align:start position:0% +noticed Einstein's work in 1905 so I've + + + align:start position:0% +noticed Einstein's work in 1905 so I've +sort of seen that before that's it's a + + align:start position:0% +sort of seen that before that's it's a + + + align:start position:0% +sort of seen that before that's it's a +clever way of getting back to what was + + align:start position:0% +clever way of getting back to what was + + + align:start position:0% +clever way of getting back to what was +by then kind of 10 year old results and + + align:start position:0% +by then kind of 10 year old results and + + + align:start position:0% +by then kind of 10 year old results and +so if anyone gave Einstein credit + + align:start position:0% +so if anyone gave Einstein credit + + + align:start position:0% +so if anyone gave Einstein credit +in his early years it was a as kind of + + align:start position:0% +in his early years it was a as kind of + + + align:start position:0% +in his early years it was a as kind of +like second fiddle they would refer + + align:start position:0% +like second fiddle they would refer + + + align:start position:0% +like second fiddle they would refer +sometimes to lorentz Theory Lawrence's + + align:start position:0% +sometimes to lorentz Theory Lawrence's + + + align:start position:0% +sometimes to lorentz Theory Lawrence's +electronamics or a few of them would + + align:start position:0% +electronamics or a few of them would + + + align:start position:0% +electronamics or a few of them would +refer to the lorentz Einstein theory no + + align:start position:0% +refer to the lorentz Einstein theory no + + + align:start position:0% +refer to the lorentz Einstein theory no +one referred to the Einstein Lorenz + + align:start position:0% +one referred to the Einstein Lorenz + + + align:start position:0% +one referred to the Einstein Lorenz +Theory so the second reaction didn't + + align:start position:0% +Theory so the second reaction didn't + + + align:start position:0% +Theory so the second reaction didn't +make Einstein much happier either people + + align:start position:0% +make Einstein much happier either people + + + align:start position:0% +make Einstein much happier either people +ignored it or they somehow as far as he + + align:start position:0% +ignored it or they somehow as far as he + + + align:start position:0% +ignored it or they somehow as far as he +was concerned misunderstood this as a + + align:start position:0% +was concerned misunderstood this as a + + + align:start position:0% +was concerned misunderstood this as a +kind of trivial reworking of more + + align:start position:0% +kind of trivial reworking of more + + + align:start position:0% +kind of trivial reworking of more +established results + + align:start position:0% +established results + + + align:start position:0% +established results +so even when people gave Einstein's work + + align:start position:0% +so even when people gave Einstein's work + + + align:start position:0% +so even when people gave Einstein's work +any attention within this kind of rubric + + align:start position:0% +any attention within this kind of rubric + + + align:start position:0% +any attention within this kind of rubric +of the of the framework that Lorenz had + + align:start position:0% +of the of the framework that Lorenz had + + + align:start position:0% +of the of the framework that Lorenz had +been establishing throughout the 1890s + + align:start position:0% +been establishing throughout the 1890s + + + align:start position:0% +been establishing throughout the 1890s +few people seem to notice that the + + align:start position:0% +few people seem to notice that the + + + align:start position:0% +few people seem to notice that the +conceptual underpinning was really quite + + align:start position:0% +conceptual underpinning was really quite + + + align:start position:0% +conceptual underpinning was really quite +distinct some of the equations were + + align:start position:0% +distinct some of the equations were + + + align:start position:0% +distinct some of the equations were +identical the same factor of gamma the + + align:start position:0% +identical the same factor of gamma the + + + align:start position:0% +identical the same factor of gamma the +same coordinate Transformations and so + + align:start position:0% +same coordinate Transformations and so + + + align:start position:0% +same coordinate Transformations and so +on and yet they seem to be based as we + + align:start position:0% +on and yet they seem to be based as we + + + align:start position:0% +on and yet they seem to be based as we +would now see with with hindsight on + + align:start position:0% +would now see with with hindsight on + + + align:start position:0% +would now see with with hindsight on +very very different con uh starting + + align:start position:0% +very very different con uh starting + + + align:start position:0% +very very different con uh starting +assumptions Lorenzo's work was all about + + align:start position:0% +assumptions Lorenzo's work was all about + + + align:start position:0% +assumptions Lorenzo's work was all about +The Ether the either wasn't only Central + + align:start position:0% +The Ether the either wasn't only Central + + + align:start position:0% +The Ether the either wasn't only Central +it was exerting forces these Dynamics + + align:start position:0% +it was exerting forces these Dynamics + + + align:start position:0% +it was exerting forces these Dynamics +according to Lorenzo's view it was + + align:start position:0% +according to Lorenzo's view it was + + + align:start position:0% +according to Lorenzo's view it was +literally squeezing the atoms and + + align:start position:0% +literally squeezing the atoms and + + + align:start position:0% +literally squeezing the atoms and +molecules in the arm of michelson's + + align:start position:0% +molecules in the arm of michelson's + + + align:start position:0% +molecules in the arm of michelson's +device right it was all about the + + align:start position:0% +device right it was all about the + + + align:start position:0% +device right it was all about the +elasticity and the forces exerted by a + + align:start position:0% +elasticity and the forces exerted by a + + + align:start position:0% +elasticity and the forces exerted by a +physical ether + + align:start position:0% +physical ether + + + align:start position:0% +physical ether +and as we've seen in Einstein's case in + + align:start position:0% +and as we've seen in Einstein's case in + + + align:start position:0% +and as we've seen in Einstein's case in +the opening few paragraphs he's + + align:start position:0% +the opening few paragraphs he's + + + align:start position:0% +the opening few paragraphs he's +dismissed The Ether is Superfluous his + + align:start position:0% +dismissed The Ether is Superfluous his + + + align:start position:0% +dismissed The Ether is Superfluous his +work is not about The Ether he says The + + align:start position:0% +work is not about The Ether he says The + + + align:start position:0% +work is not about The Ether he says The +Ether was a century-long distraction + + align:start position:0% +Ether was a century-long distraction + + + align:start position:0% +Ether was a century-long distraction +which is a very different starting point + + align:start position:0% +which is a very different starting point + + + align:start position:0% +which is a very different starting point +even though they both arrive at some + + align:start position:0% +even though they both arrive at some + + + align:start position:0% +even though they both arrive at some +very similar equations so even when + + align:start position:0% +very similar equations so even when + + + align:start position:0% +very similar equations so even when +people gave it attention they they sort + + align:start position:0% +people gave it attention they they sort + + + align:start position:0% +people gave it attention they they sort +of misread it or they read it in ways + + align:start position:0% +of misread it or they read it in ways + + + align:start position:0% +of misread it or they read it in ways +different from how Einstein uh probably + + align:start position:0% +different from how Einstein uh probably + + + align:start position:0% +different from how Einstein uh probably +had hoped + + align:start position:0% +had hoped + + + align:start position:0% +had hoped +and again this lasts not just until 1906 + + align:start position:0% +and again this lasts not just until 1906 + + + align:start position:0% +and again this lasts not just until 1906 +or seven even after 1909 review articles + + align:start position:0% +or seven even after 1909 review articles + + + align:start position:0% +or seven even after 1909 review articles +by people like Max funlawy here's a + + align:start position:0% +by people like Max funlawy here's a + + + align:start position:0% +by people like Max funlawy here's a +great example that I take from uh Andy + + align:start position:0% +great example that I take from uh Andy + + + align:start position:0% +great example that I take from uh Andy +Warwick's work we had some more of + + align:start position:0% +Warwick's work we had some more of + + + align:start position:0% +Warwick's work we had some more of +Andy's work to read for today and and + + align:start position:0% +Andy's work to read for today and and + + + align:start position:0% +Andy's work to read for today and and +I'll talk about that later in today's + + align:start position:0% +I'll talk about that later in today's + + + align:start position:0% +I'll talk about that later in today's +class but he has this great example in + + align:start position:0% +class but he has this great example in + + + align:start position:0% +class but he has this great example in +his article that even as late as 1913 + + align:start position:0% +his article that even as late as 1913 + + + align:start position:0% +his article that even as late as 1913 +now we're talking nearly a decade later + + align:start position:0% +now we're talking nearly a decade later + + + align:start position:0% +now we're talking nearly a decade later +right eight so fully eight years later a + + align:start position:0% +right eight so fully eight years later a + + + align:start position:0% +right eight so fully eight years later a +leading British physicist had written + + align:start position:0% +leading British physicist had written + + + align:start position:0% +leading British physicist had written +about what he called the abstruse + + align:start position:0% +about what he called the abstruse + + + align:start position:0% +about what he called the abstruse +conceptions of Einstein's knights in the + + align:start position:0% +conceptions of Einstein's knights in the + + + align:start position:0% +conceptions of Einstein's knights in the +five paper which were quote most foreign + + align:start position:0% +five paper which were quote most foreign + + + align:start position:0% +five paper which were quote most foreign +to our habits of thought and as yet + + align:start position:0% +to our habits of thought and as yet + + + align:start position:0% +to our habits of thought and as yet +scarcely anyone in this country by which + + align:start position:0% +scarcely anyone in this country by which + + + align:start position:0% +scarcely anyone in this country by which +he means Britain professed to understand + + align:start position:0% +he means Britain professed to understand + + + align:start position:0% +he means Britain professed to understand +or at least to appreciate so even the + + align:start position:0% +or at least to appreciate so even the + + + align:start position:0% +or at least to appreciate so even the +people who knew there was this person in + + align:start position:0% +people who knew there was this person in + + + align:start position:0% +people who knew there was this person in +Einstein who worked on the electronamics + + align:start position:0% +Einstein who worked on the electronamics + + + align:start position:0% +Einstein who worked on the electronamics +of moving bodies this was not kind of + + align:start position:0% +of moving bodies this was not kind of + + + align:start position:0% +of moving bodies this was not kind of +commanding attention in the way that we + + align:start position:0% +commanding attention in the way that we + + + align:start position:0% +commanding attention in the way that we +might expect because so we know how the + + align:start position:0% +might expect because so we know how the + + + align:start position:0% +might expect because so we know how the +story ends we know what Einstein would + + align:start position:0% +story ends we know what Einstein would + + + align:start position:0% +story ends we know what Einstein would +go on to to be recognized for it was a + + align:start position:0% +go on to to be recognized for it was a + + + align:start position:0% +go on to to be recognized for it was a +pretty slow uh transformation + + align:start position:0% +pretty slow uh transformation + + + align:start position:0% +pretty slow uh transformation +and we see this reflected in Einstein's + + align:start position:0% +and we see this reflected in Einstein's + + + align:start position:0% +and we see this reflected in Einstein's +own career as well so as I mentioned my + + align:start position:0% +own career as well so as I mentioned my + + + align:start position:0% +own career as well so as I mentioned my +one of my favorite factoids for the + + align:start position:0% +one of my favorite factoids for the + + + align:start position:0% +one of my favorite factoids for the +entire class today Einstein didn't not + + align:start position:0% +entire class today Einstein didn't not + + + align:start position:0% +entire class today Einstein didn't not +only didn't leave the patent office he + + align:start position:0% +only didn't leave the patent office he + + + align:start position:0% +only didn't leave the patent office he +didn't even get promoted within the + + align:start position:0% +didn't even get promoted within the + + + align:start position:0% +didn't even get promoted within the +patent office in the light of this quite + + align:start position:0% +patent office in the light of this quite + + + align:start position:0% +patent office in the light of this quite +extraordinary work his first break the + + align:start position:0% +extraordinary work his first break the + + + align:start position:0% +extraordinary work his first break the +first opportunity for the kind of career + + align:start position:0% +first opportunity for the kind of career + + + align:start position:0% +first opportunity for the kind of career +we know that he really wanted we know + + align:start position:0% +we know that he really wanted we know + + + align:start position:0% +we know that he really wanted we know +from his personal letters that had + + align:start position:0% +from his personal letters that had + + + align:start position:0% +from his personal letters that had +survived and uh are available he had + + align:start position:0% +survived and uh are available he had + + + align:start position:0% +survived and uh are available he had +been hoping for an academic position + + align:start position:0% +been hoping for an academic position + + + align:start position:0% +been hoping for an academic position +from his early early days his first big + + align:start position:0% +from his early early days his first big + + + align:start position:0% +from his early early days his first big +break along that new career path comes + + align:start position:0% +break along that new career path comes + + + align:start position:0% +break along that new career path comes +actually in 1909 + + align:start position:0% +actually in 1909 + + + align:start position:0% +actually in 1909 +around the time that fun Lowry was + + align:start position:0% +around the time that fun Lowry was + + + align:start position:0% +around the time that fun Lowry was +writing that review article on others + + align:start position:0% +writing that review article on others + + + align:start position:0% +writing that review article on others +where he was offered an assistant + + align:start position:0% +where he was offered an assistant + + + align:start position:0% +where he was offered an assistant +professor position in Zurich which was + + align:start position:0% +professor position in Zurich which was + + + align:start position:0% +professor position in Zurich which was +actually very exciting it's where he had + + align:start position:0% +actually very exciting it's where he had + + + align:start position:0% +actually very exciting it's where he had +done his own School his own University + + align:start position:0% +done his own School his own University + + + align:start position:0% +done his own School his own University +training then two years later he's given + + align:start position:0% +training then two years later he's given + + + align:start position:0% +training then two years later he's given +a kind of promotion an offer to move uh + + align:start position:0% +a kind of promotion an offer to move uh + + + align:start position:0% +a kind of promotion an offer to move uh +now to Prague he spends about one year + + align:start position:0% +now to Prague he spends about one year + + + align:start position:0% +now to Prague he spends about one year +there that is hired back at a different + + align:start position:0% +there that is hired back at a different + + + align:start position:0% +there that is hired back at a different +institution back in Zurich and then + + align:start position:0% +institution back in Zurich and then + + + align:start position:0% +institution back in Zurich and then +finally uh in the spring of 1914 in + + align:start position:0% +finally uh in the spring of 1914 in + + + align:start position:0% +finally uh in the spring of 1914 in +April or May he's invited to join the + + align:start position:0% +April or May he's invited to join the + + + align:start position:0% +April or May he's invited to join the +very very prestigious oppression Academy + + align:start position:0% +very very prestigious oppression Academy + + + align:start position:0% +very very prestigious oppression Academy +of Sciences in Berlin so roughly a + + align:start position:0% +of Sciences in Berlin so roughly a + + + align:start position:0% +of Sciences in Berlin so roughly a +decade later he's kind of promoted to + + align:start position:0% +decade later he's kind of promoted to + + + align:start position:0% +decade later he's kind of promoted to +the kind of position he'd been um really + + align:start position:0% +the kind of position he'd been um really + + + align:start position:0% +the kind of position he'd been um really +angling for all along and it comes not + + align:start position:0% +angling for all along and it comes not + + + align:start position:0% +angling for all along and it comes not +one year not two year not three years + + align:start position:0% +one year not two year not three years + + + align:start position:0% +one year not two year not three years +later but nearly a decade later and and + + align:start position:0% +later but nearly a decade later and and + + + align:start position:0% +later but nearly a decade later and and +after a lot more work has come out not + + align:start position:0% +after a lot more work has come out not + + + align:start position:0% +after a lot more work has come out not +just on the basis of this 1905 work so + + align:start position:0% +just on the basis of this 1905 work so + + + align:start position:0% +just on the basis of this 1905 work so +he's a kind of slowly kind of + + align:start position:0% +he's a kind of slowly kind of + + + align:start position:0% +he's a kind of slowly kind of +accelerating academic career starting + + align:start position:0% +accelerating academic career starting + + + align:start position:0% +accelerating academic career starting +from these very uh unusual starting + + align:start position:0% +from these very uh unusual starting + + + align:start position:0% +from these very uh unusual starting +points so I'll pause there any questions + + align:start position:0% +points so I'll pause there any questions + + + align:start position:0% +points so I'll pause there any questions +on that early uh discussion of the + + align:start position:0% +on that early uh discussion of the + + + align:start position:0% +on that early uh discussion of the +reception of Einstein's work + + align:start position:0% + + + + align:start position:0% + +is a good moment to remind you try not + + align:start position:0% +is a good moment to remind you try not + + + align:start position:0% +is a good moment to remind you try not +to annoy all your professors in college + + align:start position:0% +to annoy all your professors in college + + + align:start position:0% +to annoy all your professors in college +you'll get better letters of + + align:start position:0% +you'll get better letters of + + + align:start position:0% +you'll get better letters of +recommendation that will help you on the + + align:start position:0% +recommendation that will help you on the + + + align:start position:0% +recommendation that will help you on the +job market that was one of one of many + + align:start position:0% +job market that was one of one of many + + + align:start position:0% +job market that was one of one of many +things Einstein had done so poorly + + align:start position:0% +things Einstein had done so poorly + + + align:start position:0% +things Einstein had done so poorly +because he was kind of a dummy Einstein + + align:start position:0% +because he was kind of a dummy Einstein + + + align:start position:0% +because he was kind of a dummy Einstein +as I'd like to say was no Einstein when + + align:start position:0% +as I'd like to say was no Einstein when + + + align:start position:0% +as I'd like to say was no Einstein when +it came to his own schooling so that's + + align:start position:0% +it came to his own schooling so that's + + + align:start position:0% +it came to his own schooling so that's +life lesson number one from 8225 write + + align:start position:0% +life lesson number one from 8225 write + + + align:start position:0% +life lesson number one from 8225 write +that down any other questions about + + align:start position:0% +that down any other questions about + + + align:start position:0% +that down any other questions about +Einstein's uh or the early reception of + + align:start position:0% +Einstein's uh or the early reception of + + + align:start position:0% +Einstein's uh or the early reception of +either his own career or this body of + + align:start position:0% +either his own career or this body of + + + align:start position:0% +either his own career or this body of +work if not I'll gladly uh Press On + + align:start position:0% +work if not I'll gladly uh Press On + + + align:start position:0% +work if not I'll gladly uh Press On +okay if questions come up put them in + + align:start position:0% +okay if questions come up put them in + + + align:start position:0% +okay if questions come up put them in +the chat we'll we'll have more time to + + align:start position:0% +the chat we'll we'll have more time to + + + align:start position:0% +the chat we'll we'll have more time to +uh to talk about them but I'll go back + + align:start position:0% +uh to talk about them but I'll go back + + + align:start position:0% +uh to talk about them but I'll go back +to the slides we'll talk about now this + + align:start position:0% +to the slides we'll talk about now this + + + align:start position:0% +to the slides we'll talk about now this +next part we can dig in a bit more to to + + align:start position:0% +next part we can dig in a bit more to to + + + align:start position:0% +next part we can dig in a bit more to to +an example of a bit more significant + + align:start position:0% +an example of a bit more significant + + + align:start position:0% +an example of a bit more significant +engagement of stronger reaction and + + align:start position:0% +engagement of stronger reaction and + + + align:start position:0% +engagement of stronger reaction and +response to Einstein's work and that + + align:start position:0% +response to Einstein's work and that + + + align:start position:0% +response to Einstein's work and that +came actually somewhat surprisingly from + + align:start position:0% +came actually somewhat surprisingly from + + + align:start position:0% +came actually somewhat surprisingly from +one of Einstein's former mathematics + + align:start position:0% +one of Einstein's former mathematics + + + align:start position:0% +one of Einstein's former mathematics +teachers Herman minkowski so mikowski + + align:start position:0% +teachers Herman minkowski so mikowski + + + align:start position:0% +teachers Herman minkowski so mikowski +was a very um Elite established + + align:start position:0% +was a very um Elite established + + + align:start position:0% +was a very um Elite established +professional mathematician he was in he + + align:start position:0% +professional mathematician he was in he + + + align:start position:0% +professional mathematician he was in he +was a professor at the eth that's that + + align:start position:0% +was a professor at the eth that's that + + + align:start position:0% +was a professor at the eth that's that +uh the University of Einstein had worked + + align:start position:0% +uh the University of Einstein had worked + + + align:start position:0% +uh the University of Einstein had worked +so hard to get into the idea + + align:start position:0% +so hard to get into the idea + + + align:start position:0% +so hard to get into the idea +which I never Tire of trying to + + align:start position:0% +which I never Tire of trying to + + + align:start position:0% +which I never Tire of trying to +pronounce we can just call it eth that + + align:start position:0% +pronounce we can just call it eth that + + + align:start position:0% +pronounce we can just call it eth that +was the sort of Swiss Federal Polytech + + align:start position:0% +was the sort of Swiss Federal Polytech + + + align:start position:0% +was the sort of Swiss Federal Polytech +Institute in Zurich kind of like MIT + + align:start position:0% +Institute in Zurich kind of like MIT + + + align:start position:0% +Institute in Zurich kind of like MIT +was a mathematics professor not a + + align:start position:0% +was a mathematics professor not a + + + align:start position:0% +was a mathematics professor not a +physicist uh and through a kind of + + align:start position:0% +physicist uh and through a kind of + + + align:start position:0% +physicist uh and through a kind of +roundabout way Einstein's work was + + align:start position:0% +roundabout way Einstein's work was + + + align:start position:0% +roundabout way Einstein's work was +brought back to minkowski's attention a + + align:start position:0% +brought back to minkowski's attention a + + + align:start position:0% +brought back to minkowski's attention a +few a few years later at + + align:start position:0% +few a few years later at + + + align:start position:0% +few a few years later at +post-publication + + align:start position:0% +post-publication + + + align:start position:0% +post-publication +so it turns out minkowski was certainly + + align:start position:0% +so it turns out minkowski was certainly + + + align:start position:0% +so it turns out minkowski was certainly +not looking for Einstein's work and we + + align:start position:0% +not looking for Einstein's work and we + + + align:start position:0% +not looking for Einstein's work and we +have again some wonderful juicy colorful + + align:start position:0% +have again some wonderful juicy colorful + + + align:start position:0% +have again some wonderful juicy colorful +letters that survive of minkowski + + align:start position:0% +letters that survive of minkowski + + + align:start position:0% +letters that survive of minkowski +basically talking behind Einstein his + + align:start position:0% +basically talking behind Einstein his + + + align:start position:0% +basically talking behind Einstein his +back and vice versa so we know that when + + align:start position:0% +back and vice versa so we know that when + + + align:start position:0% +back and vice versa so we know that when +Einstein was a university student he + + align:start position:0% +Einstein was a university student he + + + align:start position:0% +Einstein was a university student he +worked so hard to get into the eth what + + align:start position:0% +worked so hard to get into the eth what + + + align:start position:0% +worked so hard to get into the eth what +did he do he began cutting classes + + align:start position:0% +did he do he began cutting classes + + + align:start position:0% +did he do he began cutting classes +especially classes of Faculty for whom + + align:start position:0% +especially classes of Faculty for whom + + + align:start position:0% +especially classes of Faculty for whom +he had little respect + + align:start position:0% +he had little respect + + + align:start position:0% +he had little respect +and that happens to include Hammond + + align:start position:0% +and that happens to include Hammond + + + align:start position:0% +and that happens to include Hammond +nikowski so even though he was + + align:start position:0% +nikowski so even though he was + + + align:start position:0% +nikowski so even though he was +registered and took classes for credit + + align:start position:0% +registered and took classes for credit + + + align:start position:0% +registered and took classes for credit +from minkowski in the math department he + + align:start position:0% +from minkowski in the math department he + + + align:start position:0% +from minkowski in the math department he +rarely showed up and minkowski noticed + + align:start position:0% +rarely showed up and minkowski noticed + + + align:start position:0% +rarely showed up and minkowski noticed +that so Einstein used to borrow notes + + align:start position:0% +that so Einstein used to borrow notes + + + align:start position:0% +that so Einstein used to borrow notes +from several friends from his at the + + align:start position:0% +from several friends from his at the + + + align:start position:0% +from several friends from his at the +time girlfriend who became his first + + align:start position:0% +time girlfriend who became his first + + + align:start position:0% +time girlfriend who became his first +wife maleva marriage she was also a + + align:start position:0% +wife maleva marriage she was also a + + + align:start position:0% +wife maleva marriage she was also a +physics student at the eth and doing + + align:start position:0% +physics student at the eth and doing + + + align:start position:0% +physics student at the eth and doing +actually quite well in her mathematics + + align:start position:0% +actually quite well in her mathematics + + + align:start position:0% +actually quite well in her mathematics +classes she would very dutifully attend + + align:start position:0% +classes she would very dutifully attend + + + align:start position:0% +classes she would very dutifully attend +take very careful notes share them with + + align:start position:0% +take very careful notes share them with + + + align:start position:0% +take very careful notes share them with +her good for nothing boyfriend Albert + + align:start position:0% +her good for nothing boyfriend Albert + + + align:start position:0% +her good for nothing boyfriend Albert +Einstein he would cram before the exam + + align:start position:0% +Einstein he would cram before the exam + + + align:start position:0% +Einstein he would cram before the exam +and kind of do it okay another one of + + align:start position:0% +and kind of do it okay another one of + + + align:start position:0% +and kind of do it okay another one of +Einstein's close buddies from + + align:start position:0% +Einstein's close buddies from + + + align:start position:0% +Einstein's close buddies from +undergraduate days Marcel Grossman did + + align:start position:0% +undergraduate days Marcel Grossman did + + + align:start position:0% +undergraduate days Marcel Grossman did +the same thing Grossman went on to a + + align:start position:0% +the same thing Grossman went on to a + + + align:start position:0% +the same thing Grossman went on to a +career as a mathematician himself so + + align:start position:0% +career as a mathematician himself so + + + align:start position:0% +career as a mathematician himself so +would basically cut classes from people + + align:start position:0% +would basically cut classes from people + + + align:start position:0% +would basically cut classes from people +like minkowski + + align:start position:0% +like minkowski + + + align:start position:0% +like minkowski +and then catch up and like just skate + + align:start position:0% +and then catch up and like just skate + + + align:start position:0% +and then catch up and like just skate +through he would just like barely pass + + align:start position:0% +through he would just like barely pass + + + align:start position:0% +through he would just like barely pass +by cramming the night before don't do + + align:start position:0% +by cramming the night before don't do + + + align:start position:0% +by cramming the night before don't do +that on paper one please + + align:start position:0% +that on paper one please + + + align:start position:0% +that on paper one please +so um a friend of Einstein's encouraged + + align:start position:0% +so um a friend of Einstein's encouraged + + + align:start position:0% +so um a friend of Einstein's encouraged +the professor minkowski to read this + + align:start position:0% +the professor minkowski to read this + + + align:start position:0% +the professor minkowski to read this +1905 paper a few years after to come out + + align:start position:0% +1905 paper a few years after to come out + + + align:start position:0% +1905 paper a few years after to come out +and minkowski wrote back I really + + align:start position:0% +and minkowski wrote back I really + + + align:start position:0% +and minkowski wrote back I really +wouldn't have thought Einstein capable + + align:start position:0% +wouldn't have thought Einstein capable + + + align:start position:0% +wouldn't have thought Einstein capable +of that he wrote mankowster wrote to + + align:start position:0% +of that he wrote mankowster wrote to + + + align:start position:0% +of that he wrote mankowster wrote to +another colleague Einstein's paper came + + align:start position:0% +another colleague Einstein's paper came + + + align:start position:0% +another colleague Einstein's paper came +as a tremendous surprise because in his + + align:start position:0% +as a tremendous surprise because in his + + + align:start position:0% +as a tremendous surprise because in his +student days Einstein had been a lazy + + align:start position:0% +student days Einstein had been a lazy + + + align:start position:0% +student days Einstein had been a lazy +dog he never bothered about mathematics + + align:start position:0% +dog he never bothered about mathematics + + + align:start position:0% +dog he never bothered about mathematics +at all so much for minkowski having a + + align:start position:0% +at all so much for minkowski having a + + + align:start position:0% +at all so much for minkowski having a +high opinion of young Albert Einstein + + align:start position:0% +high opinion of young Albert Einstein + + + align:start position:0% +high opinion of young Albert Einstein +so once minkowski was convinced even + + align:start position:0% +so once minkowski was convinced even + + + align:start position:0% +so once minkowski was convinced even +look at this again a few years post + + align:start position:0% +look at this again a few years post + + + align:start position:0% +look at this again a few years post +publication he quickly became convinced + + align:start position:0% +publication he quickly became convinced + + + align:start position:0% +publication he quickly became convinced +that Einstein was still a lazy dog or at + + align:start position:0% +that Einstein was still a lazy dog or at + + + align:start position:0% +that Einstein was still a lazy dog or at +least was still making things + + align:start position:0% +least was still making things + + + align:start position:0% +least was still making things +unnecessarily complicated so minkowski + + align:start position:0% +unnecessarily complicated so minkowski + + + align:start position:0% +unnecessarily complicated so minkowski +thought Einstein had a few interesting + + align:start position:0% +thought Einstein had a few interesting + + + align:start position:0% +thought Einstein had a few interesting +ideas in this paper from 1905 but it + + align:start position:0% +ideas in this paper from 1905 but it + + + align:start position:0% +ideas in this paper from 1905 but it +really kind of messed things up as far + + align:start position:0% +really kind of messed things up as far + + + align:start position:0% +really kind of messed things up as far +as minkowski was concerned but he really + + align:start position:0% +as minkowski was concerned but he really + + + align:start position:0% +as minkowski was concerned but he really +missed the the main point of his own + + align:start position:0% +missed the the main point of his own + + + align:start position:0% +missed the the main point of his own +work Mankowski was convinced that + + align:start position:0% +work Mankowski was convinced that + + + align:start position:0% +work Mankowski was convinced that +Einstein's understanding of Einstein's + + align:start position:0% +Einstein's understanding of Einstein's + + + align:start position:0% +Einstein's understanding of Einstein's +work was not the best understanding at + + align:start position:0% +work was not the best understanding at + + + align:start position:0% +work was not the best understanding at +all so in fact minkowski said about + + align:start position:0% +all so in fact minkowski said about + + + align:start position:0% +all so in fact minkowski said about +reformulating this work in his own way + + align:start position:0% +reformulating this work in his own way + + + align:start position:0% +reformulating this work in his own way +in around 1907 it was actually published + + align:start position:0% +in around 1907 it was actually published + + + align:start position:0% +in around 1907 it was actually published +posthumously in 1908. minkowski died + + align:start position:0% +posthumously in 1908. minkowski died + + + align:start position:0% +posthumously in 1908. minkowski died +rather young so he gave this famous + + align:start position:0% +rather young so he gave this famous + + + align:start position:0% +rather young so he gave this famous +lecture and uh and it was published soon + + align:start position:0% +lecture and uh and it was published soon + + + align:start position:0% +lecture and uh and it was published soon +after he passed away + + align:start position:0% +after he passed away + + + align:start position:0% +after he passed away +who was this person Herman minkowski he + + align:start position:0% +who was this person Herman minkowski he + + + align:start position:0% +who was this person Herman minkowski he +wasn't only a mathematician at the eth + + align:start position:0% +wasn't only a mathematician at the eth + + + align:start position:0% +wasn't only a mathematician at the eth +in Zurich he was in particular a + + align:start position:0% +in Zurich he was in particular a + + + align:start position:0% +in Zurich he was in particular a +geometry his specialty within + + align:start position:0% +geometry his specialty within + + + align:start position:0% +geometry his specialty within +mathematics was kind of pure geometry in + + align:start position:0% +mathematics was kind of pure geometry in + + + align:start position:0% +mathematics was kind of pure geometry in +fact he was he was kind of like an + + align:start position:0% +fact he was he was kind of like an + + + align:start position:0% +fact he was he was kind of like an +evangelist for geometry he'd written a + + align:start position:0% +evangelist for geometry he'd written a + + + align:start position:0% +evangelist for geometry he'd written a +book uh first published in 1896 the + + align:start position:0% +book uh first published in 1896 the + + + align:start position:0% +book uh first published in 1896 the +cover here is from a later Edition + + align:start position:0% +cover here is from a later Edition + + + align:start position:0% +cover here is from a later Edition +called the geometry of numbers he + + align:start position:0% +called the geometry of numbers he + + + align:start position:0% +called the geometry of numbers he +actually wanted to remake abstract + + align:start position:0% +actually wanted to remake abstract + + + align:start position:0% +actually wanted to remake abstract +fields of pure mathematics like number + + align:start position:0% +fields of pure mathematics like number + + + align:start position:0% +fields of pure mathematics like number +Theory make those part of geometry as + + align:start position:0% +Theory make those part of geometry as + + + align:start position:0% +Theory make those part of geometry as +well so he wasn't only kind of an expert + + align:start position:0% +well so he wasn't only kind of an expert + + + align:start position:0% +well so he wasn't only kind of an expert +in Geometry he thought geometry was + + align:start position:0% +in Geometry he thought geometry was + + + align:start position:0% +in Geometry he thought geometry was +would unlock the secrets for like all of + + align:start position:0% +would unlock the secrets for like all of + + + align:start position:0% +would unlock the secrets for like all of +math and and that's all he cared about + + align:start position:0% +math and and that's all he cared about + + + align:start position:0% +math and and that's all he cared about +like that was the key to everything so + + align:start position:0% +like that was the key to everything so + + + align:start position:0% +like that was the key to everything so +he really was a geometer all the way + + align:start position:0% +he really was a geometer all the way + + + align:start position:0% +he really was a geometer all the way +through + + align:start position:0% +through + + + align:start position:0% +through +so when he then later turned to + + align:start position:0% +so when he then later turned to + + + align:start position:0% +so when he then later turned to +Einstein's work about two years after it + + align:start position:0% +Einstein's work about two years after it + + + align:start position:0% +Einstein's work about two years after it +had been published he did so as a + + align:start position:0% +had been published he did so as a + + + align:start position:0% +had been published he did so as a +geometer not as a physicist not as a + + align:start position:0% +geometer not as a physicist not as a + + + align:start position:0% +geometer not as a physicist not as a +philosopher interested in mock or + + align:start position:0% +philosopher interested in mock or + + + align:start position:0% +philosopher interested in mock or +positive positivism to mikowski + + align:start position:0% +positive positivism to mikowski + + + align:start position:0% +positive positivism to mikowski +Einstein's work held lessons that were + + align:start position:0% +Einstein's work held lessons that were + + + align:start position:0% +Einstein's work held lessons that were +best understood uh through using the + + align:start position:0% +best understood uh through using the + + + align:start position:0% +best understood uh through using the +tools of geometry + + align:start position:0% +tools of geometry + + + align:start position:0% +tools of geometry +so one of the first things minkowski did + + align:start position:0% +so one of the first things minkowski did + + + align:start position:0% +so one of the first things minkowski did +is something we all take for granted + + align:start position:0% +is something we all take for granted + + + align:start position:0% +is something we all take for granted +today you many of you have probably seen + + align:start position:0% +today you many of you have probably seen + + + align:start position:0% +today you many of you have probably seen +this before we now will call these + + align:start position:0% +this before we now will call these + + + align:start position:0% +this before we now will call these +things space-time diagrams or often + + align:start position:0% +things space-time diagrams or often + + + align:start position:0% +things space-time diagrams or often +we'll call them minkowski diagrams these + + align:start position:0% +we'll call them minkowski diagrams these + + + align:start position:0% +we'll call them minkowski diagrams these +were one of the things that Hermann + + align:start position:0% +were one of the things that Hermann + + + align:start position:0% +were one of the things that Hermann +minkowski introduced once he kind of + + align:start position:0% +minkowski introduced once he kind of + + + align:start position:0% +minkowski introduced once he kind of +grudgingly began to pay attention to + + align:start position:0% +grudgingly began to pay attention to + + + align:start position:0% +grudgingly began to pay attention to +this paper of Albert Einstein + + align:start position:0% +this paper of Albert Einstein + + + align:start position:0% +this paper of Albert Einstein +so what are we going to do with these + + align:start position:0% +so what are we going to do with these + + + align:start position:0% +so what are we going to do with these +with these space-time diagrams to make + + align:start position:0% +with these space-time diagrams to make + + + align:start position:0% +with these space-time diagrams to make +things simple we'll consider Motion in + + align:start position:0% +things simple we'll consider Motion in + + + align:start position:0% +things simple we'll consider Motion in +only one direction of space let's say + + align:start position:0% +only one direction of space let's say + + + align:start position:0% +only one direction of space let's say +the x-axis so quite typically the + + align:start position:0% +the x-axis so quite typically the + + + align:start position:0% +the x-axis so quite typically the +convention very quickly became it will + + align:start position:0% +convention very quickly became it will + + + align:start position:0% +convention very quickly became it will +will measure uh locations of space along + + align:start position:0% +will measure uh locations of space along + + + align:start position:0% +will measure uh locations of space along +the horizontal axis or the x-axis and + + align:start position:0% +the horizontal axis or the x-axis and + + + align:start position:0% +the horizontal axis or the x-axis and +we'll measure changes in time + + align:start position:0% +we'll measure changes in time + + + align:start position:0% +we'll measure changes in time +along the vertical axis okay so now we + + align:start position:0% +along the vertical axis okay so now we + + + align:start position:0% +along the vertical axis okay so now we +have a two-dimensional plot to measure + + align:start position:0% +have a two-dimensional plot to measure + + + align:start position:0% +have a two-dimensional plot to measure +to with which to to make sense of motion + + align:start position:0% +to with which to to make sense of motion + + + align:start position:0% +to with which to to make sense of motion +in space and time these are space time + + align:start position:0% +in space and time these are space time + + + align:start position:0% +in space and time these are space time +diagrams one of the next things that + + align:start position:0% +diagrams one of the next things that + + + align:start position:0% +diagrams one of the next things that +became very very common very quickly + + align:start position:0% +became very very common very quickly + + + align:start position:0% +became very very common very quickly +with these uh kinds of graphs was to use + + align:start position:0% +with these uh kinds of graphs was to use + + + align:start position:0% +with these uh kinds of graphs was to use +very convenient coordinates coordinates + + align:start position:0% +very convenient coordinates coordinates + + + align:start position:0% +very convenient coordinates coordinates +in which light waves would travel one + + align:start position:0% +in which light waves would travel one + + + align:start position:0% +in which light waves would travel one +unit of space one tick along the x-axis + + align:start position:0% +unit of space one tick along the x-axis + + + align:start position:0% +unit of space one tick along the x-axis +for every one tick for every one unit of + + align:start position:0% +for every one tick for every one unit of + + + align:start position:0% +for every one tick for every one unit of +time + + align:start position:0% +time + + + align:start position:0% +time +so for example if we're going to measure + + align:start position:0% +so for example if we're going to measure + + + align:start position:0% +so for example if we're going to measure +time in seconds a very common unit of uh + + align:start position:0% +time in seconds a very common unit of uh + + + align:start position:0% +time in seconds a very common unit of uh +with which to measure time then we + + align:start position:0% +with which to measure time then we + + + align:start position:0% +with which to measure time then we +better not measure the spatial distances + + align:start position:0% +better not measure the spatial distances + + + align:start position:0% +better not measure the spatial distances +in either meters or feet or kilometers + + align:start position:0% +in either meters or feet or kilometers + + + align:start position:0% +in either meters or feet or kilometers +or even parsecs we're going to measure + + align:start position:0% +or even parsecs we're going to measure + + + align:start position:0% +or even parsecs we're going to measure +them in light seconds which is the + + align:start position:0% +them in light seconds which is the + + + align:start position:0% +them in light seconds which is the +distance light will travel in one second + + align:start position:0% +distance light will travel in one second + + + align:start position:0% +distance light will travel in one second +so we're going to measure the distances + + align:start position:0% +so we're going to measure the distances + + + align:start position:0% +so we're going to measure the distances +in units such that light will travel to + + align:start position:0% +in units such that light will travel to + + + align:start position:0% +in units such that light will travel to +one of those spatial units in one unit + + align:start position:0% +one of those spatial units in one unit + + + align:start position:0% +one of those spatial units in one unit +of time for example seconds and light + + align:start position:0% +of time for example seconds and light + + + align:start position:0% +of time for example seconds and light +seconds so what we're really doing in + + align:start position:0% +seconds so what we're really doing in + + + align:start position:0% +seconds so what we're really doing in +effect is scaling the speed of light to + + align:start position:0% +effect is scaling the speed of light to + + + align:start position:0% +effect is scaling the speed of light to +be what and therefore when we go to plot + + align:start position:0% +be what and therefore when we go to plot + + + align:start position:0% +be what and therefore when we go to plot +the motion of light rays or light waves + + align:start position:0% +the motion of light rays or light waves + + + align:start position:0% +the motion of light rays or light waves +on these space-time diagrams + + align:start position:0% +on these space-time diagrams + + + align:start position:0% +on these space-time diagrams +they'll follow these very simple 45 + + align:start position:0% +they'll follow these very simple 45 + + + align:start position:0% +they'll follow these very simple 45 +degree diagonals their slope is fixed to + + align:start position:0% +degree diagonals their slope is fixed to + + + align:start position:0% +degree diagonals their slope is fixed to +be always inclined at 45 degrees because + + align:start position:0% +be always inclined at 45 degrees because + + + align:start position:0% +be always inclined at 45 degrees because +we've chosen our coordinates such that + + align:start position:0% +we've chosen our coordinates such that + + + align:start position:0% +we've chosen our coordinates such that +they will always Traverse one unit of + + align:start position:0% +they will always Traverse one unit of + + + align:start position:0% +they will always Traverse one unit of +space in one area of time now why will + + align:start position:0% +space in one area of time now why will + + + align:start position:0% +space in one area of time now why will +they always travel at that slope because + + align:start position:0% +they always travel at that slope because + + + align:start position:0% +they always travel at that slope because +if we take Einstein's second postulate + + align:start position:0% +if we take Einstein's second postulate + + + align:start position:0% +if we take Einstein's second postulate +seriously light will always be traveling + + align:start position:0% +seriously light will always be traveling + + + align:start position:0% +seriously light will always be traveling +at that single Universal speed the speed + + align:start position:0% +at that single Universal speed the speed + + + align:start position:0% +at that single Universal speed the speed +of light therefore they'll have a single + + align:start position:0% +of light therefore they'll have a single + + + align:start position:0% +of light therefore they'll have a single +fixed slope they could travel off to the + + align:start position:0% +fixed slope they could travel off to the + + + align:start position:0% +fixed slope they could travel off to the +left and therefore we then we'd have a + + align:start position:0% +left and therefore we then we'd have a + + + align:start position:0% +left and therefore we then we'd have a +world line like this inclined at 45 + + align:start position:0% +world line like this inclined at 45 + + + align:start position:0% +world line like this inclined at 45 +degrees pointing off to the left they + + align:start position:0% +degrees pointing off to the left they + + + align:start position:0% +degrees pointing off to the left they +can travel to the right but they can't + + align:start position:0% +can travel to the right but they can't + + + align:start position:0% +can travel to the right but they can't +change the slope that's the Imp that's + + align:start position:0% +change the slope that's the Imp that's + + + align:start position:0% +change the slope that's the Imp that's +the the impact of Einstein's second + + align:start position:0% +the the impact of Einstein's second + + + align:start position:0% +the the impact of Einstein's second +posture okay so far so good we can do + + align:start position:0% +posture okay so far so good we can do + + + align:start position:0% +posture okay so far so good we can do +things like we can plot more than just + + align:start position:0% +things like we can plot more than just + + + align:start position:0% +things like we can plot more than just +the path of light + + align:start position:0% +the path of light + + + align:start position:0% +the path of light +here's this is actually this is real + + align:start position:0% +here's this is actually this is real + + + align:start position:0% +here's this is actually this is real +data this is how I spend my time these + + align:start position:0% +data this is how I spend my time these + + + align:start position:0% +data this is how I spend my time these +days in quarantine I don't go anywhere + + align:start position:0% +days in quarantine I don't go anywhere + + + align:start position:0% +days in quarantine I don't go anywhere +right so my my uh position my my the + + align:start position:0% +right so my my uh position my my the + + + align:start position:0% +right so my my uh position my my the +plot of my motion through space and time + + align:start position:0% +plot of my motion through space and time + + + align:start position:0% +plot of my motion through space and time +is really easy now uh I just sit in one + + align:start position:0% +is really easy now uh I just sit in one + + + align:start position:0% +is really easy now uh I just sit in one +location of space like this chair and I + + align:start position:0% +location of space like this chair and I + + + align:start position:0% +location of space like this chair and I +don't move so all that happens is time + + align:start position:0% +don't move so all that happens is time + + + align:start position:0% +don't move so all that happens is time +Ticks inexorably by I just get older and + + align:start position:0% +Ticks inexorably by I just get older and + + + align:start position:0% +Ticks inexorably by I just get older and +older and older but I'm not moving + + align:start position:0% +older and older but I'm not moving + + + align:start position:0% +older and older but I'm not moving +around or barely so we can plot what's + + align:start position:0% +around or barely so we can plot what's + + + align:start position:0% +around or barely so we can plot what's +called my world line that's the + + align:start position:0% +called my world line that's the + + + align:start position:0% +called my world line that's the +vocabulary that gets used now with these + + align:start position:0% +vocabulary that gets used now with these + + + align:start position:0% +vocabulary that gets used now with these +space-time diagrams dating really back + + align:start position:0% +space-time diagrams dating really back + + + align:start position:0% +space-time diagrams dating really back +to the era of Herman minkowski + + align:start position:0% +to the era of Herman minkowski + + + align:start position:0% +to the era of Herman minkowski +so for any object we can chart its + + align:start position:0% +so for any object we can chart its + + + align:start position:0% +so for any object we can chart its +motion through space and time in one of + + align:start position:0% +motion through space and time in one of + + + align:start position:0% +motion through space and time in one of +these plots if it's not changing its + + align:start position:0% +these plots if it's not changing its + + + align:start position:0% +these plots if it's not changing its +location but only moving through time + + align:start position:0% +location but only moving through time + + + align:start position:0% +location but only moving through time +it'll have a straight line heading + + align:start position:0% +it'll have a straight line heading + + + align:start position:0% +it'll have a straight line heading +straight up the page it will move if + + align:start position:0% +straight up the page it will move if + + + align:start position:0% +straight up the page it will move if +it's light it's going to move at this + + align:start position:0% +it's light it's going to move at this + + + align:start position:0% +it's light it's going to move at this +fixed uh inclination or slope and of + + align:start position:0% +fixed uh inclination or slope and of + + + align:start position:0% +fixed uh inclination or slope and of +course if my family forces me to get off + + align:start position:0% +course if my family forces me to get off + + + align:start position:0% +course if my family forces me to get off +the chair and go out for a jog then I'll + + align:start position:0% +the chair and go out for a jog then I'll + + + align:start position:0% +the chair and go out for a jog then I'll +have a more complicated World line I'll + + align:start position:0% +have a more complicated World line I'll + + + align:start position:0% +have a more complicated World line I'll +be moving I'll be changing my location + + align:start position:0% +be moving I'll be changing my location + + + align:start position:0% +be moving I'll be changing my location +over time not nearly as fast as light + + align:start position:0% +over time not nearly as fast as light + + + align:start position:0% +over time not nearly as fast as light +not really as fast as shown here this is + + align:start position:0% +not really as fast as shown here this is + + + align:start position:0% +not really as fast as shown here this is +like supersonic jet pack but I will + + align:start position:0% +like supersonic jet pack but I will + + + align:start position:0% +like supersonic jet pack but I will +sometimes be moving to the right at some + + align:start position:0% +sometimes be moving to the right at some + + + align:start position:0% +sometimes be moving to the right at some +speed I might change directions later + + align:start position:0% +speed I might change directions later + + + align:start position:0% +speed I might change directions later +and move to the left but whatever I do + + align:start position:0% +and move to the left but whatever I do + + + align:start position:0% +and move to the left but whatever I do +I'll be moving at a speed slower than + + align:start position:0% +I'll be moving at a speed slower than + + + align:start position:0% +I'll be moving at a speed slower than +light that's for sure and therefore the + + align:start position:0% +light that's for sure and therefore the + + + align:start position:0% +light that's for sure and therefore the +slope of my world line is limited to + + align:start position:0% +slope of my world line is limited to + + + align:start position:0% +slope of my world line is limited to +never be as sharp as inclined as a 45 + + align:start position:0% +never be as sharp as inclined as a 45 + + + align:start position:0% +never be as sharp as inclined as a 45 +degree line so I might have a + + align:start position:0% +degree line so I might have a + + + align:start position:0% +degree line so I might have a +non-trivial world line but it's a way + + align:start position:0% +non-trivial world line but it's a way + + + align:start position:0% +non-trivial world line but it's a way +nonetheless to chart my motion to space + + align:start position:0% +nonetheless to chart my motion to space + + + align:start position:0% +nonetheless to chart my motion to space +and time + + align:start position:0% +and time + + + align:start position:0% +and time +many of you probably seen that before + + align:start position:0% +many of you probably seen that before + + + align:start position:0% +many of you probably seen that before +this comes from the geometer Hammond + + align:start position:0% +this comes from the geometer Hammond + + + align:start position:0% +this comes from the geometer Hammond +minkowski trying to make sense of + + align:start position:0% +minkowski trying to make sense of + + + align:start position:0% +minkowski trying to make sense of +Einstein's work okay now let's go back + + align:start position:0% +Einstein's work okay now let's go back + + + align:start position:0% +Einstein's work okay now let's go back +to one of the scenarios that Einstein + + align:start position:0% +to one of the scenarios that Einstein + + + align:start position:0% +to one of the scenarios that Einstein +introduced in those opening Pages the + + align:start position:0% +introduced in those opening Pages the + + + align:start position:0% +introduced in those opening Pages the +part that you have for your assignment I + + align:start position:0% +part that you have for your assignment I + + + align:start position:0% +part that you have for your assignment I +was a 1905 paper let's imagine that I'm + + align:start position:0% +was a 1905 paper let's imagine that I'm + + + align:start position:0% +was a 1905 paper let's imagine that I'm +standing still so I'm back to my very + + align:start position:0% +standing still so I'm back to my very + + + align:start position:0% +standing still so I'm back to my very +trivial straight up the page World line + + align:start position:0% +trivial straight up the page World line + + + align:start position:0% +trivial straight up the page World line +I'm back in my chair + + align:start position:0% +I'm back in my chair + + + align:start position:0% +I'm back in my chair +and I'm standing exactly equal distance + + align:start position:0% +and I'm standing exactly equal distance + + + align:start position:0% +and I'm standing exactly equal distance +from two colleagues who are at locations + + align:start position:0% +from two colleagues who are at locations + + + align:start position:0% +from two colleagues who are at locations +A and B so I'm in equal distance along + + align:start position:0% +A and B so I'm in equal distance along + + + align:start position:0% +A and B so I'm in equal distance along +the x-axis + + align:start position:0% +the x-axis + + + align:start position:0% +the x-axis +from each of my colleagues I've asked + + align:start position:0% +from each of my colleagues I've asked + + + align:start position:0% +from each of my colleagues I've asked +them to please shine their lanterns at + + align:start position:0% +them to please shine their lanterns at + + + align:start position:0% +them to please shine their lanterns at +me at the same time if they've really + + align:start position:0% +me at the same time if they've really + + + align:start position:0% +me at the same time if they've really +done that then I'll receive the light + + align:start position:0% +done that then I'll receive the light + + + align:start position:0% +done that then I'll receive the light +waves from each of them at the same time + + align:start position:0% +waves from each of them at the same time + + + align:start position:0% +waves from each of them at the same time +the light wave traveling from B toward + + align:start position:0% +the light wave traveling from B toward + + + align:start position:0% +the light wave traveling from B toward +me and the light wave traveling from a + + align:start position:0% +me and the light wave traveling from a + + + align:start position:0% +me and the light wave traveling from a +toward me will arrive at my location at + + align:start position:0% +toward me will arrive at my location at + + + align:start position:0% +toward me will arrive at my location at +the same time sorry + + align:start position:0% +the same time sorry + + + align:start position:0% +the same time sorry +and if so then I know that A and B + + align:start position:0% +and if so then I know that A and B + + + align:start position:0% +and if so then I know that A and B +emitted their light waves simultaneously + + align:start position:0% +emitted their light waves simultaneously + + + align:start position:0% +emitted their light waves simultaneously +because the speed of light is fixed so + + align:start position:0% +because the speed of light is fixed so + + + align:start position:0% +because the speed of light is fixed so +the light wave from say the lantern held + + align:start position:0% +the light wave from say the lantern held + + + align:start position:0% +the light wave from say the lantern held +by person B couldn't have either sped up + + align:start position:0% +by person B couldn't have either sped up + + + align:start position:0% +by person B couldn't have either sped up +or slowed down it had no choice but to + + align:start position:0% +or slowed down it had no choice but to + + + align:start position:0% +or slowed down it had no choice but to +travel along this world line at exactly + + align:start position:0% +travel along this world line at exactly + + + align:start position:0% +travel along this world line at exactly +45 degrees likewise for the light wave + + align:start position:0% +45 degrees likewise for the light wave + + + align:start position:0% +45 degrees likewise for the light wave +from my friend at position a so if I + + align:start position:0% +from my friend at position a so if I + + + align:start position:0% +from my friend at position a so if I +know I'm equal distances along the + + align:start position:0% +know I'm equal distances along the + + + align:start position:0% +know I'm equal distances along the +x-axis from A and B and I receive both + + align:start position:0% +x-axis from A and B and I receive both + + + align:start position:0% +x-axis from A and B and I receive both +light waves at the same time here then + + align:start position:0% +light waves at the same time here then + + + align:start position:0% +light waves at the same time here then +they must have been emitted + + align:start position:0% +they must have been emitted + + + align:start position:0% +they must have been emitted +simultaneously there so now I can + + align:start position:0% +simultaneously there so now I can + + + align:start position:0% +simultaneously there so now I can +establish lines of simultaneity + + align:start position:0% +establish lines of simultaneity + + + align:start position:0% +establish lines of simultaneity +every point along this x-axis would have + + align:start position:0% +every point along this x-axis would have + + + align:start position:0% +every point along this x-axis would have +the same value of time in my coordinate + + align:start position:0% +the same value of time in my coordinate + + + align:start position:0% +the same value of time in my coordinate +system + + align:start position:0% +system + + + align:start position:0% +system +the value of t on my T axis is the same + + align:start position:0% +the value of t on my T axis is the same + + + align:start position:0% +the value of t on my T axis is the same +so the way I've set things up here event + + align:start position:0% +so the way I've set things up here event + + + align:start position:0% +so the way I've set things up here event +a corresponds to the time T equals zero + + align:start position:0% +a corresponds to the time T equals zero + + + align:start position:0% +a corresponds to the time T equals zero +event B corresponds to time equals zero + + align:start position:0% +event B corresponds to time equals zero + + + align:start position:0% +event B corresponds to time equals zero +at time equals zero sitting here on my + + align:start position:0% +at time equals zero sitting here on my + + + align:start position:0% +at time equals zero sitting here on my +chair + + align:start position:0% +chair + + + align:start position:0% +chair +likewise uh every other sort of moment + + align:start position:0% +likewise uh every other sort of moment + + + align:start position:0% +likewise uh every other sort of moment +line of simultaneity is parallel to the + + align:start position:0% +line of simultaneity is parallel to the + + + align:start position:0% +line of simultaneity is parallel to the +x-axis they're all parallel to the line + + align:start position:0% +x-axis they're all parallel to the line + + + align:start position:0% +x-axis they're all parallel to the line +T equals zero so I can imagine every + + align:start position:0% +T equals zero so I can imagine every + + + align:start position:0% +T equals zero so I can imagine every +event in my set of coordinates that have + + align:start position:0% +event in my set of coordinates that have + + + align:start position:0% +event in my set of coordinates that have +the assignment T equals one instead of T + + align:start position:0% +the assignment T equals one instead of T + + + align:start position:0% +the assignment T equals one instead of T +equals zero all of these were + + align:start position:0% +equals zero all of these were + + + align:start position:0% +equals zero all of these were +simultaneous with each other not + + align:start position:0% +simultaneous with each other not + + + align:start position:0% +simultaneous with each other not +simultaneous with events A and B or + + align:start position:0% +simultaneous with events A and B or + + + align:start position:0% +simultaneous with events A and B or +every point along the line T equals two + + align:start position:0% +every point along the line T equals two + + + align:start position:0% +every point along the line T equals two +and so on this is I'm sure very very + + align:start position:0% +and so on this is I'm sure very very + + + align:start position:0% +and so on this is I'm sure very very +familiar this is how we use graphs all + + align:start position:0% +familiar this is how we use graphs all + + + align:start position:0% +familiar this is how we use graphs all +the time when calcium try to just kind + + align:start position:0% +the time when calcium try to just kind + + + align:start position:0% +the time when calcium try to just kind +of give us a more straightforward + + align:start position:0% +of give us a more straightforward + + + align:start position:0% +of give us a more straightforward +geometrical interpretation Ford Einstein + + align:start position:0% +geometrical interpretation Ford Einstein + + + align:start position:0% +geometrical interpretation Ford Einstein +kind of belabors in those opening pages + + align:start position:0% +kind of belabors in those opening pages + + + align:start position:0% +kind of belabors in those opening pages +about what do we mean by simultaneous + + align:start position:0% +about what do we mean by simultaneous + + + align:start position:0% +about what do we mean by simultaneous +events in our frame of reference + + align:start position:0% +events in our frame of reference + + + align:start position:0% +events in our frame of reference +these are events that occur along a line + + align:start position:0% +these are events that occur along a line + + + align:start position:0% +these are events that occur along a line +of simultaneity well now we can use our + + align:start position:0% +of simultaneity well now we can use our + + + align:start position:0% +of simultaneity well now we can use our +set of coordinates our x and t and and + + align:start position:0% +set of coordinates our x and t and and + + + align:start position:0% +set of coordinates our x and t and and +map the motion of some other object + + align:start position:0% +map the motion of some other object + + + align:start position:0% +map the motion of some other object +that's moving with respect to us for + + align:start position:0% +that's moving with respect to us for + + + align:start position:0% +that's moving with respect to us for +example Einstein's favorite object a + + align:start position:0% +example Einstein's favorite object a + + + align:start position:0% +example Einstein's favorite object a +train + + align:start position:0% +train + + + align:start position:0% +train +so now we can chart the world lines of + + align:start position:0% +so now we can chart the world lines of + + + align:start position:0% +so now we can chart the world lines of +the back of the Train the middle of the + + align:start position:0% +the back of the Train the middle of the + + + align:start position:0% +the back of the Train the middle of the +train and the front of the train as the + + align:start position:0% +train and the front of the train as the + + + align:start position:0% +train and the front of the train as the +entire assembly moves past us while we + + align:start position:0% +entire assembly moves past us while we + + + align:start position:0% +entire assembly moves past us while we +stand still on the train platform so + + align:start position:0% +stand still on the train platform so + + + align:start position:0% +stand still on the train platform so +this is our Mo our mapping of the moving + + align:start position:0% +this is our Mo our mapping of the moving + + + align:start position:0% +this is our Mo our mapping of the moving +object's motion from within our set of + + align:start position:0% +object's motion from within our set of + + + align:start position:0% +object's motion from within our set of +coordinates with respect to the + + align:start position:0% +coordinates with respect to the + + + align:start position:0% +coordinates with respect to the +coordinates of Mark our frame of rest + + align:start position:0% +coordinates of Mark our frame of rest + + + align:start position:0% +coordinates of Mark our frame of rest +and we're going to watch this moving + + align:start position:0% +and we're going to watch this moving + + + align:start position:0% +and we're going to watch this moving +train move through our coordinates okay + + align:start position:0% +train move through our coordinates okay + + + align:start position:0% +train move through our coordinates okay +now remember we have a partner who rides + + align:start position:0% +now remember we have a partner who rides + + + align:start position:0% +now remember we have a partner who rides +in the middle of the train again very + + align:start position:0% +in the middle of the train again very + + + align:start position:0% +in the middle of the train again very +much like what Einstein was describing + + align:start position:0% +much like what Einstein was describing + + + align:start position:0% +much like what Einstein was describing +so we have a colleague who's sitting in + + align:start position:0% +so we have a colleague who's sitting in + + + align:start position:0% +so we have a colleague who's sitting in +the middle of the train she knows she's + + align:start position:0% +the middle of the train she knows she's + + + align:start position:0% +the middle of the train she knows she's +exactly equal distance from the front to + + align:start position:0% +exactly equal distance from the front to + + + align:start position:0% +exactly equal distance from the front to +the back of the train + + align:start position:0% +the back of the train + + + align:start position:0% +the back of the train +she's asked friends on the train to + + align:start position:0% +she's asked friends on the train to + + + align:start position:0% +she's asked friends on the train to +shine their lanterns toward her and + + align:start position:0% +shine their lanterns toward her and + + + align:start position:0% +shine their lanterns toward her and +she'll uh she'll be able to determine + + align:start position:0% +she'll uh she'll be able to determine + + + align:start position:0% +she'll uh she'll be able to determine +whether or not her colleagues A and B + + align:start position:0% +whether or not her colleagues A and B + + + align:start position:0% +whether or not her colleagues A and B +shine their lanterns toward her + + align:start position:0% +shine their lanterns toward her + + + align:start position:0% +shine their lanterns toward her +simultaneously well light can only + + align:start position:0% +simultaneously well light can only + + + align:start position:0% +simultaneously well light can only +travel along 45 degrees on these + + align:start position:0% +travel along 45 degrees on these + + + align:start position:0% +travel along 45 degrees on these +diagrams for me or for her even on the + + align:start position:0% +diagrams for me or for her even on the + + + align:start position:0% +diagrams for me or for her even on the +moving train the light wave that's + + align:start position:0% +moving train the light wave that's + + + align:start position:0% +moving train the light wave that's +emitted from point B doesn't speed up it + + align:start position:0% +emitted from point B doesn't speed up it + + + align:start position:0% +emitted from point B doesn't speed up it +go it can only but go along a 45 degree + + align:start position:0% +go it can only but go along a 45 degree + + + align:start position:0% +go it can only but go along a 45 degree +angle that's the that's the real force + + align:start position:0% +angle that's the that's the real force + + + align:start position:0% +angle that's the that's the real force +of Einstein's second postulate likewise + + align:start position:0% +of Einstein's second postulate likewise + + + align:start position:0% +of Einstein's second postulate likewise +the light wave that's emitted from point + + align:start position:0% +the light wave that's emitted from point + + + align:start position:0% +the light wave that's emitted from point +B can only travel at the speed of light + + align:start position:0% +B can only travel at the speed of light + + + align:start position:0% +B can only travel at the speed of light +so in my coordinates as much as in my + + align:start position:0% +so in my coordinates as much as in my + + + align:start position:0% +so in my coordinates as much as in my +colleague's coordinates on the train + + align:start position:0% +colleague's coordinates on the train + + + align:start position:0% +colleague's coordinates on the train +those light waves must travel at 45 + + align:start position:0% +those light waves must travel at 45 + + + align:start position:0% +those light waves must travel at 45 +degree lines at the constant speed of + + align:start position:0% +degree lines at the constant speed of + + + align:start position:0% +degree lines at the constant speed of +light + + align:start position:0% +light + + + align:start position:0% +light +so our colleague who's moving on this + + align:start position:0% +so our colleague who's moving on this + + + align:start position:0% +so our colleague who's moving on this +train sitting in the middle she receives + + align:start position:0% +train sitting in the middle she receives + + + align:start position:0% +train sitting in the middle she receives +the light beams from point A and point B + + align:start position:0% +the light beams from point A and point B + + + align:start position:0% +the light beams from point A and point B +at the same time so now she knows those + + align:start position:0% +at the same time so now she knows those + + + align:start position:0% +at the same time so now she knows those +in Mission events must have been + + align:start position:0% +in Mission events must have been + + + align:start position:0% +in Mission events must have been +simultaneous how could they not have + + align:start position:0% +simultaneous how could they not have + + + align:start position:0% +simultaneous how could they not have +been she's in equal distance the light + + align:start position:0% +been she's in equal distance the light + + + align:start position:0% +been she's in equal distance the light +waves couldn't have either sped up or + + align:start position:0% +waves couldn't have either sped up or + + + align:start position:0% +waves couldn't have either sped up or +slowed down so therefore all the points + + align:start position:0% +slowed down so therefore all the points + + + align:start position:0% +slowed down so therefore all the points +along this new lie we can call the X + + align:start position:0% +along this new lie we can call the X + + + align:start position:0% +along this new lie we can call the X +Prime axis all those events were occur + + align:start position:0% +Prime axis all those events were occur + + + align:start position:0% +Prime axis all those events were occur +along a line of simultaneity for her in + + align:start position:0% +along a line of simultaneity for her in + + + align:start position:0% +along a line of simultaneity for her in +the moving train she knows exactly how + + align:start position:0% +the moving train she knows exactly how + + + align:start position:0% +the moving train she knows exactly how +to establish which events are + + align:start position:0% +to establish which events are + + + align:start position:0% +to establish which events are +simultaneous she can take advantage of + + align:start position:0% +simultaneous she can take advantage of + + + align:start position:0% +simultaneous she can take advantage of +light waves they travel at a universal + + align:start position:0% +light waves they travel at a universal + + + align:start position:0% +light waves they travel at a universal +speed + + align:start position:0% +speed + + + align:start position:0% +speed +it just turns out that what events are + + align:start position:0% +it just turns out that what events are + + + align:start position:0% +it just turns out that what events are +simultaneous for her no longer Maps the + + align:start position:0% +simultaneous for her no longer Maps the + + + align:start position:0% +simultaneous for her no longer Maps the +set of events that are simultaneous for + + align:start position:0% +set of events that are simultaneous for + + + align:start position:0% +set of events that are simultaneous for +us she has a different set of lines of + + align:start position:0% +us she has a different set of lines of + + + align:start position:0% +us she has a different set of lines of +simultaneity and minkowski was saying in + + align:start position:0% +simultaneity and minkowski was saying in + + + align:start position:0% +simultaneity and minkowski was saying in +effect you idiot Einstein it's just a + + align:start position:0% +effect you idiot Einstein it's just a + + + align:start position:0% +effect you idiot Einstein it's just a +coordinate rotation you're just + + align:start position:0% +coordinate rotation you're just + + + align:start position:0% +coordinate rotation you're just +establishing a new set of coordinates + + align:start position:0% +establishing a new set of coordinates + + + align:start position:0% +establishing a new set of coordinates +like any student of geometry should be + + align:start position:0% +like any student of geometry should be + + + align:start position:0% +like any student of geometry should be +able to do he said it only slightly more + + align:start position:0% +able to do he said it only slightly more + + + align:start position:0% +able to do he said it only slightly more +nicely in his published article + + align:start position:0% +nicely in his published article + + + align:start position:0% +nicely in his published article +meanwhile the T Prime axis is nothing + + align:start position:0% +meanwhile the T Prime axis is nothing + + + align:start position:0% +meanwhile the T Prime axis is nothing +other than the world line of the zero + + align:start position:0% +other than the world line of the zero + + + align:start position:0% +other than the world line of the zero +point of space for the moving uh moving + + align:start position:0% +point of space for the moving uh moving + + + align:start position:0% +point of space for the moving uh moving +Observer that is to say it's the world + + align:start position:0% +Observer that is to say it's the world + + + align:start position:0% +Observer that is to say it's the world +line of the back of the Train the origin + + align:start position:0% +line of the back of the Train the origin + + + align:start position:0% +line of the back of the Train the origin +point of her coordinates is say the back + + align:start position:0% +point of her coordinates is say the back + + + align:start position:0% +point of her coordinates is say the back +of the train X Prime equals zero she can + + align:start position:0% +of the train X Prime equals zero she can + + + align:start position:0% +of the train X Prime equals zero she can +measure any distance she wants with + + align:start position:0% +measure any distance she wants with + + + align:start position:0% +measure any distance she wants with +reference to the back of the train right + + align:start position:0% +reference to the back of the train right + + + align:start position:0% +reference to the back of the train right +she's moving with the train she can + + align:start position:0% +she's moving with the train she can + + + align:start position:0% +she's moving with the train she can +always lay out meter sticks and measure + + align:start position:0% +always lay out meter sticks and measure + + + align:start position:0% +always lay out meter sticks and measure +how far the front of the train is from + + align:start position:0% +how far the front of the train is from + + + align:start position:0% +how far the front of the train is from +the back so the origin the spatial + + align:start position:0% +the back so the origin the spatial + + + align:start position:0% +the back so the origin the spatial +origin of her coordinates is the back of + + align:start position:0% +origin of her coordinates is the back of + + + align:start position:0% +origin of her coordinates is the back of +the train how does that move through + + align:start position:0% +the train how does that move through + + + align:start position:0% +the train how does that move through +space and time that just put that just + + align:start position:0% +space and time that just put that just + + + align:start position:0% +space and time that just put that just +Becomes Her T Prime axis much as our + + align:start position:0% +Becomes Her T Prime axis much as our + + + align:start position:0% +Becomes Her T Prime axis much as our +location of the point x equals zero as + + align:start position:0% +location of the point x equals zero as + + + align:start position:0% +location of the point x equals zero as +it just sits still and moves through + + align:start position:0% +it just sits still and moves through + + + align:start position:0% +it just sits still and moves through +time that Maps out for us the t-axis + + align:start position:0% +time that Maps out for us the t-axis + + + align:start position:0% +time that Maps out for us the t-axis +the next thing minkowski showed very + + align:start position:0% +the next thing minkowski showed very + + + align:start position:0% +the next thing minkowski showed very +very uh very easily for him as a + + align:start position:0% +very uh very easily for him as a + + + align:start position:0% +very uh very easily for him as a +geometer is that the angle between the X + + align:start position:0% +geometer is that the angle between the X + + + align:start position:0% +geometer is that the angle between the X +and the X Prime axis some angle Theta is + + align:start position:0% +and the X Prime axis some angle Theta is + + + align:start position:0% +and the X Prime axis some angle Theta is +exactly the same angle as that between + + align:start position:0% +exactly the same angle as that between + + + align:start position:0% +exactly the same angle as that between +the T and the T Prime axis in fact that + + align:start position:0% +the T and the T Prime axis in fact that + + + align:start position:0% +the T and the T Prime axis in fact that +angle is directly related to this ratio + + align:start position:0% +angle is directly related to this ratio + + + align:start position:0% +angle is directly related to this ratio +V over C So the faster the relative + + align:start position:0% +V over C So the faster the relative + + + align:start position:0% +V over C So the faster the relative +motion between us and the Train the more + + align:start position:0% +motion between us and the Train the more + + + align:start position:0% +motion between us and the Train the more +steeply these lines are inclined the + + align:start position:0% +steeply these lines are inclined the + + + align:start position:0% +steeply these lines are inclined the +larger the angle as the relative speed V + + align:start position:0% +larger the angle as the relative speed V + + + align:start position:0% +larger the angle as the relative speed V +Rises with respect to that constant + + align:start position:0% +Rises with respect to that constant + + + align:start position:0% +Rises with respect to that constant +Universal speed the speed of light this + + align:start position:0% +Universal speed the speed of light this + + + align:start position:0% +Universal speed the speed of light this +angle becomes larger the X Prime axis + + align:start position:0% +angle becomes larger the X Prime axis + + + align:start position:0% +angle becomes larger the X Prime axis +becomes tilted even more far away from X + + align:start position:0% +becomes tilted even more far away from X + + + align:start position:0% +becomes tilted even more far away from X +the T Prime axis gets tilted even more + + align:start position:0% +the T Prime axis gets tilted even more + + + align:start position:0% +the T Prime axis gets tilted even more +inward away from T but all we're doing + + align:start position:0% +inward away from T but all we're doing + + + align:start position:0% +inward away from T but all we're doing +is establishing a new set of axes with + + align:start position:0% +is establishing a new set of axes with + + + align:start position:0% +is establishing a new set of axes with +respect to which we can mark the motion + + align:start position:0% +respect to which we can mark the motion + + + align:start position:0% +respect to which we can mark the motion +of objects through space and time + + align:start position:0% +of objects through space and time + + + align:start position:0% +of objects through space and time +according to the geometer hermannkowski + + align:start position:0% +according to the geometer hermannkowski + + + align:start position:0% +according to the geometer hermannkowski +so now we come to some of these strange + + align:start position:0% +so now we come to some of these strange + + + align:start position:0% +so now we come to some of these strange +sounding ideas that Einstein again had + + align:start position:0% +sounding ideas that Einstein again had + + + align:start position:0% +sounding ideas that Einstein again had +kind of belabored as far as minkowski is + + align:start position:0% +kind of belabored as far as minkowski is + + + align:start position:0% +kind of belabored as far as minkowski is +concerned Einstein belabored with all + + align:start position:0% +concerned Einstein belabored with all + + + align:start position:0% +concerned Einstein belabored with all +this kind of lengthy discussion of kind + + align:start position:0% +this kind of lengthy discussion of kind + + + align:start position:0% +this kind of lengthy discussion of kind +of Eric's mock inspired you know uh + + align:start position:0% +of Eric's mock inspired you know uh + + + align:start position:0% +of Eric's mock inspired you know uh +measurement procedures Mankowski says + + align:start position:0% +measurement procedures Mankowski says + + + align:start position:0% +measurement procedures Mankowski says +it's just more geometry let's take the + + align:start position:0% +it's just more geometry let's take the + + + align:start position:0% +it's just more geometry let's take the +example of length contraction we all + + align:start position:0% +example of length contraction we all + + + align:start position:0% +example of length contraction we all +agree the procedure for measuring + + align:start position:0% +agree the procedure for measuring + + + align:start position:0% +agree the procedure for measuring +lengths is to measure the location of + + align:start position:0% +lengths is to measure the location of + + + align:start position:0% +lengths is to measure the location of +the front of the object and the back of + + align:start position:0% +the front of the object and the back of + + + align:start position:0% +the front of the object and the back of +the object at the same time and then + + align:start position:0% +the object at the same time and then + + + align:start position:0% +the object at the same time and then +take the difference okay + + align:start position:0% +take the difference okay + + + align:start position:0% +take the difference okay +so we measure the length of the train to + + align:start position:0% +so we measure the length of the train to + + + align:start position:0% +so we measure the length of the train to +be this length I've called L Prime we + + align:start position:0% +be this length I've called L Prime we + + + align:start position:0% +be this length I've called L Prime we +have our friend at the back of the train + + align:start position:0% +have our friend at the back of the train + + + align:start position:0% +have our friend at the back of the train +at position a we have our friend at the + + align:start position:0% +at position a we have our friend at the + + + align:start position:0% +at position a we have our friend at the +front of the train at position B Prime + + align:start position:0% +front of the train at position B Prime + + + align:start position:0% +front of the train at position B Prime +we know those are simultaneous because + + align:start position:0% +we know those are simultaneous because + + + align:start position:0% +we know those are simultaneous because +they lie along a line of simultaneous + + align:start position:0% +they lie along a line of simultaneous + + + align:start position:0% +they lie along a line of simultaneous +for us or a little bit more kind of uh + + align:start position:0% +for us or a little bit more kind of uh + + + align:start position:0% +for us or a little bit more kind of uh +concretely both the event a and the + + align:start position:0% +concretely both the event a and the + + + align:start position:0% +concretely both the event a and the +event B Prime share the coordinate T + + align:start position:0% +event B Prime share the coordinate T + + + align:start position:0% +event B Prime share the coordinate T +equals zero they have the same time + + align:start position:0% +equals zero they have the same time + + + align:start position:0% +equals zero they have the same time +coordinate in our coordinate system in + + align:start position:0% +coordinate in our coordinate system in + + + align:start position:0% +coordinate in our coordinate system in +our reference frame they lie along a + + align:start position:0% +our reference frame they lie along a + + + align:start position:0% +our reference frame they lie along a +line of simultaneity so we've therefore + + align:start position:0% +line of simultaneity so we've therefore + + + align:start position:0% +line of simultaneity so we've therefore +marked the position along the x-axis of + + align:start position:0% +marked the position along the x-axis of + + + align:start position:0% +marked the position along the x-axis of +the front of the train and the back of + + align:start position:0% +the front of the train and the back of + + + align:start position:0% +the front of the train and the back of +the train at the same time in our + + align:start position:0% +the train at the same time in our + + + align:start position:0% +the train at the same time in our +reference frame now we can just take the + + align:start position:0% +reference frame now we can just take the + + + align:start position:0% +reference frame now we can just take the +difference subtract the location of this + + align:start position:0% +difference subtract the location of this + + + align:start position:0% +difference subtract the location of this +point B Prime along the x-axis subtract + + align:start position:0% +point B Prime along the x-axis subtract + + + align:start position:0% +point B Prime along the x-axis subtract +it from the origin of a that's our + + align:start position:0% +it from the origin of a that's our + + + align:start position:0% +it from the origin of a that's our +length of trade front and back same time + + align:start position:0% +length of trade front and back same time + + + align:start position:0% +length of trade front and back same time +length L Prime meanwhile for our friend + + align:start position:0% +length L Prime meanwhile for our friend + + + align:start position:0% +length L Prime meanwhile for our friend +who's riding along the train + + align:start position:0% +who's riding along the train + + + align:start position:0% +who's riding along the train +she knows exactly which events are + + align:start position:0% +she knows exactly which events are + + + align:start position:0% +she knows exactly which events are +simultaneous because she can have her + + align:start position:0% +simultaneous because she can have her + + + align:start position:0% +simultaneous because she can have her +friends test this with the exchange of + + align:start position:0% +friends test this with the exchange of + + + align:start position:0% +friends test this with the exchange of +light signals and she knows very very + + align:start position:0% +light signals and she knows very very + + + align:start position:0% +light signals and she knows very very +clearly that the events A and B are + + align:start position:0% +clearly that the events A and B are + + + align:start position:0% +clearly that the events A and B are +simultaneous for her reference frame A + + align:start position:0% +simultaneous for her reference frame A + + + align:start position:0% +simultaneous for her reference frame A +and B lie along a shared line of + + align:start position:0% +and B lie along a shared line of + + + align:start position:0% +and B lie along a shared line of +simultaneous just not our line of + + align:start position:0% +simultaneous just not our line of + + + align:start position:0% +simultaneous just not our line of +simultaneity so her friend of the front + + align:start position:0% +simultaneity so her friend of the front + + + align:start position:0% +simultaneity so her friend of the front +of the train can mark that location her + + align:start position:0% +of the train can mark that location her + + + align:start position:0% +of the train can mark that location her +friend at the back of the train can mark + + align:start position:0% +friend at the back of the train can mark + + + align:start position:0% +friend at the back of the train can mark +that location we know they're doing it + + align:start position:0% +that location we know they're doing it + + + align:start position:0% +that location we know they're doing it +at the same time in the moving reference + + align:start position:0% +at the same time in the moving reference + + + align:start position:0% +at the same time in the moving reference +frame take the difference is the + + align:start position:0% +frame take the difference is the + + + align:start position:0% +frame take the difference is the +difference l which as you can see now + + align:start position:0% +difference l which as you can see now + + + align:start position:0% +difference l which as you can see now +just trivially is longer than L Prime + + align:start position:0% +just trivially is longer than L Prime + + + align:start position:0% +just trivially is longer than L Prime +so what Einstein called Edward Frank for + + align:start position:0% +so what Einstein called Edward Frank for + + + align:start position:0% +so what Einstein called Edward Frank for +that matter Lorenzo called length + + align:start position:0% +that matter Lorenzo called length + + + align:start position:0% +that matter Lorenzo called length +contraction our measurement of the + + align:start position:0% +contraction our measurement of the + + + align:start position:0% +contraction our measurement of the +moving object is short compared to the + + align:start position:0% +moving object is short compared to the + + + align:start position:0% +moving object is short compared to the +measurement conducted by someone moving + + align:start position:0% +measurement conducted by someone moving + + + align:start position:0% +measurement conducted by someone moving +with that object L Prime is demonstrably + + align:start position:0% +with that object L Prime is demonstrably + + + align:start position:0% +with that object L Prime is demonstrably +shorter than L and minkowski's has an + + align:start position:0% +shorter than L and minkowski's has an + + + align:start position:0% +shorter than L and minkowski's has an +effect of course it is we're just + + align:start position:0% +effect of course it is we're just + + + align:start position:0% +effect of course it is we're just +projecting our measurements onto + + align:start position:0% +projecting our measurements onto + + + align:start position:0% +projecting our measurements onto +different sets of axes we are geometers + + align:start position:0% +different sets of axes we are geometers + + + align:start position:0% +different sets of axes we are geometers +we reckon objects with certain sets of + + align:start position:0% +we reckon objects with certain sets of + + + align:start position:0% +we reckon objects with certain sets of +coordinates and we just happen to have + + align:start position:0% +coordinates and we just happen to have + + + align:start position:0% +coordinates and we just happen to have +different coordinates that we with which + + align:start position:0% +different coordinates that we with which + + + align:start position:0% +different coordinates that we with which +we're making sense of the world + + align:start position:0% +we're making sense of the world + + + align:start position:0% +we're making sense of the world +it doesn't just derive the qualitative + + align:start position:0% +it doesn't just derive the qualitative + + + align:start position:0% +it doesn't just derive the qualitative +phenomenon of length contraction he gets + + align:start position:0% +phenomenon of length contraction he gets + + + align:start position:0% +phenomenon of length contraction he gets +exactly the answer that both Einstein + + align:start position:0% +exactly the answer that both Einstein + + + align:start position:0% +exactly the answer that both Einstein +and Lorenzo gotten even though they had + + align:start position:0% +and Lorenzo gotten even though they had + + + align:start position:0% +and Lorenzo gotten even though they had +had very different forms of argument he + + align:start position:0% +had very different forms of argument he + + + align:start position:0% +had very different forms of argument he +even gets the exact form of this gamma + + align:start position:0% +even gets the exact form of this gamma + + + align:start position:0% +even gets the exact form of this gamma +because as you may remember the angle + + align:start position:0% +because as you may remember the angle + + + align:start position:0% +because as you may remember the angle +here between x and x Prime is directly + + align:start position:0% +here between x and x Prime is directly + + + align:start position:0% +here between x and x Prime is directly +related to V over c as is the factored + + align:start position:0% +related to V over c as is the factored + + + align:start position:0% +related to V over c as is the factored +gamma a few lines of algebra not very + + align:start position:0% +gamma a few lines of algebra not very + + + align:start position:0% +gamma a few lines of algebra not very +hard to see the relationship between + + align:start position:0% +hard to see the relationship between + + + align:start position:0% +hard to see the relationship between +this line segment and that line segment + + align:start position:0% +this line segment and that line segment + + + align:start position:0% +this line segment and that line segment +what's important again to underscore is + + align:start position:0% +what's important again to underscore is + + + align:start position:0% +what's important again to underscore is +not the algebra I'm confident we can all + + align:start position:0% +not the algebra I'm confident we can all + + + align:start position:0% +not the algebra I'm confident we can all +do that is to say that for minkowski + + align:start position:0% +do that is to say that for minkowski + + + align:start position:0% +do that is to say that for minkowski +this is not about The Ether it's not + + align:start position:0% +this is not about The Ether it's not + + + align:start position:0% +this is not about The Ether it's not +about + + align:start position:0% +about + + + align:start position:0% +about +um Mahi and observations that are + + align:start position:0% +um Mahi and observations that are + + + align:start position:0% +um Mahi and observations that are +subject to positive experience this is + + align:start position:0% +subject to positive experience this is + + + align:start position:0% +subject to positive experience this is +just geometry as we transform between + + align:start position:0% +just geometry as we transform between + + + align:start position:0% +just geometry as we transform between +different coordinate systems and you can + + align:start position:0% +different coordinate systems and you can + + + align:start position:0% +different coordinate systems and you can +almost hear him saying no da to Einstein + + align:start position:0% +almost hear him saying no da to Einstein + + + align:start position:0% +almost hear him saying no da to Einstein +who'd cut all his classes + + align:start position:0% +who'd cut all his classes + + + align:start position:0% +who'd cut all his classes +Mankowski goes on in this article uh + + align:start position:0% +Mankowski goes on in this article uh + + + align:start position:0% +Mankowski goes on in this article uh +first worked out in 1907. using these + + align:start position:0% +first worked out in 1907. using these + + + align:start position:0% +first worked out in 1907. using these +space-time diagrams he then shows that + + align:start position:0% +space-time diagrams he then shows that + + + align:start position:0% +space-time diagrams he then shows that +the full lorentz transformation was + + align:start position:0% +the full lorentz transformation was + + + align:start position:0% +the full lorentz transformation was +nothing but geometry remember to + + align:start position:0% +nothing but geometry remember to + + + align:start position:0% +nothing but geometry remember to +Mankowski everything was geometry this + + align:start position:0% +Mankowski everything was geometry this + + + align:start position:0% +Mankowski everything was geometry this +was just a rotation in space-time now to + + align:start position:0% +was just a rotation in space-time now to + + + align:start position:0% +was just a rotation in space-time now to +warm up for that again we'll do + + align:start position:0% +warm up for that again we'll do + + + align:start position:0% +warm up for that again we'll do +something probably a little bit familiar + + align:start position:0% +something probably a little bit familiar + + + align:start position:0% +something probably a little bit familiar +to start we'll talk about just an + + align:start position:0% +to start we'll talk about just an + + + align:start position:0% +to start we'll talk about just an +ordinary uh X Y plane two directions of + + align:start position:0% +ordinary uh X Y plane two directions of + + + align:start position:0% +ordinary uh X Y plane two directions of +space that are perpendicular to each + + align:start position:0% +space that are perpendicular to each + + + align:start position:0% +space that are perpendicular to each +other the Cartesian plane or if you like + + align:start position:0% +other the Cartesian plane or if you like + + + align:start position:0% +other the Cartesian plane or if you like +the euclidean plane we can lay out our + + align:start position:0% +the euclidean plane we can lay out our + + + align:start position:0% +the euclidean plane we can lay out our +coordinates X will be our horizontal + + align:start position:0% +coordinates X will be our horizontal + + + align:start position:0% +coordinates X will be our horizontal +axis y is at right angles heading up the + + align:start position:0% +axis y is at right angles heading up the + + + align:start position:0% +axis y is at right angles heading up the +page these are two directions of space + + align:start position:0% +page these are two directions of space + + + align:start position:0% +page these are two directions of space +we can identify some points in the plane + + align:start position:0% +we can identify some points in the plane + + + align:start position:0% +we can identify some points in the plane +we'll call it Point P we can label the + + align:start position:0% +we'll call it Point P we can label the + + + align:start position:0% +we'll call it Point P we can label the +location of that point in our coordinate + + align:start position:0% +location of that point in our coordinate + + + align:start position:0% +location of that point in our coordinate +system we'll project what that means + + align:start position:0% +system we'll project what that means + + + align:start position:0% +system we'll project what that means +really is we're projecting the location + + align:start position:0% +really is we're projecting the location + + + align:start position:0% +really is we're projecting the location +of Point P onto our perpendicular axes + + align:start position:0% +of Point P onto our perpendicular axes + + + align:start position:0% +of Point P onto our perpendicular axes +so we label the x coordinate of Point p + + align:start position:0% +so we label the x coordinate of Point p + + + align:start position:0% +so we label the x coordinate of Point p +as its projection along the P excuse me + + align:start position:0% +as its projection along the P excuse me + + + align:start position:0% +as its projection along the P excuse me +along the x-axis it has some value X1 we + + align:start position:0% +along the x-axis it has some value X1 we + + + align:start position:0% +along the x-axis it has some value X1 we +identified the location of Point P the + + align:start position:0% +identified the location of Point P the + + + align:start position:0% +identified the location of Point P the +projection along the y-axis that's it's + + align:start position:0% +projection along the y-axis that's it's + + + align:start position:0% +projection along the y-axis that's it's +a y coordinate y one fine + + align:start position:0% +a y coordinate y one fine + + + align:start position:0% +a y coordinate y one fine +now we all know even Einstein knew we're + + align:start position:0% +now we all know even Einstein knew we're + + + align:start position:0% +now we all know even Einstein knew we're +allowed to rotate our coordinate systems + + align:start position:0% +allowed to rotate our coordinate systems + + + align:start position:0% +allowed to rotate our coordinate systems +in the X Y plane what if a friend of + + align:start position:0% +in the X Y plane what if a friend of + + + align:start position:0% +in the X Y plane what if a friend of +ours had used an inclined set of + + align:start position:0% +ours had used an inclined set of + + + align:start position:0% +ours had used an inclined set of +coordinates X Prime and Y Prime that are + + align:start position:0% +coordinates X Prime and Y Prime that are + + + align:start position:0% +coordinates X Prime and Y Prime that are +rotated by some fixed angle away from + + align:start position:0% +rotated by some fixed angle away from + + + align:start position:0% +rotated by some fixed angle away from +our original coordinates + + align:start position:0% +our original coordinates + + + align:start position:0% +our original coordinates +the point P hasn't moved all we've done + + align:start position:0% +the point P hasn't moved all we've done + + + align:start position:0% +the point P hasn't moved all we've done +is change the labels we assign to the + + align:start position:0% +is change the labels we assign to the + + + align:start position:0% +is change the labels we assign to the +coordinates in our new coordinate system + + align:start position:0% +coordinates in our new coordinate system + + + align:start position:0% +coordinates in our new coordinate system +in the rotated coordinates the same + + align:start position:0% +in the rotated coordinates the same + + + align:start position:0% +in the rotated coordinates the same +point P which itself hasn't moved is + + align:start position:0% +point P which itself hasn't moved is + + + align:start position:0% +point P which itself hasn't moved is +assigned a different value of its X + + align:start position:0% +assigned a different value of its X + + + align:start position:0% +assigned a different value of its X +Prime coordinate projecting now to the + + align:start position:0% +Prime coordinate projecting now to the + + + align:start position:0% +Prime coordinate projecting now to the +new axis and a different value is y + + align:start position:0% +new axis and a different value is y + + + align:start position:0% +new axis and a different value is y +Prime coordinate projecting to the new y + + align:start position:0% +Prime coordinate projecting to the new y + + + align:start position:0% +Prime coordinate projecting to the new y +axis + + align:start position:0% +axis + + + align:start position:0% +axis +these are related quite + + align:start position:0% +these are related quite + + + align:start position:0% +these are related quite +straightforwardly by a rotation matrix + + align:start position:0% +straightforwardly by a rotation matrix + + + align:start position:0% +straightforwardly by a rotation matrix +by uh if we want to do little fancy + + align:start position:0% +by uh if we want to do little fancy + + + align:start position:0% +by uh if we want to do little fancy +paths we could say it's a a one + + align:start position:0% +paths we could say it's a a one + + + align:start position:0% +paths we could say it's a a one +parameter group + + align:start position:0% +parameter group + + + align:start position:0% +parameter group +the rotation in two Dimensions but it's + + align:start position:0% +the rotation in two Dimensions but it's + + + align:start position:0% +the rotation in two Dimensions but it's +just a set of Sines and cosines to take + + align:start position:0% +just a set of Sines and cosines to take + + + align:start position:0% +just a set of Sines and cosines to take +into account how the X and X Prime axes + + align:start position:0% +into account how the X and X Prime axes + + + align:start position:0% +into account how the X and X Prime axes +are related to each other by this angle + + align:start position:0% +are related to each other by this angle + + + align:start position:0% +are related to each other by this angle +Theta and the Y and Y Prime axis so it's + + align:start position:0% +Theta and the Y and Y Prime axis so it's + + + align:start position:0% +Theta and the Y and Y Prime axis so it's +actually very straightforward to relate + + align:start position:0% +actually very straightforward to relate + + + align:start position:0% +actually very straightforward to relate +the coordinate labels in one set of + + align:start position:0% +the coordinate labels in one set of + + + align:start position:0% +the coordinate labels in one set of +coordinates to those in the other + + align:start position:0% +coordinates to those in the other + + + align:start position:0% +coordinates to those in the other +nothing magic has happened we can see + + align:start position:0% +nothing magic has happened we can see + + + align:start position:0% +nothing magic has happened we can see +that what I had called X Prime was + + align:start position:0% +that what I had called X Prime was + + + align:start position:0% +that what I had called X Prime was +related to X in this very + + align:start position:0% +related to X in this very + + + align:start position:0% +related to X in this very +straightforward fashion taking into + + align:start position:0% +straightforward fashion taking into + + + align:start position:0% +straightforward fashion taking into +account + + align:start position:0% +account + + + align:start position:0% +account +um the different coordinate systems in + + align:start position:0% +um the different coordinate systems in + + + align:start position:0% +um the different coordinate systems in +their angle between them and likewise y + + align:start position:0% +their angle between them and likewise y + + + align:start position:0% +their angle between them and likewise y +Prime in terms of X and Y + + align:start position:0% +Prime in terms of X and Y + + + align:start position:0% +Prime in terms of X and Y +so Makowski says that's all that's + + align:start position:0% +so Makowski says that's all that's + + + align:start position:0% +so Makowski says that's all that's +happening with space-time diagrams as + + align:start position:0% +happening with space-time diagrams as + + + align:start position:0% +happening with space-time diagrams as +well now let's imagine some event in + + align:start position:0% +well now let's imagine some event in + + + align:start position:0% +well now let's imagine some event in +space time so now we're going back to + + align:start position:0% +space time so now we're going back to + + + align:start position:0% +space time so now we're going back to +these minkowski diagrams the spatial + + align:start position:0% +these minkowski diagrams the spatial + + + align:start position:0% +these minkowski diagrams the spatial +Direction runs along the horizontal axis + + align:start position:0% +Direction runs along the horizontal axis + + + align:start position:0% +Direction runs along the horizontal axis +the time Direction runs vertically we + + align:start position:0% +the time Direction runs vertically we + + + align:start position:0% +the time Direction runs vertically we +have some event that happens in space + + align:start position:0% +have some event that happens in space + + + align:start position:0% +have some event that happens in space +and time let's say we assigned to it a + + align:start position:0% +and time let's say we assigned to it a + + + align:start position:0% +and time let's say we assigned to it a +time that happened at 12 noon uh at my + + align:start position:0% +time that happened at 12 noon uh at my + + + align:start position:0% +time that happened at 12 noon uh at my +house right a spatial location okay + + align:start position:0% +house right a spatial location okay + + + align:start position:0% +house right a spatial location okay +there's some point + + align:start position:0% +there's some point + + + align:start position:0% +there's some point +Now The Observer on the train is going + + align:start position:0% +Now The Observer on the train is going + + + align:start position:0% +Now The Observer on the train is going +to label that exact same event + + align:start position:0% +to label that exact same event + + + align:start position:0% +to label that exact same event +but give it different coordinate values + + align:start position:0% +but give it different coordinate values + + + align:start position:0% +but give it different coordinate values +because her coordinate system is + + align:start position:0% +because her coordinate system is + + + align:start position:0% +because her coordinate system is +different the lines of simultaneity for + + align:start position:0% +different the lines of simultaneity for + + + align:start position:0% +different the lines of simultaneity for +her frame are different + + align:start position:0% +her frame are different + + + align:start position:0% +her frame are different +the world line of x equals zero for her + + align:start position:0% +the world line of x equals zero for her + + + align:start position:0% +the world line of x equals zero for her +is different so she has the X Prime T + + align:start position:0% +is different so she has the X Prime T + + + align:start position:0% +is different so she has the X Prime T +Prime coordinates she's still perfectly + + align:start position:0% +Prime coordinates she's still perfectly + + + align:start position:0% +Prime coordinates she's still perfectly +capable of labeling uh the event p and + + align:start position:0% +capable of labeling uh the event p and + + + align:start position:0% +capable of labeling uh the event p and +assigning to it values in her + + align:start position:0% +assigning to it values in her + + + align:start position:0% +assigning to it values in her +coordinates X1 Prime and T1 Prime and + + align:start position:0% +coordinates X1 Prime and T1 Prime and + + + align:start position:0% +coordinates X1 Prime and T1 Prime and +again remember the angle of inclination + + align:start position:0% +again remember the angle of inclination + + + align:start position:0% +again remember the angle of inclination +here is directly related to the relative + + align:start position:0% +here is directly related to the relative + + + align:start position:0% +here is directly related to the relative +speed between these two sets of chords + + align:start position:0% +speed between these two sets of chords + + + align:start position:0% +speed between these two sets of chords +these two reference frames + + align:start position:0% +these two reference frames + + + align:start position:0% +these two reference frames +moreover what Lorenz had had derived + + align:start position:0% +moreover what Lorenz had had derived + + + align:start position:0% +moreover what Lorenz had had derived +because of the kind of what he assumed + + align:start position:0% +because of the kind of what he assumed + + + align:start position:0% +because of the kind of what he assumed +to be the elastic forces of an ether + + align:start position:0% +to be the elastic forces of an ether + + + align:start position:0% +to be the elastic forces of an ether +acting on the molecules what Einstein + + align:start position:0% +acting on the molecules what Einstein + + + align:start position:0% +acting on the molecules what Einstein +had derived quite differently by + + align:start position:0% +had derived quite differently by + + + align:start position:0% +had derived quite differently by +thinking about uh the relative + + align:start position:0% +thinking about uh the relative + + + align:start position:0% +thinking about uh the relative +relativity of simultaneity minkowski + + align:start position:0% +relativity of simultaneity minkowski + + + align:start position:0% +relativity of simultaneity minkowski +says is just the set of rules for making + + align:start position:0% +says is just the set of rules for making + + + align:start position:0% +says is just the set of rules for making +rotations in this only slightly more + + align:start position:0% +rotations in this only slightly more + + + align:start position:0% +rotations in this only slightly more +complicated geometrical space it's still + + align:start position:0% +complicated geometrical space it's still + + + align:start position:0% +complicated geometrical space it's still +basically like making rotations in the X + + align:start position:0% +basically like making rotations in the X + + + align:start position:0% +basically like making rotations in the X +Y plane we have again to be fancy pants + + align:start position:0% +Y plane we have again to be fancy pants + + + align:start position:0% +Y plane we have again to be fancy pants +a one parameter family of rotations the + + align:start position:0% +a one parameter family of rotations the + + + align:start position:0% +a one parameter family of rotations the +one parameter that changes now is the + + align:start position:0% +one parameter that changes now is the + + + align:start position:0% +one parameter that changes now is the +relative speed V or if you like the + + align:start position:0% +relative speed V or if you like the + + + align:start position:0% +relative speed V or if you like the +ratio of V over C but of course C is a + + align:start position:0% +ratio of V over C but of course C is a + + + align:start position:0% +ratio of V over C but of course C is a +universal constant the only thing that + + align:start position:0% +universal constant the only thing that + + + align:start position:0% +universal constant the only thing that +really varies here is there is a speed + + align:start position:0% +really varies here is there is a speed + + + align:start position:0% +really varies here is there is a speed +Little V we have some other set of rules + + align:start position:0% +Little V we have some other set of rules + + + align:start position:0% +Little V we have some other set of rules +these take the place of our kind of + + align:start position:0% +these take the place of our kind of + + + align:start position:0% +these take the place of our kind of +Sines and cosines of the relative angle + + align:start position:0% +Sines and cosines of the relative angle + + + align:start position:0% +Sines and cosines of the relative angle +so once again we can now trivially + + align:start position:0% +so once again we can now trivially + + + align:start position:0% +so once again we can now trivially +geometrically relate the labels that the + + align:start position:0% +geometrically relate the labels that the + + + align:start position:0% +geometrically relate the labels that the +moving uh the person on the moving train + + align:start position:0% +moving uh the person on the moving train + + + align:start position:0% +moving uh the person on the moving train +had assigned to the same event P relate + + align:start position:0% +had assigned to the same event P relate + + + align:start position:0% +had assigned to the same event P relate +those to the labels that we assigned + + align:start position:0% +those to the labels that we assigned + + + align:start position:0% +those to the labels that we assigned +standing still on the station platform + + align:start position:0% +standing still on the station platform + + + align:start position:0% +standing still on the station platform +he gets precisely the Lorenz + + align:start position:0% +he gets precisely the Lorenz + + + align:start position:0% +he gets precisely the Lorenz +transformation not because of the ether + + align:start position:0% +transformation not because of the ether + + + align:start position:0% +transformation not because of the ether +not because of Einstein's um uh + + align:start position:0% +not because of Einstein's um uh + + + align:start position:0% +not because of Einstein's um uh +arguments about sort of how we perform + + align:start position:0% +arguments about sort of how we perform + + + align:start position:0% +arguments about sort of how we perform +measurements but because he's just a + + align:start position:0% +measurements but because he's just a + + + align:start position:0% +measurements but because he's just a +geometer making + + align:start position:0% +geometer making + + + align:start position:0% +geometer making +um rotations in a particular kind of + + align:start position:0% +um rotations in a particular kind of + + + align:start position:0% +um rotations in a particular kind of +two-dimensional space + + align:start position:0% +two-dimensional space + + + align:start position:0% +two-dimensional space +so to minkowski the Lorenz + + align:start position:0% +so to minkowski the Lorenz + + + align:start position:0% +so to minkowski the Lorenz +transformation itself was nothing but + + align:start position:0% +transformation itself was nothing but + + + align:start position:0% +transformation itself was nothing but +geometric rotations and space-time again + + align:start position:0% +geometric rotations and space-time again + + + align:start position:0% +geometric rotations and space-time again +so not surprising since we know + + align:start position:0% +so not surprising since we know + + + align:start position:0% +so not surprising since we know +minkowski is a geometer above all okay + + align:start position:0% +minkowski is a geometer above all okay + + + align:start position:0% +minkowski is a geometer above all okay +now this gives them something that's + + align:start position:0% +now this gives them something that's + + + align:start position:0% +now this gives them something that's +actually new he's no longer just + + align:start position:0% +actually new he's no longer just + + + align:start position:0% +actually new he's no longer just +rederiding stuff in a new way now we get + + align:start position:0% +rederiding stuff in a new way now we get + + + align:start position:0% +rederiding stuff in a new way now we get +stuff that neither lorentz nor Einstein + + align:start position:0% +stuff that neither lorentz nor Einstein + + + align:start position:0% +stuff that neither lorentz nor Einstein +had actually recognized or realized this + + align:start position:0% +had actually recognized or realized this + + + align:start position:0% +had actually recognized or realized this +next part comes really from minkowski + + align:start position:0% +next part comes really from minkowski + + + align:start position:0% +next part comes really from minkowski +taking geometry very seriously as he + + align:start position:0% +taking geometry very seriously as he + + + align:start position:0% +taking geometry very seriously as he +knew as a geometer even in ordinary X Y + + align:start position:0% +knew as a geometer even in ordinary X Y + + + align:start position:0% +knew as a geometer even in ordinary X Y +plane type of geometry when we we can + + align:start position:0% +plane type of geometry when we we can + + + align:start position:0% +plane type of geometry when we we can +perform rotations the coordinate labels + + align:start position:0% +perform rotations the coordinate labels + + + align:start position:0% +perform rotations the coordinate labels +of a given point will change but some + + align:start position:0% +of a given point will change but some + + + align:start position:0% +of a given point will change but some +quantities remain unchanged even under + + align:start position:0% +quantities remain unchanged even under + + + align:start position:0% +quantities remain unchanged even under +rotations for example the distance + + align:start position:0% +rotations for example the distance + + + align:start position:0% +rotations for example the distance +so what's the distance between the + + align:start position:0% +so what's the distance between the + + + align:start position:0% +so what's the distance between the +origin and my coordinates and the point + + align:start position:0% +origin and my coordinates and the point + + + align:start position:0% +origin and my coordinates and the point +P we'll call that distance D that + + align:start position:0% +P we'll call that distance D that + + + align:start position:0% +P we'll call that distance D that +doesn't change even if I change the + + align:start position:0% +doesn't change even if I change the + + + align:start position:0% +doesn't change even if I change the +labeling of my coordinates so when I + + align:start position:0% +labeling of my coordinates so when I + + + align:start position:0% +labeling of my coordinates so when I +rotate my some angle Theta + + align:start position:0% +rotate my some angle Theta + + + align:start position:0% +rotate my some angle Theta +I change the labeling the description of + + align:start position:0% +I change the labeling the description of + + + align:start position:0% +I change the labeling the description of +X and Y versus X Prime and Y Prime I + + align:start position:0% +X and Y versus X Prime and Y Prime I + + + align:start position:0% +X and Y versus X Prime and Y Prime I +didn't pick up the point p and move it + + align:start position:0% +didn't pick up the point p and move it + + + align:start position:0% +didn't pick up the point p and move it +further from the origin the distance + + align:start position:0% +further from the origin the distance + + + align:start position:0% +further from the origin the distance +between say the origin and point p is + + align:start position:0% +between say the origin and point p is + + + align:start position:0% +between say the origin and point p is +invariant under those rotations and + + align:start position:0% +invariant under those rotations and + + + align:start position:0% +invariant under those rotations and +again it'll take you about + + align:start position:0% +again it'll take you about + + + align:start position:0% +again it'll take you about +28 milliseconds to figure that out for + + align:start position:0% +28 milliseconds to figure that out for + + + align:start position:0% +28 milliseconds to figure that out for +the geometrical case just using you know + + align:start position:0% +the geometrical case just using you know + + + align:start position:0% +the geometrical case just using you know +sine squared theta plus cosine squared + + align:start position:0% +sine squared theta plus cosine squared + + + align:start position:0% +sine squared theta plus cosine squared +theta equals one use the usual + + align:start position:0% +theta equals one use the usual + + + align:start position:0% +theta equals one use the usual +trigonometric identity between these + + align:start position:0% +trigonometric identity between these + + + align:start position:0% +trigonometric identity between these +trigonometric functions and then it's + + align:start position:0% +trigonometric functions and then it's + + + align:start position:0% +trigonometric functions and then it's +very straightforward to see the distance + + align:start position:0% +very straightforward to see the distance + + + align:start position:0% +very straightforward to see the distance +is invariant even though the coordinate + + align:start position:0% +is invariant even though the coordinate + + + align:start position:0% +is invariant even though the coordinate +labels have changed under rotation + + align:start position:0% +labels have changed under rotation + + + align:start position:0% +labels have changed under rotation +that's what now becomes really new that + + align:start position:0% +that's what now becomes really new that + + + align:start position:0% +that's what now becomes really new that +minkowski pushes forward + + align:start position:0% +minkowski pushes forward + + + align:start position:0% +minkowski pushes forward +as as with the first real concrete + + align:start position:0% +as as with the first real concrete + + + align:start position:0% +as as with the first real concrete +Advantage as far as he's concerned of + + align:start position:0% +Advantage as far as he's concerned of + + + align:start position:0% +Advantage as far as he's concerned of +this geometrical approach there's a + + align:start position:0% +this geometrical approach there's a + + + align:start position:0% +this geometrical approach there's a +generalization of distance that + + align:start position:0% +generalization of distance that + + + align:start position:0% +generalization of distance that +minkowski introduces it comes to be + + align:start position:0% +minkowski introduces it comes to be + + + align:start position:0% +minkowski introduces it comes to be +called the space-time interval often + + align:start position:0% +called the space-time interval often + + + align:start position:0% +called the space-time interval often +abbreviated by the letter s it's like a + + align:start position:0% +abbreviated by the letter s it's like a + + + align:start position:0% +abbreviated by the letter s it's like a +version of distance for space time + + align:start position:0% +version of distance for space time + + + align:start position:0% +version of distance for space time +instead of only uh a spatial problem + + align:start position:0% +instead of only uh a spatial problem + + + align:start position:0% +instead of only uh a spatial problem +only space space so what is this space + + align:start position:0% +only space space so what is this space + + + align:start position:0% +only space space so what is this space +time interval that remains unchanged + + align:start position:0% +time interval that remains unchanged + + + align:start position:0% +time interval that remains unchanged +even though the coordinate labels might + + align:start position:0% +even though the coordinate labels might + + + align:start position:0% +even though the coordinate labels might +be switched onto these coordinate + + align:start position:0% +be switched onto these coordinate + + + align:start position:0% +be switched onto these coordinate +lorentz transformations so again we come + + align:start position:0% +lorentz transformations so again we come + + + align:start position:0% +lorentz transformations so again we come +back to this way to relate our x and t + + align:start position:0% +back to this way to relate our x and t + + + align:start position:0% +back to this way to relate our x and t +coordinate store X Prime and T Prime + + align:start position:0% +coordinate store X Prime and T Prime + + + align:start position:0% +coordinate store X Prime and T Prime +that's what mankowski's rederived from + + align:start position:0% +that's what mankowski's rederived from + + + align:start position:0% +that's what mankowski's rederived from +his rotation and now he shows using the + + align:start position:0% +his rotation and now he shows using the + + + align:start position:0% +his rotation and now he shows using the +definition of gamma that just for the + + align:start position:0% +definition of gamma that just for the + + + align:start position:0% +definition of gamma that just for the +exact same reason that + + align:start position:0% +exact same reason that + + + align:start position:0% +exact same reason that +the euclidean distance Little D in the + + align:start position:0% +the euclidean distance Little D in the + + + align:start position:0% +the euclidean distance Little D in the +previous example remains unchanged just + + align:start position:0% +previous example remains unchanged just + + + align:start position:0% +previous example remains unchanged just +because of the definitions of sine and + + align:start position:0% +because of the definitions of sine and + + + align:start position:0% +because of the definitions of sine and +cosine of a given angle given the + + align:start position:0% +cosine of a given angle given the + + + align:start position:0% +cosine of a given angle given the +definition of gamma that way of relating + + align:start position:0% +definition of gamma that way of relating + + + align:start position:0% +definition of gamma that way of relating +the kind of rotation the degree to which + + align:start position:0% +the kind of rotation the degree to which + + + align:start position:0% +the kind of rotation the degree to which +X Prime is inclined with respect to X we + + align:start position:0% +X Prime is inclined with respect to X we + + + align:start position:0% +X Prime is inclined with respect to X we +get an unavoidable um outcome that + + align:start position:0% +get an unavoidable um outcome that + + + align:start position:0% +get an unavoidable um outcome that +whether we had chosen to label the event + + align:start position:0% +whether we had chosen to label the event + + + align:start position:0% +whether we had chosen to label the event +p in our x and t coordinates or X Prime + + align:start position:0% +p in our x and t coordinates or X Prime + + + align:start position:0% +p in our x and t coordinates or X Prime +and T Prime coordinates the space time + + align:start position:0% +and T Prime coordinates the space time + + + align:start position:0% +and T Prime coordinates the space time +interval little s has remained unchanged + + align:start position:0% +interval little s has remained unchanged + + + align:start position:0% +interval little s has remained unchanged +there's a something that remains + + align:start position:0% +there's a something that remains + + + align:start position:0% +there's a something that remains +invariant even though our different + + align:start position:0% +invariant even though our different + + + align:start position:0% +invariant even though our different +descriptions of spatial spatial + + align:start position:0% +descriptions of spatial spatial + + + align:start position:0% +descriptions of spatial spatial +distances and temporal durations have + + align:start position:0% +distances and temporal durations have + + + align:start position:0% +distances and temporal durations have +changed + + align:start position:0% +changed + + + align:start position:0% +changed +so to minkowski this shows that really + + align:start position:0% +so to minkowski this shows that really + + + align:start position:0% +so to minkowski this shows that really +geometry in particular the geometry of + + align:start position:0% +geometry in particular the geometry of + + + align:start position:0% +geometry in particular the geometry of +space-time that dominkowski becomes the + + align:start position:0% +space-time that dominkowski becomes the + + + align:start position:0% +space-time that dominkowski becomes the +only thing that matters not The Ether + + align:start position:0% +only thing that matters not The Ether + + + align:start position:0% +only thing that matters not The Ether +not this kind of mock-like show me how I + + align:start position:0% +not this kind of mock-like show me how I + + + align:start position:0% +not this kind of mock-like show me how I +can uh you know taste it or measure or + + align:start position:0% +can uh you know taste it or measure or + + + align:start position:0% +can uh you know taste it or measure or +make it subject of positive experience + + align:start position:0% +make it subject of positive experience + + + align:start position:0% +make it subject of positive experience +it's this geometrical feature of + + align:start position:0% +it's this geometrical feature of + + + align:start position:0% +it's this geometrical feature of +space-time and in particular not space + + align:start position:0% +space-time and in particular not space + + + align:start position:0% +space-time and in particular not space +and time separately it's actually + + align:start position:0% +and time separately it's actually + + + align:start position:0% +and time separately it's actually +minkowski's work not Einstein's at first + + align:start position:0% +minkowski's work not Einstein's at first + + + align:start position:0% +minkowski's work not Einstein's at first +then really introduces this notion of a + + align:start position:0% +then really introduces this notion of a + + + align:start position:0% +then really introduces this notion of a +union of space and time that very + + align:start position:0% +union of space and time that very + + + align:start position:0% +union of space and time that very +quickly becomes called by a single name + + align:start position:0% +quickly becomes called by a single name + + + align:start position:0% +quickly becomes called by a single name +space time so that's what minkowski is + + align:start position:0% +space time so that's what minkowski is + + + align:start position:0% +space time so that's what minkowski is +convinced is the only really important + + align:start position:0% +convinced is the only really important + + + align:start position:0% +convinced is the only really important +Insight or or outcome of Einstein's work + + align:start position:0% +Insight or or outcome of Einstein's work + + + align:start position:0% +Insight or or outcome of Einstein's work +it is geometrical so as he famously + + align:start position:0% +it is geometrical so as he famously + + + align:start position:0% +it is geometrical so as he famously +concludes in this article it was + + align:start position:0% +concludes in this article it was + + + align:start position:0% +concludes in this article it was +published soon after he passed away + + align:start position:0% +published soon after he passed away + + + align:start position:0% +published soon after he passed away +laying out all this work on space-time + + align:start position:0% +laying out all this work on space-time + + + align:start position:0% +laying out all this work on space-time +diagrams the invariant space-time + + align:start position:0% +diagrams the invariant space-time + + + align:start position:0% +diagrams the invariant space-time +interval and so on he says henceforth + + align:start position:0% +interval and so on he says henceforth + + + align:start position:0% +interval and so on he says henceforth +Space by itself and Time by itself are + + align:start position:0% +Space by itself and Time by itself are + + + align:start position:0% +Space by itself and Time by itself are +doomed to fade away into mere Shadows + + align:start position:0% +doomed to fade away into mere Shadows + + + align:start position:0% +doomed to fade away into mere Shadows +these are really just the projections on + + align:start position:0% +these are really just the projections on + + + align:start position:0% +these are really just the projections on +a on a idiosyncratic choice of + + align:start position:0% +a on a idiosyncratic choice of + + + align:start position:0% +a on a idiosyncratic choice of +coordinate axes these are mere shadows + + align:start position:0% +coordinate axes these are mere shadows + + + align:start position:0% +coordinate axes these are mere shadows +and only a kind of Union of the two a + + align:start position:0% +and only a kind of Union of the two a + + + align:start position:0% +and only a kind of Union of the two a +single Union of space-time will preserve + + align:start position:0% +single Union of space-time will preserve + + + align:start position:0% +single Union of space-time will preserve +Independence + + align:start position:0% +Independence + + + align:start position:0% +Independence +so let me pause there again and ask for + + align:start position:0% +so let me pause there again and ask for + + + align:start position:0% +so let me pause there again and ask for +any questions + + align:start position:0% +any questions + + + align:start position:0% +any questions +any questions on the minkowski stuff on + + align:start position:0% +any questions on the minkowski stuff on + + + align:start position:0% +any questions on the minkowski stuff on +where he was coming from + + align:start position:0% + + + + align:start position:0% + +so uh so Sulu asks what rhinestones are + + align:start position:0% +so uh so Sulu asks what rhinestones are + + + align:start position:0% +so uh so Sulu asks what rhinestones are +this reaction to mikowski good very good + + align:start position:0% +this reaction to mikowski good very good + + + align:start position:0% +this reaction to mikowski good very good +so the first reaction of Einstein to + + align:start position:0% +so the first reaction of Einstein to + + + align:start position:0% +so the first reaction of Einstein to +minkowski was also thoroughly + + align:start position:0% +minkowski was also thoroughly + + + align:start position:0% +minkowski was also thoroughly +predictable he hated it he never liked + + align:start position:0% +predictable he hated it he never liked + + + align:start position:0% +predictable he hated it he never liked +Mankowski as a person he cut his classes + + align:start position:0% +Mankowski as a person he cut his classes + + + align:start position:0% +Mankowski as a person he cut his classes +he was like oh look this guy still + + align:start position:0% +he was like oh look this guy still + + + align:start position:0% +he was like oh look this guy still +understands nothing important the + + align:start position:0% +understands nothing important the + + + align:start position:0% +understands nothing important the +feeling was totally + + align:start position:0% +feeling was totally + + + align:start position:0% +feeling was totally +um you know Mutual so minkowski thought + + align:start position:0% +um you know Mutual so minkowski thought + + + align:start position:0% +um you know Mutual so minkowski thought +Einstein had made a mess of things and + + align:start position:0% +Einstein had made a mess of things and + + + align:start position:0% +Einstein had made a mess of things and +only grudgingly paid attention Einstein + + align:start position:0% +only grudgingly paid attention Einstein + + + align:start position:0% +only grudgingly paid attention Einstein +read this paper said oh this guy + + align:start position:0% +read this paper said oh this guy + + + align:start position:0% +read this paper said oh this guy +understands nothing he's not reading + + align:start position:0% +understands nothing he's not reading + + + align:start position:0% +understands nothing he's not reading +Mark he missed the real conceptual + + align:start position:0% +Mark he missed the real conceptual + + + align:start position:0% +Mark he missed the real conceptual +Innovation he's just playing with axes + + align:start position:0% +Innovation he's just playing with axes + + + align:start position:0% +Innovation he's just playing with axes +now the difference was minkowski died + + align:start position:0% +now the difference was minkowski died + + + align:start position:0% +now the difference was minkowski died +and Einstein didn't in 1908 so Einstein + + align:start position:0% +and Einstein didn't in 1908 so Einstein + + + align:start position:0% +and Einstein didn't in 1908 so Einstein +later over and if I go look at this in + + align:start position:0% +later over and if I go look at this in + + + align:start position:0% +later over and if I go look at this in +our upcoming class session + + align:start position:0% +our upcoming class session + + + align:start position:0% +our upcoming class session +over the next several years again about + + align:start position:0% +over the next several years again about + + + align:start position:0% +over the next several years again about +four years after minkowski's work was + + align:start position:0% +four years after minkowski's work was + + + align:start position:0% +four years after minkowski's work was +published did Einstein slowly grudgingly + + align:start position:0% +published did Einstein slowly grudgingly + + + align:start position:0% +published did Einstein slowly grudgingly +with other kind of inputs and nudges + + align:start position:0% +with other kind of inputs and nudges + + + align:start position:0% +with other kind of inputs and nudges +begin to appreciate the geometrical view + + align:start position:0% +begin to appreciate the geometrical view + + + align:start position:0% +begin to appreciate the geometrical view +that minkowski was putting forward + + align:start position:0% +that minkowski was putting forward + + + align:start position:0% +that minkowski was putting forward +Einstein's original reaction was this + + align:start position:0% +Einstein's original reaction was this + + + align:start position:0% +Einstein's original reaction was this +guy still doesn't get it I would cut his + + align:start position:0% +guy still doesn't get it I would cut his + + + align:start position:0% +guy still doesn't get it I would cut his +classes again if I were still there I + + align:start position:0% +classes again if I were still there I + + + align:start position:0% +classes again if I were still there I +mean really was just less Mutual like + + align:start position:0% +mean really was just less Mutual like + + + align:start position:0% +mean really was just less Mutual like +and it's really about four years later + + align:start position:0% +and it's really about four years later + + + align:start position:0% +and it's really about four years later +as we'll talk a bit about uh in the next + + align:start position:0% +as we'll talk a bit about uh in the next + + + align:start position:0% +as we'll talk a bit about uh in the next +class that Einstein kind of grudgingly + + align:start position:0% +class that Einstein kind of grudgingly + + + align:start position:0% +class that Einstein kind of grudgingly +comes along to say geometry is really + + align:start position:0% +comes along to say geometry is really + + + align:start position:0% +comes along to say geometry is really +cool space time as a unified notion + + align:start position:0% +cool space time as a unified notion + + + align:start position:0% +cool space time as a unified notion +actually seems important and then he + + align:start position:0% +actually seems important and then he + + + align:start position:0% +actually seems important and then he +says oh I wish I had cited all that math + + align:start position:0% +says oh I wish I had cited all that math + + + align:start position:0% +says oh I wish I had cited all that math +after all and it goes back to one of his + + align:start position:0% +after all and it goes back to one of his + + + align:start position:0% +after all and it goes back to one of his +friends Marcel Grossman says oh not only + + align:start position:0% +friends Marcel Grossman says oh not only + + + align:start position:0% +friends Marcel Grossman says oh not only +can I borrow your notes can you teach me + + align:start position:0% +can I borrow your notes can you teach me + + + align:start position:0% +can I borrow your notes can you teach me +all the stuff I should have learned when + + align:start position:0% +all the stuff I should have learned when + + + align:start position:0% +all the stuff I should have learned when +I was in college lesson number three if + + align:start position:0% +I was in college lesson number three if + + + align:start position:0% +I was in college lesson number three if +don't act like Einstein + + align:start position:0% +don't act like Einstein + + + align:start position:0% +don't act like Einstein +so Gary asks if minkowski had lived who + + align:start position:0% +so Gary asks if minkowski had lived who + + + align:start position:0% +so Gary asks if minkowski had lived who +would have been deem the greater genius + + align:start position:0% +would have been deem the greater genius + + + align:start position:0% +would have been deem the greater genius +well that's that's an interesting + + align:start position:0% +well that's that's an interesting + + + align:start position:0% +well that's that's an interesting +question I don't know uh we could that's + + align:start position:0% +question I don't know uh we could that's + + + align:start position:0% +question I don't know uh we could that's +a Time varying question in 1909 still + + align:start position:0% +a Time varying question in 1909 still + + + align:start position:0% +a Time varying question in 1909 still +minkowski in 1915 I'm not sure in 1945 I + + align:start position:0% +minkowski in 1915 I'm not sure in 1945 I + + + align:start position:0% +minkowski in 1915 I'm not sure in 1945 I +don't know right it's interesting to see + + align:start position:0% +don't know right it's interesting to see + + + align:start position:0% +don't know right it's interesting to see +and I imagine the mathematicians then is + + align:start position:0% +and I imagine the mathematicians then is + + + align:start position:0% +and I imagine the mathematicians then is +now would Harold minkowski's work for a + + align:start position:0% +now would Harold minkowski's work for a + + + align:start position:0% +now would Harold minkowski's work for a +lot longer we'd see I'm sure some + + align:start position:0% +lot longer we'd see I'm sure some + + + align:start position:0% +lot longer we'd see I'm sure some +different opinions continue to vary + + align:start position:0% +different opinions continue to vary + + + align:start position:0% +different opinions continue to vary +uh Jesus writes it's scary to realize + + align:start position:0% +uh Jesus writes it's scary to realize + + + align:start position:0% +uh Jesus writes it's scary to realize +that nobody cared too much about these + + align:start position:0% +that nobody cared too much about these + + + align:start position:0% +that nobody cared too much about these +Grand breaking results for so long makes + + align:start position:0% +Grand breaking results for so long makes + + + align:start position:0% +Grand breaking results for so long makes +me wonder what kind of groundbreaking + + align:start position:0% +me wonder what kind of groundbreaking + + + align:start position:0% +me wonder what kind of groundbreaking +work may have actually fallen through + + align:start position:0% +work may have actually fallen through + + + align:start position:0% +work may have actually fallen through +the cracks and never gotten a full + + align:start position:0% +the cracks and never gotten a full + + + align:start position:0% +the cracks and never gotten a full +exploration but yes that's a fair point + + align:start position:0% +exploration but yes that's a fair point + + + align:start position:0% +exploration but yes that's a fair point +uh you know that's something we can keep + + align:start position:0% +uh you know that's something we can keep + + + align:start position:0% +uh you know that's something we can keep +in mind throughout this whole semester + + align:start position:0% +in mind throughout this whole semester + + + align:start position:0% +in mind throughout this whole semester +um not only uh + + align:start position:0% +um not only uh + + + align:start position:0% +um not only uh +you know there's all kinds of + + align:start position:0% +you know there's all kinds of + + + align:start position:0% +you know there's all kinds of +gatekeeping about who determines at what + + align:start position:0% +gatekeeping about who determines at what + + + align:start position:0% +gatekeeping about who determines at what +time what what work is worth paying + + align:start position:0% +time what what work is worth paying + + + align:start position:0% +time what what work is worth paying +attention to + + align:start position:0% +attention to + + + align:start position:0% +attention to +institutions play a role individual + + align:start position:0% +institutions play a role individual + + + align:start position:0% +institutions play a role individual +rivalries play a role soon we'll come to + + align:start position:0% +rivalries play a role soon we'll come to + + + align:start position:0% +rivalries play a role soon we'll come to +examples where worldly events play a + + align:start position:0% +examples where worldly events play a + + + align:start position:0% +examples where worldly events play a +role well beyond the control of Any + + align:start position:0% +role well beyond the control of Any + + + align:start position:0% +role well beyond the control of Any +Given individual or institution uh + + align:start position:0% +Given individual or institution uh + + + align:start position:0% +Given individual or institution uh +sexism plays a role racism plays a role + + align:start position:0% +sexism plays a role racism plays a role + + + align:start position:0% +sexism plays a role racism plays a role +I mean there's all kinds of things that + + align:start position:0% +I mean there's all kinds of things that + + + align:start position:0% +I mean there's all kinds of things that +factor into who who determines this is + + align:start position:0% +factor into who who determines this is + + + align:start position:0% +factor into who who determines this is +of value and worth paying attention to + + align:start position:0% +of value and worth paying attention to + + + align:start position:0% +of value and worth paying attention to +at any given time and that's a kind of + + align:start position:0% +at any given time and that's a kind of + + + align:start position:0% +at any given time and that's a kind of +General historical lesson we grapple + + align:start position:0% +General historical lesson we grapple + + + align:start position:0% +General historical lesson we grapple +with you all the time not just in the + + align:start position:0% +with you all the time not just in the + + + align:start position:0% +with you all the time not just in the +history of science but but much more + + align:start position:0% +history of science but but much more + + + align:start position:0% +history of science but but much more +generally and we'll have a lot of + + align:start position:0% +generally and we'll have a lot of + + + align:start position:0% +generally and we'll have a lot of +examples of that really actually more + + align:start position:0% +examples of that really actually more + + + align:start position:0% +examples of that really actually more +examples even pretty soon in in our own + + align:start position:0% +examples even pretty soon in in our own + + + align:start position:0% +examples even pretty soon in in our own +class The Zone examples we might think + + align:start position:0% +class The Zone examples we might think + + + align:start position:0% +class The Zone examples we might think +of from from other uh instances + + align:start position:0% +of from from other uh instances + + + align:start position:0% +of from from other uh instances +uh here's an example where to to his + + align:start position:0% +uh here's an example where to to his + + + align:start position:0% +uh here's an example where to to his +credit Einstein later grudgingly came + + align:start position:0% +credit Einstein later grudgingly came + + + align:start position:0% +credit Einstein later grudgingly came +around to say oh that stuff is important + + align:start position:0% +around to say oh that stuff is important + + + align:start position:0% +around to say oh that stuff is important +minkowski does deserve credit I now see + + align:start position:0% +minkowski does deserve credit I now see + + + align:start position:0% +minkowski does deserve credit I now see +it was really valuable but it took Eisen + + align:start position:0% +it was really valuable but it took Eisen + + + align:start position:0% +it was really valuable but it took Eisen +himself quite a few years to get there + + align:start position:0% +himself quite a few years to get there + + + align:start position:0% +himself quite a few years to get there +doesn't always happen uh or there can be + + align:start position:0% +doesn't always happen uh or there can be + + + align:start position:0% +doesn't always happen uh or there can be +a much longer delay + + align:start position:0% +a much longer delay + + + align:start position:0% +a much longer delay +any other questions on on minkowski's + + align:start position:0% +any other questions on on minkowski's + + + align:start position:0% +any other questions on on minkowski's +um kind of reaction to or remaking of of + + align:start position:0% +um kind of reaction to or remaking of of + + + align:start position:0% +um kind of reaction to or remaking of of +Einstein's work + + align:start position:0% + + + + align:start position:0% + +so minkowski actually thought this was + + align:start position:0% +so minkowski actually thought this was + + + align:start position:0% +so minkowski actually thought this was +really a big deal minkowsey thought his + + align:start position:0% +really a big deal minkowsey thought his + + + align:start position:0% +really a big deal minkowsey thought his +own work was a big deal which is not + + align:start position:0% +own work was a big deal which is not + + + align:start position:0% +own work was a big deal which is not +shocking it's also not unique in the + + align:start position:0% +shocking it's also not unique in the + + + align:start position:0% +shocking it's also not unique in the +history science and in particular he + + align:start position:0% +history science and in particular he + + + align:start position:0% +history science and in particular he +thought it wasn't actually only about + + align:start position:0% +thought it wasn't actually only about + + + align:start position:0% +thought it wasn't actually only about +coordinate Transformations rotations of + + align:start position:0% +coordinate Transformations rotations of + + + align:start position:0% +coordinate Transformations rotations of +axes he thought that was the most + + align:start position:0% +axes he thought that was the most + + + align:start position:0% +axes he thought that was the most +obvious thing to do and anyone who + + align:start position:0% +obvious thing to do and anyone who + + + align:start position:0% +obvious thing to do and anyone who +doesn't do that is a dummy right he had + + align:start position:0% +doesn't do that is a dummy right he had + + + align:start position:0% +doesn't do that is a dummy right he had +very clear ideas about the proper tools + + align:start position:0% +very clear ideas about the proper tools + + + align:start position:0% +very clear ideas about the proper tools +of research but even in that first + + align:start position:0% +of research but even in that first + + + align:start position:0% +of research but even in that first +article that gets published soon after + + align:start position:0% +article that gets published soon after + + + align:start position:0% +article that gets published soon after +he passed away he develops in the later + + align:start position:0% +he passed away he develops in the later + + + align:start position:0% +he passed away he develops in the later +sections a larger kind of world view + + align:start position:0% +sections a larger kind of world view + + + align:start position:0% +sections a larger kind of world view +literally a view of the world that's + + align:start position:0% +literally a view of the world that's + + + align:start position:0% +literally a view of the world that's +based on this Union space-time notion it + + align:start position:0% +based on this Union space-time notion it + + + align:start position:0% +based on this Union space-time notion it +gets very wrapped up with certain Trends + + align:start position:0% +gets very wrapped up with certain Trends + + + align:start position:0% +gets very wrapped up with certain Trends +in in idealist German philosophy he's + + align:start position:0% +in in idealist German philosophy he's + + + align:start position:0% +in in idealist German philosophy he's +very inspired by the work of Emmanuel + + align:start position:0% +very inspired by the work of Emmanuel + + + align:start position:0% +very inspired by the work of Emmanuel +Kant for example + + align:start position:0% +Kant for example + + + align:start position:0% +Kant for example +as I was too but in different ways and + + align:start position:0% +as I was too but in different ways and + + + align:start position:0% +as I was too but in different ways and +so as far as Mankowski is concerned he + + align:start position:0% +so as far as Mankowski is concerned he + + + align:start position:0% +so as far as Mankowski is concerned he +thought he found like a new deep level + + align:start position:0% +thought he found like a new deep level + + + align:start position:0% +thought he found like a new deep level +of reality the reality wasn't The Ether + + align:start position:0% +of reality the reality wasn't The Ether + + + align:start position:0% +of reality the reality wasn't The Ether +it was aptitude minkowski the reality + + align:start position:0% +it was aptitude minkowski the reality + + + align:start position:0% +it was aptitude minkowski the reality +was there's this single thing space time + + align:start position:0% +was there's this single thing space time + + + align:start position:0% +was there's this single thing space time +and there are certain things on which + + align:start position:0% +and there are certain things on which + + + align:start position:0% +and there are certain things on which +all people will agree these invariances + + align:start position:0% +all people will agree these invariances + + + align:start position:0% +all people will agree these invariances +even as we disagree separately on on + + align:start position:0% +even as we disagree separately on on + + + align:start position:0% +even as we disagree separately on on +measurements of length and measurements + + align:start position:0% +measurements of length and measurements + + + align:start position:0% +measurements of length and measurements +of time + + align:start position:0% +of time + + + align:start position:0% +of time +and so that for him and reintroduce a + + align:start position:0% +and so that for him and reintroduce a + + + align:start position:0% +and so that for him and reintroduce a +kind of absolute an absolutism not + + align:start position:0% +kind of absolute an absolutism not + + + align:start position:0% +kind of absolute an absolutism not +absolute rest like in Newton not + + align:start position:0% +absolute rest like in Newton not + + + align:start position:0% +absolute rest like in Newton not +absolute space because space and time he + + align:start position:0% +absolute space because space and time he + + + align:start position:0% +absolute space because space and time he +says are now just mere Shadows but there + + align:start position:0% +says are now just mere Shadows but there + + + align:start position:0% +says are now just mere Shadows but there +is an absolute um past and an absolute + + align:start position:0% +is an absolute um past and an absolute + + + align:start position:0% +is an absolute um past and an absolute +future there's an absolute away the + + align:start position:0% +future there's an absolute away the + + + align:start position:0% +future there's an absolute away the +things that we would now call if you've + + align:start position:0% +things that we would now call if you've + + + align:start position:0% +things that we would now call if you've +had some more coursework in this area + + align:start position:0% +had some more coursework in this area + + + align:start position:0% +had some more coursework in this area +you'd recognize as things like um space + + align:start position:0% +you'd recognize as things like um space + + + align:start position:0% +you'd recognize as things like um space +like separated and so on he starts + + align:start position:0% +like separated and so on he starts + + + align:start position:0% +like separated and so on he starts +mapping sets of events that could not + + align:start position:0% +mapping sets of events that could not + + + align:start position:0% +mapping sets of events that could not +possibly have exchanged even a single + + align:start position:0% +possibly have exchanged even a single + + + align:start position:0% +possibly have exchanged even a single +light signal yet those are absolutely + + align:start position:0% +light signal yet those are absolutely + + + align:start position:0% +light signal yet those are absolutely +separated from each other and he gives + + align:start position:0% +separated from each other and he gives + + + align:start position:0% +separated from each other and he gives +these very absolutist language to them + + align:start position:0% +these very absolutist language to them + + + align:start position:0% +these very absolutist language to them +so he's actually mapping what he + + align:start position:0% +so he's actually mapping what he + + + align:start position:0% +so he's actually mapping what he +considers like the ultimate absolute + + align:start position:0% +considers like the ultimate absolute + + + align:start position:0% +considers like the ultimate absolute +structure of space-time and as far as + + align:start position:0% +structure of space-time and as far as + + + align:start position:0% +structure of space-time and as far as +he's concerned that's the real lesson + + align:start position:0% +he's concerned that's the real lesson + + + align:start position:0% +he's concerned that's the real lesson +that the geometry leads us to so he + + align:start position:0% +that the geometry leads us to so he + + + align:start position:0% +that the geometry leads us to so he +actually thinks it's not a theory of + + align:start position:0% +actually thinks it's not a theory of + + + align:start position:0% +actually thinks it's not a theory of +relativity at all relativity is like an + + align:start position:0% +relativity at all relativity is like an + + + align:start position:0% +relativity at all relativity is like an +accident and boring and trivial and the + + align:start position:0% +accident and boring and trivial and the + + + align:start position:0% +accident and boring and trivial and the +stupid thing that no one should pay + + align:start position:0% +stupid thing that no one should pay + + + align:start position:0% +stupid thing that no one should pay +attention to right relativity all we + + align:start position:0% +attention to right relativity all we + + + align:start position:0% +attention to right relativity all we +differ the person that trains says this + + align:start position:0% +differ the person that trains says this + + + align:start position:0% +differ the person that trains says this +wasn't the same says that's just + + align:start position:0% +wasn't the same says that's just + + + align:start position:0% +wasn't the same says that's just +accidents who cares what's actually + + align:start position:0% +accidents who cares what's actually + + + align:start position:0% +accidents who cares what's actually +important are these underlying + + align:start position:0% +important are these underlying + + + align:start position:0% +important are these underlying +invariances or absolutes we all agree on + + align:start position:0% +invariances or absolutes we all agree on + + + align:start position:0% +invariances or absolutes we all agree on +certain combinations of things and + + align:start position:0% +certain combinations of things and + + + align:start position:0% +certain combinations of things and +that's the real lesson so for him this + + align:start position:0% +that's the real lesson so for him this + + + align:start position:0% +that's the real lesson so for him this +becomes + + align:start position:0% +becomes + + + align:start position:0% +becomes +a kind of re-injection of the absolute + + align:start position:0% +a kind of re-injection of the absolute + + + align:start position:0% +a kind of re-injection of the absolute +not because we're all sitting in a + + align:start position:0% +not because we're all sitting in a + + + align:start position:0% +not because we're all sitting in a +physical ether he couldn't care less + + align:start position:0% +physical ether he couldn't care less + + + align:start position:0% +physical ether he couldn't care less +he's a geometer because there is a kind + + align:start position:0% +he's a geometer because there is a kind + + + align:start position:0% +he's a geometer because there is a kind +of a unique structure to space-time that + + align:start position:0% +of a unique structure to space-time that + + + align:start position:0% +of a unique structure to space-time that +the tools of geometry are uniquely well + + align:start position:0% +the tools of geometry are uniquely well + + + align:start position:0% +the tools of geometry are uniquely well +um well adapted to help us understand so + + align:start position:0% +um well adapted to help us understand so + + + align:start position:0% +um well adapted to help us understand so +that that + + align:start position:0% +that that + + + align:start position:0% +that that +makes sense does it make address your + + align:start position:0% +makes sense does it make address your + + + align:start position:0% +makes sense does it make address your +question okay cool thank you so let's + + align:start position:0% +question okay cool thank you so let's + + + align:start position:0% +question okay cool thank you so let's +see Fisher asks the question to chat we + + align:start position:0% +see Fisher asks the question to chat we + + + align:start position:0% +see Fisher asks the question to chat we +now think of space-time as something as + + align:start position:0% +now think of space-time as something as + + + align:start position:0% +now think of space-time as something as +deformable hey that's cheating who + + align:start position:0% +deformable hey that's cheating who + + + align:start position:0% +deformable hey that's cheating who +that's we're going to get there next + + align:start position:0% +that's we're going to get there next + + + align:start position:0% +that's we're going to get there next +week you don't know that yet it's 1905 + + align:start position:0% +week you don't know that yet it's 1905 + + + align:start position:0% +week you don't know that yet it's 1905 +it's 1908. but you're right certainly as + + align:start position:0% +it's 1908. but you're right certainly as + + + align:start position:0% +it's 1908. but you're right certainly as +we'll talk about quite a lot uh starting + + align:start position:0% +we'll talk about quite a lot uh starting + + + align:start position:0% +we'll talk about quite a lot uh starting +uh in this coming the next class session + + align:start position:0% +uh in this coming the next class session + + + align:start position:0% +uh in this coming the next class session +where eyesight himself gets to is to + + align:start position:0% +where eyesight himself gets to is to + + + align:start position:0% +where eyesight himself gets to is to +begin thinking about space-time as one + + align:start position:0% +begin thinking about space-time as one + + + align:start position:0% +begin thinking about space-time as one +thing that also can respond to be + + align:start position:0% +thing that also can respond to be + + + align:start position:0% +thing that also can respond to be +deformable + + align:start position:0% +deformable + + + align:start position:0% +deformable +Andrew originally introduced as a + + align:start position:0% +Andrew originally introduced as a + + + align:start position:0% +Andrew originally introduced as a +mathematical artifact was a point where + + align:start position:0% +mathematical artifact was a point where + + + align:start position:0% +mathematical artifact was a point where +we moved from thinking about it as a + + align:start position:0% +we moved from thinking about it as a + + + align:start position:0% +we moved from thinking about it as a +mathematical concept what generally was + + align:start position:0% +mathematical concept what generally was + + + align:start position:0% +mathematical concept what generally was +published yes very good okay so fishery + + align:start position:0% +published yes very good okay so fishery + + + align:start position:0% +published yes very good okay so fishery +um it's a great question thank you for + + align:start position:0% +um it's a great question thank you for + + + align:start position:0% +um it's a great question thank you for +that and we're going to come we're going + + align:start position:0% +that and we're going to come we're going + + + align:start position:0% +that and we're going to come we're going +to sit with that actually quite directly + + align:start position:0% +to sit with that actually quite directly + + + align:start position:0% +to sit with that actually quite directly +on our next class so I'm going to punt + + align:start position:0% +on our next class so I'm going to punt + + + align:start position:0% +on our next class so I'm going to punt +on that for now the short answer is if + + align:start position:0% +on that for now the short answer is if + + + align:start position:0% +on that for now the short answer is if +it's not it doesn't come only when + + align:start position:0% +it's not it doesn't come only when + + + align:start position:0% +it's not it doesn't come only when +Einstein publishes gender relativity + + align:start position:0% +Einstein publishes gender relativity + + + align:start position:0% +Einstein publishes gender relativity +that comes a very late 1915 but it's an + + align:start position:0% +that comes a very late 1915 but it's an + + + align:start position:0% +that comes a very late 1915 but it's an +evolution in Einstein's own thinking + + align:start position:0% +evolution in Einstein's own thinking + + + align:start position:0% +evolution in Einstein's own thinking +with some colleagues like Marcel + + align:start position:0% +with some colleagues like Marcel + + + align:start position:0% +with some colleagues like Marcel +Grossman in a small circle over the over + + align:start position:0% +Grossman in a small circle over the over + + + align:start position:0% +Grossman in a small circle over the over +the intermediate decade so starting + + align:start position:0% +the intermediate decade so starting + + + align:start position:0% +the intermediate decade so starting +around 19 11 12 13 he has a lot of + + align:start position:0% +around 19 11 12 13 he has a lot of + + + align:start position:0% +around 19 11 12 13 he has a lot of +mistakes a lot of blind alleys he starts + + align:start position:0% +mistakes a lot of blind alleys he starts + + + align:start position:0% +mistakes a lot of blind alleys he starts +wondering about that more in the terms + + align:start position:0% +wondering about that more in the terms + + + align:start position:0% +wondering about that more in the terms +as you describe it + + align:start position:0% +as you describe it + + + align:start position:0% +as you describe it +um starting + + align:start position:0% +um starting + + + align:start position:0% +um starting +well Downstream both from his own work + + align:start position:0% +well Downstream both from his own work + + + align:start position:0% +well Downstream both from his own work +in 1905 Downstream by four years even + + align:start position:0% +in 1905 Downstream by four years even + + + align:start position:0% +in 1905 Downstream by four years even +from minkowski's work it's a real kind + + align:start position:0% +from minkowski's work it's a real kind + + + align:start position:0% +from minkowski's work it's a real kind +of intellectual Journey so that's that's + + align:start position:0% +of intellectual Journey so that's that's + + + align:start position:0% +of intellectual Journey so that's that's +a preview we'll get there next time + + align:start position:0% +a preview we'll get there next time + + + align:start position:0% +a preview we'll get there next time +great Gary asks how did folks react to + + align:start position:0% +great Gary asks how did folks react to + + + align:start position:0% +great Gary asks how did folks react to +mikowski's work again I think maybe + + align:start position:0% +mikowski's work again I think maybe + + + align:start position:0% +mikowski's work again I think maybe +sorry maybe I mentioned that or you had + + align:start position:0% +sorry maybe I mentioned that or you had + + + align:start position:0% +sorry maybe I mentioned that or you had +asked earlier who was it who made the + + align:start position:0% +asked earlier who was it who made the + + + align:start position:0% +asked earlier who was it who made the +greater contribution yominkowski was on + + align:start position:0% +greater contribution yominkowski was on + + + align:start position:0% +greater contribution yominkowski was on +people's radar screen he was a big fancy + + align:start position:0% +people's radar screen he was a big fancy + + + align:start position:0% +people's radar screen he was a big fancy +senior mathematician very widely + + align:start position:0% +senior mathematician very widely + + + align:start position:0% +senior mathematician very widely +published very influential at a central + + align:start position:0% +published very influential at a central + + + align:start position:0% +published very influential at a central +you know center of learning in Western + + align:start position:0% +you know center of learning in Western + + + align:start position:0% +you know center of learning in Western +Europe so his work was paid attention to + + align:start position:0% +Europe so his work was paid attention to + + + align:start position:0% +Europe so his work was paid attention to +mostly by other mathematicians and by + + align:start position:0% +mostly by other mathematicians and by + + + align:start position:0% +mostly by other mathematicians and by +some sort of mathematical physicists uh + + align:start position:0% +some sort of mathematical physicists uh + + + align:start position:0% +some sort of mathematical physicists uh +like uh Hedrick Lorenz + + align:start position:0% +like uh Hedrick Lorenz + + + align:start position:0% +like uh Hedrick Lorenz +uh not every single physicist it's not + + align:start position:0% +uh not every single physicist it's not + + + align:start position:0% +uh not every single physicist it's not +every experimental physicist but it was + + align:start position:0% +every experimental physicist but it was + + + align:start position:0% +every experimental physicist but it was +not kind of buried and forgotten for + + align:start position:0% +not kind of buried and forgotten for + + + align:start position:0% +not kind of buried and forgotten for +years and years it was appreciated in + + align:start position:0% +years and years it was appreciated in + + + align:start position:0% +years and years it was appreciated in +certain specialist communities right + + align:start position:0% +certain specialist communities right + + + align:start position:0% +certain specialist communities right +away and then as we'll talk about uh + + align:start position:0% +away and then as we'll talk about uh + + + align:start position:0% +away and then as we'll talk about uh +later even other people like Einstein + + align:start position:0% +later even other people like Einstein + + + align:start position:0% +later even other people like Einstein +belatedly come to admire it as well so + + align:start position:0% +belatedly come to admire it as well so + + + align:start position:0% +belatedly come to admire it as well so +it becomes very very well known partly I + + align:start position:0% +it becomes very very well known partly I + + + align:start position:0% +it becomes very very well known partly I +think because Einstein goes back to it + + align:start position:0% +think because Einstein goes back to it + + + align:start position:0% +think because Einstein goes back to it +and Eisen herself becomes then + + align:start position:0% +and Eisen herself becomes then + + + align:start position:0% +and Eisen herself becomes then +eventually someone that everyone pays + + align:start position:0% +eventually someone that everyone pays + + + align:start position:0% +eventually someone that everyone pays +attention to many people so it has a + + align:start position:0% +attention to many people so it has a + + + align:start position:0% +attention to many people so it has a +kind of bumpy few years but it was not + + align:start position:0% +kind of bumpy few years but it was not + + + align:start position:0% +kind of bumpy few years but it was not +launched Into Obscurity because + + align:start position:0% +launched Into Obscurity because + + + align:start position:0% +launched Into Obscurity because +minkowski himself was actually already + + align:start position:0% +minkowski himself was actually already + + + align:start position:0% +minkowski himself was actually already +quite well established and well known + + align:start position:0% +quite well established and well known + + + align:start position:0% +quite well established and well known +asks what was Lorenzo's stats with + + align:start position:0% +asks what was Lorenzo's stats with + + + align:start position:0% +asks what was Lorenzo's stats with +regard to this good did he jump on the + + align:start position:0% +regard to this good did he jump on the + + + align:start position:0% +regard to this good did he jump on the +space-time wagon great so the short + + align:start position:0% +space-time wagon great so the short + + + align:start position:0% +space-time wagon great so the short +answer is we'll see an example of the + + align:start position:0% +answer is we'll see an example of the + + + align:start position:0% +answer is we'll see an example of the +kind of reaction action the next part of + + align:start position:0% +kind of reaction action the next part of + + + align:start position:0% +kind of reaction action the next part of +today's class not Lorenz per se but an + + align:start position:0% +today's class not Lorenz per se but an + + + align:start position:0% +today's class not Lorenz per se but an +example + + align:start position:0% +example + + + align:start position:0% +example +Lorenz really for for the rest of his + + align:start position:0% +Lorenz really for for the rest of his + + + align:start position:0% +Lorenz really for for the rest of his +career was still pretty convinced The + + align:start position:0% +career was still pretty convinced The + + + align:start position:0% +career was still pretty convinced The +Ether exists and he had a great + + align:start position:0% +Ether exists and he had a great + + + align:start position:0% +Ether exists and he had a great +appreciation for some of these very + + align:start position:0% +appreciation for some of these very + + + align:start position:0% +appreciation for some of these very +clever mathematical techniques he + + align:start position:0% +clever mathematical techniques he + + + align:start position:0% +clever mathematical techniques he +certainly liked it that Einsteins and + + align:start position:0% +certainly liked it that Einsteins and + + + align:start position:0% +certainly liked it that Einsteins and +now minkowski's work LED back to + + align:start position:0% +now minkowski's work LED back to + + + align:start position:0% +now minkowski's work LED back to +equations that he himself had derived + + align:start position:0% +equations that he himself had derived + + + align:start position:0% +equations that he himself had derived +from his own + + align:start position:0% +from his own + + + align:start position:0% +from his own +set of of arguments but he really was + + align:start position:0% +set of of arguments but he really was + + + align:start position:0% +set of of arguments but he really was +convinced that you know there's + + align:start position:0% +convinced that you know there's + + + align:start position:0% +convinced that you know there's +something physical about this elastic + + align:start position:0% +something physical about this elastic + + + align:start position:0% +something physical about this elastic +medium in which we're all immersed for a + + align:start position:0% +medium in which we're all immersed for a + + + align:start position:0% +medium in which we're all immersed for a +long long time so he thought these were + + align:start position:0% +long long time so he thought these were + + + align:start position:0% +long long time so he thought these were +more Cool Tools more mathematical tools + + align:start position:0% +more Cool Tools more mathematical tools + + + align:start position:0% +more Cool Tools more mathematical tools +with which to keep asking questions you + + align:start position:0% +with which to keep asking questions you + + + align:start position:0% +with which to keep asking questions you +already considered important those + + align:start position:0% +already considered important those + + + align:start position:0% +already considered important those +warrant as we've seen the same set of + + align:start position:0% +warrant as we've seen the same set of + + + align:start position:0% +warrant as we've seen the same set of +questions that Einstein thought were + + align:start position:0% +questions that Einstein thought were + + + align:start position:0% +questions that Einstein thought were +important or the minkowski file report + + align:start position:0% +important or the minkowski file report + + + align:start position:0% +important or the minkowski file report +and in that sense it's a lot like the + + align:start position:0% +and in that sense it's a lot like the + + + align:start position:0% +and in that sense it's a lot like the +example we look at now from Cambridge + + align:start position:0% + + + + align:start position:0% + +yeah very good so again we'll look at + + align:start position:0% +yeah very good so again we'll look at + + + align:start position:0% +yeah very good so again we'll look at +this much more directly in the upcoming + + align:start position:0% +this much more directly in the upcoming + + + align:start position:0% +this much more directly in the upcoming +class session next week the short answer + + align:start position:0% +class session next week the short answer + + + align:start position:0% +class session next week the short answer +was it wasn't really minkowski per se + + align:start position:0% +was it wasn't really minkowski per se + + + align:start position:0% +was it wasn't really minkowski per se +because he just had no respect for + + align:start position:0% +because he just had no respect for + + + align:start position:0% +because he just had no respect for +McAlister cutting his mask + + align:start position:0% +McAlister cutting his mask + + + align:start position:0% +McAlister cutting his mask +um it was actually an independent series + + align:start position:0% +um it was actually an independent series + + + align:start position:0% +um it was actually an independent series +of thought experiments and and + + align:start position:0% +of thought experiments and and + + + align:start position:0% +of thought experiments and and +conceptual puzzles and calculations that + + align:start position:0% +conceptual puzzles and calculations that + + + align:start position:0% +conceptual puzzles and calculations that +Einstein got immersed in and he kept + + align:start position:0% +Einstein got immersed in and he kept + + + align:start position:0% +Einstein got immersed in and he kept +getting stuck and he let that led him + + align:start position:0% +getting stuck and he let that led him + + + align:start position:0% +getting stuck and he let that led him +back to realizing geometry might be + + align:start position:0% +back to realizing geometry might be + + + align:start position:0% +back to realizing geometry might be +really important by which point + + align:start position:0% +really important by which point + + + align:start position:0% +really important by which point +minkowski had died he went to his former + + align:start position:0% +minkowski had died he went to his former + + + align:start position:0% +minkowski had died he went to his former +classmate his buddy um Marcel Grossman + + align:start position:0% +classmate his buddy um Marcel Grossman + + + align:start position:0% +classmate his buddy um Marcel Grossman +and had to do like a crash course on the + + align:start position:0% +and had to do like a crash course on the + + + align:start position:0% +and had to do like a crash course on the +stuff that he kind of should have + + align:start position:0% +stuff that he kind of should have + + + align:start position:0% +stuff that he kind of should have +learned uh when he was an undergraduate + + align:start position:0% +learned uh when he was an undergraduate + + + align:start position:0% +learned uh when he was an undergraduate +so it was he came to an appreciation of + + align:start position:0% +so it was he came to an appreciation of + + + align:start position:0% +so it was he came to an appreciation of +the geometrical approach of minkowski's + + align:start position:0% +the geometrical approach of minkowski's + + + align:start position:0% +the geometrical approach of minkowski's +work in particular thinking about a + + align:start position:0% +work in particular thinking about a + + + align:start position:0% +work in particular thinking about a +single object called space time he gets + + align:start position:0% +single object called space time he gets + + + align:start position:0% +single object called space time he gets +there but not because he reads + + align:start position:0% +there but not because he reads + + + align:start position:0% +there but not because he reads +minkowski's paper says oh my great + + align:start position:0% +minkowski's paper says oh my great + + + align:start position:0% +minkowski's paper says oh my great +Professor I'm totally convinced he's + + align:start position:0% +Professor I'm totally convinced he's + + + align:start position:0% +Professor I'm totally convinced he's +like that's dumb it's wrong it's boring + + align:start position:0% +like that's dumb it's wrong it's boring + + + align:start position:0% +like that's dumb it's wrong it's boring +he's still irrelevant I would cut his + + align:start position:0% +he's still irrelevant I would cut his + + + align:start position:0% +he's still irrelevant I would cut his +classes again if that's the reaction for + + align:start position:0% +classes again if that's the reaction for + + + align:start position:0% +classes again if that's the reaction for +like four years three or four years + + align:start position:0% +like four years three or four years + + + align:start position:0% +like four years three or four years +and it's a separate set of of + + align:start position:0% +and it's a separate set of of + + + align:start position:0% +and it's a separate set of of +um lines of thought that kind of and + + align:start position:0% +um lines of thought that kind of and + + + align:start position:0% +um lines of thought that kind of and +interactions with other people including + + align:start position:0% +interactions with other people including + + + align:start position:0% +interactions with other people including +friends who were more a better verse in + + align:start position:0% +friends who were more a better verse in + + + align:start position:0% +friends who were more a better verse in +mathematics that bring him his own + + align:start position:0% +mathematics that bring him his own + + + align:start position:0% +mathematics that bring him his own +thinking back uh or bring it presenting + + align:start position:0% +thinking back uh or bring it presenting + + + align:start position:0% +thinking back uh or bring it presenting +towards a more thoroughly geometrical + + align:start position:0% +towards a more thoroughly geometrical + + + align:start position:0% +towards a more thoroughly geometrical +approach and then he never leaves then + + align:start position:0% +approach and then he never leaves then + + + align:start position:0% +approach and then he never leaves then +he becomes a kind of card-carrying + + align:start position:0% +he becomes a kind of card-carrying + + + align:start position:0% +he becomes a kind of card-carrying +geometer himself once he gets a crash + + align:start position:0% +geometer himself once he gets a crash + + + align:start position:0% +geometer himself once he gets a crash +course from real geometers and gets a + + align:start position:0% +course from real geometers and gets a + + + align:start position:0% +course from real geometers and gets a +kind of Newfound appreciation because of + + align:start position:0% +kind of Newfound appreciation because of + + + align:start position:0% +kind of Newfound appreciation because of +his own questions have led him there so + + align:start position:0% +his own questions have led him there so + + + align:start position:0% +his own questions have led him there so +it's it's he he comes to greatly admire + + align:start position:0% +it's it's he he comes to greatly admire + + + align:start position:0% +it's it's he he comes to greatly admire +minkowski's work and indeed to try to + + align:start position:0% +minkowski's work and indeed to try to + + + align:start position:0% +minkowski's work and indeed to try to +build upon it as we'll see next time but + + align:start position:0% +build upon it as we'll see next time but + + + align:start position:0% +build upon it as we'll see next time but +not because he thought oh this is a cool + + align:start position:0% +not because he thought oh this is a cool + + + align:start position:0% +not because he thought oh this is a cool +work by smart person it was again a kind + + align:start position:0% +work by smart person it was again a kind + + + align:start position:0% +work by smart person it was again a kind +of roundabout thing + + align:start position:0% +of roundabout thing + + + align:start position:0% +of roundabout thing +um and so we'll look at that in a bit + + align:start position:0% +um and so we'll look at that in a bit + + + align:start position:0% +um and so we'll look at that in a bit +more detail in the coming class + + align:start position:0% +more detail in the coming class + + + align:start position:0% +more detail in the coming class +another question on this stuff if not + + align:start position:0% +another question on this stuff if not + + + align:start position:0% +another question on this stuff if not +I'll go to this last part of the lecture + + align:start position:0% +I'll go to this last part of the lecture + + + align:start position:0% +I'll go to this last part of the lecture +on some of the pretty wacky work that + + align:start position:0% +on some of the pretty wacky work that + + + align:start position:0% +on some of the pretty wacky work that +the Cambridge gang + + align:start position:0% +the Cambridge gang + + + align:start position:0% +the Cambridge gang +so I started with us as well + + align:start position:0% + + + + align:start position:0% + +yeah thank you Fisher so so as far as + + align:start position:0% +yeah thank you Fisher so so as far as + + + align:start position:0% +yeah thank you Fisher so so as far as +minkowski is concerned Einstein's paper + + align:start position:0% +minkowski is concerned Einstein's paper + + + align:start position:0% +minkowski is concerned Einstein's paper +especially the first few pages which you + + align:start position:0% +especially the first few pages which you + + + align:start position:0% +especially the first few pages which you +are all dutifully reviewing and maybe + + align:start position:0% +are all dutifully reviewing and maybe + + + align:start position:0% +are all dutifully reviewing and maybe +even rejecting + + align:start position:0% +even rejecting + + + align:start position:0% +even rejecting +um or not or ask me at least for + + align:start position:0% +um or not or ask me at least for + + + align:start position:0% +um or not or ask me at least for +revisions the first few pages at least + + align:start position:0% +revisions the first few pages at least + + + align:start position:0% +revisions the first few pages at least +are really to to someone like Ben Cassie + + align:start position:0% +are really to to someone like Ben Cassie + + + align:start position:0% +are really to to someone like Ben Cassie +a kind of jumble word salad this is like + + align:start position:0% +a kind of jumble word salad this is like + + + align:start position:0% +a kind of jumble word salad this is like +you know + + align:start position:0% +you know + + + align:start position:0% +you know +of course you know I know how to + + align:start position:0% +of course you know I know how to + + + align:start position:0% +of course you know I know how to +calculate distance traveled if the + + align:start position:0% +calculate distance traveled if the + + + align:start position:0% +calculate distance traveled if the +person's traveling at constant speed + + align:start position:0% +person's traveling at constant speed + + + align:start position:0% +person's traveling at constant speed +that's like Middle School right this is + + align:start position:0% +that's like Middle School right this is + + + align:start position:0% +that's like Middle School right this is +not like why you belaboring this + + align:start position:0% +not like why you belaboring this + + + align:start position:0% +not like why you belaboring this +paragraph after paragraph why are you + + align:start position:0% +paragraph after paragraph why are you + + + align:start position:0% +paragraph after paragraph why are you +using this kind of mock inspired + + align:start position:0% +using this kind of mock inspired + + + align:start position:0% +using this kind of mock inspired +language without even citing as Mark + + align:start position:0% +language without even citing as Mark + + + align:start position:0% +language without even citing as Mark +about how objects should be um subject + + align:start position:0% +about how objects should be um subject + + + align:start position:0% +about how objects should be um subject +to uh empirical measurement why are you + + align:start position:0% +to uh empirical measurement why are you + + + align:start position:0% +to uh empirical measurement why are you +telling me how to have my friend shine a + + align:start position:0% +telling me how to have my friend shine a + + + align:start position:0% +telling me how to have my friend shine a +lantern in my face it's like get to the + + align:start position:0% +lantern in my face it's like get to the + + + align:start position:0% +lantern in my face it's like get to the +point right show me equations show me + + align:start position:0% +point right show me equations show me + + + align:start position:0% +point right show me equations show me +what you're doing show me the + + align:start position:0% +what you're doing show me the + + + align:start position:0% +what you're doing show me the +measurements you've performed in your + + align:start position:0% +measurements you've performed in your + + + align:start position:0% +measurements you've performed in your +laboratory show me the missing factor of + + align:start position:0% +laboratory show me the missing factor of + + + align:start position:0% +laboratory show me the missing factor of +2 pi and maximum equations like do + + align:start position:0% +2 pi and maximum equations like do + + + align:start position:0% +2 pi and maximum equations like do +something right calculate something you + + align:start position:0% +something right calculate something you + + + align:start position:0% +something right calculate something you +lazy dog right I think what minkowski + + align:start position:0% +lazy dog right I think what minkowski + + + align:start position:0% +lazy dog right I think what minkowski +was reacting to was this kind of not + + align:start position:0% +was reacting to was this kind of not + + + align:start position:0% +was reacting to was this kind of not +just a kind of everything's in a + + align:start position:0% +just a kind of everything's in a + + + align:start position:0% +just a kind of everything's in a +specific coordinate basis it's not very + + align:start position:0% +specific coordinate basis it's not very + + + align:start position:0% +specific coordinate basis it's not very +unified or we would we would learn fancy + + align:start position:0% +unified or we would we would learn fancy + + + align:start position:0% +unified or we would we would learn fancy +techniques later it's not just that he + + align:start position:0% +techniques later it's not just that he + + + align:start position:0% +techniques later it's not just that he +doesn't that Einstein + + align:start position:0% +doesn't that Einstein + + + align:start position:0% +doesn't that Einstein +doesn't scale out the speed of light to + + align:start position:0% +doesn't scale out the speed of light to + + + align:start position:0% +doesn't scale out the speed of light to +make things more um you know + + align:start position:0% +make things more um you know + + + align:start position:0% +make things more um you know +dimensionless these are all things that + + align:start position:0% +dimensionless these are all things that + + + align:start position:0% +dimensionless these are all things that +we would admire or come to take to to + + align:start position:0% +we would admire or come to take to to + + + align:start position:0% +we would admire or come to take to to +consider a natural move to make because + + align:start position:0% +consider a natural move to make because + + + align:start position:0% +consider a natural move to make because +on the benefit of work by people like + + align:start position:0% +on the benefit of work by people like + + + align:start position:0% +on the benefit of work by people like +mkowski I think to Mankowski this was + + align:start position:0% +mkowski I think to Mankowski this was + + + align:start position:0% +mkowski I think to Mankowski this was +just a lot of philosophical blah blah + + align:start position:0% +just a lot of philosophical blah blah + + + align:start position:0% +just a lot of philosophical blah blah +blah that wasn't advancing any new + + align:start position:0% +blah that wasn't advancing any new + + + align:start position:0% +blah that wasn't advancing any new +mathematics it wasn't analyzing you know + + align:start position:0% +mathematics it wasn't analyzing you know + + + align:start position:0% +mathematics it wasn't analyzing you know +concrete experiments in a new detail it + + align:start position:0% +concrete experiments in a new detail it + + + align:start position:0% +concrete experiments in a new detail it +wasn't telling us anything new about + + align:start position:0% +wasn't telling us anything new about + + + align:start position:0% +wasn't telling us anything new about +things that other researchers had done + + align:start position:0% +things that other researchers had done + + + align:start position:0% +things that other researchers had done +it was like Hey I read some stuff and I + + align:start position:0% +it was like Hey I read some stuff and I + + + align:start position:0% +it was like Hey I read some stuff and I +think it's confusing the way people talk + + align:start position:0% +think it's confusing the way people talk + + + align:start position:0% +think it's confusing the way people talk +about it I think that was the kind of + + align:start position:0% +about it I think that was the kind of + + + align:start position:0% +about it I think that was the kind of +response from from many readers which is + + align:start position:0% +response from from many readers which is + + + align:start position:0% +response from from many readers which is +why many people ignored it those who + + align:start position:0% +why many people ignored it those who + + + align:start position:0% +why many people ignored it those who +bothered reading past page five said oh + + align:start position:0% +bothered reading past page five said oh + + + align:start position:0% +bothered reading past page five said oh +I've seen that equation before that's + + align:start position:0% +I've seen that equation before that's + + + align:start position:0% +I've seen that equation before that's +just lorenz's stuff oh it's the I it's + + align:start position:0% +just lorenz's stuff oh it's the I it's + + + align:start position:0% +just lorenz's stuff oh it's the I it's +Lorenz Einstein theory right it's I + + align:start position:0% +Lorenz Einstein theory right it's I + + + align:start position:0% +Lorenz Einstein theory right it's I +think it's that kind of response and for + + align:start position:0% +think it's that kind of response and for + + + align:start position:0% +think it's that kind of response and for +Mankowski I think he would have seen an + + align:start position:0% +Mankowski I think he would have seen an + + + align:start position:0% +Mankowski I think he would have seen an +insufficient + + align:start position:0% +insufficient + + + align:start position:0% +insufficient +um precision and Clarity right and now + + align:start position:0% +um precision and Clarity right and now + + + align:start position:0% +um precision and Clarity right and now +that's a that's a value judgment and + + align:start position:0% +that's a that's a value judgment and + + + align:start position:0% +that's a that's a value judgment and +that depends on our own personality but + + align:start position:0% +that depends on our own personality but + + + align:start position:0% +that depends on our own personality but +our own training our own toolkit so for + + align:start position:0% +our own training our own toolkit so for + + + align:start position:0% +our own training our own toolkit so for +minkowski if you're not talking about + + align:start position:0% +minkowski if you're not talking about + + + align:start position:0% +minkowski if you're not talking about +what happens when you perform rotations + + align:start position:0% +what happens when you perform rotations + + + align:start position:0% +what happens when you perform rotations +there should be something invariant like + + align:start position:0% +there should be something invariant like + + + align:start position:0% +there should be something invariant like +that should be Lesson Zero in Geometry + + align:start position:0% +that should be Lesson Zero in Geometry + + + align:start position:0% +that should be Lesson Zero in Geometry +the distance between my house and the + + align:start position:0% +the distance between my house and the + + + align:start position:0% +the distance between my house and the +Town Square hasn't changed even if I + + align:start position:0% +Town Square hasn't changed even if I + + + align:start position:0% +Town Square hasn't changed even if I +rotate you know the street map like who + + align:start position:0% +rotate you know the street map like who + + + align:start position:0% +rotate you know the street map like who +doesn't think of that I think would have + + align:start position:0% +doesn't think of that I think would have + + + align:start position:0% +doesn't think of that I think would have +been minkowski's kind of response + + align:start position:0% +been minkowski's kind of response + + + align:start position:0% +been minkowski's kind of response +there's a you know once you think in a + + align:start position:0% +there's a you know once you think in a + + + align:start position:0% +there's a you know once you think in a +geometrical way according to minkowski + + align:start position:0% +geometrical way according to minkowski + + + align:start position:0% +geometrical way according to minkowski +there should be unavoidable follow-up + + align:start position:0% +there should be unavoidable follow-up + + + align:start position:0% +there should be unavoidable follow-up +questions and this Lazy Dog is too busy + + align:start position:0% +questions and this Lazy Dog is too busy + + + align:start position:0% +questions and this Lazy Dog is too busy +talking about you know he doesn't like + + align:start position:0% +talking about you know he doesn't like + + + align:start position:0% +talking about you know he doesn't like +the way textbooks describe Maxwell like + + align:start position:0% +the way textbooks describe Maxwell like + + + align:start position:0% +the way textbooks describe Maxwell like +I got no time for this I think that + + align:start position:0% +I got no time for this I think that + + + align:start position:0% +I got no time for this I think that +would have been a pretty reasonable + + align:start position:0% +would have been a pretty reasonable + + + align:start position:0% +would have been a pretty reasonable +approximation to his first reaction and + + align:start position:0% +approximation to his first reaction and + + + align:start position:0% +approximation to his first reaction and +then he's like oh actually okay the + + align:start position:0% +then he's like oh actually okay the + + + align:start position:0% +then he's like oh actually okay the +speedway is constant that I can perform + + align:start position:0% +speedway is constant that I can perform + + + align:start position:0% +speedway is constant that I can perform +these very clever sets of rotations and + + align:start position:0% +these very clever sets of rotations and + + + align:start position:0% +these very clever sets of rotations and +of course therefore there's an + + align:start position:0% +of course therefore there's an + + + align:start position:0% +of course therefore there's an +invariance and of course there's an + + align:start position:0% +invariance and of course there's an + + + align:start position:0% +invariance and of course there's an +absolute way right so he he has his own + + align:start position:0% +absolute way right so he he has his own + + + align:start position:0% +absolute way right so he he has his own +he's on his own trade right he's on a + + align:start position:0% +he's on his own trade right he's on a + + + align:start position:0% +he's on his own trade right he's on a +different kind of reference frame so to + + align:start position:0% +different kind of reference frame so to + + + align:start position:0% +different kind of reference frame so to +speak and certain questions are the + + align:start position:0% +speak and certain questions are the + + + align:start position:0% +speak and certain questions are the +obvious next ones to ask because he has + + align:start position:0% +obvious next ones to ask because he has + + + align:start position:0% +obvious next ones to ask because he has +a certain kind of set of tools and + + align:start position:0% +a certain kind of set of tools and + + + align:start position:0% +a certain kind of set of tools and +starting point and that's true of I + + align:start position:0% +starting point and that's true of I + + + align:start position:0% +starting point and that's true of I +think of all of us and we'll see another + + align:start position:0% +think of all of us and we'll see another + + + align:start position:0% +think of all of us and we'll see another +a contrasting example in this next part + + align:start position:0% +a contrasting example in this next part + + + align:start position:0% +a contrasting example in this next part +of today's class we'll see that over and + + align:start position:0% +of today's class we'll see that over and + + + align:start position:0% +of today's class we'll see that over and +over again throughout the turn + + align:start position:0% +over again throughout the turn + + + align:start position:0% +over again throughout the turn +not only about relativity but quantum + + align:start position:0% +not only about relativity but quantum + + + align:start position:0% +not only about relativity but quantum +theory about cosmology about particle + + align:start position:0% +theory about cosmology about particle + + + align:start position:0% +theory about cosmology about particle +physics and here's a kind of early + + align:start position:0% +physics and here's a kind of early + + + align:start position:0% +physics and here's a kind of early +example where you can sink our teeth + + align:start position:0% +example where you can sink our teeth + + + align:start position:0% +example where you can sink our teeth +into it say these people weren't just + + align:start position:0% +into it say these people weren't just + + + align:start position:0% +into it say these people weren't just +like misreading it they were doing + + align:start position:0% +like misreading it they were doing + + + align:start position:0% +like misreading it they were doing +really cool productive stuff some of + + align:start position:0% +really cool productive stuff some of + + + align:start position:0% +really cool productive stuff some of +which we still take advantage of today + + align:start position:0% +which we still take advantage of today + + + align:start position:0% +which we still take advantage of today +uh and yet what they thought they were + + align:start position:0% +uh and yet what they thought they were + + + align:start position:0% +uh and yet what they thought they were +doing is neither what we think we do nor + + align:start position:0% +doing is neither what we think we do nor + + + align:start position:0% +doing is neither what we think we do nor +what you know the original authors + + align:start position:0% +what you know the original authors + + + align:start position:0% +what you know the original authors +thought they were doing so we have this + + align:start position:0% +thought they were doing so we have this + + + align:start position:0% +thought they were doing so we have this +the kind of plasticity of meaning and + + align:start position:0% +the kind of plasticity of meaning and + + + align:start position:0% +the kind of plasticity of meaning and +interpretation even when our equation + + align:start position:0% +interpretation even when our equation + + + align:start position:0% +interpretation even when our equation +when our equations agree perfectly let + + align:start position:0% +when our equations agree perfectly let + + + align:start position:0% +when our equations agree perfectly let +alone when we come up with different + + align:start position:0% +alone when we come up with different + + + align:start position:0% +alone when we come up with different +equations I find that wonderful I love + + align:start position:0% +equations I find that wonderful I love + + + align:start position:0% +equations I find that wonderful I love +that exactly all writing down the same + + align:start position:0% +that exactly all writing down the same + + + align:start position:0% +that exactly all writing down the same +factor gamma that's fantastic right + + align:start position:0% +factor gamma that's fantastic right + + + align:start position:0% +factor gamma that's fantastic right +because then we can really map you know + + align:start position:0% +because then we can really map you know + + + align:start position:0% +because then we can really map you know +what is the same and what's not the same + + align:start position:0% +what is the same and what's not the same + + + align:start position:0% +what is the same and what's not the same +conceptually let alone in the exchange + + align:start position:0% +conceptually let alone in the exchange + + + align:start position:0% +conceptually let alone in the exchange +of light signals so keep that kind of + + align:start position:0% +of light signals so keep that kind of + + + align:start position:0% +of light signals so keep that kind of +question in mind we'll come back to that + + align:start position:0% +question in mind we'll come back to that + + + align:start position:0% +question in mind we'll come back to that +theme really over and over this semester + + align:start position:0% +theme really over and over this semester + + + align:start position:0% +theme really over and over this semester +it's a great question + + align:start position:0% +it's a great question + + + align:start position:0% +it's a great question +let me go on to the last part uh and + + align:start position:0% +let me go on to the last part uh and + + + align:start position:0% +let me go on to the last part uh and +look at our favorite Cambridge Wranglers + + align:start position:0% +look at our favorite Cambridge Wranglers + + + align:start position:0% +look at our favorite Cambridge Wranglers +or at least my favorite camera + + align:start position:0% +or at least my favorite camera + + + align:start position:0% +or at least my favorite camera +so minkowski wasn't the only person who + + align:start position:0% +so minkowski wasn't the only person who + + + align:start position:0% +so minkowski wasn't the only person who +slowly sometimes kind of grudgingly + + align:start position:0% +slowly sometimes kind of grudgingly + + + align:start position:0% +slowly sometimes kind of grudgingly +began to to read Einstein's work on the + + align:start position:0% +began to to read Einstein's work on the + + + align:start position:0% +began to to read Einstein's work on the +electronamics of moving bodies another + + align:start position:0% +electronamics of moving bodies another + + + align:start position:0% +electronamics of moving bodies another +group that really did dig in in pretty + + align:start position:0% +group that really did dig in in pretty + + + align:start position:0% +group that really did dig in in pretty +substantive ways was a subset of these + + align:start position:0% +substantive ways was a subset of these + + + align:start position:0% +substantive ways was a subset of these +Cambridge Wranglers the folks that now + + align:start position:0% +Cambridge Wranglers the folks that now + + + align:start position:0% +Cambridge Wranglers the folks that now +we've talked about a few times at + + align:start position:0% +we've talked about a few times at + + + align:start position:0% +we've talked about a few times at +Cambridge University + + align:start position:0% +Cambridge University + + + align:start position:0% +Cambridge University +for them much like for minkowski there + + align:start position:0% +for them much like for minkowski there + + + align:start position:0% +for them much like for minkowski there +were elements of real value in + + align:start position:0% +were elements of real value in + + + align:start position:0% +were elements of real value in +Einstein's work they just weren't the + + align:start position:0% +Einstein's work they just weren't the + + + align:start position:0% +Einstein's work they just weren't the +same elements that minkowski considered + + align:start position:0% +same elements that minkowski considered + + + align:start position:0% +same elements that minkowski considered +valuable or they're not inside + + align:start position:0% +valuable or they're not inside + + + align:start position:0% +valuable or they're not inside +considered valuable so let's take a + + align:start position:0% +considered valuable so let's take a + + + align:start position:0% +considered valuable so let's take a +little look at the kinds of things that + + align:start position:0% +little look at the kinds of things that + + + align:start position:0% +little look at the kinds of things that +they did with Einstein's paper + + align:start position:0% +they did with Einstein's paper + + + align:start position:0% +they did with Einstein's paper +as a warm-up to make sense of this and + + align:start position:0% +as a warm-up to make sense of this and + + + align:start position:0% +as a warm-up to make sense of this and +by the way for this part of course I'm + + align:start position:0% +by the way for this part of course I'm + + + align:start position:0% +by the way for this part of course I'm +drawing very heavily on the article in + + align:start position:0% +drawing very heavily on the article in + + + align:start position:0% +drawing very heavily on the article in +in the reading for today from uh Andy + + align:start position:0% +in the reading for today from uh Andy + + + align:start position:0% +in the reading for today from uh Andy +Warwick and I'll talk through some of + + align:start position:0% +Warwick and I'll talk through some of + + + align:start position:0% +Warwick and I'll talk through some of +the specifics some of the some of the + + align:start position:0% +the specifics some of the some of the + + + align:start position:0% +the specifics some of the some of the +details of the article might be pretty + + align:start position:0% +details of the article might be pretty + + + align:start position:0% +details of the article might be pretty +confusing so we'll talk through what + + align:start position:0% +confusing so we'll talk through what + + + align:start position:0% +confusing so we'll talk through what +what were they doing at least a little + + align:start position:0% +what were they doing at least a little + + + align:start position:0% +what were they doing at least a little +bit more the historical point I want to + + align:start position:0% +bit more the historical point I want to + + + align:start position:0% +bit more the historical point I want to +clarify is really just like minkowski in + + align:start position:0% +clarify is really just like minkowski in + + + align:start position:0% +clarify is really just like minkowski in +the sense that very smart professional + + align:start position:0% +the sense that very smart professional + + + align:start position:0% +the sense that very smart professional +researchers were making sense of + + align:start position:0% +researchers were making sense of + + + align:start position:0% +researchers were making sense of +Einstein's work differently than + + align:start position:0% +Einstein's work differently than + + + align:start position:0% +Einstein's work differently than +Einstein did and that didn't make them + + align:start position:0% +Einstein did and that didn't make them + + + align:start position:0% +Einstein did and that didn't make them +wrong and made them it indicates that + + align:start position:0% +wrong and made them it indicates that + + + align:start position:0% +wrong and made them it indicates that +they were finding elements of value out + + align:start position:0% +they were finding elements of value out + + + align:start position:0% +they were finding elements of value out +of interest in Einstein's work different + + align:start position:0% +of interest in Einstein's work different + + + align:start position:0% +of interest in Einstein's work different +from Einstein's own and sometimes + + align:start position:0% +from Einstein's own and sometimes + + + align:start position:0% +from Einstein's own and sometimes +different from ARA that's the historical + + align:start position:0% +different from ARA that's the historical + + + align:start position:0% +different from ARA that's the historical +lesson and if you get a little bit lost + + align:start position:0% +lesson and if you get a little bit lost + + + align:start position:0% +lesson and if you get a little bit lost +with image charges and conformal + + align:start position:0% +with image charges and conformal + + + align:start position:0% +with image charges and conformal +Transformations that's okay in this + + align:start position:0% +Transformations that's okay in this + + + align:start position:0% +Transformations that's okay in this +class especially that's okay but I + + align:start position:0% +class especially that's okay but I + + + align:start position:0% +class especially that's okay but I +figure it's still fun to see what were + + align:start position:0% +figure it's still fun to see what were + + + align:start position:0% +figure it's still fun to see what were +they really doing because that's what + + align:start position:0% +they really doing because that's what + + + align:start position:0% +they really doing because that's what +we're going to talk about + + align:start position:0% +we're going to talk about + + + align:start position:0% +we're going to talk about +a little bit here so many of you again + + align:start position:0% +a little bit here so many of you again + + + align:start position:0% +a little bit here so many of you again +might have seen in even maybe in high + + align:start position:0% +might have seen in even maybe in high + + + align:start position:0% +might have seen in even maybe in high +school classes on electricity to + + align:start position:0% +school classes on electricity to + + + align:start position:0% +school classes on electricity to +magnetism there are all these really + + align:start position:0% +magnetism there are all these really + + + align:start position:0% +magnetism there are all these really +clever tricks uh that we that we still + + align:start position:0% +clever tricks uh that we that we still + + + align:start position:0% +clever tricks uh that we that we still +take advantage of to try to make pretty + + align:start position:0% +take advantage of to try to make pretty + + + align:start position:0% +take advantage of to try to make pretty +complicated problems simpler and yet can + + align:start position:0% +complicated problems simpler and yet can + + + align:start position:0% +complicated problems simpler and yet can +still get Exact Solutions one of those + + align:start position:0% +still get Exact Solutions one of those + + + align:start position:0% +still get Exact Solutions one of those +that we learned pretty early on + + align:start position:0% +that we learned pretty early on + + + align:start position:0% +that we learned pretty early on +is called the message the method of + + align:start position:0% +is called the message the method of + + + align:start position:0% +is called the message the method of +image charges and electrostatics so + + align:start position:0% +image charges and electrostatics so + + + align:start position:0% +image charges and electrostatics so +let's say some Nene some one of my mean + + align:start position:0% +let's say some Nene some one of my mean + + + align:start position:0% +let's say some Nene some one of my mean +old colleagues in the department of + + align:start position:0% +old colleagues in the department of + + + align:start position:0% +old colleagues in the department of +physics assigned to you the problem to + + align:start position:0% +physics assigned to you the problem to + + + align:start position:0% +physics assigned to you the problem to +solve for the the state of the electric + + align:start position:0% +solve for the the state of the electric + + + align:start position:0% +solve for the the state of the electric +field + + align:start position:0% +field + + + align:start position:0% +field +between a stationary uh Point charge + + align:start position:0% +between a stationary uh Point charge + + + align:start position:0% +between a stationary uh Point charge +with a positive charge some charge plus + + align:start position:0% +with a positive charge some charge plus + + + align:start position:0% +with a positive charge some charge plus +q and some infinite an extent some + + align:start position:0% +q and some infinite an extent some + + + align:start position:0% +q and some infinite an extent some +infinitely long perfectly flat + + align:start position:0% +infinitely long perfectly flat + + + align:start position:0% +infinitely long perfectly flat +conducting plate that's sort of grounded + + align:start position:0% +conducting plate that's sort of grounded + + + align:start position:0% +conducting plate that's sort of grounded +that's kind of a pain in the neck to + + align:start position:0% +that's kind of a pain in the neck to + + + align:start position:0% +that's kind of a pain in the neck to +find the exact uh value of the electric + + align:start position:0% +find the exact uh value of the electric + + + align:start position:0% +find the exact uh value of the electric +field that it's a vector quantity if the + + align:start position:0% +field that it's a vector quantity if the + + + align:start position:0% +field that it's a vector quantity if the +you know worry about how it's changing + + align:start position:0% +you know worry about how it's changing + + + align:start position:0% +you know worry about how it's changing +through space so one thing that you may + + align:start position:0% +through space so one thing that you may + + + align:start position:0% +through space so one thing that you may +remember from studying Max's equations + + align:start position:0% +remember from studying Max's equations + + + align:start position:0% +remember from studying Max's equations +is that for this kind of scenario the + + align:start position:0% +is that for this kind of scenario the + + + align:start position:0% +is that for this kind of scenario the +field lines of the electric field almost + + align:start position:0% +field lines of the electric field almost + + + align:start position:0% +field lines of the electric field almost +intersect the plate at right angles + + align:start position:0% +intersect the plate at right angles + + + align:start position:0% +intersect the plate at right angles +that's that's to remain consistent with + + align:start position:0% +that's that's to remain consistent with + + + align:start position:0% +that's that's to remain consistent with +the fact this is a grounded conducting + + align:start position:0% +the fact this is a grounded conducting + + + align:start position:0% +the fact this is a grounded conducting +plate if they didn't all intersect at + + align:start position:0% +plate if they didn't all intersect at + + + align:start position:0% +plate if they didn't all intersect at +right angles you actually build up a + + align:start position:0% +right angles you actually build up a + + + align:start position:0% +right angles you actually build up a +voltage difference it would not satisfy + + align:start position:0% +voltage difference it would not satisfy + + + align:start position:0% +voltage difference it would not satisfy +the boundary conditions of the problem + + align:start position:0% +the boundary conditions of the problem + + + align:start position:0% +the boundary conditions of the problem +it's kind of a pain in the neck meanies + + align:start position:0% +it's kind of a pain in the neck meanies + + + align:start position:0% +it's kind of a pain in the neck meanies +so there's a pretty clever trick we can + + align:start position:0% +so there's a pretty clever trick we can + + + align:start position:0% +so there's a pretty clever trick we can +solve a much much simpler mathematical + + align:start position:0% +solve a much much simpler mathematical + + + align:start position:0% +solve a much much simpler mathematical +setup to get the exact solution for the + + align:start position:0% +setup to get the exact solution for the + + + align:start position:0% +setup to get the exact solution for the +original problem + + align:start position:0% +original problem + + + align:start position:0% +original problem +forget about the plate throw the plate + + align:start position:0% +forget about the plate throw the plate + + + align:start position:0% +forget about the plate throw the plate +away right in it for a few steps and + + align:start position:0% +away right in it for a few steps and + + + align:start position:0% +away right in it for a few steps and +instead insert a second Point charge of + + align:start position:0% +instead insert a second Point charge of + + + align:start position:0% +instead insert a second Point charge of +equal but opposite sign people equal + + align:start position:0% +equal but opposite sign people equal + + + align:start position:0% +equal but opposite sign people equal +magnitude but opposite sign so now in + + align:start position:0% +magnitude but opposite sign so now in + + + align:start position:0% +magnitude but opposite sign so now in +this new scenario we pretend there's no + + align:start position:0% +this new scenario we pretend there's no + + + align:start position:0% +this new scenario we pretend there's no +nothing physical here but we have an + + align:start position:0% +nothing physical here but we have an + + + align:start position:0% +nothing physical here but we have an +equal distance away from that where the + + align:start position:0% +equal distance away from that where the + + + align:start position:0% +equal distance away from that where the +plate had been in the original problem + + align:start position:0% +plate had been in the original problem + + + align:start position:0% +plate had been in the original problem +we put down an imaginary image charge + + align:start position:0% +we put down an imaginary image charge + + + align:start position:0% +we put down an imaginary image charge +that has a negative uh charge but the + + align:start position:0% +that has a negative uh charge but the + + + align:start position:0% +that has a negative uh charge but the +same magnitude as the original uh + + align:start position:0% +same magnitude as the original uh + + + align:start position:0% +same magnitude as the original uh +positive charge now we can easily solve + + align:start position:0% +positive charge now we can easily solve + + + align:start position:0% +positive charge now we can easily solve +for a much more easily solved for the + + align:start position:0% +for a much more easily solved for the + + + align:start position:0% +for a much more easily solved for the +value of the electrostatic potential + + align:start position:0% +value of the electrostatic potential + + + align:start position:0% +value of the electrostatic potential +it's just two bodies it just uh you know + + align:start position:0% +it's just two bodies it just uh you know + + + align:start position:0% +it's just two bodies it just uh you know +goes like a one over R between them we + + align:start position:0% +goes like a one over R between them we + + + align:start position:0% +goes like a one over R between them we +can take the gradient see how that + + align:start position:0% +can take the gradient see how that + + + align:start position:0% +can take the gradient see how that +changes through space we can do + + align:start position:0% +changes through space we can do + + + align:start position:0% +changes through space we can do +everything we was asked to do to solve + + align:start position:0% +everything we was asked to do to solve + + + align:start position:0% +everything we was asked to do to solve +for the exact behavior of the electric + + align:start position:0% +for the exact behavior of the electric + + + align:start position:0% +for the exact behavior of the electric +field by replacing one problem with a + + align:start position:0% +field by replacing one problem with a + + + align:start position:0% +field by replacing one problem with a +simpler but equivalent one okay that's + + align:start position:0% +simpler but equivalent one okay that's + + + align:start position:0% +simpler but equivalent one okay that's +the method of image charges you can + + align:start position:0% +the method of image charges you can + + + align:start position:0% +the method of image charges you can +learn about that on Wikipedia or on any + + align:start position:0% +learn about that on Wikipedia or on any + + + align:start position:0% +learn about that on Wikipedia or on any +e m textbook it's a standard technique + + align:start position:0% +e m textbook it's a standard technique + + + align:start position:0% +e m textbook it's a standard technique +that goes back really century it's + + align:start position:0% +that goes back really century it's + + + align:start position:0% +that goes back really century it's +pretty powerful well that's baby stuff + + align:start position:0% +pretty powerful well that's baby stuff + + + align:start position:0% +pretty powerful well that's baby stuff +right we're talking about Cambridge + + align:start position:0% +right we're talking about Cambridge + + + align:start position:0% +right we're talking about Cambridge +Wranglers here or for that matter MIT + + align:start position:0% +Wranglers here or for that matter MIT + + + align:start position:0% +Wranglers here or for that matter MIT +students we don't have to do one single + + align:start position:0% +students we don't have to do one single + + + align:start position:0% +students we don't have to do one single +point charge behind what would have been + + align:start position:0% +point charge behind what would have been + + + align:start position:0% +point charge behind what would have been +an infinite unbending conducting plate + + align:start position:0% +an infinite unbending conducting plate + + + align:start position:0% +an infinite unbending conducting plate +that is boring let's do some crazy stuff + + align:start position:0% +that is boring let's do some crazy stuff + + + align:start position:0% +that is boring let's do some crazy stuff +and that's what the Wranglers got very + + align:start position:0% +and that's what the Wranglers got very + + + align:start position:0% +and that's what the Wranglers got very +good at doing with their personal tutors + + align:start position:0% +good at doing with their personal tutors + + + align:start position:0% +good at doing with their personal tutors +for the tripods exam so a very similar + + align:start position:0% +for the tripods exam so a very similar + + + align:start position:0% +for the tripods exam so a very similar +related technique became known as the + + align:start position:0% +related technique became known as the + + + align:start position:0% +related technique became known as the +method of inversion and that's again + + align:start position:0% +method of inversion and that's again + + + align:start position:0% +method of inversion and that's again +really just mapping a difficult problem + + align:start position:0% +really just mapping a difficult problem + + + align:start position:0% +really just mapping a difficult problem +into a simpler one and again this this + + align:start position:0% +into a simpler one and again this this + + + align:start position:0% +into a simpler one and again this this +illustration is taken from Andy + + align:start position:0% +illustration is taken from Andy + + + align:start position:0% +illustration is taken from Andy +Warwick's article uh which that is + + align:start position:0% +Warwick's article uh which that is + + + align:start position:0% +Warwick's article uh which that is +elaborate upon in in this book of his + + align:start position:0% +elaborate upon in in this book of his + + + align:start position:0% +elaborate upon in in this book of his +that I really can't recommend strongly + + align:start position:0% +that I really can't recommend strongly + + + align:start position:0% +that I really can't recommend strongly +enough I love this book masters of + + align:start position:0% +enough I love this book masters of + + + align:start position:0% +enough I love this book masters of +theory but the article itself really + + align:start position:0% +theory but the article itself really + + + align:start position:0% +theory but the article itself really +gets this this part this part across + + align:start position:0% +gets this this part this part across + + + align:start position:0% +gets this this part this part across +let's first do a little geometry a + + align:start position:0% +let's first do a little geometry a + + + align:start position:0% +let's first do a little geometry a +little mapping exercise which is what + + align:start position:0% +little mapping exercise which is what + + + align:start position:0% +little mapping exercise which is what +the Wranglers would have learned to do + + align:start position:0% +the Wranglers would have learned to do + + + align:start position:0% +the Wranglers would have learned to do +very early with their coaches take any + + align:start position:0% +very early with their coaches take any + + + align:start position:0% +very early with their coaches take any +single point a here's the point a for + + align:start position:0% +single point a here's the point a for + + + align:start position:0% +single point a here's the point a for +our case any point that happens to be + + align:start position:0% +our case any point that happens to be + + + align:start position:0% +our case any point that happens to be +inside a circle of radius K so the point + + align:start position:0% +inside a circle of radius K so the point + + + align:start position:0% +inside a circle of radius K so the point +a is clearly contained within that + + align:start position:0% +a is clearly contained within that + + + align:start position:0% +a is clearly contained within that +Circle + + align:start position:0% +Circle + + + align:start position:0% +Circle +we can then do a unique mapping to an + + align:start position:0% +we can then do a unique mapping to an + + + align:start position:0% +we can then do a unique mapping to an +inverse Point kind of like that where we + + align:start position:0% +inverse Point kind of like that where we + + + align:start position:0% +inverse Point kind of like that where we +place our image charge from the past + + align:start position:0% +place our image charge from the past + + + align:start position:0% +place our image charge from the past +example there's a one-to-one map for a + + align:start position:0% +example there's a one-to-one map for a + + + align:start position:0% +example there's a one-to-one map for a +point corresponding uniquely to that + + align:start position:0% +point corresponding uniquely to that + + + align:start position:0% +point corresponding uniquely to that +point a that's now outside the circle + + align:start position:0% +point a that's now outside the circle + + + align:start position:0% +point a that's now outside the circle +and so the way we determine where that + + align:start position:0% +and so the way we determine where that + + + align:start position:0% +and so the way we determine where that +point would be is by requiring the + + align:start position:0% +point would be is by requiring the + + + align:start position:0% +point would be is by requiring the +distance from the center of the circle + + align:start position:0% +distance from the center of the circle + + + align:start position:0% +distance from the center of the circle +to our original point that distance o a + + align:start position:0% +to our original point that distance o a + + + align:start position:0% +to our original point that distance o a +times the distance between uh the center + + align:start position:0% +times the distance between uh the center + + + align:start position:0% +times the distance between uh the center +of the circle and the new point the + + align:start position:0% +of the circle and the new point the + + + align:start position:0% +of the circle and the new point the +inverse point the product of those + + align:start position:0% +inverse point the product of those + + + align:start position:0% +inverse point the product of those +distances must equal the square of this + + align:start position:0% +distances must equal the square of this + + + align:start position:0% +distances must equal the square of this +radius that's enough to do this mapping + + align:start position:0% +radius that's enough to do this mapping + + + align:start position:0% +radius that's enough to do this mapping +this is actually called a conformal map + + align:start position:0% +this is actually called a conformal map + + + align:start position:0% +this is actually called a conformal map +now what if there was some point uh the + + align:start position:0% +now what if there was some point uh the + + + align:start position:0% +now what if there was some point uh the +point a is actually moving along this + + align:start position:0% +point a is actually moving along this + + + align:start position:0% +point a is actually moving along this +curve this orange curve between points p + + align:start position:0% +curve this orange curve between points p + + + align:start position:0% +curve this orange curve between points p +and Q we can imagine it knows a whole + + align:start position:0% +and Q we can imagine it knows a whole + + + align:start position:0% +and Q we can imagine it knows a whole +set of points Each of which lies + + align:start position:0% +set of points Each of which lies + + + align:start position:0% +set of points Each of which lies +entirely within this original Circle + + align:start position:0% +entirely within this original Circle + + + align:start position:0% +entirely within this original Circle +for each of these points along the + + align:start position:0% +for each of these points along the + + + align:start position:0% +for each of these points along the +orange curve between p and Q we can do + + align:start position:0% +orange curve between p and Q we can do + + + align:start position:0% +orange curve between p and Q we can do +the same trick we can map them to each + + align:start position:0% +the same trick we can map them to each + + + align:start position:0% +the same trick we can map them to each +of their corresponding inverse points + + align:start position:0% +of their corresponding inverse points + + + align:start position:0% +of their corresponding inverse points +for every single point along this orange + + align:start position:0% +for every single point along this orange + + + align:start position:0% +for every single point along this orange +curve we we require this relationship to + + align:start position:0% +curve we we require this relationship to + + + align:start position:0% +curve we we require this relationship to +hold and we map them to an inverse Arc a + + align:start position:0% +hold and we map them to an inverse Arc a + + + align:start position:0% +hold and we map them to an inverse Arc a +collection of inverse points that are + + align:start position:0% +collection of inverse points that are + + + align:start position:0% +collection of inverse points that are +entirely outside the circle so if we + + align:start position:0% +entirely outside the circle so if we + + + align:start position:0% +entirely outside the circle so if we +imagine swooping from P from point P to + + align:start position:0% +imagine swooping from P from point P to + + + align:start position:0% +imagine swooping from P from point P to +Q within that Circle the mapped motion + + align:start position:0% +Q within that Circle the mapped motion + + + align:start position:0% +Q within that Circle the mapped motion +the uniquely corresponding motion would + + align:start position:0% +the uniquely corresponding motion would + + + align:start position:0% +the uniquely corresponding motion would +swoop from point P Prime to Q Prime + + align:start position:0% +swoop from point P Prime to Q Prime + + + align:start position:0% +swoop from point P Prime to Q Prime +now this transformation is called a + + align:start position:0% +now this transformation is called a + + + align:start position:0% +now this transformation is called a +conformal transformation we use this all + + align:start position:0% +conformal transformation we use this all + + + align:start position:0% +conformal transformation we use this all +the time I use these all the time even + + align:start position:0% +the time I use these all the time even + + + align:start position:0% +the time I use these all the time even +to this day in my own physical search + + align:start position:0% +to this day in my own physical search + + + align:start position:0% +to this day in my own physical search +they're really really helpful in topics + + align:start position:0% +they're really really helpful in topics + + + align:start position:0% +they're really really helpful in topics +like general relativity and cosmology + + align:start position:0% +like general relativity and cosmology + + + align:start position:0% +like general relativity and cosmology +the Wranglers were doing this for + + align:start position:0% +the Wranglers were doing this for + + + align:start position:0% +the Wranglers were doing this for +electrostatics uh to get ready for their + + align:start position:0% +electrostatics uh to get ready for their + + + align:start position:0% +electrostatics uh to get ready for their +for their exam so this transformation + + align:start position:0% +for their exam so this transformation + + + align:start position:0% +for their exam so this transformation +preserves angles the angles between any + + align:start position:0% +preserves angles the angles between any + + + align:start position:0% +preserves angles the angles between any +of these arcs any of these line segments + + align:start position:0% +of these arcs any of these line segments + + + align:start position:0% +of these arcs any of these line segments +this angle marks W here those angles are + + align:start position:0% +this angle marks W here those angles are + + + align:start position:0% +this angle marks W here those angles are +preserved the lengths are not you can + + align:start position:0% +preserved the lengths are not you can + + + align:start position:0% +preserved the lengths are not you can +see the line segment PQ is clearly a + + align:start position:0% +see the line segment PQ is clearly a + + + align:start position:0% +see the line segment PQ is clearly a +shorter overall length the distance + + align:start position:0% +shorter overall length the distance + + + align:start position:0% +shorter overall length the distance +between points p and Q is shorter than + + align:start position:0% +between points p and Q is shorter than + + + align:start position:0% +between points p and Q is shorter than +the distance between the corresponding + + align:start position:0% +the distance between the corresponding + + + align:start position:0% +the distance between the corresponding +inverse points P Prime and Q Prime so + + align:start position:0% +inverse points P Prime and Q Prime so + + + align:start position:0% +inverse points P Prime and Q Prime so +very generally conformal Transformations + + align:start position:0% +very generally conformal Transformations + + + align:start position:0% +very generally conformal Transformations +preserve angles but not lengths if that + + align:start position:0% +preserve angles but not lengths if that + + + align:start position:0% +preserve angles but not lengths if that +sounds confusing to you you're in good + + align:start position:0% +sounds confusing to you you're in good + + + align:start position:0% +sounds confusing to you you're in good +company the point is that's the kind of + + align:start position:0% +company the point is that's the kind of + + + align:start position:0% +company the point is that's the kind of +stuff these Wranglers would have learned + + align:start position:0% +stuff these Wranglers would have learned + + + align:start position:0% +stuff these Wranglers would have learned +with their coaches pretty early there + + align:start position:0% +with their coaches pretty early there + + + align:start position:0% +with their coaches pretty early there +are properties of these geometrical + + align:start position:0% +are properties of these geometrical + + + align:start position:0% +are properties of these geometrical +Transformations the upshot of which is + + align:start position:0% +Transformations the upshot of which is + + + align:start position:0% +Transformations the upshot of which is +to make complicated problems uh easier + + align:start position:0% +to make complicated problems uh easier + + + align:start position:0% +to make complicated problems uh easier +so now let's get to an actual tripos + + align:start position:0% +so now let's get to an actual tripos + + + align:start position:0% +so now let's get to an actual tripos +type problem now let's say because + + align:start position:0% +type problem now let's say because + + + align:start position:0% +type problem now let's say because +you're at Cambridge in you know 1880 or + + align:start position:0% +you're at Cambridge in you know 1880 or + + + align:start position:0% +you're at Cambridge in you know 1880 or +1890 they don't ask you to solve for the + + align:start position:0% +1890 they don't ask you to solve for the + + + align:start position:0% +1890 they don't ask you to solve for the +field between a static positive charge + + align:start position:0% +field between a static positive charge + + + align:start position:0% +field between a static positive charge +and an infinite conducting plate come on + + align:start position:0% +and an infinite conducting plate come on + + + align:start position:0% +and an infinite conducting plate come on +we're wrinkles instead we want to solve + + align:start position:0% +we're wrinkles instead we want to solve + + + align:start position:0% +we're wrinkles instead we want to solve +for the electric field lines or or let's + + align:start position:0% +for the electric field lines or or let's + + + align:start position:0% +for the electric field lines or or let's +say the equipotential surfaces where the + + align:start position:0% +say the equipotential surfaces where the + + + align:start position:0% +say the equipotential surfaces where the +electrostatic potential is equal so + + align:start position:0% +electrostatic potential is equal so + + + align:start position:0% +electrostatic potential is equal so +equivalential surface due to a single + + align:start position:0% +equivalential surface due to a single + + + align:start position:0% +equivalential surface due to a single +charge at + + align:start position:0% +charge at + + + align:start position:0% +charge at +um at location o + + align:start position:0% +um at location o + + + align:start position:0% +um at location o +that's near a grounded conducting sphere + + align:start position:0% +that's near a grounded conducting sphere + + + align:start position:0% +that's near a grounded conducting sphere +of centered at B so here is an actual + + align:start position:0% +of centered at B so here is an actual + + + align:start position:0% +of centered at B so here is an actual +physical parts of our problem some + + align:start position:0% +physical parts of our problem some + + + align:start position:0% +physical parts of our problem some +charge here sitting at rest + + align:start position:0% +charge here sitting at rest + + + align:start position:0% +charge here sitting at rest +electrostatics some electric charge at + + align:start position:0% +electrostatics some electric charge at + + + align:start position:0% +electrostatics some electric charge at +Point O that's near some spherical + + align:start position:0% +Point O that's near some spherical + + + align:start position:0% +Point O that's near some spherical +grounded conducting sphere there's a + + align:start position:0% +grounded conducting sphere there's a + + + align:start position:0% +grounded conducting sphere there's a +harder version than our infinite plane + + align:start position:0% +harder version than our infinite plane + + + align:start position:0% +harder version than our infinite plane +well let's use this method of inversion + + align:start position:0% +well let's use this method of inversion + + + align:start position:0% +well let's use this method of inversion +to treat what turns out to be a much + + align:start position:0% +to treat what turns out to be a much + + + align:start position:0% +to treat what turns out to be a much +simpler problem so we have to map the + + align:start position:0% +simpler problem so we have to map the + + + align:start position:0% +simpler problem so we have to map the +simpler version First + + align:start position:0% +simpler version First + + + align:start position:0% +simpler version First +instead of considering either Point O or + + align:start position:0% +instead of considering either Point O or + + + align:start position:0% +instead of considering either Point O or +this conducting sphere B we introduce + + align:start position:0% +this conducting sphere B we introduce + + + align:start position:0% +this conducting sphere B we introduce +the equivalent of a kind of image charge + + align:start position:0% +the equivalent of a kind of image charge + + + align:start position:0% +the equivalent of a kind of image charge +we consider a Charged conducting sphere + + align:start position:0% +we consider a Charged conducting sphere + + + align:start position:0% +we consider a Charged conducting sphere +set you to point a we put in this in + + align:start position:0% +set you to point a we put in this in + + + align:start position:0% +set you to point a we put in this in +this like our image charge our new + + align:start position:0% +this like our image charge our new + + + align:start position:0% +this like our image charge our new +geometrical simplified system some + + align:start position:0% +geometrical simplified system some + + + align:start position:0% +geometrical simplified system some +positive charge and a sphere at a then + + align:start position:0% +positive charge and a sphere at a then + + + align:start position:0% +positive charge and a sphere at a then +we draw the field lines and the + + align:start position:0% +we draw the field lines and the + + + align:start position:0% +we draw the field lines and the +equipotential surfaces for that now + + align:start position:0% +equipotential surfaces for that now + + + align:start position:0% +equipotential surfaces for that now +that's very easy it's just a sphere + + align:start position:0% +that's very easy it's just a sphere + + + align:start position:0% +that's very easy it's just a sphere +they're just going to be sort of + + align:start position:0% +they're just going to be sort of + + + align:start position:0% +they're just going to be sort of +concentric circles around it for the + + align:start position:0% +concentric circles around it for the + + + align:start position:0% +concentric circles around it for the +equipotential surfaces the field is just + + align:start position:0% +equipotential surfaces the field is just + + + align:start position:0% +equipotential surfaces the field is just +you know radial it goes back to like + + align:start position:0% +you know radial it goes back to like + + + align:start position:0% +you know radial it goes back to like +like Faraday's lines of force it + + align:start position:0% +like Faraday's lines of force it + + + align:start position:0% +like Faraday's lines of force it +couldn't be easier for these Wranglers + + align:start position:0% +couldn't be easier for these Wranglers + + + align:start position:0% +couldn't be easier for these Wranglers +now we use that method of inversion to + + align:start position:0% +now we use that method of inversion to + + + align:start position:0% +now we use that method of inversion to +map it back to the original problem + + align:start position:0% +map it back to the original problem + + + align:start position:0% +map it back to the original problem +we're going to close this imaginary + + align:start position:0% +we're going to close this imaginary + + + align:start position:0% +we're going to close this imaginary +object a in a sphere of radius k + + align:start position:0% +object a in a sphere of radius k + + + align:start position:0% +object a in a sphere of radius k +and then we'll map every point along + + align:start position:0% +and then we'll map every point along + + + align:start position:0% +and then we'll map every point along +this orange curve to the corresponding + + align:start position:0% +this orange curve to the corresponding + + + align:start position:0% +this orange curve to the corresponding +uh image points outside of our Circle + + align:start position:0% +uh image points outside of our Circle + + + align:start position:0% +uh image points outside of our Circle +and now we've mapped the equipotential + + align:start position:0% +and now we've mapped the equipotential + + + align:start position:0% +and now we've mapped the equipotential +surfaces for the original problem based + + align:start position:0% +surfaces for the original problem based + + + align:start position:0% +surfaces for the original problem based +on this much simplified problem if + + align:start position:0% +on this much simplified problem if + + + align:start position:0% +on this much simplified problem if +that's confusing to you first of all + + align:start position:0% +that's confusing to you first of all + + + align:start position:0% +that's confusing to you first of all +good you've led a healthy life + + align:start position:0% +good you've led a healthy life + + + align:start position:0% +good you've led a healthy life +um it is not on the exam this is just + + align:start position:0% +um it is not on the exam this is just + + + align:start position:0% +um it is not on the exam this is just +meant to be an example to make sure that + + align:start position:0% +meant to be an example to make sure that + + + align:start position:0% +meant to be an example to make sure that +the kind of reasoning that these that + + align:start position:0% +the kind of reasoning that these that + + + align:start position:0% +the kind of reasoning that these that +these Wranglers would have been immersed + + align:start position:0% +these Wranglers would have been immersed + + + align:start position:0% +these Wranglers would have been immersed +in of the sort we've seen a few times + + align:start position:0% +in of the sort we've seen a few times + + + align:start position:0% +in of the sort we've seen a few times +this is like standard tripod stuff + + align:start position:0% +this is like standard tripod stuff + + + align:start position:0% +this is like standard tripod stuff +I remember unlike um us here at MIT the + + align:start position:0% +I remember unlike um us here at MIT the + + + align:start position:0% +I remember unlike um us here at MIT the +undergraduates of Cambridge in the 1880s + + align:start position:0% +undergraduates of Cambridge in the 1880s + + + align:start position:0% +undergraduates of Cambridge in the 1880s +would have done all this on a timed exam + + align:start position:0% +would have done all this on a timed exam + + + align:start position:0% +would have done all this on a timed exam +that determined the graduation Rank and + + align:start position:0% +that determined the graduation Rank and + + + align:start position:0% +that determined the graduation Rank and +would be published in the National + + align:start position:0% +would be published in the National + + + align:start position:0% +would be published in the National +newspaper so we won't ask them so now + + align:start position:0% +newspaper so we won't ask them so now + + + align:start position:0% +newspaper so we won't ask them so now +let's come back to what Andy's writing + + align:start position:0% +let's come back to what Andy's writing + + + align:start position:0% +let's come back to what Andy's writing +about uh in this article this method of + + align:start position:0% +about uh in this article this method of + + + align:start position:0% +about uh in this article this method of +inversion and these geometrical + + align:start position:0% +inversion and these geometrical + + + align:start position:0% +inversion and these geometrical +techniques like informal Transformations + + align:start position:0% +techniques like informal Transformations + + + align:start position:0% +techniques like informal Transformations +that was like daily stuff for these + + align:start position:0% +that was like daily stuff for these + + + align:start position:0% +that was like daily stuff for these +Kings Wranglers uh by 1900. + + align:start position:0% +Kings Wranglers uh by 1900. + + + align:start position:0% +Kings Wranglers uh by 1900. +these techniques apply to electrostatics + + align:start position:0% +these techniques apply to electrostatics + + + align:start position:0% +these techniques apply to electrostatics +right imagine you have a fixed charge + + align:start position:0% +right imagine you have a fixed charge + + + align:start position:0% +right imagine you have a fixed charge +sitting still at Point o a a fixed + + align:start position:0% +sitting still at Point o a a fixed + + + align:start position:0% +sitting still at Point o a a fixed +grounded sphere nothing changes over + + align:start position:0% +grounded sphere nothing changes over + + + align:start position:0% +grounded sphere nothing changes over +time and that is to say a little more + + align:start position:0% +time and that is to say a little more + + + align:start position:0% +time and that is to say a little more +quantitatively you're always solving for + + align:start position:0% +quantitatively you're always solving for + + + align:start position:0% +quantitatively you're always solving for +situations in which the electric + + align:start position:0% +situations in which the electric + + + align:start position:0% +situations in which the electric +potential is not varying it's a problem + + align:start position:0% +potential is not varying it's a problem + + + align:start position:0% +potential is not varying it's a problem +in electrostatics not varying over time + + align:start position:0% +in electrostatics not varying over time + + + align:start position:0% +in electrostatics not varying over time +even though it varies over space + + align:start position:0% +even though it varies over space + + + align:start position:0% +even though it varies over space +so what these young recent Wranglers + + align:start position:0% +so what these young recent Wranglers + + + align:start position:0% +so what these young recent Wranglers +wanted to do Ebenezer Cunningham and + + align:start position:0% +wanted to do Ebenezer Cunningham and + + + align:start position:0% +wanted to do Ebenezer Cunningham and +Harry Bateman was to actually use + + align:start position:0% +Harry Bateman was to actually use + + + align:start position:0% +Harry Bateman was to actually use +Einstein's work to tackle a problem they + + align:start position:0% +Einstein's work to tackle a problem they + + + align:start position:0% +Einstein's work to tackle a problem they +cared about + + align:start position:0% +cared about + + + align:start position:0% +cared about +which is to generalize these inversion + + align:start position:0% +which is to generalize these inversion + + + align:start position:0% +which is to generalize these inversion +problems and conformal transformations + + align:start position:0% +problems and conformal transformations + + + align:start position:0% +problems and conformal transformations +to situations where objects might be + + align:start position:0% +to situations where objects might be + + + align:start position:0% +to situations where objects might be +moving around to electrodynamics of + + align:start position:0% +moving around to electrodynamics of + + + align:start position:0% +moving around to electrodynamics of +moving bodies not to electrostatics you + + align:start position:0% +moving bodies not to electrostatics you + + + align:start position:0% +moving bodies not to electrostatics you +can see why Einstein that the title of + + align:start position:0% +can see why Einstein that the title of + + + align:start position:0% +can see why Einstein that the title of +Einstein's paper would have caught their + + align:start position:0% +Einstein's paper would have caught their + + + align:start position:0% +Einstein's paper would have caught their +attention they wanted to understand how + + align:start position:0% +attention they wanted to understand how + + + align:start position:0% +attention they wanted to understand how +to generalize these randomly-like + + align:start position:0% +to generalize these randomly-like + + + align:start position:0% +to generalize these randomly-like +techniques to the question of the + + align:start position:0% +techniques to the question of the + + + align:start position:0% +techniques to the question of the +electrodynamics of moving bodies and + + align:start position:0% +electrodynamics of moving bodies and + + + align:start position:0% +electrodynamics of moving bodies and +they thought Einstein's paper had some + + align:start position:0% +they thought Einstein's paper had some + + + align:start position:0% +they thought Einstein's paper had some +pretty clever Tools in there to do that + + align:start position:0% +pretty clever Tools in there to do that + + + align:start position:0% +pretty clever Tools in there to do that +so they could identify using Einstein's + + align:start position:0% +so they could identify using Einstein's + + + align:start position:0% +so they could identify using Einstein's +work all the Transformations which we + + align:start position:0% +work all the Transformations which we + + + align:start position:0% +work all the Transformations which we +would Now call the lorentz + + align:start position:0% +would Now call the lorentz + + + align:start position:0% +would Now call the lorentz +Transformations Lambda eiside had + + align:start position:0% +Transformations Lambda eiside had + + + align:start position:0% +Transformations Lambda eiside had +separately rederived those in a later + + align:start position:0% +separately rederived those in a later + + + align:start position:0% +separately rederived those in a later +part of the paper that I didn't decide + + align:start position:0% +part of the paper that I didn't decide + + + align:start position:0% +part of the paper that I didn't decide +for our class but it's in Hisense paper + + align:start position:0% +for our class but it's in Hisense paper + + + align:start position:0% +for our class but it's in Hisense paper +too + + align:start position:0% +too + + + align:start position:0% +too +these are the Transformations that would + + align:start position:0% +these are the Transformations that would + + + align:start position:0% +these are the Transformations that would +leave the original wave equation + + align:start position:0% +leave the original wave equation + + + align:start position:0% +leave the original wave equation +invariant so then they could use these + + align:start position:0% +invariant so then they could use these + + + align:start position:0% +invariant so then they could use these +inversion these sort of mapping + + align:start position:0% +inversion these sort of mapping + + + align:start position:0% +inversion these sort of mapping +techniques the kind of characteristic + + align:start position:0% +techniques the kind of characteristic + + + align:start position:0% +techniques the kind of characteristic +Wrangler techniques to map into new + + align:start position:0% +Wrangler techniques to map into new + + + align:start position:0% +Wrangler techniques to map into new +dynamical solutions that could vary in + + align:start position:0% +dynamical solutions that could vary in + + + align:start position:0% +dynamical solutions that could vary in +time and not just space keeping in mind + + align:start position:0% +time and not just space keeping in mind + + + align:start position:0% +time and not just space keeping in mind +that now the time coordinate as well as + + align:start position:0% +that now the time coordinate as well as + + + align:start position:0% +that now the time coordinate as well as +the spatial coordinates might need to be + + align:start position:0% +the spatial coordinates might need to be + + + align:start position:0% +the spatial coordinates might need to be +shifted thanks to this lorentz + + align:start position:0% +shifted thanks to this lorentz + + + align:start position:0% +shifted thanks to this lorentz +transformation so they wanted to use + + align:start position:0% +transformation so they wanted to use + + + align:start position:0% +transformation so they wanted to use +Einstein's paper to find the most + + align:start position:0% +Einstein's paper to find the most + + + align:start position:0% +Einstein's paper to find the most +General class of Transformations Lambda + + align:start position:0% +General class of Transformations Lambda + + + align:start position:0% +General class of Transformations Lambda +that would leave this little this harder + + align:start position:0% +that would leave this little this harder + + + align:start position:0% +that would leave this little this harder +problem invariant to do for + + align:start position:0% +problem invariant to do for + + + align:start position:0% +problem invariant to do for +electrodynamics what they had already + + align:start position:0% +electrodynamics what they had already + + + align:start position:0% +electrodynamics what they had already +learned with their uh with their coaches + + align:start position:0% +learned with their uh with their coaches + + + align:start position:0% +learned with their uh with their coaches +to do for electrostatics that's what + + align:start position:0% +to do for electrostatics that's what + + + align:start position:0% +to do for electrostatics that's what +relativity was all about for these folks + + align:start position:0% +relativity was all about for these folks + + + align:start position:0% +relativity was all about for these folks +they were reading Einstein's work very + + align:start position:0% +they were reading Einstein's work very + + + align:start position:0% +they were reading Einstein's work very +carefully they were doing extremely + + align:start position:0% +carefully they were doing extremely + + + align:start position:0% +carefully they were doing extremely +productive hard original work they just + + align:start position:0% +productive hard original work they just + + + align:start position:0% +productive hard original work they just +were doing things that Einstein didn't + + align:start position:0% +were doing things that Einstein didn't + + + align:start position:0% +were doing things that Einstein didn't +notice or care or think was important + + align:start position:0% +notice or care or think was important + + + align:start position:0% +notice or care or think was important +or that minkowski did so they weren't + + align:start position:0% +or that minkowski did so they weren't + + + align:start position:0% +or that minkowski did so they weren't +trying to understand the ether per se + + align:start position:0% +trying to understand the ether per se + + + align:start position:0% +trying to understand the ether per se +again they weren't trying to understand + + align:start position:0% +again they weren't trying to understand + + + align:start position:0% +again they weren't trying to understand +mocking positivism they weren't even + + align:start position:0% +mocking positivism they weren't even + + + align:start position:0% +mocking positivism they weren't even +really that concerned about minkowski's + + align:start position:0% +really that concerned about minkowski's + + + align:start position:0% +really that concerned about minkowski's +space-time for them it's about kind of + + align:start position:0% +space-time for them it's about kind of + + + align:start position:0% +space-time for them it's about kind of +wranglerist manipulations uh of mapping + + align:start position:0% +wranglerist manipulations uh of mapping + + + align:start position:0% +wranglerist manipulations uh of mapping +complicated problems into simpler ones + + align:start position:0% +complicated problems into simpler ones + + + align:start position:0% +complicated problems into simpler ones +and Einstein's paper to them gave them + + align:start position:0% +and Einstein's paper to them gave them + + + align:start position:0% +and Einstein's paper to them gave them +additional tools with which to do their + + align:start position:0% +additional tools with which to do their + + + align:start position:0% +additional tools with which to do their +problem so they weren't ignoring + + align:start position:0% +problem so they weren't ignoring + + + align:start position:0% +problem so they weren't ignoring +Einstein's work but they also weren't + + align:start position:0% +Einstein's work but they also weren't + + + align:start position:0% +Einstein's work but they also weren't +kind of card carrying einsteinians so + + align:start position:0% +kind of card carrying einsteinians so + + + align:start position:0% +kind of card carrying einsteinians so +that's what I want to go through just to + + align:start position:0% +that's what I want to go through just to + + + align:start position:0% +that's what I want to go through just to +make sure the real historical point of + + align:start position:0% +make sure the real historical point of + + + align:start position:0% +make sure the real historical point of +Andy's paper would be clear it gets + + align:start position:0% +Andy's paper would be clear it gets + + + align:start position:0% +Andy's paper would be clear it gets +pretty complicated the details of these + + align:start position:0% +pretty complicated the details of these + + + align:start position:0% +pretty complicated the details of these +inversions all that I'd be glad to chat + + align:start position:0% +inversions all that I'd be glad to chat + + + align:start position:0% +inversions all that I'd be glad to chat +more about that but the main point the + + align:start position:0% +more about that but the main point the + + + align:start position:0% +more about that but the main point the +main lesson for us is really that + + align:start position:0% +main lesson for us is really that + + + align:start position:0% +main lesson for us is really that +they're also doing real work with + + align:start position:0% +they're also doing real work with + + + align:start position:0% +they're also doing real work with +Einstein's paper just different work + + align:start position:0% +Einstein's paper just different work + + + align:start position:0% +Einstein's paper just different work +than Einstein so let me wrap up for + + align:start position:0% +than Einstein so let me wrap up for + + + align:start position:0% +than Einstein so let me wrap up for +today + + align:start position:0% +today + + + align:start position:0% +today +researchers didn't just read Einstein's + + align:start position:0% +researchers didn't just read Einstein's + + + align:start position:0% +researchers didn't just read Einstein's +paper and sort of become convinced they + + align:start position:0% +paper and sort of become convinced they + + + align:start position:0% +paper and sort of become convinced they +didn't become like a converted + + align:start position:0% +didn't become like a converted + + + align:start position:0% +didn't become like a converted +Einstein's for a long long time most + + align:start position:0% +Einstein's for a long long time most + + + align:start position:0% +Einstein's for a long long time most +people ignored the paper altogether uh + + align:start position:0% +people ignored the paper altogether uh + + + align:start position:0% +people ignored the paper altogether uh +those few who paid attention often + + align:start position:0% +those few who paid attention often + + + align:start position:0% +those few who paid attention often +thought it was just a kind of minor + + align:start position:0% +thought it was just a kind of minor + + + align:start position:0% +thought it was just a kind of minor +elaboration of previous work the few who + + align:start position:0% +elaboration of previous work the few who + + + align:start position:0% +elaboration of previous work the few who +really did pay attention to it much more + + align:start position:0% +really did pay attention to it much more + + + align:start position:0% +really did pay attention to it much more +squarely did so from within their own + + align:start position:0% +squarely did so from within their own + + + align:start position:0% +squarely did so from within their own +context we could even kind of jokingly + + align:start position:0% +context we could even kind of jokingly + + + align:start position:0% +context we could even kind of jokingly +say within their own frames of reference + + align:start position:0% +say within their own frames of reference + + + align:start position:0% +say within their own frames of reference +much like you know Einstein's favorite + + align:start position:0% +much like you know Einstein's favorite + + + align:start position:0% +much like you know Einstein's favorite +example of the observers on the platform + + align:start position:0% +example of the observers on the platform + + + align:start position:0% +example of the observers on the platform +are on the train they do different stuff + + align:start position:0% +are on the train they do different stuff + + + align:start position:0% +are on the train they do different stuff +with it different parts of the paper are + + align:start position:0% +with it different parts of the paper are + + + align:start position:0% +with it different parts of the paper are +relevant to them enough value they're + + align:start position:0% +relevant to them enough value they're + + + align:start position:0% +relevant to them enough value they're +not misunderstanding Einstein's work + + align:start position:0% +not misunderstanding Einstein's work + + + align:start position:0% +not misunderstanding Einstein's work +they're like utterly understanding + + align:start position:0% +they're like utterly understanding + + + align:start position:0% +they're like utterly understanding +they're doing real stuff with it which + + align:start position:0% +they're doing real stuff with it which + + + align:start position:0% +they're doing real stuff with it which +is not what Einstein had first intended + + align:start position:0% + + + + align:start position:0% + +in terms of a certain kind of + + align:start position:0% +in terms of a certain kind of + + + align:start position:0% +in terms of a certain kind of +geometrical uh vision of the Cambridge + + align:start position:0% +geometrical uh vision of the Cambridge + + + align:start position:0% +geometrical uh vision of the Cambridge +gang Cunningham Bateman and some of + + align:start position:0% +gang Cunningham Bateman and some of + + + align:start position:0% +gang Cunningham Bateman and some of +their immediate circles they do other + + align:start position:0% +their immediate circles they do other + + + align:start position:0% +their immediate circles they do other +kinds of geometrical things with it + + align:start position:0% +kinds of geometrical things with it + + + align:start position:0% +kinds of geometrical things with it +because they have other concerns more + + align:start position:0% +because they have other concerns more + + + align:start position:0% +because they have other concerns more +related to the properties uh and and + + align:start position:0% +related to the properties uh and and + + + align:start position:0% +related to the properties uh and and +transformation properties of + + align:start position:0% +transformation properties of + + + align:start position:0% +transformation properties of +differential equations + + align:start position:0% +differential equations + + + align:start position:0% +differential equations +the point is none of these readers seem + + align:start position:0% +the point is none of these readers seem + + + align:start position:0% +the point is none of these readers seem +to care much about what was most + + align:start position:0% +to care much about what was most + + + align:start position:0% +to care much about what was most +important to Einstein as far as + + align:start position:0% +important to Einstein as far as + + + align:start position:0% +important to Einstein as far as +Einstein's concerned none of them were + + align:start position:0% +Einstein's concerned none of them were + + + align:start position:0% +Einstein's concerned none of them were +getting the point of his article even + + align:start position:0% +getting the point of his article even + + + align:start position:0% +getting the point of his article even +though these were among the people who + + align:start position:0% +though these were among the people who + + + align:start position:0% +though these were among the people who +paid any attention at all Einstein had + + align:start position:0% +paid any attention at all Einstein had + + + align:start position:0% +paid any attention at all Einstein had +argued in those opening paragraphs but + + align:start position:0% +argued in those opening paragraphs but + + + align:start position:0% +argued in those opening paragraphs but +the ether was merely Superfluous who + + align:start position:0% +the ether was merely Superfluous who + + + align:start position:0% +the ether was merely Superfluous who +cared that's you know they didn't that + + align:start position:0% +cared that's you know they didn't that + + + align:start position:0% +cared that's you know they didn't that +wasn't the part that landed them + + align:start position:0% +wasn't the part that landed them + + + align:start position:0% +wasn't the part that landed them +moreover Einstein had insisted that we + + align:start position:0% +moreover Einstein had insisted that we + + + align:start position:0% +moreover Einstein had insisted that we +start with kinematics instead of + + align:start position:0% +start with kinematics instead of + + + align:start position:0% +start with kinematics instead of +Dynamics forget that that sort of didn't + + align:start position:0% +Dynamics forget that that sort of didn't + + + align:start position:0% +Dynamics forget that that sort of didn't +wash that didn't register instead as + + align:start position:0% +wash that didn't register instead as + + + align:start position:0% +wash that didn't register instead as +we've seen before and we'll see again + + align:start position:0% +we've seen before and we'll see again + + + align:start position:0% +we've seen before and we'll see again +even the exact same equations could + + align:start position:0% +even the exact same equations could + + + align:start position:0% +even the exact same equations could +Inspire quite different interpretations + + align:start position:0% +Inspire quite different interpretations + + + align:start position:0% +Inspire quite different interpretations +for different meanings so I'll stop + + align:start position:0% +for different meanings so I'll stop + + + align:start position:0% +for different meanings so I'll stop +there + + align:start position:0% +there + + + align:start position:0% +there +any other questions on that last part + + align:start position:0% +any other questions on that last part + + + align:start position:0% +any other questions on that last part +about the Cambridge gang + + align:start position:0% +about the Cambridge gang + + + align:start position:0% +about the Cambridge gang +and again if the particulars of + + align:start position:0% +and again if the particulars of + + + align:start position:0% +and again if the particulars of +conformal Transformations or inversion + + align:start position:0% +conformal Transformations or inversion + + + align:start position:0% +conformal Transformations or inversion +uh went by too quickly or Andy's paper + + align:start position:0% +uh went by too quickly or Andy's paper + + + align:start position:0% +uh went by too quickly or Andy's paper +was confusing please don't worry I'd be + + align:start position:0% +was confusing please don't worry I'd be + + + align:start position:0% +was confusing please don't worry I'd be +glad to chat more if it's of interest + + align:start position:0% +glad to chat more if it's of interest + + + align:start position:0% +glad to chat more if it's of interest +for you but but the historical point is + + align:start position:0% +for you but but the historical point is + + + align:start position:0% +for you but but the historical point is +just to say they were they were doing + + align:start position:0% +just to say they were they were doing + + + align:start position:0% +just to say they were they were doing +real work it's still in our textbooks it + + align:start position:0% +real work it's still in our textbooks it + + + align:start position:0% +real work it's still in our textbooks it +was valuable work it was just different + + align:start position:0% +was valuable work it was just different + + + align:start position:0% +was valuable work it was just different +work than than Einstein's or minkowski's + + align:start position:0% +work than than Einstein's or minkowski's + + + align:start position:0% +work than than Einstein's or minkowski's +or you know lorenzes and so on that's + + align:start position:0% +or you know lorenzes and so on that's + + + align:start position:0% +or you know lorenzes and so on that's +that's really the point I think we can + + align:start position:0% +that's really the point I think we can + + + align:start position:0% +that's really the point I think we can +hold on to in this class + + align:start position:0% + + + + align:start position:0% + +any other questions on that + + align:start position:0% + + + + align:start position:0% + +anyone want to volunteer to do more uh + + align:start position:0% +anyone want to volunteer to do more uh + + + align:start position:0% +anyone want to volunteer to do more uh +inversion problems for conducting + + align:start position:0% +inversion problems for conducting + + + align:start position:0% +inversion problems for conducting +spheres and I hate that stuff that's + + align:start position:0% +spheres and I hate that stuff that's + + + align:start position:0% +spheres and I hate that stuff that's +done yeah Julia says no I'm with Julie + + align:start position:0% +done yeah Julia says no I'm with Julie + + + align:start position:0% +done yeah Julia says no I'm with Julie +on this that stuff makes me that really + + align:start position:0% +on this that stuff makes me that really + + + align:start position:0% +on this that stuff makes me that really +makes my head hurt + + align:start position:0% + + + + align:start position:0% + +I didn't want to do that for five hours + + align:start position:0% +I didn't want to do that for five hours + + + align:start position:0% +I didn't want to do that for five hours +before lunch like a good Wrangler that's + + align:start position:0% +before lunch like a good Wrangler that's + + + align:start position:0% +before lunch like a good Wrangler that's +another question your math homework + + align:start position:0% +another question your math homework + + + align:start position:0% +another question your math homework +before lunchtime + + align:start position:0% +before lunchtime + + + align:start position:0% +before lunchtime +okay if there's no more questions uh for + + align:start position:0% +okay if there's no more questions uh for + + + align:start position:0% +okay if there's no more questions uh for +now then I'll I'll pause there uh we'll + + align:start position:0% +now then I'll I'll pause there uh we'll + + + align:start position:0% +now then I'll I'll pause there uh we'll +pick it up uh early next week and we'll + + align:start position:0% +pick it up uh early next week and we'll + + + align:start position:0% +pick it up uh early next week and we'll +and we'll get into many of the questions + + align:start position:0% +and we'll get into many of the questions + + + align:start position:0% +and we'll get into many of the questions +that were raised even um for today what + + align:start position:0% +that were raised even um for today what + + + align:start position:0% +that were raised even um for today what +does Einstein himself do with all this + + align:start position:0% +does Einstein himself do with all this + + + align:start position:0% +does Einstein himself do with all this +work in what in his march to work what + + align:start position:0% +work in what in his march to work what + + + align:start position:0% +work in what in his march to work what +we would eventually call the general + + align:start position:0% +we would eventually call the general + + + align:start position:0% +we would eventually call the general +theory of relativity so we'll come to + + align:start position:0% +theory of relativity so we'll come to + + + align:start position:0% +theory of relativity so we'll come to +that that will occupy us then for for + + align:start position:0% +that that will occupy us then for for + + + align:start position:0% +that that will occupy us then for for +our next class \ No newline at end of file diff --git a/ZSv_gYLBi8E.txt b/ZSv_gYLBi8E.txt new file mode 100644 index 0000000000000000000000000000000000000000..3a6834a5dfe6b3fd77d3eaa04ea88a42b4719190 --- /dev/null +++ b/ZSv_gYLBi8E.txt @@ -0,0 +1,9427 @@ +align:start position:0% + +we're gonna + + align:start position:0% +we're gonna + + + align:start position:0% +we're gonna +pick up where we left off on monday + + align:start position:0% +pick up where we left off on monday + + + align:start position:0% +pick up where we left off on monday +and where we left off was we were + + align:start position:0% +and where we left off was we were + + + align:start position:0% +and where we left off was we were +dissolving stuff we talked about how + + align:start position:0% +dissolving stuff we talked about how + + + align:start position:0% +dissolving stuff we talked about how +things + + align:start position:0% +things + + + align:start position:0% +things +dissolve why does something dissolve + + align:start position:0% +dissolve why does something dissolve + + + align:start position:0% +dissolve why does something dissolve +maybe in this solvent versus that and + + align:start position:0% +maybe in this solvent versus that and + + + align:start position:0% +maybe in this solvent versus that and +how does it dissolve and what makes them + + align:start position:0% +how does it dissolve and what makes them + + + align:start position:0% +how does it dissolve and what makes them +and then we say well what if we had + + align:start position:0% +and then we say well what if we had + + + align:start position:0% +and then we say well what if we had +something and we wanted it to dissolve + + align:start position:0% +something and we wanted it to dissolve + + + align:start position:0% +something and we wanted it to dissolve +all the way until it couldn't dissolve + + align:start position:0% +all the way until it couldn't dissolve + + + align:start position:0% +all the way until it couldn't dissolve +anymore well that's called + + align:start position:0% +anymore well that's called + + + align:start position:0% +anymore well that's called +saturation right + + align:start position:0% +saturation right + + + align:start position:0% +saturation right +and and we talked about that we talked + + align:start position:0% +and and we talked about that we talked + + + align:start position:0% +and and we talked about that we talked +about how if you had a general reaction + + align:start position:0% +about how if you had a general reaction + + + align:start position:0% +about how if you had a general reaction +you know maybe we had something like + + align:start position:0% +you know maybe we had something like + + + align:start position:0% +you know maybe we had something like +this right a + + align:start position:0% +this right a + + + align:start position:0% +this right a +a plus b b + + align:start position:0% +a plus b b + + + align:start position:0% +a plus b b +goes to and comes back from + + align:start position:0% +goes to and comes back from + + + align:start position:0% +goes to and comes back from +c c plus dd then + + align:start position:0% +c c plus dd then + + + align:start position:0% +c c plus dd then +this reaction can happen in both ways + + align:start position:0% +this reaction can happen in both ways + + + align:start position:0% +this reaction can happen in both ways +right and so the general + + align:start position:0% +right and so the general + + + align:start position:0% +right and so the general +concept that we called a reaction + + align:start position:0% +concept that we called a reaction + + + align:start position:0% +concept that we called a reaction +quotient + + align:start position:0% +quotient + + + align:start position:0% +quotient +reaction q + + align:start position:0% +reaction q + + + align:start position:0% +reaction q +is equal to remember it's equal to the + + align:start position:0% +is equal to remember it's equal to the + + + align:start position:0% +is equal to remember it's equal to the +concentrations + + align:start position:0% +concentrations + + + align:start position:0% +concentrations +raised to those stoichiometric + + align:start position:0% +raised to those stoichiometric + + + align:start position:0% +raised to those stoichiometric +coefficients + + align:start position:0% +coefficients + + + align:start position:0% +coefficients +and it's the products over + + align:start position:0% +and it's the products over + + + align:start position:0% +and it's the products over +the reactants okay so that's what we now + + align:start position:0% +the reactants okay so that's what we now + + + align:start position:0% +the reactants okay so that's what we now +then we + + align:start position:0% +then we + + + align:start position:0% +then we +we say well okay that's just okay that's + + align:start position:0% +we say well okay that's just okay that's + + + align:start position:0% +we say well okay that's just okay that's +a thing that that has to do with sort of + + align:start position:0% +a thing that that has to do with sort of + + + align:start position:0% +a thing that that has to do with sort of +maybe + + align:start position:0% +maybe + + + align:start position:0% +maybe +you know where's that reaction going + + align:start position:0% +you know where's that reaction going + + + align:start position:0% +you know where's that reaction going +what's dominating + + align:start position:0% +what's dominating + + + align:start position:0% +what's dominating +uh it and these came remember these are + + align:start position:0% +uh it and these came remember these are + + + align:start position:0% +uh it and these came remember these are +the stoichiometric coefficients and + + align:start position:0% +the stoichiometric coefficients and + + + align:start position:0% +the stoichiometric coefficients and +they're related to + + align:start position:0% +they're related to + + + align:start position:0% +they're related to +literally like the probability that that + + align:start position:0% +literally like the probability that that + + + align:start position:0% +literally like the probability that that +reaction can happen + + align:start position:0% +reaction can happen + + + align:start position:0% +reaction can happen +okay um and so if you want an intuitive + + align:start position:0% +okay um and so if you want an intuitive + + + align:start position:0% +okay um and so if you want an intuitive +reason for the exponents you can think + + align:start position:0% +reason for the exponents you can think + + + align:start position:0% +reason for the exponents you can think +about this as well if these all have to + + align:start position:0% +about this as well if these all have to + + + align:start position:0% +about this as well if these all have to +get close enough in a given volume + + align:start position:0% +get close enough in a given volume + + + align:start position:0% +get close enough in a given volume +to react then that's where those + + align:start position:0% +to react then that's where those + + + align:start position:0% +to react then that's where those +exponents come from + + align:start position:0% +exponents come from + + + align:start position:0% +exponents come from +but they don't but unlike the rate law + + align:start position:0% +but they don't but unlike the rate law + + + align:start position:0% +but they don't but unlike the rate law +when i said this money i'm saying it + + align:start position:0% +when i said this money i'm saying it + + + align:start position:0% +when i said this money i'm saying it +again say they are not things that are + + align:start position:0% +again say they are not things that are + + + align:start position:0% +again say they are not things that are +experimentally measured instead they + + align:start position:0% +experimentally measured instead they + + + align:start position:0% +experimentally measured instead they +just come + + align:start position:0% +just come + + + align:start position:0% +just come +from the reaction itself okay now uh so + + align:start position:0% +from the reaction itself okay now uh so + + + align:start position:0% +from the reaction itself okay now uh so +we're just getting back into the right + + align:start position:0% +we're just getting back into the right + + + align:start position:0% +we're just getting back into the right +mood here but then we said well but look + + align:start position:0% +mood here but then we said well but look + + + align:start position:0% +mood here but then we said well but look +okay this thing is reacting it's going + + align:start position:0% +okay this thing is reacting it's going + + + align:start position:0% +okay this thing is reacting it's going +back and forth + + align:start position:0% +back and forth + + + align:start position:0% +back and forth +whatever but what about once it reaches + + align:start position:0% +whatever but what about once it reaches + + + align:start position:0% +whatever but what about once it reaches +equilibrium right equilibrium and and + + align:start position:0% +equilibrium right equilibrium and and + + + align:start position:0% +equilibrium right equilibrium and and +when it reaches equilibrium + + align:start position:0% +when it reaches equilibrium + + + align:start position:0% +when it reaches equilibrium +it's the same thing but we call it k + + align:start position:0% +it's the same thing but we call it k + + + align:start position:0% +it's the same thing but we call it k +eq in + + align:start position:0% +eq in + + + align:start position:0% +eq in +equilibrium equal m + + align:start position:0% +equilibrium equal m + + + align:start position:0% +equilibrium equal m +equilibrium right so so that reaction + + align:start position:0% +equilibrium right so so that reaction + + + align:start position:0% +equilibrium right so so that reaction +quotient + + align:start position:0% +quotient + + + align:start position:0% +quotient +has a very specific value a constant + + align:start position:0% +has a very specific value a constant + + + align:start position:0% +has a very specific value a constant +a constant once this way + + align:start position:0% +a constant once this way + + + align:start position:0% +a constant once this way +is happening in the same amount as that + + align:start position:0% +is happening in the same amount as that + + + align:start position:0% +is happening in the same amount as that +way + + align:start position:0% +way + + + align:start position:0% +way +right that's the saturation point + + align:start position:0% +right that's the saturation point + + + align:start position:0% +right that's the saturation point +well if you're dissolving something + + align:start position:0% +well if you're dissolving something + + + align:start position:0% +well if you're dissolving something +that's the saturation point + + align:start position:0% +that's the saturation point + + + align:start position:0% +that's the saturation point +okay so it's where it's where the + + align:start position:0% +okay so it's where it's where the + + + align:start position:0% +okay so it's where it's where the +precipitation remember we wrote this as + + align:start position:0% +precipitation remember we wrote this as + + + align:start position:0% +precipitation remember we wrote this as +dissolution and precipitation when we + + align:start position:0% +dissolution and precipitation when we + + + align:start position:0% +dissolution and precipitation when we +were putting stuff in solution and + + align:start position:0% +were putting stuff in solution and + + + align:start position:0% +were putting stuff in solution and +that's kind of where we got to + + align:start position:0% +that's kind of where we got to + + + align:start position:0% +that's kind of where we got to +we went a little bit further and we had + + align:start position:0% +we went a little bit further and we had + + + align:start position:0% +we went a little bit further and we had +a specific example and that's where i + + align:start position:0% +a specific example and that's where i + + + align:start position:0% +a specific example and that's where i +want to start today + + align:start position:0% +want to start today + + + align:start position:0% +want to start today +and that's silver chloride okay so here + + align:start position:0% +and that's silver chloride okay so here + + + align:start position:0% +and that's silver chloride okay so here +we go so we have + + align:start position:0% +we go so we have + + + align:start position:0% +we go so we have +silver chloride and if i write this all + + align:start position:0% +silver chloride and if i write this all + + + align:start position:0% +silver chloride and if i write this all +out for silver chloride i've got + + align:start position:0% +out for silver chloride i've got + + + align:start position:0% +out for silver chloride i've got +a g cl and i've got a little pinch of it + + align:start position:0% +a g cl and i've got a little pinch of it + + + align:start position:0% +a g cl and i've got a little pinch of it +you know like a little speck of silver + + align:start position:0% +you know like a little speck of silver + + + align:start position:0% +you know like a little speck of silver +chloride i'm putting it into + + align:start position:0% +chloride i'm putting it into + + + align:start position:0% +chloride i'm putting it into +a beaker so it starts out as a solid and + + align:start position:0% +a beaker so it starts out as a solid and + + + align:start position:0% +a beaker so it starts out as a solid and +i add some water to it + + align:start position:0% +i add some water to it + + + align:start position:0% +i add some water to it +and the water is l because it's + + align:start position:0% +and the water is l because it's + + + align:start position:0% +and the water is l because it's +everywhere it's the liquid it's the + + align:start position:0% +everywhere it's the liquid it's the + + + align:start position:0% +everywhere it's the liquid it's the +solvent + + align:start position:0% +solvent + + + align:start position:0% +solvent +okay it's the liquid that i'm dissolving + + align:start position:0% +okay it's the liquid that i'm dissolving + + + align:start position:0% +okay it's the liquid that i'm dissolving +it in and we say well okay + + align:start position:0% +it in and we say well okay + + + align:start position:0% +it in and we say well okay +that's going to go like this so that + + align:start position:0% +that's going to go like this so that + + + align:start position:0% +that's going to go like this so that +reaction it's going to give us + + align:start position:0% +reaction it's going to give us + + + align:start position:0% +reaction it's going to give us +silver ions remember salts we did salts + + align:start position:0% +silver ions remember salts we did salts + + + align:start position:0% +silver ions remember salts we did salts +and chlorine ions and + + align:start position:0% +and chlorine ions and + + + align:start position:0% +and chlorine ions and +back to some more water + + align:start position:0% +back to some more water + + + align:start position:0% +back to some more water +okay that's h2o now the aq means aqueous + + align:start position:0% +okay that's h2o now the aq means aqueous + + + align:start position:0% +okay that's h2o now the aq means aqueous +these are now + + align:start position:0% +these are now + + + align:start position:0% +these are now +because it's a salt right these are now + + align:start position:0% +because it's a salt right these are now + + + align:start position:0% +because it's a salt right these are now +dissolved ions because it's a salt so we + + align:start position:0% +dissolved ions because it's a salt so we + + + align:start position:0% +dissolved ions because it's a salt so we +write them like that + + align:start position:0% +write them like that + + + align:start position:0% +write them like that +and we know we got water everywhere and + + align:start position:0% +and we know we got water everywhere and + + + align:start position:0% +and we know we got water everywhere and +so oftentimes we leave the water out + + align:start position:0% +so oftentimes we leave the water out + + + align:start position:0% +so oftentimes we leave the water out +oftentimes we don't really write the + + align:start position:0% +oftentimes we don't really write the + + + align:start position:0% +oftentimes we don't really write the +water because it's on both sides + + align:start position:0% +water because it's on both sides + + + align:start position:0% +water because it's on both sides +and anyway we don't the water the water + + align:start position:0% +and anyway we don't the water the water + + + align:start position:0% +and anyway we don't the water the water +is just surrounding stuff it's not + + align:start position:0% +is just surrounding stuff it's not + + + align:start position:0% +is just surrounding stuff it's not +necessarily been consumed + + align:start position:0% +necessarily been consumed + + + align:start position:0% +necessarily been consumed +the concentration of the water isn't + + align:start position:0% +the concentration of the water isn't + + + align:start position:0% +the concentration of the water isn't +changing + + align:start position:0% +changing + + + align:start position:0% +changing +the water is the water in the liquid + + align:start position:0% +the water is the water in the liquid + + + align:start position:0% +the water is the water in the liquid +phase + + align:start position:0% +phase + + + align:start position:0% +phase +well okay then we went even further you + + align:start position:0% +well okay then we went even further you + + + align:start position:0% +well okay then we went even further you +said well if you write a keq for this + + align:start position:0% +said well if you write a keq for this + + + align:start position:0% +said well if you write a keq for this +then it would uh i would look like + + align:start position:0% +then it would uh i would look like + + + align:start position:0% +then it would uh i would look like +something like okay it's the + + align:start position:0% +something like okay it's the + + + align:start position:0% +something like okay it's the +concentration of silver plus + + align:start position:0% +concentration of silver plus + + + align:start position:0% +concentration of silver plus +in solution times the concentration of + + align:start position:0% +in solution times the concentration of + + + align:start position:0% +in solution times the concentration of +chlorine + + align:start position:0% +chlorine + + + align:start position:0% +chlorine +minus in solution and that would be + + align:start position:0% +minus in solution and that would be + + + align:start position:0% +minus in solution and that would be +divided by + + align:start position:0% +divided by + + + align:start position:0% +divided by +the concentration of silver chloride + + align:start position:0% +the concentration of silver chloride + + + align:start position:0% +the concentration of silver chloride +as a solid and then we said + + align:start position:0% +as a solid and then we said + + + align:start position:0% +as a solid and then we said +but hold on no but hold on + + align:start position:0% +but hold on no but hold on + + + align:start position:0% +but hold on no but hold on +in the solid phase the concentration + + align:start position:0% +in the solid phase the concentration + + + align:start position:0% +in the solid phase the concentration +isn't changing + + align:start position:0% +isn't changing + + + align:start position:0% +isn't changing +right as a solid silver chloride the + + align:start position:0% +right as a solid silver chloride the + + + align:start position:0% +right as a solid silver chloride the +concentration of silver chloride is + + align:start position:0% +concentration of silver chloride is + + + align:start position:0% +concentration of silver chloride is +silver chloride it's a constant + + align:start position:0% +silver chloride it's a constant + + + align:start position:0% +silver chloride it's a constant +and so then we say well okay if this + + align:start position:0% +and so then we say well okay if this + + + align:start position:0% +and so then we say well okay if this +is a constant this is a constant + + align:start position:0% +is a constant this is a constant + + + align:start position:0% +is a constant this is a constant +then we can also absorb it into the + + align:start position:0% +then we can also absorb it into the + + + align:start position:0% +then we can also absorb it into the +equilibrium constant + + align:start position:0% +equilibrium constant + + + align:start position:0% +equilibrium constant +and i somewhat confusingly wrote it as + + align:start position:0% +and i somewhat confusingly wrote it as + + + align:start position:0% +and i somewhat confusingly wrote it as +ksp in both + + align:start position:0% +ksp in both + + + align:start position:0% +ksp in both +this form and the form that + + align:start position:0% +this form and the form that + + + align:start position:0% +this form and the form that +we know and love for ksp which is simply + + align:start position:0% +we know and love for ksp which is simply + + + align:start position:0% +we know and love for ksp which is simply +literally the solubilities of these + + align:start position:0% +literally the solubilities of these + + + align:start position:0% +literally the solubilities of these +times each other right and that is ksp + + align:start position:0% +times each other right and that is ksp + + + align:start position:0% +times each other right and that is ksp +so i wanted just to clarify this + + align:start position:0% +so i wanted just to clarify this + + + align:start position:0% +so i wanted just to clarify this +because the student asked a very good + + align:start position:0% +because the student asked a very good + + + align:start position:0% +because the student asked a very good +question which is + + align:start position:0% +question which is + + + align:start position:0% +question which is +which is which is it now is this in ks + + align:start position:0% +which is which is it now is this in ks + + + align:start position:0% +which is which is it now is this in ks +p or is this in keq well the the the big + + align:start position:0% +p or is this in keq well the the the big + + + align:start position:0% +p or is this in keq well the the the big +full picture for keq + + align:start position:0% +full picture for keq + + + align:start position:0% +full picture for keq +you know you'd write it all in but the + + align:start position:0% +you know you'd write it all in but the + + + align:start position:0% +you know you'd write it all in but the +solubility product + + align:start position:0% +solubility product + + + align:start position:0% +solubility product +is focusing in right on on the the + + align:start position:0% +is focusing in right on on the the + + + align:start position:0% +is focusing in right on on the the +dissolution + + align:start position:0% +dissolution + + + align:start position:0% +dissolution +of these ions and and so you wrap this + + align:start position:0% +of these ions and and so you wrap this + + + align:start position:0% +of these ions and and so you wrap this +into the equilibrium constant because + + align:start position:0% +into the equilibrium constant because + + + align:start position:0% +into the equilibrium constant because +it's another constant so that's the + + align:start position:0% +it's another constant so that's the + + + align:start position:0% +it's another constant so that's the +solubility product and that's where we + + align:start position:0% +solubility product and that's where we + + + align:start position:0% +solubility product and that's where we +got + + align:start position:0% +got + + + align:start position:0% +got +to on monday the solubility product is a + + align:start position:0% +to on monday the solubility product is a + + + align:start position:0% +to on monday the solubility product is a +special equilibrium constant + + align:start position:0% +special equilibrium constant + + + align:start position:0% +special equilibrium constant +where what we're talking about right + + align:start position:0% +where what we're talking about right + + + align:start position:0% +where what we're talking about right +is is you know what what are the + + align:start position:0% +is is you know what what are the + + + align:start position:0% +is is you know what what are the +concentrations when you've reached + + align:start position:0% +concentrations when you've reached + + + align:start position:0% +concentrations when you've reached +saturation of this dissolution + + align:start position:0% +saturation of this dissolution + + + align:start position:0% +saturation of this dissolution +precipitation reaction + + align:start position:0% +precipitation reaction + + + align:start position:0% +precipitation reaction +okay that's the solubility product + + align:start position:0% +okay that's the solubility product + + + align:start position:0% +okay that's the solubility product +that's ksp + + align:start position:0% +that's ksp + + + align:start position:0% +that's ksp +so you wrap this in and you get you get + + align:start position:0% +so you wrap this in and you get you get + + + align:start position:0% +so you wrap this in and you get you get +your ksp + + align:start position:0% +your ksp + + + align:start position:0% +your ksp +uh you can think about it as well maybe + + align:start position:0% +uh you can think about it as well maybe + + + align:start position:0% +uh you can think about it as well maybe +you could have called this some ksp + + align:start position:0% +you could have called this some ksp + + + align:start position:0% +you could have called this some ksp +in you know uh uh pre-ksp and then you + + align:start position:0% +in you know uh uh pre-ksp and then you + + + align:start position:0% +in you know uh uh pre-ksp and then you +wrap this in and then it's still just + + align:start position:0% +wrap this in and then it's still just + + + align:start position:0% +wrap this in and then it's still just +kidding + + align:start position:0% +kidding + + + align:start position:0% +kidding +because it's still just a constant + + align:start position:0% +because it's still just a constant + + + align:start position:0% +because it's still just a constant +representing this reaction okay i just + + align:start position:0% +representing this reaction okay i just + + + align:start position:0% +representing this reaction okay i just +wanted to make this super clear because + + align:start position:0% +wanted to make this super clear because + + + align:start position:0% +wanted to make this super clear because +this + + align:start position:0% +this + + + align:start position:0% +this +part leads to confusion often that this + + align:start position:0% +part leads to confusion often that this + + + align:start position:0% +part leads to confusion often that this +gets left + + align:start position:0% +gets left + + + align:start position:0% +gets left +out because it's constant doesn't change + + align:start position:0% +out because it's constant doesn't change + + + align:start position:0% +out because it's constant doesn't change +okay + + align:start position:0% +okay + + + align:start position:0% +okay +good now we get to that because + + align:start position:0% +good now we get to that because + + + align:start position:0% +good now we get to that because +this is a constant okay so what does + + align:start position:0% +this is a constant okay so what does + + + align:start position:0% +this is a constant okay so what does +that mean + + align:start position:0% +that mean + + + align:start position:0% +that mean +well it means that if i dissolve this + + align:start position:0% +well it means that if i dissolve this + + + align:start position:0% +well it means that if i dissolve this +thing in water + + align:start position:0% +thing in water + + + align:start position:0% +thing in water +right then then the equilibrium the + + align:start position:0% +right then then the equilibrium the + + + align:start position:0% +right then then the equilibrium the +equilibrium + + align:start position:0% +equilibrium + + + align:start position:0% +equilibrium +is is a fixed number this equilibrium + + align:start position:0% +is is a fixed number this equilibrium + + + align:start position:0% +is is a fixed number this equilibrium +product is fixed + + align:start position:0% +product is fixed + + + align:start position:0% +product is fixed +and that has a very important meaning + + align:start position:0% +and that has a very important meaning + + + align:start position:0% +and that has a very important meaning +it's the green curve + + align:start position:0% +it's the green curve + + + align:start position:0% +it's the green curve +you see it says equilibrium right and + + align:start position:0% +you see it says equilibrium right and + + + align:start position:0% +you see it says equilibrium right and +and so + + align:start position:0% +and so + + + align:start position:0% +and so +that what that means is that if i you + + align:start position:0% +that what that means is that if i you + + + align:start position:0% +that what that means is that if i you +know if i'm at point b well there i go + + align:start position:0% +know if i'm at point b well there i go + + + align:start position:0% +know if i'm at point b well there i go +i've got my we we said ksp + + align:start position:0% +i've got my we we said ksp + + + align:start position:0% +i've got my we we said ksp +ksp for this one equals + + align:start position:0% +ksp for this one equals + + + align:start position:0% +ksp for this one equals +uh what was it 1.7 + + align:start position:0% +uh what was it 1.7 + + + align:start position:0% +uh what was it 1.7 +times 10 to the minus 10th + + align:start position:0% +times 10 to the minus 10th + + + align:start position:0% +times 10 to the minus 10th +units are coming and so now so that's + + align:start position:0% +units are coming and so now so that's + + + align:start position:0% +units are coming and so now so that's +the ksp + + align:start position:0% +the ksp + + + align:start position:0% +the ksp +for uh for + + align:start position:0% + + + + align:start position:0% + +silver chloride + + align:start position:0% + + + + align:start position:0% + +in h2o oh and you have to say + + align:start position:0% +in h2o oh and you have to say + + + align:start position:0% +in h2o oh and you have to say +at some temperature + + align:start position:0% + + + + align:start position:0% + +it will depend on temperature often you + + align:start position:0% +it will depend on temperature often you + + + align:start position:0% +it will depend on temperature often you +often will just + + align:start position:0% +often will just + + + align:start position:0% +often will just +be at room temperature 25 c for example + + align:start position:0% +be at room temperature 25 c for example + + + align:start position:0% +be at room temperature 25 c for example +so often these get quoted just at room + + align:start position:0% +so often these get quoted just at room + + + align:start position:0% +so often these get quoted just at room +temperature + + align:start position:0% +temperature + + + align:start position:0% +temperature +okay now okay so once i know that then i + + align:start position:0% +okay now okay so once i know that then i + + + align:start position:0% +okay now okay so once i know that then i +know that that's equilibrium no matter + + align:start position:0% +know that that's equilibrium no matter + + + align:start position:0% +know that that's equilibrium no matter +what + + align:start position:0% +what + + + align:start position:0% +what +right and so that means that if like you + + align:start position:0% +right and so that means that if like you + + + align:start position:0% +right and so that means that if like you +know and then we solve this we said well + + align:start position:0% +know and then we solve this we said well + + + align:start position:0% +know and then we solve this we said well +okay if i dissolve silver chloride + + align:start position:0% +okay if i dissolve silver chloride + + + align:start position:0% +okay if i dissolve silver chloride +and i didn't and i had nothing else then + + align:start position:0% +and i didn't and i had nothing else then + + + align:start position:0% +and i didn't and i had nothing else then +you know the ksp would equal + + align:start position:0% +you know the ksp would equal + + + align:start position:0% +you know the ksp would equal +the concentration of silver times the + + align:start position:0% +the concentration of silver times the + + + align:start position:0% +the concentration of silver times the +concentration of chlorine ions + + align:start position:0% +concentration of chlorine ions + + + align:start position:0% +concentration of chlorine ions +and so if we let each one but those are + + align:start position:0% +and so if we let each one but those are + + + align:start position:0% +and so if we let each one but those are +equal and so if we let each one of them + + align:start position:0% +equal and so if we let each one of them + + + align:start position:0% +equal and so if we let each one of them +be x then it's equal to x squared + + align:start position:0% +be x then it's equal to x squared + + + align:start position:0% +be x then it's equal to x squared +and so we know that the concentration of + + align:start position:0% +and so we know that the concentration of + + + align:start position:0% +and so we know that the concentration of +each of them + + align:start position:0% +each of them + + + align:start position:0% +each of them +is 10 to the minus + + align:start position:0% +is 10 to the minus + + + align:start position:0% +is 10 to the minus +let me write it exactly 1.3 times 10 + + align:start position:0% +let me write it exactly 1.3 times 10 + + + align:start position:0% +let me write it exactly 1.3 times 10 +to the minus fifth now it's a + + align:start position:0% +to the minus fifth now it's a + + + align:start position:0% +to the minus fifth now it's a +concentration so you know + + align:start position:0% +concentration so you know + + + align:start position:0% +concentration so you know +that it's got to be capital m moles per + + align:start position:0% +that it's got to be capital m moles per + + + align:start position:0% +that it's got to be capital m moles per +liter + + align:start position:0% +liter + + + align:start position:0% +liter +and and since that's the case since + + align:start position:0% +and and since that's the case since + + + align:start position:0% +and and since that's the case since +that's where you know + + align:start position:0% +that's where you know + + + align:start position:0% +that's where you know +what it is then now you can back up + + align:start position:0% +what it is then now you can back up + + + align:start position:0% +what it is then now you can back up +because this is the concentration + + align:start position:0% +because this is the concentration + + + align:start position:0% +because this is the concentration +of ag ions and it's also the + + align:start position:0% +of ag ions and it's also the + + + align:start position:0% +of ag ions and it's also the +concentration of chlorine ions + + align:start position:0% +concentration of chlorine ions + + + align:start position:0% +concentration of chlorine ions +then you know that the the units of ksp + + align:start position:0% +then you know that the the units of ksp + + + align:start position:0% +then you know that the the units of ksp +must be m squared right + + align:start position:0% + + + + align:start position:0% + +units in this case + + align:start position:0% + + + + align:start position:0% + +moles per liter square must be because + + align:start position:0% +moles per liter square must be because + + + align:start position:0% +moles per liter square must be because +otherwise the concentration isn't right + + align:start position:0% +otherwise the concentration isn't right + + + align:start position:0% +otherwise the concentration isn't right +the units are concentration okay now now + + align:start position:0% +the units are concentration okay now now + + + align:start position:0% +the units are concentration okay now now +okay now we're going to play with this + + align:start position:0% +okay now we're going to play with this + + + align:start position:0% +okay now we're going to play with this +so okay so i'm at b i'm at point b + + align:start position:0% +so okay so i'm at b i'm at point b + + + align:start position:0% +so okay so i'm at b i'm at point b +you see that there i am and i've got my + + align:start position:0% +you see that there i am and i've got my + + + align:start position:0% +you see that there i am and i've got my +concentration of chlorine + + align:start position:0% +concentration of chlorine + + + align:start position:0% +concentration of chlorine +concentration of silver and i'm here and + + align:start position:0% +concentration of silver and i'm here and + + + align:start position:0% +concentration of silver and i'm here and +and so that's 1.3 times 10 to minus 5th + + align:start position:0% +and so that's 1.3 times 10 to minus 5th + + + align:start position:0% +and so that's 1.3 times 10 to minus 5th +okay now if i if i didn't have as much + + align:start position:0% +okay now if i if i didn't have as much + + + align:start position:0% +okay now if i if i didn't have as much +if i didn't if i weren't at the + + align:start position:0% +if i didn't if i weren't at the + + + align:start position:0% +if i didn't if i weren't at the +saturation point + + align:start position:0% +saturation point + + + align:start position:0% +saturation point +right then i could add more i'd be here + + align:start position:0% +right then i could add more i'd be here + + + align:start position:0% +right then i could add more i'd be here +and i could add more solid silver + + align:start position:0% +and i could add more solid silver + + + align:start position:0% +and i could add more solid silver +chloride and i didn't you know and + + align:start position:0% +chloride and i didn't you know and + + + align:start position:0% +chloride and i didn't you know and +eventually i'd reach this uh + + align:start position:0% +eventually i'd reach this uh + + + align:start position:0% +eventually i'd reach this uh +i'd reach this this equilibrium but if i + + align:start position:0% +i'd reach this this equilibrium but if i + + + align:start position:0% +i'd reach this this equilibrium but if i +added more than that + + align:start position:0% +added more than that + + + align:start position:0% +added more than that +so now i'm adding way more than i can + + align:start position:0% +so now i'm adding way more than i can + + + align:start position:0% +so now i'm adding way more than i can +then it's just going to be a solid + + align:start position:0% +then it's just going to be a solid + + + align:start position:0% +then it's just going to be a solid +and that's kind of boring so now i'm up + + align:start position:0% +and that's kind of boring so now i'm up + + + align:start position:0% +and that's kind of boring so now i'm up +here + + align:start position:0% +here + + + align:start position:0% +here +but maybe i had ions in so these are the + + align:start position:0% +but maybe i had ions in so these are the + + + align:start position:0% +but maybe i had ions in so these are the +ions so maybe i add a whole bunch of + + align:start position:0% +ions so maybe i add a whole bunch of + + + align:start position:0% +ions so maybe i add a whole bunch of +ions well they're just going to + + align:start position:0% +ions well they're just going to + + + align:start position:0% +ions well they're just going to +precipitate i can't be here + + align:start position:0% +precipitate i can't be here + + + align:start position:0% +precipitate i can't be here +and be in equilibrium that's the point + + align:start position:0% +and be in equilibrium that's the point + + + align:start position:0% +and be in equilibrium that's the point +of the green curve this k + + align:start position:0% +of the green curve this k + + + align:start position:0% +of the green curve this k +doesn't change this k is is this k + + align:start position:0% +doesn't change this k is is this k + + + align:start position:0% +doesn't change this k is is this k +that's what the green curve is it is + + align:start position:0% +that's what the green curve is it is + + + align:start position:0% +that's what the green curve is it is +that being constant + + align:start position:0% +that being constant + + + align:start position:0% +that being constant +that's very important that is + + align:start position:0% +that's very important that is + + + align:start position:0% +that's very important that is +equilibrium now + + align:start position:0% +equilibrium now + + + align:start position:0% +equilibrium now +there is a way though to move around on + + align:start position:0% +there is a way though to move around on + + + align:start position:0% +there is a way though to move around on +it + + align:start position:0% +it + + + align:start position:0% +it +yeah because if i did imagine now look + + align:start position:0% +yeah because if i did imagine now look + + + align:start position:0% +yeah because if i did imagine now look +at point c + + align:start position:0% +at point c + + + align:start position:0% +at point c +now imagine now that i've i've found + + align:start position:0% +now imagine now that i've i've found + + + align:start position:0% +now imagine now that i've i've found +some source of chlorine ions + + align:start position:0% +some source of chlorine ions + + + align:start position:0% +some source of chlorine ions +and i add a whole bunch of them + + align:start position:0% +and i add a whole bunch of them + + + align:start position:0% +and i add a whole bunch of them +right a whole bunch of them into this + + align:start position:0% +right a whole bunch of them into this + + + align:start position:0% +right a whole bunch of them into this +solution i don't add silver + + align:start position:0% +solution i don't add silver + + + align:start position:0% +solution i don't add silver +and chlorine together i just add + + align:start position:0% +and chlorine together i just add + + + align:start position:0% +and chlorine together i just add +chlorine well you can see what's going + + align:start position:0% +chlorine well you can see what's going + + + align:start position:0% +chlorine well you can see what's going +to happen + + align:start position:0% +to happen + + + align:start position:0% +to happen +i have to get to equilibrium and so in + + align:start position:0% +i have to get to equilibrium and so in + + + align:start position:0% +i have to get to equilibrium and so in +order to stay + + align:start position:0% +order to stay + + + align:start position:0% +order to stay +in equilibrium for silver chloride in + + align:start position:0% +in equilibrium for silver chloride in + + + align:start position:0% +in equilibrium for silver chloride in +solution then + + align:start position:0% +solution then + + + align:start position:0% +solution then +i must lower my concentration of silver + + align:start position:0% +i must lower my concentration of silver + + + align:start position:0% +i must lower my concentration of silver +because i added all this chlorine right + + align:start position:0% +because i added all this chlorine right + + + align:start position:0% +because i added all this chlorine right +well the only way to do that + + align:start position:0% +well the only way to do that + + + align:start position:0% +well the only way to do that +is to eat up some silver and precipitate + + align:start position:0% +is to eat up some silver and precipitate + + + align:start position:0% +is to eat up some silver and precipitate +that's the only way to do that and that + + align:start position:0% +that's the only way to do that and that + + + align:start position:0% +that's the only way to do that and that +has a name + + align:start position:0% +has a name + + + align:start position:0% +has a name +and that's what i want to talk about + + align:start position:0% +and that's what i want to talk about + + + align:start position:0% +and that's what i want to talk about +next that is called + + align:start position:0% +next that is called + + + align:start position:0% +next that is called +the common ion effect + + align:start position:0% + + + + align:start position:0% + +now this is an example this + + align:start position:0% +now this is an example this + + + align:start position:0% +now this is an example this +is an example of a broader principle + + align:start position:0% +is an example of a broader principle + + + align:start position:0% +is an example of a broader principle +which is which i mentioned monday which + + align:start position:0% +which is which i mentioned monday which + + + align:start position:0% +which is which i mentioned monday which +is le chatelier's principle + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +and that is that position of + + align:start position:0% +and that is that position of + + + align:start position:0% +and that is that position of +position of equilibrium + + align:start position:0% + + + + align:start position:0% + +will move it's still equilibrium but + + align:start position:0% +will move it's still equilibrium but + + + align:start position:0% +will move it's still equilibrium but +it's moving + + align:start position:0% +it's moving + + + align:start position:0% +it's moving +on that green curve right to counteract + + align:start position:0% +on that green curve right to counteract + + + align:start position:0% +on that green curve right to counteract +change + + align:start position:0% + + + + align:start position:0% + +this is a very uh + + align:start position:0% +this is a very uh + + + align:start position:0% +this is a very uh +general principle it applies to many + + align:start position:0% +general principle it applies to many + + + align:start position:0% +general principle it applies to many +many things it's + + align:start position:0% +many things it's + + + align:start position:0% +many things it's +done not just concentrations it applies + + align:start position:0% +done not just concentrations it applies + + + align:start position:0% +done not just concentrations it applies +to changes in pressure + + align:start position:0% +to changes in pressure + + + align:start position:0% +to changes in pressure +and other changes that you can make in a + + align:start position:0% +and other changes that you can make in a + + + align:start position:0% +and other changes that you can make in a +system here we care about concentration + + align:start position:0% +system here we care about concentration + + + align:start position:0% +system here we care about concentration +and in this particular case we're going + + align:start position:0% +and in this particular case we're going + + + align:start position:0% +and in this particular case we're going +to see it for what happens when you add + + align:start position:0% +to see it for what happens when you add + + + align:start position:0% +to see it for what happens when you add +ions right of one particular type + + align:start position:0% +ions right of one particular type + + + align:start position:0% +ions right of one particular type +and not the other that's the common ion + + align:start position:0% +and not the other that's the common ion + + + align:start position:0% +and not the other that's the common ion +effect + + align:start position:0% +effect + + + align:start position:0% +effect +but it's a very general effect that it + + align:start position:0% +but it's a very general effect that it + + + align:start position:0% +but it's a very general effect that it +resists the change + + align:start position:0% +resists the change + + + align:start position:0% +resists the change +now let's see how that works + + align:start position:0% +now let's see how that works + + + align:start position:0% +now let's see how that works +my if i um if i want a source of ions + + align:start position:0% +my if i um if i want a source of ions + + + align:start position:0% +my if i um if i want a source of ions +let's say i want a source of chlorine + + align:start position:0% +let's say i want a source of chlorine + + + align:start position:0% +let's say i want a source of chlorine +one way would be to add a whole bunch of + + align:start position:0% +one way would be to add a whole bunch of + + + align:start position:0% +one way would be to add a whole bunch of +sodium chloride + + align:start position:0% +sodium chloride + + + align:start position:0% +sodium chloride +right so let's suppose that i have + + align:start position:0% +right so let's suppose that i have + + + align:start position:0% +right so let's suppose that i have +um okay so i'm going to add + + align:start position:0% +um okay so i'm going to add + + + align:start position:0% +um okay so i'm going to add +as an example i'm going to add + + align:start position:0% +as an example i'm going to add + + + align:start position:0% +as an example i'm going to add +to this nice equilibrium that i reached + + align:start position:0% +to this nice equilibrium that i reached + + + align:start position:0% +to this nice equilibrium that i reached +here so i'm at point b + + align:start position:0% +here so i'm at point b + + + align:start position:0% +here so i'm at point b +okay and i'm going to add + + align:start position:0% + + + + align:start position:0% + +0.1 mol + + align:start position:0% +0.1 mol + + + align:start position:0% +0.1 mol +moles per liter of sodium chloride + + align:start position:0% +moles per liter of sodium chloride + + + align:start position:0% +moles per liter of sodium chloride +and this nearly + + align:start position:0% +and this nearly + + + align:start position:0% +and this nearly +and so we're going to say it does it + + align:start position:0% +and so we're going to say it does it + + + align:start position:0% +and so we're going to say it does it +nearly fully dissociates + + align:start position:0% + + + + align:start position:0% + +and we'll be talking about that later + + align:start position:0% +and we'll be talking about that later + + + align:start position:0% +and we'll be talking about that later +today and so that means that that this + + align:start position:0% +today and so that means that that this + + + align:start position:0% +today and so that means that that this +goes nacl + + align:start position:0% +goes nacl + + + align:start position:0% +goes nacl +basically goes to na plus plus cl minus + + align:start position:0% +basically goes to na plus plus cl minus + + + align:start position:0% +basically goes to na plus plus cl minus +both in solution so if i put point + + align:start position:0% +both in solution so if i put point + + + align:start position:0% +both in solution so if i put point +if i put 0.1 moles per liter of sodium + + align:start position:0% +if i put 0.1 moles per liter of sodium + + + align:start position:0% +if i put 0.1 moles per liter of sodium +chloride into this + + align:start position:0% +chloride into this + + + align:start position:0% +chloride into this +into this uh container of the silver + + align:start position:0% +into this uh container of the silver + + + align:start position:0% +into this uh container of the silver +chloride + + align:start position:0% +chloride + + + align:start position:0% +chloride +i'm basically going to get point one + + align:start position:0% +i'm basically going to get point one + + + align:start position:0% +i'm basically going to get point one +because of the stoichiometric + + align:start position:0% +because of the stoichiometric + + + align:start position:0% +because of the stoichiometric +coefficient + + align:start position:0% +coefficient + + + align:start position:0% +coefficient +one one one right yeah so if i put .1 + + align:start position:0% +one one one right yeah so if i put .1 + + + align:start position:0% +one one one right yeah so if i put .1 +moles per liter of this i'm going to + + align:start position:0% +moles per liter of this i'm going to + + + align:start position:0% +moles per liter of this i'm going to +have + + align:start position:0% +have + + + align:start position:0% +have +0.1 moles per liter of chlorine ions + + align:start position:0% +0.1 moles per liter of chlorine ions + + + align:start position:0% +0.1 moles per liter of chlorine ions +that i just dumped into the container + + align:start position:0% +that i just dumped into the container + + + align:start position:0% +that i just dumped into the container +but the sodium doesn't it the sodium is + + align:start position:0% +but the sodium doesn't it the sodium is + + + align:start position:0% +but the sodium doesn't it the sodium is +not going to do anything + + align:start position:0% +not going to do anything + + + align:start position:0% +not going to do anything +but it's just look at the chlorine + + align:start position:0% +but it's just look at the chlorine + + + align:start position:0% +but it's just look at the chlorine +that's going to mess + + align:start position:0% +that's going to mess + + + align:start position:0% +that's going to mess +with my equilibrium but k + + align:start position:0% +with my equilibrium but k + + + align:start position:0% +with my equilibrium but k +is a constant so let's see what happens + + align:start position:0% +is a constant so let's see what happens + + + align:start position:0% +is a constant so let's see what happens +we can do it + + align:start position:0% +we can do it + + + align:start position:0% +we can do it +we can do it visually but we can also do + + align:start position:0% +we can do it visually but we can also do + + + align:start position:0% +we can do it visually but we can also do +it back when we use the ice table + + align:start position:0% +it back when we use the ice table + + + align:start position:0% +it back when we use the ice table +right so so now we're going to go ice + + align:start position:0% +right so so now we're going to go ice + + + align:start position:0% +right so so now we're going to go ice +again a g + + align:start position:0% +again a g + + + align:start position:0% +again a g +c l and here's uh + + align:start position:0% +c l and here's uh + + + align:start position:0% +c l and here's uh +a g plus okay and here's + + align:start position:0% +a g plus okay and here's + + + align:start position:0% +a g plus okay and here's +c l minus so now i've added the okay so + + align:start position:0% +c l minus so now i've added the okay so + + + align:start position:0% +c l minus so now i've added the okay so +my initial + + align:start position:0% +my initial + + + align:start position:0% +my initial +is that this is solid remember it's it's + + align:start position:0% +is that this is solid remember it's it's + + + align:start position:0% +is that this is solid remember it's it's +this is the + + align:start position:0% +this is the + + + align:start position:0% +this is the +the solid of the that i'm putting in + + align:start position:0% +the solid of the that i'm putting in + + + align:start position:0% +the solid of the that i'm putting in +there and then i + + align:start position:0% +there and then i + + + align:start position:0% +there and then i +i started my initial is that i started + + align:start position:0% +i started my initial is that i started + + + align:start position:0% +i started my initial is that i started +in that nice equilibrium at point b + + align:start position:0% +in that nice equilibrium at point b + + + align:start position:0% +in that nice equilibrium at point b +so i've got 1.3 times 10 to the minus + + align:start position:0% +so i've got 1.3 times 10 to the minus + + + align:start position:0% +so i've got 1.3 times 10 to the minus +fifth + + align:start position:0% +fifth + + + align:start position:0% +fifth +and over here i've got the same + + align:start position:0% + + + + align:start position:0% + +but now the change now the change + + align:start position:0% +but now the change now the change + + + align:start position:0% +but now the change now the change +we're gonna add okay so we're gonna add + + align:start position:0% +we're gonna add okay so we're gonna add + + + align:start position:0% +we're gonna add okay so we're gonna add +some chlorine ions 0.1 + + align:start position:0% +some chlorine ions 0.1 + + + align:start position:0% +some chlorine ions 0.1 +so i've added 0.1 moles per liter of + + align:start position:0% +so i've added 0.1 moles per liter of + + + align:start position:0% +so i've added 0.1 moles per liter of +chlorine ions from the salt + + align:start position:0% +chlorine ions from the salt + + + align:start position:0% +chlorine ions from the salt +from sodium chloride yeah but now some + + align:start position:0% +from sodium chloride yeah but now some + + + align:start position:0% +from sodium chloride yeah but now some +of that is going to + + align:start position:0% +of that is going to + + + align:start position:0% +of that is going to +react because as i just said le + + align:start position:0% +react because as i just said le + + + align:start position:0% +react because as i just said le +chatelier's principle tells me that now + + align:start position:0% +chatelier's principle tells me that now + + + align:start position:0% +chatelier's principle tells me that now +there's it's got to counter that and you + + align:start position:0% +there's it's got to counter that and you + + + align:start position:0% +there's it's got to counter that and you +can see it right here too + + align:start position:0% +can see it right here too + + + align:start position:0% +can see it right here too +i'm adding a whole bunch of chlorine so + + align:start position:0% +i'm adding a whole bunch of chlorine so + + + align:start position:0% +i'm adding a whole bunch of chlorine so +i'm going look at how far i'm going out + + align:start position:0% +i'm going look at how far i'm going out + + + align:start position:0% +i'm going look at how far i'm going out +point one that's like literally all the + + align:start position:0% +point one that's like literally all the + + + align:start position:0% +point one that's like literally all the +way out to here + + align:start position:0% +way out to here + + + align:start position:0% +way out to here +and so and so the amount of silver has + + align:start position:0% +and so and so the amount of silver has + + + align:start position:0% +and so and so the amount of silver has +got to go down + + align:start position:0% +got to go down + + + align:start position:0% +got to go down +and what's going to happen is it's going + + align:start position:0% +and what's going to happen is it's going + + + align:start position:0% +and what's going to happen is it's going +to consume + + align:start position:0% +to consume + + + align:start position:0% +to consume +some of the silver and form precipitate + + align:start position:0% +some of the silver and form precipitate + + + align:start position:0% +some of the silver and form precipitate +to counter + + align:start position:0% +to counter + + + align:start position:0% +to counter +all this addition it's going to run the + + align:start position:0% +all this addition it's going to run the + + + align:start position:0% +all this addition it's going to run the +reaction the other way + + align:start position:0% +reaction the other way + + + align:start position:0% +reaction the other way +so it's going to lose a little bit there + + align:start position:0% +so it's going to lose a little bit there + + + align:start position:0% +so it's going to lose a little bit there +from the point 1 that's going to react + + align:start position:0% +from the point 1 that's going to react + + + align:start position:0% +from the point 1 that's going to react +with + + align:start position:0% +with + + + align:start position:0% +with +the silver ions so that's going to also + + align:start position:0% +the silver ions so that's going to also + + + align:start position:0% +the silver ions so that's going to also +lose and this is going to gain + + align:start position:0% +lose and this is going to gain + + + align:start position:0% +lose and this is going to gain +that's how much that's going to get so + + align:start position:0% +that's how much that's going to get so + + + align:start position:0% +that's how much that's going to get so +those are the variables right this is + + align:start position:0% +those are the variables right this is + + + align:start position:0% +those are the variables right this is +the ice table + + align:start position:0% +the ice table + + + align:start position:0% +the ice table +that's how much how much it's going to + + align:start position:0% +that's how much how much it's going to + + + align:start position:0% +that's how much how much it's going to +look these are going to react + + align:start position:0% +look these are going to react + + + align:start position:0% +look these are going to react +to give me some precipitate and so the + + align:start position:0% +to give me some precipitate and so the + + + align:start position:0% +to give me some precipitate and so the +equilibrium + + align:start position:0% +equilibrium + + + align:start position:0% +equilibrium +is more okay more solid + + align:start position:0% +is more okay more solid + + + align:start position:0% +is more okay more solid +forms that's not a good e + + align:start position:0% +forms that's not a good e + + + align:start position:0% +forms that's not a good e +more solid forms and over here it's 1.3 + + align:start position:0% +more solid forms and over here it's 1.3 + + + align:start position:0% +more solid forms and over here it's 1.3 +times 10 to the minus fifth minus x + + align:start position:0% +times 10 to the minus fifth minus x + + + align:start position:0% +times 10 to the minus fifth minus x +and over here it's 0.1 minus x + + align:start position:0% +and over here it's 0.1 minus x + + + align:start position:0% +and over here it's 0.1 minus x +that's the equilibrium condition i've + + align:start position:0% +that's the equilibrium condition i've + + + align:start position:0% +that's the equilibrium condition i've +added in a common ion this is the common + + align:start position:0% +added in a common ion this is the common + + + align:start position:0% +added in a common ion this is the common +ion effect + + align:start position:0% +ion effect + + + align:start position:0% +ion effect +and so now if you do the math + + align:start position:0% +and so now if you do the math + + + align:start position:0% +and so now if you do the math +then what happens + + align:start position:0% +then what happens + + + align:start position:0% +then what happens +well again ksp + + align:start position:0% +well again ksp + + + align:start position:0% +well again ksp +is the same it's the equilibrium + + align:start position:0% +is the same it's the equilibrium + + + align:start position:0% +is the same it's the equilibrium +constant so it's the constant + + align:start position:0% +constant so it's the constant + + + align:start position:0% +constant so it's the constant +so that is going to be the same value + + align:start position:0% +so that is going to be the same value + + + align:start position:0% +so that is going to be the same value +it's going to be 1.7 + + align:start position:0% +it's going to be 1.7 + + + align:start position:0% +it's going to be 1.7 +times 10 to the minus 10th but you see + + align:start position:0% +times 10 to the minus 10th but you see + + + align:start position:0% +times 10 to the minus 10th but you see +ksp + + align:start position:0% +ksp + + + align:start position:0% +ksp +is also equal to the concentration in + + align:start position:0% +is also equal to the concentration in + + + align:start position:0% +is also equal to the concentration in +equilibrium + + align:start position:0% +equilibrium + + + align:start position:0% +equilibrium +of the silver ions times the + + align:start position:0% +of the silver ions times the + + + align:start position:0% +of the silver ions times the +concentration of the chlorine ion so + + align:start position:0% +concentration of the chlorine ion so + + + align:start position:0% +concentration of the chlorine ion so +it's going to be + + align:start position:0% +it's going to be + + + align:start position:0% +it's going to be +0.1 minus x times 1.3 + + align:start position:0% +0.1 minus x times 1.3 + + + align:start position:0% +0.1 minus x times 1.3 +times 10 to the fifth minus x + + align:start position:0% + + + + align:start position:0% + +and then we don't like doing all this + + align:start position:0% +and then we don't like doing all this + + + align:start position:0% +and then we don't like doing all this +math and so we simplify + + align:start position:0% +math and so we simplify + + + align:start position:0% +math and so we simplify +then we can simplify because look + + align:start position:0% +then we can simplify because look + + + align:start position:0% +then we can simplify because look +you started with silver ions in a very + + align:start position:0% +you started with silver ions in a very + + + align:start position:0% +you started with silver ions in a very +small concentration + + align:start position:0% +small concentration + + + align:start position:0% +small concentration +x can't be you can't take away something + + align:start position:0% +x can't be you can't take away something + + + align:start position:0% +x can't be you can't take away something +you don't have + + align:start position:0% +you don't have + + + align:start position:0% +you don't have +right and and so x has got to be somehow + + align:start position:0% +right and and so x has got to be somehow + + + align:start position:0% +right and and so x has got to be somehow +this or less right and so x is a small + + align:start position:0% +this or less right and so x is a small + + + align:start position:0% +this or less right and so x is a small +number + + align:start position:0% +number + + + align:start position:0% +number +and this is a really big number in + + align:start position:0% +and this is a really big number in + + + align:start position:0% +and this is a really big number in +comparison + + align:start position:0% +comparison + + + align:start position:0% +comparison +and so we like simplifying our lives + + align:start position:0% +and so we like simplifying our lives + + + align:start position:0% +and so we like simplifying our lives +right + + align:start position:0% +right + + + align:start position:0% +right +and so we we like saying that that's + + align:start position:0% +and so we we like saying that that's + + + align:start position:0% +and so we we like saying that that's +like point one + + align:start position:0% +like point one + + + align:start position:0% +like point one +we know that that'll make the math a lot + + align:start position:0% +we know that that'll make the math a lot + + + align:start position:0% +we know that that'll make the math a lot +easier right + + align:start position:0% +easier right + + + align:start position:0% +easier right +that'll make the math a lot easier and + + align:start position:0% +that'll make the math a lot easier and + + + align:start position:0% +that'll make the math a lot easier and +so + + align:start position:0% +so + + + align:start position:0% +so +now we can say that this is equal to + + align:start position:0% +now we can say that this is equal to + + + align:start position:0% +now we can say that this is equal to +uh okay 0.1 + + align:start position:0% +uh okay 0.1 + + + align:start position:0% +uh okay 0.1 +times 1.3 times 10 to the minus fifth + + align:start position:0% +times 1.3 times 10 to the minus fifth + + + align:start position:0% +times 1.3 times 10 to the minus fifth +minus x and then we get that x + + align:start position:0% +minus x and then we get that x + + + align:start position:0% +minus x and then we get that x +equals 1.7 times 10 to the minus ninth + + align:start position:0% +equals 1.7 times 10 to the minus ninth + + + align:start position:0% +equals 1.7 times 10 to the minus ninth +that is the common ion effect what i've + + align:start position:0% +that is the common ion effect what i've + + + align:start position:0% +that is the common ion effect what i've +done i've taken this thing in + + align:start position:0% +done i've taken this thing in + + + align:start position:0% +done i've taken this thing in +equilibrium and i've added one of the + + align:start position:0% +equilibrium and i've added one of the + + + align:start position:0% +equilibrium and i've added one of the +ions + + align:start position:0% +ions + + + align:start position:0% +ions +right and and and it changes the + + align:start position:0% +right and and and it changes the + + + align:start position:0% +right and and and it changes the +solubility remember the solubility is + + align:start position:0% +solubility remember the solubility is + + + align:start position:0% +solubility remember the solubility is +what we care about + + align:start position:0% +what we care about + + + align:start position:0% +what we care about +that's what the solubility product the + + align:start position:0% +that's what the solubility product the + + + align:start position:0% +that's what the solubility product the +solubility constant helps us determine + + align:start position:0% +solubility constant helps us determine + + + align:start position:0% +solubility constant helps us determine +and i've literally just changed it by + + align:start position:0% +and i've literally just changed it by + + + align:start position:0% +and i've literally just changed it by +orders of magnitude + + align:start position:0% +orders of magnitude + + + align:start position:0% +orders of magnitude +right because now the the amount that + + align:start position:0% +right because now the the amount that + + + align:start position:0% +right because now the the amount that +this + + align:start position:0% +this + + + align:start position:0% +this +so this thing precipitates like crazy i + + align:start position:0% +so this thing precipitates like crazy i + + + align:start position:0% +so this thing precipitates like crazy i +added in a little bit of some other ion + + align:start position:0% +added in a little bit of some other ion + + + align:start position:0% +added in a little bit of some other ion +that some other salt that had + + align:start position:0% +that some other salt that had + + + align:start position:0% +that some other salt that had +chlorinitis and all of a sudden silver + + align:start position:0% +chlorinitis and all of a sudden silver + + + align:start position:0% +chlorinitis and all of a sudden silver +chloride precipitates out + + align:start position:0% +chloride precipitates out + + + align:start position:0% +chloride precipitates out +right so here's a video of that so this + + align:start position:0% +right so here's a video of that so this + + + align:start position:0% +right so here's a video of that so this +is kind of cool so watch this is a + + align:start position:0% +is kind of cool so watch this is a + + + align:start position:0% +is kind of cool so watch this is a +an equilibrium container and what i'm + + align:start position:0% +an equilibrium container and what i'm + + + align:start position:0% +an equilibrium container and what i'm +adding is salt + + align:start position:0% +adding is salt + + + align:start position:0% +adding is salt +and look at that what is that that's + + align:start position:0% +and look at that what is that that's + + + align:start position:0% +and look at that what is that that's +silver chloride precipitate + + align:start position:0% +silver chloride precipitate + + + align:start position:0% +silver chloride precipitate +right because the thing has to reach + + align:start position:0% +right because the thing has to reach + + + align:start position:0% +right because the thing has to reach +equilibrium + + align:start position:0% +equilibrium + + + align:start position:0% +equilibrium +and so in order to do so what you do is + + align:start position:0% +and so in order to do so what you do is + + + align:start position:0% +and so in order to do so what you do is +you + + align:start position:0% +you + + + align:start position:0% +you +you suppress the solubility you + + align:start position:0% +you suppress the solubility you + + + align:start position:0% +you suppress the solubility you +literally by adding chlorine the common + + align:start position:0% +literally by adding chlorine the common + + + align:start position:0% +literally by adding chlorine the common +ion effect + + align:start position:0% +ion effect + + + align:start position:0% +ion effect +you suppress the solubility of the + + align:start position:0% +you suppress the solubility of the + + + align:start position:0% +you suppress the solubility of the +silver chloride right + + align:start position:0% +silver chloride right + + + align:start position:0% +silver chloride right +it's pretty cool stuff that is the + + align:start position:0% +it's pretty cool stuff that is the + + + align:start position:0% +it's pretty cool stuff that is the +common ion effect now why does this + + align:start position:0% +common ion effect now why does this + + + align:start position:0% +common ion effect now why does this +matter + + align:start position:0% +matter + + + align:start position:0% +matter +oh let me give you one i'll get to why + + align:start position:0% +oh let me give you one i'll get to why + + + align:start position:0% +oh let me give you one i'll get to why +this matters in a second + + align:start position:0% +this matters in a second + + + align:start position:0% +this matters in a second +one more question so you can now without + + align:start position:0% +one more question so you can now without + + + align:start position:0% +one more question so you can now without +even doing the math + + align:start position:0% +even doing the math + + + align:start position:0% +even doing the math +check this one out this is cool without + + align:start position:0% +check this one out this is cool without + + + align:start position:0% +check this one out this is cool without +even + + align:start position:0% +even + + + align:start position:0% +even +without even doing the math i can take + + align:start position:0% +without even doing the math i can take + + + align:start position:0% +without even doing the math i can take +barium sulfate + + align:start position:0% +barium sulfate + + + align:start position:0% +barium sulfate +okay and from this from the common ion + + align:start position:0% +okay and from this from the common ion + + + align:start position:0% +okay and from this from the common ion +effect so barium sulfate + + align:start position:0% +effect so barium sulfate + + + align:start position:0% +effect so barium sulfate +is going to go so what does that one + + align:start position:0% +is going to go so what does that one + + + align:start position:0% +is going to go so what does that one +look like well it's going to go to be a + + align:start position:0% +look like well it's going to go to be a + + + align:start position:0% +look like well it's going to go to be a +two plus plus so4 + + align:start position:0% +two plus plus so4 + + + align:start position:0% +two plus plus so4 +two minus both in solution in solution + + align:start position:0% +two minus both in solution in solution + + + align:start position:0% +two minus both in solution in solution +dissolved ions this is a solid + + align:start position:0% +dissolved ions this is a solid + + + align:start position:0% +dissolved ions this is a solid +now which here's the question + + align:start position:0% +now which here's the question + + + align:start position:0% +now which here's the question +which of the following will be required + + align:start position:0% +which of the following will be required + + + align:start position:0% +which of the following will be required +in the least amount to dissolve + + align:start position:0% +in the least amount to dissolve + + + align:start position:0% +in the least amount to dissolve +the same amount of ba so4 + + align:start position:0% +the same amount of ba so4 + + + align:start position:0% +the same amount of ba so4 +i don't need any constants or math i can + + align:start position:0% +i don't need any constants or math i can + + + align:start position:0% +i don't need any constants or math i can +use the same principle because + + align:start position:0% +use the same principle because + + + align:start position:0% +use the same principle because +if i had some 0.1 molar or 0.01 + + align:start position:0% +if i had some 0.1 molar or 0.01 + + + align:start position:0% +if i had some 0.1 molar or 0.01 +moles per liter of either of these what + + align:start position:0% +moles per liter of either of these what + + + align:start position:0% +moles per liter of either of these what +are they doing + + align:start position:0% +are they doing + + + align:start position:0% +are they doing +they're serving up ions right in the one + + align:start position:0% +they're serving up ions right in the one + + + align:start position:0% +they're serving up ions right in the one +case + + align:start position:0% +case + + + align:start position:0% +case +you're serving up in one case you're + + align:start position:0% +you're serving up in one case you're + + + align:start position:0% +you're serving up in one case you're +serving up + + align:start position:0% +serving up + + + align:start position:0% +serving up +so in case a you're going to give me + + align:start position:0% +so in case a you're going to give me + + + align:start position:0% +so in case a you're going to give me +what do i have there h2so4 + + align:start position:0% +what do i have there h2so4 + + + align:start position:0% +what do i have there h2so4 +so let's do a first h2so4 + + align:start position:0% +so let's do a first h2so4 + + + align:start position:0% +so let's do a first h2so4 +is going to give me a whole bunch of h + + align:start position:0% +is going to give me a whole bunch of h + + + align:start position:0% +is going to give me a whole bunch of h +plus + + align:start position:0% +plus + + + align:start position:0% +plus +but also so4 2 minus and + + align:start position:0% +but also so4 2 minus and + + + align:start position:0% +but also so4 2 minus and +in case b you have + + align:start position:0% +in case b you have + + + align:start position:0% +in case b you have +uh bacl okay so you have ba + + align:start position:0% +uh bacl okay so you have ba + + + align:start position:0% +uh bacl okay so you have ba +cl2 and if i put that in i've got this + + align:start position:0% +cl2 and if i put that in i've got this + + + align:start position:0% +cl2 and if i put that in i've got this +in water + + align:start position:0% +in water + + + align:start position:0% +in water +right but if i put but if this dissolves + + align:start position:0% +right but if i put but if this dissolves + + + align:start position:0% +right but if i put but if this dissolves +in water a little bit then it's going to + + align:start position:0% +in water a little bit then it's going to + + + align:start position:0% +in water a little bit then it's going to +serve up + + align:start position:0% +serve up + + + align:start position:0% +serve up +some ba 2 plus plus + + align:start position:0% +some ba 2 plus plus + + + align:start position:0% +some ba 2 plus plus +2 cl minus + + align:start position:0% +2 cl minus + + + align:start position:0% +2 cl minus +either way now you know what's going to + + align:start position:0% +either way now you know what's going to + + + align:start position:0% +either way now you know what's going to +happen + + align:start position:0% +happen + + + align:start position:0% +happen +because if i'm trying to dissolve + + align:start position:0% +because if i'm trying to dissolve + + + align:start position:0% +because if i'm trying to dissolve +something + + align:start position:0% +something + + + align:start position:0% +something +and i add any of the ions + + align:start position:0% +and i add any of the ions + + + align:start position:0% +and i add any of the ions +that it's dissolving into from some + + align:start position:0% +that it's dissolving into from some + + + align:start position:0% +that it's dissolving into from some +external source + + align:start position:0% +external source + + + align:start position:0% +external source +it's going to drive it this way it's + + align:start position:0% +it's going to drive it this way it's + + + align:start position:0% +it's going to drive it this way it's +going to precipitate + + align:start position:0% +going to precipitate + + + align:start position:0% +going to precipitate +right so the answer has to be just water + + align:start position:0% +right so the answer has to be just water + + + align:start position:0% +right so the answer has to be just water +stick with pure water in this case + + align:start position:0% +stick with pure water in this case + + + align:start position:0% +stick with pure water in this case +otherwise you're gonna + + align:start position:0% +otherwise you're gonna + + + align:start position:0% +otherwise you're gonna +you're gonna have more trouble + + align:start position:0% +you're gonna have more trouble + + + align:start position:0% +you're gonna have more trouble +dissolving just like we just showed + + align:start position:0% +dissolving just like we just showed + + + align:start position:0% +dissolving just like we just showed +you're gonna have more trouble + + align:start position:0% +you're gonna have more trouble + + + align:start position:0% +you're gonna have more trouble +dissolving not less that's the common + + align:start position:0% +dissolving not less that's the common + + + align:start position:0% +dissolving not less that's the common +ion effect + + align:start position:0% +ion effect + + + align:start position:0% +ion effect +all right now why okay so now why does + + align:start position:0% +all right now why okay so now why does + + + align:start position:0% +all right now why okay so now why does +this matter + + align:start position:0% +this matter + + + align:start position:0% +this matter +why does this matter oh we go back to + + align:start position:0% +why does this matter oh we go back to + + + align:start position:0% +why does this matter oh we go back to +the terror pot + + align:start position:0% +the terror pot + + + align:start position:0% +the terror pot +and by the way i didn't have this link + + align:start position:0% +and by the way i didn't have this link + + + align:start position:0% +and by the way i didn't have this link +and i should have when i showed you the + + align:start position:0% +and i should have when i showed you the + + + align:start position:0% +and i should have when i showed you the +the and this is your goody bag etc right + + align:start position:0% +the and this is your goody bag etc right + + + align:start position:0% +the and this is your goody bag etc right +there's some really nice uh articles + + align:start position:0% +there's some really nice uh articles + + + align:start position:0% +there's some really nice uh articles +here that you can find related to these + + align:start position:0% +here that you can find related to these + + + align:start position:0% +here that you can find related to these +experiments and other things about ocean + + align:start position:0% +experiments and other things about ocean + + + align:start position:0% +experiments and other things about ocean +acidity + + align:start position:0% +acidity + + + align:start position:0% +acidity +and uh in case you're interested um but + + align:start position:0% +and uh in case you're interested um but + + + align:start position:0% +and uh in case you're interested um but +see + + align:start position:0% +see + + + align:start position:0% +see +what we what i did is was that this was + + align:start position:0% +what we what i did is was that this was + + + align:start position:0% +what we what i did is was that this was +my why this matters on monday + + align:start position:0% +my why this matters on monday + + + align:start position:0% +my why this matters on monday +and i wanted to tell you about the + + align:start position:0% +and i wanted to tell you about the + + + align:start position:0% +and i wanted to tell you about the +goodie bag and about + + align:start position:0% +goodie bag and about + + + align:start position:0% +goodie bag and about +the how things dissolve because monday + + align:start position:0% +the how things dissolve because monday + + + align:start position:0% +the how things dissolve because monday +was about + + align:start position:0% +was about + + + align:start position:0% +was about +dissolving right and finding a + + align:start position:0% +dissolving right and finding a + + + align:start position:0% +dissolving right and finding a +saturation point + + align:start position:0% +saturation point + + + align:start position:0% +saturation point +now we can we can get to the next place + + align:start position:0% +now we can we can get to the next place + + + align:start position:0% +now we can we can get to the next place +which is + + align:start position:0% +which is + + + align:start position:0% +which is +why does that matter for the terrapot + + align:start position:0% +why does that matter for the terrapot + + + align:start position:0% +why does that matter for the terrapot +shell + + align:start position:0% +shell + + + align:start position:0% +shell +what is the chemistry that that matters + + align:start position:0% +what is the chemistry that that matters + + + align:start position:0% +what is the chemistry that that matters +there + + align:start position:0% +there + + + align:start position:0% +there +okay so i made the ocean a little more + + align:start position:0% +okay so i made the ocean a little more + + + align:start position:0% +okay so i made the ocean a little more +acidic + + align:start position:0% +acidic + + + align:start position:0% +acidic +why does that matter but you see now + + align:start position:0% +why does that matter but you see now + + + align:start position:0% +why does that matter but you see now +we're armed with the knowledge we need + + align:start position:0% +we're armed with the knowledge we need + + + align:start position:0% +we're armed with the knowledge we need +to answer that question + + align:start position:0% +to answer that question + + + align:start position:0% +to answer that question +now we're armed with it all we need to + + align:start position:0% +now we're armed with it all we need to + + + align:start position:0% +now we're armed with it all we need to +do as always with everything in life + + align:start position:0% +do as always with everything in life + + + align:start position:0% +do as always with everything in life +is look at the chemistry that's it + + align:start position:0% +is look at the chemistry that's it + + + align:start position:0% +is look at the chemistry that's it +say that at the thanksgiving table + + align:start position:0% +say that at the thanksgiving table + + + align:start position:0% +say that at the thanksgiving table +you'll be very popular + + align:start position:0% +you'll be very popular + + + align:start position:0% +you'll be very popular +we said co2 plus h2o + + align:start position:0% +we said co2 plus h2o + + + align:start position:0% +we said co2 plus h2o +this goes oh + + align:start position:0% +this goes oh + + + align:start position:0% +this goes oh +it finds some equilibrium 2h2 + + align:start position:0% +it finds some equilibrium 2h2 + + + align:start position:0% +it finds some equilibrium 2h2 +co3 now this is called carbonic acid + + align:start position:0% + + + + align:start position:0% + +this is called carbonic acid there's the + + align:start position:0% +this is called carbonic acid there's the + + + align:start position:0% +this is called carbonic acid there's the +pteropod up there + + align:start position:0% +pteropod up there + + + align:start position:0% +pteropod up there +and there's a reaction that's that's + + align:start position:0% +and there's a reaction that's that's + + + align:start position:0% +and there's a reaction that's that's +really relevant that you'll see from the + + align:start position:0% +really relevant that you'll see from the + + + align:start position:0% +really relevant that you'll see from the +ones we're about to write down why + + align:start position:0% +ones we're about to write down why + + + align:start position:0% +ones we're about to write down why +because the thing is that why what + + align:start position:0% +because the thing is that why what + + + align:start position:0% +because the thing is that why what +happens to carbonic acid + + align:start position:0% +happens to carbonic acid + + + align:start position:0% +happens to carbonic acid +that well carbonic acid also goes + + align:start position:0% +that well carbonic acid also goes + + + align:start position:0% +that well carbonic acid also goes +through + + align:start position:0% +through + + + align:start position:0% +through +a dissolution reaction so carbonic acid + + align:start position:0% +a dissolution reaction so carbonic acid + + + align:start position:0% +a dissolution reaction so carbonic acid +so this is co2 + + align:start position:0% +so this is co2 + + + align:start position:0% +so this is co2 +dissolving in water now we make carbon + + align:start position:0% +dissolving in water now we make carbon + + + align:start position:0% +dissolving in water now we make carbon +so carbonic acid + + align:start position:0% +so carbonic acid + + + align:start position:0% +so carbonic acid +uh goes like this okay + + align:start position:0% +uh goes like this okay + + + align:start position:0% +uh goes like this okay +it goes into h co three minus + + align:start position:0% +it goes into h co three minus + + + align:start position:0% +it goes into h co three minus +plus h plus + + align:start position:0% +plus h plus + + + align:start position:0% +plus h plus +now here's the thing okay what is the + + align:start position:0% +now here's the thing okay what is the + + + align:start position:0% +now here's the thing okay what is the +shell made of + + align:start position:0% +shell made of + + + align:start position:0% +shell made of +well the shell that's dissolving in + + align:start position:0% +well the shell that's dissolving in + + + align:start position:0% +well the shell that's dissolving in +in its you know kind of like the core + + align:start position:0% +in its you know kind of like the core + + + align:start position:0% +in its you know kind of like the core +material is calcium carbonate + + align:start position:0% +material is calcium carbonate + + + align:start position:0% +material is calcium carbonate +so that's caco3 + + align:start position:0% +so that's caco3 + + + align:start position:0% +so that's caco3 +that's the shell and the shell also has + + align:start position:0% +that's the shell and the shell also has + + + align:start position:0% +that's the shell and the shell also has +an equilibrium reaction that happens + + align:start position:0% +an equilibrium reaction that happens + + + align:start position:0% +an equilibrium reaction that happens +the shell of of of a c a creature is in + + align:start position:0% +the shell of of of a c a creature is in + + + align:start position:0% +the shell of of of a c a creature is in +dynamic equilibrium with the ocean + + align:start position:0% +dynamic equilibrium with the ocean + + + align:start position:0% +dynamic equilibrium with the ocean +and and so it's going like this it's + + align:start position:0% +and and so it's going like this it's + + + align:start position:0% +and and so it's going like this it's +going to uh well okay + + align:start position:0% +going to uh well okay + + + align:start position:0% +going to uh well okay +c a two plus and + + align:start position:0% +c a two plus and + + + align:start position:0% +c a two plus and +c o three two minus and + + align:start position:0% +c o three two minus and + + + align:start position:0% +c o three two minus and +and and okay but the thing is it has an + + align:start position:0% +and and okay but the thing is it has an + + + align:start position:0% +and and okay but the thing is it has an +equilibrium constant all these have + + align:start position:0% +equilibrium constant all these have + + + align:start position:0% +equilibrium constant all these have +equilibrium constants + + align:start position:0% +equilibrium constants + + + align:start position:0% +equilibrium constants +so like for example for this one the k + + align:start position:0% +so like for example for this one the k + + + align:start position:0% +so like for example for this one the k +sp + + align:start position:0% +sp + + + align:start position:0% +sp +the solubility product constant because + + align:start position:0% +the solubility product constant because + + + align:start position:0% +the solubility product constant because +this is a solid this is a solid shell + + align:start position:0% +this is a solid this is a solid shell + + + align:start position:0% +this is a solid this is a solid shell +solid going to ions in aqueous solution + + align:start position:0% + + + + align:start position:0% + +but so the ksp for that is somewhere + + align:start position:0% +but so the ksp for that is somewhere + + + align:start position:0% +but so the ksp for that is somewhere +around 5 + + align:start position:0% +around 5 + + + align:start position:0% +around 5 +times 10 to the minus 9. + + align:start position:0% +times 10 to the minus 9. + + + align:start position:0% +times 10 to the minus 9. +5 times 10 to the minus 9. yeah but + + align:start position:0% +5 times 10 to the minus 9. yeah but + + + align:start position:0% +5 times 10 to the minus 9. yeah but +here's the thing we just went through + + align:start position:0% +here's the thing we just went through + + + align:start position:0% +here's the thing we just went through +this + + align:start position:0% +this + + + align:start position:0% +this +if i consume one of these or change the + + align:start position:0% +if i consume one of these or change the + + + align:start position:0% +if i consume one of these or change the +concentration of + + align:start position:0% +concentration of + + + align:start position:0% +concentration of +one of these and not the other + + align:start position:0% +one of these and not the other + + + align:start position:0% +one of these and not the other +we just did this if i if i change the + + align:start position:0% +we just did this if i if i change the + + + align:start position:0% +we just did this if i if i change the +concentration if i consume + + align:start position:0% +concentration if i consume + + + align:start position:0% +concentration if i consume +any of these then i might drive the + + align:start position:0% +any of these then i might drive the + + + align:start position:0% +any of these then i might drive the +reaction + + align:start position:0% +reaction + + + align:start position:0% +reaction +consume or produce if i change any of + + align:start position:0% +consume or produce if i change any of + + + align:start position:0% +consume or produce if i change any of +these + + align:start position:0% +these + + + align:start position:0% +these +independently i'm going to drive the + + align:start position:0% +independently i'm going to drive the + + + align:start position:0% +independently i'm going to drive the +reaction because that's + + align:start position:0% +reaction because that's + + + align:start position:0% +reaction because that's +how we keep to our k that's what le + + align:start position:0% +how we keep to our k that's what le + + + align:start position:0% +how we keep to our k that's what le +chatelier's principle tells us + + align:start position:0% +chatelier's principle tells us + + + align:start position:0% +chatelier's principle tells us +and so what ends up happening is you've + + align:start position:0% +and so what ends up happening is you've + + + align:start position:0% +and so what ends up happening is you've +got + + align:start position:0% +got + + + align:start position:0% +got +the extra h + + align:start position:0% +the extra h + + + align:start position:0% +the extra h +plus ions so these are ions in solution + + align:start position:0% +plus ions so these are ions in solution + + + align:start position:0% +plus ions so these are ions in solution +where did they come from they came from + + align:start position:0% +where did they come from they came from + + + align:start position:0% +where did they come from they came from +the co2 giving us + + align:start position:0% +the co2 giving us + + + align:start position:0% +the co2 giving us +carbonic acid which then gave us h plus + + align:start position:0% +carbonic acid which then gave us h plus + + + align:start position:0% +carbonic acid which then gave us h plus +those are what i'm talking about + + align:start position:0% +those are what i'm talking about + + + align:start position:0% +those are what i'm talking about +well they react + + align:start position:0% + + + + align:start position:0% + +with the co3 minus + + align:start position:0% +with the co3 minus + + + align:start position:0% +with the co3 minus +3032 minus + + align:start position:0% + + + + align:start position:0% + +this lowers the co32 minus concentration + + align:start position:0% +this lowers the co32 minus concentration + + + align:start position:0% +this lowers the co32 minus concentration +near the shell right because then tight + + align:start position:0% +near the shell right because then tight + + + align:start position:0% +near the shell right because then tight +and if i lower this because i've taken + + align:start position:0% +and if i lower this because i've taken + + + align:start position:0% +and if i lower this because i've taken +some of this now and i've reacted it + + align:start position:0% +some of this now and i've reacted it + + + align:start position:0% +some of this now and i've reacted it +so now i've got less of it and because + + align:start position:0% +so now i've got less of it and because + + + align:start position:0% +so now i've got less of it and because +of what we just saw if i've got less of + + align:start position:0% +of what we just saw if i've got less of + + + align:start position:0% +of what we just saw if i've got less of +this you're going to drive + + align:start position:0% +this you're going to drive + + + align:start position:0% +this you're going to drive +this way which is going to dissolve + + align:start position:0% +this way which is going to dissolve + + + align:start position:0% +this way which is going to dissolve +more of the shell right that's why this + + align:start position:0% +more of the shell right that's why this + + + align:start position:0% +more of the shell right that's why this +works + + align:start position:0% +works + + + align:start position:0% +works +that's why this this happens + + align:start position:0% +that's why this this happens + + + align:start position:0% +that's why this this happens +works sounds like a positive thing right + + align:start position:0% +works sounds like a positive thing right + + + align:start position:0% +works sounds like a positive thing right +so this lowers + + align:start position:0% + + + + align:start position:0% + +the concentration of co32 minus + + align:start position:0% +the concentration of co32 minus + + + align:start position:0% +the concentration of co32 minus +and that drives + + align:start position:0% + + + + align:start position:0% + +more dissolution + + align:start position:0% +more dissolution + + + align:start position:0% +more dissolution +that is what's happening and we now can + + align:start position:0% +that is what's happening and we now can + + + align:start position:0% +that is what's happening and we now can +understand it in terms of the concepts + + align:start position:0% +understand it in terms of the concepts + + + align:start position:0% +understand it in terms of the concepts +that we've just learned + + align:start position:0% + + + + align:start position:0% + +historically i mentioned 50 million + + align:start position:0% +historically i mentioned 50 million + + + align:start position:0% +historically i mentioned 50 million +years actually by some accounts it's 300 + + align:start position:0% +years actually by some accounts it's 300 + + + align:start position:0% +years actually by some accounts it's 300 +million + + align:start position:0% +million + + + align:start position:0% +million +it depends on which studies you read + + align:start position:0% +it depends on which studies you read + + + align:start position:0% +it depends on which studies you read +but but for at least 50 and maybe as + + align:start position:0% +but but for at least 50 and maybe as + + + align:start position:0% +but but for at least 50 and maybe as +much as 300 million years the ocean + + align:start position:0% +much as 300 million years the ocean + + + align:start position:0% +much as 300 million years the ocean +uh has had a ph of 8.18 + + align:start position:0% +uh has had a ph of 8.18 + + + align:start position:0% +uh has had a ph of 8.18 +now where's the oh yeah right + + align:start position:0% +now where's the oh yeah right + + + align:start position:0% +now where's the oh yeah right +so let's just say you know + + align:start position:0% +so let's just say you know + + + align:start position:0% +so let's just say you know +last 0 50 to 300 million + + align:start position:0% +last 0 50 to 300 million + + + align:start position:0% +last 0 50 to 300 million +ish years + + align:start position:0% +ish years + + + align:start position:0% +ish years +the ocean ph + + align:start position:0% +the ocean ph + + + align:start position:0% +the ocean ph +was 8.18 and today + + align:start position:0% +was 8.18 and today + + + align:start position:0% +was 8.18 and today +it's 8.07 + + align:start position:0% +it's 8.07 + + + align:start position:0% +it's 8.07 +and the prediction is that in 2100 + + align:start position:0% +and the prediction is that in 2100 + + + align:start position:0% +and the prediction is that in 2100 +it will be 7.8 + + align:start position:0% +it will be 7.8 + + + align:start position:0% +it will be 7.8 +now as we will see in a little bit and + + align:start position:0% +now as we will see in a little bit and + + + align:start position:0% +now as we will see in a little bit and +he said what's ph + + align:start position:0% +he said what's ph + + + align:start position:0% +he said what's ph +well many of you probably already know + + align:start position:0% +well many of you probably already know + + + align:start position:0% +well many of you probably already know +but we i will tell you what it is in a + + align:start position:0% +but we i will tell you what it is in a + + + align:start position:0% +but we i will tell you what it is in a +little bit + + align:start position:0% +little bit + + + align:start position:0% +little bit +but because this is a logarithmic thing + + align:start position:0% +but because this is a logarithmic thing + + + align:start position:0% +but because this is a logarithmic thing +this is a lot + + align:start position:0% +this is a lot + + + align:start position:0% +this is a lot +right today the ocean is 25 percent more + + align:start position:0% +right today the ocean is 25 percent more + + + align:start position:0% +right today the ocean is 25 percent more +acidic than it's been in 300 million + + align:start position:0% +acidic than it's been in 300 million + + + align:start position:0% +acidic than it's been in 300 million +ish years and in 2100 it will be 126 + + align:start position:0% +ish years and in 2100 it will be 126 + + + align:start position:0% +ish years and in 2100 it will be 126 +percent + + align:start position:0% +percent + + + align:start position:0% +percent +more acidic that's why they used 7.8 in + + align:start position:0% +more acidic that's why they used 7.8 in + + + align:start position:0% +more acidic that's why they used 7.8 in +in the experiments of the pteropots okay + + align:start position:0% + + + + align:start position:0% + +okay right + + align:start position:0% +okay right + + + align:start position:0% +okay right +why does this happen why is this + + align:start position:0% +why does this happen why is this + + + align:start position:0% +why does this happen why is this +molecule + + align:start position:0% +molecule + + + align:start position:0% +molecule +an acid we're talking about + + align:start position:0% +an acid we're talking about + + + align:start position:0% +an acid we're talking about +acidification of oceans + + align:start position:0% +acidification of oceans + + + align:start position:0% +acidification of oceans +why is this an acid in the first place + + align:start position:0% +why is this an acid in the first place + + + align:start position:0% +why is this an acid in the first place +what does it mean to be an acid and that + + align:start position:0% +what does it mean to be an acid and that + + + align:start position:0% +what does it mean to be an acid and that +is the next topic + + align:start position:0% +is the next topic + + + align:start position:0% +is the next topic +that is what i want to talk about next + + align:start position:0% +that is what i want to talk about next + + + align:start position:0% +that is what i want to talk about next +why what is an acid + + align:start position:0% +why what is an acid + + + align:start position:0% +why what is an acid +and an acid is something that is very + + align:start position:0% +and an acid is something that is very + + + align:start position:0% +and an acid is something that is very +specific it has a very definite + + align:start position:0% +specific it has a very definite + + + align:start position:0% +specific it has a very definite +meaning to it and i want to talk about + + align:start position:0% +meaning to it and i want to talk about + + + align:start position:0% +meaning to it and i want to talk about +that today + + align:start position:0% +that today + + + align:start position:0% +that today +and then we'll continue after the break + + align:start position:0% +and then we'll continue after the break + + + align:start position:0% +and then we'll continue after the break +right so + + align:start position:0% + + + + align:start position:0% + +this molecule carbonic acid is called an + + align:start position:0% +this molecule carbonic acid is called an + + + align:start position:0% +this molecule carbonic acid is called an +acid + + align:start position:0% +acid + + + align:start position:0% +acid +because of that proton and you could + + align:start position:0% +because of that proton and you could + + + align:start position:0% +because of that proton and you could +feel it + + align:start position:0% +feel it + + + align:start position:0% +feel it +right you could feel it in this in this + + align:start position:0% +right you could feel it in this in this + + + align:start position:0% +right you could feel it in this in this +whole thing the proton is the part is + + align:start position:0% +whole thing the proton is the part is + + + align:start position:0% +whole thing the proton is the part is +the thing that did the + + align:start position:0% +the thing that did the + + + align:start position:0% +the thing that did the +cause the problem right an acid + + align:start position:0% +cause the problem right an acid + + + align:start position:0% +cause the problem right an acid +this is an acid because of the proton so + + align:start position:0% +this is an acid because of the proton so + + + align:start position:0% +this is an acid because of the proton so +an acid is it's it's a dissolution + + align:start position:0% +an acid is it's it's a dissolution + + + align:start position:0% +an acid is it's it's a dissolution +reaction + + align:start position:0% +reaction + + + align:start position:0% +reaction +dissolution it's what we've been talking + + align:start position:0% +dissolution it's what we've been talking + + + align:start position:0% +dissolution it's what we've been talking +about it's a dissolution + + align:start position:0% +about it's a dissolution + + + align:start position:0% +about it's a dissolution +reaction that + + align:start position:0% +reaction that + + + align:start position:0% +reaction that +gives an h plus + + align:start position:0% + + + + align:start position:0% + +and so now if i think about it as kind + + align:start position:0% +and so now if i think about it as kind + + + align:start position:0% +and so now if i think about it as kind +of a generic case + + align:start position:0% +of a generic case + + + align:start position:0% +of a generic case +generic acid a + + align:start position:0% +generic acid a + + + align:start position:0% +generic acid a +then the reaction looks something like + + align:start position:0% +then the reaction looks something like + + + align:start position:0% +then the reaction looks something like +this + + align:start position:0% +this + + + align:start position:0% +this +i'm going to call out the acid and the + + align:start position:0% +i'm going to call out the acid and the + + + align:start position:0% +i'm going to call out the acid and the +proton that it gives + + align:start position:0% +proton that it gives + + + align:start position:0% +proton that it gives +separately right okay so this is h a so + + align:start position:0% +separately right okay so this is h a so + + + align:start position:0% +separately right okay so this is h a so +we do this because it highlights + + align:start position:0% +we do this because it highlights + + + align:start position:0% +we do this because it highlights +that it's an acid h plus + + align:start position:0% +that it's an acid h plus + + + align:start position:0% +that it's an acid h plus +in solution and these can all be in + + align:start position:0% +in solution and these can all be in + + + align:start position:0% +in solution and these can all be in +solution + + align:start position:0% +solution + + + align:start position:0% +solution +plus a minus in solution + + align:start position:0% +plus a minus in solution + + + align:start position:0% +plus a minus in solution +right h plus a minus + + align:start position:0% +right h plus a minus + + + align:start position:0% +right h plus a minus +right so i've taken a proton off you see + + align:start position:0% +right so i've taken a proton off you see + + + align:start position:0% +right so i've taken a proton off you see +it's right there + + align:start position:0% +it's right there + + + align:start position:0% +it's right there +that's that's h a h a where a + + align:start position:0% +that's that's h a h a where a + + + align:start position:0% +that's that's h a h a where a +is hco3 and h is h and then what i've + + align:start position:0% +is hco3 and h is h and then what i've + + + align:start position:0% +is hco3 and h is h and then what i've +done is i've transferred + + align:start position:0% +done is i've transferred + + + align:start position:0% +done is i've transferred +the proton into solution that's an acid + + align:start position:0% +the proton into solution that's an acid + + + align:start position:0% +the proton into solution that's an acid +now + + align:start position:0% +now + + + align:start position:0% +now +um the thing is one of the things now + + align:start position:0% +um the thing is one of the things now + + + align:start position:0% +um the thing is one of the things now +you will see + + align:start position:0% +you will see + + + align:start position:0% +you will see +a lot of of places and people writing h + + align:start position:0% +a lot of of places and people writing h + + + align:start position:0% +a lot of of places and people writing h +plus and we will do that too because so + + align:start position:0% +plus and we will do that too because so + + + align:start position:0% +plus and we will do that too because so +many textbooks use h plus + + align:start position:0% +many textbooks use h plus + + + align:start position:0% +many textbooks use h plus +but the thing is that h plus what i want + + align:start position:0% +but the thing is that h plus what i want + + + align:start position:0% +but the thing is that h plus what i want +you to know + + align:start position:0% +you to know + + + align:start position:0% +you to know +is that h plus is never a thing + + align:start position:0% +is that h plus is never a thing + + + align:start position:0% +is that h plus is never a thing +we just write it that way h plus is not + + align:start position:0% +we just write it that way h plus is not + + + align:start position:0% +we just write it that way h plus is not +stable in water + + align:start position:0% +stable in water + + + align:start position:0% +stable in water +so the the proper + + align:start position:0% + + + + align:start position:0% + +the proper way to write this general + + align:start position:0% +the proper way to write this general + + + align:start position:0% +the proper way to write this general +reaction would be h + + align:start position:0% +reaction would be h + + + align:start position:0% +reaction would be h +a plus h2o + + align:start position:0% +a plus h2o + + + align:start position:0% +a plus h2o +okay is going to go to and now i'm going + + align:start position:0% +okay is going to go to and now i'm going + + + align:start position:0% +okay is going to go to and now i'm going +to write the full + + align:start position:0% +to write the full + + + align:start position:0% +to write the full +right so the fold goes both ways is + + align:start position:0% +right so the fold goes both ways is + + + align:start position:0% +right so the fold goes both ways is +going to go to h3 + + align:start position:0% +going to go to h3 + + + align:start position:0% +going to go to h3 +o plus plus a minus goes in tight + + align:start position:0% +o plus plus a minus goes in tight + + + align:start position:0% +o plus plus a minus goes in tight +this is what happens because h plus is + + align:start position:0% +this is what happens because h plus is + + + align:start position:0% +this is what happens because h plus is +not stable in water but you will see h + + align:start position:0% +not stable in water but you will see h + + + align:start position:0% +not stable in water but you will see h +plus written all over the place + + align:start position:0% +plus written all over the place + + + align:start position:0% +plus written all over the place +when you see h plus and if it's in water + + align:start position:0% +when you see h plus and if it's in water + + + align:start position:0% +when you see h plus and if it's in water +know + + align:start position:0% +know + + + align:start position:0% +know +that it's h3o plus that is what is + + align:start position:0% +that it's h3o plus that is what is + + + align:start position:0% +that it's h3o plus that is what is +stable + + align:start position:0% +stable + + + align:start position:0% +stable +okay h plus in water is not + + align:start position:0% +okay h plus in water is not + + + align:start position:0% +okay h plus in water is not +now there's something here that's + + align:start position:0% +now there's something here that's + + + align:start position:0% +now there's something here that's +important in terms of terminology + + align:start position:0% +important in terms of terminology + + + align:start position:0% +important in terms of terminology +and that is that these are notice that + + align:start position:0% +and that is that these are notice that + + + align:start position:0% +and that is that these are notice that +these are related + + align:start position:0% +these are related + + + align:start position:0% +these are related +right the h a and the a minus seem very + + align:start position:0% +right the h a and the a minus seem very + + + align:start position:0% +right the h a and the a minus seem very +related and the h2o and the h2o + + align:start position:0% +related and the h2o and the h2o + + + align:start position:0% +related and the h2o and the h2o +h3o plus seem very related well they are + + align:start position:0% +h3o plus seem very related well they are + + + align:start position:0% +h3o plus seem very related well they are +because they're just + + align:start position:0% +because they're just + + + align:start position:0% +because they're just +a proton is the only difference between + + align:start position:0% +a proton is the only difference between + + + align:start position:0% +a proton is the only difference between +them and so those are called conjugate + + align:start position:0% +them and so those are called conjugate + + + align:start position:0% +them and so those are called conjugate +pairs + + align:start position:0% +pairs + + + align:start position:0% +pairs +conjugate related conjugate pairs + + align:start position:0% +conjugate related conjugate pairs + + + align:start position:0% +conjugate related conjugate pairs +okay those are called conjugate pairs + + align:start position:0% + + + + align:start position:0% + +now back in the day there was a lot of + + align:start position:0% +now back in the day there was a lot of + + + align:start position:0% +now back in the day there was a lot of +interest people knew about + + align:start position:0% +interest people knew about + + + align:start position:0% +interest people knew about +these kind of liquids + + align:start position:0% +these kind of liquids + + + align:start position:0% +these kind of liquids +mostly liquids for a long time and there + + align:start position:0% +mostly liquids for a long time and there + + + align:start position:0% +mostly liquids for a long time and there +was a lot of experimentation before this + + align:start position:0% +was a lot of experimentation before this + + + align:start position:0% +was a lot of experimentation before this +let's say well there's these general + + align:start position:0% +let's say well there's these general + + + align:start position:0% +let's say well there's these general +classes of materials + + align:start position:0% +classes of materials + + + align:start position:0% +classes of materials +we're going to call them a and b well a + + align:start position:0% +we're going to call them a and b well a + + + align:start position:0% +we're going to call them a and b well a +seems to always taste kind of sour + + align:start position:0% +seems to always taste kind of sour + + + align:start position:0% +seems to always taste kind of sour +b is bitter a reacts with carbonates + + align:start position:0% +b is bitter a reacts with carbonates + + + align:start position:0% +b is bitter a reacts with carbonates +to make co2 b reacts with fats and soap + + align:start position:0% +to make co2 b reacts with fats and soap + + + align:start position:0% +to make co2 b reacts with fats and soap +to make soaps + + align:start position:0% +to make soaps + + + align:start position:0% +to make soaps +all right one reacts with metals the + + align:start position:0% +all right one reacts with metals the + + + align:start position:0% +all right one reacts with metals the +other doesn't and by the way if we mix + + align:start position:0% +other doesn't and by the way if we mix + + + align:start position:0% +other doesn't and by the way if we mix +them together we seem to always get salt + + align:start position:0% +them together we seem to always get salt + + + align:start position:0% +them together we seem to always get salt +and water + + align:start position:0% +and water + + + align:start position:0% +and water +this had been going on for centuries + + align:start position:0% +this had been going on for centuries + + + align:start position:0% +this had been going on for centuries +this investigation + + align:start position:0% +this investigation + + + align:start position:0% +this investigation +into properties of acids and bases + + align:start position:0% +into properties of acids and bases + + + align:start position:0% +into properties of acids and bases +but who was it that came along who was + + align:start position:0% +but who was it that came along who was + + + align:start position:0% +but who was it that came along who was +it that came along + + align:start position:0% +it that came along + + + align:start position:0% +it that came along +svante is there anything you can't do + + align:start position:0% +svante is there anything you can't do + + + align:start position:0% +svante is there anything you can't do +svonte + + align:start position:0% +svonte + + + align:start position:0% +svonte +i ask you again in the late 1800s + + align:start position:0% +i ask you again in the late 1800s + + + align:start position:0% +i ask you again in the late 1800s +it was svonte to the rescue + + align:start position:0% +it was svonte to the rescue + + + align:start position:0% +it was svonte to the rescue +who first proposed that what is + + align:start position:0% +who first proposed that what is + + + align:start position:0% +who first proposed that what is +happening here + + align:start position:0% +happening here + + + align:start position:0% +happening here +is a dissolution reaction that is what + + align:start position:0% +is a dissolution reaction that is what + + + align:start position:0% +is a dissolution reaction that is what +an acid or base is + + align:start position:0% +an acid or base is + + + align:start position:0% +an acid or base is +it is that in on the one hand you're + + align:start position:0% +it is that in on the one hand you're + + + align:start position:0% +it is that in on the one hand you're +given an h plus + + align:start position:0% +given an h plus + + + align:start position:0% +given an h plus +which is what i just said + + align:start position:0% +which is what i just said + + + align:start position:0% +which is what i just said +but on the other hand + + align:start position:0% +but on the other hand + + + align:start position:0% +but on the other hand +for a base you're given an oh minus and + + align:start position:0% +for a base you're given an oh minus and + + + align:start position:0% +for a base you're given an oh minus and +it was fonte arenas + + align:start position:0% +it was fonte arenas + + + align:start position:0% +it was fonte arenas +who first put that down and first + + align:start position:0% +who first put that down and first + + + align:start position:0% +who first put that down and first +conceived of acids and + + align:start position:0% +conceived of acids and + + + align:start position:0% +conceived of acids and +are we snapping are we quiet snapping + + align:start position:0% +are we snapping are we quiet snapping + + + align:start position:0% +are we snapping are we quiet snapping +for sponte i love it + + align:start position:0% +for sponte i love it + + + align:start position:0% +for sponte i love it +i've just recently learned what that + + align:start position:0% +i've just recently learned what that + + + align:start position:0% +i've just recently learned what that +means it makes me happy + + align:start position:0% +means it makes me happy + + + align:start position:0% +means it makes me happy +quiet snapping it's instead of clapping + + align:start position:0% +quiet snapping it's instead of clapping + + + align:start position:0% +quiet snapping it's instead of clapping +but you don't want to make noise but you + + align:start position:0% +but you don't want to make noise but you + + + align:start position:0% +but you don't want to make noise but you +still want to give props i got it + + align:start position:0% +still want to give props i got it + + + align:start position:0% +still want to give props i got it +i'm there i'm right there now okay so uh + + align:start position:0% +i'm there i'm right there now okay so uh + + + align:start position:0% +i'm there i'm right there now okay so uh +okay + + align:start position:0% +okay + + + align:start position:0% +okay +now here's the thing so we'll talk about + + align:start position:0% +now here's the thing so we'll talk about + + + align:start position:0% +now here's the thing so we'll talk about +so uh okay arrhenius says + + align:start position:0% +so uh okay arrhenius says + + + align:start position:0% +so uh okay arrhenius says +bases give oh ions in solution and + + align:start position:0% +bases give oh ions in solution and + + + align:start position:0% +bases give oh ions in solution and +oh acids give h plus but we know that + + align:start position:0% +oh acids give h plus but we know that + + + align:start position:0% +oh acids give h plus but we know that +that's h3o plus + + align:start position:0% +that's h3o plus + + + align:start position:0% +that's h3o plus +okay we know that okay + + align:start position:0% +okay we know that okay + + + align:start position:0% +okay we know that okay +yeah but the thing is there's a + + align:start position:0% +yeah but the thing is there's a + + + align:start position:0% +yeah but the thing is there's a +dissolution reactions + + align:start position:0% +dissolution reactions + + + align:start position:0% +dissolution reactions +these things lead to really small + + align:start position:0% +these things lead to really small + + + align:start position:0% +these things lead to really small +concentrations + + align:start position:0% +concentrations + + + align:start position:0% +concentrations +and so soren sorensen + + align:start position:0% + + + + align:start position:0% + +that is a beer bottle by the way his + + align:start position:0% +that is a beer bottle by the way his + + + align:start position:0% +that is a beer bottle by the way his +research was funded by a beer company + + align:start position:0% +research was funded by a beer company + + + align:start position:0% +research was funded by a beer company +yeah and it was all about the taste of + + align:start position:0% +yeah and it was all about the taste of + + + align:start position:0% +yeah and it was all about the taste of +beer + + align:start position:0% +beer + + + align:start position:0% +beer +he called it looking at proteins + + align:start position:0% +he called it looking at proteins + + + align:start position:0% +he called it looking at proteins +but it was about beer and what he + + align:start position:0% +but it was about beer and what he + + + align:start position:0% +but it was about beer and what he +realized he's + + align:start position:0% +realized he's + + + align:start position:0% +realized he's +doing all these dissolution reactions of + + align:start position:0% +doing all these dissolution reactions of + + + align:start position:0% +doing all these dissolution reactions of +ions i think iranians was right yeah + + align:start position:0% +ions i think iranians was right yeah + + + align:start position:0% +ions i think iranians was right yeah +ions are really important + + align:start position:0% +ions are really important + + + align:start position:0% +ions are really important +uh and we're trying to measure these + + align:start position:0% +uh and we're trying to measure these + + + align:start position:0% +uh and we're trying to measure these +things and but i'm sick of all these + + align:start position:0% +things and but i'm sick of all these + + + align:start position:0% +things and but i'm sick of all these +zeroes + + align:start position:0% +zeroes + + + align:start position:0% +zeroes +i don't like writing .0001 or whatever + + align:start position:0% +i don't like writing .0001 or whatever + + + align:start position:0% +i don't like writing .0001 or whatever +all the time and and so look at that + + align:start position:0% +all the time and and so look at that + + + align:start position:0% +all the time and and so look at that +1.3 times 10 to the minus fifth that's + + align:start position:0% +1.3 times 10 to the minus fifth that's + + + align:start position:0% +1.3 times 10 to the minus fifth that's +not efficient + + align:start position:0% +not efficient + + + align:start position:0% +not efficient +and so what sorensen did is he talked + + align:start position:0% +and so what sorensen did is he talked + + + align:start position:0% +and so what sorensen did is he talked +about how + + align:start position:0% +about how + + + align:start position:0% +about how +you've got the power now what do i mean + + align:start position:0% +you've got the power now what do i mean + + + align:start position:0% +you've got the power now what do i mean +by power + + align:start position:0% +by power + + + align:start position:0% +by power +so many things right but if i look at h + + align:start position:0% +so many things right but if i look at h + + + align:start position:0% +so many things right but if i look at h +plus okay h3o plus + + align:start position:0% +plus okay h3o plus + + + align:start position:0% +plus okay h3o plus +and i say let's suppose the + + align:start position:0% +and i say let's suppose the + + + align:start position:0% +and i say let's suppose the +concentration is 0.0 + + align:start position:0% +concentration is 0.0 + + + align:start position:0% +concentration is 0.0 +oh boy zero zero zero zero one + + align:start position:0% +oh boy zero zero zero zero one + + + align:start position:0% +oh boy zero zero zero zero one +that's ten to the minus seventh + + align:start position:0% +that's ten to the minus seventh + + + align:start position:0% +that's ten to the minus seventh +because but but sorensen wasn't happy + + align:start position:0% +because but but sorensen wasn't happy + + + align:start position:0% +because but but sorensen wasn't happy +with that that's still + + align:start position:0% +with that that's still + + + align:start position:0% +with that that's still +you simplified it wait two four no it's + + align:start position:0% +you simplified it wait two four no it's + + + align:start position:0% +you simplified it wait two four no it's +not + + align:start position:0% +not + + + align:start position:0% +not +okay maybe it is now + + align:start position:0% + + + + align:start position:0% + +and he said well i ten to the minus + + align:start position:0% +and he said well i ten to the minus + + + align:start position:0% +and he said well i ten to the minus +seven there's still four characters i + + align:start position:0% +seven there's still four characters i + + + align:start position:0% +seven there's still four characters i +gotta write + + align:start position:0% +gotta write + + + align:start position:0% +gotta write +four so he went to the math department + + align:start position:0% +four so he went to the math department + + + align:start position:0% +four so he went to the math department +at his place and he said how do you what + + align:start position:0% +at his place and he said how do you what + + + align:start position:0% +at his place and he said how do you what +else could me + + align:start position:0% +else could me + + + align:start position:0% +else could me +i want to talk about the power of these + + align:start position:0% +i want to talk about the power of these + + + align:start position:0% +i want to talk about the power of these +ions and they're like + + align:start position:0% +ions and they're like + + + align:start position:0% +ions and they're like +power well that's the logarithm + + align:start position:0% +power well that's the logarithm + + + align:start position:0% +power well that's the logarithm +and and so if you take the log it's the + + align:start position:0% +and and so if you take the log it's the + + + align:start position:0% +and and so if you take the log it's the +power of hydrogen + + align:start position:0% +power of hydrogen + + + align:start position:0% +power of hydrogen +power of hydrogen + + align:start position:0% +power of hydrogen + + + align:start position:0% +power of hydrogen +is the ph and that's simply minus the + + align:start position:0% +is the ph and that's simply minus the + + + align:start position:0% +is the ph and that's simply minus the +law + + align:start position:0% +law + + + align:start position:0% +law +they didn't want negative numbers either + + align:start position:0% +they didn't want negative numbers either + + + align:start position:0% +they didn't want negative numbers either +oh but you can't have negative ph + + align:start position:0% +oh but you can't have negative ph + + + align:start position:0% +oh but you can't have negative ph +you can why because this is the + + align:start position:0% +you can why because this is the + + + align:start position:0% +you can why because this is the +definition + + align:start position:0% +definition + + + align:start position:0% +definition +of ph right or you could do poh since + + align:start position:0% +of ph right or you could do poh since + + + align:start position:0% +of ph right or you could do poh since +if you're going with arrhenius right so + + align:start position:0% +if you're going with arrhenius right so + + + align:start position:0% +if you're going with arrhenius right so +the power of + + align:start position:0% +the power of + + + align:start position:0% +the power of +hydrogen is the ph the poh would be + + align:start position:0% +hydrogen is the ph the poh would be + + + align:start position:0% +hydrogen is the ph the poh would be +minus log + + align:start position:0% +minus log + + + align:start position:0% +minus log +of the concentration of o h minus + + align:start position:0% +of the concentration of o h minus + + + align:start position:0% +of the concentration of o h minus +that's the poh but ph is the one that we + + align:start position:0% +that's the poh but ph is the one that we + + + align:start position:0% +that's the poh but ph is the one that we +most + + align:start position:0% +most + + + align:start position:0% +most +often see to describe + + align:start position:0% +often see to describe + + + align:start position:0% +often see to describe +whether something is acidic or basic + + align:start position:0% +whether something is acidic or basic + + + align:start position:0% +whether something is acidic or basic +right and so now you see well if the you + + align:start position:0% +right and so now you see well if the you + + + align:start position:0% +right and so now you see well if the you +know okay well this is a ph + + align:start position:0% +know okay well this is a ph + + + align:start position:0% +know okay well this is a ph +now this is easy right it's a ph of + + align:start position:0% +now this is easy right it's a ph of + + + align:start position:0% +now this is easy right it's a ph of +seven and and if the concentration were + + align:start position:0% +seven and and if the concentration were + + + align:start position:0% +seven and and if the concentration were +like + + align:start position:0% +like + + + align:start position:0% +like +point one it'd be a ph of one right + + align:start position:0% +point one it'd be a ph of one right + + + align:start position:0% +point one it'd be a ph of one right +minus + + align:start position:0% +minus + + + align:start position:0% +minus +log the power of hydrogen the law + + align:start position:0% +log the power of hydrogen the law + + + align:start position:0% +log the power of hydrogen the law +literally the log + + align:start position:0% +literally the log + + + align:start position:0% +literally the log +okay now if you look at scales of ph and + + align:start position:0% +okay now if you look at scales of ph and + + + align:start position:0% +okay now if you look at scales of ph and +it's a really fun thing to do + + align:start position:0% +it's a really fun thing to do + + + align:start position:0% +it's a really fun thing to do +then what you find is that usually + + align:start position:0% +then what you find is that usually + + + align:start position:0% +then what you find is that usually +almost always actually you'll see the + + align:start position:0% +almost always actually you'll see the + + + align:start position:0% +almost always actually you'll see the +scale ranging from 0 to 14. + + align:start position:0% +scale ranging from 0 to 14. + + + align:start position:0% +scale ranging from 0 to 14. +that's what sorensen originally decided + + align:start position:0% +that's what sorensen originally decided + + + align:start position:0% +that's what sorensen originally decided +i'm going to talk about these ions in + + align:start position:0% +i'm going to talk about these ions in + + + align:start position:0% +i'm going to talk about these ions in +solution + + align:start position:0% +solution + + + align:start position:0% +solution +i don't want to write it out every time + + align:start position:0% +i don't want to write it out every time + + + align:start position:0% +i don't want to write it out every time +i'm just going to have a simple scale + + align:start position:0% +i'm just going to have a simple scale + + + align:start position:0% +i'm just going to have a simple scale +we'll take the minus log and there you + + align:start position:0% +we'll take the minus log and there you + + + align:start position:0% +we'll take the minus log and there you +go yeah but + + align:start position:0% +go yeah but + + + align:start position:0% +go yeah but +you can see that if the if the + + align:start position:0% +you can see that if the if the + + + align:start position:0% +you can see that if the if the +concentration is more than one here + + align:start position:0% +concentration is more than one here + + + align:start position:0% +concentration is more than one here +then you could have negative ph's + + align:start position:0% +then you could have negative ph's + + + align:start position:0% +then you could have negative ph's +there's nothing special about zero here + + align:start position:0% +there's nothing special about zero here + + + align:start position:0% +there's nothing special about zero here +it just so happens that most things + + align:start position:0% +it just so happens that most things + + + align:start position:0% +it just so happens that most things +certainly that he was playing with at + + align:start position:0% +certainly that he was playing with at + + + align:start position:0% +certainly that he was playing with at +the time + + align:start position:0% +the time + + + align:start position:0% +the time +were in this scale and here's a few + + align:start position:0% +were in this scale and here's a few + + + align:start position:0% +were in this scale and here's a few +things that we know + + align:start position:0% +things that we know + + + align:start position:0% +things that we know +there it is right okay don't play with + + align:start position:0% +there it is right okay don't play with + + + align:start position:0% +there it is right okay don't play with +that one but play with lemon juice + + align:start position:0% +that one but play with lemon juice + + + align:start position:0% +that one but play with lemon juice +vinegar + + align:start position:0% +vinegar + + + align:start position:0% +vinegar +by the way vinegar okay wine is around + + align:start position:0% +by the way vinegar okay wine is around + + + align:start position:0% +by the way vinegar okay wine is around +three and a half + + align:start position:0% +three and a half + + + align:start position:0% +three and a half +vinegar is around two you know + + align:start position:0% +vinegar is around two you know + + + align:start position:0% +vinegar is around two you know +then the the word vinegar is + + align:start position:0% +then the the word vinegar is + + + align:start position:0% +then the the word vinegar is +von egar it's eager wine + + align:start position:0% +von egar it's eager wine + + + align:start position:0% +von egar it's eager wine +that's it right and but and it comes + + align:start position:0% +that's it right and but and it comes + + + align:start position:0% +that's it right and but and it comes +it's because of the the acidity + + align:start position:0% +it's because of the the acidity + + + align:start position:0% +it's because of the the acidity +the acidity well it's more than that but + + align:start position:0% +the acidity well it's more than that but + + + align:start position:0% +the acidity well it's more than that but +it's the acidity is changing + + align:start position:0% +it's the acidity is changing + + + align:start position:0% +it's the acidity is changing +by orders of magnitude power + + align:start position:0% +by orders of magnitude power + + + align:start position:0% +by orders of magnitude power +right and then you can go back and you + + align:start position:0% +right and then you can go back and you + + + align:start position:0% +right and then you can go back and you +say okay there's coffee i like that a + + align:start position:0% +say okay there's coffee i like that a + + + align:start position:0% +say okay there's coffee i like that a +lot and + + align:start position:0% +lot and + + + align:start position:0% +lot and +and blood + + align:start position:0% +and blood + + + align:start position:0% +and blood +by the way by the way talk about ocean + + align:start position:0% +by the way by the way talk about ocean + + + align:start position:0% +by the way by the way talk about ocean +acidity + + align:start position:0% +acidity + + + align:start position:0% +acidity +blood has a very narrow range of ph + + align:start position:0% +blood has a very narrow range of ph + + + align:start position:0% +blood has a very narrow range of ph +and if you change the ph of your blood + + align:start position:0% +and if you change the ph of your blood + + + align:start position:0% +and if you change the ph of your blood +by more than 0.2 + + align:start position:0% +by more than 0.2 + + + align:start position:0% +by more than 0.2 +it is very likely to lead to death right + + align:start position:0% +it is very likely to lead to death right + + + align:start position:0% +it is very likely to lead to death right +so just think about that's what we're + + align:start position:0% +so just think about that's what we're + + + align:start position:0% +so just think about that's what we're +doing to the ocean + + align:start position:0% +doing to the ocean + + + align:start position:0% +doing to the ocean +okay anyway that was an aside + + align:start position:0% +okay anyway that was an aside + + + align:start position:0% +okay anyway that was an aside +seawater oh ph 8.07 currently and + + align:start position:0% +seawater oh ph 8.07 currently and + + + align:start position:0% +seawater oh ph 8.07 currently and +dropping + + align:start position:0% +dropping + + + align:start position:0% +dropping +right uh okay baking soda so this is a + + align:start position:0% +right uh okay baking soda so this is a + + + align:start position:0% +right uh okay baking soda so this is a +very powerful no pun intended actually + + align:start position:0% +very powerful no pun intended actually + + + align:start position:0% +very powerful no pun intended actually +um + + align:start position:0% +um + + + align:start position:0% +um +uh now these are dissociation reactions + + align:start position:0% +uh now these are dissociation reactions + + + align:start position:0% +uh now these are dissociation reactions +these are dissolution reactions i'm + + align:start position:0% +these are dissolution reactions i'm + + + align:start position:0% +these are dissolution reactions i'm +taking an acid + + align:start position:0% +taking an acid + + + align:start position:0% +taking an acid +and i'm dissociating it in water + + align:start position:0% +and i'm dissociating it in water + + + align:start position:0% +and i'm dissociating it in water +and so you have equilibrium constants + + align:start position:0% +and so you have equilibrium constants + + + align:start position:0% +and so you have equilibrium constants +for that dissociation + + align:start position:0% +for that dissociation + + + align:start position:0% +for that dissociation +right and so and so if you if you go + + align:start position:0% +right and so and so if you if you go + + + align:start position:0% +right and so and so if you if you go +back to + + align:start position:0% +back to + + + align:start position:0% +back to +to that you know that's still going to + + align:start position:0% +to that you know that's still going to + + + align:start position:0% +to that you know that's still going to +matter here and that's + + align:start position:0% +matter here and that's + + + align:start position:0% +matter here and that's +going to be important in thinking about + + align:start position:0% +going to be important in thinking about + + + align:start position:0% +going to be important in thinking about +what an acid is because again why is it + + align:start position:0% +what an acid is because again why is it + + + align:start position:0% +what an acid is because again why is it +sick well because there's these protons + + align:start position:0% +sick well because there's these protons + + + align:start position:0% +sick well because there's these protons +well how many of them are there + + align:start position:0% +well how many of them are there + + + align:start position:0% +well how many of them are there +it depends on how it dissolved where did + + align:start position:0% +it depends on how it dissolved where did + + + align:start position:0% +it depends on how it dissolved where did +it find + + align:start position:0% +it find + + + align:start position:0% +it find +its equilibrium right and so for some of + + align:start position:0% +its equilibrium right and so for some of + + + align:start position:0% +its equilibrium right and so for some of +them like i just wrote + + align:start position:0% +them like i just wrote + + + align:start position:0% +them like i just wrote +you know we we just talked about + + align:start position:0% +you know we we just talked about + + + align:start position:0% +you know we we just talked about +hcl plus uh + + align:start position:0% +hcl plus uh + + + align:start position:0% +hcl plus uh +h2o that went to uh + + align:start position:0% +h2o that went to uh + + + align:start position:0% +h2o that went to uh +h3o plus plus + + align:start position:0% +h3o plus plus + + + align:start position:0% +h3o plus plus +uh cl minus okay now + + align:start position:0% + + + + align:start position:0% + +the thing is if i had if i had 0.1 + + align:start position:0% +the thing is if i had if i had 0.1 + + + align:start position:0% +the thing is if i had if i had 0.1 +moles per liter of hcl then + + align:start position:0% +moles per liter of hcl then + + + align:start position:0% +moles per liter of hcl then +it's going to lead to a concentration of + + align:start position:0% +it's going to lead to a concentration of + + + align:start position:0% +it's going to lead to a concentration of +h3o plus + + align:start position:0% +h3o plus + + + align:start position:0% +h3o plus +of around 0.1 moles per liter because + + align:start position:0% +of around 0.1 moles per liter because + + + align:start position:0% +of around 0.1 moles per liter because +it's + + align:start position:0% +it's + + + align:start position:0% +it's +nearly full nearly + + align:start position:0% +nearly full nearly + + + align:start position:0% +nearly full nearly +full dissociation + + align:start position:0% +full dissociation + + + align:start position:0% +full dissociation +what is what do i mean by that well i + + align:start position:0% +what is what do i mean by that well i + + + align:start position:0% +what is what do i mean by that well i +mean that yeah okay you know so you'll + + align:start position:0% +mean that yeah okay you know so you'll + + + align:start position:0% +mean that yeah okay you know so you'll +often see for + + align:start position:0% +often see for + + + align:start position:0% +often see for +like an acid like that one arrow + + align:start position:0% +like an acid like that one arrow + + + align:start position:0% +like an acid like that one arrow +well we know that in reality there's + + align:start position:0% +well we know that in reality there's + + + align:start position:0% +well we know that in reality there's +another arrow there + + align:start position:0% +another arrow there + + + align:start position:0% +another arrow there +but see here the acid dissociation + + align:start position:0% +but see here the acid dissociation + + + align:start position:0% +but see here the acid dissociation +constant + + align:start position:0% +constant + + + align:start position:0% +constant +is huge right so now we have a thing for + + align:start position:0% +is huge right so now we have a thing for + + + align:start position:0% +is huge right so now we have a thing for +the equilibrium + + align:start position:0% +the equilibrium + + + align:start position:0% +the equilibrium +of an acid which forms by dissociating + + align:start position:0% +of an acid which forms by dissociating + + + align:start position:0% +of an acid which forms by dissociating +the acid + + align:start position:0% +the acid + + + align:start position:0% +the acid +into its you know ions right and this + + align:start position:0% +into its you know ions right and this + + + align:start position:0% +into its you know ions right and this +is well for in this case it's 10 to the + + align:start position:0% +is well for in this case it's 10 to the + + + align:start position:0% +is well for in this case it's 10 to the +sixth + + align:start position:0% +sixth + + + align:start position:0% +sixth +it's enormous which means that the + + align:start position:0% +it's enormous which means that the + + + align:start position:0% +it's enormous which means that the +equilibrium lies + + align:start position:0% +equilibrium lies + + + align:start position:0% +equilibrium lies +very very very very far over and so + + align:start position:0% +very very very very far over and so + + + align:start position:0% +very very very very far over and so +oftentimes you'll see + + align:start position:0% +oftentimes you'll see + + + align:start position:0% +oftentimes you'll see +if it's going to strongly dissociate + + align:start position:0% +if it's going to strongly dissociate + + + align:start position:0% +if it's going to strongly dissociate +like sodium chloride did + + align:start position:0% +like sodium chloride did + + + align:start position:0% +like sodium chloride did +right then you'll sometimes see it + + align:start position:0% +right then you'll sometimes see it + + + align:start position:0% +right then you'll sometimes see it +written as just one arrow + + align:start position:0% +written as just one arrow + + + align:start position:0% +written as just one arrow +but there's a little bit going back as + + align:start position:0% +but there's a little bit going back as + + + align:start position:0% +but there's a little bit going back as +well right + + align:start position:0% +well right + + + align:start position:0% +well right +that is another equilibrium constant and + + align:start position:0% +that is another equilibrium constant and + + + align:start position:0% +that is another equilibrium constant and +we will talk about ka + + align:start position:0% +we will talk about ka + + + align:start position:0% +we will talk about ka +a little later and probably pick up on + + align:start position:0% +a little later and probably pick up on + + + align:start position:0% +a little later and probably pick up on +it next week + + align:start position:0% +it next week + + + align:start position:0% +it next week +okay now so near fold associated now + + align:start position:0% +okay now so near fold associated now + + + align:start position:0% +okay now so near fold associated now +the other thing that can happen that's + + align:start position:0% +the other thing that can happen that's + + + align:start position:0% +the other thing that can happen that's +important + + align:start position:0% +important + + + align:start position:0% +important +is water can do both and so there's + + align:start position:0% +is water can do both and so there's + + + align:start position:0% +is water can do both and so there's +there's uh let's see where should i go + + align:start position:0% +there's uh let's see where should i go + + + align:start position:0% +there's uh let's see where should i go +i'll go back over here + + align:start position:0% + + + + align:start position:0% + +so water + + align:start position:0% + + + + align:start position:0% + +see that picture there they got it wrong + + align:start position:0% +see that picture there they got it wrong + + + align:start position:0% +see that picture there they got it wrong +but it's okay they got it right because + + align:start position:0% +but it's okay they got it right because + + + align:start position:0% +but it's okay they got it right because +we all get along + + align:start position:0% +we all get along + + + align:start position:0% +we all get along +if you want to put h plus fine but you + + align:start position:0% +if you want to put h plus fine but you + + + align:start position:0% +if you want to put h plus fine but you +know that it's actually h3o plus okay + + align:start position:0% +know that it's actually h3o plus okay + + + align:start position:0% +know that it's actually h3o plus okay +good but you can put h plus no problem + + align:start position:0% +good but you can put h plus no problem + + + align:start position:0% +good but you can put h plus no problem +okay um now there it + + align:start position:0% +okay um now there it + + + align:start position:0% +okay um now there it +is and you can see that what water can + + align:start position:0% +is and you can see that what water can + + + align:start position:0% +is and you can see that what water can +do is it can do both + + align:start position:0% +do is it can do both + + + align:start position:0% +do is it can do both +and that turns out to be extremely + + align:start position:0% +and that turns out to be extremely + + + align:start position:0% +and that turns out to be extremely +important so if i take water + + align:start position:0% +important so if i take water + + + align:start position:0% +important so if i take water +and i mix it with water + + align:start position:0% +and i mix it with water + + + align:start position:0% +and i mix it with water +then you can get a combination of + + align:start position:0% +then you can get a combination of + + + align:start position:0% +then you can get a combination of +these ions + + align:start position:0% + + + + align:start position:0% + +oh plus a whole bunch of water + + align:start position:0% +oh plus a whole bunch of water + + + align:start position:0% +oh plus a whole bunch of water +so this would be like dissociation now + + align:start position:0% +so this would be like dissociation now + + + align:start position:0% +so this would be like dissociation now +there's a word for this + + align:start position:0% +there's a word for this + + + align:start position:0% +there's a word for this +water can turn into either + + align:start position:0% +water can turn into either + + + align:start position:0% +water can turn into either +it can it can be basic or acidic it can + + align:start position:0% +it can it can be basic or acidic it can + + + align:start position:0% +it can it can be basic or acidic it can +it can deliver o h minus + + align:start position:0% +it can deliver o h minus + + + align:start position:0% +it can deliver o h minus +or h3o plus right that's called auto + + align:start position:0% +or h3o plus right that's called auto + + + align:start position:0% +or h3o plus right that's called auto +ionization + + align:start position:0% +ionization + + + align:start position:0% +ionization +and it also has a special word water is + + align:start position:0% +and it also has a special word water is + + + align:start position:0% +and it also has a special word water is +called amphoteric + + align:start position:0% + + + + align:start position:0% + +amphoteric now that means + + align:start position:0% +amphoteric now that means + + + align:start position:0% +amphoteric now that means +that the same thing + + align:start position:0% + + + + align:start position:0% + +can be both + + align:start position:0% +can be both + + + align:start position:0% +can be both +both acid + + align:start position:0% +both acid + + + align:start position:0% +both acid +or a base + + align:start position:0% +or a base + + + align:start position:0% +or a base +it can act as either now so if you take + + align:start position:0% +it can act as either now so if you take + + + align:start position:0% +it can act as either now so if you take +pure water so let's see + + align:start position:0% +pure water so let's see + + + align:start position:0% +pure water so let's see +if i take pure water and + + align:start position:0% +if i take pure water and + + + align:start position:0% +if i take pure water and +oh + + align:start position:0% + + + + align:start position:0% + +and i look at the concentrations of + + align:start position:0% +and i look at the concentrations of + + + align:start position:0% +and i look at the concentrations of +these + + align:start position:0% +these + + + align:start position:0% +these +uh so atrial plus it's all happening + + align:start position:0% +uh so atrial plus it's all happening + + + align:start position:0% +uh so atrial plus it's all happening +from the water there's nothing in it i + + align:start position:0% +from the water there's nothing in it i + + + align:start position:0% +from the water there's nothing in it i +didn't add anything to it + + align:start position:0% +didn't add anything to it + + + align:start position:0% +didn't add anything to it +it's just pure water acetyl plus so that + + align:start position:0% +it's just pure water acetyl plus so that + + + align:start position:0% +it's just pure water acetyl plus so that +means that + + align:start position:0% +means that + + + align:start position:0% +means that +you know if that reaction happens it's + + align:start position:0% +you know if that reaction happens it's + + + align:start position:0% +you know if that reaction happens it's +going to generate + + align:start position:0% +going to generate + + + align:start position:0% +going to generate +you know the same number so the h3o plus + + align:start position:0% +you know the same number so the h3o plus + + + align:start position:0% +you know the same number so the h3o plus +would equal the concentration of the o h + + align:start position:0% +would equal the concentration of the o h + + + align:start position:0% +would equal the concentration of the o h +minus + + align:start position:0% +minus + + + align:start position:0% +minus +and in pure water that is a value + + align:start position:0% +and in pure water that is a value + + + align:start position:0% +and in pure water that is a value +that is equal to 1 times 10 to the minus + + align:start position:0% +that is equal to 1 times 10 to the minus + + + align:start position:0% +that is equal to 1 times 10 to the minus +7th + + align:start position:0% +7th + + + align:start position:0% +7th +moles per liter at + + align:start position:0% +moles per liter at + + + align:start position:0% +moles per liter at +25c okay + + align:start position:0% + + + + align:start position:0% + +at 25c and so now we have yet another + + align:start position:0% +at 25c and so now we have yet another + + + align:start position:0% +at 25c and so now we have yet another +that's neutral you can understand that + + align:start position:0% +that's neutral you can understand that + + + align:start position:0% +that's neutral you can understand that +that's neutral + + align:start position:0% +that's neutral + + + align:start position:0% +that's neutral +because because it you have the + + align:start position:0% +because because it you have the + + + align:start position:0% +because because it you have the +same you know if an acid is h plus or + + align:start position:0% +same you know if an acid is h plus or + + + align:start position:0% +same you know if an acid is h plus or +h3o plus in solution and a base is o h + + align:start position:0% +h3o plus in solution and a base is o h + + + align:start position:0% +h3o plus in solution and a base is o h +minus + + align:start position:0% +minus + + + align:start position:0% +minus +and i've made the same number right + + align:start position:0% +and i've made the same number right + + + align:start position:0% +and i've made the same number right +uh then they neutralize the acidity and + + align:start position:0% +uh then they neutralize the acidity and + + + align:start position:0% +uh then they neutralize the acidity and +basicity are neutralizing one another so + + align:start position:0% +basicity are neutralizing one another so + + + align:start position:0% +basicity are neutralizing one another so +that's neutral + + align:start position:0% +that's neutral + + + align:start position:0% +that's neutral +and in fact you can see that that's uh + + align:start position:0% +and in fact you can see that that's uh + + + align:start position:0% +and in fact you can see that that's uh +ph + + align:start position:0% +ph + + + align:start position:0% +ph +is seven oh and we can even write the + + align:start position:0% +is seven oh and we can even write the + + + align:start position:0% +is seven oh and we can even write the +equilibrium constant for water + + align:start position:0% +equilibrium constant for water + + + align:start position:0% +equilibrium constant for water +which is going to be those guys h3o + + align:start position:0% +which is going to be those guys h3o + + + align:start position:0% +which is going to be those guys h3o +minus times uh atrial plus times oh + + align:start position:0% +minus times uh atrial plus times oh + + + align:start position:0% +minus times uh atrial plus times oh +minus + + align:start position:0% +minus + + + align:start position:0% +minus +which is equal to 10 to the negative + + align:start position:0% +which is equal to 10 to the negative + + + align:start position:0% +which is equal to 10 to the negative +14th + + align:start position:0% +14th + + + align:start position:0% +14th +right because that's the dissociation + + align:start position:0% +right because that's the dissociation + + + align:start position:0% +right because that's the dissociation +reaction for water water plus water goes + + align:start position:0% +reaction for water water plus water goes + + + align:start position:0% +reaction for water water plus water goes +to those ions in solution + + align:start position:0% +to those ions in solution + + + align:start position:0% +to those ions in solution +we ignore the water right and then we're + + align:start position:0% +we ignore the water right and then we're + + + align:start position:0% +we ignore the water right and then we're +left with this + + align:start position:0% +left with this + + + align:start position:0% +left with this +same thing we've been doing okay 10 to + + align:start position:0% +same thing we've been doing okay 10 to + + + align:start position:0% +same thing we've been doing okay 10 to +the minus 14. + + align:start position:0% +the minus 14. + + + align:start position:0% +the minus 14. +now that takes us we neutral you know + + align:start position:0% +now that takes us we neutral you know + + + align:start position:0% +now that takes us we neutral you know +those are neutral + + align:start position:0% +those are neutral + + + align:start position:0% +those are neutral +and and and so speaking of of neutral + + align:start position:0% +and and and so speaking of of neutral + + + align:start position:0% +and and and so speaking of of neutral +that's where we're going to go next and + + align:start position:0% +that's where we're going to go next and + + + align:start position:0% +that's where we're going to go next and +uh + + align:start position:0% +uh + + + align:start position:0% +uh +i think what i want to do now is you + + align:start position:0% +i think what i want to do now is you + + + align:start position:0% +i think what i want to do now is you +know + + align:start position:0% +know + + + align:start position:0% +know +so we're going to go next into + + align:start position:0% +so we're going to go next into + + + align:start position:0% +so we're going to go next into +neutralizing things + + align:start position:0% +neutralizing things + + + align:start position:0% +neutralizing things +so like if you add an acid to a base or + + align:start position:0% +so like if you add an acid to a base or + + + align:start position:0% +so like if you add an acid to a base or +if you had a bastion acid + + align:start position:0% +if you had a bastion acid + + + align:start position:0% +if you had a bastion acid +and and we already said on monday you + + align:start position:0% +and and we already said on monday you + + + align:start position:0% +and and we already said on monday you +get salt and water um + + align:start position:0% +get salt and water um + + + align:start position:0% +get salt and water um +but see to understand that you need a + + align:start position:0% +but see to understand that you need a + + + align:start position:0% +but see to understand that you need a +different you need a broader definition + + align:start position:0% +different you need a broader definition + + + align:start position:0% +different you need a broader definition +cevante is amazing + + align:start position:0% +cevante is amazing + + + align:start position:0% +cevante is amazing +but zevante missed something and and so + + align:start position:0% +but zevante missed something and and so + + + align:start position:0% +but zevante missed something and and so +we need + + align:start position:0% +we need + + + align:start position:0% +we need +a different definition of acids and + + align:start position:0% +a different definition of acids and + + + align:start position:0% +a different definition of acids and +bases that's more general + + align:start position:0% +bases that's more general + + + align:start position:0% +bases that's more general +and that's what we're going to start + + align:start position:0% +and that's what we're going to start + + + align:start position:0% +and that's what we're going to start +with on monday but wait because + + align:start position:0% +with on monday but wait because + + + align:start position:0% +with on monday but wait because +this is a great place for me to work on + + align:start position:0% +this is a great place for me to work on + + + align:start position:0% +this is a great place for me to work on +my arm + + align:start position:0% + + + + align:start position:0% + +i gotta hit okay + + align:start position:0% +i gotta hit okay + + + align:start position:0% +i gotta hit okay +we're gonna go all the way up there and + + align:start position:0% +we're gonna go all the way up there and + + + align:start position:0% +we're gonna go all the way up there and +all the way up there + + align:start position:0% +all the way up there + + + align:start position:0% +all the way up there +and right there and right there and + + align:start position:0% +and right there and right there and + + + align:start position:0% +and right there and right there and +oh there and there and there + + align:start position:0% +oh there and there and there + + + align:start position:0% +oh there and there and there +and there oh that was excitement + + align:start position:0% +and there oh that was excitement + + + align:start position:0% +and there oh that was excitement +let's go back there in there okay + + align:start position:0% +let's go back there in there okay + + + align:start position:0% +let's go back there in there okay +and there oh that was the same direction + + align:start position:0% +and there oh that was the same direction + + + align:start position:0% +and there oh that was the same direction +there + + align:start position:0% +there + + + align:start position:0% +there +and there and there in the middle + + align:start position:0% +and there and there in the middle + + + align:start position:0% +and there and there in the middle +and there and there oh + + align:start position:0% +and there and there oh + + + align:start position:0% +and there and there oh +that was there and there + + align:start position:0% +that was there and there + + + align:start position:0% +that was there and there +and there and + + align:start position:0% +and there and + + + align:start position:0% +and there and +you guys are seeing i need i need a + + align:start position:0% +you guys are seeing i need i need a + + + align:start position:0% +you guys are seeing i need i need a +stronger arm here + + align:start position:0% +stronger arm here + + + align:start position:0% +stronger arm here +i can't really get too far and uh + + align:start position:0% + + + + align:start position:0% + +and oh that side is all in there + + align:start position:0% +and oh that side is all in there + + + align:start position:0% +and oh that side is all in there +and there and there + + align:start position:0% +and there and there + + + align:start position:0% +and there and there +and one more i'm going deep + + align:start position:0% + + + + align:start position:0% + +have a great thanksgiving everyone + + align:start position:0% +have a great thanksgiving everyone + + + align:start position:0% +have a great thanksgiving everyone +see you guys on monday + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/Zg6wQdMFO2c.txt b/Zg6wQdMFO2c.txt new file mode 100644 index 0000000000000000000000000000000000000000..1371ee1dd140fc9c836790f04637013ae5bc56f7 --- /dev/null +++ b/Zg6wQdMFO2c.txt @@ -0,0 +1,2491 @@ +align:start position:0% + +how do you design test and build a small + + align:start position:0% +how do you design test and build a small + + + align:start position:0% +how do you design test and build a small +and completely edible boat that propels + + align:start position:0% +and completely edible boat that propels + + + align:start position:0% +and completely edible boat that propels +itself through your cocktail this is a + + align:start position:0% +itself through your cocktail this is a + + + align:start position:0% +itself through your cocktail this is a +complicated problem but it and many + + align:start position:0% +complicated problem but it and many + + + align:start position:0% +complicated problem but it and many +other problems like it can be solved by + + align:start position:0% +other problems like it can be solved by + + + align:start position:0% +other problems like it can be solved by +systematically breaking those problems + + align:start position:0% +systematically breaking those problems + + + align:start position:0% +systematically breaking those problems +down in this video we'll explore how to + + align:start position:0% +down in this video we'll explore how to + + + align:start position:0% +down in this video we'll explore how to +MIT graduate students created these + + align:start position:0% +MIT graduate students created these + + + align:start position:0% +MIT graduate students created these +cocktail cruisers + + align:start position:0% +cocktail cruisers + + + align:start position:0% +cocktail cruisers +this video is part of the + + align:start position:0% +this video is part of the + + + align:start position:0% +this video is part of the +problem-solving video series + + align:start position:0% +problem-solving video series + + + align:start position:0% +problem-solving video series +problem-solving skills in combination + + align:start position:0% +problem-solving skills in combination + + + align:start position:0% +problem-solving skills in combination +with an understanding of the natural and + + align:start position:0% +with an understanding of the natural and + + + align:start position:0% +with an understanding of the natural and +human-made world are critical to the + + align:start position:0% +human-made world are critical to the + + + align:start position:0% +human-made world are critical to the +design and optimization of systems and + + align:start position:0% +design and optimization of systems and + + + align:start position:0% +design and optimization of systems and +processes hi my name is Lisa Burton and + + align:start position:0% +processes hi my name is Lisa Burton and + + + align:start position:0% +processes hi my name is Lisa Burton and +I'm Nadia Chang we are graduate students + + align:start position:0% +I'm Nadia Chang we are graduate students + + + align:start position:0% +I'm Nadia Chang we are graduate students +in Pecola's soy's lab in the department + + align:start position:0% +in Pecola's soy's lab in the department + + + align:start position:0% +in Pecola's soy's lab in the department +of mechanical engineering at MIT today + + align:start position:0% +of mechanical engineering at MIT today + + + align:start position:0% +of mechanical engineering at MIT today +we're going to tell you about a class + + align:start position:0% +we're going to tell you about a class + + + align:start position:0% +we're going to tell you about a class +project that we worked on that turn into + + align:start position:0% +project that we worked on that turn into + + + align:start position:0% +project that we worked on that turn into +a product called cocktail cruisers after + + align:start position:0% +a product called cocktail cruisers after + + + align:start position:0% +a product called cocktail cruisers after +watching this video you should be able + + align:start position:0% +watching this video you should be able + + + align:start position:0% +watching this video you should be able +to identify the steps of the + + align:start position:0% +to identify the steps of the + + + align:start position:0% +to identify the steps of the +problem-solving process and recognize + + align:start position:0% +problem-solving process and recognize + + + align:start position:0% +problem-solving process and recognize +that the problem-solving process is + + align:start position:0% +that the problem-solving process is + + + align:start position:0% +that the problem-solving process is +iterative take a moment to think about + + align:start position:0% +iterative take a moment to think about + + + align:start position:0% +iterative take a moment to think about +your approach to problem-solving what + + align:start position:0% +your approach to problem-solving what + + + align:start position:0% +your approach to problem-solving what +steps do you generally go through please + + align:start position:0% +steps do you generally go through please + + + align:start position:0% +steps do you generally go through please +pause the video and take a moment to + + align:start position:0% +pause the video and take a moment to + + + align:start position:0% +pause the video and take a moment to +think about it then continue playing the + + align:start position:0% +think about it then continue playing the + + + align:start position:0% +think about it then continue playing the +video to hear about one approach while + + align:start position:0% +video to hear about one approach while + + + align:start position:0% +video to hear about one approach while +different people might approach a + + align:start position:0% +different people might approach a + + + align:start position:0% +different people might approach a +problem in different ways using an + + align:start position:0% +problem in different ways using an + + + align:start position:0% +problem in different ways using an +explicit strategy for problem-solving + + align:start position:0% +explicit strategy for problem-solving + + + align:start position:0% +explicit strategy for problem-solving +can be very helpful you can find + + align:start position:0% +can be very helpful you can find + + + align:start position:0% +can be very helpful you can find +different problem-solving strategies in + + align:start position:0% +different problem-solving strategies in + + + align:start position:0% +different problem-solving strategies in +the literature the strategy that we will + + align:start position:0% +the literature the strategy that we will + + + align:start position:0% +the literature the strategy that we will +present in this video is adapted from + + align:start position:0% +present in this video is adapted from + + + align:start position:0% +present in this video is adapted from +dawn Woods and Phil Blanc at the first + + align:start position:0% +dawn Woods and Phil Blanc at the first + + + align:start position:0% +dawn Woods and Phil Blanc at the first +step is to define the problem what are + + align:start position:0% +step is to define the problem what are + + + align:start position:0% +step is to define the problem what are +the criteria what are the constraints + + align:start position:0% +the criteria what are the constraints + + + align:start position:0% +the criteria what are the constraints +after defining the problem you need to + + align:start position:0% +after defining the problem you need to + + + align:start position:0% +after defining the problem you need to +gather information what are the knowns + + align:start position:0% +gather information what are the knowns + + + align:start position:0% +gather information what are the knowns +and unknowns what content knowledge is + + align:start position:0% +and unknowns what content knowledge is + + + align:start position:0% +and unknowns what content knowledge is +needed to solve the problem have others + + align:start position:0% +needed to solve the problem have others + + + align:start position:0% +needed to solve the problem have others +worked on a similar problem before the + + align:start position:0% +worked on a similar problem before the + + + align:start position:0% +worked on a similar problem before the +next step is to explore look at the + + align:start position:0% +next step is to explore look at the + + + align:start position:0% +next step is to explore look at the +problem in different ways brainstorm + + align:start position:0% +problem in different ways brainstorm + + + align:start position:0% +problem in different ways brainstorm +different approaches to meeting the + + align:start position:0% +different approaches to meeting the + + + align:start position:0% +different approaches to meeting the +criteria given the constraints after + + align:start position:0% +criteria given the constraints after + + + align:start position:0% +criteria given the constraints after +exploring you need to pick one approach + + align:start position:0% +exploring you need to pick one approach + + + align:start position:0% +exploring you need to pick one approach +to solving your problem and plan your + + align:start position:0% +to solving your problem and plan your + + + align:start position:0% +to solving your problem and plan your +strategy determine the resources needed + + align:start position:0% +strategy determine the resources needed + + + align:start position:0% +strategy determine the resources needed +to carry out your plan a flowchart + + align:start position:0% +to carry out your plan a flowchart + + + align:start position:0% +to carry out your plan a flowchart +outline or schematic might be useful + + align:start position:0% +outline or schematic might be useful + + + align:start position:0% +outline or schematic might be useful +after the planning phase it is time to + + align:start position:0% +after the planning phase it is time to + + + align:start position:0% +after the planning phase it is time to +act in this step you follow your plan to + + align:start position:0% +act in this step you follow your plan to + + + align:start position:0% +act in this step you follow your plan to +create your solution + + align:start position:0% +create your solution + + + align:start position:0% +create your solution +once you have a solution you need to + + align:start position:0% +once you have a solution you need to + + + align:start position:0% +once you have a solution you need to +check it does it make sense does it meet + + align:start position:0% +check it does it make sense does it meet + + + align:start position:0% +check it does it make sense does it meet +the criteria where does it fall short is + + align:start position:0% +the criteria where does it fall short is + + + align:start position:0% +the criteria where does it fall short is +any troubleshooting required if the + + align:start position:0% +any troubleshooting required if the + + + align:start position:0% +any troubleshooting required if the +solution isn't satisfactory it might be + + align:start position:0% +solution isn't satisfactory it might be + + + align:start position:0% +solution isn't satisfactory it might be +necessary to explore some more and + + align:start position:0% +necessary to explore some more and + + + align:start position:0% +necessary to explore some more and +create a new plan once you have your + + align:start position:0% +create a new plan once you have your + + + align:start position:0% +create a new plan once you have your +final solution what have you learned + + align:start position:0% +final solution what have you learned + + + align:start position:0% +final solution what have you learned +that can be generalized to other + + align:start position:0% +that can be generalized to other + + + align:start position:0% +that can be generalized to other +contexts finally disseminate your + + align:start position:0% +contexts finally disseminate your + + + align:start position:0% +contexts finally disseminate your +results so that others can learn from + + align:start position:0% +results so that others can learn from + + + align:start position:0% +results so that others can learn from +your solution this could be through a + + align:start position:0% +your solution this could be through a + + + align:start position:0% +your solution this could be through a +class discussion a formal presentation + + align:start position:0% +class discussion a formal presentation + + + align:start position:0% +class discussion a formal presentation +or a scientific paper now that you are + + align:start position:0% +or a scientific paper now that you are + + + align:start position:0% +or a scientific paper now that you are +familiar with the problem-solving + + align:start position:0% +familiar with the problem-solving + + + align:start position:0% +familiar with the problem-solving +process see if you can identify where I + + align:start position:0% +process see if you can identify where I + + + align:start position:0% +process see if you can identify where I +use these steps as I worked on a class + + align:start position:0% +use these steps as I worked on a class + + + align:start position:0% +use these steps as I worked on a class +project this project began in my fluid + + align:start position:0% +project this project began in my fluid + + + align:start position:0% +project this project began in my fluid +dynamics class which focused on + + align:start position:0% +dynamics class which focused on + + + align:start position:0% +dynamics class which focused on +interfacial phenomena and was taught by + + align:start position:0% +interfacial phenomena and was taught by + + + align:start position:0% +interfacial phenomena and was taught by +my other adviser professor John Bush the + + align:start position:0% +my other adviser professor John Bush the + + + align:start position:0% +my other adviser professor John Bush the +main criterion or requirement for the + + align:start position:0% +main criterion or requirement for the + + + align:start position:0% +main criterion or requirement for the +project was to conduct an experiment + + align:start position:0% +project was to conduct an experiment + + + align:start position:0% +project was to conduct an experiment +perform a simulation or design a product + + align:start position:0% +perform a simulation or design a product + + + align:start position:0% +perform a simulation or design a product +fundamentally based on a topic covered + + align:start position:0% +fundamentally based on a topic covered + + + align:start position:0% +fundamentally based on a topic covered +in class there were also some + + align:start position:0% +in class there were also some + + + align:start position:0% +in class there were also some +constraints placed on the project we + + align:start position:0% +constraints placed on the project we + + + align:start position:0% +constraints placed on the project we +only had three months to work on it in a + + align:start position:0% +only had three months to work on it in a + + + align:start position:0% +only had three months to work on it in a +limited budget other than that it was + + align:start position:0% +limited budget other than that it was + + + align:start position:0% +limited budget other than that it was +very open-ended it was really up to me + + align:start position:0% +very open-ended it was really up to me + + + align:start position:0% +very open-ended it was really up to me +to define the problem from there + + align:start position:0% +to define the problem from there + + + align:start position:0% +to define the problem from there +learning about the Marangoni effect + + align:start position:0% +learning about the Marangoni effect + + + align:start position:0% +learning about the Marangoni effect +inspired my design + + align:start position:0% +inspired my design + + + align:start position:0% +inspired my design +the Marangoni effect arises from a + + align:start position:0% +the Marangoni effect arises from a + + + align:start position:0% +the Marangoni effect arises from a +gradient or difference in surface + + align:start position:0% +gradient or difference in surface + + + align:start position:0% +gradient or difference in surface +tension we can see the Marangoni effect + + align:start position:0% +tension we can see the Marangoni effect + + + align:start position:0% +tension we can see the Marangoni effect +by adding a drop of soap solution to a + + align:start position:0% +by adding a drop of soap solution to a + + + align:start position:0% +by adding a drop of soap solution to a +container of water the soap solution + + align:start position:0% +container of water the soap solution + + + align:start position:0% +container of water the soap solution +reduces the surface tension of the water + + align:start position:0% +reduces the surface tension of the water + + + align:start position:0% +reduces the surface tension of the water +locally causing flow using black pepper + + align:start position:0% +locally causing flow using black pepper + + + align:start position:0% +locally causing flow using black pepper +flakes as a tracer we can visualize the + + align:start position:0% +flakes as a tracer we can visualize the + + + align:start position:0% +flakes as a tracer we can visualize the +flow away from the area of low surface + + align:start position:0% +flow away from the area of low surface + + + align:start position:0% +flow away from the area of low surface +tension surface tension is simply a + + align:start position:0% +tension surface tension is simply a + + + align:start position:0% +tension surface tension is simply a +property of liquid that results from + + align:start position:0% +property of liquid that results from + + + align:start position:0% +property of liquid that results from +intermolecular forces in the bulk of a + + align:start position:0% +intermolecular forces in the bulk of a + + + align:start position:0% +intermolecular forces in the bulk of a +uniform liquid each molecule experience + + align:start position:0% +uniform liquid each molecule experience + + + align:start position:0% +uniform liquid each molecule experience +is a zero net force because molecules + + align:start position:0% +is a zero net force because molecules + + + align:start position:0% +is a zero net force because molecules +that exert equivalent force on each + + align:start position:0% +that exert equivalent force on each + + + align:start position:0% +that exert equivalent force on each +other surrounded at the surface of a + + align:start position:0% +other surrounded at the surface of a + + + align:start position:0% +other surrounded at the surface of a +liquid molecules from the liquid + + align:start position:0% +liquid molecules from the liquid + + + align:start position:0% +liquid molecules from the liquid +experience a nonzero net force pulling + + align:start position:0% +experience a nonzero net force pulling + + + align:start position:0% +experience a nonzero net force pulling +them toward the bulk of the fluid + + align:start position:0% +them toward the bulk of the fluid + + + align:start position:0% +them toward the bulk of the fluid +because they are not completely + + align:start position:0% +because they are not completely + + + align:start position:0% +because they are not completely +surrounded by like molecules this causes + + align:start position:0% +surrounded by like molecules this causes + + + align:start position:0% +surrounded by like molecules this causes +the surface to minimize its area the + + align:start position:0% +the surface to minimize its area the + + + align:start position:0% +the surface to minimize its area the +high surface tension of water allows + + align:start position:0% +high surface tension of water allows + + + align:start position:0% +high surface tension of water allows +objects denser than water such as a + + align:start position:0% +objects denser than water such as a + + + align:start position:0% +objects denser than water such as a +paper clip or + + align:start position:0% +paper clip or + + + align:start position:0% +paper clip or +water Strider to float on the surface if + + align:start position:0% +water Strider to float on the surface if + + + align:start position:0% +water Strider to float on the surface if +an object has a high surface tension + + align:start position:0% +an object has a high surface tension + + + align:start position:0% +an object has a high surface tension +liquid on one side of it and a low + + align:start position:0% +liquid on one side of it and a low + + + align:start position:0% +liquid on one side of it and a low +surface tension liquid on the other side + + align:start position:0% +surface tension liquid on the other side + + + align:start position:0% +surface tension liquid on the other side +the difference in surface tension will + + align:start position:0% +the difference in surface tension will + + + align:start position:0% +the difference in surface tension will +cause the object to move toward the high + + align:start position:0% +cause the object to move toward the high + + + align:start position:0% +cause the object to move toward the high +surface tension liquid we can see that + + align:start position:0% +surface tension liquid we can see that + + + align:start position:0% +surface tension liquid we can see that +happen in this demonstration of a + + align:start position:0% +happen in this demonstration of a + + + align:start position:0% +happen in this demonstration of a +toothpick floating on water if we add a + + align:start position:0% +toothpick floating on water if we add a + + + align:start position:0% +toothpick floating on water if we add a +few drops of soapy water to one side of + + align:start position:0% +few drops of soapy water to one side of + + + align:start position:0% +few drops of soapy water to one side of +the toothpick the toothpick moves away I + + align:start position:0% +the toothpick the toothpick moves away I + + + align:start position:0% +the toothpick the toothpick moves away I +decided that I wanted to make a + + align:start position:0% +decided that I wanted to make a + + + align:start position:0% +decided that I wanted to make a +miniature boat that would be propelled + + align:start position:0% +miniature boat that would be propelled + + + align:start position:0% +miniature boat that would be propelled +by a surface tension gradient I wanted + + align:start position:0% +by a surface tension gradient I wanted + + + align:start position:0% +by a surface tension gradient I wanted +to propel the boat in a water-based + + align:start position:0% +to propel the boat in a water-based + + + align:start position:0% +to propel the boat in a water-based +environment with the ultimate goal of + + align:start position:0% +environment with the ultimate goal of + + + align:start position:0% +environment with the ultimate goal of +using it in a food setting this required + + align:start position:0% +using it in a food setting this required + + + align:start position:0% +using it in a food setting this required +that the second liquid be safe to eat + + align:start position:0% +that the second liquid be safe to eat + + + align:start position:0% +that the second liquid be safe to eat +since it would mix with the water at + + align:start position:0% +since it would mix with the water at + + + align:start position:0% +since it would mix with the water at +this point I wasn't concerned with + + align:start position:0% +this point I wasn't concerned with + + + align:start position:0% +this point I wasn't concerned with +making the boat edible because it could + + align:start position:0% +making the boat edible because it could + + + align:start position:0% +making the boat edible because it could +simply be removed by hand from the food + + align:start position:0% +simply be removed by hand from the food + + + align:start position:0% +simply be removed by hand from the food +therefore the problem we needed to solve + + align:start position:0% +therefore the problem we needed to solve + + + align:start position:0% +therefore the problem we needed to solve +was how to design a boat that could be + + align:start position:0% +was how to design a boat that could be + + + align:start position:0% +was how to design a boat that could be +propelled by the Marangoni effect + + align:start position:0% +propelled by the Marangoni effect + + + align:start position:0% +propelled by the Marangoni effect +this included the identification of a + + align:start position:0% +this included the identification of a + + + align:start position:0% +this included the identification of a +liquid that was edible and had the + + align:start position:0% +liquid that was edible and had the + + + align:start position:0% +liquid that was edible and had the +appropriate surface tension for use as + + align:start position:0% +appropriate surface tension for use as + + + align:start position:0% +appropriate surface tension for use as +the propellant I started gathering + + align:start position:0% +the propellant I started gathering + + + align:start position:0% +the propellant I started gathering +information about different fluids that + + align:start position:0% +information about different fluids that + + + align:start position:0% +information about different fluids that +had a lower surface tension than water I + + align:start position:0% +had a lower surface tension than water I + + + align:start position:0% +had a lower surface tension than water I +also looked at the existing designs of + + align:start position:0% +also looked at the existing designs of + + + align:start position:0% +also looked at the existing designs of +other boats noting what propellants they + + align:start position:0% +other boats noting what propellants they + + + align:start position:0% +other boats noting what propellants they +used in their method for releasing the + + align:start position:0% +used in their method for releasing the + + + align:start position:0% +used in their method for releasing the +propellant into the surrounding water to + + align:start position:0% +propellant into the surrounding water to + + + align:start position:0% +propellant into the surrounding water to +identify important physical features of + + align:start position:0% +identify important physical features of + + + align:start position:0% +identify important physical features of +the boat I did some calculations + + align:start position:0% +the boat I did some calculations + + + align:start position:0% +the boat I did some calculations +starting with a simple force balance + + align:start position:0% +starting with a simple force balance + + + align:start position:0% +starting with a simple force balance +diagram we can represent the boat as a + + align:start position:0% +diagram we can represent the boat as a + + + align:start position:0% +diagram we can represent the boat as a +rectangular prism for now viewing the + + align:start position:0% +rectangular prism for now viewing the + + + align:start position:0% +rectangular prism for now viewing the +boat from the side we see just a + + align:start position:0% +boat from the side we see just a + + + align:start position:0% +boat from the side we see just a +rectangle in the vertical direction the + + align:start position:0% +rectangle in the vertical direction the + + + align:start position:0% +rectangle in the vertical direction the +forces acting on the boat are the force + + align:start position:0% +forces acting on the boat are the force + + + align:start position:0% +forces acting on the boat are the force +due to gravity or the weight of the boat + + align:start position:0% +due to gravity or the weight of the boat + + + align:start position:0% +due to gravity or the weight of the boat +and the buoyancy force which is + + align:start position:0% +and the buoyancy force which is + + + align:start position:0% +and the buoyancy force which is +equivalent to the weight of the water + + align:start position:0% +equivalent to the weight of the water + + + align:start position:0% +equivalent to the weight of the water +displaced by the boat and the meniscus + + align:start position:0% +displaced by the boat and the meniscus + + + align:start position:0% +displaced by the boat and the meniscus +you've probably noticed that water in + + align:start position:0% +you've probably noticed that water in + + + align:start position:0% +you've probably noticed that water in +your drinking glass slightly climbs up + + align:start position:0% +your drinking glass slightly climbs up + + + align:start position:0% +your drinking glass slightly climbs up +the wall of the glass this is the + + align:start position:0% +the wall of the glass this is the + + + align:start position:0% +the wall of the glass this is the +meniscus then it depends on the material + + align:start position:0% +meniscus then it depends on the material + + + align:start position:0% +meniscus then it depends on the material +of the object for instance the boat or + + align:start position:0% +of the object for instance the boat or + + + align:start position:0% +of the object for instance the boat or +the glass the liquid and the gas in our + + align:start position:0% +the glass the liquid and the gas in our + + + align:start position:0% +the glass the liquid and the gas in our +case air therefore to make the boat + + align:start position:0% +case air therefore to make the boat + + + align:start position:0% +case air therefore to make the boat +float we must ensure that the weight of + + align:start position:0% +float we must ensure that the weight of + + + align:start position:0% +float we must ensure that the weight of +the water displaced balances the weight + + align:start position:0% +the water displaced balances the weight + + + align:start position:0% +the water displaced balances the weight +of the boat this is Archimedes principle + + align:start position:0% +of the boat this is Archimedes principle + + + align:start position:0% +of the boat this is Archimedes principle +in the horizontal direction we have the + + align:start position:0% +in the horizontal direction we have the + + + align:start position:0% +in the horizontal direction we have the +force of surface tension of the fuel on + + align:start position:0% +force of surface tension of the fuel on + + + align:start position:0% +force of surface tension of the fuel on +the left side and the force of surface + + align:start position:0% +the left side and the force of surface + + + align:start position:0% +the left side and the force of surface +tension of the surrounding fluid which + + align:start position:0% +tension of the surrounding fluid which + + + align:start position:0% +tension of the surrounding fluid which +we will assume as + + align:start position:0% +we will assume as + + + align:start position:0% +we will assume as +if the forces aren't equal the boat must + + align:start position:0% +if the forces aren't equal the boat must + + + align:start position:0% +if the forces aren't equal the boat must +accelerate according to Newton's laws + + align:start position:0% +accelerate according to Newton's laws + + + align:start position:0% +accelerate according to Newton's laws +therefore to make the boat move faster + + align:start position:0% +therefore to make the boat move faster + + + align:start position:0% +therefore to make the boat move faster +we want the difference in surface + + align:start position:0% +we want the difference in surface + + + align:start position:0% +we want the difference in surface +stitching to be as great as possible + + align:start position:0% +stitching to be as great as possible + + + align:start position:0% +stitching to be as great as possible +once the boat is moving drag becomes + + align:start position:0% +once the boat is moving drag becomes + + + align:start position:0% +once the boat is moving drag becomes +important drag opposes the direction of + + align:start position:0% +important drag opposes the direction of + + + align:start position:0% +important drag opposes the direction of +motion and increase with velocity and + + align:start position:0% +motion and increase with velocity and + + + align:start position:0% +motion and increase with velocity and +the cross sectional area of the boat a + + align:start position:0% +the cross sectional area of the boat a + + + align:start position:0% +the cross sectional area of the boat a +smaller cross-sectional area will allow + + align:start position:0% +smaller cross-sectional area will allow + + + align:start position:0% +smaller cross-sectional area will allow +the boat to move faster to ensure that + + align:start position:0% +the boat to move faster to ensure that + + + align:start position:0% +the boat to move faster to ensure that +the boat remains stable the center of + + align:start position:0% +the boat remains stable the center of + + + align:start position:0% +the boat remains stable the center of +mass must be below the center of + + align:start position:0% +mass must be below the center of + + + align:start position:0% +mass must be below the center of +buoyancy otherwise the boat will tip + + align:start position:0% +buoyancy otherwise the boat will tip + + + align:start position:0% +buoyancy otherwise the boat will tip +over and sink as I explore different + + align:start position:0% +over and sink as I explore different + + + align:start position:0% +over and sink as I explore different +ideas it became clear that I needed to + + align:start position:0% +ideas it became clear that I needed to + + + align:start position:0% +ideas it became clear that I needed to +do some testing to find an edible low + + align:start position:0% +do some testing to find an edible low + + + align:start position:0% +do some testing to find an edible low +surface tension liquid to act as the + + align:start position:0% +surface tension liquid to act as the + + + align:start position:0% +surface tension liquid to act as the +boats fuel I tested different liquids I + + align:start position:0% +boats fuel I tested different liquids I + + + align:start position:0% +boats fuel I tested different liquids I +found in my kitchen from hot sauce to + + align:start position:0% +found in my kitchen from hot sauce to + + + align:start position:0% +found in my kitchen from hot sauce to +sugar water to vinegar from these tests + + align:start position:0% +sugar water to vinegar from these tests + + + align:start position:0% +sugar water to vinegar from these tests +I decided that I needed a low surface + + align:start position:0% +I decided that I needed a low surface + + + align:start position:0% +I decided that I needed a low surface +tension liquid that was also volatile or + + align:start position:0% +tension liquid that was also volatile or + + + align:start position:0% +tension liquid that was also volatile or +evaporative this is necessary for the + + align:start position:0% +evaporative this is necessary for the + + + align:start position:0% +evaporative this is necessary for the +boat to continue to move otherwise the + + align:start position:0% +boat to continue to move otherwise the + + + align:start position:0% +boat to continue to move otherwise the +fuel surrounds the boat equally on all + + align:start position:0% +fuel surrounds the boat equally on all + + + align:start position:0% +fuel surrounds the boat equally on all +sides so that no surface tension + + align:start position:0% +sides so that no surface tension + + + align:start position:0% +sides so that no surface tension +gradient exists and therefore the boat + + align:start position:0% +gradient exists and therefore the boat + + + align:start position:0% +gradient exists and therefore the boat +does not move the best fuel I found was + + align:start position:0% +does not move the best fuel I found was + + + align:start position:0% +does not move the best fuel I found was +liquor the alcohol content of liquor and + + align:start position:0% +liquor the alcohol content of liquor and + + + align:start position:0% +liquor the alcohol content of liquor and +the surface tension are inversely + + align:start position:0% +the surface tension are inversely + + + align:start position:0% +the surface tension are inversely +related + + align:start position:0% +related + + + align:start position:0% +related +therefore using a very high alcohol + + align:start position:0% +therefore using a very high alcohol + + + align:start position:0% +therefore using a very high alcohol +content liquor will result in a faster + + align:start position:0% +content liquor will result in a faster + + + align:start position:0% +content liquor will result in a faster +boat I started sketching ideas for what + + align:start position:0% +boat I started sketching ideas for what + + + align:start position:0% +boat I started sketching ideas for what +the boats might look like drawing on + + align:start position:0% +the boats might look like drawing on + + + align:start position:0% +the boats might look like drawing on +previous research the initial design had + + align:start position:0% +previous research the initial design had + + + align:start position:0% +previous research the initial design had +an open fuel reservoir in the middle of + + align:start position:0% +an open fuel reservoir in the middle of + + + align:start position:0% +an open fuel reservoir in the middle of +the boat with a small slit that allows + + align:start position:0% +the boat with a small slit that allows + + + align:start position:0% +the boat with a small slit that allows +the liquid to leave the reservoir the + + align:start position:0% +the liquid to leave the reservoir the + + + align:start position:0% +the liquid to leave the reservoir the +overall shape was a very simple boat + + align:start position:0% +overall shape was a very simple boat + + + align:start position:0% +overall shape was a very simple boat +shape after testing materials for a + + align:start position:0% +shape after testing materials for a + + + align:start position:0% +shape after testing materials for a +while it was time to come up with a plan + + align:start position:0% +while it was time to come up with a plan + + + align:start position:0% +while it was time to come up with a plan +I decided that I needed to create a + + align:start position:0% +I decided that I needed to create a + + + align:start position:0% +I decided that I needed to create a +prototype so I enlisted the help of my + + align:start position:0% +prototype so I enlisted the help of my + + + align:start position:0% +prototype so I enlisted the help of my +lab mate Nadia she suggested using a 3d + + align:start position:0% +lab mate Nadia she suggested using a 3d + + + align:start position:0% +lab mate Nadia she suggested using a 3d +printer to create the boat in the + + align:start position:0% +printer to create the boat in the + + + align:start position:0% +printer to create the boat in the +Edgerton Center student shop the only + + align:start position:0% +Edgerton Center student shop the only + + + align:start position:0% +Edgerton Center student shop the only +way we were really going to know if the + + align:start position:0% +way we were really going to know if the + + + align:start position:0% +way we were really going to know if the +boat design was going to work was to + + align:start position:0% +boat design was going to work was to + + + align:start position:0% +boat design was going to work was to +actually try it it was time to act and + + align:start position:0% +actually try it it was time to act and + + + align:start position:0% +actually try it it was time to act and +having a rapid prototyping technology + + align:start position:0% +having a rapid prototyping technology + + + align:start position:0% +having a rapid prototyping technology +such as 3d printers available + + align:start position:0% +such as 3d printers available + + + align:start position:0% +such as 3d printers available +significantly expedites the testing and + + align:start position:0% +significantly expedites the testing and + + + align:start position:0% +significantly expedites the testing and +iteration process the 3d printer + + align:start position:0% +iteration process the 3d printer + + + align:start position:0% +iteration process the 3d printer +requires that we develop 3d + + align:start position:0% +requires that we develop 3d + + + align:start position:0% +requires that we develop 3d +representations of our boat design and + + align:start position:0% +representations of our boat design and + + + align:start position:0% +representations of our boat design and +there are various types of 3d printing + + align:start position:0% +there are various types of 3d printing + + + align:start position:0% +there are various types of 3d printing +technologies the one we used utilizes + + align:start position:0% +technologies the one we used utilizes + + + align:start position:0% +technologies the one we used utilizes +fused deposition modeling or FDM the way + + align:start position:0% +fused deposition modeling or FDM the way + + + align:start position:0% +fused deposition modeling or FDM the way +it works is that there is a spool of + + align:start position:0% +it works is that there is a spool of + + + align:start position:0% +it works is that there is a spool of +thin plastic thread that is fed through + + align:start position:0% +thin plastic thread that is fed through + + + align:start position:0% +thin plastic thread that is fed through +a nozzle the nozzle heats the plastic to + + align:start position:0% +a nozzle the nozzle heats the plastic to + + + align:start position:0% +a nozzle the nozzle heats the plastic to +soften it so that the plastic can be + + align:start position:0% +soften it so that the plastic can be + + + align:start position:0% +soften it so that the plastic can be +laid out to build a 3d object basically + + align:start position:0% +laid out to build a 3d object basically + + + align:start position:0% +laid out to build a 3d object basically +it is like piling a piece of string on + + align:start position:0% +it is like piling a piece of string on + + + align:start position:0% +it is like piling a piece of string on +top of itself to make a 3d shape because + + align:start position:0% +top of itself to make a 3d shape because + + + align:start position:0% +top of itself to make a 3d shape because +the votes needed to be less dense than + + align:start position:0% +the votes needed to be less dense than + + + align:start position:0% +the votes needed to be less dense than +the liquids they were to float on we + + align:start position:0% +the liquids they were to float on we + + + align:start position:0% +the liquids they were to float on we +specify that the votes were to be + + align:start position:0% +specify that the votes were to be + + + align:start position:0% +specify that the votes were to be +printed sparsely such that the plastic + + align:start position:0% +printed sparsely such that the plastic + + + align:start position:0% +printed sparsely such that the plastic +thread was to be laid out loosely + + align:start position:0% +thread was to be laid out loosely + + + align:start position:0% +thread was to be laid out loosely +whenever possible in the interior of the + + align:start position:0% +whenever possible in the interior of the + + + align:start position:0% +whenever possible in the interior of the +boats once we had our boat it was time + + align:start position:0% +boats once we had our boat it was time + + + align:start position:0% +boats once we had our boat it was time +to check and see if it did what we + + align:start position:0% +to check and see if it did what we + + + align:start position:0% +to check and see if it did what we +wanted it to of course our very first + + align:start position:0% +wanted it to of course our very first + + + align:start position:0% +wanted it to of course our very first +boat wasn't the ideal solution the + + align:start position:0% +boat wasn't the ideal solution the + + + align:start position:0% +boat wasn't the ideal solution the +reservoir was too small and the boat was + + align:start position:0% +reservoir was too small and the boat was + + + align:start position:0% +reservoir was too small and the boat was +too large it didn't hold enough fuel and + + align:start position:0% +too large it didn't hold enough fuel and + + + align:start position:0% +too large it didn't hold enough fuel and +move slowly because of the mass but it + + align:start position:0% +move slowly because of the mass but it + + + align:start position:0% +move slowly because of the mass but it +gave us insight into what we needed to + + align:start position:0% +gave us insight into what we needed to + + + align:start position:0% +gave us insight into what we needed to +change we modified our plan created a + + align:start position:0% +change we modified our plan created a + + + align:start position:0% +change we modified our plan created a +new design and tested it again after + + align:start position:0% +new design and tested it again after + + + align:start position:0% +new design and tested it again after +some troubleshooting we went through + + align:start position:0% +some troubleshooting we went through + + + align:start position:0% +some troubleshooting we went through +several design iterations we examined + + align:start position:0% +several design iterations we examined + + + align:start position:0% +several design iterations we examined +many different boat designs and liqueurs + + align:start position:0% +many different boat designs and liqueurs + + + align:start position:0% +many different boat designs and liqueurs +to use as fuel until we had a design we + + align:start position:0% +to use as fuel until we had a design we + + + align:start position:0% +to use as fuel until we had a design we +were happy with I presented my project + + align:start position:0% +were happy with I presented my project + + + align:start position:0% +were happy with I presented my project +to the class at the end of the course I + + align:start position:0% +to the class at the end of the course I + + + align:start position:0% +to the class at the end of the course I +successfully stayed within the design + + align:start position:0% +successfully stayed within the design + + + align:start position:0% +successfully stayed within the design +and project constraints I created a boat + + align:start position:0% +and project constraints I created a boat + + + align:start position:0% +and project constraints I created a boat +that used edible materials for + + align:start position:0% +that used edible materials for + + + align:start position:0% +that used edible materials for +propulsion through the Marangoni effect + + align:start position:0% +propulsion through the Marangoni effect + + + align:start position:0% +propulsion through the Marangoni effect +after completing the course project we + + align:start position:0% +after completing the course project we + + + align:start position:0% +after completing the course project we +continued to pursue this idea we wanted + + align:start position:0% +continued to pursue this idea we wanted + + + align:start position:0% +continued to pursue this idea we wanted +to improve our design and also make the + + align:start position:0% +to improve our design and also make the + + + align:start position:0% +to improve our design and also make the +boat out of edible material so that they + + align:start position:0% +boat out of edible material so that they + + + align:start position:0% +boat out of edible material so that they +could be used as a fun garnish for + + align:start position:0% +could be used as a fun garnish for + + + align:start position:0% +could be used as a fun garnish for +drinks this required us to generalize + + align:start position:0% +drinks this required us to generalize + + + align:start position:0% +drinks this required us to generalize +our solution to a new situation we + + align:start position:0% +our solution to a new situation we + + + align:start position:0% +our solution to a new situation we +constructed soft flexible molds out of + + align:start position:0% +constructed soft flexible molds out of + + + align:start position:0% +constructed soft flexible molds out of +silicone by 3d printing rigid plastic + + align:start position:0% +silicone by 3d printing rigid plastic + + + align:start position:0% +silicone by 3d printing rigid plastic +molds that the silicone molds could be + + align:start position:0% +molds that the silicone molds could be + + + align:start position:0% +molds that the silicone molds could be +made from after creating the molds we + + align:start position:0% +made from after creating the molds we + + + align:start position:0% +made from after creating the molds we +tried several edible materials for the + + align:start position:0% +tried several edible materials for the + + + align:start position:0% +tried several edible materials for the +boat including candy chocolate and marsh + + align:start position:0% +boat including candy chocolate and marsh + + + align:start position:0% +boat including candy chocolate and marsh +Mallos we quickly discovered that the + + align:start position:0% +Mallos we quickly discovered that the + + + align:start position:0% +Mallos we quickly discovered that the +density of the material is a common + + align:start position:0% +density of the material is a common + + + align:start position:0% +density of the material is a common +limiting factor after further testing we + + align:start position:0% +limiting factor after further testing we + + + align:start position:0% +limiting factor after further testing we +found two materials that worked edible + + align:start position:0% +found two materials that worked edible + + + align:start position:0% +found two materials that worked edible +wax and gelatin which we foam as it sets + + align:start position:0% +wax and gelatin which we foam as it sets + + + align:start position:0% +wax and gelatin which we foam as it sets +to reduce the density of the boat we've + + align:start position:0% +to reduce the density of the boat we've + + + align:start position:0% +to reduce the density of the boat we've +since disseminated our product I want to + + align:start position:0% +since disseminated our product I want to + + + align:start position:0% +since disseminated our product I want to +design award at a competition at MIT and + + align:start position:0% +design award at a competition at MIT and + + + align:start position:0% +design award at a competition at MIT and +we're currently working with chef Jose + + align:start position:0% +we're currently working with chef Jose + + + align:start position:0% +we're currently working with chef Jose +Andres to incorporate our design into + + align:start position:0% +Andres to incorporate our design into + + + align:start position:0% +Andres to incorporate our design into +his restaurant additionally an article + + align:start position:0% +his restaurant additionally an article + + + align:start position:0% +his restaurant additionally an article +in the American Society for engineering + + align:start position:0% +in the American Society for engineering + + + align:start position:0% +in the American Society for engineering +education prism magazine helped spread + + align:start position:0% +education prism magazine helped spread + + + align:start position:0% +education prism magazine helped spread +our ideas and product to a broader + + align:start position:0% +our ideas and product to a broader + + + align:start position:0% +our ideas and product to a broader +audience to review in order to solve + + align:start position:0% +audience to review in order to solve + + + align:start position:0% +audience to review in order to solve +this problem we had to define the + + align:start position:0% +this problem we had to define the + + + align:start position:0% +this problem we had to define the +problem gather information explore plan + + align:start position:0% +problem gather information explore plan + + + align:start position:0% +problem gather information explore plan +act and then check our solution we were + + align:start position:0% +act and then check our solution we were + + + align:start position:0% +act and then check our solution we were +able to generalize our solution to a new + + align:start position:0% +able to generalize our solution to a new + + + align:start position:0% +able to generalize our solution to a new +context and then disseminate our results + + align:start position:0% +context and then disseminate our results + + + align:start position:0% +context and then disseminate our results +the problem-solving process really + + align:start position:0% +the problem-solving process really + + + align:start position:0% +the problem-solving process really +helped us approach this problem and + + align:start position:0% +helped us approach this problem and + + + align:start position:0% +helped us approach this problem and +break it down by consciously using a + + align:start position:0% +break it down by consciously using a + + + align:start position:0% +break it down by consciously using a +problem-solving process you will find + + align:start position:0% +problem-solving process you will find + + + align:start position:0% +problem-solving process you will find +that you'll become a more confident and + + align:start position:0% +that you'll become a more confident and + + + align:start position:0% +that you'll become a more confident and +better problem solver best of luck + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/ZjjpLMKs7Tc.txt b/ZjjpLMKs7Tc.txt new file mode 100644 index 0000000000000000000000000000000000000000..c5d4cab715873d9679fcacf80d622f27d4a007aa --- /dev/null +++ b/ZjjpLMKs7Tc.txt @@ -0,0 +1,9858 @@ +align:start position:0% + +okay so let's uh continue our discussion + + align:start position:0% +okay so let's uh continue our discussion + + + align:start position:0% +okay so let's uh continue our discussion +of + + align:start position:0% + + + + align:start position:0% + +series so last time + + align:start position:0% +series so last time + + + align:start position:0% +series so last time +we proved the comparison test + + align:start position:0% + + + + align:start position:0% + +or the end of last time + + align:start position:0% +or the end of last time + + + align:start position:0% +or the end of last time +so this was a comparison test + + align:start position:0% + + + + align:start position:0% + +so which + + align:start position:0% +so which + + + align:start position:0% +so which +is a statement about + + align:start position:0% +is a statement about + + + align:start position:0% +is a statement about +series with non-negative terms with one + + align:start position:0% +series with non-negative terms with one + + + align:start position:0% +series with non-negative terms with one +being smaller than the other + + align:start position:0% + + + + align:start position:0% + +and one of two things + + align:start position:0% +and one of two things + + + align:start position:0% +and one of two things +or two things are true + + align:start position:0% +or two things are true + + + align:start position:0% +or two things are true +if + + align:start position:0% +if + + + align:start position:0% +if +i have x in and y and non-negative with + + align:start position:0% +i have x in and y and non-negative with + + + align:start position:0% +i have x in and y and non-negative with +y n bigger than or equal to x in + + align:start position:0% +y n bigger than or equal to x in + + + align:start position:0% +y n bigger than or equal to x in +then the conclusion is if the bigger + + align:start position:0% +then the conclusion is if the bigger + + + align:start position:0% +then the conclusion is if the bigger +series converges + + align:start position:0% + + + + align:start position:0% + +this implies that the smaller series + + align:start position:0% +this implies that the smaller series + + + align:start position:0% +this implies that the smaller series +converges + + align:start position:0% + + + + align:start position:0% + +and the second statement is if + + align:start position:0% +and the second statement is if + + + align:start position:0% +and the second statement is if +the smaller + + align:start position:0% +the smaller + + + align:start position:0% +the smaller +series diverges + + align:start position:0% + + + + align:start position:0% + +then + + align:start position:0% +then + + + align:start position:0% +then +the larger series + + align:start position:0% + + + + align:start position:0% + +diverges + + align:start position:0% +diverges + + + align:start position:0% +diverges +and we also proved not using the + + align:start position:0% +and we also proved not using the + + + align:start position:0% +and we also proved not using the +comparison test but + + align:start position:0% +comparison test but + + + align:start position:0% +comparison test but +for p series that uh + + align:start position:0% +for p series that uh + + + align:start position:0% +for p series that uh +the series 1 + + align:start position:0% +the series 1 + + + align:start position:0% +the series 1 +sum from n equals 1 to infinity of 1 + + align:start position:0% +sum from n equals 1 to infinity of 1 + + + align:start position:0% +sum from n equals 1 to infinity of 1 +over n to the p + + align:start position:0% +over n to the p + + + align:start position:0% +over n to the p +this + + align:start position:0% + + + + align:start position:0% + +converges well i mean we did use a + + align:start position:0% +converges well i mean we did use a + + + align:start position:0% +converges well i mean we did use a +comparison test + + align:start position:0% +comparison test + + + align:start position:0% +comparison test +for one direction i guess so 1 over n to + + align:start position:0% +for one direction i guess so 1 over n to + + + align:start position:0% +for one direction i guess so 1 over n to +the p converges if and only if p is + + align:start position:0% +the p converges if and only if p is + + + align:start position:0% +the p converges if and only if p is +bigger than one so + + align:start position:0% +bigger than one so + + + align:start position:0% +bigger than one so +this converging implied p has to be + + align:start position:0% +this converging implied p has to be + + + align:start position:0% +this converging implied p has to be +bigger than one by the comparison test + + align:start position:0% +bigger than one by the comparison test + + + align:start position:0% +bigger than one by the comparison test +and what we know about + + align:start position:0% +and what we know about + + + align:start position:0% +and what we know about +the harmonic series one over n + + align:start position:0% +the harmonic series one over n + + + align:start position:0% +the harmonic series one over n +sum of one over n + + align:start position:0% +sum of one over n + + + align:start position:0% +sum of one over n +okay so + + align:start position:0% +okay so + + + align:start position:0% +okay so +you know typically in applications you + + align:start position:0% +you know typically in applications you + + + align:start position:0% +you know typically in applications you +use these two theorems together + + align:start position:0% +use these two theorems together + + + align:start position:0% +use these two theorems together +to say something about series that don't + + align:start position:0% +to say something about series that don't + + + align:start position:0% +to say something about series that don't +look so + + align:start position:0% +look so + + + align:start position:0% +look so +simple so for example + + align:start position:0% + + + + align:start position:0% + +um if i look at + + align:start position:0% +um if i look at + + + align:start position:0% +um if i look at +the series + + align:start position:0% + + + + align:start position:0% + +1 over n squared plus 20 + + align:start position:0% +1 over n squared plus 20 + + + align:start position:0% +1 over n squared plus 20 +20 n + + align:start position:0% + + + + align:start position:0% + +n equals + + align:start position:0% +n equals + + + align:start position:0% +n equals +1 to infinity + + align:start position:0% +1 to infinity + + + align:start position:0% +1 to infinity +so one could ask oh does this converge + + align:start position:0% +so one could ask oh does this converge + + + align:start position:0% +so one could ask oh does this converge +diverge + + align:start position:0% +diverge + + + align:start position:0% +diverge +well this is a + + align:start position:0% +well this is a + + + align:start position:0% +well this is a +series with non-negative terms and + + align:start position:0% +series with non-negative terms and + + + align:start position:0% +series with non-negative terms and +remember i mean the bigger thing has to + + align:start position:0% +remember i mean the bigger thing has to + + + align:start position:0% +remember i mean the bigger thing has to +converge + + align:start position:0% +converge + + + align:start position:0% +converge +to give you + + align:start position:0% +to give you + + + align:start position:0% +to give you +to imply that the smaller thing + + align:start position:0% +to imply that the smaller thing + + + align:start position:0% +to imply that the smaller thing +converges and if the smaller thing + + align:start position:0% +converges and if the smaller thing + + + align:start position:0% +converges and if the smaller thing +diverges then the bigger thing diverges + + align:start position:0% +diverges then the bigger thing diverges + + + align:start position:0% +diverges then the bigger thing diverges +so don't get the inequalities mixed up + + align:start position:0% +so don't get the inequalities mixed up + + + align:start position:0% +so don't get the inequalities mixed up +so + + align:start position:0% +so + + + align:start position:0% +so +i have + + align:start position:0% +i have + + + align:start position:0% +i have +1 over n squared plus 20 + + align:start position:0% + + + + align:start position:0% + + + align:start position:0% + + + align:start position:0% +in + + align:start position:0% +in + + + align:start position:0% +in +this 20 20 times n is just making things + + align:start position:0% +this 20 20 times n is just making things + + + align:start position:0% +this 20 20 times n is just making things +bigger on the bottom and therefore + + align:start position:0% +bigger on the bottom and therefore + + + align:start position:0% +bigger on the bottom and therefore +smaller overall so this is less than or + + align:start position:0% +smaller overall so this is less than or + + + align:start position:0% +smaller overall so this is less than or +equal to one over n squared + + align:start position:0% +equal to one over n squared + + + align:start position:0% +equal to one over n squared +and + + align:start position:0% + + + + align:start position:0% + +since this converges + + align:start position:0% + + + + align:start position:0% + +this implies by the comparison test that + + align:start position:0% +this implies by the comparison test that + + + align:start position:0% +this implies by the comparison test that +the sum from n equals 1 to infinity of 1 + + align:start position:0% +the sum from n equals 1 to infinity of 1 + + + align:start position:0% +the sum from n equals 1 to infinity of 1 +over + + align:start position:0% +over + + + align:start position:0% +over +n squared plus 20 20 + + align:start position:0% +n squared plus 20 20 + + + align:start position:0% +n squared plus 20 20 +n also + + align:start position:0% + + + + align:start position:0% + +converges + + align:start position:0% +converges + + + align:start position:0% +converges +okay + + align:start position:0% +okay + + + align:start position:0% +okay +now um + + align:start position:0% +now um + + + align:start position:0% +now um +you know a mistake i'm sure we've all + + align:start position:0% +you know a mistake i'm sure we've all + + + align:start position:0% +you know a mistake i'm sure we've all +made at some point is mixing up the + + align:start position:0% +made at some point is mixing up the + + + align:start position:0% +made at some point is mixing up the +inequality + + align:start position:0% +inequality + + + align:start position:0% +inequality +and um + + align:start position:0% +and um + + + align:start position:0% +and um +not getting quite + + align:start position:0% +not getting quite + + + align:start position:0% +not getting quite +the right answer so for example + + align:start position:0% +the right answer so for example + + + align:start position:0% +the right answer so for example +it is also true that 1 over n squared + + align:start position:0% +it is also true that 1 over n squared + + + align:start position:0% +it is also true that 1 over n squared +plus 20 + + align:start position:0% +plus 20 + + + align:start position:0% +plus 20 +20 n is certainly less than or equal to + + align:start position:0% +20 n is certainly less than or equal to + + + align:start position:0% +20 n is certainly less than or equal to +1 over 20 + + align:start position:0% + + + + align:start position:0% + +1 over 20 20 times n which is also less + + align:start position:0% +1 over 20 20 times n which is also less + + + align:start position:0% +1 over 20 20 times n which is also less +than or equal to 1 over n + + align:start position:0% +than or equal to 1 over n + + + align:start position:0% +than or equal to 1 over n +and so you're tempted to say + + align:start position:0% + + + + align:start position:0% + +since this diverges + + align:start position:0% + + + + align:start position:0% + +implies + + align:start position:0% + + + + align:start position:0% + +the other + + align:start position:0% +the other + + + align:start position:0% +the other +series diverges + + align:start position:0% + + + + align:start position:0% + +but + + align:start position:0% +but + + + align:start position:0% +but +this is uh + + align:start position:0% + + + + align:start position:0% + +not right okay because the inequality is + + align:start position:0% +not right okay because the inequality is + + + align:start position:0% +not right okay because the inequality is +wrong remember if you want to apply the + + align:start position:0% +wrong remember if you want to apply the + + + align:start position:0% +wrong remember if you want to apply the +comparison test + + align:start position:0% +comparison test + + + align:start position:0% +comparison test +you either have to have a bigger series + + align:start position:0% +you either have to have a bigger series + + + align:start position:0% +you either have to have a bigger series +which converges + + align:start position:0% +which converges + + + align:start position:0% +which converges +or a smaller series which diverges okay + + align:start position:0% +or a smaller series which diverges okay + + + align:start position:0% +or a smaller series which diverges okay +here we came up with a bigger series + + align:start position:0% +here we came up with a bigger series + + + align:start position:0% +here we came up with a bigger series +which diverges which gives us no + + align:start position:0% +which diverges which gives us no + + + align:start position:0% +which diverges which gives us no +information at all + + align:start position:0% +information at all + + + align:start position:0% +information at all +okay it's if we have a bigger series + + align:start position:0% +okay it's if we have a bigger series + + + align:start position:0% +okay it's if we have a bigger series +like one over n squared that we know + + align:start position:0% +like one over n squared that we know + + + align:start position:0% +like one over n squared that we know +converges + + align:start position:0% +converges + + + align:start position:0% +converges +then do we get information about the + + align:start position:0% +then do we get information about the + + + align:start position:0% +then do we get information about the +original series + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +okay so let's do + + align:start position:0% +okay so let's do + + + align:start position:0% +okay so let's do +um let's do another well-known test or + + align:start position:0% +um let's do another well-known test or + + + align:start position:0% +um let's do another well-known test or +at least + + align:start position:0% +at least + + + align:start position:0% +at least +test you should remember from + + align:start position:0% +test you should remember from + + + align:start position:0% +test you should remember from +calculus so-called ratio tests + + align:start position:0% + + + + align:start position:0% + +so what is the statement of this so + + align:start position:0% +so what is the statement of this so + + + align:start position:0% +so what is the statement of this so +suppose + + align:start position:0% + + + + align:start position:0% + +xn does not equal 0 + + align:start position:0% + + + + align:start position:0% + +for all n + + align:start position:0% + + + + align:start position:0% + +and this limit + + align:start position:0% +and this limit + + + align:start position:0% +and this limit +l + + align:start position:0% + + + + align:start position:0% + +equals the limit as n goes to infinity + + align:start position:0% +equals the limit as n goes to infinity + + + align:start position:0% +equals the limit as n goes to infinity +of x to the n plus 1 + + align:start position:0% +of x to the n plus 1 + + + align:start position:0% +of x to the n plus 1 +over x to the n and absolute value + + align:start position:0% +over x to the n and absolute value + + + align:start position:0% +over x to the n and absolute value +exists + + align:start position:0% + + + + align:start position:0% + +all right + + align:start position:0% +all right + + + align:start position:0% +all right +then + + align:start position:0% + + + + align:start position:0% + +if l is less than 1 + + align:start position:0% +if l is less than 1 + + + align:start position:0% +if l is less than 1 +this implies that + + align:start position:0% +this implies that + + + align:start position:0% +this implies that +the series + + align:start position:0% +the series + + + align:start position:0% +the series +x n + + align:start position:0% + + + + align:start position:0% + +converges absolutely + + align:start position:0% + + + + align:start position:0% + +and if l + + align:start position:0% +and if l + + + align:start position:0% +and if l +is bigger than one + + align:start position:0% +is bigger than one + + + align:start position:0% +is bigger than one +then the series + + align:start position:0% +then the series + + + align:start position:0% +then the series +diverges + + align:start position:0% + + + + align:start position:0% + +now what about l equals one there's no + + align:start position:0% +now what about l equals one there's no + + + align:start position:0% +now what about l equals one there's no +information for l equals one + + align:start position:0% + + + + align:start position:0% + +meaning + + align:start position:0% +meaning + + + align:start position:0% +meaning +you could have + + align:start position:0% +you could have + + + align:start position:0% +you could have +a series so that this l equals one + + align:start position:0% +a series so that this l equals one + + + align:start position:0% +a series so that this l equals one +and + + align:start position:0% +and + + + align:start position:0% +and +you know you could have a series where + + align:start position:0% +you know you could have a series where + + + align:start position:0% +you know you could have a series where +it diverges and you could also have a + + align:start position:0% +it diverges and you could also have a + + + align:start position:0% +it diverges and you could also have a +series where l equals one in the series + + align:start position:0% +series where l equals one in the series + + + align:start position:0% +series where l equals one in the series +converges so for + + align:start position:0% +converges so for + + + align:start position:0% +converges so for +example um + + align:start position:0% +example um + + + align:start position:0% +example um +x n equals + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% +um + + + align:start position:0% +um +one over n + + align:start position:0% +one over n + + + align:start position:0% +one over n +for example + + align:start position:0% +for example + + + align:start position:0% +for example +or i mean even worse + + align:start position:0% +or i mean even worse + + + align:start position:0% +or i mean even worse +let's say one + + align:start position:0% + + + + align:start position:0% + +okay for all in + + align:start position:0% + + + + align:start position:0% + +but we know that the series + + align:start position:0% + + + + align:start position:0% + +one diverges because the individual + + align:start position:0% +one diverges because the individual + + + align:start position:0% +one diverges because the individual +terms do not convert to zero they're + + align:start position:0% +terms do not convert to zero they're + + + align:start position:0% +terms do not convert to zero they're +just one the whole time + + align:start position:0% +just one the whole time + + + align:start position:0% +just one the whole time +okay + + align:start position:0% +okay + + + align:start position:0% +okay +but + + align:start position:0% +but + + + align:start position:0% +but +for x n equals let's say one over + + align:start position:0% +for x n equals let's say one over + + + align:start position:0% +for x n equals let's say one over +n squared so the one we just saw a + + align:start position:0% +n squared so the one we just saw a + + + align:start position:0% +n squared so the one we just saw a +minute ago + + align:start position:0% + + + + align:start position:0% + +implies l which is the limit as n goes + + align:start position:0% +implies l which is the limit as n goes + + + align:start position:0% +implies l which is the limit as n goes +to infinity + + align:start position:0% +to infinity + + + align:start position:0% +to infinity +of n plus 1 + + align:start position:0% +of n plus 1 + + + align:start position:0% +of n plus 1 +squared over n squared + + align:start position:0% +squared over n squared + + + align:start position:0% +squared over n squared +equals the limit + + align:start position:0% +equals the limit + + + align:start position:0% +equals the limit +as n goes to infinity dividing through + + align:start position:0% +as n goes to infinity dividing through + + + align:start position:0% +as n goes to infinity dividing through +1 plus 1 over n + + align:start position:0% + + + + align:start position:0% + +squared and this equals 1 plus 0 + + align:start position:0% +squared and this equals 1 plus 0 + + + align:start position:0% +squared and this equals 1 plus 0 +squared equals 1. + + align:start position:0% +squared equals 1. + + + align:start position:0% +squared equals 1. +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so + + align:start position:0% +so + + + align:start position:0% +so +for this + + align:start position:0% +for this + + + align:start position:0% +for this +series + + align:start position:0% +series + + + align:start position:0% +series +the root or the ratio + + align:start position:0% +the root or the ratio + + + align:start position:0% +the root or the ratio +uh + + align:start position:0% +uh + + + align:start position:0% +uh +gives + + align:start position:0% +gives + + + align:start position:0% +gives +this l is one + + align:start position:0% + + + + align:start position:0% + +and this series converges + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so + + align:start position:0% +so + + + align:start position:0% +so +again for the case that l equals one we + + align:start position:0% +again for the case that l equals one we + + + align:start position:0% +again for the case that l equals one we +have no information we can't say + + align:start position:0% +have no information we can't say + + + align:start position:0% +have no information we can't say +anything uh based on + + align:start position:0% +anything uh based on + + + align:start position:0% +anything uh based on +on + + align:start position:0% +on + + + align:start position:0% +on +this theorem gives us no information + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +all right we're going to prove this + + align:start position:0% +all right we're going to prove this + + + align:start position:0% +all right we're going to prove this +theorem um + + align:start position:0% +theorem um + + + align:start position:0% +theorem um +basically by um + + align:start position:0% + + + + align:start position:0% + +so we're not exactly going to use a + + align:start position:0% +so we're not exactly going to use a + + + align:start position:0% +so we're not exactly going to use a +comparison test but we are still going + + align:start position:0% +comparison test but we are still going + + + align:start position:0% +comparison test but we are still going +to compare + + align:start position:0% +to compare + + + align:start position:0% +to compare +this series satisfying + + align:start position:0% +this series satisfying + + + align:start position:0% +this series satisfying +you know one of these two assumptions to + + align:start position:0% +you know one of these two assumptions to + + + align:start position:0% +you know one of these two assumptions to +a series we know which is uh namely the + + align:start position:0% +a series we know which is uh namely the + + + align:start position:0% +a series we know which is uh namely the +the ratio test for number one so first + + align:start position:0% +the ratio test for number one so first + + + align:start position:0% +the ratio test for number one so first +off let's get um + + align:start position:0% +off let's get um + + + align:start position:0% +off let's get um +let's get number + + align:start position:0% +let's get number + + + align:start position:0% +let's get number +two out of the way + + align:start position:0% + + + + align:start position:0% + +so let's suppose + + align:start position:0% + + + + align:start position:0% + +l is bigger than one + + align:start position:0% + + + + align:start position:0% + +let alpha + + align:start position:0% + + + + align:start position:0% + +be a number between one + + align:start position:0% +be a number between one + + + align:start position:0% +be a number between one +and l + + align:start position:0% + + + + align:start position:0% + +actually we don't even need to do that + + align:start position:0% + + + + align:start position:0% + +so here's + + align:start position:0% + + + + align:start position:0% + +here's one here's l + + align:start position:0% + + + + align:start position:0% + +so since + + align:start position:0% +so since + + + align:start position:0% +so since +xn plus 1 over + + align:start position:0% +xn plus 1 over + + + align:start position:0% +xn plus 1 over +xn absolute value converges to l + + align:start position:0% +xn absolute value converges to l + + + align:start position:0% +xn absolute value converges to l +there exists + + align:start position:0% +there exists + + + align:start position:0% +there exists +an integer m0 + + align:start position:0% +an integer m0 + + + align:start position:0% +an integer m0 +so it's a natural + + align:start position:0% +so it's a natural + + + align:start position:0% +so it's a natural +number so that + + align:start position:0% +number so that + + + align:start position:0% +number so that +for all n bigger than or equal to m zero + + align:start position:0% +for all n bigger than or equal to m zero + + + align:start position:0% +for all n bigger than or equal to m zero +x n plus one over x n + + align:start position:0% +x n plus one over x n + + + align:start position:0% +x n plus one over x n +absolute value is bigger than or equal + + align:start position:0% +absolute value is bigger than or equal + + + align:start position:0% +absolute value is bigger than or equal +to so + + align:start position:0% +to so + + + align:start position:0% +to so +here + + align:start position:0% +here + + + align:start position:0% +here +you could write 1 as this is equal to + + align:start position:0% + + + + align:start position:0% + +l plus + + align:start position:0% +l plus + + + align:start position:0% +l plus +say minus + + align:start position:0% +say minus + + + align:start position:0% +say minus +l minus 1. + + align:start position:0% +l minus 1. + + + align:start position:0% +l minus 1. +so think of this as being epsilon in the + + align:start position:0% +so think of this as being epsilon in the + + + align:start position:0% +so think of this as being epsilon in the +definition of convergence + + align:start position:0% +definition of convergence + + + align:start position:0% +definition of convergence +okay + + align:start position:0% + + + + align:start position:0% + +and so + + align:start position:0% + + + + align:start position:0% + +this is over here l plus + + align:start position:0% +this is over here l plus + + + align:start position:0% +this is over here l plus +l minus 1. + + align:start position:0% +l minus 1. + + + align:start position:0% +l minus 1. +so by the definition of convergence uh + + align:start position:0% +so by the definition of convergence uh + + + align:start position:0% +so by the definition of convergence uh +for all n sufficiently large x n plus + + align:start position:0% +for all n sufficiently large x n plus + + + align:start position:0% +for all n sufficiently large x n plus +one over x n an absolute value has to be + + align:start position:0% +one over x n an absolute value has to be + + + align:start position:0% +one over x n an absolute value has to be +in this interval so it has to be bigger + + align:start position:0% +in this interval so it has to be bigger + + + align:start position:0% +in this interval so it has to be bigger +than or equal to one + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +which implies that for all + + align:start position:0% +which implies that for all + + + align:start position:0% +which implies that for all +n bigger than or equal to m 0 + + align:start position:0% +n bigger than or equal to m 0 + + + align:start position:0% +n bigger than or equal to m 0 +x n plus 1 is bigger than or equal to + + align:start position:0% +x n plus 1 is bigger than or equal to + + + align:start position:0% +x n plus 1 is bigger than or equal to +xn + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and + + align:start position:0% +and + + + align:start position:0% +and +so i could write this as saying that x + + align:start position:0% +so i could write this as saying that x + + + align:start position:0% +so i could write this as saying that x +m0 is less than or equal to x + + align:start position:0% +m0 is less than or equal to x + + + align:start position:0% +m0 is less than or equal to x +and 0 plus 1 is less than or equal to + + align:start position:0% +and 0 plus 1 is less than or equal to + + + align:start position:0% +and 0 plus 1 is less than or equal to +x m0 plus 2 + + align:start position:0% +x m0 plus 2 + + + align:start position:0% +x m0 plus 2 +and so on + + align:start position:0% +and so on + + + align:start position:0% +and so on +um + + align:start position:0% +um + + + align:start position:0% +um +but this implies that + + align:start position:0% + + + + align:start position:0% + +that these x ends cannot converge to + + align:start position:0% +that these x ends cannot converge to + + + align:start position:0% +that these x ends cannot converge to +zero + + align:start position:0% + + + + align:start position:0% + +as n goes to infinity because + + align:start position:0% +as n goes to infinity because + + + align:start position:0% +as n goes to infinity because +for all n bigger than or equal to m0 + + align:start position:0% +for all n bigger than or equal to m0 + + + align:start position:0% +for all n bigger than or equal to m0 +they're increasing + + align:start position:0% +they're increasing + + + align:start position:0% +they're increasing +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and the only way for an increasing + + align:start position:0% +and the only way for an increasing + + + align:start position:0% +and the only way for an increasing +sequence which is not negative to + + align:start position:0% +sequence which is not negative to + + + align:start position:0% +sequence which is not negative to +converge to zero is for them all to be + + align:start position:0% +converge to zero is for them all to be + + + align:start position:0% +converge to zero is for them all to be +nuns for them all to be zero and we're + + align:start position:0% +nuns for them all to be zero and we're + + + align:start position:0% +nuns for them all to be zero and we're +assuming they're not zero okay + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% +um + + + align:start position:0% +um +okay so that proves two + + align:start position:0% +okay so that proves two + + + align:start position:0% +okay so that proves two +let's prove one + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% + + + + align:start position:0% + +suppose l is now less than one + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +now let + + align:start position:0% +now let + + + align:start position:0% +now let +alpha be a number uh + + align:start position:0% +alpha be a number uh + + + align:start position:0% +alpha be a number uh +between l and one so i just want to give + + align:start position:0% +between l and one so i just want to give + + + align:start position:0% +between l and one so i just want to give +myself a little bit of room + + align:start position:0% +myself a little bit of room + + + align:start position:0% +myself a little bit of room +to work as you'll see in just a second + + align:start position:0% +to work as you'll see in just a second + + + align:start position:0% +to work as you'll see in just a second +so by the same + + align:start position:0% + + + + align:start position:0% + +reasoning as before + + align:start position:0% +reasoning as before + + + align:start position:0% +reasoning as before +so here's + + align:start position:0% +so here's + + + align:start position:0% +so here's +l + + align:start position:0% +l + + + align:start position:0% +l +alpha + + align:start position:0% +alpha + + + align:start position:0% +alpha +1 alpha i can write + + align:start position:0% +1 alpha i can write + + + align:start position:0% +1 alpha i can write +as l + + align:start position:0% +as l + + + align:start position:0% +as l +plus + + align:start position:0% +plus + + + align:start position:0% +plus +alpha minus l so i should think of this + + align:start position:0% +alpha minus l so i should think of this + + + align:start position:0% +alpha minus l so i should think of this +so think of this as kind of an epsilon + + align:start position:0% + + + + align:start position:0% + +then + + align:start position:0% + + + + align:start position:0% + +since x n plus 1 + + align:start position:0% +since x n plus 1 + + + align:start position:0% +since x n plus 1 +over x in an absolute value converges to + + align:start position:0% +over x in an absolute value converges to + + + align:start position:0% +over x in an absolute value converges to +l + + align:start position:0% + + + + align:start position:0% + +which is less than alpha there exists an + + align:start position:0% +which is less than alpha there exists an + + + align:start position:0% +which is less than alpha there exists an +m naught + + align:start position:0% +m naught + + + align:start position:0% +m naught +natural number + + align:start position:0% + + + + align:start position:0% + +so that + + align:start position:0% +so that + + + align:start position:0% +so that +while n bigger than or equal to m 0 + + align:start position:0% + + + + align:start position:0% + +x n plus 1 over x in an absolute value + + align:start position:0% +x n plus 1 over x in an absolute value + + + align:start position:0% +x n plus 1 over x in an absolute value +is less than or equal to alpha + + align:start position:0% + + + + align:start position:0% + +okay so here i have alpha just a little + + align:start position:0% +okay so here i have alpha just a little + + + align:start position:0% +okay so here i have alpha just a little +bit bigger than l + + align:start position:0% +bit bigger than l + + + align:start position:0% +bit bigger than l +and if i draw + + align:start position:0% +and if i draw + + + align:start position:0% +and if i draw +so this is l + + align:start position:0% +so this is l + + + align:start position:0% +so this is l +minus + + align:start position:0% +minus + + + align:start position:0% +minus +alpha minus l + + align:start position:0% +alpha minus l + + + align:start position:0% +alpha minus l +so since i have um this sequence here + + align:start position:0% +so since i have um this sequence here + + + align:start position:0% +so since i have um this sequence here +converging to l for all + + align:start position:0% +converging to l for all + + + align:start position:0% +converging to l for all +insufficiently large + + align:start position:0% +insufficiently large + + + align:start position:0% +insufficiently large +this + + align:start position:0% +this + + + align:start position:0% +this +should be in this interval meaning + + align:start position:0% +should be in this interval meaning + + + align:start position:0% +should be in this interval meaning +this should be less than or equal to + + align:start position:0% +this should be less than or equal to + + + align:start position:0% +this should be less than or equal to +alpha + + align:start position:0% +alpha + + + align:start position:0% +alpha +okay + + align:start position:0% + + + + align:start position:0% + +then for all n bigger than or equal to + + align:start position:0% +then for all n bigger than or equal to + + + align:start position:0% +then for all n bigger than or equal to +m0 so let me just write this uh + + align:start position:0% +m0 so let me just write this uh + + + align:start position:0% +m0 so let me just write this uh +slightly differently x + + align:start position:0% +slightly differently x + + + align:start position:0% +slightly differently x +sub n plus 1 + + align:start position:0% +sub n plus 1 + + + align:start position:0% +sub n plus 1 +is less than or equal to alpha + + align:start position:0% + + + + align:start position:0% + +times the absolute value of x of n + + align:start position:0% + + + + align:start position:0% + +now + + align:start position:0% + + + + align:start position:0% + +let's uh + + align:start position:0% + + + + align:start position:0% + +let's see what this means + + align:start position:0% + + + + align:start position:0% + +for all n bigger than or equal to m sub + + align:start position:0% +for all n bigger than or equal to m sub + + + align:start position:0% +for all n bigger than or equal to m sub +zero + + align:start position:0% +zero + + + align:start position:0% +zero +let's say i look at the absolute value + + align:start position:0% +let's say i look at the absolute value + + + align:start position:0% +let's say i look at the absolute value +of x sub n + + align:start position:0% + + + + align:start position:0% + +so now this n has nothing to do with + + align:start position:0% +so now this n has nothing to do with + + + align:start position:0% +so now this n has nothing to do with +these end it's just that + + align:start position:0% + + + + align:start position:0% + +so then the absolute value of x sub n is + + align:start position:0% +so then the absolute value of x sub n is + + + align:start position:0% +so then the absolute value of x sub n is +less than or equal to + + align:start position:0% + + + + align:start position:0% + +x + + align:start position:0% + + + + align:start position:0% + +so maybe i'm off by + + align:start position:0% + + + + align:start position:0% + +okay so let's let's + + align:start position:0% +okay so let's let's + + + align:start position:0% +okay so let's let's +increase that by one + + align:start position:0% + + + + align:start position:0% + +well okay so let's not + + align:start position:0% +well okay so let's not + + + align:start position:0% +well okay so let's not +let's not be confusing here + + align:start position:0% +let's not be confusing here + + + align:start position:0% +let's not be confusing here +let's make this + + align:start position:0% +let's make this + + + align:start position:0% +let's make this +let's make this l + + align:start position:0% +let's make this l + + + align:start position:0% +let's make this l +let's make that l + + align:start position:0% +let's make that l + + + align:start position:0% +let's make that l +so + + align:start position:0% +so + + + align:start position:0% +so +for all + + align:start position:0% +for all + + + align:start position:0% +for all +l bigger than or equal to m zero plus + + align:start position:0% +l bigger than or equal to m zero plus + + + align:start position:0% +l bigger than or equal to m zero plus +one + + align:start position:0% +one + + + align:start position:0% +one +um so think of l as playing the role of + + align:start position:0% +um so think of l as playing the role of + + + align:start position:0% +um so think of l as playing the role of +being n plus one + + align:start position:0% +being n plus one + + + align:start position:0% +being n plus one +this is less than or equal to l + + align:start position:0% +this is less than or equal to l + + + align:start position:0% +this is less than or equal to l +x to the l minus one + + align:start position:0% +x to the l minus one + + + align:start position:0% +x to the l minus one +which is less than or equal to x to the + + align:start position:0% +which is less than or equal to x to the + + + align:start position:0% +which is less than or equal to x to the +l minus two + + align:start position:0% +l minus two + + + align:start position:0% +l minus two +now with a square so + + align:start position:0% + + + + align:start position:0% + +what i have here is now f times alpha + + align:start position:0% +what i have here is now f times alpha + + + align:start position:0% +what i have here is now f times alpha +x to the l minus two + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +now let's drop again + + align:start position:0% + + + + align:start position:0% + +by 1 and i can do this + + align:start position:0% +by 1 and i can do this + + + align:start position:0% +by 1 and i can do this +as long as + + align:start position:0% + + + + align:start position:0% + +this quantity here is bigger than or + + align:start position:0% +this quantity here is bigger than or + + + align:start position:0% +this quantity here is bigger than or +equal to m + + align:start position:0% +equal to m + + + align:start position:0% +equal to m +so i get this is + + align:start position:0% +so i get this is + + + align:start position:0% +so i get this is +if i keep doing that this is less than + + align:start position:0% +if i keep doing that this is less than + + + align:start position:0% +if i keep doing that this is less than +or equal to alpha + + align:start position:0% +or equal to alpha + + + align:start position:0% +or equal to alpha +to the + + align:start position:0% + + + + align:start position:0% + +l minus m naught + + align:start position:0% + + + + align:start position:0% + +x to the m naught + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +okay um + + align:start position:0% + + + + align:start position:0% + +and so actually let's + + align:start position:0% +and so actually let's + + + align:start position:0% +and so actually let's +since we shifted things + + align:start position:0% + + + + align:start position:0% + +okay so + + align:start position:0% + + + + align:start position:0% + +all right + + align:start position:0% +all right + + + align:start position:0% +all right +now we're going to use this to bound the + + align:start position:0% +now we're going to use this to bound the + + + align:start position:0% +now we're going to use this to bound the +partial sums of the x of n + + align:start position:0% +partial sums of the x of n + + + align:start position:0% +partial sums of the x of n +so + + align:start position:0% + + + + align:start position:0% + +let me be a natural number + + align:start position:0% +let me be a natural number + + + align:start position:0% +let me be a natural number +and if we look at + + align:start position:0% +and if we look at + + + align:start position:0% +and if we look at +partial sum sum from n equals 1 to m + + align:start position:0% +partial sum sum from n equals 1 to m + + + align:start position:0% +partial sum sum from n equals 1 to m +of x sub n this is equal to + + align:start position:0% +of x sub n this is equal to + + + align:start position:0% +of x sub n this is equal to +some n equals 1 + + align:start position:0% + + + + align:start position:0% + +to m naught + + align:start position:0% +to m naught + + + align:start position:0% +to m naught +x n plus + + align:start position:0% +x n plus + + + align:start position:0% +x n plus +sum from n equals m naught plus 1 + + align:start position:0% +sum from n equals m naught plus 1 + + + align:start position:0% +sum from n equals m naught plus 1 +to m + + align:start position:0% + + + + align:start position:0% + +x + + align:start position:0% +x + + + align:start position:0% +x +sub + + align:start position:0% +sub + + + align:start position:0% +sub +now let me + + align:start position:0% +now let me + + + align:start position:0% +now let me +just change dummy variables for for + + align:start position:0% +just change dummy variables for for + + + align:start position:0% +just change dummy variables for for +signing for the + + align:start position:0% +signing for the + + + align:start position:0% +signing for the +indexing this + + align:start position:0% + + + + align:start position:0% + +so this is equal to the sum from n + + align:start position:0% +so this is equal to the sum from n + + + align:start position:0% +so this is equal to the sum from n +equals 1 to m naught of + + align:start position:0% +equals 1 to m naught of + + + align:start position:0% +equals 1 to m naught of +x n + + align:start position:0% +x n + + + align:start position:0% +x n +and now + + align:start position:0% + + + + align:start position:0% + +this i'm going to use this inequality + + align:start position:0% +this i'm going to use this inequality + + + align:start position:0% +this i'm going to use this inequality +here so + + align:start position:0% +here so + + + align:start position:0% +here so +okay this is kind of a mess + + align:start position:0% + + + + align:start position:0% + +so this is the inequality + + align:start position:0% +so this is the inequality + + + align:start position:0% +so this is the inequality +that i get + + align:start position:0% + + + + align:start position:0% + +from this + + align:start position:0% +from this + + + align:start position:0% +from this +remember alpha is less than one + + align:start position:0% + + + + align:start position:0% + +plus + + align:start position:0% + + + + align:start position:0% + +okay so + + align:start position:0% +okay so + + + align:start position:0% +okay so +times + + align:start position:0% +times + + + align:start position:0% +times +l equals + + align:start position:0% +l equals + + + align:start position:0% +l equals +and not plus 1 + + align:start position:0% +and not plus 1 + + + align:start position:0% +and not plus 1 +to m okay everything's fine + + align:start position:0% +to m okay everything's fine + + + align:start position:0% +to m okay everything's fine +times + + align:start position:0% +times + + + align:start position:0% +times +alpha to the l minus + + align:start position:0% + + + + align:start position:0% + +m not plus 1. okay so all i did here was + + align:start position:0% +m not plus 1. okay so all i did here was + + + align:start position:0% +m not plus 1. okay so all i did here was +replace + + align:start position:0% +replace + + + align:start position:0% +replace +this + + align:start position:0% +this + + + align:start position:0% +this +absolute value of x to the of x sub l l + + align:start position:0% +absolute value of x to the of x sub l l + + + align:start position:0% +absolute value of x to the of x sub l l +is just a dummy variable for indexing + + align:start position:0% +is just a dummy variable for indexing + + + align:start position:0% +is just a dummy variable for indexing +these guys but using this uh inequality + + align:start position:0% +these guys but using this uh inequality + + + align:start position:0% +these guys but using this uh inequality +here + + align:start position:0% +here + + + align:start position:0% +here +all right so sorry i kind of + + align:start position:0% + + + + align:start position:0% + +mess that up a little bit but the + + align:start position:0% +mess that up a little bit but the + + + align:start position:0% +mess that up a little bit but the +important thing is that we have this + + align:start position:0% +important thing is that we have this + + + align:start position:0% +important thing is that we have this +inequality which somehow + + align:start position:0% +inequality which somehow + + + align:start position:0% +inequality which somehow +tells you this + + align:start position:0% +tells you this + + + align:start position:0% +tells you this +um series is not that far from being a + + align:start position:0% +um series is not that far from being a + + + align:start position:0% +um series is not that far from being a +geometric series at least when l is big + + align:start position:0% +geometric series at least when l is big + + + align:start position:0% +geometric series at least when l is big +enough + + align:start position:0% +enough + + + align:start position:0% +enough +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so then when we take an arbitrary + + align:start position:0% +so then when we take an arbitrary + + + align:start position:0% +so then when we take an arbitrary +partial sums we split it up into two + + align:start position:0% +partial sums we split it up into two + + + align:start position:0% +partial sums we split it up into two +parts uh the stuff that comes up to this + + align:start position:0% +parts uh the stuff that comes up to this + + + align:start position:0% +parts uh the stuff that comes up to this +integer m sub zero which we don't care + + align:start position:0% +integer m sub zero which we don't care + + + align:start position:0% +integer m sub zero which we don't care +about that's just a fixed number + + align:start position:0% +about that's just a fixed number + + + align:start position:0% +about that's just a fixed number +plus this + + align:start position:0% +plus this + + + align:start position:0% +plus this +uh part that we care about which is + + align:start position:0% +uh part that we care about which is + + + align:start position:0% +uh part that we care about which is +after + + align:start position:0% +after + + + align:start position:0% +after +uh this fixed number m0 + + align:start position:0% +uh this fixed number m0 + + + align:start position:0% +uh this fixed number m0 +and we use this inequality to replace + + align:start position:0% +and we use this inequality to replace + + + align:start position:0% +and we use this inequality to replace +this by x sub m0 plus one alpha to the l + + align:start position:0% +this by x sub m0 plus one alpha to the l + + + align:start position:0% +this by x sub m0 plus one alpha to the l +minus m0 plus one okay the thing to + + align:start position:0% +minus m0 plus one okay the thing to + + + align:start position:0% +minus m0 plus one okay the thing to +remember is that little m + + align:start position:0% +remember is that little m + + + align:start position:0% +remember is that little m +is the thing that's changing okay so + + align:start position:0% +is the thing that's changing okay so + + + align:start position:0% +is the thing that's changing okay so +we're trying to bound this + + align:start position:0% +we're trying to bound this + + + align:start position:0% +we're trying to bound this +independent of little m + + align:start position:0% +independent of little m + + + align:start position:0% +independent of little m +okay + + align:start position:0% +okay + + + align:start position:0% +okay +capital m sub zero that's just something + + align:start position:0% +capital m sub zero that's just something + + + align:start position:0% +capital m sub zero that's just something +fixed that could be a thousand all right + + align:start position:0% + + + + align:start position:0% + +so this is equal to sum from n equals 1 + + align:start position:0% +so this is equal to sum from n equals 1 + + + align:start position:0% +so this is equal to sum from n equals 1 +to + + align:start position:0% +to + + + align:start position:0% +to +m 0 + + align:start position:0% +m 0 + + + align:start position:0% +m 0 +x n plus + + align:start position:0% + + + + align:start position:0% + +x sub m0 plus 1. + + align:start position:0% + + + + align:start position:0% + +and now if i change + + align:start position:0% +and now if i change + + + align:start position:0% +and now if i change +the variable again so + + align:start position:0% +the variable again so + + + align:start position:0% +the variable again so +l starts at m 0 plus 1 and ends at m + + align:start position:0% +l starts at m 0 plus 1 and ends at m + + + align:start position:0% +l starts at m 0 plus 1 and ends at m +so this is now a sum if i go + + align:start position:0% +so this is now a sum if i go + + + align:start position:0% +so this is now a sum if i go +so now for the second sum + + align:start position:0% +so now for the second sum + + + align:start position:0% +so now for the second sum +n is equal to l minus m zero + + align:start position:0% +n is equal to l minus m zero + + + align:start position:0% +n is equal to l minus m zero +plus one + + align:start position:0% +plus one + + + align:start position:0% +plus one +so now n starts at zero and ends at m + + align:start position:0% + + + + align:start position:0% + +minus uh + + align:start position:0% +minus uh + + + align:start position:0% +minus uh +0 plus 1 + + align:start position:0% +0 plus 1 + + + align:start position:0% +0 plus 1 +alpha to the n + + align:start position:0% +alpha to the n + + + align:start position:0% +alpha to the n +okay again m is the little is the thing + + align:start position:0% +okay again m is the little is the thing + + + align:start position:0% +okay again m is the little is the thing +that's changing here and we're trying to + + align:start position:0% +that's changing here and we're trying to + + + align:start position:0% +that's changing here and we're trying to +bound this independently of little m but + + align:start position:0% +bound this independently of little m but + + + align:start position:0% +bound this independently of little m but +now we're in good shape because this + + align:start position:0% +now we're in good shape because this + + + align:start position:0% +now we're in good shape because this +looks like a geometric series + + align:start position:0% +looks like a geometric series + + + align:start position:0% +looks like a geometric series +alpha remember is less than one + + align:start position:0% +alpha remember is less than one + + + align:start position:0% +alpha remember is less than one +so + + align:start position:0% +so + + + align:start position:0% +so +this is less than or equal to sum from n + + align:start position:0% +this is less than or equal to sum from n + + + align:start position:0% +this is less than or equal to sum from n +equals one to m zero + + align:start position:0% +equals one to m zero + + + align:start position:0% +equals one to m zero +x sub n + + align:start position:0% +x sub n + + + align:start position:0% +x sub n +plus + + align:start position:0% +plus + + + align:start position:0% +plus +x of m 0 plus 1 times + + align:start position:0% +x of m 0 plus 1 times + + + align:start position:0% +x of m 0 plus 1 times +now + + align:start position:0% +now + + + align:start position:0% +now +instead of just being + + align:start position:0% +instead of just being + + + align:start position:0% +instead of just being +a sum from 0 up to m minus m 0 plus 1 + + align:start position:0% +a sum from 0 up to m minus m 0 plus 1 + + + align:start position:0% +a sum from 0 up to m minus m 0 plus 1 +why not throw + + align:start position:0% +why not throw + + + align:start position:0% +why not throw +all of it in there + + align:start position:0% + + + + align:start position:0% + +and this is equal to + + align:start position:0% +and this is equal to + + + align:start position:0% +and this is equal to +n equals 0 + + align:start position:0% +n equals 0 + + + align:start position:0% +n equals 0 +x n + + align:start position:0% +x n + + + align:start position:0% +x n +plus + + align:start position:0% +plus + + + align:start position:0% +plus +x sub m0 plus 1 + + align:start position:0% +x sub m0 plus 1 + + + align:start position:0% +x sub m0 plus 1 +times + + align:start position:0% +times + + + align:start position:0% +times +1 over 1 minus alpha remember alpha is a + + align:start position:0% +1 over 1 minus alpha remember alpha is a + + + align:start position:0% +1 over 1 minus alpha remember alpha is a +number that we fixed to be less than one + + align:start position:0% +number that we fixed to be less than one + + + align:start position:0% +number that we fixed to be less than one +all right + + align:start position:0% +all right + + + align:start position:0% +all right +if you try to do + + align:start position:0% +if you try to do + + + align:start position:0% +if you try to do +what we did before and not kind of fix + + align:start position:0% +what we did before and not kind of fix + + + align:start position:0% +what we did before and not kind of fix +the alpha just a little bit to the left + + align:start position:0% +the alpha just a little bit to the left + + + align:start position:0% +the alpha just a little bit to the left +of one and try to do everything with one + + align:start position:0% +of one and try to do everything with one + + + align:start position:0% +of one and try to do everything with one +you would have wound up + + align:start position:0% +you would have wound up + + + align:start position:0% +you would have wound up +with one to the n here and that that + + align:start position:0% +with one to the n here and that that + + + align:start position:0% +with one to the n here and that that +wouldn't have + + align:start position:0% +wouldn't have + + + align:start position:0% +wouldn't have +finished the proof that wouldn't have + + align:start position:0% +finished the proof that wouldn't have + + + align:start position:0% +finished the proof that wouldn't have +closed the proof but giving yourself a + + align:start position:0% +closed the proof but giving yourself a + + + align:start position:0% +closed the proof but giving yourself a +little bit of room which is why we fixed + + align:start position:0% +little bit of room which is why we fixed + + + align:start position:0% +little bit of room which is why we fixed +this alpha + + align:start position:0% + + + + align:start position:0% + +okay now this number here is independent + + align:start position:0% +okay now this number here is independent + + + align:start position:0% +okay now this number here is independent +of little + + align:start position:0% + + + + align:start position:0% + +m that's the whole point okay + + align:start position:0% +m that's the whole point okay + + + align:start position:0% +m that's the whole point okay +so + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +have we + + align:start position:0% +have we + + + align:start position:0% +have we +proven that for all natural numbers + + align:start position:0% +proven that for all natural numbers + + + align:start position:0% +proven that for all natural numbers +little m + + align:start position:0% +little m + + + align:start position:0% +little m +the nth + + align:start position:0% +the nth + + + align:start position:0% +the nth +partial sum + + align:start position:0% + + + + align:start position:0% + +is less than or equal to a fixed number + + align:start position:0% +is less than or equal to a fixed number + + + align:start position:0% +is less than or equal to a fixed number +given by + + align:start position:0% +given by + + + align:start position:0% +given by +some from + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +and therefore + + align:start position:0% +and therefore + + + align:start position:0% +and therefore +this sequence of partial sums is bounded + + align:start position:0% + + + + align:start position:0% + +and therefore converges + + align:start position:0% + + + + align:start position:0% + +all right so kind of the simplest + + align:start position:0% + + + + align:start position:0% + +application of this is um + + align:start position:0% +application of this is um + + + align:start position:0% +application of this is um +maybe a series that + + align:start position:0% +maybe a series that + + + align:start position:0% +maybe a series that +looks familiar so + + align:start position:0% + + + + align:start position:0% + +for all x so this is i guess a theorem + + align:start position:0% +for all x so this is i guess a theorem + + + align:start position:0% +for all x so this is i guess a theorem +slash example but for all x and r the + + align:start position:0% +slash example but for all x and r the + + + align:start position:0% +slash example but for all x and r the +series x to the n + + align:start position:0% +series x to the n + + + align:start position:0% +series x to the n +over n factorial + + align:start position:0% +over n factorial + + + align:start position:0% +over n factorial +n equals zero to infinity + + align:start position:0% + + + + align:start position:0% + +converges absolutely here um + + align:start position:0% + + + + align:start position:0% + +zero factorial is of course one + + align:start position:0% + + + + align:start position:0% + +okay and you just use the the ratio test + + align:start position:0% +okay and you just use the the ratio test + + + align:start position:0% +okay and you just use the the ratio test +right so + + align:start position:0% + + + + align:start position:0% + +of the x to the n plus 1 + + align:start position:0% +of the x to the n plus 1 + + + align:start position:0% +of the x to the n plus 1 +or the n plus first term over x to the n + + align:start position:0% +or the n plus first term over x to the n + + + align:start position:0% +or the n plus first term over x to the n +so + + align:start position:0% +so + + + align:start position:0% +so +absolute value + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% + + + + align:start position:0% + +this equals the limit as + + align:start position:0% +this equals the limit as + + + align:start position:0% +this equals the limit as +n goes to infinity of + + align:start position:0% +n goes to infinity of + + + align:start position:0% +n goes to infinity of +n plus 1 factorial is equal to n plus 1 + + align:start position:0% +n plus 1 factorial is equal to n plus 1 + + + align:start position:0% +n plus 1 factorial is equal to n plus 1 +times n factorial so this cancels with + + align:start position:0% +times n factorial so this cancels with + + + align:start position:0% +times n factorial so this cancels with +that n factorial and i get x + + align:start position:0% +that n factorial and i get x + + + align:start position:0% +that n factorial and i get x +over n + + align:start position:0% +over n + + + align:start position:0% +over n +plus 1. + + align:start position:0% +plus 1. + + + align:start position:0% +plus 1. +limit as n goes to infinity of just this + + align:start position:0% +limit as n goes to infinity of just this + + + align:start position:0% +limit as n goes to infinity of just this +fixed number over n plus one equals zero + + align:start position:0% +fixed number over n plus one equals zero + + + align:start position:0% +fixed number over n plus one equals zero +and this is certainly less than + + align:start position:0% +and this is certainly less than + + + align:start position:0% +and this is certainly less than +one + + align:start position:0% + + + + align:start position:0% + +and therefore by the ratio test + + align:start position:0% +and therefore by the ratio test + + + align:start position:0% +and therefore by the ratio test +this series converges absolutely + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +um + + align:start position:0% +um + + + align:start position:0% +um +you know + + align:start position:0% +you know + + + align:start position:0% +you know +i got a little hung up on exactly uh + + align:start position:0% +i got a little hung up on exactly uh + + + align:start position:0% +i got a little hung up on exactly uh +the indexes and matching them up uh + + align:start position:0% +the indexes and matching them up uh + + + align:start position:0% +the indexes and matching them up uh +precisely but + + align:start position:0% +precisely but + + + align:start position:0% +precisely but +the important thing to + + align:start position:0% +the important thing to + + + align:start position:0% +the important thing to +to take home from this proof was that + + align:start position:0% +to take home from this proof was that + + + align:start position:0% +to take home from this proof was that +when this + + align:start position:0% +when this + + + align:start position:0% +when this +ratio is less than one then + + align:start position:0% +ratio is less than one then + + + align:start position:0% +ratio is less than one then +this + + align:start position:0% +this + + + align:start position:0% +this +series behaves very much like um + + align:start position:0% +series behaves very much like um + + + align:start position:0% +series behaves very much like um +a geometric series for + + align:start position:0% +a geometric series for + + + align:start position:0% +a geometric series for +as the terms get very as you go far + + align:start position:0% +as the terms get very as you go far + + + align:start position:0% +as the terms get very as you go far +enough out + + align:start position:0% +enough out + + + align:start position:0% +enough out +in the terms + + align:start position:0% +in the terms + + + align:start position:0% +in the terms +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and + + align:start position:0% +and + + + align:start position:0% +and +this idea of just + + align:start position:0% +this idea of just + + + align:start position:0% +this idea of just +trying to relate the series to a simple + + align:start position:0% +trying to relate the series to a simple + + + align:start position:0% +trying to relate the series to a simple +series that you know a lot about name i + + align:start position:0% +series that you know a lot about name i + + + align:start position:0% +series that you know a lot about name i +mean + + align:start position:0% +mean + + + align:start position:0% +mean +basically the only series that you know + + align:start position:0% +basically the only series that you know + + + align:start position:0% +basically the only series that you know +everything about + + align:start position:0% +everything about + + + align:start position:0% +everything about +namely even how to sum it + + align:start position:0% +namely even how to sum it + + + align:start position:0% +namely even how to sum it +um + + align:start position:0% +um + + + align:start position:0% +um +this is how you get + + align:start position:0% +this is how you get + + + align:start position:0% +this is how you get +you know this test and this is also even + + align:start position:0% +you know this test and this is also even + + + align:start position:0% +you know this test and this is also even +simpler how you get the next test which + + align:start position:0% +simpler how you get the next test which + + + align:start position:0% +simpler how you get the next test which +is the root test + + align:start position:0% + + + + align:start position:0% + +so it's a root test + + align:start position:0% + + + + align:start position:0% + +let's take a series + + align:start position:0% + + + + align:start position:0% + +and suppose + + align:start position:0% + + + + align:start position:0% + +this l + + align:start position:0% +this l + + + align:start position:0% +this l +this limit + + align:start position:0% +this limit + + + align:start position:0% +this limit +l equals the limit as + + align:start position:0% +l equals the limit as + + + align:start position:0% +l equals the limit as +n goes to infinity + + align:start position:0% +n goes to infinity + + + align:start position:0% +n goes to infinity +of x sub n to the 1 over n + + align:start position:0% +of x sub n to the 1 over n + + + align:start position:0% +of x sub n to the 1 over n +exists + + align:start position:0% +exists + + + align:start position:0% +exists +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +then + + align:start position:0% +then + + + align:start position:0% +then +two conclusions just kind of just like + + align:start position:0% +two conclusions just kind of just like + + + align:start position:0% +two conclusions just kind of just like +in + + align:start position:0% +in + + + align:start position:0% +in +ratio tests + + align:start position:0% + + + + align:start position:0% + +if + + align:start position:0% +if + + + align:start position:0% +if +l is less than one + + align:start position:0% + + + + align:start position:0% + +and this implies that + + align:start position:0% +and this implies that + + + align:start position:0% +and this implies that +the series converges + + align:start position:0% + + + + align:start position:0% + +absolutely + + align:start position:0% + + + + align:start position:0% + +and if l is bigger than one + + align:start position:0% +and if l is bigger than one + + + align:start position:0% +and if l is bigger than one +then + + align:start position:0% + + + + align:start position:0% + +this series converges um + + align:start position:0% +this series converges um + + + align:start position:0% +this series converges um +no the series diverges + + align:start position:0% + + + + align:start position:0% + +okay and again just like in the ratio + + align:start position:0% +okay and again just like in the ratio + + + align:start position:0% +okay and again just like in the ratio +test um no + + align:start position:0% +test um no + + + align:start position:0% +test um no +no information for l equals one + + align:start position:0% + + + + align:start position:0% + +you take the same series that we looked + + align:start position:0% +you take the same series that we looked + + + align:start position:0% +you take the same series that we looked +at before + + align:start position:0% + + + + align:start position:0% + +let's see did i leave it up there yes + + align:start position:0% +let's see did i leave it up there yes + + + align:start position:0% +let's see did i leave it up there yes +so xn x sub n equals 1 for all in + + align:start position:0% +so xn x sub n equals 1 for all in + + + align:start position:0% +so xn x sub n equals 1 for all in +this + + align:start position:0% +this + + + align:start position:0% +this +limit here l exists it's equal to 1 and + + align:start position:0% +limit here l exists it's equal to 1 and + + + align:start position:0% +limit here l exists it's equal to 1 and +that series diverges + + align:start position:0% +that series diverges + + + align:start position:0% +that series diverges +if you look at one over n squared + + align:start position:0% +if you look at one over n squared + + + align:start position:0% +if you look at one over n squared +and i take + + align:start position:0% +and i take + + + align:start position:0% +and i take +this limit + + align:start position:0% +this limit + + + align:start position:0% +this limit +i again get one but that series + + align:start position:0% +i again get one but that series + + + align:start position:0% +i again get one but that series +converges okay so for + + align:start position:0% +converges okay so for + + + align:start position:0% +converges okay so for +capital l equals one + + align:start position:0% +capital l equals one + + + align:start position:0% +capital l equals one +we get no information + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +so let's uh + + align:start position:0% +so let's uh + + + align:start position:0% +so let's uh +and and in this case + + align:start position:0% +and and in this case + + + align:start position:0% +and and in this case +it's even clearer how + + align:start position:0% +it's even clearer how + + + align:start position:0% +it's even clearer how +you know we're relating + + align:start position:0% +you know we're relating + + + align:start position:0% +you know we're relating +um the series + + align:start position:0% +um the series + + + align:start position:0% +um the series +to a geometric series so + + align:start position:0% +to a geometric series so + + + align:start position:0% +to a geometric series so +let's + + align:start position:0% + + + + align:start position:0% + +in my notes i proved two first both + + align:start position:0% +in my notes i proved two first both + + + align:start position:0% +in my notes i proved two first both +times so perhaps i should have written + + align:start position:0% +times so perhaps i should have written + + + align:start position:0% +times so perhaps i should have written +it one two + + align:start position:0% +it one two + + + align:start position:0% +it one two +um + + align:start position:0% +um + + + align:start position:0% +um +i'll know for the future + + align:start position:0% +i'll know for the future + + + align:start position:0% +i'll know for the future +so + + align:start position:0% + + + + align:start position:0% + +suppose l is bigger than one + + align:start position:0% +suppose l is bigger than one + + + align:start position:0% +suppose l is bigger than one +okay and now we're going to show that + + align:start position:0% +okay and now we're going to show that + + + align:start position:0% +okay and now we're going to show that +this series diverges again by showing + + align:start position:0% +this series diverges again by showing + + + align:start position:0% +this series diverges again by showing +that the terms do not converge to zero + + align:start position:0% +that the terms do not converge to zero + + + align:start position:0% +that the terms do not converge to zero +so + + align:start position:0% +so + + + align:start position:0% +so +uh + + align:start position:0% +uh + + + align:start position:0% +uh +it's the same idea as before + + align:start position:0% +it's the same idea as before + + + align:start position:0% +it's the same idea as before +here's l + + align:start position:0% +here's l + + + align:start position:0% +here's l +here's one + + align:start position:0% +here's one + + + align:start position:0% +here's one +so for all n sufficiently large + + align:start position:0% + + + + align:start position:0% + +x to the n to the one over n + + align:start position:0% +x to the n to the one over n + + + align:start position:0% +x to the n to the one over n +has to be inside this + + align:start position:0% + + + + align:start position:0% + +interval and since + + align:start position:0% +interval and since + + + align:start position:0% +interval and since +x to the n + + align:start position:0% +x to the n + + + align:start position:0% +x to the n +x sub n to the one over n + + align:start position:0% +x sub n to the one over n + + + align:start position:0% +x sub n to the one over n +converges to l which is bigger than one + + align:start position:0% +converges to l which is bigger than one + + + align:start position:0% +converges to l which is bigger than one +this implies there exists + + align:start position:0% +this implies there exists + + + align:start position:0% +this implies there exists +an integer + + align:start position:0% +an integer + + + align:start position:0% +an integer +and zero such that + + align:start position:0% +and zero such that + + + align:start position:0% +and zero such that +for all + + align:start position:0% +for all + + + align:start position:0% +for all +n bigger than or equal to m 0 + + align:start position:0% +n bigger than or equal to m 0 + + + align:start position:0% +n bigger than or equal to m 0 +x sub n to the 1 over n + + align:start position:0% +x sub n to the 1 over n + + + align:start position:0% +x sub n to the 1 over n +is + + align:start position:0% +is + + + align:start position:0% +is +bigger than 1 + + align:start position:0% +bigger than 1 + + + align:start position:0% +bigger than 1 +which implies + + align:start position:0% +which implies + + + align:start position:0% +which implies +well n bigger than or equal to m0 x sub + + align:start position:0% +well n bigger than or equal to m0 x sub + + + align:start position:0% +well n bigger than or equal to m0 x sub +n an absolute value + + align:start position:0% +n an absolute value + + + align:start position:0% +n an absolute value +is bigger than by just taking n powers + + align:start position:0% +is bigger than by just taking n powers + + + align:start position:0% +is bigger than by just taking n powers +of both sides is bigger than one + + align:start position:0% +of both sides is bigger than one + + + align:start position:0% +of both sides is bigger than one +okay + + align:start position:0% +okay + + + align:start position:0% +okay +now since all of the absolute values of + + align:start position:0% +now since all of the absolute values of + + + align:start position:0% +now since all of the absolute values of +x of n's is bigger than one + + align:start position:0% + + + + align:start position:0% + +this implies that this cannot converge + + align:start position:0% +this implies that this cannot converge + + + align:start position:0% +this implies that this cannot converge +to zero all right + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so remember i mean uh + + align:start position:0% +so remember i mean uh + + + align:start position:0% +so remember i mean uh +let me remove this absolute value + + align:start position:0% +let me remove this absolute value + + + align:start position:0% +let me remove this absolute value +x sub n cannot converge to zero why i + + align:start position:0% +x sub n cannot converge to zero why i + + + align:start position:0% +x sub n cannot converge to zero why i +mean we could + + align:start position:0% +mean we could + + + align:start position:0% +mean we could +go back to the basic definition of + + align:start position:0% +go back to the basic definition of + + + align:start position:0% +go back to the basic definition of +convergence + + align:start position:0% +convergence + + + align:start position:0% +convergence +of what it means for a sequence to + + align:start position:0% +of what it means for a sequence to + + + align:start position:0% +of what it means for a sequence to +converge to a real number x + + align:start position:0% +converge to a real number x + + + align:start position:0% +converge to a real number x +um + + align:start position:0% +um + + + align:start position:0% +um +and what it doesn't mean or what it + + align:start position:0% +and what it doesn't mean or what it + + + align:start position:0% +and what it doesn't mean or what it +means for it to not converge to x so xn + + align:start position:0% +means for it to not converge to x so xn + + + align:start position:0% +means for it to not converge to x so xn +does not converge to 0 if there exists + + align:start position:0% +does not converge to 0 if there exists + + + align:start position:0% +does not converge to 0 if there exists +a bad epsilon so that x sub n is + + align:start position:0% +a bad epsilon so that x sub n is + + + align:start position:0% +a bad epsilon so that x sub n is +outside of that interval + + align:start position:0% +outside of that interval + + + align:start position:0% +outside of that interval +um + + align:start position:0% +um + + + align:start position:0% +um +as long uh + + align:start position:0% +as long uh + + + align:start position:0% +as long uh +is outside of that interval + + align:start position:0% +is outside of that interval + + + align:start position:0% +is outside of that interval +um + + align:start position:0% +um + + + align:start position:0% +um +if i go far enough out okay + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +we certainly have that here okay + + align:start position:0% + + + + align:start position:0% + +or you know you could use + + align:start position:0% +or you know you could use + + + align:start position:0% +or you know you could use +so + + align:start position:0% +so + + + align:start position:0% +so +this + + align:start position:0% +this + + + align:start position:0% +this +bigger than one in fact implies + + align:start position:0% +bigger than one in fact implies + + + align:start position:0% +bigger than one in fact implies +that + + align:start position:0% + + + + align:start position:0% + +the limb soup + + align:start position:0% +the limb soup + + + align:start position:0% +the limb soup +of x of n is bigger than one because if + + align:start position:0% +of x of n is bigger than one because if + + + align:start position:0% +of x of n is bigger than one because if +i have two sequences one bigger than the + + align:start position:0% +i have two sequences one bigger than the + + + align:start position:0% +i have two sequences one bigger than the +other then the limb soup of the bigger + + align:start position:0% +other then the limb soup of the bigger + + + align:start position:0% +other then the limb soup of the bigger +one is bigger than or equal to the limb + + align:start position:0% +one is bigger than or equal to the limb + + + align:start position:0% +one is bigger than or equal to the limb +soup of the other one which is one + + align:start position:0% +soup of the other one which is one + + + align:start position:0% +soup of the other one which is one +and + + align:start position:0% + + + + align:start position:0% + +you're doing in this week's assignment + + align:start position:0% +you're doing in this week's assignment + + + align:start position:0% +you're doing in this week's assignment +that + + align:start position:0% +that + + + align:start position:0% +that +this converges that xn converges to zero + + align:start position:0% +this converges that xn converges to zero + + + align:start position:0% +this converges that xn converges to zero +if and only if the limb soup of the + + align:start position:0% +if and only if the limb soup of the + + + align:start position:0% +if and only if the limb soup of the +absolute values of x ends converge to + + align:start position:0% +absolute values of x ends converge to + + + align:start position:0% +absolute values of x ends converge to +zero + + align:start position:0% +zero + + + align:start position:0% +zero +and um + + align:start position:0% +and um + + + align:start position:0% +and um +this is not it's bigger than or equal to + + align:start position:0% +this is not it's bigger than or equal to + + + align:start position:0% +this is not it's bigger than or equal to +one + + align:start position:0% + + + + align:start position:0% + +so i'll leave that there + + align:start position:0% + + + + align:start position:0% + +okay so now for + + align:start position:0% +okay so now for + + + align:start position:0% +okay so now for +the + + align:start position:0% +the + + + align:start position:0% +the +other case that + + align:start position:0% +other case that + + + align:start position:0% +other case that +l is less than one + + align:start position:0% + + + + align:start position:0% + +suppose l is less than one then + + align:start position:0% + + + + align:start position:0% + +let alpha be + + align:start position:0% +let alpha be + + + align:start position:0% +let alpha be +a number between l and one + + align:start position:0% + + + + align:start position:0% + +again since this converges to + + align:start position:0% +again since this converges to + + + align:start position:0% +again since this converges to +uh l which is less than alpha + + align:start position:0% +uh l which is less than alpha + + + align:start position:0% +uh l which is less than alpha +for all n sufficiently large this has to + + align:start position:0% +for all n sufficiently large this has to + + + align:start position:0% +for all n sufficiently large this has to +be less than alpha + + align:start position:0% +be less than alpha + + + align:start position:0% +be less than alpha +so there exists a integer + + align:start position:0% + + + + align:start position:0% + +i have + + align:start position:0% +i have + + + align:start position:0% +i have +x to the n to the 1 over n + + align:start position:0% +x to the n to the 1 over n + + + align:start position:0% +x to the n to the 1 over n +is less than + + align:start position:0% +is less than + + + align:start position:0% +is less than +alpha + + align:start position:0% +alpha + + + align:start position:0% +alpha +which implies that + + align:start position:0% + + + + align:start position:0% + +for all n + + align:start position:0% +for all n + + + align:start position:0% +for all n +bigger than or equal to m0 + + align:start position:0% +bigger than or equal to m0 + + + align:start position:0% +bigger than or equal to m0 +x to the n and absolute value is less + + align:start position:0% +x to the n and absolute value is less + + + align:start position:0% +x to the n and absolute value is less +than + + align:start position:0% +than + + + align:start position:0% +than +alpha to the n okay so here again we're + + align:start position:0% +alpha to the n okay so here again we're + + + align:start position:0% +alpha to the n okay so here again we're +seeing + + align:start position:0% +seeing + + + align:start position:0% +seeing +um + + align:start position:0% +um + + + align:start position:0% +um +this series if it satisfies these + + align:start position:0% +this series if it satisfies these + + + align:start position:0% +this series if it satisfies these +hypotheses + + align:start position:0% +hypotheses + + + align:start position:0% +hypotheses +is + + align:start position:0% +is + + + align:start position:0% +is +very much acting like a geometric series + + align:start position:0% +very much acting like a geometric series + + + align:start position:0% +very much acting like a geometric series +remember alpha is less than one + + align:start position:0% + + + + align:start position:0% + +then for every + + align:start position:0% +then for every + + + align:start position:0% +then for every +natural number little m if we look at + + align:start position:0% +natural number little m if we look at + + + align:start position:0% +natural number little m if we look at +the nth partial sum + + align:start position:0% +the nth partial sum + + + align:start position:0% +the nth partial sum +of the absolute value + + align:start position:0% +of the absolute value + + + align:start position:0% +of the absolute value +say n equals 1. + + align:start position:0% +say n equals 1. + + + align:start position:0% +say n equals 1. +this is we split it up again into the + + align:start position:0% +this is we split it up again into the + + + align:start position:0% +this is we split it up again into the +part into a part that we don't really + + align:start position:0% +part into a part that we don't really + + + align:start position:0% +part into a part that we don't really +care about + + align:start position:0% + + + + align:start position:0% + +plus a + + align:start position:0% +plus a + + + align:start position:0% +plus a +interesting part remember little m is + + align:start position:0% +interesting part remember little m is + + + align:start position:0% +interesting part remember little m is +the thing that's changing + + align:start position:0% +the thing that's changing + + + align:start position:0% +the thing that's changing +this should look like a little m + + align:start position:0% +this should look like a little m + + + align:start position:0% +this should look like a little m +compared to capital m 0. + + align:start position:0% +compared to capital m 0. + + + align:start position:0% +compared to capital m 0. +and this is less than or equal to sum + + align:start position:0% +and this is less than or equal to sum + + + align:start position:0% +and this is less than or equal to sum +from n equals 1 to m 0 + + align:start position:0% +from n equals 1 to m 0 + + + align:start position:0% +from n equals 1 to m 0 +x sub n again this is just a fixed + + align:start position:0% +x sub n again this is just a fixed + + + align:start position:0% +x sub n again this is just a fixed +number + + align:start position:0% +number + + + align:start position:0% +number +plus + + align:start position:0% +plus + + + align:start position:0% +plus +now we input this inequality + + align:start position:0% +now we input this inequality + + + align:start position:0% +now we input this inequality +um + + align:start position:0% +um + + + align:start position:0% +um +n equals m0 + + align:start position:0% +n equals m0 + + + align:start position:0% +n equals m0 +plus 1 + + align:start position:0% +plus 1 + + + align:start position:0% +plus 1 +m + + align:start position:0% +m + + + align:start position:0% +m +alpha to the n + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +this is less than or equal to + + align:start position:0% +this is less than or equal to + + + align:start position:0% +this is less than or equal to +sum from n equals m zero + + align:start position:0% +sum from n equals m zero + + + align:start position:0% +sum from n equals m zero +um + + align:start position:0% +um + + + align:start position:0% +um +i'm gonna go + + align:start position:0% +i'm gonna go + + + align:start position:0% +i'm gonna go +kind of fast here because i'm running + + align:start position:0% +kind of fast here because i'm running + + + align:start position:0% +kind of fast here because i'm running +out of space on the board here + + align:start position:0% +out of space on the board here + + + align:start position:0% +out of space on the board here +um maybe i'll write this out in just a + + align:start position:0% +um maybe i'll write this out in just a + + + align:start position:0% +um maybe i'll write this out in just a +minute but + + align:start position:0% +minute but + + + align:start position:0% +minute but +why this is true and + + align:start position:0% +why this is true and + + + align:start position:0% +why this is true and +this part here is less than or equal to + + align:start position:0% +this part here is less than or equal to + + + align:start position:0% +this part here is less than or equal to +one over one minus alpha + + align:start position:0% +one over one minus alpha + + + align:start position:0% +one over one minus alpha +okay + + align:start position:0% +okay + + + align:start position:0% +okay +because what do i do this sum is a + + align:start position:0% +because what do i do this sum is a + + + align:start position:0% +because what do i do this sum is a +finite sum + + align:start position:0% + + + + align:start position:0% + +and it's certainly bigger than if i + + align:start position:0% +and it's certainly bigger than if i + + + align:start position:0% +and it's certainly bigger than if i +make the lower bound smaller and the + + align:start position:0% +make the lower bound smaller and the + + + align:start position:0% +make the lower bound smaller and the +upper bound + + align:start position:0% + + + + align:start position:0% + +larger + + align:start position:0% + + + + align:start position:0% + +and this is just the imp partial sum + + align:start position:0% +and this is just the imp partial sum + + + align:start position:0% +and this is just the imp partial sum +corresponding to a geometric series with + + align:start position:0% +corresponding to a geometric series with + + + align:start position:0% +corresponding to a geometric series with +non-negative terms the alpha to the n + + align:start position:0% +non-negative terms the alpha to the n + + + align:start position:0% +non-negative terms the alpha to the n +and so that's less than or equal to sum + + align:start position:0% +and so that's less than or equal to sum + + + align:start position:0% +and so that's less than or equal to sum +from n equals 0 to infinity of alpha to + + align:start position:0% +from n equals 0 to infinity of alpha to + + + align:start position:0% +from n equals 0 to infinity of alpha to +the n which equals 1 over + + align:start position:0% +the n which equals 1 over + + + align:start position:0% +the n which equals 1 over +1 minus alpha + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so that's how we got this term and + + align:start position:0% +so that's how we got this term and + + + align:start position:0% +so that's how we got this term and +therefore the partial sums corresponding + + align:start position:0% +therefore the partial sums corresponding + + + align:start position:0% +therefore the partial sums corresponding +to + + align:start position:0% +to + + + align:start position:0% +to +the absolute the series with absolute + + align:start position:0% +the absolute the series with absolute + + + align:start position:0% +the absolute the series with absolute +values is bounded + + align:start position:0% +values is bounded + + + align:start position:0% +values is bounded +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and therefore + + align:start position:0% +and therefore + + + align:start position:0% +and therefore +that series + + align:start position:0% +that series + + + align:start position:0% +that series +with the absolute values converges and + + align:start position:0% +with the absolute values converges and + + + align:start position:0% +with the absolute values converges and +we have absolute convergence + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +all right so + + align:start position:0% + + + + align:start position:0% + +now let me state a theorem about + + align:start position:0% +now let me state a theorem about + + + align:start position:0% +now let me state a theorem about +alternating series it is not + + align:start position:0% +alternating series it is not + + + align:start position:0% +alternating series it is not +i prefer not to call it an alternating + + align:start position:0% +i prefer not to call it an alternating + + + align:start position:0% +i prefer not to call it an alternating +series test + + align:start position:0% +series test + + + align:start position:0% +series test +because there's nothing really to test + + align:start position:0% +because there's nothing really to test + + + align:start position:0% +because there's nothing really to test +i mean at least with the ratio and root + + align:start position:0% +i mean at least with the ratio and root + + + align:start position:0% +i mean at least with the ratio and root +test you have to compute a limit + + align:start position:0% +test you have to compute a limit + + + align:start position:0% +test you have to compute a limit +which might require some work to do + + align:start position:0% +which might require some work to do + + + align:start position:0% +which might require some work to do +and + + align:start position:0% +and + + + align:start position:0% +and +[Applause] + + align:start position:0% + + + + align:start position:0% + +and therefore at least to me that's kind + + align:start position:0% +and therefore at least to me that's kind + + + align:start position:0% +and therefore at least to me that's kind +of a + + align:start position:0% +of a + + + align:start position:0% +of a +real thing that you have to + + align:start position:0% +real thing that you have to + + + align:start position:0% +real thing that you have to +do a little work + + align:start position:0% +do a little work + + + align:start position:0% +do a little work +to test whether a series converges + + align:start position:0% +to test whether a series converges + + + align:start position:0% +to test whether a series converges +and + + align:start position:0% +and + + + align:start position:0% +and +for alternating series the test is you + + align:start position:0% +for alternating series the test is you + + + align:start position:0% +for alternating series the test is you +look at it + + align:start position:0% +look at it + + + align:start position:0% +look at it +and that's it + + align:start position:0% +and that's it + + + align:start position:0% +and that's it +you don't compute anything + + align:start position:0% +you don't compute anything + + + align:start position:0% +you don't compute anything +you look at it + + align:start position:0% +you look at it + + + align:start position:0% +you look at it +so i prefer not to call + + align:start position:0% +so i prefer not to call + + + align:start position:0% +so i prefer not to call +this theorem about alternating series + + align:start position:0% +this theorem about alternating series + + + align:start position:0% +this theorem about alternating series +and alternating series test + + align:start position:0% + + + + align:start position:0% + +so the theorem is for alternating series + + align:start position:0% + + + + align:start position:0% + +and statement is the following + + align:start position:0% + + + + align:start position:0% + +let x sub n + + align:start position:0% +let x sub n + + + align:start position:0% +let x sub n +be a + + align:start position:0% + + + + align:start position:0% + +monotone + + align:start position:0% + + + + align:start position:0% + +decreasing sequence + + align:start position:0% + + + + align:start position:0% + +converging to zero + + align:start position:0% + + + + align:start position:0% + +so because this thing is monotone and + + align:start position:0% +so because this thing is monotone and + + + align:start position:0% +so because this thing is monotone and +conv monotone decreasing and converging + + align:start position:0% +conv monotone decreasing and converging + + + align:start position:0% +conv monotone decreasing and converging +to zero um + + align:start position:0% +to zero um + + + align:start position:0% +to zero um +it's all + + align:start position:0% +it's all + + + align:start position:0% +it's all +so let me + + align:start position:0% +so let me + + + align:start position:0% +so let me +put this in parentheses + + align:start position:0% + + + + align:start position:0% + +before xn is bigger than or equal to 0 + + align:start position:0% +before xn is bigger than or equal to 0 + + + align:start position:0% +before xn is bigger than or equal to 0 +for all n + + align:start position:0% + + + + align:start position:0% + +i cannot have a monotone decreasing + + align:start position:0% +i cannot have a monotone decreasing + + + align:start position:0% +i cannot have a monotone decreasing +sequence converging to zero if one of + + align:start position:0% +sequence converging to zero if one of + + + align:start position:0% +sequence converging to zero if one of +the x ends is less than zero because + + align:start position:0% +the x ends is less than zero because + + + align:start position:0% +the x ends is less than zero because +they keep getting smaller + + align:start position:0% + + + + align:start position:0% + +this is uh this is it this is not + + align:start position:0% +this is uh this is it this is not + + + align:start position:0% +this is uh this is it this is not +this is all of the hypotheses you don't + + align:start position:0% +this is all of the hypotheses you don't + + + align:start position:0% +this is all of the hypotheses you don't +have to compute anything + + align:start position:0% +have to compute anything + + + align:start position:0% +have to compute anything +then + + align:start position:0% +then + + + align:start position:0% +then +the series + + align:start position:0% +the series + + + align:start position:0% +the series +minus 1 to the n + + align:start position:0% +minus 1 to the n + + + align:start position:0% +minus 1 to the n +x n + + align:start position:0% +x n + + + align:start position:0% +x n +n equals + + align:start position:0% +n equals + + + align:start position:0% +n equals +let's uh + + align:start position:0% +let's uh + + + align:start position:0% +let's uh +of course + + align:start position:0% +of course + + + align:start position:0% +of course +you know we don't have to start at one + + align:start position:0% +you know we don't have to start at one + + + align:start position:0% +you know we don't have to start at one +in particular but + + align:start position:0% +in particular but + + + align:start position:0% +in particular but +at least for this statement let's make + + align:start position:0% +at least for this statement let's make + + + align:start position:0% +at least for this statement let's make +it precise + + align:start position:0% +it precise + + + align:start position:0% +it precise +sum from n equals 1 to infinity of minus + + align:start position:0% +sum from n equals 1 to infinity of minus + + + align:start position:0% +sum from n equals 1 to infinity of minus +1 to the n x to the n x sub n + + align:start position:0% +1 to the n x to the n x sub n + + + align:start position:0% +1 to the n x to the n x sub n +converges + + align:start position:0% + + + + align:start position:0% + +all right and we can just say + + align:start position:0% +all right and we can just say + + + align:start position:0% +all right and we can just say +convergence not necessarily absolute + + align:start position:0% +convergence not necessarily absolute + + + align:start position:0% +convergence not necessarily absolute +convergence because again if we look at + + align:start position:0% +convergence because again if we look at + + + align:start position:0% +convergence because again if we look at +minus one to the n one over n which is + + align:start position:0% +minus one to the n one over n which is + + + align:start position:0% +minus one to the n one over n which is +one over n is a monotone decreasing + + align:start position:0% +one over n is a monotone decreasing + + + align:start position:0% +one over n is a monotone decreasing +sequence converging to zero that + + align:start position:0% +sequence converging to zero that + + + align:start position:0% +sequence converging to zero that +converges but not absolutely + + align:start position:0% + + + + align:start position:0% + +okay and if we have x sub n equal one + + align:start position:0% +okay and if we have x sub n equal one + + + align:start position:0% +okay and if we have x sub n equal one +over n squared again one over n squared + + align:start position:0% +over n squared again one over n squared + + + align:start position:0% +over n squared again one over n squared +is a monotone decreasing sequence + + align:start position:0% +is a monotone decreasing sequence + + + align:start position:0% +is a monotone decreasing sequence +converging to zero that would converge + + align:start position:0% +converging to zero that would converge + + + align:start position:0% +converging to zero that would converge +absolutely so we just have a statement + + align:start position:0% +absolutely so we just have a statement + + + align:start position:0% +absolutely so we just have a statement +about convergence + + align:start position:0% + + + + align:start position:0% + +all right + + align:start position:0% + + + + align:start position:0% + +so how we're going to do this + + align:start position:0% + + + + align:start position:0% + +is + + align:start position:0% + + + + align:start position:0% + +we are + + align:start position:0% +we are + + + align:start position:0% +we are +it's kind of like how we um proved + + align:start position:0% +it's kind of like how we um proved + + + align:start position:0% +it's kind of like how we um proved +convergence for + + align:start position:0% +convergence for + + + align:start position:0% +convergence for +um + + align:start position:0% +um + + + align:start position:0% +um +p series in that we're going to show + + align:start position:0% +p series in that we're going to show + + + align:start position:0% +p series in that we're going to show +that a + + align:start position:0% +that a + + + align:start position:0% +that a +certain subsequence of partial sums + + align:start position:0% +certain subsequence of partial sums + + + align:start position:0% +certain subsequence of partial sums +converges and then we're going to use + + align:start position:0% +converges and then we're going to use + + + align:start position:0% +converges and then we're going to use +that to show + + align:start position:0% +that to show + + + align:start position:0% +that to show +that the full sequence of partial sums + + align:start position:0% +that the full sequence of partial sums + + + align:start position:0% +that the full sequence of partial sums +converge okay + + align:start position:0% + + + + align:start position:0% + +all right so + + align:start position:0% + + + + align:start position:0% + +let me state this as claim one + + align:start position:0% +let me state this as claim one + + + align:start position:0% +let me state this as claim one +so + + align:start position:0% + + + + align:start position:0% + +the + + align:start position:0% + + + + align:start position:0% + +subsequence + + align:start position:0% +subsequence + + + align:start position:0% +subsequence +of partial sums s sub 2k + + align:start position:0% + + + + align:start position:0% + +so this is just the sum from n equals 1 + + align:start position:0% +so this is just the sum from n equals 1 + + + align:start position:0% +so this is just the sum from n equals 1 +to 2k + + align:start position:0% + + + + align:start position:0% + +we're going to show this converges + + align:start position:0% +we're going to show this converges + + + align:start position:0% +we're going to show this converges +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so again um + + align:start position:0% +so again um + + + align:start position:0% +so again um +just to become + + align:start position:0% +just to become + + + align:start position:0% +just to become +complete s of m this is the nth partial + + align:start position:0% +complete s of m this is the nth partial + + + align:start position:0% +complete s of m this is the nth partial +sum is the sum from n equals 1 + + align:start position:0% +sum is the sum from n equals 1 + + + align:start position:0% +sum is the sum from n equals 1 +to m + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +all right so how we're going to do this + + align:start position:0% +all right so how we're going to do this + + + align:start position:0% +all right so how we're going to do this +is we're going to show that this uh + + align:start position:0% +is we're going to show that this uh + + + align:start position:0% +is we're going to show that this uh +these partial sums are in fact monotone + + align:start position:0% +these partial sums are in fact monotone + + + align:start position:0% +these partial sums are in fact monotone +decreasing + + align:start position:0% +decreasing + + + align:start position:0% +decreasing +and bounded from below monotone + + align:start position:0% +and bounded from below monotone + + + align:start position:0% +and bounded from below monotone +decreasing + + align:start position:0% +decreasing + + + align:start position:0% +decreasing +basically because + + align:start position:0% + + + + align:start position:0% + +these guys are monotone decreasing + + align:start position:0% +these guys are monotone decreasing + + + align:start position:0% +these guys are monotone decreasing +and bounded from below + + align:start position:0% +and bounded from below + + + align:start position:0% +and bounded from below +by the same + + align:start position:0% +by the same + + + align:start position:0% +by the same +same reasoning okay + + align:start position:0% +same reasoning okay + + + align:start position:0% +same reasoning okay +so + + align:start position:0% +so + + + align:start position:0% +so +let's show that + + align:start position:0% + + + + align:start position:0% + +for k a natural number + + align:start position:0% + + + + align:start position:0% + +if i look at + + align:start position:0% +if i look at + + + align:start position:0% +if i look at +s 2 k + + align:start position:0% +s 2 k + + + align:start position:0% +s 2 k +so this is the sum + + align:start position:0% + + + + align:start position:0% + +n equals 1 2 k + + align:start position:0% +n equals 1 2 k + + + align:start position:0% +n equals 1 2 k +minus 1 to the n + + align:start position:0% +minus 1 to the n + + + align:start position:0% +minus 1 to the n +x sub n + + align:start position:0% +x sub n + + + align:start position:0% +x sub n +now i have the n equals 1 term which i + + align:start position:0% +now i have the n equals 1 term which i + + + align:start position:0% +now i have the n equals 1 term which i +can write as + + align:start position:0% + + + + align:start position:0% + +minus x so just + + align:start position:0% +minus x so just + + + align:start position:0% +minus x so just +writing this out in a certain way so + + align:start position:0% +writing this out in a certain way so + + + align:start position:0% +writing this out in a certain way so +this is minus x1 + + align:start position:0% +this is minus x1 + + + align:start position:0% +this is minus x1 +plus x2 + + align:start position:0% +plus x2 + + + align:start position:0% +plus x2 +minus x3 plus + + align:start position:0% +minus x3 plus + + + align:start position:0% +minus x3 plus +and then n equals 2k is even so then i + + align:start position:0% +and then n equals 2k is even so then i + + + align:start position:0% +and then n equals 2k is even so then i +get plus x + + align:start position:0% +get plus x + + + align:start position:0% +get plus x +2k + + align:start position:0% + + + + align:start position:0% + +this is equal to x sub 2 minus x sub 1 + + align:start position:0% +this is equal to x sub 2 minus x sub 1 + + + align:start position:0% +this is equal to x sub 2 minus x sub 1 +plus + + align:start position:0% +plus + + + align:start position:0% +plus +x sub 4 minus x sub 3 plus + + align:start position:0% + + + + align:start position:0% + +all the way to + + align:start position:0% +all the way to + + + align:start position:0% +all the way to +x sub 2 k minus x sub 2 k minus 1. + + align:start position:0% + + + + align:start position:0% + +now + + align:start position:0% +now + + + align:start position:0% +now +this sequence is monotone decreasing + + align:start position:0% +this sequence is monotone decreasing + + + align:start position:0% +this sequence is monotone decreasing +right so x sub 2 + + align:start position:0% +right so x sub 2 + + + align:start position:0% +right so x sub 2 +is going to be smaller than x sub 1 all + + align:start position:0% +is going to be smaller than x sub 1 all + + + align:start position:0% +is going to be smaller than x sub 1 all +right + + align:start position:0% +right + + + align:start position:0% +right +x sub 4 is going to be less than x sub + + align:start position:0% +x sub 4 is going to be less than x sub + + + align:start position:0% +x sub 4 is going to be less than x sub +3. + + align:start position:0% +3. + + + align:start position:0% +3. +all right + + align:start position:0% +all right + + + align:start position:0% +all right +x sub 2 k + + align:start position:0% +x sub 2 k + + + align:start position:0% +x sub 2 k +minus x sub 2 k minus 1 is less than + + align:start position:0% +minus x sub 2 k minus 1 is less than + + + align:start position:0% +minus x sub 2 k minus 1 is less than +zero so since uh + + align:start position:0% +zero so since uh + + + align:start position:0% +zero so since uh +this is monotone decreasing this is + + align:start position:0% +this is monotone decreasing this is + + + align:start position:0% +this is monotone decreasing this is +bigger than or equal to + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +what i just said has nothing to do with + + align:start position:0% +what i just said has nothing to do with + + + align:start position:0% +what i just said has nothing to do with +this inequality i'm writing here + + align:start position:0% + + + + align:start position:0% + +yet + + align:start position:0% + + + + align:start position:0% + +so i kept everything here and now i add + + align:start position:0% +so i kept everything here and now i add + + + align:start position:0% +so i kept everything here and now i add +uh x + + align:start position:0% +uh x + + + align:start position:0% +uh x +sub + + align:start position:0% +sub + + + align:start position:0% +sub +2k plus 2 minus x of + + align:start position:0% +2k plus 2 minus x of + + + align:start position:0% +2k plus 2 minus x of +2k plus 1. + + align:start position:0% + + + + align:start position:0% + +okay so what i was saying was that + + align:start position:0% +okay so what i was saying was that + + + align:start position:0% +okay so what i was saying was that +the x of n's are monotone decreasing + + align:start position:0% +the x of n's are monotone decreasing + + + align:start position:0% +the x of n's are monotone decreasing +this term is right after this term + + align:start position:0% +this term is right after this term + + + align:start position:0% +this term is right after this term +so it's smaller + + align:start position:0% +so it's smaller + + + align:start position:0% +so it's smaller +than this term so this term here + + align:start position:0% +than this term so this term here + + + align:start position:0% +than this term so this term here +is less than or equal to zero + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and therefore this thing plus itself + + align:start position:0% +and therefore this thing plus itself + + + align:start position:0% +and therefore this thing plus itself +plus something that's negative is less + + align:start position:0% +plus something that's negative is less + + + align:start position:0% +plus something that's negative is less +than or equal to this thing + + align:start position:0% +than or equal to this thing + + + align:start position:0% +than or equal to this thing +okay + + align:start position:0% + + + + align:start position:0% + +now what is this thing on the right hand + + align:start position:0% +now what is this thing on the right hand + + + align:start position:0% +now what is this thing on the right hand +side this is just uh + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +x + + align:start position:0% +x + + + align:start position:0% +x +2 k minus + + align:start position:0% +2 k minus + + + align:start position:0% +2 k minus +plus x 2 k minus x 2 k plus 1 plus x sub + + align:start position:0% +plus x 2 k minus x 2 k plus 1 plus x sub + + + align:start position:0% +plus x 2 k minus x 2 k plus 1 plus x sub + + align:start position:0% + + + align:start position:0% +k plus 1 and this is the k plus 1 + + align:start position:0% +k plus 1 and this is the k plus 1 + + + align:start position:0% +k plus 1 and this is the k plus 1 + + align:start position:0% + + + align:start position:0% +k plus 1 partial sum + + align:start position:0% + + + + align:start position:0% + +all right + + align:start position:0% + + + + align:start position:0% + +thus + + align:start position:0% +thus + + + align:start position:0% +thus +this + + align:start position:0% +this + + + align:start position:0% +this +series + + align:start position:0% + + + + align:start position:0% + +is monotone + + align:start position:0% + + + + align:start position:0% + +decreasing + + align:start position:0% +decreasing + + + align:start position:0% +decreasing +okay + + align:start position:0% + + + + align:start position:0% + +so to show that this subsequence of + + align:start position:0% +so to show that this subsequence of + + + align:start position:0% +so to show that this subsequence of +partial sums converges we just have to + + align:start position:0% +partial sums converges we just have to + + + align:start position:0% +partial sums converges we just have to +show that um this subsequence is bounded + + align:start position:0% +show that um this subsequence is bounded + + + align:start position:0% +show that um this subsequence is bounded +right or bounded below + + align:start position:0% +right or bounded below + + + align:start position:0% +right or bounded below +um + + align:start position:0% +um + + + align:start position:0% +um +if it's monotone decreasing it's already + + align:start position:0% +if it's monotone decreasing it's already + + + align:start position:0% +if it's monotone decreasing it's already +bounded + + align:start position:0% +bounded + + + align:start position:0% +bounded +above by something so we just need to + + align:start position:0% +above by something so we just need to + + + align:start position:0% +above by something so we just need to +show it's bounded from below + + align:start position:0% + + + + align:start position:0% + +now + + align:start position:0% + + + + align:start position:0% + +for all k a natural number + + align:start position:0% +for all k a natural number + + + align:start position:0% +for all k a natural number +let's look at s sub 2 k + + align:start position:0% +let's look at s sub 2 k + + + align:start position:0% +let's look at s sub 2 k +and group terms slightly differently + + align:start position:0% +and group terms slightly differently + + + align:start position:0% +and group terms slightly differently +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so this is equal now to i'm going to + + align:start position:0% +so this is equal now to i'm going to + + + align:start position:0% +so this is equal now to i'm going to +write it as minus x1 plus + + align:start position:0% +write it as minus x1 plus + + + align:start position:0% +write it as minus x1 plus +x + + align:start position:0% +x + + + align:start position:0% +x +sub 3 + + align:start position:0% + + + + align:start position:0% + +x sub 2 minus x sub 3 plus + + align:start position:0% +x sub 2 minus x sub 3 plus + + + align:start position:0% +x sub 2 minus x sub 3 plus +x sub 4 minus x sub 5 plus + + align:start position:0% +x sub 4 minus x sub 5 plus + + + align:start position:0% +x sub 4 minus x sub 5 plus +and so on + + align:start position:0% +and so on + + + align:start position:0% +and so on +plus + + align:start position:0% +plus + + + align:start position:0% +plus +x 2 k minus x 2 k minus 1. + + align:start position:0% +x 2 k minus x 2 k minus 1. + + + align:start position:0% +x 2 k minus x 2 k minus 1. +okay + + align:start position:0% +okay + + + align:start position:0% +okay +i think + + align:start position:0% + + + + align:start position:0% + +ah + + align:start position:0% +ah + + + align:start position:0% +ah +no that's not right + + align:start position:0% + + + + align:start position:0% + +okay so this is + + align:start position:0% +okay so this is + + + align:start position:0% +okay so this is +minus 2 + + align:start position:0% +minus 2 + + + align:start position:0% +minus 2 +plus x of + + align:start position:0% +plus x of + + + align:start position:0% +plus x of +2k all right + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +now this is right + + align:start position:0% +now this is right + + + align:start position:0% +now this is right +okay so this is equal to minus so + + align:start position:0% +okay so this is equal to minus so + + + align:start position:0% +okay so this is equal to minus so +again the x of n's are monotone + + align:start position:0% +again the x of n's are monotone + + + align:start position:0% +again the x of n's are monotone +decreasing + + align:start position:0% +decreasing + + + align:start position:0% +decreasing +all right so + + align:start position:0% +all right so + + + align:start position:0% +all right so +um x sub 3 is smaller than x sub 2 so + + align:start position:0% +um x sub 3 is smaller than x sub 2 so + + + align:start position:0% +um x sub 3 is smaller than x sub 2 so +this is non-negative + + align:start position:0% + + + + align:start position:0% + +this is also non-negative + + align:start position:0% +this is also non-negative + + + align:start position:0% +this is also non-negative +because x sub 5 is smaller than x sub 4 + + align:start position:0% +because x sub 5 is smaller than x sub 4 + + + align:start position:0% +because x sub 5 is smaller than x sub 4 +so on and so on so this is also + + align:start position:0% +so on and so on so this is also + + + align:start position:0% +so on and so on so this is also +non-negative so + + align:start position:0% +non-negative so + + + align:start position:0% +non-negative so +s sub 2 k is bigger than or equal to + + align:start position:0% +s sub 2 k is bigger than or equal to + + + align:start position:0% +s sub 2 k is bigger than or equal to +minus x sub 1 + + align:start position:0% +minus x sub 1 + + + align:start position:0% +minus x sub 1 +plus + + align:start position:0% +plus + + + align:start position:0% +plus +non-negative terms so + + align:start position:0% +non-negative terms so + + + align:start position:0% +non-negative terms so +2k and + + align:start position:0% +2k and + + + align:start position:0% +2k and +remember x sub + + align:start position:0% +remember x sub + + + align:start position:0% +remember x sub +ends these are monotone decreasing + + align:start position:0% +ends these are monotone decreasing + + + align:start position:0% +ends these are monotone decreasing +converging to zero and therefore that + + align:start position:0% +converging to zero and therefore that + + + align:start position:0% +converging to zero and therefore that +they're all non-negative so this is + + align:start position:0% +they're all non-negative so this is + + + align:start position:0% +they're all non-negative so this is +bigger than or equal to + + align:start position:0% +bigger than or equal to + + + align:start position:0% +bigger than or equal to +minus x sub one + + align:start position:0% +minus x sub one + + + align:start position:0% +minus x sub one +okay + + align:start position:0% + + + + align:start position:0% + +thus + + align:start position:0% +thus + + + align:start position:0% +thus +what do we get so + + align:start position:0% + + + + align:start position:0% + +for all natural numbers k + + align:start position:0% +for all natural numbers k + + + align:start position:0% +for all natural numbers k +i have minus x1 is less than or equal to + + align:start position:0% +i have minus x1 is less than or equal to + + + align:start position:0% +i have minus x1 is less than or equal to +s of 2k and because these are monotone + + align:start position:0% +s of 2k and because these are monotone + + + align:start position:0% +s of 2k and because these are monotone +decreasing this is always less than or + + align:start position:0% +decreasing this is always less than or + + + align:start position:0% +decreasing this is always less than or +equal to + + align:start position:0% +equal to + + + align:start position:0% +equal to +s + + align:start position:0% +s + + + align:start position:0% +s +k equals 1. + + align:start position:0% + + + + align:start position:0% + +all right + + align:start position:0% +all right + + + align:start position:0% +all right +and this is uh so if you like s sub 2 is + + align:start position:0% +and this is uh so if you like s sub 2 is + + + align:start position:0% +and this is uh so if you like s sub 2 is +just + + align:start position:0% +just + + + align:start position:0% +just +minus x sub 1 plus x sub 2. + + align:start position:0% +minus x sub 1 plus x sub 2. + + + align:start position:0% +minus x sub 1 plus x sub 2. +so + + align:start position:0% +so + + + align:start position:0% +so +this sequence of numbers is bounded + + align:start position:0% +this sequence of numbers is bounded + + + align:start position:0% +this sequence of numbers is bounded +between this real number and this real + + align:start position:0% +between this real number and this real + + + align:start position:0% +between this real number and this real +number and therefore it's bounded + + align:start position:0% +number and therefore it's bounded + + + align:start position:0% +number and therefore it's bounded +and since it's monotone decreasing it + + align:start position:0% +and since it's monotone decreasing it + + + align:start position:0% +and since it's monotone decreasing it +has to have a limit + + align:start position:0% + + + + align:start position:0% + +so s of 2k + + align:start position:0% +so s of 2k + + + align:start position:0% +so s of 2k +converges + + align:start position:0% + + + + align:start position:0% + +let's call this limit something + + align:start position:0% +let's call this limit something + + + align:start position:0% +let's call this limit something +let's call it s + + align:start position:0% + + + + align:start position:0% + +all right we'll show that + + align:start position:0% + + + + align:start position:0% + +the sequence of partial sums converge to + + align:start position:0% +the sequence of partial sums converge to + + + align:start position:0% +the sequence of partial sums converge to +s now we just showed this for along a + + align:start position:0% +s now we just showed this for along a + + + align:start position:0% +s now we just showed this for along a +sequence of + + align:start position:0% +sequence of + + + align:start position:0% +sequence of +along a subsequence of partial sums + + align:start position:0% +along a subsequence of partial sums + + + align:start position:0% +along a subsequence of partial sums +let's show it converges to s along the + + align:start position:0% +let's show it converges to s along the + + + align:start position:0% +let's show it converges to s along the +full sequence + + align:start position:0% + + + + align:start position:0% + +so this is if you like claim two + + align:start position:0% + + + + align:start position:0% + +which is + + align:start position:0% + + + + align:start position:0% + +that + + align:start position:0% + + + + align:start position:0% + +the full sequence of partial sums + + align:start position:0% +the full sequence of partial sums + + + align:start position:0% +the full sequence of partial sums +converges to s + + align:start position:0% + + + + align:start position:0% + +all right and we're going to do this + + align:start position:0% +all right and we're going to do this + + + align:start position:0% +all right and we're going to do this +by brute force using epsilon m + + align:start position:0% +by brute force using epsilon m + + + align:start position:0% +by brute force using epsilon m +argument + + align:start position:0% +argument + + + align:start position:0% +argument +so remember to show something + + align:start position:0% +so remember to show something + + + align:start position:0% +so remember to show something +a limit + + align:start position:0% +a limit + + + align:start position:0% +a limit +of something equals s means for all + + align:start position:0% +of something equals s means for all + + + align:start position:0% +of something equals s means for all +epsilon there exists a capital m so that + + align:start position:0% +epsilon there exists a capital m so that + + + align:start position:0% +epsilon there exists a capital m so that +for all n bigger than or equal to + + align:start position:0% +for all n bigger than or equal to + + + align:start position:0% +for all n bigger than or equal to +capital m s of m minus s an absolute + + align:start position:0% +capital m s of m minus s an absolute + + + align:start position:0% +capital m s of m minus s an absolute +value is less than epsilon okay so let + + align:start position:0% +value is less than epsilon okay so let + + + align:start position:0% +value is less than epsilon okay so let +epsilon be positive + + align:start position:0% + + + + align:start position:0% + +since s + + align:start position:0% +since s + + + align:start position:0% +since s +sub 2k converges to s there exists + + align:start position:0% + + + + align:start position:0% + +an m0 natural number so that + + align:start position:0% + + + + align:start position:0% + +all k bigger than or equal to m0 + + align:start position:0% + + + + align:start position:0% + +s of 2k minus s an absolute value is + + align:start position:0% +s of 2k minus s an absolute value is + + + align:start position:0% +s of 2k minus s an absolute value is +less than epsilon right + + align:start position:0% + + + + align:start position:0% + +now + + align:start position:0% +now + + + align:start position:0% +now +we haven't used it all in this proof uh + + align:start position:0% +we haven't used it all in this proof uh + + + align:start position:0% +we haven't used it all in this proof uh +that the xns really converge to zero we + + align:start position:0% +that the xns really converge to zero we + + + align:start position:0% +that the xns really converge to zero we +did use that they were non-negative at + + align:start position:0% +did use that they were non-negative at + + + align:start position:0% +did use that they were non-negative at +one point + + align:start position:0% +one point + + + align:start position:0% +one point +but now this is where we'll use a + + align:start position:0% +but now this is where we'll use a + + + align:start position:0% +but now this is where we'll use a +conversion zero because + + align:start position:0% +conversion zero because + + + align:start position:0% +conversion zero because +you know here's here's the intuition + + align:start position:0% +you know here's here's the intuition + + + align:start position:0% +you know here's here's the intuition +the s sub two k's + + align:start position:0% +the s sub two k's + + + align:start position:0% +the s sub two k's +are converging to something + + align:start position:0% +are converging to something + + + align:start position:0% +are converging to something +so now i just kind of have to look at + + align:start position:0% +so now i just kind of have to look at + + + align:start position:0% +so now i just kind of have to look at +the odd ones i've shown all the even + + align:start position:0% +the odd ones i've shown all the even + + + align:start position:0% +the odd ones i've shown all the even +partial sums converge to s so + + align:start position:0% +partial sums converge to s so + + + align:start position:0% +partial sums converge to s so +if i can show the odd partial sums also + + align:start position:0% +if i can show the odd partial sums also + + + align:start position:0% +if i can show the odd partial sums also +converge to s then essentially i'm done + + align:start position:0% +converge to s then essentially i'm done + + + align:start position:0% +converge to s then essentially i'm done +what's the difference between an even + + align:start position:0% +what's the difference between an even + + + align:start position:0% +what's the difference between an even +partial sum and an odd partial sum + + align:start position:0% +partial sum and an odd partial sum + + + align:start position:0% +partial sum and an odd partial sum +well it's just x to the 2k plus x sub 2k + + align:start position:0% +well it's just x to the 2k plus x sub 2k + + + align:start position:0% +well it's just x to the 2k plus x sub 2k +plus one + + align:start position:0% +plus one + + + align:start position:0% +plus one +which is converging to zero so + + align:start position:0% +which is converging to zero so + + + align:start position:0% +which is converging to zero so +um they don't differ by much + + align:start position:0% +um they don't differ by much + + + align:start position:0% +um they don't differ by much +and that's essentially um + + align:start position:0% +and that's essentially um + + + align:start position:0% +and that's essentially um +that's essentially the whole argument + + align:start position:0% +that's essentially the whole argument + + + align:start position:0% +that's essentially the whole argument +right there + + align:start position:0% +right there + + + align:start position:0% +right there +so since + + align:start position:0% +so since + + + align:start position:0% +so since +x ends converge to zero + + align:start position:0% +x ends converge to zero + + + align:start position:0% +x ends converge to zero +there exists + + align:start position:0% + + + + align:start position:0% + +natural number m sub + + align:start position:0% +natural number m sub + + + align:start position:0% +natural number m sub +one so that for all n bigger than or + + align:start position:0% +one so that for all n bigger than or + + + align:start position:0% +one so that for all n bigger than or +equal to m sub 1 + + align:start position:0% +equal to m sub 1 + + + align:start position:0% +equal to m sub 1 +x of n is less than + + align:start position:0% +x of n is less than + + + align:start position:0% +x of n is less than +epsilon over 2. i should prevent epsilon + + align:start position:0% +epsilon over 2. i should prevent epsilon + + + align:start position:0% +epsilon over 2. i should prevent epsilon +over 2 here + + align:start position:0% + + + + align:start position:0% + +choose m to be + + align:start position:0% +choose m to be + + + align:start position:0% +choose m to be +the maximum of two numbers + + align:start position:0% +the maximum of two numbers + + + align:start position:0% +the maximum of two numbers +two m zero plus one + + align:start position:0% +two m zero plus one + + + align:start position:0% +two m zero plus one +and m one so you'll see why i made these + + align:start position:0% +and m one so you'll see why i made these + + + align:start position:0% +and m one so you'll see why i made these +choices in just a minute + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +suppose m is bigger than or equal to m + + align:start position:0% +suppose m is bigger than or equal to m + + + align:start position:0% +suppose m is bigger than or equal to m +we now want to show that s sub m minus s + + align:start position:0% +we now want to show that s sub m minus s + + + align:start position:0% +we now want to show that s sub m minus s +is less than epsilon in absolute value + + align:start position:0% + + + + align:start position:0% + +so there's two cases if m is even + + align:start position:0% + + + + align:start position:0% + +then + + align:start position:0% +then + + + align:start position:0% +then +m over 2 is bigger than or equal to + + align:start position:0% +m over 2 is bigger than or equal to + + + align:start position:0% +m over 2 is bigger than or equal to +capital m over 2 which is + + align:start position:0% +capital m over 2 which is + + + align:start position:0% +capital m over 2 which is +the max of these if i divide by 2 that's + + align:start position:0% +the max of these if i divide by 2 that's + + + align:start position:0% +the max of these if i divide by 2 that's +certainly bigger than or equal to m0 + + align:start position:0% +certainly bigger than or equal to m0 + + + align:start position:0% +certainly bigger than or equal to m0 +all right and therefore + + align:start position:0% +all right and therefore + + + align:start position:0% +all right and therefore +i use this first inequality s sub m + + align:start position:0% +i use this first inequality s sub m + + + align:start position:0% +i use this first inequality s sub m +minus s + + align:start position:0% +minus s + + + align:start position:0% +minus s +which is equal to s 2 times m over 2 + + align:start position:0% +which is equal to s 2 times m over 2 + + + align:start position:0% +which is equal to s 2 times m over 2 +minus s now m over 2 + + align:start position:0% +minus s now m over 2 + + + align:start position:0% +minus s now m over 2 +is an integer bigger than or equal to m + + align:start position:0% +is an integer bigger than or equal to m + + + align:start position:0% +is an integer bigger than or equal to m +sub 0. + + align:start position:0% +sub 0. + + + align:start position:0% +sub 0. +so i can use this inequality it's less + + align:start position:0% +so i can use this inequality it's less + + + align:start position:0% +so i can use this inequality it's less +than epsilon over two which is less than + + align:start position:0% +than epsilon over two which is less than + + + align:start position:0% +than epsilon over two which is less than +epsilon + + align:start position:0% +epsilon + + + align:start position:0% +epsilon +okay + + align:start position:0% + + + + align:start position:0% + +and now + + align:start position:0% + + + + align:start position:0% + +we do odd + + align:start position:0% + + + + align:start position:0% + +so again m is bigger than or equal to + + align:start position:0% +so again m is bigger than or equal to + + + align:start position:0% +so again m is bigger than or equal to +capital m and there's two cases m even + + align:start position:0% +capital m and there's two cases m even + + + align:start position:0% +capital m and there's two cases m even +and m odd if m is odd + + align:start position:0% + + + + align:start position:0% + +let k be this integer now since m is odd + + align:start position:0% +let k be this integer now since m is odd + + + align:start position:0% +let k be this integer now since m is odd +m minus one is even divided by two + + align:start position:0% +m minus one is even divided by two + + + align:start position:0% +m minus one is even divided by two +that's an integer okay + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +so this is + + align:start position:0% + + + + align:start position:0% + +so m + + align:start position:0% +so m + + + align:start position:0% +so m +equals 2k + + align:start position:0% +equals 2k + + + align:start position:0% +equals 2k +plus 1. + + align:start position:0% + + + + align:start position:0% + +and since m is bigger than or equal to + + align:start position:0% + + + + align:start position:0% + +m0 + + align:start position:0% +m0 + + + align:start position:0% +m0 +this implies a couple of things + + align:start position:0% +this implies a couple of things + + + align:start position:0% +this implies a couple of things +this implies that this integer so + + align:start position:0% +this implies that this integer so + + + align:start position:0% +this implies that this integer so +our m + + align:start position:0% +our m + + + align:start position:0% +our m +this implies that + + align:start position:0% +this implies that + + + align:start position:0% +this implies that +2k plus 1 is bigger than or equal to 2 + + align:start position:0% + + + + align:start position:0% + +so m is just equal to two k plus one so + + align:start position:0% +so m is just equal to two k plus one so + + + align:start position:0% +so m is just equal to two k plus one so +that's bigger than or equal to m which + + align:start position:0% +that's bigger than or equal to m which + + + align:start position:0% +that's bigger than or equal to m which +is bigger than or equal to two m sub + + align:start position:0% +is bigger than or equal to two m sub + + + align:start position:0% +is bigger than or equal to two m sub +zero plus one + + align:start position:0% + + + + align:start position:0% + +and therefore k + + align:start position:0% +and therefore k + + + align:start position:0% +and therefore k +this integer here is bigger than m zero + + align:start position:0% + + + + align:start position:0% + +also + + align:start position:0% + + + + align:start position:0% + +m is bigger than or equal to + + align:start position:0% +m is bigger than or equal to + + + align:start position:0% +m is bigger than or equal to +m sub 1 as well i mean m is bigger than + + align:start position:0% +m sub 1 as well i mean m is bigger than + + + align:start position:0% +m sub 1 as well i mean m is bigger than +or equal to m and m is bigger than or + + align:start position:0% +or equal to m and m is bigger than or + + + align:start position:0% +or equal to m and m is bigger than or +equal to the max of these two things so + + align:start position:0% +equal to the max of these two things so + + + align:start position:0% +equal to the max of these two things so +it's bigger than or equal to m1 + + align:start position:0% + + + + align:start position:0% + +then if i look at s of m + + align:start position:0% +then if i look at s of m + + + align:start position:0% +then if i look at s of m +minus + + align:start position:0% +minus + + + align:start position:0% +minus +s this is equal to + + align:start position:0% +s this is equal to + + + align:start position:0% +s this is equal to +s sub m so + + align:start position:0% +s sub m so + + + align:start position:0% +s sub m so +the nth partial sum + + align:start position:0% +the nth partial sum + + + align:start position:0% +the nth partial sum +is equal to the m minus first partial + + align:start position:0% +is equal to the m minus first partial + + + align:start position:0% +is equal to the m minus first partial +sum plus + + align:start position:0% + + + + align:start position:0% + +the next term + + align:start position:0% +the next term + + + align:start position:0% +the next term +minus s + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +now m minus 1 in terms of the integer k + + align:start position:0% +now m minus 1 in terms of the integer k + + + align:start position:0% +now m minus 1 in terms of the integer k +is equal to 2 + + align:start position:0% +is equal to 2 + + + align:start position:0% +is equal to 2 +times k + + align:start position:0% + + + + align:start position:0% + +and now i'm going to take this s + + align:start position:0% +and now i'm going to take this s + + + align:start position:0% +and now i'm going to take this s +and group it with this guy + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% + + + + align:start position:0% + +so since k + + align:start position:0% +so since k + + + align:start position:0% +so since k +is bigger than or equal to m sub 0 we + + align:start position:0% +is bigger than or equal to m sub 0 we + + + align:start position:0% +is bigger than or equal to m sub 0 we +can use this inequality here + + align:start position:0% +can use this inequality here + + + align:start position:0% +can use this inequality here +after we do the triangle inequality so + + align:start position:0% +after we do the triangle inequality so + + + align:start position:0% +after we do the triangle inequality so +this is less than or equal to s2k minus + + align:start position:0% +this is less than or equal to s2k minus + + + align:start position:0% +this is less than or equal to s2k minus +s + + align:start position:0% +s + + + align:start position:0% +s +plus the absolute value of this thing + + align:start position:0% + + + + align:start position:0% + +so again since k is bigger than or equal + + align:start position:0% +so again since k is bigger than or equal + + + align:start position:0% +so again since k is bigger than or equal +to m sub 0 i can use this + + align:start position:0% +to m sub 0 i can use this + + + align:start position:0% +to m sub 0 i can use this +inequality + + align:start position:0% +inequality + + + align:start position:0% +inequality +to get this is less than epsilon over 2 + + align:start position:0% +to get this is less than epsilon over 2 + + + align:start position:0% +to get this is less than epsilon over 2 +plus + + align:start position:0% +plus + + + align:start position:0% +plus +this guy and since m is bigger than or + + align:start position:0% +this guy and since m is bigger than or + + + align:start position:0% +this guy and since m is bigger than or +equal to + + align:start position:0% +equal to + + + align:start position:0% +equal to +capital m which is bigger than or equal + + align:start position:0% +capital m which is bigger than or equal + + + align:start position:0% +capital m which is bigger than or equal +to capital m sub 1. + + align:start position:0% +to capital m sub 1. + + + align:start position:0% +to capital m sub 1. +i can use this inequality + + align:start position:0% + + + + align:start position:0% + +and this is less than epsilon + + align:start position:0% +and this is less than epsilon + + + align:start position:0% +and this is less than epsilon +okay so + + align:start position:0% +okay so + + + align:start position:0% +okay so +we've done the case of m even or m odd + + align:start position:0% +we've done the case of m even or m odd + + + align:start position:0% +we've done the case of m even or m odd +and bigger than or equal to m so in + + align:start position:0% +and bigger than or equal to m so in + + + align:start position:0% +and bigger than or equal to m so in +summary + + align:start position:0% + + + + align:start position:0% + +we've shown that if m is bigger than or + + align:start position:0% +we've shown that if m is bigger than or + + + align:start position:0% +we've shown that if m is bigger than or +equal to m + + align:start position:0% +equal to m + + + align:start position:0% +equal to m +s of m minus s is less than epsilon and + + align:start position:0% +s of m minus s is less than epsilon and + + + align:start position:0% +s of m minus s is less than epsilon and +therefore + + align:start position:0% +therefore + + + align:start position:0% +therefore +the s of n's converge + + align:start position:0% +the s of n's converge + + + align:start position:0% +the s of n's converge +to s and + + align:start position:0% +to s and + + + align:start position:0% +to s and +i don't think i have enough time to do + + align:start position:0% +i don't think i have enough time to do + + + align:start position:0% +i don't think i have enough time to do +this next theorem + + align:start position:0% +this next theorem + + + align:start position:0% +this next theorem +so we'll stop there \ No newline at end of file diff --git a/ZzMdrYTCPO4.txt b/ZzMdrYTCPO4.txt new file mode 100644 index 0000000000000000000000000000000000000000..011c7d64beb4b474e4b627a5f88cf0d11fb52792 --- /dev/null +++ b/ZzMdrYTCPO4.txt @@ -0,0 +1,7272 @@ +align:start position:0% + +all right so by last Friday we + + align:start position:0% +all right so by last Friday we + + + align:start position:0% +all right so by last Friday we +discovered the electron discovered the + + align:start position:0% +discovered the electron discovered the + + + align:start position:0% +discovered the electron discovered the +nucleus and um the problem then was how + + align:start position:0% +nucleus and um the problem then was how + + + align:start position:0% +nucleus and um the problem then was how +to describe the structure of the atom + + align:start position:0% +to describe the structure of the atom + + + align:start position:0% +to describe the structure of the atom +they knew there was an electron they + + align:start position:0% +they knew there was an electron they + + + align:start position:0% +they knew there was an electron they +knew there was a + + align:start position:0% +knew there was a + + + align:start position:0% +knew there was a +nucleus but exactly how did the electron + + align:start position:0% +nucleus but exactly how did the electron + + + align:start position:0% +nucleus but exactly how did the electron +and the nucleus uh hang + + align:start position:0% +and the nucleus uh hang + + + align:start position:0% +and the nucleus uh hang +together and we talked about + + align:start position:0% +together and we talked about + + + align:start position:0% +together and we talked about +how uh the scientists at that time + + align:start position:0% +how uh the scientists at that time + + + align:start position:0% +how uh the scientists at that time +proposed a classical model where the + + align:start position:0% +proposed a classical model where the + + + align:start position:0% +proposed a classical model where the +interaction between the electron the + + align:start position:0% +interaction between the electron the + + + align:start position:0% +interaction between the electron the +nucleus was of course the kulum + + align:start position:0% +nucleus was of course the kulum + + + align:start position:0% +nucleus was of course the kulum +interaction but where the equations of + + align:start position:0% +interaction but where the equations of + + + align:start position:0% +interaction but where the equations of +motion were Newton's equations of motion + + align:start position:0% +motion were Newton's equations of motion + + + align:start position:0% +motion were Newton's equations of motion +to describe this electron going around + + align:start position:0% +to describe this electron going around + + + align:start position:0% +to describe this electron going around +the nucleus F equal + + align:start position:0% +the nucleus F equal + + + align:start position:0% +the nucleus F equal +Ma and although we didn't show it what + + align:start position:0% +Ma and although we didn't show it what + + + align:start position:0% +Ma and although we didn't show it what +we said was that if we used that Force + + align:start position:0% +we said was that if we used that Force + + + align:start position:0% +we said was that if we used that Force +field the kulon force coupled with + + align:start position:0% +field the kulon force coupled with + + + align:start position:0% +field the kulon force coupled with +Newton's equations of motion and + + align:start position:0% +Newton's equations of motion and + + + align:start position:0% +Newton's equations of motion and +actually you also have to couple them + + align:start position:0% +actually you also have to couple them + + + align:start position:0% +actually you also have to couple them +with some classical electromagnetism + + align:start position:0% +with some classical electromagnetism + + + align:start position:0% +with some classical electromagnetism +which I may not have said but which + + align:start position:0% +which I may not have said but which + + + align:start position:0% +which I may not have said but which +isn't important but if you use those + + align:start position:0% +isn't important but if you use those + + + align:start position:0% +isn't important but if you use those +classical + + align:start position:0% +classical + + + align:start position:0% +classical +ideas to describe how that electron goes + + align:start position:0% +ideas to describe how that electron goes + + + align:start position:0% +ideas to describe how that electron goes +around that nucleus well you would find + + align:start position:0% +around that nucleus well you would find + + + align:start position:0% +around that nucleus well you would find +that in 10 Theus 10 seconds that + + align:start position:0% +that in 10 Theus 10 seconds that + + + align:start position:0% +that in 10 Theus 10 seconds that +electron would be on top of the nucleus + + align:start position:0% +electron would be on top of the nucleus + + + align:start position:0% +electron would be on top of the nucleus +and youd no longer have what we know to + + align:start position:0% +and youd no longer have what we know to + + + align:start position:0% +and youd no longer have what we know to +be the structure of the atom in the + + align:start position:0% +be the structure of the atom in the + + + align:start position:0% +be the structure of the atom in the +sense that you'd no longer have some + + align:start position:0% +sense that you'd no longer have some + + + align:start position:0% +sense that you'd no longer have some +volume where the diameter of that volume + + align:start position:0% +volume where the diameter of that volume + + + align:start position:0% +volume where the diameter of that volume +is on the order of an angstrom or so so + + align:start position:0% +is on the order of an angstrom or so so + + + align:start position:0% +is on the order of an angstrom or so so +the bottom line is that these classical + + align:start position:0% +the bottom line is that these classical + + + align:start position:0% +the bottom line is that these classical +ideas classical mechanics and classical + + align:start position:0% +ideas classical mechanics and classical + + + align:start position:0% +ideas classical mechanics and classical +electromagnetism they just totally fail + + align:start position:0% +electromagnetism they just totally fail + + + align:start position:0% +electromagnetism they just totally fail +to explain the structure of the atom and + + align:start position:0% +to explain the structure of the atom and + + + align:start position:0% +to explain the structure of the atom and +that was the conundrum that the + + align:start position:0% +that was the conundrum that the + + + align:start position:0% +that was the conundrum that the +scientists fac in 1911 this was quite a + + align:start position:0% +scientists fac in 1911 this was quite a + + + align:start position:0% +scientists fac in 1911 this was quite a +a a big problem for the scientific + + align:start position:0% +a a big problem for the scientific + + + align:start position:0% +a a big problem for the scientific +community and was so for about 10 12 13 + + align:start position:0% +community and was so for about 10 12 13 + + + align:start position:0% +community and was so for about 10 12 13 +years all right and of course what fails + + align:start position:0% +years all right and of course what fails + + + align:start position:0% +years all right and of course what fails +are the classical equations of motion + + align:start position:0% +are the classical equations of motion + + + align:start position:0% +are the classical equations of motion +Newton's equations a new kind of + + align:start position:0% +Newton's equations a new kind of + + + align:start position:0% +Newton's equations a new kind of +mechanics is going to have to be + + align:start position:0% +mechanics is going to have to be + + + align:start position:0% +mechanics is going to have to be +invented in order to understand how that + + align:start position:0% +invented in order to understand how that + + + align:start position:0% +invented in order to understand how that +atom is bound or how the electron in the + + align:start position:0% +atom is bound or how the electron in the + + + align:start position:0% +atom is bound or how the electron in the +nucleus are bound how it's stable + + align:start position:0% +nucleus are bound how it's stable + + + align:start position:0% +nucleus are bound how it's stable +but + + align:start position:0% +but + + + align:start position:0% +but +now + + align:start position:0% +now + + + align:start position:0% +now +historically the actual clues for why + + align:start position:0% +historically the actual clues for why + + + align:start position:0% +historically the actual clues for why +the electron didn't collapse into the + + align:start position:0% +the electron didn't collapse into the + + + align:start position:0% +the electron didn't collapse into the +nucleus those Clues actually came from a + + align:start position:0% +nucleus those Clues actually came from a + + + align:start position:0% +nucleus those Clues actually came from a +very different area of discussion and + + align:start position:0% +very different area of discussion and + + + align:start position:0% +very different area of discussion and +that area of discussion is this wave + + align:start position:0% +that area of discussion is this wave + + + align:start position:0% +that area of discussion is this wave +particle duality of light and + + align:start position:0% +particle duality of light and + + + align:start position:0% +particle duality of light and +matter it was certainly long believed + + align:start position:0% +matter it was certainly long believed + + + align:start position:0% +matter it was certainly long believed +that matter with its particle like + + align:start position:0% +that matter with its particle like + + + align:start position:0% +that matter with its particle like +Behavior was distinct from Light which + + align:start position:0% +Behavior was distinct from Light which + + + align:start position:0% +Behavior was distinct from Light which +was this kind of transmission of energy + + align:start position:0% +was this kind of transmission of energy + + + align:start position:0% +was this kind of transmission of energy +uh through + + align:start position:0% +uh through + + + align:start position:0% +uh through +space but in the late 1800s in early + + align:start position:0% +space but in the late 1800s in early + + + align:start position:0% +space but in the late 1800s in early +1900s there began to be made some + + align:start position:0% +1900s there began to be made some + + + align:start position:0% +1900s there began to be made some +observations that seemed to suggest that + + align:start position:0% +observations that seemed to suggest that + + + align:start position:0% +observations that seemed to suggest that +well you know maybe this boundary + + align:start position:0% +well you know maybe this boundary + + + align:start position:0% +well you know maybe this boundary +between matter and Its particle-like + + align:start position:0% +between matter and Its particle-like + + + align:start position:0% +between matter and Its particle-like +Behavior and light and its wav likee + + align:start position:0% +Behavior and light and its wav likee + + + align:start position:0% +Behavior and light and its wav likee +Behavior well maybe that boundary wasn't + + align:start position:0% +Behavior well maybe that boundary wasn't + + + align:start position:0% +Behavior well maybe that boundary wasn't +so rigid after + + align:start position:0% +so rigid after + + + align:start position:0% +so rigid after +all and in fact what we're going to see + + align:start position:0% +all and in fact what we're going to see + + + align:start position:0% +all and in fact what we're going to see +is that radiation or light exhibits both + + align:start position:0% +is that radiation or light exhibits both + + + align:start position:0% +is that radiation or light exhibits both +wav like behavior and particle like + + align:start position:0% +wav like behavior and particle like + + + align:start position:0% +wav like behavior and particle like +behavior and it depends on the kind of + + align:start position:0% +behavior and it depends on the kind of + + + align:start position:0% +behavior and it depends on the kind of +experiment that you do which one of + + align:start position:0% +experiment that you do which one of + + + align:start position:0% +experiment that you do which one of +those properties you + + align:start position:0% +those properties you + + + align:start position:0% +those properties you +see and then consequently matter matter + + align:start position:0% +see and then consequently matter matter + + + align:start position:0% +see and then consequently matter matter +it also exhibits both particle like + + align:start position:0% +it also exhibits both particle like + + + align:start position:0% +it also exhibits both particle like +behavior and wav like behavior and again + + align:start position:0% +behavior and wav like behavior and again + + + align:start position:0% +behavior and wav like behavior and again +it depends depends on the particular + + align:start position:0% +it depends depends on the particular + + + align:start position:0% +it depends depends on the particular +experiment you do as to which one of + + align:start position:0% +experiment you do as to which one of + + + align:start position:0% +experiment you do as to which one of +those properties you actually + + align:start position:0% +those properties you actually + + + align:start position:0% +those properties you actually +observe all right so what we're going to + + align:start position:0% +observe all right so what we're going to + + + align:start position:0% +observe all right so what we're going to +do right now is we're actually going to + + align:start position:0% +do right now is we're actually going to + + + align:start position:0% +do right now is we're actually going to +set aside the discussion of the + + align:start position:0% +set aside the discussion of the + + + align:start position:0% +set aside the discussion of the +structure of the atom how the electron + + align:start position:0% +structure of the atom how the electron + + + align:start position:0% +structure of the atom how the electron +and the nucleus are bound together how + + align:start position:0% +and the nucleus are bound together how + + + align:start position:0% +and the nucleus are bound together how +in the world do they remain stable we're + + align:start position:0% +in the world do they remain stable we're + + + align:start position:0% +in the world do they remain stable we're +going to set that discussion + + align:start position:0% +going to set that discussion + + + align:start position:0% +going to set that discussion +aside and we're not going to pick it up + + align:start position:0% +aside and we're not going to pick it up + + + align:start position:0% +aside and we're not going to pick it up +until next Monday and and the reason for + + align:start position:0% +until next Monday and and the reason for + + + align:start position:0% +until next Monday and and the reason for +it is because in order to proceed with + + align:start position:0% +it is because in order to proceed with + + + align:start position:0% +it is because in order to proceed with +that discussion we actually have to go + + align:start position:0% +that discussion we actually have to go + + + align:start position:0% +that discussion we actually have to go +through this other set of + + align:start position:0% +through this other set of + + + align:start position:0% +through this other set of +observations sorry this other set of + + align:start position:0% +observations sorry this other set of + + + align:start position:0% +observations sorry this other set of +observ that was my my my pointer I was + + align:start position:0% +observ that was my my my pointer I was + + + align:start position:0% +observ that was my my my pointer I was +zapping some of you here sorry um we + + align:start position:0% +zapping some of you here sorry um we + + + align:start position:0% +zapping some of you here sorry um we +have to go and look at these other + + align:start position:0% +have to go and look at these other + + + align:start position:0% +have to go and look at these other +observations this discussion about the + + align:start position:0% +observations this discussion about the + + + align:start position:0% +observations this discussion about the +wave particle duality of light and + + align:start position:0% +wave particle duality of light and + + + align:start position:0% +wave particle duality of light and +matter in order to get the clues in + + align:start position:0% +matter in order to get the clues in + + + align:start position:0% +matter in order to get the clues in +order for us to make progress about + + align:start position:0% +order for us to make progress about + + + align:start position:0% +order for us to make progress about +about what next big leap we got to make + + align:start position:0% +about what next big leap we got to make + + + align:start position:0% +about what next big leap we got to make +right in order to talk about the + + align:start position:0% +right in order to talk about the + + + align:start position:0% +right in order to talk about the +structure of the atom all right so we're + + align:start position:0% +structure of the atom all right so we're + + + align:start position:0% +structure of the atom all right so we're +going to change subjects or it's going + + align:start position:0% +going to change subjects or it's going + + + align:start position:0% +going to change subjects or it's going +to look like we're changing subjects but + + align:start position:0% +to look like we're changing subjects but + + + align:start position:0% +to look like we're changing subjects but +we're going to use the results of our + + align:start position:0% +we're going to use the results of our + + + align:start position:0% +we're going to use the results of our +discussions in the next three days to + + align:start position:0% +discussions in the next three days to + + + align:start position:0% +discussions in the next three days to +come back to talk about the structure of + + align:start position:0% +come back to talk about the structure of + + + align:start position:0% +come back to talk about the structure of +the atom all right okay so then the + + align:start position:0% +the atom all right okay so then the + + + align:start position:0% +the atom all right okay so then the +first thing we got to talk about is + + align:start position:0% +first thing we got to talk about is + + + align:start position:0% +first thing we got to talk about is +we're going to talk about light and + + align:start position:0% +we're going to talk about light and + + + align:start position:0% +we're going to talk about light and +we're going to talk about the wave like + + align:start position:0% +we're going to talk about the wave like + + + align:start position:0% +we're going to talk about the wave like +nature to uh + + align:start position:0% +nature to uh + + + align:start position:0% +nature to uh +radiation and uh since that's really uh + + align:start position:0% +radiation and uh since that's really uh + + + align:start position:0% +radiation and uh since that's really uh +probably most intuitive so let's let's + + align:start position:0% +probably most intuitive so let's let's + + + align:start position:0% +probably most intuitive so let's let's +do that + + align:start position:0% +do that + + + align:start position:0% +do that +okay so uh can we uh dim the front + + align:start position:0% +okay so uh can we uh dim the front + + + align:start position:0% +okay so uh can we uh dim the front +lights here oh okay uh I could do that + + align:start position:0% +lights here oh okay uh I could do that + + + align:start position:0% +lights here oh okay uh I could do that +too + + align:start position:0% + + + + align:start position:0% + +maybe got it all right I got it + + align:start position:0% +maybe got it all right I got it + + + align:start position:0% +maybe got it all right I got it +Christine thank you all all right so um + + align:start position:0% +Christine thank you all all right so um + + + align:start position:0% +Christine thank you all all right so um +properties of waves well what are waves + + align:start position:0% +properties of waves well what are waves + + + align:start position:0% +properties of waves well what are waves +well you are familiar with that right + + align:start position:0% +well you are familiar with that right + + + align:start position:0% +well you are familiar with that right +waves are a periodic variation of some + + align:start position:0% +waves are a periodic variation of some + + + align:start position:0% +waves are a periodic variation of some +uh quantity in the case of water waves + + align:start position:0% +uh quantity in the case of water waves + + + align:start position:0% +uh quantity in the case of water waves +right we have the periodic variation of + + align:start position:0% +right we have the periodic variation of + + + align:start position:0% +right we have the periodic variation of +the height of water so at some points in + + align:start position:0% +the height of water so at some points in + + + align:start position:0% +the height of water so at some points in +space here the height of the water is + + align:start position:0% +space here the height of the water is + + + align:start position:0% +space here the height of the water is +high at some point the height of the + + align:start position:0% +high at some point the height of the + + + align:start position:0% +high at some point the height of the +water is low and there's some average + + align:start position:0% +water is low and there's some average + + + align:start position:0% +water is low and there's some average +level here all right a uh sound wve well + + align:start position:0% +level here all right a uh sound wve well + + + align:start position:0% +level here all right a uh sound wve well +Soundwave is a periodic variation of the + + align:start position:0% +Soundwave is a periodic variation of the + + + align:start position:0% +Soundwave is a periodic variation of the +density of air at some points in Space + + align:start position:0% +density of air at some points in Space + + + align:start position:0% +density of air at some points in Space +the air is very dense at other points in + + align:start position:0% +the air is very dense at other points in + + + align:start position:0% +the air is very dense at other points in +Space the air is is not so dense and + + align:start position:0% +Space the air is is not so dense and + + + align:start position:0% +Space the air is is not so dense and +then there's an average level + + align:start position:0% +then there's an average level + + + align:start position:0% +then there's an average level +here well what we're going to do is + + align:start position:0% +here well what we're going to do is + + + align:start position:0% +here well what we're going to do is +we're going to set this average level + + align:start position:0% +we're going to set this average level + + + align:start position:0% +we're going to set this average level +here to a + + align:start position:0% +here to a + + + align:start position:0% +here to a +zero and then consequently our + + align:start position:0% +zero and then consequently our + + + align:start position:0% +zero and then consequently our +waves are going to have a positive + + align:start position:0% +waves are going to have a positive + + + align:start position:0% +waves are going to have a positive +amplitude that is measured from this + + align:start position:0% +amplitude that is measured from this + + + align:start position:0% +amplitude that is measured from this +zero level up that's a positive + + align:start position:0% +zero level up that's a positive + + + align:start position:0% +zero level up that's a positive +amplitude and measured from the zero + + align:start position:0% +amplitude and measured from the zero + + + align:start position:0% +amplitude and measured from the zero +level down that's our negative amplitude + + align:start position:0% +level down that's our negative amplitude + + + align:start position:0% +level down that's our negative amplitude +all right so these waves are going to + + align:start position:0% +all right so these waves are going to + + + align:start position:0% +all right so these waves are going to +have positive and negative amplitude + + align:start position:0% +have positive and negative amplitude + + + align:start position:0% +have positive and negative amplitude +that's going to be very important in how + + align:start position:0% +that's going to be very important in how + + + align:start position:0% +that's going to be very important in how +they actually + + align:start position:0% +they actually + + + align:start position:0% +they actually +behave now what we're going to do oh + + align:start position:0% +behave now what we're going to do oh + + + align:start position:0% +behave now what we're going to do oh +okay and so what is light well light is + + align:start position:0% +okay and so what is light well light is + + + align:start position:0% +okay and so what is light well light is +a periodic + + align:start position:0% +a periodic + + + align:start position:0% +a periodic +variation of an electric field and + + align:start position:0% +variation of an electric field and + + + align:start position:0% +variation of an electric field and +that's what I plot here Electric El + + align:start position:0% +that's what I plot here Electric El + + + align:start position:0% +that's what I plot here Electric El +field versus distance and you can see + + align:start position:0% +field versus distance and you can see + + + align:start position:0% +field versus distance and you can see +it's varying in + + align:start position:0% +it's varying in + + + align:start position:0% +it's varying in +intensity but uh what exactly is an + + align:start position:0% +intensity but uh what exactly is an + + + align:start position:0% +intensity but uh what exactly is an +electric + + align:start position:0% +electric + + + align:start position:0% +electric +field let's just think about that for a + + align:start position:0% +field let's just think about that for a + + + align:start position:0% +field let's just think about that for a +moment suppose I take a uh paral two + + align:start position:0% +moment suppose I take a uh paral two + + + align:start position:0% +moment suppose I take a uh paral two +parallel plates so here's one here's + + align:start position:0% +parallel plates so here's one here's + + + align:start position:0% +parallel plates so here's one here's +another and I'm going to put a uh + + align:start position:0% +another and I'm going to put a uh + + + align:start position:0% +another and I'm going to put a uh +negative potential on that top plate and + + align:start position:0% +negative potential on that top plate and + + + align:start position:0% +negative potential on that top plate and +a positive potential on the bottom plate + + align:start position:0% +a positive potential on the bottom plate + + + align:start position:0% +a positive potential on the bottom plate +and what is operating then between this + + align:start position:0% +and what is operating then between this + + + align:start position:0% +and what is operating then between this +negatively charged plate and the + + align:start position:0% +negatively charged plate and the + + + align:start position:0% +negatively charged plate and the +positively charged plate is the kulum + + align:start position:0% +positively charged plate is the kulum + + + align:start position:0% +positively charged plate is the kulum +interaction and the electric field then + + align:start position:0% +interaction and the electric field then + + + align:start position:0% +interaction and the electric field then +is the space through which that kolum + + align:start position:0% +is the space through which that kolum + + + align:start position:0% +is the space through which that kolum +Force operates so that electric field + + align:start position:0% +Force operates so that electric field + + + align:start position:0% +Force operates so that electric field +here is this space through which this + + align:start position:0% +here is this space through which this + + + align:start position:0% +here is this space through which this +kulum force is operating and by + + align:start position:0% +kulum force is operating and by + + + align:start position:0% +kulum force is operating and by +convention we're going to say that it's + + align:start position:0% +convention we're going to say that it's + + + align:start position:0% +convention we're going to say that it's +operating here in this uh in this + + align:start position:0% +operating here in this uh in this + + + align:start position:0% +operating here in this uh in this +orientation so in other words if I put a + + align:start position:0% +orientation so in other words if I put a + + + align:start position:0% +orientation so in other words if I put a +positive charge in between these two + + align:start position:0% +positive charge in between these two + + + align:start position:0% +positive charge in between these two +plates in this electric field this space + + align:start position:0% +plates in this electric field this space + + + align:start position:0% +plates in this electric field this space +through which the kolon force is + + align:start position:0% +through which the kolon force is + + + align:start position:0% +through which the kolon force is +operating well what's going to happen is + + align:start position:0% +operating well what's going to happen is + + + align:start position:0% +operating well what's going to happen is +that this positive charge is going to + + align:start position:0% +that this positive charge is going to + + + align:start position:0% +that this positive charge is going to +drift to the negatively charged + + align:start position:0% +drift to the negatively charged + + + align:start position:0% +drift to the negatively charged +plate but if I turn the geometry around + + align:start position:0% +plate but if I turn the geometry around + + + align:start position:0% +plate but if I turn the geometry around +right if I put the negatively charged + + align:start position:0% +right if I put the negatively charged + + + align:start position:0% +right if I put the negatively charged +plate on the the bottom using this + + align:start position:0% +plate on the the bottom using this + + + align:start position:0% +plate on the the bottom using this +coordinate system and I now put that + + align:start position:0% +coordinate system and I now put that + + + align:start position:0% +coordinate system and I now put that +positive charge in that electric field + + align:start position:0% +positive charge in that electric field + + + align:start position:0% +positive charge in that electric field +it's going to drift to the negatively + + align:start position:0% +it's going to drift to the negatively + + + align:start position:0% +it's going to drift to the negatively +charged plate again but it's going to + + align:start position:0% +charged plate again but it's going to + + + align:start position:0% +charged plate again but it's going to +move in this coordinate system + + align:start position:0% +move in this coordinate system + + + align:start position:0% +move in this coordinate system +down so this electric field has not + + align:start position:0% +down so this electric field has not + + + align:start position:0% +down so this electric field has not +only magnitude because you can imagine + + align:start position:0% +only magnitude because you can imagine + + + align:start position:0% +only magnitude because you can imagine +the larger the potential difference + + align:start position:0% +the larger the potential difference + + + align:start position:0% +the larger the potential difference +between these two plates the larger the + + align:start position:0% +between these two plates the larger the + + + align:start position:0% +between these two plates the larger the +magnitude of the electric field but that + + align:start position:0% +magnitude of the electric field but that + + + align:start position:0% +magnitude of the electric field but that +electric field also has Direction it's + + align:start position:0% +electric field also has Direction it's + + + align:start position:0% +electric field also has Direction it's +pointed in one way or the other and + + align:start position:0% +pointed in one way or the other and + + + align:start position:0% +pointed in one way or the other and +that's what's represented here on my + + align:start position:0% +that's what's represented here on my + + + align:start position:0% +that's what's represented here on my +diagram of the electric field versus + + align:start position:0% +diagram of the electric field versus + + + align:start position:0% +diagram of the electric field versus +distance you can see that right here the + + align:start position:0% +distance you can see that right here the + + + align:start position:0% +distance you can see that right here the +electric field the magnitude of it + + align:start position:0% +electric field the magnitude of it + + + align:start position:0% +electric field the magnitude of it +starts out small it increases continues + + align:start position:0% +starts out small it increases continues + + + align:start position:0% +starts out small it increases continues +to increase till we get a maximum and + + align:start position:0% +to increase till we get a maximum and + + + align:start position:0% +to increase till we get a maximum and +then it starts getting smaller it getss + + align:start position:0% +then it starts getting smaller it getss + + + align:start position:0% +then it starts getting smaller it getss +smaller and goes all the way to zero at + + align:start position:0% +smaller and goes all the way to zero at + + + align:start position:0% +smaller and goes all the way to zero at +which point then it turns around and the + + align:start position:0% +which point then it turns around and the + + + align:start position:0% +which point then it turns around and the +magnitude begins to increase in the + + align:start position:0% +magnitude begins to increase in the + + + align:start position:0% +magnitude begins to increase in the +opposite direction and again it becomes + + align:start position:0% +opposite direction and again it becomes + + + align:start position:0% +opposite direction and again it becomes +a maximum in the opposite direction and + + align:start position:0% +a maximum in the opposite direction and + + + align:start position:0% +a maximum in the opposite direction and +then turns around goes to zero and + + align:start position:0% +then turns around goes to zero and + + + align:start position:0% +then turns around goes to zero and +continues so it's a periodic variation + + align:start position:0% +continues so it's a periodic variation + + + align:start position:0% +continues so it's a periodic variation +here of an electric + + align:start position:0% +here of an electric + + + align:start position:0% +here of an electric +field and so what that means is that if + + align:start position:0% +field and so what that means is that if + + + align:start position:0% +field and so what that means is that if +we put some charge say at this point in + + align:start position:0% +we put some charge say at this point in + + + align:start position:0% +we put some charge say at this point in +space it would be pulled one way and if + + align:start position:0% +space it would be pulled one way and if + + + align:start position:0% +space it would be pulled one way and if +we put it at this point in space it + + align:start position:0% +we put it at this point in space it + + + align:start position:0% +we put it at this point in space it +would be pulled in another way and if we + + align:start position:0% +would be pulled in another way and if we + + + align:start position:0% +would be pulled in another way and if we +put it right here at zero it's not going + + align:start position:0% +put it right here at zero it's not going + + + align:start position:0% +put it right here at zero it's not going +anywhere + + align:start position:0% +anywhere + + + align:start position:0% +anywhere +okay okay now what I've showed you here + + align:start position:0% +okay okay now what I've showed you here + + + align:start position:0% +okay okay now what I've showed you here +is a periodic variation of an electric + + align:start position:0% +is a periodic variation of an electric + + + align:start position:0% +is a periodic variation of an electric +field it is also the case that whenever + + align:start position:0% +field it is also the case that whenever + + + align:start position:0% +field it is also the case that whenever +we have an electric field we also have a + + align:start position:0% +we have an electric field we also have a + + + align:start position:0% +we have an electric field we also have a +magnetic field that is actually + + align:start position:0% +magnetic field that is actually + + + align:start position:0% +magnetic field that is actually +perpendicular to this electric field + + align:start position:0% +perpendicular to this electric field + + + align:start position:0% +perpendicular to this electric field +here but since that magnetic field is + + align:start position:0% +here but since that magnetic field is + + + align:start position:0% +here but since that magnetic field is +going to have all the same + + align:start position:0% +going to have all the same + + + align:start position:0% +going to have all the same +characteristics as the electric field + + align:start position:0% +characteristics as the electric field + + + align:start position:0% +characteristics as the electric field +for from our point of discussion here + + align:start position:0% +for from our point of discussion here + + + align:start position:0% +for from our point of discussion here +I'm not going to talk about it but + + align:start position:0% +I'm not going to talk about it but + + + align:start position:0% +I'm not going to talk about it but +you're going to see this a lot next + + align:start position:0% +you're going to see this a lot next + + + align:start position:0% +you're going to see this a lot next +semester in 802 all right so we're just + + align:start position:0% +semester in 802 all right so we're just + + + align:start position:0% +semester in 802 all right so we're just +going to characterize here the electric + + align:start position:0% +going to characterize here the electric + + + align:start position:0% +going to characterize here the electric +field all right + + align:start position:0% +field all right + + + align:start position:0% +field all right +and the way we're going to characterize + + align:start position:0% +and the way we're going to characterize + + + align:start position:0% +and the way we're going to characterize +it is to put a functional form to + + align:start position:0% +it is to put a functional form to + + + align:start position:0% +it is to put a functional form to +it so I'm plotting the electric field + + align:start position:0% +it so I'm plotting the electric field + + + align:start position:0% +it so I'm plotting the electric field +here as a function of + + align:start position:0% + + + + align:start position:0% + +X and the functional form that we're + + align:start position:0% +X and the functional form that we're + + + align:start position:0% +X and the functional form that we're +going to use to characterize it is a * + + align:start position:0% +going to use to characterize it is a * + + + align:start position:0% +going to use to characterize it is a * +cine 2 pix over Lambda a cosine + + align:start position:0% +cine 2 pix over Lambda a cosine + + + align:start position:0% +cine 2 pix over Lambda a cosine +function now what I want you to + + align:start position:0% +function now what I want you to + + + align:start position:0% +function now what I want you to +notice is that this field + + align:start position:0% +notice is that this field + + + align:start position:0% +notice is that this field +oscillates between a positive amplitude + + align:start position:0% +oscillates between a positive amplitude + + + align:start position:0% +oscillates between a positive amplitude +a and a negative amplitude a or a minus + + align:start position:0% +a and a negative amplitude a or a minus + + + align:start position:0% +a and a negative amplitude a or a minus +a right so this coefficient right out in + + align:start position:0% +a right so this coefficient right out in + + + align:start position:0% +a right so this coefficient right out in +front right here that + + align:start position:0% +front right here that + + + align:start position:0% +front right here that +coefficient physically is the maximum + + align:start position:0% +coefficient physically is the maximum + + + align:start position:0% +coefficient physically is the maximum +amplitude so if you were to be given a + + align:start position:0% +amplitude so if you were to be given a + + + align:start position:0% +amplitude so if you were to be given a +waveform that has a number out here in + + align:start position:0% +waveform that has a number out here in + + + align:start position:0% +waveform that has a number out here in +front of a cosine X hey that number + + align:start position:0% +front of a cosine X hey that number + + + align:start position:0% +front of a cosine X hey that number +immediately the physical significance of + + align:start position:0% +immediately the physical significance of + + + align:start position:0% +immediately the physical significance of +it is that it's the maximum + + align:start position:0% +it is that it's the maximum + + + align:start position:0% +it is that it's the maximum +amplitude the other parameter beside the + + align:start position:0% +amplitude the other parameter beside the + + + align:start position:0% +amplitude the other parameter beside the +amplitude here the maximum amplitude + + align:start position:0% +amplitude here the maximum amplitude + + + align:start position:0% +amplitude here the maximum amplitude +that we use to characterize this cosine + + align:start position:0% +that we use to characterize this cosine + + + align:start position:0% +that we use to characterize this cosine +function is the + + align:start position:0% +function is the + + + align:start position:0% +function is the +wavelength the wavelength is the + + align:start position:0% +wavelength the wavelength is the + + + align:start position:0% +wavelength the wavelength is the +distance between two successive Maxima + + align:start position:0% +distance between two successive Maxima + + + align:start position:0% +distance between two successive Maxima +or two successive minimum right and that + + align:start position:0% +or two successive minimum right and that + + + align:start position:0% +or two successive minimum right and that +wavelength here comes in the argument of + + align:start position:0% +wavelength here comes in the argument of + + + align:start position:0% +wavelength here comes in the argument of +that Co sign function so again if you + + align:start position:0% +that Co sign function so again if you + + + align:start position:0% +that Co sign function so again if you +were to be given a form that had a + + align:start position:0% +were to be given a form that had a + + + align:start position:0% +were to be given a form that had a +number time cosine time a number time x + + align:start position:0% +number time cosine time a number time x + + + align:start position:0% +number time cosine time a number time x +well that number is equal to 2 pi over + + align:start position:0% +well that number is equal to 2 pi over + + + align:start position:0% +well that number is equal to 2 pi over +Lambda and so almost by inspection you + + align:start position:0% +Lambda and so almost by inspection you + + + align:start position:0% +Lambda and so almost by inspection you +can figure out what the wavelength is + + align:start position:0% +can figure out what the wavelength is + + + align:start position:0% +can figure out what the wavelength is +just from the functional form of that + + align:start position:0% +just from the functional form of that + + + align:start position:0% +just from the functional form of that +cosine + + align:start position:0% +cosine + + + align:start position:0% +cosine +function all right and because the + + align:start position:0% +function all right and because the + + + align:start position:0% +function all right and because the +argument is 2 pix over + + align:start position:0% +argument is 2 pix over + + + align:start position:0% +argument is 2 pix over +Lambda well you can easily see that you + + align:start position:0% +Lambda well you can easily see that you + + + align:start position:0% +Lambda well you can easily see that you +get the maximum amplitude a here + + align:start position:0% +get the maximum amplitude a here + + + align:start position:0% +get the maximum amplitude a here +whenever X is an integral multiple of + + align:start position:0% +whenever X is an integral multiple of + + + align:start position:0% +whenever X is an integral multiple of +Lambda so when X is Lambda 2 Lambda 3 + + align:start position:0% +Lambda so when X is Lambda 2 Lambda 3 + + + align:start position:0% +Lambda so when X is Lambda 2 Lambda 3 +Lambda or minus Lambda minus 2 Lambda or + + align:start position:0% +Lambda or minus Lambda minus 2 Lambda or + + + align:start position:0% +Lambda or minus Lambda minus 2 Lambda or +zero all right so most of that I think + + align:start position:0% +zero all right so most of that I think + + + align:start position:0% +zero all right so most of that I think +you're familiar + + align:start position:0% +you're familiar + + + align:start position:0% +you're familiar +with all right but not only is light or + + align:start position:0% +with all right but not only is light or + + + align:start position:0% +with all right but not only is light or +formally electromagnetic radiation not + + align:start position:0% +formally electromagnetic radiation not + + + align:start position:0% +formally electromagnetic radiation not +only is that simply a periodic variation + + align:start position:0% +only is that simply a periodic variation + + + align:start position:0% +only is that simply a periodic variation +of the electric or magnetic + + align:start position:0% +of the electric or magnetic + + + align:start position:0% +of the electric or magnetic +field but light is + + align:start position:0% +field but light is + + + align:start position:0% +field but light is +also a um periodic variation in + + align:start position:0% +also a um periodic variation in + + + align:start position:0% +also a um periodic variation in +time that is light propagates it moves + + align:start position:0% +time that is light propagates it moves + + + align:start position:0% +time that is light propagates it moves +so for + + align:start position:0% +so for + + + align:start position:0% +so for +example here's a uh cosine functional + + align:start position:0% +example here's a uh cosine functional + + + align:start position:0% +example here's a uh cosine functional +form at some snapshot in T equals z and + + align:start position:0% +form at some snapshot in T equals z and + + + align:start position:0% +form at some snapshot in T equals z and +I put a star here on the maximum of uh + + align:start position:0% +I put a star here on the maximum of uh + + + align:start position:0% +I put a star here on the maximum of uh +one of these U Maxima all + + align:start position:0% +one of these U Maxima all + + + align:start position:0% +one of these U Maxima all +right now what happens is that this wave + + align:start position:0% +right now what happens is that this wave + + + align:start position:0% +right now what happens is that this wave +moves it + + align:start position:0% +moves it + + + align:start position:0% +moves it +propagates and the time it takes that + + align:start position:0% +propagates and the time it takes that + + + align:start position:0% +propagates and the time it takes that +wave to move one wavelength just like it + + align:start position:0% +wave to move one wavelength just like it + + + align:start position:0% +wave to move one wavelength just like it +did in that very short clip the time it + + align:start position:0% +did in that very short clip the time it + + + align:start position:0% +did in that very short clip the time it +takes to move + + align:start position:0% +takes to move + + + align:start position:0% +takes to move +one wavelength so that this Maxima that + + align:start position:0% +one wavelength so that this Maxima that + + + align:start position:0% +one wavelength so that this Maxima that +was here is now there is what we call a + + align:start position:0% +was here is now there is what we call a + + + align:start position:0% +was here is now there is what we call a +period one period is the time it takes + + align:start position:0% +period one period is the time it takes + + + align:start position:0% +period one period is the time it takes +the wave to move one + + align:start position:0% +the wave to move one + + + align:start position:0% +the wave to move one +wavelength and we can also characterize + + align:start position:0% +wavelength and we can also characterize + + + align:start position:0% +wavelength and we can also characterize +the + + align:start position:0% +the + + + align:start position:0% +the +period by the frequency of the + + align:start position:0% +period by the frequency of the + + + align:start position:0% +period by the frequency of the +wave that frequency is is new here and + + align:start position:0% +wave that frequency is is new here and + + + align:start position:0% +wave that frequency is is new here and +the period is one over new and the + + align:start position:0% +the period is one over new and the + + + align:start position:0% +the period is one over new and the +frequency then is the number of cycles + + align:start position:0% +frequency then is the number of cycles + + + align:start position:0% +frequency then is the number of cycles +per second so another words if I were + + align:start position:0% +per second so another words if I were + + + align:start position:0% +per second so another words if I were +sitting right here at x equals z okay + + align:start position:0% +sitting right here at x equals z okay + + + align:start position:0% +sitting right here at x equals z okay +and I'm just watching the wave come by + + align:start position:0% +and I'm just watching the wave come by + + + align:start position:0% +and I'm just watching the wave come by +me the frequency is the number of + + align:start position:0% +me the frequency is the number of + + + align:start position:0% +me the frequency is the number of +times that a Maxima passes by me per + + align:start position:0% +times that a Maxima passes by me per + + + align:start position:0% +times that a Maxima passes by me per +second or the number of times a minim + + align:start position:0% +second or the number of times a minim + + + align:start position:0% +second or the number of times a minim +passes by me per second that's the + + align:start position:0% +passes by me per second that's the + + + align:start position:0% +passes by me per second that's the +frequency okay I'll make that a little + + align:start position:0% +frequency okay I'll make that a little + + + align:start position:0% +frequency okay I'll make that a little +bit more obvious in just a + + align:start position:0% +bit more obvious in just a + + + align:start position:0% +bit more obvious in just a +moment + + align:start position:0% +moment + + + align:start position:0% +moment +frequency I said is a number of cycles + + align:start position:0% +frequency I said is a number of cycles + + + align:start position:0% +frequency I said is a number of cycles +per second but the unit that we use to + + align:start position:0% +per second but the unit that we use to + + + align:start position:0% +per second but the unit that we use to +uh convey frequency something called the + + align:start position:0% +uh convey frequency something called the + + + align:start position:0% +uh convey frequency something called the +Hertz HZ Hertz and formally it is just + + align:start position:0% +Hertz HZ Hertz and formally it is just + + + align:start position:0% +Hertz HZ Hertz and formally it is just +inverse seconds right we drop the number + + align:start position:0% +inverse seconds right we drop the number + + + align:start position:0% +inverse seconds right we drop the number +of Cycles but the number of Cycles in + + align:start position:0% +of Cycles but the number of Cycles in + + + align:start position:0% +of Cycles but the number of Cycles in +that unit is + + align:start position:0% + + + + align:start position:0% + +implied all right so now suppose the + + align:start position:0% +implied all right so now suppose the + + + align:start position:0% +implied all right so now suppose the +following I said that this electric + + align:start position:0% +following I said that this electric + + + align:start position:0% +following I said that this electric +field has uh magnitude and it also has + + align:start position:0% +field has uh magnitude and it also has + + + align:start position:0% +field has uh magnitude and it also has +direction right so suppose I take an + + align:start position:0% +direction right so suppose I take an + + + align:start position:0% +direction right so suppose I take an +electric field or an electromagnetic + + align:start position:0% +electric field or an electromagnetic + + + align:start position:0% +electric field or an electromagnetic +radiation that has a frequency of one + + align:start position:0% +radiation that has a frequency of one + + + align:start position:0% +radiation that has a frequency of one +Hertz one cycle per second + + align:start position:0% +Hertz one cycle per second + + + align:start position:0% +Hertz one cycle per second +and right here at x equals 0 I stick + + align:start position:0% +and right here at x equals 0 I stick + + + align:start position:0% +and right here at x equals 0 I stick +somehow I pin an elect uh an electron + + align:start position:0% +somehow I pin an elect uh an electron + + + align:start position:0% +somehow I pin an elect uh an electron +right there okay it can't move anywhere + + align:start position:0% +right there okay it can't move anywhere + + + align:start position:0% +right there okay it can't move anywhere +it's just + + align:start position:0% +it's just + + + align:start position:0% +it's just +stuck what's going to happen to that + + align:start position:0% +stuck what's going to happen to that + + + align:start position:0% +stuck what's going to happen to that +electron as this radiation of one Hertz + + align:start position:0% +electron as this radiation of one Hertz + + + align:start position:0% +electron as this radiation of one Hertz +passes by well what's going to happen is + + align:start position:0% +passes by well what's going to happen is + + + align:start position:0% +passes by well what's going to happen is +that that electron is going to be now + + align:start position:0% +that that electron is going to be now + + + align:start position:0% +that that electron is going to be now +since it start at the top it's going to + + align:start position:0% +since it start at the top it's going to + + + align:start position:0% +since it start at the top it's going to +be pulled down and then it's going to be + + align:start position:0% +be pulled down and then it's going to be + + + align:start position:0% +be pulled down and then it's going to be +pushed back up to its original position + + align:start position:0% +pushed back up to its original position + + + align:start position:0% +pushed back up to its original position +every 1 second because this frequency + + align:start position:0% +every 1 second because this frequency + + + align:start position:0% +every 1 second because this frequency +here is 1 Hertz and because this + + align:start position:0% +here is 1 Hertz and because this + + + align:start position:0% +here is 1 Hertz and because this +electric field has both magnitude and it + + align:start position:0% +electric field has both magnitude and it + + + align:start position:0% +electric field has both magnitude and it +has Direction all right so now we're + + align:start position:0% +has Direction all right so now we're + + + align:start position:0% +has Direction all right so now we're +going to let this electric field go by + + align:start position:0% +going to let this electric field go by + + + align:start position:0% +going to let this electric field go by +the electron gets pushed down and pulled + + align:start position:0% +the electron gets pushed down and pulled + + + align:start position:0% +the electron gets pushed down and pulled +back up once every second all right so + + align:start position:0% +back up once every second all right so + + + align:start position:0% +back up once every second all right so +hopefully that makes the idea of + + align:start position:0% +hopefully that makes the idea of + + + align:start position:0% +hopefully that makes the idea of +frequency a little bit more uh real to + + align:start position:0% +frequency a little bit more uh real to + + + align:start position:0% +frequency a little bit more uh real to +to + + align:start position:0% +to + + + align:start position:0% +to +you + + align:start position:0% +you + + + align:start position:0% +you +okay but not only do we have this + + align:start position:0% +okay but not only do we have this + + + align:start position:0% +okay but not only do we have this +periodic variation in + + align:start position:0% +periodic variation in + + + align:start position:0% +periodic variation in +time but we also have the wave propagate + + align:start position:0% +time but we also have the wave propagate + + + align:start position:0% +time but we also have the wave propagate +here in space you know that wave moves + + align:start position:0% +here in space you know that wave moves + + + align:start position:0% +here in space you know that wave moves +this way or this way or this way + + align:start position:0% +this way or this way or this way + + + align:start position:0% +this way or this way or this way +okay and so what we want to know is the + + align:start position:0% +okay and so what we want to know is the + + + align:start position:0% +okay and so what we want to know is the +speed of that + + align:start position:0% +speed of that + + + align:start position:0% +speed of that +propagation now speed is always distance + + align:start position:0% +propagation now speed is always distance + + + align:start position:0% +propagation now speed is always distance +traveled over the time + + align:start position:0% +traveled over the time + + + align:start position:0% +traveled over the time +elapsed and um what we've already seen + + align:start position:0% +elapsed and um what we've already seen + + + align:start position:0% +elapsed and um what we've already seen +is that this wave will move by one + + align:start position:0% +is that this wave will move by one + + + align:start position:0% +is that this wave will move by one +wavelength in the time period of a + + align:start position:0% +wavelength in the time period of a + + + align:start position:0% +wavelength in the time period of a +period okay that is we already saw that + + align:start position:0% +period okay that is we already saw that + + + align:start position:0% +period okay that is we already saw that +this wave will move here one wavelength + + align:start position:0% +this wave will move here one wavelength + + + align:start position:0% +this wave will move here one wavelength +from here to + + align:start position:0% +from here to + + + align:start position:0% +from here to +here in the time period of a period or + + align:start position:0% +here in the time period of a period or + + + align:start position:0% +here in the time period of a period or +one over new okay that's the time elapse + + align:start position:0% +one over new okay that's the time elapse + + + align:start position:0% +one over new okay that's the time elapse +so the speed of this propagation the + + align:start position:0% +so the speed of this propagation the + + + align:start position:0% +so the speed of this propagation the +speed with which it's moving is the + + align:start position:0% +speed with which it's moving is the + + + align:start position:0% +speed with which it's moving is the +distance traveled which is Lambda right + + align:start position:0% +distance traveled which is Lambda right + + + align:start position:0% +distance traveled which is Lambda right +divided by the time + + align:start position:0% +divided by the time + + + align:start position:0% +divided by the time +elapsed which is one over new and + + align:start position:0% +elapsed which is one over new and + + + align:start position:0% +elapsed which is one over new and +therefore the speed of that propagation + + align:start position:0% +therefore the speed of that propagation + + + align:start position:0% +therefore the speed of that propagation +is Lambda time + + align:start position:0% +is Lambda time + + + align:start position:0% +is Lambda time +U all right so these are the important + + align:start position:0% +U all right so these are the important + + + align:start position:0% +U all right so these are the important +Concepts here we have the speed of the + + align:start position:0% +Concepts here we have the speed of the + + + align:start position:0% +Concepts here we have the speed of the +propagation Lambda Time new we + + align:start position:0% +propagation Lambda Time new we + + + align:start position:0% +propagation Lambda Time new we +characterized our wave in terms of + + align:start position:0% +characterized our wave in terms of + + + align:start position:0% +characterized our wave in terms of +amplitudes in terms of wavelengths and + + align:start position:0% +amplitudes in terms of wavelengths and + + + align:start position:0% +amplitudes in terms of wavelengths and +in terms of frequency those are the + + align:start position:0% +in terms of frequency those are the + + + align:start position:0% +in terms of frequency those are the +quantities that are important that you + + align:start position:0% +quantities that are important that you + + + align:start position:0% +quantities that are important that you +really do have to understand very + + align:start position:0% + + + + align:start position:0% + +well okay + + align:start position:0% +well okay + + + align:start position:0% +well okay +now I think that you're all familiar + + align:start position:0% +now I think that you're all familiar + + + align:start position:0% +now I think that you're all familiar +with the fact that all electromagnetic + + align:start position:0% +with the fact that all electromagnetic + + + align:start position:0% +with the fact that all electromagnetic +radiation has a constant speed right + + align:start position:0% +radiation has a constant speed right + + + align:start position:0% +radiation has a constant speed right +that + + align:start position:0% +that + + + align:start position:0% +that +is the + + align:start position:0% +is the + + + align:start position:0% +is the +wavelength of electromagnetic radiation + + align:start position:0% +wavelength of electromagnetic radiation + + + align:start position:0% +wavelength of electromagnetic radiation +times its + + align:start position:0% +times its + + + align:start position:0% +times its +frequency is always equal to this number + + align:start position:0% +frequency is always equal to this number + + + align:start position:0% +frequency is always equal to this number +it's about 3 * 10 8 + + align:start position:0% +it's about 3 * 10 8 + + + align:start position:0% +it's about 3 * 10 8 +m/s and we call it we abbreviate it C + + align:start position:0% +m/s and we call it we abbreviate it C + + + align:start position:0% +m/s and we call it we abbreviate it C +the speed of light so no matter what + + align:start position:0% +the speed of light so no matter what + + + align:start position:0% +the speed of light so no matter what +frequency you have of + + align:start position:0% +frequency you have of + + + align:start position:0% +frequency you have of +radiation the + + align:start position:0% +radiation the + + + align:start position:0% +radiation the +corresponding wavelength is such that + + align:start position:0% +corresponding wavelength is such that + + + align:start position:0% +corresponding wavelength is such that +the wavelength times the frequency is as + + align:start position:0% +the wavelength times the frequency is as + + + align:start position:0% +the wavelength times the frequency is as +constant is this value of + + align:start position:0% +constant is this value of + + + align:start position:0% +constant is this value of +c and of course it is the differ + + align:start position:0% +c and of course it is the differ + + + align:start position:0% +c and of course it is the differ +different frequencies or the different + + align:start position:0% +different frequencies or the different + + + align:start position:0% +different frequencies or the different +wavelengths of electromagnetic radiation + + align:start position:0% +wavelengths of electromagnetic radiation + + + align:start position:0% +wavelengths of electromagnetic radiation +that gives it its different characters + + align:start position:0% +that gives it its different characters + + + align:start position:0% +that gives it its different characters +even though it all has the same speed of + + align:start position:0% +even though it all has the same speed of + + + align:start position:0% +even though it all has the same speed of +propagation right and that's + + align:start position:0% + + + + align:start position:0% + +um those different kinds of uh + + align:start position:0% +um those different kinds of uh + + + align:start position:0% +um those different kinds of uh +properties so to + + align:start position:0% +properties so to + + + align:start position:0% +properties so to +speak is this um spectrum of + + align:start position:0% +speak is this um spectrum of + + + align:start position:0% +speak is this um spectrum of +electromagnetic + + align:start position:0% +electromagnetic + + + align:start position:0% +electromagnetic +radiation okay so electromagnetic + + align:start position:0% +radiation okay so electromagnetic + + + align:start position:0% +radiation okay so electromagnetic +radiation is an infinitely wide + + align:start position:0% +radiation is an infinitely wide + + + align:start position:0% +radiation is an infinitely wide +spectrum it's + + align:start position:0% +spectrum it's + + + align:start position:0% +spectrum it's +uh very long wavelengths right we have + + align:start position:0% +uh very long wavelengths right we have + + + align:start position:0% +uh very long wavelengths right we have +what are known as radial + + align:start position:0% +what are known as radial + + + align:start position:0% +what are known as radial +waves at very short wavelengths we have + + align:start position:0% +waves at very short wavelengths we have + + + align:start position:0% +waves at very short wavelengths we have +what we know are known as gamma rays or + + align:start position:0% +what we know are known as gamma rays or + + + align:start position:0% +what we know are known as gamma rays or +cosmic rays + + align:start position:0% +cosmic rays + + + align:start position:0% +cosmic rays +right the long wavelengths the radial + + align:start position:0% +right the long wavelengths the radial + + + align:start position:0% +right the long wavelengths the radial +waves are going to have a relatively low + + align:start position:0% +waves are going to have a relatively low + + + align:start position:0% +waves are going to have a relatively low +frequency the high W the short + + align:start position:0% +frequency the high W the short + + + align:start position:0% +frequency the high W the short +wavelengths are going to have a + + align:start position:0% +wavelengths are going to have a + + + align:start position:0% +wavelengths are going to have a +relatively high + + align:start position:0% +relatively high + + + align:start position:0% +relatively high +frequency why because the product of + + align:start position:0% +frequency why because the product of + + + align:start position:0% +frequency why because the product of +Lambda times new always has to be + + align:start position:0% +Lambda times new always has to be + + + align:start position:0% +Lambda times new always has to be +C all + + align:start position:0% +C all + + + align:start position:0% +C all +right okay well we're not going to go + + align:start position:0% +right okay well we're not going to go + + + align:start position:0% +right okay well we're not going to go +very much in detail here all right + + align:start position:0% +very much in detail here all right + + + align:start position:0% +very much in detail here all right +except maybe to tell you the following + + align:start position:0% +except maybe to tell you the following + + + align:start position:0% +except maybe to tell you the following +see this microwave range here well + + align:start position:0% +see this microwave range here well + + + align:start position:0% +see this microwave range here well +molecules when they absorb microwave + + align:start position:0% +molecules when they absorb microwave + + + align:start position:0% +molecules when they absorb microwave +radiation they + + align:start position:0% +radiation they + + + align:start position:0% +radiation they +rotate right see infrared radiation when + + align:start position:0% +rotate right see infrared radiation when + + + align:start position:0% +rotate right see infrared radiation when +molecules absorb infrared radiation they + + align:start position:0% +molecules absorb infrared radiation they + + + align:start position:0% +molecules absorb infrared radiation they +vibrate see the visible and UltraViolet + + align:start position:0% +vibrate see the visible and UltraViolet + + + align:start position:0% +vibrate see the visible and UltraViolet +range when molecules absorb visible or + + align:start position:0% +range when molecules absorb visible or + + + align:start position:0% +range when molecules absorb visible or +UV radiation they put an electron into a + + align:start position:0% +UV radiation they put an electron into a + + + align:start position:0% +UV radiation they put an electron into a +higher energy + + align:start position:0% +higher energy + + + align:start position:0% +higher energy +State and often times once you do that + + align:start position:0% +State and often times once you do that + + + align:start position:0% +State and often times once you do that +of course the electron wants to relax to + + align:start position:0% +of course the electron wants to relax to + + + align:start position:0% +of course the electron wants to relax to +a lower energy State and so it relaxes + + align:start position:0% +a lower energy State and so it relaxes + + + align:start position:0% +a lower energy State and so it relaxes +by emitting a photon and that's how you + + align:start position:0% +by emitting a photon and that's how you + + + align:start position:0% +by emitting a photon and that's how you +see fluorescents or + + align:start position:0% +see fluorescents or + + + align:start position:0% +see fluorescents or +phosphorescence but it's usually a + + align:start position:0% +phosphorescence but it's usually a + + + align:start position:0% +phosphorescence but it's usually a +result of the absorption of visible or + + align:start position:0% +result of the absorption of visible or + + + align:start position:0% +result of the absorption of visible or +UV + + align:start position:0% +UV + + + align:start position:0% +UV +radiation although it is also possible + + align:start position:0% +radiation although it is also possible + + + align:start position:0% +radiation although it is also possible +for a molecule to absorb some x-ray + + align:start position:0% +for a molecule to absorb some x-ray + + + align:start position:0% +for a molecule to absorb some x-ray +radiation and see that kind of + + align:start position:0% +radiation and see that kind of + + + align:start position:0% +radiation and see that kind of +fluorescence too and we'll talk about it + + align:start position:0% +fluorescence too and we'll talk about it + + + align:start position:0% +fluorescence too and we'll talk about it +but a little bit later on we're going to + + align:start position:0% +but a little bit later on we're going to + + + align:start position:0% +but a little bit later on we're going to +talk about molecules absorbing x-ray + + align:start position:0% +talk about molecules absorbing x-ray + + + align:start position:0% +talk about molecules absorbing x-ray +radiation and kicking out an electron + + align:start position:0% +radiation and kicking out an electron + + + align:start position:0% +radiation and kicking out an electron +and we're going to use that to figure + + align:start position:0% +and we're going to use that to figure + + + align:start position:0% +and we're going to use that to figure +out how strongly bound electrons are to + + align:start position:0% +out how strongly bound electrons are to + + + align:start position:0% +out how strongly bound electrons are to +uh in atoms or how strongly bound they + + align:start position:0% +uh in atoms or how strongly bound they + + + align:start position:0% +uh in atoms or how strongly bound they +are in molecules all right okay but + + align:start position:0% +are in molecules all right okay but + + + align:start position:0% +are in molecules all right okay but +that's all I'll say about that right now + + align:start position:0% +that's all I'll say about that right now + + + align:start position:0% +that's all I'll say about that right now +what you're responsible for is you're + + align:start position:0% +what you're responsible for is you're + + + align:start position:0% +what you're responsible for is you're +responsible in knowing that microwaves + + align:start position:0% +responsible in knowing that microwaves + + + align:start position:0% +responsible in knowing that microwaves +have longer wavelengths than gamma rays + + align:start position:0% +have longer wavelengths than gamma rays + + + align:start position:0% +have longer wavelengths than gamma rays +or cosmic rays all right you are + + align:start position:0% +or cosmic rays all right you are + + + align:start position:0% +or cosmic rays all right you are +responsible for knowing the relative + + align:start position:0% +responsible for knowing the relative + + + align:start position:0% +responsible for knowing the relative +wavelengths here of uh these different + + align:start position:0% +wavelengths here of uh these different + + + align:start position:0% +wavelengths here of uh these different +kinds of radiation every MIT uh student + + align:start position:0% +kinds of radiation every MIT uh student + + + align:start position:0% +kinds of radiation every MIT uh student +should know that all right of course + + align:start position:0% +should know that all right of course + + + align:start position:0% +should know that all right of course +there's a very narrow range here a + + align:start position:0% +there's a very narrow range here a + + + align:start position:0% +there's a very narrow range here a +visible + + align:start position:0% +visible + + + align:start position:0% +visible +radiation that our I is sensitive + + align:start position:0% +radiation that our I is sensitive + + + align:start position:0% +radiation that our I is sensitive +to at the very long wavelengths is red + + align:start position:0% +to at the very long wavelengths is red + + + align:start position:0% +to at the very long wavelengths is red +at the very short wavelengths is blue + + align:start position:0% +at the very short wavelengths is blue + + + align:start position:0% +at the very short wavelengths is blue +and purple again you need to know that + + align:start position:0% +and purple again you need to know that + + + align:start position:0% +and purple again you need to know that +red has a longer wavelength than blue or + + align:start position:0% +red has a longer wavelength than blue or + + + align:start position:0% +red has a longer wavelength than blue or +purple all + + align:start position:0% +purple all + + + align:start position:0% +purple all +right all right so what I've done right + + align:start position:0% +right all right so what I've done right + + + align:start position:0% +right all right so what I've done right +now is really just to + + align:start position:0% +now is really just to + + + align:start position:0% +now is really just to +um tell you that light is an + + align:start position:0% +um tell you that light is an + + + align:start position:0% +um tell you that light is an +electromagnetic radiation characterize + + align:start position:0% +electromagnetic radiation characterize + + + align:start position:0% +electromagnetic radiation characterize +it the way I put a functional form to a + + align:start position:0% +it the way I put a functional form to a + + + align:start position:0% +it the way I put a functional form to a +cosine characterize it by frequency + + align:start position:0% +cosine characterize it by frequency + + + align:start position:0% +cosine characterize it by frequency +wavelength we talked about speed of + + align:start position:0% +wavelength we talked about speed of + + + align:start position:0% +wavelength we talked about speed of +propagation what I haven't done yet is I + + align:start position:0% +propagation what I haven't done yet is I + + + align:start position:0% +propagation what I haven't done yet is I +haven't proved to you that light is in + + align:start position:0% +haven't proved to you that light is in + + + align:start position:0% +haven't proved to you that light is in +fact or light behaves like a wave and + + align:start position:0% +fact or light behaves like a wave and + + + align:start position:0% +fact or light behaves like a wave and +that's what we're going to do now and + + align:start position:0% +that's what we're going to do now and + + + align:start position:0% +that's what we're going to do now and +the experiment we're going to do is the + + align:start position:0% +the experiment we're going to do is the + + + align:start position:0% +the experiment we're going to do is the +same experiment that a gentleman called + + align:start position:0% +same experiment that a gentleman called + + + align:start position:0% +same experiment that a gentleman called +young did in the late 1800s + + align:start position:0% +young did in the late 1800s + + + align:start position:0% +young did in the late 1800s +that seem to really demonstrate without + + align:start position:0% +that seem to really demonstrate without + + + align:start position:0% +that seem to really demonstrate without +a question that light is a wave or light + + align:start position:0% +a question that light is a wave or light + + + align:start position:0% +a question that light is a wave or light +behaves like a + + align:start position:0% +behaves like a + + + align:start position:0% +behaves like a +wave we're going to do what's called the + + align:start position:0% +wave we're going to do what's called the + + + align:start position:0% +wave we're going to do what's called the +two slit + + align:start position:0% +two slit + + + align:start position:0% +two slit +experiment and in this experiment I'm + + align:start position:0% +experiment and in this experiment I'm + + + align:start position:0% +experiment and in this experiment I'm +going to take radiation of a single + + align:start position:0% +going to take radiation of a single + + + align:start position:0% +going to take radiation of a single +wavelength so we're going to make the + + align:start position:0% +wavelength so we're going to make the + + + align:start position:0% +wavelength so we're going to make the +radiation + + align:start position:0% +radiation + + + align:start position:0% +radiation +monochromatic and uh that wavelength + + align:start position:0% +monochromatic and uh that wavelength + + + align:start position:0% +monochromatic and uh that wavelength +that we're going to use is 600 6,000 330 + + align:start position:0% +that we're going to use is 600 6,000 330 + + + align:start position:0% +that we're going to use is 600 6,000 330 +angstroms or 633 + + align:start position:0% +angstroms or 633 + + + align:start position:0% +angstroms or 633 +nanometers and we're going to put in + + align:start position:0% +nanometers and we're going to put in + + + align:start position:0% +nanometers and we're going to put in +front of that Source we're going to put + + align:start position:0% +front of that Source we're going to put + + + align:start position:0% +front of that Source we're going to put +a piece of uh it's going to be a thin uh + + align:start position:0% +a piece of uh it's going to be a thin uh + + + align:start position:0% +a piece of uh it's going to be a thin uh +piece of metal or the could be any + + align:start position:0% +piece of metal or the could be any + + + align:start position:0% +piece of metal or the could be any +material but we're going to poke two + + align:start position:0% +material but we're going to poke two + + + align:start position:0% +material but we're going to poke two +holes in it we're going to make two + + align:start position:0% +holes in it we're going to make two + + + align:start position:0% +holes in it we're going to make two +little + + align:start position:0% +little + + + align:start position:0% +little +slits and + + align:start position:0% +slits and + + + align:start position:0% +slits and +naively what you might expect is that if + + align:start position:0% +naively what you might expect is that if + + + align:start position:0% +naively what you might expect is that if +you have a screen back here that kind of + + align:start position:0% +you have a screen back here that kind of + + + align:start position:0% +you have a screen back here that kind of +uh images this radiat + + align:start position:0% +uh images this radiat + + + align:start position:0% +uh images this radiat +what you might expect is that the the + + align:start position:0% +what you might expect is that the the + + + align:start position:0% +what you might expect is that the the +spots on the screen right directly + + align:start position:0% +spots on the screen right directly + + + align:start position:0% +spots on the screen right directly +opposite these two slits well these are + + align:start position:0% +opposite these two slits well these are + + + align:start position:0% +opposite these two slits well these are +the two spots that are going to light up + + align:start position:0% +the two spots that are going to light up + + + align:start position:0% +the two spots that are going to light up +on the screen that's where you're going + + align:start position:0% +on the screen that's where you're going + + + align:start position:0% +on the screen that's where you're going +to see the image because after all light + + align:start position:0% +to see the image because after all light + + + align:start position:0% +to see the image because after all light +travels in straight lines that's where + + align:start position:0% +travels in straight lines that's where + + + align:start position:0% +travels in straight lines that's where +you should see those two spots so the + + align:start position:0% +you should see those two spots so the + + + align:start position:0% +you should see those two spots so the +slits here are 0.02 in from each other + + align:start position:0% +slits here are 0.02 in from each other + + + align:start position:0% +slits here are 0.02 in from each other +these two spots ought to be .02 in 0.02 + + align:start position:0% +these two spots ought to be .02 in 0.02 + + + align:start position:0% +these two spots ought to be .02 in 0.02 +in separated from each + + align:start position:0% +in separated from each + + + align:start position:0% +in separated from each +other but of course uh when you do that + + align:start position:0% +other but of course uh when you do that + + + align:start position:0% +other but of course uh when you do that +experiment and Christine is actually + + align:start position:0% +experiment and Christine is actually + + + align:start position:0% +experiment and Christine is actually +going to do that experiment right right + + align:start position:0% +going to do that experiment right right + + + align:start position:0% +going to do that experiment right right +now for us I think there it is on the + + align:start position:0% +now for us I think there it is on the + + + align:start position:0% +now for us I think there it is on the +sideboard you can sort of see + + align:start position:0% +sideboard you can sort of see + + + align:start position:0% +sideboard you can sort of see +it okay she's holding + + align:start position:0% +it okay she's holding + + + align:start position:0% +it okay she's holding +it all right well what you can see + + align:start position:0% +it all right well what you can see + + + align:start position:0% +it all right well what you can see +here is that we don't see just two + + align:start position:0% +here is that we don't see just two + + + align:start position:0% +here is that we don't see just two +bright spots but what we see are a bunch + + align:start position:0% +bright spots but what we see are a bunch + + + align:start position:0% +bright spots but what we see are a bunch +of spots here the brightest one happens + + align:start position:0% +of spots here the brightest one happens + + + align:start position:0% +of spots here the brightest one happens +to be right in the center of these two + + align:start position:0% +to be right in the center of these two + + + align:start position:0% +to be right in the center of these two +slits and then there's darkness and then + + align:start position:0% +slits and then there's darkness and then + + + align:start position:0% +slits and then there's darkness and then +there's a bright spot and darkness and a + + align:start position:0% +there's a bright spot and darkness and a + + + align:start position:0% +there's a bright spot and darkness and a +bright spot etc etc we see lots of + + align:start position:0% +bright spot etc etc we see lots of + + + align:start position:0% +bright spot etc etc we see lots of +different bright spots on the screen not + + align:start position:0% +different bright spots on the screen not + + + align:start position:0% +different bright spots on the screen not +just two directly opposite + + align:start position:0% +just two directly opposite + + + align:start position:0% +just two directly opposite +the openings of the slits all + + align:start position:0% +the openings of the slits all + + + align:start position:0% +the openings of the slits all +right okay so and this is just then a + + align:start position:0% +right okay so and this is just then a + + + align:start position:0% +right okay so and this is just then a +cartoon of uh approximately what it is + + align:start position:0% +cartoon of uh approximately what it is + + + align:start position:0% +cartoon of uh approximately what it is +we see with um in real life so CH + + align:start position:0% +we see with um in real life so CH + + + align:start position:0% +we see with um in real life so CH +Christine's up there in the projection + + align:start position:0% +Christine's up there in the projection + + + align:start position:0% +Christine's up there in the projection +booth holding a helium neon laser uh + + align:start position:0% +booth holding a helium neon laser uh + + + align:start position:0% +booth holding a helium neon laser uh +Behind These two slits separated by + + align:start position:0% +Behind These two slits separated by + + + align:start position:0% +Behind These two slits separated by +point2 Ines + + align:start position:0% +point2 Ines + + + align:start position:0% +point2 Ines +right + + align:start position:0% +right + + + align:start position:0% +right +okay well so what's going on here + + align:start position:0% +okay well so what's going on here + + + align:start position:0% +okay well so what's going on here +can we can we understand uh what's the + + align:start position:0% +can we can we understand uh what's the + + + align:start position:0% +can we can we understand uh what's the +origin of these lots of different bright + + align:start position:0% +origin of these lots of different bright + + + align:start position:0% +origin of these lots of different bright +spots in this two slit + + align:start position:0% +spots in this two slit + + + align:start position:0% +spots in this two slit +experiment and actually if we were to + + align:start position:0% +experiment and actually if we were to + + + align:start position:0% +experiment and actually if we were to +measure that uh the distance here should + + align:start position:0% +measure that uh the distance here should + + + align:start position:0% +measure that uh the distance here should +be about 3 cmers between those bright + + align:start position:0% +be about 3 cmers between those bright + + + align:start position:0% +be about 3 cmers between those bright +spots okay well what's going on well + + align:start position:0% +spots okay well what's going on well + + + align:start position:0% +spots okay well what's going on well +what's going on is this + + align:start position:0% +what's going on is this + + + align:start position:0% +what's going on is this +waves waves have the property called + + align:start position:0% +waves waves have the property called + + + align:start position:0% +waves waves have the property called +superposition that is if I take one + + align:start position:0% +superposition that is if I take one + + + align:start position:0% +superposition that is if I take one +wave but then I take a second + + align:start position:0% + + + + align:start position:0% + +wave and I put that second + + align:start position:0% +wave and I put that second + + + align:start position:0% +wave and I put that second +wave in the same space the actual same + + align:start position:0% +wave in the same space the actual same + + + align:start position:0% +wave in the same space the actual same +space as the first wave and I arranged + + align:start position:0% +space as the first wave and I arranged + + + align:start position:0% +space as the first wave and I arranged +the two waves such that the maximum of + + align:start position:0% +the two waves such that the maximum of + + + align:start position:0% +the two waves such that the maximum of +both waves or the minimum of both waves + + align:start position:0% +both waves or the minimum of both waves + + + align:start position:0% +both waves or the minimum of both waves +is at the same position well the prop + + align:start position:0% +is at the same position well the prop + + + align:start position:0% +is at the same position well the prop +property of waves is that these two + + align:start position:0% +property of waves is that these two + + + align:start position:0% +property of waves is that these two +waves add up they + + align:start position:0% +waves add up they + + + align:start position:0% +waves add up they +superimpose they superimpose to make a + + align:start position:0% +superimpose they superimpose to make a + + + align:start position:0% +superimpose they superimpose to make a +wave that now has the amplitude of twice + + align:start position:0% +wave that now has the amplitude of twice + + + align:start position:0% +wave that now has the amplitude of twice +the amplitude of each of those + + align:start position:0% +the amplitude of each of those + + + align:start position:0% +the amplitude of each of those +waves and that's the condition that we + + align:start position:0% +waves and that's the condition that we + + + align:start position:0% +waves and that's the condition that we +call constructive interference but we + + align:start position:0% +call constructive interference but we + + + align:start position:0% +call constructive interference but we +have to have the two waves at the same + + align:start position:0% +have to have the two waves at the same + + + align:start position:0% +have to have the two waves at the same +place and space and the two Maxima have + + align:start position:0% +place and space and the two Maxima have + + + align:start position:0% +place and space and the two Maxima have +to be in the exact same place in space + + align:start position:0% +to be in the exact same place in space + + + align:start position:0% +to be in the exact same place in space +but conversely we can also take the + + align:start position:0% +but conversely we can also take the + + + align:start position:0% +but conversely we can also take the +wave and um bring in another wave but we + + align:start position:0% +wave and um bring in another wave but we + + + align:start position:0% +wave and um bring in another wave but we +can move that other wave + + align:start position:0% +can move that other wave + + + align:start position:0% +can move that other wave +over such that the maximum of one of the + + align:start position:0% +over such that the maximum of one of the + + + align:start position:0% +over such that the maximum of one of the +waves is at the same place in space as + + align:start position:0% +waves is at the same place in space as + + + align:start position:0% +waves is at the same place in space as +the minimum of the other wave in this + + align:start position:0% +the minimum of the other wave in this + + + align:start position:0% +the minimum of the other wave in this +case these two waves are out of phase + + align:start position:0% +case these two waves are out of phase + + + align:start position:0% +case these two waves are out of phase +and when we add them up hey there'll be + + align:start position:0% +and when we add them up hey there'll be + + + align:start position:0% +and when we add them up hey there'll be +nothing this is destructive interference + + align:start position:0% +nothing this is destructive interference + + + align:start position:0% +nothing this is destructive interference +why well because we have positive + + align:start position:0% +why well because we have positive + + + align:start position:0% +why well because we have positive +amplitudes and negative amplitudes they + + align:start position:0% +amplitudes and negative amplitudes they + + + align:start position:0% +amplitudes and negative amplitudes they +cancel to give us nothing destructive + + align:start position:0% +cancel to give us nothing destructive + + + align:start position:0% +cancel to give us nothing destructive +interference okay and um there's a + + align:start position:0% +interference okay and um there's a + + + align:start position:0% +interference okay and um there's a +website here in the University of + + align:start position:0% +website here in the University of + + + align:start position:0% +website here in the University of +Colorado that + + align:start position:0% +Colorado that + + + align:start position:0% +Colorado that +uh lets you um take uh two waves and + + align:start position:0% +uh lets you um take uh two waves and + + + align:start position:0% +uh lets you um take uh two waves and +superimpose them could I uh I need to I + + align:start position:0% +superimpose them could I uh I need to I + + + align:start position:0% +superimpose them could I uh I need to I +need to play with it okay um + + align:start position:0% +need to play with it okay um + + + align:start position:0% +need to play with it okay um +that's all right I'm down here all right + + align:start position:0% +that's all right I'm down here all right + + + align:start position:0% +that's all right I'm down here all right +what I'm going to do is I'm going to um + + align:start position:0% +what I'm going to do is I'm going to um + + + align:start position:0% +what I'm going to do is I'm going to um +make it so that uh these two waves have + + align:start position:0% +make it so that uh these two waves have + + + align:start position:0% +make it so that uh these two waves have +the same + + align:start position:0% + + + + align:start position:0% + +frequency and uh or the same wavelength + + align:start position:0% +frequency and uh or the same wavelength + + + align:start position:0% +frequency and uh or the same wavelength +and the same amplitude right so it's + + align:start position:0% +and the same amplitude right so it's + + + align:start position:0% +and the same amplitude right so it's +what I'm doing here is I'm adding this + + align:start position:0% +what I'm doing here is I'm adding this + + + align:start position:0% +what I'm doing here is I'm adding this +wave I'm adding this wave right here to + + align:start position:0% +wave I'm adding this wave right here to + + + align:start position:0% +wave I'm adding this wave right here to +this wave and the result is shown here + + align:start position:0% +this wave and the result is shown here + + + align:start position:0% +this wave and the result is shown here +and what you can't see is that the + + align:start position:0% +and what you can't see is that the + + + align:start position:0% +and what you can't see is that the +amplitude down here that amplitude is + + align:start position:0% +amplitude down here that amplitude is + + + align:start position:0% +amplitude down here that amplitude is +twice that of these two all right + + align:start position:0% +twice that of these two all right + + + align:start position:0% +twice that of these two all right +there's a two there but of course what I + + align:start position:0% +there's a two there but of course what I + + + align:start position:0% +there's a two there but of course what I +can do is I can move this wave + + align:start position:0% +can do is I can move this wave + + + align:start position:0% +can do is I can move this wave +over such that the two waves are now at + + align:start position:0% +over such that the two waves are now at + + + align:start position:0% +over such that the two waves are now at +the same place in space sort + + align:start position:0% +the same place in space sort + + + align:start position:0% +the same place in space sort +of uh where the maximum and the + + align:start position:0% +of uh where the maximum and the + + + align:start position:0% +of uh where the maximum and the +Minima are at the same place in space + + align:start position:0% +Minima are at the same place in space + + + align:start position:0% +Minima are at the same place in space +and exactly cancel them and I'm not + + align:start position:0% +and exactly cancel them and I'm not + + + align:start position:0% +and exactly cancel them and I'm not +having such a great time doing this here + + align:start position:0% +having such a great time doing this here + + + align:start position:0% +having such a great time doing this here +but I know you can do it because I've + + align:start position:0% +but I know you can do it because I've + + + align:start position:0% +but I know you can do it because I've +done it + + align:start position:0% +done it + + + align:start position:0% +done it +before okay and you can see that that + + align:start position:0% +before okay and you can see that that + + + align:start position:0% +before okay and you can see that that +the resulting amplitude is zero and of + + align:start position:0% +the resulting amplitude is zero and of + + + align:start position:0% +the resulting amplitude is zero and of +course then you can go home and you can + + align:start position:0% +course then you can go home and you can + + + align:start position:0% +course then you can go home and you can +play all you want with this make all + + align:start position:0% +play all you want with this make all + + + align:start position:0% +play all you want with this make all +kinds of different + + align:start position:0% +kinds of different + + + align:start position:0% +kinds of different +waveforms I'm trying to change the + + align:start position:0% +waveforms I'm trying to change the + + + align:start position:0% +waveforms I'm trying to change the +amplitude here it's I've done before but + + align:start position:0% +amplitude here it's I've done before but + + + align:start position:0% +amplitude here it's I've done before but +I can't right now grab the red grab the + + align:start position:0% +I can't right now grab the red grab the + + + align:start position:0% +I can't right now grab the red grab the +red ball Maybe + + align:start position:0% +red ball Maybe + + + align:start position:0% +red ball Maybe +all right but + + align:start position:0% +all right but + + + align:start position:0% +all right but +uh all right so you can do whatever + + align:start position:0% +uh all right so you can do whatever + + + align:start position:0% +uh all right so you can do whatever +waveform you want + + align:start position:0% +waveform you want + + + align:start position:0% +waveform you want +to all right so you get the idea here + + align:start position:0% +to all right so you get the idea here + + + align:start position:0% +to all right so you get the idea here +with + + align:start position:0% +with + + + align:start position:0% +with +superposition all right well let's uh so + + align:start position:0% +superposition all right well let's uh so + + + align:start position:0% +superposition all right well let's uh so +that's a characteristic of waves they + + align:start position:0% +that's a characteristic of waves they + + + align:start position:0% +that's a characteristic of waves they +have positive negative amplitudes they + + align:start position:0% +have positive negative amplitudes they + + + align:start position:0% +have positive negative amplitudes they +add and they cancel depending on the + + align:start position:0% +add and they cancel depending on the + + + align:start position:0% +add and they cancel depending on the +relative positions in + + align:start position:0% +relative positions in + + + align:start position:0% +relative positions in +space but now let's talk a little bit + + align:start position:0% +space but now let's talk a little bit + + + align:start position:0% +space but now let's talk a little bit +more about this uh pattern that we saw + + align:start position:0% +more about this uh pattern that we saw + + + align:start position:0% +more about this uh pattern that we saw +in the two slit experiment this kind of + + align:start position:0% +in the two slit experiment this kind of + + + align:start position:0% +in the two slit experiment this kind of +row of bright + + align:start position:0% +row of bright + + + align:start position:0% +row of bright +spots and to talk about it what we're + + align:start position:0% +spots and to talk about it what we're + + + align:start position:0% +spots and to talk about it what we're +going to do is we're going to use water + + align:start position:0% +going to do is we're going to use water + + + align:start position:0% +going to do is we're going to use water +waves to try to explain + + align:start position:0% +waves to try to explain + + + align:start position:0% +waves to try to explain +it so here's a picture of the + + align:start position:0% +it so here's a picture of the + + + align:start position:0% +it so here's a picture of the +beach here's the uh here's the water + + align:start position:0% +beach here's the uh here's the water + + + align:start position:0% +beach here's the uh here's the water +right here's the + + align:start position:0% +right here's the + + + align:start position:0% +right here's the +sand and here is where I wanted to be + + align:start position:0% +sand and here is where I wanted to be + + + align:start position:0% +sand and here is where I wanted to be +all weekend okay and the way waves are + + align:start position:0% +all weekend okay and the way waves are + + + align:start position:0% +all weekend okay and the way waves are +coming in here to the beach right these + + align:start position:0% +coming in here to the beach right these + + + align:start position:0% +coming in here to the beach right these +straight blue lines are the crests of + + align:start position:0% +straight blue lines are the crests of + + + align:start position:0% +straight blue lines are the crests of +the Waves rolling into the + + align:start position:0% +the Waves rolling into the + + + align:start position:0% +the Waves rolling into the +beach and suppose I get + + align:start position:0% +beach and suppose I get + + + align:start position:0% +beach and suppose I get +ambitious and I erect a barrier right + + align:start position:0% +ambitious and I erect a barrier right + + + align:start position:0% +ambitious and I erect a barrier right +here at the shore the sand + + align:start position:0% +here at the shore the sand + + + align:start position:0% +here at the shore the sand +barrier but for whatever perverse reason + + align:start position:0% +barrier but for whatever perverse reason + + + align:start position:0% +barrier but for whatever perverse reason +I poke two holes in that sand barrier + + align:start position:0% +I poke two holes in that sand barrier + + + align:start position:0% +I poke two holes in that sand barrier +okay well what's going to happen as the + + align:start position:0% +okay well what's going to happen as the + + + align:start position:0% +okay well what's going to happen as the +w waves roll up + + align:start position:0% +w waves roll up + + + align:start position:0% +w waves roll up +well what's going to happen is that a + + align:start position:0% +well what's going to happen is that a + + + align:start position:0% +well what's going to happen is that a +little bit of the wave here this is kind + + align:start position:0% +little bit of the wave here this is kind + + + align:start position:0% +little bit of the wave here this is kind +of like a pinhole a little bit of this + + align:start position:0% +of like a pinhole a little bit of this + + + align:start position:0% +of like a pinhole a little bit of this +wave is going to leak through when it + + align:start position:0% +wave is going to leak through when it + + + align:start position:0% +wave is going to leak through when it +leaks through it's going to spread out + + align:start position:0% +leaks through it's going to spread out + + + align:start position:0% +leaks through it's going to spread out +equally in all + + align:start position:0% +equally in all + + + align:start position:0% +equally in all +directions and so the wavefront is going + + align:start position:0% +directions and so the wavefront is going + + + align:start position:0% +directions and so the wavefront is going +to look like this semicircle here right + + align:start position:0% +to look like this semicircle here right + + + align:start position:0% +to look like this semicircle here right +that's the wave Crest it's going to look + + align:start position:0% +that's the wave Crest it's going to look + + + align:start position:0% +that's the wave Crest it's going to look +like a semicircle and that's going to + + align:start position:0% +like a semicircle and that's going to + + + align:start position:0% +like a semicircle and that's going to +propagate + + align:start position:0% +propagate + + + align:start position:0% +propagate +out and when it propagates out to a + + align:start position:0% +out and when it propagates out to a + + + align:start position:0% +out and when it propagates out to a +distance of two Lambda well then another + + align:start position:0% +distance of two Lambda well then another + + + align:start position:0% +distance of two Lambda well then another +wave has snuck in here through this hole + + align:start position:0% +wave has snuck in here through this hole + + + align:start position:0% +wave has snuck in here through this hole +and it propagates out and again the + + align:start position:0% +and it propagates out and again the + + + align:start position:0% +and it propagates out and again the +distance between these two semicircles + + align:start position:0% +distance between these two semicircles + + + align:start position:0% +distance between these two semicircles +is a Lambda is the wavelength because + + align:start position:0% +is a Lambda is the wavelength because + + + align:start position:0% +is a Lambda is the wavelength because +these are the Maxima of the two + + align:start position:0% +these are the Maxima of the two + + + align:start position:0% +these are the Maxima of the two +waves and as time goes on that + + align:start position:0% +waves and as time goes on that + + + align:start position:0% +waves and as time goes on that +propagates further and another wave + + align:start position:0% +propagates further and another wave + + + align:start position:0% +propagates further and another wave +sneaks through that hole and another + + align:start position:0% +sneaks through that hole and another + + + align:start position:0% +sneaks through that hole and another +wave sneaks through and the whole thing + + align:start position:0% +wave sneaks through and the whole thing + + + align:start position:0% +wave sneaks through and the whole thing +propagates all right and meanwhile while + + align:start position:0% +propagates all right and meanwhile while + + + align:start position:0% +propagates all right and meanwhile while +that is happening there's also a part of + + align:start position:0% +that is happening there's also a part of + + + align:start position:0% +that is happening there's also a part of +the wave sneaking through this hole and + + align:start position:0% +the wave sneaking through this hole and + + + align:start position:0% +the wave sneaking through this hole and +it emanates out in all directions and + + align:start position:0% +it emanates out in all directions and + + + align:start position:0% +it emanates out in all directions and +propagates out right in all + + align:start position:0% +propagates out right in all + + + align:start position:0% +propagates out right in all +directions and uh again all right and + + align:start position:0% +directions and uh again all right and + + + align:start position:0% +directions and uh again all right and +propagates out in all + + align:start position:0% +propagates out in all + + + align:start position:0% +propagates out in all +directions and let me for the purpose of + + align:start position:0% +directions and let me for the purpose of + + + align:start position:0% +directions and let me for the purpose of +uh talking about this let me call this + + align:start position:0% +uh talking about this let me call this + + + align:start position:0% +uh talking about this let me call this +slit slit one + + align:start position:0% +slit slit one + + + align:start position:0% +slit slit one +so all the green + + align:start position:0% +so all the green + + + align:start position:0% +so all the green +waves are the waves that came through + + align:start position:0% +waves are the waves that came through + + + align:start position:0% +waves are the waves that came through +slit one and I'm going to call this slit + + align:start position:0% +slit one and I'm going to call this slit + + + align:start position:0% +slit one and I'm going to call this slit +two and all the blue waves are the waves + + align:start position:0% +two and all the blue waves are the waves + + + align:start position:0% +two and all the blue waves are the waves +that came out slit two and + + align:start position:0% +that came out slit two and + + + align:start position:0% +that came out slit two and +again the uh distance between any of + + align:start position:0% +again the uh distance between any of + + + align:start position:0% +again the uh distance between any of +these two crests is the wavelength and + + align:start position:0% +these two crests is the wavelength and + + + align:start position:0% +these two crests is the wavelength and +the wavelength is the same for the waves + + align:start position:0% +the wavelength is the same for the waves + + + align:start position:0% +the wavelength is the same for the waves +coming from slit one and slit + + align:start position:0% +coming from slit one and slit + + + align:start position:0% +coming from slit one and slit +two now what I want you to do is I want + + align:start position:0% +two now what I want you to do is I want + + + align:start position:0% +two now what I want you to do is I want +you to look at this point right here see + + align:start position:0% +you to look at this point right here see + + + align:start position:0% +you to look at this point right here see +that point + + align:start position:0% +that point + + + align:start position:0% +that point +Point well right at that point what we + + align:start position:0% +Point well right at that point what we + + + align:start position:0% +Point well right at that point what we +have is we've got the wave Crest the + + align:start position:0% +have is we've got the wave Crest the + + + align:start position:0% +have is we've got the wave Crest the +wave maximum from slit two at the same + + align:start position:0% +wave maximum from slit two at the same + + + align:start position:0% +wave maximum from slit two at the same +point in space as the wave Maxima from + + align:start position:0% +point in space as the wave Maxima from + + + align:start position:0% +point in space as the wave Maxima from +slit one so if we've got two Maxima at + + align:start position:0% +slit one so if we've got two Maxima at + + + align:start position:0% +slit one so if we've got two Maxima at +the same point in space hey we got + + align:start position:0% +the same point in space hey we got + + + align:start position:0% +the same point in space hey we got +constructive interference right there + + align:start position:0% +constructive interference right there + + + align:start position:0% +constructive interference right there +right because those amplitudes are going + + align:start position:0% +right because those amplitudes are going + + + align:start position:0% +right because those amplitudes are going +to + + align:start position:0% +to + + + align:start position:0% +to +add look at this point well again we got + + align:start position:0% +add look at this point well again we got + + + align:start position:0% +add look at this point well again we got +the wave Maxima from this Blue Wave + + align:start position:0% +the wave Maxima from this Blue Wave + + + align:start position:0% +the wave Maxima from this Blue Wave +coming through slit 2 at the same point + + align:start position:0% +coming through slit 2 at the same point + + + align:start position:0% +coming through slit 2 at the same point +in space as the wave Maxima from the + + align:start position:0% +in space as the wave Maxima from the + + + align:start position:0% +in space as the wave Maxima from the +wave coming from slit one again this is + + align:start position:0% +wave coming from slit one again this is + + + align:start position:0% +wave coming from slit one again this is +a point of constructive + + align:start position:0% +a point of constructive + + + align:start position:0% +a point of constructive +interference and we can keep going again + + align:start position:0% +interference and we can keep going again + + + align:start position:0% +interference and we can keep going again +we have two Maxima right here a point of + + align:start position:0% +we have two Maxima right here a point of + + + align:start position:0% +we have two Maxima right here a point of +constructive interference and you know + + align:start position:0% +constructive interference and you know + + + align:start position:0% +constructive interference and you know +what everywhere along this line we're + + align:start position:0% +what everywhere along this line we're + + + align:start position:0% +what everywhere along this line we're +going to have constructive interference + + align:start position:0% +going to have constructive interference + + + align:start position:0% +going to have constructive interference +we're going to have a resultant wave a + + align:start position:0% +we're going to have a resultant wave a + + + align:start position:0% +we're going to have a resultant wave a +water wave that's going to be twice as + + align:start position:0% +water wave that's going to be twice as + + + align:start position:0% +water wave that's going to be twice as +high right + + align:start position:0% +high right + + + align:start position:0% +high right +as each of the individual + + align:start position:0% +as each of the individual + + + align:start position:0% +as each of the individual +waves look at this okay and what I want + + align:start position:0% +waves look at this okay and what I want + + + align:start position:0% +waves look at this okay and what I want +you to notice here for this point all + + align:start position:0% +you to notice here for this point all + + + align:start position:0% +you to notice here for this point all +right for this point the wave that is + + align:start position:0% +right for this point the wave that is + + + align:start position:0% +right for this point the wave that is +constructively + + align:start position:0% +constructively + + + align:start position:0% +constructively +interfering that has traveled from the + + align:start position:0% +interfering that has traveled from the + + + align:start position:0% +interfering that has traveled from the +slit a distance R2 because this is slit + + align:start position:0% +slit a distance R2 because this is slit + + + align:start position:0% +slit a distance R2 because this is slit +two + + align:start position:0% +two + + + align:start position:0% +two +but the distance from here to here is + + align:start position:0% +but the distance from here to here is + + + align:start position:0% +but the distance from here to here is +four Lambda right it's one Lambda 2 + + align:start position:0% +four Lambda right it's one Lambda 2 + + + align:start position:0% +four Lambda right it's one Lambda 2 +Lambda 3 Lambda 4 Lambda right the + + align:start position:0% +Lambda 3 Lambda 4 Lambda right the + + + align:start position:0% +Lambda 3 Lambda 4 Lambda right the +radius R2 of this circle is four + + align:start position:0% +radius R2 of this circle is four + + + align:start position:0% +radius R2 of this circle is four +Lambda and it is interfering with this + + align:start position:0% +Lambda and it is interfering with this + + + align:start position:0% +Lambda and it is interfering with this +wave + + align:start position:0% +wave + + + align:start position:0% +wave +Crest and the distance that that wave + + align:start position:0% +Crest and the distance that that wave + + + align:start position:0% +Crest and the distance that that wave +traveled from slit one I'm going to call + + align:start position:0% +traveled from slit one I'm going to call + + + align:start position:0% +traveled from slit one I'm going to call +R1 and that's equal to three Lambda 1 2 + + align:start position:0% +R1 and that's equal to three Lambda 1 2 + + + align:start position:0% +R1 and that's equal to three Lambda 1 2 + + align:start position:0% + + + align:start position:0% +okay so the this interference here is + + align:start position:0% +okay so the this interference here is + + + align:start position:0% +okay so the this interference here is +between this wave that's traveled out a + + align:start position:0% +between this wave that's traveled out a + + + align:start position:0% +between this wave that's traveled out a +distance for Lambda and this wave that's + + align:start position:0% +distance for Lambda and this wave that's + + + align:start position:0% +distance for Lambda and this wave that's +traveled out a distance three Lambda and + + align:start position:0% +traveled out a distance three Lambda and + + + align:start position:0% +traveled out a distance three Lambda and +the difference in the distance traveled + + align:start position:0% +the difference in the distance traveled + + + align:start position:0% +the difference in the distance traveled +by those two waves that are + + align:start position:0% +by those two waves that are + + + align:start position:0% +by those two waves that are +constructively interfering is 4 Lambda + + align:start position:0% +constructively interfering is 4 Lambda + + + align:start position:0% +constructively interfering is 4 Lambda +minus 3 Lambda = 1 + + align:start position:0% +minus 3 Lambda = 1 + + + align:start position:0% +minus 3 Lambda = 1 +Lambda okay is there a question over + + align:start position:0% +Lambda okay is there a question over + + + align:start position:0% +Lambda okay is there a question over +here yes + + align:start position:0% + + + + align:start position:0% + +okay H I think I'm coming to that that's + + align:start position:0% +okay H I think I'm coming to that that's + + + align:start position:0% +okay H I think I'm coming to that that's +was a snapshot of the next slide okay + + align:start position:0% +was a snapshot of the next slide okay + + + align:start position:0% +was a snapshot of the next slide okay +sorry all right yes how do you know the + + align:start position:0% +sorry all right yes how do you know the + + + align:start position:0% +sorry all right yes how do you know the +are + + align:start position:0% +are + + + align:start position:0% +are +one because um we are treating these as + + align:start position:0% +one because um we are treating these as + + + align:start position:0% +one because um we are treating these as +regular waves okay ordered waves real + + align:start position:0% +regular waves okay ordered waves real + + + align:start position:0% +regular waves okay ordered waves real +waves on an ocean aren't like that okay + + align:start position:0% +waves on an ocean aren't like that okay + + + align:start position:0% +waves on an ocean aren't like that okay +and then you won't see this defraction + + align:start position:0% +and then you won't see this defraction + + + align:start position:0% +and then you won't see this defraction +pattern that uh I'm ere ing here but if + + align:start position:0% +pattern that uh I'm ere ing here but if + + + align:start position:0% +pattern that uh I'm ere ing here but if +you had pretty regular waves coming in + + align:start position:0% +you had pretty regular waves coming in + + + align:start position:0% +you had pretty regular waves coming in +in principle you could see it and I'm + + align:start position:0% +in principle you could see it and I'm + + + align:start position:0% +in principle you could see it and I'm +going to show you a a a um a uh in a in + + align:start position:0% +going to show you a a a um a uh in a in + + + align:start position:0% +going to show you a a a um a uh in a in +a tank some water waves that do just + + align:start position:0% +a tank some water waves that do just + + + align:start position:0% +a tank some water waves that do just +this okay yeah + + align:start position:0% + + + + align:start position:0% + +okay all right now I want you to look at + + align:start position:0% +okay all right now I want you to look at + + + align:start position:0% +okay all right now I want you to look at +this point right here all right right + + align:start position:0% +this point right here all right right + + + align:start position:0% +this point right here all right right +here we have a point of constructive + + align:start position:0% +here we have a point of constructive + + + align:start position:0% +here we have a point of constructive +interference because we have two Maxima + + align:start position:0% +interference because we have two Maxima + + + align:start position:0% +interference because we have two Maxima +at the same point in space + + align:start position:0% +at the same point in space + + + align:start position:0% +at the same point in space +and at this point we've got constructive + + align:start position:0% +and at this point we've got constructive + + + align:start position:0% +and at this point we've got constructive +interference so everywhere along this + + align:start position:0% +interference so everywhere along this + + + align:start position:0% +interference so everywhere along this +line here we're going to have + + align:start position:0% +line here we're going to have + + + align:start position:0% +line here we're going to have +constructive + + align:start position:0% +constructive + + + align:start position:0% +constructive +interference and now I want you to look + + align:start position:0% +interference and now I want you to look + + + align:start position:0% +interference and now I want you to look +at the difference in the distance of the + + align:start position:0% +at the difference in the distance of the + + + align:start position:0% +at the difference in the distance of the +waves that yield this constructive + + align:start position:0% +waves that yield this constructive + + + align:start position:0% +waves that yield this constructive +interference along this line + + align:start position:0% +interference along this line + + + align:start position:0% +interference along this line +okay I want you to look at this Green + + align:start position:0% +okay I want you to look at this Green + + + align:start position:0% +okay I want you to look at this Green +Wave this Green Wave + + align:start position:0% +Wave this Green Wave + + + align:start position:0% +Wave this Green Wave +that's constructively interfering with + + align:start position:0% +that's constructively interfering with + + + align:start position:0% +that's constructively interfering with +this Blue Wave this Green Wave has + + align:start position:0% +this Blue Wave this Green Wave has + + + align:start position:0% +this Blue Wave this Green Wave has +traveled out a distance R1 or 2 + + align:start position:0% +traveled out a distance R1 or 2 + + + align:start position:0% +traveled out a distance R1 or 2 +Lambda and it is interfering with this + + align:start position:0% +Lambda and it is interfering with this + + + align:start position:0% +Lambda and it is interfering with this +uh Blue Wave here that has traveled out + + align:start position:0% +uh Blue Wave here that has traveled out + + + align:start position:0% +uh Blue Wave here that has traveled out +a distance for Lambda R2 equal 4 + + align:start position:0% +a distance for Lambda R2 equal 4 + + + align:start position:0% +a distance for Lambda R2 equal 4 +Lambda so the difference in the distance + + align:start position:0% +Lambda so the difference in the distance + + + align:start position:0% +Lambda so the difference in the distance +travel for all of these points that lead + + align:start position:0% +travel for all of these points that lead + + + align:start position:0% +travel for all of these points that lead +to constructive interference the + + align:start position:0% +to constructive interference the + + + align:start position:0% +to constructive interference the +difference in the distance traveled here + + align:start position:0% +difference in the distance traveled here + + + align:start position:0% +difference in the distance traveled here +is is R2 - + + align:start position:0% +is is R2 - + + + align:start position:0% +is is R2 - +R1 or 4 Lambda minus 2 Lambda equal 2 + + align:start position:0% +R1 or 4 Lambda minus 2 Lambda equal 2 + + + align:start position:0% +R1 or 4 Lambda minus 2 Lambda equal 2 +Lambda does that agree with the snapshot + + align:start position:0% +Lambda does that agree with the snapshot + + + align:start position:0% +Lambda does that agree with the snapshot +in your + + align:start position:0% +in your + + + align:start position:0% +in your +picture yes okay I just didn't show you + + align:start position:0% +picture yes okay I just didn't show you + + + align:start position:0% +picture yes okay I just didn't show you +the U uh other one + + align:start position:0% +the U uh other one + + + align:start position:0% +the U uh other one +okay all + + align:start position:0% +okay all + + + align:start position:0% +okay all +right now I want you to look here here's + + align:start position:0% +right now I want you to look here here's + + + align:start position:0% +right now I want you to look here here's +a point of constructive + + align:start position:0% +a point of constructive + + + align:start position:0% +a point of constructive +interference here's another point of + + align:start position:0% +interference here's another point of + + + align:start position:0% +interference here's another point of +constructive + + align:start position:0% +constructive + + + align:start position:0% +constructive +interference everywhere along this line + + align:start position:0% +interference everywhere along this line + + + align:start position:0% +interference everywhere along this line +we're going to have constructive + + align:start position:0% +we're going to have constructive + + + align:start position:0% +we're going to have constructive +interference and if we check out what + + align:start position:0% +interference and if we check out what + + + align:start position:0% +interference and if we check out what +the difference in the distance traveled + + align:start position:0% +the difference in the distance traveled + + + align:start position:0% +the difference in the distance traveled +is between the waves that are + + align:start position:0% +is between the waves that are + + + align:start position:0% +is between the waves that are +constructively interfering there you're + + align:start position:0% +constructively interfering there you're + + + align:start position:0% +constructively interfering there you're +going to see that R2 minus R1 is equal + + align:start position:0% +going to see that R2 minus R1 is equal + + + align:start position:0% +going to see that R2 minus R1 is equal +to zero all + + align:start position:0% + + + + align:start position:0% + +right all right now so what you would + + align:start position:0% +right all right now so what you would + + + align:start position:0% +right all right now so what you would +predict is we'd have along this angle + + align:start position:0% +predict is we'd have along this angle + + + align:start position:0% +predict is we'd have along this angle +some very bright spots along this angle + + align:start position:0% +some very bright spots along this angle + + + align:start position:0% +some very bright spots along this angle +some very bright spots and along this + + align:start position:0% +some very bright spots and along this + + + align:start position:0% +some very bright spots and along this +angle some very bright spots and you + + align:start position:0% +angle some very bright spots and you + + + align:start position:0% +angle some very bright spots and you +also can see that there is going to be + + align:start position:0% +also can see that there is going to be + + + align:start position:0% +also can see that there is going to be +symmetric about the center so you would + + align:start position:0% +symmetric about the center so you would + + + align:start position:0% +symmetric about the center so you would +have bright spots here bright spots + + align:start position:0% +have bright spots here bright spots + + + align:start position:0% +have bright spots here bright spots +there well let's look at this uh in real + + align:start position:0% +there well let's look at this uh in real + + + align:start position:0% +there well let's look at this uh in real +life in a water tank where we have waves + + align:start position:0% +life in a water tank where we have waves + + + align:start position:0% +life in a water tank where we have waves +uh there you go where we have waves + + align:start position:0% +uh there you go where we have waves + + + align:start position:0% +uh there you go where we have waves +plane waves coming in to a barrier and + + align:start position:0% +plane waves coming in to a barrier and + + + align:start position:0% +plane waves coming in to a barrier and +then we have two little slits like right + + align:start position:0% +then we have two little slits like right + + + align:start position:0% +then we have two little slits like right +there and right there and what you can + + align:start position:0% +there and right there and what you can + + + align:start position:0% +there and right there and what you can +see is that these bright semi circles + + align:start position:0% +see is that these bright semi circles + + + align:start position:0% +see is that these bright semi circles +well well those are in fact the crests + + align:start position:0% +well well those are in fact the crests + + + align:start position:0% +well well those are in fact the crests +of the + + align:start position:0% +of the + + + align:start position:0% +of the +waves but what I want you to see is + + align:start position:0% +waves but what I want you to see is + + + align:start position:0% +waves but what I want you to see is +right here whoops what happened oh okay + + align:start position:0% + + + + align:start position:0% + +okay all + + align:start position:0% +okay all + + + align:start position:0% +okay all +right there you go okay what I want you + + align:start position:0% +right there you go okay what I want you + + + align:start position:0% +right there you go okay what I want you +to see is right here these are the + + align:start position:0% +to see is right here these are the + + + align:start position:0% +to see is right here these are the +bright this bright row here's a bright + + align:start position:0% +bright this bright row here's a bright + + + align:start position:0% +bright this bright row here's a bright +row here's a bright row and in between + + align:start position:0% +row here's a bright row and in between + + + align:start position:0% +row here's a bright row and in between +there's kind of just a muddy a diffuse + + align:start position:0% +there's kind of just a muddy a diffuse + + + align:start position:0% +there's kind of just a muddy a diffuse +pattern well this diffuse pattern is + + align:start position:0% +pattern well this diffuse pattern is + + + align:start position:0% +pattern well this diffuse pattern is +nothing this is a bright row + + align:start position:0% +nothing this is a bright row + + + align:start position:0% +nothing this is a bright row +okay okay that's all + + align:start position:0% +okay okay that's all + + + align:start position:0% +okay okay that's all +right all right but you get the idea + + align:start position:0% +right all right but you get the idea + + + align:start position:0% +right all right but you get the idea +right you're going to have an angle + + align:start position:0% +right you're going to have an angle + + + align:start position:0% +right you're going to have an angle +which there's going to be constructive + + align:start position:0% +which there's going to be constructive + + + align:start position:0% +which there's going to be constructive +interference several angles of which + + align:start position:0% +interference several angles of which + + + align:start position:0% +interference several angles of which +they're going to be constructive + + align:start position:0% +they're going to be constructive + + + align:start position:0% +they're going to be constructive +interference and in between those places + + align:start position:0% +interference and in between those places + + + align:start position:0% +interference and in between those places +where there's constructive interference + + align:start position:0% +where there's constructive interference + + + align:start position:0% +where there's constructive interference +there's destructive interference and + + align:start position:0% +there's destructive interference and + + + align:start position:0% +there's destructive interference and +you're not going to have any + + align:start position:0% +you're not going to have any + + + align:start position:0% +you're not going to have any +light + + align:start position:0% +light + + + align:start position:0% +light +okay so how does + + align:start position:0% +okay so how does + + + align:start position:0% +okay so how does +that how does that relate to what we saw + + align:start position:0% +that how does that relate to what we saw + + + align:start position:0% +that how does that relate to what we saw +in the two slit defraction + + align:start position:0% +in the two slit defraction + + + align:start position:0% +in the two slit defraction +experiment well + + align:start position:0% + + + + align:start position:0% + +along this + + align:start position:0% +along this + + + align:start position:0% +along this +line we have waves that have + + align:start position:0% +line we have waves that have + + + align:start position:0% +line we have waves that have +constructively + + align:start position:0% +constructively + + + align:start position:0% +constructively +interfered and they constructively + + align:start position:0% +interfered and they constructively + + + align:start position:0% +interfered and they constructively +interfere so that on the screen right + + align:start position:0% +interfere so that on the screen right + + + align:start position:0% +interfere so that on the screen right +there you have a bright + + align:start position:0% +there you have a bright + + + align:start position:0% +there you have a bright +spot and along this line the difference + + align:start position:0% +spot and along this line the difference + + + align:start position:0% +spot and along this line the difference +in the distance traveled by the waves + + align:start position:0% +in the distance traveled by the waves + + + align:start position:0% +in the distance traveled by the waves +that it constructively interfere is one + + align:start position:0% + + + + align:start position:0% + +Lambda and then we've got another row or + + align:start position:0% +Lambda and then we've got another row or + + + align:start position:0% +Lambda and then we've got another row or +another line + + align:start position:0% +another line + + + align:start position:0% +another line +points of constructive interference + + align:start position:0% +points of constructive interference + + + align:start position:0% +points of constructive interference +that's going to image as a bright + + align:start position:0% +that's going to image as a bright + + + align:start position:0% +that's going to image as a bright +spot and if you analyze that the + + align:start position:0% +spot and if you analyze that the + + + align:start position:0% +spot and if you analyze that the +difference in the distance traveled by + + align:start position:0% +difference in the distance traveled by + + + align:start position:0% +difference in the distance traveled by +these two waves is 2 + + align:start position:0% +these two waves is 2 + + + align:start position:0% +these two waves is 2 +Lambda and then we're going to have + + align:start position:0% +Lambda and then we're going to have + + + align:start position:0% +Lambda and then we're going to have +another bright spot here right for all + + align:start position:0% +another bright spot here right for all + + + align:start position:0% +another bright spot here right for all +the constructive interference along this + + align:start position:0% +the constructive interference along this + + + align:start position:0% +the constructive interference along this +line the difference in the distance + + align:start position:0% +line the difference in the distance + + + align:start position:0% +line the difference in the distance +traveled is zero and of course I said + + align:start position:0% +traveled is zero and of course I said + + + align:start position:0% +traveled is zero and of course I said +before this was symmetric around the + + align:start position:0% +before this was symmetric around the + + + align:start position:0% +before this was symmetric around the +center and so this is what gives rise to + + align:start position:0% +center and so this is what gives rise to + + + align:start position:0% +center and so this is what gives rise to +the different bright spots on the screen + + align:start position:0% +the different bright spots on the screen + + + align:start position:0% +the different bright spots on the screen +when we did the two slit experiment + + align:start position:0% +when we did the two slit experiment + + + align:start position:0% +when we did the two slit experiment +bright + + align:start position:0% +bright + + + align:start position:0% +bright +spot dark spot bright spot dark + + align:start position:0% +spot dark spot bright spot dark + + + align:start position:0% +spot dark spot bright spot dark +spot okay the bright spots are + + align:start position:0% +spot okay the bright spots are + + + align:start position:0% +spot okay the bright spots are +constructive + + align:start position:0% +constructive + + + align:start position:0% +constructive +interference the dark spots here are + + align:start position:0% +interference the dark spots here are + + + align:start position:0% +interference the dark spots here are +destructive + + align:start position:0% +destructive + + + align:start position:0% +destructive +interference + + align:start position:0% +interference + + + align:start position:0% +interference +okay now let me just tell you you that + + align:start position:0% +okay now let me just tell you you that + + + align:start position:0% +okay now let me just tell you you that +the general condition for having these + + align:start position:0% +the general condition for having these + + + align:start position:0% +the general condition for having these +bright + + align:start position:0% +bright + + + align:start position:0% +bright +spots the general condition that has to + + align:start position:0% +spots the general condition that has to + + + align:start position:0% +spots the general condition that has to +obtain is that the difference in the + + align:start position:0% +obtain is that the difference in the + + + align:start position:0% +obtain is that the difference in the +distance traveled has to be equal to n + + align:start position:0% +distance traveled has to be equal to n + + + align:start position:0% +distance traveled has to be equal to n +in integer times Lambda right this + + align:start position:0% +in integer times Lambda right this + + + align:start position:0% +in integer times Lambda right this +Bright Spot the Difference in the + + align:start position:0% +Bright Spot the Difference in the + + + align:start position:0% +Bright Spot the Difference in the +distance traveled then is zero we call + + align:start position:0% +distance traveled then is zero we call + + + align:start position:0% +distance traveled then is zero we call +that the zero order spot this Bright + + align:start position:0% +that the zero order spot this Bright + + + align:start position:0% +that the zero order spot this Bright +Spot the Difference in the distance + + align:start position:0% +Spot the Difference in the distance + + + align:start position:0% +Spot the Difference in the distance +traveled is land lamb or n * Lambda + + align:start position:0% +traveled is land lamb or n * Lambda + + + align:start position:0% +traveled is land lamb or n * Lambda +where n is one first order interference + + align:start position:0% +where n is one first order interference + + + align:start position:0% +where n is one first order interference +feature here the difference in the + + align:start position:0% +feature here the difference in the + + + align:start position:0% +feature here the difference in the +distance traveled is 2 Lambda n * 2 + + align:start position:0% +distance traveled is 2 Lambda n * 2 + + + align:start position:0% +distance traveled is 2 Lambda n * 2 +called the second order interference + + align:start position:0% +called the second order interference + + + align:start position:0% +called the second order interference +feature and the condition for that is + + align:start position:0% +feature and the condition for that is + + + align:start position:0% +feature and the condition for that is +this R2 - R1 equal n * + + align:start position:0% +this R2 - R1 equal n * + + + align:start position:0% +this R2 - R1 equal n * +Lambda there is also a condition for + + align:start position:0% +Lambda there is also a condition for + + + align:start position:0% +Lambda there is also a condition for +destructive + + align:start position:0% +destructive + + + align:start position:0% +destructive +interference which I ask you to think + + align:start position:0% +interference which I ask you to think + + + align:start position:0% +interference which I ask you to think +about and we'll talk just briefly about + + align:start position:0% +about and we'll talk just briefly about + + + align:start position:0% +about and we'll talk just briefly about +its origin next time all right see you + + align:start position:0% +its origin next time all right see you + + + align:start position:0% +its origin next time all right see you +on Wednesday \ No newline at end of file diff --git a/_SxMjq1_RrI.txt b/_SxMjq1_RrI.txt new file mode 100644 index 0000000000000000000000000000000000000000..83297bda024d6af8a8ca0e488de9c660d8014d83 --- /dev/null +++ b/_SxMjq1_RrI.txt @@ -0,0 +1,1906 @@ +The following +content is provided + +under a Creative +Commons license. + +Your support will help MIT +OpenCourseWare continue + +to offer high quality +educational resources for free. + +To make a donation or +view additional materials + +from hundreds of MIT courses, +visit MIT OpenCourseWare + +at ocw.mit.edu. + +PROFESSOR: OK, so let's move +into are our topic for the day. + +So we've got a couple of things. + +We're going to talk a little +bit about In a Silent Way. + +And then I want to +have us have a chance + +to present what +you have created. + +And we'll see how this goes. + +So this is pretty much, at least +in the second part, unknown. + +We don't know what's +going to happen. + +So it should be interesting. + +But in terms of In +a Silent Way, did + +everybody get to listen to that? + +And what do you make of +that composition, called + +In a Silent Way by Miles Davis? + +What do you make of that? + +What did you hear happening? + +AUDIENCE: It seemed modal, so it +didn't have any definite chord + +changes, which I think +gave it sort of like a, + +like, spacey +ambiguous feel to it. + +PROFESSOR: OK. + +Good. + +Modal, spacey, ambiguous. + +Anybody else? + +AUDIENCE: A lot of the melody +and things were also ambiguous. + +There were a few clear +themes that would repeat, + +but there was a +lot of just sounds. + +That was cool. + +PROFESSOR: Sounds, OK. + +AUDIENCE: The instrumentation +was just very different + +from the other Miles Davis +pieces we'd listened to, + +and the style and +everything, like it being + +so like a slow, laid-back, +almost free-flowing piece, + +with a more I guess like +electronic feel to it. + +But that was interesting. + +PROFESSOR: Right. + +And because, what were +some of the accompanying + +instruments in this? + +AUDIENCE: It sounded maybe +like a synth, I want to say. + +Was that a synth? + +PROFESSOR: Fender Rhodes. + +Actually, two +Fender Rhodes piano, + +which is sort of old school. + +But you see these around a lot. + +In fact, we have +one at MIT, which + +the current pianist +with the FJE likes + +to call it out and play it. + +So that's great. + +And somebody playing the +organ, as well as that. + +What else? + +What else did you +hear, instruments? + +AUDIENCE: How prominent +the instruments + +were to one another was more +uniform than the recordings + +we've listened to. + +PROFESSOR: Meaning? + +AUDIENCE: Like, it's not like +that obviously the trumpet + +had the lead the whole time. + +PROFESSOR: Right. + +So a lot more diversity +of who is sort of + +in the lead and +that kind of thing. + +Was it only that sort of +ambiguous free floating sound? + +Was it only that, are +did it do something else? + +AUDIENCE: Well, after a +few minutes [INAUDIBLE] + +PROFESSOR: OK, a regular beat. + +And what was the +rhythmic feel there? + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: But I mean, +was it jazz, was it-- + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: Percussive. + +OK. + +Anybody else have +a term that could + +characterize what it went into? + +We all heard the piece, right? + +And it was a fairly +long piece, right, + +like about 20 minute piece? + +OK. + +I was sure you would catch this. + +It goes into essentially +a rock kind of a feel. + +It's a more subtle +rock feel than what + +you would have heard from +a rock band in that period. + +But nonetheless, that's +what it's going to. + +This became sort of +the signature piece + +that moved jazz into what was +called jazz rock or fusion. + +In 1969 is when this came out. + +And in fact, this middle +part is the longest part + +of the whole piece. + +It's where most of +the soloing happens. + +And then it returns to this sort +of quieter, more lyrical thing + +at the end. + +And I put these +names of the board, + +because it turns out +that this is actually + +a piece that was put +together in the studio. + +It's a studio realization, +you could say. + +And the first part is +called In a Silent Way. + +That's composed by +Joe Zawinul, who + +was one of the three +keyboard players. + +That shows up at the +beginning and at the end. + +And in the middle is a piece +that both Zawinul and Miles + +Davis co-composed, called +It's About That Time, which + +is the more funky, +rock type of piece. + +And so they decided to +essentially blend these pieces. + +And the further +thing about this is + +this was an early +attempt by people + +in the studio, one guy in +particular, Teo Macero, who + +worked with Miles Davis a +lot, to essentially sort + +of you could say cut +and paste, because they + +used to have to splice tape +to make cuts and paste them + +back together. + +It's before digital editing. + +And so there's +some of that that's + +going on in the middle section. + +And in fact, the last +section is exactly what + +was played for the +first four minutes. + +It's just a replica. + +It's a replication. + +It's the same exact music +just pasted in at the end. + +So it sort of calls +into a new perspective + +what is improvisation and what +is jazz composition, really. + +And you're going +to have a chance + +to talk with Neil +Leonard when he comes + +in about another month about +exactly that, electronic usage, + +computer usage, and +improvisation stuff. + +But this is sort of +an early attempt. + +The other thing that I wanted +us to listen to this for + +is that this basically is a +jazz version of the format + +that we're going to hear on +Sunday at the Indian concert. + +Because how many people have +had the Music of India course? + +Anybody have that course? + +You've had that. + +Anybody else? + +And so you know that the way +that the music in the Raga + +tradition works is there's a +very slow presentation, as it's + +called, of the raga, +the main melody. + +And then after that is +allowed to be stated + +in a very lyrical, +free floating way, + +then you get this rhythmic +sense with a particular cycle + +or a tala that comes in. + +And so it's hard to believe that +Miles Davis was not influenced + +by John Coltrane, +who had previously + +been part of Miles' band. + +But Coltrane, as +many of you know, + +had explored the music of India. + +And so it's sort of +like a cross influence + +coming back from what +somebody had originally + +been a player in Miles' band +coming back to inform him. + +And this piece really has a very +Indian at least pattern to it, + +if not Indian music. + +It's not a raga, but it is +its own particular mode, + +as people have said. + +Anybody know what mode +it was, or did you + +try to figure that out? + +AUDIENCE: Was it, +could it be in Dorian? + +Because it began with a flat +[INAUDIBLE] 7th, I think. + +PROFESSOR: OK. + +Anybody have a +different take on it? + +AUDIENCE: I figured out +which notes were in the mode, + +but I don't know if I +could remember them. + +I was playing along +to it, but I didn't + +think about what +the actual mode was. + +PROFESSOR: OK, but you +tried to play along with it. + +That's good. + +AUDIENCE: Yeah. + +I feel like I figured out +which notes that actually fit. + +AUDIENCE: Anybody remember what +was going on at the same time + +that the melody +was being played? + +So obviously I'm +going to suggest + +you go listen to it again, so +we can hear more deeply inside + +of what's going on. + +Let me just come over to +the piano for a second. + +I made a brief transcription +of this melody. + +And what's going on +is-- if I can just + +get over there-- the +first thing that we + +have with this is a drone. + +A drone is just a long +note underneath the melody. + +And we've done that with +some of our exercises, + +right, where we've just +had a basic tonal center. + +I didn't call it that, +but that's what it is. + +Same thing in Indian music. + +There's a drone established +by one of the instruments. + +And then the melody +works off that. + +So in this case, it's +an E. [PIANO PLAYING] + +So you're always hearing this +E, and then it's actually, + +this is the melody. + +[PIANO PLAYING] It +starts on the third. + +If you were in E and +you had E major chord, + +it's actually the third of the +E major chord. [PIANO PLAYING] + +But you never get that chord. + +You just get this. + +[PIANO PLAYING] + +PROFESSOR: And that's +a big interval. + +That's a minor seventh jump. + +And here's where you get the +tip off of what the mode is. + +[PIANO PLAYING] + +PROFESSOR: And what that +is is E to D natural, which + +means that it's E essentially +mixolydian, because if you had + +come on that same phrase +and gone [PIANO PLAYING] + +it's totally different. +[PIANO PLAYING] + +And it winds up on +the fifth, which + +is the B, which is +again an open sound. + +So except for occasionally +getting a major third of what + +might have been the +chord, it's really + +ambiguous, which a +number of you said. + +Yeah, Jamie, you had a point. + +AUDIENCE: Yeah, it's +funny because the piece + +that I wrote, which I wrote +after I listened to the song, + +was in E mixolydian. + +So obviously that +transferred over. + +PROFESSOR: Deeply +influenced by this piece. + +And that's great. + +AUDIENCE: So I +knew as soon as you + +played that, that +was E mixolydian. + +PROFESSOR: That's OK. + +That's how we learn. + +And that's a great homage +to this particular piece. + +So what we've got here, in other +words, is a pretty simple mode. + +It's just one. + +And it almost sounds +like it's major, + +except for that little trick +note that I pointed out. + +But that's a very +distinctive note. + +And so when you +listen to this again, + +pay attention to that, +because it really + +is the thing that +sets this piece off + +apart from many others. + +Now the interesting +thing about this + +is according to +people who have really + +studied this and +interviewed people + +who were on the recording +session, when Joe Zawinul, who + +wrote this tune, the one we just +talked about, when he brought + +this into the recording +session, he had chords with it. + +He had chord changes +written for it. + +And Miles Davis +saw this and said + +to the guitar player, +John McLaughlin, + +why don't you just +play the melody? + +And it sort of took +McLaughlin aback. + +It was like, well, what am I +going to do with the chords? + +And the piano player +said, what are we + +going to do with the chords? + +He said, don't play them. + +Just-- Dave Holland was +the bass player-- just + +put a E pedal underneath +all of this, play the melody + +and let that be the whole thing. + +And so according to these +people again at the session, + +they did this. + +And no one was sure how +it was going to turn out. + +And when they +heard the playback, + +they were just astonished, +because it made so much sense. + +And this is sort of the next +level after Kind of Blue. + +In fact, it was 10 years +after Kind of Blue. + +So it's sort of like +moving from that, + +building on that +direction, incorporating + +some Indian-ish +type things with it, + +and coming out +with what we have. + +So I really do recommend +you listen to this again. + +Try to hear some of these other +things that are happening. + +And when you hear the middle +section, this other tune, + +it's called It's About That +Time, pay attention to this, + +because this now shifts +the tonal center up + +a half step to F. Some +people say it's mixolydian. + +I hear it as a pentatonic sound. + +So see if you can maybe +play along with that. + +That would be a good one +to play around and just see + +what you can figure +out on the bass-line. + +And that's all it +is, is a bass-line, + +with a lot of textures. + +Remember, we've +talked about textures + +from the other instruments. + +And this is particularly so +with the three keyboards. + +So it's a great piece, and +it bears listening to again. + +OK, so the assignment +for you guys + +was to come up with a piece that +was similarly a long flowing + +melody of between +10 and 15 notes, + +and then figure out +a way to present it. + +So who would like to +present their piece? + +AUDIENCE: So the melody sort of +goes like this. [BANJO PLAYING] + +That's just sort of the thing +that we're going to play around + +on, is this. +[BANJO PLAYING] And there's + +a second part that will come in +occasionally. [BANJO PLAYING] + +Just like that, which +is that second part. + +Alright. + +So why don't you, ah-- + +[BANJO PLAYING] + +[SAXOPHONE JOINS BANJO] + +[APPLAUSE] + +PROFESSOR: Very nice. + +Play those opening +notes that you + +played when you told us +what it was made out of. + +[BANJO PLAYING] + +AUDIENCE: You mean, +just like the-- + +PROFESSOR: The +little melody notes + +that you would play it around. + +[BANJO PLAYING] + +PROFESSOR: Sarah, what +does that sound like? + +What kind of music +does that sound like? + +AUDIENCE: It does kind of +sound like Indian music. + +PROFESSOR: It sounds +like Indian music. + +Have you heard +much Indian music? + +AUDIENCE: Oh, yeah, before. + +That's what I thought of. + +PROFESSOR: So it must be +going into your consciousness. + +AUDIENCE: Yeah, at +one point I was like, + +oh, it sounds a little Indian. + +PROFESSOR: So when you +hear the concert on Sunday, + +what you're going to hear is +something very similar to that. + +That'll be the presentation +of the raga, that sort of idea + +that you just did. + +And in fact, when you got +into that rhythmic thing, + +particularly your picking +style, as well as piano, + +that would be very similar to +what the tabla, the drummer + +would be doing, to give +a percussive thing. + +So this is great. + +This is like +unconscious processing + +of where we're going. + +So brilliant. + +And very nice playing +on the saxophone. + +Very nice. + +You're bringing out +what would be called + +the characteristic feature of +the mode or if it was a rag, + +there's certain +particular things. + +And Phil Scarf when he +comes a week from-- well, + +it'll be on next +Monday-- he'll be + +talking about that very +particular, specific thing. + +So very well done. + +Good job. + +Good job. + +[APPLAUSE] + +PROFESSOR: Who would +like to go next? + +AUDIENCE: It goes from D +dorian, G mixolydian, C major. + +So piano should +be playing chords. + +And then the melody, I was +thinking flute and oboe + +could maybe improvise +on part of it, + +like when you get to the major? + +That's C major. + +Yeah. + +There's not really time to this. + +So I sort of suggested +which notes might be shorter + +and which ones might be longer. + +But take whatever time you want. + +That's why I figured +maybe it's not best time + +for lots of people +playing at once. + +AUDIENCE: [INAUDIBLE] sort of +loop around a couple times? + +AUDIENCE: Yeah, I think +once would not be enough. + +So maybe let's do +two or three times. + +And I'm going to sit this +out, because transposing + +and to keep it quiet. + +So I guess flute and piano, +whenever you're ready. + +[PIANO AND FLUTE PLAYING] + +[OBOE ENTERS] + +[APPLAUSE] + +PROFESSOR: So you were +playing the actual melody. + +And you were improvising +within the mode, or something, + +or around it. + +Very nice. + +AUDIENCE: Liked the +percussive improvisation + +at the very beginning. + +AUDIENCE: Oh, yeah, sorry. + +I should have tested +a couple of notes. + +PROFESSOR: Very, very nice. + +Very nice. + +Cool. + +AUDIENCE: I've got a +simple melody which + +I'd like again to be +played by the flute. + +Just sort of loop it around. + +I didn't explicitly say what +notes were longer than others. + +But in the middle there +I've got these three notes + +which I kind of wanted everyone +to get in on, specifically. + +AUDIENCE: Those +notes specifically, + +like those exact notes? + +AUDIENCE: Oh, yeah, +specifically those notes. + +So everyone play like +in unison, or as you + +get further along, yeah. + +AUDIENCE: So we should +all play the whole time, + +but those three notes, we +play the notes in unison? + +AUDIENCE: Everyone's +playing the whole time. + +Maybe at the start, actually, +the first time through, + +just the piano. + +And then when you loop +around, then you guys come in. + +And for you guys, +so it's E Phrygian. + +Stick with the E +most of the time, + +but also at least at the start +bring in the A and the B, + +specifically. + +And it's not [INAUDIBLE]. + +AUDIENCE: Can we play the +mode all the time, too? + +It's just one at a time? + +Do you know? + +AUDIENCE: It's just all the +white notes, from E to E. + +[INSTRUMENTS WARMING UP] + +[FLUTE AND PIANO PLAYING] + +[TRUMPET AND BANJO ENTER] + +[APPLAUSE] + +PROFESSOR: Very nice. + +And so was this one +mode or two modes? + +AUDIENCE: No, that's just +one mode, just the E Phrygian + +throughout. + +PROFESSOR: Just one mode. + +Very nice. + +Very nice. + +And was your part prescribed, +or were you improvising? + +AUDIENCE: So there +were three notes sort + +of in the middle of that. + +The do do do do do, +do do do do do do do. + +I guess I'm not quite +singing it in key But, yeah. + +So there were three +notes where every time it + +was prescribed, other +than that, improvising. + +PROFESSOR: OK, good. + +And the same for +you other folks? + +Very nice. + +Very nice. + +But you were playing the melody. + +AUDIENCE: I had +the melody, yeah. + +PROFESSOR: Very nice. + +Good. + +Good, good. + +[VIOLIN AND GUITAR PLAYING] + +[APPLAUSE] + +PROFESSOR: Very nice. + +So you actually had chords +written down, chords symboled, + +which is an +interesting way to go. + +We haven't had that yet +today, I don't think. + +We might have, did you +have chords in yours? + +AUDIENCE: Yeah. + +PROFESSOR: Because I was +going to write that on top. + +I did want to +mention some on that. + +So that's an interesting +way to think about it. + +And we can explore +this a little more. + +I don't want to take time now. + +But that's an interesting +way to think about it. + +It's another facet. + +Just try this. + +Take those first five +notes, and play them + +a little more like a +rhythmical idea, like this. + +Bop, ba bo be bop. + +[VIOLIN AND GUITAR PLAYING] + +And then the next one. + +[VIOLIN AND GUITAR PLAYING] And +then the next five, same way. + +Bop, ba doo be doo. + +[VIOLIN AND GUITAR PLAYING] And +the next, bop, ba da be dop. + +[VIOLIN AND GUITAR PLAYING] +Yeah, + +just do that do that +over and over again. + +And Alex, play those same +chords, but in time now. + +So I'm going to count +this off. [CLAPPING] One, + +two, one, two, three, four. + +[CLAPPING AND INSTRUMENTS + PLAYING] + +OK. + +I'm just showing that because +this would be another way + +to make a variation +of what you'd done. + +In other words, +similar to Silent Way, + +you've got your +lyrical thing up front. + +And then you could turn it +into a rhythmical gesture, + +let's say. + +And if you had yet +a third instrument, + +you guys could be essentially +the rhythm section, + +and somebody else, +oboe, whatever, flute, + +could take a solo +on top of that. + +It's just another thing to think +about in terms of extension. + +Very nice. + +Very nice. + +[FLUTE PLAYING] + +[GUITAR ENTERS] + +[APPLAUSE] + +PROFESSOR: Now, did you +have a written part? + +AUDIENCE: No. + +PROFESSOR: You were just +making something up. + +AUDIENCE: I was making that up. + +PROFESSOR: You were improvising. + +In other words, you +were playing this. + +So you had a rhythmical +scheme, but you + +didn't put a meter with it. + +So it wasn't like 4 4 or 6. + +That was very nice. + +Very nice. + +I was figuring you'd keep +going until one of you dropped, + +mainly you, because you +have to keep breathing. + +But that was really nice. + +That was really nice. + +We could've gotten +everybody involved in that. + +That would have taken +up about an hour. + +That would have been great. + +So just something to remember. + +If you get hired +for a job sometime + +and you run out of +material, you can always + +do something like this. + +You can fill up easily +5 minutes, 30 minutes, + +and you're golden. + +So if you run out of your set +list, just a practical tip. + +Very nice. + +So if you want to put your name +on that and let me have that. + +So I guess you guys have to run. + +While they're leaving +and the next person + +decides who wants +to be, I just want + +to say a thing about chords. + +And I know, Jacob, +this is your piece. + +So I don't want to say anything. + +But you had said +D Dorian, you also + +put D minor, D minor +chord, to indicate + +you wanted a D minor chord. + +And that's fine. + +That's perfectly fine. + +Sometimes-- and you see this +on the lead sheet for So What, + +which we looked at, +and we've studied it-- + +it'll say D Dorian D minor 7. + +It's a shorthand for +saying that's a chord that + +works with the D Dorian scale. + +But in fact, it's often +not so good to use this. + +It's much better +just to put the mode, + +because if you do that, then +the piano player's immediately + +going to think, let +me play that four note + +chord, which is triads. + +And triads, remember, +is not the sound + +that we typically +want with modal. + +We want a quartal, like +a fourth base thing. + +So when people do this and +they put that down there, + +sometimes you're sort of +snapped into that other way + +of thinking. + +It's not that it's wrong. + +It's just not quite +into the idiom + +of what we're trying +to do with modal stuff. + +So OK. + +Thank you all. + +So who would like to go next? + +AUDIENCE: I guess we can +start with a saxophone melody. + +There's like a vague rhythm, +but you can definitely + +change that, especially +after the first run-through. + +Electric guitar, +you'd start out just + +like emphasizing the D and +any other notes basically + +you feel like, and +then you can basically + +transition to the +melody yourself + +whenever you feel like it. + +And feel free to change +up the notes [INAUDIBLE]. + +[SAXOPHONE PLAYING] + +[ELECTRIC GUITAR ENTERS] + +[APPLAUSE] + +PROFESSOR: So that +again, that was + +like, what, a single +melody and that's all. + +Just some verbal +instructions to-- Very good. + +Very nice. + +Very nicely played. + +OK let's keep moving along. + +And I want to urge +us, if we could + +make the presentation +just a little bit shorter, + +just to make sure +everybody gets a chance + +to have their thing heard. + +So who would like to go next? + +AUDIENCE: Alright. + +So this for a flute and a piano. + +So it's Dorian. + +And it's just a basic melody. + +So what I wanted +was like the flute + +to just like start the +melody and just keep + +looping back through it. + +And it has a rhythm. + +And then I wanted the +piano to just, I guess, + +add their own +improvisation to it. + +[FLUTE PLAYING] + +[PIANO ENTERS] + +[APPLAUSE] + +PROFESSOR: Very nice. + +Piano, what were you doing? + +Were you leading +off what that was? + +Were you reading +off that melody? + +AUDIENCE: Yeah, so +I was trying to sort + +of align the rhythms, +playing mostly the fourths. + +PROFESSOR: So you +were making that up, + +the fourth idea, but +you were following that. + +AUDIENCE: Yeah, I didn't +play any of melody. + +I was just sort of +trying to match it. + +PROFESSOR: Who did that sound +like to you, or anybody else? + +What did that sound like, +that piano and flute playing + +together? + +AUDIENCE: Rite of Spring. + +PROFESSOR: Little +bit, little bit. + +Anybody else, classical, +any other classical? + +Sounded very much +like a Ravel to me. + +And in the Kind +of Blue situation, + +I don't know if you've read +the pages that were up there. + +I don't know if this was in +those pages I put on Stellar. + +It talked about how both +Bill Evans and Miles + +Davis adored Ravel. + +And that in fact, +when they would + +listen to music in +their own apartments, + +that's who they often +would listen to. + +Interesting for a jazz person. + +And that that was very +definitely in Bill Evans' mind. + +So you're channeling this. + +So this is great. + +It was beautiful. + +Beautiful flute playing. + +Very, very nice idea. + +Really nice idea. + +Wonderful. + +And I'm getting a kick out of +the fact that most of you guys + +are not playing +on your own piece. + +That's very interesting. + +Because you want to +hear what's going on. + +I understand that. + +AUDIENCE: So basically +I would like the guitar + +to start off playing the +melody and kind of set + +up a cycle of some sort. + +And then I'd like Sarah to +improvise over his melody, + +but starting with notes +beginning from right to left, + +if that's OK. + +I hope it works. + +I'm not exactly sure yet. + +And then I would like +you to play, I guess, + +whatever cycle he sets up if +you could just play chords + +under it, but I guess I'd like +half to be your own, yeah. + +[GUITAR PLAYING] + +[FLUTE AND PIANO ENTER] + +[APPLAUSE] + +PROFESSOR: Very nice. + +And again, you +didn't sing on this. + +That's very interesting. + +I was sure you were going to. + +AUDIENCE: Oh, no. + +That's fine. + +PROFESSOR: That was very nice. + +And actually I think +it's interesting + +how these are just +emerging, just + +by the way people +are volunteering. + +But this sort of could +be a perfect complement + +to what your piece was. + +I mean it would +make sense to me. + +And some of the +rhythmical people, you + +were clearly on a similar wave. + +AUDIENCE: So sax is +going to play the melody, + +and the rest of +us will just play + +like soft chords in D Dorian. + +I wrote out a pretty +specific rhythm, + +but you can take whatever +liberty you want. + +AUDIENCE: What is this? + +AUDIENCE: This is just +the transposition of that. + +AUDIENCE: That makes sense, OK. + +AUDIENCE: So it +should be D minor. + +[INSTRUMENTS PLAYING] + +[APPLAUSE] + +PROFESSOR: Very nice, very nice. + +I feel we're in the realm of +French impressionistic music, + +here. + +This is lovely. + +Very peaceful. + +Did that work like +you thought it would, + +except for the transposition? + +AUDIENCE: Pretty much, yeah. + +Just in a different key. + +There was one note +that was, I don't know. + +This one. + +I don't know what +happened to that, but. + +AUDIENCE: Yeah. + +So where I was doing B +Dorian on the sax, that + +should have been a +G sharp, I think, + +so I just made that change. + +But yeah, it did +sound kind of weird. + +AUDIENCE: But the general was +basically what I was going for. + +PROFESSOR: Very nice. + +Very nice. + +OK, who wants to go next? + +Of our remaining contestants. + +[PIANO PLAYING] + +[FLUTE AND OBOE ENTER] + +[APPLAUSE] + +PROFESSOR: Really nice. + +So if I got from +your instructions, + +sort of like intertwining +or interlocking segments, + +is that the idea? + +AUDIENCE: Yeah, that was kind +of again that train wreck. + +I think I need to +fix my reed up. + +But that's sounded really nice. + +And I expected it, +and it was cool. + +PROFESSOR: Yeah. + +Really, really nice. + +Very well done. + +[PIANO PLAYING] + +[TRUMPET ENTERS] + +[SAXOPHONE ENTERS] + +[APPLAUSE] + +AUDIENCE: Very nice, very nice. + +Cool. + +Cool. + +AUDIENCE: So I don't +have anything written. + +I'm just going, I guess, for +more of an open conception. + +But I was thinking just me +and piano, if that's good. + +So I was thinking in D Dorian. + +So the only real, like, +solid concept, I have, + +like, something of a melody. + +[SAXOPHONE PLAYING] + +AUDIENCE: So I +guess I was thinking + +I would just kind +of riff off of that. + +And I wanted it to have kind +of like a minor sound, I guess. + +So I don't know, I +guess you kind of do + +what you want with it. + +AUDIENCE: Do you want like a +beat, or just sort of chords? + +AUDIENCE: I mean, I +guess more of chords. + +Yeah. + +So I guess you can start it off. + +[PIANO PLAYING] + +[SAXOPHONE ENTERS] + +[APPLAUSE] + +PROFESSOR: Very nice, very nice. + +And I was waiting for +someone to do this, not + +have anything written down. + +AUDIENCE: Yeah. + +I can get something +to you next week. + +PROFESSOR: No, no no. + +But I was waiting for +that, because that's often + +how our improvisational +conceptions generate. + +I mean, I ask you to +come up with something. + +But I don't think I +said write it down. + +I said come up with something. + +And writing it down +is perfectly fine. + +And yours was almost all hand +written with a couple notes. + +Other people had just the notes. + +Other people had some +notes and chords. + +Any of these are fine. + +But they just give +us a generative point + +from which the work. + +So it was very cool. + +And obviously, what happened +in each of these instances + +was way more than +what you had on paper. + +That's the idea. + +In other words, +these are wonderful. + +And if you didn't +give me one of these, + +and you had it as a written +out form, I need to see that. + +But the point is what happened +in the room is the music. + +That's the music. + +These were all starting points. + +These were all springboards. + +So you're all doing wonderfully. + +So give yourselves a +round of applause, really. + +Really nice. + +Really nice. + +[APPLAUSE] + +PROFESSOR: So that's it. \ No newline at end of file diff --git a/_kKIQ1h9UuA.txt b/_kKIQ1h9UuA.txt new file mode 100644 index 0000000000000000000000000000000000000000..c63b218e3cd65059be7b02b9bb6a0c3bbd2b3fdc --- /dev/null +++ b/_kKIQ1h9UuA.txt @@ -0,0 +1,11147 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT OpenCourseWare continue to + + align:start position:0% +will help MIT OpenCourseWare continue to + + + align:start position:0% +will help MIT OpenCourseWare continue to +offer high quality educational resources + + align:start position:0% +offer high quality educational resources + + + align:start position:0% +offer high quality educational resources +for free + + align:start position:0% +for free + + + align:start position:0% +for free +to make a donation or to view additional + + align:start position:0% +to make a donation or to view additional + + + align:start position:0% +to make a donation or to view additional +materials from hundreds of MIT courses + + align:start position:0% +materials from hundreds of MIT courses + + + align:start position:0% +materials from hundreds of MIT courses +visit MIT opencourseware at ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +so let's get started okay so this is + + align:start position:0% +so let's get started okay so this is + + + align:start position:0% +so let's get started okay so this is +actually I will go for a os3 so you can + + align:start position:0% +actually I will go for a os3 so you can + + + align:start position:0% +actually I will go for a os3 so you can +see during the exam number one we have + + align:start position:0% +see during the exam number one we have + + + align:start position:0% +see during the exam number one we have +covered the first half of the goal and + + align:start position:0% +covered the first half of the goal and + + + align:start position:0% +covered the first half of the goal and +we I should be making progress to learn + + align:start position:0% +we I should be making progress to learn + + + align:start position:0% +we I should be making progress to learn +about boundary conditions in one + + align:start position:0% +about boundary conditions in one + + + align:start position:0% +about boundary conditions in one +dimensional system and also in two + + align:start position:0% +dimensional system and also in two + + + align:start position:0% +dimensional system and also in two +dimensional system today and we will + + align:start position:0% +dimensional system today and we will + + + align:start position:0% +dimensional system today and we will +actually talk about phenomena related to + + align:start position:0% +actually talk about phenomena related to + + + align:start position:0% +actually talk about phenomena related to +electromagnetic waves and the optics + + align:start position:0% +electromagnetic waves and the optics + + + align:start position:0% +electromagnetic waves and the optics +today which we will be able to learn a + + align:start position:0% +today which we will be able to learn a + + + align:start position:0% +today which we will be able to learn a +two very important fundamental law + + align:start position:0% +two very important fundamental law + + + align:start position:0% +two very important fundamental law +related to optical optical related to + + align:start position:0% +related to optical optical related to + + + align:start position:0% +related to optical optical related to +geometrical optics okay so that's + + align:start position:0% +geometrical optics okay so that's + + + align:start position:0% +geometrical optics okay so that's +actually the excitement and we started a + + align:start position:0% +actually the excitement and we started a + + + align:start position:0% +actually the excitement and we started a +discussion of two dimensional or three + + align:start position:0% +discussion of two dimensional or three + + + align:start position:0% +discussion of two dimensional or three +dimensional wave last time and actually + + align:start position:0% +dimensional wave last time and actually + + + align:start position:0% +dimensional wave last time and actually +it just in case you haven't realized + + align:start position:0% +it just in case you haven't realized + + + align:start position:0% +it just in case you haven't realized +that there are two ways to go to higher + + align:start position:0% +that there are two ways to go to higher + + + align:start position:0% +that there are two ways to go to higher +dimension okay so the first the first + + align:start position:0% +dimension okay so the first the first + + + align:start position:0% +dimension okay so the first the first +way is to increase the number of objects + + align:start position:0% +way is to increase the number of objects + + + align:start position:0% +way is to increase the number of objects +and the press that in two dimensional + + align:start position:0% +and the press that in two dimensional + + + align:start position:0% +and the press that in two dimensional +three dimensional space and that is + + align:start position:0% +three dimensional space and that is + + + align:start position:0% +three dimensional space and that is +actually the kind of things which we + + align:start position:0% +actually the kind of things which we + + + align:start position:0% +actually the kind of things which we +will discuss today so for example I can + + align:start position:0% +will discuss today so for example I can + + + align:start position:0% +will discuss today so for example I can +have particles arranged in two dimension + + align:start position:0% +have particles arranged in two dimension + + + align:start position:0% +have particles arranged in two dimension +which form membranes and we can also on + + align:start position:0% +which form membranes and we can also on + + + align:start position:0% +which form membranes and we can also on +the other hand change the direction of + + align:start position:0% +the other hand change the direction of + + + align:start position:0% +the other hand change the direction of +the electromagnetic wave for example as + + align:start position:0% +the electromagnetic wave for example as + + + align:start position:0% +the electromagnetic wave for example as +a function of time and that's another + + align:start position:0% +a function of time and that's another + + + align:start position:0% +a function of time and that's another +way to go to a higher dimension and + + align:start position:0% +way to go to a higher dimension and + + + align:start position:0% +way to go to a higher dimension and +today as I mentioned before we are going + + align:start position:0% +today as I mentioned before we are going + + + align:start position:0% +today as I mentioned before we are going +to talk about the first case and on the + + align:start position:0% +to talk about the first case and on the + + + align:start position:0% +to talk about the first case and on the +on Thursday we are going to talk about + + align:start position:0% +on Thursday we are going to talk about + + + align:start position:0% +on Thursday we are going to talk about +the second way to go to higher dimension + + align:start position:0% +the second way to go to higher dimension + + + align:start position:0% +the second way to go to higher dimension +which is related to polarization etc + + align:start position:0% +which is related to polarization etc + + + align:start position:0% +which is related to polarization etc +okay + + align:start position:0% +okay + + + align:start position:0% +okay +in general higher order dimensions are + + align:start position:0% +in general higher order dimensions are + + + align:start position:0% +in general higher order dimensions are +hopeless okay they are super complicated + + align:start position:0% +hopeless okay they are super complicated + + + align:start position:0% +hopeless okay they are super complicated +and in general we don't really know how + + align:start position:0% +and in general we don't really know how + + + align:start position:0% +and in general we don't really know how +to solve this kind of system fortunately + + align:start position:0% +to solve this kind of system fortunately + + + align:start position:0% +to solve this kind of system fortunately +okay in ls3 what we have been doing is a + + align:start position:0% +okay in ls3 what we have been doing is a + + + align:start position:0% +okay in ls3 what we have been doing is a +focusing on a small subset of questions + + align:start position:0% +focusing on a small subset of questions + + + align:start position:0% +focusing on a small subset of questions +which are actually highly symmetric + + align:start position:0% +which are actually highly symmetric + + + align:start position:0% +which are actually highly symmetric +therefore we can actually solve it + + align:start position:0% +therefore we can actually solve it + + + align:start position:0% +therefore we can actually solve it +analytically so that would be the focus + + align:start position:0% +analytically so that would be the focus + + + align:start position:0% +analytically so that would be the focus +of all three and so that we can actually + + align:start position:0% +of all three and so that we can actually + + + align:start position:0% +of all three and so that we can actually +learn some physics intuition out of this + + align:start position:0% +learn some physics intuition out of this + + + align:start position:0% +learn some physics intuition out of this +kind of highly idealized system and the + + align:start position:0% +kind of highly idealized system and the + + + align:start position:0% +kind of highly idealized system and the +system which we are going to focus on + + align:start position:0% +system which we are going to focus on + + + align:start position:0% +system which we are going to focus on +today is showing here it's a two + + align:start position:0% +today is showing here it's a two + + + align:start position:0% +today is showing here it's a two +dimensional system which you have array + + align:start position:0% +dimensional system which you have array + + + align:start position:0% +dimensional system which you have array +of masses pressing the X and y XY plane + + align:start position:0% +of masses pressing the X and y XY plane + + + align:start position:0% +of masses pressing the X and y XY plane +and and that is essentially the system + + align:start position:0% +and and that is essentially the system + + + align:start position:0% +and and that is essentially the system +we are going to solve today and we will + + align:start position:0% +we are going to solve today and we will + + + align:start position:0% +we are going to solve today and we will +see that we learned a lot of interesting + + align:start position:0% +see that we learned a lot of interesting + + + align:start position:0% +see that we learned a lot of interesting +phenomena coming from the solution of + + align:start position:0% +phenomena coming from the solution of + + + align:start position:0% +phenomena coming from the solution of +this kind of system before we start a + + align:start position:0% +this kind of system before we start a + + + align:start position:0% +this kind of system before we start a +discussion of two dimensional system I + + align:start position:0% +discussion of two dimensional system I + + + align:start position:0% +discussion of two dimensional system I +would like to remind you what we have + + align:start position:0% +would like to remind you what we have + + + align:start position:0% +would like to remind you what we have +already learned from lecture eight so + + align:start position:0% +already learned from lecture eight so + + + align:start position:0% +already learned from lecture eight so +that was about a system with which + + align:start position:0% +that was about a system with which + + + align:start position:0% +that was about a system with which +consists of infinite number of mass and + + align:start position:0% +consists of infinite number of mass and + + + align:start position:0% +consists of infinite number of mass and +the infinite number of strings and each + + align:start position:0% +the infinite number of strings and each + + + align:start position:0% +the infinite number of strings and each +string have string tension P and the + + align:start position:0% +string have string tension P and the + + + align:start position:0% +string have string tension P and the +other mass when they are in equilibrium + + align:start position:0% +other mass when they are in equilibrium + + + align:start position:0% +other mass when they are in equilibrium +position they the distance between all + + align:start position:0% +position they the distance between all + + + align:start position:0% +position they the distance between all +those mass in the X Direction is a ok so + + align:start position:0% +those mass in the X Direction is a ok so + + + align:start position:0% +those mass in the X Direction is a ok so +we have solved this system before with + + align:start position:0% +we have solved this system before with + + + align:start position:0% +we have solved this system before with +space translation symmetry okay and this + + align:start position:0% +space translation symmetry okay and this + + + align:start position:0% +space translation symmetry okay and this +is just a reminder that the dispersion + + align:start position:0% +is just a reminder that the dispersion + + + align:start position:0% +is just a reminder that the dispersion +relation which we got a lot of time + + align:start position:0% +relation which we got a lot of time + + + align:start position:0% +relation which we got a lot of time +Omega as a function of K is T over N a + + align:start position:0% +Omega as a function of K is T over N a + + + align:start position:0% +Omega as a function of K is T over N a +sign a ka over 2 so that was just a + + align:start position:0% +sign a ka over 2 so that was just a + + + align:start position:0% +sign a ka over 2 so that was just a +reminder of what we have learned from + + align:start position:0% +reminder of what we have learned from + + + align:start position:0% +reminder of what we have learned from +lecture 8 so by now you should realize + + align:start position:0% +lecture 8 so by now you should realize + + + align:start position:0% +lecture 8 so by now you should realize +that okay this dispersion relation is is + + align:start position:0% +that okay this dispersion relation is is + + + align:start position:0% +that okay this dispersion relation is is +young Angelou right this is actually + + align:start position:0% +young Angelou right this is actually + + + align:start position:0% +young Angelou right this is actually +telling you that this is a dispersive + + align:start position:0% +telling you that this is a dispersive + + + align:start position:0% +telling you that this is a dispersive +medium right because if you calculate + + align:start position:0% +medium right because if you calculate + + + align:start position:0% +medium right because if you calculate +the ratio of Omega n K you see that this + + align:start position:0% +the ratio of Omega n K you see that this + + + align:start position:0% +the ratio of Omega n K you see that this +is actually not a constant okay so the + + align:start position:0% +is actually not a constant okay so the + + + align:start position:0% +is actually not a constant okay so the +after all the discussion from previous + + align:start position:0% +after all the discussion from previous + + + align:start position:0% +after all the discussion from previous +lecture you should be able to + + align:start position:0% +lecture you should be able to + + + align:start position:0% +lecture you should be able to +immediately realize that and any waves + + align:start position:0% +immediately realize that and any waves + + + align:start position:0% +immediately realize that and any waves +propagating on this car + + align:start position:0% +propagating on this car + + + align:start position:0% +propagating on this car +the sister will be there will be a + + align:start position:0% +the sister will be there will be a + + + align:start position:0% +the sister will be there will be a +dispersion phenomena happening in this + + align:start position:0% +dispersion phenomena happening in this + + + align:start position:0% +dispersion phenomena happening in this +kind of system okay and also from the + + align:start position:0% +kind of system okay and also from the + + + align:start position:0% +kind of system okay and also from the +previous lecture we'll have learned that + + align:start position:0% +previous lecture we'll have learned that + + + align:start position:0% +previous lecture we'll have learned that +the eigenvectors based on space + + align:start position:0% +the eigenvectors based on space + + + align:start position:0% +the eigenvectors based on space +translation symmetry it's exponential I + + align:start position:0% +translation symmetry it's exponential I + + + align:start position:0% +translation symmetry it's exponential I +K X where X is actually defined as a + + align:start position:0% +K X where X is actually defined as a + + + align:start position:0% +K X where X is actually defined as a +times a we'll say is actually a label to + + align:start position:0% +times a we'll say is actually a label to + + + align:start position:0% +times a we'll say is actually a label to +tell you what which mass I was talking + + align:start position:0% +tell you what which mass I was talking + + + align:start position:0% +tell you what which mass I was talking +about okay now today we are going to + + align:start position:0% +about okay now today we are going to + + + align:start position:0% +about okay now today we are going to +extend this to a two dimensional system + + align:start position:0% +extend this to a two dimensional system + + + align:start position:0% +extend this to a two dimensional system +so so instead of a one dimensional + + align:start position:0% +so so instead of a one dimensional + + + align:start position:0% +so so instead of a one dimensional +system we have a two dimensional array + + align:start position:0% +system we have a two dimensional array + + + align:start position:0% +system we have a two dimensional array +so all the little mass or have mass + + align:start position:0% +so all the little mass or have mass + + + align:start position:0% +so all the little mass or have mass +equal to n and they are placing a XY + + align:start position:0% +equal to n and they are placing a XY + + + align:start position:0% +equal to n and they are placing a XY +plane okay the coordinate system which I + + align:start position:0% +plane okay the coordinate system which I + + + align:start position:0% +plane okay the coordinate system which I +defined is here X is horizontal and Y is + + align:start position:0% +defined is here X is horizontal and Y is + + + align:start position:0% +defined is here X is horizontal and Y is +vertical and the Z's as she pointing to + + align:start position:0% +vertical and the Z's as she pointing to + + + align:start position:0% +vertical and the Z's as she pointing to +you okay and all those little mass can + + align:start position:0% +you okay and all those little mass can + + + align:start position:0% +you okay and all those little mass can +only oscillate toward you or going away + + align:start position:0% +only oscillate toward you or going away + + + align:start position:0% +only oscillate toward you or going away +from you so in the Z direction okay you + + align:start position:0% +from you so in the Z direction okay you + + + align:start position:0% +from you so in the Z direction okay you +can only up also they have been done in + + align:start position:0% +can only up also they have been done in + + + align:start position:0% +can only up also they have been done in +the Z direction okay and in this system + + align:start position:0% +the Z direction okay and in this system + + + align:start position:0% +the Z direction okay and in this system +we have the land scale which is actually + + align:start position:0% +we have the land scale which is actually + + + align:start position:0% +we have the land scale which is actually +the horizontal distance between mass is + + align:start position:0% +the horizontal distance between mass is + + + align:start position:0% +the horizontal distance between mass is +it's called aah + + align:start position:0% +it's called aah + + + align:start position:0% +it's called aah +and in the vertical direction the scale + + align:start position:0% +and in the vertical direction the scale + + + align:start position:0% +and in the vertical direction the scale +at the tip distance between mass is AV + + align:start position:0% +at the tip distance between mass is AV + + + align:start position:0% +at the tip distance between mass is AV +okay also we have string tension a two + + align:start position:0% +okay also we have string tension a two + + + align:start position:0% +okay also we have string tension a two +different kind of string tension for the + + align:start position:0% +different kind of string tension for the + + + align:start position:0% +different kind of string tension for the +vertical and horizontal direction the + + align:start position:0% +vertical and horizontal direction the + + + align:start position:0% +vertical and horizontal direction the +vertical direction you have string + + align:start position:0% +vertical direction you have string + + + align:start position:0% +vertical direction you have string +tension TV and in the horizontal + + align:start position:0% +tension TV and in the horizontal + + + align:start position:0% +tension TV and in the horizontal +direction you have string tension th + + align:start position:0% +direction you have string tension th + + + align:start position:0% +direction you have string tension th +okay so how do we actually describe this + + align:start position:0% +okay so how do we actually describe this + + + align:start position:0% +okay so how do we actually describe this +kind of system right the first thing as + + align:start position:0% +kind of system right the first thing as + + + align:start position:0% +kind of system right the first thing as +we did before is to label all those + + align:start position:0% +we did before is to label all those + + + align:start position:0% +we did before is to label all those +little mass right by my label and my + + align:start position:0% +little mass right by my label and my + + + align:start position:0% +little mass right by my label and my +label is actually called say X and say Y + + align:start position:0% +label is actually called say X and say Y + + + align:start position:0% +label is actually called say X and say Y +which actually tells you + + align:start position:0% +which actually tells you + + + align:start position:0% +which actually tells you +which mass I was talking about in this + + align:start position:0% +which mass I was talking about in this + + + align:start position:0% +which mass I was talking about in this +system okay + + align:start position:0% +system okay + + + align:start position:0% +system okay +once I have defined that the labels I + + align:start position:0% +once I have defined that the labels I + + + align:start position:0% +once I have defined that the labels I +will be able to write the position of + + align:start position:0% +will be able to write the position of + + + align:start position:0% +will be able to write the position of +all those mass the x-direction position + + align:start position:0% +all those mass the x-direction position + + + align:start position:0% +all those mass the x-direction position +and y-direction position in terms of say + + align:start position:0% +and y-direction position in terms of say + + + align:start position:0% +and y-direction position in terms of say +and a right so for example x position of + + align:start position:0% +and a right so for example x position of + + + align:start position:0% +and a right so for example x position of +one of the mass will be written as say x + + align:start position:0% +one of the mass will be written as say x + + + align:start position:0% +one of the mass will be written as say x +times a h and the y position of a + + align:start position:0% +times a h and the y position of a + + + align:start position:0% +times a h and the y position of a +specific mass you can actually write it + + align:start position:0% +specific mass you can actually write it + + + align:start position:0% +specific mass you can actually write it +down in terms of say Y times AP okay so + + align:start position:0% +down in terms of say Y times AP okay so + + + align:start position:0% +down in terms of say Y times AP okay so +all those things are to be pretty + + align:start position:0% +all those things are to be pretty + + + align:start position:0% +all those things are to be pretty +straightforward the interesting part is + + align:start position:0% +straightforward the interesting part is + + + align:start position:0% +straightforward the interesting part is +that as we actually identify in a last + + align:start position:0% +that as we actually identify in a last + + + align:start position:0% +that as we actually identify in a last +lecture this system is highly symmetric + + align:start position:0% +lecture this system is highly symmetric + + + align:start position:0% +lecture this system is highly symmetric +it has space translation symmetry right + + align:start position:0% +it has space translation symmetry right + + + align:start position:0% +it has space translation symmetry right +therefore we can issue the immediately + + align:start position:0% +therefore we can issue the immediately + + + align:start position:0% +therefore we can issue the immediately +figure out won't be the eigenvectors for + + align:start position:0% +figure out won't be the eigenvectors for + + + align:start position:0% +figure out won't be the eigenvectors for +this system + + align:start position:0% +this system + + + align:start position:0% +this system +so the eigenvector very similar to what + + align:start position:0% +so the eigenvector very similar to what + + + align:start position:0% +so the eigenvector very similar to what +have been discussed here where you have + + align:start position:0% +have been discussed here where you have + + + align:start position:0% +have been discussed here where you have +a one dimensional state space + + align:start position:0% +a one dimensional state space + + + align:start position:0% +a one dimensional state space +translation symmetric system exponential + + align:start position:0% +translation symmetric system exponential + + + align:start position:0% +translation symmetric system exponential +I K X was the eigenvector now you have I + + align:start position:0% +I K X was the eigenvector now you have I + + + align:start position:0% +I K X was the eigenvector now you have I +can vector which is actually in two + + align:start position:0% +can vector which is actually in two + + + align:start position:0% +can vector which is actually in two +dimension right because you would like + + align:start position:0% +dimension right because you would like + + + align:start position:0% +dimension right because you would like +to describe not only the X direction but + + align:start position:0% +to describe not only the X direction but + + + align:start position:0% +to describe not only the X direction but +also y direction and the eigen vector + + align:start position:0% +also y direction and the eigen vector + + + align:start position:0% +also y direction and the eigen vector +have exactly the same functional form + + align:start position:0% +have exactly the same functional form + + + align:start position:0% +have exactly the same functional form +because of space translation symmetry + + align:start position:0% +because of space translation symmetry + + + align:start position:0% +because of space translation symmetry +and it's actually like explanation I KX + + align:start position:0% +and it's actually like explanation I KX + + + align:start position:0% +and it's actually like explanation I KX +times X I multiply that by another + + align:start position:0% +times X I multiply that by another + + + align:start position:0% +times X I multiply that by another +explanation function exponential I K Y + + align:start position:0% +explanation function exponential I K Y + + + align:start position:0% +explanation function exponential I K Y +times y okay so I think from until now + + align:start position:0% +times y okay so I think from until now + + + align:start position:0% +times y okay so I think from until now +nothing should surprise surprise you + + align:start position:0% +nothing should surprise surprise you + + + align:start position:0% +nothing should surprise surprise you +because this is actually what we have + + align:start position:0% +because this is actually what we have + + + align:start position:0% +because this is actually what we have +learned from the one-dimensional system + + align:start position:0% +learned from the one-dimensional system + + + align:start position:0% +learned from the one-dimensional system +and asks + + align:start position:0% +and asks + + + align:start position:0% +and asks +based on what we have learned before we + + align:start position:0% +based on what we have learned before we + + + align:start position:0% +based on what we have learned before we +can also immediately write down what + + align:start position:0% +can also immediately write down what + + + align:start position:0% +can also immediately write down what +would be the dispersion relation since + + align:start position:0% +would be the dispersion relation since + + + align:start position:0% +would be the dispersion relation since +we are always considered in very small + + align:start position:0% +we are always considered in very small + + + align:start position:0% +we are always considered in very small +vibration okay + + align:start position:0% +vibration okay + + + align:start position:0% +vibration okay +and this actually these are formulas + + align:start position:0% +and this actually these are formulas + + + align:start position:0% +and this actually these are formulas +still a price therefore you can easily + + align:start position:0% +still a price therefore you can easily + + + align:start position:0% +still a price therefore you can easily +write down the dispersion relation + + align:start position:0% +write down the dispersion relation + + + align:start position:0% +write down the dispersion relation +already Omega square Omega square K + + align:start position:0% +already Omega square Omega square K + + + align:start position:0% +already Omega square Omega square K +would be equal to 4 th over mAh sine + + align:start position:0% +would be equal to 4 th over mAh sine + + + align:start position:0% +would be equal to 4 th over mAh sine +squared K X + H divided by 2 plus 4 T V + + align:start position:0% +squared K X + H divided by 2 plus 4 T V + + + align:start position:0% +squared K X + H divided by 2 plus 4 T V +divided by M a the sign a square k KY a + + align:start position:0% +divided by M a the sign a square k KY a + + + align:start position:0% +divided by M a the sign a square k KY a +v / ok so this is actually pretty + + align:start position:0% +v / ok so this is actually pretty + + + align:start position:0% +v / ok so this is actually pretty +straightforward and and you can see that + + align:start position:0% +straightforward and and you can see that + + + align:start position:0% +straightforward and and you can see that +another Omega is a function of both K X + + align:start position:0% +another Omega is a function of both K X + + + align:start position:0% +another Omega is a function of both K X +and the K Y from the icon from the + + align:start position:0% +and the K Y from the icon from the + + + align:start position:0% +and the K Y from the icon from the +eigenvector we can also write down what + + align:start position:0% +eigenvector we can also write down what + + + align:start position:0% +eigenvector we can also write down what +would be the possible sy X Y now the + + align:start position:0% +would be the possible sy X Y now the + + + align:start position:0% +would be the possible sy X Y now the +size is actually the displacement in the + + align:start position:0% +size is actually the displacement in the + + + align:start position:0% +size is actually the displacement in the +Z direction right we should spare to the + + align:start position:0% +Z direction right we should spare to the + + + align:start position:0% +Z direction right we should spare to the +equilibrium position and that is + + align:start position:0% +equilibrium position and that is + + + align:start position:0% +equilibrium position and that is +actually proportional to the eigenvector + + align:start position:0% +actually proportional to the eigenvector + + + align:start position:0% +actually proportional to the eigenvector +so basically is actually going to be a + + align:start position:0% +so basically is actually going to be a + + + align:start position:0% +so basically is actually going to be a +exponential I exercise X exponential I K + + align:start position:0% +exponential I exercise X exponential I K + + + align:start position:0% +exponential I exercise X exponential I K +Y times y ok and of course I can write + + align:start position:0% +Y times y ok and of course I can write + + + align:start position:0% +Y times y ok and of course I can write +these two turns together right so + + align:start position:0% +these two turns together right so + + + align:start position:0% +these two turns together right so +basically what I will get is a + + align:start position:0% +basically what I will get is a + + + align:start position:0% +basically what I will get is a +exponential I K is a vector times R + + align:start position:0% +exponential I K is a vector times R + + + align:start position:0% +exponential I K is a vector times R +which is a vector so basically K content + + align:start position:0% +which is a vector so basically K content + + + align:start position:0% +which is a vector so basically K content +to component KX and KY + R have also to + + align:start position:0% +to component KX and KY + R have also to + + + align:start position:0% +to component KX and KY + R have also to +company with + + align:start position:0% +company with + + + align:start position:0% +company with +and what okay again we see that this is + + align:start position:0% +and what okay again we see that this is + + + align:start position:0% +and what okay again we see that this is +actually a non-dispersive median okay + + align:start position:0% +actually a non-dispersive median okay + + + align:start position:0% +actually a non-dispersive median okay +and what we are going to do is to make + + align:start position:0% +and what we are going to do is to make + + + align:start position:0% +and what we are going to do is to make +linear combination of all those + + align:start position:0% +linear combination of all those + + + align:start position:0% +linear combination of all those +eigenvectors and the to figure out what + + align:start position:0% +eigenvectors and the to figure out what + + + align:start position:0% +eigenvectors and the to figure out what +would be the behavior of when this + + align:start position:0% +would be the behavior of when this + + + align:start position:0% +would be the behavior of when this +system is oscillating at a specific + + align:start position:0% +system is oscillating at a specific + + + align:start position:0% +system is oscillating at a specific +frequency Omega and that is actually the + + align:start position:0% +frequency Omega and that is actually the + + + align:start position:0% +frequency Omega and that is actually the +corresponding no more more at the + + align:start position:0% +corresponding no more more at the + + + align:start position:0% +corresponding no more more at the +angular frequency Omega okay so that is + + align:start position:0% +angular frequency Omega okay so that is + + + align:start position:0% +angular frequency Omega okay so that is +actually pretty similar to what we have + + align:start position:0% +actually pretty similar to what we have + + + align:start position:0% +actually pretty similar to what we have +done for a white dimensional system okay + + align:start position:0% +done for a white dimensional system okay + + + align:start position:0% +done for a white dimensional system okay +so just a reminder so this is a two + + align:start position:0% +so just a reminder so this is a two + + + align:start position:0% +so just a reminder so this is a two +dimensional system just a reminder about + + align:start position:0% +dimensional system just a reminder about + + + align:start position:0% +dimensional system just a reminder about +one dimensional system or for for a + + align:start position:0% +one dimensional system or for for a + + + align:start position:0% +one dimensional system or for for a +while so so that there are two eigen + + align:start position:0% +while so so that there are two eigen + + + align:start position:0% +while so so that there are two eigen +vectors which actually have identical + + align:start position:0% +vectors which actually have identical + + + align:start position:0% +vectors which actually have identical +Omega right so the first one is + + align:start position:0% +Omega right so the first one is + + + align:start position:0% +Omega right so the first one is +exponential I K X and the second one is + + align:start position:0% +exponential I K X and the second one is + + + align:start position:0% +exponential I K X and the second one is +actually exponential minus ikx what we + + align:start position:0% +actually exponential minus ikx what we + + + align:start position:0% +actually exponential minus ikx what we +have done before is to do a linear + + align:start position:0% +have done before is to do a linear + + + align:start position:0% +have done before is to do a linear +combination of the two explanation + + align:start position:0% +combination of the two explanation + + + align:start position:0% +combination of the two explanation +function right so what we can do is that + + align:start position:0% +function right so what we can do is that + + + align:start position:0% +function right so what we can do is that +okay now I can actually create cosine KX + + align:start position:0% +okay now I can actually create cosine KX + + + align:start position:0% +okay now I can actually create cosine KX +right this is actually 1 over 2 + + align:start position:0% +right this is actually 1 over 2 + + + align:start position:0% +right this is actually 1 over 2 +exponential I K X plus exponential minus + + align:start position:0% +exponential I K X plus exponential minus + + + align:start position:0% +exponential I K X plus exponential minus +ikx and I can also create sine KX and + + align:start position:0% +ikx and I can also create sine KX and + + + align:start position:0% +ikx and I can also create sine KX and +this is as u 1 over 2i exponential ikx + + align:start position:0% +this is as u 1 over 2i exponential ikx + + + align:start position:0% +this is as u 1 over 2i exponential ikx +minus exponential minus I K X right for + + align:start position:0% +minus exponential minus I K X right for + + + align:start position:0% +minus exponential minus I K X right for +this one-dimensional system so that + + align:start position:0% +this one-dimensional system so that + + + align:start position:0% +this one-dimensional system so that +issue how we figure out that this when + + align:start position:0% +issue how we figure out that this when + + + align:start position:0% +issue how we figure out that this when +this system is doing one of the normal + + align:start position:0% +this system is doing one of the normal + + + align:start position:0% +this system is doing one of the normal +mode the shape of the system is like a + + align:start position:0% +mode the shape of the system is like a + + + align:start position:0% +mode the shape of the system is like a +cosine or a sine or in general you can + + align:start position:0% +cosine or a sine or in general you can + + + align:start position:0% +cosine or a sine or in general you can +add these two together and in general it + + align:start position:0% +add these two together and in general it + + + align:start position:0% +add these two together and in general it +can be something like cosine KX plus Phi + + align:start position:0% +can be something like cosine KX plus Phi + + + align:start position:0% +can be something like cosine KX plus Phi +and Phi is actually some phase + + align:start position:0% +and Phi is actually some phase + + + align:start position:0% +and Phi is actually some phase +angle which we you can actually figure + + align:start position:0% +angle which we you can actually figure + + + align:start position:0% +angle which we you can actually figure +out by boundary condition okay but + + align:start position:0% +out by boundary condition okay but + + + align:start position:0% +out by boundary condition okay but +before we introduce any boundary + + align:start position:0% +before we introduce any boundary + + + align:start position:0% +before we introduce any boundary +condition all the K values all the five + + align:start position:0% +condition all the K values all the five + + + align:start position:0% +condition all the K values all the five +values are allowed right just a reminder + + align:start position:0% +values are allowed right just a reminder + + + align:start position:0% +values are allowed right just a reminder +about what we have learned before okay + + align:start position:0% +about what we have learned before okay + + + align:start position:0% +about what we have learned before okay +so the situation is pretty simple you + + align:start position:0% +so the situation is pretty simple you + + + align:start position:0% +so the situation is pretty simple you +have just plus n minus K and then you + + align:start position:0% +have just plus n minus K and then you + + + align:start position:0% +have just plus n minus K and then you +make linear combination of these two + + align:start position:0% +make linear combination of these two + + + align:start position:0% +make linear combination of these two +then you know what would be the shape of + + align:start position:0% +then you know what would be the shape of + + + align:start position:0% +then you know what would be the shape of +the normal mode okay on the other hand + + align:start position:0% +the normal mode okay on the other hand + + + align:start position:0% +the normal mode okay on the other hand +we are now talking about two-dimensional + + align:start position:0% +we are now talking about two-dimensional + + + align:start position:0% +we are now talking about two-dimensional +case okay so let's take a look at this + + align:start position:0% +case okay so let's take a look at this + + + align:start position:0% +case okay so let's take a look at this +dispersion relation okay + + align:start position:0% +dispersion relation okay + + + align:start position:0% +dispersion relation okay +the dispersion relation we have here + + align:start position:0% +the dispersion relation we have here + + + align:start position:0% +the dispersion relation we have here +Omega is a function of K X is a function + + align:start position:0% +Omega is a function of K X is a function + + + align:start position:0% +Omega is a function of K X is a function +of K Y as well okay what does that mean + + align:start position:0% +of K Y as well okay what does that mean + + + align:start position:0% +of K Y as well okay what does that mean +that means I can have multiple choice of + + align:start position:0% +that means I can have multiple choice of + + + align:start position:0% +that means I can have multiple choice of +KX and KY which they all produce the + + align:start position:0% +KX and KY which they all produce the + + + align:start position:0% +KX and KY which they all produce the +same Omega value okay so it's not as + + align:start position:0% +same Omega value okay so it's not as + + + align:start position:0% +same Omega value okay so it's not as +simple as this one anymore as you can + + align:start position:0% +simple as this one anymore as you can + + + align:start position:0% +simple as this one anymore as you can +see right because when I slightly + + align:start position:0% +see right because when I slightly + + + align:start position:0% +see right because when I slightly +increase KX okay what I could do is okay + + align:start position:0% +increase KX okay what I could do is okay + + + align:start position:0% +increase KX okay what I could do is okay +I can slightly reduce KY to compensate + + align:start position:0% +I can slightly reduce KY to compensate + + + align:start position:0% +I can slightly reduce KY to compensate +the difference therefore I can still + + align:start position:0% +the difference therefore I can still + + + align:start position:0% +the difference therefore I can still +keep Omega which is the angular + + align:start position:0% +keep Omega which is the angular + + + align:start position:0% +keep Omega which is the angular +frequency of the oscillation the same + + align:start position:0% +frequency of the oscillation the same + + + align:start position:0% +frequency of the oscillation the same +okay so that can be seen from this + + align:start position:0% +okay so that can be seen from this + + + align:start position:0% +okay so that can be seen from this +demonstration on the slide you can see + + align:start position:0% +demonstration on the slide you can see + + + align:start position:0% +demonstration on the slide you can see +that this is actually one example + + align:start position:0% +that this is actually one example + + + align:start position:0% +that this is actually one example +dispersion relation okay this is + + align:start position:0% +dispersion relation okay this is + + + align:start position:0% +dispersion relation okay this is +actually the formula which we have on + + align:start position:0% +actually the formula which we have on + + + align:start position:0% +actually the formula which we have on +the board and what about if I set all + + align:start position:0% +the board and what about if I set all + + + align:start position:0% +the board and what about if I set all +those parameter and get example Omega + + align:start position:0% +those parameter and get example Omega + + + align:start position:0% +those parameter and get example Omega +square equal to Phi sine square K X and + + align:start position:0% +square equal to Phi sine square K X and + + + align:start position:0% +square equal to Phi sine square K X and +the +5 a sine squared K Y okay so what + + align:start position:0% +the +5 a sine squared K Y okay so what + + + align:start position:0% +the +5 a sine squared K Y okay so what +what will happen okay if I set my aah T + + align:start position:0% +what will happen okay if I set my aah T + + + align:start position:0% +what will happen okay if I set my aah T +and the M value so that I have this + + align:start position:0% +and the M value so that I have this + + + align:start position:0% +and the M value so that I have this +example what will happen if I have that + + align:start position:0% +example what will happen if I have that + + + align:start position:0% +example what will happen if I have that +a dispersion relation + + align:start position:0% +a dispersion relation + + + align:start position:0% +a dispersion relation +so if I go ahead and the proper allowed + + align:start position:0% +so if I go ahead and the proper allowed + + + align:start position:0% +so if I go ahead and the proper allowed +KX and KY value which keep one you see + + align:start position:0% +KX and KY value which keep one you see + + + align:start position:0% +KX and KY value which keep one you see +very definitive of pattern right from + + align:start position:0% +very definitive of pattern right from + + + align:start position:0% +very definitive of pattern right from +this right so you can see that hot + + align:start position:0% +this right so you can see that hot + + + align:start position:0% +this right so you can see that hot +actually + + align:start position:0% +actually + + + align:start position:0% +actually +all those things on the circle can + + align:start position:0% +all those things on the circle can + + + align:start position:0% +all those things on the circle can +produce the angular frequency of Omega + + align:start position:0% +produce the angular frequency of Omega + + + align:start position:0% +produce the angular frequency of Omega +equal to one and what would be there + + align:start position:0% +equal to one and what would be there + + + align:start position:0% +equal to one and what would be there +yeah we all would be that no more more + + align:start position:0% +yeah we all would be that no more more + + + align:start position:0% +yeah we all would be that no more more +will be all possible linear combination + + align:start position:0% +will be all possible linear combination + + + align:start position:0% +will be all possible linear combination +of all those possible K X K Y pair you + + align:start position:0% +of all those possible K X K Y pair you + + + align:start position:0% +of all those possible K X K Y pair you +have a question yeah yes in general I + + align:start position:0% +have a question yeah yes in general I + + + align:start position:0% +have a question yeah yes in general I +think this you mean a circular shape or + + align:start position:0% +think this you mean a circular shape or + + + align:start position:0% +think this you mean a circular shape or +I think in general yes you need to have + + align:start position:0% +I think in general yes you need to have + + + align:start position:0% +I think in general yes you need to have +degeneracy right because you can put a + + align:start position:0% +degeneracy right because you can put a + + + align:start position:0% +degeneracy right because you can put a +shape of nappy circular for example hi + + align:start position:0% +shape of nappy circular for example hi + + + align:start position:0% +shape of nappy circular for example hi +so in general okay so it can be a + + align:start position:0% +so in general okay so it can be a + + + align:start position:0% +so in general okay so it can be a +general function which is up like a lot + + align:start position:0% +general function which is up like a lot + + + align:start position:0% +general function which is up like a lot +like the formula above right but you can + + align:start position:0% +like the formula above right but you can + + + align:start position:0% +like the formula above right but you can +still this argument still a price right + + align:start position:0% +still this argument still a price right + + + align:start position:0% +still this argument still a price right +so if you have some intermediate or make + + align:start position:0% +so if you have some intermediate or make + + + align:start position:0% +so if you have some intermediate or make +up value you can always site the + + align:start position:0% +up value you can always site the + + + align:start position:0% +up value you can always site the +increase or make ax and side it decrease + + align:start position:0% +increase or make ax and side it decrease + + + align:start position:0% +increase or make ax and side it decrease +KY and our still satisfy the same Omega + + align:start position:0% +KY and our still satisfy the same Omega + + + align:start position:0% +KY and our still satisfy the same Omega +value therefore all the normal modes + + align:start position:0% +value therefore all the normal modes + + + align:start position:0% +value therefore all the normal modes +with a specific Omega would be a linear + + align:start position:0% +with a specific Omega would be a linear + + + align:start position:0% +with a specific Omega would be a linear +combination all those possible no more + + align:start position:0% +combination all those possible no more + + + align:start position:0% +combination all those possible no more +more if you all those possible KX and KY + + align:start position:0% +more if you all those possible KX and KY + + + align:start position:0% +more if you all those possible KX and KY +pairs if you have an infinitely long + + align:start position:0% +pairs if you have an infinitely long + + + align:start position:0% +pairs if you have an infinitely long +system okay and that also applies to the + + align:start position:0% +system okay and that also applies to the + + + align:start position:0% +system okay and that also applies to the +other example when I have Omega equal to + + align:start position:0% +other example when I have Omega equal to + + + align:start position:0% +other example when I have Omega equal to +5 then you have slightly different + + align:start position:0% +5 then you have slightly different + + + align:start position:0% +5 then you have slightly different +behavior but the take-home message is + + align:start position:0% +behavior but the take-home message is + + + align:start position:0% +behavior but the take-home message is +that there are many many pairs of KX and + + align:start position:0% +that there are many many pairs of KX and + + + align:start position:0% +that there are many many pairs of KX and +KY which can create the same amount of + + align:start position:0% +KY which can create the same amount of + + + align:start position:0% +KY which can create the same amount of +Omega okay so that makes C's pretty + + align:start position:0% +Omega okay so that makes C's pretty + + + align:start position:0% +Omega okay so that makes C's pretty +complicated but they should be we can + + align:start position:0% +complicated but they should be we can + + + align:start position:0% +complicated but they should be we can +always still try to understand this by + + align:start position:0% +always still try to understand this by + + + align:start position:0% +always still try to understand this by +investigating all the possible care + + align:start position:0% +investigating all the possible care + + + align:start position:0% +investigating all the possible care +pairs of KX and KY and the other hand + + align:start position:0% +pairs of KX and KY and the other hand + + + align:start position:0% +pairs of KX and KY and the other hand +okay + + align:start position:0% +okay + + + align:start position:0% +okay +as what we have discussed before before + + align:start position:0% +as what we have discussed before before + + + align:start position:0% +as what we have discussed before before +you introduced boundary condition for + + align:start position:0% +you introduced boundary condition for + + + align:start position:0% +you introduced boundary condition for +the one-dimensional system okay + + align:start position:0% +the one-dimensional system okay + + + align:start position:0% +the one-dimensional system okay +they are infinite number of possible k + + align:start position:0% +they are infinite number of possible k + + + align:start position:0% +they are infinite number of possible k +value right all the possible K values + + align:start position:0% +value right all the possible K values + + + align:start position:0% +value right all the possible K values +are allowed but after you add boundary + + align:start position:0% +are allowed but after you add boundary + + + align:start position:0% +are allowed but after you add boundary +condition for example I add walls around + + align:start position:0% +condition for example I add walls around + + + align:start position:0% +condition for example I add walls around +this system okay so that I basically + + align:start position:0% +this system okay so that I basically + + + align:start position:0% +this system okay so that I basically +have fixed boundary condition so + + align:start position:0% +have fixed boundary condition so + + + align:start position:0% +have fixed boundary condition so +basically the boundary condition is that + + align:start position:0% +basically the boundary condition is that + + + align:start position:0% +basically the boundary condition is that +the amplitude at X equal to 0 y equal to + + align:start position:0% +the amplitude at X equal to 0 y equal to + + + align:start position:0% +the amplitude at X equal to 0 y equal to +0 or X equal to Phi a times H Phi aah + + align:start position:0% +0 or X equal to Phi a times H Phi aah + + + align:start position:0% +0 or X equal to Phi a times H Phi aah +or y equal to 4ei be okay at the + + align:start position:0% +or y equal to 4ei be okay at the + + + align:start position:0% +or y equal to 4ei be okay at the +boundary the amplitude has to be equal + + align:start position:0% +boundary the amplitude has to be equal + + + align:start position:0% +boundary the amplitude has to be equal +to 0 because it's attached to a wall + + align:start position:0% +to 0 because it's attached to a wall + + + align:start position:0% +to 0 because it's attached to a wall +right okay when this happened + + align:start position:0% + + + + align:start position:0% + +this means that we will have a 4 & 4 we + + align:start position:0% +this means that we will have a 4 & 4 we + + + align:start position:0% +this means that we will have a 4 & 4 we +have four walls which we have + + align:start position:0% +have four walls which we have + + + align:start position:0% +have four walls which we have +corresponding boundary condition so that + + align:start position:0% +corresponding boundary condition so that + + + align:start position:0% +corresponding boundary condition so that +means I have to satisfy this four + + align:start position:0% +means I have to satisfy this four + + + align:start position:0% +means I have to satisfy this four +boundary condition side zero Y evaluated + + align:start position:0% +boundary condition side zero Y evaluated + + + align:start position:0% +boundary condition side zero Y evaluated +at any time will be equal to sy LH y ki + + align:start position:0% +at any time will be equal to sy LH y ki + + + align:start position:0% +at any time will be equal to sy LH y ki +will be equal to side X 0 T will be + + align:start position:0% +will be equal to side X 0 T will be + + + align:start position:0% +will be equal to side X 0 T will be +equal to Phi X F V T and this all equal + + align:start position:0% +equal to Phi X F V T and this all equal + + + align:start position:0% +equal to Phi X F V T and this all equal +to 0 right so those are not not very + + align:start position:0% +to 0 right so those are not not very + + + align:start position:0% +to 0 right so those are not not very +difficult to understand those are issues + + align:start position:0% +difficult to understand those are issues + + + align:start position:0% +difficult to understand those are issues +just the four walls around this system + + align:start position:0% +just the four walls around this system + + + align:start position:0% +just the four walls around this system +okay once you have all those conditions + + align:start position:0% +okay once you have all those conditions + + + align:start position:0% +okay once you have all those conditions +okay and that I of course I define H + + align:start position:0% +okay and that I of course I define H + + + align:start position:0% +okay and that I of course I define H +will be equal to five times + + align:start position:0% +will be equal to five times + + + align:start position:0% +will be equal to five times +aah right because there are five times + + align:start position:0% +aah right because there are five times + + + align:start position:0% +aah right because there are five times +five strings between the two wars in + + align:start position:0% +five strings between the two wars in + + + align:start position:0% +five strings between the two wars in +the horizontal direction and of course I + + align:start position:0% +the horizontal direction and of course I + + + align:start position:0% +the horizontal direction and of course I +also have defined here air we will be + + align:start position:0% +also have defined here air we will be + + + align:start position:0% +also have defined here air we will be +four times equal to a times a B okay so + + align:start position:0% +four times equal to a times a B okay so + + + align:start position:0% +four times equal to a times a B okay so +once I have all those four boundary + + align:start position:0% +once I have all those four boundary + + + align:start position:0% +once I have all those four boundary +conditions in praise that means I cannot + + align:start position:0% +conditions in praise that means I cannot + + + align:start position:0% +conditions in praise that means I cannot +arbitrarily choose K value and the fact + + align:start position:0% +arbitrarily choose K value and the fact + + + align:start position:0% +arbitrarily choose K value and the fact +right otherwise I will not be able to + + align:start position:0% +right otherwise I will not be able to + + + align:start position:0% +right otherwise I will not be able to +satisfy these four boundary conditions + + align:start position:0% +satisfy these four boundary conditions + + + align:start position:0% +satisfy these four boundary conditions +okay so now we actually will be able to + + align:start position:0% +okay so now we actually will be able to + + + align:start position:0% +okay so now we actually will be able to +figure out that there will be only four + + align:start position:0% +figure out that there will be only four + + + align:start position:0% +figure out that there will be only four +modes okay in this two-dimensional + + align:start position:0% +modes okay in this two-dimensional + + + align:start position:0% +modes okay in this two-dimensional +problem which will give the same Omega + + align:start position:0% +problem which will give the same Omega + + + align:start position:0% +problem which will give the same Omega +what are the four possible note what are + + align:start position:0% +what are the four possible note what are + + + align:start position:0% +what are the four possible note what are +the four four possible eigen vectors + + align:start position:0% +the four four possible eigen vectors + + + align:start position:0% +the four four possible eigen vectors +those are a exponential plus or minus I + + align:start position:0% +those are a exponential plus or minus I + + + align:start position:0% +those are a exponential plus or minus I +K X as X exponential plus minus I K Y as + + align:start position:0% +K X as X exponential plus minus I K Y as + + + align:start position:0% +K X as X exponential plus minus I K Y as +Y okay where the K X because of the + + align:start position:0% +Y okay where the K X because of the + + + align:start position:0% +Y okay where the K X because of the +boundary condition which we have solved + + align:start position:0% +boundary condition which we have solved + + + align:start position:0% +boundary condition which we have solved +that in the one-dimensional system KX + + align:start position:0% +that in the one-dimensional system KX + + + align:start position:0% +that in the one-dimensional system KX +will be equal to NX pi divided by H + + align:start position:0% +will be equal to NX pi divided by H + + + align:start position:0% +will be equal to NX pi divided by H +right in order to make when you know to + + align:start position:0% +right in order to make when you know to + + + align:start position:0% +right in order to make when you know to +to to match the boundary condition at X + + align:start position:0% +to to match the boundary condition at X + + + align:start position:0% +to to match the boundary condition at X +equal to 0 and X equal to L H and K Y + + align:start position:0% +equal to 0 and X equal to L H and K Y + + + align:start position:0% +equal to 0 and X equal to L H and K Y +will be equal to Y times pi divided by L + + align:start position:0% +will be equal to Y times pi divided by L + + + align:start position:0% +will be equal to Y times pi divided by L +V right that is should be a design to + + align:start position:0% +V right that is should be a design to + + + align:start position:0% +V right that is should be a design to +actually match the boundary condition at + + align:start position:0% +actually match the boundary condition at + + + align:start position:0% +actually match the boundary condition at +y equal to 0 and a y equal to LP okay so + + align:start position:0% +y equal to 0 and a y equal to LP okay so + + + align:start position:0% +y equal to 0 and a y equal to LP okay so +you can see that like what we see before + + align:start position:0% +you can see that like what we see before + + + align:start position:0% +you can see that like what we see before +with one-dimensional system after you + + align:start position:0% +with one-dimensional system after you + + + align:start position:0% +with one-dimensional system after you +introduce the boundary condition is not + + align:start position:0% +introduce the boundary condition is not + + + align:start position:0% +introduce the boundary condition is not +an infinite long system anymore + + align:start position:0% +an infinite long system anymore + + + align:start position:0% +an infinite long system anymore +the + + align:start position:0% +the + + + align:start position:0% +the +out K value which is the wave number in + + align:start position:0% +out K value which is the wave number in + + + align:start position:0% +out K value which is the wave number in +X and the y direction was a boy in this + + align:start position:0% +X and the y direction was a boy in this + + + align:start position:0% +X and the y direction was a boy in this +case it says she also become limited and + + align:start position:0% +case it says she also become limited and + + + align:start position:0% +case it says she also become limited and +only limited number of possible values + + align:start position:0% +only limited number of possible values + + + align:start position:0% +only limited number of possible values +are allowed okay + + align:start position:0% +are allowed okay + + + align:start position:0% +are allowed okay +in this case and X is allowed to be + + align:start position:0% +in this case and X is allowed to be + + + align:start position:0% +in this case and X is allowed to be +equal to 1 to until 4:00 and the my is + + align:start position:0% +equal to 1 to until 4:00 and the my is + + + align:start position:0% +equal to 1 to until 4:00 and the my is +equal to 1 to industry in this in this + + align:start position:0% +equal to 1 to industry in this in this + + + align:start position:0% +equal to 1 to industry in this in this +system we are talking about any question + + align:start position:0% +system we are talking about any question + + + align:start position:0% +system we are talking about any question +so what + + align:start position:0% +so what + + + align:start position:0% +so what +yep + + align:start position:0% + + + + align:start position:0% + +yeah yeah so so that so I was talking + + align:start position:0% +yeah yeah so so that so I was talking + + + align:start position:0% +yeah yeah so so that so I was talking +about when I choose KX and KY in the + + align:start position:0% +about when I choose KX and KY in the + + + align:start position:0% +about when I choose KX and KY in the +infinitely long system because K okay + + align:start position:0% +infinitely long system because K okay + + + align:start position:0% +infinitely long system because K okay +all the possible values of KX and KY + + align:start position:0% +all the possible values of KX and KY + + + align:start position:0% +all the possible values of KX and KY +allowed because I have a impeded long + + align:start position:0% +allowed because I have a impeded long + + + align:start position:0% +allowed because I have a impeded long +system with no boundary condition and in + + align:start position:0% +system with no boundary condition and in + + + align:start position:0% +system with no boundary condition and in +that case okay going back to this + + align:start position:0% +that case okay going back to this + + + align:start position:0% +that case okay going back to this +dispersion relation I have the freedom + + align:start position:0% +dispersion relation I have the freedom + + + align:start position:0% +dispersion relation I have the freedom +to okay so when I increase a little bit + + align:start position:0% +to okay so when I increase a little bit + + + align:start position:0% +to okay so when I increase a little bit +KX I can always decrease a little bit + + align:start position:0% +KX I can always decrease a little bit + + + align:start position:0% +KX I can always decrease a little bit +okay why okay so the question is why + + align:start position:0% +okay why okay so the question is why + + + align:start position:0% +okay why okay so the question is why +that's not the case right for the + + align:start position:0% +that's not the case right for the + + + align:start position:0% +that's not the case right for the +discrete case okay as you can see from + + align:start position:0% +discrete case okay as you can see from + + + align:start position:0% +discrete case okay as you can see from +here after we introduce the boundary + + align:start position:0% +here after we introduce the boundary + + + align:start position:0% +here after we introduce the boundary +condition the four boundary conditions + + align:start position:0% +condition the four boundary conditions + + + align:start position:0% +condition the four boundary conditions +here should be described the boundary at + + align:start position:0% +here should be described the boundary at + + + align:start position:0% +here should be described the boundary at +the four walls okay + + align:start position:0% +the four walls okay + + + align:start position:0% +the four walls okay +and what is going to happen is that you + + align:start position:0% +and what is going to happen is that you + + + align:start position:0% +and what is going to happen is that you +will also see that the loud k x value is + + align:start position:0% +will also see that the loud k x value is + + + align:start position:0% +will also see that the loud k x value is +becoming limited right because if you + + align:start position:0% +becoming limited right because if you + + + align:start position:0% +becoming limited right because if you +you cannot choose arbitrarily choose + + align:start position:0% +you cannot choose arbitrarily choose + + + align:start position:0% +you cannot choose arbitrarily choose +wavelength right if you choose society + + align:start position:0% +wavelength right if you choose society + + + align:start position:0% +wavelength right if you choose society +longer wavelengths like what we have + + align:start position:0% +longer wavelengths like what we have + + + align:start position:0% +longer wavelengths like what we have +been trying to do for the infinite + + align:start position:0% +been trying to do for the infinite + + + align:start position:0% +been trying to do for the infinite +Launceston lot doesn't match the + + align:start position:0% +Launceston lot doesn't match the + + + align:start position:0% +Launceston lot doesn't match the +boundary condition okay therefore you + + align:start position:0% +boundary condition okay therefore you + + + align:start position:0% +boundary condition okay therefore you +don't have this degree of freedom to + + align:start position:0% +don't have this degree of freedom to + + + align:start position:0% +don't have this degree of freedom to +choose you know side the higher side is + + align:start position:0% +choose you know side the higher side is + + + align:start position:0% +choose you know side the higher side is +lower KY when I have when I change the + + align:start position:0% +lower KY when I have when I change the + + + align:start position:0% +lower KY when I have when I change the +KX okay so you can see that the the + + align:start position:0% +KX okay so you can see that the the + + + align:start position:0% +KX okay so you can see that the the +allowed value out is quit therefore the + + align:start position:0% +allowed value out is quit therefore the + + + align:start position:0% +allowed value out is quit therefore the +number of possible combination of KX and + + align:start position:0% +number of possible combination of KX and + + + align:start position:0% +number of possible combination of KX and +KY is also limited and in this case it's + + align:start position:0% +KY is also limited and in this case it's + + + align:start position:0% +KY is also limited and in this case it's +actually very likely to be limited to be + + align:start position:0% +actually very likely to be limited to be + + + align:start position:0% +actually very likely to be limited to be +only four pairs which says you pass + + align:start position:0% +only four pairs which says you pass + + + align:start position:0% +only four pairs which says you pass +minus KX and the first minus KY okay all + + align:start position:0% +minus KX and the first minus KY okay all + + + align:start position:0% +minus KX and the first minus KY okay all +right + + align:start position:0% +right + + + align:start position:0% +right +so thank you for the question okay then + + align:start position:0% +so thank you for the question okay then + + + align:start position:0% +so thank you for the question okay then +once I have those I can do a linear + + align:start position:0% +once I have those I can do a linear + + + align:start position:0% +once I have those I can do a linear +combination of these four possible eigen + + align:start position:0% +combination of these four possible eigen + + + align:start position:0% +combination of these four possible eigen +vectors and also at the same time I will + + align:start position:0% +vectors and also at the same time I will + + + align:start position:0% +vectors and also at the same time I will +try to match the boundary condition + + align:start position:0% +try to match the boundary condition + + + align:start position:0% +try to match the boundary condition +right so if I jump forward basically + + align:start position:0% +right so if I jump forward basically + + + align:start position:0% +right so if I jump forward basically +what you can actually conclude is that + + align:start position:0% +what you can actually conclude is that + + + align:start position:0% +what you can actually conclude is that +sigh and X Y okay so it's with any + + align:start position:0% +sigh and X Y okay so it's with any + + + align:start position:0% +sigh and X Y okay so it's with any +x-value and y-value chosen foot for the + + align:start position:0% +x-value and y-value chosen foot for the + + + align:start position:0% +x-value and y-value chosen foot for the +determination of KX and KY and this is + + align:start position:0% +determination of KX and KY and this is + + + align:start position:0% +determination of KX and KY and this is +actually a function as a function of x + + align:start position:0% +actually a function as a function of x + + + align:start position:0% +actually a function as a function of x +and y know of course also time right + + align:start position:0% +and y know of course also time right + + + align:start position:0% +and y know of course also time right +when I actually also make it oscillate + + align:start position:0% +when I actually also make it oscillate + + + align:start position:0% +when I actually also make it oscillate +as a function of time this will be equal + + align:start position:0% +as a function of time this will be equal + + + align:start position:0% +as a function of time this will be equal +to some arbitrary constant anp2 and X Y + + align:start position:0% +to some arbitrary constant anp2 and X Y + + + align:start position:0% +to some arbitrary constant anp2 and X Y +sine and X PI X T YT pi ll H sine white + + align:start position:0% +sine and X PI X T YT pi ll H sine white + + + align:start position:0% +sine and X PI X T YT pi ll H sine white +I right / LP okay and of course this is + + align:start position:0% +I right / LP okay and of course this is + + + align:start position:0% +I right / LP okay and of course this is +actually you can see that this is a sign + + align:start position:0% +actually you can see that this is a sign + + + align:start position:0% +actually you can see that this is a sign +right it's actually the same as what we + + align:start position:0% +right it's actually the same as what we + + + align:start position:0% +right it's actually the same as what we +have done for the one-dimensional system + + align:start position:0% +have done for the one-dimensional system + + + align:start position:0% +have done for the one-dimensional system +right so if you have two boundary + + align:start position:0% +right so if you have two boundary + + + align:start position:0% +right so if you have two boundary +conditions at the beginning and the end + + align:start position:0% +conditions at the beginning and the end + + + align:start position:0% +conditions at the beginning and the end +therefore the the corresponding no more + + align:start position:0% +therefore the the corresponding no more + + + align:start position:0% +therefore the the corresponding no more +is always a sine function right so + + align:start position:0% +is always a sine function right so + + + align:start position:0% +is always a sine function right so +that's issue what we have learned from + + align:start position:0% +that's issue what we have learned from + + + align:start position:0% +that's issue what we have learned from +from the one-dimensional system and it + + align:start position:0% +from the one-dimensional system and it + + + align:start position:0% +from the one-dimensional system and it +is a so also the case for the + + align:start position:0% +is a so also the case for the + + + align:start position:0% +is a so also the case for the +two-dimensional system and of course we + + align:start position:0% +two-dimensional system and of course we + + + align:start position:0% +two-dimensional system and of course we +don't have don't forget this system this + + align:start position:0% +don't have don't forget this system this + + + align:start position:0% +don't have don't forget this system this +wave function is changing as a function + + align:start position:0% +wave function is changing as a function + + + align:start position:0% +wave function is changing as a function +of time oscillating up and down + + align:start position:0% +of time oscillating up and down + + + align:start position:0% +of time oscillating up and down +harmonically okay therefore we have sine + + align:start position:0% +harmonically okay therefore we have sine + + + align:start position:0% +harmonically okay therefore we have sine +Omega and X Y times T plus beta which is + + align:start position:0% +Omega and X Y times T plus beta which is + + + align:start position:0% +Omega and X Y times T plus beta which is +a face to be determined by initial + + align:start position:0% +a face to be determined by initial + + + align:start position:0% +a face to be determined by initial +conditions okay and you can see that the + + align:start position:0% +conditions okay and you can see that the + + + align:start position:0% +conditions okay and you can see that the +whole + + align:start position:0% +whole + + + align:start position:0% +whole +the whole equation a sign sign is + + align:start position:0% +the whole equation a sign sign is + + + align:start position:0% +the whole equation a sign sign is +multiplied by a sign or megha T plus + + align:start position:0% +multiplied by a sign or megha T plus + + + align:start position:0% +multiplied by a sign or megha T plus +five plus a beta function right so that + + align:start position:0% +five plus a beta function right so that + + + align:start position:0% +five plus a beta function right so that +means the shape is actually going up and + + align:start position:0% +means the shape is actually going up and + + + align:start position:0% +means the shape is actually going up and +down harmonically right so the shape is + + align:start position:0% +down harmonically right so the shape is + + + align:start position:0% +down harmonically right so the shape is +fixed which is sine times sine and the + + align:start position:0% +fixed which is sine times sine and the + + + align:start position:0% +fixed which is sine times sine and the +whole thing is oscillating at the same + + align:start position:0% +whole thing is oscillating at the same + + + align:start position:0% +whole thing is oscillating at the same +frequency at the same phase which is the + + align:start position:0% +frequency at the same phase which is the + + + align:start position:0% +frequency at the same phase which is the +definition of normal more right + + align:start position:0% +definition of normal more right + + + align:start position:0% +definition of normal more right +just a reminder and how do we actually + + align:start position:0% +just a reminder and how do we actually + + + align:start position:0% +just a reminder and how do we actually +imaging what is actually happening that + + align:start position:0% +imaging what is actually happening that + + + align:start position:0% +imaging what is actually happening that +brings me to the demonstration right so + + align:start position:0% +brings me to the demonstration right so + + + align:start position:0% +brings me to the demonstration right so +we can issue the really visualize how + + align:start position:0% +we can issue the really visualize how + + + align:start position:0% +we can issue the really visualize how +this kind of system would look like by a + + align:start position:0% +this kind of system would look like by a + + + align:start position:0% +this kind of system would look like by a +little simulation right so suppose I + + align:start position:0% +little simulation right so suppose I + + + align:start position:0% +little simulation right so suppose I +choose an X and an y equal to one and + + align:start position:0% +choose an X and an y equal to one and + + + align:start position:0% +choose an X and an y equal to one and +see what will happen so this is actually + + align:start position:0% +see what will happen so this is actually + + + align:start position:0% +see what will happen so this is actually +the kind of oscillation you will expect + + align:start position:0% +the kind of oscillation you will expect + + + align:start position:0% +the kind of oscillation you will expect +right so if you choose an exit go to one + + align:start position:0% +right so if you choose an exit go to one + + + align:start position:0% +right so if you choose an exit go to one +and y equal to one then this is a system + + align:start position:0% +and y equal to one then this is a system + + + align:start position:0% +and y equal to one then this is a system +right basically you have sine function + + align:start position:0% +right basically you have sine function + + + align:start position:0% +right basically you have sine function +with no note in x and y direction okay + + align:start position:0% +with no note in x and y direction okay + + + align:start position:0% +with no note in x and y direction okay +therefore if you look at this this this + + align:start position:0% +therefore if you look at this this this + + + align:start position:0% +therefore if you look at this this this +simulation you can see that there will + + align:start position:0% +simulation you can see that there will + + + align:start position:0% +simulation you can see that there will +be no note in the XY plane and and and + + align:start position:0% +be no note in the XY plane and and and + + + align:start position:0% +be no note in the XY plane and and and +all those particles are either going + + align:start position:0% +all those particles are either going + + + align:start position:0% +all those particles are either going +toward you or going away from you right + + align:start position:0% +toward you or going away from you right + + + align:start position:0% +toward you or going away from you right +in the only oscillate in the in the Z + + align:start position:0% +in the only oscillate in the in the Z + + + align:start position:0% +in the only oscillate in the in the Z +Direction okay in this simulation and + + align:start position:0% +Direction okay in this simulation and + + + align:start position:0% +Direction okay in this simulation and +also you can see that now I can increase + + align:start position:0% +also you can see that now I can increase + + + align:start position:0% +also you can see that now I can increase +for example the KX to be so I can + + align:start position:0% +for example the KX to be so I can + + + align:start position:0% +for example the KX to be so I can +increase the KX by setting X to be two + + align:start position:0% +increase the KX by setting X to be two + + + align:start position:0% +increase the KX by setting X to be two +and see what happen so what is going to + + align:start position:0% +and see what happen so what is going to + + + align:start position:0% +and see what happen so what is going to +happen is that if I have higher K X in + + align:start position:0% +happen is that if I have higher K X in + + + align:start position:0% +happen is that if I have higher K X in +the X direction so the next possible + + align:start position:0% +the X direction so the next possible + + + align:start position:0% +the X direction so the next possible +normal mode is that you have + + align:start position:0% +normal mode is that you have + + + align:start position:0% +normal mode is that you have +as for sine wave right in the X + + align:start position:0% +as for sine wave right in the X + + + align:start position:0% +as for sine wave right in the X +direction then what you are going to see + + align:start position:0% +direction then what you are going to see + + + align:start position:0% +direction then what you are going to see +is that you are going to see two + + align:start position:0% +is that you are going to see two + + + align:start position:0% +is that you are going to see two +components in this in this demonstration + + align:start position:0% +components in this in this demonstration + + + align:start position:0% +components in this in this demonstration +and one one is one part of the system + + align:start position:0% +and one one is one part of the system + + + align:start position:0% +and one one is one part of the system +says you moving to where you while the + + align:start position:0% +says you moving to where you while the + + + align:start position:0% +says you moving to where you while the +other part they all have a half part of + + align:start position:0% +other part they all have a half part of + + + align:start position:0% +other part they all have a half part of +the season is actually moving away from + + align:start position:0% +the season is actually moving away from + + + align:start position:0% +the season is actually moving away from +you and you can actually see the note or + + align:start position:0% +you and you can actually see the note or + + + align:start position:0% +you and you can actually see the note or +know the line in this case because we + + align:start position:0% +know the line in this case because we + + + align:start position:0% +know the line in this case because we +are talking about a two dimensional + + align:start position:0% +are talking about a two dimensional + + + align:start position:0% +are talking about a two dimensional +system in the middle of the distribution + + align:start position:0% +system in the middle of the distribution + + + align:start position:0% +system in the middle of the distribution +okay of course we can actually go waste + + align:start position:0% +okay of course we can actually go waste + + + align:start position:0% +okay of course we can actually go waste +go crazy right I can set this to really + + align:start position:0% +go crazy right I can set this to really + + + align:start position:0% +go crazy right I can set this to really +high value so in this case like the + + align:start position:0% +high value so in this case like the + + + align:start position:0% +high value so in this case like the +highest value I can set this three and + + align:start position:0% +highest value I can set this three and + + + align:start position:0% +highest value I can set this three and +the four okay and see what happened and + + align:start position:0% +the four okay and see what happened and + + + align:start position:0% +the four okay and see what happened and +this is actually a beautiful shape which + + align:start position:0% +this is actually a beautiful shape which + + + align:start position:0% +this is actually a beautiful shape which +is actually complicated but + + align:start position:0% +is actually complicated but + + + align:start position:0% +is actually complicated but +understandable which we can as we see + + align:start position:0% +understandable which we can as we see + + + align:start position:0% +understandable which we can as we see +from funding in this demonstration and + + align:start position:0% +from funding in this demonstration and + + + align:start position:0% +from funding in this demonstration and +all those all those little particles + + align:start position:0% +all those all those little particles + + + align:start position:0% +all those all those little particles +indices and other thing up and down at + + align:start position:0% +indices and other thing up and down at + + + align:start position:0% +indices and other thing up and down at +the cent and your frequency and also in + + align:start position:0% +the cent and your frequency and also in + + + align:start position:0% +the cent and your frequency and also in +the same face any questions okay so now + + align:start position:0% +the same face any questions okay so now + + + align:start position:0% +the same face any questions okay so now +we have done the discrete a case right + + align:start position:0% +we have done the discrete a case right + + + align:start position:0% +we have done the discrete a case right +and of course we can also go to the + + align:start position:0% +and of course we can also go to the + + + align:start position:0% +and of course we can also go to the +continuous case right so if we go to a + + align:start position:0% +continuous case right so if we go to a + + + align:start position:0% +continuous case right so if we go to a +continuous limit okay now I can assume + + align:start position:0% +continuous limit okay now I can assume + + + align:start position:0% +continuous limit okay now I can assume +that there is a symmetry between + + align:start position:0% +that there is a symmetry between + + + align:start position:0% +that there is a symmetry between +horizontal direction and the vertical + + align:start position:0% +horizontal direction and the vertical + + + align:start position:0% +horizontal direction and the vertical +direction I assume that th is equal to + + align:start position:0% +direction I assume that th is equal to + + + align:start position:0% +direction I assume that th is equal to +PV is equal to T okay + + align:start position:0% +PV is equal to T okay + + + align:start position:0% +PV is equal to T okay +and also I assume that the time scale in + + align:start position:0% +and also I assume that the time scale in + + + align:start position:0% +and also I assume that the time scale in +the X direction and the y directions are + + align:start position:0% +the X direction and the y directions are + + + align:start position:0% +the X direction and the y directions are +equal and the length scale is a-okay in + + align:start position:0% +equal and the length scale is a-okay in + + + align:start position:0% +equal and the length scale is a-okay in +order to make the whole system + + align:start position:0% +order to make the whole system + + + align:start position:0% +order to make the whole system +continuous okay I need to increase the + + align:start position:0% +continuous okay I need to increase the + + + align:start position:0% +continuous okay I need to increase the +number of objects in this system at the + + align:start position:0% +number of objects in this system at the + + + align:start position:0% +number of objects in this system at the +same time I also need to decrease + + align:start position:0% +same time I also need to decrease + + + align:start position:0% +same time I also need to decrease +the distance between all those objects + + align:start position:0% +the distance between all those objects + + + align:start position:0% +the distance between all those objects +right so therefore I need to have this + + align:start position:0% +right so therefore I need to have this + + + align:start position:0% +right so therefore I need to have this +lens skill goes to zero and what is + + align:start position:0% +lens skill goes to zero and what is + + + align:start position:0% +lens skill goes to zero and what is +going to happen is that if I rewrite my + + align:start position:0% +going to happen is that if I rewrite my + + + align:start position:0% +going to happen is that if I rewrite my +Omega okay which is dispersion which is + + align:start position:0% +Omega okay which is dispersion which is + + + align:start position:0% +Omega okay which is dispersion which is +a dispersion relation what I'm going to + + align:start position:0% +a dispersion relation what I'm going to + + + align:start position:0% +a dispersion relation what I'm going to +get is 40 divided by n times a KX + + align:start position:0% +get is 40 divided by n times a KX + + + align:start position:0% +get is 40 divided by n times a KX +squared a squared divided by 4 plus 40 + + align:start position:0% +squared a squared divided by 4 plus 40 + + + align:start position:0% +squared a squared divided by 4 plus 40 +over MA okay y squared a squared over 4 + + align:start position:0% +over MA okay y squared a squared over 4 + + + align:start position:0% +over MA okay y squared a squared over 4 +all right this is actually because I'm + + align:start position:0% +all right this is actually because I'm + + + align:start position:0% +all right this is actually because I'm +taking a H and V to be equal to a and + + align:start position:0% +taking a H and V to be equal to a and + + + align:start position:0% +taking a H and V to be equal to a and +also having that to be very very small + + align:start position:0% +also having that to be very very small + + + align:start position:0% +also having that to be very very small +value therefore sine theta is roughly 2 + + align:start position:0% +value therefore sine theta is roughly 2 + + + align:start position:0% +value therefore sine theta is roughly 2 +theta right therefore I can immediately + + align:start position:0% +theta right therefore I can immediately + + + align:start position:0% +theta right therefore I can immediately +write down this expression okay and this + + align:start position:0% +write down this expression okay and this + + + align:start position:0% +write down this expression okay and this +will be equal to PA D by D PI + KX + + align:start position:0% +will be equal to PA D by D PI + KX + + + align:start position:0% +will be equal to PA D by D PI + KX +square plus KY school okay so we are + + align:start position:0% +square plus KY school okay so we are + + + align:start position:0% +square plus KY school okay so we are +facing exactly the same situation when I + + align:start position:0% +facing exactly the same situation when I + + + align:start position:0% +facing exactly the same situation when I +decrease a I am going to add more + + align:start position:0% +decrease a I am going to add more + + + align:start position:0% +decrease a I am going to add more +objects into this system right but I + + align:start position:0% +objects into this system right but I + + + align:start position:0% +objects into this system right but I +don't want to have an infinitely large + + align:start position:0% +don't want to have an infinitely large + + + align:start position:0% +don't want to have an infinitely large +mass right therefore I also need to + + align:start position:0% +mass right therefore I also need to + + + align:start position:0% +mass right therefore I also need to +actually fix the ratio of M and a ok so + + align:start position:0% +actually fix the ratio of M and a ok so + + + align:start position:0% +actually fix the ratio of M and a ok so +that actually when I actually increase + + align:start position:0% +that actually when I actually increase + + + align:start position:0% +that actually when I actually increase +number of object I don't actually make + + align:start position:0% +number of object I don't actually make + + + align:start position:0% +number of object I don't actually make +the total mass as it goes to infinity + + align:start position:0% +the total mass as it goes to infinity + + + align:start position:0% +the total mass as it goes to infinity +okay so what I could do is that okay I + + align:start position:0% +okay so what I could do is that okay I + + + align:start position:0% +okay so what I could do is that okay I +can define Rho s put usage with the + + align:start position:0% +can define Rho s put usage with the + + + align:start position:0% +can define Rho s put usage with the +surface mass density okay so the surface + + align:start position:0% +surface mass density okay so the surface + + + align:start position:0% +surface mass density okay so the surface +mass density is defined as n divided by + + align:start position:0% +mass density is defined as n divided by + + + align:start position:0% +mass density is defined as n divided by +a square and I can also define a surface + + align:start position:0% +a square and I can also define a surface + + + align:start position:0% +a square and I can also define a surface +tension + + align:start position:0% +tension + + + align:start position:0% +tension +okay surface tension T s will be equal + + align:start position:0% +okay surface tension T s will be equal + + + align:start position:0% +okay surface tension T s will be equal +to T + + align:start position:0% +to T + + + align:start position:0% +to T +a-okay and in this case okay basically I + + align:start position:0% +a-okay and in this case okay basically I + + + align:start position:0% +a-okay and in this case okay basically I +will be able to control so that when I + + align:start position:0% +will be able to control so that when I + + + align:start position:0% +will be able to control so that when I +increase the number of objects + + align:start position:0% +increase the number of objects + + + align:start position:0% +increase the number of objects +masculine go to infinity and I have a + + align:start position:0% +masculine go to infinity and I have a + + + align:start position:0% +masculine go to infinity and I have a +constant surface tension and constant + + align:start position:0% +constant surface tension and constant + + + align:start position:0% +constant surface tension and constant +surface mass density okay if I have + + align:start position:0% +surface mass density okay if I have + + + align:start position:0% +surface mass density okay if I have +defined these two quantity then this + + align:start position:0% +defined these two quantity then this + + + align:start position:0% +defined these two quantity then this +will become he s divided by Rho s KX + + align:start position:0% +will become he s divided by Rho s KX + + + align:start position:0% +will become he s divided by Rho s KX +square plus KY square and this will be + + align:start position:0% +square plus KY square and this will be + + + align:start position:0% +square plus KY square and this will be +equal to PS divided by Rho s K vector + + align:start position:0% +equal to PS divided by Rho s K vector + + + align:start position:0% +equal to PS divided by Rho s K vector +squared okay and this K vector is a + + align:start position:0% +squared okay and this K vector is a + + + align:start position:0% +squared okay and this K vector is a +two-dimensional vector so we are + + align:start position:0% +two-dimensional vector so we are + + + align:start position:0% +two-dimensional vector so we are +actually almost there to make it + + align:start position:0% +actually almost there to make it + + + align:start position:0% +actually almost there to make it +continuous so now I can make a goes to a + + align:start position:0% +continuous so now I can make a goes to a + + + align:start position:0% +continuous so now I can make a goes to a +very small value with fixed PS and a Rho + + align:start position:0% +very small value with fixed PS and a Rho + + + align:start position:0% +very small value with fixed PS and a Rho +s very similar to what we have learned + + align:start position:0% +s very similar to what we have learned + + + align:start position:0% +s very similar to what we have learned +from the one-dimensional case basically + + align:start position:0% +from the one-dimensional case basically + + + align:start position:0% +from the one-dimensional case basically +what we actually found a lot of time in + + align:start position:0% +what we actually found a lot of time in + + + align:start position:0% +what we actually found a lot of time in +a one-dimensional case is that n minus 1 + + align:start position:0% +a one-dimensional case is that n minus 1 + + + align:start position:0% +a one-dimensional case is that n minus 1 +K matrix become minus T over Rho L by 2 + + align:start position:0% +K matrix become minus T over Rho L by 2 + + + align:start position:0% +K matrix become minus T over Rho L by 2 +square by dou X square in a + + align:start position:0% +square by dou X square in a + + + align:start position:0% +square by dou X square in a +one-dimensional case okay and in the two + + align:start position:0% +one-dimensional case okay and in the two + + + align:start position:0% +one-dimensional case okay and in the two +dimensional case without walking through + + align:start position:0% +dimensional case without walking through + + + align:start position:0% +dimensional case without walking through +all the detail of mass basically what we + + align:start position:0% +all the detail of mass basically what we + + + align:start position:0% +all the detail of mass basically what we +are going to get this partial square + + align:start position:0% +are going to get this partial square + + + align:start position:0% +are going to get this partial square +partial T squared side X Y it's in + + align:start position:0% +partial T squared side X Y it's in + + + align:start position:0% +partial T squared side X Y it's in +tertiary or functional X&Y and the time + + align:start position:0% +tertiary or functional X&Y and the time + + + align:start position:0% +tertiary or functional X&Y and the time +right because this is a 3 a 2 + + align:start position:0% +right because this is a 3 a 2 + + + align:start position:0% +right because this is a 3 a 2 +dimensional system and this will be + + align:start position:0% +dimensional system and this will be + + + align:start position:0% +dimensional system and this will be +equal to v square R square plus X square + + align:start position:0% +equal to v square R square plus X square + + + align:start position:0% +equal to v square R square plus X square +plus R square by 2 y spoon side X Y + + align:start position:0% +plus R square by 2 y spoon side X Y + + + align:start position:0% +plus R square by 2 y spoon side X Y +very similar to what we have done for + + align:start position:0% +very similar to what we have done for + + + align:start position:0% +very similar to what we have done for +the wine dimensional system and of + + align:start position:0% +the wine dimensional system and of + + + align:start position:0% +the wine dimensional system and of +course I can I can actually define this + + align:start position:0% +course I can I can actually define this + + + align:start position:0% +course I can I can actually define this +estelle task where right and basically + + align:start position:0% +estelle task where right and basically + + + align:start position:0% +estelle task where right and basically +what you are going to get is v square L + + align:start position:0% +what you are going to get is v square L + + + align:start position:0% +what you are going to get is v square L +square sy X Y okay so basically we can + + align:start position:0% +square sy X Y okay so basically we can + + + align:start position:0% +square sy X Y okay so basically we can +see this wave equation but this wave + + align:start position:0% +see this wave equation but this wave + + + align:start position:0% +see this wave equation but this wave +equation is now a two dimensional wave + + align:start position:0% +equation is now a two dimensional wave + + + align:start position:0% +equation is now a two dimensional wave +equation okay and we can also figure out + + align:start position:0% +equation okay and we can also figure out + + + align:start position:0% +equation okay and we can also figure out +well be the V value right so what would + + align:start position:0% +well be the V value right so what would + + + align:start position:0% +well be the V value right so what would +be the velocity the velocity which we + + align:start position:0% +be the velocity the velocity which we + + + align:start position:0% +be the velocity the velocity which we +will go to be square root of P s over R + + align:start position:0% +will go to be square root of P s over R + + + align:start position:0% +will go to be square root of P s over R +or s okay this is actually very similar + + align:start position:0% +or s okay this is actually very similar + + + align:start position:0% +or s okay this is actually very similar +to what we have done for the continuous + + align:start position:0% +to what we have done for the continuous + + + align:start position:0% +to what we have done for the continuous +case and in this case what we pressed + + align:start position:0% +case and in this case what we pressed + + + align:start position:0% +case and in this case what we pressed +here over Rho L is TS over Rho s okay + + align:start position:0% +here over Rho L is TS over Rho s okay + + + align:start position:0% +here over Rho L is TS over Rho s okay +therefore what we actually see is that + + align:start position:0% +therefore what we actually see is that + + + align:start position:0% +therefore what we actually see is that +if I increase the surface tension then + + align:start position:0% +if I increase the surface tension then + + + align:start position:0% +if I increase the surface tension then +the velocity will increase if I decrease + + align:start position:0% +the velocity will increase if I decrease + + + align:start position:0% +the velocity will increase if I decrease +the mass per unit area Rho s then I will + + align:start position:0% +the mass per unit area Rho s then I will + + + align:start position:0% +the mass per unit area Rho s then I will +be able to have a much faster troubling + + align:start position:0% +be able to have a much faster troubling + + + align:start position:0% +be able to have a much faster troubling +way from these kind of media okay + + align:start position:0% +way from these kind of media okay + + + align:start position:0% +way from these kind of media okay +and what we can actually immediately + + align:start position:0% +and what we can actually immediately + + + align:start position:0% +and what we can actually immediately +also write down is that the size will be + + align:start position:0% +also write down is that the size will be + + + align:start position:0% +also write down is that the size will be +equal proportional to a sine KX times X + + align:start position:0% +equal proportional to a sine KX times X + + + align:start position:0% +equal proportional to a sine KX times X +sine okay Y times y in sine Omega T plus + + align:start position:0% +sine okay Y times y in sine Omega T plus + + + align:start position:0% +sine okay Y times y in sine Omega T plus +five where Omega is they should be + + align:start position:0% +five where Omega is they should be + + + align:start position:0% +five where Omega is they should be +calculated from the input KX and KY for + + align:start position:0% +calculated from the input KX and KY for + + + align:start position:0% +calculated from the input KX and KY for +this for this standing wave solution + + align:start position:0% +this for this standing wave solution + + + align:start position:0% +this for this standing wave solution +okay and very similarly okay I can also + + align:start position:0% +okay and very similarly okay I can also + + + align:start position:0% +okay and very similarly okay I can also +argue that in the three-dimensional case + + align:start position:0% +argue that in the three-dimensional case + + + align:start position:0% +argue that in the three-dimensional case +I can actually follow exactly the same + + align:start position:0% +I can actually follow exactly the same + + + align:start position:0% +I can actually follow exactly the same +argument basically in the + + align:start position:0% +argument basically in the + + + align:start position:0% +argument basically in the +three-dimensional case as well we + + align:start position:0% +three-dimensional case as well we + + + align:start position:0% +three-dimensional case as well we +already see in the electromagnetic wave + + align:start position:0% +already see in the electromagnetic wave + + + align:start position:0% +already see in the electromagnetic wave +it is + + align:start position:0% +it is + + + align:start position:0% +it is +question the street I mentioned no wave + + align:start position:0% +question the street I mentioned no wave + + + align:start position:0% +question the street I mentioned no wave +equation can be written as partial + + align:start position:0% +equation can be written as partial + + + align:start position:0% +equation can be written as partial +square partial t square side is a + + align:start position:0% +square partial t square side is a + + + align:start position:0% +square partial t square side is a +function of x y and z and t and this + + align:start position:0% +function of x y and z and t and this + + + align:start position:0% +function of x y and z and t and this +will be equal to we square R square + + align:start position:0% +will be equal to we square R square + + + align:start position:0% +will be equal to we square R square +partial x squared plus partial square + + align:start position:0% +partial x squared plus partial square + + + align:start position:0% +partial x squared plus partial square +partial Y square partial square v square + + align:start position:0% +partial Y square partial square v square + + + align:start position:0% +partial Y square partial square v square +sy is a function X Y Z and the questions + + align:start position:0% +sy is a function X Y Z and the questions + + + align:start position:0% +sy is a function X Y Z and the questions +so far + + align:start position:0% +so far + + + align:start position:0% +so far +nope okay so everything is Chris called + + align:start position:0% +nope okay so everything is Chris called + + + align:start position:0% +nope okay so everything is Chris called +the good ear right okay so so this is + + align:start position:0% +the good ear right okay so so this is + + + align:start position:0% +the good ear right okay so so this is +actually the the animation which I show + + align:start position:0% +actually the the animation which I show + + + align:start position:0% +actually the the animation which I show +you before already so this is actually + + align:start position:0% +you before already so this is actually + + + align:start position:0% +you before already so this is actually +the toot I mean to toot I mentioned no + + align:start position:0% +the toot I mean to toot I mentioned no + + + align:start position:0% +the toot I mean to toot I mentioned no +vibration of membranes okay so basically + + align:start position:0% +vibration of membranes okay so basically + + + align:start position:0% +vibration of membranes okay so basically +the first one is actually well I have + + align:start position:0% +the first one is actually well I have + + + align:start position:0% +the first one is actually well I have +shown you when I choose various small K + + align:start position:0% +shown you when I choose various small K + + + align:start position:0% +shown you when I choose various small K +value okay which way should be only make + + align:start position:0% +value okay which way should be only make + + + align:start position:0% +value okay which way should be only make +a stop of the sign and which match the + + align:start position:0% +a stop of the sign and which match the + + + align:start position:0% +a stop of the sign and which match the +boundary country condition then + + align:start position:0% +boundary country condition then + + + align:start position:0% +boundary country condition then +basically you see that their oscillation + + align:start position:0% +basically you see that their oscillation + + + align:start position:0% +basically you see that their oscillation +which you have the middle part which is + + align:start position:0% +which you have the middle part which is + + + align:start position:0% +which you have the middle part which is +either going toward you or going away + + align:start position:0% +either going toward you or going away + + + align:start position:0% +either going toward you or going away +from you in this continuous system so + + align:start position:0% +from you in this continuous system so + + + align:start position:0% +from you in this continuous system so +basically the solution is actually + + align:start position:0% +basically the solution is actually + + + align:start position:0% +basically the solution is actually +romantic about the the same as what we + + align:start position:0% +romantic about the the same as what we + + + align:start position:0% +romantic about the the same as what we +have seen in the discrete sister okay + + align:start position:0% +have seen in the discrete sister okay + + + align:start position:0% +have seen in the discrete sister okay +that's issue what I want to say and also + + align:start position:0% +that's issue what I want to say and also + + + align:start position:0% +that's issue what I want to say and also +of course you can increase the the K + + align:start position:0% +of course you can increase the the K + + + align:start position:0% +of course you can increase the the K +value and so that you go to the higher + + align:start position:0% +value and so that you go to the higher + + + align:start position:0% +value and so that you go to the higher +frequency normal more and you can see + + align:start position:0% +frequency normal more and you can see + + + align:start position:0% +frequency normal more and you can see +that if you have more and more nodal + + align:start position:0% +that if you have more and more nodal + + + align:start position:0% +that if you have more and more nodal +lines okay which is actually the lines + + align:start position:0% +lines okay which is actually the lines + + + align:start position:0% +lines okay which is actually the lines +describing the the the lines which we + + align:start position:0% +describing the the the lines which we + + + align:start position:0% +describing the the the lines which we +actually have no oscillation okay at all + + align:start position:0% +actually have no oscillation okay at all + + + align:start position:0% +actually have no oscillation okay at all +on the surface for example in this case + + align:start position:0% +on the surface for example in this case + + + align:start position:0% +on the surface for example in this case +the nodal line is actually passing + + align:start position:0% +the nodal line is actually passing + + + align:start position:0% +the nodal line is actually passing +through the middle of this figure right + + align:start position:0% +through the middle of this figure right + + + align:start position:0% +through the middle of this figure right +because all those little mass although + + align:start position:0% +because all those little mass although + + + align:start position:0% +because all those little mass although +all the other particles are vibrating + + align:start position:0% +all the other particles are vibrating + + + align:start position:0% +all the other particles are vibrating +like crazy but + + align:start position:0% +like crazy but + + + align:start position:0% +like crazy but +the all the particles on this line the + + align:start position:0% +the all the particles on this line the + + + align:start position:0% +the all the particles on this line the +nodal line as you not at all moving + + align:start position:0% +nodal line as you not at all moving + + + align:start position:0% +nodal line as you not at all moving +because that's actually actually at the + + align:start position:0% +because that's actually actually at the + + + align:start position:0% +because that's actually actually at the +disposition which is actually having one + + align:start position:0% +disposition which is actually having one + + + align:start position:0% +disposition which is actually having one +of the sine function equal to zero + + align:start position:0% +of the sine function equal to zero + + + align:start position:0% +of the sine function equal to zero +therefore no matter what you do as a + + align:start position:0% +therefore no matter what you do as a + + + align:start position:0% +therefore no matter what you do as a +bunch of time how you evolve this system + + align:start position:0% +bunch of time how you evolve this system + + + align:start position:0% +bunch of time how you evolve this system +or those particle at a line who will not + + align:start position:0% +or those particle at a line who will not + + + align:start position:0% +or those particle at a line who will not +move at all okay and this was actually + + align:start position:0% +move at all okay and this was actually + + + align:start position:0% +move at all okay and this was actually +demonstrated from this demo here + + align:start position:0% +demonstrated from this demo here + + + align:start position:0% +demonstrated from this demo here +especially cottony figures right so you + + align:start position:0% +especially cottony figures right so you + + + align:start position:0% +especially cottony figures right so you +can see that in a two dimensional case + + align:start position:0% +can see that in a two dimensional case + + + align:start position:0% +can see that in a two dimensional case +the figures can looks very complicated + + align:start position:0% +the figures can looks very complicated + + + align:start position:0% +the figures can looks very complicated +so basically what is actually showing + + align:start position:0% +so basically what is actually showing + + + align:start position:0% +so basically what is actually showing +here is that you have a square plate and + + align:start position:0% +here is that you have a square plate and + + + align:start position:0% +here is that you have a square plate and +it's attached to vibrator and basically + + align:start position:0% +it's attached to vibrator and basically + + + align:start position:0% +it's attached to vibrator and basically +this vibrator can be control I can + + align:start position:0% +this vibrator can be control I can + + + align:start position:0% +this vibrator can be control I can +change the frequency of the vibration + + align:start position:0% +change the frequency of the vibration + + + align:start position:0% +change the frequency of the vibration +okay when when I reach resonance which + + align:start position:0% +okay when when I reach resonance which + + + align:start position:0% +okay when when I reach resonance which +excite one of the normal okay then this + + align:start position:0% +excite one of the normal okay then this + + + align:start position:0% +excite one of the normal okay then this +this plate will be oscillating in a + + align:start position:0% +this plate will be oscillating in a + + + align:start position:0% +this plate will be oscillating in a +specific pattern and though and those + + align:start position:0% +specific pattern and though and those + + + align:start position:0% +specific pattern and though and those +lines are actually showing you that the + + align:start position:0% +lines are actually showing you that the + + + align:start position:0% +lines are actually showing you that the +press which you have no oscillation at + + align:start position:0% +press which you have no oscillation at + + + align:start position:0% +press which you have no oscillation at +all as a function of time right because + + align:start position:0% +all as a function of time right because + + + align:start position:0% +all as a function of time right because +if I to example now turn on this demo + + align:start position:0% +if I to example now turn on this demo + + + align:start position:0% +if I to example now turn on this demo +again you can see that if I turn on this + + align:start position:0% +again you can see that if I turn on this + + + align:start position:0% +again you can see that if I turn on this +demo + + align:start position:0% + + + + align:start position:0% + +you can see that Lois always stand on + + align:start position:0% +you can see that Lois always stand on + + + align:start position:0% +you can see that Lois always stand on +the place of vibrating because now i + + align:start position:0% +the place of vibrating because now i + + + align:start position:0% +the place of vibrating because now i +isolated the disparate when upfront by + + align:start position:0% +isolated the disparate when upfront by + + + align:start position:0% +isolated the disparate when upfront by +the by the vibration generator at the + + align:start position:0% +the by the vibration generator at the + + + align:start position:0% +the by the vibration generator at the +button by the motor at the button and if + + align:start position:0% +button by the motor at the button and if + + + align:start position:0% +button by the motor at the button and if +I change the oscillation frequency so + + align:start position:0% +I change the oscillation frequency so + + + align:start position:0% +I change the oscillation frequency so +you can see that his frequency to the + + align:start position:0% +you can see that his frequency to the + + + align:start position:0% +you can see that his frequency to the +match with one of the normal frequency + + align:start position:0% +match with one of the normal frequency + + + align:start position:0% +match with one of the normal frequency +therefore they were not a lot of + + align:start position:0% +therefore they were not a lot of + + + align:start position:0% +therefore they were not a lot of +activity but if I now change the MP to + + align:start position:0% +activity but if I now change the MP to + + + align:start position:0% +activity but if I now change the MP to +I'm sorry I change the frequency so that + + align:start position:0% +I'm sorry I change the frequency so that + + + align:start position:0% +I'm sorry I change the frequency so that +in match with one of the oscillation + + align:start position:0% +in match with one of the oscillation + + + align:start position:0% +in match with one of the oscillation +frequency for the one of the normal mode + + align:start position:0% +frequency for the one of the normal mode + + + align:start position:0% +frequency for the one of the normal mode +of this system you can see the heart + + align:start position:0% +of this system you can see the heart + + + align:start position:0% +of this system you can see the heart +some really cryptic pattern is formed + + align:start position:0% +some really cryptic pattern is formed + + + align:start position:0% +some really cryptic pattern is formed +right you can see that mood you have + + align:start position:0% +right you can see that mood you have + + + align:start position:0% +right you can see that mood you have +very complicated pattern and if I put my + + align:start position:0% +very complicated pattern and if I put my + + + align:start position:0% +very complicated pattern and if I put my +finger in one of the line here + + align:start position:0% +finger in one of the line here + + + align:start position:0% +finger in one of the line here +I don't feel the vibration but on the + + align:start position:0% +I don't feel the vibration but on the + + + align:start position:0% +I don't feel the vibration but on the +other hand if I put my finger here I can + + align:start position:0% +other hand if I put my finger here I can + + + align:start position:0% +other hand if I put my finger here I can +actually feel that this lot of vibration + + align:start position:0% +actually feel that this lot of vibration + + + align:start position:0% +actually feel that this lot of vibration +at a point I can always change the + + align:start position:0% +at a point I can always change the + + + align:start position:0% +at a point I can always change the +frequency and see what will happen and + + align:start position:0% +frequency and see what will happen and + + + align:start position:0% +frequency and see what will happen and +you can see that now I increase the + + align:start position:0% +you can see that now I increase the + + + align:start position:0% +you can see that now I increase the +frequency and now I actually trying to + + align:start position:0% +frequency and now I actually trying to + + + align:start position:0% +frequency and now I actually trying to +excite another mode + + align:start position:0% +excite another mode + + + align:start position:0% +excite another mode +now I need some more sand + + align:start position:0% + + + + align:start position:0% + +you can see that I rent on these Stroh + + align:start position:0% +you can see that I rent on these Stroh + + + align:start position:0% +you can see that I rent on these Stroh +sent on this plate and you can see that + + align:start position:0% +sent on this plate and you can see that + + + align:start position:0% +sent on this plate and you can see that +those Center that she pans around until + + align:start position:0% +those Center that she pans around until + + + align:start position:0% +those Center that she pans around until +is sit until it sees the nodal line + + align:start position:0% +is sit until it sees the nodal line + + + align:start position:0% +is sit until it sees the nodal line +which no vibration actually happened + + align:start position:0% +which no vibration actually happened + + + align:start position:0% +which no vibration actually happened +okay so that's go back to so one of the + + align:start position:0% +okay so that's go back to so one of the + + + align:start position:0% +okay so that's go back to so one of the +lower frequency mode which will show you + + align:start position:0% +lower frequency mode which will show you + + + align:start position:0% +lower frequency mode which will show you +before + + align:start position:0% + + + + align:start position:0% + +now the question is okay you can see + + align:start position:0% +now the question is okay you can see + + + align:start position:0% +now the question is okay you can see +this complicated pattern almost look + + align:start position:0% +this complicated pattern almost look + + + align:start position:0% +this complicated pattern almost look +ridiculous okay + + align:start position:0% +ridiculous okay + + + align:start position:0% +ridiculous okay +can we actually reproduce this pattern + + align:start position:0% +can we actually reproduce this pattern + + + align:start position:0% +can we actually reproduce this pattern +by our calculation right okay so we have + + align:start position:0% +by our calculation right okay so we have + + + align:start position:0% +by our calculation right okay so we have +seen that okay I can conclude that the + + align:start position:0% +seen that okay I can conclude that the + + + align:start position:0% +seen that okay I can conclude that the +the normal mode will looks like this + + align:start position:0% +the normal mode will looks like this + + + align:start position:0% +the normal mode will looks like this +right so therefore I must be able to + + align:start position:0% +right so therefore I must be able to + + + align:start position:0% +right so therefore I must be able to +explain all those pattern which is + + align:start position:0% +explain all those pattern which is + + + align:start position:0% +explain all those pattern which is +actually shown and not figure in this + + align:start position:0% +actually shown and not figure in this + + + align:start position:0% +actually shown and not figure in this +experiment right so that's actually what + + align:start position:0% +experiment right so that's actually what + + + align:start position:0% +experiment right so that's actually what +I'm going to do to give you a try + + align:start position:0% + + + + align:start position:0% + +so so this is actually a detour and + + align:start position:0% +so so this is actually a detour and + + + align:start position:0% +so so this is actually a detour and +demonstration which I actually wrote so + + align:start position:0% +demonstration which I actually wrote so + + + align:start position:0% +demonstration which I actually wrote so +this demonstration actually have the + + align:start position:0% +this demonstration actually have the + + + align:start position:0% +this demonstration actually have the +solution to this two-dimensional problem + + align:start position:0% +solution to this two-dimensional problem + + + align:start position:0% +solution to this two-dimensional problem +and also the boundary condition is that + + align:start position:0% +and also the boundary condition is that + + + align:start position:0% +and also the boundary condition is that +all say the condition which I actually + + align:start position:0% +all say the condition which I actually + + + align:start position:0% +all say the condition which I actually +comes from my solution is that I'd + + align:start position:0% +comes from my solution is that I'd + + + align:start position:0% +comes from my solution is that I'd +require the center of the plate to be + + align:start position:0% +require the center of the plate to be + + + align:start position:0% +require the center of the plate to be +driven right so because that's actually + + align:start position:0% +driven right so because that's actually + + + align:start position:0% +driven right so because that's actually +where I start to vibrate this plate and + + align:start position:0% +where I start to vibrate this plate and + + + align:start position:0% +where I start to vibrate this plate and +I Drive this plate up and down and see + + align:start position:0% +I Drive this plate up and down and see + + + align:start position:0% +I Drive this plate up and down and see +what is going to happen okay so from + + align:start position:0% +what is going to happen okay so from + + + align:start position:0% +what is going to happen okay so from +this and a digital calculation you can + + align:start position:0% +this and a digital calculation you can + + + align:start position:0% +this and a digital calculation you can +see that you expect a circle okay in the + + align:start position:0% +see that you expect a circle okay in the + + + align:start position:0% +see that you expect a circle okay in the +middle and also four lines in which we + + align:start position:0% +middle and also four lines in which we + + + align:start position:0% +middle and also four lines in which we +should cover this circle and also there + + align:start position:0% +should cover this circle and also there + + + align:start position:0% +should cover this circle and also there +are some strange structure at the edge + + align:start position:0% +are some strange structure at the edge + + + align:start position:0% +are some strange structure at the edge +of the of the plate and you can actually + + align:start position:0% +of the of the plate and you can actually + + + align:start position:0% +of the of the plate and you can actually +compare this calculation to this result + + align:start position:0% +compare this calculation to this result + + + align:start position:0% +compare this calculation to this result +it doesn't really match perfectly right + + align:start position:0% +it doesn't really match perfectly right + + + align:start position:0% +it doesn't really match perfectly right +so you can see that there's an + + align:start position:0% +so you can see that there's an + + + align:start position:0% +so you can see that there's an +imperfection but you choose you get a + + align:start position:0% +imperfection but you choose you get a + + + align:start position:0% +imperfection but you choose you get a +ring in the in the middle and you to see + + align:start position:0% +ring in the in the middle and you to see + + + align:start position:0% +ring in the in the middle and you to see +this 1 2 3 4 5 6 7 8 8 lines produce in + + align:start position:0% +this 1 2 3 4 5 6 7 8 8 lines produce in + + + align:start position:0% +this 1 2 3 4 5 6 7 8 8 lines produce in +this experiment so this is this + + align:start position:0% +this experiment so this is this + + + align:start position:0% +this experiment so this is this +experiment is not perfect because they + + align:start position:0% +experiment is not perfect because they + + + align:start position:0% +experiment is not perfect because they +are like as you know stiffness of this + + align:start position:0% +are like as you know stiffness of this + + + align:start position:0% +are like as you know stiffness of this +thing and also something energy + + align:start position:0% +thing and also something energy + + + align:start position:0% +thing and also something energy +dissipation etcetera but you can see + + align:start position:0% +dissipation etcetera but you can see + + + align:start position:0% +dissipation etcetera but you can see +that sort of we can as we use our + + align:start position:0% +that sort of we can as we use our + + + align:start position:0% +that sort of we can as we use our +calculation to explain this pattern + + align:start position:0% +calculation to explain this pattern + + + align:start position:0% +calculation to explain this pattern +that's really cool + + align:start position:0% +that's really cool + + + align:start position:0% +that's really cool +right and the advantage is that now I + + align:start position:0% +right and the advantage is that now I + + + align:start position:0% +right and the advantage is that now I +have this wonderful simulation I can put + + align:start position:0% +have this wonderful simulation I can put + + + align:start position:0% +have this wonderful simulation I can put +in all the crazy numbers and you will + + align:start position:0% +in all the crazy numbers and you will + + + align:start position:0% +in all the crazy numbers and you will +see that ha if I increase the K value + + align:start position:0% +see that ha if I increase the K value + + + align:start position:0% +see that ha if I increase the K value +and I can actually really make all kinds + + align:start position:0% +and I can actually really make all kinds + + + align:start position:0% +and I can actually really make all kinds +of ridiculous pattern out of this and + + align:start position:0% +of ridiculous pattern out of this and + + + align:start position:0% +of ridiculous pattern out of this and +that all these things Inc actually be + + align:start position:0% +that all these things Inc actually be + + + align:start position:0% +that all these things Inc actually be +kind of realized by this experiment so + + align:start position:0% +kind of realized by this experiment so + + + align:start position:0% +kind of realized by this experiment so +you can see that for example I can now + + align:start position:0% +you can see that for example I can now + + + align:start position:0% +you can see that for example I can now +also turn on this and I can actually + + align:start position:0% +also turn on this and I can actually + + + align:start position:0% +also turn on this and I can actually +increase the temperature so that you + + align:start position:0% +increase the temperature so that you + + + align:start position:0% +increase the temperature so that you +increase the frequency to very high + + align:start position:0% +increase the frequency to very high + + + align:start position:0% +increase the frequency to very high +frequency for example + + align:start position:0% +frequency for example + + + align:start position:0% +frequency for example +then I can see that all the pattern + + align:start position:0% +then I can see that all the pattern + + + align:start position:0% +then I can see that all the pattern +really become much more complicating + + align:start position:0% + + + + align:start position:0% + +right now I have a circle and there are + + align:start position:0% +right now I have a circle and there are + + + align:start position:0% +right now I have a circle and there are +many many more structures which is in in + + align:start position:0% +many many more structures which is in in + + + align:start position:0% +many many more structures which is in in +the surrounding area and of course I can + + align:start position:0% +the surrounding area and of course I can + + + align:start position:0% +the surrounding area and of course I can +again increase increase and see what + + align:start position:0% +again increase increase and see what + + + align:start position:0% +again increase increase and see what +happened I don't know what is going to + + align:start position:0% +happened I don't know what is going to + + + align:start position:0% +happened I don't know what is going to +happen because every time I do this + + align:start position:0% +happen because every time I do this + + + align:start position:0% +happen because every time I do this +experiment I get a different pattern + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +now this seems to be a very nice + + align:start position:0% +now this seems to be a very nice + + + align:start position:0% +now this seems to be a very nice +frequency it's getting harder and harder + + align:start position:0% + + + + align:start position:0% + +you can see that this is it looks really + + align:start position:0% +you can see that this is it looks really + + + align:start position:0% +you can see that this is it looks really +crazy + + align:start position:0% +crazy + + + align:start position:0% +crazy +holy mackerel right what is what the + + align:start position:0% +holy mackerel right what is what the + + + align:start position:0% +holy mackerel right what is what the +hell is this right so you can see that + + align:start position:0% +hell is this right so you can see that + + + align:start position:0% +hell is this right so you can see that +all this crazy pattern K can be can be + + align:start position:0% +all this crazy pattern K can be can be + + + align:start position:0% +all this crazy pattern K can be can be +created and of course during the break + + align:start position:0% +created and of course during the break + + + align:start position:0% +created and of course during the break +you are welcome to come over and play + + align:start position:0% +you are welcome to come over and play + + + align:start position:0% +you are welcome to come over and play +with this so you can see that we can + + align:start position:0% +with this so you can see that we can + + + align:start position:0% +with this so you can see that we can +actually understand sort of the pattern + + align:start position:0% +actually understand sort of the pattern + + + align:start position:0% +actually understand sort of the pattern +produced from this experiment that's + + align:start position:0% +produced from this experiment that's + + + align:start position:0% +produced from this experiment that's +actually very exciting because that's + + align:start position:0% +actually very exciting because that's + + + align:start position:0% +actually very exciting because that's +actually why we are physicists right we + + align:start position:0% +actually why we are physicists right we + + + align:start position:0% +actually why we are physicists right we +would like to know why those patterns + + align:start position:0% +would like to know why those patterns + + + align:start position:0% +would like to know why those patterns +are formed and now you know why those + + align:start position:0% +are formed and now you know why those + + + align:start position:0% +are formed and now you know why those +patterns are formed because there are no + + align:start position:0% +patterns are formed because there are no + + + align:start position:0% +patterns are formed because there are no +lines in these two dimensional normal + + align:start position:0% +lines in these two dimensional normal + + + align:start position:0% +lines in these two dimensional normal +modes and the lost sense really love to + + align:start position:0% +modes and the lost sense really love to + + + align:start position:0% +modes and the lost sense really love to +sit there because you want to sit in the + + align:start position:0% +sit there because you want to sit in the + + + align:start position:0% +sit there because you want to sit in the +press which we you don't have a lot of + + align:start position:0% +press which we you don't have a lot of + + + align:start position:0% +press which we you don't have a lot of +vibration it's not very comfortable + + align:start position:0% +vibration it's not very comfortable + + + align:start position:0% +vibration it's not very comfortable +right so so you sit in the press which + + align:start position:0% +right so so you sit in the press which + + + align:start position:0% +right so so you sit in the press which +mmm + + align:start position:0% +mmm + + + align:start position:0% +mmm +my brain is your problem where is your + + align:start position:0% +my brain is your problem where is your + + + align:start position:0% +my brain is your problem where is your +problem I sit here where there were no + + align:start position:0% +problem I sit here where there were no + + + align:start position:0% +problem I sit here where there were no +vibration right so that's actually how + + align:start position:0% +vibration right so that's actually how + + + align:start position:0% +vibration right so that's actually how +we actually explain these strange + + align:start position:0% +we actually explain these strange + + + align:start position:0% +we actually explain these strange +figures which we can see and just for + + align:start position:0% +figures which we can see and just for + + + align:start position:0% +figures which we can see and just for +fun you can see that I can also generate + + align:start position:0% +fun you can see that I can also generate + + + align:start position:0% +fun you can see that I can also generate +all kinds of craziness you can input all + + align:start position:0% +all kinds of craziness you can input all + + + align:start position:0% +all kinds of craziness you can input all +kinds of different an x and y value and + + align:start position:0% +kinds of different an x and y value and + + + align:start position:0% +kinds of different an x and y value and +you get all those wonderful figures for + + align:start position:0% +you get all those wonderful figures for + + + align:start position:0% +you get all those wonderful figures for +free maybe we can actually make some + + align:start position:0% +free maybe we can actually make some + + + align:start position:0% +free maybe we can actually make some +t-shirt with all those figures are on + + align:start position:0% +t-shirt with all those figures are on + + + align:start position:0% +t-shirt with all those figures are on +the t-shirt right okay so we had a lot + + align:start position:0% +the t-shirt right okay so we had a lot + + + align:start position:0% +the t-shirt right okay so we had a lot +of fun with this two-dimensional parade + + align:start position:0% +of fun with this two-dimensional parade + + + align:start position:0% +of fun with this two-dimensional parade +how about what would happen if I have a + + align:start position:0% +how about what would happen if I have a + + + align:start position:0% +how about what would happen if I have a +circular parade okay what what does it + + align:start position:0% +circular parade okay what what does it + + + align:start position:0% +circular parade okay what what does it +do okay unfortunately I will not be able + + align:start position:0% +do okay unfortunately I will not be able + + + align:start position:0% +do okay unfortunately I will not be able +to solve the two-dimensional prey + + align:start position:0% +to solve the two-dimensional prey + + + align:start position:0% +to solve the two-dimensional prey +problem in front of you because that + + align:start position:0% +problem in front of you because that + + + align:start position:0% +problem in front of you because that +will give you a passive function right + + align:start position:0% +will give you a passive function right + + + align:start position:0% +will give you a passive function right +which is not the end of the world + + align:start position:0% +which is not the end of the world + + + align:start position:0% +which is not the end of the world +but there is actually kind of + + align:start position:0% +but there is actually kind of + + + align:start position:0% +but there is actually kind of +complicated if I put it in the meter + + align:start position:0% +complicated if I put it in the meter + + + align:start position:0% +complicated if I put it in the meter +exam that says you're not very + + align:start position:0% +exam that says you're not very + + + align:start position:0% +exam that says you're not very +encouraging right so so but I can + + align:start position:0% +encouraging right so so but I can + + + align:start position:0% +encouraging right so so but I can +actually tell you what will be the + + align:start position:0% +actually tell you what will be the + + + align:start position:0% +actually tell you what will be the +solution the solution will be a part of + + align:start position:0% +solution the solution will be a part of + + + align:start position:0% +solution the solution will be a part of +function so basically you will have a + + align:start position:0% +function so basically you will have a + + + align:start position:0% +function so basically you will have a +lot of rings ring like structure if I + + align:start position:0% +lot of rings ring like structure if I + + + align:start position:0% +lot of rings ring like structure if I +have a circuit + + align:start position:0% +have a circuit + + + align:start position:0% +have a circuit +prayed okay and I can actually do an + + align:start position:0% +prayed okay and I can actually do an + + + align:start position:0% +prayed okay and I can actually do an +experiment which racially so shoot the + + align:start position:0% +experiment which racially so shoot the + + + align:start position:0% +experiment which racially so shoot the +behavior of the circular boundary + + align:start position:0% +behavior of the circular boundary + + + align:start position:0% +behavior of the circular boundary +condition and see what kind of pattern + + align:start position:0% +condition and see what kind of pattern + + + align:start position:0% +condition and see what kind of pattern +can we as you see so here I have a + + align:start position:0% +can we as you see so here I have a + + + align:start position:0% +can we as you see so here I have a +Catholic kind of complicated experiment + + align:start position:0% +Catholic kind of complicated experiment + + + align:start position:0% +Catholic kind of complicated experiment +okay so here I have this ring which I + + align:start position:0% +okay so here I have this ring which I + + + align:start position:0% +okay so here I have this ring which I +would like to produce a soap film and on + + align:start position:0% +would like to produce a soap film and on + + + align:start position:0% +would like to produce a soap film and on +this ring okay so see if I and + + align:start position:0% +this ring okay so see if I and + + + align:start position:0% +this ring okay so see if I and +successful kind of okay now I can put + + align:start position:0% +successful kind of okay now I can put + + + align:start position:0% +successful kind of okay now I can put +this soft film in front of in front of + + align:start position:0% +this soft film in front of in front of + + + align:start position:0% +this soft film in front of in front of +in front of the speaker okay I can + + align:start position:0% +in front of the speaker okay I can + + + align:start position:0% +in front of the speaker okay I can +actually isolate the this scene filmed + + align:start position:0% +actually isolate the this scene filmed + + + align:start position:0% +actually isolate the this scene filmed +the membranes by the speaker okay who + + align:start position:0% +the membranes by the speaker okay who + + + align:start position:0% +the membranes by the speaker okay who +don't want to destroy everything here + + align:start position:0% +don't want to destroy everything here + + + align:start position:0% +don't want to destroy everything here +alright so now I can turn down this so + + align:start position:0% +alright so now I can turn down this so + + + align:start position:0% +alright so now I can turn down this so +that we have light and of course I will + + align:start position:0% +that we have light and of course I will + + + align:start position:0% +that we have light and of course I will +turn on the signal generator so that I + + align:start position:0% +turn on the signal generator so that I + + + align:start position:0% +turn on the signal generator so that I +can hear + + align:start position:0% +can hear + + + align:start position:0% +can hear +Hercules she start to vibrate the + + align:start position:0% +Hercules she start to vibrate the + + + align:start position:0% +Hercules she start to vibrate the +membranes and before I do that I have to + + align:start position:0% +membranes and before I do that I have to + + + align:start position:0% +membranes and before I do that I have to +turn everything off right height images + + align:start position:0% +turn everything off right height images + + + align:start position:0% +turn everything off right height images +hide hide + + align:start position:0% +hide hide + + + align:start position:0% +hide hide +alright I hope you can see something can + + align:start position:0% +alright I hope you can see something can + + + align:start position:0% +alright I hope you can see something can +you can you see something + + align:start position:0% +you can you see something + + + align:start position:0% +you can you see something +and okay is kind of difficult to see it + + align:start position:0% +and okay is kind of difficult to see it + + + align:start position:0% +and okay is kind of difficult to see it +okay but that should be there okay now I + + align:start position:0% +okay but that should be there okay now I + + + align:start position:0% +okay but that should be there okay now I +can turn on this speaker and you can see + + align:start position:0% +can turn on this speaker and you can see + + + align:start position:0% +can turn on this speaker and you can see +that there are some pattern which you + + align:start position:0% +that there are some pattern which you + + + align:start position:0% +that there are some pattern which you +still probably difficult to see + + align:start position:0% +still probably difficult to see + + + align:start position:0% +still probably difficult to see +kind of see right there are some rings + + align:start position:0% +kind of see right there are some rings + + + align:start position:0% +kind of see right there are some rings +you can see on the picture so you can + + align:start position:0% +you can see on the picture so you can + + + align:start position:0% +you can see on the picture so you can +see that now I have one - sweet sweet + + align:start position:0% +see that now I have one - sweet sweet + + + align:start position:0% +see that now I have one - sweet sweet +rings right kind of because I couldn't + + align:start position:0% +rings right kind of because I couldn't + + + align:start position:0% +rings right kind of because I couldn't +actually a turn of the okay turn of the + + align:start position:0% +actually a turn of the okay turn of the + + + align:start position:0% +actually a turn of the okay turn of the +light which is as you've emitted from + + align:start position:0% +light which is as you've emitted from + + + align:start position:0% +light which is as you've emitted from +the on the Sun right okay so I cannot + + align:start position:0% +the on the Sun right okay so I cannot + + + align:start position:0% +the on the Sun right okay so I cannot +turn off Sun therefore you can you can + + align:start position:0% +turn off Sun therefore you can you can + + + align:start position:0% +turn off Sun therefore you can you can +barely see this figure also this expose + + align:start position:0% +barely see this figure also this expose + + + align:start position:0% +barely see this figure also this expose +the reliability experiment and you can + + align:start position:0% +the reliability experiment and you can + + + align:start position:0% +the reliability experiment and you can +see that if I increase the frequency + + align:start position:0% +see that if I increase the frequency + + + align:start position:0% +see that if I increase the frequency +okay according to the solution from the + + align:start position:0% +okay according to the solution from the + + + align:start position:0% +okay according to the solution from the +Bessel function you will see more rings + + align:start position:0% +Bessel function you will see more rings + + + align:start position:0% +Bessel function you will see more rings +I got excited + + align:start position:0% +I got excited + + + align:start position:0% +I got excited +right so you can see that now I have one + + align:start position:0% +right so you can see that now I have one + + + align:start position:0% +right so you can see that now I have one +two three four four rings and of course + + align:start position:0% +two three four four rings and of course + + + align:start position:0% +two three four four rings and of course +I can continue to increase increase and + + align:start position:0% +I can continue to increase increase and + + + align:start position:0% +I can continue to increase increase and +increase and you will see that there are + + align:start position:0% +increase and you will see that there are + + + align:start position:0% +increase and you will see that there are +even more rings well produced is + + align:start position:0% +even more rings well produced is + + + align:start position:0% +even more rings well produced is +essentially what I am doing is actually + + align:start position:0% +essentially what I am doing is actually + + + align:start position:0% +essentially what I am doing is actually +really trying to buy beret and excite + + align:start position:0% +really trying to buy beret and excite + + + align:start position:0% +really trying to buy beret and excite +one of the normal mall by this + + align:start position:0% +one of the normal mall by this + + + align:start position:0% +one of the normal mall by this +loudspeaker okay and you can actually + + align:start position:0% +loudspeaker okay and you can actually + + + align:start position:0% +loudspeaker okay and you can actually +kind of see I hope you can kind of see + + align:start position:0% +kind of see I hope you can kind of see + + + align:start position:0% +kind of see I hope you can kind of see +it okay + + align:start position:0% +it okay + + + align:start position:0% +it okay +if you can still see it that means you + + align:start position:0% +if you can still see it that means you + + + align:start position:0% +if you can still see it that means you +you need to check your eye because the + + align:start position:0% +you need to check your eye because the + + + align:start position:0% +you need to check your eye because the +remembrance is broken all right + + align:start position:0% +remembrance is broken all right + + + align:start position:0% +remembrance is broken all right +okay so I think you sort don't get this + + align:start position:0% +okay so I think you sort don't get this + + + align:start position:0% +okay so I think you sort don't get this +idea and I'm going to turn off this + + align:start position:0% +idea and I'm going to turn off this + + + align:start position:0% +idea and I'm going to turn off this +wonderful machine and and go back to the + + align:start position:0% +wonderful machine and and go back to the + + + align:start position:0% +wonderful machine and and go back to the +the lecture so this experiment is kind + + align:start position:0% +the lecture so this experiment is kind + + + align:start position:0% +the lecture so this experiment is kind +of hard to reproduce in your study right + + align:start position:0% +of hard to reproduce in your study right + + + align:start position:0% +of hard to reproduce in your study right +right + + align:start position:0% +right + + + align:start position:0% +right +I think everybody will agree and there + + align:start position:0% +I think everybody will agree and there + + + align:start position:0% +I think everybody will agree and there +is another one which is essentially kind + + align:start position:0% +is another one which is essentially kind + + + align:start position:0% +is another one which is essentially kind +of easy to reproduce which I would + + align:start position:0% +of easy to reproduce which I would + + + align:start position:0% +of easy to reproduce which I would +encourage you to try it okay so if you + + align:start position:0% +encourage you to try it okay so if you + + + align:start position:0% +encourage you to try it okay so if you +have time so this is actually from Jake + + align:start position:0% +have time so this is actually from Jake + + + align:start position:0% +have time so this is actually from Jake +he and she sent me this wonderful video + + align:start position:0% +he and she sent me this wonderful video + + + align:start position:0% +he and she sent me this wonderful video +when I was teaching the arrows because + + align:start position:0% +when I was teaching the arrows because + + + align:start position:0% +when I was teaching the arrows because +they found that they can excite two + + align:start position:0% +they found that they can excite two + + + align:start position:0% +they found that they can excite two +dimensional wave in this way can you see + + align:start position:0% +dimensional wave in this way can you see + + + align:start position:0% +dimensional wave in this way can you see +it it's wonderful you can see they're + + align:start position:0% +it it's wonderful you can see they're + + + align:start position:0% +it it's wonderful you can see they're +very high frequency oscillation which + + align:start position:0% +very high frequency oscillation which + + + align:start position:0% +very high frequency oscillation which +actually excite this two-dimensional + + align:start position:0% +actually excite this two-dimensional + + + align:start position:0% +actually excite this two-dimensional +wave and you can see that lots lots lots + + align:start position:0% +wave and you can see that lots lots lots + + + align:start position:0% +wave and you can see that lots lots lots +of rings are actually excited and you + + align:start position:0% +of rings are actually excited and you + + + align:start position:0% +of rings are actually excited and you +can see very clearly different this this + + align:start position:0% +can see very clearly different this this + + + align:start position:0% +can see very clearly different this this +simple experiment what you really need + + align:start position:0% +simple experiment what you really need + + + align:start position:0% +simple experiment what you really need +is a cup of water and you rub it against + + align:start position:0% +is a cup of water and you rub it against + + + align:start position:0% +is a cup of water and you rub it against +the surface of a table then you will be + + align:start position:0% +the surface of a table then you will be + + + align:start position:0% +the surface of a table then you will be +able to excite all the crazy patterns + + align:start position:0% +able to excite all the crazy patterns + + + align:start position:0% +able to excite all the crazy patterns +which we can actually see from this + + align:start position:0% +which we can actually see from this + + + align:start position:0% +which we can actually see from this +two-dimensional system and with two + + align:start position:0% +two-dimensional system and with two + + + align:start position:0% +two-dimensional system and with two +dimensional boundary conditions okay so + + align:start position:0% +dimensional boundary conditions okay so + + + align:start position:0% +dimensional boundary conditions okay so +we will take a five-minute break before + + align:start position:0% +we will take a five-minute break before + + + align:start position:0% +we will take a five-minute break before +we enter the next part of the discussion + + align:start position:0% +we enter the next part of the discussion + + + align:start position:0% +we enter the next part of the discussion +and we come back at 35 + + align:start position:0% + + + + align:start position:0% + +okay welcome back everybody + + align:start position:0% +okay welcome back everybody + + + align:start position:0% +okay welcome back everybody +so what I'm going to do now is to + + align:start position:0% +so what I'm going to do now is to + + + align:start position:0% +so what I'm going to do now is to +continue the discussion what we actually + + align:start position:0% +continue the discussion what we actually + + + align:start position:0% +continue the discussion what we actually +got started of the two dimensional and + + align:start position:0% +got started of the two dimensional and + + + align:start position:0% +got started of the two dimensional and +three dimensional system and we have + + align:start position:0% +three dimensional system and we have + + + align:start position:0% +three dimensional system and we have +underst we have actually studied that + + align:start position:0% +underst we have actually studied that + + + align:start position:0% +underst we have actually studied that +behavior of standing wave ray or normal + + align:start position:0% +behavior of standing wave ray or normal + + + align:start position:0% +behavior of standing wave ray or normal +more for what this two dimensional + + align:start position:0% +more for what this two dimensional + + + align:start position:0% +more for what this two dimensional +system and what I am going to do is to + + align:start position:0% +system and what I am going to do is to + + + align:start position:0% +system and what I am going to do is to +discuss with you a two dimensional + + align:start position:0% +discuss with you a two dimensional + + + align:start position:0% +discuss with you a two dimensional +focusing wave okay so I will stick to a + + align:start position:0% +focusing wave okay so I will stick to a + + + align:start position:0% +focusing wave okay so I will stick to a +really simple example which are plane + + align:start position:0% +really simple example which are plane + + + align:start position:0% +really simple example which are plane +waves okay so in the case of plane wave + + align:start position:0% +waves okay so in the case of plane wave + + + align:start position:0% +waves okay so in the case of plane wave +which we actually discussed when + + align:start position:0% +which we actually discussed when + + + align:start position:0% +which we actually discussed when +actually when we actually discussed the + + align:start position:0% +actually when we actually discussed the + + + align:start position:0% +actually when we actually discussed the +young waves as we have the following + + align:start position:0% +young waves as we have the following + + + align:start position:0% +young waves as we have the following +functional for sigh is a function of R + + align:start position:0% +functional for sigh is a function of R + + + align:start position:0% +functional for sigh is a function of R +and the T and this will be equal to a + + align:start position:0% +and the T and this will be equal to a + + + align:start position:0% +and the T and this will be equal to a +exponential I K is a should lock a is a + + align:start position:0% +exponential I K is a should lock a is a + + + align:start position:0% +exponential I K is a should lock a is a +vector now and is pointing to the + + align:start position:0% +vector now and is pointing to the + + + align:start position:0% +vector now and is pointing to the +direction of the propagation of this + + align:start position:0% +direction of the propagation of this + + + align:start position:0% +direction of the propagation of this +prang wave and the disc a is thought + + align:start position:0% +prang wave and the disc a is thought + + + align:start position:0% +prang wave and the disc a is thought +with our vector minus Omega T which is + + align:start position:0% +with our vector minus Omega T which is + + + align:start position:0% +with our vector minus Omega T which is +the oscillation frequency angular + + align:start position:0% +the oscillation frequency angular + + + align:start position:0% +the oscillation frequency angular +frequency and evaluate E at a specific + + align:start position:0% +frequency and evaluate E at a specific + + + align:start position:0% +frequency and evaluate E at a specific +time and this issue this expression I + + align:start position:0% +time and this issue this expression I + + + align:start position:0% +time and this issue this expression I +should describe a plane wave where the + + align:start position:0% +should describe a plane wave where the + + + align:start position:0% +should describe a plane wave where the +direction of propagation is described by + + align:start position:0% +direction of propagation is described by + + + align:start position:0% +direction of propagation is described by +this K vector and of course you can + + align:start position:0% +this K vector and of course you can + + + align:start position:0% +this K vector and of course you can +actually have the wave front which is + + align:start position:0% +actually have the wave front which is + + + align:start position:0% +actually have the wave front which is +actually the peak position of this pram + + align:start position:0% +actually the peak position of this pram + + + align:start position:0% +actually the peak position of this pram +wave okay and the distance between the + + align:start position:0% +wave okay and the distance between the + + + align:start position:0% +wave okay and the distance between the +peak position okay so you can imagine + + align:start position:0% +peak position okay so you can imagine + + + align:start position:0% +peak position okay so you can imagine +that this is like this + + align:start position:0% + + + + align:start position:0% + +second is too wide right so if you if + + align:start position:0% +second is too wide right so if you if + + + align:start position:0% +second is too wide right so if you if +you look at the distance between peak + + align:start position:0% +you look at the distance between peak + + + align:start position:0% +you look at the distance between peak +position that will give you the + + align:start position:0% +position that will give you the + + + align:start position:0% +position that will give you the +wavelength right the wavelength lambda + + align:start position:0% +wavelength right the wavelength lambda + + + align:start position:0% +wavelength right the wavelength lambda +will be equal to 2pi divided by K right + + align:start position:0% +will be equal to 2pi divided by K right + + + align:start position:0% +will be equal to 2pi divided by K right +in this case is the lens of this K + + align:start position:0% +in this case is the lens of this K + + + align:start position:0% +in this case is the lens of this K +vector okay just a reminder about what + + align:start position:0% +vector okay just a reminder about what + + + align:start position:0% +vector okay just a reminder about what +we actually introduced in the previous + + align:start position:0% +we actually introduced in the previous + + + align:start position:0% +we actually introduced in the previous +lecture and we were using this to + + align:start position:0% +lecture and we were using this to + + + align:start position:0% +lecture and we were using this to +describe electromagnetic wave and the + + align:start position:0% +describe electromagnetic wave and the + + + align:start position:0% +describe electromagnetic wave and the +such kind of expression can be also be + + align:start position:0% +such kind of expression can be also be + + + align:start position:0% +such kind of expression can be also be +used to describe some waves and also + + align:start position:0% +used to describe some waves and also + + + align:start position:0% +used to describe some waves and also +vibration on the membranes etc focusing + + align:start position:0% +vibration on the membranes etc focusing + + + align:start position:0% +vibration on the membranes etc focusing +waves okay so if there are no other + + align:start position:0% +waves okay so if there are no other + + + align:start position:0% +waves okay so if there are no other +median okay like what we actually have + + align:start position:0% +median okay like what we actually have + + + align:start position:0% +median okay like what we actually have +in this slide so we have nothing else I + + align:start position:0% +in this slide so we have nothing else I + + + align:start position:0% +in this slide so we have nothing else I +have a membranes with surface tension T + + align:start position:0% +have a membranes with surface tension T + + + align:start position:0% +have a membranes with surface tension T +s and Rho s fish with the mass per unit + + align:start position:0% +s and Rho s fish with the mass per unit + + + align:start position:0% +s and Rho s fish with the mass per unit +area then basically this focusing wave + + align:start position:0% +area then basically this focusing wave + + + align:start position:0% +area then basically this focusing wave +is going to be traveling at the speed of + + align:start position:0% +is going to be traveling at the speed of + + + align:start position:0% +is going to be traveling at the speed of +V which is actually equal to square root + + align:start position:0% +V which is actually equal to square root + + + align:start position:0% +V which is actually equal to square root +of T s over Rho s and I can actually + + align:start position:0% +of T s over Rho s and I can actually + + + align:start position:0% +of T s over Rho s and I can actually +find that to be some constant C / M okay + + align:start position:0% +find that to be some constant C / M okay + + + align:start position:0% +find that to be some constant C / M okay +so C is a some constant and n is + + align:start position:0% +so C is a some constant and n is + + + align:start position:0% +so C is a some constant and n is +actually another constant which actually + + align:start position:0% +actually another constant which actually + + + align:start position:0% +actually another constant which actually +the ratio CN NS s equal to B and I will + + align:start position:0% +the ratio CN NS s equal to B and I will + + + align:start position:0% +the ratio CN NS s equal to B and I will +need that expression later only later + + align:start position:0% +need that expression later only later + + + align:start position:0% +need that expression later only later +not now if I have nothing else okay and + + align:start position:0% +not now if I have nothing else okay and + + + align:start position:0% +not now if I have nothing else okay and +this is this issue's this system + + align:start position:0% +this is this issue's this system + + + align:start position:0% +this is this issue's this system +actually feel the whole universe then + + align:start position:0% +actually feel the whole universe then + + + align:start position:0% +actually feel the whole universe then +what is going to happen is that this pop + + align:start position:0% +what is going to happen is that this pop + + + align:start position:0% +what is going to happen is that this pop +wasting wave is going to be propagating + + align:start position:0% +wasting wave is going to be propagating + + + align:start position:0% +wasting wave is going to be propagating +propagating propagating propagating + + align:start position:0% +propagating propagating propagating + + + align:start position:0% +propagating propagating propagating +nursing will change and until at the + + align:start position:0% +nursing will change and until at the + + + align:start position:0% +nursing will change and until at the +edge of the universe if it doesn't + + align:start position:0% +edge of the universe if it doesn't + + + align:start position:0% +edge of the universe if it doesn't +actually introduce any excitement right + + align:start position:0% +actually introduce any excitement right + + + align:start position:0% +actually introduce any excitement right +okay so that's what we have already + + align:start position:0% +okay so that's what we have already + + + align:start position:0% +okay so that's what we have already +learned from from Yin + + align:start position:0% +learned from from Yin + + + align:start position:0% +learned from from Yin +we have discussed the electromagnetic + + align:start position:0% +we have discussed the electromagnetic + + + align:start position:0% +we have discussed the electromagnetic +interaction and now the same expression + + align:start position:0% +interaction and now the same expression + + + align:start position:0% +interaction and now the same expression +can also be used for the description of + + align:start position:0% +can also be used for the description of + + + align:start position:0% +can also be used for the description of +the membranes and now to make this + + align:start position:0% +the membranes and now to make this + + + align:start position:0% +the membranes and now to make this +problem more exciting what I'm going to + + align:start position:0% +problem more exciting what I'm going to + + + align:start position:0% +problem more exciting what I'm going to +do is to introduce a boundary right so + + align:start position:0% +do is to introduce a boundary right so + + + align:start position:0% +do is to introduce a boundary right so +the boundary is actually in the middle + + align:start position:0% +the boundary is actually in the middle + + + align:start position:0% +the boundary is actually in the middle +of this slide and I assume that + + align:start position:0% +of this slide and I assume that + + + align:start position:0% +of this slide and I assume that +horizontal direction to be X equal to + + align:start position:0% +horizontal direction to be X equal to + + + align:start position:0% +horizontal direction to be X equal to +zero the horizontal direction to be an X + + align:start position:0% +zero the horizontal direction to be an X + + + align:start position:0% +zero the horizontal direction to be an X +direction and the boundary is at X equal + + align:start position:0% +direction and the boundary is at X equal + + + align:start position:0% +direction and the boundary is at X equal +to zero okay and when when this when you + + align:start position:0% +to zero okay and when when this when you + + + align:start position:0% +to zero okay and when when this when you +pass this boundary there's another kind + + align:start position:0% +pass this boundary there's another kind + + + align:start position:0% +pass this boundary there's another kind +of material with surface tension ts + + align:start position:0% +of material with surface tension ts + + + align:start position:0% +of material with surface tension ts +front and slightly different mass per + + align:start position:0% +front and slightly different mass per + + + align:start position:0% +front and slightly different mass per +unit area Rho s Prime okay based on the + + align:start position:0% +unit area Rho s Prime okay based on the + + + align:start position:0% +unit area Rho s Prime okay based on the +expression we got for the velocity we + + align:start position:0% +expression we got for the velocity we + + + align:start position:0% +expression we got for the velocity we +will be able to conclude that V prime + + align:start position:0% +will be able to conclude that V prime + + + align:start position:0% +will be able to conclude that V prime +will be equal to square root of T prime + + align:start position:0% +will be equal to square root of T prime + + + align:start position:0% +will be equal to square root of T prime +s divided by Rho as prom and that will + + align:start position:0% +s divided by Rho as prom and that will + + + align:start position:0% +s divided by Rho as prom and that will +be equal to C over M Prime and C is the + + align:start position:0% +be equal to C over M Prime and C is the + + + align:start position:0% +be equal to C over M Prime and C is the +same constant which we are used for the + + align:start position:0% +same constant which we are used for the + + + align:start position:0% +same constant which we are used for the +laughing side system and it's actually + + align:start position:0% +laughing side system and it's actually + + + align:start position:0% +laughing side system and it's actually +later you will realize that the cell + + align:start position:0% +later you will realize that the cell + + + align:start position:0% +later you will realize that the cell +refraction index in in a discussion okay + + align:start position:0% +refraction index in in a discussion okay + + + align:start position:0% +refraction index in in a discussion okay +so the question which I would like to + + align:start position:0% +so the question which I would like to + + + align:start position:0% +so the question which I would like to +ask is okay now I have a plane wave okay + + align:start position:0% +ask is okay now I have a plane wave okay + + + align:start position:0% +ask is okay now I have a plane wave okay +propagating in the first system and + + align:start position:0% +propagating in the first system and + + + align:start position:0% +propagating in the first system and +Ahmet it meet a boundary and the + + align:start position:0% +Ahmet it meet a boundary and the + + + align:start position:0% +Ahmet it meet a boundary and the +question is what will happen okay when + + align:start position:0% +question is what will happen okay when + + + align:start position:0% +question is what will happen okay when +when I have the incident wave coming + + align:start position:0% +when I have the incident wave coming + + + align:start position:0% +when I have the incident wave coming +into this system okay so before that I + + align:start position:0% +into this system okay so before that I + + + align:start position:0% +into this system okay so before that I +also need to write down the dispersion + + align:start position:0% +also need to write down the dispersion + + + align:start position:0% +also need to write down the dispersion +relation right so this person relation + + align:start position:0% +relation right so this person relation + + + align:start position:0% +relation right so this person relation +can be obtained by plugging in normal + + align:start position:0% +can be obtained by plugging in normal + + + align:start position:0% +can be obtained by plugging in normal +mode sine function size function into + + align:start position:0% +mode sine function size function into + + + align:start position:0% +mode sine function size function into +the wave equation + + align:start position:0% +the wave equation + + + align:start position:0% +the wave equation +right so while I can issue in meeting + + align:start position:0% +right so while I can issue in meeting + + + align:start position:0% +right so while I can issue in meeting +the up 10 is that the dispersion + + align:start position:0% +the up 10 is that the dispersion + + + align:start position:0% +the up 10 is that the dispersion +relation Omega square is actually equal + + align:start position:0% +relation Omega square is actually equal + + + align:start position:0% +relation Omega square is actually equal +to three square KX square plus KY square + + align:start position:0% +to three square KX square plus KY square + + + align:start position:0% +to three square KX square plus KY square +so you can actually check this + + align:start position:0% +so you can actually check this + + + align:start position:0% +so you can actually check this +expression by plugging in this function + + align:start position:0% +expression by plugging in this function + + + align:start position:0% +expression by plugging in this function +into the two dimensional wave equation + + align:start position:0% +into the two dimensional wave equation + + + align:start position:0% +into the two dimensional wave equation +and you will get that expression okay + + align:start position:0% +and you will get that expression okay + + + align:start position:0% +and you will get that expression okay +and that means Omega cannot be arbitrary + + align:start position:0% +and that means Omega cannot be arbitrary + + + align:start position:0% +and that means Omega cannot be arbitrary +number it's as you decided by KX and KY + + align:start position:0% +number it's as you decided by KX and KY + + + align:start position:0% +number it's as you decided by KX and KY +okay or say if Omega S decide and the + + align:start position:0% +okay or say if Omega S decide and the + + + align:start position:0% +okay or say if Omega S decide and the +one of the K is decide then the third + + align:start position:0% +one of the K is decide then the third + + + align:start position:0% +one of the K is decide then the third +number for example in this case KX is as + + align:start position:0% +number for example in this case KX is as + + + align:start position:0% +number for example in this case KX is as +we decided by the dispersion relation + + align:start position:0% +we decided by the dispersion relation + + + align:start position:0% +we decided by the dispersion relation +which we have here okay so coming back + + align:start position:0% +which we have here okay so coming back + + + align:start position:0% +which we have here okay so coming back +to the original problem we are we are + + align:start position:0% +to the original problem we are we are + + + align:start position:0% +to the original problem we are we are +posting so I have now the in certain + + align:start position:0% +posting so I have now the in certain + + + align:start position:0% +posting so I have now the in certain +wave coming into this system okay I + + align:start position:0% +wave coming into this system okay I + + + align:start position:0% +wave coming into this system okay I +would like to know what will happen at + + align:start position:0% +would like to know what will happen at + + + align:start position:0% +would like to know what will happen at +the boundary right when I have two + + align:start position:0% +the boundary right when I have two + + + align:start position:0% +the boundary right when I have two +system with lap inside propagating at + + align:start position:0% +system with lap inside propagating at + + + align:start position:0% +system with lap inside propagating at +the speed of the propagation is V and + + align:start position:0% +the speed of the propagation is V and + + + align:start position:0% +the speed of the propagation is V and +right hand side speed of propagation is + + align:start position:0% +right hand side speed of propagation is + + + align:start position:0% +right hand side speed of propagation is +V Prime + + align:start position:0% +V Prime + + + align:start position:0% +V Prime +what is going to happen as you might + + align:start position:0% +what is going to happen as you might + + + align:start position:0% +what is going to happen as you might +guess that I am going to get refractive + + align:start position:0% +guess that I am going to get refractive + + + align:start position:0% +guess that I am going to get refractive +wave and a transmitted wave right so + + align:start position:0% +wave and a transmitted wave right so + + + align:start position:0% +wave and a transmitted wave right so +that's actually based on what we have + + align:start position:0% +that's actually based on what we have + + + align:start position:0% +that's actually based on what we have +there from the one-dimensional system + + align:start position:0% +there from the one-dimensional system + + + align:start position:0% +there from the one-dimensional system +right if I call this the left hand side + + align:start position:0% +right if I call this the left hand side + + + align:start position:0% +right if I call this the left hand side +and call the right hand side system I + + align:start position:0% +and call the right hand side system I + + + align:start position:0% +and call the right hand side system I +know the right hand side system are okay + + align:start position:0% +know the right hand side system are okay + + + align:start position:0% +know the right hand side system are okay +so I can write down the wave function + + align:start position:0% +so I can write down the wave function + + + align:start position:0% +so I can write down the wave function +side L describing the left hand side + + align:start position:0% +side L describing the left hand side + + + align:start position:0% +side L describing the left hand side +this will be equal to a exponential I K + + align:start position:0% +this will be equal to a exponential I K + + + align:start position:0% +this will be equal to a exponential I K +dot R minus make up this is actually the + + align:start position:0% +dot R minus make up this is actually the + + + align:start position:0% +dot R minus make up this is actually the +incident wave + + align:start position:0% + + + + align:start position:0% + +describing this incident wave and as + + align:start position:0% +describing this incident wave and as + + + align:start position:0% +describing this incident wave and as +will my guess there should be some kind + + align:start position:0% +will my guess there should be some kind + + + align:start position:0% +will my guess there should be some kind +of refraction right so once this wave + + align:start position:0% +of refraction right so once this wave + + + align:start position:0% +of refraction right so once this wave +actually passed through the boundary or + + align:start position:0% +actually passed through the boundary or + + + align:start position:0% +actually passed through the boundary or +touch the boundary there should be some + + align:start position:0% +touch the boundary there should be some + + + align:start position:0% +touch the boundary there should be some +kind of infraction right so the + + align:start position:0% +kind of infraction right so the + + + align:start position:0% +kind of infraction right so the +refraction I can actually write it down + + align:start position:0% +refraction I can actually write it down + + + align:start position:0% +refraction I can actually write it down +in this for a sum over alpha R alpha is + + align:start position:0% +in this for a sum over alpha R alpha is + + + align:start position:0% +in this for a sum over alpha R alpha is +actually the coefficient or mp2 as + + align:start position:0% +actually the coefficient or mp2 as + + + align:start position:0% +actually the coefficient or mp2 as +function of the normal modes with a + + align:start position:0% +function of the normal modes with a + + + align:start position:0% +function of the normal modes with a +function of the focusing wave wave + + align:start position:0% +function of the focusing wave wave + + + align:start position:0% +function of the focusing wave wave +number which I assumed and the I can as + + align:start position:0% +number which I assumed and the I can as + + + align:start position:0% +number which I assumed and the I can as +you sum over all kinds of policy wave + + align:start position:0% +you sum over all kinds of policy wave + + + align:start position:0% +you sum over all kinds of policy wave +number exponential I K alpha times R + + align:start position:0% +number exponential I K alpha times R + + + align:start position:0% +number exponential I K alpha times R +minus Omega right so this is actually a + + align:start position:0% +minus Omega right so this is actually a + + + align:start position:0% +minus Omega right so this is actually a +general form of refractive wave K alpha + + align:start position:0% +general form of refractive wave K alpha + + + align:start position:0% +general form of refractive wave K alpha +is the quite describing the individual + + align:start position:0% +is the quite describing the individual + + + align:start position:0% +is the quite describing the individual +the direction of the individual + + align:start position:0% +the direction of the individual + + + align:start position:0% +the direction of the individual +refracted wave and alpha is actually + + align:start position:0% +refracted wave and alpha is actually + + + align:start position:0% +refracted wave and alpha is actually +labeled in individual refractive wave + + align:start position:0% +labeled in individual refractive wave + + + align:start position:0% +labeled in individual refractive wave +but I don't know what be the functional + + align:start position:0% +but I don't know what be the functional + + + align:start position:0% +but I don't know what be the functional +form for the K alpha for the moment so + + align:start position:0% +form for the K alpha for the moment so + + + align:start position:0% +form for the K alpha for the moment so +therefore I try to sum over all the the + + align:start position:0% +therefore I try to sum over all the the + + + align:start position:0% +therefore I try to sum over all the the +possible alpha and I would would like to + + align:start position:0% +possible alpha and I would would like to + + + align:start position:0% +possible alpha and I would would like to +figure out what would be the allowed + + align:start position:0% +figure out what would be the allowed + + + align:start position:0% +figure out what would be the allowed +alpha by matching the boundary condition + + align:start position:0% +alpha by matching the boundary condition + + + align:start position:0% +alpha by matching the boundary condition +so in short the right hand side turn the + + align:start position:0% +so in short the right hand side turn the + + + align:start position:0% +so in short the right hand side turn the +session it is quite big that refracted + + align:start position:0% +session it is quite big that refracted + + + align:start position:0% +session it is quite big that refracted +wave okay and finally passing through + + align:start position:0% +wave okay and finally passing through + + + align:start position:0% +wave okay and finally passing through +this boundary condition let's look at + + align:start position:0% +this boundary condition let's look at + + + align:start position:0% +this boundary condition let's look at +the right hand side okay right hand side + + align:start position:0% +the right hand side okay right hand side + + + align:start position:0% +the right hand side okay right hand side +side are okay okay it's going to be + + align:start position:0% +side are okay okay it's going to be + + + align:start position:0% +side are okay okay it's going to be +equal to sum over beta all the + + align:start position:0% +equal to sum over beta all the + + + align:start position:0% +equal to sum over beta all the +transmission coefficients top beta has a + + align:start position:0% +transmission coefficients top beta has a + + + align:start position:0% +transmission coefficients top beta has a +which is the original MP to + + align:start position:0% +which is the original MP to + + + align:start position:0% +which is the original MP to +exponential I K beta x times R minus + + align:start position:0% +exponential I K beta x times R minus + + + align:start position:0% +exponential I K beta x times R minus +Omega so again I don't know how what + + align:start position:0% +Omega so again I don't know how what + + + align:start position:0% +Omega so again I don't know how what +would be the behavior of the transmitted + + align:start position:0% +would be the behavior of the transmitted + + + align:start position:0% +would be the behavior of the transmitted +wave therefore I sum over all the + + align:start position:0% +wave therefore I sum over all the + + + align:start position:0% +wave therefore I sum over all the +possible values and this is actually the + + align:start position:0% +possible values and this is actually the + + + align:start position:0% +possible values and this is actually the +functional form for the transmitted wave + + align:start position:0% + + + + align:start position:0% + +okay I also know that K alpha vector + + align:start position:0% +okay I also know that K alpha vector + + + align:start position:0% +okay I also know that K alpha vector +squared will be equal to Omega square + + align:start position:0% +squared will be equal to Omega square + + + align:start position:0% +squared will be equal to Omega square +Rho s over T s and this will be equal to + + align:start position:0% +Rho s over T s and this will be equal to + + + align:start position:0% +Rho s over T s and this will be equal to +Omega square V squared + + align:start position:0% +Omega square V squared + + + align:start position:0% +Omega square V squared +okay because of the dispersion relation + + align:start position:0% +okay because of the dispersion relation + + + align:start position:0% +okay because of the dispersion relation +in the lab hand side right so basically + + align:start position:0% +in the lab hand side right so basically + + + align:start position:0% +in the lab hand side right so basically +if we look at the lab and site + + align:start position:0% +if we look at the lab and site + + + align:start position:0% +if we look at the lab and site +dispersion relation okay the lens square + + align:start position:0% +dispersion relation okay the lens square + + + align:start position:0% +dispersion relation okay the lens square +of this K vector will be equal to Omega + + align:start position:0% +of this K vector will be equal to Omega + + + align:start position:0% +of this K vector will be equal to Omega +square times V squared right this is + + align:start position:0% +square times V squared right this is + + + align:start position:0% +square times V squared right this is +actually just a dispersion relation of a + + align:start position:0% +actually just a dispersion relation of a + + + align:start position:0% +actually just a dispersion relation of a +non dispersive medium right and also I + + align:start position:0% +non dispersive medium right and also I + + + align:start position:0% +non dispersive medium right and also I +can actually figure out what will be the + + align:start position:0% +can actually figure out what will be the + + + align:start position:0% +can actually figure out what will be the +lens for that a lot lens for the cake + + align:start position:0% +lens for that a lot lens for the cake + + + align:start position:0% +lens for that a lot lens for the cake +okay beta right so the K beta square + + align:start position:0% +okay beta right so the K beta square + + + align:start position:0% +okay beta right so the K beta square +will be equal to Omega square V prime + + align:start position:0% +will be equal to Omega square V prime + + + align:start position:0% +will be equal to Omega square V prime +square right because this wave is this + + align:start position:0% +square right because this wave is this + + + align:start position:0% +square right because this wave is this +progressing wave is actually the + + align:start position:0% +progressing wave is actually the + + + align:start position:0% +progressing wave is actually the +transmitted wave is actually traveling + + align:start position:0% +transmitted wave is actually traveling + + + align:start position:0% +transmitted wave is actually traveling +at the second in the second medium okay + + align:start position:0% + + + + align:start position:0% + +so look at what we have done here so we + + align:start position:0% +so look at what we have done here so we + + + align:start position:0% +so look at what we have done here so we +have in certain way we were wondering + + align:start position:0% +have in certain way we were wondering + + + align:start position:0% +have in certain way we were wondering +what is going to happen our physics + + align:start position:0% +what is going to happen our physics + + + align:start position:0% +what is going to happen our physics +intuition tells me that you must get a + + align:start position:0% +intuition tells me that you must get a + + + align:start position:0% +intuition tells me that you must get a +refractive wave oscillation frequency + + align:start position:0% +refractive wave oscillation frequency + + + align:start position:0% +refractive wave oscillation frequency +should be the same otherwise as a + + align:start position:0% +should be the same otherwise as a + + + align:start position:0% +should be the same otherwise as a +function of time you cannot match the + + align:start position:0% +function of time you cannot match the + + + align:start position:0% +function of time you cannot match the +level design right hand side and you + + align:start position:0% +level design right hand side and you + + + align:start position:0% +level design right hand side and you +also get a transmitted wave right but I + + align:start position:0% +also get a transmitted wave right but I + + + align:start position:0% +also get a transmitted wave right but I +need it now in trouble because I have so + + align:start position:0% +need it now in trouble because I have so + + + align:start position:0% +need it now in trouble because I have so +many + + align:start position:0% +many + + + align:start position:0% +many +and summing over alpha infinite number + + align:start position:0% +and summing over alpha infinite number + + + align:start position:0% +and summing over alpha infinite number +of turns and I don't know what would be + + align:start position:0% +of turns and I don't know what would be + + + align:start position:0% +of turns and I don't know what would be +the coefficient for the our alpha and + + align:start position:0% +the coefficient for the our alpha and + + + align:start position:0% +the coefficient for the our alpha and +the Tau Beta which are the transmission + + align:start position:0% +the Tau Beta which are the transmission + + + align:start position:0% +the Tau Beta which are the transmission +coefficient and the refraction + + align:start position:0% +coefficient and the refraction + + + align:start position:0% +coefficient and the refraction +coefficients okay + + align:start position:0% +coefficients okay + + + align:start position:0% +coefficients okay +so what I need to do as you might guess + + align:start position:0% +so what I need to do as you might guess + + + align:start position:0% +so what I need to do as you might guess +is to use the boundary condition right + + align:start position:0% +is to use the boundary condition right + + + align:start position:0% +is to use the boundary condition right +so now I am writing down already the + + align:start position:0% +so now I am writing down already the + + + align:start position:0% +so now I am writing down already the +general expression now I'm going to use + + align:start position:0% +general expression now I'm going to use + + + align:start position:0% +general expression now I'm going to use +the boundary condition to actually limit + + align:start position:0% +the boundary condition to actually limit + + + align:start position:0% +the boundary condition to actually limit +the choice of the possible K alpha and + + align:start position:0% +the choice of the possible K alpha and + + + align:start position:0% +the choice of the possible K alpha and +the K beta what is issue the boundary + + align:start position:0% +the K beta what is issue the boundary + + + align:start position:0% +the K beta what is issue the boundary +condition the boundary conditions are + + align:start position:0% +condition the boundary conditions are + + + align:start position:0% +condition the boundary conditions are +that at x equal to zero okay + + align:start position:0% +that at x equal to zero okay + + + align:start position:0% +that at x equal to zero okay +let's actually add the position of this + + align:start position:0% +let's actually add the position of this + + + align:start position:0% +let's actually add the position of this +line the member ins doesn't break right + + align:start position:0% +line the member ins doesn't break right + + + align:start position:0% +line the member ins doesn't break right +otherwise there's a I mean suddenly the + + align:start position:0% +otherwise there's a I mean suddenly the + + + align:start position:0% +otherwise there's a I mean suddenly the +members I should break and this the end + + align:start position:0% +members I should break and this the end + + + align:start position:0% +members I should break and this the end +of the of the discussion right right + + align:start position:0% +of the of the discussion right right + + + align:start position:0% +of the of the discussion right right +there well we have done before right + + align:start position:0% +there well we have done before right + + + align:start position:0% +there well we have done before right +so the member instant break so that the + + align:start position:0% +so the member instant break so that the + + + align:start position:0% +so the member instant break so that the +propagation can continue right okay so + + align:start position:0% +propagation can continue right okay so + + + align:start position:0% +propagation can continue right okay so +what does that mean this means that if I + + align:start position:0% +what does that mean this means that if I + + + align:start position:0% +what does that mean this means that if I +evaluate clsi are at X equal to 0 sy 0 Y + + align:start position:0% +evaluate clsi are at X equal to 0 sy 0 Y + + + align:start position:0% +evaluate clsi are at X equal to 0 sy 0 Y +T okay the left hand side will be equal + + align:start position:0% +T okay the left hand side will be equal + + + align:start position:0% +T okay the left hand side will be equal +to a exponential I K Y times y minus + + align:start position:0% +to a exponential I K Y times y minus + + + align:start position:0% +to a exponential I K Y times y minus +Omega P plus summing over all possible + + align:start position:0% +Omega P plus summing over all possible + + + align:start position:0% +Omega P plus summing over all possible +alpha R alpha a exponential I K Y K + + align:start position:0% +alpha R alpha a exponential I K Y K + + + align:start position:0% +alpha R alpha a exponential I K Y K +alpha Y times y minus Omega okay this is + + align:start position:0% +alpha Y times y minus Omega okay this is + + + align:start position:0% +alpha Y times y minus Omega okay this is +the incident wave transmitted wet + + align:start position:0% +the incident wave transmitted wet + + + align:start position:0% +the incident wave transmitted wet +evaluated at the left hand side which is + + align:start position:0% +evaluated at the left hand side which is + + + align:start position:0% +evaluated at the left hand side which is +the upper popular and that would be + + align:start position:0% +the upper popular and that would be + + + align:start position:0% +the upper popular and that would be +equal to the right hand side which is a + + align:start position:0% +equal to the right hand side which is a + + + align:start position:0% +equal to the right hand side which is a +shaded containing only the transmitted + + align:start position:0% +shaded containing only the transmitted + + + align:start position:0% +shaded containing only the transmitted +wave so + + align:start position:0% +wave so + + + align:start position:0% +wave so +basically you have summing over beta 2 + + align:start position:0% +basically you have summing over beta 2 + + + align:start position:0% +basically you have summing over beta 2 +beta a exponential I K beta Y times R + + align:start position:0% +beta a exponential I K beta Y times R + + + align:start position:0% +beta a exponential I K beta Y times R +minus Omega T and this this is + + align:start position:0% +minus Omega T and this this is + + + align:start position:0% +minus Omega T and this this is +expression this boundary condition + + align:start position:0% +expression this boundary condition + + + align:start position:0% +expression this boundary condition +should hold true for the other possible + + align:start position:0% +should hold true for the other possible + + + align:start position:0% +should hold true for the other possible +Y right because the boundary condition + + align:start position:0% +Y right because the boundary condition + + + align:start position:0% +Y right because the boundary condition +is bad it at X equal to 0 I didn't + + align:start position:0% +is bad it at X equal to 0 I didn't + + + align:start position:0% +is bad it at X equal to 0 I didn't +specify the value of Y right so + + align:start position:0% +specify the value of Y right so + + + align:start position:0% +specify the value of Y right so +therefore I can actually put in all the + + align:start position:0% +therefore I can actually put in all the + + + align:start position:0% +therefore I can actually put in all the +possible oh this should be Y sorry for + + align:start position:0% +possible oh this should be Y sorry for + + + align:start position:0% +possible oh this should be Y sorry for +that I can actually vary the Y okay and + + align:start position:0% +that I can actually vary the Y okay and + + + align:start position:0% +that I can actually vary the Y okay and +I will figure out that huh if I have K Y + + align:start position:0% +I will figure out that huh if I have K Y + + + align:start position:0% +I will figure out that huh if I have K Y +it's not equal to k FR y that means the + + align:start position:0% +it's not equal to k FR y that means the + + + align:start position:0% +it's not equal to k FR y that means the +wavelength of the refractive wave and + + align:start position:0% +wavelength of the refractive wave and + + + align:start position:0% +wavelength of the refractive wave and +the incident wave will be different if I + + align:start position:0% +the incident wave will be different if I + + + align:start position:0% +the incident wave will be different if I +have K Y not equal to beta Y that means + + align:start position:0% +have K Y not equal to beta Y that means + + + align:start position:0% +have K Y not equal to beta Y that means +the transmitted wave wave Lance is going + + align:start position:0% +the transmitted wave wave Lance is going + + + align:start position:0% +the transmitted wave wave Lance is going +to be different from the incident wave + + align:start position:0% +to be different from the incident wave + + + align:start position:0% +to be different from the incident wave +that means no matter what I do as a + + align:start position:0% +that means no matter what I do as a + + + align:start position:0% +that means no matter what I do as a +function of Y the membranes will break + + align:start position:0% +function of Y the membranes will break + + + align:start position:0% +function of Y the membranes will break +right therefore in order to make this + + align:start position:0% +right therefore in order to make this + + + align:start position:0% +right therefore in order to make this +equation that it the only choice is that + + align:start position:0% +equation that it the only choice is that + + + align:start position:0% +equation that it the only choice is that +when K alpha Y would be equal to K beta + + align:start position:0% +when K alpha Y would be equal to K beta + + + align:start position:0% +when K alpha Y would be equal to K beta +Y and equal to K Y so that means the + + align:start position:0% +Y and equal to K Y so that means the + + + align:start position:0% +Y and equal to K Y so that means the +wavelength + + align:start position:0% +wavelength + + + align:start position:0% +wavelength +okay projected in the Y direction should + + align:start position:0% +okay projected in the Y direction should + + + align:start position:0% +okay projected in the Y direction should +be equal for the incident wave + + align:start position:0% +be equal for the incident wave + + + align:start position:0% +be equal for the incident wave +transmitted wave and refractive ways + + align:start position:0% +transmitted wave and refractive ways + + + align:start position:0% +transmitted wave and refractive ways +otherwise you can as you always move a + + align:start position:0% +otherwise you can as you always move a + + + align:start position:0% +otherwise you can as you always move a +little bit in the Y direction and the + + align:start position:0% +little bit in the Y direction and the + + + align:start position:0% +little bit in the Y direction and the +membranes were break okay so that's + + align:start position:0% +membranes were break okay so that's + + + align:start position:0% +membranes were break okay so that's +actually the condition which you can + + align:start position:0% +actually the condition which you can + + + align:start position:0% +actually the condition which you can +actually get and the interesting see is + + align:start position:0% +actually get and the interesting see is + + + align:start position:0% +actually get and the interesting see is +that okay based on this expression K F + + align:start position:0% +that okay based on this expression K F + + + align:start position:0% +that okay based on this expression K F +as the length of the k alpha and the + + align:start position:0% +as the length of the k alpha and the + + + align:start position:0% +as the length of the k alpha and the +length of the K beta is fixed right and + + align:start position:0% +length of the K beta is fixed right and + + + align:start position:0% +length of the K beta is fixed right and +I also know will be the component for + + align:start position:0% +I also know will be the component for + + + align:start position:0% +I also know will be the component for +the + + align:start position:0% +the + + + align:start position:0% +the +direction therefore that means the X + + align:start position:0% +direction therefore that means the X + + + align:start position:0% +direction therefore that means the X +direction and the X direction size for + + align:start position:0% +direction and the X direction size for + + + align:start position:0% +direction and the X direction size for +the K Alpha X and the K Y K beta X also + + align:start position:0% +the K Alpha X and the K Y K beta X also + + + align:start position:0% +the K Alpha X and the K Y K beta X also +fixed because of the dispersion relation + + align:start position:0% +fixed because of the dispersion relation + + + align:start position:0% +fixed because of the dispersion relation +okay so so that immediately bring me to + + align:start position:0% +okay so so that immediately bring me to + + + align:start position:0% +okay so so that immediately bring me to +this conclusion that basically K Alpha X + + align:start position:0% +this conclusion that basically K Alpha X + + + align:start position:0% +this conclusion that basically K Alpha X +will be equal to minus Omega square over + + align:start position:0% +will be equal to minus Omega square over + + + align:start position:0% +will be equal to minus Omega square over +V squared minus KY squared and that + + align:start position:0% +V squared minus KY squared and that + + + align:start position:0% +V squared minus KY squared and that +would be equal to minus KX okay so this + + align:start position:0% +would be equal to minus KX okay so this + + + align:start position:0% +would be equal to minus KX okay so this +is with the X component of the + + align:start position:0% +is with the X component of the + + + align:start position:0% +is with the X component of the +refractive wave and the transmitted wave + + align:start position:0% +refractive wave and the transmitted wave + + + align:start position:0% +refractive wave and the transmitted wave +K beta X will be equal to square root of + + align:start position:0% +K beta X will be equal to square root of + + + align:start position:0% +K beta X will be equal to square root of +Omega square over V squared minus KY + + align:start position:0% +Omega square over V squared minus KY + + + align:start position:0% +Omega square over V squared minus KY +square if I draw visualize the relative + + align:start position:0% +square if I draw visualize the relative + + + align:start position:0% +square if I draw visualize the relative +direction of all the three components + + align:start position:0% +direction of all the three components + + + align:start position:0% +direction of all the three components +basically this is actually the direction + + align:start position:0% +basically this is actually the direction + + + align:start position:0% +basically this is actually the direction +of the incident wave okay and the + + align:start position:0% +of the incident wave okay and the + + + align:start position:0% +of the incident wave okay and the +inserting angle is Sita and from this + + align:start position:0% +inserting angle is Sita and from this + + + align:start position:0% +inserting angle is Sita and from this +expression you see that the K Y is equal + + align:start position:0% +expression you see that the K Y is equal + + + align:start position:0% +expression you see that the K Y is equal +to K alpha Y therefore you have a + + align:start position:0% +to K alpha Y therefore you have a + + + align:start position:0% +to K alpha Y therefore you have a +refractive wave but actually only the x + + align:start position:0% +refractive wave but actually only the x + + + align:start position:0% +refractive wave but actually only the x +direction is change sign therefore you + + align:start position:0% +direction is change sign therefore you + + + align:start position:0% +direction is change sign therefore you +have a refractive wave with exactly the + + align:start position:0% +have a refractive wave with exactly the + + + align:start position:0% +have a refractive wave with exactly the +same angle as the in certain angle + + align:start position:0% +same angle as the in certain angle + + + align:start position:0% +same angle as the in certain angle +incident angle theta the reflected the + + align:start position:0% +incident angle theta the reflected the + + + align:start position:0% +incident angle theta the reflected the +refraction angle will be Sita as well + + align:start position:0% +refraction angle will be Sita as well + + + align:start position:0% +refraction angle will be Sita as well +and there will be a transmitted wave + + align:start position:0% +and there will be a transmitted wave + + + align:start position:0% +and there will be a transmitted wave +with Sita prom and this is issued at the + + align:start position:0% +with Sita prom and this is issued at the + + + align:start position:0% +with Sita prom and this is issued at the +ration of the k k prom and the + + align:start position:0% +ration of the k k prom and the + + + align:start position:0% +ration of the k k prom and the +interesting see is that the projection + + align:start position:0% +interesting see is that the projection + + + align:start position:0% +interesting see is that the projection +to the to the y direction the K prime Y + + align:start position:0% +to the to the y direction the K prime Y + + + align:start position:0% +to the to the y direction the K prime Y +has to be equal to the projection of the + + align:start position:0% +has to be equal to the projection of the + + + align:start position:0% +has to be equal to the projection of the +original incident wave in the in the Y + + align:start position:0% +original incident wave in the in the Y + + + align:start position:0% +original incident wave in the in the Y +direction + + align:start position:0% +direction + + + align:start position:0% +direction +okay so that means I will be able to + + align:start position:0% +okay so that means I will be able to + + + align:start position:0% +okay so that means I will be able to +conclude that okay the Y components are + + align:start position:0% +conclude that okay the Y components are + + + align:start position:0% +conclude that okay the Y components are +the same therefore I can conclude + + align:start position:0% +the same therefore I can conclude + + + align:start position:0% +the same therefore I can conclude +that K sine theta will be equal to K + + align:start position:0% +that K sine theta will be equal to K + + + align:start position:0% +that K sine theta will be equal to K +prang sine theta prime okay and kind of + + align:start position:0% +prang sine theta prime okay and kind of + + + align:start position:0% +prang sine theta prime okay and kind of +running out of time and if I define + + align:start position:0% +running out of time and if I define + + + align:start position:0% +running out of time and if I define +already as I define here velocity is + + align:start position:0% +already as I define here velocity is + + + align:start position:0% +already as I define here velocity is +equal to C over N and the V prime is + + align:start position:0% +equal to C over N and the V prime is + + + align:start position:0% +equal to C over N and the V prime is +equal to C over m pant okay what I can + + align:start position:0% +equal to C over m pant okay what I can + + + align:start position:0% +equal to C over m pant okay what I can +actually immediately conclude is that + + align:start position:0% +actually immediately conclude is that + + + align:start position:0% +actually immediately conclude is that +give me one more minute is that if I + + align:start position:0% +give me one more minute is that if I + + + align:start position:0% +give me one more minute is that if I +have an equal to C over V and the Empire + + align:start position:0% +have an equal to C over V and the Empire + + + align:start position:0% +have an equal to C over V and the Empire +is equal to C over B front I can + + align:start position:0% +is equal to C over B front I can + + + align:start position:0% +is equal to C over B front I can +conclude that n sine theta will be equal + + align:start position:0% +conclude that n sine theta will be equal + + + align:start position:0% +conclude that n sine theta will be equal +to L prime sine theta Prime does this + + align:start position:0% +to L prime sine theta Prime does this + + + align:start position:0% +to L prime sine theta Prime does this +look familiar to you + + align:start position:0% +look familiar to you + + + align:start position:0% +look familiar to you +this is actually Snell's law right how + + align:start position:0% +this is actually Snell's law right how + + + align:start position:0% +this is actually Snell's law right how +many of you haven't heard about Snell's + + align:start position:0% +many of you haven't heard about Snell's + + + align:start position:0% +many of you haven't heard about Snell's +law there were a few before yeah okay no + + align:start position:0% +law there were a few before yeah okay no + + + align:start position:0% +law there were a few before yeah okay no +problem at all then you learned it right + + align:start position:0% +problem at all then you learned it right + + + align:start position:0% +problem at all then you learned it right +so that means if I have two kinds of + + align:start position:0% +so that means if I have two kinds of + + + align:start position:0% +so that means if I have two kinds of +systems in my hand and I will be able to + + align:start position:0% +systems in my hand and I will be able to + + + align:start position:0% +systems in my hand and I will be able to +relate the the transmitted wave and + + align:start position:0% +relate the the transmitted wave and + + + align:start position:0% +relate the the transmitted wave and +according to what I have in the incident + + align:start position:0% +according to what I have in the incident + + + align:start position:0% +according to what I have in the incident +wave and you can see that Snell's law + + align:start position:0% +wave and you can see that Snell's law + + + align:start position:0% +wave and you can see that Snell's law +which were famous for optics right the + + align:start position:0% +which were famous for optics right the + + + align:start position:0% +which were famous for optics right the +discussion of optics and here I have no + + align:start position:0% +discussion of optics and here I have no + + + align:start position:0% +discussion of optics and here I have no +knowledge about optics or + + align:start position:0% +knowledge about optics or + + + align:start position:0% +knowledge about optics or +electromagnetic wave so in short what I + + align:start position:0% +electromagnetic wave so in short what I + + + align:start position:0% +electromagnetic wave so in short what I +want to tell you is that we have just + + align:start position:0% +want to tell you is that we have just + + + align:start position:0% +want to tell you is that we have just +proved two of the most important laws of + + align:start position:0% +proved two of the most important laws of + + + align:start position:0% +proved two of the most important laws of +the geometrical optics the refraction + + align:start position:0% +the geometrical optics the refraction + + + align:start position:0% +the geometrical optics the refraction +angle is equal to either the angle and + + align:start position:0% +angle is equal to either the angle and + + + align:start position:0% +angle is equal to either the angle and +the Snell's law without using any + + align:start position:0% +the Snell's law without using any + + + align:start position:0% +the Snell's law without using any +information about the dynamics that + + align:start position:0% +information about the dynamics that + + + align:start position:0% +information about the dynamics that +means all those laws are coming from + + align:start position:0% +means all those laws are coming from + + + align:start position:0% +means all those laws are coming from +pure the boundary condition and the + + align:start position:0% +pure the boundary condition and the + + + align:start position:0% +pure the boundary condition and the +waves therefore you will expect that + + align:start position:0% +waves therefore you will expect that + + + align:start position:0% +waves therefore you will expect that +this will work for water wave some wave + + align:start position:0% +this will work for water wave some wave + + + align:start position:0% +this will work for water wave some wave +electromagnetic wave etc okay so we will + + align:start position:0% +electromagnetic wave etc okay so we will + + + align:start position:0% +electromagnetic wave etc okay so we will +continue the discussion + + align:start position:0% +continue the discussion + + + align:start position:0% +continue the discussion +science thanks for the attention and if + + align:start position:0% +science thanks for the attention and if + + + align:start position:0% +science thanks for the attention and if +I have any questions let me know I will + + align:start position:0% +I have any questions let me know I will + + + align:start position:0% +I have any questions let me know I will +be here + + align:start position:0% + + + + align:start position:0% + +hello everybody we are going to show you + + align:start position:0% +hello everybody we are going to show you + + + align:start position:0% +hello everybody we are going to show you +a demonstration really nice one + + align:start position:0% +a demonstration really nice one + + + align:start position:0% +a demonstration really nice one +though I is a consist of following setup + + align:start position:0% +though I is a consist of following setup + + + align:start position:0% +though I is a consist of following setup +so basically I'm going to press soft + + align:start position:0% +so basically I'm going to press soft + + + align:start position:0% +so basically I'm going to press soft +film here and then behind that is a + + align:start position:0% +film here and then behind that is a + + + align:start position:0% +film here and then behind that is a +loudspeaker which I use a signal + + align:start position:0% +loudspeaker which I use a signal + + + align:start position:0% +loudspeaker which I use a signal +generator and to actually produce some + + align:start position:0% +generator and to actually produce some + + + align:start position:0% +generator and to actually produce some +wave and this song wave is going to + + align:start position:0% +wave and this song wave is going to + + + align:start position:0% +wave and this song wave is going to +oscillate the soft film and then you are + + align:start position:0% +oscillate the soft film and then you are + + + align:start position:0% +oscillate the soft film and then you are +going to see the oscillation were saying + + align:start position:0% +going to see the oscillation were saying + + + align:start position:0% +going to see the oscillation were saying +no more moved pattern on the screen ok + + align:start position:0% +no more moved pattern on the screen ok + + + align:start position:0% +no more moved pattern on the screen ok +so that that is actually the setup which + + align:start position:0% +so that that is actually the setup which + + + align:start position:0% +so that that is actually the setup which +we can actually demonstrate new to time + + align:start position:0% +we can actually demonstrate new to time + + + align:start position:0% +we can actually demonstrate new to time +mentioned no normal modes so the first + + align:start position:0% +mentioned no normal modes so the first + + + align:start position:0% +mentioned no normal modes so the first +thing which I am going to do is to + + align:start position:0% +thing which I am going to do is to + + + align:start position:0% +thing which I am going to do is to +produce a soft film now I'm going to put + + align:start position:0% +produce a soft film now I'm going to put + + + align:start position:0% +produce a soft film now I'm going to put +it back into this setup here you should + + align:start position:0% +it back into this setup here you should + + + align:start position:0% +it back into this setup here you should +be able to see the pattern on the screen + + align:start position:0% + + + + align:start position:0% + +then I'm going to turn on the some wave + + align:start position:0% +then I'm going to turn on the some wave + + + align:start position:0% +then I'm going to turn on the some wave +generator you can see immediately that + + align:start position:0% +generator you can see immediately that + + + align:start position:0% +generator you can see immediately that +the pattern is on the screen changed + + align:start position:0% +the pattern is on the screen changed + + + align:start position:0% +the pattern is on the screen changed +because of the song wave trying to + + align:start position:0% +because of the song wave trying to + + + align:start position:0% +because of the song wave trying to +assert a self UHN you can actually see + + align:start position:0% +assert a self UHN you can actually see + + + align:start position:0% +assert a self UHN you can actually see +it directly from here but the + + align:start position:0% +it directly from here but the + + + align:start position:0% +it directly from here but the +essentially looks a much more prominent + + align:start position:0% +essentially looks a much more prominent + + + align:start position:0% +essentially looks a much more prominent +on the screen and now what I'm going to + + align:start position:0% +on the screen and now what I'm going to + + + align:start position:0% +on the screen and now what I'm going to +do is to change the the frequency of the + + align:start position:0% +do is to change the the frequency of the + + + align:start position:0% +do is to change the the frequency of the +sound wave and you can see that now I'm + + align:start position:0% +sound wave and you can see that now I'm + + + align:start position:0% +sound wave and you can see that now I'm +changing it to a higher frequency and + + align:start position:0% +changing it to a higher frequency and + + + align:start position:0% +changing it to a higher frequency and +you can see that there are more + + align:start position:0% +you can see that there are more + + + align:start position:0% +you can see that there are more +complicated pattern form on the screen + + align:start position:0% +complicated pattern form on the screen + + + align:start position:0% +complicated pattern form on the screen +that is because I now exciteing higher + + align:start position:0% +that is because I now exciteing higher + + + align:start position:0% +that is because I now exciteing higher +and higher frequency normal mode + + align:start position:0% + + + + align:start position:0% + +and you can see that now as you continue + + align:start position:0% +and you can see that now as you continue + + + align:start position:0% +and you can see that now as you continue +in the increased increased the frequency + + align:start position:0% +in the increased increased the frequency + + + align:start position:0% +in the increased increased the frequency +and you can see that now we can see that + + align:start position:0% +and you can see that now we can see that + + + align:start position:0% +and you can see that now we can see that +the pattern become really really + + align:start position:0% +the pattern become really really + + + align:start position:0% +the pattern become really really +infinitely complicated you can see this + + align:start position:0% +infinitely complicated you can see this + + + align:start position:0% +infinitely complicated you can see this +grid developing and you can see that + + align:start position:0% +grid developing and you can see that + + + align:start position:0% +grid developing and you can see that +basically that's two basically two sine + + align:start position:0% +basically that's two basically two sine + + + align:start position:0% +basically that's two basically two sine +function multiplied each other one is + + align:start position:0% +function multiplied each other one is + + + align:start position:0% +function multiplied each other one is +one sine functions in the x-direction + + align:start position:0% +one sine functions in the x-direction + + + align:start position:0% +one sine functions in the x-direction +the other one is in the Y Direction + + align:start position:0% +the other one is in the Y Direction + + + align:start position:0% +the other one is in the Y Direction +horizontal and the vertical direction + + align:start position:0% +horizontal and the vertical direction + + + align:start position:0% +horizontal and the vertical direction +and you can see really beautiful pattern + + align:start position:0% +and you can see really beautiful pattern + + + align:start position:0% +and you can see really beautiful pattern +forming due to the new to this solution + + align:start position:0% +forming due to the new to this solution + + + align:start position:0% +forming due to the new to this solution +wind arrived during the lecture and the + + align:start position:0% +wind arrived during the lecture and the + + + align:start position:0% +wind arrived during the lecture and the +higher frequency I go I can see more + + align:start position:0% +higher frequency I go I can see more + + + align:start position:0% +higher frequency I go I can see more +complicated pattern or many more lines + + align:start position:0% +complicated pattern or many more lines + + + align:start position:0% +complicated pattern or many more lines +developing under screen + + align:start position:0% +developing under screen + + + align:start position:0% +developing under screen +due to the oscillation of the soap film + + align:start position:0% +due to the oscillation of the soap film + + + align:start position:0% +due to the oscillation of the soap film +you can see now we have even more lines + + align:start position:0% + + + + align:start position:0% + +and this is you getting more more + + align:start position:0% +and this is you getting more more + + + align:start position:0% +and this is you getting more more +difficult to see the pattern because now + + align:start position:0% +difficult to see the pattern because now + + + align:start position:0% +difficult to see the pattern because now +the lines are pretty close to each other + + align:start position:0% +the lines are pretty close to each other + + + align:start position:0% +the lines are pretty close to each other +the Northern Line we can see clear the + + align:start position:0% +the Northern Line we can see clear the + + + align:start position:0% +the Northern Line we can see clear the +other screen + + align:start position:0% + + + + align:start position:0% + +I'm going back down to a lower frequency + + align:start position:0% +I'm going back down to a lower frequency + + + align:start position:0% +I'm going back down to a lower frequency +and you can see that a new frequency + + align:start position:0% +and you can see that a new frequency + + + align:start position:0% +and you can see that a new frequency +oscillation the number of lines is a + + align:start position:0% +oscillation the number of lines is a + + + align:start position:0% +oscillation the number of lines is a +should be smaller and and that is + + align:start position:0% +should be smaller and and that is + + + align:start position:0% +should be smaller and and that is +because of the smoother oscillation + + align:start position:0% +because of the smoother oscillation + + + align:start position:0% +because of the smoother oscillation +frequency and the longer wavelength of + + align:start position:0% +frequency and the longer wavelength of + + + align:start position:0% +frequency and the longer wavelength of +the normal modes + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/aPdgRxcP2lA.txt b/aPdgRxcP2lA.txt new file mode 100644 index 0000000000000000000000000000000000000000..77e1fc1c2433306ee8efac6e1576ad552c338bcc --- /dev/null +++ b/aPdgRxcP2lA.txt @@ -0,0 +1,5115 @@ +align:start position:0% + +foreign + + align:start position:0% + + + + align:start position:0% + +I'm a professor at MIT in the department + + align:start position:0% +I'm a professor at MIT in the department + + + align:start position:0% +I'm a professor at MIT in the department +of urban studies and planning I'd like + + align:start position:0% +of urban studies and planning I'd like + + + align:start position:0% +of urban studies and planning I'd like +to welcome you to another lecture in my + + align:start position:0% +to welcome you to another lecture in my + + + align:start position:0% +to welcome you to another lecture in my +series on Urban Energy Systems and + + align:start position:0% +series on Urban Energy Systems and + + + align:start position:0% +series on Urban Energy Systems and +policy + + align:start position:0% +policy + + + align:start position:0% +policy +today we're going to talk about cities + + align:start position:0% +today we're going to talk about cities + + + align:start position:0% +today we're going to talk about cities +and Industrial admissions + + align:start position:0% +and Industrial admissions + + + align:start position:0% +and Industrial admissions +and what I want to do in this class in + + align:start position:0% +and what I want to do in this class in + + + align:start position:0% +and what I want to do in this class in +this lecture is connect cities to the + + align:start position:0% +this lecture is connect cities to the + + + align:start position:0% +this lecture is connect cities to the +larger issues of Investments + + align:start position:0% +larger issues of Investments + + + align:start position:0% +larger issues of Investments +early because inductible missions don't + + align:start position:0% +early because inductible missions don't + + + align:start position:0% +early because inductible missions don't +always seem to be very present in the + + align:start position:0% +always seem to be very present in the + + + align:start position:0% +always seem to be very present in the +cities so I don't seem to connect to + + align:start position:0% +cities so I don't seem to connect to + + + align:start position:0% +cities so I don't seem to connect to +cities as centers of consumption as I've + + align:start position:0% +cities as centers of consumption as I've + + + align:start position:0% +cities as centers of consumption as I've +been talking to you about in this + + align:start position:0% +been talking to you about in this + + + align:start position:0% +been talking to you about in this +lecture series but also because + + align:start position:0% +lecture series but also because + + + align:start position:0% +lecture series but also because +industrial admissions are a considered + + align:start position:0% +industrial admissions are a considered + + + align:start position:0% +industrial admissions are a considered +an extremely tough to decarbonize sector + + align:start position:0% +an extremely tough to decarbonize sector + + + align:start position:0% +an extremely tough to decarbonize sector +we have to replace the electricity but + + align:start position:0% +we have to replace the electricity but + + + align:start position:0% +we have to replace the electricity but +also quickly the Heat and the materials + + align:start position:0% +also quickly the Heat and the materials + + + align:start position:0% +also quickly the Heat and the materials +we use in ductile systems to reduce our + + align:start position:0% +we use in ductile systems to reduce our + + + align:start position:0% +we use in ductile systems to reduce our +greenhouse gas emissions that doesn't + + align:start position:0% +greenhouse gas emissions that doesn't + + + align:start position:0% +greenhouse gas emissions that doesn't +always seem to be a area or a scale at + + align:start position:0% +always seem to be a area or a scale at + + + align:start position:0% +always seem to be a area or a scale at +which cities can affect this kinds of + + align:start position:0% +which cities can affect this kinds of + + + align:start position:0% +which cities can affect this kinds of +policy but we'll explore that today in + + align:start position:0% +policy but we'll explore that today in + + + align:start position:0% +policy but we'll explore that today in +this lecture how cities can affect or + + align:start position:0% +this lecture how cities can affect or + + + align:start position:0% +this lecture how cities can affect or +reduce their industrial emissions + + align:start position:0% +reduce their industrial emissions + + + align:start position:0% +reduce their industrial emissions +the materials would say are all on the + + align:start position:0% +the materials would say are all on the + + + align:start position:0% +the materials would say are all on the +syllabus if you have the PDFs then + + align:start position:0% +syllabus if you have the PDFs then + + + align:start position:0% +syllabus if you have the PDFs then +please go ahead and you can link to + + align:start position:0% +please go ahead and you can link to + + + align:start position:0% +please go ahead and you can link to +these materials to read them before the + + align:start position:0% +these materials to read them before the + + + align:start position:0% +these materials to read them before the +lecture the lecture will build on these + + align:start position:0% +lecture the lecture will build on these + + + align:start position:0% +lecture the lecture will build on these +materials + + align:start position:0% +materials + + + align:start position:0% +materials +and the themes on it uh focus on today + + align:start position:0% +and the themes on it uh focus on today + + + align:start position:0% +and the themes on it uh focus on today +are consumption as a mechanism of being + + align:start position:0% +are consumption as a mechanism of being + + + align:start position:0% +are consumption as a mechanism of being +asked gas emissions that's something + + align:start position:0% +asked gas emissions that's something + + + align:start position:0% +asked gas emissions that's something +I've said to you before in previous + + align:start position:0% +I've said to you before in previous + + + align:start position:0% +I've said to you before in previous +lectures + + align:start position:0% +lectures + + + align:start position:0% +lectures +I want to emphasized consumption is a + + align:start position:0% +I want to emphasized consumption is a + + + align:start position:0% +I want to emphasized consumption is a +connection to larger Energy Systems I + + align:start position:0% +connection to larger Energy Systems I + + + align:start position:0% +connection to larger Energy Systems I +think I've said to you also in previous + + align:start position:0% +think I've said to you also in previous + + + align:start position:0% +think I've said to you also in previous +lectures how we often focus on changing + + align:start position:0% +lectures how we often focus on changing + + + align:start position:0% +lectures how we often focus on changing +the Energy System how energy is produced + + align:start position:0% +the Energy System how energy is produced + + + align:start position:0% +the Energy System how energy is produced +how it is transmitted but not always + + align:start position:0% +how it is transmitted but not always + + + align:start position:0% +how it is transmitted but not always +thinking about how we can change how + + align:start position:0% +thinking about how we can change how + + + align:start position:0% +thinking about how we can change how +energy is consumed + + align:start position:0% +energy is consumed + + + align:start position:0% +energy is consumed +I'll also argue to you in today's luck + + align:start position:0% +I'll also argue to you in today's luck + + + align:start position:0% +I'll also argue to you in today's luck +through that industrial missions have + + align:start position:0% +through that industrial missions have + + + align:start position:0% +through that industrial missions have +strong very strong environmental justice + + align:start position:0% +strong very strong environmental justice + + + align:start position:0% +strong very strong environmental justice +implications + + align:start position:0% +implications + + + align:start position:0% +implications +it also is perhaps connected to our + + align:start position:0% +it also is perhaps connected to our + + + align:start position:0% +it also is perhaps connected to our +Urban rural Regional and political + + align:start position:0% +Urban rural Regional and political + + + align:start position:0% +Urban rural Regional and political +polarization over climate action + + align:start position:0% +polarization over climate action + + + align:start position:0% +polarization over climate action +and then we'll finish today and in class + + align:start position:0% +and then we'll finish today and in class + + + align:start position:0% +and then we'll finish today and in class +discussion thinking about how we might + + align:start position:0% +discussion thinking about how we might + + + align:start position:0% +discussion thinking about how we might +transform the seductible system both + + align:start position:0% +transform the seductible system both + + + align:start position:0% +transform the seductible system both +within cities and from cities also + + align:start position:0% +within cities and from cities also + + + align:start position:0% +within cities and from cities also +and so if we just start with my eyes + + align:start position:0% +and so if we just start with my eyes + + + align:start position:0% +and so if we just start with my eyes +calculation in chapter 15. he talks + + align:start position:0% +calculation in chapter 15. he talks + + + align:start position:0% +calculation in chapter 15. he talks +about life cycle analysis talks about + + align:start position:0% +about life cycle analysis talks about + + + align:start position:0% +about life cycle analysis talks about +the energy or sustainable energy + + align:start position:0% +the energy or sustainable energy + + + align:start position:0% +the energy or sustainable energy +required to produce raw materials + + align:start position:0% +required to produce raw materials + + + align:start position:0% +required to produce raw materials +uh to sorry obtain raw materials how do + + align:start position:0% +uh to sorry obtain raw materials how do + + + align:start position:0% +uh to sorry obtain raw materials how do +we produce finished goods out of the raw + + align:start position:0% +we produce finished goods out of the raw + + + align:start position:0% +we produce finished goods out of the raw +materials how do we use those materials + + align:start position:0% +materials how do we use those materials + + + align:start position:0% +materials how do we use those materials +acquiring energy and ultimately how do + + align:start position:0% +acquiring energy and ultimately how do + + + align:start position:0% +acquiring energy and ultimately how do +we dispose or uh get rid of materials + + align:start position:0% +we dispose or uh get rid of materials + + + align:start position:0% +we dispose or uh get rid of materials +by calling it waste something we talked + + align:start position:0% +by calling it waste something we talked + + + align:start position:0% +by calling it waste something we talked +about in the last lecture on Energy + + align:start position:0% +about in the last lecture on Energy + + + align:start position:0% +about in the last lecture on Energy +Efficiency + + align:start position:0% +Efficiency + + + align:start position:0% +Efficiency +and the materials he goes to briefly in + + align:start position:0% +and the materials he goes to briefly in + + + align:start position:0% +and the materials he goes to briefly in +chapter 15 are the production of raw + + align:start position:0% +chapter 15 are the production of raw + + + align:start position:0% +chapter 15 are the production of raw +materials like aluminum or steel + + align:start position:0% +materials like aluminum or steel + + + align:start position:0% +materials like aluminum or steel +packaging chips semiconductors paper + + align:start position:0% +packaging chips semiconductors paper + + + align:start position:0% +packaging chips semiconductors paper +building construction and Roads + + align:start position:0% +building construction and Roads + + + align:start position:0% +building construction and Roads +automaking and of course Makai makes the + + align:start position:0% +automaking and of course Makai makes the + + + align:start position:0% +automaking and of course Makai makes the +point that a lot of things aren't + + align:start position:0% +point that a lot of things aren't + + + align:start position:0% +point that a lot of things aren't +necessarily made in the UK anymore + + align:start position:0% +necessarily made in the UK anymore + + + align:start position:0% +necessarily made in the UK anymore +they're quite often imported so that is + + align:start position:0% +they're quite often imported so that is + + + align:start position:0% +they're quite often imported so that is +embodied energy in the form of materials + + align:start position:0% +embodied energy in the form of materials + + + align:start position:0% +embodied energy in the form of materials +and goods being brought into the UK and + + align:start position:0% +and goods being brought into the UK and + + + align:start position:0% +and goods being brought into the UK and +surprisingly if we look at his Stacks we + + align:start position:0% +surprisingly if we look at his Stacks we + + + align:start position:0% +surprisingly if we look at his Stacks we +haven't visited Revisited this concept + + align:start position:0% +haven't visited Revisited this concept + + + align:start position:0% +haven't visited Revisited this concept +for a while if you look at all the + + align:start position:0% +for a while if you look at all the + + + align:start position:0% +for a while if you look at all the +previous chapters we've talked about + + align:start position:0% +previous chapters we've talked about + + + align:start position:0% +previous chapters we've talked about +Heating and Cooling and deaf lights and + + align:start position:0% +Heating and Cooling and deaf lights and + + + align:start position:0% +Heating and Cooling and deaf lights and +cars stuff and the transporting of stuff + + align:start position:0% +cars stuff and the transporting of stuff + + + align:start position:0% +cars stuff and the transporting of stuff +is the largest category so far and so + + align:start position:0% +is the largest category so far and so + + + align:start position:0% +is the largest category so far and so +far by chapter 15 is tipping us over + + align:start position:0% +far by chapter 15 is tipping us over + + + align:start position:0% +far by chapter 15 is tipping us over +into more consumption than we can + + align:start position:0% +into more consumption than we can + + + align:start position:0% +into more consumption than we can +produce from sustainable energy + + align:start position:0% +produce from sustainable energy + + + align:start position:0% +produce from sustainable energy +resources on the right + + align:start position:0% +resources on the right + + + align:start position:0% +resources on the right +if we just think about uh some of these + + align:start position:0% +if we just think about uh some of these + + + align:start position:0% +if we just think about uh some of these +energy uses on the same footing uh the + + align:start position:0% +energy uses on the same footing uh the + + + align:start position:0% +energy uses on the same footing uh the +stuff per person then with eye + + align:start position:0% +stuff per person then with eye + + + align:start position:0% +stuff per person then with eye +calculates in appendix agents around 41 + + align:start position:0% +calculates in appendix agents around 41 + + + align:start position:0% +calculates in appendix agents around 41 +kilowatt hours per day that's 41 + + align:start position:0% +kilowatt hours per day that's 41 + + + align:start position:0% +kilowatt hours per day that's 41 +kilowatt hours per day as kind of a rate + + align:start position:0% +kilowatt hours per day as kind of a rate + + + align:start position:0% +kilowatt hours per day as kind of a rate +of energy use + + align:start position:0% +of energy use + + + align:start position:0% +of energy use +hot water hot air and cooling add up to + + align:start position:0% +hot water hot air and cooling add up to + + + align:start position:0% +hot water hot air and cooling add up to +roughly about 37 kilowatt hours per day + + align:start position:0% +roughly about 37 kilowatt hours per day + + + align:start position:0% +roughly about 37 kilowatt hours per day +and the construction of the house that + + align:start position:0% +and the construction of the house that + + + align:start position:0% +and the construction of the house that +with high estimates uh I think a typical + + align:start position:0% +with high estimates uh I think a typical + + + align:start position:0% +with high estimates uh I think a typical +English house just the shell of the + + align:start position:0% +English house just the shell of the + + + align:start position:0% +English house just the shell of the +house itself is about 42 000 kilowatt + + align:start position:0% +house itself is about 42 000 kilowatt + + + align:start position:0% +house itself is about 42 000 kilowatt +hours over 100 years the house is + + align:start position:0% +hours over 100 years the house is + + + align:start position:0% +hours over 100 years the house is +assumed to last 100 years so if you put + + align:start position:0% +assumed to last 100 years so if you put + + + align:start position:0% +assumed to last 100 years so if you put +that on equal footing it's only 1.2 + + align:start position:0% +that on equal footing it's only 1.2 + + + align:start position:0% +that on equal footing it's only 1.2 +kilowatt hours per day + + align:start position:0% +kilowatt hours per day + + + align:start position:0% +kilowatt hours per day +so we might conclude from these back of + + align:start position:0% +so we might conclude from these back of + + + align:start position:0% +so we might conclude from these back of +the envelope numbers makai's book the + + align:start position:0% +the envelope numbers makai's book the + + + align:start position:0% +the envelope numbers makai's book the +materials and construction aren't really + + align:start position:0% +materials and construction aren't really + + + align:start position:0% +materials and construction aren't really +a problem right + + align:start position:0% +a problem right + + + align:start position:0% +a problem right +well let's just question this for a + + align:start position:0% +well let's just question this for a + + + align:start position:0% +well let's just question this for a +second there's obvious reasons why by + + align:start position:0% +second there's obvious reasons why by + + + align:start position:0% +second there's obvious reasons why by +putting things in the same pudding by + + align:start position:0% +putting things in the same pudding by + + + align:start position:0% +putting things in the same pudding by +kind of amortizing this energy over 100 + + align:start position:0% +kind of amortizing this energy over 100 + + + align:start position:0% +kind of amortizing this energy over 100 +years you might be missing some things + + align:start position:0% +years you might be missing some things + + + align:start position:0% +years you might be missing some things +first the houses that we construct now + + align:start position:0% +first the houses that we construct now + + + align:start position:0% +first the houses that we construct now +in this calculation are assumed to last + + align:start position:0% +in this calculation are assumed to last + + + align:start position:0% +in this calculation are assumed to last +for 100 years not only does that assume + + align:start position:0% +for 100 years not only does that assume + + + align:start position:0% +for 100 years not only does that assume +we don't retrofit or modify them or + + align:start position:0% +we don't retrofit or modify them or + + + align:start position:0% +we don't retrofit or modify them or +redecorate them or demolish them in the + + align:start position:0% +redecorate them or demolish them in the + + + align:start position:0% +redecorate them or demolish them in the +next hundred years which is obviously an + + align:start position:0% +next hundred years which is obviously an + + + align:start position:0% +next hundred years which is obviously an +assumption that probably does not hold + + align:start position:0% +assumption that probably does not hold + + + align:start position:0% +assumption that probably does not hold +in many North American cities let alone + + align:start position:0% +in many North American cities let alone + + + align:start position:0% +in many North American cities let alone +fats developing uh unfreeze + + align:start position:0% +fats developing uh unfreeze + + + align:start position:0% +fats developing uh unfreeze +but also it assumes that the house + + align:start position:0% +but also it assumes that the house + + + align:start position:0% +but also it assumes that the house +construction that we do today is + + align:start position:0% +construction that we do today is + + + align:start position:0% +construction that we do today is +essentially bacon we're locking in that + + align:start position:0% +essentially bacon we're locking in that + + + align:start position:0% +essentially bacon we're locking in that +energy construction now we're locking + + align:start position:0% +energy construction now we're locking + + + align:start position:0% +energy construction now we're locking +the energy implications of that house + + align:start position:0% +the energy implications of that house + + + align:start position:0% +the energy implications of that house +construction now and we're actually + + align:start position:0% +construction now and we're actually + + + align:start position:0% +construction now and we're actually +emitting the carbon emissions of that + + align:start position:0% +emitting the carbon emissions of that + + + align:start position:0% +emitting the carbon emissions of that +now so not only do we calculate this + + align:start position:0% +now so not only do we calculate this + + + align:start position:0% +now so not only do we calculate this +energy basis and kind of average it over + + align:start position:0% +energy basis and kind of average it over + + + align:start position:0% +energy basis and kind of average it over +the next hundred years but it matters + + align:start position:0% +the next hundred years but it matters + + + align:start position:0% +the next hundred years but it matters +much more if we actually do a lot of + + align:start position:0% +much more if we actually do a lot of + + + align:start position:0% +much more if we actually do a lot of +construction and amid a lot of carbon + + align:start position:0% +construction and amid a lot of carbon + + + align:start position:0% +construction and amid a lot of carbon +now much more today than 100 years from + + align:start position:0% +now much more today than 100 years from + + + align:start position:0% +now much more today than 100 years from +now as I've said to you multiple times + + align:start position:0% +now as I've said to you multiple times + + + align:start position:0% +now as I've said to you multiple times +this class we have a mid-century goal of + + align:start position:0% +this class we have a mid-century goal of + + + align:start position:0% +this class we have a mid-century goal of +2015 if we assume that we're going to + + align:start position:0% +2015 if we assume that we're going to + + + align:start position:0% +2015 if we assume that we're going to +stop doing any construction after this + + align:start position:0% +stop doing any construction after this + + + align:start position:0% +stop doing any construction after this +next couple years that might be one + + align:start position:0% +next couple years that might be one + + + align:start position:0% +next couple years that might be one +thing but we still front loaded our uh + + align:start position:0% +thing but we still front loaded our uh + + + align:start position:0% +thing but we still front loaded our uh +energy or our carb emissions today for + + align:start position:0% +energy or our carb emissions today for + + + align:start position:0% +energy or our carb emissions today for +the next 100 years if we make this + + align:start position:0% +the next 100 years if we make this + + + align:start position:0% +the next 100 years if we make this +assumption so perhaps averaging + + align:start position:0% +assumption so perhaps averaging + + + align:start position:0% +assumption so perhaps averaging +everything over the next hundred years + + align:start position:0% +everything over the next hundred years + + + align:start position:0% +everything over the next hundred years +is not the way you should think about it + + align:start position:0% +is not the way you should think about it + + + align:start position:0% +is not the way you should think about it +but another argument I want to make to + + align:start position:0% +but another argument I want to make to + + + align:start position:0% +but another argument I want to make to +you is that there's definitely different + + align:start position:0% +you is that there's definitely different + + + align:start position:0% +you is that there's definitely different +implications of industrial emissions for + + align:start position:0% +implications of industrial emissions for + + + align:start position:0% +implications of industrial emissions for +livelihood and climate action and one of + + align:start position:0% +livelihood and climate action and one of + + + align:start position:0% +livelihood and climate action and one of +the previous lectures I think even the + + align:start position:0% +the previous lectures I think even the + + + align:start position:0% +the previous lectures I think even the +second left period for this class I + + align:start position:0% +second left period for this class I + + + align:start position:0% +second left period for this class I +talked to you about Robert Bullard + + align:start position:0% +talked to you about Robert Bullard + + + align:start position:0% +talked to you about Robert Bullard +Robert Bullard is an article Justin + + align:start position:0% +Robert Bullard is an article Justin + + + align:start position:0% +Robert Bullard is an article Justin +scholar really in some ways the father + + align:start position:0% +scholar really in some ways the father + + + align:start position:0% +scholar really in some ways the father +of a Revival Justice and as I said to + + align:start position:0% +of a Revival Justice and as I said to + + + align:start position:0% +of a Revival Justice and as I said to +you in the second lecture he discovered + + align:start position:0% +you in the second lecture he discovered + + + align:start position:0% +you in the second lecture he discovered +early on in his career as a sociologist + + align:start position:0% +early on in his career as a sociologist + + + align:start position:0% +early on in his career as a sociologist +at 100 of the landfills in Houston were + + align:start position:0% +at 100 of the landfills in Houston were + + + align:start position:0% +at 100 of the landfills in Houston were +located in black neighborhoods though + + align:start position:0% +located in black neighborhoods though + + + align:start position:0% +located in black neighborhoods though +the black population was only 25 percent + + align:start position:0% +the black population was only 25 percent + + + align:start position:0% +the black population was only 25 percent +of Houston's population + + align:start position:0% +of Houston's population + + + align:start position:0% +of Houston's population +at the same time this book uh this paper + + align:start position:0% +at the same time this book uh this paper + + + align:start position:0% +at the same time this book uh this paper +we read by Sandeep I and others this is + + align:start position:0% +we read by Sandeep I and others this is + + + align:start position:0% +we read by Sandeep I and others this is +the same author he was recently wrote a + + align:start position:0% +the same author he was recently wrote a + + + align:start position:0% +the same author he was recently wrote a +book called total transition and it's + + align:start position:0% +book called total transition and it's + + + align:start position:0% +book called total transition and it's +called The Human Side of the renewable + + align:start position:0% +called The Human Side of the renewable + + + align:start position:0% +called The Human Side of the renewable +energy Revolution because he focuses on + + align:start position:0% +energy Revolution because he focuses on + + + align:start position:0% +energy Revolution because he focuses on +workers in the fossil fuel Industries if + + align:start position:0% +workers in the fossil fuel Industries if + + + align:start position:0% +workers in the fossil fuel Industries if +we and argues that if we have a + + align:start position:0% +we and argues that if we have a + + + align:start position:0% +we and argues that if we have a +renewable energy Revolution it is going + + align:start position:0% +renewable energy Revolution it is going + + + align:start position:0% +renewable energy Revolution it is going +to diffrently affect these workers so he + + align:start position:0% +to diffrently affect these workers so he + + + align:start position:0% +to diffrently affect these workers so he +investigates the situations of workers + + align:start position:0% +investigates the situations of workers + + + align:start position:0% +investigates the situations of workers +both in India and in Canada and you know + + align:start position:0% +both in India and in Canada and you know + + + align:start position:0% +both in India and in Canada and you know +this two things are not unconnected + + align:start position:0% +this two things are not unconnected + + + align:start position:0% +this two things are not unconnected +first the invocable adjusted + + align:start position:0% +first the invocable adjusted + + + align:start position:0% +first the invocable adjusted +implications of fossil fuel use and + + align:start position:0% +implications of fossil fuel use and + + + align:start position:0% +implications of fossil fuel use and +consumption and production uh focused on + + align:start position:0% +consumption and production uh focused on + + + align:start position:0% +consumption and production uh focused on +by Robert Bullard and shalanda Baker if + + align:start position:0% +by Robert Bullard and shalanda Baker if + + + align:start position:0% +by Robert Bullard and shalanda Baker if +you remember that article we read maybe + + align:start position:0% +you remember that article we read maybe + + + align:start position:0% +you remember that article we read maybe +a few weeks back + + align:start position:0% +a few weeks back + + + align:start position:0% +a few weeks back +but Sandeep Pai also says that in terms + + align:start position:0% +but Sandeep Pai also says that in terms + + + align:start position:0% +but Sandeep Pai also says that in terms +of Justice implications there's + + align:start position:0% +of Justice implications there's + + + align:start position:0% +of Justice implications there's +obviously a very large literature review + + align:start position:0% +obviously a very large literature review + + + align:start position:0% +obviously a very large literature review +focusing on a large literature looking + + align:start position:0% +focusing on a large literature looking + + + align:start position:0% +focusing on a large literature looking +at why this is going to affect workers + + align:start position:0% +at why this is going to affect workers + + + align:start position:0% +at why this is going to affect workers +and why workers might resist trying to + + align:start position:0% +and why workers might resist trying to + + + align:start position:0% +and why workers might resist trying to +take on an antigen + + align:start position:0% +take on an antigen + + + align:start position:0% +take on an antigen +a similar argument has been made by + + align:start position:0% +a similar argument has been made by + + + align:start position:0% +a similar argument has been made by +motto mildenberger in his book carbon + + align:start position:0% +motto mildenberger in his book carbon + + + align:start position:0% +motto mildenberger in his book carbon +captured he argues that our coalitions + + align:start position:0% +captured he argues that our coalitions + + + align:start position:0% +captured he argues that our coalitions +for climate abton + + align:start position:0% +for climate abton + + + align:start position:0% +for climate abton +are also we have to recognize split that + + align:start position:0% +are also we have to recognize split that + + + align:start position:0% +are also we have to recognize split that +business and labor have influence on the + + align:start position:0% +business and labor have influence on the + + + align:start position:0% +business and labor have influence on the +left and right coalitions for or + + align:start position:0% +left and right coalitions for or + + + align:start position:0% +left and right coalitions for or +opposing climate action so he argues + + align:start position:0% +opposing climate action so he argues + + + align:start position:0% +opposing climate action so he argues +that I'm actually in multiple countries + + align:start position:0% +that I'm actually in multiple countries + + + align:start position:0% +that I'm actually in multiple countries +have been stymied by the fact that even + + align:start position:0% +have been stymied by the fact that even + + + align:start position:0% +have been stymied by the fact that even +businesses or even for coalitions that + + align:start position:0% +businesses or even for coalitions that + + + align:start position:0% +businesses or even for coalitions that +are different planet action business and + + align:start position:0% +are different planet action business and + + + align:start position:0% +are different planet action business and +labor has substantial influence in + + align:start position:0% +labor has substantial influence in + + + align:start position:0% +labor has substantial influence in +stopping or exempting certain industries + + align:start position:0% +stopping or exempting certain industries + + + align:start position:0% +stopping or exempting certain industries +from climate action + + align:start position:0% +from climate action + + + align:start position:0% +from climate action +and so just to give you another sense of + + align:start position:0% +and so just to give you another sense of + + + align:start position:0% +and so just to give you another sense of +how cities are connected to Industrial + + align:start position:0% +how cities are connected to Industrial + + + align:start position:0% +how cities are connected to Industrial +missions quite often in this policy + + align:start position:0% +missions quite often in this policy + + + align:start position:0% +missions quite often in this policy +we've talked about cities that have + + align:start position:0% +we've talked about cities that have + + + align:start position:0% +we've talked about cities that have +relatively High population density and + + align:start position:0% +relatively High population density and + + + align:start position:0% +relatively High population density and +population + + align:start position:0% +population + + + align:start position:0% +population +looking at the population density and + + align:start position:0% +looking at the population density and + + + align:start position:0% +looking at the population density and +population United States this vertical + + align:start position:0% +population United States this vertical + + + align:start position:0% +population United States this vertical +access is the log of population density + + align:start position:0% +access is the log of population density + + + align:start position:0% +access is the log of population density +the horizontal axis is the industrial + + align:start position:0% +the horizontal axis is the industrial + + + align:start position:0% +the horizontal axis is the industrial +greenhouse gas emissions as a percentage + + align:start position:0% +greenhouse gas emissions as a percentage + + + align:start position:0% +greenhouse gas emissions as a percentage +of the total greenhouse gas emissions + + align:start position:0% +of the total greenhouse gas emissions + + + align:start position:0% +of the total greenhouse gas emissions +for the county this is all calculated + + align:start position:0% +for the county this is all calculated + + + align:start position:0% +for the county this is all calculated +from epa's industrial greenhouse gas + + align:start position:0% +from epa's industrial greenhouse gas + + + align:start position:0% +from epa's industrial greenhouse gas +figures you can click on this link and + + align:start position:0% +figures you can click on this link and + + + align:start position:0% +figures you can click on this link and +see the numbers there or calculate them + + align:start position:0% +see the numbers there or calculate them + + + align:start position:0% +see the numbers there or calculate them +for yourself if you want but the point + + align:start position:0% +for yourself if you want but the point + + + align:start position:0% +for yourself if you want but the point +is for cities if you look at the log of + + align:start position:0% +is for cities if you look at the log of + + + align:start position:0% +is for cities if you look at the log of +population density you can see the + + align:start position:0% +population density you can see the + + + align:start position:0% +population density you can see the +United States we have a nice belt curve + + align:start position:0% +United States we have a nice belt curve + + + align:start position:0% +United States we have a nice belt curve +if you put a histogram on the side or a + + align:start position:0% +if you put a histogram on the side or a + + + align:start position:0% +if you put a histogram on the side or a +density + + align:start position:0% +density + + + align:start position:0% +density +the log of population density is + + align:start position:0% +the log of population density is + + + align:start position:0% +the log of population density is +relatively belt or shaped you can see + + align:start position:0% +relatively belt or shaped you can see + + + align:start position:0% +relatively belt or shaped you can see +that means if we take the population + + align:start position:0% +that means if we take the population + + + align:start position:0% +that means if we take the population +density we have a few cities that are + + align:start position:0% +density we have a few cities that are + + + align:start position:0% +density we have a few cities that are +very high population density like New + + align:start position:0% +very high population density like New + + + align:start position:0% +very high population density like New +York and the vast majority of cities are + + align:start position:0% +York and the vast majority of cities are + + + align:start position:0% +York and the vast majority of cities are +lower population density but I take the + + align:start position:0% +lower population density but I take the + + + align:start position:0% +lower population density but I take the +log because it makes the data clear + + align:start position:0% +log because it makes the data clear + + + align:start position:0% +log because it makes the data clear +and so if you consider for example the + + align:start position:0% +and so if you consider for example the + + + align:start position:0% +and so if you consider for example the +highest population density of population + + align:start position:0% +highest population density of population + + + align:start position:0% +highest population density of population +countries in each state Cook County is + + align:start position:0% +countries in each state Cook County is + + + align:start position:0% +countries in each state Cook County is +the seat of Chicago Illinois you can see + + align:start position:0% +the seat of Chicago Illinois you can see + + + align:start position:0% +the seat of Chicago Illinois you can see +it has relatively low industrial gas gas + + align:start position:0% +it has relatively low industrial gas gas + + + align:start position:0% +it has relatively low industrial gas gas +emissions as a percentage of portal for + + align:start position:0% +emissions as a percentage of portal for + + + align:start position:0% +emissions as a percentage of portal for +the other highest population density and + + align:start position:0% +the other highest population density and + + + align:start position:0% +the other highest population density and +population countries in each state + + align:start position:0% +population countries in each state + + + align:start position:0% +population countries in each state +that's true for Maricopa County which is + + align:start position:0% +that's true for Maricopa County which is + + + align:start position:0% +that's true for Maricopa County which is +the home of Phoenix Arizona + + align:start position:0% +the home of Phoenix Arizona + + + align:start position:0% +the home of Phoenix Arizona +Dallas County which is the seat of + + align:start position:0% +Dallas County which is the seat of + + + align:start position:0% +Dallas County which is the seat of +Dallas Texas + + align:start position:0% +Dallas Texas + + + align:start position:0% +Dallas Texas +County Washington Seattle + + align:start position:0% +County Washington Seattle + + + align:start position:0% +County Washington Seattle +has relatively low industrial emissions + + align:start position:0% +has relatively low industrial emissions + + + align:start position:0% +has relatively low industrial emissions +Wayne County is the seat of Detroit + + align:start position:0% +Wayne County is the seat of Detroit + + + align:start position:0% +Wayne County is the seat of Detroit +and New York county is one of the four + + align:start position:0% +and New York county is one of the four + + + align:start position:0% +and New York county is one of the four +very high population counties that + + align:start position:0% +very high population counties that + + + align:start position:0% +very high population counties that +reprise New York and so generally the + + align:start position:0% +reprise New York and so generally the + + + align:start position:0% +reprise New York and so generally the +way we talk about cities as centers of + + align:start position:0% +way we talk about cities as centers of + + + align:start position:0% +way we talk about cities as centers of +consumption if these are the cities that + + align:start position:0% +consumption if these are the cities that + + + align:start position:0% +consumption if these are the cities that +come to mind then yes we have relative + + align:start position:0% +come to mind then yes we have relative + + + align:start position:0% +come to mind then yes we have relative +low industrial emissions associated with + + align:start position:0% +low industrial emissions associated with + + + align:start position:0% +low industrial emissions associated with +cities + + align:start position:0% +cities + + + align:start position:0% +cities +but now let's look at this chart we look + + align:start position:0% +but now let's look at this chart we look + + + align:start position:0% +but now let's look at this chart we look +at this chart we can see that there's + + align:start position:0% +at this chart we can see that there's + + + align:start position:0% +at this chart we can see that there's +all these other cities up here that have + + align:start position:0% +all these other cities up here that have + + + align:start position:0% +all these other cities up here that have +much higher industrial greenhouse gas + + align:start position:0% +much higher industrial greenhouse gas + + + align:start position:0% +much higher industrial greenhouse gas +emissions which cities are those Which + + align:start position:0% +emissions which cities are those Which + + + align:start position:0% +emissions which cities are those Which +counties are those + + align:start position:0% +counties are those + + + align:start position:0% +counties are those +if we looked at the uh Philadelphia also + + align:start position:0% +if we looked at the uh Philadelphia also + + + align:start position:0% +if we looked at the uh Philadelphia also +has relatively low industrial emissions + + align:start position:0% +has relatively low industrial emissions + + + align:start position:0% +has relatively low industrial emissions +as a percentage of this total + + align:start position:0% +as a percentage of this total + + + align:start position:0% +as a percentage of this total +but if we look at the highest population + + align:start position:0% +but if we look at the highest population + + + align:start position:0% +but if we look at the highest population +density and relatively at high + + align:start position:0% +density and relatively at high + + + align:start position:0% +density and relatively at high +industrial admitting counties in each + + align:start position:0% +industrial admitting counties in each + + + align:start position:0% +industrial admitting counties in each +state and we get to a different set of + + align:start position:0% +state and we get to a different set of + + + align:start position:0% +state and we get to a different set of +cities that we don't often talk about in + + align:start position:0% +cities that we don't often talk about in + + + align:start position:0% +cities that we don't often talk about in +urban planning Tulsa Oklahoma Newcastle + + align:start position:0% +urban planning Tulsa Oklahoma Newcastle + + + align:start position:0% +urban planning Tulsa Oklahoma Newcastle +Delaware has you know about a quarter of + + align:start position:0% +Delaware has you know about a quarter of + + + align:start position:0% +Delaware has you know about a quarter of +their emissions are quarter of their + + align:start position:0% +their emissions are quarter of their + + + align:start position:0% +their emissions are quarter of their +greenhouse gas stations are from + + align:start position:0% +greenhouse gas stations are from + + + align:start position:0% +greenhouse gas stations are from +industry + + align:start position:0% +industry + + + align:start position:0% +industry +Denver Colorado has relatively high + + align:start position:0% +Denver Colorado has relatively high + + + align:start position:0% +Denver Colorado has relatively high +balance gas emissions + + align:start position:0% +balance gas emissions + + + align:start position:0% +balance gas emissions +Jefferson County and Alabama has + + align:start position:0% +Jefferson County and Alabama has + + + align:start position:0% +Jefferson County and Alabama has +relatively highly greenhouse gas + + align:start position:0% +relatively highly greenhouse gas + + + align:start position:0% +relatively highly greenhouse gas +stations + + align:start position:0% +stations + + + align:start position:0% +stations +Dallas again shows up in this list and + + align:start position:0% +Dallas again shows up in this list and + + + align:start position:0% +Dallas again shows up in this list and +it's you know about 20 of submissions + + align:start position:0% +it's you know about 20 of submissions + + + align:start position:0% +it's you know about 20 of submissions +are pre-owned gas those 20 it would be + + align:start position:0% +are pre-owned gas those 20 it would be + + + align:start position:0% +are pre-owned gas those 20 it would be +asking applications of its portal so + + align:start position:0% +asking applications of its portal so + + + align:start position:0% +asking applications of its portal so +it's higher than other cities that we + + align:start position:0% +it's higher than other cities that we + + + align:start position:0% +it's higher than other cities that we +looked at + + align:start position:0% +looked at + + + align:start position:0% +looked at +and Cuyahoga County in Ohio the seat of + + align:start position:0% +and Cuyahoga County in Ohio the seat of + + + align:start position:0% +and Cuyahoga County in Ohio the seat of +Cleveland also has surprisingly higher + + align:start position:0% +Cleveland also has surprisingly higher + + + align:start position:0% +Cleveland also has surprisingly higher +but still relatively low green ounce gas + + align:start position:0% +but still relatively low green ounce gas + + + align:start position:0% +but still relatively low green ounce gas +missions + + align:start position:0% +missions + + + align:start position:0% +missions +let's look at some of the cities that + + align:start position:0% +let's look at some of the cities that + + + align:start position:0% +let's look at some of the cities that +had extremely high industrial admissions + + align:start position:0% +had extremely high industrial admissions + + + align:start position:0% +had extremely high industrial admissions +as a percentage of the total what are + + align:start position:0% +as a percentage of the total what are + + + align:start position:0% +as a percentage of the total what are +those cities and counties + + align:start position:0% +those cities and counties + + + align:start position:0% +those cities and counties +if we look at the highest industrial + + align:start position:0% +if we look at the highest industrial + + + align:start position:0% +if we look at the highest industrial +emitting counties with high population + + align:start position:0% +emitting counties with high population + + + align:start position:0% +emitting counties with high population +densities East Baton Rouge Saint John + + align:start position:0% +densities East Baton Rouge Saint John + + + align:start position:0% +densities East Baton Rouge Saint John +the Baptist County uh test you the + + align:start position:0% +the Baptist County uh test you the + + + align:start position:0% +the Baptist County uh test you the +county probably mispronounced that in St + + align:start position:0% +county probably mispronounced that in St + + + align:start position:0% +county probably mispronounced that in St +Charles County and Ascension County are + + align:start position:0% +Charles County and Ascension County are + + + align:start position:0% +Charles County and Ascension County are +all in Louisiana + + align:start position:0% +all in Louisiana + + + align:start position:0% +all in Louisiana +in fact if we go back to Robert + + align:start position:0% +in fact if we go back to Robert + + + align:start position:0% +in fact if we go back to Robert +bullard's the reason why he started + + align:start position:0% +bullard's the reason why he started + + + align:start position:0% +bullard's the reason why he started +studying environmental justice in the + + align:start position:0% +studying environmental justice in the + + + align:start position:0% +studying environmental justice in the +first place you can see that the highest + + align:start position:0% +first place you can see that the highest + + + align:start position:0% +first place you can see that the highest +population density and Industrial + + align:start position:0% +population density and Industrial + + + align:start position:0% +population density and Industrial +admitting counties are all in Louisiana + + align:start position:0% +admitting counties are all in Louisiana + + + align:start position:0% +admitting counties are all in Louisiana +Texas Virginia these are not only places + + align:start position:0% +Texas Virginia these are not only places + + + align:start position:0% +Texas Virginia these are not only places +that are concentrated in a few States + + align:start position:0% +that are concentrated in a few States + + + align:start position:0% +that are concentrated in a few States +remarkably High portions of their + + align:start position:0% +remarkably High portions of their + + + align:start position:0% +remarkably High portions of their +greenhouse gas stations come from + + align:start position:0% +greenhouse gas stations come from + + + align:start position:0% +greenhouse gas stations come from +industry with about 70 percent up to 92 + + align:start position:0% +industry with about 70 percent up to 92 + + + align:start position:0% +industry with about 70 percent up to 92 +percent uh in Covington Virginia they + + align:start position:0% +percent uh in Covington Virginia they + + + align:start position:0% +percent uh in Covington Virginia they +have extremely high populations for + + align:start position:0% +have extremely high populations for + + + align:start position:0% +have extremely high populations for +their area they have very high + + align:start position:0% +their area they have very high + + + align:start position:0% +their area they have very high +population densities but also what I + + align:start position:0% +population densities but also what I + + + align:start position:0% +population densities but also what I +want to emphasize to you is that they + + align:start position:0% +want to emphasize to you is that they + + + align:start position:0% +want to emphasize to you is that they +have extremely high non-white + + align:start position:0% +have extremely high non-white + + + align:start position:0% +have extremely high non-white +populations that in this case not only + + align:start position:0% +populations that in this case not only + + + align:start position:0% +populations that in this case not only +are the people subjects to the + + align:start position:0% +are the people subjects to the + + + align:start position:0% +are the people subjects to the +consequences or the burdens of + + align:start position:0% +consequences or the burdens of + + + align:start position:0% +consequences or the burdens of +industrial missions but these are all + + align:start position:0% +industrial missions but these are all + + + align:start position:0% +industrial missions but these are all +people people who also may work in these + + align:start position:0% +people people who also may work in these + + + align:start position:0% +people people who also may work in these +industries as well so this hopefully + + align:start position:0% +industries as well so this hopefully + + + align:start position:0% +industries as well so this hopefully +brings into + + align:start position:0% +brings into + + + align:start position:0% +brings into +um focused the way that these different + + align:start position:0% +um focused the way that these different + + + align:start position:0% +um focused the way that these different +ideas about livelihood and environmental + + align:start position:0% +ideas about livelihood and environmental + + + align:start position:0% +ideas about livelihood and environmental +burden and climate action can coincide + + align:start position:0% +burden and climate action can coincide + + + align:start position:0% +burden and climate action can coincide +all of these counties are extremely high + + align:start position:0% +all of these counties are extremely high + + + align:start position:0% +all of these counties are extremely high +percentages of non-white population many + + align:start position:0% +percentages of non-white population many + + + align:start position:0% +percentages of non-white population many +cases African-Americans + + align:start position:0% +cases African-Americans + + + align:start position:0% +cases African-Americans +they have high population densities + + align:start position:0% +they have high population densities + + + align:start position:0% +they have high population densities +either essentially highly urbanized + + align:start position:0% +either essentially highly urbanized + + + align:start position:0% +either essentially highly urbanized +areas and they're areas that also have + + align:start position:0% +areas and they're areas that also have + + + align:start position:0% +areas and they're areas that also have +very high industrial missions + + align:start position:0% +very high industrial missions + + + align:start position:0% +very high industrial missions +this is an area in Louisiana known I + + align:start position:0% +this is an area in Louisiana known I + + + align:start position:0% +this is an area in Louisiana known I +guess known uh recently as cancer alley + + align:start position:0% +guess known uh recently as cancer alley + + + align:start position:0% +guess known uh recently as cancer alley +it's a phrase used in this Republica + + align:start position:0% +it's a phrase used in this Republica + + + align:start position:0% +it's a phrase used in this Republica +investigation about welcome to cancer + + align:start position:0% +investigation about welcome to cancer + + + align:start position:0% +investigation about welcome to cancer +alley Where toxic air is about to get + + align:start position:0% +alley Where toxic air is about to get + + + align:start position:0% +alley Where toxic air is about to get +much worse okay the articles about how + + align:start position:0% +much worse okay the articles about how + + + align:start position:0% +much worse okay the articles about how +air quality has improved for decades + + align:start position:0% +air quality has improved for decades + + + align:start position:0% +air quality has improved for decades +across United States but Louisiana's + + align:start position:0% +across United States but Louisiana's + + + align:start position:0% +across United States but Louisiana's +backsliding because their analysis found + + align:start position:0% +backsliding because their analysis found + + + align:start position:0% +backsliding because their analysis found +that many new industrial plants will + + align:start position:0% +that many new industrial plants will + + + align:start position:0% +that many new industrial plants will +increase the concentration of cancer + + align:start position:0% +increase the concentration of cancer + + + align:start position:0% +increase the concentration of cancer +causing chemicals predominantly black + + align:start position:0% +causing chemicals predominantly black + + + align:start position:0% +causing chemicals predominantly black +and poor communities so if we think + + align:start position:0% +and poor communities so if we think + + + align:start position:0% +and poor communities so if we think +about cities industrial missions it's + + align:start position:0% +about cities industrial missions it's + + + align:start position:0% +about cities industrial missions it's +not only cities like New York that are + + align:start position:0% +not only cities like New York that are + + + align:start position:0% +not only cities like New York that are +perhaps centers of consumption but other + + align:start position:0% +perhaps centers of consumption but other + + + align:start position:0% +perhaps centers of consumption but other +cities actually have high percentages of + + align:start position:0% +cities actually have high percentages of + + + align:start position:0% +cities actually have high percentages of +industrial pollution within the city + + align:start position:0% +industrial pollution within the city + + + align:start position:0% +industrial pollution within the city +boundaries or the county boundaries as + + align:start position:0% +boundaries or the county boundaries as + + + align:start position:0% +boundaries or the county boundaries as +well + + align:start position:0% +well + + + align:start position:0% +well +if we look at how fossil fuel + + align:start position:0% +if we look at how fossil fuel + + + align:start position:0% +if we look at how fossil fuel +infrastructure is distributed across the + + align:start position:0% +infrastructure is distributed across the + + + align:start position:0% +infrastructure is distributed across the +U.S these are some graphics that my + + align:start position:0% +U.S these are some graphics that my + + + align:start position:0% +U.S these are some graphics that my +student girl alumn and I made a few + + align:start position:0% +student girl alumn and I made a few + + + align:start position:0% +student girl alumn and I made a few +years ago from U.S Energy Information + + align:start position:0% +years ago from U.S Energy Information + + + align:start position:0% +years ago from U.S Energy Information +Administration and homosecurity data you + + align:start position:0% +Administration and homosecurity data you + + + align:start position:0% +Administration and homosecurity data you +can see power plants are relatively + + align:start position:0% +can see power plants are relatively + + + align:start position:0% +can see power plants are relatively +distributed across the U.S this graphic + + align:start position:0% +distributed across the U.S this graphic + + + align:start position:0% +distributed across the U.S this graphic +of coal natural gas and petroleum plants + + align:start position:0% +of coal natural gas and petroleum plants + + + align:start position:0% +of coal natural gas and petroleum plants +effectively follows the population or + + align:start position:0% +effectively follows the population or + + + align:start position:0% +effectively follows the population or +the urban pattern of the United States + + align:start position:0% +the urban pattern of the United States + + + align:start position:0% +the urban pattern of the United States +but you can see that natural gas is + + align:start position:0% +but you can see that natural gas is + + + align:start position:0% +but you can see that natural gas is +probably concentrated in the exact place + + align:start position:0% +probably concentrated in the exact place + + + align:start position:0% +probably concentrated in the exact place +as we've just talked about Texas and + + align:start position:0% +as we've just talked about Texas and + + + align:start position:0% +as we've just talked about Texas and +Louisiana prefer uh Virginia is a + + align:start position:0% +Louisiana prefer uh Virginia is a + + + align:start position:0% +Louisiana prefer uh Virginia is a +different case I think out there look at + + align:start position:0% +different case I think out there look at + + + align:start position:0% +different case I think out there look at +Natural Gas This is highly concentrated + + align:start position:0% +Natural Gas This is highly concentrated + + + align:start position:0% +Natural Gas This is highly concentrated +here partly because of important and + + align:start position:0% +here partly because of important and + + + align:start position:0% +here partly because of important and +Export but also because of petrochemical + + align:start position:0% +Export but also because of petrochemical + + + align:start position:0% +Export but also because of petrochemical +refining and production + + align:start position:0% +refining and production + + + align:start position:0% +refining and production +and if we look at Holy oil and petroleum + + align:start position:0% +and if we look at Holy oil and petroleum + + + align:start position:0% +and if we look at Holy oil and petroleum +we can see our pipelines again run from + + align:start position:0% +we can see our pipelines again run from + + + align:start position:0% +we can see our pipelines again run from +Texas Louisiana pretty much following + + align:start position:0% +Texas Louisiana pretty much following + + + align:start position:0% +Texas Louisiana pretty much following +the urban pattern of the United States + + align:start position:0% +the urban pattern of the United States + + + align:start position:0% +the urban pattern of the United States +we look at cumulative impacts yes we see + + align:start position:0% +we look at cumulative impacts yes we see + + + align:start position:0% +we look at cumulative impacts yes we see +fossil appeal infrastructure + + align:start position:0% +fossil appeal infrastructure + + + align:start position:0% +fossil appeal infrastructure +concentrated across the entire United + + align:start position:0% +concentrated across the entire United + + + align:start position:0% +concentrated across the entire United +States but clearly based on the + + align:start position:0% +States but clearly based on the + + + align:start position:0% +States but clearly based on the +industrial emissions we looked at before + + align:start position:0% +industrial emissions we looked at before + + + align:start position:0% +industrial emissions we looked at before +the industrial emissions are very + + align:start position:0% +the industrial emissions are very + + + align:start position:0% +the industrial emissions are very +differently distributed across urban + + align:start position:0% +differently distributed across urban + + + align:start position:0% +differently distributed across urban +areas and states + + align:start position:0% +areas and states + + + align:start position:0% +areas and states +which brings me to the akman LL 2017 + + align:start position:0% +which brings me to the akman LL 2017 + + + align:start position:0% +which brings me to the akman LL 2017 +paper just to focus on this paper it's + + align:start position:0% +paper just to focus on this paper it's + + + align:start position:0% +paper just to focus on this paper it's +on global climate policies for energy + + align:start position:0% +on global climate policies for energy + + + align:start position:0% +on global climate policies for energy +intensive Industries we're going to go + + align:start position:0% +intensive Industries we're going to go + + + align:start position:0% +intensive Industries we're going to go +through a bunch of acronyms here at the + + align:start position:0% +through a bunch of acronyms here at the + + + align:start position:0% +through a bunch of acronyms here at the +global level we have energy intensive + + align:start position:0% +global level we have energy intensive + + + align:start position:0% +global level we have energy intensive +Industries like steel cement aluminum + + align:start position:0% +Industries like steel cement aluminum + + + align:start position:0% +Industries like steel cement aluminum +fertilizer and Plastics + + align:start position:0% +fertilizer and Plastics + + + align:start position:0% +fertilizer and Plastics +that's e-i-ims ba teams are the best + + align:start position:0% +that's e-i-ims ba teams are the best + + + align:start position:0% +that's e-i-ims ba teams are the best +available Technologies but crucially the + + align:start position:0% +available Technologies but crucially the + + + align:start position:0% +available Technologies but crucially the +paper argues that they only reduce + + align:start position:0% +paper argues that they only reduce + + + align:start position:0% +paper argues that they only reduce +eviction 15 or 30 percent so hopefully + + align:start position:0% +eviction 15 or 30 percent so hopefully + + + align:start position:0% +eviction 15 or 30 percent so hopefully +the five years since this paper is + + align:start position:0% +the five years since this paper is + + + align:start position:0% +the five years since this paper is +written we've come up with more ideas + + align:start position:0% +written we've come up with more ideas + + + align:start position:0% +written we've come up with more ideas +for how to decarbonize industry but at + + align:start position:0% +for how to decarbonize industry but at + + + align:start position:0% +for how to decarbonize industry but at +least the best available Technologies + + align:start position:0% +least the best available Technologies + + + align:start position:0% +least the best available Technologies +five years ago only reduced emissions of + + align:start position:0% +five years ago only reduced emissions of + + + align:start position:0% +five years ago only reduced emissions of +fraction of what we need + + align:start position:0% +fraction of what we need + + + align:start position:0% +fraction of what we need +uh there's a number of other acronyms uh + + align:start position:0% +uh there's a number of other acronyms uh + + + align:start position:0% +uh there's a number of other acronyms uh +quite often about an international + + align:start position:0% +quite often about an international + + + align:start position:0% +quite often about an international +climate negotiations common but + + align:start position:0% +climate negotiations common but + + + align:start position:0% +climate negotiations common but +differentiated responsibilities cbdrs + + align:start position:0% +differentiated responsibilities cbdrs + + + align:start position:0% +differentiated responsibilities cbdrs +Queen development mechanism CBM this is + + align:start position:0% +Queen development mechanism CBM this is + + + align:start position:0% +Queen development mechanism CBM this is +a mechanism intended for rich countries + + align:start position:0% +a mechanism intended for rich countries + + + align:start position:0% +a mechanism intended for rich countries +to help poor countries decarbonize and + + align:start position:0% +to help poor countries decarbonize and + + + align:start position:0% +to help poor countries decarbonize and +meet their indc's their intended + + align:start position:0% +meet their indc's their intended + + + align:start position:0% +meet their indc's their intended +naturally determined contributions this + + align:start position:0% +naturally determined contributions this + + + align:start position:0% +naturally determined contributions this +is what we said in the Paris climate + + align:start position:0% +is what we said in the Paris climate + + + align:start position:0% +is what we said in the Paris climate +agreement every country came said what + + align:start position:0% +agreement every country came said what + + + align:start position:0% +agreement every country came said what +their intended nationally determined + + align:start position:0% +their intended nationally determined + + + align:start position:0% +their intended nationally determined +contribution was or the indc basically + + align:start position:0% +contribution was or the indc basically + + + align:start position:0% +contribution was or the indc basically +every country came and said this is the + + align:start position:0% +every country came and said this is the + + + align:start position:0% +every country came and said this is the +best we can do on climate change + + align:start position:0% +best we can do on climate change + + + align:start position:0% +best we can do on climate change +of course there's a lot of discussion + + align:start position:0% +of course there's a lot of discussion + + + align:start position:0% +of course there's a lot of discussion +now and climate policy about border + + align:start position:0% +now and climate policy about border + + + align:start position:0% +now and climate policy about border +Department adjustments these are the + + align:start position:0% +Department adjustments these are the + + + align:start position:0% +Department adjustments these are the +Border carbon adjustments that rich + + align:start position:0% +Border carbon adjustments that rich + + + align:start position:0% +Border carbon adjustments that rich +countries might use to try to + + align:start position:0% +countries might use to try to + + + align:start position:0% +countries might use to try to +um + + align:start position:0% +um + + + align:start position:0% +um +to account for the embodied energy that + + align:start position:0% +to account for the embodied energy that + + + align:start position:0% +to account for the embodied energy that +they're importing but also Nest + + align:start position:0% +they're importing but also Nest + + + align:start position:0% +they're importing but also Nest +hopefully not causing additional leakage + + align:start position:0% +hopefully not causing additional leakage + + + align:start position:0% +hopefully not causing additional leakage +of jobs to other countries in other + + align:start position:0% +of jobs to other countries in other + + + align:start position:0% +of jobs to other countries in other +words if other countries seem like they + + align:start position:0% +words if other countries seem like they + + + align:start position:0% +words if other countries seem like they +have low Beyonce gas consumption our + + align:start position:0% +have low Beyonce gas consumption our + + + align:start position:0% +have low Beyonce gas consumption our +emissions Associated consumption and + + align:start position:0% +emissions Associated consumption and + + + align:start position:0% +emissions Associated consumption and +maybe because they're actually exporting + + align:start position:0% +maybe because they're actually exporting + + + align:start position:0% +maybe because they're actually exporting +their goods to rich countries so both + + align:start position:0% +their goods to rich countries so both + + + align:start position:0% +their goods to rich countries so both +rich and poor companies have proposed or + + align:start position:0% +rich and poor companies have proposed or + + + align:start position:0% +rich and poor companies have proposed or +carbon adjustments where we can + + align:start position:0% +carbon adjustments where we can + + + align:start position:0% +carbon adjustments where we can +hopefully account for this at the border + + align:start position:0% +hopefully account for this at the border + + + align:start position:0% +hopefully account for this at the border +when when materials and goods are + + align:start position:0% +when when materials and goods are + + + align:start position:0% +when when materials and goods are +imported + + align:start position:0% +imported + + + align:start position:0% +imported +and finally CCF is something we're going + + align:start position:0% +and finally CCF is something we're going + + + align:start position:0% +and finally CCF is something we're going +to talk about a lot going forward carbon + + align:start position:0% +to talk about a lot going forward carbon + + + align:start position:0% +to talk about a lot going forward carbon +capture and storage often called carbon + + align:start position:0% +capture and storage often called carbon + + + align:start position:0% +capture and storage often called carbon +capture utilization and storage now + + align:start position:0% +capture utilization and storage now + + + align:start position:0% +capture utilization and storage now +just to give you a sense of where + + align:start position:0% +just to give you a sense of where + + + align:start position:0% +just to give you a sense of where +greenhouse gas stations have gone and + + align:start position:0% +greenhouse gas stations have gone and + + + align:start position:0% +greenhouse gas stations have gone and +this is a plot from the Almond paper if + + align:start position:0% +this is a plot from the Almond paper if + + + align:start position:0% +this is a plot from the Almond paper if +the data is normalized in 1990 when the + + align:start position:0% +the data is normalized in 1990 when the + + + align:start position:0% +the data is normalized in 1990 when the +UN started accounting you can see that + + align:start position:0% +UN started accounting you can see that + + + align:start position:0% +UN started accounting you can see that +world emissions have gone up + + align:start position:0% +world emissions have gone up + + + align:start position:0% +world emissions have gone up +admissions in Japan and the EU have gone + + align:start position:0% +admissions in Japan and the EU have gone + + + align:start position:0% +admissions in Japan and the EU have gone +down in the U.S they've stayed + + align:start position:0% +down in the U.S they've stayed + + + align:start position:0% +down in the U.S they've stayed +relatively flat either industrial direct + + align:start position:0% +relatively flat either industrial direct + + + align:start position:0% +relatively flat either industrial direct +greenhouse gas missions but obviously + + align:start position:0% +greenhouse gas missions but obviously + + + align:start position:0% +greenhouse gas missions but obviously +rapidly developing countries like China + + align:start position:0% +rapidly developing countries like China + + + align:start position:0% +rapidly developing countries like China +India and Brazil have rapidly increased + + align:start position:0% +India and Brazil have rapidly increased + + + align:start position:0% +India and Brazil have rapidly increased +their greenhouse gas emissions but we + + align:start position:0% +their greenhouse gas emissions but we + + + align:start position:0% +their greenhouse gas emissions but we +should also recognize that these + + align:start position:0% +should also recognize that these + + + align:start position:0% +should also recognize that these +greenhouse gas stations have increased + + align:start position:0% +greenhouse gas stations have increased + + + align:start position:0% +greenhouse gas stations have increased +in these countries because of their + + align:start position:0% +in these countries because of their + + + align:start position:0% +in these countries because of their +exports to the rich and developed world + + align:start position:0% +exports to the rich and developed world + + + align:start position:0% +exports to the rich and developed world +so this brings up fundamental issues of + + align:start position:0% +so this brings up fundamental issues of + + + align:start position:0% +so this brings up fundamental issues of +efficiency equity and fairness + + align:start position:0% +efficiency equity and fairness + + + align:start position:0% +efficiency equity and fairness +there's a lot of issues that need to be + + align:start position:0% +there's a lot of issues that need to be + + + align:start position:0% +there's a lot of issues that need to be +negotiated within between countries + + align:start position:0% +negotiated within between countries + + + align:start position:0% +negotiated within between countries +around industrial emissions there's the + + align:start position:0% +around industrial emissions there's the + + + align:start position:0% +around industrial emissions there's the +idea of carbon leakage this is where + + align:start position:0% +idea of carbon leakage this is where + + + align:start position:0% +idea of carbon leakage this is where +there will be lots of competitiveness + + align:start position:0% +there will be lots of competitiveness + + + align:start position:0% +there will be lots of competitiveness +and relocation of Industry to other + + align:start position:0% +and relocation of Industry to other + + + align:start position:0% +and relocation of Industry to other +countries + + align:start position:0% +countries + + + align:start position:0% +countries +there's questions about political + + align:start position:0% +there's questions about political + + + align:start position:0% +there's questions about political +stability application infrastructure + + align:start position:0% +stability application infrastructure + + + align:start position:0% +stability application infrastructure +labor legislation and protections access + + align:start position:0% +labor legislation and protections access + + + align:start position:0% +labor legislation and protections access +to markets and feedstock and Industrial + + align:start position:0% +to markets and feedstock and Industrial + + + align:start position:0% +to markets and feedstock and Industrial +policy the reason why we're talking + + align:start position:0% +policy the reason why we're talking + + + align:start position:0% +policy the reason why we're talking +about in this urban planning class is + + align:start position:0% +about in this urban planning class is + + + align:start position:0% +about in this urban planning class is +that we think about all these as issues + + align:start position:0% +that we think about all these as issues + + + align:start position:0% +that we think about all these as issues +to be negotiated within and between + + align:start position:0% +to be negotiated within and between + + + align:start position:0% +to be negotiated within and between +countries be issue for cities how do you + + align:start position:0% +countries be issue for cities how do you + + + align:start position:0% +countries be issue for cities how do you +negotiate these issues the Queens cities + + align:start position:0% +negotiate these issues the Queens cities + + + align:start position:0% +negotiate these issues the Queens cities +and within countries in other words + + align:start position:0% +and within countries in other words + + + align:start position:0% +and within countries in other words +again if we have centers of consumption + + align:start position:0% +again if we have centers of consumption + + + align:start position:0% +again if we have centers of consumption +quite often on the coasts we are drawing + + align:start position:0% +quite often on the coasts we are drawing + + + align:start position:0% +quite often on the coasts we are drawing +on Industrial missions that are in other + + align:start position:0% +on Industrial missions that are in other + + + align:start position:0% +on Industrial missions that are in other +parts of the country or other parts of + + align:start position:0% +parts of the country or other parts of + + + align:start position:0% +parts of the country or other parts of +the world how do we account for this + + align:start position:0% +the world how do we account for this + + + align:start position:0% +the world how do we account for this +consumption what do relatively Rich + + align:start position:0% +consumption what do relatively Rich + + + align:start position:0% +consumption what do relatively Rich +developed areas such as cities in North + + align:start position:0% +developed areas such as cities in North + + + align:start position:0% +developed areas such as cities in North +America have to do to account for their + + align:start position:0% +America have to do to account for their + + + align:start position:0% +America have to do to account for their +missions or how to make up for their + + align:start position:0% +missions or how to make up for their + + + align:start position:0% +missions or how to make up for their +consumption + + align:start position:0% +consumption + + + align:start position:0% +consumption +so this again is a good time to focus on + + align:start position:0% +so this again is a good time to focus on + + + align:start position:0% +so this again is a good time to focus on +how we can scale down to these National + + align:start position:0% +how we can scale down to these National + + + align:start position:0% +how we can scale down to these National +policies and I'll argue to you that a + + align:start position:0% +policies and I'll argue to you that a + + + align:start position:0% +policies and I'll argue to you that a +lot of these policies that exist at the + + align:start position:0% +lot of these policies that exist at the + + + align:start position:0% +lot of these policies that exist at the +national level that are discussed in + + align:start position:0% +national level that are discussed in + + + align:start position:0% +national level that are discussed in +this online paper also have equivalence + + align:start position:0% +this online paper also have equivalence + + + align:start position:0% +this online paper also have equivalence +at the urban scale + + align:start position:0% +at the urban scale + + + align:start position:0% +at the urban scale +for example in the first policy here we + + align:start position:0% +for example in the first policy here we + + + align:start position:0% +for example in the first policy here we +have mitigation policies and measures + + align:start position:0% +have mitigation policies and measures + + + align:start position:0% +have mitigation policies and measures +that have an intended direct effect we + + align:start position:0% +that have an intended direct effect we + + + align:start position:0% +that have an intended direct effect we +have mitigation policies measures with + + align:start position:0% +have mitigation policies measures with + + + align:start position:0% +have mitigation policies measures with +intended long-term effects in the EU we + + align:start position:0% +intended long-term effects in the EU we + + + align:start position:0% +intended long-term effects in the EU we +had a regulated Target for industry + + align:start position:0% +had a regulated Target for industry + + + align:start position:0% +had a regulated Target for industry +together the power sector to reduce gas + + align:start position:0% +together the power sector to reduce gas + + + align:start position:0% +together the power sector to reduce gas +missions provide the emissions creating + + align:start position:0% +missions provide the emissions creating + + + align:start position:0% +missions provide the emissions creating +and scheme we've obviously discussed + + align:start position:0% +and scheme we've obviously discussed + + + align:start position:0% +and scheme we've obviously discussed +possible emissions trading schemes in + + align:start position:0% +possible emissions trading schemes in + + + align:start position:0% +possible emissions trading schemes in +the U.S not only uh does California have + + align:start position:0% +the U.S not only uh does California have + + + align:start position:0% +the U.S not only uh does California have +an emissions trading scheme within + + align:start position:0% +an emissions trading scheme within + + + align:start position:0% +an emissions trading scheme within +California we have the regional + + align:start position:0% +California we have the regional + + + align:start position:0% +California we have the regional +greenhouse gas initiative Reggie on the + + align:start position:0% +greenhouse gas initiative Reggie on the + + + align:start position:0% +greenhouse gas initiative Reggie on the +East Coast trying to create emissions + + align:start position:0% +East Coast trying to create emissions + + + align:start position:0% +East Coast trying to create emissions +within the East Coast or middle States + + align:start position:0% +within the East Coast or middle States + + + align:start position:0% +within the East Coast or middle States +we also had the clean power plan which + + align:start position:0% +we also had the clean power plan which + + + align:start position:0% +we also had the clean power plan which +would allow the power sector in + + align:start position:0% +would allow the power sector in + + + align:start position:0% +would allow the power sector in +different states to meet emissions + + align:start position:0% +different states to meet emissions + + + align:start position:0% +different states to meet emissions +Targets in different ways uh regulations + + align:start position:0% +Targets in different ways uh regulations + + + align:start position:0% +Targets in different ways uh regulations +reducing emissions of industrial gases I + + align:start position:0% +reducing emissions of industrial gases I + + + align:start position:0% +reducing emissions of industrial gases I +think some states have a beasts like + + align:start position:0% +think some states have a beasts like + + + align:start position:0% +think some states have a beasts like +Reggie and California having police + + align:start position:0% +Reggie and California having police + + + align:start position:0% +Reggie and California having police +regulations defined to reduce depictions + + align:start position:0% +regulations defined to reduce depictions + + + align:start position:0% +regulations defined to reduce depictions +of inductible gases and there's Energy + + align:start position:0% +of inductible gases and there's Energy + + + align:start position:0% +of inductible gases and there's Energy +Efficiency directives that can be + + align:start position:0% +Efficiency directives that can be + + + align:start position:0% +Efficiency directives that can be +applied differently at the city and + + align:start position:0% +applied differently at the city and + + + align:start position:0% +applied differently at the city and +state level + + align:start position:0% +state level + + + align:start position:0% +state level +we also have in our most recent + + align:start position:0% +we also have in our most recent + + + align:start position:0% +we also have in our most recent +legislation the inflation reduction act + + align:start position:0% +legislation the inflation reduction act + + + align:start position:0% +legislation the inflation reduction act +we have funding for demonstration of + + align:start position:0% +we have funding for demonstration of + + + align:start position:0% +we have funding for demonstration of +carbon capture and storage and bioenergy + + align:start position:0% +carbon capture and storage and bioenergy + + + align:start position:0% +carbon capture and storage and bioenergy +for occur + + align:start position:0% +for occur + + + align:start position:0% +for occur +Japan has implementation of voluntary + + align:start position:0% +Japan has implementation of voluntary + + + align:start position:0% +Japan has implementation of voluntary +action plans by Industries promoting + + align:start position:0% +action plans by Industries promoting + + + align:start position:0% +action plans by Industries promoting +Energy Efficiency obviously in the last + + align:start position:0% +Energy Efficiency obviously in the last + + + align:start position:0% +Energy Efficiency obviously in the last +few passes we've talked about how cities + + align:start position:0% +few passes we've talked about how cities + + + align:start position:0% +few passes we've talked about how cities +have implemented different Energy + + align:start position:0% +have implemented different Energy + + + align:start position:0% +have implemented different Energy +Efficiency programs we also have + + align:start position:0% +Efficiency programs we also have + + + align:start position:0% +Efficiency programs we also have +subsidies for increasing the adoption of + + align:start position:0% +subsidies for increasing the adoption of + + + align:start position:0% +subsidies for increasing the adoption of +best available Technologies we have a + + align:start position:0% +best available Technologies we have a + + + align:start position:0% +best available Technologies we have a +low carbon technology roadmap relative + + align:start position:0% +low carbon technology roadmap relative + + + align:start position:0% +low carbon technology roadmap relative +to steel + + align:start position:0% +to steel + + + align:start position:0% +to steel +I think we have that in our new + + align:start position:0% +I think we have that in our new + + + align:start position:0% +I think we have that in our new +inflation reduction acts legislation we + + align:start position:0% +inflation reduction acts legislation we + + + align:start position:0% +inflation reduction acts legislation we +definitely have road maps for low carbon + + align:start position:0% +definitely have road maps for low carbon + + + align:start position:0% +definitely have road maps for low carbon +production of industrial production + + align:start position:0% +production of industrial production + + + align:start position:0% +production of industrial production +and finally the energy star program for + + align:start position:0% +and finally the energy star program for + + + align:start position:0% +and finally the energy star program for +industry for adopting energy efficient + + align:start position:0% +industry for adopting energy efficient + + + align:start position:0% +industry for adopting energy efficient +Technologies this is really a U.S level + + align:start position:0% +Technologies this is really a U.S level + + + align:start position:0% +Technologies this is really a U.S level +policy but as I spoke to you about + + align:start position:0% +policy but as I spoke to you about + + + align:start position:0% +policy but as I spoke to you about +benchmarking benchmarking is essentially + + align:start position:0% +benchmarking benchmarking is essentially + + + align:start position:0% +benchmarking benchmarking is essentially +built on energy star we have bench + + align:start position:0% +built on energy star we have bench + + + align:start position:0% +built on energy star we have bench +marketing programs to encourage adopting + + align:start position:0% +marketing programs to encourage adopting + + + align:start position:0% +marketing programs to encourage adopting +Energy Technologies and buildings and so + + align:start position:0% +Energy Technologies and buildings and so + + + align:start position:0% +Energy Technologies and buildings and so +on now what the interesting part for + + align:start position:0% +on now what the interesting part for + + + align:start position:0% +on now what the interesting part for +cities and Industrial missions is the + + align:start position:0% +cities and Industrial missions is the + + + align:start position:0% +cities and Industrial missions is the +policy that exists in developing + + align:start position:0% +policy that exists in developing + + + align:start position:0% +policy that exists in developing +countries and arguably could be applied + + align:start position:0% +countries and arguably could be applied + + + align:start position:0% +countries and arguably could be applied +to cities that are producing a lot of + + align:start position:0% +to cities that are producing a lot of + + + align:start position:0% +to cities that are producing a lot of +inductions like we talked about + + align:start position:0% +inductions like we talked about + + + align:start position:0% +inductions like we talked about +Louisiana Texas and Virginia and other + + align:start position:0% +Louisiana Texas and Virginia and other + + + align:start position:0% +Louisiana Texas and Virginia and other +parts of the country + + align:start position:0% +parts of the country + + + align:start position:0% +parts of the country +we have major programs the Energy + + align:start position:0% +we have major programs the Energy + + + align:start position:0% +we have major programs the Energy +Efficiency in industry in China we have + + align:start position:0% +Efficiency in industry in China we have + + + align:start position:0% +Efficiency in industry in China we have +mandated phase out of outdated backward + + align:start position:0% +mandated phase out of outdated backward + + + align:start position:0% +mandated phase out of outdated backward +Industries we have pricing policies that + + align:start position:0% +Industries we have pricing policies that + + + align:start position:0% +Industries we have pricing policies that +favor Energy Efficiency and we have a + + align:start position:0% +favor Energy Efficiency and we have a + + + align:start position:0% +favor Energy Efficiency and we have a +major clean development mechanisms to + + align:start position:0% +major clean development mechanisms to + + + align:start position:0% +major clean development mechanisms to +help China basically phase out non-co2 + + align:start position:0% +help China basically phase out non-co2 + + + align:start position:0% +help China basically phase out non-co2 +gases + + align:start position:0% +gases + + + align:start position:0% +gases +we have other schemes in India and + + align:start position:0% +we have other schemes in India and + + + align:start position:0% +we have other schemes in India and +Brazil like such as sectoral plans for + + align:start position:0% +Brazil like such as sectoral plans for + + + align:start position:0% +Brazil like such as sectoral plans for +industry including energy conservation + + align:start position:0% +industry including energy conservation + + + align:start position:0% +industry including energy conservation +programs these are all things that can + + align:start position:0% +programs these are all things that can + + + align:start position:0% +programs these are all things that can +and are being applied to Industrial + + align:start position:0% +and are being applied to Industrial + + + align:start position:0% +and are being applied to Industrial +missions in cities that have more higher + + align:start position:0% +missions in cities that have more higher + + + align:start position:0% +missions in cities that have more higher +industrial missions + + align:start position:0% +industrial missions + + + align:start position:0% +industrial missions +this brings me to the wristman paper uh + + align:start position:0% +this brings me to the wristman paper uh + + + align:start position:0% +this brings me to the wristman paper uh +the Smith paper with many co-authors + + align:start position:0% +the Smith paper with many co-authors + + + align:start position:0% +the Smith paper with many co-authors +we're going to use this at the basis + + align:start position:0% +we're going to use this at the basis + + + align:start position:0% +we're going to use this at the basis +part of discussion on class in class and + + align:start position:0% +part of discussion on class in class and + + + align:start position:0% +part of discussion on class in class and +what I want to emphasize to you just + + align:start position:0% +what I want to emphasize to you just + + + align:start position:0% +what I want to emphasize to you just +that maybe a few points in the paper + + align:start position:0% +that maybe a few points in the paper + + + align:start position:0% +that maybe a few points in the paper +before we go into the discussion + + align:start position:0% +before we go into the discussion + + + align:start position:0% +before we go into the discussion +together I visited a figure showing + + align:start position:0% +together I visited a figure showing + + + align:start position:0% +together I visited a figure showing +emissions by sector the left-hand side + + align:start position:0% +emissions by sector the left-hand side + + + align:start position:0% +emissions by sector the left-hand side +has the kind of groupings by sector + + align:start position:0% +has the kind of groupings by sector + + + align:start position:0% +has the kind of groupings by sector +including let's say for buildings + + align:start position:0% +including let's say for buildings + + + align:start position:0% +including let's say for buildings +indirect and direct energy related + + align:start position:0% +indirect and direct energy related + + + align:start position:0% +indirect and direct energy related +emissions is 24 of the heat and + + align:start position:0% +emissions is 24 of the heat and + + + align:start position:0% +emissions is 24 of the heat and +electricity emissions this aggregated if + + align:start position:0% +electricity emissions this aggregated if + + + align:start position:0% +electricity emissions this aggregated if +we group eat electricity and heat + + align:start position:0% +we group eat electricity and heat + + + align:start position:0% +we group eat electricity and heat +emissions together buildings only seem + + align:start position:0% +emissions together buildings only seem + + + align:start position:0% +emissions together buildings only seem +to be about eight percent but this is a + + align:start position:0% +to be about eight percent but this is a + + + align:start position:0% +to be about eight percent but this is a +considerable Divergence from where we + + align:start position:0% +considerable Divergence from where we + + + align:start position:0% +considerable Divergence from where we +started the lecture from in other words + + align:start position:0% +started the lecture from in other words + + + align:start position:0% +started the lecture from in other words +buildings consume a very large portion + + align:start position:0% +buildings consume a very large portion + + + align:start position:0% +buildings consume a very large portion +of energy in this disaggregated view of + + align:start position:0% +of energy in this disaggregated view of + + + align:start position:0% +of energy in this disaggregated view of +both heat and electricity emissions if + + align:start position:0% +both heat and electricity emissions if + + + align:start position:0% +both heat and electricity emissions if +we group it together then we kind of + + align:start position:0% +we group it together then we kind of + + + align:start position:0% +we group it together then we kind of +hide some of the building emissions in + + align:start position:0% +hide some of the building emissions in + + + align:start position:0% +hide some of the building emissions in +the power sector + + align:start position:0% +the power sector + + + align:start position:0% +the power sector +but if we look specifically at how much + + align:start position:0% +but if we look specifically at how much + + + align:start position:0% +but if we look specifically at how much +energy or how much emissions are + + align:start position:0% +energy or how much emissions are + + + align:start position:0% +energy or how much emissions are +associated with different sectors by + + align:start position:0% +associated with different sectors by + + + align:start position:0% +associated with different sectors by +industry you can see the number uh two + + align:start position:0% +industry you can see the number uh two + + + align:start position:0% +industry you can see the number uh two +or three are iron steel chemicals and + + align:start position:0% +or three are iron steel chemicals and + + + align:start position:0% +or three are iron steel chemicals and +Plastics and cement aluminum refining + + align:start position:0% +Plastics and cement aluminum refining + + + align:start position:0% +Plastics and cement aluminum refining +Machinery open paper all of these + + align:start position:0% +Machinery open paper all of these + + + align:start position:0% +Machinery open paper all of these +various manufacturing or production + + align:start position:0% +various manufacturing or production + + + align:start position:0% +various manufacturing or production +activities result in High Ground stats + + align:start position:0% +activities result in High Ground stats + + + align:start position:0% +activities result in High Ground stats +emissions these are a significant + + align:start position:0% +emissions these are a significant + + + align:start position:0% +emissions these are a significant +fraction of the world's freonounced gas + + align:start position:0% +fraction of the world's freonounced gas + + + align:start position:0% +fraction of the world's freonounced gas +emissions we've been talking about + + align:start position:0% +emissions we've been talking about + + + align:start position:0% +emissions we've been talking about +so we'll talk about in our class + + align:start position:0% +so we'll talk about in our class + + + align:start position:0% +so we'll talk about in our class +discussion are various policies + + align:start position:0% +discussion are various policies + + + align:start position:0% +discussion are various policies +interventions on the supply side some of + + align:start position:0% +interventions on the supply side some of + + + align:start position:0% +interventions on the supply side some of +the ones that students were interested + + align:start position:0% +the ones that students were interested + + + align:start position:0% +the ones that students were interested +last year were carbon capture + + align:start position:0% +last year were carbon capture + + + align:start position:0% +last year were carbon capture +utilization storage low carbon + + align:start position:0% +utilization storage low carbon + + + align:start position:0% +utilization storage low carbon +development for developing countries how + + align:start position:0% +development for developing countries how + + + align:start position:0% +development for developing countries how +could we apply that to cities worker + + align:start position:0% +could we apply that to cities worker + + + align:start position:0% +could we apply that to cities worker +retraining programs firms influencing + + align:start position:0% +retraining programs firms influencing + + + align:start position:0% +retraining programs firms influencing +government decisions low carbon steel + + align:start position:0% +government decisions low carbon steel + + + align:start position:0% +government decisions low carbon steel +production electrolysis renewable energy + + align:start position:0% +production electrolysis renewable energy + + + align:start position:0% +production electrolysis renewable energy +production electrication hydrogen + + align:start position:0% +production electrication hydrogen + + + align:start position:0% +production electrication hydrogen +production use on the demand side + + align:start position:0% +production use on the demand side + + + align:start position:0% +production use on the demand side +students discuss last year material + + align:start position:0% +students discuss last year material + + + align:start position:0% +students discuss last year material +substitution material efficiency reduce + + align:start position:0% +substitution material efficiency reduce + + + align:start position:0% +substitution material efficiency reduce +material use pairing of public goods + + align:start position:0% +material use pairing of public goods + + + align:start position:0% +material use pairing of public goods +efficiency standards the circular + + align:start position:0% +efficiency standards the circular + + + align:start position:0% +efficiency standards the circular +economy the data transparency and of + + align:start position:0% +economy the data transparency and of + + + align:start position:0% +economy the data transparency and of +course building codes + + align:start position:0% +course building codes + + + align:start position:0% +course building codes +thank you very much I look forward to + + align:start position:0% +thank you very much I look forward to + + + align:start position:0% +thank you very much I look forward to +our discussion and class in person \ No newline at end of file diff --git a/aSk7YbhON_0.txt b/aSk7YbhON_0.txt new file mode 100644 index 0000000000000000000000000000000000000000..a8210dea7bb30bb98d4864fd68ef889607d8c661 --- /dev/null +++ b/aSk7YbhON_0.txt @@ -0,0 +1,1251 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT OpenCourseWare continue to + + align:start position:0% +will help MIT OpenCourseWare continue to + + + align:start position:0% +will help MIT OpenCourseWare continue to +offer high quality educational resources + + align:start position:0% +offer high quality educational resources + + + align:start position:0% +offer high quality educational resources +for free + + align:start position:0% +for free + + + align:start position:0% +for free +to make a donation or to view additional + + align:start position:0% +to make a donation or to view additional + + + align:start position:0% +to make a donation or to view additional +materials from hundreds of MIT courses + + align:start position:0% +materials from hundreds of MIT courses + + + align:start position:0% +materials from hundreds of MIT courses +visit MIT opencourseware at ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +about students at MIT so some of you are + + align:start position:0% +about students at MIT so some of you are + + + align:start position:0% +about students at MIT so some of you are +graduating soon and this may be your + + align:start position:0% +graduating soon and this may be your + + + align:start position:0% +graduating soon and this may be your +last chance to ask so well what you do + + align:start position:0% +last chance to ask so well what you do + + + align:start position:0% +last chance to ask so well what you do +that's on you speak up and we have a lot + + align:start position:0% +that's on you speak up and we have a lot + + + align:start position:0% +that's on you speak up and we have a lot +of freedom if we use it in fact a lot + + align:start position:0% +of freedom if we use it in fact a lot + + + align:start position:0% +of freedom if we use it in fact a lot +more than in the past + + align:start position:0% +more than in the past + + + align:start position:0% +more than in the past +so safer take the last thing I mentioned + + align:start position:0% +so safer take the last thing I mentioned + + + align:start position:0% +so safer take the last thing I mentioned +for women of the opportunities to speak + + align:start position:0% +for women of the opportunities to speak + + + align:start position:0% +for women of the opportunities to speak +up and become active and have an impact + + align:start position:0% +up and become active and have an impact + + + align:start position:0% +up and become active and have an impact +is way beyond what it was say fifty + + align:start position:0% +is way beyond what it was say fifty + + + align:start position:0% +is way beyond what it was say fifty +years ago in fact it's talking to me all + + align:start position:0% +years ago in fact it's talking to me all + + + align:start position:0% +years ago in fact it's talking to me all +about this before when every I got a ton + + align:start position:0% +about this before when every I got a ton + + + align:start position:0% +about this before when every I got a ton +of email and a lot of it is from young + + align:start position:0% +of email and a lot of it is from young + + + align:start position:0% +of email and a lot of it is from young +people and one question that keeps + + align:start position:0% +people and one question that keeps + + + align:start position:0% +people and one question that keeps +coming up over and over again is you + + align:start position:0% +coming up over and over again is you + + + align:start position:0% +coming up over and over again is you +know everything's awful what can we do + + align:start position:0% +know everything's awful what can we do + + + align:start position:0% +know everything's awful what can we do +but if you look closely over many years + + align:start position:0% +but if you look closely over many years + + + align:start position:0% +but if you look closely over many years +I've noticed that the kinds of questions + + align:start position:0% +I've noticed that the kinds of questions + + + align:start position:0% +I've noticed that the kinds of questions +you get depend on where the people are + + align:start position:0% +you get depend on where the people are + + + align:start position:0% +you get depend on where the people are +coming from so if people are coming from + + align:start position:0% +coming from so if people are coming from + + + align:start position:0% +coming from so if people are coming from +say when I go down to give talks and the + + align:start position:0% +say when I go down to give talks and the + + + align:start position:0% +say when I go down to give talks and the +immigrants lumps in south los and nobody + + align:start position:0% +immigrants lumps in south los and nobody + + + align:start position:0% +immigrants lumps in south los and nobody +ever asks what they can do they tell me + + align:start position:0% +ever asks what they can do they tell me + + + align:start position:0% +ever asks what they can do they tell me +what they're doing + + align:start position:0% +what they're doing + + + align:start position:0% +what they're doing +I go to remote village in southern + + align:start position:0% +I go to remote village in southern + + + align:start position:0% +I go to remote village in southern +Colombia where people are being murdered + + align:start position:0% +Colombia where people are being murdered + + + align:start position:0% +Colombia where people are being murdered +by paramilitaries and there's a chemical + + align:start position:0% +by paramilitaries and there's a chemical + + + align:start position:0% +by paramilitaries and there's a chemical +company trying to the gold mining + + align:start position:0% +company trying to the gold mining + + + align:start position:0% +company trying to the gold mining +company trying to destroy their water + + align:start position:0% +company trying to destroy their water + + + align:start position:0% +company trying to destroy their water +supply they don't ask me what it what + + align:start position:0% +supply they don't ask me what it what + + + align:start position:0% +supply they don't ask me what it what +should they do they tell me what they're + + align:start position:0% +should they do they tell me what they're + + + align:start position:0% +should they do they tell me what they're +doing when people are privileged and + + align:start position:0% +doing when people are privileged and + + + align:start position:0% +doing when people are privileged and +have every opportunity in front of them + + align:start position:0% +have every opportunity in front of them + + + align:start position:0% +have every opportunity in front of them +they asked what what can we do and the + + align:start position:0% +they asked what what can we do and the + + + align:start position:0% +they asked what what can we do and the +fact is almost anything there's all + + align:start position:0% +fact is almost anything there's all + + + align:start position:0% +fact is almost anything there's all +sorts of opportunities of way more than + + align:start position:0% +sorts of opportunities of way more than + + + align:start position:0% +sorts of opportunities of way more than +there were in the past because we do + + align:start position:0% +there were in the past because we do + + + align:start position:0% +there were in the past because we do +enjoy the legacy of people who have + + align:start position:0% +enjoy the legacy of people who have + + + align:start position:0% +enjoy the legacy of people who have +struggled in the past under much harsher + + align:start position:0% +struggled in the past under much harsher + + + align:start position:0% +struggled in the past under much harsher +conditions and have provided us with the + + align:start position:0% +conditions and have provided us with the + + + align:start position:0% +conditions and have provided us with the +opportunities we now have like say the + + align:start position:0% +opportunities we now have like say the + + + align:start position:0% +opportunities we now have like say the +opportunity is to be a student at MIT + + align:start position:0% +opportunity is to be a student at MIT + + + align:start position:0% +opportunity is to be a student at MIT +that's an opportunity gives you all + + align:start position:0% +that's an opportunity gives you all + + + align:start position:0% +that's an opportunity gives you all +sorts of things it was close to half the + + align:start position:0% +sorts of things it was close to half the + + + align:start position:0% +sorts of things it was close to half the +population fifty years ago it was closed + + align:start position:0% +population fifty years ago it was closed + + + align:start position:0% +population fifty years ago it was closed +of course to minorities almost entirely + + align:start position:0% +of course to minorities almost entirely + + + align:start position:0% +of course to minorities almost entirely +and well that's that's just illustrates + + align:start position:0% +and well that's that's just illustrates + + + align:start position:0% +and well that's that's just illustrates +what's going on all over the society so + + align:start position:0% +what's going on all over the society so + + + align:start position:0% +what's going on all over the society so +this I mean that takes a the thing the + + align:start position:0% +this I mean that takes a the thing the + + + align:start position:0% +this I mean that takes a the thing the +Sanders campaign reason which I think + + align:start position:0% +Sanders campaign reason which I think + + + align:start position:0% +Sanders campaign reason which I think +was the most important aspect of the + + align:start position:0% +was the most important aspect of the + + + align:start position:0% +was the most important aspect of the +2016 election by far out of that there + + align:start position:0% +2016 election by far out of that there + + + align:start position:0% +2016 election by far out of that there +are groups developing that are really + + align:start position:0% +are groups developing that are really + + + align:start position:0% +are groups developing that are really +trying to do things to be part of them + + align:start position:0% +trying to do things to be part of them + + + align:start position:0% +trying to do things to be part of them +make new ones + + align:start position:0% +make new ones + + + align:start position:0% +make new ones +there's any kind of other all sorts of + + align:start position:0% +there's any kind of other all sorts of + + + align:start position:0% +there's any kind of other all sorts of +opportunities and I think the prospects + + align:start position:0% +opportunities and I think the prospects + + + align:start position:0% +opportunities and I think the prospects +for the future are not too bad when you + + align:start position:0% +for the future are not too bad when you + + + align:start position:0% +for the future are not too bad when you +think of people's attitude actual + + align:start position:0% +think of people's attitude actual + + + align:start position:0% +think of people's attitude actual +attitudes and the way those attitudes + + align:start position:0% +attitudes and the way those attitudes + + + align:start position:0% +attitudes and the way those attitudes +can be melded into activists and + + align:start position:0% +can be melded into activists and + + + align:start position:0% +can be melded into activists and +political and other programs to bring + + align:start position:0% +political and other programs to bring + + + align:start position:0% +political and other programs to bring +about changes in the society I don't + + align:start position:0% +about changes in the society I don't + + + align:start position:0% +about changes in the society I don't +think there's a real shortage of + + align:start position:0% +think there's a real shortage of + + + align:start position:0% +think there's a real shortage of +opportunity that there's a you know + + align:start position:0% +opportunity that there's a you know + + + align:start position:0% +opportunity that there's a you know +there's a kind of it there all sorts of + + align:start position:0% +there's a kind of it there all sorts of + + + align:start position:0% +there's a kind of it there all sorts of +efforts to atomize people keep you alone + + align:start position:0% +efforts to atomize people keep you alone + + + align:start position:0% +efforts to atomize people keep you alone +that's one of the functions of social + + align:start position:0% +that's one of the functions of social + + + align:start position:0% +that's one of the functions of social +media incidentally you sit alone with + + align:start position:0% +media incidentally you sit alone with + + + align:start position:0% +media incidentally you sit alone with +your you know your whatever it is device + + align:start position:0% +your you know your whatever it is device + + + align:start position:0% +your you know your whatever it is device +you know and you think you have friends + + align:start position:0% +you know and you think you have friends + + + align:start position:0% +you know and you think you have friends +and Indonesian but you're really + + align:start position:0% +and Indonesian but you're really + + + align:start position:0% +and Indonesian but you're really +separated from the people around you + + align:start position:0% +separated from the people around you + + + align:start position:0% +separated from the people around you +that has a atomization is a very + + align:start position:0% +that has a atomization is a very + + + align:start position:0% +that has a atomization is a very +important way of controlling people but + + align:start position:0% +important way of controlling people but + + + align:start position:0% +important way of controlling people but +you can only do things if you work + + align:start position:0% +you can only do things if you work + + + align:start position:0% +you can only do things if you work +together so when you're all separated + + align:start position:0% +together so when you're all separated + + + align:start position:0% +together so when you're all separated +that's great then those who really run + + align:start position:0% +that's great then those who really run + + + align:start position:0% +that's great then those who really run +things they do get together they don't + + align:start position:0% +things they do get together they don't + + + align:start position:0% +things they do get together they don't +sit around looking at iPads so you can + + align:start position:0% +sit around looking at iPads so you can + + + align:start position:0% +sit around looking at iPads so you can +keep the population in fact that's what + + align:start position:0% +keep the population in fact that's what + + + align:start position:0% +keep the population in fact that's what +one of the main things consumerism is + + align:start position:0% +one of the main things consumerism is + + + align:start position:0% +one of the main things consumerism is +about you take a look at the history the + + align:start position:0% +about you take a look at the history the + + + align:start position:0% +about you take a look at the history the +advertising industry it's quite + + align:start position:0% +advertising industry it's quite + + + align:start position:0% +advertising industry it's quite +interesting the huge advertising public + + align:start position:0% +interesting the huge advertising public + + + align:start position:0% +interesting the huge advertising public +relations industry developed in the + + align:start position:0% +relations industry developed in the + + + align:start position:0% +relations industry developed in the +freest countries in the world in Britain + + align:start position:0% +freest countries in the world in Britain + + + align:start position:0% +freest countries in the world in Britain +in the United States out of century ago + + align:start position:0% +in the United States out of century ago + + + align:start position:0% +in the United States out of century ago +and the reason was pretty clear was + + align:start position:0% +and the reason was pretty clear was + + + align:start position:0% +and the reason was pretty clear was +often stated people had won enough + + align:start position:0% +often stated people had won enough + + + align:start position:0% +often stated people had won enough +freedom so that you couldn't control + + align:start position:0% +freedom so that you couldn't control + + + align:start position:0% +freedom so that you couldn't control +them by force so you had to control them + + align:start position:0% +them by force so you had to control them + + + align:start position:0% +them by force so you had to control them +in other ways and the best way of + + align:start position:0% +in other ways and the best way of + + + align:start position:0% +in other ways and the best way of +controlling them is what was called + + align:start position:0% + + + + align:start position:0% + +convincing them to be concerned with the + + align:start position:0% +convincing them to be concerned with the + + + align:start position:0% +convincing them to be concerned with the +superficial things of life like + + align:start position:0% +superficial things of life like + + + align:start position:0% +superficial things of life like +consumption so if you can get to a stage + + align:start position:0% +consumption so if you can get to a stage + + + align:start position:0% +consumption so if you can get to a stage +where I think it of my granddaughter + + align:start position:0% +where I think it of my granddaughter + + + align:start position:0% +where I think it of my granddaughter +we're teenage girls on a Saturday + + align:start position:0% +we're teenage girls on a Saturday + + + align:start position:0% +we're teenage girls on a Saturday +afternoon the best thing they can think + + align:start position:0% +afternoon the best thing they can think + + + align:start position:0% +afternoon the best thing they can think +of doing is walking through a mall and + + align:start position:0% +of doing is walking through a mall and + + + align:start position:0% +of doing is walking through a mall and +looking at things they can't buy and you + + align:start position:0% +looking at things they can't buy and you + + + align:start position:0% +looking at things they can't buy and you +know that's great too when you've got + + align:start position:0% +know that's great too when you've got + + + align:start position:0% +know that's great too when you've got +get to a society like that and you've + + align:start position:0% +get to a society like that and you've + + + align:start position:0% +get to a society like that and you've +got people under control and there's + + align:start position:0% +got people under control and there's + + + align:start position:0% +got people under control and there's +some pretty obvious things that are + + align:start position:0% +some pretty obvious things that are + + + align:start position:0% +some pretty obvious things that are +never discussed like you've all heard + + align:start position:0% +never discussed like you've all heard + + + align:start position:0% +never discussed like you've all heard +ten million times about the wonders of + + align:start position:0% +ten million times about the wonders of + + + align:start position:0% +ten million times about the wonders of +free market societies but almost no one + + align:start position:0% +free market societies but almost no one + + + align:start position:0% +free market societies but almost no one +tells you that the business world hates + + align:start position:0% +tells you that the business world hates + + + align:start position:0% +tells you that the business world hates +free market societies and in fact they + + align:start position:0% +free market societies and in fact they + + + align:start position:0% +free market societies and in fact they +spend hundreds of billion dollars a year + + align:start position:0% +spend hundreds of billion dollars a year + + + align:start position:0% +spend hundreds of billion dollars a year +to undermine markets it's called + + align:start position:0% +to undermine markets it's called + + + align:start position:0% +to undermine markets it's called +advertising anyone who's studied + + align:start position:0% +advertising anyone who's studied + + + align:start position:0% +advertising anyone who's studied +economics knows that markets the marvels + + align:start position:0% +economics knows that markets the marvels + + + align:start position:0% +economics knows that markets the marvels +of markets are based on informed + + align:start position:0% +of markets are based on informed + + + align:start position:0% +of markets are based on informed +consumers making rational choices that's + + align:start position:0% +consumers making rational choices that's + + + align:start position:0% +consumers making rational choices that's +what you study the mathematics and you + + align:start position:0% +what you study the mathematics and you + + + align:start position:0% +what you study the mathematics and you +make up the models and so on take a look + + align:start position:0% +make up the models and so on take a look + + + align:start position:0% +make up the models and so on take a look +at the real world hundreds of billions + + align:start position:0% +at the real world hundreds of billions + + + align:start position:0% +at the real world hundreds of billions +of dollars are spent every year to + + align:start position:0% +of dollars are spent every year to + + + align:start position:0% +of dollars are spent every year to +ensure that uninformed people make + + align:start position:0% +ensure that uninformed people make + + + align:start position:0% +ensure that uninformed people make +irrational choices + + align:start position:0% +irrational choices + + + align:start position:0% +irrational choices +that's called advertising and if you had + + align:start position:0% +that's called advertising and if you had + + + align:start position:0% +that's called advertising and if you had +a market society if say Ford Motor + + align:start position:0% +a market society if say Ford Motor + + + align:start position:0% +a market society if say Ford Motor +Company has cars to sell what they would + + align:start position:0% +Company has cars to sell what they would + + + align:start position:0% +Company has cars to sell what they would +do is say here are the characteristics + + align:start position:0% +do is say here are the characteristics + + + align:start position:0% +do is say here are the characteristics +of our cars you know small ad on + + align:start position:0% +of our cars you know small ad on + + + align:start position:0% +of our cars you know small ad on +television says here's the + + align:start position:0% +television says here's the + + + align:start position:0% +television says here's the +characteristics here's what consumer + + align:start position:0% +characteristics here's what consumer + + + align:start position:0% +characteristics here's what consumer +report says about it you know that's not + + align:start position:0% +report says about it you know that's not + + + align:start position:0% +report says about it you know that's not +what they do what they do is try to + + align:start position:0% +what they do what they do is try to + + + align:start position:0% +what they do what they do is try to +create illusions so you will be + + align:start position:0% +create illusions so you will be + + + align:start position:0% +create illusions so you will be +uninformed and make an irrational choice + + align:start position:0% +uninformed and make an irrational choice + + + align:start position:0% +uninformed and make an irrational choice +in fact while the Economics Department + + align:start position:0% +in fact while the Economics Department + + + align:start position:0% +in fact while the Economics Department +is talking about rational choice models + + align:start position:0% +is talking about rational choice models + + + align:start position:0% +is talking about rational choice models +and so on with informed consumers the + + align:start position:0% +and so on with informed consumers the + + + align:start position:0% +and so on with informed consumers the +business world is trying to make sure it + + align:start position:0% +business world is trying to make sure it + + + align:start position:0% +business world is trying to make sure it +doesn't happen and of course that's the + + align:start position:0% +doesn't happen and of course that's the + + + align:start position:0% +doesn't happen and of course that's the +thing that has the effect + + align:start position:0% +thing that has the effect + + + align:start position:0% +thing that has the effect +speaking of silencing and how much you + + align:start position:0% +speaking of silencing and how much you + + + align:start position:0% +speaking of silencing and how much you +hear about this in economics person or + + align:start position:0% +hear about this in economics person or + + + align:start position:0% +hear about this in economics person or +in the general discussion I mean it's + + align:start position:0% +in the general discussion I mean it's + + + align:start position:0% +in the general discussion I mean it's +not deep it's not profound it's not + + align:start position:0% +not deep it's not profound it's not + + + align:start position:0% +not deep it's not profound it's not +quantum physics we don't know it's right + + align:start position:0% +quantum physics we don't know it's right + + + align:start position:0% +quantum physics we don't know it's right +in front of your eyes but it's kept + + align:start position:0% +in front of your eyes but it's kept + + + align:start position:0% +in front of your eyes but it's kept +silent those are the kind of things you + + align:start position:0% +silent those are the kind of things you + + + align:start position:0% +silent those are the kind of things you +have to break through thank you so much + + align:start position:0% + + + + align:start position:0% + +[Applause] \ No newline at end of file diff --git a/aewmVftXm1Q.txt b/aewmVftXm1Q.txt new file mode 100644 index 0000000000000000000000000000000000000000..8bf6665b4985237618374509167556d46b02ee5e --- /dev/null +++ b/aewmVftXm1Q.txt @@ -0,0 +1,2203 @@ +align:start position:0% + +the first step of making architecture is + + align:start position:0% +the first step of making architecture is + + + align:start position:0% +the first step of making architecture is +to visit the + + align:start position:0% +to visit the + + + align:start position:0% +to visit the +site it's the site that gives us Clues + + align:start position:0% +site it's the site that gives us Clues + + + align:start position:0% +site it's the site that gives us Clues +as to how to design of course we have a + + align:start position:0% +as to how to design of course we have a + + + align:start position:0% +as to how to design of course we have a +program and we have thoughts about + + align:start position:0% +program and we have thoughts about + + + align:start position:0% +program and we have thoughts about +form but it's really the site that is + + align:start position:0% +form but it's really the site that is + + + align:start position:0% +form but it's really the site that is +the most important at the beginning + + align:start position:0% +the most important at the beginning + + + align:start position:0% +the most important at the beginning +stage in fact we should know the site as + + align:start position:0% +stage in fact we should know the site as + + + align:start position:0% +stage in fact we should know the site as +well as we know our own + + align:start position:0% +well as we know our own + + + align:start position:0% +well as we know our own +backyard the site is our friend for the + + align:start position:0% +backyard the site is our friend for the + + + align:start position:0% +backyard the site is our friend for the +whole process of + + align:start position:0% +whole process of + + + align:start position:0% +whole process of +Designing is what we should keep + + align:start position:0% +Designing is what we should keep + + + align:start position:0% +Designing is what we should keep +returning to keep understanding seeing + + align:start position:0% +returning to keep understanding seeing + + + align:start position:0% +returning to keep understanding seeing +uh during the day at night uh in the + + align:start position:0% +uh during the day at night uh in the + + + align:start position:0% +uh during the day at night uh in the +rain and the Sun It's The Giver of the + + align:start position:0% +rain and the Sun It's The Giver of the + + + align:start position:0% +rain and the Sun It's The Giver of the +original + + align:start position:0% + + + + align:start position:0% + +ideas uh of course uh the program and + + align:start position:0% +ideas uh of course uh the program and + + + align:start position:0% +ideas uh of course uh the program and +the forums and all the rest of important + + align:start position:0% +the forums and all the rest of important + + + align:start position:0% +the forums and all the rest of important +but it's the site that + + align:start position:0% +but it's the site that + + + align:start position:0% +but it's the site that +starts so what you're about to see is a + + align:start position:0% +starts so what you're about to see is a + + + align:start position:0% +starts so what you're about to see is a +site visit to the North + + align:start position:0% +site visit to the North + + + align:start position:0% +site visit to the North +End which is where we're doing a project + + align:start position:0% +End which is where we're doing a project + + + align:start position:0% +End which is where we're doing a project +for design of a + + align:start position:0% +for design of a + + + align:start position:0% +for design of a +house um on the sides of buildings and + + align:start position:0% +house um on the sides of buildings and + + + align:start position:0% +house um on the sides of buildings and +on the roofs of the buildings and then + + align:start position:0% +on the roofs of the buildings and then + + + align:start position:0% +on the roofs of the buildings and then +later in the same area the same site we + + align:start position:0% +later in the same area the same site we + + + align:start position:0% +later in the same area the same site we +will be designing a community + + align:start position:0% +will be designing a community + + + align:start position:0% +will be designing a community +place so the following is that first + + align:start position:0% +place so the following is that first + + + align:start position:0% +place so the following is that first +visit to the site + + align:start position:0% + + + + align:start position:0% + +what do you + + align:start position:0% + + + + align:start position:0% + +think huh challenging you can see the + + align:start position:0% +think huh challenging you can see the + + + align:start position:0% +think huh challenging you can see the +church from here the Nave of it through + + align:start position:0% +church from here the Nave of it through + + + align:start position:0% +church from here the Nave of it through +there yeah I think if you knocked on the + + align:start position:0% +there yeah I think if you knocked on the + + + align:start position:0% +there yeah I think if you knocked on the +door and you know you probably see the + + align:start position:0% +door and you know you probably see the + + + align:start position:0% +door and you know you probably see the +inside of that + + align:start position:0% +inside of that + + + align:start position:0% +inside of that +window uh there's a church and Monastery + + align:start position:0% +window uh there's a church and Monastery + + + align:start position:0% +window uh there's a church and Monastery +or school there I think I think it's + + align:start position:0% +or school there I think I think it's + + + align:start position:0% +or school there I think I think it's +connected and of course you're on the + + align:start position:0% +connected and of course you're on the + + + align:start position:0% +connected and of course you're on the +roof of it you got to attach yourself to + + align:start position:0% +roof of it you got to attach yourself to + + + align:start position:0% +roof of it you got to attach yourself to +the side of that a little bit + + align:start position:0% +the side of that a little bit + + + align:start position:0% +the side of that a little bit +then so it's going to be hanging off and + + align:start position:0% +then so it's going to be hanging off and + + + align:start position:0% +then so it's going to be hanging off and +we do have to think about how structure + + align:start position:0% +we do have to think about how structure + + + align:start position:0% +we do have to think about how structure +is going to work in some general way and + + align:start position:0% +is going to work in some general way and + + + align:start position:0% +is going to work in some general way and +we'll get David Whitney back sometimes + + align:start position:0% +we'll get David Whitney back sometimes + + + align:start position:0% +we'll get David Whitney back sometimes +you're going to Candle leave out + + align:start position:0% +you're going to Candle leave out + + + align:start position:0% +you're going to Candle leave out +sometimes they going to be braces you + + align:start position:0% +sometimes they going to be braces you + + + align:start position:0% +sometimes they going to be braces you +could run things down to the ground you + + align:start position:0% +could run things down to the ground you + + + align:start position:0% +could run things down to the ground you +have no + + align:start position:0% +have no + + + align:start position:0% +have no +um uh limitations of what you can do but + + align:start position:0% +um uh limitations of what you can do but + + + align:start position:0% +um uh limitations of what you can do but +we do want to be structural you could + + align:start position:0% +we do want to be structural you could + + + align:start position:0% +we do want to be structural you could +hang over the side and structurally it + + align:start position:0% +hang over the side and structurally it + + + align:start position:0% +hang over the side and structurally it +would hold on you know uh for instance + + align:start position:0% +would hold on you know uh for instance + + + align:start position:0% +would hold on you know uh for instance +who has the vent site that two vents but + + align:start position:0% +who has the vent site that two vents but + + + align:start position:0% +who has the vent site that two vents but +the one that hangs over okay both of + + align:start position:0% +the one that hangs over okay both of + + + align:start position:0% +the one that hangs over okay both of +them mine's on the the yours is on the + + align:start position:0% +them mine's on the the yours is on the + + + align:start position:0% +them mine's on the the yours is on the +side and one hangs over yeah so that one + + align:start position:0% +side and one hangs over yeah so that one + + + align:start position:0% +side and one hangs over yeah so that one +could hang over uh almost like a shelf + + align:start position:0% +could hang over uh almost like a shelf + + + align:start position:0% +could hang over uh almost like a shelf +coming over the other one is going to + + align:start position:0% +coming over the other one is going to + + + align:start position:0% +coming over the other one is going to +attach itself to the to the + + align:start position:0% +attach itself to the to the + + + align:start position:0% +attach itself to the to the +side um what can anybody see from here + + align:start position:0% +side um what can anybody see from here + + + align:start position:0% +side um what can anybody see from here +that relates to our + + align:start position:0% + + + + align:start position:0% + +problem say + + align:start position:0% + + + + align:start position:0% + +again right and we however later right + + align:start position:0% +again right and we however later right + + + align:start position:0% +again right and we however later right +across the street that's our job is + + align:start position:0% +across the street that's our job is + + + align:start position:0% +across the street that's our job is +design a place for us to be which would + + align:start position:0% +design a place for us to be which would + + + align:start position:0% +design a place for us to be which would +include a play could include a + + align:start position:0% +include a play could include a + + + align:start position:0% +include a play could include a +playground that's our site right here + + align:start position:0% +playground that's our site right here + + + align:start position:0% +playground that's our site right here +where that where that playground is is + + align:start position:0% +where that where that playground is is + + + align:start position:0% +where that where that playground is is +part of our site but also all that area + + align:start position:0% +part of our site but also all that area + + + align:start position:0% +part of our site but also all that area +in there and certainly this is a place + + align:start position:0% +in there and certainly this is a place + + + align:start position:0% +in there and certainly this is a place +also that that could be used that way uh + + align:start position:0% +also that that could be used that way uh + + + align:start position:0% +also that that could be used that way uh +this has a special meaning and that's + + align:start position:0% +this has a special meaning and that's + + + align:start position:0% +this has a special meaning and that's +part of your site cluing finding out why + + align:start position:0% +part of your site cluing finding out why + + + align:start position:0% +part of your site cluing finding out why +it's here why all the buildings are here + + align:start position:0% +it's here why all the buildings are here + + + align:start position:0% +it's here why all the buildings are here +for that matter what else do you see + + align:start position:0% +for that matter what else do you see + + + align:start position:0% +for that matter what else do you see +look around quick behind + + align:start position:0% +look around quick behind + + + align:start position:0% +look around quick behind +me huh yeah someone's done what we're + + align:start position:0% +me huh yeah someone's done what we're + + + align:start position:0% +me huh yeah someone's done what we're +doing very + + align:start position:0% +doing very + + + align:start position:0% +doing very +modestly uh they've added already in a + + align:start position:0% +modestly uh they've added already in a + + + align:start position:0% +modestly uh they've added already in a +way on top of the roof and on the side + + align:start position:0% +way on top of the roof and on the side + + + align:start position:0% +way on top of the roof and on the side +and on the side yeah so they've done + + align:start position:0% +and on the side yeah so they've done + + + align:start position:0% +and on the side yeah so they've done +sort of what we're doing but in a very + + align:start position:0% +sort of what we're doing but in a very + + + align:start position:0% +sort of what we're doing but in a very +conservative way I'm not suggesting you + + align:start position:0% +conservative way I'm not suggesting you + + + align:start position:0% +conservative way I'm not suggesting you +be conservative I do think if you went + + align:start position:0% +be conservative I do think if you went + + + align:start position:0% +be conservative I do think if you went +down to uh Paul Rivers's mall and uh go + + align:start position:0% +down to uh Paul Rivers's mall and uh go + + + align:start position:0% +down to uh Paul Rivers's mall and uh go +to the old North Church and look at that + + align:start position:0% +to the old North Church and look at that + + + align:start position:0% +to the old North Church and look at that +one that's hanging on the side it's more + + align:start position:0% +one that's hanging on the side it's more + + + align:start position:0% +one that's hanging on the side it's more +interesting + + align:start position:0% +interesting + + + align:start position:0% +interesting +architecture and it's interesting + + align:start position:0% +architecture and it's interesting + + + align:start position:0% +architecture and it's interesting +because I think it fits into the North + + align:start position:0% +because I think it fits into the North + + + align:start position:0% +because I think it fits into the North +End so part of the issue of this project + + align:start position:0% +End so part of the issue of this project + + + align:start position:0% +End so part of the issue of this project +like the Quarry is how you fit what + + align:start position:0% +like the Quarry is how you fit what + + + align:start position:0% +like the Quarry is how you fit what +you're doing into the context but now + + align:start position:0% +you're doing into the context but now + + + align:start position:0% +you're doing into the context but now +the context is different obviously but + + align:start position:0% +the context is different obviously but + + + align:start position:0% +the context is different obviously but +it doesn't mean it has to be brick and + + align:start position:0% +it doesn't mean it has to be brick and + + + align:start position:0% +it doesn't mean it has to be brick and +Clon or whatever we are sitting on the + + align:start position:0% +Clon or whatever we are sitting on the + + + align:start position:0% +Clon or whatever we are sitting on the +dock of the water of the old water I + + align:start position:0% +dock of the water of the old water I + + + align:start position:0% +dock of the water of the old water I +think somebody might find this out as + + align:start position:0% +think somebody might find this out as + + + align:start position:0% +think somebody might find this out as +far of your clue but this is the + + align:start position:0% +far of your clue but this is the + + + align:start position:0% +far of your clue but this is the +original site but the water was right + + align:start position:0% +original site but the water was right + + + align:start position:0% +original site but the water was right +there as you may know may I have that + + align:start position:0% +there as you may know may I have that + + + align:start position:0% +there as you may know may I have that +growing just for a second that's why + + align:start position:0% +growing just for a second that's why + + + align:start position:0% +growing just for a second that's why +this street is + + align:start position:0% +this street is + + + align:start position:0% +this street is +curved cuz that used to be the in fact I + + align:start position:0% +curved cuz that used to be the in fact I + + + align:start position:0% +curved cuz that used to be the in fact I +think it's still it says North Street + + align:start position:0% +think it's still it says North Street + + + align:start position:0% +think it's still it says North Street +was it was the original Street along the + + align:start position:0% +was it was the original Street along the + + + align:start position:0% +was it was the original Street along the +dock so this is all water this was solid + + align:start position:0% +dock so this is all water this was solid + + + align:start position:0% +dock so this is all water this was solid +as you know Boston over the years is + + align:start position:0% +as you know Boston over the years is + + + align:start position:0% +as you know Boston over the years is +filled in + + align:start position:0% +filled in + + + align:start position:0% +filled in +tremendously All Back Bay is is filled + + align:start position:0% +tremendously All Back Bay is is filled + + + align:start position:0% +tremendously All Back Bay is is filled +all South End is filled + + align:start position:0% +all South End is filled + + + align:start position:0% +all South End is filled +uh all of Cambridge is filled where we + + align:start position:0% +uh all of Cambridge is filled where we + + + align:start position:0% +uh all of Cambridge is filled where we +are is all filled also so it's a it's a + + align:start position:0% +are is all filled also so it's a it's a + + + align:start position:0% +are is all filled also so it's a it's a +habit of cities to do that to fill up + + align:start position:0% +habit of cities to do that to fill up + + + align:start position:0% +habit of cities to do that to fill up +the water what about the person that's + + align:start position:0% +the water what about the person that's + + + align:start position:0% +the water what about the person that's +got this one up + + align:start position:0% +got this one up + + + align:start position:0% +got this one up +here Phil philli he's got an interesting + + align:start position:0% +here Phil philli he's got an interesting + + + align:start position:0% +here Phil philli he's got an interesting +issue how does he do how does he make a + + align:start position:0% +issue how does he do how does he make a + + + align:start position:0% +issue how does he do how does he make a +form up there that relates to that + + align:start position:0% +form up there that relates to that + + + align:start position:0% +form up there that relates to that +little curve or does he that's a context + + align:start position:0% +little curve or does he that's a context + + + align:start position:0% +little curve or does he that's a context +issue just like the + + align:start position:0% +issue just like the + + + align:start position:0% +issue just like the +Quarry how does he what does he do but + + align:start position:0% +Quarry how does he what does he do but + + + align:start position:0% +Quarry how does he what does he do but +he could relate to to that and at the + + align:start position:0% +he could relate to to that and at the + + + align:start position:0% +he could relate to to that and at the +same time the top of it the sky form + + align:start position:0% +same time the top of it the sky form + + + align:start position:0% +same time the top of it the sky form +that we talk about could be something + + align:start position:0% +that we talk about could be something + + + align:start position:0% +that we talk about could be something +entirely + + align:start position:0% +entirely + + + align:start position:0% +entirely +different so it's the same issues as + + align:start position:0% +different so it's the same issues as + + + align:start position:0% +different so it's the same issues as +before land form but the land is up in + + align:start position:0% +before land form but the land is up in + + + align:start position:0% +before land form but the land is up in +the sky and the middle and the sky and + + align:start position:0% +the sky and the middle and the sky and + + + align:start position:0% +the sky and the middle and the sky and +the sky can be something quite different + + align:start position:0% +the sky can be something quite different + + + align:start position:0% +the sky can be something quite different +doesn't have to be the + + align:start position:0% +doesn't have to be the + + + align:start position:0% +doesn't have to be the +same what I don't want you to do is to + + align:start position:0% +same what I don't want you to do is to + + + align:start position:0% +same what I don't want you to do is to +try to as in the Quarry imitate the + + align:start position:0% +try to as in the Quarry imitate the + + + align:start position:0% +try to as in the Quarry imitate the +context we are trying to add something + + align:start position:0% +context we are trying to add something + + + align:start position:0% +context we are trying to add something +that relates but not necessarily the + + align:start position:0% +that relates but not necessarily the + + + align:start position:0% +that relates but not necessarily the +same otherwise you end up with a little + + align:start position:0% +same otherwise you end up with a little + + + align:start position:0% +same otherwise you end up with a little +kind of Walt Disney Colonial whatever + + align:start position:0% +kind of Walt Disney Colonial whatever + + + align:start position:0% +kind of Walt Disney Colonial whatever +stuff which is not the issue but it does + + align:start position:0% +stuff which is not the issue but it does + + + align:start position:0% +stuff which is not the issue but it does +as you can + + align:start position:0% +as you can + + + align:start position:0% +as you can +see our site which is over there for the + + align:start position:0% +see our site which is over there for the + + + align:start position:0% +see our site which is over there for the +community is quite a bit lower than + + align:start position:0% +community is quite a bit lower than + + + align:start position:0% +community is quite a bit lower than +where we are not quite a bit but lower + + align:start position:0% +where we are not quite a bit but lower + + + align:start position:0% +where we are not quite a bit but lower +than this and then lower still than over + + align:start position:0% +than this and then lower still than over + + + align:start position:0% +than this and then lower still than over +here it's going uphill + + align:start position:0% +here it's going uphill + + + align:start position:0% +here it's going uphill +slightly now this area is what we we' + + align:start position:0% +slightly now this area is what we we' + + + align:start position:0% +slightly now this area is what we we' +like to build the E scale out of + + align:start position:0% +like to build the E scale out of + + + align:start position:0% +like to build the E scale out of +cardboard which is the equivalent to our + + align:start position:0% +cardboard which is the equivalent to our + + + align:start position:0% +cardboard which is the equivalent to our +Quarry but instead of a place now we + + align:start position:0% +Quarry but instead of a place now we + + + align:start position:0% +Quarry but instead of a place now we +have sort of a path we're relating to + + align:start position:0% +have sort of a path we're relating to + + + align:start position:0% +have sort of a path we're relating to +each end of the street on the other hand + + align:start position:0% +each end of the street on the other hand + + + align:start position:0% +each end of the street on the other hand +I suggest that you probably when you're + + align:start position:0% +I suggest that you probably when you're + + + align:start position:0% +I suggest that you probably when you're +done building almost everybody can wave + + align:start position:0% +done building almost everybody can wave + + + align:start position:0% +done building almost everybody can wave +to somebody she can wave to + + align:start position:0% +to somebody she can wave to + + + align:start position:0% +to somebody she can wave to +Phillip uh and + + align:start position:0% +Phillip uh and + + + align:start position:0% +Phillip uh and +Stacy so there'll be little + + align:start position:0% +Stacy so there'll be little + + + align:start position:0% +Stacy so there'll be little +subcommunities + + align:start position:0% +subcommunities + + + align:start position:0% +subcommunities +if you're close together in a site + + align:start position:0% +if you're close together in a site + + + align:start position:0% +if you're close together in a site +you're welcome to explore + + align:start position:0% +you're welcome to explore + + + align:start position:0% +you're welcome to explore +connections this is like the Quarry and + + align:start position:0% +connections this is like the Quarry and + + + align:start position:0% +connections this is like the Quarry and +you now are + + align:start position:0% +you now are + + + align:start position:0% +you now are +detectives a good architect in my + + align:start position:0% +detectives a good architect in my + + + align:start position:0% +detectives a good architect in my +opinion starts with the site this is our + + align:start position:0% +opinion starts with the site this is our + + + align:start position:0% +opinion starts with the site this is our +site so you want to learn as much as you + + align:start position:0% +site so you want to learn as much as you + + + align:start position:0% +site so you want to learn as much as you +can about the site and there are + + align:start position:0% +can about the site and there are + + + align:start position:0% +can about the site and there are +different kinds of + + align:start position:0% +different kinds of + + + align:start position:0% +different kinds of +information obviously there's + + align:start position:0% +information obviously there's + + + align:start position:0% +information obviously there's +architectural + + align:start position:0% +architectural + + + align:start position:0% +architectural +form you probably can find any kind of + + align:start position:0% +form you probably can find any kind of + + + align:start position:0% +form you probably can find any kind of +form you want in this site in fact + + align:start position:0% +form you want in this site in fact + + + align:start position:0% +form you want in this site in fact +there's a little surprise around the + + align:start position:0% +there's a little surprise around the + + + align:start position:0% +there's a little surprise around the +corner if you haven't seen it of a + + align:start position:0% +corner if you haven't seen it of a + + + align:start position:0% +corner if you haven't seen it of a +little guy sticking did you see it on + + align:start position:0% +little guy sticking did you see it on + + + align:start position:0% +little guy sticking did you see it on +the corner sticking on the side a little + + align:start position:0% +the corner sticking on the side a little + + + align:start position:0% +the corner sticking on the side a little +bay window there's all kinds of bay + + align:start position:0% +bay window there's all kinds of bay + + + align:start position:0% +bay window there's all kinds of bay +windows up there so form and materials + + align:start position:0% +windows up there so form and materials + + + align:start position:0% +windows up there so form and materials +is one clue that we're looking for but + + align:start position:0% +is one clue that we're looking for but + + + align:start position:0% +is one clue that we're looking for but +equally important is people and what + + align:start position:0% +equally important is people and what + + + align:start position:0% +equally important is people and what +they're doing what's happening here I + + align:start position:0% +they're doing what's happening here I + + + align:start position:0% +they're doing what's happening here I +mean look at what's happening right + + align:start position:0% +mean look at what's happening right + + + align:start position:0% +mean look at what's happening right +around us there are tourists from Iowa + + align:start position:0% +around us there are tourists from Iowa + + + align:start position:0% +around us there are tourists from Iowa +and Ohio and all over the country + + align:start position:0% +and Ohio and all over the country + + + align:start position:0% +and Ohio and all over the country +walking around but there are also + + align:start position:0% +walking around but there are also + + + align:start position:0% +walking around but there are also +residents you can see you can almost + + align:start position:0% +residents you can see you can almost + + + align:start position:0% +residents you can see you can almost +tell the difference Who's Who uh on + + align:start position:0% +tell the difference Who's Who uh on + + + align:start position:0% +tell the difference Who's Who uh on +weekends you'll find uh kids playing in + + align:start position:0% +weekends you'll find uh kids playing in + + + align:start position:0% +weekends you'll find uh kids playing in +the street you go to the Paul rier Mall + + align:start position:0% +the street you go to the Paul rier Mall + + + align:start position:0% +the street you go to the Paul rier Mall +this afternoon and you'll find you may + + align:start position:0% +this afternoon and you'll find you may + + + align:start position:0% +this afternoon and you'll find you may +find kids and tourists going through so + + align:start position:0% +find kids and tourists going through so + + + align:start position:0% +find kids and tourists going through so +it's a mixture you're adding to that + + align:start position:0% +it's a mixture you're adding to that + + + align:start position:0% +it's a mixture you're adding to that +mix be good to know something about who + + align:start position:0% +mix be good to know something about who + + + align:start position:0% +mix be good to know something about who +your neighbors are even though we're + + align:start position:0% +your neighbors are even though we're + + + align:start position:0% +your neighbors are even though we're +building in this Canyon because the next + + align:start position:0% +building in this Canyon because the next + + + align:start position:0% +building in this Canyon because the next +problem of the community place is how to + + align:start position:0% +problem of the community place is how to + + + align:start position:0% +problem of the community place is how to +bring everybody together including + + align:start position:0% +bring everybody together including + + + align:start position:0% +bring everybody together including +yourself there are other Clues there's + + align:start position:0% +yourself there are other Clues there's + + + align:start position:0% +yourself there are other Clues there's +his historic Clues what's the history + + align:start position:0% +his historic Clues what's the history + + + align:start position:0% +his historic Clues what's the history +why is this place why is the Northend + + align:start position:0% +why is this place why is the Northend + + + align:start position:0% +why is this place why is the Northend +like the North End what makes it + + align:start position:0% +like the North End what makes it + + + align:start position:0% +like the North End what makes it +different than the Back Bay + + align:start position:0% +different than the Back Bay + + + align:start position:0% +different than the Back Bay +why uh why are the streets like + + align:start position:0% +why uh why are the streets like + + + align:start position:0% +why uh why are the streets like +this I know why but you that you should + + align:start position:0% +this I know why but you that you should + + + align:start position:0% +this I know why but you that you should +find out so there there's history um of + + align:start position:0% +find out so there there's history um of + + + align:start position:0% +find out so there there's history um of +the place those are + + align:start position:0% +the place those are + + + align:start position:0% +the place those are +Clues um there's real Clues Philip was + + align:start position:0% +Clues um there's real Clues Philip was + + + align:start position:0% +Clues um there's real Clues Philip was +probably going to bring back somebody's + + align:start position:0% +probably going to bring back somebody's + + + align:start position:0% +probably going to bring back somebody's +steps or something you know you don't + + align:start position:0% +steps or something you know you don't + + + align:start position:0% +steps or something you know you don't +have to bring something back why why + + align:start position:0% +have to bring something back why why + + + align:start position:0% +have to bring something back why why +don't you bring back + + align:start position:0% +don't you bring back + + + align:start position:0% +don't you bring back +is uh what I call a clue which is + + align:start position:0% +is uh what I call a clue which is + + + align:start position:0% +is uh what I call a clue which is +something in your head or something + + align:start position:0% +something in your head or something + + + align:start position:0% +something in your head or something +physically so once again when we're back + + align:start position:0% +physically so once again when we're back + + + align:start position:0% +physically so once again when we're back +in the studio we can visualize the site + + align:start position:0% +in the studio we can visualize the site + + + align:start position:0% +in the studio we can visualize the site +as well as your own backyard like the + + align:start position:0% +as well as your own backyard like the + + + align:start position:0% +as well as your own backyard like the +query it's the same thing except it's + + align:start position:0% +query it's the same thing except it's + + + align:start position:0% +query it's the same thing except it's +different so you + + align:start position:0% +different so you + + + align:start position:0% +different so you +start to think + + align:start position:0% +start to think + + + align:start position:0% +start to think +about how you're going to add something + + align:start position:0% +about how you're going to add something + + + align:start position:0% +about how you're going to add something +to the and I'm using this one as an + + align:start position:0% +to the and I'm using this one as an + + + align:start position:0% +to the and I'm using this one as an +example to the side of that building + + align:start position:0% +example to the side of that building + + + align:start position:0% +example to the side of that building +through some + + align:start position:0% +through some + + + align:start position:0% +through some +sketches it seems to me that this person + + align:start position:0% +sketches it seems to me that this person + + + align:start position:0% +sketches it seems to me that this person +has to do something + + align:start position:0% +has to do something + + + align:start position:0% +has to do something +vertically I mean the the the house is + + align:start position:0% +vertically I mean the the the house is + + + align:start position:0% +vertically I mean the the the house is +going to be on several levels I would + + align:start position:0% +going to be on several levels I would + + + align:start position:0% +going to be on several levels I would +think there's a limit to how far you can + + align:start position:0% +think there's a limit to how far you can + + + align:start position:0% +think there's a limit to how far you can +can leave her off whereas on top of this + + align:start position:0% +can leave her off whereas on top of this + + + align:start position:0% +can leave her off whereas on top of this +roof it could be horizontal Philip up + + align:start position:0% +roof it could be horizontal Philip up + + + align:start position:0% +roof it could be horizontal Philip up +there could be horizontal and vertical + + align:start position:0% +there could be horizontal and vertical + + + align:start position:0% +there could be horizontal and vertical +he's not the highest um and who has the + + align:start position:0% +he's not the highest um and who has the + + + align:start position:0% +he's not the highest um and who has the +one right next to our community space + + align:start position:0% +one right next to our community space + + + align:start position:0% +one right next to our community space +not the the later Tower but over there + + align:start position:0% + + + + align:start position:0% + +one Kelly oh that's right Kelly has that + + align:start position:0% +one Kelly oh that's right Kelly has that + + + align:start position:0% +one Kelly oh that's right Kelly has that +that one is important because she kind + + align:start position:0% +that one is important because she kind + + + align:start position:0% +that one is important because she kind +of overlooks the whole + + align:start position:0% +of overlooks the whole + + + align:start position:0% +of overlooks the whole +area she's going to be the person who's + + align:start position:0% +area she's going to be the person who's + + + align:start position:0% +area she's going to be the person who's +going to be kind of the gatekeeper of + + align:start position:0% +going to be kind of the gatekeeper of + + + align:start position:0% +going to be kind of the gatekeeper of +our community area + + align:start position:0% + + + + align:start position:0% + +later who has uh number 12 12 is an + + align:start position:0% +later who has uh number 12 12 is an + + + align:start position:0% +later who has uh number 12 12 is an +interesting one cuz you're on the roof + + align:start position:0% +interesting one cuz you're on the roof + + + align:start position:0% +interesting one cuz you're on the roof +and you're over the side and you're a + + align:start position:0% +and you're over the side and you're a + + + align:start position:0% +and you're over the side and you're a +little bit fit on the outer Li limits of + + align:start position:0% +little bit fit on the outer Li limits of + + + align:start position:0% +little bit fit on the outer Li limits of +the of our + + align:start position:0% +the of our + + + align:start position:0% +the of our +community almost everybody else forms + + align:start position:0% +community almost everybody else forms + + + align:start position:0% +community almost everybody else forms +some communities that one does twoo it + + align:start position:0% +some communities that one does twoo it + + + align:start position:0% +some communities that one does twoo it +connects with three who is three so + + align:start position:0% +connects with three who is three so + + + align:start position:0% +connects with three who is three so +there's there's a little connection + + align:start position:0% +there's there's a little connection + + + align:start position:0% +there's there's a little connection +between the two of you and who's 13 + + align:start position:0% +between the two of you and who's 13 + + + align:start position:0% +between the two of you and who's 13 +you're 13 so there's a community of 12 + + align:start position:0% +you're 13 so there's a community of 12 + + + align:start position:0% +you're 13 so there's a community of 12 +15 and three they're very + + align:start position:0% +15 and three they're very + + + align:start position:0% +15 and three they're very +close Okay what I'd like to have you do + + align:start position:0% +close Okay what I'd like to have you do + + + align:start position:0% +close Okay what I'd like to have you do +is have a good + + align:start position:0% +is have a good + + + align:start position:0% +is have a good +time talk to by the way I I'll show you + + align:start position:0% +time talk to by the way I I'll show you + + + align:start position:0% +time talk to by the way I I'll show you +but I I would like to ask you to just + + align:start position:0% +but I I would like to ask you to just + + + align:start position:0% +but I I would like to ask you to just +kind of nose around talk to + + align:start position:0% +kind of nose around talk to + + + align:start position:0% +kind of nose around talk to +people um look and see and see what you + + align:start position:0% +people um look and see and see what you + + + align:start position:0% +people um look and see and see what you +can bring back see what how many + + align:start position:0% +can bring back see what how many + + + align:start position:0% +can bring back see what how many +different things you can find that might + + align:start position:0% +different things you can find that might + + + align:start position:0% +different things you can find that might +influence what you're designing that's + + align:start position:0% +influence what you're designing that's + + + align:start position:0% +influence what you're designing that's +one the second is to go to Paul re + + align:start position:0% +one the second is to go to Paul re + + + align:start position:0% +one the second is to go to Paul re +River's Mall which is the next street + + align:start position:0% +River's Mall which is the next street + + + align:start position:0% +River's Mall which is the next street +over which is um Handover and go up hand + + align:start position:0% +over which is um Handover and go up hand + + + align:start position:0% +over which is um Handover and go up hand +Handover about two or three blocks and + + align:start position:0% +Handover about two or three blocks and + + + align:start position:0% +Handover about two or three blocks and +it's on your left by the fire + + align:start position:0% +it's on your left by the fire + + + align:start position:0% +it's on your left by the fire +um station go through Paul Rivers's mall + + align:start position:0% +um station go through Paul Rivers's mall + + + align:start position:0% +um station go through Paul Rivers's mall +to the North Church that's where the + + align:start position:0% +to the North Church that's where the + + + align:start position:0% +to the North Church that's where the +lanterns + + align:start position:0% +lanterns + + + align:start position:0% +lanterns +were on the other side to the right you + + align:start position:0% +were on the other side to the right you + + + align:start position:0% +were on the other side to the right you +got to go all the way up to Paul Rivers + + align:start position:0% +got to go all the way up to Paul Rivers + + + align:start position:0% +got to go all the way up to Paul Rivers +uh sorry the north church and then come + + align:start position:0% +uh sorry the north church and then come + + + align:start position:0% +uh sorry the north church and then come +back along the other side you'll find a + + align:start position:0% +back along the other side you'll find a + + + align:start position:0% +back along the other side you'll find a +little quiet Courtyard and find that + + align:start position:0% +little quiet Courtyard and find that + + + align:start position:0% +little quiet Courtyard and find that +building that I spoke about that is + + align:start position:0% +building that I spoke about that is + + + align:start position:0% +building that I spoke about that is +hanging off the side so that's two + + align:start position:0% +hanging off the side so that's two + + + align:start position:0% +hanging off the side so that's two +things but walk around enjoy your + + align:start position:0% +things but walk around enjoy your + + + align:start position:0% +things but walk around enjoy your +and have a canoli or + + align:start position:0% + + + + align:start position:0% + +coffee \ No newline at end of file diff --git a/apWRSZbJCyM.txt b/apWRSZbJCyM.txt new file mode 100644 index 0000000000000000000000000000000000000000..f2ec7d12d06533a4941e0cbf53ddf74b2679ce38 --- /dev/null +++ b/apWRSZbJCyM.txt @@ -0,0 +1,6243 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT OpenCourseWare continue to + + align:start position:0% +will help MIT OpenCourseWare continue to + + + align:start position:0% +will help MIT OpenCourseWare continue to +offer high quality educational resources + + align:start position:0% +offer high quality educational resources + + + align:start position:0% +offer high quality educational resources +for free + + align:start position:0% +for free + + + align:start position:0% +for free +to make a donation or to view additional + + align:start position:0% +to make a donation or to view additional + + + align:start position:0% +to make a donation or to view additional +materials from hundreds of MIT courses + + align:start position:0% +materials from hundreds of MIT courses + + + align:start position:0% +materials from hundreds of MIT courses +visit MIT opencourseware at ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +I think it brings together I think some + + align:start position:0% +I think it brings together I think some + + + align:start position:0% +I think it brings together I think some +of the administrators but also in fact + + align:start position:0% +of the administrators but also in fact + + + align:start position:0% +of the administrators but also in fact +the last word of the text or liberation + + align:start position:0% +the last word of the text or liberation + + + align:start position:0% +the last word of the text or liberation +my point of the week and the future so + + align:start position:0% +my point of the week and the future so + + + align:start position:0% +my point of the week and the future so +this is our presentation on language + + align:start position:0% +this is our presentation on language + + + align:start position:0% +this is our presentation on language +resistance in the liberation welcome to + + align:start position:0% +resistance in the liberation welcome to + + + align:start position:0% +resistance in the liberation welcome to +the last day of class congratulations so + + align:start position:0% +the last day of class congratulations so + + + align:start position:0% +the last day of class congratulations so +as a roadmap we're going to go through + + align:start position:0% +as a roadmap we're going to go through + + + align:start position:0% +as a roadmap we're going to go through +first rethinking literacy the dialogue + + align:start position:0% +first rethinking literacy the dialogue + + + align:start position:0% +first rethinking literacy the dialogue +the piece by ferry and Mikado get up + + align:start position:0% +the piece by ferry and Mikado get up + + + align:start position:0% +the piece by ferry and Mikado get up +Macedo and then we're going to look at + + align:start position:0% +Macedo and then we're going to look at + + + align:start position:0% +Macedo and then we're going to look at +the literacy in critical pedagogy piece + + align:start position:0% +the literacy in critical pedagogy piece + + + align:start position:0% +the literacy in critical pedagogy piece +and then end with the MIT hati hati + + align:start position:0% +and then end with the MIT hati hati + + + align:start position:0% +and then end with the MIT hati hati +initiatives okay so this is just a + + align:start position:0% +initiatives okay so this is just a + + + align:start position:0% +initiatives okay so this is just a +little bit of a background on the + + align:start position:0% +little bit of a background on the + + + align:start position:0% +little bit of a background on the +writers of the first two pieces both of + + align:start position:0% +writers of the first two pieces both of + + + align:start position:0% +writers of the first two pieces both of +them are educators and critical pedagogy + + align:start position:0% +them are educators and critical pedagogy + + + align:start position:0% +them are educators and critical pedagogy +and ones from Brazil and one is caper + + align:start position:0% +and ones from Brazil and one is caper + + + align:start position:0% +and ones from Brazil and one is caper +day an American so in the first piece + + align:start position:0% +day an American so in the first piece + + + align:start position:0% +day an American so in the first piece +fairy mentions the permit the main + + align:start position:0% +fairy mentions the permit the main + + + align:start position:0% +fairy mentions the permit the main +premises of culture and I think that + + align:start position:0% +premises of culture and I think that + + + align:start position:0% +premises of culture and I think that +these are really important to keep in + + align:start position:0% +these are really important to keep in + + + align:start position:0% +these are really important to keep in +mind because this is a really + + align:start position:0% +mind because this is a really + + + align:start position:0% +mind because this is a really +interesting and I think powerful way to + + align:start position:0% +interesting and I think powerful way to + + + align:start position:0% +interesting and I think powerful way to +frame culture the first one is that + + align:start position:0% +frame culture the first one is that + + + align:start position:0% +frame culture the first one is that +cultural cultural processes are + + align:start position:0% +cultural cultural processes are + + + align:start position:0% +cultural cultural processes are +intimately connected with social + + align:start position:0% +intimately connected with social + + + align:start position:0% +intimately connected with social +relations especially with class + + align:start position:0% +relations especially with class + + + align:start position:0% +relations especially with class +relations and class formations with + + align:start position:0% +relations and class formations with + + + align:start position:0% +relations and class formations with +sexual divisions with racial structuring + + align:start position:0% +sexual divisions with racial structuring + + + align:start position:0% +sexual divisions with racial structuring +and social relations and with age + + align:start position:0% +and social relations and with age + + + align:start position:0% +and social relations and with age +oppressions as a form of dependency got + + align:start position:0% +oppressions as a form of dependency got + + + align:start position:0% +oppressions as a form of dependency got +it the second one culture involves power + + align:start position:0% +it the second one culture involves power + + + align:start position:0% +it the second one culture involves power +and helps to produce asymmetries and the + + align:start position:0% +and helps to produce asymmetries and the + + + align:start position:0% +and helps to produce asymmetries and the +abilities of individuals and social + + align:start position:0% +abilities of individuals and social + + + align:start position:0% +abilities of individuals and social +groups to define and realize their needs + + align:start position:0% +groups to define and realize their needs + + + align:start position:0% +groups to define and realize their needs +and third one culture is neither + + align:start position:0% +and third one culture is neither + + + align:start position:0% +and third one culture is neither +autonomous nor an externally determined + + align:start position:0% +autonomous nor an externally determined + + + align:start position:0% +autonomous nor an externally determined +field but obsess but a site of social + + align:start position:0% +field but obsess but a site of social + + + align:start position:0% +field but obsess but a site of social +difficulties and struggles + + align:start position:0% + + + + align:start position:0% + +those ideas are really important to keep + + align:start position:0% +those ideas are really important to keep + + + align:start position:0% +those ideas are really important to keep +in mind because this paper also raises + + align:start position:0% +in mind because this paper also raises + + + align:start position:0% +in mind because this paper also raises +this idea I know it is the social field + + align:start position:0% +this idea I know it is the social field + + + align:start position:0% +this idea I know it is the social field +which is kind of the combination of all + + align:start position:0% +which is kind of the combination of all + + + align:start position:0% +which is kind of the combination of all +of the beliefs myths aspirations hopes + + align:start position:0% +of the beliefs myths aspirations hopes + + + align:start position:0% +of the beliefs myths aspirations hopes +of a book of a society of a culture and + + align:start position:0% +of a book of a society of a culture and + + + align:start position:0% +of a book of a society of a culture and +so it's it includes things such as why + + align:start position:0% +so it's it includes things such as why + + + align:start position:0% +so it's it includes things such as why +racial hierarchies exist + + align:start position:0% +racial hierarchies exist + + + align:start position:0% +racial hierarchies exist +- why sexual divisions exist in like + + align:start position:0% +- why sexual divisions exist in like + + + align:start position:0% +- why sexual divisions exist in like +what roles gender gender people play in + + align:start position:0% +what roles gender gender people play in + + + align:start position:0% +what roles gender gender people play in +a society and it's really important to + + align:start position:0% +a society and it's really important to + + + align:start position:0% +a society and it's really important to +keep that in mind because if you're able + + align:start position:0% +keep that in mind because if you're able + + + align:start position:0% +keep that in mind because if you're able +to keep that in mind then you're able to + + align:start position:0% +to keep that in mind then you're able to + + + align:start position:0% +to keep that in mind then you're able to +think critically about that and through + + align:start position:0% +think critically about that and through + + + align:start position:0% +think critically about that and through +the critical process of engaging whether + + align:start position:0% +the critical process of engaging whether + + + align:start position:0% +the critical process of engaging whether +you're able to change the social field + + align:start position:0% +you're able to change the social field + + + align:start position:0% +you're able to change the social field +and so I think that that's important + + align:start position:0% +and so I think that that's important + + + align:start position:0% +and so I think that that's important +because even though this paper raises a + + align:start position:0% +because even though this paper raises a + + + align:start position:0% +because even though this paper raises a +lot of really powerful ideas it's still + + align:start position:0% +lot of really powerful ideas it's still + + + align:start position:0% +lot of really powerful ideas it's still +not perfect so one of the quotes of this + + align:start position:0% +not perfect so one of the quotes of this + + + align:start position:0% +not perfect so one of the quotes of this +paper is literacies oral dimension is + + align:start position:0% +paper is literacies oral dimension is + + + align:start position:0% +paper is literacies oral dimension is +important even if it takes place in a + + align:start position:0% +important even if it takes place in a + + + align:start position:0% +important even if it takes place in a +culture like that of the United States + + align:start position:0% +culture like that of the United States + + + align:start position:0% +culture like that of the United States +whose memory is predominately written + + align:start position:0% +whose memory is predominately written + + + align:start position:0% +whose memory is predominately written +not oral like that of Africa Africa is + + align:start position:0% +not oral like that of Africa Africa is + + + align:start position:0% +not oral like that of Africa Africa is +notic and so something like that is also + + align:start position:0% +notic and so something like that is also + + + align:start position:0% +notic and so something like that is also +part of the social field and would make + + align:start position:0% +part of the social field and would make + + + align:start position:0% +part of the social field and would make +it into this paper because even though + + align:start position:0% +it into this paper because even though + + + align:start position:0% +it into this paper because even though +ferry and Macedo are thinking critically + + align:start position:0% +ferry and Macedo are thinking critically + + + align:start position:0% +ferry and Macedo are thinking critically +about this they are not engaging with a + + align:start position:0% +about this they are not engaging with a + + + align:start position:0% +about this they are not engaging with a +full reality of cultural objectivity and + + align:start position:0% +full reality of cultural objectivity and + + + align:start position:0% +full reality of cultural objectivity and +being subjects within that yeah the next + + align:start position:0% +being subjects within that yeah the next + + + align:start position:0% +being subjects within that yeah the next +article Oliveri talks about the use of + + align:start position:0% +article Oliveri talks about the use of + + + align:start position:0% +article Oliveri talks about the use of +and he first starts talking about how + + align:start position:0% +and he first starts talking about how + + + align:start position:0% +and he first starts talking about how +the current traditional methods of + + align:start position:0% +the current traditional methods of + + + align:start position:0% +the current traditional methods of +literacy how they tend to ignore the + + align:start position:0% +literacy how they tend to ignore the + + + align:start position:0% +literacy how they tend to ignore the +importance of language in a person's + + align:start position:0% +importance of language in a person's + + + align:start position:0% +importance of language in a person's +education and he bases a lot of his + + align:start position:0% +education and he bases a lot of his + + + align:start position:0% +education and he bases a lot of his +theories on his experiences and from the + + align:start position:0% +theories on his experiences and from the + + + align:start position:0% +theories on his experiences and from the +second quote he says that the sad + + align:start position:0% +second quote he says that the sad + + + align:start position:0% +second quote he says that the sad +reality is that while education import + + align:start position:0% +reality is that while education import + + + align:start position:0% +reality is that while education import +provides access to positions of + + align:start position:0% +provides access to positions of + + + align:start position:0% +provides access to positions of +political and economic power for the + + align:start position:0% +political and economic power for the + + + align:start position:0% +political and economic power for the +high echelon of African society it + + align:start position:0% +high echelon of African society it + + + align:start position:0% +high echelon of African society it +screens out the majority of the masses + + align:start position:0% +screens out the majority of the masses + + + align:start position:0% +screens out the majority of the masses +who failed to learn Portuguese well + + align:start position:0% +who failed to learn Portuguese well + + + align:start position:0% +who failed to learn Portuguese well +enough to acquire the necessary literacy + + align:start position:0% +enough to acquire the necessary literacy + + + align:start position:0% +enough to acquire the necessary literacy +skills for social economic and political + + align:start position:0% +skills for social economic and political + + + align:start position:0% +skills for social economic and political +investment and you could definitely from + + align:start position:0% +investment and you could definitely from + + + align:start position:0% +investment and you could definitely from +the way that he mentions this you could + + align:start position:0% +the way that he mentions this you could + + + align:start position:0% +the way that he mentions this you could +definitely see a lot of like parallelism + + align:start position:0% +definitely see a lot of like parallelism + + + align:start position:0% +definitely see a lot of like parallelism +between what's going on around the world + + align:start position:0% +between what's going on around the world + + + align:start position:0% +between what's going on around the world +and eternity like in the United States + + align:start position:0% +and eternity like in the United States + + + align:start position:0% +and eternity like in the United States +and you could you could definitely see + + align:start position:0% +and you could you could definitely see + + + align:start position:0% +and you could you could definitely see +that the the one percent usually have + + align:start position:0% +that the the one percent usually have + + + align:start position:0% +that the the one percent usually have +the most control over things and that + + align:start position:0% +the most control over things and that + + + align:start position:0% +the most control over things and that +they usually tend to drive policies for + + align:start position:0% +they usually tend to drive policies for + + + align:start position:0% +they usually tend to drive policies for +me but the fact is that when a person is + + align:start position:0% +me but the fact is that when a person is + + + align:start position:0% +me but the fact is that when a person is +taught and during native language + + align:start position:0% +taught and during native language + + + align:start position:0% +taught and during native language +detents you learn things better and + + align:start position:0% +detents you learn things better and + + + align:start position:0% +detents you learn things better and +comprehend things faster and you go to + + align:start position:0% +comprehend things faster and you go to + + + align:start position:0% +comprehend things faster and you go to +the next lake there's usually backlash + + align:start position:0% +the next lake there's usually backlash + + + align:start position:0% +the next lake there's usually backlash +when it comes to different languages + + align:start position:0% +when it comes to different languages + + + align:start position:0% +when it comes to different languages +taught in schools for example in the + + align:start position:0% +taught in schools for example in the + + + align:start position:0% +taught in schools for example in the +u.s. people say that students should + + align:start position:0% +u.s. people say that students should + + + align:start position:0% +u.s. people say that students should +learn how to speak standard American + + align:start position:0% +learn how to speak standard American + + + align:start position:0% +learn how to speak standard American +English but when it comes to providing + + align:start position:0% +English but when it comes to providing + + + align:start position:0% +English but when it comes to providing +these sort of opportunities to minority + + align:start position:0% +these sort of opportunities to minority + + + align:start position:0% +these sort of opportunities to minority +group so I guess for instance like + + align:start position:0% +group so I guess for instance like + + + align:start position:0% +group so I guess for instance like +students of color there's usually some + + align:start position:0% +students of color there's usually some + + + align:start position:0% +students of color there's usually some +regional tensions that develop that that + + align:start position:0% +regional tensions that develop that that + + + align:start position:0% +regional tensions that develop that that +made minority students feel inferior + + align:start position:0% +made minority students feel inferior + + + align:start position:0% +made minority students feel inferior +for example there was an article + + align:start position:0% +for example there was an article + + + align:start position:0% +for example there was an article +mentioned like recently in like March of + + align:start position:0% +mentioned like recently in like March of + + + align:start position:0% +mentioned like recently in like March of +2017 that talked about a robotics team + + align:start position:0% +2017 that talked about a robotics team + + + align:start position:0% +2017 that talked about a robotics team +diversity that recently had won the + + align:start position:0% +diversity that recently had won the + + + align:start position:0% +diversity that recently had won the +challenge and the fact that after they + + align:start position:0% +challenge and the fact that after they + + + align:start position:0% +challenge and the fact that after they +had won students but I guess people in + + align:start position:0% +had won students but I guess people in + + + align:start position:0% +had won students but I guess people in +the crowd started screaming at them and + + align:start position:0% +the crowd started screaming at them and + + + align:start position:0% +the crowd started screaming at them and +telling them to go back to Mexico and so + + align:start position:0% +telling them to go back to Mexico and so + + + align:start position:0% +telling them to go back to Mexico and so +this form of like demeaning commentary + + align:start position:0% +this form of like demeaning commentary + + + align:start position:0% +this form of like demeaning commentary +tends to drive the dropout rate so + + align:start position:0% +tends to drive the dropout rate so + + + align:start position:0% +tends to drive the dropout rate so +minority groups and all this tends to + + align:start position:0% +minority groups and all this tends to + + + align:start position:0% +minority groups and all this tends to +contribute to like the prison sorry the + + align:start position:0% +contribute to like the prison sorry the + + + align:start position:0% +contribute to like the prison sorry the +school to Prison Pipeline has + + align:start position:0% +school to Prison Pipeline has + + + align:start position:0% +school to Prison Pipeline has +seen the infographic it definitely gives + + align:start position:0% +seen the infographic it definitely gives + + + align:start position:0% +seen the infographic it definitely gives +a lot of percentages on that talked + + align:start position:0% +a lot of percentages on that talked + + + align:start position:0% +a lot of percentages on that talked +about this sort of issue in the bottom + + align:start position:0% +about this sort of issue in the bottom + + + align:start position:0% +about this sort of issue in the bottom +when he says that 16% of all males in + + align:start position:0% +when he says that 16% of all males in + + + align:start position:0% +when he says that 16% of all males in +state and federal prison they do not + + align:start position:0% +state and federal prison they do not + + + align:start position:0% +state and federal prison they do not +have a high school diploma and this + + align:start position:0% +have a high school diploma and this + + + align:start position:0% +have a high school diploma and this +sense to me gives the statistics on + + align:start position:0% +sense to me gives the statistics on + + + align:start position:0% +sense to me gives the statistics on +students cooking and all of this 10th + + align:start position:0% +students cooking and all of this 10th + + + align:start position:0% +students cooking and all of this 10th +that tends to stem from the fact that + + align:start position:0% +that tends to stem from the fact that + + + align:start position:0% +that tends to stem from the fact that +minority students do not have the same + + align:start position:0% +minority students do not have the same + + + align:start position:0% +minority students do not have the same +access to education as you think our + + align:start position:0% +access to education as you think our + + + align:start position:0% +access to education as you think our +society and from personal experience I + + align:start position:0% +society and from personal experience I + + + align:start position:0% +society and from personal experience I +can definitely relate to this I went to + + align:start position:0% +can definitely relate to this I went to + + + align:start position:0% +can definitely relate to this I went to +school about like an hour and a half for + + align:start position:0% +school about like an hour and a half for + + + align:start position:0% +school about like an hour and a half for +my house and I definitely did have a lot + + align:start position:0% +my house and I definitely did have a lot + + + align:start position:0% +my house and I definitely did have a lot +of like good role models growing up but + + align:start position:0% +of like good role models growing up but + + + align:start position:0% +of like good role models growing up but +there were definitely and students + + align:start position:0% +there were definitely and students + + + align:start position:0% +there were definitely and students +around my neighborhood that didn't that + + align:start position:0% +around my neighborhood that didn't that + + + align:start position:0% +around my neighborhood that didn't that +definitely didn't have the same access + + align:start position:0% +definitely didn't have the same access + + + align:start position:0% +definitely didn't have the same access +to the same opportunities that I did + + align:start position:0% +to the same opportunities that I did + + + align:start position:0% +to the same opportunities that I did +some of them did drop out to serving + + align:start position:0% +some of them did drop out to serving + + + align:start position:0% +some of them did drop out to serving +others worried big gangs around my + + align:start position:0% +others worried big gangs around my + + + align:start position:0% +others worried big gangs around my +neighborhood and you could definitely + + align:start position:0% +neighborhood and you could definitely + + + align:start position:0% +neighborhood and you could definitely +these are definitely getting better but + + align:start position:0% +these are definitely getting better but + + + align:start position:0% +these are definitely getting better but +things could definitely be improved from + + align:start position:0% +things could definitely be improved from + + + align:start position:0% +things could definitely be improved from +any medicine that emancipatory literacy + + align:start position:0% +any medicine that emancipatory literacy + + + align:start position:0% +any medicine that emancipatory literacy +approach which is what Paula Ferry + + align:start position:0% +approach which is what Paula Ferry + + + align:start position:0% +approach which is what Paula Ferry +mentions yeah so in a monetary literacy + + align:start position:0% +mentions yeah so in a monetary literacy + + + align:start position:0% +mentions yeah so in a monetary literacy +this involves using the language of the + + align:start position:0% +this involves using the language of the + + + align:start position:0% +this involves using the language of the +people rather than the need to teach + + align:start position:0% +people rather than the need to teach + + + align:start position:0% +people rather than the need to teach +students to accept their experiences and + + align:start position:0% +students to accept their experiences and + + + align:start position:0% +students to accept their experiences and +their culture and this moves from the + + align:start position:0% +their culture and this moves from the + + + align:start position:0% +their culture and this moves from the +world of objectivity to the world of + + align:start position:0% +world of objectivity to the world of + + + align:start position:0% +world of objectivity to the world of +subjectivity where individuals learn to + + align:start position:0% +subjectivity where individuals learn to + + + align:start position:0% +subjectivity where individuals learn to +accept themselves for who they are + + align:start position:0% +accept themselves for who they are + + + align:start position:0% +accept themselves for who they are +rather than feel like they're a victim + + align:start position:0% +rather than feel like they're a victim + + + align:start position:0% +rather than feel like they're a victim +of society and pollen fury does mention + + align:start position:0% +of society and pollen fury does mention + + + align:start position:0% +of society and pollen fury does mention +that achieving emancipatory illiteracy + + align:start position:0% +that achieving emancipatory illiteracy + + + align:start position:0% +that achieving emancipatory illiteracy +is hard but it's not impossible and now + + align:start position:0% +is hard but it's not impossible and now + + + align:start position:0% +is hard but it's not impossible and now +and so learning was talked about a few + + align:start position:0% +and so learning was talked about a few + + + align:start position:0% +and so learning was talked about a few +examples of how this is being used today + + align:start position:0% +examples of how this is being used today + + + align:start position:0% +examples of how this is being used today +so considering specifically in the case + + align:start position:0% +so considering specifically in the case + + + align:start position:0% +so considering specifically in the case +of Haiti which Michelle works a lot on + + align:start position:0% +of Haiti which Michelle works a lot on + + + align:start position:0% +of Haiti which Michelle works a lot on +but that mighty Haiti initiative + + align:start position:0% +but that mighty Haiti initiative + + + align:start position:0% +but that mighty Haiti initiative +virtually all of the schooling in both K + + align:start position:0% +virtually all of the schooling in both K + + + align:start position:0% +virtually all of the schooling in both K +through 12 education and then + + align:start position:0% +through 12 education and then + + + align:start position:0% +through 12 education and then +higher education is done in French and + + align:start position:0% +higher education is done in French and + + + align:start position:0% +higher education is done in French and +not in Creole but the problem is that + + align:start position:0% +not in Creole but the problem is that + + + align:start position:0% +not in Creole but the problem is that +most people only speak Creole fluently + + align:start position:0% +most people only speak Creole fluently + + + align:start position:0% +most people only speak Creole fluently +so like 95 percent or so and very few + + align:start position:0% +so like 95 percent or so and very few + + + align:start position:0% +so like 95 percent or so and very few +people speak French fluently at all so + + align:start position:0% +people speak French fluently at all so + + + align:start position:0% +people speak French fluently at all so +when you go through school and + + align:start position:0% +when you go through school and + + + align:start position:0% +when you go through school and +everything is in a language that you + + align:start position:0% +everything is in a language that you + + + align:start position:0% +everything is in a language that you +don't understand how are you supposed to + + align:start position:0% +don't understand how are you supposed to + + + align:start position:0% +don't understand how are you supposed to +be able to actually get any of the + + align:start position:0% +be able to actually get any of the + + + align:start position:0% +be able to actually get any of the +education get any of the social + + align:start position:0% +education get any of the social + + + align:start position:0% +education get any of the social +engagement especially if children are + + align:start position:0% +engagement especially if children are + + + align:start position:0% +engagement especially if children are +punished for speaking Creole in school + + align:start position:0% +punished for speaking Creole in school + + + align:start position:0% +punished for speaking Creole in school +and they like can't interact with each + + align:start position:0% +and they like can't interact with each + + + align:start position:0% +and they like can't interact with each +other it can't ask questions can't + + align:start position:0% +other it can't ask questions can't + + + align:start position:0% +other it can't ask questions can't +gather any of the information that's + + align:start position:0% +gather any of the information that's + + + align:start position:0% +gather any of the information that's +coming at them so it's based on this + + align:start position:0% +coming at them so it's based on this + + + align:start position:0% +coming at them so it's based on this +false belief and really outdated belief + + align:start position:0% +false belief and really outdated belief + + + align:start position:0% +false belief and really outdated belief +about the hierarchy of languages about + + align:start position:0% +about the hierarchy of languages about + + + align:start position:0% +about the hierarchy of languages about +which languages are created or are + + align:start position:0% +which languages are created or are + + + align:start position:0% +which languages are created or are +younger or anything like that and that + + align:start position:0% +younger or anything like that and that + + + align:start position:0% +younger or anything like that and that +Creole isn't developed enough to be able + + align:start position:0% +Creole isn't developed enough to be able + + + align:start position:0% +Creole isn't developed enough to be able +to to be used for technical language for + + align:start position:0% +to to be used for technical language for + + + align:start position:0% +to to be used for technical language for +STEM education to have anything + + align:start position:0% +STEM education to have anything + + + align:start position:0% +STEM education to have anything +translated into Creole and part of that + + align:start position:0% +translated into Creole and part of that + + + align:start position:0% +translated into Creole and part of that +is saying that like Creole isn't + + align:start position:0% +is saying that like Creole isn't + + + align:start position:0% +is saying that like Creole isn't +widespread enough even though Creole has + + align:start position:0% +widespread enough even though Creole has + + + align:start position:0% +widespread enough even though Creole has +almost 10 million speakers finnish has + + align:start position:0% +almost 10 million speakers finnish has + + + align:start position:0% +almost 10 million speakers finnish has +only about 5.5 million speakers and yet + + align:start position:0% +only about 5.5 million speakers and yet + + + align:start position:0% +only about 5.5 million speakers and yet +in finland all of the education is done + + align:start position:0% +in finland all of the education is done + + + align:start position:0% +in finland all of the education is done +in finnish and people have studies have + + align:start position:0% +in finnish and people have studies have + + + align:start position:0% +in finnish and people have studies have +found that in finland kids are much + + align:start position:0% +found that in finland kids are much + + + align:start position:0% +found that in finland kids are much +better much better equipped to be able + + align:start position:0% +better much better equipped to be able + + + align:start position:0% +better much better equipped to be able +to learn a second language and to go + + align:start position:0% +to learn a second language and to go + + + align:start position:0% +to learn a second language and to go +into higher education and gather gather + + align:start position:0% +into higher education and gather gather + + + align:start position:0% +into higher education and gather gather +all of these like technical studies + + align:start position:0% +all of these like technical studies + + + align:start position:0% +all of these like technical studies +because all of their education is done + + align:start position:0% +because all of their education is done + + + align:start position:0% +because all of their education is done +in finnish and over i AP i was doing + + align:start position:0% +in finnish and over i AP i was doing + + + align:start position:0% +in finnish and over i AP i was doing +misty GTL in the Catalunya region in + + align:start position:0% +misty GTL in the Catalunya region in + + + align:start position:0% +misty GTL in the Catalunya region in +Spain and there + + align:start position:0% +Spain and there + + + align:start position:0% +Spain and there +Catalan also has a little under ten + + align:start position:0% +Catalan also has a little under ten + + + align:start position:0% +Catalan also has a little under ten +million speakers but in Catalunya all of + + align:start position:0% +million speakers but in Catalunya all of + + + align:start position:0% +million speakers but in Catalunya all of +the education is in Catalan which made + + align:start position:0% +the education is in Catalan which made + + + align:start position:0% +the education is in Catalan which made +it difficult for me as like a Spanish + + align:start position:0% +it difficult for me as like a Spanish + + + align:start position:0% +it difficult for me as like a Spanish +speaker like not even fluent but trying + + align:start position:0% +speaker like not even fluent but trying + + + align:start position:0% +speaker like not even fluent but trying +to speak Spanish speaker to be able to + + align:start position:0% +to speak Spanish speaker to be able to + + + align:start position:0% +to speak Spanish speaker to be able to +teach the students but they had such a + + align:start position:0% +teach the students but they had such a + + + align:start position:0% +teach the students but they had such a +better experience with all of their + + align:start position:0% +better experience with all of their + + + align:start position:0% +better experience with all of their +textbooks in Catalan all of their + + align:start position:0% +textbooks in Catalan all of their + + + align:start position:0% +textbooks in Catalan all of their +computer software so I was trying to + + align:start position:0% +computer software so I was trying to + + + align:start position:0% +computer software so I was trying to +teach them Inkscape and but + + align:start position:0% +teach them Inkscape and but + + + align:start position:0% +teach them Inkscape and but +everything was in Catalan and I just + + align:start position:0% +everything was in Catalan and I just + + + align:start position:0% +everything was in Catalan and I just +couldn't understand like even how to + + align:start position:0% +couldn't understand like even how to + + + align:start position:0% +couldn't understand like even how to +open a window um so they taught me a lot + + align:start position:0% +open a window um so they taught me a lot + + + align:start position:0% +open a window um so they taught me a lot +about this + + align:start position:0% +about this + + + align:start position:0% +about this +they all of them speak Catalan and + + align:start position:0% +they all of them speak Catalan and + + + align:start position:0% +they all of them speak Catalan and +Spanish and English and then they can + + align:start position:0% +Spanish and English and then they can + + + align:start position:0% +Spanish and English and then they can +like learn German or French on the side + + align:start position:0% +like learn German or French on the side + + + align:start position:0% +like learn German or French on the side +as well so all of them because their + + align:start position:0% +as well so all of them because their + + + align:start position:0% +as well so all of them because their +initial education K through 12 and then + + align:start position:0% +initial education K through 12 and then + + + align:start position:0% +initial education K through 12 and then +higher education if they want it to be + + align:start position:0% +higher education if they want it to be + + + align:start position:0% +higher education if they want it to be +is in Catalan then they can learn all of + + align:start position:0% +is in Catalan then they can learn all of + + + align:start position:0% +is in Catalan then they can learn all of +these other things just as well as we do + + align:start position:0% +these other things just as well as we do + + + align:start position:0% +these other things just as well as we do +like in English with it which is mostly + + align:start position:0% +like in English with it which is mostly + + + align:start position:0% +like in English with it which is mostly +our one and kind of only language in the + + align:start position:0% +our one and kind of only language in the + + + align:start position:0% +our one and kind of only language in the +United States yeah so that was my + + align:start position:0% +United States yeah so that was my + + + align:start position:0% +United States yeah so that was my +experience and what a school that is + + align:start position:0% +experience and what a school that is + + + align:start position:0% +experience and what a school that is +like a really good model in Haiti is the + + align:start position:0% +like a really good model in Haiti is the + + + align:start position:0% +like a really good model in Haiti is the +lkm school I didn't know how to + + align:start position:0% +lkm school I didn't know how to + + + align:start position:0% +lkm school I didn't know how to +pronounce it in Creole so South cam it's + + align:start position:0% +pronounce it in Creole so South cam it's + + + align:start position:0% +pronounce it in Creole so South cam it's +a k310 school in a rural part on an + + align:start position:0% +a k310 school in a rural part on an + + + align:start position:0% +a k310 school in a rural part on an +island of Haiti and their education is + + align:start position:0% +island of Haiti and their education is + + + align:start position:0% +island of Haiti and their education is +starting to be in this model of all + + align:start position:0% +starting to be in this model of all + + + align:start position:0% +starting to be in this model of all +Creole education trying to teach all of + + align:start position:0% +Creole education trying to teach all of + + + align:start position:0% +Creole education trying to teach all of +these subjects all of the technical + + align:start position:0% +these subjects all of the technical + + + align:start position:0% +these subjects all of the technical +terms in Creole and the students are + + align:start position:0% +terms in Creole and the students are + + + align:start position:0% +terms in Creole and the students are +learning much better than the rest of + + align:start position:0% +learning much better than the rest of + + + align:start position:0% +learning much better than the rest of +the students in Haiti who's schooling is + + align:start position:0% +the students in Haiti who's schooling is + + + align:start position:0% +the students in Haiti who's schooling is +at French and who only 10% graduate from + + align:start position:0% +at French and who only 10% graduate from + + + align:start position:0% +at French and who only 10% graduate from +high school + + align:start position:0% +high school + + + align:start position:0% +high school +so the linguistic apartheid part of this + + align:start position:0% +so the linguistic apartheid part of this + + + align:start position:0% +so the linguistic apartheid part of this +is that when you teach somebody in a + + align:start position:0% +is that when you teach somebody in a + + + align:start position:0% +is that when you teach somebody in a +language they don't understand you + + align:start position:0% +language they don't understand you + + + align:start position:0% +language they don't understand you +prevent them from being able to move + + align:start position:0% +prevent them from being able to move + + + align:start position:0% +prevent them from being able to move +into different socio-economic classes to + + align:start position:0% +into different socio-economic classes to + + + align:start position:0% +into different socio-economic classes to +attain the education and the success + + align:start position:0% +attain the education and the success + + + align:start position:0% +attain the education and the success +that they should be able to and this all + + align:start position:0% +that they should be able to and this all + + + align:start position:0% +that they should be able to and this all +leads to a mighty Haiti initiative that + + align:start position:0% +leads to a mighty Haiti initiative that + + + align:start position:0% +leads to a mighty Haiti initiative that +we shall started here between MIT and + + align:start position:0% +we shall started here between MIT and + + + align:start position:0% +we shall started here between MIT and +all the Haitian education systems so a + + align:start position:0% +all the Haitian education systems so a + + + align:start position:0% +all the Haitian education systems so a +couple of their main points are to teach + + align:start position:0% +couple of their main points are to teach + + + align:start position:0% +couple of their main points are to teach +educators in Haiti that teaching and + + align:start position:0% +educators in Haiti that teaching and + + + align:start position:0% +educators in Haiti that teaching and +creole is perfectly fine that it is + + align:start position:0% +creole is perfectly fine that it is + + + align:start position:0% +creole is perfectly fine that it is +actually better for the students that it + + align:start position:0% +actually better for the students that it + + + align:start position:0% +actually better for the students that it +gives them more opportunities and that + + align:start position:0% +gives them more opportunities and that + + + align:start position:0% +gives them more opportunities and that +stem and technical subjects can be + + align:start position:0% +stem and technical subjects can be + + + align:start position:0% +stem and technical subjects can be +taught in Creole so a lot of the worries + + align:start position:0% +taught in Creole so a lot of the worries + + + align:start position:0% +taught in Creole so a lot of the worries +or concerns are that like Creole doesn't + + align:start position:0% +or concerns are that like Creole doesn't + + + align:start position:0% +or concerns are that like Creole doesn't +have words for these languages we didn't + + align:start position:0% +have words for these languages we didn't + + + align:start position:0% +have words for these languages we didn't +have words for a computer either up + + align:start position:0% +have words for a computer either up + + + align:start position:0% +have words for a computer either up +until when they were created a lot of + + align:start position:0% +until when they were created a lot of + + + align:start position:0% +until when they were created a lot of +other languages borrow words from other + + align:start position:0% +other languages borrow words from other + + + align:start position:0% +other languages borrow words from other +languages so I learned Japanese and in + + align:start position:0% +languages so I learned Japanese and in + + + align:start position:0% +languages so I learned Japanese and in +Japanese there's this lovely thing + + align:start position:0% +Japanese there's this lovely thing + + + align:start position:0% +Japanese there's this lovely thing +called katakana where you just grab + + align:start position:0% +called katakana where you just grab + + + align:start position:0% +called katakana where you just grab +where it's your mother language so if + + align:start position:0% +where it's your mother language so if + + + align:start position:0% +where it's your mother language so if +you don't know how to pronounce it you + + align:start position:0% +you don't know how to pronounce it you + + + align:start position:0% +you don't know how to pronounce it you +kind of like make it sound like it and + + align:start position:0% +kind of like make it sound like it and + + + align:start position:0% +kind of like make it sound like it and +oftentimes it + + align:start position:0% +oftentimes it + + + align:start position:0% +oftentimes it +is what has been borrowed so for example + + align:start position:0% +is what has been borrowed so for example + + + align:start position:0% +is what has been borrowed so for example +bread is pun from German and all of + + align:start position:0% +bread is pun from German and all of + + + align:start position:0% +bread is pun from German and all of +these other languages have words + + align:start position:0% +these other languages have words + + + align:start position:0% +these other languages have words +borrowed from other languages and that's + + align:start position:0% +borrowed from other languages and that's + + + align:start position:0% +borrowed from other languages and that's +what globalization does so the same + + align:start position:0% +what globalization does so the same + + + align:start position:0% +what globalization does so the same +thing should be able to happen with + + align:start position:0% +thing should be able to happen with + + + align:start position:0% +thing should be able to happen with +Creole and stem learning and the really + + align:start position:0% +Creole and stem learning and the really + + + align:start position:0% +Creole and stem learning and the really +good results of this or that they + + align:start position:0% +good results of this or that they + + + align:start position:0% +good results of this or that they +affirmed students cultures and + + align:start position:0% +affirmed students cultures and + + + align:start position:0% +affirmed students cultures and +backgrounds and their own upbringing and + + align:start position:0% +backgrounds and their own upbringing and + + + align:start position:0% +backgrounds and their own upbringing and +how the society actually works as + + align:start position:0% +how the society actually works as + + + align:start position:0% +how the society actually works as +opposed to a colonial oppressive society + + align:start position:0% +opposed to a colonial oppressive society + + + align:start position:0% +opposed to a colonial oppressive society +and equalize the students being able to + + align:start position:0% +and equalize the students being able to + + + align:start position:0% +and equalize the students being able to +have more social mobility and to attain + + align:start position:0% +have more social mobility and to attain + + + align:start position:0% +have more social mobility and to attain +what they want and what they should be + + align:start position:0% +what they want and what they should be + + + align:start position:0% +what they want and what they should be +able to so to kind of tie this back to + + align:start position:0% +able to so to kind of tie this back to + + + align:start position:0% +able to so to kind of tie this back to +what we can do to stay woke with regards + + align:start position:0% +what we can do to stay woke with regards + + + align:start position:0% +what we can do to stay woke with regards +to literacy I think it's important to + + align:start position:0% +to literacy I think it's important to + + + align:start position:0% +to literacy I think it's important to +remember that language is a mediating + + align:start position:0% +remember that language is a mediating + + + align:start position:0% +remember that language is a mediating +force of knowledge but it is also + + align:start position:0% +force of knowledge but it is also + + + align:start position:0% +force of knowledge but it is also +knowledge itself and so one approach is + + align:start position:0% +knowledge itself and so one approach is + + + align:start position:0% +knowledge itself and so one approach is +for groups to kind of come together and + + align:start position:0% +for groups to kind of come together and + + + align:start position:0% +for groups to kind of come together and +create a language that describes their + + align:start position:0% +create a language that describes their + + + align:start position:0% +create a language that describes their +experience amongst themselves and then + + align:start position:0% +experience amongst themselves and then + + + align:start position:0% +experience amongst themselves and then +to share that language and to share that + + align:start position:0% +to share that language and to share that + + + align:start position:0% +to share that language and to share that +experience in their own in their own + + align:start position:0% +experience in their own in their own + + + align:start position:0% +experience in their own in their own +language and I think that that is one + + align:start position:0% +language and I think that that is one + + + align:start position:0% +language and I think that that is one +way that we can start breaking away from + + align:start position:0% +way that we can start breaking away from + + + align:start position:0% +way that we can start breaking away from +the kind of putting standard English on + + align:start position:0% +the kind of putting standard English on + + + align:start position:0% +the kind of putting standard English on +a pedestal and can also kind of validate + + align:start position:0% +a pedestal and can also kind of validate + + + align:start position:0% +a pedestal and can also kind of validate +other discourses and other ways of being + + align:start position:0% +other discourses and other ways of being + + + align:start position:0% +other discourses and other ways of being +and other just languages that kind of + + align:start position:0% +and other just languages that kind of + + + align:start position:0% +and other just languages that kind of +already exists in the US and across the + + align:start position:0% +already exists in the US and across the + + + align:start position:0% +already exists in the US and across the +world + + align:start position:0% + + + + align:start position:0% + +questions okay how have our + + align:start position:0% +questions okay how have our + + + align:start position:0% +questions okay how have our +understandings of literacy evolved in + + align:start position:0% +understandings of literacy evolved in + + + align:start position:0% +understandings of literacy evolved in +response to the internet unprecedented + + align:start position:0% +response to the internet unprecedented + + + align:start position:0% +response to the internet unprecedented +global integration and increased + + align:start position:0% +global integration and increased + + + align:start position:0% +global integration and increased +pressure to preserve human rights for + + align:start position:0% +pressure to preserve human rights for + + + align:start position:0% +pressure to preserve human rights for +example what does it mean that schools + + align:start position:0% +example what does it mean that schools + + + align:start position:0% +example what does it mean that schools +repress the development of subjectivity + + align:start position:0% +repress the development of subjectivity + + + align:start position:0% +repress the development of subjectivity +but due largely ensure literacy + + align:start position:0% +but due largely ensure literacy + + + align:start position:0% +but due largely ensure literacy +how can modern notions of literacy + + align:start position:0% +how can modern notions of literacy + + + align:start position:0% +how can modern notions of literacy +evolved to address phenomena such as the + + align:start position:0% +evolved to address phenomena such as the + + + align:start position:0% +evolved to address phenomena such as the +prolific proliferation of fake news so + + align:start position:0% +prolific proliferation of fake news so + + + align:start position:0% +prolific proliferation of fake news so +if we're moving past literacy as just + + align:start position:0% +if we're moving past literacy as just + + + align:start position:0% +if we're moving past literacy as just +the idea of being able to read and we + + align:start position:0% +the idea of being able to read and we + + + align:start position:0% +the idea of being able to read and we +are entering this new kind of this new + + align:start position:0% +are entering this new kind of this new + + + align:start position:0% +are entering this new kind of this new +waving that's largely pushed by the + + align:start position:0% +waving that's largely pushed by the + + + align:start position:0% +waving that's largely pushed by the +Internet and the influence of Technology + + align:start position:0% +Internet and the influence of Technology + + + align:start position:0% +Internet and the influence of Technology +on the way we live literacy is coming to + + align:start position:0% +on the way we live literacy is coming to + + + align:start position:0% +on the way we live literacy is coming to +being a more critical approach to life + + align:start position:0% +being a more critical approach to life + + + align:start position:0% +being a more critical approach to life +in the sense that fake news is a thing + + align:start position:0% +in the sense that fake news is a thing + + + align:start position:0% +in the sense that fake news is a thing +you know and it's actually quite hard to + + align:start position:0% +you know and it's actually quite hard to + + + align:start position:0% +you know and it's actually quite hard to +distinguish what news is really what + + align:start position:0% +distinguish what news is really what + + + align:start position:0% +distinguish what news is really what +news is fake and the ability to do that + + align:start position:0% +news is fake and the ability to do that + + + align:start position:0% +news is fake and the ability to do that +having that critical lens is maybe the + + align:start position:0% +having that critical lens is maybe the + + + align:start position:0% +having that critical lens is maybe the +next evolution of literacy so any ideas + + align:start position:0% +next evolution of literacy so any ideas + + + align:start position:0% +next evolution of literacy so any ideas +that I guess is the question but + + align:start position:0% +that I guess is the question but + + + align:start position:0% +that I guess is the question but +something that I think is kind of + + align:start position:0% +something that I think is kind of + + + align:start position:0% +something that I think is kind of +hilarious about like integration the + + align:start position:0% +hilarious about like integration the + + + align:start position:0% +hilarious about like integration the +Internet is that I think it + + align:start position:0% +Internet is that I think it + + + align:start position:0% +Internet is that I think it +simultaneously making us more literate + + align:start position:0% +simultaneously making us more literate + + + align:start position:0% +simultaneously making us more literate +and less literate so like or like + + align:start position:0% +and less literate so like or like + + + align:start position:0% +and less literate so like or like +crushing me to be more literate so + + align:start position:0% +crushing me to be more literate so + + + align:start position:0% +crushing me to be more literate so +pressuring you to be more literate now + + align:start position:0% +pressuring you to be more literate now + + + align:start position:0% +pressuring you to be more literate now +there's a bunch of sources that you can + + align:start position:0% +there's a bunch of sources that you can + + + align:start position:0% +there's a bunch of sources that you can +read and like now you can be more + + align:start position:0% +read and like now you can be more + + + align:start position:0% +read and like now you can be more +educated it's all open to the public you + + align:start position:0% +educated it's all open to the public you + + + align:start position:0% +educated it's all open to the public you +have a computer and then there's also + + align:start position:0% +have a computer and then there's also + + + align:start position:0% +have a computer and then there's also +like the pressure to speak English + + align:start position:0% +like the pressure to speak English + + + align:start position:0% +like the pressure to speak English +properly based off either you know like + + align:start position:0% +properly based off either you know like + + + align:start position:0% +properly based off either you know like +this one viral videos old grandma's + + align:start position:0% +this one viral videos old grandma's + + + align:start position:0% +this one viral videos old grandma's +screaming at this + + align:start position:0% +screaming at this + + + align:start position:0% +screaming at this +I hop because she was paying in Spanish + + align:start position:0% +I hop because she was paying in Spanish + + + align:start position:0% +I hop because she was paying in Spanish +or something like that so like it puts + + align:start position:0% +or something like that so like it puts + + + align:start position:0% +or something like that so like it puts +pressure on you to speak English + + align:start position:0% +pressure on you to speak English + + + align:start position:0% +pressure on you to speak English +correctly and then meanwhile because of + + align:start position:0% +correctly and then meanwhile because of + + + align:start position:0% +correctly and then meanwhile because of +like things like Facebook and like any + + align:start position:0% +like things like Facebook and like any + + + align:start position:0% +like things like Facebook and like any +social media people like don't speak + + align:start position:0% +social media people like don't speak + + + align:start position:0% +social media people like don't speak +correctly like typing like you know + + align:start position:0% +correctly like typing like you know + + + align:start position:0% +correctly like typing like you know +abbreviations and stuff that's + + align:start position:0% +abbreviations and stuff that's + + + align:start position:0% +abbreviations and stuff that's +acceptable in tax but like meanwhile + + align:start position:0% +acceptable in tax but like meanwhile + + + align:start position:0% +acceptable in tax but like meanwhile +we're saying like you should speak + + align:start position:0% +we're saying like you should speak + + + align:start position:0% +we're saying like you should speak +English properly so it's kind of a weird + + align:start position:0% +English properly so it's kind of a weird + + + align:start position:0% +English properly so it's kind of a weird +dichotomy I'm interested in the age + + align:start position:0% +dichotomy I'm interested in the age + + + align:start position:0% +dichotomy I'm interested in the age +implications of what you just said kind + + align:start position:0% +implications of what you just said kind + + + align:start position:0% +implications of what you just said kind +of a lining kind of a critique towards + + align:start position:0% +of a lining kind of a critique towards + + + align:start position:0% +of a lining kind of a critique towards +the use of different varieties of + + align:start position:0% +the use of different varieties of + + + align:start position:0% +the use of different varieties of +English with older generations and the + + align:start position:0% +English with older generations and the + + + align:start position:0% +English with older generations and the +use of non-standard varieties of English + + align:start position:0% +use of non-standard varieties of English + + + align:start position:0% +use of non-standard varieties of English +with younger donations I'm interested in + + align:start position:0% +with younger donations I'm interested in + + + align:start position:0% +with younger donations I'm interested in +that yeah I think I mean I guess like so + + align:start position:0% +that yeah I think I mean I guess like so + + + align:start position:0% +that yeah I think I mean I guess like so +like there's a grandma that I know + + align:start position:0% +like there's a grandma that I know + + + align:start position:0% +like there's a grandma that I know +that's on Facebook and like she like + + align:start position:0% +that's on Facebook and like she like + + + align:start position:0% +that's on Facebook and like she like +make sure it's to like type everything + + align:start position:0% +make sure it's to like type everything + + + align:start position:0% +make sure it's to like type everything +out including punctuation like her + + align:start position:0% +out including punctuation like her + + + align:start position:0% +out including punctuation like her +facebook posts are longer and like + + align:start position:0% +facebook posts are longer and like + + + align:start position:0% +facebook posts are longer and like +they're more like here's a card I think + + align:start position:0% +they're more like here's a card I think + + + align:start position:0% +they're more like here's a card I think +today where is like my facebook a I'm + + align:start position:0% +today where is like my facebook a I'm + + + align:start position:0% +today where is like my facebook a I'm +just sharing things but B if I really + + align:start position:0% +just sharing things but B if I really + + + align:start position:0% +just sharing things but B if I really +think it's probably which so I think it + + align:start position:0% +think it's probably which so I think it + + + align:start position:0% +think it's probably which so I think it +does depend on like your age group but + + align:start position:0% +does depend on like your age group but + + + align:start position:0% +does depend on like your age group but +also like going back to the original + + align:start position:0% +also like going back to the original + + + align:start position:0% +also like going back to the original +point of like you know that grandma's + + align:start position:0% +point of like you know that grandma's + + + align:start position:0% +point of like you know that grandma's +screaming at the Hispanic woman and like + + align:start position:0% +screaming at the Hispanic woman and like + + + align:start position:0% +screaming at the Hispanic woman and like +an IHOP like it's not just like an older + + align:start position:0% +an IHOP like it's not just like an older + + + align:start position:0% +an IHOP like it's not just like an older +woman screaming because you know she's + + align:start position:0% +woman screaming because you know she's + + + align:start position:0% +woman screaming because you know she's +more illiterate like there's also like + + align:start position:0% +more illiterate like there's also like + + + align:start position:0% +more illiterate like there's also like +kids who like think like oh you have to + + align:start position:0% +kids who like think like oh you have to + + + align:start position:0% +kids who like think like oh you have to +speak English up here so like they're + + align:start position:0% +speak English up here so like they're + + + align:start position:0% +speak English up here so like they're +you still is that weirdness between like + + align:start position:0% +you still is that weirdness between like + + + align:start position:0% +you still is that weirdness between like +how like older people like act on + + align:start position:0% +how like older people like act on + + + align:start position:0% +how like older people like act on +facebook and stuff like that but I still + + align:start position:0% +facebook and stuff like that but I still + + + align:start position:0% +facebook and stuff like that but I still +think like the point of you know + + align:start position:0% +think like the point of you know + + + align:start position:0% +think like the point of you know +pressuring people is regardless of age + + align:start position:0% + + + + align:start position:0% + +I think because I'm going to be talking + + align:start position:0% +I think because I'm going to be talking + + + align:start position:0% +I think because I'm going to be talking +about language which is dialects in this + + align:start position:0% +about language which is dialects in this + + + align:start position:0% +about language which is dialects in this +class I would kind of risk saying that + + align:start position:0% +class I would kind of risk saying that + + + align:start position:0% +class I would kind of risk saying that +we're kind of creating a new language + + align:start position:0% +we're kind of creating a new language + + + align:start position:0% +we're kind of creating a new language +because of the internet with like all + + align:start position:0% +because of the internet with like all + + + align:start position:0% +because of the internet with like all +the abbreviations and things and the way + + align:start position:0% +the abbreviations and things and the way + + + align:start position:0% +the abbreviations and things and the way +push for speed and everything like that + + align:start position:0% +push for speed and everything like that + + + align:start position:0% +push for speed and everything like that +so I think the reason that old + + align:start position:0% +so I think the reason that old + + + align:start position:0% +so I think the reason that old +generations don't use it as question + + align:start position:0% +generations don't use it as question + + + align:start position:0% +generations don't use it as question +because it I used to it and then like + + align:start position:0% +because it I used to it and then like + + + align:start position:0% +because it I used to it and then like +that differently frame of reference and + + align:start position:0% +that differently frame of reference and + + + align:start position:0% +that differently frame of reference and +they just haven't like learned this new + + align:start position:0% +they just haven't like learned this new + + + align:start position:0% +they just haven't like learned this new +dialect that we're starting to use so I + + align:start position:0% +dialect that we're starting to use so I + + + align:start position:0% +dialect that we're starting to use so I +think that it's a good thing in a sense + + align:start position:0% +think that it's a good thing in a sense + + + align:start position:0% +think that it's a good thing in a sense +but a lot of people who want that + + align:start position:0% +but a lot of people who want that + + + align:start position:0% +but a lot of people who want that +standard American English are going to + + align:start position:0% +standard American English are going to + + + align:start position:0% +standard American English are going to +be pushing us to go back to that as + + align:start position:0% +be pushing us to go back to that as + + + align:start position:0% +be pushing us to go back to that as +opposed to using the Internet in English + + align:start position:0% +opposed to using the Internet in English + + + align:start position:0% +opposed to using the Internet in English +the goys parts like our Cajun taste in + + align:start position:0% +the goys parts like our Cajun taste in + + + align:start position:0% +the goys parts like our Cajun taste in +literacy because of the internet like I + + align:start position:0% +literacy because of the internet like I + + + align:start position:0% +literacy because of the internet like I +didn't know that the onion was satire at + + align:start position:0% +didn't know that the onion was satire at + + + align:start position:0% +didn't know that the onion was satire at +first I said look at the end it existed + + align:start position:0% +first I said look at the end it existed + + + align:start position:0% +first I said look at the end it existed +and then I found I realized that it was + + align:start position:0% +and then I found I realized that it was + + + align:start position:0% +and then I found I realized that it was +satire I think step new ones like that + + align:start position:0% +satire I think step new ones like that + + + align:start position:0% +satire I think step new ones like that +is something that you miss especially + + align:start position:0% +is something that you miss especially + + + align:start position:0% +is something that you miss especially +with the internet because you can't + + align:start position:0% +with the internet because you can't + + + align:start position:0% +with the internet because you can't +really express sarcasm very clearly over + + align:start position:0% +really express sarcasm very clearly over + + + align:start position:0% +really express sarcasm very clearly over +just plain text I think that's something + + align:start position:0% +just plain text I think that's something + + + align:start position:0% +just plain text I think that's something +that we're + + align:start position:0% + + + + align:start position:0% + +but I think that he said we talked about + + align:start position:0% +but I think that he said we talked about + + + align:start position:0% +but I think that he said we talked about +the onion I think that shows like that + + align:start position:0% +the onion I think that shows like that + + + align:start position:0% +the onion I think that shows like that +show that + + align:start position:0% + + + + align:start position:0% + +I want to bounce up what you rich and he + + align:start position:0% +I want to bounce up what you rich and he + + + align:start position:0% +I want to bounce up what you rich and he +said like with like it's not a bad thing + + align:start position:0% +said like with like it's not a bad thing + + + align:start position:0% +said like with like it's not a bad thing +that we're tending my language I cream + + align:start position:0% +that we're tending my language I cream + + + align:start position:0% +that we're tending my language I cream +it like dimension do you think like + + align:start position:0% +it like dimension do you think like + + + align:start position:0% +it like dimension do you think like +there are certain rules like the way we + + align:start position:0% +there are certain rules like the way we + + + align:start position:0% +there are certain rules like the way we +type and laid there like illiterate like + + align:start position:0% + + + + align:start position:0% + +like for instance punctuating substances + + align:start position:0% +like for instance punctuating substances + + + align:start position:0% +like for instance punctuating substances +with like lol oh haha + + align:start position:0% +with like lol oh haha + + + align:start position:0% +with like lol oh haha +I didn't realize my question is so + + align:start position:0% +I didn't realize my question is so + + + align:start position:0% +I didn't realize my question is so +knowing now that people grow up in a + + align:start position:0% +knowing now that people grow up in a + + + align:start position:0% +knowing now that people grow up in a +type of leaders into whether it's a + + align:start position:0% +type of leaders into whether it's a + + + align:start position:0% +type of leaders into whether it's a +tradition or emancipatory what are the + + align:start position:0% +tradition or emancipatory what are the + + + align:start position:0% +tradition or emancipatory what are the +pros and cons of your type of literacy + + align:start position:0% +pros and cons of your type of literacy + + + align:start position:0% +pros and cons of your type of literacy +and explain the moon why we should move + + align:start position:0% +and explain the moon why we should move + + + align:start position:0% +and explain the moon why we should move +either towards or away from it from an + + align:start position:0% +either towards or away from it from an + + + align:start position:0% +either towards or away from it from an +emancipatory leaders + + align:start position:0% + + + + align:start position:0% + +I mean if it's helping people learn I + + align:start position:0% +I mean if it's helping people learn I + + + align:start position:0% +I mean if it's helping people learn I +don't see Adama + + align:start position:0% +don't see Adama + + + align:start position:0% +don't see Adama +especially because it's kind of + + align:start position:0% +especially because it's kind of + + + align:start position:0% +especially because it's kind of +broadening their worldview a a couple of + + align:start position:0% +broadening their worldview a a couple of + + + align:start position:0% +broadening their worldview a a couple of +presentations ago there were the + + align:start position:0% +presentations ago there were the + + + align:start position:0% +presentations ago there were the +students who are playing jeopardy with + + align:start position:0% +students who are playing jeopardy with + + + align:start position:0% +students who are playing jeopardy with +AE and that was kind of like broadening + + align:start position:0% +AE and that was kind of like broadening + + + align:start position:0% +AE and that was kind of like broadening +their worldview like even if you went to + + align:start position:0% +their worldview like even if you went to + + + align:start position:0% +their worldview like even if you went to +the school and didn't speak any you are + + align:start position:0% +the school and didn't speak any you are + + + align:start position:0% +the school and didn't speak any you are +learning about a new language that you + + align:start position:0% +learning about a new language that you + + + align:start position:0% +learning about a new language that you +weren't familiar with and so they were + + align:start position:0% +weren't familiar with and so they were + + + align:start position:0% +weren't familiar with and so they were +able to do this through them inspiratory + + align:start position:0% +able to do this through them inspiratory + + + align:start position:0% +able to do this through them inspiratory +literacy what the + + align:start position:0% + + + + align:start position:0% + +so kind of just play devil's advocate a + + align:start position:0% +so kind of just play devil's advocate a + + + align:start position:0% +so kind of just play devil's advocate a +little bit I think I guess one of the + + align:start position:0% +little bit I think I guess one of the + + + align:start position:0% +little bit I think I guess one of the +dangers of emancipatory + + align:start position:0% +dangers of emancipatory + + + align:start position:0% +dangers of emancipatory +that receipt might be kind of this non + + align:start position:0% +that receipt might be kind of this non + + + align:start position:0% +that receipt might be kind of this non +standardization like with initiatives + + align:start position:0% +standardization like with initiatives + + + align:start position:0% +standardization like with initiatives +like common core things like that we + + align:start position:0% +like common core things like that we + + + align:start position:0% +like common core things like that we +kind of have an educational system that + + align:start position:0% +kind of have an educational system that + + + align:start position:0% +kind of have an educational system that +setup so that everybody's kind of put on + + align:start position:0% +setup so that everybody's kind of put on + + + align:start position:0% +setup so that everybody's kind of put on +the same level to some extent like + + align:start position:0% +the same level to some extent like + + + align:start position:0% +the same level to some extent like +everybody has that same kind of baseline + + align:start position:0% +everybody has that same kind of baseline + + + align:start position:0% +everybody has that same kind of baseline +education but like with emancipatory + + align:start position:0% +education but like with emancipatory + + + align:start position:0% +education but like with emancipatory +literacy i think you're gonna find my + + align:start position:0% +literacy i think you're gonna find my + + + align:start position:0% +literacy i think you're gonna find my +educational programs are geared towards + + align:start position:0% +educational programs are geared towards + + + align:start position:0% +educational programs are geared towards +a specific like cultural norms and + + align:start position:0% +a specific like cultural norms and + + + align:start position:0% +a specific like cultural norms and +things that nature related to whatever + + align:start position:0% +things that nature related to whatever + + + align:start position:0% +things that nature related to whatever +population and targets so I wonder if + + align:start position:0% +population and targets so I wonder if + + + align:start position:0% +population and targets so I wonder if +that could potentially produce a system + + align:start position:0% +that could potentially produce a system + + + align:start position:0% +that could potentially produce a system +in which certain students even though + + align:start position:0% +in which certain students even though + + + align:start position:0% +in which certain students even though +they're receiving an education eyes + + align:start position:0% +they're receiving an education eyes + + + align:start position:0% +they're receiving an education eyes +appeared towards them it's objectively + + align:start position:0% +appeared towards them it's objectively + + + align:start position:0% +appeared towards them it's objectively +not that same quality of students who + + align:start position:0% +not that same quality of students who + + + align:start position:0% +not that same quality of students who +are would seem like more of a + + align:start position:0% +are would seem like more of a + + + align:start position:0% +are would seem like more of a +traditional approach I want to push back + + align:start position:0% +traditional approach I want to push back + + + align:start position:0% +traditional approach I want to push back +on that just a little bit because I + + align:start position:0% +on that just a little bit because I + + + align:start position:0% +on that just a little bit because I +think that the standardized approach to + + align:start position:0% +think that the standardized approach to + + + align:start position:0% +think that the standardized approach to +education is the approach that's been + + align:start position:0% +education is the approach that's been + + + align:start position:0% +education is the approach that's been +taken with the you know teach for test + + align:start position:0% +taken with the you know teach for test + + + align:start position:0% +taken with the you know teach for test +approach and it's failed it's been + + align:start position:0% +approach and it's failed it's been + + + align:start position:0% +approach and it's failed it's been +failing for a while now and I think that + + align:start position:0% +failing for a while now and I think that + + + align:start position:0% +failing for a while now and I think that +a lot of people in education policy and + + align:start position:0% +a lot of people in education policy and + + + align:start position:0% +a lot of people in education policy and +even just teachers are recognizing that + + align:start position:0% +even just teachers are recognizing that + + + align:start position:0% +even just teachers are recognizing that +now and I think that education + + align:start position:0% +now and I think that education + + + align:start position:0% +now and I think that education +emancipatory literacy gives us an + + align:start position:0% +emancipatory literacy gives us an + + + align:start position:0% +emancipatory literacy gives us an +interesting lens to think about how to + + align:start position:0% +interesting lens to think about how to + + + align:start position:0% +interesting lens to think about how to +educate people so that they can learn + + align:start position:0% +educate people so that they can learn + + + align:start position:0% +educate people so that they can learn +and I think maybe another place we can + + align:start position:0% +and I think maybe another place we can + + + align:start position:0% +and I think maybe another place we can +start kind of investing energy is + + align:start position:0% +start kind of investing energy is + + + align:start position:0% +start kind of investing energy is +thinking of ways in society that we can + + align:start position:0% +thinking of ways in society that we can + + + align:start position:0% +thinking of ways in society that we can +value those different ways of knowing + + align:start position:0% +value those different ways of knowing + + + align:start position:0% +value those different ways of knowing +and being and learning so that it's not + + align:start position:0% +and being and learning so that it's not + + + align:start position:0% +and being and learning so that it's not +just uh you went to college so you + + align:start position:0% +just uh you went to college so you + + + align:start position:0% +just uh you went to college so you +deserve to be paid a lot of money kind + + align:start position:0% +deserve to be paid a lot of money kind + + + align:start position:0% +deserve to be paid a lot of money kind +of thing and it's uh oh you can you know + + align:start position:0% +of thing and it's uh oh you can you know + + + align:start position:0% +of thing and it's uh oh you can you know +build the table from scratch how do you + + align:start position:0% +build the table from scratch how do you + + + align:start position:0% +build the table from scratch how do you +get paid to do that + + align:start position:0% + + + + align:start position:0% + +I think MIT is way far the tradition MIT + + align:start position:0% +I think MIT is way far the tradition MIT + + + align:start position:0% +I think MIT is way far the tradition MIT +is the alt-right of traditional + + align:start position:0% +is the alt-right of traditional + + + align:start position:0% +is the alt-right of traditional +literature I just think that there are I + + align:start position:0% +literature I just think that there are I + + + align:start position:0% +literature I just think that there are I +think that the the immense pressure that + + align:start position:0% +think that the the immense pressure that + + + align:start position:0% +think that the the immense pressure that +falls on students just on students + + align:start position:0% +falls on students just on students + + + align:start position:0% +falls on students just on students +physical bodies is definitely a symptom + + align:start position:0% +physical bodies is definitely a symptom + + + align:start position:0% +physical bodies is definitely a symptom +of a larger problem and for me the fact + + align:start position:0% +of a larger problem and for me the fact + + + align:start position:0% +of a larger problem and for me the fact +that that symptom is not enough of an + + align:start position:0% +that that symptom is not enough of an + + + align:start position:0% +that that symptom is not enough of an +impedance to change is heartbreaking + + align:start position:0% +impedance to change is heartbreaking + + + align:start position:0% +impedance to change is heartbreaking +because I think that I did I didn't I + + align:start position:0% +because I think that I did I didn't I + + + align:start position:0% +because I think that I did I didn't I +didn't come to college expecting it to + + align:start position:0% +didn't come to college expecting it to + + + align:start position:0% +didn't come to college expecting it to +be the four best four years of my life + + align:start position:0% +be the four best four years of my life + + + align:start position:0% +be the four best four years of my life +but I didn't come here also expecting to + + align:start position:0% +but I didn't come here also expecting to + + + align:start position:0% +but I didn't come here also expecting to +this suffering I think that there's + + align:start position:0% +this suffering I think that there's + + + align:start position:0% +this suffering I think that there's +definitely got to be a way where I can + + align:start position:0% +definitely got to be a way where I can + + + align:start position:0% +definitely got to be a way where I can +can bloom can reach my best potential + + align:start position:0% +can bloom can reach my best potential + + + align:start position:0% +can bloom can reach my best potential +and I love learning I love like I loved + + align:start position:0% +and I love learning I love like I loved + + + align:start position:0% +and I love learning I love like I loved +school you know and the fact that I yeah + + align:start position:0% +school you know and the fact that I yeah + + + align:start position:0% +school you know and the fact that I yeah +I have just kept running up against the + + align:start position:0% +I have just kept running up against the + + + align:start position:0% +I have just kept running up against the +institution I think as a creative person + + align:start position:0% +institution I think as a creative person + + + align:start position:0% +institution I think as a creative person +has made me kind of step back and think + + align:start position:0% +has made me kind of step back and think + + + align:start position:0% +has made me kind of step back and think +again about events but sorry literacy + + align:start position:0% +again about events but sorry literacy + + + align:start position:0% +again about events but sorry literacy +and how I can do that + + align:start position:0% +and how I can do that + + + align:start position:0% +and how I can do that +after given what you just said I want + + align:start position:0% +after given what you just said I want + + + align:start position:0% +after given what you just said I want +you to issue it to be mit president what + + align:start position:0% +you to issue it to be mit president what + + + align:start position:0% +you to issue it to be mit president what +would you change what how would you make + + align:start position:0% +would you change what how would you make + + + align:start position:0% +would you change what how would you make +it better + + align:start position:0% +it better + + + align:start position:0% +it better +more individually keeping in mind that + + align:start position:0% +more individually keeping in mind that + + + align:start position:0% +more individually keeping in mind that +maybe a certain cause I just reach in + + align:start position:0% +maybe a certain cause I just reach in + + + align:start position:0% +maybe a certain cause I just reach in +terms of a chemist how would you do that + + align:start position:0% +terms of a chemist how would you do that + + + align:start position:0% +terms of a chemist how would you do that +how would you how would you advise the + + align:start position:0% +how would you how would you advise the + + + align:start position:0% +how would you how would you advise the +ministration I think the very first + + align:start position:0% +ministration I think the very first + + + align:start position:0% +ministration I think the very first +thing I would do is have people who are + + align:start position:0% +thing I would do is have people who are + + + align:start position:0% +thing I would do is have people who are +more interested in research and not be + + align:start position:0% +more interested in research and not be + + + align:start position:0% +more interested in research and not be +professors so the ones who are + + align:start position:0% +professors so the ones who are + + + align:start position:0% +professors so the ones who are +interested in research should be doing + + align:start position:0% +interested in research should be doing + + + align:start position:0% +interested in research should be doing +research full-time and the people who + + align:start position:0% +research full-time and the people who + + + align:start position:0% +research full-time and the people who +are interested in teaching should teach + + align:start position:0% +are interested in teaching should teach + + + align:start position:0% +are interested in teaching should teach +because I think that that gives like a + + align:start position:0% +because I think that that gives like a + + + align:start position:0% +because I think that that gives like a +that gives people more impetus to just + + align:start position:0% +that gives people more impetus to just + + + align:start position:0% +that gives people more impetus to just +like connect with their students and + + align:start position:0% +like connect with their students and + + + align:start position:0% +like connect with their students and +actually get to know them and I think in + + align:start position:0% +actually get to know them and I think in + + + align:start position:0% +actually get to know them and I think in +that kind of environment you would + + align:start position:0% +that kind of environment you would + + + align:start position:0% +that kind of environment you would +foster like a safer healthier + + align:start position:0% +foster like a safer healthier + + + align:start position:0% +foster like a safer healthier +environment for learning whereas if you + + align:start position:0% +environment for learning whereas if you + + + align:start position:0% +environment for learning whereas if you +have a professor who is more interested + + align:start position:0% +have a professor who is more interested + + + align:start position:0% +have a professor who is more interested +in like winning the Nobel Prize like + + align:start position:0% +in like winning the Nobel Prize like + + + align:start position:0% +in like winning the Nobel Prize like +what are you like what do you do coming + + align:start position:0% +what are you like what do you do coming + + + align:start position:0% +what are you like what do you do coming +up against that I also would have MIT + + align:start position:0% +up against that I also would have MIT + + + align:start position:0% +up against that I also would have MIT +think very very hard about where the + + align:start position:0% +think very very hard about where the + + + align:start position:0% +think very very hard about where the +funding is coming from what it's going + + align:start position:0% +funding is coming from what it's going + + + align:start position:0% +funding is coming from what it's going +to and how that kind of fits in a global + + align:start position:0% +to and how that kind of fits in a global + + + align:start position:0% +to and how that kind of fits in a global +system where MIT as an institution fits + + align:start position:0% +system where MIT as an institution fits + + + align:start position:0% +system where MIT as an institution fits +in the global system as kind of + + align:start position:0% +in the global system as kind of + + + align:start position:0% +in the global system as kind of +not only an institution that does propel + + align:start position:0% +not only an institution that does propel + + + align:start position:0% +not only an institution that does propel +you to a higher class but kind of does + + align:start position:0% +you to a higher class but kind of does + + + align:start position:0% +you to a higher class but kind of does +that at the expense of a lot of other + + align:start position:0% +that at the expense of a lot of other + + + align:start position:0% +that at the expense of a lot of other +people and systems across the globe even + + align:start position:0% +people and systems across the globe even + + + align:start position:0% +people and systems across the globe even +if it's not directly in the area so I + + align:start position:0% +if it's not directly in the area so I + + + align:start position:0% +if it's not directly in the area so I +think that being more critical and + + align:start position:0% +think that being more critical and + + + align:start position:0% +think that being more critical and +intentional about our values and also + + align:start position:0% +intentional about our values and also + + + align:start position:0% +intentional about our values and also +maybe adding soul to the end of that the + + align:start position:0% +maybe adding soul to the end of that the + + + align:start position:0% +maybe adding soul to the end of that the +end of that of motto the last question + + align:start position:0% +end of that of motto the last question + + + align:start position:0% +end of that of motto the last question +is from your personal experiences or + + align:start position:0% +is from your personal experiences or + + + align:start position:0% +is from your personal experiences or +what you've seen or read about how do + + align:start position:0% +what you've seen or read about how do + + + align:start position:0% +what you've seen or read about how do +you think we can improve students + + align:start position:0% +you think we can improve students + + + align:start position:0% +you think we can improve students +experiences and confidence through + + align:start position:0% +experiences and confidence through + + + align:start position:0% +experiences and confidence through +intentional language use in schools like + + align:start position:0% +intentional language use in schools like + + + align:start position:0% +intentional language use in schools like +what mottos do you think are working or + + align:start position:0% +what mottos do you think are working or + + + align:start position:0% +what mottos do you think are working or +would work but it struggles to secure + + align:start position:0% +would work but it struggles to secure + + + align:start position:0% +would work but it struggles to secure +funding because it also doesn't follow a + + align:start position:0% +funding because it also doesn't follow a + + + align:start position:0% +funding because it also doesn't follow a +standardized Canadian curriculum in fact + + align:start position:0% +standardized Canadian curriculum in fact + + + align:start position:0% +standardized Canadian curriculum in fact +the community has sort of decolonized + + align:start position:0% +the community has sort of decolonized + + + align:start position:0% +the community has sort of decolonized +the curriculum and they teach history + + align:start position:0% +the curriculum and they teach history + + + align:start position:0% +the curriculum and they teach history +for instance not Canadian history they + + align:start position:0% +for instance not Canadian history they + + + align:start position:0% +for instance not Canadian history they +teach Mohawk history and it's been + + align:start position:0% +teach Mohawk history and it's been + + + align:start position:0% +teach Mohawk history and it's been +really affirming for children in the + + align:start position:0% +really affirming for children in the + + + align:start position:0% +really affirming for children in the +community especially a community that + + align:start position:0% +community especially a community that + + + align:start position:0% +community especially a community that +has its own struggles with language + + align:start position:0% +has its own struggles with language + + + align:start position:0% +has its own struggles with language +preservation and revitalization and + + align:start position:0% +preservation and revitalization and + + + align:start position:0% +preservation and revitalization and +passing on the language to continue + + align:start position:0% +passing on the language to continue + + + align:start position:0% +passing on the language to continue +generations especially after a history + + align:start position:0% +generations especially after a history + + + align:start position:0% +generations especially after a history +of residential schooling that you know + + align:start position:0% +of residential schooling that you know + + + align:start position:0% +of residential schooling that you know +main aim was a cultural and linguistic + + align:start position:0% +main aim was a cultural and linguistic + + + align:start position:0% +main aim was a cultural and linguistic +genocide of these people so this is a + + align:start position:0% +genocide of these people so this is a + + + align:start position:0% +genocide of these people so this is a +great model but it's funded entirely by + + align:start position:0% +great model but it's funded entirely by + + + align:start position:0% +great model but it's funded entirely by +a community + + align:start position:0% +a community + + + align:start position:0% +a community +razors and every year struggles with + + align:start position:0% +razors and every year struggles with + + + align:start position:0% +razors and every year struggles with +staying open and it's never certain that + + align:start position:0% +staying open and it's never certain that + + + align:start position:0% +staying open and it's never certain that +it'll be there in the next school year + + align:start position:0% +it'll be there in the next school year + + + align:start position:0% +it'll be there in the next school year +but it seems to have had a really really + + align:start position:0% +but it seems to have had a really really + + + align:start position:0% +but it seems to have had a really really +positive impact on the Mohawk community + + align:start position:0% +positive impact on the Mohawk community + + + align:start position:0% +positive impact on the Mohawk community +in Canada and so programs like that I + + align:start position:0% +in Canada and so programs like that I + + + align:start position:0% +in Canada and so programs like that I +think need to now be funded and that + + align:start position:0% +think need to now be funded and that + + + align:start position:0% +think need to now be funded and that +that involves challenging our our + + align:start position:0% +that involves challenging our our + + + align:start position:0% +that involves challenging our our +federal and local requirements not for + + align:start position:0% +federal and local requirements not for + + + align:start position:0% +federal and local requirements not for +funding and to do that we need to + + align:start position:0% +funding and to do that we need to + + + align:start position:0% +funding and to do that we need to +interrogate what value there is in the + + align:start position:0% +interrogate what value there is in the + + + align:start position:0% +interrogate what value there is in the +curricula we have standardized and why + + align:start position:0% +curricula we have standardized and why + + + align:start position:0% +curricula we have standardized and why +that is considered objectively like the + + align:start position:0% +that is considered objectively like the + + + align:start position:0% +that is considered objectively like the +standard that should impart the best + + align:start position:0% +standard that should impart the best + + + align:start position:0% +standard that should impart the best +learning experience upon students + + align:start position:0% + + + + align:start position:0% + +go ahead Colleen so bouncing up that and + + align:start position:0% +go ahead Colleen so bouncing up that and + + + align:start position:0% +go ahead Colleen so bouncing up that and +seems like we get to like ensuring the + + align:start position:0% +seems like we get to like ensuring the + + + align:start position:0% +seems like we get to like ensuring the +anything where the next platitudinous is + + align:start position:0% +anything where the next platitudinous is + + + align:start position:0% +anything where the next platitudinous is +inculcated in this like standard + + align:start position:0% +inculcated in this like standard + + + align:start position:0% +inculcated in this like standard +spherical goes into society and then way + + align:start position:0% +spherical goes into society and then way + + + align:start position:0% +spherical goes into society and then way +perpetuates a static critical back on V + + align:start position:0% +perpetuates a static critical back on V + + + align:start position:0% +perpetuates a static critical back on V +M students so I'm curious about if + + align:start position:0% +M students so I'm curious about if + + + align:start position:0% +M students so I'm curious about if +anyone has thoughts about how you could + + align:start position:0% +anyone has thoughts about how you could + + + align:start position:0% +anyone has thoughts about how you could +make knowledge about because one of the + + align:start position:0% +make knowledge about because one of the + + + align:start position:0% +make knowledge about because one of the +main hurdle is see the like instituting + + align:start position:0% +main hurdle is see the like instituting + + + align:start position:0% +main hurdle is see the like instituting +there's like entire continuation + + align:start position:0% +there's like entire continuation + + + align:start position:0% +there's like entire continuation +strictly chief about how the story of + + align:start position:0% +strictly chief about how the story of + + + align:start position:0% +strictly chief about how the story of +America's history has been with Garvey + + align:start position:0% +America's history has been with Garvey + + + align:start position:0% +America's history has been with Garvey +native and genocide slavery and the for + + align:start position:0% +native and genocide slavery and the for + + + align:start position:0% +native and genocide slavery and the for +lack of ever mean that is and best + + align:start position:0% +lack of ever mean that is and best + + + align:start position:0% +lack of ever mean that is and best +estimate how do you make people aware of + + align:start position:0% +estimate how do you make people aware of + + + align:start position:0% +estimate how do you make people aware of +that on a level that they can see those + + align:start position:0% +that on a level that they can see those + + + align:start position:0% +that on a level that they can see those +things playing out to pay and work to + + align:start position:0% +things playing out to pay and work to + + + align:start position:0% +things playing out to pay and work to +interior that curriculum especially + + align:start position:0% +interior that curriculum especially + + + align:start position:0% +interior that curriculum especially +they're coming from a background where + + align:start position:0% +they're coming from a background where + + + align:start position:0% +they're coming from a background where +like racism talk about center because + + align:start position:0% +like racism talk about center because + + + align:start position:0% +like racism talk about center because +it's an uncomfortable topic or if + + align:start position:0% +it's an uncomfortable topic or if + + + align:start position:0% +it's an uncomfortable topic or if +they're just like haven't heard about + + align:start position:0% + + + + align:start position:0% + +her manipulative clothes on to the where + + align:start position:0% +her manipulative clothes on to the where + + + align:start position:0% +her manipulative clothes on to the where +do you learn to interrogate your own + + align:start position:0% +do you learn to interrogate your own + + + align:start position:0% +do you learn to interrogate your own +beliefs and I feel like that's hard to + + align:start position:0% +beliefs and I feel like that's hard to + + + align:start position:0% +beliefs and I feel like that's hard to +find and I came to this class was like a + + align:start position:0% +find and I came to this class was like a + + + align:start position:0% +find and I came to this class was like a +key part of that for me and I don't know + + align:start position:0% +key part of that for me and I don't know + + + align:start position:0% +key part of that for me and I don't know +if that was because I got started up or + + align:start position:0% +if that was because I got started up or + + + align:start position:0% +if that was because I got started up or +just like I happened to stumble upon a + + align:start position:0% +just like I happened to stumble upon a + + + align:start position:0% +just like I happened to stumble upon a +place where I learned a Tara gave my + + align:start position:0% +place where I learned a Tara gave my + + + align:start position:0% +place where I learned a Tara gave my +beliefs but this isn't that a permit for + + align:start position:0% +beliefs but this isn't that a permit for + + + align:start position:0% +beliefs but this isn't that a permit for +themselves but I don't really have an + + align:start position:0% +themselves but I don't really have an + + + align:start position:0% +themselves but I don't really have an +answer for how we get choked with a + + align:start position:0% +answer for how we get choked with a + + + align:start position:0% +answer for how we get choked with a +value of interrogating kovalyonok how + + align:start position:0% +value of interrogating kovalyonok how + + + align:start position:0% +value of interrogating kovalyonok how +much more enriched your life is gonna be + + align:start position:0% +much more enriched your life is gonna be + + + align:start position:0% +much more enriched your life is gonna be +like you're just knocking off of that + + align:start position:0% +like you're just knocking off of that + + + align:start position:0% +like you're just knocking off of that +economy and possibly how do we have + + align:start position:0% +economy and possibly how do we have + + + align:start position:0% +economy and possibly how do we have +conversations with people who don't want + + align:start position:0% +conversations with people who don't want + + + align:start position:0% +conversations with people who don't want +to have this conversation and I think + + align:start position:0% +to have this conversation and I think + + + align:start position:0% +to have this conversation and I think +like the only way for them to figure out + + align:start position:0% +like the only way for them to figure out + + + align:start position:0% +like the only way for them to figure out +further to target yourselves but like + + align:start position:0% +further to target yourselves but like + + + align:start position:0% +further to target yourselves but like +most those people won't + + align:start position:0% +most those people won't + + + align:start position:0% +most those people won't +so like finding ways to tear it like to + + align:start position:0% +so like finding ways to tear it like to + + + align:start position:0% +so like finding ways to tear it like to +make them a target insult I think is it + + align:start position:0% +make them a target insult I think is it + + + align:start position:0% +make them a target insult I think is it +any like a common problem like + + align:start position:0% +any like a common problem like + + + align:start position:0% +any like a common problem like +throughout history and like + + align:start position:0% +throughout history and like + + + align:start position:0% +throughout history and like +unfortunately I don't know if I + + align:start position:0% +unfortunately I don't know if I + + + align:start position:0% +unfortunately I don't know if I +personally have a group like solution + + align:start position:0% +personally have a group like solution + + + align:start position:0% +personally have a group like solution +for that but I think like more + + align:start position:0% +for that but I think like more + + + align:start position:0% +for that but I think like more +opportunities like this I mean obviously + + align:start position:0% +opportunities like this I mean obviously + + + align:start position:0% +opportunities like this I mean obviously +like you mentioned this before like the + + align:start position:0% +like you mentioned this before like the + + + align:start position:0% +like you mentioned this before like the +people who are taking this class we're + + align:start position:0% +people who are taking this class we're + + + align:start position:0% +people who are taking this class we're +not really diversified in thought right + + align:start position:0% +not really diversified in thought right + + + align:start position:0% +not really diversified in thought right +like we all saw this class out mostly so + + align:start position:0% +like we all saw this class out mostly so + + + align:start position:0% +like we all saw this class out mostly so +I don't know how you can get someone who + + align:start position:0% +I don't know how you can get someone who + + + align:start position:0% +I don't know how you can get someone who +doesn't want to tarry saucily it was + + align:start position:0% +doesn't want to tarry saucily it was + + + align:start position:0% +doesn't want to tarry saucily it was +doing like this so maybe like mandating + + align:start position:0% +doing like this so maybe like mandating + + + align:start position:0% +doing like this so maybe like mandating +something like this where you have to go + + align:start position:0% +something like this where you have to go + + + align:start position:0% +something like this where you have to go +to like a black history class or a + + align:start position:0% +to like a black history class or a + + + align:start position:0% +to like a black history class or a +Native American history class or like + + align:start position:0% +Native American history class or like + + + align:start position:0% +Native American history class or like +whatever might force people to search + + align:start position:0% +whatever might force people to search + + + align:start position:0% +whatever might force people to search +yeah I almost think it might be better + + align:start position:0% +yeah I almost think it might be better + + + align:start position:0% +yeah I almost think it might be better +to not have a separate classroom this is + + align:start position:0% +to not have a separate classroom this is + + + align:start position:0% +to not have a separate classroom this is +your you know well-rounded miss class + + align:start position:0% +your you know well-rounded miss class + + + align:start position:0% +your you know well-rounded miss class +but this is when we're gonna learn about + + align:start position:0% +but this is when we're gonna learn about + + + align:start position:0% +but this is when we're gonna learn about +the others but to integrate what you + + align:start position:0% +the others but to integrate what you + + + align:start position:0% +the others but to integrate what you +would learn in a specific black history + + align:start position:0% +would learn in a specific black history + + + align:start position:0% +would learn in a specific black history +class into the general curriculum which + + align:start position:0% +class into the general curriculum which + + + align:start position:0% +class into the general curriculum which +of course is harder and but I do think + + align:start position:0% +of course is harder and but I do think + + + align:start position:0% +of course is harder and but I do think +would require the same amount of + + align:start position:0% +would require the same amount of + + + align:start position:0% +would require the same amount of +conversations and connections and + + align:start position:0% +conversations and connections and + + + align:start position:0% +conversations and connections and +negotiations as making a requirement you + + align:start position:0% +negotiations as making a requirement you + + + align:start position:0% +negotiations as making a requirement you +know of a separate class but I think + + align:start position:0% +know of a separate class but I think + + + align:start position:0% +know of a separate class but I think +that a better approach that might be + + align:start position:0% +that a better approach that might be + + + align:start position:0% +that a better approach that might be +more palatable and have more positive + + align:start position:0% +more palatable and have more positive + + + align:start position:0% +more palatable and have more positive +effects would be just turned up + + align:start position:0% +effects would be just turned up + + + align:start position:0% +effects would be just turned up +integration decolonizing the courage I + + align:start position:0% +integration decolonizing the courage I + + + align:start position:0% +integration decolonizing the courage I +told you I was gonna say I totally agree + + align:start position:0% +told you I was gonna say I totally agree + + + align:start position:0% +told you I was gonna say I totally agree +with Dana I think that um losing my + + align:start position:0% +with Dana I think that um losing my + + + align:start position:0% +with Dana I think that um losing my +train of thought I totally agree with + + align:start position:0% +train of thought I totally agree with + + + align:start position:0% +train of thought I totally agree with +Dana because I think that the history + + align:start position:0% +Dana because I think that the history + + + align:start position:0% +Dana because I think that the history +will speak for itself I think that + + align:start position:0% +will speak for itself I think that + + + align:start position:0% +will speak for itself I think that +history is like if you know they pulled + + align:start position:0% +history is like if you know they pulled + + + align:start position:0% +history is like if you know they pulled +a full history unlike the United States + + align:start position:0% +a full history unlike the United States + + + align:start position:0% +a full history unlike the United States +for example it's pretty it's pretty + + align:start position:0% +for example it's pretty it's pretty + + + align:start position:0% +for example it's pretty it's pretty +terrible and I think that you do need to + + align:start position:0% +terrible and I think that you do need to + + + align:start position:0% +terrible and I think that you do need to +know the whole history and also need to + + align:start position:0% +know the whole history and also need to + + + align:start position:0% +know the whole history and also need to +get the alternative sides and have those + + align:start position:0% +get the alternative sides and have those + + + align:start position:0% +get the alternative sides and have those +be like integrated into the curriculum I + + align:start position:0% +be like integrated into the curriculum I + + + align:start position:0% +be like integrated into the curriculum I +also was interested in I'm thinking + + align:start position:0% +also was interested in I'm thinking + + + align:start position:0% +also was interested in I'm thinking +about like entry points into these + + align:start position:0% +about like entry points into these + + + align:start position:0% +about like entry points into these +conversations in like ways that like art + + align:start position:0% +conversations in like ways that like art + + + align:start position:0% +conversations in like ways that like art +and humor can function as entry points + + align:start position:0% +and humor can function as entry points + + + align:start position:0% +and humor can function as entry points +in the conversations I've been having + + align:start position:0% +in the conversations I've been having + + + align:start position:0% +in the conversations I've been having +this conversation with a friend of mine + + align:start position:0% +this conversation with a friend of mine + + + align:start position:0% +this conversation with a friend of mine +of how like humor for example gives us a + + align:start position:0% +of how like humor for example gives us a + + + align:start position:0% +of how like humor for example gives us a +way to kind of express some of these + + align:start position:0% +way to kind of express some of these + + + align:start position:0% +way to kind of express some of these +things that are more taboo and kind of + + align:start position:0% +things that are more taboo and kind of + + + align:start position:0% +things that are more taboo and kind of +laughed them off and kind of like + + align:start position:0% +laughed them off and kind of like + + + align:start position:0% +laughed them off and kind of like +integrate them as opposed to everyone + + align:start position:0% +integrate them as opposed to everyone + + + align:start position:0% +integrate them as opposed to everyone +shutting them and people feeling bobbled + + align:start position:0% +shutting them and people feeling bobbled + + + align:start position:0% +shutting them and people feeling bobbled +so I am interested about like humor and + + align:start position:0% +so I am interested about like humor and + + + align:start position:0% +so I am interested about like humor and +art specifically as entry points into + + align:start position:0% +art specifically as entry points into + + + align:start position:0% +art specifically as entry points into +these conversations + + align:start position:0% + + + + align:start position:0% + +Nina I think what she'll say no way + + align:start position:0% +Nina I think what she'll say no way + + + align:start position:0% +Nina I think what she'll say no way +answers the concern that should be + + align:start position:0% +answers the concern that should be + + + align:start position:0% +answers the concern that should be +expressed right so the good should be + + align:start position:0% +expressed right so the good should be + + + align:start position:0% +expressed right so the good should be +put it 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person becomes much better in wind + + + align:start position:0% +white person becomes much better in wind +exit of the factors of why because the + + align:start position:0% +exit of the factors of why because the + + + align:start position:0% +exit of the factors of why because the +lenses are defined with with the + + align:start position:0% +lenses are defined with with the + + + align:start position:0% +lenses are defined with with the +dominant gaze of the white subject all + + align:start position:0% +dominant gaze of the white subject all + + + align:start position:0% +dominant gaze of the white subject all +right so in had to tweak it camera to + + align:start position:0% +right so in had to tweak it camera to + + + align:start position:0% +right so in had to tweak it camera to +make it take good pictures of black + + align:start position:0% +make it take good pictures of black + + + align:start position:0% +make it take good pictures of black +people so even there even in clean + + align:start position:0% +people so even there even in clean + + + align:start position:0% +people so even there even in clean +physics they should be a way to + + align:start position:0% +physics they should be a way to + + + align:start position:0% +physics they should be a way to +interrogate the the curriculum why + + align:start position:0% +interrogate the the curriculum why + + + align:start position:0% +interrogate the the curriculum why +internet in familial event a couple so + + align:start position:0% +internet in familial event a couple so + + + align:start position:0% +internet in familial event a couple so +in a way it could be both you could both + + align:start position:0% +in a way it could be both you could both + + + align:start position:0% +in a way it could be both you could both +have the military PTSD within the + + align:start position:0% +have the military PTSD within the + + + align:start position:0% +have the military PTSD within the +correct codes 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position:0% +they would look at a picture to decide +what kind of student you will become mr. + + align:start position:0% +what kind of student you will become mr. + + + align:start position:0% +what kind of student you will become mr. +physical traits like of the attention of + + align:start position:0% +physical traits like of the attention of + + + align:start position:0% +physical traits like of the attention of +the most out of what was called and + + align:start position:0% +the most out of what was called and + + + align:start position:0% +the most out of what was called and +phenology you know which is the measure + + align:start position:0% +phenology you know which is the measure + + + align:start position:0% +phenology you know which is the measure +so there is plenty plenty of room to + + align:start position:0% +so there is plenty plenty of room to + + + align:start position:0% +so there is plenty plenty of room to +integrate within I I want to express the + + align:start position:0% +integrate within I I want to express the + + + align:start position:0% +integrate within I I want to express the +fact that to do such a thing is not just + + align:start position:0% +fact that to do such a thing is not just + + + align:start position:0% +fact that to do such a thing is not just +to include all of the the hushed + + align:start position:0% +to include all of the the hushed + + + align:start position:0% +to include all of the the hushed +historical abuses that we glossed over + + align:start position:0% +historical abuses that we glossed over + + + align:start position:0% +historical abuses that we glossed over +in our current like curricula but it's + + align:start position:0% +in our current like curricula but it's + + + align:start position:0% +in our current like curricula but it's +also to to acknowledge the good that we + + align:start position:0% +also to to acknowledge the good that we + + + align:start position:0% +also to to acknowledge the good that we +have overlooked so discoveries and + + align:start position:0% +have overlooked so discoveries and + + + align:start position:0% +have overlooked so discoveries and +innovations that other people who are + + align:start position:0% +innovations that other people who are + + + align:start position:0% +innovations that other people who are +not quote-unquote Western and who are + + align:start position:0% +not quote-unquote Western and who are + + + align:start position:0% +not quote-unquote Western and who are +not an Anglo American have made and + + align:start position:0% +not an Anglo American have made and + + + align:start position:0% +not an Anglo American have made and +contributed to the fields of science and + + align:start position:0% +contributed to the fields of science and + + + align:start position:0% +contributed to the fields of science and +history and literature so not only to + + align:start position:0% +history and literature so not only to + + + align:start position:0% +history and literature so not only to +recognize you know visa star goal evils + + align:start position:0% +recognize you know visa star goal evils + + + align:start position:0% +recognize you know visa star goal evils +but also rather grand positive impacts + + align:start position:0% +but also rather grand positive impacts + + + align:start position:0% +but also rather grand positive impacts +that others have had okay + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/b-PoEwPoRe8.txt b/b-PoEwPoRe8.txt new file mode 100644 index 0000000000000000000000000000000000000000..a020f51f84b8cfa9b7ecddb363a2668ec6f28c07 --- /dev/null +++ b/b-PoEwPoRe8.txt @@ -0,0 +1,2888 @@ +align:start position:0% + +in the face of the challenges of climate + + align:start position:0% +in the face of the challenges of climate + + + align:start position:0% +in the face of the challenges of climate +change and depleting natural + + align:start position:0% +change and depleting natural + + + align:start position:0% +change and depleting natural +resources humans exploring feedable + + align:start position:0% +resources humans exploring feedable + + + align:start position:0% +resources humans exploring feedable +solutions to sustainable + + align:start position:0% +solutions to sustainable + + + align:start position:0% +solutions to sustainable +development Green Technology can can be + + align:start position:0% +development Green Technology can can be + + + align:start position:0% +development Green Technology can can be +one of the good + + align:start position:0% +one of the good + + + align:start position:0% +one of the good +options since 2009 Malaysia has been + + align:start position:0% +options since 2009 Malaysia has been + + + align:start position:0% +options since 2009 Malaysia has been +facilitating the application of Green + + align:start position:0% +facilitating the application of Green + + + align:start position:0% +facilitating the application of Green +Technology through implementing the + + align:start position:0% +Technology through implementing the + + + align:start position:0% +Technology through implementing the +national Green Technology + + align:start position:0% +national Green Technology + + + align:start position:0% +national Green Technology +policy over the centuries humans have + + align:start position:0% +policy over the centuries humans have + + + align:start position:0% +policy over the centuries humans have +tried to change the weather people have + + align:start position:0% +tried to change the weather people have + + + align:start position:0% +tried to change the weather people have +prayed and use strategies to get more + + align:start position:0% +prayed and use strategies to get more + + + align:start position:0% +prayed and use strategies to get more +rain and decrease the + + align:start position:0% +rain and decrease the + + + align:start position:0% +rain and decrease the +heat while we have not intentionally + + align:start position:0% +heat while we have not intentionally + + + align:start position:0% +heat while we have not intentionally +tried to change the climate we have + + align:start position:0% +tried to change the climate we have + + + align:start position:0% +tried to change the climate we have +unintentionally brought about changes + + align:start position:0% +unintentionally brought about changes + + + align:start position:0% +unintentionally brought about changes +that are affecting us + + align:start position:0% +that are affecting us + + + align:start position:0% +that are affecting us +today starting in the middle + + align:start position:0% +today starting in the middle + + + align:start position:0% +today starting in the middle +1700s the Industrial Revolution and + + align:start position:0% +1700s the Industrial Revolution and + + + align:start position:0% +1700s the Industrial Revolution and +modern agricultural practice began to + + align:start position:0% +modern agricultural practice began to + + + align:start position:0% +modern agricultural practice began to +alter the amount of human created carbon + + align:start position:0% +alter the amount of human created carbon + + + align:start position:0% +alter the amount of human created carbon +dioxide emissions in the + + align:start position:0% +dioxide emissions in the + + + align:start position:0% +dioxide emissions in the +atmosphere Global carbon dioxide + + align:start position:0% +atmosphere Global carbon dioxide + + + align:start position:0% +atmosphere Global carbon dioxide +emissions have been rising at an annual + + align:start position:0% +emissions have been rising at an annual + + + align:start position:0% +emissions have been rising at an annual +average of + + align:start position:0% +average of + + + align:start position:0% +average of +2.7% during the past decade countries + + align:start position:0% +2.7% during the past decade countries + + + align:start position:0% +2.7% during the past decade countries +all the world I use different techniques + + align:start position:0% +all the world I use different techniques + + + align:start position:0% +all the world I use different techniques +to reduce carbon + + align:start position:0% +to reduce carbon + + + align:start position:0% +to reduce carbon +emissions these include establishing + + align:start position:0% +emissions these include establishing + + + align:start position:0% +emissions these include establishing +carbon markets creating policy and + + align:start position:0% +carbon markets creating policy and + + + align:start position:0% +carbon markets creating policy and +legislation and Green + + align:start position:0% +legislation and Green + + + align:start position:0% +legislation and Green +Technology my research have focus on + + align:start position:0% +Technology my research have focus on + + + align:start position:0% +Technology my research have focus on +Green Technology in + + align:start position:0% +Green Technology in + + + align:start position:0% +Green Technology in +Malaysia but do you know what Green + + align:start position:0% +Malaysia but do you know what Green + + + align:start position:0% +Malaysia but do you know what Green +Technology is Green Technology is a + + align:start position:0% +Technology is Green Technology is a + + + align:start position:0% +Technology is Green Technology is a +development and application of products + + align:start position:0% +development and application of products + + + align:start position:0% +development and application of products +equipment and system + + align:start position:0% +equipment and system + + + align:start position:0% +equipment and system +that conserve natural + + align:start position:0% +that conserve natural + + + align:start position:0% +that conserve natural +resources which minimizes and reduce + + align:start position:0% +resources which minimizes and reduce + + + align:start position:0% +resources which minimizes and reduce +negative environmental impact of human + + align:start position:0% +negative environmental impact of human + + + align:start position:0% +negative environmental impact of human +activities what makes the technology + + align:start position:0% +activities what makes the technology + + + align:start position:0% +activities what makes the technology +green it minimize environmental + + align:start position:0% +green it minimize environmental + + + align:start position:0% +green it minimize environmental +degradation it has zero or low green gas + + align:start position:0% +degradation it has zero or low green gas + + + align:start position:0% +degradation it has zero or low green gas +emissions it is safe to use and promotes + + align:start position:0% +emissions it is safe to use and promotes + + + align:start position:0% +emissions it is safe to use and promotes +a healthy environmental for all life + + align:start position:0% +a healthy environmental for all life + + + align:start position:0% +a healthy environmental for all life +firms it conserves energy and natural + + align:start position:0% +firms it conserves energy and natural + + + align:start position:0% +firms it conserves energy and natural +resources + + align:start position:0% +resources + + + align:start position:0% +resources +it relies on renewable + + align:start position:0% +it relies on renewable + + + align:start position:0% +it relies on renewable +resources Green Technology is not New + + align:start position:0% +resources Green Technology is not New + + + align:start position:0% +resources Green Technology is not New +Concept people have been trying to go + + align:start position:0% +Concept people have been trying to go + + + align:start position:0% +Concept people have been trying to go +grein for decades including using wind + + align:start position:0% +grein for decades including using wind + + + align:start position:0% +grein for decades including using wind +Motors wind turbines solar power plants + + align:start position:0% +Motors wind turbines solar power plants + + + align:start position:0% +Motors wind turbines solar power plants +and other alternative energy ideas in + + align:start position:0% +and other alternative energy ideas in + + + align:start position:0% +and other alternative energy ideas in +keeping with global Trends Malaysia has + + align:start position:0% +keeping with global Trends Malaysia has + + + align:start position:0% +keeping with global Trends Malaysia has +recently proactively promoted and adopt + + align:start position:0% +recently proactively promoted and adopt + + + align:start position:0% +recently proactively promoted and adopt +Green Technology in 2009 + + align:start position:0% +Green Technology in 2009 + + + align:start position:0% +Green Technology in 2009 +Malaysia established the country's + + align:start position:0% +Malaysia established the country's + + + align:start position:0% +Malaysia established the country's +Ministry of energy Green Technology and + + align:start position:0% +Ministry of energy Green Technology and + + + align:start position:0% +Ministry of energy Green Technology and +water also called Kaa in Malay and + + align:start position:0% +water also called Kaa in Malay and + + + align:start position:0% +water also called Kaa in Malay and +adopted National Green Technology + + align:start position:0% +adopted National Green Technology + + + align:start position:0% +adopted National Green Technology +policy the main goal is to contribute to + + align:start position:0% +policy the main goal is to contribute to + + + align:start position:0% +policy the main goal is to contribute to +economic growth and to reduce Malaysia's + + align:start position:0% +economic growth and to reduce Malaysia's + + + align:start position:0% +economic growth and to reduce Malaysia's +carbon footprint the objective of the + + align:start position:0% +carbon footprint the objective of the + + + align:start position:0% +carbon footprint the objective of the +policy is to connect industrial and + + align:start position:0% +policy is to connect industrial and + + + align:start position:0% +policy is to connect industrial and +government through supporting green + + align:start position:0% +government through supporting green + + + align:start position:0% +government through supporting green +buildings Green Transportation renewable + + align:start position:0% +buildings Green Transportation renewable + + + align:start position:0% +buildings Green Transportation renewable +energy use which and Water Management + + align:start position:0% +energy use which and Water Management + + + align:start position:0% +energy use which and Water Management +the most important components of this + + align:start position:0% +the most important components of this + + + align:start position:0% +the most important components of this +policy include setting up institutions + + align:start position:0% +policy include setting up institutions + + + align:start position:0% +policy include setting up institutions +and launching fiscal instruments setting + + align:start position:0% +and launching fiscal instruments setting + + + align:start position:0% +and launching fiscal instruments setting +up institutions is a key strategy in the + + align:start position:0% +up institutions is a key strategy in the + + + align:start position:0% +up institutions is a key strategy in the +policy since Green Technology involves + + align:start position:0% +policy since Green Technology involves + + + align:start position:0% +policy since Green Technology involves +many different sectors it is important + + align:start position:0% +many different sectors it is important + + + align:start position:0% +many different sectors it is important +to have a structure that involves all + + align:start position:0% +to have a structure that involves all + + + align:start position:0% +to have a structure that involves all +the relevant stakeholders to ensure + + align:start position:0% +the relevant stakeholders to ensure + + + align:start position:0% +the relevant stakeholders to ensure +consensus and support the national green + + align:start position:0% +consensus and support the national green + + + align:start position:0% +consensus and support the national green +technology and climate change Council + + align:start position:0% +technology and climate change Council + + + align:start position:0% +technology and climate change Council +coordinates Green Technology issues + + align:start position:0% +coordinates Green Technology issues + + + align:start position:0% +coordinates Green Technology issues +between the Ministries agencies the + + align:start position:0% +between the Ministries agencies the + + + align:start position:0% +between the Ministries agencies the +private sector and other stakeholders + + align:start position:0% +private sector and other stakeholders + + + align:start position:0% +private sector and other stakeholders +that Implement + + align:start position:0% +that Implement + + + align:start position:0% +that Implement +policies in addition the agencies that + + align:start position:0% +policies in addition the agencies that + + + align:start position:0% +policies in addition the agencies that +assist and contribute to development of + + align:start position:0% +assist and contribute to development of + + + align:start position:0% +assist and contribute to development of +Green Technology like the Green + + align:start position:0% +Green Technology like the Green + + + align:start position:0% +Green Technology like the Green +Technology Corporation as a focal point + + align:start position:0% +Technology Corporation as a focal point + + + align:start position:0% +Technology Corporation as a focal point +for Green Technology development in + + align:start position:0% +for Green Technology development in + + + align:start position:0% +for Green Technology development in +Malaysia Green Technology cooperation + + align:start position:0% +Malaysia Green Technology cooperation + + + align:start position:0% +Malaysia Green Technology cooperation +provide facilities and the services in + + align:start position:0% +provide facilities and the services in + + + align:start position:0% +provide facilities and the services in +advisory and consultancy and energy + + align:start position:0% +advisory and consultancy and energy + + + align:start position:0% +advisory and consultancy and energy +management and training Malaysia Green + + align:start position:0% +management and training Malaysia Green + + + align:start position:0% +management and training Malaysia Green +Technology Finance scheme is the most + + align:start position:0% +Technology Finance scheme is the most + + + align:start position:0% +Technology Finance scheme is the most +important fiscal instruments to attract + + align:start position:0% +important fiscal instruments to attract + + + align:start position:0% +important fiscal instruments to attract +private entities to use green + + align:start position:0% +private entities to use green + + + align:start position:0% +private entities to use green +technology this scheme is for both the + + align:start position:0% +technology this scheme is for both the + + + align:start position:0% +technology this scheme is for both the +users and producers of Green Technology + + align:start position:0% +users and producers of Green Technology + + + align:start position:0% +users and producers of Green Technology +it was initially started with a 1.5 + + align:start position:0% +it was initially started with a 1.5 + + + align:start position:0% +it was initially started with a 1.5 +billion R soft loan and has now + + align:start position:0% +billion R soft loan and has now + + + align:start position:0% +billion R soft loan and has now +increased to 3.5 5 billion rates the + + align:start position:0% +increased to 3.5 5 billion rates the + + + align:start position:0% +increased to 3.5 5 billion rates the +scheme offers a 2% interest subsidy and + + align:start position:0% +scheme offers a 2% interest subsidy and + + + align:start position:0% +scheme offers a 2% interest subsidy and +60% of the loan will be guaranteed by + + align:start position:0% +60% of the loan will be guaranteed by + + + align:start position:0% +60% of the loan will be guaranteed by +the government from 2009 to November + + align:start position:0% +the government from 2009 to November + + + align:start position:0% +the government from 2009 to November + + align:start position:0% + + + align:start position:0% +351 projects were covered by this schem + + align:start position:0% +351 projects were covered by this schem + + + align:start position:0% +351 projects were covered by this schem +including 243 Energy Efficiency projects + + align:start position:0% +including 243 Energy Efficiency projects + + + align:start position:0% +including 243 Energy Efficiency projects +17 green building projects 91 waste and + + align:start position:0% +17 green building projects 91 waste and + + + align:start position:0% +17 green building projects 91 waste and +water projects the majority of projects + + align:start position:0% +water projects the majority of projects + + + align:start position:0% +water projects the majority of projects +are located in in Kumo silano and + + align:start position:0% +are located in in Kumo silano and + + + align:start position:0% +are located in in Kumo silano and +jalo most of project focus on electrical + + align:start position:0% +jalo most of project focus on electrical + + + align:start position:0% +jalo most of project focus on electrical +electronics sub sector and bi technology + + align:start position:0% +electronics sub sector and bi technology + + + align:start position:0% +electronics sub sector and bi technology +sub sector besides action stipulated + + align:start position:0% +sub sector besides action stipulated + + + align:start position:0% +sub sector besides action stipulated +from the ministry level we can also see + + align:start position:0% +from the ministry level we can also see + + + align:start position:0% +from the ministry level we can also see +some progress at a regional level isanda + + align:start position:0% +some progress at a regional level isanda + + + align:start position:0% +some progress at a regional level isanda +Malaysia is an important economic + + align:start position:0% +Malaysia is an important economic + + + align:start position:0% +Malaysia is an important economic +Corridor in the southern part of + + align:start position:0% +Corridor in the southern part of + + + align:start position:0% +Corridor in the southern part of +penisula Malaysia it has recently begun + + align:start position:0% +penisula Malaysia it has recently begun + + + align:start position:0% +penisula Malaysia it has recently begun +low carbon programs the low carbon GR + + align:start position:0% +low carbon programs the low carbon GR + + + align:start position:0% +low carbon programs the low carbon GR +isanda Malaysia + + align:start position:0% +isanda Malaysia + + + align:start position:0% +isanda Malaysia +2025 was endorsed by the prime minister + + align:start position:0% +2025 was endorsed by the prime minister + + + align:start position:0% +2025 was endorsed by the prime minister +of Malaysia in December + + align:start position:0% +of Malaysia in December + + + align:start position:0% +of Malaysia in December +202 this blueprint was prepared by a + + align:start position:0% +202 this blueprint was prepared by a + + + align:start position:0% +202 this blueprint was prepared by a +group of urban planners and + + align:start position:0% +group of urban planners and + + + align:start position:0% +group of urban planners and +researchers Professor hon chinon from + + align:start position:0% +researchers Professor hon chinon from + + + align:start position:0% +researchers Professor hon chinon from +University technology Malaysia is a main + + align:start position:0% +University technology Malaysia is a main + + + align:start position:0% +University technology Malaysia is a main +member of this team I think Green + + align:start position:0% +member of this team I think Green + + + align:start position:0% +member of this team I think Green +Technology policy uh is a very important + + align:start position:0% +Technology policy uh is a very important + + + align:start position:0% +Technology policy uh is a very important +policy because uh it focus on the use of + + align:start position:0% +policy because uh it focus on the use of + + + align:start position:0% +policy because uh it focus on the use of +Green Technology in city building or + + align:start position:0% +Green Technology in city building or + + + align:start position:0% +Green Technology in city building or +City Planning so in our Contex here we + + align:start position:0% +City Planning so in our Contex here we + + + align:start position:0% +City Planning so in our Contex here we +are trying to uh use Energy Efficiency + + align:start position:0% +are trying to uh use Energy Efficiency + + + align:start position:0% +are trying to uh use Energy Efficiency +technology we are trying to use + + align:start position:0% +technology we are trying to use + + + align:start position:0% +technology we are trying to use +renewable energy uh technology and also + + align:start position:0% +renewable energy uh technology and also + + + align:start position:0% +renewable energy uh technology and also +recycling the solid waste management and + + align:start position:0% +recycling the solid waste management and + + + align:start position:0% +recycling the solid waste management and +others urban planning have to reconsider + + align:start position:0% +others urban planning have to reconsider + + + align:start position:0% +others urban planning have to reconsider +how to uh promote green technology or + + align:start position:0% +how to uh promote green technology or + + + align:start position:0% +how to uh promote green technology or +green energy or green transport or green + + align:start position:0% +green energy or green transport or green + + + align:start position:0% +green energy or green transport or green +industry in in in City Planning so I + + align:start position:0% +industry in in in City Planning so I + + + align:start position:0% +industry in in in City Planning so I +think this is a way forward for Malayan + + align:start position:0% +think this is a way forward for Malayan + + + align:start position:0% +think this is a way forward for Malayan +uh development also Malaysia has made + + align:start position:0% +uh development also Malaysia has made + + + align:start position:0% +uh development also Malaysia has made +progress in promoting Green Technology + + align:start position:0% +progress in promoting Green Technology + + + align:start position:0% +progress in promoting Green Technology +interviews with government officials + + align:start position:0% +interviews with government officials + + + align:start position:0% +interviews with government officials +researchers and Industrial firms show + + align:start position:0% +researchers and Industrial firms show + + + align:start position:0% +researchers and Industrial firms show +that many pieces are still missing first + + align:start position:0% +that many pieces are still missing first + + + align:start position:0% +that many pieces are still missing first +information about Green Technology and + + align:start position:0% +information about Green Technology and + + + align:start position:0% +information about Green Technology and +policies are still very limited I + + align:start position:0% +policies are still very limited I + + + align:start position:0% +policies are still very limited I +conducted a questionnaire in 15 + + align:start position:0% +conducted a questionnaire in 15 + + + align:start position:0% +conducted a questionnaire in 15 +factories it shows that one of the main + + align:start position:0% +factories it shows that one of the main + + + align:start position:0% +factories it shows that one of the main +barers for industrial firms to use green + + align:start position:0% +barers for industrial firms to use green + + + align:start position:0% +barers for industrial firms to use green +technology is information the government + + align:start position:0% +technology is information the government + + + align:start position:0% +technology is information the government +inent intention is good but some + + align:start position:0% +inent intention is good but some + + + align:start position:0% +inent intention is good but some +sometimes the are facing another + + align:start position:0% +sometimes the are facing another + + + align:start position:0% +sometimes the are facing another +challenges when it come to the Green + + align:start position:0% +challenges when it come to the Green + + + align:start position:0% +challenges when it come to the Green +Technology or green Industries you know + + align:start position:0% +Technology or green Industries you know + + + align:start position:0% +Technology or green Industries you know +sometime when we when we want to get + + align:start position:0% +sometime when we when we want to get + + + align:start position:0% +sometime when we when we want to get +someone to justify that you are in the + + align:start position:0% +someone to justify that you are in the + + + align:start position:0% +someone to justify that you are in the +green Industries so sometimes we cannot + + align:start position:0% +green Industries so sometimes we cannot + + + align:start position:0% +green Industries so sometimes we cannot +get the right person to confirm to + + align:start position:0% +get the right person to confirm to + + + align:start position:0% +get the right person to confirm to +justify that we are in that field + + align:start position:0% +justify that we are in that field + + + align:start position:0% +justify that we are in that field +sometime we may not be able to get the + + align:start position:0% +sometime we may not be able to get the + + + align:start position:0% +sometime we may not be able to get the +incentive that uh make provision to the + + align:start position:0% +incentive that uh make provision to the + + + align:start position:0% +incentive that uh make provision to the +assembly by the government so this is + + align:start position:0% +assembly by the government so this is + + + align:start position:0% +assembly by the government so this is +another challenge that we are facing uh + + align:start position:0% +another challenge that we are facing uh + + + align:start position:0% +another challenge that we are facing uh +some of this information may not have + + align:start position:0% +some of this information may not have + + + align:start position:0% +some of this information may not have +reached all the industrialist but I + + align:start position:0% +reached all the industrialist but I + + + align:start position:0% +reached all the industrialist but I +think the important part is actually + + align:start position:0% +think the important part is actually + + + align:start position:0% +think the important part is actually +this information have to be disseminated + + align:start position:0% +this information have to be disseminated + + + align:start position:0% +this information have to be disseminated +to a to a bigger group and then I think + + align:start position:0% +to a to a bigger group and then I think + + + align:start position:0% +to a to a bigger group and then I think +um uh we strongly feel that the Chamber + + align:start position:0% +um uh we strongly feel that the Chamber + + + align:start position:0% +um uh we strongly feel that the Chamber +of Commerce or + + align:start position:0% +of Commerce or + + + align:start position:0% +of Commerce or +industrial U association should work + + align:start position:0% +industrial U association should work + + + align:start position:0% +industrial U association should work +closely also trying to get to know more + + align:start position:0% +closely also trying to get to know more + + + align:start position:0% +closely also trying to get to know more +about this uh GRE Tech I think the the + + align:start position:0% +about this uh GRE Tech I think the the + + + align:start position:0% +about this uh GRE Tech I think the the +ministry themselves so know they they + + align:start position:0% +ministry themselves so know they they + + + align:start position:0% +ministry themselves so know they they +trying Ways and Means uh to disseminate + + align:start position:0% +trying Ways and Means uh to disseminate + + + align:start position:0% +trying Ways and Means uh to disseminate +this information so that actually more + + align:start position:0% +this information so that actually more + + + align:start position:0% +this information so that actually more +and more people have opportunity to + + align:start position:0% +and more people have opportunity to + + + align:start position:0% +and more people have opportunity to +access to this uh Green Tech fund did + + align:start position:0% +access to this uh Green Tech fund did + + + align:start position:0% +access to this uh Green Tech fund did +you heard about that Green Technology + + align:start position:0% +you heard about that Green Technology + + + align:start position:0% +you heard about that Green Technology +policy uh what what Green Technology I + + align:start position:0% +policy uh what what Green Technology I + + + align:start position:0% +policy uh what what Green Technology I +myself I I will like all the all these + + align:start position:0% +myself I I will like all the all these + + + align:start position:0% +myself I I will like all the all these +things clean energy now maybe they use + + align:start position:0% +things clean energy now maybe they use + + + align:start position:0% +things clean energy now maybe they use +more on this solar energy wind + + align:start position:0% +more on this solar energy wind + + + align:start position:0% +more on this solar energy wind +energy I think this is the two mean + + align:start position:0% +energy I think this is the two mean + + + align:start position:0% +energy I think this is the two mean +things they using now so solar energy + + align:start position:0% +things they using now so solar energy + + + align:start position:0% +things they using now so solar energy +actually I myself have using it now they + + align:start position:0% +actually I myself have using it now they + + + align:start position:0% +actually I myself have using it now they +use it for as a hobby but later on when + + align:start position:0% +use it for as a hobby but later on when + + + align:start position:0% +use it for as a hobby but later on when +I know more about it maybe I will use it + + align:start position:0% +I know more about it maybe I will use it + + + align:start position:0% +I know more about it maybe I will use it +uh partially to reduce my company's uh + + align:start position:0% +uh partially to reduce my company's uh + + + align:start position:0% +uh partially to reduce my company's uh +electricity to replace the supplies to + + align:start position:0% +electricity to replace the supplies to + + + align:start position:0% +electricity to replace the supplies to +cut down the cost secondly this is a + + align:start position:0% +cut down the cost secondly this is a + + + align:start position:0% +cut down the cost secondly this is a +mismatch between the needs of the firms + + align:start position:0% +mismatch between the needs of the firms + + + align:start position:0% +mismatch between the needs of the firms +and the focus of government programs + + align:start position:0% +and the focus of government programs + + + align:start position:0% +and the focus of government programs +according to the questionnaire + + align:start position:0% +according to the questionnaire + + + align:start position:0% +according to the questionnaire +industrial firms priorities were waste + + align:start position:0% +industrial firms priorities were waste + + + align:start position:0% +industrial firms priorities were waste +water energy utilization solid waste + + align:start position:0% +water energy utilization solid waste + + + align:start position:0% +water energy utilization solid waste +energy Supply and green buildings + + align:start position:0% +energy Supply and green buildings + + + align:start position:0% +energy Supply and green buildings +however most of the G incentives go to + + align:start position:0% +however most of the G incentives go to + + + align:start position:0% +however most of the G incentives go to +energy projects mostly for solar we feel + + align:start position:0% +energy projects mostly for solar we feel + + + align:start position:0% +energy projects mostly for solar we feel +that too much of empasis has been given + + align:start position:0% +that too much of empasis has been given + + + align:start position:0% +that too much of empasis has been given +to solar we are trying to look into + + align:start position:0% +to solar we are trying to look into + + + align:start position:0% +to solar we are trying to look into +other areas like thermal energy and also + + align:start position:0% +other areas like thermal energy and also + + + align:start position:0% +other areas like thermal energy and also +ACH the ocean thermal energy event into + + align:start position:0% +ACH the ocean thermal energy event into + + + align:start position:0% +ACH the ocean thermal energy event into +new new energies as well because + + align:start position:0% +new new energies as well because + + + align:start position:0% +new new energies as well because +initially the Green Technology + + align:start position:0% +initially the Green Technology + + + align:start position:0% +initially the Green Technology +concentration was only by the federal + + align:start position:0% +concentration was only by the federal + + + align:start position:0% +concentration was only by the federal +government uh we didn't incorporate with + + align:start position:0% +government uh we didn't incorporate with + + + align:start position:0% +government uh we didn't incorporate with +the state governments as you can see the + + align:start position:0% +the state governments as you can see the + + + align:start position:0% +the state governments as you can see the +Green Technology Council it's a federal + + align:start position:0% +Green Technology Council it's a federal + + + align:start position:0% +Green Technology Council it's a federal +Council but this year thinking starting + + align:start position:0% +Council but this year thinking starting + + + align:start position:0% +Council but this year thinking starting +from this year we have already + + align:start position:0% +from this year we have already + + + align:start position:0% +from this year we have already +encouraged all the state governments to + + align:start position:0% +encouraged all the state governments to + + + align:start position:0% +encouraged all the state governments to +have their own uh Green Technology + + align:start position:0% +have their own uh Green Technology + + + align:start position:0% +have their own uh Green Technology +Council in state level so once the state + + align:start position:0% +Council in state level so once the state + + + align:start position:0% +Council in state level so once the state +level has their own Green Technology + + align:start position:0% +level has their own Green Technology + + + align:start position:0% +level has their own Green Technology +Council so this kind of information can + + align:start position:0% +Council so this kind of information can + + + align:start position:0% +Council so this kind of information can +be discussed more in in the particular + + align:start position:0% +be discussed more in in the particular + + + align:start position:0% +be discussed more in in the particular +States so then you can see now I I I do + + align:start position:0% +States so then you can see now I I I do + + + align:start position:0% +States so then you can see now I I I do +agree with you the awareness is is + + align:start position:0% +agree with you the awareness is is + + + align:start position:0% +agree with you the awareness is is +pretty much + + align:start position:0% +pretty much + + + align:start position:0% +pretty much +low to improve the we implementation + + align:start position:0% +low to improve the we implementation + + + align:start position:0% +low to improve the we implementation +there's urgent need to have evaluation + + align:start position:0% +there's urgent need to have evaluation + + + align:start position:0% +there's urgent need to have evaluation +of the policy until now there has no + + align:start position:0% +of the policy until now there has no + + + align:start position:0% +of the policy until now there has no +assessment of the Green Technology + + align:start position:0% +assessment of the Green Technology + + + align:start position:0% +assessment of the Green Technology +policy implementation theyve been doing + + align:start position:0% +policy implementation theyve been doing + + + align:start position:0% +policy implementation theyve been doing +so much they've been giving investment I + + align:start position:0% +so much they've been giving investment I + + + align:start position:0% +so much they've been giving investment I +mean uh creating scenario for the + + align:start position:0% +mean uh creating scenario for the + + + align:start position:0% +mean uh creating scenario for the +investment for the Green Technology + + align:start position:0% +investment for the Green Technology + + + align:start position:0% +investment for the Green Technology +players but then as I can tell you that + + align:start position:0% +players but then as I can tell you that + + + align:start position:0% +players but then as I can tell you that +we are not very sure how much benefit + + align:start position:0% +we are not very sure how much benefit + + + align:start position:0% +we are not very sure how much benefit +incur by these people so and how much + + align:start position:0% +incur by these people so and how much + + + align:start position:0% +incur by these people so and how much +green technology has contributed to the + + align:start position:0% +green technology has contributed to the + + + align:start position:0% +green technology has contributed to the +policy itself adopting Green Technology + + align:start position:0% +policy itself adopting Green Technology + + + align:start position:0% +policy itself adopting Green Technology +will not be easy for developing + + align:start position:0% +will not be easy for developing + + + align:start position:0% +will not be easy for developing +countries the most important reason is + + align:start position:0% +countries the most important reason is + + + align:start position:0% +countries the most important reason is +that green technology is a comparatively + + align:start position:0% +that green technology is a comparatively + + + align:start position:0% +that green technology is a comparatively +expensive approach even in developed + + align:start position:0% +expensive approach even in developed + + + align:start position:0% +expensive approach even in developed +countries we still can see that the + + align:start position:0% +countries we still can see that the + + + align:start position:0% +countries we still can see that the +arguments about if Government should + + align:start position:0% +arguments about if Government should + + + align:start position:0% +arguments about if Government should +invest it in Green + + align:start position:0% +invest it in Green + + + align:start position:0% +invest it in Green +Technology but it is clear here from The + + align:start position:0% +Technology but it is clear here from The + + + align:start position:0% +Technology but it is clear here from The +Experience from Malaysia the government + + align:start position:0% +Experience from Malaysia the government + + + align:start position:0% +Experience from Malaysia the government +incentives are still very important to + + align:start position:0% +incentives are still very important to + + + align:start position:0% +incentives are still very important to +encourage Green Technology people say + + align:start position:0% +encourage Green Technology people say + + + align:start position:0% +encourage Green Technology people say +that only developing countries I mean uh + + align:start position:0% +that only developing countries I mean uh + + + align:start position:0% +that only developing countries I mean uh +concentrate too much on subsidies and + + align:start position:0% +concentrate too much on subsidies and + + + align:start position:0% +concentrate too much on subsidies and +incentives but actually it's it's a + + align:start position:0% +incentives but actually it's it's a + + + align:start position:0% +incentives but actually it's it's a +worldwide scenario last mon I went to + + align:start position:0% +worldwide scenario last mon I went to + + + align:start position:0% +worldwide scenario last mon I went to +Holland Netherlands as you can see + + align:start position:0% +Holland Netherlands as you can see + + + align:start position:0% +Holland Netherlands as you can see +Netherland is a very developed country + + align:start position:0% +Netherland is a very developed country + + + align:start position:0% +Netherland is a very developed country +and they really pay much attention to + + align:start position:0% +and they really pay much attention to + + + align:start position:0% +and they really pay much attention to +the environment they very environment + + align:start position:0% +the environment they very environment + + + align:start position:0% +the environment they very environment +friendly people but they have when it + + align:start position:0% +friendly people but they have when it + + + align:start position:0% +friendly people but they have when it +comes to transport industry the + + align:start position:0% +comes to transport industry the + + + align:start position:0% +comes to transport industry the +government in 2013 they came up with + + align:start position:0% +government in 2013 they came up with + + + align:start position:0% +government in 2013 they came up with +this incentive for uh green I mean + + align:start position:0% +this incentive for uh green I mean + + + align:start position:0% +this incentive for uh green I mean +electric vehicles and also plug-in + + align:start position:0% +electric vehicles and also plug-in + + + align:start position:0% +electric vehicles and also plug-in +electric vehicles so when the incentive + + align:start position:0% +electric vehicles so when the incentive + + + align:start position:0% +electric vehicles so when the incentive +was introduced in 2013 the sales of eeve + + align:start position:0% +was introduced in 2013 the sales of eeve + + + align:start position:0% +was introduced in 2013 the sales of eeve +rocketed and the highest sale goes went + + align:start position:0% +rocketed and the highest sale goes went + + + align:start position:0% +rocketed and the highest sale goes went +to uh Mitsubishi Outlander it's known as + + align:start position:0% +to uh Mitsubishi Outlander it's known as + + + align:start position:0% +to uh Mitsubishi Outlander it's known as +PW it's actually a plug-in hybrid + + align:start position:0% +PW it's actually a plug-in hybrid + + + align:start position:0% +PW it's actually a plug-in hybrid +electric vehicle but when the incentive + + align:start position:0% +electric vehicle but when the incentive + + + align:start position:0% +electric vehicle but when the incentive +ended by 31st December 2013 sale of + + align:start position:0% +ended by 31st December 2013 sale of + + + align:start position:0% +ended by 31st December 2013 sale of +electric vehicles in uh Netherlands + + align:start position:0% +electric vehicles in uh Netherlands + + + align:start position:0% +electric vehicles in uh Netherlands +dropped tremendously in + + align:start position:0% +dropped tremendously in + + + align:start position:0% +dropped tremendously in +2014 so as you can see like the + + align:start position:0% +2014 so as you can see like the + + + align:start position:0% +2014 so as you can see like the +lifestyle of people I mean the consumers + + align:start position:0% +lifestyle of people I mean the consumers + + + align:start position:0% +lifestyle of people I mean the consumers +are very much related to incentives and + + align:start position:0% +are very much related to incentives and + + + align:start position:0% +are very much related to incentives and +subsidies secondly for developing + + align:start position:0% +subsidies secondly for developing + + + align:start position:0% +subsidies secondly for developing +countries having consensus will be + + align:start position:0% +countries having consensus will be + + + align:start position:0% +countries having consensus will be +equally critical for launching Green + + align:start position:0% +equally critical for launching Green + + + align:start position:0% +equally critical for launching Green +Technology actions across every area + + align:start position:0% +Technology actions across every area + + + align:start position:0% +Technology actions across every area +from construction to transportation to + + align:start position:0% +from construction to transportation to + + + align:start position:0% +from construction to transportation to +Industry Malaysia has developed + + align:start position:0% +Industry Malaysia has developed + + + align:start position:0% +Industry Malaysia has developed +incentive + + align:start position:0% +incentive + + + align:start position:0% +incentive +policies but local government needs to + + align:start position:0% +policies but local government needs to + + + align:start position:0% +policies but local government needs to +be involved for the knowledge to be + + align:start position:0% +be involved for the knowledge to be + + + align:start position:0% +be involved for the knowledge to be +diffused across the + + align:start position:0% +diffused across the + + + align:start position:0% +diffused across the +country this is also an important law + + align:start position:0% +country this is also an important law + + + align:start position:0% +country this is also an important law +for other non-government institutions + + align:start position:0% +for other non-government institutions + + + align:start position:0% +for other non-government institutions +such as industrial + + align:start position:0% +such as industrial + + + align:start position:0% +such as industrial +associations so where the funding ofme + + align:start position:0% +associations so where the funding ofme + + + align:start position:0% +associations so where the funding ofme +come from the funding of no we have no + + align:start position:0% +come from the funding of no we have no + + + align:start position:0% +come from the funding of no we have no +funding yeah we totally do not have + + align:start position:0% +funding yeah we totally do not have + + + align:start position:0% +funding yeah we totally do not have +funing because we should be self-funded + + align:start position:0% +funing because we should be self-funded + + + align:start position:0% +funing because we should be self-funded +I think self funded so sometime you know + + align:start position:0% +I think self funded so sometime you know + + + align:start position:0% +I think self funded so sometime you know +when the we talk about the funding for + + align:start position:0% +when the we talk about the funding for + + + align:start position:0% +when the we talk about the funding for +the R&D R&D is a long-term investment + + align:start position:0% +the R&D R&D is a long-term investment + + + align:start position:0% +the R&D R&D is a long-term investment +you know at the beginning stage you may + + align:start position:0% +you know at the beginning stage you may + + + align:start position:0% +you know at the beginning stage you may +not see any benefit at all so but you + + align:start position:0% +not see any benefit at all so but you + + + align:start position:0% +not see any benefit at all so but you +have to come up with a lot a lot of + + align:start position:0% +have to come up with a lot a lot of + + + align:start position:0% +have to come up with a lot a lot of +resources for the green product or green + + align:start position:0% +resources for the green product or green + + + align:start position:0% +resources for the green product or green +Industries or even + + align:start position:0% +Industries or even + + + align:start position:0% +Industries or even +the + + align:start position:0% + + + + align:start position:0% + +effici I think we still have to the + + align:start position:0% +effici I think we still have to the + + + align:start position:0% +effici I think we still have to the +government still have to take the Le you + + align:start position:0% +government still have to take the Le you + + + align:start position:0% +government still have to take the Le you +know uh whether with the University or + + align:start position:0% +know uh whether with the University or + + + align:start position:0% +know uh whether with the University or +whether be the industry I think the + + align:start position:0% +whether be the industry I think the + + + align:start position:0% +whether be the industry I think the +government should take the Le + + align:start position:0% +government should take the Le + + + align:start position:0% +government should take the Le +um I do not have doubt that in terms of + + align:start position:0% +um I do not have doubt that in terms of + + + align:start position:0% +um I do not have doubt that in terms of +the green wi Green Technology green + + align:start position:0% +the green wi Green Technology green + + + align:start position:0% +the green wi Green Technology green +industry we are still so much Divine in + + align:start position:0% +industry we are still so much Divine in + + + align:start position:0% +industry we are still so much Divine in +some of the country in our region know + + align:start position:0% +some of the country in our region know + + + align:start position:0% +some of the country in our region know +Japan Taiwan or even the China I think + + align:start position:0% +Japan Taiwan or even the China I think + + + align:start position:0% +Japan Taiwan or even the China I think +we are still so much so we hope that the + + align:start position:0% +we are still so much so we hope that the + + + align:start position:0% +we are still so much so we hope that the +government will play their role leading + + align:start position:0% +government will play their role leading + + + align:start position:0% +government will play their role leading +the industry especially the and of + + align:start position:0% +the industry especially the and of + + + align:start position:0% +the industry especially the and of +course if possible also we be very much + + align:start position:0% +course if possible also we be very much + + + align:start position:0% +course if possible also we be very much +happy to work together also blaming some + + align:start position:0% +happy to work together also blaming some + + + align:start position:0% +happy to work together also blaming some +of the Ministries you know certain + + align:start position:0% +of the Ministries you know certain + + + align:start position:0% +of the Ministries you know certain +information that never sendross that's + + align:start position:0% +information that never sendross that's + + + align:start position:0% +information that never sendross that's +why the association is playing a very + + align:start position:0% +why the association is playing a very + + + align:start position:0% +why the association is playing a very +important role on this most of time we + + align:start position:0% +important role on this most of time we + + + align:start position:0% +important role on this most of time we +are trying to link up the government and + + align:start position:0% +are trying to link up the government and + + + align:start position:0% +are trying to link up the government and +to the to the to the industry or to the + + align:start position:0% +to the to the to the industry or to the + + + align:start position:0% +to the to the to the industry or to the +players besides the government support + + align:start position:0% +players besides the government support + + + align:start position:0% +players besides the government support +both Federal and local government and + + align:start position:0% +both Federal and local government and + + + align:start position:0% +both Federal and local government and +cooperation from other associations + + align:start position:0% +cooperation from other associations + + + align:start position:0% +cooperation from other associations +public education and capacity building + + align:start position:0% +public education and capacity building + + + align:start position:0% +public education and capacity building +for the labor force are also important + + align:start position:0% +for the labor force are also important + + + align:start position:0% +for the labor force are also important +no matter how difficult it is people in + + align:start position:0% +no matter how difficult it is people in + + + align:start position:0% +no matter how difficult it is people in +Malaysia have become aware that Behavior + + align:start position:0% +Malaysia have become aware that Behavior + + + align:start position:0% +Malaysia have become aware that Behavior +change is much + + align:start position:0% +change is much + + + align:start position:0% +change is much +important without Behavior change + + align:start position:0% +important without Behavior change + + + align:start position:0% +important without Behavior change +nothing will happen we should not only + + align:start position:0% +nothing will happen we should not only + + + align:start position:0% +nothing will happen we should not only +look at mitigation we have to look at + + align:start position:0% +look at mitigation we have to look at + + + align:start position:0% +look at mitigation we have to look at +adaptation adaptation meaning to say + + align:start position:0% +adaptation adaptation meaning to say + + + align:start position:0% +adaptation adaptation meaning to say +that also we have to how to adapt to + + align:start position:0% +that also we have to how to adapt to + + + align:start position:0% +that also we have to how to adapt to +this climate change so mitigation can be + + align:start position:0% +this climate change so mitigation can be + + + align:start position:0% +this climate change so mitigation can be +expensive adaptation should come in + + align:start position:0% +expensive adaptation should come in + + + align:start position:0% +expensive adaptation should come in +together and I think the most + + align:start position:0% +together and I think the most + + + align:start position:0% +together and I think the most +challenging part is the Mind chain the + + align:start position:0% +challenging part is the Mind chain the + + + align:start position:0% +challenging part is the Mind chain the +mindset how do you how do you uh promote + + align:start position:0% +mindset how do you how do you uh promote + + + align:start position:0% +mindset how do you how do you uh promote +uh low carbon Society to the local + + align:start position:0% +uh low carbon Society to the local + + + align:start position:0% +uh low carbon Society to the local +Society so that they have mind the Mind + + align:start position:0% +Society so that they have mind the Mind + + + align:start position:0% +Society so that they have mind the Mind +change their mindset changing from very + + align:start position:0% +change their mindset changing from very + + + align:start position:0% +change their mindset changing from very +high consumption to a low consumption + + align:start position:0% +high consumption to a low consumption + + + align:start position:0% +high consumption to a low consumption +Society so by doing that they could cut + + align:start position:0% +Society so by doing that they could cut + + + align:start position:0% +Society so by doing that they could cut +down their waste they could cut down + + align:start position:0% +down their waste they could cut down + + + align:start position:0% +down their waste they could cut down +their consumption and they could + + align:start position:0% +their consumption and they could + + + align:start position:0% +their consumption and they could +actually improve their qual quality of + + align:start position:0% +actually improve their qual quality of + + + align:start position:0% +actually improve their qual quality of +life even without uh having a very high + + align:start position:0% +life even without uh having a very high + + + align:start position:0% +life even without uh having a very high +consumption so I think uh mindset change + + align:start position:0% +consumption so I think uh mindset change + + + align:start position:0% +consumption so I think uh mindset change +is very important that's why in our + + align:start position:0% +is very important that's why in our + + + align:start position:0% +is very important that's why in our +campaign we we started we call it low + + align:start position:0% +campaign we we started we call it low + + + align:start position:0% +campaign we we started we call it low +carbon Society we don't call low carbon + + align:start position:0% +carbon Society we don't call low carbon + + + align:start position:0% +carbon Society we don't call low carbon +City in developing countries the + + align:start position:0% +City in developing countries the + + + align:start position:0% +City in developing countries the +government and the citizens are eagly + + align:start position:0% +government and the citizens are eagly + + + align:start position:0% +government and the citizens are eagly +looking for ways to grow economically + + align:start position:0% +looking for ways to grow economically + + + align:start position:0% +looking for ways to grow economically +but at the same time protect environment + + align:start position:0% +but at the same time protect environment + + + align:start position:0% +but at the same time protect environment +and mitigate Global Climate + + align:start position:0% +and mitigate Global Climate + + + align:start position:0% +and mitigate Global Climate +challenges critics of Green Technology + + align:start position:0% +challenges critics of Green Technology + + + align:start position:0% +challenges critics of Green Technology +is that it's a very expensive investment + + align:start position:0% +is that it's a very expensive investment + + + align:start position:0% +is that it's a very expensive investment +for developing countries and that is not + + align:start position:0% +for developing countries and that is not + + + align:start position:0% +for developing countries and that is not +easy to get access and adopt because of + + align:start position:0% +easy to get access and adopt because of + + + align:start position:0% +easy to get access and adopt because of +knowledge or barriers from 2009 Malaysia + + align:start position:0% +knowledge or barriers from 2009 Malaysia + + + align:start position:0% +knowledge or barriers from 2009 Malaysia +has taken steps to implement green techn + + align:start position:0% +has taken steps to implement green techn + + + align:start position:0% +has taken steps to implement green techn +know each step has not been easy the + + align:start position:0% +know each step has not been easy the + + + align:start position:0% +know each step has not been easy the +malesia experience with promoting Green + + align:start position:0% +malesia experience with promoting Green + + + align:start position:0% +malesia experience with promoting Green +Technology can provide insights for + + align:start position:0% +Technology can provide insights for + + + align:start position:0% +Technology can provide insights for +other developing and developed countries + + align:start position:0% + + + + align:start position:0% + +for \ No newline at end of file diff --git a/bnYD88uNtwY.txt b/bnYD88uNtwY.txt new file mode 100644 index 0000000000000000000000000000000000000000..ea16c25034a9e49825937aca2a217e26d0b425d8 --- /dev/null +++ b/bnYD88uNtwY.txt @@ -0,0 +1,2667 @@ +align:start position:0% + +so hi girls my name is zanga and I am + + align:start position:0% +so hi girls my name is zanga and I am + + + align:start position:0% +so hi girls my name is zanga and I am +currently at the MIT coch Institute + + align:start position:0% +currently at the MIT coch Institute + + + align:start position:0% +currently at the MIT coch Institute +which is a building just for cancer + + align:start position:0% +which is a building just for cancer + + + align:start position:0% +which is a building just for cancer +research and today I'm going to talk + + align:start position:0% +research and today I'm going to talk + + + align:start position:0% +research and today I'm going to talk +about the biological engineering that we + + align:start position:0% +about the biological engineering that we + + + align:start position:0% +about the biological engineering that we +do in order to find and image uh deeply + + align:start position:0% +do in order to find and image uh deeply + + + align:start position:0% +do in order to find and image uh deeply +embedded and difficult to reach tumors + + align:start position:0% +embedded and difficult to reach tumors + + + align:start position:0% +embedded and difficult to reach tumors +uh So currently in the clinic the number + + align:start position:0% +uh So currently in the clinic the number + + + align:start position:0% +uh So currently in the clinic the number +one therapy method for cancer is oh + + align:start position:0% +one therapy method for cancer is oh + + + align:start position:0% +one therapy method for cancer is oh +thank + + align:start position:0% +thank + + + align:start position:0% +thank +you um for cancer is a surgical + + align:start position:0% +you um for cancer is a surgical + + + align:start position:0% +you um for cancer is a surgical +debulking which is basically removing of + + align:start position:0% +debulking which is basically removing of + + + align:start position:0% +debulking which is basically removing of +the mass uh tumor masses and then + + align:start position:0% +the mass uh tumor masses and then + + + align:start position:0% +the mass uh tumor masses and then +chemotherapy and so it's very important + + align:start position:0% +chemotherapy and so it's very important + + + align:start position:0% +chemotherapy and so it's very important +uh for surgeons to be able to locate + + align:start position:0% +uh for surgeons to be able to locate + + + align:start position:0% +uh for surgeons to be able to locate +precisely um and early on in the stage + + align:start position:0% +precisely um and early on in the stage + + + align:start position:0% +precisely um and early on in the stage +of the tumor uh the masses that they + + align:start position:0% +of the tumor uh the masses that they + + + align:start position:0% +of the tumor uh the masses that they +want to remove uh to be the most to in + + align:start position:0% +want to remove uh to be the most to in + + + align:start position:0% +want to remove uh to be the most to in +order to do the most effective + + align:start position:0% +order to do the most effective + + + align:start position:0% +order to do the most effective +therapy and so cancer cells are + + align:start position:0% +therapy and so cancer cells are + + + align:start position:0% +therapy and so cancer cells are +basically cells that have unusual + + align:start position:0% +basically cells that have unusual + + + align:start position:0% +basically cells that have unusual +dividing ability so they proliferate + + align:start position:0% +dividing ability so they proliferate + + + align:start position:0% +dividing ability so they proliferate +without stop um and they are + + align:start position:0% +without stop um and they are + + + align:start position:0% +without stop um and they are +differentiated from the regular cells + + align:start position:0% +differentiated from the regular cells + + + align:start position:0% +differentiated from the regular cells +around them by certain markers on the + + align:start position:0% +around them by certain markers on the + + + align:start position:0% +around them by certain markers on the +surface of the + + align:start position:0% +surface of the + + + align:start position:0% +surface of the +cell and so what we want to do is use + + align:start position:0% +cell and so what we want to do is use + + + align:start position:0% +cell and so what we want to do is use +these markers on the surface in the cell + + align:start position:0% +these markers on the surface in the cell + + + align:start position:0% +these markers on the surface in the cell +in order to find and then tell the + + align:start position:0% +in order to find and then tell the + + + align:start position:0% +in order to find and then tell the +locate um where the tumors are and tell + + align:start position:0% +locate um where the tumors are and tell + + + align:start position:0% +locate um where the tumors are and tell +the surgeons okay this is the place + + align:start position:0% +the surgeons okay this is the place + + + align:start position:0% +the surgeons okay this is the place +where I should remove uh the biological + + align:start position:0% +where I should remove uh the biological + + + align:start position:0% +where I should remove uh the biological +tissue and you don't want to damage the + + align:start position:0% +tissue and you don't want to damage the + + + align:start position:0% +tissue and you don't want to damage the +healthy tissue around it so you want to + + align:start position:0% +healthy tissue around it so you want to + + + align:start position:0% +healthy tissue around it so you want to +be very precise um and very + + align:start position:0% + + + + align:start position:0% + +um yeah so there are two tools uh that + + align:start position:0% +um yeah so there are two tools uh that + + + align:start position:0% +um yeah so there are two tools uh that +we use in our lab in order to uh find + + align:start position:0% +we use in our lab in order to uh find + + + align:start position:0% +we use in our lab in order to uh find +the tumors in the body uh the first is + + align:start position:0% +the tumors in the body uh the first is + + + align:start position:0% +the tumors in the body uh the first is +the custombuilt imager uh that we're + + align:start position:0% +the custombuilt imager uh that we're + + + align:start position:0% +the custombuilt imager uh that we're +working on with the with collaboration + + align:start position:0% +working on with the with collaboration + + + align:start position:0% +working on with the with collaboration +um at the Lincoln labs and the second is + + align:start position:0% +um at the Lincoln labs and the second is + + + align:start position:0% +um at the Lincoln labs and the second is +the biological probe it's a little + + align:start position:0% +the biological probe it's a little + + + align:start position:0% +the biological probe it's a little +shuttle that we use in order to go ahead + + align:start position:0% +shuttle that we use in order to go ahead + + + align:start position:0% +shuttle that we use in order to go ahead +and find the cells in the body so we can + + align:start position:0% +and find the cells in the body so we can + + + align:start position:0% +and find the cells in the body so we can +both so we can talk about both of them + + align:start position:0% + + + + align:start position:0% + +today so the biological maricle that we + + align:start position:0% +today so the biological maricle that we + + + align:start position:0% +today so the biological maricle that we +use is called the M13 bacteria phage and + + align:start position:0% +use is called the M13 bacteria phage and + + + align:start position:0% +use is called the M13 bacteria phage and +bacteria phage really just means + + align:start position:0% +bacteria phage really just means + + + align:start position:0% +bacteria phage really just means +bacteria eater um so it's a virus so as + + align:start position:0% +bacteria eater um so it's a virus so as + + + align:start position:0% +bacteria eater um so it's a virus so as +with typical viruses it + + align:start position:0% +with typical viruses it + + + align:start position:0% +with typical viruses it +infects bacteria sends its in DNA takes + + align:start position:0% +infects bacteria sends its in DNA takes + + + align:start position:0% +infects bacteria sends its in DNA takes +over the local mechanism of the bacteria + + align:start position:0% +over the local mechanism of the bacteria + + + align:start position:0% +over the local mechanism of the bacteria +and begins to replicate itself um so + + align:start position:0% +and begins to replicate itself um so + + + align:start position:0% +and begins to replicate itself um so +what we can do is hack this system in + + align:start position:0% +what we can do is hack this system in + + + align:start position:0% +what we can do is hack this system in +order to use this molecule for our own + + align:start position:0% +order to use this molecule for our own + + + align:start position:0% +order to use this molecule for our own +benefits it's a very beautiful very + + align:start position:0% +benefits it's a very beautiful very + + + align:start position:0% +benefits it's a very beautiful very +simple sort of molecule um it's just a + + align:start position:0% +simple sort of molecule um it's just a + + + align:start position:0% +simple sort of molecule um it's just a +piece of DNA so a DNA that codes for its + + align:start position:0% +piece of DNA so a DNA that codes for its + + + align:start position:0% +piece of DNA so a DNA that codes for its +D not of information and a bunch of + + align:start position:0% +D not of information and a bunch of + + + align:start position:0% +D not of information and a bunch of +proteins that's wrapped around the + + align:start position:0% +proteins that's wrapped around the + + + align:start position:0% +proteins that's wrapped around the +body and so because we can manipulate + + align:start position:0% +body and so because we can manipulate + + + align:start position:0% +body and so because we can manipulate +the DNA we can change the peptides that + + align:start position:0% +the DNA we can change the peptides that + + + align:start position:0% +the DNA we can change the peptides that +are on the body of the Fage and so we + + align:start position:0% +are on the body of the Fage and so we + + + align:start position:0% +are on the body of the Fage and so we +can change the protein so that they have + + align:start position:0% +can change the protein so that they have + + + align:start position:0% +can change the protein so that they have +specific binding abilities to certain + + align:start position:0% +specific binding abilities to certain + + + align:start position:0% +specific binding abilities to certain +materials or certain lians or certain + + align:start position:0% +materials or certain lians or certain + + + align:start position:0% +materials or certain lians or certain +markers so this is the tumor cell + + align:start position:0% +markers so this is the tumor cell + + + align:start position:0% +markers so this is the tumor cell +markers that I'm talking about um we can + + align:start position:0% +markers that I'm talking about um we can + + + align:start position:0% +markers that I'm talking about um we can +change the protein at the head of the + + align:start position:0% +change the protein at the head of the + + + align:start position:0% +change the protein at the head of the +virus in order to bind specifically to + + align:start position:0% +virus in order to bind specifically to + + + align:start position:0% +virus in order to bind specifically to +the surface of a cancer cell and we can + + align:start position:0% +the surface of a cancer cell and we can + + + align:start position:0% +the surface of a cancer cell and we can +change the proteins on the body of the + + align:start position:0% +change the proteins on the body of the + + + align:start position:0% +change the proteins on the body of the +virus to bind to a specific Imaging + + align:start position:0% +virus to bind to a specific Imaging + + + align:start position:0% +virus to bind to a specific Imaging +agent or therapy agent that we can then + + align:start position:0% +agent or therapy agent that we can then + + + align:start position:0% +agent or therapy agent that we can then +shuttle to the surface of + + align:start position:0% + + + + align:start position:0% + +ourselves so for our system here the + + align:start position:0% +ourselves so for our system here the + + + align:start position:0% +ourselves so for our system here the +Imaging agent that we chose is called a + + align:start position:0% +Imaging agent that we chose is called a + + + align:start position:0% +Imaging agent that we chose is called a +carbon N Tube and so a carbon nanot tube + + align:start position:0% +carbon N Tube and so a carbon nanot tube + + + align:start position:0% +carbon N Tube and so a carbon nanot tube +um is just a piece of graphine that's + + align:start position:0% +um is just a piece of graphine that's + + + align:start position:0% +um is just a piece of graphine that's +been rolled up and what graphine is is + + align:start position:0% +been rolled up and what graphine is is + + + align:start position:0% +been rolled up and what graphine is is +um it's just a single layer of graphite + + align:start position:0% +um it's just a single layer of graphite + + + align:start position:0% +um it's just a single layer of graphite +and graphite is what you find in your + + align:start position:0% +and graphite is what you find in your + + + align:start position:0% +and graphite is what you find in your +pencils in lead and so it has very + + align:start position:0% +pencils in lead and so it has very + + + align:start position:0% +pencils in lead and so it has very +interesting Optical and electrical + + align:start position:0% +interesting Optical and electrical + + + align:start position:0% +interesting Optical and electrical +properties and it's very well studied + + align:start position:0% +properties and it's very well studied + + + align:start position:0% +properties and it's very well studied +but for us what's interesting about it + + align:start position:0% +but for us what's interesting about it + + + align:start position:0% +but for us what's interesting about it +is the wavelength at which it emits + + align:start position:0% +is the wavelength at which it emits + + + align:start position:0% +is the wavelength at which it emits +light um this is in the second window + + align:start position:0% +light um this is in the second window + + + align:start position:0% +light um this is in the second window +near infrared uh wavelength and so it's + + align:start position:0% +near infrared uh wavelength and so it's + + + align:start position:0% +near infrared uh wavelength and so it's +slightly longer than the visible + + align:start position:0% +slightly longer than the visible + + + align:start position:0% +slightly longer than the visible +wavelength + + align:start position:0% +wavelength + + + align:start position:0% +wavelength +and the cool thing about this is it's + + align:start position:0% +and the cool thing about this is it's + + + align:start position:0% +and the cool thing about this is it's +able to penetrate deep uh deeper into + + align:start position:0% +able to penetrate deep uh deeper into + + + align:start position:0% +able to penetrate deep uh deeper into +the biological tissue and you have less + + align:start position:0% +the biological tissue and you have less + + + align:start position:0% +the biological tissue and you have less +scattering and less interference from + + align:start position:0% +scattering and less interference from + + + align:start position:0% +scattering and less interference from +the surrounding + + align:start position:0% + + + + align:start position:0% + +materials so finally this is the design + + align:start position:0% +materials so finally this is the design + + + align:start position:0% +materials so finally this is the design +of our shuttles that we send in to find + + align:start position:0% +of our shuttles that we send in to find + + + align:start position:0% +of our shuttles that we send in to find +tumor cells um we have the M13 bacteria + + align:start position:0% +tumor cells um we have the M13 bacteria + + + align:start position:0% +tumor cells um we have the M13 bacteria +phage which has a particular protein at + + align:start position:0% +phage which has a particular protein at + + + align:start position:0% +phage which has a particular protein at +the head that detects the tumors + + align:start position:0% +the head that detects the tumors + + + align:start position:0% +the head that detects the tumors +and we have on the body the CNT the + + align:start position:0% +and we have on the body the CNT the + + + align:start position:0% +and we have on the body the CNT the +carbon nanit tube um that is going to + + align:start position:0% +carbon nanit tube um that is going to + + + align:start position:0% +carbon nanit tube um that is going to +light up and tell us oh this is where we + + align:start position:0% +light up and tell us oh this is where we + + + align:start position:0% +light up and tell us oh this is where we +should go ahead and remove the + + align:start position:0% + + + + align:start position:0% + +mass so the first model that we have + + align:start position:0% +mass so the first model that we have + + + align:start position:0% +mass so the first model that we have +actually done in our lab is on ovarian + + align:start position:0% +actually done in our lab is on ovarian + + + align:start position:0% +actually done in our lab is on ovarian +tumor and ovarian tumor is one of the + + align:start position:0% +tumor and ovarian tumor is one of the + + + align:start position:0% +tumor and ovarian tumor is one of the +tumor bottles that is very difficult to + + align:start position:0% +tumor bottles that is very difficult to + + + align:start position:0% +tumor bottles that is very difficult to +detect early on um it's unlike you know + + align:start position:0% +detect early on um it's unlike you know + + + align:start position:0% +detect early on um it's unlike you know +things like breast tumor you can't feel + + align:start position:0% +things like breast tumor you can't feel + + + align:start position:0% +things like breast tumor you can't feel +it and when usually when the surgeon or + + align:start position:0% +it and when usually when the surgeon or + + + align:start position:0% +it and when usually when the surgeon or +the doctor diagnoses it's quite late in + + align:start position:0% +the doctor diagnoses it's quite late in + + + align:start position:0% +the doctor diagnoses it's quite late in +the stage of of the tumor so it could + + align:start position:0% +the stage of of the tumor so it could + + + align:start position:0% +the stage of of the tumor so it could +have turned metastatic and metastatic + + align:start position:0% +have turned metastatic and metastatic + + + align:start position:0% +have turned metastatic and metastatic +means that the tumor cells have detached + + align:start position:0% +means that the tumor cells have detached + + + align:start position:0% +means that the tumor cells have detached +from the body and traveled to other + + align:start position:0% +from the body and traveled to other + + + align:start position:0% +from the body and traveled to other +parts of the body and so proliferated + + align:start position:0% +parts of the body and so proliferated + + + align:start position:0% +parts of the body and so proliferated +other tumors throughout the body so this + + align:start position:0% +other tumors throughout the body so this + + + align:start position:0% +other tumors throughout the body so this +is a stage you don't want to + + align:start position:0% +is a stage you don't want to + + + align:start position:0% +is a stage you don't want to +reach so it'll be very cool if you can + + align:start position:0% +reach so it'll be very cool if you can + + + align:start position:0% +reach so it'll be very cool if you can +put our probes into mice with aarian + + align:start position:0% +put our probes into mice with aarian + + + align:start position:0% +put our probes into mice with aarian +tumor light up the tumors give the + + align:start position:0% +tumor light up the tumors give the + + + align:start position:0% +tumor light up the tumors give the +surgeon the image and the surgeon can go + + align:start position:0% +surgeon the image and the surgeon can go + + + align:start position:0% +surgeon the image and the surgeon can go +ahead and move the tumors and the mice + + align:start position:0% +ahead and move the tumors and the mice + + + align:start position:0% +ahead and move the tumors and the mice +will then survive so this is a first + + align:start position:0% +will then survive so this is a first + + + align:start position:0% +will then survive so this is a first +step in putting our system towards + + align:start position:0% +step in putting our system towards + + + align:start position:0% +step in putting our system towards +clinical + + align:start position:0% + + + + align:start position:0% + +application so this is what happens in + + align:start position:0% +application so this is what happens in + + + align:start position:0% +application so this is what happens in +real life um you see here the stomach + + align:start position:0% +real life um you see here the stomach + + + align:start position:0% +real life um you see here the stomach +cavity of the mice and in the bright + + align:start position:0% +cavity of the mice and in the bright + + + align:start position:0% +cavity of the mice and in the bright +orange you see all the tumor masses that + + align:start position:0% +orange you see all the tumor masses that + + + align:start position:0% +orange you see all the tumor masses that +have lit up so we have injected the mice + + align:start position:0% +have lit up so we have injected the mice + + + align:start position:0% +have lit up so we have injected the mice +with trillions of our tiny little + + align:start position:0% +with trillions of our tiny little + + + align:start position:0% +with trillions of our tiny little +molecular shuttles that carry our CNT to + + align:start position:0% +molecular shuttles that carry our CNT to + + + align:start position:0% +molecular shuttles that carry our CNT to +the location of the + + align:start position:0% +the location of the + + + align:start position:0% +the location of the +tumor and using our imager which we have + + align:start position:0% +tumor and using our imager which we have + + + align:start position:0% +tumor and using our imager which we have +um built + + align:start position:0% +um built + + + align:start position:0% +um built +um with help from the Lincoln Labs um + + align:start position:0% +um with help from the Lincoln Labs um + + + align:start position:0% +um with help from the Lincoln Labs um +the surgeon is able to go in and remove + + align:start position:0% +the surgeon is able to go in and remove + + + align:start position:0% +the surgeon is able to go in and remove +all these nodules and the cool thing + + align:start position:0% +all these nodules and the cool thing + + + align:start position:0% +all these nodules and the cool thing +about the nodules here is we're getting + + align:start position:0% +about the nodules here is we're getting + + + align:start position:0% +about the nodules here is we're getting +the ones that are even below a + + align:start position:0% +the ones that are even below a + + + align:start position:0% +the ones that are even below a +millimeter in diameter so usually when a + + align:start position:0% +millimeter in diameter so usually when a + + + align:start position:0% +millimeter in diameter so usually when a +surgeon goes in without any guidance he + + align:start position:0% +surgeon goes in without any guidance he + + + align:start position:0% +surgeon goes in without any guidance he +might miss these because he's just going + + align:start position:0% +might miss these because he's just going + + + align:start position:0% +might miss these because he's just going +by ey but because he has the imager he + + align:start position:0% +by ey but because he has the imager he + + + align:start position:0% +by ey but because he has the imager he +can go ahead and move most of the + + align:start position:0% + + + + align:start position:0% + +tumors so here's an example of what + + align:start position:0% +tumors so here's an example of what + + + align:start position:0% +tumors so here's an example of what +we're doing in real time so during + + align:start position:0% +we're doing in real time so during + + + align:start position:0% +we're doing in real time so during +surgery if the surgeon can directly + + align:start position:0% +surgery if the surgeon can directly + + + align:start position:0% +surgery if the surgeon can directly +refer to the image that he's getting um + + align:start position:0% +refer to the image that he's getting um + + + align:start position:0% +refer to the image that he's getting um +then he can go ahead and Implement our + + align:start position:0% +then he can go ahead and Implement our + + + align:start position:0% +then he can go ahead and Implement our +technology in a very real way so here we + + align:start position:0% +technology in a very real way so here we + + + align:start position:0% +technology in a very real way so here we +see Dr na uh at from MGH he's doing + + align:start position:0% +see Dr na uh at from MGH he's doing + + + align:start position:0% +see Dr na uh at from MGH he's doing +surgery on mice um and you can see on + + align:start position:0% +surgery on mice um and you can see on + + + align:start position:0% +surgery on mice um and you can see on +the screen he can see brightly lit up + + align:start position:0% +the screen he can see brightly lit up + + + align:start position:0% +the screen he can see brightly lit up +this is where the tumors are and this is + + align:start position:0% +this is where the tumors are and this is + + + align:start position:0% +this is where the tumors are and this is +where I should take it them and so + + align:start position:0% +where I should take it them and so + + + align:start position:0% +where I should take it them and so +here's a Serial image of what's + + align:start position:0% +here's a Serial image of what's + + + align:start position:0% +here's a Serial image of what's +happening so here's the probes lighting + + align:start position:0% +happening so here's the probes lighting + + + align:start position:0% +happening so here's the probes lighting +up where the tumors + + align:start position:0% +up where the tumors + + + align:start position:0% +up where the tumors +are this is what happens when the + + align:start position:0% +are this is what happens when the + + + align:start position:0% +are this is what happens when the +surgeon goes in by ey and is like okay + + align:start position:0% +surgeon goes in by ey and is like okay + + + align:start position:0% +surgeon goes in by ey and is like okay +from my experience this is where I + + align:start position:0% +from my experience this is where I + + + align:start position:0% +from my experience this is where I +should take out the tumors and you see + + align:start position:0% +should take out the tumors and you see + + + align:start position:0% +should take out the tumors and you see +that there's quite a bit of mass left um + + align:start position:0% +that there's quite a bit of mass left um + + + align:start position:0% +that there's quite a bit of mass left um +but if we have the + + align:start position:0% +but if we have the + + + align:start position:0% +but if we have the +imager then we have a much cleaner image + + align:start position:0% +imager then we have a much cleaner image + + + align:start position:0% +imager then we have a much cleaner image +at the end of the surgery and so there's + + align:start position:0% +at the end of the surgery and so there's + + + align:start position:0% +at the end of the surgery and so there's +a lot less of a chance that the tumor is + + align:start position:0% +a lot less of a chance that the tumor is + + + align:start position:0% +a lot less of a chance that the tumor is +going to + + align:start position:0% + + + + align:start position:0% + +recur so for me personally there are two + + align:start position:0% +recur so for me personally there are two + + + align:start position:0% +recur so for me personally there are two +things I'm doing in order to expand on + + align:start position:0% +things I'm doing in order to expand on + + + align:start position:0% +things I'm doing in order to expand on +our system that we have already built + + align:start position:0% +our system that we have already built + + + align:start position:0% +our system that we have already built +the first is manipulating the M13 phage + + align:start position:0% +the first is manipulating the M13 phage + + + align:start position:0% +the first is manipulating the M13 phage +to different geometries so I call this + + align:start position:0% +to different geometries so I call this + + + align:start position:0% +to different geometries so I call this +en age Ino just means small in + + align:start position:0% +en age Ino just means small in + + + align:start position:0% +en age Ino just means small in +Portuguese + + align:start position:0% +Portuguese + + + align:start position:0% +Portuguese +um and so based on the aspect ratio + + align:start position:0% +um and so based on the aspect ratio + + + align:start position:0% +um and so based on the aspect ratio +which basically is the diameter versus + + align:start position:0% +which basically is the diameter versus + + + align:start position:0% +which basically is the diameter versus +the length um of our phage they might + + align:start position:0% +the length um of our phage they might + + + align:start position:0% +the length um of our phage they might +have very different traveling abilities + + align:start position:0% +have very different traveling abilities + + + align:start position:0% +have very different traveling abilities +in the bloodstream so because of their + + align:start position:0% +in the bloodstream so because of their + + + align:start position:0% +in the bloodstream so because of their +oblong shape they have and a tendency to + + align:start position:0% +oblong shape they have and a tendency to + + + align:start position:0% +oblong shape they have and a tendency to +stick to the walls and Tumble around but + + align:start position:0% +stick to the walls and Tumble around but + + + align:start position:0% +stick to the walls and Tumble around but +if we can change the shape to an optimal + + align:start position:0% +if we can change the shape to an optimal + + + align:start position:0% +if we can change the shape to an optimal +size then there's a chance that they + + align:start position:0% +size then there's a chance that they + + + align:start position:0% +size then there's a chance that they +will travel uh for a longer period of + + align:start position:0% +will travel uh for a longer period of + + + align:start position:0% +will travel uh for a longer period of +time in the bloodstream and so find the + + align:start position:0% +time in the bloodstream and so find the + + + align:start position:0% +time in the bloodstream and so find the +tumors that are farther from the site of + + align:start position:0% +tumors that are farther from the site of + + + align:start position:0% +tumors that are farther from the site of +injection + + align:start position:0% +injection + + + align:start position:0% +injection +the second thing is we are expanding on + + align:start position:0% +the second thing is we are expanding on + + + align:start position:0% +the second thing is we are expanding on +the library of cancers that we can + + align:start position:0% +the library of cancers that we can + + + align:start position:0% +the library of cancers that we can +attack so so far we've looked at ovarian + + align:start position:0% +attack so so far we've looked at ovarian + + + align:start position:0% +attack so so far we've looked at ovarian +tumor um and now I want to look at brain + + align:start position:0% +tumor um and now I want to look at brain + + + align:start position:0% +tumor um and now I want to look at brain +tumor and the most difficult thing about + + align:start position:0% +tumor and the most difficult thing about + + + align:start position:0% +tumor and the most difficult thing about +brain tumor is the bloodb brain barrier + + align:start position:0% +brain tumor is the bloodb brain barrier + + + align:start position:0% +brain tumor is the bloodb brain barrier +so it's just a layer of cells that + + align:start position:0% +so it's just a layer of cells that + + + align:start position:0% +so it's just a layer of cells that +separate your blood from the matter in + + align:start position:0% +separate your blood from the matter in + + + align:start position:0% +separate your blood from the matter in +your brain um and the molecules that + + align:start position:0% +your brain um and the molecules that + + + align:start position:0% +your brain um and the molecules that +pass through are very specific and very + + align:start position:0% +pass through are very specific and very + + + align:start position:0% +pass through are very specific and very +small so it's very hard to deliver from + + align:start position:0% +small so it's very hard to deliver from + + + align:start position:0% +small so it's very hard to deliver from +your bloodstream um various drugs or + + align:start position:0% +your bloodstream um various drugs or + + + align:start position:0% +your bloodstream um various drugs or +Imaging agents to the actual uh brain + + align:start position:0% +Imaging agents to the actual uh brain + + + align:start position:0% +Imaging agents to the actual uh brain +mass so what we have done here is + + align:start position:0% +mass so what we have done here is + + + align:start position:0% +mass so what we have done here is +actually uh engineer the head peptid so + + align:start position:0% +actually uh engineer the head peptid so + + + align:start position:0% +actually uh engineer the head peptid so +the proteins at the head um of our Fage + + align:start position:0% +the proteins at the head um of our Fage + + + align:start position:0% +the proteins at the head um of our Fage +so that it allows for uh travel across + + align:start position:0% +so that it allows for uh travel across + + + align:start position:0% +so that it allows for uh travel across +the blood brain barrier so we can + + align:start position:0% +the blood brain barrier so we can + + + align:start position:0% +the blood brain barrier so we can +deliver these Imaging um molecules to + + align:start position:0% +deliver these Imaging um molecules to + + + align:start position:0% +deliver these Imaging um molecules to +tumors in the + + align:start position:0% + + + + align:start position:0% + +brain so one thing to remember here is + + align:start position:0% +brain so one thing to remember here is + + + align:start position:0% +brain so one thing to remember here is +that the scale that we're working this + + align:start position:0% +that the scale that we're working this + + + align:start position:0% +that the scale that we're working this +at the scale at which we're working is + + align:start position:0% +at the scale at which we're working is + + + align:start position:0% +at the scale at which we're working is +very very small so if you look at CNT or + + align:start position:0% +very very small so if you look at CNT or + + + align:start position:0% +very very small so if you look at CNT or +the rage really it's about 100 times 100 + + align:start position:0% +the rage really it's about 100 times 100 + + + align:start position:0% +the rage really it's about 100 times 100 +thousand times smaller than a strand of + + align:start position:0% +thousand times smaller than a strand of + + + align:start position:0% +thousand times smaller than a strand of +your hair so there's really really tiny + + align:start position:0% +your hair so there's really really tiny + + + align:start position:0% +your hair so there's really really tiny +things um so when I make these small + + align:start position:0% +things um so when I make these small + + + align:start position:0% +things um so when I make these small +Fage they're even smaller than a regular + + align:start position:0% +Fage they're even smaller than a regular + + + align:start position:0% +Fage they're even smaller than a regular +Fage a regular Fage is about 800 + + align:start position:0% +Fage a regular Fage is about 800 + + + align:start position:0% +Fage a regular Fage is about 800 +nanometers um so here's an example of + + align:start position:0% +nanometers um so here's an example of + + + align:start position:0% +nanometers um so here's an example of +280 nanm Fage 100 nanometer Fage and 50 + + align:start position:0% +280 nanm Fage 100 nanometer Fage and 50 + + + align:start position:0% +280 nanm Fage 100 nanometer Fage and 50 +nimet Fage so when I make them and I + + align:start position:0% +nimet Fage so when I make them and I + + + align:start position:0% +nimet Fage so when I make them and I +want to look at them it's really hard + + align:start position:0% +want to look at them it's really hard + + + align:start position:0% +want to look at them it's really hard +because they're so small and you can't + + align:start position:0% +because they're so small and you can't + + + align:start position:0% +because they're so small and you can't +just use regular light microscopy uh to + + align:start position:0% +just use regular light microscopy uh to + + + align:start position:0% +just use regular light microscopy uh to +detect them um so another interesting + + align:start position:0% +detect them um so another interesting + + + align:start position:0% +detect them um so another interesting +thing that I do is use Atomic Force + + align:start position:0% +thing that I do is use Atomic Force + + + align:start position:0% +thing that I do is use Atomic Force +microscopy I don't know if you've heard + + align:start position:0% +microscopy I don't know if you've heard + + + align:start position:0% +microscopy I don't know if you've heard +of it but what it is is basically you + + align:start position:0% +of it but what it is is basically you + + + align:start position:0% +of it but what it is is basically you +take a sample and you have this very + + align:start position:0% +take a sample and you have this very + + + align:start position:0% +take a sample and you have this very +very tiny needle that scans across the + + align:start position:0% +very tiny needle that scans across the + + + align:start position:0% +very tiny needle that scans across the +surface and so you're getting a topology + + align:start position:0% +surface and so you're getting a topology + + + align:start position:0% +surface and so you're getting a topology +of the surface and from that scanning + + align:start position:0% +of the surface and from that scanning + + + align:start position:0% +of the surface and from that scanning +kind of like reading brail you get a + + align:start position:0% +kind of like reading brail you get a + + + align:start position:0% +kind of like reading brail you get a +good idea of what the profile of your + + align:start position:0% +good idea of what the profile of your + + + align:start position:0% +good idea of what the profile of your +image is so these are the images that I + + align:start position:0% +image is so these are the images that I + + + align:start position:0% +image is so these are the images that I +get from this sort of needle probing + + align:start position:0% + + + + align:start position:0% + +um for the brain tumor another + + align:start position:0% +um for the brain tumor another + + + align:start position:0% +um for the brain tumor another +interesting Factor not only can we you + + align:start position:0% +interesting Factor not only can we you + + + align:start position:0% +interesting Factor not only can we you +know bring the Fage to the surface of + + align:start position:0% +know bring the Fage to the surface of + + + align:start position:0% +know bring the Fage to the surface of +the tumor so this is tumor here shown in + + align:start position:0% +the tumor so this is tumor here shown in + + + align:start position:0% +the tumor so this is tumor here shown in +green um this is tumor that actually has + + align:start position:0% +green um this is tumor that actually has + + + align:start position:0% +green um this is tumor that actually has +green fluorescent protein so that means + + align:start position:0% +green fluorescent protein so that means + + + align:start position:0% +green fluorescent protein so that means +they glow um and if we send in our Fage + + align:start position:0% +they glow um and if we send in our Fage + + + align:start position:0% +they glow um and if we send in our Fage +we see that oh yeah our Fage goes ahead + + align:start position:0% +we see that oh yeah our Fage goes ahead + + + align:start position:0% +we see that oh yeah our Fage goes ahead +and coats in red the tumor but then the + + align:start position:0% +and coats in red the tumor but then the + + + align:start position:0% +and coats in red the tumor but then the +other thing we notice is that the Fage + + align:start position:0% +other thing we notice is that the Fage + + + align:start position:0% +other thing we notice is that the Fage +is actually internalized into the tumor + + align:start position:0% +is actually internalized into the tumor + + + align:start position:0% +is actually internalized into the tumor +cells so the Fage comes and attaches to + + align:start position:0% +cells so the Fage comes and attaches to + + + align:start position:0% +cells so the Fage comes and attaches to +the surface and then the tumor cells + + align:start position:0% +the surface and then the tumor cells + + + align:start position:0% +the surface and then the tumor cells +eats the Fage um so in the blue here is + + align:start position:0% +eats the Fage um so in the blue here is + + + align:start position:0% +eats the Fage um so in the blue here is +the nucleus of a + + align:start position:0% +the nucleus of a + + + align:start position:0% +the nucleus of a +Fage um and in the red spread around the + + align:start position:0% +Fage um and in the red spread around the + + + align:start position:0% +Fage um and in the red spread around the +nucleus in the GOI region is our Fage so + + align:start position:0% +nucleus in the GOI region is our Fage so + + + align:start position:0% +nucleus in the GOI region is our Fage so +just tells us we can possibly deliver + + align:start position:0% +just tells us we can possibly deliver + + + align:start position:0% +just tells us we can possibly deliver +things to inside the cells of the cancer + + align:start position:0% +things to inside the cells of the cancer + + + align:start position:0% +things to inside the cells of the cancer +um so that means we could send in + + align:start position:0% +um so that means we could send in + + + align:start position:0% +um so that means we could send in +therapies that disrupt the function and + + align:start position:0% +therapies that disrupt the function and + + + align:start position:0% +therapies that disrupt the function and +so in this way kill the tumor cell + + align:start position:0% +so in this way kill the tumor cell + + + align:start position:0% +so in this way kill the tumor cell +and so can we not only detect where they + + align:start position:0% +and so can we not only detect where they + + + align:start position:0% +and so can we not only detect where they +are and see if we can remove them + + align:start position:0% +are and see if we can remove them + + + align:start position:0% +are and see if we can remove them +effectively but we can also locally um + + align:start position:0% +effectively but we can also locally um + + + align:start position:0% +effectively but we can also locally um +cure + + align:start position:0% + + + + align:start position:0% + +them so overall um today we've looked at + + align:start position:0% +them so overall um today we've looked at + + + align:start position:0% +them so overall um today we've looked at +um the very real medical impact that we + + align:start position:0% +um the very real medical impact that we + + + align:start position:0% +um the very real medical impact that we +can do with imaging and the probe that + + align:start position:0% +can do with imaging and the probe that + + + align:start position:0% +can do with imaging and the probe that +we have biologically engineered in our + + align:start position:0% +we have biologically engineered in our + + + align:start position:0% +we have biologically engineered in our +lab and um the two things that I've done + + align:start position:0% +lab and um the two things that I've done + + + align:start position:0% +lab and um the two things that I've done +is you know look at what we can do to + + align:start position:0% +is you know look at what we can do to + + + align:start position:0% +is you know look at what we can do to +change the geometry and what we can do + + align:start position:0% +change the geometry and what we can do + + + align:start position:0% +change the geometry and what we can do +to change the different cancers that we + + align:start position:0% +to change the different cancers that we + + + align:start position:0% +to change the different cancers that we +can + + align:start position:0% + + + + align:start position:0% + +attack and all of this work of course + + align:start position:0% +attack and all of this work of course + + + align:start position:0% +attack and all of this work of course +isn't possible without the collaboration + + align:start position:0% +isn't possible without the collaboration + + + align:start position:0% +isn't possible without the collaboration +that happens between the colleagues I + + align:start position:0% +that happens between the colleagues I + + + align:start position:0% +that happens between the colleagues I +have at the MIT cook Institute as well + + align:start position:0% +have at the MIT cook Institute as well + + + align:start position:0% +have at the MIT cook Institute as well +as the um scientists we have at the + + align:start position:0% +as the um scientists we have at the + + + align:start position:0% +as the um scientists we have at the +Lincoln labs and so that's another + + align:start position:0% +Lincoln labs and so that's another + + + align:start position:0% +Lincoln labs and so that's another +really cool thing about this project + + align:start position:0% +really cool thing about this project + + + align:start position:0% +really cool thing about this project +it's it's so very Broad and so it brings + + align:start position:0% +it's it's so very Broad and so it brings + + + align:start position:0% +it's it's so very Broad and so it brings +in so many different techniques and + + align:start position:0% +in so many different techniques and + + + align:start position:0% +in so many different techniques and +brings in so many different people and + + align:start position:0% +brings in so many different people and + + + align:start position:0% +brings in so many different people and +so I really want to thank them um and + + align:start position:0% +so I really want to thank them um and + + + align:start position:0% +so I really want to thank them um and +another aspect of this work that I + + align:start position:0% +another aspect of this work that I + + + align:start position:0% +another aspect of this work that I +really find meaningful is that it's F I + + align:start position:0% +really find meaningful is that it's F I + + + align:start position:0% +really find meaningful is that it's F I +am personally funded by families that + + align:start position:0% +am personally funded by families that + + + align:start position:0% +am personally funded by families that +are affected by these types of tumors um + + align:start position:0% +are affected by these types of tumors um + + + align:start position:0% +are affected by these types of tumors um +these types of diseases and so I really + + align:start position:0% +these types of diseases and so I really + + + align:start position:0% +these types of diseases and so I really +want to thank + + align:start position:0% +want to thank + + + align:start position:0% +want to thank +the the goodwi crack hour staller and + + align:start position:0% +the the goodwi crack hour staller and + + + align:start position:0% +the the goodwi crack hour staller and +salmon um families um who have been + + align:start position:0% +salmon um families um who have been + + + align:start position:0% +salmon um families um who have been +really generous with their funding uh + + align:start position:0% +really generous with their funding uh + + + align:start position:0% +really generous with their funding uh +for this + + align:start position:0% + + + + align:start position:0% + +project and yeah finally I want to say + + align:start position:0% +project and yeah finally I want to say + + + align:start position:0% +project and yeah finally I want to say +that for me the M13 is kind of a + + align:start position:0% +that for me the M13 is kind of a + + + align:start position:0% +that for me the M13 is kind of a +building block we're here all as girls + + align:start position:0% +building block we're here all as girls + + + align:start position:0% +building block we're here all as girls +who build and so for me for my building + + align:start position:0% +who build and so for me for my building + + + align:start position:0% +who build and so for me for my building +project is M13 um and I hope that you + + align:start position:0% +project is M13 um and I hope that you + + + align:start position:0% +project is M13 um and I hope that you +guys um are able to understand from this + + align:start position:0% +guys um are able to understand from this + + + align:start position:0% +guys um are able to understand from this +that as an engineer for me it's really + + align:start position:0% +that as an engineer for me it's really + + + align:start position:0% +that as an engineer for me it's really +just about finding creative ways to use + + align:start position:0% +just about finding creative ways to use + + + align:start position:0% +just about finding creative ways to use +my building blocks to make a difference + + align:start position:0% +my building blocks to make a difference + + + align:start position:0% +my building blocks to make a difference +to address the problems that I think are + + align:start position:0% +to address the problems that I think are + + + align:start position:0% +to address the problems that I think are +most important to me um and so yeah + + align:start position:0% +most important to me um and so yeah + + + align:start position:0% +most important to me um and so yeah +thank you very much for listening um + + align:start position:0% +thank you very much for listening um + + + align:start position:0% +thank you very much for listening um +please feel free to ask me any questions + + align:start position:0% +please feel free to ask me any questions + + + align:start position:0% +please feel free to ask me any questions +um I can talk more about myself or I can + + align:start position:0% +um I can talk more about myself or I can + + + align:start position:0% +um I can talk more about myself or I can +talk more about my research + + align:start position:0% +talk more about my research + + + align:start position:0% +talk more about my research +um but yes thank + + align:start position:0% +um but yes thank + + + align:start position:0% +um but yes thank +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +you any questions + + align:start position:0% +you any questions + + + align:start position:0% +you any questions +for yes well I you're using specific + + align:start position:0% +for yes well I you're using specific + + + align:start position:0% +for yes well I you're using specific +examples for the cancer but can these + + align:start position:0% +examples for the cancer but can these + + + align:start position:0% +examples for the cancer but can these +detect any type of cancer or is it just + + align:start position:0% +detect any type of cancer or is it just + + + align:start position:0% +detect any type of cancer or is it just +specific to a couple types it can detect + + align:start position:0% +specific to a couple types it can detect + + + align:start position:0% +specific to a couple types it can detect +any type of cancer as long as you have a + + align:start position:0% +any type of cancer as long as you have a + + + align:start position:0% +any type of cancer as long as you have a +specific uh differentiating marker on + + align:start position:0% +specific uh differentiating marker on + + + align:start position:0% +specific uh differentiating marker on +the cancer that you know of yeah so um + + align:start position:0% +the cancer that you know of yeah so um + + + align:start position:0% +the cancer that you know of yeah so um +not only is this useful in cancer it's + + align:start position:0% +not only is this useful in cancer it's + + + align:start position:0% +not only is this useful in cancer it's +also useful in detecting any other + + align:start position:0% +also useful in detecting any other + + + align:start position:0% +also useful in detecting any other +material as long as you're able to + + align:start position:0% +material as long as you're able to + + + align:start position:0% +material as long as you're able to +modify the head so that it is specific + + align:start position:0% +modify the head so that it is specific + + + align:start position:0% +modify the head so that it is specific +to that material or to that um + + align:start position:0% +to that material or to that um + + + align:start position:0% +to that material or to that um +cell then you can do that which makes it + + align:start position:0% +cell then you can do that which makes it + + + align:start position:0% +cell then you can do that which makes it +a very elegant very cool molecule which + + align:start position:0% +a very elegant very cool molecule which + + + align:start position:0% +a very elegant very cool molecule which +is why I think it's you know something I + + align:start position:0% +is why I think it's you know something I + + + align:start position:0% +is why I think it's you know something I +should be + + align:start position:0% + + + + align:start position:0% + +using all right thank you thank + + align:start position:0% +using all right thank you thank + + + align:start position:0% +using all right thank you thank +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +[Applause] + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/d5pnfFvggYk.txt b/d5pnfFvggYk.txt new file mode 100644 index 0000000000000000000000000000000000000000..096904824563871df9a6a5de43b1fce6a03578ac --- /dev/null +++ b/d5pnfFvggYk.txt @@ -0,0 +1,255 @@ +Mathematically speaking, the +Chebyshev inequality is just a + +simple application of the +Markov inequality. + +However, it contains a somewhat +different message. + +Consider a random variable +that has a + +certain mean and variance. + +What the Chebyshev inequality +says is that if the variance + +is small, then the random +variable is unlikely to fall + +too far off from the mean. + +If the variance is small, we +have little randomness. + +And so X cannot be too +far from the mean. + +In more precise terms, we have +the following inequality. + +The probability that the +distance from the mean is + +larger than or equal to a +certain number is, at most, + +the variance divided by the +square of that number. + +So if the variance is small, the +probability of falling far + +from the mean is also +going to be small. + +And if the number c is large, so +that we're talking about a + +large distance from the mean, +then the probability of this + +event happening falls +off at a rate at + +least 1 over c squared. + +By the way, I should add here +that c is assumed to be a + +positive number. + +If c was negative, then the +probability that we're looking + +at would be equal to 1 anyway. + +And there isn't any point in +trying obtain a bound for it. + +To prove the Chebyshev +inequality, we will apply the + +Markov equality as follows. + +The probability of interest is +the same as the probability + +that the square of this quantity +is larger than or + +equal to the square of c. + +But now, here we have a +non-negative random variable. + +And we can apply the Markov +inequality with X replaced by + +this random variable and with +a replaced by c squared. + +So this gives us the expected +value of the random variable + +of interest divided +by c squared. + +But we recognize that the + +numerator is just the variance. + +And this is the Chebyshev +inequality that we claimed. + +As an application of the +Chebyshev inequality, let us + +look at the probability of this +event that the distance + +from the mean is at least k +standard deviations, where k + +is some positive number. + +Using the Chebyshev inequality +with c replaced by k times + +sigma, we obtain sigma squared +over c squared, which in our + +case is k squared times +sigma squared, + +which is 1 over k squared. + +So what this is saying is that +if you take, for example, k + +equal to 3, the probability that +you fall three standard + +deviations away from the mean +or more, that probability is + +going to be less than or +equal to 1 over 9. + +And this is true no matter +what kind of + +distribution you have. + +Let us now revisit our earlier +example, where X is an + +exponential random variable. + +And we're interested in the +probability that the random + +variable takes a value larger +than or equal to a. + +The Markov inequality gave +us a bound of 1 over a. + +And as we recall, the exact +answer to this probability was + +e to the minus a. + +Let us see what we can get +using the Chebyshev + +inequality. + +Now, our random variable +has a mean of 1. + +Let us assume that a is bigger +than 1, so that we're + +considering an event that we +fall far away from the mean by + +a distance of at least +a minus 1. + +That is we write the probability +that X is larger + +than or equal to a as the +probability that the distance + +of X from the mean is larger +than or equal to a minus 1. + +And now, this event is smaller +than the event that the + +absolute value of X minus 1 +is larger than a minus 1. + +This is because if this event is +true, then that event will + +also be true. + +And now, we can apply the +Chebyshev inequality. + +Here we have the distance +of X from the mean. + +So the Chebyshev inequality +applied to the random variable + +X will have up here +the variance of X, + +which is equal to 1. + +And in the denominator, we will +have a minus 1 squared. + +Notice that if a is a large +number, this quantity here + +behaves like 1 over a squared, +which falls off much faster + +than 1 over a. + +So at least for large a's, the +Chebyshev bound is going to + +give us a smaller bound and, +therefore, more informative + +than what we obtained from +the Markov inequality. + +In most cases, the Chebyshev +inequality is, indeed, + +stronger and more informative +than the Markov inequality. + +And one of the reasons is that +it exploits more information + +about the distribution of the +random variable X. That is it + +uses knowledge, not just +about the mean + +of the random variable. + +But it also uses some +information about the variance + +of the random variable. \ No newline at end of file diff --git a/eeauylMvOvA.txt b/eeauylMvOvA.txt new file mode 100644 index 0000000000000000000000000000000000000000..316a82f8771dbb1c514b45afacaeb9ced51b0bce --- /dev/null +++ b/eeauylMvOvA.txt @@ -0,0 +1,2789 @@ +The following content is +provided under a Creative + +Commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high-quality educational +resources for free. + +To make a donation or view +additional materials from + +hundreds of MIT courses, visit +MIT OpenCourseWare at + +ocw.mit.edu. + +PROFESSOR: Our topics part of +the course by revisiting + +another important topic that-- + +one of the most important topics +in economics which is + +where does capital come from. + +This is a topic that is +essential in economics. + +It's also really central, the +basis, for what is in finance. + +So a lot of what we'll +do today is really-- + +if you want to learn more about +it you take more in + +economics but also more +courses in Course 15. + +So, basically, we spent a lot of +time this semester talking + +about one input to +the production + +function which is labor. + +We talked about labor supply, +labor demand, monopsony + +models, et cetera. + +We haven't talked much about +the other input into the + +production function +which is capital. + +Now, partly, that's because +that's a more awkward concept. + +It's clear what labor is. + +Labor is the workers working +in the production process. + +Capital's a little bit harder +because capital's sort of + +everything else-- the machine, +the land, the buildings, other + +physical inputs. + +And we know where labor +comes from. + +Labor comes from our working. + +But it's less clear where +capital comes from in some + +aggregate concept. + +So, basically, the key thing is +that all forms of capital + +have a common feature. + +All forms of capital have a +common feature which is what + +capital represents is a +diversion of current + +consumption towards future +production and consumption. + +So capital's about diverting +current consumption towards + +future production +and consumption. + +So the original concept of +capital came from farming + +where the notion was that +farmers every year would take + +some of their grain, and, rather +than eating it, they'd + +put it aside to become seed to +plant for the next year. + +That was their capital. + +And so they diverted their +consumption this year which + +was eating the grain they grew +to produce future consumption + +through planting those +seeds and creating + +consumption for next year. + +So, basically, in a modern +economy the idea is the same. + +And so when we think about +capital, what I want you to + +think about is I want you to +think about, basically, the + +capital as money. + +Think of the capital in the +production function as the + +money that we invest in all +these other things that aren't + +labor-- that we invest in +machines, and we invest in + +buildings, and we +invest in land. + +So we want to think about +capital not as physical + +capital but as financial +capital. + +That's the way to be thinking +about that one aggregate + +letter k is this financial +capital. + +It's the money that's invested +in producing goods, in + +building machines, and +building buildings, + +and stuff like that. + +OK? + +Now, basically, where do +firms get that money? + +So you're a firm. + +You want to build a building +or new machine or + +something like that. + +Where do firms get that money? + +They get that money in +capital markets. + +Capital markets are basically +pools of money that firms draw + +on to invest and +create capital. + +So a capital market-- + +literally think of it as a pool +of money that's out there + +that firms can tap into if they +want to build a building + +or build a machine +or buy some land. + +They tap into capital markets +to make those investments. + +So while capital physically +represents lots of different + +things, financially it +represents one thing which is + +the pool of money that firms tap +into to invest, to divert + +current consumption to +future consumption. + +OK? + +It's the pool of money firms +tap into to invest. That's + +what we mean by capital. + +By capital market we represent +that pool of money. + +So think of capital as financial +capital, and think + +of where you get financial +capital in a capital market as + +being that pool of money that +firms tap into to make + +investments to divert +towards the future. + +Now, where does that supply +of money come from? + +Where does that supply +of money come from? + +Well it comes from households' +decisions on how + +much to save. OK? + +So the pool of money in capital +markets, the pool of + +money that firms draw on to +build capital, comes from + +households' decisions +on how much to save. + +So now we see the tie to labor, +the other input in the + +production function. + +Just as households' decisions on +how hard to work determines + +the labor input into the +production function, + +households' decisions on how +much to save determines the + +capital input into the +production function. + +So just as my decision how much +to work determines how + +much labor is available to +firms, my decision on how much + +to save that's what fills +up this pool. + +OK? + +So this pool of financial +capital is filled up by + +household savings and then drawn +down by firms' demand + +for investment. + +And that's the way a capital +market works. + +So, basically, if we think +about capital market + +equilibrium-- + +if you go to Figure 21-1-- + +we have equilibrium in +capital markets. + +Now this is just like we talked +about-- this is the + +other factor markets. + +Just like we talked about labor +markets and determining + +what determines the wage rate +and the optimum amount of + +labor hired, it's same +with capital markets. + +You have some demand +for capital. + +That comes from firms' demand +for investment. + +Firms want new machines. + +They want new buildings. + +That's downward sloping because, +initially, there's + +very high demand for capital. + +But there's a marginal +diminishing product. + +The more capital I have the +less valuable it is on the + +margin, the less you are +willing to pay for it. + +So there's a downward sloping +demand curve for capital and + +an upward sloping +supply curve. + +And the price, in this market, +is the interest rate. + +What is the interest rate? + +The interest rate is the rate +you have to pay households to + +get them to lend you money. + +So the interest rate, i, is +the rate you have to pay + +households to get them +to lend you money. + +So if that interest rate is +very high, firms will not + +demand much investment because +they'll have to pay a lot of + +money to get the financial +capital to finance that + +investment. + +But households will be delighted +to supply lots of + +savings because they're +getting paid a + +high price for it. + +So, basically, the interest +rate serves as the + +equilibrating price +in this market. + +Just as the wage serves as the +equilibrating price in the + +labor market, the interest +rate serves as the + +equilibrating price in +the capital market. + +As the interest rate rises, +folks want to save more, + +filling more money into +that pool of capital. + +And firms want to borrow less, +taking less money out of that + +pool of capital. + +And when that supply and demand +is equilibrated, at + +point e, is going to be where +the firm's drawing on the pool + +at exactly the rate people are +putting money into the pool. + +And that's going to be +the equilibrium. + +OK, so we want to focus on-- + +for today's lecture and +next lecture as well-- + +is what determines the money +that goes into that pool. + +We know what determines the rate +at which firms want to + +draw out of that pool. + +That's basically going to be +determined by the production + +function and all the stuff +we learned in lectures on + +production theory. + +You can get your optimal +demand for capital. + +It's going to be determined +by isocosts and isoquants. + +And you get some k star. + +But what's going to determine +what goes into that pool? + +That's going to be households' +decisions to save. And + +households' decisions to save, +we say, are determined by a + +process we call intertemporal +choice. + +Added some extra letters there-- +intertemporal choice. + +Intertemporal choice-- + +which is basically, instead +of thinking about someone + +choosing between apples and +bananas, we think of them + +choosing between consumption +today + +and consumption tomorrow. + +So think of different periods +like different goods. + +And I'm choosing between +consumption today and + +consumption tomorrow. + +That's my intertemporal +choice-- + +the rate at which I choose to +trade off consumption in + +different periods. + +So for example, I'll illustrate +how this works. + +Let's say that I'm deciding +whether to just tell MIT, + +"Look, I don't want +to work next year. + +I want to stay home and +take care of my kids. + +You're not going to pay me. + +I'm taking an unpaid leave for +a year." Something professors + +can do with enough advance +warning to their + +chairman and such. + +So I'm going to take an unpaid +leave next year. + +I'm thinking about doing that. + +And now I have to +say, OK, fine. + +Next year I'm going to take this +unpaid leave so I have to + +decide how to allocate my-- +and then I'm going to come + +back and life will be +the same thereafter. + +So it's just about next year I'm +going to take this unpaid + +leave. I have to decide how to +allocate my consumption across + +this year while I'm working and +next year while I'm taking + +an unpaid leave. + +And let's say my salary +is $80,000 a year. + +So one thing I could do is I can +consume all $80,000 this + +year and consume nothing +next year. + +That would not be a very +satisfactory outcome as I die. + +That's obviously not going to +be a satisfactory outcome. + +But what's the alternative? + +MIT's paying me this year, +and they're not + +paying me next year. + +What's the alternative? + +Well, the alternative is I can +save. And by saving, what we + +mean is I can loan some of the +money that I make out to firms + +to invest in their physical +capital in return for which + +they'll give me interest. And +next year I can live on the + +interest I've earned from +making that loan. + +Now, I don't literally go to +Genzyme and Microsoft and + +Apple and say I want to +loan you money and + +negotiate with them. + +That obviously would +be impossible. + +What I do is I implicitly loan +to firms through drawing on + +various aspects of the +capital market. + +So does anyone know, how can I +implicitly loan to a firm? + +Let's say I want to-- + +Yeah? + +AUDIENCE: Banks. + +PROFESSOR: Banks. + +So explain what you mean. + +AUDIENCE: You deposit +money in a savings + +account for the bank. + +The bank pays you some interest +rate so that it can + +use your money to loan to bigger +companies that want to + +take money out of the bank. + +And they, in return, get money +from the other companies by + +the companies paying +some interest on + +what they took out. + +PROFESSOR: Exactly. + +We call banks financial +intermediaries. + +What that means is they +basically are the folks who + +can get a hold of firms +and make those loans. + +So, in other words, I don't +loan directly to Genzyme. + +I loan to the bank-- + +Citizens Bank, my bank, +and Citizens + +Bank loans to Genzyme. + +Citizens Bank pays me an +interest rate on my savings-- + +now close to zero, we'll come +to that-- but basically pays + +me some interest rate. + +Genzyme pays them an interest +rate to borrow money, higher + +than what they're paying +me, and the + +difference is bank profit. + +So, basically, one way I can +loan money is I can put in the + +bank and get paid interest. we +don't think about putting in + +the bank as a loan, but that's +basically what you're doing. + +You're loaning it to the bank. + +And they're paying you interest + +rate, i for that loan. + +What else can you do? + +How else can you-- + +Yeah? + +AUDIENCE: You can +purchase stocks. + +PROFESSOR: You could +purchase stocks. + +So, in other words, what I could +do is I could directly + +go to a public company, and I +could take some of my $80,000 + +and buy stock in that company. + +There I'm essentially directly +loaning to them. + +I'm directly giving +them money. + +Now, it's not a loan that's paid +back like a bank loan. + +It's loan that's paid back +hopefully with my stock + +becoming more valuable +or with a dividend. + +So how can I loan? + +One is I can invest-- + +I could put it in the bank. + +The other is I can buy stock. + +I can put it in the bank, and +the bank pays me interest. I + +could buy stock, and that stock +pays off in two ways. + +One is many companies pay what +we call a dividend, what is + +called the dividend, which is +a quarterly payment that + +companies make to their +shareholders. + +So if I invest in a company +that pays a dividend, then + +I'll be getting a quarterly +check from that company that's + +a portion of my investment. + +The other is what we call a +capital gain which is the + +stock could go up in value. + +So next year, if the stock goes +up, if the stock market + +moves steadily-- it doesn't, +it jumps up and down, we'll + +come to that-- + +but if it went steadily up I +could just sell some of that + +stock next year and +have extra money. + +So that's the other thing I +could do with my $80,000. + +I could loan to a company +by buying their stock. + +How else can I loan +to a company? + +Yeah? + +AUDIENCE: I don't know exactly +what the difference is, but + +couldn't you also invest +your money in a + +mutual fund or something? + +PROFESSOR: A mutual fund-- +that's a good point. + +That would be loaning-- + +a mutual fund is essentially +loaning money to an aggregate + +collection of companies. + +So there are very different +ways I can do stock. + +I can do a mutual fund, I can +buy individual stocks. + +There's lots of different +ways, but those are all + +different ways to buy stock. + +Yeah? + +AUDIENCE: You could buy bonds. + +PROFESSOR: You could +buy bonds. + +You could buy company bonds +which is I literally loan + +directly to the company. + +Stocks aren't really a loan. + +I'm literally buying an +ownership share in the + +company, and they're +paying me back. + +I could buy corporate bonds. + +I could buy corporate bonds, and +the way those work is it's + +literally cutting out +the middleman. + +I don't loan to Citizens Bank, +and they loan to the company. + +I just loan to the company, +and they pay me back. + +That's a corporate bond. + +I can also buy, by the +way, I can also buy + +a government bond. + +You may know the government's +running more than a trillion + +dollar deficit right now. + +Somebody's got to +finance that. + +So you can loan to the +government and get paid back + +by the government. + +OK, let's put the government +aside for a minute. + +Let's focus where we just-- + +we haven't really +had a government + +sector in our models. + +We're where it's just you +and the companies. + +So let's leave the government +channel aside. + +But the other thing I can do +with my money is I can loan it + +through bonds. + +The point is that $80,000-- + +yeah, I'm sorry. + +AUDIENCE: With stocks, if I +were to buy a stock from a + +company, wouldn't it be +primarily and usually through + +the secondary market? + +I wouldn't be giving any +money to the company. + +I'd just be giving money to +the previous stockholder. + +PROFESSOR: That's true. + +It basically depends on whether +the marginal stock + +comes from a new issuance as +stock by the company or + +through stock that's already +floating around + +the secondary market. + +That's a good point. + +So in some sense the-- + +likewise with bonds. + +A lot of bonds are traded +in a secondary market. + +So I'm thinking about a simple +model where basically new + +stock gets issued by the +company, I buy it. + +More technically you're right. + +It's just trading among people, +but that sort of makes + +things complicated. + +Let's put that aside for now. + +So, basically, the point +is is my $80,000-- + +there's lots of things +I can do with it. + +All of them yield +me some rate-- + +the key point is all of them +have the feature that I'm + +diverting today's consumption +for tomorrow's consumption. + +I'm taking some of my money +and, rather than eating it + +this year when I'm working, +I'm loaning it out in some + +way, shape, or form and getting +payback in next year + +when I'm not working. + +And we can summarize. + +Now this is a very complicated +set of mechanisms, not to + +mention the secondary +market issues. + +And this is basically a +semester of 15.401. + +This is basically a semester +of finance theory. + +But basically what we're going +to do is compress this all + +down and say that I get some +interest rate on my money. + +However I do it, let's just say +that somehow I divert my + +money through one of these +mechanisms, and it yields some + +effective interest rate, i. + +And you can know behind that +there's lots of ways I can get + +that interest. But for now just +simplify it down and say + +the main thing is I'm diverting +my consumption now, + +and it's yielding some interest +earnings on that + +diverted consumption, i. + +So what that means is that for +every dollar I divert, I get 1 + +plus i dollars the next year. + +So for every dollar of +consumption I divert, in one + +of these forms, I get 1 plus +i dollars next year. + +So, basically, I could +literally-- + +if I wanted to-- let's say the +interest rate was 10%, just + +for example. + +Now what that means is instead +of consuming $80,000 this year + +and nothing next year, I could +consume nothing this year and + +$88,000 next year. + +Obviously, that's not very +satisfactory either. + +So how do we think about that? + +We think about that in +Figure 21-2 shows-- + +now this is a complicated +diagram we gotta + +use to figure 21-2-- + +this shows the intertemporal +choice model, intertemporal + +substitution we also call it. + +So the deal is that now instead +of the x-axis being + +pizza and the y-axis being +movies or all the other wacky + +things we've done, now the +x-axis is first period + +consumption. + +The y-axis is second +period consumption. + +You might say what's a period? + +Well a period's whatever I want +it to be-- a day, a year, + +10 years, whatever. + +Sometimes I'll say a year. + +Sometimes I'll say a period, +but the point + +is it doesn't matter. + +It's about the trade-off. + +So in my example, c1 is +consumption this year. + +c2's consumption next year. + +And my trade-off is I can +consume $80,000 this year, or, + +given the interest rate, I can +consume $88,000 next year. + +Now the trade-off-- that's +a typo, by the way. + +That should be minus 1.1. + +OK? + +This is a 10% interest rate. + +The key point is the trade-off +is that, basically, I can + +trade off for every dollar I +don't consume this year, I + +consume 1 plus i-- + +1 plus r there, should +be 1 plus i dollars-- + +next year. + +We use r and i interchangeably +for the interest rate, so 1 + +plus i, 1 plus r dollars +next year. + +So, basically, what does the +interest rate represent? + +This is important. + +The wage rate I defined as +the price of leisure. + +Remember what the +wage rate was? + +It was the price of leisure, +that basically by working I + +forgoed the ability to-- + +I'm sorry, by taking leisure +I forgoed the ability to + +earn a wage, w. + +So, literally, that was a price +of sitting around on the + +couch was the wage, w, +I could've earned. + +Likewise, the interest rate is +the price of first period + +consumption. + +By consuming today, I'm forgoing +the fact that I + +could've earned the interest on +that money had I consumed + +it tomorrow or next year. + +So the interest rate is the +price of first period + +consumption, just as the wage +is the price of leisure. + +Yeah? + +AUDIENCE: You said before +that r and i are used + +interchangeably for interest. +Does that play into the cost + +function at all? + +Is the cost for capital going +to be the interest rate? + +PROFESSOR: I'm going +to come to that. + +That's exactly what I'll talk +about next lecture. + +So, basically, this is the key +thing, but the key thing to + +understand intertemporal +choice-- and the other + +important point to understand on +why it's a bit harder than + +labor is there's an extra-- + +well it's not harder. + +It's the same thing. + +Remember, we said we don't model +bads in this course. + +We model goods. + +So we're modeling your choice +of how hard to work. + +We model the trade-off between +consumption and leisure. + +And then we said define labor +as the total amount of hours + +available minus leisure. + +Same thing here. + +We don't model savings. + +That's a bad. + +Now you might not think +[? some of these ?] + +things are good, but +savings really by + +itself is not a good. + +Unless you're Scrooge McDuck-- + +does anyone know who +Scrooge McDuck is? + +Wow, that hurts. + +OK, he was this old cartoon +character when I was a kid who + +used to, like, fill a +swimming pool with + +money and swim in it. + +Basically, unless you're like +that, the savings itself does + +not give you utility. + +We don't have savings entering +utility functions. + +We have consumption entering +utility functions. + +Savings is a bad. + +Savings is the mean by which +you translate consumption + +period one into consumption +period two. + +But from the effect of today +you wish you didn't have to + +save. You just do it because +you want to make + +sure you eat tomorrow. + +So we model the good. + +The good is consumption in +period one, and savings is the + +difference between income and +consumption in period one. + +So we don't model savings. + +We define savings +as y minus c1. + +We model c1, and define +savings as y minus c1. + +You can see that there +in the diagram. + +Now what happens when the +interest rate changes? + +Let's go to Figure 21-3. + +What happens when the interest +rate changes? + +Actually, go to 21-4. + +OK? + +Skip 21-3. + +Got to 21-4. + +What happens when the interest +rate changes? + +So, initially, we're at a point +like a and then the + +interest rate goes +up from r to r2. + +The interest rate goes up. + +Now what does that do? + +Well, graphically, it steepens +the budget constraint. + +What that means is it's raised +the opportunity cost of first + +period consumption. + +First period consumption is now +effectively more expensive + +because I'm forgoing a better +savings rate by eating today. + +The more of my $80,000 I consume +today, the less I get + +to save for tomorrow. + +And that's now a better deal to +save for tomorrow because + +I'm getting a higher interest +rate on that. + +So what does that do? + +Well that has two effects. + +Just like a change in the wage +rate has two effects-- a + +substitution effect and +an income effect. + +The substitution effect, which +we can unambiguously sign, is + +the fact that now first period +consumption's gotten more + +expensive, so we +do less of it. + +Substitution effects are always +price goes up, you do + +less of the activity. + +The substitution effect is first +period consumption's + +gotten more expensive, there'll +be less of it. + +Now here, once again, don't +slip into thinking about + +savings yet. + +You'll really get yourself +in trouble, and + +it's a natural tendency. + +Model consumption that makes +savings a residual. + +So the activity we're modeling +here is first period + +consumption. + +The price of first period +consumption's gone up, so you + +do less of it. + +That's the substitution +effect. + +The income effect is +you're now richer. + +And you might say what do +you mean I'm richer? + +I still have the same +$80,000 in income. + +But any given dollar of savings +yields more income in + +the second period. + +So, overall, you're richer. + +If you take the perspective of +saying I have two periods in + +this model-- first and +second period. + +Any given level of savings +makes me richer + +in the second period. + +That means I'm richer. + +If I'm richer, I consume more of +everything including first + +period consumption. + +So first period consumption +goes up + +from the income effect. + +I find this confusing. + +I don't know if you guys do, but +once again-- run through + +this again. + +I'm richer because for any given +amount of savings I now + +have a total larger sum of +money over both periods. + +When I'm richer I consume +more of everything. + +One of the things that I consume +more of is first + +period consumption. + +So, actually, first period +consumption goes + +up, and I save less. + +It's sort of bizarre. + +Because I'm getting +more return to my + +savings I save less. + +Here is the way I like +to think of the + +intuition to make it easier. + +The way I like to think of the +intuition is imagine that you + +have a goal for saving-- +something I call a target + +savings level. + +Imagine you said, look. + +Imagine you said that I really +want to make sure that I have + +certain level of savings +to live on next year. + +Well if the interest rate goes +up, I can save less to get to + +that target. + +Right? + +If I have a target, c2, and the +interest rate is higher I + +can consume more c1 and still +hit my target of c2. + +So that's the income effect. + +I can effectively consume more +c1 because I'm made richer + +because any given level of +savings allows me to consume + +more the next period. + +Now the target's an extreme +case, but I find it a useful + +intuition for thinking about +what's going on. + +And that's the income effect. + +Now, obviously, as with +anything, this is ambiguous. + +If you go to Figure 21-3 now +here's a case where the income + +effect dominates. + +Well, actually, go +back to 21-4. + +Let's finish this example. + +So here with the substitution +effect dominating, when the + +interest rate goes up I consume +less in period one + +which means I save more. + +And that was prior intuition. + +A higher interest rate +means you save more. + +But we'll work through the +mechanics of how we get there. + +And the reason the mechanics +is important is because of + +Figure 21-3. + +Which as in 21-3, the interest +rate goes up, but I save less. + +The interest rate goes up, but +I consume more in period one + +and therefore save less. + +And that's consistent with +this target notion. + +That basically I'm so-- + +All I care about-- let's say +in the limit if all I care + +about in the limit is exactly +what I consume the second + +period, then, basically, my +period one's consumption will + +definitely go up from a raise in +the interest rate because, + +basically, I'm saying, look, all +I care about is what I get + +in the second period. + +Now I can save less and +get to that target. + +So my consumption first +period goes up. + +The income effect dominates. + +So the bottom line is, just +like with labor supply, we + +can't tell. + +Unlike with goods where it's +rare to see a Giffen good, + +here we honestly don't know +whether a raise in the + +interest rates will raise +savings or lower savings. + +It all depends on the +strength of the + +substitution and income effects. + +Let me actually say one of the +most disturbing things in + +empirical economics is we +actually do have no idea. + +Literally, there's no convincing +study out there + +which even tells us which way +the effect of interest rates + +goes on savings. + +We think probably the +substitution effect dominates, + +but it's been very +hard to find a + +convincing estimate of that. + +So it's a little bit disturbing + +for empirical economics. + +We'll typically assume it +dominates, but don't + +necessarily assume that +in the real world. + +OK, questions about that-- + +intertemporal choice +framework? + +OK, now, with that in mind, +let's now talk about how + +capital markets work. + +How do capital markets work? + +And the key concept for thinking +about capital markets + +is the concept of +present value. + +And the concept of the present +value is simple. + +It's that $1 tomorrow is worth +less than $1 today. + +$1 tomorrow is worth +less than $1 today. + +And why is that? + +It's because if I had the +dollar today, I could've + +invested it in something +productive and had 1 plus i + +dollars tomorrow. + +So if you give me a dollar today +I could have 1 plus i + +dollars tomorrow. + +If you give it to me tomorrow, +I just have $1. + +So by definition, $1 today is +worth more because I have the + +opportunity to save it. + +Whereas a $1 tomorrow +I don't have the + +opportunity to save it. + +It's too late. + +So the key point is you can't +add up dollars that you + +receive in different periods. + +So, in other words, +if I said to you-- + +if this intertemporal choice +graph was back pizzas and + +movies, and I said you have +nine pizza plus movies. + +You have a total of nine. + +You'd be like, what the +hell does that mean? + +It matters if it's nine pizzas +and zero movies or five movies + +and four pizzas? + +I don't know what that means. + +Those are different things. + +You can't add them up. + +You can't just say +I have nine. + +Well consumption over time-- +it's the same thing. + +You can't just add up your +consumption tomorrow and + +consumption today or a dollar +tomorrow and a dollar today. + +They're different things. + +And so you have to account for +the fact that $1 tomorrow is + +worth less than $1 today in +trying to add them up. + +And the way we do that is we +actually do it through the + +concept of present value. + +And the idea of present value +is to translate all future + +dollars into today's dollars. + +Translate all future dollars +into today's dollars + +recognizing the fact they're +less valuable in the future. + +So the concept of present value +is the concept of any + +future payment's value from +the perspective of today. + +And you should know that any +future payment will be worth + +less than a payment today. + +How much less-- that's what +present value tells you. + +How much is a future payment +worth in today's terms? + +So suppose that the interest +rate is 10%. + +Suppose the interest rate +is 10%, and you want to + +have $100 next year. + +So you know next year there's +something you want to buy, and + +you have to decide how much do +I have to save today to have + +$100 in period two. + +How much do I have to +save today to have + +$100 in period two? + +Well if you put in an amount, +PV, into the bank-- + +you put PV into the bank, then +you know next year you're + +going to have-- if you put in +PV in period one, next year + +you're going to have +PV times 1 plus i. + +You're going to have your PV +plus all the interest you + +earned on it, or in our +example, PV times 1.1. + +So what that says is that, +basically, you have to put in + +100 over 1.1 into the +bank today, or + +90.9 dollars, $90.90. + +If you put $90.90 in the bank +today, you will have $100 + +tomorrow or $100 next year-- +whenever the periodicity of + +the interest rate. + +So, basically, more generally, +the present value of any + +stream of payments is equal to +that stream's future value-- + +I'm going to write +it over here. + +It's bigger. + +The present value of any stream +of payments is that + +stream's future value over 1 +plus the interest rate to the + +t, where t is the year in +which you get the money. + +So any future money you get in +year t is worth that amount + +you get over 1 plus the interest +rate to the t. + +So, basically, the point +is you have to weigt. + +Any money you're going to get, +you to weight by how far into + +the future it is, just like +if you're adding up these + +different goods. + +So, essentially, this is kind +of like saying let's add a + +converter machine which can +convert pizza into movies. + +Then I could say well I'll +just take pizza, put it + +through the converter machine, +and that'll tell me how many + +movies I have. That's +what a utility + +function basically does. + +This we're saying the +interest rate is + +the converter function. + +This present value formula is +the converter function by + +which we convert two goods +that are different + +into the same good. + +You convert them through +this formula. + +So, basically, suppose that you +say to me, "Look, loan me + +$30, and I'll pay you back $10 +a year each of the next three + +years." Well I should +say, "Wait a second. + +What's the value of that to me?" +Well the present value of + +those repayments is I'm going +to have $10 in one year, so + +that's $10 over 1 plus i. + +Let's say the interest +rate's 10% again. + +Next year I got $10. + +That's worth 10 over 1 plus 1. + +The year after, you're going +to give me 10 more dollars, + +but that's worth 10 over 1 plus +1 squared because that's + +in two years. + +If I had that money today, I +could've invested it, earned + +10% and then 10% on that. + +And, likewise, the money you +give me in the third year is + +worth 10 over 1.1 cubed. + +If you'd given me that money +today, I could've invested it + +and and earned interest +three times on it. + +So the bottom line is +your repayments + +are only worth $24.87. + +So I've just given you $30 today +in return for a stream + +of payments that's only +worth $24.87 today. + +I've lost money from that loan +because I gave you the money + +today, and you're paying me back +in the future when the + +money's worth less. + +So, basically, the general +formula we have is that the + +present value of any stream of +future payments is that the + +amount of the future payment-- +let's call it f for any fixed + +stream of future payments, $10 +forever or $15 forever-- + +fixed stream of that amount, f, +times 1 over 1 plus i, plus + +1 over 1 plus i squared, plus +da da da da, plus 1 over 1 + +plus i to the t. + +So if you're going to pay me a +fixed amount, f, for t years, + +here what it's worth +to me today. + +You pay me a fixed amount, f, +for t years, it's worth this + +much to me today. + +I'm accounting for how far +off in the future it is. + +Now one important trick we're +going to do now for the rest + +of the semester is we're going +to take the trick of saying + +this is actually-- + +well this is a messy formula. + +It's actually a rather easy +formula to write down if the + +future stream of payments is +infinite, if we have what we + +call a perpetuity. + +If we have what we call +a perpetuity. + +A perpetuity is a future stream +of payments that goes + +on forever or long enough that +we'd consider it forever. + +Fifty years is probably +good enough. + +If you have a perpetuity, +then this formula + +can be reduced to-- + +the present value of any +perpetuity is the amount of + +that perpetuity over +the interest rate. + +It's just taking the infinite +sum of that product. + +They're just taking +the infinite sum. + +Those mathematically inclined +will know this already. + +But it's just taking the +infinite sum here, you can get + +this formula. + +So any perpetuity, if you're +getting a payment forever, the + +value of that payment today-- so +if I said I'll give you $10 + +forever and the interest rate's +going to be 10% then + +you'd say that's worth +$100 to me. + +If I'm going to give you $10 +forever at a 10% interest + +rate, then you'd say well that's +worth $9.90 the next + +year and $8 something the +next year, et cetera. + +And if I add all those up, I get +approximately the amount + +of the payment over +the interest rate. + +So, basically, that is what +determines present value. + +Now we can flip this around and +we could say, OK, well, if + +that's present value what +determines future value? + +Well the future value of getting +a payment today-- + +So that's the present value of +getting payments tomorrow. + +The only other thing is what's +the future value? + +What's the future value of +getting a stream of payments + +starting today? + +So let's say, starting today, +I'm going to get $10. + +I'm going to get it for a +certain number of years. + +What's that going to be worth +at the end of the day given + +that I can save it +along the way. + +So, in other words, if you +give me $10 today-- + +if you give me $10 today, well +then in one year, next year, I + +have $11 because I got to save +it at the interest rate. + +So if you give me $10 today, +next year I'll have $11. + +Now let's say that I +then keep it in the + +bank for another year. + +Well the next year, it's worth +10 times 1 plus i squared, so + +10 times 1.1 squared, 10 +times 1.1 squared, or + +$12.10 and so on. + +So, basically, the point is that +at the end of each year I + +earn the interest on my original +$10, plus I earn the + +interest on the interest I +earned the previous periods. + +So in the long run, at the end +of t years, which of the + +future value, is the amount +invested, f, times 1 + +plus i to the t. + +That's your future value. + +So if you invest a given amount +of money today for t + +years, you end up +with that much. + +If you invest a given amount, +f, today you end + +up with that much-- + +And the key point, the key +insight, is the miracle of + +compounding. + +The miracle of compounding is +the point that you earn + +interest on your interest. And +what this means is the earlier + +you save, the more you'll +have later on. + +So there's an example in the +book which is very important. + +So it's actually thinking +about-- + +let's think for a minute +about retirement. + +You might say this +is sort of crazy. + +Maybe not crazy for an old guy +like me, but you're thinking + +I'm just starting +on my career. + +Why would I think about +retirement? + +Here's why you want +to think about it. + +Let's say, for example, that +you plan to work full time + +from age 22 to age 70. + +You've got a great idea. + +Screw grad school. + +You're going right to work. + +You've got a great idea, +and you know you want + +to retire at 70. + +So you plan to work full time +from age 22 to age 70. + +And let's say that you want to +save money for your retirement + +because you're going +to retire at 70. + +You're going to live forever. + +You're a healthy young person. + +You think you're going to +live forever at 70. + +So you want to have money +around when you retire. + +And let's say that the +interest rate you + +can save at is 7%. + +So you can save money for your +retirement at 7%, and that's + +your choice. + +Now let's consider two different +savings plans. + +Savings plan one is that I'm +going to save $3,000. + +You're going to save $3,000 +right off the bat. + +And for the first 15 years +of your working life-- + +so from 22 to 37-- + +you're going to save $3,000. + +You're going to save $3,000 a +year savings for 15 years, and + +then nothing. + +And then once you're 37 and +you've got to start worrying + +about kids' college and +mortgage, you're not going to + +save anything. + +So from 22 to 37, when you're +living high on the hog, you've + +got no obligations, you're going +to save. Once you're 37, + +you've got a house, you've got +kids, you've got things that + +are expensive, you're not +going to save anymore. + +So then you go to zero. + +Zero savings from age +37 to age 70. + +That's a pretty bold plan. + +You're just going to save 15 +years then zero savings. + +Well what do you get? + +Well after 15 years, if you use +our future value formula, + +if you save $3,000 every year, +you work out that you will + +have $75,387 in the bank. + +So it's more than 45-- is not +just 3,000 times 15 because + +you get the compounding. + +It's not just 3,000 times 15. + +You actually get more than +that because you got the + +compounding along the way. + +Then if you just let it sit +there in the bank-- you don't + +do anything. + +No more active savings. + +You let it sit there. + +Then by the time you retire, +you have that $75,387 times + +1.07 to the 33 because you +let that money sit + +there for 33 years. + +You let that money sit +there for 33 years. + +That works out to be $703,010. + +So by saving for 15 years-- all +you did was save $3,000 + +for 15 years, a fraction +of your career. + +And you retire with $703,000. + +Now we'll contrast that with +an alternative plan. + +My alternative plan is I'm going +to save nothing for the + +first 15 years because I figure, +like, I'm young. + +I'm gonna party. + +I'm going to use +the money now. + +I'll save later. + +I'm nowhere near retirement. + +Then I get to 37. + +I say, wait a second, I'm + +starting to see more mortality. + +I better worry about +retirement. + +Then I start to save, and I save +for the next 33 years. + +So the new plan is zero per year +from age 22 to 37, and + +then $3,000 a year +from 37 to 70. + +So it's a lot more savings. + +You're saving for more than +twice as long, more + +than twice as long. + +What do you end up with? + +You end up with $356,800-- + +half, just slightly more than +half, than what you end up + +with the first plan, even though +you save for twice as + +many years. + +This is like the parents' +lecture why you should save. + +The point is that saving early +lets you ride the wave of + +compounding for many, +many years. + +Savings late does not +let you do that. + +And as a result, you end +up with less money. + +I take my kids to the science +museum, and at the science + +museum they have these +little ramps. + +And you can drop a ball. + +And one is flat then steep, and +one is steep then flat. + +And the one that's steep then +flat always wins because + +there's compounding in +acceleration the same way. + +The point is building up early +and then riding that velocity + +going forward is a lot better +than starting late. + +Questions about that? + +So make sure when you get those +jobs, and they offer + +you-- we'll talk next time about +savings incentives-- and + +they offer you those good 401K +packages, that you take them, + +and don't say I'll worry +about that later. + +Now, one last thing. + +Last thing I want to cover is +that we've ignored, so far, + +the whole concept +of inflation. + +When I've talked about savings, +I've presumed that + +you've saved the money and +it's worth something. + +But who the hell knows +what $703,000 will + +be worth in 48 years? + +What's that even going +to be worth? + +How do we even think +about that? + +Well we have to account for the +fact that stuff's going to + +be more expensive. + +So we have to account for +inflation in doing this. + +And the way we do this is by +recognizing that what we've + +done so far is we've +talked about the + +nominal interest rate. + +By the nominal interest rate, I +meant the interest rate that + +you actually see posted +in the bank. + +But what matters, ultimately +for your well-being, is the + +real interest rate which is +what your money can do in + +terms of actually +buying goods. + +So I should not care about how +much money I have next year. + +I should care about how many +goods I can buy next year. + +The money's just paper. + +What matters is what +I can get with it. + +That's what matters. + +So let's say, for example, +I want to use + +all my money on Skittles. + +That's just what I want +to use my money on. + +So let's say I have $100, +and I want to spend + +that money on Skittles. + +And let's say Skittles +today are $1 a bag. + +And let's say the interest +rate, once again, is 10%. + +And let's say there's +no inflation. + +Inflation equals zero. + +So my choice is I can spend +$100 on Skittles + +today and get 100 bags. + +So I could have 100 +bags today. + +Or I can save it, have +$110 tomorrow and + +get 110 bags of Skittles. + +That's my choice. + +That's my trade-off. + +Now let's say there's +inflation. + +Let's say that prices are rising +at 10% a year, as well. + +So the prices are rising +10% a year, as well. + +What that means is next year +Skittles cost $1.10 a bag. + +So now what's my trade-off? + +That means I could +have 100 bags + +today or 100 bags tomorrow. + +I don't get any more +Skittles tomorrow. + +I get 10 more dollars, +but who cares? + +Everything costs more. + +If everything cost 10% more and +I get a 10% interest rate, + +that interest rate is +effectively zero in terms of + +what I can buy. + +The real interest rate +is the nominal + +interest rate minus inflation. + +What I care about is +what I can buy. + +So I have to take out +of the interest rate + +what happens to prices. + +Because if prices go up, +it offsets what I'm + +earning in the bank. + +And so what I care about is I +care about what the bank posts + +minus what inflation will be. + +So it's even trickier, right? + +Because it's not about what +inflation was, it's what + +inflation will be. + +You'll have to guess what +inflation is going to be. + +And so what we care about is +this real interest rate. + +And that's why the interest rate +that banks pay, a primary + +determinant of it +is inflation. + +Right now, we are in the lowest +inflation period this + +nation's seen since +World War II. + +Core inflation-- + +we don't really get into +inflation in this course-- but + +core inflation, which is +inflation minus some things + +which fluctuate a lot, is +basically zero in the US. + +So, basically, nominal interest +rates are the same as + +real interest rates, and that's +why the interest rates + +you see posted are so incredibly +low because there's + +no inflation. + +In the late 1970's, when +inflation was running at + +10-15% a year, interest rates +were 15 to 20% a year. + +Now it wasn't that you could +get so much more for your + +savings in the 1970's. + +It was just that stuff was going +to cost more next year, + +so banks, if they wanted to +induce you to save, had to pay + +you a higher interest rate. + +So, essentially, banks are going +to have to pay you to + +get you to put your money in. + +If in 1978, when the inflation +rate was 15%-- + +if banks had offered a 3% +interest rate no one would've + +put money in the banks because +you would end up losing + +effectively. + +Effectively, that's a negative +12% real interest rate. + +So what matters is how much +the bank pays you in cash + +minus how much more stuff is +going to cost. And that's + +often what matters. + +Now that's a distinction +we won't spent a lot of + +time on later on. + +I'll just say interest rate. + +I won't say real +versus nominal. + +But you've got to know in your +head that what matters is the + +interest rate is the real +interest rate, what the bank + +pays you, minus how much more +stuff's going to cost. + +Questions about that? + +Alright, we'll come +back next time. + +There is class on Wednesday. + +It does matter. + +And on Wednesday we're going +to talk about the rest of + +capital markets and people's +savings decisions. \ No newline at end of file diff --git a/er_tQOBgo-I.txt b/er_tQOBgo-I.txt new file mode 100644 index 0000000000000000000000000000000000000000..226e9ff20a2227521fa9b0435288184e96de2e85 --- /dev/null +++ b/er_tQOBgo-I.txt @@ -0,0 +1,2299 @@ +align:start position:0% + +hi welcome back to recitation today I + + align:start position:0% +hi welcome back to recitation today I + + + align:start position:0% +hi welcome back to recitation today I +wanted to talk about something that's + + align:start position:0% +wanted to talk about something that's + + + align:start position:0% +wanted to talk about something that's +mentioned in the notes but wasn't + + align:start position:0% +mentioned in the notes but wasn't + + + align:start position:0% +mentioned in the notes but wasn't +covered in lecture because of the exam + + align:start position:0% +covered in lecture because of the exam + + + align:start position:0% +covered in lecture because of the exam +review so this is uh the the subject is + + align:start position:0% +review so this is uh the the subject is + + + align:start position:0% +review so this is uh the the subject is +hyperbolic trig functions so first I + + align:start position:0% +hyperbolic trig functions so first I + + + align:start position:0% +hyperbolic trig functions so first I +just want to Define them for you and + + align:start position:0% +just want to Define them for you and + + + align:start position:0% +just want to Define them for you and +graph them so we can get a little bit of + + align:start position:0% +graph them so we can get a little bit of + + + align:start position:0% +graph them so we can get a little bit of +a feeling for what these functions are + + align:start position:0% +a feeling for what these functions are + + + align:start position:0% +a feeling for what these functions are +like and then I'm going to explain to + + align:start position:0% +like and then I'm going to explain to + + + align:start position:0% +like and then I'm going to explain to +you why they have the words Hy + + align:start position:0% +you why they have the words Hy + + + align:start position:0% +you why they have the words Hy +hyperbolic and trig in their names um so + + align:start position:0% +hyperbolic and trig in their names um so + + + align:start position:0% +hyperbolic and trig in their names um so +these are these are some interesting + + align:start position:0% +these are these are some interesting + + + align:start position:0% +these are these are some interesting +functions they're not they don't they + + align:start position:0% +functions they're not they don't they + + + align:start position:0% +functions they're not they don't they +don't aren't quite as important as your + + align:start position:0% +don't aren't quite as important as your + + + align:start position:0% +don't aren't quite as important as your +usual sort of circular trig functions + + align:start position:0% +usual sort of circular trig functions + + + align:start position:0% +usual sort of circular trig functions +but but um but but yeah so let me let me + + align:start position:0% +but but um but but yeah so let me let me + + + align:start position:0% +but but um but but yeah so let me let me +introduce them and let me jump in just + + align:start position:0% +introduce them and let me jump in just + + + align:start position:0% +introduce them and let me jump in just +with their definition so so there are + + align:start position:0% +with their definition so so there are + + + align:start position:0% +with their definition so so there are +there are two most important ones just + + align:start position:0% +there are two most important ones just + + + align:start position:0% +there are two most important ones just +like for regular trigonometric functions + + align:start position:0% +like for regular trigonometric functions + + + align:start position:0% +like for regular trigonometric functions +there's the sign and the cosine and then + + align:start position:0% +there's the sign and the cosine and then + + + align:start position:0% +there's the sign and the cosine and then +you can write the other four + + align:start position:0% +you can write the other four + + + align:start position:0% +you can write the other four +trigonometric functions in terms of them + + align:start position:0% +trigonometric functions in terms of them + + + align:start position:0% +trigonometric functions in terms of them +so for hyperbolic Tri functions we have + + align:start position:0% +so for hyperbolic Tri functions we have + + + align:start position:0% +so for hyperbolic Tri functions we have +the hyperbolic cosine and the hyperbolic + + align:start position:0% +the hyperbolic cosine and the hyperbolic + + + align:start position:0% +the hyperbolic cosine and the hyperbolic +sign so the notation here we write C So + + align:start position:0% +sign so the notation here we write C So + + + align:start position:0% +sign so the notation here we write C So +Co the H for hyperbolic so hyperbolic + + align:start position:0% +Co the H for hyperbolic so hyperbolic + + + align:start position:0% +Co the H for hyperbolic so hyperbolic +cosine and usually we pronounce this Kos + + align:start position:0% +cosine and usually we pronounce this Kos + + + align:start position:0% +cosine and usually we pronounce this Kos +um and similarly for the hyperbolic sign + + align:start position:0% +um and similarly for the hyperbolic sign + + + align:start position:0% +um and similarly for the hyperbolic sign +we write SI i n for hyperbolic sign + + align:start position:0% +we write SI i n for hyperbolic sign + + + align:start position:0% +we write SI i n for hyperbolic sign +except in the reverse order and we + + align:start position:0% +except in the reverse order and we + + + align:start position:0% +except in the reverse order and we +usually pronounce this cinch uh so in in + + align:start position:0% +usually pronounce this cinch uh so in in + + + align:start position:0% +usually pronounce this cinch uh so in in +American English as if there were an + + align:start position:0% +American English as if there were an + + + align:start position:0% +American English as if there were an +extra c in there cinch um so okay so + + align:start position:0% +extra c in there cinch um so okay so + + + align:start position:0% +extra c in there cinch um so okay so +these these functions have fairly simp + + align:start position:0% +these these functions have fairly simp + + + align:start position:0% +these these functions have fairly simp +simple definitions in terms of the + + align:start position:0% +simple definitions in terms of the + + + align:start position:0% +simple definitions in terms of the +exponential function e x so C of X is + + align:start position:0% +exponential function e x so C of X is + + + align:start position:0% +exponential function e x so C of X is +defined to be E X Plus e- x / 2 and + + align:start position:0% +defined to be E X Plus e- x / 2 and + + + align:start position:0% +defined to be E X Plus e- x / 2 and +cinch of X is defined to be e x minus e- + + align:start position:0% +cinch of X is defined to be e x minus e- + + + align:start position:0% +cinch of X is defined to be e x minus e- +x divided two so if you remember what + + align:start position:0% +x divided two so if you remember what + + + align:start position:0% +x divided two so if you remember what +your graph of e to the X looks like and + + align:start position:0% +your graph of e to the X looks like and + + + align:start position:0% +your graph of e to the X looks like and +your graph of e to the minus X it's not + + align:start position:0% +your graph of e to the minus X it's not + + + align:start position:0% +your graph of e to the minus X it's not +hard to see that the graphs of Kos X and + + align:start position:0% +hard to see that the graphs of Kos X and + + + align:start position:0% +hard to see that the graphs of Kos X and +cinch X should look sort of like this so + + align:start position:0% +cinch X should look sort of like this so + + + align:start position:0% +cinch X should look sort of like this so +for Kosh X so we see as X gets big so e + + align:start position:0% +for Kosh X so we see as X gets big so e + + + align:start position:0% +for Kosh X so we see as X gets big so e +to Theus X is going to zero it's not + + align:start position:0% +to Theus X is going to zero it's not + + + align:start position:0% +to Theus X is going to zero it's not +very important so it mostly is driven by + + align:start position:0% +very important so it mostly is driven by + + + align:start position:0% +very important so it mostly is driven by +this e to the X part and as e as X gets + + align:start position:0% +this e to the X part and as e as X gets + + + align:start position:0% +this e to the X part and as e as X gets +negative and big uh then this is going + + align:start position:0% +negative and big uh then this is going + + + align:start position:0% +negative and big uh then this is going +to zero and this is getting larger and + + align:start position:0% +to zero and this is getting larger and + + + align:start position:0% +to zero and this is getting larger and +larger so we get something that looks + + align:start position:0% +larger so we get something that looks + + + align:start position:0% +larger so we get something that looks +like this so it it looks a little bit in + + align:start position:0% +like this so it it looks a little bit in + + + align:start position:0% +like this so it it looks a little bit in +this picture it looks a little bit like + + align:start position:0% +this picture it looks a little bit like + + + align:start position:0% +this picture it looks a little bit like +a parabola but the growth here is + + align:start position:0% +a parabola but the growth here is + + + align:start position:0% +a parabola but the growth here is +exponential at both sides so in fact + + align:start position:0% +exponential at both sides so in fact + + + align:start position:0% +exponential at both sides so in fact +this is growing much much much faster + + align:start position:0% +this is growing much much much faster + + + align:start position:0% +this is growing much much much faster +than say 1 plus x^2 um so it's a much a + + align:start position:0% +than say 1 plus x^2 um so it's a much a + + + align:start position:0% +than say 1 plus x^2 um so it's a much a +much steeper + + align:start position:0% +much steeper + + + align:start position:0% +much steeper +curve um okay and it reaches its minimum + + align:start position:0% +curve um okay and it reaches its minimum + + + align:start position:0% +curve um okay and it reaches its minimum +here at xals 0 it has the value 1 + one + + align:start position:0% +here at xals 0 it has the value 1 + one + + + align:start position:0% +here at xals 0 it has the value 1 + one +over two so that's so its minimum there + + align:start position:0% +over two so that's so its minimum there + + + align:start position:0% +over two so that's so its minimum there +is that is x equals z it has its minimum + + align:start position:0% +is that is x equals z it has its minimum + + + align:start position:0% +is that is x equals z it has its minimum +value one for cinch okay so we're taking + + align:start position:0% +value one for cinch okay so we're taking + + + align:start position:0% +value one for cinch okay so we're taking +the difference of them so it's it's + + align:start position:0% +the difference of them so it's it's + + + align:start position:0% +the difference of them so it's it's +similar when X is uh positive and large + + align:start position:0% +similar when X is uh positive and large + + + align:start position:0% +similar when X is uh positive and large +e to the x is big and e to the minus X + + align:start position:0% +e to the x is big and e to the minus X + + + align:start position:0% +e to the x is big and e to the minus X +is is pretty small almost negligible so + + align:start position:0% +is is pretty small almost negligible so + + + align:start position:0% +is is pretty small almost negligible so +we get exponential growth off that side + + align:start position:0% +we get exponential growth off that side + + + align:start position:0% +we get exponential growth off that side +when X becomes negative and large e to + + align:start position:0% +when X becomes negative and large e to + + + align:start position:0% +when X becomes negative and large e to +the x is going to zero e Theus X is + + align:start position:0% +the x is going to zero e Theus X is + + + align:start position:0% +the x is going to zero e Theus X is +becoming large but it's it's we've got a + + align:start position:0% +becoming large but it's it's we've got a + + + align:start position:0% +becoming large but it's it's we've got a +minus sign here so as X goes to minus + + align:start position:0% +minus sign here so as X goes to minus + + + align:start position:0% +minus sign here so as X goes to minus +infinity this curve goes also to minus + + align:start position:0% +infinity this curve goes also to minus + + + align:start position:0% +infinity this curve goes also to minus +infinity and again the growth here is is + + align:start position:0% +infinity and again the growth here is is + + + align:start position:0% +infinity and again the growth here is is +exponential in in both cases um and if + + align:start position:0% +exponential in in both cases um and if + + + align:start position:0% +exponential in in both cases um and if +you you know if you were curious say + + align:start position:0% +you you know if you were curious say + + + align:start position:0% +you you know if you were curious say +about what the slope there at the origin + + align:start position:0% +about what the slope there at the origin + + + align:start position:0% +about what the slope there at the origin +is you could quickly take a derivative + + align:start position:0% +is you could quickly take a derivative + + + align:start position:0% +is you could quickly take a derivative +and check that that that's passing + + align:start position:0% +and check that that that's passing + + + align:start position:0% +and check that that that's passing +through the origin with slope one there + + align:start position:0% +through the origin with slope one there + + + align:start position:0% +through the origin with slope one there +um okay so this is a sort of basic + + align:start position:0% +um okay so this is a sort of basic + + + align:start position:0% +um okay so this is a sort of basic +picture of what these curves look like + + align:start position:0% +picture of what these curves look like + + + align:start position:0% +picture of what these curves look like +um they have some nice properties um and + + align:start position:0% +um they have some nice properties um and + + + align:start position:0% +um they have some nice properties um and +let me talk about them so for example um + + align:start position:0% +let me talk about them so for example um + + + align:start position:0% +let me talk about them so for example um +one nice thing you might notice about + + align:start position:0% +one nice thing you might notice about + + + align:start position:0% +one nice thing you might notice about +these functions is that it's easy to + + align:start position:0% +these functions is that it's easy to + + + align:start position:0% +these functions is that it's easy to +compute their derivatives right so if we + + align:start position:0% +compute their derivatives right so if we + + + align:start position:0% +compute their derivatives right so if we +look + + align:start position:0% +look + + + align:start position:0% +look +at + + align:start position:0% + + + + align:start position:0% + +DDX of Co Kos X X in order to compute + + align:start position:0% +DDX of Co Kos X X in order to compute + + + align:start position:0% +DDX of Co Kos X X in order to compute +that well just look at the definition of + + align:start position:0% +that well just look at the definition of + + + align:start position:0% +that well just look at the definition of +of C right so it's it's really just a + + align:start position:0% +of C right so it's it's really just a + + + align:start position:0% +of C right so it's it's really just a +sum of two exponential functions + + align:start position:0% +sum of two exponential functions + + + align:start position:0% +sum of two exponential functions +exponential functions are easy to take + + align:start position:0% +exponential functions are easy to take + + + align:start position:0% +exponential functions are easy to take +the derivatives take the derivative of e + + align:start position:0% +the derivatives take the derivative of e + + + align:start position:0% +the derivatives take the derivative of e +to the X you get e to the X take the + + align:start position:0% +to the X you get e to the X take the + + + align:start position:0% +to the X you get e to the X take the +derivative of e to the minus X well okay + + align:start position:0% +derivative of e to the minus X well okay + + + align:start position:0% +derivative of e to the minus X well okay +so it's a little chain rule so you get a + + align:start position:0% +so it's a little chain rule so you get a + + + align:start position:0% +so it's a little chain rule so you get a +minus one in front so the derivative of + + align:start position:0% +minus one in front so the derivative of + + + align:start position:0% +minus one in front so the derivative of +Kos X is e x minus e- X over two but we + + align:start position:0% +Kos X is e x minus e- X over two but we + + + align:start position:0% +Kos X is e x minus e- X over two but we +have a name for this this is actually + + align:start position:0% +have a name for this this is actually + + + align:start position:0% +have a name for this this is actually +just + + align:start position:0% + + + + align:start position:0% + +cinch X so the derivative of Kosh is + + align:start position:0% +cinch X so the derivative of Kosh is + + + align:start position:0% +cinch X so the derivative of Kosh is +cinch and the + + align:start position:0% + + + + align:start position:0% + +derivative of cinch well you okay you + + align:start position:0% +derivative of cinch well you okay you + + + align:start position:0% +derivative of cinch well you okay you +look at the same thing take this this + + align:start position:0% +look at the same thing take this this + + + align:start position:0% +look at the same thing take this this +formula take its derivative well e to + + align:start position:0% +formula take its derivative well e to + + + align:start position:0% +formula take its derivative well e to +the X take its derivative you get e to x + + align:start position:0% +the X take its derivative you get e to x + + + align:start position:0% +the X take its derivative you get e to x +e to Theus X take its derivative you get + + align:start position:0% +e to Theus X take its derivative you get + + + align:start position:0% +e to Theus X take its derivative you get +minus E to Theus X so those two minus + + align:start position:0% +minus E to Theus X so those two minus + + + align:start position:0% +minus E to Theus X so those two minus +signs cancel out and become a plus so + + align:start position:0% +signs cancel out and become a plus so + + + align:start position:0% +signs cancel out and become a plus so +this is E X Plus e- X over + + align:start position:0% + + + + align:start position:0% + +which is k x so here you have some + + align:start position:0% +which is k x so here you have some + + + align:start position:0% +which is k x so here you have some +Behavior that's a little bit reminiscent + + align:start position:0% +Behavior that's a little bit reminiscent + + + align:start position:0% +Behavior that's a little bit reminiscent +of the behavior of trig functions right + + align:start position:0% +of the behavior of trig functions right + + + align:start position:0% +of the behavior of trig functions right +for trig functions if you take the + + align:start position:0% +for trig functions if you take the + + + align:start position:0% +for trig functions if you take the +derivative of s you get cosine and if + + align:start position:0% +derivative of s you get cosine and if + + + align:start position:0% +derivative of s you get cosine and if +you take the derivative of cosine you + + align:start position:0% +you take the derivative of cosine you + + + align:start position:0% +you take the derivative of cosine you +almost get back sign but you get minus + + align:start position:0% +almost get back sign but you get minus + + + align:start position:0% +almost get back sign but you get minus +sign so here you don't have that extra + + align:start position:0% +sign so here you don't have that extra + + + align:start position:0% +sign so here you don't have that extra +negative sign floating around right so + + align:start position:0% +negative sign floating around right so + + + align:start position:0% +negative sign floating around right so +you when you take the derivative of C + + align:start position:0% +you when you take the derivative of C + + + align:start position:0% +you when you take the derivative of C +you get cinch on the nose no no minus + + align:start position:0% +you get cinch on the nose no no minus + + + align:start position:0% +you get cinch on the nose no no minus +sign needed um so that's interesting um + + align:start position:0% +sign needed um so that's interesting um + + + align:start position:0% +sign needed um so that's interesting um +but the real reason that these are that + + align:start position:0% +but the real reason that these are that + + + align:start position:0% +but the real reason that these are that +these have the words trig in their name + + align:start position:0% +these have the words trig in their name + + + align:start position:0% +these have the words trig in their name +is um is is actually a little bit deeper + + align:start position:0% +is um is is actually a little bit deeper + + + align:start position:0% +is um is is actually a little bit deeper +so let me come over here and draw a + + align:start position:0% +so let me come over here and draw a + + + align:start position:0% +so let me come over here and draw a +couple pictures so the the the the + + align:start position:0% +couple pictures so the the the the + + + align:start position:0% +couple pictures so the the the the +normal trig functions what sometimes we + + align:start position:0% +normal trig functions what sometimes we + + + align:start position:0% +normal trig functions what sometimes we +call the circular trig functions if we + + align:start position:0% +call the circular trig functions if we + + + align:start position:0% +call the circular trig functions if we +want to distinguish them from the + + align:start position:0% +want to distinguish them from the + + + align:start position:0% +want to distinguish them from the +hyperbolic trig functions um they're + + align:start position:0% +hyperbolic trig functions um they're + + + align:start position:0% +hyperbolic trig functions um they're +they're closely so circular trig + + align:start position:0% +they're closely so circular trig + + + align:start position:0% +they're closely so circular trig +functions they're closely related to the + + align:start position:0% +functions they're closely related to the + + + align:start position:0% +functions they're closely related to the +unit circle so the unit circle + + align:start position:0% +unit circle so the unit circle + + + align:start position:0% +unit circle so the unit circle +has equation x^2 + y^2 = + + align:start position:0% +has equation x^2 + y^2 = + + + align:start position:0% +has equation x^2 + y^2 = +1 it's a circle well it's close enough + + align:start position:0% +1 it's a circle well it's close enough + + + align:start position:0% +1 it's a circle well it's close enough +right um and what what is the the nice + + align:start position:0% +right um and what what is the the nice + + + align:start position:0% +right um and what what is the the nice +relationship between this circle and the + + align:start position:0% +relationship between this circle and the + + + align:start position:0% +relationship between this circle and the +trig functions well if you choose any + + align:start position:0% +trig functions well if you choose any + + + align:start position:0% +trig functions well if you choose any +point on this circle then there exists + + align:start position:0% +point on this circle then there exists + + + align:start position:0% +point on this circle then there exists +some value of t such that this point has + + align:start position:0% +some value of t such that this point has + + + align:start position:0% +some value of t such that this point has +coordinates cosine T + + align:start position:0% +coordinates cosine T + + + align:start position:0% +coordinates cosine T +comma sin T now it happens that the the + + align:start position:0% +comma sin T now it happens that the the + + + align:start position:0% +comma sin T now it happens that the the +that the value of T is actually the the + + align:start position:0% +that the value of T is actually the the + + + align:start position:0% +that the value of T is actually the the +angle that that radius makes with the + + align:start position:0% +angle that that radius makes with the + + + align:start position:0% +angle that that radius makes with the +Positive x-axis but but not going to + + align:start position:0% +Positive x-axis but but not going to + + + align:start position:0% +Positive x-axis but but not going to +worry about that right now it's not the + + align:start position:0% +worry about that right now it's not the + + + align:start position:0% +worry about that right now it's not the +key idea of import so as T varies + + align:start position:0% +key idea of import so as T varies + + + align:start position:0% +key idea of import so as T varies +through the the real numbers the point + + align:start position:0% +through the the real numbers the point + + + align:start position:0% +through the the real numbers the point +cosine T sin T that varies and it just + + align:start position:0% +cosine T sin T that varies and it just + + + align:start position:0% +cosine T sin T that varies and it just +goes around this curve so it traces out + + align:start position:0% +goes around this curve so it traces out + + + align:start position:0% +goes around this curve so it traces out +this circle exactly so the hyperbolic + + align:start position:0% +this circle exactly so the hyperbolic + + + align:start position:0% +this circle exactly so the hyperbolic +trig functions um show up in a in a very + + align:start position:0% +trig functions um show up in a in a very + + + align:start position:0% +trig functions um show up in a in a very +similar situation but instead of looking + + align:start position:0% +similar situation but instead of looking + + + align:start position:0% +similar situation but instead of looking +at the unit circle what we want to look + + align:start position:0% +at the unit circle what we want to look + + + align:start position:0% +at the unit circle what we want to look +at is the unit rectangular hyperbola uh + + align:start position:0% +at is the unit rectangular hyperbola uh + + + align:start position:0% +at is the unit rectangular hyperbola uh +so what do I mean by that well so + + align:start position:0% +so what do I mean by that well so + + + align:start position:0% +so what do I mean by that well so +instead of taking the equation x^2 + y^2 + + align:start position:0% +instead of taking the equation x^2 + y^2 + + + align:start position:0% +instead of taking the equation x^2 + y^2 += 1 which gives a circle I'm going to + + align:start position:0% += 1 which gives a circle I'm going to + + + align:start position:0% += 1 which gives a circle I'm going to +look at a very similar equation that + + align:start position:0% +look at a very similar equation that + + + align:start position:0% +look at a very similar equation that +gives a hyperbola so this is the + + align:start position:0% +gives a hyperbola so this is the + + + align:start position:0% +gives a hyperbola so this is the +equation + + align:start position:0% +equation + + + align:start position:0% +equation +x^2 - y^2 = 1 so if you if you graph the + + align:start position:0% +x^2 - y^2 = 1 so if you if you graph the + + + align:start position:0% +x^2 - y^2 = 1 so if you if you graph the +this this equation what you'll see is + + align:start position:0% +this this equation what you'll see is + + + align:start position:0% +this this equation what you'll see is +that well passes through the point one Z + + align:start position:0% +that well passes through the point one Z + + + align:start position:0% +that well passes through the point one Z +and + + align:start position:0% + + + + align:start position:0% + +then we've got one branch here it's got + + align:start position:0% +then we've got one branch here it's got + + + align:start position:0% +then we've got one branch here it's got +a little ASM toote + + align:start position:0% +a little ASM toote + + + align:start position:0% +a little ASM toote +there and it's got all + + align:start position:0% +there and it's got all + + + align:start position:0% +there and it's got all +right so it's got a right Branch like + + align:start position:0% +right so it's got a right Branch like + + + align:start position:0% +right so it's got a right Branch like +that and also it's symmetric across the + + align:start position:0% +that and also it's symmetric across the + + + align:start position:0% +that and also it's symmetric across the +y AIS so there's + + align:start position:0% +y AIS so there's + + + align:start position:0% +y AIS so there's +a a symmetric + + align:start position:0% + + + + align:start position:0% + +left Branch here so this is the graph of + + align:start position:0% +left Branch here so this is the graph of + + + align:start position:0% +left Branch here so this is the graph of +the equation x^2 - y^2 = 1 so it's this + + align:start position:0% +the equation x^2 - y^2 = 1 so it's this + + + align:start position:0% +the equation x^2 - y^2 = 1 so it's this +this + + align:start position:0% +this + + + align:start position:0% +this +hyperbola now um what I claim is that + + align:start position:0% +hyperbola now um what I claim is that + + + align:start position:0% +hyperbola now um what I claim is that +Kos and cinch have the same relationship + + align:start position:0% +Kos and cinch have the same relationship + + + align:start position:0% +Kos and cinch have the same relationship +to this hyperbola as cosine and S have + + align:start position:0% +to this hyperbola as cosine and S have + + + align:start position:0% +to this hyperbola as cosine and S have +to the circle well all right so it's I'm + + align:start position:0% +to the circle well all right so it's I'm + + + align:start position:0% +to the circle well all right so it's I'm +fudging a little bit so it turns out + + align:start position:0% +fudging a little bit so it turns out + + + align:start position:0% +fudging a little bit so it turns out +it's only the right half of the + + align:start position:0% +it's only the right half of the + + + align:start position:0% +it's only the right half of the +hyperbola um so what do I mean by that + + align:start position:0% +hyperbola um so what do I mean by that + + + align:start position:0% +hyperbola um so what do I mean by that +well here's what I'd like to do set + + align:start position:0% +well here's what I'd like to do set + + + align:start position:0% +well here's what I'd like to do set +x equals so we're going to introduce a + + align:start position:0% +x equals so we're going to introduce a + + + align:start position:0% +x equals so we're going to introduce a +new variable U and I'm going to set x + + align:start position:0% +new variable U and I'm going to set x + + + align:start position:0% +new variable U and I'm going to set x +equal c u and Y + + align:start position:0% +equal c u and Y + + + align:start position:0% +equal c u and Y +equals cinch U and now I'm going to look + + align:start position:0% +equals cinch U and now I'm going to look + + + align:start position:0% +equals cinch U and now I'm going to look +at the the quantity x^2 minus y^2 so + + align:start position:0% +at the the quantity x^2 minus y^2 so + + + align:start position:0% +at the the quantity x^2 minus y^2 so +x^2 minus y^2 so this + + align:start position:0% +x^2 minus y^2 so this + + + align:start position:0% +x^2 minus y^2 so this +is so we use most of the same notations + + align:start position:0% +is so we use most of the same notations + + + align:start position:0% +is so we use most of the same notations +for hyperbolic trig functions that we do + + align:start position:0% +for hyperbolic trig functions that we do + + + align:start position:0% +for hyperbolic trig functions that we do +for regular trig functions so this is c^ + + align:start position:0% +for regular trig functions so this is c^ + + + align:start position:0% +for regular trig functions so this is c^ +2 U minus + + align:start position:0% +2 U minus + + + align:start position:0% +2 U minus +minus cinch 2 + + align:start position:0% +minus cinch 2 + + + align:start position:0% +minus cinch 2 +U and now we can plug in the formulas + + align:start position:0% +U and now we can plug in the formulas + + + align:start position:0% +U and now we can plug in the formulas +for caution cinch that we have so this + + align:start position:0% +for caution cinch that we have so this + + + align:start position:0% +for caution cinch that we have so this +is equal + + align:start position:0% +is equal + + + align:start position:0% +is equal +to e to the U + e minus U over 2^ 2ar + + align:start position:0% +to e to the U + e minus U over 2^ 2ar + + + align:start position:0% +to e to the U + e minus U over 2^ 2ar +minus E U minus eus U over two quantity + + align:start position:0% +minus E U minus eus U over two quantity + + + align:start position:0% +minus E U minus eus U over two quantity +squared and now we can expand out both + + align:start position:0% +squared and now we can expand out both + + + align:start position:0% +squared and now we can expand out both +of these factors and both of these + + align:start position:0% +of these factors and both of these + + + align:start position:0% +of these factors and both of these +squares rather and and put them together + + align:start position:0% +squares rather and and put them together + + + align:start position:0% +squares rather and and put them together +so all right so over 2^ 2ar is over four + + align:start position:0% +so all right so over 2^ 2ar is over four + + + align:start position:0% +so all right so over 2^ 2ar is over four +and we Square this and we get e to the 2 + + align:start position:0% +and we Square this and we get e to the 2 + + + align:start position:0% +and we Square this and we get e to the 2 +U okay so then we get 2 * e to the U * e + + align:start position:0% +U okay so then we get 2 * e to the U * e + + + align:start position:0% +U okay so then we get 2 * e to the U * e +to the minus U but e to the U * e to the + + align:start position:0% +to the minus U but e to the U * e to the + + + align:start position:0% +to the minus U but e to the U * e to the +minus U is just 1 so + + + align:start position:0% +minus U is just 1 so + + + + align:start position:0% +minus U is just 1 so + +2 plus e to Theus 2 U + + align:start position:0% +2 plus e to Theus 2 U + + + align:start position:0% +2 plus e to Theus 2 U +minus E 2 U - 2 + e- 2 U so same thing + + align:start position:0% +minus E 2 U - 2 + e- 2 U so same thing + + + align:start position:0% +minus E 2 U - 2 + e- 2 U so same thing +over here over + + align:start position:0% +over here over + + + align:start position:0% +over here over +four okay so the the e to the 2 U's + + align:start position:0% +four okay so the the e to the 2 U's + + + align:start position:0% +four okay so the the e to the 2 U's +cancel and the e to the minus 2 U's + + align:start position:0% +cancel and the e to the minus 2 U's + + + align:start position:0% +cancel and the e to the minus 2 U's +cancel and we're left with 2 - - 2 + + align:start position:0% +cancel and we're left with 2 - - 2 + + + align:start position:0% +cancel and we're left with 2 - - 2 +that's four so this is 4 over 4 so this + + align:start position:0% +that's four so this is 4 over 4 so this + + + align:start position:0% +that's four so this is 4 over 4 so this +is equal to 1 okay so if x is equal to + + align:start position:0% +is equal to 1 okay so if x is equal to + + + align:start position:0% +is equal to 1 okay so if x is equal to +kosu and Y is equal to CNU then x^2 - + + align:start position:0% +kosu and Y is equal to CNU then x^2 - + + + align:start position:0% +kosu and Y is equal to CNU then x^2 - +y^2 is equal to 1 so if we choose a + + align:start position:0% +y^2 is equal to 1 so if we choose a + + + align:start position:0% +y^2 is equal to 1 so if we choose a +point kosu C you for some U that point + + align:start position:0% +point kosu C you for some U that point + + + align:start position:0% +point kosu C you for some U that point +lies on this hyperbola that's what this + + align:start position:0% +lies on this hyperbola that's what this + + + align:start position:0% +lies on this hyperbola that's what this +says that this point okay so the point + + align:start position:0% +says that this point okay so the point + + + align:start position:0% +says that this point okay so the point +kosu cinu is somewhere on this + + align:start position:0% +kosu cinu is somewhere on this + + + align:start position:0% +kosu cinu is somewhere on this +hyperbola and what's also true is the is + + align:start position:0% +hyperbola and what's also true is the is + + + align:start position:0% +hyperbola and what's also true is the is +the sort of reverse statement if you + + align:start position:0% +the sort of reverse statement if you + + + align:start position:0% +the sort of reverse statement if you +look at all such points if you let U + + align:start position:0% +look at all such points if you let U + + + align:start position:0% +look at all such points if you let U +vary um and and look at through the real + + align:start position:0% +vary um and and look at through the real + + + align:start position:0% +vary um and and look at through the real +numbers and you ask what happens to this + + align:start position:0% +numbers and you ask what happens to this + + + align:start position:0% +numbers and you ask what happens to this +point kwu C you the answer is that it + + align:start position:0% +point kwu C you the answer is that it + + + align:start position:0% +point kwu C you the answer is that it +that it traces out the right half of + + align:start position:0% +that it traces out the right half of + + + align:start position:0% +that it traces out the right half of +this hyperbola if if you go back to the + + align:start position:0% +this hyperbola if if you go back to the + + + align:start position:0% +this hyperbola if if you go back to the +graph of of yal cos x you'll see the the + + align:start position:0% +graph of of yal cos x you'll see the the + + + align:start position:0% +graph of of yal cos x you'll see the the +the hyperbolic cosine function is always + + align:start position:0% +the hyperbolic cosine function is always + + + align:start position:0% +the hyperbolic cosine function is always +positive so we can't over here we can't + + align:start position:0% +positive so we can't over here we can't + + + align:start position:0% +positive so we can't over here we can't +trace out this left Branch where X is + + align:start position:0% +trace out this left Branch where X is + + + align:start position:0% +trace out this left Branch where X is +negative although it's easy enough to + + align:start position:0% +negative although it's easy enough to + + + align:start position:0% +negative although it's easy enough to +say what does trace out this left Branch + + align:start position:0% +say what does trace out this left Branch + + + align:start position:0% +say what does trace out this left Branch +since it's just the the mirror image + + align:start position:0% +since it's just the the mirror image + + + align:start position:0% +since it's just the the mirror image +this is traced out by minus c + + align:start position:0% +this is traced out by minus c + + + align:start position:0% +this is traced out by minus c +u + + align:start position:0% +u + + + align:start position:0% +u +comma + + align:start position:0% +comma + + + align:start position:0% +comma +cchu so there's a the so the hyperbolic + + align:start position:0% +cchu so there's a the so the hyperbolic + + + align:start position:0% +cchu so there's a the so the hyperbolic +trig functions have the same + + align:start position:0% +trig functions have the same + + + align:start position:0% +trig functions have the same +relationship to this branch of this + + align:start position:0% +relationship to this branch of this + + + align:start position:0% +relationship to this branch of this +hyperbola that the that the regular trig + + align:start position:0% +hyperbola that the that the regular trig + + + align:start position:0% +hyperbola that the that the regular trig +functions have to this circle so there + + align:start position:0% +functions have to this circle so there + + + align:start position:0% +functions have to this circle so there +there's where the words hyperbolic and + + align:start position:0% +there's where the words hyperbolic and + + + align:start position:0% +there's where the words hyperbolic and +and trig functions come from so uh let + + align:start position:0% +and trig functions come from so uh let + + + align:start position:0% +and trig functions come from so uh let +me say one more thing about them which + + align:start position:0% +me say one more thing about them which + + + align:start position:0% +me say one more thing about them which +is we saw that they have this this + + align:start position:0% +is we saw that they have this this + + + align:start position:0% +is we saw that they have this this +analogy with regular trig functions + + align:start position:0% +analogy with regular trig functions + + + align:start position:0% +analogy with regular trig functions +right so instead of satisfying cosine + + align:start position:0% +right so instead of satisfying cosine + + + align:start position:0% +right so instead of satisfying cosine +squ plus sin squ equal 1 they satisfy + + align:start position:0% +squ plus sin squ equal 1 they satisfy + + + align:start position:0% +squ plus sin squ equal 1 they satisfy +cos squ minus sin squal 1 and instead of + + align:start position:0% +cos squ minus sin squal 1 and instead of + + + align:start position:0% +cos squ minus sin squal 1 and instead of +satisfying the derivative of s equals + + align:start position:0% +satisfying the derivative of s equals + + + align:start position:0% +satisfying the derivative of s equals +cosine and the derivative of cosine + + align:start position:0% +cosine and the derivative of cosine + + + align:start position:0% +cosine and the derivative of cosine +equals minus sign they satisfy + + align:start position:0% +equals minus sign they satisfy + + + align:start position:0% +equals minus sign they satisfy +derivative of Kosh equals cinch and + + align:start position:0% +derivative of Kosh equals cinch and + + + align:start position:0% +derivative of Kosh equals cinch and +derivative of cinch equals Kos so + + align:start position:0% +derivative of cinch equals Kos so + + + align:start position:0% +derivative of cinch equals Kos so +similar relationships not exactly the + + align:start position:0% +similar relationships not exactly the + + + align:start position:0% +similar relationships not exactly the +same but similar um so this is true of a + + align:start position:0% +same but similar um so this is true of a + + + align:start position:0% +same but similar um so this is true of a +lot of trig relationships that that + + align:start position:0% +lot of trig relationships that that + + + align:start position:0% +lot of trig relationships that that +there's a corresponding uh formula for + + align:start position:0% +there's a corresponding uh formula for + + + align:start position:0% +there's a corresponding uh formula for +the hyperbolic trig functions so one + + align:start position:0% +the hyperbolic trig functions so one + + + align:start position:0% +the hyperbolic trig functions so one +example of such a formula is is your for + + align:start position:0% +example of such a formula is is your for + + + align:start position:0% +example of such a formula is is your for +example your angle addition formulas so + + align:start position:0% +example your angle addition formulas so + + + align:start position:0% +example your angle addition formulas so +I'm going to just leave this as an + + align:start position:0% +I'm going to just leave this as an + + + align:start position:0% +I'm going to just leave this as an +exercise for you um so let me I guess + + align:start position:0% +exercise for you um so let me I guess + + + align:start position:0% +exercise for you um so let me I guess +I'll just stick it in this funny little + + align:start position:0% +I'll just stick it in this funny little + + + align:start position:0% +I'll just stick it in this funny little +piece of board right here + + align:start position:0% +piece of board right here + + + align:start position:0% +piece of board right here +so + + align:start position:0% + + + + align:start position:0% + +exercise + + align:start position:0% +exercise + + + align:start position:0% +exercise +find + + align:start position:0% +find + + + align:start position:0% +find +cinch of x + + + align:start position:0% + + + + align:start position:0% + +y and + + align:start position:0% +y and + + + align:start position:0% +y and +Kos of X+ + + align:start position:0% + + + + align:start position:0% + +Y in + + align:start position:0% +Y in + + + align:start position:0% +Y in +terms of + + align:start position:0% + + + + align:start position:0% + +cinch + + align:start position:0% +cinch + + + align:start position:0% +cinch +X Kosh + + align:start position:0% +X Kosh + + + align:start position:0% +X Kosh +X cinch + + align:start position:0% + + + + align:start position:0% + +Y and Kosh y so in other words find the + + align:start position:0% +Y and Kosh y so in other words find the + + + align:start position:0% +Y and Kosh y so in other words find the +corresponding formula to the angle + + align:start position:0% +corresponding formula to the angle + + + align:start position:0% +corresponding formula to the angle +addition formula in the case of the + + align:start position:0% +addition formula in the case of the + + + align:start position:0% +addition formula in the case of the +hyperbolic trig functions so I'll leave + + align:start position:0% +hyperbolic trig functions so I'll leave + + + align:start position:0% +hyperbolic trig functions so I'll leave +you with that \ No newline at end of file diff --git a/fQXFHIsvV-c.txt b/fQXFHIsvV-c.txt new file mode 100644 index 0000000000000000000000000000000000000000..5d9ae12d08382ef6f5e21027c03444f4fde4f374 --- /dev/null +++ b/fQXFHIsvV-c.txt @@ -0,0 +1,955 @@ +align:start position:0% + +after Watson has completed the initial + + align:start position:0% +after Watson has completed the initial + + + align:start position:0% +after Watson has completed the initial +two steps of question analysis and + + align:start position:0% +two steps of question analysis and + + + align:start position:0% +two steps of question analysis and +hypothesis generation it's then time to + + align:start position:0% +hypothesis generation it's then time to + + + align:start position:0% +hypothesis generation it's then time to +move on to step three where each of the + + align:start position:0% +move on to step three where each of the + + + align:start position:0% +move on to step three where each of the +hypotheses are scored in this step + + align:start position:0% +hypotheses are scored in this step + + + align:start position:0% +hypotheses are scored in this step +Watson computes confidence levels for + + align:start position:0% +Watson computes confidence levels for + + + align:start position:0% +Watson computes confidence levels for +each possible answer or hypothesis this + + align:start position:0% +each possible answer or hypothesis this + + + align:start position:0% +each possible answer or hypothesis this +is necessary to accurately estimate the + + align:start position:0% +is necessary to accurately estimate the + + + align:start position:0% +is necessary to accurately estimate the +probability of a proposed answer being + + align:start position:0% +probability of a proposed answer being + + + align:start position:0% +probability of a proposed answer being +correct Watson will only buzz in to + + align:start position:0% +correct Watson will only buzz in to + + + align:start position:0% +correct Watson will only buzz in to +answer a question if a confidence level + + align:start position:0% +answer a question if a confidence level + + + align:start position:0% +answer a question if a confidence level +from one of the hypotheses is above a + + align:start position:0% +from one of the hypotheses is above a + + + align:start position:0% +from one of the hypotheses is above a +threshold to compute these confidence + + align:start position:0% +threshold to compute these confidence + + + align:start position:0% +threshold to compute these confidence +levels Watson combines a large number of + + align:start position:0% +levels Watson combines a large number of + + + align:start position:0% +levels Watson combines a large number of +different methods first Watson starts + + align:start position:0% +different methods first Watson starts + + + align:start position:0% +different methods first Watson starts +with lightweight scoring algorithms to + + align:start position:0% +with lightweight scoring algorithms to + + + align:start position:0% +with lightweight scoring algorithms to +prune down the large set of hypotheses + + align:start position:0% +prune down the large set of hypotheses + + + align:start position:0% +prune down the large set of hypotheses +recall that in step two about 200 + + align:start position:0% +recall that in step two about 200 + + + align:start position:0% +recall that in step two about 200 +different hypotheses were generated an + + align:start position:0% +different hypotheses were generated an + + + align:start position:0% +different hypotheses were generated an +example of a lightweight scoring + + align:start position:0% +example of a lightweight scoring + + + align:start position:0% +example of a lightweight scoring +algorithm is computing the likelihood + + align:start position:0% +algorithm is computing the likelihood + + + align:start position:0% +algorithm is computing the likelihood +that a candidate answer is actually an + + align:start position:0% +that a candidate answer is actually an + + + align:start position:0% +that a candidate answer is actually an +instance of the lap for the Mozart + + align:start position:0% +instance of the lap for the Mozart + + + align:start position:0% +instance of the lap for the Mozart +Symphony question where the lat is this + + align:start position:0% +Symphony question where the lat is this + + + align:start position:0% +Symphony question where the lat is this +planet a candidate answer like Earth + + align:start position:0% +planet a candidate answer like Earth + + + align:start position:0% +planet a candidate answer like Earth +would have a very high score but a + + align:start position:0% +would have a very high score but a + + + align:start position:0% +would have a very high score but a +candidate answer like the moon would + + align:start position:0% +candidate answer like the moon would + + + align:start position:0% +candidate answer like the moon would +have a lower score if the likelihood is + + align:start position:0% +have a lower score if the likelihood is + + + align:start position:0% +have a lower score if the likelihood is +not very high Watson throws away the + + align:start position:0% +not very high Watson throws away the + + + align:start position:0% +not very high Watson throws away the +hypothesis the candidate answers that + + align:start position:0% +hypothesis the candidate answers that + + + align:start position:0% +hypothesis the candidate answers that +pass this death proceed to the next + + align:start position:0% +pass this death proceed to the next + + + align:start position:0% +pass this death proceed to the next +stage of the scoring algorithms Watson + + align:start position:0% +stage of the scoring algorithms Watson + + + align:start position:0% +stage of the scoring algorithms Watson +let's about 100 candidate answers pass + + align:start position:0% +let's about 100 candidate answers pass + + + align:start position:0% +let's about 100 candidate answers pass +on to the next stage then Watson moves + + align:start position:0% +on to the next stage then Watson moves + + + align:start position:0% +on to the next stage then Watson moves +into more advanced scoring analytics + + align:start position:0% +into more advanced scoring analytics + + + align:start position:0% +into more advanced scoring analytics +Watson needs to gather supporting + + align:start position:0% +Watson needs to gather supporting + + + align:start position:0% +Watson needs to gather supporting +evidence for each candidate answer one + + align:start position:0% +evidence for each candidate answer one + + + align:start position:0% +evidence for each candidate answer one +way of doing this is through a method + + align:start position:0% +way of doing this is through a method + + + align:start position:0% +way of doing this is through a method +called passage search where passages are + + align:start position:0% +called passage search where passages are + + + align:start position:0% +called passage search where passages are +retrieved that contain the hypothesis + + align:start position:0% +retrieved that contain the hypothesis + + + align:start position:0% +retrieved that contain the hypothesis +text to simulate this let's see what + + align:start position:0% +text to simulate this let's see what + + + align:start position:0% +text to simulate this let's see what +happens when we search for two of our + + align:start position:0% +happens when we search for two of our + + + align:start position:0% +happens when we search for two of our +hypotheses on Google our first + + align:start position:0% +hypotheses on Google our first + + + align:start position:0% +hypotheses on Google our first +hypothesis is Mozart's last and perhaps + + align:start position:0% +hypothesis is Mozart's last and perhaps + + + align:start position:0% +hypothesis is Mozart's last and perhaps +most powerful Symphony shares its name + + align:start position:0% +most powerful Symphony shares its name + + + align:start position:0% +most powerful Symphony shares its name +with Mercury and our second hypothesis + + align:start position:0% +with Mercury and our second hypothesis + + + align:start position:0% +with Mercury and our second hypothesis +is Mozart's last and perhaps most + + align:start position:0% +is Mozart's last and perhaps most + + + align:start position:0% +is Mozart's last and perhaps most +powerful symphony shares its name with + + align:start position:0% +powerful symphony shares its name with + + + align:start position:0% +powerful symphony shares its name with +Jupiter on Google if we search for mo + + align:start position:0% +Jupiter on Google if we search for mo + + + align:start position:0% +Jupiter on Google if we search for mo +symphonie and mercury we get about + + align:start position:0% +symphonie and mercury we get about + + + align:start position:0% +symphonie and mercury we get about +900,000 results and we get some good + + align:start position:0% +900,000 results and we get some good + + + align:start position:0% +900,000 results and we get some good +results + + align:start position:0% +results + + + align:start position:0% +results +they definitely mention the three words + + align:start position:0% +they definitely mention the three words + + + align:start position:0% +they definitely mention the three words +we searched for but mercury is only next + + align:start position:0% +we searched for but mercury is only next + + + align:start position:0% +we searched for but mercury is only next +to symphony once and there's no mention + + align:start position:0% +to symphony once and there's no mention + + + align:start position:0% +to symphony once and there's no mention +about this being his last symphony now + + align:start position:0% +about this being his last symphony now + + + align:start position:0% +about this being his last symphony now +if we search for Mozart Symphony and + + align:start position:0% +if we search for Mozart Symphony and + + + align:start position:0% +if we search for Mozart Symphony and +Jupiter we get about 1.5 million results + + align:start position:0% +Jupiter we get about 1.5 million results + + + align:start position:0% +Jupiter we get about 1.5 million results +and they look much more promising we see + + align:start position:0% +and they look much more promising we see + + + align:start position:0% +and they look much more promising we see +the phrase last Symphony a couple times + + align:start position:0% +the phrase last Symphony a couple times + + + align:start position:0% +the phrase last Symphony a couple times +and Jupiter symphony more than once + + align:start position:0% +and Jupiter symphony more than once + + + align:start position:0% +and Jupiter symphony more than once +therefore the hypothesis with Jupiter + + align:start position:0% +therefore the hypothesis with Jupiter + + + align:start position:0% +therefore the hypothesis with Jupiter +seems to be more supported than the + + align:start position:0% +seems to be more supported than the + + + align:start position:0% +seems to be more supported than the +hypothesis with Mercury now the scoring + + align:start position:0% +hypothesis with Mercury now the scoring + + + align:start position:0% +hypothesis with Mercury now the scoring +analytics determine the degree of + + align:start position:0% +analytics determine the degree of + + + align:start position:0% +analytics determine the degree of +certainty that the evidence supports the + + align:start position:0% +certainty that the evidence supports the + + + align:start position:0% +certainty that the evidence supports the +candidate answers more than 50 different + + align:start position:0% +candidate answers more than 50 different + + + align:start position:0% +candidate answers more than 50 different +scoring components are used one example + + align:start position:0% +scoring components are used one example + + + align:start position:0% +scoring components are used one example +is analyzing temporal relationships + + align:start position:0% +is analyzing temporal relationships + + + align:start position:0% +is analyzing temporal relationships +consider the Jeopardy question in 1594 + + align:start position:0% +consider the Jeopardy question in 1594 + + + align:start position:0% +consider the Jeopardy question in 1594 +he took a job as a tax collector in + + align:start position:0% +he took a job as a tax collector in + + + align:start position:0% +he took a job as a tax collector in +Andalusia two candidate answers are + + align:start position:0% +Andalusia two candidate answers are + + + align:start position:0% +Andalusia two candidate answers are +thorough and Cervantes + + align:start position:0% +thorough and Cervantes + + + align:start position:0% +thorough and Cervantes +however this algorithm would determine + + align:start position:0% +however this algorithm would determine + + + align:start position:0% +however this algorithm would determine +that Thoreau was not born until 1817 so + + align:start position:0% +that Thoreau was not born until 1817 so + + + align:start position:0% +that Thoreau was not born until 1817 so +it would give a higher score to + + align:start position:0% +it would give a higher score to + + + align:start position:0% +it would give a higher score to +Cervantes once all of the scoring + + align:start position:0% +Cervantes once all of the scoring + + + align:start position:0% +Cervantes once all of the scoring +algorithms are run Watson needs to + + align:start position:0% +algorithms are run Watson needs to + + + align:start position:0% +algorithms are run Watson needs to +select the single best supported + + align:start position:0% +select the single best supported + + + align:start position:0% +select the single best supported +hypothesis before this can be done + + align:start position:0% +hypothesis before this can be done + + + align:start position:0% +hypothesis before this can be done +similar answers need to be merged since + + align:start position:0% +similar answers need to be merged since + + + align:start position:0% +similar answers need to be merged since +multiple candidate answers may be + + align:start position:0% +multiple candidate answers may be + + + align:start position:0% +multiple candidate answers may be +equivalent as an example the candidate + + align:start position:0% +equivalent as an example the candidate + + + align:start position:0% +equivalent as an example the candidate +answers Abraham Lincoln and Honest Abe + + align:start position:0% +answers Abraham Lincoln and Honest Abe + + + align:start position:0% +answers Abraham Lincoln and Honest Abe +refer to the same person so the scores + + align:start position:0% +refer to the same person so the scores + + + align:start position:0% +refer to the same person so the scores +for these two candidate answers need to + + align:start position:0% +for these two candidate answers need to + + + align:start position:0% +for these two candidate answers need to +be combined + + align:start position:0% +be combined + + + align:start position:0% +be combined +Watson should not be viewing similar + + align:start position:0% +Watson should not be viewing similar + + + align:start position:0% +Watson should not be viewing similar +answers as competing choices now Watson + + align:start position:0% +answers as competing choices now Watson + + + align:start position:0% +answers as competing choices now Watson +is ready to rank the hypotheses and + + align:start position:0% +is ready to rank the hypotheses and + + + align:start position:0% +is ready to rank the hypotheses and +estimate an overall confidence for each + + align:start position:0% +estimate an overall confidence for each + + + align:start position:0% +estimate an overall confidence for each +to do this predictive analytics are used + + align:start position:0% +to do this predictive analytics are used + + + align:start position:0% +to do this predictive analytics are used +to compute an overall confidence level + + align:start position:0% +to compute an overall confidence level + + + align:start position:0% +to compute an overall confidence level +for each candidate answer Watson uses + + align:start position:0% +for each candidate answer Watson uses + + + align:start position:0% +for each candidate answer Watson uses +logistic regression the training data is + + align:start position:0% +logistic regression the training data is + + + align:start position:0% +logistic regression the training data is +a set of historical jeopardy questions + + align:start position:0% +a set of historical jeopardy questions + + + align:start position:0% +a set of historical jeopardy questions +and all of the candidate answers each of + + align:start position:0% +and all of the candidate answers each of + + + align:start position:0% +and all of the candidate answers each of +the scoring algorithms is used as an + + align:start position:0% +the scoring algorithms is used as an + + + align:start position:0% +the scoring algorithms is used as an +independent variable then logistic + + align:start position:0% +independent variable then logistic + + + align:start position:0% +independent variable then logistic +regression is used to predict whether or + + align:start position:0% +regression is used to predict whether or + + + align:start position:0% +regression is used to predict whether or +not a candidate answer is correct + + align:start position:0% +not a candidate answer is correct + + + align:start position:0% +not a candidate answer is correct +using the scores this gives each score a + + align:start position:0% +using the scores this gives each score a + + + align:start position:0% +using the scores this gives each score a +weight and computes an overall + + align:start position:0% +weight and computes an overall + + + align:start position:0% +weight and computes an overall +probability or confidence that a + + align:start position:0% +probability or confidence that a + + + align:start position:0% +probability or confidence that a +candidate answer is correct + + align:start position:0% +candidate answer is correct + + + align:start position:0% +candidate answer is correct +it's the highest confidence level for + + align:start position:0% +it's the highest confidence level for + + + align:start position:0% +it's the highest confidence level for +one of the candidate answers for a + + align:start position:0% +one of the candidate answers for a + + + align:start position:0% +one of the candidate answers for a +question is high enough + + align:start position:0% +question is high enough + + + align:start position:0% +question is high enough +Watson buzzes in to answer the question + + align:start position:0% +Watson buzzes in to answer the question + + + align:start position:0% +Watson buzzes in to answer the question +in total the Watson system is composed + + align:start position:0% +in total the Watson system is composed + + + align:start position:0% +in total the Watson system is composed +of eight refrigerator-sized cabinets and + + align:start position:0% +of eight refrigerator-sized cabinets and + + + align:start position:0% +of eight refrigerator-sized cabinets and +has high speed local storage for all + + align:start position:0% +has high speed local storage for all + + + align:start position:0% +has high speed local storage for all +information it originally took over two + + align:start position:0% +information it originally took over two + + + align:start position:0% +information it originally took over two +hours to answer one question and the + + align:start position:0% +hours to answer one question and the + + + align:start position:0% +hours to answer one question and the +team had to reduce us to two to six + + align:start position:0% +team had to reduce us to two to six + + + align:start position:0% +team had to reduce us to two to six +seconds in the next video we'll see how + + align:start position:0% +seconds in the next video we'll see how + + + align:start position:0% +seconds in the next video we'll see how +Watson progressed in the six years + + align:start position:0% +Watson progressed in the six years + + + align:start position:0% +Watson progressed in the six years +between starting and plane on Jeopardy + + align:start position:0% +between starting and plane on Jeopardy + + + align:start position:0% +between starting and plane on Jeopardy +what happened during the game and what + + align:start position:0% +what happened during the game and what + + + align:start position:0% +what happened during the game and what +the Watson team is working on now \ No newline at end of file diff --git a/gDpkinitSRM.txt b/gDpkinitSRM.txt new file mode 100644 index 0000000000000000000000000000000000000000..cad6083b4997187f1eed00b26c41f8e3a3db33d8 --- /dev/null +++ b/gDpkinitSRM.txt @@ -0,0 +1,1131 @@ +align:start position:0% + +I'm uh I'm promoter I'm Gillian Gillian + + align:start position:0% +I'm uh I'm promoter I'm Gillian Gillian + + + align:start position:0% +I'm uh I'm promoter I'm Gillian Gillian +and um our game is you know like how on + + align:start position:0% +and um our game is you know like how on + + + align:start position:0% +and um our game is you know like how on +the iPhone you have those games that's + + align:start position:0% +the iPhone you have those games that's + + + align:start position:0% +the iPhone you have those games that's +like jetpack joyride or something it's + + align:start position:0% +like jetpack joyride or something it's + + + align:start position:0% +like jetpack joyride or something it's +like one of those games that has a + + align:start position:0% +like one of those games that has a + + + align:start position:0% +like one of those games that has a +player moving infinitely and you have to + + align:start position:0% +player moving infinitely and you have to + + + align:start position:0% +player moving infinitely and you have to +click to make a jump or go left or right + + align:start position:0% +click to make a jump or go left or right + + + align:start position:0% +click to make a jump or go left or right +so it's kind of based off of that that + + align:start position:0% +so it's kind of based off of that that + + + align:start position:0% +so it's kind of based off of that that +was kind of our inspiration except it's + + align:start position:0% +was kind of our inspiration except it's + + + align:start position:0% +was kind of our inspiration except it's +in 3d and well I guess just play it yeah + + align:start position:0% +in 3d and well I guess just play it yeah + + + align:start position:0% +in 3d and well I guess just play it yeah +he'll just demo it hopefully it'll play + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so the cube is moving instantly in the + + align:start position:0% +so the cube is moving instantly in the + + + align:start position:0% +so the cube is moving instantly in the +plane and you can collect coins and + + align:start position:0% +plane and you can collect coins and + + + align:start position:0% +plane and you can collect coins and +that'll make your score go up if you + + align:start position:0% +that'll make your score go up if you + + + align:start position:0% +that'll make your score go up if you +touch a cactus these are like enemies + + align:start position:0% +touch a cactus these are like enemies + + + align:start position:0% +touch a cactus these are like enemies +that'll destroy your lives you have you + + align:start position:0% +that'll destroy your lives you have you + + + align:start position:0% +that'll destroy your lives you have you +start off with five lives right what she + + align:start position:0% +start off with five lives right what she + + + align:start position:0% +start off with five lives right what she +just picked up is a capsule so you see + + align:start position:0% +just picked up is a capsule so you see + + + align:start position:0% +just picked up is a capsule so you see +the little bar at the bottom that's like + + align:start position:0% +the little bar at the bottom that's like + + + align:start position:0% +the little bar at the bottom that's like +how much fuel you have so that you can + + align:start position:0% +how much fuel you have so that you can + + + align:start position:0% +how much fuel you have so that you can +only fly which is hitting spacebar fly + + align:start position:0% +only fly which is hitting spacebar fly + + + align:start position:0% +only fly which is hitting spacebar fly +okay yeah yeah you can also go + + align:start position:0% +okay yeah yeah you can also go + + + align:start position:0% +okay yeah yeah you can also go +underwater so there's like coins under + + align:start position:0% +underwater so there's like coins under + + + align:start position:0% +underwater so there's like coins under +the water and so you like to go under + + align:start position:0% +the water and so you like to go under + + + align:start position:0% +the water and so you like to go under +there you can collect secret coins and + + align:start position:0% +there you can collect secret coins and + + + align:start position:0% +there you can collect secret coins and +then you you fly by pressing spacebar + + align:start position:0% +then you you fly by pressing spacebar + + + align:start position:0% +then you you fly by pressing spacebar +but if you see the bar down there if you + + align:start position:0% +but if you see the bar down there if you + + + align:start position:0% +but if you see the bar down there if you +run out of fuel you can't press you + + align:start position:0% +run out of fuel you can't press you + + + align:start position:0% +run out of fuel you can't press you +can't fly in the the field anymore and + + align:start position:0% +can't fly in the the field anymore and + + + align:start position:0% +can't fly in the the field anymore and +so you just keep going I think we + + align:start position:0% +so you just keep going I think we + + + align:start position:0% +so you just keep going I think we +touched the few cactus along the way + + align:start position:0% +touched the few cactus along the way + + + align:start position:0% +touched the few cactus along the way +yeah our lives are like he was alive by + + align:start position:0% +yeah our lives are like he was alive by + + + align:start position:0% +yeah our lives are like he was alive by +touching the enemies there's okay now + + align:start position:0% +touching the enemies there's okay now + + + align:start position:0% +touching the enemies there's okay now +you know she can fly okay so we have + + align:start position:0% +you know she can fly okay so we have + + + align:start position:0% +you know she can fly okay so we have +like three worlds so this is the desert + + align:start position:0% +like three worlds so this is the desert + + + align:start position:0% +like three worlds so this is the desert +world and then she's going into like the + + align:start position:0% +world and then she's going into like the + + + align:start position:0% +world and then she's going into like the +snow world which also has coins + + align:start position:0% +snow world which also has coins + + + align:start position:0% +snow world which also has coins +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +yeah it's it's pretty yeah and then + + align:start position:0% +yeah it's it's pretty yeah and then + + + align:start position:0% +yeah it's it's pretty yeah and then +obviously the coin spin around this + + align:start position:0% +obviously the coin spin around this + + + align:start position:0% +obviously the coin spin around this +world isn't as tall as long as the + + align:start position:0% +world isn't as tall as long as the + + + align:start position:0% +world isn't as tall as long as the +desert world you can see like the forest + + align:start position:0% +desert world you can see like the forest + + + align:start position:0% +desert world you can see like the forest +roll showing up already + + align:start position:0% +roll showing up already + + + align:start position:0% +roll showing up already +there's also coins in the air but you + + align:start position:0% +there's also coins in the air but you + + + align:start position:0% +there's also coins in the air but you +can only get them if you have fuel yeah + + align:start position:0% +can only get them if you have fuel yeah + + + align:start position:0% +can only get them if you have fuel yeah +you have to be like you have to know + + align:start position:0% +you have to be like you have to know + + + align:start position:0% +you have to be like you have to know +exactly where they are oh there you go I + + align:start position:0% +exactly where they are oh there you go I + + + align:start position:0% +exactly where they are oh there you go I +think our high score is 20 so if anyone + + align:start position:0% +think our high score is 20 so if anyone + + + align:start position:0% +think our high score is 20 so if anyone +can beat that yes so you can like run + + align:start position:0% +can beat that yes so you can like run + + + align:start position:0% +can beat that yes so you can like run +into them yeah you can submerge in the + + align:start position:0% +into them yeah you can submerge in the + + + align:start position:0% +into them yeah you can submerge in the +grass so it's like going through a + + align:start position:0% +grass so it's like going through a + + + align:start position:0% +grass so it's like going through a +meadow and it's funny because the grass + + align:start position:0% +meadow and it's funny because the grass + + + align:start position:0% +meadow and it's funny because the grass +is actually a bunch of little trees you + + align:start position:0% +is actually a bunch of little trees you + + + align:start position:0% +is actually a bunch of little trees you +can't see it now but if you like zoom in + + align:start position:0% +can't see it now but if you like zoom in + + + align:start position:0% +can't see it now but if you like zoom in +infinitely you'll see like the tiny + + align:start position:0% +infinitely you'll see like the tiny + + + align:start position:0% +infinitely you'll see like the tiny +little trees swaying it's really funny + + align:start position:0% +little trees swaying it's really funny + + + align:start position:0% +little trees swaying it's really funny +yeah and then yeah that is the end of + + align:start position:0% +yeah and then yeah that is the end of + + + align:start position:0% +yeah and then yeah that is the end of +the game and then I think you'll fall + + align:start position:0% +the game and then I think you'll fall + + + align:start position:0% +the game and then I think you'll fall +infinitely yeah yeah you just fall + + align:start position:0% +infinitely yeah yeah you just fall + + + align:start position:0% +infinitely yeah yeah you just fall +infinitely into space that's our game so + + align:start position:0% +infinitely into space that's our game so + + + align:start position:0% +infinitely into space that's our game so +we can talk about like some challenges + + align:start position:0% +we can talk about like some challenges + + + align:start position:0% +we can talk about like some challenges +that we had um so basically split up the + + align:start position:0% +that we had um so basically split up the + + + align:start position:0% +that we had um so basically split up the +work into two separate groups so um so I + + align:start position:0% +work into two separate groups so um so I + + + align:start position:0% +work into two separate groups so um so I +mostly worked on building the world + + align:start position:0% +mostly worked on building the world + + + align:start position:0% +mostly worked on building the world +because I found like the terraforming + + align:start position:0% +because I found like the terraforming + + + align:start position:0% +because I found like the terraforming +tool of unity like fascinating I spent + + align:start position:0% +tool of unity like fascinating I spent + + + align:start position:0% +tool of unity like fascinating I spent +like hours doing that it's so cool so a + + align:start position:0% +like hours doing that it's so cool so a + + + align:start position:0% +like hours doing that it's so cool so a +lot of the more complicated things like + + align:start position:0% +lot of the more complicated things like + + + align:start position:0% +lot of the more complicated things like +you can see the canyons and the cactus + + align:start position:0% +you can see the canyons and the cactus + + + align:start position:0% +you can see the canyons and the cactus +were and the trees were imported from + + align:start position:0% +were and the trees were imported from + + + align:start position:0% +were and the trees were imported from +Unity assets um all of them were free + + align:start position:0% +Unity assets um all of them were free + + + align:start position:0% +Unity assets um all of them were free +although there are some that are like up + + align:start position:0% +although there are some that are like up + + + align:start position:0% +although there are some that are like up +to like $40 and basically the ground the + + align:start position:0% +to like $40 and basically the ground the + + + align:start position:0% +to like $40 and basically the ground the +terrain I like hand created but the + + align:start position:0% +terrain I like hand created but the + + + align:start position:0% +terrain I like hand created but the +canyons and cacti were created and + + align:start position:0% +canyons and cacti were created and + + + align:start position:0% +canyons and cacti were created and +imported but I did hand place all of + + align:start position:0% +imported but I did hand place all of + + + align:start position:0% +imported but I did hand place all of +them in the hand design + + align:start position:0% +them in the hand design + + + align:start position:0% +them in the hand design +that the river let's see if I can like + + align:start position:0% +that the river let's see if I can like + + + align:start position:0% +that the river let's see if I can like +zoom in um the river it was interesting + + align:start position:0% +zoom in um the river it was interesting + + + align:start position:0% +zoom in um the river it was interesting +to create because um it's not that hard + + align:start position:0% +to create because um it's not that hard + + + align:start position:0% +to create because um it's not that hard +unity makes it relatively easy for you + + align:start position:0% +unity makes it relatively easy for you + + + align:start position:0% +unity makes it relatively easy for you +but to get it to have like the applied + + align:start position:0% +but to get it to have like the applied + + + align:start position:0% +but to get it to have like the applied +the physics to the river properly is + + align:start position:0% +the physics to the river properly is + + + align:start position:0% +the physics to the river properly is +like kind of complicated you can't + + align:start position:0% +like kind of complicated you can't + + + align:start position:0% +like kind of complicated you can't +really tell because of the way we have + + align:start position:0% +really tell because of the way we have + + + align:start position:0% +really tell because of the way we have +it but there's actually water everywhere + + align:start position:0% +it but there's actually water everywhere + + + align:start position:0% +it but there's actually water everywhere +in this world and if you dig deep enough + + align:start position:0% +in this world and if you dig deep enough + + + align:start position:0% +in this world and if you dig deep enough +you will get a pool so I can show you + + align:start position:0% +you will get a pool so I can show you + + + align:start position:0% +you will get a pool so I can show you +that so let's see inspector this is how + + align:start position:0% +that so let's see inspector this is how + + + align:start position:0% +that so let's see inspector this is how +you do the terrain here + + align:start position:0% + + + + align:start position:0% + +concealing water coming up and then she + + align:start position:0% +concealing water coming up and then she + + + align:start position:0% +concealing water coming up and then she +worked on the coding parts as far as the + + align:start position:0% +worked on the coding parts as far as the + + + align:start position:0% +worked on the coding parts as far as the +game address yeah I did mostly the code + + align:start position:0% +game address yeah I did mostly the code + + + align:start position:0% +game address yeah I did mostly the code +and there's not really that many + + align:start position:0% +and there's not really that many + + + align:start position:0% +and there's not really that many +different codes I don't know if you can + + align:start position:0% +different codes I don't know if you can + + + align:start position:0% +different codes I don't know if you can +wear the scripts right so there's + + align:start position:0% +wear the scripts right so there's + + + align:start position:0% +wear the scripts right so there's +there's really only a few simple codes + + align:start position:0% +there's really only a few simple codes + + + align:start position:0% +there's really only a few simple codes +over there but like so the coins they + + align:start position:0% +over there but like so the coins they + + + align:start position:0% +over there but like so the coins they +have their own little code so that they + + align:start position:0% +have their own little code so that they + + + align:start position:0% +have their own little code so that they +spin around which yeah that's that's the + + align:start position:0% +spin around which yeah that's that's the + + + align:start position:0% +spin around which yeah that's that's the +code for the player right and so just a + + align:start position:0% +code for the player right and so just a + + + align:start position:0% +code for the player right and so just a +player so like the the weirdest part was + + align:start position:0% +player so like the the weirdest part was + + + align:start position:0% +player so like the the weirdest part was +to get the cube to always move + + align:start position:0% +to get the cube to always move + + + align:start position:0% +to get the cube to always move +infinitely so like you know originally + + align:start position:0% +infinitely so like you know originally + + + align:start position:0% +infinitely so like you know originally +you could move it forward and backwards + + align:start position:0% +you could move it forward and backwards + + + align:start position:0% +you could move it forward and backwards +but we just have to figure out how to + + align:start position:0% +but we just have to figure out how to + + + align:start position:0% +but we just have to figure out how to +like make it so it never moves backwards + + align:start position:0% +like make it so it never moves backwards + + + align:start position:0% +like make it so it never moves backwards +like that's not an option and so that + + align:start position:0% +like that's not an option and so that + + + align:start position:0% +like that's not an option and so that +was that was just something different + + align:start position:0% +was that was just something different + + + align:start position:0% +was that was just something different +that I had to figure out how to do and + + align:start position:0% +that I had to figure out how to do and + + + align:start position:0% +that I had to figure out how to do and +then this is just like a bunch of + + align:start position:0% +then this is just like a bunch of + + + align:start position:0% +then this is just like a bunch of +different codes actually the hardest + + align:start position:0% +different codes actually the hardest + + + align:start position:0% +different codes actually the hardest +part I think was doing the health bar to + + align:start position:0% +part I think was doing the health bar to + + + align:start position:0% +part I think was doing the health bar to +make it go down so I mean obviously you + + align:start position:0% +make it go down so I mean obviously you + + + align:start position:0% +make it go down so I mean obviously you +can like make integers go down but like + + align:start position:0% +can like make integers go down but like + + + align:start position:0% +can like make integers go down but like +just make that visually happen was + + align:start position:0% +just make that visually happen was + + + align:start position:0% +just make that visually happen was +really weird but that you just have to + + align:start position:0% +really weird but that you just have to + + + align:start position:0% +really weird but that you just have to +like use a local scale or something like + + align:start position:0% +like use a local scale or something like + + + align:start position:0% +like use a local scale or something like +that and so that was that was pretty + + align:start position:0% +that and so that was that was pretty + + + align:start position:0% +that and so that was that was pretty +simple after I figured it out I guess + + align:start position:0% +simple after I figured it out I guess + + + align:start position:0% +simple after I figured it out I guess +but in the process of this heart and + + align:start position:0% +but in the process of this heart and + + + align:start position:0% +but in the process of this heart and +overall the game was really fun to make + + align:start position:0% +overall the game was really fun to make + + + align:start position:0% +overall the game was really fun to make +yeah you actually like worked on it a + + align:start position:0% +yeah you actually like worked on it a + + + align:start position:0% +yeah you actually like worked on it a +lot and like on our own time after class + + align:start position:0% +lot and like on our own time after class + + + align:start position:0% +lot and like on our own time after class +she was here till like 11:00 last night + + align:start position:0% +she was here till like 11:00 last night + + + align:start position:0% +she was here till like 11:00 last night +at my dorm room + + align:start position:0% +at my dorm room + + + align:start position:0% +at my dorm room +because I were just like yeah it was + + align:start position:0% +because I were just like yeah it was + + + align:start position:0% +because I were just like yeah it was +like made me like 30% done until last + + align:start position:0% +like made me like 30% done until last + + + align:start position:0% +like made me like 30% done until last +and it really came together last night + + align:start position:0% +and it really came together last night + + + align:start position:0% +and it really came together last night +and then we were like what could be + + align:start position:0% +and then we were like what could be + + + align:start position:0% +and then we were like what could be +adding more I think we just kept on + + align:start position:0% +adding more I think we just kept on + + + align:start position:0% +adding more I think we just kept on +going in and ass every time we were like + + align:start position:0% +going in and ass every time we were like + + + align:start position:0% +going in and ass every time we were like +we should stop yeah like this is enough + + align:start position:0% +we should stop yeah like this is enough + + + align:start position:0% +we should stop yeah like this is enough +so yeah that's about it yeah that's all + + align:start position:0% +so yeah that's about it yeah that's all + + + align:start position:0% +so yeah that's about it yeah that's all +you have says spacebar to jump but unlit + + align:start position:0% +you have says spacebar to jump but unlit + + + align:start position:0% +you have says spacebar to jump but unlit +until you run out of fuel at which point + + align:start position:0% +until you run out of fuel at which point + + + align:start position:0% +until you run out of fuel at which point +it like locks the spacebar so you can't + + align:start position:0% +it like locks the spacebar so you can't + + + align:start position:0% +it like locks the spacebar so you can't +you can't go up that good yeah yeah you + + align:start position:0% +you can't go up that good yeah yeah you + + + align:start position:0% +you can't go up that good yeah yeah you +like continuous every time you hit the + + align:start position:0% +like continuous every time you hit the + + + align:start position:0% +like continuous every time you hit the +spacebar so you can go every way so you + + align:start position:0% +spacebar so you can go every way so you + + + align:start position:0% +spacebar so you can go every way so you +like continue to fly \ No newline at end of file diff --git a/gE1wRDQMR8E.txt b/gE1wRDQMR8E.txt new file mode 100644 index 0000000000000000000000000000000000000000..6e9827e14737c37545b1ed440f62eca1dd3c9df9 --- /dev/null +++ b/gE1wRDQMR8E.txt @@ -0,0 +1,1195 @@ +align:start position:0% + +in the previous video we observed that + + align:start position:0% +in the previous video we observed that + + + align:start position:0% +in the previous video we observed that +age and France population are highly + + align:start position:0% +age and France population are highly + + + align:start position:0% +age and France population are highly +correlated but what is correlation + + align:start position:0% +correlated but what is correlation + + + align:start position:0% +correlated but what is correlation +correlation measures the linear + + align:start position:0% +correlation measures the linear + + + align:start position:0% +correlation measures the linear +relationship between two variables and + + align:start position:0% +relationship between two variables and + + + align:start position:0% +relationship between two variables and +is a number between negative 1 and + + align:start position:0% +is a number between negative 1 and + + + align:start position:0% +is a number between negative 1 and +positive 1 a correlation of positive 1 + + align:start position:0% +positive 1 a correlation of positive 1 + + + align:start position:0% +positive 1 a correlation of positive 1 +means a perfect positive linear + + align:start position:0% +means a perfect positive linear + + + align:start position:0% +means a perfect positive linear +relationship a correlation of negative 1 + + align:start position:0% +relationship a correlation of negative 1 + + + align:start position:0% +relationship a correlation of negative 1 +means a perfect negative linear + + align:start position:0% +means a perfect negative linear + + + align:start position:0% +means a perfect negative linear +relationship in the middle of these two + + align:start position:0% +relationship in the middle of these two + + + align:start position:0% +relationship in the middle of these two +extremes is a correlation of 0 which + + align:start position:0% +extremes is a correlation of 0 which + + + align:start position:0% +extremes is a correlation of 0 which +means that there is no linear + + align:start position:0% +means that there is no linear + + + align:start position:0% +means that there is no linear +relationship between the two variables + + align:start position:0% +relationship between the two variables + + + align:start position:0% +relationship between the two variables +when we say that two variables are + + align:start position:0% +when we say that two variables are + + + align:start position:0% +when we say that two variables are +highly correlated we mean that the + + align:start position:0% +highly correlated we mean that the + + + align:start position:0% +highly correlated we mean that the +absolute value of the correlation is + + align:start position:0% +absolute value of the correlation is + + + align:start position:0% +absolute value of the correlation is +close to 1 let's look at some examples + + align:start position:0% +close to 1 let's look at some examples + + + align:start position:0% +close to 1 let's look at some examples +this plot graphs winter reign on the + + align:start position:0% +this plot graphs winter reign on the + + + align:start position:0% +this plot graphs winter reign on the +x-axis and price on the y-axis by + + align:start position:0% +x-axis and price on the y-axis by + + + align:start position:0% +x-axis and price on the y-axis by +visually inspecting the plot it's hard + + align:start position:0% +visually inspecting the plot it's hard + + + align:start position:0% +visually inspecting the plot it's hard +to detect any linear relationship but it + + align:start position:0% +to detect any linear relationship but it + + + align:start position:0% +to detect any linear relationship but it +turns out that the correlation between + + align:start position:0% +turns out that the correlation between + + + align:start position:0% +turns out that the correlation between +winter rain and price is 0.14 so there's + + align:start position:0% +winter rain and price is 0.14 so there's + + + align:start position:0% +winter rain and price is 0.14 so there's +a slight positive relationship between + + align:start position:0% +a slight positive relationship between + + + align:start position:0% +a slight positive relationship between +these two variables + + align:start position:0% + + + + align:start position:0% + +this plot has harvest strain on the + + align:start position:0% +this plot has harvest strain on the + + + align:start position:0% +this plot has harvest strain on the +x-axis and the average growing season + + align:start position:0% +x-axis and the average growing season + + + align:start position:0% +x-axis and the average growing season +temperature on the y-axis it's again + + align:start position:0% +temperature on the y-axis it's again + + + align:start position:0% +temperature on the y-axis it's again +hard to visually see a linear + + align:start position:0% +hard to visually see a linear + + + align:start position:0% +hard to visually see a linear +relationship between the two variables + + align:start position:0% +relationship between the two variables + + + align:start position:0% +relationship between the two variables +and it turns out that the correlation is + + align:start position:0% +and it turns out that the correlation is + + + align:start position:0% +and it turns out that the correlation is +negative 0.06 + + align:start position:0% +negative 0.06 + + + align:start position:0% +negative 0.06 +even closer to 0 than before this plot + + align:start position:0% +even closer to 0 than before this plot + + + align:start position:0% +even closer to 0 than before this plot +shows age of the wine on the x-axis and + + align:start position:0% +shows age of the wine on the x-axis and + + + align:start position:0% +shows age of the wine on the x-axis and +the population of France on the y-axis + + align:start position:0% +the population of France on the y-axis + + + align:start position:0% +the population of France on the y-axis +we can easily see that there's a strong + + align:start position:0% +we can easily see that there's a strong + + + align:start position:0% +we can easily see that there's a strong +negative linear relationship between + + align:start position:0% +negative linear relationship between + + + align:start position:0% +negative linear relationship between +these two variables this makes sense + + align:start position:0% +these two variables this makes sense + + + align:start position:0% +these two variables this makes sense +since the population of France is + + align:start position:0% +since the population of France is + + + align:start position:0% +since the population of France is +increased with time if we compute the + + align:start position:0% +increased with time if we compute the + + + align:start position:0% +increased with time if we compute the +correlation we get negative 0.99 so + + align:start position:0% +correlation we get negative 0.99 so + + + align:start position:0% +correlation we get negative 0.99 so +these two variables are indeed highly + + align:start position:0% +these two variables are indeed highly + + + align:start position:0% +these two variables are indeed highly +correlated let's compute some + + align:start position:0% +correlated let's compute some + + + align:start position:0% +correlated let's compute some +correlations in R we can compute the + + align:start position:0% +correlations in R we can compute the + + + align:start position:0% +correlations in R we can compute the +correlation between a pair of air + + align:start position:0% +correlation between a pair of air + + + align:start position:0% +correlation between a pair of air +balls and our by using the COR function + + align:start position:0% +balls and our by using the COR function + + + align:start position:0% +balls and our by using the COR function +let's compute the correlation between + + align:start position:0% +let's compute the correlation between + + + align:start position:0% +let's compute the correlation between +winter rain and price so we type cor and + + align:start position:0% +winter rain and price so we type cor and + + + align:start position:0% +winter rain and price so we type cor and +then in parentheses we give the names of + + align:start position:0% +then in parentheses we give the names of + + + align:start position:0% +then in parentheses we give the names of +the two variables winter rain and price + + align:start position:0% +the two variables winter rain and price + + + align:start position:0% +the two variables winter rain and price +if we hit enter this function tells us + + align:start position:0% +if we hit enter this function tells us + + + align:start position:0% +if we hit enter this function tells us +that the correlation between the two + + align:start position:0% +that the correlation between the two + + + align:start position:0% +that the correlation between the two +variables is 0.137 + + align:start position:0% +variables is 0.137 + + + align:start position:0% +variables is 0.137 +let's look at another example this time + + align:start position:0% +let's look at another example this time + + + align:start position:0% +let's look at another example this time +we'll compute the correlation between + + align:start position:0% +we'll compute the correlation between + + + align:start position:0% +we'll compute the correlation between +age and France population so again we + + align:start position:0% +age and France population so again we + + + align:start position:0% +age and France population so again we +use the COR function but this time we + + align:start position:0% +use the COR function but this time we + + + align:start position:0% +use the COR function but this time we +give us the two variables age and France + + align:start position:0% +give us the two variables age and France + + + align:start position:0% +give us the two variables age and France +population as we saw earlier age and + + align:start position:0% +population as we saw earlier age and + + + align:start position:0% +population as we saw earlier age and +France population are highly correlated + + align:start position:0% +France population are highly correlated + + + align:start position:0% +France population are highly correlated +with the correlation of negative 0.99 we + + align:start position:0% +with the correlation of negative 0.99 we + + + align:start position:0% +with the correlation of negative 0.99 we +can also compute the correlation between + + align:start position:0% +can also compute the correlation between + + + align:start position:0% +can also compute the correlation between +all pairs of variables in our dataset + + align:start position:0% +all pairs of variables in our dataset + + + align:start position:0% +all pairs of variables in our dataset +using the core function to do so we just + + align:start position:0% +using the core function to do so we just + + + align:start position:0% +using the core function to do so we just +type cor and then our dataset name wine + + align:start position:0% +type cor and then our dataset name wine + + + align:start position:0% +type cor and then our dataset name wine +the output is a grid of numbers with the + + align:start position:0% +the output is a grid of numbers with the + + + align:start position:0% +the output is a grid of numbers with the +rows and columns labeled with the + + align:start position:0% +rows and columns labeled with the + + + align:start position:0% +rows and columns labeled with the +variables in our data set to find the + + align:start position:0% +variables in our data set to find the + + + align:start position:0% +variables in our data set to find the +correlation between two variables you + + align:start position:0% +correlation between two variables you + + + align:start position:0% +correlation between two variables you +just need to find the row for one of + + align:start position:0% +just need to find the row for one of + + + align:start position:0% +just need to find the row for one of +them and the column for the other for + + align:start position:0% +them and the column for the other for + + + align:start position:0% +them and the column for the other for +example we can find the column for age + + align:start position:0% +example we can find the column for age + + + align:start position:0% +example we can find the column for age +and then go down to the row for France + + align:start position:0% +and then go down to the row for France + + + align:start position:0% +and then go down to the row for France +population to see the number that we + + align:start position:0% +population to see the number that we + + + align:start position:0% +population to see the number that we +just computed or we could check if + + align:start position:0% +just computed or we could check if + + + align:start position:0% +just computed or we could check if +winter rain is highly correlated with + + align:start position:0% +winter rain is highly correlated with + + + align:start position:0% +winter rain is highly correlated with +any other independent variables by + + align:start position:0% +any other independent variables by + + + align:start position:0% +any other independent variables by +looking at the winter rain column so how + + align:start position:0% +looking at the winter rain column so how + + + align:start position:0% +looking at the winter rain column so how +does this information help us understand + + align:start position:0% +does this information help us understand + + + align:start position:0% +does this information help us understand +our linear regression model we've + + align:start position:0% +our linear regression model we've + + + align:start position:0% +our linear regression model we've +confirmed that age and France population + + align:start position:0% +confirmed that age and France population + + + align:start position:0% +confirmed that age and France population +are definitely highly correlated so we + + align:start position:0% +are definitely highly correlated so we + + + align:start position:0% +are definitely highly correlated so we +do have multicollinearity problems that + + align:start position:0% +do have multicollinearity problems that + + + align:start position:0% +do have multicollinearity problems that +our model that uses all of the available + + align:start position:0% +our model that uses all of the available + + + align:start position:0% +our model that uses all of the available +independent variables keep in mind that + + align:start position:0% +independent variables keep in mind that + + + align:start position:0% +independent variables keep in mind that +multicollinearity refers to the + + align:start position:0% +multicollinearity refers to the + + + align:start position:0% +multicollinearity refers to the +situation when two independent variables + + align:start position:0% +situation when two independent variables + + + align:start position:0% +situation when two independent variables +are highly correlated a high correlation + + align:start position:0% +are highly correlated a high correlation + + + align:start position:0% +are highly correlated a high correlation +between + + align:start position:0% +between + + + align:start position:0% +between +independent variable and the dependent + + align:start position:0% +independent variable and the dependent + + + align:start position:0% +independent variable and the dependent +variable is a good thing since we're + + align:start position:0% +variable is a good thing since we're + + + align:start position:0% +variable is a good thing since we're +trying to predict the dependent variable + + align:start position:0% +trying to predict the dependent variable + + + align:start position:0% +trying to predict the dependent variable +using the independent variables now due + + align:start position:0% +using the independent variables now due + + + align:start position:0% +using the independent variables now due +to the possibility of multicollinearity + + align:start position:0% +to the possibility of multicollinearity + + + align:start position:0% +to the possibility of multicollinearity +you always want to remove the + + align:start position:0% +you always want to remove the + + + align:start position:0% +you always want to remove the +insignificant variables one at a time + + align:start position:0% +insignificant variables one at a time + + + align:start position:0% +insignificant variables one at a time +let's see what would have happened if we + + align:start position:0% +let's see what would have happened if we + + + align:start position:0% +let's see what would have happened if we +had removed both the age and France + + align:start position:0% +had removed both the age and France + + + align:start position:0% +had removed both the age and France +population since they were both + + align:start position:0% +population since they were both + + + align:start position:0% +population since they were both +insignificant in our model that used all + + align:start position:0% +insignificant in our model that used all + + + align:start position:0% +insignificant in our model that used all +of the independent variables we'll call + + align:start position:0% +of the independent variables we'll call + + + align:start position:0% +of the independent variables we'll call +this new model model five and again + + align:start position:0% +this new model model five and again + + + align:start position:0% +this new model model five and again +we'll use the LM function to predict + + align:start position:0% +we'll use the LM function to predict + + + align:start position:0% +we'll use the LM function to predict +price using as independent variables + + align:start position:0% +price using as independent variables + + + align:start position:0% +price using as independent variables +average growing season temperature + + align:start position:0% +average growing season temperature + + + align:start position:0% +average growing season temperature +harvest rain and winter rain again we'll + + align:start position:0% +harvest rain and winter rain again we'll + + + align:start position:0% +harvest rain and winter rain again we'll +use the data set wine if we take a look + + align:start position:0% +use the data set wine if we take a look + + + align:start position:0% +use the data set wine if we take a look +at the summary of this new model and + + align:start position:0% +at the summary of this new model and + + + align:start position:0% +at the summary of this new model and +look at the coefficients table we can + + align:start position:0% +look at the coefficients table we can + + + align:start position:0% +look at the coefficients table we can +see that average growing season + + align:start position:0% +see that average growing season + + + align:start position:0% +see that average growing season +temperature and harvest rain are very + + align:start position:0% +temperature and harvest rain are very + + + align:start position:0% +temperature and harvest rain are very +significant and winter rain is almost + + align:start position:0% +significant and winter rain is almost + + + align:start position:0% +significant and winter rain is almost +significant so this model looks pretty + + align:start position:0% +significant so this model looks pretty + + + align:start position:0% +significant so this model looks pretty +good but if we look at our r-squared we + + align:start position:0% +good but if we look at our r-squared we + + + align:start position:0% +good but if we look at our r-squared we +can see that it dropped 2.75 the model + + align:start position:0% +can see that it dropped 2.75 the model + + + align:start position:0% +can see that it dropped 2.75 the model +that includes age has an r-squared of + + align:start position:0% +that includes age has an r-squared of + + + align:start position:0% +that includes age has an r-squared of +0.8 III so if we had removed age in + + align:start position:0% +0.8 III so if we had removed age in + + + align:start position:0% +0.8 III so if we had removed age in +France population at the same time we + + align:start position:0% +France population at the same time we + + + align:start position:0% +France population at the same time we +would have missed a significant variable + + align:start position:0% +would have missed a significant variable + + + align:start position:0% +would have missed a significant variable +and the r-squared of our final model + + align:start position:0% +and the r-squared of our final model + + + align:start position:0% +and the r-squared of our final model +would have been lower so why didn't we + + align:start position:0% +would have been lower so why didn't we + + + align:start position:0% +would have been lower so why didn't we +keep France population instead of age + + align:start position:0% +keep France population instead of age + + + align:start position:0% +keep France population instead of age +well we expect age to be significant + + align:start position:0% +well we expect age to be significant + + + align:start position:0% +well we expect age to be significant +older wines are typically more expensive + + align:start position:0% +older wines are typically more expensive + + + align:start position:0% +older wines are typically more expensive +so age makes more intuitive sense in our + + align:start position:0% +so age makes more intuitive sense in our + + + align:start position:0% +so age makes more intuitive sense in our +model multicollinearity reminds us that + + align:start position:0% +model multicollinearity reminds us that + + + align:start position:0% +model multicollinearity reminds us that +coefficients are only interpretable in + + align:start position:0% +coefficients are only interpretable in + + + align:start position:0% +coefficients are only interpretable in +the presence of other variables being + + align:start position:0% +the presence of other variables being + + + align:start position:0% +the presence of other variables being +used high correlations can even cause + + align:start position:0% +used high correlations can even cause + + + align:start position:0% +used high correlations can even cause +coefficients to have an unintuitive sign + + align:start position:0% +coefficients to have an unintuitive sign + + + align:start position:0% +coefficients to have an unintuitive sign +we'll see an example of this in the next + + align:start position:0% +we'll see an example of this in the next + + + align:start position:0% +we'll see an example of this in the next +lecture so we fix the multicollinearity + + align:start position:0% +lecture so we fix the multicollinearity + + + align:start position:0% +lecture so we fix the multicollinearity +issue caused by + + align:start position:0% +issue caused by + + + align:start position:0% +issue caused by +age and France population do we have any + + align:start position:0% +age and France population do we have any + + + align:start position:0% +age and France population do we have any +other highly correlated independent + + align:start position:0% +other highly correlated independent + + + align:start position:0% +other highly correlated independent +variables there is no definitive cutoff + + align:start position:0% +variables there is no definitive cutoff + + + align:start position:0% +variables there is no definitive cutoff +value for what makes a correlation too + + align:start position:0% +value for what makes a correlation too + + + align:start position:0% +value for what makes a correlation too +high but typically a correlation greater + + align:start position:0% +high but typically a correlation greater + + + align:start position:0% +high but typically a correlation greater +than 0.7 or less than negative 0.7 is + + align:start position:0% +than 0.7 or less than negative 0.7 is + + + align:start position:0% +than 0.7 or less than negative 0.7 is +cause for concern if you look back at + + align:start position:0% +cause for concern if you look back at + + + align:start position:0% +cause for concern if you look back at +all of the correlations we computed for + + align:start position:0% +all of the correlations we computed for + + + align:start position:0% +all of the correlations we computed for +our dataset you can see that it doesn't + + align:start position:0% +our dataset you can see that it doesn't + + + align:start position:0% +our dataset you can see that it doesn't +look like we have any other highly + + align:start position:0% +look like we have any other highly + + + align:start position:0% +look like we have any other highly +correlated independent variables so + + align:start position:0% +correlated independent variables so + + + align:start position:0% +correlated independent variables so +we'll stick with model for for the rest + + align:start position:0% +we'll stick with model for for the rest + + + align:start position:0% +we'll stick with model for for the rest +of this lecture the model that uses + + align:start position:0% +of this lecture the model that uses + + + align:start position:0% +of this lecture the model that uses +average growing season temperature + + align:start position:0% +average growing season temperature + + + align:start position:0% +average growing season temperature +harvest rain winter rain and age as the + + align:start position:0% +harvest rain winter rain and age as the + + + align:start position:0% +harvest rain winter rain and age as the +independent variables \ No newline at end of file diff --git a/gLnCmUkgUQk.txt b/gLnCmUkgUQk.txt new file mode 100644 index 0000000000000000000000000000000000000000..efb66e4733fbf4b054748b6ed78ba24677844254 --- /dev/null +++ b/gLnCmUkgUQk.txt @@ -0,0 +1,14050 @@ +align:start position:0% + +all right let's begin today's lecture so + + align:start position:0% +all right let's begin today's lecture so + + + align:start position:0% +all right let's begin today's lecture so +last class we began our adventure with + + align:start position:0% +last class we began our adventure with + + + align:start position:0% +last class we began our adventure with +creating our own data types today we're + + align:start position:0% +creating our own data types today we're + + + align:start position:0% +creating our own data types today we're +going to start off with a little bit of + + align:start position:0% +going to start off with a little bit of + + + align:start position:0% +going to start off with a little bit of +a recap just to remind you um some of + + align:start position:0% +a recap just to remind you um some of + + + align:start position:0% +a recap just to remind you um some of +the details about creating our own data + + align:start position:0% +the details about creating our own data + + + align:start position:0% +the details about creating our own data +types and then going to build upon that + + align:start position:0% +types and then going to build upon that + + + align:start position:0% +types and then going to build upon that +uh coordinate class we started in last + + align:start position:0% +uh coordinate class we started in last + + + align:start position:0% +uh coordinate class we started in last +class we'll build uh we'll build a + + align:start position:0% +class we'll build uh we'll build a + + + align:start position:0% +class we'll build uh we'll build a +circle class and then we'll build some + + align:start position:0% +circle class and then we'll build some + + + align:start position:0% +circle class and then we'll build some +fraction data types all right so the + + align:start position:0% +fraction data types all right so the + + + align:start position:0% +fraction data types all right so the +first thing I'd like to mention is to uh + + align:start position:0% +first thing I'd like to mention is to uh + + + align:start position:0% +first thing I'd like to mention is to uh +remind you guys about sort of um writing + + align:start position:0% +remind you guys about sort of um writing + + + align:start position:0% +remind you guys about sort of um writing +code from these two different + + align:start position:0% +code from these two different + + + align:start position:0% +code from these two different +perspectives right so just like when we + + align:start position:0% +perspectives right so just like when we + + + align:start position:0% +perspectives right so just like when we +wrote uh uh functions we were kind of + + align:start position:0% +wrote uh uh functions we were kind of + + + align:start position:0% +wrote uh uh functions we were kind of +writing the definition of the function + + align:start position:0% +writing the definition of the function + + + align:start position:0% +writing the definition of the function +telling python we have this function + + align:start position:0% +telling python we have this function + + + align:start position:0% +telling python we have this function +that we're defining abstractly and this + + align:start position:0% +that we're defining abstractly and this + + + align:start position:0% +that we're defining abstractly and this +is what it does and then we were calling + + align:start position:0% +is what it does and then we were calling + + + align:start position:0% +is what it does and then we were calling +the function later on in the program + + align:start position:0% +the function later on in the program + + + align:start position:0% +the function later on in the program +many many times well the same thing + + align:start position:0% +many many times well the same thing + + + align:start position:0% +many many times well the same thing +exists uh the same idea exists now that + + align:start position:0% +exists uh the same idea exists now that + + + align:start position:0% +exists uh the same idea exists now that +we're creating creating our own data + + align:start position:0% +we're creating creating our own data + + + align:start position:0% +we're creating creating our own data +types we have to write code from the + + align:start position:0% +types we have to write code from the + + + align:start position:0% +types we have to write code from the +point of view of somebody who's + + align:start position:0% +point of view of somebody who's + + + align:start position:0% +point of view of somebody who's +implementing the class so deciding all + + align:start position:0% +implementing the class so deciding all + + + align:start position:0% +implementing the class so deciding all +of these details that goes into creating + + align:start position:0% +of these details that goes into creating + + + align:start position:0% +of these details that goes into creating +the class itself versus somebody who's + + align:start position:0% +the class itself versus somebody who's + + + align:start position:0% +the class itself versus somebody who's +just using a class that's already been + + align:start position:0% +just using a class that's already been + + + align:start position:0% +just using a class that's already been +written where we create instances a + + align:start position:0% +written where we create instances a + + + align:start position:0% +written where we create instances a +bunch of different objects that just + + align:start position:0% +bunch of different objects that just + + + align:start position:0% +bunch of different objects that just +happen to be this data type + + align:start position:0% +happen to be this data type + + + align:start position:0% +happen to be this data type +so when we implement the class um what + + align:start position:0% +so when we implement the class um what + + + align:start position:0% +so when we implement the class um what +were some of the things we did well um + + align:start position:0% +were some of the things we did well um + + + align:start position:0% +were some of the things we did well um +we're telling python that this object + + align:start position:0% +we're telling python that this object + + + align:start position:0% +we're telling python that this object +now exists we're telling python the name + + align:start position:0% +now exists we're telling python the name + + + align:start position:0% +now exists we're telling python the name +of the data type that we're creating + + align:start position:0% +of the data type that we're creating + + + align:start position:0% +of the data type that we're creating +something we choose we're deciding um + + align:start position:0% +something we choose we're deciding um + + + align:start position:0% +something we choose we're deciding um +we're making these design decisions + + align:start position:0% +we're making these design decisions + + + align:start position:0% +we're making these design decisions +where we decide what attributes make up + + align:start position:0% +where we decide what attributes make up + + + align:start position:0% +where we decide what attributes make up +our class so the attributes are either + + align:start position:0% +our class so the attributes are either + + + align:start position:0% +our class so the attributes are either +data like the properties what are the + + align:start position:0% +data like the properties what are the + + + align:start position:0% +data like the properties what are the +variables that make up your object and + + align:start position:0% +variables that make up your object and + + + align:start position:0% +variables that make up your object and +the behaviors through methods right um + + align:start position:0% +the behaviors through methods right um + + + align:start position:0% +the behaviors through methods right um +so that's implementing the class and + + align:start position:0% +so that's implementing the class and + + + align:start position:0% +so that's implementing the class and +then when we're using the class we're + + align:start position:0% +then when we're using the class we're + + + align:start position:0% +then when we're using the class we're +now saying all right let's assume that + + align:start position:0% +now saying all right let's assume that + + + align:start position:0% +now saying all right let's assume that +this class definition exists there's + + align:start position:0% +this class definition exists there's + + + align:start position:0% +this class definition exists there's +this object that has these behaviors and + + align:start position:0% +this object that has these behaviors and + + + align:start position:0% +this object that has these behaviors and +these data attributes let's now create a + + align:start position:0% +these data attributes let's now create a + + + align:start position:0% +these data attributes let's now create a +whole bunch of objects that are of this + + align:start position:0% +whole bunch of objects that are of this + + + align:start position:0% +whole bunch of objects that are of this +type and this is when we're creating + + align:start position:0% +type and this is when we're creating + + + align:start position:0% +type and this is when we're creating +these instances and then manipulating + + align:start position:0% +these instances and then manipulating + + + align:start position:0% +these instances and then manipulating +all of these instances by running + + align:start position:0% +all of these instances by running + + + align:start position:0% +all of these instances by running +methods on them things like that so when + + align:start position:0% +methods on them things like that so when + + + align:start position:0% +methods on them things like that so when +we're implementing the class right this + + align:start position:0% +we're implementing the class right this + + + align:start position:0% +we're implementing the class right this +thing on the left hand side we're + + align:start position:0% +thing on the left hand side we're + + + align:start position:0% +thing on the left hand side we're +basically um uh telling python in + + align:start position:0% +basically um uh telling python in + + + align:start position:0% +basically um uh telling python in +abstract terms Ms what are the common + + align:start position:0% +abstract terms Ms what are the common + + + align:start position:0% +abstract terms Ms what are the common +properties and behaviors of our data + + align:start position:0% +properties and behaviors of our data + + + align:start position:0% +properties and behaviors of our data +type and then when we're using the class + + align:start position:0% +type and then when we're using the class + + + align:start position:0% +type and then when we're using the class +the thing on the right hand side here + + align:start position:0% +the thing on the right hand side here + + + align:start position:0% +the thing on the right hand side here +we're creating actual objects with very + + align:start position:0% +we're creating actual objects with very + + + align:start position:0% +we're creating actual objects with very +specific values for their data + + align:start position:0% +specific values for their data + + + align:start position:0% +specific values for their data +attributes that we can manipulate in + + align:start position:0% +attributes that we can manipulate in + + + align:start position:0% +attributes that we can manipulate in +different + + align:start position:0% +different + + + align:start position:0% +different +ways so let's remember this coordinate + + align:start position:0% +ways so let's remember this coordinate + + + align:start position:0% +ways so let's remember this coordinate +class that we wrote last lecture okay um + + align:start position:0% +class that we wrote last lecture okay um + + + align:start position:0% +class that we wrote last lecture okay um +this is not new so but I will just go + + align:start position:0% +this is not new so but I will just go + + + align:start position:0% +this is not new so but I will just go +over it real quick so first line here + + align:start position:0% +over it real quick so first line here + + + align:start position:0% +over it real quick so first line here +tells python we're creating a new data + + align:start position:0% +tells python we're creating a new data + + + align:start position:0% +tells python we're creating a new data +type its name is coordinate and this + + align:start position:0% +type its name is coordinate and this + + + align:start position:0% +type its name is coordinate and this +keyword class tells python we're + + align:start position:0% +keyword class tells python we're + + + align:start position:0% +keyword class tells python we're +creating the data type the parenthesis + + align:start position:0% +creating the data type the parenthesis + + + align:start position:0% +creating the data type the parenthesis +here is object which stands for the + + align:start position:0% +here is object which stands for the + + + align:start position:0% +here is object which stands for the +python object data type so it's + + align:start position:0% +python object data type so it's + + + align:start position:0% +python object data type so it's +something really generic um and this in + + align:start position:0% +something really generic um and this in + + + align:start position:0% +something really generic um and this in +the parenthesis here is the parent of + + align:start position:0% +the parenthesis here is the parent of + + + align:start position:0% +the parenthesis here is the parent of +our class right so anything that a + + align:start position:0% +our class right so anything that a + + + align:start position:0% +our class right so anything that a +regular python object can do the very + + align:start position:0% +regular python object can do the very + + + align:start position:0% +regular python object can do the very +basic things our class can do as well + + align:start position:0% +basic things our class can do as well + + + align:start position:0% +basic things our class can do as well +last lecture I mentioned an um an + + align:start position:0% +last lecture I mentioned an um an + + + align:start position:0% +last lecture I mentioned an um an +example of such a basic thing is to take + + align:start position:0% +example of such a basic thing is to take + + + align:start position:0% +example of such a basic thing is to take +a variable name and assign it to an + + align:start position:0% +a variable name and assign it to an + + + align:start position:0% +a variable name and assign it to an +object typee that we + + align:start position:0% +object typee that we + + + align:start position:0% +object typee that we +create the very first method that we + + align:start position:0% +create the very first method that we + + + align:start position:0% +create the very first method that we +should write for a new data type that we + + align:start position:0% +should write for a new data type that we + + + align:start position:0% +should write for a new data type that we +create is the init method and this I uh + + align:start position:0% +create is the init method and this I uh + + + align:start position:0% +create is the init method and this I uh +called a Dunder method because it starts + + align:start position:0% +called a Dunder method because it starts + + + align:start position:0% +called a Dunder method because it starts +with double underscores before the init + + align:start position:0% +with double underscores before the init + + + align:start position:0% +with double underscores before the init +and double UND and ends with double + + align:start position:0% +and double UND and ends with double + + + align:start position:0% +and double UND and ends with double +underscores after the init and that's + + align:start position:0% +underscores after the init and that's + + + align:start position:0% +underscores after the init and that's +the actual name of this method double + + align:start position:0% +the actual name of this method double + + + align:start position:0% +the actual name of this method double +underscore init double underscore okay + + align:start position:0% +underscore init double underscore okay + + + align:start position:0% +underscore init double underscore okay +um so this method is like a Constructor + + align:start position:0% +um so this method is like a Constructor + + + align:start position:0% +um so this method is like a Constructor +for the class it tells python how do you + + align:start position:0% +for the class it tells python how do you + + + align:start position:0% +for the class it tells python how do you +create an actual object of this type so + + align:start position:0% +create an actual object of this type so + + + align:start position:0% +create an actual object of this type so +it's it's a function uh it's just a + + align:start position:0% +it's it's a function uh it's just a + + + align:start position:0% +it's it's a function uh it's just a +function that works only with objects of + + align:start position:0% +function that works only with objects of + + + align:start position:0% +function that works only with objects of +type coordinate so as a function it + + align:start position:0% +type coordinate so as a function it + + + align:start position:0% +type coordinate so as a function it +takes + + align:start position:0% +takes + + + align:start position:0% +takes +parameters um you can see it takes three + + align:start position:0% +parameters um you can see it takes three + + + align:start position:0% +parameters um you can see it takes three +parameters here the self the X and the Y + + align:start position:0% +parameters here the self the X and the Y + + + align:start position:0% +parameters here the self the X and the Y +now when we're actually creating objects + + align:start position:0% +now when we're actually creating objects + + + align:start position:0% +now when we're actually creating objects +of type coordinate we only pass in + + align:start position:0% +of type coordinate we only pass in + + + align:start position:0% +of type coordinate we only pass in +parameters for everything other than + + align:start position:0% +parameters for everything other than + + + align:start position:0% +parameters for everything other than +self because self is a variable name + + align:start position:0% +self because self is a variable name + + + align:start position:0% +self because self is a variable name +that we use to describe cribe having an + + align:start position:0% +that we use to describe cribe having an + + + align:start position:0% +that we use to describe cribe having an +instance of the class without actually + + align:start position:0% +instance of the class without actually + + + align:start position:0% +instance of the class without actually +creating one yet right because remember + + align:start position:0% +creating one yet right because remember + + + align:start position:0% +creating one yet right because remember +what we're doing here in this definition + + align:start position:0% +what we're doing here in this definition + + + align:start position:0% +what we're doing here in this definition +we're telling python that this object + + align:start position:0% +we're telling python that this object + + + align:start position:0% +we're telling python that this object +type now exists we're writing it as we + + align:start position:0% +type now exists we're writing it as we + + + align:start position:0% +type now exists we're writing it as we +speak but we don't have an actual + + align:start position:0% +speak but we don't have an actual + + + align:start position:0% +speak but we don't have an actual +instance to manipulate yet right this is + + align:start position:0% +instance to manipulate yet right this is + + + align:start position:0% +instance to manipulate yet right this is +just the definition and so the self + + align:start position:0% +just the definition and so the self + + + align:start position:0% +just the definition and so the self +tells python that when we're writing + + align:start position:0% +tells python that when we're writing + + + align:start position:0% +tells python that when we're writing +this code we're going to use the self + + align:start position:0% +this code we're going to use the self + + + align:start position:0% +this code we're going to use the self +variable name as sort of a formal name + + align:start position:0% +variable name as sort of a formal name + + + align:start position:0% +variable name as sort of a formal name +to be able to run this method on okay so + + align:start position:0% +to be able to run this method on okay so + + + align:start position:0% +to be able to run this method on okay so +we're going to see in the next slide + + align:start position:0% +we're going to see in the next slide + + + align:start position:0% +we're going to see in the next slide +exactly how what what maps to self when + + align:start position:0% +exactly how what what maps to self when + + + align:start position:0% +exactly how what what maps to self when +we run it but that's what the self means + + align:start position:0% +we run it but that's what the self means + + + align:start position:0% +we run it but that's what the self means +inside the parameter list here and here + + align:start position:0% +inside the parameter list here and here + + + align:start position:0% +inside the parameter list here and here +and then beyond that we use uh self + + align:start position:0% +and then beyond that we use uh self + + + align:start position:0% +and then beyond that we use uh self +within the inip method to tell python + + align:start position:0% +within the inip method to tell python + + + align:start position:0% +within the inip method to tell python +which one of these variables are + + align:start position:0% +which one of these variables are + + + align:start position:0% +which one of these variables are +actually data attributes versus which of + + align:start position:0% +actually data attributes versus which of + + + align:start position:0% +actually data attributes versus which of +these variables are just plain old + + align:start position:0% +these variables are just plain old + + + align:start position:0% +these variables are just plain old +variables as we've been working with so + + align:start position:0% +variables as we've been working with so + + + align:start position:0% +variables as we've been working with so +any variable that's defined using self + + align:start position:0% +any variable that's defined using self + + + align:start position:0% +any variable that's defined using self +dot so here I got self.x and self.y are + + align:start position:0% +dot so here I got self.x and self.y are + + + align:start position:0% +dot so here I got self.x and self.y are +data attributes so that means any object + + align:start position:0% +data attributes so that means any object + + + align:start position:0% +data attributes so that means any object +I create that's of type coordinate I + + align:start position:0% +I create that's of type coordinate I + + + align:start position:0% +I create that's of type coordinate I +know will have a variable X and Y + + align:start position:0% +know will have a variable X and Y + + + align:start position:0% +know will have a variable X and Y +associated with it right because I've + + align:start position:0% +associated with it right because I've + + + align:start position:0% +associated with it right because I've +defined these X and y's using self.x and + + align:start position:0% +defined these X and y's using self.x and + + + align:start position:0% +defined these X and y's using self.x and +self.y now in the last lecture I + + align:start position:0% +self.y now in the last lecture I + + + align:start position:0% +self.y now in the last lecture I +actually had these parameter lists list + + align:start position:0% +actually had these parameter lists list + + + align:start position:0% +actually had these parameter lists list +the parameters in this list here be + + align:start position:0% +the parameters in this list here be + + + align:start position:0% +the parameters in this list here be +different than X and Y I think I had X + + align:start position:0% +different than X and Y I think I had X + + + align:start position:0% +different than X and Y I think I had X +Val y Val um and then I had self.x + + align:start position:0% +Val y Val um and then I had self.x + + + align:start position:0% +Val y Val um and then I had self.x +equals x valal where this x here to the + + align:start position:0% +equals x valal where this x here to the + + + align:start position:0% +equals x valal where this x here to the +right of the equal sign is the X from + + align:start position:0% +right of the equal sign is the X from + + + align:start position:0% +right of the equal sign is the X from +the parameter list right but you know so + + align:start position:0% +the parameter list right but you know so + + + align:start position:0% +the parameter list right but you know so +in that sense it doesn't matter what + + align:start position:0% +in that sense it doesn't matter what + + + align:start position:0% +in that sense it doesn't matter what +these variables are in the parameter + + align:start position:0% +these variables are in the parameter + + + align:start position:0% +these variables are in the parameter +list they're just going to be the same + + align:start position:0% +list they're just going to be the same + + + align:start position:0% +list they're just going to be the same +over here on the right hand side of the + + align:start position:0% +over here on the right hand side of the + + + align:start position:0% +over here on the right hand side of the +equal sign okay but the actual + + align:start position:0% +equal sign okay but the actual + + + align:start position:0% +equal sign okay but the actual +parameters the sorry the actual data + + align:start position:0% +parameters the sorry the actual data + + + align:start position:0% +parameters the sorry the actual data +attributes are self.x and self.y of my + + align:start position:0% +attributes are self.x and self.y of my + + + align:start position:0% +attributes are self.x and self.y of my +object + + align:start position:0% +object + + + align:start position:0% +object +right okay so then we had one method + + align:start position:0% +right okay so then we had one method + + + align:start position:0% +right okay so then we had one method +that we wrote last lecture it was called + + align:start position:0% +that we wrote last lecture it was called + + + align:start position:0% +that we wrote last lecture it was called +distance and it took two parameters so + + align:start position:0% +distance and it took two parameters so + + + align:start position:0% +distance and it took two parameters so +the first one of course is self and this + + align:start position:0% +the first one of course is self and this + + + align:start position:0% +the first one of course is self and this +self represents the thing this object + + align:start position:0% +self represents the thing this object + + + align:start position:0% +self represents the thing this object +that you're going to call the method on + + align:start position:0% +that you're going to call the method on + + + align:start position:0% +that you're going to call the method on +I don't have that object yet so I'm just + + align:start position:0% +I don't have that object yet so I'm just + + + align:start position:0% +I don't have that object yet so I'm just +calling itself for now um because this + + align:start position:0% +calling itself for now um because this + + + align:start position:0% +calling itself for now um because this +is the class definition and then this + + align:start position:0% +is the class definition and then this + + + align:start position:0% +is the class definition and then this +other parameter is no some other + + align:start position:0% +other parameter is no some other + + + align:start position:0% +other parameter is no some other +coordinate object that I'm going to run + + align:start position:0% +coordinate object that I'm going to run + + + align:start position:0% +coordinate object that I'm going to run +this method on so the body of distance + + align:start position:0% +this method on so the body of distance + + + align:start position:0% +this method on so the body of distance +says all right well how do I find the + + align:start position:0% +says all right well how do I find the + + + align:start position:0% +says all right well how do I find the +distance between two uh points in the 2D + + align:start position:0% +distance between two uh points in the 2D + + + align:start position:0% +distance between two uh points in the 2D +plane it's just Pythagoras right so that + + align:start position:0% +plane it's just Pythagoras right so that + + + align:start position:0% +plane it's just Pythagoras right so that +means grab the x value of one of my + + align:start position:0% +means grab the x value of one of my + + + align:start position:0% +means grab the x value of one of my +points subtract the x value of the other + + align:start position:0% +points subtract the x value of the other + + + align:start position:0% +points subtract the x value of the other +point Square them same with the Y's + + align:start position:0% +point Square them same with the Y's + + + align:start position:0% +point Square them same with the Y's +Square them add them take the square + + align:start position:0% +Square them add them take the square + + + align:start position:0% +Square them add them take the square +root so what's the x value of one point + + align:start position:0% +root so what's the x value of one point + + + align:start position:0% +root so what's the x value of one point +well one of the points is going to be + + align:start position:0% +well one of the points is going to be + + + align:start position:0% +well one of the points is going to be +the thing that I'm calling the distance + + align:start position:0% +the thing that I'm calling the distance + + + align:start position:0% +the thing that I'm calling the distance +method on self so I grab the x value of + + align:start position:0% +method on self so I grab the x value of + + + align:start position:0% +method on self so I grab the x value of +self using this do notation + + align:start position:0% +self using this do notation + + + align:start position:0% +self using this do notation +self.x and then what's the x value of + + align:start position:0% +self.x and then what's the x value of + + + align:start position:0% +self.x and then what's the x value of +this other coordinate point well it's + + align:start position:0% +this other coordinate point well it's + + + align:start position:0% +this other coordinate point well it's +called other in my parameter list so I'm + + align:start position:0% +called other in my parameter list so I'm + + + align:start position:0% +called other in my parameter list so I'm +going to grab the x value of other again + + align:start position:0% +going to grab the x value of other again + + + align:start position:0% +going to grab the x value of other again +using do notation okay and then we just + + align:start position:0% +using do notation okay and then we just + + + align:start position:0% +using do notation okay and then we just +do the + + align:start position:0% +do the + + + align:start position:0% +do the +math + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +yes yeah so you can make methods you can + + align:start position:0% +yes yeah so you can make methods you can + + + align:start position:0% +yes yeah so you can make methods you can +make methods for a particular + + align:start position:0% +make methods for a particular + + + align:start position:0% +make methods for a particular +class right but like you can only call + + align:start position:0% +class right but like you can only call + + + align:start position:0% +class right but like you can only call +those functions that you define call + + align:start position:0% +those functions that you define call + + + align:start position:0% +those functions that you define call +exactly yeah + + align:start position:0% +exactly yeah + + + align:start position:0% +exactly yeah +yeah yeah is there a way we could define + + align:start position:0% +yeah yeah is there a way we could define + + + align:start position:0% +yeah yeah is there a way we could define +a class as something other than an + + align:start position:0% +a class as something other than an + + + align:start position:0% +a class as something other than an +object a class is something other than + + align:start position:0% +object a class is something other than + + + align:start position:0% +object a class is something other than +an object right we put coordinate and + + align:start position:0% +an object right we put coordinate and + + + align:start position:0% +an object right we put coordinate and +object something else in the parenthesis + + align:start position:0% +object something else in the parenthesis + + + align:start position:0% +object something else in the parenthesis +yes we can put other things in the + + align:start position:0% +yes we can put other things in the + + + align:start position:0% +yes we can put other things in the +parentheses so that's actually what + + align:start position:0% +parentheses so that's actually what + + + align:start position:0% +parentheses so that's actually what +Monday's lecture will be about in that + + align:start position:0% +Monday's lecture will be about in that + + + align:start position:0% +Monday's lecture will be about in that +case the thing in the parentheses + + align:start position:0% +case the thing in the parentheses + + + align:start position:0% +case the thing in the parentheses +becomes the parent of the class that + + align:start position:0% +becomes the parent of the class that + + + align:start position:0% +becomes the parent of the class that +you're currently writing so I won't go + + align:start position:0% +you're currently writing so I won't go + + + align:start position:0% +you're currently writing so I won't go +into too much detail but to to have this + + align:start position:0% +into too much detail but to to have this + + + align:start position:0% +into too much detail but to to have this +other object as a parent means that + + align:start position:0% +other object as a parent means that + + + align:start position:0% +other object as a parent means that +everything that that object can do + + align:start position:0% +everything that that object can do + + + align:start position:0% +everything that that object can do +automatically your object can do as well + + align:start position:0% +automatically your object can do as well + + + align:start position:0% +automatically your object can do as well +and then on top of that you can decide a + + align:start position:0% +and then on top of that you can decide a + + + align:start position:0% +and then on top of that you can decide a +bunch of additional stuff your new + + align:start position:0% +bunch of additional stuff your new + + + align:start position:0% +bunch of additional stuff your new +object does but in a sense your + + align:start position:0% +object does but in a sense your + + + align:start position:0% +object does but in a sense your +coordinate object is a whatever this + + align:start position:0% +coordinate object is a whatever this + + + align:start position:0% +coordinate object is a whatever this +thing in the parenthesis is and then it + + align:start position:0% +thing in the parenthesis is and then it + + + align:start position:0% +thing in the parenthesis is and then it +can do a bunch of other stuff as well + + align:start position:0% +can do a bunch of other stuff as well + + + align:start position:0% +can do a bunch of other stuff as well +yeah simar how + + align:start position:0% + + + + align:start position:0% + +we yeah how do that + + align:start position:0% +we yeah how do that + + + align:start position:0% +we yeah how do that +oh to make a copy of the object or a + + align:start position:0% +oh to make a copy of the object or a + + + align:start position:0% +oh to make a copy of the object or a +copy of the class oh so here we're not + + align:start position:0% +copy of the class oh so here we're not + + + align:start position:0% +copy of the class oh so here we're not +you can't make a copy of the class here + + align:start position:0% +you can't make a copy of the class here + + + align:start position:0% +you can't make a copy of the class here +specifically because we're just defining + + align:start position:0% +specifically because we're just defining + + + align:start position:0% +specifically because we're just defining +the class but when you're creating + + align:start position:0% +the class but when you're creating + + + align:start position:0% +the class but when you're creating +coordinate objects then you could Define + + align:start position:0% +coordinate objects then you could Define + + + align:start position:0% +coordinate objects then you could Define +a method that copies your object into + + align:start position:0% +a method that copies your object into + + + align:start position:0% +a method that copies your object into +another + + align:start position:0% +another + + + align:start position:0% +another +object so in essence it would return a + + align:start position:0% +object so in essence it would return a + + + align:start position:0% +object so in essence it would return a +new object of type coordinate with + + align:start position:0% +new object of type coordinate with + + + align:start position:0% +new object of type coordinate with +whatever parameters you'd want to do + + align:start position:0% +whatever parameters you'd want to do + + + align:start position:0% +whatever parameters you'd want to do +yeah so all yeah all these things are + + align:start position:0% +yeah so all yeah all these things are + + + align:start position:0% +yeah so all yeah all these things are +are possible + + align:start position:0% +are possible + + + align:start position:0% +are possible +yeah so let's add one more method to + + align:start position:0% +yeah so let's add one more method to + + + align:start position:0% +yeah so let's add one more method to +this class let's call it 2core origin + + align:start position:0% +this class let's call it 2core origin + + + align:start position:0% +this class let's call it 2core origin +okay so this distance method just to + + align:start position:0% +okay so this distance method just to + + + align:start position:0% +okay so this distance method just to +remind ourselves returned a number right + + align:start position:0% +remind ourselves returned a number right + + + align:start position:0% +remind ourselves returned a number right +so it just took the difference between + + align:start position:0% +so it just took the difference between + + + align:start position:0% +so it just took the difference between +these two points and it returned a + + align:start position:0% +these two points and it returned a + + + align:start position:0% +these two points and it returned a +number just how far away they are but + + align:start position:0% +number just how far away they are but + + + align:start position:0% +number just how far away they are but +this two Origin method is going to do + + align:start position:0% +this two Origin method is going to do + + + align:start position:0% +this two Origin method is going to do +something slightly different essentially + + align:start position:0% +something slightly different essentially + + + align:start position:0% +something slightly different essentially +what I'm going to have this method do is + + align:start position:0% +what I'm going to have this method do is + + + align:start position:0% +what I'm going to have this method do is +to take my point from wherever it is in + + align:start position:0% +to take my point from wherever it is in + + + align:start position:0% +to take my point from wherever it is in +my 2D plane that it has been initialized + + align:start position:0% +my 2D plane that it has been initialized + + + align:start position:0% +my 2D plane that it has been initialized +to and say I'm going to reset it back to + + align:start position:0% +to and say I'm going to reset it back to + + + align:start position:0% +to and say I'm going to reset it back to +the + + align:start position:0% +the + + + align:start position:0% +the +origin right so to do that all that + + align:start position:0% +origin right so to do that all that + + + align:start position:0% +origin right so to do that all that +means is I'm going to make its uh x + + align:start position:0% +means is I'm going to make its uh x + + + align:start position:0% +means is I'm going to make its uh x +value and its yvalue be zero so I can + + align:start position:0% +value and its yvalue be zero so I can + + + align:start position:0% +value and its yvalue be zero so I can +manipulate the X and Y data attributes + + align:start position:0% +manipulate the X and Y data attributes + + + align:start position:0% +manipulate the X and Y data attributes +of this particular object to be whatever + + align:start position:0% +of this particular object to be whatever + + + align:start position:0% +of this particular object to be whatever +I want them to be so I can reset them + + align:start position:0% +I want them to be so I can reset them + + + align:start position:0% +I want them to be so I can reset them +both to zero so if I ever call this + + align:start position:0% +both to zero so if I ever call this + + + align:start position:0% +both to zero so if I ever call this +method on an object whose X and Y values + + align:start position:0% +method on an object whose X and Y values + + + align:start position:0% +method on an object whose X and Y values +are something other than zero they'll be + + align:start position:0% +are something other than zero they'll be + + + align:start position:0% +are something other than zero they'll be +reset to zero + + align:start position:0% +reset to zero + + + align:start position:0% +reset to zero +okay so let's actually uh run the code + + align:start position:0% +okay so let's actually uh run the code + + + align:start position:0% +okay so let's actually uh run the code +that that we just wrote so here I've got + + align:start position:0% +that that we just wrote so here I've got + + + align:start position:0% +that that we just wrote so here I've got +two coordinate objects being created so + + align:start position:0% +two coordinate objects being created so + + + align:start position:0% +two coordinate objects being created so +the beauty of writing this class for us + + align:start position:0% +the beauty of writing this class for us + + + align:start position:0% +the beauty of writing this class for us +is that now we can create as many + + align:start position:0% +is that now we can create as many + + + align:start position:0% +is that now we can create as many +coordinate objects as we'd like they all + + align:start position:0% +coordinate objects as we'd like they all + + + align:start position:0% +coordinate objects as we'd like they all +will have an x value and a yvalue + + align:start position:0% +will have an x value and a yvalue + + + align:start position:0% +will have an x value and a yvalue +associated with them it's just that the + + align:start position:0% +associated with them it's just that the + + + align:start position:0% +associated with them it's just that the +specific values for X and Y will be + + align:start position:0% +specific values for X and Y will be + + + align:start position:0% +specific values for X and Y will be +different right so here I've got a + + align:start position:0% +different right so here I've got a + + + align:start position:0% +different right so here I've got a +coordinate object with X3 and y4 being + + align:start position:0% +coordinate object with X3 and y4 being + + + align:start position:0% +coordinate object with X3 and y4 being +created and it's going to be bound by + + align:start position:0% +created and it's going to be bound by + + + align:start position:0% +created and it's going to be bound by +the variable named C and here a + + align:start position:0% +the variable named C and here a + + + align:start position:0% +the variable named C and here a +coordinate object with X and Y values + + align:start position:0% +coordinate object with X and Y values + + + align:start position:0% +coordinate object with X and Y values +both zero bound to a variable named + + align:start position:0% +both zero bound to a variable named + + + align:start position:0% +both zero bound to a variable named +origin okay so then I can use this dot + + align:start position:0% +origin okay so then I can use this dot + + + align:start position:0% +origin okay so then I can use this dot +notation that we talked about last + + align:start position:0% +notation that we talked about last + + + align:start position:0% +notation that we talked about last +lecture to access either data or to run + + align:start position:0% +lecture to access either data or to run + + + align:start position:0% +lecture to access either data or to run +methods on the on on the object so in + + align:start position:0% +methods on the on on the object so in + + + align:start position:0% +methods on the on on the object so in +this print uh print F uh statement here + + align:start position:0% +this print uh print F uh statement here + + + align:start position:0% +this print uh print F uh statement here +I'm using dot notation + + align:start position:0% +I'm using dot notation + + + align:start position:0% +I'm using dot notation +on C and origin to grab the X values of + + align:start position:0% +on C and origin to grab the X values of + + + align:start position:0% +on C and origin to grab the X values of +c over here and origin over here okay + + align:start position:0% +c over here and origin over here okay + + + align:start position:0% +c over here and origin over here okay +and then I'm running the distance method + + align:start position:0% +and then I'm running the distance method + + + align:start position:0% +and then I'm running the distance method +on C so remember dot notation says the + + align:start position:0% +on C so remember dot notation says the + + + align:start position:0% +on C so remember dot notation says the +thing before the dot is going to be an + + align:start position:0% +thing before the dot is going to be an + + + align:start position:0% +thing before the dot is going to be an +object the thing after the dot is going + + align:start position:0% +object the thing after the dot is going + + + align:start position:0% +object the thing after the dot is going +to be the method name that can run on + + align:start position:0% +to be the method name that can run on + + + align:start position:0% +to be the method name that can run on +this object of type whatever this is + + align:start position:0% +this object of type whatever this is + + + align:start position:0% +this object of type whatever this is +coordinate and then in the parentheses + + align:start position:0% +coordinate and then in the parentheses + + + align:start position:0% +coordinate and then in the parentheses +it's just a function we just pass in all + + align:start position:0% +it's just a function we just pass in all + + + align:start position:0% +it's just a function we just pass in all +the variables that that option that that + + align:start position:0% +the variables that that option that that + + + align:start position:0% +the variables that that option that that +method + + align:start position:0% +method + + + align:start position:0% +method +expects right so C do distance will + + align:start position:0% +expects right so C do distance will + + + align:start position:0% +expects right so C do distance will +print whatever you know however far away + + align:start position:0% +print whatever you know however far away + + + align:start position:0% +print whatever you know however far away +it is I no five because those are nice + + align:start position:0% +it is I no five because those are nice + + + align:start position:0% +it is I no five because those are nice +numbers okay so then if we run this + + align:start position:0% +numbers okay so then if we run this + + + align:start position:0% +numbers okay so then if we run this +function that we just wrote to origin + + align:start position:0% +function that we just wrote to origin + + + align:start position:0% +function that we just wrote to origin +this function just to remind you doesn't + + align:start position:0% +this function just to remind you doesn't + + + align:start position:0% +this function just to remind you doesn't +actually return anything right it just + + align:start position:0% +actually return anything right it just + + + align:start position:0% +actually return anything right it just +resets the variables X and Y for that + + align:start position:0% +resets the variables X and Y for that + + + align:start position:0% +resets the variables X and Y for that +particular object back to zero so in + + align:start position:0% +particular object back to zero so in + + + align:start position:0% +particular object back to zero so in +here when I call um this method here + + align:start position:0% +here when I call um this method here + + + align:start position:0% +here when I call um this method here +right again dot notation the thing + + align:start position:0% +right again dot notation the thing + + + align:start position:0% +right again dot notation the thing +before the dot is an object it's C its X + + align:start position:0% +before the dot is an object it's C its X + + + align:start position:0% +before the dot is an object it's C its X +and Y values are currently three and + + align:start position:0% +and Y values are currently three and + + + align:start position:0% +and Y values are currently three and +four but after I run this function it + + align:start position:0% +four but after I run this function it + + + align:start position:0% +four but after I run this function it +returns none by the way its X and Y + + align:start position:0% +returns none by the way its X and Y + + + align:start position:0% +returns none by the way its X and Y +values will be changed to zero and zero + + align:start position:0% +values will be changed to zero and zero + + + align:start position:0% +values will be changed to zero and zero +so if I look at my code here right so + + align:start position:0% +so if I look at my code here right so + + + align:start position:0% +so if I look at my code here right so +here's this print F + + align:start position:0% +here's this print F + + + align:start position:0% +here's this print F +statement right so C's x value is three + + align:start position:0% +statement right so C's x value is three + + + align:start position:0% +statement right so C's x value is three +and C's and origin's X is zero + + align:start position:0% +and C's and origin's X is zero + + + align:start position:0% +and C's and origin's X is zero +fine um and then I've got these two + + align:start position:0% +fine um and then I've got these two + + + align:start position:0% +fine um and then I've got these two +calls here so c.2 origin right I'm + + align:start position:0% +calls here so c.2 origin right I'm + + + align:start position:0% +calls here so c.2 origin right I'm +making this function call before the + + align:start position:0% +making this function call before the + + + align:start position:0% +making this function call before the +function call C's X is three C's Y is + + align:start position:0% +function call C's X is three C's Y is + + + align:start position:0% +function call C's X is three C's Y is +four and after the function call you can + + align:start position:0% +four and after the function call you can + + + align:start position:0% +four and after the function call you can +see C's X is zero and C's Y is zero so + + align:start position:0% +see C's X is zero and C's Y is zero so + + + align:start position:0% +see C's X is zero and C's Y is zero so +I'm literally changing the X and Y + + align:start position:0% +I'm literally changing the X and Y + + + align:start position:0% +I'm literally changing the X and Y +values of this object + + align:start position:0% +values of this object + + + align:start position:0% +values of this object +C + + align:start position:0% +C + + + align:start position:0% +C +okay all right so questions so far so + + align:start position:0% +okay all right so questions so far so + + + align:start position:0% +okay all right so questions so far so +far so good hopefully a recap + + align:start position:0% +far so good hopefully a recap + + + align:start position:0% +far so good hopefully a recap +okay so again sort of similar to the + + align:start position:0% +okay so again sort of similar to the + + + align:start position:0% +okay so again sort of similar to the +first slide we started with right so + + align:start position:0% +first slide we started with right so + + + align:start position:0% +first slide we started with right so +we've got this class coordinate object + + align:start position:0% +we've got this class coordinate object + + + align:start position:0% +we've got this class coordinate object +right the class name is our type so this + + align:start position:0% +right the class name is our type so this + + + align:start position:0% +right the class name is our type so this +object I'm creating is of type + + align:start position:0% +object I'm creating is of type + + + align:start position:0% +object I'm creating is of type +coordinate um we're defining the class + + align:start position:0% +coordinate um we're defining the class + + + align:start position:0% +coordinate um we're defining the class +in a generic way in an abstract way + + align:start position:0% +in a generic way in an abstract way + + + align:start position:0% +in a generic way in an abstract way +right so we have to use the self um uh + + align:start position:0% +right so we have to use the self um uh + + + align:start position:0% +right so we have to use the self um uh +variable either in the parameter list to + + align:start position:0% +variable either in the parameter list to + + + align:start position:0% +variable either in the parameter list to +tell python what's the thing before the + + align:start position:0% +tell python what's the thing before the + + + align:start position:0% +tell python what's the thing before the +dot going to map to well it's going to + + align:start position:0% +dot going to map to well it's going to + + + align:start position:0% +dot going to map to well it's going to +map to self in my parameter list or we + + align:start position:0% +map to self in my parameter list or we + + + align:start position:0% +map to self in my parameter list or we +use the self to tell python what the + + align:start position:0% +use the self to tell python what the + + + align:start position:0% +use the self to tell python what the +data attributes of this object are right + + align:start position:0% +data attributes of this object are right + + + align:start position:0% +data attributes of this object are right +so anything defined with self dot some + + align:start position:0% +so anything defined with self dot some + + + align:start position:0% +so anything defined with self dot some +variable uh name will be a data + + align:start position:0% +variable uh name will be a data + + + align:start position:0% +variable uh name will be a data +attribute that's common across all the + + align:start position:0% +attribute that's common across all the + + + align:start position:0% +attribute that's common across all the +instances I create so from of this type + + align:start position:0% +instances I create so from of this type + + + align:start position:0% +instances I create so from of this type +when we create actual instances that's + + align:start position:0% +when we create actual instances that's + + + align:start position:0% +when we create actual instances that's +when our uh our blueprint our abstract + + align:start position:0% +when our uh our blueprint our abstract + + + align:start position:0% +when our uh our blueprint our abstract +definition now you know gets put into + + align:start position:0% +definition now you know gets put into + + + align:start position:0% +definition now you know gets put into +use and now I'm creating actual uh + + align:start position:0% +use and now I'm creating actual uh + + + align:start position:0% +use and now I'm creating actual uh +objects that I can uh grab X values from + + align:start position:0% +objects that I can uh grab X values from + + + align:start position:0% +objects that I can uh grab X values from +change X values from you know get + + align:start position:0% +change X values from you know get + + + align:start position:0% +change X values from you know get +distances between other objects and so + + align:start position:0% +distances between other objects and so + + + align:start position:0% +distances between other objects and so +on and so on okay so what I'd like to do + + align:start position:0% +on and so on okay so what I'd like to do + + + align:start position:0% +on and so on okay so what I'd like to do +next is to um take this coordinate class + + align:start position:0% +next is to um take this coordinate class + + + align:start position:0% +next is to um take this coordinate class +and build uh a circle class with it so + + align:start position:0% +and build uh a circle class with it so + + + align:start position:0% +and build uh a circle class with it so +this comes uh sort of hand inand with + + align:start position:0% +this comes uh sort of hand inand with + + + align:start position:0% +this comes uh sort of hand inand with +the idea of when you're deciding how to + + align:start position:0% +the idea of when you're deciding how to + + + align:start position:0% +the idea of when you're deciding how to +create a class you get to make the + + align:start position:0% +create a class you get to make the + + + align:start position:0% +create a class you get to make the +design decision right so when the finger + + align:start position:0% +design decision right so when the finger + + + align:start position:0% +design decision right so when the finger +exercise for Monday's lecture today's + + align:start position:0% +exercise for Monday's lecture today's + + + align:start position:0% +exercise for Monday's lecture today's +Wednesday yes Monday's lecture um you + + align:start position:0% +Wednesday yes Monday's lecture um you + + + align:start position:0% +Wednesday yes Monday's lecture um you +guys had to create a a center uh sorry a + + align:start position:0% +guys had to create a a center uh sorry a + + + align:start position:0% +guys had to create a a center uh sorry a +circle class right but the way we + + align:start position:0% +circle class right but the way we + + + align:start position:0% +circle class right but the way we +defined the circle class in that finger + + align:start position:0% +defined the circle class in that finger + + + align:start position:0% +defined the circle class in that finger +exercise was basically by that circle's + + align:start position:0% +exercise was basically by that circle's + + + align:start position:0% +exercise was basically by that circle's +radius that's the only sort of way we + + align:start position:0% +radius that's the only sort of way we + + + align:start position:0% +radius that's the only sort of way we +abstracted that Circle right but now in + + align:start position:0% +abstracted that Circle right but now in + + + align:start position:0% +abstracted that Circle right but now in +in this lecture we're going to make a + + align:start position:0% +in this lecture we're going to make a + + + align:start position:0% +in this lecture we're going to make a +different design decision and say that + + align:start position:0% +different design decision and say that + + + align:start position:0% +different design decision and say that +let's say and say that a circle will now + + align:start position:0% +let's say and say that a circle will now + + + align:start position:0% +let's say and say that a circle will now +be defined using two things the first is + + align:start position:0% +be defined using two things the first is + + + align:start position:0% +be defined using two things the first is +the radius right so I'm going to say + + align:start position:0% +the radius right so I'm going to say + + + align:start position:0% +the radius right so I'm going to say +that that's an integer and the second is + + align:start position:0% +that that's an integer and the second is + + + align:start position:0% +that that's an integer and the second is +going to be the center of the circle + + align:start position:0% +going to be the center of the circle + + + align:start position:0% +going to be the center of the circle +right so as in the picture there I'm + + align:start position:0% +right so as in the picture there I'm + + + align:start position:0% +right so as in the picture there I'm +going to say that a circle is you know + + align:start position:0% +going to say that a circle is you know + + + align:start position:0% +going to say that a circle is you know +based on this Center and this radius and + + align:start position:0% +based on this Center and this radius and + + + align:start position:0% +based on this Center and this radius and +the center is not going to be a float + + align:start position:0% +the center is not going to be a float + + + align:start position:0% +the center is not going to be a float +it's not going to be a tuple it's not + + align:start position:0% +it's not going to be a tuple it's not + + + align:start position:0% +it's not going to be a tuple it's not +going to be an INT it's going to be a a + + align:start position:0% +going to be an INT it's going to be a a + + + align:start position:0% +going to be an INT it's going to be a a +coordinate + + align:start position:0% +coordinate + + + align:start position:0% +coordinate +object right the data type that we were + + align:start position:0% +object right the data type that we were + + + align:start position:0% +object right the data type that we were +just + + align:start position:0% +just + + + align:start position:0% +just +writing + + align:start position:0% +writing + + + align:start position:0% +writing +okay all right good it's not a secret + + align:start position:0% +okay all right good it's not a secret + + + align:start position:0% +okay all right good it's not a secret +but that didn't lower my voice on + + align:start position:0% +but that didn't lower my voice on + + + align:start position:0% +but that didn't lower my voice on +purpose just just wanted to let that + + align:start position:0% +purpose just just wanted to let that + + + align:start position:0% +purpose just just wanted to let that +sink in right so the one of our data + + align:start position:0% +sink in right so the one of our data + + + align:start position:0% +sink in right so the one of our data +attributes for the circle class is a + + align:start position:0% +attributes for the circle class is a + + + align:start position:0% +attributes for the circle class is a +coordinate object so we're using an + + align:start position:0% +coordinate object so we're using an + + + align:start position:0% +coordinate object so we're using an +object that we just wrote to create a + + align:start position:0% +object that we just wrote to create a + + + align:start position:0% +object that we just wrote to create a +more complex object a circle okay so + + align:start position:0% +more complex object a circle okay so + + + align:start position:0% +more complex object a circle okay so +here's my class definition uh the data + + align:start position:0% +here's my class definition uh the data + + + align:start position:0% +here's my class definition uh the data +type is called Circle again it inherits + + align:start position:0% +type is called Circle again it inherits + + + align:start position:0% +type is called Circle again it inherits +all uh the parent of circle is just a + + align:start position:0% +all uh the parent of circle is just a + + + align:start position:0% +all uh the parent of circle is just a +generic python object first method we + + align:start position:0% +generic python object first method we + + + align:start position:0% +generic python object first method we +have to write is the init + + align:start position:0% +have to write is the init + + + align:start position:0% +have to write is the init +method uh first parameter is self so + + align:start position:0% +method uh first parameter is self so + + + align:start position:0% +method uh first parameter is self so +this thing that I'm creating right now + + align:start position:0% +this thing that I'm creating right now + + + align:start position:0% +this thing that I'm creating right now +and I say that to create a circle I have + + align:start position:0% +and I say that to create a circle I have + + + align:start position:0% +and I say that to create a circle I have +to give it a center and I have to give + + align:start position:0% +to give it a center and I have to give + + + align:start position:0% +to give it a center and I have to give +it a + + align:start position:0% +it a + + + align:start position:0% +it a +radius the data attributes of the circle + + align:start position:0% +radius the data attributes of the circle + + + align:start position:0% +radius the data attributes of the circle +class right so the the two attributes + + align:start position:0% +class right so the the two attributes + + + align:start position:0% +class right so the the two attributes +that make up my circle are this self. + + align:start position:0% +that make up my circle are this self. + + + align:start position:0% +that make up my circle are this self. +Center so the center variable here and + + align:start position:0% +Center so the center variable here and + + + align:start position:0% +Center so the center variable here and +self. radius right so these two things + + align:start position:0% +self. radius right so these two things + + + align:start position:0% +self. radius right so these two things +together make up our Circle + + align:start position:0% +together make up our Circle + + + align:start position:0% +together make up our Circle +object and initially in the init method + + align:start position:0% +object and initially in the init method + + + align:start position:0% +object and initially in the init method +right and when we conru Constructor + + align:start position:0% +right and when we conru Constructor + + + align:start position:0% +right and when we conru Constructor +object we're just going to set these two + + align:start position:0% +object we're just going to set these two + + + align:start position:0% +object we're just going to set these two +things to be whatever is passed in as + + align:start position:0% +things to be whatever is passed in as + + + align:start position:0% +things to be whatever is passed in as +parameters in that uh in the + + align:start position:0% +parameters in that uh in the + + + align:start position:0% +parameters in that uh in the +Constructor okay all + + align:start position:0% +Constructor okay all + + + align:start position:0% +Constructor okay all +right so what I'd like to say is that + + align:start position:0% +right so what I'd like to say is that + + + align:start position:0% +right so what I'd like to say is that +this um Center thing uh Center parameter + + align:start position:0% +this um Center thing uh Center parameter + + + align:start position:0% +this um Center thing uh Center parameter +will be a coordinate object and radius + + align:start position:0% +will be a coordinate object and radius + + + align:start position:0% +will be a coordinate object and radius +will be an INT now notice in this code + + align:start position:0% +will be an INT now notice in this code + + + align:start position:0% +will be an INT now notice in this code +I'm not actually enforcing this right I + + align:start position:0% +I'm not actually enforcing this right I + + + align:start position:0% +I'm not actually enforcing this right I +could create a set a circle object by + + align:start position:0% +could create a set a circle object by + + + align:start position:0% +could create a set a circle object by +just passing in two + + align:start position:0% +just passing in two + + + align:start position:0% +just passing in two +strings right at this point this code + + align:start position:0% +strings right at this point this code + + + align:start position:0% +strings right at this point this code +doesn't care right nowhere am I + + align:start position:0% +doesn't care right nowhere am I + + + align:start position:0% +doesn't care right nowhere am I +enforcing the fact that Center is a + + align:start position:0% +enforcing the fact that Center is a + + + align:start position:0% +enforcing the fact that Center is a +coordinate and radius will be in it but + + align:start position:0% +coordinate and radius will be in it but + + + align:start position:0% +coordinate and radius will be in it but +you know that's just something that we + + align:start position:0% +you know that's just something that we + + + align:start position:0% +you know that's just something that we +we + + align:start position:0% +we + + + align:start position:0% +we +know so then when we create the actual + + align:start position:0% +know so then when we create the actual + + + align:start position:0% +know so then when we create the actual +um object down here right my underscore + + align:start position:0% +um object down here right my underscore + + + align:start position:0% +um object down here right my underscore +circle is going to be a variable that's + + align:start position:0% +circle is going to be a variable that's + + + align:start position:0% +circle is going to be a variable that's +bound to my circle object so here I'm + + align:start position:0% +bound to my circle object so here I'm + + + align:start position:0% +bound to my circle object so here I'm +invoking the name of my class Circle and + + align:start position:0% +invoking the name of my class Circle and + + + align:start position:0% +invoking the name of my class Circle and +then what are the two parameters I'm + + align:start position:0% +then what are the two parameters I'm + + + align:start position:0% +then what are the two parameters I'm +passing in well the first one I said + + align:start position:0% +passing in well the first one I said + + + align:start position:0% +passing in well the first one I said +right up here that it should be a center + + align:start position:0% +right up here that it should be a center + + + align:start position:0% +right up here that it should be a center +a a coordinate object so Center is a + + align:start position:0% +a a coordinate object so Center is a + + + align:start position:0% +a a coordinate object so Center is a +variable name and what is it well I had + + align:start position:0% +variable name and what is it well I had + + + align:start position:0% +variable name and what is it well I had +to create this coordinate object right + + align:start position:0% +to create this coordinate object right + + + align:start position:0% +to create this coordinate object right +so I'm just invoking the name of + + align:start position:0% +so I'm just invoking the name of + + + align:start position:0% +so I'm just invoking the name of +coordinate this class that creates for + + align:start position:0% +coordinate this class that creates for + + + align:start position:0% +coordinate this class that creates for +me a coordinate object and I happen to + + align:start position:0% +me a coordinate object and I happen to + + + align:start position:0% +me a coordinate object and I happen to +put the center of the circle at two + + align:start position:0% +put the center of the circle at two + + + align:start position:0% +put the center of the circle at two +comma 2 uh yeah + + align:start position:0% +comma 2 uh yeah + + + align:start position:0% +comma 2 uh yeah +okay so this Center thing is a + + align:start position:0% +okay so this Center thing is a + + + align:start position:0% +okay so this Center thing is a +coordinate object right it's not a tuple + + align:start position:0% +coordinate object right it's not a tuple + + + align:start position:0% +coordinate object right it's not a tuple +or float or whatever it's a coordinate + + align:start position:0% +or float or whatever it's a coordinate + + + align:start position:0% +or float or whatever it's a coordinate +object and then the radius of this uh + + align:start position:0% +object and then the radius of this uh + + + align:start position:0% +object and then the radius of this uh +circle is two an + + align:start position:0% + + + + align:start position:0% + +INT everyone okay with that okay so what + + align:start position:0% +INT everyone okay with that okay so what + + + align:start position:0% +INT everyone okay with that okay so what +I'd like you to do next is to modify + + align:start position:0% +I'd like you to do next is to modify + + + align:start position:0% +I'd like you to do next is to modify +this init method just slightly just to + + align:start position:0% +this init method just slightly just to + + + align:start position:0% +this init method just slightly just to +show you that the init method doesn't + + align:start position:0% +show you that the init method doesn't + + + align:start position:0% +show you that the init method doesn't +just always set the data attributes and + + align:start position:0% +just always set the data attributes and + + + align:start position:0% +just always set the data attributes and +it's done it can do a lot of + + align:start position:0% +it's done it can do a lot of + + + align:start position:0% +it's done it can do a lot of +initialization code one of the more + + align:start position:0% +initialization code one of the more + + + align:start position:0% +initialization code one of the more +important things it can do is to try to + + align:start position:0% +important things it can do is to try to + + + align:start position:0% +important things it can do is to try to +enforce the types on the uh on the + + align:start position:0% +enforce the types on the uh on the + + + align:start position:0% +enforce the types on the uh on the +parameters here right so what I'd like + + align:start position:0% +parameters here right so what I'd like + + + align:start position:0% +parameters here right so what I'd like +you to do is add to this code to uh to + + align:start position:0% +you to do is add to this code to uh to + + + align:start position:0% +you to do is add to this code to uh to +to check that the type of Center is a + + align:start position:0% +to check that the type of Center is a + + + align:start position:0% +to check that the type of Center is a +coordinate and the type of radius is an + + align:start position:0% +coordinate and the type of radius is an + + + align:start position:0% +coordinate and the type of radius is an +integer and only if those two things are + + align:start position:0% +integer and only if those two things are + + + align:start position:0% +integer and only if those two things are +true then do you set uh the the two data + + align:start position:0% +true then do you set uh the the two data + + + align:start position:0% +true then do you set uh the the two data +attributes and otherwise raise for me a + + align:start position:0% +attributes and otherwise raise for me a + + + align:start position:0% +attributes and otherwise raise for me a +value error + + align:start position:0% +value error + + + align:start position:0% +value error +okay so that should be around + + align:start position:0% +okay so that should be around + + + align:start position:0% +okay so that should be around +uh line + + align:start position:0% + + + + align:start position:0% + +48 okay does anyone have some code for + + align:start position:0% + + + + align:start position:0% + +me + + align:start position:0% + + + + align:start position:0% + +yeah not equal coordinate yep so that's + + align:start position:0% +yeah not equal coordinate yep so that's + + + align:start position:0% +yeah not equal coordinate yep so that's +raise value a + + align:start position:0% +raise value a + + + align:start position:0% +raise value a +yep cool so that takes care of one + + align:start position:0% +yep cool so that takes care of one + + + align:start position:0% +yep cool so that takes care of one +yep + + align:start position:0% + + + + align:start position:0% + +yep so if the type of radius because + + align:start position:0% +yep so if the type of radius because + + + align:start position:0% +yep so if the type of radius because +that's the parameter passed in not equal + + align:start position:0% +that's the parameter passed in not equal + + + align:start position:0% +that's the parameter passed in not equal +to + + align:start position:0% +to + + + align:start position:0% +to +int raise value + + align:start position:0% + + + + align:start position:0% + +there so if if we drop into each of any + + align:start position:0% +there so if if we drop into each of any + + + align:start position:0% +there so if if we drop into each of any +of these ifs then we immediately raise + + align:start position:0% +of these ifs then we immediately raise + + + align:start position:0% +of these ifs then we immediately raise +the value error right the code doesn't + + align:start position:0% +the value error right the code doesn't + + + align:start position:0% +the value error right the code doesn't +complete and then only if we didn't drop + + align:start position:0% +complete and then only if we didn't drop + + + align:start position:0% +complete and then only if we didn't drop +into this one or this one do we then go + + align:start position:0% +into this one or this one do we then go + + + align:start position:0% +into this one or this one do we then go +on to create my object so then here we + + align:start position:0% +on to create my object so then here we + + + align:start position:0% +on to create my object so then here we +are these two lines here will uh succeed + + align:start position:0% +are these two lines here will uh succeed + + + align:start position:0% +are these two lines here will uh succeed +right so there's no error raised or + + align:start position:0% +right so there's no error raised or + + + align:start position:0% +right so there's no error raised or +anything like that but then this line + + align:start position:0% +anything like that but then this line + + + align:start position:0% +anything like that but then this line +here raised our value error because we + + align:start position:0% +here raised our value error because we + + + align:start position:0% +here raised our value error because we +tried to create a circle where the + + align:start position:0% +tried to create a circle where the + + + align:start position:0% +tried to create a circle where the +center is an integer right obviously not + + align:start position:0% +center is an integer right obviously not + + + align:start position:0% +center is an integer right obviously not +a coordinate object and then here again + + align:start position:0% +a coordinate object and then here again + + + align:start position:0% +a coordinate object and then here again +we raised our value error because we + + align:start position:0% +we raised our value error because we + + + align:start position:0% +we raised our value error because we +tried to pass in a string as the radius + + align:start position:0% +tried to pass in a string as the radius + + + align:start position:0% +tried to pass in a string as the radius +any questions about this + + align:start position:0% +any questions about this + + + align:start position:0% +any questions about this +code + + align:start position:0% +code + + + align:start position:0% +code +oh yeah + + align:start position:0% + + + + align:start position:0% + +sorry yeah so it's it's important to + + align:start position:0% +sorry yeah so it's it's important to + + + align:start position:0% +sorry yeah so it's it's important to +place them before you actually create + + align:start position:0% +place them before you actually create + + + align:start position:0% +place them before you actually create +the object right because you don't want + + align:start position:0% +the object right because you don't want + + + align:start position:0% +the object right because you don't want +to create it unless unless uh yeah + + align:start position:0% +to create it unless unless uh yeah + + + align:start position:0% +to create it unless unless uh yeah +unless + + align:start position:0% +unless + + + align:start position:0% +unless +everything's + + align:start position:0% + + + + align:start position:0% + +appropriate + + align:start position:0% +appropriate + + + align:start position:0% +appropriate +okay so now let's add one more useful + + align:start position:0% +okay so now let's add one more useful + + + align:start position:0% +okay so now let's add one more useful +method to our class + + align:start position:0% +method to our class + + + align:start position:0% +method to our class +Circle now that we've defined a a circle + + align:start position:0% +Circle now that we've defined a a circle + + + align:start position:0% +Circle now that we've defined a a circle +using a center point and a radius we can + + align:start position:0% +using a center point and a radius we can + + + align:start position:0% +using a center point and a radius we can +add this little function that checks if + + align:start position:0% +add this little function that checks if + + + align:start position:0% +add this little function that checks if +another coordinate + + align:start position:0% +another coordinate + + + align:start position:0% +another coordinate +object is inside our + + align:start position:0% +object is inside our + + + align:start position:0% +object is inside our +Circle okay so again I'm not going to be + + align:start position:0% +Circle okay so again I'm not going to be + + + align:start position:0% +Circle okay so again I'm not going to be +able to + + align:start position:0% +able to + + + align:start position:0% +able to +enforce um that this point is a + + align:start position:0% +enforce um that this point is a + + + align:start position:0% +enforce um that this point is a +coordinate object but you know you could + + align:start position:0% +coordinate object but you know you could + + + align:start position:0% +coordinate object but you know you could +do it in the dock string or you could do + + align:start position:0% +do it in the dock string or you could do + + + align:start position:0% +do it in the dock string or you could do +a check or something like that but you + + align:start position:0% +a check or something like that but you + + + align:start position:0% +a check or something like that but you +know again we're just going to assume + + align:start position:0% +know again we're just going to assume + + + align:start position:0% +know again we're just going to assume +the user using this method is going to + + align:start position:0% +the user using this method is going to + + + align:start position:0% +the user using this method is going to +follow the rules so how is this method + + align:start position:0% +follow the rules so how is this method + + + align:start position:0% +follow the rules so how is this method +going to work the idea here is that + + align:start position:0% +going to work the idea here is that + + + align:start position:0% +going to work the idea here is that +we're going to use the center which is a + + align:start position:0% +we're going to use the center which is a + + + align:start position:0% +we're going to use the center which is a +coordinate object and some other point + + align:start position:0% +coordinate object and some other point + + + align:start position:0% +coordinate object and some other point +you know P wherever it may be what we're + + align:start position:0% +you know P wherever it may be what we're + + + align:start position:0% +you know P wherever it may be what we're +going to do is we're going to say what's + + align:start position:0% +going to do is we're going to say what's + + + align:start position:0% +going to do is we're going to say what's +the distance between this point and the + + align:start position:0% +the distance between this point and the + + + align:start position:0% +the distance between this point and the +center of the circle if it's greater + + align:start position:0% +center of the circle if it's greater + + + align:start position:0% +center of the circle if it's greater +than the radius we know the point is + + align:start position:0% +than the radius we know the point is + + + align:start position:0% +than the radius we know the point is +outside the circle if it's smaller than + + align:start position:0% +outside the circle if it's smaller than + + + align:start position:0% +outside the circle if it's smaller than +the radius we know the point is in the + + align:start position:0% +the radius we know the point is in the + + + align:start position:0% +the radius we know the point is in the +circle right so this code is just + + align:start position:0% +circle right so this code is just + + + align:start position:0% +circle right so this code is just +enforcing that so we have uh just a + + align:start position:0% +enforcing that so we have uh just a + + + align:start position:0% +enforcing that so we have uh just a +simple return + + align:start position:0% +simple return + + + align:start position:0% +simple return +statement that's going to run the + + align:start position:0% +statement that's going to run the + + + align:start position:0% +statement that's going to run the +distance method right this is a method + + align:start position:0% +distance method right this is a method + + + align:start position:0% +distance method right this is a method +that we + + align:start position:0% + + + + align:start position:0% + +wrote back in the coordinate class right + + align:start position:0% +wrote back in the coordinate class right + + + align:start position:0% +wrote back in the coordinate class right +that's fine because you know what point + + align:start position:0% +that's fine because you know what point + + + align:start position:0% +that's fine because you know what point +is an object of type coordinate and + + align:start position:0% +is an object of type coordinate and + + + align:start position:0% +is an object of type coordinate and +self. Center so the center of this + + align:start position:0% +self. Center so the center of this + + + align:start position:0% +self. Center so the center of this +circle object I'm trying to manipulate + + align:start position:0% +circle object I'm trying to manipulate + + + align:start position:0% +circle object I'm trying to manipulate +right to tell if another point is inside + + align:start position:0% +right to tell if another point is inside + + + align:start position:0% +right to tell if another point is inside +me or not is also a coordinate object + + align:start position:0% +me or not is also a coordinate object + + + align:start position:0% +me or not is also a coordinate object +object so why not we already wrote the + + align:start position:0% +object so why not we already wrote the + + + align:start position:0% +object so why not we already wrote the +code that calculates the distance + + align:start position:0% +code that calculates the distance + + + align:start position:0% +code that calculates the distance +between these two points so let's call + + align:start position:0% +between these two points so let's call + + + align:start position:0% +between these two points so let's call +it so here I've got the thing before the + + align:start position:0% +it so here I've got the thing before the + + + align:start position:0% +it so here I've got the thing before the +dot a coordinate object dot notation the + + align:start position:0% +dot a coordinate object dot notation the + + + align:start position:0% +dot a coordinate object dot notation the +method I want to run on this coordinate + + align:start position:0% +method I want to run on this coordinate + + + align:start position:0% +method I want to run on this coordinate +object and then in parentheses this is + + align:start position:0% +object and then in parentheses this is + + + align:start position:0% +object and then in parentheses this is +another coordinate object so this will + + align:start position:0% +another coordinate object so this will + + + align:start position:0% +another coordinate object so this will +just tell me some number for how far + + align:start position:0% +just tell me some number for how far + + + align:start position:0% +just tell me some number for how far +away these two points are and all we do + + align:start position:0% +away these two points are and all we do + + + align:start position:0% +away these two points are and all we do +is return whether that number is less + + align:start position:0% +is return whether that number is less + + + align:start position:0% +is return whether that number is less +than the + + align:start position:0% +than the + + + align:start position:0% +than the +radius okay does that make + + align:start position:0% +radius okay does that make + + + align:start position:0% +radius okay does that make +sense + + align:start position:0% +sense + + + align:start position:0% +sense +and again this only works if point the + + align:start position:0% +and again this only works if point the + + + align:start position:0% +and again this only works if point the +thing that's passed in here is a + + align:start position:0% +thing that's passed in here is a + + + align:start position:0% +thing that's passed in here is a +coordinate object right otherwise this + + align:start position:0% +coordinate object right otherwise this + + + align:start position:0% +coordinate object right otherwise this +code will fail because it's going to try + + align:start position:0% +code will fail because it's going to try + + + align:start position:0% +code will fail because it's going to try +to pass in uh it's going to try to run + + align:start position:0% +to pass in uh it's going to try to run + + + align:start position:0% +to pass in uh it's going to try to run +the distance method on a string for + + align:start position:0% +the distance method on a string for + + + align:start position:0% +the distance method on a string for +example and of course the string doesn't + + align:start position:0% +example and of course the string doesn't + + + align:start position:0% +example and of course the string doesn't +have a distance method right so down + + align:start position:0% +have a distance method right so down + + + align:start position:0% +have a distance method right so down +here uh these two lines are exactly as + + align:start position:0% +here uh these two lines are exactly as + + + align:start position:0% +here uh these two lines are exactly as +we had before we create a circle object + + align:start position:0% +we had before we create a circle object + + + align:start position:0% +we had before we create a circle object +whose Center is at 2 comma 2 and radius + + align:start position:0% +whose Center is at 2 comma 2 and radius + + + align:start position:0% +whose Center is at 2 comma 2 and radius +is two and then I've got another + + align:start position:0% +is two and then I've got another + + + align:start position:0% +is two and then I've got another +coordinate object down down here uh it's + + align:start position:0% +coordinate object down down here uh it's + + + align:start position:0% +coordinate object down down here uh it's +uh at 1 comma 1 right so clearly within + + align:start position:0% +uh at 1 comma 1 right so clearly within + + + align:start position:0% +uh at 1 comma 1 right so clearly within +the circle so that print statement will + + align:start position:0% +the circle so that print statement will + + + align:start position:0% +the circle so that print statement will +then print true right so that's just + + align:start position:0% +then print true right so that's just + + + align:start position:0% +then print true right so that's just +basically what I wrote this is a + + align:start position:0% +basically what I wrote this is a + + + align:start position:0% +basically what I wrote this is a +coordinate object this is the method + + align:start position:0% +coordinate object this is the method + + + align:start position:0% +coordinate object this is the method +this is another coordinate + + align:start position:0% +this is another coordinate + + + align:start position:0% +this is another coordinate +object right so let's run + + align:start position:0% + + + + align:start position:0% + +it so this is exactly the code from the + + align:start position:0% +it so this is exactly the code from the + + + align:start position:0% +it so this is exactly the code from the +slide so if I run this method on a + + align:start position:0% +slide so if I run this method on a + + + align:start position:0% +slide so if I run this method on a +coordinate object that's one comma one + + align:start position:0% +coordinate object that's one comma one + + + align:start position:0% +coordinate object that's one comma one +somewhere in here so true and otherwise + + align:start position:0% +somewhere in here so true and otherwise + + + align:start position:0% +somewhere in here so true and otherwise +if I run it on coordinate object right + + align:start position:0% +if I run it on coordinate object right + + + align:start position:0% +if I run it on coordinate object right +here P 10 comma 10 clearly outside the + + align:start position:0% +here P 10 comma 10 clearly outside the + + + align:start position:0% +here P 10 comma 10 clearly outside the +circle it prints + + align:start position:0% + + + + align:start position:0% + +false + + align:start position:0% + + + + align:start position:0% + +questions + + align:start position:0% +questions + + + align:start position:0% +questions +okay um uh yes that's exactly what I + + align:start position:0% +okay um uh yes that's exactly what I + + + align:start position:0% +okay um uh yes that's exactly what I +said already okay + + align:start position:0% +said already okay + + + align:start position:0% +said already okay +good so now I want you to answer this + + align:start position:0% +good so now I want you to answer this + + + align:start position:0% +good so now I want you to answer this +question nothing to code here but I've + + align:start position:0% +question nothing to code here but I've + + + align:start position:0% +question nothing to code here but I've +got these two is inside method so the + + align:start position:0% +got these two is inside method so the + + + align:start position:0% +got these two is inside method so the +first one here is inside one is exactly + + align:start position:0% +first one here is inside one is exactly + + + align:start position:0% +first one here is inside one is exactly +the one that we just saw right it runs + + align:start position:0% +the one that we just saw right it runs + + + align:start position:0% +the one that we just saw right it runs +dist distance method with point and + + align:start position:0% +dist distance method with point and + + + align:start position:0% +dist distance method with point and +self. Center is inside two looks + + align:start position:0% +self. Center is inside two looks + + + align:start position:0% +self. Center is inside two looks +slightly different the differences I've + + align:start position:0% +slightly different the differences I've + + + align:start position:0% +slightly different the differences I've +highlighted in this box what I'd like + + align:start position:0% +highlighted in this box what I'd like + + + align:start position:0% +highlighted in this box what I'd like +you to tell me we can do a show of hands + + align:start position:0% +you to tell me we can do a show of hands + + + align:start position:0% +you to tell me we can do a show of hands +is are these two function these two + + align:start position:0% +is are these two function these two + + + align:start position:0% +is are these two function these two +methods functionally equivalent that is + + align:start position:0% +methods functionally equivalent that is + + + align:start position:0% +methods functionally equivalent that is +will they return the same thing given + + align:start position:0% +will they return the same thing given + + + align:start position:0% +will they return the same thing given +the same input right so think about it + + align:start position:0% +the same input right so think about it + + + align:start position:0% +the same input right so think about it +and then + + align:start position:0% +and then + + + align:start position:0% +and then +I + + align:start position:0% +I + + + align:start position:0% +I +will do a show of + + align:start position:0% + + + + align:start position:0% + +hands so who thinks yes they are + + align:start position:0% +hands so who thinks yes they are + + + align:start position:0% +hands so who thinks yes they are +functionally + + align:start position:0% +functionally + + + align:start position:0% +functionally +equivalent like given the same input + + align:start position:0% +equivalent like given the same input + + + align:start position:0% +equivalent like given the same input +they will both return true right in part + + align:start position:0% +they will both return true right in part + + + align:start position:0% +they will both return true right in part +false okay who thinks no they are not + + align:start position:0% +false okay who thinks no they are not + + + align:start position:0% +false okay who thinks no they are not +functionally + + align:start position:0% +functionally + + + align:start position:0% +functionally +equivalent some half and + + align:start position:0% +equivalent some half and + + + align:start position:0% +equivalent some half and +half okay well let's think about what + + align:start position:0% +half okay well let's think about what + + + align:start position:0% +half okay well let's think about what +the distance method is + + align:start position:0% +the distance method is + + + align:start position:0% +the distance method is +doing + + align:start position:0% +doing + + + align:start position:0% +doing +it's being run on an object of + + align:start position:0% +it's being run on an object of + + + align:start position:0% +it's being run on an object of +type + + align:start position:0% + + + + align:start position:0% + +what coordinate exactly so in here is + + align:start position:0% +what coordinate exactly so in here is + + + align:start position:0% +what coordinate exactly so in here is +point an object of type coordinate yes + + align:start position:0% +point an object of type coordinate yes + + + align:start position:0% +point an object of type coordinate yes +okay and then here what is the a + + align:start position:0% +okay and then here what is the a + + + align:start position:0% +okay and then here what is the a +parameter to the distance method is it + + align:start position:0% +parameter to the distance method is it + + + align:start position:0% +parameter to the distance method is it +object of type coordinate self. Center + + align:start position:0% +object of type coordinate self. Center + + + align:start position:0% +object of type coordinate self. Center +is it an object of type coordinate yes + + align:start position:0% +is it an object of type coordinate yes + + + align:start position:0% +is it an object of type coordinate yes +so now let's look that is inside two + + align:start position:0% +so now let's look that is inside two + + + align:start position:0% +so now let's look that is inside two +what is the type of self. + + align:start position:0% +what is the type of self. + + + align:start position:0% +what is the type of self. +Center coordinate and we're running the + + align:start position:0% +Center coordinate and we're running the + + + align:start position:0% +Center coordinate and we're running the +distance method on this object of type + + align:start position:0% +distance method on this object of type + + + align:start position:0% +distance method on this object of type +coordinate and what is the object in the + + align:start position:0% +coordinate and what is the object in the + + + align:start position:0% +coordinate and what is the object in the +parameter list here what's its + + align:start position:0% +parameter list here what's its + + + align:start position:0% +parameter list here what's its +type + + align:start position:0% +type + + + align:start position:0% +type +coordinate so when we wrote the distance + + align:start position:0% +coordinate so when we wrote the distance + + + align:start position:0% +coordinate so when we wrote the distance +method does it + + align:start position:0% +method does it + + + align:start position:0% +method does it +matter which object we call the method + + align:start position:0% +matter which object we call the method + + + align:start position:0% +matter which object we call the method +on to get the distance between these two + + align:start position:0% +on to get the distance between these two + + + align:start position:0% +on to get the distance between these two +points no right because the distance + + align:start position:0% +points no right because the distance + + + align:start position:0% +points no right because the distance +between say saying I want the distance + + align:start position:0% +between say saying I want the distance + + + align:start position:0% +between say saying I want the distance +between this point and this point is the + + align:start position:0% +between this point and this point is the + + + align:start position:0% +between this point and this point is the +same as saying I want the distance + + align:start position:0% +same as saying I want the distance + + + align:start position:0% +same as saying I want the distance +between this point and this point right + + align:start position:0% +between this point and this point right + + + align:start position:0% +between this point and this point right +it's just the order is + + align:start position:0% +it's just the order is + + + align:start position:0% +it's just the order is +different right so just the way that + + align:start position:0% +different right so just the way that + + + align:start position:0% +different right so just the way that +this distance method works right it + + align:start position:0% +this distance method works right it + + + align:start position:0% +this distance method works right it +doesn't actually matter which object I + + align:start position:0% +doesn't actually matter which object I + + + align:start position:0% +doesn't actually matter which object I +call the method on + + align:start position:0% +call the method on + + + align:start position:0% +call the method on +right as long as they're both coordinate + + align:start position:0% +right as long as they're both coordinate + + + align:start position:0% +right as long as they're both coordinate +objects which they + + align:start position:0% + + + + align:start position:0% + +are does that make sense is that all + + align:start position:0% +are does that make sense is that all + + + align:start position:0% +are does that make sense is that all +right any questions about this for those + + align:start position:0% +right any questions about this for those + + + align:start position:0% +right any questions about this for those +in the not + + align:start position:0% + + + + align:start position:0% + +yeah self do Center self. Center is an + + align:start position:0% +yeah self do Center self. Center is an + + + align:start position:0% +yeah self do Center self. Center is an +object of type coordinate not + + align:start position:0% +object of type coordinate not + + + align:start position:0% +object of type coordinate not +Circle because so self is a + + align:start position:0% +Circle because so self is a + + + align:start position:0% +Circle because so self is a +circle right because self is is talking + + align:start position:0% +circle right because self is is talking + + + align:start position:0% +circle right because self is is talking +about me the class that I'm currently + + align:start position:0% +about me the class that I'm currently + + + align:start position:0% +about me the class that I'm currently +defining and the class I'm currently + + align:start position:0% +defining and the class I'm currently + + + align:start position:0% +defining and the class I'm currently +defining is a + + align:start position:0% +defining is a + + + align:start position:0% +defining is a +circle but self. center right we even + + align:start position:0% +circle but self. center right we even + + + align:start position:0% +circle but self. center right we even +wrote code we would like to enforce that + + align:start position:0% +wrote code we would like to enforce that + + + align:start position:0% +wrote code we would like to enforce that +it is a cord an object + + align:start position:0% + + + + align:start position:0% + +right so we could have put parentheses + + align:start position:0% +right so we could have put parentheses + + + align:start position:0% +right so we could have put parentheses +around this self. Center if we wanted to + + align:start position:0% +around this self. Center if we wanted to + + + align:start position:0% +around this self. Center if we wanted to +and then called the distance on that + + align:start position:0% +and then called the distance on that + + + align:start position:0% +and then called the distance on that +does that make + + align:start position:0% +does that make + + + align:start position:0% +does that make +sense + + align:start position:0% +sense + + + align:start position:0% +sense +okay all right so that's all I had + + align:start position:0% +okay all right so that's all I had + + + align:start position:0% +okay all right so that's all I had +regarding the circle class now we're + + align:start position:0% +regarding the circle class now we're + + + align:start position:0% +regarding the circle class now we're +going to switch gears and we're going to + + align:start position:0% +going to switch gears and we're going to + + + align:start position:0% +going to switch gears and we're going to +look at fractions right so numerator + + align:start position:0% +look at fractions right so numerator + + + align:start position:0% +look at fractions right so numerator +slash denominator situation here so + + align:start position:0% +slash denominator situation here so + + + align:start position:0% +slash denominator situation here so +we're gonna create a new data type to + + align:start position:0% +we're gonna create a new data type to + + + align:start position:0% +we're gonna create a new data type to +represent a number as a fraction so + + align:start position:0% +represent a number as a fraction so + + + align:start position:0% +represent a number as a fraction so +first thing we need to do is make the + + align:start position:0% +first thing we need to do is make the + + + align:start position:0% +first thing we need to do is make the +design decision what data will represent + + align:start position:0% +design decision what data will represent + + + align:start position:0% +design decision what data will represent +our fraction so think about it you guys + + align:start position:0% +our fraction so think about it you guys + + + align:start position:0% +our fraction so think about it you guys +tell me what do you think what's a + + align:start position:0% +tell me what do you think what's a + + + align:start position:0% +tell me what do you think what's a +reasonable set of data that could + + align:start position:0% +reasonable set of data that could + + + align:start position:0% +reasonable set of data that could +represent our number as a + + align:start position:0% +represent our number as a + + + align:start position:0% +represent our number as a +fraction when you think of a + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +yeah a set of two two things maybe + + align:start position:0% +yeah a set of two two things maybe + + + align:start position:0% +yeah a set of two two things maybe +integers right one representing the + + align:start position:0% +integers right one representing the + + + align:start position:0% +integers right one representing the +numerator the thing above the the line + + align:start position:0% +numerator the thing above the the line + + + align:start position:0% +numerator the thing above the the line +and one the denominator the thing below + + align:start position:0% +and one the denominator the thing below + + + align:start position:0% +and one the denominator the thing below +the line good that's exactly what I had + + align:start position:0% +the line good that's exactly what I had + + + align:start position:0% +the line good that's exactly what I had +in mind what are some behaviors of + + align:start position:0% +in mind what are some behaviors of + + + align:start position:0% +in mind what are some behaviors of +fractions you guys tell + + align:start position:0% +fractions you guys tell + + + align:start position:0% +fractions you guys tell +me what should what things should + + align:start position:0% +me what should what things should + + + align:start position:0% +me what should what things should +fractions do + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +yeah yes adding them multiplying + + align:start position:0% +yeah yes adding them multiplying + + + align:start position:0% +yeah yes adding them multiplying +fraction + + align:start position:0% +fraction + + + align:start position:0% +fraction +together dividing them uh inverting a + + align:start position:0% +together dividing them uh inverting a + + + align:start position:0% +together dividing them uh inverting a +fraction also something we could do + + align:start position:0% +fraction also something we could do + + + align:start position:0% +fraction also something we could do +right so one over what it currently is + + align:start position:0% +right so one over what it currently is + + + align:start position:0% +right so one over what it currently is +things like that all right so we're + + align:start position:0% +things like that all right so we're + + + align:start position:0% +things like that all right so we're +going to write it together um the full + + align:start position:0% +going to write it together um the full + + + align:start position:0% +going to write it together um the full +code is actually in the python file so + + align:start position:0% +code is actually in the python file so + + + align:start position:0% +code is actually in the python file so +mostly I'm going to go through the + + align:start position:0% +mostly I'm going to go through the + + + align:start position:0% +mostly I'm going to go through the +slides just because it's incremental so + + align:start position:0% +slides just because it's incremental so + + + align:start position:0% +slides just because it's incremental so +it's easier for me to talk about it um + + align:start position:0% +it's easier for me to talk about it um + + + align:start position:0% +it's easier for me to talk about it um +but you know the exact full code is is + + align:start position:0% +but you know the exact full code is is + + + align:start position:0% +but you know the exact full code is is +already in the in the python file if + + align:start position:0% +already in the in the python file if + + + align:start position:0% +already in the in the python file if +you're running it + + align:start position:0% +you're running it + + + align:start position:0% +you're running it +later so the first thing we're going to + + align:start position:0% +later so the first thing we're going to + + + align:start position:0% +later so the first thing we're going to +do is is create this uh fraction class + + align:start position:0% +do is is create this uh fraction class + + + align:start position:0% +do is is create this uh fraction class +and I'm actually going to name it simple + + align:start position:0% +and I'm actually going to name it simple + + + align:start position:0% +and I'm actually going to name it simple +fraction instead of fraction because + + align:start position:0% +fraction instead of fraction because + + + align:start position:0% +fraction instead of fraction because +we're going to improve upon this simple + + align:start position:0% +we're going to improve upon this simple + + + align:start position:0% +we're going to improve upon this simple +fraction object uh in a little bit so + + align:start position:0% +fraction object uh in a little bit so + + + align:start position:0% +fraction object uh in a little bit so +this one I'm just going to call Simple + + align:start position:0% +this one I'm just going to call Simple + + + align:start position:0% +this one I'm just going to call Simple +fraction uh like before it's parent it + + align:start position:0% +fraction uh like before it's parent it + + + align:start position:0% +fraction uh like before it's parent it +is is the generic python object right so + + align:start position:0% +is is the generic python object right so + + + align:start position:0% +is is the generic python object right so +again very very simple it it um you know + + align:start position:0% +again very very simple it it um you know + + + align:start position:0% +again very very simple it it um you know +it doesn't do anything special yet the + + align:start position:0% +it doesn't do anything special yet the + + + align:start position:0% +it doesn't do anything special yet the +first method we need to write is the + + align:start position:0% +first method we need to write is the + + + align:start position:0% +first method we need to write is the +init method so how do we initialize a + + align:start position:0% +init method so how do we initialize a + + + align:start position:0% +init method so how do we initialize a +fraction object obviously we don't want + + align:start position:0% +fraction object obviously we don't want + + + align:start position:0% +fraction object obviously we don't want +the numerator or the denominator to be + + align:start position:0% +the numerator or the denominator to be + + + align:start position:0% +the numerator or the denominator to be +empty right so when we create a simple + + align:start position:0% +empty right so when we create a simple + + + align:start position:0% +empty right so when we create a simple +fraction object we want the user to tell + + align:start position:0% +fraction object we want the user to tell + + + align:start position:0% +fraction object we want the user to tell +us the values for the numerator and the + + align:start position:0% +us the values for the numerator and the + + + align:start position:0% +us the values for the numerator and the +denominator so those are the two + + align:start position:0% +denominator so those are the two + + + align:start position:0% +denominator so those are the two +parameters that I would love the user to + + align:start position:0% +parameters that I would love the user to + + + align:start position:0% +parameters that I would love the user to +uh to uh initiate this fraction + + align:start position:0% +uh to uh initiate this fraction + + + align:start position:0% +uh to uh initiate this fraction +with and then what are going to uh what + + align:start position:0% +with and then what are going to uh what + + + align:start position:0% +with and then what are going to uh what +will be the two uh data attributes that + + align:start position:0% +will be the two uh data attributes that + + + align:start position:0% +will be the two uh data attributes that +we had decided on well numerator so + + align:start position:0% +we had decided on well numerator so + + + align:start position:0% +we had decided on well numerator so +self. num and self. denom will be the + + align:start position:0% +self. num and self. denom will be the + + + align:start position:0% +self. num and self. denom will be the +two data attributes + + align:start position:0% +two data attributes + + + align:start position:0% +two data attributes +right so self. Nom and self. denom are + + align:start position:0% +right so self. Nom and self. denom are + + + align:start position:0% +right so self. Nom and self. denom are +our data attributes and they're going to + + align:start position:0% +our data attributes and they're going to + + + align:start position:0% +our data attributes and they're going to +be set initially to whatever is passed + + align:start position:0% +be set initially to whatever is passed + + + align:start position:0% +be set initially to whatever is passed +in uh that Constructor uh + + align:start position:0% +in uh that Constructor uh + + + align:start position:0% +in uh that Constructor uh +call okay so far so good let's write a + + align:start position:0% +call okay so far so good let's write a + + + align:start position:0% +call okay so far so good let's write a +method that helps us multiply two + + align:start position:0% +method that helps us multiply two + + + align:start position:0% +method that helps us multiply two +fraction objects together so we'll call + + align:start position:0% +fraction objects together so we'll call + + + align:start position:0% +fraction objects together so we'll call +it + + align:start position:0% +it + + + align:start position:0% +it +times so this times method will be + + align:start position:0% +times so this times method will be + + + align:start position:0% +times so this times method will be +called on an object the thing before the + + align:start position:0% +called on an object the thing before the + + + align:start position:0% +called on an object the thing before the +dot that object that thing before the + + align:start position:0% +dot that object that thing before the + + + align:start position:0% +dot that object that thing before the +dot will get mapped to self and then the + + align:start position:0% +dot will get mapped to self and then the + + + align:start position:0% +dot will get mapped to self and then the +thing in the parentheses the one other + + align:start position:0% +thing in the parentheses the one other + + + align:start position:0% +thing in the parentheses the one other +parameter will be mapped to + + align:start position:0% +parameter will be mapped to + + + align:start position:0% +parameter will be mapped to +OT okay so how do we multiply two + + align:start position:0% +OT okay so how do we multiply two + + + align:start position:0% +OT okay so how do we multiply two +fraction objects together take the + + align:start position:0% +fraction objects together take the + + + align:start position:0% +fraction objects together take the +numerators multiply them take the + + align:start position:0% +numerators multiply them take the + + + align:start position:0% +numerators multiply them take the +denominators multiply them you got your + + align:start position:0% +denominators multiply them you got your + + + align:start position:0% +denominators multiply them you got your +new numerator and you got your new + + align:start position:0% +new numerator and you got your new + + + align:start position:0% +new numerator and you got your new +denominator right so how do we grab the + + align:start position:0% +denominator right so how do we grab the + + + align:start position:0% +denominator right so how do we grab the +numerators of both of these objects so + + align:start position:0% +numerators of both of these objects so + + + align:start position:0% +numerators of both of these objects so +the numerator of the thing before the + + align:start position:0% +the numerator of the thing before the + + + align:start position:0% +the numerator of the thing before the +dot right that maps to self is self. n + + align:start position:0% +dot right that maps to self is self. n + + + align:start position:0% +dot right that maps to self is self. n +and the the numerator of the other + + align:start position:0% +and the the numerator of the other + + + align:start position:0% +and the the numerator of the other +object that's going to be in the par + + align:start position:0% +object that's going to be in the par + + + align:start position:0% +object that's going to be in the par +parameter list is the name of my + + align:start position:0% +parameter list is the name of my + + + align:start position:0% +parameter list is the name of my +parameter otth do their numerator + + align:start position:0% +parameter otth do their numerator + + + align:start position:0% +parameter otth do their numerator +no everyone okay so + + align:start position:0% +no everyone okay so + + + align:start position:0% +no everyone okay so +far yes okay I saw some head knots + + align:start position:0% +far yes okay I saw some head knots + + + align:start position:0% +far yes okay I saw some head knots +that's good the denominator will be the + + align:start position:0% +that's good the denominator will be the + + + align:start position:0% +that's good the denominator will be the +same so my new denominator is just + + align:start position:0% +same so my new denominator is just + + + align:start position:0% +same so my new denominator is just +multiplying my denominator the thing + + align:start position:0% +multiplying my denominator the thing + + + align:start position:0% +multiplying my denominator the thing +before the dot with the thing in the + + align:start position:0% +before the dot with the thing in the + + + align:start position:0% +before the dot with the thing in the +parameter denominator okay so I've got + + align:start position:0% +parameter denominator okay so I've got + + + align:start position:0% +parameter denominator okay so I've got +my new numerator my new denominator and + + align:start position:0% +my new numerator my new denominator and + + + align:start position:0% +my new numerator my new denominator and +all I'm going to do is do the division + + align:start position:0% +all I'm going to do is do the division + + + align:start position:0% +all I'm going to do is do the division +and return this value what's the type of + + align:start position:0% +and return this value what's the type of + + + align:start position:0% +and return this value what's the type of +the return here what's this method going + + align:start position:0% +the return here what's this method going + + + align:start position:0% +the return here what's this method going +to return what + + align:start position:0% +to return what + + + align:start position:0% +to return what +type a float exactly yeah good yep + + align:start position:0% +type a float exactly yeah good yep + + + align:start position:0% +type a float exactly yeah good yep +because all I'm doing is dividing one + + align:start position:0% +because all I'm doing is dividing one + + + align:start position:0% +because all I'm doing is dividing one +number by another + + align:start position:0% + + + + align:start position:0% + +number + + align:start position:0% +number + + + align:start position:0% +number +okay perfect so that's uh what I've + + align:start position:0% +okay perfect so that's uh what I've + + + align:start position:0% +okay perfect so that's uh what I've +already said now we can Define another + + align:start position:0% +already said now we can Define another + + + align:start position:0% +already said now we can Define another +method plus to add two uh two fraction + + align:start position:0% +method plus to add two uh two fraction + + + align:start position:0% +method plus to add two uh two fraction +objects together very similar thing + + align:start position:0% +objects together very similar thing + + + align:start position:0% +objects together very similar thing +except the top is going to be slightly + + align:start position:0% +except the top is going to be slightly + + + align:start position:0% +except the top is going to be slightly +different right you take the numerator + + align:start position:0% +different right you take the numerator + + + align:start position:0% +different right you take the numerator +of one times the denominator of the + + align:start position:0% +of one times the denominator of the + + + align:start position:0% +of one times the denominator of the +other plus the numerator of other times + + align:start position:0% +other plus the numerator of other times + + + align:start position:0% +other plus the numerator of other times +the denominator of the first one the + + align:start position:0% +the denominator of the first one the + + + align:start position:0% +the denominator of the first one the +Cris cross thing the denominator is the + + align:start position:0% +Cris cross thing the denominator is the + + + align:start position:0% +Cris cross thing the denominator is the +same right just multiply the denoms + + align:start position:0% +same right just multiply the denoms + + + align:start position:0% +same right just multiply the denoms +together and again we return the + + align:start position:0% +together and again we return the + + + align:start position:0% +together and again we return the +division Top divid by bottom again the + + align:start position:0% +division Top divid by bottom again the + + + align:start position:0% +division Top divid by bottom again the +uh the return of this method will be a + + align:start position:0% +uh the return of this method will be a + + + align:start position:0% +uh the return of this method will be a +float so even though I'm multiplying or + + align:start position:0% +float so even though I'm multiplying or + + + align:start position:0% +float so even though I'm multiplying or +adding these two fraction objects + + align:start position:0% +adding these two fraction objects + + + align:start position:0% +adding these two fraction objects +together my return will be a float fine + + align:start position:0% +together my return will be a float fine + + + align:start position:0% +together my return will be a float fine +so let's run the code I'm creating two + + align:start position:0% +so let's run the code I'm creating two + + + align:start position:0% +so let's run the code I'm creating two +simple fraction objects first one is + + align:start position:0% +simple fraction objects first one is + + + align:start position:0% +simple fraction objects first one is +going to be accessed using variable + + align:start position:0% +going to be accessed using variable + + + align:start position:0% +going to be accessed using variable +named F1 so this one represents the + + align:start position:0% +named F1 so this one represents the + + + align:start position:0% +named F1 so this one represents the +number 3 + + align:start position:0% +number 3 + + + align:start position:0% +number 3 +over4 second one is accessed by variable + + align:start position:0% +over4 second one is accessed by variable + + + align:start position:0% +over4 second one is accessed by variable +named F2 and this one represents the + + align:start position:0% +named F2 and this one represents the + + + align:start position:0% +named F2 and this one represents the +fraction one over4 + + align:start position:0% +fraction one over4 + + + align:start position:0% +fraction one over4 +okay so now if I access the numer + + align:start position:0% +okay so now if I access the numer + + + align:start position:0% +okay so now if I access the numer +numerator of + + align:start position:0% +numerator of + + + align:start position:0% +numerator of +F1 python says well what's the object + + align:start position:0% +F1 python says well what's the object + + + align:start position:0% +F1 python says well what's the object +before the dot it's F1 so what is your + + align:start position:0% +before the dot it's F1 so what is your + + + align:start position:0% +before the dot it's F1 so what is your +numerator well I set it to three so this + + align:start position:0% +numerator well I set it to three so this + + + align:start position:0% +numerator well I set it to three so this +one tells me it's three right pretty + + align:start position:0% +one tells me it's three right pretty + + + align:start position:0% +one tells me it's three right pretty +simple same thing with the denominator + + align:start position:0% +simple same thing with the denominator + + + align:start position:0% +simple same thing with the denominator +of F1 again it looks at the thing before + + align:start position:0% +of F1 again it looks at the thing before + + + align:start position:0% +of F1 again it looks at the thing before +the dot it's a fraction object it says + + align:start position:0% +the dot it's a fraction object it says + + + align:start position:0% +the dot it's a fraction object it says +do you have a dnom a data attribute you + + align:start position:0% +do you have a dnom a data attribute you + + + align:start position:0% +do you have a dnom a data attribute you +do and its value is four so that's + + align:start position:0% +do and its value is four so that's + + + align:start position:0% +do and its value is four so that's +four now what's the result of fub1 do + + align:start position:0% +four now what's the result of fub1 do + + + align:start position:0% +four now what's the result of fub1 do +plus F2 super weird way to write WR it + + align:start position:0% +plus F2 super weird way to write WR it + + + align:start position:0% +plus F2 super weird way to write WR it +but um it's what we've got so far right + + align:start position:0% +but um it's what we've got so far right + + + align:start position:0% +but um it's what we've got so far right +so the thing before the dot is an + + align:start position:0% +so the thing before the dot is an + + + align:start position:0% +so the thing before the dot is an +object it's a simple fraction + + align:start position:0% +object it's a simple fraction + + + align:start position:0% +object it's a simple fraction +object and the thing before the dot + + align:start position:0% +object and the thing before the dot + + + align:start position:0% +object and the thing before the dot +remember maps to self in my parameter + + align:start position:0% +remember maps to self in my parameter + + + align:start position:0% +remember maps to self in my parameter +list right because this it's just a + + align:start position:0% +list right because this it's just a + + + align:start position:0% +list right because this it's just a +function so like usual functions you + + align:start position:0% +function so like usual functions you + + + align:start position:0% +function so like usual functions you +know a a bunch of lectures ago we + + align:start position:0% +know a a bunch of lectures ago we + + + align:start position:0% +know a a bunch of lectures ago we +basically map the actual parameters when + + align:start position:0% +basically map the actual parameters when + + + align:start position:0% +basically map the actual parameters when +we run the function to the formal + + align:start position:0% +we run the function to the formal + + + align:start position:0% +we run the function to the formal +parameters the things for my function + + align:start position:0% +parameters the things for my function + + + align:start position:0% +parameters the things for my function +definition + + align:start position:0% +definition + + + align:start position:0% +definition +so the actual parameter here for self is + + align:start position:0% +so the actual parameter here for self is + + + align:start position:0% +so the actual parameter here for self is +the thing before the dot F1 and the and + + align:start position:0% +the thing before the dot F1 and the and + + + align:start position:0% +the thing before the dot F1 and the and +the uh and the parameter F2 gets mapped + + align:start position:0% +the uh and the parameter F2 gets mapped + + + align:start position:0% +the uh and the parameter F2 gets mapped +to + + align:start position:0% +to + + + align:start position:0% +to +OT that's how we read that so this is + + align:start position:0% +OT that's how we read that so this is + + + align:start position:0% +OT that's how we read that so this is +just doing the the addition right so + + align:start position:0% +just doing the the addition right so + + + align:start position:0% +just doing the the addition right so +this will give me 1.0 because it's a + + align:start position:0% +this will give me 1.0 because it's a + + + align:start position:0% +this will give me 1.0 because it's a +float same with the times the thing + + align:start position:0% +float same with the times the thing + + + align:start position:0% +float same with the times the thing +before the dot maps to self and every + + align:start position:0% +before the dot maps to self and every + + + align:start position:0% +before the dot maps to self and every +other parameter in the parameter list + + align:start position:0% +other parameter in the parameter list + + + align:start position:0% +other parameter in the parameter list +maps to all everything else except for + + align:start position:0% +maps to all everything else except for + + + align:start position:0% +maps to all everything else except for +self so this one will do 3 over 16 to + + align:start position:0% +self so this one will do 3 over 16 to + + + align:start position:0% +self so this one will do 3 over 16 to +give me + + align:start position:0% + + + + align:start position:0% + +875 okay everyone okay so far the trick + + align:start position:0% +875 okay everyone okay so far the trick + + + align:start position:0% +875 okay everyone okay so far the trick +here is to remember that the thing + + align:start position:0% +here is to remember that the thing + + + align:start position:0% +here is to remember that the thing +before the dot maps to self in the fun + + align:start position:0% +before the dot maps to self in the fun + + + align:start position:0% +before the dot maps to self in the fun +in the method definition and then + + align:start position:0% +in the method definition and then + + + align:start position:0% +in the method definition and then +everything else maps to everything other + + align:start position:0% +everything else maps to everything other + + + align:start position:0% +everything else maps to everything other +than + + align:start position:0% +than + + + align:start position:0% +than +self + + align:start position:0% +self + + + align:start position:0% +self +okay I'm glad everything's okay so far + + align:start position:0% +okay I'm glad everything's okay so far + + + align:start position:0% +okay I'm glad everything's okay so far +because I'm going to get you to write + + align:start position:0% +because I'm going to get you to write + + + align:start position:0% +because I'm going to get you to write +this uh this code here it looks like a + + align:start position:0% +this uh this code here it looks like a + + + align:start position:0% +this uh this code here it looks like a +lot but um the first half of it it is + + align:start position:0% +lot but um the first half of it it is + + + align:start position:0% +lot but um the first half of it it is +just re uh defining the init method for + + align:start position:0% +just re uh defining the init method for + + + align:start position:0% +just re uh defining the init method for +simple fraction I want you to write + + align:start position:0% +simple fraction I want you to write + + + align:start position:0% +simple fraction I want you to write +these two methods and they're going to + + align:start position:0% +these two methods and they're going to + + + align:start position:0% +these two methods and they're going to +be on liners basically so get + + align:start position:0% +be on liners basically so get + + + align:start position:0% +be on liners basically so get +inverse will return something and it + + align:start position:0% +inverse will return something and it + + + align:start position:0% +inverse will return something and it +returns a float representing one over + + align:start position:0% +returns a float representing one over + + + align:start position:0% +returns a float representing one over +myself right so if the input as is in + + align:start position:0% +myself right so if the input as is in + + + align:start position:0% +myself right so if the input as is in +this example here if I have a simple + + align:start position:0% +this example here if I have a simple + + + align:start position:0% +this example here if I have a simple +fraction object representing 3 over + + align:start position:0% +fraction object representing 3 over + + + align:start position:0% +fraction object representing 3 over +4 if I call get inverse on it right here + + align:start position:0% +4 if I call get inverse on it right here + + + align:start position:0% +4 if I call get inverse on it right here +f1. get inverse self becomes F1 and I + + align:start position:0% +f1. get inverse self becomes F1 and I + + + align:start position:0% +f1. get inverse self becomes F1 and I +would like it to return and therefore + + align:start position:0% +would like it to return and therefore + + + align:start position:0% +would like it to return and therefore +print 4 over3 so 1.3 3 3 3 3 3 3 okay + + align:start position:0% +print 4 over3 so 1.3 3 3 3 3 3 3 okay + + + align:start position:0% +print 4 over3 so 1.3 3 3 3 3 3 3 okay +that's get inverse and then invert is a + + align:start position:0% +that's get inverse and then invert is a + + + align:start position:0% +that's get inverse and then invert is a +method that doesn't return anything so + + align:start position:0% +method that doesn't return anything so + + + align:start position:0% +method that doesn't return anything so +it returns none and instead it just + + align:start position:0% +it returns none and instead it just + + + align:start position:0% +it returns none and instead it just +internally switches the numerator and + + align:start position:0% +internally switches the numerator and + + + align:start position:0% +internally switches the numerator and +the denominator of self right so self's + + align:start position:0% +the denominator of self right so self's + + + align:start position:0% +the denominator of self right so self's +numerator becomes whatever its + + align:start position:0% +numerator becomes whatever its + + + align:start position:0% +numerator becomes whatever its +denominator is and the other way around + + align:start position:0% +denominator is and the other way around + + + align:start position:0% +denominator is and the other way around +right so when you call it this one + + align:start position:0% +right so when you call it this one + + + align:start position:0% +right so when you call it this one +doesn't print anything but instead if we + + align:start position:0% +doesn't print anything but instead if we + + + align:start position:0% +doesn't print anything but instead if we +access f1's numerator and denominator + + align:start position:0% +access f1's numerator and denominator + + + align:start position:0% +access f1's numerator and denominator +they will have been + + align:start position:0% +they will have been + + + align:start position:0% +they will have been +switched okay so this is down on + + align:start position:0% +switched okay so this is down on + + + align:start position:0% +switched okay so this is down on +line + + align:start position:0% + + + + align:start position:0% + +133 give you a couple moments and then + + align:start position:0% +133 give you a couple moments and then + + + align:start position:0% +133 give you a couple moments and then +we can write it together should not be a + + align:start position:0% +we can write it together should not be a + + + align:start position:0% +we can write it together should not be a +lot of + + align:start position:0% +lot of + + + align:start position:0% +lot of +code okay how do we write the get + + align:start position:0% +code okay how do we write the get + + + align:start position:0% +code okay how do we write the get +inverse so remember you have to return + + align:start position:0% +inverse so remember you have to return + + + align:start position:0% +inverse so remember you have to return +something how do we return yeah one + + align:start position:0% + + + + align:start position:0% + +over one over + + align:start position:0% +over one over + + + align:start position:0% +over one over +self so remember self is an object of + + align:start position:0% +self so remember self is an object of + + + align:start position:0% +self so remember self is an object of +type simple fraction right so we need to + + align:start position:0% +type simple fraction right so we need to + + + align:start position:0% +type simple fraction right so we need to +manipulate its numerator and the + + align:start position:0% +manipulate its numerator and the + + + align:start position:0% +manipulate its numerator and the +denominator if we want to do the return + + align:start position:0% +denominator if we want to do the return + + + align:start position:0% +denominator if we want to do the return +because if we just do + + align:start position:0% +because if we just do + + + align:start position:0% +because if we just do +this um is it this one yeah this one + + align:start position:0% +this um is it this one yeah this one + + + align:start position:0% +this um is it this one yeah this one +here then python says oh sorry it's + + align:start position:0% +here then python says oh sorry it's + + + align:start position:0% +here then python says oh sorry it's +trying to divide one an integer by an + + align:start position:0% +trying to divide one an integer by an + + + align:start position:0% +trying to divide one an integer by an +object of types simple fraction right + + align:start position:0% +object of types simple fraction right + + + align:start position:0% +object of types simple fraction right +and that's the error that we get here + + align:start position:0% +and that's the error that we get here + + + align:start position:0% +and that's the error that we get here +and it doesn't know how to do a division + + align:start position:0% +and it doesn't know how to do a division + + + align:start position:0% +and it doesn't know how to do a division +between an integer and a simple fraction + + align:start position:0% +between an integer and a simple fraction + + + align:start position:0% +between an integer and a simple fraction +so how can we do that by working with + + align:start position:0% +so how can we do that by working with + + + align:start position:0% +so how can we do that by working with +actual numbers that are part of my + + align:start position:0% +actual numbers that are part of my + + + align:start position:0% +actual numbers that are part of my +simple + + align:start position:0% + + + + align:start position:0% + +fraction anyone + + align:start position:0% + + + + align:start position:0% + +yeah self. denom divided by self. num + + align:start position:0% +yeah self. denom divided by self. num + + + align:start position:0% +yeah self. denom divided by self. num +yep we can do that yep or one over self. + + align:start position:0% +yep we can do that yep or one over self. + + + align:start position:0% +yep we can do that yep or one over self. +num divid by self. D num that's also + + align:start position:0% +num divid by self. D num that's also + + + align:start position:0% +num divid by self. D num that's also +fine yeah but this is a little bit + + align:start position:0% +fine yeah but this is a little bit + + + align:start position:0% +fine yeah but this is a little bit +cleaner so now dnom is an integer right + + align:start position:0% +cleaner so now dnom is an integer right + + + align:start position:0% +cleaner so now dnom is an integer right +because when we create it we pass in int + + align:start position:0% +because when we create it we pass in int + + + align:start position:0% +because when we create it we pass in int +int so Dam and num are integers which + + align:start position:0% +int so Dam and num are integers which + + + align:start position:0% +int so Dam and num are integers which +means that python knows how to do a + + align:start position:0% +means that python knows how to do a + + + align:start position:0% +means that python knows how to do a +division between a number and another + + align:start position:0% +division between a number and another + + + align:start position:0% +division between a number and another +number + + align:start position:0% +number + + + align:start position:0% +number +yeah so if we run that now it prints + + align:start position:0% +yeah so if we run that now it prints + + + align:start position:0% +yeah so if we run that now it prints +1.33333 exactly + + align:start position:0% + + + + align:start position:0% + +okay how do we do the invert function + + align:start position:0% +okay how do we do the invert function + + + align:start position:0% +okay how do we do the invert function +method + + align:start position:0% + + + + align:start position:0% + +sorry sorry go + + align:start position:0% + + + + align:start position:0% + +ahead + + align:start position:0% + + + + align:start position:0% + +yep + + align:start position:0% + + + + align:start position:0% + +yep + + align:start position:0% + + + + align:start position:0% + +like that yeah yep that's one way to do + + align:start position:0% +like that yeah yep that's one way to do + + + align:start position:0% +like that yeah yep that's one way to do +it yep so you can see now accessing the + + align:start position:0% +it yep so you can see now accessing the + + + align:start position:0% +it yep so you can see now accessing the +new numerator and denominator gives me + + align:start position:0% +new numerator and denominator gives me + + + align:start position:0% +new numerator and denominator gives me +four over three any other ways that + + align:start position:0% +four over three any other ways that + + + align:start position:0% +four over three any other ways that +you've done it yeah + + align:start position:0% + + + + align:start position:0% + +I + + align:start position:0% + + + + align:start position:0% + +yep the tupo trick I like + + align:start position:0% +yep the tupo trick I like + + + align:start position:0% +yep the tupo trick I like +it self done + + align:start position:0% +it self done + + + align:start position:0% +it self done +yep perfect + + align:start position:0% + + + + align:start position:0% + +yes oh okay yeah that also works + + align:start position:0% + + + + align:start position:0% + +yeah perfect all all very valid ways of + + align:start position:0% +yeah perfect all all very valid ways of + + + align:start position:0% +yeah perfect all all very valid ways of +of doing it nice yep so notice this + + align:start position:0% +of doing it nice yep so notice this + + + align:start position:0% +of doing it nice yep so notice this +there's no return for this one right I + + align:start position:0% +there's no return for this one right I + + + align:start position:0% +there's no return for this one right I +didn't want to return anything python + + align:start position:0% +didn't want to return anything python + + + align:start position:0% +didn't want to return anything python +will automatically return none and these + + align:start position:0% +will automatically return none and these + + + align:start position:0% +will automatically return none and these +internal uh numerator and denominators + + align:start position:0% +internal uh numerator and denominators + + + align:start position:0% +internal uh numerator and denominators +will have been flipped + + align:start position:0% +will have been flipped + + + align:start position:0% +will have been flipped +perfect questions about this + + align:start position:0% +perfect questions about this + + + align:start position:0% +perfect questions about this +code + + align:start position:0% +code + + + align:start position:0% +code +okay so let's try it out a little bit + + align:start position:0% +okay so let's try it out a little bit + + + align:start position:0% +okay so let's try it out a little bit +more so here I've got these two uh + + align:start position:0% +more so here I've got these two uh + + + align:start position:0% +more so here I've got these two uh +additions right so um this is exactly + + align:start position:0% +additions right so um this is exactly + + + align:start position:0% +additions right so um this is exactly +what we had previously the exact same + + align:start position:0% +what we had previously the exact same + + + align:start position:0% +what we had previously the exact same +code code what's weird though and you + + align:start position:0% +code code what's weird though and you + + + align:start position:0% +code code what's weird though and you +might have been um uh weirded out by + + align:start position:0% +might have been um uh weirded out by + + + align:start position:0% +might have been um uh weirded out by +this too when we first ran it is I am + + align:start position:0% +this too when we first ran it is I am + + + align:start position:0% +this too when we first ran it is I am +doing operations with two fraction + + align:start position:0% +doing operations with two fraction + + + align:start position:0% +doing operations with two fraction +objects and yet the plus and the m and + + align:start position:0% +objects and yet the plus and the m and + + + align:start position:0% +objects and yet the plus and the m and +the times methods give me floats which + + align:start position:0% +the times methods give me floats which + + + align:start position:0% +the times methods give me floats which +is a little weird right ideally if we're + + align:start position:0% +is a little weird right ideally if we're + + + align:start position:0% +is a little weird right ideally if we're +working with fraction objects I would + + align:start position:0% +working with fraction objects I would + + + align:start position:0% +working with fraction objects I would +like the return to also be a fraction + + align:start position:0% +like the return to also be a fraction + + + align:start position:0% +like the return to also be a fraction +object so I can then work with more + + align:start position:0% +object so I can then work with more + + + align:start position:0% +object so I can then work with more +fraction objects later on that's one + + align:start position:0% +fraction objects later on that's one + + + align:start position:0% +fraction objects later on that's one +weird thing another weird thing is if if + + align:start position:0% +weird thing another weird thing is if if + + + align:start position:0% +weird thing another weird thing is if if +we then print one of our objects that + + align:start position:0% +we then print one of our objects that + + + align:start position:0% +we then print one of our objects that +we've created F1 in this case we use + + align:start position:0% +we've created F1 in this case we use + + + align:start position:0% +we've created F1 in this case we use +print statements often right to debug + + align:start position:0% +print statements often right to debug + + + align:start position:0% +print statements often right to debug +and things like that if I use the print + + align:start position:0% +and things like that if I use the print + + + align:start position:0% +and things like that if I use the print +statement on an object of type that I've + + align:start position:0% +statement on an object of type that I've + + + align:start position:0% +statement on an object of type that I've +created in this case a simple fraction + + align:start position:0% +created in this case a simple fraction + + + align:start position:0% +created in this case a simple fraction +python spits this + + align:start position:0% +python spits this + + + align:start position:0% +python spits this +out it says hey your object is an object + + align:start position:0% +out it says hey your object is an object + + + align:start position:0% +out it says hey your object is an object +of type simple fraction at this memory + + align:start position:0% +of type simple fraction at this memory + + + align:start position:0% +of type simple fraction at this memory +location no thank you that's not very + + align:start position:0% +location no thank you that's not very + + + align:start position:0% +location no thank you that's not very +useful to me right what I'd like to know + + align:start position:0% +useful to me right what I'd like to know + + + align:start position:0% +useful to me right what I'd like to know +is maybe a nice represent of my fraction + + align:start position:0% +is maybe a nice represent of my fraction + + + align:start position:0% +is maybe a nice represent of my fraction +object like + + align:start position:0% +object like + + + align:start position:0% +object like +34 right I don't care about what memory + + align:start position:0% +34 right I don't care about what memory + + + align:start position:0% +34 right I don't care about what memory +location it's at and one more thing we'd + + align:start position:0% +location it's at and one more thing we'd + + + align:start position:0% +location it's at and one more thing we'd +like to try to do this is a class that + + align:start position:0% +like to try to do this is a class that + + + align:start position:0% +like to try to do this is a class that +that represents something numerical so + + align:start position:0% +that represents something numerical so + + + align:start position:0% +that represents something numerical so +something that people might + + align:start position:0% +something that people might + + + align:start position:0% +something that people might +instinctually want to do is to use + + align:start position:0% +instinctually want to do is to use + + + align:start position:0% +instinctually want to do is to use +operators like the star or the Plus or + + align:start position:0% +operators like the star or the Plus or + + + align:start position:0% +operators like the star or the Plus or +the slash right to divide add multiply + + align:start position:0% +the slash right to divide add multiply + + + align:start position:0% +the slash right to divide add multiply +these fraction things but if we run the + + align:start position:0% +these fraction things but if we run the + + + align:start position:0% +these fraction things but if we run the +star operator between object of type + + align:start position:0% +star operator between object of type + + + align:start position:0% +star operator between object of type +simple fraction right times another + + align:start position:0% +simple fraction right times another + + + align:start position:0% +simple fraction right times another +object times of type simple fraction + + align:start position:0% +object times of type simple fraction + + + align:start position:0% +object times of type simple fraction +python gives us an error um and I'll + + align:start position:0% +python gives us an error um and I'll + + + align:start position:0% +python gives us an error um and I'll +even show you the + + align:start position:0% +even show you the + + + align:start position:0% +even show you the +error + + align:start position:0% +error + + + align:start position:0% +error +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +so + + align:start position:0% +so + + + align:start position:0% +so +here right so here I am printing my + + align:start position:0% +here right so here I am printing my + + + align:start position:0% +here right so here I am printing my +object right so it spits this out which + + align:start position:0% +object right so it spits this out which + + + align:start position:0% +object right so it spits this out which +is fine but not what I want this one you + + align:start position:0% +is fine but not what I want this one you + + + align:start position:0% +is fine but not what I want this one you +know obviously we've seen this it + + align:start position:0% +know obviously we've seen this it + + + align:start position:0% +know obviously we've seen this it +already prints this out and then if I + + align:start position:0% +already prints this out and then if I + + + align:start position:0% +already prints this out and then if I +try to multiply my two simple fraction + + align:start position:0% +try to multiply my two simple fraction + + + align:start position:0% +try to multiply my two simple fraction +object objects together it says I don't + + align:start position:0% +object objects together it says I don't + + + align:start position:0% +object objects together it says I don't +know how to do that right so it's + + align:start position:0% +know how to do that right so it's + + + align:start position:0% +know how to do that right so it's +unsupported operan types so the operant + + align:start position:0% +unsupported operan types so the operant + + + align:start position:0% +unsupported operan types so the operant +simple fraction and simple fraction are + + align:start position:0% +simple fraction and simple fraction are + + + align:start position:0% +simple fraction and simple fraction are +not supported with the star operator + + align:start position:0% +not supported with the star operator + + + align:start position:0% +not supported with the star operator +well no surprise there how is python + + align:start position:0% +well no surprise there how is python + + + align:start position:0% +well no surprise there how is python +supposed to know how to multiply two + + align:start position:0% +supposed to know how to multiply two + + + align:start position:0% +supposed to know how to multiply two +simple fraction objects together right + + align:start position:0% +simple fraction objects together right + + + align:start position:0% +simple fraction objects together right +right before I even ran this program I + + align:start position:0% +right before I even ran this program I + + + align:start position:0% +right before I even ran this program I +didn't even know what a simple fraction + + align:start position:0% +didn't even know what a simple fraction + + + align:start position:0% +didn't even know what a simple fraction +object was right so we need to tell it + + align:start position:0% +object was right so we need to tell it + + + align:start position:0% +object was right so we need to tell it +all of these + + align:start position:0% +all of these + + + align:start position:0% +all of these +details and we will do just that + + align:start position:0% +details and we will do just that + + + align:start position:0% +details and we will do just that +so all of these um uh operators print + + align:start position:0% +so all of these um uh operators print + + + align:start position:0% +so all of these um uh operators print +Len that we've been using Star ad right + + align:start position:0% +Len that we've been using Star ad right + + + align:start position:0% +Len that we've been using Star ad right +less than greater than even the square + + align:start position:0% +less than greater than even the square + + + align:start position:0% +less than greater than even the square +brackets to index into something these + + align:start position:0% +brackets to index into something these + + + align:start position:0% +brackets to index into something these +are actually shorthand notations right + + align:start position:0% +are actually shorthand notations right + + + align:start position:0% +are actually shorthand notations right +they're really common operations that + + align:start position:0% +they're really common operations that + + + align:start position:0% +they're really common operations that +you want to do and python lets you use + + align:start position:0% +you want to do and python lets you use + + + align:start position:0% +you want to do and python lets you use +these common operations in instead of + + align:start position:0% +these common operations in instead of + + + align:start position:0% +these common operations in instead of +writing these really verbose function + + align:start position:0% +writing these really verbose function + + + align:start position:0% +writing these really verbose function +names but really behind the + + align:start position:0% +names but really behind the + + + align:start position:0% +names but really behind the +scenes all of these shorthand operations + + align:start position:0% +scenes all of these shorthand operations + + + align:start position:0% +scenes all of these shorthand operations +actually run a + + align:start position:0% +actually run a + + + align:start position:0% +actually run a +method okay again not a secret I'm not + + align:start position:0% +method okay again not a secret I'm not + + + align:start position:0% +method okay again not a secret I'm not +lowering my voice because it's a secret + + align:start position:0% +lowering my voice because it's a secret + + + align:start position:0% +lowering my voice because it's a secret +but it's just it's really cool so all of + + align:start position:0% +but it's just it's really cool so all of + + + align:start position:0% +but it's just it's really cool so all of +these operations like the multiplication + + align:start position:0% +these operations like the multiplication + + + align:start position:0% +these operations like the multiplication +or the print statement just gets + + align:start position:0% +or the print statement just gets + + + align:start position:0% +or the print statement just gets +replaced with a method okay and the + + align:start position:0% +replaced with a method okay and the + + + align:start position:0% +replaced with a method okay and the +method names look like this they are + + align:start position:0% +method names look like this they are + + + align:start position:0% +method names look like this they are +Dunder methods just like the init method + + align:start position:0% +Dunder methods just like the init method + + + align:start position:0% +Dunder methods just like the init method +was a special method that python ran + + align:start position:0% +was a special method that python ran + + + align:start position:0% +was a special method that python ran +when something special happened like + + align:start position:0% +when something special happened like + + + align:start position:0% +when something special happened like +you're creating an object + + align:start position:0% +you're creating an object + + + align:start position:0% +you're creating an object +well when something special happens like + + align:start position:0% +well when something special happens like + + + align:start position:0% +well when something special happens like +you're using the plus operator between + + align:start position:0% +you're using the plus operator between + + + align:start position:0% +you're using the plus operator between +an object of your type and something + + align:start position:0% +an object of your type and something + + + align:start position:0% +an object of your type and something +else python will also run this special + + align:start position:0% +else python will also run this special + + + align:start position:0% +else python will also run this special +Dunder method behind the scenes right + + align:start position:0% +Dunder method behind the scenes right + + + align:start position:0% +Dunder method behind the scenes right +and same here if I want to multiply my + + align:start position:0% +and same here if I want to multiply my + + + align:start position:0% +and same here if I want to multiply my +object with something else python will + + align:start position:0% +object with something else python will + + + align:start position:0% +object with something else python will +run this special Dunder method behind + + align:start position:0% +run this special Dunder method behind + + + align:start position:0% +run this special Dunder method behind +the scenes if I want to print an object + + align:start position:0% +the scenes if I want to print an object + + + align:start position:0% +the scenes if I want to print an object +of my type python will run this special + + align:start position:0% +of my type python will run this special + + + align:start position:0% +of my type python will run this special +Dunder method behind the scenes right um + + align:start position:0% +Dunder method behind the scenes right um + + + align:start position:0% +Dunder method behind the scenes right um +even something like casting if I want to + + align:start position:0% +even something like casting if I want to + + + align:start position:0% +even something like casting if I want to +cast my object to to a float or to a + + align:start position:0% +cast my object to to a float or to a + + + align:start position:0% +cast my object to to a float or to a +string or something python will run this + + align:start position:0% +string or something python will run this + + + align:start position:0% +string or something python will run this +special Dunder method behind the scenes + + align:start position:0% +special Dunder method behind the scenes + + + align:start position:0% +special Dunder method behind the scenes +um and then you know there's a whole + + align:start position:0% +um and then you know there's a whole + + + align:start position:0% +um and then you know there's a whole +bunch of other ones even indexing into a + + align:start position:0% +bunch of other ones even indexing into a + + + align:start position:0% +bunch of other ones even indexing into a +list or sorry not a list indexing into + + align:start position:0% +list or sorry not a list indexing into + + + align:start position:0% +list or sorry not a list indexing into +an object of your type so if you make an + + align:start position:0% +an object of your type so if you make an + + + align:start position:0% +an object of your type so if you make an +object like a q or a stack where you + + align:start position:0% +object like a q or a stack where you + + + align:start position:0% +object like a q or a stack where you +know you have a bunch of sequences of + + align:start position:0% +know you have a bunch of sequences of + + + align:start position:0% +know you have a bunch of sequences of +objects you can tell python how to index + + align:start position:0% +objects you can tell python how to index + + + align:start position:0% +objects you can tell python how to index +into an object of your type into an + + align:start position:0% +into an object of your type into an + + + align:start position:0% +into an object of your type into an +object that's a q right so all of these + + align:start position:0% +object that's a q right so all of these + + + align:start position:0% +object that's a q right so all of these +things uh um all of these methods need + + align:start position:0% +things uh um all of these methods need + + + align:start position:0% +things uh um all of these methods need +to be implemented somewhere now most of + + align:start position:0% +to be implemented somewhere now most of + + + align:start position:0% +to be implemented somewhere now most of +them are not implemented in the basic uh + + align:start position:0% +them are not implemented in the basic uh + + + align:start position:0% +them are not implemented in the basic uh +python object except for the Str Str so + + align:start position:0% +python object except for the Str Str so + + + align:start position:0% +python object except for the Str Str so +the Str Str method actually just prints + + align:start position:0% +the Str Str method actually just prints + + + align:start position:0% +the Str Str method actually just prints +the memory location of this object + + align:start position:0% +the memory location of this object + + + align:start position:0% +the memory location of this object +that's exactly what we had seen right by + + align:start position:0% +that's exactly what we had seen right by + + + align:start position:0% +that's exactly what we had seen right by +the default Behavior but none of these + + align:start position:0% +the default Behavior but none of these + + + align:start position:0% +the default Behavior but none of these +other ones are really implemented and so + + align:start position:0% +other ones are really implemented and so + + + align:start position:0% +other ones are really implemented and so +if you want the object that you're + + align:start position:0% +if you want the object that you're + + + align:start position:0% +if you want the object that you're +currently writing to work with the star + + align:start position:0% +currently writing to work with the star + + + align:start position:0% +currently writing to work with the star +or the Plus or the double equal sign to + + align:start position:0% +or the Plus or the double equal sign to + + + align:start position:0% +or the Plus or the double equal sign to +test for test for equality between this + + align:start position:0% +test for test for equality between this + + + align:start position:0% +test for test for equality between this +object and and something else you have + + align:start position:0% +object and and something else you have + + + align:start position:0% +object and and something else you have +to write the method in your class + + align:start position:0% +to write the method in your class + + + align:start position:0% +to write the method in your class +definition okay so you have to implement + + align:start position:0% +definition okay so you have to implement + + + align:start position:0% +definition okay so you have to implement +it to tell python that this is what you + + align:start position:0% +it to tell python that this is what you + + + align:start position:0% +it to tell python that this is what you +want to do when somebody uses this + + align:start position:0% +want to do when somebody uses this + + + align:start position:0% +want to do when somebody uses this +special shorthand notation so let's + + align:start position:0% +special shorthand notation so let's + + + align:start position:0% +special shorthand notation so let's +start with the print because it's the + + align:start position:0% +start with the print because it's the + + + align:start position:0% +start with the print because it's the +most basic thing you will probably want + + align:start position:0% +most basic thing you will probably want + + + align:start position:0% +most basic thing you will probably want +to implement when you create a new data + + align:start position:0% +to implement when you create a new data + + + align:start position:0% +to implement when you create a new data +type right for debugging purposes you'll + + align:start position:0% +type right for debugging purposes you'll + + + align:start position:0% +type right for debugging purposes you'll +find yourself Instinct saying hey print + + align:start position:0% +find yourself Instinct saying hey print + + + align:start position:0% +find yourself Instinct saying hey print +you know F1 to print this fraction + + align:start position:0% +you know F1 to print this fraction + + + align:start position:0% +you know F1 to print this fraction +object to see what it looks like and so + + align:start position:0% +object to see what it looks like and so + + + align:start position:0% +object to see what it looks like and so +the Str Str method is one of the really + + align:start position:0% +the Str Str method is one of the really + + + align:start position:0% +the Str Str method is one of the really +basic things you should Implement right + + align:start position:0% +basic things you should Implement right + + + align:start position:0% +basic things you should Implement right +after the inip + + align:start position:0% +after the inip + + + align:start position:0% +after the inip +method okay so let's look at it in the + + align:start position:0% +method okay so let's look at it in the + + + align:start position:0% +method okay so let's look at it in the +context of the coordinate object so here + + align:start position:0% +context of the coordinate object so here + + + align:start position:0% +context of the coordinate object so here +I've got my coordinate object 3 comma 4 + + align:start position:0% +I've got my coordinate object 3 comma 4 + + + align:start position:0% +I've got my coordinate object 3 comma 4 +and even when I print this coordinate + + align:start position:0% +and even when I print this coordinate + + + align:start position:0% +and even when I print this coordinate +object python tells me this uh still un + + align:start position:0% +object python tells me this uh still un + + + align:start position:0% +object python tells me this uh still un +informative message that this object is + + align:start position:0% +informative message that this object is + + + align:start position:0% +informative message that this object is +of type coordinate at this memory + + align:start position:0% +of type coordinate at this memory + + + align:start position:0% +of type coordinate at this memory +location okay I don't care well instead + + align:start position:0% +location okay I don't care well instead + + + align:start position:0% +location okay I don't care well instead +what I would really like to do is say + + align:start position:0% +what I would really like to do is say + + + align:start position:0% +what I would really like to do is say +hey I want to represent a coordinate + + align:start position:0% +hey I want to represent a coordinate + + + align:start position:0% +hey I want to represent a coordinate +object by something like this angle + + align:start position:0% +object by something like this angle + + + align:start position:0% +object by something like this angle +bracket the value of the x coordinate + + align:start position:0% +bracket the value of the x coordinate + + + align:start position:0% +bracket the value of the x coordinate +comma the value of the y-coordinate + + align:start position:0% +comma the value of the y-coordinate + + + align:start position:0% +comma the value of the y-coordinate +close angle + + align:start position:0% +close angle + + + align:start position:0% +close angle +bracket right so that would be a far + + align:start position:0% +bracket right so that would be a far + + + align:start position:0% +bracket right so that would be a far +more informative print statement than + + align:start position:0% +more informative print statement than + + + align:start position:0% +more informative print statement than +what memory location this thing is at + + align:start position:0% +what memory location this thing is at + + + align:start position:0% +what memory location this thing is at +right so let's do that well here we are + + align:start position:0% +right so let's do that well here we are + + + align:start position:0% +right so let's do that well here we are +uh our our our um our coordinate object + + align:start position:0% +uh our our our um our coordinate object + + + align:start position:0% +uh our our our um our coordinate object +the distance the init like we had before + + align:start position:0% +the distance the init like we had before + + + align:start position:0% +the distance the init like we had before +and here I'm defining my Str Str method + + align:start position:0% +and here I'm defining my Str Str method + + + align:start position:0% +and here I'm defining my Str Str method +right so double Str + + align:start position:0% +right so double Str + + + align:start position:0% +right so double Str +strore no other parameters except for + + align:start position:0% +strore no other parameters except for + + + align:start position:0% +strore no other parameters except for +self so me calling this method on an + + align:start position:0% +self so me calling this method on an + + + align:start position:0% +self so me calling this method on an +object and what is this uh going to do + + align:start position:0% +object and what is this uh going to do + + + align:start position:0% +object and what is this uh going to do +it will return not + + align:start position:0% +it will return not + + + align:start position:0% +it will return not +print return a + + align:start position:0% +print return a + + + align:start position:0% +print return a +string and the string is going to + + align:start position:0% +string and the string is going to + + + align:start position:0% +string and the string is going to +represent the thing you want to be + + align:start position:0% +represent the thing you want to be + + + align:start position:0% +represent the thing you want to be +printed out right so it returns a string + + align:start position:0% +printed out right so it returns a string + + + align:start position:0% +printed out right so it returns a string +doesn't print it however you want to + + align:start position:0% +doesn't print it however you want to + + + align:start position:0% +doesn't print it however you want to +make up the string is up to you so here + + align:start position:0% +make up the string is up to you so here + + + align:start position:0% +make up the string is up to you so here +I've just used concatenation of a bunch + + align:start position:0% +I've just used concatenation of a bunch + + + align:start position:0% +I've just used concatenation of a bunch +of stuff so I'm concatenating the angle + + align:start position:0% +of stuff so I'm concatenating the angle + + + align:start position:0% +of stuff so I'm concatenating the angle +bracket with uh the x value of my + + align:start position:0% +bracket with uh the x value of my + + + align:start position:0% +bracket with uh the x value of my +current object cast to a string + + align:start position:0% +current object cast to a string + + + align:start position:0% +current object cast to a string +concatenated with the comma concatenated + + align:start position:0% +concatenated with the comma concatenated + + + align:start position:0% +concatenated with the comma concatenated +with the Y value of my current object + + align:start position:0% +with the Y value of my current object + + + align:start position:0% +with the Y value of my current object +cast to a string concatenated with the + + align:start position:0% +cast to a string concatenated with the + + + align:start position:0% +cast to a string concatenated with the +closed angle bracket right that's the + + align:start position:0% +closed angle bracket right that's the + + + align:start position:0% +closed angle bracket right that's the +design decision we made to um for how a + + align:start position:0% +design decision we made to um for how a + + + align:start position:0% +design decision we made to um for how a +coordinate object should be + + align:start position:0% +coordinate object should be + + + align:start position:0% +coordinate object should be +printed everyone okay so + + align:start position:0% +printed everyone okay so + + + align:start position:0% +printed everyone okay so +far + + align:start position:0% +far + + + align:start position:0% +far +okay so if you want to use an F string + + align:start position:0% +okay so if you want to use an F string + + + align:start position:0% +okay so if you want to use an F string +to make up this thing to return totally + + align:start position:0% +to make up this thing to return totally + + + align:start position:0% +to make up this thing to return totally +fine if you want to make a variable + + align:start position:0% +fine if you want to make a variable + + + align:start position:0% +fine if you want to make a variable +right in between the return and the + + align:start position:0% +right in between the return and the + + + align:start position:0% +right in between the return and the +definition here that you just keep + + align:start position:0% +definition here that you just keep + + + align:start position:0% +definition here that you just keep +concatenating with so you can + + align:start position:0% +concatenating with so you can + + + align:start position:0% +concatenating with so you can +concatenate it with new lines and things + + align:start position:0% +concatenate it with new lines and things + + + align:start position:0% +concatenate it with new lines and things +like that also totally fine at the end + + align:start position:0% +like that also totally fine at the end + + + align:start position:0% +like that also totally fine at the end +you just have to return that string that + + align:start position:0% +you just have to return that string that + + + align:start position:0% +you just have to return that string that +represents the thing you want to pre + + align:start position:0% +represents the thing you want to pre + + + align:start position:0% +represents the thing you want to pre +print it + + align:start position:0% +print it + + + align:start position:0% +print it +out so now let's see what happens when + + align:start position:0% +out so now let's see what happens when + + + align:start position:0% +out so now let's see what happens when +we actually run the the code right so + + align:start position:0% +we actually run the the code right so + + + align:start position:0% +we actually run the the code right so +here I'm creating a coordinate object + + align:start position:0% +here I'm creating a coordinate object + + + align:start position:0% +here I'm creating a coordinate object +and then I'm printing that coordinate + + align:start position:0% +and then I'm printing that coordinate + + + align:start position:0% +and then I'm printing that coordinate +object well python says hey you just + + align:start position:0% +object well python says hey you just + + + align:start position:0% +object well python says hey you just +called a special shorthand notation on + + align:start position:0% +called a special shorthand notation on + + + align:start position:0% +called a special shorthand notation on +an object of type coordinate let me see + + align:start position:0% +an object of type coordinate let me see + + + align:start position:0% +an object of type coordinate let me see +if you implemented the St Str method it + + align:start position:0% +if you implemented the St Str method it + + + align:start position:0% +if you implemented the St Str method it +looks in the class definition it sees + + align:start position:0% +looks in the class definition it sees + + + align:start position:0% +looks in the class definition it sees +the Str Str method implemented here and + + align:start position:0% +the Str Str method implemented here and + + + align:start position:0% +the Str Str method implemented here and +then it runs the code inside and says Ah + + align:start position:0% +then it runs the code inside and says Ah + + + align:start position:0% +then it runs the code inside and says Ah +you want to grab C's x value and C's yv + + align:start position:0% +you want to grab C's x value and C's yv + + + align:start position:0% +you want to grab C's x value and C's yv +value and concatenated with these things + + align:start position:0% +value and concatenated with these things + + + align:start position:0% +value and concatenated with these things +here sure I can do that for you and then + + align:start position:0% +here sure I can do that for you and then + + + align:start position:0% +here sure I can do that for you and then +it goes and prints this out to the + + align:start position:0% +it goes and prints this out to the + + + align:start position:0% +it goes and prints this out to the +screen okay very cool right now we can + + align:start position:0% +screen okay very cool right now we can + + + align:start position:0% +screen okay very cool right now we can +decide how to print objects that we + + align:start position:0% +decide how to print objects that we + + + align:start position:0% +decide how to print objects that we +create all right so let's try to wrap + + align:start position:0% +create all right so let's try to wrap + + + align:start position:0% +create all right so let's try to wrap +our minds around types here okay so if + + align:start position:0% +our minds around types here okay so if + + + align:start position:0% +our minds around types here okay so if +we print this + + align:start position:0% +we print this + + + align:start position:0% +we print this +c c is an instance of a coordinate + + align:start position:0% +c c is an instance of a coordinate + + + align:start position:0% +c c is an instance of a coordinate +object right it's it's it's it's a it's + + align:start position:0% +object right it's it's it's it's a it's + + + align:start position:0% +object right it's it's it's it's a it's +it's an actual object that we're + + align:start position:0% +it's an actual object that we're + + + align:start position:0% +it's an actual object that we're +manipulating it's not the class + + align:start position:0% +manipulating it's not the class + + + align:start position:0% +manipulating it's not the class +definition it's not anything abstract + + align:start position:0% +definition it's not anything abstract + + + align:start position:0% +definition it's not anything abstract +like that it's an actual object like the + + align:start position:0% +like that it's an actual object like the + + + align:start position:0% +like that it's an actual object like the +integer three right is an actual + + align:start position:0% +integer three right is an actual + + + align:start position:0% +integer three right is an actual +object so if we print that C python uses + + align:start position:0% +object so if we print that C python uses + + + align:start position:0% +object so if we print that C python uses +the Str strr method well what if we + + align:start position:0% +the Str strr method well what if we + + + align:start position:0% +the Str strr method well what if we +print the type of C somebody tell me + + align:start position:0% +print the type of C somebody tell me + + + align:start position:0% +print the type of C somebody tell me +what's the type of + + align:start position:0% + + + + align:start position:0% + +C coordinate yeah it's the class name + + align:start position:0% +C coordinate yeah it's the class name + + + align:start position:0% +C coordinate yeah it's the class name +that we defined so when we print the + + align:start position:0% +that we defined so when we print the + + + align:start position:0% +that we defined so when we print the +type of C python says this is a class + + align:start position:0% +type of C python says this is a class + + + align:start position:0% +type of C python says this is a class +coordinate which makes sense because if + + align:start position:0% +coordinate which makes sense because if + + + align:start position:0% +coordinate which makes sense because if +we just replace type of C here with what + + align:start position:0% +we just replace type of C here with what + + + align:start position:0% +we just replace type of C here with what +it is coordinate we'll get the same + + align:start position:0% +it is coordinate we'll get the same + + + align:start position:0% +it is coordinate we'll get the same +print statement if we just print + + align:start position:0% +print statement if we just print + + + align:start position:0% +print statement if we just print +coordinate python says this is a class + + align:start position:0% +coordinate python says this is a class + + + align:start position:0% +coordinate python says this is a class +of type coordinate right so those two + + align:start position:0% +of type coordinate right so those two + + + align:start position:0% +of type coordinate right so those two +lines are equivalent and then let me + + align:start position:0% +lines are equivalent and then let me + + + align:start position:0% +lines are equivalent and then let me +blow your minds a little bit more what + + align:start position:0% +blow your minds a little bit more what + + + align:start position:0% +blow your minds a little bit more what +if we print the type of coordinate well + + align:start position:0% +if we print the type of coordinate well + + + align:start position:0% +if we print the type of coordinate well +what is + + align:start position:0% +what is + + + align:start position:0% +what is +coordinate it's a + + align:start position:0% + + + + align:start position:0% + +type right we're defining a new type in + + align:start position:0% +type right we're defining a new type in + + + align:start position:0% +type right we're defining a new type in +Python called a coordinate so coordinate + + align:start position:0% +Python called a coordinate so coordinate + + + align:start position:0% +Python called a coordinate so coordinate +is a new data type in Python so it's + + align:start position:0% +is a new data type in Python so it's + + + align:start position:0% +is a new data type in Python so it's +type + + align:start position:0% +type + + + align:start position:0% +type +is + + align:start position:0% + + + + align:start position:0% + +type okay so every everything in Python + + align:start position:0% +type okay so every everything in Python + + + align:start position:0% +type okay so every everything in Python +is an object even + + align:start position:0% +is an object even + + + align:start position:0% +is an object even +types okay one more thing so we've used + + align:start position:0% +types okay one more thing so we've used + + + align:start position:0% +types okay one more thing so we've used +um the type of something equals + + align:start position:0% +um the type of something equals + + + align:start position:0% +um the type of something equals +something else right when we check that + + align:start position:0% +something else right when we check that + + + align:start position:0% +something else right when we check that +the type of uh the the circle's Center + + align:start position:0% +the type of uh the the circle's Center + + + align:start position:0% +the type of uh the the circle's Center +was a coordinate that's one way to check + + align:start position:0% +was a coordinate that's one way to check + + + align:start position:0% +was a coordinate that's one way to check +for types another way is to use this is + + align:start position:0% +for types another way is to use this is + + + align:start position:0% +for types another way is to use this is +instance function just as an aside so + + align:start position:0% +instance function just as an aside so + + + align:start position:0% +instance function just as an aside so +you can um check that uh C is an + + align:start position:0% +you can um check that uh C is an + + + align:start position:0% +you can um check that uh C is an +instance of type coordinate uh by using + + align:start position:0% +instance of type coordinate uh by using + + + align:start position:0% +instance of type coordinate uh by using +this is instance method and you know + + align:start position:0% +this is instance method and you know + + + align:start position:0% +this is instance method and you know +this will tell you true and you know + + align:start position:0% +this will tell you true and you know + + + align:start position:0% +this will tell you true and you know +just to draw a parallel you can say you + + align:start position:0% +just to draw a parallel you can say you + + + align:start position:0% +just to draw a parallel you can say you +know is instance three comma int that + + align:start position:0% +know is instance three comma int that + + + align:start position:0% +know is instance three comma int that +would also say true right because three + + align:start position:0% +would also say true right because three + + + align:start position:0% +would also say true right because three +is an object of type integer it's just + + align:start position:0% +is an object of type integer it's just + + + align:start position:0% +is an object of type integer it's just +another way to check for + + align:start position:0% +another way to check for + + + align:start position:0% +another way to check for +types okay so the remainder of this + + align:start position:0% +types okay so the remainder of this + + + align:start position:0% +types okay so the remainder of this +class I would like to go back to our + + align:start position:0% +class I would like to go back to our + + + align:start position:0% +class I would like to go back to our +fraction + + align:start position:0% +fraction + + + align:start position:0% +fraction +class and make it + + align:start position:0% +class and make it + + + align:start position:0% +class and make it +better now that we know uh Dunder + + align:start position:0% +better now that we know uh Dunder + + + align:start position:0% +better now that we know uh Dunder +methods right let's Implement a whole + + align:start position:0% +methods right let's Implement a whole + + + align:start position:0% +methods right let's Implement a whole +bunch of Dunder methods methods to help + + align:start position:0% +bunch of Dunder methods methods to help + + + align:start position:0% +bunch of Dunder methods methods to help +us um to help us and and people who want + + align:start position:0% +us um to help us and and people who want + + + align:start position:0% +us um to help us and and people who want +to use our class use it in a more + + align:start position:0% +to use our class use it in a more + + + align:start position:0% +to use our class use it in a more +efficient way right so we're going to + + align:start position:0% +efficient way right so we're going to + + + align:start position:0% +efficient way right so we're going to +implement the star operator the plus + + align:start position:0% +implement the star operator the plus + + + align:start position:0% +implement the star operator the plus +operator we're going to implement the + + align:start position:0% +operator we're going to implement the + + + align:start position:0% +operator we're going to implement the +print and then we're going to implement + + align:start position:0% +print and then we're going to implement + + + align:start position:0% +print and then we're going to implement +uh Implement uh converting to a + + align:start position:0% +uh Implement uh converting to a + + + align:start position:0% +uh Implement uh converting to a +float all right so the first thing that + + align:start position:0% +float all right so the first thing that + + + align:start position:0% +float all right so the first thing that +we should probably add is the strr + + align:start position:0% +we should probably add is the strr + + + align:start position:0% +we should probably add is the strr +method right because then it will help + + align:start position:0% +method right because then it will help + + + align:start position:0% +method right because then it will help +us in debugging when we print an object + + align:start position:0% +us in debugging when we print an object + + + align:start position:0% +us in debugging when we print an object +of type + + align:start position:0% +of type + + + align:start position:0% +of type +fraction so let's define double uncore + + align:start position:0% +fraction so let's define double uncore + + + align:start position:0% +fraction so let's define double uncore +store right again no parameters except + + align:start position:0% +store right again no parameters except + + + align:start position:0% +store right again no parameters except +for self because that's the the uh the + + align:start position:0% +for self because that's the the uh the + + + align:start position:0% +for self because that's the the uh the +method we're the object we're calling + + align:start position:0% +method we're the object we're calling + + + align:start position:0% +method we're the object we're calling +this method + + align:start position:0% +this method + + + align:start position:0% +this method +on and again however you want to uh form + + align:start position:0% +on and again however you want to uh form + + + align:start position:0% +on and again however you want to uh form +this string is up to you you can use f + + align:start position:0% +this string is up to you you can use f + + + align:start position:0% +this string is up to you you can use f +strings or a variable that you keep uh + + align:start position:0% +strings or a variable that you keep uh + + + align:start position:0% +strings or a variable that you keep uh +adding on to um I just did it straight + + align:start position:0% +adding on to um I just did it straight + + + align:start position:0% +adding on to um I just did it straight +in here with concatenation so I've got + + align:start position:0% +in here with concatenation so I've got + + + align:start position:0% +in here with concatenation so I've got +the numerator slash the denominator as a + + align:start position:0% +the numerator slash the denominator as a + + + align:start position:0% +the numerator slash the denominator as a +very reasonable way to represent a + + align:start position:0% +very reasonable way to represent a + + + align:start position:0% +very reasonable way to represent a +string right so three slash four as 3 + + align:start position:0% + + + + align:start position:0% + +over4 okay so one thing I guess to keep + + align:start position:0% +over4 okay so one thing I guess to keep + + + align:start position:0% +over4 okay so one thing I guess to keep +keep keep track of is if you're + + align:start position:0% +keep keep track of is if you're + + + align:start position:0% +keep keep track of is if you're +concatenating you just have to remember + + align:start position:0% +concatenating you just have to remember + + + align:start position:0% +concatenating you just have to remember +to cast the strings right if it's a + + align:start position:0% +to cast the strings right if it's a + + + align:start position:0% +to cast the strings right if it's a +number that or something that's not a + + align:start position:0% +number that or something that's not a + + + align:start position:0% +number that or something that's not a +string so let's try it out I've got + + align:start position:0% +string so let's try it out I've got + + + align:start position:0% +string so let's try it out I've got +three fraction objects here okay so the + + align:start position:0% +three fraction objects here okay so the + + + align:start position:0% +three fraction objects here okay so the +first two we've already seen so I've got + + align:start position:0% +first two we've already seen so I've got + + + align:start position:0% +first two we've already seen so I've got +a fraction representing 3 over4 a + + align:start position:0% +a fraction representing 3 over4 a + + + align:start position:0% +a fraction representing 3 over4 a +fraction representing 1 over4 and F3 is + + align:start position:0% +fraction representing 1 over4 and F3 is + + + align:start position:0% +fraction representing 1 over4 and F3 is +now going to be a fraction representing + + align:start position:0% +now going to be a fraction representing + + + align:start position:0% +now going to be a fraction representing +5 over + + align:start position:0% +5 over + + + align:start position:0% +5 over +one okay if we print F1 again python + + align:start position:0% +one okay if we print F1 again python + + + align:start position:0% +one okay if we print F1 again python +asks hey did you implement an Str Str + + align:start position:0% +asks hey did you implement an Str Str + + + align:start position:0% +asks hey did you implement an Str Str +method in your class + + align:start position:0% +method in your class + + + align:start position:0% +method in your class +definition yes you did good job let me + + align:start position:0% +definition yes you did good job let me + + + align:start position:0% +definition yes you did good job let me +use it so then it uses this right so it + + align:start position:0% +use it so then it uses this right so it + + + align:start position:0% +use it so then it uses this right so it +grabs the numerator of F1 slash the + + align:start position:0% +grabs the numerator of F1 slash the + + + align:start position:0% +grabs the numerator of F1 slash the +numerator of sorry the denominator of F1 + + align:start position:0% +numerator of sorry the denominator of F1 + + + align:start position:0% +numerator of sorry the denominator of F1 +so this will print three the numerator + + align:start position:0% +so this will print three the numerator + + + align:start position:0% +so this will print three the numerator +of F1 slash the denominator of + + align:start position:0% +of F1 slash the denominator of + + + align:start position:0% +of F1 slash the denominator of +fub1 okay same with F2 except that now + + align:start position:0% +fub1 okay same with F2 except that now + + + align:start position:0% +fub1 okay same with F2 except that now +it's going to grab f 2's numerator and + + align:start position:0% +it's going to grab f 2's numerator and + + + align:start position:0% +it's going to grab f 2's numerator and +denominator + + align:start position:0% +denominator + + + align:start position:0% +denominator +one4 so notice now it's not doing the + + align:start position:0% +one4 so notice now it's not doing the + + + align:start position:0% +one4 so notice now it's not doing the +divisions like it did before or sorry + + align:start position:0% +divisions like it did before or sorry + + + align:start position:0% +divisions like it did before or sorry +never mind we're not there yet there's + + align:start position:0% +never mind we're not there yet there's + + + align:start position:0% +never mind we're not there yet there's +nothing to divide it's just grabbing the + + align:start position:0% +nothing to divide it's just grabbing the + + + align:start position:0% +nothing to divide it's just grabbing the +numerators and denominators and just + + align:start position:0% +numerators and denominators and just + + + align:start position:0% +numerators and denominators and just +printing them out right it's not doing + + align:start position:0% +printing them out right it's not doing + + + align:start position:0% +printing them out right it's not doing +any divisions now when we print five uh + + align:start position:0% +any divisions now when we print five uh + + + align:start position:0% +any divisions now when we print five uh +the the the uh the fraction object + + align:start position:0% +the the the uh the fraction object + + + align:start position:0% +the the the uh the fraction object +representing five over one it prints + + align:start position:0% +representing five over one it prints + + + align:start position:0% +representing five over one it prints +fiveash one + + align:start position:0% +fiveash one + + + align:start position:0% +fiveash one +I don't like that because it looks weird + + align:start position:0% +I don't like that because it looks weird + + + align:start position:0% +I don't like that because it looks weird +right do you like that no so then I'm + + align:start position:0% +right do you like that no so then I'm + + + align:start position:0% +right do you like that no so then I'm +gonna have you fix + + align:start position:0% +gonna have you fix + + + align:start position:0% +gonna have you fix +it um change the Str Str method just a + + align:start position:0% +it um change the Str Str method just a + + + align:start position:0% +it um change the Str Str method just a +little + + align:start position:0% +little + + + align:start position:0% +little +bit such that if the denominator is + + align:start position:0% +bit such that if the denominator is + + + align:start position:0% +bit such that if the denominator is +one just have it print the numerator + + align:start position:0% +one just have it print the numerator + + + align:start position:0% +one just have it print the numerator +right and otherwise the representation + + align:start position:0% +right and otherwise the representation + + + align:start position:0% +right and otherwise the representation +should be as before numerator SL + + align:start position:0% +should be as before numerator SL + + + align:start position:0% +should be as before numerator SL +denominator okay + + align:start position:0% + + + + align:start position:0% + +so this should be down + + align:start position:0% +so this should be down + + + align:start position:0% +so this should be down +line + + align:start position:0% +line + + + align:start position:0% +line +14 where is + + align:start position:0% + + + + align:start position:0% + +it very far down + + align:start position:0% + + + + align:start position:0% + +265 okay anyone have some code for + + align:start position:0% + + + + align:start position:0% + +me + + align:start position:0% + + + + align:start position:0% + +yes + + align:start position:0% + + + + align:start position:0% + +yep yep we can do an else that else is + + align:start position:0% +yep yep we can do an else that else is + + + align:start position:0% +yep yep we can do an else that else is +not needed I don't think because if we + + align:start position:0% +not needed I don't think because if we + + + align:start position:0% +not needed I don't think because if we +dropped into the if we just immediately + + align:start position:0% +dropped into the if we just immediately + + + align:start position:0% +dropped into the if we just immediately +return otherwise we would just do the + + align:start position:0% +return otherwise we would just do the + + + align:start position:0% +return otherwise we would just do the +the remaining thing but perfectly fine + + align:start position:0% +the remaining thing but perfectly fine + + + align:start position:0% +the remaining thing but perfectly fine +yep and let's run + + align:start position:0% + + + + align:start position:0% + +it right so the a is a fraction + + align:start position:0% +it right so the a is a fraction + + + align:start position:0% +it right so the a is a fraction +representing one over four so it nicely + + align:start position:0% +representing one over four so it nicely + + + align:start position:0% +representing one over four so it nicely +printed one over four and B the fraction + + align:start position:0% +printed one over four and B the fraction + + + align:start position:0% +printed one over four and B the fraction +3 over one is just printing three + + align:start position:0% +3 over one is just printing three + + + align:start position:0% +3 over one is just printing three +good questions about this + + align:start position:0% +good questions about this + + + align:start position:0% +good questions about this +code okay for the remaining lecture + + align:start position:0% +code okay for the remaining lecture + + + align:start position:0% +code okay for the remaining lecture +though we're not going to use this + + align:start position:0% +though we're not going to use this + + + align:start position:0% +though we're not going to use this +modified this nicer better Str Str + + align:start position:0% +modified this nicer better Str Str + + + align:start position:0% +modified this nicer better Str Str +method so let's just forget what we just + + align:start position:0% +method so let's just forget what we just + + + align:start position:0% +method so let's just forget what we just +did and just remember that it looks like + + align:start position:0% +did and just remember that it looks like + + + align:start position:0% +did and just remember that it looks like +this okay just yeah okay so now let's + + align:start position:0% +this okay just yeah okay so now let's + + + align:start position:0% +this okay just yeah okay so now let's +implement the dunder methods for + + align:start position:0% +implement the dunder methods for + + + align:start position:0% +implement the dunder methods for +addition multiplication division things + + align:start position:0% +addition multiplication division things + + + align:start position:0% +addition multiplication division things +like that so I'm going to do the + + align:start position:0% +like that so I'm going to do the + + + align:start position:0% +like that so I'm going to do the +multiplication just because it's not as + + align:start position:0% +multiplication just because it's not as + + + align:start position:0% +multiplication just because it's not as +long for the numerator so just + + align:start position:0% +long for the numerator so just + + + align:start position:0% +long for the numerator so just +convenience factor here the left hand + + align:start position:0% +convenience factor here the left hand + + + align:start position:0% +convenience factor here the left hand +side I've got our old simple fraction + + align:start position:0% +side I've got our old simple fraction + + + align:start position:0% +side I've got our old simple fraction +code and the right hand side has my new + + align:start position:0% +code and the right hand side has my new + + + align:start position:0% +code and the right hand side has my new +fraction code okay so the old simple + + align:start position:0% +fraction code okay so the old simple + + + align:start position:0% +fraction code okay so the old simple +fraction code remember had this times + + align:start position:0% +fraction code remember had this times + + + align:start position:0% +fraction code remember had this times +method that uh took in an OT it + + align:start position:0% +method that uh took in an OT it + + + align:start position:0% +method that uh took in an OT it +calculated a new numerator and a new + + align:start position:0% +calculated a new numerator and a new + + + align:start position:0% +calculated a new numerator and a new +denominator and returned this okay now + + align:start position:0% +denominator and returned this okay now + + + align:start position:0% +denominator and returned this okay now +my new fraction code will no longer need + + align:start position:0% +my new fraction code will no longer need + + + align:start position:0% +my new fraction code will no longer need +to call times right so we're not even + + align:start position:0% +to call times right so we're not even + + + align:start position:0% +to call times right so we're not even +going to implement a method called times + + align:start position:0% +going to implement a method called times + + + align:start position:0% +going to implement a method called times +instead we're going to uh implement the + + align:start position:0% +instead we're going to uh implement the + + + align:start position:0% +instead we're going to uh implement the +method behind the scenes for the + + align:start position:0% +method behind the scenes for the + + + align:start position:0% +method behind the scenes for the +shorthand notation star to multiply two + + align:start position:0% +shorthand notation star to multiply two + + + align:start position:0% +shorthand notation star to multiply two +fraction fraction objects so we need to + + align:start position:0% +fraction fraction objects so we need to + + + align:start position:0% +fraction fraction objects so we need to +implement DF dcore M dou underscore + + align:start position:0% +implement DF dcore M dou underscore + + + align:start position:0% +implement DF dcore M dou underscore +parameter list is the same because we + + align:start position:0% +parameter list is the same because we + + + align:start position:0% +parameter list is the same because we +still have a thing before the star and a + + align:start position:0% +still have a thing before the star and a + + + align:start position:0% +still have a thing before the star and a +thing after the star as the two fraction + + align:start position:0% +thing after the star as the two fraction + + + align:start position:0% +thing after the star as the two fraction +object we'd like to + + align:start position:0% +object we'd like to + + + align:start position:0% +object we'd like to +multiply within the code itself the new + + align:start position:0% +multiply within the code itself the new + + + align:start position:0% +multiply within the code itself the new +calculations of the new numerator and + + align:start position:0% +calculations of the new numerator and + + + align:start position:0% +calculations of the new numerator and +the new denominator are the same as well + + align:start position:0% +the new denominator are the same as well + + + align:start position:0% +the new denominator are the same as well +right we're still grabbing the + + align:start position:0% +right we're still grabbing the + + + align:start position:0% +right we're still grabbing the +numerators of self and other the + + align:start position:0% +numerators of self and other the + + + align:start position:0% +numerators of self and other the +denominators of self and other + + align:start position:0% +denominators of self and other + + + align:start position:0% +denominators of self and other +multiplying those together right + + align:start position:0% +multiplying those together right + + + align:start position:0% +multiplying those together right +what's different is in the returns right + + align:start position:0% +what's different is in the returns right + + + align:start position:0% +what's different is in the returns right +what was the return type for the uh the + + align:start position:0% +what was the return type for the uh the + + + align:start position:0% +what was the return type for the uh the +times + + align:start position:0% + + + + align:start position:0% + +method a decimal yeah a float exactly + + align:start position:0% +method a decimal yeah a float exactly + + + align:start position:0% +method a decimal yeah a float exactly +what's the return type of my + + align:start position:0% +what's the return type of my + + + align:start position:0% +what's the return type of my +new method the + + align:start position:0% +new method the + + + align:start position:0% +new method the +mole a fraction exactly so yes I'm + + align:start position:0% +mole a fraction exactly so yes I'm + + + align:start position:0% +mole a fraction exactly so yes I'm +operating with fraction objects so I'm + + align:start position:0% +operating with fraction objects so I'm + + + align:start position:0% +operating with fraction objects so I'm +expecting that the return type of this + + align:start position:0% +expecting that the return type of this + + + align:start position:0% +expecting that the return type of this +method the star double mole is also a + + align:start position:0% +method the star double mole is also a + + + align:start position:0% +method the star double mole is also a +fraction object so then I can just keep + + align:start position:0% +fraction object so then I can just keep + + + align:start position:0% +fraction object so then I can just keep +working with fraction objects throughout + + align:start position:0% +working with fraction objects throughout + + + align:start position:0% +working with fraction objects throughout +my code not having to worry about + + align:start position:0% +my code not having to worry about + + + align:start position:0% +my code not having to worry about +whether this thing is now a float or not + + align:start position:0% +whether this thing is now a float or not + + + align:start position:0% +whether this thing is now a float or not +right so how are we creating this + + align:start position:0% +right so how are we creating this + + + align:start position:0% +right so how are we creating this +fraction object well just like we would + + align:start position:0% +fraction object well just like we would + + + align:start position:0% +fraction object well just like we would +create a regular fraction object up in + + align:start position:0% +create a regular fraction object up in + + + align:start position:0% +create a regular fraction object up in +you know the previous slides right so + + align:start position:0% +you know the previous slides right so + + + align:start position:0% +you know the previous slides right so +here right here's an example of us + + align:start position:0% +here right here's an example of us + + + align:start position:0% +here right here's an example of us +creating a new fraction object right + + align:start position:0% +creating a new fraction object right + + + align:start position:0% +creating a new fraction object right +numerator one denominator uh four well + + align:start position:0% +numerator one denominator uh four well + + + align:start position:0% +numerator one denominator uh four well +same here this method me will return a + + align:start position:0% +same here this method me will return a + + + align:start position:0% +same here this method me will return a +new fraction object whose numerator is + + align:start position:0% +new fraction object whose numerator is + + + align:start position:0% +new fraction object whose numerator is +the thing that I just calculated the top + + align:start position:0% +the thing that I just calculated the top + + + align:start position:0% +the thing that I just calculated the top +and the denominator is the thing that I + + align:start position:0% +and the denominator is the thing that I + + + align:start position:0% +and the denominator is the thing that I +just calculated + + align:start position:0% +just calculated + + + align:start position:0% +just calculated +bottom does that make + + align:start position:0% + + + + align:start position:0% + +sense + + align:start position:0% +sense + + + align:start position:0% +sense +okay so this one returns a float this + + align:start position:0% +okay so this one returns a float this + + + align:start position:0% +okay so this one returns a float this +one returns a fraction okay let's run it + + align:start position:0% +one returns a fraction okay let's run it + + + align:start position:0% +one returns a fraction okay let's run it +so a is fraction one over4 B is a + + align:start position:0% +so a is fraction one over4 B is a + + + align:start position:0% +so a is fraction one over4 B is a +fraction representing 3 over four good + + align:start position:0% +fraction representing 3 over four good + + + align:start position:0% +fraction representing 3 over four good +those are the numbers we've been working + + align:start position:0% +those are the numbers we've been working + + + align:start position:0% +those are the numbers we've been working +with if we print a the print statement + + align:start position:0% +with if we print a the print statement + + + align:start position:0% +with if we print a the print statement +says this is the fraction object 1 sl4 + + align:start position:0% +says this is the fraction object 1 sl4 + + + align:start position:0% +says this is the fraction object 1 sl4 +right whose representation is one sl4 + + align:start position:0% +right whose representation is one sl4 + + + align:start position:0% +right whose representation is one sl4 +now if I use the star operator between A + + align:start position:0% +now if I use the star operator between A + + + align:start position:0% +now if I use the star operator between A +and B the thing before the star is kind + + align:start position:0% +and B the thing before the star is kind + + + align:start position:0% +and B the thing before the star is kind +of like the thing before the dot it's + + align:start position:0% +of like the thing before the dot it's + + + align:start position:0% +of like the thing before the dot it's +the self it gets mapped to self in my + + align:start position:0% +the self it gets mapped to self in my + + + align:start position:0% +the self it gets mapped to self in my +double uncore Mo and the thing after the + + align:start position:0% +double uncore Mo and the thing after the + + + align:start position:0% +double uncore Mo and the thing after the +star right the second parameter so to + + align:start position:0% +star right the second parameter so to + + + align:start position:0% +star right the second parameter so to +speak is the uh is the is is the one + + align:start position:0% +speak is the uh is the is is the one + + + align:start position:0% +speak is the uh is the is is the one +parameter that my method takes right + + align:start position:0% +parameter that my method takes right + + + align:start position:0% +parameter that my method takes right +other + + align:start position:0% +other + + + align:start position:0% +other +so this will create will run the mole + + align:start position:0% +so this will create will run the mole + + + align:start position:0% +so this will create will run the mole +method behind the scenes right so python + + align:start position:0% +method behind the scenes right so python + + + align:start position:0% +method behind the scenes right so python +when it sees that star asks do you have + + align:start position:0% +when it sees that star asks do you have + + + align:start position:0% +when it sees that star asks do you have +a mole method implemented in your class + + align:start position:0% +a mole method implemented in your class + + + align:start position:0% +a mole method implemented in your class +fraction because the thing before the + + align:start position:0% +fraction because the thing before the + + + align:start position:0% +fraction because the thing before the +star is a fraction object yes we do what + + align:start position:0% +star is a fraction object yes we do what + + + align:start position:0% +star is a fraction object yes we do what +does it return well it does the + + align:start position:0% +does it return well it does the + + + align:start position:0% +does it return well it does the +multiplication and in the end the return + + align:start position:0% +multiplication and in the end the return + + + align:start position:0% +multiplication and in the end the return +of this method is this thing here right + + align:start position:0% +of this method is this thing here right + + + align:start position:0% +of this method is this thing here right +so I literally just you know made this + + align:start position:0% +so I literally just you know made this + + + align:start position:0% +so I literally just you know made this +uh I guess copied this from the return + + align:start position:0% +uh I guess copied this from the return + + + align:start position:0% +uh I guess copied this from the return +using the numbers of A and B so it + + align:start position:0% +using the numbers of A and B so it + + + align:start position:0% +using the numbers of A and B so it +creates a new fraction object whose + + align:start position:0% +creates a new fraction object whose + + + align:start position:0% +creates a new fraction object whose +numerator is three and denominator is + + align:start position:0% +numerator is three and denominator is + + + align:start position:0% +numerator is three and denominator is +16 so C equals fraction parentheses 3 + + align:start position:0% +16 so C equals fraction parentheses 3 + + + align:start position:0% +16 so C equals fraction parentheses 3 +comma 16 basically just another fraction + + align:start position:0% +comma 16 basically just another fraction + + + align:start position:0% +comma 16 basically just another fraction +object so now when I print + + align:start position:0% +object so now when I print + + + align:start position:0% +object so now when I print +C it's going to use the Str Str method + + align:start position:0% +C it's going to use the Str Str method + + + align:start position:0% +C it's going to use the Str Str method +for a fraction object right because C is + + align:start position:0% +for a fraction object right because C is + + + align:start position:0% +for a fraction object right because C is +a fraction object right there right + + align:start position:0% +a fraction object right there right + + + align:start position:0% +a fraction object right there right +that's exactly what C was so this will + + align:start position:0% +that's exactly what C was so this will + + + align:start position:0% +that's exactly what C was so this will +also print the way we asked to print + + align:start position:0% +also print the way we asked to print + + + align:start position:0% +also print the way we asked to print +fraction objects numerator SL + + align:start position:0% +fraction objects numerator SL + + + align:start position:0% +fraction objects numerator SL +denominator + + align:start position:0% + + + + align:start position:0% + +3/16 everyone okay so + + align:start position:0% + + + + align:start position:0% + +far okay so the following lines are all + + align:start position:0% +far okay so the following lines are all + + + align:start position:0% +far okay so the following lines are all +equivalent okay um using the shorthand + + align:start position:0% +equivalent okay um using the shorthand + + + align:start position:0% +equivalent okay um using the shorthand +notation very nice very pythonic way to + + align:start position:0% +notation very nice very pythonic way to + + + align:start position:0% +notation very nice very pythonic way to +multiply two fractions together but + + align:start position:0% +multiply two fractions together but + + + align:start position:0% +multiply two fractions together but +behind the scenes this is just running a + + align:start position:0% +behind the scenes this is just running a + + + align:start position:0% +behind the scenes this is just running a +method + + align:start position:0% +method + + + align:start position:0% +method +so of course if you really want to you + + align:start position:0% +so of course if you really want to you + + + align:start position:0% +so of course if you really want to you +can just use the same old way of calling + + align:start position:0% +can just use the same old way of calling + + + align:start position:0% +can just use the same old way of calling +a method right thing before the dot dot + + align:start position:0% +a method right thing before the dot dot + + + align:start position:0% +a method right thing before the dot dot +method name parentheses parameter + + align:start position:0% +method name parentheses parameter + + + align:start position:0% +method name parentheses parameter +list so here thing before the dot is a + + align:start position:0% +list so here thing before the dot is a + + + align:start position:0% +list so here thing before the dot is a +DOT the name of my method Dore Moore + + align:start position:0% +DOT the name of my method Dore Moore + + + align:start position:0% +DOT the name of my method Dore Moore +parentheses all of the parameter list + + align:start position:0% +parentheses all of the parameter list + + + align:start position:0% +parentheses all of the parameter list +except for the thing I'm calling it on + + align:start position:0% +except for the thing I'm calling it on + + + align:start position:0% +except for the thing I'm calling it on +right so those two are equivalent and of + + align:start position:0% +right so those two are equivalent and of + + + align:start position:0% +right so those two are equivalent and of +course last time I mentioned uh s sort + + align:start position:0% +course last time I mentioned uh s sort + + + align:start position:0% +course last time I mentioned uh s sort +of a way to hopefully + + align:start position:0% +of a way to hopefully + + + align:start position:0% +of a way to hopefully +demystify um running these methods where + + align:start position:0% +demystify um running these methods where + + + align:start position:0% +demystify um running these methods where +you know the self becomes this thing + + align:start position:0% +you know the self becomes this thing + + + align:start position:0% +you know the self becomes this thing +before the dot you could call the method + + align:start position:0% +before the dot you could call the method + + + align:start position:0% +before the dot you could call the method +on the name of your data type right the + + align:start position:0% +on the name of your data type right the + + + align:start position:0% +on the name of your data type right the +the type that you're currently creating + + align:start position:0% +the type that you're currently creating + + + align:start position:0% +the type that you're currently creating +fraction so fraction is not an instance + + align:start position:0% +fraction so fraction is not an instance + + + align:start position:0% +fraction so fraction is not an instance +right a was an instance it was an actual + + align:start position:0% +right a was an instance it was an actual + + + align:start position:0% +right a was an instance it was an actual +object that we created but fraction is + + align:start position:0% +object that we created but fraction is + + + align:start position:0% +object that we created but fraction is +just the name of my class so if you call + + align:start position:0% +just the name of my class so if you call + + + align:start position:0% +just the name of my class so if you call +the method on the name of your class + + align:start position:0% +the method on the name of your class + + + align:start position:0% +the method on the name of your class +then python expects the full parameter + + align:start position:0% +then python expects the full parameter + + + align:start position:0% +then python expects the full parameter +list right so something for self + + align:start position:0% +list right so something for self + + + align:start position:0% +list right so something for self +something for others something for + + align:start position:0% +something for others something for + + + align:start position:0% +something for others something for +whatever parameters you have and so + + align:start position:0% +whatever parameters you have and so + + + align:start position:0% +whatever parameters you have and so +there we would explicitly pass in both A + + align:start position:0% +there we would explicitly pass in both A + + + align:start position:0% +there we would explicitly pass in both A +and B as part of my parameter list + + align:start position:0% +and B as part of my parameter list + + + align:start position:0% +and B as part of my parameter list +because the thing before the dot is not + + align:start position:0% +because the thing before the dot is not + + + align:start position:0% +because the thing before the dot is not +an object so there's no there it doesn't + + align:start position:0% +an object so there's no there it doesn't + + + align:start position:0% +an object so there's no there it doesn't +map it to self okay but I would never + + align:start position:0% +map it to self okay but I would never + + + align:start position:0% +map it to self okay but I would never +ever + + align:start position:0% +ever + + + align:start position:0% +ever +ever uh run a line of code like this + + align:start position:0% +ever uh run a line of code like this + + + align:start position:0% +ever uh run a line of code like this +this last one here right this is just + + align:start position:0% +this last one here right this is just + + + align:start position:0% +this last one here right this is just +for your information it's non pythonic + + align:start position:0% +for your information it's non pythonic + + + align:start position:0% +for your information it's non pythonic +it's just very verbose right and so this + + align:start position:0% +it's just very verbose right and so this + + + align:start position:0% +it's just very verbose right and so this +uh these uh these Dunder methods help us + + align:start position:0% +uh these uh these Dunder methods help us + + + align:start position:0% +uh these uh these Dunder methods help us +abstract away a bunch of these details + + align:start position:0% +abstract away a bunch of these details + + + align:start position:0% +abstract away a bunch of these details +right so how annoying would it be to + + align:start position:0% +right so how annoying would it be to + + + align:start position:0% +right so how annoying would it be to +always use dot notation when we want to + + align:start position:0% +always use dot notation when we want to + + + align:start position:0% +always use dot notation when we want to +multiply an integer with another integer + + align:start position:0% +multiply an integer with another integer + + + align:start position:0% +multiply an integer with another integer +can you imagine constantly writing three + + align:start position:0% +can you imagine constantly writing three + + + align:start position:0% +can you imagine constantly writing three +do square m Square + + align:start position:0% +do square m Square + + + align:start position:0% +do square m Square +4 that would be very bad code it would + + align:start position:0% +4 that would be very bad code it would + + + align:start position:0% +4 that would be very bad code it would +take forever to read right and so we're + + align:start position:0% +take forever to read right and so we're + + + align:start position:0% +take forever to read right and so we're +abstracting away all the details for + + align:start position:0% +abstracting away all the details for + + + align:start position:0% +abstracting away all the details for +calling these methods into these nice + + align:start position:0% +calling these methods into these nice + + + align:start position:0% +calling these methods into these nice +low shorthand notations and as I said + + align:start position:0% +low shorthand notations and as I said + + + align:start position:0% +low shorthand notations and as I said +the shorthand notations exist for a lot + + align:start position:0% +the shorthand notations exist for a lot + + + align:start position:0% +the shorthand notations exist for a lot +of different operations we saw print you + + align:start position:0% +of different operations we saw print you + + + align:start position:0% +of different operations we saw print you +can do length comparisons like equality + + align:start position:0% +can do length comparisons like equality + + + align:start position:0% +can do length comparisons like equality +even you know indexing into things you + + align:start position:0% +even you know indexing into things you + + + align:start position:0% +even you know indexing into things you +can always you can abstract all of those + + align:start position:0% +can always you can abstract all of those + + + align:start position:0% +can always you can abstract all of those +away um with into shorthand notations + + align:start position:0% +away um with into shorthand notations + + + align:start position:0% +away um with into shorthand notations +and behind the scenes these methods will + + align:start position:0% +and behind the scenes these methods will + + + align:start position:0% +and behind the scenes these methods will +be + + align:start position:0% +be + + + align:start position:0% +be +run okay so big idea right exactly what + + align:start position:0% +run okay so big idea right exactly what + + + align:start position:0% +run okay so big idea right exactly what +I said all these Special Operations that + + align:start position:0% +I said all these Special Operations that + + + align:start position:0% +I said all these Special Operations that +we've been using + + align:start position:0% +we've been using + + + align:start position:0% +we've been using +already behind the scenes these methods + + align:start position:0% +already behind the scenes these methods + + + align:start position:0% +already behind the scenes these methods +get run and these methods were written + + align:start position:0% +get run and these methods were written + + + align:start position:0% +get run and these methods were written +inside the class definition for the + + align:start position:0% +inside the class definition for the + + + align:start position:0% +inside the class definition for the +types that we've been using right so + + align:start position:0% +types that we've been using right so + + + align:start position:0% +types that we've been using right so +when we index into a list L square + + align:start position:0% +when we index into a list L square + + + align:start position:0% +when we index into a list L square +brackets three or whatever there's a + + align:start position:0% +brackets three or whatever there's a + + + align:start position:0% +brackets three or whatever there's a +method being called behind the scenes in + + align:start position:0% +method being called behind the scenes in + + + align:start position:0% +method being called behind the scenes in +the list class to grab the element at + + align:start position:0% +the list class to grab the element at + + + align:start position:0% +the list class to grab the element at +index three I don't remember the dunder + + align:start position:0% +index three I don't remember the dunder + + + align:start position:0% +index three I don't remember the dunder +method name for that but probably like + + align:start position:0% +method name for that but probably like + + + align:start position:0% +method name for that but probably like +double uncore index double uncore I + + align:start position:0% +double uncore index double uncore I + + + align:start position:0% +double uncore index double uncore I +don't know but there is some method + + align:start position:0% +don't know but there is some method + + + align:start position:0% +don't know but there is some method +behind the + + align:start position:0% +behind the + + + align:start position:0% +behind the +scenes all right let's do a couple more + + align:start position:0% +scenes all right let's do a couple more + + + align:start position:0% +scenes all right let's do a couple more +things sorry + + align:start position:0% +things sorry + + + align:start position:0% +things sorry +forget the D name for something is way + + align:start position:0% +forget the D name for something is way + + + align:start position:0% +forget the D name for something is way +to ask python uh you can't ask python + + align:start position:0% +to ask python uh you can't ask python + + + align:start position:0% +to ask python uh you can't ask python +but you can look at the documentation I + + align:start position:0% +but you can look at the documentation I + + + align:start position:0% +but you can look at the documentation I +think it's uh like in python.org there's + + align:start position:0% +think it's uh like in python.org there's + + + align:start position:0% +think it's uh like in python.org there's +a website that lists basically + + align:start position:0% +a website that lists basically + + + align:start position:0% +a website that lists basically +everything that you can that's a Dunder + + align:start position:0% +everything that you can that's a Dunder + + + align:start position:0% +everything that you can that's a Dunder +method yeah under categories like in all + + align:start position:0% +method yeah under categories like in all + + + align:start position:0% +method yeah under categories like in all +the indexing type stuff all the + + align:start position:0% +the indexing type stuff all the + + + align:start position:0% +the indexing type stuff all the +numerical type stuff + + align:start position:0% + + + + align:start position:0% + +yeah um okay so let's do one more thing + + align:start position:0% +yeah um okay so let's do one more thing + + + align:start position:0% +yeah um okay so let's do one more thing +let's uh uh say that well we're working + + align:start position:0% +let's uh uh say that well we're working + + + align:start position:0% +let's uh uh say that well we're working +with fraction objects and so + + align:start position:0% +with fraction objects and so + + + align:start position:0% +with fraction objects and so +uh the dunder methods that we're writing + + align:start position:0% +uh the dunder methods that we're writing + + + align:start position:0% +uh the dunder methods that we're writing +are now returning other fraction + + align:start position:0% +are now returning other fraction + + + align:start position:0% +are now returning other fraction +objects so let's allow the user the + + align:start position:0% +objects so let's allow the user the + + + align:start position:0% +objects so let's allow the user the +opportunity to cast one of these + + align:start position:0% +opportunity to cast one of these + + + align:start position:0% +opportunity to cast one of these +fraction objects to a float just in case + + align:start position:0% +fraction objects to a float just in case + + + align:start position:0% +fraction objects to a float just in case +they would like to grab the you know the + + align:start position:0% +they would like to grab the you know the + + + align:start position:0% +they would like to grab the you know the +the the float value of + + align:start position:0% +the the float value of + + + align:start position:0% +the the float value of +316 right that's a very reasonable thing + + align:start position:0% +316 right that's a very reasonable thing + + + align:start position:0% +316 right that's a very reasonable thing +they might want to do so let's you know + + align:start position:0% +they might want to do so let's you know + + + align:start position:0% +they might want to do so let's you know +get ahead of them and add that as part + + align:start position:0% +get ahead of them and add that as part + + + align:start position:0% +get ahead of them and add that as part +of our class definition so to uh cast + + align:start position:0% +of our class definition so to uh cast + + + align:start position:0% +of our class definition so to uh cast +things to a FL in this particular case + + align:start position:0% +things to a FL in this particular case + + + align:start position:0% +things to a FL in this particular case +the dunder method for that iscore float + + align:start position:0% +the dunder method for that iscore float + + + align:start position:0% +the dunder method for that iscore float +double + + align:start position:0% +double + + + align:start position:0% +double +underscore and all it's going to do is + + align:start position:0% +underscore and all it's going to do is + + + align:start position:0% +underscore and all it's going to do is +grab the numerator of self and divide it + + align:start position:0% +grab the numerator of self and divide it + + + align:start position:0% +grab the numerator of self and divide it +by the denominator of self right so this + + align:start position:0% +by the denominator of self right so this + + + align:start position:0% +by the denominator of self right so this +will just do a division self. num is a + + align:start position:0% +will just do a division self. num is a + + + align:start position:0% +will just do a division self. num is a +number self. denom is another number it + + align:start position:0% +number self. denom is another number it + + + align:start position:0% +number self. denom is another number it +does the division and this returns a + + align:start position:0% +does the division and this returns a + + + align:start position:0% +does the division and this returns a +float right so here when we multiply C + + align:start position:0% +float right so here when we multiply C + + + align:start position:0% +float right so here when we multiply C +is equal to a * B remember that c became + + align:start position:0% +is equal to a * B remember that c became + + + align:start position:0% +is equal to a * B remember that c became +a fraction object with numerator 3 and + + align:start position:0% +a fraction object with numerator 3 and + + + align:start position:0% +a fraction object with numerator 3 and +denom minator 16 right you remember that + + align:start position:0% +denom minator 16 right you remember that + + + align:start position:0% +denom minator 16 right you remember that +so then when we cast it to a float down + + align:start position:0% +so then when we cast it to a float down + + + align:start position:0% +so then when we cast it to a float down +here python says hey did you implement + + align:start position:0% +here python says hey did you implement + + + align:start position:0% +here python says hey did you implement +the dunder method double uncore float + + align:start position:0% +the dunder method double uncore float + + + align:start position:0% +the dunder method double uncore float +double underscore oh yeah you did let me + + align:start position:0% +double underscore oh yeah you did let me + + + align:start position:0% +double underscore oh yeah you did let me +just go ahead and do the thing that you + + align:start position:0% +just go ahead and do the thing that you + + + align:start position:0% +just go ahead and do the thing that you +want me to do inside it so it takes the + + align:start position:0% +want me to do inside it so it takes the + + + align:start position:0% +want me to do inside it so it takes the +three divides it by the 16 and it prints + + align:start position:0% + + + + align:start position:0% + + + align:start position:0% + + + + align:start position:0% + +right okay let's try it out a little bit + + align:start position:0% +right okay let's try it out a little bit + + + align:start position:0% +right okay let's try it out a little bit +more so here I've got two action objects + + align:start position:0% +more so here I've got two action objects + + + align:start position:0% +more so here I've got two action objects +um one representing 1 over 4 the other + + align:start position:0% +um one representing 1 over 4 the other + + + align:start position:0% +um one representing 1 over 4 the other +one representing 2 over 3 I multiply + + align:start position:0% +one representing 2 over 3 I multiply + + + align:start position:0% +one representing 2 over 3 I multiply +those two together again this gives me a + + align:start position:0% +those two together again this gives me a + + + align:start position:0% +those two together again this gives me a +fraction object right because it's + + align:start position:0% +fraction object right because it's + + + align:start position:0% +fraction object right because it's +running the the mold Dunder method and + + align:start position:0% +running the the mold Dunder method and + + + align:start position:0% +running the the mold Dunder method and +the mold Dunder method gives me uh a + + align:start position:0% +the mold Dunder method gives me uh a + + + align:start position:0% +the mold Dunder method gives me uh a +fraction object with a new numerator and + + align:start position:0% +fraction object with a new numerator and + + + align:start position:0% +fraction object with a new numerator and +denominator so when I print the return + + align:start position:0% +denominator so when I print the return + + + align:start position:0% +denominator so when I print the return +of that when I print C this prints the + + align:start position:0% +of that when I print C this prints the + + + align:start position:0% +of that when I print C this prints the +new numerator which is 2 * 1 divided by + + align:start position:0% +new numerator which is 2 * 1 divided by + + + align:start position:0% +new numerator which is 2 * 1 divided by +the new denominator which is 4 * 3 so it + + align:start position:0% +the new denominator which is 4 * 3 so it + + + align:start position:0% +the new denominator which is 4 * 3 so it +prints 2 over 12 + + align:start position:0% +prints 2 over 12 + + + align:start position:0% +prints 2 over 12 +does that look okay to + + align:start position:0% +does that look okay to + + + align:start position:0% +does that look okay to +you I mean it looks okay but suppose + + align:start position:0% +you I mean it looks okay but suppose + + + align:start position:0% +you I mean it looks okay but suppose +you're doing you know calculations with + + align:start position:0% +you're doing you know calculations with + + + align:start position:0% +you're doing you know calculations with +a whole bunch of numbers and at some + + align:start position:0% +a whole bunch of numbers and at some + + + align:start position:0% +a whole bunch of numbers and at some +point you get to really big numerators + + align:start position:0% +point you get to really big numerators + + + align:start position:0% +point you get to really big numerators +and really big + + align:start position:0% +and really big + + + align:start position:0% +and really big +denominators but + + align:start position:0% +denominators but + + + align:start position:0% +denominators but +then you stared it long enough and + + align:start position:0% +then you stared it long enough and + + + align:start position:0% +then you stared it long enough and +realize that that big numerator divided + + align:start position:0% +realize that that big numerator divided + + + align:start position:0% +realize that that big numerator divided +by that big denominator is actually + + align:start position:0% +by that big denominator is actually + + + align:start position:0% +by that big denominator is actually +something like one + + align:start position:0% +something like one + + + align:start position:0% +something like one +over4 right so this is not + + align:start position:0% +over4 right so this is not + + + align:start position:0% +over4 right so this is not +reduced right which is fine our code is + + align:start position:0% +reduced right which is fine our code is + + + align:start position:0% +reduced right which is fine our code is +not doing the reduction but it would be + + align:start position:0% +not doing the reduction but it would be + + + align:start position:0% +not doing the reduction but it would be +nice to write a method that allows the + + align:start position:0% +nice to write a method that allows the + + + align:start position:0% +nice to write a method that allows the +user to reduce a fraction right that + + align:start position:0% +user to reduce a fraction right that + + + align:start position:0% +user to reduce a fraction right that +would be really nice so can we fix this + + align:start position:0% +would be really nice so can we fix this + + + align:start position:0% +would be really nice so can we fix this +yes we can otherwise we wouldn't be here + + align:start position:0% +yes we can otherwise we wouldn't be here + + + align:start position:0% +yes we can otherwise we wouldn't be here +so let's write this method to reduce a + + align:start position:0% +so let's write this method to reduce a + + + align:start position:0% +so let's write this method to reduce a +fraction object it looks like a + + align:start position:0% +fraction object it looks like a + + + align:start position:0% +fraction object it looks like a +lot but it's not trust me okay it's just + + align:start position:0% +lot but it's not trust me okay it's just + + + align:start position:0% +lot but it's not trust me okay it's just +a bunch of if eles so the first part + + align:start position:0% +a bunch of if eles so the first part + + + align:start position:0% +a bunch of if eles so the first part +part of it is a little helper function + + align:start position:0% +part of it is a little helper function + + + align:start position:0% +part of it is a little helper function +not a method right notice there's no + + align:start position:0% +not a method right notice there's no + + + align:start position:0% +not a method right notice there's no +self going on in this gcd function right + + align:start position:0% +self going on in this gcd function right + + + align:start position:0% +self going on in this gcd function right +this is just a regular function that I + + align:start position:0% +this is just a regular function that I + + + align:start position:0% +this is just a regular function that I +will use to help me get the greatest + + align:start position:0% +will use to help me get the greatest + + + align:start position:0% +will use to help me get the greatest +common divisor for the two parameters n + + align:start position:0% +common divisor for the two parameters n + + + align:start position:0% +common divisor for the two parameters n +and + + align:start position:0% +and + + + align:start position:0% +and +D okay because when I have two numbers + + align:start position:0% +D okay because when I have two numbers + + + align:start position:0% +D okay because when I have two numbers +right if I want to reduce them I find + + align:start position:0% +right if I want to reduce them I find + + + align:start position:0% +right if I want to reduce them I find +the greatest common divisors and I'm + + align:start position:0% +the greatest common divisors and I'm + + + align:start position:0% +the greatest common divisors and I'm +going to divide the top and the Bottom + + align:start position:0% +going to divide the top and the Bottom + + + align:start position:0% +going to divide the top and the Bottom +by that divisor right and that will help + + align:start position:0% +by that divisor right and that will help + + + align:start position:0% +by that divisor right and that will help +me reduce it so this gcd function helps + + align:start position:0% +me reduce it so this gcd function helps + + + align:start position:0% +me reduce it so this gcd function helps +me find this greatest common + + align:start position:0% +me find this greatest common + + + align:start position:0% +me find this greatest common +divisor all right so here I'm just + + align:start position:0% +divisor all right so here I'm just + + + align:start position:0% +divisor all right so here I'm just +defining the function I'm not actually + + align:start position:0% +defining the function I'm not actually + + + align:start position:0% +defining the function I'm not actually +using it and then I've got uh two uh an + + align:start position:0% +using it and then I've got uh two uh an + + + align:start position:0% +using it and then I've got uh two uh an +if and an L if so if the denominator is + + align:start position:0% +if and an L if so if the denominator is + + + align:start position:0% +if and an L if so if the denominator is +zero something's super weird so I'm just + + align:start position:0% +zero something's super weird so I'm just + + + align:start position:0% +zero something's super weird so I'm just +going to return none right because + + align:start position:0% +going to return none right because + + + align:start position:0% +going to return none right because +having a fraction where the denominator + + align:start position:0% +having a fraction where the denominator + + + align:start position:0% +having a fraction where the denominator +zero maybe something went wrong else if + + align:start position:0% +zero maybe something went wrong else if + + + align:start position:0% +zero maybe something went wrong else if +the denominator is one we don't need to + + align:start position:0% +the denominator is one we don't need to + + + align:start position:0% +the denominator is one we don't need to +do any red reduction right right no + + align:start position:0% +do any red reduction right right no + + + align:start position:0% +do any red reduction right right no +reducing is needed so we just return the + + align:start position:0% +reducing is needed so we just return the + + + align:start position:0% +reducing is needed so we just return the +numerator and else I do have two actual + + align:start position:0% +numerator and else I do have two actual + + + align:start position:0% +numerator and else I do have two actual +numbers that I could maybe could + + align:start position:0% +numbers that I could maybe could + + + align:start position:0% +numbers that I could maybe could +potentially reduce so let's just uh + + align:start position:0% +potentially reduce so let's just uh + + + align:start position:0% +potentially reduce so let's just uh +reduce them the first line here runs + + align:start position:0% +reduce them the first line here runs + + + align:start position:0% +reduce them the first line here runs +this function this helper function that + + align:start position:0% +this function this helper function that + + + align:start position:0% +this function this helper function that +I wrote on the numerator and denominator + + align:start position:0% +I wrote on the numerator and denominator + + + align:start position:0% +I wrote on the numerator and denominator +to grab the greatest common divisor so + + align:start position:0% +to grab the greatest common divisor so + + + align:start position:0% +to grab the greatest common divisor so +you know if it's 2 over 12 it'll find + + align:start position:0% +you know if it's 2 over 12 it'll find + + + align:start position:0% +you know if it's 2 over 12 it'll find +two then the next line here take the + + align:start position:0% +two then the next line here take the + + + align:start position:0% +two then the next line here take the +numer the numerator and divides by that + + align:start position:0% +numer the numerator and divides by that + + + align:start position:0% +numer the numerator and divides by that +greatest common divisor and casts it to + + align:start position:0% +greatest common divisor and casts it to + + + align:start position:0% +greatest common divisor and casts it to +an INT right because I want my numerator + + align:start position:0% +an INT right because I want my numerator + + + align:start position:0% +an INT right because I want my numerator +to be an INT and my denominator to be an + + align:start position:0% +to be an INT and my denominator to be an + + + align:start position:0% +to be an INT and my denominator to be an +INT right so it'll take the numerator + + align:start position:0% +INT right so it'll take the numerator + + + align:start position:0% +INT right so it'll take the numerator +and divide by for example two same with + + align:start position:0% +and divide by for example two same with + + + align:start position:0% +and divide by for example two same with +denominator I'm going to take my + + align:start position:0% +denominator I'm going to take my + + + align:start position:0% +denominator I'm going to take my +denominator and divide by that same gcd + + align:start position:0% +denominator and divide by that same gcd + + + align:start position:0% +denominator and divide by that same gcd +I + + align:start position:0% +I + + + align:start position:0% +I +found casting to an in so my new top and + + align:start position:0% +found casting to an in so my new top and + + + align:start position:0% +found casting to an in so my new top and +my new bottom will now be used to create + + align:start position:0% +my new bottom will now be used to create + + + align:start position:0% +my new bottom will now be used to create +a new fraction object + + align:start position:0% +a new fraction object + + + align:start position:0% +a new fraction object +that is in reduced form so one6 for the + + align:start position:0% +that is in reduced form so one6 for the + + + align:start position:0% +that is in reduced form so one6 for the +example + + align:start position:0% +example + + + align:start position:0% +example +212 right so here it is this is my + + align:start position:0% +212 right so here it is this is my + + + align:start position:0% +212 right so here it is this is my +previous example where I multiplied that + + align:start position:0% +previous example where I multiplied that + + + align:start position:0% +previous example where I multiplied that +thing that gave + + align:start position:0% +thing that gave + + + align:start position:0% +thing that gave +me + + align:start position:0% +me + + + align:start position:0% +me +212 and then if I do c. reduce python + + align:start position:0% +212 and then if I do c. reduce python + + + align:start position:0% +212 and then if I do c. reduce python +will call the reduce method on C so the + + align:start position:0% +will call the reduce method on C so the + + + align:start position:0% +will call the reduce method on C so the +object that's uh whose numerator is two + + align:start position:0% +object that's uh whose numerator is two + + + align:start position:0% +object that's uh whose numerator is two +and denominator is 12 and then this will + + align:start position:0% +and denominator is 12 and then this will + + + align:start position:0% +and denominator is 12 and then this will +reduce it to 1 over six and we will + + align:start position:0% +reduce it to 1 over six and we will + + + align:start position:0% +reduce it to 1 over six and we will +print call the Str Str method on an OB + + align:start position:0% +print call the Str Str method on an OB + + + align:start position:0% +print call the Str Str method on an OB +of type um fraction to give me one over + + align:start position:0% +of type um fraction to give me one over + + + align:start position:0% +of type um fraction to give me one over +six everyone okay + + align:start position:0% + + + + align:start position:0% + +yes um you could put it outside the + + align:start position:0% +yes um you could put it outside the + + + align:start position:0% +yes um you could put it outside the +reduce but since it's being used + + align:start position:0% +reduce but since it's being used + + + align:start position:0% +reduce but since it's being used +specifically in the reduce we'd like to + + align:start position:0% +specifically in the reduce we'd like to + + + align:start position:0% +specifically in the reduce we'd like to +just keep it within right so it's not if + + align:start position:0% +just keep it within right so it's not if + + + align:start position:0% +just keep it within right so it's not if +it doesn't need to be used by other + + align:start position:0% +it doesn't need to be used by other + + + align:start position:0% +it doesn't need to be used by other +things we'll just keep it only to the + + align:start position:0% +things we'll just keep it only to the + + + align:start position:0% +things we'll just keep it only to the +sort of scope where it needs to exist + + align:start position:0% +sort of scope where it needs to exist + + + align:start position:0% +sort of scope where it needs to exist +but it it can be outside + + align:start position:0% + + + + align:start position:0% + +yeah okay so one thing is weird here + + align:start position:0% +yeah okay so one thing is weird here + + + align:start position:0% +yeah okay so one thing is weird here +though right this L if + + align:start position:0% + + + + align:start position:0% + +here um what is the type uh that is gets + + align:start position:0% +here um what is the type uh that is gets + + + align:start position:0% +here um what is the type uh that is gets +returned from the elves you guys tell me + + align:start position:0% +returned from the elves you guys tell me + + + align:start position:0% +returned from the elves you guys tell me +what's this type here that gets returned + + align:start position:0% +what's this type here that gets returned + + + align:start position:0% +what's this type here that gets returned +down in the else fraction what is the + + align:start position:0% +down in the else fraction what is the + + + align:start position:0% +down in the else fraction what is the +type being returned in the L if + + align:start position:0% + + + + align:start position:0% + +yes an + + align:start position:0% +yes an + + + align:start position:0% +yes an +INT so if the denominator happens to be + + align:start position:0% +INT so if the denominator happens to be + + + align:start position:0% +INT so if the denominator happens to be +a one this function uh this method + + align:start position:0% +a one this function uh this method + + + align:start position:0% +a one this function uh this method +reduce returns an + + align:start position:0% +reduce returns an + + + align:start position:0% +reduce returns an +integer if it's not it returns a + + align:start position:0% +integer if it's not it returns a + + + align:start position:0% +integer if it's not it returns a +fraction so if at some point in the + + align:start position:0% +fraction so if at some point in the + + + align:start position:0% +fraction so if at some point in the +future you're mixing you know you you + + align:start position:0% +future you're mixing you know you you + + + align:start position:0% +future you're mixing you know you you +happen to reduce something that has a + + align:start position:0% +happen to reduce something that has a + + + align:start position:0% +happen to reduce something that has a +denominator of one you're now working + + align:start position:0% +denominator of one you're now working + + + align:start position:0% +denominator of one you're now working +with integers and then potentially you'd + + align:start position:0% +with integers and then potentially you'd + + + align:start position:0% +with integers and then potentially you'd +be doing further operations by mixing + + align:start position:0% +be doing further operations by mixing + + + align:start position:0% +be doing further operations by mixing +that with fraction object so as an + + align:start position:0% +that with fraction object so as an + + + align:start position:0% +that with fraction object so as an +example here I've got a fraction object + + align:start position:0% +example here I've got a fraction object + + + align:start position:0% +example here I've got a fraction object +a 4 over one B 3 over9 reducing a gives + + align:start position:0% +a 4 over one B 3 over9 reducing a gives + + + align:start position:0% +a 4 over one B 3 over9 reducing a gives +me a four fine it's the integer four and + + align:start position:0% +me a four fine it's the integer four and + + + align:start position:0% +me a four fine it's the integer four and +reducing B gives me one over three it's + + align:start position:0% +reducing B gives me one over three it's + + + align:start position:0% +reducing B gives me one over three it's +fraction one over three right so the + + align:start position:0% +fraction one over three right so the + + + align:start position:0% +fraction one over three right so the +type just to show you exactly you know + + align:start position:0% +type just to show you exactly you know + + + align:start position:0% +type just to show you exactly you know +that I'm not lying uh the type of the A + + align:start position:0% +that I'm not lying uh the type of the A + + + align:start position:0% +that I'm not lying uh the type of the A +reduced is an INT right that's what the + + align:start position:0% +reduced is an INT right that's what the + + + align:start position:0% +reduced is an INT right that's what the +code is doing and the type of b reduced + + align:start position:0% +code is doing and the type of b reduced + + + align:start position:0% +code is doing and the type of b reduced +is a fraction + + align:start position:0% +is a fraction + + + align:start position:0% +is a fraction +so then when we do the star operator + + align:start position:0% +so then when we do the star operator + + + align:start position:0% +so then when we do the star operator +between AR and BR Python's going to say + + align:start position:0% +between AR and BR Python's going to say + + + align:start position:0% +between AR and BR Python's going to say +you're trying to multiply an in with a + + align:start position:0% +you're trying to multiply an in with a + + + align:start position:0% +you're trying to multiply an in with a +fraction did you ever tell me how to do + + align:start position:0% +fraction did you ever tell me how to do + + + align:start position:0% +fraction did you ever tell me how to do +that no right we told it how to multiply + + align:start position:0% +that no right we told it how to multiply + + + align:start position:0% +that no right we told it how to multiply +a fraction in another fraction but not + + align:start position:0% +a fraction in another fraction but not + + + align:start position:0% +a fraction in another fraction but not +an INT with a fraction and so python + + align:start position:0% +an INT with a fraction and so python + + + align:start position:0% +an INT with a fraction and so python +will fail here right so one thing that + + align:start position:0% +will fail here right so one thing that + + + align:start position:0% +will fail here right so one thing that +you can do to fix it is to change uh + + align:start position:0% +you can do to fix it is to change uh + + + align:start position:0% +you can do to fix it is to change uh +this + + align:start position:0% +this + + + align:start position:0% +this +L if here so let's have everything + + align:start position:0% +L if here so let's have everything + + + align:start position:0% +L if here so let's have everything +consistent so I want you to do this + + align:start position:0% +consistent so I want you to do this + + + align:start position:0% +consistent so I want you to do this +change instead of returning self. num + + align:start position:0% +change instead of returning self. num + + + align:start position:0% +change instead of returning self. num +return for me a fraction object + + align:start position:0% +return for me a fraction object + + + align:start position:0% +return for me a fraction object +representing the numerator + + align:start position:0% +representing the numerator + + + align:start position:0% +representing the numerator +right all right does anyone know just a + + align:start position:0% +right all right does anyone know just a + + + align:start position:0% +right all right does anyone know just a +small change to instead of returning + + align:start position:0% +small change to instead of returning + + + align:start position:0% +small change to instead of returning +self. num what should I + + align:start position:0% +self. num what should I + + + align:start position:0% +self. num what should I +return how do I make a fraction object + + align:start position:0% +return how do I make a fraction object + + + align:start position:0% +return how do I make a fraction object +just invoke the name of fraction right + + align:start position:0% +just invoke the name of fraction right + + + align:start position:0% +just invoke the name of fraction right +what's the numerator of this fraction + + align:start position:0% +what's the numerator of this fraction + + + align:start position:0% +what's the numerator of this fraction +object supposed to be + + align:start position:0% +object supposed to be + + + align:start position:0% +object supposed to be +it's already there self. num what's the + + align:start position:0% +it's already there self. num what's the + + + align:start position:0% +it's already there self. num what's the +denominator of this fraction + + align:start position:0% +denominator of this fraction + + + align:start position:0% +denominator of this fraction +object yeah exactly so it just returns a + + align:start position:0% +object yeah exactly so it just returns a + + + align:start position:0% +object yeah exactly so it just returns a +fraction object whose numerator is + + align:start position:0% +fraction object whose numerator is + + + align:start position:0% +fraction object whose numerator is +selfon num and denominator is one + + align:start position:0% +selfon num and denominator is one + + + align:start position:0% +selfon num and denominator is one +exactly right so now all the different + + align:start position:0% +exactly right so now all the different + + + align:start position:0% +exactly right so now all the different +cases except for this randomly weird + + align:start position:0% +cases except for this randomly weird + + + align:start position:0% +cases except for this randomly weird +denominator being zero right in case + + align:start position:0% +denominator being zero right in case + + + align:start position:0% +denominator being zero right in case +that happens some something's gone wrong + + align:start position:0% +that happens some something's gone wrong + + + align:start position:0% +that happens some something's gone wrong +maybe all the other cases are returning + + align:start position:0% +maybe all the other cases are returning + + + align:start position:0% +maybe all the other cases are returning +a fraction object which is good because + + align:start position:0% +a fraction object which is good because + + + align:start position:0% +a fraction object which is good because +now it's consistent + + align:start position:0% + + + + align:start position:0% + +right oh yeah exactly so we did say we + + align:start position:0% +right oh yeah exactly so we did say we + + + align:start position:0% +right oh yeah exactly so we did say we +didn't want it to be five over one but + + align:start position:0% +didn't want it to be five over one but + + + align:start position:0% +didn't want it to be five over one but +this is actually using the old Str Str + + align:start position:0% +this is actually using the old Str Str + + + align:start position:0% +this is actually using the old Str Str +method where we didn't do that check so + + align:start position:0% +method where we didn't do that check so + + + align:start position:0% +method where we didn't do that check so +it will print five over one but if we + + align:start position:0% +it will print five over one but if we + + + align:start position:0% +it will print five over one but if we +you know if we do the check if self. D + + align:start position:0% +you know if we do the check if self. D + + + align:start position:0% +you know if we do the check if self. D +Nom equal one then return stir self. n + + align:start position:0% +Nom equal one then return stir self. n + + + align:start position:0% +Nom equal one then return stir self. n +like if we add that then it won't do + + align:start position:0% +like if we add that then it won't do + + + align:start position:0% +like if we add that then it won't do +that yeah but this is just using the old + + align:start position:0% +that yeah but this is just using the old + + + align:start position:0% +that yeah but this is just using the old +uh strr method that doesn't do that nice + + align:start position:0% +uh strr method that doesn't do that nice + + + align:start position:0% +uh strr method that doesn't do that nice +formatting for + + align:start position:0% +formatting for + + + align:start position:0% +formatting for +us + + align:start position:0% + + + + align:start position:0% + +questions right we've been working a lot + + align:start position:0% +questions right we've been working a lot + + + align:start position:0% +questions right we've been working a lot +with returning new objects of the same + + align:start position:0% +with returning new objects of the same + + + align:start position:0% +with returning new objects of the same +type that we're writing right that's + + align:start position:0% +type that we're writing right that's + + + align:start position:0% +type that we're writing right that's +sort of a new thing + + align:start position:0% +sort of a new thing + + + align:start position:0% +sort of a new thing +today okay + + align:start position:0% +today okay + + + align:start position:0% +today okay +um + + align:start position:0% +um + + + align:start position:0% +um +so what's the purpose of these two + + align:start position:0% +so what's the purpose of these two + + + align:start position:0% +so what's the purpose of these two +lectures right so hopefully it shows + + align:start position:0% +lectures right so hopefully it shows + + + align:start position:0% +lectures right so hopefully it shows +that + + align:start position:0% +that + + + align:start position:0% +that +um it's very useful to uh to bundle data + + align:start position:0% +um it's very useful to uh to bundle data + + + align:start position:0% +um it's very useful to uh to bundle data +and behaviors together right so the + + align:start position:0% +and behaviors together right so the + + + align:start position:0% +and behaviors together right so the +ultimate goal when we're writing + + align:start position:0% +ultimate goal when we're writing + + + align:start position:0% +ultimate goal when we're writing +programs is to write code that's modular + + align:start position:0% +programs is to write code that's modular + + + align:start position:0% +programs is to write code that's modular +organized right because in the future + + align:start position:0% +organized right because in the future + + + align:start position:0% +organized right because in the future +you might want to build upon this code + + align:start position:0% +you might want to build upon this code + + + align:start position:0% +you might want to build upon this code +in the future you might want to read + + align:start position:0% +in the future you might want to read + + + align:start position:0% +in the future you might want to read +this code to use it for something else + + align:start position:0% +this code to use it for something else + + + align:start position:0% +this code to use it for something else +in the future other people might want to + + align:start position:0% +in the future other people might want to + + + align:start position:0% +in the future other people might want to +read this code or use this code this + + align:start position:0% +read this code or use this code this + + + align:start position:0% +read this code or use this code this +class that you wrote to build more + + align:start position:0% +class that you wrote to build more + + + align:start position:0% +class that you wrote to build more +complex classes right like we use the + + align:start position:0% +complex classes right like we use the + + + align:start position:0% +complex classes right like we use the +coordinate class to build a circle class + + align:start position:0% +coordinate class to build a circle class + + + align:start position:0% +coordinate class to build a circle class +right other people might use your circle + + align:start position:0% +right other people might use your circle + + + align:start position:0% +right other people might use your circle +class to build I don't know a sphere + + align:start position:0% +class to build I don't know a sphere + + + align:start position:0% +class to build I don't know a sphere +class or something like that something + + align:start position:0% +class or something like that something + + + align:start position:0% +class or something like that something +more complicated and so it's really nice + + align:start position:0% +more complicated and so it's really nice + + + align:start position:0% +more complicated and so it's really nice +to create these little data types that + + align:start position:0% +to create these little data types that + + + align:start position:0% +to create these little data types that +are't organized right modular and so + + align:start position:0% +are't organized right modular and so + + + align:start position:0% +are't organized right modular and so +we're basically bundling together these + + align:start position:0% +we're basically bundling together these + + + align:start position:0% +we're basically bundling together these +data right so what makes up your object + + align:start position:0% +data right so what makes up your object + + + align:start position:0% +data right so what makes up your object +and behaviors together so we can use + + align:start position:0% +and behaviors together so we can use + + + align:start position:0% +and behaviors together so we can use +these objects in a nicely consistent way + + align:start position:0% +these objects in a nicely consistent way + + + align:start position:0% +these objects in a nicely consistent way +so remember back when we were learning + + align:start position:0% +so remember back when we were learning + + + align:start position:0% +so remember back when we were learning +about functions right the ideas of + + align:start position:0% +about functions right the ideas of + + + align:start position:0% +about functions right the ideas of +decomposition and abstraction were very + + align:start position:0% +decomposition and abstraction were very + + + align:start position:0% +decomposition and abstraction were very +important functions basically took a + + align:start position:0% +important functions basically took a + + + align:start position:0% +important functions basically took a +chunk of code and decompose them into + + align:start position:0% +chunk of code and decompose them into + + + align:start position:0% +chunk of code and decompose them into +one module that we could reuse many many + + align:start position:0% +one module that we could reuse many many + + + align:start position:0% +one module that we could reuse many many +different places right and we abstracted + + align:start position:0% +different places right and we abstracted + + + align:start position:0% +different places right and we abstracted +away the details of the function through + + align:start position:0% +away the details of the function through + + + align:start position:0% +away the details of the function through +doc string so people didn't have to slog + + align:start position:0% +doc string so people didn't have to slog + + + align:start position:0% +doc string so people didn't have to slog +through a whole bunch of code to figure + + align:start position:0% +through a whole bunch of code to figure + + + align:start position:0% +through a whole bunch of code to figure +out what the function did all they did + + align:start position:0% +out what the function did all they did + + + align:start position:0% +out what the function did all they did +was read the doc string and they knew + + align:start position:0% +was read the doc string and they knew + + + align:start position:0% +was read the doc string and they knew +exactly what we + + align:start position:0% +exactly what we + + + align:start position:0% +exactly what we +wanted now object oriented programming + + align:start position:0% +wanted now object oriented programming + + + align:start position:0% +wanted now object oriented programming +and python classes have that same big + + align:start position:0% +and python classes have that same big + + + align:start position:0% +and python classes have that same big +composition and abstraction energy right + + align:start position:0% +composition and abstraction energy right + + + align:start position:0% +composition and abstraction energy right +they've got a bunch of modules that + + align:start position:0% +they've got a bunch of modules that + + + align:start position:0% +they've got a bunch of modules that +we're creating here where we're bundling + + align:start position:0% +we're creating here where we're bundling + + + align:start position:0% +we're creating here where we're bundling +together data and behaviors right so we + + align:start position:0% +together data and behaviors right so we + + + align:start position:0% +together data and behaviors right so we +can create a whole bunch of objects that + + align:start position:0% +can create a whole bunch of objects that + + + align:start position:0% +can create a whole bunch of objects that +behave in the exact same way nicely + + align:start position:0% +behave in the exact same way nicely + + + align:start position:0% +behave in the exact same way nicely +consistent so that we know that if I + + align:start position:0% +consistent so that we know that if I + + + align:start position:0% +consistent so that we know that if I +create a coordinate object here it's + + align:start position:0% +create a coordinate object here it's + + + align:start position:0% +create a coordinate object here it's +going to have an X and A yvalue and if I + + align:start position:0% +going to have an X and A yvalue and if I + + + align:start position:0% +going to have an X and A yvalue and if I +create another coordinate object it's + + align:start position:0% +create another coordinate object it's + + + align:start position:0% +create another coordinate object it's +also going to have an X and A yvalue + + align:start position:0% +also going to have an X and A yvalue + + + align:start position:0% +also going to have an X and A yvalue +it's not suddenly going to have an X Y + + align:start position:0% +it's not suddenly going to have an X Y + + + align:start position:0% +it's not suddenly going to have an X Y +and Z value right so creating these + + align:start position:0% +and Z value right so creating these + + + align:start position:0% +and Z value right so creating these +objects that work in a consistent way is + + align:start position:0% +objects that work in a consistent way is + + + align:start position:0% +objects that work in a consistent way is +is very very is a very um you know + + align:start position:0% +is very very is a very um you know + + + align:start position:0% +is very very is a very um you know +decomposition uh and abstraction uh uh + + align:start position:0% +decomposition uh and abstraction uh uh + + + align:start position:0% +decomposition uh and abstraction uh uh +you are working with the ideas of + + align:start position:0% +you are working with the ideas of + + + align:start position:0% +you are working with the ideas of +decomposition abstraction just like + + align:start position:0% +decomposition abstraction just like + + + align:start position:0% +decomposition abstraction just like +functions did okay so next lecture we + + align:start position:0% +functions did okay so next lecture we + + + align:start position:0% +functions did okay so next lecture we +will be starting on we'll do a little + + align:start position:0% +will be starting on we'll do a little + + + align:start position:0% +will be starting on we'll do a little +bit more of these classes and then we'll + + align:start position:0% +bit more of these classes and then we'll + + + align:start position:0% +bit more of these classes and then we'll +start on inheritance so having parents + + align:start position:0% +start on inheritance so having parents + + + align:start position:0% +start on inheritance so having parents +the objects that we created all + + align:start position:0% + + + + align:start position:0% + +right \ No newline at end of file diff --git a/gWLC3r6EHl0.txt b/gWLC3r6EHl0.txt new file mode 100644 index 0000000000000000000000000000000000000000..c27054db1e0d7c380cc5f93dd29556ac82e43e04 --- /dev/null +++ b/gWLC3r6EHl0.txt @@ -0,0 +1,1067 @@ +align:start position:0% + +so when we analyzed Newton's Second Law + + align:start position:0% +so when we analyzed Newton's Second Law + + + align:start position:0% +so when we analyzed Newton's Second Law +applied to this compound system we had + + align:start position:0% +applied to this compound system we had + + + align:start position:0% +applied to this compound system we had +two equations for M1 um object one and + + align:start position:0% +two equations for M1 um object one and + + + align:start position:0% +two equations for M1 um object one and +object two and what we found is that we + + align:start position:0% +object two and what we found is that we + + + align:start position:0% +object two and what we found is that we +had three unknowns the tension in the + + align:start position:0% +had three unknowns the tension in the + + + align:start position:0% +had three unknowns the tension in the +string and the accelerations of the two + + align:start position:0% +string and the accelerations of the two + + + align:start position:0% +string and the accelerations of the two +objects now how do we F how do we solve + + align:start position:0% +objects now how do we F how do we solve + + + align:start position:0% +objects now how do we F how do we solve +this system well we're missing one + + align:start position:0% +this system well we're missing one + + + align:start position:0% +this system well we're missing one +condition which is a constraint + + align:start position:0% +condition which is a constraint + + + align:start position:0% +condition which is a constraint +condition which is as object two moves + + align:start position:0% +condition which is as object two moves + + + align:start position:0% +condition which is as object two moves +and object one moves they have to move + + align:start position:0% +and object one moves they have to move + + + align:start position:0% +and object one moves they have to move +in some relation ship together and now + + align:start position:0% +in some relation ship together and now + + + align:start position:0% +in some relation ship together and now +what we'd like to do is show an analytic + + align:start position:0% +what we'd like to do is show an analytic + + + align:start position:0% +what we'd like to do is show an analytic +approach for finding that constraint + + align:start position:0% +approach for finding that constraint + + + align:start position:0% +approach for finding that constraint +condition and what the way we think + + align:start position:0% +condition and what the way we think + + + align:start position:0% +condition and what the way we think +about it is that we'll call L equal to + + align:start position:0% +about it is that we'll call L equal to + + + align:start position:0% +about it is that we'll call L equal to +the length of the + + align:start position:0% +the length of the + + + align:start position:0% +the length of the +string and this quantity is a + + align:start position:0% +string and this quantity is a + + + align:start position:0% +string and this quantity is a +constant and what we'd like to do is + + align:start position:0% +constant and what we'd like to do is + + + align:start position:0% +constant and what we'd like to do is +introduce coordinate functions for our + + align:start position:0% +introduce coordinate functions for our + + + align:start position:0% +introduce coordinate functions for our +object one and our object two and + + align:start position:0% +object one and our object two and + + + align:start position:0% +object one and our object two and +express l in terms of those coordinate + + align:start position:0% +express l in terms of those coordinate + + + align:start position:0% +express l in terms of those coordinate +functions and then take two derivatives + + align:start position:0% +functions and then take two derivatives + + + align:start position:0% +functions and then take two derivatives +of L set that equal to zero because it's + + align:start position:0% +of L set that equal to zero because it's + + + align:start position:0% +of L set that equal to zero because it's +a constant and that will give us a + + align:start position:0% +a constant and that will give us a + + + align:start position:0% +a constant and that will give us a +relationship between the accelerations + + align:start position:0% +relationship between the accelerations + + + align:start position:0% +relationship between the accelerations +of objects one and two now this is a + + align:start position:0% +of objects one and two now this is a + + + align:start position:0% +of objects one and two now this is a +little bit tricky and so what we want to + + align:start position:0% +little bit tricky and so what we want to + + + align:start position:0% +little bit tricky and so what we want to +do is very carefully show how we + + align:start position:0% +do is very carefully show how we + + + align:start position:0% +do is very carefully show how we +introduce coordinate functions recall + + align:start position:0% +introduce coordinate functions recall + + + align:start position:0% +introduce coordinate functions recall +that we had J hat one down and J hat two + + align:start position:0% +that we had J hat one down and J hat two + + + align:start position:0% +that we had J hat one down and J hat two +downwards what that implies is that + + align:start position:0% +downwards what that implies is that + + + align:start position:0% +downwards what that implies is that +we're choosing some origin and we're + + align:start position:0% +we're choosing some origin and we're + + + align:start position:0% +we're choosing some origin and we're +let's choose an origin up here and for a + + align:start position:0% +let's choose an origin up here and for a + + + align:start position:0% +let's choose an origin up here and for a +coordinate function for object one it + + align:start position:0% +coordinate function for object one it + + + align:start position:0% +coordinate function for object one it +has to be consistent with our choice of + + align:start position:0% +has to be consistent with our choice of + + + align:start position:0% +has to be consistent with our choice of +what we mean by jat1 so in this sense y1 + + align:start position:0% +what we mean by jat1 so in this sense y1 + + + align:start position:0% +what we mean by jat1 so in this sense y1 +is a positive quantity when we're going + + align:start position:0% +is a positive quantity when we're going + + + align:start position:0% +is a positive quantity when we're going +downward um now what about coordinate + + align:start position:0% +downward um now what about coordinate + + + align:start position:0% +downward um now what about coordinate +functions for the other objects in the + + align:start position:0% +functions for the other objects in the + + + align:start position:0% +functions for the other objects in the +system well let's look at a few things + + align:start position:0% +system well let's look at a few things + + + align:start position:0% +system well let's look at a few things +first um this is a fixed distance we'll + + align:start position:0% +first um this is a fixed distance we'll + + + align:start position:0% +first um this is a fixed distance we'll +call it S1 between the center of the + + align:start position:0% +call it S1 between the center of the + + + align:start position:0% +call it S1 between the center of the +pulley + + align:start position:0% +pulley + + + align:start position:0% +pulley +and between the ceiling and the center + + align:start position:0% +and between the ceiling and the center + + + align:start position:0% +and between the ceiling and the center +of the pulley and let's make each of the + + align:start position:0% +of the pulley and let's make each of the + + + align:start position:0% +of the pulley and let's make each of the +pulleys a radius + + align:start position:0% +pulleys a radius + + + align:start position:0% +pulleys a radius +R and let's call this a + + align:start position:0% +R and let's call this a + + + align:start position:0% +R and let's call this a +function y + + align:start position:0% +function y + + + align:start position:0% +function y +b and let's make this Y 2 of T so now we + + align:start position:0% +b and let's make this Y 2 of T so now we + + + align:start position:0% +b and let's make this Y 2 of T so now we +have coordinate functions for two and + + align:start position:0% +have coordinate functions for two and + + + align:start position:0% +have coordinate functions for two and +coordinate functions for one and again + + align:start position:0% +coordinate functions for one and again + + + align:start position:0% +coordinate functions for one and again +recall that this distance here S2 is a + + align:start position:0% +recall that this distance here S2 is a + + + align:start position:0% +recall that this distance here S2 is a +fixed + + align:start position:0% +fixed + + + align:start position:0% +fixed +distance and when Define these + + align:start position:0% +distance and when Define these + + + align:start position:0% +distance and when Define these +coordinate functions in this fashion we + + align:start position:0% +coordinate functions in this fashion we + + + align:start position:0% +coordinate functions in this fashion we +know that the second derivative d^2 + + align:start position:0% +know that the second derivative d^2 + + + align:start position:0% +know that the second derivative d^2 +y1 DT ^2 this is precisely what we mean + + align:start position:0% +y1 DT ^2 this is precisely what we mean + + + align:start position:0% +y1 DT ^2 this is precisely what we mean +by the acceleration of object one and in + + align:start position:0% +by the acceleration of object one and in + + + align:start position:0% +by the acceleration of object one and in +the similar fashion d^2 Y 2 DT ^2 is + + align:start position:0% +the similar fashion d^2 Y 2 DT ^2 is + + + align:start position:0% +the similar fashion d^2 Y 2 DT ^2 is +what we mean by the acceleration of + + align:start position:0% +what we mean by the acceleration of + + + align:start position:0% +what we mean by the acceleration of +object 2 so we've introduced a + + align:start position:0% +object 2 so we've introduced a + + + align:start position:0% +object 2 so we've introduced a +coordinate system we've made it very + + align:start position:0% +coordinate system we've made it very + + + align:start position:0% +coordinate system we've made it very +clear what we mean by the accelerations + + align:start position:0% +clear what we mean by the accelerations + + + align:start position:0% +clear what we mean by the accelerations +of A1 and A2 and now let's look at our + + align:start position:0% +of A1 and A2 and now let's look at our + + + align:start position:0% +of A1 and A2 and now let's look at our +constraint condition that the length of + + align:start position:0% +constraint condition that the length of + + + align:start position:0% +constraint condition that the length of +the string is constant so what we're + + align:start position:0% +the string is constant so what we're + + + align:start position:0% +the string is constant so what we're +going to do is try to see if we can + + align:start position:0% +going to do is try to see if we can + + + align:start position:0% +going to do is try to see if we can +express the length of this string in + + align:start position:0% +express the length of this string in + + + align:start position:0% +express the length of this string in +terms of all the coordinate functions + + align:start position:0% +terms of all the coordinate functions + + + align:start position:0% +terms of all the coordinate functions +and some of these ancillary quantities + + align:start position:0% +and some of these ancillary quantities + + + align:start position:0% +and some of these ancillary quantities +so what we have here is that the length + + align:start position:0% +so what we have here is that the length + + + align:start position:0% +so what we have here is that the length +of the string is + + align:start position:0% +of the string is + + + align:start position:0% +of the string is +YB going down here so the length of the + + align:start position:0% +YB going down here so the length of the + + + align:start position:0% +YB going down here so the length of the +string has a factor YB it wraps around + + align:start position:0% +string has a factor YB it wraps around + + + align:start position:0% +string has a factor YB it wraps around +pulley B so that's pi + + align:start position:0% +pulley B so that's pi + + + align:start position:0% +pulley B so that's pi +r and it goes up to this length + + align:start position:0% +r and it goes up to this length + + + align:start position:0% +r and it goes up to this length +here now this length is YB minus + + align:start position:0% +here now this length is YB minus + + + align:start position:0% +here now this length is YB minus +S1 so that's YB minus + + align:start position:0% +S1 so that's YB minus + + + align:start position:0% +S1 so that's YB minus +S1 we wrap around the pulley + + align:start position:0% +S1 we wrap around the pulley + + + align:start position:0% +S1 we wrap around the pulley +again that's pi r and now we have this + + align:start position:0% +again that's pi r and now we have this + + + align:start position:0% +again that's pi r and now we have this +length here which is y1 + + align:start position:0% +length here which is y1 + + + align:start position:0% +length here which is y1 +minus S1 now + + align:start position:0% +minus S1 now + + + align:start position:0% +minus S1 now +S1 yeah and let's just make sure we have + + align:start position:0% +S1 yeah and let's just make sure we have + + + align:start position:0% +S1 yeah and let's just make sure we have +all of our quantities here now we also + + align:start position:0% +all of our quantities here now we also + + + align:start position:0% +all of our quantities here now we also +have another constraint condition that + + align:start position:0% +have another constraint condition that + + + align:start position:0% +have another constraint condition that +this length of the string call this + + align:start position:0% +this length of the string call this + + + align:start position:0% +this length of the string call this +we're going to call this + + align:start position:0% +we're going to call this + + + align:start position:0% +we're going to call this +L1 we have a second string here + + align:start position:0% +L1 we have a second string here + + + align:start position:0% +L1 we have a second string here +L2 and L2 is given by + + align:start position:0% +L2 and L2 is given by + + + align:start position:0% +L2 and L2 is given by +Y2 this length is Y2 + + align:start position:0% +Y2 this length is Y2 + + + align:start position:0% +Y2 this length is Y2 +minus YB and that was what we called + + align:start position:0% +minus YB and that was what we called + + + align:start position:0% +minus YB and that was what we called +this constant + + align:start position:0% +this constant + + + align:start position:0% +this constant +S2 so we now have two string lengths L2 + + align:start position:0% +S2 so we now have two string lengths L2 + + + align:start position:0% +S2 so we now have two string lengths L2 += Y2 minus YB and both of these string + + align:start position:0% += Y2 minus YB and both of these string + + + align:start position:0% += Y2 minus YB and both of these string +lengths are constant and we have the + + align:start position:0% +lengths are constant and we have the + + + align:start position:0% +lengths are constant and we have the +following facts let's start with this + + align:start position:0% +following facts let's start with this + + + align:start position:0% +following facts let's start with this +one first that the second derivative of + + align:start position:0% +one first that the second derivative of + + + align:start position:0% +one first that the second derivative of +L2 DT ^2 because the length of the + + align:start position:0% +L2 DT ^2 because the length of the + + + align:start position:0% +L2 DT ^2 because the length of the +string is a constant that's zero and + + align:start position:0% +string is a constant that's zero and + + + align:start position:0% +string is a constant that's zero and +that tells us two derivatives of this is + + align:start position:0% +that tells us two derivatives of this is + + + align:start position:0% +that tells us two derivatives of this is +A2 and two derivatives of that is AB and + + align:start position:0% +A2 and two derivatives of that is AB and + + + align:start position:0% +A2 and two derivatives of that is AB and +this is something that we saw before + + align:start position:0% +this is something that we saw before + + + align:start position:0% +this is something that we saw before +that Block B and two are moving together + + align:start position:0% +that Block B and two are moving together + + + align:start position:0% +that Block B and two are moving together +so when we treated the system as just B + + align:start position:0% +so when we treated the system as just B + + + align:start position:0% +so when we treated the system as just B +and two together we see that the + + align:start position:0% +and two together we see that the + + + align:start position:0% +and two together we see that the +acceleration of two and the acceleration + + align:start position:0% +acceleration of two and the acceleration + + + align:start position:0% +acceleration of two and the acceleration +of pulley B are the same so we could + + align:start position:0% +of pulley B are the same so we could + + + align:start position:0% +of pulley B are the same so we could +have just said that before we began now + + align:start position:0% +have just said that before we began now + + + align:start position:0% +have just said that before we began now +let's put these equations aside for the + + align:start position:0% +let's put these equations aside for the + + + align:start position:0% +let's put these equations aside for the +moment and now let's consider taking two + + align:start position:0% +moment and now let's consider taking two + + + align:start position:0% +moment and now let's consider taking two +derivatives of + + align:start position:0% +derivatives of + + + align:start position:0% +derivatives of +length of string one we call string one + + align:start position:0% +length of string one we call string one + + + align:start position:0% +length of string one we call string one +is this object here we'll call this + + align:start position:0% +is this object here we'll call this + + + align:start position:0% +is this object here we'll call this +string + + align:start position:0% +string + + + align:start position:0% +string +one and this string two now again then + + align:start position:0% +one and this string two now again then + + + align:start position:0% +one and this string two now again then +if we take two derivatives let's look at + + align:start position:0% +if we take two derivatives let's look at + + + align:start position:0% +if we take two derivatives let's look at +our expression first um we see that we + + align:start position:0% +our expression first um we see that we + + + align:start position:0% +our expression first um we see that we +have two factors of YB and we have a + + align:start position:0% +have two factors of YB and we have a + + + align:start position:0% +have two factors of YB and we have a +bunch of constants whose derivative is + + align:start position:0% +bunch of constants whose derivative is + + + align:start position:0% +bunch of constants whose derivative is +zero so we don't have to worry about the + + align:start position:0% +zero so we don't have to worry about the + + + align:start position:0% +zero so we don't have to worry about the +wraparound distances the pi RS we don't + + align:start position:0% +wraparound distances the pi RS we don't + + + align:start position:0% +wraparound distances the pi RS we don't +have to worry about the constants S1 all + + align:start position:0% +have to worry about the constants S1 all + + + align:start position:0% +have to worry about the constants S1 all +we have to think about is which + + align:start position:0% +we have to think about is which + + + align:start position:0% +we have to think about is which +quantities are changing in time so we + + align:start position:0% +quantities are changing in time so we + + + align:start position:0% +quantities are changing in time so we +have 2 a when we take two derivatives + + align:start position:0% +have 2 a when we take two derivatives + + + align:start position:0% +have 2 a when we take two derivatives +and we have one factor of A1 and that's + + align:start position:0% +and we have one factor of A1 and that's + + + align:start position:0% +and we have one factor of A1 and that's +zero and now because the block and two + + align:start position:0% +zero and now because the block and two + + + align:start position:0% +zero and now because the block and two +and pulley B are accelerating together + + align:start position:0% +and pulley B are accelerating together + + + align:start position:0% +and pulley B are accelerating together +we have our condition which is 2 A2 + A1 + + align:start position:0% +we have our condition which is 2 A2 + A1 + + + align:start position:0% +we have our condition which is 2 A2 + A1 +is z or that A1 is equal to minus 2 + + align:start position:0% +is z or that A1 is equal to minus 2 + + + align:start position:0% +is z or that A1 is equal to minus 2 +A2 and that is the extra constraint + + align:start position:0% +A2 and that is the extra constraint + + + align:start position:0% +A2 and that is the extra constraint +condition that will enabled us to solve + + align:start position:0% +condition that will enabled us to solve + + + align:start position:0% +condition that will enabled us to solve +the system of equations \ No newline at end of file diff --git a/gWdAc-rPHW8.txt b/gWdAc-rPHW8.txt new file mode 100644 index 0000000000000000000000000000000000000000..84ebbb559def56e7748d3d281df98f9a33476296 --- /dev/null +++ b/gWdAc-rPHW8.txt @@ -0,0 +1,17600 @@ +align:start position:0% + +foreign + + align:start position:0% + + + + align:start position:0% + +if there are no immediate questions + + align:start position:0% +if there are no immediate questions + + + align:start position:0% +if there are no immediate questions +um that's good and uh if so then I'll go + + align:start position:0% +um that's good and uh if so then I'll go + + + align:start position:0% +um that's good and uh if so then I'll go +ahead and share screen and I will launch + + align:start position:0% +ahead and share screen and I will launch + + + align:start position:0% +ahead and share screen and I will launch +into our continuing adventure with + + align:start position:0% +into our continuing adventure with + + + align:start position:0% +into our continuing adventure with +quantum theory which is frankly one of + + align:start position:0% +quantum theory which is frankly one of + + + align:start position:0% +quantum theory which is frankly one of +my favorite Adventures ever + + align:start position:0% +my favorite Adventures ever + + + align:start position:0% +my favorite Adventures ever +uh speaking just for myself okay + + align:start position:0% +uh speaking just for myself okay + + + align:start position:0% +uh speaking just for myself okay +so you will hopefully remember uh on our + + align:start position:0% +so you will hopefully remember uh on our + + + align:start position:0% +so you will hopefully remember uh on our +previous class session we looked at + + align:start position:0% +previous class session we looked at + + + align:start position:0% +previous class session we looked at +um Vera Heisenberg's introduction of + + align:start position:0% +um Vera Heisenberg's introduction of + + + align:start position:0% +um Vera Heisenberg's introduction of +what came to be called Matrix mechanics + + align:start position:0% +what came to be called Matrix mechanics + + + align:start position:0% +what came to be called Matrix mechanics +uh in um sort of spring summer 1925 and + + align:start position:0% +uh in um sort of spring summer 1925 and + + + align:start position:0% +uh in um sort of spring summer 1925 and +what brought him to it what was he + + align:start position:0% +what brought him to it what was he + + + align:start position:0% +what brought him to it what was he +reacting against and a little taste of + + align:start position:0% +reacting against and a little taste of + + + align:start position:0% +reacting against and a little taste of +what people thought it might all add up + + align:start position:0% +what people thought it might all add up + + + align:start position:0% +what people thought it might all add up +to and today we're going to look + + align:start position:0% +to and today we're going to look + + + align:start position:0% +to and today we're going to look +actually at a kind of um complementary + + align:start position:0% +actually at a kind of um complementary + + + align:start position:0% +actually at a kind of um complementary +set of developments that were unfolding + + align:start position:0% +set of developments that were unfolding + + + align:start position:0% +set of developments that were unfolding +very close in time very rapid series of + + align:start position:0% +very close in time very rapid series of + + + align:start position:0% +very close in time very rapid series of +period of development but now looking at + + align:start position:0% +period of development but now looking at + + + align:start position:0% +period of development but now looking at +what became known as wave mechanics and + + align:start position:0% +what became known as wave mechanics and + + + align:start position:0% +what became known as wave mechanics and +some of its uh features that people + + align:start position:0% +some of its uh features that people + + + align:start position:0% +some of its uh features that people +began to really puzzle about + + align:start position:0% +began to really puzzle about + + + align:start position:0% +began to really puzzle about +so for today we'll we'll look at some of + + align:start position:0% +so for today we'll we'll look at some of + + + align:start position:0% +so for today we'll we'll look at some of +Erwin Schrodinger's most famous work + + align:start position:0% +Erwin Schrodinger's most famous work + + + align:start position:0% +Erwin Schrodinger's most famous work +again some of this might already be + + align:start position:0% +again some of this might already be + + + align:start position:0% +again some of this might already be +familiar to some of you but probably not + + align:start position:0% +familiar to some of you but probably not + + + align:start position:0% +familiar to some of you but probably not +to all and I think it's fun to just sort + + align:start position:0% +to all and I think it's fun to just sort + + + align:start position:0% +to all and I think it's fun to just sort +of + + align:start position:0% +of + + + align:start position:0% +of +go back through and and zoom out of it + + align:start position:0% +go back through and and zoom out of it + + + align:start position:0% +go back through and and zoom out of it +and say what what did Schrodinger think + + align:start position:0% +and say what what did Schrodinger think + + + align:start position:0% +and say what what did Schrodinger think +he was doing and why uh let alone what's + + align:start position:0% +he was doing and why uh let alone what's + + + align:start position:0% +he was doing and why uh let alone what's +the form of the equation + + align:start position:0% +the form of the equation + + + align:start position:0% +the form of the equation +um that he uh that he put together so + + align:start position:0% +um that he uh that he put together so + + + align:start position:0% +um that he uh that he put together so +that's the part one + + align:start position:0% +that's the part one + + + align:start position:0% +that's the part one +then we're going to look in Parts two + + align:start position:0% +then we're going to look in Parts two + + + align:start position:0% +then we're going to look in Parts two +and very briefly of a shorter part three + + align:start position:0% +and very briefly of a shorter part three + + + align:start position:0% +and very briefly of a shorter part three +at some of the implications that + + align:start position:0% +at some of the implications that + + + align:start position:0% +at some of the implications that +physicists began all ready to Grapple + + align:start position:0% +physicists began all ready to Grapple + + + align:start position:0% +physicists began all ready to Grapple +with implications of Schrodinger's wave + + align:start position:0% +with implications of Schrodinger's wave + + + align:start position:0% +with implications of Schrodinger's wave +mechanics really pretty quickly and for + + align:start position:0% +mechanics really pretty quickly and for + + + align:start position:0% +mechanics really pretty quickly and for +for both part two and part three + + align:start position:0% +for both part two and part three + + + align:start position:0% +for both part two and part three +um you know again as often happens for + + align:start position:0% +um you know again as often happens for + + + align:start position:0% +um you know again as often happens for +class session I'll try to cover some of + + align:start position:0% +class session I'll try to cover some of + + + align:start position:0% +class session I'll try to cover some of +the main highlights some of the most + + align:start position:0% +the main highlights some of the most + + + align:start position:0% +the main highlights some of the most +what I think most interesting or Salient + + align:start position:0% +what I think most interesting or Salient + + + align:start position:0% +what I think most interesting or Salient +points and then some of the details some + + align:start position:0% +points and then some of the details some + + + align:start position:0% +points and then some of the details some +of the extra derivations and so on are + + align:start position:0% +of the extra derivations and so on are + + + align:start position:0% +of the extra derivations and so on are +in those optional lecture notes strictly + + align:start position:0% +in those optional lecture notes strictly + + + align:start position:0% +in those optional lecture notes strictly +optional they are available on canvas + + align:start position:0% +optional they are available on canvas + + + align:start position:0% +optional they are available on canvas +but if something goes by too quickly or + + align:start position:0% +but if something goes by too quickly or + + + align:start position:0% +but if something goes by too quickly or +I just had to sort of skim over some of + + align:start position:0% +I just had to sort of skim over some of + + + align:start position:0% +I just had to sort of skim over some of +the intervening steps that sometimes + + align:start position:0% +the intervening steps that sometimes + + + align:start position:0% +the intervening steps that sometimes +happens and hopefully those lecture + + align:start position:0% +happens and hopefully those lecture + + + align:start position:0% +happens and hopefully those lecture +notes will help fill that in + + align:start position:0% +notes will help fill that in + + + align:start position:0% +notes will help fill that in +for those of you who want to dig in a + + align:start position:0% +for those of you who want to dig in a + + + align:start position:0% +for those of you who want to dig in a +bit more so that's our plan for today + + align:start position:0% +bit more so that's our plan for today + + + align:start position:0% +bit more so that's our plan for today +so just to remind ourselves again coming + + align:start position:0% +so just to remind ourselves again coming + + + align:start position:0% +so just to remind ourselves again coming +looking back to the previous class + + align:start position:0% +looking back to the previous class + + + align:start position:0% +looking back to the previous class +session + + align:start position:0% +session + + + align:start position:0% +session +starting in the spring of 1925 after + + align:start position:0% +starting in the spring of 1925 after + + + align:start position:0% +starting in the spring of 1925 after +that kind of uh bout of severe hay fever + + align:start position:0% +that kind of uh bout of severe hay fever + + + align:start position:0% +that kind of uh bout of severe hay fever +that chased Vander Heisenberg + + align:start position:0% +that chased Vander Heisenberg + + + align:start position:0% +that chased Vander Heisenberg +temporarily out of Copenhagen and to + + align:start position:0% +temporarily out of Copenhagen and to + + + align:start position:0% +temporarily out of Copenhagen and to +this uh really quite lovely looking + + align:start position:0% +this uh really quite lovely looking + + + align:start position:0% +this uh really quite lovely looking +island of Helga land uh in the North Sea + + align:start position:0% +island of Helga land uh in the North Sea + + + align:start position:0% +island of Helga land uh in the North Sea +uh during that span of spring and summer + + align:start position:0% +uh during that span of spring and summer + + + align:start position:0% +uh during that span of spring and summer +25 Heisenberg introduced a new a whole + + align:start position:0% +25 Heisenberg introduced a new a whole + + + align:start position:0% +25 Heisenberg introduced a new a whole +new way of trying to think about Quantum + + align:start position:0% +new way of trying to think about Quantum + + + align:start position:0% +new way of trying to think about Quantum +Theory this was now + + align:start position:0% +Theory this was now + + + align:start position:0% +Theory this was now +something like 25 years into various + + align:start position:0% +something like 25 years into various + + + align:start position:0% +something like 25 years into various +physicists grappling with something + + align:start position:0% +physicists grappling with something + + + align:start position:0% +physicists grappling with something +having to do with quantum theory going + + align:start position:0% +having to do with quantum theory going + + + align:start position:0% +having to do with quantum theory going +back to Max Planck's work that was first + + align:start position:0% +back to Max Planck's work that was first + + + align:start position:0% +back to Max Planck's work that was first +published in 1900 we saw through our + + align:start position:0% +published in 1900 we saw through our + + + align:start position:0% +published in 1900 we saw through our +several kind of moments of sitting with + + align:start position:0% +several kind of moments of sitting with + + + align:start position:0% +several kind of moments of sitting with +with what was called the old quantum + + align:start position:0% +with what was called the old quantum + + + align:start position:0% +with what was called the old quantum +theory that it wasn't quite so obvious + + align:start position:0% +theory that it wasn't quite so obvious + + + align:start position:0% +theory that it wasn't quite so obvious +that that + + align:start position:0% +that that + + + align:start position:0% +that that +collection of ideas was adding up to any + + align:start position:0% +collection of ideas was adding up to any + + + align:start position:0% +collection of ideas was adding up to any +one new thing or that they'd even fit + + align:start position:0% +one new thing or that they'd even fit + + + align:start position:0% +one new thing or that they'd even fit +together and that was a concern that + + align:start position:0% +together and that was a concern that + + + align:start position:0% +together and that was a concern that +people like Heisenberg and some of his + + align:start position:0% +people like Heisenberg and some of his + + + align:start position:0% +people like Heisenberg and some of his +young colleagues really sought to tackle + + align:start position:0% +young colleagues really sought to tackle + + + align:start position:0% +young colleagues really sought to tackle +they wanted to have a first principles + + align:start position:0% +they wanted to have a first principles + + + align:start position:0% +they wanted to have a first principles +approach to Quantum Theory a quantum + + align:start position:0% +approach to Quantum Theory a quantum + + + align:start position:0% +approach to Quantum Theory a quantum +mechanics rather than what looked + + align:start position:0% +mechanics rather than what looked + + + align:start position:0% +mechanics rather than what looked +already to them as well as to many of us + + align:start position:0% +already to them as well as to many of us + + + align:start position:0% +already to them as well as to many of us +today this kind of grab bag uh which + + align:start position:0% +today this kind of grab bag uh which + + + align:start position:0% +today this kind of grab bag uh which +which had characterized the so-called + + align:start position:0% +which had characterized the so-called + + + align:start position:0% +which had characterized the so-called +old quantum theory where people would + + align:start position:0% +old quantum theory where people would + + + align:start position:0% +old quantum theory where people would +begin with uh quite traditional + + align:start position:0% +begin with uh quite traditional + + + align:start position:0% +begin with uh quite traditional +expressions for the energy of this or + + align:start position:0% +expressions for the energy of this or + + + align:start position:0% +expressions for the energy of this or +the um + + align:start position:0% +the um + + + align:start position:0% +the um +you know a momentum of that take either + + align:start position:0% +you know a momentum of that take either + + + align:start position:0% +you know a momentum of that take either +uh Newtonian or maxwellian expressions + + align:start position:0% +uh Newtonian or maxwellian expressions + + + align:start position:0% +uh Newtonian or maxwellian expressions +and then just kind of staple on at the + + align:start position:0% +and then just kind of staple on at the + + + align:start position:0% +and then just kind of staple on at the +end some new usually not very well + + align:start position:0% +end some new usually not very well + + + align:start position:0% +end some new usually not very well +explained Quantum conditions and kind of + + align:start position:0% +explained Quantum conditions and kind of + + + align:start position:0% +explained Quantum conditions and kind of +ad hoc new rule + + align:start position:0% +ad hoc new rule + + + align:start position:0% +ad hoc new rule +and Heisenberg again his very good + + align:start position:0% +and Heisenberg again his very good + + + align:start position:0% +and Heisenberg again his very good +friend from grad school days both + + align:start position:0% +friend from grad school days both + + + align:start position:0% +friend from grad school days both +getting powerly and a lot of these + + align:start position:0% +getting powerly and a lot of these + + + align:start position:0% +getting powerly and a lot of these +younger folks were by the Year mid-1920s + + align:start position:0% +younger folks were by the Year mid-1920s + + + align:start position:0% +younger folks were by the Year mid-1920s +we're looking to do something different + + align:start position:0% +we're looking to do something different + + + align:start position:0% +we're looking to do something different +they wanted to have a first principles + + align:start position:0% +they wanted to have a first principles + + + align:start position:0% +they wanted to have a first principles +theories uh all its own that might + + align:start position:0% +theories uh all its own that might + + + align:start position:0% +theories uh all its own that might +account for phenomena at the atomic + + align:start position:0% +account for phenomena at the atomic + + + align:start position:0% +account for phenomena at the atomic +scale or smaller + + align:start position:0% +scale or smaller + + + align:start position:0% +scale or smaller +uh and and we saw last time heisberg in + + align:start position:0% +uh and and we saw last time heisberg in + + + align:start position:0% +uh and and we saw last time heisberg in +particular was Guided by by by a kind of + + align:start position:0% +particular was Guided by by by a kind of + + + align:start position:0% +particular was Guided by by by a kind of +approach that sounded very much to it + + align:start position:0% +approach that sounded very much to it + + + align:start position:0% +approach that sounded very much to it +sounded very much like + + align:start position:0% +sounded very much like + + + align:start position:0% +sounded very much like +what Albert Einstein had announced back + + align:start position:0% +what Albert Einstein had announced back + + + align:start position:0% +what Albert Einstein had announced back +in 1905 and thinking about uh the + + align:start position:0% +in 1905 and thinking about uh the + + + align:start position:0% +in 1905 and thinking about uh the +electrodynamics of moving bodies + + align:start position:0% +electrodynamics of moving bodies + + + align:start position:0% +electrodynamics of moving bodies +Heisenberg starts sounding a lot like a + + align:start position:0% +Heisenberg starts sounding a lot like a + + + align:start position:0% +Heisenberg starts sounding a lot like a +kind of um acolyte of the physicist and + + align:start position:0% +kind of um acolyte of the physicist and + + + align:start position:0% +kind of um acolyte of the physicist and +philosopher Ernst Mach so you saw in the + + align:start position:0% +philosopher Ernst Mach so you saw in the + + + align:start position:0% +philosopher Ernst Mach so you saw in the +opening pages of of Heisenberg's article + + align:start position:0% +opening pages of of Heisenberg's article + + + align:start position:0% +opening pages of of Heisenberg's article +that we had in the English translation + + align:start position:0% +that we had in the English translation + + + align:start position:0% +that we had in the English translation +in our reader then even in the opening + + align:start position:0% +in our reader then even in the opening + + + align:start position:0% +in our reader then even in the opening +paragraph he says we're we're going to + + align:start position:0% +paragraph he says we're we're going to + + + align:start position:0% +paragraph he says we're we're going to +keep fooling ourselves or or get or + + align:start position:0% +keep fooling ourselves or or get or + + + align:start position:0% +keep fooling ourselves or or get or +chasing our own Tails basically if we + + align:start position:0% +chasing our own Tails basically if we + + + align:start position:0% +chasing our own Tails basically if we +keep trying to talk about things that + + align:start position:0% +keep trying to talk about things that + + + align:start position:0% +keep trying to talk about things that +are not even in principle observable for + + align:start position:0% +are not even in principle observable for + + + align:start position:0% +are not even in principle observable for +which examples of which he mentioned + + align:start position:0% +which examples of which he mentioned + + + align:start position:0% +which examples of which he mentioned +would be things like the orbit of an + + align:start position:0% +would be things like the orbit of an + + + align:start position:0% +would be things like the orbit of an +electron in an atom we don't watch the + + align:start position:0% +electron in an atom we don't watch the + + + align:start position:0% +electron in an atom we don't watch the +electrons zooming around like a planet + + align:start position:0% +electrons zooming around like a planet + + + align:start position:0% +electrons zooming around like a planet +in the solar system let's stop trying to + + align:start position:0% +in the solar system let's stop trying to + + + align:start position:0% +in the solar system let's stop trying to +calculate those features and focus + + align:start position:0% +calculate those features and focus + + + align:start position:0% +calculate those features and focus +instead on things that really are + + align:start position:0% +instead on things that really are + + + align:start position:0% +instead on things that really are +objects of positive experience like the + + align:start position:0% +objects of positive experience like the + + + align:start position:0% +objects of positive experience like the +emission lines these spectral lines that + + align:start position:0% +emission lines these spectral lines that + + + align:start position:0% +emission lines these spectral lines that +come out when certain gases of atoms are + + align:start position:0% +come out when certain gases of atoms are + + + align:start position:0% +come out when certain gases of atoms are +excited so Eisenberg began looking at + + align:start position:0% +excited so Eisenberg began looking at + + + align:start position:0% +excited so Eisenberg began looking at +things like the observable features of + + align:start position:0% +things like the observable features of + + + align:start position:0% +things like the observable features of +these spectral lines okay so he reasoned + + align:start position:0% +these spectral lines okay so he reasoned + + + align:start position:0% +these spectral lines okay so he reasoned +then we saw in particular that since the + + align:start position:0% +then we saw in particular that since the + + + align:start position:0% +then we saw in particular that since the +frequencies of these emission lines + + align:start position:0% +frequencies of these emission lines + + + align:start position:0% +frequencies of these emission lines +especially for very simple spectral like + + align:start position:0% +especially for very simple spectral like + + + align:start position:0% +especially for very simple spectral like +for a hydrogen atom the frequencies obey + + align:start position:0% +for a hydrogen atom the frequencies obey + + + align:start position:0% +for a hydrogen atom the frequencies obey +this law of addition that one line in + + align:start position:0% +this law of addition that one line in + + + align:start position:0% +this law of addition that one line in +the Spectrum could be written the actual + + align:start position:0% +the Spectrum could be written the actual + + + align:start position:0% +the Spectrum could be written the actual +numerical frequency the number of cycles + + align:start position:0% +numerical frequency the number of cycles + + + align:start position:0% +numerical frequency the number of cycles +per second uh obeyed these kinds of + + align:start position:0% +per second uh obeyed these kinds of + + + align:start position:0% +per second uh obeyed these kinds of +relationships with their two other + + align:start position:0% +relationships with their two other + + + align:start position:0% +relationships with their two other +distinct emission lines the sum of whose + + align:start position:0% +distinct emission lines the sum of whose + + + align:start position:0% +distinct emission lines the sum of whose +frequencies would add up to this third + + align:start position:0% +frequencies would add up to this third + + + align:start position:0% +frequencies would add up to this third +one and it could be it could be extended + + align:start position:0% +one and it could be it could be extended + + + align:start position:0% +one and it could be it could be extended +Beyond just pairs threes Force fives + + align:start position:0% +Beyond just pairs threes Force fives + + + align:start position:0% +Beyond just pairs threes Force fives +that there were these + + align:start position:0% +that there were these + + + align:start position:0% +that there were these +addition relationships between the + + align:start position:0% +addition relationships between the + + + align:start position:0% +addition relationships between the +frequencies of light that really + + align:start position:0% +frequencies of light that really + + + align:start position:0% +frequencies of light that really +genuinely was emitted by these excited + + align:start position:0% +genuinely was emitted by these excited + + + align:start position:0% +genuinely was emitted by these excited +hydrogen atoms and then and then Heisman + + align:start position:0% +hydrogen atoms and then and then Heisman + + + align:start position:0% +hydrogen atoms and then and then Heisman +or reasoned that when we characterize + + align:start position:0% +or reasoned that when we characterize + + + align:start position:0% +or reasoned that when we characterize +the light uh maxwellian or otherwise the + + align:start position:0% +the light uh maxwellian or otherwise the + + + align:start position:0% +the light uh maxwellian or otherwise the +frequency appears in the exponent which + + align:start position:0% +frequency appears in the exponent which + + + align:start position:0% +frequency appears in the exponent which +suggested to Heisenberg that the + + align:start position:0% +suggested to Heisenberg that the + + + align:start position:0% +suggested to Heisenberg that the +amplitude should multiply if the if the + + align:start position:0% +amplitude should multiply if the if the + + + align:start position:0% +amplitude should multiply if the if the +frequencies are adding according to this + + align:start position:0% +frequencies are adding according to this + + + align:start position:0% +frequencies are adding according to this +law of addition and the frequencies are + + align:start position:0% +law of addition and the frequencies are + + + align:start position:0% +law of addition and the frequencies are +one way of characterizing the light that + + align:start position:0% +one way of characterizing the light that + + + align:start position:0% +one way of characterizing the light that +comes out then shouldn't the amplitudes + + align:start position:0% +comes out then shouldn't the amplitudes + + + align:start position:0% +comes out then shouldn't the amplitudes +of those Associated light waves multiply + + align:start position:0% +of those Associated light waves multiply + + + align:start position:0% +of those Associated light waves multiply +and that's what he found two of his + + align:start position:0% +and that's what he found two of his + + + align:start position:0% +and that's what he found two of his +great surprise alone on the island of + + align:start position:0% +great surprise alone on the island of + + + align:start position:0% +great surprise alone on the island of +Helga land that these amplitudes didn't + + align:start position:0% +Helga land that these amplitudes didn't + + + align:start position:0% +Helga land that these amplitudes didn't +behave the way he expected them to in + + align:start position:0% +behave the way he expected them to in + + + align:start position:0% +behave the way he expected them to in +fact the the outcome of multiplying two + + align:start position:0% +fact the the outcome of multiplying two + + + align:start position:0% +fact the the outcome of multiplying two +of those things together depending on + + align:start position:0% +of those things together depending on + + + align:start position:0% +of those things together depending on +the order in which they were multiplied + + align:start position:0% +the order in which they were multiplied + + + align:start position:0% +the order in which they were multiplied +uh and so he returned or started very + + align:start position:0% +uh and so he returned or started very + + + align:start position:0% +uh and so he returned or started very +soon afterwards a position in gertington + + align:start position:0% +soon afterwards a position in gertington + + + align:start position:0% +soon afterwards a position in gertington +and his senior advisor there Max Bourne + + align:start position:0% +and his senior advisor there Max Bourne + + + align:start position:0% +and his senior advisor there Max Bourne +clarified these are matrices the fact + + align:start position:0% +clarified these are matrices the fact + + + align:start position:0% +clarified these are matrices the fact +that the uh outcome of the + + align:start position:0% +that the uh outcome of the + + + align:start position:0% +that the uh outcome of the +multiplication depends on the order is a + + align:start position:0% +multiplication depends on the order is a + + + align:start position:0% +multiplication depends on the order is a +generic feature of matrices whereas + + align:start position:0% +generic feature of matrices whereas + + + align:start position:0% +generic feature of matrices whereas +mathematicians would say matrices do not + + align:start position:0% +mathematicians would say matrices do not + + + align:start position:0% +mathematicians would say matrices do not +commute and so soon after that this work + + align:start position:0% +commute and so soon after that this work + + + align:start position:0% +commute and so soon after that this work +became known as Matrix mechanics + + align:start position:0% +became known as Matrix mechanics + + + align:start position:0% +became known as Matrix mechanics +and then Heisenberg continued working on + + align:start position:0% +and then Heisenberg continued working on + + + align:start position:0% +and then Heisenberg continued working on +that uh sharpening the formalism working + + align:start position:0% +that uh sharpening the formalism working + + + align:start position:0% +that uh sharpening the formalism working +directly with maxborn and some other + + align:start position:0% +directly with maxborn and some other + + + align:start position:0% +directly with maxborn and some other +colleagues but also trying to figure out + + align:start position:0% +colleagues but also trying to figure out + + + align:start position:0% +colleagues but also trying to figure out +conceptually what might it mean if the + + align:start position:0% +conceptually what might it mean if the + + + align:start position:0% +conceptually what might it mean if the +world is characterized the atomic world + + align:start position:0% +world is characterized the atomic world + + + align:start position:0% +world is characterized the atomic world +is characterized by these strange arrays + + align:start position:0% +is characterized by these strange arrays + + + align:start position:0% +is characterized by these strange arrays +of numbers whose mathematics was at + + align:start position:0% +of numbers whose mathematics was at + + + align:start position:0% +of numbers whose mathematics was at +least to him rather unexpected and + + align:start position:0% +least to him rather unexpected and + + + align:start position:0% +least to him rather unexpected and +foreign and where it seemed to be like + + align:start position:0% +foreign and where it seemed to be like + + + align:start position:0% +foreign and where it seemed to be like +the outcome would depend on the order in + + align:start position:0% +the outcome would depend on the order in + + + align:start position:0% +the outcome would depend on the order in +which you did stuff it could be that our + + align:start position:0% +which you did stuff it could be that our + + + align:start position:0% +which you did stuff it could be that our +operations on the quantum realm could + + align:start position:0% +operations on the quantum realm could + + + align:start position:0% +operations on the quantum realm could +have an impact on what we could ever see + + align:start position:0% +have an impact on what we could ever see + + + align:start position:0% +have an impact on what we could ever see +or measure and the thinking along those + + align:start position:0% +or measure and the thinking along those + + + align:start position:0% +or measure and the thinking along those +lines about what would it take to + + align:start position:0% +lines about what would it take to + + + align:start position:0% +lines about what would it take to +perform certain kinds of measurements of + + align:start position:0% +perform certain kinds of measurements of + + + align:start position:0% +perform certain kinds of measurements of +things like an electron + + align:start position:0% +things like an electron + + + align:start position:0% +things like an electron +uh scattering heinergy light off of it + + align:start position:0% +uh scattering heinergy light off of it + + + align:start position:0% +uh scattering heinergy light off of it +and so on uh that he that Heisenberg + + align:start position:0% +and so on uh that he that Heisenberg + + + align:start position:0% +and so on uh that he that Heisenberg +began to articulate his uncertainty + + align:start position:0% +began to articulate his uncertainty + + + align:start position:0% +began to articulate his uncertainty +principle uh that there's there seemed + + align:start position:0% +principle uh that there's there seemed + + + align:start position:0% +principle uh that there's there seemed +to be a consequence of the fact that + + align:start position:0% +to be a consequence of the fact that + + + align:start position:0% +to be a consequence of the fact that +these matrices uh don't commute with + + align:start position:0% +these matrices uh don't commute with + + + align:start position:0% +these matrices uh don't commute with +each other + + align:start position:0% +each other + + + align:start position:0% +each other +there was an irreducible uncertainty in + + align:start position:0% +there was an irreducible uncertainty in + + + align:start position:0% +there was an irreducible uncertainty in +the sharpness uh the accuracy or + + align:start position:0% +the sharpness uh the accuracy or + + + align:start position:0% +the sharpness uh the accuracy or +Precision with which we could ever + + align:start position:0% +Precision with which we could ever + + + align:start position:0% +Precision with which we could ever +specify at the same moment the position + + align:start position:0% +specify at the same moment the position + + + align:start position:0% +specify at the same moment the position +of say an electron uh and its + + align:start position:0% +of say an electron uh and its + + + align:start position:0% +of say an electron uh and its +simultaneous momentum along the X + + align:start position:0% +simultaneous momentum along the X + + + align:start position:0% +simultaneous momentum along the X +direction that there was a trade-off + + align:start position:0% +direction that there was a trade-off + + + align:start position:0% +direction that there was a trade-off +whose scale like so many of these things + + align:start position:0% +whose scale like so many of these things + + + align:start position:0% +whose scale like so many of these things +was set by planks Cuts so that was what + + align:start position:0% +was set by planks Cuts so that was what + + + align:start position:0% +was set by planks Cuts so that was what +we mostly looked at last time and as I + + align:start position:0% +we mostly looked at last time and as I + + + align:start position:0% +we mostly looked at last time and as I +as I gave a kind of foreshadowing for + + align:start position:0% +as I gave a kind of foreshadowing for + + + align:start position:0% +as I gave a kind of foreshadowing for +today right around that same time in + + align:start position:0% +today right around that same time in + + + align:start position:0% +today right around that same time in +just a remarkably close + + align:start position:0% +just a remarkably close + + + align:start position:0% +just a remarkably close +um span of of weeks and months + + align:start position:0% +um span of of weeks and months + + + align:start position:0% +um span of of weeks and months +there was a really quite different + + align:start position:0% +there was a really quite different + + + align:start position:0% +there was a really quite different +approach to some of those very same + + align:start position:0% +approach to some of those very same + + + align:start position:0% +approach to some of those very same +questions being worked out by Verna + + align:start position:0% +questions being worked out by Verna + + + align:start position:0% +questions being worked out by Verna +Heisenberg and we had an excerpt from + + align:start position:0% +Heisenberg and we had an excerpt from + + + align:start position:0% +Heisenberg and we had an excerpt from +this really quite a wonderful biography + + align:start position:0% +this really quite a wonderful biography + + + align:start position:0% +this really quite a wonderful biography +by uh Walter Moore part of today's + + align:start position:0% +by uh Walter Moore part of today's + + + align:start position:0% +by uh Walter Moore part of today's +readings was a little section of Moore's + + align:start position:0% +readings was a little section of Moore's + + + align:start position:0% +readings was a little section of Moore's +book talking through how did trojaner + + align:start position:0% +book talking through how did trojaner + + + align:start position:0% +book talking through how did trojaner +think about what became known as wave + + align:start position:0% +think about what became known as wave + + + align:start position:0% +think about what became known as wave +mechanics so I want to talk a little bit + + align:start position:0% +mechanics so I want to talk a little bit + + + align:start position:0% +mechanics so I want to talk a little bit +about that + + align:start position:0% +about that + + + align:start position:0% +about that +so this was happening not in the spring + + align:start position:0% +so this was happening not in the spring + + + align:start position:0% +so this was happening not in the spring +summer of 25 but in sort of winter + + align:start position:0% +summer of 25 but in sort of winter + + + align:start position:0% +summer of 25 but in sort of winter +spring 26 but really just a few months + + align:start position:0% +spring 26 but really just a few months + + + align:start position:0% +spring 26 but really just a few months +later + + align:start position:0% +later + + + align:start position:0% +later +um Aaron Schrodinger began introducing a + + align:start position:0% +um Aaron Schrodinger began introducing a + + + align:start position:0% +um Aaron Schrodinger began introducing a +different first principles approach to + + align:start position:0% +different first principles approach to + + + align:start position:0% +different first principles approach to +Quantum Theory much like Heisenberg and + + align:start position:0% +Quantum Theory much like Heisenberg and + + + align:start position:0% +Quantum Theory much like Heisenberg and +Paulie and these other kind of young + + align:start position:0% +Paulie and these other kind of young + + + align:start position:0% +Paulie and these other kind of young +young uh researchers Schrodinger also + + align:start position:0% +young uh researchers Schrodinger also + + + align:start position:0% +young uh researchers Schrodinger also +thought there should be a kind of way of + + align:start position:0% +thought there should be a kind of way of + + + align:start position:0% +thought there should be a kind of way of +building a a new Theory from the ground + + align:start position:0% +building a a new Theory from the ground + + + align:start position:0% +building a a new Theory from the ground +up to treat the behavior of atoms in + + align:start position:0% +up to treat the behavior of atoms in + + + align:start position:0% +up to treat the behavior of atoms in +parts of atoms but he followed a + + align:start position:0% +parts of atoms but he followed a + + + align:start position:0% +parts of atoms but he followed a +different conceptual path he was working + + align:start position:0% +different conceptual path he was working + + + align:start position:0% +different conceptual path he was working +quite independently of Heisenberg in + + align:start position:0% +quite independently of Heisenberg in + + + align:start position:0% +quite independently of Heisenberg in +these early steps + + align:start position:0% +these early steps + + + align:start position:0% +these early steps +so Heisenberg had built upon these ideas + + align:start position:0% +so Heisenberg had built upon these ideas + + + align:start position:0% +so Heisenberg had built upon these ideas +about discreetness uh he was influenced + + align:start position:0% +about discreetness uh he was influenced + + + align:start position:0% +about discreetness uh he was influenced +by Bohr's work and ultimately tried to + + align:start position:0% +by Bohr's work and ultimately tried to + + + align:start position:0% +by Bohr's work and ultimately tried to +kind of extract away from Bohr's work uh + + align:start position:0% +kind of extract away from Bohr's work uh + + + align:start position:0% +kind of extract away from Bohr's work uh +but Schrodinger actually went a + + align:start position:0% +but Schrodinger actually went a + + + align:start position:0% +but Schrodinger actually went a +different way he was mostly inspired + + align:start position:0% +different way he was mostly inspired + + + align:start position:0% +different way he was mostly inspired +most directly inspired his work not by + + align:start position:0% +most directly inspired his work not by + + + align:start position:0% +most directly inspired his work not by +the kind of boar Adam or this notion of + + align:start position:0% +the kind of boar Adam or this notion of + + + align:start position:0% +the kind of boar Adam or this notion of +kind of very rigid discrete + + align:start position:0% +kind of very rigid discrete + + + align:start position:0% +kind of very rigid discrete +Quantum jobs but rather by Louis de + + align:start position:0% +Quantum jobs but rather by Louis de + + + align:start position:0% +Quantum jobs but rather by Louis de +brois a very suggestive idea from 1924 + + align:start position:0% +brois a very suggestive idea from 1924 + + + align:start position:0% +brois a very suggestive idea from 1924 +about matter waves and here's this again + + align:start position:0% +about matter waves and here's this again + + + align:start position:0% +about matter waves and here's this again +kind of cartoon version of the bottom + + align:start position:0% +kind of cartoon version of the bottom + + + align:start position:0% +kind of cartoon version of the bottom +here + + align:start position:0% +here + + + align:start position:0% +here +trying to show Dubois suggestion for why + + align:start position:0% +trying to show Dubois suggestion for why + + + align:start position:0% +trying to show Dubois suggestion for why +these very discreet orbits that Niels + + align:start position:0% +these very discreet orbits that Niels + + + align:start position:0% +these very discreet orbits that Niels +Bohr had identified of say the uh the + + align:start position:0% +Bohr had identified of say the uh the + + + align:start position:0% +Bohr had identified of say the uh the +behavior of an electron in the hydrogen + + align:start position:0% +behavior of an electron in the hydrogen + + + align:start position:0% +behavior of an electron in the hydrogen +atom why might those special orbits be + + align:start position:0% +atom why might those special orbits be + + + align:start position:0% +atom why might those special orbits be +picked out as stable maybe there was an + + align:start position:0% +picked out as stable maybe there was an + + + align:start position:0% +picked out as stable maybe there was an +inherent waviness of the electron and + + align:start position:0% +inherent waviness of the electron and + + + align:start position:0% +inherent waviness of the electron and +you had to have a constructive + + align:start position:0% +you had to have a constructive + + + align:start position:0% +you had to have a constructive +interference for a stable orbit anything + + align:start position:0% +interference for a stable orbit anything + + + align:start position:0% +interference for a stable orbit anything +else would suffer destructiveness those + + align:start position:0% +else would suffer destructiveness those + + + align:start position:0% +else would suffer destructiveness those +are the kinds of things that really + + align:start position:0% +are the kinds of things that really + + + align:start position:0% +are the kinds of things that really +caught Schrodinger's imagination very + + align:start position:0% +caught Schrodinger's imagination very + + + align:start position:0% +caught Schrodinger's imagination very +soon after devroy himself had introduced + + align:start position:0% +soon after devroy himself had introduced + + + align:start position:0% +soon after devroy himself had introduced +them + + align:start position:0% +them + + + align:start position:0% +them +so Schrodinger was coming from a bit of + + align:start position:0% +so Schrodinger was coming from a bit of + + + align:start position:0% +so Schrodinger was coming from a bit of +a different Community he was originally + + align:start position:0% +a different Community he was originally + + + align:start position:0% +a different Community he was originally +from Vienna he was at the time teaching + + align:start position:0% +from Vienna he was at the time teaching + + + align:start position:0% +from Vienna he was at the time teaching +in Zurich he wasn't from Copenhagen he + + align:start position:0% +in Zurich he wasn't from Copenhagen he + + + align:start position:0% +in Zurich he wasn't from Copenhagen he +wasn't working in gerting and he was a + + align:start position:0% +wasn't working in gerting and he was a + + + align:start position:0% +wasn't working in gerting and he was a +little bit uh kind of different network + + align:start position:0% +little bit uh kind of different network + + + align:start position:0% +little bit uh kind of different network +perhaps more important he was also a + + align:start position:0% +perhaps more important he was also a + + + align:start position:0% +perhaps more important he was also a +generation older than Heisenberg and + + align:start position:0% +generation older than Heisenberg and + + + align:start position:0% +generation older than Heisenberg and +Paul he was basically very nearly the + + align:start position:0% +Paul he was basically very nearly the + + + align:start position:0% +Paul he was basically very nearly the +same age as Albert Einstein they became + + align:start position:0% +same age as Albert Einstein they became + + + align:start position:0% +same age as Albert Einstein they became +very close friends closer in age to + + align:start position:0% +very close friends closer in age to + + + align:start position:0% +very close friends closer in age to +Niels Bohr he'd been working as a + + align:start position:0% +Niels Bohr he'd been working as a + + + align:start position:0% +Niels Bohr he'd been working as a +professional theoretical physicist for + + align:start position:0% +professional theoretical physicist for + + + align:start position:0% +professional theoretical physicist for +decades by the time this stuff came up + + align:start position:0% +decades by the time this stuff came up + + + align:start position:0% +decades by the time this stuff came up +unlike Heisenberg and Paulie who were + + align:start position:0% +unlike Heisenberg and Paulie who were + + + align:start position:0% +unlike Heisenberg and Paulie who were +very very close uh who were working very + + align:start position:0% +very very close uh who were working very + + + align:start position:0% +very very close uh who were working very +soon after their own phds Schrodinger + + align:start position:0% +soon after their own phds Schrodinger + + + align:start position:0% +soon after their own phds Schrodinger +was was a kind of established researcher + + align:start position:0% +was was a kind of established researcher + + + align:start position:0% +was was a kind of established researcher +and and his approach to this question I + + align:start position:0% +and and his approach to this question I + + + align:start position:0% +and and his approach to this question I +think sort of shows that you we could + + align:start position:0% +think sort of shows that you we could + + + align:start position:0% +think sort of shows that you we could +characterize his approach to the new + + align:start position:0% +characterize his approach to the new + + + align:start position:0% +characterize his approach to the new +quantum mechanics the new Quantum realm + + align:start position:0% +quantum mechanics the new Quantum realm + + + align:start position:0% +quantum mechanics the new Quantum realm +as an effort to sort of retain as much + + align:start position:0% +as an effort to sort of retain as much + + + align:start position:0% +as an effort to sort of retain as much +of of the kind of look and feel of the + + align:start position:0% +of of the kind of look and feel of the + + + align:start position:0% +of of the kind of look and feel of the +toolkit of time-tested physics as he + + align:start position:0% +toolkit of time-tested physics as he + + + align:start position:0% +toolkit of time-tested physics as he +could + + align:start position:0% +could + + + align:start position:0% +could +and I'm just going to pause briefly and + + align:start position:0% +and I'm just going to pause briefly and + + + align:start position:0% +and I'm just going to pause briefly and +mention some of you might know uh so for + + align:start position:0% +mention some of you might know uh so for + + + align:start position:0% +mention some of you might know uh so for +the tool kits Heisenberg introding will + + align:start position:0% +the tool kits Heisenberg introding will + + + align:start position:0% +the tool kits Heisenberg introding will +look very distinct with schroingers + + align:start position:0% +look very distinct with schroingers + + + align:start position:0% +look very distinct with schroingers +seeming to be a little bit more almost + + align:start position:0% +seeming to be a little bit more almost + + + align:start position:0% +seeming to be a little bit more almost +conservative in the sense of let's + + align:start position:0% +conservative in the sense of let's + + + align:start position:0% +conservative in the sense of let's +retain as much as possible and + + align:start position:0% +retain as much as possible and + + + align:start position:0% +retain as much as possible and +Heisenberg saying you know it's a new + + align:start position:0% +Heisenberg saying you know it's a new + + + align:start position:0% +Heisenberg saying you know it's a new +it's a new world we need a conceptual + + align:start position:0% +it's a new world we need a conceptual + + + align:start position:0% +it's a new world we need a conceptual +Revolution we'll use new new techniques + + align:start position:0% +Revolution we'll use new new techniques + + + align:start position:0% +Revolution we'll use new new techniques +and yet socially and personally they + + align:start position:0% +and yet socially and personally they + + + align:start position:0% +and yet socially and personally they +were almost inverted so Schrodinger even + + align:start position:0% +were almost inverted so Schrodinger even + + + align:start position:0% +were almost inverted so Schrodinger even +in his day was known as as a remarkably + + align:start position:0% +in his day was known as as a remarkably + + + align:start position:0% +in his day was known as as a remarkably +um uh + + align:start position:0% +um uh + + + align:start position:0% +um uh +sort of uh Bohemian leading a Bohemian + + align:start position:0% +sort of uh Bohemian leading a Bohemian + + + align:start position:0% +sort of uh Bohemian leading a Bohemian +lifestyle not the kind of traditional + + align:start position:0% +lifestyle not the kind of traditional + + + align:start position:0% +lifestyle not the kind of traditional +Family Values he had open relationships + + align:start position:0% +Family Values he had open relationships + + + align:start position:0% +Family Values he had open relationships +with multiple within a Time + + align:start position:0% +with multiple within a Time + + + align:start position:0% +with multiple within a Time +he raised children from that he had with + + align:start position:0% +he raised children from that he had with + + + align:start position:0% +he raised children from that he had with +one person raised them with his with his + + align:start position:0% +one person raised them with his with his + + + align:start position:0% +one person raised them with his with his +wife and I mean it was a really unusual + + align:start position:0% +wife and I mean it was a really unusual + + + align:start position:0% +wife and I mean it was a really unusual +Arrangement that actually his own + + align:start position:0% +Arrangement that actually his own + + + align:start position:0% +Arrangement that actually his own +contemporaries thought would talk about + + align:start position:0% +contemporaries thought would talk about + + + align:start position:0% +contemporaries thought would talk about +and stood out and Heisenberg as we know + + align:start position:0% +and stood out and Heisenberg as we know + + + align:start position:0% +and stood out and Heisenberg as we know +was pursuing actually very fairly to + + align:start position:0% +was pursuing actually very fairly to + + + align:start position:0% +was pursuing actually very fairly to +traditional stereotypical kind of + + align:start position:0% +traditional stereotypical kind of + + + align:start position:0% +traditional stereotypical kind of +personal family life so so who's + + align:start position:0% +personal family life so so who's + + + align:start position:0% +personal family life so so who's +conservative whose radical actually sort + + align:start position:0% +conservative whose radical actually sort + + + align:start position:0% +conservative whose radical actually sort +of uh different about what kinds of + + align:start position:0% +of uh different about what kinds of + + + align:start position:0% +of uh different about what kinds of +aspects of their life and work we're + + align:start position:0% +aspects of their life and work we're + + + align:start position:0% +aspects of their life and work we're +trying to characterize and again Moore's + + align:start position:0% +trying to characterize and again Moore's + + + align:start position:0% +trying to characterize and again Moore's +biography I think is really quite quite + + align:start position:0% +biography I think is really quite quite + + + align:start position:0% +biography I think is really quite quite +astonishing for this rounded view of + + align:start position:0% +astonishing for this rounded view of + + + align:start position:0% +astonishing for this rounded view of +schroederer not only how he got to a few + + align:start position:0% +schroederer not only how he got to a few + + + align:start position:0% +schroederer not only how he got to a few +equations so I recommend that uh more of + + align:start position:0% +equations so I recommend that uh more of + + + align:start position:0% +equations so I recommend that uh more of +the book you might enjoy Beyond just the + + align:start position:0% +the book you might enjoy Beyond just the + + + align:start position:0% +the book you might enjoy Beyond just the +excerpt that I gave okay what you're + + align:start position:0% +excerpt that I gave okay what you're + + + align:start position:0% +excerpt that I gave okay what you're +going to do so we know from his own + + align:start position:0% +going to do so we know from his own + + + align:start position:0% +going to do so we know from his own +private notebooks that have survived + + align:start position:0% +private notebooks that have survived + + + align:start position:0% +private notebooks that have survived +this work was happening in sort of + + align:start position:0% +this work was happening in sort of + + + align:start position:0% +this work was happening in sort of +December 1925 uh January 1926 really + + align:start position:0% +December 1925 uh January 1926 really + + + align:start position:0% +December 1925 uh January 1926 really +just roughly half a year after shorting + + align:start position:0% +just roughly half a year after shorting + + + align:start position:0% +just roughly half a year after shorting +his first Publications Schrodinger began + + align:start position:0% +his first Publications Schrodinger began + + + align:start position:0% +his first Publications Schrodinger began +with the usual expression for energy + + align:start position:0% +with the usual expression for energy + + + align:start position:0% +with the usual expression for energy +just the sort of Newtonian expression + + align:start position:0% +just the sort of Newtonian expression + + + align:start position:0% +just the sort of Newtonian expression +for + + align:start position:0% +for + + + align:start position:0% +for +the kinetic energy and the potential + + align:start position:0% +the kinetic energy and the potential + + + align:start position:0% +the kinetic energy and the potential +energy but then he immediately + + align:start position:0% +energy but then he immediately + + + align:start position:0% +energy but then he immediately +immediately tried to pick up on what de + + align:start position:0% +immediately tried to pick up on what de + + + align:start position:0% +immediately tried to pick up on what de +bruy had suggested uh about these matter + + align:start position:0% +bruy had suggested uh about these matter + + + align:start position:0% +bruy had suggested uh about these matter +waves and so short here it was again + + align:start position:0% +waves and so short here it was again + + + align:start position:0% +waves and so short here it was again +very uh senior very Seasons mathematical + + align:start position:0% +very uh senior very Seasons mathematical + + + align:start position:0% +very uh senior very Seasons mathematical +physicist by this point reason that if + + align:start position:0% +physicist by this point reason that if + + + align:start position:0% +physicist by this point reason that if +if something about waves something about + + align:start position:0% +if something about waves something about + + + align:start position:0% +if something about waves something about +matter waves is going to be so important + + align:start position:0% +matter waves is going to be so important + + + align:start position:0% +matter waves is going to be so important +moving forward well let's use what we + + align:start position:0% +moving forward well let's use what we + + + align:start position:0% +moving forward well let's use what we +know about how to quantitatively + + align:start position:0% +know about how to quantitatively + + + align:start position:0% +know about how to quantitatively +characterize the behavior of waves so we + + align:start position:0% +characterize the behavior of waves so we + + + align:start position:0% +characterize the behavior of waves so we +did he went in a kind of wranglerish way + + align:start position:0% +did he went in a kind of wranglerish way + + + align:start position:0% +did he went in a kind of wranglerish way +and said well let's consider a wave + + align:start position:0% +and said well let's consider a wave + + + align:start position:0% +and said well let's consider a wave +equation how would we characterize for + + align:start position:0% +equation how would we characterize for + + + align:start position:0% +equation how would we characterize for +example the behavior of a standing wave + + align:start position:0% +example the behavior of a standing wave + + + align:start position:0% +example the behavior of a standing wave +and we would write down this very simple + + align:start position:0% +and we would write down this very simple + + + align:start position:0% +and we would write down this very simple +looking expression simple certainly to + + align:start position:0% +looking expression simple certainly to + + + align:start position:0% +looking expression simple certainly to +someone like schroding are very familiar + + align:start position:0% +someone like schroding are very familiar + + + align:start position:0% +someone like schroding are very familiar +and as many of you probably know we saw + + align:start position:0% +and as many of you probably know we saw + + + align:start position:0% +and as many of you probably know we saw +briefly in some earlier lectures this uh + + align:start position:0% +briefly in some earlier lectures this uh + + + align:start position:0% +briefly in some earlier lectures this uh +parameter K here is called The Wave + + align:start position:0% +parameter K here is called The Wave + + + align:start position:0% +parameter K here is called The Wave +number it's inversely proportional to + + align:start position:0% +number it's inversely proportional to + + + align:start position:0% +number it's inversely proportional to +the wavelength so we can characterize + + align:start position:0% +the wavelength so we can characterize + + + align:start position:0% +the wavelength so we can characterize +the behavior of any kind of wave in + + align:start position:0% +the behavior of any kind of wave in + + + align:start position:0% +the behavior of any kind of wave in +terms of a wavelength and ask how is the + + align:start position:0% +terms of a wavelength and ask how is the + + + align:start position:0% +terms of a wavelength and ask how is the +amplitude of that wave kind of changing + + align:start position:0% +amplitude of that wave kind of changing + + + align:start position:0% +amplitude of that wave kind of changing +over time oh excuse me across space how + + align:start position:0% +over time oh excuse me across space how + + + align:start position:0% +over time oh excuse me across space how +is the wave + + align:start position:0% +is the wave + + + align:start position:0% +is the wave +behaving as we move from one position to + + align:start position:0% +behaving as we move from one position to + + + align:start position:0% +behaving as we move from one position to +the other and that's what this + + align:start position:0% +the other and that's what this + + + align:start position:0% +the other and that's what this +expression is is quantifying + + align:start position:0% +expression is is quantifying + + + align:start position:0% +expression is is quantifying +but now de broy had said there was + + align:start position:0% +but now de broy had said there was + + + align:start position:0% +but now de broy had said there was +something very specific about a + + align:start position:0% +something very specific about a + + + align:start position:0% +something very specific about a +wavelength for matter the debris + + align:start position:0% +wavelength for matter the debris + + + align:start position:0% +wavelength for matter the debris +wavelength it should be proportional to + + align:start position:0% +wavelength it should be proportional to + + + align:start position:0% +wavelength it should be proportional to +Roy suggested to Planck's Constant and + + align:start position:0% +Roy suggested to Planck's Constant and + + + align:start position:0% +Roy suggested to Planck's Constant and +inversely proportional to the momentum + + align:start position:0% +inversely proportional to the momentum + + + align:start position:0% +inversely proportional to the momentum +of that particle of that Quantum object + + align:start position:0% +of that particle of that Quantum object + + + align:start position:0% +of that particle of that Quantum object +so now if the wave number is related to + + align:start position:0% +so now if the wave number is related to + + + align:start position:0% +so now if the wave number is related to +a wavelength and Deborah's wavelength is + + align:start position:0% +a wavelength and Deborah's wavelength is + + + align:start position:0% +a wavelength and Deborah's wavelength is +related to a momentum it was actually + + align:start position:0% +related to a momentum it was actually + + + align:start position:0% +related to a momentum it was actually +not a very uh difficult + + align:start position:0% +not a very uh difficult + + + align:start position:0% +not a very uh difficult +so here's the steps for children to say + + align:start position:0% +so here's the steps for children to say + + + align:start position:0% +so here's the steps for children to say +maybe this K this wave number that + + align:start position:0% +maybe this K this wave number that + + + align:start position:0% +maybe this K this wave number that +appears in any old wave equation for + + align:start position:0% +appears in any old wave equation for + + + align:start position:0% +appears in any old wave equation for +classical waves of a guitar or ocean + + align:start position:0% +classical waves of a guitar or ocean + + + align:start position:0% +classical waves of a guitar or ocean +waves in the water maybe that K is + + align:start position:0% +waves in the water maybe that K is + + + align:start position:0% +waves in the water maybe that K is +actually deeply related to the momentum + + align:start position:0% +actually deeply related to the momentum + + + align:start position:0% +actually deeply related to the momentum +in a way that actually is new that comes + + align:start position:0% +in a way that actually is new that comes + + + align:start position:0% +in a way that actually is new that comes +straightly straight from De brois + + align:start position:0% +straightly straight from De brois + + + align:start position:0% +straightly straight from De brois +suggestion and if so if we can relate K + + align:start position:0% +suggestion and if so if we can relate K + + + align:start position:0% +suggestion and if so if we can relate K +to the momentum as usual scaled by + + align:start position:0% +to the momentum as usual scaled by + + + align:start position:0% +to the momentum as usual scaled by +Planck's constant here then we go back + + align:start position:0% +Planck's constant here then we go back + + + align:start position:0% +Planck's constant here then we go back +to this quite standard equation for a + + align:start position:0% +to this quite standard equation for a + + + align:start position:0% +to this quite standard equation for a +standing wave of any kind and now we + + align:start position:0% +standing wave of any kind and now we + + + align:start position:0% +standing wave of any kind and now we +want to characterize something + + align:start position:0% +want to characterize something + + + align:start position:0% +want to characterize something +specifically Quantum theoretic then we + + align:start position:0% +specifically Quantum theoretic then we + + + align:start position:0% +specifically Quantum theoretic then we +can substitute the k for the momentum + + align:start position:0% +can substitute the k for the momentum + + + align:start position:0% +can substitute the k for the momentum +with keeping track of our H bar + + align:start position:0% +with keeping track of our H bar + + + align:start position:0% +with keeping track of our H bar +and now it looks like we actually have a + + align:start position:0% +and now it looks like we actually have a + + + align:start position:0% +and now it looks like we actually have a +whole new way of thinking about the + + align:start position:0% +whole new way of thinking about the + + + align:start position:0% +whole new way of thinking about the +momentum of any Quantum object maybe the + + align:start position:0% +momentum of any Quantum object maybe the + + + align:start position:0% +momentum of any Quantum object maybe the +momentum is just a measure of the kind + + align:start position:0% +momentum is just a measure of the kind + + + align:start position:0% +momentum is just a measure of the kind +of spatial gradients of some Associated + + align:start position:0% +of spatial gradients of some Associated + + + align:start position:0% +of spatial gradients of some Associated +matter wave + + align:start position:0% +matter wave + + + align:start position:0% +matter wave +so maybe there's a whole new operator + + align:start position:0% +so maybe there's a whole new operator + + + align:start position:0% +so maybe there's a whole new operator +maybe there's a new object that tells us + + align:start position:0% +maybe there's a new object that tells us + + + align:start position:0% +maybe there's a new object that tells us +that relates the momentum of some object + + align:start position:0% +that relates the momentum of some object + + + align:start position:0% +that relates the momentum of some object +to the kind of to the gradient of its + + align:start position:0% +to the kind of to the gradient of its + + + align:start position:0% +to the kind of to the gradient of its +Associated matter wave with the with as + + align:start position:0% +Associated matter wave with the with as + + + align:start position:0% +Associated matter wave with the with as +usual the scaling the kind of sense of + + align:start position:0% +usual the scaling the kind of sense of + + + align:start position:0% +usual the scaling the kind of sense of +scale or sense of proportion provided by + + align:start position:0% +scale or sense of proportion provided by + + + align:start position:0% +scale or sense of proportion provided by +Planck's constant so what what + + align:start position:0% +Planck's constant so what what + + + align:start position:0% +Planck's constant so what what +Schrodinger was doing here was trying to + + align:start position:0% +Schrodinger was doing here was trying to + + + align:start position:0% +Schrodinger was doing here was trying to +build in an equation where where uh try + + align:start position:0% +build in an equation where where uh try + + + align:start position:0% +build in an equation where where uh try +to build up an equation where Planck's + + align:start position:0% +to build up an equation where Planck's + + + align:start position:0% +to build up an equation where Planck's +constant was kind of built in from the + + align:start position:0% +constant was kind of built in from the + + + align:start position:0% +constant was kind of built in from the +start not appended at the end not let's + + align:start position:0% +start not appended at the end not let's + + + align:start position:0% +start not appended at the end not let's +solve for some solutions then sort of + + align:start position:0% +solve for some solutions then sort of + + + align:start position:0% +solve for some solutions then sort of +smack on some new constraint but trying + + align:start position:0% +smack on some new constraint but trying + + + align:start position:0% +smack on some new constraint but trying +to build a first principles equation + + align:start position:0% +to build a first principles equation + + + align:start position:0% +to build a first principles equation +that would describe how matter behaves + + align:start position:0% +that would describe how matter behaves + + + align:start position:0% +that would describe how matter behaves +where Planck's constant is immediately + + align:start position:0% +where Planck's constant is immediately + + + align:start position:0% +where Planck's constant is immediately +kind of setting the scale from the start + + align:start position:0% +kind of setting the scale from the start + + + align:start position:0% +kind of setting the scale from the start +and so with that + + align:start position:0% +and so with that + + + align:start position:0% +and so with that +series of kind of uh of of reasonings he + + align:start position:0% +series of kind of uh of of reasonings he + + + align:start position:0% +series of kind of uh of of reasonings he +referring arrived we would Now call the + + align:start position:0% +referring arrived we would Now call the + + + align:start position:0% +referring arrived we would Now call the +time independent schroedering equation + + align:start position:0% +time independent schroedering equation + + + align:start position:0% +time independent schroedering equation +and it really was you can see where it + + align:start position:0% +and it really was you can see where it + + + align:start position:0% +and it really was you can see where it +comes from it's starting from the from + + align:start position:0% +comes from it's starting from the from + + + align:start position:0% +comes from it's starting from the from +the typical relation between kinetic and + + align:start position:0% +the typical relation between kinetic and + + + align:start position:0% +the typical relation between kinetic and +potential energy but trying to kind of + + align:start position:0% +potential energy but trying to kind of + + + align:start position:0% +potential energy but trying to kind of +plug in these insights and kind of + + align:start position:0% +plug in these insights and kind of + + + align:start position:0% +plug in these insights and kind of +quantify these insights from DuBois from + + align:start position:0% +quantify these insights from DuBois from + + + align:start position:0% +quantify these insights from DuBois from +De bruy right from the start okay so uh + + align:start position:0% +De bruy right from the start okay so uh + + + align:start position:0% +De bruy right from the start okay so uh +you many of you probably seen this + + align:start position:0% +you many of you probably seen this + + + align:start position:0% +you many of you probably seen this +before that we still call it the + + align:start position:0% +before that we still call it the + + + align:start position:0% +before that we still call it the +charging the wave equation and let's + + align:start position:0% +charging the wave equation and let's + + + align:start position:0% +charging the wave equation and let's +just talk for a few minutes about the + + align:start position:0% +just talk for a few minutes about the + + + align:start position:0% +just talk for a few minutes about the +nature of that expression first of all + + align:start position:0% +nature of that expression first of all + + + align:start position:0% +nature of that expression first of all +it's all Continuum this wave function + + align:start position:0% +it's all Continuum this wave function + + + align:start position:0% +it's all Continuum this wave function +PSI seems to behave just like any other + + align:start position:0% +PSI seems to behave just like any other + + + align:start position:0% +PSI seems to behave just like any other +wave quantity at least there's no reason + + align:start position:0% +wave quantity at least there's no reason + + + align:start position:0% +wave quantity at least there's no reason +to think it wouldn't from this + + align:start position:0% +to think it wouldn't from this + + + align:start position:0% +to think it wouldn't from this +expression it should be sort of varying + + align:start position:0% +expression it should be sort of varying + + + align:start position:0% +expression it should be sort of varying +continuously across space gently sort of + + align:start position:0% +continuously across space gently sort of + + + align:start position:0% +continuously across space gently sort of +you know having a slightly different + + align:start position:0% +you know having a slightly different + + + align:start position:0% +you know having a slightly different +value here than there there's nothing of + + align:start position:0% +value here than there there's nothing of + + + align:start position:0% +value here than there there's nothing of +a kind of inherent radical discreteness + + align:start position:0% +a kind of inherent radical discreteness + + + align:start position:0% +a kind of inherent radical discreteness +uh that we that's that sort of faces us + + align:start position:0% +uh that we that's that sort of faces us + + + align:start position:0% +uh that we that's that sort of faces us +when we look at + + align:start position:0% +when we look at + + + align:start position:0% +when we look at +Schrodinger's equation it looks like it + + align:start position:0% +Schrodinger's equation it looks like it + + + align:start position:0% +Schrodinger's equation it looks like it +other than the presence of of Planck's + + align:start position:0% +other than the presence of of Planck's + + + align:start position:0% +other than the presence of of Planck's +constant the form of the equation the + + align:start position:0% +constant the form of the equation the + + + align:start position:0% +constant the form of the equation the +mathematical form looks quite familiar + + align:start position:0% +mathematical form looks quite familiar + + + align:start position:0% +mathematical form looks quite familiar +it's a differential equation for how + + align:start position:0% +it's a differential equation for how + + + align:start position:0% +it's a differential equation for how +some quantity is going to change over + + align:start position:0% +some quantity is going to change over + + + align:start position:0% +some quantity is going to change over +space any later as you know as many of + + align:start position:0% +space any later as you know as many of + + + align:start position:0% +space any later as you know as many of +you know he introduced a Time varying + + align:start position:0% +you know he introduced a Time varying + + + align:start position:0% +you know he introduced a Time varying +version where the same quantity PSI + + align:start position:0% +version where the same quantity PSI + + + align:start position:0% +version where the same quantity PSI +could be continuously smoothly varying + + align:start position:0% +could be continuously smoothly varying + + + align:start position:0% +could be continuously smoothly varying +over time as well as across space so + + align:start position:0% +over time as well as across space so + + + align:start position:0% +over time as well as across space so +it's it's again retaining the kind of + + align:start position:0% +it's it's again retaining the kind of + + + align:start position:0% +it's it's again retaining the kind of +look and feel of Continuum based + + align:start position:0% +look and feel of Continuum based + + + align:start position:0% +look and feel of Continuum based +differential equations it doesn't have + + align:start position:0% +differential equations it doesn't have + + + align:start position:0% +differential equations it doesn't have +these kind of ad hoc discreteness + + align:start position:0% +these kind of ad hoc discreteness + + + align:start position:0% +these kind of ad hoc discreteness +um uh kind of um features that seem to + + align:start position:0% +um uh kind of um features that seem to + + + align:start position:0% +um uh kind of um features that seem to +be kind of put in By Hand by someone + + align:start position:0% +be kind of put in By Hand by someone + + + align:start position:0% +be kind of put in By Hand by someone +like Bohr in the Bohr model + + align:start position:0% +like Bohr in the Bohr model + + + align:start position:0% +like Bohr in the Bohr model +so one of his first tests and again we + + align:start position:0% +so one of his first tests and again we + + + align:start position:0% +so one of his first tests and again we +know this from his own private notebook + + align:start position:0% +know this from his own private notebook + + + align:start position:0% +know this from his own private notebook +right he was having a ski skiing + + align:start position:0% +right he was having a ski skiing + + + align:start position:0% +right he was having a ski skiing +vacation with not his wife but with two + + align:start position:0% +vacation with not his wife but with two + + + align:start position:0% +vacation with not his wife but with two +very much younger twin women in the + + align:start position:0% +very much younger twin women in the + + + align:start position:0% +very much younger twin women in the +midst of which he would take these + + align:start position:0% +midst of which he would take these + + + align:start position:0% +midst of which he would take these +breaks and try to calculate it's quite + + align:start position:0% +breaks and try to calculate it's quite + + + align:start position:0% +breaks and try to calculate it's quite +astonishing and so one of the first + + align:start position:0% +astonishing and so one of the first + + + align:start position:0% +astonishing and so one of the first +tests you knew he had to apply this + + align:start position:0% +tests you knew he had to apply this + + + align:start position:0% +tests you knew he had to apply this +formulas or two was the now time-honored + + align:start position:0% +formulas or two was the now time-honored + + + align:start position:0% +formulas or two was the now time-honored +hydrogen atom so he said what if the + + align:start position:0% +hydrogen atom so he said what if the + + + align:start position:0% +hydrogen atom so he said what if the +potential energy is not any old form but + + align:start position:0% +potential energy is not any old form but + + + align:start position:0% +potential energy is not any old form but +it's the specific form he'd need to + + align:start position:0% +it's the specific form he'd need to + + + align:start position:0% +it's the specific form he'd need to +characterize the mutual attraction + + align:start position:0% +characterize the mutual attraction + + + align:start position:0% +characterize the mutual attraction +between an electron and a proton and a + + align:start position:0% +between an electron and a proton and a + + + align:start position:0% +between an electron and a proton and a +hydrogen atom put in the coulomb + + align:start position:0% +hydrogen atom put in the coulomb + + + align:start position:0% +hydrogen atom put in the coulomb +potential + + align:start position:0% +potential + + + align:start position:0% +potential +and then he found again just on his own + + align:start position:0% +and then he found again just on his own + + + align:start position:0% +and then he found again just on his own +in this kind of ski chalet uh right + + align:start position:0% +in this kind of ski chalet uh right + + + align:start position:0% +in this kind of ski chalet uh right +around the holiday right around New + + align:start position:0% +around the holiday right around New + + + align:start position:0% +around the holiday right around New +Year's get solutions to this equation + + align:start position:0% +Year's get solutions to this equation + + + align:start position:0% +Year's get solutions to this equation +will correspond to very specific values + + align:start position:0% +will correspond to very specific values + + + align:start position:0% +will correspond to very specific values +for the energy if you notice here the + + align:start position:0% +for the energy if you notice here the + + + align:start position:0% +for the energy if you notice here the +first in this whole series of articles + + align:start position:0% +first in this whole series of articles + + + align:start position:0% +first in this whole series of articles +that he wrote were called quantization + + align:start position:0% +that he wrote were called quantization + + + align:start position:0% +that he wrote were called quantization +as an eigenvalue problem again that's a + + align:start position:0% +as an eigenvalue problem again that's a + + + align:start position:0% +as an eigenvalue problem again that's a +hint he wants to work with familiar + + align:start position:0% +hint he wants to work with familiar + + + align:start position:0% +hint he wants to work with familiar +differential equations what he's done + + align:start position:0% +differential equations what he's done + + + align:start position:0% +differential equations what he's done +here is he has some differential + + align:start position:0% +here is he has some differential + + + align:start position:0% +here is he has some differential +operators some some some uh combination + + align:start position:0% +operators some some some uh combination + + + align:start position:0% +operators some some some uh combination +of terms that that quantify the kind of + + align:start position:0% +of terms that that quantify the kind of + + + align:start position:0% +of terms that that quantify the kind of +rates of change of some continuous + + align:start position:0% +rates of change of some continuous + + + align:start position:0% +rates of change of some continuous +property that's this side and there + + align:start position:0% +property that's this side and there + + + align:start position:0% +property that's this side and there +should be some eigenvalues of that + + align:start position:0% +should be some eigenvalues of that + + + align:start position:0% +should be some eigenvalues of that +differential operator some allowable + + align:start position:0% +differential operator some allowable + + + align:start position:0% +differential operator some allowable +um uh numerical kind of coefficients + + align:start position:0% +um uh numerical kind of coefficients + + + align:start position:0% +um uh numerical kind of coefficients +that will characterize the the the + + align:start position:0% +that will characterize the the the + + + align:start position:0% +that will characterize the the the +changing across space of that quantity + + align:start position:0% +changing across space of that quantity + + + align:start position:0% +changing across space of that quantity +and so he finds just by putting in the + + align:start position:0% +and so he finds just by putting in the + + + align:start position:0% +and so he finds just by putting in the +the coulomb potential for the hydrogen + + align:start position:0% +the coulomb potential for the hydrogen + + + align:start position:0% +the coulomb potential for the hydrogen +atom that this very kind of + + align:start position:0% +atom that this very kind of + + + align:start position:0% +atom that this very kind of +generic looking or familiar kind of + + align:start position:0% +generic looking or familiar kind of + + + align:start position:0% +generic looking or familiar kind of +format of a differential equation will + + align:start position:0% +format of a differential equation will + + + align:start position:0% +format of a differential equation will +yield exactly exactly the same energy + + align:start position:0% +yield exactly exactly the same energy + + + align:start position:0% +yield exactly exactly the same energy +Spectrum exactly the same allowable + + align:start position:0% +Spectrum exactly the same allowable + + + align:start position:0% +Spectrum exactly the same allowable +values for the eigenvalues of the energy + + align:start position:0% +values for the eigenvalues of the energy + + + align:start position:0% +values for the eigenvalues of the energy +the same coefficients here that will + + align:start position:0% +the same coefficients here that will + + + align:start position:0% +the same coefficients here that will +satisfy the equation exactly the same + + align:start position:0% +satisfy the equation exactly the same + + + align:start position:0% +satisfy the equation exactly the same +series as what Bohr had found from very + + align:start position:0% +series as what Bohr had found from very + + + align:start position:0% +series as what Bohr had found from very +different starting points so therefore + + align:start position:0% +different starting points so therefore + + + align:start position:0% +different starting points so therefore +schroding's equation as well would + + align:start position:0% +schroding's equation as well would + + + align:start position:0% +schroding's equation as well would +reproduce the successes like the Balmer + + align:start position:0% +reproduce the successes like the Balmer + + + align:start position:0% +reproduce the successes like the Balmer +Spectrum it should predict precisely the + + align:start position:0% +Spectrum it should predict precisely the + + + align:start position:0% +Spectrum it should predict precisely the +same frequencies of those emission lines + + align:start position:0% +same frequencies of those emission lines + + + align:start position:0% +same frequencies of those emission lines +from excited hydrogen atoms so schroding + + align:start position:0% +from excited hydrogen atoms so schroding + + + align:start position:0% +from excited hydrogen atoms so schroding +again had a sense that he was maybe onto + + align:start position:0% +again had a sense that he was maybe onto + + + align:start position:0% +again had a sense that he was maybe onto +something uh important here why how does + + align:start position:0% +something uh important here why how does + + + align:start position:0% +something uh important here why how does +that work and again many of you probably + + align:start position:0% +that work and again many of you probably + + + align:start position:0% +that work and again many of you probably +done these done this calculation in + + align:start position:0% +done these done this calculation in + + + align:start position:0% +done these done this calculation in +problem sets or seen it done in lecture + + align:start position:0% +problem sets or seen it done in lecture + + + align:start position:0% +problem sets or seen it done in lecture +class for others of you it's an exciting + + align:start position:0% +class for others of you it's an exciting + + + align:start position:0% +class for others of you it's an exciting +thing to look forward to + + align:start position:0% +thing to look forward to + + + align:start position:0% +thing to look forward to +so I'm not going to go through the whole + + align:start position:0% +so I'm not going to go through the whole + + + align:start position:0% +so I'm not going to go through the whole +calculation but I just want to make sure + + align:start position:0% +calculation but I just want to make sure + + + align:start position:0% +calculation but I just want to make sure +we understand the kinds of steps that + + align:start position:0% +we understand the kinds of steps that + + + align:start position:0% +we understand the kinds of steps that +Jordan was following how does this + + align:start position:0% +Jordan was following how does this + + + align:start position:0% +Jordan was following how does this +Continuum based equation this + + align:start position:0% +Continuum based equation this + + + align:start position:0% +Continuum based equation this +differential equation for some some + + align:start position:0% +differential equation for some some + + + align:start position:0% +differential equation for some some +smoothly varying quantity PSI how would + + align:start position:0% +smoothly varying quantity PSI how would + + + align:start position:0% +smoothly varying quantity PSI how would +that ever give us a discrete uh energy + + align:start position:0% +that ever give us a discrete uh energy + + + align:start position:0% +that ever give us a discrete uh energy +Spectrum how what would this with this + + align:start position:0% +Spectrum how what would this with this + + + align:start position:0% +Spectrum how what would this with this +integer n that bore had a good came from + + align:start position:0% +integer n that bore had a good came from + + + align:start position:0% +integer n that bore had a good came from +some fundamental discreetness in the + + align:start position:0% +some fundamental discreetness in the + + + align:start position:0% +some fundamental discreetness in the +behavior of electrons how does that come + + align:start position:0% +behavior of electrons how does that come + + + align:start position:0% +behavior of electrons how does that come +from Schrodinger's equation + + align:start position:0% +from Schrodinger's equation + + + align:start position:0% +from Schrodinger's equation +so let's step back and think about a + + align:start position:0% +so let's step back and think about a + + + align:start position:0% +so let's step back and think about a +simpler case involving standing waves + + align:start position:0% +simpler case involving standing waves + + + align:start position:0% +simpler case involving standing waves +let's just consider Motion One Direction + + align:start position:0% +let's just consider Motion One Direction + + + align:start position:0% +let's just consider Motion One Direction +sort of the x-axis and let's imagine we + + align:start position:0% +sort of the x-axis and let's imagine we + + + align:start position:0% +sort of the x-axis and let's imagine we +have a guitar string or a violin string + + align:start position:0% +have a guitar string or a violin string + + + align:start position:0% +have a guitar string or a violin string +where the end points are anchored so + + align:start position:0% +where the end points are anchored so + + + align:start position:0% +where the end points are anchored so +whatever the legitimate Solutions are + + align:start position:0% +whatever the legitimate Solutions are + + + align:start position:0% +whatever the legitimate Solutions are +for this wave equation PSI being say the + + align:start position:0% +for this wave equation PSI being say the + + + align:start position:0% +for this wave equation PSI being say the +amplitude of the wave in this case + + align:start position:0% +amplitude of the wave in this case + + + align:start position:0% +amplitude of the wave in this case +and the wave has to vanish at the origin + + align:start position:0% +and the wave has to vanish at the origin + + + align:start position:0% +and the wave has to vanish at the origin +and at the length L where the other end + + align:start position:0% +and at the length L where the other end + + + align:start position:0% +and at the length L where the other end +of the of the Rope or the string is + + align:start position:0% +of the of the Rope or the string is + + + align:start position:0% +of the of the Rope or the string is +anchored + + align:start position:0% +anchored + + + align:start position:0% +anchored +so how do we combine that with the + + align:start position:0% +so how do we combine that with the + + + align:start position:0% +so how do we combine that with the +general solutions for this difference + + align:start position:0% +general solutions for this difference + + + align:start position:0% +general solutions for this difference +equation here's again here's our + + align:start position:0% +equation here's again here's our + + + align:start position:0% +equation here's again here's our +differential operator so to speak + + align:start position:0% +differential operator so to speak + + + align:start position:0% +differential operator so to speak +well if we ignore the the boundary + + align:start position:0% +well if we ignore the the boundary + + + align:start position:0% +well if we ignore the the boundary +conditions if we ignore the fact that + + align:start position:0% +conditions if we ignore the fact that + + + align:start position:0% +conditions if we ignore the fact that +this string is anchored at both ends + + align:start position:0% +this string is anchored at both ends + + + align:start position:0% +this string is anchored at both ends +then we can very quickly write down the + + align:start position:0% +then we can very quickly write down the + + + align:start position:0% +then we can very quickly write down the +most General series of solutions of this + + align:start position:0% +most General series of solutions of this + + + align:start position:0% +most General series of solutions of this +wave equation it will it will oscillate + + align:start position:0% +wave equation it will it will oscillate + + + align:start position:0% +wave equation it will it will oscillate +across space like us like Sines and + + align:start position:0% +across space like us like Sines and + + + align:start position:0% +across space like us like Sines and +cosines with some characteristic wave + + align:start position:0% +cosines with some characteristic wave + + + align:start position:0% +cosines with some characteristic wave +number + + align:start position:0% +number + + + align:start position:0% +number +uh and different coefficients but now if + + align:start position:0% +uh and different coefficients but now if + + + align:start position:0% +uh and different coefficients but now if +we apply the boundary conditions then + + align:start position:0% +we apply the boundary conditions then + + + align:start position:0% +we apply the boundary conditions then +not all these Solutions are viable + + align:start position:0% +not all these Solutions are viable + + + align:start position:0% +not all these Solutions are viable +anymore some of them no longer solve the + + align:start position:0% +anymore some of them no longer solve the + + + align:start position:0% +anymore some of them no longer solve the +relevance uh irrelevant equation and in + + align:start position:0% +relevance uh irrelevant equation and in + + + align:start position:0% +relevance uh irrelevant equation and in +fact if we apply these these particular + + align:start position:0% +fact if we apply these these particular + + + align:start position:0% +fact if we apply these these particular +boundary conditions to this very general + + align:start position:0% +boundary conditions to this very general + + + align:start position:0% +boundary conditions to this very general +equation differential equation then the + + align:start position:0% +equation differential equation then the + + + align:start position:0% +equation differential equation then the +allowable Solutions have a discrete set + + align:start position:0% +allowable Solutions have a discrete set + + + align:start position:0% +allowable Solutions have a discrete set +of eigenvalues the way the the wave + + align:start position:0% +of eigenvalues the way the the wave + + + align:start position:0% +of eigenvalues the way the the wave +number K in this case becomes not annual + + align:start position:0% +number K in this case becomes not annual + + + align:start position:0% +number K in this case becomes not annual +continuous value but in fact kind of + + align:start position:0% +continuous value but in fact kind of + + + align:start position:0% +continuous value but in fact kind of +snaps into place with only integer + + align:start position:0% +snaps into place with only integer + + + align:start position:0% +snaps into place with only integer +allowed a series of of allowable wave + + align:start position:0% +allowed a series of of allowable wave + + + align:start position:0% +allowed a series of of allowable wave +numbers so the wave number could be one + + align:start position:0% +numbers so the wave number could be one + + + align:start position:0% +numbers so the wave number could be one +time some basic um reference wave number + + align:start position:0% +time some basic um reference wave number + + + align:start position:0% +time some basic um reference wave number +or two times that but not 1.8 times that + + align:start position:0% +or two times that but not 1.8 times that + + + align:start position:0% +or two times that but not 1.8 times that +we get a quantum a discrete Spectrum uh + + align:start position:0% +we get a quantum a discrete Spectrum uh + + + align:start position:0% +we get a quantum a discrete Spectrum uh +by solving a a Continuum based + + align:start position:0% +by solving a a Continuum based + + + align:start position:0% +by solving a a Continuum based +differential equation and applying the + + align:start position:0% +differential equation and applying the + + + align:start position:0% +differential equation and applying the +appropriate boundary conditions and so + + align:start position:0% +appropriate boundary conditions and so + + + align:start position:0% +appropriate boundary conditions and so +for the hydrogen atom + + align:start position:0% +for the hydrogen atom + + + align:start position:0% +for the hydrogen atom +shorting a reason similarly it wasn't + + align:start position:0% +shorting a reason similarly it wasn't + + + align:start position:0% +shorting a reason similarly it wasn't +that the electron was somehow glued in + + align:start position:0% +that the electron was somehow glued in + + + align:start position:0% +that the electron was somehow glued in +space and could only be here versus + + align:start position:0% +space and could only be here versus + + + align:start position:0% +space and could only be here versus +there like the war had suggested in this + + align:start position:0% +there like the war had suggested in this + + + align:start position:0% +there like the war had suggested in this +kind of uh ad hoc way but rather + + align:start position:0% +kind of uh ad hoc way but rather + + + align:start position:0% +kind of uh ad hoc way but rather +Schrodinger said well we're going to + + align:start position:0% +Schrodinger said well we're going to + + + align:start position:0% +Schrodinger said well we're going to +solve this differential equation for + + align:start position:0% +solve this differential equation for + + + align:start position:0% +solve this differential equation for +some general smoothly varying quantity + + align:start position:0% +some general smoothly varying quantity + + + align:start position:0% +some general smoothly varying quantity +PSI and let's apply some reasonable + + align:start position:0% +PSI and let's apply some reasonable + + + align:start position:0% +PSI and let's apply some reasonable +battery conditions that the amplitude + + align:start position:0% +battery conditions that the amplitude + + + align:start position:0% +battery conditions that the amplitude +should vanish at the origin the the + + align:start position:0% +should vanish at the origin the the + + + align:start position:0% +should vanish at the origin the the +electron should not be found in the + + align:start position:0% +electron should not be found in the + + + align:start position:0% +electron should not be found in the +nucleus uh so the so the wave function + + align:start position:0% +nucleus uh so the so the wave function + + + align:start position:0% +nucleus uh so the so the wave function +just somehow described in the electron's + + align:start position:0% +just somehow described in the electron's + + + align:start position:0% +just somehow described in the electron's +motion will vary will vanish at the + + align:start position:0% +motion will vary will vanish at the + + + align:start position:0% +motion will vary will vanish at the +origin and the electron shouldn't be + + align:start position:0% +origin and the electron shouldn't be + + + align:start position:0% +origin and the electron shouldn't be +found infinitely far away from its + + align:start position:0% +found infinitely far away from its + + + align:start position:0% +found infinitely far away from its +host's nucleus so the way the amplitude + + align:start position:0% +host's nucleus so the way the amplitude + + + align:start position:0% +host's nucleus so the way the amplitude +for whatever's waving whatever kind of + + align:start position:0% +for whatever's waving whatever kind of + + + align:start position:0% +for whatever's waving whatever kind of +debris-like matter wave is associated + + align:start position:0% +debris-like matter wave is associated + + + align:start position:0% +debris-like matter wave is associated +with electron that should have Vanishing + + align:start position:0% +with electron that should have Vanishing + + + align:start position:0% +with electron that should have Vanishing +amplitude when you're arbitrarily far + + align:start position:0% +amplitude when you're arbitrarily far + + + align:start position:0% +amplitude when you're arbitrarily far +away from the rest of the atom + + align:start position:0% +away from the rest of the atom + + + align:start position:0% +away from the rest of the atom +if you impose those boundary conditions + + align:start position:0% +if you impose those boundary conditions + + + align:start position:0% +if you impose those boundary conditions +it's a little more complicated but + + align:start position:0% +it's a little more complicated but + + + align:start position:0% +it's a little more complicated but +conceptually it's like this kind of uh + + align:start position:0% +conceptually it's like this kind of uh + + + align:start position:0% +conceptually it's like this kind of uh +standing wave on the string of fixed + + align:start position:0% +standing wave on the string of fixed + + + align:start position:0% +standing wave on the string of fixed +endpoints that's what forces a discrete + + align:start position:0% +endpoints that's what forces a discrete + + + align:start position:0% +endpoints that's what forces a discrete +Spectrum for the allowable energies not + + align:start position:0% +Spectrum for the allowable energies not + + + align:start position:0% +Spectrum for the allowable energies not +not restricting the kind of motion of + + align:start position:0% +not restricting the kind of motion of + + + align:start position:0% +not restricting the kind of motion of +the electron per se + + align:start position:0% +the electron per se + + + align:start position:0% +the electron per se +so Schrodinger now has retained the kind + + align:start position:0% +so Schrodinger now has retained the kind + + + align:start position:0% +so Schrodinger now has retained the kind +of look and feel of manipulating + + align:start position:0% +of look and feel of manipulating + + + align:start position:0% +of look and feel of manipulating +differential equations familiar for for + + align:start position:0% +differential equations familiar for for + + + align:start position:0% +differential equations familiar for for +a long time by that by that point he has + + align:start position:0% +a long time by that by that point he has + + + align:start position:0% +a long time by that by that point he has +a way of of reproducing this kind of + + align:start position:0% +a way of of reproducing this kind of + + + align:start position:0% +a way of of reproducing this kind of +inherent discreetness for things like + + align:start position:0% +inherent discreetness for things like + + + align:start position:0% +inherent discreetness for things like +the emission of these spectral lines uh + + align:start position:0% +the emission of these spectral lines uh + + + align:start position:0% +the emission of these spectral lines uh +but not by but by doing by building up + + align:start position:0% +but not by but by doing by building up + + + align:start position:0% +but not by but by doing by building up +this kind of um waviness of of nature + + align:start position:0% +this kind of um waviness of of nature + + + align:start position:0% +this kind of um waviness of of nature +from the start rather than imposing a + + align:start position:0% +from the start rather than imposing a + + + align:start position:0% +from the start rather than imposing a +kind of ad hoc Quantum condition that's + + align:start position:0% +kind of ad hoc Quantum condition that's + + + align:start position:0% +kind of ad hoc Quantum condition that's +what voting was kind of working toward + + align:start position:0% +what voting was kind of working toward + + + align:start position:0% +what voting was kind of working toward +uh in that winter of 25 26. he also then + + align:start position:0% +uh in that winter of 25 26. he also then + + + align:start position:0% +uh in that winter of 25 26. he also then +quickly realizes that solutions to his + + align:start position:0% +quickly realizes that solutions to his + + + align:start position:0% +quickly realizes that solutions to his +equation are are wave functions I should + + align:start position:0% +equation are are wave functions I should + + + align:start position:0% +equation are are wave functions I should +obey something called superposition + + align:start position:0% +obey something called superposition + + + align:start position:0% +obey something called superposition +which we've seen briefly in previous uh + + align:start position:0% +which we've seen briefly in previous uh + + + align:start position:0% +which we've seen briefly in previous uh +classes class sessions even this term if + + align:start position:0% +classes class sessions even this term if + + + align:start position:0% +classes class sessions even this term if +there was one solution to that equation + + align:start position:0% +there was one solution to that equation + + + align:start position:0% +there was one solution to that equation +and a separate solution then the sum of + + align:start position:0% +and a separate solution then the sum of + + + align:start position:0% +and a separate solution then the sum of +them will also be a solution for that + + align:start position:0% +them will also be a solution for that + + + align:start position:0% +them will also be a solution for that +matter the difference that you can take + + align:start position:0% +matter the difference that you can take + + + align:start position:0% +matter the difference that you can take +uh legitimate solutions to the wave + + align:start position:0% +uh legitimate solutions to the wave + + + align:start position:0% +uh legitimate solutions to the wave +equation and add them and the the + + align:start position:0% +equation and add them and the the + + + align:start position:0% +equation and add them and the the +resulting sum will also be a solution + + align:start position:0% +resulting sum will also be a solution + + + align:start position:0% +resulting sum will also be a solution +and that means that these wave functions + + align:start position:0% +and that means that these wave functions + + + align:start position:0% +and that means that these wave functions +could do all the things that waves do + + align:start position:0% +could do all the things that waves do + + + align:start position:0% +could do all the things that waves do +they could undergo interference for + + align:start position:0% +they could undergo interference for + + + align:start position:0% +they could undergo interference for +example + + align:start position:0% +example + + + align:start position:0% +example +and again here's just a quick example if + + align:start position:0% +and again here's just a quick example if + + + align:start position:0% +and again here's just a quick example if +you have two waves of the same amplitude + + align:start position:0% +you have two waves of the same amplitude + + + align:start position:0% +you have two waves of the same amplitude +but different uh wavelength then in + + align:start position:0% +but different uh wavelength then in + + + align:start position:0% +but different uh wavelength then in +places where the amplitudes happen to + + align:start position:0% +places where the amplitudes happen to + + + align:start position:0% +places where the amplitudes happen to +line up where Crest is near Crest and + + align:start position:0% +line up where Crest is near Crest and + + + align:start position:0% +line up where Crest is near Crest and +you add those waves together + + align:start position:0% +you add those waves together + + + align:start position:0% +you add those waves together +we'll get constructive interference the + + align:start position:0% +we'll get constructive interference the + + + align:start position:0% +we'll get constructive interference the +resulting wave will have a height nearly + + align:start position:0% +resulting wave will have a height nearly + + + align:start position:0% +resulting wave will have a height nearly +twice as tall as either wave alone on + + align:start position:0% +twice as tall as either wave alone on + + + align:start position:0% +twice as tall as either wave alone on +the other hand in other locations where + + align:start position:0% +the other hand in other locations where + + + align:start position:0% +the other hand in other locations where +a Crest is nearly lined up with a trough + + align:start position:0% +a Crest is nearly lined up with a trough + + + align:start position:0% +a Crest is nearly lined up with a trough +they'll just about cancel each other out + + align:start position:0% +they'll just about cancel each other out + + + align:start position:0% +they'll just about cancel each other out +and the resulting amps which will be + + align:start position:0% +and the resulting amps which will be + + + align:start position:0% +and the resulting amps which will be +much smaller you can have destructive + + align:start position:0% +much smaller you can have destructive + + + align:start position:0% +much smaller you can have destructive +interference all those things that are + + align:start position:0% +interference all those things that are + + + align:start position:0% +interference all those things that are +familiar from water waves from sound + + align:start position:0% +familiar from water waves from sound + + + align:start position:0% +familiar from water waves from sound +waves from light waves into maxwellian + + align:start position:0% +waves from light waves into maxwellian + + + align:start position:0% +waves from light waves into maxwellian +context all those things seem to carry + + align:start position:0% +context all those things seem to carry + + + align:start position:0% +context all those things seem to carry +over to Solutions of Schrodinger's wave + + align:start position:0% +over to Solutions of Schrodinger's wave + + + align:start position:0% +over to Solutions of Schrodinger's wave +equation as well even though it's + + align:start position:0% +equation as well even though it's + + + align:start position:0% +equation as well even though it's +seemingly describing something like an + + align:start position:0% +seemingly describing something like an + + + align:start position:0% +seemingly describing something like an +electron + + align:start position:0% +electron + + + align:start position:0% +electron +so that really uh kind of forced the + + align:start position:0% +so that really uh kind of forced the + + + align:start position:0% +so that really uh kind of forced the +question if this wave function PSI has + + align:start position:0% +question if this wave function PSI has + + + align:start position:0% +question if this wave function PSI has +definite wave-like properties what was + + align:start position:0% +definite wave-like properties what was + + + align:start position:0% +definite wave-like properties what was +it what was it a wave of or in it starts + + align:start position:0% +it what was it a wave of or in it starts + + + align:start position:0% +it what was it a wave of or in it starts +to sound like the questions about light + + align:start position:0% +to sound like the questions about light + + + align:start position:0% +to sound like the questions about light +that we began this class with + + align:start position:0% +that we began this class with + + + align:start position:0% +that we began this class with +so what what is doing the waving if PSI + + align:start position:0% +so what what is doing the waving if PSI + + + align:start position:0% +so what what is doing the waving if PSI +is uh behaves like a wave and that'll be + + align:start position:0% +is uh behaves like a wave and that'll be + + + align:start position:0% +is uh behaves like a wave and that'll be +getting even more bizarre here's we + + align:start position:0% +getting even more bizarre here's we + + + align:start position:0% +getting even more bizarre here's we +begin to break from just the familiar uh + + align:start position:0% +begin to break from just the familiar uh + + + align:start position:0% +begin to break from just the familiar uh +physics of sort of classical waves and + + align:start position:0% +physics of sort of classical waves and + + + align:start position:0% +physics of sort of classical waves and +again Schrodinger to his credit was very + + align:start position:0% +again Schrodinger to his credit was very + + + align:start position:0% +again Schrodinger to his credit was very +quick to notice this himself and really + + align:start position:0% +quick to notice this himself and really + + + align:start position:0% +quick to notice this himself and really +point it out and begin to try to try to + + align:start position:0% +point it out and begin to try to try to + + + align:start position:0% +point it out and begin to try to try to +puzzle it through + + align:start position:0% +puzzle it through + + + align:start position:0% +puzzle it through +if you consider a system with more than + + align:start position:0% +if you consider a system with more than + + + align:start position:0% +if you consider a system with more than +one electron let's say as simple as just + + align:start position:0% +one electron let's say as simple as just + + + align:start position:0% +one electron let's say as simple as just +two electrons not just one + + align:start position:0% +two electrons not just one + + + align:start position:0% +two electrons not just one +then the equation suddenly depends on + + align:start position:0% +then the equation suddenly depends on + + + align:start position:0% +then the equation suddenly depends on +many many coordinates the interaction + + align:start position:0% +many many coordinates the interaction + + + align:start position:0% +many many coordinates the interaction +potential that key portion within the + + align:start position:0% +potential that key portion within the + + + align:start position:0% +potential that key portion within the +schroding equation well now in general + + align:start position:0% +schroding equation well now in general + + + align:start position:0% +schroding equation well now in general +depend on the location of both electron + + align:start position:0% +depend on the location of both electron + + + align:start position:0% +depend on the location of both electron +one and electron two now each they're + + align:start position:0% +one and electron two now each they're + + + align:start position:0% +one and electron two now each they're +each existing in three-dimensional Space + + align:start position:0% +each existing in three-dimensional Space + + + align:start position:0% +each existing in three-dimensional Space +X Y and Z they could be at different + + align:start position:0% +X Y and Z they could be at different + + + align:start position:0% +X Y and Z they could be at different +locations so the the the potential + + align:start position:0% +locations so the the the potential + + + align:start position:0% +locations so the the the potential +energy of that two body system will now + + align:start position:0% +energy of that two body system will now + + + align:start position:0% +energy of that two body system will now +in general depend on six direct six + + align:start position:0% +in general depend on six direct six + + + align:start position:0% +in general depend on six direct six +spatial coordinates not just three + + align:start position:0% +spatial coordinates not just three + + + align:start position:0% +spatial coordinates not just three +so now Solutions PSI solutions to + + align:start position:0% +so now Solutions PSI solutions to + + + align:start position:0% +so now Solutions PSI solutions to +Schrodinger's wave equation will + + align:start position:0% +Schrodinger's wave equation will + + + align:start position:0% +Schrodinger's wave equation will +themselves depend on Six Dimensions six + + align:start position:0% +themselves depend on Six Dimensions six + + + align:start position:0% +themselves depend on Six Dimensions six +coordinates of space Not Just Three + + align:start position:0% +coordinates of space Not Just Three + + + align:start position:0% +coordinates of space Not Just Three +that's not like a water wave or a sound + + align:start position:0% +that's not like a water wave or a sound + + + align:start position:0% +that's not like a water wave or a sound +wave or a light wave + + align:start position:0% +wave or a light wave + + + align:start position:0% +wave or a light wave +so even though the mathematics was in + + align:start position:0% +so even though the mathematics was in + + + align:start position:0% +so even though the mathematics was in +many ways very familiar and Schrodinger + + align:start position:0% +many ways very familiar and Schrodinger + + + align:start position:0% +many ways very familiar and Schrodinger +used that's a great effect to find + + align:start position:0% +used that's a great effect to find + + + align:start position:0% +used that's a great effect to find +solutions to figure out why there's a + + align:start position:0% +solutions to figure out why there's a + + + align:start position:0% +solutions to figure out why there's a +seemingly quantized or discrete spectrum + + align:start position:0% +seemingly quantized or discrete spectrum + + + align:start position:0% +seemingly quantized or discrete spectrum +of eigenvalues and all that it wasn't + + align:start position:0% +of eigenvalues and all that it wasn't + + + align:start position:0% +of eigenvalues and all that it wasn't +actually just just classical waves and + + align:start position:0% +actually just just classical waves and + + + align:start position:0% +actually just just classical waves and +there were even mathematically some some + + align:start position:0% +there were even mathematically some some + + + align:start position:0% +there were even mathematically some some +unexpected features that they're + + align:start position:0% +unexpected features that they're + + + align:start position:0% +unexpected features that they're +shorting himself again to elucidate get + + align:start position:0% +shorting himself again to elucidate get + + + align:start position:0% +shorting himself again to elucidate get +PSI whatever it was was not just like a + + align:start position:0% +PSI whatever it was was not just like a + + + align:start position:0% +PSI whatever it was was not just like a +water wave in fact it seemed to live in + + align:start position:0% +water wave in fact it seemed to live in + + + align:start position:0% +water wave in fact it seemed to live in +some higher dimensional abstract + + align:start position:0% +some higher dimensional abstract + + + align:start position:0% +some higher dimensional abstract +mathematical space that would quickly + + align:start position:0% +mathematical space that would quickly + + + align:start position:0% +mathematical space that would quickly +become known as configuration space + + align:start position:0% +become known as configuration space + + + align:start position:0% +become known as configuration space +rather than the space in which we seem + + align:start position:0% +rather than the space in which we seem + + + align:start position:0% +rather than the space in which we seem +to move around every day + + align:start position:0% +to move around every day + + + align:start position:0% +to move around every day +so that was what Schrodinger began + + align:start position:0% +so that was what Schrodinger began + + + align:start position:0% +so that was what Schrodinger began +publishing as early as January 1926 he + + align:start position:0% +publishing as early as January 1926 he + + + align:start position:0% +publishing as early as January 1926 he +wrote a series of papers very very uh + + align:start position:0% +wrote a series of papers very very uh + + + align:start position:0% +wrote a series of papers very very uh +quickly one after the other in a kind of + + align:start position:0% +quickly one after the other in a kind of + + + align:start position:0% +quickly one after the other in a kind of +four-part series throughout that winter + + align:start position:0% +four-part series throughout that winter + + + align:start position:0% +four-part series throughout that winter +and spring of 1926 and so before long uh + + align:start position:0% +and spring of 1926 and so before long uh + + + align:start position:0% +and spring of 1926 and so before long uh +both Schrodinger and Heisenberg + + align:start position:0% +both Schrodinger and Heisenberg + + + align:start position:0% +both Schrodinger and Heisenberg +themselves and soon many members of this + + align:start position:0% +themselves and soon many members of this + + + align:start position:0% +themselves and soon many members of this +kind of tight-knit community uh were + + align:start position:0% +kind of tight-knit community uh were + + + align:start position:0% +kind of tight-knit community uh were +beginning to to do a kind of compare and + + align:start position:0% +beginning to to do a kind of compare and + + + align:start position:0% +beginning to to do a kind of compare and +contrast exercise there were now two + + align:start position:0% +contrast exercise there were now two + + + align:start position:0% +contrast exercise there were now two +quite different looking first principles + + align:start position:0% +quite different looking first principles + + + align:start position:0% +quite different looking first principles +um uh approaches to a new quantum theory + + align:start position:0% +um uh approaches to a new quantum theory + + + align:start position:0% +um uh approaches to a new quantum theory +on offer Heisenberg's Matrix mechanics + + align:start position:0% +on offer Heisenberg's Matrix mechanics + + + align:start position:0% +on offer Heisenberg's Matrix mechanics +uh Schrodinger's wave mechanics they + + align:start position:0% +uh Schrodinger's wave mechanics they + + + align:start position:0% +uh Schrodinger's wave mechanics they +looked nothing alike they seemed to make + + align:start position:0% +looked nothing alike they seemed to make + + + align:start position:0% +looked nothing alike they seemed to make +very different starting assumptions and + + align:start position:0% +very different starting assumptions and + + + align:start position:0% +very different starting assumptions and +they they had different kinds of strange + + align:start position:0% +they they had different kinds of strange + + + align:start position:0% +they they had different kinds of strange +features they were strange in different + + align:start position:0% +features they were strange in different + + + align:start position:0% +features they were strange in different +ways + + align:start position:0% +ways + + + align:start position:0% +ways +so Schrodinger eventually caught up with + + align:start position:0% +so Schrodinger eventually caught up with + + + align:start position:0% +so Schrodinger eventually caught up with +some of Heisenberg's papers and he added + + align:start position:0% +some of Heisenberg's papers and he added + + + align:start position:0% +some of Heisenberg's papers and he added +a footnote into one of Schrodinger's own + + align:start position:0% +a footnote into one of Schrodinger's own + + + align:start position:0% +a footnote into one of Schrodinger's own +uh follow-up articles in that first + + align:start position:0% +uh follow-up articles in that first + + + align:start position:0% +uh follow-up articles in that first +series + + align:start position:0% +series + + + align:start position:0% +series +I think this is not in his very first + + align:start position:0% +I think this is not in his very first + + + align:start position:0% +I think this is not in his very first +article but sometime later that spring + + align:start position:0% +article but sometime later that spring + + + align:start position:0% +article but sometime later that spring +in a footnote + + align:start position:0% +in a footnote + + + align:start position:0% +in a footnote +he writes as you see here my theory was + + align:start position:0% +he writes as you see here my theory was + + + align:start position:0% +he writes as you see here my theory was +inspired by Louis de broy and by short + + align:start position:0% +inspired by Louis de broy and by short + + + align:start position:0% +inspired by Louis de broy and by short +but but incomplete remarks by Albert + + align:start position:0% +but but incomplete remarks by Albert + + + align:start position:0% +but but incomplete remarks by Albert +Einstein no genetic relation whatever + + align:start position:0% +Einstein no genetic relation whatever + + + align:start position:0% +Einstein no genetic relation whatever +with Heisenberg is known to me I knew of + + align:start position:0% +with Heisenberg is known to me I knew of + + + align:start position:0% +with Heisenberg is known to me I knew of +his theory of course but felt + + align:start position:0% +his theory of course but felt + + + align:start position:0% +his theory of course but felt +discouraged not to say repelled by the + + align:start position:0% +discouraged not to say repelled by the + + + align:start position:0% +discouraged not to say repelled by the +methods of transcendental algebra what + + align:start position:0% +methods of transcendental algebra what + + + align:start position:0% +methods of transcendental algebra what +we now call matrices which appeared very + + align:start position:0% +we now call matrices which appeared very + + + align:start position:0% +we now call matrices which appeared very +difficult to me and by the lack of + + align:start position:0% +difficult to me and by the lack of + + + align:start position:0% +difficult to me and by the lack of +visualizability so that's about as rude + + align:start position:0% +visualizability so that's about as rude + + + align:start position:0% +visualizability so that's about as rude +as you can get in a footnote in a + + align:start position:0% +as you can get in a footnote in a + + + align:start position:0% +as you can get in a footnote in a +physics journal at least at that time I + + align:start position:0% +physics journal at least at that time I + + + align:start position:0% +physics journal at least at that time I +was discouraged and repelled by my + + align:start position:0% +was discouraged and repelled by my + + + align:start position:0% +was discouraged and repelled by my +colleague's work + + align:start position:0% +colleague's work + + + align:start position:0% +colleague's work +Heisenberg was a little less uh + + align:start position:0% +Heisenberg was a little less uh + + + align:start position:0% +Heisenberg was a little less uh +restrained he wrote just in a private + + align:start position:0% +restrained he wrote just in a private + + + align:start position:0% +restrained he wrote just in a private +letter to his friend Wolfgang Paoli + + align:start position:0% +letter to his friend Wolfgang Paoli + + + align:start position:0% +letter to his friend Wolfgang Paoli +around that same time just uh a little + + align:start position:0% +around that same time just uh a little + + + align:start position:0% +around that same time just uh a little +uh correspondence exchange Heisman said + + align:start position:0% +uh correspondence exchange Heisman said + + + align:start position:0% +uh correspondence exchange Heisman said +The more I reflect on the physical + + align:start position:0% +The more I reflect on the physical + + + align:start position:0% +The more I reflect on the physical +portion of Schrodinger's Theory the more + + align:start position:0% +portion of Schrodinger's Theory the more + + + align:start position:0% +portion of Schrodinger's Theory the more +disgusting I find it Russ Schrodinger + + align:start position:0% +disgusting I find it Russ Schrodinger + + + align:start position:0% +disgusting I find it Russ Schrodinger +writes on the visualizability of his + + align:start position:0% +writes on the visualizability of his + + + align:start position:0% +writes on the visualizability of his +theory I considered trash after all + + align:start position:0% +theory I considered trash after all + + + align:start position:0% +theory I considered trash after all +these waves live in sort of six or more + + align:start position:0% +these waves live in sort of six or more + + + align:start position:0% +these waves live in sort of six or more +dimensional space that seems no more + + align:start position:0% +dimensional space that seems no more + + + align:start position:0% +dimensional space that seems no more +visualizable than these abstract + + align:start position:0% +visualizable than these abstract + + + align:start position:0% +visualizable than these abstract +matrices so this is really a remarkable + + align:start position:0% +matrices so this is really a remarkable + + + align:start position:0% +matrices so this is really a remarkable +clash between two people working on very + + align:start position:0% +clash between two people working on very + + + align:start position:0% +clash between two people working on very +similar topics at the same time and + + align:start position:0% +similar topics at the same time and + + + align:start position:0% +similar topics at the same time and +finding each other's work clearly + + align:start position:0% +finding each other's work clearly + + + align:start position:0% +finding each other's work clearly +lacking not just a repulsive disgusting + + align:start position:0% +lacking not just a repulsive disgusting + + + align:start position:0% +lacking not just a repulsive disgusting +and so it was all the more surprising + + align:start position:0% +and so it was all the more surprising + + + align:start position:0% +and so it was all the more surprising +and really unexpected when several other + + align:start position:0% +and really unexpected when several other + + + align:start position:0% +and really unexpected when several other +physicists actually schroding himself + + align:start position:0% +physicists actually schroding himself + + + align:start position:0% +physicists actually schroding himself +and then two others uh Pascal yordon who + + align:start position:0% +and then two others uh Pascal yordon who + + + align:start position:0% +and then two others uh Pascal yordon who +was another young physicist about the + + align:start position:0% +was another young physicist about the + + + align:start position:0% +was another young physicist about the +same age as Heisenberg and Paulie Jordan + + align:start position:0% +same age as Heisenberg and Paulie Jordan + + + align:start position:0% +same age as Heisenberg and Paulie Jordan +was uh also a young physicist in + + align:start position:0% +was uh also a young physicist in + + + align:start position:0% +was uh also a young physicist in +gertingen so he began working directly + + align:start position:0% +gertingen so he began working directly + + + align:start position:0% +gertingen so he began working directly +with Heisenberg to elaborate Matrix + + align:start position:0% +with Heisenberg to elaborate Matrix + + + align:start position:0% +with Heisenberg to elaborate Matrix +mechanics and then separately still Paul + + align:start position:0% +mechanics and then separately still Paul + + + align:start position:0% +mechanics and then separately still Paul +durac a young uh British physicist who + + align:start position:0% +durac a young uh British physicist who + + + align:start position:0% +durac a young uh British physicist who +at this point was on a fellowship in + + align:start position:0% +at this point was on a fellowship in + + + align:start position:0% +at this point was on a fellowship in +Cambridge England all independently + + align:start position:0% +Cambridge England all independently + + + align:start position:0% +Cambridge England all independently +within a very short span of time all + + align:start position:0% +within a very short span of time all + + + align:start position:0% +within a very short span of time all +three of those physicists demonstrated + + align:start position:0% +three of those physicists demonstrated + + + align:start position:0% +three of those physicists demonstrated +by the summer of 1926 that these two + + align:start position:0% +by the summer of 1926 that these two + + + align:start position:0% +by the summer of 1926 that these two +quite different looking approaches + + align:start position:0% +quite different looking approaches + + + align:start position:0% +quite different looking approaches +Heisenberg's Matrix mechanics schroding + + align:start position:0% +Heisenberg's Matrix mechanics schroding + + + align:start position:0% +Heisenberg's Matrix mechanics schroding +his wave mechanics were actually + + align:start position:0% +his wave mechanics were actually + + + align:start position:0% +his wave mechanics were actually +mathematically equivalent you could + + align:start position:0% +mathematically equivalent you could + + + align:start position:0% +mathematically equivalent you could +actually build a mathematical kind of + + align:start position:0% +actually build a mathematical kind of + + + align:start position:0% +actually build a mathematical kind of +one-to-one mapping to any expression you + + align:start position:0% +one-to-one mapping to any expression you + + + align:start position:0% +one-to-one mapping to any expression you +might try to formulate in Matrix + + align:start position:0% +might try to formulate in Matrix + + + align:start position:0% +might try to formulate in Matrix +mechanics and put that in wave mechanics + + align:start position:0% +mechanics and put that in wave mechanics + + + align:start position:0% +mechanics and put that in wave mechanics +or vice versa so it looks disgusting and + + align:start position:0% +or vice versa so it looks disgusting and + + + align:start position:0% +or vice versa so it looks disgusting and +repulsive and uh unvisualizable one to + + align:start position:0% +repulsive and uh unvisualizable one to + + + align:start position:0% +repulsive and uh unvisualizable one to +the other between Schrodinger and + + align:start position:0% +the other between Schrodinger and + + + align:start position:0% +the other between Schrodinger and +Heisenberg I looked like these were + + align:start position:0% +Heisenberg I looked like these were + + + align:start position:0% +Heisenberg I looked like these were +really just remarkably different ways of + + align:start position:0% +really just remarkably different ways of + + + align:start position:0% +really just remarkably different ways of +trying to carve up the world and yet + + align:start position:0% +trying to carve up the world and yet + + + align:start position:0% +trying to carve up the world and yet +again within just a matter of of a few + + align:start position:0% +again within just a matter of of a few + + + align:start position:0% +again within just a matter of of a few +months uh people have found at least a + + align:start position:0% +months uh people have found at least a + + + align:start position:0% +months uh people have found at least a +mathematical bridge between them and it + + align:start position:0% +mathematical bridge between them and it + + + align:start position:0% +mathematical bridge between them and it +was that last work + + align:start position:0% +was that last work + + + align:start position:0% +was that last work +uh that really made a kind of uh again a + + align:start position:0% +uh that really made a kind of uh again a + + + align:start position:0% +uh that really made a kind of uh again a +map between Matrix and wave mechanics + + align:start position:0% +map between Matrix and wave mechanics + + + align:start position:0% +map between Matrix and wave mechanics +that really convinced people already by + + align:start position:0% +that really convinced people already by + + + align:start position:0% +that really convinced people already by +1926 to begin referring to a new single + + align:start position:0% +1926 to begin referring to a new single + + + align:start position:0% +1926 to begin referring to a new single +thing a new thing called quantum + + align:start position:0% +thing a new thing called quantum + + + align:start position:0% +thing a new thing called quantum +mechanics not just Matrix mechanics not + + align:start position:0% +mechanics not just Matrix mechanics not + + + align:start position:0% +mechanics not just Matrix mechanics not +just wave mechanics but now one thing + + align:start position:0% +just wave mechanics but now one thing + + + align:start position:0% +just wave mechanics but now one thing +called quantum mechanics and to then + + align:start position:0% +called quantum mechanics and to then + + + align:start position:0% +called quantum mechanics and to then +start using the phrase old quantum + + align:start position:0% +start using the phrase old quantum + + + align:start position:0% +start using the phrase old quantum +theory to refer to that kind of grab bag + + align:start position:0% +theory to refer to that kind of grab bag + + + align:start position:0% +theory to refer to that kind of grab bag +of techniques that we looked at uh that + + align:start position:0% +of techniques that we looked at uh that + + + align:start position:0% +of techniques that we looked at uh that +had come sort of before + + align:start position:0% +had come sort of before + + + align:start position:0% +had come sort of before +1925-26 so the new quantum mechanics was + + align:start position:0% +1925-26 so the new quantum mechanics was + + + align:start position:0% +1925-26 so the new quantum mechanics was +heralded really by that name almost in + + align:start position:0% +heralded really by that name almost in + + + align:start position:0% +heralded really by that name almost in +real time just remarkable kind of + + align:start position:0% +real time just remarkable kind of + + + align:start position:0% +real time just remarkable kind of +convergence by summer and fall of 1926. + + align:start position:0% +convergence by summer and fall of 1926. + + + align:start position:0% +convergence by summer and fall of 1926. +so I'm going to pause there I see a + + align:start position:0% +so I'm going to pause there I see a + + + align:start position:0% +so I'm going to pause there I see a +couple questions come up in the chat + + align:start position:0% +couple questions come up in the chat + + + align:start position:0% +couple questions come up in the chat +time for some other discussion any + + align:start position:0% +time for some other discussion any + + + align:start position:0% +time for some other discussion any +questions on that stuff + + align:start position:0% + + + + align:start position:0% + +so Alex asked is this is Helga land the + + align:start position:0% +so Alex asked is this is Helga land the + + + align:start position:0% +so Alex asked is this is Helga land the +same island the British tried to blow up + + align:start position:0% +same island the British tried to blow up + + + align:start position:0% +same island the British tried to blow up +after World War II I have no idea what + + align:start position:0% +after World War II I have no idea what + + + align:start position:0% +after World War II I have no idea what +happened that that's news to me it might + + align:start position:0% +happened that that's news to me it might + + + align:start position:0% +happened that that's news to me it might +be I mean Wikipedia at least could + + align:start position:0% +be I mean Wikipedia at least could + + + align:start position:0% +be I mean Wikipedia at least could +inform us I don't know + + align:start position:0% +inform us I don't know + + + align:start position:0% +inform us I don't know +um did configuration space ever become + + align:start position:0% +um did configuration space ever become + + + align:start position:0% +um did configuration space ever become +generalized to Hilbert space Fisher asks + + align:start position:0% +generalized to Hilbert space Fisher asks + + + align:start position:0% +generalized to Hilbert space Fisher asks +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +um + + align:start position:0% +um + + + align:start position:0% +um +yes I I'm not sure I'd say generalized + + align:start position:0% +yes I I'm not sure I'd say generalized + + + align:start position:0% +yes I I'm not sure I'd say generalized +too they're separately and also actually + + align:start position:0% +too they're separately and also actually + + + align:start position:0% +too they're separately and also actually +pretty soon afterwards by people like + + align:start position:0% +pretty soon afterwards by people like + + + align:start position:0% +pretty soon afterwards by people like +like Paul durac uh began trying to + + align:start position:0% +like Paul durac uh began trying to + + + align:start position:0% +like Paul durac uh began trying to +formulate this new quantum mechanics uh + + align:start position:0% +formulate this new quantum mechanics uh + + + align:start position:0% +formulate this new quantum mechanics uh +in in a in a more mathematically kind of + + align:start position:0% +in in a in a more mathematically kind of + + + align:start position:0% +in in a in a more mathematically kind of +first principles way thinking about + + align:start position:0% +first principles way thinking about + + + align:start position:0% +first principles way thinking about +vectors and Vector spaces and so on and + + align:start position:0% +vectors and Vector spaces and so on and + + + align:start position:0% +vectors and Vector spaces and so on and +that comes not only from Dirac but + + align:start position:0% +that comes not only from Dirac but + + + align:start position:0% +that comes not only from Dirac but +people like Dirac and John fonome and + + align:start position:0% +people like Dirac and John fonome and + + + align:start position:0% +people like Dirac and John fonome and +others so they were replacing + + align:start position:0% +others so they were replacing + + + align:start position:0% +others so they were replacing +configuration space per se but they were + + align:start position:0% +configuration space per se but they were + + + align:start position:0% +configuration space per se but they were +certainly trying to think more carefully + + align:start position:0% +certainly trying to think more carefully + + + align:start position:0% +certainly trying to think more carefully +about the kinds of spaces the kinds of + + align:start position:0% +about the kinds of spaces the kinds of + + + align:start position:0% +about the kinds of spaces the kinds of +mathematical spaces in which something + + align:start position:0% +mathematical spaces in which something + + + align:start position:0% +mathematical spaces in which something +like a Quantum State might reside so if + + align:start position:0% +like a Quantum State might reside so if + + + align:start position:0% +like a Quantum State might reside so if +you're thinking about a Quantum wave + + align:start position:0% +you're thinking about a Quantum wave + + + align:start position:0% +you're thinking about a Quantum wave +function that's in configuration space + + align:start position:0% +function that's in configuration space + + + align:start position:0% +function that's in configuration space +if you think about + + align:start position:0% +if you think about + + + align:start position:0% +if you think about +um a Quantum State as a kind of + + align:start position:0% +um a Quantum State as a kind of + + + align:start position:0% +um a Quantum State as a kind of +eigenvector in some abstract Hilbert + + align:start position:0% +eigenvector in some abstract Hilbert + + + align:start position:0% +eigenvector in some abstract Hilbert +space right then then that's the + + align:start position:0% +space right then then that's the + + + align:start position:0% +space right then then that's the +direction that the Iraq especially + + align:start position:0% +direction that the Iraq especially + + + align:start position:0% +direction that the Iraq especially +starts to formalize he writes an + + align:start position:0% +starts to formalize he writes an + + + align:start position:0% +starts to formalize he writes an +extraordinarily influential textbook in + + align:start position:0% +extraordinarily influential textbook in + + + align:start position:0% +extraordinarily influential textbook in +fact I showed its cover on the previous + + align:start position:0% +fact I showed its cover on the previous + + + align:start position:0% +fact I showed its cover on the previous +slide first edition 1930 that's pretty + + align:start position:0% +slide first edition 1930 that's pretty + + + align:start position:0% +slide first edition 1930 that's pretty +quick to have a textbook on stuff that + + align:start position:0% +quick to have a textbook on stuff that + + + align:start position:0% +quick to have a textbook on stuff that +was really just a few years old and then + + align:start position:0% +was really just a few years old and then + + + align:start position:0% +was really just a few years old and then +with the Hilbert spaces people began to + + align:start position:0% +with the Hilbert spaces people began to + + + align:start position:0% +with the Hilbert spaces people began to +realize these could be of of almost + + align:start position:0% +realize these could be of of almost + + + align:start position:0% +realize these could be of of almost +arbitrary Dimension so Hilbert spaces + + align:start position:0% +arbitrary Dimension so Hilbert spaces + + + align:start position:0% +arbitrary Dimension so Hilbert spaces +could be two Dimensions they could be + + align:start position:0% +could be two Dimensions they could be + + + align:start position:0% +could be two Dimensions they could be +ten thousand Dimensions they could be + + align:start position:0% +ten thousand Dimensions they could be + + + align:start position:0% +ten thousand Dimensions they could be +infinite dimensional and so in that + + align:start position:0% +infinite dimensional and so in that + + + align:start position:0% +infinite dimensional and so in that +sense they're similar to configuration + + align:start position:0% +sense they're similar to configuration + + + align:start position:0% +sense they're similar to configuration +space and not being limited to only X Y + + align:start position:0% +space and not being limited to only X Y + + + align:start position:0% +space and not being limited to only X Y +and Z but they're not quite this they're + + align:start position:0% +and Z but they're not quite this they're + + + align:start position:0% +and Z but they're not quite this they're +not exactly the same kind of thing it's + + align:start position:0% +not exactly the same kind of thing it's + + + align:start position:0% +not exactly the same kind of thing it's +really people like Paul Dirac Who start + + align:start position:0% +really people like Paul Dirac Who start + + + align:start position:0% +really people like Paul Dirac Who start +pushing very heavily in that direction + + align:start position:0% +pushing very heavily in that direction + + + align:start position:0% +pushing very heavily in that direction +uh silos with their opinions on each + + align:start position:0% +uh silos with their opinions on each + + + align:start position:0% +uh silos with their opinions on each +other's work ever change + + align:start position:0% +other's work ever change + + + align:start position:0% +other's work ever change +um that's a good question I think they + + align:start position:0% +um that's a good question I think they + + + align:start position:0% +um that's a good question I think they +stopped calling each other's work + + align:start position:0% +stopped calling each other's work + + + align:start position:0% +stopped calling each other's work +disgusting in print so that's like a + + align:start position:0% +disgusting in print so that's like a + + + align:start position:0% +disgusting in print so that's like a +plus uh and I think Schrodinger himself + + align:start position:0% +plus uh and I think Schrodinger himself + + + align:start position:0% +plus uh and I think Schrodinger himself +since he was one of the people who did + + align:start position:0% +since he was one of the people who did + + + align:start position:0% +since he was one of the people who did +find this mathematical Bridge a kind of + + align:start position:0% +find this mathematical Bridge a kind of + + + align:start position:0% +find this mathematical Bridge a kind of +equivalence between the two approaches + + align:start position:0% +equivalence between the two approaches + + + align:start position:0% +equivalence between the two approaches +Schrodinger I think after that began to + + align:start position:0% +Schrodinger I think after that began to + + + align:start position:0% +Schrodinger I think after that began to +realize there are + + align:start position:0% +realize there are + + + align:start position:0% +realize there are +kind of + + align:start position:0% +kind of + + + align:start position:0% +kind of +conveniences of either approach so it's + + align:start position:0% +conveniences of either approach so it's + + + align:start position:0% +conveniences of either approach so it's +not one versus the other since they + + align:start position:0% +not one versus the other since they + + + align:start position:0% +not one versus the other since they +could be mathematically mapped but as + + align:start position:0% +could be mathematically mapped but as + + + align:start position:0% +could be mathematically mapped but as +each of you probably learned just from + + align:start position:0% +each of you probably learned just from + + + align:start position:0% +each of you probably learned just from +you know problem sets for certain kinds + + align:start position:0% +you know problem sets for certain kinds + + + align:start position:0% +you know problem sets for certain kinds +of questions we might choose to ask for + + align:start position:0% +of questions we might choose to ask for + + + align:start position:0% +of questions we might choose to ask for +certain kinds of calculations one + + align:start position:0% +certain kinds of calculations one + + + align:start position:0% +certain kinds of calculations one +starting approach one coordinate system + + align:start position:0% +starting approach one coordinate system + + + align:start position:0% +starting approach one coordinate system +one + + align:start position:0% +one + + + align:start position:0% +one +um a way of characterizing the balance + + align:start position:0% +um a way of characterizing the balance + + + align:start position:0% +um a way of characterizing the balance +of forces and all that that's often more + + align:start position:0% +of forces and all that that's often more + + + align:start position:0% +of forces and all that that's often more +convenient than others even if in + + align:start position:0% +convenient than others even if in + + + align:start position:0% +convenient than others even if in +principle we could have mapped it into a + + align:start position:0% +principle we could have mapped it into a + + + align:start position:0% +principle we could have mapped it into a +different format that's how people begin + + align:start position:0% +different format that's how people begin + + + align:start position:0% +different format that's how people begin +to talk more and more about the the kind + + align:start position:0% +to talk more and more about the the kind + + + align:start position:0% +to talk more and more about the the kind +of comparing contrast exercise between + + align:start position:0% +of comparing contrast exercise between + + + align:start position:0% +of comparing contrast exercise between +wave mechanics and major mechanics if + + align:start position:0% +wave mechanics and major mechanics if + + + align:start position:0% +wave mechanics and major mechanics if +they are fundamentally mappable then + + align:start position:0% +they are fundamentally mappable then + + + align:start position:0% +they are fundamentally mappable then +sort of use whichever makes most sense + + align:start position:0% +sort of use whichever makes most sense + + + align:start position:0% +sort of use whichever makes most sense +for a given problem I suppose to say + + align:start position:0% +for a given problem I suppose to say + + + align:start position:0% +for a given problem I suppose to say +choose one versus the other so Lucas + + align:start position:0% +choose one versus the other so Lucas + + + align:start position:0% +choose one versus the other so Lucas +hopefully uh tells us that Helga land + + align:start position:0% +hopefully uh tells us that Helga land + + + align:start position:0% +hopefully uh tells us that Helga land +was a site of one of the largest + + align:start position:0% +was a site of one of the largest + + + align:start position:0% +was a site of one of the largest +non-nuclear explosions ever I had no + + align:start position:0% +non-nuclear explosions ever I had no + + + align:start position:0% +non-nuclear explosions ever I had no +idea my goodness thank you I didn't know + + align:start position:0% +idea my goodness thank you I didn't know + + + align:start position:0% +idea my goodness thank you I didn't know +that thank you both to to Alex and Lucas + + align:start position:0% +that thank you both to to Alex and Lucas + + + align:start position:0% +that thank you both to to Alex and Lucas +I've never been to Helga land um I was + + align:start position:0% +I've never been to Helga land um I was + + + align:start position:0% +I've never been to Helga land um I was +hard to travel now to put it mildly that + + align:start position:0% +hard to travel now to put it mildly that + + + align:start position:0% +hard to travel now to put it mildly that +would be an awesome field trip though we + + align:start position:0% +would be an awesome field trip though we + + + align:start position:0% +would be an awesome field trip though we +should we should at least take a a + + align:start position:0% +should we should at least take a a + + + align:start position:0% +should we should at least take a a +virtual field trip we can look into that + + align:start position:0% +virtual field trip we can look into that + + + align:start position:0% +virtual field trip we can look into that +um good so my understanding is Helga + + align:start position:0% +um good so my understanding is Helga + + + align:start position:0% +um good so my understanding is Helga +land it has been contested territory + + align:start position:0% +land it has been contested territory + + + align:start position:0% +land it has been contested territory +again Wikipedia can tell us who it's a + + align:start position:0% +again Wikipedia can tell us who it's a + + + align:start position:0% +again Wikipedia can tell us who it's a +territory of what nation has been an + + align:start position:0% +territory of what nation has been an + + + align:start position:0% +territory of what nation has been an +unstable question Germany Denmark + + align:start position:0% +unstable question Germany Denmark + + + align:start position:0% +unstable question Germany Denmark +probably others it seems to sit in North + + align:start position:0% +probably others it seems to sit in North + + + align:start position:0% +probably others it seems to sit in North +Sea North Sea pretty close to to the + + align:start position:0% +Sea North Sea pretty close to to the + + + align:start position:0% +Sea North Sea pretty close to to the +coasts of both Germany and Denmark so I + + align:start position:0% +coasts of both Germany and Denmark so I + + + align:start position:0% +coasts of both Germany and Denmark so I +knew it's been kind of contestants and I + + align:start position:0% +knew it's been kind of contestants and I + + + align:start position:0% +knew it's been kind of contestants and I +thought it was also a lovely kind of + + align:start position:0% +thought it was also a lovely kind of + + + align:start position:0% +thought it was also a lovely kind of +vacation spot for much of the 19th + + align:start position:0% +vacation spot for much of the 19th + + + align:start position:0% +vacation spot for much of the 19th +century I didn't realize it was um uh + + align:start position:0% +century I didn't realize it was um uh + + + align:start position:0% +century I didn't realize it was um uh +subject to such a bombardment + + align:start position:0% +subject to such a bombardment + + + align:start position:0% +subject to such a bombardment +so that's a preview as you you may have + + align:start position:0% +so that's a preview as you you may have + + + align:start position:0% +so that's a preview as you you may have +guessed we're going to be coming to the + + align:start position:0% +guessed we're going to be coming to the + + + align:start position:0% +guessed we're going to be coming to the +second world war in this class pretty + + align:start position:0% +second world war in this class pretty + + + align:start position:0% +second world war in this class pretty +soon actually so we'll be getting to uh + + align:start position:0% +soon actually so we'll be getting to uh + + + align:start position:0% +soon actually so we'll be getting to uh +to similar kinds of themes actually + + align:start position:0% +to similar kinds of themes actually + + + align:start position:0% +to similar kinds of themes actually +within about two classes so so keep that + + align:start position:0% +within about two classes so so keep that + + + align:start position:0% +within about two classes so so keep that +theme in mind I guess + + align:start position:0% +theme in mind I guess + + + align:start position:0% +theme in mind I guess +any of the questions about Schrodinger + + align:start position:0% +any of the questions about Schrodinger + + + align:start position:0% +any of the questions about Schrodinger +the wave equation superposition + + align:start position:0% +the wave equation superposition + + + align:start position:0% +the wave equation superposition +discrete eigenvalue Spectra + + align:start position:0% +discrete eigenvalue Spectra + + + align:start position:0% +discrete eigenvalue Spectra +they're fun + + align:start position:0% + + + + align:start position:0% + +uh if not then I think I'll I'll press + + align:start position:0% +uh if not then I think I'll I'll press + + + align:start position:0% +uh if not then I think I'll I'll press +on we can we can look at um the next + + align:start position:0% +on we can we can look at um the next + + + align:start position:0% +on we can we can look at um the next +part of class of course obviously please + + align:start position:0% +part of class of course obviously please + + + align:start position:0% +part of class of course obviously please +keep your questions coming if if more + + align:start position:0% +keep your questions coming if if more + + + align:start position:0% +keep your questions coming if if more +questions come up + + align:start position:0% + + + + align:start position:0% + +so let's look now at the second part for + + align:start position:0% +so let's look now at the second part for + + + align:start position:0% +so let's look now at the second part for +today and again here I just reminder + + align:start position:0% +today and again here I just reminder + + + align:start position:0% +today and again here I just reminder +there is the the uh optional lecture + + align:start position:0% +there is the the uh optional lecture + + + align:start position:0% +there is the the uh optional lecture +notes that go into this a little bit + + align:start position:0% +notes that go into this a little bit + + + align:start position:0% +notes that go into this a little bit +more explicitly as well + + align:start position:0% +more explicitly as well + + + align:start position:0% +more explicitly as well +so let's talk about something called the + + align:start position:0% +so let's talk about something called the + + + align:start position:0% +so let's talk about something called the +double slit experiment which again might + + align:start position:0% +double slit experiment which again might + + + align:start position:0% +double slit experiment which again might +be something uh that at least some of + + align:start position:0% +be something uh that at least some of + + + align:start position:0% +be something uh that at least some of +you have heard about before some of you + + align:start position:0% +you have heard about before some of you + + + align:start position:0% +you have heard about before some of you +might have even been able to do a + + align:start position:0% +might have even been able to do a + + + align:start position:0% +might have even been able to do a +version in junior lab for that matter + + align:start position:0% +version in junior lab for that matter + + + align:start position:0% +version in junior lab for that matter +I'm not sure + + align:start position:0% +I'm not sure + + + align:start position:0% +I'm not sure +this is a just a remarkably fruitful + + align:start position:0% +this is a just a remarkably fruitful + + + align:start position:0% +this is a just a remarkably fruitful +um + + align:start position:0% +um + + + align:start position:0% +um +experiment it's sort of the pedagogical + + align:start position:0% +experiment it's sort of the pedagogical + + + align:start position:0% +experiment it's sort of the pedagogical +gift that keeps on giving and I don't + + align:start position:0% +gift that keeps on giving and I don't + + + align:start position:0% +gift that keeps on giving and I don't +it's not just me who think so look at + + align:start position:0% +it's not just me who think so look at + + + align:start position:0% +it's not just me who think so look at +this remarkable series of uh of people + + align:start position:0% +this remarkable series of uh of people + + + align:start position:0% +this remarkable series of uh of people +who have come back time and time again + + align:start position:0% +who have come back time and time again + + + align:start position:0% +who have come back time and time again +to the double slit so Heisenberg's + + align:start position:0% +to the double slit so Heisenberg's + + + align:start position:0% +to the double slit so Heisenberg's +lectured on it as early as 1929 perhaps + + align:start position:0% +lectured on it as early as 1929 perhaps + + + align:start position:0% +lectured on it as early as 1929 perhaps +earlier but that's the first case we + + align:start position:0% +earlier but that's the first case we + + + align:start position:0% +earlier but that's the first case we +know about schroding was lecturing on + + align:start position:0% +know about schroding was lecturing on + + + align:start position:0% +know about schroding was lecturing on +this as early as 1936 and maybe earlier + + align:start position:0% +this as early as 1936 and maybe earlier + + + align:start position:0% +this as early as 1936 and maybe earlier +but we have summer school lecture notes + + align:start position:0% +but we have summer school lecture notes + + + align:start position:0% +but we have summer school lecture notes +from as early as 1936 where Schrodinger + + align:start position:0% +from as early as 1936 where Schrodinger + + + align:start position:0% +from as early as 1936 where Schrodinger +featured it as well + + align:start position:0% +featured it as well + + + align:start position:0% +featured it as well +Niels Bohr featured this very famously + + align:start position:0% +Niels Bohr featured this very famously + + + align:start position:0% +Niels Bohr featured this very famously +it is + + align:start position:0% +it is + + + align:start position:0% +it is +very well-known uh discussion of his + + align:start position:0% +very well-known uh discussion of his + + + align:start position:0% +very well-known uh discussion of his +long debate with Albert Einstein over a + + align:start position:0% +long debate with Albert Einstein over a + + + align:start position:0% +long debate with Albert Einstein over a +quantum theory that was another one of + + align:start position:0% +quantum theory that was another one of + + + align:start position:0% +quantum theory that was another one of +the readings for today was an excerpt a + + align:start position:0% +the readings for today was an excerpt a + + + align:start position:0% +the readings for today was an excerpt a +kind of shortened version of boys very + + align:start position:0% +kind of shortened version of boys very + + + align:start position:0% +kind of shortened version of boys very +famous characterization of his long + + align:start position:0% +famous characterization of his long + + + align:start position:0% +famous characterization of his long +debate with Einstein coming closer to + + align:start position:0% +debate with Einstein coming closer to + + + align:start position:0% +debate with Einstein coming closer to +our own time uh uh in the 1960s Richard + + align:start position:0% +our own time uh uh in the 1960s Richard + + + align:start position:0% +our own time uh uh in the 1960s Richard +Feynman declared that this the double + + align:start position:0% +Feynman declared that this the double + + + align:start position:0% +Feynman declared that this the double +slit has in it the very heart of quantum + + align:start position:0% +slit has in it the very heart of quantum + + + align:start position:0% +slit has in it the very heart of quantum +mechanics he said this is basically all + + align:start position:0% +mechanics he said this is basically all + + + align:start position:0% +mechanics he said this is basically all +you need to know practically about + + align:start position:0% +you need to know practically about + + + align:start position:0% +you need to know practically about +Quantum Theory and even really much more + + align:start position:0% +Quantum Theory and even really much more + + + align:start position:0% +Quantum Theory and even really much more +recently readers of physics World + + align:start position:0% +recently readers of physics World + + + align:start position:0% +recently readers of physics World +magazine which as you may know is the + + align:start position:0% +magazine which as you may know is the + + + align:start position:0% +magazine which as you may know is the +kind of physics today of the of the UK + + align:start position:0% +kind of physics today of the of the UK + + + align:start position:0% +kind of physics today of the of the UK +physics Society they voted this double + + align:start position:0% +physics Society they voted this double + + + align:start position:0% +physics Society they voted this double +slit experiment the single most + + align:start position:0% +slit experiment the single most + + + align:start position:0% +slit experiment the single most +beautiful experiment in the history of + + align:start position:0% +beautiful experiment in the history of + + + align:start position:0% +beautiful experiment in the history of +all of physics not the history of 20th + + align:start position:0% +all of physics not the history of 20th + + + align:start position:0% +all of physics not the history of 20th +century physics since the Earth cooled + + align:start position:0% +century physics since the Earth cooled + + + align:start position:0% +century physics since the Earth cooled +and humans have done experiments to + + align:start position:0% +and humans have done experiments to + + + align:start position:0% +and humans have done experiments to +learn about nature + + align:start position:0% +learn about nature + + + align:start position:0% +learn about nature +readers of physics World magazine + + align:start position:0% +readers of physics World magazine + + + align:start position:0% +readers of physics World magazine +concluded the single most beautiful + + align:start position:0% +concluded the single most beautiful + + + align:start position:0% +concluded the single most beautiful +effort of any kind ever was a double + + align:start position:0% +effort of any kind ever was a double + + + align:start position:0% +effort of any kind ever was a double +slit experiment so let's spend at least + + align:start position:0% +slit experiment so let's spend at least + + + align:start position:0% +slit experiment so let's spend at least +a few minutes giving giving proper uh + + align:start position:0% +a few minutes giving giving proper uh + + + align:start position:0% +a few minutes giving giving proper uh +well-deserved attention to a doubles + + align:start position:0% +well-deserved attention to a doubles + + + align:start position:0% +well-deserved attention to a doubles +thing so here's my very bad cartoon + + align:start position:0% +thing so here's my very bad cartoon + + + align:start position:0% +thing so here's my very bad cartoon +version of a double slit I'm going to + + align:start position:0% +version of a double slit I'm going to + + + align:start position:0% +version of a double slit I'm going to +really follow what Richard feynman's + + align:start position:0% +really follow what Richard feynman's + + + align:start position:0% +really follow what Richard feynman's +approach in what became in the kind of + + align:start position:0% +approach in what became in the kind of + + + align:start position:0% +approach in what became in the kind of +canonical way of of introducing the + + align:start position:0% +canonical way of of introducing the + + + align:start position:0% +canonical way of of introducing the +devil so that I've really lifted much of + + align:start position:0% +devil so that I've really lifted much of + + + align:start position:0% +devil so that I've really lifted much of +this from from finding this very famous + + align:start position:0% +this from from finding this very famous + + + align:start position:0% +this from from finding this very famous +version of this in the final lectures + + align:start position:0% +version of this in the final lectures + + + align:start position:0% +version of this in the final lectures +from the early 60s + + align:start position:0% +from the early 60s + + + align:start position:0% +from the early 60s +uh he would have had better pictures but + + align:start position:0% +uh he would have had better pictures but + + + align:start position:0% +uh he would have had better pictures but +the idea is a piece of it so let's + + align:start position:0% +the idea is a piece of it so let's + + + align:start position:0% +the idea is a piece of it so let's +imagine first the behavior of classical + + align:start position:0% +imagine first the behavior of classical + + + align:start position:0% +imagine first the behavior of classical +particles these could be baseballs or + + align:start position:0% +particles these could be baseballs or + + + align:start position:0% +particles these could be baseballs or +basketballs or or bullets fired from a + + align:start position:0% +basketballs or or bullets fired from a + + + align:start position:0% +basketballs or or bullets fired from a +gun or any kind of traject uh + + align:start position:0% +gun or any kind of traject uh + + + align:start position:0% +gun or any kind of traject uh +um + + align:start position:0% +um + + + align:start position:0% +um +um + + align:start position:0% +um + + + align:start position:0% +um +projectile + + align:start position:0% +projectile + + + align:start position:0% +projectile +so let's imagine we're firing bullets + + align:start position:0% +so let's imagine we're firing bullets + + + align:start position:0% +so let's imagine we're firing bullets +one at a time toward a bulletproof wall + + align:start position:0% +one at a time toward a bulletproof wall + + + align:start position:0% +one at a time toward a bulletproof wall +so this wall here this thick wall is + + align:start position:0% +so this wall here this thick wall is + + + align:start position:0% +so this wall here this thick wall is +meant to be bulletproof sorry and yet + + align:start position:0% +meant to be bulletproof sorry and yet + + + align:start position:0% +meant to be bulletproof sorry and yet +there are two narrow slits in the wall + + align:start position:0% +there are two narrow slits in the wall + + + align:start position:0% +there are two narrow slits in the wall +we'll just label those slits this space + + align:start position:0% +we'll just label those slits this space + + + align:start position:0% +we'll just label those slits this space +here so that a the slit B the slits are + + align:start position:0% +here so that a the slit B the slits are + + + align:start position:0% +here so that a the slit B the slits are +a distance D apart + + align:start position:0% +a distance D apart + + + align:start position:0% +a distance D apart +and then we have some backstop here + + align:start position:0% +and then we have some backstop here + + + align:start position:0% +and then we have some backstop here +where the bullets will kind of Lodge and + + align:start position:0% +where the bullets will kind of Lodge and + + + align:start position:0% +where the bullets will kind of Lodge and +then when it's safe to uh and the guns + + align:start position:0% +then when it's safe to uh and the guns + + + align:start position:0% +then when it's safe to uh and the guns +put away we can go out and count up the + + align:start position:0% +put away we can go out and count up the + + + align:start position:0% +put away we can go out and count up the +number of bullets that landed here + + align:start position:0% +number of bullets that landed here + + + align:start position:0% +number of bullets that landed here +versus here versus here so we're going + + align:start position:0% +versus here versus here so we're going + + + align:start position:0% +versus here versus here so we're going +to ultimately try to add up we're going + + align:start position:0% +to ultimately try to add up we're going + + + align:start position:0% +to ultimately try to add up we're going +to make a kind of histogram and plot the + + align:start position:0% +to make a kind of histogram and plot the + + + align:start position:0% +to make a kind of histogram and plot the +number of bullets per location as we + + align:start position:0% +number of bullets per location as we + + + align:start position:0% +number of bullets per location as we +March up in this direction of the + + align:start position:0% +March up in this direction of the + + + align:start position:0% +March up in this direction of the +backstop so we want to then figure out + + align:start position:0% +backstop so we want to then figure out + + + align:start position:0% +backstop so we want to then figure out +in a sense the probability distribution + + align:start position:0% +in a sense the probability distribution + + + align:start position:0% +in a sense the probability distribution +where our bullets most likely to wind up + + align:start position:0% +where our bullets most likely to wind up + + + align:start position:0% +where our bullets most likely to wind up +on this backdrop when either uh one slot + + align:start position:0% +on this backdrop when either uh one slot + + + align:start position:0% +on this backdrop when either uh one slot +is open the other slot is open or both + + align:start position:0% +is open the other slot is open or both + + + align:start position:0% +is open the other slot is open or both +are open that's our exercise here with + + align:start position:0% +are open that's our exercise here with + + + align:start position:0% +are open that's our exercise here with +classical objects like um baseballs or + + align:start position:0% +classical objects like um baseballs or + + + align:start position:0% +classical objects like um baseballs or +in this case bullets fire from a gun + + align:start position:0% +in this case bullets fire from a gun + + + align:start position:0% +in this case bullets fire from a gun +so let's first imagine that slit a is + + align:start position:0% +so let's first imagine that slit a is + + + align:start position:0% +so let's first imagine that slit a is +open but slit B is closed with some firm + + align:start position:0% +open but slit B is closed with some firm + + + align:start position:0% +open but slit B is closed with some firm +bulletproof you know kind of shielding + + align:start position:0% +bulletproof you know kind of shielding + + + align:start position:0% +bulletproof you know kind of shielding +so then our number of bullets will look + + align:start position:0% +so then our number of bullets will look + + + align:start position:0% +so then our number of bullets will look +like this it's been smoothed out uh + + align:start position:0% +like this it's been smoothed out uh + + + align:start position:0% +like this it's been smoothed out uh +let's say if we shot 10 000 bullets then + + align:start position:0% +let's say if we shot 10 000 bullets then + + + align:start position:0% +let's say if we shot 10 000 bullets then +it would actually be a pretty smooth + + align:start position:0% +it would actually be a pretty smooth + + + align:start position:0% +it would actually be a pretty smooth +curve it would be basically a gaussian + + align:start position:0% +curve it would be basically a gaussian + + + align:start position:0% +curve it would be basically a gaussian +it would look like a kind of um + + align:start position:0% +it would look like a kind of um + + + align:start position:0% +it would look like a kind of um +bell-shaped curve centered around the + + align:start position:0% +bell-shaped curve centered around the + + + align:start position:0% +bell-shaped curve centered around the +open slit most bullets would be found + + align:start position:0% +open slit most bullets would be found + + + align:start position:0% +open slit most bullets would be found +directly behind the open slit but + + align:start position:0% +directly behind the open slit but + + + align:start position:0% +directly behind the open slit but +there'll be some some modest scatter + + align:start position:0% +there'll be some some modest scatter + + + align:start position:0% +there'll be some some modest scatter +some width to the distribution so to + + align:start position:0% +some width to the distribution so to + + + align:start position:0% +some width to the distribution so to +speak + + align:start position:0% +speak + + + align:start position:0% +speak +likewise if we then sealed up slit a + + align:start position:0% +likewise if we then sealed up slit a + + + align:start position:0% +likewise if we then sealed up slit a +with some bulletproof shielding and open + + align:start position:0% +with some bulletproof shielding and open + + + align:start position:0% +with some bulletproof shielding and open +to only slip B and performed and shot + + align:start position:0% +to only slip B and performed and shot + + + align:start position:0% +to only slip B and performed and shot +another 10 000 bullets at it one at a + + align:start position:0% +another 10 000 bullets at it one at a + + + align:start position:0% +another 10 000 bullets at it one at a +time and then did the same counting + + align:start position:0% +time and then did the same counting + + + align:start position:0% +time and then did the same counting +exercise we could make a separate + + align:start position:0% +exercise we could make a separate + + + align:start position:0% +exercise we could make a separate +histogram it looks remarkably similar + + align:start position:0% +histogram it looks remarkably similar + + + align:start position:0% +histogram it looks remarkably similar +not surprising it's such a symmetrical + + align:start position:0% +not surprising it's such a symmetrical + + + align:start position:0% +not surprising it's such a symmetrical +problem + + align:start position:0% +problem + + + align:start position:0% +problem +so if only slit B is open then the vast + + align:start position:0% +so if only slit B is open then the vast + + + align:start position:0% +so if only slit B is open then the vast +majority of bullets are found directly + + align:start position:0% +majority of bullets are found directly + + + align:start position:0% +majority of bullets are found directly +behind that open slit and there'll be + + align:start position:0% +behind that open slit and there'll be + + + align:start position:0% +behind that open slit and there'll be +some kind of bell-shaped curve it + + align:start position:0% +some kind of bell-shaped curve it + + + align:start position:0% +some kind of bell-shaped curve it +basically kind of gaussian distribution + + align:start position:0% +basically kind of gaussian distribution + + + align:start position:0% +basically kind of gaussian distribution +on either side there'll be some modest + + align:start position:0% +on either side there'll be some modest + + + align:start position:0% +on either side there'll be some modest +scatter and then if we then open both + + align:start position:0% +scatter and then if we then open both + + + align:start position:0% +scatter and then if we then open both +slits fire another ten thousand bullets + + align:start position:0% +slits fire another ten thousand bullets + + + align:start position:0% +slits fire another ten thousand bullets +at the at the bulletproof wall with both + + align:start position:0% +at the at the bulletproof wall with both + + + align:start position:0% +at the at the bulletproof wall with both +slits A and B open do the same exercise + + align:start position:0% +slits A and B open do the same exercise + + + align:start position:0% +slits A and B open do the same exercise +and make our histogram the resulting + + align:start position:0% +and make our histogram the resulting + + + align:start position:0% +and make our histogram the resulting +distribution is just the sum of the + + align:start position:0% +distribution is just the sum of the + + + align:start position:0% +distribution is just the sum of the +previous two so now there are a fair + + align:start position:0% +previous two so now there are a fair + + + align:start position:0% +previous two so now there are a fair +number of bullets that wind up in the + + align:start position:0% +number of bullets that wind up in the + + + align:start position:0% +number of bullets that wind up in the +middle because some are coming from the + + align:start position:0% +middle because some are coming from the + + + align:start position:0% +middle because some are coming from the +tail of this distribution some are + + align:start position:0% +tail of this distribution some are + + + align:start position:0% +tail of this distribution some are +coming from the tail of this + + align:start position:0% +coming from the tail of this + + + align:start position:0% +coming from the tail of this +distribution and so some of them wind up + + align:start position:0% +distribution and so some of them wind up + + + align:start position:0% +distribution and so some of them wind up +in the middle + + align:start position:0% +in the middle + + + align:start position:0% +in the middle +it's the sum of those two but + + align:start position:0% +it's the sum of those two but + + + align:start position:0% +it's the sum of those two but +nonetheless the distribution is clearly + + align:start position:0% +nonetheless the distribution is clearly + + + align:start position:0% +nonetheless the distribution is clearly +still peaked in the positions directly + + align:start position:0% +still peaked in the positions directly + + + align:start position:0% +still peaked in the positions directly +behind the two open slits so we have the + + align:start position:0% +behind the two open slits so we have the + + + align:start position:0% +behind the two open slits so we have the +resulting probability distribution the + + align:start position:0% +resulting probability distribution the + + + align:start position:0% +resulting probability distribution the +histogram when we add up when both sits + + align:start position:0% +histogram when we add up when both sits + + + align:start position:0% +histogram when we add up when both sits +are open really is just the sum of those + + align:start position:0% +are open really is just the sum of those + + + align:start position:0% +are open really is just the sum of those +two separate ones and so for classical + + align:start position:0% +two separate ones and so for classical + + + align:start position:0% +two separate ones and so for classical +particles these probability + + align:start position:0% +particles these probability + + + align:start position:0% +particles these probability +distributions are of independent events + + align:start position:0% +distributions are of independent events + + + align:start position:0% +distributions are of independent events +and therefore the probabilities in this + + align:start position:0% +and therefore the probabilities in this + + + align:start position:0% +and therefore the probabilities in this +case simply add we can get the + + align:start position:0% +case simply add we can get the + + + align:start position:0% +case simply add we can get the +probability distribution for the for the + + align:start position:0% +probability distribution for the for the + + + align:start position:0% +probability distribution for the for the +combined Series so let's A and B open + + align:start position:0% +combined Series so let's A and B open + + + align:start position:0% +combined Series so let's A and B open +simply by adding two independent + + align:start position:0% +simply by adding two independent + + + align:start position:0% +simply by adding two independent +possibilities each bullet either went + + align:start position:0% +possibilities each bullet either went + + + align:start position:0% +possibilities each bullet either went +through slit a in which case it followed + + align:start position:0% +through slit a in which case it followed + + + align:start position:0% +through slit a in which case it followed +this distribution or each bullet or an + + align:start position:0% +this distribution or each bullet or an + + + align:start position:0% +this distribution or each bullet or an +individual bullets went through slit B + + align:start position:0% +individual bullets went through slit B + + + align:start position:0% +individual bullets went through slit B +add up those two options here's our + + align:start position:0% +add up those two options here's our + + + align:start position:0% +add up those two options here's our +resulting distribution not too + + align:start position:0% +resulting distribution not too + + + align:start position:0% +resulting distribution not too +surprising + + align:start position:0% +surprising + + + align:start position:0% +surprising +now let's try a second version with + + align:start position:0% +now let's try a second version with + + + align:start position:0% +now let's try a second version with +waves and this could be macroscopic + + align:start position:0% +waves and this could be macroscopic + + + align:start position:0% +waves and this could be macroscopic +waves for example ocean waves I in my + + align:start position:0% +waves for example ocean waves I in my + + + align:start position:0% +waves for example ocean waves I in my +little write-up I talk about you know + + align:start position:0% +little write-up I talk about you know + + + align:start position:0% +little write-up I talk about you know +doing this near the coast of Australia + + align:start position:0% +doing this near the coast of Australia + + + align:start position:0% +doing this near the coast of Australia +with waves approaching the Great Barrier + + align:start position:0% +with waves approaching the Great Barrier + + + align:start position:0% +with waves approaching the Great Barrier +Reef but it could be even in an + + align:start position:0% +Reef but it could be even in an + + + align:start position:0% +Reef but it could be even in an +artificial wave pool with with some + + align:start position:0% +artificial wave pool with with some + + + align:start position:0% +artificial wave pool with with some +barrier + + align:start position:0% +barrier + + + align:start position:0% +barrier +so now we have some some Reef or some + + align:start position:0% +so now we have some some Reef or some + + + align:start position:0% +so now we have some some Reef or some +some uh structure that can block waves + + align:start position:0% +some uh structure that can block waves + + + align:start position:0% +some uh structure that can block waves +that are coming from further away + + align:start position:0% +that are coming from further away + + + align:start position:0% +that are coming from further away +they're approaching here's the shore and + + align:start position:0% +they're approaching here's the shore and + + + align:start position:0% +they're approaching here's the shore and +we have some barrier that will block + + align:start position:0% +we have some barrier that will block + + + align:start position:0% +we have some barrier that will block +waves from passing through here but the + + align:start position:0% +waves from passing through here but the + + + align:start position:0% +waves from passing through here but the +barrier has these two narrow slits which + + align:start position:0% +barrier has these two narrow slits which + + + align:start position:0% +barrier has these two narrow slits which +again we can label A and B and there is + + align:start position:0% +again we can label A and B and there is + + + align:start position:0% +again we can label A and B and there is +distance D apart so now what we want to + + align:start position:0% +distance D apart so now what we want to + + + align:start position:0% +distance D apart so now what we want to +do is measure the the the intensity of + + align:start position:0% +do is measure the the the intensity of + + + align:start position:0% +do is measure the the the intensity of +the Waves uh that lap up on shore + + align:start position:0% +the Waves uh that lap up on shore + + + align:start position:0% +the Waves uh that lap up on shore +clearly some water gets through slits A + + align:start position:0% +clearly some water gets through slits A + + + align:start position:0% +clearly some water gets through slits A +and B so what's the pattern of waves + + align:start position:0% +and B so what's the pattern of waves + + + align:start position:0% +and B so what's the pattern of waves +that we find on the shoreline and how + + align:start position:0% +that we find on the shoreline and how + + + align:start position:0% +that we find on the shoreline and how +does the intensity of that wave vary as + + align:start position:0% +does the intensity of that wave vary as + + + align:start position:0% +does the intensity of that wave vary as +we measure uh as we March along in + + align:start position:0% +we measure uh as we March along in + + + align:start position:0% +we measure uh as we March along in +location and again we'll project the the + + align:start position:0% +location and again we'll project the the + + + align:start position:0% +location and again we'll project the the +positions of slits uh A and B on the + + align:start position:0% +positions of slits uh A and B on the + + + align:start position:0% +positions of slits uh A and B on the +shore and that's about the varying + + align:start position:0% +shore and that's about the varying + + + align:start position:0% +shore and that's about the varying +intensity of the resulting wave as a + + align:start position:0% +intensity of the resulting wave as a + + + align:start position:0% +intensity of the resulting wave as a +function of distance or location + + align:start position:0% +function of distance or location + + + align:start position:0% +function of distance or location +so once again let's start with only one + + align:start position:0% +so once again let's start with only one + + + align:start position:0% +so once again let's start with only one +of those slits open so we're going to + + align:start position:0% +of those slits open so we're going to + + + align:start position:0% +of those slits open so we're going to +close slit B with some kind of dam we're + + align:start position:0% +close slit B with some kind of dam we're + + + align:start position:0% +close slit B with some kind of dam we're +going to block one of those slits so + + align:start position:0% +going to block one of those slits so + + + align:start position:0% +going to block one of those slits so +water can only get through that one uh + + align:start position:0% +water can only get through that one uh + + + align:start position:0% +water can only get through that one uh +narrow slit a and therefore we'll have a + + align:start position:0% +narrow slit a and therefore we'll have a + + + align:start position:0% +narrow slit a and therefore we'll have a +clearly peaked distribution the wave + + align:start position:0% +clearly peaked distribution the wave + + + align:start position:0% +clearly peaked distribution the wave +that results that we find unsure is + + align:start position:0% +that results that we find unsure is + + + align:start position:0% +that results that we find unsure is +virtually uh zero far away from that + + align:start position:0% +virtually uh zero far away from that + + + align:start position:0% +virtually uh zero far away from that +sort of location of slit a the + + align:start position:0% +sort of location of slit a the + + + align:start position:0% +sort of location of slit a the +projection onto the shore of the open + + align:start position:0% +projection onto the shore of the open + + + align:start position:0% +projection onto the shore of the open +slit It's very clearly peaked right + + align:start position:0% +slit It's very clearly peaked right + + + align:start position:0% +slit It's very clearly peaked right +directly behind the open slit we in fact + + align:start position:0% +directly behind the open slit we in fact + + + align:start position:0% +directly behind the open slit we in fact +we can characterize the intensity of the + + align:start position:0% +we can characterize the intensity of the + + + align:start position:0% +we can characterize the intensity of the +wave as the square of some amplitude + + align:start position:0% +wave as the square of some amplitude + + + align:start position:0% +wave as the square of some amplitude +it's a wave it has some amplitude and + + align:start position:0% +it's a wave it has some amplitude and + + + align:start position:0% +it's a wave it has some amplitude and +some phase and the amp and the intensity + + align:start position:0% +some phase and the amp and the intensity + + + align:start position:0% +some phase and the amp and the intensity +goes clearly as the square of this of + + align:start position:0% +goes clearly as the square of this of + + + align:start position:0% +goes clearly as the square of this of +this height or this of this amplitude + + align:start position:0% +this height or this of this amplitude + + + align:start position:0% +this height or this of this amplitude +and it's basically is very clearly + + align:start position:0% +and it's basically is very clearly + + + align:start position:0% +and it's basically is very clearly +dramatically peaked behind the open slit + + align:start position:0% +dramatically peaked behind the open slit + + + align:start position:0% +dramatically peaked behind the open slit +now we sort of place the dam in front of + + align:start position:0% +now we sort of place the dam in front of + + + align:start position:0% +now we sort of place the dam in front of +slit a open slit B same kind of story + + align:start position:0% +slit a open slit B same kind of story + + + align:start position:0% +slit a open slit B same kind of story +but as many of you probably know once we + + align:start position:0% +but as many of you probably know once we + + + align:start position:0% +but as many of you probably know once we +open both slits A and B we get a totally + + align:start position:0% +open both slits A and B we get a totally + + + align:start position:0% +open both slits A and B we get a totally +different story now we get one of these + + align:start position:0% +different story now we get one of these + + + align:start position:0% +different story now we get one of these +kind of characteristic interference + + align:start position:0% +kind of characteristic interference + + + align:start position:0% +kind of characteristic interference +patterns on the shore not merely the sum + + align:start position:0% +patterns on the shore not merely the sum + + + align:start position:0% +patterns on the shore not merely the sum +of these two distributions together and + + align:start position:0% +of these two distributions together and + + + align:start position:0% +of these two distributions together and +if we do a little more work we can + + align:start position:0% +if we do a little more work we can + + + align:start position:0% +if we do a little more work we can +realize we can still characterize the + + align:start position:0% +realize we can still characterize the + + + align:start position:0% +realize we can still characterize the +resulting intensity by summing something + + align:start position:0% +resulting intensity by summing something + + + align:start position:0% +resulting intensity by summing something +together not by summing the two + + align:start position:0% +together not by summing the two + + + align:start position:0% +together not by summing the two +intensities actually by summing the two + + align:start position:0% +intensities actually by summing the two + + + align:start position:0% +intensities actually by summing the two +amplitudes first and then squaring that + + align:start position:0% +amplitudes first and then squaring that + + + align:start position:0% +amplitudes first and then squaring that +and that's what allows for these + + align:start position:0% +and that's what allows for these + + + align:start position:0% +and that's what allows for these +interference patterns much like we saw + + align:start position:0% +interference patterns much like we saw + + + align:start position:0% +interference patterns much like we saw +with the standing waves earlier in + + align:start position:0% +with the standing waves earlier in + + + align:start position:0% +with the standing waves earlier in +regions where uh two crests happen to + + align:start position:0% +regions where uh two crests happen to + + + align:start position:0% +regions where uh two crests happen to +align we'll get a sharp constructive + + align:start position:0% +align we'll get a sharp constructive + + + align:start position:0% +align we'll get a sharp constructive +interference a heightened peak in + + align:start position:0% +interference a heightened peak in + + + align:start position:0% +interference a heightened peak in +regions where there might have been one + + align:start position:0% +regions where there might have been one + + + align:start position:0% +regions where there might have been one +large Peak but a very small uh um trough + + align:start position:0% +large Peak but a very small uh um trough + + + align:start position:0% +large Peak but a very small uh um trough +on the other side will get a destructive + + align:start position:0% +on the other side will get a destructive + + + align:start position:0% +on the other side will get a destructive +interference so in fact when we when we + + align:start position:0% +interference so in fact when we when we + + + align:start position:0% +interference so in fact when we when we +add the amplitudes and then Square the + + align:start position:0% +add the amplitudes and then Square the + + + align:start position:0% +add the amplitudes and then Square the +resulting intensity looks nothing like + + align:start position:0% +resulting intensity looks nothing like + + + align:start position:0% +resulting intensity looks nothing like +the sum of the two intensities because + + align:start position:0% +the sum of the two intensities because + + + align:start position:0% +the sum of the two intensities because +that would Overlook that would discount + + align:start position:0% +that would Overlook that would discount + + + align:start position:0% +that would Overlook that would discount +all these uh ways that the waves can + + align:start position:0% +all these uh ways that the waves can + + + align:start position:0% +all these uh ways that the waves can +actually interfere with each other and + + align:start position:0% +actually interfere with each other and + + + align:start position:0% +actually interfere with each other and +one indication of that + + align:start position:0% +one indication of that + + + align:start position:0% +one indication of that +is this characteristic feature of the + + align:start position:0% +is this characteristic feature of the + + + align:start position:0% +is this characteristic feature of the +interference pattern the point on the + + align:start position:0% +interference pattern the point on the + + + align:start position:0% +interference pattern the point on the +shore with the largest intensity is a + + align:start position:0% +shore with the largest intensity is a + + + align:start position:0% +shore with the largest intensity is a +point between either two slits whereas + + align:start position:0% +point between either two slits whereas + + + align:start position:0% +point between either two slits whereas +when either is open alone that's the + + align:start position:0% +when either is open alone that's the + + + align:start position:0% +when either is open alone that's the +point of actually virtually Vanishing + + align:start position:0% +point of actually virtually Vanishing + + + align:start position:0% +point of actually virtually Vanishing +intensity so the greatest intensity is + + align:start position:0% +intensity so the greatest intensity is + + + align:start position:0% +intensity so the greatest intensity is +at a spot where neither a scenario on + + align:start position:0% +at a spot where neither a scenario on + + + align:start position:0% +at a spot where neither a scenario on +its own had much power at all and so + + align:start position:0% +its own had much power at all and so + + + align:start position:0% +its own had much power at all and so +again this is a characteristic of + + align:start position:0% +again this is a characteristic of + + + align:start position:0% +again this is a characteristic of +classical wave behavior that the + + align:start position:0% +classical wave behavior that the + + + align:start position:0% +classical wave behavior that the +intensity goes as the square of the sum + + align:start position:0% +intensity goes as the square of the sum + + + align:start position:0% +intensity goes as the square of the sum +not the sum and the squares and since + + align:start position:0% +not the sum and the squares and since + + + align:start position:0% +not the sum and the squares and since +the amplitudes can be both positive and + + align:start position:0% +the amplitudes can be both positive and + + + align:start position:0% +the amplitudes can be both positive and +negative it can even they can even be + + align:start position:0% +negative it can even they can even be + + + align:start position:0% +negative it can even they can even be +complex numbers there could be all kinds + + align:start position:0% +complex numbers there could be all kinds + + + align:start position:0% +complex numbers there could be all kinds +of situations in which the sum + + align:start position:0% +of situations in which the sum + + + align:start position:0% +of situations in which the sum +uh is uh this is in which the square of + + align:start position:0% +uh is uh this is in which the square of + + + align:start position:0% +uh is uh this is in which the square of +the sum is quite different than the sum + + align:start position:0% +the sum is quite different than the sum + + + align:start position:0% +the sum is quite different than the sum +of the squares + + align:start position:0% +of the squares + + + align:start position:0% +of the squares +characteristic wave-like uh interference + + align:start position:0% +characteristic wave-like uh interference + + + align:start position:0% +characteristic wave-like uh interference +pattern again probably pretty familiar + + align:start position:0% +pattern again probably pretty familiar + + + align:start position:0% +pattern again probably pretty familiar +so now what happens when we now move to + + align:start position:0% +so now what happens when we now move to + + + align:start position:0% +so now what happens when we now move to +the quantum Realm + + align:start position:0% +the quantum Realm + + + align:start position:0% +the quantum Realm +now let's imagine some cathode ray like + + align:start position:0% +now let's imagine some cathode ray like + + + align:start position:0% +now let's imagine some cathode ray like +JJ Thompson had or of the sort that um + + align:start position:0% +JJ Thompson had or of the sort that um + + + align:start position:0% +JJ Thompson had or of the sort that um +that was by this point quite familiar + + align:start position:0% +that was by this point quite familiar + + + align:start position:0% +that was by this point quite familiar +even by the 1920s things like what um uh + + align:start position:0% +even by the 1920s things like what um uh + + + align:start position:0% +even by the 1920s things like what um uh +girmer and Davison used in 1927 to think + + align:start position:0% +girmer and Davison used in 1927 to think + + + align:start position:0% +girmer and Davison used in 1927 to think +about uh Del boring waves this was + + align:start position:0% +about uh Del boring waves this was + + + align:start position:0% +about uh Del boring waves this was +already literally a feasible experiment + + align:start position:0% +already literally a feasible experiment + + + align:start position:0% +already literally a feasible experiment +as early as the mid-1920s people tried + + align:start position:0% +as early as the mid-1920s people tried + + + align:start position:0% +as early as the mid-1920s people tried +to do it + + align:start position:0% +to do it + + + align:start position:0% +to do it +so let's imagine shooting out single + + align:start position:0% +so let's imagine shooting out single + + + align:start position:0% +so let's imagine shooting out single +electrons one at a time from some Source + + align:start position:0% +electrons one at a time from some Source + + + align:start position:0% +electrons one at a time from some Source +some cathode ray let's say some electron + + align:start position:0% +some cathode ray let's say some electron + + + align:start position:0% +some cathode ray let's say some electron +gun we're going to send one electron at + + align:start position:0% +gun we're going to send one electron at + + + align:start position:0% +gun we're going to send one electron at +a time we're not going to have a + + align:start position:0% +a time we're not going to have a + + + align:start position:0% +a time we're not going to have a +continuous sprayer then we'll spend send + + align:start position:0% +continuous sprayer then we'll spend send + + + align:start position:0% +continuous sprayer then we'll spend send +one shut down the device let it cool go + + align:start position:0% +one shut down the device let it cool go + + + align:start position:0% +one shut down the device let it cool go +out for a coffee come back an hour later + + align:start position:0% +out for a coffee come back an hour later + + + align:start position:0% +out for a coffee come back an hour later +send out one more electron we can really + + align:start position:0% +send out one more electron we can really + + + align:start position:0% +send out one more electron we can really +take our time + + align:start position:0% +take our time + + + align:start position:0% +take our time +so at any given moment there's only one + + align:start position:0% +so at any given moment there's only one + + + align:start position:0% +so at any given moment there's only one +electron in in play in the device + + align:start position:0% +electron in in play in the device + + + align:start position:0% +electron in in play in the device +we're going to aim those 100 time + + align:start position:0% +we're going to aim those 100 time + + + align:start position:0% +we're going to aim those 100 time +electrons at a device this is by the way + + align:start position:0% +electrons at a device this is by the way + + + align:start position:0% +electrons at a device this is by the way +taken this illustration is taken from + + align:start position:0% +taken this illustration is taken from + + + align:start position:0% +taken this illustration is taken from +Bohr's essay about his debates with + + align:start position:0% +Bohr's essay about his debates with + + + align:start position:0% +Bohr's essay about his debates with +Einstein you hopefully recognize it from + + align:start position:0% +Einstein you hopefully recognize it from + + + align:start position:0% +Einstein you hopefully recognize it from +your reader so we're going to send these + + align:start position:0% +your reader so we're going to send these + + + align:start position:0% +your reader so we're going to send these +electrons one at a time toward a device + + align:start position:0% +electrons one at a time toward a device + + + align:start position:0% +electrons one at a time toward a device +that has two slits the electrons will be + + align:start position:0% +that has two slits the electrons will be + + + align:start position:0% +that has two slits the electrons will be +blocked if they hit anywhere here but + + align:start position:0% +blocked if they hit anywhere here but + + + align:start position:0% +blocked if they hit anywhere here but +they can get through either this slit or + + align:start position:0% +they can get through either this slit or + + + align:start position:0% +they can get through either this slit or +that slit and we have the opportunity to + + align:start position:0% +that slit and we have the opportunity to + + + align:start position:0% +that slit and we have the opportunity to +open or close each lit independently + + align:start position:0% +open or close each lit independently + + + align:start position:0% +open or close each lit independently +and then behind the the wall with two + + align:start position:0% +and then behind the the wall with two + + + align:start position:0% +and then behind the the wall with two +slits we have an array of very closely + + align:start position:0% +slits we have an array of very closely + + + align:start position:0% +slits we have an array of very closely +spaced detectors electron detectors uh + + align:start position:0% +spaced detectors electron detectors uh + + + align:start position:0% +spaced detectors electron detectors uh +and so we can measure with very good + + align:start position:0% +and so we can measure with very good + + + align:start position:0% +and so we can measure with very good +resolution the where electrons are + + align:start position:0% +resolution the where electrons are + + + align:start position:0% +resolution the where electrons are +detected as a function of position along + + align:start position:0% +detected as a function of position along + + + align:start position:0% +detected as a function of position along +this kind of backstop this array of + + align:start position:0% +this kind of backstop this array of + + + align:start position:0% +this kind of backstop this array of +detectors + + align:start position:0% +detectors + + + align:start position:0% +detectors +we also can arrange things so the + + align:start position:0% +we also can arrange things so the + + + align:start position:0% +we also can arrange things so the +distance between the two slits the + + align:start position:0% +distance between the two slits the + + + align:start position:0% +distance between the two slits the +distance Little D uh is say 10 000 times + + align:start position:0% +distance Little D uh is say 10 000 times + + + align:start position:0% +distance Little D uh is say 10 000 times +larger than the uh characteristic wave + + align:start position:0% +larger than the uh characteristic wave + + + align:start position:0% +larger than the uh characteristic wave +in a scale the devoid wavelength of + + align:start position:0% +in a scale the devoid wavelength of + + + align:start position:0% +in a scale the devoid wavelength of +those electrons so the electron if it's + + align:start position:0% +those electrons so the electron if it's + + + align:start position:0% +those electrons so the electron if it's +approaching uh if it's anywhere near + + align:start position:0% +approaching uh if it's anywhere near + + + align:start position:0% +approaching uh if it's anywhere near +this lit it should be ten thousand sort + + align:start position:0% +this lit it should be ten thousand sort + + + align:start position:0% +this lit it should be ten thousand sort +of electron distances away from that + + align:start position:0% +of electron distances away from that + + + align:start position:0% +of electron distances away from that +slit and vice versa it somehow it should + + align:start position:0% +slit and vice versa it somehow it should + + + align:start position:0% +slit and vice versa it somehow it should +have a kind of localized Behavior as it + + align:start position:0% +have a kind of localized Behavior as it + + + align:start position:0% +have a kind of localized Behavior as it +encounters the slits moreover each of + + align:start position:0% +encounters the slits moreover each of + + + align:start position:0% +encounters the slits moreover each of +the detectors is going to detect the + + align:start position:0% +the detectors is going to detect the + + + align:start position:0% +the detectors is going to detect the +location of electron when they're very + + align:start position:0% +location of electron when they're very + + + align:start position:0% +location of electron when they're very +very small uh region of space so we're + + align:start position:0% +very small uh region of space so we're + + + align:start position:0% +very small uh region of space so we're +not going to expect to find a kind of + + align:start position:0% +not going to expect to find a kind of + + + align:start position:0% +not going to expect to find a kind of +splayed out wave of electrons each one + + align:start position:0% +splayed out wave of electrons each one + + + align:start position:0% +splayed out wave of electrons each one +is detected as a point-like discrete uh + + align:start position:0% +is detected as a point-like discrete uh + + + align:start position:0% +is detected as a point-like discrete uh +particulate detection because we've + + align:start position:0% +particulate detection because we've + + + align:start position:0% +particulate detection because we've +these very high resolution detectors in + + align:start position:0% +these very high resolution detectors in + + + align:start position:0% +these very high resolution detectors in +the back + + align:start position:0% +the back + + + align:start position:0% +the back +so we're going to release one electron + + align:start position:0% +so we're going to release one electron + + + align:start position:0% +so we're going to release one electron +at a time wait one hour between and do + + align:start position:0% +at a time wait one hour between and do + + + align:start position:0% +at a time wait one hour between and do +that ten thousand times which as I like + + align:start position:0% +that ten thousand times which as I like + + + align:start position:0% +that ten thousand times which as I like +to say is why we actually have graduate + + align:start position:0% +to say is why we actually have graduate + + + align:start position:0% +to say is why we actually have graduate +students I mean who's going to patients + + align:start position:0% +students I mean who's going to patients + + + align:start position:0% +students I mean who's going to patients +for that with many thanks to our + + align:start position:0% +for that with many thanks to our + + + align:start position:0% +for that with many thanks to our +teaching assistants so this is you know + + align:start position:0% +teaching assistants so this is you know + + + align:start position:0% +teaching assistants so this is you know +going to take months + + align:start position:0% +going to take months + + + align:start position:0% +going to take months +but we care about the nature of the + + align:start position:0% +but we care about the nature of the + + + align:start position:0% +but we care about the nature of the +universe uh and so we're going to just + + align:start position:0% +universe uh and so we're going to just + + + align:start position:0% +universe uh and so we're going to just +go plow through and do this now we're + + align:start position:0% +go plow through and do this now we're + + + align:start position:0% +go plow through and do this now we're +going to do the same kind of accounting + + align:start position:0% +going to do the same kind of accounting + + + align:start position:0% +going to do the same kind of accounting +exercise as we've done with both the um + + align:start position:0% +exercise as we've done with both the um + + + align:start position:0% +exercise as we've done with both the um +classical particles of the classical + + align:start position:0% +classical particles of the classical + + + align:start position:0% +classical particles of the classical +waves we're going to make a kind of + + align:start position:0% +waves we're going to make a kind of + + + align:start position:0% +waves we're going to make a kind of +histogram of the number of electrons + + align:start position:0% +histogram of the number of electrons + + + align:start position:0% +histogram of the number of electrons +that are found in each of these uh sort + + align:start position:0% +that are found in each of these uh sort + + + align:start position:0% +that are found in each of these uh sort +of bins each of these detector bins as a + + align:start position:0% +of bins each of these detector bins as a + + + align:start position:0% +of bins each of these detector bins as a +function of location + + align:start position:0% +function of location + + + align:start position:0% +function of location +so once again we'll start by keeping one + + align:start position:0% +so once again we'll start by keeping one + + + align:start position:0% +so once again we'll start by keeping one +slit closed so the electrons can only + + align:start position:0% +slit closed so the electrons can only + + + align:start position:0% +slit closed so the electrons can only +pass through the other slit so if only + + align:start position:0% +pass through the other slit so if only + + + align:start position:0% +pass through the other slit so if only +slit a is open we get this very strongly + + align:start position:0% +slit a is open we get this very strongly + + + align:start position:0% +slit a is open we get this very strongly +peaked distribution directly behind the + + align:start position:0% +peaked distribution directly behind the + + + align:start position:0% +peaked distribution directly behind the +Oakley slit just like with the bullets + + align:start position:0% +Oakley slit just like with the bullets + + + align:start position:0% +Oakley slit just like with the bullets +if slit a is closed but only slit B is + + align:start position:0% +if slit a is closed but only slit B is + + + align:start position:0% +if slit a is closed but only slit B is +open again it very strongly Peaks + + align:start position:0% +open again it very strongly Peaks + + + align:start position:0% +open again it very strongly Peaks +distribution and so it looks a lot like + + align:start position:0% +distribution and so it looks a lot like + + + align:start position:0% +distribution and so it looks a lot like +the classical particles in fact if + + align:start position:0% +the classical particles in fact if + + + align:start position:0% +the classical particles in fact if +you've taken Junior lab you probably + + align:start position:0% +you've taken Junior lab you probably + + + align:start position:0% +you've taken Junior lab you probably +would learn to say those little Wiggles + + align:start position:0% +would learn to say those little Wiggles + + + align:start position:0% +would learn to say those little Wiggles +are clearly instrumental error that + + align:start position:0% +are clearly instrumental error that + + + align:start position:0% +are clearly instrumental error that +statistical uh uh insignificance they + + align:start position:0% +statistical uh uh insignificance they + + + align:start position:0% +statistical uh uh insignificance they +never rise above about one percent of + + align:start position:0% +never rise above about one percent of + + + align:start position:0% +never rise above about one percent of +the central Peak it really looks like + + align:start position:0% +the central Peak it really looks like + + + align:start position:0% +the central Peak it really looks like +electrons behaving like bullets they're + + align:start position:0% +electrons behaving like bullets they're + + + align:start position:0% +electrons behaving like bullets they're +each emitted like a tiny little discrete + + align:start position:0% +each emitted like a tiny little discrete + + + align:start position:0% +each emitted like a tiny little discrete +particle they're encountering one slit + + align:start position:0% +particle they're encountering one slit + + + align:start position:0% +particle they're encountering one slit +or the other because we've arranged the + + align:start position:0% +or the other because we've arranged the + + + align:start position:0% +or the other because we've arranged the +distance to be so extreme they're all + + align:start position:0% +distance to be so extreme they're all + + + align:start position:0% +distance to be so extreme they're all +being detected as one little blip on + + align:start position:0% +being detected as one little blip on + + + align:start position:0% +being detected as one little blip on +that detector screen they look like + + align:start position:0% +that detector screen they look like + + + align:start position:0% +that detector screen they look like +little baseballs or bullets + + align:start position:0% +little baseballs or bullets + + + align:start position:0% +little baseballs or bullets +and yet + + align:start position:0% +and yet + + + align:start position:0% +and yet +when we then look at the pattern when + + align:start position:0% +when we then look at the pattern when + + + align:start position:0% +when we then look at the pattern when +both slits are open but only one + + align:start position:0% +both slits are open but only one + + + align:start position:0% +both slits are open but only one +electron went through at a time + + align:start position:0% +electron went through at a time + + + align:start position:0% +electron went through at a time +we get right back to this very familiar + + align:start position:0% +we get right back to this very familiar + + + align:start position:0% +we get right back to this very familiar +wave pattern this chest + + align:start position:0% +wave pattern this chest + + + align:start position:0% +wave pattern this chest +how this can happen has kept people up + + align:start position:0% +how this can happen has kept people up + + + align:start position:0% +how this can happen has kept people up +at night for now very nearly 100 years + + align:start position:0% +at night for now very nearly 100 years + + + align:start position:0% +at night for now very nearly 100 years +and I hope we're not too blase about it + + align:start position:0% +and I hope we're not too blase about it + + + align:start position:0% +and I hope we're not too blase about it +even today + + align:start position:0% +even today + + + align:start position:0% +even today +that looks like particles when only one + + align:start position:0% +that looks like particles when only one + + + align:start position:0% +that looks like particles when only one +slits open it looks like waves when both + + align:start position:0% +slits open it looks like waves when both + + + align:start position:0% +slits open it looks like waves when both +sets are open and yet and yet we've been + + align:start position:0% +sets are open and yet and yet we've been + + + align:start position:0% +sets are open and yet and yet we've been +super careful to only send one electron + + align:start position:0% +super careful to only send one electron + + + align:start position:0% +super careful to only send one electron +through at a time unlike a water wave is + + align:start position:0% +through at a time unlike a water wave is + + + align:start position:0% +through at a time unlike a water wave is +clearly an extended continuous object + + align:start position:0% +clearly an extended continuous object + + + align:start position:0% +clearly an extended continuous object +clearly the wave can interfere with + + align:start position:0% +clearly the wave can interfere with + + + align:start position:0% +clearly the wave can interfere with +itself it is literally an extended + + align:start position:0% +itself it is literally an extended + + + align:start position:0% +itself it is literally an extended +object which has many moving Parts these + + align:start position:0% +object which has many moving Parts these + + + align:start position:0% +object which has many moving Parts these +electrons are tiny little pellets we we + + align:start position:0% +electrons are tiny little pellets we we + + + align:start position:0% +electrons are tiny little pellets we we +can we we emit them as little discrete + + align:start position:0% +can we we emit them as little discrete + + + align:start position:0% +can we we emit them as little discrete +bundles + + align:start position:0% +bundles + + + align:start position:0% +bundles +uh we only have one in play at a times + + align:start position:0% +uh we only have one in play at a times + + + align:start position:0% +uh we only have one in play at a times +there's not like two electrons could + + align:start position:0% +there's not like two electrons could + + + align:start position:0% +there's not like two electrons could +have influenced each other by repelling + + align:start position:0% +have influenced each other by repelling + + + align:start position:0% +have influenced each other by repelling +each other and made some kind of + + align:start position:0% +each other and made some kind of + + + align:start position:0% +each other and made some kind of +characteristic uh pattern because they + + align:start position:0% +characteristic uh pattern because they + + + align:start position:0% +characteristic uh pattern because they +were interacting with each other we've + + align:start position:0% +were interacting with each other we've + + + align:start position:0% +were interacting with each other we've +sent only one through the time and + + align:start position:0% +sent only one through the time and + + + align:start position:0% +sent only one through the time and +waited a whole hour in between + + align:start position:0% +waited a whole hour in between + + + align:start position:0% +waited a whole hour in between +we've done that ten thousand individual + + align:start position:0% +we've done that ten thousand individual + + + align:start position:0% +we've done that ten thousand individual +times and yet the pattern that builds up + + align:start position:0% +times and yet the pattern that builds up + + + align:start position:0% +times and yet the pattern that builds up +one individual point-like detection at a + + align:start position:0% +one individual point-like detection at a + + + align:start position:0% +one individual point-like detection at a +time is this undeniable very familiar + + align:start position:0% +time is this undeniable very familiar + + + align:start position:0% +time is this undeniable very familiar +wave pattern where much as we would + + align:start position:0% +wave pattern where much as we would + + + align:start position:0% +wave pattern where much as we would +expect now from the ocean waves the + + align:start position:0% +expect now from the ocean waves the + + + align:start position:0% +expect now from the ocean waves the +resulting probability distribution goes + + align:start position:0% +resulting probability distribution goes + + + align:start position:0% +resulting probability distribution goes +like the square of the sum and + + align:start position:0% +like the square of the sum and + + + align:start position:0% +like the square of the sum and +definitely not like the sum of the + + align:start position:0% +definitely not like the sum of the + + + align:start position:0% +definitely not like the sum of the +squares it is not the sum of this + + align:start position:0% +squares it is not the sum of this + + + align:start position:0% +squares it is not the sum of this +distribution plus that one it is + + align:start position:0% +distribution plus that one it is + + + align:start position:0% +distribution plus that one it is +absolutely emphatically not like 10 000 + + align:start position:0% +absolutely emphatically not like 10 000 + + + align:start position:0% +absolutely emphatically not like 10 000 +baseballs thrown at a wall with two + + align:start position:0% +baseballs thrown at a wall with two + + + align:start position:0% +baseballs thrown at a wall with two +holes or bullets shot at some barrier it + + align:start position:0% +holes or bullets shot at some barrier it + + + align:start position:0% +holes or bullets shot at some barrier it +looks just like the water wave even + + align:start position:0% +looks just like the water wave even + + + align:start position:0% +looks just like the water wave even +though this built up over time from 10 + + align:start position:0% +though this built up over time from 10 + + + align:start position:0% +though this built up over time from 10 +000 independent events + + align:start position:0% + + + + align:start position:0% + +now if I were to unmute you all I should + + align:start position:0% +now if I were to unmute you all I should + + + align:start position:0% +now if I were to unmute you all I should +hear you screaming with either joy and + + align:start position:0% +hear you screaming with either joy and + + + align:start position:0% +hear you screaming with either joy and +ecstasy or real deep despair either way + + align:start position:0% +ecstasy or real deep despair either way + + + align:start position:0% +ecstasy or real deep despair either way +this should not be an emotionally + + align:start position:0% +this should not be an emotionally + + + align:start position:0% +this should not be an emotionally +neutral statement so what comes from all + + align:start position:0% +neutral statement so what comes from all + + + align:start position:0% +neutral statement so what comes from all +this is uh Max born the Gooding and + + align:start position:0% +this is uh Max born the Gooding and + + + align:start position:0% +this is uh Max born the Gooding and +theoristic contemporary of Einstein and + + align:start position:0% +theoristic contemporary of Einstein and + + + align:start position:0% +theoristic contemporary of Einstein and +Destroyer Heisenberg's Mentor who taught + + align:start position:0% +Destroyer Heisenberg's Mentor who taught + + + align:start position:0% +Destroyer Heisenberg's Mentor who taught +Mentor that these were matrices + + align:start position:0% +Mentor that these were matrices + + + align:start position:0% +Mentor that these were matrices +Max Bourne then suggests from exactly + + align:start position:0% +Max Bourne then suggests from exactly + + + align:start position:0% +Max Bourne then suggests from exactly +these kinds of of uh of kind of + + align:start position:0% +these kinds of of uh of kind of + + + align:start position:0% +these kinds of of uh of kind of +reasoning as early as the summer of 1926 + + align:start position:0% +reasoning as early as the summer of 1926 + + + align:start position:0% +reasoning as early as the summer of 1926 +that what is this wave side the thing + + align:start position:0% +that what is this wave side the thing + + + align:start position:0% +that what is this wave side the thing +that is a solution to Schrodinger's wave + + align:start position:0% +that is a solution to Schrodinger's wave + + + align:start position:0% +that is a solution to Schrodinger's wave +equation it seems to be not a physical + + align:start position:0% +equation it seems to be not a physical + + + align:start position:0% +equation it seems to be not a physical +bit of the electron it's not some sort + + align:start position:0% +bit of the electron it's not some sort + + + align:start position:0% +bit of the electron it's not some sort +of electron density that's spread out in + + align:start position:0% +of electron density that's spread out in + + + align:start position:0% +of electron density that's spread out in +space it seems to be related to the + + align:start position:0% +space it seems to be related to the + + + align:start position:0% +space it seems to be related to the +likely behavior of the of the associated + + align:start position:0% +likely behavior of the of the associated + + + align:start position:0% +likely behavior of the of the associated +particle it's not a physical bit of the + + align:start position:0% +particle it's not a physical bit of the + + + align:start position:0% +particle it's not a physical bit of the +particle it's a description of the way + + align:start position:0% +particle it's a description of the way + + + align:start position:0% +particle it's a description of the way +that particle is likely to behave in + + align:start position:0% +that particle is likely to behave in + + + align:start position:0% +that particle is likely to behave in +particular it's what comes to be called + + align:start position:0% +particular it's what comes to be called + + + align:start position:0% +particular it's what comes to be called +a probability amplitude not the + + align:start position:0% +a probability amplitude not the + + + align:start position:0% +a probability amplitude not the +probability not the peak uh that has + + align:start position:0% +probability not the peak uh that has + + + align:start position:0% +probability not the peak uh that has +this value on our histogram but actually + + align:start position:0% +this value on our histogram but actually + + + align:start position:0% +this value on our histogram but actually +this the object whose absolute Square + + align:start position:0% +this the object whose absolute Square + + + align:start position:0% +this the object whose absolute Square +gives rise to this to this thick black + + align:start position:0% +gives rise to this to this thick black + + + align:start position:0% +gives rise to this to this thick black +line pattern so the probability Bourne + + align:start position:0% +line pattern so the probability Bourne + + + align:start position:0% +line pattern so the probability Bourne +says we now call this born's + + align:start position:0% +says we now call this born's + + + align:start position:0% +says we now call this born's +interpretation the probability to find + + align:start position:0% +interpretation the probability to find + + + align:start position:0% +interpretation the probability to find +electron um to find an electron here + + align:start position:0% +electron um to find an electron here + + + align:start position:0% +electron um to find an electron here +versus here versus here goes like the + + align:start position:0% +versus here versus here goes like the + + + align:start position:0% +versus here versus here goes like the +absolute square of this wave like + + align:start position:0% +absolute square of this wave like + + + align:start position:0% +absolute square of this wave like +quantity Schrodinger's wave function + + align:start position:0% +quantity Schrodinger's wave function + + + align:start position:0% +quantity Schrodinger's wave function +that's what gets worked out within six + + align:start position:0% +that's what gets worked out within six + + + align:start position:0% +that's what gets worked out within six +months of Schrodinger's first + + align:start position:0% +months of Schrodinger's first + + + align:start position:0% +months of Schrodinger's first +publication on this uh in by thinking + + align:start position:0% +publication on this uh in by thinking + + + align:start position:0% +publication on this uh in by thinking +about what is actually uh observable in + + align:start position:0% +about what is actually uh observable in + + + align:start position:0% +about what is actually uh observable in +experiments involving these wave-like + + align:start position:0% +experiments involving these wave-like + + + align:start position:0% +experiments involving these wave-like +features + + align:start position:0% +features + + + align:start position:0% +features +so again that was a thought experiment + + align:start position:0% +so again that was a thought experiment + + + align:start position:0% +so again that was a thought experiment +uh in 1926 by 1920s literally by 1927 + + align:start position:0% +uh in 1926 by 1920s literally by 1927 + + + align:start position:0% +uh in 1926 by 1920s literally by 1927 +there were efforts to try to do this + + align:start position:0% +there were efforts to try to do this + + + align:start position:0% +there were efforts to try to do this +experimentally nowadays we have very + + align:start position:0% +experimentally nowadays we have very + + + align:start position:0% +experimentally nowadays we have very +fancy equipment with high Precision + + align:start position:0% +fancy equipment with high Precision + + + align:start position:0% +fancy equipment with high Precision +sources and detectors so here's a series + + align:start position:0% +sources and detectors so here's a series + + + align:start position:0% +sources and detectors so here's a series +of images courtesy from my colleagues um + + align:start position:0% +of images courtesy from my colleagues um + + + align:start position:0% +of images courtesy from my colleagues um +uh Robert Austin and Lyman page at + + align:start position:0% +uh Robert Austin and Lyman page at + + + align:start position:0% +uh Robert Austin and Lyman page at +Princeton this is not something we can + + align:start position:0% +Princeton this is not something we can + + + align:start position:0% +Princeton this is not something we can +do as an in-class demo or as an + + align:start position:0% +do as an in-class demo or as an + + + align:start position:0% +do as an in-class demo or as an +undergraduate Laboratory so these are + + align:start position:0% +undergraduate Laboratory so these are + + + align:start position:0% +undergraduate Laboratory so these are +this is real data this isn't simulated + + align:start position:0% +this is real data this isn't simulated + + + align:start position:0% +this is real data this isn't simulated +these are + + align:start position:0% +these are + + + align:start position:0% +these are +snapshots of the kind of fluorescent + + align:start position:0% +snapshots of the kind of fluorescent + + + align:start position:0% +snapshots of the kind of fluorescent +screen uh of an actual double slit + + align:start position:0% +screen uh of an actual double slit + + + align:start position:0% +screen uh of an actual double slit +experiment done at different moments in + + align:start position:0% +experiment done at different moments in + + + align:start position:0% +experiment done at different moments in +time as the pattern builds up so + + align:start position:0% +time as the pattern builds up so + + + align:start position:0% +time as the pattern builds up so +individual photons were fired out of the + + align:start position:0% +individual photons were fired out of the + + + align:start position:0% +individual photons were fired out of the +screen with two slits literally one at a + + align:start position:0% +screen with two slits literally one at a + + + align:start position:0% +screen with two slits literally one at a +time and now we can do single Photon + + align:start position:0% +time and now we can do single Photon + + + align:start position:0% +time and now we can do single Photon +experiments which is quite extraordinary + + align:start position:0% +experiments which is quite extraordinary + + + align:start position:0% +experiments which is quite extraordinary +and then you can detect where each + + align:start position:0% +and then you can detect where each + + + align:start position:0% +and then you can detect where each +individual Photon was uh was detected so + + align:start position:0% +individual Photon was uh was detected so + + + align:start position:0% +individual Photon was uh was detected so +these are little little + + align:start position:0% +these are little little + + + align:start position:0% +these are little little +pinpricks of light or an individual + + align:start position:0% +pinpricks of light or an individual + + + align:start position:0% +pinpricks of light or an individual +Photon interacted with the with the + + align:start position:0% +Photon interacted with the with the + + + align:start position:0% +Photon interacted with the with the +fluorescent photo detector so you have + + align:start position:0% +fluorescent photo detector so you have + + + align:start position:0% +fluorescent photo detector so you have +mostly black and screen because we've + + align:start position:0% +mostly black and screen because we've + + + align:start position:0% +mostly black and screen because we've +only sent a couple photons through one + + align:start position:0% +only sent a couple photons through one + + + align:start position:0% +only sent a couple photons through one +at a time so far very localized + + align:start position:0% +at a time so far very localized + + + align:start position:0% +at a time so far very localized +individual detections here and here but + + align:start position:0% +individual detections here and here but + + + align:start position:0% +individual detections here and here but +not here that's after the first one + + align:start position:0% +not here that's after the first one + + + align:start position:0% +not here that's after the first one +thirtieth of a second they're shooting + + align:start position:0% +thirtieth of a second they're shooting + + + align:start position:0% +thirtieth of a second they're shooting +rapidly one Photon at a time and only + + align:start position:0% +rapidly one Photon at a time and only + + + align:start position:0% +rapidly one Photon at a time and only +one at a time + + align:start position:0% +one at a time + + + align:start position:0% +one at a time +after a whole second has gone by you + + align:start position:0% +after a whole second has gone by you + + + align:start position:0% +after a whole second has gone by you +have accumulating pattern now you have + + align:start position:0% +have accumulating pattern now you have + + + align:start position:0% +have accumulating pattern now you have +several hundred photons individually + + align:start position:0% +several hundred photons individually + + + align:start position:0% +several hundred photons individually +detected + + align:start position:0% +detected + + + align:start position:0% +detected +wait a hundred seconds and you see very + + align:start position:0% +wait a hundred seconds and you see very + + + align:start position:0% +wait a hundred seconds and you see very +clearly this wave like interference + + align:start position:0% +clearly this wave like interference + + + align:start position:0% +clearly this wave like interference +pattern exactly the pattern described by + + align:start position:0% +pattern exactly the pattern described by + + + align:start position:0% +pattern exactly the pattern described by +that by that born interpretation even + + align:start position:0% +that by that born interpretation even + + + align:start position:0% +that by that born interpretation even +though this is built from thousands of + + align:start position:0% +though this is built from thousands of + + + align:start position:0% +though this is built from thousands of +otherwise Independents located in time + + align:start position:0% +otherwise Independents located in time + + + align:start position:0% +otherwise Independents located in time +and space detections of individual + + align:start position:0% +and space detections of individual + + + align:start position:0% +and space detections of individual +Quantum so we have we we shoot out + + align:start position:0% +Quantum so we have we we shoot out + + + align:start position:0% +Quantum so we have we we shoot out +individual quanta particulate like we + + align:start position:0% +individual quanta particulate like we + + + align:start position:0% +individual quanta particulate like we +detect individual quanta particularly + + align:start position:0% +detect individual quanta particularly + + + align:start position:0% +detect individual quanta particularly +like and they can interfere with each + + align:start position:0% +like and they can interfere with each + + + align:start position:0% +like and they can interfere with each +other because we make sure only one's + + align:start position:0% +other because we make sure only one's + + + align:start position:0% +other because we make sure only one's +sort of in the device at a time and yet + + align:start position:0% +sort of in the device at a time and yet + + + align:start position:0% +sort of in the device at a time and yet +over time they somehow build up this + + align:start position:0% +over time they somehow build up this + + + align:start position:0% +over time they somehow build up this +very characteristic wave-like + + align:start position:0% +very characteristic wave-like + + + align:start position:0% +very characteristic wave-like +interference pattern that is what's + + align:start position:0% +interference pattern that is what's + + + align:start position:0% +interference pattern that is what's +called the double slit experiment so let + + align:start position:0% +called the double slit experiment so let + + + align:start position:0% +called the double slit experiment so let +me pause there + + align:start position:0% +me pause there + + + align:start position:0% +me pause there +how do we go from one electron every + + align:start position:0% +how do we go from one electron every + + + align:start position:0% +how do we go from one electron every +hour to 100 uh every second oh good so + + align:start position:0% +hour to 100 uh every second oh good so + + + align:start position:0% +hour to 100 uh every second oh good so +Alex good question so uh the the data I + + align:start position:0% +Alex good question so uh the the data I + + + align:start position:0% +Alex good question so uh the the data I +just showed was actually with photons uh + + align:start position:0% +just showed was actually with photons uh + + + align:start position:0% +just showed was actually with photons uh +the Princeton group you one can do with + + align:start position:0% +the Princeton group you one can do with + + + align:start position:0% +the Princeton group you one can do with +electrons as well uh they were using uh + + align:start position:0% +electrons as well uh they were using uh + + + align:start position:0% +electrons as well uh they were using uh +uh let's say a + + align:start position:0% +uh let's say a + + + align:start position:0% +uh let's say a +a photon source that emits single + + align:start position:0% +a photon source that emits single + + + align:start position:0% +a photon source that emits single +photons rapidly so they really were + + align:start position:0% +photons rapidly so they really were + + + align:start position:0% +photons rapidly so they really were +shooting out only one Photon at a time + + align:start position:0% +shooting out only one Photon at a time + + + align:start position:0% +shooting out only one Photon at a time +but they can produce many photons per + + align:start position:0% +but they can produce many photons per + + + align:start position:0% +but they can produce many photons per +second so the timing when we're dealing + + align:start position:0% +second so the timing when we're dealing + + + align:start position:0% +second so the timing when we're dealing +that with that particular source of + + align:start position:0% +that with that particular source of + + + align:start position:0% +that with that particular source of +individual quantity this the time that + + align:start position:0% +individual quantity this the time that + + + align:start position:0% +individual quantity this the time that +What's called the duty cycle shorter we + + align:start position:0% +What's called the duty cycle shorter we + + + align:start position:0% +What's called the duty cycle shorter we +also have very rapid Electronics now in + + align:start position:0% +also have very rapid Electronics now in + + + align:start position:0% +also have very rapid Electronics now in +like 1927. so the electronics can + + align:start position:0% +like 1927. so the electronics can + + + align:start position:0% +like 1927. so the electronics can +actually actually resolve individual + + align:start position:0% +actually actually resolve individual + + + align:start position:0% +actually actually resolve individual +detections in a tiny fraction a second + + align:start position:0% +detections in a tiny fraction a second + + + align:start position:0% +detections in a tiny fraction a second +so conceptually it's as if we had gone + + align:start position:0% +so conceptually it's as if we had gone + + + align:start position:0% +so conceptually it's as if we had gone +back to my cartoon turned on our machine + + align:start position:0% +back to my cartoon turned on our machine + + + align:start position:0% +back to my cartoon turned on our machine +shot out one particle turn it off went + + align:start position:0% +shot out one particle turn it off went + + + align:start position:0% +shot out one particle turn it off went +away it's just now we can do that with + + align:start position:0% +away it's just now we can do that with + + + align:start position:0% +away it's just now we can do that with +with um with a kind of high duty cycle + + align:start position:0% +with um with a kind of high duty cycle + + + align:start position:0% +with um with a kind of high duty cycle +rapid Electronics but but conceptually + + align:start position:0% +rapid Electronics but but conceptually + + + align:start position:0% +rapid Electronics but but conceptually +it to my mind it's quite similar + + align:start position:0% +it to my mind it's quite similar + + + align:start position:0% +it to my mind it's quite similar +uh Vittorio asks how as you do the + + align:start position:0% +uh Vittorio asks how as you do the + + + align:start position:0% +uh Vittorio asks how as you do the +experiment with progressively heavier + + align:start position:0% +experiment with progressively heavier + + + align:start position:0% +experiment with progressively heavier +particles oh good question is there a + + align:start position:0% +particles oh good question is there a + + + align:start position:0% +particles oh good question is there a +certain point when the resulting pattern + + align:start position:0% +certain point when the resulting pattern + + + align:start position:0% +certain point when the resulting pattern +begins to look like what you'd expect + + align:start position:0% +begins to look like what you'd expect + + + align:start position:0% +begins to look like what you'd expect +from two bullets oh thank you Victoria + + align:start position:0% +from two bullets oh thank you Victoria + + + align:start position:0% +from two bullets oh thank you Victoria +what a wonderful question + + align:start position:0% +what a wonderful question + + + align:start position:0% +what a wonderful question +that is a question uh that is still + + align:start position:0% +that is a question uh that is still + + + align:start position:0% +that is a question uh that is still +occupying literally many of my friends + + align:start position:0% +occupying literally many of my friends + + + align:start position:0% +occupying literally many of my friends +let alone colleagues around the world + + align:start position:0% +let alone colleagues around the world + + + align:start position:0% +let alone colleagues around the world +the short answer is yes the longer + + align:start position:0% +the short answer is yes the longer + + + align:start position:0% +the short answer is yes the longer +answer is + + align:start position:0% +answer is + + + align:start position:0% +answer is +um is why and how and Jade's quite right + + align:start position:0% +um is why and how and Jade's quite right + + + align:start position:0% +um is why and how and Jade's quite right +uh Jade it puts in the chat this + + align:start position:0% +uh Jade it puts in the chat this + + + align:start position:0% +uh Jade it puts in the chat this +experiment has been done a comparable + + align:start position:0% +experiment has been done a comparable + + + align:start position:0% +experiment has been done a comparable +experiment with objects as large as + + align:start position:0% +experiment with objects as large as + + + align:start position:0% +experiment with objects as large as +Buckyballs C60 molecules of 60 carbon + + align:start position:0% +Buckyballs C60 molecules of 60 carbon + + + align:start position:0% +Buckyballs C60 molecules of 60 carbon +atoms in one bound State not just + + align:start position:0% +atoms in one bound State not just + + + align:start position:0% +atoms in one bound State not just +individual electrons so an object as + + align:start position:0% +individual electrons so an object as + + + align:start position:0% +individual electrons so an object as +long as large as a buckyball which is I + + align:start position:0% +long as large as a buckyball which is I + + + align:start position:0% +long as large as a buckyball which is I +think not a billion but several tens of + + align:start position:0% +think not a billion but several tens of + + + align:start position:0% +think not a billion but several tens of +millions of times larger than an + + align:start position:0% +millions of times larger than an + + + align:start position:0% +millions of times larger than an +individual electron + + align:start position:0% +individual electron + + + align:start position:0% +individual electron +we still find this characteristic + + align:start position:0% +we still find this characteristic + + + align:start position:0% +we still find this characteristic +Quantum interference very clearly again + + align:start position:0% +Quantum interference very clearly again + + + align:start position:0% +Quantum interference very clearly again +it's sort of uh well within statistical + + align:start position:0% +it's sort of uh well within statistical + + + align:start position:0% +it's sort of uh well within statistical +uh you know significance and in fact + + align:start position:0% +uh you know significance and in fact + + + align:start position:0% +uh you know significance and in fact +that's an experiment that one of my + + align:start position:0% +that's an experiment that one of my + + + align:start position:0% +that's an experiment that one of my +colleagues Anton zyler and his group had + + align:start position:0% +colleagues Anton zyler and his group had + + + align:start position:0% +colleagues Anton zyler and his group had +done quite some time ago + + align:start position:0% +done quite some time ago + + + align:start position:0% +done quite some time ago +so the question is where does that stop + + align:start position:0% +so the question is where does that stop + + + align:start position:0% +so the question is where does that stop +I had I had a very beloved physics + + align:start position:0% +I had I had a very beloved physics + + + align:start position:0% +I had I had a very beloved physics +professor of my own uh when I was an + + align:start position:0% +professor of my own uh when I was an + + + align:start position:0% +professor of my own uh when I was an +undergraduate it was very senior he'd + + align:start position:0% +undergraduate it was very senior he'd + + + align:start position:0% +undergraduate it was very senior he'd +actually just retired we're still + + align:start position:0% +actually just retired we're still + + + align:start position:0% +actually just retired we're still +teaching uh just for fun and he used to + + align:start position:0% +teaching uh just for fun and he used to + + + align:start position:0% +teaching uh just for fun and he used to +joke that when he was in graduate school + + align:start position:0% +joke that when he was in graduate school + + + align:start position:0% +joke that when he was in graduate school +he and his buddies would wonder could + + align:start position:0% +he and his buddies would wonder could + + + align:start position:0% +he and his buddies would wonder could +they get themselves to interfere if they + + align:start position:0% +they get themselves to interfere if they + + + align:start position:0% +they get themselves to interfere if they +rode their bicycle through two standing + + align:start position:0% +rode their bicycle through two standing + + + align:start position:0% +rode their bicycle through two standing +posts efficiently quickly like what + + align:start position:0% +posts efficiently quickly like what + + + align:start position:0% +posts efficiently quickly like what +something when when they don't interfere + + align:start position:0% +something when when they don't interfere + + + align:start position:0% +something when when they don't interfere +with themselves right an individual + + align:start position:0% +with themselves right an individual + + + align:start position:0% +with themselves right an individual +human on a bicycle doesn't undergo uh at + + align:start position:0% +human on a bicycle doesn't undergo uh at + + + align:start position:0% +human on a bicycle doesn't undergo uh at +least not in any obvious way this kind + + align:start position:0% +least not in any obvious way this kind + + + align:start position:0% +least not in any obvious way this kind +of interference it doesn't seem to + + align:start position:0% +of interference it doesn't seem to + + + align:start position:0% +of interference it doesn't seem to +happen with + + align:start position:0% +happen with + + + align:start position:0% +happen with +um + + align:start position:0% +um + + + align:start position:0% +um +with with things we could shrink down to + + align:start position:0% +with with things we could shrink down to + + + align:start position:0% +with with things we could shrink down to +look at microscopically uh at the scale + + align:start position:0% +look at microscopically uh at the scale + + + align:start position:0% +look at microscopically uh at the scale +of say amoebas which people have tried + + align:start position:0% +of say amoebas which people have tried + + + align:start position:0% +of say amoebas which people have tried +but it does happen with you know + + align:start position:0% +but it does happen with you know + + + align:start position:0% +but it does happen with you know +enormous molecules enormous on the size + + align:start position:0% +enormous molecules enormous on the size + + + align:start position:0% +enormous molecules enormous on the size +of parts of atoms so where is that line + + align:start position:0% +of parts of atoms so where is that line + + + align:start position:0% +of parts of atoms so where is that line +and and what causes the transition and + + align:start position:0% +and and what causes the transition and + + + align:start position:0% +and and what causes the transition and +behavior if we're all made up of atoms + + align:start position:0% +behavior if we're all made up of atoms + + + align:start position:0% +behavior if we're all made up of atoms +and electrons and electrons and atoms + + align:start position:0% +and electrons and electrons and atoms + + + align:start position:0% +and electrons and electrons and atoms +behave in this fundamentally quantum + + align:start position:0% +behave in this fundamentally quantum + + + align:start position:0% +behave in this fundamentally quantum +mechanical way why don't we why don't + + align:start position:0% +mechanical way why don't we why don't + + + align:start position:0% +mechanical way why don't we why don't +why why didn't my professor on his + + align:start position:0% +why why didn't my professor on his + + + align:start position:0% +why why didn't my professor on his +bicycle uh get diffracted when he when + + align:start position:0% +bicycle uh get diffracted when he when + + + align:start position:0% +bicycle uh get diffracted when he when +he biked through between two uh standing + + align:start position:0% +he biked through between two uh standing + + + align:start position:0% +he biked through between two uh standing +posts so that's what's often now called + + align:start position:0% +posts so that's what's often now called + + + align:start position:0% +posts so that's what's often now called +the the quantum to classical transition + + align:start position:0% +the the quantum to classical transition + + + align:start position:0% +the the quantum to classical transition +if you have nothing better to do with + + align:start position:0% +if you have nothing better to do with + + + align:start position:0% +if you have nothing better to do with +yourself in the next 17 years I suggest + + align:start position:0% +yourself in the next 17 years I suggest + + + align:start position:0% +yourself in the next 17 years I suggest +you start googling that and read every + + align:start position:0% +you start googling that and read every + + + align:start position:0% +you start googling that and read every +paper on it it's enormously complicated + + align:start position:0% +paper on it it's enormously complicated + + + align:start position:0% +paper on it it's enormously complicated +and still very much on the Forefront of + + align:start position:0% +and still very much on the Forefront of + + + align:start position:0% +and still very much on the Forefront of +the research Frontier for many people + + align:start position:0% +the research Frontier for many people + + + align:start position:0% +the research Frontier for many people +and we and we just January collectively + + align:start position:0% +and we and we just January collectively + + + align:start position:0% +and we and we just January collectively +the community genuinely doesn't know + + align:start position:0% +the community genuinely doesn't know + + + align:start position:0% +the community genuinely doesn't know +we're getting better at characterizing + + align:start position:0% +we're getting better at characterizing + + + align:start position:0% +we're getting better at characterizing +where the break is where the line is but + + align:start position:0% +where the break is where the line is but + + + align:start position:0% +where the break is where the line is but +not why and not what would cause the + + align:start position:0% +not why and not what would cause the + + + align:start position:0% +not why and not what would cause the +behavior to transition from one very + + align:start position:0% +behavior to transition from one very + + + align:start position:0% +behavior to transition from one very +specific kind of behavior to the other + + align:start position:0% +specific kind of behavior to the other + + + align:start position:0% +specific kind of behavior to the other +what about so other colleagues are + + align:start position:0% +what about so other colleagues are + + + align:start position:0% +what about so other colleagues are +trying to do this with living objects so + + align:start position:0% +trying to do this with living objects so + + + align:start position:0% +trying to do this with living objects so +it turns out viruses some kinds of + + align:start position:0% +it turns out viruses some kinds of + + + align:start position:0% +it turns out viruses some kinds of +viruses might be just small enough for + + align:start position:0% +viruses might be just small enough for + + + align:start position:0% +viruses might be just small enough for +this to work and yet much much bigger + + align:start position:0% +this to work and yet much much bigger + + + align:start position:0% +this to work and yet much much bigger +than Buckyballs so people are trying to + + align:start position:0% +than Buckyballs so people are trying to + + + align:start position:0% +than Buckyballs so people are trying to +get living things seemingly living + + align:start position:0% +get living things seemingly living + + + align:start position:0% +get living things seemingly living +things like viruses to Quantum age of + + align:start position:0% +things like viruses to Quantum age of + + + align:start position:0% +things like viruses to Quantum age of +fear that's not been done yet but that's + + align:start position:0% +fear that's not been done yet but that's + + + align:start position:0% +fear that's not been done yet but that's +one thing people are trying so this this + + align:start position:0% +one thing people are trying so this this + + + align:start position:0% +one thing people are trying so this this +question of how big could it get and + + align:start position:0% +question of how big could it get and + + + align:start position:0% +question of how big could it get and +still show this inherent quantumness + + align:start position:0% +still show this inherent quantumness + + + align:start position:0% +still show this inherent quantumness +that is uh still very much a live issue + + align:start position:0% +that is uh still very much a live issue + + + align:start position:0% +that is uh still very much a live issue +and and there's as it is too fast as to + + align:start position:0% +and and there's as it is too fast as to + + + align:start position:0% +and and there's as it is too fast as to +it what's the scale but even more subtly + + align:start position:0% +it what's the scale but even more subtly + + + align:start position:0% +it what's the scale but even more subtly +what's the reason why that stops working + + align:start position:0% +what's the reason why that stops working + + + align:start position:0% +what's the reason why that stops working +as we continue making it considering + + align:start position:0% +as we continue making it considering + + + align:start position:0% +as we continue making it considering +larger objects so so thank you for that + + align:start position:0% +larger objects so so thank you for that + + + align:start position:0% +larger objects so so thank you for that +question great question + + align:start position:0% +question great question + + + align:start position:0% +question great question +any other questions about the double + + align:start position:0% +any other questions about the double + + + align:start position:0% +any other questions about the double +slit about this um what should have been + + align:start position:0% +slit about this um what should have been + + + align:start position:0% +slit about this um what should have been +the the sort of you know the scream I + + align:start position:0% +the the sort of you know the scream I + + + align:start position:0% +the the sort of you know the scream I +mean all of these should have just been + + align:start position:0% +mean all of these should have just been + + + align:start position:0% +mean all of these should have just been +unmuted just + + align:start position:0% +unmuted just + + + align:start position:0% +unmuted just +just howling at the moon at least that's + + align:start position:0% +just howling at the moon at least that's + + + align:start position:0% +just howling at the moon at least that's +how I feel and I still think about this + + align:start position:0% +how I feel and I still think about this + + + align:start position:0% +how I feel and I still think about this +maybe that's maybe that's my problem I + + align:start position:0% +maybe that's maybe that's my problem I + + + align:start position:0% +maybe that's maybe that's my problem I +just find that just astonishing people + + align:start position:0% +just find that just astonishing people + + + align:start position:0% +just find that just astonishing people +that it's not just a thought experiment + + align:start position:0% +that it's not just a thought experiment + + + align:start position:0% +that it's not just a thought experiment +we can do that now with individual + + align:start position:0% +we can do that now with individual + + + align:start position:0% +we can do that now with individual +Quantum with super careful control on + + align:start position:0% +Quantum with super careful control on + + + align:start position:0% +Quantum with super careful control on +our source on our detectors have really + + align:start position:0% +our source on our detectors have really + + + align:start position:0% +our source on our detectors have really +extraordinarily High statistical + + align:start position:0% +extraordinarily High statistical + + + align:start position:0% +extraordinarily High statistical +significance on all the measurements + + align:start position:0% +significance on all the measurements + + + align:start position:0% +significance on all the measurements +and and fire what looked for all intents + + align:start position:0% +and and fire what looked for all intents + + + align:start position:0% +and and fire what looked for all intents +and purpose to be like little tiny + + align:start position:0% +and purpose to be like little tiny + + + align:start position:0% +and purpose to be like little tiny +baseballs + + align:start position:0% +baseballs + + + align:start position:0% +baseballs +and somehow they know somehow their + + align:start position:0% +and somehow they know somehow their + + + align:start position:0% +and somehow they know somehow their +behavior is guided in a way that that + + align:start position:0% +behavior is guided in a way that that + + + align:start position:0% +behavior is guided in a way that that +baseballs and bullets just just aren't + + align:start position:0% +baseballs and bullets just just aren't + + + align:start position:0% +baseballs and bullets just just aren't +your basketballs + + align:start position:0% + + + + align:start position:0% + +if that's just okay for all of you then + + align:start position:0% +if that's just okay for all of you then + + + align:start position:0% +if that's just okay for all of you then +I mean come on that's just like that's + + align:start position:0% +I mean come on that's just like that's + + + align:start position:0% +I mean come on that's just like that's +covet speaking that should just + + align:start position:0% +covet speaking that should just + + + align:start position:0% +covet speaking that should just +okay you get the point any other + + align:start position:0% +okay you get the point any other + + + align:start position:0% +okay you get the point any other +questions on either my mental state or + + align:start position:0% +questions on either my mental state or + + + align:start position:0% +questions on either my mental state or +emotional state or on uh the double slit + + align:start position:0% +emotional state or on uh the double slit + + + align:start position:0% +emotional state or on uh the double slit +experiment if not we'll go into one last + + align:start position:0% +experiment if not we'll go into one last + + + align:start position:0% +experiment if not we'll go into one last +little part one kind of Coda for double + + align:start position:0% +little part one kind of Coda for double + + + align:start position:0% +little part one kind of Coda for double +sit and then we'll have time for + + align:start position:0% +sit and then we'll have time for + + + align:start position:0% +sit and then we'll have time for +questions as well + + align:start position:0% +questions as well + + + align:start position:0% +questions as well +okay so I'll get it together I'll put + + align:start position:0% +okay so I'll get it together I'll put + + + align:start position:0% +okay so I'll get it together I'll put +myself together I'll talk now about this + + align:start position:0% +myself together I'll talk now about this + + + align:start position:0% +myself together I'll talk now about this +last part uh which also started being + + align:start position:0% +last part uh which also started being + + + align:start position:0% +last part uh which also started being +thought thought about very early uh even + + align:start position:0% +thought thought about very early uh even + + + align:start position:0% +thought thought about very early uh even +in the in the late 1920s as further ways + + align:start position:0% +in the in the late 1920s as further ways + + + align:start position:0% +in the in the late 1920s as further ways +to try to probe what's going on when we + + align:start position:0% +to try to probe what's going on when we + + + align:start position:0% +to try to probe what's going on when we +think about this Quantum level so again + + align:start position:0% +think about this Quantum level so again + + + align:start position:0% +think about this Quantum level so again +this I'm going to do especially + + align:start position:0% +this I'm going to do especially + + + align:start position:0% +this I'm going to do especially +schematically in in the class session + + align:start position:0% +schematically in in the class session + + + align:start position:0% +schematically in in the class session +there is a bit more uh explicit + + align:start position:0% +there is a bit more uh explicit + + + align:start position:0% +there is a bit more uh explicit +discussion in the in the optional + + align:start position:0% +discussion in the in the optional + + + align:start position:0% +discussion in the in the optional +lecture notes on the course site + + align:start position:0% +lecture notes on the course site + + + align:start position:0% +lecture notes on the course site +let's go back to that same setup the one + + align:start position:0% +let's go back to that same setup the one + + + align:start position:0% +let's go back to that same setup the one +we just ended on let's say we're sending + + align:start position:0% +we just ended on let's say we're sending + + + align:start position:0% +we just ended on let's say we're sending +one electron at a time uh waiting in you + + align:start position:0% +one electron at a time uh waiting in you + + + align:start position:0% +one electron at a time uh waiting in you +know uh ample time in between + + align:start position:0% +know uh ample time in between + + + align:start position:0% +know uh ample time in between +firing them toward this this uh system + + align:start position:0% +firing them toward this this uh system + + + align:start position:0% +firing them toward this this uh system +with a where the distance between this A + + align:start position:0% +with a where the distance between this A + + + align:start position:0% +with a where the distance between this A +and B is much much larger than uh the + + align:start position:0% +and B is much much larger than uh the + + + align:start position:0% +and B is much much larger than uh the +kind of characteristic size of of the + + align:start position:0% +kind of characteristic size of of the + + + align:start position:0% +kind of characteristic size of of the +particles themselves but now we want to + + align:start position:0% +particles themselves but now we want to + + + align:start position:0% +particles themselves but now we want to +say these particles clearly must have + + align:start position:0% +say these particles clearly must have + + + align:start position:0% +say these particles clearly must have +gone through either slit a or split B + + align:start position:0% +gone through either slit a or split B + + + align:start position:0% +gone through either slit a or split B +that seems like a reasonable + + align:start position:0% +that seems like a reasonable + + + align:start position:0% +that seems like a reasonable +question to ponder which slit do they + + align:start position:0% +question to ponder which slit do they + + + align:start position:0% +question to ponder which slit do they +pass through on any individual + + align:start position:0% +pass through on any individual + + + align:start position:0% +pass through on any individual +experimental rut the distance between + + align:start position:0% +experimental rut the distance between + + + align:start position:0% +experimental rut the distance between +this the slits is so much larger than + + align:start position:0% +this the slits is so much larger than + + + align:start position:0% +this the slits is so much larger than +the character size the the each particle + + align:start position:0% +the character size the the each particle + + + align:start position:0% +the character size the the each particle +must have had to have selected must have + + align:start position:0% +must have had to have selected must have + + + align:start position:0% +must have had to have selected must have +had to have chosen to go through either + + align:start position:0% +had to have chosen to go through either + + + align:start position:0% +had to have chosen to go through either +slit a or slit B + + align:start position:0% +slit a or slit B + + + align:start position:0% +slit a or slit B +so why don't we try to find out and this + + align:start position:0% +so why don't we try to find out and this + + + align:start position:0% +so why don't we try to find out and this +was a very clever idea Heisenberg + + align:start position:0% +was a very clever idea Heisenberg + + + align:start position:0% +was a very clever idea Heisenberg +lectures on this even in those 1929 + + align:start position:0% +lectures on this even in those 1929 + + + align:start position:0% +lectures on this even in those 1929 +lectures and others have developed it + + align:start position:0% +lectures and others have developed it + + + align:start position:0% +lectures and others have developed it +since then let's put a bunch of test + + align:start position:0% +since then let's put a bunch of test + + + align:start position:0% +since then let's put a bunch of test +particles behind only one of the slits + + align:start position:0% +particles behind only one of the slits + + + align:start position:0% +particles behind only one of the slits +so that way it'll be like an alarm + + align:start position:0% +so that way it'll be like an alarm + + + align:start position:0% +so that way it'll be like an alarm +system if an electron happens to go + + align:start position:0% +system if an electron happens to go + + + align:start position:0% +system if an electron happens to go +through slit a it'll it'll smack into + + align:start position:0% +through slit a it'll it'll smack into + + + align:start position:0% +through slit a it'll it'll smack into +these test particles we'll have + + align:start position:0% +these test particles we'll have + + + align:start position:0% +these test particles we'll have +collisions we'll have scattered + + align:start position:0% +collisions we'll have scattered + + + align:start position:0% +collisions we'll have scattered +particles zooming out of this region of + + align:start position:0% +particles zooming out of this region of + + + align:start position:0% +particles zooming out of this region of +the experiment that we could then detect + + align:start position:0% +the experiment that we could then detect + + + align:start position:0% +the experiment that we could then detect +and measure and if no test particles are + + align:start position:0% +and measure and if no test particles are + + + align:start position:0% +and measure and if no test particles are +scattered then we know the electron must + + align:start position:0% +scattered then we know the electron must + + + align:start position:0% +scattered then we know the electron must +have gone through the other slip so + + align:start position:0% +have gone through the other slip so + + + align:start position:0% +have gone through the other slip so +we're going to Bunch together get in a + + align:start position:0% +we're going to Bunch together get in a + + + align:start position:0% +we're going to Bunch together get in a +kind of close in space some targets + + align:start position:0% +kind of close in space some targets + + + align:start position:0% +kind of close in space some targets +behind only one of the two open slits + + align:start position:0% +behind only one of the two open slits + + + align:start position:0% +behind only one of the two open slits +and that way we have what's called a + + align:start position:0% +and that way we have what's called a + + + align:start position:0% +and that way we have what's called a +slit detector we have some mechanism of + + align:start position:0% +slit detector we have some mechanism of + + + align:start position:0% +slit detector we have some mechanism of +determining event by event through which + + align:start position:0% +determining event by event through which + + + align:start position:0% +determining event by event through which +slit the particle actually passed + + align:start position:0% +slit the particle actually passed + + + align:start position:0% +slit the particle actually passed +uh + + align:start position:0% +uh + + + align:start position:0% +uh +and so now what happens when both slits + + align:start position:0% +and so now what happens when both slits + + + align:start position:0% +and so now what happens when both slits +are open but we measure through these + + align:start position:0% +are open but we measure through these + + + align:start position:0% +are open but we measure through these +slip detectors through which slit each + + align:start position:0% +slip detectors through which slit each + + + align:start position:0% +slip detectors through which slit each +electron passed then the distribution + + align:start position:0% +electron passed then the distribution + + + align:start position:0% +electron passed then the distribution +even for these quantum mechanical + + align:start position:0% +even for these quantum mechanical + + + align:start position:0% +even for these quantum mechanical +electrons the distribution reverts back + + align:start position:0% +electrons the distribution reverts back + + + align:start position:0% +electrons the distribution reverts back +to this thoroughly + + align:start position:0% +to this thoroughly + + + align:start position:0% +to this thoroughly +classical sum of two independent + + align:start position:0% +classical sum of two independent + + + align:start position:0% +classical sum of two independent +probabilities + + align:start position:0% +probabilities + + + align:start position:0% +probabilities +so we do our usual experiment we do this + + align:start position:0% +so we do our usual experiment we do this + + + align:start position:0% +so we do our usual experiment we do this +10 000 times sometimes we see the + + align:start position:0% +10 000 times sometimes we see the + + + align:start position:0% +10 000 times sometimes we see the +scattered particles from behind slit a + + align:start position:0% +scattered particles from behind slit a + + + align:start position:0% +scattered particles from behind slit a +sometimes we see no scattered particles + + align:start position:0% +sometimes we see no scattered particles + + + align:start position:0% +sometimes we see no scattered particles +it must have gone through slip B and + + align:start position:0% +it must have gone through slip B and + + + align:start position:0% +it must have gone through slip B and +then separately from that we count up + + align:start position:0% +then separately from that we count up + + + align:start position:0% +then separately from that we count up +where do all the electrons actually wind + + align:start position:0% +where do all the electrons actually wind + + + align:start position:0% +where do all the electrons actually wind +up + + align:start position:0% +up + + + align:start position:0% +up +at that backstop with our closely spaced + + align:start position:0% +at that backstop with our closely spaced + + + align:start position:0% +at that backstop with our closely spaced +detectors and we get basically the + + align:start position:0% +detectors and we get basically the + + + align:start position:0% +detectors and we get basically the +classical distribution it looks like the + + align:start position:0% +classical distribution it looks like the + + + align:start position:0% +classical distribution it looks like the +sum of two independent classical + + align:start position:0% +sum of two independent classical + + + align:start position:0% +sum of two independent classical +particle-like distributions when we ask + + align:start position:0% +particle-like distributions when we ask + + + align:start position:0% +particle-like distributions when we ask +through which slit each individual each + + align:start position:0% +through which slit each individual each + + + align:start position:0% +through which slit each individual each +individual particle passed the particles + + align:start position:0% +individual particle passed the particles + + + align:start position:0% +individual particle passed the particles +give us a particle-like answer they pass + + align:start position:0% +give us a particle-like answer they pass + + + align:start position:0% +give us a particle-like answer they pass +through I just let a or slit B and had + + align:start position:0% +through I just let a or slit B and had + + + align:start position:0% +through I just let a or slit B and had +correspondingly no interference pattern + + align:start position:0% +correspondingly no interference pattern + + + align:start position:0% +correspondingly no interference pattern +between those two options + + align:start position:0% +between those two options + + + align:start position:0% +between those two options +on the other hand I mean don't even try + + align:start position:0% +on the other hand I mean don't even try + + + align:start position:0% +on the other hand I mean don't even try +to ask through which slit do those + + align:start position:0% +to ask through which slit do those + + + align:start position:0% +to ask through which slit do those +individual particles pass we remove that + + align:start position:0% +individual particles pass we remove that + + + align:start position:0% +individual particles pass we remove that +slit detector altogether then we get + + align:start position:0% +slit detector altogether then we get + + + align:start position:0% +slit detector altogether then we get +back to the results that we'd already + + align:start position:0% +back to the results that we'd already + + + align:start position:0% +back to the results that we'd already +found that when both slits are open we + + align:start position:0% +found that when both slits are open we + + + align:start position:0% +found that when both slits are open we +get this characteristic wave like + + align:start position:0% +get this characteristic wave like + + + align:start position:0% +get this characteristic wave like +interference pattern for and we only get + + align:start position:0% +interference pattern for and we only get + + + align:start position:0% +interference pattern for and we only get +that when we've given up even the + + align:start position:0% +that when we've given up even the + + + align:start position:0% +that when we've given up even the +opportunity to ask this particle-like + + align:start position:0% +opportunity to ask this particle-like + + + align:start position:0% +opportunity to ask this particle-like +question about which slit uh had + + align:start position:0% +question about which slit uh had + + + align:start position:0% +question about which slit uh had +actually uh through which that had + + align:start position:0% +actually uh through which that had + + + align:start position:0% +actually uh through which that had +individual particles passed so we are + + align:start position:0% +individual particles passed so we are + + + align:start position:0% +individual particles passed so we are +allowed to ask a question we actually + + align:start position:0% +allowed to ask a question we actually + + + align:start position:0% +allowed to ask a question we actually +can ask the question that people have + + align:start position:0% +can ask the question that people have + + + align:start position:0% +can ask the question that people have +done it with a slightly more + + align:start position:0% +done it with a slightly more + + + align:start position:0% +done it with a slightly more +sophisticated version than just that + + align:start position:0% +sophisticated version than just that + + + align:start position:0% +sophisticated version than just that +cartoon and yet somehow the nature of + + align:start position:0% +cartoon and yet somehow the nature of + + + align:start position:0% +cartoon and yet somehow the nature of +the results changes very deeply and + + align:start position:0% +the results changes very deeply and + + + align:start position:0% +the results changes very deeply and +fundamentally based on the nature of the + + align:start position:0% +fundamentally based on the nature of the + + + align:start position:0% +fundamentally based on the nature of the +question we asked + + align:start position:0% +question we asked + + + align:start position:0% +question we asked +so again you can see why that happens + + align:start position:0% +so again you can see why that happens + + + align:start position:0% +so again you can see why that happens +that's really I'm being pretty schematic + + align:start position:0% +that's really I'm being pretty schematic + + + align:start position:0% +that's really I'm being pretty schematic +and kind of waving my hands it's only a + + align:start position:0% +and kind of waving my hands it's only a + + + align:start position:0% +and kind of waving my hands it's only a +couple lines of algebra and you might + + align:start position:0% +couple lines of algebra and you might + + + align:start position:0% +couple lines of algebra and you might +have already guessed it if I go back to + + align:start position:0% +have already guessed it if I go back to + + + align:start position:0% +have already guessed it if I go back to +cartoon + + align:start position:0% +cartoon + + + align:start position:0% +cartoon +just to say quickly what's going to + + align:start position:0% +just to say quickly what's going to + + + align:start position:0% +just to say quickly what's going to +happen here in order for this to be a + + align:start position:0% +happen here in order for this to be a + + + align:start position:0% +happen here in order for this to be a +reliable slip detector this bundle of + + align:start position:0% +reliable slip detector this bundle of + + + align:start position:0% +reliable slip detector this bundle of +particles has to really be behind a and + + align:start position:0% +particles has to really be behind a and + + + align:start position:0% +particles has to really be behind a and +not behind B that means that the spread + + align:start position:0% +not behind B that means that the spread + + + align:start position:0% +not behind B that means that the spread +in space can't be arbitrarily large if + + align:start position:0% +in space can't be arbitrarily large if + + + align:start position:0% +in space can't be arbitrarily large if +we call this vertical Direction the Y + + align:start position:0% +we call this vertical Direction the Y + + + align:start position:0% +we call this vertical Direction the Y +Direction like my arrow here shows then + + align:start position:0% +Direction like my arrow here shows then + + + align:start position:0% +Direction like my arrow here shows then +the Delta y of this distribution can't + + align:start position:0% +the Delta y of this distribution can't + + + align:start position:0% +the Delta y of this distribution can't +be too big in fact it has to be much + + align:start position:0% +be too big in fact it has to be much + + + align:start position:0% +be too big in fact it has to be much +smaller than the distance d + + align:start position:0% +smaller than the distance d + + + align:start position:0% +smaller than the distance d +if the distribution were too big then we + + align:start position:0% +if the distribution were too big then we + + + align:start position:0% +if the distribution were too big then we +could see that test particles were + + align:start position:0% +could see that test particles were + + + align:start position:0% +could see that test particles were +scattered into but they would no longer + + align:start position:0% +scattered into but they would no longer + + + align:start position:0% +scattered into but they would no longer +tell us whether the particle had gone + + align:start position:0% +tell us whether the particle had gone + + + align:start position:0% +tell us whether the particle had gone +through a or slip B we would lose the + + align:start position:0% +through a or slip B we would lose the + + + align:start position:0% +through a or slip B we would lose the +resolution in space if the if the bundle + + align:start position:0% +resolution in space if the if the bundle + + + align:start position:0% +resolution in space if the if the bundle +of particles was too far spread out in + + align:start position:0% +of particles was too far spread out in + + + align:start position:0% +of particles was too far spread out in +the y direction so we have to contain or + + align:start position:0% +the y direction so we have to contain or + + + align:start position:0% +the y direction so we have to contain or +compress the distribution of test + + align:start position:0% +compress the distribution of test + + + align:start position:0% +compress the distribution of test +particles within a small region Delta y + + align:start position:0% +particles within a small region Delta y + + + align:start position:0% +particles within a small region Delta y +but that means they must have a + + align:start position:0% +but that means they must have a + + + align:start position:0% +but that means they must have a +correspondingly large uncertainty in the + + align:start position:0% +correspondingly large uncertainty in the + + + align:start position:0% +correspondingly large uncertainty in the +momentum + + align:start position:0% +momentum + + + align:start position:0% +momentum +because of the uncertainty principle and + + align:start position:0% +because of the uncertainty principle and + + + align:start position:0% +because of the uncertainty principle and +therefore there'll be a correspondingly + + align:start position:0% +therefore there'll be a correspondingly + + + align:start position:0% +therefore there'll be a correspondingly +large uncertainty in The Recoil momentum + + align:start position:0% +large uncertainty in The Recoil momentum + + + align:start position:0% +large uncertainty in The Recoil momentum +of the electron after scattering of + + align:start position:0% +of the electron after scattering of + + + align:start position:0% +of the electron after scattering of +exactly the right amount this part's + + align:start position:0% +exactly the right amount this part's + + + align:start position:0% +exactly the right amount this part's +kind of amazing of exactly the right + + align:start position:0% +kind of amazing of exactly the right + + + align:start position:0% +kind of amazing of exactly the right +amount needed to perfectly wash out + + align:start position:0% +amount needed to perfectly wash out + + + align:start position:0% +amount needed to perfectly wash out +those very clear interference fringes to + + align:start position:0% +those very clear interference fringes to + + + align:start position:0% +those very clear interference fringes to +get back to two bell-shaped curves and + + align:start position:0% +get back to two bell-shaped curves and + + + align:start position:0% +get back to two bell-shaped curves and +so that very uh regular very narrow + + align:start position:0% +so that very uh regular very narrow + + + align:start position:0% +so that very uh regular very narrow +peaks of the interference changes so + + align:start position:0% +peaks of the interference changes so + + + align:start position:0% +peaks of the interference changes so +it's literally the uncertainty principle + + align:start position:0% +it's literally the uncertainty principle + + + align:start position:0% +it's literally the uncertainty principle +that precludes + + align:start position:0% +that precludes + + + align:start position:0% +that precludes +being able to both measure through which + + align:start position:0% +being able to both measure through which + + + align:start position:0% +being able to both measure through which +slits an individual particle past and + + align:start position:0% +slits an individual particle past and + + + align:start position:0% +slits an individual particle past and +also retain these very clear uh features + + align:start position:0% +also retain these very clear uh features + + + align:start position:0% +also retain these very clear uh features +of the interference pattern that's + + align:start position:0% +of the interference pattern that's + + + align:start position:0% +of the interference pattern that's +pretty I think it's pretty amazing and + + align:start position:0% +pretty I think it's pretty amazing and + + + align:start position:0% +pretty I think it's pretty amazing and +very beautiful and it's only a couple + + align:start position:0% +very beautiful and it's only a couple + + + align:start position:0% +very beautiful and it's only a couple +lines of algebra to show so if that if + + align:start position:0% +lines of algebra to show so if that if + + + align:start position:0% +lines of algebra to show so if that if +even this most recent hand waving uh + + align:start position:0% +even this most recent hand waving uh + + + align:start position:0% +even this most recent hand waving uh +effort of mine is was too quick I + + align:start position:0% +effort of mine is was too quick I + + + align:start position:0% +effort of mine is was too quick I +encourage you to look at the lecture + + align:start position:0% +encourage you to look at the lecture + + + align:start position:0% +encourage you to look at the lecture +notes but that's the upshot + + align:start position:0% +notes but that's the upshot + + + align:start position:0% +notes but that's the upshot +so so what we really finding + + align:start position:0% +so so what we really finding + + + align:start position:0% +so so what we really finding +conceptually and this is what people + + align:start position:0% +conceptually and this is what people + + + align:start position:0% +conceptually and this is what people +began to kind of uh converge around by + + align:start position:0% +began to kind of uh converge around by + + + align:start position:0% +began to kind of uh converge around by +even by the late 1920s + + align:start position:0% +even by the late 1920s + + + align:start position:0% +even by the late 1920s +was if we ask a kind of particle-like + + align:start position:0% +was if we ask a kind of particle-like + + + align:start position:0% +was if we ask a kind of particle-like +question such as what was your path + + align:start position:0% +question such as what was your path + + + align:start position:0% +question such as what was your path +through which slit did an individual + + align:start position:0% +through which slit did an individual + + + align:start position:0% +through which slit did an individual +particle pass we will get a definite + + align:start position:0% +particle pass we will get a definite + + + align:start position:0% +particle pass we will get a definite +answer we'll get a particle-like answer + + align:start position:0% +answer we'll get a particle-like answer + + + align:start position:0% +answer we'll get a particle-like answer +each particle either went through a or + + align:start position:0% +each particle either went through a or + + + align:start position:0% +each particle either went through a or +wet through slip B with corresponding + + align:start position:0% +wet through slip B with corresponding + + + align:start position:0% +wet through slip B with corresponding +kind of particle-like Statistics it's + + align:start position:0% +kind of particle-like Statistics it's + + + align:start position:0% +kind of particle-like Statistics it's +all consistent we'll get a clear answer + + align:start position:0% +all consistent we'll get a clear answer + + + align:start position:0% +all consistent we'll get a clear answer +and the whole rest of the problem will + + align:start position:0% +and the whole rest of the problem will + + + align:start position:0% +and the whole rest of the problem will +be consistent with particle-like + + align:start position:0% +be consistent with particle-like + + + align:start position:0% +be consistent with particle-like +questions and answers + + align:start position:0% +questions and answers + + + align:start position:0% +questions and answers +on the other hand if we ask a wave-like + + align:start position:0% +on the other hand if we ask a wave-like + + + align:start position:0% +on the other hand if we ask a wave-like +question how does this wave function + + align:start position:0% +question how does this wave function + + + align:start position:0% +question how does this wave function +evolve in the in the region between the + + align:start position:0% +evolve in the in the region between the + + + align:start position:0% +evolve in the in the region between the +slits and the detector for example then + + align:start position:0% +slits and the detector for example then + + + align:start position:0% +slits and the detector for example then +we'll get a wave-like answer the way the + + align:start position:0% +we'll get a wave-like answer the way the + + + align:start position:0% +we'll get a wave-like answer the way the +probability amplitude is schroding a + + align:start position:0% +probability amplitude is schroding a + + + align:start position:0% +probability amplitude is schroding a +wave function will spread out in space + + align:start position:0% +wave function will spread out in space + + + align:start position:0% +wave function will spread out in space +and some regions they'll be constructive + + align:start position:0% +and some regions they'll be constructive + + + align:start position:0% +and some regions they'll be constructive +interference and the likelihood defined + + align:start position:0% +interference and the likelihood defined + + + align:start position:0% +interference and the likelihood defined +electron will be higher in other regions + + align:start position:0% +electron will be higher in other regions + + + align:start position:0% +electron will be higher in other regions +of space you'll get destructed + + align:start position:0% +of space you'll get destructed + + + align:start position:0% +of space you'll get destructed +interference because corresponding is + + align:start position:0% +interference because corresponding is + + + align:start position:0% +interference because corresponding is +lower likelihood for an electron to be + + align:start position:0% +lower likelihood for an electron to be + + + align:start position:0% +lower likelihood for an electron to be +found but we we only get wave-like + + align:start position:0% +found but we we only get wave-like + + + align:start position:0% +found but we we only get wave-like +answers when we ask wave-like questions + + align:start position:0% +answers when we ask wave-like questions + + + align:start position:0% +answers when we ask wave-like questions +so let me summarize and we'll have a few + + align:start position:0% +so let me summarize and we'll have a few + + + align:start position:0% +so let me summarize and we'll have a few +moments for some discussion and + + align:start position:0% +moments for some discussion and + + + align:start position:0% +moments for some discussion and +questions + + align:start position:0% +questions + + + align:start position:0% +questions +so in a really quite limited span of + + align:start position:0% +so in a really quite limited span of + + + align:start position:0% +so in a really quite limited span of +time really in less than a whole + + align:start position:0% +time really in less than a whole + + + align:start position:0% +time really in less than a whole +calendar year between spring of 1925 and + + align:start position:0% +calendar year between spring of 1925 and + + + align:start position:0% +calendar year between spring of 1925 and +spring of 1926 both Nano Heisenberg and + + align:start position:0% +spring of 1926 both Nano Heisenberg and + + + align:start position:0% +spring of 1926 both Nano Heisenberg and +separately Eric schreiker introduced + + align:start position:0% +separately Eric schreiker introduced + + + align:start position:0% +separately Eric schreiker introduced +whole new approaches to what they were + + align:start position:0% +whole new approaches to what they were + + + align:start position:0% +whole new approaches to what they were +seeking a kind of first principles + + align:start position:0% +seeking a kind of first principles + + + align:start position:0% +seeking a kind of first principles +theory of the quantum realm a quantum + + align:start position:0% +theory of the quantum realm a quantum + + + align:start position:0% +theory of the quantum realm a quantum +mechanics rather than this kind of grab + + align:start position:0% +mechanics rather than this kind of grab + + + align:start position:0% +mechanics rather than this kind of grab +bag of ad hoc Quantum conditions + + align:start position:0% +bag of ad hoc Quantum conditions + + + align:start position:0% +bag of ad hoc Quantum conditions +so you're looking for this quantitative + + align:start position:0% +so you're looking for this quantitative + + + align:start position:0% +so you're looking for this quantitative +description of the atomic realm that had + + align:start position:0% +description of the atomic realm that had + + + align:start position:0% +description of the atomic realm that had +certain Quantum ideas built in from the + + align:start position:0% +certain Quantum ideas built in from the + + + align:start position:0% +certain Quantum ideas built in from the +start discrete spectral lines from + + align:start position:0% +start discrete spectral lines from + + + align:start position:0% +start discrete spectral lines from +excited atoms debris wave matter waves + + align:start position:0% +excited atoms debris wave matter waves + + + align:start position:0% +excited atoms debris wave matter waves +and so on rather than kind of stapling + + align:start position:0% +and so on rather than kind of stapling + + + align:start position:0% +and so on rather than kind of stapling +these on at the end + + align:start position:0% +these on at the end + + + align:start position:0% +these on at the end +now these approaches looked quite + + align:start position:0% +now these approaches looked quite + + + align:start position:0% +now these approaches looked quite +different at first and even kind of not + + align:start position:0% +different at first and even kind of not + + + align:start position:0% +different at first and even kind of not +very encouraging to be polite about it + + align:start position:0% +very encouraging to be polite about it + + + align:start position:0% +very encouraging to be polite about it +to each other's inventors Heisenberg's + + align:start position:0% +to each other's inventors Heisenberg's + + + align:start position:0% +to each other's inventors Heisenberg's +approach really emphasized and built + + align:start position:0% +approach really emphasized and built + + + align:start position:0% +approach really emphasized and built +upon this what he considered a kind of + + align:start position:0% +upon this what he considered a kind of + + + align:start position:0% +upon this what he considered a kind of +inherent discreetness that was the main + + align:start position:0% +inherent discreetness that was the main + + + align:start position:0% +inherent discreetness that was the main +lesson of the quantum as far as + + align:start position:0% +lesson of the quantum as far as + + + align:start position:0% +lesson of the quantum as far as +Heisenberg was concerned Schrodinger in + + align:start position:0% +Heisenberg was concerned Schrodinger in + + + align:start position:0% +Heisenberg was concerned Schrodinger in +the meantime built separately on + + align:start position:0% +the meantime built separately on + + + align:start position:0% +the meantime built separately on +Deborah's suggestion the real lesson is + + align:start position:0% +Deborah's suggestion the real lesson is + + + align:start position:0% +Deborah's suggestion the real lesson is +is a surprise and continua that even + + align:start position:0% +is a surprise and continua that even + + + align:start position:0% +is a surprise and continua that even +solid matter like electrons have + + align:start position:0% +solid matter like electrons have + + + align:start position:0% +solid matter like electrons have +Associated wave-like Behavior they're + + align:start position:0% +Associated wave-like Behavior they're + + + align:start position:0% +Associated wave-like Behavior they're +building on different kind of conceptual + + align:start position:0% +building on different kind of conceptual + + + align:start position:0% +building on different kind of conceptual +building blocks and yet by the summer of + + align:start position:0% +building blocks and yet by the summer of + + + align:start position:0% +building blocks and yet by the summer of + + align:start position:0% + + + align:start position:0% +several physicists had had built this + + align:start position:0% +several physicists had had built this + + + align:start position:0% +several physicists had had built this +kind of mathematical map between these + + align:start position:0% +kind of mathematical map between these + + + align:start position:0% +kind of mathematical map between these +very very different looking approaches + + align:start position:0% +very very different looking approaches + + + align:start position:0% +very very different looking approaches +and even though there was now in + + align:start position:0% +and even though there was now in + + + align:start position:0% +and even though there was now in +arguably one internally consistent + + align:start position:0% +arguably one internally consistent + + + align:start position:0% +arguably one internally consistent +mathematical approach what it all meant + + align:start position:0% +mathematical approach what it all meant + + + align:start position:0% +mathematical approach what it all meant +about the world was as unclear then + + align:start position:0% +about the world was as unclear then + + + align:start position:0% +about the world was as unclear then +often as it remains even to this day + + align:start position:0% +often as it remains even to this day + + + align:start position:0% +often as it remains even to this day +uh so one question was what's this wave + + align:start position:0% +uh so one question was what's this wave + + + align:start position:0% +uh so one question was what's this wave +the wave function is now uh an object + + align:start position:0% +the wave function is now uh an object + + + align:start position:0% +the wave function is now uh an object +that can be manipulated using familiar + + align:start position:0% +that can be manipulated using familiar + + + align:start position:0% +that can be manipulated using familiar +techniques it's a differential equation + + align:start position:0% +techniques it's a differential equation + + + align:start position:0% +techniques it's a differential equation +we can understand the spectrum of + + align:start position:0% +we can understand the spectrum of + + + align:start position:0% +we can understand the spectrum of +allowable eigenvalues but what is it + + align:start position:0% +allowable eigenvalues but what is it + + + align:start position:0% +allowable eigenvalues but what is it +actually telling us about the world and + + align:start position:0% +actually telling us about the world and + + + align:start position:0% +actually telling us about the world and +with Max Bourne's suggestion in the + + align:start position:0% +with Max Bourne's suggestion in the + + + align:start position:0% +with Max Bourne's suggestion in the +summer of 1926 physicists pretty quickly + + align:start position:0% +summer of 1926 physicists pretty quickly + + + align:start position:0% +summer of 1926 physicists pretty quickly +came to the idea that the wave function + + align:start position:0% +came to the idea that the wave function + + + align:start position:0% +came to the idea that the wave function +is not telling us about the physical + + align:start position:0% +is not telling us about the physical + + + align:start position:0% +is not telling us about the physical +extent of an object in space but + + align:start position:0% +extent of an object in space but + + + align:start position:0% +extent of an object in space but +actually about the likelihood for events + + align:start position:0% +actually about the likelihood for events + + + align:start position:0% +actually about the likelihood for events +to happen and in particular this + + align:start position:0% +to happen and in particular this + + + align:start position:0% +to happen and in particular this +absolute square of this wave-like + + align:start position:0% +absolute square of this wave-like + + + align:start position:0% +absolute square of this wave-like +quantity should give us the probability + + align:start position:0% +quantity should give us the probability + + + align:start position:0% +quantity should give us the probability +quickly on the heels of that less than a + + align:start position:0% +quickly on the heels of that less than a + + + align:start position:0% +quickly on the heels of that less than a +whole year later by Spring of 27 + + align:start position:0% +whole year later by Spring of 27 + + + align:start position:0% +whole year later by Spring of 27 +Heisenberg had derived is now famous + + align:start position:0% +Heisenberg had derived is now famous + + + align:start position:0% +Heisenberg had derived is now famous +because certainly principle that there + + align:start position:0% +because certainly principle that there + + + align:start position:0% +because certainly principle that there +are these unavoidable trade-offs within + + align:start position:0% +are these unavoidable trade-offs within + + + align:start position:0% +are these unavoidable trade-offs within +in the Precision with which we could + + align:start position:0% +in the Precision with which we could + + + align:start position:0% +in the Precision with which we could +ever hope to specify characteristics of + + align:start position:0% +ever hope to specify characteristics of + + + align:start position:0% +ever hope to specify characteristics of +the kind of quantum realm a kind of + + align:start position:0% +the kind of quantum realm a kind of + + + align:start position:0% +the kind of quantum realm a kind of +pairwise trade-off where we could make + + align:start position:0% +pairwise trade-off where we could make + + + align:start position:0% +pairwise trade-off where we could make +one quantity really sharp but only at + + align:start position:0% +one quantity really sharp but only at + + + align:start position:0% +one quantity really sharp but only at +the expense of making some corresponding + + align:start position:0% +the expense of making some corresponding + + + align:start position:0% +the expense of making some corresponding +or complementary quantity uh very + + align:start position:0% +or complementary quantity uh very + + + align:start position:0% +or complementary quantity uh very +imprecise and the trade-off the Seesaw + + align:start position:0% +imprecise and the trade-off the Seesaw + + + align:start position:0% +imprecise and the trade-off the Seesaw +again uh being uh controlled by flank's + + align:start position:0% +again uh being uh controlled by flank's + + + align:start position:0% +again uh being uh controlled by flank's +constant and then these kinds of broader + + align:start position:0% +constant and then these kinds of broader + + + align:start position:0% +constant and then these kinds of broader +conceptual dualities like this wave + + align:start position:0% +conceptual dualities like this wave + + + align:start position:0% +conceptual dualities like this wave +particle duality we've seen now a few + + align:start position:0% +particle duality we've seen now a few + + + align:start position:0% +particle duality we've seen now a few +times the type of answer we could ever + + align:start position:0% +times the type of answer we could ever + + + align:start position:0% +times the type of answer we could ever +hope to find depends on the type of + + align:start position:0% +hope to find depends on the type of + + + align:start position:0% +hope to find depends on the type of +question we ask so it's not though that + + align:start position:0% +question we ask so it's not though that + + + align:start position:0% +question we ask so it's not though that +the electron really is a particle or a + + align:start position:0% +the electron really is a particle or a + + + align:start position:0% +the electron really is a particle or a +wave that it's a kind of contextual + + align:start position:0% +wave that it's a kind of contextual + + + align:start position:0% +wave that it's a kind of contextual +question + + align:start position:0% +question + + + align:start position:0% +question +though what kind of properties do we + + align:start position:0% +though what kind of properties do we + + + align:start position:0% +though what kind of properties do we +hope to investigate then we're going to + + align:start position:0% +hope to investigate then we're going to + + + align:start position:0% +hope to investigate then we're going to +foreclose some answers from ever even + + align:start position:0% +foreclose some answers from ever even + + + align:start position:0% +foreclose some answers from ever even +being possible even as we get other + + align:start position:0% +being possible even as we get other + + + align:start position:0% +being possible even as we get other +quite definite answers so Niels Bohr + + align:start position:0% +quite definite answers so Niels Bohr + + + align:start position:0% +quite definite answers so Niels Bohr +partly from his uh intense discussions + + align:start position:0% +partly from his uh intense discussions + + + align:start position:0% +partly from his uh intense discussions +with with Heisenberg with other + + align:start position:0% +with with Heisenberg with other + + + align:start position:0% +with with Heisenberg with other +colleagues he used that to enunciate a + + align:start position:0% +colleagues he used that to enunciate a + + + align:start position:0% +colleagues he used that to enunciate a +very general philosophy of the quantum + + align:start position:0% +very general philosophy of the quantum + + + align:start position:0% +very general philosophy of the quantum +Realm by uh September of 1927 right on + + align:start position:0% +Realm by uh September of 1927 right on + + + align:start position:0% +Realm by uh September of 1927 right on +the heels of this which he came to call + + align:start position:0% +the heels of this which he came to call + + + align:start position:0% +the heels of this which he came to call +complementary so it's not an either or + + align:start position:0% +complementary so it's not an either or + + + align:start position:0% +complementary so it's not an either or +world it's a both and that we are we are + + align:start position:0% +world it's a both and that we are we are + + + align:start position:0% +world it's a both and that we are we are +required in this case to draw on both + + align:start position:0% +required in this case to draw on both + + + align:start position:0% +required in this case to draw on both +ideas and actual mathematical techniques + + align:start position:0% +ideas and actual mathematical techniques + + + align:start position:0% +ideas and actual mathematical techniques +with which we characterize wave behavior + + align:start position:0% +with which we characterize wave behavior + + + align:start position:0% +with which we characterize wave behavior +and ideas and techniques with which we + + align:start position:0% +and ideas and techniques with which we + + + align:start position:0% +and ideas and techniques with which we +characterize particle Behavior they are + + align:start position:0% +characterize particle Behavior they are + + + align:start position:0% +characterize particle Behavior they are +mutually exclusive we literally can't + + align:start position:0% +mutually exclusive we literally can't + + + align:start position:0% +mutually exclusive we literally can't +use them at the same time and yet we + + align:start position:0% +use them at the same time and yet we + + + align:start position:0% +use them at the same time and yet we +need both a complete description + + align:start position:0% +need both a complete description + + + align:start position:0% +need both a complete description +requires both even though they don't fit + + align:start position:0% +requires both even though they don't fit + + + align:start position:0% +requires both even though they don't fit +together at once and that Tabor was the + + align:start position:0% +together at once and that Tabor was the + + + align:start position:0% +together at once and that Tabor was the +deepest meaning the deepest lesson of + + align:start position:0% +deepest meaning the deepest lesson of + + + align:start position:0% +deepest meaning the deepest lesson of +quantum theory not everyone agreed but + + align:start position:0% +quantum theory not everyone agreed but + + + align:start position:0% +quantum theory not everyone agreed but +that's where Bohr arrived by 1927. okay + + align:start position:0% +that's where Bohr arrived by 1927. okay + + + align:start position:0% +that's where Bohr arrived by 1927. okay +any questions on any of that + + align:start position:0% + + + + align:start position:0% + +that is so straightforward so boringly + + align:start position:0% +that is so straightforward so boringly + + + align:start position:0% +that is so straightforward so boringly +familiar + + align:start position:0% +familiar + + + align:start position:0% +familiar +but there's not even a single question + + align:start position:0% +but there's not even a single question + + + align:start position:0% +but there's not even a single question +to ask about the fundamental nature of + + align:start position:0% +to ask about the fundamental nature of + + + align:start position:0% +to ask about the fundamental nature of +reality + + align:start position:0% +reality + + + align:start position:0% +reality +boy holiday weekends + + align:start position:0% +boy holiday weekends + + + align:start position:0% +boy holiday weekends +no + + align:start position:0% + + + + align:start position:0% + +well + + align:start position:0% +well + + + align:start position:0% +well +if you'll if you'll permit me on + + align:start position:0% +if you'll if you'll permit me on + + + align:start position:0% +if you'll if you'll permit me on +tomorrow's class I'm going to try to + + align:start position:0% +tomorrow's class I'm going to try to + + + align:start position:0% +tomorrow's class I'm going to try to +shake your Quantum complacency even + + align:start position:0% +shake your Quantum complacency even + + + align:start position:0% +shake your Quantum complacency even +further so tomorrow we'll explore + + align:start position:0% +further so tomorrow we'll explore + + + align:start position:0% +further so tomorrow we'll explore +Quantum weirdness uh in in even more + + align:start position:0% +Quantum weirdness uh in in even more + + + align:start position:0% +Quantum weirdness uh in in even more +Direction so if this stuff is humdrum + + align:start position:0% +Direction so if this stuff is humdrum + + + align:start position:0% +Direction so if this stuff is humdrum +and familiar give me give me one more + + align:start position:0% +and familiar give me give me one more + + + align:start position:0% +and familiar give me give me one more +shot for tomorrow so Fisher asks for + + align:start position:0% +shot for tomorrow so Fisher asks for + + + align:start position:0% +shot for tomorrow so Fisher asks for +shorting his work more quickly except it + + align:start position:0% +shorting his work more quickly except it + + + align:start position:0% +shorting his work more quickly except it +because it was more basic in mechanics I + + align:start position:0% +because it was more basic in mechanics I + + + align:start position:0% +because it was more basic in mechanics I +think that's absolutely right Fisher uh + + align:start position:0% +think that's absolutely right Fisher uh + + + align:start position:0% +think that's absolutely right Fisher uh +and I think + + align:start position:0% +and I think + + + align:start position:0% +and I think +there was a kind of + + align:start position:0% +there was a kind of + + + align:start position:0% +there was a kind of +um people could could do stuff with it + + align:start position:0% +um people could could do stuff with it + + + align:start position:0% +um people could could do stuff with it +right so so even while the concepts were + + align:start position:0% +right so so even while the concepts were + + + align:start position:0% +right so so even while the concepts were +still very far from Clear what what is + + align:start position:0% +still very far from Clear what what is + + + align:start position:0% +still very far from Clear what what is +we for what's the wave function what is + + align:start position:0% +we for what's the wave function what is + + + align:start position:0% +we for what's the wave function what is +a wave of what is it telling us that was + + align:start position:0% +a wave of what is it telling us that was + + + align:start position:0% +a wave of what is it telling us that was +by no means clear and even after the + + align:start position:0% +by no means clear and even after the + + + align:start position:0% +by no means clear and even after the +answers that we would now recognize were + + align:start position:0% +answers that we would now recognize were + + + align:start position:0% +answers that we would now recognize were +put forward those weren't you know those + + align:start position:0% +put forward those weren't you know those + + + align:start position:0% +put forward those weren't you know those +didn't claim consensus right away and + + align:start position:0% +didn't claim consensus right away and + + + align:start position:0% +didn't claim consensus right away and +yet in between people can still do stuff + + align:start position:0% +yet in between people can still do stuff + + + align:start position:0% +yet in between people can still do stuff +right you could train PhD students to + + align:start position:0% +right you could train PhD students to + + + align:start position:0% +right you could train PhD students to +look at this or that specific question + + align:start position:0% +look at this or that specific question + + + align:start position:0% +look at this or that specific question +because the firm the apparatus the + + align:start position:0% +because the firm the apparatus the + + + align:start position:0% +because the firm the apparatus the +mathematical apparatus was already + + align:start position:0% +mathematical apparatus was already + + + align:start position:0% +mathematical apparatus was already +something that practiced you know since + + align:start position:0% +something that practiced you know since + + + align:start position:0% +something that practiced you know since +their youngest earliest studies so I + + align:start position:0% +their youngest earliest studies so I + + + align:start position:0% +their youngest earliest studies so I +think that really had a lot to do with + + align:start position:0% +think that really had a lot to do with + + + align:start position:0% +think that really had a lot to do with +with how rapidly Schrodinger's work was + + align:start position:0% +with how rapidly Schrodinger's work was + + + align:start position:0% +with how rapidly Schrodinger's work was +really welcomed + + align:start position:0% +really welcomed + + + align:start position:0% +really welcomed +um + + align:start position:0% +um + + + align:start position:0% +um +and that it helped obviously it helped a + + align:start position:0% +and that it helped obviously it helped a + + + align:start position:0% +and that it helped obviously it helped a +lot when Schrodinger and and uh Jordan + + align:start position:0% +lot when Schrodinger and and uh Jordan + + + align:start position:0% +lot when Schrodinger and and uh Jordan +and Dirac uh elucidated the kind of + + align:start position:0% +and Dirac uh elucidated the kind of + + + align:start position:0% +and Dirac uh elucidated the kind of +mathematical mapping so then it really + + align:start position:0% +mathematical mapping so then it really + + + align:start position:0% +mathematical mapping so then it really +became a question of convenience and not + + align:start position:0% +became a question of convenience and not + + + align:start position:0% +became a question of convenience and not +either or it's not like I had to vote + + align:start position:0% +either or it's not like I had to vote + + + align:start position:0% +either or it's not like I had to vote +for team Schrodinger versus Team + + align:start position:0% +for team Schrodinger versus Team + + + align:start position:0% +for team Schrodinger versus Team +Heisenberg now I could say oh this set + + align:start position:0% +Heisenberg now I could say oh this set + + + align:start position:0% +Heisenberg now I could say oh this set +of techniques is familiar to me I have + + align:start position:0% +of techniques is familiar to me I have + + + align:start position:0% +of techniques is familiar to me I have +lots of experience from classical + + align:start position:0% +lots of experience from classical + + + align:start position:0% +lots of experience from classical +mechanics or or Maxwell or whatever and + + align:start position:0% +mechanics or or Maxwell or whatever and + + + align:start position:0% +mechanics or or Maxwell or whatever and +so then it became a kind of um tool of + + align:start position:0% +so then it became a kind of um tool of + + + align:start position:0% +so then it became a kind of um tool of +choice and these tools were much more + + align:start position:0% +choice and these tools were much more + + + align:start position:0% +choice and these tools were much more +familiar to many more people at the time + + align:start position:0% +familiar to many more people at the time + + + align:start position:0% +familiar to many more people at the time +that's absolutely that absolutely played + + align:start position:0% +that's absolutely that absolutely played + + + align:start position:0% +that's absolutely that absolutely played +a role in in hastening um many people's + + align:start position:0% +a role in in hastening um many people's + + + align:start position:0% +a role in in hastening um many people's +attention to this stuff good good point + + align:start position:0% +attention to this stuff good good point + + + align:start position:0% +attention to this stuff good good point +uh Aiden asked is Heisman position + + align:start position:0% +uh Aiden asked is Heisman position + + + align:start position:0% +uh Aiden asked is Heisman position +principal kind of spiritual + + align:start position:0% +principal kind of spiritual + + + align:start position:0% +principal kind of spiritual +uh for some people yes although that + + align:start position:0% +uh for some people yes although that + + + align:start position:0% +uh for some people yes although that +gets uh there's a lot to say about that + + align:start position:0% +gets uh there's a lot to say about that + + + align:start position:0% +gets uh there's a lot to say about that +uh are there those who think a more + + align:start position:0% +uh are there those who think a more + + + align:start position:0% +uh are there those who think a more +literal analysis would be that we simply + + align:start position:0% +literal analysis would be that we simply + + + align:start position:0% +literal analysis would be that we simply +need to discover reform observation not + + align:start position:0% +need to discover reform observation not + + + align:start position:0% +need to discover reform observation not +involve test particles so so Aiden I + + align:start position:0% +involve test particles so so Aiden I + + + align:start position:0% +involve test particles so so Aiden I +thought you're going a different way + + align:start position:0% +thought you're going a different way + + + align:start position:0% +thought you're going a different way +first so one one topic which is + + align:start position:0% +first so one one topic which is + + + align:start position:0% +first so one one topic which is +I'll say controversial some people + + align:start position:0% +I'll say controversial some people + + + align:start position:0% +I'll say controversial some people +pursue what other people think it is + + align:start position:0% +pursue what other people think it is + + + align:start position:0% +pursue what other people think it is +full of holes + + align:start position:0% +full of holes + + + align:start position:0% +full of holes +one idea would be to say does the + + align:start position:0% +one idea would be to say does the + + + align:start position:0% +one idea would be to say does the +uncertainty principle give us a physical + + align:start position:0% +uncertainty principle give us a physical + + + align:start position:0% +uncertainty principle give us a physical +reason why there might be something like + + align:start position:0% +reason why there might be something like + + + align:start position:0% +reason why there might be something like +free will + + align:start position:0% +free will + + + align:start position:0% +free will +Consciousness and the experience of free + + align:start position:0% +Consciousness and the experience of free + + + align:start position:0% +Consciousness and the experience of free +will if + + align:start position:0% +will if + + + align:start position:0% +will if +you consume part of the concern going + + align:start position:0% +you consume part of the concern going + + + align:start position:0% +you consume part of the concern going +back to the A's the days of both uh + + align:start position:0% +back to the A's the days of both uh + + + align:start position:0% +back to the A's the days of both uh +Newton and and for that matter of + + align:start position:0% +Newton and and for that matter of + + + align:start position:0% +Newton and and for that matter of +Maxwell if if we live in a universe in + + align:start position:0% +Maxwell if if we live in a universe in + + + align:start position:0% +Maxwell if if we live in a universe in +which determinism holds + + align:start position:0% +which determinism holds + + + align:start position:0% +which determinism holds +perfectly if + + align:start position:0% +perfectly if + + + align:start position:0% +perfectly if +events in the future are uniquely + + align:start position:0% +events in the future are uniquely + + + align:start position:0% +events in the future are uniquely +determined by events in the past and and + + align:start position:0% +determined by events in the past and and + + + align:start position:0% +determined by events in the past and and +then we you know turn on our kind of + + align:start position:0% +then we you know turn on our kind of + + + align:start position:0% +then we you know turn on our kind of +sci-fi imaginations and imagine we're + + align:start position:0% +sci-fi imaginations and imagine we're + + + align:start position:0% +sci-fi imaginations and imagine we're +made of of matter + + align:start position:0% +made of of matter + + + align:start position:0% +made of of matter +atoms and and molecules if atoms and + + align:start position:0% +atoms and and molecules if atoms and + + + align:start position:0% +atoms and and molecules if atoms and +molecules + + align:start position:0% +molecules + + + align:start position:0% +molecules +um you know + + align:start position:0% +um you know + + + align:start position:0% +um you know +have to obey the laws of nature then in + + align:start position:0% +have to obey the laws of nature then in + + + align:start position:0% +have to obey the laws of nature then in +principle they're subject to determinism + + align:start position:0% +principle they're subject to determinism + + + align:start position:0% +principle they're subject to determinism +at least in a pre-quantum mechanical way + + align:start position:0% +at least in a pre-quantum mechanical way + + + align:start position:0% +at least in a pre-quantum mechanical way +then you know then aren't we all just + + align:start position:0% +then you know then aren't we all just + + + align:start position:0% +then you know then aren't we all just +pre-programmed or we merely machines uh + + align:start position:0% +pre-programmed or we merely machines uh + + + align:start position:0% +pre-programmed or we merely machines uh +with no more free will than comets who + + align:start position:0% +with no more free will than comets who + + + align:start position:0% +with no more free will than comets who +can't help but follow a keplerian orbit + + align:start position:0% +can't help but follow a keplerian orbit + + + align:start position:0% +can't help but follow a keplerian orbit +as they orbit the Sun and believe it or + + align:start position:0% +as they orbit the Sun and believe it or + + + align:start position:0% +as they orbit the Sun and believe it or +not that was a debate that got people + + align:start position:0% +not that was a debate that got people + + + align:start position:0% +not that was a debate that got people +very + + align:start position:0% +very + + + align:start position:0% +very +excited and exercised and mad at each + + align:start position:0% +excited and exercised and mad at each + + + align:start position:0% +excited and exercised and mad at each +other for a long long time and so there + + align:start position:0% +other for a long long time and so there + + + align:start position:0% +other for a long long time and so there +was some thought by some people early on + + align:start position:0% +was some thought by some people early on + + + align:start position:0% +was some thought by some people early on +starting really in the 1920s and 30s + + align:start position:0% +starting really in the 1920s and 30s + + + align:start position:0% +starting really in the 1920s and 30s +that maybe the uncertainty principle by + + align:start position:0% +that maybe the uncertainty principle by + + + align:start position:0% +that maybe the uncertainty principle by +breaking the kind of iron hold of + + align:start position:0% +breaking the kind of iron hold of + + + align:start position:0% +breaking the kind of iron hold of +determinism leaves a kind of space + + align:start position:0% +determinism leaves a kind of space + + + align:start position:0% +determinism leaves a kind of space +within our scientific theorizing for + + align:start position:0% +within our scientific theorizing for + + + align:start position:0% +within our scientific theorizing for +things that seemed or one or at least + + align:start position:0% +things that seemed or one or at least + + + align:start position:0% +things that seemed or one or at least +some might have hoped were not you know + + align:start position:0% +some might have hoped were not you know + + + align:start position:0% +some might have hoped were not you know +fully uniquely determined whether that's + + align:start position:0% +fully uniquely determined whether that's + + + align:start position:0% +fully uniquely determined whether that's +our own sense of individuality where the + + align:start position:0% +our own sense of individuality where the + + + align:start position:0% +our own sense of individuality where the +course of human events and liberality + + align:start position:0% +course of human events and liberality + + + align:start position:0% +course of human events and liberality +and so on + + align:start position:0% +and so on + + + align:start position:0% +and so on +now that gets a little a little tricky + + align:start position:0% +now that gets a little a little tricky + + + align:start position:0% +now that gets a little a little tricky +because unfortunately the uncertain + + align:start position:0% +because unfortunately the uncertain + + + align:start position:0% +because unfortunately the uncertain +critical argues at least most physicists + + align:start position:0% +critical argues at least most physicists + + + align:start position:0% +critical argues at least most physicists +would say the upside of the uncertainty + + align:start position:0% +would say the upside of the uncertainty + + + align:start position:0% +would say the upside of the uncertainty +principle is that everything's random + + align:start position:0% +principle is that everything's random + + + align:start position:0% +principle is that everything's random +that's and that's not quite how my + + align:start position:0% +that's and that's not quite how my + + + align:start position:0% +that's and that's not quite how my +thoughts feel well actually before the + + align:start position:0% +thoughts feel well actually before the + + + align:start position:0% +thoughts feel well actually before the +covid-19 my thoughts didn't always feel + + align:start position:0% +covid-19 my thoughts didn't always feel + + + align:start position:0% +covid-19 my thoughts didn't always feel +only random now they did but I mean so + + align:start position:0% +only random now they did but I mean so + + + align:start position:0% +only random now they did but I mean so +appealing to the certain principle + + align:start position:0% +appealing to the certain principle + + + align:start position:0% +appealing to the certain principle +breaks the hold of determinism but what + + align:start position:0% +breaks the hold of determinism but what + + + align:start position:0% +breaks the hold of determinism but what +it seems good in its place is random + + align:start position:0% +it seems good in its place is random + + + align:start position:0% +it seems good in its place is random +mush as opposed to something that + + align:start position:0% +mush as opposed to something that + + + align:start position:0% +mush as opposed to something that +otherwise might answer to the kind of + + align:start position:0% +otherwise might answer to the kind of + + + align:start position:0% +otherwise might answer to the kind of +lived experience or phenomena of + + align:start position:0% +lived experience or phenomena of + + + align:start position:0% +lived experience or phenomena of +something like Free Will so it's not + + align:start position:0% +something like Free Will so it's not + + + align:start position:0% +something like Free Will so it's not +like that's a single answer that that's + + align:start position:0% +like that's a single answer that that's + + + align:start position:0% +like that's a single answer that that's +done but that opens a space for kind of + + align:start position:0% +done but that opens a space for kind of + + + align:start position:0% +done but that opens a space for kind of +theorizing uh that goes on to this day + + align:start position:0% +theorizing uh that goes on to this day + + + align:start position:0% +theorizing uh that goes on to this day +um sometimes on the margins of both kind + + align:start position:0% +um sometimes on the margins of both kind + + + align:start position:0% +um sometimes on the margins of both kind +of physics and also of areas like + + align:start position:0% +of physics and also of areas like + + + align:start position:0% +of physics and also of areas like +neuroscience and philosophy but at least + + align:start position:0% +neuroscience and philosophy but at least + + + align:start position:0% +neuroscience and philosophy but at least +it opens up a different way of asking + + align:start position:0% +it opens up a different way of asking + + + align:start position:0% +it opens up a different way of asking +legitimate hard questions with some new + + align:start position:0% +legitimate hard questions with some new + + + align:start position:0% +legitimate hard questions with some new +conceptual inputs let me put it that way + + align:start position:0% +conceptual inputs let me put it that way + + + align:start position:0% +conceptual inputs let me put it that way +so even though I don't think people have + + align:start position:0% +so even though I don't think people have + + + align:start position:0% +so even though I don't think people have +found that answer yet it's interesting + + align:start position:0% +found that answer yet it's interesting + + + align:start position:0% +found that answer yet it's interesting +that that opens a space to ask old + + align:start position:0% +that that opens a space to ask old + + + align:start position:0% +that that opens a space to ask old +questions maybe in some new ways + + align:start position:0% +questions maybe in some new ways + + + align:start position:0% +questions maybe in some new ways +um I wrote a book a couple years ago + + align:start position:0% +um I wrote a book a couple years ago + + + align:start position:0% +um I wrote a book a couple years ago +called how the hippies saved physics + + align:start position:0% +called how the hippies saved physics + + + align:start position:0% +called how the hippies saved physics +it's very obnoxious title where people + + align:start position:0% +it's very obnoxious title where people + + + align:start position:0% +it's very obnoxious title where people +thought maybe there were other kind of + + align:start position:0% +thought maybe there were other kind of + + + align:start position:0% +thought maybe there were other kind of +unexplained or unaccounted for phenomena + + align:start position:0% +unexplained or unaccounted for phenomena + + + align:start position:0% +unexplained or unaccounted for phenomena +that quantum theory might be able to + + align:start position:0% +that quantum theory might be able to + + + align:start position:0% +that quantum theory might be able to +account for like um claims of ESP or + + align:start position:0% +account for like um claims of ESP or + + + align:start position:0% +account for like um claims of ESP or +other so-called occult phenomena mind + + align:start position:0% +other so-called occult phenomena mind + + + align:start position:0% +other so-called occult phenomena mind +reading for example and again I don't + + align:start position:0% +reading for example and again I don't + + + align:start position:0% +reading for example and again I don't +think they explained that at all but it + + align:start position:0% +think they explained that at all but it + + + align:start position:0% +think they explained that at all but it +was a way of trying to reason about + + align:start position:0% +was a way of trying to reason about + + + align:start position:0% +was a way of trying to reason about +strange or unexpected human scaled + + align:start position:0% +strange or unexpected human scaled + + + align:start position:0% +strange or unexpected human scaled +phenomena using a new set of tools that + + align:start position:0% +phenomena using a new set of tools that + + + align:start position:0% +phenomena using a new set of tools that +really weren't going to go away like the + + align:start position:0% +really weren't going to go away like the + + + align:start position:0% +really weren't going to go away like the +uncertain principle or like things we'll + + align:start position:0% +uncertain principle or like things we'll + + + align:start position:0% +uncertain principle or like things we'll +talk about in tomorrow's class things + + align:start position:0% +talk about in tomorrow's class things + + + align:start position:0% +talk about in tomorrow's class things +like quantum entanglement so I'm not + + align:start position:0% +like quantum entanglement so I'm not + + + align:start position:0% +like quantum entanglement so I'm not +telling you that's the answer I'm + + align:start position:0% +telling you that's the answer I'm + + + align:start position:0% +telling you that's the answer I'm +telling you that opened up a space for + + align:start position:0% +telling you that opened up a space for + + + align:start position:0% +telling you that opened up a space for +people to ask + + align:start position:0% +people to ask + + + align:start position:0% +people to ask +either familiar questions from + + align:start position:0% +either familiar questions from + + + align:start position:0% +either familiar questions from +unfamiliar perspectives or sometimes ask + + align:start position:0% +unfamiliar perspectives or sometimes ask + + + align:start position:0% +unfamiliar perspectives or sometimes ask +new kinds of questions so in that sense + + align:start position:0% +new kinds of questions so in that sense + + + align:start position:0% +new kinds of questions so in that sense +what's the ultimate meaning of the + + align:start position:0% +what's the ultimate meaning of the + + + align:start position:0% +what's the ultimate meaning of the +uncertainties well I don't know when + + align:start position:0% +uncertainties well I don't know when + + + align:start position:0% +uncertainties well I don't know when +frankly I don't think anyone knows or at + + align:start position:0% +frankly I don't think anyone knows or at + + + align:start position:0% +frankly I don't think anyone knows or at +least it's still a subject of really + + align:start position:0% +least it's still a subject of really + + + align:start position:0% +least it's still a subject of really +robust debate like that Quantum to + + align:start position:0% +robust debate like that Quantum to + + + align:start position:0% +robust debate like that Quantum to +classical transition + + align:start position:0% +classical transition + + + align:start position:0% +classical transition +and I think it's fantastic that we have + + align:start position:0% +and I think it's fantastic that we have + + + align:start position:0% +and I think it's fantastic that we have +tools to even pose as questions now so I + + align:start position:0% +tools to even pose as questions now so I + + + align:start position:0% +tools to even pose as questions now so I +get excited by the nature of the + + align:start position:0% +get excited by the nature of the + + + align:start position:0% +get excited by the nature of the +question rather than having a favorite + + align:start position:0% +question rather than having a favorite + + + align:start position:0% +question rather than having a favorite +answer that's my own that's just me kind + + align:start position:0% +answer that's my own that's just me kind + + + align:start position:0% +answer that's my own that's just me kind +of proselytizing so Richard asks once + + align:start position:0% +of proselytizing so Richard asks once + + + align:start position:0% +of proselytizing so Richard asks once +General activity was wide they accepted + + align:start position:0% +General activity was wide they accepted + + + align:start position:0% +General activity was wide they accepted +where people already ringing alarm Bells + + align:start position:0% +where people already ringing alarm Bells + + + align:start position:0% +where people already ringing alarm Bells +about the conflicts being generated yes + + align:start position:0% +about the conflicts being generated yes + + + align:start position:0% +about the conflicts being generated yes +yes they were including uh Albert + + align:start position:0% +yes they were including uh Albert + + + align:start position:0% +yes they were including uh Albert +Einstein himself who had a few opinions + + align:start position:0% +Einstein himself who had a few opinions + + + align:start position:0% +Einstein himself who had a few opinions +on the matter uh and so + + align:start position:0% +on the matter uh and so + + + align:start position:0% +on the matter uh and so +it just goes back in large project + + align:start position:0% +it just goes back in large project + + + align:start position:0% +it just goes back in large project +things like um the the fall of the + + align:start position:0% +things like um the the fall of the + + + align:start position:0% +things like um the the fall of the +determinism and we'll come to actually + + align:start position:0% +determinism and we'll come to actually + + + align:start position:0% +determinism and we'll come to actually +some of these examples even in + + align:start position:0% +some of these examples even in + + + align:start position:0% +some of these examples even in +tomorrow's class so we'll come to some + + align:start position:0% +tomorrow's class so we'll come to some + + + align:start position:0% +tomorrow's class so we'll come to some +of Einstein's most enduring critiques of + + align:start position:0% +of Einstein's most enduring critiques of + + + align:start position:0% +of Einstein's most enduring critiques of +quantum theory in the light of us + + align:start position:0% +quantum theory in the light of us + + + align:start position:0% +quantum theory in the light of us +thinking about things like relativity uh + + align:start position:0% +thinking about things like relativity uh + + + align:start position:0% +thinking about things like relativity uh +tomorrow so partly I'll just bracket + + align:start position:0% +tomorrow so partly I'll just bracket + + + align:start position:0% +tomorrow so partly I'll just bracket +that and I'll just simply say yes it's a + + align:start position:0% +that and I'll just simply say yes it's a + + + align:start position:0% +that and I'll just simply say yes it's a +great question we'll see some examples + + align:start position:0% +great question we'll see some examples + + + align:start position:0% +great question we'll see some examples +tomorrow we can talk more + + align:start position:0% +tomorrow we can talk more + + + align:start position:0% +tomorrow we can talk more +um + + align:start position:0% +um + + + align:start position:0% +um +uh Lulu asked how's my mental emotional + + align:start position:0% +uh Lulu asked how's my mental emotional + + + align:start position:0% +uh Lulu asked how's my mental emotional +state I think you can see I'm still + + align:start position:0% +state I think you can see I'm still + + + align:start position:0% +state I think you can see I'm still +agitated I love this stuff uh and and + + align:start position:0% +agitated I love this stuff uh and and + + + align:start position:0% +agitated I love this stuff uh and and +tomorrow I won't be able to contain + + align:start position:0% +tomorrow I won't be able to contain + + + align:start position:0% +tomorrow I won't be able to contain +myself I'll talk about some of my own + + align:start position:0% +myself I'll talk about some of my own + + + align:start position:0% +myself I'll talk about some of my own +groups research and the foundations of + + align:start position:0% +groups research and the foundations of + + + align:start position:0% +groups research and the foundations of +quantum mechanics + + align:start position:0% +quantum mechanics + + + align:start position:0% +quantum mechanics +so good I mean not the research is so + + align:start position:0% +so good I mean not the research is so + + + align:start position:0% +so good I mean not the research is so +good the question's so good okay Aiden + + align:start position:0% +good the question's so good okay Aiden + + + align:start position:0% +good the question's so good okay Aiden +says uh does Heisman mean there's + + align:start position:0% +says uh does Heisman mean there's + + + align:start position:0% +says uh does Heisman mean there's +neither people Norwich right so so what + + align:start position:0% +neither people Norwich right so so what + + + align:start position:0% +neither people Norwich right so so what +we can do is recognize that now as a + + align:start position:0% +we can do is recognize that now as a + + + align:start position:0% +we can do is recognize that now as a +question with which we need as a + + align:start position:0% +question with which we need as a + + + align:start position:0% +question with which we need as a +community now have new tools to try to + + align:start position:0% +community now have new tools to try to + + + align:start position:0% +community now have new tools to try to +puzzle through our answers I'll put it + + align:start position:0% +puzzle through our answers I'll put it + + + align:start position:0% +puzzle through our answers I'll put it +that way + + align:start position:0% +that way + + + align:start position:0% +that way +um I mean one of the things that happens + + align:start position:0% +um I mean one of the things that happens + + + align:start position:0% +um I mean one of the things that happens +is uh people try to explain certain uh + + align:start position:0% +is uh people try to explain certain uh + + + align:start position:0% +is uh people try to explain certain uh +esoteric features of Consciousness using + + align:start position:0% +esoteric features of Consciousness using + + + align:start position:0% +esoteric features of Consciousness using +quantum theory but then it turns out + + align:start position:0% +quantum theory but then it turns out + + + align:start position:0% +quantum theory but then it turns out +that human brains are uh dense hot and + + align:start position:0% +that human brains are uh dense hot and + + + align:start position:0% +that human brains are uh dense hot and +wet and a lot of these Quantum effects + + align:start position:0% +wet and a lot of these Quantum effects + + + align:start position:0% +wet and a lot of these Quantum effects +work really well when we're near vacuum + + align:start position:0% +work really well when we're near vacuum + + + align:start position:0% +work really well when we're near vacuum +at low temperatures and you know like + + align:start position:0% +at low temperatures and you know like + + + align:start position:0% +at low temperatures and you know like +super dry so even though some things + + align:start position:0% +super dry so even though some things + + + align:start position:0% +super dry so even though some things +could happen in principle among Quantum + + align:start position:0% +could happen in principle among Quantum + + + align:start position:0% +could happen in principle among Quantum +objects having to maintain a kind of + + align:start position:0% +objects having to maintain a kind of + + + align:start position:0% +objects having to maintain a kind of +inherent quantumness is really hard in + + align:start position:0% +inherent quantumness is really hard in + + + align:start position:0% +inherent quantumness is really hard in +an environment like the human brain so + + align:start position:0% +an environment like the human brain so + + + align:start position:0% +an environment like the human brain so +again that launches new kinds of + + align:start position:0% +again that launches new kinds of + + + align:start position:0% +again that launches new kinds of +questions and investigations rather than + + align:start position:0% +questions and investigations rather than + + + align:start position:0% +questions and investigations rather than +again than saying oh we've solved so + + align:start position:0% +again than saying oh we've solved so + + + align:start position:0% +again than saying oh we've solved so +those things become really interesting + + align:start position:0% +those things become really interesting + + + align:start position:0% +those things become really interesting +and lots of smart people ask a hard + + align:start position:0% +and lots of smart people ask a hard + + + align:start position:0% +and lots of smart people ask a hard +question about them around the world + + align:start position:0% +question about them around the world + + + align:start position:0% +question about them around the world +because we have this new injection of + + align:start position:0% +because we have this new injection of + + + align:start position:0% +because we have this new injection of +kind of new conceptual things uh to + + align:start position:0% +kind of new conceptual things uh to + + + align:start position:0% +kind of new conceptual things uh to +really wonder about let me pause there I + + align:start position:0% +really wonder about let me pause there I + + + align:start position:0% +really wonder about let me pause there I +don't want to run too long uh remember + + align:start position:0% +don't want to run too long uh remember + + + align:start position:0% +don't want to run too long uh remember +we have class tomorrow twice in uh in a + + align:start position:0% +we have class tomorrow twice in uh in a + + + align:start position:0% +we have class tomorrow twice in uh in a +row this week uh we're back at our + + align:start position:0% +row this week uh we're back at our + + + align:start position:0% +row this week uh we're back at our +ordinary Zoom link you can find it + + align:start position:0% +ordinary Zoom link you can find it + + + align:start position:0% +ordinary Zoom link you can find it +through canvas and so tomorrow we'll sit + + align:start position:0% +through canvas and so tomorrow we'll sit + + + align:start position:0% +through canvas and so tomorrow we'll sit +a little bit longer with some of these + + align:start position:0% +a little bit longer with some of these + + + align:start position:0% +a little bit longer with some of these +uh weird and wacky Quantum phenomena + + align:start position:0% +uh weird and wacky Quantum phenomena + + + align:start position:0% +uh weird and wacky Quantum phenomena +so stay well see you tomorrow talk to + + align:start position:0% +so stay well see you tomorrow talk to + + + align:start position:0% +so stay well see you tomorrow talk to +you soon \ No newline at end of file diff --git a/gZ9DWdzGNqQ.txt b/gZ9DWdzGNqQ.txt new file mode 100644 index 0000000000000000000000000000000000000000..64aaaeb18e17172b165dec2e966b160b36846ec7 --- /dev/null +++ b/gZ9DWdzGNqQ.txt @@ -0,0 +1,1219 @@ +align:start position:0% + +in this case study we're going to see + + align:start position:0% +in this case study we're going to see + + + align:start position:0% +in this case study we're going to see +how we can create a photo illustration + + align:start position:0% +how we can create a photo illustration + + + align:start position:0% +how we can create a photo illustration +of your work the idea here is to show + + align:start position:0% +of your work the idea here is to show + + + align:start position:0% +of your work the idea here is to show +how a liquid battery works for a final + + align:start position:0% +how a liquid battery works for a final + + + align:start position:0% +how a liquid battery works for a final +illustration so first create + + align:start position:0% +illustration so first create + + + align:start position:0% +illustration so first create +photographic bits and pieces and put + + align:start position:0% +photographic bits and pieces and put + + + align:start position:0% +photographic bits and pieces and put +them all together think of it just as if + + align:start position:0% +them all together think of it just as if + + + align:start position:0% +them all together think of it just as if +you were drawing the pieces and putting + + align:start position:0% +you were drawing the pieces and putting + + + align:start position:0% +you were drawing the pieces and putting +those sketches together after I met with + + align:start position:0% +those sketches together after I met with + + + align:start position:0% +those sketches together after I met with +the researchers for a brainstorming + + align:start position:0% +the researchers for a brainstorming + + + align:start position:0% +the researchers for a brainstorming +meeting I got all of this material from + + align:start position:0% +meeting I got all of this material from + + + align:start position:0% +meeting I got all of this material from +them including a diagram that described + + align:start position:0% +them including a diagram that described + + + align:start position:0% +them including a diagram that described +my idea to create a model of how a + + align:start position:0% +my idea to create a model of how a + + + align:start position:0% +my idea to create a model of how a +liquid battery works this is the way I + + align:start position:0% +liquid battery works this is the way I + + + align:start position:0% +liquid battery works this is the way I +imagined the shoot to go okay first I + + align:start position:0% +imagined the shoot to go okay first I + + + align:start position:0% +imagined the shoot to go okay first I +would take an optical quality cuvette + + align:start position:0% +would take an optical quality cuvette + + + align:start position:0% +would take an optical quality cuvette +and would then pour the mercury and the + + align:start position:0% +and would then pour the mercury and the + + + align:start position:0% +and would then pour the mercury and the +water into the cuvette and somehow + + align:start position:0% +water into the cuvette and somehow + + + align:start position:0% +water into the cuvette and somehow +suspending with a clamp a strip of metal + + align:start position:0% +suspending with a clamp a strip of metal + + + align:start position:0% +suspending with a clamp a strip of metal +foam which is an important part of the + + align:start position:0% +foam which is an important part of the + + + align:start position:0% +foam which is an important part of the +science and because I was imagining a + + align:start position:0% +science and because I was imagining a + + + align:start position:0% +science and because I was imagining a +full container of this material after + + align:start position:0% +full container of this material after + + + align:start position:0% +full container of this material after +making the image I would then crop out + + align:start position:0% +making the image I would then crop out + + + align:start position:0% +making the image I would then crop out +the right side we don't need to see the + + align:start position:0% +the right side we don't need to see the + + + align:start position:0% +the right side we don't need to see the +clamping device and then flip the left + + align:start position:0% +clamping device and then flip the left + + + align:start position:0% +clamping device and then flip the left +side or a small portion of the left side + + align:start position:0% +side or a small portion of the left side + + + align:start position:0% +side or a small portion of the left side +over to the right to then make the full + + align:start position:0% +over to the right to then make the full + + + align:start position:0% +over to the right to then make the full +container and the final model now + + align:start position:0% +container and the final model now + + + align:start position:0% +container and the final model now +remember this is not a documentary image + + align:start position:0% +remember this is not a documentary image + + + align:start position:0% +remember this is not a documentary image +this is a photo illustration for + + align:start position:0% +this is a photo illustration for + + + align:start position:0% +this is a photo illustration for +hopefully a cover submission that's the + + align:start position:0% +hopefully a cover submission that's the + + + align:start position:0% +hopefully a cover submission that's the +idea okay so first I start looking at + + align:start position:0% +idea okay so first I start looking at + + + align:start position:0% +idea okay so first I start looking at +the cuvette the vessel into which I was + + align:start position:0% +the cuvette the vessel into which I was + + + align:start position:0% +the cuvette the vessel into which I was +going to be inserting and pouring all + + align:start position:0% +going to be inserting and pouring all + + + align:start position:0% +going to be inserting and pouring all +the components I put it on a lightbox + + align:start position:0% +the components I put it on a lightbox + + + align:start position:0% +the components I put it on a lightbox +and liked what I saw the picture was + + align:start position:0% +and liked what I saw the picture was + + + align:start position:0% +and liked what I saw the picture was +going to be simple and licked fairly + + align:start position:0% +going to be simple and licked fairly + + + align:start position:0% +going to be simple and licked fairly +well then I practiced inserting the + + align:start position:0% +well then I practiced inserting the + + + align:start position:0% +well then I practiced inserting the +metal foam with a clamping apparatus to + + align:start position:0% +metal foam with a clamping apparatus to + + + align:start position:0% +metal foam with a clamping apparatus to +see if it was doable and it was at least + + align:start position:0% +see if it was doable and it was at least + + + align:start position:0% +see if it was doable and it was at least +with an empty container sort of dry run + + align:start position:0% +with an empty container sort of dry run + + + align:start position:0% +with an empty container sort of dry run +so to speak so the next photograph I + + align:start position:0% +so to speak so the next photograph I + + + align:start position:0% +so to speak so the next photograph I +took was with the Mercury and water in + + align:start position:0% +took was with the Mercury and water in + + + align:start position:0% +took was with the Mercury and water in +the container which looked fine too + + align:start position:0% +the container which looked fine too + + + align:start position:0% +the container which looked fine too +I then discarded that by the way into + + align:start position:0% +I then discarded that by the way into + + + align:start position:0% +I then discarded that by the way into +special container the researchers + + align:start position:0% +special container the researchers + + + align:start position:0% +special container the researchers +provided and sort of started all over + + align:start position:0% +provided and sort of started all over + + + align:start position:0% +provided and sort of started all over +again + + align:start position:0% +again + + + align:start position:0% +again +and tried for the next steps which was + + align:start position:0% +and tried for the next steps which was + + + align:start position:0% +and tried for the next steps which was +going to be inserting the foam at a + + align:start position:0% +going to be inserting the foam at a + + + align:start position:0% +going to be inserting the foam at a +certain level with the water I played a + + align:start position:0% +certain level with the water I played a + + + align:start position:0% +certain level with the water I played a +little with lighting by shining a + + align:start position:0% +little with lighting by shining a + + + align:start position:0% +little with lighting by shining a +tungsten lamp on to it it gave a warmer + + align:start position:0% +tungsten lamp on to it it gave a warmer + + + align:start position:0% +tungsten lamp on to it it gave a warmer +feel which I liked then I plopped it + + align:start position:0% +feel which I liked then I plopped it + + + align:start position:0% +feel which I liked then I plopped it +further into the water to see how that + + align:start position:0% +further into the water to see how that + + + align:start position:0% +further into the water to see how that +was going to look and again I changed + + align:start position:0% +was going to look and again I changed + + + align:start position:0% +was going to look and again I changed +the lighting by adding a little lamp + + align:start position:0% +the lighting by adding a little lamp + + + align:start position:0% +the lighting by adding a little lamp +light onto this material so I was + + align:start position:0% +light onto this material so I was + + + align:start position:0% +light onto this material so I was +getting there + + align:start position:0% +getting there + + + align:start position:0% +getting there +eventually this is the image that I + + align:start position:0% +eventually this is the image that I + + + align:start position:0% +eventually this is the image that I +wound up with well sort of wound up with + + align:start position:0% +wound up with well sort of wound up with + + + align:start position:0% +wound up with well sort of wound up with +and I'll tell you frankly I was a bit + + align:start position:0% +and I'll tell you frankly I was a bit + + + align:start position:0% +and I'll tell you frankly I was a bit +nervous dealing with the mercury and + + align:start position:0% +nervous dealing with the mercury and + + + align:start position:0% +nervous dealing with the mercury and +pouring it out and dealing with that and + + align:start position:0% +pouring it out and dealing with that and + + + align:start position:0% +pouring it out and dealing with that and +the water especially while having the + + align:start position:0% +the water especially while having the + + + align:start position:0% +the water especially while having the +important cautionary instructions always + + align:start position:0% +important cautionary instructions always + + + align:start position:0% +important cautionary instructions always +sitting in front of me so again making + + align:start position:0% +sitting in front of me so again making + + + align:start position:0% +sitting in front of me so again making +the pieces photographically and then + + align:start position:0% +the pieces photographically and then + + + align:start position:0% +the pieces photographically and then +putting them together was the way to go + + align:start position:0% +putting them together was the way to go + + + align:start position:0% +putting them together was the way to go +remember this is an illustration using + + align:start position:0% +remember this is an illustration using + + + align:start position:0% +remember this is an illustration using +photographs for the purpose of creating + + align:start position:0% +photographs for the purpose of creating + + + align:start position:0% +photographs for the purpose of creating +a model of the technique of how a liquid + + align:start position:0% +a model of the technique of how a liquid + + + align:start position:0% +a model of the technique of how a liquid +battery works and this is how I did it + + align:start position:0% +battery works and this is how I did it + + + align:start position:0% +battery works and this is how I did it +I'm using Photoshop here but you can use + + align:start position:0% +I'm using Photoshop here but you can use + + + align:start position:0% +I'm using Photoshop here but you can use +other software of course and take a look + + align:start position:0% +other software of course and take a look + + + align:start position:0% +other software of course and take a look +at the real-life part of this where + + align:start position:0% +at the real-life part of this where + + + align:start position:0% +at the real-life part of this where +we're using one images for the receiver + + align:start position:0% +we're using one images for the receiver + + + align:start position:0% +we're using one images for the receiver +of the piece on the right side which is + + align:start position:0% +of the piece on the right side which is + + + align:start position:0% +of the piece on the right side which is +what we had been talking about so I'm + + align:start position:0% +what we had been talking about so I'm + + + align:start position:0% +what we had been talking about so I'm +first going to select the right side + + align:start position:0% +first going to select the right side + + + align:start position:0% +first going to select the right side +copy and paste into the image on the + + align:start position:0% +copy and paste into the image on the + + + align:start position:0% +copy and paste into the image on the +left side the container with all the + + align:start position:0% +left side the container with all the + + + align:start position:0% +left side the container with all the +material move it around a little bit see + + align:start position:0% +material move it around a little bit see + + + align:start position:0% +material move it around a little bit see +if it has the potential of being doable + + align:start position:0% +if it has the potential of being doable + + + align:start position:0% +if it has the potential of being doable +it's not bad I think when it's flattened + + align:start position:0% +it's not bad I think when it's flattened + + + align:start position:0% +it's not bad I think when it's flattened +it'll look better I think it can work so + + align:start position:0% +it'll look better I think it can work so + + + align:start position:0% +it'll look better I think it can work so +I will in fact flatten the image and if + + align:start position:0% +I will in fact flatten the image and if + + + align:start position:0% +I will in fact flatten the image and if +you remember we were going to crop out + + align:start position:0% +you remember we were going to crop out + + + align:start position:0% +you remember we were going to crop out +the right side which is what we're going + + align:start position:0% +the right side which is what we're going + + + align:start position:0% +the right side which is what we're going +to do here crop make the image as full + + align:start position:0% +to do here crop make the image as full + + + align:start position:0% +to do here crop make the image as full +as we can with + + align:start position:0% +as we can with + + + align:start position:0% +as we can with +out the right-side cropping it out okay + + align:start position:0% +out the right-side cropping it out okay + + + align:start position:0% +out the right-side cropping it out okay +that looks pretty okay and now as we had + + align:start position:0% +that looks pretty okay and now as we had + + + align:start position:0% +that looks pretty okay and now as we had +previously talked about in the animation + + align:start position:0% +previously talked about in the animation + + + align:start position:0% +previously talked about in the animation +we're going to flip one side to another + + align:start position:0% +we're going to flip one side to another + + + align:start position:0% +we're going to flip one side to another +but first in order to do that I'm going + + align:start position:0% +but first in order to do that I'm going + + + align:start position:0% +but first in order to do that I'm going +to expand the canvas to make room for + + align:start position:0% +to expand the canvas to make room for + + + align:start position:0% +to expand the canvas to make room for +the new piece that we're going to start + + align:start position:0% +the new piece that we're going to start + + + align:start position:0% +the new piece that we're going to start +working with so I am in fact taking a + + align:start position:0% +working with so I am in fact taking a + + + align:start position:0% +working with so I am in fact taking a +piece at the left side which is what we + + align:start position:0% +piece at the left side which is what we + + + align:start position:0% +piece at the left side which is what we +talked about + + align:start position:0% +talked about + + + align:start position:0% +talked about +I'm copy and pasting there it is again + + align:start position:0% +I'm copy and pasting there it is again + + + align:start position:0% +I'm copy and pasting there it is again +and we're going to flip it to make up + + align:start position:0% +and we're going to flip it to make up + + + align:start position:0% +and we're going to flip it to make up +for the empty side we'll just flip it + + align:start position:0% +for the empty side we'll just flip it + + + align:start position:0% +for the empty side we'll just flip it +horizontally move it around a bit and + + align:start position:0% +horizontally move it around a bit and + + + align:start position:0% +horizontally move it around a bit and +with a little fudging we get a pretty + + align:start position:0% +with a little fudging we get a pretty + + + align:start position:0% +with a little fudging we get a pretty +nice start for an image that we're + + align:start position:0% +nice start for an image that we're + + + align:start position:0% +nice start for an image that we're +getting to I decided to play more about + + align:start position:0% +getting to I decided to play more about + + + align:start position:0% +getting to I decided to play more about +raising it one more level and so I went + + align:start position:0% +raising it one more level and so I went + + + align:start position:0% +raising it one more level and so I went +back to what we have seen before and in + + align:start position:0% +back to what we have seen before and in + + + align:start position:0% +back to what we have seen before and in +another image where I basically take + + align:start position:0% +another image where I basically take + + + align:start position:0% +another image where I basically take +this pretty good image select the + + align:start position:0% +this pretty good image select the + + + align:start position:0% +this pretty good image select the +background invert the selection so that + + align:start position:0% +background invert the selection so that + + + align:start position:0% +background invert the selection so that +we have in fact selected the liquid + + align:start position:0% +we have in fact selected the liquid + + + align:start position:0% +we have in fact selected the liquid +battery copy and paste and you see here + + align:start position:0% +battery copy and paste and you see here + + + align:start position:0% +battery copy and paste and you see here +we have another layer of just the liquid + + align:start position:0% +we have another layer of just the liquid + + + align:start position:0% +we have another layer of just the liquid +battery and went to layer style and went + + align:start position:0% +battery and went to layer style and went + + + align:start position:0% +battery and went to layer style and went +back to our old drop shadow friend and I + + align:start position:0% +back to our old drop shadow friend and I + + + align:start position:0% +back to our old drop shadow friend and I +played with making a drop shadow which I + + align:start position:0% +played with making a drop shadow which I + + + align:start position:0% +played with making a drop shadow which I +did like I tend to think that it just + + align:start position:0% +did like I tend to think that it just + + + align:start position:0% +did like I tend to think that it just +pushes it away and I think it worked + + align:start position:0% +pushes it away and I think it worked + + + align:start position:0% +pushes it away and I think it worked +quite well eventually what I did wind up + + align:start position:0% +quite well eventually what I did wind up + + + align:start position:0% +quite well eventually what I did wind up +doing is playing a little bit with + + align:start position:0% +doing is playing a little bit with + + + align:start position:0% +doing is playing a little bit with +putting a different background for + + align:start position:0% +putting a different background for + + + align:start position:0% +putting a different background for +example making a gradient that wasn't + + align:start position:0% +example making a gradient that wasn't + + + align:start position:0% +example making a gradient that wasn't +going to work I didn't even know what I + + align:start position:0% +going to work I didn't even know what I + + + align:start position:0% +going to work I didn't even know what I +had in mind but I really wanted + + align:start position:0% +had in mind but I really wanted + + + align:start position:0% +had in mind but I really wanted +something a little more dramatic so + + align:start position:0% +something a little more dramatic so + + + align:start position:0% +something a little more dramatic so +going back to the picture without the + + align:start position:0% +going back to the picture without the + + + align:start position:0% +going back to the picture without the +color in the background on keeping the + + align:start position:0% +color in the background on keeping the + + + align:start position:0% +color in the background on keeping the +drop shadow I went to adjustments + + align:start position:0% +drop shadow I went to adjustments + + + align:start position:0% +drop shadow I went to adjustments +decided to invert the whole picture and + + align:start position:0% +decided to invert the whole picture and + + + align:start position:0% +decided to invert the whole picture and +yes that's quite a unusual image and but + + align:start position:0% +yes that's quite a unusual image and but + + + align:start position:0% +yes that's quite a unusual image and but +decided to do it and play a little bit + + align:start position:0% +decided to do it and play a little bit + + + align:start position:0% +decided to do it and play a little bit +with the hue to get that blue back to + + align:start position:0% +with the hue to get that blue back to + + + align:start position:0% +with the hue to get that blue back to +the orange that I sort of liked wasn't + + align:start position:0% +the orange that I sort of liked wasn't + + + align:start position:0% +the orange that I sort of liked wasn't +quite enough I increase the saturation a + + align:start position:0% +quite enough I increase the saturation a + + + align:start position:0% +quite enough I increase the saturation a +little bit and there it is this was the + + align:start position:0% +little bit and there it is this was the + + + align:start position:0% +little bit and there it is this was the +final image that I showed to the + + align:start position:0% +final image that I showed to the + + + align:start position:0% +final image that I showed to the +researcher and frankly I think we got + + align:start position:0% +researcher and frankly I think we got + + + align:start position:0% +researcher and frankly I think we got +ourselves a winner unfortunately not the + + align:start position:0% +ourselves a winner unfortunately not the + + + align:start position:0% +ourselves a winner unfortunately not the +cover of the journal which I really we + + align:start position:0% +cover of the journal which I really we + + + align:start position:0% +cover of the journal which I really we +were hoping that would happen but it did + + align:start position:0% +were hoping that would happen but it did + + + align:start position:0% +were hoping that would happen but it did +get the home page of the journal and a + + align:start position:0% +get the home page of the journal and a + + + align:start position:0% +get the home page of the journal and a +couple of other home pages of various + + align:start position:0% +couple of other home pages of various + + + align:start position:0% +couple of other home pages of various +journals and it got a lot of attention + + align:start position:0% +journals and it got a lot of attention + + + align:start position:0% +journals and it got a lot of attention +first of all of course the science was + + align:start position:0% +first of all of course the science was + + + align:start position:0% +first of all of course the science was +important but we pretty much agree that + + align:start position:0% +important but we pretty much agree that + + + align:start position:0% +important but we pretty much agree that +making an image to draw attention to the + + align:start position:0% +making an image to draw attention to the + + + align:start position:0% +making an image to draw attention to the +science really is what this image making + + align:start position:0% +science really is what this image making + + + align:start position:0% +science really is what this image making +is about I hope you enjoy this and see + + align:start position:0% +is about I hope you enjoy this and see + + + align:start position:0% +is about I hope you enjoy this and see +the thinking that is extensive when you + + align:start position:0% +the thinking that is extensive when you + + + align:start position:0% +the thinking that is extensive when you +get into something that's complicated \ No newline at end of file diff --git a/gyaqXwi4BDk.txt b/gyaqXwi4BDk.txt new file mode 100644 index 0000000000000000000000000000000000000000..ddb68b1f2e0d880a4a522696fc12587254d843c8 --- /dev/null +++ b/gyaqXwi4BDk.txt @@ -0,0 +1,13931 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT OpenCourseWare continue to + + align:start position:0% +will help MIT OpenCourseWare continue to + + + align:start position:0% +will help MIT OpenCourseWare continue to +offer high quality educational resources + + align:start position:0% +offer high quality educational resources + + + align:start position:0% +offer high quality educational resources +for free + + align:start position:0% +for free + + + align:start position:0% +for free +to make a donation or to view additional + + align:start position:0% +to make a donation or to view additional + + + align:start position:0% +to make a donation or to view additional +materials from hundreds of MIT courses + + align:start position:0% +materials from hundreds of MIT courses + + + align:start position:0% +materials from hundreds of MIT courses +visit MIT opencourseware at ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +okay let's get started on Thursday we + + align:start position:0% +okay let's get started on Thursday we + + + align:start position:0% +okay let's get started on Thursday we +are really privileged to have John + + align:start position:0% +are really privileged to have John + + + align:start position:0% +are really privileged to have John +Bentley who is one of the Masters of + + align:start position:0% +Bentley who is one of the Masters of + + + align:start position:0% +Bentley who is one of the Masters of +performance engineering come and give us + + align:start position:0% +performance engineering come and give us + + + align:start position:0% +performance engineering come and give us +a guest lecture in 1982 he wrote this + + align:start position:0% +a guest lecture in 1982 he wrote this + + + align:start position:0% +a guest lecture in 1982 he wrote this +wonderful little book from which we + + align:start position:0% +wonderful little book from which we + + + align:start position:0% +wonderful little book from which we +adapted the Bentley rules that you folks + + align:start position:0% +adapted the Bentley rules that you folks + + + align:start position:0% +adapted the Bentley rules that you folks +have seen and he's also famous for + + align:start position:0% +have seen and he's also famous for + + + align:start position:0% +have seen and he's also famous for +things like KD trees who's seen KD trees + + align:start position:0% +things like KD trees who's seen KD trees + + + align:start position:0% +things like KD trees who's seen KD trees +yeah so he invented KD trees and who's + + align:start position:0% +yeah so he invented KD trees and who's + + + align:start position:0% +yeah so he invented KD trees and who's +ever used the master method of the + + align:start position:0% +ever used the master method of the + + + align:start position:0% +ever used the master method of the +current saw he invented the master + + align:start position:0% +current saw he invented the master + + + align:start position:0% +current saw he invented the master +method of recurrence solving and so I + + align:start position:0% +method of recurrence solving and so I + + + align:start position:0% +method of recurrence solving and so I +mean he's just a wonderful wonderful + + align:start position:0% +mean he's just a wonderful wonderful + + + align:start position:0% +mean he's just a wonderful wonderful +fellow with lots and lots of insights + + align:start position:0% +fellow with lots and lots of insights + + + align:start position:0% +fellow with lots and lots of insights +and just like a superior performance + + align:start position:0% +and just like a superior performance + + + align:start position:0% +and just like a superior performance +engineer and he's going to talk give a + + align:start position:0% +engineer and he's going to talk give a + + + align:start position:0% +engineer and he's going to talk give a +guest lecture on Thursday and so I would + + align:start position:0% +guest lecture on Thursday and so I would + + + align:start position:0% +guest lecture on Thursday and so I would +encourage you to bring your friends + + align:start position:0% +encourage you to bring your friends + + + align:start position:0% +encourage you to bring your friends +bring friends maybe who dropped the + + align:start position:0% +bring friends maybe who dropped the + + + align:start position:0% +bring friends maybe who dropped the +class okay because this is like this is + + align:start position:0% +class okay because this is like this is + + + align:start position:0% +class okay because this is like this is +the and and others who you may who you + + align:start position:0% +the and and others who you may who you + + + align:start position:0% +the and and others who you may who you +know if any of you have urops other + + align:start position:0% +know if any of you have urops other + + + align:start position:0% +know if any of you have urops other +people in your research group whether + + align:start position:0% +people in your research group whether + + + align:start position:0% +people in your research group whether +there are graduate students or whatever + + align:start position:0% +there are graduate students or whatever + + + align:start position:0% +there are graduate students or whatever +they're all welcome to come because this + + align:start position:0% +they're all welcome to come because this + + + align:start position:0% +they're all welcome to come because this +is really you know one of the + + align:start position:0% +is really you know one of the + + + align:start position:0% +is really you know one of the +opportunities you get to to actually + + align:start position:0% +opportunities you get to to actually + + + align:start position:0% +opportunities you get to to actually +meet one of the you know legends of the + + align:start position:0% +meet one of the you know legends of the + + + align:start position:0% +meet one of the you know legends of the +field if you will and you know have a + + align:start position:0% +field if you will and you know have a + + + align:start position:0% +field if you will and you know have a +and you'll see he's very approachable + + align:start position:0% +and you'll see he's very approachable + + + align:start position:0% +and you'll see he's very approachable +he's very approachable so um so anyway + + align:start position:0% +he's very approachable so um so anyway + + + align:start position:0% +he's very approachable so um so anyway +my advertisement for John Bentley good + + align:start position:0% +my advertisement for John Bentley good + + + align:start position:0% +my advertisement for John Bentley good +so let's start I want to talk about + + align:start position:0% +so let's start I want to talk about + + + align:start position:0% +so let's start I want to talk about +speculative parallelism for a little bit + + align:start position:0% +speculative parallelism for a little bit + + + align:start position:0% +speculative parallelism for a little bit +because that's kind of what you need to + + align:start position:0% +because that's kind of what you need to + + + align:start position:0% +because that's kind of what you need to +make the code go fast so if you look at + + align:start position:0% +make the code go fast so if you look at + + + align:start position:0% +make the code go fast so if you look at +code like alpha beta it turns out that + + align:start position:0% +code like alpha beta it turns out that + + + align:start position:0% +code like alpha beta it turns out that +it's inherently serial okay that is if + + align:start position:0% +it's inherently serial okay that is if + + + align:start position:0% +it's inherently serial okay that is if +you don't you know if you try to do + + align:start position:0% +you don't you know if you try to do + + + align:start position:0% +you don't you know if you try to do +things in parallel then you miss the + + align:start position:0% +things in parallel then you miss the + + + align:start position:0% +things in parallel then you miss the +cut-offs and if you miss the cut-offs + + align:start position:0% +cut-offs and if you miss the cut-offs + + + align:start position:0% +cut-offs and if you miss the cut-offs +you know the beta cut-offs then + + align:start position:0% +you know the beta cut-offs then + + + align:start position:0% +you know the beta cut-offs then +you start doing work that you wouldn't + + align:start position:0% +you start doing work that you wouldn't + + + align:start position:0% +you start doing work that you wouldn't +necessarily need to do and so the only + + align:start position:0% +necessarily need to do and so the only + + + align:start position:0% +necessarily need to do and so the only +way to sort of make this type of code + + align:start position:0% +way to sort of make this type of code + + + align:start position:0% +way to sort of make this type of code +run fast is to use speculation which is + + align:start position:0% +run fast is to use speculation which is + + + align:start position:0% +run fast is to use speculation which is +to say that you're gonna guess that you + + align:start position:0% +to say that you're gonna guess that you + + + align:start position:0% +to say that you're gonna guess that you +can do stuff in parallel and it'll be + + align:start position:0% +can do stuff in parallel and it'll be + + + align:start position:0% +can do stuff in parallel and it'll be +worthwhile and then occasionally you're + + align:start position:0% +worthwhile and then occasionally you're + + + align:start position:0% +worthwhile and then occasionally you're +going to be wrong but the trick is well + + align:start position:0% +going to be wrong but the trick is well + + + align:start position:0% +going to be wrong but the trick is well +how do you minimize the wasted effort + + align:start position:0% +how do you minimize the wasted effort + + + align:start position:0% +how do you minimize the wasted effort +when things go wrong so let's just take + + align:start position:0% +when things go wrong so let's just take + + + align:start position:0% +when things go wrong so let's just take +a look at a very simple example of of + + align:start position:0% + + + + align:start position:0% + +speculative parallelism which is Thresh + + align:start position:0% +speculative parallelism which is Thresh + + + align:start position:0% +speculative parallelism which is Thresh +holding a sum so here we have a little + + align:start position:0% +holding a sum so here we have a little + + + align:start position:0% +holding a sum so here we have a little +program that is returning a boolean it + + align:start position:0% +program that is returning a boolean it + + + align:start position:0% +program that is returning a boolean it +takes as input an array of size n so + + align:start position:0% +takes as input an array of size n so + + + align:start position:0% +takes as input an array of size n so +threshold in sums you have an array a of + + align:start position:0% +threshold in sums you have an array a of + + + align:start position:0% +threshold in sums you have an array a of +length n and a limit and these are all + + align:start position:0% +length n and a limit and these are all + + + align:start position:0% +length n and a limit and these are all +unsigned integers say and I start out + + align:start position:0% +unsigned integers say and I start out + + + align:start position:0% +unsigned integers say and I start out +the summit zero and what I'm gonna do is + + align:start position:0% +the summit zero and what I'm gonna do is + + + align:start position:0% +the summit zero and what I'm gonna do is +add up all the elements of the array and + + align:start position:0% +add up all the elements of the array and + + + align:start position:0% +add up all the elements of the array and +if it exceeds the limit then I'm gonna + + align:start position:0% +if it exceeds the limit then I'm gonna + + + align:start position:0% +if it exceeds the limit then I'm gonna +return okay and so um how might I + + align:start position:0% +return okay and so um how might I + + + align:start position:0% +return okay and so um how might I +optimize this code a little bit yeah + + align:start position:0% + + + + align:start position:0% + +no let's say on one one processor on one + + align:start position:0% +no let's say on one one processor on one + + + align:start position:0% +no let's say on one one processor on one +processor what might you do yeah once + + align:start position:0% +processor what might you do yeah once + + + align:start position:0% +processor what might you do yeah once +you check so that once you would exceed + + align:start position:0% +you check so that once you would exceed + + + align:start position:0% +you check so that once you would exceed +it + + align:start position:0% +it + + + align:start position:0% +it +why keep adding the other numbers okay + + align:start position:0% +why keep adding the other numbers okay + + + align:start position:0% +why keep adding the other numbers okay +so here's a code that does that quit + + align:start position:0% +so here's a code that does that quit + + + align:start position:0% +so here's a code that does that quit +early if the partial product ever sees + + align:start position:0% +early if the partial product ever sees + + + align:start position:0% +early if the partial product ever sees +the threshold this isn't necessarily an + + align:start position:0% +the threshold this isn't necessarily an + + + align:start position:0% +the threshold this isn't necessarily an +optimization it was noticed that now in + + align:start position:0% +optimization it was noticed that now in + + + align:start position:0% +optimization it was noticed that now in +the optimization not only do I have you + + align:start position:0% +the optimization not only do I have you + + + align:start position:0% +the optimization not only do I have you +know a memory reference and in addition + + align:start position:0% +know a memory reference and in addition + + + align:start position:0% +know a memory reference and in addition +I also now have a you know I also have a + + align:start position:0% +I also now have a you know I also have a + + + align:start position:0% +I also now have a you know I also have a +unpredictable branch actually it's + + align:start position:0% +unpredictable branch actually it's + + + align:start position:0% +unpredictable branch actually it's +predictable branch sorry predictable + + align:start position:0% +predictable branch sorry predictable + + + align:start position:0% +predictable branch sorry predictable +branch but it's still one more one more + + align:start position:0% +branch but it's still one more one more + + + align:start position:0% +branch but it's still one more one more +step because it's always going to + + align:start position:0% +step because it's always going to + + + align:start position:0% +step because it's always going to +predict that it's not exceeding until it + + align:start position:0% +predict that it's not exceeding until it + + + align:start position:0% +predict that it's not exceeding until it +actually does exceed so that'll be + + align:start position:0% +actually does exceed so that'll be + + + align:start position:0% +actually does exceed so that'll be +pretty predictable and but still I've + + align:start position:0% +pretty predictable and but still I've + + + align:start position:0% +pretty predictable and but still I've +added something into the loop so that + + align:start position:0% +added something into the loop so that + + + align:start position:0% +added something into the loop so that +maybe so how might I mitigate that + + align:start position:0% +maybe so how might I mitigate that + + + align:start position:0% +maybe so how might I mitigate that +problem so I don't want to add too much + + align:start position:0% +problem so I don't want to add too much + + + align:start position:0% +problem so I don't want to add too much +into the inner loop yeah + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +yeah so basically I can do what's called + + align:start position:0% +yeah so basically I can do what's called + + + align:start position:0% +yeah so basically I can do what's called +strip mining I replace the loop of n + + align:start position:0% +strip mining I replace the loop of n + + + align:start position:0% +strip mining I replace the loop of n +iterations with a loop of let's say n + + align:start position:0% +iterations with a loop of let's say n + + + align:start position:0% +iterations with a loop of let's say n +over four iterations with an inner loop + + align:start position:0% +over four iterations with an inner loop + + + align:start position:0% +over four iterations with an inner loop +of four iterations and every fourth + + align:start position:0% +of four iterations and every fourth + + + align:start position:0% +of four iterations and every fourth +iteration I check to see whether or not + + align:start position:0% +iteration I check to see whether or not + + + align:start position:0% +iteration I check to see whether or not +I've exceeded okay so that the cost of + + align:start position:0% +I've exceeded okay so that the cost of + + + align:start position:0% +I've exceeded okay so that the cost of +the the check is going to be you know + + align:start position:0% +the the check is going to be you know + + + align:start position:0% +the the check is going to be you know +relatively small at that point okay so + + align:start position:0% +relatively small at that point okay so + + + align:start position:0% +relatively small at that point okay so +there are ways of of making this sort of + + align:start position:0% +there are ways of of making this sort of + + + align:start position:0% +there are ways of of making this sort of +go fast okay so now we want to make this + + align:start position:0% +go fast okay so now we want to make this + + + align:start position:0% +go fast okay so now we want to make this +operate in parallel okay and the problem + + align:start position:0% +operate in parallel okay and the problem + + + align:start position:0% +operate in parallel okay and the problem +in when I operate in parallel is that is + + align:start position:0% +in when I operate in parallel is that is + + + align:start position:0% +in when I operate in parallel is that is +that as I'm adding stuff up I want to do + + align:start position:0% +that as I'm adding stuff up I want to do + + + align:start position:0% +that as I'm adding stuff up I want to do +it so I'm going to do this here with a + + align:start position:0% +it so I'm going to do this here with a + + + align:start position:0% +it so I'm going to do this here with a +reducer and so basically I'm going to + + align:start position:0% +reducer and so basically I'm going to + + + align:start position:0% +reducer and so basically I'm going to +add up the values in the reducer but now + + align:start position:0% +add up the values in the reducer but now + + + align:start position:0% +add up the values in the reducer but now +I'd like to do the same thing of being + + align:start position:0% +I'd like to do the same thing of being + + + align:start position:0% +I'd like to do the same thing of being +able to quit early and so the question + + align:start position:0% +able to quit early and so the question + + + align:start position:0% +able to quit early and so the question +is well how can we paralyze a short + + align:start position:0% +is well how can we paralyze a short + + + align:start position:0% +is well how can we paralyze a short +circuited loop okay how can we and so + + align:start position:0% +circuited loop okay how can we and so + + + align:start position:0% +circuited loop okay how can we and so +the way I'm going to do this and this is + + align:start position:0% +the way I'm going to do this and this is + + + align:start position:0% +the way I'm going to do this and this is +sort of by hand here but it's going to + + align:start position:0% +sort of by hand here but it's going to + + + align:start position:0% +sort of by hand here but it's going to +give you so actually as you know + + align:start position:0% +give you so actually as you know + + + align:start position:0% +give you so actually as you know +underneath the loop is really a divide + + align:start position:0% +underneath the loop is really a divide + + + align:start position:0% +underneath the loop is really a divide +and conquer loop and so you know I could + + align:start position:0% +and conquer loop and so you know I could + + + align:start position:0% +and conquer loop and so you know I could +I could write it as a as a parallel loop + + align:start position:0% +I could write it as a as a parallel loop + + + align:start position:0% +I could write it as a as a parallel loop +and now it becomes I think a little bit + + align:start position:0% +and now it becomes I think a little bit + + + align:start position:0% +and now it becomes I think a little bit +clearer how I could in this case what + + align:start position:0% +clearer how I could in this case what + + + align:start position:0% +clearer how I could in this case what +I'm going to do is is return the value + + align:start position:0% +I'm going to do is is return the value + + + align:start position:0% +I'm going to do is is return the value +of the sum and now the question is well + + align:start position:0% +of the sum and now the question is well + + + align:start position:0% +of the sum and now the question is well +how can I quit early and save the work + + align:start position:0% +how can I quit early and save the work + + + align:start position:0% +how can I quit early and save the work +if I exceed the threshold okay + + align:start position:0% +if I exceed the threshold okay + + + align:start position:0% +if I exceed the threshold okay +understanding that you know when I'm + + align:start position:0% +understanding that you know when I'm + + + align:start position:0% +understanding that you know when I'm +executing this in something like silk + + align:start position:0% +executing this in something like silk + + + align:start position:0% +executing this in something like silk +you know it's going to tend to you know + + align:start position:0% +you know it's going to tend to you know + + + align:start position:0% +you know it's going to tend to you know +go down one path and often it's going to + + align:start position:0% +go down one path and often it's going to + + + align:start position:0% +go down one path and often it's going to +be a serial execution so I'd like if + + align:start position:0% +be a serial execution so I'd like if + + + align:start position:0% +be a serial execution so I'd like if +it's if it's possible so here's here's + + align:start position:0% +it's if it's possible so here's here's + + + align:start position:0% +it's if it's possible so here's here's +one way of doing it which is then I + + align:start position:0% +one way of doing it which is then I + + + align:start position:0% +one way of doing it which is then I +add a and abort flag to the code and + + align:start position:0% +add a and abort flag to the code and + + + align:start position:0% +add a and abort flag to the code and +which is going to say whether I should + + align:start position:0% +which is going to say whether I should + + + align:start position:0% +which is going to say whether I should +keep going or whether I have actually + + align:start position:0% +keep going or whether I have actually + + + align:start position:0% +keep going or whether I have actually +exceeded at that point and so I'm going + + align:start position:0% +exceeded at that point and so I'm going + + + align:start position:0% +exceeded at that point and so I'm going +to use that recursively and now I take a + + align:start position:0% +to use that recursively and now I take a + + + align:start position:0% +to use that recursively and now I take a +look at for each time through the loop + + align:start position:0% +look at for each time through the loop + + + align:start position:0% +look at for each time through the loop +or through the divide and conquer I look + + align:start position:0% +or through the divide and conquer I look + + + align:start position:0% +or through the divide and conquer I look +to see whether the sum is greater than a + + align:start position:0% +to see whether the sum is greater than a + + + align:start position:0% +to see whether the sum is greater than a +limit and I haven't you know already + + align:start position:0% +limit and I haven't you know already + + + align:start position:0% +limit and I haven't you know already +aborted the flag then I set the abort + + align:start position:0% +aborted the flag then I set the abort + + + align:start position:0% +aborted the flag then I set the abort +flag to be true okay + + align:start position:0% +flag to be true okay + + + align:start position:0% +flag to be true okay +why do I bother testing the abort flag + + align:start position:0% +why do I bother testing the abort flag + + + align:start position:0% +why do I bother testing the abort flag +before I set it to true so notice that + + align:start position:0% +before I set it to true so notice that + + + align:start position:0% +before I set it to true so notice that +that setting the abort flag is a race + + align:start position:0% +that setting the abort flag is a race + + + align:start position:0% +that setting the abort flag is a race +isn't it a determinacy race okay because + + align:start position:0% +isn't it a determinacy race okay because + + + align:start position:0% +isn't it a determinacy race okay because +I have great thank you it's because I + + align:start position:0% +I have great thank you it's because I + + + align:start position:0% +I have great thank you it's because I +have the the stuff operating in parallel + + align:start position:0% +have the the stuff operating in parallel + + + align:start position:0% +have the the stuff operating in parallel +is all trying to set the abort flag + + align:start position:0% +is all trying to set the abort flag + + + align:start position:0% +is all trying to set the abort flag +whenever something abort so I can have + + align:start position:0% +whenever something abort so I can have + + + align:start position:0% +whenever something abort so I can have +two guys who are in parallel setting the + + align:start position:0% +two guys who are in parallel setting the + + + align:start position:0% +two guys who are in parallel setting the +abort flag but if they're setting it + + align:start position:0% +abort flag but if they're setting it + + + align:start position:0% +abort flag but if they're setting it +they're setting it to the same value so + + align:start position:0% +they're setting it to the same value so + + + align:start position:0% +they're setting it to the same value so +it's a benign race okay assuming your + + align:start position:0% +it's a benign race okay assuming your + + + align:start position:0% +it's a benign race okay assuming your +memory model is such that you can + + align:start position:0% +memory model is such that you can + + + align:start position:0% +memory model is such that you can +actually set the values so so what + + align:start position:0% +actually set the values so so what + + + align:start position:0% +actually set the values so so what +happens here when why do i why do you + + align:start position:0% +happens here when why do i why do you + + + align:start position:0% +happens here when why do i why do you +bother checking this + + align:start position:0% + + + + align:start position:0% + +so what happens when several guys in + + align:start position:0% +so what happens when several guys in + + + align:start position:0% +so what happens when several guys in +parallel want to write to the same + + align:start position:0% +parallel want to write to the same + + + align:start position:0% +parallel want to write to the same +variable this is quiz one stuff yeah + + align:start position:0% +variable this is quiz one stuff yeah + + + align:start position:0% +variable this is quiz one stuff yeah +yeah you can have it bouncing along the + + align:start position:0% +yeah you can have it bouncing along the + + + align:start position:0% +yeah you can have it bouncing along the +cache it will serialize it right because + + align:start position:0% +cache it will serialize it right because + + + align:start position:0% +cache it will serialize it right because +because if they're all trying to to + + align:start position:0% +because if they're all trying to to + + + align:start position:0% +because if they're all trying to to +write then they have to get exclusive + + align:start position:0% +write then they have to get exclusive + + + align:start position:0% +write then they have to get exclusive +access for it to write and modify it and + + align:start position:0% +access for it to write and modify it and + + + align:start position:0% +access for it to write and modify it and +so that happens boom boom boom one at a + + align:start position:0% +so that happens boom boom boom one at a + + + align:start position:0% +so that happens boom boom boom one at a +time + + align:start position:0% +time + + + align:start position:0% +time +and so by checking it first it can be in + + align:start position:0% +and so by checking it first it can be in + + + align:start position:0% +and so by checking it first it can be in +a shared state and then only one guy has + + align:start position:0% +a shared state and then only one guy has + + + align:start position:0% +a shared state and then only one guy has +to one guy clobbers it and then it'll + + align:start position:0% +to one guy clobbers it and then it'll + + + align:start position:0% +to one guy clobbers it and then it'll +update all the other ones so it makes it + + align:start position:0% +update all the other ones so it makes it + + + align:start position:0% +update all the other ones so it makes it +so we don't continually have a true + + align:start position:0% +so we don't continually have a true + + + align:start position:0% +so we don't continually have a true +sharing race and then in the checking to + + align:start position:0% +sharing race and then in the checking to + + + align:start position:0% +sharing race and then in the checking to +see if it exceeds we basically just + + align:start position:0% +see if it exceeds we basically just + + + align:start position:0% +see if it exceeds we basically just +check to see if you know we basically + + align:start position:0% +check to see if you know we basically + + + align:start position:0% +check to see if you know we basically +call this function we set the abort flag + + align:start position:0% +call this function we set the abort flag + + + align:start position:0% +call this function we set the abort flag +to false and then we return the sum of + + align:start position:0% +to false and then we return the sum of + + + align:start position:0% +to false and then we return the sum of +all the values and if it aborts then it + + align:start position:0% +all the values and if it aborts then it + + + align:start position:0% +all the values and if it aborts then it +just returns early okay so it doesn't + + align:start position:0% +just returns early okay so it doesn't + + + align:start position:0% +just returns early okay so it doesn't +have to keep going through the + + align:start position:0% +have to keep going through the + + + align:start position:0% +have to keep going through the +computation and of course once again you + + align:start position:0% +computation and of course once again you + + + align:start position:0% +computation and of course once again you +can coerce in the leaves and so forth so + + align:start position:0% +can coerce in the leaves and so forth so + + + align:start position:0% +can coerce in the leaves and so forth so +so this is non-deterministic code right + + align:start position:0% +so this is non-deterministic code right + + + align:start position:0% +so this is non-deterministic code right +which we should never write unless we + + align:start position:0% +which we should never write unless we + + + align:start position:0% +which we should never write unless we +have to okay because that's the only way + + align:start position:0% +have to okay because that's the only way + + + align:start position:0% +have to okay because that's the only way +of getting performance and you have to + + align:start position:0% +of getting performance and you have to + + + align:start position:0% +of getting performance and you have to +make sure you of course you reset the + + align:start position:0% +make sure you of course you reset the + + + align:start position:0% +make sure you of course you reset the +abort flag after the use and then + + align:start position:0% +abort flag after the use and then + + + align:start position:0% +abort flag after the use and then +actually do you need a memory fence here + + align:start position:0% +actually do you need a memory fence here + + + align:start position:0% +actually do you need a memory fence here +on the abort flag do you need to set you + + align:start position:0% +on the abort flag do you need to set you + + + align:start position:0% +on the abort flag do you need to set you +know where where would you put a an + + align:start position:0% +know where where would you put a an + + + align:start position:0% +know where where would you put a an +abort flag to make sure that the value + + align:start position:0% +abort flag to make sure that the value + + + align:start position:0% +abort flag to make sure that the value +was + + align:start position:0% + + + + align:start position:0% + +yeah yes or what what would you have to + + align:start position:0% +yeah yes or what what would you have to + + + align:start position:0% +yeah yes or what what would you have to +do + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +okay so so indeed it turns out you don't + + align:start position:0% +okay so so indeed it turns out you don't + + + align:start position:0% +okay so so indeed it turns out you don't +need a memory fence here and the reason + + align:start position:0% +need a memory fence here and the reason + + + align:start position:0% +need a memory fence here and the reason +is because the code is correct whether + + align:start position:0% +is because the code is correct whether + + + align:start position:0% +is because the code is correct whether +it's the initial value force or whether + + align:start position:0% +it's the initial value force or whether + + + align:start position:0% +it's the initial value force or whether +it's become true so it doesn't matter + + align:start position:0% +it's become true so it doesn't matter + + + align:start position:0% +it's become true so it doesn't matter +when it becomes true and so there's an + + align:start position:0% +when it becomes true and so there's an + + + align:start position:0% +when it becomes true and so there's an +issue of if you put in the fence then + + align:start position:0% +issue of if you put in the fence then + + + align:start position:0% +issue of if you put in the fence then +you know that it becomes true earlier + + align:start position:0% +you know that it becomes true earlier + + + align:start position:0% +you know that it becomes true earlier +okay rather than waiting for the + + align:start position:0% +okay rather than waiting for the + + + align:start position:0% +okay rather than waiting for the +convocation but that may actually slow + + align:start position:0% +convocation but that may actually slow + + + align:start position:0% +convocation but that may actually slow +things down because memory fences are + + align:start position:0% +things down because memory fences are + + + align:start position:0% +things down because memory fences are +expensive but because the transition is + + align:start position:0% +expensive but because the transition is + + + align:start position:0% +expensive but because the transition is +always from false to true during the + + align:start position:0% +always from false to true during the + + + align:start position:0% +always from false to true during the +execution you don't actually need a + + align:start position:0% +execution you don't actually need a + + + align:start position:0% +execution you don't actually need a +memory fence there okay in order to make + + align:start position:0% +memory fence there okay in order to make + + + align:start position:0% +memory fence there okay in order to make +sure that you've got the correct value + + align:start position:0% +sure that you've got the correct value + + + align:start position:0% +sure that you've got the correct value +does that make sense so you don't need a + + align:start position:0% +does that make sense so you don't need a + + + align:start position:0% +does that make sense so you don't need a +memory fence so so that's a classic + + align:start position:0% +memory fence so so that's a classic + + + align:start position:0% +memory fence so so that's a classic +instance of speculative parallelism it + + align:start position:0% +instance of speculative parallelism it + + + align:start position:0% +instance of speculative parallelism it +occurs when a program spawns some + + align:start position:0% +occurs when a program spawns some + + + align:start position:0% +occurs when a program spawns some +parallel work that might not be + + align:start position:0% +parallel work that might not be + + + align:start position:0% +parallel work that might not be +performed in a serial execution so + + align:start position:0% +performed in a serial execution so + + + align:start position:0% +performed in a serial execution so +you're performing it anticipating that + + align:start position:0% +you're performing it anticipating that + + + align:start position:0% +you're performing it anticipating that +you're probably going to need to do it + + align:start position:0% +you're probably going to need to do it + + + align:start position:0% +you're probably going to need to do it +okay and then typically what you want to + + align:start position:0% +okay and then typically what you want to + + + align:start position:0% +okay and then typically what you want to +do is have some way of backing out if + + align:start position:0% +do is have some way of backing out if + + + align:start position:0% +do is have some way of backing out if +you discover that that you've made made + + align:start position:0% +you discover that that you've made made + + + align:start position:0% +you discover that that you've made made +it you know that you didn't need to do + + align:start position:0% +it you know that you didn't need to do + + + align:start position:0% +it you know that you didn't need to do +that way have some way of making sure + + align:start position:0% +that way have some way of making sure + + + align:start position:0% +that way have some way of making sure +that you don't do any more okay so basic + + align:start position:0% +that you don't do any more okay so basic + + + align:start position:0% +that you don't do any more okay so basic +rule of thumb of speculation is don't + + align:start position:0% +rule of thumb of speculation is don't + + + align:start position:0% +rule of thumb of speculation is don't +spawn speculative work unless there's + + align:start position:0% +spawn speculative work unless there's + + + align:start position:0% +spawn speculative work unless there's +little other opportunity for parallelism + + align:start position:0% +little other opportunity for parallelism + + + align:start position:0% +little other opportunity for parallelism +and there's a good chance that will be + + align:start position:0% +and there's a good chance that will be + + + align:start position:0% +and there's a good chance that will be +needed so one of the things I've seen in + + align:start position:0% +needed so one of the things I've seen in + + + align:start position:0% +needed so one of the things I've seen in +research papers no less is people who + + align:start position:0% +research papers no less is people who + + + align:start position:0% +research papers no less is people who +say oh I'm going to you know I have a + + align:start position:0% +say oh I'm going to you know I have a + + + align:start position:0% +say oh I'm going to you know I have a +calculation where I'm trying to find say + + align:start position:0% +calculation where I'm trying to find say + + + align:start position:0% +calculation where I'm trying to find say +the minimum of a bunch of values and so + + align:start position:0% +the minimum of a bunch of values and so + + + align:start position:0% +the minimum of a bunch of values and so +I'm gonna you know spawn off you know + + align:start position:0% +I'm gonna you know spawn off you know + + + align:start position:0% +I'm gonna you know spawn off you know +end things each of which is looking for + + align:start position:0% +end things each of which is looking for + + + align:start position:0% +end things each of which is looking for +the minimum as soon as the minimum one + + align:start position:0% +the minimum as soon as the minimum one + + + align:start position:0% +the minimum as soon as the minimum one +comes back I'm going to retract all the + + align:start position:0% +comes back I'm going to retract all the + + + align:start position:0% +comes back I'm going to retract all the +other computations and I'm gonna get + + align:start position:0% +other computations and I'm gonna get + + + align:start position:0% +other computations and I'm gonna get +super linear speed-up that way because + + align:start position:0% +super linear speed-up that way because + + + align:start position:0% +super linear speed-up that way because +because in the serial execution I might + + align:start position:0% +because in the serial execution I might + + + align:start position:0% +because in the serial execution I might +have done the longer one first and maybe + + align:start position:0% +have done the longer one first and maybe + + + align:start position:0% +have done the longer one first and maybe +the minimum is not the not the first one + + align:start position:0% +the minimum is not the not the first one + + + align:start position:0% +the minimum is not the not the first one +or whatever and so they they claim super + + align:start position:0% +or whatever and so they they claim super + + + align:start position:0% +or whatever and so they they claim super +linear speed-up by doing speculative + + align:start position:0% +linear speed-up by doing speculative + + + align:start position:0% +linear speed-up by doing speculative +parallelism but that's not really that's + + align:start position:0% +parallelism but that's not really that's + + + align:start position:0% +parallelism but that's not really that's +not really a good example because there + + align:start position:0% +not really a good example because there + + + align:start position:0% +not really a good example because there +was a better serial code if that was + + align:start position:0% +was a better serial code if that was + + + align:start position:0% +was a better serial code if that was +really a good way of doing it they + + align:start position:0% +really a good way of doing it they + + + align:start position:0% +really a good way of doing it they +should have been doing what's called + + align:start position:0% +should have been doing what's called + + + align:start position:0% +should have been doing what's called +dovetailing which is they doing a little + + align:start position:0% +dovetailing which is they doing a little + + + align:start position:0% +dovetailing which is they doing a little +bit of this computation a little bit of + + align:start position:0% +bit of this computation a little bit of + + + align:start position:0% +bit of this computation a little bit of +this a little bit of this a little bit + + align:start position:0% +this a little bit of this a little bit + + + align:start position:0% +this a little bit of this a little bit +of this etc and then going back that + + align:start position:0% +of this etc and then going back that + + + align:start position:0% +of this etc and then going back that +would have been a better algorithm for + + align:start position:0% +would have been a better algorithm for + + + align:start position:0% +would have been a better algorithm for +which you would then use it and the risk + + align:start position:0% +which you would then use it and the risk + + + align:start position:0% +which you would then use it and the risk +they have is that they're spawning off + + align:start position:0% +they have is that they're spawning off + + + align:start position:0% +they have is that they're spawning off +and things of which most of them may not + + align:start position:0% +and things of which most of them may not + + + align:start position:0% +and things of which most of them may not +be needed and now they don't get any + + align:start position:0% +be needed and now they don't get any + + + align:start position:0% +be needed and now they don't get any +speed up even though they've just used a + + align:start position:0% +speed up even though they've just used a + + + align:start position:0% +speed up even though they've just used a +lot more work and that's often is is a + + align:start position:0% +lot more work and that's often is is a + + + align:start position:0% +lot more work and that's often is is a +bad bad choice so usually you don't want + + align:start position:0% +bad bad choice so usually you don't want + + + align:start position:0% +bad bad choice so usually you don't want +to spawn speculative work unless there's + + align:start position:0% +to spawn speculative work unless there's + + + align:start position:0% +to spawn speculative work unless there's +little other opportunity and there's a + + align:start position:0% +little other opportunity and there's a + + + align:start position:0% +little other opportunity and there's a +good chance it'll be needed okay + + align:start position:0% +good chance it'll be needed okay + + + align:start position:0% +good chance it'll be needed okay +my experience is you know how much what + + align:start position:0% +my experience is you know how much what + + + align:start position:0% +my experience is you know how much what +kind of chance do you need you need to + + align:start position:0% +kind of chance do you need you need to + + + align:start position:0% +kind of chance do you need you need to +you know have certainly less than you + + align:start position:0% +you know have certainly less than you + + + align:start position:0% +you know have certainly less than you +know for parallelism you've got to have + + align:start position:0% +know for parallelism you've got to have + + + align:start position:0% +know for parallelism you've got to have +if if the chance that you're going to + + align:start position:0% +if if the chance that you're going to + + + align:start position:0% +if if the chance that you're going to +need the work if you have P processors + + align:start position:0% +need the work if you have P processors + + + align:start position:0% +need the work if you have P processors +if the chance that it could be not + + align:start position:0% +if the chance that it could be not + + + align:start position:0% +if the chance that it could be not +needed is is less than actually have a + + align:start position:0% +needed is is less than actually have a + + + align:start position:0% +needed is is less than actually have a +theorem at the end which I'll which I'll + + align:start position:0% +theorem at the end which I'll which I'll + + + align:start position:0% +theorem at the end which I'll which I'll +I'll refer you to ok because a little + + align:start position:0% +I'll refer you to ok because a little + + + align:start position:0% +I'll refer you to ok because a little +bit hard to say because I didn't put on + + align:start position:0% +bit hard to say because I didn't put on + + + align:start position:0% +bit hard to say because I didn't put on +the slide but there's there's a final + + align:start position:0% +the slide but there's there's a final + + + align:start position:0% +the slide but there's there's a final +slide for this which gives a nice little + + align:start position:0% +slide for this which gives a nice little + + + align:start position:0% +slide for this which gives a nice little +theorem about when you should do this so + + align:start position:0% +theorem about when you should do this so + + + align:start position:0% +theorem about when you should do this so +now let's talk about parallel alpha beta + + align:start position:0% +now let's talk about parallel alpha beta + + + align:start position:0% +now let's talk about parallel alpha beta +search because that's kind of what + + align:start position:0% +search because that's kind of what + + + align:start position:0% +search because that's kind of what +you're doing with your principle + + align:start position:0% +you're doing with your principle + + + align:start position:0% +you're doing with your principle +variation search and so if you remember + + align:start position:0% +variation search and so if you remember + + + align:start position:0% +variation search and so if you remember +the analysis done by Knuth and Morris + + align:start position:0% +the analysis done by Knuth and Morris + + + align:start position:0% +the analysis done by Knuth and Morris +they basically showed that for gram tree + + align:start position:0% +they basically showed that for gram tree + + + align:start position:0% +they basically showed that for gram tree +with branching factor B and depth D and + + align:start position:0% +with branching factor B and depth D and + + + align:start position:0% +with branching factor B and depth D and +alpha beta search with move searched in + + align:start position:0% +alpha beta search with move searched in + + + align:start position:0% +alpha beta search with move searched in +best first order examines that exactly B + + align:start position:0% +best first order examines that exactly B + + + align:start position:0% +best first order examines that exactly B +to the + + align:start position:0% +to the + + + align:start position:0% +to the +d over 2 plus B to the floor of D over 2 + + align:start position:0% +d over 2 plus B to the floor of D over 2 + + + align:start position:0% +d over 2 plus B to the floor of D over 2 +minus 1 nodes at ply D so that's + + align:start position:0% +minus 1 nodes at ply D so that's + + + align:start position:0% +minus 1 nodes at ply D so that's +basically square routing the amount of + + align:start position:0% +basically square routing the amount of + + + align:start position:0% +basically square routing the amount of +work that you would need if you did a + + align:start position:0% +work that you would need if you did a + + + align:start position:0% +work that you would need if you did a +full depth fly that's with alpha beta ok + + align:start position:0% +full depth fly that's with alpha beta ok + + + align:start position:0% +full depth fly that's with alpha beta ok +so naive algorithm looks at B to the D + + align:start position:0% +so naive algorithm looks at B to the D + + + align:start position:0% +so naive algorithm looks at B to the D +nodes at depth D and so for the same + + align:start position:0% +nodes at depth D and so for the same + + + align:start position:0% +nodes at depth D and so for the same +work the search depth is effectively + + align:start position:0% +work the search depth is effectively + + + align:start position:0% +work the search depth is effectively +doubled or the work is Square rooted ok + + align:start position:0% +doubled or the work is Square rooted ok + + + align:start position:0% +doubled or the work is Square rooted ok +so that we saw last time in Helens + + align:start position:0% +so that we saw last time in Helens + + + align:start position:0% +so that we saw last time in Helens +lecture ok so the key optimization here + + align:start position:0% +lecture ok so the key optimization here + + + align:start position:0% +lecture ok so the key optimization here +is pruning the game tree and as I + + align:start position:0% +is pruning the game tree and as I + + + align:start position:0% +is pruning the game tree and as I +mentioned the beginning of this when you + + align:start position:0% +mentioned the beginning of this when you + + + align:start position:0% +mentioned the beginning of this when you +prune the game tree you've got what's + + align:start position:0% +prune the game tree you've got what's + + + align:start position:0% +prune the game tree you've got what's +effectively a serial thing and if you if + + align:start position:0% +effectively a serial thing and if you if + + + align:start position:0% +effectively a serial thing and if you if +you let something go ahead you may be + + align:start position:0% +you let something go ahead you may be + + + align:start position:0% +you let something go ahead you may be +working on something that would be + + align:start position:0% +working on something that would be + + + align:start position:0% +working on something that would be +pruned so then how does the parallelism + + align:start position:0% +pruned so then how does the parallelism + + + align:start position:0% +pruned so then how does the parallelism +really help you there you're just + + align:start position:0% +really help you there you're just + + + align:start position:0% +really help you there you're just +wasting processors it could be better + + align:start position:0% +wasting processors it could be better + + + align:start position:0% +wasting processors it could be better +spent perhaps elsewhere except where + + align:start position:0% +spent perhaps elsewhere except where + + + align:start position:0% +spent perhaps elsewhere except where +else can you spend it because there's no + + align:start position:0% +else can you spend it because there's no + + + align:start position:0% +else can you spend it because there's no +other parallelism in the in the code so + + align:start position:0% +other parallelism in the in the code so + + + align:start position:0% +other parallelism in the in the code so +we want to find some solution so the + + align:start position:0% +we want to find some solution so the + + + align:start position:0% +we want to find some solution so the +solution comes for a from an idea from a + + align:start position:0% +solution comes for a from an idea from a + + + align:start position:0% +solution comes for a from an idea from a +very nice paper by Burkhardt manin and + + align:start position:0% +very nice paper by Burkhardt manin and + + + align:start position:0% +very nice paper by Burkhardt manin and +some of his students in Germany and they + + align:start position:0% +some of his students in Germany and they + + + align:start position:0% +some of his students in Germany and they +made the observation that in a best + + align:start position:0% +made the observation that in a best + + + align:start position:0% +made the observation that in a best +ordered tree the degree of every node is + + align:start position:0% +ordered tree the degree of every node is + + + align:start position:0% +ordered tree the degree of every node is +either either 1 or maximal this is this + + align:start position:0% +either either 1 or maximal this is this + + + align:start position:0% +either either 1 or maximal this is this +is not their observation this is + + align:start position:0% +is not their observation this is + + + align:start position:0% +is not their observation this is +actually the observation in the knuth + + align:start position:0% +actually the observation in the knuth + + + align:start position:0% +actually the observation in the knuth +paper ok so when you have a best ordered + + align:start position:0% +paper ok so when you have a best ordered + + + align:start position:0% +paper ok so when you have a best ordered +tree if you can get all the moves + + align:start position:0% +tree if you can get all the moves + + + align:start position:0% +tree if you can get all the moves +ordered in their true order ok then it + + align:start position:0% +ordered in their true order ok then it + + + align:start position:0% +ordered in their true order ok then it +turns out that either you're you're + + align:start position:0% +turns out that either you're you're + + + align:start position:0% +turns out that either you're you're +exploring all the children or you are + + align:start position:0% +exploring all the children or you are + + + align:start position:0% +exploring all the children or you are +refuting something and you get a cut off + + align:start position:0% +refuting something and you get a cut off + + + align:start position:0% +refuting something and you get a cut off +from the very first one that you look at + + align:start position:0% +from the very first one that you look at + + + align:start position:0% +from the very first one that you look at +ok and so in this case for example it + + align:start position:0% +ok and so in this case for example it + + + align:start position:0% +ok and so in this case for example it +turns out on the principle variation + + align:start position:0% +turns out on the principle variation + + + align:start position:0% +turns out on the principle variation +those are all full + + align:start position:0% +those are all full + + + align:start position:0% +those are all full +with sorry they have you have to explore + + align:start position:0% +with sorry they have you have to explore + + + align:start position:0% +with sorry they have you have to explore +all the children and then from there on + + align:start position:0% +all the children and then from there on + + + align:start position:0% +all the children and then from there on +it alternates one level it's it you know + + align:start position:0% +it alternates one level it's it you know + + + align:start position:0% +it alternates one level it's it you know +it you have just a single child that + + align:start position:0% +it you have just a single child that + + + align:start position:0% +it you have just a single child that +needs to be explored and when you + + align:start position:0% +needs to be explored and when you + + + align:start position:0% +needs to be explored and when you +explore it if it's best ordered you will + + align:start position:0% +explore it if it's best ordered you will + + + align:start position:0% +explore it if it's best ordered you will +get a beta cutoff for the for the others + + align:start position:0% +get a beta cutoff for the for the others + + + align:start position:0% +get a beta cutoff for the for the others +and then it alternates and then it's + + align:start position:0% +and then it alternates and then it's + + + align:start position:0% +and then it alternates and then it's +full width' and so their idea was to say + + align:start position:0% +full width' and so their idea was to say + + + align:start position:0% +full width' and so their idea was to say +well if the first child fails to + + align:start position:0% +well if the first child fails to + + + align:start position:0% +well if the first child fails to +generate a beta cutoff speculate that in + + align:start position:0% +generate a beta cutoff speculate that in + + + align:start position:0% +generate a beta cutoff speculate that in +fact you have the best one and the + + align:start position:0% +fact you have the best one and the + + + align:start position:0% +fact you have the best one and the +remaining children can be searched in + + align:start position:0% +remaining children can be searched in + + + align:start position:0% +remaining children can be searched in +parallel without wasting any work okay + + align:start position:0% +parallel without wasting any work okay + + + align:start position:0% +parallel without wasting any work okay +so if it fails you're gonna say oh I'm + + align:start position:0% +so if it fails you're gonna say oh I'm + + + align:start position:0% +so if it fails you're gonna say oh I'm +gonna speculate that this is in fact a + + align:start position:0% +gonna speculate that this is in fact a + + + align:start position:0% +gonna speculate that this is in fact a +full-width thing now in practice you + + align:start position:0% +full-width thing now in practice you + + + align:start position:0% +full-width thing now in practice you +don't necessarily get things best + + align:start position:0% +don't necessarily get things best + + + align:start position:0% +don't necessarily get things best +ordered but they're a bunch of + + align:start position:0% +ordered but they're a bunch of + + + align:start position:0% +ordered but they're a bunch of +heuristics in the code we've given you + + align:start position:0% +heuristics in the code we've given you + + + align:start position:0% +heuristics in the code we've given you +and in in chess code to make it so that + + align:start position:0% +and in in chess code to make it so that + + + align:start position:0% +and in in chess code to make it so that +you tend to do things in the in the + + align:start position:0% +you tend to do things in the in the + + + align:start position:0% +you tend to do things in the in the +proper order the most important of those + + align:start position:0% +proper order the most important of those + + + align:start position:0% +proper order the most important of those +is have you if you've seen the move + + align:start position:0% +is have you if you've seen the move + + + align:start position:0% +is have you if you've seen the move +before okay and it's in the + + align:start position:0% +before okay and it's in the + + + align:start position:0% +before okay and it's in the +transposition table you use the move + + align:start position:0% +transposition table you use the move + + + align:start position:0% +transposition table you use the move +that you've seen before even if it's to + + align:start position:0% +that you've seen before even if it's to + + + align:start position:0% +that you've seen before even if it's to +a shallower depth okay you guess that + + align:start position:0% +a shallower depth okay you guess that + + + align:start position:0% +a shallower depth okay you guess that +that's going to be their best move still + + align:start position:0% +that's going to be their best move still + + + align:start position:0% +that's going to be their best move still +even if you search deeper and that's + + align:start position:0% +even if you search deeper and that's + + + align:start position:0% +even if you search deeper and that's +pretty good and then you so they call + + align:start position:0% +pretty good and then you so they call + + + align:start position:0% +pretty good and then you so they call +that the young siblings weight algorithm + + align:start position:0% +that the young siblings weight algorithm + + + align:start position:0% +that the young siblings weight algorithm +they actually call it the young brothers + + align:start position:0% +they actually call it the young brothers + + + align:start position:0% +they actually call it the young brothers +weight but in the modern era we call it + + align:start position:0% +weight but in the modern era we call it + + + align:start position:0% +weight but in the modern era we call it +young siblings weight okay + + align:start position:0% +young siblings weight okay + + + align:start position:0% +young siblings weight okay +and we abort sub computations that prove + + align:start position:0% +and we abort sub computations that prove + + + align:start position:0% +and we abort sub computations that prove +to be unnecessary so you're gonna start + + align:start position:0% +to be unnecessary so you're gonna start + + + align:start position:0% +to be unnecessary so you're gonna start +out searching but then you want to you + + align:start position:0% +out searching but then you want to you + + + align:start position:0% +out searching but then you want to you +know get rid of things that you discover + + align:start position:0% +know get rid of things that you discover + + + align:start position:0% +know get rid of things that you discover +oops you know I did get a cutoff from + + align:start position:0% +oops you know I did get a cutoff from + + + align:start position:0% +oops you know I did get a cutoff from +searching from one of these things I + + align:start position:0% +searching from one of these things I + + + align:start position:0% +searching from one of these things I +don't need to do this let's not have it + + align:start position:0% +don't need to do this let's not have it + + + align:start position:0% +don't need to do this let's not have it +keep spawning and generating you know + + align:start position:0% +keep spawning and generating you know + + + align:start position:0% +keep spawning and generating you know +working some other thing let's let's + + align:start position:0% +working some other thing let's let's + + + align:start position:0% +working some other thing let's let's +let's abort it and here's the idea for + + align:start position:0% +let's abort it and here's the idea for + + + align:start position:0% +let's abort it and here's the idea for +the abort mechanism so what you do is + + align:start position:0% +the abort mechanism so what you do is + + + align:start position:0% +the abort mechanism so what you do is +you you know the abort can occur at any + + align:start position:0% +you you know the abort can occur at any + + + align:start position:0% +you you know the abort can occur at any +given node saying I don't need to you + + align:start position:0% +given node saying I don't need to you + + + align:start position:0% +given node saying I don't need to you +get a beta cutoff you want to abort all + + align:start position:0% +get a beta cutoff you want to abort all + + + align:start position:0% +get a beta cutoff you want to abort all +the children that wouldn't have been + + align:start position:0% +the children that wouldn't have been + + + align:start position:0% +the children that wouldn't have been +searched anyway but they may have + + align:start position:0% +searched anyway but they may have + + + align:start position:0% +searched anyway but they may have +already been spawned off so you have a + + align:start position:0% +already been spawned off so you have a + + + align:start position:0% +already been spawned off so you have a +record in each node that tells you + + align:start position:0% +record in each node that tells you + + + align:start position:0% +record in each node that tells you +whether or not you've aborted + + align:start position:0% +whether or not you've aborted + + + align:start position:0% +whether or not you've aborted +and what you do is you just simply climb + + align:start position:0% +and what you do is you just simply climb + + + align:start position:0% +and what you do is you just simply climb +up the tree okay to see whether or not + + align:start position:0% +up the tree okay to see whether or not + + + align:start position:0% +up the tree okay to see whether or not +you know periodically whether or not you + + align:start position:0% +you know periodically whether or not you + + + align:start position:0% +you know periodically whether or not you +have an ancestor who is aborted if you + + align:start position:0% +have an ancestor who is aborted if you + + + align:start position:0% +have an ancestor who is aborted if you +have an ancestor that's aborted says I'm + + align:start position:0% +have an ancestor that's aborted says I'm + + + align:start position:0% +have an ancestor that's aborted says I'm +aborting my sub you know the the side + + align:start position:0% +aborting my sub you know the the side + + + align:start position:0% +aborting my sub you know the the side +computations then you say oh I'm done + + align:start position:0% +computations then you say oh I'm done + + + align:start position:0% +computations then you say oh I'm done +and I just have to return okay and so + + align:start position:0% +and I just have to return okay and so + + + align:start position:0% +and I just have to return okay and so +you check that on a regular basis okay + + align:start position:0% +you check that on a regular basis okay + + + align:start position:0% +you check that on a regular basis okay +so does that do people follow what that + + align:start position:0% +so does that do people follow what that + + + align:start position:0% +so does that do people follow what that +mechanism is and so that's basically + + align:start position:0% +mechanism is and so that's basically + + + align:start position:0% +mechanism is and so that's basically +what you're going to be implementing for + + align:start position:0% +what you're going to be implementing for + + + align:start position:0% +what you're going to be implementing for +you know for the parallelization okay is + + align:start position:0% +you know for the parallelization okay is + + + align:start position:0% +you know for the parallelization okay is +this thing of climbing up you're gonna + + align:start position:0% +this thing of climbing up you're gonna + + + align:start position:0% +this thing of climbing up you're gonna +spawn you know you're gonna guess after + + align:start position:0% +spawn you know you're gonna guess after + + + align:start position:0% +spawn you know you're gonna guess after +you've searched one child that it's good + + align:start position:0% +you've searched one child that it's good + + + align:start position:0% +you've searched one child that it's good +hey actually some people say why don't + + align:start position:0% +hey actually some people say why don't + + + align:start position:0% +hey actually some people say why don't +you check two before you you know search + + align:start position:0% +you check two before you you know search + + + align:start position:0% +you check two before you you know search +the others okay and so that you're even + + align:start position:0% +the others okay and so that you're even + + + align:start position:0% +the others okay and so that you're even +more sure that you don't have a cut off + + align:start position:0% +more sure that you don't have a cut off + + + align:start position:0% +more sure that you don't have a cut off +because neither the first two aborted + + align:start position:0% +because neither the first two aborted + + + align:start position:0% +because neither the first two aborted +because in practice of course the game + + align:start position:0% +because in practice of course the game + + + align:start position:0% +because in practice of course the game +tree is not best ordered and so you're + + align:start position:0% +tree is not best ordered and so you're + + + align:start position:0% +tree is not best ordered and so you're +gonna waste some work okay so but the + + align:start position:0% +gonna waste some work okay so but the + + + align:start position:0% +gonna waste some work okay so but the +idea is you're going to pull up the tree + + align:start position:0% +idea is you're going to pull up the tree + + + align:start position:0% +idea is you're going to pull up the tree +to see whether or not and of course you + + align:start position:0% +to see whether or not and of course you + + + align:start position:0% +to see whether or not and of course you +don't want to pull on every evaluation + + align:start position:0% +don't want to pull on every evaluation + + + align:start position:0% +don't want to pull on every evaluation +that you do you want to just pull + + align:start position:0% +that you do you want to just pull + + + align:start position:0% +that you do you want to just pull +frequently so if you may have a counter + + align:start position:0% +frequently so if you may have a counter + + + align:start position:0% +frequently so if you may have a counter +in there that says okay every tenth time + + align:start position:0% +in there that says okay every tenth time + + + align:start position:0% +in there that says okay every tenth time +I'm going to pull up the tree or every + + align:start position:0% +I'm going to pull up the tree or every + + + align:start position:0% +I'm going to pull up the tree or every +you know you put a voodoo parameter + + align:start position:0% +you know you put a voodoo parameter + + + align:start position:0% +you know you put a voodoo parameter +there that says how often it makes sense + + align:start position:0% +there that says how often it makes sense + + + align:start position:0% +there that says how often it makes sense +to actually check because there's cost + + align:start position:0% +to actually check because there's cost + + + align:start position:0% +to actually check because there's cost +you going up and checking ok versus + + align:start position:0% +you going up and checking ok versus + + + align:start position:0% +you going up and checking ok versus +versus exploring more of the tree okay + + align:start position:0% +versus exploring more of the tree okay + + + align:start position:0% +versus exploring more of the tree okay +and so I have an example here and I + + align:start position:0% +and so I have an example here and I + + + align:start position:0% +and so I have an example here and I +think this is where I'm gonna cut this + + align:start position:0% +think this is where I'm gonna cut this + + + align:start position:0% +think this is where I'm gonna cut this +short so let me there's an example which + + align:start position:0% +short so let me there's an example which + + + align:start position:0% +short so let me there's an example which +I suggest you take a look at I want to + + align:start position:0% +I suggest you take a look at I want to + + + align:start position:0% +I suggest you take a look at I want to +as I say spend time doing QA and talking + + align:start position:0% +as I say spend time doing QA and talking + + + align:start position:0% +as I say spend time doing QA and talking +about the other parts of the program and + + align:start position:0% +about the other parts of the program and + + + align:start position:0% +about the other parts of the program and +give you folks some good ideas for for + + align:start position:0% +give you folks some good ideas for for + + + align:start position:0% +give you folks some good ideas for for +things so this is sort of the theory + + align:start position:0% +things so this is sort of the theory + + + align:start position:0% +things so this is sort of the theory +thing and then I have some slides that + + align:start position:0% +thing and then I have some slides that + + + align:start position:0% +thing and then I have some slides that +will explain this with examples and more + + align:start position:0% +will explain this with examples and more + + + align:start position:0% +will explain this with examples and more +depth because I don't expect that + + align:start position:0% +depth because I don't expect that + + + align:start position:0% +depth because I don't expect that +everybody got every detail of this okay + + align:start position:0% +everybody got every detail of this okay + + + align:start position:0% +everybody got every detail of this okay +so this is the so I have some + + align:start position:0% +so this is the so I have some + + + align:start position:0% +so this is the so I have some +examples and so forth in here that I'm + + align:start position:0% +examples and so forth in here that I'm + + + align:start position:0% +examples and so forth in here that I'm +gonna let you guys look at on your own + + align:start position:0% +gonna let you guys look at on your own + + + align:start position:0% +gonna let you guys look at on your own +okay now if you paralyze the spawning + + align:start position:0% +okay now if you paralyze the spawning + + + align:start position:0% +okay now if you paralyze the spawning +off loop okay of of the the younger + + align:start position:0% +off loop okay of of the the younger + + + align:start position:0% +off loop okay of of the the younger +siblings you will get a code with races + + align:start position:0% +siblings you will get a code with races + + + align:start position:0% +siblings you will get a code with races +okay and the reason you get races is + + align:start position:0% +okay and the reason you get races is + + + align:start position:0% +okay and the reason you get races is +because there are several there are + + align:start position:0% +because there are several there are + + + align:start position:0% +because there are several there are +three data structures okay that the + + align:start position:0% +three data structures okay that the + + + align:start position:0% +three data structures okay that the +search is employing that are that are + + align:start position:0% +search is employing that are that are + + + align:start position:0% +search is employing that are that are +kind of global the first is the + + align:start position:0% +kind of global the first is the + + + align:start position:0% +kind of global the first is the +transposition table looking things up to + + align:start position:0% +transposition table looking things up to + + + align:start position:0% +transposition table looking things up to +see whether or not you've seen them + + align:start position:0% +see whether or not you've seen them + + + align:start position:0% +see whether or not you've seen them +before that's a major optimization you + + align:start position:0% +before that's a major optimization you + + + align:start position:0% +before that's a major optimization you +don't want to get rid of the + + align:start position:0% +don't want to get rid of the + + + align:start position:0% +don't want to get rid of the +transposition table and so you have a + + align:start position:0% +transposition table and so you have a + + + align:start position:0% +transposition table and so you have a +choice for the transposition table what + + align:start position:0% +choice for the transposition table what + + + align:start position:0% +choice for the transposition table what +are you going to do with it are you + + align:start position:0% +are you going to do with it are you + + + align:start position:0% +are you going to do with it are you +going to lock it so that the races + + align:start position:0% +going to lock it so that the races + + + align:start position:0% +going to lock it so that the races +become at least your data race free and + + align:start position:0% +become at least your data race free and + + + align:start position:0% +become at least your data race free and +updated atomically or you could + + align:start position:0% +updated atomically or you could + + + align:start position:0% +updated atomically or you could +replicate it for example you could have + + align:start position:0% +replicate it for example you could have + + + align:start position:0% +replicate it for example you could have +a worker local copy of the data + + align:start position:0% +a worker local copy of the data + + + align:start position:0% +a worker local copy of the data +structure and each each worker that is + + align:start position:0% +structure and each each worker that is + + + align:start position:0% +structure and each each worker that is +working on it only accesses their own + + align:start position:0% +working on it only accesses their own + + + align:start position:0% +working on it only accesses their own +local copies okay you know or you know + + align:start position:0% +local copies okay you know or you know + + + align:start position:0% +local copies okay you know or you know +you can use a you can make a copy when + + align:start position:0% +you can use a you can make a copy when + + + align:start position:0% +you can use a you can make a copy when +things are stolen or you can make just + + align:start position:0% +things are stolen or you can make just + + + align:start position:0% +things are stolen or you can make just +one where you just maintain it locally + + align:start position:0% +one where you just maintain it locally + + + align:start position:0% +one where you just maintain it locally +or you can decide that well you know + + align:start position:0% +or you can decide that well you know + + + align:start position:0% +or you can decide that well you know +even if there's a race there the odds + + align:start position:0% +even if there's a race there the odds + + + align:start position:0% +even if there's a race there the odds +that it's going to affect how I play in + + align:start position:0% +that it's going to affect how I play in + + + align:start position:0% +that it's going to affect how I play in +the game are not that high so I'll run + + align:start position:0% +the game are not that high so I'll run + + + align:start position:0% +the game are not that high so I'll run +with race okay because any other + + align:start position:0% +with race okay because any other + + + align:start position:0% +with race okay because any other +solution is going to be is going to be + + align:start position:0% +solution is going to be is going to be + + + align:start position:0% +solution is going to be is going to be +more expensive okay and and then maybe + + align:start position:0% +more expensive okay and and then maybe + + + align:start position:0% +more expensive okay and and then maybe +you get funny answers so one thing is + + align:start position:0% +you get funny answers so one thing is + + + align:start position:0% +you get funny answers so one thing is +for for that kind of data structure let + + align:start position:0% +for for that kind of data structure let + + + align:start position:0% +for for that kind of data structure let +me just recommend is that you have some + + align:start position:0% +me just recommend is that you have some + + + align:start position:0% +me just recommend is that you have some +way of turning off the data structure so + + align:start position:0% +way of turning off the data structure so + + + align:start position:0% +way of turning off the data structure so +that you can actually do the parallel + + align:start position:0% +that you can actually do the parallel + + + align:start position:0% +that you can actually do the parallel +search and get deterministic repeatable + + align:start position:0% +search and get deterministic repeatable + + + align:start position:0% +search and get deterministic repeatable +results + + align:start position:0% +results + + + align:start position:0% +results +okay so even though it may be aborting + + align:start position:0% +okay so even though it may be aborting + + + align:start position:0% +okay so even though it may be aborting +some things may not be aborting you want + + align:start position:0% +some things may not be aborting you want + + + align:start position:0% +some things may not be aborting you want +to have some way of executing and so for + + align:start position:0% +to have some way of executing and so for + + + align:start position:0% +to have some way of executing and so for +example you want to be able to turn off + + align:start position:0% +example you want to be able to turn off + + + align:start position:0% +example you want to be able to turn off +even the speculation in your code so you + + align:start position:0% +even the speculation in your code so you + + + align:start position:0% +even the speculation in your code so you +can test all the other things in your + + align:start position:0% +can test all the other things in your + + + align:start position:0% +can test all the other things in your +code that don't depend on the + + align:start position:0% +code that don't depend on the + + + align:start position:0% +code that don't depend on the +speculation okay because if you have + + align:start position:0% +speculation okay because if you have + + + align:start position:0% +speculation okay because if you have +something that's not deterministic as I + + align:start position:0% +something that's not deterministic as I + + + align:start position:0% +something that's not deterministic as I +say it's a nightmare to debug okay so we + + align:start position:0% +say it's a nightmare to debug okay so we + + + align:start position:0% +say it's a nightmare to debug okay so we +valued you know your value you're gonna + + align:start position:0% +valued you know your value you're gonna + + + align:start position:0% +valued you know your value you're gonna +do the evaluation function hey turn off + + align:start position:0% +do the evaluation function hey turn off + + + align:start position:0% +do the evaluation function hey turn off +if you're testing it turn off the + + align:start position:0% +if you're testing it turn off the + + + align:start position:0% +if you're testing it turn off the +speculation that you should be able to + + align:start position:0% +speculation that you should be able to + + + align:start position:0% +speculation that you should be able to +find out whether you've got bugs in your + + align:start position:0% +find out whether you've got bugs in your + + + align:start position:0% +find out whether you've got bugs in your +evaluation function there's no point in + + align:start position:0% +evaluation function there's no point in + + + align:start position:0% +evaluation function there's no point in +discovering you of a bug and it's like + + align:start position:0% +discovering you of a bug and it's like + + + align:start position:0% +discovering you of a bug and it's like +well where did it come from or whatever + + align:start position:0% +well where did it come from or whatever + + + align:start position:0% +well where did it come from or whatever +okay so you want to have things + + align:start position:0% +okay so you want to have things + + + align:start position:0% +okay so you want to have things +returning out and also you want to have + + align:start position:0% +returning out and also you want to have + + + align:start position:0% +returning out and also you want to have +ways of turning off for example access + + align:start position:0% +ways of turning off for example access + + + align:start position:0% +ways of turning off for example access +to the transposition table yes I'm going + + align:start position:0% +to the transposition table yes I'm going + + + align:start position:0% +to the transposition table yes I'm going +to speculate but no I'm not going to + + align:start position:0% +to speculate but no I'm not going to + + + align:start position:0% +to speculate but no I'm not going to +access the transposition table in + + align:start position:0% +access the transposition table in + + + align:start position:0% +access the transposition table in +parallel because because I may get a + + align:start position:0% +parallel because because I may get a + + + align:start position:0% +parallel because because I may get a +race on the entry in the transposition + + align:start position:0% +race on the entry in the transposition + + + align:start position:0% +race on the entry in the transposition +table okay + + align:start position:0% +table okay + + + align:start position:0% +table okay +I will the the hint that I will give you + + align:start position:0% +I will the the hint that I will give you + + + align:start position:0% +I will the the hint that I will give you +for that is that in the in the code that + + align:start position:0% +for that is that in the in the code that + + + align:start position:0% +for that is that in the in the code that +for our program that took second prize + + align:start position:0% +for our program that took second prize + + + align:start position:0% +for our program that took second prize +in the world computer Chess Championship + + align:start position:0% +in the world computer Chess Championship + + + align:start position:0% +in the world computer Chess Championship +many years ago I think it was in 1999 + + align:start position:0% + + + + align:start position:0% + +where we we actually almost won the + + align:start position:0% +where we we actually almost won the + + + align:start position:0% +where we we actually almost won the +tournament and it's a and we got we lost + + align:start position:0% +tournament and it's a and we got we lost + + + align:start position:0% +tournament and it's a and we got we lost +in the playoff we we would have won the + + align:start position:0% +in the playoff we we would have won the + + + align:start position:0% +in the playoff we we would have won the +tournament except that we suggested our + + align:start position:0% +tournament except that we suggested our + + + align:start position:0% +tournament except that we suggested our +programmers suggested a rule change at + + align:start position:0% +programmers suggested a rule change at + + + align:start position:0% +programmers suggested a rule change at +the beginning of the tournament that + + align:start position:0% +the beginning of the tournament that + + + align:start position:0% +the beginning of the tournament that +everybody agreed to and then we were on + + align:start position:0% +everybody agreed to and then we were on + + + align:start position:0% +everybody agreed to and then we were on +the short end of that otherwise we would + + align:start position:0% +the short end of that otherwise we would + + + align:start position:0% +the short end of that otherwise we would +have been world champions and that was + + align:start position:0% +have been world champions and that was + + + align:start position:0% +have been world champions and that was +the last competition against computers + + align:start position:0% +the last competition against computers + + + align:start position:0% +the last competition against computers +that deep-blue the IBM computer that + + align:start position:0% +that deep-blue the IBM computer that + + + align:start position:0% +that deep-blue the IBM computer that +beat Kasparov the the human channa it's + + align:start position:0% +beat Kasparov the the human channa it's + + + align:start position:0% +beat Kasparov the the human channa it's +just a few months later they performed + + align:start position:0% +just a few months later they performed + + + align:start position:0% +just a few months later they performed +it and we actually they placed third in + + align:start position:0% +it and we actually they placed third in + + + align:start position:0% +it and we actually they placed third in +the tournament we tied for first + + align:start position:0% +the tournament we tied for first + + + align:start position:0% +the tournament we tied for first +our only loss was to deep blue okay and + + align:start position:0% +our only loss was to deep blue okay and + + + align:start position:0% +our only loss was to deep blue okay and +we were running on an 1824 node soup + + align:start position:0% +we were running on an 1824 node soup + + + align:start position:0% +we were running on an 1824 node soup +computer at Sandia National Labs a + + align:start position:0% +computer at Sandia National Labs a + + + align:start position:0% +computer at Sandia National Labs a +computer that probably is today less + + align:start position:0% +computer that probably is today less + + + align:start position:0% +computer that probably is today less +powerful than this okay so but it was + + align:start position:0% +powerful than this okay so but it was + + + align:start position:0% +powerful than this okay so but it was +you know it was very big type of + + align:start position:0% +you know it was very big type of + + + align:start position:0% +you know it was very big type of +computation so we you know and we were + + align:start position:0% +computation so we you know and we were + + + align:start position:0% +computation so we you know and we were +you know it they basically said if + + align:start position:0% +you know it they basically said if + + + align:start position:0% +you know it they basically said if +there's a tie they're gonna base base + + align:start position:0% +there's a tie they're gonna base base + + + align:start position:0% +there's a tie they're gonna base base +who wins on strength of opponents so you + + align:start position:0% +who wins on strength of opponents so you + + + align:start position:0% +who wins on strength of opponents so you +take a look at your opponent's records + + align:start position:0% +take a look at your opponent's records + + + align:start position:0% +take a look at your opponent's records +and if you had stronger opponents you'll + + align:start position:0% +and if you had stronger opponents you'll + + + align:start position:0% +and if you had stronger opponents you'll +win against somebody and we said you + + align:start position:0% +win against somebody and we said you + + + align:start position:0% +win against somebody and we said you +know if there's a tie just between two + + align:start position:0% +know if there's a tie just between two + + + align:start position:0% +know if there's a tie just between two +programs we should really have them you + + align:start position:0% +programs we should really have them you + + + align:start position:0% +programs we should really have them you +know face off against each other as an + + align:start position:0% +know face off against each other as an + + + align:start position:0% +know face off against each other as an +extra round and everything yeah that's a + + align:start position:0% +extra round and everything yeah that's a + + + align:start position:0% +extra round and everything yeah that's a +good idea and then wouldn't you know at + + align:start position:0% +good idea and then wouldn't you know at + + + align:start position:0% +good idea and then wouldn't you know at +the end we had the strongest you know + + align:start position:0% +the end we had the strongest you know + + + align:start position:0% +the end we had the strongest you know +opponents and and we were tied with + + align:start position:0% +opponents and and we were tied with + + + align:start position:0% +opponents and and we were tied with +another program called fritz an + + align:start position:0% +another program called fritz an + + + align:start position:0% +another program called fritz an +excellent program and we were out + + align:start position:0% +excellent program and we were out + + + align:start position:0% +excellent program and we were out +searching fritz in the in the playoff + + align:start position:0% +searching fritz in the in the playoff + + + align:start position:0% +searching fritz in the in the playoff +game and then we saw a move that in + + align:start position:0% +game and then we saw a move that in + + + align:start position:0% +game and then we saw a move that in +afterwards we when we were able to do + + align:start position:0% +afterwards we when we were able to do + + + align:start position:0% +afterwards we when we were able to do +offline searches deeper we were out + + align:start position:0% +offline searches deeper we were out + + + align:start position:0% +offline searches deeper we were out +searching them by like two ply okay and + + align:start position:0% +searching them by like two ply okay and + + + align:start position:0% +searching them by like two ply okay and +then but then we there's a move that + + align:start position:0% +then but then we there's a move that + + + align:start position:0% +then but then we there's a move that +looks like it's a good move for the + + align:start position:0% +looks like it's a good move for the + + + align:start position:0% +looks like it's a good move for the +depth we were looking at it doesn't look + + align:start position:0% +depth we were looking at it doesn't look + + + align:start position:0% +depth we were looking at it doesn't look +like a good move if you search much + + align:start position:0% +like a good move if you search much + + + align:start position:0% +like a good move if you search much +deeper or frankly if you search much + + align:start position:0% +deeper or frankly if you search much + + + align:start position:0% +deeper or frankly if you search much +shallower is one of these things where + + align:start position:0% +shallower is one of these things where + + + align:start position:0% +shallower is one of these things where +just look like a good move for the ply + + align:start position:0% +just look like a good move for the ply + + + align:start position:0% +just look like a good move for the ply +we happen to be searching because + + align:start position:0% +we happen to be searching because + + + align:start position:0% +we happen to be searching because +there's no guarantee because you can't + + align:start position:0% +there's no guarantee because you can't + + + align:start position:0% +there's no guarantee because you can't +see the end of the game there's no + + align:start position:0% +see the end of the game there's no + + + align:start position:0% +see the end of the game there's no +guarantee that if you search deeper + + align:start position:0% +guarantee that if you search deeper + + + align:start position:0% +guarantee that if you search deeper +you're actually going to beat somebody + + align:start position:0% +you're actually going to beat somebody + + + align:start position:0% +you're actually going to beat somebody +else okay sometime because there's the + + align:start position:0% +else okay sometime because there's the + + + align:start position:0% +else okay sometime because there's the +horizon effect of you can't just simply + + align:start position:0% +horizon effect of you can't just simply + + + align:start position:0% +horizon effect of you can't just simply +can't see what's coming up in the future + + align:start position:0% +can't see what's coming up in the future + + + align:start position:0% +can't see what's coming up in the future +you can only see sort of on average so + + align:start position:0% +you can only see sort of on average so + + + align:start position:0% +you can only see sort of on average so +we made this bad move we almost + + align:start position:0% +we made this bad move we almost + + + align:start position:0% +we made this bad move we almost +recovered we almost tied had we tied we + + align:start position:0% +recovered we almost tied had we tied we + + + align:start position:0% +recovered we almost tied had we tied we +would have been world champions because + + align:start position:0% +would have been world champions because + + + align:start position:0% +would have been world champions because +we had the stronger we won the + + align:start position:0% +we had the stronger we won the + + + align:start position:0% +we had the stronger we won the +tiebreaker and we weren't able to + + align:start position:0% +tiebreaker and we weren't able to + + + align:start position:0% +tiebreaker and we weren't able to +recover from the from the error and so + + align:start position:0% +recover from the from the error and so + + + align:start position:0% +recover from the from the error and so +we took second prize as like + + align:start position:0% + + + + align:start position:0% + +anyway in that program we decided that + + align:start position:0% +anyway in that program we decided that + + + align:start position:0% +anyway in that program we decided that +we were just gonna let there be a race + + align:start position:0% +we were just gonna let there be a race + + + align:start position:0% +we were just gonna let there be a race +and the Rhian the transposition table + + align:start position:0% +and the Rhian the transposition table + + + align:start position:0% +and the Rhian the transposition table +and the reason was we calculated what + + align:start position:0% +and the reason was we calculated what + + + align:start position:0% +and the reason was we calculated what +are the odds that the race actually + + align:start position:0% +are the odds that the race actually + + + align:start position:0% +are the odds that the race actually +affects the value that you would + + align:start position:0% +affects the value that you would + + + align:start position:0% +affects the value that you would +actually pick that value and if it + + align:start position:0% +actually pick that value and if it + + + align:start position:0% +actually pick that value and if it +affected the value what are the odds + + align:start position:0% +affected the value what are the odds + + + align:start position:0% +affected the value what are the odds +that affects the move that you're gonna + + align:start position:0% +that affects the move that you're gonna + + + align:start position:0% +that affects the move that you're gonna +make and it affects the move you're + + align:start position:0% +make and it affects the move you're + + + align:start position:0% +make and it affects the move you're +gonna make what are the odds that + + align:start position:0% +gonna make what are the odds that + + + align:start position:0% +gonna make what are the odds that +affects the the game and if he affects + + align:start position:0% +affects the the game and if he affects + + + align:start position:0% +affects the the game and if he affects +the game what are the odds that affects + + align:start position:0% +the game what are the odds that affects + + + align:start position:0% +the game what are the odds that affects +your result in the tournament and when + + align:start position:0% +your result in the tournament and when + + + align:start position:0% +your result in the tournament and when +you figured all these things out it was + + align:start position:0% +you figured all these things out it was + + + align:start position:0% +you figured all these things out it was +like and we would slow the program down + + align:start position:0% +like and we would slow the program down + + + align:start position:0% +like and we would slow the program down +more by putting in for example locking + + align:start position:0% +more by putting in for example locking + + + align:start position:0% +more by putting in for example locking +okay because that would slow down every + + align:start position:0% +okay because that would slow down every + + + align:start position:0% +okay because that would slow down every +access then we would if we just if we + + align:start position:0% +access then we would if we just if we + + + align:start position:0% +access then we would if we just if we +just ran things because one of the + + align:start position:0% +just ran things because one of the + + + align:start position:0% +just ran things because one of the +things that happens in alpha beta that + + align:start position:0% +things that happens in alpha beta that + + + align:start position:0% +things that happens in alpha beta that +that thing is if you get an extreme + + align:start position:0% +that thing is if you get an extreme + + + align:start position:0% +that thing is if you get an extreme +value usually those are locked off + + align:start position:0% +value usually those are locked off + + + align:start position:0% +value usually those are locked off +because if it's such a good move for you + + align:start position:0% +because if it's such a good move for you + + + align:start position:0% +because if it's such a good move for you +your opponent's not going to let you + + align:start position:0% +your opponent's not going to let you + + + align:start position:0% +your opponent's not going to let you +play it so if you ended up with a score + + align:start position:0% +play it so if you ended up with a score + + + align:start position:0% +play it so if you ended up with a score +that was extreme because it was based on + + align:start position:0% +that was extreme because it was based on + + + align:start position:0% +that was extreme because it was based on +a value that you were racing on usually + + align:start position:0% +a value that you were racing on usually + + + align:start position:0% +a value that you were racing on usually +it's gonna not even propagate up to the + + align:start position:0% +it's gonna not even propagate up to the + + + align:start position:0% +it's gonna not even propagate up to the +root of the tree so anyway so we just + + align:start position:0% +root of the tree so anyway so we just + + + align:start position:0% +root of the tree so anyway so we just +ran you know naked so to speak so there + + align:start position:0% +ran you know naked so to speak so there + + + align:start position:0% +ran you know naked so to speak so there +are two other data structures you're + + align:start position:0% +are two other data structures you're + + + align:start position:0% +are two other data structures you're +gonna have to worry about to make + + align:start position:0% +gonna have to worry about to make + + + align:start position:0% +gonna have to worry about to make +decision about another one is the killer + + align:start position:0% +decision about another one is the killer + + + align:start position:0% +decision about another one is the killer +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +data structure so the killer data + + align:start position:0% +data structure so the killer data + + + align:start position:0% +data structure so the killer data +structure is a heuristic that says you + + align:start position:0% +structure is a heuristic that says you + + + align:start position:0% +structure is a heuristic that says you +know at a given depth of code you tend + + align:start position:0% +know at a given depth of code you tend + + + align:start position:0% +know at a given depth of code you tend +to see the same moves that are good and + + align:start position:0% +to see the same moves that are good and + + + align:start position:0% +to see the same moves that are good and +a move that is good for one for one + + align:start position:0% +a move that is good for one for one + + + align:start position:0% +a move that is good for one for one +thing at a given depth tends to be good + + align:start position:0% +thing at a given depth tends to be good + + + align:start position:0% +thing at a given depth tends to be good +for something else so for example it may + + align:start position:0% +for something else so for example it may + + + align:start position:0% +for something else so for example it may +be that you know you play Bishop takes + + align:start position:0% +be that you know you play Bishop takes + + + align:start position:0% +be that you know you play Bishop takes +Queen + + align:start position:0% +Queen + + + align:start position:0% +Queen +okay so you've won the other players + + align:start position:0% +okay so you've won the other players + + + align:start position:0% +okay so you've won the other players +Queen and then their response is thier + + align:start position:0% +Queen and then their response is thier + + + align:start position:0% +Queen and then their response is thier +response is to do something irrelevant + + align:start position:0% +response is to do something irrelevant + + + align:start position:0% +response is to do something irrelevant +okay well now you've you know you made + + align:start position:0% +okay well now you've you know you made + + + align:start position:0% +okay well now you've you know you made +them okay well there's a lot of other + + align:start position:0% +them okay well there's a lot of other + + + align:start position:0% +them okay well there's a lot of other +moves where you know you could make them + + align:start position:0% +moves where you know you could make them + + + align:start position:0% +moves where you know you could make them +on that move okay for which they're + + align:start position:0% +on that move okay for which they're + + + align:start position:0% +on that move okay for which they're +playing things on the board that are + + align:start position:0% +playing things on the board that are + + + align:start position:0% +playing things on the board that are +irrelevant okay and so the same type of + + align:start position:0% +irrelevant okay and so the same type of + + + align:start position:0% +irrelevant okay and so the same type of +move tends to be a killer always you're + + align:start position:0% +move tends to be a killer always you're + + + align:start position:0% +move tends to be a killer always you're +you're able to you know at that depth in + + align:start position:0% +you're able to you know at that depth in + + + align:start position:0% +you're able to you know at that depth in +that position you're you're able to make + + align:start position:0% +that position you're you're able to make + + + align:start position:0% +that position you're you're able to make +the same move in it you know if they + + align:start position:0% +the same move in it you know if they + + + align:start position:0% +the same move in it you know if they +don't address the issue that's always a + + align:start position:0% +don't address the issue that's always a + + + align:start position:0% +don't address the issue that's always a +good move to check and so that ends up + + align:start position:0% +good move to check and so that ends up + + + align:start position:0% +good move to check and so that ends up +being ordered near the front so the + + align:start position:0% +being ordered near the front so the + + + align:start position:0% +being ordered near the front so the +killer table keeps track of that and I + + align:start position:0% +killer table keeps track of that and I + + + align:start position:0% +killer table keeps track of that and I +think in our code we have two killers is + + align:start position:0% +think in our code we have two killers is + + + align:start position:0% +think in our code we have two killers is +that right Helen I think we it's I think + + align:start position:0% +that right Helen I think we it's I think + + + align:start position:0% +that right Helen I think we it's I think +it's set up to allow you to do for up to + + align:start position:0% +it's set up to allow you to do for up to + + + align:start position:0% +it's set up to allow you to do for up to +four killers but we only do two in the + + align:start position:0% +four killers but we only do two in the + + + align:start position:0% +four killers but we only do two in the +code that we gave you I mean you can + + align:start position:0% +code that we gave you I mean you can + + + align:start position:0% +code that we gave you I mean you can +enable it and see whether four killers + + align:start position:0% +enable it and see whether four killers + + + align:start position:0% +enable it and see whether four killers +me but that's a shared data structure + + align:start position:0% +me but that's a shared data structure + + + align:start position:0% +me but that's a shared data structure +and so one of the questions is should + + align:start position:0% +and so one of the questions is should + + + align:start position:0% +and so one of the questions is should +you be keeping a local copy of that or + + align:start position:0% +you be keeping a local copy of that or + + + align:start position:0% +you be keeping a local copy of that or +should you be you know using a global + + align:start position:0% +should you be you know using a global + + + align:start position:0% +should you be you know using a global +one that they all share okay and + + align:start position:0% +one that they all share okay and + + + align:start position:0% +one that they all share okay and +updating it the third one is the best + + align:start position:0% +updating it the third one is the best + + + align:start position:0% +updating it the third one is the best +move table which is used to order all + + align:start position:0% +move table which is used to order all + + + align:start position:0% +move table which is used to order all +the low order things so the first thing + + align:start position:0% +the low order things so the first thing + + + align:start position:0% +the low order things so the first thing +we most important is did you get a move + + align:start position:0% +we most important is did you get a move + + + align:start position:0% +we most important is did you get a move +out of the transposition table that + + align:start position:0% +out of the transposition table that + + + align:start position:0% +out of the transposition table that +tends to be quite accurate then second + + align:start position:0% +tends to be quite accurate then second + + + align:start position:0% +tends to be quite accurate then second +is did you get a move out of did you get + + align:start position:0% +is did you get a move out of did you get + + + align:start position:0% +is did you get a move out of did you get +a move out of the killer table and + + align:start position:0% +a move out of the killer table and + + + align:start position:0% +a move out of the killer table and +finally it's sort of like statistically + + align:start position:0% +finally it's sort of like statistically + + + align:start position:0% +finally it's sort of like statistically +how good are these moves have you seen + + align:start position:0% +how good are these moves have you seen + + + align:start position:0% +how good are these moves have you seen +these a lot before and if you've seen + + align:start position:0% +these a lot before and if you've seen + + + align:start position:0% +these a lot before and if you've seen +them a lot before that's how the other + + align:start position:0% +them a lot before that's how the other + + + align:start position:0% +them a lot before that's how the other +moves get ordered and that's kept in the + + align:start position:0% +moves get ordered and that's kept in the + + + align:start position:0% +moves get ordered and that's kept in the +best move table and once again that's a + + align:start position:0% +best move table and once again that's a + + + align:start position:0% +best move table and once again that's a +shared table in the search you're gonna + + align:start position:0% +shared table in the search you're gonna + + + align:start position:0% +shared table in the search you're gonna +have to figure out do you want to do a + + align:start position:0% +have to figure out do you want to do a + + + align:start position:0% +have to figure out do you want to do a +thread-local you know worker local copy + + align:start position:0% +thread-local you know worker local copy + + + align:start position:0% +thread-local you know worker local copy +or do you want to do you want to you + + align:start position:0% +or do you want to do you want to you + + + align:start position:0% +or do you want to do you want to you +know synchronize it or how are you going + + align:start position:0% +know synchronize it or how are you going + + + align:start position:0% +know synchronize it or how are you going +to manage that data structure okay and + + align:start position:0% +to manage that data structure okay and + + + align:start position:0% +to manage that data structure okay and +the answer I would say is different for + + align:start position:0% +the answer I would say is different for + + + align:start position:0% +the answer I would say is different for +the compared to what you do with a + + align:start position:0% +the compared to what you do with a + + + align:start position:0% +the compared to what you do with a +transposition table okay transposition + + align:start position:0% +transposition table okay transposition + + + align:start position:0% +transposition table okay transposition +table generally it's not worth locking + + align:start position:0% +table generally it's not worth locking + + + align:start position:0% +table generally it's not worth locking +or or whatever and it is good to share + + align:start position:0% +or or whatever and it is good to share + + + align:start position:0% +or or whatever and it is good to share +because if you have seen that move + + align:start position:0% +because if you have seen that move + + + align:start position:0% +because if you have seen that move +before that saved you a huge amount of + + align:start position:0% +before that saved you a huge amount of + + + align:start position:0% +before that saved you a huge amount of +computation + + align:start position:0% +computation + + + align:start position:0% +computation +to be able to look it up and not not do + + align:start position:0% +to be able to look it up and not not do + + + align:start position:0% +to be able to look it up and not not do +it okay so those are some of the tips + + align:start position:0% +it okay so those are some of the tips + + + align:start position:0% +it okay so those are some of the tips +for parallelization which we'll get to + + align:start position:0% +for parallelization which we'll get to + + + align:start position:0% +for parallelization which we'll get to +in the beta too but now I want to talk + + align:start position:0% +in the beta too but now I want to talk + + + align:start position:0% +in the beta too but now I want to talk +about for most of the rest of time talk + + align:start position:0% +about for most of the rest of time talk + + + align:start position:0% +about for most of the rest of time talk +about some of the other things that you + + align:start position:0% +about some of the other things that you + + + align:start position:0% +about some of the other things that you +can do with the code you've currently + + align:start position:0% +can do with the code you've currently + + + align:start position:0% +can do with the code you've currently +got and let me take these in some some + + align:start position:0% +got and let me take these in some some + + + align:start position:0% +got and let me take these in some some +order and then we can ask questions so + + align:start position:0% +order and then we can ask questions so + + + align:start position:0% +order and then we can ask questions so +open you who's contemplating doing an + + align:start position:0% +open you who's contemplating doing an + + + align:start position:0% +open you who's contemplating doing an +opening book anybody for for beta one + + align:start position:0% +opening book anybody for for beta one + + + align:start position:0% +opening book anybody for for beta one +they're gonna do an opening book for + + align:start position:0% +they're gonna do an opening book for + + + align:start position:0% +they're gonna do an opening book for +beta 1 or beta 2 hoo-hoo for beta 1 let + + align:start position:0% +beta 1 or beta 2 hoo-hoo for beta 1 let + + + align:start position:0% +beta 1 or beta 2 hoo-hoo for beta 1 let +me see okay beta 2 who wants to do an + + align:start position:0% +me see okay beta 2 who wants to do an + + + align:start position:0% +me see okay beta 2 who wants to do an +opening book beta for the final okay + + align:start position:0% +opening book beta for the final okay + + + align:start position:0% +opening book beta for the final okay +yeah okay so you know the idea here is + + align:start position:0% +yeah okay so you know the idea here is + + + align:start position:0% +yeah okay so you know the idea here is +to pre-compute best moves at the + + align:start position:0% +to pre-compute best moves at the + + + align:start position:0% +to pre-compute best moves at the +beginning of the game you know so that + + align:start position:0% +beginning of the game you know so that + + + align:start position:0% +beginning of the game you know so that +you know it's like well we know what the + + align:start position:0% +you know it's like well we know what the + + + align:start position:0% +you know it's like well we know what the +starting position is so what on I you + + align:start position:0% +starting position is so what on I you + + + align:start position:0% +starting position is so what on I you +know spend $1,000 or whatever on Amazon + + align:start position:0% +know spend $1,000 or whatever on Amazon + + + align:start position:0% +know spend $1,000 or whatever on Amazon +and and you know compute things to some + + align:start position:0% +and and you know compute things to some + + + align:start position:0% +and and you know compute things to some +ungodly ply right and see what the best + + align:start position:0% +ungodly ply right and see what the best + + + align:start position:0% +ungodly ply right and see what the best +moves are at the beginning of the game + + align:start position:0% +moves are at the beginning of the game + + + align:start position:0% +moves are at the beginning of the game +and put that into a book so I don't have + + align:start position:0% +and put that into a book so I don't have + + + align:start position:0% +and put that into a book so I don't have +to search those so that's the idea I + + align:start position:0% +to search those so that's the idea I + + + align:start position:0% +to search those so that's the idea I +think to begin with there are lower + + align:start position:0% +think to begin with there are lower + + + align:start position:0% +think to begin with there are lower +hanging fruit than then the opening book + + align:start position:0% +hanging fruit than then the opening book + + + align:start position:0% +hanging fruit than then the opening book +you know if you look at it you're going + + align:start position:0% +you know if you look at it you're going + + + align:start position:0% +you know if you look at it you're going +to be in opening book you know if you're + + align:start position:0% +to be in opening book you know if you're + + + align:start position:0% +to be in opening book you know if you're +lucky for you know six or eight moves + + align:start position:0% +lucky for you know six or eight moves + + + align:start position:0% +lucky for you know six or eight moves +and the games tend to last have you + + align:start position:0% +and the games tend to last have you + + + align:start position:0% +and the games tend to last have you +looked to see how long games last ten to + + align:start position:0% +looked to see how long games last ten to + + + align:start position:0% +looked to see how long games last ten to +last yeah what is it + + align:start position:0% +last yeah what is it + + + align:start position:0% +last yeah what is it +no most games don't go 4096 we don't let + + align:start position:0% +no most games don't go 4096 we don't let + + + align:start position:0% +no most games don't go 4096 we don't let +them go that long anyway so anybody's + + align:start position:0% +them go that long anyway so anybody's + + + align:start position:0% +them go that long anyway so anybody's +take a look statistically to see how + + align:start position:0% +take a look statistically to see how + + + align:start position:0% +take a look statistically to see how +long games are I think they tend to be + + align:start position:0% +long games are I think they tend to be + + + align:start position:0% +long games are I think they tend to be +like 40 or 50 moves okay I mean this + + align:start position:0% +like 40 or 50 moves okay I mean this + + + align:start position:0% +like 40 or 50 moves okay I mean this +year is different from other years + + align:start position:0% +year is different from other years + + + align:start position:0% +year is different from other years +because we have different rules but I + + align:start position:0% +because we have different rules but I + + + align:start position:0% +because we have different rules but I +think it's like 40 or 50 moves so you're + + align:start position:0% +think it's like 40 or 50 moves so you're + + + align:start position:0% +think it's like 40 or 50 moves so you're +not spending you know so you're doing + + align:start position:0% +not spending you know so you're doing + + + align:start position:0% +not spending you know so you're doing +something that will help you in 10% of + + align:start position:0% +something that will help you in 10% of + + + align:start position:0% +something that will help you in 10% of +the game where's there other places you + + align:start position:0% +the game where's there other places you + + + align:start position:0% +the game where's there other places you +could do it we're going to help you in + + align:start position:0% +could do it we're going to help you in + + + align:start position:0% +could do it we're going to help you in +the whole game nevertheless we've had + + align:start position:0% +the whole game nevertheless we've had + + + align:start position:0% +the whole game nevertheless we've had +teams that did a great job on opening + + align:start position:0% +teams that did a great job on opening + + + align:start position:0% +teams that did a great job on opening +books and clobbered people by you know + + align:start position:0% +books and clobbered people by you know + + + align:start position:0% +books and clobbered people by you know +by having a fantastic opening book okay + + align:start position:0% +by having a fantastic opening book okay + + + align:start position:0% +by having a fantastic opening book okay +it's actually cheaper to keep separate + + align:start position:0% +it's actually cheaper to keep separate + + + align:start position:0% +it's actually cheaper to keep separate +opening books for each side than to keep + + align:start position:0% +opening books for each side than to keep + + + align:start position:0% +opening books for each side than to keep +one opening book for both sides okay and + + align:start position:0% +one opening book for both sides okay and + + + align:start position:0% +one opening book for both sides okay and +in this game it's actually fairly easy + + align:start position:0% +in this game it's actually fairly easy + + + align:start position:0% +in this game it's actually fairly easy +to keep a symmetry thing and and + + align:start position:0% +to keep a symmetry thing and and + + + align:start position:0% +to keep a symmetry thing and and +basically have an one opening book that + + align:start position:0% +basically have an one opening book that + + + align:start position:0% +basically have an one opening book that +works for the side on move okay and that + + align:start position:0% +works for the side on move okay and that + + + align:start position:0% +works for the side on move okay and that +store that allows you to store you don't + + align:start position:0% +store that allows you to store you don't + + + align:start position:0% +store that allows you to store you don't +have to store you know if if I make a + + align:start position:0% +have to store you know if if I make a + + + align:start position:0% +have to store you know if if I make a +given move if I have a given position I + + align:start position:0% +given move if I have a given position I + + + align:start position:0% +given move if I have a given position I +only need in principle to store one + + align:start position:0% +only need in principle to store one + + + align:start position:0% +only need in principle to store one +answer for that position okay whereas + + align:start position:0% +answer for that position okay whereas + + + align:start position:0% +answer for that position okay whereas +then my opponent may make any number of + + align:start position:0% +then my opponent may make any number of + + + align:start position:0% +then my opponent may make any number of +moves for which then I only need to know + + align:start position:0% +moves for which then I only need to know + + + align:start position:0% +moves for which then I only need to know +one move what's my best move in that + + align:start position:0% +one move what's my best move in that + + + align:start position:0% +one move what's my best move in that +position so you can see that you're only + + align:start position:0% +position so you can see that you're only + + + align:start position:0% +position so you can see that you're only +having two you know you have once again + + align:start position:0% +having two you know you have once again + + + align:start position:0% +having two you know you have once again +this property that on my move I only + + align:start position:0% +this property that on my move I only + + + align:start position:0% +this property that on my move I only +need to have one move stored my + + align:start position:0% +need to have one move stored my + + + align:start position:0% +need to have one move stored my +opponent's moves I need to have all the + + align:start position:0% +opponent's moves I need to have all the + + + align:start position:0% +opponent's moves I need to have all the +moves stored okay and then my move I + + align:start position:0% +moves stored okay and then my move I + + + align:start position:0% +moves stored okay and then my move I +have one move story and that basically + + align:start position:0% +have one move story and that basically + + + align:start position:0% +have one move story and that basically +means you're effectively going twice the + + align:start position:0% +means you're effectively going twice the + + + align:start position:0% +means you're effectively going twice the +depth as if you kept all my moves and + + align:start position:0% +depth as if you kept all my moves and + + + align:start position:0% +depth as if you kept all my moves and +then all of the other opponent's moves + + align:start position:0% +then all of the other opponent's moves + + + align:start position:0% +then all of the other opponent's moves +and then all of those because when I do + + align:start position:0% +and then all of those because when I do + + + align:start position:0% +and then all of those because when I do +that it's like well why am i you know + + align:start position:0% +that it's like well why am i you know + + + align:start position:0% +that it's like well why am i you know +why do I need to know what the what the + + align:start position:0% +why do I need to know what the what the + + + align:start position:0% +why do I need to know what the what the +the best move so it's better to keep + + align:start position:0% +the best move so it's better to keep + + + align:start position:0% +the best move so it's better to keep +them separate when you build the opening + + align:start position:0% +them separate when you build the opening + + + align:start position:0% +them separate when you build the opening +book you'll store a lot less you have a + + align:start position:0% +book you'll store a lot less you have a + + + align:start position:0% +book you'll store a lot less you have a +lot smaller storage you'll be able to + + align:start position:0% +lot smaller storage you'll be able to + + + align:start position:0% +lot smaller storage you'll be able to +store + + align:start position:0% +store + + + align:start position:0% +store +more moves if you do that okay but I + + align:start position:0% +more moves if you do that okay but I + + + align:start position:0% +more moves if you do that okay but I +would say not necessarily the best the + + align:start position:0% +would say not necessarily the best the + + + align:start position:0% +would say not necessarily the best the +first thing I would go to optimize and + + align:start position:0% +first thing I would go to optimize and + + + align:start position:0% +first thing I would go to optimize and +but it's also the case that this is a + + align:start position:0% +but it's also the case that this is a + + + align:start position:0% +but it's also the case that this is a +place where you know one of the teams + + align:start position:0% +place where you know one of the teams + + + align:start position:0% +place where you know one of the teams +you know built a fabulous opening book + + align:start position:0% +you know built a fabulous opening book + + + align:start position:0% +you know built a fabulous opening book +one year and and one of the things about + + align:start position:0% +one year and and one of the things about + + + align:start position:0% +one year and and one of the things about +the opening book is it allows you also + + align:start position:0% +the opening book is it allows you also + + + align:start position:0% +the opening book is it allows you also +to sort of threshold and say you know in + + align:start position:0% +to sort of threshold and say you know in + + + align:start position:0% +to sort of threshold and say you know in +a given move I don't just have to have + + align:start position:0% +a given move I don't just have to have + + + align:start position:0% +a given move I don't just have to have +one move let me have three moves you + + align:start position:0% +one move let me have three moves you + + + align:start position:0% +one move let me have three moves you +know and pick randomly among them so + + align:start position:0% +know and pick randomly among them so + + + align:start position:0% +know and pick randomly among them so +that I'm not predictable what the team + + align:start position:0% +that I'm not predictable what the team + + + align:start position:0% +that I'm not predictable what the team +did that used the opening book is they + + align:start position:0% +did that used the opening book is they + + + align:start position:0% +did that used the opening book is they +observed that everybody was using words + + align:start position:0% +observed that everybody was using words + + + align:start position:0% +observed that everybody was using words +just searching from the beginning so + + align:start position:0% +just searching from the beginning so + + + align:start position:0% +just searching from the beginning so +they were all finding exactly the same + + align:start position:0% +they were all finding exactly the same + + + align:start position:0% +they were all finding exactly the same +moves at the beginning of the game and + + align:start position:0% +moves at the beginning of the game and + + + align:start position:0% +moves at the beginning of the game and +so they knew exactly what the path was + + align:start position:0% +so they knew exactly what the path was + + + align:start position:0% +so they knew exactly what the path was +that all the other programs were gonna + + align:start position:0% +that all the other programs were gonna + + + align:start position:0% +that all the other programs were gonna +follow and so they could make the best + + align:start position:0% +follow and so they could make the best + + + align:start position:0% +follow and so they could make the best +move on their move but if you have + + align:start position:0% +move on their move but if you have + + + align:start position:0% +move on their move but if you have +something that's got some randomness to + + align:start position:0% +something that's got some randomness to + + + align:start position:0% +something that's got some randomness to +it and there is a jitter in there who + + align:start position:0% +it and there is a jitter in there who + + + align:start position:0% +it and there is a jitter in there who +found the randomness the place we insert + + align:start position:0% +found the randomness the place we insert + + + align:start position:0% +found the randomness the place we insert +randomness and the code right so there + + align:start position:0% +randomness and the code right so there + + + align:start position:0% +randomness and the code right so there +was I think Zach had a had a comment on + + align:start position:0% +was I think Zach had a had a comment on + + + align:start position:0% +was I think Zach had a had a comment on +Piazza about that so there's a place in + + align:start position:0% +Piazza about that so there's a place in + + + align:start position:0% +Piazza about that so there's a place in +the code where we did there the amount + + align:start position:0% +the code where we did there the amount + + + align:start position:0% +the code where we did there the amount +so that you will get unpredictable + + align:start position:0% +so that you will get unpredictable + + + align:start position:0% +so that you will get unpredictable +results and that way you won't always + + align:start position:0% +results and that way you won't always + + + align:start position:0% +results and that way you won't always +play the same move okay just by changing + + align:start position:0% +play the same move okay just by changing + + + align:start position:0% +play the same move okay just by changing +things this is like you know a tent you + + align:start position:0% +things this is like you know a tent you + + + align:start position:0% +things this is like you know a tent you +know hundredths of a pawn value is like + + align:start position:0% +know hundredths of a pawn value is like + + + align:start position:0% +know hundredths of a pawn value is like +not very big and like who cares whether + + align:start position:0% +not very big and like who cares whether + + + align:start position:0% +not very big and like who cares whether +or not you know we have you know it's + + align:start position:0% +or not you know we have you know it's + + + align:start position:0% +or not you know we have you know it's +you know we're not actually these + + align:start position:0% +you know we're not actually these + + + align:start position:0% +you know we're not actually these +heuristics aren't measuring things so + + align:start position:0% +heuristics aren't measuring things so + + + align:start position:0% +heuristics aren't measuring things so +closely that we care about a tenth of + + align:start position:0% +closely that we care about a tenth of + + + align:start position:0% +closely that we care about a tenth of +book a hundredth of a pawn so you can + + align:start position:0% +book a hundredth of a pawn so you can + + + align:start position:0% +book a hundredth of a pawn so you can +dither things and have one move be + + align:start position:0% +dither things and have one move be + + + align:start position:0% +dither things and have one move be +better than another and not really + + align:start position:0% +better than another and not really + + + align:start position:0% +better than another and not really +affect the quality of the playing okay + + align:start position:0% +affect the quality of the playing okay + + + align:start position:0% +affect the quality of the playing okay +so it is a good idea to do something to + + align:start position:0% +so it is a good idea to do something to + + + align:start position:0% +so it is a good idea to do something to +not be so predictable okay but to build + + align:start position:0% +not be so predictable okay but to build + + + align:start position:0% +not be so predictable okay but to build +a full opening book it that's a lot of + + align:start position:0% +a full opening book it that's a lot of + + + align:start position:0% +a full opening book it that's a lot of +work for beta one okay for beta two in + + align:start position:0% +work for beta one okay for beta two in + + + align:start position:0% +work for beta one okay for beta two in +the final yeah you know you'll get to + + align:start position:0% +the final yeah you know you'll get to + + + align:start position:0% +the final yeah you know you'll get to +that point the next thing is iterative + + align:start position:0% +that point the next thing is iterative + + + align:start position:0% +that point the next thing is iterative +deepening to people understand how + + align:start position:0% +deepening to people understand how + + + align:start position:0% +deepening to people understand how +part of the search code works yeah no + + align:start position:0% +part of the search code works yeah no + + + align:start position:0% +part of the search code works yeah no +let me go over it okay so you can + + align:start position:0% +let me go over it okay so you can + + + align:start position:0% +let me go over it okay so you can +imagine saying I'm gonna search to depth + + align:start position:0% +imagine saying I'm gonna search to depth + + + align:start position:0% +imagine saying I'm gonna search to depth +D and in fact instead of just searching + + align:start position:0% +D and in fact instead of just searching + + + align:start position:0% +D and in fact instead of just searching +the epithelia depth one search if you + + align:start position:0% +the epithelia depth one search if you + + + align:start position:0% +the epithelia depth one search if you +look at the code there if there's a + + align:start position:0% +look at the code there if there's a + + + align:start position:0% +look at the code there if there's a +depth one search and we do a depth to + + align:start position:0% +depth one search and we do a depth to + + + align:start position:0% +depth one search and we do a depth to +search then we do a depth research then + + align:start position:0% +search then we do a depth research then + + + align:start position:0% +search then we do a depth research then +we do a depth for search and we keep + + align:start position:0% +we do a depth for search and we keep + + + align:start position:0% +we do a depth for search and we keep +doing that until our time control + + align:start position:0% +doing that until our time control + + + align:start position:0% +doing that until our time control +expires why is that a good strategy + + align:start position:0% + + + + align:start position:0% + +generally well first of all the amount + + align:start position:0% +generally well first of all the amount + + + align:start position:0% +generally well first of all the amount +of work with each depth is growing + + align:start position:0% +of work with each depth is growing + + + align:start position:0% +of work with each depth is growing +exponentially so you're only spending in + + align:start position:0% +exponentially so you're only spending in + + + align:start position:0% +exponentially so you're only spending in +principle a constant factor more work + + align:start position:0% +principle a constant factor more work + + + align:start position:0% +principle a constant factor more work +than you would if you search to depth D + + align:start position:0% +than you would if you search to depth D + + + align:start position:0% +than you would if you search to depth D +right off the bat okay but the important + + align:start position:0% +right off the bat okay but the important + + + align:start position:0% +right off the bat okay but the important +thing is that you can keep move or + + align:start position:0% +thing is that you can keep move or + + + align:start position:0% +thing is that you can keep move or +during information as you search deeper + + align:start position:0% +during information as you search deeper + + + align:start position:0% +during information as you search deeper +and the move ordering information + + align:start position:0% +and the move ordering information + + + align:start position:0% +and the move ordering information +remember we want this we want our + + align:start position:0% +remember we want this we want our + + + align:start position:0% +remember we want this we want our +searches to use best first move ordering + + align:start position:0% +searches to use best first move ordering + + + align:start position:0% +searches to use best first move ordering +so that we get all the cut-offs we can + + align:start position:0% +so that we get all the cut-offs we can + + + align:start position:0% +so that we get all the cut-offs we can +possibly get okay for pruning and so by + + align:start position:0% +possibly get okay for pruning and so by + + + align:start position:0% +possibly get okay for pruning and so by +searching it easier actually you end up + + align:start position:0% +searching it easier actually you end up + + + align:start position:0% +searching it easier actually you end up +with better move ordering okay because + + align:start position:0% +with better move ordering okay because + + + align:start position:0% +with better move ordering okay because +when you find the same position the in + + align:start position:0% +when you find the same position the in + + + align:start position:0% +when you find the same position the in +the transposition table you say oh well + + align:start position:0% +the transposition table you say oh well + + + align:start position:0% +the transposition table you say oh well +I didn't search it as deep as I need to + + align:start position:0% +I didn't search it as deep as I need to + + + align:start position:0% +I didn't search it as deep as I need to +search it now so I can't use the value + + align:start position:0% +search it now so I can't use the value + + + align:start position:0% +search it now so I can't use the value +that's in the transposition table for + + align:start position:0% +that's in the transposition table for + + + align:start position:0% +that's in the transposition table for +the position because it may be say you + + align:start position:0% +the position because it may be say you + + + align:start position:0% +the position because it may be say you +know I've searched something that's you + + align:start position:0% +know I've searched something that's you + + + align:start position:0% +know I've searched something that's you +know apply 8 in the transmission table + + align:start position:0% +know apply 8 in the transmission table + + + align:start position:0% +know apply 8 in the transmission table +but I've got a search to apply 9 not + + align:start position:0% +but I've got a search to apply 9 not + + + align:start position:0% +but I've got a search to apply 9 not +good enough a search but the value the + + align:start position:0% +good enough a search but the value the + + + align:start position:0% +good enough a search but the value the +the move that you've found at ply 8 + + align:start position:0% +the move that you've found at ply 8 + + + align:start position:0% +the move that you've found at ply 8 +that's probably a pretty good first move + + align:start position:0% +that's probably a pretty good first move + + + align:start position:0% +that's probably a pretty good first move +you know pretty good best move guess it + + align:start position:0% +you know pretty good best move guess it + + + align:start position:0% +you know pretty good best move guess it +best move okay so by doing iterative + + align:start position:0% +best move okay so by doing iterative + + + align:start position:0% +best move okay so by doing iterative +deepening you actually get the move + + align:start position:0% +deepening you actually get the move + + + align:start position:0% +deepening you actually get the move +ordering for all those intermediate + + align:start position:0% +ordering for all those intermediate + + + align:start position:0% +ordering for all those intermediate +positions you know really really really + + align:start position:0% +positions you know really really really + + + align:start position:0% +positions you know really really really +strongly because that transposition + + align:start position:0% +strongly because that transposition + + + align:start position:0% +strongly because that transposition +table is the very best information + + align:start position:0% +table is the very best information + + + align:start position:0% +table is the very best information +you've got for what the first move is + + align:start position:0% +you've got for what the first move is + + + align:start position:0% +you've got for what the first move is +what your best move is sorry ok and also + + align:start position:0% +what your best move is sorry ok and also + + + align:start position:0% +what your best move is sorry ok and also +as I mentioned it's a good mechanism for + + align:start position:0% +as I mentioned it's a good mechanism for + + + align:start position:0% +as I mentioned it's a good mechanism for +time control is that clear + + align:start position:0% +time control is that clear + + + align:start position:0% +time control is that clear +so that's why you bother is one of these + + align:start position:0% +so that's why you bother is one of these + + + align:start position:0% +so that's why you bother is one of these +things that looks like it's redundant + + align:start position:0% +things that looks like it's redundant + + + align:start position:0% +things that looks like it's redundant +why are you searching if you're gonna + + align:start position:0% +why are you searching if you're gonna + + + align:start position:0% +why are you searching if you're gonna +search the depth dy search the depth D + + align:start position:0% +search the depth dy search the depth D + + + align:start position:0% +search the depth dy search the depth D +minus one you need to do that as part of + + align:start position:0% +minus one you need to do that as part of + + + align:start position:0% +minus one you need to do that as part of +depth e well no because you're gonna get + + align:start position:0% +depth e well no because you're gonna get + + + align:start position:0% +depth e well no because you're gonna get +move ordering information this can be + + align:start position:0% +move ordering information this can be + + + align:start position:0% +move ordering information this can be +really valuable when you search the + + align:start position:0% +really valuable when you search the + + + align:start position:0% +really valuable when you search the +depth key minus one so when you search + + align:start position:0% +depth key minus one so when you search + + + align:start position:0% +depth key minus one so when you search +the depth D you've got much better + + align:start position:0% +the depth D you've got much better + + + align:start position:0% +the depth D you've got much better +pruning than if you just went straight + + align:start position:0% +pruning than if you just went straight + + + align:start position:0% +pruning than if you just went straight +to depth D and had no information about + + align:start position:0% +to depth D and had no information about + + + align:start position:0% +to depth D and had no information about +the move ordering does that make sense + + align:start position:0% + + + + align:start position:0% + +in game database so here's the idea if + + align:start position:0% +in game database so here's the idea if + + + align:start position:0% +in game database so here's the idea if +there's a few enough pieces on the board + + align:start position:0% +there's a few enough pieces on the board + + + align:start position:0% +there's a few enough pieces on the board +you can pre-compute the outcomes and + + align:start position:0% +you can pre-compute the outcomes and + + + align:start position:0% +you can pre-compute the outcomes and +store them in a database okay so so for + + align:start position:0% +store them in a database okay so so for + + + align:start position:0% +store them in a database okay so so for +example the most common database to come + + align:start position:0% +example the most common database to come + + + align:start position:0% +example the most common database to come +up with is the King versus King database + + align:start position:0% +up with is the King versus King database + + + align:start position:0% +up with is the King versus King database +okay so if you do King versus King that + + align:start position:0% +okay so if you do King versus King that + + + align:start position:0% +okay so if you do King versus King that +means that it's not that you expect the + + align:start position:0% +means that it's not that you expect the + + + align:start position:0% +means that it's not that you expect the +game will end up as King versus King + + align:start position:0% +game will end up as King versus King + + + align:start position:0% +game will end up as King versus King +it's that you're gonna encounter that in + + align:start position:0% +it's that you're gonna encounter that in + + + align:start position:0% +it's that you're gonna encounter that in +the search it'd be nice to know who has + + align:start position:0% +the search it'd be nice to know who has + + + align:start position:0% +the search it'd be nice to know who has +the win if your King versus King now the + + align:start position:0% +the win if your King versus King now the + + + align:start position:0% +the win if your King versus King now the +code actually plays optimally for King + + align:start position:0% +code actually plays optimally for King + + + align:start position:0% +code actually plays optimally for King +versus King okay the code we gave you + + align:start position:0% +versus King okay the code we gave you + + + align:start position:0% +versus King okay the code we gave you +will we'll do we'll play the King versus + + align:start position:0% +will we'll do we'll play the King versus + + + align:start position:0% +will we'll do we'll play the King versus +King you know perfectly well and in fact + + align:start position:0% +King you know perfectly well and in fact + + + align:start position:0% +King you know perfectly well and in fact +there's just two heuristics that are + + align:start position:0% +there's just two heuristics that are + + + align:start position:0% +there's just two heuristics that are +responsible for that one is the the + + align:start position:0% +responsible for that one is the the + + + align:start position:0% +responsible for that one is the the +lives called K aggressive heuristic and + + align:start position:0% +lives called K aggressive heuristic and + + + align:start position:0% +lives called K aggressive heuristic and +the other one is which basically makes + + align:start position:0% +the other one is which basically makes + + + align:start position:0% +the other one is which basically makes +you move towards your opponent and the + + align:start position:0% +you move towards your opponent and the + + + align:start position:0% +you move towards your opponent and the +other one is the the K face heuristic + + align:start position:0% +other one is the the K face heuristic + + + align:start position:0% +other one is the the K face heuristic +which makes you point towards your + + align:start position:0% +which makes you point towards your + + + align:start position:0% +which makes you point towards your +opponent and those two things turn out + + align:start position:0% +opponent and those two things turn out + + + align:start position:0% +opponent and those two things turn out +to do a pretty good job of when there's + + align:start position:0% +to do a pretty good job of when there's + + + align:start position:0% +to do a pretty good job of when there's +when there's two kings and playing they + + align:start position:0% +when there's two kings and playing they + + + align:start position:0% +when there's two kings and playing they +go through this little any immed it'd + + align:start position:0% +go through this little any immed it'd + + + align:start position:0% +go through this little any immed it'd +everybody do that by hand by the way do + + align:start position:0% +everybody do that by hand by the way do + + + align:start position:0% +everybody do that by hand by the way do +you play King versus King so a really + + align:start position:0% +you play King versus King so a really + + + align:start position:0% +you play King versus King so a really +good idea if you want to understand the + + align:start position:0% +good idea if you want to understand the + + + align:start position:0% +good idea if you want to understand the +game is just is just go and do a king + + align:start position:0% +game is just is just go and do a king + + + align:start position:0% +game is just is just go and do a king +versus King version of the of the game + + align:start position:0% +versus King version of the of the game + + + align:start position:0% +versus King version of the of the game +get an eight by eight chessboard and + + align:start position:0% +get an eight by eight chessboard and + + + align:start position:0% +get an eight by eight chessboard and +just put down two tokens that you call + + align:start position:0% +just put down two tokens that you call + + + align:start position:0% +just put down two tokens that you call +our Kings that have orientations and + + align:start position:0% +our Kings that have orientations and + + + align:start position:0% +our Kings that have orientations and +then just just the two of you and a + + align:start position:0% +then just just the two of you and a + + + align:start position:0% +then just just the two of you and a +friend just try to + + align:start position:0% +friend just try to + + + align:start position:0% +friend just try to +see if you you know one can make the + + align:start position:0% +see if you you know one can make the + + + align:start position:0% +see if you you know one can make the +other and you'll see that it goes + + align:start position:0% +other and you'll see that it goes + + + align:start position:0% +other and you'll see that it goes +through a very ritualistic type of + + align:start position:0% +through a very ritualistic type of + + + align:start position:0% +through a very ritualistic type of +behavior which ends up with one of the + + align:start position:0% +behavior which ends up with one of the + + + align:start position:0% +behavior which ends up with one of the +Kings being mated so it's nice to know + + align:start position:0% +Kings being mated so it's nice to know + + + align:start position:0% +Kings being mated so it's nice to know +which one it's going to be so if you + + align:start position:0% +which one it's going to be so if you + + + align:start position:0% +which one it's going to be so if you +encounter that but here's the question + + align:start position:0% +encounter that but here's the question + + + align:start position:0% +encounter that but here's the question +is how many games actually make it to an + + align:start position:0% +is how many games actually make it to an + + + align:start position:0% +is how many games actually make it to an +end game once again you have to look at + + align:start position:0% +end game once again you have to look at + + + align:start position:0% +end game once again you have to look at +what the odds are there because if games + + align:start position:0% +what the odds are there because if games + + + align:start position:0% +what the odds are there because if games +are ending in the middle game there may + + align:start position:0% +are ending in the middle game there may + + + align:start position:0% +are ending in the middle game there may +not be any need to search all the way to + + align:start position:0% +not be any need to search all the way to + + + align:start position:0% +not be any need to search all the way to +the end game okay so so that's something + + align:start position:0% +the end game okay so so that's something + + + align:start position:0% +the end game okay so so that's something +that you need to weigh okay now if you + + align:start position:0% +that you need to weigh okay now if you + + + align:start position:0% +that you need to weigh okay now if you +do an endgame database it doesn't + + align:start position:0% +do an endgame database it doesn't + + + align:start position:0% +do an endgame database it doesn't +suffice to just or win loss or draw for + + align:start position:0% +suffice to just or win loss or draw for + + + align:start position:0% +suffice to just or win loss or draw for +a position and the reason is because you + + align:start position:0% +a position and the reason is because you + + + align:start position:0% +a position and the reason is because you +can get into a situation where you've + + align:start position:0% +can get into a situation where you've + + + align:start position:0% +can get into a situation where you've +got a winning position and then you say + + align:start position:0% +got a winning position and then you say + + + align:start position:0% +got a winning position and then you say +okay well let me move to another winning + + align:start position:0% +okay well let me move to another winning + + + align:start position:0% +okay well let me move to another winning +position and another winning position + + align:start position:0% +position and another winning position + + + align:start position:0% +position and another winning position +and another winning position oh and I'm + + align:start position:0% +and another winning position oh and I'm + + + align:start position:0% +and another winning position oh and I'm +back it to my original winning position + + align:start position:0% +back it to my original winning position + + + align:start position:0% +back it to my original winning position +and I just keep going around in a circle + + align:start position:0% +and I just keep going around in a circle + + + align:start position:0% +and I just keep going around in a circle +always in a winning position never + + align:start position:0% +always in a winning position never + + + align:start position:0% +always in a winning position never +moving towards the win okay and that of + + align:start position:0% +moving towards the win okay and that of + + + align:start position:0% +moving towards the win okay and that of +course will end up in a draw so you need + + align:start position:0% +course will end up in a draw so you need + + + align:start position:0% +course will end up in a draw so you need +to know which direction do you go for + + align:start position:0% +to know which direction do you go for + + + align:start position:0% +to know which direction do you go for +the winning position so the typical + + align:start position:0% +the winning position so the typical + + + align:start position:0% +the winning position so the typical +thing you do there is you keep the + + align:start position:0% +thing you do there is you keep the + + + align:start position:0% +thing you do there is you keep the +distance to mate to avoid cycling so you + + align:start position:0% +distance to mate to avoid cycling so you + + + align:start position:0% +distance to mate to avoid cycling so you +go from instead of keeping just a + + align:start position:0% +go from instead of keeping just a + + + align:start position:0% +go from instead of keeping just a +boolean value you say here's my distance + + align:start position:0% +boolean value you say here's my distance + + + align:start position:0% +boolean value you say here's my distance +to winning okay my distance to winning + + align:start position:0% +to winning okay my distance to winning + + + align:start position:0% +to winning okay my distance to winning +is six now when I'm searching I don't + + align:start position:0% +is six now when I'm searching I don't + + + align:start position:0% +is six now when I'm searching I don't +want to go a distance to winning that + + align:start position:0% +want to go a distance to winning that + + + align:start position:0% +want to go a distance to winning that +seven or six I want to go to a distance + + align:start position:0% +seven or six I want to go to a distance + + + align:start position:0% +seven or six I want to go to a distance +of winning that's five when I make my + + align:start position:0% +of winning that's five when I make my + + + align:start position:0% +of winning that's five when I make my +move okay + + align:start position:0% +move okay + + + align:start position:0% +move okay +so it's very important to make sure that + + align:start position:0% +so it's very important to make sure that + + + align:start position:0% +so it's very important to make sure that +you maintain the distance in order to + + align:start position:0% +you maintain the distance in order to + + + align:start position:0% +you maintain the distance in order to +avoid cycling you know quiescence search + + align:start position:0% +avoid cycling you know quiescence search + + + align:start position:0% +avoid cycling you know quiescence search +we talked about quiescence which is you + + align:start position:0% +we talked about quiescence which is you + + + align:start position:0% +we talked about quiescence which is you +know to make sure that when you're doing + + align:start position:0% +know to make sure that when you're doing + + + align:start position:0% +know to make sure that when you're doing +the evaluation you're not in the middle + + align:start position:0% +the evaluation you're not in the middle + + + align:start position:0% +the evaluation you're not in the middle +of an exchange you know so you zap their + + align:start position:0% +of an exchange you know so you zap their + + + align:start position:0% +of an exchange you know so you zap their +pawn they're gonna zap your pawn or + + align:start position:0% +pawn they're gonna zap your pawn or + + + align:start position:0% +pawn they're gonna zap your pawn or +maybe even zap your king okay and you + + align:start position:0% +maybe even zap your king okay and you + + + align:start position:0% +maybe even zap your king okay and you +don't want to evaluate in the middle + + align:start position:0% +don't want to evaluate in the middle + + + align:start position:0% +don't want to evaluate in the middle +there and so the idea of quiescence is + + align:start position:0% +there and so the idea of quiescence is + + + align:start position:0% +there and so the idea of quiescence is +that when you're done with the regular + + align:start position:0% +that when you're done with the regular + + + align:start position:0% +that when you're done with the regular +search you just play off moves that + + align:start position:0% +search you just play off moves that + + + align:start position:0% +search you just play off moves that +involve captures and + + align:start position:0% +involve captures and + + + align:start position:0% +involve captures and +you evaluate the position okay so that's + + align:start position:0% +you evaluate the position okay so that's + + + align:start position:0% +you evaluate the position okay so that's +quieting the position okay makes sense + + align:start position:0% + + + + align:start position:0% + +another heuristic there is no move + + align:start position:0% +another heuristic there is no move + + + align:start position:0% +another heuristic there is no move +pruning in most positions there's always + + align:start position:0% +pruning in most positions there's always + + + align:start position:0% +pruning in most positions there's always +something better to do than nothing so + + align:start position:0% +something better to do than nothing so + + + align:start position:0% +something better to do than nothing so +sitting still is usually not as good as + + align:start position:0% +sitting still is usually not as good as + + + align:start position:0% +sitting still is usually not as good as +actually making a move okay + + align:start position:0% +actually making a move okay + + + align:start position:0% +actually making a move okay +and so the idea is suppose that I can + + align:start position:0% +and so the idea is suppose that I can + + + align:start position:0% +and so the idea is suppose that I can +forfeit my move and search a shallower + + align:start position:0% +forfeit my move and search a shallower + + + align:start position:0% +forfeit my move and search a shallower +depth and I still have the best position + + align:start position:0% +depth and I still have the best position + + + align:start position:0% +depth and I still have the best position +okay then I still am winning well then + + align:start position:0% +okay then I still am winning well then + + + align:start position:0% +okay then I still am winning well then +and it generates a cutoff then why + + align:start position:0% +and it generates a cutoff then why + + + align:start position:0% +and it generates a cutoff then why +bother exploring any other moves I + + align:start position:0% +bother exploring any other moves I + + + align:start position:0% +bother exploring any other moves I +probably am in a really good position + + align:start position:0% +probably am in a really good position + + + align:start position:0% +probably am in a really good position +here okay and if if I don't manage to + + align:start position:0% +here okay and if if I don't manage to + + + align:start position:0% +here okay and if if I don't manage to +get a cut off from the no move then I + + align:start position:0% +get a cut off from the no move then I + + + align:start position:0% +get a cut off from the no move then I +you know then I do the full the full + + align:start position:0% +you know then I do the full the full + + + align:start position:0% +you know then I do the full the full +depth search okay so so the place this + + align:start position:0% +depth search okay so so the place this + + + align:start position:0% +depth search okay so so the place this +is dangerous is in zoogs wang in chess + + align:start position:0% +is dangerous is in zoogs wang in chess + + + align:start position:0% +is dangerous is in zoogs wang in chess +it's called zoogs along situations so + + align:start position:0% +it's called zoogs along situations so + + + align:start position:0% +it's called zoogs along situations so +slugs along a situation where everything + + align:start position:0% +slugs along a situation where everything + + + align:start position:0% +slugs along a situation where everything +is fine but if you have to make a move + + align:start position:0% +is fine but if you have to make a move + + + align:start position:0% +is fine but if you have to make a move +you lose so usually making and having + + align:start position:0% +you lose so usually making and having + + + align:start position:0% +you lose so usually making and having +the advantage of a move that's called + + align:start position:0% +the advantage of a move that's called + + + align:start position:0% +the advantage of a move that's called +the initiative in chess and that's a + + align:start position:0% +the initiative in chess and that's a + + + align:start position:0% +the initiative in chess and that's a +good thing you want the initiative you + + align:start position:0% +good thing you want the initiative you + + + align:start position:0% +good thing you want the initiative you +want to have the extra move over your + + align:start position:0% +want to have the extra move over your + + + align:start position:0% +want to have the extra move over your +opponent but there are some situations + + align:start position:0% +opponent but there are some situations + + + align:start position:0% +opponent but there are some situations +where if you move you lose okay and so + + align:start position:0% +where if you move you lose okay and so + + + align:start position:0% +where if you move you lose okay and so +you want to make sure you don't have a + + align:start position:0% +you want to make sure you don't have a + + + align:start position:0% +you want to make sure you don't have a +Zhuge Liang situation I don't actually + + align:start position:0% +Zhuge Liang situation I don't actually + + + align:start position:0% +Zhuge Liang situation I don't actually +know if there's a Zhuge Liang situation + + align:start position:0% +know if there's a Zhuge Liang situation + + + align:start position:0% +know if there's a Zhuge Liang situation +in lesser chess okay so it's if somebody + + align:start position:0% +in lesser chess okay so it's if somebody + + + align:start position:0% +in lesser chess okay so it's if somebody +comes up with one I'd be interested to + + align:start position:0% +comes up with one I'd be interested to + + + align:start position:0% +comes up with one I'd be interested to +see that you know where if you had to + + align:start position:0% +see that you know where if you had to + + + align:start position:0% +see that you know where if you had to +move I lose but if I sits there so what + + align:start position:0% +move I lose but if I sits there so what + + + align:start position:0% +move I lose but if I sits there so what +in chess what they do is in the end game + + align:start position:0% +in chess what they do is in the end game + + + align:start position:0% +in chess what they do is in the end game +that's when zoogs lines come up they + + align:start position:0% +that's when zoogs lines come up they + + + align:start position:0% +that's when zoogs lines come up they +turn off the null move pruning so is + + align:start position:0% +turn off the null move pruning so is + + + align:start position:0% +turn off the null move pruning so is +this clear what null move does for you + + align:start position:0% +this clear what null move does for you + + + align:start position:0% +this clear what null move does for you +what what's going on there so I see some + + align:start position:0% +what what's going on there so I see some + + + align:start position:0% +what what's going on there so I see some +people who are quizzical anybody want to + + align:start position:0% +people who are quizzical anybody want to + + + align:start position:0% +people who are quizzical anybody want to +ask a question I see some people hide + + align:start position:0% +ask a question I see some people hide + + + align:start position:0% +ask a question I see some people hide +with sort of quizzical looks on their + + align:start position:0% +with sort of quizzical looks on their + + + align:start position:0% +with sort of quizzical looks on their +faces + + align:start position:0% +faces + + + align:start position:0% +faces +okay the idea is for no movies my + + align:start position:0% +okay the idea is for no movies my + + + align:start position:0% +okay the idea is for no movies my +position is so good okay that even if I + + align:start position:0% +position is so good okay that even if I + + + align:start position:0% +position is so good okay that even if I +do nothing I still win okay so I don't + + align:start position:0% +do nothing I still win okay so I don't + + + align:start position:0% +do nothing I still win okay so I don't +want to search anymore in this part of + + align:start position:0% +want to search anymore in this part of + + + align:start position:0% +want to search anymore in this part of +it because you're you know I get a beta + + align:start position:0% +it because you're you know I get a beta + + + align:start position:0% +it because you're you know I get a beta +cutoff you're not gonna let me make this + + align:start position:0% +cutoff you're not gonna let me make this + + + align:start position:0% +cutoff you're not gonna let me make this +move that the move that got me here yeah + + align:start position:0% +move that the move that got me here yeah + + + align:start position:0% +move that the move that got me here yeah +question oh did you really + + align:start position:0% +question oh did you really + + + align:start position:0% +question oh did you really +yeah okay that was it okay good yeah my + + align:start position:0% +yeah okay that was it okay good yeah my + + + align:start position:0% +yeah okay that was it okay good yeah my +move is so good I could I can do nothing + + align:start position:0% +move is so good I could I can do nothing + + + align:start position:0% +move is so good I could I can do nothing +and I still win okay and so why bother + + align:start position:0% +and I still win okay and so why bother + + + align:start position:0% +and I still win okay and so why bother +you know let me verify that without + + align:start position:0% +you know let me verify that without + + + align:start position:0% +you know let me verify that without +necessary doing as deep a search so no + + align:start position:0% +necessary doing as deep a search so no + + + align:start position:0% +necessary doing as deep a search so no +move is fairly cheap to do and it you + + align:start position:0% +move is fairly cheap to do and it you + + + align:start position:0% +move is fairly cheap to do and it you +know often results in you know for in a + + align:start position:0% +know often results in you know for in a + + + align:start position:0% +know often results in you know for in a +lot of positions for cutoff and if I + + align:start position:0% +lot of positions for cutoff and if I + + + align:start position:0% +lot of positions for cutoff and if I +don't get a cutoff then I just do the + + align:start position:0% +don't get a cutoff then I just do the + + + align:start position:0% +don't get a cutoff then I just do the +normal search okay this is a pretty + + align:start position:0% +normal search okay this is a pretty + + + align:start position:0% +normal search okay this is a pretty +complicated piece of code isn't it okay + + align:start position:0% +complicated piece of code isn't it okay + + + align:start position:0% +complicated piece of code isn't it okay +you know pretty complicated okay + + align:start position:0% +you know pretty complicated okay + + + align:start position:0% +you know pretty complicated okay +there are other situations we mentioned + + align:start position:0% +there are other situations we mentioned + + + align:start position:0% +there are other situations we mentioned +killers okay + + align:start position:0% +killers okay + + + align:start position:0% +killers okay +there's also move extensions so typical + + align:start position:0% +there's also move extensions so typical + + + align:start position:0% +there's also move extensions so typical +move extensions that people look at is + + align:start position:0% +move extensions that people look at is + + + align:start position:0% +move extensions that people look at is +you grant an extra ply in chess if the + + align:start position:0% +you grant an extra ply in chess if the + + + align:start position:0% +you grant an extra ply in chess if the +king is in check or for certain captures + + align:start position:0% +king is in check or for certain captures + + + align:start position:0% +king is in check or for certain captures +or if you have a forced move so suppose + + align:start position:0% +or if you have a forced move so suppose + + + align:start position:0% +or if you have a forced move so suppose +you have a move and it's the only move + + align:start position:0% +you have a move and it's the only move + + + align:start position:0% +you have a move and it's the only move +you can make then don't count that as + + align:start position:0% +you can make then don't count that as + + + align:start position:0% +you can make then don't count that as +apply so you can search deeper along + + align:start position:0% +apply so you can search deeper along + + + align:start position:0% +apply so you can search deeper along +lines where they're forced moves that's + + align:start position:0% +lines where they're forced moves that's + + + align:start position:0% +lines where they're forced moves that's +what they do in chess lie search s not + + align:start position:0% +what they do in chess lie search s not + + + align:start position:0% +what they do in chess lie search s not +quite so clear what you do okay which + + align:start position:0% +quite so clear what you do okay which + + + align:start position:0% +quite so clear what you do okay which +ones you would do extensions for okay + + align:start position:0% + + + + align:start position:0% + +because it it's rare that you have just + + align:start position:0% +because it it's rare that you have just + + + align:start position:0% +because it it's rare that you have just +one move in in lesser chess compared to + + align:start position:0% +one move in in lesser chess compared to + + + align:start position:0% +one move in in lesser chess compared to +in in Chester where you ever by force + + align:start position:0% +in in Chester where you ever by force + + + align:start position:0% +in in Chester where you ever by force +move it's like if you don't do this + + align:start position:0% +move it's like if you don't do this + + + align:start position:0% +move it's like if you don't do this +you're going to get captured or you know + + align:start position:0% +you're going to get captured or you know + + + align:start position:0% +you're going to get captured or you know +made it or what have you + + align:start position:0% +made it or what have you + + + align:start position:0% +made it or what have you +okay so that may come up in less your + + align:start position:0% +okay so that may come up in less your + + + align:start position:0% +okay so that may come up in less your +chest but anyway it's it's something to + + align:start position:0% +chest but anyway it's it's something to + + + align:start position:0% +chest but anyway it's it's something to +think about + + align:start position:0% +think about + + + align:start position:0% +think about +so the transposition table so we talk + + align:start position:0% +so the transposition table so we talk + + + align:start position:0% +so the transposition table so we talk +about this as a search tree but it's + + align:start position:0% +about this as a search tree but it's + + + align:start position:0% +about this as a search tree but it's +really a dag because I can get to the + + align:start position:0% +really a dag because I can get to the + + + align:start position:0% +really a dag because I can get to the +same position by transposing moves you + + align:start position:0% +same position by transposing moves you + + + align:start position:0% +same position by transposing moves you +know this guy does a this guy does B + + align:start position:0% +know this guy does a this guy does B + + + align:start position:0% +know this guy does a this guy does B +this guy does C this guy does D I may + + align:start position:0% +this guy does C this guy does D I may + + + align:start position:0% +this guy does C this guy does D I may +get it's the same thing by doing you + + align:start position:0% +get it's the same thing by doing you + + + align:start position:0% +get it's the same thing by doing you +know a d c b I transpose those two moves + + align:start position:0% +know a d c b I transpose those two moves + + + align:start position:0% +know a d c b I transpose those two moves +and I get to exactly the same position + + align:start position:0% +and I get to exactly the same position + + + align:start position:0% +and I get to exactly the same position +okay and so I'd like not to search that + + align:start position:0% +okay and so I'd like not to search that + + + align:start position:0% +okay and so I'd like not to search that +position again if I've seen it and + + align:start position:0% +position again if I've seen it and + + + align:start position:0% +position again if I've seen it and +that's what the transposition does + + align:start position:0% +that's what the transposition does + + + align:start position:0% +that's what the transposition does +there's a quality score that is in the + + align:start position:0% +there's a quality score that is in the + + + align:start position:0% +there's a quality score that is in the +transposition table that tells you how + + align:start position:0% +transposition table that tells you how + + + align:start position:0% +transposition table that tells you how +good a move you've made and the quality + + align:start position:0% +good a move you've made and the quality + + + align:start position:0% +good a move you've made and the quality +is essentially the depth that you had to + + align:start position:0% +is essentially the depth that you had to + + + align:start position:0% +is essentially the depth that you had to +search in order to establish the value + + align:start position:0% +search in order to establish the value + + + align:start position:0% +search in order to establish the value +that's stored in the transposition table + + align:start position:0% +that's stored in the transposition table + + + align:start position:0% +that's stored in the transposition table +and so you don't want to use something + + align:start position:0% +and so you don't want to use something + + + align:start position:0% +and so you don't want to use something +of too low quality when you're searching + + align:start position:0% +of too low quality when you're searching + + + align:start position:0% +of too low quality when you're searching +if you have to search the depth D + + align:start position:0% +if you have to search the depth D + + + align:start position:0% +if you have to search the depth D +something of quality D minus 1 is not + + align:start position:0% +something of quality D minus 1 is not + + + align:start position:0% +something of quality D minus 1 is not +good enough ok because otherwise you'll + + align:start position:0% +good enough ok because otherwise you'll + + + align:start position:0% +good enough ok because otherwise you'll +not be searching you know the full tree + + align:start position:0% +not be searching you know the full tree + + + align:start position:0% +not be searching you know the full tree +but something typically that is deeper + + align:start position:0% +but something typically that is deeper + + + align:start position:0% +but something typically that is deeper +you know certainly you know if you if if + + align:start position:0% +you know certainly you know if you if if + + + align:start position:0% +you know certainly you know if you if if +I'm looking at depth D and I find + + align:start position:0% +I'm looking at depth D and I find + + + align:start position:0% +I'm looking at depth D and I find +something in transposition table that's + + align:start position:0% +something in transposition table that's + + + align:start position:0% +something in transposition table that's +d plus 1 or D plus 2 that's great to use + + align:start position:0% +d plus 1 or D plus 2 that's great to use + + + align:start position:0% +d plus 1 or D plus 2 that's great to use +that just gave me an even deeper view of + + align:start position:0% +that just gave me an even deeper view of + + + align:start position:0% +that just gave me an even deeper view of +what's behind that move okay and so if + + align:start position:0% +what's behind that move okay and so if + + + align:start position:0% +what's behind that move okay and so if +you look at the logic there you'll see + + align:start position:0% +you look at the logic there you'll see + + + align:start position:0% +you look at the logic there you'll see +that that's how they do it it's very + + align:start position:0% +that that's how they do it it's very + + + align:start position:0% +that that's how they do it it's very +tricky one of the things that's tricky + + align:start position:0% +tricky one of the things that's tricky + + + align:start position:0% +tricky one of the things that's tricky +is when you find a mate how you store + + align:start position:0% +is when you find a mate how you store + + + align:start position:0% +is when you find a mate how you store +that in the transposition table and + + align:start position:0% +that in the transposition table and + + + align:start position:0% +that in the transposition table and +you'll see there's special code for + + align:start position:0% +you'll see there's special code for + + + align:start position:0% +you'll see there's special code for +handling mate positions and the reason + + align:start position:0% +handling mate positions and the reason + + + align:start position:0% +handling mate positions and the reason +is because what you're interested in + + align:start position:0% +is because what you're interested in + + + align:start position:0% +is because what you're interested in +doing when you find a mate is knowing + + align:start position:0% +doing when you find a mate is knowing + + + align:start position:0% +doing when you find a mate is knowing +your distance to mate but not from that + + align:start position:0% +your distance to mate but not from that + + + align:start position:0% +your distance to mate but not from that +position the distance our mate from the + + align:start position:0% +position the distance our mate from the + + + align:start position:0% +position the distance our mate from the +root of your search okay so for example + + align:start position:0% +root of your search okay so for example + + + align:start position:0% +root of your search okay so for example +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +you know let's say this is the root of + + align:start position:0% +you know let's say this is the root of + + + align:start position:0% +you know let's say this is the root of +my searched and I searched down to a + + align:start position:0% +my searched and I searched down to a + + + align:start position:0% +my searched and I searched down to a +given point and now I do a lookup in the + + align:start position:0% +given point and now I do a lookup in the + + + align:start position:0% +given point and now I do a lookup in the +transposition table and I discovered + + align:start position:0% +transposition table and I discovered + + + align:start position:0% +transposition table and I discovered +that there's a mate in five here okay + + align:start position:0% +that there's a mate in five here okay + + + align:start position:0% +that there's a mate in five here okay +and this is let's say let's I have + + align:start position:0% +and this is let's say let's I have + + + align:start position:0% +and this is let's say let's I have +searched nine-ply or something okay well + + align:start position:0% +searched nine-ply or something okay well + + + align:start position:0% +searched nine-ply or something okay well +if I store that this is a mate in five + + align:start position:0% +if I store that this is a mate in five + + + align:start position:0% +if I store that this is a mate in five +and I store the value for mate and five + + align:start position:0% +and I store the value for mate and five + + + align:start position:0% +and I store the value for mate and five +then if it makes it up to the top here + + align:start position:0% +then if it makes it up to the top here + + + align:start position:0% +then if it makes it up to the top here +it thinks there's a mate and five but + + align:start position:0% +it thinks there's a mate and five but + + + align:start position:0% +it thinks there's a mate and five but +there isn't a mate in five there's a + + align:start position:0% +there isn't a mate in five there's a + + + align:start position:0% +there isn't a mate in five there's a +mate in 14 okay so when you look it up + + align:start position:0% +mate in 14 okay so when you look it up + + + align:start position:0% +mate in 14 okay so when you look it up +and you discover there's a mate and five + + align:start position:0% +and you discover there's a mate and five + + + align:start position:0% +and you discover there's a mate and five +in the table you have to do a little bit + + align:start position:0% +in the table you have to do a little bit + + + align:start position:0% +in the table you have to do a little bit +of a calculation to translate that into + + align:start position:0% +of a calculation to translate that into + + + align:start position:0% +of a calculation to translate that into +being a mate in in 14 as the value + + align:start position:0% +being a mate in in 14 as the value + + + align:start position:0% +being a mate in in 14 as the value +that's going to be used here rather than + + align:start position:0% +that's going to be used here rather than + + + align:start position:0% +that's going to be used here rather than +a mate in five does that make sense so + + align:start position:0% +a mate in five does that make sense so + + + align:start position:0% +a mate in five does that make sense so +you'll see that's the logic that's in + + align:start position:0% +you'll see that's the logic that's in + + + align:start position:0% +you'll see that's the logic that's in +there for dealing with mates so mate + + align:start position:0% +there for dealing with mates so mate + + + align:start position:0% +there for dealing with mates so mate +basically takes a very large number way + + align:start position:0% +basically takes a very large number way + + + align:start position:0% +basically takes a very large number way +larger than all the material on the + + align:start position:0% +larger than all the material on the + + + align:start position:0% +larger than all the material on the +board and then it subtracts what your + + align:start position:0% +board and then it subtracts what your + + + align:start position:0% +board and then it subtracts what your +number of ply is to get to get to me so + + align:start position:0% +number of ply is to get to get to me so + + + align:start position:0% +number of ply is to get to get to me so +some big number + + align:start position:0% +some big number + + + align:start position:0% +some big number +you know I don't know 32,000 or + + align:start position:0% +you know I don't know 32,000 or + + + align:start position:0% +you know I don't know 32,000 or +something minus the depth to me is what + + align:start position:0% +something minus the depth to me is what + + + align:start position:0% +something minus the depth to me is what +you is what is how you represent a mate + + align:start position:0% +you is what is how you represent a mate + + + align:start position:0% +you is what is how you represent a mate +you know so some very very big number + + align:start position:0% +you know so some very very big number + + + align:start position:0% +you know so some very very big number +and and then minus the minus the depth + + align:start position:0% +and and then minus the minus the depth + + + align:start position:0% +and and then minus the minus the depth +and that way you can make sure that + + align:start position:0% +and that way you can make sure that + + + align:start position:0% +and that way you can make sure that +you're going for a mate in 13 instead of + + align:start position:0% +you're going for a mate in 13 instead of + + + align:start position:0% +you're going for a mate in 13 instead of +a mate and 14 for example you know + + align:start position:0% +a mate and 14 for example you know + + + align:start position:0% +a mate and 14 for example you know +preferring that you take the shorter + + align:start position:0% +preferring that you take the shorter + + + align:start position:0% +preferring that you take the shorter +path make sense + + align:start position:0% +path make sense + + + align:start position:0% +path make sense +so that's one of the things to look out + + align:start position:0% +so that's one of the things to look out + + + align:start position:0% +so that's one of the things to look out +in there and there's also a lot of stuff + + align:start position:0% +in there and there's also a lot of stuff + + + align:start position:0% +in there and there's also a lot of stuff +in there the transposition table has we + + align:start position:0% +in there the transposition table has we + + + align:start position:0% +in there the transposition table has we +talked about caching it's actually a K + + align:start position:0% +talked about caching it's actually a K + + + align:start position:0% +talked about caching it's actually a K +associative cache K way associative + + align:start position:0% +associative cache K way associative + + + align:start position:0% +associative cache K way associative +cache and so you can a very K to see + + align:start position:0% +cache and so you can a very K to see + + + align:start position:0% +cache and so you can a very K to see +what's the best choice of you know how + + align:start position:0% +what's the best choice of you know how + + + align:start position:0% +what's the best choice of you know how +many how many entries you should have + + align:start position:0% +many how many entries you should have + + + align:start position:0% +many how many entries you should have +the more entries you have the longer it + + align:start position:0% +the more entries you have the longer it + + + align:start position:0% +the more entries you have the longer it +will take you to search them + + align:start position:0% +will take you to search them + + + align:start position:0% +will take you to search them +on the other hand the more likely it is + + align:start position:0% +on the other hand the more likely it is + + + align:start position:0% +on the other hand the more likely it is +that good moves stay in the cache okay + + align:start position:0% +that good moves stay in the cache okay + + + align:start position:0% +that good moves stay in the cache okay +so you can decide what's what's the + + align:start position:0% +so you can decide what's what's the + + + align:start position:0% +so you can decide what's what's the +right trade-off there okay so there's a + + align:start position:0% +right trade-off there okay so there's a + + + align:start position:0% +right trade-off there okay so there's a +good tuning optimization there okay + + align:start position:0% +good tuning optimization there okay + + + align:start position:0% +good tuning optimization there okay +questions any questions about + + align:start position:0% +questions any questions about + + + align:start position:0% +questions any questions about +transposition table transmission today + + align:start position:0% +transposition table transmission today + + + align:start position:0% +transposition table transmission today +is a major optimization so Zobrist + + align:start position:0% +is a major optimization so Zobrist + + + align:start position:0% +is a major optimization so Zobrist +hashing so most of these we taught Helen + + align:start position:0% +hashing so most of these we taught Helen + + + align:start position:0% +hashing so most of these we taught Helen +talked about at some level but I wanted + + align:start position:0% +talked about at some level but I wanted + + + align:start position:0% +talked about at some level but I wanted +to sort of give a chance to have people + + align:start position:0% +to sort of give a chance to have people + + + align:start position:0% +to sort of give a chance to have people +ask questions nobody's asking questions + + align:start position:0% +ask questions nobody's asking questions + + + align:start position:0% +ask questions nobody's asking questions +came here for Q&A all you're getting is + + align:start position:0% +came here for Q&A all you're getting is + + + align:start position:0% +came here for Q&A all you're getting is +a okay so let me explain Zobrist hashing + + align:start position:0% +a okay so let me explain Zobrist hashing + + + align:start position:0% +a okay so let me explain Zobrist hashing +again a little bit okay so so Zobrist + + align:start position:0% +again a little bit okay so so Zobrist + + + align:start position:0% +again a little bit okay so so Zobrist +hashing very clever idea so we have our + + align:start position:0% +hashing very clever idea so we have our + + + align:start position:0% +hashing very clever idea so we have our +board right with with a bunch of pieces + + align:start position:0% +board right with with a bunch of pieces + + + align:start position:0% +board right with with a bunch of pieces +on it that's probably the wrong number + + align:start position:0% +on it that's probably the wrong number + + + align:start position:0% +on it that's probably the wrong number +of squares right that's seven by six + + align:start position:0% +of squares right that's seven by six + + + align:start position:0% +of squares right that's seven by six +okay who cares okay so so the idea is + + align:start position:0% +okay who cares okay so so the idea is + + + align:start position:0% +okay who cares okay so so the idea is +that what I'm going to do is have a + + align:start position:0% +that what I'm going to do is have a + + + align:start position:0% +that what I'm going to do is have a +table of random numbers that I'm going + + align:start position:0% +table of random numbers that I'm going + + + align:start position:0% +table of random numbers that I'm going +to compute in advance and this is gonna + + align:start position:0% +to compute in advance and this is gonna + + + align:start position:0% +to compute in advance and this is gonna +be indexed by you know my row my column + + align:start position:0% +be indexed by you know my row my column + + + align:start position:0% +be indexed by you know my row my column +my piece type and my orientation okay + + align:start position:0% +my piece type and my orientation okay + + + align:start position:0% +my piece type and my orientation okay +and every different combination of row + + align:start position:0% +and every different combination of row + + + align:start position:0% +and every different combination of row +column type and orientation corresponds + + align:start position:0% +column type and orientation corresponds + + + align:start position:0% +column type and orientation corresponds +to a different random number in the + + align:start position:0% +to a different random number in the + + + align:start position:0% +to a different random number in the +table okay okay if some sort of random + + align:start position:0% +table okay okay if some sort of random + + + align:start position:0% +table okay okay if some sort of random +number there okay so you know so and + + align:start position:0% +number there okay so you know so and + + + align:start position:0% +number there okay so you know so and +what my hash function is is it's the XOR + + align:start position:0% +what my hash function is is it's the XOR + + + align:start position:0% +what my hash function is is it's the XOR +of all of the values of all the pieces + + align:start position:0% +of all of the values of all the pieces + + + align:start position:0% +of all of the values of all the pieces +that are on this table with their + + align:start position:0% +that are on this table with their + + + align:start position:0% +that are on this table with their +orientations okay so if I have a king + + align:start position:0% +orientations okay so if I have a king + + + align:start position:0% +orientations okay so if I have a king +here you know that's a White King + + align:start position:0% +here you know that's a White King + + + align:start position:0% +here you know that's a White King +I guess I need to know who's who's not + + align:start position:0% +I guess I need to know who's who's not + + + align:start position:0% +I guess I need to know who's who's not +just what the type is I also need to + + align:start position:0% +just what the type is I also need to + + + align:start position:0% +just what the type is I also need to +know whether it's white or black right + + align:start position:0% +know whether it's white or black right + + + align:start position:0% +know whether it's white or black right +so the the side okay I think actually + + align:start position:0% +so the the side okay I think actually + + + align:start position:0% +so the the side okay I think actually +that gets encoded somehow but in any + + align:start position:0% +that gets encoded somehow but in any + + + align:start position:0% +that gets encoded somehow but in any +case yeah I think maybe in the type we + + align:start position:0% +case yeah I think maybe in the type we + + + align:start position:0% +case yeah I think maybe in the type we +actually keep whether it's a whiter pawn + + align:start position:0% +actually keep whether it's a whiter pawn + + + align:start position:0% +actually keep whether it's a whiter pawn +black pawn yeah it's in the type I think + + align:start position:0% +black pawn yeah it's in the type I think + + + align:start position:0% +black pawn yeah it's in the type I think +is the way we actually implement it that + + align:start position:0% +is the way we actually implement it that + + + align:start position:0% +is the way we actually implement it that +okay so there's white king black king + + align:start position:0% +okay so there's white king black king + + + align:start position:0% +okay so there's white king black king +white pawn black pawn or space so if I + + align:start position:0% +white pawn black pawn or space so if I + + + align:start position:0% +white pawn black pawn or space so if I +have a king there that corresponds to a + + align:start position:0% +have a king there that corresponds to a + + + align:start position:0% +have a king there that corresponds to a +certain value if I end up with a pawn + + align:start position:0% +certain value if I end up with a pawn + + + align:start position:0% +certain value if I end up with a pawn +here I'll say a white pawn then that + + align:start position:0% +here I'll say a white pawn then that + + + align:start position:0% +here I'll say a white pawn then that +will be another one and I XOR those + + align:start position:0% +will be another one and I XOR those + + + align:start position:0% +will be another one and I XOR those +together and I take the black King okay + + align:start position:0% +together and I take the black King okay + + + align:start position:0% +together and I take the black King okay +and I XOR his position is and the you + + align:start position:0% +and I XOR his position is and the you + + + align:start position:0% +and I XOR his position is and the you +know black pawn XOR that in and so I XOR + + align:start position:0% +know black pawn XOR that in and so I XOR + + + align:start position:0% +know black pawn XOR that in and so I XOR +all these four values + + align:start position:0% +all these four values + + + align:start position:0% +all these four values +that's the hash function that I use to + + align:start position:0% +that's the hash function that I use to + + + align:start position:0% +that's the hash function that I use to +do things like look up things in the + + align:start position:0% +do things like look up things in the + + + align:start position:0% +do things like look up things in the +transposition table now if I had to + + align:start position:0% +transposition table now if I had to + + + align:start position:0% +transposition table now if I had to +compute this every time I change the + + align:start position:0% +compute this every time I change the + + + align:start position:0% +compute this every time I change the +position you know that's if I have a lot + + align:start position:0% +position you know that's if I have a lot + + + align:start position:0% +position you know that's if I have a lot +of pieces how many pieces I've got I've + + align:start position:0% +of pieces how many pieces I've got I've + + + align:start position:0% +of pieces how many pieces I've got I've +got seven eight sixteen pieces right + + align:start position:0% +got seven eight sixteen pieces right + + + align:start position:0% +got seven eight sixteen pieces right +there's each side has seven pawns in a + + align:start position:0% +there's each side has seven pawns in a + + + align:start position:0% +there's each side has seven pawns in a +king so sixteen pieces I have to do 16 X + + align:start position:0% +king so sixteen pieces I have to do 16 X + + + align:start position:0% +king so sixteen pieces I have to do 16 X +Wars in order to compute my hash + + align:start position:0% +Wars in order to compute my hash + + + align:start position:0% +Wars in order to compute my hash +function so Zobrist rationing is really + + align:start position:0% +function so Zobrist rationing is really + + + align:start position:0% +function so Zobrist rationing is really +a lot clever it takes advantage of that + + align:start position:0% +a lot clever it takes advantage of that + + + align:start position:0% +a lot clever it takes advantage of that +XOR trick that I taught you in the first + + align:start position:0% +XOR trick that I taught you in the first + + + align:start position:0% +XOR trick that I taught you in the first +now it wasn't the first it was in the + + align:start position:0% +now it wasn't the first it was in the + + + align:start position:0% +now it wasn't the first it was in the +the was the second lecture yeah you know + + align:start position:0% +the was the second lecture yeah you know + + + align:start position:0% +the was the second lecture yeah you know +the bit tricks lecture okay and that is + + align:start position:0% +the bit tricks lecture okay and that is + + + align:start position:0% +the bit tricks lecture okay and that is +that XOR is its own inverse so if I want + + align:start position:0% +that XOR is its own inverse so if I want + + + align:start position:0% +that XOR is its own inverse so if I want +to remove a piece let's say I'm going to + + align:start position:0% +to remove a piece let's say I'm going to + + + align:start position:0% +to remove a piece let's say I'm going to +move this pawn okay from here to here so + + align:start position:0% +move this pawn okay from here to here so + + + align:start position:0% +move this pawn okay from here to here so +I remove this piece what do I do to my + + align:start position:0% +I remove this piece what do I do to my + + + align:start position:0% +I remove this piece what do I do to my +hash function to remove a piece I look + + align:start position:0% +hash function to remove a piece I look + + + align:start position:0% +hash function to remove a piece I look +up the value for that pawn in the hash + + align:start position:0% +up the value for that pawn in the hash + + + align:start position:0% +up the value for that pawn in the hash +table and I XOR that into my hash for + + align:start position:0% +table and I XOR that into my hash for + + + align:start position:0% +table and I XOR that into my hash for +the table and I now have + + align:start position:0% +the table and I now have + + + align:start position:0% +the table and I now have +hache for those three pieces left that + + align:start position:0% +hache for those three pieces left that + + + align:start position:0% +hache for those three pieces left that +make sense so I have my hash function + + align:start position:0% +make sense so I have my hash function + + + align:start position:0% +make sense so I have my hash function +which is a hash of the four things I'm + + align:start position:0% +which is a hash of the four things I'm + + + align:start position:0% +which is a hash of the four things I'm +not sure you guys can see very well over + + align:start position:0% +not sure you guys can see very well over + + + align:start position:0% +not sure you guys can see very well over +there but and I basically simply XOR it + + align:start position:0% +there but and I basically simply XOR it + + + align:start position:0% +there but and I basically simply XOR it +with the hash of you know the pawn that + + align:start position:0% +with the hash of you know the pawn that + + + align:start position:0% +with the hash of you know the pawn that +I removed you know from the you know of + + align:start position:0% +I removed you know from the you know of + + + align:start position:0% +I removed you know from the you know of +the pawn that I removed in this case and + + align:start position:0% +the pawn that I removed in this case and + + + align:start position:0% +the pawn that I removed in this case and +now I moved it to here so what do I do I + + align:start position:0% +now I moved it to here so what do I do I + + + align:start position:0% +now I moved it to here so what do I do I +look up that one and I XOR it that value + + align:start position:0% +look up that one and I XOR it that value + + + align:start position:0% +look up that one and I XOR it that value +in here for the new position near the + + align:start position:0% +in here for the new position near the + + + align:start position:0% +in here for the new position near the +new pawn position and that gives me now + + align:start position:0% +new pawn position and that gives me now + + + align:start position:0% +new pawn position and that gives me now +the the the hash for the new table with + + align:start position:0% +the the the hash for the new table with + + + align:start position:0% +the the the hash for the new table with +a pawn in that position so any move that + + align:start position:0% +a pawn in that position so any move that + + + align:start position:0% +a pawn in that position so any move that +I make I can basically update my hash + + align:start position:0% +I make I can basically update my hash + + + align:start position:0% +I make I can basically update my hash +function with only two X source and XOR + + align:start position:0% +function with only two X source and XOR + + + align:start position:0% +function with only two X source and XOR +czar very fast there one instruction you + + align:start position:0% +czar very fast there one instruction you + + + align:start position:0% +czar very fast there one instruction you +know there one and they can do lots of X + + align:start position:0% +know there one and they can do lots of X + + + align:start position:0% +know there one and they can do lots of X +ORS and stuff so this is actually very + + align:start position:0% +ORS and stuff so this is actually very + + + align:start position:0% +ORS and stuff so this is actually very +very cheap thing to do + + align:start position:0% +very cheap thing to do + + + align:start position:0% +very cheap thing to do +okay very cheap thing to do so that's + + align:start position:0% +okay very cheap thing to do so that's + + + align:start position:0% +okay very cheap thing to do so that's +Zobrist hashing that you can keep these + + align:start position:0% +Zobrist hashing that you can keep these + + + align:start position:0% +Zobrist hashing that you can keep these +these things up to date and that's + + align:start position:0% +these things up to date and that's + + + align:start position:0% +these things up to date and that's +something we implemented for you that's + + align:start position:0% +something we implemented for you that's + + + align:start position:0% +something we implemented for you that's +an optimization that was a freebie we + + align:start position:0% +an optimization that was a freebie we + + + align:start position:0% +an optimization that was a freebie we +could have given you the hash function + + align:start position:0% +could have given you the hash function + + + align:start position:0% +could have given you the hash function +you know like this and had you implement + + align:start position:0% +you know like this and had you implement + + + align:start position:0% +you know like this and had you implement +that but this is one of the ones we gave + + align:start position:0% +that but this is one of the ones we gave + + + align:start position:0% +that but this is one of the ones we gave +you as a freebie for optimization you're + + align:start position:0% +you as a freebie for optimization you're + + + align:start position:0% +you as a freebie for optimization you're +not all saying thank you very much + + align:start position:0% +not all saying thank you very much + + + align:start position:0% +not all saying thank you very much +professor leiserson + + align:start position:0% + + + + align:start position:0% + +okay now in some sense I took away an + + align:start position:0% +okay now in some sense I took away an + + + align:start position:0% +okay now in some sense I took away an +opportunity for optimisation didn't I + + align:start position:0% +opportunity for optimisation didn't I + + + align:start position:0% +opportunity for optimisation didn't I +there okay and so in the transposition + + align:start position:0% +there okay and so in the transposition + + + align:start position:0% +there okay and so in the transposition +table there are records for the Zobrist + + align:start position:0% +table there are records for the Zobrist + + + align:start position:0% +table there are records for the Zobrist +key the score the move the quality also + + align:start position:0% +key the score the move the quality also + + + align:start position:0% +key the score the move the quality also +a bound type whether it's upper lower or + + align:start position:0% +a bound type whether it's upper lower or + + + align:start position:0% +a bound type whether it's upper lower or +exact because when I return something + + align:start position:0% +exact because when I return something + + + align:start position:0% +exact because when I return something +from alpha-beta I only know a bound on + + align:start position:0% +from alpha-beta I only know a bound on + + + align:start position:0% +from alpha-beta I only know a bound on +it if it's if it's greater than alpha or + + align:start position:0% +it if it's if it's greater than alpha or + + + align:start position:0% +it if it's if it's greater than alpha or +less than beta and in some sense the age + + align:start position:0% +less than beta and in some sense the age + + + align:start position:0% +less than beta and in some sense the age +of how how old is this move because as + + align:start position:0% +of how how old is this move because as + + + align:start position:0% +of how how old is this move because as +things get older I also want to age them + + align:start position:0% +things get older I also want to age them + + + align:start position:0% +things get older I also want to age them +out of the table + + align:start position:0% +out of the table + + + align:start position:0% +out of the table +there's several aging things therein + + align:start position:0% +there's several aging things therein + + + align:start position:0% +there's several aging things therein +you'll see the best move table also has + + align:start position:0% +you'll see the best move table also has + + + align:start position:0% +you'll see the best move table also has +an aging process whereas every time it + + align:start position:0% +an aging process whereas every time it + + + align:start position:0% +an aging process whereas every time it +updates the values gives a new value it + + align:start position:0% +updates the values gives a new value it + + + align:start position:0% +updates the values gives a new value it +ages all the other values so that they + + align:start position:0% +ages all the other values so that they + + + align:start position:0% +ages all the other values so that they +gradually disappear and aren't relevant + + align:start position:0% +gradually disappear and aren't relevant + + + align:start position:0% +gradually disappear and aren't relevant +one of the ones that people have get + + align:start position:0% +one of the ones that people have get + + + align:start position:0% +one of the ones that people have get +confused about is the late move + + align:start position:0% +confused about is the late move + + + align:start position:0% +confused about is the late move +reductions + + align:start position:0% +reductions + + + align:start position:0% +reductions +okay so called LMR okay this is the + + align:start position:0% +okay so called LMR okay this is the + + + align:start position:0% +okay so called LMR okay this is the +situation where I have I'm going to do + + align:start position:0% +situation where I have I'm going to do + + + align:start position:0% +situation where I have I'm going to do +let's say my parallel search to you know + + align:start position:0% +let's say my parallel search to you know + + + align:start position:0% +let's say my parallel search to you know +of all my moves and the question is you + + align:start position:0% +of all my moves and the question is you + + + align:start position:0% +of all my moves and the question is you +know it's again you're trying to prune + + align:start position:0% +know it's again you're trying to prune + + + align:start position:0% +know it's again you're trying to prune +everything you can okay and so this is + + align:start position:0% +everything you can okay and so this is + + + align:start position:0% +everything you can okay and so this is +the idea is which are the moves that are + + align:start position:0% +the idea is which are the moves that are + + + align:start position:0% +the idea is which are the moves that are +more important to search deeper the ones + + align:start position:0% +more important to search deeper the ones + + + align:start position:0% +more important to search deeper the ones +near the beginning of your move list if + + align:start position:0% +near the beginning of your move list if + + + align:start position:0% +near the beginning of your move list if +it's sorted in best first order or the + + align:start position:0% +it's sorted in best first order or the + + + align:start position:0% +it's sorted in best first order or the +ones towards the end of your move list + + align:start position:0% + + + + align:start position:0% + +so where where is it most important to + + align:start position:0% +so where where is it most important to + + + align:start position:0% +so where where is it most important to +search deeply for things that you think + + align:start position:0% +search deeply for things that you think + + + align:start position:0% +search deeply for things that you think +are possibly the best move or the ones + + align:start position:0% +are possibly the best move or the ones + + + align:start position:0% +are possibly the best move or the ones +that you think are the worst moves yeah + + align:start position:0% +that you think are the worst moves yeah + + + align:start position:0% +that you think are the worst moves yeah +yeah it makes sense to search the best + + align:start position:0% +yeah it makes sense to search the best + + + align:start position:0% +yeah it makes sense to search the best +moves right so the idea is well if + + align:start position:0% +moves right so the idea is well if + + + align:start position:0% +moves right so the idea is well if +something is way down on the move + + align:start position:0% +something is way down on the move + + + align:start position:0% +something is way down on the move +ordering list why search it as deeply + + align:start position:0% +ordering list why search it as deeply + + + align:start position:0% +ordering list why search it as deeply +it's probably not as good a move and so + + align:start position:0% +it's probably not as good a move and so + + + align:start position:0% +it's probably not as good a move and so +let me search it more shallow I probably + + align:start position:0% +let me search it more shallow I probably + + + align:start position:0% +let me search it more shallow I probably +don't lose much of an opportunity to + + align:start position:0% +don't lose much of an opportunity to + + + align:start position:0% +don't lose much of an opportunity to +discover that that's actually a you know + + align:start position:0% +discover that that's actually a you know + + + align:start position:0% +discover that that's actually a you know +is indeed a bad move okay there's a + + align:start position:0% +is indeed a bad move okay there's a + + + align:start position:0% +is indeed a bad move okay there's a +reason that got ordered down there and + + align:start position:0% +reason that got ordered down there and + + + align:start position:0% +reason that got ordered down there and +so that's late move reduction so with a + + align:start position:0% +so that's late move reduction so with a + + + align:start position:0% +so that's late move reduction so with a +good move ordering a beta it kind of + + align:start position:0% +good move ordering a beta it kind of + + + align:start position:0% +good move ordering a beta it kind of +will either occur right away or not also + + align:start position:0% +will either occur right away or not also + + + align:start position:0% +will either occur right away or not also +you search the first few moves normally + + align:start position:0% +you search the first few moves normally + + + align:start position:0% +you search the first few moves normally +and then you start reducing the depth + + align:start position:0% +and then you start reducing the depth + + + align:start position:0% +and then you start reducing the depth +for four moves I believe in our code we + + align:start position:0% +for four moves I believe in our code we + + + align:start position:0% +for four moves I believe in our code we +have two numbers where we reduce by + + align:start position:0% +have two numbers where we reduce by + + + align:start position:0% +have two numbers where we reduce by +depth one after a certain number of + + align:start position:0% +depth one after a certain number of + + + align:start position:0% +depth one after a certain number of +moves and reduced by depth two after a + + align:start position:0% +moves and reduced by depth two after a + + + align:start position:0% +moves and reduced by depth two after a +certain number of other moves those are + + align:start position:0% +certain number of other moves those are + + + align:start position:0% +certain number of other moves those are +things that you can tune I wouldn't tune + + align:start position:0% +things that you can tune I wouldn't tune + + + align:start position:0% +things that you can tune I wouldn't tune +them very much I don't think just + + align:start position:0% +them very much I don't think just + + + align:start position:0% +them very much I don't think just +because and once again I could probably + + align:start position:0% +because and once again I could probably + + + align:start position:0% +because and once again I could probably +be wrong here and some of those discover + + align:start position:0% +be wrong here and some of those discover + + + align:start position:0% +be wrong here and some of those discover +oh you know if you tune it like this + + align:start position:0% +oh you know if you tune it like this + + + align:start position:0% +oh you know if you tune it like this +it's way better okay but those are those + + align:start position:0% +it's way better okay but those are those + + + align:start position:0% +it's way better okay but those are those +are that's the idea of the late move + + align:start position:0% +are that's the idea of the late move + + + align:start position:0% +are that's the idea of the late move +reductions probably one of the most + + align:start position:0% +reductions probably one of the most + + + align:start position:0% +reductions probably one of the most +important things to think about is the + + align:start position:0% +important things to think about is the + + + align:start position:0% +important things to think about is the +move is the representation of the board + + align:start position:0% +move is the representation of the board + + + align:start position:0% +move is the representation of the board +right now we represent the board as it + + align:start position:0% +right now we represent the board as it + + + align:start position:0% +right now we represent the board as it +is okay that's a terrible representation + + align:start position:0% +is okay that's a terrible representation + + + align:start position:0% +is okay that's a terrible representation +it's very you know time-consuming + + align:start position:0% +it's very you know time-consuming + + + align:start position:0% +it's very you know time-consuming +there's sort of two major ways you can + + align:start position:0% +there's sort of two major ways you can + + + align:start position:0% +there's sort of two major ways you can +do it oh I didn't put the other one here + + align:start position:0% +do it oh I didn't put the other one here + + + align:start position:0% +do it oh I didn't put the other one here +okay well anyway so one of them is bit + + align:start position:0% +okay well anyway so one of them is bit + + + align:start position:0% +okay well anyway so one of them is bit +boards here you use a 64 bit to + + align:start position:0% +boards here you use a 64 bit to + + + align:start position:0% +boards here you use a 64 bit to +represent for example where all the + + align:start position:0% +represent for example where all the + + + align:start position:0% +represent for example where all the +pawns are on the 64 squares of the board + + align:start position:0% +pawns are on the 64 squares of the board + + + align:start position:0% +pawns are on the 64 squares of the board +okay and then you can use pop count and + + align:start position:0% +okay and then you can use pop count and + + + align:start position:0% +okay and then you can use pop count and +other bit tricks to do move generation + + align:start position:0% +other bit tricks to do move generation + + + align:start position:0% +other bit tricks to do move generation +and to implement other chess concepts + + align:start position:0% +and to implement other chess concepts + + + align:start position:0% +and to implement other chess concepts +okay so if you're looking to see what + + align:start position:0% +okay so if you're looking to see what + + + align:start position:0% +okay so if you're looking to see what +are the possible places upon can move + + align:start position:0% +are the possible places upon can move + + + align:start position:0% +are the possible places upon can move +and you want to say can they move right + + align:start position:0% +and you want to say can they move right + + + align:start position:0% +and you want to say can they move right +and let's say it's stored in row major + + align:start position:0% +and let's say it's stored in row major + + + align:start position:0% +and let's say it's stored in row major +order you can just do a right shift by + + align:start position:0% +order you can just do a right shift by + + + align:start position:0% +order you can just do a right shift by +one and that tells you where are all the + + align:start position:0% +one and that tells you where are all the + + + align:start position:0% +one and that tells you where are all the +places that pawns those pawns could move + + align:start position:0% +places that pawns those pawns could move + + + align:start position:0% +places that pawns those pawns could move +and now you can just pick them off one + + align:start position:0% +and now you can just pick them off one + + + align:start position:0% +and now you can just pick them off one +bit at a time to generate your move list + + align:start position:0% +bit at a time to generate your move list + + + align:start position:0% +bit at a time to generate your move list +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and and then you can do it that way if + + align:start position:0% +and and then you can do it that way if + + + align:start position:0% +and and then you can do it that way if +you're gonna move up a thing well then + + align:start position:0% +you're gonna move up a thing well then + + + align:start position:0% +you're gonna move up a thing well then +you're actually doing a shift by or down + + align:start position:0% +you're actually doing a shift by or down + + + align:start position:0% +you're actually doing a shift by or down +you're doing a shift by how much by 8 + + align:start position:0% +you're doing a shift by how much by 8 + + + align:start position:0% +you're doing a shift by how much by 8 +right to move up or down okay if you're + + align:start position:0% +right to move up or down okay if you're + + + align:start position:0% +right to move up or down okay if you're +storing things in row major all right + + align:start position:0% +storing things in row major all right + + + align:start position:0% +storing things in row major all right +that makes sense right + + align:start position:0% +that makes sense right + + + align:start position:0% +that makes sense right +so if it's it's 8 by 8 and you're + + align:start position:0% +so if it's it's 8 by 8 and you're + + + align:start position:0% +so if it's it's 8 by 8 and you're +keeping a bit for each thing then if I + + align:start position:0% +keeping a bit for each thing then if I + + + align:start position:0% +keeping a bit for each thing then if I +want to generate you know where is this + + align:start position:0% +want to generate you know where is this + + + align:start position:0% +want to generate you know where is this +one if I shift this whole thing stored + + align:start position:0% +one if I shift this whole thing stored + + + align:start position:0% +one if I shift this whole thing stored +in row major order by 8 if I shift it + + align:start position:0% +in row major order by 8 if I shift it + + + align:start position:0% +in row major order by 8 if I shift it +right it basically puts it there okay so + + align:start position:0% +right it basically puts it there okay so + + + align:start position:0% +right it basically puts it there okay so +moving it by you know 7 8 9 that gives + + align:start position:0% +moving it by you know 7 8 9 that gives + + + align:start position:0% +moving it by you know 7 8 9 that gives +you and then shifting it by 1 gives you + + align:start position:0% +you and then shifting it by 1 gives you + + + align:start position:0% +you and then shifting it by 1 gives you +the you know or minus 1 gives you this + + align:start position:0% +the you know or minus 1 gives you this + + + align:start position:0% +the you know or minus 1 gives you this +or left by 1 and then similarly you can + + align:start position:0% +or left by 1 and then similarly you can + + + align:start position:0% +or left by 1 and then similarly you can +do by you know shifting by 7 8 or 9 that + + align:start position:0% +do by you know shifting by 7 8 or 9 that + + + align:start position:0% +do by you know shifting by 7 8 or 9 that +way and I can generate all the possible + + align:start position:0% +way and I can generate all the possible + + + align:start position:0% +way and I can generate all the possible +moves so that's one way of doing move + + align:start position:0% +moves so that's one way of doing move + + + align:start position:0% +moves so that's one way of doing move +generation he's using bit for it and + + align:start position:0% +generation he's using bit for it and + + + align:start position:0% +generation he's using bit for it and +there are a lot of things for example + + align:start position:0% +there are a lot of things for example + + + align:start position:0% +there are a lot of things for example +that you can do with bit boards in + + align:start position:0% +that you can do with bit boards in + + + align:start position:0% +that you can do with bit boards in +parallel because you can say did I make + + align:start position:0% +parallel because you can say did I make + + + align:start position:0% +parallel because you can say did I make +a capture here okay or let me use a bit + + align:start position:0% +a capture here okay or let me use a bit + + + align:start position:0% +a capture here okay or let me use a bit +board to represent where the laser goes + + align:start position:0% +board to represent where the laser goes + + + align:start position:0% +board to represent where the laser goes +did I make a move that is that is going + + align:start position:0% +did I make a move that is that is going + + + align:start position:0% +did I make a move that is that is going +to affect the path of laser okay because + + align:start position:0% + + + + align:start position:0% + +because you know one of the major + + align:start position:0% +because you know one of the major + + + align:start position:0% +because you know one of the major +optimizations you can do is in the in + + align:start position:0% +optimizations you can do is in the in + + + align:start position:0% +optimizations you can do is in the in +the evaluations in dealing with a laser + + align:start position:0% +the evaluations in dealing with a laser + + + align:start position:0% +the evaluations in dealing with a laser +okay because you're spending a lot of + + align:start position:0% +okay because you're spending a lot of + + + align:start position:0% +okay because you're spending a lot of +time stroking out Laser positions what's + + align:start position:0% +time stroking out Laser positions what's + + + align:start position:0% +time stroking out Laser positions what's +the point of doing that if you made a + + align:start position:0% +the point of doing that if you made a + + + align:start position:0% +the point of doing that if you made a +move of something and it didn't affect + + align:start position:0% +move of something and it didn't affect + + + align:start position:0% +move of something and it didn't affect +where the laser goes why bother + + align:start position:0% +where the laser goes why bother + + + align:start position:0% +where the laser goes why bother +you know doing it out you can just cash + + align:start position:0% +you know doing it out you can just cash + + + align:start position:0% +you know doing it out you can just cash +what the what the value of the laser is + + align:start position:0% +what the what the value of the laser is + + + align:start position:0% +what the what the value of the laser is +and there are a lot of lot more good + + align:start position:0% +and there are a lot of lot more good + + + align:start position:0% +and there are a lot of lot more good +stuff on the chest programming wiki okay + + align:start position:0% +stuff on the chest programming wiki okay + + + align:start position:0% +stuff on the chest programming wiki okay +so yeah question + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +yeah you got to be careful there right + + align:start position:0% +yeah you got to be careful there right + + + align:start position:0% +yeah you got to be careful there right +because if I do a shift to the right for + + align:start position:0% +because if I do a shift to the right for + + + align:start position:0% +because if I do a shift to the right for +example so what will I do + + align:start position:0% +example so what will I do + + + align:start position:0% +example so what will I do +I'll just do a mask to eliminate all the + + align:start position:0% +I'll just do a mask to eliminate all the + + + align:start position:0% +I'll just do a mask to eliminate all the +things that got wrapped around okay + + align:start position:0% +things that got wrapped around okay + + + align:start position:0% +things that got wrapped around okay +right so two instructions or whatever + + align:start position:0% +right so two instructions or whatever + + + align:start position:0% +right so two instructions or whatever +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +details yes details are good though good + + align:start position:0% +details yes details are good though good + + + align:start position:0% +details yes details are good though good +question + + align:start position:0% +question + + + align:start position:0% +question +good question who's timed their program + + align:start position:0% +good question who's timed their program + + + align:start position:0% +good question who's timed their program +where are the where are the + + align:start position:0% +where are the where are the + + + align:start position:0% +where are the where are the +opportunities that you see for + + align:start position:0% +opportunities that you see for + + + align:start position:0% +opportunities that you see for +performance engineering for a first pass + + align:start position:0% +performance engineering for a first pass + + + align:start position:0% +performance engineering for a first pass +what are those expensive things what do + + align:start position:0% +what are those expensive things what do + + + align:start position:0% +what are those expensive things what do +you have as expensive thing + + align:start position:0% + + + + align:start position:0% + +sorry the marking laser path yep good + + align:start position:0% +sorry the marking laser path yep good + + + align:start position:0% +sorry the marking laser path yep good +what else is is time expensive + + align:start position:0% +what else is is time expensive + + + align:start position:0% +what else is is time expensive +yeah laser coverage boy that is really + + align:start position:0% +yeah laser coverage boy that is really + + + align:start position:0% +yeah laser coverage boy that is really +expensive okay that is really expensive + + align:start position:0% +expensive okay that is really expensive + + + align:start position:0% +expensive okay that is really expensive +so where else is expensive + + align:start position:0% + + + + align:start position:0% + +what else is expensive so I would + + align:start position:0% +what else is expensive so I would + + + align:start position:0% +what else is expensive so I would +definitely go after you know L cover + + align:start position:0% +definitely go after you know L cover + + + align:start position:0% +definitely go after you know L cover +that's a that's a huge one to go after + + align:start position:0% +that's a that's a huge one to go after + + + align:start position:0% +that's a that's a huge one to go after +one of the things by the way if you are + + align:start position:0% +one of the things by the way if you are + + + align:start position:0% +one of the things by the way if you are +making your your changes to the code and + + align:start position:0% +making your your changes to the code and + + + align:start position:0% +making your your changes to the code and +you're gonna change the representation + + align:start position:0% +you're gonna change the representation + + + align:start position:0% +you're gonna change the representation +leave the old representation there take + + align:start position:0% +leave the old representation there take + + + align:start position:0% +leave the old representation there take +it out at the end add the new + + align:start position:0% +it out at the end add the new + + + align:start position:0% +it out at the end add the new +representation and put in assertions + + align:start position:0% +representation and put in assertions + + + align:start position:0% +representation and put in assertions +that say that things are equivalent or + + align:start position:0% +that say that things are equivalent or + + + align:start position:0% +that say that things are equivalent or +whatever but don't get rid of the old + + align:start position:0% +whatever but don't get rid of the old + + + align:start position:0% +whatever but don't get rid of the old +stuff because you'll end up with broken + + align:start position:0% +stuff because you'll end up with broken + + + align:start position:0% +stuff because you'll end up with broken +code and definitely using use things + + align:start position:0% +code and definitely using use things + + + align:start position:0% +code and definitely using use things +like perfectiy to tell you whether or + + align:start position:0% +like perfectiy to tell you whether or + + + align:start position:0% +like perfectiy to tell you whether or +not you you know made any change you + + align:start position:0% +not you you know made any change you + + + align:start position:0% +not you you know made any change you +know made any changes if you touch + + align:start position:0% +know made any changes if you touch + + + align:start position:0% +know made any changes if you touch +anything with move ordering sorry not a + + align:start position:0% +anything with move ordering sorry not a + + + align:start position:0% +anything with move ordering sorry not a +move generation not move ordered move + + align:start position:0% +move generation not move ordered move + + + align:start position:0% +move generation not move ordered move +generation so where else is expensive + + align:start position:0% +generation so where else is expensive + + + align:start position:0% +generation so where else is expensive +yeah + + align:start position:0% + + + + align:start position:0% + +sure you want to get your how much + + align:start position:0% +sure you want to get your how much + + + align:start position:0% +sure you want to get your how much +detail do you want how it actually works + + align:start position:0% +detail do you want how it actually works + + + align:start position:0% +detail do you want how it actually works +okay so what it's supposed to do is + + align:start position:0% + + + + align:start position:0% + +what's supposed to do is figure out how + + align:start position:0% +what's supposed to do is figure out how + + + align:start position:0% +what's supposed to do is figure out how +safe what you're the idea is I want my + + align:start position:0% +safe what you're the idea is I want my + + + align:start position:0% +safe what you're the idea is I want my +laser to get closer to your King and I + + align:start position:0% +laser to get closer to your King and I + + + align:start position:0% +laser to get closer to your King and I +want your laser not to be close to my + + align:start position:0% +want your laser not to be close to my + + + align:start position:0% +want your laser not to be close to my +king + + align:start position:0% +king + + + align:start position:0% +king +right and if I can move into positions + + align:start position:0% +right and if I can move into positions + + + align:start position:0% +right and if I can move into positions +where my laser is closer to your King + + align:start position:0% +where my laser is closer to your King + + + align:start position:0% +where my laser is closer to your King +but your laser doesn't get closer to my + + align:start position:0% +but your laser doesn't get closer to my + + + align:start position:0% +but your laser doesn't get closer to my +King that's a good sort of thing but + + align:start position:0% +King that's a good sort of thing but + + + align:start position:0% +King that's a good sort of thing but +when we say get the laser close you know + + align:start position:0% +when we say get the laser close you know + + + align:start position:0% +when we say get the laser close you know +what happens when I've got say let me do + + align:start position:0% +what happens when I've got say let me do + + + align:start position:0% +what happens when I've got say let me do +it this way a position like this so + + align:start position:0% +it this way a position like this so + + + align:start position:0% +it this way a position like this so +here's the okay suppose I look at this + + align:start position:0% +here's the okay suppose I look at this + + + align:start position:0% +here's the okay suppose I look at this +position how close does the laser get + + align:start position:0% +position how close does the laser get + + + align:start position:0% +position how close does the laser get +Mike let's say I'm black here and I look + + align:start position:0% +Mike let's say I'm black here and I look + + + align:start position:0% +Mike let's say I'm black here and I look +at the laser well the path of the laser + + align:start position:0% +at the laser well the path of the laser + + + align:start position:0% +at the laser well the path of the laser +is it bounces there and goes across + + align:start position:0% +is it bounces there and goes across + + + align:start position:0% +is it bounces there and goes across +right okay so I didn't get very close to + + align:start position:0% +right okay so I didn't get very close to + + + align:start position:0% +right okay so I didn't get very close to +the King there but I'm one move away + + align:start position:0% +the King there but I'm one move away + + + align:start position:0% +the King there but I'm one move away +from getting it pretty close because if + + align:start position:0% +from getting it pretty close because if + + + align:start position:0% +from getting it pretty close because if +I just move this guy out of the way now + + align:start position:0% +I just move this guy out of the way now + + + align:start position:0% +I just move this guy out of the way now +I've got it really quite close okay so + + align:start position:0% +I've got it really quite close okay so + + + align:start position:0% +I've got it really quite close okay so +if I compare that to let's say a + + align:start position:0% +if I compare that to let's say a + + + align:start position:0% +if I compare that to let's say a +situation where instead of the the + + align:start position:0% +situation where instead of the the + + + align:start position:0% +situation where instead of the the +plants are there let's say a pawn is + + align:start position:0% +plants are there let's say a pawn is + + + align:start position:0% +plants are there let's say a pawn is +here okay + + align:start position:0% +here okay + + + align:start position:0% +here okay +now the laser is actually closer to the + + align:start position:0% +now the laser is actually closer to the + + + align:start position:0% +now the laser is actually closer to the +King that it was in the first position + + align:start position:0% +King that it was in the first position + + + align:start position:0% +King that it was in the first position +but it's a much worse position right the + + align:start position:0% +but it's a much worse position right the + + + align:start position:0% +but it's a much worse position right the +first one was much better when I had the + + align:start position:0% +first one was much better when I had the + + + align:start position:0% +first one was much better when I had the +pawns here and here because I was simply + + align:start position:0% +pawns here and here because I was simply + + + align:start position:0% +pawns here and here because I was simply +one move away from getting it really + + align:start position:0% +one move away from getting it really + + + align:start position:0% +one move away from getting it really +close and so if you use just the direct + + align:start position:0% +close and so if you use just the direct + + + align:start position:0% +close and so if you use just the direct +laser thing and we did some tests on + + align:start position:0% +laser thing and we did some tests on + + + align:start position:0% +laser thing and we did some tests on +this this turns out to be not very it + + align:start position:0% +this this turns out to be not very it + + + align:start position:0% +this this turns out to be not very it +doesn't guide the program very well on + + align:start position:0% +doesn't guide the program very well on + + + align:start position:0% +doesn't guide the program very well on +getting into situations where my laser + + align:start position:0% +getting into situations where my laser + + + align:start position:0% +getting into situations where my laser +is getting close to your king + + align:start position:0% +is getting close to your king + + + align:start position:0% +is getting close to your king +that makes sense so then we said well + + align:start position:0% +that makes sense so then we said well + + + align:start position:0% +that makes sense so then we said well +how can we you know how should we + + align:start position:0% +how can we you know how should we + + + align:start position:0% +how can we you know how should we +measure on how close the laser get so + + align:start position:0% +measure on how close the laser get so + + + align:start position:0% +measure on how close the laser get so +what we said is well let's take a look + + align:start position:0% +what we said is well let's take a look + + + align:start position:0% +what we said is well let's take a look +at all the possible moves from here of + + align:start position:0% +at all the possible moves from here of + + + align:start position:0% +at all the possible moves from here of +one move you know and then look to see + + align:start position:0% +one move you know and then look to see + + + align:start position:0% +one move you know and then look to see +how close we get things and the way we + + align:start position:0% +how close we get things and the way we + + + align:start position:0% +how close we get things and the way we +did that is we said let's you know this + + align:start position:0% +did that is we said let's you know this + + + align:start position:0% +did that is we said let's you know this +took actually Helen and I worked on this + + align:start position:0% +took actually Helen and I worked on this + + + align:start position:0% +took actually Helen and I worked on this +really hard okay because this is a new + + align:start position:0% +really hard okay because this is a new + + + align:start position:0% +really hard okay because this is a new +heuristic that we have not used in + + align:start position:0% +heuristic that we have not used in + + + align:start position:0% +heuristic that we have not used in +previous years and it works great it's + + align:start position:0% +previous years and it works great it's + + + align:start position:0% +previous years and it works great it's +just slow as anything okay but it works + + align:start position:0% +just slow as anything okay but it works + + + align:start position:0% +just slow as anything okay but it works +well so you have to evaluate is it worth + + align:start position:0% +well so you have to evaluate is it worth + + + align:start position:0% +well so you have to evaluate is it worth +doing something if it's really slow it + + align:start position:0% +doing something if it's really slow it + + + align:start position:0% +doing something if it's really slow it +may be that you do better to use a + + align:start position:0% +may be that you do better to use a + + + align:start position:0% +may be that you do better to use a +simpler heuristic and get deeper search + + align:start position:0% +simpler heuristic and get deeper search + + + align:start position:0% +simpler heuristic and get deeper search +than it is spending a lot of time + + align:start position:0% +than it is spending a lot of time + + + align:start position:0% +than it is spending a lot of time +evaluating but anyway we gave you one + + align:start position:0% +evaluating but anyway we gave you one + + + align:start position:0% +evaluating but anyway we gave you one +that if you can make it go fast should + + align:start position:0% +that if you can make it go fast should + + + align:start position:0% +that if you can make it go fast should +be really good so what the idea is that + + align:start position:0% +be really good so what the idea is that + + + align:start position:0% +be really good so what the idea is that +what we do is we look at all the + + align:start position:0% +what we do is we look at all the + + + align:start position:0% +what we do is we look at all the +different paths from moving any piece + + align:start position:0% +different paths from moving any piece + + + align:start position:0% +different paths from moving any piece +want you know one piece and look at the + + align:start position:0% +want you know one piece and look at the + + + align:start position:0% +want you know one piece and look at the +paths of the laser and what we do is we + + align:start position:0% +paths of the laser and what we do is we + + + align:start position:0% +paths of the laser and what we do is we +go we count one for every position that + + align:start position:0% +go we count one for every position that + + + align:start position:0% +go we count one for every position that +we go away 2 3 4 5 6 7 etc we actually + + align:start position:0% +we go away 2 3 4 5 6 7 etc we actually + + + align:start position:0% +we go away 2 3 4 5 6 7 etc we actually +add an extra value if we bounce off in + + align:start position:0% +add an extra value if we bounce off in + + + align:start position:0% +add an extra value if we bounce off in +an opponent's how much do we add Helen + + align:start position:0% +an opponent's how much do we add Helen + + + align:start position:0% +an opponent's how much do we add Helen +do we add one or two if we bounce off an + + align:start position:0% +do we add one or two if we bounce off an + + + align:start position:0% +do we add one or two if we bounce off an +opponent I think - yeah so if this is an + + align:start position:0% +opponent I think - yeah so if this is an + + + align:start position:0% +opponent I think - yeah so if this is an +opponent's pawn we would basically go + + align:start position:0% +opponent's pawn we would basically go + + + align:start position:0% +opponent's pawn we would basically go +from 3 to 5 6 7 you know 8 9 and we + + align:start position:0% +from 3 to 5 6 7 you know 8 9 and we + + + align:start position:0% +from 3 to 5 6 7 you know 8 9 and we +basically do that for all the moves and + + align:start position:0% +basically do that for all the moves and + + + align:start position:0% +basically do that for all the moves and +the way we combine them is we take the + + align:start position:0% +the way we combine them is we take the + + + align:start position:0% +the way we combine them is we take the +minimum number that I can get there ok + + align:start position:0% +minimum number that I can get there ok + + + align:start position:0% +minimum number that I can get there ok +what's the what's the cheapest way I can + + align:start position:0% +what's the what's the cheapest way I can + + + align:start position:0% +what's the what's the cheapest way I can +get to every every square that the laser + + align:start position:0% +get to every every square that the laser + + + align:start position:0% +get to every every square that the laser +goes so we take all the different moves + + align:start position:0% +goes so we take all the different moves + + + align:start position:0% +goes so we take all the different moves +we stroke them out and we take the + + align:start position:0% +we stroke them out and we take the + + + align:start position:0% +we stroke them out and we take the +minimum so if I have another path let's + + align:start position:0% +minimum so if I have another path let's + + + align:start position:0% +minimum so if I have another path let's +say by turning the king it will go this + + align:start position:0% +say by turning the king it will go this + + + align:start position:0% +say by turning the king it will go this +way and there's a you know there's + + align:start position:0% +way and there's a you know there's + + + align:start position:0% +way and there's a you know there's +another one here that's my pawn ok then + + align:start position:0% +another one here that's my pawn ok then + + + align:start position:0% +another one here that's my pawn ok then +I may get there in 1 2 3 4 5 6 7 and so + + align:start position:0% +I may get there in 1 2 3 4 5 6 7 and so + + + align:start position:0% +I may get there in 1 2 3 4 5 6 7 and so +then this would become a value of 7 here + + align:start position:0% +then this would become a value of 7 here + + + align:start position:0% +then this would become a value of 7 here +okay so that's the first thing is we + + align:start position:0% +okay so that's the first thing is we + + + align:start position:0% +okay so that's the first thing is we +basically get a map of you know how + + align:start position:0% +basically get a map of you know how + + + align:start position:0% +basically get a map of you know how +close are things and the second thing we + + align:start position:0% +close are things and the second thing we + + + align:start position:0% +close are things and the second thing we +do is say well how valuable is it to + + align:start position:0% +do is say well how valuable is it to + + + align:start position:0% +do is say well how valuable is it to +have these these you know to be near the + + align:start position:0% +have these these you know to be near the + + + align:start position:0% +have these these you know to be near the +particular King and then what we ended + + align:start position:0% +particular King and then what we ended + + + align:start position:0% +particular King and then what we ended +up with is something where if I look at + + align:start position:0% +up with is something where if I look at + + + align:start position:0% +up with is something where if I look at +the if I look at the distance that I am + + align:start position:0% +the if I look at the distance that I am + + + align:start position:0% +the if I look at the distance that I am +away let's say this one for example is + + align:start position:0% +away let's say this one for example is + + + align:start position:0% +away let's say this one for example is +one row in one column away this is zero + + align:start position:0% +one row in one column away this is zero + + + align:start position:0% +one row in one column away this is zero +row zero columns we use I think it's one + + align:start position:0% +row zero columns we use I think it's one + + + align:start position:0% +row zero columns we use I think it's one +over the row plus one times one over the + + align:start position:0% +over the row plus one times one over the + + + align:start position:0% +over the row plus one times one over the +column plus one okay as a multiplier to + + align:start position:0% +column plus one okay as a multiplier to + + + align:start position:0% +column plus one okay as a multiplier to +wait how good it is that we've been + + align:start position:0% +wait how good it is that we've been + + + align:start position:0% +wait how good it is that we've been +close to the king and we invert these + + align:start position:0% +close to the king and we invert these + + + align:start position:0% +close to the king and we invert these +values so that they're you know so the + + align:start position:0% +values so that they're you know so the + + + align:start position:0% +values so that they're you know so the +closer you you know so that it's better + + align:start position:0% +closer you you know so that it's better + + + align:start position:0% +closer you you know so that it's better +to have a smaller number there and we + + align:start position:0% +to have a smaller number there and we + + + align:start position:0% +to have a smaller number there and we +add them up okay and that basically + + align:start position:0% +add them up okay and that basically + + + align:start position:0% +add them up okay and that basically +gives we I don't quite add them up we + + align:start position:0% +gives we I don't quite add them up we + + + align:start position:0% +gives we I don't quite add them up we +actually no I'm sorry what we do is we + + align:start position:0% +actually no I'm sorry what we do is we + + + align:start position:0% +actually no I'm sorry what we do is we +look at these things as a fraction of my + + align:start position:0% +look at these things as a fraction of my + + + align:start position:0% +look at these things as a fraction of my +shortest path distance sorry that's what + + align:start position:0% +shortest path distance sorry that's what + + + align:start position:0% +shortest path distance sorry that's what +we did yes I'm sorry that is a previous + + align:start position:0% +we did yes I'm sorry that is a previous + + + align:start position:0% +we did yes I'm sorry that is a previous +sourcing so so here for example let's + + align:start position:0% +sourcing so so here for example let's + + + align:start position:0% +sourcing so so here for example let's +say this is the nine the shortest way of + + align:start position:0% +say this is the nine the shortest way of + + + align:start position:0% +say this is the nine the shortest way of +getting there is one two three four five + + align:start position:0% +getting there is one two three four five + + + align:start position:0% +getting there is one two three four five +six seven eight + + align:start position:0% +six seven eight + + + align:start position:0% +six seven eight +so this would actually when we do the + + align:start position:0% +so this would actually when we do the + + + align:start position:0% +so this would actually when we do the +conversion this would we give a value of + + align:start position:0% +conversion this would we give a value of + + + align:start position:0% +conversion this would we give a value of +eight ninths for being in that square + + align:start position:0% +eight ninths for being in that square + + + align:start position:0% +eight ninths for being in that square +okay so we didn't get it where's this + + align:start position:0% +okay so we didn't get it where's this + + + align:start position:0% +okay so we didn't get it where's this +one the shortest path distance is 7 + + align:start position:0% +one the shortest path distance is 7 + + + align:start position:0% +one the shortest path distance is 7 +because of this path and you can get + + align:start position:0% +because of this path and you can get + + + align:start position:0% +because of this path and you can get +there and seven this would have a value + + align:start position:0% +there and seven this would have a value + + + align:start position:0% +there and seven this would have a value +of one so this is better you know and so + + align:start position:0% +of one so this is better you know and so + + + align:start position:0% +of one so this is better you know and so +we do that for all the squares we get a + + align:start position:0% +we do that for all the squares we get a + + + align:start position:0% +we do that for all the squares we get a +fraction of how much do we do and then + + align:start position:0% +fraction of how much do we do and then + + + align:start position:0% +fraction of how much do we do and then +we wait it by something like this which + + align:start position:0% +we wait it by something like this which + + + align:start position:0% +we wait it by something like this which +falls away quickly but it's important in + + align:start position:0% +falls away quickly but it's important in + + + align:start position:0% +falls away quickly but it's important in +heuristics like this to have a smooth + + align:start position:0% +heuristics like this to have a smooth + + + align:start position:0% +heuristics like this to have a smooth +path so that you can get things closer + + align:start position:0% +path so that you can get things closer + + + align:start position:0% +path so that you can get things closer +if I made all these things be 0 it + + align:start position:0% +if I made all these things be 0 it + + + align:start position:0% +if I made all these things be 0 it +wouldn't know that it could you know + + align:start position:0% +wouldn't know that it could you know + + + align:start position:0% +wouldn't know that it could you know +move up and get a little bit better you + + align:start position:0% +move up and get a little bit better you + + + align:start position:0% +move up and get a little bit better you +know in the second or third order + + align:start position:0% +know in the second or third order + + + align:start position:0% +know in the second or third order +you know digit to get closer and so then + + align:start position:0% +you know digit to get closer and so then + + + align:start position:0% +you know digit to get closer and so then +we add it all up and that ends up being + + align:start position:0% +we add it all up and that ends up being + + + align:start position:0% +we add it all up and that ends up being +a number we discovered that sort of in + + align:start position:0% +a number we discovered that sort of in + + + align:start position:0% +a number we discovered that sort of in +the range of + + align:start position:0% +the range of + + + align:start position:0% +the range of +you know you know like what did we + + align:start position:0% +you know you know like what did we + + + align:start position:0% +you know you know like what did we +figure the range was there there's like + + align:start position:0% +figure the range was there there's like + + + align:start position:0% +figure the range was there there's like +you know up to like four or so right + + align:start position:0% +you know up to like four or so right + + + align:start position:0% +you know up to like four or so right +something something like four on average + + align:start position:0% +something something like four on average + + + align:start position:0% +something something like four on average +you know would be the maximum value + + align:start position:0% +you know would be the maximum value + + + align:start position:0% +you know would be the maximum value +would be and then we said okay then we + + align:start position:0% +would be and then we said okay then we + + + align:start position:0% +would be and then we said okay then we +have this magic constant multiplier that + + align:start position:0% +have this magic constant multiplier that + + + align:start position:0% +have this magic constant multiplier that +you can play with that says okay let's + + align:start position:0% +you can play with that says okay let's + + + align:start position:0% +you can play with that says okay let's +represent that as a fraction of a pawn + + align:start position:0% +represent that as a fraction of a pawn + + + align:start position:0% +represent that as a fraction of a pawn +how much is that worth and we multiply + + align:start position:0% +how much is that worth and we multiply + + + align:start position:0% +how much is that worth and we multiply +by that value okay so that's what we're + + align:start position:0% +by that value okay so that's what we're + + + align:start position:0% +by that value okay so that's what we're +doing okay so that it makes it so that + + align:start position:0% +doing okay so that it makes it so that + + + align:start position:0% +doing okay so that it makes it so that +we do tend to move the laser our laser + + align:start position:0% +we do tend to move the laser our laser + + + align:start position:0% +we do tend to move the laser our laser +closer we subtract how close the + + align:start position:0% +closer we subtract how close the + + + align:start position:0% +closer we subtract how close the +opponent can get from us and then we say + + align:start position:0% +opponent can get from us and then we say + + + align:start position:0% +opponent can get from us and then we say +that's the evaluation now if you have a + + align:start position:0% +that's the evaluation now if you have a + + + align:start position:0% +that's the evaluation now if you have a +better way of determining whether a + + align:start position:0% +better way of determining whether a + + + align:start position:0% +better way of determining whether a +laser is getting close than this one + + align:start position:0% +laser is getting close than this one + + + align:start position:0% +laser is getting close than this one +that's cheaper to compute that's good + + align:start position:0% +that's cheaper to compute that's good + + + align:start position:0% +that's cheaper to compute that's good +okay for first pass I would just simply + + align:start position:0% +okay for first pass I would just simply + + + align:start position:0% +okay for first pass I would just simply +try to make this go fast because for + + align:start position:0% +try to make this go fast because for + + + align:start position:0% +try to make this go fast because for +many of the moves that you're going to + + align:start position:0% +many of the moves that you're going to + + + align:start position:0% +many of the moves that you're going to +look at is going to be moving this pawn + + align:start position:0% +look at is going to be moving this pawn + + + align:start position:0% +look at is going to be moving this pawn +you know to there nothing changed + + align:start position:0% +you know to there nothing changed + + + align:start position:0% +you know to there nothing changed +there's no point in there stroking this + + align:start position:0% +there's no point in there stroking this + + + align:start position:0% +there's no point in there stroking this +out and cakung are the minimum etc + + align:start position:0% +out and cakung are the minimum etc + + + align:start position:0% +out and cakung are the minimum etc +because i didn't touch the laser path + + align:start position:0% +because i didn't touch the laser path + + + align:start position:0% +because i didn't touch the laser path +things are gonna touch a laser path are + + align:start position:0% +things are gonna touch a laser path are + + + align:start position:0% +things are gonna touch a laser path are +things that you move on or off the path + + align:start position:0% +things that you move on or off the path + + + align:start position:0% +things that you move on or off the path +so why bother okay and so if there's a + + align:start position:0% +so why bother okay and so if there's a + + + align:start position:0% +so why bother okay and so if there's a +clever way of hashing this you know so + + align:start position:0% +clever way of hashing this you know so + + + align:start position:0% +clever way of hashing this you know so +that you're caching it so that you can + + align:start position:0% +that you're caching it so that you can + + + align:start position:0% +that you're caching it so that you can +you know do things that's good too + + align:start position:0% +you know do things that's good too + + + align:start position:0% +you know do things that's good too +okay any questions about other things + + align:start position:0% +okay any questions about other things + + + align:start position:0% +okay any questions about other things +that could be done so another place I'll + + align:start position:0% +that could be done so another place I'll + + + align:start position:0% +that could be done so another place I'll +tell you that's a good idea to look at + + align:start position:0% +tell you that's a good idea to look at + + + align:start position:0% +tell you that's a good idea to look at +is especially once you get this + + align:start position:0% +is especially once you get this + + + align:start position:0% +is especially once you get this +heuristic operate a little bit faster is + + align:start position:0% +heuristic operate a little bit faster is + + + align:start position:0% +heuristic operate a little bit faster is +the sorting of moves okay is is actually + + align:start position:0% +the sorting of moves okay is is actually + + + align:start position:0% +the sorting of moves okay is is actually +pretty expensive + + align:start position:0% +pretty expensive + + + align:start position:0% +pretty expensive +okay what's the you know once you figure + + align:start position:0% +okay what's the you know once you figure + + + align:start position:0% +okay what's the you know once you figure +out here all the moves there are a lot + + align:start position:0% +out here all the moves there are a lot + + + align:start position:0% +out here all the moves there are a lot +of moves now you go through and you do a + + align:start position:0% +of moves now you go through and you do a + + + align:start position:0% +of moves now you go through and you do a +sort and if you think about it you know + + align:start position:0% +sort and if you think about it you know + + + align:start position:0% +sort and if you think about it you know +in a best move order tree sometimes you + + align:start position:0% +in a best move order tree sometimes you + + + align:start position:0% +in a best move order tree sometimes you +only explore one of those so why'd you + + align:start position:0% +only explore one of those so why'd you + + + align:start position:0% +only explore one of those so why'd you +bother sorting all of them okay on the + + align:start position:0% +bother sorting all of them okay on the + + + align:start position:0% +bother sorting all of them okay on the +other hand sometimes you do need to sort + + align:start position:0% +other hand sometimes you do need to sort + + + align:start position:0% +other hand sometimes you do need to sort +all of them so how you optimize that + + align:start position:0% +all of them so how you optimize that + + + align:start position:0% +all of them so how you optimize that +sort so that you don't waste time + + align:start position:0% +sort so that you don't waste time + + + align:start position:0% +sort so that you don't waste time +sorting stuff that you're not going to + + align:start position:0% +sorting stuff that you're not going to + + + align:start position:0% +sorting stuff that you're not going to +actually ever explore + + align:start position:0% +actually ever explore + + + align:start position:0% +actually ever explore +another opportunity for optimization + + align:start position:0% +another opportunity for optimization + + + align:start position:0% +another opportunity for optimization +okay yeah question the moves are sorted + + align:start position:0% +okay yeah question the moves are sorted + + + align:start position:0% +okay yeah question the moves are sorted +by these things like that there there's + + align:start position:0% +by these things like that there there's + + + align:start position:0% +by these things like that there there's +a sort key in there that represents a + + align:start position:0% +a sort key in there that represents a + + + align:start position:0% +a sort key in there that represents a +whole bunch of things like whether it + + align:start position:0% +whole bunch of things like whether it + + + align:start position:0% +whole bunch of things like whether it +was a killer if it's a killer or it's a + + align:start position:0% +was a killer if it's a killer or it's a + + + align:start position:0% +was a killer if it's a killer or it's a +transposition table value gets a very + + align:start position:0% +transposition table value gets a very + + + align:start position:0% +transposition table value gets a very +big value if it's a statistical thing + + align:start position:0% +big value if it's a statistical thing + + + align:start position:0% +big value if it's a statistical thing +that the history table says in + + align:start position:0% +that the history table says in + + + align:start position:0% +that the history table says in +historically this has been a pretty good + + align:start position:0% +historically this has been a pretty good + + + align:start position:0% +historically this has been a pretty good +move then you get another value and then + + align:start position:0% +move then you get another value and then + + + align:start position:0% +move then you get another value and then +exchanges get ordered and so forth so + + align:start position:0% +exchanges get ordered and so forth so + + + align:start position:0% +exchanges get ordered and so forth so +there's a bunch of things that are you + + align:start position:0% +there's a bunch of things that are you + + + align:start position:0% +there's a bunch of things that are you +know where where you end up with + + align:start position:0% +know where where you end up with + + + align:start position:0% +know where where you end up with +information and then it sorts those + + align:start position:0% +information and then it sorts those + + + align:start position:0% +information and then it sorts those +things okay so that's actually kind of + + align:start position:0% +things okay so that's actually kind of + + + align:start position:0% +things okay so that's actually kind of +complicated logic in terms of what the + + align:start position:0% +complicated logic in terms of what the + + + align:start position:0% +complicated logic in terms of what the +actual values are that are used there + + align:start position:0% +actual values are that are used there + + + align:start position:0% +actual values are that are used there +but the idea is you know here all the + + align:start position:0% +but the idea is you know here all the + + + align:start position:0% +but the idea is you know here all the +moves now let's figure out what's the + + align:start position:0% +moves now let's figure out what's the + + + align:start position:0% +moves now let's figure out what's the +best our best guess as to what they are + + align:start position:0% +best our best guess as to what they are + + + align:start position:0% +best our best guess as to what they are +most of the good moves are coming out of + + align:start position:0% +most of the good moves are coming out of + + + align:start position:0% +most of the good moves are coming out of +the transposition table right + + align:start position:0% +the transposition table right + + + align:start position:0% +the transposition table right +but sometimes the transposition table + + align:start position:0% +but sometimes the transposition table + + + align:start position:0% +but sometimes the transposition table +you know it's not it says it's not a + + align:start position:0% +you know it's not it says it's not a + + + align:start position:0% +you know it's not it says it's not a +very good move and there may be a better + + align:start position:0% +very good move and there may be a better + + + align:start position:0% +very good move and there may be a better +move okay so the quality of what you get + + align:start position:0% +move okay so the quality of what you get + + + align:start position:0% +move okay so the quality of what you get +out of transposition table is good but + + align:start position:0% +out of transposition table is good but + + + align:start position:0% +out of transposition table is good but +doesn't mean you know that that's always + + align:start position:0% +doesn't mean you know that that's always + + + align:start position:0% +doesn't mean you know that that's always +the best move okay yeah any other + + align:start position:0% +the best move okay yeah any other + + + align:start position:0% +the best move okay yeah any other +questions about what should be worked on + + align:start position:0% +questions about what should be worked on + + + align:start position:0% +questions about what should be worked on +let me just make sure I okay go ahead + + align:start position:0% + + + + align:start position:0% + +where does the sorting happen that + + align:start position:0% +where does the sorting happen that + + + align:start position:0% +where does the sorting happen that +happens at the I think at the move + + align:start position:0% +happens at the I think at the move + + + align:start position:0% +happens at the I think at the move +generation is that where it is is the + + align:start position:0% +generation is that where it is is the + + + align:start position:0% +generation is that where it is is the +sort in the move generation or is it in + + align:start position:0% +sort in the move generation or is it in + + + align:start position:0% +sort in the move generation or is it in +search I think it's in search I think + + align:start position:0% +search I think it's in search I think + + + align:start position:0% +search I think it's in search I think +you're right + + align:start position:0% +you're right + + + align:start position:0% +you're right +search calls move generation and then + + align:start position:0% +search calls move generation and then + + + align:start position:0% +search calls move generation and then +sorts it okay I think that's right + + align:start position:0% +sorts it okay I think that's right + + + align:start position:0% +sorts it okay I think that's right +yeah question + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +very tiny board implementation yes well + + align:start position:0% +very tiny board implementation yes well + + + align:start position:0% +very tiny board implementation yes well +as I say keep the old one around well I + + align:start position:0% +as I say keep the old one around well I + + + align:start position:0% +as I say keep the old one around well I +you use the old one while you're still + + align:start position:0% +you use the old one while you're still + + + align:start position:0% +you use the old one while you're still +getting the new one right okay it's also + + align:start position:0% +getting the new one right okay it's also + + + align:start position:0% +getting the new one right okay it's also +good to be able to go from old + + align:start position:0% +good to be able to go from old + + + align:start position:0% +good to be able to go from old +representation to new representation and + + align:start position:0% +representation to new representation and + + + align:start position:0% +representation to new representation and +having conversion functions okay but + + align:start position:0% +having conversion functions okay but + + + align:start position:0% +having conversion functions okay but +yeah making representation changes you + + align:start position:0% +yeah making representation changes you + + + align:start position:0% +yeah making representation changes you +know painful painful and is it's + + align:start position:0% +know painful painful and is it's + + + align:start position:0% +know painful painful and is it's +probably boy if there was one tool I + + align:start position:0% +probably boy if there was one tool I + + + align:start position:0% +probably boy if there was one tool I +would love that would automate stuff + + align:start position:0% +would love that would automate stuff + + + align:start position:0% +would love that would automate stuff +like that that would be it you know to + + align:start position:0% +like that that would be it you know to + + + align:start position:0% +like that that would be it you know to +be able to change representations of + + align:start position:0% +be able to change representations of + + + align:start position:0% +be able to change representations of +things and still have things go well I + + align:start position:0% +things and still have things go well I + + + align:start position:0% +things and still have things go well I +should have mentioned by the way the + + align:start position:0% +should have mentioned by the way the + + + align:start position:0% +should have mentioned by the way the +other representation besides bit board + + align:start position:0% +other representation besides bit board + + + align:start position:0% +other representation besides bit board +another one is just to keep a list of + + align:start position:0% +another one is just to keep a list of + + + align:start position:0% +another one is just to keep a list of +the pieces and their positions okay + + align:start position:0% +the pieces and their positions okay + + + align:start position:0% +the pieces and their positions okay +because that's going to be smaller than + + align:start position:0% +because that's going to be smaller than + + + align:start position:0% +because that's going to be smaller than +keeping this great big board okay then + + align:start position:0% +keeping this great big board okay then + + + align:start position:0% +keeping this great big board okay then +you keep this list sorted or do you not + + align:start position:0% +you keep this list sorted or do you not + + + align:start position:0% +you keep this list sorted or do you not +keep it sorted and do you but the + + align:start position:0% +keep it sorted and do you but the + + + align:start position:0% +keep it sorted and do you but the +advantage of that is particularly as the + + align:start position:0% +advantage of that is particularly as the + + + align:start position:0% +advantage of that is particularly as the +game goes on that list gets shorter and + + align:start position:0% +game goes on that list gets shorter and + + + align:start position:0% +game goes on that list gets shorter and +shorter okay and so so you're you know + + align:start position:0% +shorter okay and so so you're you know + + + align:start position:0% +shorter okay and so so you're you know +if you're doing less and manipulating + + align:start position:0% +if you're doing less and manipulating + + + align:start position:0% +if you're doing less and manipulating +the the board position that's a that's + + align:start position:0% +the the board position that's a that's + + + align:start position:0% +the the board position that's a that's +generally a good thing so for the board + + align:start position:0% +generally a good thing so for the board + + + align:start position:0% +generally a good thing so for the board +reputation my recommendation is to + + align:start position:0% +reputation my recommendation is to + + + align:start position:0% +reputation my recommendation is to +refactor all the board axes into a + + align:start position:0% +refactor all the board axes into a + + + align:start position:0% +refactor all the board axes into a +function and then you would still use + + align:start position:0% +function and then you would still use + + + align:start position:0% +function and then you would still use +the old representation in the function + + align:start position:0% +the old representation in the function + + + align:start position:0% +the old representation in the function +then you can validate that you refactor + + align:start position:0% +then you can validate that you refactor + + + align:start position:0% +then you can validate that you refactor +everything correctly and then you can + + align:start position:0% +everything correctly and then you can + + + align:start position:0% +everything correctly and then you can +easily change the board reputation to + + align:start position:0% +easily change the board reputation to + + + align:start position:0% +easily change the board reputation to +whatever you want and keep changing it + + align:start position:0% +whatever you want and keep changing it + + + align:start position:0% +whatever you want and keep changing it +without having to do a lot of refactor + + align:start position:0% +without having to do a lot of refactor + + + align:start position:0% +without having to do a lot of refactor +off that for that so find all the board + + align:start position:0% +off that for that so find all the board + + + align:start position:0% +off that for that so find all the board +accesses and refactor that to a function + + align:start position:0% +accesses and refactor that to a function + + + align:start position:0% +accesses and refactor that to a function +call before you modify it because the + + align:start position:0% +call before you modify it because the + + + align:start position:0% +call before you modify it because the +you know the compiler will inline that + + align:start position:0% +you know the compiler will inline that + + + align:start position:0% +you know the compiler will inline that +stuff so you know putting in a function + + align:start position:0% +stuff so you know putting in a function + + + align:start position:0% +stuff so you know putting in a function +call is not necessarily a bad idea and + + align:start position:0% +call is not necessarily a bad idea and + + + align:start position:0% +call is not necessarily a bad idea and +if it doesn't you can put it in a macro + + align:start position:0% +if it doesn't you can put it in a macro + + + align:start position:0% +if it doesn't you can put it in a macro +and it'll be effectively the same thing + + align:start position:0% +and it'll be effectively the same thing + + + align:start position:0% +and it'll be effectively the same thing +so great idea great idea okay yeah + + align:start position:0% +so great idea great idea okay yeah + + + align:start position:0% +so great idea great idea okay yeah +question + + align:start position:0% + + + + align:start position:0% + +testing testing testing you know if you + + align:start position:0% +testing testing testing you know if you + + + align:start position:0% +testing testing testing you know if you +can test and know that when you make a + + align:start position:0% +can test and know that when you make a + + + align:start position:0% +can test and know that when you make a +change it's correct you know and that + + align:start position:0% +change it's correct you know and that + + + align:start position:0% +change it's correct you know and that +you're not that's probably the number + + align:start position:0% +you're not that's probably the number + + + align:start position:0% +you're not that's probably the number +one hole that people go into is they + + align:start position:0% +one hole that people go into is they + + + align:start position:0% +one hole that people go into is they +don't test adequately so having good + + align:start position:0% +don't test adequately so having good + + + align:start position:0% +don't test adequately so having good +test infrastructure you know it's good + + align:start position:0% +test infrastructure you know it's good + + + align:start position:0% +test infrastructure you know it's good +yeah + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +as long as you're doing it + + align:start position:0% +as long as you're doing it + + + align:start position:0% +as long as you're doing it +deterministically yes that's because + + align:start position:0% +deterministically yes that's because + + + align:start position:0% +deterministically yes that's because +there's a randomness thing you turn off + + align:start position:0% +there's a randomness thing you turn off + + + align:start position:0% +there's a randomness thing you turn off +the ran there's a little variable you + + align:start position:0% +the ran there's a little variable you + + + align:start position:0% +the ran there's a little variable you +can set the variable to be not random + + align:start position:0% +can set the variable to be not random + + + align:start position:0% +can set the variable to be not random +and then it will be yes it's run + + align:start position:0% +and then it will be yes it's run + + + align:start position:0% +and then it will be yes it's run +serially and risk can give her the mic + + align:start position:0% +serially and risk can give her the mic + + + align:start position:0% +serially and risk can give her the mic +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +yeah juice + + align:start position:0% + + + + align:start position:0% + +yeah I got out of the opening phone I + + align:start position:0% +yeah I got out of the opening phone I + + + align:start position:0% +yeah I got out of the opening phone I +said the + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +yeah it shouldn't be if you run serially + + align:start position:0% +yeah it shouldn't be if you run serially + + + align:start position:0% +yeah it shouldn't be if you run serially +the only things that you know should be + + align:start position:0% +the only things that you know should be + + + align:start position:0% +the only things that you know should be +doing things as if you're doing I mean + + align:start position:0% +doing things as if you're doing I mean + + + align:start position:0% +doing things as if you're doing I mean +it should be deterministic if you turn + + align:start position:0% +it should be deterministic if you turn + + + align:start position:0% +it should be deterministic if you turn +off the the random number generator so + + align:start position:0% +off the the random number generator so + + + align:start position:0% +off the the random number generator so +as I say that's put in so that it will + + align:start position:0% +as I say that's put in so that it will + + + align:start position:0% +as I say that's put in so that it will +behave you know not predictably but + + align:start position:0% +behave you know not predictably but + + + align:start position:0% +behave you know not predictably but +that's exactly the kind of thing you + + align:start position:0% +that's exactly the kind of thing you + + + align:start position:0% +that's exactly the kind of thing you +want to find right at the beginning so + + align:start position:0% +want to find right at the beginning so + + + align:start position:0% +want to find right at the beginning so +as exactly things find out all the ways + + align:start position:0% +as exactly things find out all the ways + + + align:start position:0% +as exactly things find out all the ways +of making it deterministic and that + + align:start position:0% +of making it deterministic and that + + + align:start position:0% +of making it deterministic and that +would be really important for beta-2 + + align:start position:0% +would be really important for beta-2 + + + align:start position:0% +would be really important for beta-2 +okay so Thursday okay we have you know + + align:start position:0% +okay so Thursday okay we have you know + + + align:start position:0% +okay so Thursday okay we have you know +John Bentley legend of the field + + align:start position:0% +John Bentley legend of the field + + + align:start position:0% +John Bentley legend of the field +okay opportunity to meet a celebrity + + align:start position:0% +okay opportunity to meet a celebrity + + + align:start position:0% +okay opportunity to meet a celebrity +okay bring friends okay he's going to + + align:start position:0% +okay bring friends okay he's going to + + + align:start position:0% +okay bring friends okay he's going to +give a great lecture + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/iMz0LiqjFmE.txt b/iMz0LiqjFmE.txt new file mode 100644 index 0000000000000000000000000000000000000000..8adbff083fa7d2e0bcfc62ca146ebf3dd970f758 --- /dev/null +++ b/iMz0LiqjFmE.txt @@ -0,0 +1,7371 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT OpenCourseWare continue to + + align:start position:0% +will help MIT OpenCourseWare continue to + + + align:start position:0% +will help MIT OpenCourseWare continue to +offer high quality educational resources + + align:start position:0% +offer high quality educational resources + + + align:start position:0% +offer high quality educational resources +for free + + align:start position:0% +for free + + + align:start position:0% +for free +to make a donation or to view additional + + align:start position:0% +to make a donation or to view additional + + + align:start position:0% +to make a donation or to view additional +materials from hundreds of MIT courses + + align:start position:0% +materials from hundreds of MIT courses + + + align:start position:0% +materials from hundreds of MIT courses +visit MIT opencourseware at ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +so we were doing velocities and + + align:start position:0% +so we were doing velocities and + + + align:start position:0% +so we were doing velocities and +accelerations we came up with si + + align:start position:0% +accelerations we came up with si + + + align:start position:0% +accelerations we came up with si +continue to remind us talking about + + align:start position:0% +continue to remind us talking about + + + align:start position:0% +continue to remind us talking about +velocities and accelerations of a point + + align:start position:0% +velocities and accelerations of a point + + + align:start position:0% +velocities and accelerations of a point +with respect to another point to which + + align:start position:0% +with respect to another point to which + + + align:start position:0% +with respect to another point to which +we've attached make this point here to + + align:start position:0% +we've attached make this point here to + + + align:start position:0% +we've attached make this point here to +which we've attached a reference frame X + + align:start position:0% +which we've attached a reference frame X + + + align:start position:0% +which we've attached a reference frame X +prime Y prime Z prime and there's a + + align:start position:0% +prime Y prime Z prime and there's a + + + align:start position:0% +prime Y prime Z prime and there's a +vector that goes between these two and a + + align:start position:0% +vector that goes between these two and a + + + align:start position:0% +vector that goes between these two and a +vector that goes there so that we can + + align:start position:0% +vector that goes there so that we can + + + align:start position:0% +vector that goes there so that we can +say R of B with respect to O my inertial + + align:start position:0% +say R of B with respect to O my inertial + + + align:start position:0% +say R of B with respect to O my inertial +frame is R of a with respect to O plus R + + align:start position:0% +frame is R of a with respect to O plus R + + + align:start position:0% +frame is R of a with respect to O plus R +of B with respect to a these are all + + align:start position:0% +of B with respect to a these are all + + + align:start position:0% +of B with respect to a these are all +vectors and then from these we derive + + align:start position:0% +vectors and then from these we derive + + + align:start position:0% +vectors and then from these we derive +velocities and acceleration formulas and + + align:start position:0% +velocities and acceleration formulas and + + + align:start position:0% +velocities and acceleration formulas and +so we've come up with a couple of very + + align:start position:0% +so we've come up with a couple of very + + + align:start position:0% +so we've come up with a couple of very +handy formulas the velocity formula + + align:start position:0% +handy formulas the velocity formula + + + align:start position:0% +handy formulas the velocity formula +velocity of B with respect to O is the + + align:start position:0% +velocity of B with respect to O is the + + + align:start position:0% +velocity of B with respect to O is the +velocity of a with respect to O plus you + + align:start position:0% +velocity of a with respect to O plus you + + + align:start position:0% +velocity of a with respect to O plus you +have to take time derivative of this and + + align:start position:0% +have to take time derivative of this and + + + align:start position:0% +have to take time derivative of this and +so I'm going to give you just the + + align:start position:0% +so I'm going to give you just the + + + align:start position:0% +so I'm going to give you just the +general expression here just as a brief + + align:start position:0% +general expression here just as a brief + + + align:start position:0% +general expression here just as a brief +reminder it's the derivative of B with + + align:start position:0% +reminder it's the derivative of B with + + + align:start position:0% +reminder it's the derivative of B with +respect to a has seen in the a XYZ frame + + align:start position:0% +respect to a has seen in the a XYZ frame + + + align:start position:0% +respect to a has seen in the a XYZ frame +plus Omega with respect to O cross RBA + + align:start position:0% +plus Omega with respect to O cross RBA + + + align:start position:0% +plus Omega with respect to O cross RBA +these are all vectors so that's the ball + + align:start position:0% +these are all vectors so that's the ball + + + align:start position:0% +these are all vectors so that's the ball +that's the velocity formula remember + + align:start position:0% +that's the velocity formula remember + + + align:start position:0% +that's the velocity formula remember +this is the if you're in the frame + + align:start position:0% +this is the if you're in the frame + + + align:start position:0% +this is the if you're in the frame +rotating and translating with it this is + + align:start position:0% +rotating and translating with it this is + + + align:start position:0% +rotating and translating with it this is +the change of length of the vector and + + align:start position:0% +the change of length of the vector and + + + align:start position:0% +the change of length of the vector and +this then is the contribution to the + + align:start position:0% +this then is the contribution to the + + + align:start position:0% +this then is the contribution to the +velocity that you see in the fixed frame + + align:start position:0% +velocity that you see in the fixed frame + + + align:start position:0% +velocity that you see in the fixed frame +that comes from the rotation and we then + + align:start position:0% +that comes from the rotation and we then + + + align:start position:0% +that comes from the rotation and we then +got into polar coordinates and we found + + align:start position:0% +got into polar coordinates and we found + + + align:start position:0% +got into polar coordinates and we found +out that if you use polar coordinates + + align:start position:0% +out that if you use polar coordinates + + + align:start position:0% +out that if you use polar coordinates +then you can express this as the + + align:start position:0% +then you can express this as the + + + align:start position:0% +then you can express this as the +velocity of a with respect to O plus r + + align:start position:0% +velocity of a with respect to O plus r + + + align:start position:0% +velocity of a with respect to O plus r +dot R hat and I should really say + + align:start position:0% +dot R hat and I should really say + + + align:start position:0% +dot R hat and I should really say +cylindrical coordinates z dot + + align:start position:0% +cylindrical coordinates z dot + + + align:start position:0% +cylindrical coordinates z dot +k hat plus r theta dot theta hat so + + align:start position:0% +k hat plus r theta dot theta hat so + + + align:start position:0% +k hat plus r theta dot theta hat so +that's exactly the same thing this is + + align:start position:0% +that's exactly the same thing this is + + + align:start position:0% +that's exactly the same thing this is +full 3d vector notation this is a + + align:start position:0% +full 3d vector notation this is a + + + align:start position:0% +full 3d vector notation this is a +special case of a coordinate system + + align:start position:0% +special case of a coordinate system + + + align:start position:0% +special case of a coordinate system +which we call Koller coordinates and we + + align:start position:0% +which we call Koller coordinates and we + + + align:start position:0% +which we call Koller coordinates and we +have came up with another formula for + + align:start position:0% +have came up with another formula for + + + align:start position:0% +have came up with another formula for +accelerations the full 3d vector version + + align:start position:0% +accelerations the full 3d vector version + + + align:start position:0% +accelerations the full 3d vector version +of that a with respect to O plus this is + + align:start position:0% +of that a with respect to O plus this is + + + align:start position:0% +of that a with respect to O plus this is +the acceleration of B with respect to a + + align:start position:0% +the acceleration of B with respect to a + + + align:start position:0% +the acceleration of B with respect to a +but as seen in the a XYZ frame to Omega + + align:start position:0% +but as seen in the a XYZ frame to Omega + + + align:start position:0% +but as seen in the a XYZ frame to Omega +cross and this is the velocity as seen + + align:start position:0% +cross and this is the velocity as seen + + + align:start position:0% +cross and this is the velocity as seen +in the XYZ frame so these things this is + + align:start position:0% +in the XYZ frame so these things this is + + + align:start position:0% +in the XYZ frame so these things this is +no contribution from acceleration this + + align:start position:0% +no contribution from acceleration this + + + align:start position:0% +no contribution from acceleration this +is no contribution from acceleration + + align:start position:0% + + + + align:start position:0% + +plus Omega dot cross R b/a plus Omega + + align:start position:0% +plus Omega dot cross R b/a plus Omega + + + align:start position:0% +plus Omega dot cross R b/a plus Omega +cross Omega cross R b/a + + align:start position:0% + + + + align:start position:0% + +all vectors this is a movement of the + + align:start position:0% +all vectors this is a movement of the + + + align:start position:0% +all vectors this is a movement of the +frame the acceleration of it with + + align:start position:0% +frame the acceleration of it with + + + align:start position:0% +frame the acceleration of it with +respect to this is pure translation this + + align:start position:0% +respect to this is pure translation this + + + align:start position:0% +respect to this is pure translation this +is the acceleration of the dog on the + + align:start position:0% +is the acceleration of the dog on the + + + align:start position:0% +is the acceleration of the dog on the +merry-go-round with respect to the + + align:start position:0% +merry-go-round with respect to the + + + align:start position:0% +merry-go-round with respect to the +center of the coordinate system there + + align:start position:0% +center of the coordinate system there + + + align:start position:0% +center of the coordinate system there +does not involve rotation this is this + + align:start position:0% +does not involve rotation this is this + + + align:start position:0% +does not involve rotation this is this +term that we call Coriolis this is a + + align:start position:0% +term that we call Coriolis this is a + + + align:start position:0% +term that we call Coriolis this is a +term we call Euler this is the angular + + align:start position:0% +term we call Euler this is the angular + + + align:start position:0% +term we call Euler this is the angular +speed up of the system angular + + align:start position:0% +speed up of the system angular + + + align:start position:0% +speed up of the system angular +acceleration and this is centripetal + + align:start position:0% + + + + align:start position:0% + +and if you do these if you want to go to + + align:start position:0% +and if you do these if you want to go to + + + align:start position:0% +and if you do these if you want to go to +cylindrical coordinates and what we're + + align:start position:0% +cylindrical coordinates and what we're + + + align:start position:0% +cylindrical coordinates and what we're +going to do next is just do some + + align:start position:0% +going to do next is just do some + + + align:start position:0% +going to do next is just do some +applications here the acceleration of B + + align:start position:0% +applications here the acceleration of B + + + align:start position:0% +applications here the acceleration of B +with respect to O and cylindrical + + align:start position:0% +with respect to O and cylindrical + + + align:start position:0% +with respect to O and cylindrical +coordinates translation piece plus a now + + align:start position:0% +coordinates translation piece plus a now + + + align:start position:0% +coordinates translation piece plus a now +in cylindrical it's useful to group + + align:start position:0% +in cylindrical it's useful to group + + + align:start position:0% +in cylindrical it's useful to group +these so I'm going to put together this + + align:start position:0% +these so I'm going to put together this + + + align:start position:0% +these so I'm going to put together this +term and this term because they're both + + align:start position:0% +term and this term because they're both + + + align:start position:0% +term and this term because they're both +in the R hat direction and I'm going to + + align:start position:0% +in the R hat direction and I'm going to + + + align:start position:0% +in the R hat direction and I'm going to +put together these two terms because + + align:start position:0% +put together these two terms because + + + align:start position:0% +put together these two terms because +they're both in the theta hat direction + + align:start position:0% +they're both in the theta hat direction + + + align:start position:0% +they're both in the theta hat direction +and I need is e zwk because it's + + align:start position:0% +and I need is e zwk because it's + + + align:start position:0% +and I need is e zwk because it's +cylindrical and then I have the theta + + align:start position:0% +cylindrical and then I have the theta + + + align:start position:0% +cylindrical and then I have the theta +hat piece R theta double dot plus 2 r + + align:start position:0% +hat piece R theta double dot plus 2 r + + + align:start position:0% +hat piece R theta double dot plus 2 r +dot theta dot theta hat that's this is + + align:start position:0% +dot theta dot theta hat that's this is + + + align:start position:0% +dot theta dot theta hat that's this is +the same thing as this except this is + + align:start position:0% +the same thing as this except this is + + + align:start position:0% +the same thing as this except this is +expressed in cylindrical coordinates in + + align:start position:0% +expressed in cylindrical coordinates in + + + align:start position:0% +expressed in cylindrical coordinates in +cylindrical coordinates are particularly + + align:start position:0% +cylindrical coordinates are particularly + + + align:start position:0% +cylindrical coordinates are particularly +good for doing the kind of problems that + + align:start position:0% +good for doing the kind of problems that + + + align:start position:0% +good for doing the kind of problems that +are mostly done at the level of this + + align:start position:0% +are mostly done at the level of this + + + align:start position:0% +are mostly done at the level of this +course which we call planar motion + + align:start position:0% +course which we call planar motion + + + align:start position:0% +course which we call planar motion +problems confined to an XY plane and + + align:start position:0% +problems confined to an XY plane and + + + align:start position:0% +problems confined to an XY plane and +confined to single axis rotation in the + + align:start position:0% +confined to single axis rotation in the + + + align:start position:0% +confined to single axis rotation in the +Z which is this is a high coordinate + + align:start position:0% +Z which is this is a high coordinate + + + align:start position:0% +Z which is this is a high coordinate +system it's ideally suited to do + + align:start position:0% +system it's ideally suited to do + + + align:start position:0% +system it's ideally suited to do +problems like that and that's why we use + + align:start position:0% +problems like that and that's why we use + + + align:start position:0% +problems like that and that's why we use +it so now let's do let's do some + + align:start position:0% +it so now let's do let's do some + + + align:start position:0% +it so now let's do let's do some +examples and this gets into this is + + align:start position:0% +examples and this gets into this is + + + align:start position:0% +examples and this gets into this is +really quite a powerful now that you + + align:start position:0% +really quite a powerful now that you + + + align:start position:0% +really quite a powerful now that you +have these two equations you can do a + + align:start position:0% +have these two equations you can do a + + + align:start position:0% +have these two equations you can do a +lot of kinematics and dynamics + + align:start position:0% + + + + align:start position:0% + +so we started last time right at the + + align:start position:0% +so we started last time right at the + + + align:start position:0% +so we started last time right at the +very end I said okay let's do this + + align:start position:0% +very end I said okay let's do this + + + align:start position:0% +very end I said okay let's do this +problem really quickly right constant + + align:start position:0% +problem really quickly right constant + + + align:start position:0% +problem really quickly right constant +rotation rate constant radius no angular + + align:start position:0% +rotation rate constant radius no angular + + + align:start position:0% +rotation rate constant radius no angular +acceleration no change in length of the + + align:start position:0% +acceleration no change in length of the + + + align:start position:0% +acceleration no change in length of the +thing pretty simple problem and we + + align:start position:0% +thing pretty simple problem and we + + + align:start position:0% +thing pretty simple problem and we +exhibit it off really fast and I wanted + + align:start position:0% +exhibit it off really fast and I wanted + + + align:start position:0% +exhibit it off really fast and I wanted +to start there do that really quickly so + + align:start position:0% +to start there do that really quickly so + + + align:start position:0% +to start there do that really quickly so +this is my case one it's my ball on the + + align:start position:0% +this is my case one it's my ball on the + + + align:start position:0% +this is my case one it's my ball on the +string here's point a here's point B + + align:start position:0% +string here's point a here's point B + + + align:start position:0% +string here's point a here's point B +here's the theta hat direction R hat + + align:start position:0% +here's the theta hat direction R hat + + + align:start position:0% +here's the theta hat direction R hat +direction okay and it has some constant + + align:start position:0% +direction okay and it has some constant + + + align:start position:0% +direction okay and it has some constant +length R here so r dot R double dot R + + align:start position:0% +length R here so r dot R double dot R + + + align:start position:0% +length R here so r dot R double dot R +zero + + align:start position:0% +zero + + + align:start position:0% +zero +there's no also Z C dot Z double dot + + align:start position:0% +there's no also Z C dot Z double dot + + + align:start position:0% +there's no also Z C dot Z double dot +we're just no Z motion at all those are + + align:start position:0% +we're just no Z motion at all those are + + + align:start position:0% +we're just no Z motion at all those are +all 0 theta dot is a constant I'll call + + align:start position:0% +all 0 theta dot is a constant I'll call + + + align:start position:0% +all 0 theta dot is a constant I'll call +it cap Omega in the K hat direction + + align:start position:0% +it cap Omega in the K hat direction + + + align:start position:0% +it cap Omega in the K hat direction +right hand rule theta double dot zero so + + align:start position:0% +right hand rule theta double dot zero so + + + align:start position:0% +right hand rule theta double dot zero so +with the way the easy way to use these + + align:start position:0% +with the way the easy way to use these + + + align:start position:0% +with the way the easy way to use these +formulas is you just started knocking + + align:start position:0% +formulas is you just started knocking + + + align:start position:0% +formulas is you just started knocking +out all the terms that you don't need so + + align:start position:0% +out all the terms that you don't need so + + + align:start position:0% +out all the terms that you don't need so +but let's just to give you a little + + align:start position:0% +but let's just to give you a little + + + align:start position:0% +but let's just to give you a little +quick review of how to use these things + + align:start position:0% +quick review of how to use these things + + + align:start position:0% +quick review of how to use these things +let's use the vector full 3d version of + + align:start position:0% +let's use the vector full 3d version of + + + align:start position:0% +let's use the vector full 3d version of +velocity equation for a second the full + + align:start position:0% +velocity equation for a second the full + + + align:start position:0% +velocity equation for a second the full +3d version says the velocity of air is + + align:start position:0% +3d version says the velocity of air is + + + align:start position:0% +3d version says the velocity of air is +respect to O what's that in this problem + + align:start position:0% +respect to O what's that in this problem + + + align:start position:0% +respect to O what's that in this problem +that's not the translating term so I was + + align:start position:0% +that's not the translating term so I was + + + align:start position:0% +that's not the translating term so I was +standing still not going anywhere but if + + align:start position:0% +standing still not going anywhere but if + + + align:start position:0% +standing still not going anywhere but if +we're walking along I'd still spend that + + align:start position:0% +we're walking along I'd still spend that + + + align:start position:0% +we're walking along I'd still spend that +thing ok so this problem this term is + + align:start position:0% +thing ok so this problem this term is + + + align:start position:0% +thing ok so this problem this term is +zero this problem r dot + + align:start position:0% +zero this problem r dot + + + align:start position:0% +zero this problem r dot +let's go here what's this is the rate of + + align:start position:0% +let's go here what's this is the rate of + + + align:start position:0% +let's go here what's this is the rate of +change of the length of the string in + + align:start position:0% +change of the length of the string in + + + align:start position:0% +change of the length of the string in +the coordinate system of the string + + align:start position:0% +the coordinate system of the string + + + align:start position:0% +the coordinate system of the string +walking along so what's our dot okay so + + align:start position:0% +walking along so what's our dot okay so + + + align:start position:0% +walking along so what's our dot okay so +that terms 0 and Omega cross R b/a + + align:start position:0% +that terms 0 and Omega cross R b/a + + + align:start position:0% +that terms 0 and Omega cross R b/a +well R is in the our hat capital r r hat + + align:start position:0% +well R is in the our hat capital r r hat + + + align:start position:0% +well R is in the our hat capital r r hat +cross with omega a k right k cross r is + + align:start position:0% +cross with omega a k right k cross r is + + + align:start position:0% +cross with omega a k right k cross r is +k cross our hat theta hat so we get our + + align:start position:0% +k cross our hat theta hat so we get our + + + align:start position:0% +k cross our hat theta hat so we get our +familiar this first term is 0 the second + + align:start position:0% +familiar this first term is 0 the second + + + align:start position:0% +familiar this first term is 0 the second +term is 0 the third term we just get our + + align:start position:0% +term is 0 the third term we just get our + + + align:start position:0% +term is 0 the third term we just get our +R Omega in the theta hat direction we + + align:start position:0% +R Omega in the theta hat direction we + + + align:start position:0% +R Omega in the theta hat direction we +know that to be true the point I'm just + + align:start position:0% +know that to be true the point I'm just + + + align:start position:0% +know that to be true the point I'm just +trying to make here is you can always + + align:start position:0% +trying to make here is you can always + + + align:start position:0% +trying to make here is you can always +just fall back and use the vector + + align:start position:0% +just fall back and use the vector + + + align:start position:0% +just fall back and use the vector +formula full 3d vector formulas of both + + align:start position:0% +formula full 3d vector formulas of both + + + align:start position:0% +formula full 3d vector formulas of both +just plug it in and everything will just + + align:start position:0% +just plug it in and everything will just + + + align:start position:0% +just plug it in and everything will just +drop out you can also then go to these + + align:start position:0% +drop out you can also then go to these + + + align:start position:0% +drop out you can also then go to these +simply to the cylindrical coordinate + + align:start position:0% +simply to the cylindrical coordinate + + + align:start position:0% +simply to the cylindrical coordinate +terms when you happen to have it all + + align:start position:0% +terms when you happen to have it all + + + align:start position:0% +terms when you happen to have it all +expressed in those in coordinates of + + align:start position:0% +expressed in those in coordinates of + + + align:start position:0% +expressed in those in coordinates of +that kind of make it simpler for you + + align:start position:0% +that kind of make it simpler for you + + + align:start position:0% +that kind of make it simpler for you +okay so now let's quickly then do the + + align:start position:0% +okay so now let's quickly then do the + + + align:start position:0% +okay so now let's quickly then do the +acceleration of B with respect to O and + + align:start position:0% +acceleration of B with respect to O and + + + align:start position:0% +acceleration of B with respect to O and +let's use the formulation already in + + align:start position:0% +let's use the formulation already in + + + align:start position:0% +let's use the formulation already in +cylindrical coordinates what's a with + + align:start position:0% +cylindrical coordinates what's a with + + + align:start position:0% +cylindrical coordinates what's a with +respect to 0 + + align:start position:0% +respect to 0 + + + align:start position:0% +respect to 0 +what's our double dot how about the r + + align:start position:0% +what's our double dot how about the r + + + align:start position:0% +what's our double dot how about the r +theta dot squared term 0 or not nope + + align:start position:0% +theta dot squared term 0 or not nope + + + align:start position:0% +theta dot squared term 0 or not nope +let's go on z double dot r theta double + + align:start position:0% +let's go on z double dot r theta double + + + align:start position:0% +let's go on z double dot r theta double +dot r dot theta dot okay we only end up + + align:start position:0% +dot r dot theta dot okay we only end up + + + align:start position:0% +dot r dot theta dot okay we only end up +with one term actually i'm going to keep + + align:start position:0% +with one term actually i'm going to keep + + + align:start position:0% +with one term actually i'm going to keep +this one for a second able to respect oh + + align:start position:0% +this one for a second able to respect oh + + + align:start position:0% +this one for a second able to respect oh +- and we came up with our r theta dot + + align:start position:0% +- and we came up with our r theta dot + + + align:start position:0% +- and we came up with our r theta dot +squared R hat term I leave this in here + + align:start position:0% +squared R hat term I leave this in here + + + align:start position:0% +squared R hat term I leave this in here +because I actually don't don't have to + + align:start position:0% +because I actually don't don't have to + + + align:start position:0% +because I actually don't don't have to +say if I were if I want it now to do + + align:start position:0% +say if I were if I want it now to do + + + align:start position:0% +say if I were if I want it now to do +this problem if I ask you to do a + + align:start position:0% +this problem if I ask you to do a + + + align:start position:0% +this problem if I ask you to do a +problem where I'm doing this and I start + + align:start position:0% +problem where I'm doing this and I start + + + align:start position:0% +problem where I'm doing this and I start +accelerating do you know how to do it + + align:start position:0% +accelerating do you know how to do it + + + align:start position:0% +accelerating do you know how to do it +there's answers still there right + + align:start position:0% + + + + align:start position:0% + +all right + + align:start position:0% + + + + align:start position:0% + +what's let's do a quick free body + + align:start position:0% +what's let's do a quick free body + + + align:start position:0% +what's let's do a quick free body +diagram here's our mass my master + + align:start position:0% +diagram here's our mass my master + + + align:start position:0% +diagram here's our mass my master +coordinate system out here let's draw + + align:start position:0% +coordinate system out here let's draw + + + align:start position:0% +coordinate system out here let's draw +let's say it's you know right here at 90 + + align:start position:0% +let's say it's you know right here at 90 + + + align:start position:0% +let's say it's you know right here at 90 +degrees what are the external forces on + + align:start position:0% +degrees what are the external forces on + + + align:start position:0% +degrees what are the external forces on +the mass in this problem so there's + + align:start position:0% +the mass in this problem so there's + + + align:start position:0% +the mass in this problem so there's +tension in the string right okay so now + + align:start position:0% +tension in the string right okay so now + + + align:start position:0% +tension in the string right okay so now +this is a really trivially simple + + align:start position:0% +this is a really trivially simple + + + align:start position:0% +this is a really trivially simple +problem so the point of the emphasis I'm + + align:start position:0% +problem so the point of the emphasis I'm + + + align:start position:0% +problem so the point of the emphasis I'm +here is on the concept so now when + + align:start position:0% +here is on the concept so now when + + + align:start position:0% +here is on the concept so now when +you're asked to come up with an equation + + align:start position:0% +you're asked to come up with an equation + + + align:start position:0% +you're asked to come up with an equation +of motion or compute the forces on a + + align:start position:0% +of motion or compute the forces on a + + + align:start position:0% +of motion or compute the forces on a +mass Newton use Newton's second law F + + align:start position:0% +mass Newton use Newton's second law F + + + align:start position:0% +mass Newton use Newton's second law F +equals mass times acceleration you now + + align:start position:0% +equals mass times acceleration you now + + + align:start position:0% +equals mass times acceleration you now +have the complete 3d vector formulation + + align:start position:0% +have the complete 3d vector formulation + + + align:start position:0% +have the complete 3d vector formulation +for acceleration of a syst particle you + + align:start position:0% +for acceleration of a syst particle you + + + align:start position:0% +for acceleration of a syst particle you +know translating rotating coordinate + + align:start position:0% +know translating rotating coordinate + + + align:start position:0% +know translating rotating coordinate +system that's all you need to compute + + align:start position:0% +system that's all you need to compute + + + align:start position:0% +system that's all you need to compute +accelerations for lots and lots of + + align:start position:0% +accelerations for lots and lots of + + + align:start position:0% +accelerations for lots and lots of +difficult problems and so if you can + + align:start position:0% +difficult problems and so if you can + + + align:start position:0% +difficult problems and so if you can +write down the acceleration you say it's + + align:start position:0% +write down the acceleration you say it's + + + align:start position:0% +write down the acceleration you say it's +equal to what mask'd if you've + + align:start position:0% +equal to what mask'd if you've + + + align:start position:0% +equal to what mask'd if you've +multiplied mass times that acceleration + + align:start position:0% +multiplied mass times that acceleration + + + align:start position:0% +multiplied mass times that acceleration +what's that equal to the forces that + + align:start position:0% +what's that equal to the forces that + + + align:start position:0% +what's that equal to the forces that +must be acting on the system and that's + + align:start position:0% +must be acting on the system and that's + + + align:start position:0% +must be acting on the system and that's +the point here so now I want to know the + + align:start position:0% +the point here so now I want to know the + + + align:start position:0% +the point here so now I want to know the +forces on the system the summation of + + align:start position:0% +forces on the system the summation of + + + align:start position:0% +forces on the system the summation of +the external forces and then these are + + align:start position:0% +the external forces and then these are + + + align:start position:0% +the external forces and then these are +vectors and you can do them component by + + align:start position:0% +vectors and you can do them component by + + + align:start position:0% +vectors and you can do them component by +component the sum of the external forces + + align:start position:0% +component the sum of the external forces + + + align:start position:0% +component the sum of the external forces +in the R hat direction must be equal to + + align:start position:0% +in the R hat direction must be equal to + + + align:start position:0% +in the R hat direction must be equal to +the mass in this case just a particle + + align:start position:0% +the mass in this case just a particle + + + align:start position:0% +the mass in this case just a particle +times the acceleration of that particle + + align:start position:0% +times the acceleration of that particle + + + align:start position:0% +times the acceleration of that particle +and in this problem then that would be + + align:start position:0% +and in this problem then that would be + + + align:start position:0% +and in this problem then that would be +the mass times acceleration of a with + + align:start position:0% +the mass times acceleration of a with + + + align:start position:0% +the mass times acceleration of a with +respect to O minus R theta dot squared R + + align:start position:0% +respect to O minus R theta dot squared R + + + align:start position:0% +respect to O minus R theta dot squared R +hat + + align:start position:0% +hat + + + align:start position:0% +hat +and this would have to be the are comp + + align:start position:0% +and this would have to be the are comp + + + align:start position:0% +and this would have to be the are comp +they are hat component of this thing + + align:start position:0% +they are hat component of this thing + + + align:start position:0% +they are hat component of this thing +right I've said I just want the are + + align:start position:0% +right I've said I just want the are + + + align:start position:0% +right I've said I just want the are +component I'd have to figure out if I + + align:start position:0% +component I'd have to figure out if I + + + align:start position:0% +component I'd have to figure out if I +was running along if I had a in the same + + align:start position:0% +was running along if I had a in the same + + + align:start position:0% +was running along if I had a in the same +direction as our hat what part of that + + align:start position:0% +direction as our hat what part of that + + + align:start position:0% +direction as our hat what part of that +accelerations in that direction that + + align:start position:0% +accelerations in that direction that + + + align:start position:0% +accelerations in that direction that +would come here if there's zero is make + + align:start position:0% +would come here if there's zero is make + + + align:start position:0% +would come here if there's zero is make +it zero so let's just say no let's just + + align:start position:0% +it zero so let's just say no let's just + + + align:start position:0% +it zero so let's just say no let's just +let the acceleration of a with respect + + align:start position:0% +let the acceleration of a with respect + + + align:start position:0% +let the acceleration of a with respect +to O be zero then that says the sum of + + align:start position:0% +to O be zero then that says the sum of + + + align:start position:0% +to O be zero then that says the sum of +the forces in the r direction is equal + + align:start position:0% +the forces in the r direction is equal + + + align:start position:0% +the forces in the r direction is equal +to the mass minus m r theta dot squared + + align:start position:0% +to the mass minus m r theta dot squared + + + align:start position:0% +to the mass minus m r theta dot squared +and if we were to draw a Freebody + + align:start position:0% +and if we were to draw a Freebody + + + align:start position:0% +and if we were to draw a Freebody +diagram we would find out that ah there + + align:start position:0% +diagram we would find out that ah there + + + align:start position:0% +diagram we would find out that ah there +must be a tension on the string pulling + + align:start position:0% +must be a tension on the string pulling + + + align:start position:0% +must be a tension on the string pulling +it on the mass sufficient to give it the + + align:start position:0% +it on the mass sufficient to give it the + + + align:start position:0% +it on the mass sufficient to give it the +acceleration that you've computed so + + align:start position:0% +acceleration that you've computed so + + + align:start position:0% +acceleration that you've computed so +every problem when you're asked to + + align:start position:0% +every problem when you're asked to + + + align:start position:0% +every problem when you're asked to +compute the force or the next step up + + align:start position:0% +compute the force or the next step up + + + align:start position:0% +compute the force or the next step up +find the equation of motion the equation + + align:start position:0% +find the equation of motion the equation + + + align:start position:0% +find the equation of motion the equation +of motion is just spin it it's just you + + align:start position:0% +of motion is just spin it it's just you + + + align:start position:0% +of motion is just spin it it's just you +know writing this thing out okay the now + + align:start position:0% +know writing this thing out okay the now + + + align:start position:0% +know writing this thing out okay the now +okay I want to move on to a more + + align:start position:0% +okay I want to move on to a more + + + align:start position:0% +okay I want to move on to a more +interesting problem + + align:start position:0% + + + + align:start position:0% + +all right I'm going to do I want to do + + align:start position:0% +all right I'm going to do I want to do + + + align:start position:0% +all right I'm going to do I want to do +this problem so it's a hollow tube and + + align:start position:0% +this problem so it's a hollow tube and + + + align:start position:0% +this problem so it's a hollow tube and +we're going to look at things like what + + align:start position:0% +we're going to look at things like what + + + align:start position:0% +we're going to look at things like what +happened put a ping-pong ball in it okay + + align:start position:0% +happened put a ping-pong ball in it okay + + + align:start position:0% +happened put a ping-pong ball in it okay +and if I swing this tube around ping + + align:start position:0% +and if I swing this tube around ping + + + align:start position:0% +and if I swing this tube around ping +pong ball is going to come out right + + align:start position:0% + + + + align:start position:0% + +okay there must be some forces on that + + align:start position:0% +okay there must be some forces on that + + + align:start position:0% +okay there must be some forces on that +thing to cause it to come out there must + + align:start position:0% +thing to cause it to come out there must + + + align:start position:0% +thing to cause it to come out there must +be some accelerations on that thing so + + align:start position:0% +be some accelerations on that thing so + + + align:start position:0% +be some accelerations on that thing so +if I could conceivably have an R a theta + + align:start position:0% +if I could conceivably have an R a theta + + + align:start position:0% +if I could conceivably have an R a theta +double dot acceleration it certainly is + + align:start position:0% +double dot acceleration it certainly is + + + align:start position:0% +double dot acceleration it certainly is +going to have theta dot rotation rates + + align:start position:0% +going to have theta dot rotation rates + + + align:start position:0% +going to have theta dot rotation rates +the balls allowed to move there can be + + align:start position:0% +the balls allowed to move there can be + + + align:start position:0% +the balls allowed to move there can be +non zero R dots are double dots a lot + + align:start position:0% +non zero R dots are double dots a lot + + + align:start position:0% +non zero R dots are double dots a lot +going on inside of this simple little - + + align:start position:0% +going on inside of this simple little - + + + align:start position:0% +going on inside of this simple little - +all right so let's that's what I want to + + align:start position:0% +all right so let's that's what I want to + + + align:start position:0% +all right so let's that's what I want to +figure out let's see if we can come up + + align:start position:0% +figure out let's see if we can come up + + + align:start position:0% +figure out let's see if we can come up +with a model for this problem + + align:start position:0% + + + + align:start position:0% + +so here's my z-axis I have a rotation + + align:start position:0% +so here's my z-axis I have a rotation + + + align:start position:0% +so here's my z-axis I have a rotation +around it some theta dot k hat direction + + align:start position:0% +around it some theta dot k hat direction + + + align:start position:0% +around it some theta dot k hat direction +here's my tube it's rotating around so + + align:start position:0% +here's my tube it's rotating around so + + + align:start position:0% +here's my tube it's rotating around so +this is sort of a side view your view of + + align:start position:0% +this is sort of a side view your view of + + + align:start position:0% +this is sort of a side view your view of +the tube here's a ping-pong ball in + + align:start position:0% +the tube here's a ping-pong ball in + + + align:start position:0% +the tube here's a ping-pong ball in +there and I'm going to I'm going to + + align:start position:0% +there and I'm going to I'm going to + + + align:start position:0% +there and I'm going to I'm going to +idealize that ping-pong ball as a for a + + align:start position:0% +idealize that ping-pong ball as a for a + + + align:start position:0% +idealize that ping-pong ball as a for a +minute a little more general problem I + + align:start position:0% +minute a little more general problem I + + + align:start position:0% +minute a little more general problem I +have got let's say I have kind of a nut + + align:start position:0% +have got let's say I have kind of a nut + + + align:start position:0% +have got let's say I have kind of a nut +on this thing a disc something on the + + align:start position:0% +on this thing a disc something on the + + + align:start position:0% +on this thing a disc something on the +outs hanging on to the outside and I can + + align:start position:0% +outs hanging on to the outside and I can + + + align:start position:0% +outs hanging on to the outside and I can +control the rate at which the speed at + + align:start position:0% +control the rate at which the speed at + + + align:start position:0% +control the rate at which the speed at +which this thing goes out ping-pong ball + + align:start position:0% +which this thing goes out ping-pong ball + + + align:start position:0% +which this thing goes out ping-pong ball +that's just that's a this is going to be + + align:start position:0% +that's just that's a this is going to be + + + align:start position:0% +that's just that's a this is going to be +an application of this but I want to be + + align:start position:0% +an application of this but I want to be + + + align:start position:0% +an application of this but I want to be +able to do several other versions like + + align:start position:0% +able to do several other versions like + + + align:start position:0% +able to do several other versions like +can like make the speed constant for a + + align:start position:0% +can like make the speed constant for a + + + align:start position:0% +can like make the speed constant for a +second okay and looking down on this + + align:start position:0% +second okay and looking down on this + + + align:start position:0% +second okay and looking down on this +thing + + align:start position:0% +thing + + + align:start position:0% +thing +top view here's our initial frame maybe + + align:start position:0% +top view here's our initial frame maybe + + + align:start position:0% +top view here's our initial frame maybe +out here like this here's my mass so in + + align:start position:0% +out here like this here's my mass so in + + + align:start position:0% +out here like this here's my mass so in +polar coordinates here is your theta the + + align:start position:0% +polar coordinates here is your theta the + + + align:start position:0% +polar coordinates here is your theta the +R is this this is your R hat this is + + align:start position:0% +R is this this is your R hat this is + + + align:start position:0% +R is this this is your R hat this is +your theta hat directions okay I'm going + + align:start position:0% +your theta hat directions okay I'm going + + + align:start position:0% +your theta hat directions okay I'm going +to let the velocity of a with respect to + + align:start position:0% +to let the velocity of a with respect to + + + align:start position:0% +to let the velocity of a with respect to +O be zero so there's no translation of + + align:start position:0% +O be zero so there's no translation of + + + align:start position:0% +O be zero so there's no translation of +this system and z z dot z double dot + + align:start position:0% +this system and z z dot z double dot + + + align:start position:0% +this system and z z dot z double dot +those are all zero nothing's happening + + align:start position:0% +those are all zero nothing's happening + + + align:start position:0% +those are all zero nothing's happening +in the z direction so I want to first + + align:start position:0% +in the z direction so I want to first + + + align:start position:0% +in the z direction so I want to first +compute the velocity of B with respect + + align:start position:0% +compute the velocity of B with respect + + + align:start position:0% +compute the velocity of B with respect +to O and you got to be able to do that + + align:start position:0% +to O and you got to be able to do that + + + align:start position:0% +to O and you got to be able to do that +sort of by inspection right it comes + + align:start position:0% +sort of by inspection right it comes + + + align:start position:0% +sort of by inspection right it comes +only from oh I haven't told you now what + + align:start position:0% +only from oh I haven't told you now what + + + align:start position:0% +only from oh I haven't told you now what +do I want to hope make happen in this + + align:start position:0% +do I want to hope make happen in this + + + align:start position:0% +do I want to hope make happen in this +problem I want to let + + align:start position:0% +problem I want to let + + + align:start position:0% +problem I want to let +our dot it's going to be some VR and + + align:start position:0% +our dot it's going to be some VR and + + + align:start position:0% +our dot it's going to be some VR and +it's constant I'm not going to go quite + + align:start position:0% +it's constant I'm not going to go quite + + + align:start position:0% +it's constant I'm not going to go quite +to my ping pong shooter here yet I'm + + align:start position:0% +to my ping pong shooter here yet I'm + + + align:start position:0% +to my ping pong shooter here yet I'm +going to do a slightly simpler problem + + align:start position:0% +going to do a slightly simpler problem + + + align:start position:0% +going to do a slightly simpler problem +first so this is a constant that means + + align:start position:0% +first so this is a constant that means + + + align:start position:0% +first so this is a constant that means +our double dot is zero so this thing is + + align:start position:0% +our double dot is zero so this thing is + + + align:start position:0% +our double dot is zero so this thing is +just like let's say you had threads on + + align:start position:0% +just like let's say you had threads on + + + align:start position:0% +just like let's say you had threads on +this thing and it's a screw and it's + + align:start position:0% +this thing and it's a screw and it's + + + align:start position:0% +this thing and it's a screw and it's +just moving its way out at a constant + + align:start position:0% +just moving its way out at a constant + + + align:start position:0% +just moving its way out at a constant +rate and I'm going to have constant + + align:start position:0% +rate and I'm going to have constant + + + align:start position:0% +rate and I'm going to have constant +angular so theta dot and I'll call that + + align:start position:0% +angular so theta dot and I'll call that + + + align:start position:0% +angular so theta dot and I'll call that +cap Omega K so the angular rate is also + + align:start position:0% +cap Omega K so the angular rate is also + + + align:start position:0% +cap Omega K so the angular rate is also +constant all right if that's the case + + align:start position:0% +constant all right if that's the case + + + align:start position:0% +constant all right if that's the case +can you tell me so what to be with V of + + align:start position:0% +can you tell me so what to be with V of + + + align:start position:0% +can you tell me so what to be with V of +B with respect to my fixed frame oh well + + align:start position:0% +B with respect to my fixed frame oh well + + + align:start position:0% +B with respect to my fixed frame oh well +any time you're not sure you go back to + + align:start position:0% +any time you're not sure you go back to + + + align:start position:0% +any time you're not sure you go back to +this formula throw out terms and no Z + + align:start position:0% +this formula throw out terms and no Z + + + align:start position:0% +this formula throw out terms and no Z +dot term this is constant this is zero + + align:start position:0% +dot term this is constant this is zero + + + align:start position:0% +dot term this is constant this is zero +zero zero you have this term some VR and + + align:start position:0% +zero zero you have this term some VR and + + + align:start position:0% +zero zero you have this term some VR and +the R hat direction you have this term + + align:start position:0% +the R hat direction you have this term + + + align:start position:0% +the R hat direction you have this term +right wherever it happens to be in the + + align:start position:0% +right wherever it happens to be in the + + + align:start position:0% +right wherever it happens to be in the +theta hat direction okay + + align:start position:0% + + + + align:start position:0% + +our dot R hat Direction plus R theta dot + + align:start position:0% +our dot R hat Direction plus R theta dot + + + align:start position:0% +our dot R hat Direction plus R theta dot +in the theta hat direction + + align:start position:0% +in the theta hat direction + + + align:start position:0% +in the theta hat direction +okay we need acceleration next V with + + align:start position:0% +okay we need acceleration next V with + + + align:start position:0% +okay we need acceleration next V with +respect to O and now you crank through + + align:start position:0% +respect to O and now you crank through + + + align:start position:0% +respect to O and now you crank through +the terms again this time first term is + + align:start position:0% +the terms again this time first term is + + + align:start position:0% +the terms again this time first term is +zero second term is zero because it's + + align:start position:0% +zero second term is zero because it's + + + align:start position:0% +zero second term is zero because it's +constant third term is definitely not + + align:start position:0% +constant third term is definitely not + + + align:start position:0% +constant third term is definitely not +zero four three zero fifth term zero + + align:start position:0% +zero four three zero fifth term zero + + + align:start position:0% +zero four three zero fifth term zero +this term not zero so let me just write + + align:start position:0% +this term not zero so let me just write + + + align:start position:0% +this term not zero so let me just write +them so you get a minus R theta dot + + align:start position:0% +them so you get a minus R theta dot + + + align:start position:0% +them so you get a minus R theta dot +squared R hat and that's the radial + + align:start position:0% +squared R hat and that's the radial + + + align:start position:0% +squared R hat and that's the radial +Direction term plus 2 r dot theta dot + + align:start position:0% +Direction term plus 2 r dot theta dot + + + align:start position:0% +Direction term plus 2 r dot theta dot +theta ad that's the accelerations so you + + align:start position:0% +theta ad that's the accelerations so you + + + align:start position:0% +theta ad that's the accelerations so you +have an acceleration now in the R hat + + align:start position:0% +have an acceleration now in the R hat + + + align:start position:0% +have an acceleration now in the R hat +direction and in the theta hat direction + + align:start position:0% +direction and in the theta hat direction + + + align:start position:0% +direction and in the theta hat direction +if there's acceleration to those + + align:start position:0% +if there's acceleration to those + + + align:start position:0% +if there's acceleration to those +directions there must be forces F equals + + align:start position:0% +directions there must be forces F equals + + + align:start position:0% +directions there must be forces F equals +Newton's second law now says you know + + align:start position:0% +Newton's second law now says you know + + + align:start position:0% +Newton's second law now says you know +again the force is the mass times the + + align:start position:0% +again the force is the mass times the + + + align:start position:0% +again the force is the mass times the +acceleration and this is a vector this + + align:start position:0% +acceleration and this is a vector this + + + align:start position:0% +acceleration and this is a vector this +is a vector it has two components and + + align:start position:0% +is a vector it has two components and + + + align:start position:0% +is a vector it has two components and +the nice thing about these Newton's laws + + align:start position:0% +the nice thing about these Newton's laws + + + align:start position:0% +the nice thing about these Newton's laws +and vectors you can break the problems + + align:start position:0% +and vectors you can break the problems + + + align:start position:0% +and vectors you can break the problems +down into their vector components and + + align:start position:0% +down into their vector components and + + + align:start position:0% +down into their vector components and +treat the our direction as one equation + + align:start position:0% +treat the our direction as one equation + + + align:start position:0% +treat the our direction as one equation +of motion in the theta direction as a + + align:start position:0% +of motion in the theta direction as a + + + align:start position:0% +of motion in the theta direction as a +separate one + + align:start position:0% +separate one + + + align:start position:0% +separate one +so we might want to draw a Freebody + + align:start position:0% +so we might want to draw a Freebody + + + align:start position:0% +so we might want to draw a Freebody +diagram here's this block working its + + align:start position:0% +diagram here's this block working its + + + align:start position:0% +diagram here's this block working its +way out we know that there's probably + + align:start position:0% +way out we know that there's probably + + + align:start position:0% +way out we know that there's probably +some axial force I'm just going to call + + align:start position:0% +some axial force I'm just going to call + + + align:start position:0% +some axial force I'm just going to call +it t and there's some other unknown + + align:start position:0% +it t and there's some other unknown + + + align:start position:0% +it t and there's some other unknown +force here in the theta hat direction so + + align:start position:0% +force here in the theta hat direction so + + + align:start position:0% +force here in the theta hat direction so +this is my theta hat I've drawn this + + align:start position:0% +this is my theta hat I've drawn this + + + align:start position:0% +this is my theta hat I've drawn this +just intentionally in the positive R hat + + align:start position:0% +just intentionally in the positive R hat + + + align:start position:0% +just intentionally in the positive R hat +direction the sign that it comes out + + align:start position:0% +direction the sign that it comes out + + + align:start position:0% +direction the sign that it comes out +will tell us which direction it really + + align:start position:0% +will tell us which direction it really + + + align:start position:0% +will tell us which direction it really +is if you if you're not certain just + + align:start position:0% +is if you if you're not certain just + + + align:start position:0% +is if you if you're not certain just +draw it positive in the positive R hat + + align:start position:0% +draw it positive in the positive R hat + + + align:start position:0% +draw it positive in the positive R hat +direction and this is the that's your + + align:start position:0% +direction and this is the that's your + + + align:start position:0% +direction and this is the that's your +free body diagram if I wanted to put + + align:start position:0% +free body diagram if I wanted to put + + + align:start position:0% +free body diagram if I wanted to put +gravity in there + + align:start position:0% +gravity in there + + + align:start position:0% +gravity in there +I might have but + + align:start position:0% +I might have but + + + align:start position:0% +I might have but +we're doing this in the horizontal plane + + align:start position:0% +we're doing this in the horizontal plane + + + align:start position:0% +we're doing this in the horizontal plane +we'll call gravity is in and out this + + align:start position:0% +we'll call gravity is in and out this + + + align:start position:0% +we'll call gravity is in and out this +way it's in the Z direction and we know + + align:start position:0% +way it's in the Z direction and we know + + + align:start position:0% +way it's in the Z direction and we know +it's constrained can't move Z double dot + + align:start position:0% +it's constrained can't move Z double dot + + + align:start position:0% +it's constrained can't move Z double dot +zero so there's probably some there's + + align:start position:0% +zero so there's probably some there's + + + align:start position:0% +zero so there's probably some there's +certainly a support force that picks up + + align:start position:0% +certainly a support force that picks up + + + align:start position:0% +certainly a support force that picks up +the weight but this is in our horizontal + + align:start position:0% +the weight but this is in our horizontal + + + align:start position:0% +the weight but this is in our horizontal +plane + + align:start position:0% +plane + + + align:start position:0% +plane +there's your Freebody diagram and we can + + align:start position:0% +there's your Freebody diagram and we can + + + align:start position:0% +there's your Freebody diagram and we can +write two equations to solve for these + + align:start position:0% +write two equations to solve for these + + + align:start position:0% +write two equations to solve for these +things so some some of the forces in the + + align:start position:0% +things so some some of the forces in the + + + align:start position:0% +things so some some of the forces in the +R hat direction is T and that must be + + align:start position:0% +R hat direction is T and that must be + + + align:start position:0% +R hat direction is T and that must be +equal to the mass times the acceleration + + align:start position:0% +equal to the mass times the acceleration + + + align:start position:0% +equal to the mass times the acceleration +in the R - M R theta dot squared in the + + align:start position:0% +in the R - M R theta dot squared in the + + + align:start position:0% +in the R - M R theta dot squared in the +R hat direction + + align:start position:0% +R hat direction + + + align:start position:0% +R hat direction +sure enough the tension has to go has to + + align:start position:0% +sure enough the tension has to go has to + + + align:start position:0% +sure enough the tension has to go has to +pull inwards in the minus our hat + + align:start position:0% +pull inwards in the minus our hat + + + align:start position:0% +pull inwards in the minus our hat +direction and that's the fold result + + align:start position:0% + + + + align:start position:0% + +where are they okay so if this and bring + + align:start position:0% +where are they okay so if this and bring + + + align:start position:0% +where are they okay so if this and bring +the ball to the outside where you can + + align:start position:0% +the ball to the outside where you can + + + align:start position:0% +the ball to the outside where you can +see it this thing is going in this + + align:start position:0% +see it this thing is going in this + + + align:start position:0% +see it this thing is going in this +direction right horizontal plane XY + + align:start position:0% +direction right horizontal plane XY + + + align:start position:0% +direction right horizontal plane XY +plane it's moving it's fixed rate out + + align:start position:0% +plane it's moving it's fixed rate out + + + align:start position:0% +plane it's moving it's fixed rate out +all right so it's speed when it's in + + align:start position:0% +all right so it's speed when it's in + + + align:start position:0% +all right so it's speed when it's in +here is our over to Omega in that + + align:start position:0% +here is our over to Omega in that + + + align:start position:0% +here is our over to Omega in that +direction when a speed wind is out here + + align:start position:0% +direction when a speed wind is out here + + + align:start position:0% +direction when a speed wind is out here +it's our Omega in that direction so + + align:start position:0% +it's our Omega in that direction so + + + align:start position:0% +it's our Omega in that direction so +clearly it's it's picking up speed right + + align:start position:0% +clearly it's it's picking up speed right + + + align:start position:0% +clearly it's it's picking up speed right +if it's picking up speed is the picking + + align:start position:0% +if it's picking up speed is the picking + + + align:start position:0% +if it's picking up speed is the picking +up kinetic energy is their work being + + align:start position:0% +up kinetic energy is their work being + + + align:start position:0% +up kinetic energy is their work being +done on it somehow to build up that + + align:start position:0% +done on it somehow to build up that + + + align:start position:0% +done on it somehow to build up that +energy so there must be some forces at + + align:start position:0% +energy so there must be some forces at + + + align:start position:0% +energy so there must be some forces at +play okay so there's a there's a normal + + align:start position:0% +play okay so there's a there's a normal + + + align:start position:0% +play okay so there's a there's a normal +force from the wall of this thing + + align:start position:0% +force from the wall of this thing + + + align:start position:0% +force from the wall of this thing +pushing this ball sideways to speed it + + align:start position:0% +pushing this ball sideways to speed it + + + align:start position:0% +pushing this ball sideways to speed it +up for sure that's one force and the + + align:start position:0% +up for sure that's one force and the + + + align:start position:0% +up for sure that's one force and the +other force is because I'm cannot + + align:start position:0% +other force is because I'm cannot + + + align:start position:0% +other force is because I'm cannot +allowing this thing just to go freely + + align:start position:0% +allowing this thing just to go freely + + + align:start position:0% +allowing this thing just to go freely +out I'm constraining it to constant + + align:start position:0% +out I'm constraining it to constant + + + align:start position:0% +out I'm constraining it to constant +speed out it would really like to go a + + align:start position:0% +speed out it would really like to go a + + + align:start position:0% +speed out it would really like to go a +lot faster than that so what's holding + + align:start position:0% +lot faster than that so what's holding + + + align:start position:0% +lot faster than that so what's holding +it back it's at any instant of time it + + align:start position:0% +it back it's at any instant of time it + + + align:start position:0% +it back it's at any instant of time it +has centripetal acceleration and what's + + align:start position:0% +has centripetal acceleration and what's + + + align:start position:0% +has centripetal acceleration and what's +whole what's keep making it go in the + + align:start position:0% +whole what's keep making it go in the + + + align:start position:0% +whole what's keep making it go in the +circle is a force that is in this case + + align:start position:0% +circle is a force that is in this case + + + align:start position:0% +circle is a force that is in this case +if that were a nut with threads it + + align:start position:0% +if that were a nut with threads it + + + align:start position:0% +if that were a nut with threads it +forces and the threads are applying to + + align:start position:0% +forces and the threads are applying to + + + align:start position:0% +forces and the threads are applying to +the knot to keep it from getting from + + align:start position:0% +the knot to keep it from getting from + + + align:start position:0% +the knot to keep it from getting from +running away + + align:start position:0% + + + + align:start position:0% + +well I've broken down I've chosen I the + + align:start position:0% +well I've broken down I've chosen I the + + + align:start position:0% +well I've broken down I've chosen I the +total force acting on this thing is some + + align:start position:0% +total force acting on this thing is some + + + align:start position:0% +total force acting on this thing is some +combination of a force in that direction + + align:start position:0% +combination of a force in that direction + + + align:start position:0% +combination of a force in that direction +and a combination in the axial direction + + align:start position:0% +and a combination in the axial direction + + + align:start position:0% +and a combination in the axial direction +so it has some net net vector direction + + align:start position:0% +so it has some net net vector direction + + + align:start position:0% +so it has some net net vector direction +that's neither this nor that right but + + align:start position:0% + + + + align:start position:0% + +so this this thing is rotating about + + align:start position:0% +so this this thing is rotating about + + + align:start position:0% +so this this thing is rotating about +some center over here right so this is + + align:start position:0% +some center over here right so this is + + + align:start position:0% +some center over here right so this is +theta dot theta is going in this + + align:start position:0% +theta dot theta is going in this + + + align:start position:0% +theta dot theta is going in this +direction theta dot and it's just we've + + align:start position:0% +direction theta dot and it's just we've + + + align:start position:0% +direction theta dot and it's just we've +chosen a coordinate system that has unit + + align:start position:0% +chosen a coordinate system that has unit + + + align:start position:0% +chosen a coordinate system that has unit +vectors R hat and theta hat and so it + + align:start position:0% +vectors R hat and theta hat and so it + + + align:start position:0% +vectors R hat and theta hat and so it +makes sense we can express the + + align:start position:0% +makes sense we can express the + + + align:start position:0% +makes sense we can express the +acceleration in terms of those two + + align:start position:0% +acceleration in terms of those two + + + align:start position:0% +acceleration in terms of those two +components it makes sense to express the + + align:start position:0% +components it makes sense to express the + + + align:start position:0% +components it makes sense to express the +forces in the same direction so I've + + align:start position:0% +forces in the same direction so I've + + + align:start position:0% +forces in the same direction so I've +just arbitrarily said I have some + + align:start position:0% +just arbitrarily said I have some + + + align:start position:0% +just arbitrarily said I have some +unknown force that's in this direction + + align:start position:0% +unknown force that's in this direction + + + align:start position:0% +unknown force that's in this direction +and I have another unknown force in that + + align:start position:0% +and I have another unknown force in that + + + align:start position:0% +and I have another unknown force in that +direction and but I know that that I'm + + align:start position:0% +direction and but I know that that I'm + + + align:start position:0% +direction and but I know that that I'm +saying there account for all forces in + + align:start position:0% +saying there account for all forces in + + + align:start position:0% +saying there account for all forces in +this direction whatever their source + + align:start position:0% +this direction whatever their source + + + align:start position:0% +this direction whatever their source +that tells me that some of the external + + align:start position:0% +that tells me that some of the external + + + align:start position:0% +that tells me that some of the external +forces in the theta hat direction in + + align:start position:0% +forces in the theta hat direction in + + + align:start position:0% +forces in the theta hat direction in +this case is this unknown F but I know + + align:start position:0% +this case is this unknown F but I know + + + align:start position:0% +this case is this unknown F but I know +from Newton that that's got to be equal + + align:start position:0% +from Newton that that's got to be equal + + + align:start position:0% +from Newton that that's got to be equal +to the mass times acceleration in that + + align:start position:0% +to the mass times acceleration in that + + + align:start position:0% +to the mass times acceleration in that +direction but in this case then that is + + align:start position:0% +direction but in this case then that is + + + align:start position:0% +direction but in this case then that is +2m r dot theta dot theta hat okay so + + align:start position:0% +2m r dot theta dot theta hat okay so + + + align:start position:0% +2m r dot theta dot theta hat okay so +there must that got this right district + + align:start position:0% +there must that got this right district + + + align:start position:0% +there must that got this right district +way ssin and applying Newton's second + + align:start position:0% +way ssin and applying Newton's second + + + align:start position:0% +way ssin and applying Newton's second +law I can find out what that force must + + align:start position:0% +law I can find out what that force must + + + align:start position:0% +law I can find out what that force must +be then it would have been a lot more + + align:start position:0% +be then it would have been a lot more + + + align:start position:0% +be then it would have been a lot more +work if I had drawn it in some arbitrary + + align:start position:0% +work if I had drawn it in some arbitrary + + + align:start position:0% +work if I had drawn it in some arbitrary +in-between direction because then I'd + + align:start position:0% +in-between direction because then I'd + + + align:start position:0% +in-between direction because then I'd +have to break it down into its + + align:start position:0% +have to break it down into its + + + align:start position:0% +have to break it down into its +components to write this so I've done it + + align:start position:0% +components to write this so I've done it + + + align:start position:0% +components to write this so I've done it +made it as easy as possible for myself + + align:start position:0% +made it as easy as possible for myself + + + align:start position:0% +made it as easy as possible for myself +so there's a force like this and there + + align:start position:0% +so there's a force like this and there + + + align:start position:0% +so there's a force like this and there +is another force like that this one week + + align:start position:0% +is another force like that this one week + + + align:start position:0% +is another force like that this one week +is + + align:start position:0% +is + + + align:start position:0% +is +was caused by the centripetal + + align:start position:0% +was caused by the centripetal + + + align:start position:0% +was caused by the centripetal +acceleration or this force causes the + + align:start position:0% +acceleration or this force causes the + + + align:start position:0% +acceleration or this force causes the +centripetal acceleration in order to + + align:start position:0% +centripetal acceleration in order to + + + align:start position:0% +centripetal acceleration in order to +make something go in a circular path you + + align:start position:0% +make something go in a circular path you + + + align:start position:0% +make something go in a circular path you +have to exert a force on it that's the + + align:start position:0% +have to exert a force on it that's the + + + align:start position:0% +have to exert a force on it that's the +force and in order to accelerate + + align:start position:0% +force and in order to accelerate + + + align:start position:0% +force and in order to accelerate +something angular ly you have to apply a + + align:start position:0% +something angular ly you have to apply a + + + align:start position:0% +something angular ly you have to apply a +force that comes from the euler term and + + align:start position:0% +force that comes from the euler term and + + + align:start position:0% +force that comes from the euler term and +this is the curious term this is the + + align:start position:0% +this is the curious term this is the + + + align:start position:0% +this is the curious term this is the +Coriolis term and that's so where does + + align:start position:0% +Coriolis term and that's so where does + + + align:start position:0% +Coriolis term and that's so where does +it come from you know that's the it's a + + align:start position:0% +it come from you know that's the it's a + + + align:start position:0% +it come from you know that's the it's a +that's that's the crux of the matter + + align:start position:0% +that's that's the crux of the matter + + + align:start position:0% +that's that's the crux of the matter +here where does it come from so part of + + align:start position:0% +here where does it come from so part of + + + align:start position:0% +here where does it come from so part of +the reading that you need to do now is + + align:start position:0% +the reading that you need to do now is + + + align:start position:0% +the reading that you need to do now is +chapter 15 chapter 15 most of it is + + align:start position:0% +chapter 15 chapter 15 most of it is + + + align:start position:0% +chapter 15 chapter 15 most of it is +going to be to complete review it just + + align:start position:0% +going to be to complete review it just + + + align:start position:0% +going to be to complete review it just +says the conservation of a linear + + align:start position:0% +says the conservation of a linear + + + align:start position:0% +says the conservation of a linear +momentum impulse and momentum but it + + align:start position:0% +momentum impulse and momentum but it + + + align:start position:0% +momentum impulse and momentum but it +also gets into angular momentum so we're + + align:start position:0% +also gets into angular momentum so we're + + + align:start position:0% +also gets into angular momentum so we're +going to talk quite a lot about angular + + align:start position:0% +going to talk quite a lot about angular + + + align:start position:0% +going to talk quite a lot about angular +momentum but and I want to do very brief + + align:start position:0% +momentum but and I want to do very brief + + + align:start position:0% +momentum but and I want to do very brief +little review right now + + align:start position:0% + + + + align:start position:0% + +that it so that it applies to this + + align:start position:0% +that it so that it applies to this + + + align:start position:0% +that it so that it applies to this +problem so we've come up with an + + align:start position:0% +problem so we've come up with an + + + align:start position:0% +problem so we've come up with an +expression that the force in the theta + + align:start position:0% +expression that the force in the theta + + + align:start position:0% +expression that the force in the theta +Direction here comes there's got to be + + align:start position:0% +Direction here comes there's got to be + + + align:start position:0% +Direction here comes there's got to be +that 2m r dot theta dot so here's my + + align:start position:0% +that 2m r dot theta dot so here's my + + + align:start position:0% +that 2m r dot theta dot so here's my +point O and a for that matter but + + align:start position:0% +point O and a for that matter but + + + align:start position:0% +point O and a for that matter but +looking down on our problem here's my + + align:start position:0% +looking down on our problem here's my + + + align:start position:0% +looking down on our problem here's my +mass some instant in time my rotation + + align:start position:0% +mass some instant in time my rotation + + + align:start position:0% +mass some instant in time my rotation +rate is theta dot work actually colic + + align:start position:0% +rate is theta dot work actually colic + + + align:start position:0% +rate is theta dot work actually colic +it's constant so it's K hat like that + + align:start position:0% +it's constant so it's K hat like that + + + align:start position:0% +it's constant so it's K hat like that +Kappa Omega K hat this is my R hat + + align:start position:0% +Kappa Omega K hat this is my R hat + + + align:start position:0% +Kappa Omega K hat this is my R hat +direction theta hat now this is I'm + + align:start position:0% +direction theta hat now this is I'm + + + align:start position:0% +direction theta hat now this is I'm +going to treat this as a particle not + + align:start position:0% +going to treat this as a particle not + + + align:start position:0% +going to treat this as a particle not +long we're going to be talking about the + + align:start position:0% +long we're going to be talking about the + + + align:start position:0% +long we're going to be talking about the +dynamics of rigid bodies we're just + + align:start position:0% +dynamics of rigid bodies we're just + + + align:start position:0% +dynamics of rigid bodies we're just +doing particles for the moment we think + + align:start position:0% +doing particles for the moment we think + + + align:start position:0% +doing particles for the moment we think +of them just as point masses and don't + + align:start position:0% +of them just as point masses and don't + + + align:start position:0% +of them just as point masses and don't +deal with their with their finite extent + + align:start position:0% +deal with their with their finite extent + + + align:start position:0% +deal with their with their finite extent +so we're still thinking of this as a + + align:start position:0% +so we're still thinking of this as a + + + align:start position:0% +so we're still thinking of this as a +particle and I'm going to write down the + + align:start position:0% +particle and I'm going to write down the + + + align:start position:0% +particle and I'm going to write down the +definition of the angular momentum of a + + align:start position:0% +definition of the angular momentum of a + + + align:start position:0% +definition of the angular momentum of a +particle this is be out here with + + align:start position:0% +particle this is be out here with + + + align:start position:0% +particle this is be out here with +respect to my fixed frame here at O and + + align:start position:0% +respect to my fixed frame here at O and + + + align:start position:0% +respect to my fixed frame here at O and +I'm going to use a lowercase H to + + align:start position:0% +I'm going to use a lowercase H to + + + align:start position:0% +I'm going to use a lowercase H to +describe angular momentum of particles + + align:start position:0% +describe angular momentum of particles + + + align:start position:0% +describe angular momentum of particles +that I'll be using to use capital H to + + align:start position:0% +that I'll be using to use capital H to + + + align:start position:0% +that I'll be using to use capital H to +describe the angular momentum of rigid + + align:start position:0% +describe the angular momentum of rigid + + + align:start position:0% +describe the angular momentum of rigid +bodies so this is a particle definition + + align:start position:0% +bodies so this is a particle definition + + + align:start position:0% +bodies so this is a particle definition +of the angular momentum of a particle + + align:start position:0% +of the angular momentum of a particle + + + align:start position:0% +of the angular momentum of a particle +with respect to a fixed point what we're + + align:start position:0% +with respect to a fixed point what we're + + + align:start position:0% +with respect to a fixed point what we're +going to come back to that that'll turn + + align:start position:0% +going to come back to that that'll turn + + + align:start position:0% +going to come back to that that'll turn +out to have some significance the + + align:start position:0% +out to have some significance the + + + align:start position:0% +out to have some significance the +definition of this is it's our B oh the + + align:start position:0% +definition of this is it's our B oh the + + + align:start position:0% +definition of this is it's our B oh the +position vector cross with the linear + + align:start position:0% +position vector cross with the linear + + + align:start position:0% +position vector cross with the linear +momentum evaluated in the fixed frame so + + align:start position:0% +momentum evaluated in the fixed frame so + + + align:start position:0% +momentum evaluated in the fixed frame so +that's the definition of angular + + align:start position:0% +that's the definition of angular + + + align:start position:0% +that's the definition of angular +momentum which is you have linear + + align:start position:0% +momentum which is you have linear + + + align:start position:0% +momentum which is you have linear +momentum and it's the cross product with + + align:start position:0% +momentum and it's the cross product with + + + align:start position:0% +momentum and it's the cross product with +the position vector out to it so in this + + align:start position:0% +the position vector out to it so in this + + + align:start position:0% +the position vector out to it so in this +case the rbo is + + align:start position:0% +case the rbo is + + + align:start position:0% +case the rbo is +Capital are our hat this is well it's + + align:start position:0% +Capital are our hat this is well it's + + + align:start position:0% +Capital are our hat this is well it's +not it's not this various excuses I'm + + align:start position:0% +not it's not this various excuses I'm + + + align:start position:0% +not it's not this various excuses I'm +not going to use it better or not I + + align:start position:0% +not going to use it better or not I + + + align:start position:0% +not going to use it better or not I +don't want to this I use as a constant I + + align:start position:0% +don't want to this I use as a constant I + + + align:start position:0% +don't want to this I use as a constant I +better keep it as the variable pardon + + align:start position:0% +better keep it as the variable pardon + + + align:start position:0% +better keep it as the variable pardon +that so it's our whatever the local + + align:start position:0% +that so it's our whatever the local + + + align:start position:0% +that so it's our whatever the local +position is in the R hat direction + + align:start position:0% +position is in the R hat direction + + + align:start position:0% +position is in the R hat direction +crossed with the linear momentum + + align:start position:0% +crossed with the linear momentum + + + align:start position:0% +crossed with the linear momentum +what's the linear momentum of that + + align:start position:0% +what's the linear momentum of that + + + align:start position:0% +what's the linear momentum of that +particle mass times velocity what's the + + align:start position:0% +particle mass times velocity what's the + + + align:start position:0% +particle mass times velocity what's the +velocity theta dot where do we write it + + align:start position:0% +velocity theta dot where do we write it + + + align:start position:0% +velocity theta dot where do we write it +up here someplace + + align:start position:0% +up here someplace + + + align:start position:0% +up here someplace +are the total velocity is r dot R hat + + align:start position:0% + + + + align:start position:0% + +plus R theta dot theta hat right and we + + align:start position:0% +plus R theta dot theta hat right and we + + + align:start position:0% +plus R theta dot theta hat right and we +need a mass in here so mass times + + align:start position:0% +need a mass in here so mass times + + + align:start position:0% +need a mass in here so mass times +velocity would be the momentum and we + + align:start position:0% +velocity would be the momentum and we + + + align:start position:0% +velocity would be the momentum and we +need the cross products without our hat + + align:start position:0% +need the cross products without our hat + + + align:start position:0% +need the cross products without our hat +cross our hat you get nothing from that + + align:start position:0% +cross our hat you get nothing from that + + + align:start position:0% +cross our hat you get nothing from that +and our hat cross theta hat positive or + + align:start position:0% +and our hat cross theta hat positive or + + + align:start position:0% +and our hat cross theta hat positive or +negative positive K right so this + + align:start position:0% +negative positive K right so this + + + align:start position:0% +negative positive K right so this +becomes M R squared theta dot in the K + + align:start position:0% +becomes M R squared theta dot in the K + + + align:start position:0% +becomes M R squared theta dot in the K +hat direction + + align:start position:0% + + + + align:start position:0% + +and this is this one is a constant + + align:start position:0% +and this is this one is a constant + + + align:start position:0% +and this is this one is a constant +alright this is cap Omega okay so this + + align:start position:0% +alright this is cap Omega okay so this + + + align:start position:0% +alright this is cap Omega okay so this +is my angular momentum of my particle + + align:start position:0% +is my angular momentum of my particle + + + align:start position:0% +is my angular momentum of my particle +with respect to this fixed reference + + align:start position:0% +with respect to this fixed reference + + + align:start position:0% +with respect to this fixed reference +frame and so last one final step that + + align:start position:0% +frame and so last one final step that + + + align:start position:0% +frame and so last one final step that +you know from your previous physics is + + align:start position:0% +you know from your previous physics is + + + align:start position:0% +you know from your previous physics is +well house torque related to angular + + align:start position:0% +well house torque related to angular + + + align:start position:0% +well house torque related to angular +momentum take again what do you remember + + align:start position:0% +momentum take again what do you remember + + + align:start position:0% +momentum take again what do you remember +time derivative so D by DT of HBO here + + align:start position:0% +time derivative so D by DT of HBO here + + + align:start position:0% +time derivative so D by DT of HBO here +the time rate of change of this vector + + align:start position:0% +the time rate of change of this vector + + + align:start position:0% +the time rate of change of this vector +is the torque with respect to this point + + align:start position:0% +is the torque with respect to this point + + + align:start position:0% +is the torque with respect to this point +with respect to O so what are constants + + align:start position:0% +with respect to O so what are constants + + + align:start position:0% +with respect to O so what are constants +in this thing we don't have to deal with + + align:start position:0% +in this thing we don't have to deal with + + + align:start position:0% +in this thing we don't have to deal with +their derivatives K hat is it does the + + align:start position:0% +their derivatives K hat is it does the + + + align:start position:0% +their derivatives K hat is it does the +direction of the angular momentum change + + align:start position:0% +direction of the angular momentum change + + + align:start position:0% +direction of the angular momentum change +it's upwards the derivative of K the + + align:start position:0% +it's upwards the derivative of K the + + + align:start position:0% +it's upwards the derivative of K the +unit vector K does it change in this + + align:start position:0% +unit vector K does it change in this + + + align:start position:0% +unit vector K does it change in this +problem no so there's no time for it to + + align:start position:0% +problem no so there's no time for it to + + + align:start position:0% +problem no so there's no time for it to +zero it's times derivative is zero the M + + align:start position:0% +zero it's times derivative is zero the M + + + align:start position:0% +zero it's times derivative is zero the M +time derivative is zero the only thing + + align:start position:0% +time derivative is zero the only thing + + + align:start position:0% +time derivative is zero the only thing +you have to take derivative is r so to + + align:start position:0% +you have to take derivative is r so to + + + align:start position:0% +you have to take derivative is r so to +our r dot + + align:start position:0% + + + + align:start position:0% + +so the torque is 2m r r dot Kappa Omega + + align:start position:0% +so the torque is 2m r r dot Kappa Omega + + + align:start position:0% +so the torque is 2m r r dot Kappa Omega +and it's all in the K direction and that + + align:start position:0% +and it's all in the K direction and that + + + align:start position:0% +and it's all in the K direction and that +had better be our vo cross F torque + + align:start position:0% +had better be our vo cross F torque + + + align:start position:0% +had better be our vo cross F torque +comes as a force times the moment arm + + align:start position:0% +comes as a force times the moment arm + + + align:start position:0% +comes as a force times the moment arm +right and we computed here a force in + + align:start position:0% +right and we computed here a force in + + + align:start position:0% +right and we computed here a force in +the theta direction so what would give + + align:start position:0% +the theta direction so what would give + + + align:start position:0% +the theta direction so what would give +us a torque in the K direction at R + + align:start position:0% +us a torque in the K direction at R + + + align:start position:0% +us a torque in the K direction at R +cross theta R hat cross theta hat gives + + align:start position:0% +cross theta R hat cross theta hat gives + + + align:start position:0% +cross theta R hat cross theta hat gives +you a K right R cross and this force the + + align:start position:0% +you a K right R cross and this force the + + + align:start position:0% +you a K right R cross and this force the +part of the force we have two forces one + + align:start position:0% +part of the force we have two forces one + + + align:start position:0% +part of the force we have two forces one +in the r direction and one in the theta + + align:start position:0% +in the r direction and one in the theta + + + align:start position:0% +in the r direction and one in the theta +direction the cross product this term up + + align:start position:0% +direction the cross product this term up + + + align:start position:0% +direction the cross product this term up +here the t gives you nothing right + + align:start position:0% +here the t gives you nothing right + + + align:start position:0% +here the t gives you nothing right +across our hat across our hat so the + + align:start position:0% +across our hat across our hat so the + + + align:start position:0% +across our hat across our hat so the +only force that matters here is this + + align:start position:0% +only force that matters here is this + + + align:start position:0% +only force that matters here is this +Coriolis one okay and so that force is + + align:start position:0% +Coriolis one okay and so that force is + + + align:start position:0% +Coriolis one okay and so that force is +2m r dot theta dot and we have the R + + align:start position:0% +2m r dot theta dot and we have the R + + + align:start position:0% +2m r dot theta dot and we have the R +cross we know this comes out in the K + + align:start position:0% +cross we know this comes out in the K + + + align:start position:0% +cross we know this comes out in the K +direction and we get an R in here when + + align:start position:0% +direction and we get an R in here when + + + align:start position:0% +direction and we get an R in here when +we compute this product and this to me + + align:start position:0% +we compute this product and this to me + + + align:start position:0% +we compute this product and this to me +looks an awful lot like this except I + + align:start position:0% +looks an awful lot like this except I + + + align:start position:0% +looks an awful lot like this except I +missed an R squared how do I do that + + align:start position:0% + + + + align:start position:0% + +oh no it's not our squared it started + + align:start position:0% +oh no it's not our squared it started + + + align:start position:0% +oh no it's not our squared it started +off over here as the angular momentum + + align:start position:0% +off over here as the angular momentum + + + align:start position:0% +off over here as the angular momentum +has in our square it took the derivative + + align:start position:0% +has in our square it took the derivative + + + align:start position:0% +has in our square it took the derivative +it dropped down to two our our dot + + align:start position:0% +it dropped down to two our our dot + + + align:start position:0% +it dropped down to two our our dot +that's right + + align:start position:0% +that's right + + + align:start position:0% +that's right +so the Coriolis force what's it got to + + align:start position:0% +so the Coriolis force what's it got to + + + align:start position:0% +so the Coriolis force what's it got to +do with the angular momentum that's kind + + align:start position:0% +do with the angular momentum that's kind + + + align:start position:0% +do with the angular momentum that's kind +of the point of the exercise here in + + align:start position:0% +of the point of the exercise here in + + + align:start position:0% +of the point of the exercise here in +order for this ping-pong ball to excel + + align:start position:0% +order for this ping-pong ball to excel + + + align:start position:0% +order for this ping-pong ball to excel +to be accelerated it's as it goes slowly + + align:start position:0% +to be accelerated it's as it goes slowly + + + align:start position:0% +to be accelerated it's as it goes slowly +out this tube the angular momentum is + + align:start position:0% +out this tube the angular momentum is + + + align:start position:0% +out this tube the angular momentum is +increasing in order to change angular + + align:start position:0% +increasing in order to change angular + + + align:start position:0% +increasing in order to change angular +momentum with time you have to apply a + + align:start position:0% +momentum with time you have to apply a + + + align:start position:0% +momentum with time you have to apply a +torque the torque that you have to apply + + align:start position:0% +torque the torque that you have to apply + + + align:start position:0% +torque the torque that you have to apply +is 2m RR dot in the K direction and that + + align:start position:0% +is 2m RR dot in the K direction and that + + + align:start position:0% +is 2m RR dot in the K direction and that +is our cross the Coriolis force so the + + align:start position:0% +is our cross the Coriolis force so the + + + align:start position:0% +is our cross the Coriolis force so the +Coriolis force in this case is the force + + align:start position:0% +Coriolis force in this case is the force + + + align:start position:0% +Coriolis force in this case is the force +that's necessary to increase the angular + + align:start position:0% +that's necessary to increase the angular + + + align:start position:0% +that's necessary to increase the angular +one of the angular momentum system + + align:start position:0% +one of the angular momentum system + + + align:start position:0% +one of the angular momentum system +that's very often the reason that's + + align:start position:0% +that's very often the reason that's + + + align:start position:0% +that's very often the reason that's +where it what Coriolis force is about so + + align:start position:0% +where it what Coriolis force is about so + + + align:start position:0% +where it what Coriolis force is about so +when you shoot an artillery piece in on + + align:start position:0% +when you shoot an artillery piece in on + + + align:start position:0% +when you shoot an artillery piece in on +the earth + + align:start position:0% +the earth + + + align:start position:0% +the earth +you got the projectile going out there + + align:start position:0% +you got the projectile going out there + + + align:start position:0% +you got the projectile going out there +it has angular momentum with respect to + + align:start position:0% +it has angular momentum with respect to + + + align:start position:0% +it has angular momentum with respect to +the earth and you'll find out that this + + align:start position:0% +the earth and you'll find out that this + + + align:start position:0% +the earth and you'll find out that this +little term pops up and in fact the + + align:start position:0% +little term pops up and in fact the + + + align:start position:0% +little term pops up and in fact the +projectile doesn't go straight it curves + + align:start position:0% + + + + align:start position:0% + +there's lots of things that because of + + align:start position:0% +there's lots of things that because of + + + align:start position:0% +there's lots of things that because of +conservation of angular momentum you end + + align:start position:0% +conservation of angular momentum you end + + + align:start position:0% +conservation of angular momentum you end +up with this term popping up in this + + align:start position:0% +up with this term popping up in this + + + align:start position:0% +up with this term popping up in this +case angular momentum is not conserved + + align:start position:0% +case angular momentum is not conserved + + + align:start position:0% +case angular momentum is not conserved +it's increasing so you have this force + + align:start position:0% +it's increasing so you have this force + + + align:start position:0% +it's increasing so you have this force +to make it happen any questions about + + align:start position:0% +to make it happen any questions about + + + align:start position:0% +to make it happen any questions about +this we're going to see a lot you're + + align:start position:0% +this we're going to see a lot you're + + + align:start position:0% +this we're going to see a lot you're +going to use this one a lot you going to + + align:start position:0% +going to use this one a lot you going to + + + align:start position:0% +going to use this one a lot you going to +work with it a lot + + align:start position:0% + + + + align:start position:0% + +so anytime you see changes in angular + + align:start position:0% +so anytime you see changes in angular + + + align:start position:0% +so anytime you see changes in angular +momentum happening in a problem in these + + align:start position:0% +momentum happening in a problem in these + + + align:start position:0% +momentum happening in a problem in these +moat in these problems with circular + + align:start position:0% +moat in these problems with circular + + + align:start position:0% +moat in these problems with circular +motion velocities of parts increasing + + align:start position:0% +motion velocities of parts increasing + + + align:start position:0% +motion velocities of parts increasing +and radius you'll almost always see this + + align:start position:0% +and radius you'll almost always see this + + + align:start position:0% +and radius you'll almost always see this +term pop up anytime you see these + + align:start position:0% +term pop up anytime you see these + + + align:start position:0% +term pop up anytime you see these +changes in angular momentum you'll often + + align:start position:0% +changes in angular momentum you'll often + + + align:start position:0% +changes in angular momentum you'll often +see the Coriolis term + + align:start position:0% +see the Coriolis term + + + align:start position:0% +see the Coriolis term +all right now we're going to do a let's + + align:start position:0% +all right now we're going to do a let's + + + align:start position:0% +all right now we're going to do a let's +do a really another interesting problem + + align:start position:0% +do a really another interesting problem + + + align:start position:0% +do a really another interesting problem +simple but interesting and that is + + align:start position:0% +simple but interesting and that is + + + align:start position:0% +simple but interesting and that is +really to go let's go do this problem + + align:start position:0% +really to go let's go do this problem + + + align:start position:0% +really to go let's go do this problem +where the things really allowed to come + + align:start position:0% +where the things really allowed to come + + + align:start position:0% +where the things really allowed to come +freely out okay all right + + align:start position:0% +freely out okay all right + + + align:start position:0% +freely out okay all right +you're ready to fend yourselves + + align:start position:0% + + + + align:start position:0% + +all right a little short stick is pretty + + align:start position:0% +all right a little short stick is pretty + + + align:start position:0% +all right a little short stick is pretty +effective at throwing candy all right + + align:start position:0% +effective at throwing candy all right + + + align:start position:0% +effective at throwing candy all right +you got your safety glasses on you want + + align:start position:0% +you got your safety glasses on you want + + + align:start position:0% +you got your safety glasses on you want +me to see if I can get one up there also + + align:start position:0% +me to see if I can get one up there also + + + align:start position:0% +me to see if I can get one up there also +I obviously haven't practiced this right + + align:start position:0% + + + + align:start position:0% + +all right + + align:start position:0% +all right + + + align:start position:0% +all right +last one actually this just two more all + + align:start position:0% +last one actually this just two more all + + + align:start position:0% +last one actually this just two more all +right what makes this work all right + + align:start position:0% +right what makes this work all right + + + align:start position:0% +right what makes this work all right +let's do that let's do this problem + + align:start position:0% + + + + align:start position:0% + +sorry let's look at our candy shooter + + align:start position:0% + + + + align:start position:0% + +so I'm whipping this thing around + + align:start position:0% +so I'm whipping this thing around + + + align:start position:0% +so I'm whipping this thing around +candies coming out of here is it B again + + align:start position:0% +candies coming out of here is it B again + + + align:start position:0% +candies coming out of here is it B again +I got a nosy not mess with the Z part z + + align:start position:0% +I got a nosy not mess with the Z part z + + + align:start position:0% +I got a nosy not mess with the Z part z +part is trivial to usually deal with + + align:start position:0% +part is trivial to usually deal with + + + align:start position:0% +part is trivial to usually deal with +because it's totally independent just + + align:start position:0% +because it's totally independent just + + + align:start position:0% +because it's totally independent just +separate equations doesn't complicate + + align:start position:0% +separate equations doesn't complicate + + + align:start position:0% +separate equations doesn't complicate +things much at all even when you have Z + + align:start position:0% +things much at all even when you have Z + + + align:start position:0% +things much at all even when you have Z +now in this case the velocity and here's + + align:start position:0% +now in this case the velocity and here's + + + align:start position:0% +now in this case the velocity and here's +my old frame here the velocity of B with + + align:start position:0% +my old frame here the velocity of B with + + + align:start position:0% +my old frame here the velocity of B with +respect to O well now it's got boss I'm + + align:start position:0% +respect to O well now it's got boss I'm + + + align:start position:0% +respect to O well now it's got boss I'm +not going to move I'm standing still + + align:start position:0% +not going to move I'm standing still + + + align:start position:0% +not going to move I'm standing still +when I do it so the first term is zero + + align:start position:0% +when I do it so the first term is zero + + + align:start position:0% +when I do it so the first term is zero +it's got an R term r dot in the R hat + + align:start position:0% +it's got an R term r dot in the R hat + + + align:start position:0% +it's got an R term r dot in the R hat +direction and it has an R theta dot + + align:start position:0% +direction and it has an R theta dot + + + align:start position:0% +direction and it has an R theta dot +theta hat term okay and these can now + + align:start position:0% +theta hat term okay and these can now + + + align:start position:0% +theta hat term okay and these can now +this might be changing this might have a + + align:start position:0% +this might be changing this might have a + + + align:start position:0% +this might be changing this might have a +time derivative our double dot certainly + + align:start position:0% +time derivative our double dot certainly + + + align:start position:0% +time derivative our double dot certainly +does it's accelerating coming out of + + align:start position:0% +does it's accelerating coming out of + + + align:start position:0% +does it's accelerating coming out of +that tube and my theta angular motion it + + align:start position:0% +that tube and my theta angular motion it + + + align:start position:0% +that tube and my theta angular motion it +can be accelerating too so we're gonna + + align:start position:0% +can be accelerating too so we're gonna + + + align:start position:0% +can be accelerating too so we're gonna +have to deal with those I need to know + + align:start position:0% +have to deal with those I need to know + + + align:start position:0% +have to deal with those I need to know +the accelerations now having to + + align:start position:0% +the accelerations now having to + + + align:start position:0% +the accelerations now having to +emphasize it but it till now but it I + + align:start position:0% +emphasize it but it till now but it I + + + align:start position:0% +emphasize it but it till now but it I +find it conceptually useful too and when + + align:start position:0% +find it conceptually useful too and when + + + align:start position:0% +find it conceptually useful too and when +you work with polar coordinates you have + + align:start position:0% +you work with polar coordinates you have + + + align:start position:0% +you work with polar coordinates you have +this you can it you can have this + + align:start position:0% +this you can it you can have this + + + align:start position:0% +this you can it you can have this +ability to aggregate the terms in these + + align:start position:0% +ability to aggregate the terms in these + + + align:start position:0% +ability to aggregate the terms in these +two component directions so this you + + align:start position:0% +two component directions so this you + + + align:start position:0% +two component directions so this you +have this ball that our terms go + + align:start position:0% +have this ball that our terms go + + + align:start position:0% +have this ball that our terms go +together and we've left the Z double dot + + align:start position:0% +together and we've left the Z double dot + + + align:start position:0% +together and we've left the Z double dot +term it's just separate by itself drops + + align:start position:0% +term it's just separate by itself drops + + + align:start position:0% +term it's just separate by itself drops +out easily and you have the theta hat + + align:start position:0% +out easily and you have the theta hat + + + align:start position:0% +out easily and you have the theta hat +term and that's the R + + align:start position:0% + + + + align:start position:0% + +theta double dot plus 2 r dot theta dot + + align:start position:0% +theta double dot plus 2 r dot theta dot + + + align:start position:0% +theta double dot plus 2 r dot theta dot +and these are in the theta hat direction + + align:start position:0% +and these are in the theta hat direction + + + align:start position:0% +and these are in the theta hat direction +there's your Coriolis term your Euler + + align:start position:0% +there's your Coriolis term your Euler + + + align:start position:0% +there's your Coriolis term your Euler +acceleration term centripetal term yeah + + align:start position:0% + + + + align:start position:0% + +well I don't know if I ought to tell you + + align:start position:0% +well I don't know if I ought to tell you + + + align:start position:0% +well I don't know if I ought to tell you +secrets about me because it's going to + + align:start position:0% +secrets about me because it's going to + + + align:start position:0% +secrets about me because it's going to +give you an advantage on the quiz but I + + align:start position:0% +give you an advantage on the quiz but I + + + align:start position:0% +give you an advantage on the quiz but I +have almost never ever been known to ask + + align:start position:0% +have almost never ever been known to ask + + + align:start position:0% +have almost never ever been known to ask +a question that says derive ok but I'll + + align:start position:0% +a question that says derive ok but I'll + + + align:start position:0% +a question that says derive ok but I'll +sure ask you concept questions I really + + align:start position:0% +sure ask you concept questions I really + + + align:start position:0% +sure ask you concept questions I really +want you understand the principles I + + align:start position:0% +want you understand the principles I + + + align:start position:0% +want you understand the principles I +really need I'm not I don't get real + + align:start position:0% +really need I'm not I don't get real + + + align:start position:0% +really need I'm not I don't get real +hung up on a have you need a grungy + + align:start position:0% +hung up on a have you need a grungy + + + align:start position:0% +hung up on a have you need a grungy +grind-it-out + + align:start position:0% +grind-it-out + + + align:start position:0% +grind-it-out +things do I want you to remember the + + align:start position:0% +things do I want you to remember the + + + align:start position:0% +things do I want you to remember the +formula for how to take the derivative + + align:start position:0% +formula for how to take the derivative + + + align:start position:0% +formula for how to take the derivative +of a vector in rotating frame yeah + + align:start position:0% +of a vector in rotating frame yeah + + + align:start position:0% +of a vector in rotating frame yeah +that's what that that's where these have + + align:start position:0% +that's what that that's where these have + + + align:start position:0% +that's what that that's where these have +come from + + align:start position:0% + + + + align:start position:0% + +you had better remember this these two + + align:start position:0% +you had better remember this these two + + + align:start position:0% +you had better remember this these two +formulas the velocity formula and this + + align:start position:0% +formulas the velocity formula and this + + + align:start position:0% +formulas the velocity formula and this +and the acceleration format are just + + align:start position:0% +and the acceleration format are just + + + align:start position:0% +and the acceleration format are just +core to this course now the way quizzes + + align:start position:0% +core to this course now the way quizzes + + + align:start position:0% +core to this course now the way quizzes +are done first quiz you come in with one + + align:start position:0% +are done first quiz you come in with one + + + align:start position:0% +are done first quiz you come in with one +sheet of paper what would it better be + + align:start position:0% +sheet of paper what would it better be + + + align:start position:0% +sheet of paper what would it better be +on your paper ok and second quiz two + + align:start position:0% +on your paper ok and second quiz two + + + align:start position:0% +on your paper ok and second quiz two +sheets final three sheets that kind of + + align:start position:0% +sheets final three sheets that kind of + + + align:start position:0% +sheets final three sheets that kind of +thing ok conceptually you got forces in + + align:start position:0% +thing ok conceptually you got forces in + + + align:start position:0% +thing ok conceptually you got forces in +the armed forces in the Z forces in + + align:start position:0% +the armed forces in the Z forces in + + + align:start position:0% +the armed forces in the Z forces in +accelerations in R theta R theta and Z + + align:start position:0% +accelerations in R theta R theta and Z + + + align:start position:0% +accelerations in R theta R theta and Z +forces R theta and Z so here's here's + + align:start position:0% +forces R theta and Z so here's here's + + + align:start position:0% +forces R theta and Z so here's here's +here's the and for these planar motion + + align:start position:0% +here's the and for these planar motion + + + align:start position:0% +here's the and for these planar motion +problems this one's sure easy to use so + + align:start position:0% +problems this one's sure easy to use so + + + align:start position:0% +problems this one's sure easy to use so +let's think about this problem I'm going + + align:start position:0% +let's think about this problem I'm going + + + align:start position:0% +let's think about this problem I'm going +to let this be frictionless just to make + + align:start position:0% +to let this be frictionless just to make + + + align:start position:0% +to let this be frictionless just to make +it easy all right + + align:start position:0% +it easy all right + + + align:start position:0% +it easy all right +so what possible forces act on the + + align:start position:0% +so what possible forces act on the + + + align:start position:0% +so what possible forces act on the +punkah candy let's do a free body + + align:start position:0% +punkah candy let's do a free body + + + align:start position:0% +punkah candy let's do a free body +diagram of the chunk of candy coming out + + align:start position:0% +diagram of the chunk of candy coming out + + + align:start position:0% +diagram of the chunk of candy coming out +of here what are the forces in the let's + + align:start position:0% +of here what are the forces in the let's + + + align:start position:0% +of here what are the forces in the let's +keep it planar you know we can get + + align:start position:0% +keep it planar you know we can get + + + align:start position:0% +keep it planar you know we can get +gravity into this but I'm just let's + + align:start position:0% +gravity into this but I'm just let's + + + align:start position:0% +gravity into this but I'm just let's +just do it in a plane so I'm just going + + align:start position:0% +just do it in a plane so I'm just going + + + align:start position:0% +just do it in a plane so I'm just going +horizontal and slinging this thing + + align:start position:0% +horizontal and slinging this thing + + + align:start position:0% +horizontal and slinging this thing +gravity is in the Z 2 + + align:start position:0% +gravity is in the Z 2 + + + align:start position:0% +gravity is in the Z 2 +direction and I'm constrained it in the + + align:start position:0% +direction and I'm constrained it in the + + + align:start position:0% +direction and I'm constrained it in the +Z so not there must it's somebody + + align:start position:0% +Z so not there must it's somebody + + + align:start position:0% +Z so not there must it's somebody +something supporting the gravity and the + + align:start position:0% +something supporting the gravity and the + + + align:start position:0% +something supporting the gravity and the +tube so definitely there's an mg on this + + align:start position:0% +tube so definitely there's an mg on this + + + align:start position:0% +tube so definitely there's an mg on this +thing downwards but it's in the Z + + align:start position:0% +thing downwards but it's in the Z + + + align:start position:0% +thing downwards but it's in the Z +direction and we're just not we're not + + align:start position:0% +direction and we're just not we're not + + + align:start position:0% +direction and we're just not we're not +letting it move in the Z what about the + + align:start position:0% +letting it move in the Z what about the + + + align:start position:0% +letting it move in the Z what about the +horizontal distance R this is my R hat + + align:start position:0% +horizontal distance R this is my R hat + + + align:start position:0% +horizontal distance R this is my R hat +direction this is my theta hat direction + + align:start position:0% +direction this is my theta hat direction + + + align:start position:0% +direction this is my theta hat direction +whoops not either theta is going this + + align:start position:0% +whoops not either theta is going this + + + align:start position:0% +whoops not either theta is going this +way so I've drawn this as a side view + + align:start position:0% +way so I've drawn this as a side view + + + align:start position:0% +way so I've drawn this as a side view +what's the force in the R hat direction + + align:start position:0% + + + + align:start position:0% + +okay in order to do this problem you got + + align:start position:0% +okay in order to do this problem you got + + + align:start position:0% +okay in order to do this problem you got +to figure that out what are the forces + + align:start position:0% + + + + align:start position:0% + +what are the source of forces in the r + + align:start position:0% +what are the source of forces in the r + + + align:start position:0% +what are the source of forces in the r +direction + + align:start position:0% +direction + + + align:start position:0% +direction +here's your R direction say what mind + + align:start position:0% +here's your R direction say what mind + + + align:start position:0% +here's your R direction say what mind +you guys let me be yeah there are not + + align:start position:0% +you guys let me be yeah there are not + + + align:start position:0% +you guys let me be yeah there are not +any is that what you said aren't any and + + align:start position:0% +any is that what you said aren't any and + + + align:start position:0% +any is that what you said aren't any and +why is that right so there's no forces + + align:start position:0% +why is that right so there's no forces + + + align:start position:0% +why is that right so there's no forces +in the r direction so there's no forces + + align:start position:0% +in the r direction so there's no forces + + + align:start position:0% +in the r direction so there's no forces +on this thing in the r and if we this is + + align:start position:0% +on this thing in the r and if we this is + + + align:start position:0% +on this thing in the r and if we this is +so then this is a side view we could do + + align:start position:0% +so then this is a side view we could do + + + align:start position:0% +so then this is a side view we could do +the top view looking down top view you + + align:start position:0% +the top view looking down top view you + + + align:start position:0% +the top view looking down top view you +got your XY you also have your here's + + align:start position:0% +got your XY you also have your here's + + + align:start position:0% +got your XY you also have your here's +the thing here's the ball here's the r + + align:start position:0% +the thing here's the ball here's the r + + + align:start position:0% +the thing here's the ball here's the r +hat here's the theta hat now Freebody + + align:start position:0% +hat here's the theta hat now Freebody + + + align:start position:0% +hat here's the theta hat now Freebody +diagram in the top view well there's + + align:start position:0% +diagram in the top view well there's + + + align:start position:0% +diagram in the top view well there's +some force here probably + + align:start position:0% + + + + align:start position:0% + +ah absolutely she's commenting that we + + align:start position:0% +ah absolutely she's commenting that we + + + align:start position:0% +ah absolutely she's commenting that we +do have accelerations in the R hat + + align:start position:0% +do have accelerations in the R hat + + + align:start position:0% +do have accelerations in the R hat +direction right and no force so you're + + align:start position:0% +direction right and no force so you're + + + align:start position:0% +direction right and no force so you're +getting that's the conundrum of this + + align:start position:0% +getting that's the conundrum of this + + + align:start position:0% +getting that's the conundrum of this +problem that's the point of this problem + + align:start position:0% +problem that's the point of this problem + + + align:start position:0% +problem that's the point of this problem +so let me continue ok Freebody diagram + + align:start position:0% +so let me continue ok Freebody diagram + + + align:start position:0% +so let me continue ok Freebody diagram +so I'm allowing and looking down on it + + align:start position:0% +so I'm allowing and looking down on it + + + align:start position:0% +so I'm allowing and looking down on it +I'm lying for some force it's a normal + + align:start position:0% +I'm lying for some force it's a normal + + + align:start position:0% +I'm lying for some force it's a normal +force that comes from the pipe exerting + + align:start position:0% +force that comes from the pipe exerting + + + align:start position:0% +force that comes from the pipe exerting +the force on the candy and it since it's + + align:start position:0% +the force on the candy and it since it's + + + align:start position:0% +the force on the candy and it since it's +frictionless it can only be normal to + + align:start position:0% +frictionless it can only be normal to + + + align:start position:0% +frictionless it can only be normal to +the pipe ok so there's there's the free + + align:start position:0% +the pipe ok so there's there's the free + + + align:start position:0% +the pipe ok so there's there's the free +body diagram in the top view so we can + + align:start position:0% +body diagram in the top view so we can + + + align:start position:0% +body diagram in the top view so we can +write two equations we can write three + + align:start position:0% +write two equations we can write three + + + align:start position:0% +write two equations we can write three +equations this one equal to zero this + + align:start position:0% +equations this one equal to zero this + + + align:start position:0% +equations this one equal to zero this +one in the R hat direction this one in + + align:start position:0% +one in the R hat direction this one in + + + align:start position:0% +one in the R hat direction this one in +the theta hat direction + + align:start position:0% + + + + align:start position:0% + +some of the forces our hat direction + + align:start position:0% +some of the forces our hat direction + + + align:start position:0% +some of the forces our hat direction +must be zero and we have a mass we have + + align:start position:0% +must be zero and we have a mass we have + + + align:start position:0% +must be zero and we have a mass we have +an acceleration solve for R double dot + + align:start position:0% + + + + align:start position:0% + +remarkable there's no force in the R hat + + align:start position:0% +remarkable there's no force in the R hat + + + align:start position:0% +remarkable there's no force in the R hat +direction the the position of the object + + align:start position:0% +direction the the position of the object + + + align:start position:0% +direction the the position of the object +the R coordinate it has a velocity it + + align:start position:0% +the R coordinate it has a velocity it + + + align:start position:0% +the R coordinate it has a velocity it +has an acceleration but the total + + align:start position:0% +has an acceleration but the total + + + align:start position:0% +has an acceleration but the total +acceleration in the R hat Direction is + + align:start position:0% +acceleration in the R hat Direction is + + + align:start position:0% +acceleration in the R hat Direction is +actually zero the rate of change of the + + align:start position:0% +actually zero the rate of change of the + + + align:start position:0% +actually zero the rate of change of the +of the velocity of this thing in the + + align:start position:0% +of the velocity of this thing in the + + + align:start position:0% +of the velocity of this thing in the +radial direction R double dot is non + + align:start position:0% +radial direction R double dot is non + + + align:start position:0% +radial direction R double dot is non +zero but there are no forces on it I + + align:start position:0% + + + + align:start position:0% + +have pondered another way to explain + + align:start position:0% +have pondered another way to explain + + + align:start position:0% +have pondered another way to explain +this I'm still thinking about it + + align:start position:0% +this I'm still thinking about it + + + align:start position:0% +this I'm still thinking about it +and you think about this too how do you + + align:start position:0% +and you think about this too how do you + + + align:start position:0% +and you think about this too how do you +know how do you explain this in the + + align:start position:0% +know how do you explain this in the + + + align:start position:0% +know how do you explain this in the +absence of forces and it's kind of is + + align:start position:0% +absence of forces and it's kind of is + + + align:start position:0% +absence of forces and it's kind of is +partly where the concept comes from of + + align:start position:0% +partly where the concept comes from of + + + align:start position:0% +partly where the concept comes from of +fictitious forces that centrifugal force + + align:start position:0% +fictitious forces that centrifugal force + + + align:start position:0% +fictitious forces that centrifugal force +is a force it's not it's an acceleration + + align:start position:0% +is a force it's not it's an acceleration + + + align:start position:0% +is a force it's not it's an acceleration +this is just saying that let's go back + + align:start position:0% +this is just saying that let's go back + + + align:start position:0% +this is just saying that let's go back +to this problem in order to make + + align:start position:0% +to this problem in order to make + + + align:start position:0% +to this problem in order to make +something go in a circle you have you + + align:start position:0% +something go in a circle you have you + + + align:start position:0% +something go in a circle you have you +have to put a force on it to caused the + + align:start position:0% +have to put a force on it to caused the + + + align:start position:0% +have to put a force on it to caused the +centripetal acceleration you have to + + align:start position:0% +centripetal acceleration you have to + + + align:start position:0% +centripetal acceleration you have to +allow the thing to go out if you're not + + align:start position:0% +allow the thing to go out if you're not + + + align:start position:0% +allow the thing to go out if you're not +forcing it to go in a circle you have to + + align:start position:0% +forcing it to go in a circle you have to + + + align:start position:0% +forcing it to go in a circle you have to +allow it to go out at that rate in order + + align:start position:0% +allow it to go out at that rate in order + + + align:start position:0% +allow it to go out at that rate in order +for there to be no sand trip Atal + + align:start position:0% +for there to be no sand trip Atal + + + align:start position:0% +for there to be no sand trip Atal +accelerations on the object yeah + + align:start position:0% + + + + align:start position:0% + +in the y-direction to get it started + + align:start position:0% + + + + align:start position:0% + +does it experience and trip it'll + + align:start position:0% + + + + align:start position:0% + +acceleration so there's no rotation does + + align:start position:0% +acceleration so there's no rotation does + + + align:start position:0% +acceleration so there's no rotation does +it an experienced centripetal + + align:start position:0% +it an experienced centripetal + + + align:start position:0% +it an experienced centripetal +acceleration what do you think yeah okay + + align:start position:0% +acceleration what do you think yeah okay + + + align:start position:0% +acceleration what do you think yeah okay +it's because it goes through curved + + align:start position:0% +it's because it goes through curved + + + align:start position:0% +it's because it goes through curved +motion at any instant time when it's + + align:start position:0% +motion at any instant time when it's + + + align:start position:0% +motion at any instant time when it's +doing that there's a radius of curvature + + align:start position:0% +doing that there's a radius of curvature + + + align:start position:0% +doing that there's a radius of curvature +you can at that instant time think of it + + align:start position:0% +you can at that instant time think of it + + + align:start position:0% +you can at that instant time think of it +as being in a circular path okay and + + align:start position:0% +as being in a circular path okay and + + + align:start position:0% +as being in a circular path okay and +sometimes it's just really easy to do + + align:start position:0% +sometimes it's just really easy to do + + + align:start position:0% +sometimes it's just really easy to do +these kind of problems with normal and + + align:start position:0% +these kind of problems with normal and + + + align:start position:0% +these kind of problems with normal and +tangential coordinates so if I wanted + + align:start position:0% +tangential coordinates so if I wanted + + + align:start position:0% +tangential coordinates so if I wanted +I've got a I'm looking down on the XY + + align:start position:0% +I've got a I'm looking down on the XY + + + align:start position:0% +I've got a I'm looking down on the XY +plane + + align:start position:0% +plane + + + align:start position:0% +plane +gravity's into the earth so I'm looking + + align:start position:0% +gravity's into the earth so I'm looking + + + align:start position:0% +gravity's into the earth so I'm looking +down on a vehicle a car and that car + + align:start position:0% +down on a vehicle a car and that car + + + align:start position:0% +down on a vehicle a car and that car +guys kind of drunk he's going down the + + align:start position:0% +guys kind of drunk he's going down the + + + align:start position:0% +guys kind of drunk he's going down the +road like this okay so here's my Y + + align:start position:0% +road like this okay so here's my Y + + + align:start position:0% +road like this okay so here's my Y +here's my x and y equals some well a + + align:start position:0% +here's my x and y equals some well a + + + align:start position:0% +here's my x and y equals some well a +sine 2pi over the wavelength two PI over + + align:start position:0% +sine 2pi over the wavelength two PI over + + + align:start position:0% +sine 2pi over the wavelength two PI over +lambda times X and some a sine K X and + + align:start position:0% +lambda times X and some a sine K X and + + + align:start position:0% +lambda times X and some a sine K X and +as you drive down that I'm interview if + + align:start position:0% +as you drive down that I'm interview if + + + align:start position:0% +as you drive down that I'm interview if +you're in a car and you're doing that + + align:start position:0% +you're in a car and you're doing that + + + align:start position:0% +you're in a car and you're doing that +you get thrown side-to-side in the car + + align:start position:0% +you get thrown side-to-side in the car + + + align:start position:0% +you get thrown side-to-side in the car +right so you are being accelerated and + + align:start position:0% +right so you are being accelerated and + + + align:start position:0% +right so you are being accelerated and +so we want to be able to calculate the + + align:start position:0% +so we want to be able to calculate the + + + align:start position:0% +so we want to be able to calculate the +acceleration due to the fact that you're + + align:start position:0% +acceleration due to the fact that you're + + + align:start position:0% +acceleration due to the fact that you're +going down and doing a curved path and + + align:start position:0% +going down and doing a curved path and + + + align:start position:0% +going down and doing a curved path and +as we deal with these things with a + + align:start position:0% +as we deal with these things with a + + + align:start position:0% +as we deal with these things with a +sometimes with a convenient little set + + align:start position:0% +sometimes with a convenient little set + + + align:start position:0% +sometimes with a convenient little set +of coordinates that are our normal and + + align:start position:0% +of coordinates that are our normal and + + + align:start position:0% +of coordinates that are our normal and +tangential unit vectors you normal and + + align:start position:0% +tangential unit vectors you normal and + + + align:start position:0% +tangential unit vectors you normal and +you tangential at any instant in time + + align:start position:0% + + + + align:start position:0% + +and we know that in the so this is if + + align:start position:0% +and we know that in the so this is if + + + align:start position:0% +and we know that in the so this is if +this is along the path at any instant in + + align:start position:0% +this is along the path at any instant in + + + align:start position:0% +this is along the path at any instant in +time you're right here what direction is + + align:start position:0% +time you're right here what direction is + + + align:start position:0% +time you're right here what direction is +your velocity just definition of + + align:start position:0% +your velocity just definition of + + + align:start position:0% +your velocity just definition of +velocity tangent to the path right okay + + align:start position:0% +velocity tangent to the path right okay + + + align:start position:0% +velocity tangent to the path right okay +so a it's a time the velocity has got to + + align:start position:0% +so a it's a time the velocity has got to + + + align:start position:0% +so a it's a time the velocity has got to +be tangent to the path at that moment + + align:start position:0% +be tangent to the path at that moment + + + align:start position:0% +be tangent to the path at that moment +okay so velocity has some the vector has + + align:start position:0% +okay so velocity has some the vector has + + + align:start position:0% +okay so velocity has some the vector has +a magnitude and a unit vector u T here + + align:start position:0% +a magnitude and a unit vector u T here + + + align:start position:0% +a magnitude and a unit vector u T here +alcoholic tangent dollar to it and the + + align:start position:0% +alcoholic tangent dollar to it and the + + + align:start position:0% +alcoholic tangent dollar to it and the +acceleration of this thing is your time + + align:start position:0% +acceleration of this thing is your time + + + align:start position:0% +acceleration of this thing is your time +derivative of this and that's going to + + align:start position:0% +derivative of this and that's going to + + + align:start position:0% +derivative of this and that's going to +give you a V dot u t hat plus AV and now + + align:start position:0% +give you a V dot u t hat plus AV and now + + + align:start position:0% +give you a V dot u t hat plus AV and now +you need a time derivative of this guy + + align:start position:0% +you need a time derivative of this guy + + + align:start position:0% +you need a time derivative of this guy +but this is a unit length vector you can + + align:start position:0% +but this is a unit length vector you can + + + align:start position:0% +but this is a unit length vector you can +plug it into that equation for the + + align:start position:0% +plug it into that equation for the + + + align:start position:0% +plug it into that equation for the +derivative of a rotating vector and + + align:start position:0% +derivative of a rotating vector and + + + align:start position:0% +derivative of a rotating vector and +calculate what this should be you could + + align:start position:0% +calculate what this should be you could + + + align:start position:0% +calculate what this should be you could +also just draw it out now so I'll draw + + align:start position:0% +also just draw it out now so I'll draw + + + align:start position:0% +also just draw it out now so I'll draw +this for you + + align:start position:0% + + + + align:start position:0% + +how many do at a time I'll just be able + + align:start position:0% +how many do at a time I'll just be able + + + align:start position:0% +how many do at a time I'll just be able +to finish this + + align:start position:0% + + + + align:start position:0% + +here's my unit vector in the tangential + + align:start position:0% +here's my unit vector in the tangential + + + align:start position:0% +here's my unit vector in the tangential +direction as I'm going around this curve + + align:start position:0% + + + + align:start position:0% + +this is my tangential direction there at + + align:start position:0% +this is my tangential direction there at + + + align:start position:0% +this is my tangential direction there at +that it there's some incident I have a + + align:start position:0% +that it there's some incident I have a + + + align:start position:0% +that it there's some incident I have a +radius we call that row and in the + + align:start position:0% +radius we call that row and in the + + + align:start position:0% +radius we call that row and in the +little time delta T I go through an + + align:start position:0% +little time delta T I go through an + + + align:start position:0% +little time delta T I go through an +angle Delta Theta in delta T and this is + + align:start position:0% +angle Delta Theta in delta T and this is + + + align:start position:0% +angle Delta Theta in delta T and this is +my UT vector here it changes by a little + + align:start position:0% +my UT vector here it changes by a little + + + align:start position:0% +my UT vector here it changes by a little +bit that's the change in the UT unit + + align:start position:0% +bit that's the change in the UT unit + + + align:start position:0% +bit that's the change in the UT unit +vector in this time delta T and it goes + + align:start position:0% +vector in this time delta T and it goes + + + align:start position:0% +vector in this time delta T and it goes +perpendicular and it goes in the + + align:start position:0% +perpendicular and it goes in the + + + align:start position:0% +perpendicular and it goes in the +positive u in direction so Delta the + + align:start position:0% +positive u in direction so Delta the + + + align:start position:0% +positive u in direction so Delta the +easiest way to write this one Delta u T + + align:start position:0% +easiest way to write this one Delta u T + + + align:start position:0% +easiest way to write this one Delta u T +equals some theta dot delta T that's the + + align:start position:0% +equals some theta dot delta T that's the + + + align:start position:0% +equals some theta dot delta T that's the +angle times the times the length of the + + align:start position:0% +angle times the times the length of the + + + align:start position:0% +angle times the times the length of the +unit vector 1 that's the distance it + + align:start position:0% +unit vector 1 that's the distance it + + + align:start position:0% +unit vector 1 that's the distance it +goes so one so R Omega 1 theta dot is + + align:start position:0% +goes so one so R Omega 1 theta dot is + + + align:start position:0% +goes so one so R Omega 1 theta dot is +the distance that this unit vector goes + + align:start position:0% +the distance that this unit vector goes + + + align:start position:0% +the distance that this unit vector goes +through in delta T and the direction it + + align:start position:0% +through in delta T and the direction it + + + align:start position:0% +through in delta T and the direction it +goes in is u normal hat so Delta u T + + align:start position:0% +goes in is u normal hat so Delta u T + + + align:start position:0% +goes in is u normal hat so Delta u T +over delta T limit as T goes to zero you + + align:start position:0% +over delta T limit as T goes to zero you + + + align:start position:0% +over delta T limit as T goes to zero you +get theta dot u and just like before so + + align:start position:0% +get theta dot u and just like before so + + + align:start position:0% +get theta dot u and just like before so +the time derivative of this unit vector + + align:start position:0% +the time derivative of this unit vector + + + align:start position:0% +the time derivative of this unit vector +in the tangential direction is just + + align:start position:0% +in the tangential direction is just + + + align:start position:0% +in the tangential direction is just +stated dot time in the normal direction + + align:start position:0% +stated dot time in the normal direction + + + align:start position:0% +stated dot time in the normal direction +and then from that we can + + align:start position:0% +and then from that we can + + + align:start position:0% +and then from that we can +very quickly derive the rest of this + + align:start position:0% +very quickly derive the rest of this + + + align:start position:0% +very quickly derive the rest of this +acceleration the acceleration that is + + align:start position:0% +acceleration the acceleration that is + + + align:start position:0% +acceleration the acceleration that is +that Plus this we now know an expression + + align:start position:0% +that Plus this we now know an expression + + + align:start position:0% +that Plus this we now know an expression +for this is my U T dot term and plug + + align:start position:0% +for this is my U T dot term and plug + + + align:start position:0% +for this is my U T dot term and plug +that in here this then we need an + + align:start position:0% +that in here this then we need an + + + align:start position:0% +that in here this then we need an +expression for V what's the V well if + + align:start position:0% +expression for V what's the V well if + + + align:start position:0% +expression for V what's the V well if +that instant time it has some radius Rho + + align:start position:0% +that instant time it has some radius Rho + + + align:start position:0% +that instant time it has some radius Rho +it has an angular velocity theta dot so + + align:start position:0% +it has an angular velocity theta dot so + + + align:start position:0% +it has an angular velocity theta dot so +Rho theta dot would be the B here so I'm + + align:start position:0% +Rho theta dot would be the B here so I'm + + + align:start position:0% +Rho theta dot would be the B here so I'm +looking for an expression for V u T dot + + align:start position:0% + + + + align:start position:0% + +so that's V theta dot e UN but theta dot + + align:start position:0% +so that's V theta dot e UN but theta dot + + + align:start position:0% +so that's V theta dot e UN but theta dot +is V over Rho V squared sorry about this + + align:start position:0% +is V over Rho V squared sorry about this + + + align:start position:0% +is V over Rho V squared sorry about this +over Rho u n so this guy up here this is + + align:start position:0% +over Rho u n so this guy up here this is + + + align:start position:0% +over Rho u n so this guy up here this is +V dot u T plus V squared I'll rewrite it + + align:start position:0% +V dot u T plus V squared I'll rewrite it + + + align:start position:0% +V dot u T plus V squared I'll rewrite it +over Rho u n so if you're speeding up if + + align:start position:0% +over Rho u n so if you're speeding up if + + + align:start position:0% +over Rho u n so if you're speeding up if +you're going from 30 miles an hour to 40 + + align:start position:0% +you're going from 30 miles an hour to 40 + + + align:start position:0% +you're going from 30 miles an hour to 40 +miles an hour + + align:start position:0% +miles an hour + + + align:start position:0% +miles an hour +that's your tangential that's your P + + align:start position:0% +that's your tangential that's your P + + + align:start position:0% +that's your tangential that's your P +speed along the path that's this term + + align:start position:0% +speed along the path that's this term + + + align:start position:0% +speed along the path that's this term +but because you're going around the + + align:start position:0% +but because you're going around the + + + align:start position:0% +but because you're going around the +curve you have an acceleration B squared + + align:start position:0% +curve you have an acceleration B squared + + + align:start position:0% +curve you have an acceleration B squared +over Rho when you've run this into this + + align:start position:0% +over Rho when you've run this into this + + + align:start position:0% +over Rho when you've run this into this +before in physics this is where it comes + + align:start position:0% +before in physics this is where it comes + + + align:start position:0% +before in physics this is where it comes +from okay this is a centripetal + + align:start position:0% +from okay this is a centripetal + + + align:start position:0% +from okay this is a centripetal +acceleration like term if you replace V + + align:start position:0% +acceleration like term if you replace V + + + align:start position:0% +acceleration like term if you replace V +with Rho theta dot you'd get R theta dot + + align:start position:0% +with Rho theta dot you'd get R theta dot + + + align:start position:0% +with Rho theta dot you'd get R theta dot +squared so you can either put it in + + align:start position:0% +squared so you can either put it in + + + align:start position:0% +squared so you can either put it in +terms of V squared of a row or you can + + align:start position:0% +terms of V squared of a row or you can + + + align:start position:0% +terms of V squared of a row or you can +put it into in terms of Rho theta dot + + align:start position:0% +put it into in terms of Rho theta dot + + + align:start position:0% +put it into in terms of Rho theta dot +squared and Rho theta dot squared sounds + + align:start position:0% +squared and Rho theta dot squared sounds + + + align:start position:0% +squared and Rho theta dot squared sounds +a lot like my acceleration term right + + align:start position:0% +a lot like my acceleration term right + + + align:start position:0% +a lot like my acceleration term right +here okay + + align:start position:0% +here okay + + + align:start position:0% +here okay +so with that simple little formula you + + align:start position:0% +so with that simple little formula you + + + align:start position:0% +so with that simple little formula you +can do you need one other thing and you + + align:start position:0% +can do you need one other thing and you + + + align:start position:0% +can do you need one other thing and you +need to and you just go look it up in + + align:start position:0% +need to and you just go look it up in + + + align:start position:0% +need to and you just go look it up in +the book there is an expression from + + align:start position:0% +the book there is an expression from + + + align:start position:0% +the book there is an expression from +calculus for the radius of curvature of + + align:start position:0% +calculus for the radius of curvature of + + + align:start position:0% +calculus for the radius of curvature of +a path right and it has things it has + + align:start position:0% +a path right and it has things it has + + + align:start position:0% +a path right and it has things it has +first and second derivatives of Y with + + align:start position:0% +first and second derivatives of Y with + + + align:start position:0% +first and second derivatives of Y with +respect to X so you need a dy/dx and a + + align:start position:0% +respect to X so you need a dy/dx and a + + + align:start position:0% +respect to X so you need a dy/dx and a +d2y DX squared from a sine function you + + align:start position:0% +d2y DX squared from a sine function you + + + align:start position:0% +d2y DX squared from a sine function you +can calculate that so you calculate Rho + + align:start position:0% +can calculate that so you calculate Rho + + + align:start position:0% +can calculate that so you calculate Rho +from this from the formula that's in the + + align:start position:0% +from this from the formula that's in the + + + align:start position:0% +from this from the formula that's in the +book for calculating radius of curvature + + align:start position:0% +book for calculating radius of curvature + + + align:start position:0% +book for calculating radius of curvature +and you're done all right so see you on + + align:start position:0% +and you're done all right so see you on + + + align:start position:0% +and you're done all right so see you on +Thursday \ No newline at end of file diff --git a/itWklzE8MP0.txt b/itWklzE8MP0.txt new file mode 100644 index 0000000000000000000000000000000000000000..f1c87eeb026b02a50e76858807a8d8fda0186016 --- /dev/null +++ b/itWklzE8MP0.txt @@ -0,0 +1,2947 @@ +align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +the + + align:start position:0% +the + + + align:start position:0% +the +graphical view here is + + align:start position:0% +graphical view here is + + + align:start position:0% +graphical view here is +addresses the question of what is the + + align:start position:0% +addresses the question of what is the + + + align:start position:0% +addresses the question of what is the +right size of your initial project + + align:start position:0% +right size of your initial project + + + align:start position:0% +right size of your initial project +and so i have + + align:start position:0% +and so i have + + + align:start position:0% +and so i have +four curves here depending upon the + + align:start position:0% +four curves here depending upon the + + + align:start position:0% +four curves here depending upon the +alpha the alpha equals ones indicate + + align:start position:0% +alpha the alpha equals ones indicate + + + align:start position:0% +alpha the alpha equals ones indicate +that there's no economies of scale + + align:start position:0% +that there's no economies of scale + + + align:start position:0% +that there's no economies of scale +and as we go + + align:start position:0% +and as we go + + + align:start position:0% +and as we go +lower alpha means that there's lower + + align:start position:0% +lower alpha means that there's lower + + + align:start position:0% +lower alpha means that there's lower +exponent on the economy of the scale + + align:start position:0% +exponent on the economy of the scale + + + align:start position:0% +exponent on the economy of the scale +which means they're greater you get to a + + align:start position:0% +which means they're greater you get to a + + + align:start position:0% +which means they're greater you get to a +different design and as an extension of + + align:start position:0% +different design and as an extension of + + + align:start position:0% +different design and as an extension of +the garage case you see that the optimal + + align:start position:0% +the garage case you see that the optimal + + + align:start position:0% +the garage case you see that the optimal +design here is + + align:start position:0% +design here is + + + align:start position:0% +design here is +increases along with economies of scale + + align:start position:0% +increases along with economies of scale + + + align:start position:0% +increases along with economies of scale +and + + align:start position:0% +and + + + align:start position:0% +and +there are certain fixed costs so that + + align:start position:0% +there are certain fixed costs so that + + + align:start position:0% +there are certain fixed costs so that +the 25 units a day + + align:start position:0% +the 25 units a day + + + align:start position:0% +the 25 units a day +tons per day didn't seem like the best + + align:start position:0% +tons per day didn't seem like the best + + + align:start position:0% +tons per day didn't seem like the best +solution + + align:start position:0% +solution + + + align:start position:0% +solution +and + + align:start position:0% +and + + + align:start position:0% +and +uh so 50 seemed to be the right one + + align:start position:0% +uh so 50 seemed to be the right one + + + align:start position:0% +uh so 50 seemed to be the right one +given the fixed costs and everything + + align:start position:0% +given the fixed costs and everything + + + align:start position:0% +given the fixed costs and everything +else + + align:start position:0% +else + + + align:start position:0% +else +so all this is fairly straightforward uh + + align:start position:0% +so all this is fairly straightforward uh + + + align:start position:0% +so all this is fairly straightforward uh +from the garage case + + align:start position:0% +from the garage case + + + align:start position:0% +from the garage case +so + + align:start position:0% +so + + + align:start position:0% +so +um + + align:start position:0% +um + + + align:start position:0% +um +there is a + + align:start position:0% +there is a + + + align:start position:0% +there is a +general lesson here that is we might + + align:start position:0% +general lesson here that is we might + + + align:start position:0% +general lesson here that is we might +digest them is there's a trade-off + + align:start position:0% +digest them is there's a trade-off + + + align:start position:0% +digest them is there's a trade-off +between the economy the scale and the + + align:start position:0% +between the economy the scale and the + + + align:start position:0% +between the economy the scale and the +plant size when anticipating future + + align:start position:0% +plant size when anticipating future + + + align:start position:0% +plant size when anticipating future +growth + + align:start position:0% +growth + + + align:start position:0% +growth +this was not part of the mytex uh + + align:start position:0% +this was not part of the mytex uh + + + align:start position:0% +this was not part of the mytex uh +simple-minded + + align:start position:0% +simple-minded + + + align:start position:0% +simple-minded +homework assignment but + + align:start position:0% +homework assignment but + + + align:start position:0% +homework assignment but +it is the kind of thing that you think + + align:start position:0% +it is the kind of thing that you think + + + align:start position:0% +it is the kind of thing that you think +about and in this particular case the + + align:start position:0% +about and in this particular case the + + + align:start position:0% +about and in this particular case the +economy the scale and the example + + align:start position:0% +economy the scale and the example + + + align:start position:0% +economy the scale and the example +problem weren't very large so that + + align:start position:0% +problem weren't very large so that + + + align:start position:0% +problem weren't very large so that +building over + + align:start position:0% +building over + + + align:start position:0% +building over +uh as large as you could over that time + + align:start position:0% +uh as large as you could over that time + + + align:start position:0% +uh as large as you could over that time +was not very good um + + align:start position:0% +was not very good um + + + align:start position:0% +was not very good um +not obviously to be a good example + + align:start position:0% +not obviously to be a good example + + + align:start position:0% +not obviously to be a good example +now + + align:start position:0% +now + + + align:start position:0% +now +here is i think a really interesting + + align:start position:0% +here is i think a really interesting + + + align:start position:0% +here is i think a really interesting +table that is uh we're now looking at + + align:start position:0% +table that is uh we're now looking at + + + align:start position:0% +table that is uh we're now looking at +the + + align:start position:0% +the + + + align:start position:0% +the +uncertainty + + align:start position:0% +uncertainty + + + align:start position:0% +uncertainty +so + + align:start position:0% +so + + + align:start position:0% +so +uh + + align:start position:0% +uh + + + align:start position:0% +uh +as shown in this graph here there is uh + + align:start position:0% +as shown in this graph here there is uh + + + align:start position:0% +as shown in this graph here there is uh +the projection that is that the + + align:start position:0% +the projection that is that the + + + align:start position:0% +the projection that is that the +kepler offshore marine was going for + + align:start position:0% +kepler offshore marine was going for + + + align:start position:0% +kepler offshore marine was going for +which had been used which was it was + + align:start position:0% +which had been used which was it was + + + align:start position:0% +which had been used which was it was +growing + + align:start position:0% +growing + + + align:start position:0% +growing +the red line has sort of disappeared + + align:start position:0% +the red line has sort of disappeared + + + align:start position:0% +the red line has sort of disappeared +here but it's here and then leveling off + + align:start position:0% +here but it's here and then leveling off + + + align:start position:0% +here but it's here and then leveling off +over time over this 20 years and we + + align:start position:0% +over time over this 20 years and we + + + align:start position:0% +over time over this 20 years and we +had applied a deterministic + + align:start position:0% +had applied a deterministic + + + align:start position:0% +had applied a deterministic +um + + align:start position:0% +um + + + align:start position:0% +um +a uncertainty parameters to have it vary + + align:start position:0% +a uncertainty parameters to have it vary + + + align:start position:0% +a uncertainty parameters to have it vary +around here and of course we don't we + + align:start position:0% +around here and of course we don't we + + + align:start position:0% +around here and of course we don't we +had no + + align:start position:0% +had no + + + align:start position:0% +had no +special bases on it but recognize those + + align:start position:0% +special bases on it but recognize those + + + align:start position:0% +special bases on it but recognize those +uncertainty and it wasn't trivial so + + align:start position:0% +uncertainty and it wasn't trivial so + + + align:start position:0% +uncertainty and it wasn't trivial so +here's the ones we're working with now + + align:start position:0% +here's the ones we're working with now + + + align:start position:0% +here's the ones we're working with now +uh here's where we have the parametric + + align:start position:0% +uh here's where we have the parametric + + + align:start position:0% +uh here's where we have the parametric +analysis so + + align:start position:0% +analysis so + + + align:start position:0% +analysis so +um + + align:start position:0% +um + + + align:start position:0% +um +clearly + + align:start position:0% +clearly + + + align:start position:0% +clearly +uh the design depends upon the economy + + align:start position:0% +uh the design depends upon the economy + + + align:start position:0% +uh the design depends upon the economy +of the scale so + + align:start position:0% +of the scale so + + + align:start position:0% +of the scale so +uh here is the four that we were looking + + align:start position:0% +uh here is the four that we were looking + + + align:start position:0% +uh here is the four that we were looking +at + + align:start position:0% +at + + + align:start position:0% +at +from none to about the most except that + + align:start position:0% +from none to about the most except that + + + align:start position:0% +from none to about the most except that +i've seen in practice but + + align:start position:0% +i've seen in practice but + + + align:start position:0% +i've seen in practice but +seem to be appropriate as the range + + align:start position:0% +seem to be appropriate as the range + + + align:start position:0% +seem to be appropriate as the range +and if we look at the optimal capacity + + align:start position:0% +and if we look at the optimal capacity + + + align:start position:0% +and if we look at the optimal capacity +in terms of tons per day + + align:start position:0% +in terms of tons per day + + + align:start position:0% +in terms of tons per day +as i just showed you with the graph + + align:start position:0% +as i just showed you with the graph + + + align:start position:0% +as i just showed you with the graph +uh + + align:start position:0% +uh + + + align:start position:0% +uh +the more on economies of scale the + + align:start position:0% +the more on economies of scale the + + + align:start position:0% +the more on economies of scale the +larger is the the better design from the + + align:start position:0% +larger is the the better design from the + + + align:start position:0% +larger is the the better design from the +economic point of view + + align:start position:0% +economic point of view + + + align:start position:0% +economic point of view +the moment you impose uncertainty + + align:start position:0% +the moment you impose uncertainty + + + align:start position:0% +the moment you impose uncertainty +very similar to the garage case the + + align:start position:0% +very similar to the garage case the + + + align:start position:0% +very similar to the garage case the +optimal design shifts + + align:start position:0% +optimal design shifts + + + align:start position:0% +optimal design shifts +because you find out that well you build + + align:start position:0% +because you find out that well you build + + + align:start position:0% +because you find out that well you build +something too large for the demand and + + align:start position:0% +something too large for the demand and + + + align:start position:0% +something too large for the demand and +you lost and on the other hand if the + + align:start position:0% +you lost and on the other hand if the + + + align:start position:0% +you lost and on the other hand if the +demand was higher you didn't + + align:start position:0% +demand was higher you didn't + + + align:start position:0% +demand was higher you didn't +particularly have any gain because you + + align:start position:0% +particularly have any gain because you + + + align:start position:0% +particularly have any gain because you +only produce so much + + align:start position:0% +only produce so much + + + align:start position:0% +only produce so much +so that + + align:start position:0% +so that + + + align:start position:0% +so that +what you see here systematically when we + + align:start position:0% +what you see here systematically when we + + + align:start position:0% +what you see here systematically when we +think about the design itself + + align:start position:0% +think about the design itself + + + align:start position:0% +think about the design itself +the optimal design from a deterministic + + align:start position:0% +the optimal design from a deterministic + + + align:start position:0% +the optimal design from a deterministic +point of view and with an uncertain + + align:start position:0% +point of view and with an uncertain + + + align:start position:0% +point of view and with an uncertain +perspective can be lower now the amount + + align:start position:0% +perspective can be lower now the amount + + + align:start position:0% +perspective can be lower now the amount +it's lower here depends upon the + + align:start position:0% +it's lower here depends upon the + + + align:start position:0% +it's lower here depends upon the +uncertainty that we impose + + align:start position:0% +uncertainty that we impose + + + align:start position:0% +uncertainty that we impose +granted but the effect is + + align:start position:0% +granted but the effect is + + + align:start position:0% +granted but the effect is +it drives it slower that is the kind of + + align:start position:0% +it drives it slower that is the kind of + + + align:start position:0% +it drives it slower that is the kind of +effect you can imagine happening that + + align:start position:0% +effect you can imagine happening that + + + align:start position:0% +effect you can imagine happening that +you can sort of anticipate and it may + + align:start position:0% +you can sort of anticipate and it may + + + align:start position:0% +you can sort of anticipate and it may +not happen if the uncertainty was less + + align:start position:0% +not happen if the uncertainty was less + + + align:start position:0% +not happen if the uncertainty was less +maybe + + align:start position:0% +maybe + + + align:start position:0% +maybe +uh the uncertain design for the higher + + align:start position:0% +uh the uncertain design for the higher + + + align:start position:0% +uh the uncertain design for the higher +economies of scale might be the same + + align:start position:0% +economies of scale might be the same + + + align:start position:0% +economies of scale might be the same +here but and that's why it's a it's the + + align:start position:0% +here but and that's why it's a it's the + + + align:start position:0% +here but and that's why it's a it's the +uh lower or equal uh + + align:start position:0% +uh lower or equal uh + + + align:start position:0% +uh lower or equal uh +so this is not necessarily it but it is + + align:start position:0% +so this is not necessarily it but it is + + + align:start position:0% +so this is not necessarily it but it is +in this case + + align:start position:0% +in this case + + + align:start position:0% +in this case +by the same token + + align:start position:0% +by the same token + + + align:start position:0% +by the same token +we can think about the net present value + + align:start position:0% +we can think about the net present value + + + align:start position:0% +we can think about the net present value +of the project so here is the npv if + + align:start position:0% +of the project so here is the npv if + + + align:start position:0% +of the project so here is the npv if +uncertainty is ignored and it goes from + + align:start position:0% +uncertainty is ignored and it goes from + + + align:start position:0% +uncertainty is ignored and it goes from +uh it goes through these values and the + + align:start position:0% +uh it goes through these values and the + + + align:start position:0% +uh it goes through these values and the +moment we now recognize the uncertainty + + align:start position:0% +moment we now recognize the uncertainty + + + align:start position:0% +moment we now recognize the uncertainty +it says as we're given here we see that + + align:start position:0% +it says as we're given here we see that + + + align:start position:0% +it says as we're given here we see that +again it is they are lesser um than the + + align:start position:0% +again it is they are lesser um than the + + + align:start position:0% +again it is they are lesser um than the +uh + + align:start position:0% +uh + + + align:start position:0% +uh +than the ones with the deterministic + + align:start position:0% +than the ones with the deterministic + + + align:start position:0% +than the ones with the deterministic +analysis so these are sort of + + align:start position:0% +analysis so these are sort of + + + align:start position:0% +analysis so these are sort of +absolutely standard effects and the + + align:start position:0% +absolutely standard effects and the + + + align:start position:0% +absolutely standard effects and the +results from the + + align:start position:0% +results from the + + + align:start position:0% +results from the +flow of averages as they apply here to + + align:start position:0% +flow of averages as they apply here to + + + align:start position:0% +flow of averages as they apply here to +cap capacity constrained systems + + align:start position:0% +cap capacity constrained systems + + + align:start position:0% +cap capacity constrained systems +now + + align:start position:0% +now + + + align:start position:0% +now +this being lesser all the time when you + + align:start position:0% +this being lesser all the time when you + + + align:start position:0% +this being lesser all the time when you +recognize uncertainty applies to this + + align:start position:0% +recognize uncertainty applies to this + + + align:start position:0% +recognize uncertainty applies to this +kind of situation it does not apply + + align:start position:0% +kind of situation it does not apply + + + align:start position:0% +kind of situation it does not apply +necessarily we have network effects such + + align:start position:0% +necessarily we have network effects such + + + align:start position:0% +necessarily we have network effects such +as amazon or internet or google uh where + + align:start position:0% +as amazon or internet or google uh where + + + align:start position:0% +as amazon or internet or google uh where +it may pl the non-linearities play in + + align:start position:0% +it may pl the non-linearities play in + + + align:start position:0% +it may pl the non-linearities play in +the other way + + align:start position:0% +the other way + + + align:start position:0% +the other way +but the point being is that it's a clear + + align:start position:0% +but the point being is that it's a clear + + + align:start position:0% +but the point being is that it's a clear +evidence of the flaw of averages and the + + align:start position:0% +evidence of the flaw of averages and the + + + align:start position:0% +evidence of the flaw of averages and the +reason i bother spending time on the + + align:start position:0% +reason i bother spending time on the + + + align:start position:0% +reason i bother spending time on the +floor of averages is precisely because + + align:start position:0% +floor of averages is precisely because + + + align:start position:0% +floor of averages is precisely because +it drives these kinds of + + align:start position:0% +it drives these kinds of + + + align:start position:0% +it drives these kinds of +of differences in case of capacity + + align:start position:0% +of differences in case of capacity + + + align:start position:0% +of differences in case of capacity +constrained installations whether + + align:start position:0% +constrained installations whether + + + align:start position:0% +constrained installations whether +they're warehouses or electric power + + align:start position:0% +they're warehouses or electric power + + + align:start position:0% +they're warehouses or electric power +plants or whatever + + align:start position:0% +plants or whatever + + + align:start position:0% +plants or whatever +this is the kind of effect you would + + align:start position:0% +this is the kind of effect you would + + + align:start position:0% +this is the kind of effect you would +expect + + align:start position:0% + + + + align:start position:0% + +so a general lesson two + + align:start position:0% +so a general lesson two + + + align:start position:0% +so a general lesson two +i'm suggesting to you + + align:start position:0% +i'm suggesting to you + + + align:start position:0% +i'm suggesting to you +is that + + align:start position:0% +is that + + + align:start position:0% +is that +when invested in capacity limited + + align:start position:0% +when invested in capacity limited + + + align:start position:0% +when invested in capacity limited +facilities + + align:start position:0% +facilities + + + align:start position:0% +facilities +the realistic analysis of recognized + + align:start position:0% +the realistic analysis of recognized + + + align:start position:0% +the realistic analysis of recognized +uncertainty + + align:start position:0% +uncertainty + + + align:start position:0% +uncertainty +contrasts with the deterministic + + align:start position:0% +contrasts with the deterministic + + + align:start position:0% +contrasts with the deterministic +analysis + + align:start position:0% +analysis + + + align:start position:0% +analysis +that is + + align:start position:0% +that is + + + align:start position:0% +that is +you are if you deal with a deterministic + + align:start position:0% +you are if you deal with a deterministic + + + align:start position:0% +you are if you deal with a deterministic +analysis you're dealing with + + align:start position:0% +analysis you're dealing with + + + align:start position:0% +analysis you're dealing with +uh with basically a fairy tale that's a + + align:start position:0% +uh with basically a fairy tale that's a + + + align:start position:0% +uh with basically a fairy tale that's a +rather rude way of talking about it + + align:start position:0% +rather rude way of talking about it + + + align:start position:0% +rather rude way of talking about it +maybe because people are doing this all + + align:start position:0% +maybe because people are doing this all + + + align:start position:0% +maybe because people are doing this all +the time but the fact is you're dealing + + align:start position:0% +the time but the fact is you're dealing + + + align:start position:0% +the time but the fact is you're dealing +with an unrealistic situation and you + + align:start position:0% +with an unrealistic situation and you + + + align:start position:0% +with an unrealistic situation and you +are consequently going to get the wrong + + align:start position:0% +are consequently going to get the wrong + + + align:start position:0% +are consequently going to get the wrong +answer and in particular for the + + align:start position:0% +answer and in particular for the + + + align:start position:0% +answer and in particular for the +capacity constraint situation + + align:start position:0% +capacity constraint situation + + + align:start position:0% +capacity constraint situation +the + + align:start position:0% +the + + + align:start position:0% +the +realistic answer is that you have lower + + align:start position:0% +realistic answer is that you have lower + + + align:start position:0% +realistic answer is that you have lower +expected value and probably smaller + + align:start position:0% +expected value and probably smaller + + + align:start position:0% +expected value and probably smaller +modules are economically optimal + + align:start position:0% + + + + align:start position:0% + +and um + + align:start position:0% +and um + + + align:start position:0% +and um +all right so i will uh any i want to + + align:start position:0% +all right so i will uh any i want to + + + align:start position:0% +all right so i will uh any i want to +stop here again indra uh + + align:start position:0% +stop here again indra uh + + + align:start position:0% +stop here again indra uh +is there + + align:start position:0% +is there + + + align:start position:0% +is there +oop + + align:start position:0% +oop + + + align:start position:0% +oop +uh is there any uh question here uh that + + align:start position:0% +uh is there any uh question here uh that + + + align:start position:0% +uh is there any uh question here uh that +people would like to ask i want to be + + align:start position:0% +people would like to ask i want to be + + + align:start position:0% +people would like to ask i want to be +sure that this point is understood or + + align:start position:0% +sure that this point is understood or + + + align:start position:0% +sure that this point is understood or +if you debate it that we can have the + + align:start position:0% +if you debate it that we can have the + + + align:start position:0% +if you debate it that we can have the +debate about it and i can resolve any + + align:start position:0% +debate about it and i can resolve any + + + align:start position:0% +debate about it and i can resolve any +questions that might occur + + align:start position:0% +questions that might occur + + + align:start position:0% +questions that might occur +um + + align:start position:0% +um + + + align:start position:0% +um +if anyone has a question yeah we have + + align:start position:0% +if anyone has a question yeah we have + + + align:start position:0% +if anyone has a question yeah we have +joshua joshua go ahead + + align:start position:0% +joshua joshua go ahead + + + align:start position:0% +joshua joshua go ahead +professor just looking for clarification + + align:start position:0% +professor just looking for clarification + + + align:start position:0% +professor just looking for clarification +when you say that for capacity limited + + align:start position:0% +when you say that for capacity limited + + + align:start position:0% +when you say that for capacity limited +facilities or whatnot um + + align:start position:0% +facilities or whatnot um + + + align:start position:0% +facilities or whatnot um +you're taking away the upside because + + align:start position:0% +you're taking away the upside because + + + align:start position:0% +you're taking away the upside because +you can only go up to that capacity and + + align:start position:0% +you can only go up to that capacity and + + + align:start position:0% +you can only go up to that capacity and +so the uncertainty that's presented only + + align:start position:0% +so the uncertainty that's presented only + + + align:start position:0% +so the uncertainty that's presented only +provides you the downside up to the to + + align:start position:0% +provides you the downside up to the to + + + align:start position:0% +provides you the downside up to the to +up to that mean or the average + + align:start position:0% +up to that mean or the average + + + align:start position:0% +up to that mean or the average +and that's the major effect yes i mean + + align:start position:0% +and that's the major effect yes i mean + + + align:start position:0% +and that's the major effect yes i mean +you could think well + + align:start position:0% +you could think well + + + align:start position:0% +you could think well +maybe we could raise our prices for it + + align:start position:0% +maybe we could raise our prices for it + + + align:start position:0% +maybe we could raise our prices for it +so maybe we can compensate for you know + + align:start position:0% +so maybe we can compensate for you know + + + align:start position:0% +so maybe we can compensate for you know +if this is tight demand + + align:start position:0% +if this is tight demand + + + align:start position:0% +if this is tight demand +that implies there's no competition of + + align:start position:0% +that implies there's no competition of + + + align:start position:0% +that implies there's no competition of +course but uh + + align:start position:0% +course but uh + + + align:start position:0% +course but uh +so the major effect is in that direction + + align:start position:0% +so the major effect is in that direction + + + align:start position:0% +so the major effect is in that direction +and of course there are uh exceptions + + align:start position:0% +and of course there are uh exceptions + + + align:start position:0% +and of course there are uh exceptions +and modulate but that is the main effect + + align:start position:0% +and modulate but that is the main effect + + + align:start position:0% +and modulate but that is the main effect +that we're looking that one can account + + align:start position:0% +that we're looking that one can account + + + align:start position:0% +that we're looking that one can account +for yes that's what i meant to say are + + align:start position:0% +for yes that's what i meant to say are + + + align:start position:0% +for yes that's what i meant to say are +you concerned about that or + + align:start position:0% +you concerned about that or + + + align:start position:0% +you concerned about that or +um + + align:start position:0% +um + + + align:start position:0% +um +are you just validating it or what how + + align:start position:0% +are you just validating it or what how + + + align:start position:0% +are you just validating it or what how +are we listening how are you thinking + + align:start position:0% +are we listening how are you thinking + + + align:start position:0% +are we listening how are you thinking +about it i think that that makes a lot + + align:start position:0% +about it i think that that makes a lot + + + align:start position:0% +about it i think that that makes a lot +of sense and appreciate the + + align:start position:0% +of sense and appreciate the + + + align:start position:0% +of sense and appreciate the +clarification i think it's just um + + align:start position:0% +clarification i think it's just um + + + align:start position:0% +clarification i think it's just um +uh how do you + + align:start position:0% +uh how do you + + + align:start position:0% +uh how do you +how do you then um + + align:start position:0% +how do you then um + + + align:start position:0% +how do you then um +absorb the risk associated with allowing + + align:start position:0% +absorb the risk associated with allowing + + + align:start position:0% +absorb the risk associated with allowing +yourself + + align:start position:0% +yourself + + + align:start position:0% +yourself +to get the upside you know to get + + align:start position:0% +to get the upside you know to get + + + align:start position:0% +to get the upside you know to get +above the mean with capacity you you uh + + align:start position:0% +above the mean with capacity you you uh + + + align:start position:0% +above the mean with capacity you you uh +any business would would have + + align:start position:0% +any business would would have + + + align:start position:0% +any business would would have +significant risk in that case well + + align:start position:0% +significant risk in that case well + + + align:start position:0% +significant risk in that case well +that's where the modularity comes in + + align:start position:0% +that's where the modularity comes in + + + align:start position:0% +that's where the modularity comes in +because um + + align:start position:0% +because um + + + align:start position:0% +because um +this is recognizing uncertainty but it + + align:start position:0% +this is recognizing uncertainty but it + + + align:start position:0% +this is recognizing uncertainty but it +also means that okay well we're going to + + align:start position:0% +also means that okay well we're going to + + + align:start position:0% +also means that okay well we're going to +impose flex we're going to allow for + + align:start position:0% +impose flex we're going to allow for + + + align:start position:0% +impose flex we're going to allow for +flexibility we say right + + align:start position:0% +flexibility we say right + + + align:start position:0% +flexibility we say right +um if demand is picking up we're going + + align:start position:0% +um if demand is picking up we're going + + + align:start position:0% +um if demand is picking up we're going +to put in some more modules now + + align:start position:0% +to put in some more modules now + + + align:start position:0% +to put in some more modules now +uh in the garage case + + align:start position:0% +uh in the garage case + + + align:start position:0% +uh in the garage case +the starter set was you waited two years + + align:start position:0% +the starter set was you waited two years + + + align:start position:0% +the starter set was you waited two years +to see if the gross was there well + + align:start position:0% +to see if the gross was there well + + + align:start position:0% +to see if the gross was there well +depending upon the business and + + align:start position:0% +depending upon the business and + + + align:start position:0% +depending upon the business and +depending how long it takes to add the + + align:start position:0% +depending how long it takes to add the + + + align:start position:0% +depending how long it takes to add the +capacity you might decide to do it + + align:start position:0% +capacity you might decide to do it + + + align:start position:0% +capacity you might decide to do it +earlier or later or whatever but the + + align:start position:0% +earlier or later or whatever but the + + + align:start position:0% +earlier or later or whatever but the +idea is okay + + align:start position:0% +idea is okay + + + align:start position:0% +idea is okay +we have if we've planned this correctly + + align:start position:0% +we have if we've planned this correctly + + + align:start position:0% +we have if we've planned this correctly +we haven't forgotten the upside + + align:start position:0% +we haven't forgotten the upside + + + align:start position:0% +we haven't forgotten the upside +opportunity we just are going to make + + align:start position:0% +opportunity we just are going to make + + + align:start position:0% +opportunity we just are going to make +sure that it's around so if we're + + align:start position:0% +sure that it's around so if we're + + + align:start position:0% +sure that it's around so if we're +starting here in year zero + + align:start position:0% +starting here in year zero + + + align:start position:0% +starting here in year zero +uh year one we're not going to build all + + align:start position:0% +uh year one we're not going to build all + + + align:start position:0% +uh year one we're not going to build all +the way up for here we're going to say + + align:start position:0% +the way up for here we're going to say + + + align:start position:0% +the way up for here we're going to say +well + + align:start position:0% +well + + + align:start position:0% +well +when year three comes around and it + + align:start position:0% +when year three comes around and it + + + align:start position:0% +when year three comes around and it +looks like the capacity of the demand is + + align:start position:0% +looks like the capacity of the demand is + + + align:start position:0% +looks like the capacity of the demand is +really growing we're going to add + + align:start position:0% +really growing we're going to add + + + align:start position:0% +really growing we're going to add +capacity we haven't closed we haven't + + align:start position:0% +capacity we haven't closed we haven't + + + align:start position:0% +capacity we haven't closed we haven't +closed it off + + align:start position:0% +closed it off + + + align:start position:0% +closed it off +but in that particular year when there + + align:start position:0% +but in that particular year when there + + + align:start position:0% +but in that particular year when there +was demand was higher than we were at + + align:start position:0% +was demand was higher than we were at + + + align:start position:0% +was demand was higher than we were at +capacity for well we didn't gain as much + + align:start position:0% +capacity for well we didn't gain as much + + + align:start position:0% +capacity for well we didn't gain as much +but we'll catch it up uh somewhat later + + align:start position:0% +but we'll catch it up uh somewhat later + + + align:start position:0% +but we'll catch it up uh somewhat later +on so but if yeah that's what i'm saying + + align:start position:0% +on so but if yeah that's what i'm saying + + + align:start position:0% +on so but if yeah that's what i'm saying +for those of you who operated things i + + align:start position:0% +for those of you who operated things i + + + align:start position:0% +for those of you who operated things i +mean you have to realize that the + + align:start position:0% +mean you have to realize that the + + + align:start position:0% +mean you have to realize that the +capacity + + align:start position:0% +capacity + + + align:start position:0% +capacity +there's the plate capacity on the + + align:start position:0% +there's the plate capacity on the + + + align:start position:0% +there's the plate capacity on the +production facility and then there is + + align:start position:0% +production facility and then there is + + + align:start position:0% +production facility and then there is +the actual capacity because + + align:start position:0% +the actual capacity because + + + align:start position:0% +the actual capacity because +there's a glitch or you have to close it + + align:start position:0% +there's a glitch or you have to close it + + + align:start position:0% +there's a glitch or you have to close it +for maintenance or so forth and on the + + align:start position:0% +for maintenance or so forth and on the + + + align:start position:0% +for maintenance or so forth and on the +other hand you could have produced more + + align:start position:0% +other hand you could have produced more + + + align:start position:0% +other hand you could have produced more +than the plate capacity because you + + align:start position:0% +than the plate capacity because you + + + align:start position:0% +than the plate capacity because you +decided to work overtime and not and + + align:start position:0% +decided to work overtime and not and + + + align:start position:0% +decided to work overtime and not and +forgo maintenance for a while that you + + align:start position:0% +forgo maintenance for a while that you + + + align:start position:0% +forgo maintenance for a while that you +had assumed and so forth there are a lot + + align:start position:0% +had assumed and so forth there are a lot + + + align:start position:0% +had assumed and so forth there are a lot +of ways in which capacity is not like + + align:start position:0% +of ways in which capacity is not like + + + align:start position:0% +of ways in which capacity is not like +this cup of coffee which will only take + + align:start position:0% +this cup of coffee which will only take + + + align:start position:0% +this cup of coffee which will only take +so much and if it + + align:start position:0% +so much and if it + + + align:start position:0% +so much and if it +and you can't get any more into it but + + align:start position:0% +and you can't get any more into it but + + + align:start position:0% +and you can't get any more into it but +it's more like a capacity of people on a + + align:start position:0% +it's more like a capacity of people on a + + + align:start position:0% +it's more like a capacity of people on a +uh + + align:start position:0% +uh + + + align:start position:0% +uh +on a bus or on a subway car well it may + + align:start position:0% +on a bus or on a subway car well it may + + + align:start position:0% +on a bus or on a subway car well it may +say capacity for 20 standing and 30 + + align:start position:0% +say capacity for 20 standing and 30 + + + align:start position:0% +say capacity for 20 standing and 30 +seating but you all know situations + + align:start position:0% +seating but you all know situations + + + align:start position:0% +seating but you all know situations +where you've had greater capacity and + + align:start position:0% +where you've had greater capacity and + + + align:start position:0% +where you've had greater capacity and +others where right now you're not + + align:start position:0% +others where right now you're not + + + align:start position:0% +others where right now you're not +allowed to sit close together so the + + align:start position:0% +allowed to sit close together so the + + + align:start position:0% +allowed to sit close together so the +capacity is actually smaller so capacity + + align:start position:0% +capacity is actually smaller so capacity + + + align:start position:0% +capacity is actually smaller so capacity +is a rather + + align:start position:0% +is a rather + + + align:start position:0% +is a rather +uh in practice is somewhat of a fluid + + align:start position:0% +uh in practice is somewhat of a fluid + + + align:start position:0% +uh in practice is somewhat of a fluid +quite a bit of a fluid thing yes + + align:start position:0% +quite a bit of a fluid thing yes + + + align:start position:0% +quite a bit of a fluid thing yes +so + + align:start position:0% +so + + + align:start position:0% +so +um + + align:start position:0% +um + + + align:start position:0% +um +i'm trying to point to the general + + align:start position:0% +i'm trying to point to the general + + + align:start position:0% +i'm trying to point to the general +phenomenon here um but the ways in which + + align:start position:0% +phenomenon here um but the ways in which + + + align:start position:0% +phenomenon here um but the ways in which +in the real world it gets to be + + align:start position:0% +in the real world it gets to be + + + align:start position:0% +in the real world it gets to be +complicated yes absolutely + + align:start position:0% +complicated yes absolutely + + + align:start position:0% +complicated yes absolutely +and + + align:start position:0% +and + + + align:start position:0% +and +um + + align:start position:0% +um + + + align:start position:0% +um +right my work now with this moroccan + + align:start position:0% +right my work now with this moroccan + + + align:start position:0% +right my work now with this moroccan +company is exploring exactly those kinds + + align:start position:0% +company is exploring exactly those kinds + + + align:start position:0% +company is exploring exactly those kinds +of issues so + + align:start position:0% +of issues so + + + align:start position:0% +of issues so +just to say that uh i'll pass over this + + align:start position:0% +just to say that uh i'll pass over this + + + align:start position:0% +just to say that uh i'll pass over this +slide which is simply to say that once + + align:start position:0% +slide which is simply to say that once + + + align:start position:0% +slide which is simply to say that once +you move + + align:start position:0% +you move + + + align:start position:0% +you move +to + + align:start position:0% +to + + + align:start position:0% +to +thinking about not just a combination of + + align:start position:0% +thinking about not just a combination of + + + align:start position:0% +thinking about not just a combination of +size and timing but also add that other + + align:start position:0% +size and timing but also add that other + + + align:start position:0% +size and timing but also add that other +dimension of location in this case of + + align:start position:0% +dimension of location in this case of + + + align:start position:0% +dimension of location in this case of +five possible locations um that the + + align:start position:0% +five possible locations um that the + + + align:start position:0% +five possible locations um that the +complexity of uh + + align:start position:0% +complexity of uh + + + align:start position:0% +complexity of uh +of the analysis increases greatly and um + + align:start position:0% +of the analysis increases greatly and um + + + align:start position:0% +of the analysis increases greatly and um +so the analysis is more complicated + + align:start position:0% +so the analysis is more complicated + + + align:start position:0% +so the analysis is more complicated +but that's just as a footnote + + align:start position:0% +but that's just as a footnote + + + align:start position:0% +but that's just as a footnote +so now let's look at the optimal design + + align:start position:0% +so now let's look at the optimal design + + + align:start position:0% +so now let's look at the optimal design +here and this is again very similar to + + align:start position:0% +here and this is again very similar to + + + align:start position:0% +here and this is again very similar to +the + + align:start position:0% +the + + + align:start position:0% +the +garage case where + + align:start position:0% +garage case where + + + align:start position:0% +garage case where +the + + align:start position:0% +the + + + align:start position:0% +the +building it large + + align:start position:0% +building it large + + + align:start position:0% +building it large +and fixed + + align:start position:0% +and fixed + + + align:start position:0% +and fixed +uh has the + + align:start position:0% +uh has the + + + align:start position:0% +uh has the +this performance here for these numbers + + align:start position:0% +this performance here for these numbers + + + align:start position:0% +this performance here for these numbers +an expected value uh quite reasonable + + align:start position:0% +an expected value uh quite reasonable + + + align:start position:0% +an expected value uh quite reasonable +but uh it could be if you build it + + align:start position:0% +but uh it could be if you build it + + + align:start position:0% +but uh it could be if you build it +nobody comes sort of the way it was the + + align:start position:0% +nobody comes sort of the way it was the + + + align:start position:0% +nobody comes sort of the way it was the +first years of the salting plant you + + align:start position:0% +first years of the salting plant you + + + align:start position:0% +first years of the salting plant you +could have a big loss + + align:start position:0% +could have a big loss + + + align:start position:0% +could have a big loss +and your capacity limited to a certain + + align:start position:0% +and your capacity limited to a certain + + + align:start position:0% +and your capacity limited to a certain +amount + + align:start position:0% +amount + + + align:start position:0% +amount +um + + align:start position:0% +um + + + align:start position:0% +um +if you had a flexible modular uh + + align:start position:0% +if you had a flexible modular uh + + + align:start position:0% +if you had a flexible modular uh +solution where you allowed yourself to + + align:start position:0% +solution where you allowed yourself to + + + align:start position:0% +solution where you allowed yourself to +time the + + align:start position:0% +time the + + + align:start position:0% +time the +increases of capacity according to the + + align:start position:0% +increases of capacity according to the + + + align:start position:0% +increases of capacity according to the +demand you weren't going to lose very + + align:start position:0% +demand you weren't going to lose very + + + align:start position:0% +demand you weren't going to lose very +much because you started small and + + align:start position:0% +much because you started small and + + + align:start position:0% +much because you started small and +um there was a lot not so much to lose + + align:start position:0% +um there was a lot not so much to lose + + + align:start position:0% +um there was a lot not so much to lose +and uh + + align:start position:0% +and uh + + + align:start position:0% +and uh +the losses uh were + + align:start position:0% +the losses uh were + + + align:start position:0% +the losses uh were +several a couple million dollars by this + + align:start position:0% +several a couple million dollars by this + + + align:start position:0% +several a couple million dollars by this +comparison + + align:start position:0% +comparison + + + align:start position:0% +comparison +uh but if the demand really picked up + + align:start position:0% +uh but if the demand really picked up + + + align:start position:0% +uh but if the demand really picked up +you could expand expand expand so that + + align:start position:0% +you could expand expand expand so that + + + align:start position:0% +you could expand expand expand so that +you had a much better performance + + align:start position:0% +you had a much better performance + + + align:start position:0% +you had a much better performance +overall and in this case as often + + align:start position:0% +overall and in this case as often + + + align:start position:0% +overall and in this case as often +happens but not necessarily the flexible + + align:start position:0% +happens but not necessarily the flexible + + + align:start position:0% +happens but not necessarily the flexible +demand compared with the inflexible + + align:start position:0% +demand compared with the inflexible + + + align:start position:0% +demand compared with the inflexible +demand perform + + align:start position:0% +demand perform + + + align:start position:0% +demand perform +was better overall + + align:start position:0% +was better overall + + + align:start position:0% +was better overall +so that was uh + + align:start position:0% +so that was uh + + + align:start position:0% +so that was uh +that was that those target curves for + + align:start position:0% +that was that those target curves for + + + align:start position:0% +that was that those target curves for +that comparison + + align:start position:0% +that comparison + + + align:start position:0% +that comparison +um + + align:start position:0% +um + + + align:start position:0% +um +and + + align:start position:0% +and + + + align:start position:0% +and +note by the way that the increase in + + align:start position:0% +note by the way that the increase in + + + align:start position:0% +note by the way that the increase in +value so of course this is not + + align:start position:0% +value so of course this is not + + + align:start position:0% +value so of course this is not +guaranteed but in this particular case + + align:start position:0% +guaranteed but in this particular case + + + align:start position:0% +guaranteed but in this particular case +was from about 14 and changed to about + + align:start position:0% +was from about 14 and changed to about + + + align:start position:0% +was from about 14 and changed to about +21 which is about 50 increase in value + + align:start position:0% +21 which is about 50 increase in value + + + align:start position:0% +21 which is about 50 increase in value +so that with no new technology nothing + + align:start position:0% +so that with no new technology nothing + + + align:start position:0% +so that with no new technology nothing +no sort of miraculum involved you can + + align:start position:0% +no sort of miraculum involved you can + + + align:start position:0% +no sort of miraculum involved you can +increase + + align:start position:0% +increase + + + align:start position:0% +increase +simply by recognizing uncertainty you + + align:start position:0% +simply by recognizing uncertainty you + + + align:start position:0% +simply by recognizing uncertainty you +could increase the perspective expect + + align:start position:0% +could increase the perspective expect + + + align:start position:0% +could increase the perspective expect +perspective expected value by 50 it's + + align:start position:0% +perspective expected value by 50 it's + + + align:start position:0% +perspective expected value by 50 it's +really quite remarkable and + + align:start position:0% +really quite remarkable and + + + align:start position:0% +really quite remarkable and +of course there are details about how it + + align:start position:0% +of course there are details about how it + + + align:start position:0% +of course there are details about how it +actually gonna work out and so forth + + align:start position:0% +actually gonna work out and so forth + + + align:start position:0% +actually gonna work out and so forth +but it + + align:start position:0% +but it + + + align:start position:0% +but it +emphasizes the great prospects for + + align:start position:0% +emphasizes the great prospects for + + + align:start position:0% +emphasizes the great prospects for +flexible design under some circumstances + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/izl46nTo1ng.txt b/izl46nTo1ng.txt new file mode 100644 index 0000000000000000000000000000000000000000..c0230cee7fb8cc80769667c5824ff356e569aaef --- /dev/null +++ b/izl46nTo1ng.txt @@ -0,0 +1,17149 @@ +align:start position:0% + +so this is an outline of what i'm going + + align:start position:0% +so this is an outline of what i'm going + + + align:start position:0% +so this is an outline of what i'm going +to talk about and we're going to begin + + align:start position:0% +to talk about and we're going to begin + + + align:start position:0% +to talk about and we're going to begin +by sort of + + align:start position:0% +by sort of + + + align:start position:0% +by sort of +getting at this question of why complex + + align:start position:0% +getting at this question of why complex + + + align:start position:0% +getting at this question of why complex +trait human genetics is so difficult + + align:start position:0% +trait human genetics is so difficult + + + align:start position:0% +trait human genetics is so difficult +um and then go through each of the steps + + align:start position:0% +um and then go through each of the steps + + + align:start position:0% +um and then go through each of the steps +that you would do if you were actually + + align:start position:0% +that you would do if you were actually + + + align:start position:0% +that you would do if you were actually +doing this work the first question you + + align:start position:0% +doing this work the first question you + + + align:start position:0% +doing this work the first question you +would get asked on an nih grant + + align:start position:0% +would get asked on an nih grant + + + align:start position:0% +would get asked on an nih grant +application is is your phenotype + + align:start position:0% +application is is your phenotype + + + align:start position:0% +application is is your phenotype +heritable + + align:start position:0% +heritable + + + align:start position:0% +heritable +and so some evidence of heritability or + + align:start position:0% +and so some evidence of heritability or + + + align:start position:0% +and so some evidence of heritability or +doing a study to determine heritability + + align:start position:0% +doing a study to determine heritability + + + align:start position:0% +doing a study to determine heritability +is often the first step in in a genetic + + align:start position:0% +is often the first step in in a genetic + + + align:start position:0% +is often the first step in in a genetic +study + + align:start position:0% +study + + + align:start position:0% +study +so we're going to talk a little bit + + align:start position:0% +so we're going to talk a little bit + + + align:start position:0% +so we're going to talk a little bit +about heritability and how you define + + align:start position:0% +about heritability and how you define + + + align:start position:0% +about heritability and how you define +that and then identifying disease + + align:start position:0% +that and then identifying disease + + + align:start position:0% +that and then identifying disease +phenotypes so that's a critical issue + + align:start position:0% + + + + align:start position:0% + +the difference between a sub-phenotype + + align:start position:0% +the difference between a sub-phenotype + + + align:start position:0% +the difference between a sub-phenotype +and an intermediate phenotype + + align:start position:0% +and an intermediate phenotype + + + align:start position:0% +and an intermediate phenotype +um + + align:start position:0% + + + + align:start position:0% + +how you want to look at those things + + align:start position:0% +how you want to look at those things + + + align:start position:0% +how you want to look at those things +then developing your study design + + align:start position:0% +then developing your study design + + + align:start position:0% +then developing your study design +um + + align:start position:0% +um + + + align:start position:0% +um +the paper that i just was telling you + + align:start position:0% +the paper that i just was telling you + + + align:start position:0% +the paper that i just was telling you +about this paper that's coming out in + + align:start position:0% +about this paper that's coming out in + + + align:start position:0% +about this paper that's coming out in +science + + align:start position:0% +science + + + align:start position:0% +science +these people looked at two relative + + align:start position:0% +these people looked at two relative + + + align:start position:0% +these people looked at two relative +genetic isolates the population of + + align:start position:0% +genetic isolates the population of + + + align:start position:0% +genetic isolates the population of +finland and the uh uh saginay loch + + align:start position:0% +finland and the uh uh saginay loch + + + align:start position:0% +finland and the uh uh saginay loch +sanchez population in northeast quebec + + align:start position:0% +sanchez population in northeast quebec + + + align:start position:0% +sanchez population in northeast quebec +french canadians + + align:start position:0% +french canadians + + + align:start position:0% +french canadians +so these are populations where they had + + align:start position:0% +so these are populations where they had + + + align:start position:0% +so these are populations where they had +a limited number of founders + + align:start position:0% +a limited number of founders + + + align:start position:0% +a limited number of founders +and so uh the thought is is that they're + + align:start position:0% +and so uh the thought is is that they're + + + align:start position:0% +and so uh the thought is is that they're +more genetically homogeneous and it + + align:start position:0% +more genetically homogeneous and it + + + align:start position:0% +more genetically homogeneous and it +might be easier to find genes in these + + align:start position:0% +might be easier to find genes in these + + + align:start position:0% +might be easier to find genes in these +populations but what's the big concern + + align:start position:0% +populations but what's the big concern + + + align:start position:0% +populations but what's the big concern +if you found a gene in the fins + + align:start position:0% +if you found a gene in the fins + + + align:start position:0% +if you found a gene in the fins +what would be your biggest concern about + + align:start position:0% +what would be your biggest concern about + + + align:start position:0% +what would be your biggest concern about +about that + + align:start position:0% +about that + + + align:start position:0% +about that +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +exactly that you know maybe that gene + + align:start position:0% +exactly that you know maybe that gene + + + align:start position:0% +exactly that you know maybe that gene +might not replicate or be a significant + + align:start position:0% +might not replicate or be a significant + + + align:start position:0% +might not replicate or be a significant +gene in an outbred population you know + + align:start position:0% +gene in an outbred population you know + + + align:start position:0% +gene in an outbred population you know +in a country such as the united states + + align:start position:0% +in a country such as the united states + + + align:start position:0% +in a country such as the united states +where there's a lot of + + align:start position:0% +where there's a lot of + + + align:start position:0% +where there's a lot of +uh + + align:start position:0% +uh + + + align:start position:0% +uh +ethnic variation and diversity so + + align:start position:0% +ethnic variation and diversity so + + + align:start position:0% +ethnic variation and diversity so +it may be easier to find genes in + + align:start position:0% +it may be easier to find genes in + + + align:start position:0% +it may be easier to find genes in +genetic isolates but it may be more + + align:start position:0% +genetic isolates but it may be more + + + align:start position:0% +genetic isolates but it may be more +difficult + + align:start position:0% +difficult + + + align:start position:0% +difficult +in terms of their generalizability so + + align:start position:0% +in terms of their generalizability so + + + align:start position:0% +in terms of their generalizability so +give me some other examples of + + align:start position:0% +give me some other examples of + + + align:start position:0% +give me some other examples of +relative genetic isolates around the + + align:start position:0% +relative genetic isolates around the + + + align:start position:0% +relative genetic isolates around the +world populations that would be + + align:start position:0% +world populations that would be + + + align:start position:0% +world populations that would be +considered relative genetic isolates + + align:start position:0% + + + + align:start position:0% + +iceland yes absolutely iceland so that's + + align:start position:0% +iceland yes absolutely iceland so that's + + + align:start position:0% +iceland yes absolutely iceland so that's +where decode is + + align:start position:0% +where decode is + + + align:start position:0% +where decode is +is working decode is our number one + + align:start position:0% +is working decode is our number one + + + align:start position:0% +is working decode is our number one +competitor in copd research they're the + + align:start position:0% +competitor in copd research they're the + + + align:start position:0% +competitor in copd research they're the +only + + align:start position:0% +only + + + align:start position:0% +only +company that that's actually doing uh um + + align:start position:0% +company that that's actually doing uh um + + + align:start position:0% +company that that's actually doing uh um +copd stuff + + align:start position:0% +copd stuff + + + align:start position:0% +copd stuff +what else where else could you go + + align:start position:0% + + + + align:start position:0% + +what might be the disadvantage of a + + align:start position:0% +what might be the disadvantage of a + + + align:start position:0% +what might be the disadvantage of a +tribal population or a disadvantage of a + + align:start position:0% +tribal population or a disadvantage of a + + + align:start position:0% +tribal population or a disadvantage of a +of a small + + align:start position:0% +of a small + + + align:start position:0% +of a small +island population like tristan de cunha + + align:start position:0% +island population like tristan de cunha + + + align:start position:0% +island population like tristan de cunha +which is where they first went to do + + align:start position:0% +which is where they first went to do + + + align:start position:0% +which is where they first went to do +genetic isolate work in in asthma + + align:start position:0% + + + + align:start position:0% + +yeah small number of people so + + align:start position:0% +yeah small number of people so + + + align:start position:0% +yeah small number of people so +you know you got a limited number of uh + + align:start position:0% +you know you got a limited number of uh + + + align:start position:0% +you know you got a limited number of uh +meiosis in a population like that you're + + align:start position:0% +meiosis in a population like that you're + + + align:start position:0% +meiosis in a population like that you're +not going to get too many recombinations + + align:start position:0% +not going to get too many recombinations + + + align:start position:0% +not going to get too many recombinations +so you just sort of run out of gas + + align:start position:0% +so you just sort of run out of gas + + + align:start position:0% +so you just sort of run out of gas +because you don't have a big enough + + align:start position:0% +because you don't have a big enough + + + align:start position:0% +because you don't have a big enough +sample size let's + + align:start position:0% +sample size let's + + + align:start position:0% +sample size let's +switch boundaries + + align:start position:0% +switch boundaries + + + align:start position:0% +switch boundaries +possibly um the fins the swiss + + align:start position:0% +possibly um the fins the swiss + + + align:start position:0% +possibly um the fins the swiss +uh the northern uh um + + align:start position:0% +uh the northern uh um + + + align:start position:0% +uh the northern uh um +um the um + + align:start position:0% +um the um + + + align:start position:0% +um the um +ashkenazi jews um + + align:start position:0% +ashkenazi jews um + + + align:start position:0% +ashkenazi jews um +costa rica + + align:start position:0% + + + + align:start position:0% + +why costa rica + + align:start position:0% +why costa rica + + + align:start position:0% +why costa rica +why costa rica because + + align:start position:0% +why costa rica because + + + align:start position:0% +why costa rica because +costa rica is surrounded by volcanoes it + + align:start position:0% +costa rica is surrounded by volcanoes it + + + align:start position:0% +costa rica is surrounded by volcanoes it +was the one place in central america + + align:start position:0% +was the one place in central america + + + align:start position:0% +was the one place in central america +that uh the span you know there's not a + + align:start position:0% +that uh the span you know there's not a + + + align:start position:0% +that uh the span you know there's not a +huge + + align:start position:0% +huge + + + align:start position:0% +huge +spanish influx because there was no gold + + align:start position:0% +spanish influx because there was no gold + + + align:start position:0% +spanish influx because there was no gold +there so there's a limited number of + + align:start position:0% +there so there's a limited number of + + + align:start position:0% +there so there's a limited number of +spanish founders in the 15th century + + align:start position:0% +spanish founders in the 15th century + + + align:start position:0% +spanish founders in the 15th century +they + + align:start position:0% +they + + + align:start position:0% +they +pushed the indians to the + + align:start position:0% +pushed the indians to the + + + align:start position:0% +pushed the indians to the +periphery and they settled the + + align:start position:0% +periphery and they settled the + + + align:start position:0% +periphery and they settled the +central valley of costa rica so you've + + align:start position:0% +central valley of costa rica so you've + + + align:start position:0% +central valley of costa rica so you've +got this + + align:start position:0% +got this + + + align:start position:0% +got this +200 founders + + align:start position:0% +200 founders + + + align:start position:0% +200 founders +in the 14th century very little + + align:start position:0% +in the 14th century very little + + + align:start position:0% +in the 14th century very little +intermarriage and perfect church records + + align:start position:0% +intermarriage and perfect church records + + + align:start position:0% +intermarriage and perfect church records +very large pedigrees it's one of the + + align:start position:0% +very large pedigrees it's one of the + + + align:start position:0% +very large pedigrees it's one of the +it's probably the closest next to the + + align:start position:0% +it's probably the closest next to the + + + align:start position:0% +it's probably the closest next to the +saginay lock science gen population in + + align:start position:0% +saginay lock science gen population in + + + align:start position:0% +saginay lock science gen population in +quebec + + align:start position:0% +quebec + + + align:start position:0% +quebec +genetic isolates uh in the western + + align:start position:0% +genetic isolates uh in the western + + + align:start position:0% +genetic isolates uh in the western +hemisphere and we're actually doing a + + align:start position:0% +hemisphere and we're actually doing a + + + align:start position:0% +hemisphere and we're actually doing a +big study there we actually have six big + + align:start position:0% +big study there we actually have six big + + + align:start position:0% +big study there we actually have six big +pedigrees with over 120 people in each + + align:start position:0% +pedigrees with over 120 people in each + + + align:start position:0% +pedigrees with over 120 people in each +pedigree + + align:start position:0% +pedigree + + + align:start position:0% +pedigree +we've just finished the collection of + + align:start position:0% +we've just finished the collection of + + + align:start position:0% +we've just finished the collection of +these pedigrees we're about to do a + + align:start position:0% +these pedigrees we're about to do a + + + align:start position:0% +these pedigrees we're about to do a +genome scan + + align:start position:0% +genome scan + + + align:start position:0% +genome scan +that tom is actually doing for us + + align:start position:0% +that tom is actually doing for us + + + align:start position:0% +that tom is actually doing for us +most of the + + align:start position:0% +most of the + + + align:start position:0% +most of the +people are isolated by geography that + + align:start position:0% +people are isolated by geography that + + + align:start position:0% +people are isolated by geography that +you've mentioned with the exception of + + align:start position:0% +you've mentioned with the exception of + + + align:start position:0% +you've mentioned with the exception of +the + + align:start position:0% +the + + + align:start position:0% +the +nazis right so + + align:start position:0% +nazis right so + + + align:start position:0% +nazis right so +we can broaden + + align:start position:0% +we can broaden + + + align:start position:0% +we can broaden +uh your i guess the definition of + + align:start position:0% +uh your i guess the definition of + + + align:start position:0% +uh your i guess the definition of +genetic isolate to include things like + + align:start position:0% +genetic isolate to include things like + + + align:start position:0% +genetic isolate to include things like +economic like things that utilize it + + align:start position:0% +economic like things that utilize it + + + align:start position:0% +economic like things that utilize it +people like you know royal families back + + align:start position:0% +people like you know royal families back + + + align:start position:0% +people like you know royal families back +in the old days you know i only were + + align:start position:0% +in the old days you know i only were + + + align:start position:0% +in the old days you know i only were +married because of social status and yes + + align:start position:0% +married because of social status and yes + + + align:start position:0% +married because of social status and yes +but now there's things where you know + + align:start position:0% +but now there's things where you know + + + align:start position:0% +but now there's things where you know +people with certain economic status mail + + align:start position:0% +people with certain economic status mail + + + align:start position:0% +people with certain economic status mail +me + + align:start position:0% +me + + + align:start position:0% +me +and then they come in here can we + + align:start position:0% +and then they come in here can we + + + align:start position:0% +and then they come in here can we +see a certain set of people where + + align:start position:0% +see a certain set of people where + + + align:start position:0% +see a certain set of people where +they're married + + align:start position:0% +they're married + + + align:start position:0% +they're married +yeah it turns out i think that geography + + align:start position:0% +yeah it turns out i think that geography + + + align:start position:0% +yeah it turns out i think that geography +is actually a much better + + align:start position:0% +is actually a much better + + + align:start position:0% +is actually a much better +uh uh um + + align:start position:0% + + + + align:start position:0% + +i think i think that yeah i think if it + + align:start position:0% +i think i think that yeah i think if it + + + align:start position:0% +i think i think that yeah i think if it +was happening families or people have a + + align:start position:0% +was happening families or people have a + + + align:start position:0% +was happening families or people have a +chance to procreate by physical + + align:start position:0% +chance to procreate by physical + + + align:start position:0% +chance to procreate by physical +proximity they will + + align:start position:0% + + + + align:start position:0% + +i think the geography is a lot better + + align:start position:0% +i think the geography is a lot better + + + align:start position:0% +i think the geography is a lot better +um + + align:start position:0% +um + + + align:start position:0% +um +historically it's + + align:start position:0% +historically it's + + + align:start position:0% +historically it's +a much more reliable + + align:start position:0% +a much more reliable + + + align:start position:0% +a much more reliable +guide to a genetic isolate than any sort + + align:start position:0% +guide to a genetic isolate than any sort + + + align:start position:0% +guide to a genetic isolate than any sort +of social convention i think + + align:start position:0% +of social convention i think + + + align:start position:0% +of social convention i think +er er er exactly for the reasons that + + align:start position:0% +er er er exactly for the reasons that + + + align:start position:0% +er er er exactly for the reasons that +zach + + align:start position:0% +zach + + + align:start position:0% +zach +groups like + + align:start position:0% +groups like + + + align:start position:0% +groups like +jerusalem they're so strong social + + align:start position:0% +jerusalem they're so strong social + + + align:start position:0% +jerusalem they're so strong social +pressure yeah like then you know what + + align:start position:0% +pressure yeah like then you know what + + + align:start position:0% +pressure yeah like then you know what +that would they may be they may be the + + align:start position:0% +that would they may be they may be the + + + align:start position:0% +that would they may be they may be the +exception to the rule but i think you + + align:start position:0% +exception to the rule but i think you + + + align:start position:0% +exception to the rule but i think you +know populations like iceland costa rica + + align:start position:0% +know populations like iceland costa rica + + + align:start position:0% +know populations like iceland costa rica +um tristan de cunha finland + + align:start position:0% + + + + align:start position:0% + +amish would would + + align:start position:0% +amish would would + + + align:start position:0% +amish would would +fall into fall into that group the + + align:start position:0% +fall into fall into that group the + + + align:start position:0% +fall into fall into that group the +mormons + + align:start position:0% +mormons + + + align:start position:0% +mormons +maybe a little bit less so + + align:start position:0% +maybe a little bit less so + + + align:start position:0% +maybe a little bit less so +um the big advantage of the mormons is + + align:start position:0% +um the big advantage of the mormons is + + + align:start position:0% +um the big advantage of the mormons is +not so much that they're a relative + + align:start position:0% +not so much that they're a relative + + + align:start position:0% +not so much that they're a relative +genetic isolate but that they have very + + align:start position:0% +genetic isolate but that they have very + + + align:start position:0% +genetic isolate but that they have very +large families and they have very good + + align:start position:0% +large families and they have very good + + + align:start position:0% +large families and they have very good +church records so you know those are + + align:start position:0% +church records so you know those are + + + align:start position:0% +church records so you know those are +sort of other + + align:start position:0% +sort of other + + + align:start position:0% +sort of other +characteristics that sort of are helpful + + align:start position:0% +characteristics that sort of are helpful + + + align:start position:0% +characteristics that sort of are helpful +but the + + align:start position:0% +but the + + + align:start position:0% +but the +idea behind the genetic isolate is is + + align:start position:0% +idea behind the genetic isolate is is + + + align:start position:0% +idea behind the genetic isolate is is +that you've got a relatively + + align:start position:0% +that you've got a relatively + + + align:start position:0% +that you've got a relatively +uh + + align:start position:0% +uh + + + align:start position:0% +uh +homogeneous + + align:start position:0% +homogeneous + + + align:start position:0% +homogeneous +set of alleles that circulating in the + + align:start position:0% +set of alleles that circulating in the + + + align:start position:0% +set of alleles that circulating in the +population mormons do + + align:start position:0% +population mormons do + + + align:start position:0% +population mormons do +intermarry and and so they're maybe + + align:start position:0% +intermarry and and so they're maybe + + + align:start position:0% +intermarry and and so they're maybe +i don't i don't know that you'd consider + + align:start position:0% +i don't i don't know that you'd consider + + + align:start position:0% +i don't i don't know that you'd consider +them really a genetic isolate whereas uh + + align:start position:0% +them really a genetic isolate whereas uh + + + align:start position:0% +them really a genetic isolate whereas uh +uh i think that uh the amish and the + + align:start position:0% +uh i think that uh the amish and the + + + align:start position:0% +uh i think that uh the amish and the +hutterites and the uh um ashkenazis are + + align:start position:0% +hutterites and the uh um ashkenazis are + + + align:start position:0% +hutterites and the uh um ashkenazis are +people where there is some set of + + align:start position:0% +people where there is some set of + + + align:start position:0% +people where there is some set of +co-social conventions that those people + + align:start position:0% +co-social conventions that those people + + + align:start position:0% +co-social conventions that those people +are much more likely to uh intermarry + + align:start position:0% +are much more likely to uh intermarry + + + align:start position:0% +are much more likely to uh intermarry +the reason i ask is because it seems + + align:start position:0% +the reason i ask is because it seems + + + align:start position:0% +the reason i ask is because it seems +like + + align:start position:0% +like + + + align:start position:0% +like +that the trend might be uh + + align:start position:0% +that the trend might be uh + + + align:start position:0% +that the trend might be uh +you know especially nowadays with + + align:start position:0% +you know especially nowadays with + + + align:start position:0% +you know especially nowadays with +transportation leaders that finding + + align:start position:0% +transportation leaders that finding + + + align:start position:0% +transportation leaders that finding +geographic isolated population is going + + align:start position:0% +geographic isolated population is going + + + align:start position:0% +geographic isolated population is going +to decline + + align:start position:0% +to decline + + + align:start position:0% +to decline +right this isn't this isn't the only way + + align:start position:0% +right this isn't this isn't the only way + + + align:start position:0% +right this isn't this isn't the only way +to do this i mean uh um + + align:start position:0% +to do this i mean uh um + + + align:start position:0% +to do this i mean uh um +and i think it is important to sort of + + align:start position:0% +and i think it is important to sort of + + + align:start position:0% +and i think it is important to sort of +make the distinction between + + align:start position:0% +make the distinction between + + + align:start position:0% +make the distinction between +uh uh um + + align:start position:0% + + + + align:start position:0% + +you know linkage and fine mapping + + align:start position:0% +you know linkage and fine mapping + + + align:start position:0% +you know linkage and fine mapping +and uh um those two things may be + + align:start position:0% +and uh um those two things may be + + + align:start position:0% +and uh um those two things may be +somewhat different the the the + + align:start position:0% +somewhat different the the the + + + align:start position:0% +somewhat different the the the +advantages of an outbred population is + + align:start position:0% +advantages of an outbred population is + + + align:start position:0% +advantages of an outbred population is +is that the + + align:start position:0% +is that the + + + align:start position:0% +is that the +degree of linkage this equilibrium will + + align:start position:0% +degree of linkage this equilibrium will + + + align:start position:0% +degree of linkage this equilibrium will +be relatively narrow and some of these + + align:start position:0% +be relatively narrow and some of these + + + align:start position:0% +be relatively narrow and some of these +genetic isolated populations the degree + + align:start position:0% +genetic isolated populations the degree + + + align:start position:0% +genetic isolated populations the degree +of linkage to secretion can be very + + align:start position:0% +of linkage to secretion can be very + + + align:start position:0% +of linkage to secretion can be very +large that means you can get + + align:start position:0% +large that means you can get + + + align:start position:0% +large that means you can get +do the do the linkage part pretty + + align:start position:0% +do the do the linkage part pretty + + + align:start position:0% +do the do the linkage part pretty +effectively but the association part is + + align:start position:0% +effectively but the association part is + + + align:start position:0% +effectively but the association part is +more difficult because you've got these + + align:start position:0% +more difficult because you've got these + + + align:start position:0% +more difficult because you've got these +big ld blocks that you've got to uh + + align:start position:0% +big ld blocks that you've got to uh + + + align:start position:0% +big ld blocks that you've got to uh +work with and you may not be able to get + + align:start position:0% +work with and you may not be able to get + + + align:start position:0% +work with and you may not be able to get +to + + align:start position:0% +to + + + align:start position:0% +to +to the gene + + align:start position:0% +to the gene + + + align:start position:0% +to the gene +um + + align:start position:0% +um + + + align:start position:0% +um +so anyway we'll go through the stuff + + align:start position:0% + + + + align:start position:0% + +these are sort of all of the steps that + + align:start position:0% +these are sort of all of the steps that + + + align:start position:0% +these are sort of all of the steps that +you would do in a typical study and + + align:start position:0% +you would do in a typical study and + + + align:start position:0% +you would do in a typical study and +we'll just go through each of these so + + align:start position:0% +we'll just go through each of these so + + + align:start position:0% +we'll just go through each of these so +i'm going to use asthma as my example + + align:start position:0% +i'm going to use asthma as my example + + + align:start position:0% +i'm going to use asthma as my example +because this is the disease i know the + + align:start position:0% +because this is the disease i know the + + + align:start position:0% +because this is the disease i know the +best and the point here is is that + + align:start position:0% +best and the point here is is that + + + align:start position:0% +best and the point here is is that +asthma prevalence in western developed + + align:start position:0% +asthma prevalence in western developed + + + align:start position:0% +asthma prevalence in western developed +countries has gone up a lot so do you + + align:start position:0% +countries has gone up a lot so do you + + + align:start position:0% +countries has gone up a lot so do you +think that this is a genetic thing or do + + align:start position:0% +think that this is a genetic thing or do + + + align:start position:0% +think that this is a genetic thing or do +you think it's + + align:start position:0% +you think it's + + + align:start position:0% +you think it's +something else + + align:start position:0% +something else + + + align:start position:0% +something else +so over the 20-year period sort of 82 + + align:start position:0% +so over the 20-year period sort of 82 + + + align:start position:0% +so over the 20-year period sort of 82 +000 you've had more than a doubling in + + align:start position:0% +000 you've had more than a doubling in + + + align:start position:0% +000 you've had more than a doubling in +the number of cases so over a 20-year + + align:start position:0% +the number of cases so over a 20-year + + + align:start position:0% +the number of cases so over a 20-year +period doubling in the number of cases + + align:start position:0% +period doubling in the number of cases + + + align:start position:0% +period doubling in the number of cases +genetic or environment + + align:start position:0% +genetic or environment + + + align:start position:0% +genetic or environment +why + + align:start position:0% + + + + align:start position:0% + +okay so there are three potential what + + align:start position:0% +okay so there are three potential what + + + align:start position:0% +okay so there are three potential what +are the three population genetic + + align:start position:0% +are the three population genetic + + + align:start position:0% +are the three population genetic +mechanisms that + + align:start position:0% +mechanisms that + + + align:start position:0% +mechanisms that +uh something like this could could + + align:start position:0% +uh something like this could could + + + align:start position:0% +uh something like this could could +uh could occur uh a genetic explanation + + align:start position:0% +uh could occur uh a genetic explanation + + + align:start position:0% +uh could occur uh a genetic explanation +genetic explanation + + align:start position:0% +genetic explanation + + + align:start position:0% +genetic explanation +so you you you you you're i'll give you + + align:start position:0% +so you you you you you're i'll give you + + + align:start position:0% +so you you you you you're i'll give you +at least half credit + + align:start position:0% +at least half credit + + + align:start position:0% +at least half credit +but but you're definitely not 100 right + + align:start position:0% +but but you're definitely not 100 right + + + align:start position:0% +but but you're definitely not 100 right +um the first genetic mechanism would be + + align:start position:0% +um the first genetic mechanism would be + + + align:start position:0% +um the first genetic mechanism would be +spontaneous mutation right you had some + + align:start position:0% +spontaneous mutation right you had some + + + align:start position:0% +spontaneous mutation right you had some +spontaneous mutation and + + align:start position:0% +spontaneous mutation and + + + align:start position:0% +spontaneous mutation and +it caused this epidemic of diseases is + + align:start position:0% +it caused this epidemic of diseases is + + + align:start position:0% +it caused this epidemic of diseases is +that possible + + align:start position:0% + + + + align:start position:0% + +you already said no it's not possible + + align:start position:0% +you already said no it's not possible + + + align:start position:0% +you already said no it's not possible +and you're and you're right it's not but + + align:start position:0% +and you're and you're right it's not but + + + align:start position:0% +and you're and you're right it's not but +you have to know what the spontaneous + + align:start position:0% +you have to know what the spontaneous + + + align:start position:0% +you have to know what the spontaneous +mutation rate is which is about + + align:start position:0% +mutation rate is which is about + + + align:start position:0% +mutation rate is which is about +1 times 10 to the minus 8 base pairs per + + align:start position:0% +1 times 10 to the minus 8 base pairs per + + + align:start position:0% +1 times 10 to the minus 8 base pairs per +generation so it's pretty low + + align:start position:0% +generation so it's pretty low + + + align:start position:0% +generation so it's pretty low +you know we're spontaneously mutating + + align:start position:0% +you know we're spontaneously mutating + + + align:start position:0% +you know we're spontaneously mutating +all of the time but we're not + + align:start position:0% +all of the time but we're not + + + align:start position:0% +all of the time but we're not +spontaneously mutating fast enough + + align:start position:0% +spontaneously mutating fast enough + + + align:start position:0% +spontaneously mutating fast enough +to double the number of cases in a + + align:start position:0% +to double the number of cases in a + + + align:start position:0% +to double the number of cases in a +20-year period of time + + align:start position:0% +20-year period of time + + + align:start position:0% +20-year period of time +so + + align:start position:0% +so + + + align:start position:0% +so +what's the second possible genetic + + align:start position:0% +what's the second possible genetic + + + align:start position:0% +what's the second possible genetic +mechanism + + align:start position:0% +mechanism + + + align:start position:0% +mechanism +natural selection right + + align:start position:0% +natural selection right + + + align:start position:0% +natural selection right +so + + align:start position:0% +so + + + align:start position:0% +so +um + + align:start position:0% +um + + + align:start position:0% +um +natural selection gonna do that + + align:start position:0% +natural selection gonna do that + + + align:start position:0% +natural selection gonna do that +well particularly with the disease like + + align:start position:0% +well particularly with the disease like + + + align:start position:0% +well particularly with the disease like +asthma where there's no selection + + align:start position:0% +asthma where there's no selection + + + align:start position:0% +asthma where there's no selection +pressure + + align:start position:0% +pressure + + + align:start position:0% +pressure +in no reproductive advantages or + + align:start position:0% +in no reproductive advantages or + + + align:start position:0% +in no reproductive advantages or +disadvantages right you all know plenty + + align:start position:0% +disadvantages right you all know plenty + + + align:start position:0% +disadvantages right you all know plenty +of people with asthma and they're able + + align:start position:0% +of people with asthma and they're able + + + align:start position:0% +of people with asthma and they're able +to reproduce just like everybody else so + + align:start position:0% +to reproduce just like everybody else so + + + align:start position:0% +to reproduce just like everybody else so +it couldn't be natural selection and + + align:start position:0% +it couldn't be natural selection and + + + align:start position:0% +it couldn't be natural selection and +what's the third population genetic + + align:start position:0% +what's the third population genetic + + + align:start position:0% +what's the third population genetic +mechanism that could uh + + align:start position:0% +mechanism that could uh + + + align:start position:0% +mechanism that could uh +uh + + align:start position:0% +uh + + + align:start position:0% +uh +the third one + + align:start position:0% + + + + align:start position:0% + +genetic drift + + align:start position:0% +genetic drift + + + align:start position:0% +genetic drift +so you know you had some + + align:start position:0% +so you know you had some + + + align:start position:0% +so you know you had some +mutant asthmatic that came into the + + align:start position:0% +mutant asthmatic that came into the + + + align:start position:0% +mutant asthmatic that came into the +american population and over 20 years of + + align:start position:0% +american population and over 20 years of + + + align:start position:0% +american population and over 20 years of +time they + + align:start position:0% +time they + + + align:start position:0% +time they +intermarried with all these other people + + align:start position:0% +intermarried with all these other people + + + align:start position:0% +intermarried with all these other people +and doubled the asthma ring plausible or + + align:start position:0% +and doubled the asthma ring plausible or + + + align:start position:0% +and doubled the asthma ring plausible or +implausible + + align:start position:0% +implausible + + + align:start position:0% +implausible +no can't happen okay so you're right it + + align:start position:0% +no can't happen okay so you're right it + + + align:start position:0% +no can't happen okay so you're right it +can't be genetic + + align:start position:0% +can't be genetic + + + align:start position:0% +can't be genetic +so i i could give you i'd give you half + + align:start position:0% +so i i could give you i'd give you half + + + align:start position:0% +so i i could give you i'd give you half +credit but + + align:start position:0% + + + + align:start position:0% + +what + + align:start position:0% +what + + + align:start position:0% +what +i mean this is most geneticists don't + + align:start position:0% +i mean this is most geneticists don't + + + align:start position:0% +i mean this is most geneticists don't +think like this but they should think + + align:start position:0% +think like this but they should think + + + align:start position:0% +think like this but they should think +like this the reality is is that all of + + align:start position:0% +like this the reality is is that all of + + + align:start position:0% +like this the reality is is that all of +these genes + + align:start position:0% +these genes + + + align:start position:0% +these genes +operate in a developmental and an + + align:start position:0% +operate in a developmental and an + + + align:start position:0% +operate in a developmental and an +environmental context all of your genes + + align:start position:0% +environmental context all of your genes + + + align:start position:0% +environmental context all of your genes +do so the true underlying model for + + align:start position:0% +do so the true underlying model for + + + align:start position:0% +do so the true underlying model for +disease causation is gene by environment + + align:start position:0% +disease causation is gene by environment + + + align:start position:0% +disease causation is gene by environment +interaction so it could very well be + + align:start position:0% +interaction so it could very well be + + + align:start position:0% +interaction so it could very well be +that there was some + + align:start position:0% +that there was some + + + align:start position:0% +that there was some +dramatic change in the environment and + + align:start position:0% +dramatic change in the environment and + + + align:start position:0% +dramatic change in the environment and +now that's interacting with some other + + align:start position:0% +now that's interacting with some other + + + align:start position:0% +now that's interacting with some other +genes that it wasn't they weren't + + align:start position:0% +genes that it wasn't they weren't + + + align:start position:0% +genes that it wasn't they weren't +interacting before with and now you've + + align:start position:0% +interacting before with and now you've + + + align:start position:0% +interacting before with and now you've +got this marked explosion in a number of + + align:start position:0% +got this marked explosion in a number of + + + align:start position:0% +got this marked explosion in a number of +cases and that's almost + + align:start position:0% +cases and that's almost + + + align:start position:0% +cases and that's almost +certainly is the most + + align:start position:0% +certainly is the most + + + align:start position:0% +certainly is the most +comprehensive + + align:start position:0% +comprehensive + + + align:start position:0% +comprehensive +explanation but it would have to devolve + + align:start position:0% +explanation but it would have to devolve + + + align:start position:0% +explanation but it would have to devolve +from some sort of environmental change + + align:start position:0% +from some sort of environmental change + + + align:start position:0% +from some sort of environmental change +rather than some sort of primary change + + align:start position:0% +rather than some sort of primary change + + + align:start position:0% +rather than some sort of primary change +in in the genes but it could easily be + + align:start position:0% +in in the genes but it could easily be + + + align:start position:0% +in in the genes but it could easily be +that there is interaction between + + align:start position:0% +that there is interaction between + + + align:start position:0% +that there is interaction between +whatever the environmental exposure is + + align:start position:0% +whatever the environmental exposure is + + + align:start position:0% +whatever the environmental exposure is +and uh some of the underlying + + align:start position:0% +and uh some of the underlying + + + align:start position:0% +and uh some of the underlying +polymorphisms that may be disease + + align:start position:0% +polymorphisms that may be disease + + + align:start position:0% +polymorphisms that may be disease +related that are different now than they + + align:start position:0% +related that are different now than they + + + align:start position:0% +related that are different now than they +were + + align:start position:0% +were + + + align:start position:0% +were +back here when the + + align:start position:0% +back here when the + + + align:start position:0% +back here when the +disease rate was a lot lower + + align:start position:0% +disease rate was a lot lower + + + align:start position:0% +disease rate was a lot lower +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so big health problem i don't want to + + align:start position:0% +so big health problem i don't want to + + + align:start position:0% +so big health problem i don't want to +dwell on this but the uh uh because + + align:start position:0% +dwell on this but the uh uh because + + + align:start position:0% +dwell on this but the uh uh because +that's not the purpose of this course + + align:start position:0% +that's not the purpose of this course + + + align:start position:0% +that's not the purpose of this course +but + + align:start position:0% +but + + + align:start position:0% +but +uh um + + align:start position:0% +uh um + + + align:start position:0% +uh um +all this means is that people will give + + align:start position:0% +all this means is that people will give + + + align:start position:0% +all this means is that people will give +you money to study this and they you + + align:start position:0% +you money to study this and they you + + + align:start position:0% +you money to study this and they you +know they weren't so keen on doing that + + align:start position:0% +know they weren't so keen on doing that + + + align:start position:0% +know they weren't so keen on doing that +um 20 or 30 years ago + + align:start position:0% +um 20 or 30 years ago + + + align:start position:0% +um 20 or 30 years ago +the other important point is this + + align:start position:0% +the other important point is this + + + align:start position:0% +the other important point is this +disease is a disease of children + + align:start position:0% +disease is a disease of children + + + align:start position:0% +disease is a disease of children +so you're going to think about it i + + align:start position:0% +so you're going to think about it i + + + align:start position:0% +so you're going to think about it i +usually tell people 90 this is data + + align:start position:0% +usually tell people 90 this is data + + + align:start position:0% +usually tell people 90 this is data +looking at the age of onset in a closed + + align:start position:0% +looking at the age of onset in a closed + + + align:start position:0% +looking at the age of onset in a closed +population in olmsted county what's the + + align:start position:0% +population in olmsted county what's the + + + align:start position:0% +population in olmsted county what's the +famous + + align:start position:0% +famous + + + align:start position:0% +famous +medical center in olmsted county + + align:start position:0% +medical center in olmsted county + + + align:start position:0% +medical center in olmsted county +minnesota + + align:start position:0% + + + + align:start position:0% + +you weren't supposed to answer that + + align:start position:0% +you weren't supposed to answer that + + + align:start position:0% +you weren't supposed to answer that +there was the answer + + align:start position:0% + + + + align:start position:0% + +mayo clinic mayo clinic so mayo clinic + + align:start position:0% +mayo clinic mayo clinic so mayo clinic + + + align:start position:0% +mayo clinic mayo clinic so mayo clinic +is + + align:start position:0% +is + + + align:start position:0% +is +everybody in olmsted county + + align:start position:0% +everybody in olmsted county + + + align:start position:0% +everybody in olmsted county +goes to the mayo clinic now + + align:start position:0% +goes to the mayo clinic now + + + align:start position:0% +goes to the mayo clinic now +you know + + align:start position:0% +you know + + + align:start position:0% +you know +saudi princes and cheeks and + + align:start position:0% +saudi princes and cheeks and + + + align:start position:0% +saudi princes and cheeks and +famous people from all over the world + + align:start position:0% +famous people from all over the world + + + align:start position:0% +famous people from all over the world +and the uh um + + align:start position:0% +and the uh um + + + align:start position:0% +and the uh um +uh um + + align:start position:0% +uh um + + + align:start position:0% +uh um +who was the king of jordan king + + align:start position:0% +who was the king of jordan king + + + align:start position:0% +who was the king of jordan king +saying he you know he went there first + + align:start position:0% +saying he you know he went there first + + + align:start position:0% +saying he you know he went there first +he went there for his uh + + align:start position:0% +he went there for his uh + + + align:start position:0% +he went there for his uh +yeah so zach's mother another famous + + align:start position:0% +yeah so zach's mother another famous + + + align:start position:0% +yeah so zach's mother another famous +person went to the mayo clinic so they + + align:start position:0% +person went to the mayo clinic so they + + + align:start position:0% +person went to the mayo clinic so they +get a lot of people from outside but + + align:start position:0% +get a lot of people from outside but + + + align:start position:0% +get a lot of people from outside but +this data is based on the people who + + align:start position:0% +this data is based on the people who + + + align:start position:0% +this data is based on the people who +live in olmsted county now if you live + + align:start position:0% +live in olmsted county now if you live + + + align:start position:0% +live in olmsted county now if you live +in olmsted county you don't go anywhere + + align:start position:0% +in olmsted county you don't go anywhere + + + align:start position:0% +in olmsted county you don't go anywhere +okay you just sit right there and you + + align:start position:0% +okay you just sit right there and you + + + align:start position:0% +okay you just sit right there and you +stay there so + + align:start position:0% +stay there so + + + align:start position:0% +stay there so +this was a fairly stable population and + + align:start position:0% +this was a fairly stable population and + + + align:start position:0% +this was a fairly stable population and +they were able to capture all of the + + align:start position:0% +they were able to capture all of the + + + align:start position:0% +they were able to capture all of the +incident asthma cases and document them + + align:start position:0% +incident asthma cases and document them + + + align:start position:0% +incident asthma cases and document them +because they were all + + align:start position:0% + + + + align:start position:0% + +going to the mayo medical center and + + align:start position:0% +going to the mayo medical center and + + + align:start position:0% +going to the mayo medical center and +they had their chart records so 90 of + + align:start position:0% +they had their chart records so 90 of + + + align:start position:0% +they had their chart records so 90 of +all of the people who were diagnosed in + + align:start position:0% +all of the people who were diagnosed in + + + align:start position:0% +all of the people who were diagnosed in +as asthmatic in olmsted county were + + align:start position:0% +as asthmatic in olmsted county were + + + align:start position:0% +as asthmatic in olmsted county were +diagnosed before the age of six + + align:start position:0% +diagnosed before the age of six + + + align:start position:0% +diagnosed before the age of six +so this is a very very important point + + align:start position:0% +so this is a very very important point + + + align:start position:0% +so this is a very very important point +so this is the + + align:start position:0% +so this is the + + + align:start position:0% +so this is the +opposite of alzheimer's disease right + + align:start position:0% +opposite of alzheimer's disease right + + + align:start position:0% +opposite of alzheimer's disease right +because + + align:start position:0% +because + + + align:start position:0% +because +if you think about genetics this is + + align:start position:0% +if you think about genetics this is + + + align:start position:0% +if you think about genetics this is +great for geneticists because i only + + align:start position:0% +great for geneticists because i only + + + align:start position:0% +great for geneticists because i only +have to wait + + align:start position:0% +have to wait + + + align:start position:0% +have to wait +six years from the time that the kid is + + align:start position:0% +six years from the time that the kid is + + + align:start position:0% +six years from the time that the kid is +born and i'm going to know whether + + align:start position:0% +born and i'm going to know whether + + + align:start position:0% +born and i'm going to know whether +they've got the disease phenotype or not + + align:start position:0% +they've got the disease phenotype or not + + + align:start position:0% +they've got the disease phenotype or not +if i was waiting for alzheimer's cases + + align:start position:0% +if i was waiting for alzheimer's cases + + + align:start position:0% +if i was waiting for alzheimer's cases +it would be + + align:start position:0% +it would be + + + align:start position:0% +it would be +waiting for godot i'd be waiting a long + + align:start position:0% +waiting for godot i'd be waiting a long + + + align:start position:0% +waiting for godot i'd be waiting a long +time before + + align:start position:0% +time before + + + align:start position:0% +time before +um + + align:start position:0% +um + + + align:start position:0% +um +i'd get my cases now there's ways around + + align:start position:0% +i'd get my cases now there's ways around + + + align:start position:0% +i'd get my cases now there's ways around +that for the old people right and what + + align:start position:0% +that for the old people right and what + + + align:start position:0% +that for the old people right and what +did geneticists do how did they find the + + align:start position:0% +did geneticists do how did they find the + + + align:start position:0% +did geneticists do how did they find the +bronco one gene what did what did they + + align:start position:0% +bronco one gene what did what did they + + + align:start position:0% +bronco one gene what did what did they +do to to enhance the the probability + + align:start position:0% +do to to enhance the the probability + + + align:start position:0% +do to to enhance the the probability +that you would find if you're looking at + + align:start position:0% +that you would find if you're looking at + + + align:start position:0% +that you would find if you're looking at +people older older people + + align:start position:0% +people older older people + + + align:start position:0% +people older older people +how do you + + align:start position:0% +how do you + + + align:start position:0% +how do you +enrich for a genetic cause of a disease + + align:start position:0% +enrich for a genetic cause of a disease + + + align:start position:0% +enrich for a genetic cause of a disease +what do you do + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +education doesn't have anything to do + + align:start position:0% +education doesn't have anything to do + + + align:start position:0% +education doesn't have anything to do +with i'm afraid + + align:start position:0% +with i'm afraid + + + align:start position:0% +with i'm afraid +no you just what characteristic of the + + align:start position:0% +no you just what characteristic of the + + + align:start position:0% +no you just what characteristic of the +cases would make you think it's more + + align:start position:0% +cases would make you think it's more + + + align:start position:0% +cases would make you think it's more +likely to be genetic + + align:start position:0% + + + + align:start position:0% + +what family history + + align:start position:0% +what family history + + + align:start position:0% +what family history +family family history but what + + align:start position:0% +family family history but what + + + align:start position:0% +family family history but what +specifically a + + align:start position:0% +specifically a + + + align:start position:0% +specifically a +family history age of onset right you're + + align:start position:0% +family history age of onset right you're + + + align:start position:0% +family history age of onset right you're +looking for genetic causes of heart + + align:start position:0% +looking for genetic causes of heart + + + align:start position:0% +looking for genetic causes of heart +attacks you're going to take the people + + align:start position:0% +attacks you're going to take the people + + + align:start position:0% +attacks you're going to take the people +that have heart attacks when they're + + align:start position:0% +that have heart attacks when they're + + + align:start position:0% +that have heart attacks when they're +aged 50. so ed silverman who's the world + + align:start position:0% +aged 50. so ed silverman who's the world + + + align:start position:0% +aged 50. so ed silverman who's the world +leader in copd genetics in my laboratory + + align:start position:0% +leader in copd genetics in my laboratory + + + align:start position:0% +leader in copd genetics in my laboratory +is looking for early onset copd cases so + + align:start position:0% +is looking for early onset copd cases so + + + align:start position:0% +is looking for early onset copd cases so +he gets cases where the age of onset is + + align:start position:0% +he gets cases where the age of onset is + + + align:start position:0% +he gets cases where the age of onset is +younger than the age of 52. + + align:start position:0% +younger than the age of 52. + + + align:start position:0% +younger than the age of 52. +so that's young + + align:start position:0% +so that's young + + + align:start position:0% +so that's young +so if you're looking at alzheimer's + + align:start position:0% +so if you're looking at alzheimer's + + + align:start position:0% +so if you're looking at alzheimer's +cases you'd say well we want all of the + + align:start position:0% +cases you'd say well we want all of the + + + align:start position:0% +cases you'd say well we want all of the +cases of alzheimer's people before the + + align:start position:0% +cases of alzheimer's people before the + + + align:start position:0% +cases of alzheimer's people before the +age of 60. this is how mary claire king + + align:start position:0% +age of 60. this is how mary claire king + + + align:start position:0% +age of 60. this is how mary claire king +found barack one she looked at all of + + align:start position:0% +found barack one she looked at all of + + + align:start position:0% +found barack one she looked at all of +the early onset breast cancer cases + + align:start position:0% +the early onset breast cancer cases + + + align:start position:0% +the early onset breast cancer cases +people who got breast cancer in their + + align:start position:0% +people who got breast cancer in their + + + align:start position:0% +people who got breast cancer in their +20s their 30s their 40s + + align:start position:0% +20s their 30s their 40s + + + align:start position:0% +20s their 30s their 40s +instead of looking at older + + align:start position:0% +instead of looking at older + + + align:start position:0% +instead of looking at older +postmenopausal women which is almost + + align:start position:0% +postmenopausal women which is almost + + + align:start position:0% +postmenopausal women which is almost +certainly another disease okay so if + + align:start position:0% +certainly another disease okay so if + + + align:start position:0% +certainly another disease okay so if +you're looking at old people one of the + + align:start position:0% +you're looking at old people one of the + + + align:start position:0% +you're looking at old people one of the +clever ways that geneticists enrich for + + align:start position:0% +clever ways that geneticists enrich for + + + align:start position:0% +clever ways that geneticists enrich for +uh uh um genetic susceptibility is by + + align:start position:0% +uh uh um genetic susceptibility is by + + + align:start position:0% +uh uh um genetic susceptibility is by +looking at early age of onset + + align:start position:0% +looking at early age of onset + + + align:start position:0% +looking at early age of onset +okay + + align:start position:0% +okay + + + align:start position:0% +okay +of selecting potentially + + align:start position:0% +of selecting potentially + + + align:start position:0% +of selecting potentially +a special case of a particular disease + + align:start position:0% +a special case of a particular disease + + + align:start position:0% +a special case of a particular disease +absolutely right it's it's it's a little + + align:start position:0% +absolutely right it's it's it's a little + + + align:start position:0% +absolutely right it's it's it's a little +bit like in some perverse kind of way + + align:start position:0% +bit like in some perverse kind of way + + + align:start position:0% +bit like in some perverse kind of way +it's a little bit like the genetic + + align:start position:0% +it's a little bit like the genetic + + + align:start position:0% +it's a little bit like the genetic +isolate you might find a gene that is + + align:start position:0% +isolate you might find a gene that is + + + align:start position:0% +isolate you might find a gene that is +specific for + + align:start position:0% +specific for + + + align:start position:0% +specific for +that particular type + + align:start position:0% +that particular type + + + align:start position:0% +that particular type +of early onset disease so you find a + + align:start position:0% +of early onset disease so you find a + + + align:start position:0% +of early onset disease so you find a +gene for early onset alzheimer's but not + + align:start position:0% +gene for early onset alzheimer's but not + + + align:start position:0% +gene for early onset alzheimer's but not +for garden variety + + align:start position:0% +for garden variety + + + align:start position:0% +for garden variety +old age alzheimer's that occurs in + + align:start position:0% +old age alzheimer's that occurs in + + + align:start position:0% +old age alzheimer's that occurs in +uh um + + align:start position:0% +uh um + + + align:start position:0% +uh um +virtually everybody by the time they're + + align:start position:0% +virtually everybody by the time they're + + + align:start position:0% +virtually everybody by the time they're +90. + + align:start position:0% +90. + + + align:start position:0% +90. +um so + + align:start position:0% +um so + + + align:start position:0% +um so +you you're you're right but it's a it's + + align:start position:0% +you you're you're right but it's a it's + + + align:start position:0% +you you're you're right but it's a it's +a + + align:start position:0% +a + + + align:start position:0% +a +uh you know we're still + + align:start position:0% +uh you know we're still + + + align:start position:0% +uh you know we're still +and i think what geneticists would say + + align:start position:0% +and i think what geneticists would say + + + align:start position:0% +and i think what geneticists would say +the early stages of this and because + + align:start position:0% +the early stages of this and because + + + align:start position:0% +the early stages of this and because +we're still in the early stages most of + + align:start position:0% +we're still in the early stages most of + + + align:start position:0% +we're still in the early stages most of +us would be happy if we found any gene + + align:start position:0% +us would be happy if we found any gene + + + align:start position:0% +us would be happy if we found any gene +so + + align:start position:0% +so + + + align:start position:0% +so +you know you're going to be in science + + align:start position:0% +you know you're going to be in science + + + align:start position:0% +you know you're going to be in science +if you find that early onset gene and + + align:start position:0% +if you find that early onset gene and + + + align:start position:0% +if you find that early onset gene and +nobody's going to be criticizing you + + align:start position:0% +nobody's going to be criticizing you + + + align:start position:0% +nobody's going to be criticizing you +because it's not the gene for all + + align:start position:0% +because it's not the gene for all + + + align:start position:0% +because it's not the gene for all +uh breast cancer or all alzheimer's + + align:start position:0% +uh breast cancer or all alzheimer's + + + align:start position:0% +uh breast cancer or all alzheimer's +we'll get another example hanging fruit + + align:start position:0% +we'll get another example hanging fruit + + + align:start position:0% +we'll get another example hanging fruit +exactly + + align:start position:0% + + + + align:start position:0% + +so a little bit more about the disease + + align:start position:0% +so a little bit more about the disease + + + align:start position:0% +so a little bit more about the disease +most of the kids are allergic + + align:start position:0% +most of the kids are allergic + + + align:start position:0% +most of the kids are allergic +allergy is probably the big reason why + + align:start position:0% +allergy is probably the big reason why + + + align:start position:0% +allergy is probably the big reason why +the asthma epidemic occurred + + align:start position:0% +the asthma epidemic occurred + + + align:start position:0% +the asthma epidemic occurred +and that means that um + + align:start position:0% +and that means that um + + + align:start position:0% +and that means that um +you know there's + + align:start position:0% +you know there's + + + align:start position:0% +you know there's +they have this particular type of an + + align:start position:0% +they have this particular type of an + + + align:start position:0% +they have this particular type of an +inflammatory process where antigen + + align:start position:0% +inflammatory process where antigen + + + align:start position:0% +inflammatory process where antigen +presented to dendritic cells in the + + align:start position:0% +presented to dendritic cells in the + + + align:start position:0% +presented to dendritic cells in the +airways activate these uh cd4 positive t + + align:start position:0% +airways activate these uh cd4 positive t + + + align:start position:0% +airways activate these uh cd4 positive t +lymphocytes which then elaborate this + + align:start position:0% +lymphocytes which then elaborate this + + + align:start position:0% +lymphocytes which then elaborate this +series of inflammatory cytokines which + + align:start position:0% +series of inflammatory cytokines which + + + align:start position:0% +series of inflammatory cytokines which +go to these inflammatory cells which + + align:start position:0% +go to these inflammatory cells which + + + align:start position:0% +go to these inflammatory cells which +then infiltrate the airways and set up + + align:start position:0% +then infiltrate the airways and set up + + + align:start position:0% +then infiltrate the airways and set up +an inflammatory reaction with + + align:start position:0% +an inflammatory reaction with + + + align:start position:0% +an inflammatory reaction with +coughing wheezing airways responsiveness + + align:start position:0% +coughing wheezing airways responsiveness + + + align:start position:0% +coughing wheezing airways responsiveness +etc etc etc + + align:start position:0% +etc etc etc + + + align:start position:0% +etc etc etc +this is all well known but it does sort + + align:start position:0% +this is all well known but it does sort + + + align:start position:0% +this is all well known but it does sort +of suggest a whole host of other + + align:start position:0% +of suggest a whole host of other + + + align:start position:0% +of suggest a whole host of other +potential phenotypes that you could + + align:start position:0% +potential phenotypes that you could + + + align:start position:0% +potential phenotypes that you could +potentially look at + + align:start position:0% +potentially look at + + + align:start position:0% +potentially look at +and it also gets at this concept of + + align:start position:0% +and it also gets at this concept of + + + align:start position:0% +and it also gets at this concept of +ontogeny of the immune system where + + align:start position:0% +ontogeny of the immune system where + + + align:start position:0% +ontogeny of the immune system where +you know uh t null cells + + align:start position:0% +you know uh t null cells + + + align:start position:0% +you know uh t null cells +at some point differentiate into these + + align:start position:0% +at some point differentiate into these + + + align:start position:0% +at some point differentiate into these +th1 and th2 cells which are determined + + align:start position:0% +th1 and th2 cells which are determined + + + align:start position:0% +th1 and th2 cells which are determined +their phenotype is determined by which + + align:start position:0% +their phenotype is determined by which + + + align:start position:0% +their phenotype is determined by which +cytokines they actually elaborate and + + align:start position:0% +cytokines they actually elaborate and + + + align:start position:0% +cytokines they actually elaborate and +i've got a question mark here but + + align:start position:0% +i've got a question mark here but + + + align:start position:0% +i've got a question mark here but +actually this particular step which is + + align:start position:0% +actually this particular step which is + + + align:start position:0% +actually this particular step which is +sort of the + + align:start position:0% +sort of the + + + align:start position:0% +sort of the +crosstalk and interaction between these + + align:start position:0% +crosstalk and interaction between these + + + align:start position:0% +crosstalk and interaction between these +two + + align:start position:0% +two + + + align:start position:0% +two +types of cells are controlled by two + + align:start position:0% +types of cells are controlled by two + + + align:start position:0% +types of cells are controlled by two +specific uh uh + + align:start position:0% +specific uh uh + + + align:start position:0% +specific uh uh +genes that elaborate cytokines il-10 and + + align:start position:0% +genes that elaborate cytokines il-10 and + + + align:start position:0% +genes that elaborate cytokines il-10 and +tgf beta and + + align:start position:0% +tgf beta and + + + align:start position:0% +tgf beta and +we've genotyped both of those genes + + align:start position:0% +we've genotyped both of those genes + + + align:start position:0% +we've genotyped both of those genes +in in asthma and copd and + + align:start position:0% +in in asthma and copd and + + + align:start position:0% +in in asthma and copd and +they're they're important in both + + align:start position:0% +they're they're important in both + + + align:start position:0% +they're they're important in both +diseases um now it's important for you + + align:start position:0% +diseases um now it's important for you + + + align:start position:0% +diseases um now it's important for you +to understand that i sort of skewed + + align:start position:0% +to understand that i sort of skewed + + + align:start position:0% +to understand that i sort of skewed +things a little bit because i told you + + align:start position:0% +things a little bit because i told you + + + align:start position:0% +things a little bit because i told you +that + + align:start position:0% +that + + + align:start position:0% +that +asthma is a th2 disease and teach two + + align:start position:0% +asthma is a th2 disease and teach two + + + align:start position:0% +asthma is a th2 disease and teach two +diseases have + + align:start position:0% +diseases have + + + align:start position:0% +diseases have +increased you know there's this increase + + align:start position:0% +increased you know there's this increase + + + align:start position:0% +increased you know there's this increase +in allergic rhinitis food allergy asthma + + align:start position:0% +in allergic rhinitis food allergy asthma + + + align:start position:0% +in allergic rhinitis food allergy asthma +etc etc this novel gene that i was + + align:start position:0% +etc etc this novel gene that i was + + + align:start position:0% +etc etc this novel gene that i was +telling you about just a few minutes ago + + align:start position:0% +telling you about just a few minutes ago + + + align:start position:0% +telling you about just a few minutes ago +it's going to come out in science on + + align:start position:0% +it's going to come out in science on + + + align:start position:0% +it's going to come out in science on +friday that gene is expressed in the + + align:start position:0% +friday that gene is expressed in the + + + align:start position:0% +friday that gene is expressed in the +skin and in + + align:start position:0% +skin and in + + + align:start position:0% +skin and in +gut epithelium and in airway epithelium + + align:start position:0% +gut epithelium and in airway epithelium + + + align:start position:0% +gut epithelium and in airway epithelium +suggesting that + + align:start position:0% +suggesting that + + + align:start position:0% +suggesting that +may be important in all these different + + align:start position:0% +may be important in all these different + + + align:start position:0% +may be important in all these different +types of allergic diseases which again + + align:start position:0% +types of allergic diseases which again + + + align:start position:0% +types of allergic diseases which again +has heightened people's interest in the + + align:start position:0% +has heightened people's interest in the + + + align:start position:0% +has heightened people's interest in the +gene + + align:start position:0% +gene + + + align:start position:0% +gene +and its potential uh um + + align:start position:0% +and its potential uh um + + + align:start position:0% +and its potential uh um +importance + + align:start position:0% +importance + + + align:start position:0% +importance +but um + + align:start position:0% +but um + + + align:start position:0% +but um +it's also important to recognize that + + align:start position:0% +it's also important to recognize that + + + align:start position:0% +it's also important to recognize that +th1 diseases have also increased so give + + align:start position:0% +th1 diseases have also increased so give + + + align:start position:0% +th1 diseases have also increased so give +me some example of some th1 diseases + + align:start position:0% +me some example of some th1 diseases + + + align:start position:0% +me some example of some th1 diseases +so the epidemiology and the reason i'm + + align:start position:0% +so the epidemiology and the reason i'm + + + align:start position:0% +so the epidemiology and the reason i'm +bringing this up is is that people most + + align:start position:0% +bringing this up is is that people most + + + align:start position:0% +bringing this up is is that people most +of the immunology community is focused + + align:start position:0% +of the immunology community is focused + + + align:start position:0% +of the immunology community is focused +on this is why it's important if you're + + align:start position:0% +on this is why it's important if you're + + + align:start position:0% +on this is why it's important if you're +going to be a good geneticist you got to + + align:start position:0% +going to be a good geneticist you got to + + + align:start position:0% +going to be a good geneticist you got to +really know your disease you can't just + + align:start position:0% +really know your disease you can't just + + + align:start position:0% +really know your disease you can't just +sort of wave your hand at it and say oh + + align:start position:0% +sort of wave your hand at it and say oh + + + align:start position:0% +sort of wave your hand at it and say oh +and i think that the age of the + + align:start position:0% +and i think that the age of the + + + align:start position:0% +and i think that the age of the +generalist geneticist the geneticist + + align:start position:0% +generalist geneticist the geneticist + + + align:start position:0% +generalist geneticist the geneticist +that sort of oh you know i'm going to + + align:start position:0% +that sort of oh you know i'm going to + + + align:start position:0% +that sort of oh you know i'm going to +study this disease and i'm going to + + align:start position:0% +study this disease and i'm going to + + + align:start position:0% +study this disease and i'm going to +study that disease + + align:start position:0% +study that disease + + + align:start position:0% +study that disease +not with complex traits that's not going + + align:start position:0% +not with complex traits that's not going + + + align:start position:0% +not with complex traits that's not going +to work you're going to have to really + + align:start position:0% +to work you're going to have to really + + + align:start position:0% +to work you're going to have to really +know your disease because you have to + + align:start position:0% +know your disease because you have to + + + align:start position:0% +know your disease because you have to +know the environment you're gonna have + + align:start position:0% +know the environment you're gonna have + + + align:start position:0% +know the environment you're gonna have +to know the + + align:start position:0% +to know the + + + align:start position:0% +to know the +natural history you're gonna have to + + align:start position:0% +natural history you're gonna have to + + + align:start position:0% +natural history you're gonna have to +know the intermediate phenotypes and you + + align:start position:0% +know the intermediate phenotypes and you + + + align:start position:0% +know the intermediate phenotypes and you +have to really understand + + align:start position:0% +have to really understand + + + align:start position:0% +have to really understand +the biology + + align:start position:0% +the biology + + + align:start position:0% +the biology +uh uh as well the point here is is these + + align:start position:0% +uh uh as well the point here is is these + + + align:start position:0% +uh uh as well the point here is is these +th1 disease give me an example of a th1 + + align:start position:0% +th1 disease give me an example of a th1 + + + align:start position:0% +th1 disease give me an example of a th1 +disease + + align:start position:0% +disease + + + align:start position:0% +disease +well i'm thinking about that um + + align:start position:0% +well i'm thinking about that um + + + align:start position:0% +well i'm thinking about that um +can you um tell me + + align:start position:0% +can you um tell me + + + align:start position:0% +can you um tell me +the autoimmune diseases like + + align:start position:0% +the autoimmune diseases like + + + align:start position:0% +the autoimmune diseases like +inflammatory bowel disease what are they + + align:start position:0% +inflammatory bowel disease what are they + + + align:start position:0% +inflammatory bowel disease what are they +they are th1 so crohn's disease + + align:start position:0% +they are th1 so crohn's disease + + + align:start position:0% +they are th1 so crohn's disease +th1 disease + + align:start position:0% +th1 disease + + + align:start position:0% +th1 disease +juvenile rheumatoid arthritis th1 + + align:start position:0% +juvenile rheumatoid arthritis th1 + + + align:start position:0% +juvenile rheumatoid arthritis th1 +disease + + align:start position:0% + + + + align:start position:0% + +psoriasis th1 disease + + align:start position:0% + + + + align:start position:0% + +juvenile diabetes t1 disease + + align:start position:0% +juvenile diabetes t1 disease + + + align:start position:0% +juvenile diabetes t1 disease +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and + + align:start position:0% +and + + + align:start position:0% +and +the reason so if the prevalence of these + + align:start position:0% +the reason so if the prevalence of these + + + align:start position:0% +the reason so if the prevalence of these +has gone up and the prevalence of the + + align:start position:0% +has gone up and the prevalence of the + + + align:start position:0% +has gone up and the prevalence of the +these has gone up people are thinking + + align:start position:0% +these has gone up people are thinking + + + align:start position:0% +these has gone up people are thinking +that there's something going on + + align:start position:0% +that there's something going on + + + align:start position:0% +that there's something going on +further up + + align:start position:0% +further up + + + align:start position:0% +further up +here that + + align:start position:0% +here that + + + align:start position:0% +here that +has to do with t reg cells + + align:start position:0% +has to do with t reg cells + + + align:start position:0% +has to do with t reg cells +cells that regulate t null cells in + + align:start position:0% +cells that regulate t null cells in + + + align:start position:0% +cells that regulate t null cells in +terms of their differentiation because + + align:start position:0% +terms of their differentiation because + + + align:start position:0% +terms of their differentiation because +it can't be just at this level that the + + align:start position:0% +it can't be just at this level that the + + + align:start position:0% +it can't be just at this level that the +immunologic defect is so + + align:start position:0% +immunologic defect is so + + + align:start position:0% +immunologic defect is so +it raises the possibility that there are + + align:start position:0% +it raises the possibility that there are + + + align:start position:0% +it raises the possibility that there are +genes uh a fox p3 + + align:start position:0% +genes uh a fox p3 + + + align:start position:0% +genes uh a fox p3 +uh + + align:start position:0% +uh + + + align:start position:0% +uh +getter + + align:start position:0% +getter + + + align:start position:0% +getter +t-bat a whole bunch of other genes that + + align:start position:0% +t-bat a whole bunch of other genes that + + + align:start position:0% +t-bat a whole bunch of other genes that +are + + align:start position:0% +are + + + align:start position:0% +are +proximal to the th1 th2 cd4 lymphocyte + + align:start position:0% +proximal to the th1 th2 cd4 lymphocyte + + + align:start position:0% +proximal to the th1 th2 cd4 lymphocyte +that may be important in all of these + + align:start position:0% + + + + align:start position:0% + +immune diseases and people are just now + + align:start position:0% +immune diseases and people are just now + + + align:start position:0% +immune diseases and people are just now +starting to look at + + align:start position:0% +starting to look at + + + align:start position:0% +starting to look at +at that and obviously the environmental + + align:start position:0% +at that and obviously the environmental + + + align:start position:0% +at that and obviously the environmental +and genetic factors that influence + + align:start position:0% +and genetic factors that influence + + + align:start position:0% +and genetic factors that influence +the differentiation of the immune system + + align:start position:0% +the differentiation of the immune system + + + align:start position:0% +the differentiation of the immune system +or + + align:start position:0% +or + + + align:start position:0% +or +you know how do people actually tolerize + + align:start position:0% +you know how do people actually tolerize + + + align:start position:0% +you know how do people actually tolerize +the foreign antigen + + align:start position:0% +the foreign antigen + + + align:start position:0% +the foreign antigen +that's the kind of really simple + + align:start position:0% +that's the kind of really simple + + + align:start position:0% +that's the kind of really simple +complicated question that if you could + + align:start position:0% +complicated question that if you could + + + align:start position:0% +complicated question that if you could +figure out an answer that you win a + + align:start position:0% +figure out an answer that you win a + + + align:start position:0% +figure out an answer that you win a +nobel prize + + align:start position:0% +nobel prize + + + align:start position:0% +nobel prize +so that's what my laboratory is starting + + align:start position:0% +so that's what my laboratory is starting + + + align:start position:0% +so that's what my laboratory is starting +to work on + + align:start position:0% +to work on + + + align:start position:0% +to work on +um so this is just to show you + + align:start position:0% +um so this is just to show you + + + align:start position:0% +um so this is just to show you +again what i've already told you that + + align:start position:0% +again what i've already told you that + + + align:start position:0% +again what i've already told you that +there are a bunch of + + align:start position:0% +there are a bunch of + + + align:start position:0% +there are a bunch of +factors mostly bacteria and viruses and + + align:start position:0% +factors mostly bacteria and viruses and + + + align:start position:0% +factors mostly bacteria and viruses and +parasites + + align:start position:0% +parasites + + + align:start position:0% +parasites +that influence this teach one teach to + + align:start position:0% +that influence this teach one teach to + + + align:start position:0% +that influence this teach one teach to +differentiation + + align:start position:0% +differentiation + + + align:start position:0% +differentiation +and uh um environmental factors that + + align:start position:0% +and uh um environmental factors that + + + align:start position:0% +and uh um environmental factors that +influence those things are presumed to + + align:start position:0% +influence those things are presumed to + + + align:start position:0% +influence those things are presumed to +be important and one would want to know + + align:start position:0% +be important and one would want to know + + + align:start position:0% +be important and one would want to know +both the genes and the environmental + + align:start position:0% +both the genes and the environmental + + + align:start position:0% +both the genes and the environmental +factors that are involved in in this + + align:start position:0% +factors that are involved in in this + + + align:start position:0% +factors that are involved in in this +particular disease there happen to be a + + align:start position:0% +particular disease there happen to be a + + + align:start position:0% +particular disease there happen to be a +whole host of + + align:start position:0% +whole host of + + + align:start position:0% +whole host of +environmental factors that are + + align:start position:0% +environmental factors that are + + + align:start position:0% +environmental factors that are +correlates + + align:start position:0% +correlates + + + align:start position:0% +correlates +of those sorts of changes and i've + + align:start position:0% +of those sorts of changes and i've + + + align:start position:0% +of those sorts of changes and i've +listed a bunch of them + + align:start position:0% +listed a bunch of them + + + align:start position:0% +listed a bunch of them +here + + align:start position:0% +here + + + align:start position:0% +here +we got very interested in this when we + + align:start position:0% +we got very interested in this when we + + + align:start position:0% +we got very interested in this when we +went to china in 1996 to do an asthma + + align:start position:0% +went to china in 1996 to do an asthma + + + align:start position:0% +went to china in 1996 to do an asthma +genetic study and i noticed how + + align:start position:0% +genetic study and i noticed how + + + align:start position:0% +genetic study and i noticed how +different the environment was uh there + + align:start position:0% +different the environment was uh there + + + align:start position:0% +different the environment was uh there +and + + align:start position:0% +and + + + align:start position:0% +and +you know this + + align:start position:0% +you know this + + + align:start position:0% +you know this +left-hand + + align:start position:0% +left-hand + + + align:start position:0% +left-hand +category would sort of summarize what + + align:start position:0% +category would sort of summarize what + + + align:start position:0% +category would sort of summarize what +you would see if you were standing in + + align:start position:0% +you would see if you were standing in + + + align:start position:0% +you would see if you were standing in +rural china which you would see in terms + + align:start position:0% +rural china which you would see in terms + + + align:start position:0% +rural china which you would see in terms +of the + + align:start position:0% +of the + + + align:start position:0% +of the +environmental exposures + + align:start position:0% +environmental exposures + + + align:start position:0% +environmental exposures +very very low asthma rates in the rural + + align:start position:0% +very very low asthma rates in the rural + + + align:start position:0% +very very low asthma rates in the rural +china it's about one percent + + align:start position:0% +china it's about one percent + + + align:start position:0% +china it's about one percent +energy is a progressive increase in + + align:start position:0% +energy is a progressive increase in + + + align:start position:0% +energy is a progressive increase in +gradient in terms of disease prevalence + + align:start position:0% +gradient in terms of disease prevalence + + + align:start position:0% +gradient in terms of disease prevalence +as you march towards beijing or shanghai + + align:start position:0% +as you march towards beijing or shanghai + + + align:start position:0% +as you march towards beijing or shanghai +you know much much higher + + align:start position:0% +you know much much higher + + + align:start position:0% +you know much much higher +higher rates let me ask + + align:start position:0% +higher rates let me ask + + + align:start position:0% +higher rates let me ask +some questions + + align:start position:0% +some questions + + + align:start position:0% +some questions +is it not actually + + align:start position:0% +is it not actually + + + align:start position:0% +is it not actually +wrong that + + align:start position:0% +wrong that + + + align:start position:0% +wrong that +chinese populations i thought the + + align:start position:0% +chinese populations i thought the + + + align:start position:0% +chinese populations i thought the +families were limited no + + align:start position:0% +families were limited no + + + align:start position:0% +families were limited no +see that's again + + align:start position:0% +see that's again + + + align:start position:0% +see that's again +a little bit of knowledge is a bad thing + + align:start position:0% +a little bit of knowledge is a bad thing + + + align:start position:0% +a little bit of knowledge is a bad thing +if you get into rural china + + align:start position:0% +if you get into rural china + + + align:start position:0% +if you get into rural china +actually where where + + align:start position:0% +actually where where + + + align:start position:0% +actually where where +uh farming is what everybody does + + align:start position:0% +uh farming is what everybody does + + + align:start position:0% +uh farming is what everybody does +um + + align:start position:0% +um + + + align:start position:0% +um +although the central government would + + align:start position:0% +although the central government would + + + align:start position:0% +although the central government would +say you could there's a there's a + + align:start position:0% +say you could there's a there's a + + + align:start position:0% +say you could there's a there's a +a a two-child policy or a one-child + + align:start position:0% +a a two-child policy or a one-child + + + align:start position:0% +a a two-child policy or a one-child +policy uh you know in rural china they + + align:start position:0% +policy uh you know in rural china they + + + align:start position:0% +policy uh you know in rural china they +just they have as many children as they + + align:start position:0% +just they have as many children as they + + + align:start position:0% +just they have as many children as they +may not register them with social + + align:start position:0% +may not register them with social + + + align:start position:0% +may not register them with social +security but if they need three kids to + + align:start position:0% +security but if they need three kids to + + + align:start position:0% +security but if they need three kids to +run the farm or four kids they have as + + align:start position:0% +run the farm or four kids they have as + + + align:start position:0% +run the farm or four kids they have as +many kids as they want so + + align:start position:0% +many kids as they want so + + + align:start position:0% +many kids as they want so +we found a lot of families with four + + align:start position:0% +we found a lot of families with four + + + align:start position:0% +we found a lot of families with four +five six eight kids + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% +um + + + align:start position:0% +um +so why has it been presumed to be + + align:start position:0% +so why has it been presumed to be + + + align:start position:0% +so why has it been presumed to be +difficult to do this kind of work what + + align:start position:0% +difficult to do this kind of work what + + + align:start position:0% +difficult to do this kind of work what +what's the reason that it's difficult i + + align:start position:0% +what's the reason that it's difficult i + + + align:start position:0% +what's the reason that it's difficult i +think these are some of the reason + + align:start position:0% +think these are some of the reason + + + align:start position:0% +think these are some of the reason +reasons and and some of them relate to + + align:start position:0% +reasons and and some of them relate to + + + align:start position:0% +reasons and and some of them relate to +the issues of study design the things + + align:start position:0% +the issues of study design the things + + + align:start position:0% +the issues of study design the things +that we were talking about you know one + + align:start position:0% +that we were talking about you know one + + + align:start position:0% +that we were talking about you know one +is this whole idea of genetic + + align:start position:0% +is this whole idea of genetic + + + align:start position:0% +is this whole idea of genetic +heterogeneity particularly if the + + align:start position:0% +heterogeneity particularly if the + + + align:start position:0% +heterogeneity particularly if the +underlying model here is gene by + + align:start position:0% +underlying model here is gene by + + + align:start position:0% +underlying model here is gene by +environment interaction presumably you + + align:start position:0% +environment interaction presumably you + + + align:start position:0% +environment interaction presumably you +could get the same phenotype + + align:start position:0% +could get the same phenotype + + + align:start position:0% +could get the same phenotype +and these phenotypes are determined by + + align:start position:0% +and these phenotypes are determined by + + + align:start position:0% +and these phenotypes are determined by +multiple genes + + align:start position:0% +multiple genes + + + align:start position:0% +multiple genes +and you know you can get the same + + align:start position:0% +and you know you can get the same + + + align:start position:0% +and you know you can get the same +phenotype either high ige or airways + + align:start position:0% +phenotype either high ige or airways + + + align:start position:0% +phenotype either high ige or airways +responsiveness in population a with a + + align:start position:0% +responsiveness in population a with a + + + align:start position:0% +responsiveness in population a with a +very different constellation of genes + + align:start position:0% +very different constellation of genes + + + align:start position:0% +very different constellation of genes +and environmental exposures and you can + + align:start position:0% +and environmental exposures and you can + + + align:start position:0% +and environmental exposures and you can +get the same thing + + align:start position:0% +get the same thing + + + align:start position:0% +get the same thing +in population b with with different + + align:start position:0% +in population b with with different + + + align:start position:0% +in population b with with different +genes + + align:start position:0% +genes + + + align:start position:0% +genes +so + + align:start position:0% +so + + + align:start position:0% +so +the this is the genetic heterogeneity + + align:start position:0% +the this is the genetic heterogeneity + + + align:start position:0% +the this is the genetic heterogeneity +thing is a reason for focusing on a + + align:start position:0% +thing is a reason for focusing on a + + + align:start position:0% +thing is a reason for focusing on a +genetic isolate + + align:start position:0% +genetic isolate + + + align:start position:0% +genetic isolate +but then you have to worry about the + + align:start position:0% +but then you have to worry about the + + + align:start position:0% +but then you have to worry about the +generalizability question so in fact in + + align:start position:0% +generalizability question so in fact in + + + align:start position:0% +generalizability question so in fact in +asthma there are four positionally + + align:start position:0% +asthma there are four positionally + + + align:start position:0% +asthma there are four positionally +cloned genes counting the paper that's + + align:start position:0% +cloned genes counting the paper that's + + + align:start position:0% +cloned genes counting the paper that's +going to come out on friday in science + + align:start position:0% +going to come out on friday in science + + + align:start position:0% +going to come out on friday in science +and and of those four the first is the + + align:start position:0% +and and of those four the first is the + + + align:start position:0% +and and of those four the first is the +only one that's people have really + + align:start position:0% +only one that's people have really + + + align:start position:0% +only one that's people have really +attempted to replicate + + align:start position:0% +attempted to replicate + + + align:start position:0% +attempted to replicate +um and it's sort of gotten mixed results + + align:start position:0% +um and it's sort of gotten mixed results + + + align:start position:0% +um and it's sort of gotten mixed results +you know there are some people that are + + align:start position:0% +you know there are some people that are + + + align:start position:0% +you know there are some people that are +replicated and some people that haven't + + align:start position:0% +replicated and some people that haven't + + + align:start position:0% +replicated and some people that haven't +so it's one of those genes that probably + + align:start position:0% +so it's one of those genes that probably + + + align:start position:0% +so it's one of those genes that probably +falls into this category of it well it's + + align:start position:0% +falls into this category of it well it's + + + align:start position:0% +falls into this category of it well it's +not a major gene it's a minor gene + + align:start position:0% +not a major gene it's a minor gene + + + align:start position:0% +not a major gene it's a minor gene +it's one of the 200 genes that determine + + align:start position:0% +it's one of the 200 genes that determine + + + align:start position:0% +it's one of the 200 genes that determine +asthma but it's not one of the top 10 in + + align:start position:0% +asthma but it's not one of the top 10 in + + + align:start position:0% +asthma but it's not one of the top 10 in +every population what's your guess about + + align:start position:0% +every population what's your guess about + + + align:start position:0% +every population what's your guess about +eugene + + align:start position:0% +eugene + + + align:start position:0% +eugene +my guess my guess about this new genius + + align:start position:0% +my guess my guess about this new genius + + + align:start position:0% +my guess my guess about this new genius +is that it's a major player yeah + + align:start position:0% +is that it's a major player yeah + + + align:start position:0% +is that it's a major player yeah +i think that + + align:start position:0% +i think that + + + align:start position:0% +i think that +you know uh um + + align:start position:0% +you know uh um + + + align:start position:0% +you know uh um +but + + align:start position:0% +but + + + align:start position:0% +but +having said that + + align:start position:0% +having said that + + + align:start position:0% +having said that +the point that i made to this science + + align:start position:0% +the point that i made to this science + + + align:start position:0% +the point that i made to this science +writer who was doing this is it you know + + align:start position:0% +writer who was doing this is it you know + + + align:start position:0% +writer who was doing this is it you know +as it's + + align:start position:0% +as it's + + + align:start position:0% +as it's +you know + + align:start position:0% +you know + + + align:start position:0% +you know +you know it's + + align:start position:0% +you know it's + + + align:start position:0% +you know it's +that's what science is all about is you + + align:start position:0% +that's what science is all about is you + + + align:start position:0% +that's what science is all about is you +know + + align:start position:0% +know + + + align:start position:0% +know +replicating this seeing how + + align:start position:0% +replicating this seeing how + + + align:start position:0% +replicating this seeing how +important it really is and seeing what + + align:start position:0% +important it really is and seeing what + + + align:start position:0% +important it really is and seeing what +actually happens you know i mean i i + + align:start position:0% +actually happens you know i mean i i + + + align:start position:0% +actually happens you know i mean i i +think you can get a clue as to + + align:start position:0% +think you can get a clue as to + + + align:start position:0% +think you can get a clue as to +um + + align:start position:0% +um + + + align:start position:0% +um +whether you've got hold of an area where + + align:start position:0% +whether you've got hold of an area where + + + align:start position:0% +whether you've got hold of an area where +there's a potential major locus or not + + align:start position:0% +there's a potential major locus or not + + + align:start position:0% +there's a potential major locus or not +by looking at the replicability of the + + align:start position:0% +by looking at the replicability of the + + + align:start position:0% +by looking at the replicability of the +linkage peaks in a particular reason + + align:start position:0% +linkage peaks in a particular reason + + + align:start position:0% +linkage peaks in a particular reason +region for a complex trade in other + + align:start position:0% +region for a complex trade in other + + + align:start position:0% +region for a complex trade in other +words if you've got a region where + + align:start position:0% +words if you've got a region where + + + align:start position:0% +words if you've got a region where +there's a linkage peak and and there are + + align:start position:0% +there's a linkage peak and and there are + + + align:start position:0% +there's a linkage peak and and there are +10 different studies in 10 different + + align:start position:0% +10 different studies in 10 different + + + align:start position:0% +10 different studies in 10 different +populations and that there's always a + + align:start position:0% +populations and that there's always a + + + align:start position:0% +populations and that there's always a +peak in the same region + + align:start position:0% +peak in the same region + + + align:start position:0% +peak in the same region +then the chances are that there's a + + align:start position:0% +then the chances are that there's a + + + align:start position:0% +then the chances are that there's a +major gene in there that's probably + + align:start position:0% +major gene in there that's probably + + + align:start position:0% +major gene in there that's probably +going to apply to a bunch of different + + align:start position:0% +going to apply to a bunch of different + + + align:start position:0% +going to apply to a bunch of different +populations well this is the going back + + align:start position:0% +populations well this is the going back + + + align:start position:0% +populations well this is the going back +to the science article that this is a + + align:start position:0% +to the science article that this is a + + + align:start position:0% +to the science article that this is a +region where there have been a number of + + align:start position:0% +region where there have been a number of + + + align:start position:0% +region where there have been a number of +people have found + + align:start position:0% +people have found + + + align:start position:0% +people have found +a peak there + + align:start position:0% +a peak there + + + align:start position:0% +a peak there +you know the other problem here is is + + align:start position:0% +you know the other problem here is is + + + align:start position:0% +you know the other problem here is is +that unlike + + align:start position:0% +that unlike + + + align:start position:0% +that unlike +single gene disorders where there's a + + align:start position:0% +single gene disorders where there's a + + + align:start position:0% +single gene disorders where there's a +known mode of inheritance you get + + align:start position:0% +known mode of inheritance you get + + + align:start position:0% +known mode of inheritance you get +everything + + align:start position:0% +everything + + + align:start position:0% +everything +under the kitchen sink here right so you + + align:start position:0% +under the kitchen sink here right so you + + + align:start position:0% +under the kitchen sink here right so you +get some of these genes or autosomal + + align:start position:0% +get some of these genes or autosomal + + + align:start position:0% +get some of these genes or autosomal +recessives and some are autosomal + + align:start position:0% +recessives and some are autosomal + + + align:start position:0% +recessives and some are autosomal +dominance and some are uh + + align:start position:0% +dominance and some are uh + + + align:start position:0% +dominance and some are uh +um + + align:start position:0% +um + + + align:start position:0% +um +so + + align:start position:0% +so + + + align:start position:0% +so +you're getting a whole bunch of things + + align:start position:0% +you're getting a whole bunch of things + + + align:start position:0% +you're getting a whole bunch of things +jumbled up in one phenotype which makes + + align:start position:0% +jumbled up in one phenotype which makes + + + align:start position:0% +jumbled up in one phenotype which makes +it very difficult + + align:start position:0% +it very difficult + + + align:start position:0% +it very difficult +and then there's this problem of + + align:start position:0% +and then there's this problem of + + + align:start position:0% +and then there's this problem of +phenocopies + + align:start position:0% +phenocopies + + + align:start position:0% +phenocopies +so what's what's a phenocopy + + align:start position:0% +so what's what's a phenocopy + + + align:start position:0% +so what's what's a phenocopy +give me a give me a give me an example + + align:start position:0% +give me a give me a give me an example + + + align:start position:0% +give me a give me a give me an example +from + + align:start position:0% +from + + + align:start position:0% +from +your own + + align:start position:0% +your own + + + align:start position:0% +your own +clinical experience of somebody who's + + align:start position:0% +clinical experience of somebody who's + + + align:start position:0% +clinical experience of somebody who's +a phenocopy who's not not due to a + + align:start position:0% + + + + align:start position:0% + +well just like you can get these + + align:start position:0% +well just like you can get these + + + align:start position:0% +well just like you can get these +diseases from jeans you can get them + + align:start position:0% +diseases from jeans you can get them + + + align:start position:0% +diseases from jeans you can get them +from exposures in the environment so + + align:start position:0% +from exposures in the environment so + + + align:start position:0% +from exposures in the environment so +what what if you've got some guy who + + align:start position:0% +what what if you've got some guy who + + + align:start position:0% +what what if you've got some guy who +smokes four packs a day and he's 50 + + align:start position:0% +smokes four packs a day and he's 50 + + + align:start position:0% +smokes four packs a day and he's 50 +years old and he has a whopping big + + align:start position:0% +years old and he has a whopping big + + + align:start position:0% +years old and he has a whopping big +heart attack + + align:start position:0% +heart attack + + + align:start position:0% +heart attack +well maybe he you know when you + + align:start position:0% +well maybe he you know when you + + + align:start position:0% +well maybe he you know when you +inclusivity has no family history but + + align:start position:0% +inclusivity has no family history but + + + align:start position:0% +inclusivity has no family history but +you smoke four packs a day well + + align:start position:0% +you smoke four packs a day well + + + align:start position:0% +you smoke four packs a day well +you can get a heart attack from smoking + + align:start position:0% +you can get a heart attack from smoking + + + align:start position:0% +you can get a heart attack from smoking +for four packs a day and you don't need + + align:start position:0% +for four packs a day and you don't need + + + align:start position:0% +for four packs a day and you don't need +to have any genes at all for heart + + align:start position:0% +to have any genes at all for heart + + + align:start position:0% +to have any genes at all for heart +attack you can just so that's a + + align:start position:0% +attack you can just so that's a + + + align:start position:0% +attack you can just so that's a +phenocopy he's going to look like + + align:start position:0% +phenocopy he's going to look like + + + align:start position:0% +phenocopy he's going to look like +somebody who's a genetic susceptible + + align:start position:0% +somebody who's a genetic susceptible + + + align:start position:0% +somebody who's a genetic susceptible +because he + + align:start position:0% +because he + + + align:start position:0% +because he +you know had a heart attack at 50 years + + align:start position:0% +you know had a heart attack at 50 years + + + align:start position:0% +you know had a heart attack at 50 years +old but it's all due to environmental + + align:start position:0% +old but it's all due to environmental + + + align:start position:0% +old but it's all due to environmental +exposure + + align:start position:0% +exposure + + + align:start position:0% +exposure +incomplete penetrance + + align:start position:0% +incomplete penetrance + + + align:start position:0% +incomplete penetrance +so this is + + align:start position:0% +so this is + + + align:start position:0% +so this is +this is a pop problem even in single + + align:start position:0% +this is a pop problem even in single + + + align:start position:0% +this is a pop problem even in single +gene disorders right because they're + + align:start position:0% +gene disorders right because they're + + + align:start position:0% +gene disorders right because they're +clearly examples um hemochromatosis + + align:start position:0% +clearly examples um hemochromatosis + + + align:start position:0% +clearly examples um hemochromatosis +cystic fibrosis very different spectrum + + align:start position:0% +cystic fibrosis very different spectrum + + + align:start position:0% +cystic fibrosis very different spectrum +of diseases and these what we know + + align:start position:0% +of diseases and these what we know + + + align:start position:0% +of diseases and these what we know +that + + align:start position:0% +that + + + align:start position:0% +that +you know + + align:start position:0% +you know + + + align:start position:0% +you know +the cftr gene causes cystic fibrosis you + + align:start position:0% +the cftr gene causes cystic fibrosis you + + + align:start position:0% +the cftr gene causes cystic fibrosis you +get some people who have completely + + align:start position:0% +get some people who have completely + + + align:start position:0% +get some people who have completely +normal lung function + + align:start position:0% +normal lung function + + + align:start position:0% +normal lung function +no lung disease at all + + align:start position:0% +no lung disease at all + + + align:start position:0% +no lung disease at all +and all they've got is mild pancreatic + + align:start position:0% +and all they've got is mild pancreatic + + + align:start position:0% +and all they've got is mild pancreatic +insufficiency and you've got other + + align:start position:0% +insufficiency and you've got other + + + align:start position:0% +insufficiency and you've got other +people who were totally debilitated from + + align:start position:0% +people who were totally debilitated from + + + align:start position:0% +people who were totally debilitated from +it so + + align:start position:0% +it so + + + align:start position:0% +it so +part of that can be penetrants part of + + align:start position:0% +part of that can be penetrants part of + + + align:start position:0% +part of that can be penetrants part of +it can be environmental exposure but + + align:start position:0% +it can be environmental exposure but + + + align:start position:0% +it can be environmental exposure but +incomplete penetrance is important then + + align:start position:0% +incomplete penetrance is important then + + + align:start position:0% +incomplete penetrance is important then +you've got this problem with multiple + + align:start position:0% +you've got this problem with multiple + + + align:start position:0% +you've got this problem with multiple +genes + + align:start position:0% +genes + + + align:start position:0% +genes +you know + + align:start position:0% +you know + + + align:start position:0% +you know +people have very + + align:start position:0% +people have very + + + align:start position:0% +people have very +the lay public has a very sort of + + align:start position:0% +the lay public has a very sort of + + + align:start position:0% +the lay public has a very sort of +delusional kind you know they think the + + align:start position:0% +delusional kind you know they think the + + + align:start position:0% +delusional kind you know they think the +genes are immutable you know if you've + + align:start position:0% +genes are immutable you know if you've + + + align:start position:0% +genes are immutable you know if you've +got those genes that's it you know it + + align:start position:0% +got those genes that's it you know it + + + align:start position:0% +got those genes that's it you know it +can't be changed and they also they're + + align:start position:0% +can't be changed and they also they're + + + align:start position:0% +can't be changed and they also they're +monolithic they're really big whereas + + align:start position:0% +monolithic they're really big whereas + + + align:start position:0% +monolithic they're really big whereas +the reality is is that anyone you know + + align:start position:0% +the reality is is that anyone you know + + + align:start position:0% +the reality is is that anyone you know +you got 33 000 genes in the genome take + + align:start position:0% +you got 33 000 genes in the genome take + + + align:start position:0% +you got 33 000 genes in the genome take +a disease like asthma which isn't very + + align:start position:0% +a disease like asthma which isn't very + + + align:start position:0% +a disease like asthma which isn't very +complicated maybe they're 200 + + align:start position:0% +complicated maybe they're 200 + + + align:start position:0% +complicated maybe they're 200 +250 i don't know + + align:start position:0% +250 i don't know + + + align:start position:0% +250 i don't know +a lot + + align:start position:0% +a lot + + + align:start position:0% +a lot +that are probably important maybe 10 + + align:start position:0% +that are probably important maybe 10 + + + align:start position:0% +that are probably important maybe 10 +that play + + align:start position:0% +that play + + + align:start position:0% +that play +a a a a role in most every population um + + align:start position:0% +a a a a role in most every population um + + + align:start position:0% +a a a a role in most every population um +and a lot of environmental things going + + align:start position:0% +and a lot of environmental things going + + + align:start position:0% +and a lot of environmental things going +on and it makes it very complicated and + + align:start position:0% +on and it makes it very complicated and + + + align:start position:0% +on and it makes it very complicated and +that's why guys like + + align:start position:0% +that's why guys like + + + align:start position:0% +that's why guys like +this guy are going to make big bucks + + align:start position:0% +this guy are going to make big bucks + + + align:start position:0% +this guy are going to make big bucks +because they're going to be able to + + align:start position:0% +because they're going to be able to + + + align:start position:0% +because they're going to be able to +model + + align:start position:0% +model + + + align:start position:0% +model +all of the different pathways and + + align:start position:0% +all of the different pathways and + + + align:start position:0% +all of the different pathways and +you know the different genes together in + + align:start position:0% +you know the different genes together in + + + align:start position:0% +you know the different genes together in +some more realistic model of + + align:start position:0% +some more realistic model of + + + align:start position:0% +some more realistic model of +you know systems biology or some actual + + align:start position:0% +you know systems biology or some actual + + + align:start position:0% +you know systems biology or some actual +way of looking at this but the point + + align:start position:0% +way of looking at this but the point + + + align:start position:0% +way of looking at this but the point +here basically is look + + align:start position:0% +here basically is look + + + align:start position:0% +here basically is look +it's complicated to do this stuff + + align:start position:0% +it's complicated to do this stuff + + + align:start position:0% +it's complicated to do this stuff +again going back to what i said earlier + + align:start position:0% +again going back to what i said earlier + + + align:start position:0% +again going back to what i said earlier +it's getting a lot easier so + + align:start position:0% +it's getting a lot easier so + + + align:start position:0% +it's getting a lot easier so + + align:start position:0% + + + align:start position:0% +one position like clone gene for asthma + + align:start position:0% +one position like clone gene for asthma + + + align:start position:0% +one position like clone gene for asthma + + align:start position:0% + + + align:start position:0% +two positionally cloned gene from + + align:start position:0% +two positionally cloned gene from + + + align:start position:0% +two positionally cloned gene from +from asthma 2004 first paper is already + + align:start position:0% +from asthma 2004 first paper is already + + + align:start position:0% +from asthma 2004 first paper is already +out and there's probably going to be + + align:start position:0% +out and there's probably going to be + + + align:start position:0% +out and there's probably going to be +four or five more + + align:start position:0% +four or five more + + + align:start position:0% +four or five more +so it can be four or five this year year + + align:start position:0% +so it can be four or five this year year + + + align:start position:0% +so it can be four or five this year year +after that they're going to be probably + + align:start position:0% +after that they're going to be probably + + + align:start position:0% +after that they're going to be probably +10 and all of a sudden now you got 20 + + align:start position:0% +10 and all of a sudden now you got 20 + + + align:start position:0% +10 and all of a sudden now you got 20 +genes identified for the disease by + + align:start position:0% +genes identified for the disease by + + + align:start position:0% +genes identified for the disease by +positional cloning and that is the + + align:start position:0% +positional cloning and that is the + + + align:start position:0% +positional cloning and that is the +history of complex trait genetics and + + align:start position:0% +history of complex trait genetics and + + + align:start position:0% +history of complex trait genetics and +it's going to be it's it's happening + + align:start position:0% +it's going to be it's it's happening + + + align:start position:0% +it's going to be it's it's happening +right now right this very moment + + align:start position:0% +right now right this very moment + + + align:start position:0% +right now right this very moment +all across the world labs like mine are + + align:start position:0% +all across the world labs like mine are + + + align:start position:0% +all across the world labs like mine are +right in the middle of the fray doing + + align:start position:0% +right in the middle of the fray doing + + + align:start position:0% +right in the middle of the fray doing +this stuff + + align:start position:0% +this stuff + + + align:start position:0% +this stuff +this is + + align:start position:0% +this is + + + align:start position:0% +this is +simply put the single most exciting time + + align:start position:0% +simply put the single most exciting time + + + align:start position:0% +simply put the single most exciting time +to be doing human genetics and + + align:start position:0% +to be doing human genetics and + + + align:start position:0% +to be doing human genetics and +uh uh it's + + align:start position:0% +uh uh it's + + + align:start position:0% +uh uh it's +going to go on for a while but who knows + + align:start position:0% +going to go on for a while but who knows + + + align:start position:0% +going to go on for a while but who knows +for how long + + align:start position:0% +for how long + + + align:start position:0% +for how long +um + + align:start position:0% +um + + + align:start position:0% +um +so then there's this other problem of + + align:start position:0% +so then there's this other problem of + + + align:start position:0% +so then there's this other problem of +pleiotropy which is + + align:start position:0% +pleiotropy which is + + + align:start position:0% +pleiotropy which is +you know you could have one gene and it + + align:start position:0% +you know you could have one gene and it + + + align:start position:0% +you know you could have one gene and it +can do a lot of different things you get + + align:start position:0% +can do a lot of different things you get + + + align:start position:0% +can do a lot of different things you get +the cftr gene that gives you lung + + align:start position:0% +the cftr gene that gives you lung + + + align:start position:0% +the cftr gene that gives you lung +disease pancreatic insufficiency + + align:start position:0% +disease pancreatic insufficiency + + + align:start position:0% +disease pancreatic insufficiency +infertility you know it's all has to do + + align:start position:0% +infertility you know it's all has to do + + + align:start position:0% +infertility you know it's all has to do +with + + align:start position:0% +with + + + align:start position:0% +with +mucosa and epithelia and different organ + + align:start position:0% +mucosa and epithelia and different organ + + + align:start position:0% +mucosa and epithelia and different organ +systems where this particular gene is + + align:start position:0% +systems where this particular gene is + + + align:start position:0% +systems where this particular gene is +expressed so one of the genes we're + + align:start position:0% +expressed so one of the genes we're + + + align:start position:0% +expressed so one of the genes we're +looking at and so jeff did jeff talk to + + align:start position:0% +looking at and so jeff did jeff talk to + + + align:start position:0% +looking at and so jeff did jeff talk to +you about uh crh1 + + align:start position:0% +you about uh crh1 + + + align:start position:0% +you about uh crh1 +did we show you the data about crh1 last + + align:start position:0% +did we show you the data about crh1 last + + + align:start position:0% +did we show you the data about crh1 last +week + + align:start position:0% +week + + + align:start position:0% +week +so + + align:start position:0% +so + + + align:start position:0% +so +that gene + + align:start position:0% + + + + align:start position:0% + +gene is expressed is that gene expressed + + align:start position:0% +gene is expressed is that gene expressed + + + align:start position:0% +gene is expressed is that gene expressed +in the lung + + align:start position:0% + + + + align:start position:0% + +yes or no + + align:start position:0% + + + + align:start position:0% + +no + + align:start position:0% +no + + + align:start position:0% +no +not expressed in the lung + + align:start position:0% +not expressed in the lung + + + align:start position:0% +not expressed in the lung +so it's the + + align:start position:0% +so it's the + + + align:start position:0% +so it's the +receptor for crf or crh and it's + + align:start position:0% +receptor for crf or crh and it's + + + align:start position:0% +receptor for crf or crh and it's +expressed in the brain + + align:start position:0% +expressed in the brain + + + align:start position:0% +expressed in the brain +so + + align:start position:0% +so + + + align:start position:0% +so +what other disease might that gene + + align:start position:0% +what other disease might that gene + + + align:start position:0% +what other disease might that gene +potentially be important in + + align:start position:0% + + + + align:start position:0% + +he's an endocrinologist he's forbidden + + align:start position:0% +he's an endocrinologist he's forbidden + + + align:start position:0% +he's an endocrinologist he's forbidden +from answering + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +what + + align:start position:0% + + + + align:start position:0% + +it's a comes from the hypothalamus + + align:start position:0% +it's a comes from the hypothalamus + + + align:start position:0% +it's a comes from the hypothalamus +actually + + align:start position:0% +actually + + + align:start position:0% +actually +so + + align:start position:0% + + + + align:start position:0% + +yeah clinical or pimple disease + + align:start position:0% + + + + align:start position:0% + +hypertension + + align:start position:0% + + + + align:start position:0% + +there are endocrine causes of + + align:start position:0% +there are endocrine causes of + + + align:start position:0% +there are endocrine causes of +hypertension your physiology course yet + + align:start position:0% +hypertension your physiology course yet + + + align:start position:0% +hypertension your physiology course yet +oh no all right + + align:start position:0% +oh no all right + + + align:start position:0% +oh no all right +anybody had physiology + + align:start position:0% + + + + align:start position:0% + +hpa + + align:start position:0% +hpa + + + align:start position:0% +hpa +okay so um + + align:start position:0% +okay so um + + + align:start position:0% +okay so um +no come on i think calm diseases man + + align:start position:0% +no come on i think calm diseases man + + + align:start position:0% +no come on i think calm diseases man +common common common disease + + align:start position:0% +common common common disease + + + align:start position:0% +common common common disease +i'll tell you it's depression okay + + align:start position:0% +i'll tell you it's depression okay + + + align:start position:0% +i'll tell you it's depression okay +it's it's actually it's an it's it's + + align:start position:0% +it's it's actually it's an it's it's + + + align:start position:0% +it's it's actually it's an it's it's +been studied a huge amount and you know + + align:start position:0% +been studied a huge amount and you know + + + align:start position:0% +been studied a huge amount and you know +they've sectioned brains of people who + + align:start position:0% +they've sectioned brains of people who + + + align:start position:0% +they've sectioned brains of people who +committed suicide and this + + align:start position:0% +committed suicide and this + + + align:start position:0% +committed suicide and this +i mean all kinds of things show that cr + + align:start position:0% +i mean all kinds of things show that cr + + + align:start position:0% +i mean all kinds of things show that cr +crf and cr1 which is the ligand and the + + align:start position:0% +crf and cr1 which is the ligand and the + + + align:start position:0% +crf and cr1 which is the ligand and the +receptor are important in + + align:start position:0% +receptor are important in + + + align:start position:0% +receptor are important in +affective disorders is there any linkage + + align:start position:0% +affective disorders is there any linkage + + + align:start position:0% +affective disorders is there any linkage +well + + align:start position:0% +well + + + align:start position:0% +well +there's an association between our + + align:start position:0% +there's an association between our + + + align:start position:0% +there's an association between our +capital type and depression and + + align:start position:0% +capital type and depression and + + + align:start position:0% +capital type and depression and +julia lucinia's mexican-american + + align:start position:0% +julia lucinia's mexican-american + + + align:start position:0% +julia lucinia's mexican-american +yeah oh yeah really cool yeah + + align:start position:0% +yeah oh yeah really cool yeah + + + align:start position:0% +yeah oh yeah really cool yeah +so that's pleiotropy uh and then + + align:start position:0% +so that's pleiotropy uh and then + + + align:start position:0% +so that's pleiotropy uh and then +obviously you've got this problem with + + align:start position:0% +obviously you've got this problem with + + + align:start position:0% +obviously you've got this problem with +penetrance that + + align:start position:0% +penetrance that + + + align:start position:0% +penetrance that +you know + + align:start position:0% +you know + + + align:start position:0% +you know +which is + + align:start position:0% +which is + + + align:start position:0% +which is +individuals with a genotype will + + align:start position:0% +individuals with a genotype will + + + align:start position:0% +individuals with a genotype will +actually express the trait + + align:start position:0% +actually express the trait + + + align:start position:0% +actually express the trait +and + + align:start position:0% +and + + + align:start position:0% +and +you know ige genes can be important in + + align:start position:0% +you know ige genes can be important in + + + align:start position:0% +you know ige genes can be important in +hay fever they can be important in + + align:start position:0% +hay fever they can be important in + + + align:start position:0% +hay fever they can be important in +asthma uh and and there are some people + + align:start position:0% +asthma uh and and there are some people + + + align:start position:0% +asthma uh and and there are some people +who don't have + + align:start position:0% +who don't have + + + align:start position:0% +who don't have +high ig at all even though they've got + + align:start position:0% +high ig at all even though they've got + + + align:start position:0% +high ig at all even though they've got +the gene so uh um + + align:start position:0% +the gene so uh um + + + align:start position:0% +the gene so uh um +and and these are some other examples of + + align:start position:0% +and and these are some other examples of + + + align:start position:0% +and and these are some other examples of +things like the the basic point i'm + + align:start position:0% +things like the the basic point i'm + + + align:start position:0% +things like the the basic point i'm +trying to make here is is that these are + + align:start position:0% +trying to make here is is that these are + + + align:start position:0% +trying to make here is is that these are +reasons that have been given for why + + align:start position:0% +reasons that have been given for why + + + align:start position:0% +reasons that have been given for why +doing this stuff this are + + align:start position:0% +doing this stuff this are + + + align:start position:0% +doing this stuff this are +hard but i'll tell you something the + + align:start position:0% +hard but i'll tell you something the + + + align:start position:0% +hard but i'll tell you something the +really the hard part has been developing + + align:start position:0% +really the hard part has been developing + + + align:start position:0% +really the hard part has been developing +the bioinformatics infrastructure the + + align:start position:0% +the bioinformatics infrastructure the + + + align:start position:0% +the bioinformatics infrastructure the +tools the bioinformatics tools and cheap + + align:start position:0% +tools the bioinformatics tools and cheap + + + align:start position:0% +tools the bioinformatics tools and cheap +reliable + + align:start position:0% +reliable + + + align:start position:0% +reliable +genotyping that those have really been + + align:start position:0% +genotyping that those have really been + + + align:start position:0% +genotyping that those have really been +the things that have been important + + align:start position:0% +the things that have been important + + + align:start position:0% +the things that have been important +and just in the little bit of time that + + align:start position:0% +and just in the little bit of time that + + + align:start position:0% +and just in the little bit of time that +i've been doing this + + align:start position:0% +i've been doing this + + + align:start position:0% +i've been doing this +my genotyping costs are have gone from + + align:start position:0% +my genotyping costs are have gone from + + + align:start position:0% +my genotyping costs are have gone from +a dollar 20 a sniff genotype + + align:start position:0% +a dollar 20 a sniff genotype + + + align:start position:0% +a dollar 20 a sniff genotype +down to next year + + align:start position:0% +down to next year + + + align:start position:0% +down to next year +uh i'll be down at about 15 20 cents of + + align:start position:0% +uh i'll be down at about 15 20 cents of + + + align:start position:0% +uh i'll be down at about 15 20 cents of +sniff genotype + + align:start position:0% +sniff genotype + + + align:start position:0% +sniff genotype +and + + align:start position:0% +and + + + align:start position:0% +and +you know + + align:start position:0% +you know + + + align:start position:0% +you know +there are + + align:start position:0% +there are + + + align:start position:0% +there are +three million snips + + align:start position:0% +three million snips + + + align:start position:0% +three million snips +minimum three to five million in the + + align:start position:0% +minimum three to five million in the + + + align:start position:0% +minimum three to five million in the +human genome now i'm not going to type + + align:start position:0% +human genome now i'm not going to type + + + align:start position:0% +human genome now i'm not going to type +it three to five million but i gotta + + align:start position:0% +it three to five million but i gotta + + + align:start position:0% +it three to five million but i gotta +type + + align:start position:0% +type + + + align:start position:0% +type +in any one experiment i got to be able + + align:start position:0% +in any one experiment i got to be able + + + align:start position:0% +in any one experiment i got to be able +to type + + align:start position:0% +to type + + + align:start position:0% +to type +a thousand over a a 10 20 + + align:start position:0% +a thousand over a a 10 20 + + + align:start position:0% +a thousand over a a 10 20 +uh uh um megabase region so + + align:start position:0% +uh uh um megabase region so + + + align:start position:0% +uh uh um megabase region so +you know one of these linkage peaks so i + + align:start position:0% +you know one of these linkage peaks so i + + + align:start position:0% +you know one of these linkage peaks so i +got to do a lot of genotyping in a lot + + align:start position:0% +got to do a lot of genotyping in a lot + + + align:start position:0% +got to do a lot of genotyping in a lot +of people and it's expensive the very + + align:start position:0% +of people and it's expensive the very + + + align:start position:0% +of people and it's expensive the very +first positionally cloned gene for + + align:start position:0% +first positionally cloned gene for + + + align:start position:0% +first positionally cloned gene for +asthma took six years and fifteen point + + align:start position:0% +asthma took six years and fifteen point + + + align:start position:0% +asthma took six years and fifteen point +six million dollars we could do that + + align:start position:0% +six million dollars we could do that + + + align:start position:0% +six million dollars we could do that +experiment today for two million dollars + + align:start position:0% +experiment today for two million dollars + + + align:start position:0% +experiment today for two million dollars +and a regular nih grant and that has + + align:start position:0% +and a regular nih grant and that has + + + align:start position:0% +and a regular nih grant and that has +totally changed the field that's the + + align:start position:0% +totally changed the field that's the + + + align:start position:0% +totally changed the field that's the +kind of thing that's really making + + align:start position:0% +kind of thing that's really making + + + align:start position:0% +kind of thing that's really making +this possible + + align:start position:0% +this possible + + + align:start position:0% +this possible +um + + align:start position:0% +um + + + align:start position:0% +um +okay so i already said that + + align:start position:0% +okay so i already said that + + + align:start position:0% +okay so i already said that +if you're if you're going to think like + + align:start position:0% +if you're if you're going to think like + + + align:start position:0% +if you're if you're going to think like +a geneticist everybody has to know a + + align:start position:0% +a geneticist everybody has to know a + + + align:start position:0% +a geneticist everybody has to know a +little bit of population genetics so you + + align:start position:0% +little bit of population genetics so you + + + align:start position:0% +little bit of population genetics so you +have to understand the concepts of + + align:start position:0% +have to understand the concepts of + + + align:start position:0% +have to understand the concepts of +linkage disequilibrium drifts + + align:start position:0% +linkage disequilibrium drifts + + + align:start position:0% +linkage disequilibrium drifts +natural selection + + align:start position:0% + + + + align:start position:0% + +et cetera et cetera i'm reminded of the + + align:start position:0% +et cetera et cetera i'm reminded of the + + + align:start position:0% +et cetera et cetera i'm reminded of the +fact that uh somebody asked the + + align:start position:0% +fact that uh somebody asked the + + + align:start position:0% +fact that uh somebody asked the +president united states whether he + + align:start position:0% +president united states whether he + + + align:start position:0% +president united states whether he +believed in evolution and his answer was + + align:start position:0% +believed in evolution and his answer was + + + align:start position:0% +believed in evolution and his answer was +the jury's still out + + align:start position:0% +the jury's still out + + + align:start position:0% +the jury's still out +really yeah + + align:start position:0% +really yeah + + + align:start position:0% +really yeah +that's what he said + + align:start position:0% +that's what he said + + + align:start position:0% +that's what he said +um so this is your former classmate + + align:start position:0% +um so this is your former classmate + + + align:start position:0% +um so this is your former classmate +right right + + align:start position:0% +right right + + + align:start position:0% +right right +um i went to high school with the + + align:start position:0% +um i went to high school with the + + + align:start position:0% +um i went to high school with the +president um + + align:start position:0% +president um + + + align:start position:0% +president um +so + + align:start position:0% +so + + + align:start position:0% +so +this is the first question that you're + + align:start position:0% +this is the first question that you're + + + align:start position:0% +this is the first question that you're +going to get asked + + align:start position:0% +going to get asked + + + align:start position:0% +going to get asked +if you're writing a grant you know the + + align:start position:0% +if you're writing a grant you know the + + + align:start position:0% +if you're writing a grant you know the +first thing that you have to address + + align:start position:0% +first thing that you have to address + + + align:start position:0% +first thing that you have to address +is is the disease or the phenotype that + + align:start position:0% +is is the disease or the phenotype that + + + align:start position:0% +is is the disease or the phenotype that +you're interested in is it heritable so + + align:start position:0% +you're interested in is it heritable so + + + align:start position:0% +you're interested in is it heritable so +there's lots of different ways to + + align:start position:0% +there's lots of different ways to + + + align:start position:0% +there's lots of different ways to +measure this you can + + align:start position:0% +measure this you can + + + align:start position:0% +measure this you can +calculate a heritability estimates you + + align:start position:0% +calculate a heritability estimates you + + + align:start position:0% +calculate a heritability estimates you +can do twin studies you can develop this + + align:start position:0% +can do twin studies you can develop this + + + align:start position:0% +can do twin studies you can develop this +concept of risk to relatives which is + + align:start position:0% +concept of risk to relatives which is + + + align:start position:0% +concept of risk to relatives which is +you know you look at the risk + + align:start position:0% + + + + align:start position:0% + +uh in in the uh pro bands divided by or + + align:start position:0% +uh in in the uh pro bands divided by or + + + align:start position:0% +uh in in the uh pro bands divided by or +the relatives divided by the risk in the + + align:start position:0% +the relatives divided by the risk in the + + + align:start position:0% +the relatives divided by the risk in the +population at large or you can look at + + align:start position:0% +population at large or you can look at + + + align:start position:0% +population at large or you can look at +familial aggregation but the point is + + align:start position:0% +familial aggregation but the point is + + + align:start position:0% +familial aggregation but the point is +you got to gather the evidence and if + + align:start position:0% +you got to gather the evidence and if + + + align:start position:0% +you got to gather the evidence and if +you don't know that your phenotype is + + align:start position:0% +you don't know that your phenotype is + + + align:start position:0% +you don't know that your phenotype is +heritable you're going to have to + + align:start position:0% +heritable you're going to have to + + + align:start position:0% +heritable you're going to have to +demonstrate that it's heritable before + + align:start position:0% +demonstrate that it's heritable before + + + align:start position:0% +demonstrate that it's heritable before +anybody's going to give you a grant to + + align:start position:0% +anybody's going to give you a grant to + + + align:start position:0% +anybody's going to give you a grant to +study it because that's what geneticists + + align:start position:0% +study it because that's what geneticists + + + align:start position:0% +study it because that's what geneticists +say they say they want to know that + + align:start position:0% +say they say they want to know that + + + align:start position:0% +say they say they want to know that +they want to know the answer to that + + align:start position:0% +they want to know the answer to that + + + align:start position:0% +they want to know the answer to that +question so i i think it's asthma + + align:start position:0% +question so i i think it's asthma + + + align:start position:0% +question so i i think it's asthma +doesn't necessarily have a high + + align:start position:0% +doesn't necessarily have a high + + + align:start position:0% +doesn't necessarily have a high +heritability but it clearly is a + + align:start position:0% +heritability but it clearly is a + + + align:start position:0% +heritability but it clearly is a +heritable disease this is data from one + + align:start position:0% +heritable disease this is data from one + + + align:start position:0% +heritable disease this is data from one +uh a twin study from danish twin + + align:start position:0% +uh a twin study from danish twin + + + align:start position:0% +uh a twin study from danish twin +registry that looked at the concordance + + align:start position:0% +registry that looked at the concordance + + + align:start position:0% +registry that looked at the concordance +of uh um + + align:start position:0% +of uh um + + + align:start position:0% +of uh um +asthma in identical and fraternal twins + + align:start position:0% +asthma in identical and fraternal twins + + + align:start position:0% +asthma in identical and fraternal twins +identical twins share 100 percent of + + align:start position:0% +identical twins share 100 percent of + + + align:start position:0% +identical twins share 100 percent of +their genotype fraternal twins uh uh um + + align:start position:0% +their genotype fraternal twins uh uh um + + + align:start position:0% +their genotype fraternal twins uh uh um +share fifty percent + + align:start position:0% +share fifty percent + + + align:start position:0% +share fifty percent +uh um uh uh of their alleles + + align:start position:0% +uh um uh uh of their alleles + + + align:start position:0% +uh um uh uh of their alleles +you know everybody knows that twins also + + align:start position:0% +you know everybody knows that twins also + + + align:start position:0% +you know everybody knows that twins also +share the environment so that's another + + align:start position:0% +share the environment so that's another + + + align:start position:0% +share the environment so that's another +factor that's uh + + align:start position:0% +factor that's uh + + + align:start position:0% +factor that's uh +at issue here but the reality is is that + + align:start position:0% +at issue here but the reality is is that + + + align:start position:0% +at issue here but the reality is is that +there clearly is evidence of + + align:start position:0% +there clearly is evidence of + + + align:start position:0% +there clearly is evidence of +heritability of the disease you get very + + align:start position:0% +heritability of the disease you get very + + + align:start position:0% +heritability of the disease you get very +different you know that the problem here + + align:start position:0% +different you know that the problem here + + + align:start position:0% +different you know that the problem here +is that heritability estimates are + + align:start position:0% +is that heritability estimates are + + + align:start position:0% +is that heritability estimates are +always dependent on + + align:start position:0% +always dependent on + + + align:start position:0% +always dependent on +environmental exposures as well because + + align:start position:0% +environmental exposures as well because + + + align:start position:0% +environmental exposures as well because +the true underlying model and disease + + align:start position:0% +the true underlying model and disease + + + align:start position:0% +the true underlying model and disease +prevalence so the true underlying model + + align:start position:0% +prevalence so the true underlying model + + + align:start position:0% +prevalence so the true underlying model +for all of these diseases is clearly + + align:start position:0% +for all of these diseases is clearly + + + align:start position:0% +for all of these diseases is clearly +still going to be a gene by environment + + align:start position:0% +still going to be a gene by environment + + + align:start position:0% +still going to be a gene by environment +interaction + + align:start position:0% +interaction + + + align:start position:0% +interaction +so + + align:start position:0% +so + + + align:start position:0% +so +after you've decided that the phenotypes + + align:start position:0% +after you've decided that the phenotypes + + + align:start position:0% +after you've decided that the phenotypes +that you're interested in are heritable + + align:start position:0% +that you're interested in are heritable + + + align:start position:0% +that you're interested in are heritable +then you've got to go out and you've got + + align:start position:0% +then you've got to go out and you've got + + + align:start position:0% +then you've got to go out and you've got +to say okay i've got these phenotypes + + align:start position:0% +to say okay i've got these phenotypes + + + align:start position:0% +to say okay i've got these phenotypes +and i'm going to genotype them + + align:start position:0% +and i'm going to genotype them + + + align:start position:0% +and i'm going to genotype them +in a population you can either look at + + align:start position:0% +in a population you can either look at + + + align:start position:0% +in a population you can either look at +disease phenotypes the advantages of + + align:start position:0% +disease phenotypes the advantages of + + + align:start position:0% +disease phenotypes the advantages of +this is that people want to look at + + align:start position:0% +this is that people want to look at + + + align:start position:0% +this is that people want to look at +asthma they want asthma genes they they + + align:start position:0% +asthma they want asthma genes they they + + + align:start position:0% +asthma they want asthma genes they they +want to find + + align:start position:0% +want to find + + + align:start position:0% +want to find +quote the gene for asthma unquote which + + align:start position:0% +quote the gene for asthma unquote which + + + align:start position:0% +quote the gene for asthma unquote which +we already know is probably a false + + align:start position:0% +we already know is probably a false + + + align:start position:0% +we already know is probably a false +concept + + align:start position:0% +concept + + + align:start position:0% +concept +but the problem with a lot of disease + + align:start position:0% +but the problem with a lot of disease + + + align:start position:0% +but the problem with a lot of disease +phenotypes is that they even though + + align:start position:0% +phenotypes is that they even though + + + align:start position:0% +phenotypes is that they even though +they're maybe binary clinically + + align:start position:0% +they're maybe binary clinically + + + align:start position:0% +they're maybe binary clinically +they may be + + align:start position:0% +they may be + + + align:start position:0% +they may be +real problems in terms of making that + + align:start position:0% +real problems in terms of making that + + + align:start position:0% +real problems in terms of making that +diagnosis + + align:start position:0% +diagnosis + + + align:start position:0% +diagnosis +in a way that would be useful for a a + + align:start position:0% +in a way that would be useful for a a + + + align:start position:0% +in a way that would be useful for a a +research study + + align:start position:0% +research study + + + align:start position:0% +research study +the problem with asthma is it's a + + align:start position:0% +the problem with asthma is it's a + + + align:start position:0% +the problem with asthma is it's a +syndrome right i mean there is no + + align:start position:0% +syndrome right i mean there is no + + + align:start position:0% +syndrome right i mean there is no +one way of diagnosing asthma so that you + + align:start position:0% +one way of diagnosing asthma so that you + + + align:start position:0% +one way of diagnosing asthma so that you +can say you take this test and i can + + align:start position:0% +can say you take this test and i can + + + align:start position:0% +can say you take this test and i can +guarantee you that everybody that takes + + align:start position:0% +guarantee you that everybody that takes + + + align:start position:0% +guarantee you that everybody that takes +this test is going to have the disease + + align:start position:0% +this test is going to have the disease + + + align:start position:0% +this test is going to have the disease +and everybody who has a negative test + + align:start position:0% +and everybody who has a negative test + + + align:start position:0% +and everybody who has a negative test +doesn't have the disease + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +yeah but the fev1 doesn't tell you + + align:start position:0% +yeah but the fev1 doesn't tell you + + + align:start position:0% +yeah but the fev1 doesn't tell you +whether somebody's got asthma or not + + align:start position:0% +whether somebody's got asthma or not + + + align:start position:0% +whether somebody's got asthma or not +i can show you people who have reduced + + align:start position:0% +i can show you people who have reduced + + + align:start position:0% +i can show you people who have reduced +fev1 and have cystic fibrosis or have + + align:start position:0% +fev1 and have cystic fibrosis or have + + + align:start position:0% +fev1 and have cystic fibrosis or have +interstitial lung disease or have uh + + align:start position:0% +interstitial lung disease or have uh + + + align:start position:0% +interstitial lung disease or have uh +copd i mean they can have a lot of + + align:start position:0% +copd i mean they can have a lot of + + + align:start position:0% +copd i mean they can have a lot of +different things right uh so it lacks + + align:start position:0% +different things right uh so it lacks + + + align:start position:0% +different things right uh so it lacks +sensitivity and specificity the fev one + + align:start position:0% +sensitivity and specificity the fev one + + + align:start position:0% +sensitivity and specificity the fev one +and that's true for every single test + + align:start position:0% +and that's true for every single test + + + align:start position:0% +and that's true for every single test +you know i mean + + align:start position:0% +you know i mean + + + align:start position:0% +you know i mean +elevated ige well you could have + + align:start position:0% +elevated ige well you could have + + + align:start position:0% +elevated ige well you could have +elevated ig from parasitic disease or + + align:start position:0% +elevated ig from parasitic disease or + + + align:start position:0% +elevated ig from parasitic disease or +from uh uh uh eosinophilic pneumonia or + + align:start position:0% +from uh uh uh eosinophilic pneumonia or + + + align:start position:0% +from uh uh uh eosinophilic pneumonia or +from 20 other different things so + + align:start position:0% +from 20 other different things so + + + align:start position:0% +from 20 other different things so +there is no single test + + align:start position:0% +there is no single test + + + align:start position:0% +there is no single test +and and and the same may be true for + + align:start position:0% +and and and the same may be true for + + + align:start position:0% +and and and the same may be true for +most complex traits + + align:start position:0% +most complex traits + + + align:start position:0% +most complex traits +um + + align:start position:0% +um + + + align:start position:0% +um +there may be some phenotypes that are a + + align:start position:0% +there may be some phenotypes that are a + + + align:start position:0% +there may be some phenotypes that are a +little easier to measure like you know + + align:start position:0% +little easier to measure like you know + + + align:start position:0% +little easier to measure like you know +say well + + align:start position:0% +say well + + + align:start position:0% +say well +i want to study obesity + + align:start position:0% +i want to study obesity + + + align:start position:0% +i want to study obesity +well + + align:start position:0% +well + + + align:start position:0% +well +how fat is fat or + + align:start position:0% +how fat is fat or + + + align:start position:0% +how fat is fat or +is + + align:start position:0% +is + + + align:start position:0% +is +people who are fat like this + + align:start position:0% +people who are fat like this + + + align:start position:0% +people who are fat like this +different from people who are fat like + + align:start position:0% +different from people who are fat like + + + align:start position:0% +different from people who are fat like +this + + align:start position:0% +this + + + align:start position:0% +this +you know i mean there's all sorts of + + align:start position:0% +you know i mean there's all sorts of + + + align:start position:0% +you know i mean there's all sorts of +different + + align:start position:0% +different + + + align:start position:0% +different +ways of looking fat so + + align:start position:0% +ways of looking fat so + + + align:start position:0% +ways of looking fat so +or being fat so + + align:start position:0% +or being fat so + + + align:start position:0% +or being fat so +you know any one of these phenotypes has + + align:start position:0% +you know any one of these phenotypes has + + + align:start position:0% +you know any one of these phenotypes has +complications and and and + + align:start position:0% +complications and and and + + + align:start position:0% +complications and and and +i can tell you this from from when i + + align:start position:0% +i can tell you this from from when i + + + align:start position:0% +i can tell you this from from when i +first got into this + + align:start position:0% +first got into this + + + align:start position:0% +first got into this +all i knew was phenotype i was a + + align:start position:0% +all i knew was phenotype i was a + + + align:start position:0% +all i knew was phenotype i was a +world-class phenotyper i knew all of the + + align:start position:0% +world-class phenotyper i knew all of the + + + align:start position:0% +world-class phenotyper i knew all of the +nuances of phenotype and everything + + align:start position:0% +nuances of phenotype and everything + + + align:start position:0% +nuances of phenotype and everything +there is to know about phenotype and + + align:start position:0% +there is to know about phenotype and + + + align:start position:0% +there is to know about phenotype and +that's tends to be what happens when you + + align:start position:0% +that's tends to be what happens when you + + + align:start position:0% +that's tends to be what happens when you +when you talk to clinicians because they + + align:start position:0% +when you talk to clinicians because they + + + align:start position:0% +when you talk to clinicians because they +understand that more so + + align:start position:0% +understand that more so + + + align:start position:0% +understand that more so +this stuff is really really important + + align:start position:0% +this stuff is really really important + + + align:start position:0% +this stuff is really really important +but it's not going to get you very far + + align:start position:0% +but it's not going to get you very far + + + align:start position:0% +but it's not going to get you very far +if you don't know all the other stuff + + align:start position:0% +if you don't know all the other stuff + + + align:start position:0% +if you don't know all the other stuff +you got to know all the other things but + + align:start position:0% +you got to know all the other things but + + + align:start position:0% +you got to know all the other things but +but i'm not i think the point is + + align:start position:0% +but i'm not i think the point is + + + align:start position:0% +but i'm not i think the point is +you do have to know this and again it's + + align:start position:0% +you do have to know this and again it's + + + align:start position:0% +you do have to know this and again it's +the current problem there's a lot of + + align:start position:0% +the current problem there's a lot of + + + align:start position:0% +the current problem there's a lot of +numbers actually + + align:start position:0% +numbers actually + + + align:start position:0% +numbers actually +exactly well it goes back to the point + + align:start position:0% +exactly well it goes back to the point + + + align:start position:0% +exactly well it goes back to the point +that i was making earlier which i think + + align:start position:0% +that i was making earlier which i think + + + align:start position:0% +that i was making earlier which i think +is is that + + align:start position:0% +is is that + + + align:start position:0% +is is that +genetics is moving from a field + + align:start position:0% +genetics is moving from a field + + + align:start position:0% +genetics is moving from a field +where + + align:start position:0% +where + + + align:start position:0% +where +genetics were generalists to a field + + align:start position:0% +genetics were generalists to a field + + + align:start position:0% +genetics were generalists to a field +where + + align:start position:0% +where + + + align:start position:0% +where +geneticists are specialists you get + + align:start position:0% +geneticists are specialists you get + + + align:start position:0% +geneticists are specialists you get +people who specialize in respiratory + + align:start position:0% +people who specialize in respiratory + + + align:start position:0% +people who specialize in respiratory +genetics cardiovascular genetics obesity + + align:start position:0% +genetics cardiovascular genetics obesity + + + align:start position:0% +genetics cardiovascular genetics obesity +genetics diabetes genetics the days of + + align:start position:0% +genetics diabetes genetics the days of + + + align:start position:0% +genetics diabetes genetics the days of +sort of the person that can roam around + + align:start position:0% +sort of the person that can roam around + + + align:start position:0% +sort of the person that can roam around +and do all of these things no no no i + + align:start position:0% +and do all of these things no no no i + + + align:start position:0% +and do all of these things no no no i +don't think that's going to happen + + align:start position:0% +don't think that's going to happen + + + align:start position:0% +don't think that's going to happen +uh in five years six years you're gonna + + align:start position:0% +uh in five years six years you're gonna + + + align:start position:0% +uh in five years six years you're gonna +have to be able to go in there and focus + + align:start position:0% +have to be able to go in there and focus + + + align:start position:0% +have to be able to go in there and focus +on a specific disease because it's going + + align:start position:0% +on a specific disease because it's going + + + align:start position:0% +on a specific disease because it's going +to be too complicated for you to be able + + align:start position:0% +to be too complicated for you to be able + + + align:start position:0% +to be too complicated for you to be able +to do otherwise + + align:start position:0% +to do otherwise + + + align:start position:0% +to do otherwise +then you've got this other type of + + align:start position:0% +then you've got this other type of + + + align:start position:0% +then you've got this other type of +phenotypes where you can say well + + align:start position:0% +phenotypes where you can say well + + + align:start position:0% +phenotypes where you can say well +okay we want to look at asthma + + align:start position:0% +okay we want to look at asthma + + + align:start position:0% +okay we want to look at asthma +but what about looking at intermediate + + align:start position:0% +but what about looking at intermediate + + + align:start position:0% +but what about looking at intermediate +phenotypes + + align:start position:0% +phenotypes + + + align:start position:0% +phenotypes +so give me some examples of an + + align:start position:0% +so give me some examples of an + + + align:start position:0% +so give me some examples of an +intermediate phenotype related to my + + align:start position:0% +intermediate phenotype related to my + + + align:start position:0% +intermediate phenotype related to my +disease of interest what would be an + + align:start position:0% +disease of interest what would be an + + + align:start position:0% +disease of interest what would be an +intermediate phenotype + + align:start position:0% + + + + align:start position:0% + +absolutely fev1 what else + + align:start position:0% + + + + align:start position:0% + +i had it up on a number of slides so ige + + align:start position:0% +i had it up on a number of slides so ige + + + align:start position:0% +i had it up on a number of slides so ige +level right the measure of allergy skin + + align:start position:0% +level right the measure of allergy skin + + + align:start position:0% +level right the measure of allergy skin +test reactivity airways responsiveness + + align:start position:0% +test reactivity airways responsiveness + + + align:start position:0% +test reactivity airways responsiveness +um + + align:start position:0% + + + + align:start position:0% + +symptom score sputum production + + align:start position:0% +symptom score sputum production + + + align:start position:0% +symptom score sputum production +i mean the uh uh exhale then oh i mean + + align:start position:0% +i mean the uh uh exhale then oh i mean + + + align:start position:0% +i mean the uh uh exhale then oh i mean +the list goes on and on and on you can + + align:start position:0% +the list goes on and on and on you can + + + align:start position:0% +the list goes on and on and on you can +create hundreds + + align:start position:0% +create hundreds + + + align:start position:0% +create hundreds +so + + align:start position:0% +so + + + align:start position:0% +so +for obesity you could be looking at + + align:start position:0% +for obesity you could be looking at + + + align:start position:0% +for obesity you could be looking at +um + + align:start position:0% + + + + align:start position:0% + +body mass index as the primary phenotype + + align:start position:0% +body mass index as the primary phenotype + + + align:start position:0% +body mass index as the primary phenotype +to define + + align:start position:0% +to define + + + align:start position:0% +to define +obesity but then you could look at + + align:start position:0% +obesity but then you could look at + + + align:start position:0% +obesity but then you could look at +absolute fat mass or percent body fat or + + align:start position:0% +absolute fat mass or percent body fat or + + + align:start position:0% +absolute fat mass or percent body fat or +waist hip ratio or + + align:start position:0% +waist hip ratio or + + + align:start position:0% +waist hip ratio or +insulin resistance or + + align:start position:0% + + + + align:start position:0% + +do ct scans of somebody's abdominal fat + + align:start position:0% +do ct scans of somebody's abdominal fat + + + align:start position:0% +do ct scans of somebody's abdominal fat +deposition i mean there's a million + + align:start position:0% +deposition i mean there's a million + + + align:start position:0% +deposition i mean there's a million +different ways of potentially going at + + align:start position:0% +different ways of potentially going at + + + align:start position:0% +different ways of potentially going at +this the advantage here is is that + + align:start position:0% +this the advantage here is is that + + + align:start position:0% +this the advantage here is is that +sometimes these are more objective than + + align:start position:0% +sometimes these are more objective than + + + align:start position:0% +sometimes these are more objective than +sort of a subjective oh it's asthma it's + + align:start position:0% +sort of a subjective oh it's asthma it's + + + align:start position:0% +sort of a subjective oh it's asthma it's +not asthma um and it may be quote closer + + align:start position:0% +not asthma um and it may be quote closer + + + align:start position:0% +not asthma um and it may be quote closer +to the gene in the sense that you know + + align:start position:0% +to the gene in the sense that you know + + + align:start position:0% +to the gene in the sense that you know +you've got somebody's ige level you know + + align:start position:0% +you've got somebody's ige level you know + + + align:start position:0% +you've got somebody's ige level you know +you have some idea of sort of + + align:start position:0% +you have some idea of sort of + + + align:start position:0% +you have some idea of sort of +genes that determine that and it can be + + align:start position:0% +genes that determine that and it can be + + + align:start position:0% +genes that determine that and it can be +quantitative you can do a + + align:start position:0% +quantitative you can do a + + + align:start position:0% +quantitative you can do a +different + + align:start position:0% +different + + + align:start position:0% +different +approach + + align:start position:0% +approach + + + align:start position:0% +approach +statistically + + align:start position:0% +statistically + + + align:start position:0% +statistically +to quantitative traits then you can use + + align:start position:0% +to quantitative traits then you can use + + + align:start position:0% +to quantitative traits then you can use +if you're looking at binary traits + + align:start position:0% +if you're looking at binary traits + + + align:start position:0% +if you're looking at binary traits +like if someone comes in and + + align:start position:0% +like if someone comes in and + + + align:start position:0% +like if someone comes in and +you look at them and say okay this + + align:start position:0% +you look at them and say okay this + + + align:start position:0% +you look at them and say okay this +person has + + align:start position:0% +person has + + + align:start position:0% +person has +some form of ask + + align:start position:0% +some form of ask + + + align:start position:0% +some form of ask +difficulty + + align:start position:0% + + + + align:start position:0% + +intermediate phenotypes and that + + align:start position:0% +intermediate phenotypes and that + + + align:start position:0% +intermediate phenotypes and that +that correlates them with like narrowing + + align:start position:0% +that correlates them with like narrowing + + + align:start position:0% +that correlates them with like narrowing +the diagnosis from okay you don't really + + align:start position:0% +the diagnosis from okay you don't really + + + align:start position:0% +the diagnosis from okay you don't really +have or you have this so you have this + + align:start position:0% +have or you have this so you have this + + + align:start position:0% +have or you have this so you have this +type of basketball is that + + align:start position:0% +type of basketball is that + + + align:start position:0% +type of basketball is that +well it's it's it's it's it's it it + + align:start position:0% +well it's it's it's it's it's it it + + + align:start position:0% +well it's it's it's it's it's it it +the way i prefer to think about it and i + + align:start position:0% +the way i prefer to think about it and i + + + align:start position:0% +the way i prefer to think about it and i +think it's probably a better way for you + + align:start position:0% +think it's probably a better way for you + + + align:start position:0% +think it's probably a better way for you +to think about it is is it + + align:start position:0% +to think about it is is it + + + align:start position:0% +to think about it is is it +you got to get away from this is where + + align:start position:0% +you got to get away from this is where + + + align:start position:0% +you got to get away from this is where +thinking like a doctor and a clinician + + align:start position:0% +thinking like a doctor and a clinician + + + align:start position:0% +thinking like a doctor and a clinician +is bad in the world of clinical medicine + + align:start position:0% +is bad in the world of clinical medicine + + + align:start position:0% +is bad in the world of clinical medicine +it's just like religion + + align:start position:0% +it's just like religion + + + align:start position:0% +it's just like religion +you either have the disease or you don't + + align:start position:0% +you either have the disease or you don't + + + align:start position:0% +you either have the disease or you don't +there's no such thing as being a little + + align:start position:0% +there's no such thing as being a little + + + align:start position:0% +there's no such thing as being a little +bit pregnant you're pregnant or you're + + align:start position:0% +bit pregnant you're pregnant or you're + + + align:start position:0% +bit pregnant you're pregnant or you're +not pregnant okay + + align:start position:0% +not pregnant okay + + + align:start position:0% +not pregnant okay +you have + + align:start position:0% +you have + + + align:start position:0% +you have +you have to have bypass surgery or you + + align:start position:0% +you have to have bypass surgery or you + + + align:start position:0% +you have to have bypass surgery or you +don't + + align:start position:0% +don't + + + align:start position:0% +don't +clinicians live in a binary world + + align:start position:0% +clinicians live in a binary world + + + align:start position:0% +clinicians live in a binary world +real scientists live in the world of + + align:start position:0% +real scientists live in the world of + + + align:start position:0% +real scientists live in the world of +continuous distributions okay + + align:start position:0% +continuous distributions okay + + + align:start position:0% +continuous distributions okay +so so you you know you can have + + align:start position:0% +so so you you know you can have + + + align:start position:0% +so so you you know you can have +uh uh uh + + align:start position:0% +uh uh uh + + + align:start position:0% +uh uh uh +when when are you fat are you fat with a + + align:start position:0% +when when are you fat are you fat with a + + + align:start position:0% +when when are you fat are you fat with a +body mass index of 23 24 25 + + align:start position:0% +body mass index of 23 24 25 + + + align:start position:0% +body mass index of 23 24 25 +26 when you hi when do you have high + + align:start position:0% +26 when you hi when do you have high + + + align:start position:0% +26 when you hi when do you have high +blood pressure when it's 130 over 80 or + + align:start position:0% +blood pressure when it's 130 over 80 or + + + align:start position:0% +blood pressure when it's 130 over 80 or +140 over 90 or + + align:start position:0% +140 over 90 or + + + align:start position:0% +140 over 90 or +you know you know when when is that so i + + align:start position:0% +you know you know when when is that so i + + + align:start position:0% +you know you know when when is that so i +think that and the other thing is is + + align:start position:0% +think that and the other thing is is + + + align:start position:0% +think that and the other thing is is +that the way to think about these is + + align:start position:0% +that the way to think about these is + + + align:start position:0% +that the way to think about these is +kind of like overlapping venn diagrams + + align:start position:0% +kind of like overlapping venn diagrams + + + align:start position:0% +kind of like overlapping venn diagrams +the clinical phenotype is actually + + align:start position:0% +the clinical phenotype is actually + + + align:start position:0% +the clinical phenotype is actually +a composite of these overlapping venn + + align:start position:0% +a composite of these overlapping venn + + + align:start position:0% +a composite of these overlapping venn +diagrams that are all have separate + + align:start position:0% +diagrams that are all have separate + + + align:start position:0% +diagrams that are all have separate +genetic determinants + + align:start position:0% +genetic determinants + + + align:start position:0% +genetic determinants +and + + align:start position:0% +and + + + align:start position:0% +and +things that + + align:start position:0% +things that + + + align:start position:0% +things that +contribute to them separate genetic and + + align:start position:0% +contribute to them separate genetic and + + + align:start position:0% +contribute to them separate genetic and +environ sort of like dissecting a layer + + align:start position:0% +environ sort of like dissecting a layer + + + align:start position:0% +environ sort of like dissecting a layer +and peeling an onion where you've got + + align:start position:0% +and peeling an onion where you've got + + + align:start position:0% +and peeling an onion where you've got +all these different uh um + + align:start position:0% +all these different uh um + + + align:start position:0% +all these different uh um +different things but i think in in many + + align:start position:0% +different things but i think in in many + + + align:start position:0% +different things but i think in in many +ways + + align:start position:0% + + + + align:start position:0% + +being a clinician can help + + align:start position:0% +being a clinician can help + + + align:start position:0% +being a clinician can help +you as a research scientist but in some + + align:start position:0% +you as a research scientist but in some + + + align:start position:0% +you as a research scientist but in some +ways it can also hurt because + + align:start position:0% +ways it can also hurt because + + + align:start position:0% +ways it can also hurt because +you start to think in these absolute + + align:start position:0% +you start to think in these absolute + + + align:start position:0% +you start to think in these absolute +terms so i think the better way to think + + align:start position:0% +terms so i think the better way to think + + + align:start position:0% +terms so i think the better way to think +about it is is that + + align:start position:0% + + + + align:start position:0% + +these intermediate phenotypes overlapped + + align:start position:0% +these intermediate phenotypes overlapped + + + align:start position:0% +these intermediate phenotypes overlapped +create clinical phenotypes and + + align:start position:0% +create clinical phenotypes and + + + align:start position:0% +create clinical phenotypes and +yes you're what you're trying to do is + + align:start position:0% +yes you're what you're trying to do is + + + align:start position:0% +yes you're what you're trying to do is +get + + align:start position:0% +get + + + align:start position:0% +get +stratify in some way or + + align:start position:0% +stratify in some way or + + + align:start position:0% +stratify in some way or +classify people in some way so you're + + align:start position:0% +classify people in some way so you're + + + align:start position:0% +classify people in some way so you're +you're you're creating homogeneity so + + align:start position:0% +you're you're creating homogeneity so + + + align:start position:0% +you're you're creating homogeneity so +that you can actually identify the + + align:start position:0% +that you can actually identify the + + + align:start position:0% +that you can actually identify the +genetic determinants of + + align:start position:0% +genetic determinants of + + + align:start position:0% +genetic determinants of +of a disease or an intermediate + + align:start position:0% +of a disease or an intermediate + + + align:start position:0% +of a disease or an intermediate +phenotype so you want to go in that + + align:start position:0% +phenotype so you want to go in that + + + align:start position:0% +phenotype so you want to go in that +direction but but most of these things + + align:start position:0% +direction but but most of these things + + + align:start position:0% +direction but but most of these things +lack + + align:start position:0% +lack + + + align:start position:0% +lack +sufficient sensitivity and specificity + + align:start position:0% +sufficient sensitivity and specificity + + + align:start position:0% +sufficient sensitivity and specificity +to really be a uh + + align:start position:0% +to really be a uh + + + align:start position:0% +to really be a uh +terribly helpful this is just a list of + + align:start position:0% +terribly helpful this is just a list of + + + align:start position:0% +terribly helpful this is just a list of +some of the phenotypes that people have + + align:start position:0% +some of the phenotypes that people have + + + align:start position:0% +some of the phenotypes that people have +looked at in asthma i've starred some of + + align:start position:0% +looked at in asthma i've starred some of + + + align:start position:0% +looked at in asthma i've starred some of +the ones that + + align:start position:0% +the ones that + + + align:start position:0% +the ones that +people have focused on in terms of + + align:start position:0% +people have focused on in terms of + + + align:start position:0% +people have focused on in terms of +linkage peaks that have actually been + + align:start position:0% +linkage peaks that have actually been + + + align:start position:0% +linkage peaks that have actually been +identified + + align:start position:0% + + + + align:start position:0% + +but this is interesting because there's + + align:start position:0% +but this is interesting because there's + + + align:start position:0% +but this is interesting because there's +clearly a bias in the literature because + + align:start position:0% +clearly a bias in the literature because + + + align:start position:0% +clearly a bias in the literature because +there's a whole bunch of these other + + align:start position:0% +there's a whole bunch of these other + + + align:start position:0% +there's a whole bunch of these other +phenotypes where + + align:start position:0% +phenotypes where + + + align:start position:0% +phenotypes where +you could just disease and i could + + align:start position:0% +you could just disease and i could + + + align:start position:0% +you could just disease and i could +create a list 30 more of these where + + align:start position:0% +create a list 30 more of these where + + + align:start position:0% +create a list 30 more of these where +people haven't looked it so so this just + + align:start position:0% +people haven't looked it so so this just + + + align:start position:0% +people haven't looked it so so this just +gets to the point that there's plenty of + + align:start position:0% +gets to the point that there's plenty of + + + align:start position:0% +gets to the point that there's plenty of +work here for anybody who wants to do + + align:start position:0% +work here for anybody who wants to do + + + align:start position:0% +work here for anybody who wants to do +this stuff because + + align:start position:0% +this stuff because + + + align:start position:0% +this stuff because +you can go out and i got a junior person + + align:start position:0% +you can go out and i got a junior person + + + align:start position:0% +you can go out and i got a junior person +in my lab he's got a bunch of phenotypes + + align:start position:0% +in my lab he's got a bunch of phenotypes + + + align:start position:0% +in my lab he's got a bunch of phenotypes +that he's really interested in and he's + + align:start position:0% +that he's really interested in and he's + + + align:start position:0% +that he's really interested in and he's +going to go out and he's going to + + align:start position:0% +going to go out and he's going to + + + align:start position:0% +going to go out and he's going to +determine their heritability and then + + align:start position:0% +determine their heritability and then + + + align:start position:0% +determine their heritability and then +he's going to write another grant and + + align:start position:0% +he's going to write another grant and + + + align:start position:0% +he's going to write another grant and +he's going to map the genes for him and + + align:start position:0% +he's going to map the genes for him and + + + align:start position:0% +he's going to map the genes for him and +so on and so forth because he he wants + + align:start position:0% +so on and so forth because he he wants + + + align:start position:0% +so on and so forth because he he wants +to have his own little + + align:start position:0% +to have his own little + + + align:start position:0% +to have his own little +area to sort of work + + align:start position:0% +area to sort of work + + + align:start position:0% +area to sort of work +on so then the next thing so now + + align:start position:0% +on so then the next thing so now + + + align:start position:0% +on so then the next thing so now +we're kind of at the point where you you + + align:start position:0% +we're kind of at the point where you you + + + align:start position:0% +we're kind of at the point where you you +know you gotta i gotta move a little + + align:start position:0% +know you gotta i gotta move a little + + + align:start position:0% +know you gotta i gotta move a little +faster we're not gonna make our way + + align:start position:0% +faster we're not gonna make our way + + + align:start position:0% +faster we're not gonna make our way +through this but you gotta have a study + + align:start position:0% +through this but you gotta have a study + + + align:start position:0% +through this but you gotta have a study +design and there's a bunch of different + + align:start position:0% +design and there's a bunch of different + + + align:start position:0% +design and there's a bunch of different +ways of doing this okay + + align:start position:0% +ways of doing this okay + + + align:start position:0% +ways of doing this okay +you can do linkage you can do + + align:start position:0% +you can do linkage you can do + + + align:start position:0% +you can do linkage you can do +association yeah and and + + align:start position:0% +association yeah and and + + + align:start position:0% +association yeah and and +amongst the linkage studies you can do + + align:start position:0% +amongst the linkage studies you can do + + + align:start position:0% +amongst the linkage studies you can do +allele sharing uh uh um + + align:start position:0% +allele sharing uh uh um + + + align:start position:0% +allele sharing uh uh um +methods which are distribution free or + + align:start position:0% +methods which are distribution free or + + + align:start position:0% +methods which are distribution free or +you can uh um + + align:start position:0% + + + + align:start position:0% + +do sort of um + + align:start position:0% +do sort of um + + + align:start position:0% +do sort of um +continuous distributions and and focus + + align:start position:0% +continuous distributions and and focus + + + align:start position:0% +continuous distributions and and focus +on that + + align:start position:0% +on that + + + align:start position:0% +on that +there are two types of genetic + + align:start position:0% +there are two types of genetic + + + align:start position:0% +there are two types of genetic +association studies the family based and + + align:start position:0% +association studies the family based and + + + align:start position:0% +association studies the family based and +the case control important point here is + + align:start position:0% +the case control important point here is + + + align:start position:0% +the case control important point here is +is that they're very different + + align:start position:0% +is that they're very different + + + align:start position:0% +is that they're very different +you know here you have the genotype + + align:start position:0% +you know here you have the genotype + + + align:start position:0% +you know here you have the genotype +uh three people + + align:start position:0% +uh three people + + + align:start position:0% +uh three people +here you have to genotype only two + + align:start position:0% +here you have to genotype only two + + + align:start position:0% +here you have to genotype only two +people + + align:start position:0% +people + + + align:start position:0% +people +different hypotheses + + align:start position:0% +different hypotheses + + + align:start position:0% +different hypotheses +here you're looking at the + + align:start position:0% +here you're looking at the + + + align:start position:0% +here you're looking at the +alleles or the + + align:start position:0% +alleles or the + + + align:start position:0% +alleles or the +genotypes + + align:start position:0% +genotypes + + + align:start position:0% +genotypes +in the cases relative to the controls + + align:start position:0% +in the cases relative to the controls + + + align:start position:0% +in the cases relative to the controls +it's the little frequency of the + + align:start position:0% +it's the little frequency of the + + + align:start position:0% +it's the little frequency of the +genotype frequency in the cases versus + + align:start position:0% +genotype frequency in the cases versus + + + align:start position:0% +genotype frequency in the cases versus +the controls here you're looking at + + align:start position:0% + + + + align:start position:0% + +transmitted alleles from a heterozygous + + align:start position:0% +transmitted alleles from a heterozygous + + + align:start position:0% +transmitted alleles from a heterozygous +parent to an affected offspring + + align:start position:0% +parent to an affected offspring + + + align:start position:0% +parent to an affected offspring +so very different hypotheses different + + align:start position:0% +so very different hypotheses different + + + align:start position:0% +so very different hypotheses different +study designs + + align:start position:0% +study designs + + + align:start position:0% +study designs +and + + align:start position:0% +and + + + align:start position:0% +and +important thing to recognize is that in + + align:start position:0% +important thing to recognize is that in + + + align:start position:0% +important thing to recognize is that in +any association study + + align:start position:0% +any association study + + + align:start position:0% +any association study +um the association between a variant and + + align:start position:0% +um the association between a variant and + + + align:start position:0% +um the association between a variant and +a phenotype can be due to a causal + + align:start position:0% +a phenotype can be due to a causal + + + align:start position:0% +a phenotype can be due to a causal +relationship it can be the linkage + + align:start position:0% +relationship it can be the linkage + + + align:start position:0% +relationship it can be the linkage +of disequilibrium or it can be due to + + align:start position:0% +of disequilibrium or it can be due to + + + align:start position:0% +of disequilibrium or it can be due to +population admixture which means that + + align:start position:0% +population admixture which means that + + + align:start position:0% +population admixture which means that +usually in the context of a case control + + align:start position:0% +usually in the context of a case control + + + align:start position:0% +usually in the context of a case control +study not a family-based study you've + + align:start position:0% +study not a family-based study you've + + + align:start position:0% +study not a family-based study you've +got different allele frequencies + + align:start position:0% +got different allele frequencies + + + align:start position:0% +got different allele frequencies +segregating in the cases and the + + align:start position:0% +segregating in the cases and the + + + align:start position:0% +segregating in the cases and the +controls because you've got different + + align:start position:0% +controls because you've got different + + + align:start position:0% +controls because you've got different +population histories + + align:start position:0% +population histories + + + align:start position:0% +population histories +evolutionary histories + + align:start position:0% +evolutionary histories + + + align:start position:0% +evolutionary histories +uh uh that have determined those allele + + align:start position:0% +uh uh that have determined those allele + + + align:start position:0% +uh uh that have determined those allele +frequencies so the most extreme example + + align:start position:0% +frequencies so the most extreme example + + + align:start position:0% +frequencies so the most extreme example +would be i had a thousand italian cases + + align:start position:0% +would be i had a thousand italian cases + + + align:start position:0% +would be i had a thousand italian cases +of asthma and i'm comparing it to a + + align:start position:0% +of asthma and i'm comparing it to a + + + align:start position:0% +of asthma and i'm comparing it to a +thousand swiss controls + + align:start position:0% +thousand swiss controls + + + align:start position:0% +thousand swiss controls +uh uh who don't have asthma and even + + align:start position:0% +uh uh who don't have asthma and even + + + align:start position:0% +uh uh who don't have asthma and even +though these two groups are predominant + + align:start position:0% +though these two groups are predominant + + + align:start position:0% +though these two groups are predominant +or caucasian + + align:start position:0% +or caucasian + + + align:start position:0% +or caucasian +their evolutionary history may be + + align:start position:0% +their evolutionary history may be + + + align:start position:0% +their evolutionary history may be +different and the allele frequencies may + + align:start position:0% +different and the allele frequencies may + + + align:start position:0% +different and the allele frequencies may +be different as a result of that so this + + align:start position:0% +be different as a result of that so this + + + align:start position:0% +be different as a result of that so this +is even within an ethnic group + + align:start position:0% +is even within an ethnic group + + + align:start position:0% +is even within an ethnic group +you can get these different allele + + align:start position:0% +you can get these different allele + + + align:start position:0% +you can get these different allele +frequencies and this is because + + align:start position:0% + + + + align:start position:0% + +ethnicity or self-designated ethnicity + + align:start position:0% +ethnicity or self-designated ethnicity + + + align:start position:0% +ethnicity or self-designated ethnicity +is + + align:start position:0% +is + + + align:start position:0% +is +only a weak + + align:start position:0% +only a weak + + + align:start position:0% +only a weak +predictor of evolutionary history + + align:start position:0% +predictor of evolutionary history + + + align:start position:0% +predictor of evolutionary history +i know what's your example or remarkable + + align:start position:0% +i know what's your example or remarkable + + + align:start position:0% +i know what's your example or remarkable +example so you've compared a link + + align:start position:0% +example so you've compared a link + + + align:start position:0% +example so you've compared a link +an association study for costa rica + + align:start position:0% +an association study for costa rica + + + align:start position:0% +an association study for costa rica +between + + align:start position:0% +between + + + align:start position:0% +between +germans and italians with two + + align:start position:0% +germans and italians with two + + + align:start position:0% +germans and italians with two +populations sure enough we find a + + align:start position:0% +populations sure enough we find a + + + align:start position:0% +populations sure enough we find a +linkage association between pasta eating + + align:start position:0% +linkage association between pasta eating + + + align:start position:0% +linkage association between pasta eating +and + + align:start position:0% +and + + + align:start position:0% +and +some peaks + + align:start position:0% +some peaks + + + align:start position:0% +some peaks +um a genome because in fact we'd be + + align:start position:0% +um a genome because in fact we'd be + + + align:start position:0% +um a genome because in fact we'd be +looking for is linkage to the fact that + + align:start position:0% +looking for is linkage to the fact that + + + align:start position:0% +looking for is linkage to the fact that +you're in italian + + align:start position:0% +you're in italian + + + align:start position:0% +you're in italian +and just by the fact that the italians + + align:start position:0% +and just by the fact that the italians + + + align:start position:0% +and just by the fact that the italians +have a distinct distribution of + + align:start position:0% +have a distinct distribution of + + + align:start position:0% +have a distinct distribution of +polymorphisms then the germans gonna + + align:start position:0% +polymorphisms then the germans gonna + + + align:start position:0% +polymorphisms then the germans gonna +create this pasta association when in + + align:start position:0% +create this pasta association when in + + + align:start position:0% +create this pasta association when in +fact when you're looking at different + + align:start position:0% +fact when you're looking at different + + + align:start position:0% +fact when you're looking at different +populations + + align:start position:0% +populations + + + align:start position:0% +populations +so these + + align:start position:0% +so these + + + align:start position:0% +so these +uh some of the guys in my lab wrote an + + align:start position:0% +uh some of the guys in my lab wrote an + + + align:start position:0% +uh some of the guys in my lab wrote an +article + + align:start position:0% +article + + + align:start position:0% +article +demonstrating all of the potential + + align:start position:0% +demonstrating all of the potential + + + align:start position:0% +demonstrating all of the potential +problems in the case control type of + + align:start position:0% +problems in the case control type of + + + align:start position:0% +problems in the case control type of +uh a genetic association study and one + + align:start position:0% +uh a genetic association study and one + + + align:start position:0% +uh a genetic association study and one +of the things that's really impressive + + align:start position:0% +of the things that's really impressive + + + align:start position:0% +of the things that's really impressive +about this paper in science is is it we + + align:start position:0% +about this paper in science is is it we + + + align:start position:0% +about this paper in science is is it we +all use genetic association + + align:start position:0% +all use genetic association + + + align:start position:0% +all use genetic association +as part of the fine mapping process to + + align:start position:0% +as part of the fine mapping process to + + + align:start position:0% +as part of the fine mapping process to +map a linkage peak + + align:start position:0% +map a linkage peak + + + align:start position:0% +map a linkage peak +but + + align:start position:0% +but + + + align:start position:0% +but +this is very important but + + align:start position:0% + + + + align:start position:0% + +because even if you can get rid of the + + align:start position:0% +because even if you can get rid of the + + + align:start position:0% +because even if you can get rid of the +population admixture problem + + align:start position:0% +population admixture problem + + + align:start position:0% +population admixture problem +linkage this equilibrium is always an + + align:start position:0% +linkage this equilibrium is always an + + + align:start position:0% +linkage this equilibrium is always an +issue and so you're never going to know + + align:start position:0% +issue and so you're never going to know + + + align:start position:0% +issue and so you're never going to know +for sure if you're + + align:start position:0% +for sure if you're + + + align:start position:0% +for sure if you're +at the gene + + align:start position:0% +at the gene + + + align:start position:0% +at the gene +or you're just close by to it + + align:start position:0% +or you're just close by to it + + + align:start position:0% +or you're just close by to it +and so you're gonna have to have + + align:start position:0% +and so you're gonna have to have + + + align:start position:0% +and so you're gonna have to have +something else + + align:start position:0% +something else + + + align:start position:0% +something else +to show that you've actually found the + + align:start position:0% +to show that you've actually found the + + + align:start position:0% +to show that you've actually found the +gene you're not getting into science + + align:start position:0% +gene you're not getting into science + + + align:start position:0% +gene you're not getting into science +just with genetic association + + align:start position:0% +just with genetic association + + + align:start position:0% +just with genetic association +okay and so the people in the paper + + align:start position:0% +okay and so the people in the paper + + + align:start position:0% +okay and so the people in the paper +that's coming out this week + + align:start position:0% +that's coming out this week + + + align:start position:0% +that's coming out this week +they have + + align:start position:0% +they have + + + align:start position:0% +they have +expressed the gene + + align:start position:0% +expressed the gene + + + align:start position:0% +expressed the gene +in + + align:start position:0% +in + + + align:start position:0% +in +bronchial tissue they've + + align:start position:0% + + + + align:start position:0% + +done immunohistochemistry to show that + + align:start position:0% +done immunohistochemistry to show that + + + align:start position:0% +done immunohistochemistry to show that +the gene is expressed in epithelium uh + + align:start position:0% +the gene is expressed in epithelium uh + + + align:start position:0% +the gene is expressed in epithelium uh +they replicated their results in a + + align:start position:0% +they replicated their results in a + + + align:start position:0% +they replicated their results in a +different population et cetera et cetera + + align:start position:0% +different population et cetera et cetera + + + align:start position:0% +different population et cetera et cetera +so + + align:start position:0% +so + + + align:start position:0% +so +the the thing about the candidate + + align:start position:0% +the the thing about the candidate + + + align:start position:0% +the the thing about the candidate +about about the case control studies and + + align:start position:0% +about about the case control studies and + + + align:start position:0% +about about the case control studies and +about even family based association is + + align:start position:0% +about even family based association is + + + align:start position:0% +about even family based association is +that these studies are really easy to do + + align:start position:0% +that these studies are really easy to do + + + align:start position:0% +that these studies are really easy to do +and so there's lots of them in the + + align:start position:0% +and so there's lots of them in the + + + align:start position:0% +and so there's lots of them in the +literature so it's really important for + + align:start position:0% +literature so it's really important for + + + align:start position:0% +literature so it's really important for +you to know you know going back to this + + align:start position:0% +you to know you know going back to this + + + align:start position:0% +you to know you know going back to this +slide it's really important for you to + + align:start position:0% +slide it's really important for you to + + + align:start position:0% +slide it's really important for you to +sort of know + + align:start position:0% +sort of know + + + align:start position:0% +sort of know +these potential problems + + align:start position:0% +these potential problems + + + align:start position:0% +these potential problems +because + + align:start position:0% +because + + + align:start position:0% +because +you want to be able to read this + + align:start position:0% +you want to be able to read this + + + align:start position:0% +you want to be able to read this +literature and say yeah these guys + + align:start position:0% +literature and say yeah these guys + + + align:start position:0% +literature and say yeah these guys +really found something or maybe they + + align:start position:0% +really found something or maybe they + + + align:start position:0% +really found something or maybe they +didn't + + align:start position:0% +didn't + + + align:start position:0% +didn't +so + + align:start position:0% +so + + + align:start position:0% +so +the advantages of this candidate + + align:start position:0% +the advantages of this candidate + + + align:start position:0% +the advantages of this candidate +gene thing is is that it's + + align:start position:0% +gene thing is is that it's + + + align:start position:0% +gene thing is is that it's +cheap and easy the the the the + + align:start position:0% +cheap and easy the the the the + + + align:start position:0% +cheap and easy the the the the +you compare remember i said that now + + align:start position:0% +you compare remember i said that now + + + align:start position:0% +you compare remember i said that now +four positionally cloned genes that have + + align:start position:0% +four positionally cloned genes that have + + + align:start position:0% +four positionally cloned genes that have +used + + align:start position:0% +used + + + align:start position:0% +used +this type of genome screen + + align:start position:0% +this type of genome screen + + + align:start position:0% +this type of genome screen +approach + + align:start position:0% + + + + align:start position:0% + +four + + align:start position:0% +four + + + align:start position:0% +four +that have been identified since the + + align:start position:0% +that have been identified since the + + + align:start position:0% +that have been identified since the +human genome was mapped in 1996 well you + + align:start position:0% +human genome was mapped in 1996 well you + + + align:start position:0% +human genome was mapped in 1996 well you +know that's + + align:start position:0% +know that's + + + align:start position:0% +know that's +seven years that's not even one gene a + + align:start position:0% +seven years that's not even one gene a + + + align:start position:0% +seven years that's not even one gene a +year that's pretty meek + + align:start position:0% +year that's pretty meek + + + align:start position:0% +year that's pretty meek +or weak + + align:start position:0% +or weak + + + align:start position:0% +or weak +that's because this is very + + align:start position:0% +that's because this is very + + + align:start position:0% +that's because this is very +expensive technologically intensive but + + align:start position:0% +expensive technologically intensive but + + + align:start position:0% +expensive technologically intensive but +the thing that's great about this is you + + align:start position:0% +the thing that's great about this is you + + + align:start position:0% +the thing that's great about this is you +come up with a novel gene at the end of + + align:start position:0% +come up with a novel gene at the end of + + + align:start position:0% +come up with a novel gene at the end of +the time so you know it's not dependent + + align:start position:0% +the time so you know it's not dependent + + + align:start position:0% +the time so you know it's not dependent +on what anybody knows about pathobiology + + align:start position:0% +on what anybody knows about pathobiology + + + align:start position:0% +on what anybody knows about pathobiology +so you could go this way you could say + + align:start position:0% +so you could go this way you could say + + + align:start position:0% +so you could go this way you could say +look i know + + align:start position:0% +look i know + + + align:start position:0% +look i know +that ige is important in asthma so i + + align:start position:0% +that ige is important in asthma so i + + + align:start position:0% +that ige is important in asthma so i +know that we ought to be screening + + align:start position:0% +know that we ought to be screening + + + align:start position:0% +know that we ought to be screening +il13 il4 l4 receptor + + align:start position:0% + + + + align:start position:0% + +ctla4 all of those genes in the pathway + + align:start position:0% +ctla4 all of those genes in the pathway + + + align:start position:0% +ctla4 all of those genes in the pathway +that determines ig makes sense right + + align:start position:0% +that determines ig makes sense right + + + align:start position:0% +that determines ig makes sense right +screen those genes because + + align:start position:0% +screen those genes because + + + align:start position:0% +screen those genes because +we've already said that people with + + align:start position:0% +we've already said that people with + + + align:start position:0% +we've already said that people with +asthma have high ig well + + align:start position:0% +asthma have high ig well + + + align:start position:0% +asthma have high ig well +you know you you check those genes and + + align:start position:0% +you know you you check those genes and + + + align:start position:0% +you know you you check those genes and +yeah in fact they are + + align:start position:0% +yeah in fact they are + + + align:start position:0% +yeah in fact they are +most of those genes are + + align:start position:0% +most of those genes are + + + align:start position:0% +most of those genes are +asthma + + align:start position:0% +asthma + + + align:start position:0% +asthma +allergy genes it's not kind of not real + + align:start position:0% +allergy genes it's not kind of not real + + + align:start position:0% +allergy genes it's not kind of not real +exciting though you know it's not like + + align:start position:0% +exciting though you know it's not like + + + align:start position:0% +exciting though you know it's not like +everybody's gonna jump up and say oh my + + align:start position:0% +everybody's gonna jump up and say oh my + + + align:start position:0% +everybody's gonna jump up and say oh my +god you know io13 is an asthma gene well + + align:start position:0% +god you know io13 is an asthma gene well + + + align:start position:0% +god you know io13 is an asthma gene well +you know molecular biologist says yeah + + align:start position:0% +you know molecular biologist says yeah + + + align:start position:0% +you know molecular biologist says yeah +well we knew that 10 years ago what's + + align:start position:0% +well we knew that 10 years ago what's + + + align:start position:0% +well we knew that 10 years ago what's +new + + align:start position:0% +new + + + align:start position:0% +new +what's great about that well + + align:start position:0% +what's great about that well + + + align:start position:0% +what's great about that well +i mean + + align:start position:0% +i mean + + + align:start position:0% +i mean +there are interesting things about it + + align:start position:0% +there are interesting things about it + + + align:start position:0% +there are interesting things about it +because you actually can get to the + + align:start position:0% +because you actually can get to the + + + align:start position:0% +because you actually can get to the +level it's going to change molecular + + align:start position:0% +level it's going to change molecular + + + align:start position:0% +level it's going to change molecular +biology too because you're actually + + align:start position:0% +biology too because you're actually + + + align:start position:0% +biology too because you're actually +going to get the level where you say + + align:start position:0% +going to get the level where you say + + + align:start position:0% +going to get the level where you say +well it's these three variants in the + + align:start position:0% +well it's these three variants in the + + + align:start position:0% +well it's these three variants in the +promoter it's this variant in exon one + + align:start position:0% +promoter it's this variant in exon one + + + align:start position:0% +promoter it's this variant in exon one +and it's this particular haplotype + + align:start position:0% +and it's this particular haplotype + + + align:start position:0% +and it's this particular haplotype +that's determining the effect on ige + + align:start position:0% +that's determining the effect on ige + + + align:start position:0% +that's determining the effect on ige +level so + + align:start position:0% +level so + + + align:start position:0% +level so +molecular biology is going to change + + align:start position:0% +molecular biology is going to change + + + align:start position:0% +molecular biology is going to change +because people aren't going to just be + + align:start position:0% +because people aren't going to just be + + + align:start position:0% +because people aren't going to just be +aren't going to get away with knocking + + align:start position:0% +aren't going to get away with knocking + + + align:start position:0% +aren't going to get away with knocking +out a gene or or looking at a whole + + align:start position:0% +out a gene or or looking at a whole + + + align:start position:0% +out a gene or or looking at a whole +gene effect they're going to actually + + align:start position:0% +gene effect they're going to actually + + + align:start position:0% +gene effect they're going to actually +have to go in there and determine + + align:start position:0% +have to go in there and determine + + + align:start position:0% +have to go in there and determine +the particular variants that are + + align:start position:0% +the particular variants that are + + + align:start position:0% +the particular variants that are +important + + align:start position:0% +important + + + align:start position:0% +important +in terms of the molecular mechanisms + + align:start position:0% +in terms of the molecular mechanisms + + + align:start position:0% +in terms of the molecular mechanisms +so i don't want to sort of then + + align:start position:0% +so i don't want to sort of then + + + align:start position:0% +so i don't want to sort of then +denigrate this because i this is we do + + align:start position:0% +denigrate this because i this is we do + + + align:start position:0% +denigrate this because i this is we do +all of us do a lot of this stuff + + align:start position:0% +all of us do a lot of this stuff + + + align:start position:0% +all of us do a lot of this stuff +to keep ourselves busy while we're + + align:start position:0% +to keep ourselves busy while we're + + + align:start position:0% +to keep ourselves busy while we're +trying to do these really big + + align:start position:0% +trying to do these really big + + + align:start position:0% +trying to do these really big +experiments that are very expensive and + + align:start position:0% +experiments that are very expensive and + + + align:start position:0% +experiments that are very expensive and +take a long time + + align:start position:0% +take a long time + + + align:start position:0% +take a long time +um skip that so let's talk a little bit + + align:start position:0% +um skip that so let's talk a little bit + + + align:start position:0% +um skip that so let's talk a little bit +about linkage linkage is this idea of + + align:start position:0% +about linkage linkage is this idea of + + + align:start position:0% +about linkage linkage is this idea of +you take these microsatellite markers + + align:start position:0% +you take these microsatellite markers + + + align:start position:0% +you take these microsatellite markers +all the way across the genome + + align:start position:0% +all the way across the genome + + + align:start position:0% +all the way across the genome +it's a property of families it's not a + + align:start position:0% +it's a property of families it's not a + + + align:start position:0% +it's a property of families it's not a +property of individuals and you're + + align:start position:0% +property of individuals and you're + + + align:start position:0% +property of individuals and you're +looking to see if there's a particular + + align:start position:0% +looking to see if there's a particular + + + align:start position:0% +looking to see if there's a particular +region of the genome contains a gene + + align:start position:0% +region of the genome contains a gene + + + align:start position:0% +region of the genome contains a gene +that's related to the phenotype of + + align:start position:0% +that's related to the phenotype of + + + align:start position:0% +that's related to the phenotype of +interest that's segregating uh in these + + align:start position:0% +interest that's segregating uh in these + + + align:start position:0% +interest that's segregating uh in these +families uh um + + align:start position:0% +families uh um + + + align:start position:0% +families uh um +uh uh uh + + align:start position:0% +uh uh uh + + + align:start position:0% +uh uh uh +uh + + align:start position:0% +uh + + + align:start position:0% +uh +using identity by dissent so + + align:start position:0% +using identity by dissent so + + + align:start position:0% +using identity by dissent so +what you do is you know you have some + + align:start position:0% +what you do is you know you have some + + + align:start position:0% +what you do is you know you have some +extended pedigree like this + + align:start position:0% +extended pedigree like this + + + align:start position:0% +extended pedigree like this +what you could do + + align:start position:0% +what you could do + + + align:start position:0% +what you could do +is you could + + align:start position:0% +is you could + + + align:start position:0% +is you could +do segregation analysis to develop a + + align:start position:0% +do segregation analysis to develop a + + + align:start position:0% +do segregation analysis to develop a +model + + align:start position:0% +model + + + align:start position:0% +model +to see how the disease is actually + + align:start position:0% +to see how the disease is actually + + + align:start position:0% +to see how the disease is actually +segregating in this population but + + align:start position:0% +segregating in this population but + + + align:start position:0% +segregating in this population but +that's pretty difficult for complex + + align:start position:0% +that's pretty difficult for complex + + + align:start position:0% +that's pretty difficult for complex +traits it's not easy to do + + align:start position:0% +traits it's not easy to do + + + align:start position:0% +traits it's not easy to do +um + + align:start position:0% +um + + + align:start position:0% +um +you could also + + align:start position:0% +you could also + + + align:start position:0% +you could also +use this approach the allele sharing + + align:start position:0% +use this approach the allele sharing + + + align:start position:0% +use this approach the allele sharing +approach which assumes no mode of + + align:start position:0% +approach which assumes no mode of + + + align:start position:0% +approach which assumes no mode of +inheritance just says we collected a + + align:start position:0% +inheritance just says we collected a + + + align:start position:0% +inheritance just says we collected a +whole bunch of sib pairs who are + + align:start position:0% +whole bunch of sib pairs who are + + + align:start position:0% +whole bunch of sib pairs who are +affected and we're going to test whether + + align:start position:0% +affected and we're going to test whether + + + align:start position:0% +affected and we're going to test whether +these affected + + align:start position:0% +these affected + + + align:start position:0% +these affected +relatives have inherited a region + + align:start position:0% +relatives have inherited a region + + + align:start position:0% +relatives have inherited a region +of the genome identity by descent more + + align:start position:0% +of the genome identity by descent more + + + align:start position:0% +of the genome identity by descent more +often than expected under random + + align:start position:0% +often than expected under random + + + align:start position:0% +often than expected under random +mendelian segregation and the nice thing + + align:start position:0% +mendelian segregation and the nice thing + + + align:start position:0% +mendelian segregation and the nice thing +about this is that it's easy but it's + + align:start position:0% +about this is that it's easy but it's + + + align:start position:0% +about this is that it's easy but it's +not very powerful i mean the problem is + + align:start position:0% +not very powerful i mean the problem is + + + align:start position:0% +not very powerful i mean the problem is +you need a lot of sid pairs + + align:start position:0% +you need a lot of sid pairs + + + align:start position:0% +you need a lot of sid pairs +uh and even then even with over 300 sid + + align:start position:0% +uh and even then even with over 300 sid + + + align:start position:0% +uh and even then even with over 300 sid +pairs you don't get such great power um + + align:start position:0% +pairs you don't get such great power um + + + align:start position:0% +pairs you don't get such great power um +using this approach so uh um + + align:start position:0% +using this approach so uh um + + + align:start position:0% +using this approach so uh um +power goes up + + align:start position:0% +power goes up + + + align:start position:0% +power goes up +if the disease is more heritable + + align:start position:0% +if the disease is more heritable + + + align:start position:0% +if the disease is more heritable +um and you can do with less sid pairs + + align:start position:0% +um and you can do with less sid pairs + + + align:start position:0% +um and you can do with less sid pairs +but the reality is is that even with a + + align:start position:0% +but the reality is is that even with a + + + align:start position:0% +but the reality is is that even with a +huge number of sid pairs you you may not + + align:start position:0% +huge number of sid pairs you you may not + + + align:start position:0% +huge number of sid pairs you you may not +have a lot of power if the lambda + + align:start position:0% +have a lot of power if the lambda + + + align:start position:0% +have a lot of power if the lambda +is down here + + align:start position:0% +is down here + + + align:start position:0% +is down here +which it is for asthma probably so + + align:start position:0% +which it is for asthma probably so + + + align:start position:0% +which it is for asthma probably so +i think that this is why + + align:start position:0% +i think that this is why + + + align:start position:0% +i think that this is why +people have focused on + + align:start position:0% +people have focused on + + + align:start position:0% +people have focused on +extended pedigrees in these relative + + align:start position:0% +extended pedigrees in these relative + + + align:start position:0% +extended pedigrees in these relative +genetic isolates and that's why we're so + + align:start position:0% +genetic isolates and that's why we're so + + + align:start position:0% +genetic isolates and that's why we're so +excited about costa rica uh the finns + + align:start position:0% +excited about costa rica uh the finns + + + align:start position:0% +excited about costa rica uh the finns +are clearly excited about finland and + + align:start position:0% +are clearly excited about finland and + + + align:start position:0% +are clearly excited about finland and +decode is + + align:start position:0% +decode is + + + align:start position:0% +decode is +doing what it's doing in iceland + + align:start position:0% +doing what it's doing in iceland + + + align:start position:0% +doing what it's doing in iceland +um whether we're going to be successful + + align:start position:0% +um whether we're going to be successful + + + align:start position:0% +um whether we're going to be successful +or not i don't know but + + align:start position:0% +or not i don't know but + + + align:start position:0% +or not i don't know but +the basic approach is is that whether + + align:start position:0% +the basic approach is is that whether + + + align:start position:0% +the basic approach is is that whether +you're using an outbred population or a + + align:start position:0% +you're using an outbred population or a + + + align:start position:0% +you're using an outbred population or a +genetic isolate and whether you're using + + align:start position:0% +genetic isolate and whether you're using + + + align:start position:0% +genetic isolate and whether you're using +sib pairs or pedigrees is you've got + + align:start position:0% +sib pairs or pedigrees is you've got + + + align:start position:0% +sib pairs or pedigrees is you've got +these + + align:start position:0% +these + + + align:start position:0% +these +usually die and try nucleotide repeat uh + + align:start position:0% +usually die and try nucleotide repeat uh + + + align:start position:0% +usually die and try nucleotide repeat uh +str microsatellite markers + + align:start position:0% +str microsatellite markers + + + align:start position:0% +str microsatellite markers +um most of the genome services use about + + align:start position:0% +um most of the genome services use about + + + align:start position:0% +um most of the genome services use about +400 of these markers + + align:start position:0% +400 of these markers + + + align:start position:0% +400 of these markers +equally randomly spaced across the + + align:start position:0% +equally randomly spaced across the + + + align:start position:0% +equally randomly spaced across the +genome and what you do is you do just + + align:start position:0% +genome and what you do is you do just + + + align:start position:0% +genome and what you do is you do just +do a form of logistic regression + + align:start position:0% +do a form of logistic regression + + + align:start position:0% +do a form of logistic regression +basically where you would do a lot score + + align:start position:0% +basically where you would do a lot score + + + align:start position:0% +basically where you would do a lot score +log of the odds ratio calculation + + align:start position:0% +log of the odds ratio calculation + + + align:start position:0% +log of the odds ratio calculation +between relating phenotype in the family + + align:start position:0% +between relating phenotype in the family + + + align:start position:0% +between relating phenotype in the family +to these markers and what you do is you + + align:start position:0% +to these markers and what you do is you + + + align:start position:0% +to these markers and what you do is you +get a peak a linkage peak that is the + + align:start position:0% +get a peak a linkage peak that is the + + + align:start position:0% +get a peak a linkage peak that is the +lod score + + align:start position:0% +lod score + + + align:start position:0% +lod score +for that relationship between the + + align:start position:0% +for that relationship between the + + + align:start position:0% +for that relationship between the +markers and + + align:start position:0% +markers and + + + align:start position:0% +markers and +the uh um the phenotype and what that + + align:start position:0% +the uh um the phenotype and what that + + + align:start position:0% +the uh um the phenotype and what that +says is + + align:start position:0% +says is + + + align:start position:0% +says is +okay + + align:start position:0% +okay + + + align:start position:0% +okay +there's a gene or multiple genes in this + + align:start position:0% +there's a gene or multiple genes in this + + + align:start position:0% +there's a gene or multiple genes in this +particular region on a chromosome that's + + align:start position:0% +particular region on a chromosome that's + + + align:start position:0% +particular region on a chromosome that's +associated with a particular phenotype + + align:start position:0% +associated with a particular phenotype + + + align:start position:0% +associated with a particular phenotype +and then you have to then going down and + + align:start position:0% +and then you have to then going down and + + + align:start position:0% +and then you have to then going down and +put more markers first more str markers + + align:start position:0% +put more markers first more str markers + + + align:start position:0% +put more markers first more str markers +and then micro uh snips and and + + align:start position:0% +and then micro uh snips and and + + + align:start position:0% +and then micro uh snips and and +gradually map that region until you've + + align:start position:0% +gradually map that region until you've + + + align:start position:0% +gradually map that region until you've +actually got it down to a very very + + align:start position:0% +actually got it down to a very very + + + align:start position:0% +actually got it down to a very very +small + + align:start position:0% +small + + + align:start position:0% +small +region of a particular + + align:start position:0% +region of a particular + + + align:start position:0% +region of a particular +you know + + align:start position:0% +you know + + + align:start position:0% +you know +thousand base pairs or whatever we can + + align:start position:0% +thousand base pairs or whatever we can + + + align:start position:0% +thousand base pairs or whatever we can +say it's a gene or + + align:start position:0% +say it's a gene or + + + align:start position:0% +say it's a gene or +one or two genes in this uh a relatively + + align:start position:0% +one or two genes in this uh a relatively + + + align:start position:0% +one or two genes in this uh a relatively +large region so that's that takes a lot + + align:start position:0% +large region so that's that takes a lot + + + align:start position:0% +large region so that's that takes a lot +of genotyping and a lot of work so our + + align:start position:0% +of genotyping and a lot of work so our + + + align:start position:0% +of genotyping and a lot of work so our +experiments now over the next year we + + align:start position:0% +experiments now over the next year we + + + align:start position:0% +experiments now over the next year we +have all these linkage peaks and asthma + + align:start position:0% +have all these linkage peaks and asthma + + + align:start position:0% +have all these linkage peaks and asthma +and copd each experiment is going to be + + align:start position:0% +and copd each experiment is going to be + + + align:start position:0% +and copd each experiment is going to be +about 200 000 is going to be 1500 1600 + + align:start position:0% +about 200 000 is going to be 1500 1600 + + + align:start position:0% +about 200 000 is going to be 1500 1600 +snips in each of these regions + + align:start position:0% +snips in each of these regions + + + align:start position:0% +snips in each of these regions +and and we're going to uh fine map three + + align:start position:0% +and and we're going to uh fine map three + + + align:start position:0% +and and we're going to uh fine map three +or four regions over the course of the + + align:start position:0% +or four regions over the course of the + + + align:start position:0% +or four regions over the course of the +next year and hopefully we will be in + + align:start position:0% +next year and hopefully we will be in + + + align:start position:0% +next year and hopefully we will be in +science + + align:start position:0% +science + + + align:start position:0% +science +what's the best + + align:start position:0% + + + + align:start position:0% + +you know + + align:start position:0% +you know + + + align:start position:0% +you know +snips for 100 base pairs kind of thing + + align:start position:0% + + + + align:start position:0% + +on the order of one per uh you know one + + align:start position:0% +on the order of one per uh you know one + + + align:start position:0% +on the order of one per uh you know one +per thousand about one per thousand + + align:start position:0% +per thousand about one per thousand + + + align:start position:0% +per thousand about one per thousand +basis that's about what we're shooting + + align:start position:0% +basis that's about what we're shooting + + + align:start position:0% +basis that's about what we're shooting +for + + align:start position:0% +for + + + align:start position:0% +for +so this is just a summary of all of the + + align:start position:0% +so this is just a summary of all of the + + + align:start position:0% +so this is just a summary of all of the +genome screens that have been done in + + align:start position:0% +genome screens that have been done in + + + align:start position:0% +genome screens that have been done in +asthma just to show you that + + align:start position:0% +asthma just to show you that + + + align:start position:0% +asthma just to show you that +uh most of them have used but sid pair + + align:start position:0% +uh most of them have used but sid pair + + + align:start position:0% +uh most of them have used but sid pair +studies most of them have been + + align:start position:0% +studies most of them have been + + + align:start position:0% +studies most of them have been +relatively small but we do get a + + align:start position:0% +relatively small but we do get a + + + align:start position:0% +relatively small but we do get a +substantial amount of replication these + + align:start position:0% +substantial amount of replication these + + + align:start position:0% +substantial amount of replication these +are regions across the genome this one + + align:start position:0% +are regions across the genome this one + + + align:start position:0% +are regions across the genome this one +right here that's the gene that was just + + align:start position:0% +right here that's the gene that was just + + + align:start position:0% +right here that's the gene that was just +mapped + + align:start position:0% +mapped + + + align:start position:0% +mapped +okay + + align:start position:0% +okay + + + align:start position:0% +okay +several populations including the finns + + align:start position:0% +several populations including the finns + + + align:start position:0% +several populations including the finns +showed a peak in this region + + align:start position:0% +showed a peak in this region + + + align:start position:0% +showed a peak in this region +and um + + align:start position:0% +and um + + + align:start position:0% +and um +they got this gene and then they went to + + align:start position:0% +they got this gene and then they went to + + + align:start position:0% +they got this gene and then they went to +the the + + align:start position:0% +the the + + + align:start position:0% +the the +canadians and they said can we replicate + + align:start position:0% +canadians and they said can we replicate + + + align:start position:0% +canadians and they said can we replicate +it in your population the interesting + + align:start position:0% +it in your population the interesting + + + align:start position:0% +it in your population the interesting +thing is it was asthma in the fins but + + align:start position:0% +thing is it was asthma in the fins but + + + align:start position:0% +thing is it was asthma in the fins but +it's high ige in the canadians so + + align:start position:0% +it's high ige in the canadians so + + + align:start position:0% +it's high ige in the canadians so +it shows you that this + + align:start position:0% +it shows you that this + + + align:start position:0% +it shows you that this +problem of + + align:start position:0% +problem of + + + align:start position:0% +problem of +phenotypic heterogeneity and genetic + + align:start position:0% +phenotypic heterogeneity and genetic + + + align:start position:0% +phenotypic heterogeneity and genetic +heterogeneity is a big issue + + align:start position:0% +heterogeneity is a big issue + + + align:start position:0% +heterogeneity is a big issue +here so it isn't a perfect + + align:start position:0% +here so it isn't a perfect + + + align:start position:0% +here so it isn't a perfect +replication + + align:start position:0% +replication + + + align:start position:0% +replication +at the phenotype level between these two + + align:start position:0% +at the phenotype level between these two + + + align:start position:0% +at the phenotype level between these two +populations but they've got all this + + align:start position:0% +populations but they've got all this + + + align:start position:0% +populations but they've got all this +other stuff the expression and + + align:start position:0% +other stuff the expression and + + + align:start position:0% +other stuff the expression and +everything else that proves that they've + + align:start position:0% +everything else that proves that they've + + + align:start position:0% +everything else that proves that they've +really got the gene + + align:start position:0% +really got the gene + + + align:start position:0% +really got the gene +but the one the one we're working on + + align:start position:0% +but the one the one we're working on + + + align:start position:0% +but the one the one we're working on +is + + align:start position:0% +is + + + align:start position:0% +is +uh um actually not on here it's i didn't + + align:start position:0% +uh um actually not on here it's i didn't + + + align:start position:0% +uh um actually not on here it's i didn't +leave it off intentionally but it's it's + + align:start position:0% +leave it off intentionally but it's it's + + + align:start position:0% +leave it off intentionally but it's it's +12q + + align:start position:0% +12q + + + align:start position:0% +12q +uh and it's one of the ones that's the + + align:start position:0% +uh and it's one of the ones that's the + + + align:start position:0% +uh and it's one of the ones that's the +most replicable + + align:start position:0% +most replicable + + + align:start position:0% +most replicable +uh here it is here it's in this slide + + align:start position:0% +uh here it is here it's in this slide + + + align:start position:0% +uh here it is here it's in this slide +right here + + align:start position:0% +right here + + + align:start position:0% +right here +so this is uh this is a very good region + + align:start position:0% +so this is uh this is a very good region + + + align:start position:0% +so this is uh this is a very good region +and there's now sydney here um but it's + + align:start position:0% +and there's now sydney here um but it's + + + align:start position:0% +and there's now sydney here um but it's +also got a very low p value so that's + + align:start position:0% +also got a very low p value so that's + + + align:start position:0% +also got a very low p value so that's +one of the better ones now you know you + + align:start position:0% +one of the better ones now you know you + + + align:start position:0% +one of the better ones now you know you +can already see from this + + align:start position:0% +can already see from this + + + align:start position:0% +can already see from this +each one of these this region has five + + align:start position:0% +each one of these this region has five + + + align:start position:0% +each one of these this region has five +or six different genes in this region + + align:start position:0% +or six different genes in this region + + + align:start position:0% +or six different genes in this region +there's the cytokine cluster is here + + align:start position:0% +there's the cytokine cluster is here + + + align:start position:0% +there's the cytokine cluster is here +beta-2 adrenergic receptors here il13 is + + align:start position:0% +beta-2 adrenergic receptors here il13 is + + + align:start position:0% +beta-2 adrenergic receptors here il13 is +here cd14 is here so there's a whole + + align:start position:0% +here cd14 is here so there's a whole + + + align:start position:0% +here cd14 is here so there's a whole +bunch of small genes and here nobody + + align:start position:0% +bunch of small genes and here nobody + + + align:start position:0% +bunch of small genes and here nobody +knows whether there's a big big gene or + + align:start position:0% +knows whether there's a big big gene or + + + align:start position:0% +knows whether there's a big big gene or +not you know maybe that that linkage + + align:start position:0% +not you know maybe that that linkage + + + align:start position:0% +not you know maybe that that linkage +peak is just being + + align:start position:0% +peak is just being + + + align:start position:0% +peak is just being +given by the fact that there's a whole + + align:start position:0% +given by the fact that there's a whole + + + align:start position:0% +given by the fact that there's a whole +bunch of small genes in in in that + + align:start position:0% +bunch of small genes in in in that + + + align:start position:0% +bunch of small genes in in in that +region um + + align:start position:0% +region um + + + align:start position:0% +region um +this this one the one we're working in + + align:start position:0% +this this one the one we're working in + + + align:start position:0% +this this one the one we're working in +this is uh 30 megabases it's huge + + align:start position:0% +this is uh 30 megabases it's huge + + + align:start position:0% +this is uh 30 megabases it's huge +huge region so + + align:start position:0% +huge region so + + + align:start position:0% +huge region so +but you can see from just looking at + + align:start position:0% +but you can see from just looking at + + + align:start position:0% +but you can see from just looking at +this that one two three four five six + + align:start position:0% +this that one two three four five six + + + align:start position:0% +this that one two three four five six +seven eight nine + + align:start position:0% +seven eight nine + + + align:start position:0% +seven eight nine +and there's another i mean these are 20 + + align:start position:0% +and there's another i mean these are 20 + + + align:start position:0% +and there's another i mean these are 20 +regions each of them about 20 to 30 + + align:start position:0% +regions each of them about 20 to 30 + + + align:start position:0% +regions each of them about 20 to 30 +20 to 40 megabases + + align:start position:0% +20 to 40 megabases + + + align:start position:0% +20 to 40 megabases +they + + align:start position:0% +they + + + align:start position:0% +they +there could be five or six genes in each + + align:start position:0% +there could be five or six genes in each + + + align:start position:0% +there could be five or six genes in each +one of these regions and at least two of + + align:start position:0% +one of these regions and at least two of + + + align:start position:0% +one of these regions and at least two of +the positionally cloned genes there were + + align:start position:0% +the positionally cloned genes there were + + + align:start position:0% +the positionally cloned genes there were +two genes in the region + + align:start position:0% +two genes in the region + + + align:start position:0% +two genes in the region +and and you couldn't tell from the + + align:start position:0% +and and you couldn't tell from the + + + align:start position:0% +and and you couldn't tell from the +articles in fact this finnish article + + align:start position:0% +articles in fact this finnish article + + + align:start position:0% +articles in fact this finnish article +that's about to come out you can there's + + align:start position:0% +that's about to come out you can there's + + + align:start position:0% +that's about to come out you can there's +a second gene they identified and they + + align:start position:0% +a second gene they identified and they + + + align:start position:0% +a second gene they identified and they +don't have the molecular biology on that + + align:start position:0% +don't have the molecular biology on that + + + align:start position:0% +don't have the molecular biology on that +in the paper + + align:start position:0% +in the paper + + + align:start position:0% +in the paper +and they don't they're not sure what + + align:start position:0% +and they don't they're not sure what + + + align:start position:0% +and they don't they're not sure what +that gene is doing + + align:start position:0% +that gene is doing + + + align:start position:0% +that gene is doing +so you're actually gonna do a pineapple + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +probably + + align:start position:0% +probably + + + align:start position:0% +probably +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +so these are some of the issues in doing + + align:start position:0% +so these are some of the issues in doing + + + align:start position:0% +so these are some of the issues in doing +the type of linkage studies that i + + align:start position:0% +the type of linkage studies that i + + + align:start position:0% +the type of linkage studies that i +talked about multiple markers multiple + + align:start position:0% +talked about multiple markers multiple + + + align:start position:0% +talked about multiple markers multiple +phenotypes multiple comparisons + + align:start position:0% +phenotypes multiple comparisons + + + align:start position:0% +phenotypes multiple comparisons +phenotypes are correlated markers not + + align:start position:0% +phenotypes are correlated markers not + + + align:start position:0% +phenotypes are correlated markers not +independent you know you got to do so + + align:start position:0% +independent you know you got to do so + + + align:start position:0% +independent you know you got to do so +there's a lot of statistical issues you + + align:start position:0% +there's a lot of statistical issues you + + + align:start position:0% +there's a lot of statistical issues you +know this this work is really exciting i + + align:start position:0% +know this this work is really exciting i + + + align:start position:0% +know this this work is really exciting i +think because it combines + + align:start position:0% +think because it combines + + + align:start position:0% +think because it combines +genetics clinical medicine molecular + + align:start position:0% +genetics clinical medicine molecular + + + align:start position:0% +genetics clinical medicine molecular +genetics statistics + + align:start position:0% +genetics statistics + + + align:start position:0% +genetics statistics +evolutionary it's all this stuff is all + + align:start position:0% +evolutionary it's all this stuff is all + + + align:start position:0% +evolutionary it's all this stuff is all +mixed together so a lot of important + + align:start position:0% +mixed together so a lot of important + + + align:start position:0% +mixed together so a lot of important +statistical issues in doing these genome + + align:start position:0% +statistical issues in doing these genome + + + align:start position:0% +statistical issues in doing these genome +screens + + align:start position:0% +screens + + + align:start position:0% +screens +so then you got a genotype to people + + align:start position:0% +so then you got a genotype to people + + + align:start position:0% +so then you got a genotype to people +you've already said that you know snips + + align:start position:0% +you've already said that you know snips + + + align:start position:0% +you've already said that you know snips +are the primary + + align:start position:0% +are the primary + + + align:start position:0% +are the primary +genetic variation in the human genome + + align:start position:0% +genetic variation in the human genome + + + align:start position:0% +genetic variation in the human genome +but we found + + align:start position:0% +but we found + + + align:start position:0% +but we found +indels we found + + align:start position:0% +indels we found + + + align:start position:0% +indels we found +uh + + align:start position:0% +uh + + + align:start position:0% +uh +repeats we found + + align:start position:0% + + + + align:start position:0% + +snips and indels together i mean there's + + align:start position:0% +snips and indels together i mean there's + + + align:start position:0% +snips and indels together i mean there's +all kinds of stuff uh in general snips + + align:start position:0% +all kinds of stuff uh in general snips + + + align:start position:0% +all kinds of stuff uh in general snips +occur about + + align:start position:0% +occur about + + + align:start position:0% +occur about +you know between one and a thousand and + + align:start position:0% +you know between one and a thousand and + + + align:start position:0% +you know between one and a thousand and +one and two thousand base pairs they're + + align:start position:0% +one and two thousand base pairs they're + + + align:start position:0% +one and two thousand base pairs they're +approximately three + + align:start position:0% +approximately three + + + align:start position:0% +approximately three +um maybe three to five million in the + + align:start position:0% +um maybe three to five million in the + + + align:start position:0% +um maybe three to five million in the +human genome and you know it's using + + align:start position:0% +human genome and you know it's using + + + align:start position:0% +human genome and you know it's using +these + + align:start position:0% +these + + + align:start position:0% +these +as the primary source of genetic + + align:start position:0% +as the primary source of genetic + + + align:start position:0% +as the primary source of genetic +variation that we're actually sort of + + align:start position:0% +variation that we're actually sort of + + + align:start position:0% +variation that we're actually sort of +going at trying to map these genes + + align:start position:0% +going at trying to map these genes + + + align:start position:0% +going at trying to map these genes +there's a whole host of questions about + + align:start position:0% +there's a whole host of questions about + + + align:start position:0% +there's a whole host of questions about +how do you pick snips you know we wrote + + align:start position:0% +how do you pick snips you know we wrote + + + align:start position:0% +how do you pick snips you know we wrote +a paper together zach and i with some of + + align:start position:0% +a paper together zach and i with some of + + + align:start position:0% +a paper together zach and i with some of +our colleagues about + + align:start position:0% +our colleagues about + + + align:start position:0% +our colleagues about +haplotype tagging snips + + align:start position:0% +haplotype tagging snips + + + align:start position:0% +haplotype tagging snips +there's other approaches to using + + align:start position:0% +there's other approaches to using + + + align:start position:0% +there's other approaches to using +linkage disequilibrium to define the + + align:start position:0% +linkage disequilibrium to define the + + + align:start position:0% +linkage disequilibrium to define the +snips that you want to genotype so lots + + align:start position:0% +snips that you want to genotype so lots + + + align:start position:0% +snips that you want to genotype so lots +of issues there + + align:start position:0% +of issues there + + + align:start position:0% +of issues there +where sort of bioinformatics is + + align:start position:0% +where sort of bioinformatics is + + + align:start position:0% +where sort of bioinformatics is +interfacing with human genetics + + align:start position:0% +interfacing with human genetics + + + align:start position:0% +interfacing with human genetics +um + + align:start position:0% +um + + + align:start position:0% +um +no one really knows + + align:start position:0% +no one really knows + + + align:start position:0% +no one really knows +you know this is probably not 30 million + + align:start position:0% +you know this is probably not 30 million + + + align:start position:0% +you know this is probably not 30 million +this + + align:start position:0% +this + + + align:start position:0% +this +is probably three + + align:start position:0% +is probably three + + + align:start position:0% +is probably three +but + + align:start position:0% +but + + + align:start position:0% +but +you know no one really knows how many of + + align:start position:0% +you know no one really knows how many of + + + align:start position:0% +you know no one really knows how many of +these + + align:start position:0% +these + + + align:start position:0% +these +snips are actually coding + + align:start position:0% +snips are actually coding + + + align:start position:0% +snips are actually coding +and + + align:start position:0% +and + + + align:start position:0% +and +i think everybody does know + + align:start position:0% +i think everybody does know + + + align:start position:0% +i think everybody does know +that there are more than coding snips + + align:start position:0% +that there are more than coding snips + + + align:start position:0% +that there are more than coding snips +that are important + + align:start position:0% +that are important + + + align:start position:0% +that are important +promoter snips are important coding + + align:start position:0% +promoter snips are important coding + + + align:start position:0% +promoter snips are important coding +snips are important snips in the three + + align:start position:0% +snips are important snips in the three + + + align:start position:0% +snips are important snips in the three +prime ut are important because they're + + align:start position:0% +prime ut are important because they're + + + align:start position:0% +prime ut are important because they're +going to + + align:start position:0% +going to + + + align:start position:0% +going to +change + + align:start position:0% +change + + + align:start position:0% +change +transcription factor binding and + + align:start position:0% +transcription factor binding and + + + align:start position:0% +transcription factor binding and +potentially change message level whole + + align:start position:0% +potentially change message level whole + + + align:start position:0% +potentially change message level whole +host of different and and any one snip + + align:start position:0% +host of different and and any one snip + + + align:start position:0% +host of different and and any one snip +is probably in and of itself isn't going + + align:start position:0% +is probably in and of itself isn't going + + + align:start position:0% +is probably in and of itself isn't going +to change function + + align:start position:0% +to change function + + + align:start position:0% +to change function +in a gene + + align:start position:0% +in a gene + + + align:start position:0% +in a gene +all that dramatically so people are + + align:start position:0% +all that dramatically so people are + + + align:start position:0% +all that dramatically so people are +going towards this idea of you know + + align:start position:0% +going towards this idea of you know + + + align:start position:0% +going towards this idea of you know +analyzing data at the molecular level by + + align:start position:0% +analyzing data at the molecular level by + + + align:start position:0% +analyzing data at the molecular level by +looking at + + align:start position:0% +looking at + + + align:start position:0% +looking at +relevant functional haplotypes you know + + align:start position:0% +relevant functional haplotypes you know + + + align:start position:0% +relevant functional haplotypes you know +if you've got a couple snips in the + + align:start position:0% +if you've got a couple snips in the + + + align:start position:0% +if you've got a couple snips in the +promoter + + align:start position:0% +promoter + + + align:start position:0% +promoter +uh um + + align:start position:0% +uh um + + + align:start position:0% +uh um +you know another that's a non-synonymous + + align:start position:0% +you know another that's a non-synonymous + + + align:start position:0% +you know another that's a non-synonymous +c-snip and an exon another that's uh um + + align:start position:0% +c-snip and an exon another that's uh um + + + align:start position:0% +c-snip and an exon another that's uh um +at + + align:start position:0% +at + + + align:start position:0% +at +a splice site another that's in the + + align:start position:0% +a splice site another that's in the + + + align:start position:0% +a splice site another that's in the +three prime utr that's determining + + align:start position:0% +three prime utr that's determining + + + align:start position:0% +three prime utr that's determining +message level of stability we combine + + align:start position:0% +message level of stability we combine + + + align:start position:0% +message level of stability we combine +all of those snips to try to get an + + align:start position:0% +all of those snips to try to get an + + + align:start position:0% +all of those snips to try to get an +effect across that whole gene + + align:start position:0% +effect across that whole gene + + + align:start position:0% +effect across that whole gene +uh in terms of looking at that gene and + + align:start position:0% +uh in terms of looking at that gene and + + + align:start position:0% +uh in terms of looking at that gene and +its impact on on phenotype + + align:start position:0% + + + + align:start position:0% + +so this is just a little bit about data + + align:start position:0% +so this is just a little bit about data + + + align:start position:0% +so this is just a little bit about data +analysis you know you can either look at + + align:start position:0% +analysis you know you can either look at + + + align:start position:0% +analysis you know you can either look at +continuous quantitative + + align:start position:0% + + + + align:start position:0% + +quantitative traits or qualitative + + align:start position:0% +quantitative traits or qualitative + + + align:start position:0% +quantitative traits or qualitative +traits they're parametric and + + align:start position:0% +traits they're parametric and + + + align:start position:0% +traits they're parametric and +non-parametric approaches to this + + align:start position:0% +non-parametric approaches to this + + + align:start position:0% +non-parametric approaches to this +um + + align:start position:0% +um + + + align:start position:0% +um +then you you know you use all the stuff + + align:start position:0% +then you you know you use all the stuff + + + align:start position:0% +then you you know you use all the stuff +you actually find the gene + + align:start position:0% +you actually find the gene + + + align:start position:0% +you actually find the gene +um + + align:start position:0% +um + + + align:start position:0% +um +i think that people are not doing the + + align:start position:0% +i think that people are not doing the + + + align:start position:0% +i think that people are not doing the +initial work was done with yak and back + + align:start position:0% +initial work was done with yak and back + + + align:start position:0% +initial work was done with yak and back +clones but now we're past + + align:start position:0% +clones but now we're past + + + align:start position:0% +clones but now we're past +the idea of doing that because there's + + align:start position:0% +the idea of doing that because there's + + + align:start position:0% +the idea of doing that because there's +enough markers with a hat map project + + align:start position:0% +enough markers with a hat map project + + + align:start position:0% +enough markers with a hat map project +across the genome that we can go into + + align:start position:0% +across the genome that we can go into + + + align:start position:0% +across the genome that we can go into +almost any region now in the genome and + + align:start position:0% +almost any region now in the genome and + + + align:start position:0% +almost any region now in the genome and +we can come up with + + align:start position:0% +we can come up with + + + align:start position:0% +we can come up with +validated snips across that region so + + align:start position:0% +validated snips across that region so + + + align:start position:0% +validated snips across that region so +that we can actually pick snips and + + align:start position:0% +that we can actually pick snips and + + + align:start position:0% +that we can actually pick snips and +genotype them and go directly and this + + align:start position:0% +genotype them and go directly and this + + + align:start position:0% +genotype them and go directly and this +is what's accelerating the pace of uh + + align:start position:0% +is what's accelerating the pace of uh + + + align:start position:0% +is what's accelerating the pace of uh +positional cloning + + align:start position:0% +positional cloning + + + align:start position:0% +positional cloning +at the moment + + align:start position:0% + + + + align:start position:0% + +so these are some of the things that i + + align:start position:0% +so these are some of the things that i + + + align:start position:0% +so these are some of the things that i +haven't really talked about this this is + + align:start position:0% +haven't really talked about this this is + + + align:start position:0% +haven't really talked about this this is +introductory this lecture but you know + + align:start position:0% +introductory this lecture but you know + + + align:start position:0% +introductory this lecture but you know +you really get into this you know how do + + align:start position:0% +you really get into this you know how do + + + align:start position:0% +you really get into this you know how do +you do haplotype analysis + + align:start position:0% +you do haplotype analysis + + + align:start position:0% +you do haplotype analysis +uh ancestral haplotype analysis or + + align:start position:0% +uh ancestral haplotype analysis or + + + align:start position:0% +uh ancestral haplotype analysis or +linkage disequilibrium mapping + + align:start position:0% +linkage disequilibrium mapping + + + align:start position:0% +linkage disequilibrium mapping +molecular methods or tissue expression + + align:start position:0% +molecular methods or tissue expression + + + align:start position:0% +molecular methods or tissue expression +all of these things can potentially be + + align:start position:0% +all of these things can potentially be + + + align:start position:0% +all of these things can potentially be +helpful in the fine mapping process we + + align:start position:0% +helpful in the fine mapping process we + + + align:start position:0% +helpful in the fine mapping process we +you know we've been very interested + + align:start position:0% +you know we've been very interested + + + align:start position:0% +you know we've been very interested +and have a project with zac where we + + align:start position:0% +and have a project with zac where we + + + align:start position:0% +and have a project with zac where we +wanted to use + + align:start position:0% +wanted to use + + + align:start position:0% +wanted to use +mouse expression and + + align:start position:0% +mouse expression and + + + align:start position:0% +mouse expression and +mouse qtl analysis to help us with human + + align:start position:0% +mouse qtl analysis to help us with human + + + align:start position:0% +mouse qtl analysis to help us with human +uh oppositional cloning we're not sure + + align:start position:0% +uh oppositional cloning we're not sure + + + align:start position:0% +uh oppositional cloning we're not sure +if our project's going to be funded so + + align:start position:0% +if our project's going to be funded so + + + align:start position:0% +if our project's going to be funded so +we don't know if we're actually going to + + align:start position:0% +we don't know if we're actually going to + + + align:start position:0% +we don't know if we're actually going to +get a chance to do that + + align:start position:0% +get a chance to do that + + + align:start position:0% +get a chance to do that +at the end of the day you want to be + + align:start position:0% +at the end of the day you want to be + + + align:start position:0% +at the end of the day you want to be +able to look at the impact of + + align:start position:0% +able to look at the impact of + + + align:start position:0% +able to look at the impact of +polymorphic variation in the gene that + + align:start position:0% +polymorphic variation in the gene that + + + align:start position:0% +polymorphic variation in the gene that +you found and see whether that + + align:start position:0% +you found and see whether that + + + align:start position:0% +you found and see whether that +polymorphic how much of + + align:start position:0% +polymorphic how much of + + + align:start position:0% +polymorphic how much of +the phenotypic variance is explained by + + align:start position:0% +the phenotypic variance is explained by + + + align:start position:0% +the phenotypic variance is explained by +that + + align:start position:0% +that + + + align:start position:0% +that +uh of polymorphism and that gets back to + + align:start position:0% +uh of polymorphism and that gets back to + + + align:start position:0% +uh of polymorphism and that gets back to +this question of + + align:start position:0% +this question of + + + align:start position:0% +this question of +well + + align:start position:0% +well + + + align:start position:0% +well +you found a gene by positional cloning + + align:start position:0% +you found a gene by positional cloning + + + align:start position:0% +you found a gene by positional cloning +how do you know it's really a + + align:start position:0% +how do you know it's really a + + + align:start position:0% +how do you know it's really a +significant gene well does it replicate + + align:start position:0% +significant gene well does it replicate + + + align:start position:0% +significant gene well does it replicate +across different populations in + + align:start position:0% +across different populations in + + + align:start position:0% +across different populations in +different conditions is it important in + + align:start position:0% +different conditions is it important in + + + align:start position:0% +different conditions is it important in +different kinds of asthma uh does it + + align:start position:0% +different kinds of asthma uh does it + + + align:start position:0% +different kinds of asthma uh does it +seem to be explaining a significant + + align:start position:0% +seem to be explaining a significant + + + align:start position:0% +seem to be explaining a significant +amount of the variation so this is one + + align:start position:0% +amount of the variation so this is one + + + align:start position:0% +amount of the variation so this is one +example it's a poor example because it's + + align:start position:0% +example it's a poor example because it's + + + align:start position:0% +example it's a poor example because it's +not a it's not a really good one this is + + align:start position:0% +not a it's not a really good one this is + + + align:start position:0% +not a it's not a really good one this is +a gene + + align:start position:0% +a gene + + + align:start position:0% +a gene +cd14 that we genotyped in the + + align:start position:0% +cd14 that we genotyped in the + + + align:start position:0% +cd14 that we genotyped in the +programming genomic applications this + + align:start position:0% +programming genomic applications this + + + align:start position:0% +programming genomic applications this +gene is the + + align:start position:0% +gene is the + + + align:start position:0% +gene is the +gene that + + align:start position:0% +gene that + + + align:start position:0% +gene that +binds + + align:start position:0% +binds + + + align:start position:0% +binds +lps or lipopolysaccharide + + align:start position:0% +lps or lipopolysaccharide + + + align:start position:0% +lps or lipopolysaccharide +to the membrane of the monocyte and then + + align:start position:0% +to the membrane of the monocyte and then + + + align:start position:0% +to the membrane of the monocyte and then +transduces that signal + + align:start position:0% +transduces that signal + + + align:start position:0% +transduces that signal +to the t cell to produce a th1 cytokine + + align:start position:0% +to the t cell to produce a th1 cytokine + + + align:start position:0% +to the t cell to produce a th1 cytokine +so we found a polymorphism in this gene + + align:start position:0% +so we found a polymorphism in this gene + + + align:start position:0% +so we found a polymorphism in this gene +as part of the program in genomic + + align:start position:0% +as part of the program in genomic + + + align:start position:0% +as part of the program in genomic +applications + + align:start position:0% +applications + + + align:start position:0% +applications +it's a c to t polymorphism so here's the + + align:start position:0% +it's a c to t polymorphism so here's the + + + align:start position:0% +it's a c to t polymorphism so here's the +uh + + align:start position:0% + + + + align:start position:0% + +t variant here's the uh heterozygote and + + align:start position:0% +t variant here's the uh heterozygote and + + + align:start position:0% +t variant here's the uh heterozygote and +here's the c + + align:start position:0% +here's the c + + + align:start position:0% +here's the c +and you can see that + + align:start position:0% +and you can see that + + + align:start position:0% +and you can see that +if you look at a dominant model where + + align:start position:0% +if you look at a dominant model where + + + align:start position:0% +if you look at a dominant model where +the c's are together that + + align:start position:0% +the c's are together that + + + align:start position:0% +the c's are together that +anybody that has a c + + align:start position:0% + + + + align:start position:0% + +genotype + + align:start position:0% +genotype + + + align:start position:0% +genotype +actually is likely to have more positive + + align:start position:0% +actually is likely to have more positive + + + align:start position:0% +actually is likely to have more positive +skin tests than those who are tt and + + align:start position:0% +skin tests than those who are tt and + + + align:start position:0% +skin tests than those who are tt and +that + + align:start position:0% +that + + + align:start position:0% +that +genetic variation is associated with + + align:start position:0% +genetic variation is associated with + + + align:start position:0% +genetic variation is associated with +variation in soluble + + align:start position:0% +variation in soluble + + + align:start position:0% +variation in soluble +uh uh cd14 levels in peripheral blood so + + align:start position:0% +uh uh cd14 levels in peripheral blood so + + + align:start position:0% +uh uh cd14 levels in peripheral blood so +there's a relationship between genotype + + align:start position:0% +there's a relationship between genotype + + + align:start position:0% +there's a relationship between genotype +and + + align:start position:0% +and + + + align:start position:0% +and +uh + + align:start position:0% +uh + + + align:start position:0% +uh +um + + align:start position:0% + + + + align:start position:0% + +intermediate phenotype and a + + align:start position:0% +intermediate phenotype and a + + + align:start position:0% +intermediate phenotype and a +relationship to the the the uh to + + align:start position:0% +relationship to the the the uh to + + + align:start position:0% +relationship to the the the uh to +allergy ultimately + + align:start position:0% +allergy ultimately + + + align:start position:0% +allergy ultimately +uh i'm sorry is that supposed to show + + align:start position:0% +uh i'm sorry is that supposed to show + + + align:start position:0% +uh i'm sorry is that supposed to show +the difference between the two + + align:start position:0% +the difference between the two + + + align:start position:0% +the difference between the two +it's small but it was significant okay + + align:start position:0% +it's small but it was significant okay + + + align:start position:0% +it's small but it was significant okay +well i think the point here is that this + + align:start position:0% +well i think the point here is that this + + + align:start position:0% +well i think the point here is that this +is one snip + + align:start position:0% +is one snip + + + align:start position:0% +is one snip +you know this gets back to the point + + align:start position:0% +you know this gets back to the point + + + align:start position:0% +you know this gets back to the point +that you know it's not even a haplotype + + align:start position:0% +that you know it's not even a haplotype + + + align:start position:0% +that you know it's not even a haplotype +in this gene uh and and still there is + + align:start position:0% +in this gene uh and and still there is + + + align:start position:0% +in this gene uh and and still there is +uh and you know these are modest numbers + + align:start position:0% +uh and you know these are modest numbers + + + align:start position:0% +uh and you know these are modest numbers +they're not huge but they're but there + + align:start position:0% +they're not huge but they're but there + + + align:start position:0% +they're not huge but they're but there +was clearly a difference um + + align:start position:0% +was clearly a difference um + + + align:start position:0% +was clearly a difference um +probably the sort of level of difference + + align:start position:0% +probably the sort of level of difference + + + align:start position:0% +probably the sort of level of difference +you'd expect if it was just a single + + align:start position:0% +you'd expect if it was just a single + + + align:start position:0% +you'd expect if it was just a single +sniff i mean + + align:start position:0% +sniff i mean + + + align:start position:0% +sniff i mean +it's none of these effects are going to + + align:start position:0% +it's none of these effects are going to + + + align:start position:0% +it's none of these effects are going to +be very large at the level of an + + align:start position:0% +be very large at the level of an + + + align:start position:0% +be very large at the level of an +individual variant at the level of a + + align:start position:0% +individual variant at the level of a + + + align:start position:0% +individual variant at the level of a +gene with a haplotype + + align:start position:0% +gene with a haplotype + + + align:start position:0% +gene with a haplotype +with a really significant gene maybe so + + align:start position:0% +with a really significant gene maybe so + + + align:start position:0% +with a really significant gene maybe so +but but not certainly not one snip + + align:start position:0% +but but not certainly not one snip + + + align:start position:0% +but but not certainly not one snip +so these are some of the skills that if + + align:start position:0% +so these are some of the skills that if + + + align:start position:0% +so these are some of the skills that if +you guys want to do this work if you + + align:start position:0% +you guys want to do this work if you + + + align:start position:0% +you guys want to do this work if you +were going to come to my laboratory + + align:start position:0% +were going to come to my laboratory + + + align:start position:0% +were going to come to my laboratory +i would want you to + + align:start position:0% +i would want you to + + + align:start position:0% +i would want you to +know something about you know you you'd + + align:start position:0% +know something about you know you you'd + + + align:start position:0% +know something about you know you you'd +want to be you want to know something + + align:start position:0% +want to be you want to know something + + + align:start position:0% +want to be you want to know something +about this and how to genotype then + + align:start position:0% +about this and how to genotype then + + + align:start position:0% +about this and how to genotype then +afterwards through the disease + + align:start position:0% +afterwards through the disease + + + align:start position:0% +afterwards through the disease +study design statistical methodology + + align:start position:0% +study design statistical methodology + + + align:start position:0% +study design statistical methodology +phenotyping environmental exposures and + + align:start position:0% +phenotyping environmental exposures and + + + align:start position:0% +phenotyping environmental exposures and +i probably ought to add to this list + + align:start position:0% +i probably ought to add to this list + + + align:start position:0% +i probably ought to add to this list +bioinformatics + + align:start position:0% +bioinformatics + + + align:start position:0% +bioinformatics +because without good bioinformatics + + align:start position:0% +because without good bioinformatics + + + align:start position:0% +because without good bioinformatics +skills you're going to be lost + + align:start position:0% +skills you're going to be lost + + + align:start position:0% +skills you're going to be lost +uh and you know it's hard to know + + align:start position:0% +uh and you know it's hard to know + + + align:start position:0% +uh and you know it's hard to know +exactly + + align:start position:0% +exactly + + + align:start position:0% +exactly +where on the spectrum you know people + + align:start position:0% +where on the spectrum you know people + + + align:start position:0% +where on the spectrum you know people +wanna + + align:start position:0% +wanna + + + align:start position:0% +wanna +sort of you could + + align:start position:0% +sort of you could + + + align:start position:0% +sort of you could +do this and never have anything to do + + align:start position:0% +do this and never have anything to do + + + align:start position:0% +do this and never have anything to do +with the phenotyping and just focus on + + align:start position:0% +with the phenotyping and just focus on + + + align:start position:0% +with the phenotyping and just focus on +the functional variation + + align:start position:0% +the functional variation + + + align:start position:0% +the functional variation +uh from genes that these guys are + + align:start position:0% +uh from genes that these guys are + + + align:start position:0% +uh from genes that these guys are +are actually finding or you might sort + + align:start position:0% +are actually finding or you might sort + + + align:start position:0% +are actually finding or you might sort +of situate yourself somewhere in the + + align:start position:0% +of situate yourself somewhere in the + + + align:start position:0% +of situate yourself somewhere in the +middle + + align:start position:0% +middle + + + align:start position:0% +middle +um you know i've got people in my lab + + align:start position:0% +um you know i've got people in my lab + + + align:start position:0% +um you know i've got people in my lab +that are doing just this + + align:start position:0% +that are doing just this + + + align:start position:0% +that are doing just this +and + + align:start position:0% +and + + + align:start position:0% +and +very few people that are doing just this + + align:start position:0% +very few people that are doing just this + + + align:start position:0% +very few people that are doing just this +but i have some that are sitting in the + + align:start position:0% +but i have some that are sitting in the + + + align:start position:0% +but i have some that are sitting in the +middle + + align:start position:0% +middle + + + align:start position:0% +middle +so where are this going in the future i + + align:start position:0% +so where are this going in the future i + + + align:start position:0% +so where are this going in the future i +mean i think that + + align:start position:0% +mean i think that + + + align:start position:0% +mean i think that +uh um what's driving the field is + + align:start position:0% +uh um what's driving the field is + + + align:start position:0% +uh um what's driving the field is +high throughput sequencing and high + + align:start position:0% +high throughput sequencing and high + + + align:start position:0% +high throughput sequencing and high +throughput genotyping combined with + + align:start position:0% +throughput genotyping combined with + + + align:start position:0% +throughput genotyping combined with +bioinformatics in the presence of having + + align:start position:0% +bioinformatics in the presence of having + + + align:start position:0% +bioinformatics in the presence of having +lots of populations to do this kind of + + align:start position:0% +lots of populations to do this kind of + + + align:start position:0% +lots of populations to do this kind of +work you know that's what's really + + align:start position:0% +work you know that's what's really + + + align:start position:0% +work you know that's what's really +necessary is you got to have well + + align:start position:0% +necessary is you got to have well + + + align:start position:0% +necessary is you got to have well +phenotype populations in my lab these + + align:start position:0% +phenotype populations in my lab these + + + align:start position:0% +phenotype populations in my lab these +are all the different populations that + + align:start position:0% +are all the different populations that + + + align:start position:0% +are all the different populations that +we have for asthma we've got these + + align:start position:0% +we have for asthma we've got these + + + align:start position:0% +we have for asthma we've got these +extended pedigrees we've got affected + + align:start position:0% +extended pedigrees we've got affected + + + align:start position:0% +extended pedigrees we've got affected +sid pairs we've got trios and we've got + + align:start position:0% +sid pairs we've got trios and we've got + + + align:start position:0% +sid pairs we've got trios and we've got +individual cases and controls + + align:start position:0% +individual cases and controls + + + align:start position:0% +individual cases and controls +so that we can test the genes in + + align:start position:0% +so that we can test the genes in + + + align:start position:0% +so that we can test the genes in +multiple different populations and and + + align:start position:0% +multiple different populations and and + + + align:start position:0% +multiple different populations and and +under different + + align:start position:0% +under different + + + align:start position:0% +under different +conditions + + align:start position:0% +conditions + + + align:start position:0% +conditions +so why don't i stop there and i'd be + + align:start position:0% +so why don't i stop there and i'd be + + + align:start position:0% +so why don't i stop there and i'd be +glad to answer any questions that people + + align:start position:0% +glad to answer any questions that people + + + align:start position:0% +glad to answer any questions that people +have about any of the things that i said + + align:start position:0% + + + + align:start position:0% + +structure of proteins + + align:start position:0% +structure of proteins + + + align:start position:0% +structure of proteins +yeah well i mean i think that that means + + align:start position:0% +yeah well i mean i think that that means + + + align:start position:0% +yeah well i mean i think that that means +this is that + + align:start position:0% +this is that + + + align:start position:0% +this is that +you know actually getting into + + align:start position:0% +you know actually getting into + + + align:start position:0% +you know actually getting into +you know once you + + align:start position:0% +you know once you + + + align:start position:0% +you know once you +once you've got a relationship with a + + align:start position:0% +once you've got a relationship with a + + + align:start position:0% +once you've got a relationship with a +gene + + align:start position:0% + + + + align:start position:0% + +what you have to do is + + align:start position:0% +what you have to do is + + + align:start position:0% +what you have to do is +really + + align:start position:0% +really + + + align:start position:0% +really +get down and figure out + + align:start position:0% + + + + align:start position:0% + +what are the variants in that gene and + + align:start position:0% +what are the variants in that gene and + + + align:start position:0% +what are the variants in that gene and +what are they doing and and that that + + align:start position:0% +what are they doing and and that that + + + align:start position:0% +what are they doing and and that that +can proceed human genetics can + + align:start position:0% +can proceed human genetics can + + + align:start position:0% +can proceed human genetics can +contribute to that at the level of + + align:start position:0% +contribute to that at the level of + + + align:start position:0% +contribute to that at the level of +genetic association so for example we um + + align:start position:0% +genetic association so for example we um + + + align:start position:0% +genetic association so for example we um +laurie glimscher who's an immunologist + + align:start position:0% +laurie glimscher who's an immunologist + + + align:start position:0% +laurie glimscher who's an immunologist +at the school of public health + + align:start position:0% +at the school of public health + + + align:start position:0% +at the school of public health +identified a gene + + align:start position:0% +identified a gene + + + align:start position:0% +identified a gene +that controls + + align:start position:0% +that controls + + + align:start position:0% +that controls +uh t-cell differentiation + + align:start position:0% +uh t-cell differentiation + + + align:start position:0% +uh t-cell differentiation +uh + + align:start position:0% +uh + + + align:start position:0% +uh +it's tbx-21 or t-bet is the name of the + + align:start position:0% +it's tbx-21 or t-bet is the name of the + + + align:start position:0% +it's tbx-21 or t-bet is the name of the +gene and she created a knockout mouse + + align:start position:0% +gene and she created a knockout mouse + + + align:start position:0% +gene and she created a knockout mouse +and + + align:start position:0% +and + + + align:start position:0% +and +uh when you knock this gene out in the + + align:start position:0% +uh when you knock this gene out in the + + + align:start position:0% +uh when you knock this gene out in the +mouse you get tremendous airways + + align:start position:0% +mouse you get tremendous airways + + + align:start position:0% +mouse you get tremendous airways +responsiveness and allergic + + align:start position:0% +responsiveness and allergic + + + align:start position:0% +responsiveness and allergic +inflammation it looks like an asthma + + align:start position:0% +inflammation it looks like an asthma + + + align:start position:0% +inflammation it looks like an asthma +gene in the mouse + + align:start position:0% +gene in the mouse + + + align:start position:0% +gene in the mouse +and and + + align:start position:0% +and and + + + align:start position:0% +and and +so we sequenced that gene + + align:start position:0% +so we sequenced that gene + + + align:start position:0% +so we sequenced that gene +and then we started to + + align:start position:0% +and then we started to + + + align:start position:0% +and then we started to +look at we found a variant in the gene + + align:start position:0% +look at we found a variant in the gene + + + align:start position:0% +look at we found a variant in the gene +that's + + align:start position:0% +that's + + + align:start position:0% +that's +in the coding region it's it's a + + align:start position:0% +in the coding region it's it's a + + + align:start position:0% +in the coding region it's it's a +non-synonymous c-snip in the coding + + align:start position:0% +non-synonymous c-snip in the coding + + + align:start position:0% +non-synonymous c-snip in the coding +region it's very rare it's only occurs + + align:start position:0% +region it's very rare it's only occurs + + + align:start position:0% +region it's very rare it's only occurs +in about three percent of people but it + + align:start position:0% +in about three percent of people but it + + + align:start position:0% +in about three percent of people but it +turns out that that coding region + + align:start position:0% +turns out that that coding region + + + align:start position:0% +turns out that that coding region +variant + + align:start position:0% +variant + + + align:start position:0% +variant +is uh um + + align:start position:0% +is uh um + + + align:start position:0% +is uh um +determines + + align:start position:0% +determines + + + align:start position:0% +determines +which patients who get inhaled steroids + + align:start position:0% +which patients who get inhaled steroids + + + align:start position:0% +which patients who get inhaled steroids +get better + + align:start position:0% +get better + + + align:start position:0% +get better +the people that have that variant + + align:start position:0% +the people that have that variant + + + align:start position:0% +the people that have that variant +and get inhaled steroids have their + + align:start position:0% +and get inhaled steroids have their + + + align:start position:0% +and get inhaled steroids have their +airways responsiveness completely + + align:start position:0% +airways responsiveness completely + + + align:start position:0% +airways responsiveness completely +returned to normal + + align:start position:0% + + + + align:start position:0% + +we're about to submit it to the lancet + + align:start position:0% +we're about to submit it to the lancet + + + align:start position:0% +we're about to submit it to the lancet +we're actually working with laurie to + + align:start position:0% +we're actually working with laurie to + + + align:start position:0% +we're actually working with laurie to +it's pretty exciting + + align:start position:0% +it's pretty exciting + + + align:start position:0% +it's pretty exciting +it's it's it's exciting because it's + + align:start position:0% +it's it's it's exciting because it's + + + align:start position:0% +it's it's it's exciting because it's +example of how you can actually you + + align:start position:0% +example of how you can actually you + + + align:start position:0% +example of how you can actually you +don't have to even go to the animal + + align:start position:0% +don't have to even go to the animal + + + align:start position:0% +don't have to even go to the animal +model and so she then + + align:start position:0% +model and so she then + + + align:start position:0% +model and so she then +crea + + align:start position:0% +crea + + + align:start position:0% +crea +has created you know her mouse model she + + align:start position:0% +has created you know her mouse model she + + + align:start position:0% +has created you know her mouse model she +started to do some experiments with + + align:start position:0% +started to do some experiments with + + + align:start position:0% +started to do some experiments with +steroids and steroids are probably + + align:start position:0% +steroids and steroids are probably + + + align:start position:0% +steroids and steroids are probably +important in controlling t-bed + + align:start position:0% +important in controlling t-bed + + + align:start position:0% +important in controlling t-bed +expression + + align:start position:0% +expression + + + align:start position:0% +expression +and she didn't know that + + align:start position:0% +and she didn't know that + + + align:start position:0% +and she didn't know that +so that's an example of + + align:start position:0% +so that's an example of + + + align:start position:0% +so that's an example of +structure function relationships where + + align:start position:0% +structure function relationships where + + + align:start position:0% +structure function relationships where +you're trying to figure out + + align:start position:0% +you're trying to figure out + + + align:start position:0% +you're trying to figure out +what a gene actually does and it is + + align:start position:0% +what a gene actually does and it is + + + align:start position:0% +what a gene actually does and it is +important to recognize + + align:start position:0% +important to recognize + + + align:start position:0% +important to recognize +there are some genes + + align:start position:0% +there are some genes + + + align:start position:0% +there are some genes +that have been around for a while + + align:start position:0% +that have been around for a while + + + align:start position:0% +that have been around for a while +and and + + align:start position:0% +and and + + + align:start position:0% +and and +people still don't know we know there's + + align:start position:0% +people still don't know we know there's + + + align:start position:0% +people still don't know we know there's +a relationship to a disease phenotype + + align:start position:0% +a relationship to a disease phenotype + + + align:start position:0% +a relationship to a disease phenotype +but we don't know how the hell they work + + align:start position:0% +but we don't know how the hell they work + + + align:start position:0% +but we don't know how the hell they work +so figuring out that structure function + + align:start position:0% +so figuring out that structure function + + + align:start position:0% +so figuring out that structure function +stuff can take a long time potentially + + align:start position:0% +stuff can take a long time potentially + + + align:start position:0% +stuff can take a long time potentially +and doing the genetic association and + + align:start position:0% +and doing the genetic association and + + + align:start position:0% +and doing the genetic association and +the fine mapping may actually now + + align:start position:0% +the fine mapping may actually now + + + align:start position:0% +the fine mapping may actually now +proceed at a faster pace and and not + + align:start position:0% +proceed at a faster pace and and not + + + align:start position:0% +proceed at a faster pace and and not +take as much time + + align:start position:0% +take as much time + + + align:start position:0% +take as much time +but i think it's um + + align:start position:0% + + + + align:start position:0% + +you can actually do + + align:start position:0% +you can actually do + + + align:start position:0% +you can actually do +a lot of structure function stuff + + align:start position:0% +a lot of structure function stuff + + + align:start position:0% +a lot of structure function stuff +usually what we do is when we get an + + align:start position:0% +usually what we do is when we get an + + + align:start position:0% +usually what we do is when we get an +association we will type every damn + + align:start position:0% +association we will type every damn + + + align:start position:0% +association we will type every damn +we'll sequence that gene we'll type + + align:start position:0% +we'll sequence that gene we'll type + + + align:start position:0% +we'll sequence that gene we'll type +every damn variant we can find in that + + align:start position:0% +every damn variant we can find in that + + + align:start position:0% +every damn variant we can find in that +gene in in the population and look at + + align:start position:0% +gene in in the population and look at + + + align:start position:0% +gene in in the population and look at +every thing that could be related to a + + align:start position:0% +every thing that could be related to a + + + align:start position:0% +every thing that could be related to a +an interesting phenotype because we're + + align:start position:0% +an interesting phenotype because we're + + + align:start position:0% +an interesting phenotype because we're +searching for clues to how to help our + + align:start position:0% +searching for clues to how to help our + + + align:start position:0% +searching for clues to how to help our +molecular biology colleagues in uh + + align:start position:0% +molecular biology colleagues in uh + + + align:start position:0% +molecular biology colleagues in uh +trying to help them + + align:start position:0% +trying to help them + + + align:start position:0% +trying to help them +figure out what the gene is actually + + align:start position:0% +figure out what the gene is actually + + + align:start position:0% +figure out what the gene is actually +doing + + align:start position:0% +doing + + + align:start position:0% +doing +um + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +uh well you could do that i mean we're + + align:start position:0% +uh well you could do that i mean we're + + + align:start position:0% +uh well you could do that i mean we're +trying to work with this guy + + align:start position:0% +trying to work with this guy + + + align:start position:0% +trying to work with this guy +he's got people in his lab who + + align:start position:0% +he's got people in his lab who + + + align:start position:0% +he's got people in his lab who +have ideas about how to + + align:start position:0% +have ideas about how to + + + align:start position:0% +have ideas about how to +uh + + align:start position:0% +uh + + + align:start position:0% +uh +get clues + + align:start position:0% +get clues + + + align:start position:0% +get clues +so + + align:start position:0% +so + + + align:start position:0% +so +like the stuff that drazen showed you + + align:start position:0% +like the stuff that drazen showed you + + + align:start position:0% +like the stuff that drazen showed you +last week + + align:start position:0% +last week + + + align:start position:0% +last week +that gene crh1 + + align:start position:0% +that gene crh1 + + + align:start position:0% +that gene crh1 +we + + align:start position:0% +we + + + align:start position:0% +we +know there's a relationship to steroid + + align:start position:0% +know there's a relationship to steroid + + + align:start position:0% +know there's a relationship to steroid +treatment response + + align:start position:0% +treatment response + + + align:start position:0% +treatment response +but we don't know + + align:start position:0% +but we don't know + + + align:start position:0% +but we don't know +what the variant is in the gene so we + + align:start position:0% +what the variant is in the gene so we + + + align:start position:0% +what the variant is in the gene so we +sequence the gene completely + + align:start position:0% +sequence the gene completely + + + align:start position:0% +sequence the gene completely +and now we've got two indels + + align:start position:0% +and now we've got two indels + + + align:start position:0% +and now we've got two indels +in that gene that sit right at intron + + align:start position:0% +in that gene that sit right at intron + + + align:start position:0% +in that gene that sit right at intron +exon junctions so + + align:start position:0% +exon junctions so + + + align:start position:0% +exon junctions so +the presumed what we're thinking is that + + align:start position:0% +the presumed what we're thinking is that + + + align:start position:0% +the presumed what we're thinking is that +those + + align:start position:0% +those + + + align:start position:0% +those +insertion deletion polymorphisms may be + + align:start position:0% +insertion deletion polymorphisms may be + + + align:start position:0% +insertion deletion polymorphisms may be +changing alternative splice sites so + + align:start position:0% +changing alternative splice sites so + + + align:start position:0% +changing alternative splice sites so +we're going to have to try to prove that + + align:start position:0% +we're going to have to try to prove that + + + align:start position:0% +we're going to have to try to prove that +that's one of the hypotheses that we're + + align:start position:0% +that's one of the hypotheses that we're + + + align:start position:0% +that's one of the hypotheses that we're +going to investigate in the renewal of + + align:start position:0% +going to investigate in the renewal of + + + align:start position:0% +going to investigate in the renewal of +the grant is trying to look at that + + align:start position:0% +the grant is trying to look at that + + + align:start position:0% +the grant is trying to look at that +um we also + + align:start position:0% +um we also + + + align:start position:0% +um we also +uh um so + + align:start position:0% +uh um so + + + align:start position:0% +uh um so +you know you have to let the gene tell + + align:start position:0% +you know you have to let the gene tell + + + align:start position:0% +you know you have to let the gene tell +you + + align:start position:0% + + + + align:start position:0% + +where its variation is and and how it + + align:start position:0% +where its variation is and and how it + + + align:start position:0% +where its variation is and and how it +might be + + align:start position:0% +might be + + + align:start position:0% +might be +uh + + align:start position:0% +uh + + + align:start position:0% +uh +contributing to phenotype + + align:start position:0% +contributing to phenotype + + + align:start position:0% +contributing to phenotype +and so + + align:start position:0% +and so + + + align:start position:0% +and so +uh the first thing usually is to + + align:start position:0% +uh the first thing usually is to + + + align:start position:0% +uh the first thing usually is to +sequence the gene completely second + + align:start position:0% +sequence the gene completely second + + + align:start position:0% +sequence the gene completely second +thing would be to then do a very careful + + align:start position:0% +thing would be to then do a very careful + + + align:start position:0% +thing would be to then do a very careful +analysis of the + + align:start position:0% +analysis of the + + + align:start position:0% +analysis of the +new variants and the re-sequenced + + align:start position:0% +new variants and the re-sequenced + + + align:start position:0% +new variants and the re-sequenced +variants that you found in relationship + + align:start position:0% +variants that you found in relationship + + + align:start position:0% +variants that you found in relationship +to the phenotype of interest + + align:start position:0% +to the phenotype of interest + + + align:start position:0% +to the phenotype of interest +for phenotypes of interest and see if + + align:start position:0% +for phenotypes of interest and see if + + + align:start position:0% +for phenotypes of interest and see if +you can find + + align:start position:0% +you can find + + + align:start position:0% +you can find +either haplotypes or + + align:start position:0% +either haplotypes or + + + align:start position:0% +either haplotypes or +individual snips or insertion deletion + + align:start position:0% +individual snips or insertion deletion + + + align:start position:0% +individual snips or insertion deletion +polymorphisms or transcription factor + + align:start position:0% +polymorphisms or transcription factor + + + align:start position:0% +polymorphisms or transcription factor +binding sites are things that could + + align:start position:0% +binding sites are things that could + + + align:start position:0% +binding sites are things that could +potentially explain + + align:start position:0% +potentially explain + + + align:start position:0% +potentially explain +the genetic association so then you can + + align:start position:0% +the genetic association so then you can + + + align:start position:0% +the genetic association so then you can +do that and then you have to go into an + + align:start position:0% +do that and then you have to go into an + + + align:start position:0% +do that and then you have to go into an +animal model + + align:start position:0% +animal model + + + align:start position:0% +animal model +and test those + + align:start position:0% +and test those + + + align:start position:0% +and test those +in a more rigorous way usually so scott + + align:start position:0% +in a more rigorous way usually so scott + + + align:start position:0% +in a more rigorous way usually so scott +how far off do you think is the day when + + align:start position:0% +how far off do you think is the day when + + + align:start position:0% +how far off do you think is the day when +a commission of the brigham + + align:start position:0% +a commission of the brigham + + + align:start position:0% +a commission of the brigham +will be able to come with you and say i + + align:start position:0% +will be able to come with you and say i + + + align:start position:0% +will be able to come with you and say i +have a disease + + align:start position:0% +have a disease + + + align:start position:0% +have a disease +i have 500 patients cases and 500 + + align:start position:0% +i have 500 patients cases and 500 + + + align:start position:0% +i have 500 patients cases and 500 +controls + + align:start position:0% +controls + + + align:start position:0% +controls +i think + + align:start position:0% +i think + + + align:start position:0% +i think +i want to verify that with a climate + + align:start position:0% +i want to verify that with a climate + + + align:start position:0% +i want to verify that with a climate +that this is + + align:start position:0% +that this is + + + align:start position:0% +that this is +on the long arm of the chromosome + + align:start position:0% +on the long arm of the chromosome + + + align:start position:0% +on the long arm of the chromosome +and i want to do this + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% + + + + align:start position:0% + +so you're really asking the question is + + align:start position:0% +so you're really asking the question is + + + align:start position:0% +so you're really asking the question is +i think the question you're asking is + + align:start position:0% +i think the question you're asking is + + + align:start position:0% +i think the question you're asking is +how far away is whole genome association + + align:start position:0% +how far away is whole genome association + + + align:start position:0% +how far away is whole genome association +how far away is whole genomic + + align:start position:0% +how far away is whole genomic + + + align:start position:0% +how far away is whole genomic +association where it's within the reach + + align:start position:0% +association where it's within the reach + + + align:start position:0% +association where it's within the reach +of + + align:start position:0% +of + + + align:start position:0% +of +significant but not impossible clinical + + align:start position:0% +significant but not impossible clinical + + + align:start position:0% +significant but not impossible clinical +studies + + align:start position:0% +studies + + + align:start position:0% +studies +uh max three years + + align:start position:0% +uh max three years + + + align:start position:0% +uh max three years +max + + align:start position:0% + + + + align:start position:0% + +all right + + align:start position:0% +all right + + + align:start position:0% +all right +i mean george church + + align:start position:0% + + + + align:start position:0% + +it's all about the genotyping costs zach + + align:start position:0% + + + + align:start position:0% + +i mean he + + align:start position:0% +i mean he + + + align:start position:0% +i mean he +he listen he thinks he's + + align:start position:0% +he listen he thinks he's + + + align:start position:0% +he listen he thinks he's +close to + + align:start position:0% + + + + align:start position:0% + +you know the + + align:start position:0% +you know the + + + align:start position:0% +you know the +thousand dollar genome so if he's really + + align:start position:0% +thousand dollar genome so if he's really + + + align:start position:0% +thousand dollar genome so if he's really +close to the thousand dollar genome and + + align:start position:0% +close to the thousand dollar genome and + + + align:start position:0% +close to the thousand dollar genome and +genotyping snip genotyping costs really + + align:start position:0% +genotyping snip genotyping costs really + + + align:start position:0% +genotyping snip genotyping costs really +drop continue to drop as dramatically as + + align:start position:0% +drop continue to drop as dramatically as + + + align:start position:0% +drop continue to drop as dramatically as +they've dropped over the last three + + align:start position:0% +they've dropped over the last three + + + align:start position:0% +they've dropped over the last three +years + + align:start position:0% +years + + + align:start position:0% +years +i would see whole genome association + + align:start position:0% +i would see whole genome association + + + align:start position:0% +i would see whole genome association +being within the range + + align:start position:0% +being within the range + + + align:start position:0% +being within the range +of + + align:start position:0% +of + + + align:start position:0% +of +a a + + align:start position:0% +a a + + + align:start position:0% +a a +reasonable budget + + align:start position:0% +reasonable budget + + + align:start position:0% +reasonable budget +you know in a two or three year period + + align:start position:0% +you know in a two or three year period + + + align:start position:0% +you know in a two or three year period +of time + + align:start position:0% +of time + + + align:start position:0% +of time +all right on that note thanks very much \ No newline at end of file diff --git a/j0Bhj4eCCws.txt b/j0Bhj4eCCws.txt new file mode 100644 index 0000000000000000000000000000000000000000..434d2b5993d32333b6e311797264ad6fa935e3a6 --- /dev/null +++ b/j0Bhj4eCCws.txt @@ -0,0 +1,4331 @@ +align:start position:0% + +All right. It is the last session. You + + align:start position:0% +All right. It is the last session. You + + + align:start position:0% +All right. It is the last session. You +have survived the first day almost. + + align:start position:0% +have survived the first day almost. + + + align:start position:0% +have survived the first day almost. +And + + align:start position:0% +And + + + align:start position:0% +And +I'm really excited about this session uh + + align:start position:0% +I'm really excited about this session uh + + + align:start position:0% +I'm really excited about this session uh +because we started the day we started + + align:start position:0% +because we started the day we started + + + align:start position:0% +because we started the day we started +the day looking at the planetary scale + + align:start position:0% +the day looking at the planetary scale + + + align:start position:0% +the day looking at the planetary scale +and + + align:start position:0% +and + + + align:start position:0% +and +honestly from a little bit of a a + + align:start position:0% +honestly from a little bit of a a + + + align:start position:0% +honestly from a little bit of a a +slightly grim perspective. I don't think + + align:start position:0% +slightly grim perspective. I don't think + + + align:start position:0% +slightly grim perspective. I don't think +anyone left that session feeling really + + align:start position:0% +anyone left that session feeling really + + + align:start position:0% +anyone left that session feeling really +light and excited about the state of the + + align:start position:0% +light and excited about the state of the + + + align:start position:0% +light and excited about the state of the +world. + + align:start position:0% +world. + + + align:start position:0% +world. +Um so now we proceeded to talk about + + align:start position:0% +Um so now we proceeded to talk about + + + align:start position:0% +Um so now we proceeded to talk about +people because no change happens without + + align:start position:0% +people because no change happens without + + + align:start position:0% +people because no change happens without +people and then about what people can do + + align:start position:0% +people and then about what people can do + + + align:start position:0% +people and then about what people can do +in set rules policy and now we are going + + align:start position:0% +in set rules policy and now we are going + + + align:start position:0% +in set rules policy and now we are going +to go ahead and go back to the scale + + align:start position:0% +to go ahead and go back to the scale + + + align:start position:0% +to go ahead and go back to the scale +question but from the perspective + + align:start position:0% +question but from the perspective + + + align:start position:0% +question but from the perspective +of with people with technology with + + align:start position:0% +of with people with technology with + + + align:start position:0% +of with people with technology with +ideas with rules + + align:start position:0% +ideas with rules + + + align:start position:0% +ideas with rules +what can we accomplish? + + align:start position:0% + + + + align:start position:0% + +Um, so I hope we're going to end the day + + align:start position:0% +Um, so I hope we're going to end the day + + + align:start position:0% +Um, so I hope we're going to end the day +with a lot of excitement. Um, and we + + align:start position:0% +with a lot of excitement. Um, and we + + + align:start position:0% +with a lot of excitement. Um, and we +also have two um relatively new friends + + align:start position:0% +also have two um relatively new friends + + + align:start position:0% +also have two um relatively new friends +of mine who I deeply admire and I'm + + align:start position:0% +of mine who I deeply admire and I'm + + + align:start position:0% +of mine who I deeply admire and I'm +excited to have joining us. Both not + + align:start position:0% +excited to have joining us. Both not + + + align:start position:0% +excited to have joining us. Both not +present. So we have two videos + + align:start position:0% +present. So we have two videos + + + align:start position:0% +present. So we have two videos +sandwiching our our session today. Um, + + align:start position:0% +sandwiching our our session today. Um, + + + align:start position:0% +sandwiching our our session today. Um, +and I am going to start with one uh the + + align:start position:0% +and I am going to start with one uh the + + + align:start position:0% +and I am going to start with one uh the +growth of gens in Europe. Sanjie Kumar + + align:start position:0% +growth of gens in Europe. Sanjie Kumar + + + align:start position:0% +growth of gens in Europe. Sanjie Kumar +is joining us I believe. Are you in + + align:start position:0% +is joining us I believe. Are you in + + + align:start position:0% +is joining us I believe. Are you in +Brussels Sanjie? Yes, I am. Lovely. + + align:start position:0% +Brussels Sanjie? Yes, I am. Lovely. + + + align:start position:0% +Brussels Sanjie? Yes, I am. Lovely. +Lovely evening in Brussels. You're + + align:start position:0% +Lovely evening in Brussels. You're + + + align:start position:0% +Lovely evening in Brussels. You're +>> you lovely to see you up there. + + align:start position:0% +>> you lovely to see you up there. + + + align:start position:0% +>> you lovely to see you up there. +>> Uh and I am going to ask you to + + align:start position:0% +>> Uh and I am going to ask you to + + + align:start position:0% +>> Uh and I am going to ask you to +introduce yourself to everyone and then + + align:start position:0% +introduce yourself to everyone and then + + + align:start position:0% +introduce yourself to everyone and then +go ahead and proceed with your + + align:start position:0% +go ahead and proceed with your + + + align:start position:0% +go ahead and proceed with your +presentation. + + align:start position:0% +presentation. + + + align:start position:0% +presentation. +>> Brilliant. Thank you. Thank you so much + + align:start position:0% +>> Brilliant. Thank you. Thank you so much + + + align:start position:0% +>> Brilliant. Thank you. Thank you so much +Z. Firstly for the kind introduction and + + align:start position:0% +Z. Firstly for the kind introduction and + + + align:start position:0% +Z. Firstly for the kind introduction and +for the the opportunity to come and uh + + align:start position:0% +for the the opportunity to come and uh + + + align:start position:0% +for the the opportunity to come and uh +talk to everybody in the room. Um my + + align:start position:0% +talk to everybody in the room. Um my + + + align:start position:0% +talk to everybody in the room. Um my +name is Sanjikuma. + + align:start position:0% +name is Sanjikuma. + + + align:start position:0% +name is Sanjikuma. +I'm the head of policy at the European + + align:start position:0% +I'm the head of policy at the European + + + align:start position:0% +I'm the head of policy at the European +Geothermal Energy Council, which means + + align:start position:0% +Geothermal Energy Council, which means + + + align:start position:0% +Geothermal Energy Council, which means +that my role is to really grow markets + + align:start position:0% +that my role is to really grow markets + + + align:start position:0% +that my role is to really grow markets +for geothermal across Europe. Um, that's + + align:start position:0% +for geothermal across Europe. Um, that's + + + align:start position:0% +for geothermal across Europe. Um, that's +the European Union, but also countries + + align:start position:0% +the European Union, but also countries + + + align:start position:0% +the European Union, but also countries +outside such as, um, uh, Iceland, + + align:start position:0% +outside such as, um, uh, Iceland, + + + align:start position:0% +outside such as, um, uh, Iceland, +Norway, uh, down to Turkey, the Western + + align:start position:0% +Norway, uh, down to Turkey, the Western + + + align:start position:0% +Norway, uh, down to Turkey, the Western +Balkans, and Ukraine. So, I look at what + + align:start position:0% +Balkans, and Ukraine. So, I look at what + + + align:start position:0% +Balkans, and Ukraine. So, I look at what +are the regulatory frameworks, what are + + align:start position:0% +are the regulatory frameworks, what are + + + align:start position:0% +are the regulatory frameworks, what are +the financial structures that we need to + + align:start position:0% +the financial structures that we need to + + + align:start position:0% +the financial structures that we need to +grow geothermal. And what I'm going to + + align:start position:0% +grow geothermal. And what I'm going to + + + align:start position:0% +grow geothermal. And what I'm going to +do is kind of share some of the + + align:start position:0% +do is kind of share some of the + + + align:start position:0% +do is kind of share some of the +experiences that we've had in Europe. + + align:start position:0% +experiences that we've had in Europe. + + + align:start position:0% +experiences that we've had in Europe. +Um, let me start off with some pretty uh + + align:start position:0% +Um, let me start off with some pretty uh + + + align:start position:0% +Um, let me start off with some pretty uh +basic uh things about uh the kind of the + + align:start position:0% +basic uh things about uh the kind of the + + + align:start position:0% +basic uh things about uh the kind of the +content of Europe. Um, and then I'm + + align:start position:0% +content of Europe. Um, and then I'm + + + align:start position:0% +content of Europe. Um, and then I'm +going to kind of give you some ideas + + align:start position:0% +going to kind of give you some ideas + + + align:start position:0% +going to kind of give you some ideas +about how you can perhaps build upon the + + align:start position:0% +about how you can perhaps build upon the + + + align:start position:0% +about how you can perhaps build upon the +session that you've had before the + + align:start position:0% +session that you've had before the + + + align:start position:0% +session that you've had before the +discussions you've had uh this morning + + align:start position:0% +discussions you've had uh this morning + + + align:start position:0% +discussions you've had uh this morning +and then the discussions you're going to + + align:start position:0% +and then the discussions you're going to + + + align:start position:0% +and then the discussions you're going to +have um uh tomorrow. So let's start off + + align:start position:0% +have um uh tomorrow. So let's start off + + + align:start position:0% +have um uh tomorrow. So let's start off +with some basics. uh there about Europe + + align:start position:0% +with some basics. uh there about Europe + + + align:start position:0% +with some basics. uh there about Europe +is uh generally um our um heat gradient + + align:start position:0% +is uh generally um our um heat gradient + + + align:start position:0% +is uh generally um our um heat gradient +is quite low. We have lower temperatures + + align:start position:0% +is quite low. We have lower temperatures + + + align:start position:0% +is quite low. We have lower temperatures +so we don't have a lot of power + + align:start position:0% +so we don't have a lot of power + + + align:start position:0% +so we don't have a lot of power +generation. Uh what we do have is a lot + + align:start position:0% +generation. Uh what we do have is a lot + + + align:start position:0% +generation. Uh what we do have is a lot +of heating. Um our market is geared + + align:start position:0% +of heating. Um our market is geared + + + align:start position:0% +of heating. Um our market is geared +towards heating and that heat market is + + align:start position:0% +towards heating and that heat market is + + + align:start position:0% +towards heating and that heat market is +transitioning. As it stands at the + + align:start position:0% +transitioning. As it stands at the + + + align:start position:0% +transitioning. As it stands at the +moment there are about 10 million people + + align:start position:0% +moment there are about 10 million people + + + align:start position:0% +moment there are about 10 million people +across Europe who benefit from different + + align:start position:0% +across Europe who benefit from different + + + align:start position:0% +across Europe who benefit from different +types of geothermal heat pumps. These + + align:start position:0% +types of geothermal heat pumps. These + + + align:start position:0% +types of geothermal heat pumps. These +are small uh closed loop systems to uh + + align:start position:0% +are small uh closed loop systems to uh + + + align:start position:0% +are small uh closed loop systems to uh +large openloop systems. uh we have + + align:start position:0% +large openloop systems. uh we have + + + align:start position:0% +large openloop systems. uh we have +district heating uh direct use um and + + align:start position:0% +district heating uh direct use um and + + + align:start position:0% +district heating uh direct use um and +that's really for uh cities. We also in + + align:start position:0% +that's really for uh cities. We also in + + + align:start position:0% +that's really for uh cities. We also in +a few countries have a lot of district + + align:start position:0% +a few countries have a lot of district + + + align:start position:0% +a few countries have a lot of district +heating systems just for the agriculture + + align:start position:0% +heating systems just for the agriculture + + + align:start position:0% +heating systems just for the agriculture +community. So when it comes to thinking + + align:start position:0% +community. So when it comes to thinking + + + align:start position:0% +community. So when it comes to thinking +about your your doing new kind of + + align:start position:0% +about your your doing new kind of + + + align:start position:0% +about your your doing new kind of +customer base I know a lot of the + + align:start position:0% +customer base I know a lot of the + + + align:start position:0% +customer base I know a lot of the +conversation is going to be around + + align:start position:0% +conversation is going to be around + + + align:start position:0% +conversation is going to be around +residential consumers. There is a whole + + align:start position:0% +residential consumers. There is a whole + + + align:start position:0% +residential consumers. There is a whole +world outside the residential space. Um + + align:start position:0% +world outside the residential space. Um + + + align:start position:0% +world outside the residential space. Um +and people like farmers we found in + + align:start position:0% +and people like farmers we found in + + + align:start position:0% +and people like farmers we found in +Europe are very very vocal and generally + + align:start position:0% +Europe are very very vocal and generally + + + align:start position:0% +Europe are very very vocal and generally +tend to get their own way. So and they + + align:start position:0% +tend to get their own way. So and they + + + align:start position:0% +tend to get their own way. So and they +have a desire to have a permanent supply + + align:start position:0% +have a desire to have a permanent supply + + + align:start position:0% +have a desire to have a permanent supply +of heating and cooling. So it's a + + align:start position:0% +of heating and cooling. So it's a + + + align:start position:0% +of heating and cooling. So it's a +fantastic customer base. Factories. + + align:start position:0% +fantastic customer base. Factories. + + + align:start position:0% +fantastic customer base. Factories. +There's some of the big car makers in + + align:start position:0% +There's some of the big car makers in + + + align:start position:0% +There's some of the big car makers in +Europe have just uh uh installed + + align:start position:0% +Europe have just uh uh installed + + + align:start position:0% +Europe have just uh uh installed +geothermal heating and cooling systems + + align:start position:0% +geothermal heating and cooling systems + + + align:start position:0% +geothermal heating and cooling systems +um uh for their uh for their factories, + + align:start position:0% +um uh for their uh for their factories, + + + align:start position:0% +um uh for their uh for their factories, +for their head offices. It's it's really + + align:start position:0% +for their head offices. It's it's really + + + align:start position:0% +for their head offices. It's it's really +big. And of course, we've got 11 million + + align:start position:0% +big. And of course, we've got 11 million + + + align:start position:0% +big. And of course, we've got 11 million +consumers tapped into geothermal power. + + align:start position:0% +consumers tapped into geothermal power. + + + align:start position:0% +consumers tapped into geothermal power. +Um, but what I want to do is just to + + align:start position:0% +Um, but what I want to do is just to + + + align:start position:0% +Um, but what I want to do is just to +deep dive a little bit into what the + + align:start position:0% +deep dive a little bit into what the + + + align:start position:0% +deep dive a little bit into what the +situation in Europe is, why it's perhaps + + align:start position:0% +situation in Europe is, why it's perhaps + + + align:start position:0% +situation in Europe is, why it's perhaps +different to the US, but the challenges + + align:start position:0% +different to the US, but the challenges + + + align:start position:0% +different to the US, but the challenges +that we face are the same challenges + + align:start position:0% +that we face are the same challenges + + + align:start position:0% +that we face are the same challenges +that you're going to face as you start + + align:start position:0% +that you're going to face as you start + + + align:start position:0% +that you're going to face as you start +to scale up uh geothermal in particular, + + align:start position:0% +to scale up uh geothermal in particular, + + + align:start position:0% +to scale up uh geothermal in particular, +especially network geothermal. So, let's + + align:start position:0% +especially network geothermal. So, let's + + + align:start position:0% +especially network geothermal. So, let's +start off with some basics. Um like + + align:start position:0% +start off with some basics. Um like + + + align:start position:0% +start off with some basics. Um like +everywhere else in the world, the bulk + + align:start position:0% +everywhere else in the world, the bulk + + + align:start position:0% +everywhere else in the world, the bulk +of our heating and cooling supply is + + align:start position:0% +of our heating and cooling supply is + + + align:start position:0% +of our heating and cooling supply is +fossilbased. Um where we have + + align:start position:0% +fossilbased. Um where we have + + + align:start position:0% +fossilbased. Um where we have +non-fossilbased heating cooling, it's + + align:start position:0% +non-fossilbased heating cooling, it's + + + align:start position:0% +non-fossilbased heating cooling, it's +largely coming from combustible biomass. + + align:start position:0% +largely coming from combustible biomass. + + + align:start position:0% +largely coming from combustible biomass. +Um and over the last five or six years, + + align:start position:0% +Um and over the last five or six years, + + + align:start position:0% +Um and over the last five or six years, +there's been a quite a ugly discussion + + align:start position:0% +there's been a quite a ugly discussion + + + align:start position:0% +there's been a quite a ugly discussion +around toning down the amount of biomass + + align:start position:0% +around toning down the amount of biomass + + + align:start position:0% +around toning down the amount of biomass +uh to just focusing on that can be that + + align:start position:0% +uh to just focusing on that can be that + + + align:start position:0% +uh to just focusing on that can be that +which can be sustainably sourced. And + + align:start position:0% +which can be sustainably sourced. And + + + align:start position:0% +which can be sustainably sourced. And +what that's effectively done is put a + + align:start position:0% +what that's effectively done is put a + + + align:start position:0% +what that's effectively done is put a +ceiling on the amount of biomass we're + + align:start position:0% +ceiling on the amount of biomass we're + + + align:start position:0% +ceiling on the amount of biomass we're +going to use uh in heating. So the + + align:start position:0% +going to use uh in heating. So the + + + align:start position:0% +going to use uh in heating. So the +growth market that they've had in the + + align:start position:0% +growth market that they've had in the + + + align:start position:0% +growth market that they've had in the +past is going to start to diminish. And + + align:start position:0% +past is going to start to diminish. And + + + align:start position:0% +past is going to start to diminish. And +what that's really doing is it's kind of + + align:start position:0% +what that's really doing is it's kind of + + + align:start position:0% +what that's really doing is it's kind of +paving the way for um heat pumps um and + + align:start position:0% +paving the way for um heat pumps um and + + + align:start position:0% +paving the way for um heat pumps um and +for kind of direct use geothermal. And + + align:start position:0% +for kind of direct use geothermal. And + + + align:start position:0% +for kind of direct use geothermal. And +when we talk about heat pumps in a + + align:start position:0% +when we talk about heat pumps in a + + + align:start position:0% +when we talk about heat pumps in a +European context, almost everybody + + align:start position:0% +European context, almost everybody + + + align:start position:0% +European context, almost everybody +thinks of airsource heat pumps. So the + + align:start position:0% +thinks of airsource heat pumps. So the + + + align:start position:0% +thinks of airsource heat pumps. So the +language that we use to describe uh + + align:start position:0% +language that we use to describe uh + + + align:start position:0% +language that we use to describe uh +electric heating with uh ground source + + align:start position:0% +electric heating with uh ground source + + + align:start position:0% +electric heating with uh ground source +heat pumps, geothermal heat pumps is + + align:start position:0% +heat pumps, geothermal heat pumps is + + + align:start position:0% +heat pumps, geothermal heat pumps is +something we're going to come back to + + align:start position:0% +something we're going to come back to + + + align:start position:0% +something we're going to come back to +later on. We also have a legacy system + + align:start position:0% +later on. We also have a legacy system + + + align:start position:0% +later on. We also have a legacy system +of district heating. So, a lot of these + + align:start position:0% +of district heating. So, a lot of these + + + align:start position:0% +of district heating. So, a lot of these +are in former Soviet countries, but you + + align:start position:0% +are in former Soviet countries, but you + + + align:start position:0% +are in former Soviet countries, but you +also have them in Baltic places, sorry, + + align:start position:0% +also have them in Baltic places, sorry, + + + align:start position:0% +also have them in Baltic places, sorry, +in the Scandinavian countries such as + + align:start position:0% +in the Scandinavian countries such as + + + align:start position:0% +in the Scandinavian countries such as +Denmark um and Finland um uh where you + + align:start position:0% +Denmark um and Finland um uh where you + + + align:start position:0% +Denmark um and Finland um uh where you +have effectively heat networks that were + + align:start position:0% +have effectively heat networks that were + + + align:start position:0% +have effectively heat networks that were +built on the back of a a coal plant, a + + align:start position:0% +built on the back of a a coal plant, a + + + align:start position:0% +built on the back of a a coal plant, a +gas plant or a waste incineration plant, + + align:start position:0% +gas plant or a waste incineration plant, + + + align:start position:0% +gas plant or a waste incineration plant, +and you take the excess heat and you + + align:start position:0% +and you take the excess heat and you + + + align:start position:0% +and you take the excess heat and you +pump it at high temperatures at vast + + align:start position:0% +pump it at high temperatures at vast + + + align:start position:0% +pump it at high temperatures at vast +quantities through um a network. Um + + align:start position:0% +quantities through um a network. Um + + + align:start position:0% +quantities through um a network. Um +these are extremely inefficient. They're + + align:start position:0% +these are extremely inefficient. They're + + + align:start position:0% +these are extremely inefficient. They're +very very polluting. And what's been + + align:start position:0% +very very polluting. And what's been + + + align:start position:0% +very very polluting. And what's been +happening over the last 20 years is that + + align:start position:0% +happening over the last 20 years is that + + + align:start position:0% +happening over the last 20 years is that +people have just been jumping using uh + + align:start position:0% +people have just been jumping using uh + + + align:start position:0% +people have just been jumping using uh +things like airsource heat pumps, + + align:start position:0% +things like airsource heat pumps, + + + align:start position:0% +things like airsource heat pumps, +geothermal heat pumps to get themselves + + align:start position:0% +geothermal heat pumps to get themselves + + + align:start position:0% +geothermal heat pumps to get themselves +off of these district heating systems. + + align:start position:0% +off of these district heating systems. + + + align:start position:0% +off of these district heating systems. +So this industry has a tarnished + + align:start position:0% +So this industry has a tarnished + + + align:start position:0% +So this industry has a tarnished +reputation. But if we're serious about + + align:start position:0% +reputation. But if we're serious about + + + align:start position:0% +reputation. But if we're serious about +decarbonization, we're going to have to + + align:start position:0% +decarbonization, we're going to have to + + + align:start position:0% +decarbonization, we're going to have to +rethink uh district heating and cooling + + align:start position:0% +rethink uh district heating and cooling + + + align:start position:0% +rethink uh district heating and cooling +systems. And this becomes really + + align:start position:0% +systems. And this becomes really + + + align:start position:0% +systems. And this becomes really +important to you. So it's within that + + align:start position:0% +important to you. So it's within that + + + align:start position:0% +important to you. So it's within that +context of a multitude of supplies. um + + align:start position:0% +context of a multitude of supplies. um + + + align:start position:0% +context of a multitude of supplies. um +renewable energies incumbent fossils + + align:start position:0% +renewable energies incumbent fossils + + + align:start position:0% +renewable energies incumbent fossils +that network geothermal has to operate + + align:start position:0% +that network geothermal has to operate + + + align:start position:0% +that network geothermal has to operate +in. So that's our competition base. Um + + align:start position:0% +in. So that's our competition base. Um + + + align:start position:0% +in. So that's our competition base. Um +the other thing which is quite important + + align:start position:0% +the other thing which is quite important + + + align:start position:0% +the other thing which is quite important +to us and will become an issue for you + + align:start position:0% +to us and will become an issue for you + + + align:start position:0% +to us and will become an issue for you +later on um is the fact that we have a + + align:start position:0% +later on um is the fact that we have a + + + align:start position:0% +later on um is the fact that we have a +largely densely populated uh + + align:start position:0% +largely densely populated uh + + + align:start position:0% +largely densely populated uh +geographical spaces. So we don't have + + align:start position:0% +geographical spaces. So we don't have + + + align:start position:0% +geographical spaces. So we don't have +vast lands in which we can do drilling + + align:start position:0% +vast lands in which we can do drilling + + + align:start position:0% +vast lands in which we can do drilling +and great uh um uh big uh uh uh + + align:start position:0% +and great uh um uh big uh uh uh + + + align:start position:0% +and great uh um uh big uh uh uh +networks. we have to operate in tightly + + align:start position:0% +networks. we have to operate in tightly + + + align:start position:0% +networks. we have to operate in tightly +confined spaces. Um, and environmental + + align:start position:0% +confined spaces. Um, and environmental + + + align:start position:0% +confined spaces. Um, and environmental +protection is absolutely key. And what + + align:start position:0% +protection is absolutely key. And what + + + align:start position:0% +protection is absolutely key. And what +we found is is that as the geothermal + + align:start position:0% +we found is is that as the geothermal + + + align:start position:0% +we found is is that as the geothermal +sector grows, the regulators, + + align:start position:0% +sector grows, the regulators, + + + align:start position:0% +sector grows, the regulators, +particularly those that are looking at + + align:start position:0% +particularly those that are looking at + + + align:start position:0% +particularly those that are looking at +protecting water, + + align:start position:0% +protecting water, + + + align:start position:0% +protecting water, +drinking water, surface water, those + + align:start position:0% +drinking water, surface water, those + + + align:start position:0% +drinking water, surface water, those +that are very very nervous about uh kind + + align:start position:0% +that are very very nervous about uh kind + + + align:start position:0% +that are very very nervous about uh kind +of geothermal activities around them, + + align:start position:0% +of geothermal activities around them, + + + align:start position:0% +of geothermal activities around them, +but also are very concerned and are + + align:start position:0% +but also are very concerned and are + + + align:start position:0% +but also are very concerned and are +driven by the perception of negative + + align:start position:0% +driven by the perception of negative + + + align:start position:0% +driven by the perception of negative +impacts. This has in some cases slowed + + align:start position:0% +impacts. This has in some cases slowed + + + align:start position:0% +impacts. This has in some cases slowed +down a lot of growth that we've seen in + + align:start position:0% +down a lot of growth that we've seen in + + + align:start position:0% +down a lot of growth that we've seen in +in some of the the really advancing + + align:start position:0% +in some of the the really advancing + + + align:start position:0% +in some of the the really advancing +countries such as the Netherlands where + + align:start position:0% +countries such as the Netherlands where + + + align:start position:0% +countries such as the Netherlands where +now it's much harder to for us to get a + + align:start position:0% +now it's much harder to for us to get a + + + align:start position:0% +now it's much harder to for us to get a +permit. So permitting becomes an issue + + align:start position:0% +permit. So permitting becomes an issue + + + align:start position:0% +permit. So permitting becomes an issue +once you start to see a a reasonable + + align:start position:0% +once you start to see a a reasonable + + + align:start position:0% +once you start to see a a reasonable +size of growth um within uh your + + align:start position:0% +size of growth um within uh your + + + align:start position:0% +size of growth um within uh your +geothermal systems. The other two things + + align:start position:0% +geothermal systems. The other two things + + + align:start position:0% +geothermal systems. The other two things +from this one um is that when we often + + align:start position:0% +from this one um is that when we often + + + align:start position:0% +from this one um is that when we often +talk about geothermal in a European + + align:start position:0% +talk about geothermal in a European + + + align:start position:0% +talk about geothermal in a European +context, you can see from the three uh + + align:start position:0% +context, you can see from the three uh + + + align:start position:0% +context, you can see from the three uh +different types of uh geothermal heat + + align:start position:0% +different types of uh geothermal heat + + + align:start position:0% +different types of uh geothermal heat +pumps that we tend to focus on the first + + align:start position:0% +pumps that we tend to focus on the first + + + align:start position:0% +pumps that we tend to focus on the first +two. Um so vertical ball holds or uh two + + align:start position:0% +two. Um so vertical ball holds or uh two + + + align:start position:0% +two. Um so vertical ball holds or uh two +vertical ball holds linked to a + + align:start position:0% +vertical ball holds linked to a + + + align:start position:0% +vertical ball holds linked to a +hydrothermal source. The the the example + + align:start position:0% +hydrothermal source. The the the example + + + align:start position:0% +hydrothermal source. The the the example +that you have at the end with a loop + + align:start position:0% +that you have at the end with a loop + + + align:start position:0% +that you have at the end with a loop +that's quite shallow, there's just not + + align:start position:0% +that's quite shallow, there's just not + + + align:start position:0% +that's quite shallow, there's just not +enough space for that to really operate + + align:start position:0% +enough space for that to really operate + + + align:start position:0% +enough space for that to really operate +in a European context. So that means + + align:start position:0% +in a European context. So that means + + + align:start position:0% +in a European context. So that means +that we are looking at deeper pipes of + + align:start position:0% +that we are looking at deeper pipes of + + + align:start position:0% +that we are looking at deeper pipes of +drilling much more sophisticated + + align:start position:0% +drilling much more sophisticated + + + align:start position:0% +drilling much more sophisticated +uh and access to land that becomes more + + align:start position:0% +uh and access to land that becomes more + + + align:start position:0% +uh and access to land that becomes more +important as well as being able to get + + align:start position:0% +important as well as being able to get + + + align:start position:0% +important as well as being able to get +drilling rigs into uh people's gardens + + align:start position:0% +drilling rigs into uh people's gardens + + + align:start position:0% +drilling rigs into uh people's gardens +or whole uh down streets. One of the + + align:start position:0% +or whole uh down streets. One of the + + + align:start position:0% +or whole uh down streets. One of the +other things that's happened is in a few + + align:start position:0% +other things that's happened is in a few + + + align:start position:0% +other things that's happened is in a few +countries where the market has started + + align:start position:0% +countries where the market has started + + + align:start position:0% +countries where the market has started +to grow and it hasn't been regulated. Um + + align:start position:0% +to grow and it hasn't been regulated. Um + + + align:start position:0% +to grow and it hasn't been regulated. Um +we've had the issue of thermal + + align:start position:0% +we've had the issue of thermal + + + align:start position:0% +we've had the issue of thermal +interference where people have been kind + + align:start position:0% +interference where people have been kind + + + align:start position:0% +interference where people have been kind +of installing geothermal heat pumps in + + align:start position:0% +of installing geothermal heat pumps in + + + align:start position:0% +of installing geothermal heat pumps in +their back gardens but they're too close + + align:start position:0% +their back gardens but they're too close + + + align:start position:0% +their back gardens but they're too close +to somebody else's back garden and what + + align:start position:0% +to somebody else's back garden and what + + + align:start position:0% +to somebody else's back garden and what +you do then is they install a heat pump + + align:start position:0% +you do then is they install a heat pump + + + align:start position:0% +you do then is they install a heat pump +a geothermal heat pump and you're + + align:start position:0% +a geothermal heat pump and you're + + + align:start position:0% +a geothermal heat pump and you're +effectively diminishing the the overall + + align:start position:0% +effectively diminishing the the overall + + + align:start position:0% +effectively diminishing the the overall +thermal efficiency of that one. there's + + align:start position:0% +thermal efficiency of that one. there's + + + align:start position:0% +thermal efficiency of that one. there's +le lawsuits in Ireland uh for example it + + align:start position:0% +le lawsuits in Ireland uh for example it + + + align:start position:0% +le lawsuits in Ireland uh for example it +kind of again dampened down uh the + + align:start position:0% +kind of again dampened down uh the + + + align:start position:0% +kind of again dampened down uh the +growth in that market. So these are the + + align:start position:0% +growth in that market. So these are the + + + align:start position:0% +growth in that market. So these are the +kind of things that you're going to have + + align:start position:0% +kind of things that you're going to have + + + align:start position:0% +kind of things that you're going to have +to start to think through and for us the + + align:start position:0% +to start to think through and for us the + + + align:start position:0% +to start to think through and for us the +the the most important issue becomes + + align:start position:0% +the the most important issue becomes + + + align:start position:0% +the the most important issue becomes +permitting. Um you can see from the the + + align:start position:0% +permitting. Um you can see from the the + + + align:start position:0% +permitting. Um you can see from the the +map at the bottom that's a map of France + + align:start position:0% +map at the bottom that's a map of France + + + align:start position:0% +map at the bottom that's a map of France +at a 100 meter depth. um all the areas + + align:start position:0% +at a 100 meter depth. um all the areas + + + align:start position:0% +at a 100 meter depth. um all the areas +where if you're going to install a + + align:start position:0% +where if you're going to install a + + + align:start position:0% +where if you're going to install a +geothermal heat pump, the zones in + + align:start position:0% +geothermal heat pump, the zones in + + + align:start position:0% +geothermal heat pump, the zones in +green, you just have to do a simple + + align:start position:0% +green, you just have to do a simple + + + align:start position:0% +green, you just have to do a simple +email to your local government just to + + align:start position:0% +email to your local government just to + + + align:start position:0% +email to your local government just to +say, "Hey, this is where I'm installing + + align:start position:0% +say, "Hey, this is where I'm installing + + + align:start position:0% +say, "Hey, this is where I'm installing +my uh ball hole. Uh this is how this is + + align:start position:0% +my uh ball hole. Uh this is how this is + + + align:start position:0% +my uh ball hole. Uh this is how this is +the kind of depth it's going to be. Um + + align:start position:0% +the kind of depth it's going to be. Um + + + align:start position:0% +the kind of depth it's going to be. Um +and this is the kind of the geoloccation + + align:start position:0% +and this is the kind of the geoloccation + + + align:start position:0% +and this is the kind of the geoloccation +as possibly + + align:start position:0% +as possibly + + + align:start position:0% +as possibly +get it. Um and then that can be noted + + align:start position:0% +get it. Um and then that can be noted + + + align:start position:0% +get it. Um and then that can be noted +somewhere in a registry so that later on + + align:start position:0% +somewhere in a registry so that later on + + + align:start position:0% +somewhere in a registry so that later on +in maybe 1015 years time if somebody + + align:start position:0% +in maybe 1015 years time if somebody + + + align:start position:0% +in maybe 1015 years time if somebody +else wants to plot something they can + + align:start position:0% +else wants to plot something they can + + + align:start position:0% +else wants to plot something they can +very quickly check and see if there's + + align:start position:0% +very quickly check and see if there's + + + align:start position:0% +very quickly check and see if there's +going to be any kind of uh negative + + align:start position:0% +going to be any kind of uh negative + + + align:start position:0% +going to be any kind of uh negative +impact on any additional systems coming + + align:start position:0% +impact on any additional systems coming + + + align:start position:0% +impact on any additional systems coming +on. Then you have orange areas. Orange + + align:start position:0% +on. Then you have orange areas. Orange + + + align:start position:0% +on. Then you have orange areas. Orange +areas are sensitive subsurface activity + + align:start position:0% +areas are sensitive subsurface activity + + + align:start position:0% +areas are sensitive subsurface activity +and you need to get some form of an + + align:start position:0% +and you need to get some form of an + + + align:start position:0% +and you need to get some form of an +external recognition. Again this is for + + align:start position:0% +external recognition. Again this is for + + + align:start position:0% +external recognition. Again this is for +like a 100 m 200 m depth. there needs to + + align:start position:0% +like a 100 m 200 m depth. there needs to + + + align:start position:0% +like a 100 m 200 m depth. there needs to +be some form of third party assessment. + + align:start position:0% +be some form of third party assessment. + + + align:start position:0% +be some form of third party assessment. +And then the red areas are really where + + align:start position:0% +And then the red areas are really where + + + align:start position:0% +And then the red areas are really where +you need to have a full environmental + + align:start position:0% +you need to have a full environmental + + + align:start position:0% +you need to have a full environmental +impact assessment. They're very + + align:start position:0% +impact assessment. They're very + + + align:start position:0% +impact assessment. They're very +sensitive areas. Um and you can see that + + align:start position:0% +sensitive areas. Um and you can see that + + + align:start position:0% +sensitive areas. Um and you can see that +the what the kind of the the + + align:start position:0% +the what the kind of the the + + + align:start position:0% +the what the kind of the the +congregation of red dots um uh on the um + + align:start position:0% +congregation of red dots um uh on the um + + + align:start position:0% +congregation of red dots um uh on the um +on the eastern part of France is the + + align:start position:0% +on the eastern part of France is the + + + align:start position:0% +on the eastern part of France is the +Alsas region and the Alsas region is a + + align:start position:0% +Alsas region and the Alsas region is a + + + align:start position:0% +Alsas region and the Alsas region is a +volcanic uh region. There have been + + align:start position:0% +volcanic uh region. There have been + + + align:start position:0% +volcanic uh region. There have been +examples where people have drilled uh uh + + align:start position:0% +examples where people have drilled uh uh + + + align:start position:0% +examples where people have drilled uh uh +geothermal heat pumps and in one case + + align:start position:0% +geothermal heat pumps and in one case + + + align:start position:0% +geothermal heat pumps and in one case +actually uh damaged eight or nine + + align:start position:0% +actually uh damaged eight or nine + + + align:start position:0% +actually uh damaged eight or nine +properties within a village and that led + + align:start position:0% +properties within a village and that led + + + align:start position:0% +properties within a village and that led +to a variety of lawsuits um and really + + align:start position:0% +to a variety of lawsuits um and really + + + align:start position:0% +to a variety of lawsuits um and really +did give a negative impression to + + align:start position:0% +did give a negative impression to + + + align:start position:0% +did give a negative impression to +geothermal even though France is one of + + align:start position:0% +geothermal even though France is one of + + + align:start position:0% +geothermal even though France is one of +those countries that's really gung-ho um + + align:start position:0% +those countries that's really gung-ho um + + + align:start position:0% +those countries that's really gung-ho um +in our SAS the mayor of ours all of them + + align:start position:0% +in our SAS the mayor of ours all of them + + + align:start position:0% +in our SAS the mayor of ours all of them +don't like geothermal and they lump all + + align:start position:0% +don't like geothermal and they lump all + + + align:start position:0% +don't like geothermal and they lump all +geothermal into this uh basket so we + + align:start position:0% +geothermal into this uh basket so we + + + align:start position:0% +geothermal into this uh basket so we +need to be very very sensitive around + + align:start position:0% +need to be very very sensitive around + + + align:start position:0% +need to be very very sensitive around +the environmental impacts as your market + + align:start position:0% +the environmental impacts as your market + + + align:start position:0% +the environmental impacts as your market +starts to grow. Um, just a kind of quick + + align:start position:0% +starts to grow. Um, just a kind of quick + + + align:start position:0% +starts to grow. Um, just a kind of quick +thing, I I noticed you might not be able + + align:start position:0% +thing, I I noticed you might not be able + + + align:start position:0% +thing, I I noticed you might not be able +to see this graphic clearly, but you can + + align:start position:0% +to see this graphic clearly, but you can + + + align:start position:0% +to see this graphic clearly, but you can +blow up the screen when you get the the + + align:start position:0% +blow up the screen when you get the the + + + align:start position:0% +blow up the screen when you get the the +slides. Uh, Sweden is the largest + + align:start position:0% +slides. Uh, Sweden is the largest + + + align:start position:0% +slides. Uh, Sweden is the largest +country in terms of installed capacity. + + align:start position:0% +country in terms of installed capacity. + + + align:start position:0% +country in terms of installed capacity. +Germany second, uh, France is third. But + + align:start position:0% +Germany second, uh, France is third. But + + + align:start position:0% +Germany second, uh, France is third. But +really, the countries to look at if + + align:start position:0% +really, the countries to look at if + + + align:start position:0% +really, the countries to look at if +you're going to look at them are + + align:start position:0% +you're going to look at them are + + + align:start position:0% +you're going to look at them are +Belgium, the Netherlands, and Poland. + + align:start position:0% +Belgium, the Netherlands, and Poland. + + + align:start position:0% +Belgium, the Netherlands, and Poland. +These these really have grown uh roughly + + align:start position:0% +These these really have grown uh roughly + + + align:start position:0% +These these really have grown uh roughly +over the last decade. is a new entrance + + align:start position:0% +over the last decade. is a new entrance + + + align:start position:0% +over the last decade. is a new entrance +and that that's where all the innovation + + align:start position:0% +and that that's where all the innovation + + + align:start position:0% +and that that's where all the innovation +is happening and part of the innovation + + align:start position:0% +is happening and part of the innovation + + + align:start position:0% +is happening and part of the innovation +story in a country like Belgium is + + align:start position:0% +story in a country like Belgium is + + + align:start position:0% +story in a country like Belgium is +around network geos. I'm going to come + + align:start position:0% +around network geos. I'm going to come + + + align:start position:0% +around network geos. I'm going to come +on to that later on as to why that's the + + align:start position:0% +on to that later on as to why that's the + + + align:start position:0% +on to that later on as to why that's the +case. Um and then what you can see here + + align:start position:0% +case. Um and then what you can see here + + + align:start position:0% +case. Um and then what you can see here +is is on the figure 14 is the kind of + + align:start position:0% +is is on the figure 14 is the kind of + + + align:start position:0% +is is on the figure 14 is the kind of +the density of heat pumps uh per + + align:start position:0% +the density of heat pumps uh per + + + align:start position:0% +the density of heat pumps uh per +thousand households. So again Sweden is + + align:start position:0% +thousand households. So again Sweden is + + + align:start position:0% +thousand households. So again Sweden is +the most populous country. In Sweden, + + align:start position:0% +the most populous country. In Sweden, + + + align:start position:0% +the most populous country. In Sweden, +home buyers generally tend to look at + + align:start position:0% +home buyers generally tend to look at + + + align:start position:0% +home buyers generally tend to look at +five criteria uh when they're purchasing + + align:start position:0% +five criteria uh when they're purchasing + + + align:start position:0% +five criteria uh when they're purchasing +a new property, and a geothermal heat + + align:start position:0% +a new property, and a geothermal heat + + + align:start position:0% +a new property, and a geothermal heat +pump is normally the fourth orif fifth + + align:start position:0% +pump is normally the fourth orif fifth + + + align:start position:0% +pump is normally the fourth orif fifth +thing that they look at. Um before the + + align:start position:0% +thing that they look at. Um before the + + + align:start position:0% +thing that they look at. Um before the +construction industry collapsed in + + align:start position:0% +construction industry collapsed in + + + align:start position:0% +construction industry collapsed in +around 2000 2020, um geothermal houses + + align:start position:0% +around 2000 2020, um geothermal houses + + + align:start position:0% +around 2000 2020, um geothermal houses +with geothermal heat pumps sold for 12 + + align:start position:0% +with geothermal heat pumps sold for 12 + + + align:start position:0% +with geothermal heat pumps sold for 12 +to 15,000 euros more than houses that + + align:start position:0% +to 15,000 euros more than houses that + + + align:start position:0% +to 15,000 euros more than houses that +didn't. Um, so there was a clear + + align:start position:0% +didn't. Um, so there was a clear + + + align:start position:0% +didn't. Um, so there was a clear +recognition in a mature market that this + + align:start position:0% +recognition in a mature market that this + + + align:start position:0% +recognition in a mature market that this +really does add value to your property. + + align:start position:0% +really does add value to your property. + + + align:start position:0% +really does add value to your property. +Um, we haven't quite seen that in other + + align:start position:0% +Um, we haven't quite seen that in other + + + align:start position:0% +Um, we haven't quite seen that in other +countries, but as they start to grow and + + align:start position:0% +countries, but as they start to grow and + + + align:start position:0% +countries, but as they start to grow and +they become much more populous, we + + align:start position:0% +they become much more populous, we + + + align:start position:0% +they become much more populous, we +expect this to be the Estonia to be the + + align:start position:0% +expect this to be the Estonia to be the + + + align:start position:0% +expect this to be the Estonia to be the +next big country. Um, where you've got a + + align:start position:0% +next big country. Um, where you've got a + + + align:start position:0% +next big country. Um, where you've got a +lot of geothermal heat pumps in there. + + align:start position:0% +lot of geothermal heat pumps in there. + + + align:start position:0% +lot of geothermal heat pumps in there. +Um now what's happened is is that you've + + align:start position:0% +Um now what's happened is is that you've + + + align:start position:0% +Um now what's happened is is that you've +had kind of conventional story around + + align:start position:0% +had kind of conventional story around + + + align:start position:0% +had kind of conventional story around +district heating and uh um uh geothermal + + align:start position:0% +district heating and uh um uh geothermal + + + align:start position:0% +district heating and uh um uh geothermal +heat pumps and then out of nowhere + + align:start position:0% +heat pumps and then out of nowhere + + + align:start position:0% +heat pumps and then out of nowhere +network GFL came onto the scene and they + + align:start position:0% +network GFL came onto the scene and they + + + align:start position:0% +network GFL came onto the scene and they +were young and sexy and fresh and + + align:start position:0% +were young and sexy and fresh and + + + align:start position:0% +were young and sexy and fresh and +everyone's like oh my god I need to have + + align:start position:0% +everyone's like oh my god I need to have + + + align:start position:0% +everyone's like oh my god I need to have +this. Um but this has come uh really + + align:start position:0% +this. Um but this has come uh really + + + align:start position:0% +this. Um but this has come uh really +from three uh angles. So the first angle + + align:start position:0% +from three uh angles. So the first angle + + + align:start position:0% +from three uh angles. So the first angle +is is that district heating, you had a + + align:start position:0% +is is that district heating, you had a + + + align:start position:0% +is is that district heating, you had a +lot of people leaving district heating + + align:start position:0% +lot of people leaving district heating + + + align:start position:0% +lot of people leaving district heating +systems and what you started to find is + + align:start position:0% +systems and what you started to find is + + + align:start position:0% +systems and what you started to find is +that they were in communities and once + + align:start position:0% +that they were in communities and once + + + align:start position:0% +that they were in communities and once +you start to take a community off a + + align:start position:0% +you start to take a community off a + + + align:start position:0% +you start to take a community off a +district heating system, the overall + + align:start position:0% +district heating system, the overall + + + align:start position:0% +district heating system, the overall +cost profile and the efficiency of that + + align:start position:0% +cost profile and the efficiency of that + + + align:start position:0% +cost profile and the efficiency of that +district heating system become a + + align:start position:0% +district heating system become a + + + align:start position:0% +district heating system become a +problem. Um so it's it's caused negative + + align:start position:0% +problem. Um so it's it's caused negative + + + align:start position:0% +problem. Um so it's it's caused negative +tension with the district heating + + align:start position:0% +tension with the district heating + + + align:start position:0% +tension with the district heating +community. On the other hand, you've had + + align:start position:0% +community. On the other hand, you've had + + + align:start position:0% +community. On the other hand, you've had +lots of uh people who were looking at + + align:start position:0% +lots of uh people who were looking at + + + align:start position:0% +lots of uh people who were looking at +doing their own individual installation + + align:start position:0% +doing their own individual installation + + + align:start position:0% +doing their own individual installation +and then they suddenly realized well + + align:start position:0% +and then they suddenly realized well + + + align:start position:0% +and then they suddenly realized well +actually we can band together and create + + align:start position:0% +actually we can band together and create + + + align:start position:0% +actually we can band together and create +a community energy scheme. And in a + + align:start position:0% +a community energy scheme. And in a + + + align:start position:0% +a community energy scheme. And in a +country like Belgium, community energy + + align:start position:0% +country like Belgium, community energy + + + align:start position:0% +country like Belgium, community energy +is really the thing that's driving uh + + align:start position:0% +is really the thing that's driving uh + + + align:start position:0% +is really the thing that's driving uh +this push towards network geothermal. + + align:start position:0% +this push towards network geothermal. + + + align:start position:0% +this push towards network geothermal. +It's not just communities. It's, you + + align:start position:0% +It's not just communities. It's, you + + + align:start position:0% +It's not just communities. It's, you +know, property developers. It's rural + + align:start position:0% +know, property developers. It's rural + + + align:start position:0% +know, property developers. It's rural +communities. It's a variety of people + + align:start position:0% +communities. It's a variety of people + + + align:start position:0% +communities. It's a variety of people +just saying, "Look, it makes sense for + + align:start position:0% +just saying, "Look, it makes sense for + + + align:start position:0% +just saying, "Look, it makes sense for +us to work together to build a common + + align:start position:0% +us to work together to build a common + + + align:start position:0% +us to work together to build a common +infrastructure because then it's so much + + align:start position:0% +infrastructure because then it's so much + + + align:start position:0% +infrastructure because then it's so much +cheaper." And just for full disclosure, + + align:start position:0% +cheaper." And just for full disclosure, + + + align:start position:0% +cheaper." And just for full disclosure, +I'm trying to set one up in my street. I + + align:start position:0% +I'm trying to set one up in my street. I + + + align:start position:0% +I'm trying to set one up in my street. I +live opposite the school. I want the + + align:start position:0% +live opposite the school. I want the + + + align:start position:0% +live opposite the school. I want the +school to to have all the bore holes and + + align:start position:0% +school to to have all the bore holes and + + + align:start position:0% +school to to have all the bore holes and +for us to pay a small fee to connect to + + align:start position:0% +for us to pay a small fee to connect to + + + align:start position:0% +for us to pay a small fee to connect to +their system. I've got um of uh of the + + align:start position:0% +their system. I've got um of uh of the + + + align:start position:0% +their system. I've got um of uh of the +72 uh houses in my uh uh in my my two + + align:start position:0% +72 uh houses in my uh uh in my my two + + + align:start position:0% +72 uh houses in my uh uh in my my two +blocks, we've got 30. so far who were + + align:start position:0% +blocks, we've got 30. so far who were + + + align:start position:0% +blocks, we've got 30. so far who were +keen. We need to get everyone else on + + align:start position:0% +keen. We need to get everyone else on + + + align:start position:0% +keen. We need to get everyone else on +board and then we need to lobby the + + align:start position:0% +board and then we need to lobby the + + + align:start position:0% +board and then we need to lobby the +school to agree to do this one and get + + align:start position:0% +school to agree to do this one and get + + + align:start position:0% +school to agree to do this one and get +some way in which we can finance it. But + + align:start position:0% +some way in which we can finance it. But + + + align:start position:0% +some way in which we can finance it. But +you know individual installations are + + align:start position:0% +you know individual installations are + + + align:start position:0% +you know individual installations are +not the default option anymore. People + + align:start position:0% +not the default option anymore. People + + + align:start position:0% +not the default option anymore. People +want to be part of a um a collective + + align:start position:0% +want to be part of a um a collective + + + align:start position:0% +want to be part of a um a collective +system. It's part of the normalization + + align:start position:0% +system. It's part of the normalization + + + align:start position:0% +system. It's part of the normalization +of the technology as well. And then the + + align:start position:0% +of the technology as well. And then the + + + align:start position:0% +of the technology as well. And then the +third element and I'm going to spend a + + align:start position:0% +third element and I'm going to spend a + + + align:start position:0% +third element and I'm going to spend a +bit of time on this later on is the + + align:start position:0% +bit of time on this later on is the + + + align:start position:0% +bit of time on this later on is the +planning aspect because Europe has been + + align:start position:0% +planning aspect because Europe has been + + + align:start position:0% +planning aspect because Europe has been +heavily dependent upon imported gas and + + align:start position:0% +heavily dependent upon imported gas and + + + align:start position:0% +heavily dependent upon imported gas and +the crisis that happened after Ukraine + + align:start position:0% +the crisis that happened after Ukraine + + + align:start position:0% +the crisis that happened after Ukraine +was invaded. Uh the kind of response was + + align:start position:0% +was invaded. Uh the kind of response was + + + align:start position:0% +was invaded. Uh the kind of response was +saying okay well we need to make someone + + align:start position:0% +saying okay well we need to make someone + + + align:start position:0% +saying okay well we need to make someone +responsible for planning a transition. + + align:start position:0% +responsible for planning a transition. + + + align:start position:0% +responsible for planning a transition. +Um and you know whilst you'll have all + + align:start position:0% +Um and you know whilst you'll have all + + + align:start position:0% +Um and you know whilst you'll have all +the kind of campaigners saying look the + + align:start position:0% +the kind of campaigners saying look the + + + align:start position:0% +the kind of campaigners saying look the +revolution is going to be exciting. + + align:start position:0% +revolution is going to be exciting. + + + align:start position:0% +revolution is going to be exciting. +We're going to be manning the + + align:start position:0% +We're going to be manning the + + + align:start position:0% +We're going to be manning the +barricades. It's not true. The energy + + align:start position:0% +barricades. It's not true. The energy + + + align:start position:0% +barricades. It's not true. The energy +revolution is all about logistics and + + align:start position:0% +revolution is all about logistics and + + + align:start position:0% +revolution is all about logistics and +planning and finance. That's all it is. + + align:start position:0% +planning and finance. That's all it is. + + + align:start position:0% +planning and finance. That's all it is. +Um I can see Hela smiling K + + align:start position:0% +Um I can see Hela smiling K + + + align:start position:0% +Um I can see Hela smiling K +on this point, but it really is that + + align:start position:0% +on this point, but it really is that + + + align:start position:0% +on this point, but it really is that +pedantic. You need to know, you need to + + align:start position:0% +pedantic. You need to know, you need to + + + align:start position:0% +pedantic. You need to know, you need to +get out maps of streets and start + + align:start position:0% +get out maps of streets and start + + + align:start position:0% +get out maps of streets and start +working out well actually what parts can + + align:start position:0% +working out well actually what parts can + + + align:start position:0% +working out well actually what parts can +we convert quickly who goes first, who + + align:start position:0% +we convert quickly who goes first, who + + + align:start position:0% +we convert quickly who goes first, who +goes second, who goes third. But more + + align:start position:0% +goes second, who goes third. But more + + + align:start position:0% +goes second, who goes third. But more +importantly, who makes those decisions? + + align:start position:0% +importantly, who makes those decisions? + + + align:start position:0% +importantly, who makes those decisions? +So let me give you some examples to kind + + align:start position:0% +So let me give you some examples to kind + + + align:start position:0% +So let me give you some examples to kind +of illustrate this transition. and and + + align:start position:0% +of illustrate this transition. and and + + + align:start position:0% +of illustrate this transition. and and +Sanjie, I'm gonna I'm gonna briefly say + + align:start position:0% +Sanjie, I'm gonna I'm gonna briefly say + + + align:start position:0% +Sanjie, I'm gonna I'm gonna briefly say +because you're on the screen that um a + + align:start position:0% +because you're on the screen that um a + + + align:start position:0% +because you're on the screen that um a +couple minutes for the examples would be + + align:start position:0% +couple minutes for the examples would be + + + align:start position:0% +couple minutes for the examples would be +wonderful. Thank you. + + align:start position:0% +wonderful. Thank you. + + + align:start position:0% +wonderful. Thank you. +>> Yeah. Yeah. No, no, I I'm gonna race + + align:start position:0% +>> Yeah. Yeah. No, no, I I'm gonna race + + + align:start position:0% +>> Yeah. Yeah. No, no, I I'm gonna race +through these ones. In fact, I'll just + + align:start position:0% +through these ones. In fact, I'll just + + + align:start position:0% +through these ones. In fact, I'll just +give you one example here. Enfield + + align:start position:0% +give you one example here. Enfield + + + align:start position:0% +give you one example here. Enfield +Council, this is a local authority. They + + align:start position:0% +Council, this is a local authority. They + + + align:start position:0% +Council, this is a local authority. They +converted to geothermal not because they + + align:start position:0% +converted to geothermal not because they + + + align:start position:0% +converted to geothermal not because they +loved their network geothermal, but + + align:start position:0% +loved their network geothermal, but + + + align:start position:0% +loved their network geothermal, but +because their uh the people who were + + align:start position:0% +because their uh the people who were + + + align:start position:0% +because their uh the people who were +living in the four tower blocks, you can + + align:start position:0% +living in the four tower blocks, you can + + + align:start position:0% +living in the four tower blocks, you can +see two of them behind you. they were + + align:start position:0% +see two of them behind you. they were + + + align:start position:0% +see two of them behind you. they were +massively massively indebted in terms of + + align:start position:0% +massively massively indebted in terms of + + + align:start position:0% +massively massively indebted in terms of +their energy costs. So they had a social + + align:start position:0% +their energy costs. So they had a social + + + align:start position:0% +their energy costs. So they had a social +political crisis. Um they looked at all + + align:start position:0% +political crisis. Um they looked at all + + + align:start position:0% +political crisis. Um they looked at all +sorts of options and opted for network + + align:start position:0% +sorts of options and opted for network + + + align:start position:0% +sorts of options and opted for network +geothermal. Instead of refurbishing one + + align:start position:0% +geothermal. Instead of refurbishing one + + + align:start position:0% +geothermal. Instead of refurbishing one +building and one building block by by + + align:start position:0% +building and one building block by by + + + align:start position:0% +building and one building block by by +block, what they decided to do was all + + align:start position:0% +block, what they decided to do was all + + + align:start position:0% +block, what they decided to do was all +four of them in one go. And then you got + + align:start position:0% +four of them in one go. And then you got + + + align:start position:0% +four of them in one go. And then you got +the real system efficiencies kicking + + align:start position:0% +the real system efficiencies kicking + + + align:start position:0% +the real system efficiencies kicking +through. And you can see the savings, + + align:start position:0% +through. And you can see the savings, + + + align:start position:0% +through. And you can see the savings, +you know, between 450 to 700 pounds per + + align:start position:0% +you know, between 450 to 700 pounds per + + + align:start position:0% +you know, between 450 to 700 pounds per +year uh depending on the residents. to + + align:start position:0% +year uh depending on the residents. to + + + align:start position:0% +year uh depending on the residents. to +the energy consumption within those + + align:start position:0% +the energy consumption within those + + + align:start position:0% +the energy consumption within those +buildings. This is my favorite project + + align:start position:0% +buildings. This is my favorite project + + + align:start position:0% +buildings. This is my favorite project +simply because this is in the heart of + + align:start position:0% +simply because this is in the heart of + + + align:start position:0% +simply because this is in the heart of +Brussels and it proves that where you + + align:start position:0% +Brussels and it proves that where you + + + align:start position:0% +Brussels and it proves that where you +have listed buildings, you can actually + + align:start position:0% +have listed buildings, you can actually + + + align:start position:0% +have listed buildings, you can actually +do geothermal projects and that's part + + align:start position:0% +do geothermal projects and that's part + + + align:start position:0% +do geothermal projects and that's part +of the sexy thing about it and that's + + align:start position:0% +of the sexy thing about it and that's + + + align:start position:0% +of the sexy thing about it and that's +really where network geothermal has + + align:start position:0% +really where network geothermal has + + + align:start position:0% +really where network geothermal has +kicked off in Brussels. Our SPA hospital + + align:start position:0% +kicked off in Brussels. Our SPA hospital + + + align:start position:0% +kicked off in Brussels. Our SPA hospital +is a 16th century uh site. You cannot + + align:start position:0% +is a 16th century uh site. You cannot + + + align:start position:0% +is a 16th century uh site. You cannot +touch this building place at all. + + align:start position:0% +touch this building place at all. + + + align:start position:0% +touch this building place at all. +There's a huge complex of uh uh schools. + + align:start position:0% +There's a huge complex of uh uh schools. + + + align:start position:0% +There's a huge complex of uh uh schools. +It's a UNUSCO heritage site. geothermal + + align:start position:0% +It's a UNUSCO heritage site. geothermal + + + align:start position:0% +It's a UNUSCO heritage site. geothermal +was the only option and rather than + + align:start position:0% +was the only option and rather than + + + align:start position:0% +was the only option and rather than +doing individual ground source heat + + align:start position:0% +doing individual ground source heat + + + align:start position:0% +doing individual ground source heat +pumps creating the heat network was + + align:start position:0% +pumps creating the heat network was + + + align:start position:0% +pumps creating the heat network was +really where you got the system + + align:start position:0% +really where you got the system + + + align:start position:0% +really where you got the system +efficiencies coming through the biggest + + align:start position:0% +efficiencies coming through the biggest + + + align:start position:0% +efficiencies coming through the biggest +project in Spain this is really what I + + align:start position:0% +project in Spain this is really what I + + + align:start position:0% +project in Spain this is really what I +want to talk to you about couple of + + align:start position:0% +want to talk to you about couple of + + + align:start position:0% +want to talk to you about couple of +things policy matters now um what's + + align:start position:0% +things policy matters now um what's + + + align:start position:0% +things policy matters now um what's +absolutely essential is that even if + + align:start position:0% +absolutely essential is that even if + + + align:start position:0% +absolutely essential is that even if +geothermal isn't mentioned in the first + + align:start position:0% +geothermal isn't mentioned in the first + + + align:start position:0% +geothermal isn't mentioned in the first +round of policy once you start to get + + align:start position:0% +round of policy once you start to get + + + align:start position:0% +round of policy once you start to get +people thinking about what zero looks + + align:start position:0% +people thinking about what zero looks + + + align:start position:0% +people thinking about what zero looks +like what a fully renewable system uh uh + + align:start position:0% +like what a fully renewable system uh uh + + + align:start position:0% +like what a fully renewable system uh uh +uh uh could be they'll almost always + + align:start position:0% +uh uh could be they'll almost always + + + align:start position:0% +uh uh could be they'll almost always +come and discover geothermal and then + + align:start position:0% +come and discover geothermal and then + + + align:start position:0% +come and discover geothermal and then +they'll start complaining by saying why + + align:start position:0% +they'll start complaining by saying why + + + align:start position:0% +they'll start complaining by saying why +didn't you tell us this existed before + + align:start position:0% +didn't you tell us this existed before + + + align:start position:0% +didn't you tell us this existed before +and what happened in Wunia which is a + + align:start position:0% +and what happened in Wunia which is a + + + align:start position:0% +and what happened in Wunia which is a +small part of Belgium um is they + + align:start position:0% +small part of Belgium um is they + + + align:start position:0% +small part of Belgium um is they +invested just put 35 million euros up + + align:start position:0% +invested just put 35 million euros up + + + align:start position:0% +invested just put 35 million euros up +front for some very basic grants they + + align:start position:0% +front for some very basic grants they + + + align:start position:0% +front for some very basic grants they +did a lot of iconic projects but more + + align:start position:0% +did a lot of iconic projects but more + + + align:start position:0% +did a lot of iconic projects but more +importantly you had Carlo the energy + + align:start position:0% +importantly you had Carlo the energy + + + align:start position:0% +importantly you had Carlo the energy +company all of a sudden become a + + align:start position:0% +company all of a sudden become a + + + align:start position:0% +company all of a sudden become a +national champion in network geothermal + + align:start position:0% +national champion in network geothermal + + + align:start position:0% +national champion in network geothermal +and Resiolia who were the engineering + + align:start position:0% +and Resiolia who were the engineering + + + align:start position:0% +and Resiolia who were the engineering +design company are now winning contracts + + align:start position:0% +design company are now winning contracts + + + align:start position:0% +design company are now winning contracts +all across Europe so there's an + + align:start position:0% +all across Europe so there's an + + + align:start position:0% +all across Europe so there's an +industrial policy story more than just + + align:start position:0% +industrial policy story more than just + + + align:start position:0% +industrial policy story more than just +the energy savings but what I said + + align:start position:0% +the energy savings but what I said + + + align:start position:0% +the energy savings but what I said +earlier the planning bit is absolutely + + align:start position:0% +earlier the planning bit is absolutely + + + align:start position:0% +earlier the planning bit is absolutely +essential and the two key things in the + + align:start position:0% +essential and the two key things in the + + + align:start position:0% +essential and the two key things in the +planning bit is to make sure that + + align:start position:0% +planning bit is to make sure that + + + align:start position:0% +planning bit is to make sure that +whenever you're conducting a plan it has + + align:start position:0% +whenever you're conducting a plan it has + + + align:start position:0% +whenever you're conducting a plan it has +to be based on local renewable energy + + align:start position:0% +to be based on local renewable energy + + + align:start position:0% +to be based on local renewable energy +supplies if you take those two words out + + align:start position:0% +supplies if you take those two words out + + + align:start position:0% +supplies if you take those two words out +of it you will end up with you know + + align:start position:0% +of it you will end up with you know + + + align:start position:0% +of it you will end up with you know +biomass you'll end up with a variety of + + align:start position:0% +biomass you'll end up with a variety of + + + align:start position:0% +biomass you'll end up with a variety of +you know Frankenstein solutions if you + + align:start position:0% +you know Frankenstein solutions if you + + + align:start position:0% +you know Frankenstein solutions if you +want to keep it towards geothermal + + align:start position:0% +want to keep it towards geothermal + + + align:start position:0% +want to keep it towards geothermal +you've got to focus on the locality and + + align:start position:0% +you've got to focus on the locality and + + + align:start position:0% +you've got to focus on the locality and +the renewable aspect around it But + + align:start position:0% +the renewable aspect around it But + + + align:start position:0% +the renewable aspect around it But +really what's super pertinent around + + align:start position:0% +really what's super pertinent around + + + align:start position:0% +really what's super pertinent around +this is the the fact that words matter. + + align:start position:0% +this is the the fact that words matter. + + + align:start position:0% +this is the the fact that words matter. +So when we describe uh network + + align:start position:0% +So when we describe uh network + + + align:start position:0% +So when we describe uh network +geothermal, the reason why we'd say + + align:start position:0% +geothermal, the reason why we'd say + + + align:start position:0% +geothermal, the reason why we'd say +network geothermal and not fifth + + align:start position:0% +network geothermal and not fifth + + + align:start position:0% +network geothermal and not fifth +generation district heating or network + + align:start position:0% +generation district heating or network + + + align:start position:0% +generation district heating or network +uh uh uh sorry heat pump networks is + + align:start position:0% +uh uh uh sorry heat pump networks is + + + align:start position:0% +uh uh uh sorry heat pump networks is +that they don't have the word geothermal + + align:start position:0% +that they don't have the word geothermal + + + align:start position:0% +that they don't have the word geothermal +in. And if you don't have the word + + align:start position:0% +in. And if you don't have the word + + + align:start position:0% +in. And if you don't have the word +geothermal, you're going to miss all of + + align:start position:0% +geothermal, you're going to miss all of + + + align:start position:0% +geothermal, you're going to miss all of +the things that you need to go through + + align:start position:0% +the things that you need to go through + + + align:start position:0% +the things that you need to go through +to get to the network geothermal system. + + align:start position:0% +to get to the network geothermal system. + + + align:start position:0% +to get to the network geothermal system. +Always focus on who makes the + + align:start position:0% +Always focus on who makes the + + + align:start position:0% +Always focus on who makes the +investment. So in the some of the + + align:start position:0% +investment. So in the some of the + + + align:start position:0% +investment. So in the some of the +examples I've showed you, it's the local + + align:start position:0% +examples I've showed you, it's the local + + + align:start position:0% +examples I've showed you, it's the local +government, it's a community, it's a + + align:start position:0% +government, it's a community, it's a + + + align:start position:0% +government, it's a community, it's a +property developer, their needs are + + align:start position:0% +property developer, their needs are + + + align:start position:0% +property developer, their needs are +completely different, but the way in + + align:start position:0% +completely different, but the way in + + + align:start position:0% +completely different, but the way in +which they access finance is also + + align:start position:0% +which they access finance is also + + + align:start position:0% +which they access finance is also +completely different. So it changes the + + align:start position:0% +completely different. So it changes the + + + align:start position:0% +completely different. So it changes the +gambit. Um business models are the most + + align:start position:0% +gambit. Um business models are the most + + + align:start position:0% +gambit. Um business models are the most +important thing. It's not about can you + + align:start position:0% +important thing. It's not about can you + + + align:start position:0% +important thing. It's not about can you +do the project, it's about how do you + + align:start position:0% +do the project, it's about how do you + + + align:start position:0% +do the project, it's about how do you +make it profitable for everybody and + + align:start position:0% +make it profitable for everybody and + + + align:start position:0% +make it profitable for everybody and +that's where the innovation around you + + align:start position:0% +that's where the innovation around you + + + align:start position:0% +that's where the innovation around you +know whether you have an onbalance or + + align:start position:0% +know whether you have an onbalance or + + + align:start position:0% +know whether you have an onbalance or +offbalance sheet. um what's the size and + + align:start position:0% +offbalance sheet. um what's the size and + + + align:start position:0% +offbalance sheet. um what's the size and +the length of the project? How do you + + align:start position:0% +the length of the project? How do you + + + align:start position:0% +the length of the project? How do you +build in the modules? How do you kind of + + align:start position:0% +build in the modules? How do you kind of + + + align:start position:0% +build in the modules? How do you kind of +seg uh disagregate the different prices + + align:start position:0% +seg uh disagregate the different prices + + + align:start position:0% +seg uh disagregate the different prices +that people pay? This is the most + + align:start position:0% +that people pay? This is the most + + + align:start position:0% +that people pay? This is the most +important thing when it comes to + + align:start position:0% +important thing when it comes to + + + align:start position:0% +important thing when it comes to +designing a system at scale. + + align:start position:0% +designing a system at scale. + + + align:start position:0% +designing a system at scale. +Uh super important drilling is sexy. So + + align:start position:0% +Uh super important drilling is sexy. So + + + align:start position:0% +Uh super important drilling is sexy. So +whilst everyone talks about the energy + + align:start position:0% +whilst everyone talks about the energy + + + align:start position:0% +whilst everyone talks about the energy +savings, the greenhouse gas emission + + align:start position:0% +savings, the greenhouse gas emission + + + align:start position:0% +savings, the greenhouse gas emission +reductions, that's great, but in the + + align:start position:0% +reductions, that's great, but in the + + + align:start position:0% +reductions, that's great, but in the +geothermal world, once you've done an + + align:start position:0% +geothermal world, once you've done an + + + align:start position:0% +geothermal world, once you've done an +installation, you will not see + + align:start position:0% +installation, you will not see + + + align:start position:0% +installation, you will not see +geothermal ever again. apart from two + + align:start position:0% +geothermal ever again. apart from two + + + align:start position:0% +geothermal ever again. apart from two +black pipes coming out into a into your + + align:start position:0% +black pipes coming out into a into your + + + align:start position:0% +black pipes coming out into a into your +heat pump. + + align:start position:0% +heat pump. + + + align:start position:0% +heat pump. +>> So, the drilling bit is where you get + + align:start position:0% +>> So, the drilling bit is where you get + + + align:start position:0% +>> So, the drilling bit is where you get +people attracted. + + align:start position:0% +people attracted. + + + align:start position:0% +people attracted. +>> Two more things, super important. You've + + align:start position:0% +>> Two more things, super important. You've + + + align:start position:0% +>> Two more things, super important. You've +got to have more and more people + + align:start position:0% +got to have more and more people + + + align:start position:0% +got to have more and more people +providing the service of uh designing + + align:start position:0% +providing the service of uh designing + + + align:start position:0% +providing the service of uh designing +and install installation. The more you + + align:start position:0% +and install installation. The more you + + + align:start position:0% +and install installation. The more you +do that, the more competitive the price + + align:start position:0% +do that, the more competitive the price + + + align:start position:0% +do that, the more competitive the price +becomes, the more you start to get + + align:start position:0% +becomes, the more you start to get + + + align:start position:0% +becomes, the more you start to get +suppliers chasing markets. And this is + + align:start position:0% +suppliers chasing markets. And this is + + + align:start position:0% +suppliers chasing markets. And this is +really the space we want to get to. And + + align:start position:0% +really the space we want to get to. And + + + align:start position:0% +really the space we want to get to. And +then the final thing is is that whilst + + align:start position:0% +then the final thing is is that whilst + + + align:start position:0% +then the final thing is is that whilst +we talk about the energy service + + align:start position:0% +we talk about the energy service + + + align:start position:0% +we talk about the energy service +delivery, the real political win is an + + align:start position:0% +delivery, the real political win is an + + + align:start position:0% +delivery, the real political win is an +industrial policy. Can you set up + + align:start position:0% +industrial policy. Can you set up + + + align:start position:0% +industrial policy. Can you set up +manufacturing uh uh any part of the + + align:start position:0% +manufacturing uh uh any part of the + + + align:start position:0% +manufacturing uh uh any part of the +component features? Can you create + + align:start position:0% +component features? Can you create + + + align:start position:0% +component features? Can you create +companies with design experts or + + align:start position:0% +companies with design experts or + + + align:start position:0% +companies with design experts or +training experts or drilling experts? + + align:start position:0% +training experts or drilling experts? + + + align:start position:0% +training experts or drilling experts? +That's where you get the real value for + + align:start position:0% +That's where you get the real value for + + + align:start position:0% +That's where you get the real value for +money. That's where the competitions + + align:start position:0% +money. That's where the competitions + + + align:start position:0% +money. That's where the competitions +really start to wake up. So on that + + align:start position:0% +really start to wake up. So on that + + + align:start position:0% +really start to wake up. So on that +note, think global, + + align:start position:0% +note, think global, + + + align:start position:0% +note, think global, +think global, go. + + align:start position:0% +think global, go. + + + align:start position:0% +think global, go. +[Laughter] + + align:start position:0% +[Laughter] + + + align:start position:0% +[Laughter] +>> Thank you. Thank you, Sanjief. And I I I + + align:start position:0% +>> Thank you. Thank you, Sanjief. And I I I + + + align:start position:0% +>> Thank you. Thank you, Sanjief. And I I I +see that you uh your previous slide you + + align:start position:0% +see that you uh your previous slide you + + + align:start position:0% +see that you uh your previous slide you +apparently agree with our + + align:start position:0% +apparently agree with our + + + align:start position:0% +apparently agree with our +administration's drill baby drill. Um + + align:start position:0% +administration's drill baby drill. Um + + + align:start position:0% +administration's drill baby drill. Um +so thank you for covering so much. \ No newline at end of file diff --git a/j1H3jAAGlEA.txt b/j1H3jAAGlEA.txt new file mode 100644 index 0000000000000000000000000000000000000000..f306fb56aa86957d7334b2f203a06ddda2a898db --- /dev/null +++ b/j1H3jAAGlEA.txt @@ -0,0 +1,2282 @@ +PATRICK WINSTON: Today +we're going to be + +talking about Search. + +I know you're going to +turn blue with yet + +another lecture on Search. + +Those of you who are taking +computer science subjects, + +you've probably seen in 601. + +You'll see it again +as theory course. + +But we're going to do it for +a little different purpose. + +I want you to develop some +intuition about various kinds + +of Search work. + +And I want to talk a little bit +about Search as a model of + +what goes on in our heads. + +And toward the end, if there's +time, I'd like to do a + +demonstration for you of +something never before + +demonstrated to a 603.4 class, +because it was only completed + +last spring. + +And some finishing touches were +added by me this morning. + +Always dangerous, but we'll +see what happens. + +There's Cambridge. + +You all recognize +it, of course. + +You might want to get from some +starting position s to + +some goal position g. + +So, you'll hire a cab and +hope for the best. + +So, here's what might +happen, not too hot. + +Let's move the starting +position over here. + +I've had cab drivers +like this New York. + +But it's not a very good path. + +It's the path of a thief. + +Let's change the way that the +search is done to that of a + +beginner, an honest beginner. + +Not too bad. + +Now, let's have a look at how +the Search would happen if the + +cab driver was a Ph.D. +in physics + +after his third post-doc. + +These are not actually +traverse. + +These are just things that the +driver is thinking about, and + +that is the very best of +all possible paths. + +So, the thief does +a horrible job. + +The beginner does a pretty +good job, but + +not an optimal job. + +This is the optimal job as +produced by the Ph.D. in + +physics after his +third post-doc. + +So, would you like to understand +how those all work? + +The answer, of course, is yes. + +I'm going to talk to you about +procedures that are different + +from the way that you just +solved this problem. + +I imagine that if I said to you, +please find a path for s + +to g, you would, within +a few seconds, find + +a pretty good path-- + +not the optimal one, but +a pretty good one-- + +using your eyes. + +And we're not going to tell +you about how that works, + +because we don't know +how that works. + +But we do know that problem +solving with the eyes is an + +important part of our +total intelligence. + +And we'll never have a complete +theory of human + +intelligence until we can +understand the contributions + +of the human visual system to +solving everyday problems like + +finding a pretty good +path in that map. + +But, alas, we can't talk about +that, because we don't know + +how to do it. + +We're working on it. + +But we don't know +how to do it. + +So, I'm not going to use +Cambridge in my illustrations. + +There's too much there to +work through in an hour. + +So, we're going to use this map +over here which has been + +designed to illustrate a +few important points. + +You, too, can find a path +through that graph pretty + +easily with your eyes. + +Our programs don't have eyes, +and they don't have visually + +grounded algorithms, so they're +going to have to do + +something else. + +And the very first kind of +search we want to talk about + +is called the British +Museum approach. + +This is a slur against at least +the British Museum, if + +not the entire nation, because +the way you do a British + +Museum search is you find +every possible path. + +So, it'll be helpful to have a +diagram of all possible paths + +on the board. + +We're going to start with +a British Museum search. + +From the starting position, it's +clear, you can go from my + +s to either a or b. + +And already there's an +important quiz point. + +Whenever we have these kinds of +problems on a quiz, we ask + +you to develop the tree +associated with a search in + +lexical order. + +So, the nodes there under s +are listed alphabetically, + +just to have an orderly +way of doing it. + +So, from a we can go +either b or d. + +And another convention of the +subject, another thing you + +have to keep in mind in quizzes, +is it we don't have + +these searches bite +their own tail. + +So, I could have said that +if I'm at a, I can + +also go back to s. + +But no path is ever allowed +them to bite itself, to go + +around and enter and get +back to a place that's + +already on the path. + +Now if I go on to b first, that +means that from b I can + +go to either a or c. + +This is getting fat +pretty fast. + +But let's see, s, a, b. + +The only place I can go +is c and then to e. + +s, a, d, without biting my own +tail and going back to a, the + +only place I can go is g. + +s b, a, I can only go +to d and then to g. + +And finally, s, b, c, +I can only go to e. + +So, that is a complete set of +paths as produced by any + +program that you will feel you'd +like to write that finds + +all possible paths. + +I haven't been very precise +about how to do that, because + +you don't have to be. + +You can't save much work by +being clever, because you have + +to find everything. + +So, that's the British Museum +expansion of the tree. + +So, what have I done? + +I've been playing around +with a map. + +I showed you an example +of a map. + +And pretty soon you're +going to think that + +Search is about maps. + +So, before going even another +tiny step, I want to emphasize + +that Search is not +equal to maps. + +Search is about choice. + +And I happen to illustrate +these searches with maps, + +because they are particularly +cogent. + +But Search is not about maps. + +It's about the choices you make +when you're trying to + +make decisions. + +These things I'm going to be +talking to you about today are + +choices you make when +you explore the map. + +You can make other kinds of +choices when you're exploring + +other kinds of things. + +And, in fact, at the end, if +there's time, I'll show you + +how you do searches when you're +solving problems in a + +humanities class. + +That's the British +Museum algorithm. + +Search is not about maps. + +Our first gold star idea, +Search is about choice. + +But for our illustration, +Search is about maps. + +So, the first kind of Search we +want to talk about that's + +real is Depth-first Search. + +And the idea of Depth-first +Search is that you barrel + +ahead in a single-minded way. + +So, from s, your choices +are a or b. + +And you always go down the left +branch by convention. + +So, from s, we go to a. + +From a we have two choices. + +We can go to either b or +d following our lexical + +convention. + +After that, we can go to c. + +And after that we can go to e. + +And too bad for us, +we're stuck. + +What are we going to do. + +We've got into a dead +end, all is lost. + +But of course, all isn't lost. + +Because we have the choice of +backing up to the place where + +we last made a decision and +choosing another branch. + +So, that process is called +variously back-up or + +backtracking. + +At this point, we would +say, ah, dead end. + +The first place we find when we +back up the tree where we + +made a choice is when we +chose b instead of d. + +So, we go back up there and +take the other route. + +s, a, d now goes to g. + +And we're done. + +We're going to make up a little +table here of things + +that we can embellish our +basic searches with. + +And one of the things we can +embellish our basic searches + +with is this backtracking +idea. + +Now, backtrack is not relevant +to the British Museum + +algorithm, because you've +got to find everything. + +You can't quit when you've +found one path. + +But you'd always want to use +backtracking with Depth-first + +Search, because you may plunge +on down and miss the path that + +gets to the goal. + +Now, you might ask me, is +backtracking, therefore, + +always part of Depth-first +Search? + +And you can read textbooks +that do it either way. + +Count on it. + +If we give you a Search problem +on a quiz, we'll tell + +you whether or not your Search +is supposed to use + +backtracking. + +We consider it to be +an optional thing. + +You'd be pretty stupid not to +use this optional thing when + +you're doing Depth-first +Search. + +But we'll separate these +ideas out and call + +it an optional add-on. + +so, that's Depth-first +Search, very simple. + +Now, the natural companion to +Depth-first Search will be + +Breadth-first Search, +Breadth-first. + +And the way it works is you +build up this tree level by + +level, and at some point, when +you scan across a level, + +you'll find that you've +completed a path + +that goes to the goal. + +So, level by level, s can +go to either a or b. + +a can go either to b or d. + +And b can go to either a or c. + +So, you see what we're doing. + +We're going level by level. + +And we haven't hit a level +with a goal in it yet, so + +we've got to keep going. + +Note that we're building up +quite a bit of stuff here, + +quite a lot of growth in the +size of the path set that + +we're keeping in mind. + +At the next level, we have b +going to c, d going to g, a + +going to d, and c going to e. + +And now, when we scan +across, we do hit g. + +So, we found a path with +Breadth-first Search, just as + +we found a path with +Depth-first Search. + +Now, you might say, well, +why didn't you just quit + +when you hit g? + +Implementation detail. + +We'll talk about a sample +implementation. + +You can write it in +any way you want. + +But now that we know what these +searches are, let's + +speed things up a little bit +here and do a couple searches + +that now have names. + +The first type will be +Depth-first, boom. + +That's the one that produces +the thief path. + +And then we can also do a +Breadth-first Search, which we + +haven't tried yet. + +What do you suppose is +going to happen? + +Is it going to be fast, slow, +produce a good path, + +produce a bad path? + +I don't know, let's try it. + +I had to speed it up, you see, +because it's doing an awful + +lot of Search. + +It's generating an awful +lot of paths. + +Finally, you got a path. + +Is it the best path? + +I don't think so. + +But we're not going to talk +about optimal paths today. + +We're just going to talk +about pretty good + +paths, heuristic paths. + +Let's move the starting position +here in the middle. + +Do you think Breadth-first +Search is going to be stupid? + +I think it's going to +be pretty stupid. + +Let's see what happens. + +This Search is a lot to the +left, which you would never do + +with you eye. + +Let me slow that down just +to demonstrate it. + +It finds a shorter path, because +it's right there in + +the middle. + +But it spends a lot of its time +looking off to the left. + +It's pretty stupid. + +But that's how it works. + +So, now that we've got two +examples of searches on the + +table, I'd like to just write +a little flow chart for how + +the search might work. + +Because if I do that, then it'll +be easier for us to see + +what kind of small differences +there are between the + +implementations of these +various searches. + +So, what we're going to do is +we're going to develop a + +waiting list, a queue, a +line, whatever you'd + +like to call it. + +Let's call if a queue. + +We're going to develop a queue +of paths that are under + +consideration. + +So, the first step in our +algorithm will be to + +initialize our queue. + +And I think what I'll do is +I'll simulate Depth-first + +Search on this problem +up there on the + +left using this algorithm. + +I need to have some way of +representing my paths. + +And what I want to do is I'm +going to betray my heritage as + +a list programmer, because I'm +just going to put these up as + +if there were lisp +s-expressions. + +To begin with, I just +have one path. + +And it has only one +node in it, s. + +That's the whole path. + +The next thing I do after I +initialize the queue is I + +extend first path +on the queue. + +OK, when I extend s, +I get two paths. + +I get s goes to a, and +I get s goes to b. + +I take the first one off +the front of the queue. + +And I put back the two +that are produced by + +extending that path. + +Now, after I've extended the +first path on the queue, I + +have to but those extended +paths on to the queue. + +In here there's an explicit step +where I've checked to see + +if that first path +is a winner. + +If it's not, I extend it. + +And I have to put those +paths onto the queue. + +So, I'll say that what +I do is I end queue. + +Now, I've done one step. + +And let's let me do +another step. + +I'm going to take this +first path off. + +I'm going to extend that path. + +And where do I put these new +paths on the queue if I'm + +doing Depth-first Search? + +Well, I want to work with the +path that I've just generated. + +I'm taking this plunge down +deep into the search tree. + +So, since I want to keep going +down into the stuff that I + +just generated, where then do I +want to put these two paths? + +At the end of the queue? + +I don't think so, because +it'll be a long + +time getting there. + +I want to put them on the +front of the queue. + +For Depth-first Search, I +want to put them on the + +front of the queue. + +And that's why s, a, b goes +here, and s, a, d, and then + +that's s, b. + +So, s, b is still there. + +That's still a valid +possibility. + +But now I've stuck two paths +in front of it, both of the + +ones I generated by taking a +path off the front of the + +queue, discovering that it +doesn't go to the goal, + +extending it and putting those +back on the queue. + +I might as well complete +this illustration here. + +While I'm at it, I take the s, +a, b off, s, a, b, and I can + +go only there to c. + +But, of course, I keep s, a, +d and s, b on the queue. + +Now, I take the front off the +queue again, and I get s, a, + +b, c, e, and not to forget +s, a, d and s, b. + +I take the first one +off the queue. + +It doesn't go to the goal. + +I try to extend it, but +there's nothing there. + +I've reached a dead end. + +So, in this operation, all I'm +doing is taking the front one + +off the queue and shortening +the queue. + +We're almost home. + +I take s, a,d off of queue. + +And I get s, a, d, c. + +And, of course, I +still have s, b. + +Now, the next time I visit the +situation, buried in that + +first step, I discover a path +that actually does get to + +goal, and I'm done. + +So, each time around I +visualize the queue. + +I check to see if I'm done. + +If not, I take the extensions +and put them + +somewhere on the queue. + +And then I go back in. + +And then here there's a varied +test which checks to see if + +we're done. + +That's how the Depth-first +Search algorithm works. + +And now, would we have to start +all over again if we did + +Breadth-first Search? + +Nope. + +Same algorithm. + +All the code we've got +needs one line + +replaced, one line changed. + +What do I have to do different +in order to get a + +Breadth-first Search out +of this instead of + +a Depth-first Search? + +Tanya? + +TANYA: Change [INAUDIBLE] +on the queue. + +PATRICK WINSTON: And where +do I put it on the queue? + +She says to change it. + +TANYA: On the back? + +PATRICK WINSTON: Put +it on the back. + +So, with Breadth-first Search +all I have to do + +is put on the back. + +Now, if we were content with a +inefficient search, and didn't + +care much about how good our +path was, we'd be done. + +And we could go home. + +But we are a little concerned +about the + +efficiency of our search. + +And we would like a +pretty good path. + +So, we're going to have +to stick around + +for a little while. + +Now, you may have noticed, up +there in that the development + +of the Breadth-first Search, +that the algorithm is + +incredibly stupid. + +Why is the algorithm +incredibly stupid? + +Ty, what do you think? + +TY: It can't tell whether it's +getting closer or further away + +from the goal. + +PATRICK WINSTON: It certainly +can't tell whether it's + +getting closer or further +away from the goal. + +And we're going to deal +with that in a minute. + +But it's even stupider +than that. + +Why is it stupid? + +What's your name? + +DYLAN: Dylan. + +It [? hits ?] the same +nodes twice. + +PATRICK WINSTON: Dylan said it's +extending paths that go + +to the same node +more than once. + +Let's see what Dylan's +talking about. + +Down here, it extends a. + +But it's already extended +a up there. + +Down here, it extends a +path that goes to b. + +And it's already extended +a path that goes to d. + +Over here, it could extend a +path that went through c, but + +it's already got a path +that goes through c. + +So, all of these paths +are duplicated. + +And we're still going +through them. + +That's incredibly stupid. + +What we're going to do is +we're going to amend our + +algorithm just a little bit. + +And we're not going to extend +the first path on the queue + +unless final node never +before extended. + +What we're going to do is we're +going to look to see if + +there-- we've got this path. + +And we're going to extend it. + +And it's got a final note. + +If we've ever extended a path +that goes to that final node, + +and it was a final node on +that path, then we're not + +going to do it again. + +We got to keep a list of places +that have already been + +the last piece of a path +that was extended. + +Everybody got that? + +It's a little awkward to say it, +because it's the last node + +we care about. + +If a path terminates in a node, +and if some other path + +previously terminated in that +node and got extended-- + +we're not going to +do it again. + +Because it's a waste of time. + +Now, let's see if this +actually helps. + +Now, use the extended list. + +Let's see, well, gee, +we got that place + +in the center there. + +Let's just repeat the +previous search. + +Wow, it's taking a long time. + +But notice it put 103 paths +back on the queue. + +Now, let's add a filter +and try again. + +A lot less. + +So, let's speed this up, and +we'll start way over here. + +You remember how tedious +that search was. + +And now we'll repeat it with +this list, boom, there it is. + +That's all because we didn't do +that silly thing of going + +back through the final +node that's + +already been gone through. + +So, you would never not +want to do this. + +We better list this +as another option. + +It doesn't help with a British +Museum algorithm, because + +nothing helps with the British +Museum algorithm. + +Does it help with Depth-first? + +Yes. + +Does it help with +Breadth-first? + +Yes. + +Do we do backtracking +with Breadth-first? + +No, because backtracking +can't do us any good. + +OK, we're almost, except that +search that's starting in the + +middle is still pretty stupid. + +Both the Breadth-first version +and the Depth-first version + +are going off to the left. + +And we would never do that with +our eyes in any case. + +The next thing we want to do is +we want to have ourselves a + +slightly more informed search +by taking into consideration + +whether we seem to be +getting anywhere. + +So, in general, it's a good +thing to get closer to where + +we want to go. + +In general, if we've got a +choice of going to a node + +that's close to the goal or a +node that's not so close to + +the goal, we'll always want +to go to the one that's + +close to the goal. + +And as soon as we add that to +what we're doing, we have + +another kind of Search, +which goes by the + +name of Hill Climbing. + +And it's just like Depth-first +Search, except instead of + +using lexical order to break +ties, we're going to break + +ties according to which node +is closer to the goal. + +I went to some trouble +to talk to you about + +this enqueued list. + +And having gone to that +trouble, I'm now + +going to ignore it. + +Not because it isn't a good +idea, but because trying to + +keep track of everything +in the example is + +confusing the example. + +It won't work out right in the +small example and all that. + +Put the queueing thing aside, +queued list aside, and think + +instead just about the value +of going in the direction + +that's getting us closer +to the goal. + +In Hill Climbing Search, just +like a Depth-first Search, we + +have a and b. + +And we're still going to list +them lexically on underneath + +the parent node. + +But now which one is so +closer to the goal? + +Now, this time b is closer +to the goal than a. + +So, instead of following the +Depth-first course, which + +would take us down through a, +we're going to go to the one + +that's closest which +goes through b. + +And b can either go to a or c. + +b is six units away from the +goal. a is about seven plus, + +not drawn exactly to scale. + +Use the numbers not your eyes. + +Now where are we? + +It's symmetric, so a and +c are both equally + +far from the goal. + +Now we're going to use +the lexical order + +to break the tie. + +Now from s, b, a, +we'll go to d. + +And now, which is closest +to the goal? + +That's the only choice +we have. + +So, now we have no choice but +to go down to the goal. + +That's the Hill Climbing way +of doing the search. + +And notice that this time +there's no backtracking. + +It's not the optimal path. + +It's not the best path. + +But at least there's +no backtracking. + +That's not always true. + +That's just an artifact of +this particular example. + +Do you think Hill Climbing would +produce a faster search? + +I think so. + +Let's see what happens +when we add these + +things at one at a time. + +First, let's turn off +our extended list. + +We turned off our +extended list. + +And we're going to do +Depth-first again just for the + +sake of comparison. + +It produces a very roundabout +path with 48 enqueueings. + +Now, let's switch over +to Hill Climbing. + +And what do think? + +Do you think it will produce +a straighter path, fewer + +enqueueings? + +Boom. + +You wouldn't not want to +do that, would you? + +If you've got some kind of +heuristic that tells you that + +you're getting close to the +goal, you should use it. + +Now, it's easy to modify my +example over there so that + +getting close to the goal +gets you trapped in a + +blind alley on e. + +That's easy to do. + +But that's just an artifact +of the example. + +In general, you want to go along +a path that gets you + +closer to the goal. + +So, that's 23. + +I don't know, let's see if using +the extended list filter + +does any good. + +Yeah, still 23. + +So, in that particular case +the extension list didn't + +actually do us any good, because +we're driving so + +directly toward the goal. + +OK, that's that. + +Now, let's see, is there +any analog to-- + +well, we might say that this +is yet another way of + +distinguishing the searches. + +And that is, is it an +informed search? + +Is it making use of any kind +of heuristic information? + +Certainly, a British Museum +is not, Depth is + +not, Breadth is not. + +And now let's consider what +we got for Hill Climbing. + +Do we want to use +backtracking? + +Sure. + +Do we want to use an +enqueued list? + +Sure. + +And it is informed, because it's +taking advantage of this + +extra information. + +It may not be in your problem. + +It's not often the case you've +got this information in a map. + +Your problem may not have any +heuristic measurement of + +distance to the goal. + +In which case, you +can't do it. + +But if you've got it, +you should use it. + +Oh, yeah, there's one more. + +And I've already given it away +by having it on my chart. + +It's called Beam Search. + +And just as Hill Climbing is +an analog of Depth-first + +Search, Beam Search is a +complement or addition of an + +informing heuristic to +Breadth-first Search. + +What you do is you start +off just like + +Breadth-first Search. + +But you say I'm going to limit +the number of paths I'm going + +to consider at any level to +some small, fixed number, + +like, in this case, +how about two. + +So, I'm going to say that +I have a Beam of + +two for my Beam Search. + +Otherwise, I proceed just +like Breadth-first + +Search, b, d, a, g. + +And now I've got that stupid +thing where I'm duplicating my + +nodes, because I'm forgetting +about the enqueued list. + +But to illustrate Beam Search, +what about I'm going to do now + +is I'm going to take all these +paths I've got at the second + +level, and I'm only going +to keep the best two. + +That's my beam width. + +And the best two are the two +that get closest to the goal. + +So, those four, b, c, a, +and d, which two get + +closest to the goal? + +Now, b and d. + +These guys are trimmed off. + +I'm only keeping two +at every level. + +Now, going down from b and +d, I have, at the next + +level, c and g. + +And now I've found the goal. + +So, I'm done. + +We could do that here, too. + +We could choose a Beam +Search, not bad. + +Let's see, let's try this +thing from the middle. + +Let's slow my speed +down a little bit. + +Now, are we going to see +anything going off to the left + +like we did with ordinary +Breadth-first Search? + +No, because it's smart. + +It doesn't say, I want to go to +a place that's further away + +from my goal. + +Now, let's see, maybe we can go +back to our algorithm now + +and talk about that enqueueing +mechanism and + +talk about Hill Climbing. + +Can I use the same basic search +mechanism, just change + +that one line again? + +Yes. + +How do I add new paths to +the queue this time? + +Well, it's very much like +Hill Climbing, right? + +I want to add them +to the front but + +with one little flourish. + +What's the flourish? + +[? Krishna, ?] what +do you think? + +Remember, I want to use my +heuristic information. + +So, I not only add them to the +front, but amongst the ones + +I'm adding to the front, +what do I do? + +AUDIENCE:Check the distance? + +PATRICK WINSTON: Check +the distance. + +And how do you arrange them? + +AUDIENCE:[? You ?] + +[? keep the ?] minimum +[? first. ?] + +PATRICK WINSTON: Yeah, you +can put the minimum + +first if you like. + +But let's sort them. + +We'll sort them, that will +keep everything straight. + +So Hill Climbing is +front-sorted. + +And, finally, how about Beam? + +What do we do with Beam Search +to add them to the queue? + +Well, it doesn't matter where we +add them, because all we're + +going to do is we're going +to keep the w best. + +So, with Beam, we'll just +abbreviate that by + +saying keep w best. + +Now, you have some of the basic + +searches in you're toolkit. + +There's one more that's +sometimes talked about. + +We've got Depth, Breadth, Best, +and Beam, one more is + +Best, Best-first Search. + +It's a variant where you say, +I've got this tree. + +It's got a bunch of paths that +terminate in leaves. + +Let me just always work on +the leaf node that's + +closest to the goal. + +It can skip around a little bit +from one place to another. + +Because as it pursues one path, +it may not do very well + +in some other path +quite distant. + +And the tree will become +the best one. + +We've actually seen an instance +of that in then + +integration program. + +It's capable of skipping all +over the place, because it's + +always taking the easiest +problem in the search tree, in + +the and/or tree, working +on that. + +That's Best-first Search. + +You can do these sorts +of things in + +continuous spaces, too. + +And you've done the +mathematics of + +that in 1802 or something. + +But in continuous spaces, the +Hill Climbing sometimes leads + +to problems or doesn't +do very well. + +What kind of a problem can you +encounter in a continuous + +space with Hill Climbing? + +Well, how would you do +Hill Climbing in + +a continuous space? + +Let's say we're in the +mountains, and a big + +fog has come up. + +We're trying to get to the +top of the hill before + +we freeze to death. + +And we take a few steps north, +a few steps east, west, and + +south using our compass. + +And we check to see which +direction seems to be doing + +the best job of getting +us moving upward. + +And that's our Hill Climbing +approach, right? + +We have explored four directions +we can go and pick + +the best one. + +And from there, we pick four, +try all those, pick the best + +one, and away we go. + +We've got ourselves a Hill +Climbing algorithm. + +What's wrong with it? + +Or what can be wrong with it? + +Sometimes it works just fine. + +Yes. + +SPEAKER 1: You might get stuck +in a local maximum. + +PATRICK WINSTON: We might get +stuck in a local maximum. + +So, problem letter a is that if +this is your space, it may + +look like that. + +And you may get stuck +on a local maximum. + +Is there any other kind of +problem that can come up? + +Well, it all depends on what +the space is like. + +Here's a problem where the +space has local maxima. + +Now, a lot of people have +been killed on Mt. + +Washington when the +fog comes up. + +And they do freeze +to death, why? + +The reason they freeze to death +is the Hill Climbing + +fails them, and they can't +get to the top + +to the ranger station. + +And the reason is that there +are large lawns on the + +shoulders of Mt. + +Washington. + +It's quite flat. + +So, it's the telephone +pole problem. + +That space looks like this. + +Well, this isn't what Mt. + +Washington looks like. + +But it's the telephone +pole problem. + +So, when you're wandering +around here, the idea of + +trying a few directions and +picking the one that's best + +doesn't help any, because +it's flat. + +That can be a problem +with Hill Climbing. + +Now, there's one more problem +with Hill Climbing that most + +people don't know about. + +But it works like this. + +This is a particularly +acute problem in + +high dimensional spaces. + +I'll illustrate it +here just in two. + +And I'm going to switch from +a regular kind of view to a + +contour map. + +So, my contour map is going to +betray the presence of a sharp + +bridge along the +45 degree line. + +Now you see how you can +get in trouble there. + +You get in trouble, because +if you take a step in each + +direction, every direction +takes you downhill. + +And you think you're +at the top. + +So, suppose you're right +here and you go north. + +That takes you down over +a contour line. + +If you go south, that +also takes you down + +over contour lines. + +Likewise, going west and east +all appear to be taking you + +down, whereas, in fact, you're +climbing a ridge. + +And that contour line is the +highest that I've shown. + +So, sometimes you +can get fooled-- + +not stuck, but fooled-- into +thinking you're at the top + +when you're actually not. + +Now, this is a model +something. + +This subject is about modeling +intelligence. + +And this is a kind of algorithm +you frequently need + +in order to build an +intelligent system. + +But do we have any kind of +Search happening in our heads? + +If we're going to model what +goes on inside our heads, do + +we have to model any kind of +searching in order to do the + +kinds of things that +we humans do? + +I suppose so. + +Anytime we make a plan, we're +actually evaluating a bunch of + +choices and seeing +how they work. + +Let me see if I can illustrate +it another way. + +This is a system that I showed +you a little bit of last time. + +And, shoot, I might as well +review one or two things here. + +I showed you a Macbeth story. + +This is the story +I showed you. + +And if you had this in a +humanities class, the simplest + +questions that might be asked +is why did Macduff kill + +Macbeth down there +at the bottom? + +Did I demonstrate the answering +of questions last + +time, or just the development +of the graph? + +I can't remember. + +But we'll do it again, anyway. + +This is somewhat stylized +English. + +Just so you'll know, +it doesn't have + +to be stylized English. + +This is English that's made +available to the Genesis + +system by way of something +called Story Workbench. + +There's no free lunch. + +Either you can use your human +resources to rewrite the plot + +in third grade English. + +Or you can use your human +resources to take a more + +natural, adult-type version of +the story and decorate it with + +annotations that make it +possible to absorb it. + +Just this summer, in a miracle +of summer [? Europe, ?] + +[? Brit ?] + +[? van ?] + +[? Zijp-- ?] + +one of you-- + +connected these two +systems together. + +So, we can now work with stories +that are expressed in + +pretty natural English. + +Everything in our system is +expressed in English, + +including common sense +knowledge-- + +like if somebody kills +you, you're dead-- + +but more importantly, for +today's illustration, that + +reflective level knowledge, +that knowledge about what + +revenge is. + +Here you are. + +You're in the humanities class, +and someone says, + +what's really going +on in the story? + +Not the details of who +kills whom, but is + +there a Pyrrhic victory? + +Does somebody have a success? + +Is there an act of revenge? + +These are all kinds of things +you might be asked about in + +some kind of humanities class. + +So, let me fire up the +genesis system. + +Pray for internet +connectivity. + +Launch the system on a read of +that Macbeth story that I + +showed you just a moment ago. + +At the moment, it's absorbing +information about background + +knowledge, and about reflective +level knowledge, + +and all that sort of thing. + +It's building itself +this thing we call + +an elaboration graph. + +It's not quite there yet. + +It's still reading background +knowledge. + +Now it's reading Macbeth. + +It's building it's elaboration +graph, the same thing you saw + +last time, except not quite. + +Do you see that stuff +down at the bottom? + +Those are higher level concepts +that it's managed to + +find in the Macbeth story. + +So, its found a revenge. + +How did it do that? + +It searched. + +It had a description of what a +revenge is, and it looked to + +see if that pattern +was exhibited in + +the elaboration graph. + +So, in a combination of things +that were said explicitly and + +things that were produced by +knee-jerk if/then rules, the + +elaboration graph was +sufficiently instantiated that + +the revenge pattern +could be found. + +That's interesting, Pyrrhic +victory is a little harder. + +You'd probably get an a if you +said, oh, there's a Pyrrhic + +victory in here. + +There it is. + +So, I'll blow that up a +little bit so you can + +see what that is. + +You know what a Pyrrhic +victory is. + +It's a situation where +everything seems to be going + +good at first, and +then not so hot. + +So, Macbeth wants to +be King down here. + +And eventually that leads +to becoming King. + +But too bad for Macbeth, because +eventually he gets + +killed in consequence. + +So, it's a Pyrrhic victory. + +All that produced by Search +programs who are looking + +through this graph. + +Now once you've got the +capability of doing that, of + +course, then you can find +all sorts of things. + +And you can report +them in English. + +But, more interestingly, you +can answer questions. + +Why did Macbeth-- + +it cares not a hoot about +capitalization. + +ARTIFICIAL INTELLIGENCE: On a +common sense level, it looks + +like Dr. Jekyll thinks Macduff +killed Macbeth because Macbeth + +angered Macduff on a +reflective level. + +It looks like Dr. Jekyll thinks +Macduff killed Macbeth + +as part of acts of mistake, +Pyrrhic victory, and revenge. + +PATRICK WINSTON: Pretty +corny speech output. + +But you see the point. + +How did it get the stuff on +the common sense level? + +The same way all those programs +that build goal trees + +report, answers the questions. + +It's just looking locally around +in the connections in + +the goal tree. + +How did it get the stuff on +the reflective level? + +By reporting on the searches +that produced information-- + +it does that by looking for +higher level thoughts about + +its own thoughts and reporting +in which of those higher level + +thoughts the incident we asked +about actually occurs. + +So, let's see, just for fun, we +might be interested in why + +Macbeth murdered Duncan. + +Wouldn't this be handy if you +hadn't actually read the play, + +and here it is, you've got +to write that paper? + +ARTIFICIAL INTELLIGENCE: +On a common sense + +level, it looks like-- + +PATRICK WINSTON: I'll pull the +plug on that, because that's + +just annoying. + +Yeah, pretty good, Macbeth wants +to be King, and Duncan + +is the King. + +Let's see, why did Macbeth +become King? + +Oh, it won't answer +the question + +unless I spell it right. + +I wouldn't be able to show that +to you until last spring. + +In fact, I wouldn't have been +able to show you this today + +until last week with a +tweak this morning. + +Because we've just now connected +the language output + +to, of course, [? Cass's ?] + +parser system, which is running +in reverse, in order + +to generate that English. + +So, that's something that has +never before been seen by any + +eyes but me. + +So, that will conclude what +we have to do today. \ No newline at end of file diff --git a/jLvgNmGuxGk.txt b/jLvgNmGuxGk.txt new file mode 100644 index 0000000000000000000000000000000000000000..987f1b68de77315c2a23e5ef3964809eda6987a2 --- /dev/null +++ b/jLvgNmGuxGk.txt @@ -0,0 +1,16834 @@ +align:start position:0% + +there's quiz one + + align:start position:0% +there's quiz one + + + align:start position:0% +there's quiz one +which will be out today and + + align:start position:0% +which will be out today and + + + align:start position:0% +which will be out today and +the rules for that are slightly + + align:start position:0% +the rules for that are slightly + + + align:start position:0% +the rules for that are slightly +different from the homework problems + + align:start position:0% +different from the homework problems + + + align:start position:0% +different from the homework problems +it counts twice as much as a homework + + align:start position:0% +it counts twice as much as a homework + + + align:start position:0% +it counts twice as much as a homework +problem + + align:start position:0% +problem + + + align:start position:0% +problem +and it's longer + + align:start position:0% +and it's longer + + + align:start position:0% +and it's longer +not twice as long but something like + + align:start position:0% +not twice as long but something like + + + align:start position:0% +not twice as long but something like +that and so you have also a little bit + + align:start position:0% +that and so you have also a little bit + + + align:start position:0% +that and so you have also a little bit +more time to do it it's not just one + + align:start position:0% +more time to do it it's not just one + + + align:start position:0% +more time to do it it's not just one +week + + align:start position:0% +week + + + align:start position:0% +week +but um + + align:start position:0% +but um + + + align:start position:0% +but um +it's a bit of work so don't leave it too + + align:start position:0% +it's a bit of work so don't leave it too + + + align:start position:0% +it's a bit of work so don't leave it too +late please start on it fairly soon + + align:start position:0% +late please start on it fairly soon + + + align:start position:0% +late please start on it fairly soon +and this is where you're supposed to + + align:start position:0% +and this is where you're supposed to + + + align:start position:0% +and this is where you're supposed to +work on your own + + align:start position:0% +work on your own + + + align:start position:0% +work on your own +uh not not collaborate so + + align:start position:0% +uh not not collaborate so + + + align:start position:0% +uh not not collaborate so +okay and it covers uh you know whatever + + align:start position:0% +okay and it covers uh you know whatever + + + align:start position:0% +okay and it covers uh you know whatever +we did up to this point + + align:start position:0% +we did up to this point + + + align:start position:0% +we did up to this point +uh with a bit more emphasis on recent + + align:start position:0% +uh with a bit more emphasis on recent + + + align:start position:0% +uh with a bit more emphasis on recent +material + + align:start position:0% +material + + + align:start position:0% +material +and i guess only the last question has + + align:start position:0% +and i guess only the last question has + + + align:start position:0% +and i guess only the last question has +to do with the patent we're discussing + + align:start position:0% +to do with the patent we're discussing + + + align:start position:0% +to do with the patent we're discussing +so + + align:start position:0% +so + + + align:start position:0% +so +i should be able to deal with the other + + align:start position:0% +i should be able to deal with the other + + + align:start position:0% +i should be able to deal with the other +four right away + + align:start position:0% +four right away + + + align:start position:0% +four right away +okay a little uh sidebar here about um + + align:start position:0% +okay a little uh sidebar here about um + + + align:start position:0% +okay a little uh sidebar here about um +intellectual property + + align:start position:0% +intellectual property + + + align:start position:0% +intellectual property +and + + align:start position:0% +and + + + align:start position:0% +and +starting off with the fact that some + + align:start position:0% +starting off with the fact that some + + + align:start position:0% +starting off with the fact that some +people don't like that terminology + + align:start position:0% +people don't like that terminology + + + align:start position:0% +people don't like that terminology +and um + + align:start position:0% +and um + + + align:start position:0% +and um +you know uh how can an idea be property + + align:start position:0% +you know uh how can an idea be property + + + align:start position:0% +you know uh how can an idea be property +a little bit like + + align:start position:0% +a little bit like + + + align:start position:0% +a little bit like +uh how can a company be a person + + align:start position:0% +uh how can a company be a person + + + align:start position:0% +uh how can a company be a person +well it's you know an awkward thing in + + align:start position:0% +well it's you know an awkward thing in + + + align:start position:0% +well it's you know an awkward thing in +law that + + align:start position:0% +law that + + + align:start position:0% +law that +you have to come up with some way of + + align:start position:0% +you have to come up with some way of + + + align:start position:0% +you have to come up with some way of +formalizing these things and so in this + + align:start position:0% +formalizing these things and so in this + + + align:start position:0% +formalizing these things and so in this +case + + align:start position:0% +case + + + align:start position:0% +case +ideas are treated as property to some + + align:start position:0% +ideas are treated as property to some + + + align:start position:0% +ideas are treated as property to some +extent there are several different types + + align:start position:0% +extent there are several different types + + + align:start position:0% +extent there are several different types +of intellectual property first of all we + + align:start position:0% +of intellectual property first of all we + + + align:start position:0% +of intellectual property first of all we +have patents which is what we'll be + + align:start position:0% +have patents which is what we'll be + + + align:start position:0% +have patents which is what we'll be +talking about and they're different + + align:start position:0% +talking about and they're different + + + align:start position:0% +talking about and they're different +types of patents + + align:start position:0% + + + + align:start position:0% + +the so-called utility patents + + align:start position:0% +the so-called utility patents + + + align:start position:0% +the so-called utility patents +i.e useful + + align:start position:0% +i.e useful + + + align:start position:0% +i.e useful +and not to say the others aren't useful + + align:start position:0% +and not to say the others aren't useful + + + align:start position:0% +and not to say the others aren't useful +but + + align:start position:0% + + + + align:start position:0% + +their design patterns + + align:start position:0% + + + + align:start position:0% + +so for example jerome little lamelton's + + align:start position:0% +so for example jerome little lamelton's + + + align:start position:0% +so for example jerome little lamelton's +first patent + + align:start position:0% +first patent + + + align:start position:0% +first patent +was a + + align:start position:0% +was a + + + align:start position:0% +was a +basically a design patent + + align:start position:0% +basically a design patent + + + align:start position:0% +basically a design patent +for a baseball cap with a hole in it and + + align:start position:0% +for a baseball cap with a hole in it and + + + align:start position:0% +for a baseball cap with a hole in it and +a tube + + align:start position:0% +a tube + + + align:start position:0% +a tube +that you could blow through so this is + + align:start position:0% +that you could blow through so this is + + + align:start position:0% +that you could blow through so this is +the inverse of the beer baseball cap and + + align:start position:0% +the inverse of the beer baseball cap and + + + align:start position:0% +the inverse of the beer baseball cap and +there'd be a propeller and as you blow + + align:start position:0% +there'd be a propeller and as you blow + + + align:start position:0% +there'd be a propeller and as you blow +through it the propeller would turn + + align:start position:0% +through it the propeller would turn + + + align:start position:0% +through it the propeller would turn +another famous design patent + + align:start position:0% +another famous design patent + + + align:start position:0% +another famous design patent +is apples designed for a cell phone + + align:start position:0% +is apples designed for a cell phone + + + align:start position:0% +is apples designed for a cell phone +and their design pattern says that it + + align:start position:0% +and their design pattern says that it + + + align:start position:0% +and their design pattern says that it +should be + + align:start position:0% +should be + + + align:start position:0% +should be +a rectangle with rounded corners + + align:start position:0% +a rectangle with rounded corners + + + align:start position:0% +a rectangle with rounded corners +and there was a lawsuit with where they + + align:start position:0% +and there was a lawsuit with where they + + + align:start position:0% +and there was a lawsuit with where they +sued samsung + + align:start position:0% +sued samsung + + + align:start position:0% +sued samsung +because their phone + + align:start position:0% +because their phone + + + align:start position:0% +because their phone +you know with a rectangle with rounded + + align:start position:0% +you know with a rectangle with rounded + + + align:start position:0% +you know with a rectangle with rounded +corners + + align:start position:0% +corners + + + align:start position:0% +corners +and the jury awarded uh apple a billion + + align:start position:0% +and the jury awarded uh apple a billion + + + align:start position:0% +and the jury awarded uh apple a billion +dollars so + + align:start position:0% +dollars so + + + align:start position:0% +dollars so +big money involves here and you know you + + align:start position:0% +big money involves here and you know you + + + align:start position:0% +big money involves here and you know you +might say well + + align:start position:0% +might say well + + + align:start position:0% +might say well +what should a cell phone look like other + + align:start position:0% +what should a cell phone look like other + + + align:start position:0% +what should a cell phone look like other +than this you know this is it but it's + + align:start position:0% +than this you know this is it but it's + + + align:start position:0% +than this you know this is it but it's +not completely crazy because at the time + + align:start position:0% +not completely crazy because at the time + + + align:start position:0% +not completely crazy because at the time +they invented it you know phones were + + align:start position:0% +they invented it you know phones were + + + align:start position:0% +they invented it you know phones were +these big concrete things you held in + + align:start position:0% +these big concrete things you held in + + + align:start position:0% +these big concrete things you held in +your hand and so + + align:start position:0% +your hand and so + + + align:start position:0% +your hand and so +anyway uh not + + align:start position:0% +anyway uh not + + + align:start position:0% +anyway uh not +not to argue about the merits of this + + align:start position:0% +not to argue about the merits of this + + + align:start position:0% +not to argue about the merits of this +and and of course it's been appealed and + + align:start position:0% +and and of course it's been appealed and + + + align:start position:0% +and and of course it's been appealed and +so in the end i don't know what will + + align:start position:0% +so in the end i don't know what will + + + align:start position:0% +so in the end i don't know what will +happen i guess some some large amount of + + align:start position:0% +happen i guess some some large amount of + + + align:start position:0% +happen i guess some some large amount of +money will transfer + + align:start position:0% +money will transfer + + + align:start position:0% +money will transfer +uh change hands an amount of money which + + align:start position:0% +uh change hands an amount of money which + + + align:start position:0% +uh change hands an amount of money which +is astronomical to us mere mortals but + + align:start position:0% +is astronomical to us mere mortals but + + + align:start position:0% +is astronomical to us mere mortals but +probably for these companies you know + + align:start position:0% +probably for these companies you know + + + align:start position:0% +probably for these companies you know +it's a small change so + + align:start position:0% +it's a small change so + + + align:start position:0% +it's a small change so +we shouldn't feel too sorry for them + + align:start position:0% +we shouldn't feel too sorry for them + + + align:start position:0% +we shouldn't feel too sorry for them +so patents + + align:start position:0% +so patents + + + align:start position:0% +so patents +we mentioned last time this was the kind + + align:start position:0% +we mentioned last time this was the kind + + + align:start position:0% +we mentioned last time this was the kind +of social contract where + + align:start position:0% +of social contract where + + + align:start position:0% +of social contract where +you explain exactly how to do something + + align:start position:0% +you explain exactly how to do something + + + align:start position:0% +you explain exactly how to do something +in return for having a limited monopoly + + align:start position:0% +in return for having a limited monopoly + + + align:start position:0% +in return for having a limited monopoly +that lasts a certain number of years and + + align:start position:0% +that lasts a certain number of years and + + + align:start position:0% +that lasts a certain number of years and +the you know the rules change slightly + + align:start position:0% +the you know the rules change slightly + + + align:start position:0% +the you know the rules change slightly +as as time goes on + + align:start position:0% +as as time goes on + + + align:start position:0% +as as time goes on +uh by the way um + + align:start position:0% +uh by the way um + + + align:start position:0% +uh by the way um +you are supposed to explain + + align:start position:0% +you are supposed to explain + + + align:start position:0% +you are supposed to explain +uh how to do it and in particular + + align:start position:0% +uh how to do it and in particular + + + align:start position:0% +uh how to do it and in particular +if you know a good way of doing it and + + align:start position:0% +if you know a good way of doing it and + + + align:start position:0% +if you know a good way of doing it and +in your patent you only describe a lousy + + align:start position:0% +in your patent you only describe a lousy + + + align:start position:0% +in your patent you only describe a lousy +way of doing it that could be grounds + + align:start position:0% +way of doing it that could be grounds + + + align:start position:0% +way of doing it that could be grounds +later on for invalidating a patent + + align:start position:0% +later on for invalidating a patent + + + align:start position:0% +later on for invalidating a patent +and + + align:start position:0% +and + + + align:start position:0% +and +that's called best mode so there's lots + + align:start position:0% +that's called best mode so there's lots + + + align:start position:0% +that's called best mode so there's lots +and lots of + + align:start position:0% +and lots of + + + align:start position:0% +and lots of +terminology + + align:start position:0% +terminology + + + align:start position:0% +terminology +and + + align:start position:0% +and + + + align:start position:0% +and +in the litigation there's sort of + + align:start position:0% +in the litigation there's sort of + + + align:start position:0% +in the litigation there's sort of +standard things that that come up one of + + align:start position:0% +standard things that that come up one of + + + align:start position:0% +standard things that that come up one of +them is best mode so in in one machine + + align:start position:0% +them is best mode so in in one machine + + + align:start position:0% +them is best mode so in in one machine +vision patent + + align:start position:0% +vision patent + + + align:start position:0% +vision patent +for a wheel alignment + + align:start position:0% +for a wheel alignment + + + align:start position:0% +for a wheel alignment +so that one has cameras and leds and + + align:start position:0% +so that one has cameras and leds and + + + align:start position:0% +so that one has cameras and leds and +it determines the axis of rotation of + + align:start position:0% +it determines the axis of rotation of + + + align:start position:0% +it determines the axis of rotation of +the wheel + + align:start position:0% +the wheel + + + align:start position:0% +the wheel +and the axis of the steering that you it + + align:start position:0% +and the axis of the steering that you it + + + align:start position:0% +and the axis of the steering that you it +turns around when you + + align:start position:0% +turns around when you + + + align:start position:0% +turns around when you +turn your steering wheel + + align:start position:0% +turn your steering wheel + + + align:start position:0% +turn your steering wheel +and uh + + align:start position:0% +and uh + + + align:start position:0% +and uh +the pattern that was + + align:start position:0% +the pattern that was + + + align:start position:0% +the pattern that was +claimed to have been infringed + + align:start position:0% +claimed to have been infringed + + + align:start position:0% +claimed to have been infringed +uh did not uh disclose the best mode it + + align:start position:0% +uh did not uh disclose the best mode it + + + align:start position:0% +uh did not uh disclose the best mode it +disclosed the method that if you + + align:start position:0% +disclosed the method that if you + + + align:start position:0% +disclosed the method that if you +actually implement it + + align:start position:0% +actually implement it + + + align:start position:0% +actually implement it +uh it gives gives you the correct answer + + align:start position:0% +uh it gives gives you the correct answer + + + align:start position:0% +uh it gives gives you the correct answer +if you have perfect measurements + + align:start position:0% +if you have perfect measurements + + + align:start position:0% +if you have perfect measurements +but with uh realistic measurements it + + align:start position:0% +but with uh realistic measurements it + + + align:start position:0% +but with uh realistic measurements it +would have an error of you know a degree + + align:start position:0% +would have an error of you know a degree + + + align:start position:0% +would have an error of you know a degree +or two + + align:start position:0% +or two + + + align:start position:0% +or two +and that's not good enough you know if + + align:start position:0% +and that's not good enough you know if + + + align:start position:0% +and that's not good enough you know if +you have a car like a bmw they measure + + align:start position:0% +you have a car like a bmw they measure + + + align:start position:0% +you have a car like a bmw they measure +they specify those angles to 0.01 + + align:start position:0% +they specify those angles to 0.01 + + + align:start position:0% +they specify those angles to 0.01 +degrees so anyway so they had a problem + + align:start position:0% +degrees so anyway so they had a problem + + + align:start position:0% +degrees so anyway so they had a problem +there because they did not disclose the + + align:start position:0% +there because they did not disclose the + + + align:start position:0% +there because they did not disclose the +best mode + + align:start position:0% +best mode + + + align:start position:0% +best mode +okay utility patterns and we talked + + align:start position:0% +okay utility patterns and we talked + + + align:start position:0% +okay utility patterns and we talked +about the structure of those i'll just + + align:start position:0% +about the structure of those i'll just + + + align:start position:0% +about the structure of those i'll just +briefly talk about some of the others so + + align:start position:0% +briefly talk about some of the others so + + + align:start position:0% +briefly talk about some of the others so +copyright um you know you can protect + + align:start position:0% +copyright um you know you can protect + + + align:start position:0% +copyright um you know you can protect +artistic expression + + align:start position:0% +artistic expression + + + align:start position:0% +artistic expression +using copyright so if you write a book + + align:start position:0% +using copyright so if you write a book + + + align:start position:0% +using copyright so if you write a book +there's a copyright on that if you + + align:start position:0% +there's a copyright on that if you + + + align:start position:0% +there's a copyright on that if you +record a song there's a copyright on + + align:start position:0% +record a song there's a copyright on + + + align:start position:0% +record a song there's a copyright on +that + + align:start position:0% +that + + + align:start position:0% +that +if you choreograph some ballet as a + + align:start position:0% +if you choreograph some ballet as a + + + align:start position:0% +if you choreograph some ballet as a +copyright on that + + align:start position:0% +copyright on that + + + align:start position:0% +copyright on that +and + + align:start position:0% +and + + + align:start position:0% +and +their + + align:start position:0% +their + + + align:start position:0% +their +exceptions so for example + + align:start position:0% +exceptions so for example + + + align:start position:0% +exceptions so for example +if i want to talk about some topic + + align:start position:0% +if i want to talk about some topic + + + align:start position:0% +if i want to talk about some topic +i am allowed in class to present a + + align:start position:0% +i am allowed in class to present a + + + align:start position:0% +i am allowed in class to present a +portion of that material without + + align:start position:0% +portion of that material without + + + align:start position:0% +portion of that material without +violating the copyright without having + + align:start position:0% +violating the copyright without having + + + align:start position:0% +violating the copyright without having +to ask the author you know how much do + + align:start position:0% +to ask the author you know how much do + + + align:start position:0% +to ask the author you know how much do +you want for me to use your + + align:start position:0% +you want for me to use your + + + align:start position:0% +you want for me to use your +product + + align:start position:0% +product + + + align:start position:0% +product +there are also exceptions + + align:start position:0% +there are also exceptions + + + align:start position:0% +there are also exceptions +where you use + + align:start position:0% +where you use + + + align:start position:0% +where you use +extracts so for example if you're + + align:start position:0% +extracts so for example if you're + + + align:start position:0% +extracts so for example if you're +writing a news article + + align:start position:0% +writing a news article + + + align:start position:0% +writing a news article +or say you've got a blog about a movie + + align:start position:0% +or say you've got a blog about a movie + + + align:start position:0% +or say you've got a blog about a movie +and there's a particular part of the + + align:start position:0% +and there's a particular part of the + + + align:start position:0% +and there's a particular part of the +movie that you'd like to talk about + + align:start position:0% +movie that you'd like to talk about + + + align:start position:0% +movie that you'd like to talk about +under certain circumstances you can clip + + align:start position:0% +under certain circumstances you can clip + + + align:start position:0% +under certain circumstances you can clip +that out and use it + + align:start position:0% +that out and use it + + + align:start position:0% +that out and use it +and of course you can imagine there's a + + align:start position:0% +and of course you can imagine there's a + + + align:start position:0% +and of course you can imagine there's a +lot of fun that lawyers have with this + + align:start position:0% +lot of fun that lawyers have with this + + + align:start position:0% +lot of fun that lawyers have with this +because a lot of music is extracted from + + align:start position:0% +because a lot of music is extracted from + + + align:start position:0% +because a lot of music is extracted from +other music and put together and is that + + align:start position:0% +other music and put together and is that + + + align:start position:0% +other music and put together and is that +legal or is that copyright infringement + + align:start position:0% +legal or is that copyright infringement + + + align:start position:0% +legal or is that copyright infringement +copyright used to be basically + + align:start position:0% +copyright used to be basically + + + align:start position:0% +copyright used to be basically +for the lifetime of the author you know + + align:start position:0% +for the lifetime of the author you know + + + align:start position:0% +for the lifetime of the author you know +if you write a book you should benefit + + align:start position:0% +if you write a book you should benefit + + + align:start position:0% +if you write a book you should benefit +up to a certain + + align:start position:0% +up to a certain + + + align:start position:0% +up to a certain +point when you're not around and you + + align:start position:0% +point when you're not around and you + + + align:start position:0% +point when you're not around and you +don't benefit well of course the heirs + + align:start position:0% +don't benefit well of course the heirs + + + align:start position:0% +don't benefit well of course the heirs +of famous authors didn't like that so + + align:start position:0% +of famous authors didn't like that so + + + align:start position:0% +of famous authors didn't like that so +that was changed + + align:start position:0% +that was changed + + + align:start position:0% +that was changed +and um + + align:start position:0% +and um + + + align:start position:0% +and um +now we have the the sony bono uh + + align:start position:0% +now we have the the sony bono uh + + + align:start position:0% +now we have the the sony bono uh +system of copyright basically + + align:start position:0% +system of copyright basically + + + align:start position:0% +system of copyright basically +he was the person who convinced congress + + align:start position:0% +he was the person who convinced congress + + + align:start position:0% +he was the person who convinced congress +to change the laws and now it's uh + + align:start position:0% +to change the laws and now it's uh + + + align:start position:0% +to change the laws and now it's uh +author's life plus 75 years and they've + + align:start position:0% +author's life plus 75 years and they've + + + align:start position:0% +author's life plus 75 years and they've +been periodically updating it so it's + + align:start position:0% +been periodically updating it so it's + + + align:start position:0% +been periodically updating it so it's +basically author's life plus infinity + + align:start position:0% +basically author's life plus infinity + + + align:start position:0% +basically author's life plus infinity +because every time we get close to the + + align:start position:0% +because every time we get close to the + + + align:start position:0% +because every time we get close to the +limit they say oh well let's upgrade + + align:start position:0% +limit they say oh well let's upgrade + + + align:start position:0% +limit they say oh well let's upgrade +these poor heirs they can't live without + + align:start position:0% +these poor heirs they can't live without + + + align:start position:0% +these poor heirs they can't live without +the royalties from from this so + + align:start position:0% +the royalties from from this so + + + align:start position:0% +the royalties from from this so +excuse me if i'm being sarcastic so + + align:start position:0% +excuse me if i'm being sarcastic so + + + align:start position:0% +excuse me if i'm being sarcastic so +okay so that's copyright and by the way + + align:start position:0% +okay so that's copyright and by the way + + + align:start position:0% +okay so that's copyright and by the way +that was very important for a while uh + + align:start position:0% +that was very important for a while uh + + + align:start position:0% +that was very important for a while uh +and still is uh in software because + + align:start position:0% +and still is uh in software because + + + align:start position:0% +and still is uh in software because +again + + align:start position:0% +again + + + align:start position:0% +again +the rule was you couldn't copy you + + align:start position:0% +the rule was you couldn't copy you + + + align:start position:0% +the rule was you couldn't copy you +couldn't patent uh mathematics or or an + + align:start position:0% +couldn't patent uh mathematics or or an + + + align:start position:0% +couldn't patent uh mathematics or or an +idea abstract idea uh and so a lot of uh + + align:start position:0% +idea abstract idea uh and so a lot of uh + + + align:start position:0% +idea abstract idea uh and so a lot of uh +the courts typically held that you know + + align:start position:0% +the courts typically held that you know + + + align:start position:0% +the courts typically held that you know +that's what programs are their ideas + + align:start position:0% +that's what programs are their ideas + + + align:start position:0% +that's what programs are their ideas +they're abstract stuff they're not you + + align:start position:0% +they're abstract stuff they're not you + + + align:start position:0% +they're abstract stuff they're not you +can't hold them and weigh them + + align:start position:0% +can't hold them and weigh them + + + align:start position:0% +can't hold them and weigh them +and so uh the way people protected + + align:start position:0% +and so uh the way people protected + + + align:start position:0% +and so uh the way people protected +themselves was to send their programs + + align:start position:0% +themselves was to send their programs + + + align:start position:0% +themselves was to send their programs +into the copyright office + + align:start position:0% +into the copyright office + + + align:start position:0% +into the copyright office +and register them there and + + align:start position:0% +and register them there and + + + align:start position:0% +and register them there and +you can imagine that you know say you + + align:start position:0% +you can imagine that you know say you + + + align:start position:0% +you can imagine that you know say you +have some operating system like ibm 360 + + align:start position:0% +have some operating system like ibm 360 + + + align:start position:0% +have some operating system like ibm 360 +operating system and you send in your + + align:start position:0% +operating system and you send in your + + + align:start position:0% +operating system and you send in your +750 million lines of code to the + + align:start position:0% +750 million lines of code to the + + + align:start position:0% +750 million lines of code to the +copyright office + + align:start position:0% +copyright office + + + align:start position:0% +copyright office +that was quite quite an exciting event + + align:start position:0% +that was quite quite an exciting event + + + align:start position:0% +that was quite quite an exciting event +and + + align:start position:0% +and + + + align:start position:0% +and +certainly if someone + + align:start position:0% +certainly if someone + + + align:start position:0% +certainly if someone +makes an exact copy of your program then + + align:start position:0% +makes an exact copy of your program then + + + align:start position:0% +makes an exact copy of your program then +you can sue them under under this law of + + align:start position:0% +you can sue them under under this law of + + + align:start position:0% +you can sue them under under this law of +course uh + + align:start position:0% + + + + align:start position:0% + +you know with all of these they're + + align:start position:0% +you know with all of these they're + + + align:start position:0% +you know with all of these they're +people who are working to get around + + align:start position:0% +people who are working to get around + + + align:start position:0% +people who are working to get around +these laws and so in the case of + + align:start position:0% +these laws and so in the case of + + + align:start position:0% +these laws and so in the case of +copyright there was this notion of a + + align:start position:0% +copyright there was this notion of a + + + align:start position:0% +copyright there was this notion of a +clean room + + align:start position:0% +clean room + + + align:start position:0% +clean room +so what you would do is + + align:start position:0% +so what you would do is + + + align:start position:0% +so what you would do is +you'd have a bunch of people that + + align:start position:0% +you'd have a bunch of people that + + + align:start position:0% +you'd have a bunch of people that +understood programs well analyze what + + align:start position:0% +understood programs well analyze what + + + align:start position:0% +understood programs well analyze what +someone else's program is doing + + align:start position:0% +someone else's program is doing + + + align:start position:0% +someone else's program is doing +kind of reverse engineering it + + align:start position:0% +kind of reverse engineering it + + + align:start position:0% +kind of reverse engineering it +but they weren't allowed to show it to + + align:start position:0% +but they weren't allowed to show it to + + + align:start position:0% +but they weren't allowed to show it to +another group of people + + align:start position:0% +another group of people + + + align:start position:0% +another group of people +they were able to they were only able to + + align:start position:0% +they were able to they were only able to + + + align:start position:0% +they were able to they were only able to +tell them what what it does and then + + align:start position:0% +tell them what what it does and then + + + align:start position:0% +tell them what what it does and then +this other group of people would write + + align:start position:0% +this other group of people would write + + + align:start position:0% +this other group of people would write +the code and supposedly because they + + align:start position:0% +the code and supposedly because they + + + align:start position:0% +the code and supposedly because they +didn't see the original code there was + + align:start position:0% +didn't see the original code there was + + + align:start position:0% +didn't see the original code there was +not a copyright violation so + + align:start position:0% +not a copyright violation so + + + align:start position:0% +not a copyright violation so +okay um not sure that's + + align:start position:0% +okay um not sure that's + + + align:start position:0% +okay um not sure that's +you know + + align:start position:0% +you know + + + align:start position:0% +you know +and it's not totally unreasonable + + align:start position:0% +and it's not totally unreasonable + + + align:start position:0% +and it's not totally unreasonable +in that if you look at the code line by + + align:start position:0% +in that if you look at the code line by + + + align:start position:0% +in that if you look at the code line by +line it's likely to be totally different + + align:start position:0% +line it's likely to be totally different + + + align:start position:0% +line it's likely to be totally different +you know they'll use different variable + + align:start position:0% +you know they'll use different variable + + + align:start position:0% +you know they'll use different variable +names and stuff so + + align:start position:0% +names and stuff so + + + align:start position:0% +names and stuff so +okay then there's a trademark so + + align:start position:0% +okay then there's a trademark so + + + align:start position:0% +okay then there's a trademark so +trademark + + align:start position:0% +trademark + + + align:start position:0% +trademark +is um + + align:start position:0% +is um + + + align:start position:0% +is um +much more restricted it's just you know + + align:start position:0% +much more restricted it's just you know + + + align:start position:0% +much more restricted it's just you know +if you want to + + align:start position:0% +if you want to + + + align:start position:0% +if you want to +call your company dunker donuts you can + + align:start position:0% +call your company dunker donuts you can + + + align:start position:0% +call your company dunker donuts you can +uh trademark that + + align:start position:0% +uh trademark that + + + align:start position:0% +uh trademark that +and but it has to be + + align:start position:0% +and but it has to be + + + align:start position:0% +and but it has to be +uh unique in the field and it has to not + + align:start position:0% +uh unique in the field and it has to not + + + align:start position:0% +uh unique in the field and it has to not +be + + align:start position:0% +be + + + align:start position:0% +be +you know there's a whole bunch of rules + + align:start position:0% +you know there's a whole bunch of rules + + + align:start position:0% +you know there's a whole bunch of rules +but basically you can't use a common + + align:start position:0% +but basically you can't use a common + + + align:start position:0% +but basically you can't use a common +word like you can't call your company + + align:start position:0% +word like you can't call your company + + + align:start position:0% +word like you can't call your company +time space because that's those are + + align:start position:0% +time space because that's those are + + + align:start position:0% +time space because that's those are +common words and so a lot of company + + align:start position:0% +common words and so a lot of company + + + align:start position:0% +common words and so a lot of company +names are slightly misspelled versions + + align:start position:0% +names are slightly misspelled versions + + + align:start position:0% +names are slightly misspelled versions +of common words + + align:start position:0% +of common words + + + align:start position:0% +of common words +the other thing is that + + align:start position:0% +the other thing is that + + + align:start position:0% +the other thing is that +the trademark may include + + align:start position:0% +the trademark may include + + + align:start position:0% +the trademark may include +particular shapes particular markings so + + align:start position:0% +particular shapes particular markings so + + + align:start position:0% +particular shapes particular markings so +you can distort some later + + align:start position:0% +you can distort some later + + + align:start position:0% +you can distort some later +and color + + align:start position:0% +and color + + + align:start position:0% +and color +so you know dunker donuts + + align:start position:0% +so you know dunker donuts + + + align:start position:0% +so you know dunker donuts +has two colors that they've copyrighted + + align:start position:0% +has two colors that they've copyrighted + + + align:start position:0% +has two colors that they've copyrighted +and i'm proud to say i have hats that + + align:start position:0% +and i'm proud to say i have hats that + + + align:start position:0% +and i'm proud to say i have hats that +have both of those colors they're very + + align:start position:0% +have both of those colors they're very + + + align:start position:0% +have both of those colors they're very +useful in hunting season which is + + align:start position:0% +useful in hunting season which is + + + align:start position:0% +useful in hunting season which is +approximately what's happening right now + + align:start position:0% +approximately what's happening right now + + + align:start position:0% +approximately what's happening right now +where i live so + + align:start position:0% +where i live so + + + align:start position:0% +where i live so +you can use color to protect yourself + + align:start position:0% +you can use color to protect yourself + + + align:start position:0% +you can use color to protect yourself +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +they have to be unique to the field so + + align:start position:0% +they have to be unique to the field so + + + align:start position:0% +they have to be unique to the field so +you may have a trademark on the name + + align:start position:0% +you may have a trademark on the name + + + align:start position:0% +you may have a trademark on the name +in the rubber industry + + align:start position:0% +in the rubber industry + + + align:start position:0% +in the rubber industry +uh and someone else has it in the + + align:start position:0% +uh and someone else has it in the + + + align:start position:0% +uh and someone else has it in the +semiconductor industry they don't + + align:start position:0% +semiconductor industry they don't + + + align:start position:0% +semiconductor industry they don't +conflict and + + align:start position:0% +conflict and + + + align:start position:0% +conflict and +there's a famous case about that where + + align:start position:0% +there's a famous case about that where + + + align:start position:0% +there's a famous case about that where +again apple apple sued the beatles + + align:start position:0% +again apple apple sued the beatles + + + align:start position:0% +again apple apple sued the beatles +why well because when the beatles + + align:start position:0% +why well because when the beatles + + + align:start position:0% +why well because when the beatles +started + + align:start position:0% +started + + + align:start position:0% +started +they formed their own company called + + align:start position:0% +they formed their own company called + + + align:start position:0% +they formed their own company called +apple + + align:start position:0% +apple + + + align:start position:0% +apple +may not know that but in any case so + + align:start position:0% +may not know that but in any case so + + + align:start position:0% +may not know that but in any case so +apple sued them and they lost because + + align:start position:0% +apple sued them and they lost because + + + align:start position:0% +apple sued them and they lost because +it's they're not there's no confusion of + + align:start position:0% +it's they're not there's no confusion of + + + align:start position:0% +it's they're not there's no confusion of +the client the customer right they're in + + align:start position:0% +the client the customer right they're in + + + align:start position:0% +the client the customer right they're in +two totally different fields one is + + align:start position:0% +two totally different fields one is + + + align:start position:0% +two totally different fields one is +music + + align:start position:0% +music + + + align:start position:0% +music +and the other one is computers and of + + align:start position:0% +and the other one is computers and of + + + align:start position:0% +and the other one is computers and of +course apple claimed oh well but we + + align:start position:0% +course apple claimed oh well but we + + + align:start position:0% +course apple claimed oh well but we +distribute music so it's it is the same + + align:start position:0% +distribute music so it's it is the same + + + align:start position:0% +distribute music so it's it is the same +thing well whatever anyway + + align:start position:0% +thing well whatever anyway + + + align:start position:0% +thing well whatever anyway +um + + align:start position:0% +um + + + align:start position:0% +um +then + + align:start position:0% +then + + + align:start position:0% +then +the last thing is trade secret which is + + align:start position:0% +the last thing is trade secret which is + + + align:start position:0% +the last thing is trade secret which is +you know no protection at all you just + + align:start position:0% +you know no protection at all you just + + + align:start position:0% +you know no protection at all you just +hide what you're doing you don't tell + + align:start position:0% +hide what you're doing you don't tell + + + align:start position:0% +hide what you're doing you don't tell +anyone exactly how you're doing it and + + align:start position:0% +anyone exactly how you're doing it and + + + align:start position:0% +anyone exactly how you're doing it and +you know classic example of that is + + align:start position:0% +you know classic example of that is + + + align:start position:0% +you know classic example of that is +coca-cola + + align:start position:0% +coca-cola + + + align:start position:0% +coca-cola +there's a safe down in atlanta georgia + + align:start position:0% +there's a safe down in atlanta georgia + + + align:start position:0% +there's a safe down in atlanta georgia +which has the formula for the + + align:start position:0% +which has the formula for the + + + align:start position:0% +which has the formula for the +ingredients in coca-cola + + align:start position:0% +ingredients in coca-cola + + + align:start position:0% +ingredients in coca-cola +and supposedly you know + + align:start position:0% +and supposedly you know + + + align:start position:0% +and supposedly you know +very few people know what's what's in + + align:start position:0% +very few people know what's what's in + + + align:start position:0% +very few people know what's what's in +there and + + align:start position:0% +there and + + + align:start position:0% +there and +uh the danger of course of i mean the + + align:start position:0% +uh the danger of course of i mean the + + + align:start position:0% +uh the danger of course of i mean the +good part is that it's unlimited i mean + + align:start position:0% +good part is that it's unlimited i mean + + + align:start position:0% +good part is that it's unlimited i mean +there's no like expiration date like on + + align:start position:0% +there's no like expiration date like on + + + align:start position:0% +there's no like expiration date like on +patents and the bad part is you know if + + align:start position:0% +patents and the bad part is you know if + + + align:start position:0% +patents and the bad part is you know if +it ever comes out there's no recourse + + align:start position:0% +it ever comes out there's no recourse + + + align:start position:0% +it ever comes out there's no recourse +there it is everyone now knows what to + + align:start position:0% +there it is everyone now knows what to + + + align:start position:0% +there it is everyone now knows what to +mix up to make coca-cola so + + align:start position:0% +mix up to make coca-cola so + + + align:start position:0% +mix up to make coca-cola so +um it's a risky uh thing but it's + + align:start position:0% +um it's a risky uh thing but it's + + + align:start position:0% +um it's a risky uh thing but it's +certainly much cheaper than pursuing + + align:start position:0% +certainly much cheaper than pursuing + + + align:start position:0% +certainly much cheaper than pursuing +some of the other avenues you don't have + + align:start position:0% +some of the other avenues you don't have + + + align:start position:0% +some of the other avenues you don't have +to pay lawyers for it + + align:start position:0% +to pay lawyers for it + + + align:start position:0% +to pay lawyers for it +and there is a certain + + align:start position:0% +and there is a certain + + + align:start position:0% +and there is a certain +legal recourse you know if somebody + + align:start position:0% +legal recourse you know if somebody + + + align:start position:0% +legal recourse you know if somebody +signs a non-disclosure agreement when + + align:start position:0% +signs a non-disclosure agreement when + + + align:start position:0% +signs a non-disclosure agreement when +joining your company and then they walk + + align:start position:0% +joining your company and then they walk + + + align:start position:0% +joining your company and then they walk +off with a formula for coca-cola and + + align:start position:0% +off with a formula for coca-cola and + + + align:start position:0% +off with a formula for coca-cola and +tell pepsi caller how to do it then you + + align:start position:0% +tell pepsi caller how to do it then you + + + align:start position:0% +tell pepsi caller how to do it then you +can sue them but you know the cat's out + + align:start position:0% +can sue them but you know the cat's out + + + align:start position:0% +can sue them but you know the cat's out +of the bag it's not + + align:start position:0% +of the bag it's not + + + align:start position:0% +of the bag it's not +so easy to recover from that kind of + + align:start position:0% +so easy to recover from that kind of + + + align:start position:0% +so easy to recover from that kind of +loss + + align:start position:0% +loss + + + align:start position:0% +loss +okay just a quick um overview of + + align:start position:0% +okay just a quick um overview of + + + align:start position:0% +okay just a quick um overview of +what's called the intellectual property + + align:start position:0% +what's called the intellectual property + + + align:start position:0% +what's called the intellectual property +and you know richard stallman would + + align:start position:0% +and you know richard stallman would + + + align:start position:0% +and you know richard stallman would +definitely complain that i use that + + align:start position:0% +definitely complain that i use that + + + align:start position:0% +definitely complain that i use that +terminology because he doesn't think + + align:start position:0% +terminology because he doesn't think + + + align:start position:0% +terminology because he doesn't think +that + + align:start position:0% +that + + + align:start position:0% +that +ideas should be treated as property just + + align:start position:0% +ideas should be treated as property just + + + align:start position:0% +ideas should be treated as property just +as some people don't think that + + align:start position:0% +as some people don't think that + + + align:start position:0% +as some people don't think that +companies should be treated as persons + + align:start position:0% +companies should be treated as persons + + + align:start position:0% +companies should be treated as persons +in under the law but there you are + + align:start position:0% +in under the law but there you are + + + align:start position:0% +in under the law but there you are +okay back to the particular patent so + + align:start position:0% +okay back to the particular patent so + + + align:start position:0% +okay back to the particular patent so +this particular patent is kind of real + + align:start position:0% +this particular patent is kind of real + + + align:start position:0% +this particular patent is kind of real +low level + + align:start position:0% +low level + + + align:start position:0% +low level +i wanted to start with something very + + align:start position:0% +i wanted to start with something very + + + align:start position:0% +i wanted to start with something very +simple + + align:start position:0% +simple + + + align:start position:0% +simple +you know finding edges + + align:start position:0% +you know finding edges + + + align:start position:0% +you know finding edges +very accurately finding edges very + + align:start position:0% +very accurately finding edges very + + + align:start position:0% +very accurately finding edges very +accurately so where are we going with + + align:start position:0% +accurately so where are we going with + + + align:start position:0% +accurately so where are we going with +that well the idea is that once we found + + align:start position:0% +that well the idea is that once we found + + + align:start position:0% +that well the idea is that once we found +edges and we're describing uh + + align:start position:0% +edges and we're describing uh + + + align:start position:0% +edges and we're describing uh +images using edges + + align:start position:0% +images using edges + + + align:start position:0% +images using edges +we can + + align:start position:0% +we can + + + align:start position:0% +we can +do more elaborate things like + + align:start position:0% +do more elaborate things like + + + align:start position:0% +do more elaborate things like +recognition and + + align:start position:0% +recognition and + + + align:start position:0% +recognition and +determining the position and determining + + align:start position:0% +determining the position and determining + + + align:start position:0% +determining the position and determining +the attitude of an object and most of uh + + align:start position:0% +the attitude of an object and most of uh + + + align:start position:0% +the attitude of an object and most of uh +what we'll be doing + + align:start position:0% +what we'll be doing + + + align:start position:0% +what we'll be doing +after finishing with this pattern is in + + align:start position:0% +after finishing with this pattern is in + + + align:start position:0% +after finishing with this pattern is in +in 2d where you know the world of course + + align:start position:0% +in 2d where you know the world of course + + + align:start position:0% +in 2d where you know the world of course +the 3d but there are lots of cases where + + align:start position:0% +the 3d but there are lots of cases where + + + align:start position:0% +the 3d but there are lots of cases where +2d machine vision is incredibly + + align:start position:0% +2d machine vision is incredibly + + + align:start position:0% +2d machine vision is incredibly +successful + + align:start position:0% +successful + + + align:start position:0% +successful +and um you know + + align:start position:0% +and um you know + + + align:start position:0% +and um you know +one thing that's important to point out + + align:start position:0% +one thing that's important to point out + + + align:start position:0% +one thing that's important to point out +is that it has to be incredibly accurate + + align:start position:0% +is that it has to be incredibly accurate + + + align:start position:0% +is that it has to be incredibly accurate +you know like if if your thing works 70 + + align:start position:0% +you know like if if your thing works 70 + + + align:start position:0% +you know like if if your thing works 70 +of the time + + align:start position:0% +of the time + + + align:start position:0% +of the time +forget it + + align:start position:0% +forget it + + + align:start position:0% +forget it +it's got to be + + align:start position:0% +it's got to be + + + align:start position:0% +it's got to be +working + + align:start position:0% +working + + + align:start position:0% +working +99.999 of the time so these methods are + + align:start position:0% +99.999 of the time so these methods are + + + align:start position:0% +99.999 of the time so these methods are +you know very carefully thought out and + + align:start position:0% +you know very carefully thought out and + + + align:start position:0% +you know very carefully thought out and +uh + + align:start position:0% +uh + + + align:start position:0% +uh +tuned to have extremely good performance + + align:start position:0% +tuned to have extremely good performance + + + align:start position:0% +tuned to have extremely good performance +and + + align:start position:0% +and + + + align:start position:0% +and +what we'll find is that + + align:start position:0% +what we'll find is that + + + align:start position:0% +what we'll find is that +in the 2d world this is possible it's a + + align:start position:0% +in the 2d world this is possible it's a + + + align:start position:0% +in the 2d world this is possible it's a +little harder once you get to 3d so once + + align:start position:0% +little harder once you get to 3d so once + + + align:start position:0% +little harder once you get to 3d so once +we've done + + align:start position:0% +we've done + + + align:start position:0% +we've done +position and attitude in 2d + + align:start position:0% +position and attitude in 2d + + + align:start position:0% +position and attitude in 2d +we'll + + align:start position:0% +we'll + + + align:start position:0% +we'll +progress to 3d which is a more + + align:start position:0% +progress to 3d which is a more + + + align:start position:0% +progress to 3d which is a more +interesting problem but you know let's + + align:start position:0% +interesting problem but you know let's + + + align:start position:0% +interesting problem but you know let's +get some of the basics sorted out + + align:start position:0% +get some of the basics sorted out + + + align:start position:0% +get some of the basics sorted out +so i'll just sort of + + align:start position:0% +so i'll just sort of + + + align:start position:0% +so i'll just sort of +quickly + + align:start position:0% +quickly + + + align:start position:0% +quickly +review + + align:start position:0% +review + + + align:start position:0% +review +what this patent did + + align:start position:0% +what this patent did + + + align:start position:0% +what this patent did +and so + + align:start position:0% +and so + + + align:start position:0% +and so +we'll start so this is + + align:start position:0% + + + + align:start position:0% + +and the + + align:start position:0% +and the + + + align:start position:0% +and the +first idea was to look at the brightness + + align:start position:0% +first idea was to look at the brightness + + + align:start position:0% +first idea was to look at the brightness +gradient and so just a + + align:start position:0% +gradient and so just a + + + align:start position:0% +gradient and so just a +quick story on that so here we've got + + align:start position:0% +quick story on that so here we've got + + + align:start position:0% +quick story on that so here we've got +you know brightness as a function of x + + align:start position:0% +you know brightness as a function of x + + + align:start position:0% +you know brightness as a function of x +and + + align:start position:0% +and + + + align:start position:0% +and +there's a point where the curvature + + align:start position:0% +there's a point where the curvature + + + align:start position:0% +there's a point where the curvature +becomes zero and changes sign + + align:start position:0% +becomes zero and changes sign + + + align:start position:0% +becomes zero and changes sign +and that's called an inflection point + + align:start position:0% +and that's called an inflection point + + + align:start position:0% +and that's called an inflection point +and that's what we're looking for + + align:start position:0% +and that's what we're looking for + + + align:start position:0% +and that's what we're looking for +so the edge is actually spread out over + + align:start position:0% +so the edge is actually spread out over + + + align:start position:0% +so the edge is actually spread out over +several pixel but we're trying to + + align:start position:0% +several pixel but we're trying to + + + align:start position:0% +several pixel but we're trying to +identify very accurately a particular + + align:start position:0% +identify very accurately a particular + + + align:start position:0% +identify very accurately a particular +point on the edge + + align:start position:0% +point on the edge + + + align:start position:0% +point on the edge +then we looked at the derivative + + align:start position:0% +then we looked at the derivative + + + align:start position:0% +then we looked at the derivative +and there we're looking at a peak we're + + align:start position:0% +and there we're looking at a peak we're + + + align:start position:0% +and there we're looking at a peak we're +searching for a peak + + align:start position:0% +searching for a peak + + + align:start position:0% +searching for a peak +and + + align:start position:0% +and + + + align:start position:0% +and +some methods use second derivative + + align:start position:0% +some methods use second derivative + + + align:start position:0% +some methods use second derivative +and look for zero crossing + + align:start position:0% + + + + align:start position:0% + +but importantly this is + + align:start position:0% +but importantly this is + + + align:start position:0% +but importantly this is +in + + align:start position:0% +in + + + align:start position:0% +in +the gradient direction + + align:start position:0% + + + + align:start position:0% + +so this is of course a 1d cross section + + align:start position:0% +so this is of course a 1d cross section + + + align:start position:0% +so this is of course a 1d cross section +and we're dealing with images so + + align:start position:0% +and we're dealing with images so + + + align:start position:0% +and we're dealing with images so +how do we take the cross section well + + align:start position:0% +how do we take the cross section well + + + align:start position:0% +how do we take the cross section well +we're only interested in + + align:start position:0% +we're only interested in + + + align:start position:0% +we're only interested in +the direction that is perpendicular to + + align:start position:0% +the direction that is perpendicular to + + + align:start position:0% +the direction that is perpendicular to +the edge and so these graphs and these + + align:start position:0% +the edge and so these graphs and these + + + align:start position:0% +the edge and so these graphs and these +ideas correspond to that + + align:start position:0% +ideas correspond to that + + + align:start position:0% +ideas correspond to that +okay then + + align:start position:0% +okay then + + + align:start position:0% +okay then +we talked a little bit about + + align:start position:0% + + + + align:start position:0% + +things that are sometimes called + + align:start position:0% +things that are sometimes called + + + align:start position:0% +things that are sometimes called +stencils + + align:start position:0% +stencils + + + align:start position:0% +stencils +and sometimes called computational + + align:start position:0% +and sometimes called computational + + + align:start position:0% +and sometimes called computational +molecules + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +what we're trying to do is in the + + align:start position:0% +what we're trying to do is in the + + + align:start position:0% +what we're trying to do is in the +discrete world we're trying to estimate + + align:start position:0% +discrete world we're trying to estimate + + + align:start position:0% +discrete world we're trying to estimate +derivatives and so of course + + align:start position:0% +derivatives and so of course + + + align:start position:0% +derivatives and so of course +um you know there's some obvious ones + + align:start position:0% + + + + align:start position:0% + +so there's there's a way of getting an + + align:start position:0% +so there's there's a way of getting an + + + align:start position:0% +so there's there's a way of getting an +approximation for e sub x + + align:start position:0% + + + + align:start position:0% + +and here's another one + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% + + + + align:start position:0% + +these are all some of the ones that + + align:start position:0% +these are all some of the ones that + + + align:start position:0% +these are all some of the ones that +we already looked at + + align:start position:0% +we already looked at + + + align:start position:0% +we already looked at +so there are lots of ways of estimating + + align:start position:0% +so there are lots of ways of estimating + + + align:start position:0% +so there are lots of ways of estimating +the derivatives and how do we know which + + align:start position:0% +the derivatives and how do we know which + + + align:start position:0% +the derivatives and how do we know which +one to choose well uh their trade-offs + + align:start position:0% +one to choose well uh their trade-offs + + + align:start position:0% +one to choose well uh their trade-offs +and + + align:start position:0% +and + + + align:start position:0% +and +we + + align:start position:0% +we + + + align:start position:0% +we +saw that + + align:start position:0% +saw that + + + align:start position:0% +saw that +one way to + + align:start position:0% +one way to + + + align:start position:0% +one way to +progress is to + + align:start position:0% +progress is to + + + align:start position:0% +progress is to +use taylor series expansion to see what + + align:start position:0% +use taylor series expansion to see what + + + align:start position:0% +use taylor series expansion to see what +the lowest order error term is because + + align:start position:0% +the lowest order error term is because + + + align:start position:0% +the lowest order error term is because +we the higher we can push that if it's a + + align:start position:0% +we the higher we can push that if it's a + + + align:start position:0% +we the higher we can push that if it's a +third order error term uh it's better + + align:start position:0% +third order error term uh it's better + + + align:start position:0% +third order error term uh it's better +than if it was a second order error term + + align:start position:0% +than if it was a second order error term + + + align:start position:0% +than if it was a second order error term +and if two methods have the same order + + align:start position:0% +and if two methods have the same order + + + align:start position:0% +and if two methods have the same order +of error term then we look at the + + align:start position:0% +of error term then we look at the + + + align:start position:0% +of error term then we look at the +coefficient and if it's lower + + align:start position:0% +coefficient and if it's lower + + + align:start position:0% +coefficient and if it's lower +you know like like these two have the + + align:start position:0% +you know like like these two have the + + + align:start position:0% +you know like like these two have the +same uh + + align:start position:0% +same uh + + + align:start position:0% +same uh +lowest order error term and also what + + align:start position:0% +lowest order error term and also what + + + align:start position:0% +lowest order error term and also what +was very important was you know where + + align:start position:0% +was very important was you know where + + + align:start position:0% +was very important was you know where +are we trying to estimate the derivative + + align:start position:0% +are we trying to estimate the derivative + + + align:start position:0% +are we trying to estimate the derivative +and we decided that + + align:start position:0% +and we decided that + + + align:start position:0% +and we decided that +we get the best results + + align:start position:0% +we get the best results + + + align:start position:0% +we get the best results +at those particular points + + align:start position:0% +at those particular points + + + align:start position:0% +at those particular points +now some of those points are offset by + + align:start position:0% +now some of those points are offset by + + + align:start position:0% +now some of those points are offset by +half a pixel from the pixel grid and + + align:start position:0% +half a pixel from the pixel grid and + + + align:start position:0% +half a pixel from the pixel grid and +that's why people don't use them but + + align:start position:0% +that's why people don't use them but + + + align:start position:0% +that's why people don't use them but +that's silly because + + align:start position:0% +that's silly because + + + align:start position:0% +that's silly because +what's wrong with having some quantities + + align:start position:0% +what's wrong with having some quantities + + + align:start position:0% +what's wrong with having some quantities +on the pixel grid the image + + align:start position:0% +on the pixel grid the image + + + align:start position:0% +on the pixel grid the image +and some quantities on a grid that's + + align:start position:0% +and some quantities on a grid that's + + + align:start position:0% +and some quantities on a grid that's +offset by half as long as you know that + + align:start position:0% +offset by half as long as you know that + + + align:start position:0% +offset by half as long as you know that +it's offset by half you can + + align:start position:0% +it's offset by half you can + + + align:start position:0% +it's offset by half you can +translate any result on that grid into a + + align:start position:0% +translate any result on that grid into a + + + align:start position:0% +translate any result on that grid into a +result on the other group + + align:start position:0% +result on the other group + + + align:start position:0% +result on the other group +we can also analyze these in the fourier + + align:start position:0% +we can also analyze these in the fourier + + + align:start position:0% +we can also analyze these in the fourier +transform domain in terms of how they + + align:start position:0% +transform domain in terms of how they + + + align:start position:0% +transform domain in terms of how they +affect higher frequency content and + + align:start position:0% +affect higher frequency content and + + + align:start position:0% +affect higher frequency content and +we won't do that right now but + + align:start position:0% +we won't do that right now but + + + align:start position:0% +we won't do that right now but +that that's second + + align:start position:0% +that that's second + + + align:start position:0% +that that's second +set of methods we can use to + + align:start position:0% +set of methods we can use to + + + align:start position:0% +set of methods we can use to +decide which which of these is better + + align:start position:0% +decide which which of these is better + + + align:start position:0% +decide which which of these is better +now + + align:start position:0% +now + + + align:start position:0% +now +these derivative estimators can become + + align:start position:0% +these derivative estimators can become + + + align:start position:0% +these derivative estimators can become +quite complicated if you're looking for + + align:start position:0% +quite complicated if you're looking for + + + align:start position:0% +quite complicated if you're looking for +high precision so for example in in + + align:start position:0% +high precision so for example in in + + + align:start position:0% +high precision so for example in in +analyzing uh + + align:start position:0% +analyzing uh + + + align:start position:0% +analyzing uh +muscle electrical signals + + align:start position:0% +muscle electrical signals + + + align:start position:0% +muscle electrical signals +there's quite a bit of noise and there's + + align:start position:0% +there's quite a bit of noise and there's + + + align:start position:0% +there's quite a bit of noise and there's +quite a lot of + + align:start position:0% +quite a lot of + + + align:start position:0% +quite a lot of +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +distortion of the signal as it + + align:start position:0% +distortion of the signal as it + + + align:start position:0% +distortion of the signal as it +progresses through uh tissue + + align:start position:0% +progresses through uh tissue + + + align:start position:0% +progresses through uh tissue +and so you know when people are trying + + align:start position:0% +and so you know when people are trying + + + align:start position:0% +and so you know when people are trying +to estimate the first derivative they in + + align:start position:0% +to estimate the first derivative they in + + + align:start position:0% +to estimate the first derivative they in +one case one paper i saw use a 39 degree + + align:start position:0% +one case one paper i saw use a 39 degree + + + align:start position:0% +one case one paper i saw use a 39 degree +approximation so they use a pattern like + + align:start position:0% +approximation so they use a pattern like + + + align:start position:0% +approximation so they use a pattern like +this that's you know 39 + + align:start position:0% +this that's you know 39 + + + align:start position:0% +this that's you know 39 +elements long and + + align:start position:0% +elements long and + + + align:start position:0% +elements long and +they feel that that way they can control + + align:start position:0% +they feel that that way they can control + + + align:start position:0% +they feel that that way they can control +the trade-off between suppressing the + + align:start position:0% +the trade-off between suppressing the + + + align:start position:0% +the trade-off between suppressing the +noise and getting very accurate results + + align:start position:0% +noise and getting very accurate results + + + align:start position:0% +noise and getting very accurate results +so + + align:start position:0% +so + + + align:start position:0% +so +we're using very low order + + align:start position:0% +we're using very low order + + + align:start position:0% +we're using very low order +partly because + + align:start position:0% +partly because + + + align:start position:0% +partly because +you know it's easier and partly because + + align:start position:0% +you know it's easier and partly because + + + align:start position:0% +you know it's easier and partly because +one other trade-off is if you make them + + align:start position:0% +one other trade-off is if you make them + + + align:start position:0% +one other trade-off is if you make them +too long then they start to + + align:start position:0% +too long then they start to + + + align:start position:0% +too long then they start to +have different + + align:start position:0% +have different + + + align:start position:0% +have different +features interacting with each other so + + align:start position:0% +features interacting with each other so + + + align:start position:0% +features interacting with each other so +here we're trying to detect an edge now + + align:start position:0% +here we're trying to detect an edge now + + + align:start position:0% +here we're trying to detect an edge now +if you use an edge operator that's 100 + + align:start position:0% +if you use an edge operator that's 100 + + + align:start position:0% +if you use an edge operator that's 100 +pixels long and there's another edge + + align:start position:0% +pixels long and there's another edge + + + align:start position:0% +pixels long and there's another edge +within that 100 pixels it's going to + + align:start position:0% +within that 100 pixels it's going to + + + align:start position:0% +within that 100 pixels it's going to +interfere with the results so we we try + + align:start position:0% +interfere with the results so we we try + + + align:start position:0% +interfere with the results so we we try +to + + align:start position:0% +to + + + align:start position:0% +to +compromise on the one hand we get better + + align:start position:0% +compromise on the one hand we get better + + + align:start position:0% +compromise on the one hand we get better +results with bigger support + + align:start position:0% +results with bigger support + + + align:start position:0% +results with bigger support +better noise suppression but at the same + + align:start position:0% +better noise suppression but at the same + + + align:start position:0% +better noise suppression but at the same +time + + align:start position:0% +time + + + align:start position:0% +time +we run more into the problem of what + + align:start position:0% +we run more into the problem of what + + + align:start position:0% +we run more into the problem of what +happens when two edges get close to each + + align:start position:0% +happens when two edges get close to each + + + align:start position:0% +happens when two edges get close to each +other + + align:start position:0% +other + + + align:start position:0% +other +and in particular + + align:start position:0% +and in particular + + + align:start position:0% +and in particular +you know here's an image of the corner + + align:start position:0% +you know here's an image of the corner + + + align:start position:0% +you know here's an image of the corner +of a cube + + align:start position:0% +of a cube + + + align:start position:0% +of a cube +and yeah over here + + align:start position:0% +and yeah over here + + + align:start position:0% +and yeah over here +you know we can we could have + + align:start position:0% +you know we can we could have + + + align:start position:0% +you know we can we could have +potentially quite a large support but + + align:start position:0% +potentially quite a large support but + + + align:start position:0% +potentially quite a large support but +when we're back here + + align:start position:0% +when we're back here + + + align:start position:0% +when we're back here +edges get pretty close together and then + + align:start position:0% +edges get pretty close together and then + + + align:start position:0% +edges get pretty close together and then +a large support means that you're + + align:start position:0% +a large support means that you're + + + align:start position:0% +a large support means that you're +combining information about different + + align:start position:0% +combining information about different + + + align:start position:0% +combining information about different +edges and you won't get the results you + + align:start position:0% +edges and you won't get the results you + + + align:start position:0% +edges and you won't get the results you +you would like + + align:start position:0% +you would like + + + align:start position:0% +you would like +okay + + align:start position:0% +okay + + + align:start position:0% +okay +that's first derivative + + align:start position:0% + + + + align:start position:0% + +and if our model is we find the peak + + align:start position:0% +and if our model is we find the peak + + + align:start position:0% +and if our model is we find the peak +in the gradient direction of the first + + align:start position:0% +in the gradient direction of the first + + + align:start position:0% +in the gradient direction of the first +derivative then that's all we need but + + align:start position:0% +derivative then that's all we need but + + + align:start position:0% +derivative then that's all we need but +for some purposes we might want higher + + align:start position:0% +for some purposes we might want higher + + + align:start position:0% +for some purposes we might want higher +order derivatives + + align:start position:0% +order derivatives + + + align:start position:0% +order derivatives +and we'll see some examples of that + + align:start position:0% +and we'll see some examples of that + + + align:start position:0% +and we'll see some examples of that +later so + + align:start position:0% +later so + + + align:start position:0% +later so +now + + align:start position:0% + + + + align:start position:0% + +one way to think about this is that + + align:start position:0% + + + + align:start position:0% + +second derivative is just the first + + align:start position:0% +second derivative is just the first + + + align:start position:0% +second derivative is just the first +derivative applied twice + + align:start position:0% +derivative applied twice + + + align:start position:0% +derivative applied twice +and so we can run our numerical + + align:start position:0% +and so we can run our numerical + + + align:start position:0% +and so we can run our numerical +approximation + + align:start position:0% +approximation + + + align:start position:0% +approximation +a second time and that corresponds to + + align:start position:0% +a second time and that corresponds to + + + align:start position:0% +a second time and that corresponds to +convolution + + align:start position:0% + + + + align:start position:0% + +and the result is + + align:start position:0% + + + + align:start position:0% + +so that we can easily compute second + + align:start position:0% +so that we can easily compute second + + + align:start position:0% +so that we can easily compute second +order derivatives this way and let me + + align:start position:0% +order derivatives this way and let me + + + align:start position:0% +order derivatives this way and let me +just make sure we understand what this + + align:start position:0% +just make sure we understand what this + + + align:start position:0% +just make sure we understand what this +is so these computational molecules the + + align:start position:0% +is so these computational molecules the + + + align:start position:0% +is so these computational molecules the +way they work is that + + align:start position:0% +way they work is that + + + align:start position:0% +way they work is that +you put them down on the image grid and + + align:start position:0% +you put them down on the image grid and + + + align:start position:0% +you put them down on the image grid and +then you multiply the gray levels by + + align:start position:0% +then you multiply the gray levels by + + + align:start position:0% +then you multiply the gray levels by +whatever the weight is at this point so + + align:start position:0% +whatever the weight is at this point so + + + align:start position:0% +whatever the weight is at this point so +multiply that by one put it in + + align:start position:0% +multiply that by one put it in + + + align:start position:0% +multiply that by one put it in +accumulator take that one multiply it by + + align:start position:0% +accumulator take that one multiply it by + + + align:start position:0% +accumulator take that one multiply it by +-2 add that to the accumulator take that + + align:start position:0% +-2 add that to the accumulator take that + + + align:start position:0% +-2 add that to the accumulator take that +one multiply it by one add that to the + + align:start position:0% +one multiply it by one add that to the + + + align:start position:0% +one multiply it by one add that to the +accumulator and then finally take the + + align:start position:0% +accumulator and then finally take the + + + align:start position:0% +accumulator and then finally take the +result and divide by epsilon squared + + align:start position:0% +result and divide by epsilon squared + + + align:start position:0% +result and divide by epsilon squared +well often we don't care about constant + + align:start position:0% +well often we don't care about constant + + + align:start position:0% +well often we don't care about constant +factors so we might drop that but + + align:start position:0% +factors so we might drop that but + + + align:start position:0% +factors so we might drop that but +if we're actually thinking about + + align:start position:0% +if we're actually thinking about + + + align:start position:0% +if we're actually thinking about +derivatives we should we should do that + + align:start position:0% +derivatives we should we should do that + + + align:start position:0% +derivatives we should we should do that +so that's one thing + + align:start position:0% +so that's one thing + + + align:start position:0% +so that's one thing +and we're really talking about + + align:start position:0% +and we're really talking about + + + align:start position:0% +and we're really talking about +convolution + + align:start position:0% +convolution + + + align:start position:0% +convolution +right so we apply this to every place in + + align:start position:0% +right so we apply this to every place in + + + align:start position:0% +right so we apply this to every place in +the image + + align:start position:0% +the image + + + align:start position:0% +the image +slide it along if you like to produce a + + align:start position:0% +slide it along if you like to produce a + + + align:start position:0% +slide it along if you like to produce a +new image + + align:start position:0% +new image + + + align:start position:0% +new image +results at a bunch of points + + align:start position:0% +results at a bunch of points + + + align:start position:0% +results at a bunch of points +now + + align:start position:0% +now + + + align:start position:0% +now +how do we know that + + align:start position:0% +how do we know that + + + align:start position:0% +how do we know that +you know if we want a sanity check well + + align:start position:0% +you know if we want a sanity check well + + + align:start position:0% +you know if we want a sanity check well +a way of making + + align:start position:0% +a way of making + + + align:start position:0% +a way of making +this + + align:start position:0% + + + + align:start position:0% + +making a check on this is to + + align:start position:0% +making a check on this is to + + + align:start position:0% +making a check on this is to +try it on some function where you know + + align:start position:0% +try it on some function where you know + + + align:start position:0% +try it on some function where you know +what the answer is + + align:start position:0% +what the answer is + + + align:start position:0% +what the answer is +so + + align:start position:0% + + + + align:start position:0% + +right so we know that in this case uh + + align:start position:0% +right so we know that in this case uh + + + align:start position:0% +right so we know that in this case uh +the answer should be 2. so so let's + + align:start position:0% +the answer should be 2. so so let's + + + align:start position:0% +the answer should be 2. so so let's +apply this + + align:start position:0% +apply this + + + align:start position:0% +apply this +and well we have to decide where we're + + align:start position:0% +and well we have to decide where we're + + + align:start position:0% +and well we have to decide where we're +applying it so let's suppose that this + + align:start position:0% +applying it so let's suppose that this + + + align:start position:0% +applying it so let's suppose that this +is uh + + align:start position:0% +is uh + + + align:start position:0% +is uh +zero this is one this is minus one + + align:start position:0% +zero this is one this is minus one + + + align:start position:0% +zero this is one this is minus one +so we're plunking this down + + align:start position:0% +so we're plunking this down + + + align:start position:0% +so we're plunking this down +and so what do we get well uh in this + + align:start position:0% +and so what do we get well uh in this + + + align:start position:0% +and so what do we get well uh in this +case epsilon is obviously one so that's + + align:start position:0% +case epsilon is obviously one so that's + + + align:start position:0% +case epsilon is obviously one so that's +one + + align:start position:0% +one + + + align:start position:0% +one +times and then 1 times + + align:start position:0% +times and then 1 times + + + align:start position:0% +times and then 1 times +-1 well that's 2 + + align:start position:0% +-1 well that's 2 + + + align:start position:0% +-1 well that's 2 +no sorry 1 times + + align:start position:0% +no sorry 1 times + + + align:start position:0% +no sorry 1 times +yeah + + align:start position:0% + + + + align:start position:0% + +1 times -1 squared is 1. then we have + + align:start position:0% +1 times -1 squared is 1. then we have + + + align:start position:0% +1 times -1 squared is 1. then we have +minus 2 times x squared with 0 + + align:start position:0% +minus 2 times x squared with 0 + + + align:start position:0% +minus 2 times x squared with 0 +and plus 1 + + align:start position:0% +and plus 1 + + + align:start position:0% +and plus 1 +times 1 squared and so that's + + align:start position:0% + + + + align:start position:0% + +2. + + align:start position:0% +2. + + + align:start position:0% +2. +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so apparently it works + + align:start position:0% +so apparently it works + + + align:start position:0% +so apparently it works +so + + align:start position:0% +so + + + align:start position:0% +so +you know the different ways of designing + + align:start position:0% +you know the different ways of designing + + + align:start position:0% +you know the different ways of designing +these computational molecules + + align:start position:0% +these computational molecules + + + align:start position:0% +these computational molecules +um + + align:start position:0% +um + + + align:start position:0% +um +certainly convolution is one and then + + align:start position:0% +certainly convolution is one and then + + + align:start position:0% +certainly convolution is one and then +you'd want to check them so the another + + align:start position:0% +you'd want to check them so the another + + + align:start position:0% +you'd want to check them so the another +thing you might want to check is well + + align:start position:0% +thing you might want to check is well + + + align:start position:0% +thing you might want to check is well +what if f of x is x + + align:start position:0% +what if f of x is x + + + align:start position:0% +what if f of x is x +uh okay well then we're going to get + + align:start position:0% +uh okay well then we're going to get + + + align:start position:0% +uh okay well then we're going to get +1 times -1 + + align:start position:0% +1 times -1 + + + align:start position:0% +1 times -1 + + align:start position:0% + + + align:start position:0% +1 times 1 the answer is 0 which is what + + align:start position:0% +1 times 1 the answer is 0 which is what + + + align:start position:0% +1 times 1 the answer is 0 which is what +it should be right + + align:start position:0% + + + + align:start position:0% + +what if f of x is one + + align:start position:0% +what if f of x is one + + + align:start position:0% +what if f of x is one +so you want to check it for + + align:start position:0% +so you want to check it for + + + align:start position:0% +so you want to check it for +polynomials of low order up to the order + + align:start position:0% +polynomials of low order up to the order + + + align:start position:0% +polynomials of low order up to the order +of the derivative you're trying to get + + align:start position:0% +of the derivative you're trying to get + + + align:start position:0% +of the derivative you're trying to get +so if f of x is one then of course we + + align:start position:0% +so if f of x is one then of course we + + + align:start position:0% +so if f of x is one then of course we +get one minus two plus one is zero which + + align:start position:0% +get one minus two plus one is zero which + + + align:start position:0% +get one minus two plus one is zero which +is again what what you what it should be + + align:start position:0% +is again what what you what it should be + + + align:start position:0% +is again what what you what it should be +because the second derivative is zero + + align:start position:0% +because the second derivative is zero + + + align:start position:0% +because the second derivative is zero +so one of the constraints on these + + align:start position:0% +so one of the constraints on these + + + align:start position:0% +so one of the constraints on these +operators if they're supposed to be + + align:start position:0% +operators if they're supposed to be + + + align:start position:0% +operators if they're supposed to be +derivative operators is that the weights + + align:start position:0% +derivative operators is that the weights + + + align:start position:0% +derivative operators is that the weights +add up to zero + + align:start position:0% +add up to zero + + + align:start position:0% +add up to zero +that makes sense + + align:start position:0% +that makes sense + + + align:start position:0% +that makes sense +okay uh well so that's just one uh + + align:start position:0% +okay uh well so that's just one uh + + + align:start position:0% +okay uh well so that's just one uh +one dimension so to speak what about + + align:start position:0% +one dimension so to speak what about + + + align:start position:0% +one dimension so to speak what about +d2 dxdy + + align:start position:0% + + + + align:start position:0% + +we can just do that and so + + align:start position:0% + + + + align:start position:0% + +right so because + + align:start position:0% +right so because + + + align:start position:0% +right so because +this is + + align:start position:0% +this is + + + align:start position:0% +this is +the x derivative and that's the y + + align:start position:0% +the x derivative and that's the y + + + align:start position:0% +the x derivative and that's the y +derivative and uh composition of + + align:start position:0% +derivative and uh composition of + + + align:start position:0% +derivative and uh composition of +differentiation + + align:start position:0% +differentiation + + + align:start position:0% +differentiation +corresponds to convolution so that's a + + align:start position:0% +corresponds to convolution so that's a + + + align:start position:0% +corresponds to convolution so that's a +we're kind of sneaking in some stuff + + align:start position:0% +we're kind of sneaking in some stuff + + + align:start position:0% +we're kind of sneaking in some stuff +here one of them is that you know uh + + align:start position:0% +here one of them is that you know uh + + + align:start position:0% +here one of them is that you know uh +we're used to dealing with linear shift + + align:start position:0% +we're used to dealing with linear shift + + + align:start position:0% +we're used to dealing with linear shift +invariant systems but it turns out that + + align:start position:0% +invariant systems but it turns out that + + + align:start position:0% +invariant systems but it turns out that +of course derivative operations are + + align:start position:0% +of course derivative operations are + + + align:start position:0% +of course derivative operations are +linear shift invariant in that if i take + + align:start position:0% +linear shift invariant in that if i take + + + align:start position:0% +linear shift invariant in that if i take +the derivative of a function + + align:start position:0% +the derivative of a function + + + align:start position:0% +the derivative of a function +and then take the derivative of the same + + align:start position:0% +and then take the derivative of the same + + + align:start position:0% +and then take the derivative of the same +function shifted what i'm going to get + + align:start position:0% +function shifted what i'm going to get + + + align:start position:0% +function shifted what i'm going to get +is the derivative shifted right + + align:start position:0% +is the derivative shifted right + + + align:start position:0% +is the derivative shifted right +if i take the derivative of the sum of + + align:start position:0% +if i take the derivative of the sum of + + + align:start position:0% +if i take the derivative of the sum of +two functions i'm going to get the sum + + align:start position:0% +two functions i'm going to get the sum + + + align:start position:0% +two functions i'm going to get the sum +of the derivatives so + + align:start position:0% +of the derivatives so + + + align:start position:0% +of the derivatives so +that's a very important thing to + + align:start position:0% +that's a very important thing to + + + align:start position:0% +that's a very important thing to +exploit + + align:start position:0% +exploit + + + align:start position:0% +exploit +is that um you know derivatives taking + + align:start position:0% +is that um you know derivatives taking + + + align:start position:0% +is that um you know derivatives taking +derivatives can be considered + + align:start position:0% +derivatives can be considered + + + align:start position:0% +derivatives can be considered +convolution and so all of the good stuff + + align:start position:0% +convolution and so all of the good stuff + + + align:start position:0% +convolution and so all of the good stuff +we know about that applies + + align:start position:0% +we know about that applies + + + align:start position:0% +we know about that applies +so let's see what this gives us + + align:start position:0% +so let's see what this gives us + + + align:start position:0% +so let's see what this gives us +now + + align:start position:0% +now + + + align:start position:0% +now +um uh what we're going to do basically + + align:start position:0% +um uh what we're going to do basically + + + align:start position:0% +um uh what we're going to do basically +is take one of these + + align:start position:0% +is take one of these + + + align:start position:0% +is take one of these +and uh + + align:start position:0% +and uh + + + align:start position:0% +and uh +flip it and superimpose it on the other + + align:start position:0% +flip it and superimpose it on the other + + + align:start position:0% +flip it and superimpose it on the other +one + + align:start position:0% +one + + + align:start position:0% +one +and + + align:start position:0% +and + + + align:start position:0% +and +if i superimpose it over here of course + + align:start position:0% +if i superimpose it over here of course + + + align:start position:0% +if i superimpose it over here of course +i get zero because + + align:start position:0% +i get zero because + + + align:start position:0% +i get zero because +i'm multiplying + + align:start position:0% +i'm multiplying + + + align:start position:0% +i'm multiplying +you know we assume the background is + + align:start position:0% +you know we assume the background is + + + align:start position:0% +you know we assume the background is +zero we assume that the only values + + align:start position:0% +zero we assume that the only values + + + align:start position:0% +zero we assume that the only values +we're showing are the non-zero values + + align:start position:0% +we're showing are the non-zero values + + + align:start position:0% +we're showing are the non-zero values +okay but then what if i move it here + + align:start position:0% +okay but then what if i move it here + + + align:start position:0% +okay but then what if i move it here +well then there's an overlap + + align:start position:0% + + + + align:start position:0% + +and then i move it over there there's an + + align:start position:0% +and then i move it over there there's an + + + align:start position:0% +and then i move it over there there's an +overlap and i can move it down here + + align:start position:0% +overlap and i can move it down here + + + align:start position:0% +overlap and i can move it down here +there's an overlap and i move it down + + align:start position:0% +there's an overlap and i move it down + + + align:start position:0% +there's an overlap and i move it down +here and again so i expect to get + + align:start position:0% +here and again so i expect to get + + + align:start position:0% +here and again so i expect to get +four values + + align:start position:0% +four values + + + align:start position:0% +four values +out of this convolution and so + + align:start position:0% +out of this convolution and so + + + align:start position:0% +out of this convolution and so +i'm going to get something like this + + align:start position:0% + + + + align:start position:0% + +and so my 2 by 2 stencil for estimating + + align:start position:0% +and so my 2 by 2 stencil for estimating + + + align:start position:0% +and so my 2 by 2 stencil for estimating +the mixed derivative is is just that and + + align:start position:0% +the mixed derivative is is just that and + + + align:start position:0% +the mixed derivative is is just that and +it makes perfect sense one thing to + + align:start position:0% +it makes perfect sense one thing to + + + align:start position:0% +it makes perfect sense one thing to +watch out for is that + + align:start position:0% +watch out for is that + + + align:start position:0% +watch out for is that +in convolution + + align:start position:0% +in convolution + + + align:start position:0% +in convolution +you know we flip one of the two + + align:start position:0% +you know we flip one of the two + + + align:start position:0% +you know we flip one of the two +functions + + align:start position:0% +functions + + + align:start position:0% +functions +and uh then then slide it across and try + + align:start position:0% +and uh then then slide it across and try + + + align:start position:0% +and uh then then slide it across and try +it in all possible places uh over here + + align:start position:0% +it in all possible places uh over here + + + align:start position:0% +it in all possible places uh over here +sometimes we're + + align:start position:0% +sometimes we're + + + align:start position:0% +sometimes we're +using computational stencils that are + + align:start position:0% +using computational stencils that are + + + align:start position:0% +using computational stencils that are +not flipped + + align:start position:0% +not flipped + + + align:start position:0% +not flipped +so + + align:start position:0% +so + + + align:start position:0% +so +we may end up with some sign reversal + + align:start position:0% +we may end up with some sign reversal + + + align:start position:0% +we may end up with some sign reversal +but you want to + + align:start position:0% +but you want to + + + align:start position:0% +but you want to +you can always check + + align:start position:0% +you can always check + + + align:start position:0% +you can always check +on a simple polynomial to see whether + + align:start position:0% +on a simple polynomial to see whether + + + align:start position:0% +on a simple polynomial to see whether +it's working the right way around + + align:start position:0% + + + + align:start position:0% + +by the way this one here + + align:start position:0% +by the way this one here + + + align:start position:0% +by the way this one here +we can sort of take a diagonal view of + + align:start position:0% +we can sort of take a diagonal view of + + + align:start position:0% +we can sort of take a diagonal view of +this + + align:start position:0% +this + + + align:start position:0% +this +it's a little bit like + + align:start position:0% +it's a little bit like + + + align:start position:0% +it's a little bit like +right if i project this down + + align:start position:0% +right if i project this down + + + align:start position:0% +right if i project this down +so there's a plus one far out on this + + align:start position:0% +so there's a plus one far out on this + + + align:start position:0% +so there's a plus one far out on this +side there's a plus one far out on that + + align:start position:0% +side there's a plus one far out on that + + + align:start position:0% +side there's a plus one far out on that +side and then there's a minus + + align:start position:0% +side and then there's a minus + + + align:start position:0% +side and then there's a minus +two there two minus ones in the middle + + align:start position:0% +two there two minus ones in the middle + + + align:start position:0% +two there two minus ones in the middle +and + + align:start position:0% +and + + + align:start position:0% +and +this looks awfully like a second + + align:start position:0% +this looks awfully like a second + + + align:start position:0% +this looks awfully like a second +derivative uh you know like the one + + align:start position:0% +derivative uh you know like the one + + + align:start position:0% +derivative uh you know like the one +we had over here just rotated 45 degrees + + align:start position:0% +we had over here just rotated 45 degrees + + + align:start position:0% +we had over here just rotated 45 degrees +and of course + + align:start position:0% +and of course + + + align:start position:0% +and of course +this mixed partial derivative + + align:start position:0% +this mixed partial derivative + + + align:start position:0% +this mixed partial derivative +is + + align:start position:0% +is + + + align:start position:0% +is +uh in a rotated coordinate system just + + align:start position:0% +uh in a rotated coordinate system just + + + align:start position:0% +uh in a rotated coordinate system just +d2 dx squared + + align:start position:0% +d2 dx squared + + + align:start position:0% +d2 dx squared +right so if i take + + align:start position:0% + + + + align:start position:0% + +so this is my original + + align:start position:0% +so this is my original + + + align:start position:0% +so this is my original +coordinate system and then i look at the + + align:start position:0% +coordinate system and then i look at the + + + align:start position:0% +coordinate system and then i look at the +world in this coordinate system + + align:start position:0% + + + + align:start position:0% + +then the second derivative + + align:start position:0% +then the second derivative + + + align:start position:0% +then the second derivative +e x prime x prime + + align:start position:0% +e x prime x prime + + + align:start position:0% +e x prime x prime +is the same as + + align:start position:0% +is the same as + + + align:start position:0% +is the same as +that mixed derivative + + align:start position:0% +that mixed derivative + + + align:start position:0% +that mixed derivative +so you know we kind of think of e x y as + + align:start position:0% +so you know we kind of think of e x y as + + + align:start position:0% +so you know we kind of think of e x y as +a very different animal from e x + + align:start position:0% +a very different animal from e x + + + align:start position:0% +a very different animal from e x +x and e y y but but it isn't + + align:start position:0% +x and e y y but but it isn't + + + align:start position:0% +x and e y y but but it isn't +oh yeah just a little bit more of this + + align:start position:0% +oh yeah just a little bit more of this + + + align:start position:0% +oh yeah just a little bit more of this +before we go on um + + align:start position:0% +before we go on um + + + align:start position:0% +before we go on um +so + + align:start position:0% +so + + + align:start position:0% +so +and we already mentioned the laplacian + + align:start position:0% +and we already mentioned the laplacian + + + align:start position:0% +and we already mentioned the laplacian +let's just bring that in here again + + align:start position:0% + + + + align:start position:0% + +so we had a second derivative operator + + align:start position:0% +so we had a second derivative operator + + + align:start position:0% +so we had a second derivative operator +here + + align:start position:0% +here + + + align:start position:0% +here +and so in the case of the laplacian + + align:start position:0% +and so in the case of the laplacian + + + align:start position:0% +and so in the case of the laplacian +we're adding two of them in different in + + align:start position:0% +we're adding two of them in different in + + + align:start position:0% +we're adding two of them in different in +orthogonal directions + + align:start position:0% +orthogonal directions + + + align:start position:0% +orthogonal directions +so we could just do + + align:start position:0% + + + + align:start position:0% + +right so that's just this thing + + align:start position:0% +right so that's just this thing + + + align:start position:0% +right so that's just this thing +plus + + align:start position:0% +plus + + + align:start position:0% +plus +it the same thing rotated 90 degrees and + + align:start position:0% +it the same thing rotated 90 degrees and + + + align:start position:0% +it the same thing rotated 90 degrees and +so so that's one way of writing the + + align:start position:0% +so so that's one way of writing the + + + align:start position:0% +so so that's one way of writing the +laplacian + + align:start position:0% + + + + align:start position:0% + +but + + align:start position:0% + + + + align:start position:0% + +that turns out to um also be a good + + align:start position:0% +that turns out to um also be a good + + + align:start position:0% +that turns out to um also be a good +approximation uh to the laplacian how do + + align:start position:0% +approximation uh to the laplacian how do + + + align:start position:0% +approximation uh to the laplacian how do +i know well there are lots of ways of + + align:start position:0% +i know well there are lots of ways of + + + align:start position:0% +i know well there are lots of ways of +checking one is + + align:start position:0% +checking one is + + + align:start position:0% +checking one is +taylor series + + align:start position:0% +taylor series + + + align:start position:0% +taylor series +another way is apply it to test + + align:start position:0% +another way is apply it to test + + + align:start position:0% +another way is apply it to test +functions + + align:start position:0% +functions + + + align:start position:0% +functions +see if it gets the right result and + + align:start position:0% +see if it gets the right result and + + + align:start position:0% +see if it gets the right result and +another way is fourier transform but + + align:start position:0% +another way is fourier transform but + + + align:start position:0% +another way is fourier transform but +you know those and and you'll see that + + align:start position:0% +you know those and and you'll see that + + + align:start position:0% +you know those and and you'll see that +this is really the same pattern rotated + + align:start position:0% +this is really the same pattern rotated + + + align:start position:0% +this is really the same pattern rotated +45 degrees + + align:start position:0% +45 degrees + + + align:start position:0% +45 degrees +but + + align:start position:0% +but + + + align:start position:0% +but +now the separation is square root of two + + align:start position:0% +now the separation is square root of two + + + align:start position:0% +now the separation is square root of two +times as large + + align:start position:0% +times as large + + + align:start position:0% +times as large +so i end up having to change the the + + align:start position:0% +so i end up having to change the the + + + align:start position:0% +so i end up having to change the the +weight + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +now i mentioned that the laplacian is + + align:start position:0% +now i mentioned that the laplacian is + + + align:start position:0% +now i mentioned that the laplacian is +the lowest order linear differential + + align:start position:0% +the lowest order linear differential + + + align:start position:0% +the lowest order linear differential +operator that's rotationally symmetric + + align:start position:0% +operator that's rotationally symmetric + + + align:start position:0% +operator that's rotationally symmetric +well neither of these looks particularly + + align:start position:0% +well neither of these looks particularly + + + align:start position:0% +well neither of these looks particularly +rotationally symmetric so + + align:start position:0% +rotationally symmetric so + + + align:start position:0% +rotationally symmetric so +can we make one that's a bit more i mean + + align:start position:0% +can we make one that's a bit more i mean + + + align:start position:0% +can we make one that's a bit more i mean +on a square grid + + align:start position:0% +on a square grid + + + align:start position:0% +on a square grid +you can't but we can do better than + + align:start position:0% +you can't but we can do better than + + + align:start position:0% +you can't but we can do better than +these and one way is to combine them to + + align:start position:0% +these and one way is to combine them to + + + align:start position:0% +these and one way is to combine them to +take a weighted sum of these two + + align:start position:0% + + + + align:start position:0% + +okay so i've taken uh + + align:start position:0% +okay so i've taken uh + + + align:start position:0% +okay so i've taken uh +i don't know four times this one + + align:start position:0% +i don't know four times this one + + + align:start position:0% +i don't know four times this one +plus one times uh this one + + align:start position:0% +plus one times uh this one + + + align:start position:0% +plus one times uh this one +and and i get this operator and it's a + + align:start position:0% +and and i get this operator and it's a + + + align:start position:0% +and and i get this operator and it's a +little bit smoother in terms of + + align:start position:0% +little bit smoother in terms of + + + align:start position:0% +little bit smoother in terms of +rotational symmetry uh the the corner + + align:start position:0% +rotational symmetry uh the the corner + + + align:start position:0% +rotational symmetry uh the the corner +ones aren't zero + + align:start position:0% +ones aren't zero + + + align:start position:0% +ones aren't zero +uh but they also don't have the same + + align:start position:0% +uh but they also don't have the same + + + align:start position:0% +uh but they also don't have the same +weight as the diagonal one the the up + + align:start position:0% +weight as the diagonal one the the up + + + align:start position:0% +weight as the diagonal one the the up +and down ones um + + align:start position:0% +and down ones um + + + align:start position:0% +and down ones um +because they're further from the center + + align:start position:0% +because they're further from the center + + + align:start position:0% +because they're further from the center +so how do i know that's a good + + align:start position:0% +so how do i know that's a good + + + align:start position:0% +so how do i know that's a good +combination + + align:start position:0% +combination + + + align:start position:0% +combination +how did people get to that one well + + align:start position:0% +how did people get to that one well + + + align:start position:0% +how did people get to that one well +again you look at the taylor series and + + align:start position:0% +again you look at the taylor series and + + + align:start position:0% +again you look at the taylor series and +it turns out that the lowest order error + + align:start position:0% +it turns out that the lowest order error + + + align:start position:0% +it turns out that the lowest order error +term for this one is one larger than the + + align:start position:0% +term for this one is one larger than the + + + align:start position:0% +term for this one is one larger than the +lowest order error term for either of + + align:start position:0% +lowest order error term for either of + + + align:start position:0% +lowest order error term for either of +these two + + align:start position:0% +these two + + + align:start position:0% +these two +so + + align:start position:0% +so + + + align:start position:0% +so +it's better uh + + align:start position:0% +it's better uh + + + align:start position:0% +it's better uh +more work right if you do if you apply + + align:start position:0% +more work right if you do if you apply + + + align:start position:0% +more work right if you do if you apply +this to your image + + align:start position:0% +this to your image + + + align:start position:0% +this to your image +uh you're doing + + align:start position:0% +uh you're doing + + + align:start position:0% +uh you're doing +not quite twice as much work but you're + + align:start position:0% +not quite twice as much work but you're + + + align:start position:0% +not quite twice as much work but you're +doing more work because you have to take + + align:start position:0% +doing more work because you have to take + + + align:start position:0% +doing more work because you have to take +into account all of the corner ones + + align:start position:0% +into account all of the corner ones + + + align:start position:0% +into account all of the corner ones +which this this operator doesn't or + + align:start position:0% +which this this operator doesn't or + + + align:start position:0% +which this this operator doesn't or +conversely the up and down and west and + + align:start position:0% +conversely the up and down and west and + + + align:start position:0% +conversely the up and down and west and +east ones uh there so + + align:start position:0% +east ones uh there so + + + align:start position:0% +east ones uh there so +and + + align:start position:0% +and + + + align:start position:0% +and +you know if we wanted to we could do a + + align:start position:0% +you know if we wanted to we could do a + + + align:start position:0% +you know if we wanted to we could do a +more detailed analysis of the error + + align:start position:0% +more detailed analysis of the error + + + align:start position:0% +more detailed analysis of the error +terms but + + align:start position:0% +terms but + + + align:start position:0% +terms but +that's that's pretty boring so we won't + + align:start position:0% +that's that's pretty boring so we won't + + + align:start position:0% +that's that's pretty boring so we won't +do that anyway so those are + + align:start position:0% +do that anyway so those are + + + align:start position:0% +do that anyway so those are +kind of all of the computational + + align:start position:0% +kind of all of the computational + + + align:start position:0% +kind of all of the computational +molecules we're going to need and as you + + align:start position:0% +molecules we're going to need and as you + + + align:start position:0% +molecules we're going to need and as you +can see the the options the the + + align:start position:0% +can see the the options the the + + + align:start position:0% +can see the the options the the +different versions + + align:start position:0% +different versions + + + align:start position:0% +different versions +uh that are trying to compute the same + + align:start position:0% +uh that are trying to compute the same + + + align:start position:0% +uh that are trying to compute the same +sort of thing of course on a hexagonal + + align:start position:0% +sort of thing of course on a hexagonal + + + align:start position:0% +sort of thing of course on a hexagonal +grid + + align:start position:0% +grid + + + align:start position:0% +grid +this looks much better + + align:start position:0% +this looks much better + + + align:start position:0% +this looks much better +because we can + + align:start position:0% + + + + align:start position:0% + +we can do something like this + + align:start position:0% + + + + align:start position:0% + +which uh you know looks nice and + + align:start position:0% +which uh you know looks nice and + + + align:start position:0% +which uh you know looks nice and +rotationally symmetric yeah what's the + + align:start position:0% +rotationally symmetric yeah what's the + + + align:start position:0% +rotationally symmetric yeah what's the +one in the middle + + align:start position:0% +one in the middle + + + align:start position:0% +one in the middle +oh + + align:start position:0% +oh + + + align:start position:0% +oh +-20 so so can anyone think of how you + + align:start position:0% +-20 so so can anyone think of how you + + + align:start position:0% +-20 so so can anyone think of how you +could determine that it should be minus + + align:start position:0% +could determine that it should be minus + + + align:start position:0% +could determine that it should be minus +20 without actually doing a lot of area + + align:start position:0% +20 without actually doing a lot of area + + + align:start position:0% +20 without actually doing a lot of area +algebra + + align:start position:0% +algebra + + + align:start position:0% +algebra +they have to sum to zero right why is + + align:start position:0% +they have to sum to zero right why is + + + align:start position:0% +they have to sum to zero right why is +that well because when you apply this + + align:start position:0% +that well because when you apply this + + + align:start position:0% +that well because when you apply this +operator to f of x equals one + + align:start position:0% +operator to f of x equals one + + + align:start position:0% +operator to f of x equals one +the + + align:start position:0% +the + + + align:start position:0% +the +laplacian is zero and so if you apply + + align:start position:0% +laplacian is zero and so if you apply + + + align:start position:0% +laplacian is zero and so if you apply +this to the function that's one + + align:start position:0% +this to the function that's one + + + align:start position:0% +this to the function that's one +everywhere obviously you'll just be + + align:start position:0% +everywhere obviously you'll just be + + + align:start position:0% +everywhere obviously you'll just be +adding all the weights and so they they + + align:start position:0% +adding all the weights and so they they + + + align:start position:0% +adding all the weights and so they they +need to add how do i know it's one over + + align:start position:0% +need to add how do i know it's one over + + + align:start position:0% +need to add how do i know it's one over + + align:start position:0% + + + align:start position:0% +well one way to get it is is to apply + + align:start position:0% +well one way to get it is is to apply + + + align:start position:0% +well one way to get it is is to apply +this to a test function like you know if + + align:start position:0% +this to a test function like you know if + + + align:start position:0% +this to a test function like you know if +f of x is x squared plus y squared where + + align:start position:0% +f of x is x squared plus y squared where + + + align:start position:0% +f of x is x squared plus y squared where +i know that the answer is + + align:start position:0% +i know that the answer is + + + align:start position:0% +i know that the answer is + + align:start position:0% + + + align:start position:0% +and then you know + + align:start position:0% +and then you know + + + align:start position:0% +and then you know +go from there + + align:start position:0% +go from there + + + align:start position:0% +go from there +or i can get it from this argument which + + align:start position:0% +or i can get it from this argument which + + + align:start position:0% +or i can get it from this argument which +is the weighted argument that i'm taking + + align:start position:0% +is the weighted argument that i'm taking + + + align:start position:0% +is the weighted argument that i'm taking +uh + + align:start position:0% +uh + + + align:start position:0% +uh +four times one of those and one of those + + align:start position:0% +four times one of those and one of those + + + align:start position:0% +four times one of those and one of those +and this one has a factor of 2 in there + + align:start position:0% +and this one has a factor of 2 in there + + + align:start position:0% +and this one has a factor of 2 in there +so you end up with + + align:start position:0% +so you end up with + + + align:start position:0% +so you end up with +i don't know + + align:start position:0% +i don't know + + + align:start position:0% +i don't know +a half plus a + + align:start position:0% +a half plus a + + + align:start position:0% +a half plus a +quarter no + + align:start position:0% +quarter no + + + align:start position:0% +quarter no +anyway it comes out to 6 epsilon squared + + align:start position:0% +anyway it comes out to 6 epsilon squared + + + align:start position:0% +anyway it comes out to 6 epsilon squared +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so + + align:start position:0% + + + + align:start position:0% + +so it's sort of annoying that + + align:start position:0% +so it's sort of annoying that + + + align:start position:0% +so it's sort of annoying that +we don't have hexagonal pixels + + align:start position:0% +we don't have hexagonal pixels + + + align:start position:0% +we don't have hexagonal pixels +by the way there are some situations + + align:start position:0% +by the way there are some situations + + + align:start position:0% +by the way there are some situations +where people are + + align:start position:0% +where people are + + + align:start position:0% +where people are +very concerned about + + align:start position:0% +very concerned about + + + align:start position:0% +very concerned about +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +you know efficiency + + align:start position:0% +you know efficiency + + + align:start position:0% +you know efficiency +you know like trying to image the black + + align:start position:0% +you know like trying to image the black + + + align:start position:0% +you know like trying to image the black +hole at the center of our galaxy using + + align:start position:0% +hole at the center of our galaxy using + + + align:start position:0% +hole at the center of our galaxy using +using + + align:start position:0% +using + + + align:start position:0% +using +radio frequencies + + align:start position:0% +radio frequencies + + + align:start position:0% +radio frequencies +by you and you know each antenna you put + + align:start position:0% +by you and you know each antenna you put + + + align:start position:0% +by you and you know each antenna you put +up costs a pile of money so you want to + + align:start position:0% +up costs a pile of money so you want to + + + align:start position:0% +up costs a pile of money so you want to +make sure that this grid of antennas is + + align:start position:0% +make sure that this grid of antennas is + + + align:start position:0% +make sure that this grid of antennas is +the most efficient way of sampling the + + align:start position:0% +the most efficient way of sampling the + + + align:start position:0% +the most efficient way of sampling the +fourier transform space in that case and + + align:start position:0% +fourier transform space in that case and + + + align:start position:0% +fourier transform space in that case and +so it turns out that this way of + + align:start position:0% +so it turns out that this way of + + + align:start position:0% +so it turns out that this way of +sampling + + align:start position:0% +sampling + + + align:start position:0% +sampling +is four over pi as efficient as that way + + align:start position:0% +is four over pi as efficient as that way + + + align:start position:0% +is four over pi as efficient as that way +of sampling so there are places where + + align:start position:0% +of sampling so there are places where + + + align:start position:0% +of sampling so there are places where +people do this and and for example + + align:start position:0% +people do this and and for example + + + align:start position:0% +people do this and and for example +briefly in + + align:start position:0% +briefly in + + + align:start position:0% +briefly in +you know almost all chips are laid out + + align:start position:0% +you know almost all chips are laid out + + + align:start position:0% +you know almost all chips are laid out +on a rectangular pattern + + align:start position:0% +on a rectangular pattern + + + align:start position:0% +on a rectangular pattern +because that's very easy to do and check + + align:start position:0% +because that's very easy to do and check + + + align:start position:0% +because that's very easy to do and check +but if it comes down to packing density + + align:start position:0% +but if it comes down to packing density + + + align:start position:0% +but if it comes down to packing density +and you know particularly if you have + + align:start position:0% +and you know particularly if you have + + + align:start position:0% +and you know particularly if you have +something that has a very simple + + align:start position:0% +something that has a very simple + + + align:start position:0% +something that has a very simple +repeating pattern then sometimes there's + + align:start position:0% +repeating pattern then sometimes there's + + + align:start position:0% +repeating pattern then sometimes there's +an advantage so there were memory chips + + align:start position:0% +an advantage so there were memory chips + + + align:start position:0% +an advantage so there were memory chips +for a while that used the hexagonal + + align:start position:0% +for a while that used the hexagonal + + + align:start position:0% +for a while that used the hexagonal +layout but they've since disappeared + + align:start position:0% +layout but they've since disappeared + + + align:start position:0% +layout but they've since disappeared +because now we're stacking things + + align:start position:0% +because now we're stacking things + + + align:start position:0% +because now we're stacking things +vertically and right now it doesn't seem + + align:start position:0% +vertically and right now it doesn't seem + + + align:start position:0% +vertically and right now it doesn't seem +to be an efficient way to go + + align:start position:0% +to be an efficient way to go + + + align:start position:0% +to be an efficient way to go +um + + align:start position:0% +um + + + align:start position:0% +um +oh so + + align:start position:0% +oh so + + + align:start position:0% +oh so +while we're here + + align:start position:0% +while we're here + + + align:start position:0% +while we're here +i should mention i mentioned already + + align:start position:0% +i should mention i mentioned already + + + align:start position:0% +i should mention i mentioned already +that the laplacian is the lowest order + + align:start position:0% +that the laplacian is the lowest order + + + align:start position:0% +that the laplacian is the lowest order +linear operator differential operator + + align:start position:0% +linear operator differential operator + + + align:start position:0% +linear operator differential operator +that's rotationally symmetric + + align:start position:0% + + + + align:start position:0% + +here's a non-linear one + + align:start position:0% + + + + align:start position:0% + +so this operator is rotationally + + align:start position:0% +so this operator is rotationally + + + align:start position:0% +so this operator is rotationally +symmetric what do i mean by that i mean + + align:start position:0% +symmetric what do i mean by that i mean + + + align:start position:0% +symmetric what do i mean by that i mean +that if you rotate the coordinate system + + align:start position:0% + + + + align:start position:0% + +you know for example over here + + align:start position:0% +you know for example over here + + + align:start position:0% +you know for example over here +and you compute + + align:start position:0% +and you compute + + + align:start position:0% +and you compute +e sub x + + align:start position:0% +e sub x + + + align:start position:0% +e sub x +dash and square it and add e sub y dash + + align:start position:0% +dash and square it and add e sub y dash + + + align:start position:0% +dash and square it and add e sub y dash +and square it you'll get the same answer + + align:start position:0% +and square it you'll get the same answer + + + align:start position:0% +and square it you'll get the same answer +as if you take + + align:start position:0% +as if you take + + + align:start position:0% +as if you take +so so it doesn't depend on the + + align:start position:0% +so so it doesn't depend on the + + + align:start position:0% +so so it doesn't depend on the +orientation of the + + align:start position:0% +orientation of the + + + align:start position:0% +orientation of the +x axis + + align:start position:0% +x axis + + + align:start position:0% +x axis +and so this is lower order of course in + + align:start position:0% +and so this is lower order of course in + + + align:start position:0% +and so this is lower order of course in +laplacian because it's first order but + + align:start position:0% +laplacian because it's first order but + + + align:start position:0% +laplacian because it's first order but +it's non-linear so + + align:start position:0% +it's non-linear so + + + align:start position:0% +it's non-linear so +nevertheless we run into this quite a + + align:start position:0% +nevertheless we run into this quite a + + + align:start position:0% +nevertheless we run into this quite a +bit because remember uh roberts + + align:start position:0% + + + + align:start position:0% + +use these stencils + + align:start position:0% +use these stencils + + + align:start position:0% +use these stencils +which you can just think of as + + align:start position:0% + + + + align:start position:0% + +ways of computing the derivatives in the + + align:start position:0% +ways of computing the derivatives in the + + + align:start position:0% +ways of computing the derivatives in the +rotated coordinate system and then he + + align:start position:0% +rotated coordinate system and then he + + + align:start position:0% +rotated coordinate system and then he +took the square root of the sum of + + align:start position:0% +took the square root of the sum of + + + align:start position:0% +took the square root of the sum of +squares + + align:start position:0% +squares + + + align:start position:0% +squares +and that was his edge detector + + align:start position:0% +and that was his edge detector + + + align:start position:0% +and that was his edge detector +and so it's equivalent to doing this and + + align:start position:0% +and so it's equivalent to doing this and + + + align:start position:0% +and so it's equivalent to doing this and +for his purposes that + + align:start position:0% +for his purposes that + + + align:start position:0% +for his purposes that +took less computation and he already + + align:start position:0% +took less computation and he already + + + align:start position:0% +took less computation and he already +knew in 1965 + + align:start position:0% +knew in 1965 + + + align:start position:0% +knew in 1965 +that what you want to do is + + align:start position:0% +that what you want to do is + + + align:start position:0% +that what you want to do is +make sure that your ex and ey refer to + + align:start position:0% +make sure that your ex and ey refer to + + + align:start position:0% +make sure that your ex and ey refer to +the same point in pixel space + + align:start position:0% +the same point in pixel space + + + align:start position:0% +the same point in pixel space +a lesson which has since been forgotten + + align:start position:0% +a lesson which has since been forgotten + + + align:start position:0% +a lesson which has since been forgotten +so + + align:start position:0% +so + + + align:start position:0% +so +except here um okay + + align:start position:0% +except here um okay + + + align:start position:0% +except here um okay +so that was the front end and this has + + align:start position:0% +so that was the front end and this has + + + align:start position:0% +so that was the front end and this has +to be very efficient because it's run on + + align:start position:0% +to be very efficient because it's run on + + + align:start position:0% +to be very efficient because it's run on +every pixel + + align:start position:0% +every pixel + + + align:start position:0% +every pixel +and it also lends itself to special + + align:start position:0% +and it also lends itself to special + + + align:start position:0% +and it also lends itself to special +purpose hardware of course + + align:start position:0% +purpose hardware of course + + + align:start position:0% +purpose hardware of course +so the next step was + + align:start position:0% +so the next step was + + + align:start position:0% +so the next step was +our + + align:start position:0% +our + + + align:start position:0% +our +subpixel + + align:start position:0% +subpixel + + + align:start position:0% +subpixel +edge detection method so we used what + + align:start position:0% +edge detection method so we used what + + + align:start position:0% +edge detection method so we used what +is called non-maximum suppression + + align:start position:0% + + + + align:start position:0% + +so um + + align:start position:0% +so um + + + align:start position:0% +so um +this weird terminology i mean why not + + align:start position:0% +this weird terminology i mean why not + + + align:start position:0% +this weird terminology i mean why not +just say finding the maximum + + align:start position:0% +just say finding the maximum + + + align:start position:0% +just say finding the maximum +but there it is so what where did that + + align:start position:0% +but there it is so what where did that + + + align:start position:0% +but there it is so what where did that +terminology come from well the idea is + + align:start position:0% +terminology come from well the idea is + + + align:start position:0% +terminology come from well the idea is +that we apply this edge operator + + align:start position:0% +that we apply this edge operator + + + align:start position:0% +that we apply this edge operator +everywhere and in most places it has a + + align:start position:0% +everywhere and in most places it has a + + + align:start position:0% +everywhere and in most places it has a +kind of feeble response but on the edges + + align:start position:0% +kind of feeble response but on the edges + + + align:start position:0% +kind of feeble response but on the edges +it really kicks up and so one approach + + align:start position:0% +it really kicks up and so one approach + + + align:start position:0% +it really kicks up and so one approach +would be + + align:start position:0% +would be + + + align:start position:0% +would be +you know let's just threshold so if if + + align:start position:0% +you know let's just threshold so if if + + + align:start position:0% +you know let's just threshold so if if +we get a strong response from one of + + align:start position:0% +we get a strong response from one of + + + align:start position:0% +we get a strong response from one of +these molecules here then + + align:start position:0% +these molecules here then + + + align:start position:0% +these molecules here then +that's then we're on the edge and if not + + align:start position:0% +that's then we're on the edge and if not + + + align:start position:0% +that's then we're on the edge and if not +then then we're not well + + align:start position:0% + + + + align:start position:0% + +that + + align:start position:0% +that + + + align:start position:0% +that +involves um early decision making + + align:start position:0% + + + + align:start position:0% + +because once you've made that decision + + align:start position:0% +because once you've made that decision + + + align:start position:0% +because once you've made that decision +uh that's it you'll you you know you + + align:start position:0% +uh that's it you'll you you know you + + + align:start position:0% +uh that's it you'll you you know you +you'll throw away + + align:start position:0% +you'll throw away + + + align:start position:0% +you'll throw away +you'll throw away that edge point and + + align:start position:0% +you'll throw away that edge point and + + + align:start position:0% +you'll throw away that edge point and +never + + align:start position:0% +never + + + align:start position:0% +never +never + + align:start position:0% +never + + + align:start position:0% +never +do any computation with it again because + + align:start position:0% +do any computation with it again because + + + align:start position:0% +do any computation with it again because +you've decided it's below threshold or + + align:start position:0% +you've decided it's below threshold or + + + align:start position:0% +you've decided it's below threshold or +vice versa you picked it as being a + + align:start position:0% +vice versa you picked it as being a + + + align:start position:0% +vice versa you picked it as being a +threshold so + + align:start position:0% +threshold so + + + align:start position:0% +threshold so +a big + + align:start position:0% +a big + + + align:start position:0% +a big +in the patent bill silver makes a big + + align:start position:0% +in the patent bill silver makes a big + + + align:start position:0% +in the patent bill silver makes a big +fuss about + + align:start position:0% +fuss about + + + align:start position:0% +fuss about +avoiding thresholds + + align:start position:0% +avoiding thresholds + + + align:start position:0% +avoiding thresholds +if possible and + + align:start position:0% +if possible and + + + align:start position:0% +if possible and +not making decisions too early that's + + align:start position:0% +not making decisions too early that's + + + align:start position:0% +not making decisions too early that's +his sort of main motivation for not + + align:start position:0% +his sort of main motivation for not + + + align:start position:0% +his sort of main motivation for not +using thresholds + + align:start position:0% +using thresholds + + + align:start position:0% +using thresholds +so some previous + + align:start position:0% +so some previous + + + align:start position:0% +so some previous +edge detection work + + align:start position:0% +edge detection work + + + align:start position:0% +edge detection work +did work that way you apply some + + align:start position:0% +did work that way you apply some + + + align:start position:0% +did work that way you apply some +operator which has a strong response on + + align:start position:0% +operator which has a strong response on + + + align:start position:0% +operator which has a strong response on +the edge and then you threshold and + + align:start position:0% +the edge and then you threshold and + + + align:start position:0% +the edge and then you threshold and +now you get + + align:start position:0% +now you get + + + align:start position:0% +now you get +responses but they're not just right on + + align:start position:0% +responses but they're not just right on + + + align:start position:0% +responses but they're not just right on +the edge because we saw that the edge is + + align:start position:0% +the edge because we saw that the edge is + + + align:start position:0% +the edge because we saw that the edge is +a slow smooth transition so there'll be + + align:start position:0% +a slow smooth transition so there'll be + + + align:start position:0% +a slow smooth transition so there'll be +neighboring points that also have a + + align:start position:0% +neighboring points that also have a + + + align:start position:0% +neighboring points that also have a +strong response + + align:start position:0% +strong response + + + align:start position:0% +strong response +plus + + align:start position:0% +plus + + + align:start position:0% +plus +with noise + + align:start position:0% +with noise + + + align:start position:0% +with noise +there will be points in the background + + align:start position:0% +there will be points in the background + + + align:start position:0% +there will be points in the background +where noise just happens to add up and + + align:start position:0% +where noise just happens to add up and + + + align:start position:0% +where noise just happens to add up and +now there seems to be an edge there so + + align:start position:0% +now there seems to be an edge there so + + + align:start position:0% +now there seems to be an edge there so +that's undesirable + + align:start position:0% + + + + align:start position:0% + +okay so + + align:start position:0% + + + + align:start position:0% + +so the previous methods worked by + + align:start position:0% +so the previous methods worked by + + + align:start position:0% +so the previous methods worked by +thresholding and + + align:start position:0% +thresholding and + + + align:start position:0% +thresholding and +looking + + align:start position:0% +looking + + + align:start position:0% +looking +for things that had a strong edge + + align:start position:0% +for things that had a strong edge + + + align:start position:0% +for things that had a strong edge +response and here instead what we're + + align:start position:0% +response and here instead what we're + + + align:start position:0% +response and here instead what we're +doing is we're going to remove + + align:start position:0% +doing is we're going to remove + + + align:start position:0% +doing is we're going to remove +everything except the maximum but + + align:start position:0% +everything except the maximum but + + + align:start position:0% +everything except the maximum but +maximum in what sense well again just in + + align:start position:0% +maximum in what sense well again just in + + + align:start position:0% +maximum in what sense well again just in +the gradient direction + + align:start position:0% +the gradient direction + + + align:start position:0% +the gradient direction +and so + + align:start position:0% + + + + align:start position:0% + +here here we deal with the unfortunate + + align:start position:0% + + + + align:start position:0% + +fact that + + align:start position:0% + + + + align:start position:0% + +we're going to quantize the gradient + + align:start position:0% +we're going to quantize the gradient + + + align:start position:0% +we're going to quantize the gradient +directions so we're only going to have + + align:start position:0% +directions so we're only going to have + + + align:start position:0% +directions so we're only going to have +you know compass directions + + align:start position:0% +you know compass directions + + + align:start position:0% +you know compass directions +east northeast north northwest west + + align:start position:0% +east northeast north northwest west + + + align:start position:0% +east northeast north northwest west +etcetera eight of them + + align:start position:0% +etcetera eight of them + + + align:start position:0% +etcetera eight of them +and + + align:start position:0% +and + + + align:start position:0% +and +let's suppose that this is our quantized + + align:start position:0% +let's suppose that this is our quantized + + + align:start position:0% +let's suppose that this is our quantized +gradient direction + + align:start position:0% + + + + align:start position:0% + +then + + align:start position:0% +then + + + align:start position:0% +then +we + + align:start position:0% +we + + + align:start position:0% +we +step through the image + + align:start position:0% +step through the image + + + align:start position:0% +step through the image +and we consider + + align:start position:0% +and we consider + + + align:start position:0% +and we consider +those three values + + align:start position:0% +those three values + + + align:start position:0% +those three values +and + + align:start position:0% +and + + + align:start position:0% +and +the non-maximum suppression says that we + + align:start position:0% +the non-maximum suppression says that we + + + align:start position:0% +the non-maximum suppression says that we +will accept this as a potential edge + + align:start position:0% +will accept this as a potential edge + + + align:start position:0% +will accept this as a potential edge +point only if + + align:start position:0% +point only if + + + align:start position:0% +point only if +this is true + + align:start position:0% + + + + align:start position:0% + +right because if + + align:start position:0% +right because if + + + align:start position:0% +right because if +g minus was bigger than g zero well then + + align:start position:0% +g minus was bigger than g zero well then + + + align:start position:0% +g minus was bigger than g zero well then +that's going to be the edge point + + align:start position:0% +that's going to be the edge point + + + align:start position:0% +that's going to be the edge point +and remember that the edge is running at + + align:start position:0% +and remember that the edge is running at + + + align:start position:0% +and remember that the edge is running at +right angles to this lot + + align:start position:0% +right angles to this lot + + + align:start position:0% +right angles to this lot +so the the actual underlying edge is is + + align:start position:0% +so the the actual underlying edge is is + + + align:start position:0% +so the the actual underlying edge is is +is like this + + align:start position:0% +is like this + + + align:start position:0% +is like this +and we're looking in the gradient + + align:start position:0% +and we're looking in the gradient + + + align:start position:0% +and we're looking in the gradient +direction and the gradient direction is + + align:start position:0% +direction and the gradient direction is + + + align:start position:0% +direction and the gradient direction is +of course perpendicular to the edge + + align:start position:0% +of course perpendicular to the edge + + + align:start position:0% +of course perpendicular to the edge +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and then we talked about how + + align:start position:0% +and then we talked about how + + + align:start position:0% +and then we talked about how +there's this asymmetry + + align:start position:0% +there's this asymmetry + + + align:start position:0% +there's this asymmetry +because occasionally we're going to find + + align:start position:0% +because occasionally we're going to find + + + align:start position:0% +because occasionally we're going to find +that g 0 is equal to g minus or g 0 is + + align:start position:0% +that g 0 is equal to g minus or g 0 is + + + align:start position:0% +that g 0 is equal to g minus or g 0 is +equal to g plus and we don't want to + + align:start position:0% +equal to g plus and we don't want to + + + align:start position:0% +equal to g plus and we don't want to +declare both of them to be edge points + + align:start position:0% +declare both of them to be edge points + + + align:start position:0% +declare both of them to be edge points +we want to have a tie breaker + + align:start position:0% +we want to have a tie breaker + + + align:start position:0% +we want to have a tie breaker +so that only one of them gets elected + + align:start position:0% +so that only one of them gets elected + + + align:start position:0% +so that only one of them gets elected +and which one is well it's arbitrary you + + align:start position:0% +and which one is well it's arbitrary you + + + align:start position:0% +and which one is well it's arbitrary you +can you know you could easily well have + + align:start position:0% +can you know you could easily well have + + + align:start position:0% +can you know you could easily well have +done that + + align:start position:0% +done that + + + align:start position:0% +done that +as long as there's a way of + + align:start position:0% +as long as there's a way of + + + align:start position:0% +as long as there's a way of +breaking that + + align:start position:0% +breaking that + + + align:start position:0% +breaking that +tie + + align:start position:0% +tie + + + align:start position:0% +tie +okay and then + + align:start position:0% +okay and then + + + align:start position:0% +okay and then +we said okay now we can plot + + align:start position:0% +we said okay now we can plot + + + align:start position:0% +we said okay now we can plot +the profile of this edge response along + + align:start position:0% +the profile of this edge response along + + + align:start position:0% +the profile of this edge response along +the gradient direction + + align:start position:0% +the gradient direction + + + align:start position:0% +the gradient direction +and we get + + align:start position:0% +and we get + + + align:start position:0% +and we get +a picture like this + + align:start position:0% + + + + align:start position:0% + +and then we can fit some curve to it for + + align:start position:0% +and then we can fit some curve to it for + + + align:start position:0% +and then we can fit some curve to it for +example we can fit a parabola to it + + align:start position:0% +example we can fit a parabola to it + + + align:start position:0% +example we can fit a parabola to it +and we find the peak of the parabola + + align:start position:0% +and we find the peak of the parabola + + + align:start position:0% +and we find the peak of the parabola +and that's our sub pixel edge position + + align:start position:0% +and that's our sub pixel edge position + + + align:start position:0% +and that's our sub pixel edge position +so so several points there one of them + + align:start position:0% +so so several points there one of them + + + align:start position:0% +so so several points there one of them +is you know why fit a parabola well + + align:start position:0% +is you know why fit a parabola well + + + align:start position:0% +is you know why fit a parabola well +that's arbitrary uh you know the the + + align:start position:0% +that's arbitrary uh you know the the + + + align:start position:0% +that's arbitrary uh you know the the +shape of that curve + + align:start position:0% +shape of that curve + + + align:start position:0% +shape of that curve +depends on the optics the image sensor + + align:start position:0% +depends on the optics the image sensor + + + align:start position:0% +depends on the optics the image sensor +the thing you're looking at + + align:start position:0% +the thing you're looking at + + + align:start position:0% +the thing you're looking at +and + + align:start position:0% +and + + + align:start position:0% +and +but we only get three samples of it so + + align:start position:0% +but we only get three samples of it so + + + align:start position:0% +but we only get three samples of it so +treating it as a smooth curve the lowest + + align:start position:0% +treating it as a smooth curve the lowest + + + align:start position:0% +treating it as a smooth curve the lowest +order polynomial that will work is + + align:start position:0% +order polynomial that will work is + + + align:start position:0% +order polynomial that will work is +second order so uh one option we have is + + align:start position:0% +second order so uh one option we have is + + + align:start position:0% +second order so uh one option we have is +to use that and not to say that that's + + align:start position:0% +to use that and not to say that that's + + + align:start position:0% +to use that and not to say that that's +the only option or the best one but it's + + align:start position:0% +the only option or the best one but it's + + + align:start position:0% +the only option or the best one but it's +you know pretty good guess + + align:start position:0% +you know pretty good guess + + + align:start position:0% +you know pretty good guess +uh next thing is that what what's s well + + align:start position:0% +uh next thing is that what what's s well + + + align:start position:0% +uh next thing is that what what's s well +s is the displacement from g0 + + align:start position:0% +s is the displacement from g0 + + + align:start position:0% +s is the displacement from g0 +so in here + + align:start position:0% +so in here + + + align:start position:0% +so in here +s0 would be that point + + align:start position:0% +s0 would be that point + + + align:start position:0% +s0 would be that point +and then if s is say + + align:start position:0% +and then if s is say + + + align:start position:0% +and then if s is say +well if we get over here then s is a + + align:start position:0% +well if we get over here then s is a + + + align:start position:0% +well if we get over here then s is a +half + + align:start position:0% +half + + + align:start position:0% +half +no so if we get over here then s is a + + align:start position:0% +no so if we get over here then s is a + + + align:start position:0% +no so if we get over here then s is a +half + + align:start position:0% +half + + + align:start position:0% +half +right we're halfway to that point and + + align:start position:0% +right we're halfway to that point and + + + align:start position:0% +right we're halfway to that point and +obviously it doesn't make sense for s to + + align:start position:0% +obviously it doesn't make sense for s to + + + align:start position:0% +obviously it doesn't make sense for s to +be bigger than a half because then this + + align:start position:0% +be bigger than a half because then this + + + align:start position:0% +be bigger than a half because then this +would have been the maximum + + align:start position:0% +would have been the maximum + + + align:start position:0% +would have been the maximum +right so + + align:start position:0% +right so + + + align:start position:0% +right so +and same in the other direction + + align:start position:0% + + + + align:start position:0% + +notice that s is not in units of pixels + + align:start position:0% +notice that s is not in units of pixels + + + align:start position:0% +notice that s is not in units of pixels +because + + align:start position:0% +because + + + align:start position:0% +because +in this diagonal case + + align:start position:0% +in this diagonal case + + + align:start position:0% +in this diagonal case +s equals 1 is that distance which is the + + align:start position:0% +s equals 1 is that distance which is the + + + align:start position:0% +s equals 1 is that distance which is the +square root of 2 + + align:start position:0% +square root of 2 + + + align:start position:0% +square root of 2 +times the pixel spacing + + align:start position:0% +times the pixel spacing + + + align:start position:0% +times the pixel spacing +right whereas if we happen to get the + + align:start position:0% +right whereas if we happen to get the + + + align:start position:0% +right whereas if we happen to get the +quantized direction over here + + align:start position:0% +quantized direction over here + + + align:start position:0% +quantized direction over here +then s would be the pixel spacing + + align:start position:0% +then s would be the pixel spacing + + + align:start position:0% +then s would be the pixel spacing +so + + align:start position:0% +so + + + align:start position:0% +so +um + + align:start position:0% +um + + + align:start position:0% +um +that's something to keep in mind that it + + align:start position:0% +that's something to keep in mind that it + + + align:start position:0% +that's something to keep in mind that it +all depends on the actual gradient + + align:start position:0% +all depends on the actual gradient + + + align:start position:0% +all depends on the actual gradient +direction + + align:start position:0% + + + + align:start position:0% + +okay um + + align:start position:0% +okay um + + + align:start position:0% +okay um +avoid thresholds yeah + + align:start position:0% + + + + align:start position:0% + +and so now um + + align:start position:0% +and so now um + + + align:start position:0% +and so now um +we have uh a potential edge point + + align:start position:0% +we have uh a potential edge point + + + align:start position:0% +we have uh a potential edge point +uh and notice we're not doing any + + align:start position:0% +uh and notice we're not doing any + + + align:start position:0% +uh and notice we're not doing any +thresholding so + + align:start position:0% +thresholding so + + + align:start position:0% +thresholding so +we get we're gonna get these points all + + align:start position:0% +we get we're gonna get these points all + + + align:start position:0% +we get we're gonna get these points all +over the show not just on on the edge we + + align:start position:0% +over the show not just on on the edge we + + + align:start position:0% +over the show not just on on the edge we +haven't done any thresholding so here + + align:start position:0% +haven't done any thresholding so here + + + align:start position:0% +haven't done any thresholding so here +you know we we mark uh this place + + align:start position:0% +you know we we mark uh this place + + + align:start position:0% +you know we we mark uh this place +based on + + align:start position:0% +based on + + + align:start position:0% +based on +uh + + align:start position:0% +uh + + + align:start position:0% +uh +square root of 2 s delta where delta is + + align:start position:0% +square root of 2 s delta where delta is + + + align:start position:0% +square root of 2 s delta where delta is +the pixel spacing so just to be precise + + align:start position:0% +the pixel spacing so just to be precise + + + align:start position:0% +the pixel spacing so just to be precise +so that's that's where we think the edge + + align:start position:0% +so that's that's where we think the edge + + + align:start position:0% +so that's that's where we think the edge +is so i've drawn the edge here but + + align:start position:0% +is so i've drawn the edge here but + + + align:start position:0% +is so i've drawn the edge here but +actually + + align:start position:0% +actually + + + align:start position:0% +actually +now with sub pixel interpolation + + align:start position:0% +now with sub pixel interpolation + + + align:start position:0% +now with sub pixel interpolation +we find it's it's there + + align:start position:0% +we find it's it's there + + + align:start position:0% +we find it's it's there +so if we just were to go with the peak + + align:start position:0% +so if we just were to go with the peak + + + align:start position:0% +so if we just were to go with the peak +in that curve uh on a discrete grid then + + align:start position:0% +in that curve uh on a discrete grid then + + + align:start position:0% +in that curve uh on a discrete grid then +we'd find that the edge runs through + + align:start position:0% +we'd find that the edge runs through + + + align:start position:0% +we'd find that the edge runs through +that point but now we know it's it's + + align:start position:0% +that point but now we know it's it's + + + align:start position:0% +that point but now we know it's it's +over there + + align:start position:0% +over there + + + align:start position:0% +over there +okay but in order to get there we + + align:start position:0% + + + + align:start position:0% + +will quantize the + + align:start position:0% + + + + align:start position:0% + +we quantize the edge direction + + align:start position:0% +we quantize the edge direction + + + align:start position:0% +we quantize the edge direction +and so we can + + align:start position:0% +and so we can + + + align:start position:0% +and so we can +improve things slightly + + align:start position:0% + + + + align:start position:0% + +right so i suppose i should draw that + + align:start position:0% +right so i suppose i should draw that + + + align:start position:0% +right so i suppose i should draw that +again and make it less messy + + align:start position:0% + + + + align:start position:0% + +so here's our quantized direction + + align:start position:0% +so here's our quantized direction + + + align:start position:0% +so here's our quantized direction +and here's some point we found that's uh + + align:start position:0% +and here's some point we found that's uh + + + align:start position:0% +and here's some point we found that's uh +an edge point + + align:start position:0% +an edge point + + + align:start position:0% +an edge point +and then suppose that the actual + + align:start position:0% +and then suppose that the actual + + + align:start position:0% +and then suppose that the actual +gradient direction + + align:start position:0% +gradient direction + + + align:start position:0% +gradient direction +is + + align:start position:0% +is + + + align:start position:0% +is +slightly different + + align:start position:0% +slightly different + + + align:start position:0% +slightly different +it can't be hugely different + + align:start position:0% +it can't be hugely different + + + align:start position:0% +it can't be hugely different +because + + align:start position:0% +because + + + align:start position:0% +because +then we would have picked a different + + align:start position:0% +then we would have picked a different + + + align:start position:0% +then we would have picked a different +compass direction + + align:start position:0% +compass direction + + + align:start position:0% +compass direction +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so + + align:start position:0% + + + + align:start position:0% + +now + + align:start position:0% +now + + + align:start position:0% +now +um + + align:start position:0% +um + + + align:start position:0% +um +that's the gradient direction so the h + + align:start position:0% +that's the gradient direction so the h + + + align:start position:0% +that's the gradient direction so the h +has to be perpendicular to it so i can + + align:start position:0% +has to be perpendicular to it so i can + + + align:start position:0% +has to be perpendicular to it so i can +draw a perpendicular to the green line + + align:start position:0% +draw a perpendicular to the green line + + + align:start position:0% +draw a perpendicular to the green line +um + + align:start position:0% +um + + + align:start position:0% +um +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +that passes through this point + + align:start position:0% +that passes through this point + + + align:start position:0% +that passes through this point +so the edge actually + + align:start position:0% +so the edge actually + + + align:start position:0% +so the edge actually +is like this + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +when i report a potential + + align:start position:0% +when i report a potential + + + align:start position:0% +when i report a potential +edge point i can report any point on on + + align:start position:0% +edge point i can report any point on on + + + align:start position:0% +edge point i can report any point on on +that line + + align:start position:0% +that line + + + align:start position:0% +that line +and which one do i pick well the + + align:start position:0% +and which one do i pick well the + + + align:start position:0% +and which one do i pick well the +simplest one is just to pick the one i + + align:start position:0% +simplest one is just to pick the one i + + + align:start position:0% +simplest one is just to pick the one i +calculated + + align:start position:0% +calculated + + + align:start position:0% +calculated +i can however slightly improve the + + align:start position:0% +i can however slightly improve the + + + align:start position:0% +i can however slightly improve the +result by uh instead picking this one + + align:start position:0% +result by uh instead picking this one + + + align:start position:0% +result by uh instead picking this one +why + + align:start position:0% +why + + + align:start position:0% +why +well it's closer to the origin it's + + align:start position:0% +well it's closer to the origin it's + + + align:start position:0% +well it's closer to the origin it's +closer to the actual peak + + align:start position:0% +closer to the actual peak + + + align:start position:0% +closer to the actual peak +and so it's + + align:start position:0% +and so it's + + + align:start position:0% +and so it's +less likely to be + + align:start position:0% +less likely to be + + + align:start position:0% +less likely to be +subject to noise + + align:start position:0% +subject to noise + + + align:start position:0% +subject to noise +it's not a huge improvement but you know + + align:start position:0% +it's not a huge improvement but you know + + + align:start position:0% +it's not a huge improvement but you know +they decided this was a worthwhile + + align:start position:0% + + + + align:start position:0% + +additional step + + align:start position:0% + + + + align:start position:0% + +it also actually aids in + + align:start position:0% +it also actually aids in + + + align:start position:0% +it also actually aids in +a step that we will be getting to in a + + align:start position:0% +a step that we will be getting to in a + + + align:start position:0% +a step that we will be getting to in a +second where we chain together the edges + + align:start position:0% +second where we chain together the edges + + + align:start position:0% +second where we chain together the edges +okay so that's the idea so we project + + align:start position:0% +okay so that's the idea so we project + + + align:start position:0% +okay so that's the idea so we project +we project from the quantized uh + + align:start position:0% +we project from the quantized uh + + + align:start position:0% +we project from the quantized uh +gradient direction down onto the actual + + align:start position:0% +gradient direction down onto the actual + + + align:start position:0% +gradient direction down onto the actual +gradient direction and + + align:start position:0% +gradient direction and + + + align:start position:0% +gradient direction and +that's the plane position step + + align:start position:0% +that's the plane position step + + + align:start position:0% +that's the plane position step +what next o so then + + align:start position:0% +what next o so then + + + align:start position:0% +what next o so then +we get to the bias compensation + + align:start position:0% + + + + align:start position:0% + +okay so we we said that we somewhat + + align:start position:0% +okay so we we said that we somewhat + + + align:start position:0% +okay so we we said that we somewhat +arbitrarily picked the parabola + + align:start position:0% +arbitrarily picked the parabola + + + align:start position:0% +arbitrarily picked the parabola +and then as you know in the patent + + align:start position:0% +and then as you know in the patent + + + align:start position:0% +and then as you know in the patent +there's a second method which uses + + align:start position:0% +there's a second method which uses + + + align:start position:0% +there's a second method which uses +a rooftop a triangular shape + + align:start position:0% + + + + align:start position:0% + +he uses that + + align:start position:0% +he uses that + + + align:start position:0% +he uses that +it fits that and finds the peak of that + + align:start position:0% +it fits that and finds the peak of that + + + align:start position:0% +it fits that and finds the peak of that +and + + align:start position:0% +and + + + align:start position:0% +and +and that gives you another possible + + align:start position:0% +and that gives you another possible + + + align:start position:0% +and that gives you another possible +position for where the edge really is + + align:start position:0% +position for where the edge really is + + + align:start position:0% +position for where the edge really is +and we said that in certain + + align:start position:0% +and we said that in certain + + + align:start position:0% +and we said that in certain +circumstances one may be more accurate + + align:start position:0% +circumstances one may be more accurate + + + align:start position:0% +circumstances one may be more accurate +give you a more accurate answer than the + + align:start position:0% +give you a more accurate answer than the + + + align:start position:0% +give you a more accurate answer than the +other + + align:start position:0% +other + + + align:start position:0% +other +but what you can imagine doing is + + align:start position:0% +but what you can imagine doing is + + + align:start position:0% +but what you can imagine doing is +actually + + align:start position:0% +actually + + + align:start position:0% +actually +you know experimentally + + align:start position:0% +you know experimentally + + + align:start position:0% +you know experimentally +moving the edge + + align:start position:0% +moving the edge + + + align:start position:0% +moving the edge +by very small increments + + align:start position:0% +by very small increments + + + align:start position:0% +by very small increments +tiny sub pixel increments and seeing + + align:start position:0% +tiny sub pixel increments and seeing + + + align:start position:0% +tiny sub pixel increments and seeing +what your method gives you and then + + align:start position:0% +what your method gives you and then + + + align:start position:0% +what your method gives you and then +plotting that + + align:start position:0% +plotting that + + + align:start position:0% +plotting that +against what it should have been right + + align:start position:0% +against what it should have been right + + + align:start position:0% +against what it should have been right +so this is an experiment where + + align:start position:0% +so this is an experiment where + + + align:start position:0% +so this is an experiment where +you have the camera looking at an edge + + align:start position:0% +you have the camera looking at an edge + + + align:start position:0% +you have the camera looking at an edge +and then you + + align:start position:0% +and then you + + + align:start position:0% +and then you +move the edge or the camera by some tiny + + align:start position:0% +move the edge or the camera by some tiny + + + align:start position:0% +move the edge or the camera by some tiny +amount + + align:start position:0% +amount + + + align:start position:0% +amount +in increments and and you measure + + align:start position:0% + + + + align:start position:0% + +now ideally + + align:start position:0% +now ideally + + + align:start position:0% +now ideally +you know your magic method for peak + + align:start position:0% +you know your magic method for peak + + + align:start position:0% +you know your magic method for peak +finding + + align:start position:0% +finding + + + align:start position:0% +finding +should + + align:start position:0% +should + + + align:start position:0% +should +always give you + + align:start position:0% +always give you + + + align:start position:0% +always give you +the correct peak value + + align:start position:0% + + + + align:start position:0% + +but + + align:start position:0% + + + + align:start position:0% + +it may not + + align:start position:0% +it may not + + + align:start position:0% +it may not +so ideally you get a 45 degree + + align:start position:0% +so ideally you get a 45 degree + + + align:start position:0% +so ideally you get a 45 degree +line and again we're only interested in + + align:start position:0% +line and again we're only interested in + + + align:start position:0% +line and again we're only interested in +the range from minus a half to plus a + + align:start position:0% +the range from minus a half to plus a + + + align:start position:0% +the range from minus a half to plus a +half + + align:start position:0% +half + + + align:start position:0% +half +and now all of these methods should give + + align:start position:0% +and now all of these methods should give + + + align:start position:0% +and now all of these methods should give +you the correct answer in three cases + + align:start position:0% +you the correct answer in three cases + + + align:start position:0% +you the correct answer in three cases +no matter what you do + + align:start position:0% +no matter what you do + + + align:start position:0% +no matter what you do +if you act if your peak is actually a g + + align:start position:0% +if you act if your peak is actually a g + + + align:start position:0% +if you act if your peak is actually a g +zero then it should return g zero that + + align:start position:0% +zero then it should return g zero that + + + align:start position:0% +zero then it should return g zero that +position s equals zero and similarly if + + align:start position:0% +position s equals zero and similarly if + + + align:start position:0% +position s equals zero and similarly if +you were halfway between pixels it + + align:start position:0% +you were halfway between pixels it + + + align:start position:0% +you were halfway between pixels it +should give you the and both of these + + align:start position:0% +should give you the and both of these + + + align:start position:0% +should give you the and both of these +methods do + + align:start position:0% +methods do + + + align:start position:0% +methods do +they satisfy that requirement but what + + align:start position:0% +they satisfy that requirement but what + + + align:start position:0% +they satisfy that requirement but what +happens in between well uh as i + + align:start position:0% +happens in between well uh as i + + + align:start position:0% +happens in between well uh as i +mentioned that depends on + + align:start position:0% +mentioned that depends on + + + align:start position:0% +mentioned that depends on +you know exactly what shape the edge has + + align:start position:0% + + + + align:start position:0% + +so and you might end up with you know + + align:start position:0% +so and you might end up with you know + + + align:start position:0% +so and you might end up with you know +something like this + + align:start position:0% + + + + align:start position:0% + +or maybe something like that + + align:start position:0% +or maybe something like that + + + align:start position:0% +or maybe something like that +so typically the departures from the + + align:start position:0% +so typically the departures from the + + + align:start position:0% +so typically the departures from the +diagonal will be quite small and + + align:start position:0% +diagonal will be quite small and + + + align:start position:0% +diagonal will be quite small and +typically they'll be quite smooth + + align:start position:0% +typically they'll be quite smooth + + + align:start position:0% +typically they'll be quite smooth +and so + + align:start position:0% +and so + + + align:start position:0% +and so +you know you could keep a lookup table + + align:start position:0% +you know you could keep a lookup table + + + align:start position:0% +you know you could keep a lookup table +of this or something to compensate for + + align:start position:0% +of this or something to compensate for + + + align:start position:0% +of this or something to compensate for +it but it's it's not really worthwhile + + align:start position:0% +it but it's it's not really worthwhile + + + align:start position:0% +it but it's it's not really worthwhile +it's it's a relatively small correction + + align:start position:0% +it's it's a relatively small correction + + + align:start position:0% +it's it's a relatively small correction +again but in going down to the the aim + + align:start position:0% +again but in going down to the the aim + + + align:start position:0% +again but in going down to the the aim +is uh 1 40th of a pixel + + align:start position:0% +is uh 1 40th of a pixel + + + align:start position:0% +is uh 1 40th of a pixel +accuracy + + align:start position:0% +accuracy + + + align:start position:0% +accuracy +so you know if you think about it that's + + align:start position:0% +so you know if you think about it that's + + + align:start position:0% +so you know if you think about it that's +that's quite amazing that you can do + + align:start position:0% +that's quite amazing that you can do + + + align:start position:0% +that's quite amazing that you can do +that + + align:start position:0% +that + + + align:start position:0% +that +but + + align:start position:0% + + + + align:start position:0% + +and one part of it + + align:start position:0% +and one part of it + + + align:start position:0% +and one part of it +one part of it is this plane position + + align:start position:0% +one part of it is this plane position + + + align:start position:0% +one part of it is this plane position +correction and one part of it is this + + align:start position:0% +correction and one part of it is this + + + align:start position:0% +correction and one part of it is this +and so what + + align:start position:0% + + + + align:start position:0% + +what is done + + align:start position:0% +what is done + + + align:start position:0% +what is done +is to + + align:start position:0% +is to + + + align:start position:0% +is to +approximate whatever that shape is + + align:start position:0% +approximate whatever that shape is + + + align:start position:0% +approximate whatever that shape is +with this function + + align:start position:0% +with this function + + + align:start position:0% +with this function +and so for example + + align:start position:0% +and so for example + + + align:start position:0% +and so for example +for b equals 0 + + align:start position:0% +for b equals 0 + + + align:start position:0% +for b equals 0 +we get s prime equals s so that's just + + align:start position:0% +we get s prime equals s so that's just + + + align:start position:0% +we get s prime equals s so that's just +the diagonal line that's the ideal case + + align:start position:0% +the diagonal line that's the ideal case + + + align:start position:0% +the diagonal line that's the ideal case +for b greater than 0 + + align:start position:0% + + + + align:start position:0% + +then that means that s prime + + align:start position:0% +then that means that s prime + + + align:start position:0% +then that means that s prime +is uh s raised to a power greater than + + align:start position:0% +is uh s raised to a power greater than + + + align:start position:0% +is uh s raised to a power greater than +one + + align:start position:0% +one + + + align:start position:0% +one +and so that means it's going to bow uh + + align:start position:0% +and so that means it's going to bow uh + + + align:start position:0% +and so that means it's going to bow uh +this way + + align:start position:0% +this way + + + align:start position:0% +this way +as as the red curve does + + align:start position:0% +as as the red curve does + + + align:start position:0% +as as the red curve does +and if b is less than zero that means + + align:start position:0% +and if b is less than zero that means + + + align:start position:0% +and if b is less than zero that means +that s prime is s raised to a power + + align:start position:0% +that s prime is s raised to a power + + + align:start position:0% +that s prime is s raised to a power +that's slightly less than one so that's + + align:start position:0% +that's slightly less than one so that's + + + align:start position:0% +that's slightly less than one so that's +like approximating square root so that's + + align:start position:0% +like approximating square root so that's + + + align:start position:0% +like approximating square root so that's +this uh bowed upper upper curve + + align:start position:0% +this uh bowed upper upper curve + + + align:start position:0% +this uh bowed upper upper curve +which i'll show in green + + align:start position:0% + + + + align:start position:0% + +so that's + + align:start position:0% +so that's + + + align:start position:0% +so that's +green + + align:start position:0% +green + + + align:start position:0% +green +and the other one is red + + align:start position:0% +and the other one is red + + + align:start position:0% +and the other one is red +so + + align:start position:0% + + + + align:start position:0% + +what's the point the point is that + + align:start position:0% +what's the point the point is that + + + align:start position:0% +what's the point the point is that +this is a small correction + + align:start position:0% +this is a small correction + + + align:start position:0% +this is a small correction +so it doesn't really pay to try and be + + align:start position:0% +so it doesn't really pay to try and be + + + align:start position:0% +so it doesn't really pay to try and be +too fussy but you want to do it and this + + align:start position:0% +too fussy but you want to do it and this + + + align:start position:0% +too fussy but you want to do it and this +is a one parameter fit + + align:start position:0% +is a one parameter fit + + + align:start position:0% +is a one parameter fit +to the type of curve that what's the b + + align:start position:0% +to the type of curve that what's the b + + + align:start position:0% +to the type of curve that what's the b +is the one parameter + + align:start position:0% +is the one parameter + + + align:start position:0% +is the one parameter +and so uh + + align:start position:0% +and so uh + + + align:start position:0% +and so uh +you could calibrate it + + align:start position:0% +you could calibrate it + + + align:start position:0% +you could calibrate it +based on + + align:start position:0% +based on + + + align:start position:0% +based on +this method + + align:start position:0% +this method + + + align:start position:0% +this method +you know get one value of b you could + + align:start position:0% +you know get one value of b you could + + + align:start position:0% +you know get one value of b you could +calibrate it based on this method get a + + align:start position:0% +calibrate it based on this method get a + + + align:start position:0% +calibrate it based on this method get a +different value of b then + + align:start position:0% +different value of b then + + + align:start position:0% +different value of b then +you notice that if we are happen to be + + align:start position:0% +you notice that if we are happen to be + + + align:start position:0% +you notice that if we are happen to be +working east-west + + align:start position:0% +working east-west + + + align:start position:0% +working east-west +the spacing between pixels is much less + + align:start position:0% +the spacing between pixels is much less + + + align:start position:0% +the spacing between pixels is much less +than if we're working + + align:start position:0% +than if we're working + + + align:start position:0% +than if we're working +northeast + + align:start position:0% +northeast + + + align:start position:0% +northeast +and so it turns out you want a different + + align:start position:0% +and so it turns out you want a different + + + align:start position:0% +and so it turns out you want a different +value of b + + align:start position:0% +value of b + + + align:start position:0% +value of b +for for this case than you do for that + + align:start position:0% +for for this case than you do for that + + + align:start position:0% +for for this case than you do for that +case + + align:start position:0% +case + + + align:start position:0% +case +fortunately the only two cases you know + + align:start position:0% +fortunately the only two cases you know + + + align:start position:0% +fortunately the only two cases you know +they're the ones that are east west + + align:start position:0% +they're the ones that are east west + + + align:start position:0% +they're the ones that are east west +north south and then the ones in between + + align:start position:0% +north south and then the ones in between + + + align:start position:0% +north south and then the ones in between +but you you can use a different value of + + align:start position:0% +but you you can use a different value of + + + align:start position:0% +but you you can use a different value of +b for those two + + align:start position:0% +b for those two + + + align:start position:0% +b for those two +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and you know again you could do + + align:start position:0% +and you know again you could do + + + align:start position:0% +and you know again you could do +something more elaborate but + + align:start position:0% +something more elaborate but + + + align:start position:0% +something more elaborate but +since it's a small correction it's only + + align:start position:0% +since it's a small correction it's only + + + align:start position:0% +since it's a small correction it's only +going to + + align:start position:0% +going to + + + align:start position:0% +going to +affect + + align:start position:0% +affect + + + align:start position:0% +affect +a small fraction of a pixel also + + align:start position:0% +a small fraction of a pixel also + + + align:start position:0% +a small fraction of a pixel also +um you don't want to be too clever here + + align:start position:0% +um you don't want to be too clever here + + + align:start position:0% +um you don't want to be too clever here +because + + align:start position:0% +because + + + align:start position:0% +because +this curve is going to change a little + + align:start position:0% +this curve is going to change a little + + + align:start position:0% +this curve is going to change a little +bit with circumstances you know if if + + align:start position:0% +bit with circumstances you know if if + + + align:start position:0% +bit with circumstances you know if if +your camera is slightly out of focus + + align:start position:0% +your camera is slightly out of focus + + + align:start position:0% +your camera is slightly out of focus +you'll get a slightly different result + + align:start position:0% +you'll get a slightly different result + + + align:start position:0% +you'll get a slightly different result +if the corners of the cardboard box + + align:start position:0% +if the corners of the cardboard box + + + align:start position:0% +if the corners of the cardboard box +you're looking at are somewhat + + align:start position:0% +you're looking at are somewhat + + + align:start position:0% +you're looking at are somewhat +damaged then you'll get a different edge + + align:start position:0% +damaged then you'll get a different edge + + + align:start position:0% +damaged then you'll get a different edge +response and so on so you don't want to + + align:start position:0% +response and so on so you don't want to + + + align:start position:0% +response and so on so you don't want to +be + + align:start position:0% +be + + + align:start position:0% +be +too overly clever + + align:start position:0% +too overly clever + + + align:start position:0% +too overly clever +okay now a lot of this depends on the + + align:start position:0% +okay now a lot of this depends on the + + + align:start position:0% +okay now a lot of this depends on the +actual edge transition + + align:start position:0% + + + + align:start position:0% + +and you know we we drew one just + + align:start position:0% +and you know we we drew one just + + + align:start position:0% +and you know we we drew one just +by hand and uh + + align:start position:0% +by hand and uh + + + align:start position:0% +by hand and uh +then uh + + align:start position:0% +then uh + + + align:start position:0% +then uh +came up with these methods for finding + + align:start position:0% +came up with these methods for finding + + + align:start position:0% +came up with these methods for finding +out where the edge actually is but uh + + align:start position:0% +out where the edge actually is but uh + + + align:start position:0% +out where the edge actually is but uh +realistically what you know what's + + align:start position:0% +realistically what you know what's + + + align:start position:0% +realistically what you know what's +causing these edges to be fuzzy + + align:start position:0% +causing these edges to be fuzzy + + + align:start position:0% +causing these edges to be fuzzy +and we already said that it's a good + + align:start position:0% +and we already said that it's a good + + + align:start position:0% +and we already said that it's a good +thing they are fuzzy otherwise we + + align:start position:0% +thing they are fuzzy otherwise we + + + align:start position:0% +thing they are fuzzy otherwise we +wouldn't be able to um do the sub-pixel + + align:start position:0% +wouldn't be able to um do the sub-pixel + + + align:start position:0% +wouldn't be able to um do the sub-pixel +recovery + + align:start position:0% +recovery + + + align:start position:0% +recovery +we'd be suffering from uh huge aliasing + + align:start position:0% +we'd be suffering from uh huge aliasing + + + align:start position:0% +we'd be suffering from uh huge aliasing +problems + + align:start position:0% +problems + + + align:start position:0% +problems +so it's it's a good thing they're fussy + + align:start position:0% +so it's it's a good thing they're fussy + + + align:start position:0% +so it's it's a good thing they're fussy +but you know why are they fuzzy well one + + align:start position:0% +but you know why are they fuzzy well one + + + align:start position:0% +but you know why are they fuzzy well one +reason is the defocus + + align:start position:0% +reason is the defocus + + + align:start position:0% +reason is the defocus +so let's just look at that uh as a + + align:start position:0% +so let's just look at that uh as a + + + align:start position:0% +so let's just look at that uh as a +special case that's of interest for + + align:start position:0% +special case that's of interest for + + + align:start position:0% +special case that's of interest for +other reasons so here's our lens + + align:start position:0% +other reasons so here's our lens + + + align:start position:0% +other reasons so here's our lens +and you know the objects up there + + align:start position:0% +and you know the objects up there + + + align:start position:0% +and you know the objects up there +and it's suppose that + + align:start position:0% +and it's suppose that + + + align:start position:0% +and it's suppose that +it's it's a point + + align:start position:0% +it's it's a point + + + align:start position:0% +it's it's a point +light source + + align:start position:0% +light source + + + align:start position:0% +light source +and this is the in focus plane + + align:start position:0% + + + + align:start position:0% + +where + + align:start position:0% +where + + + align:start position:0% +where +that distant light source + + align:start position:0% +that distant light source + + + align:start position:0% +that distant light source +star maybe is image as a point + + align:start position:0% +star maybe is image as a point + + + align:start position:0% +star maybe is image as a point +but our + + align:start position:0% + + + + align:start position:0% + +camera + + align:start position:0% +camera + + + align:start position:0% +camera +has the + + align:start position:0% +has the + + + align:start position:0% +has the +image plane slightly + + align:start position:0% +image plane slightly + + + align:start position:0% +image plane slightly +off + + align:start position:0% +off + + + align:start position:0% +off +and so the picture will be slightly out + + align:start position:0% +and so the picture will be slightly out + + + align:start position:0% +and so the picture will be slightly out +of focus + + align:start position:0% +of focus + + + align:start position:0% +of focus +so what did i call this + + align:start position:0% +so what did i call this + + + align:start position:0% +so what did i call this +so this is + + align:start position:0% +so this is + + + align:start position:0% +so this is +f + + align:start position:0% +f + + + align:start position:0% +f +and i guess i call this delta + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +when i look at the image of that star + + align:start position:0% +when i look at the image of that star + + + align:start position:0% +when i look at the image of that star +it's no longer a impulse a point + + align:start position:0% +it's no longer a impulse a point + + + align:start position:0% +it's no longer a impulse a point +it's a circle + + align:start position:0% +it's a circle + + + align:start position:0% +it's a circle +so the + + align:start position:0% + + + + align:start position:0% + +uniform uniform brightness + + align:start position:0% + + + + align:start position:0% + +and if i want to plot it as a function + + align:start position:0% +and if i want to plot it as a function + + + align:start position:0% +and if i want to plot it as a function +of x and y + + align:start position:0% + + + + align:start position:0% + +it would look like this and + + align:start position:0% +it would look like this and + + + align:start position:0% +it would look like this and +i don't know i call this a pill box + + align:start position:0% +i don't know i call this a pill box + + + align:start position:0% +i don't know i call this a pill box +i guess people don't have pill boxes + + align:start position:0% +i guess people don't have pill boxes + + + align:start position:0% +i guess people don't have pill boxes +anymore but it's a cylinder of constant + + align:start position:0% +anymore but it's a cylinder of constant + + + align:start position:0% +anymore but it's a cylinder of constant +height + + align:start position:0% +height + + + align:start position:0% +height +and if i want to describe it + + align:start position:0% +and if i want to describe it + + + align:start position:0% +and if i want to describe it +mathematically + + align:start position:0% + + + + align:start position:0% + +so what's that + + align:start position:0% +so what's that + + + align:start position:0% +so what's that +big r is the radius of of the little + + align:start position:0% +big r is the radius of of the little + + + align:start position:0% +big r is the radius of of the little +pill box + + align:start position:0% +pill box + + + align:start position:0% +pill box +and i divide by 1 over pi r squared + + align:start position:0% +and i divide by 1 over pi r squared + + + align:start position:0% +and i divide by 1 over pi r squared +because + + align:start position:0% +because + + + align:start position:0% +because +the same energy is being deposited into + + align:start position:0% +the same energy is being deposited into + + + align:start position:0% +the same energy is being deposited into +that area no matter how out of focus i + + align:start position:0% +that area no matter how out of focus i + + + align:start position:0% +that area no matter how out of focus i +am + + align:start position:0% +am + + + align:start position:0% +am +so if i'm in focus it's all that + + align:start position:0% +so if i'm in focus it's all that + + + align:start position:0% +so if i'm in focus it's all that +concentrated at one point if i'm out of + + align:start position:0% +concentrated at one point if i'm out of + + + align:start position:0% +concentrated at one point if i'm out of +focus that same amount of light is + + align:start position:0% +focus that same amount of light is + + + align:start position:0% +focus that same amount of light is +spread into a larger and larger + + align:start position:0% +spread into a larger and larger + + + align:start position:0% +spread into a larger and larger +circle + + align:start position:0% +circle + + + align:start position:0% +circle +and so i compensate for that by dividing + + align:start position:0% +and so i compensate for that by dividing + + + align:start position:0% +and so i compensate for that by dividing +by the pi the area of the circle + + align:start position:0% +by the pi the area of the circle + + + align:start position:0% +by the pi the area of the circle +and then what's this so this is the unit + + align:start position:0% +and then what's this so this is the unit + + + align:start position:0% +and then what's this so this is the unit +step function + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +so for r + + align:start position:0% +so for r + + + align:start position:0% +so for r +equal to zero + + align:start position:0% +equal to zero + + + align:start position:0% +equal to zero +this will be u of sum minus quantity so + + align:start position:0% +this will be u of sum minus quantity so + + + align:start position:0% +this will be u of sum minus quantity so +that will be zero so i get one minus + + align:start position:0% +that will be zero so i get one minus + + + align:start position:0% +that will be zero so i get one minus +zero and so + + align:start position:0% +zero and so + + + align:start position:0% +zero and so +this will just be one and then when i + + align:start position:0% +this will just be one and then when i + + + align:start position:0% +this will just be one and then when i +get out to the radius if i go past the + + align:start position:0% +get out to the radius if i go past the + + + align:start position:0% +get out to the radius if i go past the +radius if little r is bigger than big r + + align:start position:0% +radius if little r is bigger than big r + + + align:start position:0% +radius if little r is bigger than big r +this will be equal the step function is + + align:start position:0% +this will be equal the step function is + + + align:start position:0% +this will be equal the step function is +one right because this will be greater + + align:start position:0% +one right because this will be greater + + + align:start position:0% +one right because this will be greater +than zero + + align:start position:0% +than zero + + + align:start position:0% +than zero +and so i get one minus one is zero so + + align:start position:0% +and so i get one minus one is zero so + + + align:start position:0% +and so i get one minus one is zero so +it's it's just a fancy way of + + align:start position:0% +it's it's just a fancy way of + + + align:start position:0% +it's it's just a fancy way of +saying the same thing as that diagram + + align:start position:0% +saying the same thing as that diagram + + + align:start position:0% +saying the same thing as that diagram +uh the other thing i need is you know + + align:start position:0% +uh the other thing i need is you know + + + align:start position:0% +uh the other thing i need is you know +what is r what is big r how big is it + + align:start position:0% +what is r what is big r how big is it + + + align:start position:0% +what is r what is big r how big is it +well it's obviously going to depend on + + align:start position:0% +well it's obviously going to depend on + + + align:start position:0% +well it's obviously going to depend on +how far out of focus i am so it's going + + align:start position:0% +how far out of focus i am so it's going + + + align:start position:0% +how far out of focus i am so it's going +to depend on delta + + align:start position:0% +to depend on delta + + + align:start position:0% +to depend on delta +and it's going to depend on the size of + + align:start position:0% +and it's going to depend on the size of + + + align:start position:0% +and it's going to depend on the size of +the + + align:start position:0% + + + + align:start position:0% + +lens + + align:start position:0% +lens + + + align:start position:0% +lens +something like that + + align:start position:0% + + + + align:start position:0% + +right this is just similar triangles + + align:start position:0% +right this is just similar triangles + + + align:start position:0% +right this is just similar triangles +again + + align:start position:0% + + + + align:start position:0% + +okay um + + align:start position:0% +okay um + + + align:start position:0% +okay um +oh a f uh which is this distance here + + align:start position:0% +oh a f uh which is this distance here + + + align:start position:0% +oh a f uh which is this distance here +from the lens to the uh image in focus + + align:start position:0% +from the lens to the uh image in focus + + + align:start position:0% +from the lens to the uh image in focus +image plane + + align:start position:0% + + + + align:start position:0% + +okay so obviously as i go more out of + + align:start position:0% +okay so obviously as i go more out of + + + align:start position:0% +okay so obviously as i go more out of +focus as i move the image plane + + align:start position:0% +focus as i move the image plane + + + align:start position:0% +focus as i move the image plane +further up this radius gets bigger + + align:start position:0% +further up this radius gets bigger + + + align:start position:0% +further up this radius gets bigger +and the brightness gets less because i'm + + align:start position:0% +and the brightness gets less because i'm + + + align:start position:0% +and the brightness gets less because i'm +now putting the same energy into into a + + align:start position:0% +now putting the same energy into into a + + + align:start position:0% +now putting the same energy into into a +larger area + + align:start position:0% +larger area + + + align:start position:0% +larger area +and so this is uh called the point + + align:start position:0% +and so this is uh called the point + + + align:start position:0% +and so this is uh called the point +spread function + + align:start position:0% +spread function + + + align:start position:0% +spread function +psf point spread function for this + + align:start position:0% +psf point spread function for this + + + align:start position:0% +psf point spread function for this +system when it's out of focus + + align:start position:0% +system when it's out of focus + + + align:start position:0% +system when it's out of focus +and + + align:start position:0% +and + + + align:start position:0% +and +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +this is used a lot + + align:start position:0% +this is used a lot + + + align:start position:0% +this is used a lot +in understanding + + align:start position:0% +in understanding + + + align:start position:0% +in understanding +the effect of being out of focus you + + align:start position:0% +the effect of being out of focus you + + + align:start position:0% +the effect of being out of focus you +know we think of it as blurring and of + + align:start position:0% +know we think of it as blurring and of + + + align:start position:0% +know we think of it as blurring and of +course we can think of it in terms of + + align:start position:0% +course we can think of it in terms of + + + align:start position:0% +course we can think of it in terms of +the fourier transform in terms of + + align:start position:0% +the fourier transform in terms of + + + align:start position:0% +the fourier transform in terms of +removing some or suppressing higher + + align:start position:0% +removing some or suppressing higher + + + align:start position:0% +removing some or suppressing higher +frequency content + + align:start position:0% +frequency content + + + align:start position:0% +frequency content +and it's the higher frequency content + + align:start position:0% +and it's the higher frequency content + + + align:start position:0% +and it's the higher frequency content +that makes things look + + align:start position:0% +that makes things look + + + align:start position:0% +that makes things look +sharp + + align:start position:0% +sharp + + + align:start position:0% +sharp +and + + align:start position:0% +and + + + align:start position:0% +and +in our case blurs the edge so let's see + + align:start position:0% +in our case blurs the edge so let's see + + + align:start position:0% +in our case blurs the edge so let's see +what the effect is on on the edge + + align:start position:0% + + + + align:start position:0% + +well basically + + align:start position:0% +well basically + + + align:start position:0% +well basically +we're going to + + align:start position:0% +we're going to + + + align:start position:0% +we're going to +have a response which we can calculate + + align:start position:0% +have a response which we can calculate + + + align:start position:0% +have a response which we can calculate +geometrically by superimposing the edge + + align:start position:0% +geometrically by superimposing the edge + + + align:start position:0% +geometrically by superimposing the edge +and the circle + + align:start position:0% + + + + align:start position:0% + +so let's take a simplest case where + + align:start position:0% +so let's take a simplest case where + + + align:start position:0% +so let's take a simplest case where +you know there's black on one side of + + align:start position:0% +you know there's black on one side of + + + align:start position:0% +you know there's black on one side of +the edge and white on the other + + align:start position:0% +the edge and white on the other + + + align:start position:0% +the edge and white on the other +and um + + align:start position:0% +and um + + + align:start position:0% +and um +now + + align:start position:0% +now + + + align:start position:0% +now +we have a radio a circle of a certain + + align:start position:0% +we have a radio a circle of a certain + + + align:start position:0% +we have a radio a circle of a certain +radius + + align:start position:0% +radius + + + align:start position:0% +radius +and what are we looking at well we're + + align:start position:0% +and what are we looking at well we're + + + align:start position:0% +and what are we looking at well we're +looking at this overlap you know that's + + align:start position:0% +looking at this overlap you know that's + + + align:start position:0% +looking at this overlap you know that's +going to + + align:start position:0% +going to + + + align:start position:0% +going to +be what controls how bright + + align:start position:0% +be what controls how bright + + + align:start position:0% +be what controls how bright +things appear + + align:start position:0% +things appear + + + align:start position:0% +things appear +and then we're going to move this thing + + align:start position:0% +and then we're going to move this thing + + + align:start position:0% +and then we're going to move this thing +across the edge to see how the response + + align:start position:0% +across the edge to see how the response + + + align:start position:0% +across the edge to see how the response +varies so we take this disc and we slide + + align:start position:0% +varies so we take this disc and we slide + + + align:start position:0% +varies so we take this disc and we slide +it across and obviously until it touches + + align:start position:0% +it across and obviously until it touches + + + align:start position:0% +it across and obviously until it touches +nothing happens there's no output + + align:start position:0% +nothing happens there's no output + + + align:start position:0% +nothing happens there's no output +and also obviously once we get over here + + align:start position:0% +and also obviously once we get over here + + + align:start position:0% +and also obviously once we get over here +the output is constant it's one + + align:start position:0% +the output is constant it's one + + + align:start position:0% +the output is constant it's one +nothing more changes so there's a + + align:start position:0% +nothing more changes so there's a + + + align:start position:0% +nothing more changes so there's a +transition + + align:start position:0% +transition + + + align:start position:0% +transition +between + + align:start position:0% +between + + + align:start position:0% +between +x being + + align:start position:0% +x being + + + align:start position:0% +x being +minus r and x being plus r where there's + + align:start position:0% +minus r and x being plus r where there's + + + align:start position:0% +minus r and x being plus r where there's +some sort of change between zero and one + + align:start position:0% +some sort of change between zero and one + + + align:start position:0% +some sort of change between zero and one +and and that's what we're trying to + + align:start position:0% +and and that's what we're trying to + + + align:start position:0% +and and that's what we're trying to +calculate + + align:start position:0% +calculate + + + align:start position:0% +calculate +well unfortunately uh it's not + + align:start position:0% +well unfortunately uh it's not + + + align:start position:0% +well unfortunately uh it's not +quite that + + align:start position:0% +quite that + + + align:start position:0% +quite that +simple so + + align:start position:0% +simple so + + + align:start position:0% +simple so +we could just write the answer out by + + align:start position:0% +we could just write the answer out by + + + align:start position:0% +we could just write the answer out by +inspection but we can't get it this way + + align:start position:0% +inspection but we can't get it this way + + + align:start position:0% +inspection but we can't get it this way +okay you know + + align:start position:0% +okay you know + + + align:start position:0% +okay you know +there's probably a formula for a sector + + align:start position:0% +there's probably a formula for a sector + + + align:start position:0% +there's probably a formula for a sector +of a circle like that but i don't know + + align:start position:0% +of a circle like that but i don't know + + + align:start position:0% +of a circle like that but i don't know +what it is so + + align:start position:0% +what it is so + + + align:start position:0% +what it is so +let's do it uh using things we do know + + align:start position:0% +let's do it uh using things we do know + + + align:start position:0% +let's do it uh using things we do know +so + + align:start position:0% +so + + + align:start position:0% +so +a couple of things we know we know how + + align:start position:0% +a couple of things we know we know how + + + align:start position:0% +a couple of things we know we know how +to compute the area of a triangle well + + align:start position:0% +to compute the area of a triangle well + + + align:start position:0% +to compute the area of a triangle well +probably know several ways of computing + + align:start position:0% +probably know several ways of computing + + + align:start position:0% +probably know several ways of computing +the area of a triangle + + align:start position:0% +the area of a triangle + + + align:start position:0% +the area of a triangle +and we also know how to compute the area + + align:start position:0% +and we also know how to compute the area + + + align:start position:0% +and we also know how to compute the area +of a + + align:start position:0% +of a + + + align:start position:0% +of a +sector of a circle so + + align:start position:0% +sector of a circle so + + + align:start position:0% +sector of a circle so +let me draw + + align:start position:0% +let me draw + + + align:start position:0% +let me draw +that here + + align:start position:0% +that here + + + align:start position:0% +that here +so that + + align:start position:0% +so that + + + align:start position:0% +so that +that's the sector of the circle that's + + align:start position:0% +that's the sector of the circle that's + + + align:start position:0% +that's the sector of the circle that's +the triangle i'm looking at + + align:start position:0% +the triangle i'm looking at + + + align:start position:0% +the triangle i'm looking at +and it's obvious that the quantity i + + align:start position:0% +and it's obvious that the quantity i + + + align:start position:0% +and it's obvious that the quantity i +want is the difference + + align:start position:0% +want is the difference + + + align:start position:0% +want is the difference +right it's what's left over when i + + align:start position:0% +right it's what's left over when i + + + align:start position:0% +right it's what's left over when i +subtract that triangle from + + align:start position:0% +subtract that triangle from + + + align:start position:0% +subtract that triangle from +that + + align:start position:0% +that + + + align:start position:0% +that +area + + align:start position:0% +area + + + align:start position:0% +area +so + + align:start position:0% +so + + + align:start position:0% +so +this is r + + align:start position:0% + + + + align:start position:0% + +and i'm going to call this angle theta + + align:start position:0% + + + + align:start position:0% + +okay and + + align:start position:0% +okay and + + + align:start position:0% +okay and +this bran this thing here is obviously r + + align:start position:0% +this bran this thing here is obviously r + + + align:start position:0% +this bran this thing here is obviously r +squared minus x squared + + align:start position:0% + + + + align:start position:0% + +so x is the position + + align:start position:0% +so x is the position + + + align:start position:0% +so x is the position +x0 means that you're right on top of the + + align:start position:0% +x0 means that you're right on top of the + + + align:start position:0% +x0 means that you're right on top of the +edge that the circle is bisected by the + + align:start position:0% +edge that the circle is bisected by the + + + align:start position:0% +edge that the circle is bisected by the +edge and then x can get as large as plus + + align:start position:0% +edge and then x can get as large as plus + + + align:start position:0% +edge and then x can get as large as plus +r before it saturates or minus r before + + align:start position:0% +r before it saturates or minus r before + + + align:start position:0% +r before it saturates or minus r before +it saturates + + align:start position:0% +it saturates + + + align:start position:0% +it saturates +okay so the area of the + + align:start position:0% +okay so the area of the + + + align:start position:0% +okay so the area of the +sector is 2 r squared theta + + align:start position:0% +sector is 2 r squared theta + + + align:start position:0% +sector is 2 r squared theta +write this this sector here + + align:start position:0% +write this this sector here + + + align:start position:0% +write this this sector here +and we can check you know when theta is + + align:start position:0% +and we can check you know when theta is + + + align:start position:0% +and we can check you know when theta is +2 pi + + align:start position:0% +2 pi + + + align:start position:0% +2 pi +um hmm okay i guess oh this is theta can + + align:start position:0% +um hmm okay i guess oh this is theta can + + + align:start position:0% +um hmm okay i guess oh this is theta can +only get up to pi + + align:start position:0% +only get up to pi + + + align:start position:0% +only get up to pi +so uh we would get uh + + align:start position:0% +so uh we would get uh + + + align:start position:0% +so uh we would get uh +oh pi r squared how about + + align:start position:0% +oh pi r squared how about + + + align:start position:0% +oh pi r squared how about +let's check that again so theta is the + + align:start position:0% +let's check that again so theta is the + + + align:start position:0% +let's check that again so theta is the +half angle of the sector + + align:start position:0% +half angle of the sector + + + align:start position:0% +half angle of the sector +and so it can only get as large as pi + + align:start position:0% +and so it can only get as large as pi + + + align:start position:0% +and so it can only get as large as pi +and if it's equal to pi that means we've + + align:start position:0% +and if it's equal to pi that means we've + + + align:start position:0% +and if it's equal to pi that means we've +covered the whole circle and we should + + align:start position:0% +covered the whole circle and we should + + + align:start position:0% +covered the whole circle and we should +get the area of the circle which is pi r + + align:start position:0% +get the area of the circle which is pi r + + + align:start position:0% +get the area of the circle which is pi r +squared right so okay so we get r + + align:start position:0% +squared right so okay so we get r + + + align:start position:0% +squared right so okay so we get r +squared theta + + align:start position:0% +squared theta + + + align:start position:0% +squared theta +and then we have to subtract from that + + align:start position:0% +and then we have to subtract from that + + + align:start position:0% +and then we have to subtract from that +the + + align:start position:0% +the + + + align:start position:0% +the +triangle area + + align:start position:0% +triangle area + + + align:start position:0% +triangle area +which is + + align:start position:0% + + + + align:start position:0% + +right it's the + + align:start position:0% +right it's the + + + align:start position:0% +right it's the +half the base times the height + + align:start position:0% +half the base times the height + + + align:start position:0% +half the base times the height +so the base is uh + + align:start position:0% +so the base is uh + + + align:start position:0% +so the base is uh +two times this quantity + + align:start position:0% +two times this quantity + + + align:start position:0% +two times this quantity +right because this quantity is just that + + align:start position:0% +right because this quantity is just that + + + align:start position:0% +right because this quantity is just that +section so that's the base and then the + + align:start position:0% +section so that's the base and then the + + + align:start position:0% +section so that's the base and then the +height is x + + align:start position:0% +height is x + + + align:start position:0% +height is x +and so half base times height gives me + + align:start position:0% +and so half base times height gives me + + + align:start position:0% +and so half base times height gives me +that and + + align:start position:0% +that and + + + align:start position:0% +that and +[Music] + + align:start position:0% + + + + align:start position:0% + +theta is + + align:start position:0% + + + + align:start position:0% + +given by this quantity + + align:start position:0% +given by this quantity + + + align:start position:0% +given by this quantity +and so i end up with + + align:start position:0% + + + + align:start position:0% + +i mean the + + align:start position:0% +i mean the + + + align:start position:0% +i mean the +the details aren't too exciting here + + align:start position:0% +the details aren't too exciting here + + + align:start position:0% +the details aren't too exciting here +i'm not going to expect you to remember + + align:start position:0% +i'm not going to expect you to remember + + + align:start position:0% +i'm not going to expect you to remember +this + + align:start position:0% +this + + + align:start position:0% +this +but we can plot that + + align:start position:0% +but we can plot that + + + align:start position:0% +but we can plot that +and + + align:start position:0% +and + + + align:start position:0% +and +see what sort of transition it gives us + + align:start position:0% +see what sort of transition it gives us + + + align:start position:0% +see what sort of transition it gives us +and what's more we can then feed it into + + align:start position:0% +and what's more we can then feed it into + + + align:start position:0% +and what's more we can then feed it into +this algorithm of this pattern to see + + align:start position:0% +this algorithm of this pattern to see + + + align:start position:0% +this algorithm of this pattern to see +how accurately it will determine the + + align:start position:0% +how accurately it will determine the + + + align:start position:0% +how accurately it will determine the +edge position and in particular we can + + align:start position:0% +edge position and in particular we can + + + align:start position:0% +edge position and in particular we can +plot the diagram that i just erased here + + align:start position:0% +plot the diagram that i just erased here + + + align:start position:0% +plot the diagram that i just erased here +which had s versus s bar + + align:start position:0% +which had s versus s bar + + + align:start position:0% +which had s versus s bar +right we in other words if this is how + + align:start position:0% +right we in other words if this is how + + + align:start position:0% +right we in other words if this is how +the edge is formed if this is why the + + align:start position:0% +the edge is formed if this is why the + + + align:start position:0% +the edge is formed if this is why the +edge has that smooth transition then + + align:start position:0% +edge has that smooth transition then + + + align:start position:0% +edge has that smooth transition then +this will allow me to calculate + + align:start position:0% +this will allow me to calculate + + + align:start position:0% +this will allow me to calculate +the error + + align:start position:0% +the error + + + align:start position:0% +the error +and the error ought to be pretty small + + align:start position:0% +and the error ought to be pretty small + + + align:start position:0% +and the error ought to be pretty small +but it's non-zero and if you want high + + align:start position:0% +but it's non-zero and if you want high + + + align:start position:0% +but it's non-zero and if you want high +accuracy you have to take it into + + align:start position:0% +accuracy you have to take it into + + + align:start position:0% +accuracy you have to take it into +account + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +another way of looking at this is to + + align:start position:0% +another way of looking at this is to + + + align:start position:0% +another way of looking at this is to +plot this diagram so + + align:start position:0% + + + + align:start position:0% + +so so where does that come from that + + align:start position:0% +so so where does that come from that + + + align:start position:0% +so so where does that come from that +that looks like a circle except it's um + + align:start position:0% +that looks like a circle except it's um + + + align:start position:0% +that looks like a circle except it's um +elliptical because it's been + + align:start position:0% +elliptical because it's been + + + align:start position:0% +elliptical because it's been +increased in height by two + + align:start position:0% +increased in height by two + + + align:start position:0% +increased in height by two +well if you think about it + + align:start position:0% +well if you think about it + + + align:start position:0% +well if you think about it +when i move this + + align:start position:0% +when i move this + + + align:start position:0% +when i move this +uh edge or the circle + + align:start position:0% +uh edge or the circle + + + align:start position:0% +uh edge or the circle +then i am + + align:start position:0% +then i am + + + align:start position:0% +then i am +adding or subtracting + + align:start position:0% +adding or subtracting + + + align:start position:0% +adding or subtracting +an area you know infinitesimal area + + align:start position:0% +an area you know infinitesimal area + + + align:start position:0% +an area you know infinitesimal area +that has a height equal to this quantity + + align:start position:0% +that has a height equal to this quantity + + + align:start position:0% +that has a height equal to this quantity +well + + align:start position:0% +well + + + align:start position:0% +well +in other words just you know twice the + + align:start position:0% +in other words just you know twice the + + + align:start position:0% +in other words just you know twice the +height of the circle there + + align:start position:0% +height of the circle there + + + align:start position:0% +height of the circle there +so actually + + align:start position:0% +so actually + + + align:start position:0% +so actually +i don't need for some purpose i don't + + align:start position:0% +i don't need for some purpose i don't + + + align:start position:0% +i don't need for some purpose i don't +need to do all that hairy math i can + + align:start position:0% +need to do all that hairy math i can + + + align:start position:0% +need to do all that hairy math i can +just look at that diagram and + + align:start position:0% +just look at that diagram and + + + align:start position:0% +just look at that diagram and +immediately write down uh + + align:start position:0% + + + + align:start position:0% + +that the + + align:start position:0% + + + + align:start position:0% + +brightness derivative is that and and oh + + align:start position:0% +brightness derivative is that and and oh + + + align:start position:0% +brightness derivative is that and and oh +it has a peak at zero well + + align:start position:0% +it has a peak at zero well + + + align:start position:0% +it has a peak at zero well +we expect that + + align:start position:0% +we expect that + + + align:start position:0% +we expect that +okay + + align:start position:0% + + + + align:start position:0% + +while i'm here i can look at the second + + align:start position:0% +while i'm here i can look at the second + + + align:start position:0% +while i'm here i can look at the second +derivative + + align:start position:0% +derivative + + + align:start position:0% +derivative +and it + + align:start position:0% + + + + align:start position:0% + +looks like that and it's x over + + align:start position:0% +looks like that and it's x over + + + align:start position:0% +looks like that and it's x over +minus + + align:start position:0% + + + + align:start position:0% + +it's just the derivative of that which + + align:start position:0% +it's just the derivative of that which + + + align:start position:0% +it's just the derivative of that which +is pretty easy but + + align:start position:0% +is pretty easy but + + + align:start position:0% +is pretty easy but +what's e + + align:start position:0% +what's e + + + align:start position:0% +what's e +well it's the integral of this thing + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% + + + + align:start position:0% + +and we we just + + align:start position:0% +and we we just + + + align:start position:0% +and we we just +we just did that integral + + align:start position:0% +we just did that integral + + + align:start position:0% +we just did that integral +in a somewhat painful way but but it's + + align:start position:0% +in a somewhat painful way but but it's + + + align:start position:0% +in a somewhat painful way but but it's +probably just as well because i don't + + align:start position:0% +probably just as well because i don't + + + align:start position:0% +probably just as well because i don't +remember what the integral of that is + + align:start position:0% +remember what the integral of that is + + + align:start position:0% +remember what the integral of that is +and you know + + align:start position:0% +and you know + + + align:start position:0% +and you know +there it is + + align:start position:0% +there it is + + + align:start position:0% +there it is +i think okay + + align:start position:0% +i think okay + + + align:start position:0% +i think okay +okay so uh what can we do with this we + + align:start position:0% +okay so uh what can we do with this we + + + align:start position:0% +okay so uh what can we do with this we +can now feed this into the algorithm and + + align:start position:0% +can now feed this into the algorithm and + + + align:start position:0% +can now feed this into the algorithm and +say + + align:start position:0% +say + + + align:start position:0% +say +if this is how + + align:start position:0% +if this is how + + + align:start position:0% +if this is how +why the edges smoothly varying because + + align:start position:0% +why the edges smoothly varying because + + + align:start position:0% +why the edges smoothly varying because +it's out of focus then + + align:start position:0% +it's out of focus then + + + align:start position:0% +it's out of focus then +this is the relationship between the + + align:start position:0% +this is the relationship between the + + + align:start position:0% +this is the relationship between the +true position of the edge and the one i + + align:start position:0% +true position of the edge and the one i + + + align:start position:0% +true position of the edge and the one i +compute by say using the + + align:start position:0% +compute by say using the + + + align:start position:0% +compute by say using the +the parabola argument and therefore i + + align:start position:0% +the parabola argument and therefore i + + + align:start position:0% +the parabola argument and therefore i +can compensate for it + + align:start position:0% +can compensate for it + + + align:start position:0% +can compensate for it +now of course in a real imaging + + align:start position:0% +now of course in a real imaging + + + align:start position:0% +now of course in a real imaging +situation there'll be more than just the + + align:start position:0% +situation there'll be more than just the + + + align:start position:0% +situation there'll be more than just the +defocus of the lens so uh it probably uh + + align:start position:0% +defocus of the lens so uh it probably uh + + + align:start position:0% +defocus of the lens so uh it probably uh +doesn't pay to be too + + align:start position:0% +doesn't pay to be too + + + align:start position:0% +doesn't pay to be too +too careful about this + + align:start position:0% +too careful about this + + + align:start position:0% +too careful about this +okay now um + + align:start position:0% +okay now um + + + align:start position:0% +okay now um +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +suppose that you're a patent infringer + + align:start position:0% +suppose that you're a patent infringer + + + align:start position:0% +suppose that you're a patent infringer +or you're trying to infringe this + + align:start position:0% +or you're trying to infringe this + + + align:start position:0% +or you're trying to infringe this +pattern + + align:start position:0% + + + + align:start position:0% + +then + + align:start position:0% +then + + + align:start position:0% +then +there are a number of ways to go + + align:start position:0% +there are a number of ways to go + + + align:start position:0% +there are a number of ways to go +basically you look at the uh + + align:start position:0% + + + + align:start position:0% + +components of each claim and you see if + + align:start position:0% +components of each claim and you see if + + + align:start position:0% +components of each claim and you see if +there's one of the components that maybe + + align:start position:0% +there's one of the components that maybe + + + align:start position:0% +there's one of the components that maybe +you can + + align:start position:0% +you can + + + align:start position:0% +you can +avoid maybe you can do it in a different + + align:start position:0% +avoid maybe you can do it in a different + + + align:start position:0% +avoid maybe you can do it in a different +way or maybe you can do it in a better + + align:start position:0% +way or maybe you can do it in a better + + + align:start position:0% +way or maybe you can do it in a better +way + + align:start position:0% +way + + + align:start position:0% +way +just arguing whether something's better + + align:start position:0% +just arguing whether something's better + + + align:start position:0% +just arguing whether something's better +or not uh doesn't + + align:start position:0% +or not uh doesn't + + + align:start position:0% +or not uh doesn't +help it's it has to be different + + align:start position:0% +help it's it has to be different + + + align:start position:0% +help it's it has to be different +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and now there's some some things here + + align:start position:0% +and now there's some some things here + + + align:start position:0% +and now there's some some things here +that aren't that uh pleasant one of them + + align:start position:0% +that aren't that uh pleasant one of them + + + align:start position:0% +that aren't that uh pleasant one of them +is this quantization of gradient + + align:start position:0% +is this quantization of gradient + + + align:start position:0% +is this quantization of gradient +directions and the reason it's not that + + align:start position:0% +directions and the reason it's not that + + + align:start position:0% +directions and the reason it's not that +great is because it introduces + + align:start position:0% +great is because it introduces + + + align:start position:0% +great is because it introduces +the awkwardness that the spacing is + + align:start position:0% +the awkwardness that the spacing is + + + align:start position:0% +the awkwardness that the spacing is +comes in two sizes you know pixel + + align:start position:0% +comes in two sizes you know pixel + + + align:start position:0% +comes in two sizes you know pixel +spacing and square root of two times + + align:start position:0% +spacing and square root of two times + + + align:start position:0% +spacing and square root of two times +pixel spacing and these these effects of + + align:start position:0% +pixel spacing and these these effects of + + + align:start position:0% +pixel spacing and these these effects of +defocus etc + + align:start position:0% +defocus etc + + + align:start position:0% +defocus etc +are they are on pixel grid they're in + + align:start position:0% +are they are on pixel grid they're in + + + align:start position:0% +are they are on pixel grid they're in +units of pixel spacing and so now we're + + align:start position:0% +units of pixel spacing and so now we're + + + align:start position:0% +units of pixel spacing and so now we're +sampling it in two different ways so we + + align:start position:0% +sampling it in two different ways so we + + + align:start position:0% +sampling it in two different ways so we +expect to get a slightly different error + + align:start position:0% +expect to get a slightly different error + + + align:start position:0% +expect to get a slightly different error +contribution so how can we avoid that + + align:start position:0% +contribution so how can we avoid that + + + align:start position:0% +contribution so how can we avoid that +so here are a couple of ways of + + align:start position:0% + + + + align:start position:0% + +so the idea is we don't want + + align:start position:0% +so the idea is we don't want + + + align:start position:0% +so the idea is we don't want +quantized + + align:start position:0% +quantized + + + align:start position:0% +quantized +gradient directions + + align:start position:0% + + + + align:start position:0% + +and so suppose our gradient is + + align:start position:0% + + + + align:start position:0% + +now + + align:start position:0% +now + + + align:start position:0% +now +if we follow the + + align:start position:0% +if we follow the + + + align:start position:0% +if we follow the +the preferred method in the patent + + align:start position:0% +the preferred method in the patent + + + align:start position:0% +the preferred method in the patent +again notice that that method doesn't + + align:start position:0% +again notice that that method doesn't + + + align:start position:0% +again notice that that method doesn't +show up in any of the claims it's so + + align:start position:0% +show up in any of the claims it's so + + + align:start position:0% +show up in any of the claims it's so +which is good because that means that + + align:start position:0% +which is good because that means that + + + align:start position:0% +which is good because that means that +you could easily + + align:start position:0% +you could easily + + + align:start position:0% +you could easily +circumvent the patent but + + align:start position:0% +circumvent the patent but + + + align:start position:0% +circumvent the patent but +it is the preferred method that's shown + + align:start position:0% +it is the preferred method that's shown + + + align:start position:0% +it is the preferred method that's shown +in in the specification + + align:start position:0% +in in the specification + + + align:start position:0% +in in the specification +then we would quantize this and we would + + align:start position:0% +then we would quantize this and we would + + + align:start position:0% +then we would quantize this and we would +work with + + align:start position:0% +work with + + + align:start position:0% +work with +the diagonal + + align:start position:0% +the diagonal + + + align:start position:0% +the diagonal +but let's instead say well how about + + align:start position:0% +but let's instead say well how about + + + align:start position:0% +but let's instead say well how about +this how about + + align:start position:0% +this how about + + + align:start position:0% +this how about +if i figured out what the if i knew what + + align:start position:0% +if i figured out what the if i knew what + + + align:start position:0% +if i figured out what the if i knew what +the value was there + + align:start position:0% +the value was there + + + align:start position:0% +the value was there +i know what the value is here + + align:start position:0% +i know what the value is here + + + align:start position:0% +i know what the value is here +you know how about this arrangement so + + align:start position:0% +you know how about this arrangement so + + + align:start position:0% +you know how about this arrangement so +this could be g0 and that's g plus and + + align:start position:0% +this could be g0 and that's g plus and + + + align:start position:0% +this could be g0 and that's g plus and +that's g minus + + align:start position:0% +that's g minus + + + align:start position:0% +that's g minus +then i would avoid the quantization of + + align:start position:0% +then i would avoid the quantization of + + + align:start position:0% +then i would avoid the quantization of +gradient direction + + align:start position:0% + + + + align:start position:0% + +and how do i do that well i only know + + align:start position:0% +and how do i do that well i only know + + + align:start position:0% +and how do i do that well i only know +the values on the actual pixel grid + + align:start position:0% +the values on the actual pixel grid + + + align:start position:0% +the values on the actual pixel grid +and so tada i interpolate + + align:start position:0% + + + + align:start position:0% + +so i use interpolation to go from the + + align:start position:0% +so i use interpolation to go from the + + + align:start position:0% +so i use interpolation to go from the +values on the grid to the value over + + align:start position:0% +values on the grid to the value over + + + align:start position:0% +values on the grid to the value over +here + + align:start position:0% +here + + + align:start position:0% +here +and because i'm interpolating along this + + align:start position:0% +and because i'm interpolating along this + + + align:start position:0% +and because i'm interpolating along this +line i can actually easily just use uh + + align:start position:0% +line i can actually easily just use uh + + + align:start position:0% +line i can actually easily just use uh +one 1d linear interpolation + + align:start position:0% +one 1d linear interpolation + + + align:start position:0% +one 1d linear interpolation +right so + + align:start position:0% +right so + + + align:start position:0% +right so +how does that work well if i have a + + align:start position:0% +how does that work well if i have a + + + align:start position:0% +how does that work well if i have a +function + + align:start position:0% +function + + + align:start position:0% +function +[Music] + + align:start position:0% + + + + align:start position:0% + +then i can say well + + align:start position:0% +then i can say well + + + align:start position:0% +then i can say well +i know the value here another value + + align:start position:0% +i know the value here another value + + + align:start position:0% +i know the value here another value +there and let's say it's a straight line + + align:start position:0% +there and let's say it's a straight line + + + align:start position:0% +there and let's say it's a straight line +in between and then the formula for this + + align:start position:0% +in between and then the formula for this + + + align:start position:0% +in between and then the formula for this +is + + align:start position:0% + + + + align:start position:0% + +i mean you can + + align:start position:0% +i mean you can + + + align:start position:0% +i mean you can +come up with that yourself but you can + + align:start position:0% +come up with that yourself but you can + + + align:start position:0% +come up with that yourself but you can +easily check it first of all it's linear + + align:start position:0% +easily check it first of all it's linear + + + align:start position:0% +easily check it first of all it's linear +in x + + align:start position:0% +in x + + + align:start position:0% +in x +and then at x equals a + + align:start position:0% +and then at x equals a + + + align:start position:0% +and then at x equals a +we get only this + + align:start position:0% +we get only this + + + align:start position:0% +we get only this +term and the b minus a + + align:start position:0% +term and the b minus a + + + align:start position:0% +term and the b minus a +cancels the b minus a and at x equals b + + align:start position:0% +cancels the b minus a and at x equals b + + + align:start position:0% +cancels the b minus a and at x equals b +uh this term drops out so we only have + + align:start position:0% +uh this term drops out so we only have + + + align:start position:0% +uh this term drops out so we only have +that and again the b minus a can okay so + + align:start position:0% +that and again the b minus a can okay so + + + align:start position:0% +that and again the b minus a can okay so +it's easy to do that in in 1d and of + + align:start position:0% +it's easy to do that in in 1d and of + + + align:start position:0% +it's easy to do that in in 1d and of +course you can extend that to so-called + + align:start position:0% +course you can extend that to so-called + + + align:start position:0% +course you can extend that to so-called +bilinear interpolation in in 2d + + align:start position:0% +bilinear interpolation in in 2d + + + align:start position:0% +bilinear interpolation in in 2d +but we don't actually even need that + + align:start position:0% +but we don't actually even need that + + + align:start position:0% +but we don't actually even need that +here + + align:start position:0% +here + + + align:start position:0% +here +okay so then + + align:start position:0% + + + + align:start position:0% + +we + + align:start position:0% +we + + + align:start position:0% +we +approximate the value here by + + align:start position:0% +approximate the value here by + + + align:start position:0% +approximate the value here by +interpolation and we can use more + + align:start position:0% +interpolation and we can use more + + + align:start position:0% +interpolation and we can use more +sophisticated methods + + align:start position:0% +sophisticated methods + + + align:start position:0% +sophisticated methods +of interpolation for example we can use + + align:start position:0% +of interpolation for example we can use + + + align:start position:0% +of interpolation for example we can use +cubic spline interpolation + + align:start position:0% +cubic spline interpolation + + + align:start position:0% +cubic spline interpolation +which we won't talk about here but + + align:start position:0% +which we won't talk about here but + + + align:start position:0% +which we won't talk about here but +it uh + + align:start position:0% +it uh + + + align:start position:0% +it uh +you know involves more points but gives + + align:start position:0% +you know involves more points but gives + + + align:start position:0% +you know involves more points but gives +you + + align:start position:0% +you + + + align:start position:0% +you +an interpolation that's a smooth cubic + + align:start position:0% +an interpolation that's a smooth cubic + + + align:start position:0% +an interpolation that's a smooth cubic +curve which in some cases is more + + align:start position:0% +curve which in some cases is more + + + align:start position:0% +curve which in some cases is more +accurate + + align:start position:0% +accurate + + + align:start position:0% +accurate +okay and then we perform whatever we did + + align:start position:0% +okay and then we perform whatever we did + + + align:start position:0% +okay and then we perform whatever we did +and we end up you know somewhere there + + align:start position:0% +and we end up you know somewhere there + + + align:start position:0% +and we end up you know somewhere there +and + + align:start position:0% +and + + + align:start position:0% +and +we we don't need the uh plane position + + align:start position:0% +we we don't need the uh plane position + + + align:start position:0% +we we don't need the uh plane position +step because we're actually on the + + align:start position:0% +step because we're actually on the + + + align:start position:0% +step because we're actually on the +gradient direction we're exactly where + + align:start position:0% +gradient direction we're exactly where + + + align:start position:0% +gradient direction we're exactly where +you want to be + + align:start position:0% +you want to be + + + align:start position:0% +you want to be +so + + align:start position:0% +so + + + align:start position:0% +so +um that + + align:start position:0% +um that + + + align:start position:0% +um that +you know you wonder why why didn't they + + align:start position:0% +you know you wonder why why didn't they + + + align:start position:0% +you know you wonder why why didn't they +do that + + align:start position:0% +do that + + + align:start position:0% +do that +well uh + + align:start position:0% +well uh + + + align:start position:0% +well uh +they don't say it but + + align:start position:0% +they don't say it but + + + align:start position:0% +they don't say it but +uh + + align:start position:0% +uh + + + align:start position:0% +uh +two two reasons one that i can think of + + align:start position:0% +two two reasons one that i can think of + + + align:start position:0% +two two reasons one that i can think of +one is that before we complained because + + align:start position:0% +one is that before we complained because + + + align:start position:0% +one is that before we complained because +sometimes we were using pixel spacing + + align:start position:0% +sometimes we were using pixel spacing + + + align:start position:0% +sometimes we were using pixel spacing +and sometimes square root of two times + + align:start position:0% +and sometimes square root of two times + + + align:start position:0% +and sometimes square root of two times +pixel spacing well now we can have + + align:start position:0% +pixel spacing well now we can have + + + align:start position:0% +pixel spacing well now we can have +anything in between + + align:start position:0% +anything in between + + + align:start position:0% +anything in between +not not just those two values and that + + align:start position:0% +not not just those two values and that + + + align:start position:0% +not not just those two values and that +correction graph the bias graph + + align:start position:0% +correction graph the bias graph + + + align:start position:0% +correction graph the bias graph +you know will be different for all of + + align:start position:0% +you know will be different for all of + + + align:start position:0% +you know will be different for all of +those values so you've got to i don't + + align:start position:0% +those values so you've got to i don't + + + align:start position:0% +those values so you've got to i don't +know quantize it + + align:start position:0% +know quantize it + + + align:start position:0% +know quantize it +build a lookup table + + align:start position:0% +build a lookup table + + + align:start position:0% +build a lookup table +no no not insurmountable problems but an + + align:start position:0% +no no not insurmountable problems but an + + + align:start position:0% +no no not insurmountable problems but an +extra hassle and you wonder you know is + + align:start position:0% +extra hassle and you wonder you know is + + + align:start position:0% +extra hassle and you wonder you know is +it worth it + + align:start position:0% +it worth it + + + align:start position:0% +it worth it +so that's one reason + + align:start position:0% +so that's one reason + + + align:start position:0% +so that's one reason +you might not choose this the other + + align:start position:0% +you might not choose this the other + + + align:start position:0% +you might not choose this the other +reason is that + + align:start position:0% +reason is that + + + align:start position:0% +reason is that +you did an interpolation + + align:start position:0% +you did an interpolation + + + align:start position:0% +you did an interpolation +and how accurate is that + + align:start position:0% +and how accurate is that + + + align:start position:0% +and how accurate is that +you know you've gone away from the + + align:start position:0% +you know you've gone away from the + + + align:start position:0% +you know you've gone away from the +values that you actually know for sure + + align:start position:0% +values that you actually know for sure + + + align:start position:0% +values that you actually know for sure +to something that you interpolated using + + align:start position:0% +to something that you interpolated using + + + align:start position:0% +to something that you interpolated using +a method that you chose in some + + align:start position:0% +a method that you chose in some + + + align:start position:0% +a method that you chose in some +arbitrary fashion you know how good is + + align:start position:0% +arbitrary fashion you know how good is + + + align:start position:0% +arbitrary fashion you know how good is +it so that that'll introduce some error + + align:start position:0% +it so that that'll introduce some error + + + align:start position:0% +it so that that'll introduce some error +as well now in many cases that error + + align:start position:0% +as well now in many cases that error + + + align:start position:0% +as well now in many cases that error +wouldn't matter it'd be so small + + align:start position:0% +wouldn't matter it'd be so small + + + align:start position:0% +wouldn't matter it'd be so small +but you know if you're going for a 40th + + align:start position:0% +but you know if you're going for a 40th + + + align:start position:0% +but you know if you're going for a 40th +of a pixel accuracy + + align:start position:0% +of a pixel accuracy + + + align:start position:0% +of a pixel accuracy +that even that small error can be + + align:start position:0% +that even that small error can be + + + align:start position:0% +that even that small error can be +significant + + align:start position:0% +significant + + + align:start position:0% +significant +okay so that's one + + align:start position:0% +okay so that's one + + + align:start position:0% +okay so that's one +one method uh one alternative and um + + align:start position:0% + + + + align:start position:0% + +one of its problems is + + align:start position:0% +one of its problems is + + + align:start position:0% +one of its problems is +uh changing size of this step + + align:start position:0% +uh changing size of this step + + + align:start position:0% +uh changing size of this step +uh from a pixel to square root of two + + align:start position:0% +uh from a pixel to square root of two + + + align:start position:0% +uh from a pixel to square root of two +well what if we + + align:start position:0% +well what if we + + + align:start position:0% +well what if we +get rid of that and we just have a fixed + + align:start position:0% +get rid of that and we just have a fixed + + + align:start position:0% +get rid of that and we just have a fixed +size so + + align:start position:0% +size so + + + align:start position:0% +size so +here's again our + + align:start position:0% +here's again our + + + align:start position:0% +here's again our +pixel grid we know the values at all of + + align:start position:0% +pixel grid we know the values at all of + + + align:start position:0% +pixel grid we know the values at all of +the intersections of these lines + + align:start position:0% +the intersections of these lines + + + align:start position:0% +the intersections of these lines +and this is g0 + + align:start position:0% +and this is g0 + + + align:start position:0% +and this is g0 +and now we say well let's just draw a + + align:start position:0% +and now we say well let's just draw a + + + align:start position:0% +and now we say well let's just draw a +circle + + align:start position:0% + + + + align:start position:0% + +and again we'll pick the + + align:start position:0% +and again we'll pick the + + + align:start position:0% +and again we'll pick the +we'll pick some gradient direction + + align:start position:0% + + + + align:start position:0% + +and now + + align:start position:0% + + + + align:start position:0% + +we + + align:start position:0% + + + + align:start position:0% + +use that value + + align:start position:0% +use that value + + + align:start position:0% +use that value +and that value and that value and those + + align:start position:0% +and that value and that value and those + + + align:start position:0% +and that value and that value and those +are + + align:start position:0% +are + + + align:start position:0% +are +equally spaced they're always the same + + align:start position:0% +equally spaced they're always the same + + + align:start position:0% +equally spaced they're always the same +distance from each other + + align:start position:0% +distance from each other + + + align:start position:0% +distance from each other +no matter what the gradient direction so + + align:start position:0% +no matter what the gradient direction so + + + align:start position:0% +no matter what the gradient direction so +i've kind of now dealt with two issues + + align:start position:0% +i've kind of now dealt with two issues + + + align:start position:0% +i've kind of now dealt with two issues +the one is there's no quantization of + + align:start position:0% +the one is there's no quantization of + + + align:start position:0% +the one is there's no quantization of +the gradient direction + + align:start position:0% +the gradient direction + + + align:start position:0% +the gradient direction +and there's none of this change of the + + align:start position:0% +and there's none of this change of the + + + align:start position:0% +and there's none of this change of the +you know what does s equals one mean + + align:start position:0% +you know what does s equals one mean + + + align:start position:0% +you know what does s equals one mean +uh before that could take on two values + + align:start position:0% +uh before that could take on two values + + + align:start position:0% +uh before that could take on two values +and over here it could take on a range + + align:start position:0% +and over here it could take on a range + + + align:start position:0% +and over here it could take on a range +of values well here it's always the same + + align:start position:0% +of values well here it's always the same + + + align:start position:0% +of values well here it's always the same +it's it's the the pixel spacing + + align:start position:0% + + + + align:start position:0% + +okay so + + align:start position:0% +okay so + + + align:start position:0% +okay so +of course i don't know the value here so + + align:start position:0% +of course i don't know the value here so + + + align:start position:0% +of course i don't know the value here so +i have to use interpolation which is now + + align:start position:0% +i have to use interpolation which is now + + + align:start position:0% +i have to use interpolation which is now +a 2d interpolation + + align:start position:0% + + + + align:start position:0% + +and so i can use bilinear + + align:start position:0% + + + + align:start position:0% + +or i could for example use bicubic + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +again you know why didn't they do this + + align:start position:0% +again you know why didn't they do this + + + align:start position:0% +again you know why didn't they do this +well it's extra work + + align:start position:0% +well it's extra work + + + align:start position:0% +well it's extra work +particularly with a bicubic we need to + + align:start position:0% +particularly with a bicubic we need to + + + align:start position:0% +particularly with a bicubic we need to +take into account more pixels than we + + align:start position:0% +take into account more pixels than we + + + align:start position:0% +take into account more pixels than we +have here + + align:start position:0% +have here + + + align:start position:0% +have here +you know go out + + align:start position:0% +you know go out + + + align:start position:0% +you know go out +to a five by five grid not just a three + + align:start position:0% +to a five by five grid not just a three + + + align:start position:0% +to a five by five grid not just a three +by three grid + + align:start position:0% +by three grid + + + align:start position:0% +by three grid +bilinear is not terribly accurate so we + + align:start position:0% +bilinear is not terribly accurate so we + + + align:start position:0% +bilinear is not terribly accurate so we +may not want to use that so + + align:start position:0% +may not want to use that so + + + align:start position:0% +may not want to use that so +anyway + + align:start position:0% +anyway + + + align:start position:0% +anyway +so you can see that + + align:start position:0% +so you can see that + + + align:start position:0% +so you can see that +even though + + align:start position:0% +even though + + + align:start position:0% +even though +a lot of things are described in the + + align:start position:0% +a lot of things are described in the + + + align:start position:0% +a lot of things are described in the +pattern there is also some hidden stuff + + align:start position:0% +pattern there is also some hidden stuff + + + align:start position:0% +pattern there is also some hidden stuff +going on they probably experimented with + + align:start position:0% +going on they probably experimented with + + + align:start position:0% +going on they probably experimented with +all of this and picked something that + + align:start position:0% +all of this and picked something that + + + align:start position:0% +all of this and picked something that +was + + align:start position:0% +was + + + align:start position:0% +was +very accurate and yet simple and that's + + align:start position:0% +very accurate and yet simple and that's + + + align:start position:0% +very accurate and yet simple and that's +how we got to that method + + align:start position:0% + + + + align:start position:0% + +now the last thing i want to talk about + + align:start position:0% +now the last thing i want to talk about + + + align:start position:0% +now the last thing i want to talk about +today is uh + + align:start position:0% +today is uh + + + align:start position:0% +today is uh +multiscale they do + + align:start position:0% +multiscale they do + + + align:start position:0% +multiscale they do +uh point out in this patent + + align:start position:0% +uh point out in this patent + + + align:start position:0% +uh point out in this patent +that you might want to do this at + + align:start position:0% +that you might want to do this at + + + align:start position:0% +that you might want to do this at +multiple scales + + align:start position:0% +multiple scales + + + align:start position:0% +multiple scales +they don't make a big fuss of it here + + align:start position:0% +they don't make a big fuss of it here + + + align:start position:0% +they don't make a big fuss of it here +but um + + align:start position:0% +but um + + + align:start position:0% +but um +um + + align:start position:0% +um + + + align:start position:0% +um +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +we already mentioned that that's + + align:start position:0% +we already mentioned that that's + + + align:start position:0% +we already mentioned that that's +something you want to do + + align:start position:0% +something you want to do + + + align:start position:0% +something you want to do +there are some edges which are very + + align:start position:0% +there are some edges which are very + + + align:start position:0% +there are some edges which are very +sharp and they will be best found at the + + align:start position:0% +sharp and they will be best found at the + + + align:start position:0% +sharp and they will be best found at the +highest resolution and then there's some + + align:start position:0% +highest resolution and then there's some + + + align:start position:0% +highest resolution and then there's some +other edges that are kind of blurry + + align:start position:0% +other edges that are kind of blurry + + + align:start position:0% +other edges that are kind of blurry +either because they're out of focus or + + align:start position:0% +either because they're out of focus or + + + align:start position:0% +either because they're out of focus or +because the object doesn't have a sharp + + align:start position:0% +because the object doesn't have a sharp + + + align:start position:0% +because the object doesn't have a sharp +transition you know if the object has a + + align:start position:0% +transition you know if the object has a + + + align:start position:0% +transition you know if the object has a +smoothly turning + + align:start position:0% +smoothly turning + + + align:start position:0% +smoothly turning +curvature then there'll be a transition + + align:start position:0% +curvature then there'll be a transition + + + align:start position:0% +curvature then there'll be a transition +in brightness from whatever the + + align:start position:0% +in brightness from whatever the + + + align:start position:0% +in brightness from whatever the +brightness is for one planar surface to + + align:start position:0% +brightness is for one planar surface to + + + align:start position:0% +brightness is for one planar surface to +the brightness for a different planar + + align:start position:0% +the brightness for a different planar + + + align:start position:0% +the brightness for a different planar +surface but they're all these in between + + align:start position:0% +surface but they're all these in between + + + align:start position:0% +surface but they're all these in between +values so the transition won't be on one + + align:start position:0% +values so the transition won't be on one + + + align:start position:0% +values so the transition won't be on one +pixel it'll be spread out + + align:start position:0% +pixel it'll be spread out + + + align:start position:0% +pixel it'll be spread out +over many pixels + + align:start position:0% +over many pixels + + + align:start position:0% +over many pixels +um + + align:start position:0% +um + + + align:start position:0% +um +see do i want to do this now or + + align:start position:0% +see do i want to do this now or + + + align:start position:0% +see do i want to do this now or +we haven't talked about chordic so um + + align:start position:0% +we haven't talked about chordic so um + + + align:start position:0% +we haven't talked about chordic so um +i'm just looking at time we don't have + + align:start position:0% +i'm just looking at time we don't have + + + align:start position:0% +i'm just looking at time we don't have +much time so when i why don't i do a + + align:start position:0% +much time so when i why don't i do a + + + align:start position:0% +much time so when i why don't i do a +codec + + align:start position:0% +codec + + + align:start position:0% +codec +so this was the method + + align:start position:0% +so this was the method + + + align:start position:0% +so this was the method +to go from e x e y to + + align:start position:0% +to go from e x e y to + + + align:start position:0% +to go from e x e y to +e zero + + align:start position:0% +e zero + + + align:start position:0% +e zero +e theta + + align:start position:0% +e theta + + + align:start position:0% +e theta +right where + + align:start position:0% +right where + + + align:start position:0% +right where +e zero e0 so it's just a cartesian to + + align:start position:0% +e zero e0 so it's just a cartesian to + + + align:start position:0% +e zero e0 so it's just a cartesian to +polar coordinate transformation + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +you know square roots and 810 + + align:start position:0% +you know square roots and 810 + + + align:start position:0% +you know square roots and 810 +take some computing you'd have to + + align:start position:0% +take some computing you'd have to + + + align:start position:0% +take some computing you'd have to +probably use a lookup table to speed + + align:start position:0% +probably use a lookup table to speed + + + align:start position:0% +probably use a lookup table to speed +that up so + + align:start position:0% +that up so + + + align:start position:0% +that up so +so uh + + align:start position:0% +so uh + + + align:start position:0% +so uh +what is their preferred uh + + align:start position:0% +what is their preferred uh + + + align:start position:0% +what is their preferred uh +implementation of this so the idea is + + align:start position:0% +implementation of this so the idea is + + + align:start position:0% +implementation of this so the idea is +that + + align:start position:0% +that + + + align:start position:0% +that +we rotate the coordinate system + + align:start position:0% +we rotate the coordinate system + + + align:start position:0% +we rotate the coordinate system +so we have + + align:start position:0% +so we have + + + align:start position:0% +so we have +we have + + align:start position:0% +we have + + + align:start position:0% +we have +we have some gradient + + align:start position:0% +we have some gradient + + + align:start position:0% +we have some gradient +e x e y + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +if we knew + + align:start position:0% +if we knew + + + align:start position:0% +if we knew +that angle then we could just rotate it + + align:start position:0% +that angle then we could just rotate it + + + align:start position:0% +that angle then we could just rotate it +down and then the length of it + + align:start position:0% +down and then the length of it + + + align:start position:0% +down and then the length of it +e x + + align:start position:0% +e x + + + align:start position:0% +e x +would be e0 + + align:start position:0% +would be e0 + + + align:start position:0% +would be e0 +and e y would be zero right so so we're + + align:start position:0% +and e y would be zero right so so we're + + + align:start position:0% +and e y would be zero right so so we're +aiming for where + + align:start position:0% +aiming for where + + + align:start position:0% +aiming for where +e + + align:start position:0% +e + + + align:start position:0% +e +zero is just e x prime + + align:start position:0% +zero is just e x prime + + + align:start position:0% +zero is just e x prime +and e theta e + + align:start position:0% + + + + align:start position:0% + +and e y + + align:start position:0% +and e y + + + align:start position:0% +and e y +prime is zero + + align:start position:0% +prime is zero + + + align:start position:0% +prime is zero +when you write it this way around that + + align:start position:0% +when you write it this way around that + + + align:start position:0% +when you write it this way around that +makes more sense + + align:start position:0% +makes more sense + + + align:start position:0% +makes more sense +okay + + align:start position:0% +okay + + + align:start position:0% +okay +now we don't know theta + + align:start position:0% +now we don't know theta + + + align:start position:0% +now we don't know theta +but + + align:start position:0% +but + + + align:start position:0% +but +we can + + align:start position:0% +we can + + + align:start position:0% +we can +rotate + + align:start position:0% +rotate + + + align:start position:0% +rotate +using some test angles and by an + + align:start position:0% +using some test angles and by an + + + align:start position:0% +using some test angles and by an +iterative method + + align:start position:0% +iterative method + + + align:start position:0% +iterative method +uh you know keep on improving keep on + + align:start position:0% +uh you know keep on improving keep on + + + align:start position:0% +uh you know keep on improving keep on +coming closer to to this situation where + + align:start position:0% +coming closer to to this situation where + + + align:start position:0% +coming closer to to this situation where +the y component of the gradient is + + align:start position:0% +the y component of the gradient is + + + align:start position:0% +the y component of the gradient is +reduced to zero + + align:start position:0% + + + + align:start position:0% + +so the + + align:start position:0% +so the + + + align:start position:0% +so the +superscripts in parenthesis again refer + + align:start position:0% +superscripts in parenthesis again refer + + + align:start position:0% +superscripts in parenthesis again refer +to the iteration number + + align:start position:0% +to the iteration number + + + align:start position:0% +to the iteration number +rather than being powers + + align:start position:0% + + + + align:start position:0% + +and of course we know in 2d a rotation + + align:start position:0% +and of course we know in 2d a rotation + + + align:start position:0% +and of course we know in 2d a rotation +matrix is just very simple + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and so + + align:start position:0% +and so + + + align:start position:0% +and so +one thing we can do is have a sequence + + align:start position:0% +one thing we can do is have a sequence + + + align:start position:0% +one thing we can do is have a sequence +of thetas that we try + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +when when we're finished with this + + align:start position:0% +when when we're finished with this + + + align:start position:0% +when when we're finished with this +iteration when we decide to stop + + align:start position:0% +iteration when we decide to stop + + + align:start position:0% +iteration when we decide to stop +the answer for the angle is just the sum + + align:start position:0% +the answer for the angle is just the sum + + + align:start position:0% +the answer for the angle is just the sum +of all of those + + align:start position:0% +of all of those + + + align:start position:0% +of all of those +increments we make so + + align:start position:0% +increments we make so + + + align:start position:0% +increments we make so +you can imagine various strategies like + + align:start position:0% +you can imagine various strategies like + + + align:start position:0% +you can imagine various strategies like +you can try an angle and suppose that + + align:start position:0% +you can try an angle and suppose that + + + align:start position:0% +you can try an angle and suppose that +this goes the wrong way well then maybe + + align:start position:0% +this goes the wrong way well then maybe + + + align:start position:0% +this goes the wrong way well then maybe +take half that angle + + align:start position:0% +take half that angle + + + align:start position:0% +take half that angle +and try that or + + align:start position:0% +and try that or + + + align:start position:0% +and try that or +you could try turning through that angle + + align:start position:0% +you could try turning through that angle + + + align:start position:0% +you could try turning through that angle +positive and through the angle negative + + align:start position:0% +positive and through the angle negative + + + align:start position:0% +positive and through the angle negative +and compare the two results see which + + align:start position:0% +and compare the two results see which + + + align:start position:0% +and compare the two results see which +one works better and then keep on + + align:start position:0% +one works better and then keep on + + + align:start position:0% +one works better and then keep on +reducing the size of the angle + + align:start position:0% +reducing the size of the angle + + + align:start position:0% +reducing the size of the angle +until you converge until or at least + + align:start position:0% +until you converge until or at least + + + align:start position:0% +until you converge until or at least +until you're you know happy enough with + + align:start position:0% +until you're you know happy enough with + + + align:start position:0% +until you're you know happy enough with +the results so + + align:start position:0% +the results so + + + align:start position:0% +the results so +so each time reduce + + align:start position:0% +so each time reduce + + + align:start position:0% +so each time reduce +each step + + align:start position:0% +each step + + + align:start position:0% +each step +reduce + + align:start position:0% +reduce + + + align:start position:0% +reduce +the magnitude of ey + + align:start position:0% +the magnitude of ey + + + align:start position:0% +the magnitude of ey +and + + align:start position:0% + + + + align:start position:0% + +and it will increase the other one + + align:start position:0% + + + + align:start position:0% + +right because as we rotate closer to + + align:start position:0% +right because as we rotate closer to + + + align:start position:0% +right because as we rotate closer to +the x-axis + + align:start position:0% +the x-axis + + + align:start position:0% +the x-axis +the projection of this onto the x-axis + + align:start position:0% +the projection of this onto the x-axis + + + align:start position:0% +the projection of this onto the x-axis +will will increase + + align:start position:0% +will will increase + + + align:start position:0% +will will increase +okay so that's the the iteration + + align:start position:0% +okay so that's the the iteration + + + align:start position:0% +okay so that's the the iteration +and how do we pick the thetas well we + + align:start position:0% +and how do we pick the thetas well we + + + align:start position:0% +and how do we pick the thetas well we +could do this theta zero is pi over two + + align:start position:0% +could do this theta zero is pi over two + + + align:start position:0% +could do this theta zero is pi over two +theta one is pi over four + + align:start position:0% +theta one is pi over four + + + align:start position:0% +theta one is pi over four +theta two is pi over eight + + align:start position:0% +theta two is pi over eight + + + align:start position:0% +theta two is pi over eight +you know and so on + + align:start position:0% +you know and so on + + + align:start position:0% +you know and so on +that'd be one sort of obvious approach + + align:start position:0% +that'd be one sort of obvious approach + + + align:start position:0% +that'd be one sort of obvious approach +so we try and turn through these + + align:start position:0% +so we try and turn through these + + + align:start position:0% +so we try and turn through these +different angles and see if it + + align:start position:0% +different angles and see if it + + + align:start position:0% +different angles and see if it +and we accept we accept the change if it + + align:start position:0% +and we accept we accept the change if it + + + align:start position:0% +and we accept we accept the change if it +satisfies this condition + + align:start position:0% +satisfies this condition + + + align:start position:0% +satisfies this condition +that + + align:start position:0% +that + + + align:start position:0% +that +magnitude that e y is reduced it doesn't + + align:start position:0% +magnitude that e y is reduced it doesn't + + + align:start position:0% +magnitude that e y is reduced it doesn't +have to be positive so it could + + align:start position:0% +have to be positive so it could + + + align:start position:0% +have to be positive so it could +overcompensate as long as the magnitude + + align:start position:0% +overcompensate as long as the magnitude + + + align:start position:0% +overcompensate as long as the magnitude +is reduced and you can always flip it to + + align:start position:0% +is reduced and you can always flip it to + + + align:start position:0% +is reduced and you can always flip it to +make it positive again if you want to + + align:start position:0% +make it positive again if you want to + + + align:start position:0% +make it positive again if you want to +um so you can do that um but it's + + align:start position:0% +um so you can do that um but it's + + + align:start position:0% +um so you can do that um but it's +expensive for two reasons one is you got + + align:start position:0% +expensive for two reasons one is you got + + + align:start position:0% +expensive for two reasons one is you got +the cosines and the sines + + align:start position:0% +the cosines and the sines + + + align:start position:0% +the cosines and the sines +but you could build a table obviously + + align:start position:0% +but you could build a table obviously + + + align:start position:0% +but you could build a table obviously +you could just store the cosines and + + align:start position:0% +you could just store the cosines and + + + align:start position:0% +you could just store the cosines and +sines of these angles the other one is + + align:start position:0% +sines of these angles the other one is + + + align:start position:0% +sines of these angles the other one is +you need each time you need four + + align:start position:0% +you need each time you need four + + + align:start position:0% +you need each time you need four +multiplications and two additions + + align:start position:0% +multiplications and two additions + + + align:start position:0% +multiplications and two additions +it doesn't sound like much but remember + + align:start position:0% +it doesn't sound like much but remember + + + align:start position:0% +it doesn't sound like much but remember +this happens several times because of + + align:start position:0% +this happens several times because of + + + align:start position:0% +this happens several times because of +the iterations and it happens at every + + align:start position:0% +the iterations and it happens at every + + + align:start position:0% +the iterations and it happens at every +pixel so it's expensive + + align:start position:0% +pixel so it's expensive + + + align:start position:0% +pixel so it's expensive +so how to avoid multiplication + + align:start position:0% +so how to avoid multiplication + + + align:start position:0% +so how to avoid multiplication +well what we can do is + + align:start position:0% +well what we can do is + + + align:start position:0% +well what we can do is +pick the angles very carefully + + align:start position:0% + + + + align:start position:0% + +suppose that we pick the angles + + align:start position:0% + + + + align:start position:0% + +so that there are inverse powers of 2. + + align:start position:0% + + + + align:start position:0% + +then that matrix there + + align:start position:0% + + + + align:start position:0% + +the rotation matrix + + align:start position:0% +the rotation matrix + + + align:start position:0% +the rotation matrix +just becomes this + + align:start position:0% +just becomes this + + + align:start position:0% +just becomes this +and the matrix part of this + + align:start position:0% +and the matrix part of this + + + align:start position:0% +and the matrix part of this +is very easy to compute you know + + align:start position:0% +is very easy to compute you know + + + align:start position:0% +is very easy to compute you know +multiplication by one doesn't cost us + + align:start position:0% +multiplication by one doesn't cost us + + + align:start position:0% +multiplication by one doesn't cost us +anything + + align:start position:0% +anything + + + align:start position:0% +anything +and this is just a shift and shifts are + + align:start position:0% +and this is just a shift and shifts are + + + align:start position:0% +and this is just a shift and shifts are +extremely cheap + + align:start position:0% +extremely cheap + + + align:start position:0% +extremely cheap +and then we have an addition so it + + align:start position:0% +and then we have an addition so it + + + align:start position:0% +and then we have an addition so it +reduces the whole thing down to two + + align:start position:0% +reduces the whole thing down to two + + + align:start position:0% +reduces the whole thing down to two +additions + + align:start position:0% +additions + + + align:start position:0% +additions +from uh four multiplications and two + + align:start position:0% +from uh four multiplications and two + + + align:start position:0% +from uh four multiplications and two +additions + + align:start position:0% +additions + + + align:start position:0% +additions +okay + + align:start position:0% +okay + + + align:start position:0% +okay +uh well then we have and we do this + + align:start position:0% +uh well then we have and we do this + + + align:start position:0% +uh well then we have and we do this +repeatedly + + align:start position:0% + + + + align:start position:0% + +as + + align:start position:0% +as + + + align:start position:0% +as +and you can see that the angle we're + + align:start position:0% +and you can see that the angle we're + + + align:start position:0% +and you can see that the angle we're +turning through gets smaller and smaller + + align:start position:0% +turning through gets smaller and smaller + + + align:start position:0% +turning through gets smaller and smaller +what what is that angle + + align:start position:0% +what what is that angle + + + align:start position:0% +what what is that angle +let's see + + align:start position:0% + + + + align:start position:0% + +we can compute it from that formula + + align:start position:0% +we can compute it from that formula + + + align:start position:0% +we can compute it from that formula +after a while it basically uh + + align:start position:0% +after a while it basically uh + + + align:start position:0% +after a while it basically uh +gets + + align:start position:0% +gets + + + align:start position:0% +gets +halved + + align:start position:0% +halved + + + align:start position:0% +halved +initially because of the non-linear + + align:start position:0% +initially because of the non-linear + + + align:start position:0% +initially because of the non-linear +nature of trigonometric functions it's + + align:start position:0% +nature of trigonometric functions it's + + + align:start position:0% +nature of trigonometric functions it's +not half but eventually it becomes r and + + align:start position:0% +not half but eventually it becomes r and + + + align:start position:0% +not half but eventually it becomes r and +then uh when you're done you you end up + + align:start position:0% +then uh when you're done you you end up + + + align:start position:0% +then uh when you're done you you end up +over here you end up with a product of + + align:start position:0% +over here you end up with a product of + + + align:start position:0% +over here you end up with a product of +all of these cosine theta i's + + align:start position:0% +all of these cosine theta i's + + + align:start position:0% +all of these cosine theta i's +and so what do you do with that well + + align:start position:0% + + + + align:start position:0% + +maybe you don't care because it's just a + + align:start position:0% +maybe you don't care because it's just a + + + align:start position:0% +maybe you don't care because it's just a +constant multiplier + + align:start position:0% +constant multiplier + + + align:start position:0% +constant multiplier +but suppose you do care + + align:start position:0% + + + + align:start position:0% + +then + + align:start position:0% + + + + align:start position:0% + +you can pre-compute it + + align:start position:0% +you can pre-compute it + + + align:start position:0% +you can pre-compute it +and actually + + align:start position:0% +and actually + + + align:start position:0% +and actually +it's + + align:start position:0% +it's + + + align:start position:0% +it's +1.16 very quickly it converges very fast + + align:start position:0% +1.16 very quickly it converges very fast + + + align:start position:0% +1.16 very quickly it converges very fast +so you can just use 1.16 + + align:start position:0% +so you can just use 1.16 + + + align:start position:0% +so you can just use 1.16 +okay so that's the basic idea of chordic + + align:start position:0% +okay so that's the basic idea of chordic + + + align:start position:0% +okay so that's the basic idea of chordic +that we rotate but through special + + align:start position:0% +that we rotate but through special + + + align:start position:0% +that we rotate but through special +angles + + align:start position:0% +angles + + + align:start position:0% +angles +that have this property that were the + + align:start position:0% +that have this property that were the + + + align:start position:0% +that have this property that were the +you know the tangent of theta i is one + + align:start position:0% +you know the tangent of theta i is one + + + align:start position:0% +you know the tangent of theta i is one +over uh two to the i + + align:start position:0% +over uh two to the i + + + align:start position:0% +over uh two to the i +um and + + align:start position:0% +um and + + + align:start position:0% +um and +um + + align:start position:0% +um + + + align:start position:0% +um +well + + align:start position:0% +well + + + align:start position:0% +well +it takes a bit longer to explain it in + + align:start position:0% +it takes a bit longer to explain it in + + + align:start position:0% +it takes a bit longer to explain it in +the paper but that's the basic idea and + + align:start position:0% +the paper but that's the basic idea and + + + align:start position:0% +the paper but that's the basic idea and +so uh the iterative process is + + align:start position:0% +so uh the iterative process is + + + align:start position:0% +so uh the iterative process is +you um you change through that angle and + + align:start position:0% +you um you change through that angle and + + + align:start position:0% +you um you change through that angle and +if it improves the answer you keep it + + align:start position:0% +if it improves the answer you keep it + + + align:start position:0% +if it improves the answer you keep it +and then you keep track of whether it + + align:start position:0% +and then you keep track of whether it + + + align:start position:0% +and then you keep track of whether it +got negative or not and the first thing + + align:start position:0% +got negative or not and the first thing + + + align:start position:0% +got negative or not and the first thing +you have to do is get it to the + + align:start position:0% +you have to do is get it to the + + + align:start position:0% +you have to do is get it to the +first octant you know the whole idea + + align:start position:0% +first octant you know the whole idea + + + align:start position:0% +first octant you know the whole idea +here is that you're working in this + + align:start position:0% +here is that you're working in this + + + align:start position:0% +here is that you're working in this +regime + + align:start position:0% +regime + + + align:start position:0% +regime +but that's obviously trivial you just + + align:start position:0% +but that's obviously trivial you just + + + align:start position:0% +but that's obviously trivial you just +look at the signs of x and y + + align:start position:0% +look at the signs of x and y + + + align:start position:0% +look at the signs of x and y +and whether + + align:start position:0% +and whether + + + align:start position:0% +and whether +y is greater than x and you can reduce + + align:start position:0% +y is greater than x and you can reduce + + + align:start position:0% +y is greater than x and you can reduce +it to the first auction + + align:start position:0% +it to the first auction + + + align:start position:0% +it to the first auction +okay so next time we'll talk about + + align:start position:0% +okay so next time we'll talk about + + + align:start position:0% +okay so next time we'll talk about +multi-scale + + align:start position:0% +multi-scale + + + align:start position:0% +multi-scale +and + + align:start position:0% +and + + + align:start position:0% +and +we'll talk a little bit about + + align:start position:0% +we'll talk a little bit about + + + align:start position:0% +we'll talk a little bit about +sampling and aliasing because + + align:start position:0% +sampling and aliasing because + + + align:start position:0% +sampling and aliasing because +because that's part of the multi-scale + + align:start position:0% +because that's part of the multi-scale + + + align:start position:0% +because that's part of the multi-scale +story so again please start early on the + + align:start position:0% +story so again please start early on the + + + align:start position:0% +story so again please start early on the +quiz it's more work than the typical + + align:start position:0% +quiz it's more work than the typical + + + align:start position:0% +quiz it's more work than the typical +homework problem \ No newline at end of file diff --git a/jg7XtfWa_Yg.txt b/jg7XtfWa_Yg.txt new file mode 100644 index 0000000000000000000000000000000000000000..1a8ecd11864903ee1de1639fa0a67443a953dbae --- /dev/null +++ b/jg7XtfWa_Yg.txt @@ -0,0 +1,9323 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT OpenCourseWare continue to + + align:start position:0% +will help MIT OpenCourseWare continue to + + + align:start position:0% +will help MIT OpenCourseWare continue to +offer high quality educational resources + + align:start position:0% +offer high quality educational resources + + + align:start position:0% +offer high quality educational resources +for free + + align:start position:0% +for free + + + align:start position:0% +for free +to make a donation or view additional + + align:start position:0% +to make a donation or view additional + + + align:start position:0% +to make a donation or view additional +materials from hundreds of MIT courses + + align:start position:0% +materials from hundreds of MIT courses + + + align:start position:0% +materials from hundreds of MIT courses +visit MIT opencourseware at ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +this is a second recitation on + + align:start position:0% +this is a second recitation on + + + align:start position:0% +this is a second recitation on +cholesterol and it's really sort of + + align:start position:0% +cholesterol and it's really sort of + + + align:start position:0% +cholesterol and it's really sort of +focused on this question of how do you + + align:start position:0% +focused on this question of how do you + + + align:start position:0% +focused on this question of how do you +sense cholesterol in a membrane okay so + + align:start position:0% +sense cholesterol in a membrane okay so + + + align:start position:0% +sense cholesterol in a membrane okay so +that's really sort of a tough problem + + align:start position:0% +that's really sort of a tough problem + + + align:start position:0% +that's really sort of a tough problem +and they've developed new tools and + + align:start position:0% +and they've developed new tools and + + + align:start position:0% +and they've developed new tools and +that's what we're gonna be talking about + + align:start position:0% +that's what we're gonna be talking about + + + align:start position:0% +that's what we're gonna be talking about +what the tools are and whether you would + + align:start position:0% +what the tools are and whether you would + + + align:start position:0% +what the tools are and whether you would +think they were adequate to be able to + + align:start position:0% +think they were adequate to be able to + + + align:start position:0% +think they were adequate to be able to +address this question about what kinds + + align:start position:0% +address this question about what kinds + + + align:start position:0% +address this question about what kinds +of changes in concentration of + + align:start position:0% +of changes in concentration of + + + align:start position:0% +of changes in concentration of +cholesterol number one can you measure + + align:start position:0% +cholesterol number one can you measure + + + align:start position:0% +cholesterol number one can you measure +them and number two what effects do they + + align:start position:0% +them and number two what effects do they + + + align:start position:0% +them and number two what effects do they +have in terms of whether you're gonna + + align:start position:0% +have in terms of whether you're gonna + + + align:start position:0% +have in terms of whether you're gonna +turn on cholesterol biosynthesis and + + align:start position:0% +turn on cholesterol biosynthesis and + + + align:start position:0% +turn on cholesterol biosynthesis and +uptake because you need more cholesterol + + align:start position:0% +uptake because you need more cholesterol + + + align:start position:0% +uptake because you need more cholesterol +or you're gonna turn the whole thing + + align:start position:0% +or you're gonna turn the whole thing + + + align:start position:0% +or you're gonna turn the whole thing +okay so we've been focusing as we + + align:start position:0% +okay so we've been focusing as we + + + align:start position:0% +okay so we've been focusing as we +described in the last few lectures in + + align:start position:0% +described in the last few lectures in + + + align:start position:0% +described in the last few lectures in +the endoplasmic reticulum and what would + + align:start position:0% +the endoplasmic reticulum and what would + + + align:start position:0% +the endoplasmic reticulum and what would +the cholesterol chain tweeted the + + align:start position:0% +the cholesterol chain tweeted the + + + align:start position:0% +the cholesterol chain tweeted the +Colossus what kinds of changes in + + align:start position:0% +Colossus what kinds of changes in + + + align:start position:0% +Colossus what kinds of changes in +cholesterol + + align:start position:0% +cholesterol + + + align:start position:0% +cholesterol +did they see in the experiments they + + align:start position:0% +did they see in the experiments they + + + align:start position:0% +did they see in the experiments they +were doing in this paper what would the + + align:start position:0% +were doing in this paper what would the + + + align:start position:0% +were doing in this paper what would the +range of changes that they saw yeah so I + + align:start position:0% +range of changes that they saw yeah so I + + + align:start position:0% +range of changes that they saw yeah so I +don't see so so something low say they + + align:start position:0% +don't see so so something low say they + + + align:start position:0% +don't see so so something low say they +were trying to do this same experiment + + align:start position:0% +were trying to do this same experiment + + + align:start position:0% +were trying to do this same experiment +in the plasma membrane how do we know + + align:start position:0% +in the plasma membrane how do we know + + + align:start position:0% +in the plasma membrane how do we know +it's the ER membrane that does this + + align:start position:0% +it's the ER membrane that does this + + + align:start position:0% +it's the ER membrane that does this +sensing that's what the whole paper is + + align:start position:0% +sensing that's what the whole paper is + + + align:start position:0% +sensing that's what the whole paper is +focused on that's what everything we + + align:start position:0% +focused on that's what everything we + + + align:start position:0% +focused on that's what everything we +focused on in class say you wanted to do + + align:start position:0% +focused on in class say you wanted to do + + + align:start position:0% +focused on in class say you wanted to do +a similar kind of experiment in the + + align:start position:0% +a similar kind of experiment in the + + + align:start position:0% +a similar kind of experiment in the +plasma membrane do you remember what I + + align:start position:0% +plasma membrane do you remember what I + + + align:start position:0% +plasma membrane do you remember what I +said about the levels of cholesterol so + + align:start position:0% +said about the levels of cholesterol so + + + align:start position:0% +said about the levels of cholesterol so +they distributed throughout the cell + + align:start position:0% +they distributed throughout the cell + + + align:start position:0% +they distributed throughout the cell +right in all membranes where is the most + + align:start position:0% +right in all membranes where is the most + + + align:start position:0% +right in all membranes where is the most +cholesterol okay so if you don't + + align:start position:0% +cholesterol okay so if you don't + + + align:start position:0% +cholesterol okay so if you don't +remember it's the plasma membrane okay + + align:start position:0% +remember it's the plasma membrane okay + + + align:start position:0% +remember it's the plasma membrane okay +so say instead of having seven or eight + + align:start position:0% +so say instead of having seven or eight + + + align:start position:0% +so say instead of having seven or eight +percent of the lipids cholesterol say + + align:start position:0% +percent of the lipids cholesterol say + + + align:start position:0% +percent of the lipids cholesterol say +you had forty percent that's an + + align:start position:0% +you had forty percent that's an + + + align:start position:0% +you had forty percent that's an +over-exaggeration do you think this kind + + align:start position:0% +over-exaggeration do you think this kind + + + align:start position:0% +over-exaggeration do you think this kind +of an experiment would be hard to do + + align:start position:0% +of an experiment would be hard to do + + + align:start position:0% +of an experiment would be hard to do +that they've talked about in this paper + + align:start position:0% +that they've talked about in this paper + + + align:start position:0% +that they've talked about in this paper +so you would want to do this if you + + align:start position:0% +so you would want to do this if you + + + align:start position:0% +so you would want to do this if you +tried to do the same experiment with the + + align:start position:0% +tried to do the same experiment with the + + + align:start position:0% +tried to do the same experiment with the +plasma membrane + + align:start position:0% + + + + align:start position:0% + +so the key issue that you need to think + + align:start position:0% +so the key issue that you need to think + + + align:start position:0% +so the key issue that you need to think +about is go back and look at the changes + + align:start position:0% +about is go back and look at the changes + + + align:start position:0% +about is go back and look at the changes +you know they they did a whole bunch of + + align:start position:0% +you know they they did a whole bunch of + + + align:start position:0% +you know they they did a whole bunch of +different experiments say sort of I mean + + align:start position:0% +different experiments say sort of I mean + + + align:start position:0% +different experiments say sort of I mean +the numbers of score she but they came + + align:start position:0% +the numbers of score she but they came + + + align:start position:0% +the numbers of score she but they came +up with numbers that sort of reproduce + + align:start position:0% +up with numbers that sort of reproduce + + + align:start position:0% +up with numbers that sort of reproduce +themselves I thought in a sort of an + + align:start position:0% +themselves I thought in a sort of an + + + align:start position:0% +themselves I thought in a sort of an +amazing way but now say you wanted to do + + align:start position:0% +amazing way but now say you wanted to do + + + align:start position:0% +amazing way but now say you wanted to do +this in in the plasma membrane where the + + align:start position:0% +this in in the plasma membrane where the + + + align:start position:0% +this in in the plasma membrane where the +levels of cholesterol are much higher do + + align:start position:0% +levels of cholesterol are much higher do + + + align:start position:0% +levels of cholesterol are much higher do +you think it would be easy to do using + + align:start position:0% +you think it would be easy to do using + + + align:start position:0% +you think it would be easy to do using +the same techniques that are described + + align:start position:0% +the same techniques that are described + + + align:start position:0% +the same techniques that are described +that we're gonna discuss or not and what + + align:start position:0% +that we're gonna discuss or not and what + + + align:start position:0% +that we're gonna discuss or not and what +would the issues be yeah so I don't know + + align:start position:0% +would the issues be yeah so I don't know + + + align:start position:0% +would the issues be yeah so I don't know +so that's an interesting question so + + align:start position:0% +so that's an interesting question so + + + align:start position:0% +so that's an interesting question so +you'd have to deplete so that's gonna be + + align:start position:0% +you'd have to deplete so that's gonna be + + + align:start position:0% +you'd have to deplete so that's gonna be +it we're gonna have to control the less + + align:start position:0% +it we're gonna have to control the less + + + align:start position:0% +it we're gonna have to control the less +cholesterol levels but what change in if + + align:start position:0% +cholesterol levels but what change in if + + + align:start position:0% +cholesterol levels but what change in if +you looked at the changes in levels of + + align:start position:0% +you looked at the changes in levels of + + + align:start position:0% +you looked at the changes in levels of +cholesterol in the ER how much did they + + align:start position:0% +cholesterol in the ER how much did they + + + align:start position:0% +cholesterol in the ER how much did they +change they changed from what to what + + align:start position:0% +change they changed from what to what + + + align:start position:0% +change they changed from what to what +from 2% to 7% okay say that you were + + align:start position:0% +from 2% to 7% okay say that you were + + + align:start position:0% +from 2% to 7% okay say that you were +sort of in that same range of change + + align:start position:0% +sort of in that same range of change + + + align:start position:0% +sort of in that same range of change +that was going to turn on a switch in in + + align:start position:0% +that was going to turn on a switch in in + + + align:start position:0% +that was going to turn on a switch in in +the plasma membrane and say you could + + align:start position:0% +the plasma membrane and say you could + + + align:start position:0% +the plasma membrane and say you could +control the levels do you think it would + + align:start position:0% +control the levels do you think it would + + + align:start position:0% +control the levels do you think it would +be easy to see that so you start with + + align:start position:0% +be easy to see that so you start with + + + align:start position:0% +be easy to see that so you start with +40% say that's sort of the norm say the + + align:start position:0% +40% say that's sort of the norm say the + + + align:start position:0% +40% say that's sort of the norm say the +change was very similar to what you see + + align:start position:0% +change was very similar to what you see + + + align:start position:0% +change was very similar to what you see +in the change in the ER do you think + + align:start position:0% +in the change in the ER do you think + + + align:start position:0% +in the change in the ER do you think +that would be easy to detect no because + + align:start position:0% +that would be easy to detect no because + + + align:start position:0% +that would be easy to detect no because +now you have two big numbers and there's + + align:start position:0% +now you have two big numbers and there's + + + align:start position:0% +now you have two big numbers and there's +a huge amount of error in this method of + + align:start position:0% +a huge amount of error in this method of + + + align:start position:0% +a huge amount of error in this method of +analysis so those are the kinds of + + align:start position:0% +analysis so those are the kinds of + + + align:start position:0% +analysis so those are the kinds of +things I'm trying to get you to think + + align:start position:0% +things I'm trying to get you to think + + + align:start position:0% +things I'm trying to get you to think +about I don't know why it's the ER I + + align:start position:0% +about I don't know why it's the ER I + + + align:start position:0% +about I don't know why it's the ER I +mean everybody's focused on the ER okay + + align:start position:0% +mean everybody's focused on the ER okay + + + align:start position:0% +mean everybody's focused on the ER okay +good cholesterol and other organelles I + + align:start position:0% +good cholesterol and other organelles I + + + align:start position:0% +good cholesterol and other organelles I +have a different regulatory mechanism or + + align:start position:0% +have a different regulatory mechanism or + + + align:start position:0% +have a different regulatory mechanism or +somehow be connected still to what's + + align:start position:0% +somehow be connected still to what's + + + align:start position:0% +somehow be connected still to what's +going on in the air it could be + + align:start position:0% +going on in the air it could be + + + align:start position:0% +going on in the air it could be +I mean we have the simplest you started + + align:start position:0% +I mean we have the simplest you started + + + align:start position:0% +I mean we have the simplest you started +out with the simplest model you can get + + align:start position:0% +out with the simplest model you can get + + + align:start position:0% +out with the simplest model you can get +and you test it but then as you learn + + align:start position:0% +and you test it but then as you learn + + + align:start position:0% +and you test it but then as you learn +more people you know we have more and + + align:start position:0% +more people you know we have more and + + + align:start position:0% +more people you know we have more and +more technology we learn new things you + + align:start position:0% +more technology we learn new things you + + + align:start position:0% +more technology we learn new things you +go back and you revisit and rethink + + align:start position:0% +go back and you revisit and rethink + + + align:start position:0% +go back and you revisit and rethink +about what's going on so the key + + align:start position:0% +about what's going on so the key + + + align:start position:0% +about what's going on so the key +question is it's really sort of this + + align:start position:0% +question is it's really sort of this + + + align:start position:0% +question is it's really sort of this +switch having cholesterol that keeps it + + align:start position:0% +switch having cholesterol that keeps it + + + align:start position:0% +switch having cholesterol that keeps it +in the membrane or not having + + align:start position:0% +in the membrane or not having + + + align:start position:0% +in the membrane or not having +cholesterol and the question is what are + + align:start position:0% +cholesterol and the question is what are + + + align:start position:0% +cholesterol and the question is what are +the differences in the levels that allow + + align:start position:0% +the differences in the levels that allow + + + align:start position:0% +the differences in the levels that allow +turn on of cholesterol biosynthesis and + + align:start position:0% +turn on of cholesterol biosynthesis and + + + align:start position:0% +turn on of cholesterol biosynthesis and +LDL + + align:start position:0% +LDL + + + align:start position:0% +LDL +biosynthesis which then allows uptake of + + align:start position:0% +biosynthesis which then allows uptake of + + + align:start position:0% +biosynthesis which then allows uptake of +cholesterol from the diet okay so that's + + align:start position:0% +cholesterol from the diet okay so that's + + + align:start position:0% +cholesterol from the diet okay so that's +the question and what does this look + + align:start position:0% +the question and what does this look + + + align:start position:0% +the question and what does this look +like if people hadn't measured this by + + align:start position:0% +like if people hadn't measured this by + + + align:start position:0% +like if people hadn't measured this by +any method and I'm this model I've gone + + align:start position:0% +any method and I'm this model I've gone + + + align:start position:0% +any method and I'm this model I've gone +through a number of times in class today + + align:start position:0% +through a number of times in class today + + + align:start position:0% +through a number of times in class today +so I'm not gonna go through it again + + align:start position:0% +so I'm not gonna go through it again + + + align:start position:0% +so I'm not gonna go through it again +hopefully you all know that and some + + align:start position:0% +hopefully you all know that and some + + + align:start position:0% +hopefully you all know that and some +forming a head or you have the picture + + align:start position:0% +forming a head or you have the picture + + + align:start position:0% +forming a head or you have the picture +in front of you so you can remember it + + align:start position:0% +in front of you so you can remember it + + + align:start position:0% +in front of you so you can remember it +so these are the questions I want to + + align:start position:0% +so these are the questions I want to + + + align:start position:0% +so these are the questions I want to +pose and I want you guys to do the + + align:start position:0% +pose and I want you guys to do the + + + align:start position:0% +pose and I want you guys to do the +talking today okay and what I'm gonna do + + align:start position:0% +talking today okay and what I'm gonna do + + + align:start position:0% +talking today okay and what I'm gonna do +is I have most of the figures on on my + + align:start position:0% +is I have most of the figures on on my + + + align:start position:0% +is I have most of the figures on on my +PowerPoint so we can bring them up and + + align:start position:0% +PowerPoint so we can bring them up and + + + align:start position:0% +PowerPoint so we can bring them up and +look at them and you can tell me what + + align:start position:0% +look at them and you can tell me what + + + align:start position:0% +look at them and you can tell me what +you see + + align:start position:0% +you see + + + align:start position:0% +you see +and then other every everybody might be + + align:start position:0% +and then other every everybody might be + + + align:start position:0% +and then other every everybody might be +seeing something different + + align:start position:0% +seeing something different + + + align:start position:0% +seeing something different +and so we're thinking about this + + align:start position:0% +and so we're thinking about this + + + align:start position:0% +and so we're thinking about this +differently and maybe we come to some + + align:start position:0% +differently and maybe we come to some + + + align:start position:0% +differently and maybe we come to some +kind of consensus about whether these + + align:start position:0% +kind of consensus about whether these + + + align:start position:0% +kind of consensus about whether these +experiments were carried out well or not + + align:start position:0% +experiments were carried out well or not + + + align:start position:0% +experiments were carried out well or not +so so one of the first things so these + + align:start position:0% +so so one of the first things so these + + + align:start position:0% +so so one of the first things so these +are the sort of be the general things + + align:start position:0% +are the sort of be the general things + + + align:start position:0% +are the sort of be the general things +and then we'll step through them but + + align:start position:0% +and then we'll step through them but + + + align:start position:0% +and then we'll step through them but +they wanted to perturb the cellular + + align:start position:0% +they wanted to perturb the cellular + + + align:start position:0% +they wanted to perturb the cellular +cholesterol levels and how did they end + + align:start position:0% +cholesterol levels and how did they end + + + align:start position:0% +cholesterol levels and how did they end +up doing that did that did that make + + align:start position:0% +up doing that did that did that make + + + align:start position:0% +up doing that did that did that make +sense we talked a little bit about this + + align:start position:0% +sense we talked a little bit about this + + + align:start position:0% +sense we talked a little bit about this +already I mean what did they use as + + align:start position:0% +already I mean what did they use as + + + align:start position:0% +already I mean what did they use as +tools to do that + + align:start position:0% + + + + align:start position:0% + +so you need to speak louder because I + + align:start position:0% +so you need to speak louder because I + + + align:start position:0% +so you need to speak louder because I +really am deaf sorry so that's one place + + align:start position:0% +really am deaf sorry so that's one place + + + align:start position:0% +really am deaf sorry so that's one place +so they can deplete cholesterol for the + + align:start position:0% +so they can deplete cholesterol for the + + + align:start position:0% +so they can deplete cholesterol for the +media but then where do they do so the + + align:start position:0% +media but then where do they do so the + + + align:start position:0% +media but then where do they do so the +whole paper is sort of about this how + + align:start position:0% +whole paper is sort of about this how + + + align:start position:0% +whole paper is sort of about this how +did they control the so weights let's + + align:start position:0% +did they control the so weights let's + + + align:start position:0% +did they control the so weights let's +assume that they can do that and that's + + align:start position:0% +assume that they can do that and that's + + + align:start position:0% +assume that they can do that and that's +you know they got good at that I think a + + align:start position:0% +you know they got good at that I think a + + + align:start position:0% +you know they got good at that I think a +lot of people have used that method and + + align:start position:0% +lot of people have used that method and + + + align:start position:0% +lot of people have used that method and +so they can deplete media so why do they + + align:start position:0% +so they can deplete media so why do they + + + align:start position:0% +so they can deplete media so why do they +hide it how did they deplete cholesterol + + align:start position:0% +hide it how did they deplete cholesterol + + + align:start position:0% +hide it how did they deplete cholesterol +there were some unusual ways to deplete + + align:start position:0% +there were some unusual ways to deplete + + + align:start position:0% +there were some unusual ways to deplete +cholesterol in this paper did any of you + + align:start position:0% +cholesterol in this paper did any of you + + + align:start position:0% +cholesterol in this paper did any of you +pick up on that great + + align:start position:0% +pick up on that great + + + align:start position:0% +pick up on that great +so just what did you think that was + + align:start position:0% +so just what did you think that was + + + align:start position:0% +so just what did you think that was +unusual did any of you look up what that + + align:start position:0% +unusual did any of you look up what that + + + align:start position:0% +unusual did any of you look up what that +was yeah so but but what was interesting + + align:start position:0% +was yeah so but but what was interesting + + + align:start position:0% +was yeah so but but what was interesting +about it it was you know hydroxypropyl + + align:start position:0% +about it it was you know hydroxypropyl + + + align:start position:0% +about it it was you know hydroxypropyl +remember HP cyclodextrin okay we're + + align:start position:0% +remember HP cyclodextrin okay we're + + + align:start position:0% +remember HP cyclodextrin okay we're +gonna we're gonna look at this a minute + + align:start position:0% +gonna we're gonna look at this a minute + + + align:start position:0% +gonna we're gonna look at this a minute +but what do we know what was the other + + align:start position:0% +but what do we know what was the other + + + align:start position:0% +but what do we know what was the other +molecule they used to add cholesterol + + align:start position:0% +molecule they used to add cholesterol + + + align:start position:0% +molecule they used to add cholesterol +back right so methyl it's like low + + align:start position:0% +back right so methyl it's like low + + + align:start position:0% +back right so methyl it's like low +dexter i'm going to show you the + + align:start position:0% +dexter i'm going to show you the + + + align:start position:0% +dexter i'm going to show you the +structure but they aren't very different + + align:start position:0% +structure but they aren't very different + + + align:start position:0% +structure but they aren't very different +so I mean did any of any of you ever + + align:start position:0% +so I mean did any of any of you ever + + + align:start position:0% +so I mean did any of any of you ever +heard of cyclodextrins Igor + + align:start position:0% +heard of cyclodextrins Igor + + + align:start position:0% +heard of cyclodextrins Igor +I mean people won the Nobel Prize for + + align:start position:0% +I mean people won the Nobel Prize for + + + align:start position:0% +I mean people won the Nobel Prize for +that don't want it Breslow spent his + + align:start position:0% +that don't want it Breslow spent his + + + align:start position:0% +that don't want it Breslow spent his +whole life studying host-guest + + align:start position:0% +whole life studying host-guest + + + align:start position:0% +whole life studying host-guest +interactions so I mean you guys I don't + + align:start position:0% +interactions so I mean you guys I don't + + + align:start position:0% +interactions so I mean you guys I don't +know what you they teach you it now + + align:start position:0% +know what you they teach you it now + + + align:start position:0% +know what you they teach you it now +anymore but I mean they that used to be + + align:start position:0% +anymore but I mean they that used to be + + + align:start position:0% +anymore but I mean they that used to be +something that was taught a lot + + align:start position:0% +something that was taught a lot + + + align:start position:0% +something that was taught a lot +host-guest interactions trying to + + align:start position:0% +host-guest interactions trying to + + + align:start position:0% +host-guest interactions trying to +understand weak non covalent + + align:start position:0% +understand weak non covalent + + + align:start position:0% +understand weak non covalent +interactions is the basis for + + align:start position:0% +interactions is the basis for + + + align:start position:0% +interactions is the basis for +understanding catalysis but to me that + + align:start position:0% +understanding catalysis but to me that + + + align:start position:0% +understanding catalysis but to me that +was one immediately when I saw this and + + align:start position:0% +was one immediately when I saw this and + + + align:start position:0% +was one immediately when I saw this and +what the heck's going on so then I + + align:start position:0% +what the heck's going on so then I + + + align:start position:0% +what the heck's going on so then I +googled it and you know immediately you + + align:start position:0% +googled it and you know immediately you + + + align:start position:0% +googled it and you know immediately you +know I don't know anything about + + align:start position:0% +know I don't know anything about + + + align:start position:0% +know I don't know anything about +hydroxypropyl you'll google it you look + + align:start position:0% +hydroxypropyl you'll google it you look + + + align:start position:0% +hydroxypropyl you'll google it you look +it up and then you look at it and you + + align:start position:0% +it up and then you look at it and you + + + align:start position:0% +it up and then you look at it and you +know if you were a chemist and you were + + align:start position:0% +know if you were a chemist and you were + + + align:start position:0% +know if you were a chemist and you were +really really interested in the molecule + + align:start position:0% +really really interested in the molecule + + + align:start position:0% +really really interested in the molecule +interactions you might make a model of + + align:start position:0% +interactions you might make a model of + + + align:start position:0% +interactions you might make a model of +it and then see if you could you know + + align:start position:0% +it and then see if you could you know + + + align:start position:0% +it and then see if you could you know +what is the difference between that one + + align:start position:0% +what is the difference between that one + + + align:start position:0% +what is the difference between that one +little group when you look at the + + align:start position:0% +little group when you look at the + + + align:start position:0% +little group when you look at the +structure it's sort of amazing and + + align:start position:0% +structure it's sort of amazing and + + + align:start position:0% +structure it's sort of amazing and +that's like the basis + + align:start position:0% +that's like the basis + + + align:start position:0% +that's like the basis +of most of the experiments so you need + + align:start position:0% +of most of the experiments so you need + + + align:start position:0% +of most of the experiments so you need +to believe that they figured that out + + align:start position:0% +to believe that they figured that out + + + align:start position:0% +to believe that they figured that out +okay and that's not in this paper so if + + align:start position:0% +okay and that's not in this paper so if + + + align:start position:0% +okay and that's not in this paper so if +you really cared about it you would have + + align:start position:0% +you really cared about it you would have + + + align:start position:0% +you really cared about it you would have +to go back and read orally or papers and + + align:start position:0% +to go back and read orally or papers and + + + align:start position:0% +to go back and read orally or papers and +see what are the experiments that led + + align:start position:0% +see what are the experiments that led + + + align:start position:0% +see what are the experiments that led +them to focus on these molecules how + + align:start position:0% +them to focus on these molecules how + + + align:start position:0% +them to focus on these molecules how +else did they end up getting cholesterol + + align:start position:0% +else did they end up getting cholesterol + + + align:start position:0% +else did they end up getting cholesterol +levels back into the cell do you + + align:start position:0% +levels back into the cell do you + + + align:start position:0% +levels back into the cell do you +remember what the other method was so + + align:start position:0% +remember what the other method was so + + + align:start position:0% +remember what the other method was so +we'll come back and we'll talk about + + align:start position:0% +we'll come back and we'll talk about + + + align:start position:0% +we'll come back and we'll talk about +this in a minute so that was one of the + + align:start position:0% +this in a minute so that was one of the + + + align:start position:0% +this in a minute so that was one of the +methods okay so they did add two kind of + + align:start position:0% +methods okay so they did add two kind of + + + align:start position:0% +methods okay so they did add two kind of +sterols and they trying to figure out + + align:start position:0% +sterols and they trying to figure out + + + align:start position:0% +sterols and they trying to figure out +this is sort of another unknown what was + + align:start position:0% +this is sort of another unknown what was + + + align:start position:0% +this is sort of another unknown what was +the difference between the sterols + + align:start position:0% +the difference between the sterols + + + align:start position:0% +the difference between the sterols +simply a hydroxyl group okay say you had + + align:start position:0% +simply a hydroxyl group okay say you had + + + align:start position:0% +simply a hydroxyl group okay say you had +if you looked at this cholesterol was + + align:start position:0% +if you looked at this cholesterol was + + + align:start position:0% +if you looked at this cholesterol was +this guy okay and then they had + + align:start position:0% +this guy okay and then they had + + + align:start position:0% +this guy okay and then they had +something like this guy twenty five I + + align:start position:0% +something like this guy twenty five I + + + align:start position:0% +something like this guy twenty five I +don't remember where is this on the side + + align:start position:0% +don't remember where is this on the side + + + align:start position:0% +don't remember where is this on the side +chains hanging out of the little cheer + + align:start position:0% +chains hanging out of the little cheer + + + align:start position:0% +chains hanging out of the little cheer +this system you have I don't think they + + align:start position:0% +this system you have I don't think they + + + align:start position:0% +this system you have I don't think they +learned very much from that and in fact + + align:start position:0% +learned very much from that and in fact + + + align:start position:0% +learned very much from that and in fact +on your problem set you had all of these + + align:start position:0% +on your problem set you had all of these + + + align:start position:0% +on your problem set you had all of these +different cholesterol analogues I mean I + + align:start position:0% +different cholesterol analogues I mean I + + + align:start position:0% +different cholesterol analogues I mean I +think we still really don't get it I + + align:start position:0% +think we still really don't get it I + + + align:start position:0% +think we still really don't get it I +mean that's complicated we talked about + + align:start position:0% +mean that's complicated we talked about + + + align:start position:0% +mean that's complicated we talked about +this in class you have these + + align:start position:0% +this in class you have these + + + align:start position:0% +this in class you have these +transmembrane helix ease what is it + + align:start position:0% +transmembrane helix ease what is it + + + align:start position:0% +transmembrane helix ease what is it +that's actually the signaling agent so + + align:start position:0% +that's actually the signaling agent so + + + align:start position:0% +that's actually the signaling agent so +people are still asking that questions + + align:start position:0% +people are still asking that questions + + + align:start position:0% +people are still asking that questions +and and we haven't quite gotten that far + + align:start position:0% +and and we haven't quite gotten that far + + + align:start position:0% +and and we haven't quite gotten that far +but if you you've read the reading for + + align:start position:0% +but if you you've read the reading for + + + align:start position:0% +but if you you've read the reading for +HMG co-reductase degradation which is + + align:start position:0% +HMG co-reductase degradation which is + + + align:start position:0% +HMG co-reductase degradation which is +what we're going to be talking about in + + align:start position:0% +what we're going to be talking about in + + + align:start position:0% +what we're going to be talking about in +class the signal or is not the steroid + + align:start position:0% +class the signal or is not the steroid + + + align:start position:0% +class the signal or is not the steroid +the sterile it's someone Ostroff okay + + align:start position:0% +the sterile it's someone Ostroff okay + + + align:start position:0% +the sterile it's someone Ostroff okay +now we have you seen one nostril the + + align:start position:0% +now we have you seen one nostril the + + + align:start position:0% +now we have you seen one nostril the +biosynthetic pathway sort of has one + + align:start position:0% +biosynthetic pathway sort of has one + + + align:start position:0% +biosynthetic pathway sort of has one +Oster all sitting in the middle it's not + + align:start position:0% +Oster all sitting in the middle it's not + + + align:start position:0% +Oster all sitting in the middle it's not +all that different structurally from + + align:start position:0% +all that different structurally from + + + align:start position:0% +all that different structurally from +cholesterol you need to go back in it's + + align:start position:0% +cholesterol you need to go back in it's + + + align:start position:0% +cholesterol you need to go back in it's +got fork they all have they both have + + align:start position:0% +got fork they all have they both have + + + align:start position:0% +got fork they all have they both have +four membered rings they have different + + align:start position:0% +four membered rings they have different + + + align:start position:0% +four membered rings they have different +extra methyl groups so people are trying + + align:start position:0% +extra methyl groups so people are trying + + + align:start position:0% +extra methyl groups so people are trying +to sort of sort that out I don't think + + align:start position:0% +to sort of sort that out I don't think + + + align:start position:0% +to sort of sort that out I don't think +we really know but how well so they had + + align:start position:0% +we really know but how well so they had + + + align:start position:0% +we really know but how well so they had +so you're right they use sterols + + align:start position:0% +so you're right they use sterols + + + align:start position:0% +so you're right they use sterols +they didn't use that they didn't see + + align:start position:0% +they didn't use that they didn't see + + + align:start position:0% +they didn't use that they didn't see +very much difference with the Searles + + align:start position:0% +very much difference with the Searles + + + align:start position:0% +very much difference with the Searles +what was the other way which is sort of + + align:start position:0% +what was the other way which is sort of + + + align:start position:0% +what was the other way which is sort of +unusual that they added cholesterol back + + align:start position:0% +unusual that they added cholesterol back + + + align:start position:0% +unusual that they added cholesterol back +into this system so they could add it + + align:start position:0% +into this system so they could add it + + + align:start position:0% +into this system so they could add it +back with the methyl cyclodextrin they + + align:start position:0% +back with the methyl cyclodextrin they + + + align:start position:0% +back with the methyl cyclodextrin they +told you that that worked and if you + + align:start position:0% +told you that that worked and if you + + + align:start position:0% +told you that that worked and if you +believe that then and you look at the + + align:start position:0% +believe that then and you look at the + + + align:start position:0% +believe that then and you look at the +data it looked like that was happening + + align:start position:0% + + + + align:start position:0% + +nobody remembers okay well we'll get to + + align:start position:0% +nobody remembers okay well we'll get to + + + align:start position:0% +nobody remembers okay well we'll get to +that in a little bit okay so the + + align:start position:0% +that in a little bit okay so the + + + align:start position:0% +that in a little bit okay so the +question we're focusing on is what are + + align:start position:0% +question we're focusing on is what are + + + align:start position:0% +question we're focusing on is what are +the changes in concentrations of + + align:start position:0% +the changes in concentrations of + + + align:start position:0% +the changes in concentrations of +cholesterol in the ER okay so what + + align:start position:0% +cholesterol in the ER okay so what + + + align:start position:0% +cholesterol in the ER okay so what +method did they use to try to separate + + align:start position:0% +method did they use to try to separate + + + align:start position:0% +method did they use to try to separate +the ER membranes from all the other + + align:start position:0% +the ER membranes from all the other + + + align:start position:0% +the ER membranes from all the other +membranes they didn't separated the what + + align:start position:0% + + + + align:start position:0% + +a so that's good you can separate out + + align:start position:0% +a so that's good you can separate out + + + align:start position:0% +a so that's good you can separate out +the nucleus and you could do that by + + align:start position:0% +the nucleus and you could do that by + + + align:start position:0% +the nucleus and you could do that by +ultracentrifugation we've seen that used + + align:start position:0% +ultracentrifugation we've seen that used + + + align:start position:0% +ultracentrifugation we've seen that used +a number different kinds of + + align:start position:0% +a number different kinds of + + + align:start position:0% +a number different kinds of +ultracentrifugation we've seen the + + align:start position:0% +ultracentrifugation we've seen the + + + align:start position:0% +ultracentrifugation we've seen the +different particles that so lipoproteins + + align:start position:0% +different particles that so lipoproteins + + + align:start position:0% +different particles that so lipoproteins +in the diet how did how do we separate + + align:start position:0% +in the diet how did how do we separate + + + align:start position:0% +in the diet how did how do we separate +those we talked about that class briefly + + align:start position:0% +those we talked about that class briefly + + + align:start position:0% +those we talked about that class briefly +we did we have you haven't had any + + align:start position:0% +we did we have you haven't had any + + + align:start position:0% +we did we have you haven't had any +papers to read but what was some method + + align:start position:0% +papers to read but what was some method + + + align:start position:0% +papers to read but what was some method +of separation if you look at all those + + align:start position:0% +of separation if you look at all those + + + align:start position:0% +of separation if you look at all those +particles remember we had a little + + align:start position:0% +particles remember we had a little + + + align:start position:0% +particles remember we had a little +cartoon of all the particles and we + + align:start position:0% +cartoon of all the particles and we + + + align:start position:0% +cartoon of all the particles and we +focused on LDL which is the particle + + align:start position:0% +focused on LDL which is the particle + + + align:start position:0% +focused on LDL which is the particle +that has the most cholesterol so that's + + align:start position:0% +that has the most cholesterol so that's + + + align:start position:0% +that has the most cholesterol so that's +where everybody's focusing on that what + + align:start position:0% +where everybody's focusing on that what + + + align:start position:0% +where everybody's focusing on that what +was the basis of the separation whistle + + align:start position:0% +was the basis of the separation whistle + + + align:start position:0% +was the basis of the separation whistle +what you need + + align:start position:0% + + + + align:start position:0% + +yeah ultracentrifugation but what was it + + align:start position:0% +yeah ultracentrifugation but what was it + + + align:start position:0% +yeah ultracentrifugation but what was it +how did okay yeah okay so they have + + align:start position:0% +how did okay yeah okay so they have + + + align:start position:0% +how did okay yeah okay so they have +different density gradients okay and so + + align:start position:0% +different density gradients okay and so + + + align:start position:0% +different density gradients okay and so +that's going to be a key thing and + + align:start position:0% +that's going to be a key thing and + + + align:start position:0% +that's going to be a key thing and +that's because if you look at the + + align:start position:0% +that's because if you look at the + + + align:start position:0% +that's because if you look at the +composition and they have different + + align:start position:0% +composition and they have different + + + align:start position:0% +composition and they have different +amounts of proteins different amounts of + + align:start position:0% +amounts of proteins different amounts of + + + align:start position:0% +amounts of proteins different amounts of +fats and they have different they float + + align:start position:0% +fats and they have different they float + + + align:start position:0% +fats and they have different they float +differently so that's the method that + + align:start position:0% +differently so that's the method that + + + align:start position:0% +differently so that's the method that +they're gonna use here is that a good + + align:start position:0% +they're gonna use here is that a good + + + align:start position:0% +they're gonna use here is that a good +method can you think of a better method + + align:start position:0% +method can you think of a better method + + + align:start position:0% +method can you think of a better method +so in order to sort of understand the + + align:start position:0% +so in order to sort of understand the + + + align:start position:0% +so in order to sort of understand the +switch for cholesterol you got to be + + align:start position:0% +switch for cholesterol you got to be + + + align:start position:0% +switch for cholesterol you got to be +able to measure the changes in + + align:start position:0% +able to measure the changes in + + + align:start position:0% +able to measure the changes in +cholesterol right not an easy problem + + align:start position:0% +cholesterol right not an easy problem + + + align:start position:0% +cholesterol right not an easy problem +because cholesterol is really insoluble + + align:start position:0% +because cholesterol is really insoluble + + + align:start position:0% +because cholesterol is really insoluble +in everything okay and so how much is + + align:start position:0% +in everything okay and so how much is + + + align:start position:0% +in everything okay and so how much is +really in there and how does it change + + align:start position:0% +really in there and how does it change + + + align:start position:0% +really in there and how does it change +under different sets of conditions so is + + align:start position:0% +under different sets of conditions so is + + + align:start position:0% +under different sets of conditions so is +this a good method what do you think + + align:start position:0% +this a good method what do you think + + + align:start position:0% +this a good method what do you think +we'll look at the the method and a + + align:start position:0% +we'll look at the the method and a + + + align:start position:0% +we'll look at the the method and a +little more detail woman when I pull up + + align:start position:0% +little more detail woman when I pull up + + + align:start position:0% +little more detail woman when I pull up +the figures but what did you think when + + align:start position:0% +the figures but what did you think when + + + align:start position:0% +the figures but what did you think when +you read the when you read the paper + + align:start position:0% + + + + align:start position:0% + +yeah so so the question is you know you + + align:start position:0% +yeah so so the question is you know you + + + align:start position:0% +yeah so so the question is you know you +could you separate I mean even + + align:start position:0% +could you separate I mean even + + + align:start position:0% +could you separate I mean even +separating the nucleus from the cytosol + + align:start position:0% +separating the nucleus from the cytosol + + + align:start position:0% +separating the nucleus from the cytosol +it's not so trivial okay by these + + align:start position:0% +it's not so trivial okay by these + + + align:start position:0% +it's not so trivial okay by these +methods and really gross methods and + + align:start position:0% +methods and really gross methods and + + + align:start position:0% +methods and really gross methods and +during the centrifugation things diffuse + + align:start position:0% +during the centrifugation things diffuse + + + align:start position:0% +during the centrifugation things diffuse +you know so if you ever enclosed + + align:start position:0% +you know so if you ever enclosed + + + align:start position:0% +you know so if you ever enclosed +separations its equilibrate again so + + align:start position:0% +separations its equilibrate again so + + + align:start position:0% +separations its equilibrate again so +you're getting your proteins or your + + align:start position:0% +you're getting your proteins or your + + + align:start position:0% +you're getting your proteins or your +lipids are spreading out is there + + align:start position:0% +lipids are spreading out is there + + + align:start position:0% +lipids are spreading out is there +anything else any of you experience with + + align:start position:0% +anything else any of you experience with + + + align:start position:0% +anything else any of you experience with +insoluble I mean this is where you we're + + align:start position:0% +insoluble I mean this is where you we're + + + align:start position:0% +insoluble I mean this is where you we're +dealing with it's an insoluble mess and + + align:start position:0% +dealing with it's an insoluble mess and + + + align:start position:0% +dealing with it's an insoluble mess and +how do you how do you separate things in + + align:start position:0% +how do you how do you separate things in + + + align:start position:0% +how do you how do you separate things in +a way that you have control over it so + + align:start position:0% +a way that you have control over it so + + + align:start position:0% +a way that you have control over it so +that you can address the key questions + + align:start position:0% +that you can address the key questions + + + align:start position:0% +that you can address the key questions +in this paper nobody nobody thought + + align:start position:0% +in this paper nobody nobody thought + + + align:start position:0% +in this paper nobody nobody thought +about anything else you did you like + + align:start position:0% +about anything else you did you like + + + align:start position:0% +about anything else you did you like +this method we convinced by the data + + align:start position:0% + + + + align:start position:0% + +yeah so so so that's an incredibly + + align:start position:0% +yeah so so so that's an incredibly + + + align:start position:0% +yeah so so so that's an incredibly +important question because lipids + + align:start position:0% +important question because lipids + + + align:start position:0% +important question because lipids +confused + + align:start position:0% +confused + + + align:start position:0% +confused +you know they could mix the question is + + align:start position:0% +you know they could mix the question is + + + align:start position:0% +you know they could mix the question is +one of the rate constants for all of + + align:start position:0% +one of the rate constants for all of + + + align:start position:0% +one of the rate constants for all of +that and we don't really teach very much + + align:start position:0% +that and we don't really teach very much + + + align:start position:0% +that and we don't really teach very much +in the introductory courses about lipids + + align:start position:0% +in the introductory courses about lipids + + + align:start position:0% +in the introductory courses about lipids +and their partitioning between other + + align:start position:0% +and their partitioning between other + + + align:start position:0% +and their partitioning between other +membranes and fusion and all that stuff + + align:start position:0% +membranes and fusion and all that stuff + + + align:start position:0% +membranes and fusion and all that stuff +but if you think about it that's what + + align:start position:0% +but if you think about it that's what + + + align:start position:0% +but if you think about it that's what +the cell is right you get a plasma + + align:start position:0% +the cell is right you get a plasma + + + align:start position:0% +the cell is right you get a plasma +membrane and all these membranes around + + align:start position:0% +membrane and all these membranes around + + + align:start position:0% +membrane and all these membranes around +all these little organelles that's sort + + align:start position:0% +all these little organelles that's sort + + + align:start position:0% +all these little organelles that's sort +of an amazing observation and we've seen + + align:start position:0% +of an amazing observation and we've seen + + + align:start position:0% +of an amazing observation and we've seen +in class already what have we seen to + + align:start position:0% +in class already what have we seen to + + + align:start position:0% +in class already what have we seen to +get an LDL receptor from here to the + + align:start position:0% +get an LDL receptor from here to the + + + align:start position:0% +get an LDL receptor from here to the +plasma membrane how do we have to do + + align:start position:0% +plasma membrane how do we have to do + + + align:start position:0% +plasma membrane how do we have to do +that we had to use these little vesicles + + align:start position:0% +that we had to use these little vesicles + + + align:start position:0% +that we had to use these little vesicles +right so you're you're generating + + align:start position:0% +right so you're you're generating + + + align:start position:0% +right so you're you're generating +something over here it goes through the + + align:start position:0% +something over here it goes through the + + + align:start position:0% +something over here it goes through the +golgi stack again another set of + + align:start position:0% +golgi stack again another set of + + + align:start position:0% +golgi stack again another set of +membranes it's got to come out the + + align:start position:0% +membranes it's got to come out the + + + align:start position:0% +membranes it's got to come out the +different levels of the golgi stack and + + align:start position:0% +different levels of the golgi stack and + + + align:start position:0% +different levels of the golgi stack and +then it's still gotta get into the + + align:start position:0% +then it's still gotta get into the + + + align:start position:0% +then it's still gotta get into the +plasma membrane infused and dump its + + align:start position:0% +plasma membrane infused and dump its + + + align:start position:0% +plasma membrane infused and dump its +cargo so I think it's sort of an amazing + + align:start position:0% +cargo so I think it's sort of an amazing + + + align:start position:0% +cargo so I think it's sort of an amazing +process and people interested in + + align:start position:0% +process and people interested in + + + align:start position:0% +process and people interested in +evolution this is one of the major + + align:start position:0% +evolution this is one of the major + + + align:start position:0% +evolution this is one of the major +things people are focused on is how do + + align:start position:0% +things people are focused on is how do + + + align:start position:0% +things people are focused on is how do +you how can you make cells a little fake + + align:start position:0% +you how can you make cells a little fake + + + align:start position:0% +you how can you make cells a little fake +cells artificial cells that can + + align:start position:0% +cells artificial cells that can + + + align:start position:0% +cells artificial cells that can +replicate themselves you can make it and + + align:start position:0% +replicate themselves you can make it and + + + align:start position:0% +replicate themselves you can make it and +they can they're gonna have to divide + + align:start position:0% +they can they're gonna have to divide + + + align:start position:0% +they can they're gonna have to divide +and infuse and it's exactly the same + + align:start position:0% +and infuse and it's exactly the same + + + align:start position:0% +and infuse and it's exactly the same +problem here and so this question of + + align:start position:0% +problem here and so this question of + + + align:start position:0% +problem here and so this question of +fluidity is an extremely important + + align:start position:0% +fluidity is an extremely important + + + align:start position:0% +fluidity is an extremely important +question and a lot of people that focus + + align:start position:0% +question and a lot of people that focus + + + align:start position:0% +question and a lot of people that focus +on lipids which is not a popular target + + align:start position:0% +on lipids which is not a popular target + + + align:start position:0% +on lipids which is not a popular target +a popular thing to study because it's so + + align:start position:0% +a popular thing to study because it's so + + + align:start position:0% +a popular thing to study because it's so +hard it's incredibly important and + + align:start position:0% +hard it's incredibly important and + + + align:start position:0% +hard it's incredibly important and +people that look at membrane proteins + + align:start position:0% +people that look at membrane proteins + + + align:start position:0% +people that look at membrane proteins +you know they almost always have lipids + + align:start position:0% +you know they almost always have lipids + + + align:start position:0% +you know they almost always have lipids +on them but and then when you do them + + align:start position:0% +on them but and then when you do them + + + align:start position:0% +on them but and then when you do them +yourself you have a detergent which is + + align:start position:0% +yourself you have a detergent which is + + + align:start position:0% +yourself you have a detergent which is +not a real lipid and does that change + + align:start position:0% +not a real lipid and does that change + + + align:start position:0% +not a real lipid and does that change +the property so all of these questions I + + align:start position:0% +the property so all of these questions I + + + align:start position:0% +the property so all of these questions I +think are really sort of central to what + + align:start position:0% +think are really sort of central to what + + + align:start position:0% +think are really sort of central to what +happens in the membranes which is a + + align:start position:0% +happens in the membranes which is a + + + align:start position:0% +happens in the membranes which is a +a lot of stuff inside the cell so I + + align:start position:0% +a lot of stuff inside the cell so I + + + align:start position:0% +a lot of stuff inside the cell so I +think it's good to question what they + + align:start position:0% +think it's good to question what they + + + align:start position:0% +think it's good to question what they +did I think their results turned out to + + align:start position:0% +did I think their results turned out to + + + align:start position:0% +did I think their results turned out to +be quite interesting okay but we'll come + + align:start position:0% +be quite interesting okay but we'll come + + + align:start position:0% +be quite interesting okay but we'll come +back I think it that was a hard problem + + align:start position:0% +back I think it that was a hard problem + + + align:start position:0% +back I think it that was a hard problem +and so we'll come back and we'll look at + + align:start position:0% +and so we'll come back and we'll look at + + + align:start position:0% +and so we'll come back and we'll look at +this and so then let's give let's say + + align:start position:0% +this and so then let's give let's say + + + align:start position:0% +this and so then let's give let's say +that we could end up separating things + + align:start position:0% +that we could end up separating things + + + align:start position:0% +that we could end up separating things +then the question is what was the key + + align:start position:0% +then the question is what was the key + + + align:start position:0% +then the question is what was the key +type of measurement they made where they + + align:start position:0% +type of measurement they made where they + + + align:start position:0% +type of measurement they made where they +could correlate the changes that it + + align:start position:0% +could correlate the changes that it + + + align:start position:0% +could correlate the changes that it +should correlate the changes in + + align:start position:0% +should correlate the changes in + + + align:start position:0% +should correlate the changes in +cholesterol levels we talked about you + + align:start position:0% +cholesterol levels we talked about you + + + align:start position:0% +cholesterol levels we talked about you +couldn't control perhaps the cholesterol + + align:start position:0% +couldn't control perhaps the cholesterol + + + align:start position:0% +couldn't control perhaps the cholesterol +levels with the cyclodextrin but then + + align:start position:0% +levels with the cyclodextrin but then + + + align:start position:0% +levels with the cyclodextrin but then +how did they correlate the changes in + + align:start position:0% +how did they correlate the changes in + + + align:start position:0% +how did they correlate the changes in +the cholesterol levels in the membrane + + align:start position:0% +the cholesterol levels in the membrane + + + align:start position:0% +the cholesterol levels in the membrane +with this transcriptional regulation + + align:start position:0% +with this transcriptional regulation + + + align:start position:0% +with this transcriptional regulation +okay and so which that is what happens + + align:start position:0% +okay and so which that is what happens + + + align:start position:0% +okay and so which that is what happens +with the steroid responsive element + + align:start position:0% +with the steroid responsive element + + + align:start position:0% +with the steroid responsive element +binding protein the transcription factor + + align:start position:0% +binding protein the transcription factor + + + align:start position:0% +binding protein the transcription factor +so what happens in that process what + + align:start position:0% +so what happens in that process what + + + align:start position:0% +so what happens in that process what +what are the changes in the srebp + + align:start position:0% +what are the changes in the srebp + + + align:start position:0% +what are the changes in the srebp +dependent on the concentrations of the + + align:start position:0% +dependent on the concentrations of the + + + align:start position:0% +dependent on the concentrations of the +cholesterol and how did they take + + align:start position:0% +cholesterol and how did they take + + + align:start position:0% +cholesterol and how did they take +advantage of that in answering this + + align:start position:0% +advantage of that in answering this + + + align:start position:0% +advantage of that in answering this +question about whether what the + + align:start position:0% +question about whether what the + + + align:start position:0% +question about whether what the +cholesterol levels were that allows you + + align:start position:0% +cholesterol levels were that allows you + + + align:start position:0% +cholesterol levels were that allows you +to turn on transcription of LDL receptor + + align:start position:0% +to turn on transcription of LDL receptor + + + align:start position:0% +to turn on transcription of LDL receptor +and hmg-coa reductase so what's the + + align:start position:0% +and hmg-coa reductase so what's the + + + align:start position:0% +and hmg-coa reductase so what's the +major a say we'll look at that as well + + align:start position:0% +major a say we'll look at that as well + + + align:start position:0% +major a say we'll look at that as well +so if you go back and you look at the + + align:start position:0% +so if you go back and you look at the + + + align:start position:0% +so if you go back and you look at the +model what happens in this model all + + align:start position:0% +model what happens in this model all + + + align:start position:0% +model what happens in this model all +right here we go + + align:start position:0% +right here we go + + + align:start position:0% +right here we go +what happens in this model what's + + align:start position:0% +what happens in this model what's + + + align:start position:0% +what happens in this model what's +happening to srebp + + align:start position:0% + + + + align:start position:0% + +now this scalp scalp that's this guy + + align:start position:0% +now this scalp scalp that's this guy + + + align:start position:0% +now this scalp scalp that's this guy +okay so scalp that's a key player that's + + align:start position:0% +okay so scalp that's a key player that's + + + align:start position:0% +okay so scalp that's a key player that's +what we talked about I know the names + + align:start position:0% +what we talked about I know the names + + + align:start position:0% +what we talked about I know the names +are all confusing so you're going to + + align:start position:0% +are all confusing so you're going to + + + align:start position:0% +are all confusing so you're going to +need to write these down good + + align:start position:0% +need to write these down good + + + align:start position:0% +need to write these down good +remember the names are very confusing + + align:start position:0% +remember the names are very confusing + + + align:start position:0% +remember the names are very confusing +yeah great all right + + align:start position:0% +yeah great all right + + + align:start position:0% +yeah great all right +so how could you take advantage of that + + align:start position:0% +so how could you take advantage of that + + + align:start position:0% +so how could you take advantage of that +that that's this is the key observation + + align:start position:0% +that that's this is the key observation + + + align:start position:0% +that that's this is the key observation +that they're taking advantage of to ask + + align:start position:0% +that they're taking advantage of to ask + + + align:start position:0% +that they're taking advantage of to ask +the question since this whole process is + + align:start position:0% +the question since this whole process is + + + align:start position:0% +the question since this whole process is +dependent on the concentration of + + align:start position:0% +dependent on the concentration of + + + align:start position:0% +dependent on the concentration of +cholesterol you if you have high + + align:start position:0% +cholesterol you if you have high + + + align:start position:0% +cholesterol you if you have high +cholesterol there's no way you want this + + align:start position:0% +cholesterol there's no way you want this + + + align:start position:0% +cholesterol there's no way you want this +to happen + + align:start position:0% +to happen + + + align:start position:0% +to happen +you want to shut it off if you have low + + align:start position:0% +you want to shut it off if you have low + + + align:start position:0% +you want to shut it off if you have low +cholesterol you want to turn these guys + + align:start position:0% +cholesterol you want to turn these guys + + + align:start position:0% +cholesterol you want to turn these guys +on okay so this movement is the key and + + align:start position:0% +on okay so this movement is the key and + + + align:start position:0% +on okay so this movement is the key and +what do we see if if we look at what + + align:start position:0% +what do we see if if we look at what + + + align:start position:0% +what do we see if if we look at what +happens to this protein srebp what + + align:start position:0% +happens to this protein srebp what + + + align:start position:0% +happens to this protein srebp what +happens to it during this process it + + align:start position:0% +happens to it during this process it + + + align:start position:0% +happens to it during this process it +gets cleaved and what happens - how + + align:start position:0% +gets cleaved and what happens - how + + + align:start position:0% +gets cleaved and what happens - how +could you monitor - that cleavage how do + + align:start position:0% +could you monitor - that cleavage how do + + + align:start position:0% +could you monitor - that cleavage how do +they do it in the paper they couldn't + + align:start position:0% +they do it in the paper they couldn't + + + align:start position:0% +they do it in the paper they couldn't +use a floor where they didn't do that + + align:start position:0% +use a floor where they didn't do that + + + align:start position:0% +use a floor where they didn't do that +they did a what + + align:start position:0% + + + + align:start position:0% + +yeah so they can just separate by a gel + + align:start position:0% +yeah so they can just separate by a gel + + + align:start position:0% +yeah so they can just separate by a gel +so to me this is an actually quite an + + align:start position:0% +so to me this is an actually quite an + + + align:start position:0% +so to me this is an actually quite an +easy a se because if you look at this I + + align:start position:0% +easy a se because if you look at this I + + + align:start position:0% +easy a se because if you look at this I +don't remember what the molecular weight + + align:start position:0% +don't remember what the molecular weight + + + align:start position:0% +don't remember what the molecular weight +is but it's a lot smaller over here and + + align:start position:0% +is but it's a lot smaller over here and + + + align:start position:0% +is but it's a lot smaller over here and +so that turns out to be a great I'll say + + align:start position:0% +so that turns out to be a great I'll say + + + align:start position:0% +so that turns out to be a great I'll say +so that part of that that part of their + + align:start position:0% +so that part of that that part of their + + + align:start position:0% +so that part of that that part of their +analysis I think was a really smart part + + align:start position:0% +analysis I think was a really smart part + + + align:start position:0% +analysis I think was a really smart part +of the analysis and so then the question + + align:start position:0% +of the analysis and so then the question + + + align:start position:0% +of the analysis and so then the question +becomes can you quantitate all of this + + align:start position:0% +becomes can you quantitate all of this + + + align:start position:0% +becomes can you quantitate all of this +so if you have a lot of cholesterol this + + align:start position:0% +so if you have a lot of cholesterol this + + + align:start position:0% +so if you have a lot of cholesterol this +doesn't happen and so everything is + + align:start position:0% +doesn't happen and so everything is + + + align:start position:0% +doesn't happen and so everything is +bigger and resides in the membrane you + + align:start position:0% +bigger and resides in the membrane you + + + align:start position:0% +bigger and resides in the membrane you +could even probably look at that whereas + + align:start position:0% +could even probably look at that whereas + + + align:start position:0% +could even probably look at that whereas +when the cholesterol is really lower + + align:start position:0% +when the cholesterol is really lower + + + align:start position:0% +when the cholesterol is really lower +things things go there and it's + + align:start position:0% +things things go there and it's + + + align:start position:0% +things things go there and it's +everything in between the question is + + align:start position:0% +everything in between the question is + + + align:start position:0% +everything in between the question is +what is the concept can you measure if + + align:start position:0% +what is the concept can you measure if + + + align:start position:0% +what is the concept can you measure if +you have X percent cholesterol in the ER + + align:start position:0% +you have X percent cholesterol in the ER + + + align:start position:0% +you have X percent cholesterol in the ER +how much do you have to decrease it to + + align:start position:0% +how much do you have to decrease it to + + + align:start position:0% +how much do you have to decrease it to +see a change or switch and where this + + align:start position:0% +see a change or switch and where this + + + align:start position:0% +see a change or switch and where this +protein goes so I think the experiment + + align:start position:0% +protein goes so I think the experiment + + + align:start position:0% +protein goes so I think the experiment +the experimental design is actually + + align:start position:0% +the experimental design is actually + + + align:start position:0% +the experimental design is actually +amazingly creative okay but then you + + align:start position:0% +amazingly creative okay but then you + + + align:start position:0% +amazingly creative okay but then you +sell you see the data off the other side + + align:start position:0% +sell you see the data off the other side + + + align:start position:0% +sell you see the data off the other side +and what I want to do now is is sort of + + align:start position:0% +and what I want to do now is is sort of + + + align:start position:0% +and what I want to do now is is sort of +focus on what what the issues are okay + + align:start position:0% +focus on what what the issues are okay + + + align:start position:0% +focus on what what the issues are okay +so we're going to come back and look at + + align:start position:0% +so we're going to come back and look at + + + align:start position:0% +so we're going to come back and look at +how did they look at srebp so you could + + align:start position:0% +how did they look at srebp so you could + + + align:start position:0% +how did they look at srebp so you could +look at this a number of ways you could + + align:start position:0% +look at this a number of ways you could + + + align:start position:0% +look at this a number of ways you could +look at this by protein gel directly how + + align:start position:0% +look at this by protein gel directly how + + + align:start position:0% +look at this by protein gel directly how +else do people look at proteins using + + align:start position:0% +else do people look at proteins using + + + align:start position:0% +else do people look at proteins using +westerns what's the Western anybody know + + align:start position:0% +westerns what's the Western anybody know + + + align:start position:0% +westerns what's the Western anybody know +what a Western analysis is I didn't I + + align:start position:0% +what a Western analysis is I didn't I + + + align:start position:0% +what a Western analysis is I didn't I +asked you that a beginning of class + + align:start position:0% + + + + align:start position:0% + +how else do you detect proteins you've + + align:start position:0% +how else do you detect proteins you've + + + align:start position:0% +how else do you detect proteins you've +seen this on the first half of the + + align:start position:0% +seen this on the first half of the + + + align:start position:0% +seen this on the first half of the +semester a lot yeah antibodies so if you + + align:start position:0% +semester a lot yeah antibodies so if you + + + align:start position:0% +semester a lot yeah antibodies so if you +have any antibodies to this and we'll + + align:start position:0% +have any antibodies to this and we'll + + + align:start position:0% +have any antibodies to this and we'll +talk about that because the Western + + align:start position:0% +talk about that because the Western + + + align:start position:0% +talk about that because the Western +analysis which people use all the time + + align:start position:0% +analysis which people use all the time + + + align:start position:0% +analysis which people use all the time +and you can't pit there's so many issues + + align:start position:0% +and you can't pit there's so many issues + + + align:start position:0% +and you can't pit there's so many issues +with it that I think I want you to think + + align:start position:0% +with it that I think I want you to think + + + align:start position:0% +with it that I think I want you to think +about what the issues are okay and then + + align:start position:0% +about what the issues are okay and then + + + align:start position:0% +about what the issues are okay and then +you correlate the two changing the + + align:start position:0% +you correlate the two changing the + + + align:start position:0% +you correlate the two changing the +levels of cholesterol which they measure + + align:start position:0% +levels of cholesterol which they measure + + + align:start position:0% +levels of cholesterol which they measure +by mass spec after separation and + + align:start position:0% +by mass spec after separation and + + + align:start position:0% +by mass spec after separation and +purification of lipids and the cleavage + + align:start position:0% +purification of lipids and the cleavage + + + align:start position:0% +purification of lipids and the cleavage +and then they plot the data and and + + align:start position:0% +and then they plot the data and and + + + align:start position:0% +and then they plot the data and and +that's where they got the analysis from + + align:start position:0% +that's where they got the analysis from + + + align:start position:0% +that's where they got the analysis from +okay so the first thing that you want to + + align:start position:0% +okay so the first thing that you want to + + + align:start position:0% +okay so the first thing that you want to +do the first thing and the key to + + align:start position:0% +do the first thing and the key to + + + align:start position:0% +do the first thing and the key to +everything is separation of the + + align:start position:0% +everything is separation of the + + + align:start position:0% +everything is separation of the +membranes okay and so this is a cartoon + + align:start position:0% +membranes okay and so this is a cartoon + + + align:start position:0% +membranes okay and so this is a cartoon +of when you put something you load + + align:start position:0% +of when you put something you load + + + align:start position:0% +of when you put something you load +something on the top and you have a + + align:start position:0% +something on the top and you have a + + + align:start position:0% +something on the top and you have a +gradient and the gradient could be made + + align:start position:0% +gradient and the gradient could be made + + + align:start position:0% +gradient and the gradient could be made +of a number of things have any of you + + align:start position:0% +of a number of things have any of you + + + align:start position:0% +of a number of things have any of you +ever run these kinds of gradients okay + + align:start position:0% +ever run these kinds of gradients okay + + + align:start position:0% +ever run these kinds of gradients okay +so you can make them out of glycerol you + + align:start position:0% +so you can make them out of glycerol you + + + align:start position:0% +so you can make them out of glycerol you +can make them less gross did anybody + + align:start position:0% +can make them less gross did anybody + + + align:start position:0% +can make them less gross did anybody +look at how these gradients for me did + + align:start position:0% +look at how these gradients for me did + + + align:start position:0% +look at how these gradients for me did +you read the experimental carefully + + align:start position:0% +you read the experimental carefully + + + align:start position:0% +you read the experimental carefully +enough to look at that + + align:start position:0% + + + + align:start position:0% + +yeah how do you make a sucrose gradient + + align:start position:0% + + + + align:start position:0% + +you have no idea but I said huh yeah so + + align:start position:0% +you have no idea but I said huh yeah so + + + align:start position:0% +you have no idea but I said huh yeah so +layering so what you'd really like to do + + align:start position:0% +layering so what you'd really like to do + + + align:start position:0% +layering so what you'd really like to do +is have a continuous gradient or + + align:start position:0% +is have a continuous gradient or + + + align:start position:0% +is have a continuous gradient or +something but that sucrose is incredibly + + align:start position:0% +something but that sucrose is incredibly + + + align:start position:0% +something but that sucrose is incredibly +viscous so if you were trying to make a + + align:start position:0% +viscous so if you were trying to make a + + + align:start position:0% +viscous so if you were trying to make a +linear gradient which you could do by + + align:start position:0% +linear gradient which you could do by + + + align:start position:0% +linear gradient which you could do by +mixing two things of different + + align:start position:0% +mixing two things of different + + + align:start position:0% +mixing two things of different +concentrations if you could get them to + + align:start position:0% +concentrations if you could get them to + + + align:start position:0% +concentrations if you could get them to +stir really well and then add it in and + + align:start position:0% +stir really well and then add it in and + + + align:start position:0% +stir really well and then add it in and +you could generate a gradient but it's + + align:start position:0% +you could generate a gradient but it's + + + align:start position:0% +you could generate a gradient but it's +so hard to do that what happens is they + + align:start position:0% +so hard to do that what happens is they + + + align:start position:0% +so hard to do that what happens is they +end up layering it so they make x % y % + + align:start position:0% +end up layering it so they make x % y % + + + align:start position:0% +end up layering it so they make x % y % +z percent they put it down okay and then + + align:start position:0% +z percent they put it down okay and then + + + align:start position:0% +z percent they put it down okay and then +they try to layer something on top of it + + align:start position:0% +they try to layer something on top of it + + + align:start position:0% +they try to layer something on top of it +and then and so and then they put + + align:start position:0% +and then and so and then they put + + + align:start position:0% +and then and so and then they put +whatever they interested in at the top + + align:start position:0% +whatever they interested in at the top + + + align:start position:0% +whatever they interested in at the top +and then they they centrifuge it okay so + + align:start position:0% +and then they they centrifuge it okay so + + + align:start position:0% +and then they they centrifuge it okay so +what are the issues is this do you think + + align:start position:0% +what are the issues is this do you think + + + align:start position:0% +what are the issues is this do you think +this is what the gradient would look + + align:start position:0% +this is what the gradient would look + + + align:start position:0% +this is what the gradient would look +like well so what are the issues when + + align:start position:0% +like well so what are the issues when + + + align:start position:0% +like well so what are the issues when +you're doing this when you when you + + align:start position:0% +you're doing this when you when you + + + align:start position:0% +you're doing this when you when you +layer it so and this is why the data + + align:start position:0% +layer it so and this is why the data + + + align:start position:0% +layer it so and this is why the data +which we'll talk about in a minute is + + align:start position:0% +which we'll talk about in a minute is + + + align:start position:0% +which we'll talk about in a minute is +that is the data part of the issue is + + align:start position:0% +that is the data part of the issue is + + + align:start position:0% +that is the data part of the issue is +this method that's why you need to think + + align:start position:0% +this method that's why you need to think + + + align:start position:0% +this method that's why you need to think +about the method and there are better + + align:start position:0% +about the method and there are better + + + align:start position:0% +about the method and there are better +ways to do this and it really depends on + + align:start position:0% +ways to do this and it really depends on + + + align:start position:0% +ways to do this and it really depends on +what you're trying to separate you know + + align:start position:0% +what you're trying to separate you know + + + align:start position:0% +what you're trying to separate you know +so if this ban there was a little say + + align:start position:0% +so if this ban there was a little say + + + align:start position:0% +so if this ban there was a little say +these were two bands you wouldn't really + + align:start position:0% +these were two bands you wouldn't really + + + align:start position:0% +these were two bands you wouldn't really +get very much separation at all if there + + align:start position:0% +get very much separation at all if there + + + align:start position:0% +get very much separation at all if there +were two separate things that sedimented + + align:start position:0% +were two separate things that sedimented + + + align:start position:0% +were two separate things that sedimented +under these conditions very close + + align:start position:0% +under these conditions very close + + + align:start position:0% +under these conditions very close +together okay so what would happen when + + align:start position:0% +together okay so what would happen when + + + align:start position:0% +together okay so what would happen when +you're sedimenting this I mean does + + align:start position:0% +you're sedimenting this I mean does + + + align:start position:0% +you're sedimenting this I mean does +anybody have any idea how long it takes + + align:start position:0% +anybody have any idea how long it takes + + + align:start position:0% +anybody have any idea how long it takes +do you think you'd do this in like a + + align:start position:0% +do you think you'd do this in like a + + + align:start position:0% +do you think you'd do this in like a +centrifuge just spin it for three + + align:start position:0% +centrifuge just spin it for three + + + align:start position:0% +centrifuge just spin it for three +minutes and then you know so it you + + align:start position:0% +minutes and then you know so it you + + + align:start position:0% +minutes and then you know so it you +sometimes you sediment these things for + + align:start position:0% +sometimes you sediment these things for + + + align:start position:0% +sometimes you sediment these things for +16 20 hours okay so what happens during + + align:start position:0% +16 20 hours okay so what happens during + + + align:start position:0% +16 20 hours okay so what happens during +the sedimentation that might make this + + align:start position:0% +the sedimentation that might make this + + + align:start position:0% +the sedimentation that might make this +more challenging in terms of separating + + align:start position:0% +more challenging in terms of separating + + + align:start position:0% +more challenging in terms of separating +what you want to separate yeah so + + align:start position:0% +what you want to separate yeah so + + + align:start position:0% +what you want to separate yeah so +exactly you have diffusion and even when + + align:start position:0% +exactly you have diffusion and even when + + + align:start position:0% +exactly you have diffusion and even when +you've layered things on top of each + + align:start position:0% +you've layered things on top of each + + + align:start position:0% +you've layered things on top of each +other like that you start to have + + align:start position:0% +other like that you start to have + + + align:start position:0% +other like that you start to have +diffusion and if you shake up the tube a + + align:start position:0% +diffusion and if you shake up the tube a + + + align:start position:0% +diffusion and if you shake up the tube a +little bit it's all over so how you + + align:start position:0% +little bit it's all over so how you + + + align:start position:0% +little bit it's all over so how you +prepare these things is not so true + + align:start position:0% +prepare these things is not so true + + + align:start position:0% +prepare these things is not so true +these people still use these methods but + + align:start position:0% +these people still use these methods but + + + align:start position:0% +these people still use these methods but +I would like to see better man + + align:start position:0% +I would like to see better man + + + align:start position:0% +I would like to see better man +and so they tried you know one method + + align:start position:0% +and so they tried you know one method + + + align:start position:0% +and so they tried you know one method +with sucrose and then they that wasn't + + align:start position:0% +with sucrose and then they that wasn't + + + align:start position:0% +with sucrose and then they that wasn't +good enough we'll look at the data so + + align:start position:0% +good enough we'll look at the data so + + + align:start position:0% +good enough we'll look at the data so +they went to a second method and you + + align:start position:0% +they went to a second method and you + + + align:start position:0% +they went to a second method and you +know where did they come up with this I + + align:start position:0% +know where did they come up with this I + + + align:start position:0% +know where did they come up with this I +have no idea where they came up with + + align:start position:0% +have no idea where they came up with + + + align:start position:0% +have no idea where they came up with +this but it was an MD PhD student in her + + align:start position:0% +this but it was an MD PhD student in her + + + align:start position:0% +this but it was an MD PhD student in her +class who has seen this in one of its + + align:start position:0% +class who has seen this in one of its + + + align:start position:0% +class who has seen this in one of its +classes and they use it in some blood + + align:start position:0% +classes and they use it in some blood + + + align:start position:0% +classes and they use it in some blood +tests so I think that's probably where + + align:start position:0% +tests so I think that's probably where + + + align:start position:0% +tests so I think that's probably where +these guys got it from because they're + + align:start position:0% +these guys got it from because they're + + + align:start position:0% +these guys got it from because they're +both MD and Brown and goes you know both + + align:start position:0% +both MD and Brown and goes you know both + + + align:start position:0% +both MD and Brown and goes you know both +MDS but again it's just another make way + + align:start position:0% +MDS but again it's just another make way + + + align:start position:0% +MDS but again it's just another make way +to make a gradient and I'm not sure why + + align:start position:0% +to make a gradient and I'm not sure why + + + align:start position:0% +to make a gradient and I'm not sure why +this gradient works as effectively as it + + align:start position:0% +this gradient works as effectively as it + + + align:start position:0% +this gradient works as effectively as it +does so but the first gradient didn't + + align:start position:0% +does so but the first gradient didn't + + + align:start position:0% +does so but the first gradient didn't +work so great and we'll look at that + + align:start position:0% +work so great and we'll look at that + + + align:start position:0% +work so great and we'll look at that +data so then they added on a few more + + align:start position:0% +data so then they added on a few more + + + align:start position:0% +data so then they added on a few more +steps because they weren't happy with + + align:start position:0% +steps because they weren't happy with + + + align:start position:0% +steps because they weren't happy with +the level of separation so looking at + + align:start position:0% +the level of separation so looking at + + + align:start position:0% +the level of separation so looking at +membranes I mean I think this is gonna + + align:start position:0% +membranes I mean I think this is gonna + + + align:start position:0% +membranes I mean I think this is gonna +be more and more looking at membranes + + align:start position:0% +be more and more looking at membranes + + + align:start position:0% +be more and more looking at membranes +because membranes you have two leaflets + + align:start position:0% +because membranes you have two leaflets + + + align:start position:0% +because membranes you have two leaflets +the lipids in the leaflets are different + + align:start position:0% +the lipids in the leaflets are different + + + align:start position:0% +the lipids in the leaflets are different +do you think that affects the biology I + + align:start position:0% +do you think that affects the biology I + + + align:start position:0% +do you think that affects the biology I +guarantee you it affects the biology and + + align:start position:0% +guarantee you it affects the biology and + + + align:start position:0% +guarantee you it affects the biology and +ways that we would really like to + + align:start position:0% +ways that we would really like to + + + align:start position:0% +ways that we would really like to +understand that I don't think we + + align:start position:0% +understand that I don't think we + + + align:start position:0% +understand that I don't think we +understand very well when you isolate a + + align:start position:0% +understand very well when you isolate a + + + align:start position:0% +understand very well when you isolate a +membrane protein have any of you ever + + align:start position:0% +membrane protein have any of you ever + + + align:start position:0% +membrane protein have any of you ever +isolated a membrane protein no so you + + align:start position:0% +isolated a membrane protein no so you + + + align:start position:0% +isolated a membrane protein no so you +have an insoluble much you know it's + + align:start position:0% +have an insoluble much you know it's + + + align:start position:0% +have an insoluble much you know it's +it's in this lipid system how do you + + align:start position:0% +it's in this lipid system how do you + + + align:start position:0% +it's in this lipid system how do you +think you get it out so you can go + + align:start position:0% +think you get it out so you can go + + + align:start position:0% +think you get it out so you can go +through the steps it a protein + + align:start position:0% +through the steps it a protein + + + align:start position:0% +through the steps it a protein +purification that you've talked about or + + align:start position:0% +purification that you've talked about or + + + align:start position:0% +purification that you've talked about or +you have probably done at an + + align:start position:0% +you have probably done at an + + + align:start position:0% +you have probably done at an +introductory lab course what is the + + align:start position:0% +introductory lab course what is the + + + align:start position:0% +introductory lab course what is the +first thing you need to do + + align:start position:0% + + + + align:start position:0% + +yeah soluble eyes and how do you soluble + + align:start position:0% +yeah soluble eyes and how do you soluble + + + align:start position:0% +yeah soluble eyes and how do you soluble +eyes it yeah with some kind of detergent + + align:start position:0% +eyes it yeah with some kind of detergent + + + align:start position:0% +eyes it yeah with some kind of detergent +it's sort of like what you saw with the + + align:start position:0% +it's sort of like what you saw with the + + + align:start position:0% +it's sort of like what you saw with the +chylomicrons right or the bile acids + + align:start position:0% +chylomicrons right or the bile acids + + + align:start position:0% +chylomicrons right or the bile acids +that we talked about so you can use + + align:start position:0% +that we talked about so you can use + + + align:start position:0% +that we talked about so you can use +different and people have their own + + align:start position:0% +different and people have their own + + + align:start position:0% +different and people have their own +favorite detergents but again that + + align:start position:0% +favorite detergents but again that + + + align:start position:0% +favorite detergents but again that +changes things but otherwise you can't + + align:start position:0% +changes things but otherwise you can't + + + align:start position:0% +changes things but otherwise you can't +purify purify anything unless you happen + + align:start position:0% +purify purify anything unless you happen + + + align:start position:0% +purify purify anything unless you happen +to have a membrane where you know it's + + align:start position:0% +to have a membrane where you know it's + + + align:start position:0% +to have a membrane where you know it's +the only protein in the membrane is so + + align:start position:0% +the only protein in the membrane is so + + + align:start position:0% +the only protein in the membrane is so +when you're interested in which of + + align:start position:0% +when you're interested in which of + + + align:start position:0% +when you're interested in which of +course doesn't exist + + align:start position:0% +course doesn't exist + + + align:start position:0% +course doesn't exist +okay so anyhow they went through that + + align:start position:0% +okay so anyhow they went through that + + + align:start position:0% +okay so anyhow they went through that +and then what do they end up seeing so + + align:start position:0% +and then what do they end up seeing so + + + align:start position:0% +and then what do they end up seeing so +they went through different steps and + + align:start position:0% +they went through different steps and + + + align:start position:0% +they went through different steps and +they separate they separate them into + + align:start position:0% +they separate they separate them into + + + align:start position:0% +they separate they separate them into +different the supernatant and/or the + + align:start position:0% +different the supernatant and/or the + + + align:start position:0% +different the supernatant and/or the +light and the heavy fraction membrane + + align:start position:0% +light and the heavy fraction membrane + + + align:start position:0% +light and the heavy fraction membrane +fractions and then they have to analyze + + align:start position:0% +fractions and then they have to analyze + + + align:start position:0% +fractions and then they have to analyze +it and so the question is how do they + + align:start position:0% +it and so the question is how do they + + + align:start position:0% +it and so the question is how do they +analyze to tell how well these + + align:start position:0% +analyze to tell how well these + + + align:start position:0% +analyze to tell how well these +separations actually worked what was the + + align:start position:0% +separations actually worked what was the + + + align:start position:0% +separations actually worked what was the +method that they did to determine + + align:start position:0% +method that they did to determine + + + align:start position:0% +method that they did to determine +whether they separated the ER from the + + align:start position:0% +whether they separated the ER from the + + + align:start position:0% +whether they separated the ER from the +plasma membrane from the golgi stacks + + align:start position:0% +plasma membrane from the golgi stacks + + + align:start position:0% +plasma membrane from the golgi stacks +from the lysosomes from the peri auxes + + align:start position:0% +from the lysosomes from the peri auxes + + + align:start position:0% +from the lysosomes from the peri auxes +ohms okay so they have all we have all + + align:start position:0% +ohms okay so they have all we have all + + + align:start position:0% +ohms okay so they have all we have all +these little organelles in there what + + align:start position:0% +these little organelles in there what + + + align:start position:0% +these little organelles in there what +did they do to to test each one of these + + align:start position:0% +did they do to to test each one of these + + + align:start position:0% +did they do to to test each one of these +fractions okay let me ask you this + + align:start position:0% +fractions okay let me ask you this + + + align:start position:0% +fractions okay let me ask you this +question how did they get how do you + + align:start position:0% +question how did they get how do you + + + align:start position:0% +question how did they get how do you +think they got the infirmity réalité of + + align:start position:0% +think they got the infirmity réalité of + + + align:start position:0% +think they got the infirmity réalité of +these gradients to do the experiments + + align:start position:0% +these gradients to do the experiments + + + align:start position:0% +these gradients to do the experiments +that I was just talking about so they + + align:start position:0% +that I was just talking about so they + + + align:start position:0% +that I was just talking about so they +want to analyze what's in each of these + + align:start position:0% +want to analyze what's in each of these + + + align:start position:0% +want to analyze what's in each of these +bands okay how do they get it out of + + align:start position:0% +bands okay how do they get it out of + + + align:start position:0% +bands okay how do they get it out of +this tube + + align:start position:0% + + + + align:start position:0% + +so what do you think you just stick it + + align:start position:0% +so what do you think you just stick it + + + align:start position:0% +so what do you think you just stick it +down in and suck it out well I mean you + + align:start position:0% +down in and suck it out well I mean you + + + align:start position:0% +down in and suck it out well I mean you +know so what do you think say you could + + align:start position:0% +know so what do you think say you could + + + align:start position:0% +know so what do you think say you could +you could do that right you open the top + + align:start position:0% +you could do that right you open the top + + + align:start position:0% +you could do that right you open the top +you stick it in you carefully stick it + + align:start position:0% +you stick it in you carefully stick it + + + align:start position:0% +you stick it in you carefully stick it +in if you could see it lots of times you + + align:start position:0% +in if you could see it lots of times you + + + align:start position:0% +in if you could see it lots of times you +can see these lipids because they're + + align:start position:0% +can see these lipids because they're + + + align:start position:0% +can see these lipids because they're +they're like opaque or something so you + + align:start position:0% +they're like opaque or something so you + + + align:start position:0% +they're like opaque or something so you +can see or if you have if you have still + + align:start position:0% +can see or if you have if you have still + + + align:start position:0% +can see or if you have if you have still +have your sucrose layers lots of times + + align:start position:0% +have your sucrose layers lots of times + + + align:start position:0% +have your sucrose layers lots of times +they layer in between the different + + align:start position:0% +they layer in between the different + + + align:start position:0% +they layer in between the different +concentrations of the sucrose and you + + align:start position:0% +concentrations of the sucrose and you + + + align:start position:0% +concentrations of the sucrose and you +see white stuff precipitating so you + + align:start position:0% +see white stuff precipitating so you + + + align:start position:0% +see white stuff precipitating so you +could conceivably stick a pipette from + + align:start position:0% +could conceivably stick a pipette from + + + align:start position:0% +could conceivably stick a pipette from +the top and suck it out okay absolutely + + align:start position:0% +the top and suck it out okay absolutely + + + align:start position:0% +the top and suck it out okay absolutely +with your term all together layers so + + align:start position:0% +with your term all together layers so + + + align:start position:0% +with your term all together layers so +here you doing doing something it's + + align:start position:0% +here you doing doing something it's + + + align:start position:0% +here you doing doing something it's +already a very hard experiment because + + align:start position:0% +already a very hard experiment because + + + align:start position:0% +already a very hard experiment because +they're all being perturbed anyhow + + align:start position:0% +they're all being perturbed anyhow + + + align:start position:0% +they're all being perturbed anyhow +because of diffusion so is there any + + align:start position:0% +because of diffusion so is there any + + + align:start position:0% +because of diffusion so is there any +other way you could think about + + align:start position:0% +other way you could think about + + + align:start position:0% +other way you could think about +separating these things and so the hint + + align:start position:0% +separating these things and so the hint + + + align:start position:0% +separating these things and so the hint +is that they use plastic tubes so these + + align:start position:0% +is that they use plastic tubes so these + + + align:start position:0% +is that they use plastic tubes so these +things are not glass you know no + + align:start position:0% +things are not glass you know no + + + align:start position:0% +things are not glass you know no +centrifuges well I mean oh so you don't + + align:start position:0% +centrifuges well I mean oh so you don't + + + align:start position:0% +centrifuges well I mean oh so you don't +do that that could be yeah okay so you + + align:start position:0% +do that that could be yeah okay so you + + + align:start position:0% +do that that could be yeah okay so you +could but then in that but you then have + + align:start position:0% +could but then in that but you then have + + + align:start position:0% +could but then in that but you then have +to if you were cutting it you felt to + + align:start position:0% +to if you were cutting it you felt to + + + align:start position:0% +to if you were cutting it you felt to +get it out of the tube right okay unless + + align:start position:0% +get it out of the tube right okay unless + + + align:start position:0% +get it out of the tube right okay unless +you had a saw that didn't have any + + align:start position:0% +you had a saw that didn't have any + + + align:start position:0% +you had a saw that didn't have any +vibrations when you were cutting it of + + align:start position:0% +vibrations when you were cutting it of + + + align:start position:0% +vibrations when you were cutting it of +course which would not happen + + align:start position:0% +course which would not happen + + + align:start position:0% +course which would not happen +okay but if you look here in this cut in + + align:start position:0% +okay but if you look here in this cut in + + + align:start position:0% +okay but if you look here in this cut in +this cartoon so I gave you this what are + + align:start position:0% +this cartoon so I gave you this what are + + + align:start position:0% +this cartoon so I gave you this what are +they doing here this sticking a syringe + + align:start position:0% +they doing here this sticking a syringe + + + align:start position:0% +they doing here this sticking a syringe +in through the side of the tube and + + align:start position:0% +in through the side of the tube and + + + align:start position:0% +in through the side of the tube and +that's still what people use so you can + + align:start position:0% +that's still what people use so you can + + + align:start position:0% +that's still what people use so you can +suck out if you can see something you + + align:start position:0% +suck out if you can see something you + + + align:start position:0% +suck out if you can see something you +know so you have to be able to see in + + align:start position:0% +know so you have to be able to see in + + + align:start position:0% +know so you have to be able to see in +some way to know where to suck it out so + + align:start position:0% +some way to know where to suck it out so + + + align:start position:0% +some way to know where to suck it out so +you might have a way actually in doing + + align:start position:0% +you might have a way actually in doing + + + align:start position:0% +you might have a way actually in doing +ultracentrifugation I think with the + + align:start position:0% +ultracentrifugation I think with the + + + align:start position:0% +ultracentrifugation I think with the +lipids you can see them by eyeball but + + align:start position:0% +lipids you can see them by eyeball but + + + align:start position:0% +lipids you can see them by eyeball but +you might look at absorption if you if + + align:start position:0% +you might look at absorption if you if + + + align:start position:0% +you might look at absorption if you if +they have proteins you could monitor + + align:start position:0% +they have proteins you could monitor + + + align:start position:0% +they have proteins you could monitor +absorption through the gradient and that + + align:start position:0% +absorption through the gradient and that + + + align:start position:0% +absorption through the gradient and that +might tell you how to fractionate things + + align:start position:0% +might tell you how to fractionate things + + + align:start position:0% +might tell you how to fractionate things +but anyhow that's also an issue because + + align:start position:0% +but anyhow that's also an issue because + + + align:start position:0% +but anyhow that's also an issue because +before they can do the next step in the + + align:start position:0% +before they can do the next step in the + + + align:start position:0% +before they can do the next step in the +analysis they've got to get the material + + align:start position:0% +analysis they've got to get the material + + + align:start position:0% +analysis they've got to get the material +out okay so they've got the material out + + align:start position:0% +out okay so they've got the material out + + + align:start position:0% +out okay so they've got the material out +in each of these steps and then how do + + align:start position:0% +in each of these steps and then how do + + + align:start position:0% +in each of these steps and then how do +they look at this they get thick and + + align:start position:0% +they look at this they get thick and + + + align:start position:0% +they look at this they get thick and +pull it out + + align:start position:0% +pull it out + + + align:start position:0% +pull it out +so what are they looking for to tell + + align:start position:0% +so what are they looking for to tell + + + align:start position:0% +so what are they looking for to tell +them how effective this method is right + + align:start position:0% +them how effective this method is right + + + align:start position:0% +them how effective this method is right +it's at exactly so what are they so to + + align:start position:0% +it's at exactly so what are they so to + + + align:start position:0% +it's at exactly so what are they so to +do that what they're gonna have to do is + + align:start position:0% +do that what they're gonna have to do is + + + align:start position:0% +do that what they're gonna have to do is +we're going to before we look at the + + align:start position:0% +we're going to before we look at the + + + align:start position:0% +we're going to before we look at the +details of the method I want to go + + align:start position:0% +details of the method I want to go + + + align:start position:0% +details of the method I want to go +through a Western blot okay yeah so what + + align:start position:0% +through a Western blot okay yeah so what + + + align:start position:0% +through a Western blot okay yeah so what +do we know about a Western blot yeah yep + + align:start position:0% +do we know about a Western blot yeah yep + + + align:start position:0% +do we know about a Western blot yeah yep +about the which method yeah yeah yeah + + align:start position:0% +about the which method yeah yeah yeah + + + align:start position:0% +about the which method yeah yeah yeah +you could do that yeah I mean there's a + + align:start position:0% +you could do that yeah I mean there's a + + + align:start position:0% +you could do that yeah I mean there's a +lot of ways to crack up themselves I + + align:start position:0% +lot of ways to crack up themselves I + + + align:start position:0% +lot of ways to crack up themselves I +don't know which one's the best + + align:start position:0% +don't know which one's the best + + + align:start position:0% +don't know which one's the best +mammalian cells are really easy to open + + align:start position:0% +mammalian cells are really easy to open + + + align:start position:0% +mammalian cells are really easy to open +sometimes I like to do is freeze and + + align:start position:0% +sometimes I like to do is freeze and + + + align:start position:0% +sometimes I like to do is freeze and +thaw them sometimes you have like a + + align:start position:0% +thaw them sometimes you have like a + + + align:start position:0% +thaw them sometimes you have like a +little just a mortar and pestle or + + align:start position:0% +little just a mortar and pestle or + + + align:start position:0% +little just a mortar and pestle or +something like that but that's that it + + align:start position:0% +something like that but that's that it + + + align:start position:0% +something like that but that's that it +mean yeast cells you you roll them + + align:start position:0% +mean yeast cells you you roll them + + + align:start position:0% +mean yeast cells you you roll them +yep them enough cells so you can do + + align:start position:0% +yep them enough cells so you can do + + + align:start position:0% +yep them enough cells so you can do +something if you only have a tiny amount + + align:start position:0% +something if you only have a tiny amount + + + align:start position:0% +something if you only have a tiny amount +of cells it makes it really challenging + + align:start position:0% +of cells it makes it really challenging + + + align:start position:0% +of cells it makes it really challenging +with beads because it covers the beads + + align:start position:0% +with beads because it covers the beads + + + align:start position:0% +with beads because it covers the beads +see sticking to that absolutely I'm sure + + align:start position:0% +see sticking to that absolutely I'm sure + + + align:start position:0% +see sticking to that absolutely I'm sure +you have to look at all of that kind of + + align:start position:0% +you have to look at all of that kind of + + + align:start position:0% +you have to look at all of that kind of +stuff so how you choose that's an + + align:start position:0% +stuff so how you choose that's an + + + align:start position:0% +stuff so how you choose that's an +important thing to look at how you + + align:start position:0% +important thing to look at how you + + + align:start position:0% +important thing to look at how you +choose to crack open the cells and I + + align:start position:0% +choose to crack open the cells and I + + + align:start position:0% +choose to crack open the cells and I +mean it's the same with bacterial cells + + align:start position:0% +mean it's the same with bacterial cells + + + align:start position:0% +mean it's the same with bacterial cells +there there are three four ways to crack + + align:start position:0% +there there are three four ways to crack + + + align:start position:0% +there there are three four ways to crack +open the cells and I can tell you only + + align:start position:0% +open the cells and I can tell you only + + + align:start position:0% +open the cells and I can tell you only +one of them really works efficiently and + + align:start position:0% +one of them really works efficiently and + + + align:start position:0% +one of them really works efficiently and +a lot of people when they use some of + + align:start position:0% +a lot of people when they use some of + + + align:start position:0% +a lot of people when they use some of +the others you know they do something + + align:start position:0% +the others you know they do something + + + align:start position:0% +the others you know they do something +and they assume it works but they never + + align:start position:0% +and they assume it works but they never + + + align:start position:0% +and they assume it works but they never +check to see whether the cell walls have + + align:start position:0% +check to see whether the cell walls have + + + align:start position:0% +check to see whether the cell walls have +been cracked open a lot of times they + + align:start position:0% +been cracked open a lot of times they + + + align:start position:0% +been cracked open a lot of times they +haven't and so what you get out is very + + align:start position:0% +haven't and so what you get out is very + + + align:start position:0% +haven't and so what you get out is very +very low levels of protein because you + + align:start position:0% +very low levels of protein because you + + + align:start position:0% +very low levels of protein because you +haven't cracked open the cells so + + align:start position:0% +haven't cracked open the cells so + + + align:start position:0% +haven't cracked open the cells so +figuring out I mean mammalian cells are + + align:start position:0% +figuring out I mean mammalian cells are + + + align:start position:0% +figuring out I mean mammalian cells are +apparently I don't work with those + + align:start position:0% +apparently I don't work with those + + + align:start position:0% +apparently I don't work with those +myself but they're apparently much + + align:start position:0% +myself but they're apparently much + + + align:start position:0% +myself but they're apparently much +easier to disrupt than bacteria or you + + align:start position:0% +easier to disrupt than bacteria or you + + + align:start position:0% +easier to disrupt than bacteria or you +know if you look at fungi a fungi are + + align:start position:0% +know if you look at fungi a fungi are + + + align:start position:0% +know if you look at fungi a fungi are +really hard to crack crack open Easter + + align:start position:0% +really hard to crack crack open Easter + + + align:start position:0% +really hard to crack crack open Easter +so anyhow that's that's an important + + align:start position:0% +so anyhow that's that's an important + + + align:start position:0% +so anyhow that's that's an important +thing to look at so every one of these + + align:start position:0% +thing to look at so every one of these + + + align:start position:0% +thing to look at so every one of these +things I mean it again may be the devil + + align:start position:0% +things I mean it again may be the devil + + + align:start position:0% +things I mean it again may be the devil +the devil is in the detail + + align:start position:0% +the devil is in the detail + + + align:start position:0% +the devil is in the detail +but when you're doing your own research + + align:start position:0% +but when you're doing your own research + + + align:start position:0% +but when you're doing your own research +it doesn't matter what method you you're + + align:start position:0% +it doesn't matter what method you you're + + + align:start position:0% +it doesn't matter what method you you're +looking at the first time around you + + align:start position:0% +looking at the first time around you + + + align:start position:0% +looking at the first time around you +need to look at it in detail and + + align:start position:0% +need to look at it in detail and + + + align:start position:0% +need to look at it in detail and +convince yourself that this is a good + + align:start position:0% +convince yourself that this is a good + + + align:start position:0% +convince yourself that this is a good +way to chase this down and you look at + + align:start position:0% +way to chase this down and you look at + + + align:start position:0% +way to chase this down and you look at +it in detail the first time around and + + align:start position:0% +it in detail the first time around and + + + align:start position:0% +it in detail the first time around and +when you convince yourself it's working + + align:start position:0% +when you convince yourself it's working + + + align:start position:0% +when you convince yourself it's working +really well in doing what you want to do + + align:start position:0% +really well in doing what you want to do + + + align:start position:0% +really well in doing what you want to do +then you you just use it now that's the + + align:start position:0% +then you you just use it now that's the + + + align:start position:0% +then you you just use it now that's the +end of it you don't have to go back and + + align:start position:0% +end of it you don't have to go back and + + + align:start position:0% +end of it you don't have to go back and +keep thinking about this over and over + + align:start position:0% +keep thinking about this over and over + + + align:start position:0% +keep thinking about this over and over +again but so the method we're going to + + align:start position:0% +again but so the method we're going to + + + align:start position:0% +again but so the method we're going to +use is a Western blot okay so we got + + align:start position:0% +use is a Western blot okay so we got + + + align:start position:0% +use is a Western blot okay so we got +this stuff out and have you all have you + + align:start position:0% +this stuff out and have you all have you + + + align:start position:0% +this stuff out and have you all have you +all run sds-page shells + + align:start position:0% +all run sds-page shells + + + align:start position:0% +all run sds-page shells +okay so sds-page gels separate proteins + + align:start position:0% +okay so sds-page gels separate proteins + + + align:start position:0% +okay so sds-page gels separate proteins +how by the what not charge right but + + align:start position:0% +how by the what not charge right but + + + align:start position:0% +how by the what not charge right but +they but yeah it's based on size because + + align:start position:0% +they but yeah it's based on size because + + + align:start position:0% +they but yeah it's based on size because +it's coated with every protein ratio is + + align:start position:0% +it's coated with every protein ratio is + + + align:start position:0% +it's coated with every protein ratio is +coated with this detergent sodium + + align:start position:0% +coated with this detergent sodium + + + align:start position:0% +coated with this detergent sodium +dodecyl sulfate which makes them migrate + + align:start position:0% +dodecyl sulfate which makes them migrate + + + align:start position:0% +dodecyl sulfate which makes them migrate +pretty much like the molecular weight + + align:start position:0% +pretty much like the molecular weight + + + align:start position:0% +pretty much like the molecular weight +but if you've done these it's not + + align:start position:0% +but if you've done these it's not + + + align:start position:0% +but if you've done these it's not +exactly like the molecular weight you + + align:start position:0% +exactly like the molecular weight you + + + align:start position:0% +exactly like the molecular weight you +can do standards where you know the + + align:start position:0% +can do standards where you know the + + + align:start position:0% +can do standards where you know the +molecular weight you can do a standard + + align:start position:0% +molecular weight you can do a standard + + + align:start position:0% +molecular weight you can do a standard +curve and then you see where your + + align:start position:0% +curve and then you see where your + + + align:start position:0% +curve and then you see where your +protein migrates and sometimes say + + align:start position:0% +protein migrates and sometimes say + + + align:start position:0% +protein migrates and sometimes say +migrate a little faster sometimes a + + align:start position:0% +migrate a little faster sometimes a + + + align:start position:0% +migrate a little faster sometimes a +little slower but it's it's okay so you + + align:start position:0% +little slower but it's it's okay so you + + + align:start position:0% +little slower but it's it's okay so you +you run this and then what do you do + + align:start position:0% +you run this and then what do you do + + + align:start position:0% +you run this and then what do you do +does anybody know what you do next to do + + align:start position:0% +does anybody know what you do next to do + + + align:start position:0% +does anybody know what you do next to do +a Western + + align:start position:0% + + + + align:start position:0% + +right so the next thing they did was + + align:start position:0% +right so the next thing they did was + + + align:start position:0% +right so the next thing they did was +they used whoops I'm going to put all of + + align:start position:0% +they used whoops I'm going to put all of + + + align:start position:0% +they used whoops I'm going to put all of +these up so they transferred it to a + + align:start position:0% +these up so they transferred it to a + + + align:start position:0% +these up so they transferred it to a +membrane okay and why did they have to + + align:start position:0% +membrane okay and why did they have to + + + align:start position:0% +membrane okay and why did they have to +transfer it into a membrane to do this + + align:start position:0% +transfer it into a membrane to do this + + + align:start position:0% +transfer it into a membrane to do this +analysis and this is an extra step and + + align:start position:0% +analysis and this is an extra step and + + + align:start position:0% +analysis and this is an extra step and +it turns out so you know we're gonna + + align:start position:0% +it turns out so you know we're gonna + + + align:start position:0% +it turns out so you know we're gonna +look at an antibody interacting with a + + align:start position:0% +look at an antibody interacting with a + + + align:start position:0% +look at an antibody interacting with a +protein why don't we just look at the + + align:start position:0% +protein why don't we just look at the + + + align:start position:0% +protein why don't we just look at the +antibody interacting where the protein + + align:start position:0% +antibody interacting where the protein + + + align:start position:0% +antibody interacting where the protein +to start with right it doesn't have very + + align:start position:0% +to start with right it doesn't have very + + + align:start position:0% +to start with right it doesn't have very +good access it's really not very + + align:start position:0% +good access it's really not very + + + align:start position:0% +good access it's really not very +efficient so people found pretty much by + + align:start position:0% +efficient so people found pretty much by + + + align:start position:0% +efficient so people found pretty much by +trial and error that you needed to + + align:start position:0% +trial and error that you needed to + + + align:start position:0% +trial and error that you needed to +transfer this to a membrane I mean we + + align:start position:0% +transfer this to a membrane I mean we + + + align:start position:0% +transfer this to a membrane I mean we +have hundreds of kinds of membranes how + + align:start position:0% +have hundreds of kinds of membranes how + + + align:start position:0% +have hundreds of kinds of membranes how +do they choose nitrocellulose okay is if + + align:start position:0% +do they choose nitrocellulose okay is if + + + align:start position:0% +do they choose nitrocellulose okay is if +any of you have want run westerns you + + align:start position:0% +any of you have want run westerns you + + + align:start position:0% +any of you have want run westerns you +know remember what kind of a membrane + + align:start position:0% +know remember what kind of a membrane + + + align:start position:0% +know remember what kind of a membrane +you used did you use nitrocellulose they + + align:start position:0% +you used did you use nitrocellulose they + + + align:start position:0% +you used did you use nitrocellulose they +you do this an undergraduate class don't + + align:start position:0% +you do this an undergraduate class don't + + + align:start position:0% +you do this an undergraduate class don't +you don't you you don't do a Western + + align:start position:0% +you don't you you don't do a Western + + + align:start position:0% +you don't you you don't do a Western +okay we used to do yeah in what kind of + + align:start position:0% +okay we used to do yeah in what kind of + + + align:start position:0% +okay we used to do yeah in what kind of +a membrane was it in biology okay so + + align:start position:0% +a membrane was it in biology okay so + + + align:start position:0% +a membrane was it in biology okay so +what remember you remember what the + + align:start position:0% +what remember you remember what the + + + align:start position:0% +what remember you remember what the +membrane was yeah it's not nature + + align:start position:0% +membrane was yeah it's not nature + + + align:start position:0% +membrane was yeah it's not nature +cellulose oh this PVDF polyvinyl + + align:start position:0% +cellulose oh this PVDF polyvinyl + + + align:start position:0% +cellulose oh this PVDF polyvinyl +difluoride is the standard one that + + align:start position:0% +difluoride is the standard one that + + + align:start position:0% +difluoride is the standard one that +people use now it works much better than + + align:start position:0% +people use now it works much better than + + + align:start position:0% +people use now it works much better than +nitro cellulous this paper is really old + + align:start position:0% +nitro cellulous this paper is really old + + + align:start position:0% +nitro cellulous this paper is really old +and so they're looking at nitro + + align:start position:0% +and so they're looking at nitro + + + align:start position:0% +and so they're looking at nitro +cellulous okay so then they they do this + + align:start position:0% +cellulous okay so then they they do this + + + align:start position:0% +cellulous okay so then they they do this +okay and then what do they do next they + + align:start position:0% +okay and then what do they do next they + + + align:start position:0% +okay and then what do they do next they +have an antibody we'll look at the + + align:start position:0% +have an antibody we'll look at the + + + align:start position:0% +have an antibody we'll look at the +details of this in a minute that can + + align:start position:0% +details of this in a minute that can + + + align:start position:0% +details of this in a minute that can +recognize the protein that can find it + + align:start position:0% +recognize the protein that can find it + + + align:start position:0% +recognize the protein that can find it +on the membrane okay and then what we're + + align:start position:0% +on the membrane okay and then what we're + + + align:start position:0% +on the membrane okay and then what we're +gonna see is you still can't see + + align:start position:0% +gonna see is you still can't see + + + align:start position:0% +gonna see is you still can't see +anything really because you don't have + + align:start position:0% +anything really because you don't have + + + align:start position:0% +anything really because you don't have +very much material there and you can't + + align:start position:0% +very much material there and you can't + + + align:start position:0% +very much material there and you can't +observer you don't have enough to stain + + align:start position:0% +observer you don't have enough to stain + + + align:start position:0% +observer you don't have enough to stain +off and house by Kumasi so you're gonna + + align:start position:0% +off and house by Kumasi so you're gonna + + + align:start position:0% +off and house by Kumasi so you're gonna +have to implement so then you're gonna + + align:start position:0% +have to implement so then you're gonna + + + align:start position:0% +have to implement so then you're gonna +make an antibody to an antibody and then + + align:start position:0% +make an antibody to an antibody and then + + + align:start position:0% +make an antibody to an antibody and then +you have to figure out how to then + + align:start position:0% +you have to figure out how to then + + + align:start position:0% +you have to figure out how to then +amplify the signal and we'll look at + + align:start position:0% +amplify the signal and we'll look at + + + align:start position:0% +amplify the signal and we'll look at +that in a second is this what you ran a + + align:start position:0% +that in a second is this what you ran a + + + align:start position:0% +that in a second is this what you ran a +Western is this what westerns look like + + align:start position:0% + + + + align:start position:0% + +yeah so that's good you have to block + + align:start position:0% +yeah so that's good you have to block + + + align:start position:0% +yeah so that's good you have to block +everything if you're using crude extract + + align:start position:0% +everything if you're using crude extract + + + align:start position:0% +everything if you're using crude extract +okay so in this case we would be using + + align:start position:0% +okay so in this case we would be using + + + align:start position:0% +okay so in this case we would be using +the crude mixture well not a crude + + align:start position:0% +the crude mixture well not a crude + + + align:start position:0% +the crude mixture well not a crude +mixture it's been fractionated by the + + align:start position:0% +mixture it's been fractionated by the + + + align:start position:0% +mixture it's been fractionated by the +ultracentrifugation it's been + + align:start position:0% +ultracentrifugation it's been + + + align:start position:0% +ultracentrifugation it's been +fractionated but you still have mixtures + + align:start position:0% +fractionated but you still have mixtures + + + align:start position:0% +fractionated but you still have mixtures +of proteins in there have any of you + + align:start position:0% +of proteins in there have any of you + + + align:start position:0% +of proteins in there have any of you +ever looked at westerns in a paper + + align:start position:0% +ever looked at westerns in a paper + + + align:start position:0% +ever looked at westerns in a paper +well even the papers you had to read the + + align:start position:0% +well even the papers you had to read the + + + align:start position:0% +well even the papers you had to read the +paper on the PC go back and look at the + + align:start position:0% +paper on the PC go back and look at the + + + align:start position:0% +paper on the PC go back and look at the +P CK pcsk9 paper that had westerns in it + + align:start position:0% +P CK pcsk9 paper that had westerns in it + + + align:start position:0% +P CK pcsk9 paper that had westerns in it +what do you see do people show you + + align:start position:0% + + + + align:start position:0% + +something that looks like this and if + + align:start position:0% +something that looks like this and if + + + align:start position:0% +something that looks like this and if +they did show you that what would it + + align:start position:0% +they did show you that what would it + + + align:start position:0% +they did show you that what would it +look like so you have an antibody that's + + align:start position:0% +look like so you have an antibody that's + + + align:start position:0% +look like so you have an antibody that's +specific for the protein of interest + + align:start position:0% +specific for the protein of interest + + + align:start position:0% +specific for the protein of interest +whatever that is supposedly specific + + align:start position:0% +whatever that is supposedly specific + + + align:start position:0% +whatever that is supposedly specific +what do you see what do you think you + + align:start position:0% +what do you see what do you think you + + + align:start position:0% +what do you see what do you think you +see do you think antibodies are specific + + align:start position:0% +see do you think antibodies are specific + + + align:start position:0% +see do you think antibodies are specific +I think I have an example of a typical + + align:start position:0% +I think I have an example of a typical + + + align:start position:0% +I think I have an example of a typical +Western yeah yeah so when you look at + + align:start position:0% +Western yeah yeah so when you look at + + + align:start position:0% +Western yeah yeah so when you look at +when you look at a paper you should go + + align:start position:0% +when you look at a paper you should go + + + align:start position:0% +when you look at a paper you should go +back you should pay attention to this + + align:start position:0% +back you should pay attention to this + + + align:start position:0% +back you should pay attention to this +when you read a paper if you're doing + + align:start position:0% +when you read a paper if you're doing + + + align:start position:0% +when you read a paper if you're doing +anything in biology what do you see you + + align:start position:0% +anything in biology what do you see you + + + align:start position:0% +anything in biology what do you see you +never see a gel ever what you see is a + + align:start position:0% +never see a gel ever what you see is a + + + align:start position:0% +never see a gel ever what you see is a +slice of a gel where they cut off this + + align:start position:0% +slice of a gel where they cut off this + + + align:start position:0% +slice of a gel where they cut off this +whole way to they cut up all this stuff + + align:start position:0% +whole way to they cut up all this stuff + + + align:start position:0% +whole way to they cut up all this stuff +and all this stuff the reason they do + + align:start position:0% +and all this stuff the reason they do + + + align:start position:0% +and all this stuff the reason they do +that is because it's a hell of a mess + + align:start position:0% +that is because it's a hell of a mess + + + align:start position:0% +that is because it's a hell of a mess +okay so let me just show you we're + + align:start position:0% +okay so let me just show you we're + + + align:start position:0% +okay so let me just show you we're +typical I mean I don't care what kind of + + align:start position:0% +typical I mean I don't care what kind of + + + align:start position:0% +typical I mean I don't care what kind of +a antibody you're using in crude + + align:start position:0% +a antibody you're using in crude + + + align:start position:0% +a antibody you're using in crude +extracts it's a mess because you have + + align:start position:0% +extracts it's a mess because you have + + + align:start position:0% +extracts it's a mess because you have +nonspecific interactions well just look + + align:start position:0% +nonspecific interactions well just look + + + align:start position:0% +nonspecific interactions well just look +at that so that would be something like + + align:start position:0% +at that so that would be something like + + + align:start position:0% +at that so that would be something like +you might see depending on how much + + align:start position:0% +you might see depending on how much + + + align:start position:0% +you might see depending on how much +antibody you have so when you see this + + align:start position:0% +antibody you have so when you see this + + + align:start position:0% +antibody you have so when you see this +the reason everybody reports data like + + align:start position:0% +the reason everybody reports data like + + + align:start position:0% +the reason everybody reports data like +that now so it looks like it's really + + align:start position:0% +that now so it looks like it's really + + + align:start position:0% +that now so it looks like it's really +clean but in reality I think if it's + + align:start position:0% +clean but in reality I think if it's + + + align:start position:0% +clean but in reality I think if it's +dirty of that then in my opinion I would + + align:start position:0% +dirty of that then in my opinion I would + + + align:start position:0% +dirty of that then in my opinion I would +make you publish the whole gel but + + align:start position:0% +make you publish the whole gel but + + + align:start position:0% +make you publish the whole gel but +people want to do that they just + + align:start position:0% +people want to do that they just + + + align:start position:0% +people want to do that they just +cut off the little band they're + + align:start position:0% +cut off the little band they're + + + align:start position:0% +cut off the little band they're +interested in they can see it changed in + + align:start position:0% +interested in they can see it changed in + + + align:start position:0% +interested in they can see it changed in +concentration using this method but you + + align:start position:0% +concentration using this method but you + + + align:start position:0% +concentration using this method but you +should be aware of the fact that + + align:start position:0% +should be aware of the fact that + + + align:start position:0% +should be aware of the fact that +antibodies in general or specific as you + + align:start position:0% +antibodies in general or specific as you + + + align:start position:0% +antibodies in general or specific as you +think they're gonna be yeah well I mean + + align:start position:0% +think they're gonna be yeah well I mean + + + align:start position:0% +think they're gonna be yeah well I mean +I think you know probably depends on the + + align:start position:0% +I think you know probably depends on the + + + align:start position:0% +I think you know probably depends on the +journal and it probably depends on the + + align:start position:0% +journal and it probably depends on the + + + align:start position:0% +journal and it probably depends on the +reviewer but I would say we're going + + align:start position:0% +reviewer but I would say we're going + + + align:start position:0% +reviewer but I would say we're going +away from data this is something that is + + align:start position:0% +away from data this is something that is + + + align:start position:0% +away from data this is something that is +a pet peeve for me we don't and all the + + align:start position:0% +a pet peeve for me we don't and all the + + + align:start position:0% +a pet peeve for me we don't and all the +data which i think is alright is + + align:start position:0% +data which i think is alright is + + + align:start position:0% +data which i think is alright is +published and supplementary information + + align:start position:0% +published and supplementary information + + + align:start position:0% +published and supplementary information +as opposed to a paper I think if you + + align:start position:0% +as opposed to a paper I think if you + + + align:start position:0% +as opposed to a paper I think if you +have something really dirty you should + + align:start position:0% +have something really dirty you should + + + align:start position:0% +have something really dirty you should +publish in the paper in the main body of + + align:start position:0% +publish in the paper in the main body of + + + align:start position:0% +publish in the paper in the main body of +the paper do something that's really + + align:start position:0% +the paper do something that's really + + + align:start position:0% +the paper do something that's really +clean and it looks like that it's fine + + align:start position:0% +clean and it looks like that it's fine + + + align:start position:0% +clean and it looks like that it's fine +with me you don't even have to publish + + align:start position:0% +with me you don't even have to publish + + + align:start position:0% +with me you don't even have to publish +it if you could believe what people were + + align:start position:0% +it if you could believe what people were + + + align:start position:0% +it if you could believe what people were +saying okay because people know what + + align:start position:0% +saying okay because people know what + + + align:start position:0% +saying okay because people know what +this looks like a lot of people + + align:start position:0% +this looks like a lot of people + + + align:start position:0% +this looks like a lot of people +everybody uses westerns but if it's a + + align:start position:0% +everybody uses westerns but if it's a + + + align:start position:0% +everybody uses westerns but if it's a +real mess then you need to let your + + align:start position:0% +real mess then you need to let your + + + align:start position:0% +real mess then you need to let your +reader know that this is not such an + + align:start position:0% +reader know that this is not such an + + + align:start position:0% +reader know that this is not such an +easy experiment and it's not so + + align:start position:0% +easy experiment and it's not so + + + align:start position:0% +easy experiment and it's not so +clear-cut that's what your objective is + + align:start position:0% +clear-cut that's what your objective is + + + align:start position:0% +clear-cut that's what your objective is +is to show people the data from which + + align:start position:0% +is to show people the data from which + + + align:start position:0% +is to show people the data from which +you drew your conclusions and then they + + align:start position:0% +you drew your conclusions and then they + + + align:start position:0% +you drew your conclusions and then they +can draw their own conclusions which may + + align:start position:0% +can draw their own conclusions which may + + + align:start position:0% +can draw their own conclusions which may +be different okay + + align:start position:0% +be different okay + + + align:start position:0% +be different okay +so let's look at the apparatus to do + + align:start position:0% +so let's look at the apparatus to do + + + align:start position:0% +so let's look at the apparatus to do +this okay so you know how do you get + + align:start position:0% +this okay so you know how do you get + + + align:start position:0% +this okay so you know how do you get +from here to here so you have a gel you + + align:start position:0% +from here to here so you have a gel you + + + align:start position:0% +from here to here so you have a gel you +run the gel a poly acrylamide gel what + + align:start position:0% +run the gel a poly acrylamide gel what + + + align:start position:0% +run the gel a poly acrylamide gel what +do you do so you put the membrane on the + + align:start position:0% +do you do so you put the membrane on the + + + align:start position:0% +do you do so you put the membrane on the +gel and what do you do + + align:start position:0% + + + + align:start position:0% + +okay yeah so you have to you're + + align:start position:0% +okay yeah so you have to you're + + + align:start position:0% +okay yeah so you have to you're +transferring it based on applying a + + align:start position:0% +transferring it based on applying a + + + align:start position:0% +transferring it based on applying a +voltage across this system so here's + + align:start position:0% +voltage across this system so here's + + + align:start position:0% +voltage across this system so here's +your gel okay and here's your membrane + + align:start position:0% +your gel okay and here's your membrane + + + align:start position:0% +your gel okay and here's your membrane +nitrocellulose membrane okay and then + + align:start position:0% +nitrocellulose membrane okay and then + + + align:start position:0% +nitrocellulose membrane okay and then +they have filter paper above and above + + align:start position:0% +they have filter paper above and above + + + align:start position:0% +they have filter paper above and above +the gel and below the membrane and why + + align:start position:0% +the gel and below the membrane and why + + + align:start position:0% +the gel and below the membrane and why +do you think they have the filter paper + + align:start position:0% +do you think they have the filter paper + + + align:start position:0% +do you think they have the filter paper +paper there did you when you were in the + + align:start position:0% +paper there did you when you were in the + + + align:start position:0% +paper there did you when you were in the +gel did you have filter paper yeah how + + align:start position:0% +gel did you have filter paper yeah how + + + align:start position:0% +gel did you have filter paper yeah how +do you think they decide how to do this + + align:start position:0% +do you think they decide how to do this + + + align:start position:0% +do you think they decide how to do this +transfer do you think this is + + align:start position:0% +transfer do you think this is + + + align:start position:0% +transfer do you think this is +straightforward you know do you run it + + align:start position:0% +straightforward you know do you run it + + + align:start position:0% +straightforward you know do you run it +for an hour do you run it for five hours + + align:start position:0% +for an hour do you run it for five hours + + + align:start position:0% +for an hour do you run it for five hours +do you run it for 15 minutes what is the + + align:start position:0% +do you run it for 15 minutes what is the + + + align:start position:0% +do you run it for 15 minutes what is the +voltage you use to do the transfer do + + align:start position:0% +voltage you use to do the transfer do + + + align:start position:0% +voltage you use to do the transfer do +you think any of that it's hard to + + align:start position:0% +you think any of that it's hard to + + + align:start position:0% +you think any of that it's hard to +figure out okay so how do you figure + + align:start position:0% +figure out okay so how do you figure + + + align:start position:0% +figure out okay so how do you figure +that out do you just somebody told you + + align:start position:0% +that out do you just somebody told you + + + align:start position:0% +that out do you just somebody told you +that this is a good way to do it + + align:start position:0% +that this is a good way to do it + + + align:start position:0% +that this is a good way to do it +yeah so that might be a place you start + + align:start position:0% +yeah so that might be a place you start + + + align:start position:0% +yeah so that might be a place you start +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so you do it because somebody gave you a + + align:start position:0% +so you do it because somebody gave you a + + + align:start position:0% +so you do it because somebody gave you a +recipe okay but then what do you need to + + align:start position:0% +recipe okay but then what do you need to + + + align:start position:0% +recipe okay but then what do you need to +do to make sure this recipe is correct + + align:start position:0% + + + + align:start position:0% + +right so and then how do you do that so + + align:start position:0% +right so and then how do you do that so + + + align:start position:0% +right so and then how do you do that so +that that's true every protein is gonna + + align:start position:0% +that that's true every protein is gonna + + + align:start position:0% +that that's true every protein is gonna +be different and if you have a protein + + align:start position:0% +be different and if you have a protein + + + align:start position:0% +be different and if you have a protein +if you have a clean protein versus a + + align:start position:0% +if you have a clean protein versus a + + + align:start position:0% +if you have a clean protein versus a +mess of proteins and you try to do this + + align:start position:0% +mess of proteins and you try to do this + + + align:start position:0% +mess of proteins and you try to do this +transfer the transfer conditions will be + + align:start position:0% +transfer the transfer conditions will be + + + align:start position:0% +transfer the transfer conditions will be +different so for example if you really + + align:start position:0% +different so for example if you really + + + align:start position:0% +different so for example if you really +want to look at the concentration of + + align:start position:0% +want to look at the concentration of + + + align:start position:0% +want to look at the concentration of +something inside the cell and the crude + + align:start position:0% +something inside the cell and the crude + + + align:start position:0% +something inside the cell and the crude +extracts you never compare it to a + + align:start position:0% +extracts you never compare it to a + + + align:start position:0% +extracts you never compare it to a +standard with clean protein because this + + align:start position:0% +standard with clean protein because this + + + align:start position:0% +standard with clean protein because this +transfer is different so you need in the + + align:start position:0% +transfer is different so you need in the + + + align:start position:0% +transfer is different so you need in the +back of your mind if you care about + + align:start position:0% +back of your mind if you care about + + + align:start position:0% +back of your mind if you care about +quantitating this you need to understand + + align:start position:0% +quantitating this you need to understand + + + align:start position:0% +quantitating this you need to understand +the basis of the transfer okay so why do + + align:start position:0% +the basis of the transfer okay so why do + + + align:start position:0% +the basis of the transfer okay so why do +you think they have these filter papers + + align:start position:0% +you think they have these filter papers + + + align:start position:0% +you think they have these filter papers +here so this goes back to what controls + + align:start position:0% +here so this goes back to what controls + + + align:start position:0% +here so this goes back to what controls +you you would do to see whether your + + align:start position:0% +you you would do to see whether your + + + align:start position:0% +you you would do to see whether your +transfer was working so what would you + + align:start position:0% +transfer was working so what would you + + + align:start position:0% +transfer was working so what would you +look for + + align:start position:0% + + + + align:start position:0% + +did you do this what did you do why do + + align:start position:0% +did you do this what did you do why do + + + align:start position:0% +did you do this what did you do why do +you have that what did you do with the + + align:start position:0% +you have that what did you do with the + + + align:start position:0% +you have that what did you do with the +filter papers in your you did what no no + + align:start position:0% +filter papers in your you did what no no + + + align:start position:0% +filter papers in your you did what no no +that's not what you do yeah I mean you + + align:start position:0% +that's not what you do yeah I mean you + + + align:start position:0% +that's not what you do yeah I mean you +might want to do some of that too but + + align:start position:0% +might want to do some of that too but + + + align:start position:0% +might want to do some of that too but +what is the bit in terms of thinking + + align:start position:0% +what is the bit in terms of thinking + + + align:start position:0% +what is the bit in terms of thinking +about whether your transfer is + + align:start position:0% +about whether your transfer is + + + align:start position:0% +about whether your transfer is +successful you know figuring out the + + align:start position:0% +successful you know figuring out the + + + align:start position:0% +successful you know figuring out the +conditions to blot from the gel to a + + align:start position:0% +conditions to blot from the gel to a + + + align:start position:0% +conditions to blot from the gel to a +piece of paper it's not trivial okay + + align:start position:0% +piece of paper it's not trivial okay + + + align:start position:0% +piece of paper it's not trivial okay +and so this there is a standard way that + + align:start position:0% +and so this there is a standard way that + + + align:start position:0% +and so this there is a standard way that +you do this initially to try but then + + align:start position:0% +you do this initially to try but then + + + align:start position:0% +you do this initially to try but then +you have to make sure that that method + + align:start position:0% +you have to make sure that that method + + + align:start position:0% +you have to make sure that that method +is working and lots of times it doesn't + + align:start position:0% +is working and lots of times it doesn't + + + align:start position:0% +is working and lots of times it doesn't +work so it's something that's going to + + align:start position:0% +work so it's something that's going to + + + align:start position:0% +work so it's something that's going to +be experimentally determined so the + + align:start position:0% +be experimentally determined so the + + + align:start position:0% +be experimentally determined so the +question is what happens if you did what + + align:start position:0% +question is what happens if you did what + + + align:start position:0% +question is what happens if you did what +would you think would happen if you do + + align:start position:0% +would you think would happen if you do + + + align:start position:0% +would you think would happen if you do +this for six or seven hours whereas a + + align:start position:0% +this for six or seven hours whereas a + + + align:start position:0% +this for six or seven hours whereas a +normal blot would take two hours right + + align:start position:0% +normal blot would take two hours right + + + align:start position:0% +normal blot would take two hours right +it would go right into the filter paper + + align:start position:0% +it would go right into the filter paper + + + align:start position:0% +it would go right into the filter paper +or even off the filter paper so what you + + align:start position:0% +or even off the filter paper so what you + + + align:start position:0% +or even off the filter paper so what you +do is you take the filter paper out you + + align:start position:0% +do is you take the filter paper out you + + + align:start position:0% +do is you take the filter paper out you +look for protein being found okay what + + align:start position:0% +look for protein being found okay what + + + align:start position:0% +look for protein being found okay what +about the gel what do you do with the + + align:start position:0% +about the gel what do you do with the + + + align:start position:0% +about the gel what do you do with the +gel after your experiments over + + align:start position:0% + + + + align:start position:0% + +right make sure that the proteins not on + + align:start position:0% +right make sure that the proteins not on + + + align:start position:0% +right make sure that the proteins not on +it so these are simple controls but + + align:start position:0% +it so these are simple controls but + + + align:start position:0% +it so these are simple controls but +these are the controls you always do + + align:start position:0% +these are the controls you always do + + + align:start position:0% +these are the controls you always do +until you work out the conditions to + + align:start position:0% +until you work out the conditions to + + + align:start position:0% +until you work out the conditions to +make sure this works and it's pretty + + align:start position:0% +make sure this works and it's pretty + + + align:start position:0% +make sure this works and it's pretty +critical to make sure you have good + + align:start position:0% +critical to make sure you have good + + + align:start position:0% +critical to make sure you have good +transfer so then if you look at the area + + align:start position:0% +transfer so then if you look at the area + + + align:start position:0% +transfer so then if you look at the area +so this is the antibody thing that they + + align:start position:0% +so this is the antibody thing that they + + + align:start position:0% +so this is the antibody thing that they +do is anybody thought about these kinds + + align:start position:0% +do is anybody thought about these kinds + + + align:start position:0% +do is anybody thought about these kinds +of assays you've seen them I think + + align:start position:0% +of assays you've seen them I think + + + align:start position:0% +of assays you've seen them I think +already in class but you have what's + + align:start position:0% +already in class but you have what's + + + align:start position:0% +already in class but you have what's +wrong with this picture the target + + align:start position:0% +wrong with this picture the target + + + align:start position:0% +wrong with this picture the target +protein what's wrong with this picture + + align:start position:0% +protein what's wrong with this picture + + + align:start position:0% +protein what's wrong with this picture +and the target so here's your + + align:start position:0% +and the target so here's your + + + align:start position:0% +and the target so here's your +nitrocellulose filter paper what's wrong + + align:start position:0% +nitrocellulose filter paper what's wrong + + + align:start position:0% +nitrocellulose filter paper what's wrong +with this / - should be unfolded yeah so + + align:start position:0% +with this / - should be unfolded yeah so + + + align:start position:0% +with this / - should be unfolded yeah so +you're doing SDS page it's unfolded so + + align:start position:0% +you're doing SDS page it's unfolded so + + + align:start position:0% +you're doing SDS page it's unfolded so +then we react it with an antibody + + align:start position:0% +then we react it with an antibody + + + align:start position:0% +then we react it with an antibody +presumably we have a good antibody but + + align:start position:0% +presumably we have a good antibody but + + + align:start position:0% +presumably we have a good antibody but +you've already learned in the first half + + align:start position:0% +you've already learned in the first half + + + align:start position:0% +you've already learned in the first half +of this course it having really good + + align:start position:0% +of this course it having really good + + + align:start position:0% +of this course it having really good +antibodies is not so trivial you can get + + align:start position:0% +antibodies is not so trivial you can get + + + align:start position:0% +antibodies is not so trivial you can get +them but most of the time they are not + + align:start position:0% +them but most of the time they are not + + + align:start position:0% +them but most of the time they are not +specific if you're looking at crude + + align:start position:0% +specific if you're looking at crude + + + align:start position:0% +specific if you're looking at crude +extracts they have little epitopes they + + align:start position:0% +extracts they have little epitopes they + + + align:start position:0% +extracts they have little epitopes they +recognize if you're using monoclonal + + align:start position:0% +recognize if you're using monoclonal + + + align:start position:0% +recognize if you're using monoclonal +that could be present and other proteins + + align:start position:0% +that could be present and other proteins + + + align:start position:0% +that could be present and other proteins +and so and furthermore that how do you + + align:start position:0% +and so and furthermore that how do you + + + align:start position:0% +and so and furthermore that how do you +how are you detecting something approach + + align:start position:0% +how are you detecting something approach + + + align:start position:0% +how are you detecting something approach +an antibody is a protein it has + + align:start position:0% +an antibody is a protein it has + + + align:start position:0% +an antibody is a protein it has +absorption at 280 again this is too low + + align:start position:0% +absorption at 280 again this is too low + + + align:start position:0% +absorption at 280 again this is too low +to see so putting an antibody on it is + + align:start position:0% +to see so putting an antibody on it is + + + align:start position:0% +to see so putting an antibody on it is +still going to be too low to detect so + + align:start position:0% +still going to be too low to detect so + + + align:start position:0% +still going to be too low to detect so +how do you detect your signal so have + + align:start position:0% +how do you detect your signal so have + + + align:start position:0% +how do you detect your signal so have +you done this so I'm surprised they + + align:start position:0% +you done this so I'm surprised they + + + align:start position:0% +you done this so I'm surprised they +don't do this in your introductory class + + align:start position:0% +don't do this in your introductory class + + + align:start position:0% +don't do this in your introductory class +they don't do westerns at all okay so + + align:start position:0% +they don't do westerns at all okay so + + + align:start position:0% +they don't do westerns at all okay so +what you're looking at is an antibody - + + align:start position:0% +what you're looking at is an antibody - + + + align:start position:0% +what you're looking at is an antibody - +an antibody okay so you put your + + align:start position:0% +an antibody okay so you put your + + + align:start position:0% +an antibody okay so you put your +antibody on that's specific for your + + align:start position:0% +antibody on that's specific for your + + + align:start position:0% +antibody on that's specific for your +protein and then you make an antibody + + align:start position:0% +protein and then you make an antibody + + + align:start position:0% +protein and then you make an antibody +and another organism that can + + align:start position:0% +and another organism that can + + + align:start position:0% +and another organism that can +specifically recognize antibodies in + + align:start position:0% +specifically recognize antibodies in + + + align:start position:0% +specifically recognize antibodies in +general okay so if this is to a mouse + + align:start position:0% +general okay so if this is to a mouse + + + align:start position:0% +general okay so if this is to a mouse +you make it in a go and and isolate that + + align:start position:0% +you make it in a go and and isolate that + + + align:start position:0% +you make it in a go and and isolate that +and then what you do is derivatives the + + align:start position:0% +and then what you do is derivatives the + + + align:start position:0% +and then what you do is derivatives the +second antibody with what a protein okay + + align:start position:0% +second antibody with what a protein okay + + + align:start position:0% +second antibody with what a protein okay +that can can function as a catalyst + + align:start position:0% + + + + align:start position:0% + +well did what what did you say well no I + + align:start position:0% +well did what what did you say well no I + + + align:start position:0% +well did what what did you say well no I +mean I don't know whether it's more + + align:start position:0% +mean I don't know whether it's more + + + align:start position:0% +mean I don't know whether it's more +expensive or not but yeah so you'd have + + align:start position:0% +expensive or not but yeah so you'd have + + + align:start position:0% +expensive or not but yeah so you'd have +to derivative guys every primary + + align:start position:0% +to derivative guys every primary + + + align:start position:0% +to derivative guys every primary +antibody and so this is sort of a + + align:start position:0% +antibody and so this is sort of a + + + align:start position:0% +antibody and so this is sort of a +standard procedure you couldn't + + align:start position:0% +standard procedure you couldn't + + + align:start position:0% +standard procedure you couldn't +derivatives the primary antibody so + + align:start position:0% +derivatives the primary antibody so + + + align:start position:0% +derivatives the primary antibody so +that's not a bad question + + align:start position:0% +that's not a bad question + + + align:start position:0% +that's not a bad question +and so what you're doing now you can buy + + align:start position:0% +and so what you're doing now you can buy + + + align:start position:0% +and so what you're doing now you can buy +these commercially you know so they have + + align:start position:0% +these commercially you know so they have + + + align:start position:0% +these commercially you know so they have +go rabbit rabbit + + align:start position:0% +go rabbit rabbit + + + align:start position:0% +go rabbit rabbit +mouse whatever antibodies and the key is + + align:start position:0% +mouse whatever antibodies and the key is + + + align:start position:0% +mouse whatever antibodies and the key is +the amplification of the signal and use + + align:start position:0% +the amplification of the signal and use + + + align:start position:0% +the amplification of the signal and use +enzymes to amplify the signal does + + align:start position:0% +enzymes to amplify the signal does + + + align:start position:0% +enzymes to amplify the signal does +anybody know what the enzymes are with + + align:start position:0% +anybody know what the enzymes are with + + + align:start position:0% +anybody know what the enzymes are with +the enzymes do to amplify the signal to + + align:start position:0% +the enzymes do to amplify the signal to + + + align:start position:0% +the enzymes do to amplify the signal to +something that's colored okay so does + + align:start position:0% +something that's colored okay so does + + + align:start position:0% +something that's colored okay so does +anybody know what that horseradish + + align:start position:0% +anybody know what that horseradish + + + align:start position:0% +anybody know what that horseradish +peroxidase have you ever heard of + + align:start position:0% +peroxidase have you ever heard of + + + align:start position:0% +peroxidase have you ever heard of +horseradish peroxidase so that's a heme + + align:start position:0% +horseradish peroxidase so that's a heme + + + align:start position:0% +horseradish peroxidase so that's a heme +iron we're gonna be talking about heme + + align:start position:0% +iron we're gonna be talking about heme + + + align:start position:0% +iron we're gonna be talking about heme +iron is pretty soon and hydrogen + + align:start position:0% +iron is pretty soon and hydrogen + + + align:start position:0% +iron is pretty soon and hydrogen +peroxide and makes our chemically very + + align:start position:0% +peroxide and makes our chemically very + + + align:start position:0% +peroxide and makes our chemically very +reactive iron oxide species that can + + align:start position:0% +reactive iron oxide species that can + + + align:start position:0% +reactive iron oxide species that can +oxidize a dye that changes color and it + + align:start position:0% +oxidize a dye that changes color and it + + + align:start position:0% +oxidize a dye that changes color and it +has an extremely high extinction + + align:start position:0% +has an extremely high extinction + + + align:start position:0% +has an extremely high extinction +coefficient so you can see it and it + + align:start position:0% +coefficient so you can see it and it + + + align:start position:0% +coefficient so you can see it and it +does the catalytically and the lifetime + + align:start position:0% +does the catalytically and the lifetime + + + align:start position:0% +does the catalytically and the lifetime +of the dye is long enough so it + + align:start position:0% +of the dye is long enough so it + + + align:start position:0% +of the dye is long enough so it +accumulates and you can get really + + align:start position:0% +accumulates and you can get really + + + align:start position:0% +accumulates and you can get really +amplification over your signal or you + + align:start position:0% +amplification over your signal or you + + + align:start position:0% +amplification over your signal or you +can use a phosphatase that liberate + + align:start position:0% +can use a phosphatase that liberate + + + align:start position:0% +can use a phosphatase that liberate +something that's highly colored again + + align:start position:0% +something that's highly colored again + + + align:start position:0% +something that's highly colored again +and you can see it so this is a standard + + align:start position:0% +and you can see it so this is a standard + + + align:start position:0% +and you can see it so this is a standard +method that everybody uses and so that's + + align:start position:0% +method that everybody uses and so that's + + + align:start position:0% +method that everybody uses and so that's +our gel so now we're looking at sort of + + align:start position:0% +our gel so now we're looking at sort of + + + align:start position:0% +our gel so now we're looking at sort of +we're at the end already but we're + + align:start position:0% +we're at the end already but we're + + + align:start position:0% +we're at the end already but we're +looking at these gels and what do you + + align:start position:0% +looking at these gels and what do you + + + align:start position:0% +looking at these gels and what do you +see through the different steps so if we + + align:start position:0% +see through the different steps so if we + + + align:start position:0% +see through the different steps so if we +look through the first gradient through + + align:start position:0% +look through the first gradient through + + + align:start position:0% +look through the first gradient through +the sucrose gradient that gets us + + align:start position:0% +the sucrose gradient that gets us + + + align:start position:0% +the sucrose gradient that gets us +through DNA okay and if you look say at + + align:start position:0% +through DNA okay and if you look say at + + + align:start position:0% +through DNA okay and if you look say at +Lane E and our goal is to separate + + align:start position:0% +Lane E and our goal is to separate + + + align:start position:0% +Lane E and our goal is to separate +proteins that are specifically localized + + align:start position:0% +proteins that are specifically localized + + + align:start position:0% +proteins that are specifically localized +in each one of these membranes so you + + align:start position:0% +in each one of these membranes so you + + + align:start position:0% +in each one of these membranes so you +need to believe that's true + + align:start position:0% +need to believe that's true + + + align:start position:0% +need to believe that's true +okay that people have selected the right + + align:start position:0% +okay that people have selected the right + + + align:start position:0% +okay that people have selected the right +group of proteins to look for and you + + align:start position:0% +group of proteins to look for and you + + + align:start position:0% +group of proteins to look for and you +notice they do more than one okay so + + align:start position:0% +notice they do more than one okay so + + + align:start position:0% +notice they do more than one okay so +they look at multiple proteins why do + + align:start position:0% +they look at multiple proteins why do + + + align:start position:0% +they look at multiple proteins why do +you think you need how do you think it's + + align:start position:0% +you think you need how do you think it's + + + align:start position:0% +you think you need how do you think it's +easy to select the proteins to look for + + align:start position:0% +easy to select the proteins to look for + + + align:start position:0% +easy to select the proteins to look for +and why or why not so I mean they + + align:start position:0% +and why or why not so I mean they + + + align:start position:0% +and why or why not so I mean they +obviously have selected a group of + + align:start position:0% +obviously have selected a group of + + + align:start position:0% +obviously have selected a group of +proteins and I think you know people + + align:start position:0% +proteins and I think you know people + + + align:start position:0% +proteins and I think you know people +most people would agree that they've + + align:start position:0% +most people would agree that they've + + + align:start position:0% +most people would agree that they've +selected a good group of proteins but + + align:start position:0% +selected a good group of proteins but + + + align:start position:0% +selected a good group of proteins but +what do we know now about proteins - + + align:start position:0% +what do we know now about proteins - + + + align:start position:0% +what do we know now about proteins - +they stay in one place you know they + + align:start position:0% +they stay in one place you know they + + + align:start position:0% +they stay in one place you know they +move around and so so but someone might + + align:start position:0% +move around and so so but someone might + + + align:start position:0% +move around and so so but someone might +be present and very low amount sometimes + + align:start position:0% +be present and very low amount sometimes + + + align:start position:0% +be present and very low amount sometimes +in much higher amounts and so you need + + align:start position:0% +in much higher amounts and so you need + + + align:start position:0% +in much higher amounts and so you need +to have more than one protein as a + + align:start position:0% +to have more than one protein as a + + + align:start position:0% +to have more than one protein as a +control to make sure you're looking at + + align:start position:0% +control to make sure you're looking at + + + align:start position:0% +control to make sure you're looking at +in the right region and what do you see + + align:start position:0% +in the right region and what do you see + + + align:start position:0% +in the right region and what do you see +in E if you look over here it tells you + + align:start position:0% +in E if you look over here it tells you + + + align:start position:0% +in E if you look over here it tells you +what the organelle is and if you look at + + align:start position:0% +what the organelle is and if you look at + + + align:start position:0% +what the organelle is and if you look at +this protein this is localized to the + + align:start position:0% +this protein this is localized to the + + + align:start position:0% +this protein this is localized to the +lysosomes we talked about that in class + + align:start position:0% +lysosomes we talked about that in class + + + align:start position:0% +lysosomes we talked about that in class +if you looked at this protein it's + + align:start position:0% +if you looked at this protein it's + + + align:start position:0% +if you looked at this protein it's +localized to the peroxisomes so in + + align:start position:0% +localized to the peroxisomes so in + + + align:start position:0% +localized to the peroxisomes so in +addition to the ones we care about the + + align:start position:0% +addition to the ones we care about the + + + align:start position:0% +addition to the ones we care about the +ER proteins we're also getting proteins + + align:start position:0% +ER proteins we're also getting proteins + + + align:start position:0% +ER proteins we're also getting proteins +that are localized in other membranes so + + align:start position:0% +that are localized in other membranes so + + + align:start position:0% +that are localized in other membranes so +that's when they went to the next to the + + align:start position:0% +that's when they went to the next to the + + + align:start position:0% +that's when they went to the next to the +next method and they added on another + + align:start position:0% +next method and they added on another + + + align:start position:0% +next method and they added on another +gradient to try to separate out again + + align:start position:0% +gradient to try to separate out again + + + align:start position:0% +gradient to try to separate out again +the lysosomal and the peroxisome old + + align:start position:0% +the lysosomal and the peroxisome old + + + align:start position:0% +the lysosomal and the peroxisome old +proteins and you can see they were + + align:start position:0% +proteins and you can see they were + + + align:start position:0% +proteins and you can see they were +pretty successful at this there's none + + align:start position:0% +pretty successful at this there's none + + + align:start position:0% +pretty successful at this there's none +of these proteins left in this gradient + + align:start position:0% +of these proteins left in this gradient + + + align:start position:0% +of these proteins left in this gradient +okay so that's that's good and they took + + align:start position:0% +okay so that's that's good and they took + + + align:start position:0% +okay so that's that's good and they took +it a step further do you remember what + + align:start position:0% +it a step further do you remember what + + + align:start position:0% +it a step further do you remember what +this is what are they looking for down + + align:start position:0% +this is what are they looking for down + + + align:start position:0% +this is what are they looking for down +here in this yeah so enzymatic + + align:start position:0% +here in this yeah so enzymatic + + + align:start position:0% +here in this yeah so enzymatic +activities are localized in certain + + align:start position:0% +activities are localized in certain + + + align:start position:0% +activities are localized in certain +organelle so they again did a second + + align:start position:0% +organelle so they again did a second + + + align:start position:0% +organelle so they again did a second +experiment to look at all of that so I + + align:start position:0% +experiment to look at all of that so I + + + align:start position:0% +experiment to look at all of that so I +mean they were very careful in this they + + align:start position:0% +mean they were very careful in this they + + + align:start position:0% +mean they were very careful in this they +figured out how to separate and that's + + align:start position:0% +figured out how to separate and that's + + + align:start position:0% +figured out how to separate and that's +the key thing for them to analyzing the + + align:start position:0% +the key thing for them to analyzing the + + + align:start position:0% +the key thing for them to analyzing the +concentration of cholesterol in these + + align:start position:0% +concentration of cholesterol in these + + + align:start position:0% +concentration of cholesterol in these +membranes and what they looked at we're + + align:start position:0% +membranes and what they looked at we're + + + align:start position:0% +membranes and what they looked at we're +over time but is the concentration of + + align:start position:0% +over time but is the concentration of + + + align:start position:0% +over time but is the concentration of +cholesterol compared to the total amount + + align:start position:0% +cholesterol compared to the total amount + + + align:start position:0% +cholesterol compared to the total amount +of lipids okay and + + align:start position:0% +of lipids okay and + + + align:start position:0% +of lipids okay and +how do they do that analysis you know + + align:start position:0% +how do they do that analysis you know + + + align:start position:0% +how do they do that analysis you know +there's Jean Kennedy who's at Harvard + + align:start position:0% +there's Jean Kennedy who's at Harvard + + + align:start position:0% +there's Jean Kennedy who's at Harvard +Medical School he's in his 90s now + + align:start position:0% +Medical School he's in his 90s now + + + align:start position:0% +Medical School he's in his 90s now +really trained all the lipid chemists in + + align:start position:0% +really trained all the lipid chemists in + + + align:start position:0% +really trained all the lipid chemists in +the whole country and they figured out + + align:start position:0% +the whole country and they figured out + + + align:start position:0% +the whole country and they figured out +many years ago how to separate lipid + + align:start position:0% +many years ago how to separate lipid + + + align:start position:0% +many years ago how to separate lipid +fractions with methanol chloroform + + align:start position:0% +fractions with methanol chloroform + + + align:start position:0% +fractions with methanol chloroform +extract something that you guys probably + + align:start position:0% +extract something that you guys probably + + + align:start position:0% +extract something that you guys probably +haven't thought about at all but we're + + align:start position:0% +haven't thought about at all but we're + + + align:start position:0% +haven't thought about at all but we're +really pretty good at separating things + + align:start position:0% +really pretty good at separating things + + + align:start position:0% +really pretty good at separating things +and it's nothing more than an extraction + + align:start position:0% +and it's nothing more than an extraction + + + align:start position:0% +and it's nothing more than an extraction +like you do as organic chemists to + + align:start position:0% +like you do as organic chemists to + + + align:start position:0% +like you do as organic chemists to +purify and separate things we figured + + align:start position:0% +purify and separate things we figured + + + align:start position:0% +purify and separate things we figured +that out and so then they use mass spec + + align:start position:0% +that out and so then they use mass spec + + + align:start position:0% +that out and so then they use mass spec +to allow them to quantitate the amount + + align:start position:0% +to allow them to quantitate the amount + + + align:start position:0% +to allow them to quantitate the amount +of glycerol and then in the end what + + align:start position:0% +of glycerol and then in the end what + + + align:start position:0% +of glycerol and then in the end what +they go so they use now spec they use + + align:start position:0% +they go so they use now spec they use + + + align:start position:0% +they go so they use now spec they use +western blots and they can change the + + align:start position:0% +western blots and they can change the + + + align:start position:0% +western blots and they can change the +concentration of the cholesterol and do + + align:start position:0% +concentration of the cholesterol and do + + + align:start position:0% +concentration of the cholesterol and do +the experiments over and over again to + + align:start position:0% +the experiments over and over again to + + + align:start position:0% +the experiments over and over again to +see what happens and when they do that + + align:start position:0% +see what happens and when they do that + + + align:start position:0% +see what happens and when they do that +this is the picture of cyclodextrin so + + align:start position:0% +this is the picture of cyclodextrin so + + + align:start position:0% +this is the picture of cyclodextrin so +you can see the only difference is this + + align:start position:0% +you can see the only difference is this + + + align:start position:0% +you can see the only difference is this +group here versus that with a methyl and + + align:start position:0% +group here versus that with a methyl and + + + align:start position:0% +group here versus that with a methyl and +one so this is hydroxy propyl hydroxy + + align:start position:0% +one so this is hydroxy propyl hydroxy + + + align:start position:0% +one so this is hydroxy propyl hydroxy +broeckel propanol cyclodextrin okay so + + align:start position:0% +broeckel propanol cyclodextrin okay so + + + align:start position:0% +broeckel propanol cyclodextrin okay so +it's like a cavity like this and all the + + align:start position:0% +it's like a cavity like this and all the + + + align:start position:0% +it's like a cavity like this and all the +other only other change here is a methyl + + align:start position:0% +other only other change here is a methyl + + + align:start position:0% +other only other change here is a methyl +group removing that and they have very + + align:start position:0% +group removing that and they have very + + + align:start position:0% +group removing that and they have very +very different properties about binding + + align:start position:0% +very different properties about binding + + + align:start position:0% +very different properties about binding +and releasing cholesterol which somebody + + align:start position:0% +and releasing cholesterol which somebody + + + align:start position:0% +and releasing cholesterol which somebody +had to do a lot of studying on to be + + align:start position:0% +had to do a lot of studying on to be + + + align:start position:0% +had to do a lot of studying on to be +able to ensure that they can use it to + + align:start position:0% +able to ensure that they can use it to + + + align:start position:0% +able to ensure that they can use it to +to remove cholesterol and then to add it + + align:start position:0% +to remove cholesterol and then to add it + + + align:start position:0% +to remove cholesterol and then to add it +back to the media and so you have to + + align:start position:0% +back to the media and so you have to + + + align:start position:0% +back to the media and so you have to +think about the exchange kinetics you + + align:start position:0% +think about the exchange kinetics you + + + align:start position:0% +think about the exchange kinetics you +have to think about a lot of things this + + align:start position:0% +have to think about a lot of things this + + + align:start position:0% +have to think about a lot of things this +is not trivial to set this up to figure + + align:start position:0% +is not trivial to set this up to figure + + + align:start position:0% +is not trivial to set this up to figure +out how to control the levels of + + align:start position:0% +out how to control the levels of + + + align:start position:0% +out how to control the levels of +cholesterol and then what they do is + + align:start position:0% +cholesterol and then what they do is + + + align:start position:0% +cholesterol and then what they do is +this is like a typical assay and this is + + align:start position:0% +this is like a typical assay and this is + + + align:start position:0% +this is like a typical assay and this is +the the end what you can do is this + + align:start position:0% +the the end what you can do is this + + + align:start position:0% +the the end what you can do is this +removes cholesterol and you can see it + + align:start position:0% +removes cholesterol and you can see it + + + align:start position:0% +removes cholesterol and you can see it +change this reports on low levels of + + align:start position:0% +change this reports on low levels of + + + align:start position:0% +change this reports on low levels of +cholesterol a lot which is happening + + align:start position:0% +cholesterol a lot which is happening + + + align:start position:0% +cholesterol a lot which is happening +over here allows the protein to move to + + align:start position:0% +over here allows the protein to move to + + + align:start position:0% +over here allows the protein to move to +the nucleus where it's smaller + + align:start position:0% +the nucleus where it's smaller + + + align:start position:0% +the nucleus where it's smaller +and that's how they knew the correlation + + align:start position:0% +and that's how they knew the correlation + + + align:start position:0% +and that's how they knew the correlation +the correlation between the levels in + + align:start position:0% +the correlation between the levels in + + + align:start position:0% +the correlation between the levels in +the nucleus and the levels of + + align:start position:0% +the nucleus and the levels of + + + align:start position:0% +the nucleus and the levels of +cholesterol so I thought this was a + + align:start position:0% +cholesterol so I thought this was a + + + align:start position:0% +cholesterol so I thought this was a +pretty cool paper and in these kinds of + + align:start position:0% +pretty cool paper and in these kinds of + + + align:start position:0% +pretty cool paper and in these kinds of +methods I think will be applicable to a + + align:start position:0% +methods I think will be applicable to a + + + align:start position:0% +methods I think will be applicable to a +wide range of things when if people are + + align:start position:0% +wide range of things when if people are + + + align:start position:0% +wide range of things when if people are +ever do biochemistry looking at the + + align:start position:0% +ever do biochemistry looking at the + + + align:start position:0% +ever do biochemistry looking at the +function of membranes so okay guys + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/kKyrR0cFrEg.txt b/kKyrR0cFrEg.txt new file mode 100644 index 0000000000000000000000000000000000000000..6a619193276cd6925fcfcb79fcbef93d7598efd9 --- /dev/null +++ b/kKyrR0cFrEg.txt @@ -0,0 +1,4289 @@ +ANNOUNCER: The +following content is + +provided under a +Creative Commons license. + +Your support will help MIT +OpenCourseWare continue + +to offer high quality +educational resources for free. + +To make a donation or +view additional materials + +from hundreds of MIT courses, +visit MIT OpenCourseWare + +at ocw.mit.edu. + +PROFESSOR: OK. + +Welcome back to +computational systems biology + +We have the honor +today of having + +Professor Ron Weiss visit us. + +As I told you on +Tuesday, he's going + +to talk about synthetic biology. + +And Ron is probably +from both the department + +of biological engineering and +the Computer Science department + +and also a founding member +of the Synthetic Biology + +Center at MIT. + +And now, thank you, Ron. + +PROF. + +RON WEISS: Thank you, Dave. + +Thanks for inviting me here. + +Did you mention our background? + +Dave was actually-- +advised me when I first + +came to our graduate +school at MIT. + +And at the time, I was +working on digital video + +and information retrieval. + +And Dave started getting +into the business of biology. + +This is back in the early '90s. + +And I was like, this is cool +stuff but it's really messy. + +How can you engineer +with these molecules? + +PROFESSOR: And we've +got the answer to that. + +PROF. + +RON WEISS: Yeah. + +So we'll see. + +So let's see if the answer +is-- it does actually work. + +So yeah, so I-- after being +a non-believer-- I don't know + +if non-believer, but just-- +I didn't feel I quite + +had the engineering +capabilities. + +Towards around '96 +or so is when I + +decided to actually +make the switch. + +At the time, I was +working-- around '96, + +I was working at this +notion of how can we + +use what we know in biology +to understand how we program + +computers and especially +situations where you have + +lots and lots of computing +elements like-- things + +like smartDOS. + +I don't know if people have +heard, but amorphous computing. + +So back in the mid +'90s or so, this notion + +that we would be able to +embed computation everywhere + +was kind of an exciting notion. + +And I thought to myself, where-- +how could I get inspired? + +And I thought, well, +biology obviously + +could serve as +great inspiration. + +Because that's a situation where +you have millions or billions + +of little computing +elements that + +don't have too much power, +kind of interact locally. + +But they still perform +very robust operations. + +And so I performed a +variety of simulations, + +for example, of embryogenesis +and other processes + +to try to understand what +happens in biology and can + +I again use that to +program computers + +or little tiny computers. + +And I remember one +day, I just decided + +to flip the arrow and +basically rather than trying + +to use biology to understand or +program computers, I decided, + +let me use what I know +in computing to actually + +try to program biology, OK? + +And so now that +field is basically + +called synthetic biology. + +So I've been in that field-- +it's hard to count now, + +but I guess maybe +18 years or so. + +And it's been fun and +has not been easy. + +But I think at +least we're starting + +to make some-- we're +making some progress. + +So I'll try to tell you about +some of our efforts there. + +And I certainly encourage +you to ask me questions. + +So please interrupt me +at any point in time. + +Any kind of question +is fair game. + +Dave promised me that you +guys are a tough crowd. + +So let's see. + +And you can always stump. + +Let's try to have that happen. + +So when I look at this, I get +excited as an engineer, OK? + +And I think to myself, wow. + +This could be really cool to +be able to program something + +like this, again, +in the same way + +that we may program computers. + +And so this notion of genetic +engineering in a direct way, + +in a way where we +can create new DNA, + +certainly has been around +since the '70s or so. + +And so this notion +has allowed us + +as a community to create +various mechanisms that + +control what the cells do. + +So for example, transcriptional +regulation, translational-- so + +being able to regulate +things in a cell, + +be able to create +genetically encoded sensors, + +cell-cell communication +mechanisms, synthesis + +of various interesting +molecules-- + +biofuels, pharmaceuticals, +and control physical aspects. + +And so those capabilities +have been around + +before synthetic biology. + +But if you were +to ask me what is + +different about +synthetic biology, + +I would say it's really the +emphasis on systems level + +engineering. + +OK, so this notion +that we are not just + +trying to engineer +over expression + +of this gene or that gene +or a couple of genes, + +but really trying +to understand how + +to create systems +of interactions. + +So in the same way that +systems biology has + +come to the forefront +with this notion + +that you can't understand a +cell by understanding what + +is the exact purpose of this +particular gene-- we always + +have to think about it within +the context of a pathway + +within the context of the entire +organism-- in the same way, + +when we want to be able to get +cells to do interesting things, + +we have to think about +the system as a whole. + +And to get the +sophistication that we need, + +we need to understand how to +connect these various elements, + +regulatory elements, all +these kinds of elements, + +in reliable, predictable +ways, efficient ways + +and so on to be able +to get the cells to be + +as programmable as computers. + +So that if you were to ask +me what synthetic biology is, + +that would be my answer. + +And so now you know it and +you can tell all your friends + +that it's a completely +defined notion and so on. + +Maybe if yo ask +other people, they'll + +give you slightly +different answers. + +But there you go. + +So how do we develop an +engineering discipline out + +of that? + +OK, so that's really how +can we get undergrads + +to come in and take Synbio +101 where it's really + +a well defined mechanism and set +of methodologies and practices + +that allow us to +do this reliably. + +OK, and so we often +try to get inspired + +by how other +disciplines approach + +the engineering of +complex systems. + +And so kind of an +obvious one would + +be of computing +or robotics where + +there's this notion of, for +example, bottom up assembly. + +And so you start +with basic devices + +and think about how +to create modules + +that have specific behaviors in +them and then put those modules + +and integrate those modules +to create these autonomous + +entities such as robots. + +And we often think about +how to create communities + +of interactions, communities of +robots in this case, and so on. + +And so that's worked +quite well in a variety + +of different other +engineering disciplines. + +And so we often +ask the question, + +can we import these mechanisms +into the world of biology? + +So can we take basic +mechanisms of regulation-- + +it could be +transcriptional, it could + +be other modes of regulation-- +and then wind these things up + +to create customizable pathways +that we then embed into cells? + +And then we can create +programmable communities + +of bacteria. + +We can create programmable +tissues of mammalian cells + +and so on. + +And so the question is, is +this a useful and efficient way + +to approach things? + +So for example, how are these +different approaches similar? + +What can we borrow +from here that + +make sense to push +on over there? + +And I will say when +I started working + +in synthetic biology, +most of my efforts + +were really focused on +adapting and implementing + +these things-- so adapting +them from other disciplines + +and trying to understand how to +implement them into the world + +the biology. + +But as time has +gone by and as we've + +started to understand and +appreciate the cell more + +and more, we are also +quite interested in how + +these things are +different as well. + +So what makes engineering +biological systems + +a truly unique, new +engineering discipline? + +What would you do in +the world of biology + +that might be different +than what you would + +do with computers or robots +or building bridges and cars + +and planes and so on? + +And so that that's become more +and more of an important focus + +in my lab and I think in +the community as a whole + +although not yet everywhere. + +And you often see +situations where + +people come in from other +disciplines and just think, + +oh, we'll just program +it, engineer it, + +just like we do in +computing and so on. + +And it doesn't just +work like that. + +So when we approach these +tasks of programming the cells, + +we usually divide things up into +modules of sensors, processing, + +and actuation. + +So for example, we would +want to develop sensors + +that can detect in live cells +levels of microRNA messenger + +and then proteins +and then connect them + +to synthetic regulatory circuits +that we embed in the cells, OK? + +So it's important that these +sensors not just, for example, + +give us fluorescent +readouts, but it's important + +that these sensors then connect +to the regulatory networks + +that we have in mind and so that +these regulatory networks can + +then integrate multiple +pieces of information + +and make decisions +about actuation. + +So how do we turn on specific +proteins that will then + +influence that +particular cell or even + +the environment in a +programmable fashion + +as dictated by the levels +of particular sensors + +as well as by other +mechanisms or, for example, + +from looking at +historical information + +that the cell itself +has processed as well? + +And so this is, I +would say, represents + +the paradigm for most +of the things that + +do take place in +synthetic biology. + +And so why do we +want to do this? + +It's not the program the next +version of the iOS or iPhone + +or something like that. + +even though that +initially that was + +one of the things +that was discussed, + +it's not just for the +sake of computation, + +but really for the sake +of specific applications. + +So for example, if we have +really slow logic gates that + +work on the order of +hours or even days, + +that might be fine if the +application, for example, + +is a tissue engineering +application, OK? + +And so in synthetic +biology, initial emphasis + +is really been on what +can we do with microbial, + +let's say, communities or +individuals, for example, + +for synthesis of +high value compounds? + +I mentioned bioenergy, +environmental applications + +as well. + +So that, I would say, was +most of the emphasis there. + +But over the last +few years, there's + +been a growing interest in +health-related applications. + +And so my lab in particular +looks at mostly health related + +applications. + +And so I'll give you +examples of those today, OK? + +And those include things +involved with cancer, diabetes, + +in tissues by design. + +And in order to +do this, in order + +to have this programmability, +you want to think about scales. + +So you want to think about how +much DNA does it take to do X? + +And to a large extent, that +controls the sophistication. + +It really is an important +defining element + +what we do is the +scale of the DNA + +that we can actually +engineer reliably quickly, + +efficiently, predictably, +in high throughput fashion, + +and in inexpensive ways. + +So we would start with +things on the order of genes + +where I would say that that's +really the basic elements. + +I would say that a single +gene that you overexposes + +or a few genes than +you inducibly express, + +I wouldn't count that +as synthetic biology. + +But when it gets +kind of interesting + +for synthetic biology is +when we have this circuitry, + +where we now embed interactions +that didn't previously + +exist in that +particular cell context. + +And so most of synthetic biology +has been really at this level + +right here-- actually, +mostly from here + +to here in terms of +the scale of the DNA + +and now trying to go beyond +that-- more along the lines + +can we create something +that's 20,000 bases, 50,000 + +bases of DNA? + +OK, is this something that +a graduate student can + +come into the lab +and say, I want + +to design something that will +take 20,000 to 50,000 bases? + +Is this a reasonable +thing to consider? + +OK, and then the question +would be, what kind of power + +does that provide to you? + +What things can +you do with that? + +Beyond that, people have +explored this notion + +of minimal life and even +full genome rewrites. + +I would say at this +point, this is-- + +what some people clump that in +with synthetic biology, which + +is fine. + +We don't have, at the +moment, really good ways + +of being able to engineer +minimal life from scratch + +or even in a really +fundamentally different way. + +So most of the efforts +on minimal life + +would be take an +organism and try + +to figure out what to knock out, +right, as opposed to saying, + +I'm going to engineer +this new minimal organism. + +And I'm going to +define what reactions + +to put in there from scratch. + +And I'm going to create +a whole bunch of new ones + +that didn't exist before. + +OK, in the future, will +we be able to do this? + +Hopefully, OK? + +Not quite yet-- this is really +where the action of right now. + +And again, driving +force for this + +is how inexpensive +is DNA synthesis. + +And so we're following +some kind of Moore's law + +with respect to dropping costs +in terms of DNA synthesis. + +And this is one +of the enabling-- + +I don't know if it's-- it's not +the only enabling technology. + +But is one of the most +important enabling technologies + +is the fact that +it is less and less + +expensive to be +able to order longer + +and longer sequences of DNA. + +And so this notion +that, for example, + +you'll be able to design +something that's, again, + +that's 20,000 to +50,000 bases of DNA + +and just go online +and order to that + +and have your advisor +willingly pay for that-- not + +at the level of 20,000 +to 50,000 bases yet. + +But that's going to change. + +And that's going +to get to the point + +where those really become +available to everyone. + +And I think that's going +to fundamentally change + +how we do business in +biological engineering + +and how we do, I would +say, almost everything + +in biology as a whole. + +So if you have-- even if you +don't care about engineering + +new biological +functions but you want + +to understand biological systems +and your adviser told you, + +well, just design a whole bunch +of circuits that will allow you + +to regulate things +in arbitrary ways + +to learn something about +the underlying networks that + +control a natural +systems, again, I + +think that that fundamentally +changes what kinds of questions + +you will ask. + +OK, so I'll talk +about basic design. + +I'll talk about scalability. + +So how do we go from +these basic elements + +to bigger and bigger things? + +And then I'll talk +about some recent things + +that we're doing where we're +building this foundation. + +But we think that this +foundation then can matter. + +I think this foundation can +change how you approach things + +that really don't have +the greatest of solutions. + +Now, they really change +the paradigm, for example, + +for cancer, for this +notion of building tissues + +by design on chips and +for diabetes and so on. + +OK, so we start with parts. + +So just about +everything that we do, + +we define what are +the basic parts that + +are available in our toolbox. + +And so these will be +transcriptional regulatory + +parts. + +We do things at the +translational level. + +We do things also at the +protein-protein level. + +One of the things we +often do, not always, + +is engineer cell-cell +interactions. + +Could be by means of +cell-cell communication. + +We often want to find out +what's going on in the cell. + +So just like when +we program-- where + +we create a new software, +new computer program, + +we have debugging +outputs that tell us + +what the program is doing. + +Usually, the way we do this +is with fluorescent protein. + +It could be with dyes too. + +So they tell us, +you know, here's + +how your circuit is behaving. + +Here's how the cell +might be behaving. + +And another set +of parts would be + +ones where we want to be +able to create sensors + +and actuators inside the cell. + +What are specific +biomarker levels? + +How can we affect what +the cell is doing? + +For example, one +that gets used a lot + +is kill the cell is one +of the favorite actuators + +that people are using. + +Another one would be, let's +say, tell this stem cell + +to differentiate into +a different cell type. + +That would be another +kind of actuator. + +A different one might make the +cell-- make this high value + +compound that would be +relevant for some application. + +And so right now, if +you're looking for parts, + +they actually used to be +stored in Stata up until-- + +or big libraries of +synthetic biology parts + +were stored in Stata that up +until about two years or so. + +So I don't know how many +people know about iGEM. + +Any folks know about iGEM? + +So iGEM was started at +MIT, was headquartered, + +as I mentioned again +here, in Stata. + +There are these couple of +big freezer that were on the, + +I think, the fourth floor here. + +And they stored +5,000 to 10,000 parts + +that word commonly used by +synthetic biology folks. + +OK, so now they +moved over closer + +to Cambridge brewing company. + +And they're not affiliated +directly with MIT anymore + +and they have 15,000 +parts or so available. + +So if you want to get +started in synthetic biology, + +this is one quick +way to do that. + +You can contact iGEM +headquarters and say, please + +send me 1,000 parts, OK? + +And as long as you're +credible and not + +from one of those +blacklisted countries, + +then they typically +will send it to you. + +So that's a good way +to get started, OK? + +So what are these parts? + +So this is actually going +back to my Ph.D. here. + +This is one of the parts +that I characterized. + +So this notion of an inverter-- +so digital logic convert. + +So I assume people +here-- everybody + +is familiar with logic gates. + +Is that true? + +OK, raise your hand if +you are familiar with it. + +I just want to see- oh. + +Just trying to calibrate-- +and again, ask me questions. + +So this notion that you have +a single input, single output + +device that works on binary +values that has-- basically + +inverts the signal. + +So you have zero on the input. + +You have one on the output. + +One in the input, you +have zero in the output. + +And so one of the +ways in which you + +can implement this in +a biological system + +is just use +transcriptional repression. + +OK, so if you have +no repressor present, + +then you have a high +level of output protein. + +If you have a +repressor present, it + +represses the production +of the alpha protein. + +And so in theory, you +should be able to use + +this as a digital logic gate. + +OK, and so that-- sounds-- +looks pretty simple here. + +But for my Ph.D., it +took me about three years + +to do something like this just +to give you an indication. + +Now it's a lot faster. + +Now you can do this in-- you +can do many of those in a day. + +So there has been progress. + +Here's another one of those +gates that I used for my Ph.D. + +And so this is now not just a +repressor, but a repressor that + +can be inactivated by +a small molecule, OK? + +And so the way it +works is you have + +this repressor that +works as before. + +And then when a small +molecule comes in, + +it prevents a repressor +from binding the promoter. + +And as a result of that, even +if the repressor is present, + +you can have activation +of the output protein, OK? + +So this is what's called a +not x or y or it implements + +the implies logic function. + +How many people use the implies +logic function to do anything? + +OK. + +So it's not a commonly +used logic function. + +And you won't find it-- +there's no logic gate that + +does the implies logic +function in a typical computer. + +But this is a useful +logic function + +that we can implement in cells. + +And it allows external control +of gene expression, OK? + +And so this is a +simple way-- and so + +once you can do that as +a user, essentially you + +can interact with +the cells and modify + +what's going on inside the +cell, OK, using a pretty simple + +looking mechanism that predates +synthetic biology, if you will. + +But I don't know if it was +called the implies logic + +function before. + +So anyway, so then logic gates-- +can we build logic circuits? + +This is where I would +say synthetic biology + +starts kicking in. + +And so this is one of the first +logic circuits that we built. + +And the question was, OK-- looks +nice to have this logic gate + +representation. + +In biology, does this +make any sense at all? + +Can you really do digital +logic inside cells? + +Can you take noisy +biological components + +and actually implement reliable +digital computation in cells? + +And it wasn't an obvious +thing, I would say. + +Is it 100% obvious now? + +In some situations, +I think we can + +claim that we can build +digital logic that's + +reasonably reliable. + +So in this particular case, I'm +showing you this implies logic + +function that allows us +to have small molecule + +induction of a +cascade of not logic + +gates or transcriptional +repressors. + +And so the nice thing +about this in particular + +is the fact that this is the +input output steady state is + +that as the circuit so +goes from blue to black + +to this yellow color here is +as the circuit gets longer, + +as a cascade gets longer, it +actually becomes more digital. + +It actually becomes +more step-like, OK? + +More on off. + +So we're going from this +blue input output function + +to this yellow. + +So now we have over +1,000 fold change + +in the output in +response to two to four + +fold change in the input. + +OK, and then we have +good noise margins, + +good signal restorations, +all these good things + +that we need to have for +the creation of larger + +and larger reliable +digital circuits. + +So the basis of digital +computation is that you have-- + +and the reason why you can +actually create computers + +is that you can have logic gates +that do signal restoration-- + +that the output is a +better representation + +of the digital meaning +then the input. + +So as the signal , propagates +this analog signal could be + +voltage. + +But it could be +protein concentrations. + +As it traverses through +the logic gates, + +it needs to actually become +cleaner in order for us + +to be able to have reliable +digital computation. + +So people have figured +out how to do this + +with electronics +a long time ago. + +We figured out how to do it +with synthetic biology, let's + +say, 10 to 15 years ago. + +And nature has figured out how +to do this billions of years + +ago, OK? + +So things like +cooperativity-- so I + +assume you've looked a +little bit on cooperatively + +in, let's say, gene regulation. + +OK, so that is a situation +where you get a nonlinear + +response in a system that +biology has figured out + +is a useful mechanism so that +signals that come in actually + +result in some kind of +actual digital behavior. + +So you get non-linear +signal processing + +in these regulatory elements. + +And at the end of, let's say, +a signal transduction cascade, + +the output is +either high or low. + +There's no-- for the most +part, there's no in between. + +The transition between +high and low is super fast. + +OK, so in a sense, +that's creating + +digital or discrete outputs. + +And that's really critical +for many situations-- + +certainly in synthetic biology, +but many situations in biology + +as well. + +So one example would be, let's +say, stem cell differentiation. + +You want the cells to be able +to make a discrete decision. + +Should I make-- should I +become a kidney cell or a liver + +cell or a muscle cell and so on. + +So those are discrete +decisions that + +have to be made by the cells. + +And so the cells have +come up-- or nature's + +come up with mechanisms +to guarantee that. + +And so we've now figured +out how to do that ourselves + +in a synthetic fashion as well. + +It's important to note that +when we engineer these systems, + +we don't just think +about digital behavior. + +So we spent an equal amount +of time perhaps thinking + +about how to implement things +that have transient properties + +or things that have more kind +of analog behavior to them. + +And that's absolutely critical +to be able to program cells + +to do whatever we want. + +So this is an example +where we have engineered + +cell-cell communication +where sender cells make + +a small diffusible +molecule which + +then goes to receiver cells. + +OK, so now the receiver cells +don't just have an on response, + +but rather they +have a pulse, OK? + +So a signal travels from the +sender to the receiver cells. + +And the cells, what +we engineer them to do + +is have a pulse response. + +And the idea is to have GFP +go up-- a Green Fluorescent + +Protein go up-- +and then go down. + +And so to be able to +do that, we engineered + +a feed forward +motif where we have + +binding of the small +molecule to this activator + +which activates two +things simultaneously-- + +a green fluorescent +protein and a repressor + +which then represses the +green fluorescent protein. + +And then-- so the idea is that +the green fluorescent protein + +goes up. + +And then eventually, +the repressor + +builds up to sufficient +levels to repress + +the green fluorescent protein. + +So again, one of those +simple looking motifs. + +This is about three +years to actually make + +that happen around +the 2004 frame. + +Looks simple. + +If you study a naturally +occurring system that + +has this motif, you say, +oh yeah-- no problem. + +Yeah, we have this +feed forward motif. + +And obviously, you can do this +kind of information processing + +function. + +Let's move on to another motif. + +You actually try to build this +in a lab in a new organism, + +I'm not sure if it +can drive you insane. + +But it is not trivial to +actually make it work. + +It's much easier now +than it was 10 years ago. + +But you still have +to pay attention + +to a lot of things-- rate +constants, threshold matching, + +and so on to actually +make it happen. + +But eventually, after +looking-- creating-- + +so this is our first +attempt at this + +was this blue line right here. + +So a completely flat line, OK? + +Input comes in, nothing happens. + +So I would say that pretty +much typifies synthetic biology + +maybe up until today. + +You build something. + +You think it's going to work. + +It doesn't work. + +And then you stop crying +after a little while. + +But then you have to think +about how do I fix this. + +And so this iterative +design debug cycle + +is absolutely critical. + +So what you normally do is you +create computational models + +that tell you how different +rate constants in the system + +affect the behavior +of your circuit, OK? + +For example, you could +do sensitivity analysis. + +Which rate constants +have the most influence + +on the performance +of your system? + +And so we did some sensitivity +analysis here and learned + +that, for example, the +degradation of this repressor + +makes-- one of the +things rate constants + +makes the biggest difference +is on the performance + +of the system or its +affinity to the binding + +site on its respective promoter. + +Yes. + +AUDIENCE: Just knowing the sheer +[INAUDIBLE] entire circuit, + +it started off with the +[INAUDIBLE] constant? + +PROF. + +RON WEISS: No. + +I wish it was. + +Because that would +make life a lot easier. + +And we are trying to +get better at that. + +So we're trying +to-- so here's maybe + +two ways of thinking about that. + +One challenge would +be somebody comes in, + +gives you DNA +sequence, and you have + +to predict the rate constants. + +OK, so I would term that person +an adversary, not your friend. + +It's just too hard to do that. + +Now, an easier task would be +give your adversary or friend + +limited choices and +say in the freezer, + +I have these DNA +sequences that consist, + +let's say, of +specific promoters, + +specific ribosome binding +sites, specific proteins + +with specific degradation +tags on the proteins, OK? + +And that's-- you're allowing +that adversary or friend + +to only use those elements +in the design of a circuit. + +And then they come back +to you and they say, + +now predict what +the circuit will do. + +You still-- it still +doesn't work yet. + +But I think-- but I +would say that's how + +we would phrase +the challenge, OK? + +Stick to things that we know and +allow us to even characterize + +those things ahead of time. + +What we have that-- +unfortunately, + +I don't have that here. + +But what we have +done-- so people + +can get a kind of a +general characterization. + +So they can say it'll be roughly +this input output behavior. + +And when I say +roughly, the errors + +could be on the order +of five to 10-fold. + +That's approximately what's +been published so far. + +Now, five to tenfold +depending on your perspective + +could be great because +it's biology or could + +suck if you're an engineer. + +It just depends on if you're +trying to do something + +like get green +fluorescent protein + +to turn on and off, +tenfold is probably great + +if you're doing this +in a Petri dish. + +If you're trying to +create a cancer classifier + +circuit you put into +humans to kill cancer cells + +but not harm healthy cells, +tenfold is probably not + +great I wouldn't take +a circuit like that + +into me, especially if that +circuit controls, for example, + +the production of a +killer protein, which I'll + +try to show you a +circuit that does that. + +We recently have +been able-- we're + +in the process of submitting +a paper about this-- been + +able to show that if you have +really good characterization + +of regulatory elements such +as these repressor devices-- + +and you have to do a lot +more characterization + +and you do the-- we can +get within 20% on average + +on predicting the behavior +in mammalian cells, actually. + +And so as an +engineer, I would be + +happy with 10%, 20% percent +for many, many applications. + +So I think we've +gotten better at it. + +But it's not quite perfect yet. + +One of the things +about that approach + +is that we don't +necessarily know + +the rate constant +for everything. + +What we do know, however, +is a very detailed behavior, + +both steady state +and dynamic behavior, + +of a repressor promoter pair. + +So we don't know, for example, +what's the binding affinity + +or what's the rate +constant for the repressor + +binding the promoter, +what's the rate + +constant for RNA polymerase +binding that promoter, what's + +the exact translation rate +or transcription right too. + +But we do know what's the +input output behavior. + +And that's actually been enough +to get really good predictions. + +But I would say these +kinds of predictions + +are one of the most important +aspects and challenges + +and bottlenecks of +synthetic biology. + +So those include-- +again, the challenges + +include how fast +can you build DNA. + +But wouldn't it be nice +if you can actually + +predict what the DNA does? + +So it's just as +important, if not more. + +And also having-- +so those are two + +of the important challenges. + +I'd say another +one would be-- OK, + +so if you can predict +things how many parts + +do you have in your freezer that +you can actually put together + +and they're +well-characterized actually + +now build the circuits? + +Probably three of the +most important challenges. + +And so if you go back to what +we'll call the post generator, + +this is a loop tape of bacteria +that now respond to the pulse. + +So sender cells that then +secreted the small molecule + +then went into receiver cells. + +And they light up. + +So one of the things to +note here is that it works. + +The other thing to note here is +that it's not perfect, right? + +And so the amount of +heterogeneity here I think + +is quite astounding. + +So if you take the +average behavior, + +it's actually quite predictable. + +But if you now start +looking at the distribution + +in the response, +it's staggering. + +And we quantified that. + +And so we quantified what's +the distribution in terms + +of the fluorescence levels +that-- the peak and also + +the buildup and so on. + +And we then correlated +that also-- we + +created the stochastic +simulations that then correlate + +reasonably well with the system. + +So we can get simulations +to generally correspond + +with what we're seeing +at the population level. + +But I do want to +bring up this point + +that when you think about +engineering biological systems, + +don't try to figure out how to +engineer a single cell to do + +something reliably, OK? + +So you always want +to think about kind + +of statistical engineering. + +You want to think about, I'm +going to create a circuit. + +And when I put this circuit +into a population of cells, + +this is the distribution +of behaviors + +that I'm going to get. + +Because if you're +trying to depend + +on any individual cell giving +you exactly the behavior + +that you're looking for, it +is just-- it's going to fail. + +So you have to really +think about distributions. + +And that I think changes +things a little bit. + +So that's not +normally the way you + +think about-- maybe +that's the way Microsoft + +thinks about programming. + +So if 90% of the time, the +computer doesn't crash, + +that's pretty good. + +Probably Bill Gates +agrees with that, right? + +But that's not what we want. + +That's not what we +typically do with software. + +So to kind of further +think about this + +in terms of populations, +we program something else + +which was a pattern formation. + +So now we have the desire to +create senders and receivers + +where the senders send the +same message to the receivers. + +Now we have a longer +feed forward motif. + +OK, so this feed forward +motif has two branches. + +And so these two +branches actually + +have a different impact +on the final output. + +One has-- there's two repressors +meaning that input comes in. + +It activates a fluorescent +protein and another one + +represses the +fluorescent protein. + +OK, so it's an incoherent +feed forward motif. + +And so what we use that here +is not for post generation, + +but rather to define a +range of concentrations + +that would turn on +the final output, OK? + +So it would be activated-- +the range of concentration + +would be activated starting +with this branch right here + +and then ultimately +repressed by this. + +So this defines the +low threshold and this + +defines the high threshold. + +So under the low threshold, +nothing gets activated. + +Whenever you have +just the right amount, + +it activates this +which represses + +this which allows this +fluorescent protein + +to get turned on. + +OK, so this branch right +here is more sensitive. + +So it defines when +this thing goes up, + +when the response goes up. + +And then this is less sensitive. + +So this defines under +high concentrations + +when the output goes down. + +So we basically have a +non monotonic response + +to the input, which is +low then high then low. + +So that's the design +that we had in mind. + +And the idea is that +whenever you put, + +let's say, receiver cells +everywhere in a Petri dish + +and you put senders +in the middle, + +then the communication +signal basically builds up. + +There's a chemical gradient. + +Each cell interprets +the chemical gradient + +and then decides whether to +make a fluorescent protein. + +And then only-- because there's +this steady chemical gradient + +due to diffusion and +decay of the signal, + +then you would get some +kind of a bullseye pattern. + +So that was the hope at least. + +And so to give you again +a timescale, so it took me + +about I think three hours on +a plane to make the slide. + +It took us about three weeks to +create the computational model. + +And again, for whatever +reason, three years + +was the magic number to create +the actual functional circuit. + +So that was an older +version of PowerPoint. + +But I haven't tried +it on the new. + +But anyways, so we created this. + +This is a computational model. + +We actually used a +computational model + +to predict how changes +in rate constants + +would affect this band detect, +the region where we're actually + +responding to the signal. + +And we used that to engineer +different responses. + +And so we created eventually +three different responses input + +versus output. + +And we put different +fluorescent proteins on them-- + +a red fluorescent protein and +a green fluorescent protein. + +This is the experimental +set up over here. + +And after 16 hours of waiting, +this is basically what we got. + +So we got a lot of bacteria +to make all kinds of patterns. + +And we were very +happy about this. + +We danced around in the lab +a little bit-- you know, yay! + +So this was fun on those rare +occasions where things actually + +work. + +So we said, let's +have some more fun. + +And so we put senders +in other configurations. + +And so we have +programmable patterns + +of bacterial communities. + +So I'm not sure +of is this useful. + +I'm not sure by itself besides +having some fun with it. + +But one of the things we're +using this for right now-- + +and depending on time, +I may get to that + +later-- is this notion of +embedding these circuits + +in mammalian stem cells or +actually also in human IPS + +cells so that we engineer these +human IPS cells to communicate + +with one another +to make decisions. + +And then those +decisions actually + +lead to differentiation +patterns, right? + +So you can imagine +in principle, if you + +can create three dimensional +versions of these + +and use those to cause the +cells to make differentiation + +decisions so that red +would mean make neurons, + +green would mean make muscle, +different colors-- yellow + +would mean make bone and so on. + +So in principle, you might +be able to create tissues + +by design. + +OK, so that's something that +we are working on actively + +in the lab right now. + +So we don't quite have a working +heart in a Petri dish yet. + +We won't for a little while. + +But we taking some baby +steps along the way. + +And so we have been able to +get cell-cell communication + +to work. + +We've been able to get +programmed stem cell + +differentiation to work. + +And hopefully, I'll +be able to show you + +some images that we have of +some recent examples where + +we take human IPS and actually +created these embryonic liver + +buds that have lots and +lots of interesting-- + +and actually all +the cell types that + +are known to exist in +the embryonic liver. + +So there are some +progress along the way. + +Now, we don't anticipate +to replace your liver, + +you know, any time soon. + +So don't destroy it. + +So actually one near +term application + +that we're +specifically looking at + +is if we can take-- imagine +taking your own fiberglass, + +de-differentiating them +into human IPS cells-- + +those are your human IPS cells-- +and then differentiate them + +into, like, this +liver-like environment + +and put that in a +Petri dish and then + +test out the effect of +drugs on your mini liver. + +OK, so maybe it's a +good idea to test drugs + +on things that resemble +human tissue as + +opposed to some random +mouse that may or may not + +be as correlated with what +the drug would actually + +do to actual human cells. + +And if we actually even do it +in the patient specific manner, + +I think that really +changes the way drug + +development would actually work. + +And that's something that I +think within the next few years + +could become a reality. + +They're talking about +the next-- beginning + +to do that within the next one +to three years in a laboratory + +setting. + +So I think that is near +term and realistic. + +So one of the things +that we did notice + +is that when we engineer +the small systems, + +its intuition works quite well. + +So I can look at +this circuit design + +and say, if I modify this, +this is what's going to happen. + +If I modify this, that's +what's going to happen. + +So you can use intuition and +it works reasonably well. + +And what happened in I would +say the first 8 to 10 years + +of synthetic +biology, every paper + +would have a +computational design. + +But most of those +would build something. + +And in order to publish, we also +tacked on a computational model + +that correlates really well +with the experimental results. + +And we are just as guilty of +doing that as anyone else, OK? + +So it wasn't critical to +have a computational model + +to create something +successfully in the lab. + +And I think that +that is changing. + +So we have examples right now +of designs where-- I'm not sure + +if I'll get to that today, +but we have published + +on that-- designs +where it involves + +about 20 to 25 components. + +And it's related to +a diabetes system + +the retired engineer where we +can have intuition about it. + +But our intuition doesn't +work great anymore, guys. + +So we might have some +intuition about the system. + +But the computational +analysis would all of a sudden + +shed light and +provide insight that + +is very difficult to +get this by drawing + +this thing on a blackboard. + +OK, and so I think that +computational design tools are + +becoming absolutely essential. + +They can provide insight +into system behavior + +that you can't get just +using intuition alone. + +But in another aspect +of computational design + +is one where imagine being able +to specify want this behavior. + +And then the +computational design tool + +says, here's 1,000 different +versions of circuits + +that you should build and test. + +OK, and so it's still +difficult for a human + +to generate easily 1,000 +different versions of a circuit + +to build and test. + +It is becoming easy +to actually build-- + +I wouldn't say-- maybe +easy is a strong word-- + +feasible to generate +1,000 versions + +of a particular circuit. + +I'll give you an example. + +Very recently in my lab, +one of the graduate students + +has come up with a +framework that-- he + +is generating 200 versions of +a circuit in three hours, OK? + +And they're pretty much +gotten to the point + +where they're all correct. + +In three hours-- +so that really, I + +think, changes what you +do in synthetic biology. + +And so again, having +that be connected + +to a computational design +tool that tells you + +which ones to build +would be rather useful. + +And so specifically +recognizing that-- this + +is a collaboration +with some folks at BBN. + +And actually Jake Beal was one +of my former graduate student + +colleagues. + +So he was in the same lab as me. + +And then Doug Densmore is +from Boston University. + +And so the notion +here is that this + +is what we want synthetic +biology to look like. + +OK, so if you're +trying-- or maybe + +all of biological engineering. + +But we'll start with +synthetic biology. + +So if you want to +program biology, + +should you really care +what the ribosome binding + +site is for the +lambda repressor? + +You know, hopefully not, right? + +What you should +do, just like when + +you program your simulations in +MATLAB, you don't think about, + +well, here's the shift register +in this Intel Pentium chip. + +And this is how it's working +to simulate this ODE over here. + +That's just not the level +at which your program. + +So you think really +at a high level. + +And then you have compilers +and lots of infrastructure + +that takes care of +everything in between. + +And so maybe someday in the +future, the graduate students + +maybe five to 10 years will +look back at synthetic biology + +graduate students +now and would just + +have a lot of pity for +them and, oh my god. + +You actually had to +know what elements + +you were using in circuit and +actually build them by hand? + +You know, wow. + +And so here's a notion that +we start with a high level + +description. + +And by the way, this +is now-- there's + +a website that you can go +through right now and get + +a free account and then type +in a high level program. + +And it will actually create +a low level genetic circuit + +representation. + +It will also give you MATLAB +simulation files of this. + +And so, in this course +I'm teaching to undergrads + +right now that many of them +didn't even hold pipettes + +before they started the +course, one of the first things + +that we taught +them was this tool. + +So before telling +them, for example, this + +is the way the lac repressor +works by DNA looping, we said, + +there are these things +called repressors. + +And when there's more of +them, there's less output. + +Now let's design with that. + +This is, I think, heresy to +biology as a whole probably. + +I don't know that-- this is the +first time that we've actually + +tried to do that. + +And I think it's +actually worked out OK. + +But teach them enough so +that they can move forward. + +And then, yes, +let's simultaneously + +be teaching them about +the underlying biology + +and mechanisms as much +as they need to know. + +But what can they +do if they just + +know that there's +this thing called + +a transcriptional repressor? + +And then the bio +compiler will figure out + +everything that needs to happen. + +And so we're actually-- so they +did a whole bunch of designs. + +And starting next week, we're +going to be testing them out. + +So we will find out whether +that was a useful way + +to teach biological engineering. + +But I think so. + +I think it is. + +Because they seem to understand +what design means, OK? + +Because that's a thing +that we focus on-- design + +as kind of a first class object. + +OK, so what you do is you write +code that looks like this. + +Has anybody programmed in +code that looks like this? + +It should be-- so Lisp. + +OK, one person only? + +Any computational? + +OK, we usually get +one or two people. + +But I was hoping for more here. + +So anyways, for the people that +should be ashamed of themselves + +and haven't programmed in +lisp, this is a simple program. + +This is, if the +input is high, it + +produces cyan +fluorescent protein. + +Or else, it will produce a +yellow fluorescent protein. + +And so the bio compiler then +automatically takes that + +and first translates +that into a data flow. + +So you have a data +flow-- and I'll + +actually go through +an example of that-- + +and then creates an +abstract gene circuit + +and then looks at essentially +what you have in the freezer + +and says, well, this +is the actual DNA + +sequence that would +implement this. + +And it creates robot +instructions to assemble this + +so that God forbid you +would have to actually touch + +a pipette to build this. + +And then we have a robot, +liquid handling robot, + +that does most of the assembly. + +Now, this pipeline is +not fully end to end yet. + +So it's not-- if you came to +my lab right now, the still-- I + +could tell you that +this works but then I + +would be slightly lying. + +Is-- mostly works. + +But it's actually-- there +are companies right now that + +will go from this level-- +about this level-- + +not this level, but this level. + +And actually, this +is mostly automated. + +So-- to the point where the +only thing that's not automated + +is somebody, not necessary +your op, but maybe a technician + +goes from a robot +and takes a plate + +and puts it in another robot. + +And, like, everything +else is essentially + +automated in DNA assembly + +So those companies have, I +guess, more money than us. + +But eventually, this is the +way DNA assembly will happen. + +So we're collaborating +with some people. + +I'm doing this +with microfluidics. + +The problem with this +robot-- it's $150,000. + +So we can't put it on +everyone's bench yet. + +But we are collaborating +with Lincoln Labs + +to have microfluidic devices +that would cost around + +$3,000 that would do this. + +And we've already demonstrated +with the microfluidic devices + +we can do DNA assembly +of large circuits. + +So this is not that +far away that everyone + +will have microfluidics. + +They program here. + +And they get the DNA assembled. + +And then they realize +it doesn't work. + +But at least there'd +be a lot faster + +to realize that things +don't work, which is good. + +So let's look at how this +compiler, bio compiler, + +works to see that +it's not magic. + +So this is saying +green if not IPTG. + +So IPTG is a small molecule +that we have a sensor for. + +And then the +information gets routed + +to an inverter which +then gets routed + +to activate a green +fluorescent protein. + +So you can take a program +specified like this + +and automatically convert +it into a data flow graph. + +And then the data flow +can be translated-- again, + +this is automated +and this is also + +automated in a +rather simple way-- + +to an actual portions +of the gene circuit. + +So IPTG sensor is +simply this motif. + +So you have a repressor +that responds to IPTG. + +And then it basically +inactivates the repressor. + +So more IPTG, more output. + +And so this is the +IPTG sensor box. + +And this is how +you implement this. + +Not gate-- so I showed you +how a not gate already works. + +So a repressor +represses the output. + +Green fluorescent +protein, you just + +have to have an +activator that activates + +a green fluorescent protein. + +So every data flow +box can automatically + +be converted into a small motif. + +And then what we're +missing is the glue. + +And so the glue is just these +transcriptional activators + +and repressors. + +And so once you put them in +there, then this is a circuit. + +And so this is an automatic +way to go from here to here. + +And it can do rather +complex circuits and logic. + +It can't do everything yet. + +But it can do an +interesting set of things. + +OK, so this is-- again, +it's not completely finished + +in the sense that I +haven't told you what A is. + +I haven't told you what B is. + +So there's a whole +bunch of things + +that still are-- we +have-- either published on + +or still need to be designed. + +But there is, for example, +tool called matchmaker + +which will decide what's +a good protein A, what's + +a good protein B. So things like +that-- so those things already + +exist. + +Anybody look at this and figure +out why this is not perfect? + +So we have an input that +represses a repressor, which + +means that more input, +more activator-- sorry. + +More input, more +protein here, which + +represses B, which +activates GFP. + +So the compiler spits +that out automatically. + +But you may not want to +build this right away. + +Any ideas why? + +I'm sure John would. + +AUDIENCE: So basically, you +have this A can directly repress + +object, so you activate B? + +PROF. + +RON WEISS: So this is what +it-- the first version of B. + +But A represses B. +B activates GFP. + +So why not just hook A up +to regulate GFP directly? + +So this seems like a +non-optimal solution. + +And so you can get the compiler +to figure that out too. + +And so what you do is +you say copy propagation. + +So these are actually just +tools that are available. + +These are mechanisms +that are part + +of normal compilers-- +normal software compilers. + +So they do something called +copy propogation-- means + +that A, if it sees that A-- +the compiler sees A regulates + +B, A represses B, +and B activates A. + +So you can just say, well, let +A just directly regulate this. + +And then the compiler realizes, +well, B doesn't do anything. + +Let's get rid of it. + +And then the promoter +doesn't do anything. + +Let's get rid of it. + +And now the compiler +figured this out. + +And that's using just +basic compiler technology. + +OK, so it's able to do that. + +So the difference in your +life between four and three + +may not be huge. + +But the difference in your +life between 15 and five + +could be the difference +between getting your Ph.D + +or going insane, dropping out, +and then starting a company + +and becoming a billionaire. + +OK, so-- but this is +what the compiler can do. + +And that does make a difference. + +And it may be able to come up +with optimizations that you + +wouldn't be able to really +easily come up with or even + +at all under a reasonable +amount of time. + +So the compiler can do +combinatorial logic. + +It can do state. + +There's also some aspects that +can do spatial things as well. + +And again, this is +available online right now. + +I'm going to-- maybe I +should skip a few things. + +So very quickly, I'll tell you. + +So in the lab-- so +it's nice [INAUDIBLE] + +But if you can't do +anything in the lab, + +then nobody believes +you in the world + +of biology or synthetic biology. + +So we can build big things. + +So here, you can-- there's a +library of promoters and genes + +that we have available. + +And you can decide, +I want to build + +a new circuit has these +promoter gene pairs. + +And within five days, you can +create in the lab that circuit. + +And we've been able +to demonstrate things + +that are 61, 64 Kb that +you build in five days. + +And you build them efficiently. + +And then the undergrads +that we're teaching also + +have been able to-- +again, these are + +people to barely +knew what pipette + +are in the beginning a semester +can now efficiently build + +large circuits. + +So that's become an +easy to use technology. + +And then I mention +this notion that you + +can build this one at a time. + +But this very recent +development where + +you could build 200 +versions of these at a time. + +OK, so you can build them. + +We can then-- again, +I'll skip this part. + +You could build them. + +You can put them +into mammalian cells. + +These things work. + +And we have lots and lots +of parts-- regulatory parts. + +And so let me skip this +particular example. + +So this is-- the two +sentence explanation + +is, OK, you build lots of parts. + +You can build modules. + +And then you put +modules together. + +And guess what? + +This is biology. + +So these modules actually +affect each other, + +potentially in undesirable ways. + +So they can place +things like load. + +So whenever you have a module +that works really well-- maybe + +I will show you one slide. + +But I won't show you +how we solved it. + +But one slide-- so +this is a circuit. + +Any idea what this +circuit might do? + +So this is a regulatory circuit. + +They have an activator +activating itself + +and a repressor that +represses the activator. + +Have you seen this motif? + +So it's a-- some people are +whispering to themselves, + +doing this. + +So this is a +relaxation oscillator. + +When you do it by +yourself, it works great. + +So these are simulations. + +But then if you +connect it-- so it's + +nice to have an +oscillator in a cell, + +again, if you want to +have blinking bacteria + +or mammalian cells +which is, again, fun. + +But then you typically want +to connect it to something. + +So you spent three years +building an oscillator, + +got it to work. + +And now your adviser says, OK, +let's just get a paper on this. + +But before we get +the paper, I want + +you to connect it to +something meaningful. + +Because we want to go for +a high impact journal. + +And then you connect +it to something. + +And you realize that it +doesn't work anymore. + +I think you're really +pissed off at-- you + +will be pissed off +at your adviser. + +I don't know if your adviser +would want to be mean to you. + +But anyways, so that's a +real problem in biology + +or synthetic biology +is that these things + +have impacts on each +other that, first of all, + +are going to be +undesirable but because + +of unique aspects, for +example, of the substrate. + +Now, they're not +as unique as you + +might think because +these load issues also + +come to play in +electronic circuits. + +And so in electronics +circuits, these things + +have been solved decades +ago with these notions + +of load drivers. + +So if you have a module that +has, for example, high fanout + +and it controls many +things, then guess what? + +Those things that it's +trying to control, + +even though the arrows are +pointing one direction, + +they actually have an +upstream effect too. + +So those modules that you think +you're-- the downstream modules + +that you're just controlling, +they actually have an impact + +on the upstream. + +So what you do-- in electronics, +you just build a load driver. + +And it basically +takes care of things. + +So now there's no kind +of parasitic effect. + +And so we've demonstrated +that we can also + +build-- so this is a +notion of retroactivity. + +And this is work with +Domitilla Del Vecchio here. + +And we've demonstrated +that we can-- so I wont' + +go into the details here-- so +we can actually solve this. + +So this is a real problem +even in simple circuits + +experimentally. + +And then it uses this cool +notion of timescale separation + +to solve it. + +But we can take these things +that are highly affected + +to go from black to red +and put a load driver in + +and then it fixes it. + +So this should hopefully lead +to the generation of much more + +predictable circuit +construction targeting + +one of the real challenges in +scaling going from simple toy + +modules to large scale systems. + +So I'll skip that and then move +on to another example-- oh, + +sorry, an example +of an application. + +So in this particular +case-- again, besides + +turning GFP on and off, what +can we do with synthetic biology + +that we can't necessarily do +without synthetic biology? + +And so one of the most +important challenges + +in cancer therapeutics +is specificity-- + +perhaps the most important. + +There are other things +that are important + +such as delivery of +a therapeutic agent. + +But as you improve specificity +that it can actually + +change how you do delivery +of a therapeutic agent. + +So if you have a therapeutic +agent that's much more specific + +and has no side effects, you +can deliver lots and lots more. + +So these things +are highly related. + +So imagine a therapeutic agent +that recognizes something + +on a cell surface and then +says, this is a tumor cell. + +Kill it. + +So there are actually a +lot of efforts ongoing that + +have this particular approach. + +So whether it's small molecules, +whether these vesicles that + +contain various cell surface-- +various molecules that bind + +to cell surface receptors, +a really hot area right + +now is these engineered +killer T cells. + +So this notion that +you can actually + +engineer your immune system +by placing various receptors + +on these killer T +cells which then + +go and then bind tumor cells +by recognizing something + +on the cell surface +and then kill those. + +Sounds great, maybe, depending +on your perspective, or not + +so great, depending +on your perspective. + +So what's happened with +those is they're really + +sometimes great at +eliminating your tumors. + +But then the side effects +can be horrendous. + +And so what happens is that +those cell surface markers + +that exist on the tumor +cells-- guess what? + +They're also present on +healthy cells as well. + +And so the side effects for +those killer T cells approaches + +have been, I mean, just +terrible in various patients. + +So one-- this should +not be a shock. + +One marker is typically not +enough to distinguish a cancer + +cell versus a healthy cell. + +Seems pretty obvious. + +So actually, what they've been +doing with these engineered + +killer T cells is +now just saying, OK, + +has to be this cell +surface receptors, + +but also cannot be this. + +So it's like, and biomarker +one and not-- you know, + +biomarker one, and +not biomarker two. + +OK, so they're starting to +engineer more logic into these, + +more multi-input logic +into these things. + +And so they haven't done +any clinical trials. + +But I saw a couple weeks +ago where they've actually + +made progress in Petri dishes. + +So we recognized this as +an issue several years ago. + +And this is work +with Coby Benson. + +And so really, all the +information that you want + +is actually inside the cell to +make a highly precise decision + +about whether this particular +cell is cancerous or not. + +OK, so the idea is when +the therapeutic agent, + +does the computation +by integrating + +multiple pieces of the +sensory information + +and then decides whether +to express a killer protein + +or not. + +Now, even if this is not +the cure for cancer-- + +can't really +guarantee that, right? + +But even if this is +not, just this notion + +of being able to create multi +input circuits to go into cells + +and analyze in live +cells real time what's + +going on in the cell +with various molecules + +that might be interesting-- that +has applications I would again + +say just about anywhere you +could imagine in biology. + +So one of the +things, for example, + +we're looking at-- I mentioned +this notion of organs + +on a chip or programmed +organs on a chip. + +So one of the things +we're looking at now + +is placing these types +of sensory circuits + +into cells within +this organ on a chip. + +And so the idea would be expose +cells to these drug candidates. + +And then the cells +light up in different + +colors to tell you how +they're responding to it. + +So for example, certain color +green would mean just fine. + +Green with red and +yellow would indicate + +that some apoptotic +pathway is being expressed + +or this drug is affecting +this proliferation + +path or this pathway +or that pathway. + +And so these +mechanisms can tell you + +in real time in +single cells-- also + +specially-- what kind +of impact there is to, + +let's say, the drug +candidate you're looking at. + +So again, this is +something that I + +think would have an impact +today if it was available, + +but realistically +making prototypes + +within the next +year to three years. + +OK, so we started with +looking at HeLa cancer cells + +as an example. + +And so we did some +bioinformatics. + +And we saw that based on +microRNA profiles that + +were available to us, this +would be a bio program that + +would distinguish HeLa cells +from all other cell types. + +And so some of you are +familiar with this way + +of annotating logic. + +Pretty ugly if you're not +used it, but it's simple. + +This just says, these +microRNAs have to be low + +and these microRNAs +have to be high. + +And that's a HeLa cancer cell. + +Because that's the +basic logic in this. + +So it's a rather +simple logic statement. + +What we would argue is +that every cell type + +would have a logic +statement that + +would be true of that cell type +and not true of other cells. + +It's almost by definition. + +There's something different +about that cell than other cell + +types. + +Now, it gets +interesting when you + +start talking about +heterogeneous population. + +So for example, and that's-- +I won't get into details about + +that. + +But there is heterogeneity. + +There's heterogeneity in tumors. + +So the cool thing you can do-- +this is a six input and gate. + +So if you have heterogeneity, +where you can do + +is you can have a six input +and gate with an or operation. + +So you can identify this +sub population of the tumor + +has this microRNA profile. + +And this cell population has +a different microRNA profile. + +And all you have to do is +create a new logic circuit + +and just combine them as like +a cocktail drug as an or gate. + +So this is a really +general approach + +that I think should +be relevant, again, + +for any kind of population. + +And you can also +set the thresholds + +and have all these fun things +that you can do with it. + +So I think the question really +is, is that microRNA expression + +profile sufficiently +small so that it + +can be encoded on a circuit +that you can deliver into cells? + +And can you do it reliably? + +That really is the challenge. + +OK, so the idea is that you +have a therapeutic agent, + +goes into a cell +does the computation, + +and then decides whether to +make a killer protein or not. + +OK, so how does +this actually work? + +So how do we implement an and +gate with inverted inputs? + +OK, so that's one +portion of the circuit. + +So it's actually-- for microRNA, +it's actually pretty easy. + +So what you do is you +put microRNA target sites + +on the gene of interest +or the output gene. + +And so the idea is that the +only way that this gene is being + +expressed, this output +protein is expressed, + +is when this is low and +this is low and this is low. + +So in principle, this +is pretty easy to do. + +OK, so that's how we have +a three input and gate + +with inverted inputs. + +And now we can +add logic to that. + +So now if we want to make sure +that the output is high also + +when this input as high as well. + +And so what we do-- so +remember the first circuit + +that I showed you +was this cascade. + +And the cascade was a bunch +of repressors that would then + +cascade that did the +not not operation. + +So when you think about +the not not operation, + +it doesn't seem like a +very useful operation. + +But this here, the not not +operation, is actually useful. + +So it can convert +a microRNA sensor + +into something that can be +integrated with other sensors + +to create the four +input logic function. + +So this microRNA has +to be high in order + +to repress this +repressor which then + +represses the final output. + +So the only time that the +final output can be high + +is when this is high and +these three are low, OK? + +And then you can continue. + +And you can add another one. + +This is slightly more +complex in the sense + +that now, essentially the +sum of these microRNAs + +has to be high in +order for this branch + +to allow expression here. + +So it's slightly more +complex in the sense + +that it's not just-- +it's like a plus-- again, + +like a plus operation, +which we found + +to be actually the +relevant operation here. + +And so the only +time the output high + +is when this microRNA is +high, combination of these two + +is high, and these are low. + +Anybody see a +potential problem here? + +A potential crosstalk? + +So everybody here +understand the circuit? + +Raise your hand if you actually +understand the circuit. + +OK, that's not a lot of people. + +OK, maybe I should +go back for a second. + +Everybody-- raise your hand +if you understand this. + +OK, so if microRNA is +high, they repress-- + +they result in +degradation of the RNA. + +So all of these have to be low +in order for this to be high. + +OK, now if we had +this, this RNA-- + +let's focus just on +this maybe to simplify. + +So this microRNA +represses-- this + +is a repressor which +represses this, OK? + +So if this microRNA is low, +then this repressor as high. + +And as a result of +that, this repressor + +represses this +promoter regardless. + +So it doesn't matter +what these are. + +If this is low, this +repressor is high. + +And then there's no way that +this output can be high. + +Now, if this is +microRNA is high, + +then this becomes low, allowing +this to potentially be high. + +Doesn't guarantee it, but +it has a potential of doing. + +OK, now raise your hand +if you understand that. + +OK, more. + +OK, cool. + +That's progress. + +By the way, this was +not a trivial circuit. + +There's a lot of +connections here. + +And then we connect the same-- +now we have the same repressor. + +So this microRNA-- +these set of microRNAs + +repress the same repressor +which is now repressing this. + +So why is it the +case that you need-- + +let's just assume +this is one microRNA, + +this is another micro. + +Why do you need both microRNAs +to allow high output? + +And then I will not +let anyone leave + +until you answer the question. + +And I can sit down. + +So why-- and then +we'll stop there. + +And everybody will believe +me that the cure for cancer, + +you got it figure it out. + +Otherwise-- so +there's-- oh, thank you. + +Letting-- you will be the hero. + +AUDIENCE: So if the +microRNAs are not present, + +then you're going to get an +expression of Lacks E. So-- + +PROF. + +RON WEISS: Lack I. + +AUDIENCE: Yeah, like eyes. + +So only if both the microRNAs +are high and present + +do you repress both +of the lack I's + +which then allow for +the expression of the-- + +PROF. + +RON WEISS: Exactly. + +And what happens if +one of them is present + +and the other one is not? + +So if this microRNA is +present and this one is not? + +AUDIENCE: Then the lack +I still gets expressed + +because the other one +is still not repressed. + +PROF. + +RON WEISS: Exactly. + +So the only way that +you can actually + +have no expression of lack +I is when this is high + +and this is high. + +So this is essentially +like a two input and gate. + +These two have to be high +to allow this promoter + +to potentially be high. + +And in the other three logic +cases where one of those + +is low, lack I is +expressed and hence + +does not allow the output +protein to be expressed, OK? + +Yeah. + +AUDIENCE: So why do +you have the partition? + +All three are +acting the same way. + +PROF. + +RON WEISS: Ah, great question. + +So what happens if microRNA +21, 17, and 38 were all here? + +So that's a great question. + +So that's a question, right? + +So if you put microRNA +21 here, 17, and 38? + +What is the logic function here? + +Yeah. + +AUDIENCE: Then you +only need one of them + +in order to degrade the RNA. + +And then you won't +get the same logic. + +PROF. + +RON WEISS: Great. + +So then it becomes +essentially an or. + +This will be an or +operation of the microRNAs + +where what we want is an and +operation on the microRNA. + +So that by having +two separate paths + +that have the same repressor +where they converge + +on the same repressor, we +achieve the and operation. + +Where we have them on +the same repressor, + +they do the or operation. + +That's a great question. + +OK, so this works. + +And maybe I'll say thank you. + +I'll stop there. \ No newline at end of file diff --git a/kNmiTTKiYd4.txt b/kNmiTTKiYd4.txt new file mode 100644 index 0000000000000000000000000000000000000000..f47c8391dcb030d1929f0fbde398916343f0c7aa --- /dev/null +++ b/kNmiTTKiYd4.txt @@ -0,0 +1,2140 @@ +[MUSIC PLAYING] + +PROFESSOR: Last time, we took a +look at an explicit control + +evaluator for Lisp, and that +bridged the gap between all + +these high-level languages +like Lisp and the query + +language and all of that stuff, +bridged the gap between + +that and a conventional +register machine. + +And in fact, you can think of +the explicit control evaluator + +either as, say, the code for a +Lisp interpreter if you wanted + +to implement it in the assembly +language of some + +conventional register transfer +machine, or, if you like, you + +can think of it as the microcode +of some machine + +that's going to be specially +designed to run Lisp. + +In either case, what we're +doing is we're taking a + +machine that speaks some +low-level language, and we're + +raising the machine to a +high-level language like Lisp + +by writing an interpreter. + +So for instance, here, +conceptually, is a special + +purpose machine for computing +factorials. + +It takes in five and +puts out 120. + +And what this special purpose +machine is is actually a Lisp + +interpreter that's configured +itself to run factorials, + +because you fit into +it a description of + +the factorial machine. + +So that's what an +interpreter is. + +It configures itself to emulate +a machine whose + +description you read in. + +Now, inside the Lisp +interpreter, what's that? + +Well, that might be your general +register language + +interpreter that configures +itself to behave like a Lisp + +interpreter, because you +put in a whole bunch of + +instructions in register +language. + +This is the explicit +control evaluator. + +And then it also has some sort +of library, a library of + +primitive operators and Lisp +operations and all sorts of + +things like that. + +That's the general strategy +of interpretation. + +And the point is, what we're +doing is we're writing an + +interpreter to raise the machine +to the level of the + +programs that we +want to write. + +Well, there's another strategy, +a different one, + +which is compilation. + +Compilation's a little +bit different. + +Here--here we might have +produced a special purpose + +machine for, for computing +factorials, starting with some + +sort of machine that speaks +register language, except + +we're going to do a different +strategy. + +We take our factorial program. + +We use that as the source +code into a compiler. + +What the compiler will do is +translate that factorial + +program into some register +machine language. + +And this will now be not the +explicit control evaluator for + +Lisp, this will be some +register language for + +computing factorials. + +So this is the translation +of that. + +That will go into some sort of +loader which will combine this + +code with code selected from the +library to do things like + +primitive multiplication. + +And then we'll produce a load +module which configures the + +register language machine +to be a special + +purpose factorial machine. + +So that's a, that's a +different strategy. + +In interpretation, we're raising +the machine to the + +level of our language, +like Lisp. + +In compilation, we're taking our +program and lowering it to + +the language that's spoken +by the machine. + +Well, how do these two +strategies compare? + +The compiler can produce code +that will execute more + +efficiently. + +The essential reason for that is +that if you think about the + +register operations that are +running, the interpreter has + +to produce register operations +which, in principle, are going + +to be general enough to execute +any Lisp procedure. + +Whereas the compiler only has +to worry about producing a + +special bunch of register +operations for, for doing the + +particular Lisp procedure +that you've compiled. + +Or another way to say that is +that the interpreter is a + +general purpose simulator, that +when you read in a Lisp + +procedure, then those can +simulate the program described + +by that, by that procedure. + +So the interpreter is worrying +about making a general purpose + +simulator, whereas the compiler, +in effect, is + +configuring the thing to +be the machine that the + +interpreter would have +been simulating. + +So the compiler can be faster. + +On the other hand, the +interpreter is a nicer + +environment for debugging. + +And the reason for that is that +we've got the source code + +actually there. + +We're interpreting it. + +That's what we're +working with. + +And we also have the +library around. + +See, the interpreter--the +library sitting there is part + +of the interpreter. + +The compiler only pulls out from +the library what it needs + +to run the program. + +So if you're in the middle of +debugging, and you might like + +to write a little extra program +to examine some run + +time data structure or to +produce some computation that + +you didn't think of when you +wrote the program, the + +interpreter can do that +perfectly well, whereas the + +compiler can't. + +So there are sort of dual, +dual advantages. + +The compiler will produce code +that executes faster. + +The interpreter is a better +environment for debugging. + +And most Lisp systems end up +having both, end up being + +configured so you have an +interpreter that you use when + +you're developing your code. + +Then you can speed it +up by compiling. + +And very often, you can arrange +that compiled code and + +interpreted code can +call each other. + +We'll see how to do that. + +That's not hard. + +In fact, the way we'll-- + +in the compiler we're going to +make, the way we'll arrange + +for compiled coding and +interpreted code to call, to + +call each other, is that we'll +have the compiler use exactly + +the same register conventions +as the interpreter. + +Well, the idea of a compiler is +very much like the idea of + +an interpreter or evaluator. + +It's the same thing. + +See, the evaluator walks over +the code and performs some + +register operations. + +That's what we did yesterday. + +Well, the compiler essentially +would like to walk over the + +code and produce the register +operations that the evaluator + +would have done were it +evaluating the thing. + +And that gives us a model +for how to implement a + +zeroth-order compiler, a +very bad compiler but + +essentially a compiler. + +A model for doing that is you +just take the evaluator, you + +run it over the code, but +instead of executing the + +actual operations, you +just save them away. + +And that's your compiled code. + +So let me give you an +example of that. + +Suppose we're going to +compile--suppose we want to + +compile the expression f of x. + +So let's assume that we've got +f of x in the x register and + +something in the environment +register. + +And now imagine starting +up the evaluator. + +Well, it looks at the expression +and it sees that + +it's an application. + +And it branches to a place in +the evaluator code we saw + +called ev-application. + +And then it begins. + +It stores away the operands and +unev, and then it's going + +to put the operator in exp, +and it's going to go + +recursively evaluate it. + +That's the process that +we walk through. + +And if you start looking at +the code, you start seeing + +some register operations. + +You see assign to unev the +operands, assign to exp the + +operator, save the environment, +generate + +that, and so on. + +Well, if we look on the overhead +here, we can see, we + +can see those operations +starting to be produced. + +Here's sort of the first real +operation that the evaluator + +would have done. + +It pulls the operands out of the +exp register and assigns + +it to unev. And then it assigns +something to the + +expression register, and it +saves continue, and it saves + +env. + +And all I'm doing here is +writing down the register + +assignments that the evaluator +would have done in + +executing that code. + +And can zoom out a little bit. + +Altogether, there are about +19 operations there. + +And this is the--this will be +the piece of code up until the + +point where the evaluator +branches off to + +apply-dispatch. + +And in fact, in this compiler, +we're not going to worry about + +apply-dispatch at all. + +We're going to have +everything--we're going to + +have both interpreted code +and compiled code. + +Always evaluate procedures, +always apply procedures by + +going to apply-dispatch. + +That will easily allow +interpreted code and compiled + +code to call each other. + +Well, in principle, that's +all we need to do. + +You just run the evaluator. + +So the compiler's a lot +like the evaluator. + +You run it, except it stashes +away these operations instead + +of actually executing them. + +Well, that's not, that's +not quite true. + +There's only one little +lie in that. + +What you have to worry about is +if you have a, a predicate. + +If you have some kind of test +you want to do, obviously, at + +the point when you're compiling +it, you don't know + +which branch of these--of a +conditional like this you're + +going to do. + +So you can't say which one the +evaluator would have done. + +So all you do there +is very simple. + +You compile both branches. + +So you compile a structure +that looks like this. + +That'll compile into something +that says, the code, the code + +for P. And it puts its results +in, say, the val register. + +So you walk the interpreter over +the predicate and make + +sure that the result would +go into the val register. + +And then you compile an +instruction that says, branch + +if, if val is true, to a place +we'll call label one. + +Then we, we will put the +code for B to walk the + +interpreter--walk the +interpreter over B. And then + +go to put in an instruction +that says, go to the next + +thing, whatever, whatever was +supposed to happen after this + +thing was done. + +You put in that instruction. + +And here you put label one. + +And here you put the +code for A. And you + +put go to next thing. + +So that's how you treat +a conditional. + +You generate a little +block like that. + +And other than that, this +zeroth-order compiler is the + +same as the evaluator. + +It's just stashing away the +instructions instead of + +executing them. + +That seems pretty simple, +but we've gained + +something by that. + +See, already that's +going to be more + +efficient than the evaluator. + +Because, if you watch the +evaluator run, it's not only + +generating the register +operations we wrote down, it's + +also doing things to decide +which ones to generate. + +So the very first thing it does, +say, here for instance, + +is go do some tests and decide +that this is an application, + +and then branch off to the +place that, that handles + +applications. + +In other words, what the +evaluator's doing is + +simultaneously analyzing the +code to see what to do, and + +running these operations. + +And when you-- + +if you run the evaluator a +million times, that analysis + +phase happens a million times, +whereas in the compiler, it's + +happened once, and then you +just have the register + +operations themselves. + +Ok, that's a, a zeroth-order +compiler, but it is a + +wretched, wretched compiler. + +It's really dumb. + +Let's--let's go back and, and +look at this overhead. + +So look at look at some +of the operations + +this thing is doing. + +We're supposedly looking +at the operations and + +interpreting f of x. + +Now, look here what +it's doing. + +For example, here it +assigns to exp the + +operator in fetch of exp. + +But see, there's no reason to +do that, because this is-- + +the compiler knows that the +operator, fetch of exp, is f + +right here. + +So there's no reason why this +instruction should say that. + +It should say, we'll +assign to exp, f. + +Or in fact, you don't +need exp at all. + +There's no reason it should +have exp at all. + +What, what did exp +get used for? + +Well, if we come down here, +we're going to assign to val, + +look up the stuff in exp +in the environment. + +So what we really should do is +get rid of the exp register + +altogether, and just change +this instruction to say, + +assign to val, look up the +variable value of the symbol f + +in the environment. + +Similarly, back up here, we +don't need unev at all, + +because we know what the +operands of fetch of exp are + +for this piece of code. + +It's the, it's the list x. + +So in some sense, you don't +want unev and exp at all. + +See, what they really are in +some sense, those aren't + +registers of the actual machine + +that's supposed to run. + +Those are registers that have to +do with arranging the thing + +that can simulate +that machine. + +So they're always going to hold +expressions which, from + +the compiler's point of view, +are just constants, so can be + +put right into the code. + +So you can forget about all the +operations worrying about + +exp and unev and just +use those constants. + +Similarly, again, if we go, go +back and look here, there are + +things like assign to +continue eval-args. + +Now, that has nothing +to do with anything. + +That was just the evaluator +keeping track of where it + +should go next, to evaluate the +arguments in some, in some + +application. + +But of course, that's irrelevant +to the compiler, + +because you-- + +the analysis phase will have +already done that. + +So this is completely +irrelevant. + +So a lot of these, these +assignments to continue have + +not to do where the running +machine is supposed to + +continue in keeping track +of its state. + +It has to, to do with where the +evaluator analysis should + +continue, and those are +completely irrelevant. + +So we can get rid of them. + +Ok, well, if we, if we simply +do that, make those kinds of + +optimizations, get rid, get rid +of worrying about exp and + +unev, and get rid of these +irrelevant register + +assignments to continue, then we +can take this literal code, + +these sort of 19 instructions +that the, that the evaluator + +would have done, and +then replace them. + +Let's look at the, +at the slide. + +Replace them by--we get rid +of about half of them. + +And again, this is just sort +of filtering what the + +evaluator would have done +by getting rid of + +the irrelevant stuff. + +And you see, for instance, here +the--where the evaluator + +said, assign val, look up +variable value, fetch of exp, + +here we have put in +the constant f. + +Here we've put in +the constant x. + +So there's a, there's a little +better compiler. + +It's still pretty dumb. + +It's still doing a lot +of dumb things. + +Again, if we go look at the +slide again, look at the very + +beginning here, we see a save +the environment, assign + +something to the val register, +and restore the environment. + +Where'd that come from? + +That came from the evaluator +back here saying, oh, I'm in + +the middle of evaluating +an application. + +So I'm going to recursively +call eval dispatch. + +So I'd better save the thing I'm +going to need later, which + +is the environment. + +This was the result +of recursively + +calling eval dispatch. + +It was evaluating the symbol +f in that case. + +Then it came back from eval +dispatch, restored the + +environment. + +But in fact, the actual thing +it ended up doing in the + +evaluation is not going to hurt +the environment at all. + +So there's no reason to be +saving the environment and + +restoring the environment +here. + +Similarly, here I'm saving the +argument list. That's a piece + +of the argument evaluation +loop, saving the argument + +list, and here you restore it. + +But the actual thing that you +ended up doing didn't trash + +the argument list. So there +was no reason to save it. + +So another way to say, another +way to say that is that the, + +the evaluator has to be +maximally pessimistic, because + +as far from its point of view +it's just going off to + +evaluate something. + +So it better save what it's +going to need later. + +But once you've done the +analysis, the compiler is in a + +position to say, well, what +actually did I need to save? + +And doesn't need to do any-- +it doesn't need to be as + +careful as the evaluator, +because it knows what it + +actually needs. + +Well, in any case, if we do that +and eliminate all those + +redundant saves and restores, +then we can + +get it down to this. + +And you see there are actually +only three instructions that + +we actually need, down from the +initial 11 or so, or the + +initial 20 or so in +the original one. + +And that's just saying, of those +register operations, + +which ones did we +actually need? + +Let me just sort of summarize +that in another way, just to + +show you in a little +better picture. + +Here's a picture of starting-- + +This is looking at all the +saves and restores. + +So here's the expression, f +of x, and then this traces + +through, on the bottom here, +the various places in the + +evaluator that were passed when +the evaluation happened. + +And then here, here +you see arrows. + +Arrow down means +register saved. + +So the first thing that +happened is the + +environment got saved. + +And over here, the environment +got restored. + +And these-- so there are all the +pairs of stack operations. + +Now, if you go ahead and say, +well, let's remember that we + +don't--that unev, for instance, +is a completely + +useless register. + +And if we use the constant +structure of the code, well, + +we don't need, we don't need +to save unev. We don't need + +unev at all. + +And then, depending on how we +set up the discipline of + +the--of calling other things +that apply, we may or may not + +need to save continue. + +That's the first step I did. + +And then we can look and see +what's actually, what's + +actually needed. + +See, we don't-- didn't really +need to save env or + +cross-evaluating f, because +it wouldn't, it + +wouldn't trash it. + +So if we take advantage of that, +and see the evaluation + +of f here, doesn't really need +to worry about, about hurting + +env. And similarly, the +evaluation of x here, when the + +evaluator did that it said, oh, +I'd better preserve the + +function register around that, +because I might need it later. + +And I better preserve +the argument list. + +Whereas the compiler is now in +a position to know, well, we + +didn't really need +to save-- to do + +those saves and restores. + +So in fact, all of the stack +operations done by the + +evaluator turned out to be +unnecessary or overly + +pessimistic. + +And the compiler is in a +position to know that. + +Well that's the basic idea. + +We take the evaluator, we +eliminate the things that you + +don't need, that in some sense +have nothing to do with the + +compiler at all, just the +evaluator, and then you see + +which stack operations +are unnecessary. + +That's the basic structure of +the compiler that's described + +in the book. + +Let me just show you +how that examples a + +little bit too simple. + +To see how you, how you actually +save a lot, let's + +look at a little bit more +complicated expression. + +F of G of X and 1. + +And I'm not going to go +through all the code. + +There's a, there's a +fair pile of it. + +I think there are, there are +something like 16 pairs of + +register saves and restores +as the evaluator + +walks through that. + +Here's a diagram of them. + +Let's see. + +You see what's going on. + +You start out by--the evaluator +says, oh, I'm about + +to do an application. + +I'll preserve the environment. + +I'll restore it here. + +Then I'm about to do +the first operand. + +Here it recursively goes +to the evaluator. + +The evaluator says, oh, this is +an application, I'll save + +the environment, do the operator +of that combination, + +restore it here. + +This save--this restore matches +that save. And so on. + +There's unev here, which turns +out to be completely + +unnecessary, continues getting +bumped around here. + +The function register is +getting, getting saved across + +the first operands, across +the operands. + +All sorts of things +are going on. + +But if you say, well, what of +those really were the business + +of the compiler as opposed to +the evaluator, you get rid of + +a whole bunch. + +And then on top of that, if +you say things like, the + +evaluation of F doesn't hurt the +environment register, or + +simply looking up the symbol X, +you don't have to protect + +the function register +against that. + +So you come down to just +a couple of, a + +couple of pairs here. + +And still, you can do +a little better. + +Look what's going on here with +the environment register. + +The environment register comes +along and says, oh, here's a + +combination. + +This evaluator, by the way, +doesn't know anything about G. + +So here it says, so it says, +I'd better save the + +environment register, because +evaluating G might be some + +arbitrary piece of code that +would trash it, and I'm going + +to need it later, after +this argument, for + +doing the second argument. + +So that's why this one didn't go +away, because the compiler + +made no assumptions about +what G would do. + +On the other hand, if you look +at what the second argument + +is, that's just looking +up one. + +That doesn't need this +environment register. + +So there's no reason +to save it. + +So in fact, you can get +rid of that one, too. + +And from this whole pile of, of +register operations, if you + +simply do a little bit of +reasoning like that, you get + +down to, I think, just two pairs +of saves and restores. + +And those, in fact, could go +away further if you, if you + +knew something about G. + +So again, the general idea is +that the reason the compiler + +can be better is that the +interpreter doesn't know what + +it's about to encounter. + +It has to be maximally +pessimistic in saving things + +to protect itself. + +The compiler only has +to deal with what + +actually had to be saved. + +And there are two reasons +that something might + +not have to be saved. + +One is that what you're +protecting it against, in + +fact, didn't trash the register, +like it was just a + +variable look-up. + +And the other one is, that the +thing that you were saving it + +for might turn out not +to actually need it. + +So those are the two basic +pieces of knowledge that the + +compiler can take advantage +of in making + +the code more efficient. + +Let's break for questions. + +AUDIENCE: You kept saying that +the uneval register, unev + +register didn't need +to be used at all. + +Does that mean that you +could just map a + +six-register machine? + +Or is that, in this particular +example, it + +didn't need to be used? + +PROFESSOR: For the compiler, +you could generate code for + +the six-register, five, right? + +Because that exp +goes away also. + +Assuming--yeah, you can get +rid of both exp and unev, + +because, see, those are data +structures of the evaluator. + +Those are all things that would +be constants from the + +point of view of the compiler. + +The only thing is this +particular compiler is set up + +so that interpreted code and +compiled code can coexist. + +So the way to think about it is, +is maybe you build a chip + +which is the evaluator, and what +the compiler might do is + +generate code for that chip. + +It just wouldn't use two +of the registers. + +All right, let's take a break. + +[MUSIC PLAYING] + +We just looked at what the +compiler is supposed to do. + +Now let's very briefly look +at how, how this gets + +accomplished. + +And I'm going to give +no details. + +There's, there's a giant pile of +code in the book that gives + +all the details. + +But what I want to do is +just show you the, the + +essential idea here. + +Worry about the details +some other time. + +Let's imagine that we're +compiling an expression that + +looks like there's some +operator, and + +there are two arguments. + +Now, the-- + +what's the code that the +compiler should generate? + +Well, first of all, it should +recursively go off and compile + +the operator. + +So it says, I'll compile +the operator. + +And where I'm going to need that +is to be in the function + +register, eventually. + +So I'll compile some +instructions that will compile + +the operator and end up +with the result in + +the function register. + +The next thing it's going to do, +another piece is to say, + +well, I have to compile +the first argument. + +So it calls itself +recursively. + +And let's say the result +will go into val. + +And then what it's going to need +to do is start setting up + +the argument list. So it'll say, +assign to argl cons of + +fetch-- so it generates this +literal instruction-- + +fetch of val onto empty list. + +However, it might +have to work-- + +when it gets here, it's going +to need the environment. + +It's going to need whatever +environment was here in order + +to do this evaluation of +the first argument. + +So it has to ensure that the +compilation of this operand, + +or it has to protect the +function register against + +whatever might happen in the +compilation of this operand. + +So it puts a note here and says, +oh, this piece should be + +done preserving the environment +register. + +Similarly, here, after it gets +done compiling the first + +operand, it's going to say, +I better compile-- + +I'm going to need to know +the environment + +for the second operand. + +So it puts a little note here, +saying, yeah, this is also + +done preserving env. Now it goes +on and says, well, the + +next chunk of code is the one +that's going to compile the + +second argument. + +And let's say it'll compile +it with a targeted to + +val, as they say. + +And then it'll generate the +literal instruction, building + +up the argument list. So it'll +say, assign to argl cons of + +the new value it just got onto +the old argument list. + +However, in order to have the +old argument list, it better + +have arranged that the argument +list didn't get + +trashed by whatever +happened in here. + +So it puts a little note here +and says, oh, this has to be + +done preserving argl. + +Now it's got the argument +list set up. + +And it's all ready to go +to apply dispatch. + +It generates this literal +instruction. + +Because now it's got the +arguments in argl and the + +operator in fun, but wait, it's +only got the operator in + +fun if it had ensured that +this block of code didn't + +trash what was in the +function register. + +So it puts a little note here +and says, oh, yes, all this + +stuff here had better +be done preserving + +the function register. + +So that's the little--so when +it starts ticking--so + +basically, what the compiler +does is append a whole bunch + +of code sequences. + +See, what it's got in it is +little primitive pieces of + +things, like how to look up +a symbol, how to do a + +conditional. + +Those are all little +pieces of things. + +And then it appends them +together in this sort of + +discipline. + +So the basic means of combining +things is to append + +two code sequences. + +That's what's going on here. + +And it's a little bit tricky. + +The idea is that it appends +two code sequences, taking + +care to preserve a register. + +So the actual append operation +looks like this. + +What it wants to +do is say, if-- + +here's what it means to append +two code sequences. + +So if sequence one +needs register-- + +I should change this. + +Append sequence one +to sequence two, + +preserving some register. + +Let me say, and. + +So it's clear that sequence +one comes first. + +So if sequence two needs the +register and sequence one + +modifies the register, then +the instructions that the + +compiler spits out are, +save the register. + +Here's the code. + +You generate this code. + +Save the register, and then you +put out the recursively + +compiled stuff for +sequence one. + +And then you restore +the register. + +And then you put out the +recursively compiled stuff for + +sequence two. + +That's in the case where +you need to do it. + +Sequence two actually needs the +register, and sequence one + +actually clobbers it. + +So that's sort of if. + +Otherwise, all you spit out is +sequence one followed by + +sequence two. + +So that's the basic operation +for sticking together these + +bits of code fragments, +these bits of + +instructions into a sequence. + +And you see, from this point +of view, the difference + +between the interpreter and the +compiler, in some sense, + +is that where the compiler has +these preserving notes, and + +says, maybe I'll actually +generate the saves and + +restores and maybe I won't, +the interpreter being + +maximally pessimistic always has +a save and restore here. + +That's the essential +difference. + +Well, in order to do this, of +course, the compiler needs + +some theory of what code +sequences need + +and modifier registers. + +So the tiny little fragments +that you put in, like the + +basic primitive code fragments, +say, what are the + +operations that you do when +you look up a variable? + +What are the sequence of things +that you do when you + +compile a constant or +apply a function? + +Those have little notations in +there about what they need and + +what they modify. + +So the bottom-level +data structures-- + +Well, I'll say this. + +A code sequence to the compiler +looks like this. + +It has the actual sequence +of instructions. + +And then, along with +it, there's the set + +of registers modified. + +And then there's the set +of registers needed. + +So that's the information the +compiler has that it draws on + +in order to be able to +do this operation. + +And where do those come from? + +Well, those come from, you might +expect, for the very + +primitive ones, we're going +to put them in by hand. + +And then, when we combine two +sequences, we'll figure out + +what these things should be. + +So for example, a very primitive +one, let's see. + +How about doing a register +assignment. + +So a primitive sequence might +say, oh, it's code fragment. + +Its code instruction is assigned +to R1, fetch of R2. + +So this is an example. + +That might be an example of a +sequence of instructions. + +And along with that, it'll +say, oh, what I need to + +remember is that that modifies +R1, and then it needs R2. + +So when you're first building +this compiler, you put in + +little fragments of +stuff like that. + +And now, when it combines two +sequences, if I'm going to + +combine, let's say, sequence +one, that modifies a bunch of + +registers M1, and needs a +bunch of registers N1. + +And I'm going to combine +that with sequence two. + +That modifies a bunch of +registers M2, and needs a + +bunch of registers N2. + +Then, well, we can +reason it out. + +The new code fragment, +sequence one, and-- + +followed by sequence two, well, + +what's it going to modify? + +The things that it will modify +are the things that are + +modified either by sequence +one or sequence two. + +So the union of these +two sets are what + +the new thing modifies. + +And then you say, well, what is +this--what registers is it + +going to need? + +It's going to need the things +that are, first of all, needed + +by sequence one. + +So what it needs is +sequence one. + +And then, well, not quite all of +the ones that are needed by + +sequence one. + +What it needs are the ones that +are needed by sequence + +two that have not been set +up by sequence one. + +So it's sort of the union of the +things that sequence two + +needs minus the ones that +sequence one modifies. + +Because it worries about +setting them up. + +So there's the basic structure +of the compiler. + +The way you do register +optimizations is you have some + +strategies for what needs +to be preserved. + +That depends on a +data structure. + +Well, it depends on the +operation of what it means to + +put things together. + +Preserving something, that +depends on knowing what + +registers are needed +and modified + +by these code fragments. + +That depends on having little +data structures, which say, a + +code sequence is the actual +instructions, what they modify + +and what they need. + +That comes from, at +the primitive + +level, building it in. + +At the primitive level, it's +going to be completely obvious + +what something needs +and modifies. + +Plus, this particular way that +says, when I build up bigger + +ones, here's how I generate +the new set of registers + +modified and the new set +of registers needed. + +And that's the whole-- + +well, I shouldn't say that's +the whole thing. + +That's the whole thing except +for about 30 pages of details + +in the book. + +But it is a perfectly usable +rudimentary compiler. + +Let me kind of show +you what it does. + +Suppose we start out with +recursive factorial. + +And these slides are going to +be much too small to read. + +I just want to flash through +the code and show you about + +how much it is. + +That starts out with--here's a +first block of it, where it + +compiles a procedure entry and +does a bunch of assignments. + +And this thing is basically up +through the part where it sets + +up to do the predicate +and test whether + +the predicate's true. + +The second part is what +results from-- + +in the recursive call to +fact of n minus one. + +And this last part is coming +back from that and then taking + +care of the constant case. + +So that's about how +much code it + +would produce for factorial. + +We could make this compiler +much, much better, of course. + +The main way we could make +it better is to allow the + +compiler to make any assumptions +at all about what + +happens when you call +a procedure. + +So this compiler, for instance, +doesn't even know, + +say, that multiplication +is something that + +could be coded in line. + +Instead, it sets up this +whole mechanism. + +It goes to apply-dispatch. + +That's a tremendous waste, +because what you do every time + +you go to apply-dispatch is +you have to concept this + +argument list, because it's +a very general thing + +you're going to. + +In any real compiler, of course, +you're going to have + +registers for holding +arguments. + +And you're going to start +preserving and saving the way + +you use those registers +similar to the + +same strategy here. + +So that's probably the very main +way that this particular + +compiler in the book +could be fixed. + +There are other things like +looking up variable values and + +making more efficient primitive +operations and all + +sorts of things. + +Essentially, a good Lisp +compiler can absorb an + +arbitrary amount of effort. + +And probably one of the reasons +that Lisp is slow with + +compared to languages like +FORTRAN is that, if you look + +over history at the amount of +effort that's gone into + +building Lisp compilers, it's +nowhere near the amount of + +effort that's gone into +FORTRAN compilers. + +And maybe that's something that +will change over the next + +couple of years. + +OK, let's break. + +Questions? + +AUDIENCE: One of the very +first classes-- + +I don't know if it was during +class or after class- you + +showed me the, say, addition has +a primitive that we don't + +see, and-percent add or +something like that. + +Is that because, if you're doing +inline code you'd want + +to just do it for two +operators, operands? + +But if you had more operands, +you'd want to + +do something special? + +PROFESSOR: Yeah, you're looking +in the actual scheme + +implementation. + +There's a plus, and a plus +is some operator. + +And then if you go look inside +the code for plus, you see + +something called-- + +I forget-- and-percent plus +or something like that. + +And what's going on there is +that particular kind of + +optimization. + +Because, see, general +plus takes an + +arbitrary number of arguments. + +So the most general plus says, +oh, if I have an argument + +list, I'd better cons it up in +some list and then figure out + +how many there were or +something like that. + +That's terribly inefficient, +especially since most of the + +time you're probably +adding two numbers. + +You don't want to really have to +cons this argument list. So + +what you'd like to do is build +the code for plus with a bunch + +of entries. + +So most of what it's +doing is the same. + +However, there might be a +special entry that you'd go to + +if you knew there were +only two arguments. + +And those you'll put +in registers. + +They won't be in an argument +list and you won't have to + +[UNINTELLIGIBLE]. + +That's how a lot of +these things work. + +OK, let's take a break. + +[MUSIC PLAYING] \ No newline at end of file diff --git a/kYgBLGwuBpw.txt b/kYgBLGwuBpw.txt new file mode 100644 index 0000000000000000000000000000000000000000..0fdd24d4261237a2ac5317be666bda7de3a8a6cc --- /dev/null +++ b/kYgBLGwuBpw.txt @@ -0,0 +1,1915 @@ +PROFESSOR: All right. + +The end of this lecture +generated so much excitement + +that we've continued on into the +start of the next segment. + +So I think we'd better begin. + +What I told you, as several +people were clever enough to + +observe, that the number of +planes between the origin and + +intercept plane is equal to A +times B times C, where the + +intercept is A T1 out plus +B T2 out equals C T3 out. + +That is true only if the +numbers A, B, and C are + +mutually prime. + +If it's something like 4, +2, 1, you won't get + +that number of planes. + +You'll get a submultiple. + +And the reason for that is that +some of the planes, when + +you generate them by these three +different translations + +in different directions, some +of them are mapped on top of + +existing planes. + +And I'm not going to attempt to +prove this, but let me just + +tell you the result, that if +A and B contain some common + +factor, p, and B and C contain +some common factor, q, and in + +the worst possible case, A and C +contains some common factor, + +r, then the number of intervals +is equal to A times + +B times C divided by +p times q times r. + +And probably the best way to +show that is let you show, on + +a problem set in the very near +future, to actually map out + +the planes in the +two-dimensional situation, for + +a and b that are mutually prime, +and then do the same + +thing for a and b that contain +some common factor. + +So this is the so-called +Miller indices, the + +Miller-Bravais indices, and +everybody hears about them, + +but it is not at all clear why +one takes this very indirect + +and non-intuitive way +of defining the + +orientation of a plane. + +And the reason for this, +ultimately, is that in x-ray + +diffraction, you want to +integrate up the scattering of + +all atoms in a crystal. + +So you want to integrate over +a plane that contains the + +atoms, and this locus has a +convenient form only if you + +choose these indices to find the +orientation of the plane. + +And what comes out of this, as +I said to a couple of people + +during intermission, is that the +amplitude of the scattered + +wave has some summation +over all of the atoms. + +And in that phase of that ray, +that is e to the plus 2 pi i, + +hx plus ky plus lz. + +Very, very simple form. + +And it has that form only +because the locus, the way + +this plane is defined was done +very, very carefully. + +So it's something beyond just +simple geometry that forms a + +reason for it. + +Let me say a couple more things +in general about the + +Miller-Bravais indices. + +They are very, very intuitive, +counter-intuitive. + +Let's suppose that this is a, +and this is b, and this is c. + +And I put down here, again, the +equations of the entire + +set of planes in the stack. + +And let's look at the first +planes and ask what the + +intercepts are. + +The intercepts on x, y, and z +are going to be 1 over h on x, + +1 over k on y, and +1 over l times z. + +So the first plane from the +origin is going to be 1 over h + +of the a translation, 1 over k +of the b translation, and 1 + +over l of the c translation. + +So this gives us one way +of determining, given a + +particular rational plane, show +it relative to the three + +translations. + +From the first plane from the +origin, h is going to be 1 + +over the intercept on T1. + +I'll call it a, which is +what we usually do. + +k is going to be 1 over the +intercept on b, and l is going + +to be 1 over the intercept +on c for the first + +plane from the origin. + +So if you have a drawing of the +set of planes relative to + +the translation, such as the +one that I obliterated from + +just a moment ago, reciprocals +of the intercepts of the first + +plane from the origin give you +h, k, and l very easily. + +The thing that is +counter-intuitive is that, if + +you look out of context at the +three indices, h, k, and l, + +you have the feeling that as l +gets larger, the intercept of + +the plane on c should gradually +creep up from here, + +to here, to here, and so +on, as l gets larger. + +Actually, the reverse is true. + +As l increases, the intercept on +c gets smaller and smaller + +and smaller and smaller, until +finally, when l is infinity, + +the intercept is 0. + +So it's counter-intuitive. + +The intercept on the axis gets +larger as the Miller index + +gets larger. + +Let me give you a proprietary +Uncle Bernie's secret method + +for determining Miller indices +without stress and strain. + +This works every time. + +Find the intercepts +of any plane. + +And we know from these +equations what those + +are going to be. + +For the nth plane, the +intercepts are going to be n + +over h, n over k on b, +and n over l on c. + +Take the reciprocals. + +And the reciprocals are going +to be h over n, k over + +n, and l over n. + +And then find whatever integer, +n, you must multiply + +those reciprocals by in order +to convert them to mutually + +prime intercepts, and you've +got the Miller indices in a + +no-brainer, automatic fashion. + +Another bit of jargon. + +We will also use the basis +vectors to define locations + +and to define directions +in a lattice. + +To distinguish three integers +that indicate a plane, and you + +all know this from previous +experience, the parentheses + +says plane, an individual +plane. + +There are other times when you +would like to use the indices + +of one representative plane to +indicate the entire set of + +planes that are related by the +symmetry of the crystal. + +So let me give one +specific example. + +Suppose we had a cubic crystal, +where these are the + +three translations that form +the edge of the unit cell. + +And let's say that this is a1, +this is a2, and this is a3. + +I'm using a1, a2, and +a3, not a, b, and c. + +But let's not go there. + +OK, these are lattice points. + +And if I look at this plane +that's perpendicular to a1 and + +cuts it at one lattice +point, l, this would + +be the 1, 0, 0 plane. + +And I would indicate that that +is an individual plane that + +we're talking about. + +But if this crystal is cubic, +all six faces of the set, 1, + +0, 0; 0, 1, 0; 0, 0, 1; and then +the plane that's in the + +opposite direction, minus +1, 0, 0; 0, minus 1, 0; + +and 0, 0, minus 1. + +These six planes define the +surfaces of the cube. + +So there are times, since these +are equivalent to planes + +and will have the same +properties, the same hardness, + +the same [? edge ?] bits and +everything else, there are + +times when we may want to +refer to the entire + +symmetrical set. + +And we do that. + +We call that set a form. + +It is a symmetry-related set. + +And you can pick any +one you like. + +Generally, you pick one with +simple indices, like the one + +that is perpendicular to +the translation a. + +And then you indicate +by braces, which is + +the symbol for set. + +This means the set 1, 0, 0, and +that would correspond to + +all six of these faces. + +The number, if you do this in +reverse, and I'm going to give + +you the indices, what are +the separate faces? + +That depends on the symmetry. + +So to give you an example, if +I have a unit cell that has + +three orthogonal translations, +and this is a, and this is b, + +and this is c, so that there +is no cubic symmetry to it. + +This face, which would be 1, +0, 0, and the one that cuts + +the axes at minus a, minus 1, 0 +0, those are going to be the + +only faces with a single 1 and +a pair of 0's which are + +equivalent by symmetry. + +So in this case, for this brick +shaped unit cell, 1, 0, + +0 would mean this pair of two +faces, rather than six. + +So to go from a representative +face to the set of planes, you + +have to know the symmetry. + +If you can write the planes on +the basis of symmetry, take + +one representative and +let that be the form. + +So it leads one to observe +that crystals undergoing + +plastic deformation +have bad form. + +Yeah? + +AUDIENCE: Is that different +from when you + +talk about a direction? + +PROFESSOR: Yes, yes. + +You will see in just a moment +that we use the same system of + +three integers, but in order to +distinguish which one he's + +talking about when one's +thinking about integers with a + +different set of numbers. + +Again, if we use the lattice as +the basis of a coordinate + +system, another thing we might +want to specify is the + +orientation of a rational +direction. + +And let me go to a +two-dimensional case. + +Assume that c goes +straight up. + +Directions of easy plastic +deformation will very often + +involve integral number +of translations. + +For example, this direction here +is obtained by going one + +translation in the a +direction plus one + +translation in the b direction. + +So we could use the pair of +integers 1, 1, and if we are + +normal to see we'd use a 0 +for the third integer. + +But how are we going to tell +whether we're talking about a + +direction or a plane? + +And the way one does that is +to use square braces to + +indicate one particular +direction. + +You may want to also indicate +the location of a particular + +atom within the unit cell. + +In order to do that, one could +really use the location of a + +vector, the components of a +vector, xa plus yb plus zc, + +the vector from the origin to +that atom as coefficients + +which correspond to +the atom location. + +So if that is the case, +the numbers + +are usually not integers. + +And one simply uses the +three integers in + +an unadorned fashion. + +So the lattice translations +give you the basis of a + +coordinate system, and we use +those to specify features, + +rational or not, of planes and +directions and coordinates. + +OK, any questions here? + +OK, we are next going to take +the first small step in a + +process of synthesis. + +We have found that there are, +in two dimensions, five + +distinct kinds of lattices. + +The oblique, the rectangular, +the centric rectangular, the + +square, and the hexagonal. + +Five kinds of lattices. + +We've shown, to this point, that +each of these lattices + +can accommodate a certain +rotational symmetry. + +1 or 2 here. + +m and m for the rectangular +and centric rectangular. + +4, the fourfold axis +for a square. + +3 or 6 for the hexagonal +lattice. + +So what I would like to do next, +after we make a brief + +direct diversion, is to combine +with each of these + +nets one of the two symmetries +which can be + +accommodated in that net. + +And what we will have determined +then are the + +patterns' lattice and symmetry, +which can exist in + +two dimensions. + +The sort of things we look at +actually, like the pattern of + +square tiles on the floor, or +the two-dimensional pattern + +that is on a fabric design. + +So we'll derive those +exhaustively. + +The thing that results is +something that is called a + +plane group. + +And I'm going to take this +through in detail because + +there are not that many +combinations that can be made. + +And the number is enough +to count on + +your fingers and toes. + +You've got to use both, so +they're a fair number, but not + +a staggering number. + +If we were to do this exercise +in three dimensions, there + +would be 230 distinct +combinations. + +And that's too much for +anybody to go through. + +I know of very few people who +work professionally in this + +area who've actually sat down +and derived every single one. + +If you know the principles of +the derivation and know how + +you could go about doing it if +you were forced to, that's + +sufficient. + +The results are tabulated in +an admirable compilation. + +We mentioned that at +the beginning. + +This is the International +Tables for X-ray + +Crystallography, Volume 1. + +So what we should end up with is +a way for you to go to this + +reference data and know +how to interpret it + +and make use of it. + +But this is a nice microcosm. + +There are not many plane +groups, and to do this + +exhaustively, will let us see +the sort of reasoning that + +goes into it. + +I have to tell you that this +is not in Buerger's book. + +We're going to do +two-dimensional + +crystallography first, +and then extend + +it in a third direction. + +In fact, I know of no +book that does this. + +And so you're going to get a +unique, handwritten document + +by none other than yours truly +that will do this in detail + +every step of the way. + +And I don't know of any other +place where this is done. + +Now, what is the origin +of this name? + +Plane, well, these +are symmetries + +confined to a plane. + +And then there's this mysterious +term, group. + +And the corresponding thing +in 3D is something + +called a space group. + +This is a language derived from +a branch of mathematics + +that is called group theory, and +it is exactly the language + +that describes things +that we've mentioned + +conversationally, such as if you +take two transformations + +and perform them in succession, +they're going to + +give you a third that +has to be present. + +If you've got two present, +there must be a third. + +We talk about symmetries +being self consistent. + +If you have a rotation operation +that is not an + +integral submultiple of 2 pi, +it's not going to be self + +consistent because you go +around, and around, and + +around, and you will never +come exactly full circle. + +So group theory is a branch of +mathematics that deals with + +concepts of this sort. + +So it's not very hard to +develop, and it gives its + +ideas to the notation that is +used in crystallography. + +So let me say a few words +about group theory. + +What is a group? + +A group is a set of elements-- + +And what are elements? + +Elements are things-- + +For which a law of combination +is defined. + +And the nature of the elements +can be very, + +very different things. + +They could be numbers. + +They could be complex numbers, +and the law of combination + +here might be multiplication. + +They could be matrices, for +which the law of combination + +is defined as matrix +multiplication. + +Or they could be pots of +different color paint, for + +which the law of combination is +defined as mixing the two + +colors 50-50. + +I don't know any practical +application of that sort of + +group, but nevertheless, it +follows the definition, a set + +of things for which a law of +combination is defined. + +And in addition, which satisfies +three so-called + +group postulates. + +And the group postulates are +the combination of any two + +elements is also a member +of the group. + +The second group postulate +is that the identity-- + +I'm going to call it +just identity-- + +and let me define, identity +is doing nothing-- + +Is also a member of the group. + +And if we define the identity +operation as I, this means + +that for every element, I +followed by a or a followed by + +I, is the same as a by itself. + +If the law of multiplication +were just arithmetic + +multiplication, then number +1 would be the identity + +operation because 1 times any +number gives you the number. + +Any number times 1 gives you +the same number back again. + +And the third postulate is that, +for every element, an + +inverse exists-- + +let's call the elements +a and a minus 1-- + +such that a followed by a +minus 1 is equal to the + +identity operation, and the +inverse element followed by + +the original element, a, is also +the identity operation. + +So if the law of combination +were defined as + +multiplication, you would have +to find, for every number, + +another number, which multiplied +by it, gives you + +the number 1. + +OK, let me now illustrate with +a couple of simple examples. + +Let's consider the set of +numbers 1, n minus 1. + +The number of elements in the +group is said to be the rank + +of the group, or some people +like to use the term order. + +And I don't like that term +because second order or fourth + +order is a term applied to +quantities which are not + +terribly important. + +So we expand this except for +higher order terms, which are + +negligible. + +And I don't like that +connotation. + +So I will not use order, +although it's sometimes used + +to talk about the +rank of a group. + +The rank or order of the group +is simply the number of + +elements contained in a set. + +So let's show that the numbers +1 and minus 1 constitute a + +group of rank two. + +Is the combination of any +pair of elements also a + +member of the group? + +Well, to do this, it's +convenient to set up an array + +called the group multiplication +table. + +And what you do is you simply +put the elements of the group + +along a row. + +And in this case, it's +1 and minus 1. + +And then you put the same +elements along a column, and + +then you combine them. + +1 times 1 is 1. + +Minus 1 times 1 is minus 1. + +1 times minus 1 is minus 1. + +Minus 1 times minus +1 is plus 1. + +Sometimes, as I'm giving this +part of the lecture, somebody + +passes down the hallway, and +they hear 1 times 1 is 1. + +1 times minus 1-- + +and they go in reverse to see +what in the world could be + +going on in this high-powered +mathematical lecture. + +That's why I close the door. + +OK, so any combination +of elements is also a + +member of the group. + +Is the identity operation +present? + +Yes because minus 1 times plus +1 or plus 1 times minus 1 + +gives you the same element +back again. + +So for every element in the +group, the combination of any + +two elements is present. + +For each operation, we've shown +that an inverse exists + +and for every element there's an +identity operation, and the + +inverse exists. + +So the pair of numbers, not +terribly exciting, 1 and minus + +1 where the law of combination +is defined is a + +group of rank 2. + +I'll give you another example. + +I won't bother to carry out all +the terms, but the numbers + +1, minus 1, i, and minus i, +where i is equal to the square + +root of minus 1, and where the +law of combination is defined + +as multiplication, constitute +a group of rank 4. + +With this simple introduction, +I think one can see that + +symmetry transformations can be +regarded as operations that + +are elements in a group. + +And let me give you +a simple example. + +Let's look at a combination. + +We still haven't considered the +mind-boggling possibility + +of having more than one symmetry +element present in a + +space at the same time. + +But let's suppose we have two +mirror planes that are + +completely orthogonal, and see +what sort of pattern they + +would generate. + +Here's a first motif. + +If I call this mirror plane m1, +and this mirror plane m2. + +m1 is going to take this +object and reflect + +it across to here. + +m2 will take this object and +reflect it down to here. + +Take this one, and reflect +it down to here. + +And now I know how this is +related to this, how this is + +related to this, how this +is related to this. + +But this one and this one are +exactly the same thing. + +And those two objects are not +related by reflection. + +If this is a right-handed one, +this is a left-handed one, + +this is a left-handed one, and +this is a right-handed one. + +So if something relates these +two, it has to be something + +that does not produce +an enantiomorph. + +The only thing that's possible +then would be translation. + +And these two guys are not +parallel to one another. + +You can't get this one +by just sliding + +this parallel to itself. + +The only thing that's +left is rotation. + +And, lo and behold, we can get +from this one to this one by a + +180-degree rotation. + +And we can get from this +one to this one by + +a 180-degree rotation. + +So here's an example of a way +in which we've combined + +without showing why this is +possible, or how I got there. + +Here's a combination of symmetry +elements that gives + +us a possible arrangement +of objects in space. + +It's going to be convenient to +have a notation to indicate + +such combinations. + +And we call them Harry, George, +and Sam, or some + +popular, affectionate name. + +Or call them number 1, +number 2, number 3. + +But a nice notation is going to +be a descriptive one which + +tells you what you have. + +And what is done in +crystallography is to indicate + +these possible combinations +by a running list of the + +different kinds of symmetry +elements that are present. + +And here, we've got a twofold +axis, for which the symbol is + +2, and two mirror planes that +are different and function in + +different ways in the pattern. + +So this combination +is called 2mm. + +OK, that's getting ahead +of our story. + +But what I wanted to do now is +to show you that this set of + +symmetry elements contains +four operations that + +constitute a group. + +There's the operation +of a one-fold axis. + +That's the identity operation. + +There is a reflection +across the first + +type of mirror plane. + +And notice, now, the utility +of having a symbol that + +indicates a specific +operation rather + +than a symmetry element. + +There's a second reflection +operation, sigma 2, and there + +is a rotation operation through +a 180 degrees, A pi. + +So I'd like to show that these +four operations constitute a + +group of rank 4. + +So how do we show this? + +We first set up the group +multiplication table. + +And then we simply +combine these + +four operations pairwise. + +Put the same 1, sigma 1, +sigma 2, and A pi down + +this side of the array. + +Doing nothing, doing nothing, is +the same as a one-fold axis + +doing nothing. + +Doing a reflection sigma 1 +followed by doing nothing + +gives you sigma 1 back again. + +Doing a reflection sigma 2 +followed by doing nothing + +gives you sigma 2 back again. + +And similarly, rotating +A pi followed by doing + +nothing is the same. + +If I go along the columns, +doing nothing followed by + +sigma 1 is sigma 1. + +Sigma 1 and 1 combined +is sigma 2. + +A pi combined with +sigma 1 is A pi. + +So far so good, but +not surprising. + +Doing sigma 1 and following it +by sigma 1 is reflecting left + +to right across mirror plane 1, +and then reflecting right + +back again. + +So that is going to be a +one-fold axis doing nothing. + +Doing sigma 1 following up by +sigma 2 would reflect across, + +and then follow up by reflection +in the second + +mirror plane. + +I get from the first one +to the final one by + +the rotation A pi. + +So this is A pi. + +And if I do the first +reflection, sigma 1, and + +follow that by A pi, that gets +me from number 1 to number 2 + +to number 3. + +And I get from number 1 to +number 3 directly by the + +reflection operation, sigma 2. + +OK, you notice what's +happening? + +I get the same four elements +back again in + +every column or row. + +Sigma 1, 1, A pi, sigma 2. + +And if I rattle these off +quickly, this as A pi. + +This is identity, and +this is sigma 1. + +And this will be sigma 2. + +This will be sigma 1. + +And this will be the +identity operation. + +So the first group postulate +is satisfied. + +These four elements combined +pairwise always give you + +nothing but one of these +elements back. + +An identity operation is present +because the one-fold + +rotation axis is the same as +leaving the thing alone. + +And we've seen that for every +operation, an inverse exists + +because 1 occurs once in +each row and column. + +So sigma 2 is its own inverse, +and for sigma 1, sigma 1 is + +its own inverse. + +For A pi, A pi is +its own inverse. + +So an inverse exists. + +So we've got a group. + +And this is another way of +saying, in general terms, if + +we put two mirror planes and a +twofold axis together in this + +specific fashion, these +operations, when they go to + +work on an initial motif, +reproduce a finite set of + +objects and not a clutter that +just fills space and never + +closes upon itself. + +Yes, sir? + +AUDIENCE: I see why you have +sigma 1, sigma 2, A pi in that + +group, but why do you have the +1, which is a conversion? + +PROFESSOR: OK. + +If I didn't put it in-- no, +that's the identity operation. + +This is a one-fold axis. + +Just this 2 was a +twofold axis. + +So one-fold axis is a nice +symbol for identity because it + +doesn't do anything. + +It picks something up and +puts it right back down + +where it came from. + +OK. + +Yeah. + +That's deceptive because 1, +when we're talking about + +multiplication of numbers, +also functions as + +the identity operation. + +Yeah? + +AUDIENCE: If all these +symmetries are commutative, + +[? that is, ?] + +if they all commute, do you +really [INAUDIBLE] bottom + +diagonal [INAUDIBLE]? + +PROFESSOR: In general, yes. + +AUDIENCE: Generally? + +PROFESSOR: Yeah. + +Actually, this is a special +group because if I have two + +elements, a, and take b and +follow it by a, that is the + +same result as a +followed by b. + +And a group that has +this character + +is said to be abelian. + +There's a standing rotten joke +in mathematics that asks + +rhetorically, what is +purple and commutes? + +The answer is an +abelian grape. + +I don't think it's terribly +funny either, but if you had a + +gaggle of mathematicians here, +they would chortle and double + +over in laughter. + +Ha, ha, ha, abelian grape. + +Well, I don't feel badly. + +You react about the same +way to some of my + +funny things, too. + +But you get used to that +sort of thing. + +All right. + +The feeling I want to leave you +with at this point is the + +idea that group theory and +some of its concepts are + +exactly what we're meaning when +we grope for a definition + +of the fact that a certain +collection of symmetry + +operation should be finite. + +That is to say, it's finite. + +The operations combined on +each other have to give a + +finite number, must constitute +a group. + +And the main reason for being +familiar with this is that + +group theory forms the basis of +a lot of the words that are + +used to describe the + +combinations of symmetry elements. + +For example, what we have +derived here, the symmetry + +that's called 2mm, is something +that's called a + +point group. + +Point because there is at +least one point in space + +that's left unchanged, and +that's this point of + +intersection of all three +symmetry elements. + +And it's called a group +because the individual + +operations of these symmetry +elements, when combined + +according to group theory, +can be shown to + +constitute a group. + +The patterns that we get when we +add symmetry elements to a + +lattice are groups in the +sense, if you regard the + +pattern as extending infinitely +in all directions, + +that the combination of any +two elements gives you + +something that's also +in the group. + +But the number of elements +is infinite. + +For example, in the lattice, +here's T1. + +Here's T2. + +Every other lattice point +can be described as some + +combination of T1 +followed by T2. + +But the numbers in +front of those + +translations can be infinite. + +If we put a symmetry element +in this lattice, like a + +twofold axis, for example, the +translations reproduce this + +twofold axis to an infinite +number of locations. + +But yet, all of the group +postulates are satisfied. + +The number of elements in the +group does, however, not have + +to be finite. + +So that is another distinction +that's worth making, that + +there are infinite groups and +there are finite groups. + +And the number of elements +can be infinite. + +Collection of symmetry elements +that leave one point + +in space unmoved is called +a point group. + +If we do something like this, +put a twofold axis in + +combination with a pair of +translations, that is an + +infinite set of operations that +acts on all of space. + +This is something that's +called a space group. + +Another designation, +distinction, that's sometimes + +useful to make are +crystallographic point groups, + +such as this one, 2mm, as +opposed to combinations of + +symmetry elements, which are +perfectly lovely and which are + +valid groups, such as a +combination of rotations of 2 + +pi over 5, or a combination +of a fivefold axis + +with a mirror plane. + +Perfectly lovely symbols, +constitute groups, but these + +are non-crystallographic + +These would be + +non-crystallographic point groups. + +Satisfy all the requirements of +the group, but if it's to + +be in a crystal, the fivefold +axis must be combined with + +translation, and that's +impossible. + +So you can have + +non-crystallographic point groups. + +There are no +non-crystallographic space + +groups because they are, by +definition, something that + +involve translation yet +constitute groups. + +All right. + +Set the stage for next time, so +you all come back excited. + +We have shown that there are a +limited number of symmetry + +elements that are possible in +a lattice, rotation 1, 2, 3, + +4, and 6 in a mirror plane. + +And these are now examples +of what we would call + +crystallographic point groups. + +These would be the sort of +symmetry elements that are + +candidates for two-dimensional +patterns. + +But are these the only +symmetries that can be added + +to lattices? + +Could we not combine a mirror +plane with a twofold axis? + +The answer I say to +that is, sure. + +You bet you can. + +You just did it for us. + +But could you combine a mirror +plane with a threefold axis, a + +mirror plane with a fourfold +axis, a mirror plane with a + +sixfold axis? + +The answer to all of those +questions are yes. + +So there are going to be spaces +here, where there will + +be additional groups. + +And when we're done, we will +have the two-dimensional + +crystallographic point groups. + +But now I have to be able +to complete something. + +If I take A pi and combine it +with a mirror operation sigma + +1, what do I get? + +If I take A 2 pi over 3, a +threefold rotation, combine + +that with a mirror plane +that passes through + +it, what do I get? + +Again, a characteristic of +symmetry theory is that + +whenever I take a motif and +repeat it by operation number + +1 to get a second motif, and +then I repeat that by + +operation number +2, I have three + +things that are identical. + +And there must be some way, +some operation, that + +automatically arises that +tells me how number 1 is + +related to number 2. + +Number 1 is related +to number 3. + +Tied in with group theory, this +says that if you combine + +operation 1 in a space, if +it's to be a group, if + +operation number 2 is present, +you must combine those two + +steps, and whatever pops up must +be a member of the set of + +operations that are present. + +So we're going to have to come +up with something that I call + +combination theorems. + +And this is simply expressing +the result of a combination of + +two elements in a group +multiplication table. + +It goes with a caveat. + +If you're so excited about this +stuff, you're going to + +run home and start reading +Buerger's book as + +soon as you get there. + +You can regard these symmetry +transformations as operators. + +And you're familiar with other +sorts of operators like d by + +dx, d by dy. + +And when you apply them in +succession, you actually write + +it as a product. + +d by dy followed by d by dx you +write as d squared dxdy. + +Or you write it as d squared +dx squared when you + +differentiate twice. + +You don't mean you take the +differential of the function + +with respect to x and +then square it. + +You mean you do this +operation twice. + +So these are all operators. + +And what we usually understand +is that if you do d by dy + +first and then follow that with +d by dx, the sequence of + +operation goes from +right to left. + +And I think that will come right +quite naturally to you. + +You do that with differentials +and other sort of operators. + +That is what we'll do. + +Not Martin Buerger. + +A very strong-minded person, +and he did what + +he thought was sensible. + +And he said we read things +from left to right. + +We read everything from +left to right. + +So I will be damned if I'm going +to write d by dx, d by + +dy to be a sequence of +operations that goes from + +right to left. + +So all throughout Buerger's +book-- and it's easy to get + +adjusted to, if he writes A dot +B, he means B followed by + +A. Whereas normally, in the +calculus of operations, we + +will use, as the rest of the +world does, this is A followed + +by B. Trivial point, but one +that can throw you for a loop + +the first time you see +it in Buerger's book + +if you follow it. + +Distinction does not matter +if the group is abelian. + +So that the order of operations +doesn't make any + +difference. + +OK, that's enough for one day. + +Beginning next time, know we +will start to begin this + +process of synthesis. + +And the first thing we'll ask +is, how do you combine a + +rotation operation with a +reflection operation? + +See you next week. \ No newline at end of file diff --git a/kefsxztSX74.txt b/kefsxztSX74.txt new file mode 100644 index 0000000000000000000000000000000000000000..6e428b88847cb71a4c50d9e6b9eb4191693e7094 --- /dev/null +++ b/kefsxztSX74.txt @@ -0,0 +1,1947 @@ +align:start position:0% + +last time we discussed the differential + + align:start position:0% +last time we discussed the differential + + + align:start position:0% +last time we discussed the differential +equation I'll be posting notes very soon + + align:start position:0% +equation I'll be posting notes very soon + + + align:start position:0% +equation I'll be posting notes very soon +I'll probably this afternoon at some + + align:start position:0% +I'll probably this afternoon at some + + + align:start position:0% +I'll probably this afternoon at some +time and last time we solve the + + align:start position:0% +time and last time we solve the + + + align:start position:0% +time and last time we solve the +differential equation we found the + + align:start position:0% +differential equation we found the + + + align:start position:0% +differential equation we found the +energy eigenstates and then turned into + + align:start position:0% +energy eigenstates and then turned into + + + align:start position:0% +energy eigenstates and then turned into +an algebraic analysis in which we + + align:start position:0% +an algebraic analysis in which we + + + align:start position:0% +an algebraic analysis in which we +factorize the Hamiltonian which meant + + align:start position:0% +factorize the Hamiltonian which meant + + + align:start position:0% +factorize the Hamiltonian which meant +essentially you could write the + + align:start position:0% +essentially you could write the + + + align:start position:0% +essentially you could write the +Hamiltonian up to an overall constant + + align:start position:0% +Hamiltonian up to an overall constant + + + align:start position:0% +Hamiltonian up to an overall constant +that it doesn't complicate matters as + + align:start position:0% +that it doesn't complicate matters as + + + align:start position:0% +that it doesn't complicate matters as +the product of an a dagger a and that + + align:start position:0% +the product of an a dagger a and that + + + align:start position:0% +the product of an a dagger a and that +was very useful to show for example at + + align:start position:0% +was very useful to show for example at + + + align:start position:0% +was very useful to show for example at +any energy eigenstate would have to have + + align:start position:0% +any energy eigenstate would have to have + + + align:start position:0% +any energy eigenstate would have to have +energy greater than H Omega over 2 we + + align:start position:0% +energy greater than H Omega over 2 we + + + align:start position:0% +energy greater than H Omega over 2 we +call this a dagger a the number operator + + align:start position:0% +call this a dagger a the number operator + + + align:start position:0% +call this a dagger a the number operator +n which is a hermitian operator recall + + align:start position:0% +n which is a hermitian operator recall + + + align:start position:0% +n which is a hermitian operator recall +that the dagger of a product of + + align:start position:0% +that the dagger of a product of + + + align:start position:0% +that the dagger of a product of +operators is the reverse order product + + align:start position:0% +operators is the reverse order product + + + align:start position:0% +operators is the reverse order product +of the dagger so the dagger of a dagger + + align:start position:0% +of the dagger so the dagger of a dagger + + + align:start position:0% +of the dagger so the dagger of a dagger +a is itself and then a was related to X + + align:start position:0% +a is itself and then a was related to X + + + align:start position:0% +a is itself and then a was related to X +and P and so was a dagger recall that X + + align:start position:0% +and P and so was a dagger recall that X + + + align:start position:0% +and P and so was a dagger recall that X +and P are hermitian and their overall + + align:start position:0% +and P are hermitian and their overall + + + align:start position:0% +and P are hermitian and their overall +constants here that we wrote last time + + align:start position:0% +constants here that we wrote last time + + + align:start position:0% +constants here that we wrote last time +but now they're not that urgent and a + + align:start position:0% +but now they're not that urgent and a + + + align:start position:0% +but now they're not that urgent and a +and a dagger the commutator is equal to + + align:start position:0% +and a dagger the commutator is equal to + + + align:start position:0% +and a dagger the commutator is equal to +1 that was very useful finally we also + + align:start position:0% +1 that was very useful finally we also + + + align:start position:0% +1 that was very useful finally we also +show that while the energy of any state + + align:start position:0% +show that while the energy of any state + + + align:start position:0% +show that while the energy of any state +would have to be greater than H Omega + + align:start position:0% +would have to be greater than H Omega + + + align:start position:0% +would have to be greater than H Omega +over 2 if you had a stay that is killed + + align:start position:0% +over 2 if you had a stay that is killed + + + align:start position:0% +over 2 if you had a stay that is killed +by a heart it will have the lowest + + align:start position:0% +by a heart it will have the lowest + + + align:start position:0% +by a heart it will have the lowest +allowed energy which is H Omega over 2 + + align:start position:0% +allowed energy which is H Omega over 2 + + + align:start position:0% +allowed energy which is H Omega over 2 +and therefore that is the ground state + + align:start position:0% +and therefore that is the ground state + + + align:start position:0% +and therefore that is the ground state +and we looked at this differential + + align:start position:0% +and we looked at this differential + + + align:start position:0% +and we looked at this differential +equation and we found this Gaussian wave + + align:start position:0% +equation and we found this Gaussian wave + + + align:start position:0% +equation and we found this Gaussian wave +function and it's a first order + + align:start position:0% +function and it's a first order + + + align:start position:0% +function and it's a first order +differential equation and + + align:start position:0% +differential equation and + + + align:start position:0% +differential equation and +referre has just one solution and + + align:start position:0% +referre has just one solution and + + + align:start position:0% +referre has just one solution and +therefore there is just one ground state + + align:start position:0% +therefore there is just one ground state + + + align:start position:0% +therefore there is just one ground state +and it's a bound state and of course you + + align:start position:0% +and it's a bound state and of course you + + + align:start position:0% +and it's a bound state and of course you +wouldn't expect more than one ground + + align:start position:0% +wouldn't expect more than one ground + + + align:start position:0% +wouldn't expect more than one ground +state because there's no degeneracies in + + align:start position:0% +state because there's no degeneracies in + + + align:start position:0% +state because there's no degeneracies in +the bound state spectrum of a + + align:start position:0% +the bound state spectrum of a + + + align:start position:0% +the bound state spectrum of a +one-dimensional potential so we found + + align:start position:0% +one-dimensional potential so we found + + + align:start position:0% +one-dimensional potential so we found +one ground state was Phi 0 and it's + + align:start position:0% +one ground state was Phi 0 and it's + + + align:start position:0% +one ground state was Phi 0 and it's +killed by a which it means that it's + + align:start position:0% +killed by a which it means that it's + + + align:start position:0% +killed by a which it means that it's +killed by n hat because a is to the + + align:start position:0% +killed by n hat because a is to the + + + align:start position:0% +killed by n hat because a is to the +right in an hat + + align:start position:0% +right in an hat + + + align:start position:0% +right in an hat +so the a finds Phi 0 and just kills it + + align:start position:0% +so the a finds Phi 0 and just kills it + + + align:start position:0% +so the a finds Phi 0 and just kills it +now the other thing to know this is that + + align:start position:0% +now the other thing to know this is that + + + align:start position:0% +now the other thing to know this is that +the Hamiltonian is really pretty much + + align:start position:0% +the Hamiltonian is really pretty much + + + align:start position:0% +the Hamiltonian is really pretty much +the same thing as the number operator + + align:start position:0% +the same thing as the number operator + + + align:start position:0% +the same thing as the number operator +multiplied by something with units of + + align:start position:0% +multiplied by something with units of + + + align:start position:0% +multiplied by something with units of +energy the number operator has no units + + align:start position:0% +energy the number operator has no units + + + align:start position:0% +energy the number operator has no units +because a and a dagger have no units and + + align:start position:0% +because a and a dagger have no units and + + + align:start position:0% +because a and a dagger have no units and +that's very useful so it's like a + + align:start position:0% +that's very useful so it's like a + + + align:start position:0% +that's very useful so it's like a +dimensionless version of the energy and + + align:start position:0% +dimensionless version of the energy and + + + align:start position:0% +dimensionless version of the energy and +certainly if you have an eigenstate of H + + align:start position:0% +certainly if you have an eigenstate of H + + + align:start position:0% +certainly if you have an eigenstate of H +it must be an eigenstate of n and the + + align:start position:0% +it must be an eigenstate of n and the + + + align:start position:0% +it must be an eigenstate of n and the +eigen the eigenvalue of n if we call it + + align:start position:0% +eigen the eigenvalue of n if we call it + + + align:start position:0% +eigen the eigenvalue of n if we call it +capital n therefore you can imagine this + + align:start position:0% +capital n therefore you can imagine this + + + align:start position:0% +capital n therefore you can imagine this +equation acting on an eigenstate which + + align:start position:0% +equation acting on an eigenstate which + + + align:start position:0% +equation acting on an eigenstate which +happens to be an eigenstate of N or of H + + align:start position:0% +happens to be an eigenstate of N or of H + + + align:start position:0% +happens to be an eigenstate of N or of H +on the left hand side you would read the + + align:start position:0% +on the left hand side you would read the + + + align:start position:0% +on the left hand side you would read the +energy and on the right hand side you + + align:start position:0% +energy and on the right hand side you + + + align:start position:0% +energy and on the right hand side you +would read the eigenvalue of the N + + align:start position:0% +would read the eigenvalue of the N + + + align:start position:0% +would read the eigenvalue of the N +operator so that gives you a very nice + + align:start position:0% +operator so that gives you a very nice + + + align:start position:0% +operator so that gives you a very nice +simple expression that you see that the + + align:start position:0% +simple expression that you see that the + + + align:start position:0% +simple expression that you see that the +energy is the number plus 1/2 multiplied + + align:start position:0% +energy is the number plus 1/2 multiplied + + + align:start position:0% +energy is the number plus 1/2 multiplied +by H bar armino so that's pretty much + + align:start position:0% +by H bar armino so that's pretty much + + + align:start position:0% +by H bar armino so that's pretty much +the content of what we reach last + + align:start position:0% +the content of what we reach last + + + align:start position:0% +the content of what we reach last +element now we have to complete this + + align:start position:0% +element now we have to complete this + + + align:start position:0% +element now we have to complete this +solution and the plan for today is to + + align:start position:0% +solution and the plan for today is to + + + align:start position:0% +solution and the plan for today is to +complete the solution familiarize + + align:start position:0% +complete the solution familiarize + + + align:start position:0% +complete the solution familiarize +ourselves with these operators learn how + + align:start position:0% +ourselves with these operators learn how + + + align:start position:0% +ourselves with these operators learn how +to work with the harmonic oscillator + + align:start position:0% +to work with the harmonic oscillator + + + align:start position:0% +to work with the harmonic oscillator +with them and then we'll leave the + + align:start position:0% +with them and then we'll leave the + + + align:start position:0% +with them and then we'll leave the +harmonic oscillator for 4 + + align:start position:0% +harmonic oscillator for 4 + + + align:start position:0% +harmonic oscillator for 4 +the time being let you do some exercises + + align:start position:0% +the time being let you do some exercises + + + align:start position:0% +the time being let you do some exercises +with it but turn to scattering state so + + align:start position:0% +with it but turn to scattering state so + + + align:start position:0% +with it but turn to scattering state so +the second part of today's lecture we + + align:start position:0% +the second part of today's lecture we + + + align:start position:0% +the second part of today's lecture we +will be talking about scattering States + + align:start position:0% + + + + align:start position:0% + +okay so of when we looked at this thing + + align:start position:0% +okay so of when we looked at this thing + + + align:start position:0% +okay so of when we looked at this thing +and you have a number operator which + + align:start position:0% +and you have a number operator which + + + align:start position:0% +and you have a number operator which +includes the Hamiltonian it's a good + + align:start position:0% +includes the Hamiltonian it's a good + + + align:start position:0% +includes the Hamiltonian it's a good +idea to try to understand how it + + align:start position:0% +idea to try to understand how it + + + align:start position:0% +idea to try to understand how it +interacts with the other operators that + + align:start position:0% +interacts with the other operators that + + + align:start position:0% +interacts with the other operators that +you have here and a good question + + align:start position:0% +you have here and a good question + + + align:start position:0% +you have here and a good question +whenever you have operators is the + + align:start position:0% +whenever you have operators is the + + + align:start position:0% +whenever you have operators is the +commutator so you can ask what is the + + align:start position:0% +commutator so you can ask what is the + + + align:start position:0% +commutator so you can ask what is the +commutator of n with a and this + + align:start position:0% +commutator of n with a and this + + + align:start position:0% +commutator of n with a and this +commutator is going to show up but you + + align:start position:0% +commutator is going to show up but you + + + align:start position:0% +commutator is going to show up but you +know it's basically the kind of thing + + align:start position:0% +know it's basically the kind of thing + + + align:start position:0% +know it's basically the kind of thing +you have a and a dagger you ask what is + + align:start position:0% +you have a and a dagger you ask what is + + + align:start position:0% +you have a and a dagger you ask what is +the commutator if you have n now you ask + + align:start position:0% +the commutator if you have n now you ask + + + align:start position:0% +the commutator if you have n now you ask +what is the commutator with the other + + align:start position:0% +what is the commutator with the other + + + align:start position:0% +what is the commutator with the other +thing so n with a would be the + + align:start position:0% +thing so n with a would be the + + + align:start position:0% +thing so n with a would be the +commutator of a dagger with a with a + + align:start position:0% +commutator of a dagger with a with a + + + align:start position:0% +commutator of a dagger with a with a +like that and sometimes I will not write + + align:start position:0% +like that and sometimes I will not write + + + align:start position:0% +like that and sometimes I will not write +the hats to write things more quickly + + align:start position:0% +the hats to write things more quickly + + + align:start position:0% +the hats to write things more quickly +now in this commutator you can move the + + align:start position:0% +now in this commutator you can move the + + + align:start position:0% +now in this commutator you can move the +a out and you have a dagger a a and a + + align:start position:0% +a out and you have a dagger a a and a + + + align:start position:0% +a out and you have a dagger a a and a +dagger a is minus 1 because a dagger is + + align:start position:0% +dagger a is minus 1 because a dagger is + + + align:start position:0% +dagger a is minus 1 because a dagger is +1 so this is minus a so that's pretty + + align:start position:0% +1 so this is minus a so that's pretty + + + align:start position:0% +1 so this is minus a so that's pretty +nice it's simple + + align:start position:0% +nice it's simple + + + align:start position:0% +nice it's simple +how about n with a dagger well this + + align:start position:0% +how about n with a dagger well this + + + align:start position:0% +how about n with a dagger well this +would be a dagger a with a dagger a + + align:start position:0% +would be a dagger a with a dagger a + + + align:start position:0% +would be a dagger a with a dagger a +dagger with a dagger commute so this a + + align:start position:0% +dagger with a dagger commute so this a + + + align:start position:0% +dagger with a dagger commute so this a +dagger can go out and you get a a dagger + + align:start position:0% +dagger can go out and you get a a dagger + + + align:start position:0% +dagger can go out and you get a a dagger +and that's 1 so you get a dagger + + align:start position:0% + + + + align:start position:0% + +so it's it's a nice kind of commutation + + align:start position:0% +so it's it's a nice kind of commutation + + + align:start position:0% +so it's it's a nice kind of commutation +relation you have commutation reserved X + + align:start position:0% +relation you have commutation reserved X + + + align:start position:0% +relation you have commutation reserved X +with P given a constant now n with a + + align:start position:0% +with P given a constant now n with a + + + align:start position:0% +with P given a constant now n with a +gives a number times a and commutator + + align:start position:0% +gives a number times a and commutator + + + align:start position:0% +gives a number times a and commutator +with a dagger gives a number times a + + align:start position:0% +with a dagger gives a number times a + + + align:start position:0% +with a dagger gives a number times a +dagger and those numbers are pretty + + align:start position:0% +dagger and those numbers are pretty + + + align:start position:0% +dagger and those numbers are pretty +significant so I'll write this again and + + align:start position:0% +significant so I'll write this again and + + + align:start position:0% +significant so I'll write this again and +with a is minus a m n with a dagger is + + align:start position:0% +with a is minus a m n with a dagger is + + + align:start position:0% +with a is minus a m n with a dagger is +plus a dagger this is part of the reason + + align:start position:0% +plus a dagger this is part of the reason + + + align:start position:0% +plus a dagger this is part of the reason +as we will see soon that the name of a + + align:start position:0% +as we will see soon that the name of a + + + align:start position:0% +as we will see soon that the name of a +which we call destruction operator + + align:start position:0% +which we call destruction operator + + + align:start position:0% +which we call destruction operator +because it destroys the vacuum it's + + align:start position:0% +because it destroys the vacuum it's + + + align:start position:0% +because it destroys the vacuum it's +sometimes called lowering operator + + align:start position:0% +sometimes called lowering operator + + + align:start position:0% +sometimes called lowering operator +because it comes with a negative sign + + align:start position:0% +because it comes with a negative sign + + + align:start position:0% +because it comes with a negative sign +here and we'll see a better reason for + + align:start position:0% +here and we'll see a better reason for + + + align:start position:0% +here and we'll see a better reason for +that name this is a dagger is something + + align:start position:0% +that name this is a dagger is something + + + align:start position:0% +that name this is a dagger is something +for the creation operator or the racing + + align:start position:0% +for the creation operator or the racing + + + align:start position:0% +for the creation operator or the racing +operator because it increases some + + align:start position:0% +operator because it increases some + + + align:start position:0% +operator because it increases some +number as you will see and here it's + + align:start position:0% +number as you will see and here it's + + + align:start position:0% +number as you will see and here it's +reflected by this plus but we need a + + align:start position:0% +reflected by this plus but we need a + + + align:start position:0% +reflected by this plus but we need a +little more than that + + align:start position:0% +little more than that + + + align:start position:0% +little more than that +we need a little more commutator than + + align:start position:0% +we need a little more commutator than + + + align:start position:0% +we need a little more commutator than +this + + align:start position:0% + + + + align:start position:0% + +so for example if I would have the + + align:start position:0% +so for example if I would have the + + + align:start position:0% +so for example if I would have the +commutator of a with a dagger to the K + + align:start position:0% + + + + align:start position:0% + +you can imagine this and I wanted to you + + align:start position:0% +you can imagine this and I wanted to you + + + align:start position:0% +you can imagine this and I wanted to you +see you have to become very used and + + align:start position:0% +see you have to become very used and + + + align:start position:0% +see you have to become very used and +very comfortable with this commutation + + align:start position:0% +very comfortable with this commutation + + + align:start position:0% +very comfortable with this commutation +relations and and sometimes the only way + + align:start position:0% +relations and and sometimes the only way + + + align:start position:0% +relations and and sometimes the only way +to do that is to just do example so I'm + + align:start position:0% +to do that is to just do example so I'm + + + align:start position:0% +to do that is to just do example so I'm +doing this with a k here maybe when you + + align:start position:0% +doing this with a k here maybe when you + + + align:start position:0% +doing this with a k here maybe when you +review this lecture you should do it + + align:start position:0% +review this lecture you should do it + + + align:start position:0% +review this lecture you should do it +with k equal 2 or K equal 3 and do it a + + align:start position:0% +with k equal 2 or K equal 3 and do it a + + + align:start position:0% +with k equal 2 or K equal 3 and do it a +few times until you're comfortable with + + align:start position:0% +few times until you're comfortable with + + + align:start position:0% +few times until you're comfortable with +these things and you know what + + align:start position:0% +these things and you know what + + + align:start position:0% +these things and you know what +identities you've been using if if this + + align:start position:0% +identities you've been using if if this + + + align:start position:0% +identities you've been using if if this +was a little quick then go more slowly + + align:start position:0% +was a little quick then go more slowly + + + align:start position:0% +was a little quick then go more slowly +and make absolutely sure you don't how + + align:start position:0% +and make absolutely sure you don't how + + + align:start position:0% +and make absolutely sure you don't how +to do those commentators in here I'm + + align:start position:0% +to do those commentators in here I'm + + + align:start position:0% +to do those commentators in here I'm +going to say what happens you have an a + + align:start position:0% +going to say what happens you have an a + + + align:start position:0% +going to say what happens you have an a +and you have to move it across a string + + align:start position:0% +and you have to move it across a string + + + align:start position:0% +and you have to move it across a string +of a K a hat now moving an A across and + + align:start position:0% +of a K a hat now moving an A across and + + + align:start position:0% +of a K a hat now moving an A across and +a hat because of the commutator gives + + align:start position:0% +a hat because of the commutator gives + + + align:start position:0% +a hat because of the commutator gives +you a factor of 1 but it destroys the a + + align:start position:0% +you a factor of 1 but it destroys the a + + + align:start position:0% +you a factor of 1 but it destroys the a +and the a hat so this as you move the a + + align:start position:0% +and the a hat so this as you move the a + + + align:start position:0% +and the a hat so this as you move the a +across the egg hats because this is a + + align:start position:0% +across the egg hats because this is a + + + align:start position:0% +across the egg hats because this is a +with all the a hats here - the a hat and + + align:start position:0% +with all the a hats here - the a hat and + + + align:start position:0% +with all the a hats here - the a hat and +the a there so if you could just move + + align:start position:0% +the a there so if you could just move + + + align:start position:0% +the a there so if you could just move +the a all the way across then you cancel + + align:start position:0% +the a all the way across then you cancel + + + align:start position:0% +the a all the way across then you cancel +with this what you get is what happens + + align:start position:0% +with this what you get is what happens + + + align:start position:0% +with this what you get is what happens +when you're moving it across and you're + + align:start position:0% +when you're moving it across and you're + + + align:start position:0% +when you're moving it across and you're +moving across a string of those so each + + align:start position:0% +moving across a string of those so each + + + align:start position:0% +moving across a string of those so each +time you try to move on a across a new + + align:start position:0% +time you try to move on a across a new + + + align:start position:0% +time you try to move on a across a new +hat you get this factor of 1 and you + + align:start position:0% +hat you get this factor of 1 and you + + + align:start position:0% +hat you get this factor of 1 and you +kill the a and you kill 1 a dagger so + + align:start position:0% +kill the a and you kill 1 a dagger so + + + align:start position:0% +kill the a and you kill 1 a dagger so +this answer will not have an A and it + + align:start position:0% +this answer will not have an A and it + + + align:start position:0% +this answer will not have an A and it +will have one less + + align:start position:0% +will have one less + + + align:start position:0% +will have one less +a dagger so a dagger to the K minus one + + align:start position:0% +a dagger so a dagger to the K minus one + + + align:start position:0% +a dagger so a dagger to the K minus one +and then I would argue and you should do + + align:start position:0% +and then I would argue and you should do + + + align:start position:0% +and then I would argue and you should do +it in more slowly that you have to go + + align:start position:0% +it in more slowly that you have to go + + + align:start position:0% +it in more slowly that you have to go +across K of those and each time you get + + align:start position:0% +across K of those and each time you get + + + align:start position:0% +across K of those and each time you get +a factor of one and you lose the a and + + align:start position:0% +a factor of one and you lose the a and + + + align:start position:0% +a factor of one and you lose the a and +the a dagger so at the end you get a K + + align:start position:0% + + + + align:start position:0% + +and if you know you should realize that + + align:start position:0% +and if you know you should realize that + + + align:start position:0% +and if you know you should realize that +this is not all that different from the + + align:start position:0% +this is not all that different from the + + + align:start position:0% +this is not all that different from the +kind of commutator you had like P with X + + align:start position:0% +kind of commutator you had like P with X + + + align:start position:0% +kind of commutator you had like P with X +to the N this was very similar it might + + align:start position:0% +to the N this was very similar it might + + + align:start position:0% +to the N this was very similar it might +be a good time to review how that was + + align:start position:0% +be a good time to review how that was + + + align:start position:0% +be a good time to review how that was +done in which that pretty much gives you + + align:start position:0% +done in which that pretty much gives you + + + align:start position:0% +done in which that pretty much gives you +an X to the N minus 1 times a factor of + + align:start position:0% +an X to the N minus 1 times a factor of + + + align:start position:0% +an X to the N minus 1 times a factor of +n because piece had derivative you could + + align:start position:0% +n because piece had derivative you could + + + align:start position:0% +n because piece had derivative you could +almost think of a as the derivative with + + align:start position:0% +almost think of a as the derivative with + + + align:start position:0% +almost think of a as the derivative with +respect to a dagger and then this + + align:start position:0% +respect to a dagger and then this + + + align:start position:0% +respect to a dagger and then this +commutator would be 1 so so this is true + + align:start position:0% +commutator would be 1 so so this is true + + + align:start position:0% +commutator would be 1 so so this is true +and there's also if you want a dagger + + align:start position:0% +and there's also if you want a dagger + + + align:start position:0% +and there's also if you want a dagger +with a to the N right the K this would + + align:start position:0% +with a to the N right the K this would + + + align:start position:0% +with a to the N right the K this would +give you if you had just one of them you + + align:start position:0% +give you if you had just one of them you + + + align:start position:0% +give you if you had just one of them you +will get a minus sign because a dagger + + align:start position:0% +will get a minus sign because a dagger + + + align:start position:0% +will get a minus sign because a dagger +with a is that but the same thing holds + + align:start position:0% +with a is that but the same thing holds + + + align:start position:0% +with a is that but the same thing holds +you're going to get one less a hat so a + + align:start position:0% +you're going to get one less a hat so a + + + align:start position:0% +you're going to get one less a hat so a +hat to the K minus 1 a factor of K + + align:start position:0% +hat to the K minus 1 a factor of K + + + align:start position:0% +hat to the K minus 1 a factor of K +because K times you're going to move an + + align:start position:0% +because K times you're going to move an + + + align:start position:0% +because K times you're going to move an +a dagger across an A and a minus because + + align:start position:0% +a dagger across an A and a minus because + + + align:start position:0% +a dagger across an A and a minus because +you're getting a dagger commutator with + + align:start position:0% +you're getting a dagger commutator with + + + align:start position:0% +you're getting a dagger commutator with +a as opposed to a commutator with a + + align:start position:0% +a as opposed to a commutator with a + + + align:start position:0% +a as opposed to a commutator with a +dagger who just want so these are two + + align:start position:0% +dagger who just want so these are two + + + align:start position:0% +dagger who just want so these are two +very nice and useful equations that you + + align:start position:0% +very nice and useful equations that you + + + align:start position:0% +very nice and useful equations that you +should be comfortable with now this + + align:start position:0% +should be comfortable with now this + + + align:start position:0% +should be comfortable with now this +implies that you can do more with the N + + align:start position:0% +implies that you can do more with the N + + + align:start position:0% +implies that you can do more with the N +operator so + + align:start position:0% +operator so + + + align:start position:0% +operator so +n with a hat to the K this time will be + + align:start position:0% +n with a hat to the K this time will be + + + align:start position:0% +n with a hat to the K this time will be +minus K a hat to the K it doesn't change + + align:start position:0% +minus K a hat to the K it doesn't change + + + align:start position:0% +minus K a hat to the K it doesn't change +the number of a hat because you're now + + align:start position:0% +the number of a hat because you're now + + + align:start position:0% +the number of a hat because you're now +complete + + align:start position:0% +complete + + + align:start position:0% +complete +baking commentators with a dagger a so + + align:start position:0% +baking commentators with a dagger a so + + + align:start position:0% +baking commentators with a dagger a so +each time you have this commuted with + + align:start position:0% +each time you have this commuted with + + + align:start position:0% +each time you have this commuted with +one a hat the a dagger and the a if you + + align:start position:0% +one a hat the a dagger and the a if you + + + align:start position:0% +one a hat the a dagger and the a if you +want but you have another a back so the + + align:start position:0% +want but you have another a back so the + + + align:start position:0% +want but you have another a back so the +power is the same the sign comes from + + align:start position:0% +power is the same the sign comes from + + + align:start position:0% +power is the same the sign comes from +this sign so yes it should have a heart + + align:start position:0% +this sign so yes it should have a heart + + + align:start position:0% +this sign so yes it should have a heart +and sorry yes + + align:start position:0% + + + + align:start position:0% + +and similarly n a hat dagger to the K + + align:start position:0% +and similarly n a hat dagger to the K + + + align:start position:0% +and similarly n a hat dagger to the K +this is K a hat dagger to the K so what + + align:start position:0% +this is K a hat dagger to the K so what + + + align:start position:0% +this is K a hat dagger to the K so what +happened before that the end operator + + align:start position:0% +happened before that the end operator + + + align:start position:0% +happened before that the end operator +and hot operator leaves the a the same + + align:start position:0% +and hot operator leaves the a the same + + + align:start position:0% +and hot operator leaves the a the same +at puts a number leaves the a dagger the + + align:start position:0% +at puts a number leaves the a dagger the + + + align:start position:0% +at puts a number leaves the a dagger the +same and puts a number here you see it + + align:start position:0% +same and puts a number here you see it + + + align:start position:0% +same and puts a number here you see it +happening again and with a collection + + align:start position:0% +happening again and with a collection + + + align:start position:0% +happening again and with a collection +with a string of a hat gives you the + + align:start position:0% +with a string of a hat gives you the + + + align:start position:0% +with a string of a hat gives you the +same string but the number and with a + + align:start position:0% +same string but the number and with a + + + align:start position:0% +same string but the number and with a +collection of a daggers gives you the + + align:start position:0% +collection of a daggers gives you the + + + align:start position:0% +collection of a daggers gives you the +same collection of a daggers with a + + align:start position:0% +same collection of a daggers with a + + + align:start position:0% +same collection of a daggers with a +number and the number happens to be the + + align:start position:0% +number and the number happens to be the + + + align:start position:0% +number and the number happens to be the +number of A's or the number of a dieters + + align:start position:0% +number of A's or the number of a dieters + + + align:start position:0% +number of A's or the number of a dieters +so that's the reason it's called a + + align:start position:0% +so that's the reason it's called a + + + align:start position:0% +so that's the reason it's called a +number operator because the eigenvalues + + align:start position:0% +number operator because the eigenvalues + + + align:start position:0% +number operator because the eigenvalues +are the number of creation operators or + + align:start position:0% +are the number of creation operators or + + + align:start position:0% +are the number of creation operators or +the number of destruction operators I + + align:start position:0% +the number of destruction operators I + + + align:start position:0% +the number of destruction operators I +was a little + + align:start position:0% +was a little + + + align:start position:0% +was a little +glib by calling it the eigenvalue but it + + align:start position:0% +glib by calling it the eigenvalue but it + + + align:start position:0% +glib by calling it the eigenvalue but it +almost looks like an eigenvalue equation + + align:start position:0% +almost looks like an eigenvalue equation + + + align:start position:0% +almost looks like an eigenvalue equation +which have an operator another operator + + align:start position:0% +which have an operator another operator + + + align:start position:0% +which have an operator another operator +and your number times the second + + align:start position:0% +and your number times the second + + + align:start position:0% +and your number times the second +operator it's not exactly an eigenvalue + + align:start position:0% +operator it's not exactly an eigenvalue + + + align:start position:0% +operator it's not exactly an eigenvalue +equation though because eigenvalues you + + align:start position:0% +equation though because eigenvalues you + + + align:start position:0% +equation though because eigenvalues you +would just have this acting on the + + align:start position:0% +would just have this acting on the + + + align:start position:0% +would just have this acting on the +second one but the fact that this case + + align:start position:0% +second one but the fact that this case + + + align:start position:0% +second one but the fact that this case +appear here are the reason these are + + align:start position:0% +appear here are the reason these are + + + align:start position:0% +appear here are the reason these are +called number operators so what's a + + align:start position:0% +called number operators so what's a + + + align:start position:0% +called number operators so what's a +little quick for many of you some you + + align:start position:0% +little quick for many of you some you + + + align:start position:0% +little quick for many of you some you +may have seen this before with a little + + align:start position:0% +may have seen this before with a little + + + align:start position:0% +may have seen this before with a little +slow but the important thing is after a + + align:start position:0% +slow but the important thing is after a + + + align:start position:0% +slow but the important thing is after a +couple of days from now or by Friday you + + align:start position:0% +couple of days from now or by Friday you + + + align:start position:0% +couple of days from now or by Friday you +find all this very straightforward \ No newline at end of file diff --git a/l-BNoAPe6qo.txt b/l-BNoAPe6qo.txt new file mode 100644 index 0000000000000000000000000000000000000000..795ec4a561d159b8a533afdd7575ed0009eb7696 --- /dev/null +++ b/l-BNoAPe6qo.txt @@ -0,0 +1,2426 @@ +The following content is +provided under a Creative + +Commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high quality educational +resources for free. + +To make a donation or view +additional materials from + +hundreds of MIT courses, visit +MIT OpenCourseWare at + +ocw.mit.edu. + +PROFESSOR: So, our first +question here is about + +limiting reactants. + +So, that's something you will +encounter in your review + +reading for the sections, that +kind of review -- what we hope + +you have picked up from high +school or will pick up quickly + +by doing some review. + +So, how about we have everyone +take ten more seconds on the + +clicker question, get your +final answer in here. + +All right. + +So, let's see what we have. + +All right, so it looks like +we weren't showing the + +percentages here, but it looks +like hopefully most of you + +were able to get the correct +answer of H2 being the + +limiting reactant. + +It looks like we're still +figuring out -- this room was + +just renovated, we're still +working out exactly how the + +electronics work. + +So, normally we'll see a +percentage of how many of you + +got it, but I'm going to say it +was probably about 95% got + +the answer right. + +So, good job there. + +If you didn't get the answer +right -- we'll send these + +questions to your TA, so any +time you get a clicker + +question wrong and you're +confused, bring it up in the + +next recitation section +and you'll be able + +to discuss it there. + +So, starting in, we can switch +over to the to the notes now. + +When we left off on Wednesday, +what we had really been doing + +is trying to give you an +overview of all of the + +different topics that +we're going to be + +going over this semester. + +And also, to make a couple of +those connections between the + +principles we're learning, and +some of the exciting research + +that's going on at MIT in the +Chemistry Department, and + +also, to give you the idea that +we are going to be trying + +to make these connections +between the chemistry and + +things like human health +or medicine. + +So, now we get to actually take +a step back and start at + +the beginning, because before we +can talk about some of the + +more complex issues, which +involve interactions between + +molecules reacting or even +when we're talking about + +individual molecules -- the +bonds that form between + +individual atoms -- before any +of that we actually need to + +establish a way that we're going +to describe and think + +about how an individual +atom behaves. + +And the way that we'll do this +is starting with talking about + +the discovery of the electron +and the nucleus here. + +Once we go through that, we +will be able to talk about + +describing an atom using +classical physics. + +So, once we have an atom and a +nucleus, what we'll try to do + +is apply the classical +mechanics to + +explain how that behaves. + +What we'll find is that this +fails, and once this fails + +we're going to need +another option. + +Luckily for us, we have quantum +mechanics, which we'll + +be talking about for the +next few lectures, and + +we'll dive into that. + +We might get a chance to +introduce it today, but + +certainly in next class we'll +be introducing this new kind + +of mechanics that's going +to allow to describe + +the behavior of atoms. + +So, I want to point out that it +makes a lot of sense for us + +to start with the discovery of +the electron and the nucleus, + +because it really highlights +one of the big issues that + +comes up in all chemistry +research that you do, and that + +is how do we actually study, +or in this case, how do we + +discover atoms or sub-particles +that we actually + +can't see at all. + +And there are lots of solutions +that chemists come + +up with -- there's always new +techniques that allow us to do + +this, and these are just some +of the first, and we'll go + +through them in a little +bit of detail here. + +So, this all starts, in terms +of putting it in its + +historical context at the turn +of the Century, we said we'd + +start right in on the +20th Century of + +where chemistry was. + +And where we where at the start +of the 20th Century in + +the late 1890's is that we were +at a place where there + +was great confidence in our +understanding of the universe, + +and our understanding of +how all matter worked. + +So, people in the chemistry +community and in the physics + +community had this general +feeling that the theoretical + +structure of the entire universe +was pretty well + +understood. + +And they had this feeling +because there had just been + +this huge boon of discovery, +of scientific advances that + +included Newtonian mechanics, +it included Dalton's atomic + +theory of matter, also +thermodynamics and classical + +electromagnetism. + +So, you can understand they +really felt quite confident at + +this time that we could explain +everything that was + +going on, and in fact, a really +telling quote from the + +time was said by a professor at +the University of Chicago, + +and what he said is, "Our future +discoveries must be + +looked for in the sixth +decimal place." + +So, basically what he's saying +here is we pretty much + +understand what's going on, +there's nothing new to really + +discover, all we need to do is +measure things more precisely. + +So, that's not exactly the case, +and we're going to start + +in at the point where right +around this time of great + +confidence of feeling all has +been conquered, there are some + +observations and discoveries +that are made that completely + +break down these theories. + +For example, in terms of the +atomic theory of matter, at + +the time at the turn of the +Century, the understanding was + +that atoms were the most basic +constituent of matter, meaning + +you couldn't break atoms up into +anything smaller -- that + +was it, you're done. + +And with using Newtonian +mechanics, it was assumed + +since this type of mechanics +worked so well to describe + +everything we could see, it +could even describe the + +universe and planets, that, of +course, we could use Newtonian + +mechanics to describe how an +electron -- actually, we + +didn't even know about an +electron here, but how atoms + +behaved, and it turns out this +is not the case, and the first + +step in discovering this is not +the case, was accomplished + +by J.J. Thomson, and J.J. +Thomson is credited for + +discovering the electron. + +He was a physicist in England, +and what his laboratory was + +studying is something called +cathode rays, and cathode rays + +are simply rays that are emitted +when you have a high + +voltage difference between +two electrodes. + +So, if you look at this set up, +what he did when he was + +studying these rays is he had +an evacuated tube, which is + +schematically shown here, where +it's evacuated of all + +it's air and filled instead just +with hydrogen gas, and he + +had this high voltage difference +between an anode + +and a cathode, and he actually +put a little hole in the anode + +here, so these cathode rays that +were produced could shoot + +out of the cathode and actually +could be detected as + +this luminescent spot on +a detector screen. + +So, lots of people were studying +cathode rays at the + +time -- one reason is they +actually gave off this bright + +glow -- if you put them in an +evacuated glass tube, you got + +these crazy patterns +and glowing colors. + +So, for that reason +it was a very hot + +issue in terms of research. + +But also, no one really knew +what these were and Thomson + +was seeking to figure out some +more properties of them, and + +he had the theory that maybe +they were actually charged + +particles of some sort, and +others had proposed this in + +the past, but they didn't really +have an experimental + +set up to test it. + +And that's what Thomson did. + +And what we did was he put two +detection plates on either + +side of these cathode rays, +and when he put a voltage + +difference between these two +plates, he wanted to see if he + +could actually bend the rays and +test if they're actually + +charged or not. + +So, when the voltage difference +between the plates + +is zero, or when we just don't +have the plates there at all, + +the cathode rays are not bent, +they just go right in a + +straight line, and they can be +detected on this screen. + +When he actually cranked up the +voltage between these two + +plates, what he saw was really +amazing to him, which is that + +he actually was able to bend +these rays -- this had never + +been observed before in any +capacity, and he was able to + +detect on his screen that there +was this deflection, and + +he could even measure +the degree of the + +deflection that he had. + +So, we know now that we have +charged particles. + +Are these negatively or +positively charged, based on + +this evidence? + +STUDENT: Negatively. + +PROFESSOR: Yeah, that's right. + +So, what we have here, cathode +rays we now know are + +negatively charged particles. + +And, in fact, he named these +negatively charged particles. + +Does anyone know what +he named them? + +No, not electrons -- +very good guess. + +He named them corpuscles. + +Has anyone heard +of corpuscles? + +A little bit. + +Yeah, so it was later named that +these particles were, in + +fact, electrons, and that's +what they are. + +J.J. Thomson continued to call +them corpuscles for many, + +many, many years after everyone +else called them + +electrons, but I'm sure no one +minded because he did, in + +fact, discover them. + +And he was actually able to find +out more than just that + +these were charged. + +From classical electromagnetism, +he could + +actually relate the degree of +deflection that he saw to the + +charge and the mass +of the particles. + +So, using that he could say that +delta x, and we'll put + +sub-negative, because we know +now that these are negative + +particles, is proportional to +the charge on that particle + +over m, which is the mass. + +So, we have e being equal to +the charge of the negative + +particles, and m, of course, +is equal to the + +mass of those particles. + +So, Thomson didn't stop here, +he actually continued + +experimenting with different +voltages. + +And what he found was if he +really, really ramped the + +voltage up between those two +plates, he could actually + +detect something else. + +And what he could detect here is +that there was this little + +spot of luminescence that he +could see on the screen that + +was barely deflected at all -- +certainly in comparison to how + +strongly this first particle +was deflected. + +The second particle was +deflected almost not at all. + +But what he could tell from +the fact that there was a + +second particle at all, and the +fact that it was in this + +direction, is that in addition +to his negative particle, he + +also, of course, had a positive +particle that was + +within this stream of rays +that were coming out. + +So, of course, he can use the +same relationship for the + +positive particle, so delta +x now of the positive is + +proportional to the charge on +the positive particle all over + +the mass of the positive +particle. + +So, this is interesting +for several reasons. + +What did he manage to pull out +information-wise from using + +these two relationships? + +And actually to do this, he made +a few more observations. + +The first, which I just stated, +is that the deflection + +of that negative particle was +just far and away more + +extreme, much, much larger +than that of + +the positive particle. + +The other assumption that he +made here is that the charge + +on the two particles +was equal. + +So, how could he know that +the charge on the two + +particles was equal? + +And actually he couldn't exactly +know it -- it was a + +very good assumption that he +made, and he could make the + +assumption because he, in fact, +did know that what he + +started with was this +hydrogen gas. + +So, he was starting +with hydrogen. + +If some negative particle was +popping out from the hydrogen, + +then what he must be left with +is h-plus, and since hydrogen + +itself is neutral, the h-plus +and the electron had to add up + +to be a neutral charge. + +So, that means the charges of +the two pieces, the positive + +and negative particle, +must be equal in + +terms of absolute charge. + +So, using this relationship, he +could then actually figure + +out by knowing, which he knows +how much each of them were + +deflected, he could now try to +think about whether or not he + +could make some relationship +between the masses -- between + +the mass of the positive and +the negative particle. + +So, this relationship he was +looking at was starting with + +the deflection, and the absolute +distance that the + +particles were deflected. + +So, what he could set that equal +to is he knows what x is + +proportional to in terms of +the negative particle, so + +that's just the absolute value +of the charge over the mass of + +the negative particle. + +He could divide all of that by +the absolute value of the + +charge of the positive particle, +all over the mass of + +the positive particle. + +And as we said, he made the +assumption that those two + +charges were equal, so +we can go ahead and + +cross those right out. + +So, what that told him was if +he knew the relationship + +between how far they were each +displaced, he could also know + +something about the + +relationship of the two masses. + +So essentially, there was an +inversely proportional + +relationship between how far the +particles were displaced, + +and what the mass of the two +particles turned out to be. + +So, because he, of course, +observed that the negative + +particle travelled -- it was +deflected much, much further + +by those plates, what he could +also assume and make the + +conclusion of is that the mass +of that negative particle is + +actually larger or smaller? + +STUDENT: Smaller. + +PROFESSOR: Much, much smaller, +exactly, then the mass of the + +positive particle. + +So essentially, what he found +here is the relationship + +between the mass of an electron +and the mass of the + +rest of the atom, the rest of +the hydrogen atom there, which + +is an ion in this case. + +And, in fact, it's so much +smaller, it's close to 2,000 + +times smaller, that we can +make the assumption that + +essentially the electrons +take up no mass. + +I mean they take up a teeny +bit, but essentially, when + +we're thinking about the set up +of the atom, we don't have + +to account for them as using +up a lot of the mass we're + +discussing. + +So, Thomson came up with a +model for the atom due to + +this, and this is called the +Plum Pudding model of the + +atom, and he was, as we said, +English, so plum pudding is + +kind of a British food. + +Has anyone here ever +had plum pudding? + +A couple of people. + +Okay. + +I've never even seen it, so +that's good -- you must be + +better travelled than I. + +So, the idea that he had here +was he treated the whole of + +the atom as sort of this +positive pudding, so the + +majority of the atom was just +kind of this goopy, positive + +stuff that you could think +about, and within the pudding, + +he had all these negative +charges, which were the + +electrons, and they were the +raisins or the plums that were + +in the pudding. + +So this was a revolutionary +model of an atom when we + +thought of the fact that before +this experiment, the + +understanding was an atom could +not be divisible into + +smaller parts, and now here we +are with subatomic particles + +with electrons, and this +wonderful Plum Pudding model. + +So, for those of you that +haven't actually had plum + +pudding, which myself +is included, I threw + +a picture up here. + +This was my first glance at plum +pudding, and I guess you + +can see that this must be that +positive part -- most of the + +plums are within that, and you +can see all these little + +raisins or plums in here, that +would be that negative charge. + +So, that already was a big +advancement from where the + +understanding was at the time. + +We already moved way forward and +completely revolutionizing + +the understanding of an atom in +that there's something in + +an atom -- it's not the smallest +thing there is. + +However, as you know, we +didn't stop at the plum + +pudding model, which is good, +because it's a little goofy, + +so it's nice to move on from +that and move on we did. + +About 10 to 15 years later, +another physicist, Ernest + +Rutherford, actually put this +plum pudding model to test, + +and he did it through studies +that he'd been doing on + +radiation that was emitting +something + +called alpha particles. + +So, Rutherford, some of you may +recognize that name, is a + +very famous physicist who made +a lot of contributions in + +terms of radioactivity. + +When he was studying these +alpha particles, he was + +actually the first person to +identify the difference + +between different types of +particles that radioactive + +materials emit. + +And he got this particular +material that he was studying, + +radium bromide from his good +friend, Marie Curie, who, + +obviously, also was a leader, +really the leader in figuring + +out much of how radioactive +materials work. + +She has two Nobel Prizes +for her work + +in radioactive materials. + +And something that maybe many +of you think, which I know I + +always think when I hear about +radioactivity studies in the + +early 1900's, is oh, my gosh, +this sounds really dangerous, + +right, they're using radium +bromide, and this is pretty + +dangerous radioactive +material. + +So, for those of you that don't +know radium is extremely + +radioactive, even in the range +of radioactivity, and one of + +the major problems with it is +that if it does get in your + +body, the radium is treated +as calcium in your body. + +So, you can imagine what happens +as it gets deposited + +into your bones, which is not +the ideal situation after a + +long day in the lab. + +So, this is really a pretty +dangerous situation that's + +always interesting +to point out. + +He got this from Marie Curie -- +you can imagine they used + +the postal service, I'm not sure +how else they would have + +transferred it to each other. + +So, it really brings +up some issues. + +The first thing I did when I +heard that is actually look up + +to see how, in fact, Ernest +Rutherford did die in 1937, + +and you'll be happy to know, +it actually wasn't from + +radiation poisoning or from bone +cancer, so that's really + +good that that worked out okay +for him, and that he did get + +to, sort of safely, at least +end his life before the + +radiation ended it. + +But it's really interesting +the studies that he did do + +with radium bromide, and he was + +studying the alpha particles. + +And what was known about alpha +particles at the time is that + +they were these charged +particles and that they were + +very heavy. + +Does anyone know more than what +Rutherford knew at the + +time, what alpha particles +actually are? + +Yeah, good. + +So, they're actually helium +atoms, helium ions. + +And this wasn't really important +for the studies, it + +didn't matter that didn't know +what they are, but it's nice + +to kind of know now -- that we +do know what they were using. + +And he was doing quite a +few studies with them. + +One experiment that he was doing +is detecting the number + +of particles that were being +emitted by this radium bromide + +as a rate, so he would measure +the number of particles per + +minute that the radium +bromide was emitting. + +And what he used was a detector +here, so he here + +could detect how many +particles were + +hitting this detector. + +He had actually developed this +detector with a postdoc by the + +name of Hans Geiger. + +Does that name ring a bell? + +STUDENT: Geiger counter. + +PROFESSOR: Um-hmm, +a Geiger counter. + +So, this, in fact, is my very +schematic representation of a + +Geiger counter. + +For those of you don't know what +that is, it's simply an + +instrument that counts +radioactive particles in the + +air, and now that you're at MIT, +you'll all have a chance + +to see one first hand, if you're +ever in any of the + +labs, especially in the +chemistry or bio labs. + +As carefully as people work with +radioactivity here, and + +using often much, much safer +radioactive materials than + +radium bromide, and using them, +and special hoods, and + +having special procedures, +they still do a lot of + +checking with these Geiger +counters to make sure + +everything's safe. + +You'll actually see a man +walking around with one, + +sometimes in the halls, just +kind of like this -- you hear + +that click, click, click. + +That's a good sound, it means +low levels of radiation. + +He'll walk by your hood, so +click by your hood -- + +I always get a little nervous +when he walked by my hood, I + +don't know why, I never worked +with radioactive material. + +But I was convinced +I'd hear the + +click-click-click-click-click, +which is what tells you you're + +in trouble. + +So, I've never heard the +click-click-click-click-click, + +and we might bring a Geiger +counter in here some time + +later in the semester so we can +check all of you out, and + +hopefully we won't hear any +when we do that either. + +So, one thing that he discovered +with this detector + +initially, and he was the first +to discover this, is + +that radioactive material, +including radium bromide, have + +a characteristic rate that they +emit, radioactive decay. + +So basically they're decaying +at a constant rate, which + +means, of course, that you can +figure out how old things are + +by seeing how much +they've decayed. + +So, he was really the first +person to discover you could + +do this, which was used to make +the first somewhat close + +approximation of the +age of the earth. + +So that's a pretty exciting +set of experiments he did. + +But one thing that he wanted +to do specific to + +understanding the atom, and +using these alpha particles, + +these heavy-charged particles, +was to test if this Plum + +Pudding model actually fit +what he could observe. + +So, what he did was he first +recorded the count rate of + +radium bromide before it's going +through any kind of a + +plum pudding atom, and he found +that it had a count rate + +of 132,000 alpha particles per +minute were being detected by + +this Geiger counter. + +He then set up a situation where +he put a very, very thin + +piece of gold foil right in what +would be in the stream of + +the alpha particles. + +So, it was only 10 to the +negative, 9 meters thick, so + +about one nanometer, so that's +really thin, it's thinner than + +a strand of hair. + +So you can imagine, we actually +don't need to think + +of it as a piece of gold foil, +it might be easier to think of + +it as a couple of +layers of atoms. + +So basically he's trying to put +some atoms in the way of + +the alpha particle. + +And what he would expect is if +this Plum Pudding model is + +true, nothing's really going +to happen to the particles, + +right, they should go straight +through, because if they hit + +an electron, those +are so small. + +We figured out the mass is so +tiny that it shouldn't really + +deflect them very much. + +And, of course, all that's left +is this positive pudding. + +So that's not going to +do anything either. + +And what he found when he did +this experiment, was that the + +count rate with still 132,000 +counts per minute. + +So, what he could conclude thus +far was that this was + +really consistent with the +Plum Pudding model. + +All of his heavily-charged alpha +particles were going + +right through this thin +layer of gold atoms. + +So, you might think that he +would stop his experiments + +here, and maybe he would have, +but as I mentioned, he did + +have a postdoc working with +him by the name of Geiger. + +He also had an undergraduate, we +could say maybe even a UROP + +working with him, and this was +by the name of Marsden was the + +name of this UROP. + +And Rutherford realized, you +know I have these two people + +that are very excited to work on +this project, I don't need + +to spend time doing it. + +Maybe it's not the best way for +me to spend time looking + +to see if I can find any +bounced-back particles since + +all the particles are +accounted for. + +But, you know, this +undergraduate's very eager to + +do it, let's let +him have a try. + +And something you might find in +your UROP experience is you + +have a unique advantage as an +undergraduate, which is that + +there's not a lot of pressure +to actually make a huge + +discovery or necessarily +accomplish a great amount. + +You have a little more pressure +in grad school, but + +sometimes that means when +you're an undergrad your + +advisor will decide to put you +on projects that maybe when + +you look at them seem +a little bit silly. + +So this project was, let's see +if we can detect any alpha + +particles by making a detector +that swings around. + +So, some people might say, +why are we doing this? + +We know we started with a +132,000 alpha particles. + +We detected a 132,000 +alpha particles. + +What are we even looking for? + +We have to build this whole new +detector, is this really + +the best use of my time? + +As an undergrad, you don't have +to worry about it, you're + +just worried about learning. + +You can take these big risks of +time, and if at the end of + +the day there's nothing to +detect, you still know how to + +build a detector. + +So, keep that in mind if +you're not over-the-top + +excited about the prospects +of some of your research. + +You might be surprised +at what you find out. + +And this is exactly what +happened with Marsden who + +discovered that when he shot +the alpha particles at the + +gold foil, he detected something +on his detector that + +click, click, click went +a little bit faster. + +So, what he detected was that +there were 20 alpha particles + +per minute. + +Does that sound significant? + +It depends, right? + +So hopefully, the first +experiment he did, which I + +know that they certainly did +do was maybe it's just + +background noise, right? + +So, they took away that gold +foil and said is just the + +alpha particles hitting +it some other way? + +And no, it wasn't. + +When he took away the gold +foil, the count rate + +went down to zero. + +If he switched from gold to +let's say iron, he also tried + +platinum, a number of different +foils, he found that + +they count rate, it still was 20 +alpha particles per minute. + +So, this is an absolutely +outstanding discovery, even + +though, if we think about it, +what is the probability that + +this happened, how often +did this happen? + +It actually almost happened +not at all. + +We can figure out exactly what +the probability of this + +backscattering was just by +dividing the count rate of the + +number particle that were +backscattered divided by the + +count rate of the incident +particles. + +So essentially, we just +have 20, and our 20 + +is divided by 132,000. + +So, we end up with a not so +large probability of 2 times + +10 to the negative 4. + +But still, we can't even +overstate how exciting this + +discovery was. + +Rutherford, the advisor here, +he had a lot of good things + +happen in his life, +as I mentioned. + +He was the person responsible +for being able to first date + +the age of our earth. + +That's a pretty nice thing. + +He was also married, he had a +child, which I hear is very + +nice, very exciting, also. + +But yet, when he saw this one +single experiment from this + +undergraduate, he described this +as the most incredible + +event that had ever happened +to him in his life. + +So, this was a pretty +big deal. + +We won't tell his daughter. + +And he gave a very good analogy +in saying, "It was + +almost as incredible as if you'd +fired a 15 inch shell at + +a piece of tissue paper, and +it came back and hit you." + +And that really illustrates +what's happening here, because + +if we think of the Plum +Pudding model, it's + +essentially this very thin film, +right, there's nothing + +that should hit if we send alpha +particles through it. + +But what we actually +have is that + +something's bouncing back. + +So, what happened is Rutherford +needed to come up + +with a new model for the atom +with several interpretations + +that came out of these +experiments, and some of these + +interpretations were that, of +course, we now know that these + +gold atoms, they must be mostly +empty, and the reason + +that we know that they must be +mostly empty is because all + +but 20 of these 132,000 +particles + +went all the way through. + +So they weren't hitting +anything, we're dealing with + +mostly empty space. + +But he also realized that when +they did hit something, what + +they hit what unbelievably +massive, but also that that + +mass was concentrated into this +very, very small space. + +So eventually, this is what we +have come to call the nucleus + +of an atom. + +And the nucleus name was used +as an analogy to the nucleus + +of a cell, so in some ways that +makes it easier to see + +the connection, but I think it +can also be a little bit + +confusing for maybe 7th graders +that are learning both + +at the same time, that this +nucleus acts very different + +from a nucleus in a cell, +although, of course, there + +many of them in the +nucleus of a cell. + +There are some other things that +Rutherford was able to + +figure out. + +One is the diameter of the +nucleus, and that turns out to + +be 10 to the negative +14 meters. + +If we think about the size of +a typical cell -- excuse me, + +now I'm getting confused +about nuclei. + +If we think of the size of a +typical atom, we would say + +that would be about 10 to +the negative 10 meters. + +So, we can see the diameter +of a nucleus is absolutely + +smaller, really concentrating +that mass into + +a very small space. + +So, you might be asking +how did he + +actually figure that out? + +We'll do the calculation +ourselves. + +In fact, we'll do the whole +experiment ourselves, minus + +the radioactivity in just a +minute, so we'll be able to + +answer that question for you. + +He also figured out that +the charge of the + +nucleus was a plus ze. + +This makes sense intuitively as +well, because z is just the + +atomic number. + +So, let's say we have an atomic +number of 3, that means + +we have 3 electrons, so we +better hope to get our neutral + +atom that we have a charge +of plus 3 in the nucleus. + +So, I mentioned at the +beginning, while he was + +working with this radium +bromide, that I was very + +relieved to see that it did +not kill him to do these + +experiments. + +However, I think I will share +with you that the cause of his + +death was, in fact, related to +his research here, even though + +it was a little more +tangled up. + +So, what happened, of course, +after he discovered the + +nucleus, not surprising, he won +a Nobel Prize for this -- + +I would hope that he would. + +And in addition to winning a +Nobel Prize, he was also + +knighted, which was a nice +bonus for someone born in + +England, that's a great thing +to happen to them. + +The problem that he ran into is +at some point a little bit + +later in his life, he had a +hernia which was a pretty + +standard case, but what he +was going to need was an + +operation on it. + +And the glitch came that at +least at the time, if you were + +a knight, you could only be +operated on by a doctor that + +was also titled. + +So, Rutherford had a little bit +of waiting to do for that + +doctor to show up, and it turns +out the wait was too + +long, and he actually passed +away because he discovered the + +nucleus and got a Noble Prize +and became knighted. + +So, it's still dangerous. + +If that opportunity comes up +for you, maybe you want to + +check into the policies of how +that works with the doctor + +situation now. + +Hopefully they've cleared +it up a little bit. + +So, what we want to do now is +see if we can understand how + +this backscattering +experiment worked. + +So, we will do our own +backscattering experiment. + +And we'll ask you to imagine +a few things. + +First is that we have this mono +layer of gold particles. + +So let's see if Professor +Drennan is able + +to help us out here. + +Oh, great. + +So, that is her daughter, Sam +that you see strapped to the + +chest, and Dr. Patti Christie +helping us out here. + +All right. + +So, we'll move this up to the +front in just a minute, but + +I'm going to explain how this +experiment works, and we'll do + +the calculation first before +the excitement breaks out. + +But I'm sure you can easily see +how these styrofoam balls + +could, in fact, be a mono +layer of gold nuclei. + +We have 266, as some of you +might know who saw me counting + +ping-pong balls the other +day in office hours. + +We have 266 ping-pong balls, and +we need someone, hopefully + +you, to be some radioactive +material that are going to be + +emitting these ping-pong +balls. + +And when the time comes, in just +a minute, I'll ask the + +TAs to come down and hand these +out very quickly to you, + +so we can do this experiment. + +But first, let's go through how +we're going to determine + +what Rutherford determined, +which was he was interested in + +knowing, which we said +what the diameter + +of the nuclei were. + +So, we're going to do the same +thing and figure out the + +diameter of these styrofoam +balls here, and we can do it + +by using the relationship +of how many backscatter. + +So, if we think about the +probability of backscattering, + +which is the exact same thing +that we saw Rutherford + +calculate, using the 20 +divided by 132,000. + +But in our case, the probability +of backscattering + +is going to be the number of +balls that backscatter, and + +that's going to be divided +by the total number + +of ping-pong balls. + +So, do you remember +what that was? + +STUDENT: 266. + +PROFESSOR: 266. + +Good information retention. + +All right. + +So, we have the probability +here. + +So, in terms of the number of +balls scattered over the + +total, we can also relate the +probability to the area of all + +of those nuclei divided +by the total area that + +the atoms take up. + +Right, this makes a lot of +sense, because if the entire + +atom was made up of nuclei, +then we would have 100% + +probability of hitting one of +these nuclei and having things + +bounce back. + +So, here we have the area of +the nuclei we'll figure out + +adding those all together versus +the space of all of the + +atoms put together. + +So, not only did Professor +Sayer, who's in the Chemistry + +Department who put together this +contraption for all of + +you, not only did she magnify +the size of these gold nuclei, + +but she actually had to smoosh +all of these atoms closer + +together then they normally +would be. + +If, in fact, a gold nucleus was +this size here, we would + +need to use another lecture hall +in order to find a place + +to put this nucleus +right here. + +This is a little bit of a +tricky experiment, so we + +decided we'll just smoosh it all +in, and we'll actually be + +able to account for it, because +we'll take into + +account the area of all +of those atoms. + +I think this board does not +like to go by itself. + +All right. + +So we can figure out what that +is, the area of all of the + +nuclei is going to be the number +of nuclei times the + +area per nucleus, and we're +going to talk about the + +cross-section here to +keep it simple. + +And all of that is divided +by the area of the + +atoms, which is 1 . + +39 meters squared, measuring +that space there. + +So, the number of nuclei, if we +were to sit and count these + +as well, is 119. + +So, we'll multiply that by just +pi, r squared, to get + +that cross-section, and divide +all of that by 1 . + +39 meters squared. + +So, what we have here is a +relationship that can tell us + +what the probability of +backscattering is, but what we + +want to pull out, since we can +experimentally measure what + +the probability is, what we need +to pull out is the radius + +or the diameter of these +nuclei, so we can just, + +instead of solving for p, we can +switch it around and solve + +for the radius. + +So, that's going to be equal to +the probability raised to + +the 1/2 times 6 . + +098 times 10 to the +negative 2 meters. + +So, actually, just for +discussion sake, it makes a + +little more sense for us to talk +about the diameter, so + +that's just twice the radius. + +So, once we figure out what +our probability of + +backscattering is, we'll just +raise that to the 1/2, and + +we'll multiply that by 12 . + +20 centimeters. + +All right. + +So now all we have to do is +figure out this probability of + +backscattering. + +We know we need to divide by +266, but what we need you to + +help us with is to figure out +this top number here and see + +how many particles are +going to backscatter. + +So, if the TAs can come up +and quickly hand out + +1 particle to everyone. + +And a few people will need to +throw 2, if you feel like you + +have particularly good aim. + +PROFESSOR: So, as you're getting +your ping-pong balls + +-- do not throw them yet. + +Let me explain to you +what constitutes + +a backscatter event. + +So, it'll be considered a +backscatter event if your + +ping-pong ball hits +one of the nuclei. + +It's not going to be a +backscatter event if your + +ping-pong ball hits +the frame or these + +strings, or the top part. + +So, in a few minutes, not now, +we're going to ask you to + +stand up, and you can kind of +come over more toward the + +center of the room if you want, +and aim your ping-pong + +ball at the lattice here, follow +the ping-pong ball with + +your eye, and discover, watching +it, whether it's a + +backscatter -- it hits one of +the nuclei and bounces back + +towards you, or if it goes +through, and also if your + +ping-pong ball doesn't land +anywhere in the vicinity of + +this at all, then keep +that in mind. + +And then at the end of the +experiment we'll ask you what + +happened to your ping-pong ball, +and you'll let us know, + +and we can calculate the number +of backscatter events. + +Are there any questions +before we get started? + +Raise your hand if you don't +if you don't have a + +ping-pong ball yet. + +Any questions before +we get started? + +All right. + +So, we'll come around and +get ping-pong balls + +to the rest of you. + +Those of you who have your +ping-pong balls can now begin + +the experiment. + +[EXPERIMENTING] + +PROFESSOR: All right. + +Any last shots? + +There we go. + +All right. + +So, it looks like we were a +little bit successful, I saw + +some backbouncing. + +We were going to have a clicker +slide on how many + +bounced back, but it looks like +we're having a little + +technical difficulty +with that. + +So, what I'll ask is can you +stand up if you had your + +particle bounce back? + +All right, so let's count +how many we have here. + +So, 13 backscattered. + +TAs, if you can maybe pick up +these ping-pong balls for me. + +I'm sure it would be very +amusing if I fell, but I'd + +rather not. + +All right, so, we have +13 divided by 266. + +All right, MIT students, who +has a calculator on them? + +Actually, I should probably do +it as well, so I know I'm + +hearing correctly. + +So, are you getting 0 . + +0489 or so? + +All right. + +So, we've got our probability. + +We can go ahead and plug that +in, take the square root of + +it, multiply it by 12 . + +2. + +What are you getting +for your diameters? + +Yup, that's what I got, too. + +All right. + +So, we have 2 . + +70 for our diameter, and +that's in centimeters. + +So, we actually did a pretty +good job here. + +It turns out that the diameter +is actually 2 . + +5 centimeters. + +So, good job, experiment well +done, plus we were not exposed + +to radioactivity, which +is a bonus. + +So, this is exactly how +Rutherford did discover that + +these particles were present +and made this new model for + +the atom that we now know has +both a nucleus, and we know + +the size, and also +has electrons. + +So, to finish up today, we won't +get through all of it. + +But the next thing we can +actually talk about is now + +that we know we have an atom +that has a nucleus, let's say + +somewhere in the center, and +it has electrons around it, + +thinking on our most simple +example, which is hydrogen, we + +have a nucleus and an electron +that have to hang together in + +the atom in some way, and we +need to think about well how + +can we describe how atoms +behave, and specifically, how + +do we describe how any single +atom stays together where the + +two are associated, but at +the same time they don't + +immediately collapse +into themselves. + +So, what we can do is try +using the classical + +description of the atom and +see where this takes us. + +So, if we think about the force +that occurs between a + +positively and a negatively +charged particle, what we have + +is essentially a Coulomb force, +so we can describe this + +as a force of attraction. + +We can use the Coulomb force law +to explain this where we + +can describe the force +as a function of r. + +So, let's think about what +we're saying here. + +We're describing the force +that's holding these two + +particles together, and it's +related to the charge of each + +of the particles, where e is +the absolute value of an + +electron's charge. + +So, an electron has a charge of +negative e, we've written + +here, and the nucleus has +a charge of positive e. + +And then we have r, which is +simply the distance between + +the two charges. + +And what we see is that the +force is inversely related to + +the distance between +the two charges. + +And we can simplify this +expression as saying negative + +e squared over 4 pi, epsilon +nought r squared. + +Epsilon nought is a constant, +it's something you might see + +in physics as well. + +Essentially for our purposes +here, you can just think of it + +as a conversion factor. + +What we need to do is get rid +of the Coulomb tag that we + +have -- that's how we measure +our electron charges -- + +charge, and so we use this +epsilon nought quite often, + +this permativity constant +of a vacuum to make that + +conversion. + +And I'll just point out here +also, this is a conversion + +factor you'll use quite +frequently -- many of you, + +quite on accident, will memorize +it as you use it over + +and over again. + +But I do want to point out +that you don't have to + +memorize it for any exams in +this class, we will give you a + +sheet that has all the needed +constants that you're going to + +use on there, so save up that +brain space for other + +information. ah + +So, we can use Coulomb's force +law, and we can think about + +these different scenarios. + +So, when you come in on Monday, +we're going to start + +off, you can think for the +weekend -- you probably only + +need to think for a second about +what happens when r goes + +to infinity, but that's where +we'll start on Monday. + +And let me just suggest to all +of you also, that you get + +those problem sets started +this weekend. + +You should absolutely finish, +at least through part a this + +weekend, and save part +b for next week. + +So, have a great weekend. \ No newline at end of file diff --git a/l-tzjenXrvI.txt b/l-tzjenXrvI.txt new file mode 100644 index 0000000000000000000000000000000000000000..c86966ffd829c4c84d955f286bf61d377dea141f --- /dev/null +++ b/l-tzjenXrvI.txt @@ -0,0 +1,2399 @@ +PATRICK WINSTON: Many of you, +maybe most of you, will never + +have to work another search +problem by hand in your + +natural life. + +Others will want to +take another run + +at it on the final. + +I've been much criticized +for this way of doing + +grading in the class. + +But the way I look at it is that +the relationship between + +students and instructors ought +to be less adversarial than it + +used to be in the good old days +when I was a student. + +I especially remember an +examination we took-- + +all of us took-- on Rayleigh +scattering. + +That was 803, I think. + +And back in the old days, we +had to take four physics + +courses, not just two. + +And we had to take four math +courses, not just two. + +Back in the days when-- + +well, I was going to +say men were men. + +But most of us were +men in those days. + +I think we only had 20 +women in our class. + +Anyway, we had a quiz on +Rayleigh scattering. + +And I thought, well, this +is pretty hard. + +And then I got my quiz back. + +26. + +I thought, well, I've +been found out. + +I'm going to flunk out. + +My father will make me +go to law school. + +I'll never attract +anyone to marry. + +Horrible things will happen. + +Then the instructor announced +the class average was 18. + +I was two standard deviations +above that. + +They gave us the same exam +two weeks later, + +and accounts vary. + +Some people say that the class +average went down. + +Anyway, today we're going +to study some stuff. + +We're going to study some +stuff that will make it + +possible for you to understand +how you can do that + +computation in just a couple +of seconds, even with the + +delays introduced by +the redrawing. + +Now this particular program-- + +I'm not real sure and I don't +have a proof, but I think it + +will take more than the lifetime +of the universe to + +find a legitimate coloring of +the continental United States. + +But by the end of the next +class, you'll see how to do + +that lickety-split in just +couple of seconds, even with + +the re-display delays. + +Now we could, of course, +do this in two ways. + +One way is I could start off +by saying, let C be a + +constraint satisfaction +problem and just + +give you the result. + +And anybody can do that. + +That's great. + +And you needed to learn +some stuff that way. + +But there are some things that +you needed to learn, I think, + +a different way. + +And that different way involves +my telling you the + +story of how it all +came to be. + +This is a new field, pretty +much, and therefore I know + +most of the people in it. + +And I know all of the people +who did the work that I'm + +going to tell you about today. + +I'm going to tell you a little +bit about the struggle for + +coming up with the ideas that +led to one of the most + +powerful methods you'll learn +about in the subject. + +It all has to do, originally, +with an attempt to make a + +computer capable of seeing. + +And everybody said to +themselves, well, let's start + +with seeing simple things, +like children's blocks. + +And so Adolfo Guzman, a graduate +student of Marvin + +Minsky's, was charged with the +summer project, which led to + +his Ph.D. thesis, of writing a +program that could look at a + +line drawing and determine +how many objects + +are in the line drawing. + +So for example, there behind my +outline is a line drawing. + +And you believe instantly that +there are two objects there, + +even though in some deep +sense, it's ambiguous. + +There are all sorts of ways +that you could, through + +trickery, arrange something with +even seven objects that + +look that way. + +But most people would say +there are two objects. + +So Guzman set about the +problem of figuring + +out how to do that. + +And then his work was followed +by Dave Huffman. + +And his work was followed +up by Dave Waltz. + +And his work was followed up by +Jane [? Froyter ?], who's + +not listed there quite yet. + +And I want to tell you a little +bit of story how that + +all happened. + +So Guzman took a lot +of pictures. + +He went to Boston Baby, the +precursor to Toys R Us, + +purchased a large block set on +a government contract, and + +went about the business of +taking a lot of pictures of + +them so he'd get a feel +for the domain. + +And eventually he decided that +he could build a program that + +could determine that there are +two objects here by using the + +lines as a quanta of evidence +about which faces belong + +together in an object. + +So he said, after studying these +for a long time, that + +these drawings tend to have a +lot of arrow-type junctions + +and a lot of fork-type +junctions. + +And when you see an arrow, it's +a little bit of evidence + +that the objects on either +side of the shaft are the + +same-- the face on either side +of the shaft belong to the + +same object. + +And over here, the fork-type +junction suggests that + +pairwise, three pairs +of faces seem to + +belong to the same object. + +So with that idea, he could come +back to a drawing like + +this and start decorating it +with these so-called links, + +these quanta of evidence +that faces + +belong to the same object. + +And if I've done it right, +you get something + +that looks like so. + +It's a little hard to +see what's going on + +on the drawing itself. + +So let me number these. + +Now I have an +easier-to-deal-with picture. + +There are two links between +1 and 2 and 1 and 3. + +One link between 2 and 3. + +One between 2 and 4. + +Two here. + +Two here. + +And one each from +all of these. + +So Guzman produces this evidence +for how the problem + +ought to be solved and then he +begins to think about various + +ways of using the evidence. + +So he could, and did, decide +that one link is enough to + +presume that the faces belong +to the same object. + +And you can see that that's +a little bit too liberal. + +Because that says +that the whole + +thing is just one object. + +So Guzman rejected the one-link +theory and went to + +the two-link theory. + +And the two-link theory says, +oh, well, let's see. + +If we insist that two links +should be there before we are + +willing to decide that it's the +same object, then these + +three faces are pulled together +into one object. + +These three are pulled together +into one object. + +But alas, 7 doesn't share two +links with anything, so it's + +left dangling out there. + +So plainly, the two-link theory +is too conservative. + +So that as you would soon +discover in any [INAUDIBLE] + +project, would lead you to a +third theory, which is two + +lengths repeated. + +So now that we've formed these +super regions, we can come + +back and say we'll merge super +regions if they're connected + +together by two or more links. + +So nothing new happens +up here. + +But this super region +is joined at 7 + +by two or more links. + +So it pulls everything +together like so. + +So that worked fine. + +Well, it didn't work fine. + +There were lots of examples +of situations + +where it didn't work-- + +in situations that were +considered nonsensical by us + +humans because it seemed silly, +the kind of conclusions + +that it reached. + +So when Guzman presented this +work in his Ph.D. thesis + +defense, it's said-- + +and who knows if it's true-- +but it's said that Marvin + +Minsky thought it was +great work and we + +should make him a professor. + +It happens that Dave Huffman was +also on the committee and + +said that it was ad hoc and the +thesis should be rejected. + +So we had two polar opposites +of impressions there. + +Dave Huffman, by the way-- + +you've heard that name +before, I imagine. + +It's the guy who invented +Huffman coating as a term + +paper in a information theory +course taught by Bob Fano. + +He got an A, they say. + +So Huffman didn't like it. + +He thought it was a little +bit too ad hoc. + +It was too heuristic. + +It didn't take advantage +of anything we + +might know about physics. + +And so people began to say, +well, why does it work? + +And when does it not work? + +And that's just about the best +question you can answer in a + +situation like this. + +And by playing with some more +of Guzman's pictures and + +reflecting on them, it turned +out that it worked because the + +world is full of three-face +junctions. + +Or let me say three-face +vertexes because they're out + +there in the world. + +We'll reserve the word junction +for something else. + +And three-face vertexes +generally project into either + +an arrow or a fork. + +So Guzman's whole program worked +on the weak backward + +conclusion that if you see one +of those, it probably came + +from one of these. + +So this is in the drawing. + +That's in the world. + +So by a process that's neither +deduction or induction, but + +rather abduction, you see +one of those guys. + +And you say, well, they often +come from three-face vertexes + +in the world, so if you see one, +it probably came from a + +three-face vertex +in the world. + +That's abduction. + +So once Huffman saw all that, +being a mathematician, he + +began to think about how one +might develop a different and + +better theory. + +But we have to recognize that +all this work started off with + +the efforts of Guzman, who +was an experimentalist. + +And Huffman was a +mathematician. + +So naturally, they approached +the problem differently. + +So Huffman says, I'm not going +to concern myself too much + +with the actual problem that +Guzman was trying to solve. + +Rather, I'm going to work in a +very simple world, which I can + +deal with mathematically. + +So he decided that he was going +to work in a world which + +had several characteristics. + +Characteristic number one was +that the world would be + +presented in general position. + +That is to say, no +screw cases. + +So if you see a cube, it's +going to look like this. + +And it's not going to +look like this. + +So that's out. + +And this is in. + +And the idea here is that that's +not general position, + +because if you perturb your +point of view a little bit, + +you'll change those T junctions + +into forks and arrows. + +So we know it had to deal +with those kinds of + +weird kinds of cases. + +So that's presumption +number one. + +Presumption number two is that +we're going to be dealing with + +a world that's trihedral. + +That means all vertexes out +there are going to be formed + +from three planes. + +So you're going to have the +intersection of three planes. + +So how many kinds of junctions +can you see if the world is + +composed that way is the +question that Huffman sent + +himself upon. + +The next assumption was that +there are going to be four + +kinds of lines. + +See, Guzman only recognized +two kinds of lines-- lines + +that have a length and lines +that don't have a link. + +And they don't have very much to +do with the physical world. + +So Huffman says, I want to get +the constraint out of the + +physical world. + +So I'm going to deal with +four kinds of lines-- + +concave, convex, and boundary. + +So each of those kinds +of lines is going to + +have its own notation. + +We'll call the convex lines +plus, the concave lines minus, + +and a boundary lines are going +to get an arrow on them, + +depending on which side +of the object-- + +which side you would see the +object if you walk along the + +direction of this +little arrow. + +STUDENT: Question. + +Which is concave and +which is convex? + +You said something and you +wrote the opposite. + +PATRICK WINSTON: Yeah, sorry. + +Thank you. + +So concave, convex, +and boundary. + +Thank you. + +So this down here, that's +a concave line. + +And that would get +a minus label. + +Oh, I don't know. + +These lines you're seeing here, +if there were stuff + +behind them instead of +me, then all those + +would be convex lines. + +Many times you see +a boundary line. + +For example, now you don't see +both sides of that line down + +here at the bottom. + +So that's a boundary line. + +And the arrow would point in +that direction, so as to keep + +the stuff of the object on the +right as you walk along a kind + +of mathematical convention. + +So three kinds of lines, +four kinds of labels. + +And there's some things +left out. + +That's because Huffman wanted +to keep his problem simple, + +something he could +manage by hand. + +What's left out? + +Cracks are left out. + +Shadows are left out. + +There's a presumption that +there's nothing of interest + +here with respect to that. + +So let's have a little +vocabulary before I go on. + +And I'll try to stick to it. + +But there's the stuff out there, +and that consists of + +vertexes and edges. + +And over here, on the +blackboard, we'll have + +junctions and lines. + +And I'll try to stick +to that vocabulary. + +All right? + +Yes, Christopher? + +STUDENT: Didn't you say there +were four types of lines? + +PATRICK WINSTON: Yeah, there +are four kinds of-- + +the question is, didn't +I say there were + +four kinds of lines? + +There are three kinds of lines, +but since we can label + +a boundary line in +either direction, + +we have four labels. + +OK? + +It depends on which side of the +object the stuff is on. + +And that will be clear, +I think, as + +soon as I do an example. + +So one, two, three +assumptions. + +A little bit of vocabulary. + +So we have the possibility of +making a complete catalog. + +This is so simple. + +We have the possibility of +making a complete catalog of + +all the ways that lines can +come together to form a + +junction with respect to +these four labels. + +Now at first you might say, oh +my god, that will take a + +couple of years. + +But maybe it won't take +a couple of years. + +And in the end, to perhaps your +surprise, you discover + +that there are only 18 ways to +arrange the labels around a + +junction in this world. + +Everything else is excluded. + +If you have something that's not +in the set we're going to + +produce now, it can't be built +with trihedral vertexes. + +So I've listed up there six L's, +five forks, four T's, and + +three arrows. + +Let's see if I can figure out +why there are those 18 and + +nothing else. + +Well, if we have three vertexes +coming together, that + +means there are eight +octants, right? + +And the stuff of the object may +fill 1, 2, 3, 4, 5, 6, 7 + +or all eight octants. + +Now of course, if you +fill all eight + +octants, there's no junction. + +So we don't consider +that case. + +If we don't fill any the +octants, there's no junction. + +There's no vertex. + +So we don't consider +that case. + +But if just one of the eight +octants is filled with stuff, + +then we can look at +it from any of the + +seven remaining octants. + +So right now, you're looking +at it from one of the seven + +remaining octants. + +And if I'm not mistaken, +you're going to see a + +fork-style junction +there, right? + +And you're going to see a +fork-style junction in which + +all of the edges are convex. + +An unfortunate selection of +names, because the linguists + +tell me that we index +all of our words + +by the first forename. + +And those have the same +first forename, so + +they're easily confused. + +So here's a fork-style +junction. + +And we know that one way that's +legitimate for the + +lines to come in is +with four pluses. + +Now that's not the only +way you can see that. + +And here's another way. + +There's an L-style +junction, right? + +And both of those are +boundary lines. + +And we want to draw the boundary +line indicators on + +there so that if we walk along +the arrows, the stuff of the + +object would be on the right. + +So I suppose, to make it easier +to me do my drawing, I + +should look at it this way. + +And then I would say, well, that +has to be a legitimate + +way of labeling a junction. + +Are there any more? + +Well, there's seven altogether, +but many of them + +are the same. + +There is one more that's a +little different, though. + +I can hold this guy +up like so. + +And if I'm holding at the right +angle for you, you see + +an arrow-style junction, +right? + +Two boundaries, and the +barb is convex. + +So in this particular +case, I've got that. + +I've got that. + +And I've got a plus there. + +And that's there happen to be +for the one octant filled with + +stuff case. + +I happen to be able to +reverse this, though. + +And here's the seven octants +filled case. + +So that tells us that it's +possible to have a vertex out + +there in a space that when +reduced to a junction on the + +board deserves three minus +labels, because all of these + +that you're seeing +now are concave. + +So another fork-style junction +looks like so. + +And since there's only one +octant to look at from, that + +completes our analysis of the +seven octants filled case. + +Now we have a couple of other +possibilities here. + +We might have five octants +filled with stuff. + +So that means there are three +octants that we can look from. + +So let's suppose that +these little chalk + +pieces are little people. + +And they're looking at this +junction down there, where + +this white object is fused +with the table. + +I'm fusing it with the table +because I want to consider it + +to be one object. + +We can view it from the three +objects indicated by those + +three little chalk pieces. + +And ask ourselves, well, in the +event that we look at it + +from those three places, +what do we see? + +And if we look at it from the +perspective of the piece of + +purple chalk-- + +I'll have to walk around +and be sure-- + +looks like an arrow +junction with two + +concaves and a convex. + +Did I get that right? + +So I'm looking at it from +this perspective. + +It's an arrow. + +This is convex and these two +are concave because I fused + +the paper box with the table. + +Looking at it from the +perspective of this blue guy-- + +let me rotate it so you can have +a better understanding of + +the blue guy-- + +it looks like a concave +line and a boundary. + +So it's an L. And this +one is a boundary. + +And that's concave. + +And by a kind of symmetry, we're +also going to get that + +one from the other side, the +third of the three octants. + +Well, we're off and running. + +But we still have an +awful lot to go. + +And we could manage to deal with +it by thinking about this + +object once again. + +But instead of this situation +out here, to turn it around + +and look at this vertex. + +Think about the junctions +that it can produce. + +I think I'll do that for you. + +Because you really have to play +with this and move it + +around a little bit to see how +things are going to look. + +So let me think about how that's +going to work out. + +I know that one of the +possibilities is going + +to look like so. + +I might as well not hide +that from you. + +It's going to be what happens +when there's a little man + +looking up at the junction. + +And this one's going +to be minus. + +And now we've got two more +that are just like that. + +Look like so. + +And you say, oops. + +You say, aren't those +just a rotational + +variance of each other? + +And the answer is sure. + +I write them all down, because +if you get a fork-style + +junction in space, there are +three different ways it could + +be labeled. + +Depending on which of +the lines you put + +the minus label on. + +So that takes care of that. + +And then there's one more of +these fork-style junctions. + +And that's plus, plus, minus +that derives from this case. + +And there appear to +be three more of + +these L-style junctions. + +And they look like, let's +see, plus, then plus. + +I'm having to think this +through as I go. + +And then-- + +and that's it. + +Well, what about the T's? + +Well, in this world, the only +way you can get a T is if some + +object is obscuring +another object. + +And if an object is obscuring +a line, it can + +be any line at all. + +So that's why the four remaining +ones are easy beyond + +description to label. + +And of course, the cross +pieces of the T are all + +boundary lines, with the +obscuring object on the right. + +Now let's see. + +We've taken care now of the one, +three, five, and seven + +octants filled cases. + +What about two, four, and six? + +Well, it turns out you can have +vertexes that are made + +that way too. + +But they will have more +than three faces. + +They'll have six faces. + +They'll be like what happens +when an object comes together + +at a point, like so. + +Like that. + +You can play with it a little +bit and see that if you have + +two, four, or six objects filled +with stuff, there are + +more than three faces. + +So we're going to +ignore those. + +So our constraint is going to +be a little more severe than + +would be suggested by the +terminology Huffman uses. + +They're going to be trihedral +all right, but they're also + +going to be three faces. + +So we went to a lot +of work there. + +But what have we discovered? + +We've discovered that in this +world, this is a complete, + +100% percent, nothing excluded, +nothing else can be + +there, catalog of all possible +ways the junctions can have + +line labels arranged +around them. + +There's nothing else +in this world. + +So that's a very powerful +constraint. + +So now let's see what +we can do with it. + +This example is usually more fun +when the Red Sox are doing + +better, but they're not. + +Yet we'll use it any way. + +We're going to start +with an object that + +looks like home plate. + +And I'll ask you the question. + +Can you build one of those? + +I don't know. + +Let's give it a shot. + +We're going to assume that +this object is hanging, + +floating in space. + +So therefore, all of these lines +around the boundary are + +boundary lines, like so. + +Now that gets us off to a good-- +it's just hanging in + +space, Christopher, all right? + +You look confused. + +It's just hanging in space so +that all the lines around the + +edges are places where you see +only one side has stuff on it. + +So that enables us to just +quickly run around the + +periphery and put arrow labels +on all those outside lines. + +Now we have a lot +of arrow-style + +junctions on the boundary. + +That's commonly the case. + +So we can run over to our +catalog of all possible + +labels, and we see that if we +have an arrow with boundaries + +on its barbs, there's +only one of those. + +So I know instantly that there +must be a plus on the shaft. + +So we can come back here and +take all these arrows here. + +And label them with plus +lines on their shafts. + +Now a line can't change its +nature along its length. + +So if it's a plus line on one +end, it's going to be a plus + +line on the other end. + +All right? + +So what else can we do? + +Here deep inside is a +fork-style junction. + +It's got convex markers on +both of those two lines. + +So we go over to our catalog and +say, what can we say about + +it, given that there are pluses +on two of its lines? + +Whoop, that means that +the third one has to + +be a plus as well. + +And now we're done. + +We've labeled everything. + +Except-- + +look at this. + +What about that guy? + +There's an L-style junction +with pluses on + +both of its two lines. + +Is there one of those +in my catalog? + +No. + +Therefore, I haven't passed +a necessary condition for + +constructability in the +world that I've made. + +You can't make it. + +You can't construct it. + +So Huffman's ideas give us a +way of testing something to + +see if it's not possible for +it to be in this world. + +If it passes the test, does +that mean it's possible? + +No. + +It's a necessary but not +sufficient condition. + +On this one-- + +blue-collar occupation-- + +on this one, maybe it +will help if we + +put in another line. + +For example, we could +put a line like so. + +You feel better about it now? + +I don't know. + +Let's see. + +This has to be a plus for the +same argument we used on + +several other arrows before. + +That gives us an arrow-style +junction here with a plus on + +everything. + +Is there such a junction +label? + +No. + +We lose. + +It doesn't help. + +You think you can make +it, but you can't. + +STUDENT: You could actually +construct it as + +a 3-D object, though. + +PATRICK WINSTON: He +thinks you can + +construct it as a 3-D object. + +Let me show you the next +example, Christopher. + +Consider this example. + +Can you make that? + +Your intuition is yes. + +So let's label it. + +Oh, I've already lost. + +We just boost that up a +little bit to make the + +situation more clear. + +So already, I've got myself in +a situation where I can't + +label that. + +But you feel like +you can make it. + +So what's wrong? + +What's wrong is-- + +what, Elliott? + +STUDENT: You have +an obscured-- + +or, we're presuming that we have +an obscured [INAUDIBLE] + +alley from the upper-left corner +to the [INAUDIBLE]. + +PATRICK WINSTON: Putting a +little interpretation on what + +Elliott has said. + +If you look at this situation +back here, you get a + +four-faced junction there. + +So you can make it. + +But not with three faces. + +So some of these look like +you could make it. + +But they can't be labeled +because you need more than + +four faces at a junction. + +And we can carry that +idea back here. + +You can make this OK. + +But this junction, you've got +two in the back and two here. + +So it has four faces. + +Same idea. + +So that's Guzman's +contribution. + +That's Huffman's contribution. + +Huffman was a mathematician. + +But we wanted to build robots +back in those days. + +And neither one of these guys +solved the problem of dealing + +with natural objects with +shadows, with cracks, with + +more than trihedral vertexes +in space, and + +what to do about that? + +Well, that was a problem that +another graduate student, + +David Waltz, set +about to solve. + +So Waltz decided that he would +not be content unless he added + +cracks, shadows, non-trihedral +vertexes. + +Uh-- + +yeah, non-trihedral vertexes. + +And light. + +These considerations led +Waltz to go from + +four labels to 50-plus. + +Because he had to pack a lot +of information into each of + +the labels he put on a line. + +What kind of light +was on the right? + +What kind of light +was on the left? + +Maybe it's a crack. + +Maybe it's a crack that-- + +all sorts of considerations. + +Here we had 18 ways that +lines can come + +together around junctions. + +That went to thousands of +junctions in Waltz's world. + +So here's Guzman. + +He writes a program that +sort of works. + +Down below, we have Huffman. + +Huffman, who has a theory but +solves the wrong problem. + +So here comes Waltz, and he's +trying to solve the right + +problem with a satisfying +theory that has a + +generalizable principle. + +So when we get all through +this, we'll talk about + +criteria for success. + +And we'll conclude that to +have a really successful + +thing, you need a problem, +to start with. + +You need a method that works. + +And you have to show +that it works + +because of some principal. + +So Guzman had the problem and +something that worked. + +Huffman had a method which +worked on the wrong problem. + +And it's left to Waltz to +bring it all together. + +So Waltz does all this work. + +And now he has, instead at 18 +labels, he has thousands. + +Instead of four-line labels, +he has more than 50. + +So naturally, it becomes +difficult to + +work these by hand. + +We were able to work those +Huffman examples by hand. + +We started with labeling +everything on the boundary and + +worked our way in. + +There's no particular +method there. + +It was just easy to work +out the puzzle. + +But poor Waltz, he didn't +have that luxury. + +So he might have, in a typical +scene, he might have tens or + +even hundreds of junctions to +label and no easy way of + +dealing with it. + +So naturally writes himself a +depth-first search program. + +So here is vertex, or rather +junction number 1. + +There are many choices for which +label can be used on it. + +And for each of those choices, +whatever he's decided junction + +number 2 is has its own suite +of possibilities. + +And so it becomes a +simple depth-first + +search problem, right? + +So in actuality, as +soon as Waltz-- + +he was my office mate +at the time. + +I can tell you this +for a fact. + +As soon as he wrote this +program, he kept looking over + +at the computer-- + +they were big in those days. + +They all had lights. + +So you looked over at the +computer to see if the lights + +were still blinking. + +Because he'd start this +depth-first search program up + +and nothing would happen. + +He thought the computer +had crashed. + +Nothing happened. + +Why did nothing happen? + +Because the search base is +exponential and much too big + +for an ordinary computer, +or maybe + +even an ordinary universe. + +So Waltz has to do +something else. + +He has to come up with a new +method for using all these + +labels that he's-- + +after about a year and a half's +worth of hard work, + +with lots of paper on his +desk in little blocks. + +After year and a half of hard +work getting all these + +junction labels figured out, he +then has to come up with a + +method for figuring out +how to use them. + +And so we don't know whether +to think his biggest + +contribution was that label +set or his method. + +And probably both deserve +about equal billing. + +Oh, I don't know how to explain +what Waltz did. + +Well, one way is to +do an example. + +And I think I will hazard +an example. + +Let's see. + +Let me find some space. + +I think I'm reduced to +going over here. + +But that will be convenient, +since the + +line labels are here. + +Here's my example. + +And you say, how can I give you +just part of a picture? + +Well, you can assume +I'm looking at + +this through a window. + +So the edge of the window form +boundary lines, and they exert + +no constraint whatsoever +on what's behind them. + +So this is a legitimate +drawing to + +have to think about. + +By the way, is this ambiguous? + +Or do you get a firm sense +that there's a unique + +interpretation of +all those lines? + +I think there's a unique +interpretation + +of all those lines. + +What I'm going to do is I'm +actually going to solve this + +problem using Huffman's labels +but Waltz's method. + +Because I can't simulate on the +blackboard something with + +50 line types and thousands +of line junctions. + +So I'm going to use +Huffman's set to + +demonstrate Waltz's algorithm. + +So Waltz's algorithm involves +starting out by plopping on + +some junction all of the +possible labels that the + +answer has to be drawn from. + +So let me number these in the +order that we're going to + +visit them. + +Like so. + +And so far, I've just put down +the three fork options that + +are resident on that +first junction. + +And I have to take note of +exactly what they do with the + +lines that come out +of the junction. + +So let's see. + +I'll just copy them down. + +One possibility is this one. + +Another possibility +is this one. + +And another possibility +is plus, plus, minus. + +Oops, I've got plus, plus. + +No, that's right. + +So that right so far? + +All I've done is copy +the junction + +labelings from my library. + +And at this point, Waltz's +algorithm says there's nothing + +else to do but go on to +junction number two. + +And unfortunately, sadly, there +are lots of labelings + +that have to be considered +on junction number 2. + +Six of them. + +1, 2, 3, 4, 5, 6. + +So one of them looks +like that. + +Another one looks like that. + +One of them is plus +here, arrow in. + +Another one is plus +here, arrow out. + +Another one is minus +here, arrow down. + +And minus here, arrow up. + +I think I've copied +those all right. + +But now, having copied those +down, Waltz's algorithm looks + +around at the neighboring +junctions and says, are any of + +the things that I just placed on +junction two disallowed by + +what I've already placed on +a neighboring junction? + +So it looks over here +in step number two. + +And it sees that these three +arrows require the line that + +joins junctions 1 and 2 to +be either minus or plus. + +So of the six possibilities, I +can only keep the ones that + +are likewise content to put +a plus on that line + +that joins the two. + +So that means that the influence +flowing from + +junction 1 eliminates that +one, eliminates that one, + +eliminates that one, and +eliminates that one. + +So half of them are gone. + +All the ones that try to put a +boundary line on that line + +between 1 and 2 are +disallowed. + +All right? + +Now likewise, we could say, +well, of the remaining ones, + +do they restrict what I +can do at junction 1? + +So let's see. + +Here's a minus. + +And here's a plus. + +So all these possibilities over +here are still alive. + +So now, continuing on, we have +to see what we can do at + +junction 3. + +These are arrow labels again. + +So we have to copy exactly +the same labels + +set as we had before. + +And now we look down at junction +2 and say, well, what + +does that tell me about the +three that I've just placed? + +If we look up from junction +2 to see what kind of + +constraints it puts on here, +we have this one alive and + +this one alive. + +I guess we've eliminated +four of the six. + +So we have these two alive. + +And they both but +boundary lines-- + +I think I must have had this +boundary line wrong, right? + +No, that's right. + +Oh yes, I see. + +Plus. + +This one goes-- + +hang on a second. + +You let me do something wrong. + +So plus is out. + +And that must be +one that goes-- + +this minus goes up. + +Oh, yes. + +I'm too hasty and uncertain +about what I was doing. + +So let's see. + +This guy has a boundary +going down. + +And this guy has a boundary +going up. + +All of the others have +been eliminated. + +So that means that something +that tries to put a concave + +line there is gone. + +And something that tries to put +a plus line there is gone. + +So the influence flowing up in +this direction in the third + +step eliminates that guy and +eliminates that guy, leaving + +only this guy. + +But now, the thing I was worried +about is you have to + +also at this point go down to +2 and see if there's any + +further constraint on what can +survive down there, based on + +what has happened over +here at junction 3. + +Now let's see. + +This one goes up, which is +compatible with a survivor. + +But this one goes down, +which is not + +compatible with a survivor. + +So when I bring this down in +step three, this guy is + +eliminated. + +So now I'm down to just one +interpretation for what can be + +going on at vertex number 2. + +And one interpretation +for vertex number 3. + +Now let's see. + +This can propagate. + +So now that I've made a change +on vertex number 2, I have to + +also see if that causes a change +at vertex number 1. + +So it's propagating through. + +And now I can see that the only +possibility here is a + +minus, the label that's coming +down from our survivor. + +So that eliminates these two. + +Whew! + +It's hard to do this by hand, +but I've got three of the four + +things labeled. + +And even with just three of the +four labeled, I'm down to + +a single interpretation for all +of the junctions and the + +lines between them. + +So there's one left. + +We have to deal with +that fork vertex. + +We better deal with it, because +for all we know, this + +is not a legal drawing +in this world. + +We have five fork vertexes +to place. + +But you know what? + +I don't have to draw much here, +because I know this is + +forced to be a plus now. + +And this is forced +to be a plus now. + +And there's only one fork +vertex with any + +pluses on it at all. + +So now I can come through and +say, well, the only possible + +survivor is this one. + +These are gone. + +And now I have an +interpretation + +for all of the junctions. + +And I see that the winners +are this one. + +And this one. + +And this one. + +And this one. + +So I've got a unique +interpretation. + +This line is convex. + +This one is concave. + +This is a boundary. + +That's a boundary. + +And this line is convex, +and that's convex. + +Now that's a lot of work. + +So I better check and make +sure I got it right. + +You'd like to see this +demonstrated to make sure I + +haven't made a mistake. + +I'm sure of that. + +Let's see. + +That it? + +So each of the places where a +line is obscured has four + +possibilities, labeled E. The +arrow junctions are labeled A. + +The forks-- there are five of +them-- at the fork junction 5. + +So let's just step through here +and see what happens. + +Boom. + +I've got it. + +I did do it right. + +So let's try some more. + +What do you think will +happen with this one? + +Unique solution? + +It stopped. + +Bug in my program? + +Unthinkable. + +What's happened? + +It is genuinely ambiguous. + +It can be something hanging +down from the ceiling. + +Or it could be something that +we can think of as a step + +going up from left to right. + +Let's look at something +more complicated. + +You think it'll work? + +Not enough constraint for us +to figure that one out. + +It's equally ambiguous, but a +little bit larger example. + +What about this one? + +Yeah, but the stuff is creeping +up from the lower + +left up to the upper right. + +Yeah, bingo. + +It worked. + +It's unambiguous. + +It's variation on the same +theme we had before. + +But let me, just for fun, take +these two lines out. + +What do you think +will happen now? + +Seems to be doing just fine +until it hits the upper + +right-hand corner and discovers + +it can't label stuff. + +So it propagates back down. + +And what looked OK in +the lower left is + +no good after all. + +So these results are kind of +consistent with what we humans + +do when we look at these +kinds of things. + +So it's very likely that we, +in our heads, do have some + +constraint propagation +apparatus + +that we use in vision. + +But putting that aside, we can +think about other kinds of + +intelligence different from +human, that might use this + +kind of mechanism to solve +problems that involve a lot of + +constraint in finding +a solution. + +So here, we saw the constraint +propagation activity at work + +on line drawing analysis. + +But next time, what we're going +do is we're going to see + +at work in map coloring. + +And who cares about +map coloring? + +People who do scheduling, +because that turns out to be + +the same problem. \ No newline at end of file diff --git a/lo-5afXPHx0.txt b/lo-5afXPHx0.txt new file mode 100644 index 0000000000000000000000000000000000000000..5534c7dff75b6ea3f48f1cdd8614ad1d01dad9df --- /dev/null +++ b/lo-5afXPHx0.txt @@ -0,0 +1,3723 @@ +align:start position:0% + +so now that we've + + align:start position:0% +so now that we've + + + align:start position:0% +so now that we've +discussed prevalence and risk scenarios + + align:start position:0% +discussed prevalence and risk scenarios + + + align:start position:0% +discussed prevalence and risk scenarios +we come to a very important topic which + + align:start position:0% +we come to a very important topic which + + + align:start position:0% +we come to a very important topic which +is when should you impose the guideline + + align:start position:0% +is when should you impose the guideline + + + align:start position:0% +is when should you impose the guideline +obviously when the the epidemic + + align:start position:0% +obviously when the the epidemic + + + align:start position:0% +obviously when the the epidemic +is raging at a very high rate is feels + + align:start position:0% +is raging at a very high rate is feels + + + align:start position:0% +is raging at a very high rate is feels +out of control + + align:start position:0% +out of control + + + align:start position:0% +out of control +it's spreading we want to impose the + + align:start position:0% +it's spreading we want to impose the + + + align:start position:0% +it's spreading we want to impose the +guideline that we've discussed which + + align:start position:0% +guideline that we've discussed which + + + align:start position:0% +guideline that we've discussed which +limits the indoor reproductive number + + align:start position:0% +limits the indoor reproductive number + + + align:start position:0% +limits the indoor reproductive number +for each space within some tolerance and + + align:start position:0% +for each space within some tolerance and + + + align:start position:0% +for each space within some tolerance and +that would for example give us some + + align:start position:0% +that would for example give us some + + + align:start position:0% +that would for example give us some +number n1 + + align:start position:0% +number n1 + + + align:start position:0% +number n1 +from the safety guideline r in less than + + align:start position:0% +from the safety guideline r in less than + + + align:start position:0% +from the safety guideline r in less than +epsilon + + align:start position:0% +epsilon + + + align:start position:0% +epsilon +which is going to be smaller than the + + align:start position:0% +which is going to be smaller than the + + + align:start position:0% +which is going to be smaller than the +normal occupancy of that room for a + + align:start position:0% +normal occupancy of that room for a + + + align:start position:0% +normal occupancy of that room for a +given time and all the other factors + + align:start position:0% +given time and all the other factors + + + align:start position:0% +given time and all the other factors +that we've been discussing + + align:start position:0% +that we've been discussing + + + align:start position:0% +that we've been discussing +but what happens as the prevalence of + + align:start position:0% +but what happens as the prevalence of + + + align:start position:0% +but what happens as the prevalence of +infection goes down generically there + + align:start position:0% +infection goes down generically there + + + align:start position:0% +infection goes down generically there +must be some sort of curve like this + + align:start position:0% +must be some sort of curve like this + + + align:start position:0% +must be some sort of curve like this +and we'd like to understand what is the + + align:start position:0% +and we'd like to understand what is the + + + align:start position:0% +and we'd like to understand what is the +simplest reasonable model we can come up + + align:start position:0% +simplest reasonable model we can come up + + + align:start position:0% +simplest reasonable model we can come up +with + + align:start position:0% +with + + + align:start position:0% +with +that can tell us how to relax the + + align:start position:0% +that can tell us how to relax the + + + align:start position:0% +that can tell us how to relax the +approximation so for example let's think + + align:start position:0% +approximation so for example let's think + + + align:start position:0% +approximation so for example let's think +of a school or a business + + align:start position:0% +of a school or a business + + + align:start position:0% +of a school or a business +where we typically have this a lot of + + align:start position:0% +where we typically have this a lot of + + + align:start position:0% +where we typically have this a lot of +the same people there every day + + align:start position:0% +the same people there every day + + + align:start position:0% +the same people there every day +but some others are coming and going or + + align:start position:0% +but some others are coming and going or + + + align:start position:0% +but some others are coming and going or +maybe going home and getting infected + + align:start position:0% +maybe going home and getting infected + + + align:start position:0% +maybe going home and getting infected +and coming in so the rate of infection + + align:start position:0% +and coming in so the rate of infection + + + align:start position:0% +and coming in so the rate of infection +is is low so we expect typically the + + align:start position:0% +is is low so we expect typically the + + + align:start position:0% +is is low so we expect typically the +number of infected people is zero or + + align:start position:0% +number of infected people is zero or + + + align:start position:0% +number of infected people is zero or +occasionally one + + align:start position:0% +occasionally one + + + align:start position:0% +occasionally one +and as the prevalence goes down then you + + align:start position:0% +and as the prevalence goes down then you + + + align:start position:0% +and as the prevalence goes down then you +know we + + align:start position:0% +know we + + + align:start position:0% +know we +start to see uh you know that the + + align:start position:0% +start to see uh you know that the + + + align:start position:0% +start to see uh you know that the +situation is getting safer and safer + + align:start position:0% +situation is getting safer and safer + + + align:start position:0% +situation is getting safer and safer +so the certain point p1 where we start + + align:start position:0% +so the certain point p1 where we start + + + align:start position:0% +so the certain point p1 where we start +to say you know what we can actually + + align:start position:0% +to say you know what we can actually + + + align:start position:0% +to say you know what we can actually +increase the occupancy of the space with + + align:start position:0% +increase the occupancy of the space with + + + align:start position:0% +increase the occupancy of the space with +everything else held fixed + + align:start position:0% +everything else held fixed + + + align:start position:0% +everything else held fixed +while still wearing masks and then we + + align:start position:0% +while still wearing masks and then we + + + align:start position:0% +while still wearing masks and then we +hit the normal occupancy and you might + + align:start position:0% +hit the normal occupancy and you might + + + align:start position:0% +hit the normal occupancy and you might +call that kind of the new normal where + + align:start position:0% +call that kind of the new normal where + + + align:start position:0% +call that kind of the new normal where +we're going about our business the room + + align:start position:0% +we're going about our business the room + + + align:start position:0% +we're going about our business the room +is filled with the typical number of + + align:start position:0% +is filled with the typical number of + + + align:start position:0% +is filled with the typical number of +people let's say the classroom is back + + align:start position:0% +people let's say the classroom is back + + + align:start position:0% +people let's say the classroom is back +to its normal size we don't have any + + align:start position:0% +to its normal size we don't have any + + + align:start position:0% +to its normal size we don't have any +remote teaching going on + + align:start position:0% +remote teaching going on + + + align:start position:0% +remote teaching going on +but we're wearing masks or taking other + + align:start position:0% +but we're wearing masks or taking other + + + align:start position:0% +but we're wearing masks or taking other +factor factors into accounts such as + + align:start position:0% +factor factors into accounts such as + + + align:start position:0% +factor factors into accounts such as +higher ventilation rates let's say + + align:start position:0% +higher ventilation rates let's say + + + align:start position:0% +higher ventilation rates let's say +open windows but then we continue + + align:start position:0% +open windows but then we continue + + + align:start position:0% +open windows but then we continue +lowering the prevalence there's a + + align:start position:0% +lowering the prevalence there's a + + + align:start position:0% +lowering the prevalence there's a +certain point where we get rid of those + + align:start position:0% +certain point where we get rid of those + + + align:start position:0% +certain point where we get rid of those +other precautions + + align:start position:0% +other precautions + + + align:start position:0% +other precautions +so extra opening of windows or more + + align:start position:0% +so extra opening of windows or more + + + align:start position:0% +so extra opening of windows or more +importantly the dominant effect is the + + align:start position:0% +importantly the dominant effect is the + + + align:start position:0% +importantly the dominant effect is the +removal of the mass because we know + + align:start position:0% +removal of the mass because we know + + + align:start position:0% +removal of the mass because we know +that's a significant factor + + align:start position:0% +that's a significant factor + + + align:start position:0% +that's a significant factor +and then you might call that back to the + + align:start position:0% +and then you might call that back to the + + + align:start position:0% +and then you might call that back to the +real normal actually not the new normal + + align:start position:0% +real normal actually not the new normal + + + align:start position:0% +real normal actually not the new normal +where we are back to full occupancy and + + align:start position:0% +where we are back to full occupancy and + + + align:start position:0% +where we are back to full occupancy and +really not taking any extra precautions + + align:start position:0% +really not taking any extra precautions + + + align:start position:0% +really not taking any extra precautions +that's going to happen at a rather low + + align:start position:0% +that's going to happen at a rather low + + + align:start position:0% +that's going to happen at a rather low +prevalence but we hope that that time + + align:start position:0% +prevalence but we hope that that time + + + align:start position:0% +prevalence but we hope that that time +will eventually come + + align:start position:0% +will eventually come + + + align:start position:0% +will eventually come +and hopefully not so far in the future + + align:start position:0% +and hopefully not so far in the future + + + align:start position:0% +and hopefully not so far in the future +and i mentioned here a very important + + align:start position:0% +and i mentioned here a very important + + + align:start position:0% +and i mentioned here a very important +point we've not talked about yet in this + + align:start position:0% +point we've not talked about yet in this + + + align:start position:0% +point we've not talked about yet in this +class + + align:start position:0% +class + + + align:start position:0% +class +but we should keep in the back of our + + align:start position:0% +but we should keep in the back of our + + + align:start position:0% +but we should keep in the back of our +minds is when i talk about + + align:start position:0% +minds is when i talk about + + + align:start position:0% +minds is when i talk about +occupancy i'm really talking about the + + align:start position:0% +occupancy i'm really talking about the + + + align:start position:0% +occupancy i'm really talking about the +number of successful people we just saw + + align:start position:0% +number of successful people we just saw + + + align:start position:0% +number of successful people we just saw +that on the last couple boards + + align:start position:0% +that on the last couple boards + + + align:start position:0% +that on the last couple boards +but the number of susceptible people are + + align:start position:0% +but the number of susceptible people are + + + align:start position:0% +but the number of susceptible people are +really only those + + align:start position:0% +really only those + + + align:start position:0% +really only those +that are not immune to the disease + + align:start position:0% +that are not immune to the disease + + + align:start position:0% +that are not immune to the disease +for example by vaccination so + + align:start position:0% +for example by vaccination so + + + align:start position:0% +for example by vaccination so +as the vac as more and more people + + align:start position:0% +as the vac as more and more people + + + align:start position:0% +as the vac as more and more people +become vaccinated + + align:start position:0% +become vaccinated + + + align:start position:0% +become vaccinated +then this occupancy number might for + + align:start position:0% +then this occupancy number might for + + + align:start position:0% +then this occupancy number might for +example let's say as a typical + + align:start position:0% +example let's say as a typical + + + align:start position:0% +example let's say as a typical +opportunity of 25 people in a class + + align:start position:0% +opportunity of 25 people in a class + + + align:start position:0% +opportunity of 25 people in a class +as more and more people are vaccinated + + align:start position:0% +as more and more people are vaccinated + + + align:start position:0% +as more and more people are vaccinated +the number that we plug in this formula + + align:start position:0% +the number that we plug in this formula + + + align:start position:0% +the number that we plug in this formula +here might actually be lower + + align:start position:0% +here might actually be lower + + + align:start position:0% +here might actually be lower +when we adapt just make decisions + + align:start position:0% +when we adapt just make decisions + + + align:start position:0% +when we adapt just make decisions +because there are fewer and fewer + + align:start position:0% +because there are fewer and fewer + + + align:start position:0% +because there are fewer and fewer +susceptible people that are left so + + align:start position:0% +susceptible people that are left so + + + align:start position:0% +susceptible people that are left so +that's another very important factor to + + align:start position:0% +that's another very important factor to + + + align:start position:0% +that's another very important factor to +keep in mind + + align:start position:0% +keep in mind + + + align:start position:0% +keep in mind +of course also vaccination has the + + align:start position:0% +of course also vaccination has the + + + align:start position:0% +of course also vaccination has the +indirect effect of lowering the + + align:start position:0% +indirect effect of lowering the + + + align:start position:0% +indirect effect of lowering the +prevalence that is seen in the + + align:start position:0% +prevalence that is seen in the + + + align:start position:0% +prevalence that is seen in the +population as we start to stamp out the + + align:start position:0% +population as we start to stamp out the + + + align:start position:0% +population as we start to stamp out the +epidemic so we also have that effect + + align:start position:0% +epidemic so we also have that effect + + + align:start position:0% +epidemic so we also have that effect +so i won't talk about that any further + + align:start position:0% +so i won't talk about that any further + + + align:start position:0% +so i won't talk about that any further +now but come back to this calculation + + align:start position:0% +now but come back to this calculation + + + align:start position:0% +now but come back to this calculation +based on the risk scenario the second + + align:start position:0% +based on the risk scenario the second + + + align:start position:0% +based on the risk scenario the second +one that i talked about last time where + + align:start position:0% +one that i talked about last time where + + + align:start position:0% +one that i talked about last time where +we take into account + + align:start position:0% +we take into account + + + align:start position:0% +we take into account +prevalence so let's look at the three + + align:start position:0% +prevalence so let's look at the three + + + align:start position:0% +prevalence so let's look at the three +different cases here so the first one + + align:start position:0% +different cases here so the first one + + + align:start position:0% +different cases here so the first one +is where we have restricted occupancy + + align:start position:0% + + + + align:start position:0% + +this is where we've decided there's an + + align:start position:0% +this is where we've decided there's an + + + align:start position:0% +this is where we've decided there's an +n1 + + align:start position:0% +n1 + + + align:start position:0% +n1 +which is epsilon over average beta + + align:start position:0% +which is epsilon over average beta + + + align:start position:0% +which is epsilon over average beta +tau so all the physical parameters are + + align:start position:0% +tau so all the physical parameters are + + + align:start position:0% +tau so all the physical parameters are +buried in there + + align:start position:0% +buried in there + + + align:start position:0% +buried in there +and this is going to be something less + + align:start position:0% +and this is going to be something less + + + align:start position:0% +and this is going to be something less +than the normal occupancy and 0. + + align:start position:0% +than the normal occupancy and 0. + + + align:start position:0% +than the normal occupancy and 0. +now what is the tau we want to think + + align:start position:0% +now what is the tau we want to think + + + align:start position:0% +now what is the tau we want to think +about well if we have a school or + + align:start position:0% +about well if we have a school or + + + align:start position:0% +about well if we have a school or +business + + align:start position:0% +business + + + align:start position:0% +business +this would be the cumulative time that + + align:start position:0% +this would be the cumulative time that + + + align:start position:0% +this would be the cumulative time that +people spend together + + align:start position:0% +people spend together + + + align:start position:0% +people spend together +to the point where the number of days + + align:start position:0% +to the point where the number of days + + + align:start position:0% +to the point where the number of days +they spend together is let's say on the + + align:start position:0% +they spend together is let's say on the + + + align:start position:0% +they spend together is let's say on the +order of a week + + align:start position:0% +order of a week + + + align:start position:0% +order of a week +would be a reasonable number to think + + align:start position:0% +would be a reasonable number to think + + + align:start position:0% +would be a reasonable number to think +about because + + align:start position:0% +about because + + + align:start position:0% +about because +if we write tau as sort of the hours + + align:start position:0% +if we write tau as sort of the hours + + + align:start position:0% +if we write tau as sort of the hours +typical hours per day + + align:start position:0% +typical hours per day + + + align:start position:0% +typical hours per day +times some kind of maximum number of + + align:start position:0% +times some kind of maximum number of + + + align:start position:0% +times some kind of maximum number of +days + + align:start position:0% +days + + + align:start position:0% +days +this maximum number of days could be set + + align:start position:0% +this maximum number of days could be set + + + align:start position:0% +this maximum number of days could be set +by + + align:start position:0% +by + + + align:start position:0% +by +for example the testing frequency + + align:start position:0% + + + + align:start position:0% + +for example here at mit we are testing + + align:start position:0% +for example here at mit we are testing + + + align:start position:0% +for example here at mit we are testing +our entire population + + align:start position:0% +our entire population + + + align:start position:0% +our entire population +at least once a week in order for anyone + + align:start position:0% +at least once a week in order for anyone + + + align:start position:0% +at least once a week in order for anyone +including myself to be admitting to the + + align:start position:0% +including myself to be admitting to the + + + align:start position:0% +including myself to be admitting to the +to the campus + + align:start position:0% +to the campus + + + align:start position:0% +to the campus +and so we are definitely testing within + + align:start position:0% +and so we are definitely testing within + + + align:start position:0% +and so we are definitely testing within +a week and catching new infections at + + align:start position:0% +a week and catching new infections at + + + align:start position:0% +a week and catching new infections at +that rate + + align:start position:0% +that rate + + + align:start position:0% +that rate +it could also be motivated by the + + align:start position:0% +it could also be motivated by the + + + align:start position:0% +it could also be motivated by the +incubation time + + align:start position:0% +incubation time + + + align:start position:0% +incubation time +which is the time to show symptoms and + + align:start position:0% +which is the time to show symptoms and + + + align:start position:0% +which is the time to show symptoms and +most people will remove themselves and + + align:start position:0% +most people will remove themselves and + + + align:start position:0% +most people will remove themselves and +we know that's around + + align:start position:0% +we know that's around + + + align:start position:0% +we know that's around +5.5 days as a typically reported values + + align:start position:0% +5.5 days as a typically reported values + + + align:start position:0% +5.5 days as a typically reported values +again on the order of a week + + align:start position:0% +again on the order of a week + + + align:start position:0% +again on the order of a week +and there's also of course other ways + + align:start position:0% +and there's also of course other ways + + + align:start position:0% +and there's also of course other ways +that people are removed or recut or they + + align:start position:0% +that people are removed or recut or they + + + align:start position:0% +that people are removed or recut or they +recover + + align:start position:0% +recover + + + align:start position:0% +recover +so as removal and recovery which is + + align:start position:0% +so as removal and recovery which is + + + align:start position:0% +so as removal and recovery which is +another way + + align:start position:0% +another way + + + align:start position:0% +another way +that if you start to go more than let's + + align:start position:0% +that if you start to go more than let's + + + align:start position:0% +that if you start to go more than let's +say two weeks we start to think + + align:start position:0% +say two weeks we start to think + + + align:start position:0% +say two weeks we start to think +an effective person that didn't get + + align:start position:0% +an effective person that didn't get + + + align:start position:0% +an effective person that didn't get +removed enough in the hospital has + + align:start position:0% +removed enough in the hospital has + + + align:start position:0% +removed enough in the hospital has +probably recovered + + align:start position:0% +probably recovered + + + align:start position:0% +probably recovered +so if we think of a certain number of + + align:start position:0% +so if we think of a certain number of + + + align:start position:0% +so if we think of a certain number of +days and hours per day that gives us a + + align:start position:0% +days and hours per day that gives us a + + + align:start position:0% +days and hours per day that gives us a +tau + + align:start position:0% +tau + + + align:start position:0% +tau +that is going to go into this formula + + align:start position:0% +that is going to go into this formula + + + align:start position:0% +that is going to go into this formula +and actually i should also mention that + + align:start position:0% +and actually i should also mention that + + + align:start position:0% +and actually i should also mention that +for simplicity here + + align:start position:0% +for simplicity here + + + align:start position:0% +for simplicity here +you know technically this should be n + + align:start position:0% +you know technically this should be n + + + align:start position:0% +you know technically this should be n +1 minus 1 and i can either include that + + align:start position:0% +1 minus 1 and i can either include that + + + align:start position:0% +1 minus 1 and i can either include that +or not when i do this calculation but + + align:start position:0% +or not when i do this calculation but + + + align:start position:0% +or not when i do this calculation but +i'm generally thinking + + align:start position:0% +i'm generally thinking + + + align:start position:0% +i'm generally thinking +of n one which is going to be you know + + align:start position:0% +of n one which is going to be you know + + + align:start position:0% +of n one which is going to be you know +bigger than one so think of like + + align:start position:0% +bigger than one so think of like + + + align:start position:0% +bigger than one so think of like +an occupancy of ten people in a + + align:start position:0% +an occupancy of ten people in a + + + align:start position:0% +an occupancy of ten people in a +classroom or something might be a limit + + align:start position:0% +classroom or something might be a limit + + + align:start position:0% +classroom or something might be a limit +uh that we would be interested in + + align:start position:0% +uh that we would be interested in + + + align:start position:0% +uh that we would be interested in +considering but certainly we can put the + + align:start position:0% +considering but certainly we can put the + + + align:start position:0% +considering but certainly we can put the +the one in there if we want to so now + + align:start position:0% +the one in there if we want to so now + + + align:start position:0% +the one in there if we want to so now +let's ask ourselves how would we + + align:start position:0% +let's ask ourselves how would we + + + align:start position:0% +let's ask ourselves how would we +start to reopen the space once we've + + align:start position:0% +start to reopen the space once we've + + + align:start position:0% +start to reopen the space once we've +decided + + align:start position:0% +decided + + + align:start position:0% +decided +on a sort of safe occupancy uh during + + align:start position:0% +on a sort of safe occupancy uh during + + + align:start position:0% +on a sort of safe occupancy uh during +the greatest level of restrictions + + align:start position:0% +the greatest level of restrictions + + + align:start position:0% +the greatest level of restrictions +so that would then lead us into a phase + + align:start position:0% +so that would then lead us into a phase + + + align:start position:0% +so that would then lead us into a phase +of relaxing restrictions + + align:start position:0% + + + + align:start position:0% + +and this would still be with masks + + align:start position:0% + + + + align:start position:0% + +so keeping in mind that mass are an + + align:start position:0% +so keeping in mind that mass are an + + + align:start position:0% +so keeping in mind that mass are an +essential part of + + align:start position:0% +essential part of + + + align:start position:0% +essential part of +achieving a reasonable occupancy when + + align:start position:0% +achieving a reasonable occupancy when + + + align:start position:0% +achieving a reasonable occupancy when +the pandemic is high + + align:start position:0% +the pandemic is high + + + align:start position:0% +the pandemic is high +and there's a lot of prevalence and that + + align:start position:0% +and there's a lot of prevalence and that + + + align:start position:0% +and there's a lot of prevalence and that +we would only sort of start to + + align:start position:0% +we would only sort of start to + + + align:start position:0% +we would only sort of start to +relax occupancy first before we take + + align:start position:0% +relax occupancy first before we take + + + align:start position:0% +relax occupancy first before we take +away the suggestion to to wear mass + + align:start position:0% +away the suggestion to to wear mass + + + align:start position:0% +away the suggestion to to wear mass +and that would be then the last step so + + align:start position:0% +and that would be then the last step so + + + align:start position:0% +and that would be then the last step so +for relaxing restrictions + + align:start position:0% +for relaxing restrictions + + + align:start position:0% +for relaxing restrictions +we're then going to be interested in the + + align:start position:0% +we're then going to be interested in the + + + align:start position:0% +we're then going to be interested in the +indoor reproductive number + + align:start position:0% +indoor reproductive number + + + align:start position:0% +indoor reproductive number +being less than now a rescaled value + + align:start position:0% +being less than now a rescaled value + + + align:start position:0% +being less than now a rescaled value +which would be + + align:start position:0% +which would be + + + align:start position:0% +which would be +epsilon over p i q i + + align:start position:0% +epsilon over p i q i + + + align:start position:0% +epsilon over p i q i +n and the inter-reproductive number + + align:start position:0% +n and the inter-reproductive number + + + align:start position:0% +n and the inter-reproductive number +remember is n minus 1 but it's + + align:start position:0% +remember is n minus 1 but it's + + + align:start position:0% +remember is n minus 1 but it's +approximately n times + + align:start position:0% +approximately n times + + + align:start position:0% +approximately n times +beta tau so i've replaced again n + + align:start position:0% +beta tau so i've replaced again n + + + align:start position:0% +beta tau so i've replaced again n +minus 1 with n just to kind of get a + + align:start position:0% +minus 1 with n just to kind of get a + + + align:start position:0% +minus 1 with n just to kind of get a +simpler formula + + align:start position:0% +simpler formula + + + align:start position:0% +simpler formula +and so notice now here n is in both + + align:start position:0% +and so notice now here n is in both + + + align:start position:0% +and so notice now here n is in both +sides of the equations if i want to + + align:start position:0% +sides of the equations if i want to + + + align:start position:0% +sides of the equations if i want to +solve for the value + + align:start position:0% +solve for the value + + + align:start position:0% +solve for the value +n2 which is this yellow curve here i'm + + align:start position:0% +n2 which is this yellow curve here i'm + + + align:start position:0% +n2 which is this yellow curve here i'm +actually going to have to + + align:start position:0% +actually going to have to + + + align:start position:0% +actually going to have to +put the ends on one side and take a + + align:start position:0% +put the ends on one side and take a + + + align:start position:0% +put the ends on one side and take a +square root + + align:start position:0% +square root + + + align:start position:0% +square root +so i'll get my n2 then would be + + align:start position:0% +so i'll get my n2 then would be + + + align:start position:0% +so i'll get my n2 then would be +the square root of epsilon + + align:start position:0% +the square root of epsilon + + + align:start position:0% +the square root of epsilon +over beta tau times + + align:start position:0% +over beta tau times + + + align:start position:0% +over beta tau times +p p i times q i + + align:start position:0% +p p i times q i + + + align:start position:0% +p p i times q i +and i remember also another + + align:start position:0% +and i remember also another + + + align:start position:0% +and i remember also another +approximation here is that p i is + + align:start position:0% +approximation here is that p i is + + + align:start position:0% +approximation here is that p i is +definitely much less than one we're + + align:start position:0% +definitely much less than one we're + + + align:start position:0% +definitely much less than one we're +looking limit of very low prevalence + + align:start position:0% +looking limit of very low prevalence + + + align:start position:0% +looking limit of very low prevalence +and so also therefore qi is basically + + align:start position:0% +and so also therefore qi is basically + + + align:start position:0% +and so also therefore qi is basically +tending to 1 because it's 1 minus pi + + align:start position:0% +tending to 1 because it's 1 minus pi + + + align:start position:0% +tending to 1 because it's 1 minus pi +and so that factor is really not that + + align:start position:0% +and so that factor is really not that + + + align:start position:0% +and so that factor is really not that +important and notice + + align:start position:0% +important and notice + + + align:start position:0% +important and notice +also epsilon over beta tau that's n1 + + align:start position:0% +also epsilon over beta tau that's n1 + + + align:start position:0% +also epsilon over beta tau that's n1 +so n2 is approximately related to n1 + + align:start position:0% +so n2 is approximately related to n1 + + + align:start position:0% +so n2 is approximately related to n1 +by the square root of n1 divided by + + align:start position:0% +by the square root of n1 divided by + + + align:start position:0% +by the square root of n1 divided by +pi + + align:start position:0% + + + + align:start position:0% + +so so that's this that's this number + + align:start position:0% +so so that's this that's this number + + + align:start position:0% +so so that's this that's this number +here + + align:start position:0% +here + + + align:start position:0% +here +so as a function of prevalence this + + align:start position:0% +so as a function of prevalence this + + + align:start position:0% +so as a function of prevalence this +yellow curve is one over square root + + align:start position:0% +yellow curve is one over square root + + + align:start position:0% +yellow curve is one over square root +of prevalence and + + align:start position:0% +of prevalence and + + + align:start position:0% +of prevalence and +one nice thing about writing it this way + + align:start position:0% +one nice thing about writing it this way + + + align:start position:0% +one nice thing about writing it this way +is that i can decide on a reopening + + align:start position:0% +is that i can decide on a reopening + + + align:start position:0% +is that i can decide on a reopening +protocol + + align:start position:0% +protocol + + + align:start position:0% +protocol +without actually redoing my calculation + + align:start position:0% +without actually redoing my calculation + + + align:start position:0% +without actually redoing my calculation +with all those complicated variables + + align:start position:0% +with all those complicated variables + + + align:start position:0% +with all those complicated variables +including the restons epsilon and all + + align:start position:0% +including the restons epsilon and all + + + align:start position:0% +including the restons epsilon and all +the factors that go into beta because + + align:start position:0% +the factors that go into beta because + + + align:start position:0% +the factors that go into beta because +i've lumped them into n1 what i'm saying + + align:start position:0% +i've lumped them into n1 what i'm saying + + + align:start position:0% +i've lumped them into n1 what i'm saying +here + + align:start position:0% +here + + + align:start position:0% +here +is that we've already done a calculation + + align:start position:0% +is that we've already done a calculation + + + align:start position:0% +is that we've already done a calculation +and decided to impose a certain + + align:start position:0% +and decided to impose a certain + + + align:start position:0% +and decided to impose a certain +occupancy restriction on a certain space + + align:start position:0% +occupancy restriction on a certain space + + + align:start position:0% +occupancy restriction on a certain space +based on principles that we've been + + align:start position:0% +based on principles that we've been + + + align:start position:0% +based on principles that we've been +discussing + + align:start position:0% +discussing + + + align:start position:0% +discussing +in this course but now as prevalence + + align:start position:0% +in this course but now as prevalence + + + align:start position:0% +in this course but now as prevalence +goes down according to the simple + + align:start position:0% +goes down according to the simple + + + align:start position:0% +goes down according to the simple +formula whenever n2 + + align:start position:0% +formula whenever n2 + + + align:start position:0% +formula whenever n2 +is bigger than one you know we would use + + align:start position:0% +is bigger than one you know we would use + + + align:start position:0% +is bigger than one you know we would use +this if n2 + + align:start position:0% +this if n2 + + + align:start position:0% +this if n2 +is is bigger than n1 so basically when + + align:start position:0% +is is bigger than n1 so basically when + + + align:start position:0% +is is bigger than n1 so basically when +these two curves cross + + align:start position:0% +these two curves cross + + + align:start position:0% +these two curves cross +as you get to lower prevalence you'll + + align:start position:0% +as you get to lower prevalence you'll + + + align:start position:0% +as you get to lower prevalence you'll +now switch to two and you'll start + + align:start position:0% +now switch to two and you'll start + + + align:start position:0% +now switch to two and you'll start +increasing + + align:start position:0% +increasing + + + align:start position:0% +increasing +and you will do that until you get to n0 + + align:start position:0% +and you will do that until you get to n0 + + + align:start position:0% +and you will do that until you get to n0 +so we'll do this this is the relaxing + + align:start position:0% +so we'll do this this is the relaxing + + + align:start position:0% +so we'll do this this is the relaxing +restrictions and then we'll stop + + align:start position:0% +restrictions and then we'll stop + + + align:start position:0% +restrictions and then we'll stop +and then we'll we'll uh yeah so + + align:start position:0% +and then we'll we'll uh yeah so + + + align:start position:0% +and then we'll we'll uh yeah so +basically we'll go well + + align:start position:0% +basically we'll go well + + + align:start position:0% +basically we'll go well +n2 can when n2 is bigger than we allow + + align:start position:0% +n2 can when n2 is bigger than we allow + + + align:start position:0% +n2 can when n2 is bigger than we allow +this + + align:start position:0% +this + + + align:start position:0% +this +um until uh n2 + + align:start position:0% +um until uh n2 + + + align:start position:0% +um until uh n2 +equals n1 and that's this this this time + + align:start position:0% +equals n1 and that's this this this time + + + align:start position:0% +equals n1 and that's this this this time +here p + + align:start position:0% +here p + + + align:start position:0% +here p +p2 so basically uh we start imposing + + align:start position:0% +p2 so basically uh we start imposing + + + align:start position:0% +p2 so basically uh we start imposing +restrictions at p1 + + align:start position:0% +restrictions at p1 + + + align:start position:0% +restrictions at p1 +so p1 so so basically we start + + align:start position:0% +so p1 so so basically we start + + + align:start position:0% +so p1 so so basically we start +relaxing restrictions when p1 so the + + align:start position:0% +relaxing restrictions when p1 so the + + + align:start position:0% +relaxing restrictions when p1 so the +when the prevalence equals p1 + + align:start position:0% +when the prevalence equals p1 + + + align:start position:0% +when the prevalence equals p1 +that would be uh when + + align:start position:0% +that would be uh when + + + align:start position:0% +that would be uh when +when n2 is equal to n1 and so that would + + align:start position:0% +when n2 is equal to n1 and so that would + + + align:start position:0% +when n2 is equal to n1 and so that would +be + + align:start position:0% +be + + + align:start position:0% +be +when pi p1 + + align:start position:0% +when pi p1 + + + align:start position:0% +when pi p1 +is 1 over n1 + + align:start position:0% +is 1 over n1 + + + align:start position:0% +is 1 over n1 +so essentially that's when you expect to + + align:start position:0% +so essentially that's when you expect to + + + align:start position:0% +so essentially that's when you expect to +find one + + align:start position:0% +find one + + + align:start position:0% +find one +infected person so this is approximately + + align:start position:0% +infected person so this is approximately + + + align:start position:0% +infected person so this is approximately +one over and one so up here + + align:start position:0% +one over and one so up here + + + align:start position:0% +one over and one so up here +you uh when you go below this you're + + align:start position:0% +you uh when you go below this you're + + + align:start position:0% +you uh when you go below this you're +saying well it's actually unlikely that + + align:start position:0% +saying well it's actually unlikely that + + + align:start position:0% +saying well it's actually unlikely that +during the time tau we even get one + + align:start position:0% +during the time tau we even get one + + + align:start position:0% +during the time tau we even get one +infected person + + align:start position:0% +infected person + + + align:start position:0% +infected person +and that's when we start to relax okay + + align:start position:0% +and that's when we start to relax okay + + + align:start position:0% +and that's when we start to relax okay +so that's the first kind of crossover + + align:start position:0% +so that's the first kind of crossover + + + align:start position:0% +so that's the first kind of crossover +point + + align:start position:0% +point + + + align:start position:0% +point +and there's a second crossover point + + align:start position:0% +and there's a second crossover point + + + align:start position:0% +and there's a second crossover point +when this is equal to p2 + + align:start position:0% +when this is equal to p2 + + + align:start position:0% +when this is equal to p2 +sorry is equal to n0 that's what's what + + align:start position:0% +sorry is equal to n0 that's what's what + + + align:start position:0% +sorry is equal to n0 that's what's what +p2 is + + align:start position:0% +p2 is + + + align:start position:0% +p2 is +and so basically uh p2 which is when we + + align:start position:0% +and so basically uh p2 which is when we + + + align:start position:0% +and so basically uh p2 which is when we +would + + align:start position:0% +would + + + align:start position:0% +would +you know hit the saturation point and + + align:start position:0% +you know hit the saturation point and + + + align:start position:0% +you know hit the saturation point and +that's kind of when we've like reopened + + align:start position:0% +that's kind of when we've like reopened + + + align:start position:0% +that's kind of when we've like reopened +in some sense to the full + + align:start position:0% +in some sense to the full + + + align:start position:0% +in some sense to the full +normal situation that would be + + align:start position:0% +normal situation that would be + + + align:start position:0% +normal situation that would be +uh when n2 is equal to n0 + + align:start position:0% +uh when n2 is equal to n0 + + + align:start position:0% +uh when n2 is equal to n0 +wait sorry i wrote here n2 equals n1 + + align:start position:0% +wait sorry i wrote here n2 equals n1 + + + align:start position:0% +wait sorry i wrote here n2 equals n1 +sorry i meant when n2 equals n0 + + align:start position:0% +sorry i meant when n2 equals n0 + + + align:start position:0% +sorry i meant when n2 equals n0 +sorry that's when that's the time p2 + + align:start position:0% +sorry that's when that's the time p2 + + + align:start position:0% +sorry that's when that's the time p2 +here when n2 is equal to n0 that's when + + align:start position:0% +here when n2 is equal to n0 that's when + + + align:start position:0% +here when n2 is equal to n0 that's when +we cut off + + align:start position:0% +we cut off + + + align:start position:0% +we cut off +so this is n0 and we solve for pi + + align:start position:0% +so this is n0 and we solve for pi + + + align:start position:0% +so this is n0 and we solve for pi +you can see that we get n1 + + align:start position:0% +you can see that we get n1 + + + align:start position:0% +you can see that we get n1 +over n0 squared + + align:start position:0% + + + + align:start position:0% + +so that is the place where i then switch + + align:start position:0% +so that is the place where i then switch + + + align:start position:0% +so that is the place where i then switch +and now i'm going to cap the occupancy + + align:start position:0% +and now i'm going to cap the occupancy + + + align:start position:0% +and now i'm going to cap the occupancy +at n0 so maybe to summarize here + + align:start position:0% +at n0 so maybe to summarize here + + + align:start position:0% +at n0 so maybe to summarize here +what i would say is that the occupancy + + align:start position:0% +what i would say is that the occupancy + + + align:start position:0% +what i would say is that the occupancy +should be less than or equal to + + align:start position:0% +should be less than or equal to + + + align:start position:0% +should be less than or equal to +uh n1 for uh + + align:start position:0% +uh n1 for uh + + + align:start position:0% +uh n1 for uh +pi greater than p1 it'll be n2 + + align:start position:0% +pi greater than p1 it'll be n2 + + + align:start position:0% +pi greater than p1 it'll be n2 +which depends on pi for + + align:start position:0% + + + + align:start position:0% + +pi between p1 + + align:start position:0% +pi between p1 + + + align:start position:0% +pi between p1 +or p2 and p1 + + align:start position:0% +or p2 and p1 + + + align:start position:0% +or p2 and p1 +and then as the prevalence gets lower we + + align:start position:0% +and then as the prevalence gets lower we + + + align:start position:0% +and then as the prevalence gets lower we +go to full occupancy n0 + + align:start position:0% +go to full occupancy n0 + + + align:start position:0% +go to full occupancy n0 +when pi is less than p2 + + align:start position:0% +when pi is less than p2 + + + align:start position:0% +when pi is less than p2 +so this is basically this full curve of + + align:start position:0% +so this is basically this full curve of + + + align:start position:0% +so this is basically this full curve of +reopening + + align:start position:0% +reopening + + + align:start position:0% +reopening +and then the final decision to make is + + align:start position:0% +and then the final decision to make is + + + align:start position:0% +and then the final decision to make is +when do we return completely normal and + + align:start position:0% +when do we return completely normal and + + + align:start position:0% +when do we return completely normal and +take away + + align:start position:0% +take away + + + align:start position:0% +take away +certain restrictions we've done so here + + align:start position:0% +certain restrictions we've done so here + + + align:start position:0% +certain restrictions we've done so here +i mentioned mass we could also include + + align:start position:0% +i mentioned mass we could also include + + + align:start position:0% +i mentioned mass we could also include +in this calculation + + align:start position:0% +in this calculation + + + align:start position:0% +in this calculation +you know relaxing other restrictions + + align:start position:0% +you know relaxing other restrictions + + + align:start position:0% +you know relaxing other restrictions +such as maybe not having the ventilation + + align:start position:0% +such as maybe not having the ventilation + + + align:start position:0% +such as maybe not having the ventilation +on + + align:start position:0% +on + + + align:start position:0% +on +quite so high so that would be when we + + align:start position:0% +quite so high so that would be when we + + + align:start position:0% +quite so high so that would be when we +finally go back + + align:start position:0% +finally go back + + + align:start position:0% +finally go back +to no restrictions of any kind we're + + align:start position:0% +to no restrictions of any kind we're + + + align:start position:0% +to no restrictions of any kind we're +sort of back to normal + + align:start position:0% +sort of back to normal + + + align:start position:0% +sort of back to normal +so this means no masks + + align:start position:0% +so this means no masks + + + align:start position:0% +so this means no masks +no other precautions full occupancy + + align:start position:0% +no other precautions full occupancy + + + align:start position:0% +no other precautions full occupancy +so in this case we need r in + + align:start position:0% +so in this case we need r in + + + align:start position:0% +so in this case we need r in +is going to be less than epsilon over + + align:start position:0% + + + + align:start position:0% + +well let's see here it's the same as + + align:start position:0% +well let's see here it's the same as + + + align:start position:0% +well let's see here it's the same as +before we have this p i + + align:start position:0% +before we have this p i + + + align:start position:0% +before we have this p i +n that we just looked at technically + + align:start position:0% +n that we just looked at technically + + + align:start position:0% +n that we just looked at technically +times q i + + align:start position:0% +times q i + + + align:start position:0% +times q i +but now we have another factor pm + + align:start position:0% +but now we have another factor pm + + + align:start position:0% +but now we have another factor pm +squared + + align:start position:0% +squared + + + align:start position:0% +squared +because compared to the case with no + + align:start position:0% +because compared to the case with no + + + align:start position:0% +because compared to the case with no +mass we know the bound in the guidelines + + align:start position:0% +mass we know the bound in the guidelines + + + align:start position:0% +mass we know the bound in the guidelines +so the effect of beta + + align:start position:0% +so the effect of beta + + + align:start position:0% +so the effect of beta +just gets rescaled by pm squared so + + align:start position:0% +just gets rescaled by pm squared so + + + align:start position:0% +just gets rescaled by pm squared so +technically that's + + align:start position:0% +technically that's + + + align:start position:0% +technically that's +that's in uh are in here but now you + + align:start position:0% +that's in uh are in here but now you + + + align:start position:0% +that's in uh are in here but now you +know we have this sort of extra factor + + align:start position:0% +know we have this sort of extra factor + + + align:start position:0% +know we have this sort of extra factor +you kind of think of it like a rescaling + + align:start position:0% +you kind of think of it like a rescaling + + + align:start position:0% +you kind of think of it like a rescaling +of epsilon + + align:start position:0% +of epsilon + + + align:start position:0% +of epsilon +and so what that's going to do for us + + align:start position:0% +and so what that's going to do for us + + + align:start position:0% +and so what that's going to do for us +then + + align:start position:0% +then + + + align:start position:0% +then +is that there's a the uh + + align:start position:0% +is that there's a the uh + + + align:start position:0% +is that there's a the uh +there's another curve that goes + + align:start position:0% +there's another curve that goes + + + align:start position:0% +there's another curve that goes +kind of like this which is just like + + align:start position:0% +kind of like this which is just like + + + align:start position:0% +kind of like this which is just like +this one but it's shifted by a factor + + align:start position:0% +this one but it's shifted by a factor + + + align:start position:0% +this one but it's shifted by a factor +pm cubed rpm squared sorry which is kind + + align:start position:0% +pm cubed rpm squared sorry which is kind + + + align:start position:0% +pm cubed rpm squared sorry which is kind +of like the case where you had so this + + align:start position:0% +of like the case where you had so this + + + align:start position:0% +of like the case where you had so this +is like this is like + + align:start position:0% +is like this is like + + + align:start position:0% +is like this is like +no masks it's like the n2 with no masks + + align:start position:0% +no masks it's like the n2 with no masks + + + align:start position:0% +no masks it's like the n2 with no masks +and the other curve is with + + align:start position:0% +and the other curve is with + + + align:start position:0% +and the other curve is with +masks and there's a rescaling factor + + align:start position:0% +masks and there's a rescaling factor + + + align:start position:0% +masks and there's a rescaling factor +which really has to do with + + align:start position:0% +which really has to do with + + + align:start position:0% +which really has to do with +the sort of remediation that you've done + + align:start position:0% +the sort of remediation that you've done + + + align:start position:0% +the sort of remediation that you've done +and in this case + + align:start position:0% +and in this case + + + align:start position:0% +and in this case +p3 would then just be pm squared + + align:start position:0% +p3 would then just be pm squared + + + align:start position:0% +p3 would then just be pm squared +times p2 so if our pm is a factor of 10 + + align:start position:0% +times p2 so if our pm is a factor of 10 + + + align:start position:0% +times p2 so if our pm is a factor of 10 +percent let's say mass are capturing 10 + + align:start position:0% +percent let's say mass are capturing 10 + + + align:start position:0% +percent let's say mass are capturing 10 +or letting 10 percent of infectious + + align:start position:0% +or letting 10 percent of infectious + + + align:start position:0% +or letting 10 percent of infectious +droplets get through the pm squared + + align:start position:0% +droplets get through the pm squared + + + align:start position:0% +droplets get through the pm squared +might be a factor of 100 + + align:start position:0% +might be a factor of 100 + + + align:start position:0% +might be a factor of 100 +so then we would wait till the + + align:start position:0% +so then we would wait till the + + + align:start position:0% +so then we would wait till the +prevalence is 100 times smaller + + align:start position:0% +prevalence is 100 times smaller + + + align:start position:0% +prevalence is 100 times smaller +before we finally allow people to remove + + align:start position:0% +before we finally allow people to remove + + + align:start position:0% +before we finally allow people to remove +mass and be at full occupancy + + align:start position:0% +mass and be at full occupancy + + + align:start position:0% +mass and be at full occupancy +and you could make a similar calculation + + align:start position:0% +and you could make a similar calculation + + + align:start position:0% +and you could make a similar calculation +for other types of restrictions + + align:start position:0% +for other types of restrictions + + + align:start position:0% +for other types of restrictions +and in fact you can calculate such a + + align:start position:0% +and in fact you can calculate such a + + + align:start position:0% +and in fact you can calculate such a +curve for a given room + + align:start position:0% +curve for a given room + + + align:start position:0% +curve for a given room +given scenario of human behavior + + align:start position:0% +given scenario of human behavior + + + align:start position:0% +given scenario of human behavior +and interventions such as filtration or + + align:start position:0% +and interventions such as filtration or + + + align:start position:0% +and interventions such as filtration or +ventilation + + align:start position:0% +ventilation + + + align:start position:0% +ventilation +and what the theory allows you to do is + + align:start position:0% +and what the theory allows you to do is + + + align:start position:0% +and what the theory allows you to do is +to of course recalculate n1 + + align:start position:0% +to of course recalculate n1 + + + align:start position:0% +to of course recalculate n1 +and then you can recalculate n2 as well + + align:start position:0% +and then you can recalculate n2 as well + + + align:start position:0% +and then you can recalculate n2 as well +and so you can say well what if actually + + align:start position:0% +and so you can say well what if actually + + + align:start position:0% +and so you can say well what if actually +i don't like this curve i would like to + + align:start position:0% +i don't like this curve i would like to + + + align:start position:0% +i don't like this curve i would like to +try to reopen my school + + align:start position:0% +try to reopen my school + + + align:start position:0% +try to reopen my school +sooner okay how would i do that well i + + align:start position:0% +sooner okay how would i do that well i + + + align:start position:0% +sooner okay how would i do that well i +know that if i + + align:start position:0% +know that if i + + + align:start position:0% +know that if i +make various interventions i can raise + + align:start position:0% +make various interventions i can raise + + + align:start position:0% +make various interventions i can raise +the pink curve so i can end up somewhere + + align:start position:0% +the pink curve so i can end up somewhere + + + align:start position:0% +the pink curve so i can end up somewhere +here let's just say + + align:start position:0% +here let's just say + + + align:start position:0% +here let's just say +this might be with uh + + align:start position:0% +this might be with uh + + + align:start position:0% +this might be with uh +safety interventions + + align:start position:0% + + + + align:start position:0% + +actually one such innervation + + align:start position:0% +actually one such innervation + + + align:start position:0% +actually one such innervation +intervention by the way is masks + + align:start position:0% +intervention by the way is masks + + + align:start position:0% +intervention by the way is masks +themselves because if i follow this + + align:start position:0% +themselves because if i follow this + + + align:start position:0% +themselves because if i follow this +curve all the way down here there's some + + align:start position:0% +curve all the way down here there's some + + + align:start position:0% +curve all the way down here there's some +curve down here which is no masks + + align:start position:0% +curve down here which is no masks + + + align:start position:0% +curve down here which is no masks +which is the safety guideline with no + + align:start position:0% +which is the safety guideline with no + + + align:start position:0% +which is the safety guideline with no +mass and if i turn on mass + + align:start position:0% +mass and if i turn on mass + + + align:start position:0% +mass and if i turn on mass +i go up okay but when i make that + + align:start position:0% +i go up okay but when i make that + + + align:start position:0% +i go up okay but when i make that +intervention + + align:start position:0% +intervention + + + align:start position:0% +intervention +also p2 notice scales like like uh + + align:start position:0% +also p2 notice scales like like uh + + + align:start position:0% +also p2 notice scales like like uh +also like n1 and so that's actually + + align:start position:0% +also like n1 and so that's actually + + + align:start position:0% +also like n1 and so that's actually +moving in this direction + + align:start position:0% +moving in this direction + + + align:start position:0% +moving in this direction +and so i've essentially moved this + + align:start position:0% +and so i've essentially moved this + + + align:start position:0% +and so i've essentially moved this +yellow curve and so + + align:start position:0% +yellow curve and so + + + align:start position:0% +yellow curve and so +i'm i'm now going to say well you know + + align:start position:0% +i'm i'm now going to say well you know + + + align:start position:0% +i'm i'm now going to say well you know +with a different set + + align:start position:0% +with a different set + + + align:start position:0% +with a different set +of of interventions i can make the room + + align:start position:0% +of of interventions i can make the room + + + align:start position:0% +of of interventions i can make the room +safer + + align:start position:0% +safer + + + align:start position:0% +safer +and what that does it gives me more + + align:start position:0% +and what that does it gives me more + + + align:start position:0% +and what that does it gives me more +people in the room but it also + + align:start position:0% +people in the room but it also + + + align:start position:0% +people in the room but it also +means that i can that i change sort of + + align:start position:0% +means that i can that i change sort of + + + align:start position:0% +means that i can that i change sort of +when i make the decision reopen in + + align:start position:0% +when i make the decision reopen in + + + align:start position:0% +when i make the decision reopen in +particular i can kind of get myself to + + align:start position:0% +particular i can kind of get myself to + + + align:start position:0% +particular i can kind of get myself to +full occupancy at a higher prevalence + + align:start position:0% +full occupancy at a higher prevalence + + + align:start position:0% +full occupancy at a higher prevalence +because the room is actually now made + + align:start position:0% +because the room is actually now made + + + align:start position:0% +because the room is actually now made +safer + + align:start position:0% +safer + + + align:start position:0% +safer +so uh i noted but on the other hand this + + align:start position:0% +so uh i noted but on the other hand this + + + align:start position:0% +so uh i noted but on the other hand this +this + + align:start position:0% +this + + + align:start position:0% +this +this switch here was at one over n1 so + + align:start position:0% +this switch here was at one over n1 so + + + align:start position:0% +this switch here was at one over n1 so +kind of this this part kind of shrinks a + + align:start position:0% +kind of this this part kind of shrinks a + + + align:start position:0% +kind of this this part kind of shrinks a +little bit + + align:start position:0% +little bit + + + align:start position:0% +little bit +as this ultimately kind of goes up to + + align:start position:0% +as this ultimately kind of goes up to + + + align:start position:0% +as this ultimately kind of goes up to +full occupancy + + align:start position:0% +full occupancy + + + align:start position:0% +full occupancy +so so basically um i think compared to + + align:start position:0% +so so basically um i think compared to + + + align:start position:0% +so so basically um i think compared to +the + + align:start position:0% +the + + + align:start position:0% +the +current situation or the typical + + align:start position:0% +current situation or the typical + + + align:start position:0% +current situation or the typical +situation where policy makers are making + + align:start position:0% +situation where policy makers are making + + + align:start position:0% +situation where policy makers are making +decisions + + align:start position:0% +decisions + + + align:start position:0% +decisions +based on something like the six-foot + + align:start position:0% +based on something like the six-foot + + + align:start position:0% +based on something like the six-foot +rule and you know a somewhat + + align:start position:0% +rule and you know a somewhat + + + align:start position:0% +rule and you know a somewhat +arbitrary feeling about what is a high + + align:start position:0% +arbitrary feeling about what is a high + + + align:start position:0% +arbitrary feeling about what is a high +prevalence is it one percent is it point + + align:start position:0% +prevalence is it one percent is it point + + + align:start position:0% +prevalence is it one percent is it point +one percent and we decide okay now we + + align:start position:0% +one percent and we decide okay now we + + + align:start position:0% +one percent and we decide okay now we +can close our schools or reopen our + + align:start position:0% +can close our schools or reopen our + + + align:start position:0% +can close our schools or reopen our +schools or set the occupancy at half + + align:start position:0% +schools or set the occupancy at half + + + align:start position:0% +schools or set the occupancy at half +the guideline tells you how to set + + align:start position:0% +the guideline tells you how to set + + + align:start position:0% +the guideline tells you how to set +occupancy for sort of the worst case + + align:start position:0% +occupancy for sort of the worst case + + + align:start position:0% +occupancy for sort of the worst case +scenario when the pandemic is is is is + + align:start position:0% +scenario when the pandemic is is is is + + + align:start position:0% +scenario when the pandemic is is is is +is + + align:start position:0% +is + + + align:start position:0% +is +very wide you know prevalent in society + + align:start position:0% +very wide you know prevalent in society + + + align:start position:0% +very wide you know prevalent in society +but now also through these kinds of + + align:start position:0% +but now also through these kinds of + + + align:start position:0% +but now also through these kinds of +calculations we can make rational + + align:start position:0% +calculations we can make rational + + + align:start position:0% +calculations we can make rational +decisions about how to reopen + + align:start position:0% +decisions about how to reopen + + + align:start position:0% +decisions about how to reopen +i'm not advocating necessarily for the + + align:start position:0% +i'm not advocating necessarily for the + + + align:start position:0% +i'm not advocating necessarily for the +exact formulas that you find on the + + align:start position:0% +exact formulas that you find on the + + + align:start position:0% +exact formulas that you find on the +board here + + align:start position:0% +board here + + + align:start position:0% +board here +but the principles i'm showing you could + + align:start position:0% +but the principles i'm showing you could + + + align:start position:0% +but the principles i'm showing you could +lead to quantitative and scientifically + + align:start position:0% +lead to quantitative and scientifically + + + align:start position:0% +lead to quantitative and scientifically +justifiable ways + + align:start position:0% +justifiable ways + + + align:start position:0% +justifiable ways +of taking a specific space and a + + align:start position:0% +of taking a specific space and a + + + align:start position:0% +of taking a specific space and a +specific usage of that space and + + align:start position:0% +specific usage of that space and + + + align:start position:0% +specific usage of that space and +deciding how to close as prevalence goes + + align:start position:0% +deciding how to close as prevalence goes + + + align:start position:0% +deciding how to close as prevalence goes +up + + align:start position:0% +up + + + align:start position:0% +up +and reopen as prevalence goes down + + align:start position:0% +and reopen as prevalence goes down + + + align:start position:0% +and reopen as prevalence goes down +including ultimately returning to normal + + align:start position:0% +including ultimately returning to normal + + + align:start position:0% +including ultimately returning to normal +and removing mass + + align:start position:0% +and removing mass + + + align:start position:0% +and removing mass +and all other forms of precaution as the + + align:start position:0% +and all other forms of precaution as the + + + align:start position:0% +and all other forms of precaution as the +epidemic disappears \ No newline at end of file diff --git a/m00PjHTq6jU.txt b/m00PjHTq6jU.txt new file mode 100644 index 0000000000000000000000000000000000000000..a97e35334bb9c59f76327ff77d88904f8ab9a605 --- /dev/null +++ b/m00PjHTq6jU.txt @@ -0,0 +1,3649 @@ +The following +content is provided + +under a Creative +Commons license. + +Your support will help MIT +OpenCourseWare continue + +to offer high-quality +educational resources for free. + +To make a donation, or to +view additional materials + +from hundreds of MIT courses, +visit MIT OpenCourseWare + +at ocw.mit.edu. + +PROFESSOR: I think +it's a good idea + +to review where we +were because we're + +kind of in the middle +of a discussion. + +We're actually on part three. + +And probably, there will +be four parts all together + +of our discussion of +homogeneous expansion. + +So I have a few slides to just +review where we were last time. + +We were building a mathematical +model of our homogeneously + +expanding universe. + +And we modeled it as +a finite-sized sphere + +where we promised +that in the end + +we will take the limit as +the size of that sphere + +goes to infinity and +fills all the space. + +But it started with some +initial maximum, R max i, i + +for initial. + +We arranged for it to have +a uniform density, rho. + +We started at a +time called t sub i. + +There were some initial +maximum radius, R max i. + +And we also set this up to +exhibit Hubble expansion. + +And we're going to +try to calculate + +how it evolves from there. + +But we're going to start +it Hubble expanding. + +And Hubble expanding +means that we're + +starting with every particle +having an initial velocity + +which is a constant, H sub i, +the initial value of the Hubble + +expansion rate, +times the vector r. + +That is, the vector that goes +from the origin to the point + +where the particle is located. + +And that corresponds +to Hubble expansion + +centered on the +center of our sphere. + +So these are our +initial conditions. + +We just put them in +by hand because we + +think they form a good model for +what our universe looks like. + +And then, the laws of +evolution should take over + +to govern what's +going to happen later. + +And since we haven't +studied general relativity, + +we'll be using +Newton's law of gravity + +to discover how it behaves. + +But I promised you +at the beginning + +that we will, in fact, get +exactly the same equation + +that we would have gotten had +we used general relativity. + +And we'll talk later +today, probably, + +about why that's the case. + +So this is the initial setup. + +Any questions about +the initial setup? + +OK, then we derived +a lot of equations. + +And everything really +follows from the statement + +at the top here, which is +understanding what Newton tells + +us about the gravitational +field of a spherical shell. + +We could always think +of our solid sphere + +as being made up of shells. + +So if we know how +a shell behaves, + +we know all we need to know. + +And Newton told us. + +He told us that inside a +spherical shell, the effect + +of gravity, which I'm +describing in terms + +of the gravitational +acceleration vector, little g, + +inside a shell, the +gravitational field is exactly + +0. + +The force is coming from all +different parts of the shell, + +pulling outward, +cancel each other. + +And the net force on any object +anywhere inside the shell + +is exactly 0. + +Outside, the entire +shell acts exactly + +as if it were a single +point mass located + +at the origin with the +same total mass, m. + +So incredibly simple. + +It's hard to believe it's +so simple, but it is. + +By the way, if you use +Gauss's law of gravity, + +it becomes very obvious +that those statements + +are the right statements. + +Newton know about +Gauss's law of gravity, + +so Newton derived +those statements + +by brute force +integration, which + +is more of a tour de force. + +But something Newton was +capable of doing it, and he did. + +To describe how the +system is going to evolve, + +moving onward, we introduce +something that's a little bit + +complicated, a function r, which +is a function of two variables, + +r sub i and t. + +And r represents +the radius at time t + +of the shell that was +initially at radius r sub i. + +And our goal here is not just +to keep track of the particle + +on the outside, +which is for example, + +what Ryden does in her textbook. + +Ryden assumes that +everything stays homogeneous. + +And then if you follow what +happens to the outer edge, + +you know everything. + +But we're not going to +make that assumption. + +We're going to conclude +that it remains homogeneous, + +but we're going to derive it. + +Which means that we need to know +the motion of every particle + +inside the sphere +to be able to tell + +if it's going to +stay homogeneous. + +And that's why we're introducing +this more general description + +where r is a +function of r sub i. + +So that function of +the extra variable + +will tell us how every particle +moves as the system evolves. + +We know that we're going to +maintain spherical symmetry + +because we start with +spherical symmetry + +and the force law respects +spherical symmetry. + +So we're building that +in from the beginning. + +We're not allowing things to +depend on angular variables + +theta or phi. + +But assuming spherical +symmetry, motion just + +is described entirely by +giving the r-coordinate + +of each particle. + +And this function r of r i +t does that-- exactly that. + +Then, we said that +at a given radius, + +this description +about shells tells us + +that the shells that +are outside that radius + +don't do anything +at a given radius. + +But the shells that are +inside act like a point mass, + +as if it was all at the origin. + +So to understand how a given +shell is going to evolve, + +all we really need to +know is the total mass + +inside that shell. + +And that's given +by M of r sub i, + +the mass inside the +shell at radius r sub i. + +And that's just the +volume of the shell + +initially times the +initial mass density. + +As these shells move, the +total mass inside a shell + +will remain exactly +the same as it + +was as long as there's +no crossings of shells. + +Now, the shell crossing +issue is hard to talk about. + +But in the end, it +just doesn't happen + +so you don't need +to worry about it. + +But the argument was +that initially we + +know the shells are moving +apart from each other + +because we built in +this Hubble expansion + +where everything is moving +away from everything else. + +So if shells are +ever going to cross, + +they're not going to +cross immediately. + +It will take some time for +these velocities to reverse, + +and the shells that were moving +apart to move together and hit. + +So there's unambiguously +at least a period of time + +where there are no +shell crossings. + +And we could write +down the equations + +that describe the motion +during this period + +where there are no +shell crossings. + +Now, if there was going +to be a shell crossing, + +the equations that +we're writing down + +would have to hold +right up until the time + +of that first crossing. + +Because as long as +there's no crossings, + +our equations are valid. + +Which means that if there was +going to be a shell crossing, + +the equations we're writing +down had better show it. + +Because the equations +that we're writing down + +have to be valid right +up until the instant + +of any possible shell crossing. + +And what we're going to +find is that the equations + +are going to lead to just +homogeneous evolution + +where there are no +shell crossings. + +And therefore, that's +the conclusion. + +If there were going to +be any shell crossings, + +these equations would +have to show it. + +They don't show it, so there +are no shell crossings. + +So it's a complicated +paragraph, but the bottom line + +is simple- we can +ignore shell crossings. + +And that means that the total +mass inside of any shell + +will remain exactly +constant with time + +given by its initial value. + +And this formula is +the initial value. + +And therefore, it +holds at all time. + +Any questions about that? + +Any questions about the +shell crossing issue? + +OK, good. + +So whoops, sorry about that. + +So M of r sub i is the mass +inside the shell at radius r + +sub i. + +And then we can write down-- now +we use Newton's law of gravity + +directly. + +We can write down +the acceleration + +of a given particle in +terms of its radius r + +and its initial radius r sub i. + +Its initial radius determines +how much mass is inside. + +M of r sub i is +independent of time. + +But the actual radius it's +at determines how far away + +it is, or describes how far +away it is from the origin. + +And that's the 1 over r squared +that appears in the force law. + +So we have the time dependent r +in the denominator and the time + +independent initial r sub i +that appears in the numerator. + +And it's all proportional +to a unit vector r + +hat pulling everything +radially inward + +because of the +minus sign in front. + +So gravity is pulling +everything inward, + +which is what we'd expect. + +So this formula is +the key formula. + +It's a vector +formula, but we know + +that all the motion is radial. + +So all we really +have to keep track + +of is the radius as +a function of time. + +So we can turn +this vector formula + +into a formula for +little r itself. + +Just the radius number, +the radial coordinate. + +And we get r double dot is minus +4 pi over 3 G r sub i cubed rho + +sub i, taking the +formula for M of ri + +from the line above +divided by r squared. + +And the r in this formula-- +I didn't write the arguments, + +but it means this +function r, which + +is a function of two +arguments, r sub i and t. + +So this differential equation +now governs our entire system + +and tells us everything +we need to know + +or everything we can know +about the actual dynamics. + +But to solve a +differential equation + +of that sort, a second +order differential equation, + +we need initial conditions. + +And we already described the +initial conditions in words. + +Now we have to just figure out +what those initial conditions + +are saying about r and r dot. + +And the answer is +straightforward. + +We argued it last time. + +The initial conditions +are that r at time t + +sub i is just r sub i. + +That was really the definition +of r sub i in the first place. + +And r dot is just H +sub i times v coming + +from the formula we had +for the initial velocities. + +So these three equations, +the two initial conditions + +and the differential +equation, lead in principle + +to a mathematical solution +that's completely unique + +and determined by +those equations. + +And our goal now is +just to figure out + +what that solution looks like. + +And we discovered a +marvelous scaling property. + +That is, instead +of talking about r, + +we divided r by r sub i and +defined a new function, which + +we initially called u. + +Initially, thinking +of it as a function + +of these two variables. + +We can write down +new equations for u. + +And those equations +end up not having + +any r sub i's in them at all. + +And once we realized +that, we realized + +we don't need to call +it u of r sub i and t. + +It's really just +a function of t. + +And at that point, we +renamed it because we also + +realized that it actually +is our old friend the scale + +factor, a of t. + +So a of t is just r of r sub +i and t divided by r sub i. + +And then the reason +this is a scale + +factor is seen most clearly from +that equation, which is really + +this equation just rearranged. + +The physical distance of +a particle from the origin + +is equal to the scale +factor times r sub i + +where r sub i plays the role +of the coordinate distance. + +r sub i is a time-independent +measure indicating + +which shell you're +talking about. + +So the equations for a then +are the equations for u, + +which are the equations for +r just divided by r sub i. + +And we can write down +what those equations are. + +We have a differential +equation for a + +and two initial +conditions where r + +sub i has dropped +out all together. + +The differential equation +is given immediately + +from the one we had up +here, but we could also we + +write it in terms +of what rho of t is. + +I didn't write the +equation here because I + +guess I was running out of room. + +But we also figured out +how rho of t behaves. + +And it behaves in +the obvious way. + +As the space +expands, the density + +just goes down as the volume. + +And the volume grows like a +cubed, the cube of the scale + +factor, because volume's +proportional to radius cubed. + +So rho of t is just rho sub +i divided by a of t cubed. + +And putting that in, we +can go from that equation + +to this equation. + +And this equation makes +no reference anymore + +to the initial time. + +It's just an equation for what +deceleration you see, what + +value of a double dot +you see, as a function + +of the mass density +and a itself. + +OK, any questions about any +of those differential equation + +manipulations? + +Yes. + +AUDIENCE: In the homework, it +says that this equation is not + +entirely general. + +We can't use it in all cases. + +Whereas, the other version +that we get from the energy + +conservation is completely OK? + +PROFESSOR: That is correct, yes. + +AUDIENCE: It says it in +there, but why is that? + +PROFESSOR: Why is it true? + +Well, as long as you have only +non-relativistic matter, which + +is what we're +talking about here, + +both of these-- this +equation is golden + +and so is the equation +we're about to talk + +about the derivation of, +the conservation of energy + +equation. + +So as long as we have the +context in which we derived it, + +it's completely valid. + +But on the homework +set, we're talking + +about more general cases. + +We gave a different formula +for the scale factor, + +which corresponds to a +different situation in terms + +of the underlying materials +that are building that universe. + +And where the change +occurs is when + +one introduces a +nonzero pressure. + +This gas of particles +that we're talking about + +is just non-relativistic +particles + +moving with the +Hubble expansion. + +There's no internal velocity +which generates a pressure. + +And it's pressure that +makes a difference. + +This formula assume +zero pressure. + +We will learn later +how to correct it + +when there's a nonzero pressure. + +And the other formula +doesn't depend on pressure, + +so it's valid whether +there's pressure or not. + +But at the moment, we have +no real way of knowing that. + +We'll talk later +about why that's true. + +Other questions? + +No. + +OK, great. + +OK, one more slide here, +not too much on it. + +At the end of the last +class, we took the equation + +that I just wrote on +the previous slide. + +I just copied it to this slide, +the equation for a double dot, + +written in terms of the +initial mass density. + +And discovered that it +can be integrated once + +to produce a kind of a +conservation of energy + +equation. + +And all you do is +you start with this, + +write it by putting everything +on one side of the equation, + +a double dot plus 4 pi over 3 G +rho i over a squared equals 0. + +And then, multiply the +whole equation by a dot. + +And a dot is called +an integrating factor. + +It turns the expression +into a total derivative. + +So once you write +it this way, it + +is equivalent to dE dt +equals 0, where e is just + +defined to be this +quantity that would + +have better as a +triple equal sign. + +e is just defined +to be that quantity. + +And if you then write +down what dE dt means, + +it means exactly that. + +So it's the same equation. + +So given our second +order equation, + +we can write down a +first order equation, + +which is that E is +equal to a constant. + +And we commented last time that +the physical interpretation + +of E is-- I'm not +sure what to say. + +There are multiple physical +interpretations of E + +is probably what I want to say. + +And one physical +interpretation is + +if you multiply by +the right factors, + +it does describe the actual +energy of a test particle + +just on the boundary of our +sphere, on the outer boundary. + +It doesn't really describe +directly the total energy + +of a particle inside that +sphere because calculating + +the potential energy of a +particle inside the sphere + +is more complicated. + +And it doesn't give +you the simple answer. + +So it doesn't really describe +particles on the inside, + +except you could argue +that if you-- talking + +about a particle on the inside, +the particles outside of it + +don't matter. + +And you pretend +they're not there. + +And then it does +describe the energy. + +That is, you could +think of any particle + +as being on the +outside of the sphere + +and ignore what's outside it. + +But that's extra sentences +that you have to put in. + +On the homework, you +will also discover + +that for this finite-sized +Newtonian sphere, + +there's certainly a +well-defined Newtonian + +expression for the total +energy of the sphere. + +And that's also +proportional to this E. + +So by multiplying it +by different constant, + +you can turn it into the +total energy of the sphere. + +So it's actually +related to energy + +and it's definitely conserved. + +Those are the important +statements to takeaway. + +And that's where we +left off last time. + +And we'll pick up from +there now pretty much + +on the blackboard for +the rest of lecture. + +Are there any further +questions about these slides? + +OK. + +In that case, we will go on. + +The first thing I want to do is +to take the same conservation + +law that we have up +there and rewrite it + +in a way that's +more conventional. + +And perhaps, more useful. + +But certainly, +more conventional. + +We started with knowing that a +quantity called E is conserved. + +And it's equal to 1/2 a dot +squared minus 4 pi over 3 + +G rho i over a. + +OK, then we also +know that rho of t + +is equal to rho sub i divided +by a cubed of t, which just says + +that matter thins out with +the volume which grows + +as the cube of the scale factor. + +And that can be used to +manipulate this equation. + +For reasons that will +become clearer in a minute, + +I'm just going to manipulate +this equation by multiplying it + +by 2 over a squared. + +Just because this will +get me the equation + +I'm trying to get to. + +So if I multiply the left-hand +side by 2 over a squared, + +I have to multiply the +right-hand side by 2 + +over a squared. + +The 2 cancels the half. + +The first term becomes +a dot over a squared. + +And you might remember the a dot +over a is the Hubble expansion + +rate, so it has some +physical significance. + +And then, minus the 2 turns the +4 pi over 3 into 8 pi over 3. + +And the a squared multiplies +the a to make an a cubed. + +And then here, we have +rho i over a cubed, which + +in fact is just the +current value of rho. + +So we can rewrite this as a +dot over a squared minus 8 pi + +over 3 G rho. + +No a's anymore on +the right-hand side. + +Well, on a's anymore +in this term. + +OK, now the convention +that brings our notation + +into contact with the +rest of the world. + +Nobody talks about +E, by the way. + +That's just my convention. + +But to make contact +with the rest + +of the world, the rest +of the world talks + +about a number called +little k, lowercase k. + +And it connects to our notation +by being equal to minus 2E + +divided by c squared. + +And with that connection, we +can write our conservation law + +in what is the standard +way of writing it, + +at least in many textbooks. + +And that's it. + +So I put a box around it. + +And this equation was first +derived by Alexander Friedmann + +using general +relativity in 1922. + +And it is, therefore, usually +called the Friedmann equation. + +Alexander Friedmann, by the +way, was a Russian meteorologist + +by profession. + +But as a meteorologist, +he knew a lot + +about differential equations. + +And when general relativity came +out, he got interested in it + +and was the first person to +derive using general relativity + +the equations that described +an expanding universe. + +And he wrote two famous +papers-- now famous papers-- + +in 1922 and 1923. + +One of them talking about +the system of equations + +where k is positive +and another talking + +about where it's negative. + +I forget which +order they were in. + +But they correspond to +open and closed universes, + +which we'll talk about +more in a few minutes. + +Now, I just should remind you +to have our equations together. + +We also had the all-important +equation for a double dot. + +And as I was just describing +an answer to a question, + +we don't know yet how +to generalize this + +to other kinds of matter besides +the non non-relativistic dust + +that we just derived them for. + +They're certainly both correct +for our non-relativistic dust. + +But when we try to generalize +them, what we'll find + +is that the top equation +will remain true exactly + +for any kind of matter, while +the bottom equation assumes + +that pressure equals 0. + +Now, the standard terminology +is to call the top equation + +the Friedmann equation. + +In fact, both of +these equations, + +with this one including the +pressure term that we don't + +have yet, appeared in +Friedmann's original papers. + +So I usually refer to +these two equations + +as the Friedmann +equations-- plural. + +But many textbooks refer to just +the top one as the Friedmann + +equation and don't give a +name to that equation, which + +is also OK if you want. + +Yes. + +AUDIENCE: Didn't we +get the top equation + +from the bottom equation? + +PROFESSOR: We did. + +That's right. + +So how does that jive? + +The answer is-- and we'll +be coming to this later. + +But the answer is that when +we got the top equation + +from the bottom equation, +we used that equation. + +And this equation +will no longer hold + +when there's a +significant pressure. + +And in fact, when we derive +it later-- I forget what order + +we'll do things in. + +But we'll make sure that +all three of these equations + +are consistent when +we include pressure. + +The reason the top +equation changes + +if you include pressure-- +may not be obvious. + +But if I tell you +why it happens, + +it will become obvious. + +The top equation looks like +it's just how things thin out. + +Like a cubed. + +But rho is the +total mass density. + +And relativistically, it's +equivalent to the energy + +density. + +If you just multiply +by c squared, + +that becomes the energy +density by the E equals + +mc squared equality. + +So it's a question of +how much energy there + +is inside this sphere or box. + +And if you imagine +a box changing size, + +if it's filled with a gas +with a positive pressure, + +as that box changes +size, the pressure + +does work on the boundary. + +If you think of it as a piston. + +And if we have a positive +pressure and a gas expands, + +it loses energy. + +And relativistically, that +means it has to also lose mass. + +The total mass inside the +box does not remain constant + +as it expands, which +is the idea that we + +use when we derive that +rho i over a cubed. + +So rho i over a cubed +is the right behavior + +for the total mass +density or energy + +density for a zero pressure gas. + +But when you include +pressure and take + +into account relativity, that's +not the right formula anymore. + +AUDIENCE: The top one, it +just cancels out somehow? + +PROFESSOR: Well, the pressure +ends up canceling out, + +so that this ends +up still being true + +and this ends up +being different. + +And we'll see later +how it happens. + +I just want to indicate where +the changes are going to be. + +We'll see what the changes +are when we get there. + +AUDIENCE: What happened +to the third factor + +of a in the second equation? + +PROFESSOR: There's a +factor of a missing, sorry. + +Yes, thank you very much. + +It's important to get +the equations right. + +That wasn't +Friedmann's equation. + +That was Alan's equation. + +Now it's Friedmann's equation. + +He got it right. + +OK, any other errors or +questions to bring up? + +OK. + +Now is probably a good time to +talk about the question of why + +we were so fortunate to discover +that the Friedmann equation + +that we derived agrees exactly +with general relativity. + +There is a simple reason for it. + +I don't think it's +an accident at all. + +The reason for it, +as I understand it, + +is that we assume +from the beginning-- + +and we would be assuming +this whether we're + +talking about the +Newtonian calculation + +or the corresponding general +relativity calculation. + +We assume from the +beginning that we + +are modeling a completely +homogeneous system, where + +every part of it is identical +to every other part. + +And once you assume +that homogeneity, + +it means that if you know +what happens in a little box, + +a meter by a meter +by a meter say. + +If you know what +happens in a little box, + +you know what happens +everywhere because you assume + +that what happens everywhere +is exactly the same as what's + +happening in that box. + +So that implies +that if Newton is + +right for what +happens in the box, + +Newton has to be +right for what's + +happening in the universe. + +And we do expect +Newtonian physics + +to work on small scales, +scales of a meter, + +and small velocities. + +The Hubble expansion of +a meter is negligible. + +So we expect Newton to give +us a proper description of how + +the system is behaving +on small scales. + +And the assumption +of homogeneity + +guarantees that if you +understand the small scales, + +you also understand +the large scales. + +So I think we are guaranteed +that this had better give us + +the same results as +general relativity or else + +Newtonian physics is +not the proper limit + +of general relativity. + +But it is. + +We would not accept +general relativity + +if it did not give +Newtonian physics + +for small scales +and low velocities. + +So we expect to get the +same answer as Gr and we do. + +This is exactly +what Gr would give. + +And this is exactly what Gr +would give also for the case + +where there's no pressure-- +the case we're doing. + +OK, any questions about that? + +OK, next item. + +I would like to +say a couple words + +about the units in +which we're going + +to define these quantities. + +So far, in our +mathematical model, + +r and r sub i are distances. + +And therefore, they're +measured in whatever units + +you're using to +measure distances. + +And I'll pretend +we're using SI units. + +So I'll say meters. + +We could use light +years, or whatever. + +It doesn't really matter. + +But they're both measured +in ordinary distance units. + +And earlier when we talked +about scale factors and things, + +I told you that many +books do it this way. + +Think of both the +co-moving coordinates + +and the physical distances +as being measured + +in meters and the scale +factor being dimensionless. + +But I told you I don't +like to do it that way + +because I think it's +clearer to recognize + +that these co-moving +coordinates don't have + +any real relationship +to actual distances. + +At least not as time changes. + +So for me, it's better +to have a different unit + +to describe the co-moving +coordinate systems. + +So I would like to +introduce that here. + +And all I need to do really is +say that let the unit of r sub + +i be called a notch. + +Now, we already +called it a meter, + +but that doesn't really +mean that a meter is + +the same as a notch. + +Because when we +called it a meter, + +we were not really +taking into account + +the fact that it's only +a meter at time t sub i. + +So another way of +describing this definition, + +which might not sound like we're +trying to redefine the meter, + +is to say that the statement r +sub i equals 5 notches, which + +is the kind of statement I'm +going to make now because I'm + +only going to talk about r +sub i measured in notches. + +When I say r sub i +is 5 notches, that's + +equivalent to saying that the +particle labeled by r sub i + +equals 5-- 5 notches-- was +at 5 meters from the origin + +at time t sub i. + +So giving the value of a +co-moving coordinate in notches + +tells you exactly +what distance it + +was from the origin +at time t sub i. + +Now, the reason why I don't +use this to just say, well, + +why don't we call it +meters, is that we're now + +going to forget about t sub i. + +If you look at +equations we have, + +t sub i no longer +appears in any of them. + +t sub i was just our +way of getting started. + +And we could have started +at any time we wanted. + +And once we have +these equations, + +we can talk about times +earlier than t sub + +i, times later than t sub i. + +And there's nothing special +about t sub i anymore. + +But r sub i we're going to +keep as our permanent label + +for every shell, which means +for every particle there will be + +a value of r sub i attached +to that particle which will be + +maintained as the +system evolves. + +And it will be clearly +playing the role + +of what we've called the +co-moving coordinate. + +And therefore, we will +want to keep r sub i + +and we'll want to call +its unit something. + +And I'm just saying I'm +going to call them notches. + +You can call them +meters if you want, + +but I'm going to +call them notches. + +So using this language, I'm not +changing any of the equations + +that we wrote. + +So we will still have r being +equal to a of t times r sub i. + +But now, r will be +measured in meters. + +a of t I will think of +as meters per notch. + +And r sub i will me +measured in notches. + +And the scale factor a of t +will be playing the same role + +it played ever since we +introduced the word scale + +factor. + +It just means that when +the scale factor doubles, + +all distances in our +model double exactly. + +Now that we have the sort +of new system of units, + +I just want to work out +the units of an object + +where the units are +not all obvious. + +What are the units of +this thing that we've + +defined that we called k, +which is related to this thing + +that we defined that was called +E, where E was not really + +an energy? + +But we can work out what k is. + +I'm using square brackets +to mean units of. + +k can be thought of as being +defined by this equation. + +Or in any case, this +equation certainly + +must be dimensionally +consistent because we derived + +it and you didn't point out +that I made any mistakes, + +so I must not have. + +So the units of kc +squared over a squared + +should be the same as the +units of a dot squared + +over a squared. + +And if I multiply through +to write units of k-- + +to relate them to a dot, +we get the units of k + +have to be the same +as the units of 1/c + +squared times a dot squared. + +The a squareds in +the denominator + +here just cancel each other. + +So the units of k has to be +the same as the units of 1/c + +squared a dot squared. + +And we know what they are. + +The units of 1/c squared +is second squared + +per meter squared. + +Meter per second +squared, but upside down. + +That's the 1/c squared factor. + +And a dot is meters per notch +per second because of the dot. + +So meters per notch would be a. + +a dot would have +an extra second. + +And the whole thing gets +squared because it's + +a dot squared here. + +And you see then that +the meter squares cancel. + +The second squareds cancel. + +And we just get the peculiar +answer 1 over a notch squared. + +Now, there's probably not a +lot of intuition behind that. + +But what it clearly +does say is that we + +can make k change its +numerical value by changing + +our value for the notch. + +And that's important to know. + +And it's a clear consequence +of what we just did. + +So now we can talk about +different conventions + +that people use for +defining the notch. + +And hence, k, which are +clearly related to each other + +we've now learned. + +So first of all, in the +construction that we just + +did-- starting out with our +sphere, and letting it grow, + +and defining the maximum sphere +as r max comma i and so on. + +In that construction, our +initial value of t-- excuse + +me, our initial value +of a, a of ti, was one. + +And the way we +first did it where + +all lengths were +measured in meters. + +And with our new definition that +r sub i is measured in notches + +so that a is meters +per notch, it + +means that in the system +we just had, a of t sub + +i was 1 meter per notch. + +And since we +already did this, we + +don't really want to change it. + +But I point out that t sub i, +if you look at our equations, + +survives in only one place, +which is in this equation. + +It has disappeared from +every other equation + +we're going to be keeping. + +So we are perfectly safe in just +forgetting about this equation. + +Or if we want to +remember about it, + +we could just say, well, yeah, +t sub i had some significance. + +It was the time at which +the scale factor happened + +to have been equal to +1 meters per notch. + +But otherwise, it +has no importance. + +There's a different time +when the scale factor was + +10 meters per notch, or +1 light year per notch. + +So since t sub i is of +no relevance whatever, + +we can safely forget +the above equation. + +Or we could think of it as +the definition of t sub i, + +where we don't care +anything else about t sub i. + +So it was just some +symbol that was + +used in some +earlier calculation. + +So we now just have a +scale factor a of t. + +And we can talk about how +we might normalize it. + +And there are basically +two important conventions + +that are in use in textbooks. + +Some textbooks, which include +Barbara Ryden's textbook + +that we're using, +define a of t to be + +equal to 1, which I will call +1 meter per not much today. + +So a of t is just defined to be +1 today as a common notation. + +It's notation that +Barbara Ryden uses. + +And that makes a notch +equal to a meter today. + +There's another +common convention, + +which is to recognize that since +k has units 1 over notches, + +we can make k any value we +want without changing any + +of the physics, just changing +our definition of the notch, + +which is up for grabs. + +Nobody has yet +defined the notch. + +We're defining it now. + +So we can choose the +definition of a notch + +to make the value of +k something simple. + +And the obvious choice for +the simplest real number + +that you could imagine +that's not 0 is 1. + +So we could choose +the definition + +of the notch to +make k equal to 1. + +Except that we can't +change the sign of k. + +The sign of k makes important +differences in this equation. + +And we don't want to make the +definition of a notch negative + +or imaginary, I +guess, is what you + +need to change the sign of k. + +So as long as +notches are real, we + +can only change positive k's +to different positive k's + +and negative k's to different +values of negative k. + +So the convention would be +that when k is not equal to 0-- + +it can be 0 as a special case. + +But when k is not equal +to 0, define the notch + +so that k is equal +to plus or minus 1. + +I would say that +this convention is + +more common than that +convention of the books + +that I've read in my +lifetime, but both conventions + +are in use. + +And one sees from this +dimensional relationship + +that one can certainly +choose a notch + +to make k if it's nonzero +have any value you + +want of the same sign. + +And that means you can +always make k plus or minus + +1 if it's not 0. + +The books that use this as their +convention, generally speaking, + +leave the notch undefined +when k equals 0. + +Undefined means arbitrary. + +And there's no problem with +that because k and the notch + +never really appear in +final physical quantities. + +The notch always +was just your choice + +of how to write down your +co-moving map of what + +the universe looks like. + +OK, any questions about these +funny issues involving units? + +OK, good. + +The next thing I +want to do now is + +to start talking about +solutions to this equation. + +And I guess I'll leave the +equation there and start + +on the new blackboard. + +OK, I'm going to rewrite +the equation almost the way + +it was written on the top there. + +In fact, exactly as it +was written on top there. + +I'm going to +rewrite the equation + +as E equals 1/2 a dot squared +minus 4 pi over 3 G rho sub i + +over a. + +And the reason I'm writing it +in this way rather than any + +of the other six or seven +ways that we've written it, + +is that this way the only +time-varying thing is a itself. + +And if we want to talk +about what the differential + +equation tells us about +the time variation of a, + +it helps a lot if we're writing +an equation where a of t + +is the only thing +that varies with time. + +And this is at least +one way of doing that. + +So in particular, I used +rho sub i rather than rho. + +So the behavior of this +equation might very well + +depend on the sign of E. +And we'll see that it does. + +And if we think it might +depend on the sign of E, + +we realize from the +beginning that E + +could be positive, +negative, or 0. + +There are those three cases. + +So those are the cases +we want to look at. + +E can be positive, +negative, or 0. + +So we'll take them +one at a time. + +It will help to make things +completely obvious to rewrite + +this as an equation +for a dot squared. + +I'll multiply by 2. + +And write this as +equation a dot squared + +is equal to 2E plus 8 pi +over 3 G rho sub i over a. + +8 pi instead of 4 pi +because we multiplied by 2. + +And we notice that this term, +proportional to rho sub i + +over a, is +unambiguously positive. + +We're not going to have +any negative mass densities + +in our problem. + +There's no way that can happen. + +And a is always positive. + +So the right term is positive. + +a dot squared had +better be positive + +because it's the +square of something. + +E could, in principle, +have either sign. + +And we'll talk about both +cases, or the 0 case. + +But if we start with the +case where E is positive, + +just to consider these +three cases one at a time. + +So suppose E is greater than 0. + +And remind you that E +and k had opposite signs. + +So that would imply +that k was negative. + +So if we start by considering +the k negative case or the E + +positive case, then we see that +we have a positive number here + +and a positive number there. + +So they will add up to always +give us a positive number. + +a dot squared will +always be positive. + +And it will just mean that +a dot will be positive. + +Square root of a positive +number is a positive number. + +At least it's only the positive +square root that matters here. + +So a will just keep growing +forever in this case. + +a dot squared will +never fall below 2E. + +So it will be a lower +bound to a dot squared. + +And that means there will +always be a minimum expansion + +rate that the +universe will have. + +So in this case, a +increases forever. + +And that's called +an open universe. + +And it's one of the +three possibilities + +that we're going to +be investigating here. + +Next case is E +less than 0, which + +is the more common notation of +k means k is greater than 0. + +In this case, if you think of +E as an energy, which it really + +is, it means we have +less than 0 energy. + +Which means that we basically +have a bound system. + +And the equation tells us that +it acts like a bound system. + +We don't have to rely +on that intuition, + +but that is the right intuition. + +The equation up there tells +us that if E is negative, + +the total right-hand side +had better be positive + +because the left-hand side is +positive and the left-hand side + +cannot go negative. + +But this term is going to +get smaller and smaller + +as a increases. + +And as this term gets +smaller and smaller, + +it runs the risk of no +longer outweighing this term + +and giving possibly +a negative answer. + +And what has to happen is a +cannot get any bigger than + +the value it would have where +the right-hand side would + +vanish. + +So a continues to grow +because a dot is positive. + +This gets smaller and +smaller until this term + +equals that term in magnitude. + +And then, a dot goes to 0. + +What happens next +is not completely + +obvious from this +equation, but it + +means that we have an +expanding universe that's + +reached a maximum +size and then stopped. + +Then, what is actually +obvious is from this equation + +is that it will +start to collapse. + +So this case corresponds +to a universe that + +reaches a maximum size and then +turns around and collapses. + +So a has a maximum value. + +And we can read off +from that equation what + +it is, a max is +just the value that + +makes the right-hand +side of that equation 0, + +which is minus 4 pi G +rho sub i divided by 3E. + +And remember, E is +negative for this case, + +so this is a positive number. + +So a has some positive +maximum value. + +Reaches that value, and then +turns around and collapses. + +Yes? + +AUDIENCE: Sorry, I don't know +if you said this already, + +but since a dot squared is +equal to some quantity, when you + +solve for a dot, you can have +positive and negative solution. + +Why do we discount +the negative solution? + +PROFESSOR: OK, +very good question. + +The question if +you didn't hear it + +is, why do we discount +the negative solution + +when we have an equation +for a dot squared? + +Couldn't a dot be +positive or negative? + +And the answer is it +certainly could be either. + +And both solutions +exist as valid solutions + +to these equations. + +But we started out with +an initial condition + +that a dot was positive. + +Our initial value +of a dot was H i. + +And once it's positive, +it can't change sign + +according to that equation. + +Except by going +through 0, which is + +what we're talking about now. + +But it will only change +sign when it goes through 0. + +So it reaches a maximum +value, then it does collapse. + +And in the collapsing +phase, that same equation, + +a dot squared equals +the right-hand side, + +holds where it would be +the negative solution that + +describes the collapsing phase. + +So the verbal description +of what's happening here + +is that the universe +reaches a maximum size + +and then collapses. + +And it collapses all the way +to a equals 0 in this model. + +And that's often +called the Big Crunch + +for lack of a better word. + +The Big Crunch being +the collapsing form that + +corresponds to the +Big Bang, which + +is the instant which +all this starts. + +And this was called +an open universe. + +As you could +probably guess, this + +is called a closed universe. + +OK. + +And now finally, we want +to consider a case where + +E is not positive +and not negative. + +The case that we're +left with is E equals 0. + +And that's called +the critical case. + +So the critical value +for E is E is equal to 0. + +And that means that k +is equal to 0 as well. + +It implies k equals 0. + +And notice that this +is a special case. + +E is a real number. + +It can be positive, +negative, and 0 is just + +a particular value on the +borderline between those two. + +For the people who are in the +habit of rescaling notches + +so that k is always +plus 1, minus 1, or 0, + +it makes it sound like there are +three totally distinct cases. + +But that's only because +of the rescaling + +that those people are doing. + +If you keep track of E as your +variable, which you certainly + +can, you do see that +the flat case, E equals + +0-- the critical +case-- is really + +just the borderline +of the other two. + +And it's therefore, arbitrarily +close to both of the other two. + +It really is where they meet. + +But working out the equations, +we have in this case + +a dot over a squared is +equal to 8 pi over 3 G rho. + +And in general, it's minus +kc squared over a squared. + +But we're now considering +the case where that vanishes. + +And that means we +have a unique value + +for rho in terms +of a dot over a. + +And at this point, it's +worth reminding ourselves + +that a dot over a is just +H. So this is H squared. + +So for this critical +case, the case + +that's just on the borderline +between being open and closed-- + +and we'll be calling it flat. + +For this critical case, we +have a definite relationship + +between rho and H. +So rho has to equal + +what we call the +critical density, which + +you get by just +solving that equation. + +And it's 3H squared over 8 pi G. + +And we see, therefore, that +rho being equal to rho c + +is this dividing line +between open and closed. + +And if you think back about +the signs of what we had, + +what you'll see is +that rho bigger rho + +c is what corresponds +to a closed universe. + +Rho less than rho c +is what corresponds + +to an open universe. + +And rho equals rho +c can be called + +either a critical +universe or we'll + +be calling it a flat universe. + +And the meaning of the word +"flat" will be motivated later. + +For now, these words-- +open, closed, and flat-- + +refer to the time +evolution of the universe. + +We'll see later that +it's also connected + +to the geometry of the universe, +but we're not there yet. + +Then the word "flat" +will make some sense. + +Yes. + +AUDIENCE: How do we know there's +not some very large entity, + +like some cluster of +black holes or something + +that renders all of this not +applicable to our universe? + +PROFESSOR: OK. + +The question is, how +do we know there's not + +some humongous perturbation, +some huge collection + +of black holes that +renders this all + +inapplicable to our universe? + +The answer is that it +works for our universe. + +That is, observationally +we can test these things + +in a number of ways. + +Tests include calculations +of the production + +of the light chemical +elements in the Big Bang. + +Tests include making predictions +for what the cosmic background + +radiation should +look like in detail. + +And those tests work +extraordinarily well. + +So that's why we +believe the picture. + +But you're right, +we don't have really + +direct confirmation +of most of this. + +And if there was some +giant conglomeration + +of mass out there someplace, it +might not have been found yet. + +But so far, this +picture works very well. + +That's all I can say. + +And there really is +quite a bit of evidence. + +We'll maybe talk +more about it later. + +Any other questions? + +OK. + +So having understood +the importance + +of this critical +density, it might + +be nice to know what the +value for the critical density + +for our universe is. + +And we can calculate it because +it just depends on the Hubble + +expansion rate, an the +Hubble expansion rate + +has been measured. + +So if we try to put +in numbers, it's + +useful to write the present +value of the Hubble expansion + +rate, as it's often +written, as 100 times h sub + +0 kilometers per +second per megaparsec. + +So this defines h sub +0, little h sub 0. + +And I think the main advantage +of using this notation + +is that you don't have to keep +writing kilometers per second + +per megaparsec which gets to +be a real pain to keep writing. + +So little h sub 0 is just +a dimensionless number + +that defines the +Hubble expansion rate. + +And it does then allow you +to write other formulas + +in simple ways. + +Numerically, Newton's +constant you can look up. + +It's 6.672 times +10 to the minus 8 + +centimeter cubed per +gram per second squared. + +And when you put these equations +together, all you need to know + +is G and H squared to +know what rho critical is. + +You find that rho critical can +be written initially for any H0 + +as 1.88 h0 squared +coming from the h squared + +in the original formula times +10 to the minus 29 grams + +per centimeter cubed. + +And note the whopping smallness +of that 10 to the minus 29. + +The mass density of +our universe is, as far + +as we know, equal to +this critical density. + +We know it's equal to +within about a half + +of a percent or so. + +And h0 is near 1. + +h0, according to +Planck, is 0.67-- + +according to the +Planck satellite + +measurement of the +Hubble parameter + +And if you put +that into here, you + +get the critical density +is about 8.4 times 10 + +to the minus 30 grams +per centimeter cubed. + +And that is equivalent to about +5 protons per cubic meter. + +So I've written +the answer in terms + +of grams per cubic +centimeter because + +to me that's a very +natural unit for density + +because it's the +density of water. + +We're saying that the average +density of the universe is only + +about 10 to the minus +29 quantity 8.410. + +The average density of the +universe is only about 10 + +to the minus 29 times +the density of water. + +So it's an unbelievably empty +universe that we're living in. + +It's hard to believe the +universe is that empty, + +but there are large spaces +between the galaxies + +that we look at. + +So the universe is +incredibly empty. + +And in fact, this is a +vastly better vacuum. + +An average part of the universe +is a vastly better vacuum + +than can be made on +Earth by any machinery + +that we have access to. + +So the best vacuum is empty +space, just middle of nowhere. + +And it's vastly better +than what we can actually + +produce on Earth. + +Yes. + +AUDIENCE: I see you +used protons here, + +5 protons per cubic medium. + +So is this density corresponding +to density of baryonic matter, + +or all types of matter? + +PROFESSOR: This is actually +all types of matters, + +even though I'm using my +proton as a meter stick. + +But it is the total mass +density of the universe that's + +very close to the +critical value. + +And I was just about +to say something + +about what the total +mass is made up of. + +Cosmologists define-- this +was certainly mentioned + +in my first lecture-- a +Greek letter capital Omega + +to mean the actual mass +density of the universe divided + +by this critical density. + +So omega equals 1 in +this language corresponds + +to a flat universe at +this critical point. + +Omega bigger than 1 corresponds +to a closed universe. + +And omega less +than 1 corresponds + +to an open universe. + +And today, we know that +omega is equal to 1 + +to an accuracy of about +a half of a percent. + +To a very good accuracy we +know omega is very close to 1. + +It's made up of +different contributions. + +And these tend to vary with +time-- as the best measurements + +tend to vary with +time by a few percent. + +But omega matter-- and +here I mean visible + +plus dark matter-- +is roughly about 0.3. + +And most of the universe +today, as we mentioned earlier, + +the universe today is pretty +much dark energy-dominated. + +So omega dark energy +is about equal to 0.70. + +And omega total is +pretty close to 1. + +Plus or minus about +a half of a percent. + +So one of the +implications here is + +that we've been assuming +in our calculation so far + +that we're talking about nothing +but non-relativistic matter. + +That's actually only about +30% of the actual matter + +in the current universe. + +So I did say this +is the beginning. + +The current universe today +does not obey the equations + +that we've written +down very accurately. + +It's pretty far off. + +But the equations +that we wrote down + +are pretty accurate +for the history + +of our universe from a +period of about 50,000 years + +after the Big Bang up +to about 9 billion years + +after the Big Bang. + +Yes. + +AUDIENCE: Before dark +energy was discovered, + +did they think omega +was [INAUDIBLE]? + +PROFESSOR: Yes. + +At least many people did. + +Before dark energy +was discovered, + +there was a controversy +in the community + +over what we thought omega was. + +Those of us who had +faith in inflation + +believed that omega +would be 1 because that's + +what inflation predicts. + +Astronomers who just had +faith in observations + +believed that omega +was 0.2 or 0.3 + +because that's what they saw. + +And the truth ended +up being somewhat + +in between in the +sense that omega + +total we now all agree +is very close to 1 + +as inflation predicts. + +But it's still true that the +stuff that the astronomers saw + +at this earlier time did +only add up to 0.2 or 0.3. + +So they correctly estimated +what they were looking at + +and they had no way of +knowing that there was also + +this dark energy component +until it was finally + +discovered in 1998. + +Yes. + +AUDIENCE: If we don't know what +dark energy is, observationally + +how have we been +able to measure that? + +PROFESSOR: How do we +measure it so accurately + +if we don't know +what it is, right? + +Right. + +Well, the answer +is while we're not + +sure what it is, we +actually do think + +we know a lot of its properties. + +And essentially, almost +all properties that + +are relevant to cosmology. + +We just don't know what's +sort of like inside. + +So we know it creates +repulsive gravity. + +We know how much repulsive +gravity it creates. + +And we also know to +reasonable accuracy + +how the dark energy +has been evolving + +with time, which is +really that it's not + +been evolving with time. + +And that determines +what its pressure is. + +It determines, in +fact-- to not evolve + +with time we'll see later +requires the pressure + +to be equal to the negative +of the energy density. + +Pressure is related to how +energies change with time, as I + +mentioned a few minutes +ago in a different context. + +If you have a box that expands +and there's a pressure, + +the pressure does dp +dv work on the box. + +And you can tell how much +the energy in the box + +should change for +a given pressure. + +And we'll do this +more carefully later, + +but to have the energy +not change at all + +requires a pressure, which +is the negative of the energy + +density. + +So we know how much acceleration +the dark energy causes. + +We know to reasonable +accuracy and we + +assume it's true +that the pressure is + +equal to minus the +energy density. + +And that's all you need to know +to calculate how much of it + +you need to account for +that much acceleration. + +And that's how it's done. + +Any other questions? + +OK next thing we want to +do is to actually solve + +this equation for +the easiest case. + +We'll solve it in general +later, but the easiest case + +to solve it is the case +of the critical case. + +We only have a few +minutes, but it only + +takes a few minutes to solve +the equation for this case. + +It should be over here. + +So for the critical case, +it's the case E is equal to 0. + +And therefore, we +just have a dot + +squared is equal to a +constant divided by a. + +And it won't really +matter for us + +right now what this constant is. + +So I don't even have +to keep track of it. + +I'll just write it +as const, C-O-N-S-T. + +And I'll take the square +root of this equation + +because it's easier +to know what a dot is + +than to know what a is. + +Easier to make use of +knowing what a dot is. + +So I can rewrite that equation +as a dot, which I'll now + +write as da dt, to be a little +more explicit about what we're + +talking about, is equal to a +constant over a to the 1/2. + +So this now is the k +equals 0 evolution. + +So this is just the +same Friedmann equation + +rewritten for the +special case k equals 0. + +And now I'm just +going to perform + +the amazingly complicated +manipulation of multiplying + +both sides of the +equation by a to the half. + +So we have a to the half. + +I'm also going to +multiply by dt. + +So a to the half da will be +equal to a constant times dt. + +And now we can just +integrate both sides + +as an indefinite integral. + +And integrating both sides +as an indefinite integral, + +the left-hand side +becomes-- go back over here. + +2/3 a to the 3/2 is +equal to a constant times + +t plus an arbitrary other +constant of integration. + +This is the most +general equation, + +which when differentiated +gives you this. + +And now, this +equation can be solved + +to tell us what a is +as a function of t. + +But before I do that, I'm going +to say something about c prime + +here. + +c prime is allowed +by the integration. + +But remember that when we +defined our scale of t, + +we just started at +some arbitrary time, + +ti, which we didn't +even specify. + +So there's no +particular significance + +to the origin of +time in the equations + +that we've written so far. + +So we're perfectly free to +shift the origin of time + +by just redefining our clocks. + +Cosmic time, +remember, is defined + +in a way which makes it +uniform throughout the universe + +by our construction. + +But we haven't said anything yet +about how to start cosmic time. + +But now, we have a +good way to start it. + +In this model, +there is going to be + +a time at which a +is going to go to 0. + +No matter what we +choose for c prime here, + +there will be some t which will +make the right-hand side 0. + +And therefore, a 0. + +And that's the instant +of the Big Bang. + +That's when everything starts. +a never gets smaller than 0. + +So it's very natural +to take that to be + +defined to be the 0 of time. + +So that's what +we're going to do. + +So we're going to define t +equals 0 to be when a of t + +equals 0. + +That's just a +choice of the origin + +of time, which you're +certainly allowed + +to do without contradicting +anything else that we've said. + +And that means we're just +setting c prime equal to 0. + +So that when that's 0, that's 0. + +So this implies +c prime equals 0. + +And that then +implies-- we could take + +the 2/3 power of this equation. + +And I told you we don't really +care what that constant is. + +So therefore, we +don't really care + +about what that constant is. + +What we get is that a is +equal to some constant, + +not necessarily related +to any of the constants + +we've said so far. + +Although, you can +calculate how it is. + +But some constant times +t to the 2/3 power. + +Or equivalently, +you could just write + +a is proportional to +t to the 2/3, which + +has the same content. + +Now, you might think +you'd want to know + +what the constant of +proportionality is. + +But remember, the constant +of proportionality + +just depends on the +definition of the notch. + +If you want to define the +notch so that a is equal to 1 + +today, then you would +care what the constant is. + +If you're willing to just leave +the definition of the notch + +arbitrary, then you don't +care what the constant is. + +And that's the case that +I'll be doing, actually. + +I will not define +a to be 1 today. + +The definition of the +notch is just arbitrary + +as far as the equations +that I'll be writing. + +And therefore, it will +be sufficient to know + +that a is just proportional +to t to the 2/3 + +for the flat universe case, +for the critical density case. + +And that's where +we'll stop today. + +And this actually pretty +really covers everything + +through lecture notes three, +which is the same material that + +will be covered on +the quiz next week. + +[INAUDIBLE] does not +seem to have shown up, + +but we'll assume that probably +the review session will + +be next Monday night at 7:30. + +I will check it out and +get back to you by email. \ No newline at end of file diff --git a/mJ54DfN95Zo.txt b/mJ54DfN95Zo.txt new file mode 100644 index 0000000000000000000000000000000000000000..d5e6f1602a8a4c1d233f67174ca27e3875037fa2 --- /dev/null +++ b/mJ54DfN95Zo.txt @@ -0,0 +1,9411 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT OpenCourseWare continue to + + align:start position:0% +will help MIT OpenCourseWare continue to + + + align:start position:0% +will help MIT OpenCourseWare continue to +offer high quality educational resources + + align:start position:0% +offer high quality educational resources + + + align:start position:0% +offer high quality educational resources +for free + + align:start position:0% +for free + + + align:start position:0% +for free +to make a donation or to view additional + + align:start position:0% +to make a donation or to view additional + + + align:start position:0% +to make a donation or to view additional +materials from hundreds of MIT courses + + align:start position:0% +materials from hundreds of MIT courses + + + align:start position:0% +materials from hundreds of MIT courses +visit MIT opencourseware at ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +okay guys we're actually slightly ahead + + align:start position:0% +okay guys we're actually slightly ahead + + + align:start position:0% +okay guys we're actually slightly ahead +of where I thought we'd be at this point + + align:start position:0% +of where I thought we'd be at this point + + + align:start position:0% +of where I thought we'd be at this point +so I'm only gonna spend about half of + + align:start position:0% +so I'm only gonna spend about half of + + + align:start position:0% +so I'm only gonna spend about half of +today's lecture finishing up some new + + align:start position:0% +today's lecture finishing up some new + + + align:start position:0% +today's lecture finishing up some new +material on mass parabolas and stability + + align:start position:0% +material on mass parabolas and stability + + + align:start position:0% +material on mass parabolas and stability +I also got a comment in through the + + align:start position:0% +I also got a comment in through the + + + align:start position:0% +I also got a comment in through the +anonymous box that said please leave a + + align:start position:0% +anonymous box that said please leave a + + + align:start position:0% +anonymous box that said please leave a +little bit of time after class for + + align:start position:0% +little bit of time after class for + + + align:start position:0% +little bit of time after class for +questions so you can get them out right + + align:start position:0% +questions so you can get them out right + + + align:start position:0% +questions so you can get them out right +away and because I'm usually running off + + align:start position:0% +away and because I'm usually running off + + + align:start position:0% +away and because I'm usually running off +the teach some other class at like the + + align:start position:0% +the teach some other class at like the + + + align:start position:0% +the teach some other class at like the +IDC or some other building so from now + + align:start position:0% +IDC or some other building so from now + + + align:start position:0% +IDC or some other building so from now +on I'll try and leave about five minutes + + align:start position:0% +on I'll try and leave about five minutes + + + align:start position:0% +on I'll try and leave about five minutes +at the end of class for questions on + + align:start position:0% +at the end of class for questions on + + + align:start position:0% +at the end of class for questions on +today's material and we'll make up with + + align:start position:0% +today's material and we'll make up with + + + align:start position:0% +today's material and we'll make up with +it with the second half hour or 25 + + align:start position:0% +it with the second half hour or 25 + + + align:start position:0% +it with the second half hour or 25 +minutes of this class being for all the + + align:start position:0% +minutes of this class being for all the + + + align:start position:0% +minutes of this class being for all the +questions on the material so far in the + + align:start position:0% +questions on the material so far in the + + + align:start position:0% +questions on the material so far in the +first two weeks but first I wanted to + + align:start position:0% +first two weeks but first I wanted to + + + align:start position:0% +first two weeks but first I wanted to +give a quick review of where we were + + align:start position:0% +give a quick review of where we were + + + align:start position:0% +give a quick review of where we were +Wednesday and launch back into math + + align:start position:0% +Wednesday and launch back into math + + + align:start position:0% +Wednesday and launch back into math +parabolas which are ways of looking at + + align:start position:0% +parabolas which are ways of looking at + + + align:start position:0% +parabolas which are ways of looking at +nuclear stability in relative numbers + + align:start position:0% +nuclear stability in relative numbers + + + align:start position:0% +nuclear stability in relative numbers +and even or oddness of nuclei so you saw + + align:start position:0% +and even or oddness of nuclei so you saw + + + align:start position:0% +and even or oddness of nuclei so you saw +last time we intuitively derived the + + align:start position:0% +last time we intuitively derived the + + + align:start position:0% +last time we intuitively derived the +semi empirical mass formula as a sum of + + align:start position:0% +semi empirical mass formula as a sum of + + + align:start position:0% +semi empirical mass formula as a sum of +volume surface Coulomb asymmetry and + + align:start position:0% +volume surface Coulomb asymmetry and + + + align:start position:0% +volume surface Coulomb asymmetry and +pairing or whether things are even even + + align:start position:0% +pairing or whether things are even even + + + align:start position:0% +pairing or whether things are even even +or odd even terms with the coefficients + + align:start position:0% +or odd even terms with the coefficients + + + align:start position:0% +or odd even terms with the coefficients +in MeV gleaned from data and the forms + + align:start position:0% +in MeV gleaned from data and the forms + + + align:start position:0% +in MeV gleaned from data and the forms +of the and the exponents right here + + align:start position:0% +of the and the exponents right here + + + align:start position:0% +of the and the exponents right here +gleaned from intuition here we assume + + align:start position:0% +gleaned from intuition here we assume + + + align:start position:0% +gleaned from intuition here we assume +that the nucleus can be thought of like + + align:start position:0% +that the nucleus can be thought of like + + + align:start position:0% +that the nucleus can be thought of like +a big drop of liquid with some charged + + align:start position:0% +a big drop of liquid with some charged + + + align:start position:0% +a big drop of liquid with some charged +particles in it and so the droplet + + align:start position:0% +particles in it and so the droplet + + + align:start position:0% +particles in it and so the droplet +should become more stable the more + + align:start position:0% +should become more stable the more + + + align:start position:0% +should become more stable the more +nuclei there are or the nor nucleons + + align:start position:0% +nuclei there are or the nor nucleons + + + align:start position:0% +nuclei there are or the nor nucleons +there are but then you have some more + + align:start position:0% +there are but then you have some more + + + align:start position:0% +there are but then you have some more +outside on the surface that aren't + + align:start position:0% +outside on the surface that aren't + + + align:start position:0% +outside on the surface that aren't +bonded to the others all of the protons + + align:start position:0% +bonded to the others all of the protons + + + align:start position:0% +bonded to the others all of the protons +are repelling each other over linear + + align:start position:0% +are repelling each other over linear + + + align:start position:0% +are repelling each other over linear +length scales because the radius of this + + align:start position:0% +length scales because the radius of this + + + align:start position:0% +length scales because the radius of this +liquid drop would scale like a to the + + align:start position:0% +liquid drop would scale like a to the + + + align:start position:0% +liquid drop would scale like a to the +one third there's an asymmetry term + + align:start position:0% +one third there's an asymmetry term + + + align:start position:0% +one third there's an asymmetry term +which means if the neutrons and protons + + align:start position:0% +which means if the neutrons and protons + + + align:start position:0% +which means if the neutrons and protons +are out of balance there's going to be + + align:start position:0% +are out of balance there's going to be + + + align:start position:0% +are out of balance there's going to be +some some less binding energy and then + + align:start position:0% +some some less binding energy and then + + + align:start position:0% +some some less binding energy and then +there's this extra part that tells you + + align:start position:0% +there's this extra part that tells you + + + align:start position:0% +there's this extra part that tells you +whether the nuclei are even even or odd + + align:start position:0% +whether the nuclei are even even or odd + + + align:start position:0% +whether the nuclei are even even or odd +odd and this works pretty well if you + + align:start position:0% +odd and this works pretty well if you + + + align:start position:0% +odd and this works pretty well if you +remember we looked at theory versus + + align:start position:0% +remember we looked at theory versus + + + align:start position:0% +remember we looked at theory versus +experiment where all the red points here + + align:start position:0% +experiment where all the red points here + + + align:start position:0% +experiment where all the red points here +are theoretical predictions and all the + + align:start position:0% +are theoretical predictions and all the + + + align:start position:0% +are theoretical predictions and all the +black points are experimental + + align:start position:0% +black points are experimental + + + align:start position:0% +black points are experimental +predictions and for the most part they + + align:start position:0% +predictions and for the most part they + + + align:start position:0% +predictions and for the most part they +look spot-on it generates the classic + + align:start position:0% +look spot-on it generates the classic + + + align:start position:0% +look spot-on it generates the classic +binding energy per nucleon curve that + + align:start position:0% +binding energy per nucleon curve that + + + align:start position:0% +binding energy per nucleon curve that +you see in the textbook and can predict + + align:start position:0% +you see in the textbook and can predict + + + align:start position:0% +you see in the textbook and can predict +from the semi empirical mass formula + + align:start position:0% +from the semi empirical mass formula + + + align:start position:0% +from the semi empirical mass formula +zooming in and correcting for let's say + + align:start position:0% +zooming in and correcting for let's say + + + align:start position:0% +zooming in and correcting for let's say +just getting absolute values of errors + + align:start position:0% +just getting absolute values of errors + + + align:start position:0% +just getting absolute values of errors +you can see that except for the very + + align:start position:0% +you can see that except for the very + + + align:start position:0% +you can see that except for the very +small nuclei and a few Peaks which we + + align:start position:0% +small nuclei and a few Peaks which we + + + align:start position:0% +small nuclei and a few Peaks which we +explained by looking even closer the + + align:start position:0% +explained by looking even closer the + + + align:start position:0% +explained by looking even closer the +formula well it predicts nuclear + + align:start position:0% +formula well it predicts nuclear + + + align:start position:0% +formula well it predicts nuclear +stability quite well on average again + + align:start position:0% +stability quite well on average again + + + align:start position:0% +stability quite well on average again +this line right here if there's a dot + + align:start position:0% +this line right here if there's a dot + + + align:start position:0% +this line right here if there's a dot +that lies on this blue line it means + + align:start position:0% +that lies on this blue line it means + + + align:start position:0% +that lies on this blue line it means +that theory and experiment agree and a + + align:start position:0% +that theory and experiment agree and a + + + align:start position:0% +that theory and experiment agree and a +deviation by ofyou mev here and they are + + align:start position:0% +deviation by ofyou mev here and they are + + + align:start position:0% +deviation by ofyou mev here and they are +not too bad but we started also looking + + align:start position:0% +not too bad but we started also looking + + + align:start position:0% +not too bad but we started also looking +at different nuclear stability trends + + align:start position:0% +at different nuclear stability trends + + + align:start position:0% +at different nuclear stability trends +and we noticed that for odd mass number + + align:start position:0% +and we noticed that for odd mass number + + + align:start position:0% +and we noticed that for odd mass number +nuclei there is usually only one or + + align:start position:0% +nuclei there is usually only one or + + + align:start position:0% +nuclei there is usually only one or +sometimes none stable isotopes per Z + + align:start position:0% +sometimes none stable isotopes per Z + + + align:start position:0% +sometimes none stable isotopes per Z +whereas for even once there's quite a + + align:start position:0% +whereas for even once there's quite a + + + align:start position:0% +whereas for even once there's quite a +few more and we're going to be now + + align:start position:0% +few more and we're going to be now + + + align:start position:0% +few more and we're going to be now +linking up the stability of nuclei + + align:start position:0% +linking up the stability of nuclei + + + align:start position:0% +linking up the stability of nuclei +versus what mode of decay they will take + + align:start position:0% +versus what mode of decay they will take + + + align:start position:0% +versus what mode of decay they will take +in order to find a more stable + + align:start position:0% +in order to find a more stable + + + align:start position:0% +in order to find a more stable +configuration we looked quickly at the + + align:start position:0% +configuration we looked quickly at the + + + align:start position:0% +configuration we looked quickly at the +number of stable nuclei with even and + + align:start position:0% +number of stable nuclei with even and + + + align:start position:0% +number of stable nuclei with even and +odd Z and noted that this these places + + align:start position:0% +odd Z and noted that this these places + + + align:start position:0% +odd Z and noted that this these places +right here where there are no stable + + align:start position:0% +right here where there are no stable + + + align:start position:0% +right here where there are no stable +nuclei correspond to technetium and + + align:start position:0% +nuclei correspond to technetium and + + + align:start position:0% +nuclei correspond to technetium and +promethium there's no periodic table on + + align:start position:0% +promethium there's no periodic table on + + + align:start position:0% +promethium there's no periodic table on +the back of this wall but behind my back + + align:start position:0% +the back of this wall but behind my back + + + align:start position:0% +the back of this wall but behind my back +on the other wall there's that periodic + + align:start position:0% +on the other wall there's that periodic + + + align:start position:0% +on the other wall there's that periodic +table where you can see the two elements + + align:start position:0% +table where you can see the two elements + + + align:start position:0% +table where you can see the two elements +that are fairly light with no stable + + align:start position:0% +that are fairly light with no stable + + + align:start position:0% +that are fairly light with no stable +isotopes that's what those correspond to + + align:start position:0% +isotopes that's what those correspond to + + + align:start position:0% +isotopes that's what those correspond to +and the peaks correspond to what we call + + align:start position:0% +and the peaks correspond to what we call + + + align:start position:0% +and the peaks correspond to what we call +magic numbers or numbers of protons or + + align:start position:0% +magic numbers or numbers of protons or + + + align:start position:0% +magic numbers or numbers of protons or +neutrons where all available States some + + align:start position:0% +neutrons where all available States some + + + align:start position:0% +neutrons where all available States some +energy are pretty much filled and this + + align:start position:0% +energy are pretty much filled and this + + + align:start position:0% +energy are pretty much filled and this +goes for both protons and neutrons so + + align:start position:0% +goes for both protons and neutrons so + + + align:start position:0% +goes for both protons and neutrons so +something with a magic number for both n + + align:start position:0% +something with a magic number for both n + + + align:start position:0% +something with a magic number for both n +number of neutrons and Z number of + + align:start position:0% +number of neutrons and Z number of + + + align:start position:0% +number of neutrons and Z number of +protons is going to be exceptionally + + align:start position:0% +protons is going to be exceptionally + + + align:start position:0% +protons is going to be exceptionally +stable and we'll see how that's used as + + align:start position:0% +stable and we'll see how that's used as + + + align:start position:0% +stable and we'll see how that's used as +a tool to synthesize the super-heavy + + align:start position:0% +a tool to synthesize the super-heavy + + + align:start position:0% +a tool to synthesize the super-heavy +elements that we believe should exist + + align:start position:0% +elements that we believe should exist + + + align:start position:0% +elements that we believe should exist +and finally we got into these mass + + align:start position:0% +and finally we got into these mass + + + align:start position:0% +and finally we got into these mass +parabolas I found this to be a + + align:start position:0% +parabolas I found this to be a + + + align:start position:0% +parabolas I found this to be a +particularly difficult concept to just + + align:start position:0% +particularly difficult concept to just + + + align:start position:0% +particularly difficult concept to just +get mathematically if you remember we + + align:start position:0% +get mathematically if you remember we + + + align:start position:0% +get mathematically if you remember we +wrote out the semi empirical mass + + align:start position:0% +wrote out the semi empirical mass + + + align:start position:0% +wrote out the semi empirical mass +formula and said if you take the + + align:start position:0% +formula and said if you take the + + + align:start position:0% +formula and said if you take the +derivative with respect to Z as we did + + align:start position:0% +derivative with respect to Z as we did + + + align:start position:0% +derivative with respect to Z as we did +it you would get the most stable z for a + + align:start position:0% +it you would get the most stable z for a + + + align:start position:0% +it you would get the most stable z for a +given a and we started graphing for a + + align:start position:0% +given a and we started graphing for a + + + align:start position:0% +given a and we started graphing for a +equals 93 where naya beum is stable that + + align:start position:0% +equals 93 where naya beum is stable that + + + align:start position:0% +equals 93 where naya beum is stable that +was just the one I had on the brain from + + align:start position:0% +was just the one I had on the brain from + + + align:start position:0% +was just the one I had on the brain from +some failures in lab earlier this week + + align:start position:0% +some failures in lab earlier this week + + + align:start position:0% +some failures in lab earlier this week +we started plotting where those nuclei + + align:start position:0% +we started plotting where those nuclei + + + align:start position:0% +we started plotting where those nuclei +what is at the the relative masses are + + align:start position:0% +what is at the the relative masses are + + + align:start position:0% +what is at the the relative masses are +for a fixed a so let's regenerate + + align:start position:0% +for a fixed a so let's regenerate + + + align:start position:0% +for a fixed a so let's regenerate +that one right now because we were a + + align:start position:0% +that one right now because we were a + + + align:start position:0% +that one right now because we were a +little fast at the end of last lecture + + align:start position:0% +little fast at the end of last lecture + + + align:start position:0% +little fast at the end of last lecture +then I want to generate one for a equals + + align:start position:0% +then I want to generate one for a equals + + + align:start position:0% +then I want to generate one for a equals +40 and you'll see something kind of + + align:start position:0% +40 and you'll see something kind of + + + align:start position:0% +40 and you'll see something kind of +curious I'm going to leave this up here + + align:start position:0% +curious I'm going to leave this up here + + + align:start position:0% +curious I'm going to leave this up here +for a sec if you notice for odd a nuclei + + align:start position:0% +for a sec if you notice for odd a nuclei + + + align:start position:0% +for a sec if you notice for odd a nuclei +there's only one parabola whereas for + + align:start position:0% +there's only one parabola whereas for + + + align:start position:0% +there's only one parabola whereas for +even a there are two why that is we're + + align:start position:0% +even a there are two why that is we're + + + align:start position:0% +even a there are two why that is we're +gonna see when we look at the table of + + align:start position:0% +gonna see when we look at the table of + + + align:start position:0% +gonna see when we look at the table of +nuclides but notice this nucleus right + + align:start position:0% +nuclides but notice this nucleus right + + + align:start position:0% +nuclides but notice this nucleus right +here can decay by either positron + + align:start position:0% +here can decay by either positron + + + align:start position:0% +here can decay by either positron +emission or beta emission to get to a + + align:start position:0% +emission or beta emission to get to a + + + align:start position:0% +emission or beta emission to get to a +more stable form and there are many real + + align:start position:0% +more stable form and there are many real + + + align:start position:0% +more stable form and there are many real +examples and I'm going to show you how + + align:start position:0% +examples and I'm going to show you how + + + align:start position:0% +examples and I'm going to show you how +to find them so let's start off by going + + align:start position:0% +to find them so let's start off by going + + + align:start position:0% +to find them so let's start off by going +back to the table of nuclides finding + + align:start position:0% +back to the table of nuclides finding + + + align:start position:0% +back to the table of nuclides finding +niobium 93 just go up one more chunk and + + align:start position:0% +niobium 93 just go up one more chunk and + + + align:start position:0% +niobium 93 just go up one more chunk and +there we are + + align:start position:0% +there we are + + + align:start position:0% +there we are +Niobe M 93 is a stable isotope and if + + align:start position:0% +Niobe M 93 is a stable isotope and if + + + align:start position:0% +Niobe M 93 is a stable isotope and if +you want to see where it came from you + + align:start position:0% +you want to see where it came from you + + + align:start position:0% +you want to see where it came from you +can scroll down a little bit and see + + align:start position:0% +can scroll down a little bit and see + + + align:start position:0% +can scroll down a little bit and see +it's possible parent nuclides right here + + align:start position:0% +it's possible parent nuclides right here + + + align:start position:0% +it's possible parent nuclides right here +so let's say that niobium will draw + + align:start position:0% +so let's say that niobium will draw + + + align:start position:0% +so let's say that niobium will draw +right there is stable we'll put it at + + align:start position:0% +right there is stable we'll put it at + + + align:start position:0% +right there is stable we'll put it at +the bottom of this parabola and let's + + align:start position:0% +the bottom of this parabola and let's + + + align:start position:0% +the bottom of this parabola and let's +work down in Z so we'll move to + + align:start position:0% +work down in Z so we'll move to + + + align:start position:0% +work down in Z so we'll move to +zirconium zirconium 93 ostensively has a + + align:start position:0% +zirconium zirconium 93 ostensively has a + + + align:start position:0% +zirconium zirconium 93 ostensively has a +very similar atomic mass but if you + + align:start position:0% +very similar atomic mass but if you + + + align:start position:0% +very similar atomic mass but if you +remember that 93 amu is a rather poor + + align:start position:0% +remember that 93 amu is a rather poor + + + align:start position:0% +remember that 93 amu is a rather poor +approximation for the actual mass of all + + align:start position:0% +approximation for the actual mass of all + + + align:start position:0% +approximation for the actual mass of all +nuclei with a equals 93 in fact if you + + align:start position:0% +nuclei with a equals 93 in fact if you + + + align:start position:0% +nuclei with a equals 93 in fact if you +look very closely at the atomic masses + + align:start position:0% +look very closely at the atomic masses + + + align:start position:0% +look very closely at the atomic masses +zirconium 93 is 90 2.90 niobium 93 well + + align:start position:0% +zirconium 93 is 90 2.90 niobium 93 well + + + align:start position:0% +zirconium 93 is 90 2.90 niobium 93 well +it looks like we have to go all the way + + align:start position:0% +it looks like we have to go all the way + + + align:start position:0% +it looks like we have to go all the way +to another digit there 92.9 o6 you have + + align:start position:0% +to another digit there 92.9 o6 you have + + + align:start position:0% +to another digit there 92.9 o6 you have +to go to like even more digits ninety + + align:start position:0% +to go to like even more digits ninety + + + align:start position:0% +to go to like even more digits ninety +two point nine oh six three seventy five + + align:start position:0% +two point nine oh six three seventy five + + + align:start position:0% +two point nine oh six three seventy five +ninety two point nine oh six four + + align:start position:0% +ninety two point nine oh six four + + + align:start position:0% +ninety two point nine oh six four +seventy five so we go down in Z and + + align:start position:0% +seventy five so we go down in Z and + + + align:start position:0% +seventy five so we go down in Z and +we've actually gone up in mass by looks + + align:start position:0% +we've actually gone up in mass by looks + + + align:start position:0% +we've actually gone up in mass by looks +like the sixth or seventh digit in AMU + + align:start position:0% +like the sixth or seventh digit in AMU + + + align:start position:0% +like the sixth or seventh digit in AMU +if we go up in mass we go down in + + align:start position:0% +if we go up in mass we go down in + + + align:start position:0% +if we go up in mass we go down in +binding energy that tells us that + + align:start position:0% +binding energy that tells us that + + + align:start position:0% +binding energy that tells us that +there's something that's less stable and + + align:start position:0% +there's something that's less stable and + + + align:start position:0% +there's something that's less stable and +if you notice we went down by a very + + align:start position:0% +if you notice we went down by a very + + + align:start position:0% +if you notice we went down by a very +smaller or Wien up by a very small + + align:start position:0% +smaller or Wien up by a very small + + + align:start position:0% +smaller or Wien up by a very small +amount of mass notice also that it's + + align:start position:0% +amount of mass notice also that it's + + + align:start position:0% +amount of mass notice also that it's +beta decay energy is really really small + + align:start position:0% +beta decay energy is really really small + + + align:start position:0% +beta decay energy is really really small +ninety one kill electron volts so why + + align:start position:0% +ninety one kill electron volts so why + + + align:start position:0% +ninety one kill electron volts so why +don't we put zirconium + + align:start position:0% +don't we put zirconium + + + align:start position:0% +don't we put zirconium +just above and we note that that decay + + align:start position:0% +just above and we note that that decay + + + align:start position:0% +just above and we note that that decay +will happen by data where the beta let's + + align:start position:0% +will happen by data where the beta let's + + + align:start position:0% +will happen by data where the beta let's +say if we have an isotope with mass + + align:start position:0% +say if we have an isotope with mass + + + align:start position:0% +say if we have an isotope with mass +number a protons Z and let's just call + + align:start position:0% +number a protons Z and let's just call + + + align:start position:0% +number a protons Z and let's just call +it symbol question mark in beta decay we + + align:start position:0% +it symbol question mark in beta decay we + + + align:start position:0% +it symbol question mark in beta decay we +have the same a will have a different Z + + align:start position:0% +have the same a will have a different Z + + + align:start position:0% +have the same a will have a different Z +I'm gonna have to give these symbols + + align:start position:0% +I'm gonna have to give these symbols + + + align:start position:0% +I'm gonna have to give these symbols +let's call this parent and we'll call + + align:start position:0% +let's call this parent and we'll call + + + align:start position:0% +let's call this parent and we'll call +that daughter plus a beta plus an + + align:start position:0% +that daughter plus a beta plus an + + + align:start position:0% +that daughter plus a beta plus an +electron antineutrino and what has to + + align:start position:0% +electron antineutrino and what has to + + + align:start position:0% +electron antineutrino and what has to +happen to that Z in order for everything + + align:start position:0% +happen to that Z in order for everything + + + align:start position:0% +happen to that Z in order for everything +to be conserved it's the same reaction + + align:start position:0% +to be conserved it's the same reaction + + + align:start position:0% +to be conserved it's the same reaction +that we've gone here for I'm sorry for + + align:start position:0% +that we've gone here for I'm sorry for + + + align:start position:0% +that we've gone here for I'm sorry for +their code iam so you'd have to have one + + align:start position:0% +their code iam so you'd have to have one + + + align:start position:0% +their code iam so you'd have to have one +fewer proton to release one electron and + + align:start position:0% +fewer proton to release one electron and + + + align:start position:0% +fewer proton to release one electron and +so that becomes same a but different Z + + align:start position:0% +so that becomes same a but different Z + + + align:start position:0% +so that becomes same a but different Z +and this is the beta decay reaction + + align:start position:0% + + + + align:start position:0% + +let's go back a little farther we'll + + align:start position:0% +let's go back a little farther we'll + + + align:start position:0% +let's go back a little farther we'll +look at the possible parent nuclide for + + align:start position:0% +look at the possible parent nuclide for + + + align:start position:0% +look at the possible parent nuclide for +anyone have a question + + align:start position:0% + + + + align:start position:0% + +let's see which direction are we going + + align:start position:0% +let's see which direction are we going + + + align:start position:0% +let's see which direction are we going +in Z here that goes to yet trium + + align:start position:0% +in Z here that goes to yet trium + + + align:start position:0% +in Z here that goes to yet trium +actually looks like it's going down oh + + align:start position:0% +actually looks like it's going down oh + + + align:start position:0% +actually looks like it's going down oh +yeah for beta decay I'm thinking I have + + align:start position:0% +yeah for beta decay I'm thinking I have + + + align:start position:0% +yeah for beta decay I'm thinking I have +the reaction backwards sorry + + align:start position:0% +the reaction backwards sorry + + + align:start position:0% +the reaction backwards sorry +need one more proton to account for the + + align:start position:0% +need one more proton to account for the + + + align:start position:0% +need one more proton to account for the +extra negative charge you're right okay + + align:start position:0% +extra negative charge you're right okay + + + align:start position:0% +extra negative charge you're right okay +yep I was thinking backwards because + + align:start position:0% +yep I was thinking backwards because + + + align:start position:0% +yep I was thinking backwards because +we're now climbing up the decay chain in + + align:start position:0% +we're now climbing up the decay chain in + + + align:start position:0% +we're now climbing up the decay chain in +reverse order so this could have come + + align:start position:0% +reverse order so this could have come + + + align:start position:0% +reverse order so this could have come +from yttrium 93 with a much higher + + align:start position:0% +from yttrium 93 with a much higher + + + align:start position:0% +from yttrium 93 with a much higher +energy of three MeV so let's put it reom + + align:start position:0% +energy of three MeV so let's put it reom + + + align:start position:0% +energy of three MeV so let's put it reom +right here that gives a beta decay and + + align:start position:0% +right here that gives a beta decay and + + + align:start position:0% +right here that gives a beta decay and +we'll just go one more back to strontium + + align:start position:0% +we'll just go one more back to strontium + + + align:start position:0% +we'll just go one more back to strontium +93 has an even higher beta decay energy + + align:start position:0% +93 has an even higher beta decay energy + + + align:start position:0% +93 has an even higher beta decay energy +so let's put that up here and let's take + + align:start position:0% +so let's put that up here and let's take + + + align:start position:0% +so let's put that up here and let's take +a look at its mass real quick the mass + + align:start position:0% +a look at its mass real quick the mass + + + align:start position:0% +a look at its mass real quick the mass +of strontium 93 92 point nine one four + + align:start position:0% +of strontium 93 92 point nine one four + + + align:start position:0% +of strontium 93 92 point nine one four +AMU if we go back to niobium 93 now it's + + align:start position:0% +AMU if we go back to niobium 93 now it's + + + align:start position:0% +AMU if we go back to niobium 93 now it's +noticeably different different to like + + align:start position:0% +noticeably different different to like + + + align:start position:0% +noticeably different different to like +four significant digits instead of six + + align:start position:0% +four significant digits instead of six + + + align:start position:0% +four significant digits instead of six +ninety two point nine one four versus + + align:start position:0% +ninety two point nine one four versus + + + align:start position:0% +ninety two point nine one four versus +ninety two point nine oh six and so that + + align:start position:0% +ninety two point nine oh six and so that + + + align:start position:0% +ninety two point nine oh six and so that +shows you that a tiny bit of mass and + + align:start position:0% +shows you that a tiny bit of mass and + + + align:start position:0% +shows you that a tiny bit of mass and +AMU corresponds to a pretty significant + + align:start position:0% +AMU corresponds to a pretty significant + + + align:start position:0% +AMU corresponds to a pretty significant +change in binding energy by that same + + align:start position:0% +change in binding energy by that same + + + align:start position:0% +change in binding energy by that same +conversion factor that we've been using + + align:start position:0% +conversion factor that we've been using + + + align:start position:0% +conversion factor that we've been using +everywhere nine thirty one point four + + align:start position:0% +everywhere nine thirty one point four + + + align:start position:0% +everywhere nine thirty one point four +nine + + align:start position:0% +nine + + + align:start position:0% +nine +AMU per big MeV + + align:start position:0% +AMU per big MeV + + + align:start position:0% +AMU per big MeV +yeah per C squared + + align:start position:0% +yeah per C squared + + + align:start position:0% +yeah per C squared +let's see yeah okay + + align:start position:0% +let's see yeah okay + + + align:start position:0% +let's see yeah okay +so let's go now in the other direction + + align:start position:0% +so let's go now in the other direction + + + align:start position:0% +so let's go now in the other direction +in the positron direction niobium can + + align:start position:0% +in the positron direction niobium can + + + align:start position:0% +in the positron direction niobium can +also be made by electron capture from + + align:start position:0% +also be made by electron capture from + + + align:start position:0% +also be made by electron capture from +molybdenum so let's put molybdenum right + + align:start position:0% +molybdenum so let's put molybdenum right + + + align:start position:0% +molybdenum so let's put molybdenum right +here let's say that around half an Emmy + + align:start position:0% +here let's say that around half an Emmy + + + align:start position:0% +here let's say that around half an Emmy +or what do we have here who was like + + align:start position:0% +or what do we have here who was like + + + align:start position:0% +or what do we have here who was like +half an MeV like that + + align:start position:0% +half an MeV like that + + + align:start position:0% +half an MeV like that +and let's see molybdenum 93 could have + + align:start position:0% +and let's see molybdenum 93 could have + + + align:start position:0% +and let's see molybdenum 93 could have +been made by electron capture from + + align:start position:0% +been made by electron capture from + + + align:start position:0% +been made by electron capture from +technetium 93 with an energy of three + + align:start position:0% +technetium 93 with an energy of three + + + align:start position:0% +technetium 93 with an energy of three +point two oh one MeV even more extreme + + align:start position:0% + + + + align:start position:0% + +and we'll go back one more because + + align:start position:0% +and we'll go back one more because + + + align:start position:0% +and we'll go back one more because +there's a trend that I want you guys to + + align:start position:0% +there's a trend that I want you guys to + + + align:start position:0% +there's a trend that I want you guys to +be able to see and this could have come + + align:start position:0% +be able to see and this could have come + + + align:start position:0% +be able to see and this could have come +from electron capture from ruthenium I + + align:start position:0% +from electron capture from ruthenium I + + + align:start position:0% +from electron capture from ruthenium I +think I may have said rubidium last time + + align:start position:0% +think I may have said rubidium last time + + + align:start position:0% +think I may have said rubidium last time +but are you is ruthenium 93 and that 6.3 + + align:start position:0% +but are you is ruthenium 93 and that 6.3 + + + align:start position:0% +but are you is ruthenium 93 and that 6.3 +MeV something like that and this is + + align:start position:0% +MeV something like that and this is + + + align:start position:0% +MeV something like that and this is +where we got to yesterday now I'd like + + align:start position:0% +where we got to yesterday now I'd like + + + align:start position:0% +where we got to yesterday now I'd like +us to take a closer look at the decay + + align:start position:0% +us to take a closer look at the decay + + + align:start position:0% +us to take a closer look at the decay +diagrams which tells us what possible + + align:start position:0% +diagrams which tells us what possible + + + align:start position:0% +diagrams which tells us what possible +decay reactions can happen in each of + + align:start position:0% +decay reactions can happen in each of + + + align:start position:0% +decay reactions can happen in each of +these reactions + + align:start position:0% +these reactions + + + align:start position:0% +these reactions +so let's since we're right here on the + + align:start position:0% +so let's since we're right here on the + + + align:start position:0% +so let's since we're right here on the +chart let's take a look at ruthenium + + align:start position:0% +chart let's take a look at ruthenium + + + align:start position:0% +chart let's take a look at ruthenium +turning into technetium by what it says + + align:start position:0% +turning into technetium by what it says + + + align:start position:0% +turning into technetium by what it says +electron capture so note that on the + + align:start position:0% +electron capture so note that on the + + + align:start position:0% +electron capture so note that on the +table you can click on electron capture + + align:start position:0% +table you can click on electron capture + + + align:start position:0% +table you can click on electron capture +and if it's highlighted then the decay + + align:start position:0% +and if it's highlighted then the decay + + + align:start position:0% +and if it's highlighted then the decay +diagrams are known it's not known for + + align:start position:0% +diagrams are known it's not known for + + + align:start position:0% +diagrams are known it's not known for +every isotope but for a lot of the ones + + align:start position:0% +every isotope but for a lot of the ones + + + align:start position:0% +every isotope but for a lot of the ones +you'll be dealing with it is and you get + + align:start position:0% +you'll be dealing with it is and you get + + + align:start position:0% +you'll be dealing with it is and you get +something I have to zoom out for a lot a + + align:start position:0% +something I have to zoom out for a lot a + + + align:start position:0% +something I have to zoom out for a lot a +lot of different decays what I want you + + align:start position:0% +lot of different decays what I want you + + + align:start position:0% +lot of different decays what I want you +to look at is this one here on the + + align:start position:0% +to look at is this one here on the + + + align:start position:0% +to look at is this one here on the +bottom that I'll zoom into that should + + align:start position:0% +bottom that I'll zoom into that should + + + align:start position:0% +bottom that I'll zoom into that should +be a little more visible so notice that + + align:start position:0% +be a little more visible so notice that + + + align:start position:0% +be a little more visible so notice that +if you want to go down the entire 6.4 + + align:start position:0% +if you want to go down the entire 6.4 + + + align:start position:0% +if you want to go down the entire 6.4 +something MeV it usually proceeds by B+ + + align:start position:0% +something MeV it usually proceeds by B+ + + + align:start position:0% +something MeV it usually proceeds by B+ +or positron decay by either method and + + align:start position:0% +or positron decay by either method and + + + align:start position:0% +or positron decay by either method and +as you go up the chain as these energy + + align:start position:0% +as you go up the chain as these energy + + + align:start position:0% +as you go up the chain as these energy +differences get smaller look what + + align:start position:0% +differences get smaller look what + + + align:start position:0% +differences get smaller look what +happens to the probability of getting + + align:start position:0% +happens to the probability of getting + + + align:start position:0% +happens to the probability of getting +positron decay it shrinks lower and + + align:start position:0% +positron decay it shrinks lower and + + + align:start position:0% +positron decay it shrinks lower and +lower and lower so they + + align:start position:0% +lower and lower so they + + + align:start position:0% +lower and lower so they +a trend that the larger the decay energy + + align:start position:0% +a trend that the larger the decay energy + + + align:start position:0% +a trend that the larger the decay energy +for this type of reaction the more + + align:start position:0% +for this type of reaction the more + + + align:start position:0% +for this type of reaction the more +likely you're going to get positron + + align:start position:0% +likely you're going to get positron + + + align:start position:0% +likely you're going to get positron +decay and in fact where we left off last + + align:start position:0% +decay and in fact where we left off last + + + align:start position:0% +decay and in fact where we left off last +time is in order to get positron decay + + align:start position:0% +time is in order to get positron decay + + + align:start position:0% +time is in order to get positron decay +the Q value of the reaction has to be at + + align:start position:0% +the Q value of the reaction has to be at + + + align:start position:0% +the Q value of the reaction has to be at +least 1.0 to 2 MeV better known as at + + align:start position:0% +least 1.0 to 2 MeV better known as at + + + align:start position:0% +least 1.0 to 2 MeV better known as at +least two times the rest mass of the + + align:start position:0% +least two times the rest mass of the + + + align:start position:0% +least two times the rest mass of the +electron because in this case to + + align:start position:0% +electron because in this case to + + + align:start position:0% +electron because in this case to +conserve charge and energy you shoot out + + align:start position:0% +conserve charge and energy you shoot out + + + align:start position:0% +conserve charge and energy you shoot out +a positron and you also have to inject + + align:start position:0% +a positron and you also have to inject + + + align:start position:0% +a positron and you also have to inject +an electron in order to conserve all the + + align:start position:0% +an electron in order to conserve all the + + + align:start position:0% +an electron in order to conserve all the +charge going on here so there you have + + align:start position:0% +charge going on here so there you have + + + align:start position:0% +charge going on here so there you have +it now let's look at the lower energy + + align:start position:0% +it now let's look at the lower energy + + + align:start position:0% +it now let's look at the lower energy +decay of technetium to molybdenum which + + align:start position:0% +decay of technetium to molybdenum which + + + align:start position:0% +decay of technetium to molybdenum which +had something like 3 MeV associated with + + align:start position:0% +had something like 3 MeV associated with + + + align:start position:0% +had something like 3 MeV associated with +it so we'll click on technetium and its + + align:start position:0% +it so we'll click on technetium and its + + + align:start position:0% +it so we'll click on technetium and its +energy is 3.2 MeV let's take a look at + + align:start position:0% +energy is 3.2 MeV let's take a look at + + + align:start position:0% +energy is 3.2 MeV let's take a look at +its electron capture significantly + + align:start position:0% +its electron capture significantly + + + align:start position:0% +its electron capture significantly +simpler already what do you notice about + + align:start position:0% +simpler already what do you notice about + + + align:start position:0% +simpler already what do you notice about +these positron to electron capture + + align:start position:0% +these positron to electron capture + + + align:start position:0% +these positron to electron capture +ratios anyone call it out indeed when + + align:start position:0% +ratios anyone call it out indeed when + + + align:start position:0% +ratios anyone call it out indeed when +the energy of the decay goes down notice + + align:start position:0% +the energy of the decay goes down notice + + + align:start position:0% +the energy of the decay goes down notice +that only these decays are allowed the + + align:start position:0% +that only these decays are allowed the + + + align:start position:0% +that only these decays are allowed the +electron capture suddenly becomes much + + align:start position:0% +electron capture suddenly becomes much + + + align:start position:0% +electron capture suddenly becomes much +more likely but notice that it does not + + align:start position:0% +more likely but notice that it does not + + + align:start position:0% +more likely but notice that it does not +let you go directly from 3.2 mu v to 0 + + align:start position:0% +let you go directly from 3.2 mu v to 0 + + + align:start position:0% +let you go directly from 3.2 mu v to 0 +there's no allowable decay here so this + + align:start position:0% +there's no allowable decay here so this + + + align:start position:0% +there's no allowable decay here so this +is probably a change of that's 3.2 + + align:start position:0% +is probably a change of that's 3.2 + + + align:start position:0% +is probably a change of that's 3.2 +that's 1.3 a little less than 2 MeV all + + align:start position:0% +that's 1.3 a little less than 2 MeV all + + + align:start position:0% +that's 1.3 a little less than 2 MeV all +of a sudden electron capture becomes + + align:start position:0% +of a sudden electron capture becomes + + + align:start position:0% +of a sudden electron capture becomes +much more likely but not at positron + + align:start position:0% +much more likely but not at positron + + + align:start position:0% +much more likely but not at positron +decay is not disallowed yet so we can + + align:start position:0% +decay is not disallowed yet so we can + + + align:start position:0% +decay is not disallowed yet so we can +say electron capture or positron decay + + align:start position:0% +say electron capture or positron decay + + + align:start position:0% +say electron capture or positron decay +right there everyone with me so far so + + align:start position:0% +right there everyone with me so far so + + + align:start position:0% +right there everyone with me so far so +let's go to the really low energy one + + align:start position:0% +let's go to the really low energy one + + + align:start position:0% +let's go to the really low energy one +will click on molybdenum 93 and see how + + align:start position:0% +will click on molybdenum 93 and see how + + + align:start position:0% +will click on molybdenum 93 and see how +it decays with an energy of 0.40 5 MeV + + align:start position:0% +it decays with an energy of 0.40 5 MeV + + + align:start position:0% +it decays with an energy of 0.40 5 MeV +to niobium anyone want to guess what's + + align:start position:0% +to niobium anyone want to guess what's + + + align:start position:0% +to niobium anyone want to guess what's +allowed + + align:start position:0% +allowed + + + align:start position:0% +allowed +electron capture only there's not enough + + align:start position:0% +electron capture only there's not enough + + + align:start position:0% +electron capture only there's not enough +energy for positron decay and indeed it + + align:start position:0% +energy for positron decay and indeed it + + + align:start position:0% +energy for positron decay and indeed it +draws funny because there's a metastable + + align:start position:0% +draws funny because there's a metastable + + + align:start position:0% +draws funny because there's a metastable +state but if you go scroll down here + + align:start position:0% +state but if you go scroll down here + + + align:start position:0% +state but if you go scroll down here +there are two pathways allowed both of + + align:start position:0% +there are two pathways allowed both of + + + align:start position:0% +there are two pathways allowed both of +which by electron capture decaying + + align:start position:0% +which by electron capture decaying + + + align:start position:0% +which by electron capture decaying +diagrams quite a bit simpler so we leave + + align:start position:0% +diagrams quite a bit simpler so we leave + + + align:start position:0% +diagrams quite a bit simpler so we leave +this one here by saying it can only + + align:start position:0% +this one here by saying it can only + + + align:start position:0% +this one here by saying it can only +decay by electron capture any questions + + align:start position:0% +decay by electron capture any questions + + + align:start position:0% +decay by electron capture any questions +on the odd a before we move on to the + + align:start position:0% +on the odd a before we move on to the + + + align:start position:0% +on the odd a before we move on to the +even which is a little more interesting + + align:start position:0% + + + + align:start position:0% + +cool okay let's move on to the even case + + align:start position:0% +cool okay let's move on to the even case + + + align:start position:0% +cool okay let's move on to the even case +so for here I'm going to go back to the + + align:start position:0% +so for here I'm going to go back to the + + + align:start position:0% +so for here I'm going to go back to the +overall picture of the table of nuclides + + align:start position:0% +overall picture of the table of nuclides + + + align:start position:0% +overall picture of the table of nuclides +click on around where I think + + align:start position:0% +click on around where I think + + + align:start position:0% +click on around where I think +potassium-40 is looks like I got there + + align:start position:0% +potassium-40 is looks like I got there + + + align:start position:0% +potassium-40 is looks like I got there +and I want to point out one of these + + align:start position:0% +and I want to point out one of these + + + align:start position:0% +and I want to point out one of these +features if you wanted to go under go + + align:start position:0% +features if you wanted to go under go + + + align:start position:0% +features if you wanted to go under go +decay change and maintain the same mass + + align:start position:0% +decay change and maintain the same mass + + + align:start position:0% +decay change and maintain the same mass +number that's diagonally from upper left + + align:start position:0% +number that's diagonally from upper left + + + align:start position:0% +number that's diagonally from upper left +to lower right see how all the isotopes + + align:start position:0% +to lower right see how all the isotopes + + + align:start position:0% +to lower right see how all the isotopes +here have a forty in front of them the + + align:start position:0% +here have a forty in front of them the + + + align:start position:0% +here have a forty in front of them the +really interesting part is as you cross + + align:start position:0% +really interesting part is as you cross + + + align:start position:0% +really interesting part is as you cross +this line you go from stable to unstable + + align:start position:0% +this line you go from stable to unstable + + + align:start position:0% +this line you go from stable to unstable +to stable to unstable again the colors + + align:start position:0% +to stable to unstable again the colors + + + align:start position:0% +to stable to unstable again the colors +here is dark blue represents stable and + + align:start position:0% +here is dark blue represents stable and + + + align:start position:0% +here is dark blue represents stable and +dark gray represents long lifetimes of + + align:start position:0% +dark gray represents long lifetimes of + + + align:start position:0% +dark gray represents long lifetimes of +over a hundred thousand years so this is + + align:start position:0% +over a hundred thousand years so this is + + + align:start position:0% +over a hundred thousand years so this is +one of the reasons you find potassium-40 + + align:start position:0% +one of the reasons you find potassium-40 + + + align:start position:0% +one of the reasons you find potassium-40 +in the environment in fact point oh one + + align:start position:0% +in the environment in fact point oh one + + + align:start position:0% +in the environment in fact point oh one +one percent of all potassium in you and + + align:start position:0% +one percent of all potassium in you and + + + align:start position:0% +one percent of all potassium in you and +everything is potassium-40 + + align:start position:0% +everything is potassium-40 + + + align:start position:0% +everything is potassium-40 +it's what's known as a primordial + + align:start position:0% +it's what's known as a primordial + + + align:start position:0% +it's what's known as a primordial +nuclide it's not stable but it's + + align:start position:0% +nuclide it's not stable but it's + + + align:start position:0% +nuclide it's not stable but it's +half-life is so long that there's still + + align:start position:0% +half-life is so long that there's still + + + align:start position:0% +half-life is so long that there's still +some left since the universe began or + + align:start position:0% +some left since the universe began or + + + align:start position:0% +some left since the universe began or +whatever supernova that formed earth got + + align:start position:0% +whatever supernova that formed earth got + + + align:start position:0% +whatever supernova that formed earth got +accumulated into the earth but notice it + + align:start position:0% +accumulated into the earth but notice it + + + align:start position:0% +accumulated into the earth but notice it +can come from it can decay by a couple + + align:start position:0% +can come from it can decay by a couple + + + align:start position:0% +can come from it can decay by a couple +of different methods so let's pick one + + align:start position:0% +of different methods so let's pick one + + + align:start position:0% +of different methods so let's pick one +of those stable isotopes calcium for T + + align:start position:0% +of those stable isotopes calcium for T + + + align:start position:0% +of those stable isotopes calcium for T +and put that as the bottom of the + + align:start position:0% +and put that as the bottom of the + + + align:start position:0% +and put that as the bottom of the +parabola on this diagram + + align:start position:0% +parabola on this diagram + + + align:start position:0% +parabola on this diagram +so we'll put calcium here and in a + + align:start position:0% +so we'll put calcium here and in a + + + align:start position:0% +so we'll put calcium here and in a +relative sense we'll put a calcium point + + align:start position:0% +relative sense we'll put a calcium point + + + align:start position:0% +relative sense we'll put a calcium point +right there for its total mass and it + + align:start position:0% +right there for its total mass and it + + + align:start position:0% +right there for its total mass and it +could have come from beta decay from + + align:start position:0% +could have come from beta decay from + + + align:start position:0% +could have come from beta decay from +potassium-40 or electron capture from + + align:start position:0% +potassium-40 or electron capture from + + + align:start position:0% +potassium-40 or electron capture from +scandium 4040 + + align:start position:0% +scandium 4040 + + + align:start position:0% +scandium 4040 +it can beta-decay for about a 1.3 MeV so + + align:start position:0% +it can beta-decay for about a 1.3 MeV so + + + align:start position:0% +it can beta-decay for about a 1.3 MeV so +potassium it's right here let's say it + + align:start position:0% +potassium it's right here let's say it + + + align:start position:0% +potassium it's right here let's say it +could beta decay with about 1.3 MeV and + + align:start position:0% +could beta decay with about 1.3 MeV and + + + align:start position:0% +could beta decay with about 1.3 MeV and +we'll trace potassium back a little bit + + align:start position:0% +we'll trace potassium back a little bit + + + align:start position:0% +we'll trace potassium back a little bit +figure out where would it have come from + + align:start position:0% +figure out where would it have come from + + + align:start position:0% +figure out where would it have come from +interesting doesn't tell us okay forget + + align:start position:0% +interesting doesn't tell us okay forget + + + align:start position:0% +interesting doesn't tell us okay forget +that let's trace calcium back and say + + align:start position:0% +that let's trace calcium back and say + + + align:start position:0% +that let's trace calcium back and say +there's scandium 40 and scandium 40 can + + align:start position:0% +there's scandium 40 and scandium 40 can + + + align:start position:0% +there's scandium 40 and scandium 40 can +decay with Wow an enormous 14 point 3 2 + + align:start position:0% +decay with Wow an enormous 14 point 3 2 + + + align:start position:0% +decay with Wow an enormous 14 point 3 2 +MeV let's put that like here anyone want + + align:start position:0% +MeV let's put that like here anyone want + + + align:start position:0% +MeV let's put that like here anyone want +to guess which mode electron capture or + + align:start position:0% +to guess which mode electron capture or + + + align:start position:0% +to guess which mode electron capture or +positrons much more likely probably + + align:start position:0% +positrons much more likely probably + + + align:start position:0% +positrons much more likely probably +positron let's take a look oh boy + + align:start position:0% +positron let's take a look oh boy + + + align:start position:0% +positron let's take a look oh boy +another complicated one but the whole + + align:start position:0% +another complicated one but the whole + + + align:start position:0% +another complicated one but the whole +way down positron positron positron for + + align:start position:0% +way down positron positron positron for + + + align:start position:0% +way down positron positron positron for +all the most likely decays you won't + + align:start position:0% +all the most likely decays you won't + + + align:start position:0% +all the most likely decays you won't +find a drawing too every single line I + + align:start position:0% +find a drawing too every single line I + + + align:start position:0% +find a drawing too every single line I +believe that they know that at some + + align:start position:0% +believe that they know that at some + + + align:start position:0% +believe that they know that at some +point drawing extra lines is futile and + + align:start position:0% +point drawing extra lines is futile and + + + align:start position:0% +point drawing extra lines is futile and +they just all overlap each other so I + + align:start position:0% +they just all overlap each other so I + + + align:start position:0% +they just all overlap each other so I +don't know exactly how the algorithm + + align:start position:0% +don't know exactly how the algorithm + + + align:start position:0% +don't know exactly how the algorithm +works but it does draw up to some number + + align:start position:0% +works but it does draw up to some number + + + align:start position:0% +works but it does draw up to some number +of possible decay chains if you want to + + align:start position:0% +of possible decay chains if you want to + + + align:start position:0% +of possible decay chains if you want to +see every single one they are tabulated + + align:start position:0% +see every single one they are tabulated + + + align:start position:0% +see every single one they are tabulated +in a very very long list down below I'm + + align:start position:0% +in a very very long list down below I'm + + + align:start position:0% +in a very very long list down below I'm +never going to ask you to do something + + align:start position:0% +never going to ask you to do something + + + align:start position:0% +never going to ask you to do something +with all of these because that would be + + align:start position:0% +with all of these because that would be + + + align:start position:0% +with all of these because that would be +insane unless it's a relatively simple + + align:start position:0% +insane unless it's a relatively simple + + + align:start position:0% +insane unless it's a relatively simple +decay like that has two or three + + align:start position:0% +decay like that has two or three + + + align:start position:0% +decay like that has two or three +possibilities and let's see this could + + align:start position:0% +possibilities and let's see this could + + + align:start position:0% +possibilities and let's see this could +have come from electron capture from + + align:start position:0% +have come from electron capture from + + + align:start position:0% +have come from electron capture from +titanium forty with eleven point six + + align:start position:0% +titanium forty with eleven point six + + + align:start position:0% +titanium forty with eleven point six +eight I'm easy Wow okay here + + align:start position:0% + + + + align:start position:0% + +and there's titanium and let's go in the + + align:start position:0% +and there's titanium and let's go in the + + + align:start position:0% +and there's titanium and let's go in the +other direction so I do know that + + align:start position:0% +other direction so I do know that + + + align:start position:0% +other direction so I do know that +potassium-40 + + align:start position:0% +potassium-40 + + + align:start position:0% +potassium-40 +can decay into argon-40 so let's jump + + align:start position:0% +can decay into argon-40 so let's jump + + + align:start position:0% +can decay into argon-40 so let's jump +there argon is a stable isotope too so + + align:start position:0% +there argon is a stable isotope too so + + + align:start position:0% +there argon is a stable isotope too so +potassium-40 can decay into argon-40 by + + align:start position:0% +potassium-40 can decay into argon-40 by + + + align:start position:0% +potassium-40 can decay into argon-40 by +electron capture okay good a more + + align:start position:0% +electron capture okay good a more + + + align:start position:0% +electron capture okay good a more +respectable 1.50 5 MeV is positron decay + + align:start position:0% +respectable 1.50 5 MeV is positron decay + + + align:start position:0% +respectable 1.50 5 MeV is positron decay +allowed yes why is that + + align:start position:0% + + + + align:start position:0% + +/ 1.02 to mev yeah anyone had a question + + align:start position:0% +/ 1.02 to mev yeah anyone had a question + + + align:start position:0% +/ 1.02 to mev yeah anyone had a question +no okay + + align:start position:0% +no okay + + + align:start position:0% +no okay +so we've got kind of a kink in our math + + align:start position:0% +so we've got kind of a kink in our math + + + align:start position:0% +so we've got kind of a kink in our math +parabola yeah that's correct yep so once + + align:start position:0% +parabola yeah that's correct yep so once + + + align:start position:0% +parabola yeah that's correct yep so once +the Q value satisfied it is technically + + align:start position:0% +the Q value satisfied it is technically + + + align:start position:0% +the Q value satisfied it is technically +possible + + align:start position:0% +possible + + + align:start position:0% +possible +but if you had something with the decay + + align:start position:0% +but if you had something with the decay + + + align:start position:0% +but if you had something with the decay +energy of like 1.0 to 3 MeV it would be + + align:start position:0% +energy of like 1.0 to 3 MeV it would be + + + align:start position:0% +energy of like 1.0 to 3 MeV it would be +exceedingly unlikely so in fact we can + + align:start position:0% +exceedingly unlikely so in fact we can + + + align:start position:0% +exceedingly unlikely so in fact we can +take a look at this this is I would say + + align:start position:0% +take a look at this this is I would say + + + align:start position:0% +take a look at this this is I would say +is also going to be on the exceedingly + + align:start position:0% +is also going to be on the exceedingly + + + align:start position:0% +is also going to be on the exceedingly +unlikely level and we can take a look so + + align:start position:0% +unlikely level and we can take a look so + + + align:start position:0% +unlikely level and we can take a look so +if we look at the decay diagram we know + + align:start position:0% +if we look at the decay diagram we know + + + align:start position:0% +if we look at the decay diagram we know +it makes positrons they're not even + + align:start position:0% +it makes positrons they're not even + + + align:start position:0% +it makes positrons they're not even +really listed interesting because so + + align:start position:0% +really listed interesting because so + + + align:start position:0% +really listed interesting because so +that process would not be allowed but + + align:start position:0% +that process would not be allowed but + + + align:start position:0% +that process would not be allowed but +this one because that's about 1.5 MeV + + align:start position:0% +this one because that's about 1.5 MeV + + + align:start position:0% +this one because that's about 1.5 MeV +should be allowed but since that branch + + align:start position:0% +should be allowed but since that branch + + + align:start position:0% +should be allowed but since that branch +ratio or the probability of that + + align:start position:0% +ratio or the probability of that + + + align:start position:0% +ratio or the probability of that +happening is already so low I wonder if + + align:start position:0% +happening is already so low I wonder if + + + align:start position:0% +happening is already so low I wonder if +it even says yep beta ray with a max or + + align:start position:0% +it even says yep beta ray with a max or + + + align:start position:0% +it even says yep beta ray with a max or +average energy of 482 point 8 MeV we're + + align:start position:0% +average energy of 482 point 8 MeV we're + + + align:start position:0% +average energy of 482 point 8 MeV we're +gonna go over why that energy is so low + + align:start position:0% +gonna go over why that energy is so low + + + align:start position:0% +gonna go over why that energy is so low +when we talk about decay next week with + + align:start position:0% +when we talk about decay next week with + + + align:start position:0% +when we talk about decay next week with +a relative intensity of something with a + + align:start position:0% +a relative intensity of something with a + + + align:start position:0% +a relative intensity of something with a +lot of zeros before the decimal place so + + align:start position:0% +lot of zeros before the decimal place so + + + align:start position:0% +lot of zeros before the decimal place so +there you go like you said energies near + + align:start position:0% +there you go like you said energies near + + + align:start position:0% +there you go like you said energies near +1.0 to 2 MeV slightly above it are + + align:start position:0% +1.0 to 2 MeV slightly above it are + + + align:start position:0% +1.0 to 2 MeV slightly above it are +extremely unlikely but possible and + + align:start position:0% +extremely unlikely but possible and + + + align:start position:0% +extremely unlikely but possible and +measurable cool and then let's see what + + align:start position:0% +measurable cool and then let's see what + + + align:start position:0% +measurable cool and then let's see what +could have made argon-40 could have been + + align:start position:0% +could have made argon-40 could have been + + + align:start position:0% +could have made argon-40 could have been +beta decay from chlorine 40 so chlorine + + align:start position:0% +beta decay from chlorine 40 so chlorine + + + align:start position:0% +beta decay from chlorine 40 so chlorine +maybe was here and I don't think I have + + align:start position:0% +maybe was here and I don't think I have + + + align:start position:0% +maybe was here and I don't think I have +to draw any more so we've got an + + align:start position:0% +to draw any more so we've got an + + + align:start position:0% +to draw any more so we've got an +funny-looking parabola with a kink in it + + align:start position:0% +funny-looking parabola with a kink in it + + + align:start position:0% +funny-looking parabola with a kink in it +because really you have two bass + + align:start position:0% +because really you have two bass + + + align:start position:0% +because really you have two bass +parabolas overlapping I'm gonna go back + + align:start position:0% +parabolas overlapping I'm gonna go back + + + align:start position:0% +parabolas overlapping I'm gonna go back +to the screen so that the diagram from + + align:start position:0% +to the screen so that the diagram from + + + align:start position:0% +to the screen so that the diagram from +the notes makes a little more sense what + + align:start position:0% +the notes makes a little more sense what + + + align:start position:0% +the notes makes a little more sense what +we've kind of traced out here is that + + align:start position:0% +we've kind of traced out here is that + + + align:start position:0% +we've kind of traced out here is that +there's two overlapping parabolas here + + align:start position:0% +there's two overlapping parabolas here + + + align:start position:0% +there's two overlapping parabolas here +there's the one with the what is it the + + align:start position:0% +there's the one with the what is it the + + + align:start position:0% +there's the one with the what is it the +odd Z and the even Z so there you go + + align:start position:0% +odd Z and the even Z so there you go + + + align:start position:0% +odd Z and the even Z so there you go +just like the one on here which i think + + align:start position:0% +just like the one on here which i think + + + align:start position:0% +just like the one on here which i think +is for a different mass number yep 102 + + align:start position:0% +is for a different mass number yep 102 + + + align:start position:0% +is for a different mass number yep 102 +we get the same kind of behavior + + align:start position:0% +we get the same kind of behavior + + + align:start position:0% +we get the same kind of behavior +where things will mostly follow the + + align:start position:0% +where things will mostly follow the + + + align:start position:0% +where things will mostly follow the +lower-mass parabola but sometimes if + + align:start position:0% +lower-mass parabola but sometimes if + + + align:start position:0% +lower-mass parabola but sometimes if +something gets stuck here it can go + + align:start position:0% +something gets stuck here it can go + + + align:start position:0% +something gets stuck here it can go +either way to get more stable so I want + + align:start position:0% +either way to get more stable so I want + + + align:start position:0% +either way to get more stable so I want +to stop here for new stuff because this + + align:start position:0% +to stop here for new stuff because this + + + align:start position:0% +to stop here for new stuff because this +is precisely where I thought we'd be at + + align:start position:0% +is precisely where I thought we'd be at + + + align:start position:0% +is precisely where I thought we'd be at +the end of the week and in the next half + + align:start position:0% +the end of the week and in the next half + + + align:start position:0% +the end of the week and in the next half +an hour I'd like to open it up to + + align:start position:0% +an hour I'd like to open it up to + + + align:start position:0% +an hour I'd like to open it up to +questions or working things out together + + align:start position:0% +questions or working things out together + + + align:start position:0% +questions or working things out together +on the board or anything else you might + + align:start position:0% +on the board or anything else you might + + + align:start position:0% +on the board or anything else you might +have had yeah sure + + align:start position:0% + + + + align:start position:0% + +it's going to go in whatever when + + align:start position:0% +it's going to go in whatever when + + + align:start position:0% +it's going to go in whatever when +whatever way makes it more stable so + + align:start position:0% +whatever way makes it more stable so + + + align:start position:0% +whatever way makes it more stable so +you're never going to have a nucleus is + + align:start position:0% +you're never going to have a nucleus is + + + align:start position:0% +you're never going to have a nucleus is +going to spontaneously gain mass in + + align:start position:0% +going to spontaneously gain mass in + + + align:start position:0% +going to spontaneously gain mass in +order to get to a different path you can + + align:start position:0% +order to get to a different path you can + + + align:start position:0% +order to get to a different path you can +only go down on the mass axis but let's + + align:start position:0% +only go down on the mass axis but let's + + + align:start position:0% +only go down on the mass axis but let's +say you happen to be starting here at + + align:start position:0% +say you happen to be starting here at + + + align:start position:0% +say you happen to be starting here at +potassium-40 + + align:start position:0% +potassium-40 + + + align:start position:0% +potassium-40 +you can go down via either mechanism to + + align:start position:0% +you can go down via either mechanism to + + + align:start position:0% +you can go down via either mechanism to +the next mass parabola down + + align:start position:0% + + + + align:start position:0% + +that's quite if you're at argon you're + + align:start position:0% +that's quite if you're at argon you're + + + align:start position:0% +that's quite if you're at argon you're +stuck and in fact if you want to take a + + align:start position:0% +stuck and in fact if you want to take a + + + align:start position:0% +stuck and in fact if you want to take a +look what do I mean scientifically by + + align:start position:0% +look what do I mean scientifically by + + + align:start position:0% +look what do I mean scientifically by +stuck I mean stable argon-40 is a stable + + align:start position:0% +stuck I mean stable argon-40 is a stable + + + align:start position:0% +stuck I mean stable argon-40 is a stable +nucleus that comprises ninety nine point + + align:start position:0% +nucleus that comprises ninety nine point + + + align:start position:0% +nucleus that comprises ninety nine point +six percent of the argon so that's what + + align:start position:0% +six percent of the argon so that's what + + + align:start position:0% +six percent of the argon so that's what +I mean by stock is stable and if we look + + align:start position:0% +I mean by stock is stable and if we look + + + align:start position:0% +I mean by stock is stable and if we look +at the rest of the table of nuclides for + + align:start position:0% +at the rest of the table of nuclides for + + + align:start position:0% +at the rest of the table of nuclides for +similar looking places so let's hunt + + align:start position:0% +similar looking places so let's hunt + + + align:start position:0% +similar looking places so let's hunt +near potassium-40 so notice potassium-40 + + align:start position:0% +near potassium-40 so notice potassium-40 + + + align:start position:0% +near potassium-40 so notice potassium-40 +right here has got stable isotopes to + + align:start position:0% +right here has got stable isotopes to + + + align:start position:0% +right here has got stable isotopes to +the upper left and the lower right if we + + align:start position:0% +the upper left and the lower right if we + + + align:start position:0% +the upper left and the lower right if we +look back over here manganese 54 same + + align:start position:0% +look back over here manganese 54 same + + + align:start position:0% +look back over here manganese 54 same +deal it's got a stable isotope to the + + align:start position:0% +deal it's got a stable isotope to the + + + align:start position:0% +deal it's got a stable isotope to the +upper left and a stable one to the lower + + align:start position:0% +upper left and a stable one to the lower + + + align:start position:0% +upper left and a stable one to the lower +right how much you want to bet that when + + align:start position:0% +right how much you want to bet that when + + + align:start position:0% +right how much you want to bet that when +we click on manganese 54 it's got two + + align:start position:0% +we click on manganese 54 it's got two + + + align:start position:0% +we click on manganese 54 it's got two +possible parent new clients I'm sorry + + align:start position:0% +possible parent new clients I'm sorry + + + align:start position:0% +possible parent new clients I'm sorry +two possible decay math methods so let's + + align:start position:0% +two possible decay math methods so let's + + + align:start position:0% +two possible decay math methods so let's +take a look manganese 54 can either + + align:start position:0% +take a look manganese 54 can either + + + align:start position:0% +take a look manganese 54 can either +electron capture and positron decay to + + align:start position:0% +electron capture and positron decay to + + + align:start position:0% +electron capture and positron decay to +chromium 54 or beta decay to iron 54 + + align:start position:0% +chromium 54 or beta decay to iron 54 + + + align:start position:0% +chromium 54 or beta decay to iron 54 +let's take a look at one more to hammer + + align:start position:0% +let's take a look at one more to hammer + + + align:start position:0% +let's take a look at one more to hammer +the point home and I think that'll + + align:start position:0% +the point home and I think that'll + + + align:start position:0% +the point home and I think that'll +probably be enough cobalt 58 right near + + align:start position:0% +probably be enough cobalt 58 right near + + + align:start position:0% +probably be enough cobalt 58 right near +nickel 58 and iron 58 interesting that + + align:start position:0% +nickel 58 and iron 58 interesting that + + + align:start position:0% +nickel 58 and iron 58 interesting that +one's not allowed unless there's more + + align:start position:0% +one's not allowed unless there's more + + + align:start position:0% +one's not allowed unless there's more +down here so you can electron capture to + + align:start position:0% +down here so you can electron capture to + + + align:start position:0% +down here so you can electron capture to +iron 58 but there's no allowed decay to + + align:start position:0% +iron 58 but there's no allowed decay to + + + align:start position:0% +iron 58 but there's no allowed decay to +what was it nickel 58 okay let's look + + align:start position:0% +what was it nickel 58 okay let's look + + + align:start position:0% +what was it nickel 58 okay let's look +for more chlorine 36 has argon and + + align:start position:0% +for more chlorine 36 has argon and + + + align:start position:0% +for more chlorine 36 has argon and +sulfur on either side there it is + + align:start position:0% +sulfur on either side there it is + + + align:start position:0% +sulfur on either side there it is +beta-decay and electron capture and how + + align:start position:0% +beta-decay and electron capture and how + + + align:start position:0% +beta-decay and electron capture and how +much you want to bet there's basically + + align:start position:0% +much you want to bet there's basically + + + align:start position:0% +much you want to bet there's basically +never a positron here but basically not + + align:start position:0% +never a positron here but basically not + + + align:start position:0% +never a positron here but basically not +actually never so you get a positron + + align:start position:0% +actually never so you get a positron + + + align:start position:0% +actually never so you get a positron +0.01 percent of the time and electron + + align:start position:0% +0.01 percent of the time and electron + + + align:start position:0% +0.01 percent of the time and electron +capture one point eight nine percent of + + align:start position:0% +capture one point eight nine percent of + + + align:start position:0% +capture one point eight nine percent of +the time where's the other 98 and change + + align:start position:0% +the time where's the other 98 and change + + + align:start position:0% +the time where's the other 98 and change +percent right here in the beta decay so + + align:start position:0% +percent right here in the beta decay so + + + align:start position:0% +percent right here in the beta decay so +in this case chlorine 36 will + + align:start position:0% +in this case chlorine 36 will + + + align:start position:0% +in this case chlorine 36 will +preferentially beta decay if you also + + align:start position:0% +preferentially beta decay if you also + + + align:start position:0% +preferentially beta decay if you also +notice it's a let's see you don't know + + align:start position:0% +notice it's a let's see you don't know + + + align:start position:0% +notice it's a let's see you don't know +if that actually matters so but I'm + + align:start position:0% +if that actually matters so but I'm + + + align:start position:0% +if that actually matters so but I'm +gonna say it's more likely to beta decay + + align:start position:0% +gonna say it's more likely to beta decay + + + align:start position:0% +gonna say it's more likely to beta decay +so when you sum these up you get a + + align:start position:0% +so when you sum these up you get a + + + align:start position:0% +so when you sum these up you get a +hundred percent of the possible to case + + align:start position:0% +hundred percent of the possible to case + + + align:start position:0% +hundred percent of the possible to case +let's see how many energy levels there + + align:start position:0% +let's see how many energy levels there + + + align:start position:0% +let's see how many energy levels there +are there too hopefully not too many + + align:start position:0% +are there too hopefully not too many + + + align:start position:0% +are there too hopefully not too many +that qualifies as not too many yeah John + + align:start position:0% + + + + align:start position:0% + +they'll be due to those as well as some + + align:start position:0% +they'll be due to those as well as some + + + align:start position:0% +they'll be due to those as well as some +other processes which we're going to + + align:start position:0% +other processes which we're going to + + + align:start position:0% +other processes which we're going to +cover on decay but if you notice I've + + align:start position:0% +cover on decay but if you notice I've + + + align:start position:0% +cover on decay but if you notice I've +been giving you a lot of flash-forwards + + align:start position:0% +been giving you a lot of flash-forwards + + + align:start position:0% +been giving you a lot of flash-forwards +in this class we've introduced + + align:start position:0% +in this class we've introduced + + + align:start position:0% +in this class we've introduced +cross-sections as a thing that a + + align:start position:0% +cross-sections as a thing that a + + + align:start position:0% +cross-sections as a thing that a +proportionality constant between + + align:start position:0% +proportionality constant between + + + align:start position:0% +proportionality constant between +interaction probabilities we're going to + + align:start position:0% +interaction probabilities we're going to + + + align:start position:0% +interaction probabilities we're going to +hit them hard later I've also been kind + + align:start position:0% +hit them hard later I've also been kind + + + align:start position:0% +hit them hard later I've also been kind +of introducing or flash forwarding + + align:start position:0% +of introducing or flash forwarding + + + align:start position:0% +of introducing or flash forwarding +different methods of decay so there's + + align:start position:0% +different methods of decay so there's + + + align:start position:0% +different methods of decay so there's +also alpha decay + + align:start position:0% +also alpha decay + + + align:start position:0% +also alpha decay +there's also isomeric transition or + + align:start position:0% +there's also isomeric transition or + + + align:start position:0% +there's also isomeric transition or +gamma emission + + align:start position:0% +gamma emission + + + align:start position:0% +gamma emission +there's also spontaneous fission this is + + align:start position:0% +there's also spontaneous fission this is + + + align:start position:0% +there's also spontaneous fission this is +the whole basis behind how fission can + + align:start position:0% +the whole basis behind how fission can + + + align:start position:0% +the whole basis behind how fission can +get working without some sort of + + align:start position:0% +get working without some sort of + + + align:start position:0% +get working without some sort of +kick-starting elements so maybe now's a + + align:start position:0% +kick-starting elements so maybe now's a + + + align:start position:0% +kick-starting elements so maybe now's a +good time to show you let's go to + + align:start position:0% +good time to show you let's go to + + + align:start position:0% +good time to show you let's go to +uranium-235 and see how it decays a de + + align:start position:0% +uranium-235 and see how it decays a de + + + align:start position:0% +uranium-235 and see how it decays a de +ganar D undergoes alpha decay de thorium + + align:start position:0% +ganar D undergoes alpha decay de thorium + + + align:start position:0% +ganar D undergoes alpha decay de thorium +231 most of the time and if you look how + + align:start position:0% +231 most of the time and if you look how + + + align:start position:0% +231 most of the time and if you look how +it's no it's not terrible we can make + + align:start position:0% +it's no it's not terrible we can make + + + align:start position:0% +it's no it's not terrible we can make +sense of this it also undergoes SF which + + align:start position:0% +sense of this it also undergoes SF which + + + align:start position:0% +sense of this it also undergoes SF which +stands for a spontaneous fission so one + + align:start position:0% +stands for a spontaneous fission so one + + + align:start position:0% +stands for a spontaneous fission so one +out of every seven Lords it you know + + align:start position:0% +out of every seven Lords it you know + + + align:start position:0% +out of every seven Lords it you know +seven out of every billion times it will + + align:start position:0% +seven out of every billion times it will + + + align:start position:0% +seven out of every billion times it will +just spontaneously fizz into two fission + + align:start position:0% +just spontaneously fizz into two fission + + + align:start position:0% +just spontaneously fizz into two fission +products and this is why if you put + + align:start position:0% +products and this is why if you put + + + align:start position:0% +products and this is why if you put +enough uranium-235 together in one place + + align:start position:0% +enough uranium-235 together in one place + + + align:start position:0% +enough uranium-235 together in one place +you can make a critical reactor in + + align:start position:0% +you can make a critical reactor in + + + align:start position:0% +you can make a critical reactor in +reality you don't tend to want to put + + align:start position:0% +reality you don't tend to want to put + + + align:start position:0% +reality you don't tend to want to put +enough u-235 together to just + + align:start position:0% +enough u-235 together to just + + + align:start position:0% +enough u-235 together to just +spontaneously go critical we use other + + align:start position:0% +spontaneously go critical we use other + + + align:start position:0% +spontaneously go critical we use other +isotopes as Kickstarter's for example + + align:start position:0% +isotopes as Kickstarter's for example + + + align:start position:0% +isotopes as Kickstarter's for example +californium I think it's two fifty-two + + align:start position:0% +californium I think it's two fifty-two + + + align:start position:0% +californium I think it's two fifty-two +let's take a quick look there we go + + align:start position:0% +let's take a quick look there we go + + + align:start position:0% +let's take a quick look there we go +californium 252 undergo spontaneous + + align:start position:0% +californium 252 undergo spontaneous + + + align:start position:0% +californium 252 undergo spontaneous +fission three percent of the time it's + + align:start position:0% +fission three percent of the time it's + + + align:start position:0% +fission three percent of the time it's +even heavier even more unstable so there + + align:start position:0% +even heavier even more unstable so there + + + align:start position:0% +even heavier even more unstable so there +is a reactor called high fer or the high + + align:start position:0% +is a reactor called high fer or the high + + + align:start position:0% +is a reactor called high fer or the high +flux isotope reactor at Oak Ridge + + align:start position:0% +flux isotope reactor at Oak Ridge + + + align:start position:0% +flux isotope reactor at Oak Ridge +National Lab one of its main outputs is + + align:start position:0% +National Lab one of its main outputs is + + + align:start position:0% +National Lab one of its main outputs is +californium Kickstarter's for reactors + + align:start position:0% +californium Kickstarter's for reactors + + + align:start position:0% +californium Kickstarter's for reactors +so to get things going you put a little + + align:start position:0% +so to get things going you put a little + + + align:start position:0% +so to get things going you put a little +bit of californium in as a gigantic + + align:start position:0% +bit of californium in as a gigantic + + + align:start position:0% +bit of californium in as a gigantic +neutron source and then you don't really + + align:start position:0% +neutron source and then you don't really + + + align:start position:0% +neutron source and then you don't really +need it anymore once it gets going so + + align:start position:0% +need it anymore once it gets going so + + + align:start position:0% +need it anymore once it gets going so +it's one of the safer ways of starting + + align:start position:0% +it's one of the safer ways of starting + + + align:start position:0% +it's one of the safer ways of starting +up a reactor is put in a crazy neutron + + align:start position:0% +up a reactor is put in a crazy neutron + + + align:start position:0% +up a reactor is put in a crazy neutron +source and then once it gets going take + + align:start position:0% +source and then once it gets going take + + + align:start position:0% +source and then once it gets going take +it out or leave it in and burn it I'm + + align:start position:0% +it out or leave it in and burn it I'm + + + align:start position:0% +it out or leave it in and burn it I'm +not actually sure which one they do yep + + align:start position:0% + + + + align:start position:0% + +it is when we get to now is a good time + + align:start position:0% +it is when we get to now is a good time + + + align:start position:0% +it is when we get to now is a good time +to introduce the super-heavy element + + align:start position:0% +to introduce the super-heavy element + + + align:start position:0% +to introduce the super-heavy element +since you asked so a lot of these older + + align:start position:0% +since you asked so a lot of these older + + + align:start position:0% +since you asked so a lot of these older +elements were named after all actually + + align:start position:0% +elements were named after all actually + + + align:start position:0% +elements were named after all actually +this is kind of a hobby of mine + + align:start position:0% +this is kind of a hobby of mine + + + align:start position:0% +this is kind of a hobby of mine +so I don't know if you guys saw the + + align:start position:0% +so I don't know if you guys saw the + + + align:start position:0% +so I don't know if you guys saw the +periodic table outside + + align:start position:0% +periodic table outside + + + align:start position:0% +periodic table outside +I collect elements because if you're + + align:start position:0% +I collect elements because if you're + + + align:start position:0% +I collect elements because if you're +gonna collect something you might as + + align:start position:0% +gonna collect something you might as + + + align:start position:0% +gonna collect something you might as +well collect everything that everything + + align:start position:0% +well collect everything that everything + + + align:start position:0% +well collect everything that everything +else is made of it's the same reason I + + align:start position:0% +else is made of it's the same reason I + + + align:start position:0% +else is made of it's the same reason I +went into nuclear energy + + align:start position:0% +went into nuclear energy + + + align:start position:0% +went into nuclear energy +I started off course 6 or 6/1 + + align:start position:0% +I started off course 6 or 6/1 + + + align:start position:0% +I started off course 6 or 6/1 +specifically electrical and I was like + + align:start position:0% +specifically electrical and I was like + + + align:start position:0% +specifically electrical and I was like +well I could be designing like the next + + align:start position:0% +well I could be designing like the next + + + align:start position:0% +well I could be designing like the next +screen for a cell phone or we could + + align:start position:0% +screen for a cell phone or we could + + + align:start position:0% +screen for a cell phone or we could +solve the energy problem which is the + + align:start position:0% +solve the energy problem which is the + + + align:start position:0% +solve the energy problem which is the +problem all others are based off of so + + align:start position:0% +problem all others are based off of so + + + align:start position:0% +problem all others are based off of so +my whole life theme has been go to the + + align:start position:0% +my whole life theme has been go to the + + + align:start position:0% +my whole life theme has been go to the +source that's why I came here in high + + align:start position:0% +source that's why I came here in high + + + align:start position:0% +source that's why I came here in high +school and never left that's why I + + align:start position:0% +school and never left that's why I + + + align:start position:0% +school and never left that's why I +declared course 22 that's why I collect + + align:start position:0% +declared course 22 that's why I collect + + + align:start position:0% +declared course 22 that's why I collect +elements and probably is the reason for + + align:start position:0% +elements and probably is the reason for + + + align:start position:0% +elements and probably is the reason for +many other things which only a + + align:start position:0% +many other things which only a + + + align:start position:0% +many other things which only a +psychiatrist could diagnose but let's + + align:start position:0% +psychiatrist could diagnose but let's + + + align:start position:0% +psychiatrist could diagnose but let's +look at some of the other elements for + + align:start position:0% +look at some of the other elements for + + + align:start position:0% +look at some of the other elements for +example yttrium I think it has an + + align:start position:0% +example yttrium I think it has an + + + align:start position:0% +example yttrium I think it has an +isotope 40 anyone know no it doesn't + + align:start position:0% +isotope 40 anyone know no it doesn't + + + align:start position:0% +isotope 40 anyone know no it doesn't +have a 40 what about a 50 60 hundred + + align:start position:0% +have a 40 what about a 50 60 hundred + + + align:start position:0% +have a 40 what about a 50 60 hundred +whatever at least it knew that why was + + align:start position:0% +whatever at least it knew that why was + + + align:start position:0% +whatever at least it knew that why was +you a trio anyone know where this is + + align:start position:0% +you a trio anyone know where this is + + + align:start position:0% +you a trio anyone know where this is +coming from 89 seems high oh my god + + align:start position:0% +coming from 89 seems high oh my god + + + align:start position:0% +coming from 89 seems high oh my god +you're right okay gotcha you work with + + align:start position:0% +you're right okay gotcha you work with + + + align:start position:0% +you're right okay gotcha you work with +it awesome + + align:start position:0% +it awesome + + + align:start position:0% +it awesome +anyone know what this is all about get + + align:start position:0% +anyone know what this is all about get + + + align:start position:0% +anyone know what this is all about get +trium there's a town called Iturbi in + + align:start position:0% +trium there's a town called Iturbi in + + + align:start position:0% +trium there's a town called Iturbi in +sweden where large deposits of yttrium + + align:start position:0% +sweden where large deposits of yttrium + + + align:start position:0% +sweden where large deposits of yttrium +and ytterbium or YB tend to be found or + + align:start position:0% +and ytterbium or YB tend to be found or + + + align:start position:0% +and ytterbium or YB tend to be found or +DB name for dubnium so let's say the + + align:start position:0% +DB name for dubnium so let's say the + + + align:start position:0% +DB name for dubnium so let's say the +really basic elements tend to come from + + align:start position:0% +really basic elements tend to come from + + + align:start position:0% +really basic elements tend to come from +Latin F F stands for iron which actually + + align:start position:0% +Latin F F stands for iron which actually + + + align:start position:0% +Latin F F stands for iron which actually +stands for theorem led is plumbum gold + + align:start position:0% +stands for theorem led is plumbum gold + + + align:start position:0% +stands for theorem led is plumbum gold +as Orem silver AG is argenteum I don't + + align:start position:0% +as Orem silver AG is argenteum I don't + + + align:start position:0% +as Orem silver AG is argenteum I don't +know if I'm saying that right + + align:start position:0% +know if I'm saying that right + + + align:start position:0% +know if I'm saying that right +I never took Latin and I've never heard + + align:start position:0% +I never took Latin and I've never heard + + + align:start position:0% +I never took Latin and I've never heard +it spoken of course and then a lot of + + align:start position:0% +it spoken of course and then a lot of + + + align:start position:0% +it spoken of course and then a lot of +the heavier and heavier elements as we + + align:start position:0% +the heavier and heavier elements as we + + + align:start position:0% +the heavier and heavier elements as we +go our being named for more and more + + align:start position:0% +go our being named for more and more + + + align:start position:0% +go our being named for more and more +famous scientists or places where they + + align:start position:0% +famous scientists or places where they + + + align:start position:0% +famous scientists or places where they +tend to be made like dB I'm gonna guess + + align:start position:0% +tend to be made like dB I'm gonna guess + + + align:start position:0% +tend to be made like dB I'm gonna guess +264 a mass there oh nice for a doob nah + + align:start position:0% +264 a mass there oh nice for a doob nah + + + align:start position:0% +264 a mass there oh nice for a doob nah +in Russia that has got one of the few + + align:start position:0% +in Russia that has got one of the few + + + align:start position:0% +in Russia that has got one of the few +gigantic + + align:start position:0% +gigantic + + + align:start position:0% +gigantic +for heavy element colliders where + + align:start position:0% +for heavy element colliders where + + + align:start position:0% +for heavy element colliders where +they're constantly synthesizing and + + align:start position:0% +they're constantly synthesizing and + + + align:start position:0% +they're constantly synthesizing and +characterizing these super-heavy + + align:start position:0% +characterizing these super-heavy + + + align:start position:0% +characterizing these super-heavy +elements so finally they said you know + + align:start position:0% +elements so finally they said you know + + + align:start position:0% +elements so finally they said you know +what they've made enough of these in + + align:start position:0% +what they've made enough of these in + + + align:start position:0% +what they've made enough of these in +Dubna let's name one of the elements + + align:start position:0% +Dubna let's name one of the elements + + + align:start position:0% +Dubna let's name one of the elements +after them or SG seaborgium for glenn + + align:start position:0% +after them or SG seaborgium for glenn + + + align:start position:0% +after them or SG seaborgium for glenn +seaborg or n o nobelium for Alfred Nobel + + align:start position:0% +seaborg or n o nobelium for Alfred Nobel + + + align:start position:0% +seaborg or n o nobelium for Alfred Nobel +yep + + align:start position:0% + + + + align:start position:0% + +ah do they intersect I've never seen a + + align:start position:0% +ah do they intersect I've never seen a + + + align:start position:0% +ah do they intersect I've never seen a +case where they intersect that would + + align:start position:0% +case where they intersect that would + + + align:start position:0% +case where they intersect that would +make for a crazy situation indeed + + align:start position:0% +make for a crazy situation indeed + + + align:start position:0% +make for a crazy situation indeed +however part of what the homework + + align:start position:0% +however part of what the homework + + + align:start position:0% +however part of what the homework +assignments about is to derive an + + align:start position:0% +assignments about is to derive an + + + align:start position:0% +assignments about is to derive an +analytical form for a mass parabola and + + align:start position:0% +analytical form for a mass parabola and + + + align:start position:0% +analytical form for a mass parabola and +then check the data to see how well it + + align:start position:0% +then check the data to see how well it + + + align:start position:0% +then check the data to see how well it +works so for any cases where you have an + + align:start position:0% +works so for any cases where you have an + + + align:start position:0% +works so for any cases where you have an +even mass number and you have either odd + + align:start position:0% +even mass number and you have either odd + + + align:start position:0% +even mass number and you have either odd +odd or even even nuclei you can check + + align:start position:0% +odd or even even nuclei you can check + + + align:start position:0% +odd or even even nuclei you can check +those equations analytically to see if + + align:start position:0% +those equations analytically to see if + + + align:start position:0% +those equations analytically to see if +they'll intersect + + align:start position:0% + + + + align:start position:0% + +so the top parabola for potassium-40 + + align:start position:0% +so the top parabola for potassium-40 + + + align:start position:0% +so the top parabola for potassium-40 +let's take a quick look at how many + + align:start position:0% +let's take a quick look at how many + + + align:start position:0% +let's take a quick look at how many +protons and neutrons it has potassium + + align:start position:0% +protons and neutrons it has potassium + + + align:start position:0% +protons and neutrons it has potassium +has a proton number of 19 which means it + + align:start position:0% +has a proton number of 19 which means it + + + align:start position:0% +has a proton number of 19 which means it +has a neutron number of 21 so the top + + align:start position:0% +has a neutron number of 21 so the top + + + align:start position:0% +has a neutron number of 21 so the top +parabola is odd n and odd Z where the + + align:start position:0% +parabola is odd n and odd Z where the + + + align:start position:0% +parabola is odd n and odd Z where the +bottom one is even N and even C whereas + + align:start position:0% +bottom one is even N and even C whereas + + + align:start position:0% +bottom one is even N and even C whereas +for odd mass number nuclei it has to be + + align:start position:0% +for odd mass number nuclei it has to be + + + align:start position:0% +for odd mass number nuclei it has to be +either odd even or even odd else it + + align:start position:0% +either odd even or even odd else it + + + align:start position:0% +either odd even or even odd else it +would be even which is a funny sentence + + align:start position:0% +would be even which is a funny sentence + + + align:start position:0% +would be even which is a funny sentence +when you say it all out loud yeah so + + align:start position:0% +when you say it all out loud yeah so + + + align:start position:0% +when you say it all out loud yeah so +that's the idea here is that notice that + + align:start position:0% +that's the idea here is that notice that + + + align:start position:0% +that's the idea here is that notice that +the even even parabola tends to be + + align:start position:0% +the even even parabola tends to be + + + align:start position:0% +the even even parabola tends to be +further down all those nuclear magic + + align:start position:0% +further down all those nuclear magic + + + align:start position:0% +further down all those nuclear magic +numbers - 8 20 28 I'm not going to quote + + align:start position:0% +numbers - 8 20 28 I'm not going to quote + + + align:start position:0% +numbers - 8 20 28 I'm not going to quote +the rest those little ones I know all + + align:start position:0% +the rest those little ones I know all + + + align:start position:0% +the rest those little ones I know all +even numbers so any other questions on + + align:start position:0% +even numbers so any other questions on + + + align:start position:0% +even numbers so any other questions on +these math problems before we launch + + align:start position:0% +these math problems before we launch + + + align:start position:0% +these math problems before we launch +into super heavy elements yep uh-huh + + align:start position:0% + + + + align:start position:0% + +analytically or experimentally which + + align:start position:0% +analytically or experimentally which + + + align:start position:0% +analytically or experimentally which +question so analytically analytically + + align:start position:0% +question so analytically analytically + + + align:start position:0% +question so analytically analytically +there should be some isotope of well not + + align:start position:0% +there should be some isotope of well not + + + align:start position:0% +there should be some isotope of well not +potassium that wouldn't be allowed so in + + align:start position:0% +potassium that wouldn't be allowed so in + + + align:start position:0% +potassium that wouldn't be allowed so in +this case the the stable element + + align:start position:0% +this case the the stable element + + + align:start position:0% +this case the the stable element +positions have got to kind of switch off + + align:start position:0% +positions have got to kind of switch off + + + align:start position:0% +positions have got to kind of switch off +shouldn't they so if that's potassium 40 + + align:start position:0% +shouldn't they so if that's potassium 40 + + + align:start position:0% +shouldn't they so if that's potassium 40 +that would still have to be potassium + + align:start position:0% +that would still have to be potassium + + + align:start position:0% +that would still have to be potassium +you don't really have another choice + + align:start position:0% +you don't really have another choice + + + align:start position:0% +you don't really have another choice +there isn't really a position there is + + align:start position:0% +there isn't really a position there is + + + align:start position:0% +there isn't really a position there is +there analytically that's the + + align:start position:0% +there analytically that's the + + + align:start position:0% +there analytically that's the +interesting thing is that you can either + + align:start position:0% +interesting thing is that you can either + + + align:start position:0% +interesting thing is that you can either +be odd odd or even even for an even mass + + align:start position:0% +be odd odd or even even for an even mass + + + align:start position:0% +be odd odd or even even for an even mass +number but you can't just take off one + + align:start position:0% +number but you can't just take off one + + + align:start position:0% +number but you can't just take off one +Neutron from potassium-40 and then + + align:start position:0% +Neutron from potassium-40 and then + + + align:start position:0% +Neutron from potassium-40 and then +you've got potassium 39 then you're on a + + align:start position:0% +you've got potassium 39 then you're on a + + + align:start position:0% +you've got potassium 39 then you're on a +different mass number or if you exchange + + align:start position:0% +different mass number or if you exchange + + + align:start position:0% +different mass number or if you exchange +a proton and a neutron which you pretty + + align:start position:0% +a proton and a neutron which you pretty + + + align:start position:0% +a proton and a neutron which you pretty +much do in either of these directions + + align:start position:0% +much do in either of these directions + + + align:start position:0% +much do in either of these directions +there's no way to get straight down here + + align:start position:0% +there's no way to get straight down here + + + align:start position:0% +there's no way to get straight down here +yep + + align:start position:0% + + + + align:start position:0% + +fraud what proof sorry yeah let's go + + align:start position:0% +fraud what proof sorry yeah let's go + + + align:start position:0% +fraud what proof sorry yeah let's go +back to that slide just to make sure you + + align:start position:0% +back to that slide just to make sure you + + + align:start position:0% +back to that slide just to make sure you +mean the pairing term in the semi + + align:start position:0% +mean the pairing term in the semi + + + align:start position:0% +mean the pairing term in the semi +empirical mass formula yeah yeah + + align:start position:0% +empirical mass formula yeah yeah + + + align:start position:0% +empirical mass formula yeah yeah +so for aw dog nuclei and D Delta is + + align:start position:0% +so for aw dog nuclei and D Delta is + + + align:start position:0% +so for aw dog nuclei and D Delta is +negative which means lower binding + + align:start position:0% +negative which means lower binding + + + align:start position:0% +negative which means lower binding +energy which means higher mass and + + align:start position:0% +energy which means higher mass and + + + align:start position:0% +energy which means higher mass and +that's why we see it bump up on the mass + + align:start position:0% +that's why we see it bump up on the mass + + + align:start position:0% +that's why we see it bump up on the mass +right here yep and you have a second + + align:start position:0% +right here yep and you have a second + + + align:start position:0% +right here yep and you have a second +part of the question + + align:start position:0% + + + + align:start position:0% + +Oh + + align:start position:0% + + + + align:start position:0% + +ah we can actually relate so we can + + align:start position:0% +ah we can actually relate so we can + + + align:start position:0% +ah we can actually relate so we can +relate the binding energy to the mass + + align:start position:0% +relate the binding energy to the mass + + + align:start position:0% +relate the binding energy to the mass +and the mass parabola analytically + + align:start position:0% +and the mass parabola analytically + + + align:start position:0% +and the mass parabola analytically +because the binding energy is equal to Z + + align:start position:0% +because the binding energy is equal to Z + + + align:start position:0% +because the binding energy is equal to Z +times protons plus n times mass of + + align:start position:0% +times protons plus n times mass of + + + align:start position:0% +times protons plus n times mass of +neutron minus the actual mass of that + + align:start position:0% +neutron minus the actual mass of that + + + align:start position:0% +neutron minus the actual mass of that +same nucleus a comma Z so they're + + align:start position:0% +same nucleus a comma Z so they're + + + align:start position:0% +same nucleus a comma Z so they're +actually directly related just + + align:start position:0% +actually directly related just + + + align:start position:0% +actually directly related just +negatively so something with a higher + + align:start position:0% +negatively so something with a higher + + + align:start position:0% +negatively so something with a higher +mass is going to have a low binding + + align:start position:0% +mass is going to have a low binding + + + align:start position:0% +mass is going to have a low binding +energy which means it's less bound and + + align:start position:0% +energy which means it's less bound and + + + align:start position:0% +energy which means it's less bound and +less stable and indeed the further up + + align:start position:0% +less stable and indeed the further up + + + align:start position:0% +less stable and indeed the further up +the mass scale we go the higher those + + align:start position:0% +the mass scale we go the higher those + + + align:start position:0% +the mass scale we go the higher those +beta or electron capture or positron + + align:start position:0% +beta or electron capture or positron + + + align:start position:0% +beta or electron capture or positron +energies are and there's another thing + + align:start position:0% +energies are and there's another thing + + + align:start position:0% +energies are and there's another thing +you can check to which is the half-life + + align:start position:0% +you can check to which is the half-life + + + align:start position:0% +you can check to which is the half-life +half-life is what we'll be talking about + + align:start position:0% +half-life is what we'll be talking about + + + align:start position:0% +half-life is what we'll be talking about +on Tuesday it's how long before an + + align:start position:0% +on Tuesday it's how long before an + + + align:start position:0% +on Tuesday it's how long before an +average amount of a substance has + + align:start position:0% +average amount of a substance has + + + align:start position:0% +average amount of a substance has +undergone radioactive decay so let's + + align:start position:0% +undergone radioactive decay so let's + + + align:start position:0% +undergone radioactive decay so let's +look at some of these isotopes and start + + align:start position:0% +look at some of these isotopes and start + + + align:start position:0% +look at some of these isotopes and start +looking at half-life trends as another + + align:start position:0% +looking at half-life trends as another + + + align:start position:0% +looking at half-life trends as another +measure of stability so potassium-40 has + + align:start position:0% +measure of stability so potassium-40 has + + + align:start position:0% +measure of stability so potassium-40 has +an exceptionally long half-life so it's + + align:start position:0% +an exceptionally long half-life so it's + + + align:start position:0% +an exceptionally long half-life so it's +relatively stable + + align:start position:0% +relatively stable + + + align:start position:0% +relatively stable +let's take a look not at either the + + align:start position:0% +let's take a look not at either the + + + align:start position:0% +let's take a look not at either the +stable isotopes but let's go up the mass + + align:start position:0% +stable isotopes but let's go up the mass + + + align:start position:0% +stable isotopes but let's go up the mass +parabola chain in one direction calcium + + align:start position:0% +parabola chain in one direction calcium + + + align:start position:0% +parabola chain in one direction calcium +for T scandium-46 can diem for T + + align:start position:0% +for T scandium-46 can diem for T + + + align:start position:0% +for T scandium-46 can diem for T +scandium 45 less than a second and it's + + align:start position:0% +scandium 45 less than a second and it's + + + align:start position:0% +scandium 45 less than a second and it's +got quite a high decay energy by + + align:start position:0% +got quite a high decay energy by + + + align:start position:0% +got quite a high decay energy by +whatever method you want to use let's go + + align:start position:0% +whatever method you want to use let's go + + + align:start position:0% +whatever method you want to use let's go +up to titanium for T anyone want to + + align:start position:0% +up to titanium for T anyone want to + + + align:start position:0% +up to titanium for T anyone want to +guess is eating the half-life is gonna + + align:start position:0% +guess is eating the half-life is gonna + + + align:start position:0% +guess is eating the half-life is gonna +go up or down let's see if the half-life + + align:start position:0% +go up or down let's see if the half-life + + + align:start position:0% +go up or down let's see if the half-life +goes down we know the decay energy goes + + align:start position:0% +goes down we know the decay energy goes + + + align:start position:0% +goes down we know the decay energy goes +up indeed half-life goes down from 182 + + align:start position:0% +up indeed half-life goes down from 182 + + + align:start position:0% +up indeed half-life goes down from 182 +milliseconds to 50 milliseconds and + + align:start position:0% +milliseconds to 50 milliseconds and + + + align:start position:0% +milliseconds to 50 milliseconds and +let's say titanium forty could have come + + align:start position:0% +let's say titanium forty could have come + + + align:start position:0% +let's say titanium forty could have come +from Wow two proton decay from cr.42 + + align:start position:0% +from Wow two proton decay from cr.42 + + + align:start position:0% +from Wow two proton decay from cr.42 +with a half-life of 350 nano seconds so + + align:start position:0% +with a half-life of 350 nano seconds so + + + align:start position:0% +with a half-life of 350 nano seconds so +as we go up the mass ladder and down the + + align:start position:0% +as we go up the mass ladder and down the + + + align:start position:0% +as we go up the mass ladder and down the +stability ladder the half-life decreases + + align:start position:0% +stability ladder the half-life decreases + + + align:start position:0% +stability ladder the half-life decreases +which kind of follows intuitively + + align:start position:0% +which kind of follows intuitively + + + align:start position:0% +which kind of follows intuitively +something that's exceptional + + align:start position:0% +something that's exceptional + + + align:start position:0% +something that's exceptional +Stables should have a half-life of + + align:start position:0% +Stables should have a half-life of + + + align:start position:0% +Stables should have a half-life of +infinity and something that's + + align:start position:0% +infinity and something that's + + + align:start position:0% +infinity and something that's +exceptionally unstable should just blow + + align:start position:0% +exceptionally unstable should just blow + + + align:start position:0% +exceptionally unstable should just blow +apart instantly like remember the first + + align:start position:0% +apart instantly like remember the first + + + align:start position:0% +apart instantly like remember the first +week of class we talked about helium for + + align:start position:0% +week of class we talked about helium for + + + align:start position:0% +week of class we talked about helium for +grabbing a neutron becoming helium 5 and + + align:start position:0% +grabbing a neutron becoming helium 5 and + + + align:start position:0% +grabbing a neutron becoming helium 5 and +instantaneously going back to helium 4 + + align:start position:0% +instantaneously going back to helium 4 + + + align:start position:0% +instantaneously going back to helium 4 +if you look at helium 5 it's half-life + + align:start position:0% +if you look at helium 5 it's half-life + + + align:start position:0% +if you look at helium 5 it's half-life +is measured in MeV or 7 times 10 to the + + align:start position:0% +is measured in MeV or 7 times 10 to the + + + align:start position:0% +is measured in MeV or 7 times 10 to the +minus seventh femtoseconds so if helium + + align:start position:0% +minus seventh femtoseconds so if helium + + + align:start position:0% +minus seventh femtoseconds so if helium +4 absorbs a neutron it simply doesn't + + align:start position:0% +4 absorbs a neutron it simply doesn't + + + align:start position:0% +4 absorbs a neutron it simply doesn't +want it and gets rid of it in ten to the + + align:start position:0% +want it and gets rid of it in ten to the + + + align:start position:0% +want it and gets rid of it in ten to the +minus seven femtoseconds which would + + align:start position:0% +minus seven femtoseconds which would + + + align:start position:0% +minus seven femtoseconds which would +tell us that it's exceptionally unstable + + align:start position:0% + + + + align:start position:0% + +so I hope that's a long-winded answer to + + align:start position:0% +so I hope that's a long-winded answer to + + + align:start position:0% +so I hope that's a long-winded answer to +that question but what does it mean to + + align:start position:0% +that question but what does it mean to + + + align:start position:0% +that question but what does it mean to +go to be going up in the mass levels any + + align:start position:0% +go to be going up in the mass levels any + + + align:start position:0% +go to be going up in the mass levels any +other questions on mass parabolas or the + + align:start position:0% +other questions on mass parabolas or the + + + align:start position:0% +other questions on mass parabolas or the +liquid drop model or stability in + + align:start position:0% +liquid drop model or stability in + + + align:start position:0% +liquid drop model or stability in +general yes + + align:start position:0% + + + + align:start position:0% + +so if you're changing one neutron to a + + align:start position:0% +so if you're changing one neutron to a + + + align:start position:0% +so if you're changing one neutron to a +proton in each case you're switching + + align:start position:0% +proton in each case you're switching + + + align:start position:0% +proton in each case you're switching +back and forth from the odd odd to the + + align:start position:0% +back and forth from the odd odd to the + + + align:start position:0% +back and forth from the odd odd to the +even even mass parabolas so if I were to + + align:start position:0% +even even mass parabolas so if I were to + + + align:start position:0% +even even mass parabolas so if I were to +redraw these dots more to scale this + + align:start position:0% +redraw these dots more to scale this + + + align:start position:0% +redraw these dots more to scale this +would have to be on the odd odd and oh + + align:start position:0% +would have to be on the odd odd and oh + + + align:start position:0% +would have to be on the odd odd and oh +let me draw them a little better yep + + align:start position:0% +let me draw them a little better yep + + + align:start position:0% +let me draw them a little better yep +that's on the odd odd and that's on the + + align:start position:0% +that's on the odd odd and that's on the + + + align:start position:0% +that's on the odd odd and that's on the +even even yeah so excuse my poor drawing + + align:start position:0% +even even yeah so excuse my poor drawing + + + align:start position:0% +even even yeah so excuse my poor drawing +skills but if you're switching one + + align:start position:0% +skills but if you're switching one + + + align:start position:0% +skills but if you're switching one +proton to a neutron or vice versa by + + align:start position:0% +proton to a neutron or vice versa by + + + align:start position:0% +proton to a neutron or vice versa by +definition you're jumping back and forth + + align:start position:0% +definition you're jumping back and forth + + + align:start position:0% +definition you're jumping back and forth +between these parabolas that's a good + + align:start position:0% +between these parabolas that's a good + + + align:start position:0% +between these parabolas that's a good +question for clarification you had a + + align:start position:0% +question for clarification you had a + + + align:start position:0% +question for clarification you had a +question too + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +the semi-empirical I'm sorry the semi + + align:start position:0% +the semi-empirical I'm sorry the semi + + + align:start position:0% +the semi-empirical I'm sorry the semi +empirical mass formula is a good way to + + align:start position:0% +empirical mass formula is a good way to + + + align:start position:0% +empirical mass formula is a good way to +get an analytical guess at most of them + + align:start position:0% +get an analytical guess at most of them + + + align:start position:0% +get an analytical guess at most of them +if you want an exact answer always use + + align:start position:0% +if you want an exact answer always use + + + align:start position:0% +if you want an exact answer always use +the actual binding energy I would not + + align:start position:0% +the actual binding energy I would not + + + align:start position:0% +the actual binding energy I would not +say it's used much now except well + + align:start position:0% +say it's used much now except well + + + align:start position:0% +say it's used much now except well +that's gonna be one of your homework + + align:start position:0% +that's gonna be one of your homework + + + align:start position:0% +that's gonna be one of your homework +questions is this formula predicts that + + align:start position:0% +questions is this formula predicts that + + + align:start position:0% +questions is this formula predicts that +as you get heavier and heavier and + + align:start position:0% +as you get heavier and heavier and + + + align:start position:0% +as you get heavier and heavier and +heavier nuclei should just continuously + + align:start position:0% +heavier nuclei should just continuously + + + align:start position:0% +heavier nuclei should just continuously +get less stable and that was as of when + + align:start position:0% +get less stable and that was as of when + + + align:start position:0% +get less stable and that was as of when +this was derived let's say decades ago + + align:start position:0% +this was derived let's say decades ago + + + align:start position:0% +this was derived let's say decades ago +we now know something different is + + align:start position:0% +we now know something different is + + + align:start position:0% +we now know something different is +happening so if you look at the table of + + align:start position:0% +happening so if you look at the table of + + + align:start position:0% +happening so if you look at the table of +nuclides you can sort of see some swells + + align:start position:0% +nuclides you can sort of see some swells + + + align:start position:0% +nuclides you can sort of see some swells +in the number of black pixels until it + + align:start position:0% +in the number of black pixels until it + + + align:start position:0% +in the number of black pixels until it +cuts off and this region actually where + + align:start position:0% +cuts off and this region actually where + + + align:start position:0% +cuts off and this region actually where +we think super-heavy elements happen I + + align:start position:0% +we think super-heavy elements happen I + + + align:start position:0% +we think super-heavy elements happen I +want to jump to the actual table of + + align:start position:0% +want to jump to the actual table of + + + align:start position:0% +want to jump to the actual table of +nuclides which I'll say is our snapshot + + align:start position:0% +nuclides which I'll say is our snapshot + + + align:start position:0% +nuclides which I'll say is our snapshot +of knowledge today and go all the way to + + align:start position:0% +of knowledge today and go all the way to + + + align:start position:0% +of knowledge today and go all the way to +the top and our knowledge kind of cuts + + align:start position:0% +the top and our knowledge kind of cuts + + + align:start position:0% +the top and our knowledge kind of cuts +off at these elements which are for now + + align:start position:0% +off at these elements which are for now + + + align:start position:0% +off at these elements which are for now +temporarily named in a very uncreated + + align:start position:0% +temporarily named in a very uncreated + + + align:start position:0% +temporarily named in a very uncreated +way we don't even know anything about + + align:start position:0% +way we don't even know anything about + + + align:start position:0% +way we don't even know anything about +them uun probably going to have a proton + + align:start position:0% +them uun probably going to have a proton + + + align:start position:0% +them uun probably going to have a proton +number of what 110 I don't know what the + + align:start position:0% +number of what 110 I don't know what the + + + align:start position:0% +number of what 110 I don't know what the +prefixes are but you you you would be on + + align:start position:0% +prefixes are but you you you would be on + + + align:start position:0% +prefixes are but you you you would be on +one one one probably has 111 protons + + align:start position:0% +one one one probably has 111 protons + + + align:start position:0% +one one one probably has 111 protons +beyond here off the screen or probably + + align:start position:0% +beyond here off the screen or probably + + + align:start position:0% +beyond here off the screen or probably +up into the next room it's predicted + + align:start position:0% +up into the next room it's predicted + + + align:start position:0% +up into the next room it's predicted +that once you approach the next magic + + align:start position:0% +that once you approach the next magic + + + align:start position:0% +that once you approach the next magic +number in nuclei there should be an + + align:start position:0% +number in nuclei there should be an + + + align:start position:0% +number in nuclei there should be an +island of stability where and it may not + + align:start position:0% +island of stability where and it may not + + + align:start position:0% +island of stability where and it may not +necessarily be totally stable but the + + align:start position:0% +necessarily be totally stable but the + + + align:start position:0% +necessarily be totally stable but the +half-life should go up again and we + + align:start position:0% +half-life should go up again and we + + + align:start position:0% +half-life should go up again and we +should be able to synthesize super-heavy + + align:start position:0% +should be able to synthesize super-heavy + + + align:start position:0% +should be able to synthesize super-heavy +matter and if you actually graph Neutron + + align:start position:0% +matter and if you actually graph Neutron + + + align:start position:0% +matter and if you actually graph Neutron +number versus half-life so notice how we + + align:start position:0% +number versus half-life so notice how we + + + align:start position:0% +number versus half-life so notice how we +were looking at half-life as a measure + + align:start position:0% +were looking at half-life as a measure + + + align:start position:0% +were looking at half-life as a measure +of stability it starts to go up then + + align:start position:0% +of stability it starts to go up then + + + align:start position:0% +of stability it starts to go up then +comes down and then to the extent of our + + align:start position:0% +comes down and then to the extent of our + + + align:start position:0% +comes down and then to the extent of our +knowledge it is going back up again to + + align:start position:0% +knowledge it is going back up again to + + + align:start position:0% +knowledge it is going back up again to +the next predicted magic number so what + + align:start position:0% +the next predicted magic number so what + + + align:start position:0% +the next predicted magic number so what +we think should be happening is + + align:start position:0% +we think should be happening is + + + align:start position:0% +we think should be happening is +half-life should be continuously going + + align:start position:0% +half-life should be continuously going + + + align:start position:0% +half-life should be continuously going +up and yeah you had a question + + align:start position:0% + + + + align:start position:0% + +well whatever you want it's gonna be it + + align:start position:0% +well whatever you want it's gonna be it + + + align:start position:0% +well whatever you want it's gonna be it +should be dense as all heck because + + align:start position:0% +should be dense as all heck because + + + align:start position:0% +should be dense as all heck because +nuclear matters quite a bit denser than + + align:start position:0% +nuclear matters quite a bit denser than + + + align:start position:0% +nuclear matters quite a bit denser than +ordinary matter and quite a bit as quite + + align:start position:0% +ordinary matter and quite a bit as quite + + + align:start position:0% +ordinary matter and quite a bit as quite +an understatement + + align:start position:0% +an understatement + + + align:start position:0% +an understatement +so what would you do with super heavy + + align:start position:0% +so what would you do with super heavy + + + align:start position:0% +so what would you do with super heavy +matter a lot of it could be used to + + align:start position:0% +matter a lot of it could be used to + + + align:start position:0% +matter a lot of it could be used to +probe the structure of matter there's a + + align:start position:0% +probe the structure of matter there's a + + + align:start position:0% +probe the structure of matter there's a +lot about how the nucleus is constructed + + align:start position:0% +lot about how the nucleus is constructed + + + align:start position:0% +lot about how the nucleus is constructed +that we don't know and beyond the scope + + align:start position:0% +that we don't know and beyond the scope + + + align:start position:0% +that we don't know and beyond the scope +of this course would also be an + + align:start position:0% +of this course would also be an + + + align:start position:0% +of this course would also be an +understatement + + align:start position:0% +understatement + + + align:start position:0% +understatement +there's folks that are making their + + align:start position:0% +there's folks that are making their + + + align:start position:0% +there's folks that are making their +careers now and figuring out what are + + align:start position:0% +careers now and figuring out what are + + + align:start position:0% +careers now and figuring out what are +the forces between nucleons why do + + align:start position:0% +the forces between nucleons why do + + + align:start position:0% +the forces between nucleons why do +things spontaneously fizz at the rates + + align:start position:0% +things spontaneously fizz at the rates + + + align:start position:0% +things spontaneously fizz at the rates +that they do you'll even hit a little + + align:start position:0% +that they do you'll even hit a little + + + align:start position:0% +that they do you'll even hit a little +bit of this in 22:02 + + align:start position:0% +bit of this in 22:02 + + + align:start position:0% +bit of this in 22:02 +when you can calculate the rough + + align:start position:0% +when you can calculate the rough + + + align:start position:0% +when you can calculate the rough +half-life for alpha decay using quantum + + align:start position:0% +half-life for alpha decay using quantum + + + align:start position:0% +half-life for alpha decay using quantum +tunneling through the potential barrier + + align:start position:0% +tunneling through the potential barrier + + + align:start position:0% +tunneling through the potential barrier +in a nucleus and so the more nuclei we + + align:start position:0% +in a nucleus and so the more nuclei we + + + align:start position:0% +in a nucleus and so the more nuclei we +have to mess around with the more data + + align:start position:0% +have to mess around with the more data + + + align:start position:0% +have to mess around with the more data +and real examples we have to study but + + align:start position:0% +and real examples we have to study but + + + align:start position:0% +and real examples we have to study but +practical applications well I could + + align:start position:0% +practical applications well I could + + + align:start position:0% +practical applications well I could +imagine we might find something denser + + align:start position:0% +imagine we might find something denser + + + align:start position:0% +imagine we might find something denser +than osmium osmium right now is a + + align:start position:0% +than osmium osmium right now is a + + + align:start position:0% +than osmium osmium right now is a +density of about 22 grams per cubic + + align:start position:0% +density of about 22 grams per cubic + + + align:start position:0% +density of about 22 grams per cubic +centimeter this stuff zirconium + + align:start position:0% +centimeter this stuff zirconium + + + align:start position:0% +centimeter this stuff zirconium +it's about 6.9 or so Steel's like eight + + align:start position:0% +it's about 6.9 or so Steel's like eight + + + align:start position:0% +it's about 6.9 or so Steel's like eight +LEDs like eleven Mercury's like nineteen + + align:start position:0% +LEDs like eleven Mercury's like nineteen + + + align:start position:0% +LEDs like eleven Mercury's like nineteen +via any of you ever played with liquid + + align:start position:0% +via any of you ever played with liquid + + + align:start position:0% +via any of you ever played with liquid +mercury before yeah this is a don't try + + align:start position:0% +mercury before yeah this is a don't try + + + align:start position:0% +mercury before yeah this is a don't try +this at home kids kind of moment my + + align:start position:0% +this at home kids kind of moment my + + + align:start position:0% +this at home kids kind of moment my +grandfather happened to be a dentist so + + align:start position:0% +grandfather happened to be a dentist so + + + align:start position:0% +grandfather happened to be a dentist so +we happen to have a lot of mercury to + + align:start position:0% +we happen to have a lot of mercury to + + + align:start position:0% +we happen to have a lot of mercury to +mess around with and it's like + + align:start position:0% +mess around with and it's like + + + align:start position:0% +mess around with and it's like +unintuitive ly heavy it's unbelievable a + + align:start position:0% +unintuitive ly heavy it's unbelievable a + + + align:start position:0% +unintuitive ly heavy it's unbelievable a +one-pound jar is about that big I think + + align:start position:0% +one-pound jar is about that big I think + + + align:start position:0% +one-pound jar is about that big I think +would be cool if we could time something + + align:start position:0% +would be cool if we could time something + + + align:start position:0% +would be cool if we could time something +even denser and then really really dense + + align:start position:0% +even denser and then really really dense + + + align:start position:0% +even denser and then really really dense +matter happens to make really really + + align:start position:0% +matter happens to make really really + + + align:start position:0% +matter happens to make really really +good photon shields gamma seen on the + + align:start position:0% +good photon shields gamma seen on the + + + align:start position:0% +good photon shields gamma seen on the +Star Trek thing I mean this in the + + align:start position:0% +Star Trek thing I mean this in the + + + align:start position:0% +Star Trek thing I mean this in the +actual nuclear physics sense is the best + + align:start position:0% +actual nuclear physics sense is the best + + + align:start position:0% +actual nuclear physics sense is the best +way to stop gamma rays for gamma + + align:start position:0% +way to stop gamma rays for gamma + + + align:start position:0% +way to stop gamma rays for gamma +shielding is just put more matter in + + align:start position:0% +shielding is just put more matter in + + + align:start position:0% +shielding is just put more matter in +front of it and if we find a denser + + align:start position:0% +front of it and if we find a denser + + + align:start position:0% +front of it and if we find a denser +state of matter that's earth stable you + + align:start position:0% +state of matter that's earth stable you + + + align:start position:0% +state of matter that's earth stable you +then have a smaller gamma shield so + + align:start position:0% +then have a smaller gamma shield so + + + align:start position:0% +then have a smaller gamma shield so +there are practical applications to in + + align:start position:0% +there are practical applications to in + + + align:start position:0% +there are practical applications to in +radiation shielding they also might make + + align:start position:0% +radiation shielding they also might make + + + align:start position:0% +radiation shielding they also might make +awesome nuclear fuel because you better + + align:start position:0% +awesome nuclear fuel because you better + + + align:start position:0% +awesome nuclear fuel because you better +believe they're gonna fizz like crazy so + + align:start position:0% +believe they're gonna fizz like crazy so + + + align:start position:0% +believe they're gonna fizz like crazy so +who knows maybe we can I don't think + + align:start position:0% +who knows maybe we can I don't think + + + align:start position:0% +who knows maybe we can I don't think +that would be cost-effective but it + + align:start position:0% +that would be cost-effective but it + + + align:start position:0% +that would be cost-effective but it +would probably work so the way they're + + align:start position:0% +would probably work so the way they're + + + align:start position:0% +would probably work so the way they're +doing this is actually slamming calcium + + align:start position:0% +doing this is actually slamming calcium + + + align:start position:0% +doing this is actually slamming calcium +48 nuclei + + align:start position:0% +48 nuclei + + + align:start position:0% +48 nuclei +into other super-heavy elements that + + align:start position:0% +into other super-heavy elements that + + + align:start position:0% +into other super-heavy elements that +have exceptionally long half-lives so if + + align:start position:0% +have exceptionally long half-lives so if + + + align:start position:0% +have exceptionally long half-lives so if +you can't read what the screen says this + + align:start position:0% +you can't read what the screen says this + + + align:start position:0% +you can't read what the screen says this +here is berkelium for berkeley with + + align:start position:0% +here is berkelium for berkeley with + + + align:start position:0% +here is berkelium for berkeley with +proton number 97 mass number 249 let's + + align:start position:0% +proton number 97 mass number 249 let's + + + align:start position:0% +proton number 97 mass number 249 let's +take a look at EK 249 which happens to + + align:start position:0% +take a look at EK 249 which happens to + + + align:start position:0% +take a look at EK 249 which happens to +be way beyond uranium so it's definitely + + align:start position:0% +be way beyond uranium so it's definitely + + + align:start position:0% +be way beyond uranium so it's definitely +not a stable isotope but it has a + + align:start position:0% +not a stable isotope but it has a + + + align:start position:0% +not a stable isotope but it has a +half-life of 320 days that means you can + + align:start position:0% +half-life of 320 days that means you can + + + align:start position:0% +half-life of 320 days that means you can +make a bunch of it chemically separated + + align:start position:0% +make a bunch of it chemically separated + + + align:start position:0% +make a bunch of it chemically separated +make it into a target and fire calcium + + align:start position:0% +make it into a target and fire calcium + + + align:start position:0% +make it into a target and fire calcium +48 nuclei into it anyone want to guess + + align:start position:0% +48 nuclei into it anyone want to guess + + + align:start position:0% +48 nuclei into it anyone want to guess +why do we use calcium 48 and I'll give + + align:start position:0% +why do we use calcium 48 and I'll give + + + align:start position:0% +why do we use calcium 48 and I'll give +you a hint and write the proton number + + align:start position:0% +you a hint and write the proton number + + + align:start position:0% +you a hint and write the proton number +for calcium the isotope that we use it's + + align:start position:0% +for calcium the isotope that we use it's + + + align:start position:0% +for calcium the isotope that we use it's +calcium 28 Coliseum 48 anyone want to + + align:start position:0% +calcium 28 Coliseum 48 anyone want to + + + align:start position:0% +calcium 28 Coliseum 48 anyone want to +take a guess why start here why not just + + align:start position:0% +take a guess why start here why not just + + + align:start position:0% +take a guess why start here why not just +smash to berkelium Xin to each other + + align:start position:0% + + + + align:start position:0% + +calcium 48 happens to be exceptionally + + align:start position:0% +calcium 48 happens to be exceptionally + + + align:start position:0% +calcium 48 happens to be exceptionally +stable because it's got two magic + + align:start position:0% +stable because it's got two magic + + + align:start position:0% +stable because it's got two magic +numbers it's proton number is twenty one + + align:start position:0% +numbers it's proton number is twenty one + + + align:start position:0% +numbers it's proton number is twenty one +of those peaks of stability and it's + + align:start position:0% +of those peaks of stability and it's + + + align:start position:0% +of those peaks of stability and it's +Neutron numbers 28 so start with + + align:start position:0% +Neutron numbers 28 so start with + + + align:start position:0% +Neutron numbers 28 so start with +something super stable something with a + + align:start position:0% +something super stable something with a + + + align:start position:0% +something super stable something with a +lot more binding energy to begin with + + align:start position:0% +lot more binding energy to begin with + + + align:start position:0% +lot more binding energy to begin with +and you maximize your chance of making + + align:start position:0% +and you maximize your chance of making + + + align:start position:0% +and you maximize your chance of making +something with more binding energy that + + align:start position:0% +something with more binding energy that + + + align:start position:0% +something with more binding energy that +won't just spontaneously disappear so + + align:start position:0% +won't just spontaneously disappear so + + + align:start position:0% +won't just spontaneously disappear so +there are reasons calcium 48 was chosen + + align:start position:0% +there are reasons calcium 48 was chosen + + + align:start position:0% +there are reasons calcium 48 was chosen +and not something heavier or lighter if + + align:start position:0% +and not something heavier or lighter if + + + align:start position:0% +and not something heavier or lighter if +we go back to that article you can see + + align:start position:0% +we go back to that article you can see + + + align:start position:0% +we go back to that article you can see +what happens here is you make some + + align:start position:0% +what happens here is you make some + + + align:start position:0% +what happens here is you make some +element 117 which has yet to be made and + + align:start position:0% +element 117 which has yet to be made and + + + align:start position:0% +element 117 which has yet to be made and +it undergoes alpha decay until it + + align:start position:0% +it undergoes alpha decay until it + + + align:start position:0% +it undergoes alpha decay until it +reaches some rather stable you know 17 + + align:start position:0% +reaches some rather stable you know 17 + + + align:start position:0% +reaches some rather stable you know 17 +seconds that's pretty exceptional and if + + align:start position:0% +seconds that's pretty exceptional and if + + + align:start position:0% +seconds that's pretty exceptional and if +you notice the trends here as you decay + + align:start position:0% +you notice the trends here as you decay + + + align:start position:0% +you notice the trends here as you decay +the alpha energy steadily goes down and + + align:start position:0% +the alpha energy steadily goes down and + + + align:start position:0% +the alpha energy steadily goes down and +the half-life steadily goes up and so + + align:start position:0% +the half-life steadily goes up and so + + + align:start position:0% +the half-life steadily goes up and so +what you do is you make an super + + align:start position:0% +what you do is you make an super + + + align:start position:0% +what you do is you make an super +super-heavy element hoping that it will + + align:start position:0% +super-heavy element hoping that it will + + + align:start position:0% +super-heavy element hoping that it will +decay and rest in one of these islands + + align:start position:0% +decay and rest in one of these islands + + + align:start position:0% +decay and rest in one of these islands +of stability beyond the magic numbers + + align:start position:0% +of stability beyond the magic numbers + + + align:start position:0% +of stability beyond the magic numbers +that we know right now which I thought + + align:start position:0% +that we know right now which I thought + + + align:start position:0% +that we know right now which I thought +this was super cool because this is + + align:start position:0% +this was super cool because this is + + + align:start position:0% +this was super cool because this is +actually how + + align:start position:0% +actually how + + + align:start position:0% +actually how +opening now like new elements are made I + + align:start position:0% +opening now like new elements are made I + + + align:start position:0% +opening now like new elements are made I +think we've been seeing one a year or so + + align:start position:0% +think we've been seeing one a year or so + + + align:start position:0% +think we've been seeing one a year or so +for the past few years on average there + + align:start position:0% +for the past few years on average there + + + align:start position:0% +for the past few years on average there +might have been a year when there was + + align:start position:0% +might have been a year when there was + + + align:start position:0% +might have been a year when there was +more than one announced recently there's + + align:start position:0% +more than one announced recently there's + + + align:start position:0% +more than one announced recently there's +only a few places in the world doing + + align:start position:0% +only a few places in the world doing + + + align:start position:0% +only a few places in the world doing +them but you can start to already with + + align:start position:0% +them but you can start to already with + + + align:start position:0% +them but you can start to already with +two weeks of 2201 you can start to get a + + align:start position:0% +two weeks of 2201 you can start to get a + + + align:start position:0% +two weeks of 2201 you can start to get a +handle for why do they use the nuclei + + align:start position:0% +handle for why do they use the nuclei + + + align:start position:0% +handle for why do they use the nuclei +they do and then what sort of things are + + align:start position:0% +they do and then what sort of things are + + + align:start position:0% +they do and then what sort of things are +you looking for decays with lower and + + align:start position:0% +you looking for decays with lower and + + + align:start position:0% +you looking for decays with lower and +lower energy mean you're already + + align:start position:0% +lower energy mean you're already + + + align:start position:0% +lower energy mean you're already +starting to gets less steep on whatever + + align:start position:0% +starting to gets less steep on whatever + + + align:start position:0% +starting to gets less steep on whatever +imaginary mass parabola don't quite know + + align:start position:0% +imaginary mass parabola don't quite know + + + align:start position:0% +imaginary mass parabola don't quite know +how to draw this one because it's beyond + + align:start position:0% +how to draw this one because it's beyond + + + align:start position:0% +how to draw this one because it's beyond +anything we know and as the half-lives + + align:start position:0% +anything we know and as the half-lives + + + align:start position:0% +anything we know and as the half-lives +keep going up you can tell that it's + + align:start position:0% +keep going up you can tell that it's + + + align:start position:0% +keep going up you can tell that it's +reaching a measure of stability however + + align:start position:0% +reaching a measure of stability however + + + align:start position:0% +reaching a measure of stability however +to get you started on the homework for + + align:start position:0% +to get you started on the homework for + + + align:start position:0% +to get you started on the homework for +the open ended problem I think I'll + + align:start position:0% +the open ended problem I think I'll + + + align:start position:0% +the open ended problem I think I'll +bring it up right now so you guys can + + align:start position:0% +bring it up right now so you guys can + + + align:start position:0% +bring it up right now so you guys can +take a look so let's go to the stellar + + align:start position:0% +take a look so let's go to the stellar + + + align:start position:0% +take a look so let's go to the stellar +site + + align:start position:0% + + + + align:start position:0% + +hopefully it doesn't call me good + + align:start position:0% + + + + align:start position:0% + +at the problem set 2 this is the way I + + align:start position:0% +at the problem set 2 this is the way I + + + align:start position:0% +at the problem set 2 this is the way I +know that everyone's seen the pset 7 + + align:start position:0% +know that everyone's seen the pset 7 + + + align:start position:0% +know that everyone's seen the pset 7 +days before it's due cuz I'm gonna put + + align:start position:0% +days before it's due cuz I'm gonna put + + + align:start position:0% +days before it's due cuz I'm gonna put +it up on the screen so you can see it + + align:start position:0% +it up on the screen so you can see it + + + align:start position:0% +it up on the screen so you can see it +all the way at the end predicting the + + align:start position:0% +all the way at the end predicting the + + + align:start position:0% +all the way at the end predicting the +island of stability does the semi + + align:start position:0% +island of stability does the semi + + + align:start position:0% +island of stability does the semi +empirical mass formula predict the + + align:start position:0% +empirical mass formula predict the + + + align:start position:0% +empirical mass formula predict the +island of stability well let's start you + + align:start position:0% +island of stability well let's start you + + + align:start position:0% +island of stability well let's start you +off with the easier part of the question + + align:start position:0% +off with the easier part of the question + + + align:start position:0% +off with the easier part of the question +which is yes or no and I'm gonna leave + + align:start position:0% +which is yes or no and I'm gonna leave + + + align:start position:0% +which is yes or no and I'm gonna leave +you to the why and the how if we graph + + align:start position:0% +you to the why and the how if we graph + + + align:start position:0% +you to the why and the how if we graph +binding energy per nucleon versus mass + + align:start position:0% +binding energy per nucleon versus mass + + + align:start position:0% +binding energy per nucleon versus mass +number the semi empirical mass formula + + align:start position:0% + + + + align:start position:0% + +predicts something like this what + + align:start position:0% +predicts something like this what + + + align:start position:0% +predicts something like this what +happens as we go beyond the realm of + + align:start position:0% +happens as we go beyond the realm of + + + align:start position:0% +happens as we go beyond the realm of +known mass numbers anyone how should I + + align:start position:0% +known mass numbers anyone how should I + + + align:start position:0% +known mass numbers anyone how should I +extend this curve + + align:start position:0% + + + + align:start position:0% + +would you say Alex just keep going yeah + + align:start position:0% +would you say Alex just keep going yeah + + + align:start position:0% +would you say Alex just keep going yeah +does this predict an island of stability + + align:start position:0% +does this predict an island of stability + + + align:start position:0% +does this predict an island of stability +I don't think so + + align:start position:0% +I don't think so + + + align:start position:0% +I don't think so +so that's one of the few questions I'm + + align:start position:0% +so that's one of the few questions I'm + + + align:start position:0% +so that's one of the few questions I'm +asking you in this homework and it's up + + align:start position:0% +asking you in this homework and it's up + + + align:start position:0% +asking you in this homework and it's up +to you guys use your creativity again + + align:start position:0% +to you guys use your creativity again + + + align:start position:0% +to you guys use your creativity again +this is an open-ended problem I'm not + + align:start position:0% +this is an open-ended problem I'm not + + + align:start position:0% +this is an open-ended problem I'm not +looking for a specific answer I want to + + align:start position:0% +looking for a specific answer I want to + + + align:start position:0% +looking for a specific answer I want to +see how you think and how you would + + align:start position:0% +see how you think and how you would + + + align:start position:0% +see how you think and how you would +change this formula to account and + + align:start position:0% +change this formula to account and + + + align:start position:0% +change this formula to account and +actually predict the island of stability + + align:start position:0% +actually predict the island of stability + + + align:start position:0% +actually predict the island of stability +while still satisfying the mostly + + align:start position:0% +while still satisfying the mostly + + + align:start position:0% +while still satisfying the mostly +correct predictions from the elements we + + align:start position:0% +correct predictions from the elements we + + + align:start position:0% +correct predictions from the elements we +know so sorry go ahead + + align:start position:0% + + + + align:start position:0% + +well yaar you're on the right track if + + align:start position:0% +well yaar you're on the right track if + + + align:start position:0% +well yaar you're on the right track if +you wanna make if you want to show + + align:start position:0% +you wanna make if you want to show + + + align:start position:0% +you wanna make if you want to show +stability you'd want it to maybe have a + + align:start position:0% +stability you'd want it to maybe have a + + + align:start position:0% +stability you'd want it to maybe have a +higher value right here higher binding + + align:start position:0% +higher value right here higher binding + + + align:start position:0% +higher value right here higher binding +energy per nucleon would correspond to a + + align:start position:0% +energy per nucleon would correspond to a + + + align:start position:0% +energy per nucleon would correspond to a +lower mass which would correspond to + + align:start position:0% +lower mass which would correspond to + + + align:start position:0% +lower mass which would correspond to +higher stability so how would you + + align:start position:0% +higher stability so how would you + + + align:start position:0% +higher stability so how would you +predict this island of stability and + + align:start position:0% +predict this island of stability and + + + align:start position:0% +predict this island of stability and +then more specifically how would you + + align:start position:0% +then more specifically how would you + + + align:start position:0% +then more specifically how would you +reconcile the misty inaccuracies in the + + align:start position:0% +reconcile the misty inaccuracies in the + + + align:start position:0% +reconcile the misty inaccuracies in the +semi empirical mass formula because we + + align:start position:0% +semi empirical mass formula because we + + + align:start position:0% +semi empirical mass formula because we +know it doesn't work very well for all + + align:start position:0% +know it doesn't work very well for all + + + align:start position:0% +know it doesn't work very well for all +cases there are some cases like right + + align:start position:0% +cases there are some cases like right + + + align:start position:0% +cases there are some cases like right +around here where it works great and + + align:start position:0% +around here where it works great and + + + align:start position:0% +around here where it works great and +there's some like right here and right + + align:start position:0% +there's some like right here and right + + + align:start position:0% +there's some like right here and right +here where it really doesn't and get + + align:start position:0% +here where it really doesn't and get + + + align:start position:0% +here where it really doesn't and get +things wrong by like ten MeV which is + + align:start position:0% +things wrong by like ten MeV which is + + + align:start position:0% +things wrong by like ten MeV which is +pretty significant you know that's like + + align:start position:0% +pretty significant you know that's like + + + align:start position:0% +pretty significant you know that's like +four digits on the mass scale like the + + align:start position:0% +four digits on the mass scale like the + + + align:start position:0% +four digits on the mass scale like the +fourth decimal place that's huge to a + + align:start position:0% +fourth decimal place that's huge to a + + + align:start position:0% +fourth decimal place that's huge to a +nuclear engineer so that's something to + + align:start position:0% +nuclear engineer so that's something to + + + align:start position:0% +nuclear engineer so that's something to +get thinking about and remember I did + + align:start position:0% +get thinking about and remember I did + + + align:start position:0% +get thinking about and remember I did +tell you that there will be some + + align:start position:0% +tell you that there will be some + + + align:start position:0% +tell you that there will be some +open-ended problems I'm gonna mark them + + align:start position:0% +open-ended problems I'm gonna mark them + + + align:start position:0% +open-ended problems I'm gonna mark them +as open-ended so you actually know we're + + align:start position:0% +as open-ended so you actually know we're + + + align:start position:0% +as open-ended so you actually know we're +not looking for a right or wrong answer + + align:start position:0% +not looking for a right or wrong answer + + + align:start position:0% +not looking for a right or wrong answer +this is one of those kinds of things + + align:start position:0% +this is one of those kinds of things + + + align:start position:0% +this is one of those kinds of things +where we want to see how you think and + + align:start position:0% +where we want to see how you think and + + + align:start position:0% +where we want to see how you think and +what do you think is missing there's + + align:start position:0% +what do you think is missing there's + + + align:start position:0% +what do you think is missing there's +other hard problems where we give you + + align:start position:0% +other hard problems where we give you + + + align:start position:0% +other hard problems where we give you +the answer because I'm not interested in + + align:start position:0% +the answer because I'm not interested in + + + align:start position:0% +the answer because I'm not interested in +you deriving some explainin expression + + align:start position:0% +you deriving some explainin expression + + + align:start position:0% +you deriving some explainin expression +and getting it right I'm interested in + + align:start position:0% +and getting it right I'm interested in + + + align:start position:0% +and getting it right I'm interested in +the derivation process what are the + + align:start position:0% +the derivation process what are the + + + align:start position:0% +the derivation process what are the +steps you choose what sort of + + align:start position:0% +steps you choose what sort of + + + align:start position:0% +steps you choose what sort of +assumptions do you make what sort of + + align:start position:0% +assumptions do you make what sort of + + + align:start position:0% +assumptions do you make what sort of +terms can you neglect and say that's in + + align:start position:0% +terms can you neglect and say that's in + + + align:start position:0% +terms can you neglect and say that's in +the ninth decimal place I'm going to + + align:start position:0% +the ninth decimal place I'm going to + + + align:start position:0% +the ninth decimal place I'm going to +forget it so in this case we give you + + align:start position:0% +forget it so in this case we give you + + + align:start position:0% +forget it so in this case we give you +the answer because we're going to grade + + align:start position:0% +the answer because we're going to grade + + + align:start position:0% +the answer because we're going to grade +you on the process + + align:start position:0% +you on the process + + + align:start position:0% +you on the process +and you can use the answer to check your + + align:start position:0% +and you can use the answer to check your + + + align:start position:0% +and you can use the answer to check your +process and see if you're on the right + + align:start position:0% +process and see if you're on the right + + + align:start position:0% +process and see if you're on the right +track or not for the skill building + + align:start position:0% +track or not for the skill building + + + align:start position:0% +track or not for the skill building +questions we actually do want you to + + align:start position:0% +questions we actually do want you to + + + align:start position:0% +questions we actually do want you to +come up with some sort of an answer like + + align:start position:0% +come up with some sort of an answer like + + + align:start position:0% +come up with some sort of an answer like +explaining the terms in the semi + + align:start position:0% +explaining the terms in the semi + + + align:start position:0% +explaining the terms in the semi +empirical mass formula or modifying an + + align:start position:0% +empirical mass formula or modifying an + + + align:start position:0% +empirical mass formula or modifying an +equation to calculate something else we + + align:start position:0% +equation to calculate something else we + + + align:start position:0% +equation to calculate something else we +will be looking for a right answer there + + align:start position:0% +will be looking for a right answer there + + + align:start position:0% +will be looking for a right answer there +but those are questions to make sure + + align:start position:0% +but those are questions to make sure + + + align:start position:0% +but those are questions to make sure +that you get the basics of the material + + align:start position:0% +that you get the basics of the material + + + align:start position:0% +that you get the basics of the material +if you can answer all of the questions + + align:start position:0% +if you can answer all of the questions + + + align:start position:0% +if you can answer all of the questions +in the first half of these P sets fairly + + align:start position:0% +in the first half of these P sets fairly + + + align:start position:0% +in the first half of these P sets fairly +quickly let's say in three or four hours + + align:start position:0% +quickly let's say in three or four hours + + + align:start position:0% +quickly let's say in three or four hours +you're totally on the right track the + + align:start position:0% +you're totally on the right track the + + + align:start position:0% +you're totally on the right track the +hard ones is because this is MIT and we + + align:start position:0% +hard ones is because this is MIT and we + + + align:start position:0% +hard ones is because this is MIT and we +want you to think beyond just knowing + + align:start position:0% +want you to think beyond just knowing + + + align:start position:0% +want you to think beyond just knowing +what's in the Turner book or the Yip + + align:start position:0% +what's in the Turner book or the Yip + + + align:start position:0% +what's in the Turner book or the Yip +book like I said you guys are the + + align:start position:0% +book like I said you guys are the + + + align:start position:0% +book like I said you guys are the +leaders of this field so any other + + align:start position:0% +leaders of this field so any other + + + align:start position:0% +leaders of this field so any other +questions on instability in general yes + + align:start position:0% + + + + align:start position:0% + +you say + + align:start position:0% +you say + + + align:start position:0% +you say +correct so that would be even N and even + + align:start position:0% +correct so that would be even N and even + + + align:start position:0% +correct so that would be even N and even +Z are on N and odd Z like in the reading + + align:start position:0% +Z are on N and odd Z like in the reading + + + align:start position:0% +Z are on N and odd Z like in the reading +and like on these mass parabolas yep any + + align:start position:0% +and like on these mass parabolas yep any + + + align:start position:0% +and like on these mass parabolas yep any +other questions yes + + align:start position:0% + + + + align:start position:0% + +there's a few roots so the question was + + align:start position:0% +there's a few roots so the question was + + + align:start position:0% +there's a few roots so the question was +is the only is the only reason people + + align:start position:0% +is the only is the only reason people + + + align:start position:0% +is the only is the only reason people +think they'll be super heavy elements + + align:start position:0% +think they'll be super heavy elements + + + align:start position:0% +think they'll be super heavy elements +because the mass increases right so in + + align:start position:0% +because the mass increases right so in + + + align:start position:0% +because the mass increases right so in +this case the the mass will always are + + align:start position:0% +this case the the mass will always are + + + align:start position:0% +this case the the mass will always are +you talking about now the total mass or + + align:start position:0% + + + + align:start position:0% + +okay we have a few things to go on so + + align:start position:0% +okay we have a few things to go on so + + + align:start position:0% +okay we have a few things to go on so +all there are a number of different + + align:start position:0% +all there are a number of different + + + align:start position:0% +all there are a number of different +aspects of nuclear stability that are + + align:start position:0% +aspects of nuclear stability that are + + + align:start position:0% +aspects of nuclear stability that are +all pointing to the same conclusion one + + align:start position:0% +all pointing to the same conclusion one + + + align:start position:0% +all pointing to the same conclusion one +of them you can see on this graph here + + align:start position:0% +of them you can see on this graph here + + + align:start position:0% +of them you can see on this graph here +if you look at the alpha decay half-life + + align:start position:0% +if you look at the alpha decay half-life + + + align:start position:0% +if you look at the alpha decay half-life +as a function of Neutron number it + + align:start position:0% +as a function of Neutron number it + + + align:start position:0% +as a function of Neutron number it +doesn't just increase or decrease + + align:start position:0% +doesn't just increase or decrease + + + align:start position:0% +doesn't just increase or decrease +monotonically it swells up and down and + + align:start position:0% +monotonically it swells up and down and + + + align:start position:0% +monotonically it swells up and down and +it reaches a relative maximum near + + align:start position:0% +it reaches a relative maximum near + + + align:start position:0% +it reaches a relative maximum near +certain magic numbers we can confirm + + align:start position:0% +certain magic numbers we can confirm + + + align:start position:0% +certain magic numbers we can confirm +that with the lower mass nuclei it + + align:start position:0% +that with the lower mass nuclei it + + + align:start position:0% +that with the lower mass nuclei it +doesn't work for really low mass because + + align:start position:0% +doesn't work for really low mass because + + + align:start position:0% +doesn't work for really low mass because +tiny things don't tend to go under + + align:start position:0% +tiny things don't tend to go under + + + align:start position:0% +tiny things don't tend to go under +undergo alpha decay but there are + + align:start position:0% +undergo alpha decay but there are + + + align:start position:0% +undergo alpha decay but there are +patterns that were simply recognizing + + align:start position:0% +patterns that were simply recognizing + + + align:start position:0% +patterns that were simply recognizing +and saying well if this is the next + + align:start position:0% +and saying well if this is the next + + + align:start position:0% +and saying well if this is the next +magic number it should continue to + + align:start position:0% +magic number it should continue to + + + align:start position:0% +magic number it should continue to +increase and I should mention to this + + align:start position:0% +increase and I should mention to this + + + align:start position:0% +increase and I should mention to this +scale is logarithmic so the top right + + align:start position:0% +scale is logarithmic so the top right + + + align:start position:0% +scale is logarithmic so the top right +here is like 10 to the 4 seconds just so + + align:start position:0% +here is like 10 to the 4 seconds just so + + + align:start position:0% +here is like 10 to the 4 seconds just so +you know there are 86,400 seconds in + + align:start position:0% +you know there are 86,400 seconds in + + + align:start position:0% +you know there are 86,400 seconds in +what is it a day and 3 times 10 to the 7 + + align:start position:0% +what is it a day and 3 times 10 to the 7 + + + align:start position:0% +what is it a day and 3 times 10 to the 7 +seconds in a year so if this graph let's + + align:start position:0% +seconds in a year so if this graph let's + + + align:start position:0% +seconds in a year so if this graph let's +say for Z 111 were to continue on its + + align:start position:0% +say for Z 111 were to continue on its + + + align:start position:0% +say for Z 111 were to continue on its +track it should reach like 10 to the 9 + + align:start position:0% +track it should reach like 10 to the 9 + + + align:start position:0% +track it should reach like 10 to the 9 +or 10 to the 10 which could be like + + align:start position:0% +or 10 to the 10 which could be like + + + align:start position:0% +or 10 to the 10 which could be like +hundred year lifetimes or 100 year + + align:start position:0% +hundred year lifetimes or 100 year + + + align:start position:0% +hundred year lifetimes or 100 year +half-lives which means definitely you + + align:start position:0% +half-lives which means definitely you + + + align:start position:0% +half-lives which means definitely you +can chemically separate them and do + + align:start position:0% +can chemically separate them and do + + + align:start position:0% +can chemically separate them and do +things with them I don't know if they + + align:start position:0% +things with them I don't know if they + + + align:start position:0% +things with them I don't know if they +would be safe enough to deal with but we + + align:start position:0% +would be safe enough to deal with but we + + + align:start position:0% +would be safe enough to deal with but we +also don't really know what's going to + + align:start position:0% +also don't really know what's going to + + + align:start position:0% +also don't really know what's going to +happen you can see that there is some + + align:start position:0% +happen you can see that there is some + + + align:start position:0% +happen you can see that there is some +uncertainty and things don't always + + align:start position:0% +uncertainty and things don't always + + + align:start position:0% +uncertainty and things don't always +follow the trend even the error bars are + + align:start position:0% +follow the trend even the error bars are + + + align:start position:0% +follow the trend even the error bars are +outside the dashed lines but so we have + + align:start position:0% +outside the dashed lines but so we have + + + align:start position:0% +outside the dashed lines but so we have +this to go on we have the alpha decay + + align:start position:0% +this to go on we have the alpha decay + + + align:start position:0% +this to go on we have the alpha decay +half-life we also have the alpha decay + + align:start position:0% +half-life we also have the alpha decay + + + align:start position:0% +half-life we also have the alpha decay +energy as you approach an island of + + align:start position:0% +energy as you approach an island of + + + align:start position:0% +energy as you approach an island of +stability something that's more stable + + align:start position:0% +stability something that's more stable + + + align:start position:0% +stability something that's more stable +won't give off as much kinetic energy to + + align:start position:0% +won't give off as much kinetic energy to + + + align:start position:0% +won't give off as much kinetic energy to +its alpha particle there's also for the + + align:start position:0% +its alpha particle there's also for the + + + align:start position:0% +its alpha particle there's also for the +ones that you can actually measure that + + align:start position:0% +ones that you can actually measure that + + + align:start position:0% +ones that you can actually measure that +live long enough you can measure their + + align:start position:0% +live long enough you can measure their + + + align:start position:0% +live long enough you can measure their +mass-to-charge ratio and actually get a + + align:start position:0% +mass-to-charge ratio and actually get a + + + align:start position:0% +mass-to-charge ratio and actually get a +good picture of their actual mass so we + + align:start position:0% +good picture of their actual mass so we + + + align:start position:0% +good picture of their actual mass so we +would expect the mass defect to follow a + + align:start position:0% +would expect the mass defect to follow a + + + align:start position:0% +would expect the mass defect to follow a +certain trend as we go up the mass is + + align:start position:0% +certain trend as we go up the mass is + + + align:start position:0% +certain trend as we go up the mass is +always going to increase if you add more + + align:start position:0% +always going to increase if you add more + + + align:start position:0% +always going to increase if you add more +nucleons it's going to increase but the + + align:start position:0% +nucleons it's going to increase but the + + + align:start position:0% +nucleons it's going to increase but the +mass defect which is the real mass minus + + align:start position:0% +mass defect which is the real mass minus + + + align:start position:0% +mass defect which is the real mass minus +the atomic number mass if stability were + + align:start position:0% +the atomic number mass if stability were + + + align:start position:0% +the atomic number mass if stability were +to increase do you think the mass defect + + align:start position:0% +to increase do you think the mass defect + + + align:start position:0% +to increase do you think the mass defect +would increase or decrease with more + + align:start position:0% +would increase or decrease with more + + + align:start position:0% +would increase or decrease with more +stability let's take a quick look at + + align:start position:0% +stability let's take a quick look at + + + align:start position:0% +stability let's take a quick look at +this if a were to stay the same a + + align:start position:0% +this if a were to stay the same a + + + align:start position:0% +this if a were to stay the same a +shrinking real mass and remember lower + + align:start position:0% +shrinking real mass and remember lower + + + align:start position:0% +shrinking real mass and remember lower +mass means more stability would mean a + + align:start position:0% +mass means more stability would mean a + + + align:start position:0% +mass means more stability would mean a +higher or a lower mass defect I mean a + + align:start position:0% +higher or a lower mass defect I mean a + + + align:start position:0% +higher or a lower mass defect I mean a +lower mass defect or a lower excess mass + + align:start position:0% +lower mass defect or a lower excess mass + + + align:start position:0% +lower mass defect or a lower excess mass +as you'd call it so in this case you + + align:start position:0% +as you'd call it so in this case you + + + align:start position:0% +as you'd call it so in this case you +would expect the mass of the nucleus to + + align:start position:0% +would expect the mass of the nucleus to + + + align:start position:0% +would expect the mass of the nucleus to +be smaller than its a if it was going + + align:start position:0% +be smaller than its a if it was going + + + align:start position:0% +be smaller than its a if it was going +more stable and all of these trends work + + align:start position:0% +more stable and all of these trends work + + + align:start position:0% +more stable and all of these trends work +in the same direction which is saying + + align:start position:0% +in the same direction which is saying + + + align:start position:0% +in the same direction which is saying +okay so we have the Alpha energy we have + + align:start position:0% +okay so we have the Alpha energy we have + + + align:start position:0% +okay so we have the Alpha energy we have +the mass defect we have the half-life + + align:start position:0% +the mass defect we have the half-life + + + align:start position:0% +the mass defect we have the half-life +all pointing to the same thing that + + align:start position:0% +all pointing to the same thing that + + + align:start position:0% +all pointing to the same thing that +something should be more stable and we + + align:start position:0% +something should be more stable and we + + + align:start position:0% +something should be more stable and we +have some patterns to go on but our + + align:start position:0% +have some patterns to go on but our + + + align:start position:0% +have some patterns to go on but our +understandings kind of incomplete so yep + + align:start position:0% + + + + align:start position:0% + +whoo good question + + align:start position:0% + + + + align:start position:0% + +so the question is if super-heavy + + align:start position:0% +so the question is if super-heavy + + + align:start position:0% +so the question is if super-heavy +elements exist do they exist out there + + align:start position:0% +elements exist do they exist out there + + + align:start position:0% +elements exist do they exist out there +in space I think there would be a couple + + align:start position:0% +in space I think there would be a couple + + + align:start position:0% +in space I think there would be a couple +places they would exist the source of + + align:start position:0% +places they would exist the source of + + + align:start position:0% +places they would exist the source of +most of the elements beyond iron is + + align:start position:0% +most of the elements beyond iron is + + + align:start position:0% +most of the elements beyond iron is +supernovas where a regular old fusion + + align:start position:0% +supernovas where a regular old fusion + + + align:start position:0% +supernovas where a regular old fusion +doesn't cut it anymore when you hit the + + align:start position:0% +doesn't cut it anymore when you hit the + + + align:start position:0% +doesn't cut it anymore when you hit the +maximum of this binding energy per + + align:start position:0% +maximum of this binding energy per + + + align:start position:0% +maximum of this binding energy per +nucleon curve you're at about iron-56 + + align:start position:0% +nucleon curve you're at about iron-56 + + + align:start position:0% +nucleon curve you're at about iron-56 +that's why stars tend to form a core of + + align:start position:0% +that's why stars tend to form a core of + + + align:start position:0% +that's why stars tend to form a core of +iron before it goes really bad in + + align:start position:0% +iron before it goes really bad in + + + align:start position:0% +iron before it goes really bad in +whatever way it does for a star there + + align:start position:0% +whatever way it does for a star there + + + align:start position:0% +whatever way it does for a star there +are multiple ways when you get a + + align:start position:0% +are multiple ways when you get a + + + align:start position:0% +are multiple ways when you get a +supernova you have an insane explosion + + align:start position:0% +supernova you have an insane explosion + + + align:start position:0% +supernova you have an insane explosion +and the core gets compressed from the + + align:start position:0% +and the core gets compressed from the + + + align:start position:0% +and the core gets compressed from the +outside + + align:start position:0% +outside + + + align:start position:0% +outside +forcing fusion of heavy elements to + + align:start position:0% +forcing fusion of heavy elements to + + + align:start position:0% +forcing fusion of heavy elements to +happen that's because you're putting in + + align:start position:0% +happen that's because you're putting in + + + align:start position:0% +happen that's because you're putting in +extra kinetic energy so it's like you + + align:start position:0% +extra kinetic energy so it's like you + + + align:start position:0% +extra kinetic energy so it's like you +have an endothermic reaction where if Q + + align:start position:0% +have an endothermic reaction where if Q + + + align:start position:0% +have an endothermic reaction where if Q +is less than zero how do you make that + + align:start position:0% +is less than zero how do you make that + + + align:start position:0% +is less than zero how do you make that +reaction happen add kinetic energy which + + align:start position:0% +reaction happen add kinetic energy which + + + align:start position:0% +reaction happen add kinetic energy which +can come from a tremendous explosion + + align:start position:0% +can come from a tremendous explosion + + + align:start position:0% +can come from a tremendous explosion +outside of the outer regions of the star + + align:start position:0% +outside of the outer regions of the star + + + align:start position:0% +outside of the outer regions of the star +so who's to say that some of these + + align:start position:0% +so who's to say that some of these + + + align:start position:0% +so who's to say that some of these +super-heavy elements aren't formed in + + align:start position:0% +super-heavy elements aren't formed in + + + align:start position:0% +super-heavy elements aren't formed in +supernovas I think they would be but + + align:start position:0% +supernovas I think they would be but + + + align:start position:0% +supernovas I think they would be but +would they actually make it out to be + + align:start position:0% +would they actually make it out to be + + + align:start position:0% +would they actually make it out to be +part of earth and then let's say live + + align:start position:0% +part of earth and then let's say live + + + align:start position:0% +part of earth and then let's say live +the five billion years that Art's been + + align:start position:0% +the five billion years that Art's been + + + align:start position:0% +the five billion years that Art's been +around we don't know if their half-lives + + align:start position:0% +around we don't know if their half-lives + + + align:start position:0% +around we don't know if their half-lives +are long enough there very well may have + + align:start position:0% +are long enough there very well may have + + + align:start position:0% +are long enough there very well may have +been some five billion years ago or when + + align:start position:0% +been some five billion years ago or when + + + align:start position:0% +been some five billion years ago or when +the supernova was made but we haven't + + align:start position:0% +the supernova was made but we haven't + + + align:start position:0% +the supernova was made but we haven't +detected any here on earth so we know + + align:start position:0% +detected any here on earth so we know + + + align:start position:0% +detected any here on earth so we know +that they're not five billion years + + align:start position:0% +that they're not five billion years + + + align:start position:0% +that they're not five billion years +stable rather I wouldn't even need to + + align:start position:0% +stable rather I wouldn't even need to + + + align:start position:0% +stable rather I wouldn't even need to +say we know that but we have a pretty + + align:start position:0% +say we know that but we have a pretty + + + align:start position:0% +say we know that but we have a pretty +good idea + + align:start position:0% +good idea + + + align:start position:0% +good idea +that's a great question is like are they + + align:start position:0% +that's a great question is like are they + + + align:start position:0% +that's a great question is like are they +naturally made probably yeah any other + + align:start position:0% +naturally made probably yeah any other + + + align:start position:0% +naturally made probably yeah any other +questions I like these outside the + + align:start position:0% +questions I like these outside the + + + align:start position:0% +questions I like these outside the +material ones we can take things beyond + + align:start position:0% +material ones we can take things beyond + + + align:start position:0% +material ones we can take things beyond +our known universe start to explain them + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/mNlOG7CFPEY.txt b/mNlOG7CFPEY.txt new file mode 100644 index 0000000000000000000000000000000000000000..45b8ca222e83685403334242222a7ee05f836339 --- /dev/null +++ b/mNlOG7CFPEY.txt @@ -0,0 +1,13635 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit MIT opencourseware + + align:start position:0% +of MIT courses visit MIT opencourseware + + + align:start position:0% +of MIT courses visit MIT opencourseware +at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu thank you for the + + align:start position:0% +ocw.mit.edu thank you for the + + + align:start position:0% +ocw.mit.edu thank you for the +introduction I'm happy to be here today + + align:start position:0% +introduction I'm happy to be here today + + + align:start position:0% +introduction I'm happy to be here today +I hear at Spring break so I'm impressed + + align:start position:0% +I hear at Spring break so I'm impressed + + + align:start position:0% +I hear at Spring break so I'm impressed +that you're all here uh it doesn't feel + + align:start position:0% +that you're all here uh it doesn't feel + + + align:start position:0% +that you're all here uh it doesn't feel +much like spring outside but I'm sure + + align:start position:0% +much like spring outside but I'm sure + + + align:start position:0% +much like spring outside but I'm sure +hopefully it will in the next couple + + align:start position:0% +hopefully it will in the next couple + + + align:start position:0% +hopefully it will in the next couple +weeks um so uh priia and I are going to + + align:start position:0% +weeks um so uh priia and I are going to + + + align:start position:0% +weeks um so uh priia and I are going to +talk a bit about uh what we've been + + align:start position:0% +talk a bit about uh what we've been + + + align:start position:0% +talk a bit about uh what we've been +working on in regards to checklist so + + align:start position:0% +working on in regards to checklist so + + + align:start position:0% +working on in regards to checklist so +it's a little bit uh I think it's a + + align:start position:0% +it's a little bit uh I think it's a + + + align:start position:0% +it's a little bit uh I think it's a +little bit different from some of the + + align:start position:0% +little bit different from some of the + + + align:start position:0% +little bit different from some of the +technology discussions you've have in + + align:start position:0% +technology discussions you've have in + + + align:start position:0% +technology discussions you've have in +the past but I think the similarity is + + align:start position:0% +the past but I think the similarity is + + + align:start position:0% +the past but I think the similarity is +in that we bring uh the idea of bringing + + align:start position:0% +in that we bring uh the idea of bringing + + + align:start position:0% +in that we bring uh the idea of bringing +Innovations and also implementing + + align:start position:0% +Innovations and also implementing + + + align:start position:0% +Innovations and also implementing +Innovations in poor areas and so I want + + align:start position:0% +Innovations in poor areas and so I want + + + align:start position:0% +Innovations in poor areas and so I want +to start off by just giving a brief + + align:start position:0% +to start off by just giving a brief + + + align:start position:0% +to start off by just giving a brief +story so uh about a month ago I went to + + align:start position:0% +story so uh about a month ago I went to + + + align:start position:0% +story so uh about a month ago I went to +Zambia we we one of our pilot sites is + + align:start position:0% +Zambia we we one of our pilot sites is + + + align:start position:0% +Zambia we we one of our pilot sites is +in Zambia and as we were flying to + + align:start position:0% +in Zambia and as we were flying to + + + align:start position:0% +in Zambia and as we were flying to +Zambia we stopped through Washington DC + + align:start position:0% +Zambia we stopped through Washington DC + + + align:start position:0% +Zambia we stopped through Washington DC +and um as we were coming down to the + + align:start position:0% +and um as we were coming down to the + + + align:start position:0% +and um as we were coming down to the +runway could watch the runway everything + + align:start position:0% +runway could watch the runway everything + + + align:start position:0% +runway could watch the runway everything +was going very well and right before we + + align:start position:0% +was going very well and right before we + + + align:start position:0% +was going very well and right before we +were about to land we took off again as + + align:start position:0% +were about to land we took off again as + + + align:start position:0% +were about to land we took off again as +we were going up we turned sharply to + + align:start position:0% +we were going up we turned sharply to + + + align:start position:0% +we were going up we turned sharply to +the left and then we just hit a whole + + align:start position:0% +the left and then we just hit a whole + + + align:start position:0% +the left and then we just hit a whole +bunch of turbulence we started the + + align:start position:0% +bunch of turbulence we started the + + + align:start position:0% +bunch of turbulence we started the +person next to me actually threw up I + + align:start position:0% +person next to me actually threw up I + + + align:start position:0% +person next to me actually threw up I +almost thought I was going to throw up + + align:start position:0% +almost thought I was going to throw up + + + align:start position:0% +almost thought I was going to throw up +uh uh despite all that we started making + + align:start position:0% +uh uh despite all that we started making + + + align:start position:0% +uh uh despite all that we started making +another approach to the to the runway as + + align:start position:0% +another approach to the to the runway as + + + align:start position:0% +another approach to the to the runway as +we were coming down to the runway uh we + + align:start position:0% +we were coming down to the runway uh we + + + align:start position:0% +we were coming down to the runway uh we +made another sharp turn to the left and + + align:start position:0% +made another sharp turn to the left and + + + align:start position:0% +made another sharp turn to the left and +then landed and as we were landing + + align:start position:0% +then landed and as we were landing + + + align:start position:0% +then landed and as we were landing +outside our window we saw these fire + + align:start position:0% +outside our window we saw these fire + + + align:start position:0% +outside our window we saw these fire +trucks kind of lined up right along the + + align:start position:0% +trucks kind of lined up right along the + + + align:start position:0% +trucks kind of lined up right along the +side of the runway and so uh following + + align:start position:0% +side of the runway and so uh following + + + align:start position:0% +side of the runway and so uh following +that the the captain got on the intercom + + align:start position:0% +that the the captain got on the intercom + + + align:start position:0% +that the the captain got on the intercom +and said sorry we had this disruption we + + align:start position:0% +and said sorry we had this disruption we + + + align:start position:0% +and said sorry we had this disruption we +had some trouble with our landing gear + + align:start position:0% +had some trouble with our landing gear + + + align:start position:0% +had some trouble with our landing gear +uh but we used our checklists and + + align:start position:0% +uh but we used our checklists and + + + align:start position:0% +uh but we used our checklists and +everything was fine everything was safe + + align:start position:0% +everything was fine everything was safe + + + align:start position:0% +everything was fine everything was safe +and so uh I give that story because + + align:start position:0% +and so uh I give that story because + + + align:start position:0% +and so uh I give that story because +checklists began kind of being used for + + align:start position:0% +checklists began kind of being used for + + + align:start position:0% +checklists began kind of being used for +safety in the aviation industry so if + + align:start position:0% +safety in the aviation industry so if + + + align:start position:0% +safety in the aviation industry so if +you go back several decades before um + + align:start position:0% +you go back several decades before um + + + align:start position:0% +you go back several decades before um +Pilots were noticing that they were + + align:start position:0% +Pilots were noticing that they were + + + align:start position:0% +Pilots were noticing that they were +involved with very risk a very risky and + + align:start position:0% +involved with very risk a very risky and + + + align:start position:0% +involved with very risk a very risky and +very complex um system and a complex + + align:start position:0% +very complex um system and a complex + + + align:start position:0% +very complex um system and a complex +procedure that had very little margin + + align:start position:0% +procedure that had very little margin + + + align:start position:0% +procedure that had very little margin +for error and for that reason they + + align:start position:0% +for error and for that reason they + + + align:start position:0% +for error and for that reason they +developed these checklists to help not + + align:start position:0% +developed these checklists to help not + + + align:start position:0% +developed these checklists to help not +only remind them but also to help them + + align:start position:0% +only remind them but also to help them + + + align:start position:0% +only remind them but also to help them +use uh tools that may not be um may not + + align:start position:0% +use uh tools that may not be um may not + + + align:start position:0% +use uh tools that may not be um may not +be found used very frequently and so + + align:start position:0% +be found used very frequently and so + + + align:start position:0% +be found used very frequently and so +that we see that in surgery as well if + + align:start position:0% +that we see that in surgery as well if + + + align:start position:0% +that we see that in surgery as well if +you think of a surgical procedure it's + + align:start position:0% +you think of a surgical procedure it's + + + align:start position:0% +you think of a surgical procedure it's +very complex you have very many + + align:start position:0% +very complex you have very many + + + align:start position:0% +very complex you have very many +different procedures uh very me very + + align:start position:0% +different procedures uh very me very + + + align:start position:0% +different procedures uh very me very +different steps throughout that uh but + + align:start position:0% +different steps throughout that uh but + + + align:start position:0% +different steps throughout that uh but +the commonality throughout the whole + + align:start position:0% +the commonality throughout the whole + + + align:start position:0% +the commonality throughout the whole +thing is there's a lot of risk involved + + align:start position:0% +thing is there's a lot of risk involved + + + align:start position:0% +thing is there's a lot of risk involved +with with + + align:start position:0% +with with + + + align:start position:0% +with with +operating and so some might say it's not + + align:start position:0% +operating and so some might say it's not + + + align:start position:0% +operating and so some might say it's not +as difficult as Landing a plane in the + + align:start position:0% +as difficult as Landing a plane in the + + + align:start position:0% +as difficult as Landing a plane in the +Hudson but I think it probably is just + + align:start position:0% +Hudson but I think it probably is just + + + align:start position:0% +Hudson but I think it probably is just +as difficult and so I wanted to start + + align:start position:0% +as difficult and so I wanted to start + + + align:start position:0% +as difficult and so I wanted to start +off give you a little background about + + align:start position:0% +off give you a little background about + + + align:start position:0% +off give you a little background about +what the safe surgery checklist is all + + align:start position:0% +what the safe surgery checklist is all + + + align:start position:0% +what the safe surgery checklist is all +about so a couple years ago the who uh + + align:start position:0% +about so a couple years ago the who uh + + + align:start position:0% +about so a couple years ago the who uh +was considering kind of its aims and in + + align:start position:0% +was considering kind of its aims and in + + + align:start position:0% +was considering kind of its aims and in +considering uh different diseases in the + + align:start position:0% +considering uh different diseases in the + + + align:start position:0% +considering uh different diseases in the +world and so as they took a look at + + align:start position:0% +world and so as they took a look at + + + align:start position:0% +world and so as they took a look at +surgery they found that surgery was + + align:start position:0% +surgery they found that surgery was + + + align:start position:0% +surgery they found that surgery was +actually very prevalent in the in the + + align:start position:0% +actually very prevalent in the in the + + + align:start position:0% +actually very prevalent in the in the +world uh it's estimated about 234 + + align:start position:0% +world uh it's estimated about 234 + + + align:start position:0% +world uh it's estimated about 234 +million procedures are done a year and + + align:start position:0% +million procedures are done a year and + + + align:start position:0% +million procedures are done a year and +this outnumbers the am the number of + + align:start position:0% +this outnumbers the am the number of + + + align:start position:0% +this outnumbers the am the number of +child births as well as a number of new + + align:start position:0% +child births as well as a number of new + + + align:start position:0% +child births as well as a number of new +HIV cases a year and so as a result this + + align:start position:0% +HIV cases a year and so as a result this + + + align:start position:0% +HIV cases a year and so as a result this +focus in looking at surgery developed + + align:start position:0% +focus in looking at surgery developed + + + align:start position:0% +focus in looking at surgery developed +and during this time it was also noted + + align:start position:0% +and during this time it was also noted + + + align:start position:0% +and during this time it was also noted +that a lot of complications that arise + + align:start position:0% +that a lot of complications that arise + + + align:start position:0% +that a lot of complications that arise +from surgery um there were a lot of + + align:start position:0% +from surgery um there were a lot of + + + align:start position:0% +from surgery um there were a lot of +complications that AR Rose from surgery + + align:start position:0% +complications that AR Rose from surgery + + + align:start position:0% +complications that AR Rose from surgery +and in addition to that many of these + + align:start position:0% +and in addition to that many of these + + + align:start position:0% +and in addition to that many of these +were preventable so it's estimated about + + align:start position:0% +were preventable so it's estimated about + + + align:start position:0% +were preventable so it's estimated about +7 million disabling complications were + + align:start position:0% +7 million disabling complications were + + + align:start position:0% +7 million disabling complications were +wi occur a year and in addition to that + + align:start position:0% +wi occur a year and in addition to that + + + align:start position:0% +wi occur a year and in addition to that +about a million of those complications + + align:start position:0% +about a million of those complications + + + align:start position:0% +about a million of those complications +result in death and so that's a lot of + + align:start position:0% +result in death and so that's a lot of + + + align:start position:0% +result in death and so that's a lot of +death that's a lot of + + align:start position:0% +death that's a lot of + + + align:start position:0% +death that's a lot of +complications uh if you look at these + + align:start position:0% +complications uh if you look at these + + + align:start position:0% +complications uh if you look at these +complications it was also ES about 50% + + align:start position:0% +complications it was also ES about 50% + + + align:start position:0% +complications it was also ES about 50% +of these complications were preventable + + align:start position:0% +of these complications were preventable + + + align:start position:0% +of these complications were preventable +uh if you think about wrong site surgery + + align:start position:0% +uh if you think about wrong site surgery + + + align:start position:0% +uh if you think about wrong site surgery +you think well that seems very how could + + align:start position:0% +you think well that seems very how could + + + align:start position:0% +you think well that seems very how could +that ever happened but it's estimated + + align:start position:0% +that ever happened but it's estimated + + + align:start position:0% +that ever happened but it's estimated +about 1500 + + align:start position:0% +about 1500 + + + align:start position:0% +about 1500 +2500 cases of wrong site surgery + + align:start position:0% +2500 cases of wrong site surgery + + + align:start position:0% +2500 cases of wrong site surgery +happened a year in fact my + + align:start position:0% +happened a year in fact my + + + align:start position:0% +happened a year in fact my +grandmother-in-law I guess you'd say uh + + align:start position:0% +grandmother-in-law I guess you'd say uh + + + align:start position:0% +grandmother-in-law I guess you'd say uh +was having carpal tunnel surgery maybe + + align:start position:0% +was having carpal tunnel surgery maybe + + + align:start position:0% +was having carpal tunnel surgery maybe +about five years ago and they actually + + align:start position:0% +about five years ago and they actually + + + align:start position:0% +about five years ago and they actually +did it on the wrong hand wrong wrist and + + align:start position:0% +did it on the wrong hand wrong wrist and + + + align:start position:0% +did it on the wrong hand wrong wrist and +nothing bad happened to her you know it + + align:start position:0% +nothing bad happened to her you know it + + + align:start position:0% +nothing bad happened to her you know it +was she was fine but at the same time it + + align:start position:0% +was she was fine but at the same time it + + + align:start position:0% +was she was fine but at the same time it +required her to go back to surgery again + + align:start position:0% +required her to go back to surgery again + + + align:start position:0% +required her to go back to surgery again +it was embarrassment for the surgeon + + align:start position:0% +it was embarrassment for the surgeon + + + align:start position:0% +it was embarrassment for the surgeon +embarrassment for everyone involved in + + align:start position:0% +embarrassment for everyone involved in + + + align:start position:0% +embarrassment for everyone involved in +addition that was was costly and so + + align:start position:0% +addition that was was costly and so + + + align:start position:0% +addition that was was costly and so +these things happen uh they're not they + + align:start position:0% +these things happen uh they're not they + + + align:start position:0% +these things happen uh they're not they +they're infrequent but they + + align:start position:0% +they're infrequent but they + + + align:start position:0% +they're infrequent but they +happen uh in addition to that if you uh + + align:start position:0% +happen uh in addition to that if you uh + + + align:start position:0% +happen uh in addition to that if you uh +consider essential modering in the + + align:start position:0% +consider essential modering in the + + + align:start position:0% +consider essential modering in the +operating rooms it's estimated that + + align:start position:0% +operating rooms it's estimated that + + + align:start position:0% +operating rooms it's estimated that +about 82% of incidents that occur in + + align:start position:0% +about 82% of incidents that occur in + + + align:start position:0% +about 82% of incidents that occur in +anesthesia can be prevented by having + + align:start position:0% +anesthesia can be prevented by having + + + align:start position:0% +anesthesia can be prevented by having +just basic monitoring systems for + + align:start position:0% +just basic monitoring systems for + + + align:start position:0% +just basic monitoring systems for +example kgs uh blood pressure monitoring + + align:start position:0% +example kgs uh blood pressure monitoring + + + align:start position:0% +example kgs uh blood pressure monitoring +or oxygen monitoring uh antibiotics + + align:start position:0% +or oxygen monitoring uh antibiotics + + + align:start position:0% +or oxygen monitoring uh antibiotics +which also are very uh not very commonly + + align:start position:0% +which also are very uh not very commonly + + + align:start position:0% +which also are very uh not very commonly +used in the developing world uh it's + + align:start position:0% +used in the developing world uh it's + + + align:start position:0% +used in the developing world uh it's +been shown that if antibo are given + + align:start position:0% +been shown that if antibo are given + + + align:start position:0% +been shown that if antibo are given +within an hour of the incision you can + + align:start position:0% +within an hour of the incision you can + + + align:start position:0% +within an hour of the incision you can +reduce the rate of surgical in infection + + align:start position:0% +reduce the rate of surgical in infection + + + align:start position:0% +reduce the rate of surgical in infection +Risk by about + + align:start position:0% +Risk by about + + + align:start position:0% +Risk by about +50% and so one of the things that we've + + align:start position:0% +50% and so one of the things that we've + + + align:start position:0% +50% and so one of the things that we've +we came to think of is that uh really in + + align:start position:0% +we came to think of is that uh really in + + + align:start position:0% +we came to think of is that uh really in +hospitals currently hospitals do most of + + align:start position:0% +hospitals currently hospitals do most of + + + align:start position:0% +hospitals currently hospitals do most of +the things most of the right things most + + align:start position:0% +the things most of the right things most + + + align:start position:0% +the things most of the right things most +of the time for most of their patients + + align:start position:0% +of the time for most of their patients + + + align:start position:0% +of the time for most of their patients +but what we were trying to do was find a + + align:start position:0% +but what we were trying to do was find a + + + align:start position:0% +but what we were trying to do was find a +way in which we can uh + + align:start position:0% +way in which we can uh + + + align:start position:0% +way in which we can uh +help uh hospitals and help providers do + + align:start position:0% +help uh hospitals and help providers do + + + align:start position:0% +help uh hospitals and help providers do +all the things all the right things to + + align:start position:0% +all the things all the right things to + + + align:start position:0% +all the things all the right things to +all their patients all the time and so + + align:start position:0% +all their patients all the time and so + + + align:start position:0% +all their patients all the time and so +that's where checklist came the idea for + + align:start position:0% +that's where checklist came the idea for + + + align:start position:0% +that's where checklist came the idea for +developing a checklist + + align:start position:0% +developing a checklist + + + align:start position:0% +developing a checklist +came and so what I'd like to talk about + + align:start position:0% +came and so what I'd like to talk about + + + align:start position:0% +came and so what I'd like to talk about +today is talk about firstly the surgical + + align:start position:0% +today is talk about firstly the surgical + + + align:start position:0% +today is talk about firstly the surgical +safety checklist and the pilot study + + align:start position:0% +safety checklist and the pilot study + + + align:start position:0% +safety checklist and the pilot study +associated with that that was published + + align:start position:0% +associated with that that was published + + + align:start position:0% +associated with that that was published +back in 2009 and then talk about what + + align:start position:0% +back in 2009 and then talk about what + + + align:start position:0% +back in 2009 and then talk about what +I've been working with directly is + + align:start position:0% +I've been working with directly is + + + align:start position:0% +I've been working with directly is +looking at the surgical safety checklist + + align:start position:0% +looking at the surgical safety checklist + + + align:start position:0% +looking at the surgical safety checklist +imp pulse o symmetry in resource limited + + align:start position:0% +imp pulse o symmetry in resource limited + + + align:start position:0% +imp pulse o symmetry in resource limited +areas and so anyone has anyone here does + + align:start position:0% +areas and so anyone has anyone here does + + + align:start position:0% +areas and so anyone has anyone here does +anyone here a physician we ask the + + align:start position:0% +anyone here a physician we ask the + + + align:start position:0% +anyone here a physician we ask the +Physicians to raise their hands Okay so + + align:start position:0% +Physicians to raise their hands Okay so + + + align:start position:0% +Physicians to raise their hands Okay so +we've got a couple anyone here a + + align:start position:0% +we've got a couple anyone here a + + + align:start position:0% +we've got a couple anyone here a +surgeon okay anyone here ever been opera + + align:start position:0% +surgeon okay anyone here ever been opera + + + align:start position:0% +surgeon okay anyone here ever been opera +on Okay so we've got a lot of people + + align:start position:0% +on Okay so we've got a lot of people + + + align:start position:0% +on Okay so we've got a lot of people +who've been opera on so I'm going to + + align:start position:0% +who've been opera on so I'm going to + + + align:start position:0% +who've been opera on so I'm going to +bring you into the operating room so + + align:start position:0% +bring you into the operating room so + + + align:start position:0% +bring you into the operating room so +this is a little glamorous here this is + + align:start position:0% +this is a little glamorous here this is + + + align:start position:0% +this is a little glamorous here this is +a this is as you recognize ER so this is + + align:start position:0% +a this is as you recognize ER so this is + + + align:start position:0% +a this is as you recognize ER so this is +one of the nicer uh operating rooms in + + align:start position:0% +one of the nicer uh operating rooms in + + + align:start position:0% +one of the nicer uh operating rooms in +the world but I just want you to I just + + align:start position:0% +the world but I just want you to I just + + + align:start position:0% +the world but I just want you to I just +want you to take a look at what's going + + align:start position:0% +want you to take a look at what's going + + + align:start position:0% +want you to take a look at what's going +on here and so to preface this this is + + align:start position:0% +on here and so to preface this this is + + + align:start position:0% +on here and so to preface this this is +uh a kidney transplant uh I believe + + align:start position:0% +uh a kidney transplant uh I believe + + + align:start position:0% +uh a kidney transplant uh I believe +Carter is undergoing a kidney transplant + + align:start position:0% +Carter is undergoing a kidney transplant + + + align:start position:0% +Carter is undergoing a kidney transplant +and so they're using the surgical safety + + align:start position:0% +and so they're using the surgical safety + + + align:start position:0% +and so they're using the surgical safety +checklist so this is an opportunity for + + align:start position:0% +checklist so this is an opportunity for + + + align:start position:0% +checklist so this is an opportunity for +you to be exposed to it then afterwards + + align:start position:0% +you to be exposed to it then afterwards + + + align:start position:0% +you to be exposed to it then afterwards +I'll talk a little bit about different + + align:start position:0% +I'll talk a little bit about different + + + align:start position:0% +I'll talk a little bit about different +parts of it and how it + + align:start position:0% + + + + align:start position:0% + +works that's not too far from what + + align:start position:0% +works that's not too far from what + + + align:start position:0% +works that's not too far from what +happens in the operating room I don't + + align:start position:0% +happens in the operating room I don't + + + align:start position:0% +happens in the operating room I don't +know if any as we mentioned before some + + align:start position:0% +know if any as we mentioned before some + + + align:start position:0% +know if any as we mentioned before some +of you have uh been in medicine but they + + align:start position:0% +of you have uh been in medicine but they + + + align:start position:0% +of you have uh been in medicine but they +operate in theaters surgeons can often + + align:start position:0% +operate in theaters surgeons can often + + + align:start position:0% +operate in theaters surgeons can often +be very um pushy there is often a very + + align:start position:0% +be very um pushy there is often a very + + + align:start position:0% +be very um pushy there is often a very +strict hierarchy you know the the the + + align:start position:0% +strict hierarchy you know the the the + + + align:start position:0% +strict hierarchy you know the the the +the attending surgeon is basically in + + align:start position:0% +the attending surgeon is basically in + + + align:start position:0% +the attending surgeon is basically in +command of the whole operating theater + + align:start position:0% +command of the whole operating theater + + + align:start position:0% +command of the whole operating theater +people as the interns or the nurses may + + align:start position:0% +people as the interns or the nurses may + + + align:start position:0% +people as the interns or the nurses may +have difficult time speaking up so these + + align:start position:0% +have difficult time speaking up so these + + + align:start position:0% +have difficult time speaking up so these +are some of the challenges that happen + + align:start position:0% +are some of the challenges that happen + + + align:start position:0% +are some of the challenges that happen +here so I want to open up to you all + + align:start position:0% +here so I want to open up to you all + + + align:start position:0% +here so I want to open up to you all +what do you + + align:start position:0% +what do you + + + align:start position:0% +what do you +think what are you what are your + + align:start position:0% +think what are you what are your + + + align:start position:0% +think what are you what are your +thoughts about what what happened here + + align:start position:0% + + + + align:start position:0% + +I was glad I wasn't the + + align:start position:0% +I was glad I wasn't the + + + align:start position:0% +I was glad I wasn't the +patient okay + + align:start position:0% +patient okay + + + align:start position:0% +patient okay +why because when I saw you know people + + align:start position:0% +why because when I saw you know people + + + align:start position:0% +why because when I saw you know people +arguing and fighting you know to nervous + + align:start position:0% +arguing and fighting you know to nervous + + + align:start position:0% +arguing and fighting you know to nervous +right can you imagine an environment + + align:start position:0% +right can you imagine an environment + + + align:start position:0% +right can you imagine an environment +where these people are are working + + align:start position:0% +where these people are are working + + + align:start position:0% +where these people are are working +together but not really getting along + + align:start position:0% +together but not really getting along + + + align:start position:0% +together but not really getting along +you think they can really work together + + align:start position:0% +you think they can really work together + + + align:start position:0% +you think they can really work together +very well probably + + align:start position:0% +very well probably + + + align:start position:0% +very well probably +not any other + + align:start position:0% + + + + align:start position:0% + +thoughts so I'll I'll start off with a + + align:start position:0% +thoughts so I'll I'll start off with a + + + align:start position:0% +thoughts so I'll I'll start off with a +couple so there are a couple points so + + align:start position:0% +couple so there are a couple points so + + + align:start position:0% +couple so there are a couple points so +one of the the hopes through development + + align:start position:0% +one of the the hopes through development + + + align:start position:0% +one of the the hopes through development +of this checklist was that was to help + + align:start position:0% +of this checklist was that was to help + + + align:start position:0% +of this checklist was that was to help +improve teamwork or communication in the + + align:start position:0% +improve teamwork or communication in the + + + align:start position:0% +improve teamwork or communication in the +operating room and so um you know the + + align:start position:0% +operating room and so um you know the + + + align:start position:0% +operating room and so um you know the +the the introduction of the different + + align:start position:0% +the the introduction of the different + + + align:start position:0% +the the introduction of the different +team members uh that was important so + + align:start position:0% +team members uh that was important so + + + align:start position:0% +team members uh that was important so +that everyone knew who was in the in the + + align:start position:0% +that everyone knew who was in the in the + + + align:start position:0% +that everyone knew who was in the in the +operating room uh there were also + + align:start position:0% +operating room uh there were also + + + align:start position:0% +operating room uh there were also +discussion we'll go I'll show you the + + align:start position:0% +discussion we'll go I'll show you the + + + align:start position:0% +discussion we'll go I'll show you the +checklist later but there are also + + align:start position:0% +checklist later but there are also + + + align:start position:0% +checklist later but there are also +points there that talk about sharing + + align:start position:0% +points there that talk about sharing + + + align:start position:0% +points there that talk about sharing +information about what were the + + align:start position:0% +information about what were the + + + align:start position:0% +information about what were the +important or critical events to + + align:start position:0% +important or critical events to + + + align:start position:0% +important or critical events to +anticipate you heard uh Dr Bon talked + + align:start position:0% +anticipate you heard uh Dr Bon talked + + + align:start position:0% +anticipate you heard uh Dr Bon talked +about the blood loss how much blood loss + + align:start position:0% +about the blood loss how much blood loss + + + align:start position:0% +about the blood loss how much blood loss +what kind of supplies are needed all + + align:start position:0% +what kind of supplies are needed all + + + align:start position:0% +what kind of supplies are needed all +these things are meant to improve the + + align:start position:0% +these things are meant to improve the + + + align:start position:0% +these things are meant to improve the +communication so that events like this + + align:start position:0% +communication so that events like this + + + align:start position:0% +communication so that events like this +even though they may be rare that they + + align:start position:0% +even though they may be rare that they + + + align:start position:0% +even though they may be rare that they +can be prepared for um so communication + + align:start position:0% +can be prepared for um so communication + + + align:start position:0% +can be prepared for um so communication +teamwork also other things such as + + align:start position:0% +teamwork also other things such as + + + align:start position:0% +teamwork also other things such as +standards of care so places such as this + + align:start position:0% +standards of care so places such as this + + + align:start position:0% +standards of care so places such as this +uh pulse oximeters or oxygen monitoring + + align:start position:0% +uh pulse oximeters or oxygen monitoring + + + align:start position:0% +uh pulse oximeters or oxygen monitoring +is always literally always present but + + align:start position:0% +is always literally always present but + + + align:start position:0% +is always literally always present but +other places that we'll talk about later + + align:start position:0% +other places that we'll talk about later + + + align:start position:0% +other places that we'll talk about later +on they're not very common and so having + + align:start position:0% +on they're not very common and so having + + + align:start position:0% +on they're not very common and so having +them available was another point of this + + align:start position:0% +them available was another point of this + + + align:start position:0% +them available was another point of this +checklist for The Who to say these are + + align:start position:0% +checklist for The Who to say these are + + + align:start position:0% +checklist for The Who to say these are +standards that we would like + + align:start position:0% +standards that we would like + + + align:start position:0% +standards that we would like +internationally for people to to make uh + + align:start position:0% +internationally for people to to make uh + + + align:start position:0% +internationally for people to to make uh +their own is there a comment over here + + align:start position:0% +their own is there a comment over here + + + align:start position:0% +their own is there a comment over here +anyone + + align:start position:0% +anyone + + + align:start position:0% +anyone +else okay so this is a little dramatic + + align:start position:0% +else okay so this is a little dramatic + + + align:start position:0% +else okay so this is a little dramatic +but you know here because they had the + + align:start position:0% +but you know here because they had the + + + align:start position:0% +but you know here because they had the +reperfusion solution they were able to + + align:start position:0% +reperfusion solution they were able to + + + align:start position:0% +reperfusion solution they were able to +help preserve that kidney and they were + + align:start position:0% +help preserve that kidney and they were + + + align:start position:0% +help preserve that kidney and they were +able to flush it with a reperfusion + + align:start position:0% +able to flush it with a reperfusion + + + align:start position:0% +able to flush it with a reperfusion +solution and reimplant the kidney so um + + align:start position:0% +solution and reimplant the kidney so um + + + align:start position:0% +solution and reimplant the kidney so um +sure had the append last summer really + + align:start position:0% +sure had the append last summer really + + + align:start position:0% +sure had the append last summer really +in a one of the hospital yeah and uh + + align:start position:0% +in a one of the hospital yeah and uh + + + align:start position:0% +in a one of the hospital yeah and uh +they all got up befor hand checklist + + align:start position:0% +they all got up befor hand checklist + + + align:start position:0% +they all got up befor hand checklist +they bow to the checklist + + align:start position:0% +they bow to the checklist + + + align:start position:0% +they bow to the checklist +great that's very good yeah you know + + align:start position:0% +great that's very good yeah you know + + + align:start position:0% +great that's very good yeah you know +it's uh we'll talk about this a little + + align:start position:0% +it's uh we'll talk about this a little + + + align:start position:0% +it's uh we'll talk about this a little +later this the checklist is not uh a + + align:start position:0% +later this the checklist is not uh a + + + align:start position:0% +later this the checklist is not uh a +huge Technologic Innovation it's + + align:start position:0% +huge Technologic Innovation it's + + + align:start position:0% +huge Technologic Innovation it's +something that people have been using + + align:start position:0% +something that people have been using + + + align:start position:0% +something that people have been using +checklist in their mind for hundreds of + + align:start position:0% +checklist in their mind for hundreds of + + + align:start position:0% +checklist in their mind for hundreds of +years but it's really the formalization + + align:start position:0% +years but it's really the formalization + + + align:start position:0% +years but it's really the formalization +of the checklist and some uh a lot of + + align:start position:0% +of the checklist and some uh a lot of + + + align:start position:0% +of the checklist and some uh a lot of +thinking put into what items going to + + align:start position:0% +thinking put into what items going to + + + align:start position:0% +thinking put into what items going to +the checklist that's really been + + align:start position:0% +the checklist that's really been + + + align:start position:0% +the checklist that's really been +somewhat novel here so this is a this is + + align:start position:0% +somewhat novel here so this is a this is + + + align:start position:0% +somewhat novel here so this is a this is +a picture of the surgical safety + + align:start position:0% +a picture of the surgical safety + + + align:start position:0% +a picture of the surgical safety +checklist as it stands uh I think it's a + + align:start position:0% +checklist as it stands uh I think it's a + + + align:start position:0% +checklist as it stands uh I think it's a +second version that the who has + + align:start position:0% +second version that the who has + + + align:start position:0% +second version that the who has +published and so it really is made up of + + align:start position:0% +published and so it really is made up of + + + align:start position:0% +published and so it really is made up of +three different portions there's uh + + align:start position:0% +three different portions there's uh + + + align:start position:0% +three different portions there's uh +they're called pause points so the first + + align:start position:0% +they're called pause points so the first + + + align:start position:0% +they're called pause points so the first +pause point is before the patient goes + + align:start position:0% +pause point is before the patient goes + + + align:start position:0% +pause point is before the patient goes +to sleep or before the induction of + + align:start position:0% +to sleep or before the induction of + + + align:start position:0% +to sleep or before the induction of +anesthesia the second pause point is + + align:start position:0% +anesthesia the second pause point is + + + align:start position:0% +anesthesia the second pause point is +before the incision of skin and the + + align:start position:0% +before the incision of skin and the + + + align:start position:0% +before the incision of skin and the +third pause point is right before the + + align:start position:0% +third pause point is right before the + + + align:start position:0% +third pause point is right before the +patient leaves a room and so these were + + align:start position:0% +patient leaves a room and so these were + + + align:start position:0% +patient leaves a room and so these were +thought to be three critical points + + align:start position:0% +thought to be three critical points + + + align:start position:0% +thought to be three critical points +points in the operation where we could + + align:start position:0% +points in the operation where we could + + + align:start position:0% +points in the operation where we could +have time to stop and also where if we + + align:start position:0% +have time to stop and also where if we + + + align:start position:0% +have time to stop and also where if we +pause to do these things we could + + align:start position:0% +pause to do these things we could + + + align:start position:0% +pause to do these things we could +prevent + + align:start position:0% +prevent + + + align:start position:0% +prevent +complications uh if you go through here + + align:start position:0% +complications uh if you go through here + + + align:start position:0% +complications uh if you go through here +um the the checklist is to be meant is + + align:start position:0% +um the the checklist is to be meant is + + + align:start position:0% +um the the checklist is to be meant is +meant to be used by all members of the + + align:start position:0% +meant to be used by all members of the + + + align:start position:0% +meant to be used by all members of the +team surgeons and anesthetists as well + + align:start position:0% +team surgeons and anesthetists as well + + + align:start position:0% +team surgeons and anesthetists as well +as nurses and so uh there are different + + align:start position:0% +as nurses and so uh there are different + + + align:start position:0% +as nurses and so uh there are different +portions that kind of focus on different + + align:start position:0% +portions that kind of focus on different + + + align:start position:0% +portions that kind of focus on different +groups but in general all portions can + + align:start position:0% +groups but in general all portions can + + + align:start position:0% +groups but in general all portions can +be done with all parts of the team I'm a + + align:start position:0% +be done with all parts of the team I'm a + + + align:start position:0% +be done with all parts of the team I'm a +little surprised if this is uh coming + + align:start position:0% +little surprised if this is uh coming + + + align:start position:0% +little surprised if this is uh coming +from the who um + + align:start position:0% +from the who um + + + align:start position:0% +from the who um +is is it is it clear that these + + align:start position:0% +is is it is it clear that these + + + align:start position:0% +is is it is it clear that these +checklists are um more stand the right + + align:start position:0% +checklists are um more stand the right + + + align:start position:0% +checklists are um more stand the right +thing for all International situations + + align:start position:0% +thing for all International situations + + + align:start position:0% +thing for all International situations +um that's a good question so there was a + + align:start position:0% +um that's a good question so there was a + + + align:start position:0% +um that's a good question so there was a +lot of debate about what exactly to + + align:start position:0% +lot of debate about what exactly to + + + align:start position:0% +lot of debate about what exactly to +include on the checklist as you can + + align:start position:0% +include on the checklist as you can + + + align:start position:0% +include on the checklist as you can +imagine a a operating room here in + + align:start position:0% +imagine a a operating room here in + + + align:start position:0% +imagine a a operating room here in +Boston is very different from one in + + align:start position:0% +Boston is very different from one in + + + align:start position:0% +Boston is very different from one in +luaka Zambia and they have very + + align:start position:0% +luaka Zambia and they have very + + + align:start position:0% +luaka Zambia and they have very +different needs as well as very + + align:start position:0% +different needs as well as very + + + align:start position:0% +different needs as well as very +different cultures and so a lot of uh + + align:start position:0% +different cultures and so a lot of uh + + + align:start position:0% +different cultures and so a lot of uh +work was done to make them uh + + align:start position:0% +work was done to make them uh + + + align:start position:0% +work was done to make them uh +generalizable and so you see there are + + align:start position:0% +generalizable and so you see there are + + + align:start position:0% +generalizable and so you see there are +some things that here are used in Boston + + align:start position:0% +some things that here are used in Boston + + + align:start position:0% +some things that here are used in Boston +that aren't necessarily used in Zambia + + align:start position:0% +that aren't necessarily used in Zambia + + + align:start position:0% +that aren't necessarily used in Zambia +and there's some things used in Zambia + + align:start position:0% +and there's some things used in Zambia + + + align:start position:0% +and there's some things used in Zambia +that aren't used here and so I you can't + + align:start position:0% +that aren't used here and so I you can't + + + align:start position:0% +that aren't used here and so I you can't +I don't actually have it on this slide I + + align:start position:0% +I don't actually have it on this slide I + + + align:start position:0% +I don't actually have it on this slide I +think prya has it on her slides but uh + + align:start position:0% +think prya has it on her slides but uh + + + align:start position:0% +think prya has it on her slides but uh +one of the points of this is was this is + + align:start position:0% +one of the points of this is was this is + + + align:start position:0% +one of the points of this is was this is +a framework for people to use and uh + + align:start position:0% +a framework for people to use and uh + + + align:start position:0% +a framework for people to use and uh +people were encouraged to modify as they + + align:start position:0% +people were encouraged to modify as they + + + align:start position:0% +people were encouraged to modify as they +as they needed for their own specific + + align:start position:0% +as they needed for their own specific + + + align:start position:0% +as they needed for their own specific +sites so to move backwards so what was + + align:start position:0% +sites so to move backwards so what was + + + align:start position:0% +sites so to move backwards so what was +who's interest in this so who is a large + + align:start position:0% +who's interest in this so who is a large + + + align:start position:0% +who's interest in this so who is a large +uh multi- intern ational organization + + align:start position:0% +uh multi- intern ational organization + + + align:start position:0% +uh multi- intern ational organization +and if you're thinking like they are + + align:start position:0% +and if you're thinking like they are + + + align:start position:0% +and if you're thinking like they are +what they wanted was something that was + + align:start position:0% +what they wanted was something that was + + + align:start position:0% +what they wanted was something that was +applicable to All Nations something that + + align:start position:0% +applicable to All Nations something that + + + align:start position:0% +applicable to All Nations something that +was cheap and something that was easy to + + align:start position:0% +was cheap and something that was easy to + + + align:start position:0% +was cheap and something that was easy to +use I if you look at most of their + + align:start position:0% +use I if you look at most of their + + + align:start position:0% +use I if you look at most of their +interventions uh they kind of Follow + + align:start position:0% +interventions uh they kind of Follow + + + align:start position:0% +interventions uh they kind of Follow +That same model A lot of it is + + align:start position:0% +That same model A lot of it is + + + align:start position:0% +That same model A lot of it is +information based a lot of it is uh + + align:start position:0% +information based a lot of it is uh + + + align:start position:0% +information based a lot of it is uh +disseminating information as well and so + + align:start position:0% +disseminating information as well and so + + + align:start position:0% +disseminating information as well and so +this is another way you know all you + + align:start position:0% +this is another way you know all you + + + align:start position:0% +this is another way you know all you +have to do is print on a piece of paper + + align:start position:0% +have to do is print on a piece of paper + + + align:start position:0% +have to do is print on a piece of paper +send it in email and there are these uh + + align:start position:0% +send it in email and there are these uh + + + align:start position:0% +send it in email and there are these uh +you kind of have you've given them the + + align:start position:0% +you kind of have you've given them the + + + align:start position:0% +you kind of have you've given them the +framework um the difficult part is + + align:start position:0% +framework um the difficult part is + + + align:start position:0% +framework um the difficult part is +actually implementing and we'll get to + + align:start position:0% +actually implementing and we'll get to + + + align:start position:0% +actually implementing and we'll get to +that point a little later that's a good + + align:start position:0% +that point a little later that's a good + + + align:start position:0% +that point a little later that's a good +question again I forgot to mention the + + align:start position:0% +question again I forgot to mention the + + + align:start position:0% +question again I forgot to mention the +very beginning that if you do have + + align:start position:0% +very beginning that if you do have + + + align:start position:0% +very beginning that if you do have +questions please feel free to to to + + align:start position:0% +questions please feel free to to to + + + align:start position:0% +questions please feel free to to to +raise your hands and + + align:start position:0% +raise your hands and + + + align:start position:0% +raise your hands and +interrupt um so this is a little bit + + align:start position:0% +interrupt um so this is a little bit + + + align:start position:0% +interrupt um so this is a little bit +background about the checklist and you + + align:start position:0% +background about the checklist and you + + + align:start position:0% +background about the checklist and you +can see the items there are only 19 + + align:start position:0% +can see the items there are only 19 + + + align:start position:0% +can see the items there are only 19 +items um one of the concerns was that + + align:start position:0% +items um one of the concerns was that + + + align:start position:0% +items um one of the concerns was that +that using the checklist would really + + align:start position:0% +that using the checklist would really + + + align:start position:0% +that using the checklist would really +delay the the operation or increase the + + align:start position:0% +delay the the operation or increase the + + + align:start position:0% +delay the the operation or increase the +time it would take to operate and it + + align:start position:0% +time it would take to operate and it + + + align:start position:0% +time it would take to operate and it +only takes about two or three minutes + + align:start position:0% +only takes about two or three minutes + + + align:start position:0% +only takes about two or three minutes +for the whole entire checklist to be + + align:start position:0% +for the whole entire checklist to be + + + align:start position:0% +for the whole entire checklist to be +used um and so for that you know for for + + align:start position:0% +used um and so for that you know for for + + + align:start position:0% +used um and so for that you know for for +the amount of time it takes it's really + + align:start position:0% +the amount of time it takes it's really + + + align:start position:0% +the amount of time it takes it's really +minimal compared to the length of the + + align:start position:0% + + + + align:start position:0% + +case the che specific to that patient + + align:start position:0% +case the che specific to that patient + + + align:start position:0% +case the che specific to that patient +and that operation this is more General + + align:start position:0% +and that operation this is more General + + + align:start position:0% +and that operation this is more General +so is it is that the standard that this + + align:start position:0% +so is it is that the standard that this + + + align:start position:0% +so is it is that the standard that this +one is just general the CP was uh so the + + align:start position:0% +one is just general the CP was uh so the + + + align:start position:0% +one is just general the CP was uh so the +clip was actually pretty accurate um so + + align:start position:0% +clip was actually pretty accurate um so + + + align:start position:0% +clip was actually pretty accurate um so +they do a specific yeah so they ask what + + align:start position:0% +they do a specific yeah so they ask what + + + align:start position:0% +they do a specific yeah so they ask what +procedure is going on they talk as you + + align:start position:0% +procedure is going on they talk as you + + + align:start position:0% +procedure is going on they talk as you +can see uh the first question is you + + align:start position:0% +can see uh the first question is you + + + align:start position:0% +can see uh the first question is you +know has a patient identity site + + align:start position:0% +know has a patient identity site + + + align:start position:0% +know has a patient identity site +procedure and consent been uh confirmed + + align:start position:0% +procedure and consent been uh confirmed + + + align:start position:0% +procedure and consent been uh confirmed +and so uh it's known to the team what + + align:start position:0% +and so uh it's known to the team what + + + align:start position:0% +and so uh it's known to the team what +the procedure was I think that there may + + align:start position:0% +the procedure was I think that there may + + + align:start position:0% +the procedure was I think that there may +have been a couple + + align:start position:0% +have been a couple + + + align:start position:0% +have been a couple +um uh I think if I remember correctly in + + align:start position:0% +um uh I think if I remember correctly in + + + align:start position:0% +um uh I think if I remember correctly in +the in the video clip they they didn't + + align:start position:0% +the in the video clip they they didn't + + + align:start position:0% +the in the video clip they they didn't +deviate too much from what we were using + + align:start position:0% +deviate too much from what we were using + + + align:start position:0% +deviate too much from what we were using +they didn't show all the different parts + + align:start position:0% +they didn't show all the different parts + + + align:start position:0% +they didn't show all the different parts +of it but uh the parts that they used + + align:start position:0% +of it but uh the parts that they used + + + align:start position:0% +of it but uh the parts that they used +didn't + + align:start position:0% + + + + align:start position:0% + +deviate okay + + align:start position:0% + + + + align:start position:0% + +so uh you might ask so does this little + + align:start position:0% +so uh you might ask so does this little + + + align:start position:0% +so uh you might ask so does this little +piece of paper really + + align:start position:0% +piece of paper really + + + align:start position:0% +piece of paper really +work uh how how can we really know that + + align:start position:0% +work uh how how can we really know that + + + align:start position:0% +work uh how how can we really know that +bringing this piece of paper into + + align:start position:0% +bringing this piece of paper into + + + align:start position:0% +bringing this piece of paper into +different operating rooms that what kind + + align:start position:0% +different operating rooms that what kind + + + align:start position:0% +different operating rooms that what kind +of effect does this have and so the who + + align:start position:0% +of effect does this have and so the who + + + align:start position:0% +of effect does this have and so the who +before they were a before they put their + + align:start position:0% +before they were a before they put their + + + align:start position:0% +before they were a before they put their +stamp of approval on this document they + + align:start position:0% +stamp of approval on this document they + + + align:start position:0% +stamp of approval on this document they +wanted us to test it and so uh firstly + + align:start position:0% +wanted us to test it and so uh firstly + + + align:start position:0% +wanted us to test it and so uh firstly +the the concept was developed uh + + align:start position:0% +the the concept was developed uh + + + align:start position:0% +the the concept was developed uh +multiple rounds of + + align:start position:0% +multiple rounds of + + + align:start position:0% +multiple rounds of +uh revision with uh International + + align:start position:0% +uh revision with uh International + + + align:start position:0% +uh revision with uh International +consultations were were done to to decid + + align:start position:0% +consultations were were done to to decid + + + align:start position:0% +consultations were were done to to decid +on what items to keep on the checklist + + align:start position:0% +on what items to keep on the checklist + + + align:start position:0% +on what items to keep on the checklist +and then it was decided to do a pilot + + align:start position:0% +and then it was decided to do a pilot + + + align:start position:0% +and then it was decided to do a pilot +study so this pilot study involved eight + + align:start position:0% +study so this pilot study involved eight + + + align:start position:0% +study so this pilot study involved eight +different sites uh in very different + + align:start position:0% +different sites uh in very different + + + align:start position:0% +different sites uh in very different +settings you had settings in Seattle + + align:start position:0% +settings you had settings in Seattle + + + align:start position:0% +settings you had settings in Seattle +Washington as well as Tanzania all the + + align:start position:0% +Washington as well as Tanzania all the + + + align:start position:0% +Washington as well as Tanzania all the +way to India and so these were very + + align:start position:0% +way to India and so these were very + + + align:start position:0% +way to India and so these were very +diverse very different populations very + + align:start position:0% +diverse very different populations very + + + align:start position:0% +diverse very different populations very +different settings very different income + + align:start position:0% +different settings very different income + + + align:start position:0% +different settings very different income +levels and they were testing all these + + align:start position:0% +levels and they were testing all these + + + align:start position:0% +levels and they were testing all these +different sites + + align:start position:0% +different sites + + + align:start position:0% +different sites +and so the punch line is that they were + + align:start position:0% +and so the punch line is that they were + + + align:start position:0% +and so the punch line is that they were +found to reduce uh more post-operative + + align:start position:0% +found to reduce uh more post-operative + + + align:start position:0% +found to reduce uh more post-operative +complications by almost nearly a third + + align:start position:0% +complications by almost nearly a third + + + align:start position:0% +complications by almost nearly a third +and so um to break it down even more uh + + align:start position:0% +and so um to break it down even more uh + + + align:start position:0% +and so um to break it down even more uh +death was decreased from 1.5% as a whole + + align:start position:0% +death was decreased from 1.5% as a whole + + + align:start position:0% +death was decreased from 1.5% as a whole +to + + align:start position:0% +to + + + align:start position:0% +to +0.8% complications were decreased by + + align:start position:0% +0.8% complications were decreased by + + + align:start position:0% +0.8% complications were decreased by +nearly uh 40% seral site infection was + + align:start position:0% +nearly uh 40% seral site infection was + + + align:start position:0% +nearly uh 40% seral site infection was +also decreased by almost 50% and + + align:start position:0% +also decreased by almost 50% and + + + align:start position:0% +also decreased by almost 50% and +unplanned return to the O operating room + + align:start position:0% +unplanned return to the O operating room + + + align:start position:0% +unplanned return to the O operating room +decreased from 2.4 to 1.8% all of which + + align:start position:0% +decreased from 2.4 to 1.8% all of which + + + align:start position:0% +decreased from 2.4 to 1.8% all of which +were + + align:start position:0% + + + + align:start position:0% + +significant um in addition you might ask + + align:start position:0% +significant um in addition you might ask + + + align:start position:0% +significant um in addition you might ask +well does this really work in uh High + + align:start position:0% +well does this really work in uh High + + + align:start position:0% +well does this really work in uh High +income countries for example here in + + align:start position:0% +income countries for example here in + + + align:start position:0% +income countries for example here in +Boston if we were to use this where we + + align:start position:0% +Boston if we were to use this where we + + + align:start position:0% +Boston if we were to use this where we +already have relatively high standards + + align:start position:0% +already have relatively high standards + + + align:start position:0% +already have relatively high standards +of care are we really seeing a uh impact + + align:start position:0% +of care are we really seeing a uh impact + + + align:start position:0% +of care are we really seeing a uh impact +by using these pretty basic uh + + align:start position:0% +by using these pretty basic uh + + + align:start position:0% +by using these pretty basic uh +principles a lot of these principles are + + align:start position:0% +principles a lot of these principles are + + + align:start position:0% +principles a lot of these principles are +already used in a lot of operating rooms + + align:start position:0% +already used in a lot of operating rooms + + + align:start position:0% +already used in a lot of operating rooms +and so how much of this will really what + + align:start position:0% +and so how much of this will really what + + + align:start position:0% +and so how much of this will really what +kind of effect and so we we've broken it + + align:start position:0% +kind of effect and so we we've broken it + + + align:start position:0% +kind of effect and so we we've broken it +down to high income and low and middle + + align:start position:0% +down to high income and low and middle + + + align:start position:0% +down to high income and low and middle +inome countries and um we see a + + align:start position:0% +inome countries and um we see a + + + align:start position:0% +inome countries and um we see a +difference in complications that's + + align:start position:0% +difference in complications that's + + + align:start position:0% +difference in complications that's +statistically significant in regards to + + align:start position:0% +statistically significant in regards to + + + align:start position:0% +statistically significant in regards to +change in death rates uh we don't see + + align:start position:0% +change in death rates uh we don't see + + + align:start position:0% +change in death rates uh we don't see +statistical statistical significance in + + align:start position:0% +statistical statistical significance in + + + align:start position:0% +statistical statistical significance in +high income regions but there's a trend + + align:start position:0% +high income regions but there's a trend + + + align:start position:0% +high income regions but there's a trend +towards uh improvement from 0.9% to 6% + + align:start position:0% +towards uh improvement from 0.9% to 6% + + + align:start position:0% +towards uh improvement from 0.9% to 6% +and so one of the difficulties is + + align:start position:0% +and so one of the difficulties is + + + align:start position:0% +and so one of the difficulties is +there's so so few uh deaths in these + + align:start position:0% +there's so so few uh deaths in these + + + align:start position:0% +there's so so few uh deaths in these +high income countries that if we + + align:start position:0% +high income countries that if we + + + align:start position:0% +high income countries that if we +actually had larger numbers we may we + + align:start position:0% +actually had larger numbers we may we + + + align:start position:0% +actually had larger numbers we may we +may be able to show a significant + + align:start position:0% +may be able to show a significant + + + align:start position:0% +may be able to show a significant +difference and so this is kind of where + + align:start position:0% +difference and so this is kind of where + + + align:start position:0% +difference and so this is kind of where +we're at now so these studies were + + align:start position:0% +we're at now so these studies were + + + align:start position:0% +we're at now so these studies were +published in 2009 the the pilots were + + align:start position:0% +published in 2009 the the pilots were + + + align:start position:0% +published in 2009 the the pilots were +done in 2008 and then as we are now all + + align:start position:0% +done in 2008 and then as we are now all + + + align:start position:0% +done in 2008 and then as we are now all +these gold crosses are areas where the + + align:start position:0% +these gold crosses are areas where the + + + align:start position:0% +these gold crosses are areas where the +checklist is being actively used and so + + align:start position:0% +checklist is being actively used and so + + + align:start position:0% +checklist is being actively used and so +you can see it spans all across all the + + align:start position:0% +you can see it spans all across all the + + + align:start position:0% +you can see it spans all across all the +continents except for Antarctica we + + align:start position:0% +continents except for Antarctica we + + + align:start position:0% +continents except for Antarctica we +don't have one there yet uh but in + + align:start position:0% +don't have one there yet uh but in + + + align:start position:0% +don't have one there yet uh but in +multiple countries multiple languages + + align:start position:0% +multiple countries multiple languages + + + align:start position:0% +multiple countries multiple languages +multiple settings and so it's being used + + align:start position:0% +multiple settings and so it's being used + + + align:start position:0% +multiple settings and so it's being used +worldwide um I saw a question over here + + align:start position:0% +worldwide um I saw a question over here + + + align:start position:0% +worldwide um I saw a question over here +um have you or has anyone at any point + + align:start position:0% +um have you or has anyone at any point + + + align:start position:0% +um have you or has anyone at any point +uh analyzed + + align:start position:0% +uh analyzed + + + align:start position:0% +uh analyzed +items on the check list might be most + + align:start position:0% +items on the check list might be most + + + align:start position:0% +items on the check list might be most +critical to so that's a good point so so + + align:start position:0% +critical to so that's a good point so so + + + align:start position:0% +critical to so that's a good point so so +a lot of these complications are + + align:start position:0% +a lot of these complications are + + + align:start position:0% +a lot of these complications are +infectious complications so we saw + + align:start position:0% +infectious complications so we saw + + + align:start position:0% +infectious complications so we saw +before um surgical sight infection a lot + + align:start position:0% +before um surgical sight infection a lot + + + align:start position:0% +before um surgical sight infection a lot +of these surgical sight infections were + + align:start position:0% +of these surgical sight infections were + + + align:start position:0% +of these surgical sight infections were +also if you had any of these + + align:start position:0% +also if you had any of these + + + align:start position:0% +also if you had any of these +complications a lot of them were + + align:start position:0% +complications a lot of them were + + + align:start position:0% +complications a lot of them were +surgical sight infections pneumonias + + align:start position:0% +surgical sight infections pneumonias + + + align:start position:0% +surgical sight infections pneumonias +things that were considered infectious + + align:start position:0% +things that were considered infectious + + + align:start position:0% +things that were considered infectious +and so um it's uh we we've done some + + align:start position:0% +and so um it's uh we we've done some + + + align:start position:0% +and so um it's uh we we've done some +subanalysis and it so looks like that + + align:start position:0% +subanalysis and it so looks like that + + + align:start position:0% +subanalysis and it so looks like that +there has been changes in the Infectious + + align:start position:0% +there has been changes in the Infectious + + + align:start position:0% +there has been changes in the Infectious +complications as well as the + + align:start position:0% +complications as well as the + + + align:start position:0% +complications as well as the +non-infectious complications so U one of + + align:start position:0% +non-infectious complications so U one of + + + align:start position:0% +non-infectious complications so U one of +the criticisms we've had is that well + + align:start position:0% +the criticisms we've had is that well + + + align:start position:0% +the criticisms we've had is that well +all this is because you're uh asking + + align:start position:0% +all this is because you're uh asking + + + align:start position:0% +all this is because you're uh asking +people to give antibiotics on time you + + align:start position:0% +people to give antibiotics on time you + + + align:start position:0% +people to give antibiotics on time you +know something that's not being done + + align:start position:0% +know something that's not being done + + + align:start position:0% +know something that's not being done +very frequently sure that that may be a + + align:start position:0% +very frequently sure that that may be a + + + align:start position:0% +very frequently sure that that may be a +large component of it but I think that + + align:start position:0% +large component of it but I think that + + + align:start position:0% +large component of it but I think that +in addition to that um uh there are + + align:start position:0% +in addition to that um uh there are + + + align:start position:0% +in addition to that um uh there are +other parts of the checklist that are uh + + align:start position:0% +other parts of the checklist that are uh + + + align:start position:0% +other parts of the checklist that are uh +contributing to the effect I think + + align:start position:0% +contributing to the effect I think + + + align:start position:0% +contributing to the effect I think +antibiotics are playing a huge part of + + align:start position:0% +antibiotics are playing a huge part of + + + align:start position:0% +antibiotics are playing a huge part of +it I think some of the monitoring + + align:start position:0% +it I think some of the monitoring + + + align:start position:0% +it I think some of the monitoring +devices that we are encouraging people + + align:start position:0% +devices that we are encouraging people + + + align:start position:0% +devices that we are encouraging people +to use through the checklist are are are + + align:start position:0% +to use through the checklist are are are + + + align:start position:0% +to use through the checklist are are are +um contributing to the effect as well so + + align:start position:0% +um contributing to the effect as well so + + + align:start position:0% +um contributing to the effect as well so +it's possible maybe with five items on + + align:start position:0% +it's possible maybe with five items on + + + align:start position:0% +it's possible maybe with five items on +the checklist you can get 95% of the + + align:start position:0% +the checklist you can get 95% of the + + + align:start position:0% +the checklist you can get 95% of the +results not that that's good or bad just + + align:start position:0% +results not that that's good or bad just + + + align:start position:0% +results not that that's good or bad just +I think you're I think that may be right + + align:start position:0% +I think you're I think that may be right + + + align:start position:0% +I think you're I think that may be right +uh but I think there's probably more of + + align:start position:0% +uh but I think there's probably more of + + + align:start position:0% +uh but I think there's probably more of +kind of a the teamwork communication bit + + align:start position:0% +kind of a the teamwork communication bit + + + align:start position:0% +kind of a the teamwork communication bit +that's going into it so you know if you + + align:start position:0% +that's going into it so you know if you + + + align:start position:0% +that's going into it so you know if you +look at unplanned return to the + + align:start position:0% +look at unplanned return to the + + + align:start position:0% +look at unplanned return to the +operation operating room I don't know + + align:start position:0% +operation operating room I don't know + + + align:start position:0% +operation operating room I don't know +exactly what part of the check + + align:start position:0% +exactly what part of the check + + + align:start position:0% +exactly what part of the check +contributes to that you know what part + + align:start position:0% +contributes to that you know what part + + + align:start position:0% +contributes to that you know what part +of this of these 19 items really + + align:start position:0% +of this of these 19 items really + + + align:start position:0% +of this of these 19 items really +prevents the need to go back to the + + align:start position:0% +prevents the need to go back to the + + + align:start position:0% +prevents the need to go back to the +operating room don't really know but + + align:start position:0% +operating room don't really know but + + + align:start position:0% +operating room don't really know but +what it does suggest is maybe we're + + align:start position:0% +what it does suggest is maybe we're + + + align:start position:0% +what it does suggest is maybe we're +doing the operations better uh in + + align:start position:0% +doing the operations better uh in + + + align:start position:0% +doing the operations better uh in +general and so it's maybe some of that + + align:start position:0% +general and so it's maybe some of that + + + align:start position:0% +general and so it's maybe some of that +and this is something that's very + + align:start position:0% +and this is something that's very + + + align:start position:0% +and this is something that's very +difficult to capture scientifically but + + align:start position:0% +difficult to capture scientifically but + + + align:start position:0% +difficult to capture scientifically but +I think there's there there's something + + align:start position:0% +I think there's there there's something + + + align:start position:0% +I think there's there there's something +else behind the checklist than just the + + align:start position:0% +else behind the checklist than just the + + + align:start position:0% +else behind the checklist than just the +items on the checklist it's actually the + + align:start position:0% +items on the checklist it's actually the + + + align:start position:0% +items on the checklist it's actually the +process of using this and I think in my + + align:start position:0% +process of using this and I think in my + + + align:start position:0% +process of using this and I think in my +experience + + align:start position:0% +experience + + + align:start position:0% +experience +it's actually this idea of uh we want to + + align:start position:0% +it's actually this idea of uh we want to + + + align:start position:0% +it's actually this idea of uh we want to +use this we're interested in quality + + align:start position:0% +use this we're interested in quality + + + align:start position:0% +use this we're interested in quality +improvement and so therefore uh that + + align:start position:0% +improvement and so therefore uh that + + + align:start position:0% +improvement and so therefore uh that +kind of culture that's changed by using + + align:start position:0% +kind of culture that's changed by using + + + align:start position:0% +kind of culture that's changed by using +this type of Tool uh is what kind of + + align:start position:0% +this type of Tool uh is what kind of + + + align:start position:0% +this type of Tool uh is what kind of +adds to that that effect I think this + + align:start position:0% +adds to that that effect I think this + + + align:start position:0% +adds to that that effect I think this +goes a lot towards uh some of the + + align:start position:0% +goes a lot towards uh some of the + + + align:start position:0% +goes a lot towards uh some of the +technologies that you've talked about + + align:start position:0% +technologies that you've talked about + + + align:start position:0% +technologies that you've talked about +here uh Technologies are great uh and + + align:start position:0% +here uh Technologies are great uh and + + + align:start position:0% +here uh Technologies are great uh and +they do help uh but really you need the + + align:start position:0% +they do help uh but really you need the + + + align:start position:0% +they do help uh but really you need the +people using them to have an interest in + + align:start position:0% +people using them to have an interest in + + + align:start position:0% +people using them to have an interest in +them you need the people who are using + + align:start position:0% +them you need the people who are using + + + align:start position:0% +them you need the people who are using +them to want to improve and so that kind + + align:start position:0% +them to want to improve and so that kind + + + align:start position:0% +them to want to improve and so that kind +of catalyst I think makes a big + + align:start position:0% +of catalyst I think makes a big + + + align:start position:0% +of catalyst I think makes a big +difference go here in you don't think + + align:start position:0% +difference go here in you don't think + + + align:start position:0% +difference go here in you don't think +you'll getv approval for Le one + + align:start position:0% +you'll getv approval for Le one + + + align:start position:0% +you'll getv approval for Le one +out uh I think we could um I think we + + align:start position:0% +out uh I think we could um I think we + + + align:start position:0% +out uh I think we could um I think we +could if you leave a portion out yeah I + + align:start position:0% +could if you leave a portion out yeah I + + + align:start position:0% +could if you leave a portion out yeah I +think you'd have to leave 19 portions + + align:start position:0% +think you'd have to leave 19 portions + + + align:start position:0% +think you'd have to leave 19 portions +out or just do 19 separate experiments + + align:start position:0% +out or just do 19 separate experiments + + + align:start position:0% +out or just do 19 separate experiments +but um uh we could I'll go here and then + + align:start position:0% +but um uh we could I'll go here and then + + + align:start position:0% +but um uh we could I'll go here and then +here are you seeing a difference in how + + align:start position:0% +here are you seeing a difference in how + + + align:start position:0% +here are you seeing a difference in how +receptive people are depending on their + + align:start position:0% +receptive people are depending on their + + + align:start position:0% +receptive people are depending on their +age + + align:start position:0% + + + + align:start position:0% + +ad being more to this we are certainly + + align:start position:0% +ad being more to this we are certainly + + + align:start position:0% +ad being more to this we are certainly +seeing a difference in uh the I guess + + align:start position:0% +seeing a difference in uh the I guess + + + align:start position:0% +seeing a difference in uh the I guess +the buyin + + align:start position:0% +the buyin + + + align:start position:0% +the buyin +into uh the checklist and you've + + align:start position:0% +into uh the checklist and you've + + + align:start position:0% +into uh the checklist and you've +probably read about some of this you + + align:start position:0% +probably read about some of this you + + + align:start position:0% +probably read about some of this you +know you have your laggards you have + + align:start position:0% +know you have your laggards you have + + + align:start position:0% +know you have your laggards you have +your early adopters and you have kind of + + align:start position:0% +your early adopters and you have kind of + + + align:start position:0% +your early adopters and you have kind of +the people in between and so we + + align:start position:0% +the people in between and so we + + + align:start position:0% +the people in between and so we +certainly have a lot of early adopters + + align:start position:0% +certainly have a lot of early adopters + + + align:start position:0% +certainly have a lot of early adopters +but in a lot of these hospitals + + align:start position:0% +but in a lot of these hospitals + + + align:start position:0% +but in a lot of these hospitals +especially in some of these limited + + align:start position:0% +especially in some of these limited + + + align:start position:0% +especially in some of these limited +resource areas there are a lot of + + align:start position:0% +resource areas there are a lot of + + + align:start position:0% +resource areas there are a lot of +laggards who are are comfortable with + + align:start position:0% +laggards who are are comfortable with + + + align:start position:0% +laggards who are are comfortable with +what they're doing they are don't want + + align:start position:0% +what they're doing they are don't want + + + align:start position:0% +what they're doing they are don't want +to change and uh and in general it seems + + align:start position:0% +to change and uh and in general it seems + + + align:start position:0% +to change and uh and in general it seems +that people who are beginning their + + align:start position:0% +that people who are beginning their + + + align:start position:0% +that people who are beginning their +training and may have more kind of fear + + align:start position:0% +training and may have more kind of fear + + + align:start position:0% +training and may have more kind of fear +in the operating room they're the people + + align:start position:0% +in the operating room they're the people + + + align:start position:0% +in the operating room they're the people +who seem to to grasp onto these tools + + align:start position:0% +who seem to to grasp onto these tools + + + align:start position:0% +who seem to to grasp onto these tools +more I just thinking that it's an + + align:start position:0% +more I just thinking that it's an + + + align:start position:0% +more I just thinking that it's an +example where we've talked before about + + align:start position:0% +example where we've talked before about + + + align:start position:0% +example where we've talked before about +being able to collect data accurately in + + align:start position:0% +being able to collect data accurately in + + + align:start position:0% +being able to collect data accurately in +clinical settings as being one of the + + align:start position:0% +clinical settings as being one of the + + + align:start position:0% +clinical settings as being one of the +most important things you can do with + + align:start position:0% +most important things you can do with + + + align:start position:0% +most important things you can do with +the information system because that + + align:start position:0% +the information system because that + + + align:start position:0% +the information system because that +gives you some of the background data + + align:start position:0% +gives you some of the background data + + + align:start position:0% +gives you some of the background data +that lets you answer one of these + + align:start position:0% +that lets you answer one of these + + + align:start position:0% +that lets you answer one of these +questions so you you know what are the + + align:start position:0% +questions so you you know what are the + + + align:start position:0% +questions so you you know what are the +ethics of doing a you know Le one out + + align:start position:0% +ethics of doing a you know Le one out + + + align:start position:0% +ethics of doing a you know Le one out +type of study which you know is + + align:start position:0% +type of study which you know is + + + align:start position:0% +type of study which you know is +certainly one of the more definitive + + align:start position:0% +certainly one of the more definitive + + + align:start position:0% +certainly one of the more definitive +ways of doing this if you knew more + + align:start position:0% +ways of doing this if you knew more + + + align:start position:0% +ways of doing this if you knew more +about the nature Publications more about + + align:start position:0% +about the nature Publications more about + + + align:start position:0% +about the nature Publications more about +the kind of things that were going on + + align:start position:0% +the kind of things that were going on + + + align:start position:0% +the kind of things that were going on +with routine cical cases with with a a + + align:start position:0% +with routine cical cases with with a a + + + align:start position:0% +with routine cical cases with with a a +simple but you know useful core data set + + align:start position:0% +simple but you know useful core data set + + + align:start position:0% +simple but you know useful core data set +then I think that would be much very + + align:start position:0% +then I think that would be much very + + + align:start position:0% +then I think that would be much very +much easier to to look at this and see + + align:start position:0% +much easier to to look at this and see + + + align:start position:0% +much easier to to look at this and see +whether you actually want to revise the + + align:start position:0% +whether you actually want to revise the + + + align:start position:0% +whether you actually want to revise the +chck in other ways adding something + + align:start position:0% +chck in other ways adding something + + + align:start position:0% +chck in other ways adding something +right I I think that's a key point you + + align:start position:0% +right I I think that's a key point you + + + align:start position:0% +right I I think that's a key point you +know data collection we'll get I I'll + + align:start position:0% +know data collection we'll get I I'll + + + align:start position:0% +know data collection we'll get I I'll +have a couple slides later on to talk + + align:start position:0% +have a couple slides later on to talk + + + align:start position:0% +have a couple slides later on to talk +about the importance of data collection + + align:start position:0% +about the importance of data collection + + + align:start position:0% +about the importance of data collection +but uh it certainly is uh helps you + + align:start position:0% +but uh it certainly is uh helps you + + + align:start position:0% +but uh it certainly is uh helps you +understand what's going on here a lot + + align:start position:0% +understand what's going on here a lot + + + align:start position:0% +understand what's going on here a lot +better I just wanted to respond to + + align:start position:0% +better I just wanted to respond to + + + align:start position:0% +better I just wanted to respond to +questions one about an item the check + + align:start position:0% +questions one about an item the check + + + align:start position:0% +questions one about an item the check +and two sort of attrition Factor perhaps + + align:start position:0% +and two sort of attrition Factor perhaps + + + align:start position:0% +and two sort of attrition Factor perhaps +we just have to wait for the to go + + align:start position:0% +we just have to wait for the to go + + + align:start position:0% +we just have to wait for the to go +and actually if you looked at the um + + align:start position:0% +and actually if you looked at the um + + + align:start position:0% +and actually if you looked at the um +Korean I think it was Korean a they had + + align:start position:0% +Korean I think it was Korean a they had + + + align:start position:0% +Korean I think it was Korean a they had +they had Che in place pilot have been + + align:start position:0% +they had Che in place pilot have been + + + align:start position:0% +they had Che in place pilot have been +around since the 1930s and they were + + align:start position:0% +around since the 1930s and they were + + + align:start position:0% +around since the 1930s and they were +having lots of accidents and when they + + align:start position:0% +having lots of accidents and when they + + + align:start position:0% +having lots of accidents and when they +analyed + + align:start position:0% +analyed + + + align:start position:0% +analyed +long story short thing americ go over to + + align:start position:0% +long story short thing americ go over to + + + align:start position:0% +long story short thing americ go over to +Korea and say well what's going + + align:start position:0% +Korea and say well what's going + + + align:start position:0% +Korea and say well what's going +on and his solution was I think you + + align:start position:0% +on and his solution was I think you + + + align:start position:0% +on and his solution was I think you +should speak + + align:start position:0% +should speak + + + align:start position:0% +should speak +English that's your solution to our + + align:start position:0% +English that's your solution to our + + + align:start position:0% +English that's your solution to our +accidents you know you arrogant person + + align:start position:0% +accidents you know you arrogant person + + + align:start position:0% +accidents you know you arrogant person +and he said no what's happening is + + align:start position:0% +and he said no what's happening is + + + align:start position:0% +and he said no what's happening is +you're bringing your culture into the + + align:start position:0% +you're bringing your culture into the + + + align:start position:0% +you're bringing your culture into the +CIT of your language and the culture is + + align:start position:0% +CIT of your language and the culture is + + + align:start position:0% +CIT of your language and the culture is +very hierarchical so the pilot is the + + align:start position:0% +very hierarchical so the pilot is the + + + align:start position:0% +very hierarchical so the pilot is the +old one he's experienc and the co-pilot + + align:start position:0% +old one he's experienc and the co-pilot + + + align:start position:0% +old one he's experienc and the co-pilot +even though he's supposed to be able to + + align:start position:0% +even though he's supposed to be able to + + + align:start position:0% +even though he's supposed to be able to +correct him can't because well you know + + align:start position:0% +correct him can't because well you know + + + align:start position:0% +correct him can't because well you know +old and if you just speak English you're + + align:start position:0% +old and if you just speak English you're + + + align:start position:0% +old and if you just speak English you're +changing the culture in the and + + align:start position:0% +changing the culture in the and + + + align:start position:0% +changing the culture in the and +it's that empowering the younger persons + + align:start position:0% +it's that empowering the younger persons + + + align:start position:0% +it's that empowering the younger persons +it's empowering the nurses in the who + + align:start position:0% +it's empowering the nurses in the who + + + align:start position:0% +it's empowering the nurses in the who +you know it's been shown who won't say + + align:start position:0% +you know it's been shown who won't say + + + align:start position:0% +you know it's been shown who won't say +see said to Happ they say kind of + + align:start position:0% +see said to Happ they say kind of + + + align:start position:0% +see said to Happ they say kind of +whisper surge just didn't hear so I + + align:start position:0% +whisper surge just didn't hear so I + + + align:start position:0% +whisper surge just didn't hear so I +think that teamwork and culture + + align:start position:0% +think that teamwork and culture + + + align:start position:0% +think that teamwork and culture +component is critical to the checklist + + align:start position:0% +component is critical to the checklist + + + align:start position:0% +component is critical to the checklist +and it's really critical to the people + + align:start position:0% +and it's really critical to the people + + + align:start position:0% +and it's really critical to the people +who aren't empowered um because it + + align:start position:0% + + + + align:start position:0% + +good question go ahead the + + align:start position:0% +good question go ahead the + + + align:start position:0% +good question go ahead the +issues + + align:start position:0% + + + + align:start position:0% + +supp + + align:start position:0% +supp + + + align:start position:0% +supp +yeah um so the you know uh in general in + + align:start position:0% +yeah um so the you know uh in general in + + + align:start position:0% +yeah um so the you know uh in general in +my experience so the uh the + + align:start position:0% +my experience so the uh the + + + align:start position:0% +my experience so the uh the +institution do you mean you mean as a as + + align:start position:0% +institution do you mean you mean as a as + + + align:start position:0% +institution do you mean you mean as a as +a hospital as a whole what would be the + + align:start position:0% +a hospital as a whole what would be the + + + align:start position:0% +a hospital as a whole what would be the +so in general I I found that people are + + align:start position:0% +so in general I I found that people are + + + align:start position:0% +so in general I I found that people are +really supportive of this from admin + + align:start position:0% +really supportive of this from admin + + + align:start position:0% +really supportive of this from admin +ative point of view it costs very little + + align:start position:0% +ative point of view it costs very little + + + align:start position:0% +ative point of view it costs very little +uh all you have to do is ask the + + align:start position:0% +uh all you have to do is ask the + + + align:start position:0% +uh all you have to do is ask the +surgeons nurses anesthesiologists to do + + align:start position:0% +surgeons nurses anesthesiologists to do + + + align:start position:0% +surgeons nurses anesthesiologists to do +it and so but that's been the challenge + + align:start position:0% +it and so but that's been the challenge + + + align:start position:0% +it and so but that's been the challenge +finding uh ways to ask people to change + + align:start position:0% +finding uh ways to ask people to change + + + align:start position:0% +finding uh ways to ask people to change +the culture of the of the practice there + + align:start position:0% +the culture of the of the practice there + + + align:start position:0% +the culture of the of the practice there +and so really uh the idea of accepting + + align:start position:0% +and so really uh the idea of accepting + + + align:start position:0% +and so really uh the idea of accepting +it seems easy but actually practicing it + + align:start position:0% +it seems easy but actually practicing it + + + align:start position:0% +it seems easy but actually practicing it +seems + + align:start position:0% +seems + + + align:start position:0% +seems +difficult and so kind of getting Buy in + + align:start position:0% +difficult and so kind of getting Buy in + + + align:start position:0% +difficult and so kind of getting Buy in +from all your laggards all and really + + align:start position:0% +from all your laggards all and really + + + align:start position:0% +from all your laggards all and really +all it takes is a couple people to + + align:start position:0% +all it takes is a couple people to + + + align:start position:0% +all it takes is a couple people to +badmouth it to make it a a a difficult + + align:start position:0% +badmouth it to make it a a a difficult + + + align:start position:0% +badmouth it to make it a a a difficult +experience are there places with kind of + + align:start position:0% +experience are there places with kind of + + + align:start position:0% +experience are there places with kind of +institutional incentives for using the + + align:start position:0% +institutional incentives for using the + + + align:start position:0% +institutional incentives for using the +checklist so there are and I'm G to talk + + align:start position:0% +checklist so there are and I'm G to talk + + + align:start position:0% +checklist so there are and I'm G to talk +a little bit about one of those places + + align:start position:0% +a little bit about one of those places + + + align:start position:0% +a little bit about one of those places +and I I'll I'll uh I would say there are + + align:start position:0% +and I I'll I'll uh I would say there are + + + align:start position:0% +and I I'll I'll uh I would say there are +some places that are very used to having + + align:start position:0% +some places that are very used to having + + + align:start position:0% +some places that are very used to having +top down Direction and so in one of the + + align:start position:0% +top down Direction and so in one of the + + + align:start position:0% +top down Direction and so in one of the +countries I uh I'm going to talk about + + align:start position:0% +countries I uh I'm going to talk about + + + align:start position:0% +countries I uh I'm going to talk about +mdova they're a East former Soviet Union + + align:start position:0% +mdova they're a East former Soviet Union + + + align:start position:0% +mdova they're a East former Soviet Union +uh country uh and they're kind of used + + align:start position:0% +uh country uh and they're kind of used + + + align:start position:0% +uh country uh and they're kind of used +to the dictum comes from the top and we + + align:start position:0% +to the dictum comes from the top and we + + + align:start position:0% +to the dictum comes from the top and we +do what they say whereas in Zambia which + + align:start position:0% +do what they say whereas in Zambia which + + + align:start position:0% +do what they say whereas in Zambia which +I'll talk about a little later we're + + align:start position:0% +I'll talk about a little later we're + + + align:start position:0% +I'll talk about a little later we're +having a difficult time there because um + + align:start position:0% +having a difficult time there because um + + + align:start position:0% +having a difficult time there because um +even though that's the case there is a + + align:start position:0% +even though that's the case there is a + + + align:start position:0% +even though that's the case there is a +lot of uh uh this hierarchy thing is uh + + align:start position:0% +lot of uh uh this hierarchy thing is uh + + + align:start position:0% +lot of uh uh this hierarchy thing is uh +I don't know there's just a lot of + + align:start position:0% +I don't know there's just a lot of + + + align:start position:0% +I don't know there's just a lot of +bureaucracy there and so it doesn't seem + + align:start position:0% +bureaucracy there and so it doesn't seem + + + align:start position:0% +bureaucracy there and so it doesn't seem +to be moving as as as uh + + align:start position:0% + + + + align:start position:0% + +smoothly uh so this is uh one of our + + align:start position:0% +smoothly uh so this is uh one of our + + + align:start position:0% +smoothly uh so this is uh one of our +checklists that we're using in the + + align:start position:0% +checklists that we're using in the + + + align:start position:0% +checklists that we're using in the +University teaching Hospital in laka + + align:start position:0% +University teaching Hospital in laka + + + align:start position:0% +University teaching Hospital in laka +Zambia and I'm going to move now to + + align:start position:0% +Zambia and I'm going to move now to + + + align:start position:0% +Zambia and I'm going to move now to +we've talked about the checklist as a + + align:start position:0% +we've talked about the checklist as a + + + align:start position:0% +we've talked about the checklist as a +whole kind of briefly now I'm going to + + align:start position:0% +whole kind of briefly now I'm going to + + + align:start position:0% +whole kind of briefly now I'm going to +move to kind of limited resource areas + + align:start position:0% +move to kind of limited resource areas + + + align:start position:0% +move to kind of limited resource areas +or or lower middle inome lower income + + align:start position:0% +or or lower middle inome lower income + + + align:start position:0% +or or lower middle inome lower income +countries and so uh as I mentioned there + + align:start position:0% +countries and so uh as I mentioned there + + + align:start position:0% +countries and so uh as I mentioned there +are 19 items these are all the same 19 + + align:start position:0% +are 19 items these are all the same 19 + + + align:start position:0% +are 19 items these are all the same 19 +items but one of the difficulties with + + align:start position:0% +items but one of the difficulties with + + + align:start position:0% +items but one of the difficulties with +this is if the who wants to support this + + align:start position:0% +this is if the who wants to support this + + + align:start position:0% +this is if the who wants to support this +what do you do about these this portion + + align:start position:0% +what do you do about these this portion + + + align:start position:0% +what do you do about these this portion +here PSO symmetry so uh puls oximeter is + + align:start position:0% +here PSO symmetry so uh puls oximeter is + + + align:start position:0% +here PSO symmetry so uh puls oximeter is +a is a uh technology developed in the + + align:start position:0% +a is a uh technology developed in the + + + align:start position:0% +a is a uh technology developed in the +80s uh that is used to measure oxygen + + align:start position:0% +80s uh that is used to measure oxygen + + + align:start position:0% +80s uh that is used to measure oxygen +saturation or the level of oxygen in the + + align:start position:0% +saturation or the level of oxygen in the + + + align:start position:0% +saturation or the level of oxygen in the +blood and so when you're under general + + align:start position:0% +blood and so when you're under general + + + align:start position:0% +blood and so when you're under general +anesthesia uh you're sedated and you may + + align:start position:0% +anesthesia uh you're sedated and you may + + + align:start position:0% +anesthesia uh you're sedated and you may +not breathe as well and so as a result + + align:start position:0% +not breathe as well and so as a result + + + align:start position:0% +not breathe as well and so as a result +your oxygen level decreases if your + + align:start position:0% +your oxygen level decreases if your + + + align:start position:0% +your oxygen level decreases if your +oxygen level is low enough you can have + + align:start position:0% +oxygen level is low enough you can have + + + align:start position:0% +oxygen level is low enough you can have +your your heart can stop you can have + + align:start position:0% +your your heart can stop you can have + + + align:start position:0% +your your heart can stop you can have +other uh injuries as well some people + + align:start position:0% +other uh injuries as well some people + + + align:start position:0% +other uh injuries as well some people +might say that your um your ability to + + align:start position:0% +might say that your um your ability to + + + align:start position:0% +might say that your um your ability to +heal your wounds or your your profusion + + align:start position:0% +heal your wounds or your your profusion + + + align:start position:0% +heal your wounds or your your profusion +to different parts of your body is is is + + align:start position:0% +to different parts of your body is is is + + + align:start position:0% +to different parts of your body is is is +worse and so uh these little boxes I + + align:start position:0% +worse and so uh these little boxes I + + + align:start position:0% +worse and so uh these little boxes I +have a picture um actually that's not + + align:start position:0% +have a picture um actually that's not + + + align:start position:0% +have a picture um actually that's not +the picture I want but they're they're + + align:start position:0% +the picture I want but they're they're + + + align:start position:0% +the picture I want but they're they're +quite expensive in the United States if + + align:start position:0% +quite expensive in the United States if + + + align:start position:0% +quite expensive in the United States if +you're if you were to buy one it's about + + align:start position:0% +you're if you were to buy one it's about + + + align:start position:0% +you're if you were to buy one it's about +$1,200 per unit so if you can imagine in + + align:start position:0% +$1,200 per unit so if you can imagine in + + + align:start position:0% +$1,200 per unit so if you can imagine in +the this teaching hospital that has 12 + + align:start position:0% +the this teaching hospital that has 12 + + + align:start position:0% +the this teaching hospital that has 12 +operating rooms uh to buy 12 of them is + + align:start position:0% +operating rooms uh to buy 12 of them is + + + align:start position:0% +operating rooms uh to buy 12 of them is +quite a significant resource intense + + align:start position:0% +quite a significant resource intense + + + align:start position:0% +quite a significant resource intense +task for them to do and so the who um + + align:start position:0% +task for them to do and so the who um + + + align:start position:0% +task for them to do and so the who um +what we set out to do is to show that + + align:start position:0% +what we set out to do is to show that + + + align:start position:0% +what we set out to do is to show that +poock symmetry was actually something + + align:start position:0% +poock symmetry was actually something + + + align:start position:0% +poock symmetry was actually something +that was important to for Ministries and + + align:start position:0% +that was important to for Ministries and + + + align:start position:0% +that was important to for Ministries and +for uh countries to consider how to make + + align:start position:0% +for uh countries to consider how to make + + + align:start position:0% +for uh countries to consider how to make +these more accessible for their for + + align:start position:0% +these more accessible for their for + + + align:start position:0% +these more accessible for their for +their uh countries in addition to that + + align:start position:0% +their uh countries in addition to that + + + align:start position:0% +their uh countries in addition to that +the who is has uh worked as a + + align:start position:0% +the who is has uh worked as a + + + align:start position:0% +the who is has uh worked as a +procurement uh body to procure uh drugs + + align:start position:0% +procurement uh body to procure uh drugs + + + align:start position:0% +procurement uh body to procure uh drugs +as well as devices and so the thought + + align:start position:0% +as well as devices and so the thought + + + align:start position:0% +as well as devices and so the thought +was if we can show that this is actually + + align:start position:0% +was if we can show that this is actually + + + align:start position:0% +was if we can show that this is actually +a very important thing that this package + + align:start position:0% +a very important thing that this package + + + align:start position:0% +a very important thing that this package +of the checklist and pulso symmetry + + align:start position:0% +of the checklist and pulso symmetry + + + align:start position:0% +of the checklist and pulso symmetry +would be worth the who investing their + + align:start position:0% +would be worth the who investing their + + + align:start position:0% +would be worth the who investing their +their time and efforts into developing a + + align:start position:0% +their time and efforts into developing a + + + align:start position:0% +their time and efforts into developing a +procurement of these to to provide for + + align:start position:0% +procurement of these to to provide for + + + align:start position:0% +procurement of these to to provide for +low-income countries and so this is a + + align:start position:0% +low-income countries and so this is a + + + align:start position:0% +low-income countries and so this is a +picture of the one of the new o Suites + + align:start position:0% +picture of the one of the new o Suites + + + align:start position:0% +picture of the one of the new o Suites +in the bring Woman's Hospital very nice + + align:start position:0% +in the bring Woman's Hospital very nice + + + align:start position:0% +in the bring Woman's Hospital very nice +you can see the the flat screen TVs you + + align:start position:0% +you can see the the flat screen TVs you + + + align:start position:0% +you can see the the flat screen TVs you +can get uh there Bose speakers in there + + align:start position:0% +can get uh there Bose speakers in there + + + align:start position:0% +can get uh there Bose speakers in there +so if you want some music you can listen + + align:start position:0% +so if you want some music you can listen + + + align:start position:0% +so if you want some music you can listen +to music while you're operating so + + align:start position:0% +to music while you're operating so + + + align:start position:0% +to music while you're operating so +they're very nice operating Suites uh + + align:start position:0% +they're very nice operating Suites uh + + + align:start position:0% +they're very nice operating Suites uh +bringing women's and so they're if you + + align:start position:0% +bringing women's and so they're if you + + + align:start position:0% +bringing women's and so they're if you +look in the back wall all those are + + align:start position:0% +look in the back wall all those are + + + align:start position:0% +look in the back wall all those are +supplies there's all the different types + + align:start position:0% +supplies there's all the different types + + + align:start position:0% +supplies there's all the different types +of sutures all the sponges all the + + align:start position:0% +of sutures all the sponges all the + + + align:start position:0% +of sutures all the sponges all the +little gadgets you would ever want this + + align:start position:0% +little gadgets you would ever want this + + + align:start position:0% +little gadgets you would ever want this +is in Zambia a little different if you + + align:start position:0% +is in Zambia a little different if you + + + align:start position:0% +is in Zambia a little different if you +can see the anesthesia machine up in the + + align:start position:0% +can see the anesthesia machine up in the + + + align:start position:0% +can see the anesthesia machine up in the +top left it's basically a tubing in a + + align:start position:0% +top left it's basically a tubing in a + + + align:start position:0% +top left it's basically a tubing in a +little bag that you you know you you you + + align:start position:0% +little bag that you you know you you you + + + align:start position:0% +little bag that you you know you you you +squeeze uh this is the operting room + + align:start position:0% +squeeze uh this is the operting room + + + align:start position:0% +squeeze uh this is the operting room +table not as comfortable as the other + + align:start position:0% +table not as comfortable as the other + + + align:start position:0% +table not as comfortable as the other +one uh equipments uh available maybe a + + align:start position:0% +one uh equipments uh available maybe a + + + align:start position:0% +one uh equipments uh available maybe a +couple sponges couple uh sutures that's + + align:start position:0% +couple sponges couple uh sutures that's + + + align:start position:0% +couple sponges couple uh sutures that's +about it um so it's it's a very + + align:start position:0% +about it um so it's it's a very + + + align:start position:0% +about it um so it's it's a very +different uh setting moving to Eastern + + align:start position:0% +different uh setting moving to Eastern + + + align:start position:0% +different uh setting moving to Eastern +Europe This is mdova maybe a little bit + + align:start position:0% +Europe This is mdova maybe a little bit + + + align:start position:0% +Europe This is mdova maybe a little bit +more developed and a little bit more + + align:start position:0% +more developed and a little bit more + + + align:start position:0% +more developed and a little bit more +equipment there uh but if you actually + + align:start position:0% +equipment there uh but if you actually + + + align:start position:0% +equipment there uh but if you actually +look closely the equipment it's all very + + align:start position:0% +look closely the equipment it's all very + + + align:start position:0% +look closely the equipment it's all very +old it's all reused uh if you can look + + align:start position:0% +old it's all reused uh if you can look + + + align:start position:0% +old it's all reused uh if you can look +at some of the + + align:start position:0% +at some of the + + + align:start position:0% +at some of the +laparoscopic uh devices there which I + + align:start position:0% +laparoscopic uh devices there which I + + + align:start position:0% +laparoscopic uh devices there which I +was surprised to see laparoscopy there + + align:start position:0% +was surprised to see laparoscopy there + + + align:start position:0% +was surprised to see laparoscopy there +but they're all things that are + + align:start position:0% +but they're all things that are + + + align:start position:0% +but they're all things that are +generally disposable in the United + + align:start position:0% +generally disposable in the United + + + align:start position:0% +generally disposable in the United +States use once but they use multiple + + align:start position:0% +States use once but they use multiple + + + align:start position:0% +States use once but they use multiple +times and something that you never + + align:start position:0% +times and something that you never + + + align:start position:0% +times and something that you never +really see here there's two patients in + + align:start position:0% +really see here there's two patients in + + + align:start position:0% +really see here there's two patients in +the same room and this they have 12 + + align:start position:0% +the same room and this they have 12 + + + align:start position:0% +the same room and this they have 12 +operating rooms there are 22 beds or + + align:start position:0% +operating rooms there are 22 beds or + + + align:start position:0% +operating rooms there are 22 beds or +operating tables so most of their + + align:start position:0% +operating tables so most of their + + + align:start position:0% +operating tables so most of their +operating rooms have multiple tables and + + align:start position:0% +operating rooms have multiple tables and + + + align:start position:0% +operating rooms have multiple tables and +you can imagine kind of how crowded and + + align:start position:0% +you can imagine kind of how crowded and + + + align:start position:0% +you can imagine kind of how crowded and +how disorganized things are as well as + + align:start position:0% +how disorganized things are as well as + + + align:start position:0% +how disorganized things are as well as +infectious risk you have this many + + align:start position:0% +infectious risk you have this many + + + align:start position:0% +infectious risk you have this many +people coming in and out moving around + + align:start position:0% +people coming in and out moving around + + + align:start position:0% +people coming in and out moving around +uh and if you can think of some of the + + align:start position:0% +uh and if you can think of some of the + + + align:start position:0% +uh and if you can think of some of the +errors that can happen here think of the + + align:start position:0% +errors that can happen here think of the + + + align:start position:0% +errors that can happen here think of the +noise that's going on here if someone + + align:start position:0% +noise that's going on here if someone + + + align:start position:0% +noise that's going on here if someone +needs something well I didn't hear you + + align:start position:0% +needs something well I didn't hear you + + + align:start position:0% +needs something well I didn't hear you +because so- and so is yelling over here + + align:start position:0% +because so- and so is yelling over here + + + align:start position:0% +because so- and so is yelling over here +there's just uh it's just a different + + align:start position:0% +there's just uh it's just a different + + + align:start position:0% +there's just uh it's just a different +place and so what we wanted to show is + + align:start position:0% +place and so what we wanted to show is + + + align:start position:0% +place and so what we wanted to show is +in these limited these poor uh regions + + align:start position:0% +in these limited these poor uh regions + + + align:start position:0% +in these limited these poor uh regions +that we could actually implement the + + align:start position:0% +that we could actually implement the + + + align:start position:0% +that we could actually implement the +checklist on a hospital wide basis in + + align:start position:0% +checklist on a hospital wide basis in + + + align:start position:0% +checklist on a hospital wide basis in +addition to that we wanted to show that + + align:start position:0% +addition to that we wanted to show that + + + align:start position:0% +addition to that we wanted to show that +we could actually affect change and we + + align:start position:0% +we could actually affect change and we + + + align:start position:0% +we could actually affect change and we +could bring in these PEX SYM show + + align:start position:0% +could bring in these PEX SYM show + + + align:start position:0% +could bring in these PEX SYM show +difference + + align:start position:0% +difference + + + align:start position:0% +difference +so I'm going to move along quickly uh + + align:start position:0% +so I'm going to move along quickly uh + + + align:start position:0% +so I'm going to move along quickly uh +this is a picture of a pulse oximeter it + + align:start position:0% +this is a picture of a pulse oximeter it + + + align:start position:0% +this is a picture of a pulse oximeter it +shows heart rate as well as oxygen + + align:start position:0% +shows heart rate as well as oxygen + + + align:start position:0% +shows heart rate as well as oxygen +saturation and uh in a study in the + + align:start position:0% +saturation and uh in a study in the + + + align:start position:0% +saturation and uh in a study in the +lanet was published last year um + + align:start position:0% +lanet was published last year um + + + align:start position:0% +lanet was published last year um +evidence showed that in highum countries + + align:start position:0% +evidence showed that in highum countries + + + align:start position:0% +evidence showed that in highum countries +virtually all operating rooms have pulse + + align:start position:0% +virtually all operating rooms have pulse + + + align:start position:0% +virtually all operating rooms have pulse +Symmetry and it's an international + + align:start position:0% +Symmetry and it's an international + + + align:start position:0% +Symmetry and it's an international +standard if you look at all the + + align:start position:0% +standard if you look at all the + + + align:start position:0% +standard if you look at all the +countries that have standards of + + align:start position:0% +countries that have standards of + + + align:start position:0% +countries that have standards of +anesthetic monitoring they're on all the + + align:start position:0% +anesthetic monitoring they're on all the + + + align:start position:0% +anesthetic monitoring they're on all the +monitoring standards um so it's an + + align:start position:0% +monitoring standards um so it's an + + + align:start position:0% +monitoring standards um so it's an +international standard of monitoring + + align:start position:0% +international standard of monitoring + + + align:start position:0% +international standard of monitoring +care but in low-income countries they're + + align:start position:0% +care but in low-income countries they're + + + align:start position:0% +care but in low-income countries they're +absent from more than 50% of those + + align:start position:0% +absent from more than 50% of those + + + align:start position:0% +absent from more than 50% of those +operating rooms and so so our aims were + + align:start position:0% +operating rooms and so so our aims were + + + align:start position:0% +operating rooms and so so our aims were +basically to see if we could bring the + + align:start position:0% +basically to see if we could bring the + + + align:start position:0% +basically to see if we could bring the +checklist in and the PO SYM and show + + align:start position:0% +checklist in and the PO SYM and show + + + align:start position:0% +checklist in and the PO SYM and show +that there was a difference and then to + + align:start position:0% +that there was a difference and then to + + + align:start position:0% +that there was a difference and then to +show the effect of pox symmetry training + + align:start position:0% +show the effect of pox symmetry training + + + align:start position:0% +show the effect of pox symmetry training +and show a trend in Improvement in + + align:start position:0% +and show a trend in Improvement in + + + align:start position:0% +and show a trend in Improvement in +hypoxemia over time and so in addition + + align:start position:0% +hypoxemia over time and so in addition + + + align:start position:0% +hypoxemia over time and so in addition +to these um eight sites we added three + + align:start position:0% +to these um eight sites we added three + + + align:start position:0% +to these um eight sites we added three +more sites one in Honduras one in mova + + align:start position:0% +more sites one in Honduras one in mova + + + align:start position:0% +more sites one in Honduras one in mova +and one in Zambia I'm going to talk + + align:start position:0% +and one in Zambia I'm going to talk + + + align:start position:0% +and one in Zambia I'm going to talk +about mdova and Zambia today because + + align:start position:0% +about mdova and Zambia today because + + + align:start position:0% +about mdova and Zambia today because +we're furthest along there we're still + + align:start position:0% +we're furthest along there we're still + + + align:start position:0% +we're furthest along there we're still +working with Honduras we don't have too + + align:start position:0% +working with Honduras we don't have too + + + align:start position:0% +working with Honduras we don't have too +much information from there yet but uh + + align:start position:0% +much information from there yet but uh + + + align:start position:0% +much information from there yet but uh +speaking about the implementation plan + + align:start position:0% +speaking about the implementation plan + + + align:start position:0% +speaking about the implementation plan +so we this is kind of the schema that we + + align:start position:0% +so we this is kind of the schema that we + + + align:start position:0% +so we this is kind of the schema that we +use to implement it's very basic um + + align:start position:0% +use to implement it's very basic um + + + align:start position:0% +use to implement it's very basic um +there's a lot more detail that goes + + align:start position:0% +there's a lot more detail that goes + + + align:start position:0% +there's a lot more detail that goes +along with it but this is the basic + + align:start position:0% +along with it but this is the basic + + + align:start position:0% +along with it but this is the basic +principles were we wanted a local team + + align:start position:0% +principles were we wanted a local team + + + align:start position:0% +principles were we wanted a local team +to be the implementation team someone a + + align:start position:0% +to be the implementation team someone a + + + align:start position:0% +to be the implementation team someone a +local team to really take charge we + + align:start position:0% +local team to really take charge we + + + align:start position:0% +local team to really take charge we +wanted to provide didactic education as + + align:start position:0% +wanted to provide didactic education as + + + align:start position:0% +wanted to provide didactic education as +well as demonstration we encouraged + + align:start position:0% +well as demonstration we encouraged + + + align:start position:0% +well as demonstration we encouraged +roleplay and then we did coaching and + + align:start position:0% +roleplay and then we did coaching and + + + align:start position:0% +roleplay and then we did coaching and +feedback and so the the thought was at + + align:start position:0% +feedback and so the the thought was at + + + align:start position:0% +feedback and so the the thought was at +the who the the School of Public Health + + align:start position:0% +the who the the School of Public Health + + + align:start position:0% +the who the the School of Public Health +and the World Federation site of + + align:start position:0% +and the World Federation site of + + + align:start position:0% +and the World Federation site of +anesthesiologist we would provide + + align:start position:0% +anesthesiologist we would provide + + + align:start position:0% +anesthesiologist we would provide +oversight to the local implementation as + + align:start position:0% +oversight to the local implementation as + + + align:start position:0% +oversight to the local implementation as +well as the local Administration and + + align:start position:0% +well as the local Administration and + + + align:start position:0% +well as the local Administration and +then they would then take this and teach + + align:start position:0% +then they would then take this and teach + + + align:start position:0% +then they would then take this and teach +it to their operating room staff and + + align:start position:0% +it to their operating room staff and + + + align:start position:0% +it to their operating room staff and +hopefully we'd find change and along + + align:start position:0% +hopefully we'd find change and along + + + align:start position:0% +hopefully we'd find change and along +this kind of the backbone of all this + + align:start position:0% +this kind of the backbone of all this + + + align:start position:0% +this kind of the backbone of all this +was data collection in order to to prove + + align:start position:0% +was data collection in order to to prove + + + align:start position:0% +was data collection in order to to prove +the things we wanted to show we needed + + align:start position:0% +the things we wanted to show we needed + + + align:start position:0% +the things we wanted to show we needed +to have robust data collection and so + + align:start position:0% +to have robust data collection and so + + + align:start position:0% +to have robust data collection and so +through uh funding through the who we + + align:start position:0% +through uh funding through the who we + + + align:start position:0% +through uh funding through the who we +were able to pay for data collectors in + + align:start position:0% +were able to pay for data collectors in + + + align:start position:0% +were able to pay for data collectors in +all these different + + align:start position:0% +all these different + + + align:start position:0% +all these different +areas uh and so this is just a + + align:start position:0% +areas uh and so this is just a + + + align:start position:0% +areas uh and so this is just a +demonstration of how the local + + align:start position:0% +demonstration of how the local + + + align:start position:0% +demonstration of how the local +implementation team taught uh I'll get + + align:start position:0% +implementation team taught uh I'll get + + + align:start position:0% +implementation team taught uh I'll get +you in just a minute so in we we had + + align:start position:0% +you in just a minute so in we we had + + + align:start position:0% +you in just a minute so in we we had +demonstrations as well as right in the + + align:start position:0% +demonstrations as well as right in the + + + align:start position:0% +demonstrations as well as right in the +operating room teaching on how to use a + + align:start position:0% +operating room teaching on how to use a + + + align:start position:0% +operating room teaching on how to use a +checklist we have these big posters + + align:start position:0% +checklist we have these big posters + + + align:start position:0% +checklist we have these big posters +placed on the wall and this is a local + + align:start position:0% +placed on the wall and this is a local + + + align:start position:0% +placed on the wall and this is a local +anesthesiologist teaching nurses about + + align:start position:0% +anesthesiologist teaching nurses about + + + align:start position:0% +anesthesiologist teaching nurses about +the checklist and this here is a surgeon + + align:start position:0% +the checklist and this here is a surgeon + + + align:start position:0% +the checklist and this here is a surgeon +teaching uh the anestis how to use a + + align:start position:0% +teaching uh the anestis how to use a + + + align:start position:0% +teaching uh the anestis how to use a +checklist quick question here the total + + align:start position:0% +checklist quick question here the total + + + align:start position:0% +checklist quick question here the total +budget for this uh so it's uh it's about + + align:start position:0% +budget for this uh so it's uh it's about + + + align:start position:0% +budget for this uh so it's uh it's about +30,000 per site so not 30,000 per site + + align:start position:0% +30,000 per site so not 30,000 per site + + + align:start position:0% +30,000 per site so not 30,000 per site +correct and so you might think that's a + + align:start position:0% +correct and so you might think that's a + + + align:start position:0% +correct and so you might think that's a +lot that's a lot to me but um if you + + align:start position:0% +lot that's a lot to me but um if you + + + align:start position:0% +lot that's a lot to me but um if you +consider the amount of uh data + + align:start position:0% +consider the amount of uh data + + + align:start position:0% +consider the amount of uh data +collection that occurred and and uh the + + align:start position:0% +collection that occurred and and uh the + + + align:start position:0% +collection that occurred and and uh the +resources used it was actually as + + align:start position:0% +resources used it was actually as + + + align:start position:0% +resources used it was actually as +studies go quite a lowbudget + + align:start position:0% + + + + align:start position:0% + +study and so these are some of the + + align:start position:0% +study and so these are some of the + + + align:start position:0% +study and so these are some of the +results we see in Moldova this is just + + align:start position:0% +results we see in Moldova this is just + + + align:start position:0% +results we see in Moldova this is just +one of the sites we haven't quite seen + + align:start position:0% +one of the sites we haven't quite seen + + + align:start position:0% +one of the sites we haven't quite seen +significant differences in death yet and + + align:start position:0% +significant differences in death yet and + + + align:start position:0% +significant differences in death yet and +mortality but there's a trend from 4% to + + align:start position:0% +mortality but there's a trend from 4% to + + + align:start position:0% +mortality but there's a trend from 4% to +3.6% complication rates have gone down + + align:start position:0% +3.6% complication rates have gone down + + + align:start position:0% +3.6% complication rates have gone down +by almost 60% surgical s infection also + + align:start position:0% +by almost 60% surgical s infection also + + + align:start position:0% +by almost 60% surgical s infection also +almost about 60% % pneumonia has + + align:start position:0% +almost about 60% % pneumonia has + + + align:start position:0% +almost about 60% % pneumonia has +decreased by almost uh from 4.7 to 2.9% + + align:start position:0% +decreased by almost uh from 4.7 to 2.9% + + + align:start position:0% +decreased by almost uh from 4.7 to 2.9% +and unplanned intubation has also + + align:start position:0% +and unplanned intubation has also + + + align:start position:0% +and unplanned intubation has also +decreased and so some of this I think + + align:start position:0% +decreased and so some of this I think + + + align:start position:0% +decreased and so some of this I think +we've seen before any complications cgal + + align:start position:0% +we've seen before any complications cgal + + + align:start position:0% +we've seen before any complications cgal +site infections but things that are a + + align:start position:0% +site infections but things that are a + + + align:start position:0% +site infections but things that are a +little bit different that I think are + + align:start position:0% +little bit different that I think are + + + align:start position:0% +little bit different that I think are +added by the pulse sumers are the need + + align:start position:0% +added by the pulse sumers are the need + + + align:start position:0% +added by the pulse sumers are the need +to the prevention of unplanned + + align:start position:0% +to the prevention of unplanned + + + align:start position:0% +to the prevention of unplanned +intubations as well as maybe maybe + + align:start position:0% +intubations as well as maybe maybe + + + align:start position:0% +intubations as well as maybe maybe +pneumonia uh but I think um we're seeing + + align:start position:0% +pneumonia uh but I think um we're seeing + + + align:start position:0% +pneumonia uh but I think um we're seeing +the same thing we're seeing a reduction + + align:start position:0% +the same thing we're seeing a reduction + + + align:start position:0% +the same thing we're seeing a reduction +in complications overall by using the + + align:start position:0% +in complications overall by using the + + + align:start position:0% +in complications overall by using the +checklist + + align:start position:0% +checklist + + + align:start position:0% +checklist +uh here's a uh some figure a figure + + align:start position:0% +uh here's a uh some figure a figure + + + align:start position:0% +uh here's a uh some figure a figure +showing the the uh decrease in hypoxemic + + align:start position:0% +showing the the uh decrease in hypoxemic + + + align:start position:0% +showing the the uh decrease in hypoxemic +episodes per thousand oximetry hours so + + align:start position:0% +episodes per thousand oximetry hours so + + + align:start position:0% +episodes per thousand oximetry hours so +the bars in blue are periods where + + align:start position:0% +the bars in blue are periods where + + + align:start position:0% +the bars in blue are periods where +someone's oxygen level is just marginal + + align:start position:0% +someone's oxygen level is just marginal + + + align:start position:0% +someone's oxygen level is just marginal +from less than + + align:start position:0% +from less than + + + align:start position:0% +from less than +90 uh and you can see this sharp + + align:start position:0% +90 uh and you can see this sharp + + + align:start position:0% +90 uh and you can see this sharp +decrease from the early period to the + + align:start position:0% +decrease from the early period to the + + + align:start position:0% +decrease from the early period to the +middle period and then again just a + + align:start position:0% +middle period and then again just a + + + align:start position:0% +middle period and then again just a +little bit more from the late period the + + align:start position:0% +little bit more from the late period the + + + align:start position:0% +little bit more from the late period the +other thing we wanted to catch was to + + align:start position:0% +other thing we wanted to catch was to + + + align:start position:0% +other thing we wanted to catch was to +see well if people are having low oxygen + + align:start position:0% +see well if people are having low oxygen + + + align:start position:0% +see well if people are having low oxygen +levels uh what if they're are we + + align:start position:0% +levels uh what if they're are we + + + align:start position:0% +levels uh what if they're are we +preventing the the severity of the those + + align:start position:0% +preventing the the severity of the those + + + align:start position:0% +preventing the the severity of the those +low uh low oxygen levels uh so we looked + + align:start position:0% +low uh low oxygen levels uh so we looked + + + align:start position:0% +low uh low oxygen levels uh so we looked +at four minutes as well so if someone's + + align:start position:0% +at four minutes as well so if someone's + + + align:start position:0% +at four minutes as well so if someone's +having a a greater than 4 minute period + + align:start position:0% +having a a greater than 4 minute period + + + align:start position:0% +having a a greater than 4 minute period +of hypoxia that would be what we + + align:start position:0% +of hypoxia that would be what we + + + align:start position:0% +of hypoxia that would be what we +consider severe episode and so those + + align:start position:0% +consider severe episode and so those + + + align:start position:0% +consider severe episode and so those +have also gone down so not only we've + + align:start position:0% +have also gone down so not only we've + + + align:start position:0% +have also gone down so not only we've +been able to decrease the amount of + + align:start position:0% +been able to decrease the amount of + + + align:start position:0% +been able to decrease the amount of +hypoxemia in general but also the + + align:start position:0% +hypoxemia in general but also the + + + align:start position:0% +hypoxemia in general but also the +severity of the hyp + + align:start position:0% + + + + align:start position:0% + +hypoxemia how does it differ from we + + align:start position:0% +hypoxemia how does it differ from we + + + align:start position:0% +hypoxemia how does it differ from we +have the United States you know I uh so + + align:start position:0% +have the United States you know I uh so + + + align:start position:0% +have the United States you know I uh so +the number of + + align:start position:0% +the number of + + + align:start position:0% +the number of +hypoxemia I don't have the numbers right + + align:start position:0% +hypoxemia I don't have the numbers right + + + align:start position:0% +hypoxemia I don't have the numbers right +off the top of my head but it's less + + align:start position:0% +off the top of my head but it's less + + + align:start position:0% +off the top of my head but it's less +than 1% really for uh and I don't I + + align:start position:0% +than 1% really for uh and I don't I + + + align:start position:0% +than 1% really for uh and I don't I +don't have it broken + + align:start position:0% +don't have it broken + + + align:start position:0% +don't have it broken +down so I would say that the rate of + + align:start position:0% +down so I would say that the rate of + + + align:start position:0% +down so I would say that the rate of +hypoxemia is twice that of here in the + + align:start position:0% +hypoxemia is twice that of here in the + + + align:start position:0% +hypoxemia is twice that of here in the +United States there there's a recent + + align:start position:0% +United States there there's a recent + + + align:start position:0% +United States there there's a recent +study that looked at um actually the MGH + + align:start position:0% +study that looked at um actually the MGH + + + align:start position:0% +study that looked at um actually the MGH +and a tertiary Hospital in Auckland New + + align:start position:0% +and a tertiary Hospital in Auckland New + + + align:start position:0% +and a tertiary Hospital in Auckland New +Zealand and so we considering those as + + align:start position:0% +Zealand and so we considering those as + + + align:start position:0% +Zealand and so we considering those as +high income countries their rates of + + align:start position:0% +high income countries their rates of + + + align:start position:0% +high income countries their rates of +hypoxemia were about half of what we see + + align:start position:0% +hypoxemia were about half of what we see + + + align:start position:0% +hypoxemia were about half of what we see +here in mdova + + align:start position:0% + + + + align:start position:0% + +and so this is the schema we're hoping + + align:start position:0% +and so this is the schema we're hoping + + + align:start position:0% +and so this is the schema we're hoping +to show that check we know that + + align:start position:0% +to show that check we know that + + + align:start position:0% +to show that check we know that +checklist can save lives we know that + + align:start position:0% +checklist can save lives we know that + + + align:start position:0% +checklist can save lives we know that +puls symmetry is essential to Safe + + align:start position:0% +puls symmetry is essential to Safe + + + align:start position:0% +puls symmetry is essential to Safe +surgery uh implementation we hope we've + + align:start position:0% +surgery uh implementation we hope we've + + + align:start position:0% +surgery uh implementation we hope we've +shown that they can implementation of + + align:start position:0% +shown that they can implementation of + + + align:start position:0% +shown that they can implementation of +this this package uh improves outcomes + + align:start position:0% +this this package uh improves outcomes + + + align:start position:0% +this this package uh improves outcomes +and then lastly um we hope that this can + + align:start position:0% +and then lastly um we hope that this can + + + align:start position:0% +and then lastly um we hope that this can +become a universal + + align:start position:0% +become a universal + + + align:start position:0% +become a universal +standard so we're going to move on uh + + align:start position:0% +standard so we're going to move on uh + + + align:start position:0% +standard so we're going to move on uh +thank you very + + align:start position:0% +thank you very + + + align:start position:0% +thank you very +much long if you for + + align:start position:0% +much long if you for + + + align:start position:0% +much long if you for +how long + + align:start position:0% + + + + align:start position:0% + +do yeah it's a it's a machine that they + + align:start position:0% +do yeah it's a it's a machine that they + + + align:start position:0% +do yeah it's a it's a machine that they +can use till till it breaks uh but we uh + + align:start position:0% +can use till till it breaks uh but we uh + + + align:start position:0% +can use till till it breaks uh but we uh +we didn't feel like it was right to take + + align:start position:0% +we didn't feel like it was right to take + + + align:start position:0% +we didn't feel like it was right to take +them there and take them away so we've + + align:start position:0% +them there and take them away so we've + + + align:start position:0% +them there and take them away so we've +all the sites we've gone to are are + + align:start position:0% +all the sites we've gone to are are + + + align:start position:0% +all the sites we've gone to are are +we've left the oximeters there with + + align:start position:0% +we've left the oximeters there with + + + align:start position:0% +we've left the oximeters there with +replacement probes for them to + + align:start position:0% + + + + align:start position:0% + +use so Alvin talked about his experience + + align:start position:0% +use so Alvin talked about his experience + + + align:start position:0% +use so Alvin talked about his experience +of the use of safe surgery checklist and + + align:start position:0% +of the use of safe surgery checklist and + + + align:start position:0% +of the use of safe surgery checklist and +surgery and then also the implementation + + align:start position:0% +surgery and then also the implementation + + + align:start position:0% +surgery and then also the implementation +and what you'll notice on his first + + align:start position:0% +and what you'll notice on his first + + + align:start position:0% +and what you'll notice on his first +slide it said the who safe surgery + + align:start position:0% +slide it said the who safe surgery + + + align:start position:0% +slide it said the who safe surgery +checklist and we quickly realize that + + align:start position:0% +checklist and we quickly realize that + + + align:start position:0% +checklist and we quickly realize that +you can't just drop checklists over + + align:start position:0% +you can't just drop checklists over + + + align:start position:0% +you can't just drop checklists over +subsaharan Africa and Asia and hope + + align:start position:0% +subsaharan Africa and Asia and hope + + + align:start position:0% +subsaharan Africa and Asia and hope +that'll function and have the impact and + + align:start position:0% +that'll function and have the impact and + + + align:start position:0% +that'll function and have the impact and +so you'll see on my slide it says the + + align:start position:0% +so you'll see on my slide it says the + + + align:start position:0% +so you'll see on my slide it says the +safe child birth checklist program + + align:start position:0% +safe child birth checklist program + + + align:start position:0% +safe child birth checklist program +because as you all know having the + + align:start position:0% +because as you all know having the + + + align:start position:0% +because as you all know having the +technology on its own isn't going to + + align:start position:0% +technology on its own isn't going to + + + align:start position:0% +technology on its own isn't going to +work you need to have some kind of + + align:start position:0% +work you need to have some kind of + + + align:start position:0% +work you need to have some kind of +supportive element however skinny that + + align:start position:0% +supportive element however skinny that + + + align:start position:0% +supportive element however skinny that +element is + + align:start position:0% +element is + + + align:start position:0% +element is +so I'm going to take us to a different + + align:start position:0% +so I'm going to take us to a different + + + align:start position:0% +so I'm going to take us to a different +scenario and I'm actually going to focus + + align:start position:0% +scenario and I'm actually going to focus + + + align:start position:0% +scenario and I'm actually going to focus +on the early stages because when we came + + align:start position:0% +on the early stages because when we came + + + align:start position:0% +on the early stages because when we came +when I entered there was no checklist we + + align:start position:0% +when I entered there was no checklist we + + + align:start position:0% +when I entered there was no checklist we +had to actually create the checklist so + + align:start position:0% +had to actually create the checklist so + + + align:start position:0% +had to actually create the checklist so +I'm going to talk about the development + + align:start position:0% +I'm going to talk about the development + + + align:start position:0% +I'm going to talk about the development +of the checklist bit more than the + + align:start position:0% +of the checklist bit more than the + + + align:start position:0% +of the checklist bit more than the +implementation of it so what are the + + align:start position:0% +implementation of it so what are the + + + align:start position:0% +implementation of it so what are the +principles the purpose is to ensure that + + align:start position:0% +principles the purpose is to ensure that + + + align:start position:0% +principles the purpose is to ensure that +essential care practices are reliably + + align:start position:0% +essential care practices are reliably + + + align:start position:0% +essential care practices are reliably +performed that's doing the right thing + + align:start position:0% +performed that's doing the right thing + + + align:start position:0% +performed that's doing the right thing +to the right patient at the right time + + align:start position:0% +to the right patient at the right time + + + align:start position:0% +to the right patient at the right time +every single time it has to be + + align:start position:0% +every single time it has to be + + + align:start position:0% +every single time it has to be +evidence-based so there is nothing + + align:start position:0% +evidence-based so there is nothing + + + align:start position:0% +evidence-based so there is nothing +nothing new on any of these checklists + + align:start position:0% +nothing new on any of these checklists + + + align:start position:0% +nothing new on any of these checklists +The Innovation is the tool so you're + + align:start position:0% +The Innovation is the tool so you're + + + align:start position:0% +The Innovation is the tool so you're +actually providing good care at the + + align:start position:0% +actually providing good care at the + + + align:start position:0% +actually providing good care at the +bedside it's not the items on the + + align:start position:0% +bedside it's not the items on the + + + align:start position:0% +bedside it's not the items on the +checklist and that's important for + + align:start position:0% +checklist and that's important for + + + align:start position:0% +checklist and that's important for +acceptability later on in the process + + align:start position:0% +acceptability later on in the process + + + align:start position:0% +acceptability later on in the process +then succinct and simple everyone wants + + align:start position:0% +then succinct and simple everyone wants + + + align:start position:0% +then succinct and simple everyone wants +to add items onto the checklist the more + + align:start position:0% +to add items onto the checklist the more + + + align:start position:0% +to add items onto the checklist the more +items you add on the longer it takes and + + align:start position:0% +items you add on the longer it takes and + + + align:start position:0% +items you add on the longer it takes and +the field that we're working in high + + align:start position:0% +the field that we're working in high + + + align:start position:0% +the field that we're working in high +burden sort of in the developing World + + align:start position:0% +burden sort of in the developing World + + + align:start position:0% +burden sort of in the developing World +they already have a shortage of + + align:start position:0% +they already have a shortage of + + + align:start position:0% +they already have a shortage of +healthcare workers they don't have time + + align:start position:0% +healthcare workers they don't have time + + + align:start position:0% +healthcare workers they don't have time +so everything on it must be absolutely + + align:start position:0% +so everything on it must be absolutely + + + align:start position:0% +so everything on it must be absolutely +mandatory and affects mortality or + + align:start position:0% +mandatory and affects mortality or + + + align:start position:0% +mandatory and affects mortality or +severe + + align:start position:0% +severe + + + align:start position:0% +severe +morbidity and it's a bedside tool you + + align:start position:0% +morbidity and it's a bedside tool you + + + align:start position:0% +morbidity and it's a bedside tool you +want something to be easy to use at the + + align:start position:0% +want something to be easy to use at the + + + align:start position:0% +want something to be easy to use at the +bedside broad applicability you ask that + + align:start position:0% +bedside broad applicability you ask that + + + align:start position:0% +bedside broad applicability you ask that +question you know is this for Africa is + + align:start position:0% +question you know is this for Africa is + + + align:start position:0% +question you know is this for Africa is +this for the US um it's important for + + align:start position:0% +this for the US um it's important for + + + align:start position:0% +this for the US um it's important for +scale up that every item is essential + + align:start position:0% +scale up that every item is essential + + + align:start position:0% +scale up that every item is essential +and therefore should be done all over + + align:start position:0% +and therefore should be done all over + + + align:start position:0% +and therefore should be done all over +the world so when we were in the middle + + align:start position:0% +the world so when we were in the middle + + + align:start position:0% +the world so when we were in the middle +of the development the other person + + align:start position:0% +of the development the other person + + + align:start position:0% +of the development the other person +that's working with me is a + + align:start position:0% +that's working with me is a + + + align:start position:0% +that's working with me is a +neonatologist and um he his wife was + + align:start position:0% +neonatologist and um he his wife was + + + align:start position:0% +neonatologist and um he his wife was +having his first baby at Beth Israel + + align:start position:0% +having his first baby at Beth Israel + + + align:start position:0% +having his first baby at Beth Israel +very good Hospital in Boston and he'd + + align:start position:0% +very good Hospital in Boston and he'd + + + align:start position:0% +very good Hospital in Boston and he'd +forgotten about it throughout the whole + + align:start position:0% +forgotten about it throughout the whole + + + align:start position:0% +forgotten about it throughout the whole +process of having the baby because he + + align:start position:0% +process of having the baby because he + + + align:start position:0% +process of having the baby because he +was so traumatized but then at the end + + align:start position:0% +was so traumatized but then at the end + + + align:start position:0% +was so traumatized but then at the end +he was like oh I have the checklist took + + align:start position:0% +he was like oh I have the checklist took + + + align:start position:0% +he was like oh I have the checklist took +it out the back of his pocket I was like + + align:start position:0% +it out the back of his pocket I was like + + + align:start position:0% +it out the back of his pocket I was like +okay so have they done the things that + + align:start position:0% +okay so have they done the things that + + + align:start position:0% +okay so have they done the things that +they should have done after delivery and + + align:start position:0% +they should have done after delivery and + + + align:start position:0% +they should have done after delivery and +no they hadn't they' missed two items + + align:start position:0% +no they hadn't they' missed two items + + + align:start position:0% +no they hadn't they' missed two items +one was they hadn't got the + + align:start position:0% +one was they hadn't got the + + + align:start position:0% +one was they hadn't got the +breastfeeding going within an hour which + + align:start position:0% +breastfeeding going within an hour which + + + align:start position:0% +breastfeeding going within an hour which +we know should be done and second they + + align:start position:0% +we know should be done and second they + + + align:start position:0% +we know should be done and second they +hadn't checked the temperature of the + + align:start position:0% +hadn't checked the temperature of the + + + align:start position:0% +hadn't checked the temperature of the +baby his baby was hypothermic had a + + align:start position:0% +baby his baby was hypothermic had a + + + align:start position:0% +baby his baby was hypothermic had a +lower temperature than it should have + + align:start position:0% +lower temperature than it should have + + + align:start position:0% +lower temperature than it should have +and it's fine we're in America put it on + + align:start position:0% +and it's fine we're in America put it on + + + align:start position:0% +and it's fine we're in America put it on +the heat be fine but that wouldn't have + + align:start position:0% +the heat be fine but that wouldn't have + + + align:start position:0% +the heat be fine but that wouldn't have +happened in Africa um so it should be + + align:start position:0% +happened in Africa um so it should be + + + align:start position:0% +happened in Africa um so it should be +applicable all over and then the + + align:start position:0% +applicable all over and then the + + + align:start position:0% +applicable all over and then the +capacity for measurable impact like you + + align:start position:0% +capacity for measurable impact like you + + + align:start position:0% +capacity for measurable impact like you +said if you can't prove meaningful + + align:start position:0% +said if you can't prove meaningful + + + align:start position:0% +said if you can't prove meaningful +change you won't build program support + + align:start position:0% +change you won't build program support + + + align:start position:0% +change you won't build program support +especially in medical areas where people + + align:start position:0% +especially in medical areas where people + + + align:start position:0% +especially in medical areas where people +want to know what they're doing has an + + align:start position:0% +want to know what they're doing has an + + + align:start position:0% +want to know what they're doing has an +Evidence base show me the numbers yeah + + align:start position:0% +Evidence base show me the numbers yeah + + + align:start position:0% +Evidence base show me the numbers yeah +and so you have to be able to measure + + align:start position:0% +and so you have to be able to measure + + + align:start position:0% +and so you have to be able to measure +what um impact you're having it's not + + align:start position:0% +what um impact you're having it's not + + + align:start position:0% +what um impact you're having it's not +comprehensive this checklist is not to + + align:start position:0% +comprehensive this checklist is not to + + + align:start position:0% +comprehensive this checklist is not to +prevent every conceivable patient harm + + align:start position:0% +prevent every conceivable patient harm + + + align:start position:0% +prevent every conceivable patient harm +it's focused on the Big Bang you know + + align:start position:0% +it's focused on the Big Bang you know + + + align:start position:0% +it's focused on the Big Bang you know +the mortality and the severe morbidity + + align:start position:0% +the mortality and the severe morbidity + + + align:start position:0% +the mortality and the severe morbidity +and it's not a protocol or guideline so + + align:start position:0% +and it's not a protocol or guideline so + + + align:start position:0% +and it's not a protocol or guideline so +people were like oh okay so this is what + + align:start position:0% +people were like oh okay so this is what + + + align:start position:0% +people were like oh okay so this is what +I do to deliver a baby no no you need to + + align:start position:0% +I do to deliver a baby no no you need to + + + align:start position:0% +I do to deliver a baby no no you need to +have training and you need to be able to + + align:start position:0% +have training and you need to be able to + + + align:start position:0% +have training and you need to be able to +know what to do so it's a bit like a + + align:start position:0% +know what to do so it's a bit like a + + + align:start position:0% +know what to do so it's a bit like a +shopping list you give your know partner + + align:start position:0% +shopping list you give your know partner + + + align:start position:0% +shopping list you give your know partner +a shopping list go and get tomatoes you + + align:start position:0% +a shopping list go and get tomatoes you + + + align:start position:0% +a shopping list go and get tomatoes you +don't tell them how to pick the tomatoes + + align:start position:0% +don't tell them how to pick the tomatoes + + + align:start position:0% +don't tell them how to pick the tomatoes +you just say I need some tomatoes and + + align:start position:0% +you just say I need some tomatoes and + + + align:start position:0% +you just say I need some tomatoes and +same with the pilot checklist you can't + + align:start position:0% +same with the pilot checklist you can't + + + align:start position:0% +same with the pilot checklist you can't +say oh well you don't need pilot + + align:start position:0% +say oh well you don't need pilot + + + align:start position:0% +say oh well you don't need pilot +training they're just + + align:start position:0% +training they're just + + + align:start position:0% +training they're just +reminders so we've sort of got a a bit + + align:start position:0% +reminders so we've sort of got a a bit + + + align:start position:0% +reminders so we've sort of got a a bit +of a schema on checklist development and + + align:start position:0% +of a schema on checklist development and + + + align:start position:0% +of a schema on checklist development and +then checklist testing and so it's + + align:start position:0% +then checklist testing and so it's + + + align:start position:0% +then checklist testing and so it's +assembling the evidence on critical + + align:start position:0% +assembling the evidence on critical + + + align:start position:0% +assembling the evidence on critical +omissions that will lead to harm then + + align:start position:0% +omissions that will lead to harm then + + + align:start position:0% +omissions that will lead to harm then +identifying the pause points and + + align:start position:0% +identifying the pause points and + + + align:start position:0% +identifying the pause points and +actually drafting the checklist items + + align:start position:0% +actually drafting the checklist items + + + align:start position:0% +actually drafting the checklist items +this actually Boeing and the aviation + + align:start position:0% +this actually Boeing and the aviation + + + align:start position:0% +this actually Boeing and the aviation +industry spend a lot of time on this and + + align:start position:0% +industry spend a lot of time on this and + + + align:start position:0% +industry spend a lot of time on this and +we got them to help us both with the + + align:start position:0% +we got them to help us both with the + + + align:start position:0% +we got them to help us both with the +safe surgery checklist and with the safe + + align:start position:0% +safe surgery checklist and with the safe + + + align:start position:0% +safe surgery checklist and with the safe +child birth checklist and this guy his + + align:start position:0% +child birth checklist and this guy his + + + align:start position:0% +child birth checklist and this guy his +name is Dan Borman this is his sort of + + align:start position:0% +name is Dan Borman this is his sort of + + + align:start position:0% +name is Dan Borman this is his sort of +what he does in life he's like this has + + align:start position:0% +what he does in life he's like this has + + + align:start position:0% +what he does in life he's like this has +to be the font this should be the size + + align:start position:0% +to be the font this should be the size + + + align:start position:0% +to be the font this should be the size +put your action item at the front of the + + align:start position:0% +put your action item at the front of the + + + align:start position:0% +put your action item at the front of the +sentence and all these things matter he + + align:start position:0% +sentence and all these things matter he + + + align:start position:0% +sentence and all these things matter he +like when people are doing this quickly + + align:start position:0% +like when people are doing this quickly + + + align:start position:0% +like when people are doing this quickly +they your wording needs to be + + align:start position:0% +they your wording needs to be + + + align:start position:0% +they your wording needs to be +perfect and then the next process which + + align:start position:0% +perfect and then the next process which + + + align:start position:0% +perfect and then the next process which +is an iterative process getting experts + + align:start position:0% +is an iterative process getting experts + + + align:start position:0% +is an iterative process getting experts +and field users it's actually pretty + + align:start position:0% +and field users it's actually pretty + + + align:start position:0% +and field users it's actually pretty +painful um but it's hugely important for + + align:start position:0% +painful um but it's hugely important for + + + align:start position:0% +painful um but it's hugely important for +scale up later on so quick story on this + + align:start position:0% +scale up later on so quick story on this + + + align:start position:0% +scale up later on so quick story on this +um we had an international consultation + + align:start position:0% +um we had an international consultation + + + align:start position:0% +um we had an international consultation +because it's a who thing so you have to + + align:start position:0% +because it's a who thing so you have to + + + align:start position:0% +because it's a who thing so you have to +have international consultation who's + + align:start position:0% +have international consultation who's + + + align:start position:0% +have international consultation who's +who of Safe child birth in in the room + + align:start position:0% +who of Safe child birth in in the room + + + align:start position:0% +who of Safe child birth in in the room +the first comment was that the neologist + + align:start position:0% +the first comment was that the neologist + + + align:start position:0% +the first comment was that the neologist +and the obstetrician sat there and said + + align:start position:0% +and the obstetrician sat there and said + + + align:start position:0% +and the obstetrician sat there and said +we've never been in the same room for an + + align:start position:0% +we've never been in the same room for an + + + align:start position:0% +we've never been in the same room for an +intervention day one of baby has always + + align:start position:0% +intervention day one of baby has always + + + align:start position:0% +intervention day one of baby has always +been argued over the Obstetricians will + + align:start position:0% +been argued over the Obstetricians will + + + align:start position:0% +been argued over the Obstetricians will +say it's mine and the neologist say it's + + align:start position:0% +say it's mine and the neologist say it's + + + align:start position:0% +say it's mine and the neologist say it's +mine and they've just never come + + align:start position:0% +mine and they've just never come + + + align:start position:0% +mine and they've just never come +together um which to being a surgeon + + align:start position:0% +together um which to being a surgeon + + + align:start position:0% +together um which to being a surgeon +like what the hell's going on here um + + align:start position:0% +like what the hell's going on here um + + + align:start position:0% +like what the hell's going on here um +and then he sat there and I really like + + align:start position:0% +and then he sat there and I really like + + + align:start position:0% +and then he sat there and I really like +the way he navigated the process there + + align:start position:0% +the way he navigated the process there + + + align:start position:0% +the way he navigated the process there +was controversy over everything you know + + align:start position:0% +was controversy over everything you know + + + align:start position:0% +was controversy over everything you know +one academic said no for PPH we should + + align:start position:0% +one academic said no for PPH we should + + + align:start position:0% +one academic said no for PPH we should +be doing this and someone else said this + + align:start position:0% +be doing this and someone else said this + + + align:start position:0% +be doing this and someone else said this +and like oh my God I have two days and + + align:start position:0% +and like oh my God I have two days and + + + align:start position:0% +and like oh my God I have two days and +we need to have a draft checklist at the + + align:start position:0% +we need to have a draft checklist at the + + + align:start position:0% +we need to have a draft checklist at the +end but I said you know what's going on + + align:start position:0% +end but I said you know what's going on + + + align:start position:0% +end but I said you know what's going on +like we're not really seeming to get + + align:start position:0% +like we're not really seeming to get + + + align:start position:0% +like we're not really seeming to get +anywhere and he said prya we have to + + align:start position:0% +anywhere and he said prya we have to + + + align:start position:0% +anywhere and he said prya we have to +have the controversial topics coming out + + align:start position:0% +have the controversial topics coming out + + + align:start position:0% +have the controversial topics coming out +now because you don't want them coming + + align:start position:0% +now because you don't want them coming + + + align:start position:0% +now because you don't want them coming +out halfway through your testing and I + + align:start position:0% +out halfway through your testing and I + + + align:start position:0% +out halfway through your testing and I +think that's critical like know your + + align:start position:0% +think that's critical like know your + + + align:start position:0% +think that's critical like know your +landscape whichever intervention + + align:start position:0% +landscape whichever intervention + + + align:start position:0% +landscape whichever intervention +Innovation you're creating and it was + + align:start position:0% +Innovation you're creating and it was + + + align:start position:0% +Innovation you're creating and it was +really important for buying the other + + align:start position:0% +really important for buying the other + + + align:start position:0% +really important for buying the other +thing was that yes we had all the + + align:start position:0% +thing was that yes we had all the + + + align:start position:0% +thing was that yes we had all the +academics but we also had field users we + + align:start position:0% +academics but we also had field users we + + + align:start position:0% +academics but we also had field users we +had the midwives from Kenya and Tanzania + + align:start position:0% +had the midwives from Kenya and Tanzania + + + align:start position:0% +had the midwives from Kenya and Tanzania +Etc and when the academics were fighting + + align:start position:0% +Etc and when the academics were fighting + + + align:start position:0% +Etc and when the academics were fighting +over + + align:start position:0% +over + + + align:start position:0% +over +myi and then they were saying well maybe + + align:start position:0% +myi and then they were saying well maybe + + + align:start position:0% +myi and then they were saying well maybe +we shouldn't have a checklist you know + + align:start position:0% +we shouldn't have a checklist you know + + + align:start position:0% +we shouldn't have a checklist you know +we can't really decide what should be on + + align:start position:0% +we can't really decide what should be on + + + align:start position:0% +we can't really decide what should be on +the checklist I remember the Kenyan + + align:start position:0% +the checklist I remember the Kenyan + + + align:start position:0% +the checklist I remember the Kenyan +Midwife stood up and said just this + + align:start position:0% +Midwife stood up and said just this + + + align:start position:0% +Midwife stood up and said just this +draft this like draft prototype number + + align:start position:0% +draft this like draft prototype number + + + align:start position:0% +draft this like draft prototype number +one can I photocopy it and take it + + align:start position:0% +one can I photocopy it and take it + + + align:start position:0% +one can I photocopy it and take it +because this will make a real difference + + align:start position:0% +because this will make a real difference + + + align:start position:0% +because this will make a real difference +and actually this happened over the + + align:start position:0% +and actually this happened over the + + + align:start position:0% +and actually this happened over the +process you know we had a WebEx later on + + align:start position:0% +process you know we had a WebEx later on + + + align:start position:0% +process you know we had a WebEx later on +in the process and again it was midwives + + align:start position:0% +in the process and again it was midwives + + + align:start position:0% +in the process and again it was midwives +on the front line saying I don't really + + align:start position:0% +on the front line saying I don't really + + + align:start position:0% +on the front line saying I don't really +care about the minui I just want to + + align:start position:0% +care about the minui I just want to + + + align:start position:0% +care about the minui I just want to +start using this because I know it will + + align:start position:0% +start using this because I know it will + + + align:start position:0% +start using this because I know it will +make a + + align:start position:0% +make a + + + align:start position:0% +make a +difference so the next stage now this + + align:start position:0% +difference so the next stage now this + + + align:start position:0% +difference so the next stage now this +was squashed for the safe surgery they + + align:start position:0% +was squashed for the safe surgery they + + + align:start position:0% +was squashed for the safe surgery they +had eight sites and they sort of did the + + align:start position:0% +had eight sites and they sort of did the + + + align:start position:0% +had eight sites and they sort of did the +pilot study for the safe child birth we + + align:start position:0% +pilot study for the safe child birth we + + + align:start position:0% +pilot study for the safe child birth we +uh separated it so we have a pilot study + + align:start position:0% +uh separated it so we have a pilot study + + + align:start position:0% +uh separated it so we have a pilot study +which I'll talk about briefly if I can + + align:start position:0% +which I'll talk about briefly if I can + + + align:start position:0% +which I'll talk about briefly if I can +get rid of the frog in my throat in + + align:start position:0% +get rid of the frog in my throat in + + + align:start position:0% +get rid of the frog in my throat in +India which is just one Center and then + + align:start position:0% +India which is just one Center and then + + + align:start position:0% +India which is just one Center and then +we're moving on to the randomized + + align:start position:0% +we're moving on to the randomized + + + align:start position:0% +we're moving on to the randomized +control trial because academics want the + + align:start position:0% +control trial because academics want the + + + align:start position:0% +control trial because academics want the +randomized control trial to prove that + + align:start position:0% +randomized control trial to prove that + + + align:start position:0% +randomized control trial to prove that +it has an impact on mortality so we see + + align:start position:0% +it has an impact on mortality so we see + + + align:start position:0% +it has an impact on mortality so we see +as the first step is is there + + align:start position:0% +as the first step is is there + + + align:start position:0% +as the first step is is there +Improvement in processes and then the + + align:start position:0% +Improvement in processes and then the + + + align:start position:0% +Improvement in processes and then the +second step is does this Improvement in + + align:start position:0% +second step is does this Improvement in + + + align:start position:0% +second step is does this Improvement in +process lead to reduced number of deaths + + align:start position:0% +process lead to reduced number of deaths + + + align:start position:0% +process lead to reduced number of deaths +now dissemination seems to be falling + + align:start position:0% +now dissemination seems to be falling + + + align:start position:0% +now dissemination seems to be falling +off the slide but actually it's where + + align:start position:0% +off the slide but actually it's where + + + align:start position:0% +off the slide but actually it's where +who sits and I think dissemination is + + align:start position:0% +who sits and I think dissemination is + + + align:start position:0% +who sits and I think dissemination is +something you need to think about right + + align:start position:0% +something you need to think about right + + + align:start position:0% +something you need to think about right +at the beginning of your process and + + align:start position:0% +at the beginning of your process and + + + align:start position:0% +at the beginning of your process and +through the process I've been thinking + + align:start position:0% +through the process I've been thinking + + + align:start position:0% +through the process I've been thinking +why did we start working with wh + + align:start position:0% +why did we start working with wh + + + align:start position:0% +why did we start working with wh +actually they are critical for when the + + align:start position:0% +actually they are critical for when the + + + align:start position:0% +actually they are critical for when the +tools been proven to disseminate across + + align:start position:0% +tools been proven to disseminate across + + + align:start position:0% +tools been proven to disseminate across +the world and so even though it was + + align:start position:0% +the world and so even though it was + + + align:start position:0% +the world and so even though it was +painful working with them at times they + + align:start position:0% +painful working with them at times they + + + align:start position:0% +painful working with them at times they +are now crucial for getting the message + + align:start position:0% +are now crucial for getting the message + + + align:start position:0% +are now crucial for getting the message +out um and if anyone has ideas for where + + align:start position:0% +out um and if anyone has ideas for where + + + align:start position:0% +out um and if anyone has ideas for where +we can put the safe child with checklist + + align:start position:0% +we can put the safe child with checklist + + + align:start position:0% +we can put the safe child with checklist +in terms of a good program then let me + + align:start position:0% +in terms of a good program then let me + + + align:start position:0% +in terms of a good program then let me +know because er's ended um so we're + + align:start position:0% +know because er's ended um so we're + + + align:start position:0% +know because er's ended um so we're +thinking of the next soap opera so I + + align:start position:0% +thinking of the next soap opera so I + + + align:start position:0% +thinking of the next soap opera so I +just want to talk about a few points + + align:start position:0% +just want to talk about a few points + + + align:start position:0% +just want to talk about a few points +this is a safe surgery checklist this is + + align:start position:0% +this is a safe surgery checklist this is + + + align:start position:0% +this is a safe surgery checklist this is +the PO point when you're identifying the + + align:start position:0% +the PO point when you're identifying the + + + align:start position:0% +the PO point when you're identifying the +pause points there have to be natural + + align:start position:0% +pause points there have to be natural + + + align:start position:0% +pause points there have to be natural +breaks in your clinical workflow so you + + align:start position:0% +breaks in your clinical workflow so you + + + align:start position:0% +breaks in your clinical workflow so you +want them I mean the safe surgery was + + align:start position:0% +want them I mean the safe surgery was + + + align:start position:0% +want them I mean the safe surgery was +perfect like when people get together + + align:start position:0% +perfect like when people get together + + + align:start position:0% +perfect like when people get together +and they're about to start a case you're + + align:start position:0% +and they're about to start a case you're + + + align:start position:0% +and they're about to start a case you're +already sort of talking and chatting + + align:start position:0% +already sort of talking and chatting + + + align:start position:0% +already sort of talking and chatting +pick up a checklist at the end when the + + align:start position:0% +pick up a checklist at the end when the + + + align:start position:0% +pick up a checklist at the end when the +patient leaves natural pause Point pick + + align:start position:0% +patient leaves natural pause Point pick + + + align:start position:0% +patient leaves natural pause Point pick +up the checklist for child birth there + + align:start position:0% +up the checklist for child birth there + + + align:start position:0% +up the checklist for child birth there +was a little bit of anxiety over where + + align:start position:0% +was a little bit of anxiety over where + + + align:start position:0% +was a little bit of anxiety over where +we were going to create these natural + + align:start position:0% +we were going to create these natural + + + align:start position:0% +we were going to create these natural +breaks and the reason it's important to + + align:start position:0% +breaks and the reason it's important to + + + align:start position:0% +breaks and the reason it's important to +be natural you don't want too much + + align:start position:0% +be natural you don't want too much + + + align:start position:0% +be natural you don't want too much +Behavior change happening so you want + + align:start position:0% +Behavior change happening so you want + + + align:start position:0% +Behavior change happening so you want +people to feel like it's completely + + align:start position:0% +people to feel like it's completely + + + align:start position:0% +people to feel like it's completely +normal to then have to pick up the + + align:start position:0% +normal to then have to pick up the + + + align:start position:0% +normal to then have to pick up the +checklist and do + + align:start position:0% +checklist and do + + + align:start position:0% +checklist and do +something um CR missions these are + + align:start position:0% +something um CR missions these are + + + align:start position:0% +something um CR missions these are +things that if you don't do you will + + align:start position:0% +things that if you don't do you will + + + align:start position:0% +things that if you don't do you will +cause severe harm and they make up your + + align:start position:0% +cause severe harm and they make up your + + + align:start position:0% +cause severe harm and they make up your +checklist items as we spoke about every + + align:start position:0% +checklist items as we spoke about every + + + align:start position:0% +checklist items as we spoke about every +single one of our checklists says this + + align:start position:0% +single one of our checklists says this + + + align:start position:0% +single one of our checklists says this +checklist is not intended to be + + align:start position:0% +checklist is not intended to be + + + align:start position:0% +checklist is not intended to be +comprehensive additions and + + align:start position:0% +comprehensive additions and + + + align:start position:0% +comprehensive additions and +modifications to fit local practice are + + align:start position:0% +modifications to fit local practice are + + + align:start position:0% +modifications to fit local practice are +encouraged that's not just about + + align:start position:0% +encouraged that's not just about + + + align:start position:0% +encouraged that's not just about +humility actually we realize that local + + align:start position:0% +humility actually we realize that local + + + align:start position:0% +humility actually we realize that local +ownership is really important so they + + align:start position:0% +ownership is really important so they + + + align:start position:0% +ownership is really important so they +don't want some tool from America being + + align:start position:0% +don't want some tool from America being + + + align:start position:0% +don't want some tool from America being +landed in Zambia and saying use this + + align:start position:0% +landed in Zambia and saying use this + + + align:start position:0% +landed in Zambia and saying use this +you'll be great because we know + + align:start position:0% +you'll be great because we know + + + align:start position:0% +you'll be great because we know +everything thing they want to be able to + + align:start position:0% +everything thing they want to be able to + + + align:start position:0% +everything thing they want to be able to +modify and say well we need to tweak + + align:start position:0% +modify and say well we need to tweak + + + align:start position:0% +modify and say well we need to tweak +this or this is + + align:start position:0% +this or this is + + + align:start position:0% +this or this is +important it has to be a Control process + + align:start position:0% +important it has to be a Control process + + + align:start position:0% +important it has to be a Control process +because what's on the checklist is + + align:start position:0% +because what's on the checklist is + + + align:start position:0% +because what's on the checklist is +evidence-based you know it's taken a + + align:start position:0% +evidence-based you know it's taken a + + + align:start position:0% +evidence-based you know it's taken a +long time to agree and so we actually + + align:start position:0% +long time to agree and so we actually + + + align:start position:0% +long time to agree and so we actually +now have a bit of a process on how you + + align:start position:0% +now have a bit of a process on how you + + + align:start position:0% +now have a bit of a process on how you +decide what comes on and off and + + align:start position:0% +decide what comes on and off and + + + align:start position:0% +decide what comes on and off and +generally you'll find people want add + + align:start position:0% +generally you'll find people want add + + + align:start position:0% +generally you'll find people want add +Lots on so we have a bit of a rule you + + align:start position:0% +Lots on so we have a bit of a rule you + + + align:start position:0% +Lots on so we have a bit of a rule you +can add one off you probably need to + + align:start position:0% +can add one off you probably need to + + + align:start position:0% +can add one off you probably need to +take one off um the other thing is does + + align:start position:0% +take one off um the other thing is does + + + align:start position:0% +take one off um the other thing is does +it actually impact mortality so for + + align:start position:0% +it actually impact mortality so for + + + align:start position:0% +it actually impact mortality so for +child birth everyone's like we want to + + align:start position:0% +child birth everyone's like we want to + + + align:start position:0% +child birth everyone's like we want to +put pomy on like so that's like a cut + + align:start position:0% +put pomy on like so that's like a cut + + + align:start position:0% +put pomy on like so that's like a cut +instead of tearing and like well is that + + align:start position:0% +instead of tearing and like well is that + + + align:start position:0% +instead of tearing and like well is that +actually going to prevent deaths no okay + + align:start position:0% +actually going to prevent deaths no okay + + + align:start position:0% +actually going to prevent deaths no okay +perhaps we won't put it on the checklist + + align:start position:0% +perhaps we won't put it on the checklist + + + align:start position:0% +perhaps we won't put it on the checklist +but it is important to get their local + + align:start position:0% +but it is important to get their local + + + align:start position:0% +but it is important to get their local +bind and for them to feel it's their + + align:start position:0% +bind and for them to feel it's their + + + align:start position:0% +bind and for them to feel it's their +tool and then we spoke a little bit + + align:start position:0% +tool and then we spoke a little bit + + + align:start position:0% +tool and then we spoke a little bit +about this it's that magical ingredient + + align:start position:0% +about this it's that magical ingredient + + + align:start position:0% +about this it's that magical ingredient +so processes like giving antibiotics are + + align:start position:0% +so processes like giving antibiotics are + + + align:start position:0% +so processes like giving antibiotics are +important in the developing world + + align:start position:0% +important in the developing world + + + align:start position:0% +important in the developing world +because they're not doing it most of + + align:start position:0% +because they're not doing it most of + + + align:start position:0% +because they're not doing it most of +these processes people are doing in the + + align:start position:0% +these processes people are doing in the + + + align:start position:0% +these processes people are doing in the +developed world and yet there was still + + align:start position:0% +developed world and yet there was still + + + align:start position:0% +developed world and yet there was still +difference and there I think it's that + + align:start position:0% +difference and there I think it's that + + + align:start position:0% +difference and there I think it's that +oh that's very kind thank you I love MIT + + align:start position:0% +oh that's very kind thank you I love MIT + + + align:start position:0% +oh that's very kind thank you I love MIT +um uh this is where I mean my sister's + + align:start position:0% +um uh this is where I mean my sister's + + + align:start position:0% +um uh this is where I mean my sister's +uh trained to be a pilot and her second + + align:start position:0% +uh trained to be a pilot and her second + + + align:start position:0% +uh trained to be a pilot and her second +lecture was she got handed this book on + + align:start position:0% +lecture was she got handed this book on + + + align:start position:0% +lecture was she got handed this book on +human + + align:start position:0% +human + + + align:start position:0% +human +factors and I picked it up it's + + align:start position:0% +factors and I picked it up it's + + + align:start position:0% +factors and I picked it up it's +something you've discussed and I was + + align:start position:0% +something you've discussed and I was + + + align:start position:0% +something you've discussed and I was +like oh this is great and she looked at + + align:start position:0% +like oh this is great and she looked at + + + align:start position:0% +like oh this is great and she looked at +me and went hang on a minute you're + + align:start position:0% +me and went hang on a minute you're + + + align:start position:0% +me and went hang on a minute you're +making life death decisions all the time + + align:start position:0% +making life death decisions all the time + + + align:start position:0% +making life death decisions all the time +have you not read this book on human + + align:start position:0% +have you not read this book on human + + + align:start position:0% +have you not read this book on human +factors and I was like uh no actually we + + align:start position:0% +factors and I was like uh no actually we + + + align:start position:0% +factors and I was like uh no actually we +were just told you go to medal School + + align:start position:0% +were just told you go to medal School + + + align:start position:0% +were just told you go to medal School +you read your books you do good training + + align:start position:0% +you read your books you do good training + + + align:start position:0% +you read your books you do good training +and you're God and everything will be + + align:start position:0% +and you're God and everything will be + + + align:start position:0% +and you're God and everything will be +fine and she was like oh right and she + + align:start position:0% +fine and she was like oh right and she + + + align:start position:0% +fine and she was like oh right and she +said what about crew Resource Management + + align:start position:0% +said what about crew Resource Management + + + align:start position:0% +said what about crew Resource Management +I was like what's that she says well + + align:start position:0% +I was like what's that she says well + + + align:start position:0% +I was like what's that she says well +when we go into the cockpit we have + + align:start position:0% +when we go into the cockpit we have + + + align:start position:0% +when we go into the cockpit we have +moments to create an effective team and + + align:start position:0% +moments to create an effective team and + + + align:start position:0% +moments to create an effective team and +the effective team is important not when + + align:start position:0% +the effective team is important not when + + + align:start position:0% +the effective team is important not when +the flight's going well it's important + + align:start position:0% +the flight's going well it's important + + + align:start position:0% +the flight's going well it's important +when there's an emergency and I had I'm + + align:start position:0% +when there's an emergency and I had I'm + + + align:start position:0% +when there's an emergency and I had I'm +an OB obstetrician and I remember doing + + align:start position:0% +an OB obstetrician and I remember doing + + + align:start position:0% +an OB obstetrician and I remember doing +this procedure where I needed blood in + + align:start position:0% +this procedure where I needed blood in + + + align:start position:0% +this procedure where I needed blood in +the middle of the case and I yell No One + + align:start position:0% +the middle of the case and I yell No One + + + align:start position:0% +the middle of the case and I yell No One +Ever Knows who the millions of people + + align:start position:0% +Ever Knows who the millions of people + + + align:start position:0% +Ever Knows who the millions of people +are in theater right so I yell off to + + align:start position:0% +are in theater right so I yell off to + + + align:start position:0% +are in theater right so I yell off to +this woman go get me blood and 20 + + align:start position:0% +this woman go get me blood and 20 + + + align:start position:0% +this woman go get me blood and 20 +minutes later I'm like where's the blood + + align:start position:0% +minutes later I'm like where's the blood + + + align:start position:0% +minutes later I'm like where's the blood +getting angry that the blood hasn't + + align:start position:0% +getting angry that the blood hasn't + + + align:start position:0% +getting angry that the blood hasn't +arrived and I look at her she's like I'm + + align:start position:0% +arrived and I look at her she's like I'm + + + align:start position:0% +arrived and I look at her she's like I'm +just an observer I don't know where the + + align:start position:0% +just an observer I don't know where the + + + align:start position:0% +just an observer I don't know where the +blood is I was like oh I really should + + align:start position:0% +blood is I was like oh I really should + + + align:start position:0% +blood is I was like oh I really should +know who was my like circulating nurse + + align:start position:0% +know who was my like circulating nurse + + + align:start position:0% +know who was my like circulating nurse +and that's the M magical ingredient + + align:start position:0% +and that's the M magical ingredient + + + align:start position:0% +and that's the M magical ingredient +behind this they sort of confirm who you + + align:start position:0% +behind this they sort of confirm who you + + + align:start position:0% +behind this they sort of confirm who you +are let's all sit together the other + + align:start position:0% +are let's all sit together the other + + + align:start position:0% +are let's all sit together the other +component when with the checklist was + + align:start position:0% +component when with the checklist was + + + align:start position:0% +component when with the checklist was +the briefing like you all got together + + align:start position:0% +the briefing like you all got together + + + align:start position:0% +the briefing like you all got together +and discussed the cases of the day so I + + align:start position:0% +and discussed the cases of the day so I + + + align:start position:0% +and discussed the cases of the day so I +come from the UK it was mandated across + + align:start position:0% +come from the UK it was mandated across + + + align:start position:0% +come from the UK it was mandated across +hospitals someone was talking about + + align:start position:0% +hospitals someone was talking about + + + align:start position:0% +hospitals someone was talking about +institutional support but everyone had + + align:start position:0% +institutional support but everyone had + + + align:start position:0% +institutional support but everyone had +to do it and people were like oh God + + align:start position:0% +to do it and people were like oh God + + + align:start position:0% +to do it and people were like oh God +this is going to be such a nightmare but + + align:start position:0% +this is going to be such a nightmare but + + + align:start position:0% +this is going to be such a nightmare but +the briefing really helped so we one of + + align:start position:0% +the briefing really helped so we one of + + + align:start position:0% +the briefing really helped so we one of +the incentives we used is we timed our + + align:start position:0% +the incentives we used is we timed our + + + align:start position:0% +the incentives we used is we timed our +day so if I had six operations normally + + align:start position:0% +day so if I had six operations normally + + + align:start position:0% +day so if I had six operations normally +that would start at 9:00 with faf in + + align:start position:0% +that would start at 9:00 with faf in + + + align:start position:0% +that would start at 9:00 with faf in +between and finish at 6:30 an hour and a + + align:start position:0% +between and finish at 6:30 an hour and a + + + align:start position:0% +between and finish at 6:30 an hour and a +half after everyone should have left we + + align:start position:0% +half after everyone should have left we + + + align:start position:0% +half after everyone should have left we +started timing the day and recording it + + align:start position:0% +started timing the day and recording it + + + align:start position:0% +started timing the day and recording it +and we we were reducing the time because + + align:start position:0% +and we we were reducing the time because + + + align:start position:0% +and we we were reducing the time because +there was less sort of you know messing + + align:start position:0% +there was less sort of you know messing + + + align:start position:0% +there was less sort of you know messing +around between cases so the nurses were + + align:start position:0% +around between cases so the nurses were + + + align:start position:0% +around between cases so the nurses were +able to leave an hour earlier so there + + align:start position:0% +able to leave an hour earlier so there + + + align:start position:0% +able to leave an hour earlier so there +there's a lot to be said for that + + align:start position:0% +there's a lot to be said for that + + + align:start position:0% +there's a lot to be said for that +teamwork communication component that we + + align:start position:0% +teamwork communication component that we + + + align:start position:0% +teamwork communication component that we +can't really + + align:start position:0% +can't really + + + align:start position:0% +can't really +measure so as I said our challenge was + + align:start position:0% +measure so as I said our challenge was + + + align:start position:0% +measure so as I said our challenge was +mdgs four and five we know that we're + + align:start position:0% +mdgs four and five we know that we're + + + align:start position:0% +mdgs four and five we know that we're +having all this mortality and we know + + align:start position:0% +having all this mortality and we know + + + align:start position:0% +having all this mortality and we know +the causes and what's really sad is that + + align:start position:0% +the causes and what's really sad is that + + + align:start position:0% +the causes and what's really sad is that +we have proven interventions that are + + align:start position:0% +we have proven interventions that are + + + align:start position:0% +we have proven interventions that are +inexpensive and who has been trying to + + align:start position:0% +inexpensive and who has been trying to + + + align:start position:0% +inexpensive and who has been trying to +deliver these effectively four decades + + align:start position:0% +deliver these effectively four decades + + + align:start position:0% +deliver these effectively four decades +and we've been totally unable to get + + align:start position:0% +and we've been totally unable to get + + + align:start position:0% +and we've been totally unable to get +them to the bedside + + align:start position:0% +them to the bedside + + + align:start position:0% +them to the bedside +reliably it's a slightly different + + align:start position:0% +reliably it's a slightly different + + + align:start position:0% +reliably it's a slightly different +challenge to the safe surgery checklist + + align:start position:0% +challenge to the safe surgery checklist + + + align:start position:0% +challenge to the safe surgery checklist +so 99% of our burden of disease is in + + align:start position:0% +so 99% of our burden of disease is in + + + align:start position:0% +so 99% of our burden of disease is in +the developing world and why that's + + align:start position:0% +the developing world and why that's + + + align:start position:0% +the developing world and why that's +important is it's got to be very + + align:start position:0% +important is it's got to be very + + + align:start position:0% +important is it's got to be very +succinct these uh caregivers don't have + + align:start position:0% +succinct these uh caregivers don't have + + + align:start position:0% +succinct these uh caregivers don't have +excess time and second we can't have + + align:start position:0% +excess time and second we can't have + + + align:start position:0% +excess time and second we can't have +like intense Supply requirements because + + align:start position:0% +like intense Supply requirements because + + + align:start position:0% +like intense Supply requirements because +they probably won't have the resources + + align:start position:0% +they probably won't have the resources + + + align:start position:0% +they probably won't have the resources +there consistently available again we + + align:start position:0% +there consistently available again we + + + align:start position:0% +there consistently available again we +don't have surge that have had some kind + + align:start position:0% +don't have surge that have had some kind + + + align:start position:0% +don't have surge that have had some kind +of training some of the caregivers in + + align:start position:0% +of training some of the caregivers in + + + align:start position:0% +of training some of the caregivers in +these places have just been taught how + + align:start position:0% +these places have just been taught how + + + align:start position:0% +these places have just been taught how +to do some deliveries in the last six + + align:start position:0% +to do some deliveries in the last six + + + align:start position:0% +to do some deliveries in the last six +months or minimal training so again it + + align:start position:0% +months or minimal training so again it + + + align:start position:0% +months or minimal training so again it +had to be a slightly different tool the + + align:start position:0% +had to be a slightly different tool the + + + align:start position:0% +had to be a slightly different tool the +high risk period that you want to cover + + align:start position:0% +high risk period that you want to cover + + + align:start position:0% +high risk period that you want to cover +with the checklist well ours could cover + + align:start position:0% +with the checklist well ours could cover + + + align:start position:0% +with the checklist well ours could cover +weeks you know days to weeks someone + + align:start position:0% +weeks you know days to weeks someone + + + align:start position:0% +weeks you know days to weeks someone +comes in on a Monday by the time they've + + align:start position:0% +comes in on a Monday by the time they've + + + align:start position:0% +comes in on a Monday by the time they've +delivered and they're being discharged + + align:start position:0% +delivered and they're being discharged + + + align:start position:0% +delivered and they're being discharged +it could be sort of 5 days later it + + align:start position:0% +it could be sort of 5 days later it + + + align:start position:0% +it could be sort of 5 days later it +covers many rooms it covers multiple + + align:start position:0% +covers many rooms it covers multiple + + + align:start position:0% +covers many rooms it covers multiple +caregivers and it could be across + + align:start position:0% +caregivers and it could be across + + + align:start position:0% +caregivers and it could be across +facilities like someone gets referred so + + align:start position:0% +facilities like someone gets referred so + + + align:start position:0% +facilities like someone gets referred so +how is this checklist going to cover all + + align:start position:0% +how is this checklist going to cover all + + + align:start position:0% +how is this checklist going to cover all +these situations and we don't have an + + align:start position:0% +these situations and we don't have an + + + align:start position:0% +these situations and we don't have an +obvious team structure to work with in + + align:start position:0% +obvious team structure to work with in + + + align:start position:0% +obvious team structure to work with in +some situations you'll just have the one + + align:start position:0% +some situations you'll just have the one + + + align:start position:0% +some situations you'll just have the one +Midwife in the little health facility so + + align:start position:0% +Midwife in the little health facility so + + + align:start position:0% +Midwife in the little health facility so +put those in Reds because they were + + align:start position:0% +put those in Reds because they were + + + align:start position:0% +put those in Reds because they were +challenges some people felt the next one + + align:start position:0% +challenges some people felt the next one + + + align:start position:0% +challenges some people felt the next one +should be a challenge the woman's well + + align:start position:0% +should be a challenge the woman's well + + + align:start position:0% +should be a challenge the woman's well +you know pregnancy isn't a disease and + + align:start position:0% +you know pregnancy isn't a disease and + + + align:start position:0% +you know pregnancy isn't a disease and +she's awake what does that mean do we + + align:start position:0% +she's awake what does that mean do we + + + align:start position:0% +she's awake what does that mean do we +just bypass her or do we include her in + + align:start position:0% +just bypass her or do we include her in + + + align:start position:0% +just bypass her or do we include her in +the team I've put it in Orange because I + + align:start position:0% +the team I've put it in Orange because I + + + align:start position:0% +the team I've put it in Orange because I +actually think it's a benefit and then + + align:start position:0% +actually think it's a benefit and then + + + align:start position:0% +actually think it's a benefit and then +the advantage we had is that we've + + align:start position:0% +the advantage we had is that we've + + + align:start position:0% +the advantage we had is that we've +actually got a good evidence base for + + align:start position:0% +actually got a good evidence base for + + + align:start position:0% +actually got a good evidence base for +Safe child birth compared to safe + + align:start position:0% +Safe child birth compared to safe + + + align:start position:0% +Safe child birth compared to safe +surgery don't worry about the detail the + + align:start position:0% +surgery don't worry about the detail the + + + align:start position:0% +surgery don't worry about the detail the +reason I brought the slide up is we used + + align:start position:0% +reason I brought the slide up is we used + + + align:start position:0% +reason I brought the slide up is we used +every single source of information we + + align:start position:0% +every single source of information we + + + align:start position:0% +every single source of information we +could find published unpublished + + align:start position:0% +could find published unpublished + + + align:start position:0% +could find published unpublished +literature opinion getting experts + + align:start position:0% +literature opinion getting experts + + + align:start position:0% +literature opinion getting experts +together and it was all to ensure that + + align:start position:0% +together and it was all to ensure that + + + align:start position:0% +together and it was all to ensure that +there wasn't something that we hadn't + + align:start position:0% +there wasn't something that we hadn't + + + align:start position:0% +there wasn't something that we hadn't +covered that would come up later on in + + align:start position:0% +covered that would come up later on in + + + align:start position:0% +covered that would come up later on in +the progam uh process of forming this + + align:start position:0% +the progam uh process of forming this + + + align:start position:0% +the progam uh process of forming this +checklist so how do you decide on your + + align:start position:0% +checklist so how do you decide on your + + + align:start position:0% +checklist so how do you decide on your +highrisk period Well we were sort of + + align:start position:0% +highrisk period Well we were sort of + + + align:start position:0% +highrisk period Well we were sort of +given that it's the 24-hour highrisk + + align:start position:0% +given that it's the 24-hour highrisk + + + align:start position:0% +given that it's the 24-hour highrisk +period where you know from admission to + + align:start position:0% +period where you know from admission to + + + align:start position:0% +period where you know from admission to +discharge + + align:start position:0% +discharge + + + align:start position:0% +discharge +um but how do you decide on your pause + + align:start position:0% +um but how do you decide on your pause + + + align:start position:0% +um but how do you decide on your pause +points as I said pause point one and + + align:start position:0% +points as I said pause point one and + + + align:start position:0% +points as I said pause point one and +four were quite easy and then yeah go + + align:start position:0% +four were quite easy and then yeah go + + + align:start position:0% +four were quite easy and then yeah go +ahead where are The Debs ah so the + + align:start position:0% +ahead where are The Debs ah so the + + + align:start position:0% +ahead where are The Debs ah so the +highest number of deaths are actually + + align:start position:0% +highest number of deaths are actually + + + align:start position:0% +highest number of deaths are actually +from uh at delivery so labor to delivery + + align:start position:0% +from uh at delivery so labor to delivery + + + align:start position:0% +from uh at delivery so labor to delivery +and then um postpartum so the first 48 + + align:start position:0% +and then um postpartum so the first 48 + + + align:start position:0% +and then um postpartum so the first 48 +Hours um so that's why we said right + + align:start position:0% +Hours um so that's why we said right + + + align:start position:0% +Hours um so that's why we said right +we'll cover admission to discharge it + + align:start position:0% +we'll cover admission to discharge it + + + align:start position:0% +we'll cover admission to discharge it +doesn't cover the 48 hour so we cover + + align:start position:0% +doesn't cover the 48 hour so we cover + + + align:start position:0% +doesn't cover the 48 hour so we cover +all the way from dischar uh any + + align:start position:0% +all the way from dischar uh any + + + align:start position:0% +all the way from dischar uh any +discharge from facilities so so actually + + align:start position:0% +discharge from facilities so so actually + + + align:start position:0% +discharge from facilities so so actually +the tool covers if someone's discharged + + align:start position:0% +the tool covers if someone's discharged + + + align:start position:0% +the tool covers if someone's discharged +within 6 hours it'll only cover that if + + align:start position:0% +within 6 hours it'll only cover that if + + + align:start position:0% +within 6 hours it'll only cover that if +someone's discharged within a week we + + align:start position:0% +someone's discharged within a week we + + + align:start position:0% +someone's discharged within a week we +cover the whole + + align:start position:0% +cover the whole + + + align:start position:0% +cover the whole +week um and the two middle pause points + + align:start position:0% +week um and the two middle pause points + + + align:start position:0% +week um and the two middle pause points +were the sort of fudge Factor now + + align:start position:0% +were the sort of fudge Factor now + + + align:start position:0% +were the sort of fudge Factor now +ideally you'd have a pause point one + + align:start position:0% +ideally you'd have a pause point one + + + align:start position:0% +ideally you'd have a pause point one +minute after delivery because that's + + align:start position:0% +minute after delivery because that's + + + align:start position:0% +minute after delivery because that's +where you want the oxytocin to be given + + align:start position:0% +where you want the oxytocin to be given + + + align:start position:0% +where you want the oxytocin to be given +to prevent Hemorrhage but one minute + + align:start position:0% +to prevent Hemorrhage but one minute + + + align:start position:0% +to prevent Hemorrhage but one minute +someone's got gloves on and they're in + + align:start position:0% +someone's got gloves on and they're in + + + align:start position:0% +someone's got gloves on and they're in +the midst of stuff they're not going to + + align:start position:0% +the midst of stuff they're not going to + + + align:start position:0% +the midst of stuff they're not going to +pick up a + + align:start position:0% +pick up a + + + align:start position:0% +pick up a +checklist and the other time you'd want + + align:start position:0% +checklist and the other time you'd want + + + align:start position:0% +checklist and the other time you'd want +a checklist is actually every time me do + + align:start position:0% +a checklist is actually every time me do + + + align:start position:0% +a checklist is actually every time me do +an examination during labor but then our + + align:start position:0% +an examination during labor but then our + + + align:start position:0% +an examination during labor but then our +checklist would be really long and so + + align:start position:0% +checklist would be really long and so + + + align:start position:0% +checklist would be really long and so +again the checklist would SN so there is + + align:start position:0% +again the checklist would SN so there is + + + align:start position:0% +again the checklist would SN so there is +a compromise and what's actually going + + align:start position:0% +a compromise and what's actually going + + + align:start position:0% +a compromise and what's actually going +to be effectively + + align:start position:0% +to be effectively + + + align:start position:0% +to be effectively +implemented again it's not about the + + align:start position:0% +implemented again it's not about the + + + align:start position:0% +implemented again it's not about the +details people say I'm going to fall I'm + + align:start position:0% +details people say I'm going to fall I'm + + + align:start position:0% +details people say I'm going to fall I'm +going to make a checklist and then I'm + + align:start position:0% +going to make a checklist and then I'm + + + align:start position:0% +going to make a checklist and then I'm +going to tral it next week this took two + + align:start position:0% +going to tral it next week this took two + + + align:start position:0% +going to tral it next week this took two +years and yes a lot of this is because + + align:start position:0% +years and yes a lot of this is because + + + align:start position:0% +years and yes a lot of this is because +we were working with who we wanted to + + align:start position:0% +we were working with who we wanted to + + + align:start position:0% +we were working with who we wanted to +get the acceptability worldwide + + align:start position:0% +get the acceptability worldwide + + + align:start position:0% +get the acceptability worldwide +acceptability of everyone and all that + + align:start position:0% +acceptability of everyone and all that + + + align:start position:0% +acceptability of everyone and all that +takes a long time and I'm not saying it + + align:start position:0% +takes a long time and I'm not saying it + + + align:start position:0% +takes a long time and I'm not saying it +has to to take two years to make a + + align:start position:0% +has to to take two years to make a + + + align:start position:0% +has to to take two years to make a +checklist I'm just saying that if you + + align:start position:0% +checklist I'm just saying that if you + + + align:start position:0% +checklist I'm just saying that if you +want that acceptability across the board + + align:start position:0% +want that acceptability across the board + + + align:start position:0% +want that acceptability across the board +and you are thinking of worldwide Global + + align:start position:0% +and you are thinking of worldwide Global + + + align:start position:0% +and you are thinking of worldwide Global +scaleup then it's a long + + align:start position:0% +scaleup then it's a long + + + align:start position:0% +scaleup then it's a long +process and this is the who's who of + + align:start position:0% +process and this is the who's who of + + + align:start position:0% +process and this is the who's who of +Safe child birth and everyone we spoke + + align:start position:0% +Safe child birth and everyone we spoke + + + align:start position:0% +Safe child birth and everyone we spoke +to their network was wide all the red + + align:start position:0% +to their network was wide all the red + + + align:start position:0% +to their network was wide all the red +dots they either have research going on + + align:start position:0% +dots they either have research going on + + + align:start position:0% +dots they either have research going on +there they've worked there they have + + align:start position:0% +there they've worked there they have + + + align:start position:0% +there they've worked there they have +contacts there and we the green dots + + align:start position:0% +contacts there and we the green dots + + + align:start position:0% +contacts there and we the green dots +represent where we did usability + + align:start position:0% +represent where we did usability + + + align:start position:0% +represent where we did usability +feedback so it wasn't testing we said to + + align:start position:0% +feedback so it wasn't testing we said to + + + align:start position:0% +feedback so it wasn't testing we said to +these people please take this tool try + + align:start position:0% +these people please take this tool try + + + align:start position:0% +these people please take this tool try +it on one or two deliveries so ihi is + + align:start position:0% +it on one or two deliveries so ihi is + + + align:start position:0% +it on one or two deliveries so ihi is +all about starting small we did that in + + align:start position:0% +all about starting small we did that in + + + align:start position:0% +all about starting small we did that in +the sort of crafting method we said okay + + align:start position:0% +the sort of crafting method we said okay + + + align:start position:0% +the sort of crafting method we said okay +you take this and then we'll have a call + + align:start position:0% +you take this and then we'll have a call + + + align:start position:0% +you take this and then we'll have a call +with you and you change and the + + align:start position:0% +with you and you change and the + + + align:start position:0% +with you and you change and the +checklist however you want and so at the + + align:start position:0% +checklist however you want and so at the + + + align:start position:0% +checklist however you want and so at the +end we had sort of 11 checklists and + + align:start position:0% +end we had sort of 11 checklists and + + + align:start position:0% +end we had sort of 11 checklists and +then we were going to combine + + align:start position:0% +then we were going to combine + + + align:start position:0% +then we were going to combine +them and this is what happened there's + + align:start position:0% +them and this is what happened there's + + + align:start position:0% +them and this is what happened there's +it's a two-sided checklist what it's + + align:start position:0% +it's a two-sided checklist what it's + + + align:start position:0% +it's a two-sided checklist what it's +four pause points the first is the two + + align:start position:0% +four pause points the first is the two + + + align:start position:0% +four pause points the first is the two +one before delivery and at the end on + + align:start position:0% +one before delivery and at the end on + + + align:start position:0% +one before delivery and at the end on +the other side is the two puse points + + align:start position:0% +the other side is the two puse points + + + align:start position:0% +the other side is the two puse points +after + + align:start position:0% +after + + + align:start position:0% +after +delivery and what I just wanted to show + + align:start position:0% +delivery and what I just wanted to show + + + align:start position:0% +delivery and what I just wanted to show +you on this is this is revision 67 and + + align:start position:0% +you on this is this is revision 67 and + + + align:start position:0% +you on this is this is revision 67 and +I'm sure by the time it gets onto who + + align:start position:0% +I'm sure by the time it gets onto who + + + align:start position:0% +I'm sure by the time it gets onto who +website it'll be 88 or + + align:start position:0% +website it'll be 88 or + + + align:start position:0% +website it'll be 88 or +something and what I wanted to show you + + align:start position:0% +something and what I wanted to show you + + + align:start position:0% +something and what I wanted to show you +on this is two differences between um + + align:start position:0% +on this is two differences between um + + + align:start position:0% +on this is two differences between um +this one and the safe surgery because of + + align:start position:0% +this one and the safe surgery because of + + + align:start position:0% +this one and the safe surgery because of +what we're dealing with so I told you + + align:start position:0% +what we're dealing with so I told you + + + align:start position:0% +what we're dealing with so I told you +about the variability of the caregiver + + align:start position:0% +about the variability of the caregiver + + + align:start position:0% +about the variability of the caregiver +you can say does a mother need to start + + align:start position:0% +you can say does a mother need to start + + + align:start position:0% +you can say does a mother need to start +antibiotics + + align:start position:0% +antibiotics + + + align:start position:0% +antibiotics +I don't know cuz you don't you can't + + align:start position:0% +I don't know cuz you don't you can't + + + align:start position:0% +I don't know cuz you don't you can't +rely on their training so in America + + align:start position:0% +rely on their training so in America + + + align:start position:0% +rely on their training so in America +we'd hope to get rid of the second + + align:start position:0% +we'd hope to get rid of the second + + + align:start position:0% +we'd hope to get rid of the second +column because they don't need to be + + align:start position:0% +column because they don't need to be + + + align:start position:0% +column because they don't need to be +told when to do things but for these + + align:start position:0% +told when to do things but for these + + + align:start position:0% +told when to do things but for these +settings it was crucial that we gave + + align:start position:0% +settings it was crucial that we gave + + + align:start position:0% +settings it was crucial that we gave +them the criteria and we were really + + align:start position:0% +them the criteria and we were really + + + align:start position:0% +them the criteria and we were really +anxious like oh the font's small Boeing + + align:start position:0% +anxious like oh the font's small Boeing + + + align:start position:0% +anxious like oh the font's small Boeing +didn't like it you know there's way too + + align:start position:0% +didn't like it you know there's way too + + + align:start position:0% +didn't like it you know there's way too +much stuff on the checklist the feedback + + align:start position:0% +much stuff on the checklist the feedback + + + align:start position:0% +much stuff on the checklist the feedback +we got was that was critical and + + align:start position:0% +we got was that was critical and + + + align:start position:0% +we got was that was critical and +actually in the modification stage that + + align:start position:0% +actually in the modification stage that + + + align:start position:0% +actually in the modification stage that +ended up being a fabulous training tool + + align:start position:0% +ended up being a fabulous training tool + + + align:start position:0% +ended up being a fabulous training tool +because when they discussed the criteria + + align:start position:0% +because when they discussed the criteria + + + align:start position:0% +because when they discussed the criteria +for things + + align:start position:0% +for things + + + align:start position:0% +for things +like oh I didn't know that and why did + + align:start position:0% +like oh I didn't know that and why did + + + align:start position:0% +like oh I didn't know that and why did +we do this and actually The Midwives + + align:start position:0% +we do this and actually The Midwives + + + align:start position:0% +we do this and actually The Midwives +were learning as they were discussing + + align:start position:0% +were learning as they were discussing + + + align:start position:0% +were learning as they were discussing +the checklist the second component in + + align:start position:0% +the checklist the second component in + + + align:start position:0% +the checklist the second component in +oval is that's how we decided to include + + align:start position:0% +oval is that's how we decided to include + + + align:start position:0% +oval is that's how we decided to include +the mother and her birth companion we + + align:start position:0% +the mother and her birth companion we + + + align:start position:0% +the mother and her birth companion we +actually said right you're member of + + align:start position:0% +actually said right you're member of + + + align:start position:0% +actually said right you're member of +this team we're going to tell you these + + align:start position:0% +this team we're going to tell you these + + + align:start position:0% +this team we're going to tell you these +are the danger signs that you should be + + align:start position:0% +are the danger signs that you should be + + + align:start position:0% +are the danger signs that you should be +calling the healthcare worker for it's + + align:start position:0% +calling the healthcare worker for it's + + + align:start position:0% +calling the healthcare worker for it's +not like in England where you have one + + align:start position:0% +not like in England where you have one + + + align:start position:0% +not like in England where you have one +Midwife you know to one patient you have + + align:start position:0% +Midwife you know to one patient you have + + + align:start position:0% +Midwife you know to one patient you have +one Midwife to sometimes 25 patients + + align:start position:0% +one Midwife to sometimes 25 patients + + + align:start position:0% +one Midwife to sometimes 25 patients +delivering well let them be part of the + + align:start position:0% +delivering well let them be part of the + + + align:start position:0% +delivering well let them be part of the +process why don't you call us when you + + align:start position:0% +process why don't you call us when you + + + align:start position:0% +process why don't you call us when you +need us and that was + + align:start position:0% +need us and that was + + + align:start position:0% +need us and that was +informed so I'm going to take you to + + align:start position:0% +informed so I'm going to take you to + + + align:start position:0% +informed so I'm going to take you to +four hours from Goa lovely weather um a + + align:start position:0% +four hours from Goa lovely weather um a + + + align:start position:0% +four hours from Goa lovely weather um a +rural Health Center called Goot it's the + + align:start position:0% +rural Health Center called Goot it's the + + + align:start position:0% +rural Health Center called Goot it's the +levels in India sort of Primary Health + + align:start position:0% +levels in India sort of Primary Health + + + align:start position:0% +levels in India sort of Primary Health +Center then a community health center + + align:start position:0% +Center then a community health center + + + align:start position:0% +Center then a community health center +than a district hospital and this was + + align:start position:0% +than a district hospital and this was + + + align:start position:0% +than a district hospital and this was +like an upgraded Community Health Center + + align:start position:0% +like an upgraded Community Health Center + + + align:start position:0% +like an upgraded Community Health Center +about 4,000 deliveries a year one or two + + align:start position:0% +about 4,000 deliveries a year one or two + + + align:start position:0% +about 4,000 deliveries a year one or two +obss depending on whether they felt like + + align:start position:0% +obss depending on whether they felt like + + + align:start position:0% +obss depending on whether they felt like +coming in and majority of the nurses + + align:start position:0% +coming in and majority of the nurses + + + align:start position:0% +coming in and majority of the nurses +doing the deliveries but they rotate + + align:start position:0% +doing the deliveries but they rotate + + + align:start position:0% +doing the deliveries but they rotate +around the hospital so they're not just + + align:start position:0% +around the hospital so they're not just + + + align:start position:0% +around the hospital so they're not just +OB Patric nurses they've never had + + align:start position:0% +OB Patric nurses they've never had + + + align:start position:0% +OB Patric nurses they've never had +quality improvement they've never been + + align:start position:0% +quality improvement they've never been + + + align:start position:0% +quality improvement they've never been +touched by research they just keep + + align:start position:0% +touched by research they just keep + + + align:start position:0% +touched by research they just keep +trying to do the work that they can and + + align:start position:0% +trying to do the work that they can and + + + align:start position:0% +trying to do the work that they can and +this is the classic scene corridors full + + align:start position:0% +this is the classic scene corridors full + + + align:start position:0% +this is the classic scene corridors full +of people the doctor in there has got to + + align:start position:0% +of people the doctor in there has got to + + + align:start position:0% +of people the doctor in there has got to +see these people in the next hour um + + align:start position:0% +see these people in the next hour um + + + align:start position:0% +see these people in the next hour um +because he's got three-hour clinic and + + align:start position:0% +because he's got three-hour clinic and + + + align:start position:0% +because he's got three-hour clinic and +there this is about a third of the + + align:start position:0% +there this is about a third of the + + + align:start position:0% +there this is about a third of the +patients they have a supplies board + + align:start position:0% +patients they have a supplies board + + + align:start position:0% +patients they have a supplies board +which they update in the mornings and + + align:start position:0% +which they update in the mornings and + + + align:start position:0% +which they update in the mornings and +unsurprisingly the two things that are + + align:start position:0% +unsurprisingly the two things that are + + + align:start position:0% +unsurprisingly the two things that are +really important to prevent bleeding + + align:start position:0% +really important to prevent bleeding + + + align:start position:0% +really important to prevent bleeding +after Labor they don't have + + align:start position:0% +after Labor they don't have + + + align:start position:0% +after Labor they don't have +the preeclampsia patient highrisk + + align:start position:0% +the preeclampsia patient highrisk + + + align:start position:0% +the preeclampsia patient highrisk +patient here would be in high dependency + + align:start position:0% +patient here would be in high dependency + + + align:start position:0% +patient here would be in high dependency +unit with lots of monitors she's in the + + align:start position:0% +unit with lots of monitors she's in the + + + align:start position:0% +unit with lots of monitors she's in the +corridor and they actually do have a + + align:start position:0% +corridor and they actually do have a + + + align:start position:0% +corridor and they actually do have a +fetal monitor it just hasn't worked for + + align:start position:0% +fetal monitor it just hasn't worked for + + + align:start position:0% +fetal monitor it just hasn't worked for +3 years it's being used as a shelf and + + align:start position:0% +3 years it's being used as a shelf and + + + align:start position:0% +3 years it's being used as a shelf and +I'm slightly anxious about that + + align:start position:0% +I'm slightly anxious about that + + + align:start position:0% +I'm slightly anxious about that +uncovered needle because it's probably + + align:start position:0% +uncovered needle because it's probably + + + align:start position:0% +uncovered needle because it's probably +being + + align:start position:0% +being + + + align:start position:0% +being +reused what were the objectives so the + + align:start position:0% +reused what were the objectives so the + + + align:start position:0% +reused what were the objectives so the +objectives were actually looking at + + align:start position:0% +objectives were actually looking at + + + align:start position:0% +objectives were actually looking at +processes we know that these + + align:start position:0% +processes we know that these + + + align:start position:0% +processes we know that these +interventions will reduce mortality who + + align:start position:0% +interventions will reduce mortality who + + + align:start position:0% +interventions will reduce mortality who +has done all that research can we get + + align:start position:0% +has done all that research can we get + + + align:start position:0% +has done all that research can we get +the healthcare providers to + + align:start position:0% +the healthcare providers to + + + align:start position:0% +the healthcare providers to +reliably deliver these interventions to + + align:start position:0% +reliably deliver these interventions to + + + align:start position:0% +reliably deliver these interventions to +every single woman that comes + + align:start position:0% +every single woman that comes + + + align:start position:0% +every single woman that comes +through and so it was a really simple + + align:start position:0% +through and so it was a really simple + + + align:start position:0% +through and so it was a really simple +pre-post um we wanted the intervention + + align:start position:0% +pre-post um we wanted the intervention + + + align:start position:0% +pre-post um we wanted the intervention +thing to be really skinny so it was a + + align:start position:0% +thing to be really skinny so it was a + + + align:start position:0% +thing to be really skinny so it was a +one-day launch because ideally what I'd + + align:start position:0% +one-day launch because ideally what I'd + + + align:start position:0% +one-day launch because ideally what I'd +like to see is someone can download the + + align:start position:0% +like to see is someone can download the + + + align:start position:0% +like to see is someone can download the +checklist you know have a bit of a video + + align:start position:0% +checklist you know have a bit of a video + + + align:start position:0% +checklist you know have a bit of a video +have a manual and run with it so it was + + align:start position:0% +have a manual and run with it so it was + + + align:start position:0% +have a manual and run with it so it was +one day launch and then four days sort + + align:start position:0% +one day launch and then four days sort + + + align:start position:0% +one day launch and then four days sort +of supportive we weren't there for the + + align:start position:0% +of supportive we weren't there for the + + + align:start position:0% +of supportive we weren't there for the +four days we got the um one of our + + align:start position:0% +four days we got the um one of our + + + align:start position:0% +four days we got the um one of our +implementing people to sort of support + + align:start position:0% +implementing people to sort of support + + + align:start position:0% +implementing people to sort of support +them + + align:start position:0% +them + + + align:start position:0% +them +and the implementing person was anst + + align:start position:0% +and the implementing person was anst + + + align:start position:0% +and the implementing person was anst +full-time anst she's been there for 20 + + align:start position:0% +full-time anst she's been there for 20 + + + align:start position:0% +full-time anst she's been there for 20 +years so she's credible um people like + + align:start position:0% +years so she's credible um people like + + + align:start position:0% +years so she's credible um people like +her but also respect her she did this on + + align:start position:0% +her but also respect her she did this on + + + align:start position:0% +her but also respect her she did this on +top of her usual workload so we weren't + + align:start position:0% +top of her usual workload so we weren't + + + align:start position:0% +top of her usual workload so we weren't +sort of drafting more Workforce in and + + align:start position:0% +sort of drafting more Workforce in and + + + align:start position:0% +sort of drafting more Workforce in and +she led the launch day we trained her + + align:start position:0% +she led the launch day we trained her + + + align:start position:0% +she led the launch day we trained her +for a day and she led it she explained + + align:start position:0% +for a day and she led it she explained + + + align:start position:0% +for a day and she led it she explained +the why so she got the nurses to share + + align:start position:0% +the why so she got the nurses to share + + + align:start position:0% +the why so she got the nurses to share +stories of you know what's happening the + + align:start position:0% +stories of you know what's happening the + + + align:start position:0% +stories of you know what's happening the +adverse outcomes near misses she then + + align:start position:0% +adverse outcomes near misses she then + + + align:start position:0% +adverse outcomes near misses she then +shared some basic Baseline data so we + + align:start position:0% +shared some basic Baseline data so we + + + align:start position:0% +shared some basic Baseline data so we +could have just shared all our Baseline + + align:start position:0% +could have just shared all our Baseline + + + align:start position:0% +could have just shared all our Baseline +data we' collected it for 3 months but + + align:start position:0% +data we' collected it for 3 months but + + + align:start position:0% +data we' collected it for 3 months but +we said well that's not feasible you + + align:start position:0% +we said well that's not feasible you + + + align:start position:0% +we said well that's not feasible you +know they're not going to be able to + + align:start position:0% +know they're not going to be able to + + + align:start position:0% +know they're not going to be able to +collect that data in these kind of + + align:start position:0% +collect that data in these kind of + + + align:start position:0% +collect that data in these kind of +settings so she just shared a few items + + align:start position:0% +settings so she just shared a few items + + + align:start position:0% +settings so she just shared a few items +and then did the modification process so + + align:start position:0% +and then did the modification process so + + + align:start position:0% +and then did the modification process so +sat down with them and said what do you + + align:start position:0% +sat down with them and said what do you + + + align:start position:0% +sat down with them and said what do you +think let's go through the items it was + + align:start position:0% +think let's go through the items it was + + + align:start position:0% +think let's go through the items it was +a bit of a training session and then the + + align:start position:0% +a bit of a training session and then the + + + align:start position:0% +a bit of a training session and then the +video for the safe surgery they' made + + align:start position:0% +video for the safe surgery they' made + + + align:start position:0% +video for the safe surgery they' made +the video at Brigham and they + + align:start position:0% +the video at Brigham and they + + + align:start position:0% +the video at Brigham and they +transported it and what we decided was + + align:start position:0% +transported it and what we decided was + + + align:start position:0% +transported it and what we decided was +that we would make it on site and it's + + align:start position:0% +that we would make it on site and it's + + + align:start position:0% +that we would make it on site and it's +sort of based on the Chinese proverb you + + align:start position:0% +sort of based on the Chinese proverb you + + + align:start position:0% +sort of based on the Chinese proverb you +know tell tell me and I'll forget show + + align:start position:0% +know tell tell me and I'll forget show + + + align:start position:0% +know tell tell me and I'll forget show +me and I'll remember involve me and I'll + + align:start position:0% +me and I'll remember involve me and I'll + + + align:start position:0% +me and I'll remember involve me and I'll +understand and you could see the bulbs + + align:start position:0% +understand and you could see the bulbs + + + align:start position:0% +understand and you could see the bulbs +going on so the chief medical officer + + align:start position:0% +going on so the chief medical officer + + + align:start position:0% +going on so the chief medical officer +who was supposed to be our local + + align:start position:0% +who was supposed to be our local + + + align:start position:0% +who was supposed to be our local +institutional leader he sort of we're + + align:start position:0% +institutional leader he sort of we're + + + align:start position:0% +institutional leader he sort of we're +making the video with him and he's like + + align:start position:0% +making the video with him and he's like + + + align:start position:0% +making the video with him and he's like +so what do I have to do I was like you + + align:start position:0% +so what do I have to do I was like you + + + align:start position:0% +so what do I have to do I was like you +have to ask the question you know is + + align:start position:0% +have to ask the question you know is + + + align:start position:0% +have to ask the question you know is +oxytocin ready and he's said is oxytocin + + align:start position:0% +oxytocin ready and he's said is oxytocin + + + align:start position:0% +oxytocin ready and he's said is oxytocin +ready can I start the operation no you + + align:start position:0% +ready can I start the operation no you + + + align:start position:0% +ready can I start the operation no you +need to wait for the response and you + + align:start position:0% +need to wait for the response and you + + + align:start position:0% +need to wait for the response and you +could see the sort of light was going on + + align:start position:0% +could see the sort of light was going on + + + align:start position:0% +could see the sort of light was going on +as we were making this video and at the + + align:start position:0% +as we were making this video and at the + + + align:start position:0% +as we were making this video and at the +end he was like wow this is great and + + align:start position:0% +end he was like wow this is great and + + + align:start position:0% +end he was like wow this is great and +then we drafted two two very sort of + + align:start position:0% +then we drafted two two very sort of + + + align:start position:0% +then we drafted two two very sort of +low-level nurses and just brought them + + align:start position:0% +low-level nurses and just brought them + + + align:start position:0% +low-level nurses and just brought them +in we're like right all you have to do + + align:start position:0% +in we're like right all you have to do + + + align:start position:0% +in we're like right all you have to do +is read this checklist go through and + + align:start position:0% +is read this checklist go through and + + + align:start position:0% +is read this checklist go through and +we're just videoing you and I heard + + align:start position:0% +we're just videoing you and I heard + + + align:start position:0% +we're just videoing you and I heard +afterwards he said this checklist is + + align:start position:0% +afterwards he said this checklist is + + + align:start position:0% +afterwards he said this checklist is +really easy I mean I had no training + + align:start position:0% +really easy I mean I had no training + + + align:start position:0% +really easy I mean I had no training +they called me in they videoed me and I + + align:start position:0% +they called me in they videoed me and I + + + align:start position:0% +they called me in they videoed me and I +don't think we're going to have a + + align:start position:0% +don't think we're going to have a + + + align:start position:0% +don't think we're going to have a +problem so it it was actually really + + align:start position:0% +problem so it it was actually really + + + align:start position:0% +problem so it it was actually really +useful doing the video on site and then + + align:start position:0% +useful doing the video on site and then + + + align:start position:0% +useful doing the video on site and then +the other thing that Alvin mentioned was + + align:start position:0% +the other thing that Alvin mentioned was + + + align:start position:0% +the other thing that Alvin mentioned was +role plays I really really think role + + align:start position:0% +role plays I really really think role + + + align:start position:0% +role plays I really really think role +plays for something like this is + + align:start position:0% +plays for something like this is + + + align:start position:0% +plays for something like this is +critical because that's when they un + + align:start position:0% +critical because that's when they un + + + align:start position:0% +critical because that's when they un +understand what's happening and adults + + align:start position:0% +understand what's happening and adults + + + align:start position:0% +understand what's happening and adults +don't want to be sitting like you guys + + align:start position:0% +don't want to be sitting like you guys + + + align:start position:0% +don't want to be sitting like you guys +are sitting listening to me like adults + + align:start position:0% +are sitting listening to me like adults + + + align:start position:0% +are sitting listening to me like adults +want to be on the ground doing stuff and + + align:start position:0% +want to be on the ground doing stuff and + + + align:start position:0% +want to be on the ground doing stuff and +so that's when they really got to + + align:start position:0% +so that's when they really got to + + + align:start position:0% +so that's when they really got to +understand what was uh what the + + align:start position:0% +understand what was uh what the + + + align:start position:0% +understand what was uh what the +checklist was about and so I sort of + + align:start position:0% +checklist was about and so I sort of + + + align:start position:0% +checklist was about and so I sort of +made this like little pyramid so yes the + + align:start position:0% +made this like little pyramid so yes the + + + align:start position:0% +made this like little pyramid so yes the +safe child birth checklist is really the + + align:start position:0% +safe child birth checklist is really the + + + align:start position:0% +safe child birth checklist is really the +main component but the program bit is + + align:start position:0% +main component but the program bit is + + + align:start position:0% +main component but the program bit is +your implementing person so your child + + align:start position:0% +your implementing person so your child + + + align:start position:0% +your implementing person so your child +improve child birth Improvement + + align:start position:0% +improve child birth Improvement + + + align:start position:0% +improve child birth Improvement +coordinator and then we didn't have a + + align:start position:0% +coordinator and then we didn't have a + + + align:start position:0% +coordinator and then we didn't have a +teamwork component on our checklist + + align:start position:0% +teamwork component on our checklist + + + align:start position:0% +teamwork component on our checklist +there wasn't any introduce yourself and + + align:start position:0% +there wasn't any introduce yourself and + + + align:start position:0% +there wasn't any introduce yourself and +we realized that that was critical from + + align:start position:0% +we realized that that was critical from + + + align:start position:0% +we realized that that was critical from +the safe surgery so we said I'll tell + + align:start position:0% +the safe surgery so we said I'll tell + + + align:start position:0% +the safe surgery so we said I'll tell +you what why don't you just get all the + + align:start position:0% +you what why don't you just get all the + + + align:start position:0% +you what why don't you just get all the +labor people together in your facility + + align:start position:0% +labor people together in your facility + + + align:start position:0% +labor people together in your facility +once a day get them to introduce + + align:start position:0% +once a day get them to introduce + + + align:start position:0% +once a day get them to introduce +themselves and just motivate them to use + + align:start position:0% +themselves and just motivate them to use + + + align:start position:0% +themselves and just motivate them to use +the checklist and I thought she wasn't + + align:start position:0% +the checklist and I thought she wasn't + + + align:start position:0% +the checklist and I thought she wasn't +going to do it she thought the idea was + + align:start position:0% +going to do it she thought the idea was + + + align:start position:0% +going to do it she thought the idea was +absolutely rubbish why do I want to know + + align:start position:0% +absolutely rubbish why do I want to know + + + align:start position:0% +absolutely rubbish why do I want to know +the names of the nurses that are doing + + align:start position:0% +the names of the nurses that are doing + + + align:start position:0% +the names of the nurses that are doing +the deliveries at the end she said it + + align:start position:0% +the deliveries at the end she said it + + + align:start position:0% +the deliveries at the end she said it +was fabulous because when she was going + + align:start position:0% +was fabulous because when she was going + + + align:start position:0% +was fabulous because when she was going +home she knew what was going on she said + + align:start position:0% +home she knew what was going on she said + + + align:start position:0% +home she knew what was going on she said +it was the best way of knowing like + + align:start position:0% +it was the best way of knowing like + + + align:start position:0% +it was the best way of knowing like +getting a really quick safety assessment + + align:start position:0% +getting a really quick safety assessment + + + align:start position:0% +getting a really quick safety assessment +of the day like what who with the high + + align:start position:0% +of the day like what who with the high + + + align:start position:0% +of the day like what who with the high +risk patients so I think it's an aspect + + align:start position:0% +risk patients so I think it's an aspect + + + align:start position:0% +risk patients so I think it's an aspect +that she's going to take on now the + + align:start position:0% +that she's going to take on now the + + + align:start position:0% +that she's going to take on now the +study's ended I've only circled these + + align:start position:0% +study's ended I've only circled these + + + align:start position:0% +study's ended I've only circled these +two bits because we actually used um uh + + align:start position:0% +two bits because we actually used um uh + + + align:start position:0% +two bits because we actually used um uh +observers to collect data so we didn't + + align:start position:0% +observers to collect data so we didn't + + + align:start position:0% +observers to collect data so we didn't +want to have like the people who + + align:start position:0% +want to have like the people who + + + align:start position:0% +want to have like the people who +actually using the checklist sort of + + align:start position:0% +actually using the checklist sort of + + + align:start position:0% +actually using the checklist sort of +saying yes we used it and this is what + + align:start position:0% +saying yes we used it and this is what + + + align:start position:0% +saying yes we used it and this is what +we did so we actually drafted in five + + align:start position:0% +we did so we actually drafted in five + + + align:start position:0% +we did so we actually drafted in five +very Junior people to actually observe + + align:start position:0% +very Junior people to actually observe + + + align:start position:0% +very Junior people to actually observe +what they were + + align:start position:0% +what they were + + + align:start position:0% +what they were +doing quickly on the results every + + align:start position:0% +doing quickly on the results every + + + align:start position:0% +doing quickly on the results every +single essential standard that was on + + align:start position:0% +single essential standard that was on + + + align:start position:0% +single essential standard that was on +the checklist improved moved a lot and + + align:start position:0% +the checklist improved moved a lot and + + + align:start position:0% +the checklist improved moved a lot and +I'll show you the graphs and then + + align:start position:0% +I'll show you the graphs and then + + + align:start position:0% +I'll show you the graphs and then +overall they were probably delivering 10 + + align:start position:0% +overall they were probably delivering 10 + + + align:start position:0% +overall they were probably delivering 10 +out the 29 essential standards on + + align:start position:0% +out the 29 essential standards on + + + align:start position:0% +out the 29 essential standards on +average before and afterwards they were + + align:start position:0% +average before and afterwards they were + + + align:start position:0% +average before and afterwards they were +delivering 25 out the 29 standards + + align:start position:0% +delivering 25 out the 29 standards + + + align:start position:0% +delivering 25 out the 29 standards +reliably and even though the study + + align:start position:0% +reliably and even though the study + + + align:start position:0% +reliably and even though the study +wasn't powered for mortality there was a + + align:start position:0% +wasn't powered for mortality there was a + + + align:start position:0% +wasn't powered for mortality there was a +significant drop in the fresh still + + align:start position:0% +significant drop in the fresh still + + + align:start position:0% +significant drop in the fresh still +birth probably because they would + + align:start position:0% +birth probably because they would + + + align:start position:0% +birth probably because they would +actually monitoring the fetus during + + align:start position:0% +actually monitoring the fetus during + + + align:start position:0% +actually monitoring the fetus during +labor and this is some of the fuzzy + + align:start position:0% +labor and this is some of the fuzzy + + + align:start position:0% +labor and this is some of the fuzzy +stuff that's I say fuzzy CU I'm not + + align:start position:0% +stuff that's I say fuzzy CU I'm not + + + align:start position:0% +stuff that's I say fuzzy CU I'm not +quality ative researcher but I went out + + align:start position:0% +quality ative researcher but I went out + + + align:start position:0% +quality ative researcher but I went out +and we were doing interviews and um they + + align:start position:0% +and we were doing interviews and um they + + + align:start position:0% +and we were doing interviews and um they +were talking about how the S the actual + + align:start position:0% +were talking about how the S the actual + + + align:start position:0% +were talking about how the S the actual +checklist as a catalyst for change that + + align:start position:0% +checklist as a catalyst for change that + + + align:start position:0% +checklist as a catalyst for change that +we don't you know it's not what we + + align:start position:0% +we don't you know it's not what we + + + align:start position:0% +we don't you know it's not what we +measure and we don't expect so before I + + align:start position:0% +measure and we don't expect so before I + + + align:start position:0% +measure and we don't expect so before I +told you like the oxytocin and the drugs + + align:start position:0% +told you like the oxytocin and the drugs + + + align:start position:0% +told you like the oxytocin and the drugs +weren't available well there's something + + align:start position:0% +weren't available well there's something + + + align:start position:0% +weren't available well there's something +about being on the checklist that helps + + align:start position:0% +about being on the checklist that helps + + + align:start position:0% +about being on the checklist that helps +the institution say well oh okay these + + align:start position:0% +the institution say well oh okay these + + + align:start position:0% +the institution say well oh okay these +are really important items we're going + + align:start position:0% +are really important items we're going + + + align:start position:0% +are really important items we're going +to focus on these and the availability + + align:start position:0% +to focus on these and the availability + + + align:start position:0% +to focus on these and the availability +increases then they've instituted + + align:start position:0% +increases then they've instituted + + + align:start position:0% +increases then they've instituted +different changes is like well she said + + align:start position:0% +different changes is like well she said + + + align:start position:0% +different changes is like well she said +well you want us to do a check 1 hour + + align:start position:0% +well you want us to do a check 1 hour + + + align:start position:0% +well you want us to do a check 1 hour +after birth but the woman's all over the + + align:start position:0% +after birth but the woman's all over the + + + align:start position:0% +after birth but the woman's all over the +hospital at that point so they shifted + + align:start position:0% +hospital at that point so they shifted + + + align:start position:0% +hospital at that point so they shifted +things around this was just a nurse on + + align:start position:0% +things around this was just a nurse on + + + align:start position:0% +things around this was just a nurse on +the ground she said I'm just going to + + align:start position:0% +the ground she said I'm just going to + + + align:start position:0% +the ground she said I'm just going to +create a bay and there every woman who + + align:start position:0% +create a bay and there every woman who + + + align:start position:0% +create a bay and there every woman who +delivers is going to go there she's + + align:start position:0% +delivers is going to go there she's + + + align:start position:0% +delivers is going to go there she's +going to have her checklist done her + + align:start position:0% +going to have her checklist done her + + + align:start position:0% +going to have her checklist done her +check done at now and then she'll move + + align:start position:0% +check done at now and then she'll move + + + align:start position:0% +check done at now and then she'll move +to the postnatal um Wards and you know + + align:start position:0% +to the postnatal um Wards and you know + + + align:start position:0% +to the postnatal um Wards and you know +wherever she's going to go so there were + + align:start position:0% +wherever she's going to go so there were + + + align:start position:0% +wherever she's going to go so there were +lots of little changes that happened to + + align:start position:0% +lots of little changes that happened to + + + align:start position:0% +lots of little changes that happened to +enable the checklist to be effectively + + align:start position:0% +enable the checklist to be effectively + + + align:start position:0% +enable the checklist to be effectively +delivered so it's sort of like + + align:start position:0% +delivered so it's sort of like + + + align:start position:0% +delivered so it's sort of like +operations management but they LED on + + align:start position:0% +operations management but they LED on + + + align:start position:0% +operations management but they LED on +that that the second thing I noticed + + align:start position:0% +that that the second thing I noticed + + + align:start position:0% +that that the second thing I noticed +when I was out there and the nurses said + + align:start position:0% +when I was out there and the nurses said + + + align:start position:0% +when I was out there and the nurses said +was the patients started asking whether + + align:start position:0% +was the patients started asking whether + + + align:start position:0% +was the patients started asking whether +this facility had become a private + + align:start position:0% +this facility had become a private + + + align:start position:0% +this facility had become a private +facility because they noticed that their + + align:start position:0% +facility because they noticed that their + + + align:start position:0% +facility because they noticed that their +care was improving and would they have + + align:start position:0% +care was improving and would they have + + + align:start position:0% +care was improving and would they have +to pay more and it was a great feedback + + align:start position:0% +to pay more and it was a great feedback + + + align:start position:0% +to pay more and it was a great feedback +mechanism because that made the nurses + + align:start position:0% +mechanism because that made the nurses + + + align:start position:0% +mechanism because that made the nurses +happier and at the end of the day you + + align:start position:0% +happier and at the end of the day you + + + align:start position:0% +happier and at the end of the day you +want to provide good care but when your + + align:start position:0% +want to provide good care but when your + + + align:start position:0% +want to provide good care but when your +workloads crazy you're just providing + + align:start position:0% +workloads crazy you're just providing + + + align:start position:0% +workloads crazy you're just providing +whatever and now they had this check + + align:start position:0% +whatever and now they had this check + + + align:start position:0% +whatever and now they had this check +they said this is great we do this and + + align:start position:0% +they said this is great we do this and + + + align:start position:0% +they said this is great we do this and +we provide good care and the patients + + align:start position:0% +we provide good care and the patients + + + align:start position:0% +we provide good care and the patients +are loving us and they were giving a few + + align:start position:0% +are loving us and they were giving a few + + + align:start position:0% +are loving us and they were giving a few +extra Rupees at the end you know backand + + align:start position:0% +extra Rupees at the end you know backand + + + align:start position:0% +extra Rupees at the end you know backand +deals and the ex the other thing was + + align:start position:0% +deals and the ex the other thing was + + + align:start position:0% +deals and the ex the other thing was +that the checklist was beginning to be + + align:start position:0% +that the checklist was beginning to be + + + align:start position:0% +that the checklist was beginning to be +used as a Handover tool so normally if + + align:start position:0% +used as a Handover tool so normally if + + + align:start position:0% +used as a Handover tool so normally if +they did a bit of a tag team it' be like + + align:start position:0% +they did a bit of a tag team it' be like + + + align:start position:0% +they did a bit of a tag team it' be like +okay woman in labor had three children + + align:start position:0% +okay woman in labor had three children + + + align:start position:0% +okay woman in labor had three children +before buy them off to lunch and now + + align:start position:0% +before buy them off to lunch and now + + + align:start position:0% +before buy them off to lunch and now +they were saying oh actually no I did + + align:start position:0% +they were saying oh actually no I did + + + align:start position:0% +they were saying oh actually no I did +check that and actually High she's got + + align:start position:0% +check that and actually High she's got + + + align:start position:0% +check that and actually High she's got +high blood pressure and I think she + + align:start position:0% +high blood pressure and I think she + + + align:start position:0% +high blood pressure and I think she +might be at risk of bleeding so even + + align:start position:0% +might be at risk of bleeding so even + + + align:start position:0% +might be at risk of bleeding so even +their communication was improving and + + align:start position:0% +their communication was improving and + + + align:start position:0% +their communication was improving and +these are changes that you don't really + + align:start position:0% +these are changes that you don't really + + + align:start position:0% +these are changes that you don't really +expect but happen because you've + + align:start position:0% +expect but happen because you've + + + align:start position:0% +expect but happen because you've +introduced an innovation I don't want + + align:start position:0% +introduced an innovation I don't want + + + align:start position:0% +introduced an innovation I don't want +you to look at any of the detail on + + align:start position:0% +you to look at any of the detail on + + + align:start position:0% +you to look at any of the detail on +apart from dark blue is pre and light + + align:start position:0% +apart from dark blue is pre and light + + + align:start position:0% +apart from dark blue is pre and light +blue is post and you can see that some + + align:start position:0% +blue is post and you can see that some + + + align:start position:0% +blue is post and you can see that some +have drastically improved hand hygiene I + + align:start position:0% +have drastically improved hand hygiene I + + + align:start position:0% +have drastically improved hand hygiene I +wash your hands with soap and water and + + align:start position:0% +wash your hands with soap and water and + + + align:start position:0% +wash your hands with soap and water and +use gloves 3% before 99% after I mean + + align:start position:0% +use gloves 3% before 99% after I mean + + + align:start position:0% +use gloves 3% before 99% after I mean +some of the things they were doing fine + + align:start position:0% +some of the things they were doing fine + + + align:start position:0% +some of the things they were doing fine +before but even though statistically + + align:start position:0% +before but even though statistically + + + align:start position:0% +before but even though statistically +improved every single item improved + + align:start position:0% +improved every single item improved + + + align:start position:0% +improved every single item improved +hugely and people say well that's fair + + align:start position:0% +hugely and people say well that's fair + + + align:start position:0% +hugely and people say well that's fair +enough but what about sustainability + + align:start position:0% +enough but what about sustainability + + + align:start position:0% +enough but what about sustainability +you're in a study environment so I went + + align:start position:0% +you're in a study environment so I went + + + align:start position:0% +you're in a study environment so I went +3 weeks later after the study and um + + align:start position:0% +3 weeks later after the study and um + + + align:start position:0% +3 weeks later after the study and um +we'd said we wouldn't provide checklist + + align:start position:0% +we'd said we wouldn't provide checklist + + + align:start position:0% +we'd said we wouldn't provide checklist +like if they wanted the checklist they + + align:start position:0% +like if they wanted the checklist they + + + align:start position:0% +like if they wanted the checklist they +the institution had to buy them but the + + align:start position:0% +the institution had to buy them but the + + + align:start position:0% +the institution had to buy them but the +chief medical officer was away and it's + + align:start position:0% +chief medical officer was away and it's + + + align:start position:0% +chief medical officer was away and it's +a very centralized process and um so + + align:start position:0% +a very centralized process and um so + + + align:start position:0% +a very centralized process and um so +there were no checklists I said oh what + + align:start position:0% +there were no checklists I said oh what + + + align:start position:0% +there were no checklists I said oh what +have you been doing and I said well for + + align:start position:0% +have you been doing and I said well for + + + align:start position:0% +have you been doing and I said well for +the first week we use posters but we + + align:start position:0% +the first week we use posters but we + + + align:start position:0% +the first week we use posters but we +really think it's about the piece of + + align:start position:0% +really think it's about the piece of + + + align:start position:0% +really think it's about the piece of +paper and I said so what have you done + + align:start position:0% +paper and I said so what have you done + + + align:start position:0% +paper and I said so what have you done +and they said well we just pulled our + + align:start position:0% +and they said well we just pulled our + + + align:start position:0% +and they said well we just pulled our +money we had a little bit of money saved + + align:start position:0% +money we had a little bit of money saved + + + align:start position:0% +money we had a little bit of money saved +up and every nurse gave I don't know + + align:start position:0% +up and every nurse gave I don't know + + + align:start position:0% +up and every nurse gave I don't know +must have been like 10 rupees or + + align:start position:0% +must have been like 10 rupees or + + + align:start position:0% +must have been like 10 rupees or +something and they went to the Xerox + + align:start position:0% +something and they went to the Xerox + + + align:start position:0% +something and they went to the Xerox +Center and photocopy checklists for + + align:start position:0% +Center and photocopy checklists for + + + align:start position:0% +Center and photocopy checklists for +themselves they said we might get the + + align:start position:0% +themselves they said we might get the + + + align:start position:0% +themselves they said we might get the +money back we might not but we're + + align:start position:0% +money back we might not but we're + + + align:start position:0% +money back we might not but we're +providing better care this way I like + + align:start position:0% +providing better care this way I like + + + align:start position:0% +providing better care this way I like +wow and they don't get paid a lot and + + align:start position:0% +wow and they don't get paid a lot and + + + align:start position:0% +wow and they don't get paid a lot and +they're putting their own money towards + + align:start position:0% +they're putting their own money towards + + + align:start position:0% +they're putting their own money towards +something that's + + align:start position:0% +something that's + + + align:start position:0% +something that's +acceptability um and next steps so yes + + align:start position:0% +acceptability um and next steps so yes + + + align:start position:0% +acceptability um and next steps so yes +there's the randomized control trial um + + align:start position:0% +there's the randomized control trial um + + + align:start position:0% +there's the randomized control trial um +but lots of people are saying well do we + + align:start position:0% +but lots of people are saying well do we + + + align:start position:0% +but lots of people are saying well do we +really have to wait for three years + + align:start position:0% +really have to wait for three years + + + align:start position:0% +really have to wait for three years +before we get this checklist out like + + align:start position:0% +before we get this checklist out like + + + align:start position:0% +before we get this checklist out like +what's the harm I looked at the cesarian + + align:start position:0% +what's the harm I looked at the cesarian + + + align:start position:0% +what's the harm I looked at the cesarian +section rates they're not going up + + align:start position:0% +section rates they're not going up + + + align:start position:0% +section rates they're not going up +you're not going to cause death and it's + + align:start position:0% +you're not going to cause death and it's + + + align:start position:0% +you're not going to cause death and it's +a question and it's a question for you + + align:start position:0% +a question and it's a question for you + + + align:start position:0% +a question and it's a question for you +guys and it's a question for the field + + align:start position:0% +guys and it's a question for the field + + + align:start position:0% +guys and it's a question for the field +like do we have to wait for the RCT + + align:start position:0% +like do we have to wait for the RCT + + + align:start position:0% +like do we have to wait for the RCT +before simple Innovations like this are + + align:start position:0% +before simple Innovations like this are + + + align:start position:0% +before simple Innovations like this are +rolled out oh sorry randomized control + + align:start position:0% +rolled out oh sorry randomized control + + + align:start position:0% +rolled out oh sorry randomized control +Tri so it's like you know the big + + align:start position:0% +Tri so it's like you know the big + + + align:start position:0% +Tri so it's like you know the big +shebang that the academics like well I + + align:start position:0% +shebang that the academics like well I + + + align:start position:0% +shebang that the academics like well I +don't know I don't know the answer to + + align:start position:0% +don't know I don't know the answer to + + + align:start position:0% +don't know I don't know the answer to +this and I I I think there is um an + + align:start position:0% +this and I I I think there is um an + + + align:start position:0% +this and I I I think there is um an +argument to be had and then the use of + + align:start position:0% +argument to be had and then the use of + + + align:start position:0% +argument to be had and then the use of +technology and again it's something that + + align:start position:0% +technology and again it's something that + + + align:start position:0% +technology and again it's something that +you can answer better than us I actually + + align:start position:0% +you can answer better than us I actually + + + align:start position:0% +you can answer better than us I actually +think that yes the checklist could be + + align:start position:0% +think that yes the checklist could be + + + align:start position:0% +think that yes the checklist could be +put on a mobile phone like yes that's + + align:start position:0% +put on a mobile phone like yes that's + + + align:start position:0% +put on a mobile phone like yes that's +one thing but you know I think there's + + align:start position:0% +one thing but you know I think there's + + + align:start position:0% +one thing but you know I think there's +more than that like could it be used for + + align:start position:0% +more than that like could it be used for + + + align:start position:0% +more than that like could it be used for +data collect ction could it be used for + + align:start position:0% +data collect ction could it be used for + + + align:start position:0% +data collect ction could it be used for +training like where does technology fit + + align:start position:0% +training like where does technology fit + + + align:start position:0% +training like where does technology fit +in with these Innovations and it's a + + align:start position:0% +in with these Innovations and it's a + + + align:start position:0% +in with these Innovations and it's a +thing that hasn't been sort of + + align:start position:0% +thing that hasn't been sort of + + + align:start position:0% +thing that hasn't been sort of +considered in you know the to g day + + align:start position:0% +considered in you know the to g day + + + align:start position:0% +considered in you know the to g day +group and I think it's you know I'm sure + + align:start position:0% +group and I think it's you know I'm sure + + + align:start position:0% +group and I think it's you know I'm sure +Leo's thought about this like how do we + + align:start position:0% +Leo's thought about this like how do we + + + align:start position:0% +Leo's thought about this like how do we +start using innov technology to support + + align:start position:0% +start using innov technology to support + + + align:start position:0% +start using innov technology to support +these + + align:start position:0% +these + + + align:start position:0% +these +Innovations so that's a quick run + + align:start position:0% +Innovations so that's a quick run + + + align:start position:0% +Innovations so that's a quick run +through the safe child with checklist \ No newline at end of file diff --git a/mhLI51d9LDc.txt b/mhLI51d9LDc.txt new file mode 100644 index 0000000000000000000000000000000000000000..5e6df7975a6d3026ce728725c491a9eccd1d1bfb --- /dev/null +++ b/mhLI51d9LDc.txt @@ -0,0 +1,7600 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +to view additional materials from + + align:start position:0% +to view additional materials from + + + align:start position:0% +to view additional materials from +hundreds of MIT courses visit MIT open + + align:start position:0% +hundreds of MIT courses visit MIT open + + + align:start position:0% +hundreds of MIT courses visit MIT open +courseware at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu + + align:start position:0% +ocw.mit.edu + + + align:start position:0% +ocw.mit.edu +okay uh so this is a fun lecture this is + + align:start position:0% +okay uh so this is a fun lecture this is + + + align:start position:0% +okay uh so this is a fun lecture this is +the lecture where understanding uh the + + align:start position:0% +the lecture where understanding uh the + + + align:start position:0% +the lecture where understanding uh the +gradient which we did last time + + align:start position:0% +gradient which we did last time + + + align:start position:0% +gradient which we did last time +the Divergence that we almost completed + + align:start position:0% +the Divergence that we almost completed + + + align:start position:0% +the Divergence that we almost completed +those two pieces now come together into + + align:start position:0% +those two pieces now come together into + + + align:start position:0% +those two pieces now come together into +the Lassa equation and it's just things + + align:start position:0% +the Lassa equation and it's just things + + + align:start position:0% +the Lassa equation and it's just things +work in a fantastic way so I enjoy this + + align:start position:0% +work in a fantastic way so I enjoy this + + + align:start position:0% +work in a fantastic way so I enjoy this +one so the the result will be that we've + + align:start position:0% +one so the the result will be that we've + + + align:start position:0% +one so the the result will be that we've +have the potential function U that we've + + align:start position:0% +have the potential function U that we've + + + align:start position:0% +have the potential function U that we've +spoken about and take its gradient then + + align:start position:0% +spoken about and take its gradient then + + + align:start position:0% +spoken about and take its gradient then +now is coming a stream function s that's + + align:start position:0% +now is coming a stream function s that's + + + align:start position:0% +now is coming a stream function s that's +connected with the Divergence when the + + align:start position:0% +connected with the Divergence when the + + + align:start position:0% +connected with the Divergence when the +Divergence is zero that there's a + + align:start position:0% +Divergence is zero that there's a + + + align:start position:0% +Divergence is zero that there's a +something called a stream function s and + + align:start position:0% +something called a stream function s and + + + align:start position:0% +something called a stream function s and +these the connections between those two + + align:start position:0% +these the connections between those two + + + align:start position:0% +these the connections between those two +functions U and S are are crucial and + + align:start position:0% +functions U and S are are crucial and + + + align:start position:0% +functions U and S are are crucial and +and and connecting uh gradient to + + align:start position:0% +and and connecting uh gradient to + + + align:start position:0% +and and connecting uh gradient to +Divergence will take us to ll's equation + + align:start position:0% +Divergence will take us to ll's equation + + + align:start position:0% +Divergence will take us to ll's equation +and then you'll see the special special + + align:start position:0% +and then you'll see the special special + + + align:start position:0% +and then you'll see the special special +role of X Plus i y in in 2D so this is + + align:start position:0% +role of X Plus i y in in 2D so this is + + + align:start position:0% +role of X Plus i y in in 2D so this is +in two Dimensions okay so let me begin + + align:start position:0% +in two Dimensions okay so let me begin + + + align:start position:0% +in two Dimensions okay so let me begin +with with the Divergence this is the + + align:start position:0% +with with the Divergence this is the + + + align:start position:0% +with with the Divergence this is the +Divergence of w of + + align:start position:0% +Divergence of w of + + + align:start position:0% +Divergence of w of +course and uh solve + + align:start position:0% +course and uh solve + + + align:start position:0% +course and uh solve +it as just as we wanted to solve Kirk's + + align:start position:0% +it as just as we wanted to solve Kirk's + + + align:start position:0% +it as just as we wanted to solve Kirk's +current law a transpose W equals z so + + align:start position:0% +current law a transpose W equals z so + + + align:start position:0% +current law a transpose W equals z so +now in the continuous case we want to + + align:start position:0% +now in the continuous case we want to + + + align:start position:0% +now in the continuous case we want to +find solutions to the we want to find + + align:start position:0% +find solutions to the we want to find + + + align:start position:0% +find solutions to the we want to find +Divergence free Fields Source free + + align:start position:0% +Divergence free Fields Source free + + + align:start position:0% +Divergence free Fields Source free +Fields you could say that's about the + + align:start position:0% +Fields you could say that's about the + + + align:start position:0% +Fields you could say that's about the +best word we have Divergence free + + align:start position:0% +best word we have Divergence free + + + align:start position:0% +best word we have Divergence free +meaning there is no Divergence the the + + align:start position:0% +meaning there is no Divergence the the + + + align:start position:0% +meaning there is no Divergence the the +the okay so what have we got here we've + + align:start position:0% +the okay so what have we got here we've + + + align:start position:0% +the okay so what have we got here we've +got one equation in two + + align:start position:0% +got one equation in two + + + align:start position:0% +got one equation in two +unknowns last time with the gradient + + align:start position:0% +unknowns last time with the gradient + + + align:start position:0% +unknowns last time with the gradient +business we had two equations for you + + align:start position:0% +business we had two equations for you + + + align:start position:0% +business we had two equations for you +and only that one unknown now we've got + + align:start position:0% +and only that one unknown now we've got + + + align:start position:0% +and only that one unknown now we've got +one equation two unknowns because we're + + align:start position:0% +one equation two unknowns because we're + + + align:start position:0% +one equation two unknowns because we're +looking at the transpose so now I want + + align:start position:0% +looking at the transpose so now I want + + + align:start position:0% +looking at the transpose so now I want +so there should be a lot of solutions + + align:start position:0% +so there should be a lot of solutions + + + align:start position:0% +so there should be a lot of solutions +right if you give me a W1 then probably + + align:start position:0% +right if you give me a W1 then probably + + + align:start position:0% +right if you give me a W1 then probably +I'll be able to find a W2 but there's a + + align:start position:0% +I'll be able to find a W2 but there's a + + + align:start position:0% +I'll be able to find a W2 but there's a +neat way to describe the solutions to + + align:start position:0% +neat way to describe the solutions to + + + align:start position:0% +neat way to describe the solutions to +that equation the Divergence free Fields + + align:start position:0% +that equation the Divergence free Fields + + + align:start position:0% +that equation the Divergence free Fields +it's to introduce something called a + + align:start position:0% +it's to introduce something called a + + + align:start position:0% +it's to introduce something called a +source function a stream function sorry + + align:start position:0% +source function a stream function sorry + + + align:start position:0% +source function a stream function sorry +stream + + align:start position:0% +stream + + + align:start position:0% +stream +function okay and now the idea will be + + align:start position:0% +function okay and now the idea will be + + + align:start position:0% +function okay and now the idea will be +that if I let so I'll try let me try I + + align:start position:0% +that if I let so I'll try let me try I + + + align:start position:0% +that if I let so I'll try let me try I +take any function s ofx and Y any + + align:start position:0% +take any function s ofx and Y any + + + align:start position:0% +take any function s ofx and Y any +function whatever so now I try + + align:start position:0% +function whatever so now I try + + + align:start position:0% +function whatever so now I try +let + + align:start position:0% +let + + + align:start position:0% +let +W1 be DS Dy so so my maybe I should say + + align:start position:0% +W1 be DS Dy so so my maybe I should say + + + align:start position:0% +W1 be DS Dy so so my maybe I should say +yeah maybe I should go this way I'm I'm + + align:start position:0% +yeah maybe I should go this way I'm I'm + + + align:start position:0% +yeah maybe I should go this way I'm I'm +I'm looking for Solutions okay so I take + + align:start position:0% +I'm looking for Solutions okay so I take + + + align:start position:0% +I'm looking for Solutions okay so I take +any function s i take its y derivative + + align:start position:0% +any function s i take its y derivative + + + align:start position:0% +any function s i take its y derivative +to be + + align:start position:0% +to be + + + align:start position:0% +to be +W1 and you can tell me what W2 has to be + + align:start position:0% +W1 and you can tell me what W2 has to be + + + align:start position:0% +W1 and you can tell me what W2 has to be +so let me see so so uh if if W1 is D sdy + + align:start position:0% +so let me see so so uh if if W1 is D sdy + + + align:start position:0% +so let me see so so uh if if W1 is D sdy +this will be what this will be the + + align:start position:0% +this will be what this will be the + + + align:start position:0% +this will be what this will be the +second the X derivative of the Y + + align:start position:0% +second the X derivative of the Y + + + align:start position:0% +second the X derivative of the Y +derivative right if W1 is the Y + + align:start position:0% +derivative right if W1 is the Y + + + align:start position:0% +derivative right if W1 is the Y +derivative then when I take the X + + align:start position:0% +derivative then when I take the X + + + align:start position:0% +derivative then when I take the X +derivative I've got this cross + + align:start position:0% +derivative I've got this cross + + + align:start position:0% +derivative I've got this cross +derivative so what would be the smart + + align:start position:0% +derivative so what would be the smart + + + align:start position:0% +derivative so what would be the smart +choice for W2 so I'll say then then W2 + + align:start position:0% +choice for W2 so I'll say then then W2 + + + align:start position:0% +choice for W2 so I'll say then then W2 +will be what what will the now I've sort + + align:start position:0% +will be what what will the now I've sort + + + align:start position:0% +will be what what will the now I've sort +of said what W1 is what's the W2 that + + align:start position:0% +of said what W1 is what's the W2 that + + + align:start position:0% +of said what W1 is what's the W2 that +goes with it well it's whatever it takes + + align:start position:0% +goes with it well it's whatever it takes + + + align:start position:0% +goes with it well it's whatever it takes +to cancel this I want this to be in + + align:start position:0% +to cancel this I want this to be in + + + align:start position:0% +to cancel this I want this to be in +other words I want it to be get zero so + + align:start position:0% +other words I want it to be get zero so + + + align:start position:0% +other words I want it to be get zero so +this should be the second derivative of + + align:start position:0% +this should be the second derivative of + + + align:start position:0% +this should be the second derivative of +s and what am I going to put now Dy DX + + align:start position:0% +s and what am I going to put now Dy DX + + + align:start position:0% +s and what am I going to put now Dy DX +I'm using the same very crucial fact + + align:start position:0% +I'm using the same very crucial fact + + + align:start position:0% +I'm using the same very crucial fact +that the cross derivative can be in + + align:start position:0% +that the cross derivative can be in + + + align:start position:0% +that the cross derivative can be in +either order so what do I see for + + align:start position:0% +either order so what do I see for + + + align:start position:0% +either order so what do I see for +W2 do you see what W2 is this is + + align:start position:0% +W2 do you see what W2 is this is + + + align:start position:0% +W2 do you see what W2 is this is +supposed to match that that there's a + + align:start position:0% +supposed to match that that there's a + + + align:start position:0% +supposed to match that that there's a +minus sign W2 is + + align:start position:0% +minus sign W2 is + + + align:start position:0% +minus sign W2 is +What minus + + align:start position:0% +What minus + + + align:start position:0% +What minus +DSD X right minus DS DX that's that's + + align:start position:0% +DSD X right minus DS DX that's that's + + + align:start position:0% +DSD X right minus DS DX that's that's +the minus DS DX if if I take any + + align:start position:0% +the minus DS DX if if I take any + + + align:start position:0% +the minus DS DX if if I take any +function S I let W1 be its y derivative + + align:start position:0% +function S I let W1 be its y derivative + + + align:start position:0% +function S I let W1 be its y derivative +and W2 be its minus its X derivative + + align:start position:0% +and W2 be its minus its X derivative + + + align:start position:0% +and W2 be its minus its X derivative +then the Divergence will be zero because + + align:start position:0% +then the Divergence will be zero because + + + align:start position:0% +then the Divergence will be zero because +it'll I'll have the SEC the cross + + align:start position:0% +it'll I'll have the SEC the cross + + + align:start position:0% +it'll I'll have the SEC the cross +derivative minus the cross derivative of + + align:start position:0% +derivative minus the cross derivative of + + + align:start position:0% +derivative minus the cross derivative of +course that'll be zero so these will be + + align:start position:0% +course that'll be zero so these will be + + + align:start position:0% +course that'll be zero so these will be +my w1s my W's W1 W2 coming from s so I + + align:start position:0% +my w1s my W's W1 W2 coming from s so I + + + align:start position:0% +my w1s my W's W1 W2 coming from s so I +have what I expect with two unknowns + + align:start position:0% +have what I expect with two unknowns + + + align:start position:0% +have what I expect with two unknowns +only one equation I've got lots of + + align:start position:0% +only one equation I've got lots of + + + align:start position:0% +only one equation I've got lots of +solutions I create any function s and + + align:start position:0% +solutions I create any function s and + + + align:start position:0% +solutions I create any function s and +that will be one so that's a a stream + + align:start position:0% +that will be one so that's a a stream + + + align:start position:0% +that will be one so that's a a stream +function and it has a physical meaning + + align:start position:0% +function and it has a physical meaning + + + align:start position:0% +function and it has a physical meaning +so we get to see it and it has a + + align:start position:0% +so we get to see it and it has a + + + align:start position:0% +so we get to see it and it has a +fantastic connection to the potential + + align:start position:0% +fantastic connection to the potential + + + align:start position:0% +fantastic connection to the potential +when when so up to now so this is now + + align:start position:0% +when when so up to now so this is now + + + align:start position:0% +when when so up to now so this is now +the moment the Pieces come together up + + align:start position:0% +the moment the Pieces come together up + + + align:start position:0% +the moment the Pieces come together up +to now we had the Divergence and the + + align:start position:0% +to now we had the Divergence and the + + + align:start position:0% +to now we had the Divergence and the +gradient separately so up to now what we + + align:start position:0% +gradient separately so up to now what we + + + align:start position:0% +gradient separately so up to now what we +had was we started with a potential U + + align:start position:0% +had was we started with a potential U + + + align:start position:0% +had was we started with a potential U +and we went to v i I called it V for + + align:start position:0% +and we went to v i I called it V for + + + align:start position:0% +and we went to v i I called it V for +this application DX + + align:start position:0% + + + + align:start position:0% + +Dy okay and now over on this side I had + + align:start position:0% +Dy okay and now over on this side I had + + + align:start position:0% +Dy okay and now over on this side I had +the Divergence of w equals z + + align:start position:0% +the Divergence of w equals z + + + align:start position:0% +the Divergence of w equals z +and that led me to W being what we've + + align:start position:0% +and that led me to W being what we've + + + align:start position:0% +and that led me to W being what we've +just said D + + align:start position:0% +just said D + + + align:start position:0% +just said D +sdy and minus + + align:start position:0% +sdy and minus + + + align:start position:0% +sdy and minus +dsdx okay two separate pictures + + align:start position:0% +dsdx okay two separate pictures + + + align:start position:0% +dsdx okay two separate pictures +now we're going to connect the framework + + align:start position:0% +now we're going to connect the framework + + + align:start position:0% +now we're going to connect the framework +going to give the connection between V + + align:start position:0% +going to give the connection between V + + + align:start position:0% +going to give the connection between V +and W and the connection will be the + + align:start position:0% +and W and the connection will be the + + + align:start position:0% +and W and the connection will be the +easiest possible they'll be equal so the + + align:start position:0% +easiest possible they'll be equal so the + + + align:start position:0% +easiest possible they'll be equal so the +C in our framework is the identity + + align:start position:0% +C in our framework is the identity + + + align:start position:0% +C in our framework is the identity +I want to say I want to look at the our + + align:start position:0% +I want to say I want to look at the our + + + align:start position:0% +I want to say I want to look at the our +framework when C is C is the + + align:start position:0% +framework when C is C is the + + + align:start position:0% +framework when C is C is the +identity so V and W are the same in + + align:start position:0% +identity so V and W are the same in + + + align:start position:0% +identity so V and W are the same in +other words what equation do we get then + + align:start position:0% +other words what equation do we get then + + + align:start position:0% +other words what equation do we get then +we started with u we take the gradient + + align:start position:0% +we started with u we take the gradient + + + align:start position:0% +we started with u we take the gradient +of U that's V we go over here and we + + align:start position:0% +of U that's V we go over here and we + + + align:start position:0% +of U that's V we go over here and we +still have the gradient of U because now + + align:start position:0% +still have the gradient of U because now + + + align:start position:0% +still have the gradient of U because now +it's this was this is the V and now it's + + align:start position:0% +it's this was this is the V and now it's + + + align:start position:0% +it's this was this is the V and now it's +also the W and then we take the what do + + align:start position:0% +also the W and then we take the what do + + + align:start position:0% +also the W and then we take the what do +we take minus the diver + + align:start position:0% +we take minus the diver + + + align:start position:0% +we take minus the diver +of the gradient of U equals let's say F + + align:start position:0% +of the gradient of U equals let's say F + + + align:start position:0% +of the gradient of U equals let's say F +should we say F to make something happen + + align:start position:0% +should we say F to make something happen + + + align:start position:0% +should we say F to make something happen +or + + align:start position:0% +or + + + align:start position:0% +or +zero uh I'll say zero I'll say + + align:start position:0% +zero uh I'll say zero I'll say + + + align:start position:0% +zero uh I'll say zero I'll say +zero yeah because zero is the one that + + align:start position:0% +zero yeah because zero is the one that + + + align:start position:0% +zero yeah because zero is the one that +gives ll's equation the official name + + align:start position:0% +gives ll's equation the official name + + + align:start position:0% +gives ll's equation the official name +would be that's ll's equation do you + + align:start position:0% +would be that's ll's equation do you + + + align:start position:0% +would be that's ll's equation do you +recognize + + align:start position:0% +recognize + + + align:start position:0% +recognize +it we better write it out properly the + + align:start position:0% +it we better write it out properly the + + + align:start position:0% +it we better write it out properly the +Divergence of the gradient is the lassan + + align:start position:0% +Divergence of the gradient is the lassan + + + align:start position:0% +Divergence of the gradient is the lassan +so so this is + + align:start position:0% + + + + align:start position:0% + +llas famous + + align:start position:0% +llas famous + + + align:start position:0% +llas famous +equation steady state type of equation + + align:start position:0% +equation steady state type of equation + + + align:start position:0% +equation steady state type of equation +it goes with steady state problems let's + + align:start position:0% +it goes with steady state problems let's + + + align:start position:0% +it goes with steady state problems let's +just figure out what this is we've got + + align:start position:0% +just figure out what this is we've got + + + align:start position:0% +just figure out what this is we've got +so w + + align:start position:0% +so w + + + align:start position:0% +so w +is since these are the same W is now DX + + align:start position:0% +is since these are the same W is now DX + + + align:start position:0% +is since these are the same W is now DX +duud y it's the gradient now what + + align:start position:0% +duud y it's the gradient now what + + + align:start position:0% +duud y it's the gradient now what +happens do you see what happens when I + + align:start position:0% +happens do you see what happens when I + + + align:start position:0% +happens do you see what happens when I +take the Divergence of the gradient the + + align:start position:0% +take the Divergence of the gradient the + + + align:start position:0% +take the Divergence of the gradient the +Divergence of this W what what's the + + align:start position:0% +Divergence of this W what what's the + + + align:start position:0% +Divergence of this W what what's the +what I just want to write that equation + + align:start position:0% +what I just want to write that equation + + + align:start position:0% +what I just want to write that equation +out it's + + align:start position:0% +out it's + + + align:start position:0% +out it's +crucial I need + + align:start position:0% +crucial I need + + + align:start position:0% +crucial I need +a brilliant colors and lights shining + + align:start position:0% +a brilliant colors and lights shining + + + align:start position:0% +a brilliant colors and lights shining +now for this uh what goes in there + + align:start position:0% +now for this uh what goes in there + + + align:start position:0% +now for this uh what goes in there +because I want to take the Divergence of + + align:start position:0% +because I want to take the Divergence of + + + align:start position:0% +because I want to take the Divergence of +the gradient so what does that mean I + + align:start position:0% +the gradient so what does that mean I + + + align:start position:0% +the gradient so what does that mean I +take the X derivative of the first + + align:start position:0% +take the X derivative of the first + + + align:start position:0% +take the X derivative of the first +component plus the Y derivative of the + + align:start position:0% +component plus the Y derivative of the + + + align:start position:0% +component plus the Y derivative of the +second component the minus sign is not + + align:start position:0% +second component the minus sign is not + + + align:start position:0% +second component the minus sign is not +going to matter with a zero on the right + + align:start position:0% +going to matter with a zero on the right + + + align:start position:0% +going to matter with a zero on the right +hand side I could cancel the minus so + + align:start position:0% +hand side I could cancel the minus so + + + align:start position:0% +hand side I could cancel the minus so +but let me say it again the Divergence + + align:start position:0% +but let me say it again the Divergence + + + align:start position:0% +but let me say it again the Divergence +is it applies to a vector I've got a + + align:start position:0% +is it applies to a vector I've got a + + + align:start position:0% +is it applies to a vector I've got a +vector I take the X component of the + + align:start position:0% +vector I take the X component of the + + + align:start position:0% +vector I take the X component of the +first of W1 so that'll give me DC U + + align:start position:0% +first of W1 so that'll give me DC U + + + align:start position:0% +first of W1 so that'll give me DC U +dx2 and I take the Y derivative I should + + align:start position:0% +dx2 and I take the Y derivative I should + + + align:start position:0% +dx2 and I take the Y derivative I should +have said derivative y derivative of the + + align:start position:0% +have said derivative y derivative of the + + + align:start position:0% +have said derivative y derivative of the +second component and the Y derivative of + + align:start position:0% +second component and the Y derivative of + + + align:start position:0% +second component and the Y derivative of +that is DC u d + + align:start position:0% +that is DC u d + + + align:start position:0% +that is DC u d +y^2 and I get zero so that's lass's + + align:start position:0% +y^2 and I get zero so that's lass's + + + align:start position:0% +y^2 and I get zero so that's lass's +equation you see that the whole idea is + + align:start position:0% +equation you see that the whole idea is + + + align:start position:0% +equation you see that the whole idea is +lass's equation in in in working with + + align:start position:0% +lass's equation in in in working with + + + align:start position:0% +lass's equation in in in working with +Lassa equation we have three elements + + align:start position:0% +Lassa equation we have three elements + + + align:start position:0% +Lassa equation we have three elements +here the gradient comes in the + + align:start position:0% +here the gradient comes in the + + + align:start position:0% +here the gradient comes in the +Divergence comes in and equality comes + + align:start position:0% +Divergence comes in and equality comes + + + align:start position:0% +Divergence comes in and equality comes +in a more General + + align:start position:0% +in a more General + + + align:start position:0% +in a more General +would you like to see a more General lus + + align:start position:0% +would you like to see a more General lus + + + align:start position:0% +would you like to see a more General lus +equation well a more General Pon + + align:start position:0% +equation well a more General Pon + + + align:start position:0% +equation well a more General Pon +equation so let me underneath La let me + + align:start position:0% + + + + align:start position:0% + +write you got the pronunciation the + + align:start position:0% +write you got the pronunciation the + + + align:start position:0% +write you got the pronunciation the +brilliant French pronunciation there of + + align:start position:0% +brilliant French pronunciation there of + + + align:start position:0% +brilliant French pronunciation there of +P that was my best I can't improve on + + align:start position:0% +P that was my best I can't improve on + + + align:start position:0% +P that was my best I can't improve on +that one okay so it comes in when + + align:start position:0% +that one okay so it comes in when + + + align:start position:0% +that one okay so it comes in when +there's a right hand side so the normal + + align:start position:0% +there's a right hand side so the normal + + + align:start position:0% +there's a right hand side so the normal +P equation is second der with respect to + + align:start position:0% +P equation is second der with respect to + + + align:start position:0% +P equation is second der with respect to +X second deriva with respect to Y well + + align:start position:0% +X second deriva with respect to Y well + + + align:start position:0% +X second deriva with respect to Y well +actually our should should have a minus + + align:start position:0% +actually our should should have a minus + + + align:start position:0% +actually our should should have a minus +there really should be a minus there + + align:start position:0% +there really should be a minus there + + + align:start position:0% +there really should be a minus there +just + + align:start position:0% +just + + + align:start position:0% +just +to you remember why the minus is there + + align:start position:0% +to you remember why the minus is there + + + align:start position:0% +to you remember why the minus is there +the minus is there to make the whole + + align:start position:0% +the minus is there to make the whole + + + align:start position:0% +the minus is there to make the whole +thing positive I mean right that sounds + + align:start position:0% +thing positive I mean right that sounds + + + align:start position:0% +thing positive I mean right that sounds +crazy that the minus makes it positive + + align:start position:0% +crazy that the minus makes it positive + + + align:start position:0% +crazy that the minus makes it positive +but these second derivatives are + + align:start position:0% +but these second derivatives are + + + align:start position:0% +but these second derivatives are +negative definite as always and the + + align:start position:0% +negative definite as always and the + + + align:start position:0% +negative definite as always and the +minus makes some positive definite so I + + align:start position:0% +minus makes some positive definite so I + + + align:start position:0% +minus makes some positive definite so I +don't remember whether maybe I maybe I + + align:start position:0% +don't remember whether maybe I maybe I + + + align:start position:0% +don't remember whether maybe I maybe I +often include the minus over here equal + + align:start position:0% +often include the minus over here equal + + + align:start position:0% +often include the minus over here equal +f of x and y so there's a source plus + + align:start position:0% +f of x and y so there's a source plus + + + align:start position:0% +f of x and y so there's a source plus +all has a source term llas + + align:start position:0% +all has a source term llas + + + align:start position:0% +all has a source term llas +doesn't and and just while I'm talking + + align:start position:0% +doesn't and and just while I'm talking + + + align:start position:0% +doesn't and and just while I'm talking +about this framework if there was a c of + + align:start position:0% +about this framework if there was a c of + + + align:start position:0% +about this framework if there was a c of +X and Y so this would be uh or I'll put + + align:start position:0% +X and Y so this would be uh or I'll put + + + align:start position:0% +X and Y so this would be uh or I'll put +or uh the more General one would be the + + align:start position:0% +or uh the more General one would be the + + + align:start position:0% +or uh the more General one would be the +X derivative because I'm taking the + + align:start position:0% +X derivative because I'm taking the + + + align:start position:0% +X derivative because I'm taking the +Divergence of a c of X and y du U + + align:start position:0% +Divergence of a c of X and y du U + + + align:start position:0% +Divergence of a c of X and y du U +DX and the Y derivative of a c so you + + align:start position:0% +DX and the Y derivative of a c so you + + + align:start position:0% +DX and the Y derivative of a c so you +see the difference I'm now allowing a + + align:start position:0% +see the difference I'm now allowing a + + + align:start position:0% +see the difference I'm now allowing a +some variable + + align:start position:0% +some variable + + + align:start position:0% +some variable +conductivity + + align:start position:0% +conductivity + + + align:start position:0% +conductivity +variable uh whatever this variable + + align:start position:0% +variable uh whatever this variable + + + align:start position:0% +variable uh whatever this variable +material + + align:start position:0% +material + + + align:start position:0% +material +duy equals F again so that would be the + + align:start position:0% +duy equals F again so that would be the + + + align:start position:0% +duy equals F again so that would be the +more General one I don't think we plan + + align:start position:0% +more General one I don't think we plan + + + align:start position:0% +more General one I don't think we plan +to study that in well that's not the + + align:start position:0% +to study that in well that's not the + + + align:start position:0% +to study that in well that's not the +most General I could get have more and + + align:start position:0% +most General I could get have more and + + + align:start position:0% +most General I could get have more and +more things there but that's that shows + + align:start position:0% +more things there but that's that shows + + + align:start position:0% +more things there but that's that shows +you a variable + + align:start position:0% +you a variable + + + align:start position:0% +you a variable +material yeah that material is variable + + align:start position:0% +material yeah that material is variable + + + align:start position:0% +material yeah that material is variable +I would use the word what what word + + align:start position:0% +I would use the word what what word + + + align:start position:0% +I would use the word what what word +would I use it doesn't depend on the + + align:start position:0% +would I use it doesn't depend on the + + + align:start position:0% +would I use it doesn't depend on the +direction I I'm using the same C of XY y + + align:start position:0% +direction I I'm using the same C of XY y + + + align:start position:0% +direction I I'm using the same C of XY y +in the X Direction and the y direction + + align:start position:0% +in the X Direction and the y direction + + + align:start position:0% +in the X Direction and the y direction +therefore in all directions and I didn't + + align:start position:0% +therefore in all directions and I didn't + + + align:start position:0% +therefore in all directions and I didn't +come prepared with that word what's the + + align:start position:0% +come prepared with that word what's the + + + align:start position:0% +come prepared with that word what's the +word for when it doesn't depend on the + + align:start position:0% +word for when it doesn't depend on the + + + align:start position:0% +word for when it doesn't depend on the +direction I isotropic thanks isotropic + + align:start position:0% +direction I isotropic thanks isotropic + + + align:start position:0% +direction I isotropic thanks isotropic +so that's isotropic right so that's + + align:start position:0% +so that's isotropic right so that's + + + align:start position:0% +so that's isotropic right so that's +really our framework + + align:start position:0% +really our framework + + + align:start position:0% +really our framework +there at least for isotropic materials + + align:start position:0% +there at least for isotropic materials + + + align:start position:0% +there at least for isotropic materials +and then we could have more General with + + align:start position:0% +and then we could have more General with + + + align:start position:0% +and then we could have more General with +an isotropic materials that would be fun + + align:start position:0% +an isotropic materials that would be fun + + + align:start position:0% +an isotropic materials that would be fun +too all of those things are fun but + + align:start position:0% +too all of those things are fun but + + + align:start position:0% +too all of those things are fun but +lasses equation is the most fun of all + + align:start position:0% +lasses equation is the most fun of all + + + align:start position:0% +lasses equation is the most fun of all +so let me take F to be zero C to be one + + align:start position:0% +so let me take F to be zero C to be one + + + align:start position:0% +so let me take F to be zero C to be one +get back up to lass's equation and + + align:start position:0% +get back up to lass's equation and + + + align:start position:0% +get back up to lass's equation and +uh begin to make + + align:start position:0% +uh begin to make + + + align:start position:0% +uh begin to make +connections begin to make connections + + align:start position:0% +connections begin to make connections + + + align:start position:0% +connections begin to make connections +okay the beautiful connection the + + align:start position:0% +okay the beautiful connection the + + + align:start position:0% +okay the beautiful connection the +beautiful connection is the one right + + align:start position:0% +beautiful connection is the one right + + + align:start position:0% +beautiful connection is the one right +here when V and U are the same when V + + align:start position:0% +here when V and U are the same when V + + + align:start position:0% +here when V and U are the same when V +and W are the same then I just read off + + align:start position:0% +and W are the same then I just read off + + + align:start position:0% +and W are the same then I just read off +if V is the same as W then how is the + + align:start position:0% +if V is the same as W then how is the + + + align:start position:0% +if V is the same as W then how is the +potential function which is on the left + + align:start position:0% +potential function which is on the left + + + align:start position:0% +potential function which is on the left +side connected to the stream function + + align:start position:0% +side connected to the stream function + + + align:start position:0% +side connected to the stream function +which is coming from anytime div w is z + + align:start position:0% +which is coming from anytime div w is z + + + align:start position:0% +which is coming from anytime div w is z +I've got a stream function in 2D here + + align:start position:0% +I've got a stream function in 2D here + + + align:start position:0% +I've got a stream function in 2D here +the connection is just those two match + + align:start position:0% +the connection is just those two match + + + align:start position:0% +the connection is just those two match +DX is the same as DS + + align:start position:0% +DX is the same as DS + + + align:start position:0% +DX is the same as DS +Dy and + + align:start position:0% +Dy and + + + align:start position:0% +Dy and +dudy is the same as minus dsdx you see + + align:start position:0% +dudy is the same as minus dsdx you see + + + align:start position:0% +dudy is the same as minus dsdx you see +what the two sides of our world are + + align:start position:0% +what the two sides of our world are + + + align:start position:0% +what the two sides of our world are +coming together this is we're dealing + + align:start position:0% +coming together this is we're dealing + + + align:start position:0% +coming together this is we're dealing +with flows that are + + align:start position:0% +with flows that are + + + align:start position:0% +with flows that are +both gradient flows they come from a + + align:start position:0% +both gradient flows they come from a + + + align:start position:0% +both gradient flows they come from a +potential + + align:start position:0% +potential + + + align:start position:0% +potential +potential and they're also there so I + + align:start position:0% +potential and they're also there so I + + + align:start position:0% +potential and they're also there so I +you could often say potential flows I + + align:start position:0% +you could often say potential flows I + + + align:start position:0% +you could often say potential flows I +see the word ideal flows coming in these + + align:start position:0% +see the word ideal flows coming in these + + + align:start position:0% +see the word ideal flows coming in these +are very special flows you know + + align:start position:0% +are very special flows you know + + + align:start position:0% +are very special flows you know +so uh Arrow couldn't work entirely with + + align:start position:0% +so uh Arrow couldn't work entirely with + + + align:start position:0% +so uh Arrow couldn't work entirely with +these flows of course these are such + + align:start position:0% +these flows of course these are such + + + align:start position:0% +these flows of course these are such +ideal flows that you know proper + + align:start position:0% +ideal flows that you know proper + + + align:start position:0% +ideal flows that you know proper +aerodynamics you got shocks you've got + + align:start position:0% +aerodynamics you got shocks you've got + + + align:start position:0% +aerodynamics you got shocks you've got +all sorts of stuff going on but in a + + align:start position:0% +all sorts of stuff going on but in a + + + align:start position:0% +all sorts of stuff going on but in a +region of where everything's beautiful + + align:start position:0% +region of where everything's beautiful + + + align:start position:0% +region of where everything's beautiful +then + + align:start position:0% +then + + + align:start position:0% +then +you get back to this set total steady + + align:start position:0% +you get back to this set total steady + + + align:start position:0% +you get back to this set total steady +state steady flow steady potential flow + + align:start position:0% +state steady flow steady potential flow + + + align:start position:0% +state steady flow steady potential flow +we've got those + + align:start position:0% +we've got those + + + align:start position:0% +we've got those +equations that connect you on one side + + align:start position:0% +equations that connect you on one side + + + align:start position:0% +equations that connect you on one side +with the with the Divergence business + + align:start position:0% +with the with the Divergence business + + + align:start position:0% +with the with the Divergence business +the stream function on the other side so + + align:start position:0% +the stream function on the other side so + + + align:start position:0% +the stream function on the other side so +I just want to so I want to focus on + + align:start position:0% +I just want to so I want to focus on + + + align:start position:0% +I just want to so I want to focus on +these actually I mean so the heart of + + align:start position:0% +these actually I mean so the heart of + + + align:start position:0% +these actually I mean so the heart of +ll's equation is in there yeah okay uh + + align:start position:0% +ll's equation is in there yeah okay uh + + + align:start position:0% +ll's equation is in there yeah okay uh +first do you know the names of those + + align:start position:0% +first do you know the names of those + + + align:start position:0% +first do you know the names of those +those two two guys I shouldn't call them + + align:start position:0% +those two two guys I shouldn't call them + + + align:start position:0% +those two two guys I shouldn't call them +guys they're the greatest mathematicians + + align:start position:0% +guys they're the greatest mathematicians + + + align:start position:0% +guys they're the greatest mathematicians +ever or maybe after gals uh do you know + + align:start position:0% +ever or maybe after gals uh do you know + + + align:start position:0% +ever or maybe after gals uh do you know +whose names are associated with with + + align:start position:0% +whose names are associated with with + + + align:start position:0% +whose names are associated with with +these those two + + align:start position:0% +these those two + + + align:start position:0% +these those two +equations well lrange was great I'm not + + align:start position:0% +equations well lrange was great I'm not + + + align:start position:0% +equations well lrange was great I'm not +saying anything about lrange but he + + align:start position:0% +saying anything about lrange but he + + + align:start position:0% +saying anything about lrange but he +didn't do this so two one French and one + + align:start position:0% +didn't do this so two one French and one + + + align:start position:0% +didn't do this so two one French and one +German uh so the French guy's name is is + + align:start position:0% +German uh so the French guy's name is is + + + align:start position:0% +German uh so the French guy's name is is +Koshi + + align:start position:0% +Koshi + + + align:start position:0% +Koshi +and the German is so these are the Koshi + + align:start position:0% +and the German is so these are the Koshi + + + align:start position:0% +and the German is so these are the Koshi +and the German is really fantastic guy + + align:start position:0% +and the German is really fantastic guy + + + align:start position:0% +and the German is really fantastic guy +uh anybody know his + + align:start position:0% +uh anybody know his + + + align:start position:0% +uh anybody know his +name Koshi reman yeah the other name is + + align:start position:0% +name Koshi reman yeah the other name is + + + align:start position:0% +name Koshi reman yeah the other name is +reman Koshi reman + + align:start position:0% +reman Koshi reman + + + align:start position:0% +reman Koshi reman +equations that connect the two pieces U + + align:start position:0% +equations that connect the two pieces U + + + align:start position:0% +equations that connect the two pieces U +and S and and they're the subject of an + + align:start position:0% +and S and and they're the subject of an + + + align:start position:0% +and S and and they're the subject of an +enormous theory that we'll just touch on + + align:start position:0% +enormous theory that we'll just touch on + + + align:start position:0% +enormous theory that we'll just touch on +here okay and we'll see them Gra ially + + align:start position:0% +here okay and we'll see them Gra ially + + + align:start position:0% +here okay and we'll see them Gra ially +and we'll find Solutions yeah so so this + + align:start position:0% +and we'll find Solutions yeah so so this + + + align:start position:0% +and we'll find Solutions yeah so so this +is one way to pose our problem notice + + align:start position:0% +is one way to pose our problem notice + + + align:start position:0% +is one way to pose our problem notice +something here so does so I think that + + align:start position:0% +something here so does so I think that + + + align:start position:0% +something here so does so I think that +if we have these equations the solution + + align:start position:0% +if we have these equations the solution + + + align:start position:0% +if we have these equations the solution +you should satisfy the pla's equation + + align:start position:0% +you should satisfy the pla's equation + + + align:start position:0% +you should satisfy the pla's equation +because that'll this equality will take + + align:start position:0% +because that'll this equality will take + + + align:start position:0% +because that'll this equality will take +us around the loop uh so do I do you see + + align:start position:0% +us around the loop uh so do I do you see + + + align:start position:0% +us around the loop uh so do I do you see +that if if I could solve these two + + align:start position:0% +that if if I could solve these two + + + align:start position:0% +that if if I could solve these two +here's the point I'm going to get ll's + + align:start position:0% +here's the point I'm going to get ll's + + + align:start position:0% +here's the point I'm going to get ll's +equation solved by you + + align:start position:0% +equation solved by you + + + align:start position:0% +equation solved by you +lass's equation will also be solved by S + + align:start position:0% +lass's equation will also be solved by S + + + align:start position:0% +lass's equation will also be solved by S +the stream function so what's going to + + align:start position:0% +the stream function so what's going to + + + align:start position:0% +the stream function so what's going to +happen is I get two solutions a pair of + + align:start position:0% +happen is I get two solutions a pair of + + + align:start position:0% +happen is I get two solutions a pair of +solutions lasses equation the solutions + + align:start position:0% +solutions lasses equation the solutions + + + align:start position:0% +solutions lasses equation the solutions +to that come in pairs U and S so to so + + align:start position:0% +to that come in pairs U and S so to so + + + align:start position:0% +to that come in pairs U and S so to so +we get them two at a time and they're + + align:start position:0% +we get them two at a time and they're + + + align:start position:0% +we get them two at a time and they're +connected in this remarkable way so why + + align:start position:0% +connected in this remarkable way so why + + + align:start position:0% +connected in this remarkable way so why +let's see can you see that you will + + align:start position:0% +let's see can you see that you will + + + align:start position:0% +let's see can you see that you will +satisfy that this is the key to + + align:start position:0% +satisfy that this is the key to + + + align:start position:0% +satisfy that this is the key to +everything does you s satisfy the pl's + + align:start position:0% +everything does you s satisfy the pl's + + + align:start position:0% +everything does you s satisfy the pl's +equation sure I take the X derivative of + + align:start position:0% +equation sure I take the X derivative of + + + align:start position:0% +equation sure I take the X derivative of +that and I add to the Y derivative of + + align:start position:0% +that and I add to the Y derivative of + + + align:start position:0% +that and I add to the Y derivative of +that do you see it works the X + + align:start position:0% +that do you see it works the X + + + align:start position:0% +that do you see it works the X +derivative of this plus the Y derivative + + align:start position:0% +derivative of this plus the Y derivative + + + align:start position:0% +derivative of this plus the Y derivative +of this is exactly the cancellation of + + align:start position:0% +of this is exactly the cancellation of + + + align:start position:0% +of this is exactly the cancellation of +the cross that I wanted so I do these I + + align:start position:0% +the cross that I wanted so I do these I + + + align:start position:0% +the cross that I wanted so I do these I +I combine those into the + + align:start position:0% + + + + align:start position:0% + +plus so I + + align:start position:0% +plus so I + + + align:start position:0% +plus so I +just say that go through that verbally + + align:start position:0% +just say that go through that verbally + + + align:start position:0% +just say that go through that verbally +again I take the X derivative of this + + align:start position:0% +again I take the X derivative of this + + + align:start position:0% +again I take the X derivative of this +which which gives me the cross + + align:start position:0% +which which gives me the cross + + + align:start position:0% +which which gives me the cross +derivative of s this ask me to take the + + align:start position:0% +derivative of s this ask me to take the + + + align:start position:0% +derivative of s this ask me to take the +Y derivative so I get the cross + + align:start position:0% +Y derivative so I get the cross + + + align:start position:0% +Y derivative so I get the cross +derivative again with the minus sign + + align:start position:0% +derivative again with the minus sign + + + align:start position:0% +derivative again with the minus sign +they add to zero I I just want to point + + align:start position:0% +they add to zero I I just want to point + + + align:start position:0% +they add to zero I I just want to point +out that + + align:start position:0% + + + + align:start position:0% + +also s satisfies Theos equation can can + + align:start position:0% +also s satisfies Theos equation can can + + + align:start position:0% +also s satisfies Theos equation can can +we do that + + align:start position:0% + + + + align:start position:0% + +one I I claim that also the stream + + align:start position:0% +one I I claim that also the stream + + + align:start position:0% +one I I claim that also the stream +function solves L plastus equation + + align:start position:0% +function solves L plastus equation + + + align:start position:0% +function solves L plastus equation +because we want the X derivative of dsdx + + align:start position:0% +because we want the X derivative of dsdx + + + align:start position:0% +because we want the X derivative of dsdx +so DS DX is minus this do you see what's + + align:start position:0% +so DS DX is minus this do you see what's + + + align:start position:0% +so DS DX is minus this do you see what's +happening when I take the X derivative + + align:start position:0% +happening when I take the X derivative + + + align:start position:0% +happening when I take the X derivative +of DS DX I get minus the cross + + align:start position:0% +of DS DX I get minus the cross + + + align:start position:0% +of DS DX I get minus the cross +derivative of + + align:start position:0% +derivative of + + + align:start position:0% +derivative of +U for the this guy it's the Y derivative + + align:start position:0% +U for the this guy it's the Y derivative + + + align:start position:0% +U for the this guy it's the Y derivative +of this which is plus the cross + + align:start position:0% +of this which is plus the cross + + + align:start position:0% +of this which is plus the cross +derivative of U they cancel so yeah U + + align:start position:0% +derivative of U they cancel so yeah U + + + align:start position:0% +derivative of U they cancel so yeah U +and S are just together oh Let's find + + align:start position:0% +and S are just together oh Let's find + + + align:start position:0% +and S are just together oh Let's find +let's let's find some solutions they're + + align:start position:0% +let's let's find some solutions they're + + + align:start position:0% +let's let's find some solutions they're +they're great to find yeah and then draw + + align:start position:0% +they're great to find yeah and then draw + + + align:start position:0% +they're great to find yeah and then draw +them okay can I find some solutions to L + + align:start position:0% +them okay can I find some solutions to L + + + align:start position:0% +them okay can I find some solutions to L +pla's equation uh and I'm going to find + + align:start position:0% +pla's equation uh and I'm going to find + + + align:start position:0% +pla's equation uh and I'm going to find +them in pairs so I'm going to have a + + align:start position:0% +them in pairs so I'm going to have a + + + align:start position:0% +them in pairs so I'm going to have a +list of + + align:start position:0% +list of + + + align:start position:0% +list of +U's and their corresponding + + align:start position:0% + + + + align:start position:0% + +s's + + align:start position:0% +s's + + + align:start position:0% +s's +okay that's these are solutions to lass + + align:start position:0% +okay that's these are solutions to lass + + + align:start position:0% +okay that's these are solutions to lass +these are solve lasses equation so we've + + align:start position:0% +these are solve lasses equation so we've + + + align:start position:0% +these are solve lasses equation so we've +got lass's equation in our minds + + align:start position:0% +got lass's equation in our minds + + + align:start position:0% +got lass's equation in our minds +actually they they furthermore they + + align:start position:0% +actually they they furthermore they + + + align:start position:0% +actually they they furthermore they +solve remon because they're going to be + + align:start position:0% +solve remon because they're going to be + + + align:start position:0% +solve remon because they're going to be +connected by our Koshi remon equations + + align:start position:0% +connected by our Koshi remon equations + + + align:start position:0% +connected by our Koshi remon equations +so so solve LL and Koshi + + align:start position:0% +so so solve LL and Koshi + + + align:start position:0% +so so solve LL and Koshi +Rema okay suppose I take U of x yal + + align:start position:0% +Rema okay suppose I take U of x yal + + + align:start position:0% +Rema okay suppose I take U of x yal +x i I'm going to start with an easy + + align:start position:0% +x i I'm going to start with an easy + + + align:start position:0% +x i I'm going to start with an easy +solution you that certainly solves Lassa + + align:start position:0% +solution you that certainly solves Lassa + + + align:start position:0% +solution you that certainly solves Lassa +equation you got Lassa equation in mind + + align:start position:0% +equation you got Lassa equation in mind + + + align:start position:0% +equation you got Lassa equation in mind +let me let me write it up here again uxx + + align:start position:0% +let me let me write it up here again uxx + + + align:start position:0% +let me let me write it up here again uxx +plus u y yal z + + align:start position:0% +plus u y yal z + + + align:start position:0% +plus u y yal z +I I take the chance to write it again to + + align:start position:0% +I I take the chance to write it again to + + + align:start position:0% +I I take the chance to write it again to +use to do it in this little bit shorter + + align:start position:0% +use to do it in this little bit shorter + + + align:start position:0% +use to do it in this little bit shorter +notation just subscripts instead of + + align:start position:0% +notation just subscripts instead of + + + align:start position:0% +notation just subscripts instead of +partials and also s XX plus s y yal z + + align:start position:0% +partials and also s XX plus s y yal z + + + align:start position:0% +partials and also s XX plus s y yal z +but most of + + align:start position:0% +but most of + + + align:start position:0% +but most of +all the the koshian that connects the + + align:start position:0% +all the the koshian that connects the + + + align:start position:0% +all the the koshian that connects the +two well does you equal x solve thees + + align:start position:0% +two well does you equal x solve thees + + + align:start position:0% +two well does you equal x solve thees +equation of course it does the second X + + align:start position:0% +equation of course it does the second X + + + align:start position:0% +equation of course it does the second X +derivative if the function is X is zero + + align:start position:0% +derivative if the function is X is zero + + + align:start position:0% +derivative if the function is X is zero +and the second y derivative is very very + + align:start position:0% +and the second y derivative is very very + + + align:start position:0% +and the second y derivative is very very +zero okay so what's s what's the s that + + align:start position:0% +zero okay so what's s what's the s that + + + align:start position:0% +zero okay so what's s what's the s that +goes with it it'll be simple too it's + + align:start position:0% +goes with it it'll be simple too it's + + + align:start position:0% +goes with it it'll be simple too it's +supposed to so the S so U is X right I'm + + align:start position:0% +supposed to so the S so U is X right I'm + + + align:start position:0% +supposed to so the S so U is X right I'm +taking starting with this x well so du + + align:start position:0% +taking starting with this x well so du + + + align:start position:0% +taking starting with this x well so du +DX is one so what do you figure s + + align:start position:0% +DX is one so what do you figure s + + + align:start position:0% +DX is one so what do you figure s +is if if if du DX see U is just X itself + + align:start position:0% +is if if if du DX see U is just X itself + + + align:start position:0% +is if if if du DX see U is just X itself +so DX is only a one that derivative was + + align:start position:0% +so DX is only a one that derivative was + + + align:start position:0% +so DX is only a one that derivative was +easy what's then DS Dy is supposed to be + + align:start position:0% +easy what's then DS Dy is supposed to be + + + align:start position:0% +easy what's then DS Dy is supposed to be +one and d s DX is supposed to be zero I + + align:start position:0% +one and d s DX is supposed to be zero I + + + align:start position:0% +one and d s DX is supposed to be zero I +guess do you see what s + + align:start position:0% +guess do you see what s + + + align:start position:0% +guess do you see what s +is y s is y s is y of course that solves + + align:start position:0% +is y s is y s is y of course that solves + + + align:start position:0% +is y s is y s is y of course that solves +lus equation to and it solves Koshi Rema + + align:start position:0% +lus equation to and it solves Koshi Rema + + + align:start position:0% +lus equation to and it solves Koshi Rema +and the X derivative of this is the Y + + align:start position:0% +and the X derivative of this is the Y + + + align:start position:0% +and the X derivative of this is the Y +derivative of that 1 equal 1 and the Y + + align:start position:0% +derivative of that 1 equal 1 and the Y + + + align:start position:0% +derivative of that 1 equal 1 and the Y +derivative of that is minus the X + + align:start position:0% +derivative of that is minus the X + + + align:start position:0% +derivative of that is minus the X +derivative of that 0 equals 0 okay so + + align:start position:0% +derivative of that 0 equals 0 okay so + + + align:start position:0% +derivative of that 0 equals 0 okay so +that's an easy one let me I'm going to + + align:start position:0% +that's an easy one let me I'm going to + + + align:start position:0% +that's an easy one let me I'm going to +go up a level I want to take a second + + align:start position:0% +go up a level I want to take a second + + + align:start position:0% +go up a level I want to take a second +degree so my next guy in the list will + + align:start position:0% +degree so my next guy in the list will + + + align:start position:0% +degree so my next guy in the list will +be a pair it's a list of pairs will be + + align:start position:0% +be a pair it's a list of pairs will be + + + align:start position:0% +be a pair it's a list of pairs will be +x^2 minus + + align:start position:0% + + + + align:start position:0% + +y^2 first of all it better not be on + + align:start position:0% +y^2 first of all it better not be on + + + align:start position:0% +y^2 first of all it better not be on +that list unless it solves Theo's + + align:start position:0% +that list unless it solves Theo's + + + align:start position:0% +that list unless it solves Theo's +equation and then if it is we'll find an + + align:start position:0% +equation and then if it is we'll find an + + + align:start position:0% +equation and then if it is we'll find an +S so what's the plug it in mentally can + + align:start position:0% +S so what's the plug it in mentally can + + + align:start position:0% +S so what's the plug it in mentally can +you plug this into the plaza equation + + align:start position:0% +you plug this into the plaza equation + + + align:start position:0% +you plug this into the plaza equation +what's the second X derivative of this + + align:start position:0% +what's the second X derivative of this + + + align:start position:0% +what's the second X derivative of this +function + + align:start position:0% +function + + + align:start position:0% +function +two right x x brings down a two what's + + align:start position:0% +two right x x brings down a two what's + + + align:start position:0% +two right x x brings down a two what's +the second y + + align:start position:0% +the second y + + + align:start position:0% +the second y +derivative the minus two from this term + + align:start position:0% +derivative the minus two from this term + + + align:start position:0% +derivative the minus two from this term +and then put them into the pluses + + align:start position:0% +and then put them into the pluses + + + align:start position:0% +and then put them into the pluses +equation 2 minus 2 correct zero all + + align:start position:0% +equation 2 minus 2 correct zero all + + + align:start position:0% +equation 2 minus 2 correct zero all +right now I'm looking for the s that + + align:start position:0% +right now I'm looking for the s that + + + align:start position:0% +right now I'm looking for the s that +goes with it the other one in the pair + + align:start position:0% +goes with it the other one in the pair + + + align:start position:0% +goes with it the other one in the pair +okay so what what maybe I better think + + align:start position:0% +okay so what what maybe I better think + + + align:start position:0% +okay so what what maybe I better think +through what so this is supposed to give + + align:start position:0% +through what so this is supposed to give + + + align:start position:0% +through what so this is supposed to give +me the S du DX so so let me I'm copying + + align:start position:0% +me the S du DX so so let me I'm copying + + + align:start position:0% +me the S du DX so so let me I'm copying +the let me + + align:start position:0% +the let me + + + align:start position:0% +the let me +copy Koshi Rema here so we can just + + align:start position:0% +copy Koshi Rema here so we can just + + + align:start position:0% +copy Koshi Rema here so we can just +focus entirely on that board so Dux this + + align:start position:0% +focus entirely on that board so Dux this + + + align:start position:0% +focus entirely on that board so Dux this +is 2x in my + + align:start position:0% +is 2x in my + + + align:start position:0% +is 2x in my +example du Dy is minus + + align:start position:0% +example du Dy is minus + + + align:start position:0% +example du Dy is minus +2y so what am I learning DS Dy should be + + align:start position:0% +2y so what am I learning DS Dy should be + + + align:start position:0% +2y so what am I learning DS Dy should be +2 X DS DX should be 2 y because I have + + align:start position:0% +2 X DS DX should be 2 y because I have + + + align:start position:0% +2 X DS DX should be 2 y because I have +minus signs both there what's s do you + + align:start position:0% +minus signs both there what's s do you + + + align:start position:0% +minus signs both there what's s do you +see + + align:start position:0% +see + + + align:start position:0% +see +s the the Y derivative is 2x the X + + align:start position:0% +s the the Y derivative is 2x the X + + + align:start position:0% +s the the Y derivative is 2x the X +derivative is 2 Y and that stream + + align:start position:0% +derivative is 2 Y and that stream + + + align:start position:0% +derivative is 2 Y and that stream +function + + align:start position:0% +function + + + align:start position:0% +function +is + + align:start position:0% +is + + + align:start position:0% +is +2 X Y right + + align:start position:0% +2 X Y right + + + align:start position:0% +2 X Y right +2xy because the X derivative of this is + + align:start position:0% +2xy because the X derivative of this is + + + align:start position:0% +2xy because the X derivative of this is +2 y and the Y derivative of this is 2X + + align:start position:0% +2 y and the Y derivative of this is 2X + + + align:start position:0% +2 y and the Y derivative of this is 2X +and we've saw we saw 2x y last time also + + align:start position:0% +and we've saw we saw 2x y last time also + + + align:start position:0% +and we've saw we saw 2x y last time also +and of course it solves the pl's + + align:start position:0% +and of course it solves the pl's + + + align:start position:0% +and of course it solves the pl's +equation + + align:start position:0% +equation + + + align:start position:0% +equation +easily plug that in the second + + align:start position:0% +easily plug that in the second + + + align:start position:0% +easily plug that in the second +derivative is zero the second X + + align:start position:0% +derivative is zero the second X + + + align:start position:0% +derivative is zero the second X +derivative is zero like y derivative is + + align:start position:0% +derivative is zero like y derivative is + + + align:start position:0% +derivative is zero like y derivative is +zero everything so that's a + + align:start position:0% +zero everything so that's a + + + align:start position:0% +zero everything so that's a +pair this is this is a nice + + align:start position:0% +pair this is this is a nice + + + align:start position:0% +pair this is this is a nice +pair uh do you want to shoot for third + + align:start position:0% +pair uh do you want to shoot for third + + + align:start position:0% +pair uh do you want to shoot for third +degree + + align:start position:0% +degree + + + align:start position:0% +degree +we could maybe figure out third degree + + align:start position:0% +we could maybe figure out third degree + + + align:start position:0% +we could maybe figure out third degree +just by jiggling it after that we're + + align:start position:0% +just by jiggling it after that we're + + + align:start position:0% +just by jiggling it after that we're +going to need an idea yeah to get up to + + align:start position:0% +going to need an idea yeah to get up to + + + align:start position:0% +going to need an idea yeah to get up to +fourth degree let me let me try third + + align:start position:0% +fourth degree let me let me try third + + + align:start position:0% +fourth degree let me let me try third +degree cubics now so I'm looking first I + + align:start position:0% +degree cubics now so I'm looking first I + + + align:start position:0% +degree cubics now so I'm looking first I +just want to get somebody here so it's + + align:start position:0% +just want to get somebody here so it's + + + align:start position:0% +just want to get somebody here so it's +some X + + align:start position:0% +some X + + + align:start position:0% +some X +cub and then I'm going to need some more + + align:start position:0% +cub and then I'm going to need some more + + + align:start position:0% +cub and then I'm going to need some more +stuff because X Cub by itself certainly + + align:start position:0% +stuff because X Cub by itself certainly + + + align:start position:0% +stuff because X Cub by itself certainly +won't + + align:start position:0% +won't + + + align:start position:0% +won't +work I'm I need something more and I + + align:start position:0% +work I'm I need something more and I + + + align:start position:0% +work I'm I need something more and I +want to plug it into lasses equation and + + align:start position:0% +want to plug it into lasses equation and + + + align:start position:0% +want to plug it into lasses equation and +figure out what should I what should it + + align:start position:0% +figure out what should I what should it + + + align:start position:0% +figure out what should I what should it +be okay so what when I plug this into + + align:start position:0% +be okay so what when I plug this into + + + align:start position:0% +be okay so what when I plug this into +lasses equation what do I get so let me + + align:start position:0% +lasses equation what do I get so let me + + + align:start position:0% +lasses equation what do I get so let me +here let me do ll's equation over here + + align:start position:0% +here let me do ll's equation over here + + + align:start position:0% +here let me do ll's equation over here +for the for the to try to get the U of + + align:start position:0% +for the for the to try to get the U of + + + align:start position:0% +for the for the to try to get the U of +degree + + align:start position:0% + + + + align:start position:0% + +3 so what's uxx so + + align:start position:0% +3 so what's uxx so + + + align:start position:0% +3 so what's uxx so +far 6X right bring down a we get 3x SAR + + align:start position:0% +far 6X right bring down a we get 3x SAR + + + align:start position:0% +far 6X right bring down a we get 3x SAR +then we get 6X so I've got a + + align:start position:0% +then we get 6X so I've got a + + + align:start position:0% +then we get 6X so I've got a +6X and I'm looking for so u y y should + + align:start position:0% +6X and I'm looking for so u y y should + + + align:start position:0% +6X and I'm looking for so u y y should +be minus 6X to cancel that so what do I + + align:start position:0% +be minus 6X to cancel that so what do I + + + align:start position:0% +be minus 6X to cancel that so what do I +want + + align:start position:0% +want + + + align:start position:0% +want +there what do I need I need a minus I'm + + align:start position:0% +there what do I need I need a minus I'm + + + align:start position:0% +there what do I need I need a minus I'm +sure of that uh so the second y + + align:start position:0% +sure of that uh so the second y + + + align:start position:0% +sure of that uh so the second y +derivative should be this 6X deel what + + align:start position:0% +derivative should be this 6X deel what + + + align:start position:0% +derivative should be this 6X deel what +do I want + + align:start position:0% + + + + align:start position:0% + +3x y^2 that sounds good let me write it + + align:start position:0% +3x y^2 that sounds good let me write it + + + align:start position:0% +3x y^2 that sounds good let me write it +down and see if it is good okay the + + align:start position:0% +down and see if it is good okay the + + + align:start position:0% +down and see if it is good okay the +second y derivative yes we'll bring down + + align:start position:0% +second y derivative yes we'll bring down + + + align:start position:0% +second y derivative yes we'll bring down +a two and then the then the Y's will + + align:start position:0% +a two and then the then the Y's will + + + align:start position:0% +a two and then the then the Y's will +disappear and I'll have the minus 6X + + align:start position:0% +disappear and I'll have the minus 6X + + + align:start position:0% +disappear and I'll have the minus 6X +golden okay that's great that's + + align:start position:0% +golden okay that's great that's + + + align:start position:0% +golden okay that's great that's +great is that correct I mean it's great + + align:start position:0% +great is that correct I mean it's great + + + align:start position:0% +great is that correct I mean it's great +but is it right yes yes okay + + align:start position:0% + + + + align:start position:0% + +now you have faith that there's another + + align:start position:0% +now you have faith that there's another + + + align:start position:0% +now you have faith that there's another +one well yeah there is another one I + + align:start position:0% +one well yeah there is another one I + + + align:start position:0% +one well yeah there is another one I +mean right there's Koshi Rema never let + + align:start position:0% +mean right there's Koshi Rema never let + + + align:start position:0% +mean right there's Koshi Rema never let +us down there's a there will be a s + + align:start position:0% +us down there's a there will be a s + + + align:start position:0% +us down there's a there will be a s +that'll go with that that'll solve the + + align:start position:0% +that'll go with that that'll solve the + + + align:start position:0% +that'll go with that that'll solve the +Koshi reman equations and it'll look + + align:start position:0% +Koshi reman equations and it'll look + + + align:start position:0% +Koshi reman equations and it'll look +like it and I + + align:start position:0% + + + + align:start position:0% + +think I think and and sort of I just + + align:start position:0% +think I think and and sort of I just + + + align:start position:0% +think I think and and sort of I just +sort of reverse X and Y to get another + + align:start position:0% +sort of reverse X and Y to get another + + + align:start position:0% +sort of reverse X and Y to get another +one because if I exchange X and Y I'm + + align:start position:0% +one because if I exchange X and Y I'm + + + align:start position:0% +one because if I exchange X and Y I'm +still okay with lass's equation I think + + align:start position:0% +still okay with lass's equation I think + + + align:start position:0% +still okay with lass's equation I think +I I think something like 3 y x^2 - y + + align:start position:0% +I I think something like 3 y x^2 - y + + + align:start position:0% +I I think something like 3 y x^2 - y +cubed you know if that worked then this + + align:start position:0% +cubed you know if that worked then this + + + align:start position:0% +cubed you know if that worked then this +one should work + + align:start position:0% +one should work + + + align:start position:0% +one should work +too because I've just switched X and Y + + align:start position:0% +too because I've just switched X and Y + + + align:start position:0% +too because I've just switched X and Y +and uh I think it it'll work right here + + align:start position:0% +and uh I think it it'll work right here + + + align:start position:0% +and uh I think it it'll work right here +the second X derivative will be 6 Y and + + align:start position:0% +the second X derivative will be 6 Y and + + + align:start position:0% +the second X derivative will be 6 Y and +the second y derivative will be minus 6 + + align:start position:0% +the second y derivative will be minus 6 + + + align:start position:0% +the second y derivative will be minus 6 +Y and that's I think that's good okay so + + align:start position:0% +Y and that's I think that's good okay so + + + align:start position:0% +Y and that's I think that's good okay so +we so we've got + + align:start position:0% +we so we've got + + + align:start position:0% +we so we've got +let's put this list on hold for a moment + + align:start position:0% +let's put this list on hold for a moment + + + align:start position:0% +let's put this list on hold for a moment +something's obviously there's some + + align:start position:0% +something's obviously there's some + + + align:start position:0% +something's obviously there's some +pattern here that we've got to + + align:start position:0% +pattern here that we've got to + + + align:start position:0% +pattern here that we've got to +locate can I put it on hold for a moment + + align:start position:0% +locate can I put it on hold for a moment + + + align:start position:0% +locate can I put it on hold for a moment +and take for example the graph of this + + align:start position:0% +and take for example the graph of this + + + align:start position:0% +and take for example the graph of this +one and I want to draw the pictures + + align:start position:0% +one and I want to draw the pictures + + + align:start position:0% +one and I want to draw the pictures +before I + + align:start position:0% +before I + + + align:start position:0% +before I +get a complete list I want to draw the + + align:start position:0% +get a complete list I want to draw the + + + align:start position:0% +get a complete list I want to draw the +pictures of these functions and what do + + align:start position:0% +pictures of these functions and what do + + + align:start position:0% +pictures of these functions and what do +I mean by pictures I mean uh draw the so + + align:start position:0% +I mean by pictures I mean uh draw the so + + + align:start position:0% +I mean by pictures I mean uh draw the so +now I'm taking the U to be x^2 - y^2 and + + align:start position:0% +now I'm taking the U to be x^2 - y^2 and + + + align:start position:0% +now I'm taking the U to be x^2 - y^2 and +the S to be + + align:start position:0% +the S to be + + + align:start position:0% +the S to be +2xy and I want to draw the those I want + + align:start position:0% +2xy and I want to draw the those I want + + + align:start position:0% +2xy and I want to draw the those I want +to draw the vector field of the + + align:start position:0% +to draw the vector field of the + + + align:start position:0% +to draw the vector field of the +gradients of those guys okay so this is + + align:start position:0% +gradients of those guys okay so this is + + + align:start position:0% +gradients of those guys okay so this is +the U I want to draw the equ this is the + + align:start position:0% +the U I want to draw the equ this is the + + + align:start position:0% +the U I want to draw the equ this is the +potential x^2 minus y^2 so what are the + + align:start position:0% +potential x^2 minus y^2 so what are the + + + align:start position:0% +potential x^2 minus y^2 so what are the +equip potential curves so this is now + + align:start position:0% +equip potential curves so this is now + + + align:start position:0% +equip potential curves so this is now +I'm drawing the flow and to draw the + + align:start position:0% +I'm drawing the flow and to draw the + + + align:start position:0% +I'm drawing the flow and to draw the +flow I draw the curves on which the + + align:start position:0% +flow I draw the curves on which the + + + align:start position:0% +flow I draw the curves on which the +potential is a + + align:start position:0% +potential is a + + + align:start position:0% +potential is a +constant x^2 - y^2 equal constant so + + align:start position:0% +constant x^2 - y^2 equal constant so + + + align:start position:0% +constant x^2 - y^2 equal constant so +what kind of a curve is x^2 - y^2 equal + + align:start position:0% +what kind of a curve is x^2 - y^2 equal + + + align:start position:0% +what kind of a curve is x^2 - y^2 equal +constant it's a hyperbola it's a + + align:start position:0% +constant it's a hyperbola it's a + + + align:start position:0% +constant it's a hyperbola it's a +hyperbola so let me put in so x^2 - y^2 + + align:start position:0% +hyperbola so let me put in so x^2 - y^2 + + + align:start position:0% +hyperbola so let me put in so x^2 - y^2 +equal Let's Take One For example what + + align:start position:0% +equal Let's Take One For example what + + + align:start position:0% +equal Let's Take One For example what +what as as one constant so so x = 1 will + + align:start position:0% +what as as one constant so so x = 1 will + + + align:start position:0% +what as as one constant so so x = 1 will +be on the curve when Y is zero and then + + align:start position:0% +be on the curve when Y is zero and then + + + align:start position:0% +be on the curve when Y is zero and then +what else will be on the curve if x is a + + align:start position:0% +what else will be on the curve if x is a + + + align:start position:0% +what else will be on the curve if x is a +little bigger like two yeah what what's + + align:start position:0% +little bigger like two yeah what what's + + + align:start position:0% +little bigger like two yeah what what's +see if suppose so so here is one Zer + + align:start position:0% +see if suppose so so here is one Zer + + + align:start position:0% +see if suppose so so here is one Zer +that point + + align:start position:0% +that point + + + align:start position:0% +that point +is certainly x^2 - y^2 is one for that + + align:start position:0% +is certainly x^2 - y^2 is one for that + + + align:start position:0% +is certainly x^2 - y^2 is one for that +suppose I go out to xal 2 What should y + + align:start position:0% +suppose I go out to xal 2 What should y + + + align:start position:0% +suppose I go out to xal 2 What should y +be then to make this right to where + + align:start position:0% +be then to make this right to where + + + align:start position:0% +be then to make this right to where +where's the curve going when X is two + + align:start position:0% +where's the curve going when X is two + + + align:start position:0% +where's the curve going when X is two +what what is + + align:start position:0% +what what is + + + align:start position:0% +what what is +y squ < TK of 3 up plus plus or minus so + + align:start position:0% +y squ < TK of 3 up plus plus or minus so + + + align:start position:0% +y squ < TK of 3 up plus plus or minus so +< TK 3 is something like this up or down + + align:start position:0% +< TK 3 is something like this up or down + + + align:start position:0% +< TK 3 is something like this up or down +it's a it's a + + align:start position:0% +it's a it's a + + + align:start position:0% +it's a it's a +curve like + + align:start position:0% +curve like + + + align:start position:0% +curve like +so it's a + + align:start position:0% + + + + align:start position:0% + +hyperbola that's that's and now if I + + align:start position:0% +hyperbola that's that's and now if I + + + align:start position:0% +hyperbola that's that's and now if I +change one change change C to four let's + + align:start position:0% +change one change change C to four let's + + + align:start position:0% +change one change change C to four let's +say then it'll go through two Z and + + align:start position:0% +say then it'll go through two Z and + + + align:start position:0% +say then it'll go through two Z and +it'll go up this + + align:start position:0% +it'll go up this + + + align:start position:0% +it'll go up this +way and if I change X to something very + + align:start position:0% +way and if I change X to something very + + + align:start position:0% +way and if I change X to something very +small uh it'll still oh do you know what + + align:start position:0% +small uh it'll still oh do you know what + + + align:start position:0% +small uh it'll still oh do you know what +the there's a + + align:start position:0% +the there's a + + + align:start position:0% +the there's a +word a Greek word ASM tootes oh yeah + + align:start position:0% +word a Greek word ASM tootes oh yeah + + + align:start position:0% +word a Greek word ASM tootes oh yeah +what do I get if the ASM toote is when + + align:start position:0% +what do I get if the ASM toote is when + + + align:start position:0% +what do I get if the ASM toote is when +this is zero yeah when when that is zero + + align:start position:0% +this is zero yeah when when that is zero + + + align:start position:0% +this is zero yeah when when that is zero +what's what's my curve what what what + + align:start position:0% +what's what's my curve what what what + + + align:start position:0% +what's what's my curve what what what +are X and + + align:start position:0% + + + + align:start position:0% + +Y they'll be the same X will be y or + + align:start position:0% +Y they'll be the same X will be y or + + + align:start position:0% +Y they'll be the same X will be y or +minus y I'll be on that straight line or + + align:start position:0% +minus y I'll be on that straight line or + + + align:start position:0% +minus y I'll be on that straight line or +on this straight line so all the other + + align:start position:0% +on this straight line so all the other + + + align:start position:0% +on this straight line so all the other +all these other hyperbolas are kind of + + align:start position:0% +all these other hyperbolas are kind of + + + align:start position:0% +all these other hyperbolas are kind of +asymptotic whatever the word is uh right + + align:start position:0% +asymptotic whatever the word is uh right + + + align:start position:0% +asymptotic whatever the word is uh right +you see them as a bunch of + + align:start position:0% +you see them as a bunch of + + + align:start position:0% +you see them as a bunch of +hyperbolas uh and + + align:start position:0% +hyperbolas uh and + + + align:start position:0% +hyperbolas uh and +actually more + + align:start position:0% +actually more + + + align:start position:0% +actually more +hyperbolas well yeah + + align:start position:0% +hyperbolas well yeah + + + align:start position:0% +hyperbolas well yeah +think let's see when back when I had a + + align:start position:0% +think let's see when back when I had a + + + align:start position:0% +think let's see when back when I had a +one + + align:start position:0% +one + + + align:start position:0% +one +there I took X and Y to be positive and + + align:start position:0% +there I took X and Y to be positive and + + + align:start position:0% +there I took X and Y to be positive and +I got that + + align:start position:0% +I got that + + + align:start position:0% +I got that +hyperbola but I could have since I'm + + align:start position:0% +hyperbola but I could have since I'm + + + align:start position:0% +hyperbola but I could have since I'm +squaring them there also these + + align:start position:0% +squaring them there also these + + + align:start position:0% +squaring them there also these +hyperbolas are + + align:start position:0% +hyperbolas are + + + align:start position:0% +hyperbolas are +here so the these same guys are are uh + + align:start position:0% +here so the these same guys are are uh + + + align:start position:0% +here so the these same guys are are uh +on that side of the + + align:start position:0% +on that side of the + + + align:start position:0% +on that side of the +picture those are the equip potentials + + align:start position:0% +picture those are the equip potentials + + + align:start position:0% +picture those are the equip potentials +so these are the equip + + align:start position:0% + + + + align:start position:0% + +potentials + + align:start position:0% +potentials + + + align:start position:0% +potentials +okay now + + align:start position:0% + + + + align:start position:0% + +let me draw + + align:start position:0% +let me draw + + + align:start position:0% +let me draw +s so those will be the + + align:start position:0% +s so those will be the + + + align:start position:0% +s so those will be the +equ no I don't want to say equist stream + + align:start position:0% +equ no I don't want to say equist stream + + + align:start position:0% +equ no I don't want to say equist stream +functions that's + + align:start position:0% +functions that's + + + align:start position:0% +functions that's +awkward so now I want to draw s equal + + align:start position:0% +awkward so now I want to draw s equal + + + align:start position:0% +awkward so now I want to draw s equal +constant like one or + + align:start position:0% +constant like one or + + + align:start position:0% +constant like one or +whatever so this was this was I've drawn + + align:start position:0% +whatever so this was this was I've drawn + + + align:start position:0% +whatever so this was this was I've drawn +this with a whole lot of constants and + + align:start position:0% +this with a whole lot of constants and + + + align:start position:0% +this with a whole lot of constants and +now I want to draw the other guys what + + align:start position:0% +now I want to draw the other guys what + + + align:start position:0% +now I want to draw the other guys what +do those curves look + + align:start position:0% +do those curves look + + + align:start position:0% +do those curves look +like and what's their + + align:start position:0% +like and what's their + + + align:start position:0% +like and what's their +name a curve on which the stream + + align:start position:0% +name a curve on which the stream + + + align:start position:0% +name a curve on which the stream +function is a constant is has the nice + + align:start position:0% +function is a constant is has the nice + + + align:start position:0% +function is a constant is has the nice +name stream line so now I'm going to + + align:start position:0% +name stream line so now I'm going to + + + align:start position:0% +name stream line so now I'm going to +draw the + + align:start position:0% +draw the + + + align:start position:0% +draw the +streamlines and what are the + + align:start position:0% + + + + align:start position:0% + +streamlines the streamlines will be the + + align:start position:0% +streamlines the streamlines will be the + + + align:start position:0% +streamlines the streamlines will be the +curves that the actual material flows if + + align:start position:0% +curves that the actual material flows if + + + align:start position:0% +curves that the actual material flows if +you drop a leaf into this flow it will + + align:start position:0% +you drop a leaf into this flow it will + + + align:start position:0% +you drop a leaf into this flow it will +and you watch it it'll flow along a + + align:start position:0% +and you watch it it'll flow along a + + + align:start position:0% +and you watch it it'll flow along a +streamline and we can draw those lines + + align:start position:0% +streamline and we can draw those lines + + + align:start position:0% +streamline and we can draw those lines +so what are those uh 2x y = 1 or the + + align:start position:0% +so what are those uh 2x y = 1 or the + + + align:start position:0% +so what are those uh 2x y = 1 or the +equation Y = 1 over + + align:start position:0% +equation Y = 1 over + + + align:start position:0% +equation Y = 1 over +2x that's also a hyperbola right that's + + align:start position:0% +2x that's also a hyperbola right that's + + + align:start position:0% +2x that's also a hyperbola right that's +also a hyperbola this is a fantastic + + align:start position:0% +also a hyperbola this is a fantastic + + + align:start position:0% +also a hyperbola this is a fantastic +picture + + align:start position:0% +picture + + + align:start position:0% +picture +um in which the we have two sets of + + align:start position:0% +um in which the we have two sets of + + + align:start position:0% +um in which the we have two sets of +hyperbolas it just we're second degree + + align:start position:0% +hyperbolas it just we're second degree + + + align:start position:0% +hyperbolas it just we're second degree +that's why we're getting two hyperbolas + + align:start position:0% +that's why we're getting two hyperbolas + + + align:start position:0% +that's why we're getting two hyperbolas +when I I'm not going to tackle drawing + + align:start position:0% +when I I'm not going to tackle drawing + + + align:start position:0% +when I I'm not going to tackle drawing +matl could do it draw the equip + + align:start position:0% +matl could do it draw the equip + + + align:start position:0% +matl could do it draw the equip +potentials and the streamlines for this + + align:start position:0% +potentials and the streamlines for this + + + align:start position:0% +potentials and the streamlines for this +guy oh let's I'm willing to tackle this + + align:start position:0% +guy oh let's I'm willing to tackle this + + + align:start position:0% +guy oh let's I'm willing to tackle this +one um what are the equip potentials and + + align:start position:0% +one um what are the equip potentials and + + + align:start position:0% +one um what are the equip potentials and +the streamlines for the for the easiest + + align:start position:0% +the streamlines for the for the easiest + + + align:start position:0% +the streamlines for the for the easiest +one in the list + + align:start position:0% +one in the list + + + align:start position:0% +one in the list +there can I just draw that one because + + align:start position:0% +there can I just draw that one because + + + align:start position:0% +there can I just draw that one because +it makes a point very clear that that + + align:start position:0% +it makes a point very clear that that + + + align:start position:0% +it makes a point very clear that that +we'll see when we draw these okay so + + align:start position:0% +we'll see when we draw these okay so + + + align:start position:0% +we'll see when we draw these okay so +what's + + align:start position:0% +what's + + + align:start position:0% +what's +the what's the picture the corresponding + + align:start position:0% +the what's the picture the corresponding + + + align:start position:0% +the what's the picture the corresponding +picture what here's the XY plane again + + align:start position:0% +picture what here's the XY plane again + + + align:start position:0% +picture what here's the XY plane again +what are the equip potentials for this + + align:start position:0% +what are the equip potentials for this + + + align:start position:0% +what are the equip potentials for this +for this + + align:start position:0% +for this + + + align:start position:0% +for this +pair and the + + align:start position:0% +pair and the + + + align:start position:0% +pair and the +streamlines the equip potentials are x + + align:start position:0% +streamlines the equip potentials are x + + + align:start position:0% +streamlines the equip potentials are x +equal constant what are those those are + + align:start position:0% +equal constant what are those those are + + + align:start position:0% +equal constant what are those those are +lines vertical lines so the equip + + align:start position:0% +lines vertical lines so the equip + + + align:start position:0% +lines vertical lines so the equip +potentials are just vertical lines equ + + align:start position:0% +potentials are just vertical lines equ + + + align:start position:0% +potentials are just vertical lines equ +potentials x equal a + + align:start position:0% +potentials x equal a + + + align:start position:0% +potentials x equal a +constant and what are the + + align:start position:0% +constant and what are the + + + align:start position:0% +constant and what are the +streamlines horizontal lines streamlines + + align:start position:0% +streamlines horizontal lines streamlines + + + align:start position:0% +streamlines horizontal lines streamlines +go this way and what's the great point + + align:start position:0% +go this way and what's the great point + + + align:start position:0% +go this way and what's the great point +about these These are the streamlines s + + align:start position:0% +about these These are the streamlines s + + + align:start position:0% +about these These are the streamlines s +equal + + align:start position:0% +equal + + + align:start position:0% +equal +constant and of course what do you + + align:start position:0% +constant and of course what do you + + + align:start position:0% +constant and of course what do you +notice + + align:start position:0% +notice + + + align:start position:0% +notice +here they're + + align:start position:0% +here they're + + + align:start position:0% +here they're +perpendicular the streamlines are + + align:start position:0% +perpendicular the streamlines are + + + align:start position:0% +perpendicular the streamlines are +perpendicular to the equip + + align:start position:0% +perpendicular to the equip + + + align:start position:0% +perpendicular to the equip +potentials and why it's because the you + + align:start position:0% +potentials and why it's because the you + + + align:start position:0% +potentials and why it's because the you +remember we talked about what does the D + + align:start position:0% +remember we talked about what does the D + + + align:start position:0% +remember we talked about what does the D +what does the gradient mean where which + + align:start position:0% +what does the gradient mean where which + + + align:start position:0% +what does the gradient mean where which +way does the gradient point it points + + align:start position:0% +way does the gradient point it points + + + align:start position:0% +way does the gradient point it points +perpendicular to these equip potentials + + align:start position:0% +perpendicular to these equip potentials + + + align:start position:0% +perpendicular to these equip potentials +and in this case there all these equip + + align:start position:0% +and in this case there all these equip + + + align:start position:0% +and in this case there all these equip +potentials are parallel and the perpend + + align:start position:0% +potentials are parallel and the perpend + + + align:start position:0% +potentials are parallel and the perpend +and the perpendicular lines are the + + align:start position:0% +and the perpendicular lines are the + + + align:start position:0% +and the perpendicular lines are the +stream lines and they're all + + align:start position:0% +stream lines and they're all + + + align:start position:0% +stream lines and they're all +parallel now over + + align:start position:0% +parallel now over + + + align:start position:0% +parallel now over +here we haven't got straight lines but + + align:start position:0% +here we haven't got straight lines but + + + align:start position:0% +here we haven't got straight lines but +we still have the beautiful figure the + + align:start position:0% +we still have the beautiful figure the + + + align:start position:0% +we still have the beautiful figure the +if I now now I'm ready to tackle I'll + + align:start position:0% +if I now now I'm ready to tackle I'll + + + align:start position:0% +if I now now I'm ready to tackle I'll +draw these curves they're hyper + + align:start position:0% +draw these curves they're hyper + + + align:start position:0% +draw these curves they're hyper +like y = 1 2x yal if I just make that y + + align:start position:0% +like y = 1 2x yal if I just make that y + + + align:start position:0% +like y = 1 2x yal if I just make that y += 1 2x that's a line that comes down + + align:start position:0% += 1 2x that's a line that comes down + + + align:start position:0% += 1 2x that's a line that comes down +this way let me try to draw + + align:start position:0% +this way let me try to draw + + + align:start position:0% +this way let me try to draw +it I'll do use Dash lines of + + align:start position:0% +it I'll do use Dash lines of + + + align:start position:0% +it I'll do use Dash lines of +course as X gets bigger y gets + + align:start position:0% +course as X gets bigger y gets + + + align:start position:0% +course as X gets bigger y gets +smaller but never you know y never makes + + align:start position:0% +smaller but never you know y never makes + + + align:start position:0% +smaller but never you know y never makes +it to zero because if y was Zero I + + align:start position:0% +it to zero because if y was Zero I + + + align:start position:0% +it to zero because if y was Zero I +couldn't no X would work so that and + + align:start position:0% +couldn't no X would work so that and + + + align:start position:0% +couldn't no X would work so that and +then but if if if I change that one to a + + align:start position:0% +then but if if if I change that one to a + + + align:start position:0% +then but if if if I change that one to a +four I've got a bigger I've got this is + + align:start position:0% +four I've got a bigger I've got this is + + + align:start position:0% +four I've got a bigger I've got this is +coming out here if I change that to a to + + align:start position:0% +coming out here if I change that to a to + + + align:start position:0% +coming out here if I change that to a to +something very small I'll get somebody + + align:start position:0% +something very small I'll get somebody + + + align:start position:0% +something very small I'll get somebody +I'll get one that's coming these are + + align:start position:0% +I'll get one that's coming these are + + + align:start position:0% +I'll get one that's coming these are +going do you see how the picture Works + + align:start position:0% +going do you see how the picture Works + + + align:start position:0% +going do you see how the picture Works +they these are all right + + align:start position:0% +they these are all right + + + align:start position:0% +they these are all right +angles that's the great thing right + + align:start position:0% +angles that's the great thing right + + + align:start position:0% +angles that's the great thing right +angles 90° + + align:start position:0% +angles 90° + + + align:start position:0% +angles 90° +angles the the between the streamlines + + align:start position:0% +angles the the between the streamlines + + + align:start position:0% +angles the the between the streamlines +and the equip potentials you you may + + align:start position:0% +and the equip potentials you you may + + + align:start position:0% +and the equip potentials you you may +have seen this before and now I'm just + + align:start position:0% +have seen this before and now I'm just + + + align:start position:0% +have seen this before and now I'm just +want to ask you why why are those 90 + + align:start position:0% +want to ask you why why are those 90 + + + align:start position:0% +want to ask you why why are those 90 +degrees we we kind of see it physically + + align:start position:0% +degrees we we kind of see it physically + + + align:start position:0% +degrees we we kind of see it physically +that the gradient is the you know the + + align:start position:0% +that the gradient is the you know the + + + align:start position:0% +that the gradient is the you know the +flow is in the gradient Direction and we + + align:start position:0% +flow is in the gradient Direction and we + + + align:start position:0% +flow is in the gradient Direction and we +know that gradients are always + + align:start position:0% +know that gradients are always + + + align:start position:0% +know that gradients are always +perpendicular to equip potential lines + + align:start position:0% +perpendicular to equip potential lines + + + align:start position:0% +perpendicular to equip potential lines +the gradient of any curve the gradient + + align:start position:0% +the gradient of any curve the gradient + + + align:start position:0% +the gradient of any curve the gradient +of any function is perpendicular to the + + align:start position:0% +of any function is perpendicular to the + + + align:start position:0% +of any function is perpendicular to the +level curves that's that's all we're + + align:start position:0% +level curves that's that's all we're + + + align:start position:0% +level curves that's that's all we're +seeing here but we're seeing this these + + align:start position:0% +seeing here but we're seeing this these + + + align:start position:0% +seeing here but we're seeing this these +two fantastic uh families of Curves + + align:start position:0% +two fantastic uh families of Curves + + + align:start position:0% +two fantastic uh families of Curves +equip potentials perpendicular to + + align:start position:0% +equip potentials perpendicular to + + + align:start position:0% +equip potentials perpendicular to +streamlines and the reason they're + + align:start position:0% +streamlines and the reason they're + + + align:start position:0% +streamlines and the reason they're +perpendicular is Koshi reman Koshi reman + + align:start position:0% +perpendicular is Koshi reman Koshi reman + + + align:start position:0% +perpendicular is Koshi reman Koshi reman +is telling us they're + + align:start position:0% +is telling us they're + + + align:start position:0% +is telling us they're +perpendicular because the gradient + + align:start position:0% +perpendicular because the gradient + + + align:start position:0% +perpendicular because the gradient +yeah you see that they're perpendicular + + align:start position:0% +yeah you see that they're perpendicular + + + align:start position:0% +yeah you see that they're perpendicular +is may be overkilled to to try to give a + + align:start position:0% +is may be overkilled to to try to give a + + + align:start position:0% +is may be overkilled to to try to give a +proof + + align:start position:0% +proof + + + align:start position:0% +proof +this the the gradient of + + align:start position:0% + + + + align:start position:0% + +U what I want to say is + + align:start position:0% +U what I want to say is + + + align:start position:0% +U what I want to say is +that the gradient of U is a 90° rotation + + align:start position:0% +that the gradient of U is a 90° rotation + + + align:start position:0% +that the gradient of U is a 90° rotation +of the gradient of s let me put it that + + align:start position:0% +of the gradient of s let me put it that + + + align:start position:0% +of the gradient of s let me put it that +way the gradient of s the gradient of + + align:start position:0% +way the gradient of s the gradient of + + + align:start position:0% +way the gradient of s the gradient of +U rotate + + align:start position:0% +U rotate + + + align:start position:0% +U rotate +90° + + align:start position:0% +90° + + + align:start position:0% +90° +rotate gradient of U by 90 by 90° pi + + align:start position:0% +rotate gradient of U by 90 by 90° pi + + + align:start position:0% +rotate gradient of U by 90 by 90° pi +over two and you get S you get grad + + align:start position:0% +over two and you get S you get grad + + + align:start position:0% +over two and you get S you get grad +s that's what these equations say that + + align:start position:0% +s that's what these equations say that + + + align:start position:0% +s that's what these equations say that +if if I take the gradient of + + align:start position:0% +if if I take the gradient of + + + align:start position:0% +if if I take the gradient of +U yeah let let me try to do that so I + + align:start position:0% +U yeah let let me try to do that so I + + + align:start position:0% +U yeah let let me try to do that so I +take the gradient of U that's D udx dud + + align:start position:0% +take the gradient of U that's D udx dud + + + align:start position:0% +take the gradient of U that's D udx dud +Dy so if I have a vector in 2D Dux D Dy + + align:start position:0% +Dy so if I have a vector in 2D Dux D Dy + + + align:start position:0% +Dy so if I have a vector in 2D Dux D Dy +and I want to find I want to rotate a + + align:start position:0% +and I want to find I want to rotate a + + + align:start position:0% +and I want to find I want to rotate a +vector by + + align:start position:0% +vector by + + + align:start position:0% +vector by +90° what what's the result suppose I + + align:start position:0% +90° what what's the result suppose I + + + align:start position:0% +90° what what's the result suppose I +have a vector + + align:start position:0% +have a vector + + + align:start position:0% +have a vector +ab and I'm looking to rotate it what's + + align:start position:0% +ab and I'm looking to rotate it what's + + + align:start position:0% +ab and I'm looking to rotate it what's +the vector that goes that way if that + + align:start position:0% +the vector that goes that way if that + + + align:start position:0% +the vector that goes that way if that +Vector is AB that Vector should be + + align:start position:0% + + + + align:start position:0% + +what you you may not have done this but + + align:start position:0% +what you you may not have done this but + + + align:start position:0% +what you you may not have done this but +it's it's worth just noticing because + + align:start position:0% +it's it's worth just noticing because + + + align:start position:0% +it's it's worth just noticing because +and you won't forget it it's got to have + + align:start position:0% +and you won't forget it it's got to have + + + align:start position:0% +and you won't forget it it's got to have +a zero dotproduct right so I'm looking + + align:start position:0% +a zero dotproduct right so I'm looking + + + align:start position:0% +a zero dotproduct right so I'm looking +for a vector here + + align:start position:0% +for a vector here + + + align:start position:0% +for a vector here +this went out a and up B I'm looking for + + align:start position:0% +this went out a and up B I'm looking for + + + align:start position:0% +this went out a and up B I'm looking for +a vector there that's perpendicular to + + align:start position:0% +a vector there that's perpendicular to + + + align:start position:0% +a vector there that's perpendicular to +this Vector so what should it do it yeah + + align:start position:0% +this Vector so what should it do it yeah + + + align:start position:0% +this Vector so what should it do it yeah +what what am I going to put + + align:start position:0% +what what am I going to put + + + align:start position:0% +what what am I going to put +there a b and what am I going to + + align:start position:0% +there a b and what am I going to + + + align:start position:0% +there a b and what am I going to +put oh no it it went backwards sorry + + align:start position:0% +put oh no it it went backwards sorry + + + align:start position:0% +put oh no it it went backwards sorry +when I put there I should have put minus + + align:start position:0% +when I put there I should have put minus + + + align:start position:0% +when I put there I should have put minus +B and and what goes there a yeah that's + + align:start position:0% +B and and what goes there a yeah that's + + + align:start position:0% +B and and what goes there a yeah that's +the that's the perpendicular one + + align:start position:0% +the that's the perpendicular one + + + align:start position:0% +the that's the perpendicular one +right if if that's the 90° rotation and + + align:start position:0% +right if if that's the 90° rotation and + + + align:start position:0% +right if if that's the 90° rotation and +that's what Koshi reman is doing for us + + align:start position:0% +that's what Koshi reman is doing for us + + + align:start position:0% +that's what Koshi reman is doing for us +I take the gradient that's I take this + + align:start position:0% +I take the gradient that's I take this + + + align:start position:0% +I take the gradient that's I take this +Vector now I rotate by 90° means I + + align:start position:0% +Vector now I rotate by 90° means I + + + align:start position:0% +Vector now I rotate by 90° means I +reverse these reverse a sign and I've + + align:start position:0% +reverse these reverse a sign and I've + + + align:start position:0% +reverse these reverse a sign and I've +got the gradient of s or minus the + + align:start position:0% +got the gradient of s or minus the + + + align:start position:0% +got the gradient of s or minus the +gradient of s I won't say whether the + + align:start position:0% +gradient of s I won't say whether the + + + align:start position:0% +gradient of s I won't say whether the +rotation is n Plus 90 degrees or minus + + align:start position:0% +rotation is n Plus 90 degrees or minus + + + align:start position:0% +rotation is n Plus 90 degrees or minus + + align:start position:0% + + + align:start position:0% +degrees this can remain an exercise to + + align:start position:0% +degrees this can remain an exercise to + + + align:start position:0% +degrees this can remain an exercise to +to uh to see it + + align:start position:0% +to uh to see it + + + align:start position:0% +to uh to see it +uh slowly and clearly I I I'm happy if + + align:start position:0% +uh slowly and clearly I I I'm happy if + + + align:start position:0% +uh slowly and clearly I I I'm happy if +you see it in the picture there and of + + align:start position:0% +you see it in the picture there and of + + + align:start position:0% +you see it in the picture there and of +course you saw it in this picture + + align:start position:0% +course you saw it in this picture + + + align:start position:0% +course you saw it in this picture +here so this is a moment then to take a + + align:start position:0% +here so this is a moment then to take a + + + align:start position:0% +here so this is a moment then to take a +little pause because we've got 10 + + align:start position:0% +little pause because we've got 10 + + + align:start position:0% +little pause because we've got 10 +minutes for the great event uh we've got + + align:start position:0% +minutes for the great event uh we've got + + + align:start position:0% +minutes for the great event uh we've got +the general idea the U equal constants + + align:start position:0% +the general idea the U equal constants + + + align:start position:0% +the general idea the U equal constants +and the S equal constant these two + + align:start position:0% +and the S equal constant these two + + + align:start position:0% +and the S equal constant these two +families of perpendicular curves one + + align:start position:0% +families of perpendicular curves one + + + align:start position:0% +families of perpendicular curves one +telling us where level level sets for + + align:start position:0% +telling us where level level sets for + + + align:start position:0% +telling us where level level sets for +the potential the other telling us the + + align:start position:0% +the potential the other telling us the + + + align:start position:0% +the potential the other telling us the +direction of the flow the flow goes + + align:start position:0% +direction of the flow the flow goes + + + align:start position:0% +direction of the flow the flow goes +perpendicular to those level sets it's + + align:start position:0% +perpendicular to those level sets it's + + + align:start position:0% +perpendicular to those level sets it's +just + + align:start position:0% +just + + + align:start position:0% +just +wonderful and now I would like + + align:start position:0% +wonderful and now I would like + + + align:start position:0% +wonderful and now I would like +to get + + align:start position:0% +to get + + + align:start position:0% +to get +a get the pattern that's going on here + + align:start position:0% +a get the pattern that's going on here + + + align:start position:0% +a get the pattern that's going on here +and complete that + + align:start position:0% +and complete that + + + align:start position:0% +and complete that +list + + align:start position:0% +list + + + align:start position:0% +list +okay well that pattern like comes out of + + align:start position:0% +okay well that pattern like comes out of + + + align:start position:0% +okay well that pattern like comes out of +the blue I have to + + align:start position:0% + + + + align:start position:0% + +admit you might sort of recognize that + + align:start position:0% +admit you might sort of recognize that + + + align:start position:0% +admit you might sort of recognize that +that something here's obviously stuff to + + align:start position:0% +that something here's obviously stuff to + + + align:start position:0% +that something here's obviously stuff to +the first Power here we've squared + + align:start position:0% +the first Power here we've squared + + + align:start position:0% +the first Power here we've squared +something to get here here we've cubed + + align:start position:0% +something to get here here we've cubed + + + align:start position:0% +something to get here here we've cubed +something do you you you sort of + + align:start position:0% +something do you you you sort of + + + align:start position:0% +something do you you you sort of +recognize these numbers one 331 or one + + align:start position:0% +recognize these numbers one 331 or one + + + align:start position:0% +recognize these numbers one 331 or one +minus 3 whatever that's we're we're + + align:start position:0% +minus 3 whatever that's we're we're + + + align:start position:0% +minus 3 whatever that's we're we're +we're + + align:start position:0% + + + + align:start position:0% + +uh yeah we're taking powers of something + + align:start position:0% +uh yeah we're taking powers of something + + + align:start position:0% +uh yeah we're taking powers of something +and that something + + align:start position:0% +and that something + + + align:start position:0% +and that something +is the what comes out of the blue + + align:start position:0% +is the what comes out of the blue + + + align:start position:0% +is the what comes out of the blue +it's this quantity X Plus i + + align:start position:0% + + + + align:start position:0% + +y complex variables everything here was + + align:start position:0% +y complex variables everything here was + + + align:start position:0% +y complex variables everything here was +real until this moment and then I'm + + align:start position:0% +real until this moment and then I'm + + + align:start position:0% +real until this moment and then I'm +saying that the complex number I the the + + align:start position:0% +saying that the complex number I the the + + + align:start position:0% +saying that the complex number I the the +the imaginary number I the square root + + align:start position:0% +the imaginary number I the square root + + + align:start position:0% +the imaginary number I the square root +of minus one which of course it just + + align:start position:0% +of minus one which of course it just + + + align:start position:0% +of minus one which of course it just +whatever I mean it's not a real number + + align:start position:0% +whatever I mean it's not a real number + + + align:start position:0% +whatever I mean it's not a real number +but it has the property whenever we see + + align:start position:0% +but it has the property whenever we see + + + align:start position:0% +but it has the property whenever we see +i^ s we write minus one so then we know + + align:start position:0% +i^ s we write minus one so then we know + + + align:start position:0% +i^ s we write minus one so then we know +how to deal with it okay sort of anyway + + align:start position:0% +how to deal with it okay sort of anyway + + + align:start position:0% +how to deal with it okay sort of anyway +so that complex number I'll call + + align:start position:0% +so that complex number I'll call + + + align:start position:0% +so that complex number I'll call +Z and here's what I + + align:start position:0% +Z and here's what I + + + align:start position:0% +Z and here's what I +think I think + + align:start position:0% +think I think + + + align:start position:0% +think I think +that these two pieces are the real and + + align:start position:0% +that these two pieces are the real and + + + align:start position:0% +that these two pieces are the real and +the imaginary parts of + + align:start position:0% +the imaginary parts of + + + align:start position:0% +the imaginary parts of +Z now these two pieces are the the real + + align:start position:0% +Z now these two pieces are the the real + + + align:start position:0% +Z now these two pieces are the the real +and the imaginary parts + + align:start position:0% +and the imaginary parts + + + align:start position:0% +and the imaginary parts +of z + + align:start position:0% +of z + + + align:start position:0% +of z +s these two pieces will be the real part + + align:start position:0% +s these two pieces will be the real part + + + align:start position:0% +s these two pieces will be the real part +and the imaginary part of z cubed and if + + align:start position:0% +and the imaginary part of z cubed and if + + + align:start position:0% +and the imaginary part of z cubed and if +you we check that and then we begin to + + align:start position:0% +you we check that and then we begin to + + + align:start position:0% +you we check that and then we begin to +see why should these satisfy thees + + align:start position:0% +see why should these satisfy thees + + + align:start position:0% +see why should these satisfy thees +equation we'll have the whole pattern + + align:start position:0% +equation we'll have the whole pattern + + + align:start position:0% +equation we'll have the whole pattern +it'll just be X+ i y to fourth power + + align:start position:0% +it'll just be X+ i y to fourth power + + + align:start position:0% +it'll just be X+ i y to fourth power +fifth power sixth power we can make a + + align:start position:0% +fifth power sixth power we can make a + + + align:start position:0% +fifth power sixth power we can make a +complete infinite list of pairs of + + align:start position:0% +complete infinite list of pairs of + + + align:start position:0% +complete infinite list of pairs of +solutions to lass's equation so can I + + align:start position:0% +solutions to lass's equation so can I + + + align:start position:0% +solutions to lass's equation so can I +just see let me just check what I said + + align:start position:0% +just see let me just check what I said + + + align:start position:0% +just see let me just check what I said +about uh the squares first how how do + + align:start position:0% +about uh the squares first how how do + + + align:start position:0% +about uh the squares first how how do +you do X+ i y squar because that's what + + align:start position:0% +you do X+ i y squar because that's what + + + align:start position:0% +you do X+ i y squar because that's what +I believe we're seeing in the in the + + align:start position:0% +I believe we're seeing in the in the + + + align:start position:0% +I believe we're seeing in the in the +quadratic list so I I claim that if I + + align:start position:0% +quadratic list so I I claim that if I + + + align:start position:0% +quadratic list so I I claim that if I +take x + I y^ 2 just just do it normally + + align:start position:0% +take x + I y^ 2 just just do it normally + + + align:start position:0% +take x + I y^ 2 just just do it normally +I get x2 and I get two I i x y and I get + + align:start position:0% +I get x2 and I get two I i x y and I get + + + align:start position:0% +I get x2 and I get two I i x y and I get +i^ 2 y^ 2 + + align:start position:0% +i^ 2 y^ 2 + + + align:start position:0% +i^ 2 y^ 2 +right I just squared it following normal + + align:start position:0% +right I just squared it following normal + + + align:start position:0% +right I just squared it following normal +algebra rules now what's the real part + + align:start position:0% +algebra rules now what's the real part + + + align:start position:0% +algebra rules now what's the real part +what's the real part of this X+ I y^ + + align:start position:0% +what's the real part of this X+ I y^ + + + align:start position:0% +what's the real part of this X+ I y^ +2 X2 this is + + align:start position:0% +2 X2 this is + + + align:start position:0% +2 X2 this is +real and this is real because i^ s is + + align:start position:0% +real and this is real because i^ s is + + + align:start position:0% +real and this is real because i^ s is +minus1 this is minus y^2 that's our + + align:start position:0% +minus1 this is minus y^2 that's our + + + align:start position:0% +minus1 this is minus y^2 that's our +that's our guy and the imaginary part + + align:start position:0% +that's our guy and the imaginary part + + + align:start position:0% +that's our guy and the imaginary part +is 2xy that's what multi the imaginary + + align:start position:0% +is 2xy that's what multi the imaginary + + + align:start position:0% +is 2xy that's what multi the imaginary +part is the part that multiplies I so by + + align:start position:0% +part is the part that multiplies I so by + + + align:start position:0% +part is the part that multiplies I so by +some magic that we'll we'll next time is + + align:start position:0% +some magic that we'll we'll next time is + + + align:start position:0% +some magic that we'll we'll next time is +the the the fun of exploring this magic + + align:start position:0% +the the the fun of exploring this magic + + + align:start position:0% +the the the fun of exploring this magic +we've get we get solutions to a real + + align:start position:0% +we've get we get solutions to a real + + + align:start position:0% +we've get we get solutions to a real +equation we get two solutions to a real + + align:start position:0% +equation we get two solutions to a real + + + align:start position:0% +equation we get two solutions to a real +equation by working with this complex + + align:start position:0% +equation by working with this complex + + + align:start position:0% +equation by working with this complex +thing X Plus i y and taking things like + + align:start position:0% +thing X Plus i y and taking things like + + + align:start position:0% +thing X Plus i y and taking things like +now if I go to X Plus y + + align:start position:0% +now if I go to X Plus y + + + align:start position:0% +now if I go to X Plus y +cubed well let me just say it'll + + align:start position:0% +cubed well let me just say it'll + + + align:start position:0% +cubed well let me just say it'll +work we'll have uh yeah you remember + + align:start position:0% +work we'll have uh yeah you remember + + + align:start position:0% +work we'll have uh yeah you remember +when it's like you know if you Cube + + align:start position:0% +when it's like you know if you Cube + + + align:start position:0% +when it's like you know if you Cube +something you're going to see 1331 + + align:start position:0% +something you're going to see 1331 + + + align:start position:0% +something you're going to see 1331 +you'll have an X cub and a 3 X2 i y and + + align:start position:0% +you'll have an X cub and a 3 X2 i y and + + + align:start position:0% +you'll have an X cub and a 3 X2 i y and +a 3X i y + + align:start position:0% +a 3X i y + + + align:start position:0% +a 3X i y +twice and an i and a one of the i y + + align:start position:0% +twice and an i and a one of the i y + + + align:start position:0% +twice and an i and a one of the i y +cubed + + align:start position:0% +cubed + + + align:start position:0% +cubed +and then you look to see what part is + + align:start position:0% +and then you look to see what part is + + + align:start position:0% +and then you look to see what part is +real and you say x Cub is real and i^2 + + align:start position:0% +real and you say x Cub is real and i^2 + + + align:start position:0% +real and you say x Cub is real and i^2 +is the minus so I have minus 3x y^2 + + align:start position:0% +is the minus so I have minus 3x y^2 + + + align:start position:0% +is the minus so I have minus 3x y^2 +golden and you look for what part is + + align:start position:0% +golden and you look for what part is + + + align:start position:0% +golden and you look for what part is +imaginary and you see the 3x^2 Y and you + + align:start position:0% +imaginary and you see the 3x^2 Y and you + + + align:start position:0% +imaginary and you see the 3x^2 Y and you +see the I cubed so what's I + + align:start position:0% +see the I cubed so what's I + + + align:start position:0% +see the I cubed so what's I +cubed is minus I so that's an imaginary + + align:start position:0% +cubed is minus I so that's an imaginary + + + align:start position:0% +cubed is minus I so that's an imaginary +term with a minus that we we wanted so + + align:start position:0% +term with a minus that we we wanted so + + + align:start position:0% +term with a minus that we we wanted so +now we've got the whole thing we've + + align:start position:0% +now we've got the whole thing we've + + + align:start position:0% +now we've got the whole thing we've +we've got solutions to thees equation + + align:start position:0% +we've got solutions to thees equation + + + align:start position:0% +we've got solutions to thees equation +coming + + align:start position:0% +coming + + + align:start position:0% +coming +from all the powers and that yeah this + + align:start position:0% +from all the powers and that yeah this + + + align:start position:0% +from all the powers and that yeah this +is this is now the moment to to + + align:start position:0% +is this is now the moment to to + + + align:start position:0% +is this is now the moment to to +celebrate right because we've got we've + + align:start position:0% +celebrate right because we've got we've + + + align:start position:0% +celebrate right because we've got we've +got a giant family of solutions to llas + + align:start position:0% +got a giant family of solutions to llas + + + align:start position:0% +got a giant family of solutions to llas +equation uh we've got all the we've got + + align:start position:0% +equation uh we've got all the we've got + + + align:start position:0% +equation uh we've got all the we've got +the real parts so U is the real part of + + align:start position:0% +the real parts so U is the real part of + + + align:start position:0% +the real parts so U is the real part of +X Plus i y to any power + + align:start position:0% +X Plus i y to any power + + + align:start position:0% +X Plus i y to any power +and S will be the imaginary + + align:start position:0% + + + + align:start position:0% + +part and I claim that just as we held + + align:start position:0% +part and I claim that just as we held + + + align:start position:0% +part and I claim that just as we held +for n equal 1 2 3 for every n these will + + align:start position:0% +for n equal 1 2 3 for every n these will + + + align:start position:0% +for n equal 1 2 3 for every n these will +be solutions to the plas equation + + align:start position:0% +be solutions to the plas equation + + + align:start position:0% +be solutions to the plas equation +they'll not only that they'll be + + align:start position:0% +they'll not only that they'll be + + + align:start position:0% +they'll not only that they'll be +connected by Koshi remon so they'll be + + align:start position:0% +connected by Koshi remon so they'll be + + + align:start position:0% +connected by Koshi remon so they'll be +uh the the potential and the stream + + align:start position:0% +uh the the potential and the stream + + + align:start position:0% +uh the the potential and the stream +function for for a for a flow and uh and + + align:start position:0% +function for for a for a flow and uh and + + + align:start position:0% +function for for a for a flow and uh and +we've got lots of + + align:start position:0% +we've got lots of + + + align:start position:0% +we've got lots of +them + + align:start position:0% +them + + + align:start position:0% +them +and well we got even more because we + + align:start position:0% +and well we got even more because we + + + align:start position:0% +and well we got even more because we +have linear equation here so what are we + + align:start position:0% +have linear equation here so what are we + + + align:start position:0% +have linear equation here so what are we +allowed to do if we have solutions to a + + align:start position:0% +allowed to do if we have solutions to a + + + align:start position:0% +allowed to do if we have solutions to a +linear equation what are we allowed to + + align:start position:0% +linear equation what are we allowed to + + + align:start position:0% +linear equation what are we allowed to +do with those solutions to get more + + align:start position:0% +do with those solutions to get more + + + align:start position:0% +do with those solutions to get more +solutions combine + + align:start position:0% +solutions combine + + + align:start position:0% +solutions combine +them I can take any combination of these + + align:start position:0% +them I can take any combination of these + + + align:start position:0% +them I can take any combination of these +guys I can take or so and or I don't + + align:start position:0% +guys I can take or so and or I don't + + + align:start position:0% +guys I can take or so and or I don't +know which should put or + + align:start position:0% +know which should put or + + + align:start position:0% +know which should put or +and uh the real part of any combination + + align:start position:0% +and uh the real part of any combination + + + align:start position:0% +and uh the real part of any combination +of these so I could take a + + align:start position:0% +of these so I could take a + + + align:start position:0% +of these so I could take a +combination of I can take coefficients + + align:start position:0% +combination of I can take coefficients + + + align:start position:0% +combination of I can take coefficients +CK or CN maybe I should say + + align:start position:0% +CK or CN maybe I should say + + + align:start position:0% +CK or CN maybe I should say +CN x + i y to the + + align:start position:0% +CN x + i y to the + + + align:start position:0% +CN x + i y to the +N so if I take a combination of + + align:start position:0% +N so if I take a combination of + + + align:start position:0% +N so if I take a combination of +solutions with with coefficients CN I + + align:start position:0% +solutions with with coefficients CN I + + + align:start position:0% +solutions with with coefficients CN I +still have Solutions and what will be + + align:start position:0% +still have Solutions and what will be + + + align:start position:0% +still have Solutions and what will be +the twin solution or the the the uh the + + align:start position:0% +the twin solution or the the the uh the + + + align:start position:0% +the twin solution or the the the uh the +stream function that goes with this U so + + align:start position:0% +stream function that goes with this U so + + + align:start position:0% +stream function that goes with this U so +this is another U this is a one this is + + align:start position:0% +this is another U this is a one this is + + + align:start position:0% +this is another U this is a one this is +a really virtually a complete family of + + align:start position:0% +a really virtually a complete family of + + + align:start position:0% +a really virtually a complete family of +use because we have all these + + align:start position:0% +use because we have all these + + + align:start position:0% +use because we have all these +coefficients to choose and what will be + + align:start position:0% +coefficients to choose and what will be + + + align:start position:0% +coefficients to choose and what will be +the S so I what's the corresponding s + + align:start position:0% +the S so I what's the corresponding s + + + align:start position:0% +the S so I what's the corresponding s +then it's the imaginary part + + align:start position:0% +then it's the imaginary part + + + align:start position:0% +then it's the imaginary part +of what the same + + align:start position:0% +of what the same + + + align:start position:0% +of what the same +thing the same we're just taking that + + align:start position:0% +thing the same we're just taking that + + + align:start position:0% +thing the same we're just taking that +same combination of + + align:start position:0% +same combination of + + + align:start position:0% +same combination of +the of the uh of the special ones so the + + align:start position:0% +the of the uh of the special ones so the + + + align:start position:0% +the of the uh of the special ones so the +special ones were X Plus i y to the nth + + align:start position:0% +special ones were X Plus i y to the nth + + + align:start position:0% +special ones were X Plus i y to the nth +and the combinations are those yeah + + align:start position:0% +and the combinations are those yeah + + + align:start position:0% +and the combinations are those yeah +that's these are fantastic Solutions and + + align:start position:0% +that's these are fantastic Solutions and + + + align:start position:0% +that's these are fantastic Solutions and +now since I blessed with two more + + align:start position:0% +now since I blessed with two more + + + align:start position:0% +now since I blessed with two more +minutes I get to + + align:start position:0% +minutes I get to + + + align:start position:0% +minutes I get to +make them much easier because well + + align:start position:0% +make them much easier because well + + + align:start position:0% +make them much easier because well +already when I got up to X Cube and Y + + align:start position:0% +already when I got up to X Cube and Y + + + align:start position:0% +already when I got up to X Cube and Y +Cube they they're looking messy you say + + align:start position:0% +Cube they they're looking messy you say + + + align:start position:0% +Cube they they're looking messy you say +h you say okay great to have all these + + align:start position:0% +h you say okay great to have all these + + + align:start position:0% +h you say okay great to have all these +Solutions but how am I going to use them + + align:start position:0% +Solutions but how am I going to use them + + + align:start position:0% +Solutions but how am I going to use them +you know they're they're they're they're + + align:start position:0% +you know they're they're they're they're + + + align:start position:0% +you know they're they're they're they're +uh uh getting more and more complicated + + align:start position:0% +uh uh getting more and more complicated + + + align:start position:0% +uh uh getting more and more complicated +as an increases but switch to Polar + + align:start position:0% +as an increases but switch to Polar + + + align:start position:0% +as an increases but switch to Polar +coordinates make the same list in polar + + align:start position:0% +coordinates make the same list in polar + + + align:start position:0% +coordinates make the same list in polar +coordinates so again I'm just going to + + align:start position:0% +coordinates so again I'm just going to + + + align:start position:0% +coordinates so again I'm just going to +list the same guys in polar coordinates + + align:start position:0% +list the same guys in polar coordinates + + + align:start position:0% +list the same guys in polar coordinates +are + + align:start position:0% + + + + align:start position:0% + +Theta then you'll see the then the + + align:start position:0% +Theta then you'll see the then the + + + align:start position:0% +Theta then you'll see the then the +pattern really jumps out so what is x in + + align:start position:0% +pattern really jumps out so what is x in + + + align:start position:0% +pattern really jumps out so what is x in +polar + + align:start position:0% +polar + + + align:start position:0% +polar +coordinates you if I switch from XY + + align:start position:0% +coordinates you if I switch from XY + + + align:start position:0% +coordinates you if I switch from XY +rectangular coordinates to R Theta polar + + align:start position:0% +rectangular coordinates to R Theta polar + + + align:start position:0% +rectangular coordinates to R Theta polar +coordinates X is R cos Theta and Y + + align:start position:0% +coordinates X is R cos Theta and Y + + + align:start position:0% +coordinates X is R cos Theta and Y +is R sin Theta okay well so so far done + + align:start position:0% +is R sin Theta okay well so so far done + + + align:start position:0% +is R sin Theta okay well so so far done +any easier X and Y looked fine but let + + align:start position:0% +any easier X and Y looked fine but let + + + align:start position:0% +any easier X and Y looked fine but let +me go to the second second one so this + + align:start position:0% +me go to the second second one so this + + + align:start position:0% +me go to the second second one so this +is now R 2 cos 2 Theta right minus this + + align:start position:0% +is now R 2 cos 2 Theta right minus this + + + align:start position:0% +is now R 2 cos 2 Theta right minus this +is r s sin s + + align:start position:0% + + + + align:start position:0% + +Theta + + align:start position:0% +Theta + + + align:start position:0% +Theta +trigonometry comes in I have r^ 2 cos 2 + + align:start position:0% +trigonometry comes in I have r^ 2 cos 2 + + + align:start position:0% +trigonometry comes in I have r^ 2 cos 2 +Theta minus r^ 2 sin 2 Theta I want to I + + align:start position:0% +Theta minus r^ 2 sin 2 Theta I want to I + + + align:start position:0% +Theta minus r^ 2 sin 2 Theta I want to I +want to + + align:start position:0% +want to + + + align:start position:0% +want to +simplify that so it's got an R + + align:start position:0% +simplify that so it's got an R + + + align:start position:0% +simplify that so it's got an R +2 and it's got a COS 2 thet minus sin 2 + + align:start position:0% +2 and it's got a COS 2 thet minus sin 2 + + + align:start position:0% +2 and it's got a COS 2 thet minus sin 2 +thet anybody remember that cosine of 2 + + align:start position:0% + + + + align:start position:0% + +Theta and this + + align:start position:0% +Theta and this + + + align:start position:0% +Theta and this +one well what do you think it's + + align:start position:0% +one well what do you think it's + + + align:start position:0% +one well what do you think it's +coming what do you think is coming here + + align:start position:0% +coming what do you think is coming here + + + align:start position:0% +coming what do you think is coming here +I have two R cos Theta * R sin Theta I + + align:start position:0% +I have two R cos Theta * R sin Theta I + + + align:start position:0% +I have two R cos Theta * R sin Theta I +have two I've got an r s again + + align:start position:0% +have two I've got an r s again + + + align:start position:0% +have two I've got an r s again +time 2 cos Theta sin Theta so what's 2 + + align:start position:0% +time 2 cos Theta sin Theta so what's 2 + + + align:start position:0% +time 2 cos Theta sin Theta so what's 2 +cos Theta sin Theta sin 2 Theta you get + + align:start position:0% +cos Theta sin Theta sin 2 Theta you get + + + align:start position:0% +cos Theta sin Theta sin 2 Theta you get +it sin 2 Theta and you + + align:start position:0% +it sin 2 Theta and you + + + align:start position:0% +it sin 2 Theta and you +know what's coming next right you know + + align:start position:0% +know what's coming next right you know + + + align:start position:0% +know what's coming next right you know +that now the whole family in polar + + align:start position:0% +that now the whole family in polar + + + align:start position:0% +that now the whole family in polar +coordinates what's the what's the N + + align:start position:0% +coordinates what's the what's the N + + + align:start position:0% +coordinates what's the what's the N +power what's the N what's the N we can + + align:start position:0% +power what's the N what's the N we can + + + align:start position:0% +power what's the N what's the N we can +now write down the nth one in this list + + align:start position:0% +now write down the nth one in this list + + + align:start position:0% +now write down the nth one in this list +it is R to the nth or the nth + + align:start position:0% +it is R to the nth or the nth + + + align:start position:0% +it is R to the nth or the nth +R to the N + + align:start position:0% +R to the N + + + align:start position:0% +R to the N +time + + align:start position:0% +time + + + align:start position:0% +time +cos n Theta and R to the n s in Theta is + + align:start position:0% +cos n Theta and R to the n s in Theta is + + + align:start position:0% +cos n Theta and R to the n s in Theta is +it so those are the those are the uh + + align:start position:0% +it so those are the those are the uh + + + align:start position:0% +it so those are the those are the uh +twins the the U and the s that we get if + + align:start position:0% +twins the the U and the s that we get if + + + align:start position:0% +twins the the U and the s that we get if +we write if we use polar + + align:start position:0% +we write if we use polar + + + align:start position:0% +we write if we use polar +coordinates so that's uh just terrific + + align:start position:0% +coordinates so that's uh just terrific + + + align:start position:0% +coordinates so that's uh just terrific +now we have a whole lot of solutions to + + align:start position:0% +now we have a whole lot of solutions to + + + align:start position:0% +now we have a whole lot of solutions to +the ples equation + + align:start position:0% +the ples equation + + + align:start position:0% +the ples equation +and we have don't forget all + + align:start position:0% +and we have don't forget all + + + align:start position:0% +and we have don't forget all +combinations of + + align:start position:0% +combinations of + + + align:start position:0% +combinations of +them and we're really ready to go so + + align:start position:0% +them and we're really ready to go so + + + align:start position:0% +them and we're really ready to go so +when so Friday we'll be solving the ples + + align:start position:0% +when so Friday we'll be solving the ples + + + align:start position:0% +when so Friday we'll be solving the ples +equation by in the cases that we can do + + align:start position:0% +equation by in the cases that we can do + + + align:start position:0% +equation by in the cases that we can do +it by pencil and paper by chalk and then + + align:start position:0% +it by pencil and paper by chalk and then + + + align:start position:0% +it by pencil and paper by chalk and then +after that comes solving Theus equation + + align:start position:0% +after that comes solving Theus equation + + + align:start position:0% +after that comes solving Theus equation +by finite differences and finite + + align:start position:0% +by finite differences and finite + + + align:start position:0% +by finite differences and finite +elements okay \ No newline at end of file diff --git a/nPJRjMh9evk.txt b/nPJRjMh9evk.txt new file mode 100644 index 0000000000000000000000000000000000000000..a86eb14a252cdc4394d01c71a0ceeefa045644f1 --- /dev/null +++ b/nPJRjMh9evk.txt @@ -0,0 +1,7203 @@ +align:start position:0% + +foreign + + align:start position:0% + + + + align:start position:0% + +modeling and now we're going to start to + + align:start position:0% +modeling and now we're going to start to + + + align:start position:0% +modeling and now we're going to start to +see how it's done so this is the outline + + align:start position:0% +see how it's done so this is the outline + + + align:start position:0% +see how it's done so this is the outline +of today's lecture because we're going + + align:start position:0% +of today's lecture because we're going + + + align:start position:0% +of today's lecture because we're going +to cover a lot + + align:start position:0% +to cover a lot + + + align:start position:0% +to cover a lot +um I don't mind covering a lot here + + align:start position:0% + + + + align:start position:0% + +it's covered well in the text as well so + + align:start position:0% +it's covered well in the text as well so + + + align:start position:0% +it's covered well in the text as well so +this is basically a + + align:start position:0% + + + + align:start position:0% + +you know I'm I'm being a tour guide here + + align:start position:0% + + + + align:start position:0% + +so we're going to start by introducing + + align:start position:0% +so we're going to start by introducing + + + align:start position:0% +so we're going to start by introducing +the ideal solution model + + align:start position:0% +the ideal solution model + + + align:start position:0% +the ideal solution model +then we're going to talk about non + + align:start position:0% +then we're going to talk about non + + + align:start position:0% +then we're going to talk about non +ideal + + align:start position:0% + + + + align:start position:0% + +solution models + + align:start position:0% + + + + align:start position:0% + +we're going to talk about two particular + + align:start position:0% +we're going to talk about two particular + + + align:start position:0% +we're going to talk about two particular +types of non-ideal solution models + + align:start position:0% +types of non-ideal solution models + + + align:start position:0% +types of non-ideal solution models +dilute solution + + align:start position:0% + + + + align:start position:0% + +model + + align:start position:0% +model + + + align:start position:0% +model +and regular solution model + + align:start position:0% + + + + align:start position:0% + +and I hope folks are ahead of me + + align:start position:0% +and I hope folks are ahead of me + + + align:start position:0% +and I hope folks are ahead of me +um and I've read chapter eight in the + + align:start position:0% +um and I've read chapter eight in the + + + align:start position:0% +um and I've read chapter eight in the +book and if you have uh it will help + + align:start position:0% + + + + align:start position:0% + +okay so let's talk about first ideal gas + + align:start position:0% +okay so let's talk about first ideal gas + + + align:start position:0% +okay so let's talk about first ideal gas +Solutions we've already done this + + align:start position:0% +Solutions we've already done this + + + align:start position:0% +Solutions we've already done this +actually + + align:start position:0% +actually + + + align:start position:0% +actually +we've already done this ideal gas + + align:start position:0% +we've already done this ideal gas + + + align:start position:0% +we've already done this ideal gas +Solutions + + align:start position:0% +Solutions + + + align:start position:0% +Solutions +right we have pure + + align:start position:0% +right we have pure + + + align:start position:0% +right we have pure +a at temperature pressure + + align:start position:0% +a at temperature pressure + + + align:start position:0% +a at temperature pressure +and some volume + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +we have Pier B at some temperature and + + align:start position:0% +we have Pier B at some temperature and + + + align:start position:0% +we have Pier B at some temperature and +pressure same temperature same pressure + + align:start position:0% +pressure same temperature same pressure + + + align:start position:0% +pressure same temperature same pressure +and in general a different volume + + align:start position:0% +and in general a different volume + + + align:start position:0% +and in general a different volume +and + + align:start position:0% +and + + + align:start position:0% +and +we mix them + + align:start position:0% +we mix them + + + align:start position:0% +we mix them +and if these are ideal gases PV equals + + align:start position:0% +and if these are ideal gases PV equals + + + align:start position:0% +and if these are ideal gases PV equals +nrt tells us + + align:start position:0% +nrt tells us + + + align:start position:0% +nrt tells us +that we get a and b + + align:start position:0% +that we get a and b + + + align:start position:0% +that we get a and b +at the same temperature same pressure + + align:start position:0% +at the same temperature same pressure + + + align:start position:0% +at the same temperature same pressure +and a total volume that is simply the + + align:start position:0% +and a total volume that is simply the + + + align:start position:0% +and a total volume that is simply the +sum + + align:start position:0% + + + + align:start position:0% + +of the two volumes + + align:start position:0% +of the two volumes + + + align:start position:0% +of the two volumes +so this is for ideal gases + + align:start position:0% +so this is for ideal gases + + + align:start position:0% +so this is for ideal gases +all right so we know this and we've seen + + align:start position:0% +all right so we know this and we've seen + + + align:start position:0% +all right so we know this and we've seen +that we can model this + + align:start position:0% + + + + align:start position:0% + +process this process of making the + + align:start position:0% +process this process of making the + + + align:start position:0% +process this process of making the +mixture + + align:start position:0% +mixture + + + align:start position:0% +mixture +as an isothermal + + align:start position:0% + + + + align:start position:0% + +an isothermal expansion for each gas so + + align:start position:0% +an isothermal expansion for each gas so + + + align:start position:0% +an isothermal expansion for each gas so +we've seen this and this is the result + + align:start position:0% +we've seen this and this is the result + + + align:start position:0% +we've seen this and this is the result +we got + + align:start position:0% +we got + + + align:start position:0% +we got +isothermal change and chemical potential + + align:start position:0% +isothermal change and chemical potential + + + align:start position:0% +isothermal change and chemical potential +is molar Gibbs tree energy + + align:start position:0% + + + + align:start position:0% + +that means + + align:start position:0% +that means + + + align:start position:0% +that means +the total change + + align:start position:0% +the total change + + + align:start position:0% +the total change +and the chemical potential of each + + align:start position:0% +and the chemical potential of each + + + align:start position:0% +and the chemical potential of each +component throughout this process + + align:start position:0% +component throughout this process + + + align:start position:0% +component throughout this process +is going to be the integral of its + + align:start position:0% +is going to be the integral of its + + + align:start position:0% +is going to be the integral of its +partial pressure times V + + align:start position:0% +partial pressure times V + + + align:start position:0% +partial pressure times V +and making this a little bit more + + align:start position:0% +and making this a little bit more + + + align:start position:0% +and making this a little bit more +explicit this is from P to P sub I + + align:start position:0% +explicit this is from P to P sub I + + + align:start position:0% +explicit this is from P to P sub I +d p + + align:start position:0% +d p + + + align:start position:0% +d p +Ummy variable RT + + align:start position:0% +Ummy variable RT + + + align:start position:0% +Ummy variable RT +over p + + align:start position:0% +over p + + + align:start position:0% +over p +and this equals RT Ln partial pressure + + align:start position:0% +and this equals RT Ln partial pressure + + + align:start position:0% +and this equals RT Ln partial pressure +of I over the total pressure we've + + align:start position:0% +of I over the total pressure we've + + + align:start position:0% +of I over the total pressure we've +we already worked on this we derived + + align:start position:0% +we already worked on this we derived + + + align:start position:0% +we already worked on this we derived +this already and this is + + align:start position:0% + + + + align:start position:0% + +this is the change of chemical potential + + align:start position:0% +this is the change of chemical potential + + + align:start position:0% +this is the change of chemical potential +for isothermal expansion + + align:start position:0% + + + + align:start position:0% + +this is also + + align:start position:0% + + + + align:start position:0% + +and here's the new part this is also + + align:start position:0% +and here's the new part this is also + + + align:start position:0% +and here's the new part this is also +Delta Mu of I + + align:start position:0% +Delta Mu of I + + + align:start position:0% +Delta Mu of I +for the mixing process well that's + + align:start position:0% +for the mixing process well that's + + + align:start position:0% +for the mixing process well that's +actually not new we use this in the + + align:start position:0% +actually not new we use this in the + + + align:start position:0% +actually not new we use this in the +previous unit on reacting gas systems + + align:start position:0% +previous unit on reacting gas systems + + + align:start position:0% +previous unit on reacting gas systems +but + + align:start position:0% +but + + + align:start position:0% +but +um we're gonna we're gonna really focus + + align:start position:0% +um we're gonna we're gonna really focus + + + align:start position:0% +um we're gonna we're gonna really focus +on this this is + + align:start position:0% +on this this is + + + align:start position:0% +on this this is +this Delta is now going to correspond + + align:start position:0% +this Delta is now going to correspond + + + align:start position:0% +this Delta is now going to correspond +to the mixing process + + align:start position:0% +to the mixing process + + + align:start position:0% +to the mixing process +so this is Delta for the mixing process + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so what is the Gibbs free energy + + align:start position:0% + + + + align:start position:0% + +of this mixing process + + align:start position:0% + + + + align:start position:0% + +we know how to write that down now + + align:start position:0% +we know how to write that down now + + + align:start position:0% +we know how to write that down now +because we've sort of done the rudiments + + align:start position:0% +because we've sort of done the rudiments + + + align:start position:0% +because we've sort of done the rudiments +of + + align:start position:0% +of + + + align:start position:0% +of +solution modeling + + align:start position:0% +solution modeling + + + align:start position:0% +solution modeling +it's a sum + + align:start position:0% +it's a sum + + + align:start position:0% +it's a sum +weighted sum by molar mole fraction of + + align:start position:0% +weighted sum by molar mole fraction of + + + align:start position:0% +weighted sum by molar mole fraction of +the partial molar property + + align:start position:0% + + + + align:start position:0% + +and we just take from the previous board + + align:start position:0% +and we just take from the previous board + + + align:start position:0% +and we just take from the previous board +so what we're going to do is we we wrote + + align:start position:0% +so what we're going to do is we we wrote + + + align:start position:0% +so what we're going to do is we we wrote +down sorry about that we wrote down the + + align:start position:0% +down sorry about that we wrote down the + + + align:start position:0% +down sorry about that we wrote down the +partial molar properties the partial + + align:start position:0% +partial molar properties the partial + + + align:start position:0% +partial molar properties the partial +molar gives free energy that is the + + align:start position:0% +molar gives free energy that is the + + + align:start position:0% +molar gives free energy that is the +change of chemical potential with mixing + + align:start position:0% +change of chemical potential with mixing + + + align:start position:0% +change of chemical potential with mixing +and now we can write this using the sort + + align:start position:0% +and now we can write this using the sort + + + align:start position:0% +and now we can write this using the sort +of formalism that we already have seen + + align:start position:0% +of formalism that we already have seen + + + align:start position:0% +of formalism that we already have seen +so it's the sum of the mole fractions + + align:start position:0% +so it's the sum of the mole fractions + + + align:start position:0% +so it's the sum of the mole fractions +and the partial molar property and we + + align:start position:0% +and the partial molar property and we + + + align:start position:0% +and the partial molar property and we +just borrow from the previous slide this + + align:start position:0% +just borrow from the previous slide this + + + align:start position:0% +just borrow from the previous slide this +is x i r of t log P of I over p and + + align:start position:0% +is x i r of t log P of I over p and + + + align:start position:0% +is x i r of t log P of I over p and +we're going to use Dalton's rule to + + align:start position:0% +we're going to use Dalton's rule to + + + align:start position:0% +we're going to use Dalton's rule to +re-express the argument in the log as a + + align:start position:0% +re-express the argument in the log as a + + + align:start position:0% +re-express the argument in the log as a +mole fraction and so this is a solution + + align:start position:0% +mole fraction and so this is a solution + + + align:start position:0% +mole fraction and so this is a solution +model + + align:start position:0% +model + + + align:start position:0% +model +we've talked about solution models but + + align:start position:0% +we've talked about solution models but + + + align:start position:0% +we've talked about solution models but +we we haven't actually seen one written + + align:start position:0% +we we haven't actually seen one written + + + align:start position:0% +we we haven't actually seen one written +down mathematically before so this is + + align:start position:0% +down mathematically before so this is + + + align:start position:0% +down mathematically before so this is +one this is actually an important one so + + align:start position:0% +one this is actually an important one so + + + align:start position:0% +one this is actually an important one so +let's let's graph this and see what it + + align:start position:0% +let's let's graph this and see what it + + + align:start position:0% +let's let's graph this and see what it +looks like + + align:start position:0% +looks like + + + align:start position:0% +looks like +so I'm going to graph Delta G of mixing + + align:start position:0% +so I'm going to graph Delta G of mixing + + + align:start position:0% +so I'm going to graph Delta G of mixing +and the first thing is is that it's + + align:start position:0% +and the first thing is is that it's + + + align:start position:0% +and the first thing is is that it's +strictly negative + + align:start position:0% +strictly negative + + + align:start position:0% +strictly negative +and you can see that + + align:start position:0% +and you can see that + + + align:start position:0% +and you can see that +by the log expression both fractions are + + align:start position:0% +by the log expression both fractions are + + + align:start position:0% +by the log expression both fractions are +less than or equal to one + + align:start position:0% +less than or equal to one + + + align:start position:0% +less than or equal to one +so this this sum is less than or equal + + align:start position:0% +so this this sum is less than or equal + + + align:start position:0% +so this this sum is less than or equal +to zero and so + + align:start position:0% +to zero and so + + + align:start position:0% +to zero and so +um so that's that's an important thing + + align:start position:0% +um so that's that's an important thing + + + align:start position:0% +um so that's that's an important thing +to observe + + align:start position:0% + + + + align:start position:0% + +you have a family here + + align:start position:0% + + + + align:start position:0% + +with increasing + + align:start position:0% +with increasing + + + align:start position:0% +with increasing +temp + + align:start position:0% +temp + + + align:start position:0% +temp +so the first thing to observe here is + + align:start position:0% +so the first thing to observe here is + + + align:start position:0% +so the first thing to observe here is +that um + + align:start position:0% +that um + + + align:start position:0% +that um +there are very few parameters in this + + align:start position:0% +there are very few parameters in this + + + align:start position:0% +there are very few parameters in this +model + + align:start position:0% +model + + + align:start position:0% +model +this is the composition X of I + + align:start position:0% +this is the composition X of I + + + align:start position:0% +this is the composition X of I +and there's temperature and that's it so + + align:start position:0% +and there's temperature and that's it so + + + align:start position:0% +and there's temperature and that's it so +if I plotted the solution model versus + + align:start position:0% +if I plotted the solution model versus + + + align:start position:0% +if I plotted the solution model versus +composition I'm going to have a family + + align:start position:0% +composition I'm going to have a family + + + align:start position:0% +composition I'm going to have a family +of Curves in varying temperature + + align:start position:0% +of Curves in varying temperature + + + align:start position:0% +of Curves in varying temperature +and the way this is going to work is + + align:start position:0% +and the way this is going to work is + + + align:start position:0% +and the way this is going to work is +with increasing temperature Delta g mix + + align:start position:0% +with increasing temperature Delta g mix + + + align:start position:0% +with increasing temperature Delta g mix +gets more negative + + align:start position:0% +gets more negative + + + align:start position:0% +gets more negative +so we're going to note that + + align:start position:0% +so we're going to note that + + + align:start position:0% +so we're going to note that +note + + align:start position:0% +note + + + align:start position:0% +note +Delta G mixture + + align:start position:0% +Delta G mixture + + + align:start position:0% +Delta G mixture +is less than zero + + align:start position:0% +is less than zero + + + align:start position:0% +is less than zero +and + + align:start position:0% +and + + + align:start position:0% +and +D Squared + + align:start position:0% +D Squared + + + align:start position:0% +D Squared +Delta g mix + + align:start position:0% +Delta g mix + + + align:start position:0% +Delta g mix +dx2 squared + + align:start position:0% +dx2 squared + + + align:start position:0% +dx2 squared +is greater than zero + + align:start position:0% +is greater than zero + + + align:start position:0% +is greater than zero +everywhere + + align:start position:0% +everywhere + + + align:start position:0% +everywhere +so + + align:start position:0% + + + + align:start position:0% + +so that is it's negative and it's curved + + align:start position:0% +so that is it's negative and it's curved + + + align:start position:0% +so that is it's negative and it's curved +up everywhere + + align:start position:0% +up everywhere + + + align:start position:0% +up everywhere +and what we're going to see in a couple + + align:start position:0% +and what we're going to see in a couple + + + align:start position:0% +and what we're going to see in a couple +lectures + + align:start position:0% + + + + align:start position:0% + +is um + + align:start position:0% + + + + align:start position:0% + +mathematically this ensures that the + + align:start position:0% +mathematically this ensures that the + + + align:start position:0% +mathematically this ensures that the +mixing is always spontaneous + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% +um + + + align:start position:0% +um +which is good because we expect that to + + align:start position:0% +which is good because we expect that to + + + align:start position:0% +which is good because we expect that to +be the case for ideal gases mixing this + + align:start position:0% +be the case for ideal gases mixing this + + + align:start position:0% +be the case for ideal gases mixing this +goes back to the baby book right when + + align:start position:0% +goes back to the baby book right when + + + align:start position:0% +goes back to the baby book right when +you have these two populations of gas + + align:start position:0% +you have these two populations of gas + + + align:start position:0% +you have these two populations of gas +molecules and they don't interact with + + align:start position:0% +molecules and they don't interact with + + + align:start position:0% +molecules and they don't interact with +each other and you remove the barrier + + align:start position:0% +each other and you remove the barrier + + + align:start position:0% +each other and you remove the barrier +between them you expect them to mix + + align:start position:0% +between them you expect them to mix + + + align:start position:0% +between them you expect them to mix +spontaneously and that's what this map + + align:start position:0% +spontaneously and that's what this map + + + align:start position:0% +spontaneously and that's what this map +is + + align:start position:0% +is + + + align:start position:0% +is +um + + align:start position:0% +um + + + align:start position:0% +um +enforcing + + align:start position:0% +enforcing + + + align:start position:0% +enforcing +so + + align:start position:0% +so + + + align:start position:0% +so +okay + + align:start position:0% +okay + + + align:start position:0% +okay +um so now what we're going to do is + + align:start position:0% +um so now what we're going to do is + + + align:start position:0% +um so now what we're going to do is +we're just going to abstract this a + + align:start position:0% +we're just going to abstract this a + + + align:start position:0% +we're just going to abstract this a +little bit and call everything we just + + align:start position:0% +little bit and call everything we just + + + align:start position:0% +little bit and call everything we just +did the ideal + + align:start position:0% +did the ideal + + + align:start position:0% +did the ideal +solution + + align:start position:0% +solution + + + align:start position:0% +solution +model + + align:start position:0% + + + + align:start position:0% + +the ideal solution model and we can + + align:start position:0% +the ideal solution model and we can + + + align:start position:0% +the ideal solution model and we can +write it down very compactly + + align:start position:0% + + + + align:start position:0% + +all right so this model it's motivated + + align:start position:0% + + + + align:start position:0% + +motivated by or derived from + + align:start position:0% + + + + align:start position:0% + +ideal gas mixing + + align:start position:0% + + + + align:start position:0% + +but it approximates + + align:start position:0% + + + + align:start position:0% + +a broader class + + align:start position:0% + + + + align:start position:0% + +of real world systems + + align:start position:0% + + + + align:start position:0% + +so this is very typical in science you + + align:start position:0% +so this is very typical in science you + + + align:start position:0% +so this is very typical in science you +have some simple case you treat it as a + + align:start position:0% +have some simple case you treat it as a + + + align:start position:0% +have some simple case you treat it as a +model system + + align:start position:0% +model system + + + align:start position:0% +model system +you develop the model you study the + + align:start position:0% +you develop the model you study the + + + align:start position:0% +you develop the model you study the +model and then you say oh well maybe + + align:start position:0% +model and then you say oh well maybe + + + align:start position:0% +model and then you say oh well maybe +this model applies elsewhere maybe it + + align:start position:0% +this model applies elsewhere maybe it + + + align:start position:0% +this model applies elsewhere maybe it +does maybe it doesn't + + align:start position:0% +does maybe it doesn't + + + align:start position:0% +does maybe it doesn't +so here are some properties of the ideal + + align:start position:0% +so here are some properties of the ideal + + + align:start position:0% +so here are some properties of the ideal +solution model + + align:start position:0% +solution model + + + align:start position:0% +solution model +the partial molar entropy of mixing + + align:start position:0% +the partial molar entropy of mixing + + + align:start position:0% +the partial molar entropy of mixing +we can get this from the combined + + align:start position:0% +we can get this from the combined + + + align:start position:0% +we can get this from the combined +statement + + align:start position:0% + + + + align:start position:0% + +and this derivative is really easy it's + + align:start position:0% +and this derivative is really easy it's + + + align:start position:0% +and this derivative is really easy it's +just a partial with temperature of this + + align:start position:0% +just a partial with temperature of this + + + align:start position:0% +just a partial with temperature of this +thing + + align:start position:0% +thing + + + align:start position:0% +thing +and uh we have minus r + + align:start position:0% +and uh we have minus r + + + align:start position:0% +and uh we have minus r +l m x of I and this is everywhere + + align:start position:0% +l m x of I and this is everywhere + + + align:start position:0% +l m x of I and this is everywhere +positive that's good so entropy of + + align:start position:0% +positive that's good so entropy of + + + align:start position:0% +positive that's good so entropy of +mixing is positive + + align:start position:0% +mixing is positive + + + align:start position:0% +mixing is positive +another thing which we have the partial + + align:start position:0% +another thing which we have the partial + + + align:start position:0% +another thing which we have the partial +molar volume of mixing + + align:start position:0% +molar volume of mixing + + + align:start position:0% +molar volume of mixing +and again we get this from the combined + + align:start position:0% +and again we get this from the combined + + + align:start position:0% +and again we get this from the combined +statement going back to chapter 4 in the + + align:start position:0% +statement going back to chapter 4 in the + + + align:start position:0% +statement going back to chapter 4 in the +text + + align:start position:0% + + + + align:start position:0% + +and um + + align:start position:0% +and um + + + align:start position:0% +and um +there's no pressure dependence here + + align:start position:0% +there's no pressure dependence here + + + align:start position:0% +there's no pressure dependence here +right there's no pressure dependence + + align:start position:0% + + + + align:start position:0% + +in this model so + + align:start position:0% +in this model so + + + align:start position:0% +in this model so +there's no volume of mixing that's good + + align:start position:0% +there's no volume of mixing that's good + + + align:start position:0% +there's no volume of mixing that's good +that's what we expected + + align:start position:0% +that's what we expected + + + align:start position:0% +that's what we expected +what about the enthalpy of mixing + + align:start position:0% +what about the enthalpy of mixing + + + align:start position:0% +what about the enthalpy of mixing +this is Delta Mu of I minus t + + align:start position:0% +this is Delta Mu of I minus t + + + align:start position:0% +this is Delta Mu of I minus t +Delta s of I + + align:start position:0% +Delta s of I + + + align:start position:0% +Delta s of I +going way back to the definition of our + + align:start position:0% +going way back to the definition of our + + + align:start position:0% +going way back to the definition of our +potentials and if you + + align:start position:0% +potentials and if you + + + align:start position:0% +potentials and if you +um write this out you see that zero + + align:start position:0% +um write this out you see that zero + + + align:start position:0% +um write this out you see that zero +and likewise the partial molar energy of + + align:start position:0% +and likewise the partial molar energy of + + + align:start position:0% +and likewise the partial molar energy of +mixing + + align:start position:0% +mixing + + + align:start position:0% +mixing +equals the partial molar enthalpy of + + align:start position:0% +equals the partial molar enthalpy of + + + align:start position:0% +equals the partial molar enthalpy of +mixing + + align:start position:0% +mixing + + + align:start position:0% +mixing +minus p and the partial molar volume of + + align:start position:0% +minus p and the partial molar volume of + + + align:start position:0% +minus p and the partial molar volume of +mixing and that's also zero + + align:start position:0% +mixing and that's also zero + + + align:start position:0% +mixing and that's also zero +so this is simply using the stuff which + + align:start position:0% +so this is simply using the stuff which + + + align:start position:0% +so this is simply using the stuff which +we did a couple of weeks ago + + align:start position:0% +we did a couple of weeks ago + + + align:start position:0% +we did a couple of weeks ago +definitions of these potentials + + align:start position:0% +definitions of these potentials + + + align:start position:0% +definitions of these potentials +and the combined statement of the first + + align:start position:0% +and the combined statement of the first + + + align:start position:0% +and the combined statement of the first +and second law and applying those + + align:start position:0% +and second law and applying those + + + align:start position:0% +and second law and applying those +operations to these quantities of mixing + + align:start position:0% +operations to these quantities of mixing + + + align:start position:0% +operations to these quantities of mixing +and I encourage you to work through + + align:start position:0% +and I encourage you to work through + + + align:start position:0% +and I encourage you to work through +these on your own and so the results + + align:start position:0% +these on your own and so the results + + + align:start position:0% +these on your own and so the results +here are are what we want that's what we + + align:start position:0% +here are are what we want that's what we + + + align:start position:0% +here are are what we want that's what we +want to see what the entropy increases + + align:start position:0% +want to see what the entropy increases + + + align:start position:0% +want to see what the entropy increases +on mixing so this is a process + + align:start position:0% +on mixing so this is a process + + + align:start position:0% +on mixing so this is a process +driven + + align:start position:0% + + + + align:start position:0% + +by entropy increase + + align:start position:0% + + + + align:start position:0% + +which is um you know we postulated that + + align:start position:0% +which is um you know we postulated that + + + align:start position:0% +which is um you know we postulated that +back in lecture one with the baby book + + align:start position:0% +back in lecture one with the baby book + + + align:start position:0% +back in lecture one with the baby book +right + + align:start position:0% +right + + + align:start position:0% +right +there is no volume + + align:start position:0% + + + + align:start position:0% + +of mixing + + align:start position:0% +of mixing + + + align:start position:0% +of mixing +for ideal Solutions + + align:start position:0% + + + + align:start position:0% + +the final volume + + align:start position:0% + + + + align:start position:0% + +is some + + align:start position:0% +is some + + + align:start position:0% +is some +of pure component contributions + + align:start position:0% + + + + align:start position:0% + +that's good + + align:start position:0% +that's good + + + align:start position:0% +that's good +and + + align:start position:0% +and + + + align:start position:0% +and +there are no interactions + + align:start position:0% +there are no interactions + + + align:start position:0% +there are no interactions +between molecules + + align:start position:0% +between molecules + + + align:start position:0% +between molecules +right that was a + + align:start position:0% +right that was a + + + align:start position:0% +right that was a +that was the foundation of the ideal gas + + align:start position:0% +that was the foundation of the ideal gas + + + align:start position:0% +that was the foundation of the ideal gas +molecule right + + align:start position:0% +molecule right + + + align:start position:0% +molecule right +no bonds + + align:start position:0% +no bonds + + + align:start position:0% +no bonds +made + + align:start position:0% +made + + + align:start position:0% +made +or broken + + align:start position:0% +or broken + + + align:start position:0% +or broken +by the mixing process + + align:start position:0% +by the mixing process + + + align:start position:0% +by the mixing process +no change + + align:start position:0% + + + + align:start position:0% + +in enthalpy + + align:start position:0% + + + + align:start position:0% + +or energy + + align:start position:0% + + + + align:start position:0% + +so what we're seeing here is again what + + align:start position:0% +so what we're seeing here is again what + + + align:start position:0% +so what we're seeing here is again what +what we intuitively have have known now + + align:start position:0% +what we intuitively have have known now + + + align:start position:0% +what we intuitively have have known now +for weeks + + align:start position:0% +for weeks + + + align:start position:0% +for weeks +we're just seeing it in this + + align:start position:0% +we're just seeing it in this + + + align:start position:0% +we're just seeing it in this +formalism okay so this is the ideal + + align:start position:0% +formalism okay so this is the ideal + + + align:start position:0% +formalism okay so this is the ideal +solution model great let's move on + + align:start position:0% +solution model great let's move on + + + align:start position:0% +solution model great let's move on +I have a quick question sorry is there a + + align:start position:0% +I have a quick question sorry is there a + + + align:start position:0% +I have a quick question sorry is there a +reason why we write the bar for entropy + + align:start position:0% +reason why we write the bar for entropy + + + align:start position:0% +reason why we write the bar for entropy +enthalpy Etc but then we don't write the + + align:start position:0% +enthalpy Etc but then we don't write the + + + align:start position:0% +enthalpy Etc but then we don't write the +bar for the Muse for the the chemical + + align:start position:0% +bar for the Muse for the the chemical + + + align:start position:0% +bar for the Muse for the the chemical +potential + + align:start position:0% +potential + + + align:start position:0% +potential +uh + + align:start position:0% + + + + align:start position:0% + +yeah gives a special and the reason + + align:start position:0% +yeah gives a special and the reason + + + align:start position:0% +yeah gives a special and the reason +um the chemical potential is the partial + + align:start position:0% +um the chemical potential is the partial + + + align:start position:0% +um the chemical potential is the partial +molar gives free energy + + align:start position:0% +molar gives free energy + + + align:start position:0% +molar gives free energy +we don't have a special term for partial + + align:start position:0% +we don't have a special term for partial + + + align:start position:0% +we don't have a special term for partial +molar entropy partial molar volume + + align:start position:0% +molar entropy partial molar volume + + + align:start position:0% +molar entropy partial molar volume +partial molar H and partial molar U + + align:start position:0% +partial molar H and partial molar U + + + align:start position:0% +partial molar H and partial molar U +it's just historically there's not I + + align:start position:0% +it's just historically there's not I + + + align:start position:0% +it's just historically there's not I +mean you could imagine coming up with + + align:start position:0% +mean you could imagine coming up with + + + align:start position:0% +mean you could imagine coming up with +new words and using different Greek + + align:start position:0% +new words and using different Greek + + + align:start position:0% +new words and using different Greek +letters + + align:start position:0% +letters + + + align:start position:0% +letters +um but Gibbs is so important that the + + align:start position:0% +um but Gibbs is so important that the + + + align:start position:0% +um but Gibbs is so important that the +partial molar gives free energy has been + + align:start position:0% +partial molar gives free energy has been + + + align:start position:0% +partial molar gives free energy has been +named chemical potential and so it's + + align:start position:0% +named chemical potential and so it's + + + align:start position:0% +named chemical potential and so it's +special + + align:start position:0% +special + + + align:start position:0% +special +good question okay thank you yeah gives + + align:start position:0% +good question okay thank you yeah gives + + + align:start position:0% +good question okay thank you yeah gives +a special + + align:start position:0% + + + + align:start position:0% + +all right so what happens + + align:start position:0% + + + + align:start position:0% + +if the molecules + + align:start position:0% + + + + align:start position:0% + +do interact + + align:start position:0% + + + + align:start position:0% + +what happens if we're not mixing ideal + + align:start position:0% +what happens if we're not mixing ideal + + + align:start position:0% +what happens if we're not mixing ideal +gases + + align:start position:0% +gases + + + align:start position:0% +gases +right + + align:start position:0% + + + + align:start position:0% + +well we want to capture + + align:start position:0% + + + + align:start position:0% + +the deviation + + align:start position:0% + + + + align:start position:0% + +we want to capture the deviation from + + align:start position:0% +we want to capture the deviation from + + + align:start position:0% +we want to capture the deviation from +the ideal model + + align:start position:0% +the ideal model + + + align:start position:0% +the ideal model +and what you're about to see is a very + + align:start position:0% +and what you're about to see is a very + + + align:start position:0% +and what you're about to see is a very +um familiar thermo thing + + align:start position:0% +um familiar thermo thing + + + align:start position:0% +um familiar thermo thing +which is more bookkeeping + + align:start position:0% + + + + align:start position:0% + +your pattern recognition might start + + align:start position:0% +your pattern recognition might start + + + align:start position:0% +your pattern recognition might start +kicking in soon that this is a thermal + + align:start position:0% +kicking in soon that this is a thermal + + + align:start position:0% +kicking in soon that this is a thermal +thing this is what thermodynamics does + + align:start position:0% +thing this is what thermodynamics does + + + align:start position:0% +thing this is what thermodynamics does +we let + + align:start position:0% +we let + + + align:start position:0% +we let +Delta Mu + + align:start position:0% + + + + align:start position:0% + +equals RT + + align:start position:0% +equals RT + + + align:start position:0% +equals RT +log of a of I + + align:start position:0% +log of a of I + + + align:start position:0% +log of a of I +I'm going to introduce that in a second + + align:start position:0% +I'm going to introduce that in a second + + + align:start position:0% +I'm going to introduce that in a second +equals RT log gamma of i x of I and just + + align:start position:0% +equals RT log gamma of i x of I and just + + + align:start position:0% +equals RT log gamma of i x of I and just +bear with me these are just definitions + + align:start position:0% +bear with me these are just definitions + + + align:start position:0% +bear with me these are just definitions +a i is being defined as the activity + + align:start position:0% + + + + align:start position:0% + +of component + + align:start position:0% + + + + align:start position:0% + +all right and it's further defined by + + align:start position:0% +all right and it's further defined by + + + align:start position:0% +all right and it's further defined by +this product of gamma of I and X of I + + align:start position:0% +this product of gamma of I and X of I + + + align:start position:0% +this product of gamma of I and X of I +and Gamma of I is known as the activity + + align:start position:0% +and Gamma of I is known as the activity + + + align:start position:0% +and Gamma of I is known as the activity +coefficient + + align:start position:0% + + + + align:start position:0% + +of component I + + align:start position:0% + + + + align:start position:0% + +and why do they do this to us right what + + align:start position:0% +and why do they do this to us right what + + + align:start position:0% +and why do they do this to us right what +is with all these terms + + align:start position:0% +is with all these terms + + + align:start position:0% +is with all these terms +if we rewrite Delta G of mixing in terms + + align:start position:0% +if we rewrite Delta G of mixing in terms + + + align:start position:0% +if we rewrite Delta G of mixing in terms +of these activities and activity + + align:start position:0% +of these activities and activity + + + align:start position:0% +of these activities and activity +coefficients let me just + + align:start position:0% +coefficients let me just + + + align:start position:0% +coefficients let me just +pull what we know to be the case this is + + align:start position:0% +pull what we know to be the case this is + + + align:start position:0% +pull what we know to be the case this is +X of I + + align:start position:0% +X of I + + + align:start position:0% +X of I +Delta Mu of I + + align:start position:0% +Delta Mu of I + + + align:start position:0% +Delta Mu of I +equals + + align:start position:0% +equals + + + align:start position:0% +equals +product by X of I RT + + align:start position:0% +product by X of I RT + + + align:start position:0% +product by X of I RT +log gamma by X of I and we're going to + + align:start position:0% +log gamma by X of I and we're going to + + + align:start position:0% +log gamma by X of I and we're going to +use the property of the log function and + + align:start position:0% +use the property of the log function and + + + align:start position:0% +use the property of the log function and +we're going to see that this + + align:start position:0% +we're going to see that this + + + align:start position:0% +we're going to see that this +turns into + + align:start position:0% +turns into + + + align:start position:0% +turns into +X of i r t log X of I Plus + + align:start position:0% +X of i r t log X of I Plus + + + align:start position:0% +X of i r t log X of I Plus +X of I RT log gamma via so the reason + + align:start position:0% +X of I RT log gamma via so the reason + + + align:start position:0% +X of I RT log gamma via so the reason +why they do this to us is because when + + align:start position:0% +why they do this to us is because when + + + align:start position:0% +why they do this to us is because when +we model + + align:start position:0% + + + + align:start position:0% + +Solutions in this particular way + + align:start position:0% +Solutions in this particular way + + + align:start position:0% +Solutions in this particular way +we have this neat separation between + + align:start position:0% +we have this neat separation between + + + align:start position:0% +we have this neat separation between +the uh ideal case + + align:start position:0% +the uh ideal case + + + align:start position:0% +the uh ideal case +and deviations from ideal + + align:start position:0% + + + + align:start position:0% + +deviation + + align:start position:0% +deviation + + + align:start position:0% +deviation +for my deal + + align:start position:0% +for my deal + + + align:start position:0% +for my deal +and we can see that + + align:start position:0% +and we can see that + + + align:start position:0% +and we can see that +non ideal + + align:start position:0% + + + + align:start position:0% + +Behavior + + align:start position:0% +Behavior + + + align:start position:0% +Behavior +is captured + + align:start position:0% + + + + align:start position:0% + +by gamma of I + + align:start position:0% +by gamma of I + + + align:start position:0% +by gamma of I +not equal + + align:start position:0% +not equal + + + align:start position:0% +not equal +to one + + align:start position:0% +to one + + + align:start position:0% +to one +so if you have ideal Solutions ideal + + align:start position:0% +so if you have ideal Solutions ideal + + + align:start position:0% +so if you have ideal Solutions ideal +Behavior + + align:start position:0% +Behavior + + + align:start position:0% +Behavior +the activity coefficients of all the + + align:start position:0% +the activity coefficients of all the + + + align:start position:0% +the activity coefficients of all the +components is one and this thing which + + align:start position:0% +components is one and this thing which + + + align:start position:0% +components is one and this thing which +we called activity is just equal to the + + align:start position:0% +we called activity is just equal to the + + + align:start position:0% +we called activity is just equal to the +mole fraction + + align:start position:0% + + + + align:start position:0% + +and if the solution does not behave + + align:start position:0% +and if the solution does not behave + + + align:start position:0% +and if the solution does not behave +ideally if it deviates + + align:start position:0% +ideally if it deviates + + + align:start position:0% +ideally if it deviates +we just dump that deviation into this + + align:start position:0% +we just dump that deviation into this + + + align:start position:0% +we just dump that deviation into this +term over here + + align:start position:0% +term over here + + + align:start position:0% +term over here +and we say it's captured by these + + align:start position:0% +and we say it's captured by these + + + align:start position:0% +and we say it's captured by these +activity coefficients being left not + + align:start position:0% +activity coefficients being left not + + + align:start position:0% +activity coefficients being left not +equal to one + + align:start position:0% +equal to one + + + align:start position:0% +equal to one +and uh we can figure out what they are + + align:start position:0% +and uh we can figure out what they are + + + align:start position:0% +and uh we can figure out what they are +later right so + + align:start position:0% +later right so + + + align:start position:0% +later right so +um again uh just a bookkeeping exercise + + align:start position:0% +um again uh just a bookkeeping exercise + + + align:start position:0% +um again uh just a bookkeeping exercise +at this point + + align:start position:0% +at this point + + + align:start position:0% +at this point +and also introducing essential terms now + + align:start position:0% +and also introducing essential terms now + + + align:start position:0% +and also introducing essential terms now +this um this activity + + align:start position:0% +this um this activity + + + align:start position:0% +this um this activity +uh if you're in course 10 + + align:start position:0% +uh if you're in course 10 + + + align:start position:0% +uh if you're in course 10 +this is equal to fugacity + + align:start position:0% + + + + align:start position:0% + +I mean that's not exactly true for gas + + align:start position:0% +I mean that's not exactly true for gas + + + align:start position:0% +I mean that's not exactly true for gas +City sort of activity in certain cases + + align:start position:0% +City sort of activity in certain cases + + + align:start position:0% +City sort of activity in certain cases +but anyway + + align:start position:0% +but anyway + + + align:start position:0% +but anyway +um + + align:start position:0% + + + + align:start position:0% + +if you've heard that term fugacity or + + align:start position:0% +if you've heard that term fugacity or + + + align:start position:0% +if you've heard that term fugacity or +you wondered what it was when you were + + align:start position:0% +you wondered what it was when you were + + + align:start position:0% +you wondered what it was when you were +reading the the Denby book um here + + align:start position:0% +reading the the Denby book um here + + + align:start position:0% +reading the the Denby book um here +effectively we have it it's the activity + + align:start position:0% +effectively we have it it's the activity + + + align:start position:0% +effectively we have it it's the activity +and um right okay so we now have this + + align:start position:0% +and um right okay so we now have this + + + align:start position:0% +and um right okay so we now have this +mathematical framework + + align:start position:0% +mathematical framework + + + align:start position:0% +mathematical framework +to capture non-ideal behavior and so + + align:start position:0% +to capture non-ideal behavior and so + + + align:start position:0% +to capture non-ideal behavior and so +what we're going to do next is + + align:start position:0% +what we're going to do next is + + + align:start position:0% +what we're going to do next is +introduce two solution models + + align:start position:0% +introduce two solution models + + + align:start position:0% +introduce two solution models +um + + align:start position:0% +um + + + align:start position:0% +um +for non-ideal Solutions + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +the first one is going to be + + align:start position:0% +the first one is going to be + + + align:start position:0% +the first one is going to be +the dilute + + align:start position:0% +the dilute + + + align:start position:0% +the dilute +solution model + + align:start position:0% + + + + align:start position:0% + +okay so this is the dilute model + + align:start position:0% +okay so this is the dilute model + + + align:start position:0% +okay so this is the dilute model +it's based on some physical reasoning + + align:start position:0% +it's based on some physical reasoning + + + align:start position:0% +it's based on some physical reasoning +which is always a relief + + align:start position:0% +which is always a relief + + + align:start position:0% +which is always a relief +after all this math + + align:start position:0% +after all this math + + + align:start position:0% +after all this math +so we have + + align:start position:0% +so we have + + + align:start position:0% +so we have +solvent + + align:start position:0% +solvent + + + align:start position:0% +solvent +and solute + + align:start position:0% + + + + align:start position:0% + +okay so + + align:start position:0% +okay so + + + align:start position:0% +okay so +um what does dilute mean right not + + align:start position:0% +um what does dilute mean right not + + + align:start position:0% +um what does dilute mean right not +concentrated so these are the + + align:start position:0% +concentrated so these are the + + + align:start position:0% +concentrated so these are the +assumptions + + align:start position:0% + + + + align:start position:0% + +we're going to make two assumptions + + align:start position:0% +we're going to make two assumptions + + + align:start position:0% +we're going to make two assumptions +about these physical systems one + + align:start position:0% +about these physical systems one + + + align:start position:0% +about these physical systems one +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +each solute molecule + + align:start position:0% + + + + align:start position:0% + +is surrounded + + align:start position:0% + + + + align:start position:0% + +by solvent + + align:start position:0% + + + + align:start position:0% + +and solute + + align:start position:0% +and solute + + + align:start position:0% +and solute +solute + + align:start position:0% +solute + + + align:start position:0% +solute +interactions + + align:start position:0% + + + + align:start position:0% + +are negligible + + align:start position:0% + + + + align:start position:0% + +um so this has physical implications + + align:start position:0% +um so this has physical implications + + + align:start position:0% +um so this has physical implications +this is like + + align:start position:0% +this is like + + + align:start position:0% +this is like +um someone drops you in the middle of + + align:start position:0% +um someone drops you in the middle of + + + align:start position:0% +um someone drops you in the middle of +the woods very very very far + + align:start position:0% +the woods very very very far + + + align:start position:0% +the woods very very very far +uh from civilization + + align:start position:0% +uh from civilization + + + align:start position:0% +uh from civilization +and and you start acting the way you do + + align:start position:0% +and and you start acting the way you do + + + align:start position:0% +and and you start acting the way you do +when there's no one else around and + + align:start position:0% +when there's no one else around and + + + align:start position:0% +when there's no one else around and +there's not a chance of you running into + + align:start position:0% +there's not a chance of you running into + + + align:start position:0% +there's not a chance of you running into +somebody and however you act that's up + + align:start position:0% +somebody and however you act that's up + + + align:start position:0% +somebody and however you act that's up +to you but this is the point you are + + align:start position:0% +to you but this is the point you are + + + align:start position:0% +to you but this is the point you are +acting as if there's not another soul + + align:start position:0% +acting as if there's not another soul + + + align:start position:0% +acting as if there's not another soul +on Earth + + align:start position:0% +on Earth + + + align:start position:0% +on Earth +right you're in the middle of the woods + + align:start position:0% +right you're in the middle of the woods + + + align:start position:0% +right you're in the middle of the woods +and now let's say that somebody else + + align:start position:0% +and now let's say that somebody else + + + align:start position:0% +and now let's say that somebody else +gets dropped into the same Woods 10 + + align:start position:0% +gets dropped into the same Woods 10 + + + align:start position:0% +gets dropped into the same Woods 10 +miles away + + align:start position:0% +miles away + + + align:start position:0% +miles away +all right that person will also act as + + align:start position:0% +all right that person will also act as + + + align:start position:0% +all right that person will also act as +if there's not another soul on Earth + + align:start position:0% +if there's not another soul on Earth + + + align:start position:0% +if there's not another soul on Earth +however they act + + align:start position:0% +however they act + + + align:start position:0% +however they act +and + + align:start position:0% +and + + + align:start position:0% +and +if we populate the woods in this very + + align:start position:0% +if we populate the woods in this very + + + align:start position:0% +if we populate the woods in this very +dilute way where there's not anybody you + + align:start position:0% +dilute way where there's not anybody you + + + align:start position:0% +dilute way where there's not anybody you +know within miles and miles and miles of + + align:start position:0% +know within miles and miles and miles of + + + align:start position:0% +know within miles and miles and miles of +each other + + align:start position:0% +each other + + + align:start position:0% +each other +then each individual person will act as + + align:start position:0% +then each individual person will act as + + + align:start position:0% +then each individual person will act as +if they're the only person in those + + align:start position:0% +if they're the only person in those + + + align:start position:0% +if they're the only person in those +woods + + align:start position:0% +woods + + + align:start position:0% +woods +until we get to a point when they start + + align:start position:0% +until we get to a point when they start + + + align:start position:0% +until we get to a point when they start +becoming aware of each other + + align:start position:0% +becoming aware of each other + + + align:start position:0% +becoming aware of each other +right and just as you might if it's for + + align:start position:0% +right and just as you might if it's for + + + align:start position:0% +right and just as you might if it's for +you in the woods if you started becoming + + align:start position:0% +you in the woods if you started becoming + + + align:start position:0% +you in the woods if you started becoming +aware of somebody else where before you + + align:start position:0% +aware of somebody else where before you + + + align:start position:0% +aware of somebody else where before you +didn't think there would be anyone else + + align:start position:0% +didn't think there would be anyone else + + + align:start position:0% +didn't think there would be anyone else +your behavior might change a little bit + + align:start position:0% +your behavior might change a little bit + + + align:start position:0% +your behavior might change a little bit +it's the same with dilute Solutions + + align:start position:0% +it's the same with dilute Solutions + + + align:start position:0% +it's the same with dilute Solutions +we're in the dilute limit when each + + align:start position:0% +we're in the dilute limit when each + + + align:start position:0% +we're in the dilute limit when each +solute is acting as if it's the only one + + align:start position:0% +solute is acting as if it's the only one + + + align:start position:0% +solute is acting as if it's the only one +completely surrounded by solvent and all + + align:start position:0% +completely surrounded by solvent and all + + + align:start position:0% +completely surrounded by solvent and all +of its thermodynamics are dominated by + + align:start position:0% +of its thermodynamics are dominated by + + + align:start position:0% +of its thermodynamics are dominated by +solute solvent interactions so that's + + align:start position:0% +solute solvent interactions so that's + + + align:start position:0% +solute solvent interactions so that's +the first assumption the second + + align:start position:0% +the first assumption the second + + + align:start position:0% +the first assumption the second +assumption is that + + align:start position:0% +assumption is that + + + align:start position:0% +assumption is that +each + + align:start position:0% +each + + + align:start position:0% +each +solvent + + align:start position:0% +solvent + + + align:start position:0% +solvent +molecule + + align:start position:0% + + + + align:start position:0% + +on average + + align:start position:0% + + + + align:start position:0% + +on average + + align:start position:0% + + + + align:start position:0% + +is surrounded + + align:start position:0% + + + + align:start position:0% + +by pure solvent + + align:start position:0% + + + + align:start position:0% + +and therefore + + align:start position:0% + + + + align:start position:0% + +Act + + align:start position:0% + + + + align:start position:0% + +like + + align:start position:0% +like + + + align:start position:0% +like +a pure substance + + align:start position:0% + + + + align:start position:0% + +so this is a little bit harder to + + align:start position:0% +so this is a little bit harder to + + + align:start position:0% +so this is a little bit harder to +justify + + align:start position:0% +justify + + + align:start position:0% +justify +and actually on the pset we ask you to + + align:start position:0% +and actually on the pset we ask you to + + + align:start position:0% +and actually on the pset we ask you to +uh take this and justify this + + align:start position:0% + + + + align:start position:0% + +we don't put it that way we'll we'll + + align:start position:0% +we don't put it that way we'll we'll + + + align:start position:0% +we don't put it that way we'll we'll +cover that in you know three minutes but + + align:start position:0% +cover that in you know three minutes but + + + align:start position:0% +cover that in you know three minutes but +effectively what you're you're asked to + + align:start position:0% +effectively what you're you're asked to + + + align:start position:0% +effectively what you're you're asked to +show on the pizza is that given this + + align:start position:0% +show on the pizza is that given this + + + align:start position:0% +show on the pizza is that given this +this follows + + align:start position:0% +this follows + + + align:start position:0% +this follows +um so yeah there's some solvent + + align:start position:0% +um so yeah there's some solvent + + + align:start position:0% +um so yeah there's some solvent +molecules here that are near solute and + + align:start position:0% +molecules here that are near solute and + + + align:start position:0% +molecules here that are near solute and +yeah they know that they're soluble but + + align:start position:0% +yeah they know that they're soluble but + + + align:start position:0% +yeah they know that they're soluble but +if you averaged over all the solvent + + align:start position:0% +if you averaged over all the solvent + + + align:start position:0% +if you averaged over all the solvent +molecules the average solvent molecule + + align:start position:0% +molecules the average solvent molecule + + + align:start position:0% +molecules the average solvent molecule +is surrounded also by only solvent + + align:start position:0% +is surrounded also by only solvent + + + align:start position:0% +is surrounded also by only solvent +molecules so these are the physical + + align:start position:0% +molecules so these are the physical + + + align:start position:0% +molecules so these are the physical +assumptions + + align:start position:0% +assumptions + + + align:start position:0% +assumptions +and um so here the mathematical + + align:start position:0% +and um so here the mathematical + + + align:start position:0% +and um so here the mathematical +implications of that so assumption + + align:start position:0% +implications of that so assumption + + + align:start position:0% +implications of that so assumption +number one + + align:start position:0% + + + + align:start position:0% + +leads to + + align:start position:0% +leads to + + + align:start position:0% +leads to +something called Henry's law + + align:start position:0% + + + + align:start position:0% + +Henry's law + + align:start position:0% +Henry's law + + + align:start position:0% +Henry's law +of the solute + + align:start position:0% + + + + align:start position:0% + +and that's the following + + align:start position:0% +and that's the following + + + align:start position:0% +and that's the following +in the limit + + align:start position:0% +in the limit + + + align:start position:0% +in the limit +of mole fraction X2 going to zero + + align:start position:0% +of mole fraction X2 going to zero + + + align:start position:0% +of mole fraction X2 going to zero +so the second component here is the + + align:start position:0% +so the second component here is the + + + align:start position:0% +so the second component here is the +solute + + align:start position:0% +solute + + + align:start position:0% +solute +the activity + + align:start position:0% +the activity + + + align:start position:0% +the activity +of component two + + align:start position:0% + + + + align:start position:0% + +approaches + + align:start position:0% + + + + align:start position:0% + +this quantity + + align:start position:0% +this quantity + + + align:start position:0% +this quantity +where gamma 2 naught is called Henry's + + align:start position:0% +where gamma 2 naught is called Henry's + + + align:start position:0% +where gamma 2 naught is called Henry's +constant + + align:start position:0% + + + + align:start position:0% + +this mathematical form + + align:start position:0% + + + + align:start position:0% + +results in + + align:start position:0% +results in + + + align:start position:0% +results in +what we want which is that + + align:start position:0% +what we want which is that + + + align:start position:0% +what we want which is that +thermodynamically each additional solute + + align:start position:0% +thermodynamically each additional solute + + + align:start position:0% +thermodynamically each additional solute +molecule thinks it's the only one in the + + align:start position:0% +molecule thinks it's the only one in the + + + align:start position:0% +molecule thinks it's the only one in the +forest okay + + align:start position:0% +forest okay + + + align:start position:0% +forest okay +assumption number two + + align:start position:0% + + + + align:start position:0% + +has the following implication + + align:start position:0% +has the following implication + + + align:start position:0% +has the following implication +called + + align:start position:0% +called + + + align:start position:0% +called +Raul's law + + align:start position:0% +Raul's law + + + align:start position:0% +Raul's law +of the solvent + + align:start position:0% +of the solvent + + + align:start position:0% +of the solvent +and Raul's law of the solvent + + align:start position:0% +and Raul's law of the solvent + + + align:start position:0% +and Raul's law of the solvent +is that the limit of X1 going to one + + align:start position:0% +is that the limit of X1 going to one + + + align:start position:0% +is that the limit of X1 going to one +that is the solvent becoming + + align:start position:0% +that is the solvent becoming + + + align:start position:0% +that is the solvent becoming +increasingly concentrated the activity + + align:start position:0% +increasingly concentrated the activity + + + align:start position:0% +increasingly concentrated the activity +is simply equal to the mole fraction + + align:start position:0% +is simply equal to the mole fraction + + + align:start position:0% +is simply equal to the mole fraction +okay so these are Henry and her old I I + + align:start position:0% +okay so these are Henry and her old I I + + + align:start position:0% +okay so these are Henry and her old I I +don't know whether they were + + align:start position:0% +don't know whether they were + + + align:start position:0% +don't know whether they were +contemporaries whether they were BFFs or + + align:start position:0% +contemporaries whether they were BFFs or + + + align:start position:0% +contemporaries whether they were BFFs or +or whatnot and I have a really hard time + + align:start position:0% +or whatnot and I have a really hard time + + + align:start position:0% +or whatnot and I have a really hard time +remembering which one is which + + align:start position:0% +remembering which one is which + + + align:start position:0% +remembering which one is which +um just a note for the pset + + align:start position:0% +um just a note for the pset + + + align:start position:0% +um just a note for the pset +this can + + align:start position:0% +this can + + + align:start position:0% +this can +be derived + + align:start position:0% + + + + align:start position:0% + +from Henry + + align:start position:0% + + + + align:start position:0% + +via + + align:start position:0% +via + + + align:start position:0% +via +Gibbs do him integration + + align:start position:0% +Gibbs do him integration + + + align:start position:0% +Gibbs do him integration +which is discussed in detail + + align:start position:0% +which is discussed in detail + + + align:start position:0% +which is discussed in detail +in section + + align:start position:0% + + + + align:start position:0% + +8.2.3 okay so that's relevant for the + + align:start position:0% +8.2.3 okay so that's relevant for the + + + align:start position:0% +8.2.3 okay so that's relevant for the +preset + + align:start position:0% +preset + + + align:start position:0% +preset +[Applause] + + align:start position:0% + + + + align:start position:0% + +we're also out of the solvent and the + + align:start position:0% +we're also out of the solvent and the + + + align:start position:0% +we're also out of the solvent and the +result of the solute + + align:start position:0% + + + + align:start position:0% + +all right so let's plot how those look + + align:start position:0% + + + + align:start position:0% + +variation + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +of activity + + align:start position:0% + + + + align:start position:0% + +with composition + + align:start position:0% + + + + align:start position:0% + +it could + + align:start position:0% +it could + + + align:start position:0% +it could +look + + align:start position:0% + + + + align:start position:0% + +like this this is an example + + align:start position:0% +like this this is an example + + + align:start position:0% +like this this is an example +and I'm just going to copy + + align:start position:0% +and I'm just going to copy + + + align:start position:0% +and I'm just going to copy +this figure from the Hoff + + align:start position:0% +this figure from the Hoff + + + align:start position:0% +this figure from the Hoff +figure 8.4 because I think it's useful + + align:start position:0% +figure 8.4 because I think it's useful + + + align:start position:0% +figure 8.4 because I think it's useful +so I'm about to copy here + + align:start position:0% +so I'm about to copy here + + + align:start position:0% +so I'm about to copy here +all right so it could look like this + + align:start position:0% + + + + align:start position:0% + +what I'm trying to plot here + + align:start position:0% +what I'm trying to plot here + + + align:start position:0% +what I'm trying to plot here +is as a function of X of 2 + + align:start position:0% +is as a function of X of 2 + + + align:start position:0% +is as a function of X of 2 +the activity of the first component and + + align:start position:0% +the activity of the first component and + + + align:start position:0% +the activity of the first component and +the activity of the second line so this + + align:start position:0% +the activity of the second line so this + + + align:start position:0% +the activity of the second line so this +goes between zero and one this goes + + align:start position:0% +goes between zero and one this goes + + + align:start position:0% +goes between zero and one this goes +between zero and one + + align:start position:0% +between zero and one + + + align:start position:0% +between zero and one +this on this plot goes between zero and + + align:start position:0% +this on this plot goes between zero and + + + align:start position:0% +this on this plot goes between zero and +one it doesn't have to you can have two + + align:start position:0% +one it doesn't have to you can have two + + + align:start position:0% +one it doesn't have to you can have two +you can have activities greater than one + + align:start position:0% +you can have activities greater than one + + + align:start position:0% +you can have activities greater than one +but we're going to keep it simple here + + align:start position:0% +but we're going to keep it simple here + + + align:start position:0% +but we're going to keep it simple here +and so um the ideal solution model + + align:start position:0% + + + + align:start position:0% + +is that those are the ideal model + + align:start position:0% +is that those are the ideal model + + + align:start position:0% +is that those are the ideal model +slope + + align:start position:0% +slope + + + align:start position:0% +slope +minus one + + align:start position:0% + + + + align:start position:0% + +ideal + + align:start position:0% +ideal + + + align:start position:0% +ideal +slope + + align:start position:0% + + + + align:start position:0% + +one + + align:start position:0% +one + + + align:start position:0% +one +ideal so the ideal solution model + + align:start position:0% +ideal so the ideal solution model + + + align:start position:0% +ideal so the ideal solution model +is um is like that + + align:start position:0% + + + + align:start position:0% + +Henry's law here + + align:start position:0% + + + + align:start position:0% + +is going to have a slope not equal to + + align:start position:0% +is going to have a slope not equal to + + + align:start position:0% +is going to have a slope not equal to +one + + align:start position:0% +one + + + align:start position:0% +one +so this is a slope + + align:start position:0% + + + + align:start position:0% + +of gamma one naught Henry + + align:start position:0% + + + + align:start position:0% + +and similarly we can have + + align:start position:0% +and similarly we can have + + + align:start position:0% +and similarly we can have +some slope + + align:start position:0% + + + + align:start position:0% + +gamma 2 naught and this is Henry + + align:start position:0% + + + + align:start position:0% + +that's Henry and the reality could be + + align:start position:0% +that's Henry and the reality could be + + + align:start position:0% +that's Henry and the reality could be +something like this + + align:start position:0% + + + + align:start position:0% + +when X2 + + align:start position:0% +when X2 + + + align:start position:0% +when X2 +is concentrated X1 is + + align:start position:0% +is concentrated X1 is + + + align:start position:0% +is concentrated X1 is +dilute + + align:start position:0% +dilute + + + align:start position:0% +dilute +and you start up Henry's law there and + + align:start position:0% +and you start up Henry's law there and + + + align:start position:0% +and you start up Henry's law there and +then it deviates and at some point you + + align:start position:0% +then it deviates and at some point you + + + align:start position:0% +then it deviates and at some point you +asymptote + + align:start position:0% +asymptote + + + align:start position:0% +asymptote +to Rule's law so this is this might this + + align:start position:0% +to Rule's law so this is this might this + + + align:start position:0% +to Rule's law so this is this might this +might be reality right there's lots of + + align:start position:0% +might be reality right there's lots of + + + align:start position:0% +might be reality right there's lots of +different ways that this can shake out + + align:start position:0% +different ways that this can shake out + + + align:start position:0% +different ways that this can shake out +but as drawn here and again you have + + align:start position:0% +but as drawn here and again you have + + + align:start position:0% +but as drawn here and again you have +for dilute X2 you start along Henry and + + align:start position:0% +for dilute X2 you start along Henry and + + + align:start position:0% +for dilute X2 you start along Henry and +then you at some point asymptote two + + align:start position:0% +then you at some point asymptote two + + + align:start position:0% +then you at some point asymptote two +Rebels + + align:start position:0% +Rebels + + + align:start position:0% +Rebels +so um + + align:start position:0% +so um + + + align:start position:0% +so um +this this could be what you get + + align:start position:0% +this this could be what you get + + + align:start position:0% +this this could be what you get +all right Rhodes law Henry's law Henry's + + align:start position:0% +all right Rhodes law Henry's law Henry's + + + align:start position:0% +all right Rhodes law Henry's law Henry's +law rules and one implies the other + + align:start position:0% + + + + align:start position:0% + +all right so that's dilute Solutions and + + align:start position:0% +all right so that's dilute Solutions and + + + align:start position:0% +all right so that's dilute Solutions and +um + + align:start position:0% +um + + + align:start position:0% +um +I ask you one problem on Data Solutions + + align:start position:0% +I ask you one problem on Data Solutions + + + align:start position:0% +I ask you one problem on Data Solutions +on the PSAT we're not going to spend a + + align:start position:0% +on the PSAT we're not going to spend a + + + align:start position:0% +on the PSAT we're not going to spend a +lot of time on the Solutions in this + + align:start position:0% +lot of time on the Solutions in this + + + align:start position:0% +lot of time on the Solutions in this +class + + align:start position:0% +class + + + align:start position:0% +class +the reason why we took this time these + + align:start position:0% +the reason why we took this time these + + + align:start position:0% +the reason why we took this time these +15 minutes of lecture and a little bit + + align:start position:0% +15 minutes of lecture and a little bit + + + align:start position:0% +15 minutes of lecture and a little bit +of time on the pset is to set you up for + + align:start position:0% +of time on the pset is to set you up for + + + align:start position:0% +of time on the pset is to set you up for +those of you who are going to do aqueous + + align:start position:0% +those of you who are going to do aqueous + + + align:start position:0% +those of you who are going to do aqueous +chemistry or electrochemistry + + align:start position:0% +chemistry or electrochemistry + + + align:start position:0% +chemistry or electrochemistry +um you you'll want to know this so + + align:start position:0% +um you you'll want to know this so + + + align:start position:0% +um you you'll want to know this so +that's that's why we did that + + align:start position:0% +that's that's why we did that + + + align:start position:0% +that's that's why we did that +um there is another type of solution to + + align:start position:0% +um there is another type of solution to + + + align:start position:0% +um there is another type of solution to +modeling which is much more useful for + + align:start position:0% +modeling which is much more useful for + + + align:start position:0% +modeling which is much more useful for +o2o + + align:start position:0% +o2o + + + align:start position:0% +o2o +and those are called regular solution + + align:start position:0% +and those are called regular solution + + + align:start position:0% +and those are called regular solution +models + + align:start position:0% +models + + + align:start position:0% +models +so these are models + + align:start position:0% +so these are models + + + align:start position:0% +so these are models +that we're going to spend the next + + align:start position:0% +that we're going to spend the next + + + align:start position:0% +that we're going to spend the next +couple lectures on at least the lectures + + align:start position:0% +couple lectures on at least the lectures + + + align:start position:0% +couple lectures on at least the lectures +that are new material + + align:start position:0% +that are new material + + + align:start position:0% +that are new material +and you spend more time on the PSAT Zone + + align:start position:0% +and you spend more time on the PSAT Zone + + + align:start position:0% +and you spend more time on the PSAT Zone +so regular solicitor models are like + + align:start position:0% +so regular solicitor models are like + + + align:start position:0% +so regular solicitor models are like +this we also start with some physical + + align:start position:0% +this we also start with some physical + + + align:start position:0% +this we also start with some physical +assumptions and then we develop the + + align:start position:0% +assumptions and then we develop the + + + align:start position:0% +assumptions and then we develop the +implications of that one + + align:start position:0% +implications of that one + + + align:start position:0% +implications of that one +the entropy of mixing + + align:start position:0% + + + + align:start position:0% + +the entropy of mixing + + align:start position:0% + + + + align:start position:0% + +is captured + + align:start position:0% + + + + align:start position:0% + +by the ideal model + + align:start position:0% + + + + align:start position:0% + +Delta s mix + + align:start position:0% +Delta s mix + + + align:start position:0% +Delta s mix +ideal that sort of gets a little bit + + align:start position:0% +ideal that sort of gets a little bit + + + align:start position:0% +ideal that sort of gets a little bit +fuzzy over there I'm sorry for that + + align:start position:0% +fuzzy over there I'm sorry for that + + + align:start position:0% +fuzzy over there I'm sorry for that +okay + + align:start position:0% +okay + + + align:start position:0% +okay +okay so we're going to assume that the + + align:start position:0% +okay so we're going to assume that the + + + align:start position:0% +okay so we're going to assume that the +ideal model captures the entropy of + + align:start position:0% +ideal model captures the entropy of + + + align:start position:0% +ideal model captures the entropy of +mixing and as we'll see uh later when we + + align:start position:0% +mixing and as we'll see uh later when we + + + align:start position:0% +mixing and as we'll see uh later when we +do statistical thermodynamics we will + + align:start position:0% +do statistical thermodynamics we will + + + align:start position:0% +do statistical thermodynamics we will +show + + align:start position:0% + + + + align:start position:0% + +later + + align:start position:0% +later + + + align:start position:0% +later +that + + align:start position:0% +that + + + align:start position:0% +that +this + + align:start position:0% + + + + align:start position:0% + +is what's called configurational entropy + + align:start position:0% + + + + align:start position:0% + +configurational entropy is entropy + + align:start position:0% +configurational entropy is entropy + + + align:start position:0% +configurational entropy is entropy +associated with the spatial + + align:start position:0% +associated with the spatial + + + align:start position:0% +associated with the spatial +configuration of things + + align:start position:0% +configuration of things + + + align:start position:0% +configuration of things +and again you can recall the pictures in + + align:start position:0% +and again you can recall the pictures in + + + align:start position:0% +and again you can recall the pictures in +the baby book right mixed up in this + + align:start position:0% +the baby book right mixed up in this + + + align:start position:0% +the baby book right mixed up in this +represented by + + align:start position:0% +represented by + + + align:start position:0% +represented by +where things are in space + + align:start position:0% +where things are in space + + + align:start position:0% +where things are in space +so that's configurational activity + + align:start position:0% +so that's configurational activity + + + align:start position:0% +so that's configurational activity +that's the ideal model + + align:start position:0% +that's the ideal model + + + align:start position:0% +that's the ideal model +but we're also going to allow + + align:start position:0% +but we're also going to allow + + + align:start position:0% +but we're also going to allow +intermolecular interactions + + align:start position:0% + + + + align:start position:0% + +intermolecular interactions are + + align:start position:0% +intermolecular interactions are + + + align:start position:0% +intermolecular interactions are +uh non-zero or finite + + align:start position:0% +uh non-zero or finite + + + align:start position:0% +uh non-zero or finite +exist there we have it what that means + + align:start position:0% +exist there we have it what that means + + + align:start position:0% +exist there we have it what that means +is going to be this + + align:start position:0% +is going to be this + + + align:start position:0% +is going to be this +foreign + + align:start position:0% + + + + align:start position:0% + +so in this model when you make a mixture + + align:start position:0% +so in this model when you make a mixture + + + align:start position:0% +so in this model when you make a mixture +some bonds are made others are broken + + align:start position:0% +some bonds are made others are broken + + + align:start position:0% +some bonds are made others are broken +and there's going to be an energy cost + + align:start position:0% +and there's going to be an energy cost + + + align:start position:0% +and there's going to be an energy cost +to that so this is what we get we get + + align:start position:0% +to that so this is what we get we get + + + align:start position:0% +to that so this is what we get we get +Delta G of mixing + + align:start position:0% +Delta G of mixing + + + align:start position:0% +Delta G of mixing +equals Delta h of mixing General + + align:start position:0% +equals Delta h of mixing General + + + align:start position:0% +equals Delta h of mixing General +non-zero minus t Delta s mixing + + align:start position:0% +non-zero minus t Delta s mixing + + + align:start position:0% +non-zero minus t Delta s mixing +where this is ideal + + align:start position:0% +where this is ideal + + + align:start position:0% +where this is ideal +that's ideal + + align:start position:0% +that's ideal + + + align:start position:0% +that's ideal +and that is + + align:start position:0% + + + + align:start position:0% + +equal to the following + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so this is um what's called a regular + + align:start position:0% +so this is um what's called a regular + + + align:start position:0% +so this is um what's called a regular +solution model + + align:start position:0% +solution model + + + align:start position:0% +solution model +and I'll give you one more + + align:start position:0% +and I'll give you one more + + + align:start position:0% +and I'll give you one more +piece of information + + align:start position:0% +piece of information + + + align:start position:0% +piece of information +which is the + + align:start position:0% +which is the + + + align:start position:0% +which is the +simple + + align:start position:0% + + + + align:start position:0% + +regular + + align:start position:0% + + + + align:start position:0% + +model + + align:start position:0% + + + + align:start position:0% + +the simple regular model + + align:start position:0% +the simple regular model + + + align:start position:0% +the simple regular model +is the simplest case + + align:start position:0% + + + + align:start position:0% + +of regular solution models + + align:start position:0% + + + + align:start position:0% + +for binary systems + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +we can write it down really easily this + + align:start position:0% +we can write it down really easily this + + + align:start position:0% +we can write it down really easily this +is it Delta H mixing + + align:start position:0% +is it Delta H mixing + + + align:start position:0% +is it Delta H mixing +equals + + align:start position:0% +equals + + + align:start position:0% +equals +a naught X1 X2 + + align:start position:0% +a naught X1 X2 + + + align:start position:0% +a naught X1 X2 +so it's a model with one parameter + + align:start position:0% +so it's a model with one parameter + + + align:start position:0% +so it's a model with one parameter +it's a mixing term + + align:start position:0% + + + + align:start position:0% + +parameterized + + align:start position:0% + + + + align:start position:0% + +by a naught which typically has units of + + align:start position:0% +by a naught which typically has units of + + + align:start position:0% +by a naught which typically has units of +joule per mole + + align:start position:0% + + + + align:start position:0% + +if a naught is greater than zero this is + + align:start position:0% +if a naught is greater than zero this is + + + align:start position:0% +if a naught is greater than zero this is +an n + + align:start position:0% +an n + + + align:start position:0% +an n +endothermic mixing + + align:start position:0% + + + + align:start position:0% + +right endothermic mixing we have to put + + align:start position:0% +right endothermic mixing we have to put + + + align:start position:0% +right endothermic mixing we have to put +in heat energy + + align:start position:0% + + + + align:start position:0% + +so maybe some bonds are broken right the + + align:start position:0% +so maybe some bonds are broken right the + + + align:start position:0% +so maybe some bonds are broken right the +molecules end up in a higher energy + + align:start position:0% +molecules end up in a higher energy + + + align:start position:0% +molecules end up in a higher energy +state + + align:start position:0% +state + + + align:start position:0% +state +in uh less than zero this is exothermic + + align:start position:0% + + + + align:start position:0% + +mixing + + align:start position:0% + + + + align:start position:0% + +okay and so uh with that model for the + + align:start position:0% +okay and so uh with that model for the + + + align:start position:0% +okay and so uh with that model for the +enthalpy of mixing we have the full + + align:start position:0% +enthalpy of mixing we have the full + + + align:start position:0% +enthalpy of mixing we have the full +solution model which is a naught x 1 x 2 + + align:start position:0% +solution model which is a naught x 1 x 2 + + + align:start position:0% +solution model which is a naught x 1 x 2 +plus r t some i x by natural log + + align:start position:0% +plus r t some i x by natural log + + + align:start position:0% +plus r t some i x by natural log +X of I + + align:start position:0% +X of I + + + align:start position:0% +X of I +okay so this is the simple regular model + + align:start position:0% +okay so this is the simple regular model + + + align:start position:0% +okay so this is the simple regular model +and we're going to spend some time on + + align:start position:0% +and we're going to spend some time on + + + align:start position:0% +and we're going to spend some time on +this + + align:start position:0% +this + + + align:start position:0% +this +um you're spending some time on this on + + align:start position:0% +um you're spending some time on this on + + + align:start position:0% +um you're spending some time on this on +the pset + + align:start position:0% +the pset + + + align:start position:0% +the pset +um yeah we've got two parameters it's + + align:start position:0% +um yeah we've got two parameters it's + + + align:start position:0% +um yeah we've got two parameters it's +got enthalpy a mixing parameter and it's + + align:start position:0% +got enthalpy a mixing parameter and it's + + + align:start position:0% +got enthalpy a mixing parameter and it's +got temperature + + align:start position:0% +got temperature + + + align:start position:0% +got temperature +and from these two parameters you can + + align:start position:0% +and from these two parameters you can + + + align:start position:0% +and from these two parameters you can +generate a nice diversity of physical + + align:start position:0% +generate a nice diversity of physical + + + align:start position:0% +generate a nice diversity of physical +behavior and and we'll see that in the + + align:start position:0% +behavior and and we'll see that in the + + + align:start position:0% +behavior and and we'll see that in the +weeks ahead + + align:start position:0% +weeks ahead + + + align:start position:0% +weeks ahead +okay + + align:start position:0% +okay + + + align:start position:0% +okay +um today's lecture covered a lot of + + align:start position:0% +um today's lecture covered a lot of + + + align:start position:0% +um today's lecture covered a lot of +essential information + + align:start position:0% +essential information + + + align:start position:0% +essential information +and uh I went rather quickly so I have + + align:start position:0% +and uh I went rather quickly so I have + + + align:start position:0% +and uh I went rather quickly so I have +plenty of time for questions + + align:start position:0% +plenty of time for questions + + + align:start position:0% +plenty of time for questions +and I will keep the recording on for + + align:start position:0% +and I will keep the recording on for + + + align:start position:0% +and I will keep the recording on for +some time now + + align:start position:0% +some time now + + + align:start position:0% +some time now +and and then switch it off + + align:start position:0% +and and then switch it off + + + align:start position:0% +and and then switch it off +at at 10 55 and + + align:start position:0% +at at 10 55 and + + + align:start position:0% +at at 10 55 and +um before we start that I'll remind you + + align:start position:0% +um before we start that I'll remind you + + + align:start position:0% +um before we start that I'll remind you +my office hours have switched + + align:start position:0% +my office hours have switched + + + align:start position:0% +my office hours have switched +to Wednesday + + align:start position:0% +to Wednesday + + + align:start position:0% +to Wednesday +at 12 so that's in about an hour hour + + align:start position:0% +at 12 so that's in about an hour hour + + + align:start position:0% +at 12 so that's in about an hour hour +and 15 minutes from now + + align:start position:0% +and 15 minutes from now + + + align:start position:0% +and 15 minutes from now +officero switched to Wednesday at 12. + + align:start position:0% +officero switched to Wednesday at 12. + + + align:start position:0% +officero switched to Wednesday at 12. +and + + align:start position:0% +and + + + align:start position:0% +and +um + + align:start position:0% +um + + + align:start position:0% +um +there's a very slightly revised syllabus + + align:start position:0% +there's a very slightly revised syllabus + + + align:start position:0% +there's a very slightly revised syllabus +for Thermo + + align:start position:0% +for Thermo + + + align:start position:0% +for Thermo +none of the due dates change or anything + + align:start position:0% +none of the due dates change or anything + + + align:start position:0% +none of the due dates change or anything +like that it doesn't really change your + + align:start position:0% +like that it doesn't really change your + + + align:start position:0% +like that it doesn't really change your +life + + align:start position:0% +life + + + align:start position:0% +life +um substantially but it is a little bit + + align:start position:0% +um substantially but it is a little bit + + + align:start position:0% +um substantially but it is a little bit +of a more accurate view of where we're + + align:start position:0% +of a more accurate view of where we're + + + align:start position:0% +of a more accurate view of where we're +heading in the next couple lectures + + align:start position:0% + + + + align:start position:0% + +um the exam is Monday + + align:start position:0% +um the exam is Monday + + + align:start position:0% +um the exam is Monday +and it will cover unary phase diagrams + + align:start position:0% +and it will cover unary phase diagrams + + + align:start position:0% +and it will cover unary phase diagrams +and reacting ideal gas mixtures and the + + align:start position:0% +and reacting ideal gas mixtures and the + + + align:start position:0% +and reacting ideal gas mixtures and the +rudiments of Ideal Solutions + + align:start position:0% +rudiments of Ideal Solutions + + + align:start position:0% +rudiments of Ideal Solutions +but um none of this + + align:start position:0% +but um none of this + + + align:start position:0% +but um none of this +uh really involves solution and modeling + + align:start position:0% +uh really involves solution and modeling + + + align:start position:0% +uh really involves solution and modeling +apparatus that we're working on now + + align:start position:0% +apparatus that we're working on now + + + align:start position:0% +apparatus that we're working on now +um what that means is that the pizza + + align:start position:0% +um what that means is that the pizza + + + align:start position:0% +um what that means is that the pizza +that's due on Friday is only minimally + + align:start position:0% +that's due on Friday is only minimally + + + align:start position:0% +that's due on Friday is only minimally +covered on the exam so you can focus on + + align:start position:0% +covered on the exam so you can focus on + + + align:start position:0% +covered on the exam so you can focus on +slightly earlier material for the exam + + align:start position:0% +slightly earlier material for the exam + + + align:start position:0% +slightly earlier material for the exam +exam Monday + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +um we will get new Thermo + + align:start position:0% + + + + align:start position:0% + +next Wednesday not this Wednesday but + + align:start position:0% +next Wednesday not this Wednesday but + + + align:start position:0% +next Wednesday not this Wednesday but +next Wednesday and what is that the 9th + + align:start position:0% +next Wednesday and what is that the 9th + + + align:start position:0% +next Wednesday and what is that the 9th +it's at the ninth + + align:start position:0% +it's at the ninth + + + align:start position:0% +it's at the ninth +right next Wednesday four nine + + align:start position:0% +right next Wednesday four nine + + + align:start position:0% +right next Wednesday four nine +um this Friday oh sorry next + + align:start position:0% +um this Friday oh sorry next + + + align:start position:0% +um this Friday oh sorry next +next Friday + + align:start position:0% +next Friday + + + align:start position:0% +next Friday +this Friday we're going to work some + + align:start position:0% +this Friday we're going to work some + + + align:start position:0% +this Friday we're going to work some +problems and then + + align:start position:0% +problems and then + + + align:start position:0% +problems and then +um I guess it will be new thermal but + + align:start position:0% +um I guess it will be new thermal but + + + align:start position:0% +um I guess it will be new thermal but +we're going to walk through the nurse + + align:start position:0% +we're going to walk through the nurse + + + align:start position:0% +we're going to walk through the nurse +equation just for your own curiosity and + + align:start position:0% +equation just for your own curiosity and + + + align:start position:0% +equation just for your own curiosity and +interest it won't be tested or covered + + align:start position:0% +interest it won't be tested or covered + + + align:start position:0% +interest it won't be tested or covered +formally in this class and then Monday + + align:start position:0% +formally in this class and then Monday + + + align:start position:0% +formally in this class and then Monday +is the exam and then Wednesday we're + + align:start position:0% +is the exam and then Wednesday we're + + + align:start position:0% +is the exam and then Wednesday we're +going to talk we're going to spend an + + align:start position:0% +going to talk we're going to spend an + + + align:start position:0% +going to talk we're going to spend an +hour talking about social implications + + align:start position:0% +hour talking about social implications + + + align:start position:0% +hour talking about social implications +of Material Science and so we won't + + align:start position:0% +of Material Science and so we won't + + + align:start position:0% +of Material Science and so we won't +really see new you know hardcore course + + align:start position:0% +really see new you know hardcore course + + + align:start position:0% +really see new you know hardcore course +content until next Friday + + align:start position:0% +content until next Friday + + + align:start position:0% +content until next Friday +right + + align:start position:0% +right + + + align:start position:0% +right +okay this is time for questions + + align:start position:0% + + + + align:start position:0% + +um can you explain the Delta h of mixing + + align:start position:0% +um can you explain the Delta h of mixing + + + align:start position:0% +um can you explain the Delta h of mixing +and like how you got that + + align:start position:0% +and like how you got that + + + align:start position:0% +and like how you got that +yeah so + + align:start position:0% +yeah so + + + align:start position:0% +yeah so +um the way I got it is I just told you + + align:start position:0% +um the way I got it is I just told you + + + align:start position:0% +um the way I got it is I just told you +that's the model + + align:start position:0% +that's the model + + + align:start position:0% +that's the model +um it doesn't apparently come from + + align:start position:0% +um it doesn't apparently come from + + + align:start position:0% +um it doesn't apparently come from +anywhere + + align:start position:0% +anywhere + + + align:start position:0% +anywhere +right now + + align:start position:0% +right now + + + align:start position:0% +right now +but I'm glad you have because we do have + + align:start position:0% +but I'm glad you have because we do have + + + align:start position:0% +but I'm glad you have because we do have +something called + + align:start position:0% +something called + + + align:start position:0% +something called +here let's do this + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +and the answer is that um you can say oh + + align:start position:0% + + + + align:start position:0% + +it's empirical I made a bunch of + + align:start position:0% +it's empirical I made a bunch of + + + align:start position:0% +it's empirical I made a bunch of +measurements in this fit the data and + + align:start position:0% +measurements in this fit the data and + + + align:start position:0% +measurements in this fit the data and +historically that's that's probably the + + align:start position:0% +historically that's that's probably the + + + align:start position:0% +historically that's that's probably the +most accurate answer but it also comes + + align:start position:0% +most accurate answer but it also comes + + + align:start position:0% +most accurate answer but it also comes +from something called + + align:start position:0% +from something called + + + align:start position:0% +from something called +the Quasi chemical model and we are + + align:start position:0% +the Quasi chemical model and we are + + + align:start position:0% +the Quasi chemical model and we are +going to + + align:start position:0% +going to + + + align:start position:0% +going to +I believe next Friday + + align:start position:0% +I believe next Friday + + + align:start position:0% +I believe next Friday +um + + align:start position:0% +um + + + align:start position:0% +um +start right here where we try to justify + + align:start position:0% +start right here where we try to justify + + + align:start position:0% +start right here where we try to justify +that + + align:start position:0% +that + + + align:start position:0% +that +and um + + align:start position:0% +and um + + + align:start position:0% +and um +as a preview what we do is we imagine + + align:start position:0% + + + + align:start position:0% + +green and red is never good red and blue + + align:start position:0% +green and red is never good red and blue + + + align:start position:0% +green and red is never good red and blue +is okay we imagine atoms or molecules + + align:start position:0% +is okay we imagine atoms or molecules + + + align:start position:0% +is okay we imagine atoms or molecules +on a lattice + + align:start position:0% + + + + align:start position:0% + +like this + + align:start position:0% + + + + align:start position:0% + +I'm not drawing a nice lattice here + + align:start position:0% + + + + align:start position:0% + +we imagine molecules on a lattice where + + align:start position:0% +we imagine molecules on a lattice where + + + align:start position:0% +we imagine molecules on a lattice where +we have two different components on the + + align:start position:0% +we have two different components on the + + + align:start position:0% +we have two different components on the +lattice + + align:start position:0% +lattice + + + align:start position:0% +lattice +and we say okay all the energy is + + align:start position:0% +and we say okay all the energy is + + + align:start position:0% +and we say okay all the energy is +nearest neighbor bonding so we have blue + + align:start position:0% +nearest neighbor bonding so we have blue + + + align:start position:0% +nearest neighbor bonding so we have blue +blue blue blue blue blue blue blue blue + + align:start position:0% +blue blue blue blue blue blue blue blue + + + align:start position:0% +blue blue blue blue blue blue blue blue +blue blue blue blue blue blue blue blue + + align:start position:0% +blue blue blue blue blue blue blue blue + + + align:start position:0% +blue blue blue blue blue blue blue blue +blue blue blue blue + + align:start position:0% + + + + align:start position:0% + +this is a lot harder to save it so far + + align:start position:0% +this is a lot harder to save it so far + + + align:start position:0% +this is a lot harder to save it so far +and over again I would seem + + align:start position:0% +and over again I would seem + + + align:start position:0% +and over again I would seem +and oh + + align:start position:0% + + + + align:start position:0% + +here we've got some blue red bottoms + + align:start position:0% + + + + align:start position:0% + +and just for completeness let's say I + + align:start position:0% +and just for completeness let's say I + + + align:start position:0% +and just for completeness let's say I +have a red over there there's a red red + + align:start position:0% +have a red over there there's a red red + + + align:start position:0% +have a red over there there's a red red +one and what we're going to do is we're + + align:start position:0% +one and what we're going to do is we're + + + align:start position:0% +one and what we're going to do is we're +we're going to count up these bonds and + + align:start position:0% +we're going to count up these bonds and + + + align:start position:0% +we're going to count up these bonds and +we're going to do some combinatorics and + + align:start position:0% +we're going to do some combinatorics and + + + align:start position:0% +we're going to do some combinatorics and +we're going to end up with this + + align:start position:0% +we're going to end up with this + + + align:start position:0% +we're going to end up with this +expression + + align:start position:0% +expression + + + align:start position:0% +expression +so it does come from somewhere + + align:start position:0% + + + + align:start position:0% + +I would be willing to bet a cup of + + align:start position:0% +I would be willing to bet a cup of + + + align:start position:0% +I would be willing to bet a cup of +coffee that historically comes from + + align:start position:0% +coffee that historically comes from + + + align:start position:0% +coffee that historically comes from +empirical data comes from data and + + align:start position:0% +empirical data comes from data and + + + align:start position:0% +empirical data comes from data and +fitting and people making reasonable + + align:start position:0% +fitting and people making reasonable + + + align:start position:0% +fitting and people making reasonable +guesses as to what empirical what model + + align:start position:0% +guesses as to what empirical what model + + + align:start position:0% +guesses as to what empirical what model +will empirically fit the data and then + + align:start position:0% +will empirically fit the data and then + + + align:start position:0% +will empirically fit the data and then +at some point somebody worked out this + + align:start position:0% +at some point somebody worked out this + + + align:start position:0% +at some point somebody worked out this +model and said oh this is neat this + + align:start position:0% +model and said oh this is neat this + + + align:start position:0% +model and said oh this is neat this +justifies this justifies what we've been + + align:start position:0% +justifies this justifies what we've been + + + align:start position:0% +justifies this justifies what we've been +using all these years + + align:start position:0% + + + + align:start position:0% + +does that help + + align:start position:0% +does that help + + + align:start position:0% +does that help +yeah thank you + + align:start position:0% +yeah thank you + + + align:start position:0% +yeah thank you +how would you how would you how would + + align:start position:0% +how would you how would you how would + + + align:start position:0% +how would you how would you how would +you get that right how would you get + + align:start position:0% +you get that right how would you get + + + align:start position:0% +you get that right how would you get +that + + align:start position:0% +that + + + align:start position:0% +that +well you know you'd have a beaker + + align:start position:0% +well you know you'd have a beaker + + + align:start position:0% +well you know you'd have a beaker +and uh + + align:start position:0% +and uh + + + align:start position:0% +and uh +you would have inside of that beep it + + align:start position:0% +you would have inside of that beep it + + + align:start position:0% +you would have inside of that beep it +doesn't have to be a beaker right it can + + align:start position:0% +doesn't have to be a beaker right it can + + + align:start position:0% +doesn't have to be a beaker right it can +be a crucible or anything and inside of + + align:start position:0% +be a crucible or anything and inside of + + + align:start position:0% +be a crucible or anything and inside of +that you'd have another little + + align:start position:0% + + + + align:start position:0% + +Beaker a crucible and this speaker would + + align:start position:0% +Beaker a crucible and this speaker would + + + align:start position:0% +Beaker a crucible and this speaker would +be full of something which has a large + + align:start position:0% +be full of something which has a large + + + align:start position:0% +be full of something which has a large +heat capacity + + align:start position:0% +heat capacity + + + align:start position:0% +heat capacity +like water + + align:start position:0% +like water + + + align:start position:0% +like water +and it's easy to measure the temperature + + align:start position:0% +and it's easy to measure the temperature + + + align:start position:0% +and it's easy to measure the temperature +of this thing so you've got a + + align:start position:0% +of this thing so you've got a + + + align:start position:0% +of this thing so you've got a +thermometer in there + + align:start position:0% +thermometer in there + + + align:start position:0% +thermometer in there +right so we've got a big thing of water + + align:start position:0% +right so we've got a big thing of water + + + align:start position:0% +right so we've got a big thing of water +and we've got a thermometer in there + + align:start position:0% +and we've got a thermometer in there + + + align:start position:0% +and we've got a thermometer in there +and what we're going to do + + align:start position:0% +and what we're going to do + + + align:start position:0% +and what we're going to do +is we're going to make mixtures so we're + + align:start position:0% +is we're going to make mixtures so we're + + + align:start position:0% +is we're going to make mixtures so we're +going to take sum of a + + align:start position:0% +going to take sum of a + + + align:start position:0% +going to take sum of a +and we're going to take some of B + + align:start position:0% +and we're going to take some of B + + + align:start position:0% +and we're going to take some of B +and we're going to add them to max out + + align:start position:0% +and we're going to add them to max out + + + align:start position:0% +and we're going to add them to max out +my colors here we're going to add them + + align:start position:0% +my colors here we're going to add them + + + align:start position:0% +my colors here we're going to add them +in in different quantities and we're + + align:start position:0% +in in different quantities and we're + + + align:start position:0% +in in different quantities and we're +going to end up with different solutions + + align:start position:0% +going to end up with different solutions + + + align:start position:0% +going to end up with different solutions +in this little beaker + + align:start position:0% +in this little beaker + + + align:start position:0% +in this little beaker +and we're going to measure the + + align:start position:0% +and we're going to measure the + + + align:start position:0% +and we're going to measure the +temperature rise right and so for every + + align:start position:0% +temperature rise right and so for every + + + align:start position:0% +temperature rise right and so for every +composition that I have right we're + + align:start position:0% +composition that I have right we're + + + align:start position:0% +composition that I have right we're +going to have something like this we're + + align:start position:0% +going to have something like this we're + + + align:start position:0% +going to have something like this we're +going to have X of a x of B and A + + align:start position:0% +going to have X of a x of B and A + + + align:start position:0% +going to have X of a x of B and A +temperature rise + + align:start position:0% +temperature rise + + + align:start position:0% +temperature rise +and we measure let's see 0.99 0.01 0.98 + + align:start position:0% +and we measure let's see 0.99 0.01 0.98 + + + align:start position:0% +and we measure let's see 0.99 0.01 0.98 +we're doing a bunch of experiments right + + align:start position:0% +we're doing a bunch of experiments right + + + align:start position:0% +we're doing a bunch of experiments right +and I'm going to have numbers for + + align:start position:0% +and I'm going to have numbers for + + + align:start position:0% +and I'm going to have numbers for +temperature rise + + align:start position:0% +temperature rise + + + align:start position:0% +temperature rise +why does that help me well the + + align:start position:0% +why does that help me well the + + + align:start position:0% +why does that help me well the +temperature Rose in this uh in this big + + align:start position:0% +temperature Rose in this uh in this big + + + align:start position:0% +temperature Rose in this uh in this big +bath of water + + align:start position:0% +bath of water + + + align:start position:0% +bath of water +so I can estimate the heat evolved from + + align:start position:0% +so I can estimate the heat evolved from + + + align:start position:0% +so I can estimate the heat evolved from +this this mixing process because I know + + align:start position:0% +this this mixing process because I know + + + align:start position:0% +this this mixing process because I know +the capacity of water + + align:start position:0% +the capacity of water + + + align:start position:0% +the capacity of water +so the heat of all they're going to be + + align:start position:0% +so the heat of all they're going to be + + + align:start position:0% +so the heat of all they're going to be +numbers + + align:start position:0% +numbers + + + align:start position:0% +numbers +and then I can say oh well this is the + + align:start position:0% +and then I can say oh well this is the + + + align:start position:0% +and then I can say oh well this is the +constant pressure process + + align:start position:0% +constant pressure process + + + align:start position:0% +constant pressure process +so heat and enthalpy is about the same + + align:start position:0% +so heat and enthalpy is about the same + + + align:start position:0% +so heat and enthalpy is about the same +and okay I can model the the heat + + align:start position:0% +and okay I can model the the heat + + + align:start position:0% +and okay I can model the the heat +evolved as a function of composition + + align:start position:0% +evolved as a function of composition + + + align:start position:0% +evolved as a function of composition +and uh maybe it fits this functional + + align:start position:0% +and uh maybe it fits this functional + + + align:start position:0% +and uh maybe it fits this functional +form + + align:start position:0% +form + + + align:start position:0% +form +right that's how this actually would go + + align:start position:0% +right that's how this actually would go + + + align:start position:0% +right that's how this actually would go +that's how this actually does go when we + + align:start position:0% +that's how this actually does go when we + + + align:start position:0% +that's how this actually does go when we +do calorimetry in the lab this isn't you + + align:start position:0% +do calorimetry in the lab this isn't you + + + align:start position:0% +do calorimetry in the lab this isn't you +know + + align:start position:0% +know + + + align:start position:0% +know +um like stuff relegated to you know the + + align:start position:0% +um like stuff relegated to you know the + + + align:start position:0% +um like stuff relegated to you know the +distant past I mean we do this every day + + align:start position:0% +distant past I mean we do this every day + + + align:start position:0% +distant past I mean we do this every day +in the lab + + align:start position:0% +in the lab + + + align:start position:0% +in the lab +uh + + align:start position:0% +uh + + + align:start position:0% +uh +especially those that focus on + + align:start position:0% +especially those that focus on + + + align:start position:0% +especially those that focus on +thermochemistry and such things so \ No newline at end of file diff --git a/o57CTwt1-ck.txt b/o57CTwt1-ck.txt new file mode 100644 index 0000000000000000000000000000000000000000..a476c285d8ac8326d2ae4a304b69dd79387e2787 --- /dev/null +++ b/o57CTwt1-ck.txt @@ -0,0 +1,2627 @@ +align:start position:0% + +if we're going to make use of + + align:start position:0% +if we're going to make use of + + + align:start position:0% +if we're going to make use of +chebychev's bound and other results that + + align:start position:0% +chebychev's bound and other results that + + + align:start position:0% +chebychev's bound and other results that +depend on the variance we'll need some + + align:start position:0% +depend on the variance we'll need some + + + align:start position:0% +depend on the variance we'll need some +methods for calculating various variance + + align:start position:0% +methods for calculating various variance + + + align:start position:0% +methods for calculating various variance +in various circumstances so let's + + align:start position:0% +in various circumstances so let's + + + align:start position:0% +in various circumstances so let's +develop that here a basic place to begin + + align:start position:0% +develop that here a basic place to begin + + + align:start position:0% +develop that here a basic place to begin +is to ask about the indicator very about + + align:start position:0% +is to ask about the indicator very about + + + align:start position:0% +is to ask about the indicator very about +indicator variables and their variance + + align:start position:0% +indicator variables and their variance + + + align:start position:0% +indicator variables and their variance +remember I as an indicator variable + + align:start position:0% +remember I as an indicator variable + + + align:start position:0% +remember I as an indicator variable +means that it's zero one value it's also + + align:start position:0% +means that it's zero one value it's also + + + align:start position:0% +means that it's zero one value it's also +called a Bernoulli variable and if the + + align:start position:0% +called a Bernoulli variable and if the + + + align:start position:0% +called a Bernoulli variable and if the +probability that it equals one is pay + + align:start position:0% +probability that it equals one is pay + + + align:start position:0% +probability that it equals one is pay +that's also its expectation so we have + + align:start position:0% +that's also its expectation so we have + + + align:start position:0% +that's also its expectation so we have +an indicator variable with expectation + + align:start position:0% +an indicator variable with expectation + + + align:start position:0% +an indicator variable with expectation +of the indicator is pay and we're asking + + align:start position:0% +of the indicator is pay and we're asking + + + align:start position:0% +of the indicator is pay and we're asking +what's its variance which my definition + + align:start position:0% +what's its variance which my definition + + + align:start position:0% +what's its variance which my definition +is the expectation of I minus P squared + + align:start position:0% +is the expectation of I minus P squared + + + align:start position:0% +is the expectation of I minus P squared +well this is one of these sort of almost + + align:start position:0% +well this is one of these sort of almost + + + align:start position:0% +well this is one of these sort of almost +mechanical proofs that follows simply by + + align:start position:0% +mechanical proofs that follows simply by + + + align:start position:0% +mechanical proofs that follows simply by +algebra and linearity of expectation but + + align:start position:0% +algebra and linearity of expectation but + + + align:start position:0% +algebra and linearity of expectation but +let's walk through it step by step just + + align:start position:0% +let's walk through it step by step just + + + align:start position:0% +let's walk through it step by step just +to reassure you that that's all that's + + align:start position:0% +to reassure you that that's all that's + + + align:start position:0% +to reassure you that that's all that's +involved I would recommend against + + align:start position:0% +involved I would recommend against + + + align:start position:0% +involved I would recommend against +really trying to memorize this because + + align:start position:0% +really trying to memorize this because + + + align:start position:0% +really trying to memorize this because +it's I can never remember it anyway I + + align:start position:0% +it's I can never remember it anyway I + + + align:start position:0% +it's I can never remember it anyway I +just reprove it every time I need it and + + align:start position:0% +just reprove it every time I need it and + + + align:start position:0% +just reprove it every time I need it and +so let's see how the proof would go so + + align:start position:0% +so let's see how the proof would go so + + + align:start position:0% +so let's see how the proof would go so +step one would be to expand this I minus + + align:start position:0% +step one would be to expand this I minus + + + align:start position:0% +step one would be to expand this I minus +P squared algebraically so we're talking + + align:start position:0% +P squared algebraically so we're talking + + + align:start position:0% +P squared algebraically so we're talking +about the expectation of I squared minus + + align:start position:0% +about the expectation of I squared minus + + + align:start position:0% +about the expectation of I squared minus +two P I plus P squared now we can just + + align:start position:0% +two P I plus P squared now we can just + + + align:start position:0% +two P I plus P squared now we can just +apply linearity of expectation and I get + + align:start position:0% +apply linearity of expectation and I get + + + align:start position:0% +apply linearity of expectation and I get +the expectation of I squared minus two P + + align:start position:0% +the expectation of I squared minus two P + + + align:start position:0% +the expectation of I squared minus two P +times the expectation of I plus P + + align:start position:0% +times the expectation of I plus P + + + align:start position:0% +times the expectation of I plus P +squared of course the expectation of a + + align:start position:0% +squared of course the expectation of a + + + align:start position:0% +squared of course the expectation of a +constant is the constant so when I take + + align:start position:0% +constant is the constant so when I take + + + align:start position:0% +constant is the constant so when I take +expectation of P squared I get P squared + + align:start position:0% +expectation of P squared I get P squared + + + align:start position:0% +expectation of P squared I get P squared +but now look at this I squared is zero + + align:start position:0% +but now look at this I squared is zero + + + align:start position:0% +but now look at this I squared is zero +one value so in fact I squared is equal + + align:start position:0% +one value so in fact I squared is equal + + + align:start position:0% +one value so in fact I squared is equal +to I and the expectation of I has now + + align:start position:0% +to I and the expectation of I has now + + + align:start position:0% +to I and the expectation of I has now +appeared here that's P so this term + + align:start position:0% +appeared here that's P so this term + + + align:start position:0% +appeared here that's P so this term +simplifies to expectation of I and this + + align:start position:0% +simplifies to expectation of I and this + + + align:start position:0% +simplifies to expectation of I and this +term becomes two P times P plus P + + align:start position:0% +term becomes two P times P plus P + + + align:start position:0% +term becomes two P times P plus P +squared of course that expectation of I + + align:start position:0% +squared of course that expectation of I + + + align:start position:0% +squared of course that expectation of I +is a piece I got P minus two P squared + + align:start position:0% +is a piece I got P minus two P squared + + + align:start position:0% +is a piece I got P minus two P squared +plus P squared the P Squared's cancel + + align:start position:0% +plus P squared the P Squared's cancel + + + align:start position:0% +plus P squared the P Squared's cancel +and I get P minus P squared if you + + align:start position:0% +and I get P minus P squared if you + + + align:start position:0% +and I get P minus P squared if you +factor out pay that's P times one minus + + align:start position:0% +factor out pay that's P times one minus + + + align:start position:0% +factor out pay that's P times one minus +P or PQ which is the standard way that + + align:start position:0% +P or PQ which is the standard way that + + + align:start position:0% +P or PQ which is the standard way that +you write the variance of an indicator + + align:start position:0% +you write the variance of an indicator + + + align:start position:0% +you write the variance of an indicator +variable it's P times one minus P okay + + align:start position:0% +variable it's P times one minus P okay + + + align:start position:0% +variable it's P times one minus P okay +that was easy and again completely + + align:start position:0% +that was easy and again completely + + + align:start position:0% +that was easy and again completely +mechanical + + align:start position:0% + + + + align:start position:0% + +there's a couple of other rules for + + align:start position:0% +there's a couple of other rules for + + + align:start position:0% +there's a couple of other rules for +calculating variance from of new + + align:start position:0% +calculating variance from of new + + + align:start position:0% +calculating variance from of new +variables from old ones that are basic + + align:start position:0% +variables from old ones that are basic + + + align:start position:0% +variables from old ones that are basic +like a nativity of expectation but it + + align:start position:0% +like a nativity of expectation but it + + + align:start position:0% +like a nativity of expectation but it +doesn't quite work so simply for + + align:start position:0% +doesn't quite work so simply for + + + align:start position:0% +doesn't quite work so simply for +variance so the first rule is that if + + align:start position:0% +variance so the first rule is that if + + + align:start position:0% +variance so the first rule is that if +you ask about the variance of a constant + + align:start position:0% +you ask about the variance of a constant + + + align:start position:0% +you ask about the variance of a constant +times R plus B that turns out to be the + + align:start position:0% +times R plus B that turns out to be the + + + align:start position:0% +times R plus B that turns out to be the +same as a squared times the variance of + + align:start position:0% +same as a squared times the variance of + + + align:start position:0% +same as a squared times the variance of +biti of our the B doesn't additive B + + align:start position:0% +biti of our the B doesn't additive B + + + align:start position:0% +biti of our the B doesn't additive B +doesn't matter and the because the + + align:start position:0% +doesn't matter and the because the + + + align:start position:0% +doesn't matter and the because the +variance is really the expectation of + + align:start position:0% +variance is really the expectation of + + + align:start position:0% +variance is really the expectation of +something squared when you get rid of + + align:start position:0% +something squared when you get rid of + + + align:start position:0% +something squared when you get rid of +that constant a you're factoring out an + + align:start position:0% +that constant a you're factoring out an + + + align:start position:0% +that constant a you're factoring out an +a squared and this is the rule that you + + align:start position:0% +a squared and this is the rule that you + + + align:start position:0% +a squared and this is the rule that you +get here okay another basic rule that's + + align:start position:0% +get here okay another basic rule that's + + + align:start position:0% +get here okay another basic rule that's +often convenient instead of working with + + align:start position:0% +often convenient instead of working with + + + align:start position:0% +often convenient instead of working with +variance in the form of the expectation + + align:start position:0% +variance in the form of the expectation + + + align:start position:0% +variance in the form of the expectation +of R minus mu squared is to say that + + align:start position:0% +of R minus mu squared is to say that + + + align:start position:0% +of R minus mu squared is to say that +it's the expectation of R squared minus + + align:start position:0% +it's the expectation of R squared minus + + + align:start position:0% +it's the expectation of R squared minus +the square of the expectation of R now + + align:start position:0% +the square of the expectation of R now + + + align:start position:0% +the square of the expectation of R now +this expression the square of the + + align:start position:0% +this expression the square of the + + + align:start position:0% +this expression the square of the +expectation of R comes up so often that + + align:start position:0% +expectation of R comes up so often that + + + align:start position:0% +expectation of R comes up so often that +there's a shorthand for it words that + + align:start position:0% +there's a shorthand for it words that + + + align:start position:0% +there's a shorthand for it words that +are writing parens you write e squared + + align:start position:0% +are writing parens you write e squared + + + align:start position:0% +are writing parens you write e squared +Lavar it just means the same as + + align:start position:0% +Lavar it just means the same as + + + align:start position:0% +Lavar it just means the same as +expectation of R squared and so much for + + align:start position:0% +expectation of R squared and so much for + + + align:start position:0% +expectation of R squared and so much for +the second rule which we'll use all the + + align:start position:0% +the second rule which we'll use all the + + + align:start position:0% +the second rule which we'll use all the +time because it's a convenient rule to + + align:start position:0% +time because it's a convenient rule to + + + align:start position:0% +time because it's a convenient rule to +have I'm going to prove the second one + + align:start position:0% +have I'm going to prove the second one + + + align:start position:0% +have I'm going to prove the second one +just begin to show you nothing to worry + + align:start position:0% +just begin to show you nothing to worry + + + align:start position:0% +just begin to show you nothing to worry +about you don't even have to remember + + align:start position:0% +about you don't even have to remember + + + align:start position:0% +about you don't even have to remember +how the proof goes because you can + + align:start position:0% +how the proof goes because you can + + + align:start position:0% +how the proof goes because you can +reconstruct it every time so this it's + + align:start position:0% +reconstruct it every time so this it's + + + align:start position:0% +reconstruct it every time so this it's +again simple proofs just by linearity of + + align:start position:0% +again simple proofs just by linearity of + + + align:start position:0% +again simple proofs just by linearity of +expectation and doing the algebra so the + + align:start position:0% +expectation and doing the algebra so the + + + align:start position:0% +expectation and doing the algebra so the +variance of R is by definition the + + align:start position:0% +variance of R is by definition the + + + align:start position:0% +variance of R is by definition the +expectation of R minus mu squared let's + + align:start position:0% +expectation of R minus mu squared let's + + + align:start position:0% +expectation of R minus mu squared let's +expand our minus mu squared it's the + + align:start position:0% +expand our minus mu squared it's the + + + align:start position:0% +expand our minus mu squared it's the +expectation of R squared minus 2 mu R + + align:start position:0% +expectation of R squared minus 2 mu R + + + align:start position:0% +expectation of R squared minus 2 mu R +plus mu squared now we apply linearity + + align:start position:0% +plus mu squared now we apply linearity + + + align:start position:0% +plus mu squared now we apply linearity +to that I get the expectation of R + + align:start position:0% +to that I get the expectation of R + + + align:start position:0% +to that I get the expectation of R +squared minus 2 mu expectation of R plus + + align:start position:0% +squared minus 2 mu expectation of R plus + + + align:start position:0% +squared minus 2 mu expectation of R plus +the expectation of MU squared if I'm + + align:start position:0% +the expectation of MU squared if I'm + + + align:start position:0% +the expectation of MU squared if I'm +really being completely mechanical about + + align:start position:0% +really being completely mechanical about + + + align:start position:0% +really being completely mechanical about +linearity of expectation an expectation + + align:start position:0% +linearity of expectation an expectation + + + align:start position:0% +linearity of expectation an expectation +of a constant mu squared is simply mu + + align:start position:0% +of a constant mu squared is simply mu + + + align:start position:0% +of a constant mu squared is simply mu +squared and here I've got the + + align:start position:0% +squared and here I've got the + + + align:start position:0% +squared and here I've got the +expectation off R that's mu again so I + + align:start position:0% +expectation off R that's mu again so I + + + align:start position:0% +expectation off R that's mu again so I +wind up with the expectation of R + + align:start position:0% +wind up with the expectation of R + + + align:start position:0% +wind up with the expectation of R +squared minus 2 + + align:start position:0% +squared minus 2 + + + align:start position:0% +squared minus 2 +mumu plus R squared the this is 2 mu + + align:start position:0% +mumu plus R squared the this is 2 mu + + + align:start position:0% +mumu plus R squared the this is 2 mu +square minus 2 mu squared plus mu + + align:start position:0% +square minus 2 mu squared plus mu + + + align:start position:0% +square minus 2 mu squared plus mu +squared it lines up with minus mu + + align:start position:0% +squared it lines up with minus mu + + + align:start position:0% +squared it lines up with minus mu +squared and of course mu squared is the + + align:start position:0% +squared and of course mu squared is the + + + align:start position:0% +squared and of course mu squared is the +expectation squared of our food the + + align:start position:0% +expectation squared of our food the + + + align:start position:0% +expectation squared of our food the +formula again has claimed there's + + align:start position:0% +formula again has claimed there's + + + align:start position:0% +formula again has claimed there's +nothing interesting here just algebra + + align:start position:0% +nothing interesting here just algebra + + + align:start position:0% +nothing interesting here just algebra +and linearity of expectation and the + + align:start position:0% +and linearity of expectation and the + + + align:start position:0% +and linearity of expectation and the +first result about factoring out in a + + align:start position:0% +first result about factoring out in a + + + align:start position:0% +first result about factoring out in a +and squaring it follows from a similar + + align:start position:0% +and squaring it follows from a similar + + + align:start position:0% +and squaring it follows from a similar +proof which I'm not going to include + + align:start position:0% +proof which I'm not going to include + + + align:start position:0% +proof which I'm not going to include +here so let's look at the space station + + align:start position:0% +here so let's look at the space station + + + align:start position:0% +here so let's look at the space station +Mir again which we used as an example of + + align:start position:0% +Mir again which we used as an example of + + + align:start position:0% +Mir again which we used as an example of +calculating mean time to failure + + align:start position:0% +calculating mean time to failure + + + align:start position:0% +calculating mean time to failure +so the hypothesis that we're making is + + align:start position:0% +so the hypothesis that we're making is + + + align:start position:0% +so the hypothesis that we're making is +that with probability P the MIR space + + align:start position:0% +that with probability P the MIR space + + + align:start position:0% +that with probability P the MIR space +station will run into some huge space + + align:start position:0% +station will run into some huge space + + + align:start position:0% +station will run into some huge space +garbage and that will collaborate and + + align:start position:0% +garbage and that will collaborate and + + + align:start position:0% +garbage and that will collaborate and +the probability of that happening in any + + align:start position:0% +the probability of that happening in any + + + align:start position:0% +the probability of that happening in any +given hour is probability P so we know + + align:start position:0% +given hour is probability P so we know + + + align:start position:0% +given hour is probability P so we know +that that means that the expected number + + align:start position:0% +that that means that the expected number + + + align:start position:0% +that that means that the expected number +of hours for the MIR to fail is 1 over P + + align:start position:0% +of hours for the MIR to fail is 1 over P + + + align:start position:0% +of hours for the MIR to fail is 1 over P +that's the mean time to failure and what + + align:start position:0% +that's the mean time to failure and what + + + align:start position:0% +that's the mean time to failure and what +we're asking is what's the variance of F + + align:start position:0% +we're asking is what's the variance of F + + + align:start position:0% +we're asking is what's the variance of F +if F is the number of hours to failure + + align:start position:0% +if F is the number of hours to failure + + + align:start position:0% +if F is the number of hours to failure +what's variance of F well one way we can + + align:start position:0% +what's variance of F well one way we can + + + align:start position:0% +what's variance of F well one way we can +do to just plug in the definition of + + align:start position:0% +do to just plug in the definition of + + + align:start position:0% +do to just plug in the definition of +expectation and this will work the + + align:start position:0% +expectation and this will work the + + + align:start position:0% +expectation and this will work the +probability that the that it takes K + + align:start position:0% +probability that the that it takes K + + + align:start position:0% +probability that the that it takes K +hours to fail is we know the geometric + + align:start position:0% +hours to fail is we know the geometric + + + align:start position:0% +hours to fail is we know the geometric +distribution the probability of not + + align:start position:0% +distribution the probability of not + + + align:start position:0% +distribution the probability of not +failing for K minus 1 hours and failing + + align:start position:0% +failing for K minus 1 hours and failing + + + align:start position:0% +failing for K minus 1 hours and failing +after that Q to the K minus 1 times P so + + align:start position:0% +after that Q to the K minus 1 times P so + + + align:start position:0% +after that Q to the K minus 1 times P so +the variance of F using our previous + + align:start position:0% +the variance of F using our previous + + + align:start position:0% +the variance of F using our previous +formula about the expectation of F + + align:start position:0% +formula about the expectation of F + + + align:start position:0% +formula about the expectation of F +squared minus the expectation squared of + + align:start position:0% +squared minus the expectation squared of + + + align:start position:0% +squared minus the expectation squared of +F this becomes a minus 101 over P + + align:start position:0% +F this becomes a minus 101 over P + + + align:start position:0% +F this becomes a minus 101 over P +squared and we can forget about that we + + align:start position:0% +squared and we can forget about that we + + + align:start position:0% +squared and we can forget about that we +want to focus on calculating the + + align:start position:0% +want to focus on calculating the + + + align:start position:0% +want to focus on calculating the +expectation of F squared so F is 1 2 3 + + align:start position:0% +expectation of F squared so F is 1 2 3 + + + align:start position:0% +expectation of F squared so F is 1 2 3 +and so on that means F square is 1 4 9 K + + align:start position:0% +and so on that means F square is 1 4 9 K + + + align:start position:0% +and so on that means F square is 1 4 9 K +square the point being that the only + + align:start position:0% +square the point being that the only + + + align:start position:0% +square the point being that the only +value is that F squared can take our + + align:start position:0% +value is that F squared can take our + + + align:start position:0% +value is that F squared can take our +squares so we don't have to worry about + + align:start position:0% +squares so we don't have to worry about + + + align:start position:0% +squares so we don't have to worry about +counting them in in the sum that defines + + align:start position:0% +counting them in in the sum that defines + + + align:start position:0% +counting them in in the sum that defines +the expectation so let's go look at that + + align:start position:0% +the expectation so let's go look at that + + + align:start position:0% +the expectation so let's go look at that +so the expectation of F squared is the + + align:start position:0% +so the expectation of F squared is the + + + align:start position:0% +so the expectation of F squared is the +sum over the possible value + + align:start position:0% +sum over the possible value + + + align:start position:0% +sum over the possible value +that FK squared can take namely the sum + + align:start position:0% +that FK squared can take namely the sum + + + align:start position:0% +that FK squared can take namely the sum +from k equals 1 to infinity of K squared + + align:start position:0% +from k equals 1 to infinity of K squared + + + align:start position:0% +from k equals 1 to infinity of K squared +times the probability that f squared is + + align:start position:0% +times the probability that f squared is + + + align:start position:0% +times the probability that f squared is +equal to K squared well of course the + + align:start position:0% +equal to K squared well of course the + + + align:start position:0% +equal to K squared well of course the +probability that f squared is equal to K + + align:start position:0% +probability that f squared is equal to K + + + align:start position:0% +probability that f squared is equal to K +squared is the same as the probability + + align:start position:0% +squared is the same as the probability + + + align:start position:0% +squared is the same as the probability +that F equals K so I can and we know + + align:start position:0% +that F equals K so I can and we know + + + align:start position:0% +that F equals K so I can and we know +what the probability of that F equals K + + align:start position:0% +what the probability of that F equals K + + + align:start position:0% +what the probability of that F equals K +is it's a geometric distribution so the + + align:start position:0% +is it's a geometric distribution so the + + + align:start position:0% +is it's a geometric distribution so the +probability that F equals K is Q to the + + align:start position:0% +probability that F equals K is Q to the + + + align:start position:0% +probability that F equals K is Q to the +K minus 1 times P if i factor out a P + + align:start position:0% +K minus 1 times P if i factor out a P + + + align:start position:0% +K minus 1 times P if i factor out a P +over Q this simplifies to the sum from k + + align:start position:0% +over Q this simplifies to the sum from k + + + align:start position:0% +over Q this simplifies to the sum from k +equals 0 to infinity of K squared Q to + + align:start position:0% +equals 0 to infinity of K squared Q to + + + align:start position:0% +equals 0 to infinity of K squared Q to +the K and this is a kind of sum that + + align:start position:0% +the K and this is a kind of sum that + + + align:start position:0% +the K and this is a kind of sum that +we've seen before and that it has a + + align:start position:0% +we've seen before and that it has a + + + align:start position:0% +we've seen before and that it has a +closed form and we could perfectly well + + align:start position:0% +closed form and we could perfectly well + + + align:start position:0% +closed form and we could perfectly well +calculate then the expectation of F + + align:start position:0% +calculate then the expectation of F + + + align:start position:0% +calculate then the expectation of F +squared by appealing to our generating + + align:start position:0% +squared by appealing to our generating + + + align:start position:0% +squared by appealing to our generating +function information to get a closed + + align:start position:0% +function information to get a closed + + + align:start position:0% +function information to get a closed +form for this and then remember to + + align:start position:0% +form for this and then remember to + + + align:start position:0% +form for this and then remember to +subtract 1 minus P squared because the + + align:start position:0% +subtract 1 minus P squared because the + + + align:start position:0% +subtract 1 minus P squared because the +variance is this term minus the square + + align:start position:0% +variance is this term minus the square + + + align:start position:0% +variance is this term minus the square +of the expectation of F but let's go + + align:start position:0% +of the expectation of F but let's go + + + align:start position:0% +of the expectation of F but let's go +another way and use the same technique + + align:start position:0% +another way and use the same technique + + + align:start position:0% +another way and use the same technique +of total expectation that we used before + + align:start position:0% +of total expectation that we used before + + + align:start position:0% +of total expectation that we used before +that is the expectation of F squared of + + align:start position:0% +that is the expectation of F squared of + + + align:start position:0% +that is the expectation of F squared of +the failure x squared is equal by the + + align:start position:0% +the failure x squared is equal by the + + + align:start position:0% +the failure x squared is equal by the +law of total probability so the + + align:start position:0% +law of total probability so the + + + align:start position:0% +law of total probability so the +expectation of F squared given that F is + + align:start position:0% +expectation of F squared given that F is + + + align:start position:0% +expectation of F squared given that F is +1 that is we fail after the on the first + + align:start position:0% +1 that is we fail after the on the first + + + align:start position:0% +1 that is we fail after the on the first +step times the probability that we fail + + align:start position:0% +step times the probability that we fail + + + align:start position:0% +step times the probability that we fail +on the first step plus the expectation + + align:start position:0% +on the first step plus the expectation + + + align:start position:0% +on the first step plus the expectation +of F squared given that we don't fail on + + align:start position:0% +of F squared given that we don't fail on + + + align:start position:0% +of F squared given that we don't fail on +the first step that F is greater than 1 + + align:start position:0% +the first step that F is greater than 1 + + + align:start position:0% +the first step that F is greater than 1 +times the probability that F is greater + + align:start position:0% +times the probability that F is greater + + + align:start position:0% +times the probability that F is greater +than 1 now what's going to make this + + align:start position:0% +than 1 now what's going to make this + + + align:start position:0% +than 1 now what's going to make this +manageable is that this expression the + + align:start position:0% +manageable is that this expression the + + + align:start position:0% +manageable is that this expression the +expectation of F squared when F is + + align:start position:0% +expectation of F squared when F is + + + align:start position:0% +expectation of F squared when F is +greater than 1 will turn out to be + + align:start position:0% +greater than 1 will turn out to be + + + align:start position:0% +greater than 1 will turn out to be +something that we can easily convert + + align:start position:0% +something that we can easily convert + + + align:start position:0% +something that we can easily convert +into a non conditional probability and + + align:start position:0% +into a non conditional probability and + + + align:start position:0% +into a non conditional probability and +find a value for so the lemma that we're + + align:start position:0% +find a value for so the lemma that we're + + + align:start position:0% +find a value for so the lemma that we're +using here is the following when I'm + + align:start position:0% +using here is the following when I'm + + + align:start position:0% +using here is the following when I'm +thinking about mean time to failure if I + + align:start position:0% +thinking about mean time to failure if I + + + align:start position:0% +thinking about mean time to failure if I +think of any function whatsoever G of + + align:start position:0% +think of any function whatsoever G of + + + align:start position:0% +think of any function whatsoever G of +the mean time to failure and I'm + + align:start position:0% +the mean time to failure and I'm + + + align:start position:0% +the mean time to failure and I'm +interested in the expectation of G of F + + align:start position:0% +interested in the expectation of G of F + + + align:start position:0% +interested in the expectation of G of F +and I'm interested in the expectation of + + align:start position:0% +and I'm interested in the expectation of + + + align:start position:0% +and I'm interested in the expectation of +G of F given that F is greater than n + + align:start position:0% +G of F given that F is greater than n + + + align:start position:0% +G of F given that F is greater than n +that is it's already taken n steps to + + align:start position:0% +that is it's already taken n steps to + + + align:start position:0% +that is it's already taken n steps to +get where I am then the thing about the + + align:start position:0% +get where I am then the thing about the + + + align:start position:0% +get where I am then the thing about the +mean time to failure is that at any + + align:start position:0% +mean time to failure is that at any + + + align:start position:0% +mean time to failure is that at any +moment + + align:start position:0% +moment + + + align:start position:0% +moment +on what that you haven't failed you're + + align:start position:0% +on what that you haven't failed you're + + + align:start position:0% +on what that you haven't failed you're +starting off in essentially the same + + align:start position:0% +starting off in essentially the same + + + align:start position:0% +starting off in essentially the same +situation you were at the beginning in + + align:start position:0% +situation you were at the beginning in + + + align:start position:0% +situation you were at the beginning in +waiting for the next failure to occur + + align:start position:0% +waiting for the next failure to occur + + + align:start position:0% +waiting for the next failure to occur +and the probability of failing in one + + align:start position:0% +and the probability of failing in one + + + align:start position:0% +and the probability of failing in one +more step is the same probability is the + + align:start position:0% +more step is the same probability is the + + + align:start position:0% +more step is the same probability is the +same P and the probability of you're + + align:start position:0% +same P and the probability of you're + + + align:start position:0% +same P and the probability of you're +failing in two more steps is QP and + + align:start position:0% +failing in two more steps is QP and + + + align:start position:0% +failing in two more steps is QP and +three more steps is Q QP the only + + align:start position:0% +three more steps is Q QP the only + + + align:start position:0% +three more steps is Q QP the only +difference is that the value of F has + + align:start position:0% +difference is that the value of F has + + + align:start position:0% +difference is that the value of F has +been shifted by n it was in the ordinary + + align:start position:0% +been shifted by n it was in the ordinary + + + align:start position:0% +been shifted by n it was in the ordinary +case we start off with F equals zero and + + align:start position:0% +case we start off with F equals zero and + + + align:start position:0% +case we start off with F equals zero and +look at the probability that we failing + + align:start position:0% +look at the probability that we failing + + + align:start position:0% +look at the probability that we failing +one more step two more steps now we're + + align:start position:0% +one more step two more steps now we're + + + align:start position:0% +one more step two more steps now we're +starting off with F having the value F + + align:start position:0% +starting off with F having the value F + + + align:start position:0% +starting off with F having the value F +plus N and asking about the probability + + align:start position:0% +plus N and asking about the probability + + + align:start position:0% +plus N and asking about the probability +that it fails in the next step or the + + align:start position:0% +that it fails in the next step or the + + + align:start position:0% +that it fails in the next step or the +next step on the next step so the + + align:start position:0% +next step on the next step so the + + + align:start position:0% +next step on the next step so the +punchline is that the expectation of G + + align:start position:0% +punchline is that the expectation of G + + + align:start position:0% +punchline is that the expectation of G +of F given that F is greater than n is + + align:start position:0% +of F given that F is greater than n is + + + align:start position:0% +of F given that F is greater than n is +simply the expectation of G of F plus N + + align:start position:0% +simply the expectation of G of F plus N + + + align:start position:0% +simply the expectation of G of F plus N +and I'm gonna let you meditate that and + + align:start position:0% +and I'm gonna let you meditate that and + + + align:start position:0% +and I'm gonna let you meditate that and +not say any more about it but the + + align:start position:0% +not say any more about it but the + + + align:start position:0% +not say any more about it but the +punchline is the corollary that the + + align:start position:0% +punchline is the corollary that the + + + align:start position:0% +punchline is the corollary that the +expectation of F squared given that F is + + align:start position:0% +expectation of F squared given that F is + + + align:start position:0% +expectation of F squared given that F is +greater than 1 is simply the expectation + + align:start position:0% +greater than 1 is simply the expectation + + + align:start position:0% +greater than 1 is simply the expectation +of F plus 1 squared and that lets us go + + align:start position:0% +of F plus 1 squared and that lets us go + + + align:start position:0% +of F plus 1 squared and that lets us go +back and simplify this expression that + + align:start position:0% +back and simplify this expression that + + + align:start position:0% +back and simplify this expression that +we had from total expectation we now + + align:start position:0% +we had from total expectation we now + + + align:start position:0% +we had from total expectation we now +have here's the F expectation of F + + align:start position:0% +have here's the F expectation of F + + + align:start position:0% +have here's the F expectation of F +squared given that F is greater than 1 + + align:start position:0% +squared given that F is greater than 1 + + + align:start position:0% +squared given that F is greater than 1 +and let's look at these other terms this + + align:start position:0% +and let's look at these other terms this + + + align:start position:0% +and let's look at these other terms this +is the expectation of F square given + + align:start position:0% +is the expectation of F square given + + + align:start position:0% +is the expectation of F square given +that F equals 1 well the expectation of + + align:start position:0% +that F equals 1 well the expectation of + + + align:start position:0% +that F equals 1 well the expectation of +F square given that F equals 1 is 1 + + align:start position:0% +F square given that F equals 1 is 1 + + + align:start position:0% +F square given that F equals 1 is 1 +squared because we know what F is and + + align:start position:0% +squared because we know what F is and + + + align:start position:0% +squared because we know what F is and +that's the end of the story + + align:start position:0% +that's the end of the story + + + align:start position:0% +that's the end of the story +times the probability that F equals 1 + + align:start position:0% +times the probability that F equals 1 + + + align:start position:0% +times the probability that F equals 1 +that's P the probability of failure on a + + align:start position:0% +that's P the probability of failure on a + + + align:start position:0% +that's P the probability of failure on a +given step this is the probability that + + align:start position:0% +given step this is the probability that + + + align:start position:0% +given step this is the probability that +F is greater than 1 which is Q that we + + align:start position:0% +F is greater than 1 which is Q that we + + + align:start position:0% +F is greater than 1 which is Q that we +didn't fail on the first step and we + + align:start position:0% +didn't fail on the first step and we + + + align:start position:0% +didn't fail on the first step and we +just figured out that this term is the + + align:start position:0% +just figured out that this term is the + + + align:start position:0% +just figured out that this term is the +expectation of the square of F of F plus + + align:start position:0% +expectation of the square of F of F plus + + + align:start position:0% +expectation of the square of F of F plus +1 so there's the 1 in the P and that + + align:start position:0% +1 so there's the 1 in the P and that + + + align:start position:0% +1 so there's the 1 in the P and that +becomes a Q and this is the expectation + + align:start position:0% +becomes a Q and this is the expectation + + + align:start position:0% +becomes a Q and this is the expectation +of F plus 1 squared now again I apply + + align:start position:0% +of F plus 1 squared now again I apply + + + align:start position:0% +of F plus 1 squared now again I apply +limit linearity I'm going to expand F + + align:start position:0% +limit linearity I'm going to expand F + + + align:start position:0% +limit linearity I'm going to expand F +plus 1 squared into F squared plus 2 F + + align:start position:0% +plus 1 squared into F squared plus 2 F + + + align:start position:0% +plus 1 squared into F squared plus 2 F +plus 1 and then apply linearity of + + align:start position:0% +plus 1 and then apply linearity of + + + align:start position:0% +plus 1 and then apply linearity of +expectation and I'm going to wind up + + align:start position:0% +expectation and I'm going to wind up + + + align:start position:0% +expectation and I'm going to wind up +with the expectation of F squared + + align:start position:0% +with the expectation of F squared + + + align:start position:0% +with the expectation of F squared +twice the expectation of F which + + align:start position:0% +twice the expectation of F which + + + align:start position:0% +twice the expectation of F which +remember is twice over two over P plus 1 + + align:start position:0% +remember is twice over two over P plus 1 + + + align:start position:0% +remember is twice over two over P plus 1 +times the Q and now what I've got is a + + align:start position:0% +times the Q and now what I've got is a + + + align:start position:0% +times the Q and now what I've got is a +simple arithmetic equation between the + + align:start position:0% +simple arithmetic equation between the + + + align:start position:0% +simple arithmetic equation between the +expectation of F squared and some other + + align:start position:0% +expectation of F squared and some other + + + align:start position:0% +expectation of F squared and some other +arithmetic and the expectation of F + + align:start position:0% +arithmetic and the expectation of F + + + align:start position:0% +arithmetic and the expectation of F +squared it's easy to solve for the + + align:start position:0% +squared it's easy to solve for the + + + align:start position:0% +squared it's easy to solve for the +expectation of F squared + + align:start position:0% +expectation of F squared + + + align:start position:0% +expectation of F squared +and I'll spare you that elementary + + align:start position:0% +and I'll spare you that elementary + + + align:start position:0% +and I'll spare you that elementary +simplification but the punchline is when + + align:start position:0% +simplification but the punchline is when + + + align:start position:0% +simplification but the punchline is when +we also remember to subtract 1 over P + + align:start position:0% +we also remember to subtract 1 over P + + + align:start position:0% +we also remember to subtract 1 over P +squared because that was the expectation + + align:start position:0% +squared because that was the expectation + + + align:start position:0% +squared because that was the expectation +of the square of F of the expectation of + + align:start position:0% +of the square of F of the expectation of + + + align:start position:0% +of the square of F of the expectation of +F we come up with this punchline formula + + align:start position:0% +F we come up with this punchline formula + + + align:start position:0% +F we come up with this punchline formula +the variance of mean time to failure is + + align:start position:0% +the variance of mean time to failure is + + + align:start position:0% +the variance of mean time to failure is +1 over the probability of failure on a + + align:start position:0% +1 over the probability of failure on a + + + align:start position:0% +1 over the probability of failure on a +given step times 1 minus 1 over the + + align:start position:0% +given step times 1 minus 1 over the + + + align:start position:0% +given step times 1 minus 1 over the +times the probability 1 over the + + align:start position:0% +times the probability 1 over the + + + align:start position:0% +times the probability 1 over the +probability of a failure in the first + + align:start position:0% +probability of a failure in the first + + + align:start position:0% +probability of a failure in the first +step minus 1 all right let's just for + + align:start position:0% +step minus 1 all right let's just for + + + align:start position:0% +step minus 1 all right let's just for +practice and fun let's look at the space + + align:start position:0% +practice and fun let's look at the space + + + align:start position:0% +practice and fun let's look at the space +station Mir again suppose that I tell + + align:start position:0% +station Mir again suppose that I tell + + + align:start position:0% +station Mir again suppose that I tell +you that there's a 1 in 10,000 chance + + align:start position:0% +you that there's a 1 in 10,000 chance + + + align:start position:0% +you that there's a 1 in 10,000 chance +that in any given hour the mirrors gonna + + align:start position:0% +that in any given hour the mirrors gonna + + + align:start position:0% +that in any given hour the mirrors gonna +crash into some debris that's out there + + align:start position:0% +crash into some debris that's out there + + + align:start position:0% +crash into some debris that's out there +in orbit so the expectation of F is 10 + + align:start position:0% +in orbit so the expectation of F is 10 + + + align:start position:0% +in orbit so the expectation of F is 10 +to the fourth about 10,000 hours and the + + align:start position:0% +to the fourth about 10,000 hours and the + + + align:start position:0% +to the fourth about 10,000 hours and the +Sigma is gonna be the variance of of F + + align:start position:0% +Sigma is gonna be the variance of of F + + + align:start position:0% +Sigma is gonna be the variance of of F +which is about one over one + + align:start position:0% +which is about one over one + + + align:start position:0% +which is about one over one +ten-thousandth then is 10,000 times + + align:start position:0% +ten-thousandth then is 10,000 times + + + align:start position:0% +ten-thousandth then is 10,000 times +10,000 minus one which is pretty close + + align:start position:0% +10,000 minus one which is pretty close + + + align:start position:0% +10,000 minus one which is pretty close +to 10,000 squared for the variance and + + align:start position:0% +to 10,000 squared for the variance and + + + align:start position:0% +to 10,000 squared for the variance and +then when I take the square root I get + + align:start position:0% +then when I take the square root I get + + + align:start position:0% +then when I take the square root I get +back to 10,000 so Sigma is just a tad + + align:start position:0% +back to 10,000 so Sigma is just a tad + + + align:start position:0% +back to 10,000 so Sigma is just a tad +less than than 10,000 it's 10 to the + + align:start position:0% +less than than 10,000 it's 10 to the + + + align:start position:0% +less than than 10,000 it's 10 to the +fourth so with those numbers I can apply + + align:start position:0% +fourth so with those numbers I can apply + + + align:start position:0% +fourth so with those numbers I can apply +the chebyshev theorem and conclude that + + align:start position:0% +the chebyshev theorem and conclude that + + + align:start position:0% +the chebyshev theorem and conclude that +the probability that the near lasts more + + align:start position:0% +the probability that the near lasts more + + + align:start position:0% +the probability that the near lasts more +than 4 times 10 to the 4th hours is less + + align:start position:0% +than 4 times 10 to the 4th hours is less + + + align:start position:0% +than 4 times 10 to the 4th hours is less +than one chance in 4 and if we translate + + align:start position:0% +than one chance in 4 and if we translate + + + align:start position:0% +than one chance in 4 and if we translate +that into years if it was really the + + align:start position:0% +that into years if it was really the + + + align:start position:0% +that into years if it was really the +case that there was a 1 in 10,000 chance + + align:start position:0% +case that there was a 1 in 10,000 chance + + + align:start position:0% +case that there was a 1 in 10,000 chance +of them--are being destroyed in any + + align:start position:0% +of them--are being destroyed in any + + + align:start position:0% +of them--are being destroyed in any +given hour and the probability that it + + align:start position:0% +given hour and the probability that it + + + align:start position:0% +given hour and the probability that it +lasts more than four point six years + + align:start position:0% +lasts more than four point six years + + + align:start position:0% +lasts more than four point six years +before destructing is less than 1/4 + + align:start position:0% + + + + align:start position:0% + +so another rule for calculating variance + + align:start position:0% +so another rule for calculating variance + + + align:start position:0% +so another rule for calculating variance +and then maybe the most important + + align:start position:0% +and then maybe the most important + + + align:start position:0% +and then maybe the most important +general one is that variance is additive + + align:start position:0% +general one is that variance is additive + + + align:start position:0% +general one is that variance is additive +that is the variance of a sum is the sum + + align:start position:0% +that is the variance of a sum is the sum + + + align:start position:0% +that is the variance of a sum is the sum +of the variances but unlike expectation + + align:start position:0% +of the variances but unlike expectation + + + align:start position:0% +of the variances but unlike expectation +where there's no other side condition + + align:start position:0% +where there's no other side condition + + + align:start position:0% +where there's no other side condition +and it does not in any way depend on + + align:start position:0% +and it does not in any way depend on + + + align:start position:0% +and it does not in any way depend on +independence it turns out that variance + + align:start position:0% +independence it turns out that variance + + + align:start position:0% +independence it turns out that variance +is additive only if the variables being + + align:start position:0% +is additive only if the variables being + + + align:start position:0% +is additive only if the variables being +added are pairwise independent now you + + align:start position:0% +added are pairwise independent now you + + + align:start position:0% +added are pairwise independent now you +might wonder where the pairwise came + + align:start position:0% +might wonder where the pairwise came + + + align:start position:0% +might wonder where the pairwise came +from and it's because variance is the + + align:start position:0% +from and it's because variance is the + + + align:start position:0% +from and it's because variance is the +square of an expectation so when you + + align:start position:0% +square of an expectation so when you + + + align:start position:0% +square of an expectation so when you +wind up multiplying out and doing the + + align:start position:0% +wind up multiplying out and doing the + + + align:start position:0% +wind up multiplying out and doing the +algebra you're just getting quadratic + + align:start position:0% +algebra you're just getting quadratic + + + align:start position:0% +algebra you're just getting quadratic +terms that you for variances of four + + align:start position:0% +terms that you for variances of four + + + align:start position:0% +terms that you for variances of four +expectations of RI times RJ and so you + + align:start position:0% +expectations of RI times RJ and so you + + + align:start position:0% +expectations of RI times RJ and so you +need to factor those into into + + align:start position:0% +need to factor those into into + + + align:start position:0% +need to factor those into into +expectation of our x expect our I times + + align:start position:0% +expectation of our x expect our I times + + + align:start position:0% +expectation of our x expect our I times +expectation of RJ which you only need + + align:start position:0% +expectation of RJ which you only need + + + align:start position:0% +expectation of RJ which you only need +pairwise independence for so that's a + + align:start position:0% +pairwise independence for so that's a + + + align:start position:0% +pairwise independence for so that's a +fast-talking through the algebra that + + align:start position:0% +fast-talking through the algebra that + + + align:start position:0% +fast-talking through the algebra that +I'm going to leave to you it's in the + + align:start position:0% +I'm going to leave to you it's in the + + + align:start position:0% +I'm going to leave to you it's in the +text and it's again one of these easy + + align:start position:0% +text and it's again one of these easy + + + align:start position:0% +text and it's again one of these easy +proofs + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/o93axeQJqJ8.txt b/o93axeQJqJ8.txt new file mode 100644 index 0000000000000000000000000000000000000000..7d95b3873cdadd743a4380cefb8bb97a70bf2dd3 --- /dev/null +++ b/o93axeQJqJ8.txt @@ -0,0 +1,1723 @@ +align:start position:0% + +okay well well you see spring has + + align:start position:0% +okay well well you see spring has + + + align:start position:0% +okay well well you see spring has +finally come to Boston my sweater is + + align:start position:0% +finally come to Boston my sweater is + + + align:start position:0% +finally come to Boston my sweater is +gone and uh it's April the 16th I think + + align:start position:0% +gone and uh it's April the 16th I think + + + align:start position:0% +gone and uh it's April the 16th I think +it's getting the late spring okay so + + align:start position:0% +it's getting the late spring okay so + + + align:start position:0% +it's getting the late spring okay so +today this video is the nice case + + align:start position:0% +today this video is the nice case + + + align:start position:0% +today this video is the nice case +constant coefficients linear equations + + align:start position:0% +constant coefficients linear equations + + + align:start position:0% +constant coefficients linear equations +and the right hand side is an + + align:start position:0% +and the right hand side is an + + + align:start position:0% +and the right hand side is an +exponential those are the best and we've + + align:start position:0% +exponential those are the best and we've + + + align:start position:0% +exponential those are the best and we've +seen that before in fact let me extend + + align:start position:0% +seen that before in fact let me extend + + + align:start position:0% +seen that before in fact let me extend +to from we saw it for first order + + align:start position:0% +to from we saw it for first order + + + align:start position:0% +to from we saw it for first order +equations here it is for second order + + align:start position:0% +equations here it is for second order + + + align:start position:0% +equations here it is for second order +equations and it could be an nth order + + align:start position:0% +equations and it could be an nth order + + + align:start position:0% +equations and it could be an nth order +equation we could have the nth + + align:start position:0% +equation we could have the nth + + + align:start position:0% +equation we could have the nth +derivative and all lower derivatives the + + align:start position:0% +derivative and all lower derivatives the + + + align:start position:0% +derivative and all lower derivatives the +first derivative the function itself + + align:start position:0% +first derivative the function itself + + + align:start position:0% +first derivative the function itself +zeroth derivative with coefficients + + align:start position:0% +zeroth derivative with coefficients + + + align:start position:0% +zeroth derivative with coefficients +constant coefficients equaling e to the + + align:start position:0% +constant coefficients equaling e to the + + + align:start position:0% +constant coefficients equaling e to the +St that's what makes it easy and what do + + align:start position:0% +St that's what makes it easy and what do + + + align:start position:0% +St that's what makes it easy and what do +we do when the right hand side is e to + + align:start position:0% +we do when the right hand side is e to + + + align:start position:0% +we do when the right hand side is e to +the St we look for a solution a multiple + + align:start position:0% +the St we look for a solution a multiple + + + align:start position:0% +the St we look for a solution a multiple +of e to the St capital y * e to the St + + align:start position:0% +of e to the St capital y * e to the St + + + align:start position:0% +of e to the St capital y * e to the St +that's going to work we just plug into + + align:start position:0% +that's going to work we just plug into + + + align:start position:0% +that's going to work we just plug into +the equation to find that transfer + + align:start position:0% +the equation to find that transfer + + + align:start position:0% +the equation to find that transfer +function capital Y can I just do that + + align:start position:0% +function capital Y can I just do that + + + align:start position:0% +function capital Y can I just do that +I'll do it for the big the INF degree + + align:start position:0% +I'll do it for the big the INF degree + + + align:start position:0% +I'll do it for the big the INF degree +why not so when I plug this in for y + + align:start position:0% +why not so when I plug this in for y + + + align:start position:0% +why not so when I plug this in for y +every derivative brings an S so there's + + align:start position:0% +every derivative brings an S so there's + + + align:start position:0% +every derivative brings an S so there's +the the capital Y is still there the + + align:start position:0% +the the capital Y is still there the + + + align:start position:0% +the the capital Y is still there the +exponential is going to be still there + + align:start position:0% +exponential is going to be still there + + + align:start position:0% +exponential is going to be still there +and then there all the s's that that + + align:start position:0% +and then there all the s's that that + + + align:start position:0% +and then there all the s's that that +come down from the derivatives n s's + + align:start position:0% +come down from the derivatives n s's + + + align:start position:0% +come down from the derivatives n s's +from the nth derivative 1 s from the + + align:start position:0% +from the nth derivative 1 s from the + + + align:start position:0% +from the nth derivative 1 s from the +first derivative no s from the constant + + align:start position:0% +first derivative no s from the constant + + + align:start position:0% +first derivative no s from the constant +term do you see that equation is exactly + + align:start position:0% +term do you see that equation is exactly + + + align:start position:0% +term do you see that equation is exactly +like what we had before with a S2 + b s + + align:start position:0% +like what we had before with a S2 + b s + + + align:start position:0% +like what we had before with a S2 + b s ++ C we had quadratic equation the most + + align:start position:0% ++ C we had quadratic equation the most + + + align:start position:0% ++ C we had quadratic equation the most +important case now I'm including that + + align:start position:0% +important case now I'm including that + + + align:start position:0% +important case now I'm including that +with any any degree equation in degree + + align:start position:0% +with any any degree equation in degree + + + align:start position:0% +with any any degree equation in degree +equation okay and what's the solution + + align:start position:0% +equation okay and what's the solution + + + align:start position:0% +equation okay and what's the solution +for + + align:start position:0% +for + + + align:start position:0% +for +y because e to the St cancels e to the + + align:start position:0% +y because e to the St cancels e to the + + + align:start position:0% +y because e to the St cancels e to the +St that whole thing equals 1 I divide by + + align:start position:0% +St that whole thing equals 1 I divide by + + + align:start position:0% +St that whole thing equals 1 I divide by +this and I get y = 1 over that key + + align:start position:0% +this and I get y = 1 over that key + + + align:start position:0% +this and I get y = 1 over that key +polinomial it's a Nth Degree polinomial + + align:start position:0% +polinomial it's a Nth Degree polinomial + + + align:start position:0% +polinomial it's a Nth Degree polinomial +it's and the one over it is called the + + align:start position:0% +it's and the one over it is called the + + + align:start position:0% +it's and the one over it is called the +transfer function and uh it that + + align:start position:0% +transfer function and uh it that + + + align:start position:0% +transfer function and uh it that +transfer function transfers the input e + + align:start position:0% +transfer function transfers the input e + + + align:start position:0% +transfer function transfers the input e +to the St to the output y e to the St + + align:start position:0% +to the St to the output y e to the St + + + align:start position:0% +to the St to the output y e to the St +it's the it gives the exponential + + align:start position:0% +it's the it gives the exponential + + + align:start position:0% +it's the it gives the exponential +response very nice formula couldn't be + + align:start position:0% +response very nice formula couldn't be + + + align:start position:0% +response very nice formula couldn't be +better and you remember when for second + + align:start position:0% +better and you remember when for second + + + align:start position:0% +better and you remember when for second +degree equations our most important case + + align:start position:0% +degree equations our most important case + + + align:start position:0% +degree equations our most important case +is a S 2 b s + C okay that's the + + align:start position:0% +is a S 2 b s + C okay that's the + + + align:start position:0% +is a S 2 b s + C okay that's the +solution almost every time but one thing + + align:start position:0% +solution almost every time but one thing + + + align:start position:0% +solution almost every time but one thing +can go wrong one thing can go wrong + + align:start position:0% +can go wrong one thing can go wrong + + + align:start position:0% +can go wrong one thing can go wrong +suppose for the particular s the + + align:start position:0% +suppose for the particular s the + + + align:start position:0% +suppose for the particular s the +particular exponent in the in the + + align:start position:0% +particular exponent in the in the + + + align:start position:0% +particular exponent in the in the +forcing function suppose that s in the + + align:start position:0% +forcing function suppose that s in the + + + align:start position:0% +forcing function suppose that s in the +forcing function is also an one of the + + align:start position:0% +forcing function is also an one of the + + + align:start position:0% +forcing function is also an one of the +s's in the null Solutions you remember + + align:start position:0% +s's in the null Solutions you remember + + + align:start position:0% +s's in the null Solutions you remember +the null Solutions with the that there + + align:start position:0% +the null Solutions with the that there + + + align:start position:0% +the null Solutions with the that there +are two + + align:start position:0% +are two + + + align:start position:0% +are two +s's S1 and S2 that make this zero that + + align:start position:0% +s's S1 and S2 that make this zero that + + + align:start position:0% +s's S1 and S2 that make this zero that +make that zero those are the S1 and S2 + + align:start position:0% +make that zero those are the S1 and S2 + + + align:start position:0% +make that zero those are the S1 and S2 +that go into the null + + align:start position:0% +that go into the null + + + align:start position:0% +that go into the null +Solutions now if the forcing s is one of + + align:start position:0% +Solutions now if the forcing s is one of + + + align:start position:0% +Solutions now if the forcing s is one of +those null solution + + align:start position:0% +those null solution + + + align:start position:0% +those null solution +s's we have a problem because this is 1 + + align:start position:0% +s's we have a problem because this is 1 + + + align:start position:0% +s's we have a problem because this is 1 +over + + align:start position:0% +over + + + align:start position:0% +over +zero and we can't uh we haven't got an + + align:start position:0% +zero and we can't uh we haven't got an + + + align:start position:0% +zero and we can't uh we haven't got an +answer yet one over zero has no meaning + + align:start position:0% +answer yet one over zero has no meaning + + + align:start position:0% +answer yet one over zero has no meaning +so I have to this is called resonance + + align:start position:0% +so I have to this is called resonance + + + align:start position:0% +so I have to this is called resonance +resonance is when the forcing exponent + + align:start position:0% +resonance is when the forcing exponent + + + align:start position:0% +resonance is when the forcing exponent +is one of the null exponents that make + + align:start position:0% +is one of the null exponents that make + + + align:start position:0% +is one of the null exponents that make +this zero and there are two of those for + + align:start position:0% +this zero and there are two of those for + + + align:start position:0% +this zero and there are two of those for +for second order equations and there + + align:start position:0% +for second order equations and there + + + align:start position:0% +for second order equations and there +will be n + + align:start position:0% +will be n + + + align:start position:0% +will be n +different s's S1 S2 up to SN for nth + + align:start position:0% +different s's S1 S2 up to SN for nth + + + align:start position:0% +different s's S1 S2 up to SN for nth +degree equations those would be called + + align:start position:0% +degree equations those would be called + + + align:start position:0% +degree equations those would be called +those special s's I could also call them + + align:start position:0% +those special s's I could also call them + + + align:start position:0% +those special s's I could also call them +polls of the transfer function the + + align:start position:0% +polls of the transfer function the + + + align:start position:0% +polls of the transfer function the +transfer function has this in the + + align:start position:0% +transfer function has this in the + + + align:start position:0% +transfer function has this in the +denominator and when this is zero uh + + align:start position:0% +denominator and when this is zero uh + + + align:start position:0% +denominator and when this is zero uh +that identifies a pole so the S1 S2 to + + align:start position:0% +that identifies a pole so the S1 S2 to + + + align:start position:0% +that identifies a pole so the S1 S2 to +SN are the poles and we hope that this s + + align:start position:0% +SN are the poles and we hope that this s + + + align:start position:0% +SN are the poles and we hope that this s +is not one of those but it could be and + + align:start position:0% +is not one of those but it could be and + + + align:start position:0% +is not one of those but it could be and +if it is we need a new formula so that's + + align:start position:0% +if it is we need a new formula so that's + + + align:start position:0% +if it is we need a new formula so that's +the the only remaining case this is + + align:start position:0% +the the only remaining case this is + + + align:start position:0% +the the only remaining case this is +completely nice picture we just need + + align:start position:0% +completely nice picture we just need + + + align:start position:0% +completely nice picture we just need +this last case of + + align:start position:0% + + + + align:start position:0% + +resonance when s equals say S1 kind I'll + + align:start position:0% +resonance when s equals say S1 kind I'll + + + align:start position:0% +resonance when s equals say S1 kind I'll +just pick S1 and when a I know that a S1 + + align:start position:0% +just pick S1 and when a I know that a S1 + + + align:start position:0% +just pick S1 and when a I know that a S1 +2 + B S1 + C is + + align:start position:0% +2 + B S1 + C is + + + align:start position:0% +2 + B S1 + C is +zero so y would be 1 over Z and we can't + + align:start position:0% +zero so y would be 1 over Z and we can't + + + align:start position:0% +zero so y would be 1 over Z and we can't +live with that I've written here for the + + align:start position:0% +live with that I've written here for the + + + align:start position:0% +live with that I've written here for the +second degree equation same possibility + + align:start position:0% +second degree equation same possibility + + + align:start position:0% +second degree equation same possibility +for the N degree a ns1 to the N plus + + align:start position:0% +for the N degree a ns1 to the N plus + + + align:start position:0% +for the N degree a ns1 to the N plus +plus a0 equal 0 that would be a problem + + align:start position:0% +plus a0 equal 0 that would be a problem + + + align:start position:0% +plus a0 equal 0 that would be a problem +of resonance in the N equation this + + align:start position:0% +of resonance in the N equation this + + + align:start position:0% +of resonance in the N equation this +gives us resonance you see because you + + align:start position:0% +gives us resonance you see because you + + + align:start position:0% +gives us resonance you see because you +remember the null Solutions were e e to + + align:start position:0% +remember the null Solutions were e e to + + + align:start position:0% +remember the null Solutions were e e to +the s1t was a null + + align:start position:0% +the s1t was a null + + + align:start position:0% +the s1t was a null +solution if I plug in e to the S1 T the + + align:start position:0% +solution if I plug in e to the S1 T the + + + align:start position:0% +solution if I plug in e to the S1 T the +left side will give zero so I can't get + + align:start position:0% +left side will give zero so I can't get + + + align:start position:0% +left side will give zero so I can't get +a for equal to a forcing term on the + + align:start position:0% +a for equal to a forcing term on the + + + align:start position:0% +a for equal to a forcing term on the +right side I need a new solution what I + + align:start position:0% +right side I need a new solution what I + + + align:start position:0% +right side I need a new solution what I +need a + + align:start position:0% + + + + align:start position:0% + +new new y of + + align:start position:0% +new new y of + + + align:start position:0% +new new y of +T + + align:start position:0% +T + + + align:start position:0% +T +okay can I tell you what it + + align:start position:0% + + + + align:start position:0% + +is and it comes it's a typical case of + + align:start position:0% +is and it comes it's a typical case of + + + align:start position:0% +is and it comes it's a typical case of +lal's rule from calculus when we + + align:start position:0% +lal's rule from calculus when we + + + align:start position:0% +lal's rule from calculus when we +approach this bad + + align:start position:0% +approach this bad + + + align:start position:0% +approach this bad +situation and we're getting a one over + + align:start position:0% +situation and we're getting a one over + + + align:start position:0% +situation and we're getting a one over +zero + + align:start position:0% +zero + + + align:start position:0% +zero +but well you'll see a zero over zero and + + align:start position:0% +but well you'll see a zero over zero and + + + align:start position:0% +but well you'll see a zero over zero and +that's what Lal is aimed for okay so + + align:start position:0% +that's what Lal is aimed for okay so + + + align:start position:0% +that's what Lal is aimed for okay so +where do we start so we our y particular + + align:start position:0% +where do we start so we our y particular + + + align:start position:0% +where do we start so we our y particular +solution is this e to the s t + + align:start position:0% +solution is this e to the s t + + + align:start position:0% +solution is this e to the s t +over uh + + align:start position:0% +over uh + + + align:start position:0% +over uh +yeah e e to the + + align:start position:0% +yeah e e to the + + + align:start position:0% +yeah e e to the +St o over the the + + align:start position:0% +St o over the the + + + align:start position:0% +St o over the the +uh this A S 2 + b s + + + align:start position:0% +uh this A S 2 + b s + + + + align:start position:0% +uh this A S 2 + b s + +C right that's our particular solution + + align:start position:0% +C right that's our particular solution + + + align:start position:0% +C right that's our particular solution +if it works resonance is the case when + + align:start position:0% +if it works resonance is the case when + + + align:start position:0% +if it works resonance is the case when +this doesn't work because that's zero + + align:start position:0% +this doesn't work because that's zero + + + align:start position:0% +this doesn't work because that's zero +now that's a particular solution I'll + + align:start position:0% +now that's a particular solution I'll + + + align:start position:0% +now that's a particular solution I'll +subtract off a null solution I can do + + align:start position:0% +subtract off a null solution I can do + + + align:start position:0% +subtract off a null solution I can do +that I still have a solution so I'll + + align:start position:0% +that I still have a solution so I'll + + + align:start position:0% +that I still have a solution so I'll +subtract off e to the S1 + + align:start position:0% +subtract off e to the S1 + + + align:start position:0% +subtract off e to the S1 +T So S1 is a is e to the s1t is a null + + align:start position:0% +T So S1 is a is e to the s1t is a null + + + align:start position:0% +T So S1 is a is e to the s1t is a null +solution this is what I would call a + + align:start position:0% +solution this is what I would call a + + + align:start position:0% +solution this is what I would call a +very particular solution it's very + + align:start position:0% +very particular solution it's very + + + align:start position:0% +very particular solution it's very +particular because at T equals 0 it's + + align:start position:0% +particular because at T equals 0 it's + + + align:start position:0% +particular because at T equals 0 it's +zero and so do you see that you see + + align:start position:0% +zero and so do you see that you see + + + align:start position:0% +zero and so do you see that you see +what's happening here the question + + align:start position:0% +what's happening here the question + + + align:start position:0% +what's happening here the question +resonance happens when s approaches S1 + + align:start position:0% +resonance happens when s approaches S1 + + + align:start position:0% +resonance happens when s approaches S1 +resonance is s equal to Resonance itself + + align:start position:0% +resonance is s equal to Resonance itself + + + align:start position:0% +resonance is s equal to Resonance itself +is at the thing now we now we let s + + align:start position:0% +is at the thing now we now we let s + + + align:start position:0% +is at the thing now we now we let s +sneak up on + + align:start position:0% +sneak up on + + + align:start position:0% +sneak up on +S1 and we ask what happens to that + + align:start position:0% +S1 and we ask what happens to that + + + align:start position:0% +S1 and we ask what happens to that +formula you see we're sneaking up on + + align:start position:0% +formula you see we're sneaking up on + + + align:start position:0% +formula you see we're sneaking up on +resonance resonance in at resonance when + + align:start position:0% +resonance resonance in at resonance when + + + align:start position:0% +resonance resonance in at resonance when +s equals S1 that will be zero and that + + align:start position:0% +s equals S1 that will be zero and that + + + align:start position:0% +s equals S1 that will be zero and that +will be + + align:start position:0% +will be + + + align:start position:0% +will be +zero that's our + + align:start position:0% +zero that's our + + + align:start position:0% +zero that's our +problem so approach it and you end up + + align:start position:0% +problem so approach it and you end up + + + align:start position:0% +problem so approach it and you end up +with the derivative of this divided by + + align:start position:0% +with the derivative of this divided by + + + align:start position:0% +with the derivative of this divided by +the derivative of this do you remember l + + align:start position:0% +the derivative of this do you remember l + + + align:start position:0% +the derivative of this do you remember l +t it was a crazy rule in calculus but + + align:start position:0% +t it was a crazy rule in calculus but + + + align:start position:0% +t it was a crazy rule in calculus but +here it's actually needed so as s goes + + align:start position:0% +here it's actually needed so as s goes + + + align:start position:0% +here it's actually needed so as s goes +to + + align:start position:0% +to + + + align:start position:0% +to +S1 this goes to 0 over Z so I have to + + align:start position:0% +S1 this goes to 0 over Z so I have to + + + align:start position:0% +S1 this goes to 0 over Z so I have to +take derivative over derivative so let + + align:start position:0% +take derivative over derivative so let + + + align:start position:0% +take derivative over derivative so let +me write the answer + + align:start position:0% +me write the answer + + + align:start position:0% +me write the answer +y resonant can I call this the resonant + + align:start position:0% +y resonant can I call this the resonant + + + align:start position:0% +y resonant can I call this the resonant +solution when s equals S1 and what does + + align:start position:0% +solution when s equals S1 and what does + + + align:start position:0% +solution when s equals S1 and what does +it equal well s is I take the S + + align:start position:0% +it equal well s is I take the S + + + align:start position:0% +it equal well s is I take the S +derivative of this and divide by the S + + align:start position:0% +derivative of this and divide by the S + + + align:start position:0% +derivative of this and divide by the S +derivative of that derivative over + + align:start position:0% +derivative of that derivative over + + + align:start position:0% +derivative of that derivative over +derivative the S derivative of that is t + + align:start position:0% +derivative the S derivative of that is t + + + align:start position:0% +derivative the S derivative of that is t +e to the + + align:start position:0% + + + + align:start position:0% + +St and the S derivative of this is 2 a s + + align:start position:0% +St and the S derivative of this is 2 a s + + + align:start position:0% +St and the S derivative of this is 2 a s ++ + + align:start position:0% + + + + align:start position:0% + +b and + + align:start position:0% +b and + + + align:start position:0% +b and +now I have derivative over derivative I + + align:start position:0% +now I have derivative over derivative I + + + align:start position:0% +now I have derivative over derivative I +can let s go to S1 so s goes to S1 this + + align:start position:0% +can let s go to S1 so s goes to S1 this + + + align:start position:0% +can let s go to S1 so s goes to S1 this +goes to S1 and I get an answer the right + + align:start position:0% +goes to S1 and I get an answer the right + + + align:start position:0% +goes to S1 and I get an answer the right +answer this is the correct + + align:start position:0% +answer this is the correct + + + align:start position:0% +answer this is the correct +solution and you notice everybody spots + + align:start position:0% +solution and you notice everybody spots + + + align:start position:0% +solution and you notice everybody spots +this T factor that t factor is a signal + + align:start position:0% +this T factor that t factor is a signal + + + align:start position:0% +this T factor that t factor is a signal +to everyone that we're in a special case + + align:start position:0% +to everyone that we're in a special case + + + align:start position:0% +to everyone that we're in a special case +when two things happen to be equal here + + align:start position:0% +when two things happen to be equal here + + + align:start position:0% +when two things happen to be equal here +the two things are the S and the S1 so + + align:start position:0% +the two things are the S and the S1 so + + + align:start position:0% +the two things are the S and the S1 so +that that will work so do you see the + + align:start position:0% +that that will work so do you see the + + + align:start position:0% +that that will work so do you see the +general picture it's always this t e to + + align:start position:0% +general picture it's always this t e to + + + align:start position:0% +general picture it's always this t e to +the s1t ab above and down below we have + + align:start position:0% +the s1t ab above and down below we have + + + align:start position:0% +the s1t ab above and down below we have +the + + align:start position:0% +the + + + align:start position:0% +the +derivative of this polinomial at s equal + + align:start position:0% +derivative of this polinomial at s equal + + + align:start position:0% +derivative of this polinomial at s equal +S1 and now you know it's theoretically + + align:start position:0% +S1 and now you know it's theoretically + + + align:start position:0% +S1 and now you know it's theoretically +possible that we could have double + + align:start position:0% +possible that we could have double + + + align:start position:0% +possible that we could have double +resonance we would have double resonance + + align:start position:0% +resonance we would have double resonance + + + align:start position:0% +resonance we would have double resonance +if that thing is zero + + align:start position:0% +if that thing is zero + + + align:start position:0% +if that thing is zero +if not only if if S1 was a double root + + align:start position:0% +if not only if if S1 was a double root + + + align:start position:0% +if not only if if S1 was a double root +if S1 was a double root then well that's + + align:start position:0% +if S1 was a double root then well that's + + + align:start position:0% +if S1 was a double root then well that's +just absurd but it could happen then not + + align:start position:0% +just absurd but it could happen then not + + + align:start position:0% +just absurd but it could happen then not +only is that denominator zero but after + + align:start position:0% +only is that denominator zero but after + + + align:start position:0% +only is that denominator zero but after +L after one use of Lal so we have to + + align:start position:0% +L after one use of Lal so we have to + + + align:start position:0% +L after one use of Lal so we have to +drag Lal back from the hospital and and + + align:start position:0% +drag Lal back from the hospital and and + + + align:start position:0% +drag Lal back from the hospital and and +say do it again so we would have a + + align:start position:0% +say do it again so we would have a + + + align:start position:0% +say do it again so we would have a +second derivative I I won't write down + + align:start position:0% +second derivative I I won't write down + + + align:start position:0% +second derivative I I won't write down +that solution cuz it's pretty rare So + + align:start position:0% +that solution cuz it's pretty rare So + + + align:start position:0% +that solution cuz it's pretty rare So +what has this video done + + align:start position:0% +what has this video done + + + align:start position:0% +what has this video done +simply put on record the + + align:start position:0% +simply put on record the + + + align:start position:0% +simply put on record the +simplest uh case possible with a forcing + + align:start position:0% +simplest uh case possible with a forcing + + + align:start position:0% +simplest uh case possible with a forcing +function e to the + + align:start position:0% +function e to the + + + align:start position:0% +function e to the +St and above all we've identified this + + align:start position:0% +St and above all we've identified this + + + align:start position:0% +St and above all we've identified this +transfer function and let me just + + align:start position:0% +transfer function and let me just + + + align:start position:0% +transfer function and let me just +anticipate that if we another way to + + align:start position:0% +anticipate that if we another way to + + + align:start position:0% +anticipate that if we another way to +solve these + + align:start position:0% +solve these + + + align:start position:0% +solve these +equations instead of in the T domain we + + align:start position:0% +equations instead of in the T domain we + + + align:start position:0% +equations instead of in the T domain we +could go to the lass + + align:start position:0% +could go to the lass + + + align:start position:0% +could go to the lass +transform in the S domain we could solve + + align:start position:0% +transform in the S domain we could solve + + + align:start position:0% +transform in the S domain we could solve +it in the S domain and this is exactly + + align:start position:0% +it in the S domain and this is exactly + + + align:start position:0% +it in the S domain and this is exactly +what will meet when we take the lass + + align:start position:0% +what will meet when we take the lass + + + align:start position:0% +what will meet when we take the lass +transform that will be the llas + + align:start position:0% +transform that will be the llas + + + align:start position:0% +transform that will be the llas +transform which we have to uh deal with + + align:start position:0% +transform which we have to uh deal with + + + align:start position:0% +transform which we have to uh deal with +so uh that transfer function is a + + align:start position:0% +so uh that transfer function is a + + + align:start position:0% +so uh that transfer function is a +fundamental th this polom tells us uh + + align:start position:0% +fundamental th this polom tells us uh + + + align:start position:0% +fundamental th this polom tells us uh +its roots tell us the frequencies S1 S2 + + align:start position:0% +its roots tell us the frequencies S1 S2 + + + align:start position:0% +its roots tell us the frequencies S1 S2 +in the null solution + + align:start position:0% +in the null solution + + + align:start position:0% +in the null solution +and then one over that tells us the + + align:start position:0% +and then one over that tells us the + + + align:start position:0% +and then one over that tells us the +right multiplier in the force + + align:start position:0% +right multiplier in the force + + + align:start position:0% +right multiplier in the force +solution so constant coefficients + + align:start position:0% +solution so constant coefficients + + + align:start position:0% +solution so constant coefficients +exponential forcing the best case + + align:start position:0% +exponential forcing the best case + + + align:start position:0% +exponential forcing the best case +possible thank you \ No newline at end of file diff --git a/oO5yP0cqEIw.txt b/oO5yP0cqEIw.txt new file mode 100644 index 0000000000000000000000000000000000000000..3ed83e93788fd94a3e22233ed932fd571b916338 --- /dev/null +++ b/oO5yP0cqEIw.txt @@ -0,0 +1,331 @@ +align:start position:0% + +explosion. Here we use a laser with a + + align:start position:0% +explosion. Here we use a laser with a + + + align:start position:0% +explosion. Here we use a laser with a +wavelength of 650 nanometers. First take + + align:start position:0% +wavelength of 650 nanometers. First take + + + align:start position:0% +wavelength of 650 nanometers. First take +off the columnating lens of the laser. + + align:start position:0% + + + + align:start position:0% + +Position the laser beam with close pin + + align:start position:0% +Position the laser beam with close pin + + + align:start position:0% +Position the laser beam with close pin +after you connect it to batteries. Have + + align:start position:0% +after you connect it to batteries. Have + + + align:start position:0% +after you connect it to batteries. Have +the laser warm up for two + + align:start position:0% +the laser warm up for two + + + align:start position:0% +the laser warm up for two +minutes. Turn off the light and you + + align:start position:0% +minutes. Turn off the light and you + + + align:start position:0% +minutes. Turn off the light and you +should see the bean spot. The area + + align:start position:0% +should see the bean spot. The area + + + align:start position:0% +should see the bean spot. The area +should be larger than your holographic + + align:start position:0% + + + + align:start position:0% + +plate. Place your object in the middle + + align:start position:0% +plate. Place your object in the middle + + + align:start position:0% +plate. Place your object in the middle +of the beam. The object should be bright + + align:start position:0% +of the beam. The object should be bright + + + align:start position:0% +of the beam. The object should be bright +when illuminated with the red laser and + + align:start position:0% +when illuminated with the red laser and + + + align:start position:0% +when illuminated with the red laser and +it doesn't move or + + align:start position:0% +it doesn't move or + + + align:start position:0% +it doesn't move or +deform. You can place your holographic + + align:start position:0% +deform. You can place your holographic + + + align:start position:0% +deform. You can place your holographic +plate on the top of your object for 20 + + align:start position:0% +plate on the top of your object for 20 + + + align:start position:0% +plate on the top of your object for 20 +seconds. Don't touch the table during + + align:start position:0% +seconds. Don't touch the table during + + + align:start position:0% +seconds. Don't touch the table during +exposure. Any vibration will affect the + + align:start position:0% +exposure. Any vibration will affect the + + + align:start position:0% +exposure. Any vibration will affect the +quality of interferent fringes. + + align:start position:0% + + + + align:start position:0% + +developing and + + align:start position:0% + + + + align:start position:0% + +drying. Here we have a developer, water + + align:start position:0% +drying. Here we have a developer, water + + + align:start position:0% +drying. Here we have a developer, water +for rinsing, bleach, water for more + + align:start position:0% +for rinsing, bleach, water for more + + + align:start position:0% +for rinsing, bleach, water for more +rinsing, alcohol for drying, and a place + + align:start position:0% +rinsing, alcohol for drying, and a place + + + align:start position:0% +rinsing, alcohol for drying, and a place +to dry your holographic + + align:start position:0% + + + + align:start position:0% + +plate. Developing should be done in the + + align:start position:0% +plate. Developing should be done in the + + + align:start position:0% +plate. Developing should be done in the +dark to prevent a second exposure. + + align:start position:0% +dark to prevent a second exposure. + + + align:start position:0% +dark to prevent a second exposure. +Use your tweezers to dip the plate in + + align:start position:0% +Use your tweezers to dip the plate in + + + align:start position:0% +Use your tweezers to dip the plate in +the developer for 20 seconds until the + + align:start position:0% +the developer for 20 seconds until the + + + align:start position:0% +the developer for 20 seconds until the +plate turns black and rinse it in water + + align:start position:0% +plate turns black and rinse it in water + + + align:start position:0% +plate turns black and rinse it in water +for 1 minute. + + align:start position:0% + + + + align:start position:0% + +Place a rinsed hologram into the + + align:start position:0% +Place a rinsed hologram into the + + + align:start position:0% +Place a rinsed hologram into the +bleaching solution. Agitating until the + + align:start position:0% +bleaching solution. Agitating until the + + + align:start position:0% +bleaching solution. Agitating until the +play is completed clear. It takes up to + + align:start position:0% +play is completed clear. It takes up to + + + align:start position:0% +play is completed clear. It takes up to +1 minute. + + align:start position:0% + + + + align:start position:0% + +and then rinse it in water for 1 + + align:start position:0% + + + + align:start position:0% + +minute. Place the finished hologram in + + align:start position:0% +minute. Place the finished hologram in + + + align:start position:0% +minute. Place the finished hologram in +the wetting solution for 20 to 60 + + align:start position:0% +the wetting solution for 20 to 60 + + + align:start position:0% +the wetting solution for 20 to 60 +seconds. It reduce the likelihood of + + align:start position:0% +seconds. It reduce the likelihood of + + + align:start position:0% +seconds. It reduce the likelihood of +water spots and have it dry for 10 + + align:start position:0% +water spots and have it dry for 10 + + + align:start position:0% +water spots and have it dry for 10 +minutes. + + align:start position:0% + + + + align:start position:0% + +Testing view the hologram with + + align:start position:0% +Testing view the hologram with + + + align:start position:0% +Testing view the hologram with +incandescent light such as projector, + + align:start position:0% +incandescent light such as projector, + + + align:start position:0% +incandescent light such as projector, +flashlight, spotlight or LED in the sun. \ No newline at end of file diff --git a/pY9ol9So2Yw.txt b/pY9ol9So2Yw.txt new file mode 100644 index 0000000000000000000000000000000000000000..5dd3cf2b4a6c9cf3fe73047f139a3e5d381f4f06 --- /dev/null +++ b/pY9ol9So2Yw.txt @@ -0,0 +1,3411 @@ +The following content is +provided under a Creative + +Commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high quality educational +resources for free. + +To make a donation or view +additional materials from + +hundreds of MIT courses, visit +MIT OpenCourseWare at + +ocw.mit.edu. + +PROFESSOR: I'm going to spend +most of time talking about + +chapters one, two, and three. + +A little bit talking about +chapter four, because we've + +been doing so much with chapter +four in the last + +couple of weeks that you +probably remember that more. + +OK. + +The basics, which we started out +with, and which you should + +never forget, is that any time +you develop a probability + +model, you've got to specify +what the sample space is and + +what the probability measure +on that sample space is. + +And in practice, and in almost +everything we've talked about + +so far, there's really a basic +countable set of random + +variables which determine +everything else. + +In other words, when you find +the joint probability + +distribution on that set of +random variables, that tells + +you everything else +of interest. + +And a sample point or a sample +path on that set of random + +variables is in a collection of +sample values, one sample + +value for each random +variable. + +It's very convenient, especially +when you're in an + +exam and a little bit rushed, +to confuse random variables + +with the sample values for +the random variables. + +And that's fine. + +I just want to caution you +again, and I've done this many + +times, that about half the +mistakes that people make-- + +half of the conceptual mistakes +that people make + +doing problems and doing quizzes +are connected with + +getting confused at some point +about what's a random variable + +and what's a sample value +of that random variable. + +And you start thinking about +sample values as just numbers. + +And I do that too. + +It's convenient for thinking +about things. + +But you have to know that that's +not the whole story. + +Often, we have uncountable +sets of random variables. + +Like in renewal processes, we +have the counting renewal + +process, which typically has an +uncountable set of random + +variables, a number of arrivals +up to each time, t, + +where t is a continuous valued +random variable. + +But in almost all of those +cases, you can define things + +in terms of simpler sets of +random variables, like the + +interarrival times, +which are IID. + +Most of the processes we've +talked about really have a + +pretty simple description if +you look for the simplest + +description of them. + +If you have a sequence of +IID random variables-- + +which is what we have for +Poisson and renewal processes, + +and what we have for Markov +chains is not that much more + +complicated-- + +the laws of large numbers are +useful to specify what the + +long term behavior is. + +The sample time average is, as +we all know by now, is the sum + +of the random variables +divided by n. + +So it's a sample average +of these quantities. + +The random variable, which has +a main x bar, the expected + +value of x, that's +almost obvious. + +You just take the expected value +of s sub n, and it's n + +times the expected value of x +divided by n, and you're done. + +And the variance, since these +random variables are + +independent, you find that +almost as easily. + +That has this very +simple-minded + +distribution function. + +Remember, we usually work +with distribution + +functions in this class. + +And often, the exercises are +much easier when you do them + +in terms of the distribution +function than if you use + +formulas you remember from +elementary courses, which are + +specialized to-- + +which are specialized to +probability density and + +probability mass functions, and +often have more special + +conditions on them than that. + +But anyway, the distribution +function starts + +to look like this. + +As n gets bigger, you notice +that what's happening is that + +you get a distribution which +is scrunching in this way, + +which is starting to +look smoother. + +The jumps in it gets smaller. + +And you start out with this +thing which is kind of crazy. + +And by time, n is even 50. + +You get something which +almost looks like a-- + +I don't know how we tell +the difference + +between those two things. + +I thought we could, +but we can't. + +I certainly can't up there. + +But anyway, the one that's +tightest in is the one + +for n equals 50. + +And what these laws of large +numbers all say in some sense + +is that this distribution +function gets crunched in + +towards an impulse +at the mean. + +And then they say other more +specialized things about how + +this happens, about sample +paths and all of that. + +But the idea is that this +distribution function is + +heading towards a +unit impulse. + +The weak law of large numbers +then says that if the expected + +value of the magnitude of x +is less than infinity-- + +and usually when we talk about +random variables having a + +mean, that's exactly +what we mean. + +If that condition is not +satisfied, then we usually say + +that the random variable +doesn't have a mean. + +And you'll see that every time +you look at anything in + +probability theory. + +When people say the mean exists, +that's what they + +always mean. + +And what the theorem says then +is exactly what we were + +talking about before. + +The probability that the +difference between s n over n, + +and the mean of x bar, the +probability that it's greater + +than or equal to epsilon +equals 0 in the limit. + +So it's saying that you put +epsilon limits on that + +distribution function and let +n get bigger and bigger, it + +goes to 1 and 0. + +It says the probability of s n +over n, less than or equal to + +x, approaches a unit step as +n approaches infinity. + +This says this is the condition +for convergence in + +probability. + +What we're saying is that that +also means convergence and + +distribution function, and +distribution for this case. + +And then we also, when we got +to renewal processes, we + +talked about the strong +law of large numbers. + +And that says that the expected +value of x is finite. + +Then this limit approaches +x on a sample path basis. + +In other words, for every sample +path, except this set + +of probability 0, this +condition holds true. + +That doesn't seem like it's +very different or very + +important for the time being. + +But when we started studying +renewal processes, which is + +where we actually talked about +this, we saw that in fact, it + +let us talk about this, which +says that if you take any + +function of s n over n-- + +in other words, a function +of a real value-- + +a function of a-- + +a real valued function of a-- + +a real valued function +of a real value, yes. + +What you get is that +same function + +applied to the mean here. + +And that's the thing +which is so + +useful for renewal processes. + +And it's what usually makes +the strong law of large + +numbers so much easier to +use than the weak law. + +That's a plug for +the strong law. + +There are many extensions of the +week love telling how fast + +the convergence is. + +One thing you should always +remember about the central + +limit theorem, is it really +tells you something about the + +weak law of large numbers. + +It tells you how fast that +convergence is and what the + +convergence looks like. + +It says that if the variance +of this underlying random + +variable is finite, then this +limit here is equal to the + +normal distribution function, +the Gaussian at + +variance 1 and mean 0. + +And that becomes a little easier +to see what it's saying + +if you look at it this way. + +It says probability that s +n over n minus x bar-- + +namely the difference between +the sum and the mean which + +it's converging to-- + +the probability that that's less +than or equal to y sigma + +over square root of +n is this normal + +Gaussian random variable. + +It says that as n gets bigger +and bigger, this quantity here + +gets tighter and tighter. + +What it says in terms of the +picture here, in terms of this + +picture, it says that as n gets +bigger and bigger, this + +picture here scrunches down as +1 over the square root of n. + +And it also becomes Gaussian. + +| it tells you exactly what +kind of convergence you + +actually have here. + +Is not only saying that this +does converge to a unit step. + +It says how it converges. + +And that's a nice thing, +conceptually. + +You don't always need +it in problems. + +But you need it for +understanding what's going on. + +We're moving backwards, +it seems. + +Now, 1, 2, Poisson processes. + +We talked about arrival +processes. + +You'd almost think that all +processes are arrival + +processes at this point. + +But any time you start to think +about that, think of a + +Markov chain. + +And a Markov chain is not an +arrival process, ordinarily. + +Some of them can be +viewed that way. + +But most of them can't. + +An arrival processes +is an increasing + +sequence of random variables. + +0 less than s1, which is the +time of the first arrival, s2, + +which is a time of the second +arrival, and so forth. + +Interarrival times are x1 equals +s1, and x i equals s i + +minus s i minus 1. + +The picture, which you should +have indelibly printed on the + +back of your brain someplace +by this time, is + +this picture here. + +s1, s2, s3, are the times +at which arrivals occur. + +These are random variables, so +these arrivals come in at + +random times. + +x1, x2, x3 are the intervals +between arrivals. + +And N of t is the number of +arrivals that have occurred up + +until time t. + +So every time the t passes one +of these arrival times, N of t + +pops up by one, pops up by one +again, pops up by one again. + +The sample value +pops up by one. + +Arrival process can model +arrivals to a queue, + +departures from a queue, +locations of breaks in an oil + +line, an enormous number +of things. + +It's not just arrivals +we're talking about. + +It's all of these other +things, also. + +But it's something laid out on +a one-dimensional axis where + +things happen at various +places on that + +one-dimensional axis. + +So that's the way to view it. + +OK, same picture again. + +Process can be specified by the +joint distribution of the + +arrival epochs or the +interarrival times, and, in + +fact, of the counting process. + +If you see a sample path of +the counting process, then + +from that you can determine the +sample path of the arrival + +times and the sample path of +the interarrival times. + +And since any set of these +random variables specifies all + +three of these things, the +three are all equivalent. + +OK, we have this important +condition here. + +And I always sort of forget +this, but when these arrivals + +are highly delayed, when there's +a long period of time + +between each arrival, what that +says is the accounting + +process is getting small. + +So big interarrival times +corresponds to a small + +value of N of t. + +And you can see that in +the picture here. + +If you spread out these +arrivals, you make s1 all the + +way out here. + +Then N of t doesn't become +1 until way out here. + +So N of t as a function of t is +getting smaller as s sub n + +is getting larger. + +S sub n is the minimum of the +set of t, such that N of t is + +greater than or equal to N. +Sounds like a unpleasantly + +complicated expression. + +If any of you can find a simpler +way to say it than + +that, I would be absolutely +delighted to hear it. + +But I don't think there is. + +I think the simpler way to say +it is this picture here. + +And the picture says it. + +And you can sort of figure out +all those logical statements + +from the picture, which +is intuitively a + +lot clearer, I think. + +So now, renewal processes is +an arrival process with IID + +interarrival times. + +And a Poisson process is a +renewal process where the + +interarrival random variables +are exponential. + +So, Poisson process +is a special + +case of renewal process. + +Why are these exponential +interarrival + +arrival times so important? + +Well, it's because they're +memoryless. + +And the memoryless property says +that the probability that + +x is greater than t plus x is +equal to the probability that + +it's greater than x times the +probability that it's greater + +than t for all x and t greater +than or equal to 0. + +This makes better sense if +you say it conditionally. + +The probability that x is +greater than t plus x, given + +that it's greater than t, is +the same as the probability + +that x is greater that-- + +capital X is greater +than little x. + +This really gives you +the memoryless + +property in a nutshell. + +It says if you're looking at +this process as it evolves, + +and you see an arrival, and then +you start looking for the + +next arrival, it says that no +matter how long you've been + +looking, the distribution +function, as the time to wait + +until the next arrival, +is the same + +exponential random variable. + +So you never gain anything +by waiting. + +You might as well +be impatient. + +But it doesn't do any good +to be impatient. + +Doesn't to any good to wait. + +It doesn't do any good +to not wait. + +No matter what you do, this +damn thing always takes an + +exponential amount +of time to occur. + +OK, that's what it means +to be memoryless. + +And the exponential is the only + +memoryless random variable. + +How about a geometric +random variable? + +The geometric random variable +is memoryless if you're only + +looking at integer times. + +Here we're talking about +times on a continuum. + +That's what this says. + +Well, that's what this says. + +And if you look at discrete +times, then a geometric random + +variable is memoryless also. + +We're given a Poisson +of rate lambda. + +The interval from any given t +greater than 0 until the first + +arrival after t is a +random variable. + +Let's call it z1. + +We already said that that +random variable was + +exponential. + +And it's independent of all +arrivals which occur before + +that starting time t. + +So looking at any starting +time t, doesn't make any + +difference what has happened +back here. + +That's not only the +last arrival, but + +all the other arrivals. + +The time until the next arrival +is exponential. + +The time until each arrival +after that is exponential + +also, which says that if you +look at this process starting + +at time t, it's a Poisson +process again, where all the + +times have to be shifted, of +course, but it's a Poisson + +process starting at time t. + +The corresponding counting +process, we can call it n + +tilde of t and tau, where tau is +greater than or equal to t, + +where this is the number of +arrivals in the original + +process up until time tau minus +the number of arrivals + +up until time t. + +If you look at that difference, +so many arrivals + +up until t, so many more +up until time tau. + +You look at the difference +between tau and t. + +The number of arrivals in that +interval is the same Poisson + +distributing random +variable again. + +So, it has the same +distribution as N + +of tau minus t. + +And that's called the stationary +increment property. + +It says that no matter where you +start a Poisson process, + +it always looks exactly +the same. + +It says that if you wait for one +hour and start then, it's + +exactly the same as what +it was before. + +If we had Poisson processes in +the world, it wouldn't do any + +good to travel on certain days +rather than other days. + +It wouldn't do any good to leave +to drive home at one + +hour rather than another hour. + +You'd have the same travel +all the time. + +It's all equal. + +It would be an awful world +if it were stationary. + +The independent increment +properties for counting + +process is that for all +sequences of ordered times-- + +0 less than t1 less than +t2 up to t k-- + +the random variables n of t1-- + +and now we're talking about the +number of arrivals between + +t1 and t2, the number +of arrivals between + +n minus 1 and tn. + +These are all independent +of each other. + +That's what this independent +increment property says. + +And we see from what we've said +about this memoryless + +property that the Poisson +process does indeed have this + +independent increment +property. + +Poisson processes have both the +stationary and independent + +increment properties. + +And this looks like an immediate +consequence of that. + +It's not. + +Remember, we had to struggle +with this for a bit. + +But it says plus Poisson +processes can be defined by + +the stationary and independent +increment properties, plus + +either the Poisson PMF for N +of t, or this incremental + +property, the probability that N +tilde of t and t plus delta, + +and the number of arrivals +between t and t plus delta, + +the probability that that's +1 is equal to + +lambda times delta. + +In other words, this view of a +Poisson process is the view + +that you get when you sort +of forget about time. + +And you think of arrivals from +outer space coming down and + +hitting on a line. + +And they hit on that +line randomly. + +And each one of them +is independent + +of every other one. + +And that's what you get if you +wind up with a density of + +lambda arrivals per unit time. + +OK, we talked about all +of that, of course. + +The probability distributions-- + +there are many of them for +a Poisson process. + +The Poisson process is +remarkable in the sense that + +anything you want to find, +there's generally a simple + +formula for it. + +If it's complicated, you're +probably not looking at + +it the right way. + +So many things come out +very, very simply. + +The probability-- + +the joint probability +distribution of all of the + +arrival times up until time N is +an exponential just in the + +last one, which says that the +intermediate arrival epochs + +are equally likely to be +anywhere, just as long as they + +satisfy this ordering +restriction, s1 less than s2. + +That's what this formula says. + +It says that the joint density +of these arrival times doesn't + +depend on anything except the +time of the last one. + +But it does depend on the fact +that they're [INAUDIBLE]. + +From that, you can find +virtually everything else if + +you want to. + +That really is saying exactly +the same thing as we were just + +saying a while ago. + +This is the viewpoint of looking +at this line from + +outer space with arrivals coming +in, coming in uniformly + +distributed over this line +interval, and each of them + +independent of each other one. + +That's what you wind +up saying. + +This density, then, of the +n-th arrival, if you just + +integrate all this stuff, you +get the Erlang formula. + +Probability of arrival n in +t to t plus delta is-- + +now this is the derivation that +we went through before, + +going from Erlang to Poisson. + +You can go from Poisson to +Erlang too, if you want to. + +But it's a little easier +to go this way. + +The probability of arrival in +t to t plus delta is the + +probability that n of t is +equal to n minus 1 times + +lambda delta plus an o +of delta, of course. + +And the probability that n of +t is equal to n minus 1 from + +this formula here is going to be +the density of when s sub n + +appears, divided by lambda. + +That's exactly what this +formula here says. + +So that's just the Poisson +distribution. + +We've been through +that derivation. + +It's almost a derivation worth +remembering, because it just + +appears so often. + +As you've seen from the problem +sets we've done, + +almost every problem you can +dream of, dealing with Poisson + +processes, the easy way to do +them comes from this property + +of combining and splitting +Poisson processes. + +It says if n1 of t, n2 of t, +up to n sub k of t are + +independent Poisson +processes-- + +what do you mean by +a process being + +independent of another process? + +Well, the process is specified +by the interarrival times for + +that process. + +So what we're saying here is the +interarrival times for the + +first process are independent +of the interarrival times of + +the second process, +independent of the + +interarrival times for the third +process, and so forth. + +Again, this is a view of someone +from outer space, + +throwing darts onto a line. + +And if you have multiple people +throwing darts on a + +line, but they're all equally +distributed, all uniformly + +distributed over the line, +this is exactly + +the model you get. + +So we have two views here. + +The first one is to look at +the arrival epochs that's + +generated from each process. + +And then combine all arrivals +into one Poisson process. + +So we look at all these Poisson +processes, and then + +take the sum of them, and we +get a Poisson process. + +The other way to look at it-- + +and going back and forth between +these two views is the + +way you solve problems-- + +you look at the combined +sequence of + +arrival epochs first. + +And then for each arrival that +comes in, you think of an IID + +random variable independent +of all the other random + +variables, which decides for +each arrival which of the + +sub-processes it goes to. + +So there's this hidden +process-- + +well, it's not hidden. + +You can see what it's doing +from looking at all the + +sub-processes. + +And each arrival then is +associated with the given + +sub-process, with the +probability mass function + +lambda sub i over the +sum of lambda sub j. + +So this is the workhorse +of Poisson + +type queueing problems. + +You study queuing theory, +every page, you + +see this thing used. + +If you look at Kleinrock's books +on queueing, they're + +very nice books because they +cover so many different + +queueing situations. + +You find him using this +on every page. + +And he never tells you that he's +using it, but that's what + +he's doing. + +So that's a useful +thing to know. + +We then talked about conditional +arrivals and order + +statistics. + +The conditional distribution +of the N first arrivals-- + +namely, s sub 1 s sub +2 up to s sub n-- + +given the number of arrivals in +N of t is just n factorial + +over t to the n. + +Again, it doesn't depend on +where these arrivals are. + +It's just a function which is +independent of each arrival. + +It's the same kind of +conditioning we had before. + +It's n factorial divided +by t to the n. + +Because of the fact that if +you order these random + +variables, t1 less than t2 less +than t3, and so forth, up + +until time t, and then you say +how many different ways can I + +arrange a set of numbers, each +between 0 and t so that we + +have different orderings +of them. + +And you can choose any one +of the N to be the first. + +You can choose any one +of the remaining n + +minus 1 to be the second. + +And that's where this is n +factorial comes from here. + +And that, again we've +been over. + +The probability that s1 is +greater than tau, given that + +they're interarrivals in the +overall interval t, comes from + +just looking at N uniformly +distributed random variables + +between 0 and t. + +And then what do you do with +those uniformly distributed + +random variables? + +Well, you ask the question, +what's the probability that + +all of them occur +after time tau? + +And that's just t minus tau +divided by t raised to the + +n-th power. + +And see, all of these formulas +just come from particular + +viewpoints about what's +going on. + +You have a number +of viewpoints. + +One of them is throwing +darts at a line. + +One of them is having +exponential + +interarrival times. + +One of them is these uniform +interarrivals. + +It's only a very small +number of tricks. + +And you just use them in +various combinations. + +So the joint distribution of s1 +to s n, given N of t equals + +n, is the same as the joint +distribution of N uniform + +random variables after +they've been ordered. + +So let's go on to finite +state Markov chains. + +Seems like we're covering an +enormous amount of material in + +this course. + +And I think we are. + +But as I'm trying to say, as +we go along, it's all-- + +I mean, everything follows from +a relatively small set of + +principles. + +Of course, it's harder to +understand the small set of + +principles and how to apply them +than it is to understand + +all the details. + +But that's-- + +but on the other hand, if you +understand the principles, + +then all those details, +including the ones we haven't + +talked about, are easy +to deal with. + +An integer-time stochastic +process-- + +x1, x2, x3, blah, blah, blah-- + +is a Markov chain if for all n, +namely the number of them + +that we're looking at-- + +well-- + +for all n, i, j, k, l, and so +forth, the probability that + +the n-th of these random +variables is equal to j, given + +what all of the others are-- and +these are not ordered now. + +I mean, in a Markov chain, +nothing is ordered. + +We're not talking about +an arrival process. + +We're just talking about a frog +jumping around on lily + +pads, if you arrange the lily +pads in a linear way, if these + +are random variables. + +The probability that the n-th +location is equal to j, given + +that the previous locations are +i, k, back to m, is just + +some probability p sub +i j, a conditional + +probability of j given i. + +In other words, once if you're +looking at what happens at + +time n, once you know what +happened at time n minus 1, + +everything else is +of no concern. + +This process evolves by having +a history of only one time + +unit, a little like the +Poisson process. + +The Poisson process evolves +by being totally + +independent of the past. + +Here, you put a little +dependence in the past. + +But the dependence is only to +look at the last thing that + +happened, and nothing before the +last time that happened. + +So p sub i j depends +only on i and j. + +And the initial probability mass +function is arbitrary. + +Markov chain is finite-state if +the sample space for each x + +i, as a finite set S. And the +sample space S is usually + +taken to be integers +1 up to M. + +In all these formulas we write, +we're always summing + +from one to M. And the reason +for that is we've assumed the + +states are 1, 2, 3, up to M. +Sometimes it's more convenient + +to think of different +state spaces. + +But all the formulas +we use are based on + +this state space here. + +Markov up chain is completely +described by these transition + +probabilities plus the initial +probabilities. + +If you want to write down the +probability of what x is this + +some time N given what was at +some time 0, all you have to + +do is trace all the paths from +0 out to N, add up the + +probabilities of all of those +paths, and that tells you the + +probability you want. + +All probabilities and be +calculated just from knowing + +what these transition +probabilities are. + +Note that when we're dealing +with Poisson processes, we + +defined everything in +terms of how many-- + +how many variables are there in +defining a Poisson process? + +How many things do you have to +specify before I know exactly + +what Poisson process +I'm talking about? + +Only the Poisson rate. + +Only one parameter is necessary + +for a Poisson process. + +For a finite-state Markov +process, you need a lot more. + +What you need is all of these +values, p sub i j. + +If you sum p sub i j over +j, you have to get 1. + +So that removes one of them. + +But as soon as you specify that +transition matrix, you've + +specified everything. + +So there's nothing more to know + +about the Poisson process. + +There's only all these gruesome +derivations that we + +go through. + +But everything is initially +determined. + +Set of transition probabilities +is usually + +viewed as the Markov chain. + +And the initial probabilities +are usually viewed as just a + +parameter that we deal with. + +In other words, we-- + +in other words, what we study +is the particular Markov + +chain, whether it's recurrent, +whether it's transient, + +whatever it is. + +How you break it up into +classes, all of that stuff + +only depends on these transition +probabilities and + +doesn't depend on +where you start. + +Now, a finite-state Markov chain +can be described either + +as a directed graph +or as a matrix. + +I hope you've seen by this +time that some things are + +easier to look at if you look at +things in terms of a graph. + +Some things are easier to look +at if you look at something + +like this matrix. + +And some problems can be solved +by inspection, if you + +draw a graph of it. + +Some can be solved almost +by inspection if + +you look at the matrix. + +If you're doing things by +computer, usually computers + +deal with matrices more easily +than with graphs. + +If you're dealing with a Markov +chain with 100,000 + +states, you're not going to +look at the graph and + +determine very much from it, +because it's typically going + +to be fairly complicated-- + +unless it has some very +simple structure. + +And sometimes that simple +structure is determined. + +If it's something where +you can only-- + +where you have the states +numbered from 1 to 100,000, + +and you can only go from state +i to state i plus 1, or from + +state i to i plus 1, or +i minus 1, then it + +becomes very simple. + +And you like to look at +it as a graph again. + +But ordinarily, you don't +like to do that. + +But the nice thing about this +graph is that it tells you + +very simply and visually which +transition probabilities are + +zero, and which transition +probabilities are non-zero. + +And that's the thing that +specifies which states are + +recurrent, which states are +transient, and all of that. + +All of that kind of elementary +analysis about a Markov chain + +all comes from looking at this +graph and seeing whether you + +can get from one state to +another state by some process. + +So let's move on from that. + +Talk about the classification +of states. + +We started out with the +idea of a walk and + +a path and a cycle. + +I'm not sure these terms are +uniform throughout the field. + +But a walk is an ordered +string of nodes, like + +i0, i1, up to i n. + +You can have repeated elements +here, but you need a directed + +arc from i sub n minus +1 to i sub m. + +Like for example, in this stupid +Markov chain here-- + +I mean, when you're drawing +things is LaTeX, it's kind of + +hard to draw those nice +little curves there. + +And because of that, when you +once draw a Markov chain, you + +never want to change it. + +And that's why these nodes +have a very small set of + +Markov chains in them. + +It's just to save me some work, +drawing and drawing + +these diagrams. + +An example of a walk, as you +start in 4, you take the self + +loop, go back to 4 at time 2. + +Then you go to state +1 at time 3. + +Then you go to state +2 at time 4. + +Then you go to stage +3, time 5. + +And back to state 2 at time 6. + +You have repeated nodes there. + +You have repeated nodes +separated here. + +Another example of a +walk is 4, 1, 2, 3. + +Example of a path, the path +can't have any repeated nodes. + +We'd like to look at paths, +because if you're going to be + +able to get from one node to +another node, and there's some + +walk that goes all around the +place and gets to that final + +node, there's also path +that goes there. + +If you look at the walk, you +just leave that all the cycles + +along the way, and +you get to the n. + +And a cycle, of course, which I +didn't define, is something + +which starts at one node, goes +through a path, and then + +finally comes back to the same +node that it started at. + +And it doesn't make any +difference for the cycle 2, 3, + +2 whether you call it +2, 3, 2 or 3, 2, 3. + +That's the same cycle, and +it's not even worth + +distinguishing between +those two ideas. + +OK That's that. + +If there's a path from-- + +where did I-- + +node j is accessible from i, +which we abbreviate as i + +has a path to j. + +If there's a walk from i to +j, which means that p + +sup i j to the n-- + +this is the transition +probability, the probability + +that x sub n is equal to +j, given that x sub + +0 is equal to i. + +And we use this all the time. + +If this is greater than zero +for some n greater than 0. + +In other words, j is accessible +from i if there's a + +path from i that goes to j. + +And trivially, if i go to j, and +there's a path from j to + +k, then there has to be +a path from i to k. + +If you've ever tried to make up +a mapping program to find + +how to get from here to there, +this is one of the most useful + +things you use. + +If there's a way to get here +to there, and a way to get + +from here to there, then there's +a way to get from here + +all the way to the end. + +And if you look up what most of +these map programs do, you + +see that they overuse this +enormously and they wind up + +taking you from here to there +by some bizarre path just + +because it happens to go through +some intermediate node + +on the way. + +So two nodes communicate-- + +i double arrow j-- + +if j is accessible from i, and +if i is accessible from j. + +That means there's a path from +i to j, and another path from + +j back to i, if you shorten +them as much as you can. + +There's a cycle. + +It starts at i, goes through j, +and comes back to i again. + +I didn't say that quite right, +so delete that from what + +you've just heard. + +A class C of states as a +non-empty set, such that i and + +j communicate for each +i j in this class. + +But i does not communicate +with j for each i and C-- + +for i and C and j, not in C. + +The convenient way to think +about this-- and I should have + +stated this as a theorem in +the notes, because it's-- + +I think it's something that +we all use without even + +thinking about it. + +It says that the entire set of +states, or the entire set of + +nodes in a graph, is partitioned +into classes. + +The class C, containing, is i +in union with all of the j's + +that communicate with i. + +So if you want to find this +partition, you start out with + +an arbitrary node, you find all +of the other nodes that it + +communicates with, and you +find them by picking + +them one at a time. + +You pick all of the nodes +for which p sub i j is + +greater than 0. + +Then you pick-- + +and p sub j i is great-- + +well-- blah. + +If you want to find the set of +nodes that are accessible from + +i, you start out looking at i. + +You look at all the states +which are accessible + +from i in one step. + +Then you look at all the steps, +all of the states, + +which you can access from +any one of those. + +Those are the states which are +accessible in two states-- + +in two steps, then in three +steps, and so forth. + +So you find all the nodes that +are accessible from node i. + +And then you turn around and +do it the other way. + +And presto, you have all of +these classes of states all + +very simply. + +For finite-state change, the +state i is transient if + +there's a j in S such that +i goes into j, but j + +does not go into i. + +In other words, if I'm a state +i, and I can get to you, but + +you can't get back to me, +then I'm transient. + +Because the way Markov chains +work, we keep going from one + +step to the next step to the +next step to the next step. + +And if I keep returning to +myself, then eventually I'm + +going to go to you. + +And once I go to you, I'll +never get back again. + +So because of that, these +transient states are states + +where eventually you +leave them and you + +never get back again. + +As soon as we start talking +about countable state Markov + +chains, you'll see that +this definition + +doesn't work anymore. + +You can-- + +it is very possible to just +wander away in a countable + +state Markov chain, and you +never get back again that way. + +After you wander away too far, +the probability of getting + +back gets smaller and smaller. + +You keep getting further +and further away. + +The probability of returning +gets smaller and smaller, so + +that you have transience +that way also. + +But here, the situation is +simpler for a finite-state + +Markov chain. + +And you can define transience if +there's a j in S such that + +i goes into j, but j +doesn't go into i. + +If i's not transient, +then it's recurrent. + +Usually you define recurrence +first and transience later, + +but it's a little simpler +this way. + +All states in a class are +transient, or all are + +recurrent, and a finite-state +Markov chain contains at least + +one recurrent class. + +You did that in your homework. + +And you were surprised at how +complicated it was to do it. + +I hope that after you wrote +down a proof of this, you + +stopped and thought about what +you were actually proving, + +which intuitively is something +very, very simple. + +It's just looking at all of +the transient classes. + +Starting at one transient +class, you + +find if there's another-- + +if there's another state you can +get to from OK i which is + +also transient, and then you +find if there's another state + +you get to from there which +is also transient. + +And eventually, you have to come +to a state from which you + +can't go to some other state, +from which you can't get back. + +That was explaining it almost +as badly as the problem + +statement explained it. + +And I hope that after you did +the problem, even if you can't + +explain it to someone, +you have an + +understanding of why it's true. + +It shouldn't be surprising +after you do that. + +So the finite-state Markov chain +contains at least one + +recurrent class. + +OK, the period of a state +i as the greatest common + +denominator of n, such that +p i n is greater than 0. + +Again, a very complicated +definition for a + +simple kind of idea. + +Namely, you start out +in a state i. + +You look at all of the times at +which you can get back to + +state i again. + +If you find it that set of +times has a period in it, + +namely, if every sequences of +states is a multiple of some + +d, then you know that the state +is periodic if d is + +greater than 1. + +And what you have to do is to +find the largest such number. + +And that's the period +of the state. + +All states in the same class +have the same period. + +A recurring class with period +d greater than one can be + +partitioned into sub-class-- + +this is the best way +of looking at + +periodic classes of states. + +If you have a periodic class of +states, then you can always + +separate it into +d sub-classes. + +And in such a set of +sub-classes, transitions from + +S1 and the states in +S1 only go to S2. + +Transitions from states +in S2 only go to S3. + +Up to, transitions from S +d only go back to S1. + +They have to go someplace, +so they go back to S1. + +So as you cycle around, it takes +d steps to cycle from 1 + +back to 1 again. + +It takes d steps to cycle +from 2 back to 2 again. + +So you can see the structure of +the Markov chain and why, + +in fact, it does have to be-- + +why that class has +to be periodic. + +An ergodic class is a recurrent +aperiodic class. + +In other words, it's a class +where the period is equal to + +1, which means there really +isn't any period. + +A Markov chain with only one +class is ergodic if the class + +is ergodic. + +And the big theorem here-- + +I mean, this is probably the +most important theorem about + +finite-state Markov chains. + +You have an ergodic, +finite-state Markov chain. + +Then the limit as n goes to +infinity of the probability of + +arriving in state j after n +steps, given that you started + +in state i, is just some +function of j. + +In other words, when n gets very +large, it doesn't depend + +on how large M is. + +It stays the same. + +It becomes independent of n. + +It doesn't depend on +where you started. + +No matter where you start +in a finite-state + +ergodic Markov chain. + +After a very long time, the +probability of being in a + +state j is independent of where +you started, and it's + +independent of how long +you've been running. + +So that's a very strong +kind of-- + +it's a very strong kind +of limit theorem. + +It's very much like the law of +large numbers and all of these + +other things. + +I'm going to talk a little bit +at the end about what that + +relationship really is. + +Except what it says is, after a +long time, you're in steady + +state, which is why +it's called the + +steady state theorem. + +Yes? + +AUDIENCE: Could you define the +steady states for periodic + +changes [INAUDIBLE]? + +PROFESSOR: I try to avoid doing +that because you have + +steady state probabilities. + +The steady state probabilities +that you have are, you take-- + +is if you have these +sub-classes. + +Then you wind up with a steady +state within each sub-class. + +If you assign a probability +of the probability in the + +sub-class, divided by d, then +you get what is the steady + +state probability. + +If you start out in that steady +state, then you're in + +each sub-class with probability +1 over d. + +And you shift to the next +sub-class and you're still in + +steady state, because you have +a probability, 1 over d, of + +being in each of those +sub-classes to start with. + +You shift and you're still in +one of the sub-classes with + +probability 1 over d. + +So there still is a steady +state in that sense, but + +there's not a steady state +in any nice sense. + +So anyway, that's +the way it is. + +But you see, if you understand +this theorem for ergodic + +finite state and Markov +chains, and then you + +understand about periodic +change and this set of + +sub-classes, you can +see within each + +sub-class, if you look at-- + +if you look at-- + +if you look at time 0, time d, +time 2d, times 3d and 4d, then + +whatever state you start in, +you're going to be in the same + +class after d steps, the same +class after 2d steps. + +You're going to have +a transition + +matrix over d steps. + +And this theorem still applies +to these sub-classes over + +periods of d. + +So the hard part of it +is proving this. + +After you prove this, then you +see that the same thing + +happens over each sub-class +after that. + +That's a pretty major theorem. + +It's difficult to prove. + +A sub-step is to show that for +an ergodic M state Markov + +chain, the probability of being +in state j at time n, + +given that you're in state i at +time 0, is positive for all + +i j, and all n greater than +M minus 1 squared plus 1. + +It's very surprising that you +have to go this many states-- + +this many steps before you get +to the point that all these + +transition probabilities +are positive. + +You look at this particular kind +of Markov chain in the + +homework, and I hope what you +found out from it was that if + +you start, say, in state two, +then at the next time, you + +have to be in 3. + +Next time, you have to be in +4, you have to be in 5, you + +have to be in 6. + +In other words, the size of +the set that you can be in + +after one step is just 1. + +One possible state here, one +possible state here, one + +possible state here. + +The next step, you're in either +1 or 2, and as you + +travel around, the size of the +set of states you can be in at + +these different steps, is 2, +until you get all the way + +around again. + +And then there's +a way to get-- + +when you get to state 6 again, +the set of states enlarges. + +So finally you get up to a +set of states, which is + +up to M minus 1. + +And that's why you get the M +minus 1 squared here, plus 1. + +And this is the only Markov +chain there is. + +You can have as many +states going around + +here as you want to. + +But you have to have this +structure at the end, where + +there's one special state and +one way of circumventing it, + +which means there's one cycle +of size M minus 1, and one + +cycle of size M. And that's the +only way you can get it. + +And that's the only Markov chain +that meets this bound + +with equality. + +In all other cases, you get this +property much earlier. + +And often, you get it after just +a linear amount of time. + +The other part of this major +theorem that you reach steady + +state says, let P be +greater than 0. + +In other words, let +all the transition + +probabilities be positive. + +And then define some quantity +alpha as a minimum of the + +transition probabilities. + +And then the theorem says, for +all states j and all n greater + +than or equal to 1, the maximum +over the initial + +states minus the minimum over +the initial states of P sub i + +j to the n plus-- first step, +that difference is less than + +or equal to the difference +a the n-th step, + +times 1 minus 2 alpha. + +Now 1 minus 2 alpha is +as a positive number. + +And this says that this maximum +minus minimum is 1 + +minus 2 alpha to the n, which +says that the limit of the + +maximizing term is equal +to the limit of + +the minimizing term. + +And what does that say? + +It says that everything in the +middle gets squeezed together. + +And it says exactly what we want +it to say, that the limit + +of P sub l j to the n is +independent of l, after n gets + +very large. + +Because the maximum and +the minimum get very + +close to each other. + +We also showed that [? our ?] +approaches that limit + +exponentially. + +That's what this says. + +The exponent here is just this +alpha, determined in that way. + +And the theorem for ergodic +Markov chains then follows by + +just looking at successive h +steps in the Markov chain when + +h is large enough so that all +these transition probabilities + +are positive. + +So you go out far enough +that all the transition + +probabilities are positive. + +And then you look at repetitions +of that, and apply + +this theorem. + +And suddenly you have this +general theorem, + +which is what we wanted. + +An ergodic unichain is a Markov +up chain with one + +ergodic recurring class, +plus perhaps a set + +of transient states. + +And most of the things we talk +about in this course are for + +unichains, usually ergodic +unichains, because if you have + +multiple recurrent classes, +it just makes a mess. + +You wind up in this recurrent +class, or + +this recurrent class. + +And aside from the question of +which one you get to, you + +don't much care about it. + +And the theorem here is for an +ergodic finite-state unichain. + +The limit of P sub i j to the +n probability of being in + +state j at time n, given that +you're in state i at time 0, + +is equal to pi sub j. + +In other words, this limit +here exists for all i j. + +And the limit is independent +of i. + +And it's independent of n +as n gets big enough. + +And then also, we can choose +this so that this set of + +probabilities here satisfies +this, what's called the steady + +state condition, the sum +of pi i times P sub i j + +is equal to pi j. + +In other words, if you start out +in steady state, and you + +look at the probabilities of +being in the different states + +at the next time unit, this is +the probability of being in + +state j at time n plus 1, if +this is the probability of + +being in state i at time n. + +So that condition +gets satisfied. + +That condition is satisfied. + +You just stay in steady +state forever. + +And pi i has to be positive for +a recurrent i, and pi i is + +equal to 0 otherwise. + +So this is just a +generalization + +of the ergodic theorem. + +And this is not what people +refer to as the ergodic + +theorem, which is a much more +general theorem than this. + +This is the ergodic theorem for +the case of finite state + +Markov chains. + +You can restate this in matrix +form as the limit of the + +matrix P to the n-th power. + +What I didn't mention here and +what I probably didn't mention + +enough in the notes is +that P sub i j-- + +but also, if you take the matrix +P times P time P, n + +times, namely, you take the +matrix, P to the n. + +This says the P sub i j +is the i j element. + +I'm sure all of you know that +by now, because you've been + +using it all the time. + +And what this says here-- + +what we've said before is that +every row of this matrix, P to + +the n, is the same. + +Every row is equal to pi. + +P to the n tends to a matrix +which is pi 1, pi 2, + +up to pi sub n. + +Pi 1, pi 2, up to pi sub n. + +Pi 1, pi 2, up to pi sub n. + +And the easiest way to express +this is the vector e times pi, + +where e is transposed. + +In other words, if you take a +column matrix, column 1, 1, 1, + +1, 1, and you multiply this by +a row vector, pi 1 times pi + +sub n, what you get is, for this +first row multiplied by + +this, this gives you-- + +well, in fact, if you +multiply this out, + +this is what you get. + +And if you've never gone through +the trouble of seeing + +that this multiplication leads +to this, please do it, because + +it's important to notice +that correspondence. + +We got specific results by +looking at the eigenvalues and + +eigenvectors of stochastic +matrices. + +And a stochastic matrix is the +matrix of a Markov chain. + +So some of these things +are sort of obvious. + +Lambda is an eigenvalue of P, if +and only if P minus lambda + +i is singular. + +This set of relationships +is not obvious. + +This is obvious linear +algebra. + +This is something that when +you study eigenvalues and + +eigenvectors in linear algebra, +you recognize that + +this is a summary of +a lot of things. + +If and only if this determinant +is equal to 0, + +which is true if and only if +there's some vector nu for + +which P times nu equals lambda +times nu for nu unequal to 0. + +And if and only if pi P equals +lambda pi for some + +pi unequal to 0. + +In other words, if this +determinant is equal to 0, it + +means that the matrix P minus +lambda i is singular. + +If the matrix is singular, there +has to be some solution + +to this equation here. + +There has to be some +solution to this + +left eigenvector equation. + +Now, once you see this, you +notice that e is always a + +right eigenvector of P. Every +stochastic matrix in the world + +has the property that e is a +right eigenvector of it. + +Why is that? + +Because all of the rows of a +stochastic matrix sum to 1. + +If you start off in state i, the +sum of the possible states + +you can be at in the next +step is equal to 1. + +You have to go somewhere. + +So e is always a right +eigenvector of P with + +eigenvalue 1. + +Since e is also is a right +eigenvector of P with + +eigenvalue 1, we go up here. + +We look at these if and +only if statements. + +We see, then, P must +be singular. + +And then pi times P +equals lambda pi. + +So no matter how many recurrent +classes we have, no + +matter what periodicity we have +in each of them, there's + +always a solution to pi +times P equals pi. + +There's always at least one +steady state vector. + +This determinant has an M-th +degree polynomial in lambda. + +M-th degree polynomials +have M roots. + +They aren't necessarily +distinct. + +The multiplicity of an +eigenvalue is the number roots + +of that value. + +And the multiplicity +of lambda equals 1. + +How many different roots +are there which have + +lambda equals 1? + +Well it turns out to be just +the number of recurrent + +classes that you have. + +If you have a bunch of recurrent +classes, within each + +recurring class, there's a +solution to pi P equals pi, + +which is non-zero only one +that recurrent class. + +Namely, you take this huge +Markov chain and you say, I + +don't care about any +of this except this + +one recurrent class. + +If we look at this one recurrent +class, and solve for + +the steady state probability in +that one recurrent class, + +then we get an eigenvector +which is non-zero on that + +class, 0 everywhere else, that +has an eigenvalue 1. + +And for every other recurrent +class, we + +get the same situation. + +So the multiplicity of lambda +equals 1 is equal to the + +number of recurrent classes. + +If you didn't get that proof +on the fly, it gets + +proved in the notes. + +And if you don't get the proof, +just remember that + +that's the way it is. + +For the special case where all +M eigenvalues are distinct, + +the right eigenvectors are +linearly independent. + +You remember that proof we went +through that all of the + +left eigenvectors and all the +right eigenvectors are all + +orthonormal to each other, +or you can make them all + +orthonormal to each other? + +That says that if the right +eigenvectors are linearly + +independent, you can represent +them as the columns of an + +invertible matrix U. +Then P times U is + +equal to U times lambda. + +What does this equations say? + +You split it up into a +bunch of equations. + +P times U and we look at it as +nu 1, nu 2, nu sub [? n ?]. + +I guess better put the +superscripts on it. + +If I take the matrix U and just +view it as M different + +columns, then what this +is saying is that + +this is equal to-- + +nu 1, nu 2, nu M, times lambda +1, lambda 2, up to lambda M. + +Now you multiply this out, +and what do you get? + +You get nu 1 times lambda 1. + +You get a nu 2 times lambda 2 +for the second column, nu M + +times lambda M for the last +column, and here you get P + +times nu 1 is equal to a nu 1 +times lambda 1, and so forth. + +So all this vector equation says +is the same thing that + +these n M individual eigenvector +equations say. + +It's just a more compact way +of saying the same thing. + +And if these eigenvectors span +this space, then this set of + +eigenvectors are linearly +independent of each other. + +And when you look at the set of +them, this matrix here has + +to have an inverse. + +So you can also express this +as P equals this vector-- + +this matrix of right +eigenvectors times the + +diagonal matrix lambda, times +the inverse of this matrix. + +Matrix U to the minus 1 turns +out to have rows equal to the + +left eigenvectors. + +That's because these +eigenvectors-- + +that's because the right +eigenvectors and the left + +eigenvectors are orthogonal +to each other. + +When we then split up this +matrix into a sum of M + +different matrices, each matrix +having only one-- + +and so forth. + +Then what you get-- + +here's this-- + +this nice equation here, which +says that if all the + +eigenvalues are distinct, then +you can always represent a + +stochastic matrix as the sum of +lambda i times nu to the i + +times pi to the i. + +More importantly, if you take +this equation here and look at + +P to the n, P to the n is U +times lambda times U to the + +minus 1, times U times lambda +times U to the minus 1, blah, + +blah, blah forever. + +Each U to the minus 1 cancels +out with the following U. And + +you wind up with P to the n +equals U times lambda to the + +n, U to the minus 1. + +Which says that P to the +n is just a sum here. + +It's the sum of the eigenvalues +to the n-th power + +times these pairs of +eigenvectors here. + +So this is a general +decomposition for P to the n. + +What we're interested in is what +happens as n gets large. + +If we have a unit chain, we +already know what happens as n + +gets large. + +We know that as n gets large, +we wind up with just 1 times + +this eigenvector e times +this eigenvector pi. + +Which says that all of the other +eigenvalues have to go + +to 0, which says that the +magnitude of these other + +eigenvalues are less than 1. + +So they're all going away. + +So the facts here are that all +eigenvalues lambda have to + +satisfy the magnitude +of lambda is less + +than or equal to 1. + +That's what I just argued. + +For each recurrent class C, +there's one lambda equals 1, + +with a left side and vector +equals the steady state on + +that recurrent class +and 0 elsewhere. + +The right eigenvector nu +satisfies the limit as n goes + +to infinity. + +So the probability that x sub n +is in this recurring class, + +given that x sub 0 is equal +to 0, is equal to the i-th + +component of that right +eigenvector. + +In other words, if you have a +Markov chain which has several + +recurrent classes, and you +want to find out what the + +probability is, starting in the +transient state, of going + +to one of those classes, this is +what tells you that answer. + +This says that the probability +that you go to a particular + +recurrent class C, given that +you start off in a particular + +transient state i, is whatever +that right eigenvector + +turns out to be. + +And you can solve that right +eigenvector problem just as an + +M by M set of linear +equations. + +So you can find the +probabilities of going through + +each transient state just by +solving that set of linear + +equations and finding those +eigenvector equations. + +For each recurrent periodic +class of period d, there are d + +eigenvalues equally spaced +on the unit circle. + +There are no other eigenvalues +with lambda equals 1-- with a + +magnitude of lambda equals 1. + +In other words, for each +recurrent class, you get one + +eigenvalue that's equal to 1. + +If that recurrent class is +periodic, you get a bunch of + +other eigenvalues put around +the unit circle. + +And those are all the +eigenvalues there are. + +Oh my God. + +It's-- + +I thought I was talking +quickly. + +But anyway, if the eigenvectors +don't span the + +space, then P to the n is equal +to U times this Jordan + +reform, U to the minus 1, where +J is a Jordan form. + +What you saw in the homework +when you looked at the-- + +when you looked at the +Markov chain-- + +OK. + +This is one recurrent class +with this one node in it. + +These two nodes are +both transient. + +If you look at how long it takes +to get from here over to + +there, those transition +probabilities do not + +correspond to this +equation here. + +Instead, P sub 1 2-- + +P sub 2 3, the way I've +drawn it here. + +P sub 1 3 is n times this +eigenvalue, which + +is 1/2 in this case. + +And it doesn't correspond to +this, which is why you need a + +Jordan form. + +I said that Jordan forms +are excessively ugly. + +Jordan forms are really very +classy and nice ways of + +dealing with a problem +which is very ugly. + +So don't blame Jordan. + +Jordan simplified +things for us. + +So that's roughly as far as we +went with Markov chains. + +Renewal processes, we don't have +to review them because + +you're already immediately +familiar with them. + +I will do one thing next time +with renewal classes and + +Markov chains, which is to +explain to you why the + +expected amount of time to get +from one state back to itself + +is equal to 1 over pi-- + +1 over pi sub i. + +You did that in the homework. + +And it was an awful +way to do it. + +And there's a nice +way to do it. + +I'll talk about that next time. \ No newline at end of file diff --git a/pkNwvhEm1GQ.txt b/pkNwvhEm1GQ.txt new file mode 100644 index 0000000000000000000000000000000000000000..3f0628ae04425872f9322811a9c7e462d11cc70b --- /dev/null +++ b/pkNwvhEm1GQ.txt @@ -0,0 +1,2230 @@ +The following content is +provided under a Creative + +Commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high quality educational +resources for free. + +To make a donation or view +additional materials from + +hundreds of MIT courses, visit +MIT OpenCourseWare at + +ocw.mit.edu. + +PROFESSOR: Today is our final +clicker competition. + +The first question is up. + +And I would just like to go over +the current standing for + +the clicker competition as we're +getting started here. + +So, recitation 6 has two wins, +and there are other + +recitations and have one win, so +recitation 2, 3, 5, 7, and + +10 have one win. + +If any of those recitation wins +today, we're going to go + +to a tie breaker to decide the +overall recitation champion. + +There are also recitations 1, 4, +9, and 11, who are looking + +for their first win. + +This is their last +chance today. + +So, if they win today, they can +not be overall champions, + +but they will have snacks, +and they will assure that + +recitations 2, 3, 5, 7, and +10 do not win the overall + +competition. + +So, you have a chance to +foil those recitations. + +And if we need to go to a tie +breaker, it will not be from + +current material, it's going +to be past material or past + +things that were mentioned. + +So, just keep that in mind. + +All right, and for the overall +winner, I just would like to + +show you what you will win, so +members of the recitation will + +each get their own chemistry +t-shirt, and at some schools, + +of course, you would look at +this and say oh, they're on + +the varsity team, but at MIT, +it means that you are + +associated with course 5. + +So, Department of Chemistry at +Massachusetts Institute of + +Technology on the back, and we +have different colors and + +different sizes. + +All right, so time to get +started with the clicker + +competition. + +Go ahead and click in your +first responses. + +OK, let's just take +10 more seconds. + +All right. + +Big improvement from the first +time we asked this question + +last class where it's about +33%, now we're up to 89. + +And no, it is not temperature +dependent. + +And we're going to be +talking more about + +activation energy today. + +All right, so today we're going +to finish up kinetics, + +and we're going to start with +the material that we didn't + +quite get to at the +end of last class. + +And I love this part, because +I love it when we can think + +about what we learned before in +a slightly different way. + +So, when I first started +lecturing, I was talking about + +LeChatelier principle and, of +course, encouraged students to + +sort of -- you know it's not too +intuitive to MIT students, + +but LeChatelier's principle says +that if you apply stress + +to a system, it tends to respond +in such a way to + +minimize that stress. + +So it's all about minimizing +stress, which is something + +that's hard to kind to imagine +this time of year, a little + +easier to imagine activation +energy barriers, a little hard + +to imagine minimizing stress. + +But we're back to talking +about minimizing stress. + +And we talked about adding +reagents and removing + +products, and we talked about +how reactions will shift to + +respond to stresses. + +And one of the things we talked +about is rationalizing + +the shift of reactions at +equilibrium when temperature + +has changed. + +So, if you increase the +temperature of a particular + +reaction, it tends to shift in +the endothermic direction to + +remove that added heat +from the reaction. + +So, that's what we learned +before, but now we're going to + +think about this in a slightly +different way. + +So we're going to think about +this in terms of these + +reaction coordinate diagrams. +So, on one axis we have p e + +plotted -- what does +that stand for? + +Potential energy, right, so we +have potential energy going up + +on both sides. + +And here we have a view of an +endothermic reaction, and over + +here is an exothermic +reaction. + +So, let's just take +a look at this. + +For the endothermic reaction, +we have reactants and + +products, we have a delta e +between those, and we have a + +very large activation +energy barrier + +for the forward direction. + +And, of course, for anything to +react, there always has to + +be some barrier, you need some +amount of critical energy, + +because as the molecules come +close to each other, and if + +they're going to react and form +some kind of product, you + +have to sort of distort bonds +and sort of rearrange things, + +and that takes a certain +amount of energy. + +So if they come together and +they have that energy, they'll + +react and go on to products, +if they don't they'll break + +apart and go back and +be reactants. + +And how much temperature the +system has, is more likely + +that they'll be able to react. + +So it's more likely, if there's +high temperature, they + +could overcome this activation +energy barrier. + +All right, so in an endothermic +reaction, you have + +a big one in the forward +direction, and a much smaller + +activation energy in the +reverse direction. + +For exothermic reaction it's +the reverse -- there's a + +smaller barrier for the forward +direction, and a much + +larger barrier for the +reverse direction. + +So, we can think about +the sign of delta e. + +So delta e, this difference here +which is related to delta + +h for liquids and solids, it's +pretty much the same for gases + +is 1% or 2% different. + +So you have a positive value +here, and you can get a + +positive delta e here if you +have a big number for the + +forward activation energy +barrier minus a small number + +for the reverse, so that's +going to give + +you a positive number. + +For an exothermic reaction, +delta e's going to be + +negative, and you get a negative +number if you take a + +small number here for the +forward activation energy, and + +subtract it from a larger number +here for the reverse + +activation energy. + +And remember, this is one of the +equations that we're not + +going to give you, you need to +have that memorized because + +it's part of understanding +what's going on in these + +diagrams. + +So now let's think about what +increasing the temperature is + +going to do. + +So, it will help the molecules +if the is temperatures + +increase, they'll have enough +energy to overcome barriers. + +Now if the barriers are pretty +small, then it's not very hard + +for the molecules to get over +them, regardless of the + +temperature. + +But when the barrier is big, +then temperature is going to + +make a big difference. + +And you can sort of think about +this in your own life as + +you have a small assignment to +do, you just jump in and do it + +and get it done and it's fine. + +But if it's a very, very large +thing that you have to do, you + +often need to procrastinate +longer before + +you start doing it. + +So, a small barrier's not so +much of a problem, but if it's + +a big barrier, you need to +increase that temperature to + +help the molecules get over +the bigger barriers. + +So, let's think about what this +means in terms of the + +direction that a reaction +might shift. + +So, if you increase a +temperature over here with an + +endothermic reaction, it makes +it easier to overcome the + +bigger barrier. + +The forward reaction barrier +is the bigger one, so + +increasing the temperature will +help molecules get over + +that barrier. + +They're already doing fine with +the reverse barrier, it's + +the forward barrier that we're +having trouble with. + +So, if you increase the +temperature, that's going to + +shift the equilibrium toward +products, or it will shift the + +reaction in the endothermic +direction. + +That's what we had learned +before with LeChatelier's + +principle, but now there's a new +way of thinking about why + +that is true. + +So, for an exothermic reaction, +if you increase the + +temperature, that helps with +the bigger barrier. + +Again, here the bigger barrier +is for the reverse reaction. + +So, if you increase the +temperature of an exothermic + +reaction, it's going to shift +it toward reactants. + +More molecules can overcome that +reverse barrier, and so + +you'll form more reactants, +it'll shift toward reactants + +or it'll shift in the +endothermic direction. + +Again, these are the same things +that we already knew + +from LeChatelier, but it's a +different way of thinking + +about why those things +are true. + +So, a large activation energy +barrier means that rate + +constants are very sensitive +to temperature. + +And so, if you have a big +activation energy barrier, + +increasing the temperature makes +a big difference -- if + +it's a big barrier, then there's +going to have a big + +difference if you have +higher temperature. + +If it's a small barrier, then +increasing the temperature + +doesn't make much +of a difference. + +And so you can think about +that in terms of these + +diagrams as well. + +So, now we're done with +temperature and we're going to + +talk about catalysis and +the use of catalysts. + +And so, if you remember there +were factors affecting the + +reaction, and we've talked about +everything on this list + +except for catalysts. + +So today we're going to +talk about catalysts. + +So, a catalyst is a substance +that speeds up a reaction, but + +it doesn't get consumed in the +reaction, it doesn't undergo + +any permanent change itself. + +It's just added to speed +up the reaction. + +So catalysts do not appear in +the overall balanced equation. + +So let's look at what a catalyst +is going to do, and + +we're going to look at in +terms of these potential + +energy diagrams as well. + +So here we here we have a +reaction, we're going from + +reactants down here +to products. + +We have the delta e for the +reaction, we have a forward + +activation energy barrier +and a reverse one. + +So, up here, at the top, that's +our barrier without a + +catalyst. This is the transition +state or the + +activated complex up here, so +you have to overcome the + +barrier, you form some kind of +activated complex, which then, + +if there's enough energy to +overcome that barrier, goes on + +to products. + +So when you add a catalyst +what happens is + +it lowers this barrier. + +So, in the blue line +here is the new + +activation energy barrier. + +This is the barrier with a +catalyst, and so this would + +then be the new transition +state with a catalyst. + +So when it lowers the barrier, +it's going to lower the + +barrier for the forward +reaction, so we have a new + +activation energy for the +forward reaction, and we're + +going to have a new +activation energy + +for the reverse direction. + +So catalysts work by reducing +both the forward and the + +reverse activation +energy barrier. + +And another way that you can +say this is that they + +stabilize the activated +complex or + +the transition state. + +So here you have an activated +complex with a much higher + +potential energy without the +catalysts, and by stabilizing, + +you lower in energy that +transition state. + +So that's another way +of expressing + +what a catalyst does. + +So, catalysts have no effect on +the thermodynamics of the + +reaction, they affect the +kinetics of the reaction, but + +they don't affect the + +thermodynamics of the reaction. + +And so, of course, when you +think of thermodynamics, you + +often think of delta g. + +So, why don't you tell me what +you think, what would happen + +about, so delta g is a state +function, it's independent of + +path, and so therefore, what +can you tell me about the + +equilibrium constant in the +presence of a catalyst? + +OK, let's just take +10 more seconds. + +Yup, very good. + +So, the equilibrium constant +is not changed. + +The thermodynamics, which +includes delta g and the + +equilibrium constant are not +affected, the rates of the + +reaction are affected. + +All right, so opposite of a +catalyst is an inhabitor, and + +we'll talk more about this at +the end of class, so it would + +-- inhibitor is slow or +sometimes stop the rate of the + +reaction, and one way that they +do this is by increasing + +the activation energy. + +So let's consider types +of catalysts now. + +You can have a homogeneous +catalyst, which is in the same + +phase as the reaction that it's + +catalyzing as the reactants. + +An example of this is depletion +of the ozone layer + +by chlorofluorocarbons. + +And so, this was one of the big +environmental challenges + +that the U.S. has faced, whether +it should ban these + +chlorofluorocarbons, and there +was a lot of debate on what + +the data really was about what +how much they affected the + +ozone layer. + +And I guess that debate is +somewhat still going on, + +although I think most people now +recognize that this is a + +serious problem and that +legislation is really needed + +to help correct it. + +So that's an example. + +In this case they're all gases, +so that's homogeneous + +catalyst, not a happy one. + +You could also have +heterogeneous catalysts, which + +are a different phase. + +And here's another example +that has to do with the + +environment. + +So a catalytic converter is an +example of a heterogeneous + +catalyst. So here you have a +solid metal surface, you can + +have palladium or platinum that +will catalyze reactions + +with gases, and so they +catalyze oxidation of + +hydrocarbons, carbon +monoxide, also + +reduction of nitrogen oxide. + +So this is all to reduce +pollution. + +So that's an example of a +heterogeneous catalyst. And + +let me just show you a little +movie of how that might work. + +So in this movie, in grey here +we have a metal surface, and + +this metal surface can break +the hydrogen bond of h 2. + +And so here, it is already +broken, the h 2 bond, so + +there's a little hydrogen there +and hydrogen there, and + +so that activates the +hydrogen to react. + +And so, then we have ethene +molecule come in, and oh, + +there goes the hydrogen, and oh, +there goes the hydrogen, + +oh, there goes the other one +and you can form ethane. + +So it speeds up the reaction +by breaking the h 2 bond so + +it's more ready to react. + +That would be an example of a +heterogeneous catalyst there. + +All right, and, of course, you +may all have guessed that my + +favorite kind of catalysts +are enzymes. + +They are the catalyst of life. + +And so, enzymes are made up of +protein, or mostly protein + +molecules -- you can have an +enzyme that's actually made of + +RNA, but most are protein +molecules. + +And they're typically about +20,000 grams per mole or more, + +and they're capable of carrying + +out specific reactions. + +And so, they're made up of amino +acids, and just to take + +a quick look at that, an amino +acid has an amino group and it + +has a carboxyl group, and it +has what's called an alpha + +carbon that has a side chain on +it, which is abbreviated r, + +and there are 20 different +types of r. + +The simplest is just a hydrogen, +you could also have + +a hydroxide, etc. + +And so, this makes up the +alphabet of proteins, there + +are 20 different ones of these +that get connected via a + +peptide bond. + +So at the end of this amino acid +you'd stick on the amino + +group of another amino acid and +form this peptide bond. + +And then you put together +hundreds and hundreds of these + +to form an enzyme complex. + +And so, the long chain of amino +acids folds up and forms + +a compact structure. + +So, in this particular picture, +there are about 200 + +amino acids in each of these +colored units, so this is a + +tetramer, so there are four +-- there's green, + +red, yellow and blue. + +And so, this is what's called +a ribbon diagram. + +So, these ribbons, this is an +alpha helix -- the beta + +strands are long. + +It traces out the position +of the alpha carbons. + +And overall, this structure is +about 90 angstroms by 70 + +angstroms by 50 angstroms. Of +course, 1 angstroms is 1 times + +10 the minus 10 meters. + +So these are fairly small. + +These protein molecules are, +of course, in your body. + +And this particular one is +an enzyme that makes an + +antibiotic, and that antibiotic +is fosfomycin, + +shown here. + +And so, fosfomycin is used +in antibiotic combination + +therapies to treat staph +infections and other kinds of + +very difficult infections +to treat. + +And so, I always talk about +the things that I'm most + +concerned about. + +There are a lot of things that +are big threats that I don't + +worry too much about. + +Antibiotic resistance +is something I + +actually worry a lot about. + +I guess I go to too many +meetings were they talk about + +problems. But the rate at +which different kinds of + +bacteria are becoming resistant +to antibiotics seems + +to be increasing. + +So it used to take a lot longer +before a resistance + +would appear than it does now. + +And there really haven't been, +I think since about 1980s or + +so, really new antibiotics. + +So, we're still using the same +antibiotics that we have been, + +which causes more things to +become immune or resistant to + +those antibiotics, and I think +this is really dangerous. + +And there's not enough money in +it for the pharmaceutical + +industry to really +go after this. + +And it's not just a problem +for biological warfare, + +although that is a possibility, +but also in + +hospitals, you go in for some +kind of surgery, you have to + +worry about the fact that even +if the surgery goes great, you + +might get an infection that +could really compromise your + +health in the hospital. + +And so, whether you have a heart +problem, if you have + +cancer, you become immune +compromised, there's a lot, a + +lot of cases where people end +up not dying of cancer + +directly, they end up dying of +the bacterial infection that + +can't be treated. + +So this is really +a huge problem. + +So I always like to let you know +all the possible problems + +that you can solve +in your future. + +This is one that I think is +particularly important, and I + +hope some of you will focus on +this, because we really need + +different kinds of antibiotics, +or we need to + +change the way we do medicine +in this country so that + +resistance doesn't become +as much of a + +problem as it has been. + +All right, so that enzyme made +an antibiotic, so we like it, + +and let's talk about +how that works. + +How that particular series of +amino acids folds up to do + +that reaction. + +So now we have some new +nomenclature, and sometimes + +when people get into the +biochemistry world they get + +scared because there are all +these words that they don't + +know what they mean. + +So most of them are not -- they +are things that you can + +relate back to something +you already know. + +So, we've been talking about +reactants, and when you have a + +reactant with an enzyme, it's +usually called a substrate. + +So this is just another name +for a reactant molecule. + +And then substrates tend to +bind in what we call the + +active site of the enzyme, +which is the part of the + +enzyme that's going to +do the chemistry. + +So those are two terms that +you'll hear about in + +biochemistry. + +All right, so we have an enzyme, +we'll call it e, it + +binds a substrate, we'll call +that s, and then it forms an + +enzyme substrate complex, +which we'll call an e s + +complex, for enzyme substrate. + +And then that enzyme substrate +complex will go to enzyme and + +product, which we'll call p. + +And if you look in the +state-of-the-art biochemistry + +books, these are the +abbreviations you'll see in + +there as well. + +So, this pains me greatly to +show this cartoon, because I + +spend my career determining +3-dimensional structures of + +proteins, and so to describe +it as a little squiggly is + +painful for me. + +But nonetheless, there you go. + +Also, the substrate is almost +about as big as the enzyme. + +That is also usually not true. + +But nonetheless, here's +a little cartoon. + +Here's our substrate binding to +our enzyme, it's forming an + +e s complex. + +And then the enzyme is going +to move the ears of the + +substrate around to +form product, and + +now product is released. + +So, this is actually pretty +simple in terms + +of writing a mechanism. + +And so, what we can do is write +a mechanism the way that + +we have been writing +a mechanism + +so far in this class. + +And so we're going to go through +this, we're going to + +derive expression mostly to show +you that all the things + +you've been learning are related +to chemistry, they're + +also related to biochemistry. + +So, you already know a lot +of biochemistry from just + +studying freshman chemistry +in 511-1. + +All right, so we have 2 steps +in our mechanism. + +We have enzyme binding +substrate to form an + +intermediate enzyme substrate +complex, which then goes on to + +form enzyme plus product +in step 2. + +So the first step is reversible, +the second step is + +not as drawn. + +All right, so now we can come up +with the rates for each of + +the individual steps in this +overall mechanism, and since + +they are elementary reactions +or steps in an overall + +mechanism, we can write the rate +laws directly from what + +we observe. + +So for the forward direction, +we're going to + +have what rate constant? + +K 1 times the concentration +of what? + +And? + +Yeah. + +So there we go. + +We have k 1 times the +concentration of e and the + +concentration of s. + +See, you already knew how +to do biochemistry. + +All right, so now at the rate of +the reverse direction is -- + +what's our rate constant? + +K minus 1 times e s. + +And then for step 2, we have +what rate constant? + +K 2 times e s. + +All right, so now we can +talk about the rate + +formation of product. + +And so you'll see this expressed +as d concentration + +of p d t, so the change in +product that's being formed + +and that's going to be equal +to the second step + +here, k 2 times e s. + +But, as has been the case +before, e s is an + +intermediate, and we need to +solve our rate laws, our rate + +expressions, in terms +of reactants or + +products and rate constants. + +So we need to solve for +the intermediate. + +All right, so let's think +about solving for the + +intermediate. + +And why don't you tell +me how to do that. + +OK, let's just take +10 more seconds. + +Very good. + +All right, so let's just +take a look at + +why that is the case. + +So, when we solve for this, it's +going to be equal to the + +formation of the intermediate, +which happens in the first + +step with this rate that you +told me, k 1 times the + +concentration of e s. + +And then we have the +decomposition in the reverse + +of step one, so that's +minus k minus 1 e s. + +And then we also have the +consumption of the + +intermediate, which is -- so we +have minus this step, which + +is k 2 times e s. + +So again, formation minus +decomposition minus + +consumption. + +And now, we can use the steady +state approximation. + +So the steady state +approximation applies in + +biochemistry just as well as +in all of your chemistry + +problems that you've done +in this course. + +And so, the steady state +approximation allows us to set + +that whole term equal to zero. + +So it says that the net rate of +intermediate formation and + +decomposition and consumption is +0, or you can express it as + +the rate of formation of the +intermediate equals the rates + +of decomposition and consumption +-- those are + +equivalent. + +So we can set all of +this equal to zero. + +So again, the same as what +we've done before. + +All right, so now we're going +to have a slight change of + +what we've done before, and +this has to do with the + +practical consideration. + +So you can solve for these +in terms of reactants and + +products and rate constants, +but it's actually easier to + +solve for e s in terms of your +total enzyme rather than your + +free enzyme. + +So what we've had before is our +free enzyme, but we often + +don't know how much enzyme is +free, and by that we mean not + +bound to the substrate. + +And so, we know how much total +enzyme we put in, but we might + +not know how much of +that is unbound. + +So it's actually easier for the +experimentalist to solve + +for things in terms +of total enzyme. + +And so what we're going to do +then is we're going to replace + +our free enzyme term with the +following, total enzyme minus + +bound, and total enzyme +minus the bound + +enzyme is the free enzyme. + +So we're going to do this change +that makes it easier + +for the experimentalist. + +So here's the term we had +before, but now we want to + +replace this term of e with +e to 0 minus e s. + +So we're going to put that, +here's the term e up here, so + +we're going to replace that +with e 0 minus e s. + +And then we're going to multiply +that out, so we get k + +1, e 0, s minus k 1, e s, and +then the concentration of + +substrate here, and the rest +of it is the same. + +So we got rid of our term e. + +So now we can solve for e s. + +So this is what we just had, +and so we're going to + +rearrange so the e s terms are +on one side, so we have an e s + +term here, here, and here. + +So all that is going to be on +one side, and then this other + +term will be on the other +side of the equation. + +So now we have moved all the e +s terms over here, so we've + +got rid of the negative numbers, +we've added them all + +to the other side, and then on +this side we just have this k + +1 term left. + +Now we're going to pull +out the e s terms. So, + +we'll solve for e s. + +We'll pull that out, that leaves +us with k 1 times the + +concentration of s, k minus +1, and then k 2. + +And now we're going to take this +and divide by that term + +in parentheses, and so now we've +solved for e s in terms + +of total enzyme substrate +and our rate constants. + +All right, now we're going +to do another thing + +that's a bit different. + +We're going to introduce a term +in biochemistry, which is + +k m, also known as the +Michaelis-Menten constant, and + +so k m is equal to the +rate constant for the + +forward/reverse direction, k +minus 1 plus k 2 over k 1. + +So we're going to now try to +use this in our expression. + +So we're going to put this term +in there, and so to have + +this term of k m in there, +we need to have this + +divided by k 1. + +So we can do that, it's OK, as +long as we divide everything + +by k 1, so we're going to divide +the top by k 1, and + +this by k 1, and that by k 1. + +So now, we divide all by k 1, +and so we have this top with k + +1, this term with k 1, and +this with k 1, and + +that's our k m value. + +But now we can simplify this, +we've got a lot of k 1's here, + +and so if we simplify this, +we can cross out + +those k 1's over there. + +And we can also get rid of +these k 1's over here. + +And that's going to leave +us with a much simpler + +expression. + +So that's going to leave us with +the total enzyme times + +substrate over substrate +plus k m. + +And that looks a whole lot +better than that other term + +that we had before. + +OK, so we can now take this and +substitute it back into + +the expression we had earlier. + +So here we had the rate of +product formation, k 2 times + +this intermediate, we solved +for the intermediate using + +total enzyme and using +this k m term. + +And now we just put all +of this times k 2. + +And if you put all of that +times k 2, you have this + +expression, which is the +Michaelis-Menten equation. + +So the only difference of what +you did before was that you + +solved in terms of total enzyme, +and also, we have this + +new k m term. + +And so now we have an equation +that's used in a lot of + +biochemistry research to think +about enzyme kinetics. + +So let's think about enzyme +kinetics for a minute. + +This is what a plot often looks +like -- we are looking + +at the product formed by +an enzyme versus the + +concentration of substrate. + +And it often goes up. + +It's pretty steep, and then +it starts to level off. + +So let's think about what's +happening here. + +So if you have low substrate, +so that's way down here, not + +much substrate is available, +adding more substrate will + +increase this rate +significantly, you'll form a + +lot more product, it increases +the rate of product formation. + +Because a lot of the +enzyme is free and + +can react with substrate. + +So it goes up, but then the +rate starts to level off. + +So when you got to higher +substrate concentrations, + +adding more substrate does not +affect the rate much, the rate + +is leveling off. + +And we say that the enzyme +is saturated. + +All the enzyme that you have in +there already has substrate + +going on, it's already +doing the chemistry. + +So if you're throwing more at +it, the enzyme can't bind that + +substrate, it's busy with a +different substrate molecule. + +So all the active sites in the +enzyme are full, and so not + +much happens. + +So this kind of graph +is what you often + +see in enzyme kinetics. + +Now let's think about +that in terms of our + +Michaelis-Menten equation. + +So let's think about conditions +when there's a lot + +of substrate, when substrate +is much greater than k m. + +So here we have substrate and +k m on the bottom of our + +equation, and what's going to +happen if this term is much, + +much bigger than +this k m term? + +What happens to the k m term? + +It goes away. + +It's really small compared +to this, it's kind of + +insignificant. + +So, if that happens, then you +can cancel substrate as well. + +And so, that means that under +conditions where substrate is + +much greater than k m, the rate +is a much simpler term, + +it's just equal to k 2 times +your total enzyme. + +And so this has a name, this is +called Vmax or the maximum + +velocity of the reaction. + +So, under these conditions, +when the substrate is much + +greater than that k m value, +this expression simplifies and + +you get just k 2, your rate +constant, times your total + +enzyme, and that'll give +you the maximum + +velocity of the reaction. + +And so, that's just written +again here. + +Vmax equals k 2 times total +enzyme, and that equation will + +be given to you on an +equation sheet. + +So what's happening? + +What's happening is that +you're up here. + +So when substrate concentration +is much greater + +than k m, then you're in these +conditions, and you're at some + +maximum velocity. + +So the velocity will only go, +the rate of the reaction will + +only go so fast, it will +saturate, it'll level off up + +here, and so you can calculate +that maximum + +rate of that reaction. + +Now let's consider what happens +when your substrate + +concentration equals your k m. + +So down here, if k m is equal to +substrate, then we're going + +to have two substrates +down here. + +And so, we can write this, if +they're equal, we can write + +this as substrate plus +substrate, and then we can do + +some canceling. + +So this will be equal to 2 +substrates and then we can + +cancel that out, and so we get +the rate of product formation + +under conditions where substrate +equals k m of 1/2 k + +2 times the total enzyme +concentration. + +And this is referred to +the half maximal rate. + +Remember, the maximal rate was +k 2 times this e knot, and so + +half of that is half the +maximal rate here. + +So, the definition of k m is the +concentration of substrate + +for which the rate +is half maximal. + +So if your rate is half of the +maximum rate, that substrate + +concentration that gives you +half the maximum rate, is the + +value for k m. + +Substrate concentration equals +k m at the half maximal rate. + +So let's just look at +what that meant. + +So if this is Vmax up here, half +of Vmax is here, half of + +that value, and the substrate +concentration at half Vmax is + +equal to k m. + +So you can write those +in on your diagram. + +Vmax is this velocity up here, +half of that, when you're at + +half of the maximal rate, +k m equals the substrate + +concentration. + +And there will be problems that +you will work in your + +book very shortly, and often, +the problems just have to do, + +they'll give you the information +in words and the + +calculations can often +be pretty simple. + +Sometimes it'll say, figure +out what the k m for this + +reaction is. + +At this substrate concentration, +the rate is + +half maximal. + +Well, at that substrate +concentration, that's the k m. + +So, a lot of the problems are +sort of word problems, they + +give you the information and +you need to know what the + +definitions are. + +But let's try an example. + +So here in this example, we've +talked about buffering in the + +blood, so the conversion of +your ingredients that make + +your buffering agent in the +blood, that can be catalyzed + +by an enzyme called +carbonicanhydrase, and the + +following Michaelis-Menten +constants are known, a k m is + +known, and a k 2 is known, and +if you're doing experiment and + +you have a total concentration +of your enzyme of 5 times 10 + +to the minus 6 molar, then you +should be able to figure out + +what the maximum rate of +the reaction would be. + +So, why don't you go ahead +and tell me what the + +maximum rate would be. + +OK, let's just take +10 more seconds. + +Very good. + +Everyone's doing very +good today. + +All right, so all you have to +do, you have remember Vmax + +equals your total enzyme +concentration times your k 2. + +And pretty much no one, hardly +anyone was fooled + +by k m value there. + +All right, very good. + +So there are extra problems on +enzyme kinetics posted on the + +extra problems posted +on the Web. + +So there's a few there, so you +can see the type of problems, + +again, they're like that, +they're pretty simple. + +If you remember the definition +of k m, and you'll be given + +the equation for Vmax, you +should be able to handle the + +enzyme/kinetics problems +pretty well. + +Often, also I'll ask questions +like explain why at high + +substrate concentrations, the +rate does not increase very + +much, or why the graph levels +off, or I might ask you to + +draw the plot and tell me +about low substrate + +concentrations, what's true +there, and high substrate + +concentrations, what's true. + +So those are the types of +questions you're going to get + +on enzyme kinetics, they're +actually pretty simple. + +All right, so let's just talk +briefly about enzyme + +inhibition. + +So the opposite of catalysis +-- instead of binding a + +substrate, you'll bind +an inhibitor. + +So often, these are actually +pretty simple. + +An inhibitor sometimes will look +a lot like a substrate or + +like a transition complex, and +it'll blind to the enzyme. + +And when you have that inhibitor +stuck in the active + +site, substrate physically can't +bind, so it occupies the + +place that substrate goes, +substrate will come in but it + +can't bind anywhere. + +So this is actually the +mechanism by which a number of + +pharmaceuticals work. + +So, one thing that people who +were designing enzyme + +inhibitors think about is the +fact that enzymes do tend to + +stabilize a transition state +in the reaction. + +So if you make an inhibitor that +resembles a transition + +state, it should bind to the +enzyme more tightly than + +either the reactants, the +substrates, or the products. + +So, a lot of the pharmaceutical +industry likes + +to try to figure out what the +transition state might look + +like, and then try to make a +molecule that looks like that + +transition state that hopefully +will blind to the + +enzyme active site and prevent +the enzyme from doing what + +it's supposed to do. + +So, just to kind of look back +at this figure for a minute + +that you had earlier in your +notes, so you have the + +transition state is often +stabilized by a catalyst, and + +so an enzyme will also stabilize +a transition state. + +So if you make your drug look +like a transition state, it + +will hopefully bind +very tightly. + +And so this is one of the sort +of principles that's behind a + +lot of the pharmaceuticals that +have made to treat HIV + +infections. + +So I mentioned last week we +had world AIDS day, that + +understanding kinetics +was actually very + +important in HIV research. + +And so, many of the +pharmaceuticals that are given + +to HIV patients are what are +called protease inhibitors. + +So they inhibit enzymes that are +called proteases, and if + +you have ase at the end of the +name that means it's an + +enzyme, and so protease means +that it's an enzyme that + +cleaves proteins. + +It's a protein ase. + +And so, how do these +enzymes work. + +Well, they cleave other +proteins, they cleave peptide + +bonds, and so you often have +some kind of either activated + +water or other hydroxide +molecule that will attack here + +the carbonyl of a peptide +bond, and it forms a + +tetrahedral intermediate, which +then collapses and it + +cleaves that peptide bond. + +So the peptide bond is then +broken, so that's what a + +protease does, and a +protease inhibitor + +prevents that cleavage. + +So often, protease inhibitors +look like tetrahedral + +intermediates, and so they'll +bind to the protease active + +site and prevent the chemistry +from occurring. + +So if it's a tetrahedral +intermediate, what kind of + +angles should some +pharmaceutical company be + +looking for in its compounds? + +109 . + +5, yes. + +So, molecules with this stable +tetrahedral intermediate + +somewhere on the molecule could +bind to the active site + +and prevent a catalysis. + +So, let me just show you one +example of an improved HIV + +drug, and there it is. + +This is the tetrahedral site +that binds at the active site + +of that enzyme, and the enzyme +can't cleave this tetrahedral + +intermediate, and so this just +binds, but the enzyme can't + +work on it, so it just sits +there and prevents substrate + +from binding. + +So that's how a lot of +these compounds work. + +And so, this is just a little +picture of the enzyme active + +site and there's an inhibitor +bound to the enzyme active + +site, and so a number of +companies are working on + +trying to come up with better +and better inhibitors that + +will sit in the HIV protease +active site. + +So, knowledgeable of a reaction +mechanism can lead to + +new therapeutic treatments. + +So, one question with this, with +protease, there are a lot + +of proteases, not just the ones +involved with HIV, and so + +one real problem is specificity +and toxicity, so + +you want to have a drug that +inhibits one enzyme and not + +all the enzymes in +that category. + +So that's a big problem in the +pharmaceutical industry. + +So, apparently, clicker results, +we actually need to + +break a tie. + +But we can't do it now. + +OK, so Justin's section, woah! + +So, apparently we're having, we +have the questions ready, + +but apparently they're +not ready to be used + +right at the moment. + +So, we're going to use low tech +here and indicate the + +results for today. + +And then on Wednesday, last +day of class -- oh, my + +goodness, so close. + +Recitation 6, you were second. + +All right, so on Wednesday then, +we're going to have the + +tie breaker, and review +and evaluations. \ No newline at end of file diff --git a/qTGGSVjEBUw.txt b/qTGGSVjEBUw.txt new file mode 100644 index 0000000000000000000000000000000000000000..03cb80ece983366bd17553ad4bf363464fb26172 --- /dev/null +++ b/qTGGSVjEBUw.txt @@ -0,0 +1,14419 @@ +align:start position:0% + +good afternoon + + align:start position:0% +good afternoon + + + align:start position:0% +good afternoon +so with been studying properties of + + align:start position:0% +so with been studying properties of + + + align:start position:0% +so with been studying properties of +stable equilibrium + + align:start position:0% +stable equilibrium + + + align:start position:0% +stable equilibrium +States relations that can be extracted + + align:start position:0% +States relations that can be extracted + + + align:start position:0% +States relations that can be extracted +from the fundamental + + align:start position:0% +from the fundamental + + + align:start position:0% +from the fundamental +relation of any + + align:start position:0% +relation of any + + + align:start position:0% +relation of any +system and therefore if the system is + + align:start position:0% +system and therefore if the system is + + + align:start position:0% +system and therefore if the system is +for example a substance of a pure + + align:start position:0% +for example a substance of a pure + + + align:start position:0% +for example a substance of a pure +substance or mixtures of + + align:start position:0% +substance or mixtures of + + + align:start position:0% +substance or mixtures of +substances um yes it is a lot of um + + align:start position:0% +substances um yes it is a lot of um + + + align:start position:0% +substances um yes it is a lot of um +math and mathematical manipulations and + + align:start position:0% +math and mathematical manipulations and + + + align:start position:0% +math and mathematical manipulations and +today we'll have a little more of that + + align:start position:0% +today we'll have a little more of that + + + align:start position:0% +today we'll have a little more of that +uh then we we we stop about the + + align:start position:0% +uh then we we we stop about the + + + align:start position:0% +uh then we we we stop about the +mathematics at least for this part uh + + align:start position:0% +mathematics at least for this part uh + + + align:start position:0% +mathematics at least for this part uh +but I wanted + + align:start position:0% +but I wanted + + + align:start position:0% +but I wanted +to to stress the fact that + + align:start position:0% +to to stress the fact that + + + align:start position:0% +to to stress the fact that +we are extracting a lot of U information + + align:start position:0% +we are extracting a lot of U information + + + align:start position:0% +we are extracting a lot of U information +out of just the idea that there exists a + + align:start position:0% +out of just the idea that there exists a + + + align:start position:0% +out of just the idea that there exists a +fundamental relation for stable + + align:start position:0% +fundamental relation for stable + + + align:start position:0% +fundamental relation for stable +equilibrium States from which we can + + align:start position:0% +equilibrium States from which we can + + + align:start position:0% +equilibrium States from which we can +extract + + align:start position:0% +extract + + + align:start position:0% +extract +properties uh and it's precisely the + + align:start position:0% +properties uh and it's precisely the + + + align:start position:0% +properties uh and it's precisely the +mathematical M manipulations that is not + + align:start position:0% +mathematical M manipulations that is not + + + align:start position:0% +mathematical M manipulations that is not +just by itself but with proper physical + + align:start position:0% +just by itself but with proper physical + + + align:start position:0% +just by itself but with proper physical +interpretation and that's the important + + align:start position:0% +interpretation and that's the important + + + align:start position:0% +interpretation and that's the important +aspect it's not just the mathematics + + align:start position:0% +aspect it's not just the mathematics + + + align:start position:0% +aspect it's not just the mathematics +it's also to interpret the mathematics + + align:start position:0% +it's also to interpret the mathematics + + + align:start position:0% +it's also to interpret the mathematics +and then see what the useful part of it + + align:start position:0% +and then see what the useful part of it + + + align:start position:0% +and then see what the useful part of it +is it's from this that you can extract a + + align:start position:0% +is it's from this that you can extract a + + + align:start position:0% +is it's from this that you can extract a +lot of + + align:start position:0% +lot of + + + align:start position:0% +lot of +information uh for example in + + align:start position:0% +information uh for example in + + + align:start position:0% +information uh for example in +um in + + align:start position:0% +um in + + + align:start position:0% +um in +economics manipulations of this + + align:start position:0% + + + + align:start position:0% + +sort have earned uh the Nobel Prize to + + align:start position:0% +sort have earned uh the Nobel Prize to + + + align:start position:0% +sort have earned uh the Nobel Prize to +Paul Samuelson who was a professor here + + align:start position:0% +Paul Samuelson who was a professor here + + + align:start position:0% +Paul Samuelson who was a professor here +with MIT uh because you realize that + + align:start position:0% +with MIT uh because you realize that + + + align:start position:0% +with MIT uh because you realize that +essentially also in economics don't ask + + align:start position:0% +essentially also in economics don't ask + + + align:start position:0% +essentially also in economics don't ask +me what part of Economics but in any + + align:start position:0% +me what part of Economics but in any + + + align:start position:0% +me what part of Economics but in any +case in economics there are functions + + align:start position:0% +case in economics there are functions + + + align:start position:0% +case in economics there are functions +like that that can be manipulated by the + + align:start position:0% +like that that can be manipulated by the + + + align:start position:0% +like that that can be manipulated by the +tools that we are developing from which + + align:start position:0% +tools that we are developing from which + + + align:start position:0% +tools that we are developing from which +you can extract a lot of information + + align:start position:0% +you can extract a lot of information + + + align:start position:0% +you can extract a lot of information +about uh economics in that + + align:start position:0% +about uh economics in that + + + align:start position:0% +about uh economics in that +case so uh mathematics is a powerful uh + + align:start position:0% +case so uh mathematics is a powerful uh + + + align:start position:0% +case so uh mathematics is a powerful uh +uh + + align:start position:0% +uh + + + align:start position:0% +uh +tool and way of that allows you to think + + align:start position:0% +tool and way of that allows you to think + + + align:start position:0% +tool and way of that allows you to think +straight so all right yes we've done the + + align:start position:0% +straight so all right yes we've done the + + + align:start position:0% +straight so all right yes we've done the +Leandra transform and uh we have applied + + align:start position:0% +Leandra transform and uh we have applied + + + align:start position:0% +Leandra transform and uh we have applied +it to derive uh uh the elal free energy + + align:start position:0% +it to derive uh uh the elal free energy + + + align:start position:0% +it to derive uh uh the elal free energy +the Gibs free energy the + + align:start position:0% +the Gibs free energy the + + + align:start position:0% +the Gibs free energy the +enthalpy and also this Oiler free + + align:start position:0% +enthalpy and also this Oiler free + + + align:start position:0% +enthalpy and also this Oiler free +energy that uh + + align:start position:0% +energy that uh + + + align:start position:0% +energy that uh +will return to to to also today and uh + + align:start position:0% +will return to to to also today and uh + + + align:start position:0% +will return to to to also today and uh +and the next + + align:start position:0% +and the next + + + align:start position:0% +and the next +time also we develop this Max + + align:start position:0% +time also we develop this Max + + + align:start position:0% +time also we develop this Max +coming from the second this the the + + align:start position:0% +coming from the second this the the + + + align:start position:0% +coming from the second this the the +reciprocity of the second order + + align:start position:0% +reciprocity of the second order + + + align:start position:0% +reciprocity of the second order +derivatives of the various + + align:start position:0% +derivatives of the various + + + align:start position:0% +derivatives of the various +functions today I want to introduce uh + + align:start position:0% +functions today I want to introduce uh + + + align:start position:0% +functions today I want to introduce uh +quickly or in the review quickly if + + align:start position:0% +quickly or in the review quickly if + + + align:start position:0% +quickly or in the review quickly if +you've seen it already the this um other + + align:start position:0% +you've seen it already the this um other + + + align:start position:0% +you've seen it already the this um other +tool which is the Jacobian + + align:start position:0% + + + + align:start position:0% + +determinants uh so if you have a system + + align:start position:0% +determinants uh so if you have a system + + + align:start position:0% +determinants uh so if you have a system +of two uh + + align:start position:0% +of two uh + + + align:start position:0% +of two uh +functions and you take the Matrix in + + align:start position:0% +functions and you take the Matrix in + + + align:start position:0% +functions and you take the Matrix in +which you put all the the partial + + align:start position:0% +which you put all the the partial + + + align:start position:0% +which you put all the the partial +derivatives in that fashion the + + align:start position:0% +derivatives in that fashion the + + + align:start position:0% +derivatives in that fashion the +determinant of that Matrix is called the + + align:start position:0% +determinant of that Matrix is called the + + + align:start position:0% +determinant of that Matrix is called the +Jacobian determinant The Matrix is the + + align:start position:0% +Jacobian determinant The Matrix is the + + + align:start position:0% +Jacobian determinant The Matrix is the +Jacobian and the determinant of the of + + align:start position:0% +Jacobian and the determinant of the of + + + align:start position:0% +Jacobian and the determinant of the of +the Jacobian is we call it + + align:start position:0% +the Jacobian is we call it + + + align:start position:0% +the Jacobian is we call it +the uh Jacobian anyway just for short + + align:start position:0% +the uh Jacobian anyway just for short + + + align:start position:0% +the uh Jacobian anyway just for short +and we use this uh symbol which + + align:start position:0% +and we use this uh symbol which + + + align:start position:0% +and we use this uh symbol which +resembles a partial because somehow it's + + align:start position:0% +resembles a partial because somehow it's + + + align:start position:0% +resembles a partial because somehow it's +it's a partial of a vector of of + + align:start position:0% +it's a partial of a vector of of + + + align:start position:0% +it's a partial of a vector of of +functions with respect to a vector of + + align:start position:0% +functions with respect to a vector of + + + align:start position:0% +functions with respect to a vector of +the uh independent + + align:start position:0% +the uh independent + + + align:start position:0% +the uh independent +variables and it has these properties + + align:start position:0% +variables and it has these properties + + + align:start position:0% +variables and it has these properties +which you can infer easily by uh the + + align:start position:0% +which you can infer easily by uh the + + + align:start position:0% +which you can infer easily by uh the +properties of determinants you exchange + + align:start position:0% +properties of determinants you exchange + + + align:start position:0% +properties of determinants you exchange +a row exchange a column you exchange the + + align:start position:0% +a row exchange a column you exchange the + + + align:start position:0% +a row exchange a column you exchange the +sign uh and uh so you can easily prove + + align:start position:0% +sign uh and uh so you can easily prove + + + align:start position:0% +sign uh and uh so you can easily prove +these + + align:start position:0% +these + + + align:start position:0% +these +relations you can also notice that if + + align:start position:0% +relations you can also notice that if + + + align:start position:0% +relations you can also notice that if +one of the functions like for example + + align:start position:0% +one of the functions like for example + + + align:start position:0% +one of the functions like for example +G is the uh is the is the simple + + align:start position:0% +G is the uh is the is the simple + + + align:start position:0% +G is the uh is the is the simple +function gals + + align:start position:0% +function gals + + + align:start position:0% +function gals +y + + align:start position:0% +y + + + align:start position:0% +y +then uh the second row is just the + + align:start position:0% +then uh the second row is just the + + + align:start position:0% +then uh the second row is just the +derivative of y with respect to X since + + align:start position:0% +derivative of y with respect to X since + + + align:start position:0% +derivative of y with respect to X since +Y and X are independent variables that's + + align:start position:0% +Y and X are independent variables that's + + + align:start position:0% +Y and X are independent variables that's +zero and this the derivative of y with + + align:start position:0% +zero and this the derivative of y with + + + align:start position:0% +zero and this the derivative of y with +respect to Y is one okay so that's zero + + align:start position:0% +respect to Y is one okay so that's zero + + + align:start position:0% +respect to Y is one okay so that's zero +and one which leaves for the determinant + + align:start position:0% +and one which leaves for the determinant + + + align:start position:0% +and one which leaves for the determinant +just this term here which is the partial + + align:start position:0% +just this term here which is the partial + + + align:start position:0% +just this term here which is the partial +derivative of of f with respect to + + align:start position:0% +derivative of of f with respect to + + + align:start position:0% +derivative of of f with respect to +X so this is a a useful identity because + + align:start position:0% +X so this is a a useful identity because + + + align:start position:0% +X so this is a a useful identity because +you can pass from partial derivatives + + align:start position:0% +you can pass from partial derivatives + + + align:start position:0% +you can pass from partial derivatives +that maybe you want to + + align:start position:0% +that maybe you want to + + + align:start position:0% +that maybe you want to +evaluate to an equivalent Jacobian and + + align:start position:0% +evaluate to an equivalent Jacobian and + + + align:start position:0% +evaluate to an equivalent Jacobian and +then we will see that we can manipulate + + align:start position:0% +then we will see that we can manipulate + + + align:start position:0% +then we will see that we can manipulate +that uh + + align:start position:0% + + + + align:start position:0% + +further of course if also f is equal to + + align:start position:0% +further of course if also f is equal to + + + align:start position:0% +further of course if also f is equal to +X then this the is + + align:start position:0% +X then this the is + + + align:start position:0% +X then this the is +becomes simply the entity I mean + + align:start position:0% +becomes simply the entity I mean + + + align:start position:0% +becomes simply the entity I mean +one okay the other theorem about zius is + + align:start position:0% +one okay the other theorem about zius is + + + align:start position:0% +one okay the other theorem about zius is +that if you consider a function of a + + align:start position:0% +that if you consider a function of a + + + align:start position:0% +that if you consider a function of a +single variable and you invert the + + align:start position:0% +single variable and you invert the + + + align:start position:0% +single variable and you invert the +function so you have f is a function of + + align:start position:0% +function so you have f is a function of + + + align:start position:0% +function so you have f is a function of +X and you invert it as X as a function + + align:start position:0% +X and you invert it as X as a function + + + align:start position:0% +X and you invert it as X as a function +of F you know that the derivative of + + align:start position:0% +of F you know that the derivative of + + + align:start position:0% +of F you know that the derivative of +this inverted function is equal to the + + align:start position:0% +this inverted function is equal to the + + + align:start position:0% +this inverted function is equal to the +inverse of the derivative of the + + align:start position:0% +inverse of the derivative of the + + + align:start position:0% +inverse of the derivative of the +original + + align:start position:0% +original + + + align:start position:0% +original +function and the equivalent for a system + + align:start position:0% +function and the equivalent for a system + + + align:start position:0% +function and the equivalent for a system +of uh um uh two functions of two + + align:start position:0% +of uh um uh two functions of two + + + align:start position:0% +of uh um uh two functions of two +variables is that + + align:start position:0% +variables is that + + + align:start position:0% +variables is that +the uh + + align:start position:0% +the uh + + + align:start position:0% +the uh +Jacobian of the inverted + + align:start position:0% +Jacobian of the inverted + + + align:start position:0% +Jacobian of the inverted +system when you solve the system this + + align:start position:0% +system when you solve the system this + + + align:start position:0% +system when you solve the system this +system of equations to put in evidence X + + align:start position:0% +system of equations to put in evidence X + + + align:start position:0% +system of equations to put in evidence X +and Y is a function on F of f and g so + + align:start position:0% +and Y is a function on F of f and g so + + + align:start position:0% +and Y is a function on F of f and g so +you change the independent + + align:start position:0% +you change the independent + + + align:start position:0% +you change the independent +variables uh and so you invert well the + + align:start position:0% +variables uh and so you invert well the + + + align:start position:0% +variables uh and so you invert well the +uh Jacobian of the invert system is + + align:start position:0% +uh Jacobian of the invert system is + + + align:start position:0% +uh Jacobian of the invert system is +equal to the inverse of the Jacobian of + + align:start position:0% +equal to the inverse of the Jacobian of + + + align:start position:0% +equal to the inverse of the Jacobian of +the original + + align:start position:0% +the original + + + align:start position:0% +the original +system and that also shows shows that if + + align:start position:0% +system and that also shows shows that if + + + align:start position:0% +system and that also shows shows that if +you prove if you um choose the function + + align:start position:0% +you prove if you um choose the function + + + align:start position:0% +you prove if you um choose the function +g y as + + align:start position:0% +g y as + + + align:start position:0% +g y as +before gals y as before you can uh prove + + align:start position:0% +before gals y as before you can uh prove + + + align:start position:0% +before gals y as before you can uh prove +by this relation the fact that the uh + + align:start position:0% +by this relation the fact that the uh + + + align:start position:0% +by this relation the fact that the uh +inverse I mean the partial derivative + + align:start position:0% +inverse I mean the partial derivative + + + align:start position:0% +inverse I mean the partial derivative +of the inverse with respect to F at fix + + align:start position:0% +of the inverse with respect to F at fix + + + align:start position:0% +of the inverse with respect to F at fix +Y is equal to the inverse of the + + align:start position:0% +Y is equal to the inverse of the + + + align:start position:0% +Y is equal to the inverse of the +original partial + + align:start position:0% +original partial + + + align:start position:0% +original partial +derivative so + + align:start position:0% +derivative so + + + align:start position:0% +derivative so +formally you see this is uh X over y a + + align:start position:0% +formally you see this is uh X over y a + + + align:start position:0% +formally you see this is uh X over y a +constant y let's read it Loosely well + + align:start position:0% +constant y let's read it Loosely well + + + align:start position:0% +constant y let's read it Loosely well +you can just uh put uh it uh consider + + align:start position:0% +you can just uh put uh it uh consider + + + align:start position:0% +you can just uh put uh it uh consider +the DX and the Dy consider it as a + + align:start position:0% +the DX and the Dy consider it as a + + + align:start position:0% +the DX and the Dy consider it as a +fraction and put it under a the + + align:start position:0% +fraction and put it under a the + + + align:start position:0% +fraction and put it under a the +denominator and you get this function + + align:start position:0% +denominator and you get this function + + + align:start position:0% +denominator and you get this function +and uh it is fair in other words it + + align:start position:0% +and uh it is fair in other words it + + + align:start position:0% +and uh it is fair in other words it +proves that you can do that easy uh + + align:start position:0% + + + + align:start position:0% + +manipulation all right and the other + + align:start position:0% +manipulation all right and the other + + + align:start position:0% +manipulation all right and the other +item is that if you have a function f of + + align:start position:0% +item is that if you have a function f of + + + align:start position:0% +item is that if you have a function f of +x so X is your independent variable but + + align:start position:0% +x so X is your independent variable but + + + align:start position:0% +x so X is your independent variable but +but suppose you want to represent your + + align:start position:0% +but suppose you want to represent your + + + align:start position:0% +but suppose you want to represent your +independent variable as a in parametric + + align:start position:0% +independent variable as a in parametric + + + align:start position:0% +independent variable as a in parametric +form so you have so X is a function of + + align:start position:0% +form so you have so X is a function of + + + align:start position:0% +form so you have so X is a function of +another uh variable say a x of a so you + + align:start position:0% +another uh variable say a x of a so you + + + align:start position:0% +another uh variable say a x of a so you +substitute in the function and so you + + align:start position:0% +substitute in the function and so you + + + align:start position:0% +substitute in the function and so you +have a function of a function this is a + + align:start position:0% +have a function of a function this is a + + + align:start position:0% +have a function of a function this is a +function of a now a has become the + + align:start position:0% +function of a now a has become the + + + align:start position:0% +function of a now a has become the +independent + + align:start position:0% +independent + + + align:start position:0% +independent +variable so the chain rule for + + align:start position:0% +variable so the chain rule for + + + align:start position:0% +variable so the chain rule for +derivatives says for for single + + align:start position:0% +derivatives says for for single + + + align:start position:0% +derivatives says for for single +variables that the derivative of f + + align:start position:0% +variables that the derivative of f + + + align:start position:0% +variables that the derivative of f +respect to a is the derivative of s with + + align:start position:0% +respect to a is the derivative of s with + + + align:start position:0% +respect to a is the derivative of s with +respect to x times the derivative of x + + align:start position:0% +respect to x times the derivative of x + + + align:start position:0% +respect to x times the derivative of x +with respect to a okay the + + align:start position:0% +with respect to a okay the + + + align:start position:0% +with respect to a okay the +equivalent for our system of two + + align:start position:0% +equivalent for our system of two + + + align:start position:0% +equivalent for our system of two +variables uh so when you change your + + align:start position:0% +variables uh so when you change your + + + align:start position:0% +variables uh so when you change your +system f and g uh in instead of as a + + align:start position:0% +system f and g uh in instead of as a + + + align:start position:0% +system f and g uh in instead of as a +function of X and Y but is a function of + + align:start position:0% +function of X and Y but is a function of + + + align:start position:0% +function of X and Y but is a function of +a and b so the X and Y are in turn + + align:start position:0% +a and b so the X and Y are in turn + + + align:start position:0% +a and b so the X and Y are in turn +functions of a and + + align:start position:0% +functions of a and + + + align:start position:0% +functions of a and +b um then you have a situation similar + + align:start position:0% +b um then you have a situation similar + + + align:start position:0% +b um then you have a situation similar +to that and the derivative actually the + + align:start position:0% +to that and the derivative actually the + + + align:start position:0% +to that and the derivative actually the +Jacobian of S and G with respect to the + + align:start position:0% +Jacobian of S and G with respect to the + + + align:start position:0% +Jacobian of S and G with respect to the +new + + align:start position:0% +new + + + align:start position:0% +new +variables you can is equal + + align:start position:0% + + + + align:start position:0% + +to uh the Jacobian with respect to the + + align:start position:0% +to uh the Jacobian with respect to the + + + align:start position:0% +to uh the Jacobian with respect to the +old variables times the Jacobian of the + + align:start position:0% +old variables times the Jacobian of the + + + align:start position:0% +old variables times the Jacobian of the +new Vari of the old variables with + + align:start position:0% +new Vari of the old variables with + + + align:start position:0% +new Vari of the old variables with +respect to the old + + align:start position:0% +respect to the old + + + align:start position:0% +respect to the old +one and + + align:start position:0% +one and + + + align:start position:0% +one and +formally you can + + align:start position:0% + + + + align:start position:0% + +uh write this result suppose you delete + + align:start position:0% +uh write this result suppose you delete + + + align:start position:0% +uh write this result suppose you delete +these two so you view + + align:start position:0% +these two so you view + + + align:start position:0% +these two so you view +this result is simply the Jacobian of f + + align:start position:0% +this result is simply the Jacobian of f + + + align:start position:0% +this result is simply the Jacobian of f +with respect to + + align:start position:0% +with respect to + + + align:start position:0% +with respect to +a so you write it this way and then you + + align:start position:0% +a so you write it this way and then you + + + align:start position:0% +a so you write it this way and then you +have empty spaces here where you can put + + align:start position:0% +have empty spaces here where you can put + + + align:start position:0% +have empty spaces here where you can put +anything that cancels out so for example + + align:start position:0% +anything that cancels out so for example + + + align:start position:0% +anything that cancels out so for example +you can put the Jacobian of XY with + + align:start position:0% +you can put the Jacobian of XY with + + + align:start position:0% +you can put the Jacobian of XY with +respect to XY which is equal to one the + + align:start position:0% +respect to XY which is equal to one the + + + align:start position:0% +respect to XY which is equal to one the +identity we just proved it + + align:start position:0% +identity we just proved it + + + align:start position:0% +identity we just proved it +before and + + align:start position:0% +before and + + + align:start position:0% +before and +th uh the formal manipulation becomes uh + + align:start position:0% +th uh the formal manipulation becomes uh + + + align:start position:0% +th uh the formal manipulation becomes uh +uh easy now because uh then you + + align:start position:0% +uh easy now because uh then you + + + align:start position:0% +uh easy now because uh then you +interpret this one as the Jacobian of f + + align:start position:0% +interpret this one as the Jacobian of f + + + align:start position:0% +interpret this one as the Jacobian of f +with respect to XY and this is as the + + align:start position:0% +with respect to XY and this is as the + + + align:start position:0% +with respect to XY and this is as the +Jacobian of XY with respect to + + align:start position:0% +Jacobian of XY with respect to + + + align:start position:0% +Jacobian of XY with respect to +a + + align:start position:0% + + + + align:start position:0% + +okay let's give an example that brings + + align:start position:0% +okay let's give an example that brings + + + align:start position:0% +okay let's give an example that brings +us to a a a useful uh relation useful + + align:start position:0% +us to a a a useful uh relation useful + + + align:start position:0% +us to a a a useful uh relation useful +identity for two properties that are uh + + align:start position:0% +identity for two properties that are uh + + + align:start position:0% +identity for two properties that are uh +among the list that we have seen are + + align:start position:0% +among the list that we have seen are + + + align:start position:0% +among the list that we have seen are +measurable so + + align:start position:0% +measurable so + + + align:start position:0% +measurable so +take the + + align:start position:0% +take the + + + align:start position:0% +take the +S determinant the determinant of the S + + align:start position:0% +S determinant the determinant of the S + + + align:start position:0% +S determinant the determinant of the S +relation of the S Matrix of the + + align:start position:0% +relation of the S Matrix of the + + + align:start position:0% +relation of the S Matrix of the +fundamental relation with respect to + + align:start position:0% +fundamental relation with respect to + + + align:start position:0% +fundamental relation with respect to +entropy and volume so it's the Matrix of + + align:start position:0% +entropy and volume so it's the Matrix of + + + align:start position:0% +entropy and volume so it's the Matrix of +the second order derivatives of energy + + align:start position:0% +the second order derivatives of energy + + + align:start position:0% +the second order derivatives of energy +with respect to entropy and + + align:start position:0% +with respect to entropy and + + + align:start position:0% +with respect to entropy and +volume now since + + align:start position:0% +volume now since + + + align:start position:0% +volume now since +these second derivatives are derivatives + + align:start position:0% +these second derivatives are derivatives + + + align:start position:0% +these second derivatives are derivatives +of for example we remember that the + + align:start position:0% +of for example we remember that the + + + align:start position:0% +of for example we remember that the +derivative the first derivative of e + + align:start position:0% +derivative the first derivative of e + + + align:start position:0% +derivative the first derivative of e +with respect to S is the temperature you + + align:start position:0% +with respect to S is the temperature you + + + align:start position:0% +with respect to S is the temperature you +can also write them in this way + + align:start position:0% +can also write them in this way + + + align:start position:0% +can also write them in this way +in terms of + + align:start position:0% +in terms of + + + align:start position:0% +in terms of +the conjugate + + align:start position:0% +the conjugate + + + align:start position:0% +the conjugate +variables temperature for entropy minus + + align:start position:0% +variables temperature for entropy minus + + + align:start position:0% +variables temperature for entropy minus +the pressure for + + align:start position:0% +the pressure for + + + align:start position:0% +the pressure for +volume okay so this is just uh applying + + align:start position:0% +volume okay so this is just uh applying + + + align:start position:0% +volume okay so this is just uh applying +those + + align:start position:0% +those + + + align:start position:0% +those +definitions and then here you recognize + + align:start position:0% +definitions and then here you recognize + + + align:start position:0% +definitions and then here you recognize +that apart from the minus sign here that + + align:start position:0% +that apart from the minus sign here that + + + align:start position:0% +that apart from the minus sign here that +can be uh taken to outside of the + + align:start position:0% +can be uh taken to outside of the + + + align:start position:0% +can be uh taken to outside of the +determinant this is just the Coban of + + align:start position:0% +determinant this is just the Coban of + + + align:start position:0% +determinant this is just the Coban of +temperature and pressure versus uh with + + align:start position:0% +temperature and pressure versus uh with + + + align:start position:0% +temperature and pressure versus uh with +respect to S + + align:start position:0% +respect to S + + + align:start position:0% +respect to S +snv so now let's do this trick of + + align:start position:0% +snv so now let's do this trick of + + + align:start position:0% +snv so now let's do this trick of +Shifting the denominator leing the empty + + align:start position:0% +Shifting the denominator leing the empty + + + align:start position:0% +Shifting the denominator leing the empty +spaces and let's put here whatever we + + align:start position:0% + + + + align:start position:0% + +want so I'll do it in two ways I put + + align:start position:0% +want so I'll do it in two ways I put + + + align:start position:0% +want so I'll do it in two ways I put +SNP here and + + align:start position:0% + + + + align:start position:0% + +there okay and then I have I notice that + + align:start position:0% +there okay and then I have I notice that + + + align:start position:0% +there okay and then I have I notice that +I have chosen my uh I make it make my my + + align:start position:0% +I have chosen my uh I make it make my my + + + align:start position:0% +I have chosen my uh I make it make my my +choice so + + align:start position:0% +choice so + + + align:start position:0% +choice so +that uh in each of these determinant I + + align:start position:0% +that uh in each of these determinant I + + + align:start position:0% +that uh in each of these determinant I +mean + + align:start position:0% +mean + + + align:start position:0% +mean +Jacobian there is a repeated U uh + + align:start position:0% +Jacobian there is a repeated U uh + + + align:start position:0% +Jacobian there is a repeated U uh +pressure above and + + align:start position:0% +pressure above and + + + align:start position:0% +pressure above and +below so that is the derivative of of t + + align:start position:0% +below so that is the derivative of of t + + + align:start position:0% +below so that is the derivative of of t +with respect to S at constant + + align:start position:0% +with respect to S at constant + + + align:start position:0% +with respect to S at constant +p and this other side has s which is + + align:start position:0% +p and this other side has s which is + + + align:start position:0% +p and this other side has s which is +repeated + + align:start position:0% +repeated + + + align:start position:0% +repeated +so that is the derivative of p with + + align:start position:0% +so that is the derivative of p with + + + align:start position:0% +so that is the derivative of p with +respect to V at constant + + align:start position:0% + + + + align:start position:0% + +s then if you look + + align:start position:0% +s then if you look + + + align:start position:0% +s then if you look +up and I have let me remind it + + align:start position:0% +up and I have let me remind it + + + align:start position:0% +up and I have let me remind it +here uh we Define the heat capacity at + + align:start position:0% +here uh we Define the heat capacity at + + + align:start position:0% +here uh we Define the heat capacity at +constant uh pressure a few days ago and + + align:start position:0% +constant uh pressure a few days ago and + + + align:start position:0% +constant uh pressure a few days ago and +and that was defined as the derivative + + align:start position:0% +and that was defined as the derivative + + + align:start position:0% +and that was defined as the derivative +of the enthalpy with respect to + + align:start position:0% +of the enthalpy with respect to + + + align:start position:0% +of the enthalpy with respect to +temperature at p + + align:start position:0% +temperature at p + + + align:start position:0% +temperature at p +but if you look at how the enal the + + align:start position:0% +but if you look at how the enal the + + + align:start position:0% +but if you look at how the enal the +differential for the enthalpy is if you + + align:start position:0% +differential for the enthalpy is if you + + + align:start position:0% +differential for the enthalpy is if you +keep p and N constant DH is equal to + + align:start position:0% +keep p and N constant DH is equal to + + + align:start position:0% +keep p and N constant DH is equal to +TDs so you can substitute the DH with + + align:start position:0% +TDs so you can substitute the DH with + + + align:start position:0% +TDs so you can substitute the DH with +the TDS + + align:start position:0% +the TDS + + + align:start position:0% +the TDS +here at constant pnn so CP or actually + + align:start position:0% +here at constant pnn so CP or actually + + + align:start position:0% +here at constant pnn so CP or actually +you see here that the derivative of s + + align:start position:0% +you see here that the derivative of s + + + align:start position:0% +you see here that the derivative of s +with respect to T at constant p is CP + + align:start position:0% +with respect to T at constant p is CP + + + align:start position:0% +with respect to T at constant p is CP +over t + + align:start position:0% +over t + + + align:start position:0% +over t +this derivative is therefore the inverse + + align:start position:0% +this derivative is therefore the inverse + + + align:start position:0% +this derivative is therefore the inverse +of CP over + + align:start position:0% +of CP over + + + align:start position:0% +of CP over +T why the inverse because we just Pro + + align:start position:0% +T why the inverse because we just Pro + + + align:start position:0% +T why the inverse because we just Pro +that uh uh this derivative here is equal + + align:start position:0% +that uh uh this derivative here is equal + + + align:start position:0% +that uh uh this derivative here is equal +to uh the inverse of its uh reciprocal + + align:start position:0% +to uh the inverse of its uh reciprocal + + + align:start position:0% +to uh the inverse of its uh reciprocal +so to + + align:start position:0% +so to + + + align:start position:0% +so to +speak also this other one we can + + align:start position:0% +speak also this other one we can + + + align:start position:0% +speak also this other one we can +recognize as one of the properties that + + align:start position:0% +recognize as one of the properties that + + + align:start position:0% +recognize as one of the properties that +we have defined or + + align:start position:0% + + + + align:start position:0% + +almost by it's it's + + align:start position:0% +almost by it's it's + + + align:start position:0% +almost by it's it's +the it's the derivative of V with + + align:start position:0% +the it's the derivative of V with + + + align:start position:0% +the it's the derivative of V with +respect to pressure with the minus in + + align:start position:0% +respect to pressure with the minus in + + + align:start position:0% +respect to pressure with the minus in +front so it's the + + align:start position:0% + + + + align:start position:0% + +compressibility actually the other day + + align:start position:0% +compressibility actually the other day + + + align:start position:0% +compressibility actually the other day +we defined the isothermal + + align:start position:0% +we defined the isothermal + + + align:start position:0% +we defined the isothermal +compressibility so when you compress a + + align:start position:0% +compressibility so when you compress a + + + align:start position:0% +compressibility so when you compress a +material at constant temperature but you + + align:start position:0% +material at constant temperature but you + + + align:start position:0% +material at constant temperature but you +could also compress it at constant + + align:start position:0% +could also compress it at constant + + + align:start position:0% +could also compress it at constant +entropy that defines the isentropic + + align:start position:0% + + + + align:start position:0% + +compressibility and so here you + + align:start position:0% +compressibility and so here you + + + align:start position:0% +compressibility and so here you +recognize the inverse of the isentropic + + align:start position:0% +recognize the inverse of the isentropic + + + align:start position:0% +recognize the inverse of the isentropic +compressibility okay so first result is + + align:start position:0% +compressibility okay so first result is + + + align:start position:0% +compressibility okay so first result is +that that this uh since the determinant + + align:start position:0% +that that this uh since the determinant + + + align:start position:0% +that that this uh since the determinant +of the H determin of the H Matrix has uh + + align:start position:0% +of the H determin of the H Matrix has uh + + + align:start position:0% +of the H determin of the H Matrix has uh +to be non negative by the conditions of + + align:start position:0% +to be non negative by the conditions of + + + align:start position:0% +to be non negative by the conditions of +stability that we have uh already proved + + align:start position:0% +stability that we have uh already proved + + + align:start position:0% +stability that we have uh already proved +we have this + + align:start position:0% +we have this + + + align:start position:0% +we have this +inequality but that's not the main um + + align:start position:0% +inequality but that's not the main um + + + align:start position:0% +inequality but that's not the main um +object here I want to do now the same + + align:start position:0% +object here I want to do now the same + + + align:start position:0% +object here I want to do now the same +but by substituting here in the empty + + align:start position:0% +but by substituting here in the empty + + + align:start position:0% +but by substituting here in the empty +spaces another pair of + + align:start position:0% + + + + align:start position:0% + +variables again in such a way that + + align:start position:0% +variables again in such a way that + + + align:start position:0% +variables again in such a way that +numerator and denominator have one same + + align:start position:0% +numerator and denominator have one same + + + align:start position:0% +numerator and denominator have one same +variable like here the temperature and + + align:start position:0% +variable like here the temperature and + + + align:start position:0% +variable like here the temperature and +here the + + align:start position:0% + + + + align:start position:0% + +volume then this becomes the partial of + + align:start position:0% +volume then this becomes the partial of + + + align:start position:0% +volume then this becomes the partial of +p with respect to volume at constant + + align:start position:0% +p with respect to volume at constant + + + align:start position:0% +p with respect to volume at constant +temperature and this becomes a partial + + align:start position:0% +temperature and this becomes a partial + + + align:start position:0% +temperature and this becomes a partial +of t with respect to s set constant V + + align:start position:0% +of t with respect to s set constant V + + + align:start position:0% +of t with respect to s set constant V +and by the + + align:start position:0% +and by the + + + align:start position:0% +and by the +same definitions that we just reviewed + + align:start position:0% +same definitions that we just reviewed + + + align:start position:0% +same definitions that we just reviewed +you can show that this is equal to T + + align:start position:0% +you can show that this is equal to T + + + align:start position:0% +you can show that this is equal to T +over the heat capacity at constant + + align:start position:0% +over the heat capacity at constant + + + align:start position:0% +over the heat capacity at constant +volume and this other is and this other + + align:start position:0% +volume and this other is and this other + + + align:start position:0% +volume and this other is and this other +is uh one over the volume times the + + align:start position:0% +is uh one over the volume times the + + + align:start position:0% +is uh one over the volume times the +isothermal compressibility also this + + align:start position:0% +isothermal compressibility also this + + + align:start position:0% +isothermal compressibility also this +group must be greater than or equal to + + align:start position:0% + + + + align:start position:0% + +zero but + + align:start position:0% +zero but + + + align:start position:0% +zero but +since they came from the manipulation of + + align:start position:0% +since they came from the manipulation of + + + align:start position:0% +since they came from the manipulation of +the same + + align:start position:0% +the same + + + align:start position:0% +the same +stuff these groups must also be equal to + + align:start position:0% +stuff these groups must also be equal to + + + align:start position:0% +stuff these groups must also be equal to +one + + align:start position:0% +one + + + align:start position:0% +one +another and that by eliminating tnv + + align:start position:0% +another and that by eliminating tnv + + + align:start position:0% +another and that by eliminating tnv +which sort of cancel when you if you + + align:start position:0% +which sort of cancel when you if you + + + align:start position:0% +which sort of cancel when you if you +equate that to to + + align:start position:0% +equate that to to + + + align:start position:0% +equate that to to +this you obtain this result that the + + align:start position:0% +this you obtain this result that the + + + align:start position:0% +this you obtain this result that the +ratio of the heat + + align:start position:0% +ratio of the heat + + + align:start position:0% +ratio of the heat +capacities constant pressure and volume + + align:start position:0% +capacities constant pressure and volume + + + align:start position:0% +capacities constant pressure and volume +is equal to the ratio of the + + align:start position:0% +is equal to the ratio of the + + + align:start position:0% +is equal to the ratio of the +compressibilities + + align:start position:0% +compressibilities + + + align:start position:0% +compressibilities +temperature over entropy constant + + align:start position:0% +temperature over entropy constant + + + align:start position:0% +temperature over entropy constant +entropy temperature versus constant uh + + align:start position:0% +entropy temperature versus constant uh + + + align:start position:0% +entropy temperature versus constant uh +entropy for example if you + + align:start position:0% +entropy for example if you + + + align:start position:0% +entropy for example if you +remember like for + + align:start position:0% +remember like for + + + align:start position:0% +remember like for +air uh or for + + align:start position:0% +air uh or for + + + align:start position:0% +air uh or for +a diatomic um + + align:start position:0% +a diatomic um + + + align:start position:0% +a diatomic um +gas + + align:start position:0% +gas + + + align:start position:0% +gas +ER CP how much is CP over + + align:start position:0% +ER CP how much is CP over + + + align:start position:0% +ER CP how much is CP over +CV anybody + + align:start position:0% + + + + align:start position:0% + +remembers for air + + align:start position:0% + + + + align:start position:0% + +it's + + align:start position:0% +it's + + + align:start position:0% +it's +1.4 it it is a + + align:start position:0% +1.4 it it is a + + + align:start position:0% +1.4 it it is a +75th 7 over + + align:start position:0% +75th 7 over + + + align:start position:0% +75th 7 over +5 okay so that + + align:start position:0% +5 okay so that + + + align:start position:0% +5 okay so that +means that also the ratio of these + + align:start position:0% +means that also the ratio of these + + + align:start position:0% +means that also the ratio of these +compressibilities is 1 + + align:start position:0% + + + + align:start position:0% + +over4 we will see uh uh in a while that + + align:start position:0% +over4 we will see uh uh in a while that + + + align:start position:0% +over4 we will see uh uh in a while that +this gives us this has some importance + + align:start position:0% +this gives us this has some importance + + + align:start position:0% +this gives us this has some importance +in in a practical application which is + + align:start position:0% +in in a practical application which is + + + align:start position:0% +in in a practical application which is +uh the airs Springs that are used in + + align:start position:0% +uh the airs Springs that are used in + + + align:start position:0% +uh the airs Springs that are used in +many + + align:start position:0% +many + + + align:start position:0% +many +uh transport U device I mean Transport + + align:start position:0% +uh transport U device I mean Transport + + + align:start position:0% +uh transport U device I mean Transport +Systems Like Trains uh trucks and cars + + align:start position:0% +Systems Like Trains uh trucks and cars + + + align:start position:0% +Systems Like Trains uh trucks and cars +and so on and even + + align:start position:0% +and so on and even + + + align:start position:0% +and so on and even +bicycles uh airs Springs okay + + align:start position:0% +bicycles uh airs Springs okay + + + align:start position:0% +bicycles uh airs Springs okay +so but before we get to that uh let's + + align:start position:0% +so but before we get to that uh let's + + + align:start position:0% +so but before we get to that uh let's +keep going with um another + + align:start position:0% +keep going with um another + + + align:start position:0% +keep going with um another +uh relation that uh we can + + align:start position:0% +uh relation that uh we can + + + align:start position:0% +uh relation that uh we can +prove by again using the properties of + + align:start position:0% +prove by again using the properties of + + + align:start position:0% +prove by again using the properties of +jacobians and here is + + align:start position:0% +jacobians and here is + + + align:start position:0% +jacobians and here is +a the situation in which you have a + + align:start position:0% + + + + align:start position:0% + +surface for example a function of X Y + + align:start position:0% +surface for example a function of X Y + + + align:start position:0% +surface for example a function of X Y +and Z equal Zer represents a surface + + align:start position:0% +and Z equal Zer represents a surface + + + align:start position:0% +and Z equal Zer represents a surface +that you can represent in three + + align:start position:0% +that you can represent in three + + + align:start position:0% +that you can represent in three +dimensions XYZ so + + align:start position:0% +dimensions XYZ so + + + align:start position:0% +dimensions XYZ so +okay of course you can uh view that + + align:start position:0% +okay of course you can uh view that + + + align:start position:0% +okay of course you can uh view that +surface from various points of view by + + align:start position:0% +surface from various points of view by + + + align:start position:0% +surface from various points of view by +choosing what your base reference frame + + align:start position:0% +choosing what your base reference frame + + + align:start position:0% +choosing what your base reference frame +is and what the independent variable is + + align:start position:0% +is and what the independent variable is + + + align:start position:0% +is and what the independent variable is +so you can represent that uh surface + + align:start position:0% +so you can represent that uh surface + + + align:start position:0% +so you can represent that uh surface +also in these three alternative + + align:start position:0% +also in these three alternative + + + align:start position:0% +also in these three alternative +ways X is a function of X and why now + + align:start position:0% +ways X is a function of X and why now + + + align:start position:0% +ways X is a function of X and why now +you see what I'm saying if I uh if I + + align:start position:0% +you see what I'm saying if I uh if I + + + align:start position:0% +you see what I'm saying if I uh if I +have this + + align:start position:0% +have this + + + align:start position:0% +have this +uh surface here + + align:start position:0% +uh surface here + + + align:start position:0% +uh surface here +which is f of x y zal + + align:start position:0% +which is f of x y zal + + + align:start position:0% +which is f of x y zal +z uh I can represent it for suppose this + + align:start position:0% +z uh I can represent it for suppose this + + + align:start position:0% +z uh I can represent it for suppose this +is X Y and + + align:start position:0% +is X Y and + + + align:start position:0% +is X Y and +Z okay so this is + + align:start position:0% +Z okay so this is + + + align:start position:0% +Z okay so this is +also for every X and Y I have a value of + + align:start position:0% +also for every X and Y I have a value of + + + align:start position:0% +also for every X and Y I have a value of +Z so I can view it as a function of X of + + align:start position:0% +Z so I can view it as a function of X of + + + align:start position:0% +Z so I can view it as a function of X of +Z as a function of X and Y but I can + + align:start position:0% +Z as a function of X and Y but I can + + + align:start position:0% +Z as a function of X and Y but I can +also view it also uh from here I fix X I + + align:start position:0% +also view it also uh from here I fix X I + + + align:start position:0% +also view it also uh from here I fix X I +fix Z and that gives me a + + align:start position:0% +fix Z and that gives me a + + + align:start position:0% +fix Z and that gives me a +y so that's y function of uh Z and x and + + align:start position:0% +y so that's y function of uh Z and x and + + + align:start position:0% +y so that's y function of uh Z and x and +so on okay so these are alternative ways + + align:start position:0% +so on okay so these are alternative ways + + + align:start position:0% +so on okay so these are alternative ways +of representing in in thermodynamics the + + align:start position:0% +of representing in in thermodynamics the + + + align:start position:0% +of representing in in thermodynamics the +typical surface that is treated this way + + align:start position:0% +typical surface that is treated this way + + + align:start position:0% +typical surface that is treated this way +is the pvt relation so the the equation + + align:start position:0% +is the pvt relation so the the equation + + + align:start position:0% +is the pvt relation so the the equation +of + + align:start position:0% +of + + + align:start position:0% +of +state that particular + + align:start position:0% +state that particular + + + align:start position:0% +state that particular +equation uh that for a class of States + + align:start position:0% +equation uh that for a class of States + + + align:start position:0% +equation uh that for a class of States +like single phase + + align:start position:0% +like single phase + + + align:start position:0% +like single phase +States uh is equivalent to the uh + + align:start position:0% +States uh is equivalent to the uh + + + align:start position:0% +States uh is equivalent to the uh +fundamental + + align:start position:0% +fundamental + + + align:start position:0% +fundamental +relation and U and so it's useful + + align:start position:0% +relation and U and so it's useful + + + align:start position:0% +relation and U and so it's useful +because it's in terms of easily measur + + align:start position:0% +because it's in terms of easily measur + + + align:start position:0% +because it's in terms of easily measur +measurable properties like volume + + align:start position:0% +measurable properties like volume + + + align:start position:0% +measurable properties like volume +temperature and + + align:start position:0% +temperature and + + + align:start position:0% +temperature and +pressure + + align:start position:0% + + + + align:start position:0% + +okay all right so here we do what do we + + align:start position:0% +okay all right so here we do what do we + + + align:start position:0% +okay all right so here we do what do we +do we take take essentially ratios of + + align:start position:0% +do we take take essentially ratios of + + + align:start position:0% +do we take take essentially ratios of +stuff that are equal to + + align:start position:0% +stuff that are equal to + + + align:start position:0% +stuff that are equal to +one or actually say minus + + align:start position:0% + + + + align:start position:0% + +one so say x + + align:start position:0% +one so say x + + + align:start position:0% +one so say x +z uh and ZX the denominator by the + + align:start position:0% +z uh and ZX the denominator by the + + + align:start position:0% +z uh and ZX the denominator by the +properties of determinants that's equal + + align:start position:0% +properties of determinants that's equal + + + align:start position:0% +properties of determinants that's equal +to minus one if if I switch one uh one + + align:start position:0% +to minus one if if I switch one uh one + + + align:start position:0% +to minus one if if I switch one uh one +column it changes + + align:start position:0% +column it changes + + + align:start position:0% +column it changes +sign okay so I write this which are + + align:start position:0% +sign okay so I write this which are + + + align:start position:0% +sign okay so I write this which are +easy identities then I rearrange them in + + align:start position:0% +easy identities then I rearrange them in + + + align:start position:0% +easy identities then I rearrange them in +a in an in a more interesting way so + + align:start position:0% +a in an in a more interesting way so + + + align:start position:0% +a in an in a more interesting way so +that again I have the same variable uh + + align:start position:0% +that again I have the same variable uh + + + align:start position:0% +that again I have the same variable uh +numerator and denominator so for example + + align:start position:0% +numerator and denominator so for example + + + align:start position:0% +numerator and denominator so for example +this is the partial of X with respect to + + align:start position:0% +this is the partial of X with respect to + + + align:start position:0% +this is the partial of X with respect to +Y at constant Z this is the partial of X + + align:start position:0% +Y at constant Z this is the partial of X + + + align:start position:0% +Y at constant Z this is the partial of X +with respect I'm sorry y with respect to + + align:start position:0% +with respect I'm sorry y with respect to + + + align:start position:0% +with respect I'm sorry y with respect to +Z at constant X and this is partial of Z + + align:start position:0% +Z at constant X and this is partial of Z + + + align:start position:0% +Z at constant X and this is partial of Z +respect to x constant + + align:start position:0% +respect to x constant + + + align:start position:0% +respect to x constant +Y which is written here + + align:start position:0% +Y which is written here + + + align:start position:0% +Y which is written here +and if you multiply minus one three + + align:start position:0% +and if you multiply minus one three + + + align:start position:0% +and if you multiply minus one three +times you get minus one so this is + + align:start position:0% +times you get minus one so this is + + + align:start position:0% +times you get minus one so this is +called the cyc cyclic relation and if + + align:start position:0% +called the cyc cyclic relation and if + + + align:start position:0% +called the cyc cyclic relation and if +you apply it to + + align:start position:0% +you apply it to + + + align:start position:0% +you apply it to +the uh pvt relation equation of State + + align:start position:0% +the uh pvt relation equation of State + + + align:start position:0% +the uh pvt relation equation of State +here is what you + + align:start position:0% + + + + align:start position:0% + +get and for example you could you could + + align:start position:0% +get and for example you could you could + + + align:start position:0% +get and for example you could you could +apply it you remember that the one of + + align:start position:0% +apply it you remember that the one of + + + align:start position:0% +apply it you remember that the one of +the Maxwell relations that we said could + + align:start position:0% +the Maxwell relations that we said could + + + align:start position:0% +the Maxwell relations that we said could +be useful to measure entropy because it + + align:start position:0% +be useful to measure entropy because it + + + align:start position:0% +be useful to measure entropy because it +has it gives a entropy + + align:start position:0% +has it gives a entropy + + + align:start position:0% +has it gives a entropy +changes that you can measure by + + align:start position:0% +changes that you can measure by + + + align:start position:0% +changes that you can measure by +measuring volume changes pressure + + align:start position:0% +measuring volume changes pressure + + + align:start position:0% +measuring volume changes pressure +changes temperature changes at constant + + align:start position:0% +changes temperature changes at constant + + + align:start position:0% +changes temperature changes at constant +temperature at constant volume so this + + align:start position:0% +temperature at constant volume so this + + + align:start position:0% +temperature at constant volume so this +is somehow uh the basis of a an + + align:start position:0% +is somehow uh the basis of a an + + + align:start position:0% +is somehow uh the basis of a an +instrument that you could call an + + align:start position:0% +instrument that you could call an + + + align:start position:0% +instrument that you could call an +entropy + + align:start position:0% +entropy + + + align:start position:0% +entropy +meter well by applying this cyclic + + align:start position:0% +meter well by applying this cyclic + + + align:start position:0% +meter well by applying this cyclic +relation and I'm not going to the + + align:start position:0% +relation and I'm not going to the + + + align:start position:0% +relation and I'm not going to the +details but I'll let you uh show + + align:start position:0% +details but I'll let you uh show + + + align:start position:0% +details but I'll let you uh show +that um you prove that this derivative + + align:start position:0% +that um you prove that this derivative + + + align:start position:0% +that um you prove that this derivative +is equal to the ratio of alpha p over + + align:start position:0% +is equal to the ratio of alpha p over + + + align:start position:0% +is equal to the ratio of alpha p over +Capa T so it's the + + align:start position:0% +Capa T so it's the + + + align:start position:0% +Capa T so it's the +um isobaric coefficient of expansion + + align:start position:0% +um isobaric coefficient of expansion + + + align:start position:0% +um isobaric coefficient of expansion +Alpha over the isothermal + + align:start position:0% +Alpha over the isothermal + + + align:start position:0% +Alpha over the isothermal +compressibility of your + + align:start position:0% +compressibility of your + + + align:start position:0% +compressibility of your +material for example for a + + align:start position:0% +material for example for a + + + align:start position:0% +material for example for a +gas I mean if I can write + + align:start position:0% +gas I mean if I can write + + + align:start position:0% +gas I mean if I can write +the ideal gas + + align:start position:0% + + + + align:start position:0% + +relation you can view that as a as a v + + align:start position:0% +relation you can view that as a as a v + + + align:start position:0% +relation you can view that as a as a v +as a function of T and + + align:start position:0% +as a function of T and + + + align:start position:0% +as a function of T and +P and + + align:start position:0% + + + + align:start position:0% + +N right so it's + + align:start position:0% +N right so it's + + + align:start position:0% +N right so it's +nrt over + + align:start position:0% +nrt over + + + align:start position:0% +nrt over +P so it's easy to compute for example + + align:start position:0% +P so it's easy to compute for example + + + align:start position:0% +P so it's easy to compute for example +Alpha + + align:start position:0% +Alpha + + + align:start position:0% +Alpha +p Alpha p is 1 / V the derivative of V + + align:start position:0% +p Alpha p is 1 / V the derivative of V + + + align:start position:0% +p Alpha p is 1 / V the derivative of V +with respect to + + align:start position:0% +with respect to + + + align:start position:0% +with respect to +T at constant pressure so it's how much + + align:start position:0% +T at constant pressure so it's how much + + + align:start position:0% +T at constant pressure so it's how much +the uh uh the + + align:start position:0% +the uh uh the + + + align:start position:0% +the uh uh the +expansion for a given U increasing + + align:start position:0% +expansion for a given U increasing + + + align:start position:0% +expansion for a given U increasing +temperature all right so it's one / V + + align:start position:0% +temperature all right so it's one / V + + + align:start position:0% +temperature all right so it's one / V +the derivative of V of V with respect to + + align:start position:0% +the derivative of V of V with respect to + + + align:start position:0% +the derivative of V of V with respect to +T is easy it's + + align:start position:0% +T is easy it's + + + align:start position:0% +T is easy it's +NR over + + align:start position:0% +NR over + + + align:start position:0% +NR over +p and if you use that again this is 1 / + + align:start position:0% + + + + align:start position:0% + +T Capa + + align:start position:0% +T Capa + + + align:start position:0% +T Capa +T is + + align:start position:0% + + + + align:start position:0% + +minus 1 / V the derivative of V with + + align:start position:0% +minus 1 / V the derivative of V with + + + align:start position:0% +minus 1 / V the derivative of V with +respect to P at constant + + align:start position:0% +respect to P at constant + + + align:start position:0% +respect to P at constant +T all right we can also do that + + align:start position:0% +T all right we can also do that + + + align:start position:0% +T all right we can also do that +derivative uh the derivative of this + + align:start position:0% +derivative uh the derivative of this + + + align:start position:0% +derivative uh the derivative of this +with respect to p + + align:start position:0% +with respect to p + + + align:start position:0% +with respect to p +is + + align:start position:0% +is + + + align:start position:0% +is +minus + + align:start position:0% +minus + + + align:start position:0% +minus +nrt / p ^ + + align:start position:0% + + + + align:start position:0% + +2 I apply that + + align:start position:0% +2 I apply that + + + align:start position:0% +2 I apply that +again and the minus goes away with the + + align:start position:0% +again and the minus goes away with the + + + align:start position:0% +again and the minus goes away with the +minus one V goes away I'm left with one + + align:start position:0% +minus one V goes away I'm left with one + + + align:start position:0% +minus one V goes away I'm left with one +/ + + align:start position:0% + + + + align:start position:0% + +P so Alpha and Kappa for ideal gases are + + align:start position:0% +P so Alpha and Kappa for ideal gases are + + + align:start position:0% +P so Alpha and Kappa for ideal gases are +relatively simple + + align:start position:0% +relatively simple + + + align:start position:0% +relatively simple +and uh um and so this gives that that + + align:start position:0% +and uh um and so this gives that that + + + align:start position:0% +and uh um and so this gives that that +derivative here is equal to P / + + align:start position:0% + + + + align:start position:0% + +T okay for a + + align:start position:0% + + + + align:start position:0% + +gas there is + + align:start position:0% +gas there is + + + align:start position:0% +gas there is +another interesting + + align:start position:0% +another interesting + + + align:start position:0% +another interesting +relation that you can prove + + align:start position:0% +relation that you can prove + + + align:start position:0% +relation that you can prove +not so easily but relatively uh + + align:start position:0% +not so easily but relatively uh + + + align:start position:0% +not so easily but relatively uh +straightforward by + + align:start position:0% +straightforward by + + + align:start position:0% +straightforward by +using uh + + align:start position:0% +using uh + + + align:start position:0% +using uh +the + + align:start position:0% + + + + align:start position:0% + +jacobians it's the Mayer relation which + + align:start position:0% +jacobians it's the Mayer relation which + + + align:start position:0% +jacobians it's the Mayer relation which +relates CP CV Alpha p and Capa + + align:start position:0% +relates CP CV Alpha p and Capa + + + align:start position:0% +relates CP CV Alpha p and Capa +te and of course temperature and + + align:start position:0% +te and of course temperature and + + + align:start position:0% +te and of course temperature and +volume and here you see this is just the + + align:start position:0% +volume and here you see this is just the + + + align:start position:0% +volume and here you see this is just the +definition of CP + + align:start position:0% +definition of CP + + + align:start position:0% +definition of CP +we write this derivative in terms of a + + align:start position:0% +we write this derivative in terms of a + + + align:start position:0% +we write this derivative in terms of a +Jacobian with the with the property that + + align:start position:0% +Jacobian with the with the property that + + + align:start position:0% +Jacobian with the with the property that +is kept constant repeated numerator and + + align:start position:0% +is kept constant repeated numerator and + + + align:start position:0% +is kept constant repeated numerator and +do denominator then we shift leave the + + align:start position:0% +do denominator then we shift leave the + + + align:start position:0% +do denominator then we shift leave the +empty space and then we search and now + + align:start position:0% +empty space and then we search and now + + + align:start position:0% +empty space and then we search and now +the CH the choice of what to put there + + align:start position:0% +the CH the choice of what to put there + + + align:start position:0% +the CH the choice of what to put there +is sort of a smart you have to have some + + align:start position:0% +is sort of a smart you have to have some + + + align:start position:0% +is sort of a smart you have to have some +uh just trial and error or some + + align:start position:0% +uh just trial and error or some + + + align:start position:0% +uh just trial and error or some +experience on how to choose + + align:start position:0% +experience on how to choose + + + align:start position:0% +experience on how to choose +it but here if you for example we choose + + align:start position:0% +it but here if you for example we choose + + + align:start position:0% +it but here if you for example we choose +to to to select T and + + align:start position:0% +to to to select T and + + + align:start position:0% +to to to select T and +V the second one has a repeated um + + align:start position:0% +V the second one has a repeated um + + + align:start position:0% +V the second one has a repeated um +variable numerator denominator so it is + + align:start position:0% +variable numerator denominator so it is + + + align:start position:0% +variable numerator denominator so it is +a partial derivative and again we find + + align:start position:0% +a partial derivative and again we find + + + align:start position:0% +a partial derivative and again we find +that it's related to Capa T the first + + align:start position:0% +that it's related to Capa T the first + + + align:start position:0% +that it's related to Capa T the first +determinant has four different variables + + align:start position:0% +determinant has four different variables + + + align:start position:0% +determinant has four different variables +so we write it here in terms of its + + align:start position:0% + + + + align:start position:0% + +definition and then these various + + align:start position:0% +definition and then these various + + + align:start position:0% +definition and then these various +entries can be recognized as + + align:start position:0% +entries can be recognized as + + + align:start position:0% +entries can be recognized as +those properties for example this is CV + + align:start position:0% +those properties for example this is CV + + + align:start position:0% +those properties for example this is CV +over + + align:start position:0% +over + + + align:start position:0% +over +T + + align:start position:0% +T + + + align:start position:0% +T +um this we just prove this Alpha over + + align:start position:0% +um this we just prove this Alpha over + + + align:start position:0% +um this we just prove this Alpha over +Kappa + + align:start position:0% +Kappa + + + align:start position:0% +Kappa +T this is the same because of the + + align:start position:0% +T this is the same because of the + + + align:start position:0% +T this is the same because of the +symmetry of um of the S determinant and + + align:start position:0% +symmetry of um of the S determinant and + + + align:start position:0% +symmetry of um of the S determinant and +or because of the max relations which is + + align:start position:0% +or because of the max relations which is + + + align:start position:0% +or because of the max relations which is +the same and this is one over Capa T so + + align:start position:0% +the same and this is one over Capa T so + + + align:start position:0% +the same and this is one over Capa T so +now you compute the determinant you get + + align:start position:0% +now you compute the determinant you get + + + align:start position:0% +now you compute the determinant you get +that you place it here + + align:start position:0% +that you place it here + + + align:start position:0% +that you place it here +and out comes to my + + align:start position:0% + + + + align:start position:0% + +relation okay yeah so what what's the my + + align:start position:0% +relation okay yeah so what what's the my + + + align:start position:0% +relation okay yeah so what what's the my +relation for a + + align:start position:0% + + + + align:start position:0% + +gas what's the relation between c c + + align:start position:0% + + + + align:start position:0% + +CP and CV for a for + + align:start position:0% + + + + align:start position:0% + +gas no + + align:start position:0% + + + + align:start position:0% + +what the + + align:start position:0% + + + + align:start position:0% + +water how about + + align:start position:0% +water how about + + + align:start position:0% +water how about +R the gas + + align:start position:0% +R the gas + + + align:start position:0% +R the gas +constant + + align:start position:0% +constant + + + align:start position:0% +constant +usually you don't do heat + + align:start position:0% +usually you don't do heat + + + align:start position:0% +usually you don't do heat +capacities uh we we uh we you we do + + align:start position:0% +capacities uh we we uh we you we do + + + align:start position:0% +capacities uh we we uh we you we do +specific Heats so that's CP small C is + + align:start position:0% +specific Heats so that's CP small C is + + + align:start position:0% +specific Heats so that's CP small C is +Capital C over + + align:start position:0% +Capital C over + + + align:start position:0% +Capital C over +n and uh CV small C heat + + align:start position:0% +n and uh CV small C heat + + + align:start position:0% +n and uh CV small C heat +capacity I'm sorry specific heat is the + + align:start position:0% +capacity I'm sorry specific heat is the + + + align:start position:0% +capacity I'm sorry specific heat is the +CV over + + align:start position:0% +CV over + + + align:start position:0% +CV over +n and then the relation my relation is + + align:start position:0% +n and then the relation my relation is + + + align:start position:0% +n and then the relation my relation is +that CP equals CV plus the gas constant + + align:start position:0% +that CP equals CV plus the gas constant + + + align:start position:0% +that CP equals CV plus the gas constant +but let's prove it because we said that + + align:start position:0% +but let's prove it because we said that + + + align:start position:0% +but let's prove it because we said that +U uh we have it there so we have we have + + align:start position:0% +U uh we have it there so we have we have + + + align:start position:0% +U uh we have it there so we have we have +to compute V + + align:start position:0% +to compute V + + + align:start position:0% +to compute V +uh what is it the VT Alpha + + align:start position:0% + + + + align:start position:0% + +squ over Capa + + align:start position:0% +squ over Capa + + + align:start position:0% +squ over Capa +T all right which is this term here + + align:start position:0% +T all right which is this term here + + + align:start position:0% +T all right which is this term here +which is the difference between the two + + align:start position:0% +which is the difference between the two + + + align:start position:0% +which is the difference between the two +capacitors so Alpha so that's + + align:start position:0% +capacitors so Alpha so that's + + + align:start position:0% +capacitors so Alpha so that's +VT uh Alpha is 1 / T so got T squ + + align:start position:0% +VT uh Alpha is 1 / T so got T squ + + + align:start position:0% +VT uh Alpha is 1 / T so got T squ +here and Kappa is one over P so I got a + + align:start position:0% +here and Kappa is one over P so I got a + + + align:start position:0% +here and Kappa is one over P so I got a +p there + + align:start position:0% +p there + + + align:start position:0% +p there +so that goes with that and hopefully + + align:start position:0% +so that goes with that and hopefully + + + align:start position:0% +so that goes with that and hopefully +since PV is equal to an + + align:start position:0% +since PV is equal to an + + + align:start position:0% +since PV is equal to an +nrt divided by T gives + + align:start position:0% + + + + align:start position:0% + +NR I see a lot of rust in your minds + + align:start position:0% +NR I see a lot of rust in your minds + + + align:start position:0% +NR I see a lot of rust in your minds +about about previous thermal that's + + align:start position:0% +about about previous thermal that's + + + align:start position:0% +about about previous thermal that's +okay + + align:start position:0% +okay + + + align:start position:0% +okay +uh all right + + align:start position:0% + + + + align:start position:0% + +so done + + align:start position:0% +so done + + + align:start position:0% +so done +with these properties I want to go back + + align:start position:0% +with these properties I want to go back + + + align:start position:0% +with these properties I want to go back +to the subject of available + + align:start position:0% +to the subject of available + + + align:start position:0% +to the subject of available +energy you remember what we've done + + align:start position:0% +energy you remember what we've done + + + align:start position:0% +energy you remember what we've done +um I forget now if it was the previous + + align:start position:0% +um I forget now if it was the previous + + + align:start position:0% +um I forget now if it was the previous +lecture or the one + + align:start position:0% + + + + align:start position:0% + +before + + align:start position:0% + + + + align:start position:0% + +um available + + align:start position:0% +um available + + + align:start position:0% +um available +energy this is the setup in which I have + + align:start position:0% +energy this is the setup in which I have + + + align:start position:0% +energy this is the setup in which I have +a system and a + + align:start position:0% +a system and a + + + align:start position:0% +a system and a +reservoir and they undergo a a weight + + align:start position:0% +reservoir and they undergo a a weight + + + align:start position:0% +reservoir and they undergo a a weight +process and we know that if the process + + align:start position:0% +process and we know that if the process + + + align:start position:0% +process and we know that if the process +the weight process is + + align:start position:0% + + + + align:start position:0% + +reversible uh we can + + align:start position:0% +reversible uh we can + + + align:start position:0% +reversible uh we can +extract uh the maximum amount of energy + + align:start position:0% +extract uh the maximum amount of energy + + + align:start position:0% +extract uh the maximum amount of energy +when the system ends in a in a mutual + + align:start position:0% +when the system ends in a in a mutual + + + align:start position:0% +when the system ends in a in a mutual +equilibrium state with the environment + + align:start position:0% +equilibrium state with the environment + + + align:start position:0% +equilibrium state with the environment +with the rest + + align:start position:0% +with the rest + + + align:start position:0% +with the rest +work here is instead we are going to + + align:start position:0% +work here is instead we are going to + + + align:start position:0% +work here is instead we are going to +adopt two different states two arbitrary + + align:start position:0% +adopt two different states two arbitrary + + + align:start position:0% +adopt two different states two arbitrary +States so initial and + + align:start position:0% +States so initial and + + + align:start position:0% +States so initial and +final and you ask yourself well if my + + align:start position:0% +final and you ask yourself well if my + + + align:start position:0% +final and you ask yourself well if my +system has to go from A1 to + + align:start position:0% +system has to go from A1 to + + + align:start position:0% +system has to go from A1 to +A2 and it has available the interaction + + align:start position:0% +A2 and it has available the interaction + + + align:start position:0% +A2 and it has available the interaction +with the this thermal + + align:start position:0% +with the this thermal + + + align:start position:0% +with the this thermal +Reservoir what is the maximum weight + + align:start position:0% +Reservoir what is the maximum weight + + + align:start position:0% +Reservoir what is the maximum weight +lifted it can + + align:start position:0% +lifted it can + + + align:start position:0% +lifted it can +do or if it cannot lift the weight + + align:start position:0% + + + + align:start position:0% + +what is the minimum weight + + align:start position:0% +what is the minimum weight + + + align:start position:0% +what is the minimum weight +lowering that is required so as to + + align:start position:0% +lowering that is required so as to + + + align:start position:0% +lowering that is required so as to +achieve that + + align:start position:0% + + + + align:start position:0% + +change and we have seen that um all any + + align:start position:0% +change and we have seen that um all any + + + align:start position:0% +change and we have seen that um all any +I mean this class of problems what's the + + align:start position:0% +I mean this class of problems what's the + + + align:start position:0% +I mean this class of problems what's the +maximum work what's the minimum + + align:start position:0% +maximum work what's the minimum + + + align:start position:0% +maximum work what's the minimum +work are always solved by writing an + + align:start position:0% +work are always solved by writing an + + + align:start position:0% +work are always solved by writing an +energy balance + + align:start position:0% +energy balance + + + align:start position:0% +energy balance +an entropy + + align:start position:0% +an entropy + + + align:start position:0% +an entropy +balance and also inserting as much as we + + align:start position:0% +balance and also inserting as much as we + + + align:start position:0% +balance and also inserting as much as we +know about the properties of the systems + + align:start position:0% +know about the properties of the systems + + + align:start position:0% +know about the properties of the systems +involved in this case we have a + + align:start position:0% +involved in this case we have a + + + align:start position:0% +involved in this case we have a +reservoir for which we know the + + align:start position:0% +reservoir for which we know the + + + align:start position:0% +reservoir for which we know the +fundamental relation is this linear + + align:start position:0% +fundamental relation is this linear + + + align:start position:0% +fundamental relation is this linear +relationship between energy and + + align:start position:0% + + + + align:start position:0% + +entropy and by the + + align:start position:0% +entropy and by the + + + align:start position:0% +entropy and by the +way uh usually in + + align:start position:0% + + + + align:start position:0% + +uh often I mean in in uh especially in + + align:start position:0% +uh often I mean in in uh especially in + + + align:start position:0% +uh often I mean in in uh especially in +in the + + align:start position:0% +in the + + + align:start position:0% +in the +physics language what we call thermal + + align:start position:0% +physics language what we call thermal + + + align:start position:0% +physics language what we call thermal +Reservoir it's called The Heat + + align:start position:0% +Reservoir it's called The Heat + + + align:start position:0% +Reservoir it's called The Heat +buff okay now you realize that uh we + + align:start position:0% +buff okay now you realize that uh we + + + align:start position:0% +buff okay now you realize that uh we +defined uh uh the heat interaction so + + align:start position:0% +defined uh uh the heat interaction so + + + align:start position:0% +defined uh uh the heat interaction so +that keep from a to + + align:start position:0% +that keep from a to + + + align:start position:0% +that keep from a to +me uh so that + + align:start position:0% +me uh so that + + + align:start position:0% +me uh so that +uh + + align:start position:0% + + + + align:start position:0% + +the okay so that if you are I want how + + align:start position:0% +the okay so that if you are I want how + + + align:start position:0% +the okay so that if you are I want how +much entropy is + + align:start position:0% + + + + align:start position:0% + +transferred you get it because the ratio + + align:start position:0% +transferred you get it because the ratio + + + align:start position:0% +transferred you get it because the ratio +between energy and entropy uh + + align:start position:0% +between energy and entropy uh + + + align:start position:0% +between energy and entropy uh +transferred in a heat interaction is + + align:start position:0% +transferred in a heat interaction is + + + align:start position:0% +transferred in a heat interaction is +equal to the temperature at which that + + align:start position:0% +equal to the temperature at which that + + + align:start position:0% +equal to the temperature at which that +transfer + + align:start position:0% +transfer + + + align:start position:0% +transfer +occurs + + align:start position:0% +occurs + + + align:start position:0% +occurs +okay now the + + align:start position:0% +okay now the + + + align:start position:0% +okay now the +reservoir you can write the fundamental + + align:start position:0% +reservoir you can write the fundamental + + + align:start position:0% +reservoir you can write the fundamental +relation for the reservoir + + align:start position:0% +relation for the reservoir + + + align:start position:0% +relation for the reservoir +uh this + + align:start position:0% + + + + align:start position:0% + +way so you + + align:start position:0% +way so you + + + align:start position:0% +way so you +see the why they call it heat buff + + align:start position:0% +see the why they call it heat buff + + + align:start position:0% +see the why they call it heat buff +because the uh heat Reservoir is ready + + align:start position:0% +because the uh heat Reservoir is ready + + + align:start position:0% +because the uh heat Reservoir is ready +to provide a heat interaction if you + + align:start position:0% +to provide a heat interaction if you + + + align:start position:0% +to provide a heat interaction if you +extract energy at its + + align:start position:0% +extract energy at its + + + align:start position:0% +extract energy at its +temperature uh then it provides also the + + align:start position:0% +temperature uh then it provides also the + + + align:start position:0% +temperature uh then it provides also the +entropy and in in the right ratio so + + align:start position:0% +entropy and in in the right ratio so + + + align:start position:0% +entropy and in in the right ratio so +that you have a heat interaction at the + + align:start position:0% +that you have a heat interaction at the + + + align:start position:0% +that you have a heat interaction at the +temperature of the + + align:start position:0% +temperature of the + + + align:start position:0% +temperature of the +reservoir so it's a heat buff in the + + align:start position:0% +reservoir so it's a heat buff in the + + + align:start position:0% +reservoir so it's a heat buff in the +sense that it can provide uh heat I mean + + align:start position:0% +sense that it can provide uh heat I mean + + + align:start position:0% +sense that it can provide uh heat I mean +so that's at least + + align:start position:0% + + + + align:start position:0% + +justifies that's the reading of the ter + + align:start position:0% +justifies that's the reading of the ter + + + align:start position:0% +justifies that's the reading of the ter +that's the my justification of that + + align:start position:0% +that's the my justification of that + + + align:start position:0% +that's the my justification of that +language it is not a reservoir of heat + + align:start position:0% + + + + align:start position:0% + +though in a in the sense that + + align:start position:0% +though in a in the sense that + + + align:start position:0% +though in a in the sense that +heat is not a a form of energy it is a + + align:start position:0% +heat is not a a form of energy it is a + + + align:start position:0% +heat is not a a form of energy it is a +form of energy + + align:start position:0% +form of energy + + + align:start position:0% +form of energy +transfer you cannot store heat you store + + align:start position:0% +transfer you cannot store heat you store + + + align:start position:0% +transfer you cannot store heat you store +energy okay you transfer energy in the + + align:start position:0% +energy okay you transfer energy in the + + + align:start position:0% +energy okay you transfer energy in the +form of heat when you have an + + align:start position:0% +form of heat when you have an + + + align:start position:0% +form of heat when you have an +interaction of that + + align:start position:0% +interaction of that + + + align:start position:0% +interaction of that +form so the language is is important and + + align:start position:0% +form so the language is is important and + + + align:start position:0% +form so the language is is important and +lose language is okay if you understand + + align:start position:0% +lose language is okay if you understand + + + align:start position:0% +lose language is okay if you understand +what you're doing if it is too loose and + + align:start position:0% +what you're doing if it is too loose and + + + align:start position:0% +what you're doing if it is too loose and +if you + + align:start position:0% +if you + + + align:start position:0% +if you +assign to this language uh two popular + + align:start position:0% +assign to this language uh two popular + + + align:start position:0% +assign to this language uh two popular +meaning then you get a lot of + + align:start position:0% + + + + align:start position:0% + +confusion this is + + align:start position:0% +confusion this is + + + align:start position:0% +confusion this is +why + + align:start position:0% +why + + + align:start position:0% +why +I one of our objectives here is to try + + align:start position:0% +I one of our objectives here is to try + + + align:start position:0% +I one of our objectives here is to try +to be as careful as possible with the + + align:start position:0% + + + + align:start position:0% + +language and by the way uh my + + align:start position:0% +language and by the way uh my + + + align:start position:0% +language and by the way uh my +um sincere congratulations for how good + + align:start position:0% +um sincere congratulations for how good + + + align:start position:0% +um sincere congratulations for how good +you're doing in your uh + + align:start position:0% + + + + align:start position:0% + +homeworks + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so the the + + align:start position:0% +so the the + + + align:start position:0% +so the the +work that you by solving this system of + + align:start position:0% +work that you by solving this system of + + + align:start position:0% +work that you by solving this system of +equations we already said that we we + + align:start position:0% +equations we already said that we we + + + align:start position:0% +equations we already said that we we +find an expression for the + + align:start position:0% +find an expression for the + + + align:start position:0% +find an expression for the +work which is uh H which is a term + + align:start position:0% +work which is uh H which is a term + + + align:start position:0% +work which is uh H which is a term +related to irreversibility entropy + + align:start position:0% +related to irreversibility entropy + + + align:start position:0% +related to irreversibility entropy +produced by irreversibility which is not + + align:start position:0% +produced by irreversibility which is not + + + align:start position:0% +produced by irreversibility which is not +there if the process is reversible and + + align:start position:0% +there if the process is reversible and + + + align:start position:0% +there if the process is reversible and +that's typically the best you can do + + align:start position:0% +that's typically the best you can do + + + align:start position:0% +that's typically the best you can do +whether you have to spend energy or + + align:start position:0% +whether you have to spend energy or + + + align:start position:0% +whether you have to spend energy or +produce uh um mechanical energy + + align:start position:0% +produce uh um mechanical energy + + + align:start position:0% +produce uh um mechanical energy +uh you get the best always when you do + + align:start position:0% +uh you get the best always when you do + + + align:start position:0% +uh you get the best always when you do +it uh reversibly so if you have to + + align:start position:0% +it uh reversibly so if you have to + + + align:start position:0% +it uh reversibly so if you have to +extract energy if you can extract energy + + align:start position:0% +extract energy if you can extract energy + + + align:start position:0% +extract energy if you can extract energy +you extract the max you should do the + + align:start position:0% +you extract the max you should do the + + + align:start position:0% +you extract the max you should do the +reversable process if you have to spend + + align:start position:0% +reversable process if you have to spend + + + align:start position:0% +reversable process if you have to spend +energy in order to obtain uh a change of + + align:start position:0% +energy in order to obtain uh a change of + + + align:start position:0% +energy in order to obtain uh a change of +state for example heating up uh some + + align:start position:0% +state for example heating up uh some + + + align:start position:0% +state for example heating up uh some +water it's a a task that requires uh + + align:start position:0% +water it's a a task that requires uh + + + align:start position:0% +water it's a a task that requires uh +spending energy you can ask yourself + + align:start position:0% +spending energy you can ask yourself + + + align:start position:0% +spending energy you can ask yourself +what is the minimum uh uh work that you + + align:start position:0% +what is the minimum uh uh work that you + + + align:start position:0% +what is the minimum uh uh work that you +need to spend in order to heat up that + + align:start position:0% +need to spend in order to heat up that + + + align:start position:0% +need to spend in order to heat up that +uh that water + + align:start position:0% +uh that water + + + align:start position:0% +uh that water +and if you do + + align:start position:0% + + + + align:start position:0% + +that uh maybe when we do uh next time + + align:start position:0% +that uh maybe when we do uh next time + + + align:start position:0% +that uh maybe when we do uh next time +the review on aies uh we + + align:start position:0% +the review on aies uh we + + + align:start position:0% +the review on aies uh we +uh + + align:start position:0% + + + + align:start position:0% + +we will'll see our efficient certain + + align:start position:0% +we will'll see our efficient certain + + + align:start position:0% +we will'll see our efficient certain +ways we have to heat up + + align:start position:0% +ways we have to heat up + + + align:start position:0% +ways we have to heat up +water + + align:start position:0% + + + + align:start position:0% + +uh + + align:start position:0% +uh + + + align:start position:0% +uh +okay now the maximum the reversible work + + align:start position:0% +okay now the maximum the reversible work + + + align:start position:0% +okay now the maximum the reversible work +is the difference between the available + + align:start position:0% +is the difference between the available + + + align:start position:0% +is the difference between the available +energies of the two uh states of your + + align:start position:0% +energies of the two uh states of your + + + align:start position:0% +energies of the two uh states of your +system it's also the + + align:start position:0% +system it's also the + + + align:start position:0% +system it's also the +difference in this availability function + + align:start position:0% +difference in this availability function + + + align:start position:0% +difference in this availability function +gamma that is energy minus entropy + + align:start position:0% +gamma that is energy minus entropy + + + align:start position:0% +gamma that is energy minus entropy +multiplied by the temperature of the + + align:start position:0% + + + + align:start position:0% + +resare well called the availab canonical + + align:start position:0% +resare well called the availab canonical + + + align:start position:0% +resare well called the availab canonical +AV availability function and that we + + align:start position:0% +AV availability function and that we + + + align:start position:0% +AV availability function and that we +have seen that uh if you try to um + + align:start position:0% +have seen that uh if you try to um + + + align:start position:0% +have seen that uh if you try to um +represented + + align:start position:0% +represented + + + align:start position:0% +represented +graphically it acquires an absolute + + align:start position:0% +graphically it acquires an absolute + + + align:start position:0% +graphically it acquires an absolute +minimum uh at the state in which a + + align:start position:0% +minimum uh at the state in which a + + + align:start position:0% +minimum uh at the state in which a +system is in mutual equilibrium with the + + align:start position:0% +system is in mutual equilibrium with the + + + align:start position:0% +system is in mutual equilibrium with the +reservoir so uh we by by exploiting this + + align:start position:0% +reservoir so uh we by by exploiting this + + + align:start position:0% +reservoir so uh we by by exploiting this +this idea that this is a + + align:start position:0% +this idea that this is a + + + align:start position:0% +this idea that this is a +minimum uh + + align:start position:0% +minimum uh + + + align:start position:0% +minimum uh +we we extract information about for + + align:start position:0% +we we extract information about for + + + align:start position:0% +we we extract information about for +example the + + align:start position:0% +example the + + + align:start position:0% +example the +uh concavity of the + + align:start position:0% +uh concavity of the + + + align:start position:0% +uh concavity of the +fundamental relation + + align:start position:0% +fundamental relation + + + align:start position:0% +fundamental relation +By + + align:start position:0% +By + + + align:start position:0% +By +devising changes so you start from this + + align:start position:0% +devising changes so you start from this + + + align:start position:0% +devising changes so you start from this +uh Mutual equilibrium State and you move + + align:start position:0% +uh Mutual equilibrium State and you move + + + align:start position:0% +uh Mutual equilibrium State and you move +anywhere else in uh an available one of + + align:start position:0% +anywhere else in uh an available one of + + + align:start position:0% +anywhere else in uh an available one of +the possible states of your system a + + align:start position:0% +the possible states of your system a + + + align:start position:0% +the possible states of your system a +wherever you + + align:start position:0% +wherever you + + + align:start position:0% +wherever you +move gamma must + + align:start position:0% +move gamma must + + + align:start position:0% +move gamma must +increase and so for example we chose uh + + align:start position:0% +increase and so for example we chose uh + + + align:start position:0% +increase and so for example we chose uh +particular changes and we prove that uh + + align:start position:0% +particular changes and we prove that uh + + + align:start position:0% +particular changes and we prove that uh +with those particular changes just you + + align:start position:0% +with those particular changes just you + + + align:start position:0% +with those particular changes just you +can find that + + align:start position:0% +can find that + + + align:start position:0% +can find that +uh the second differential of the + + align:start position:0% +uh the second differential of the + + + align:start position:0% +uh the second differential of the +energy with respect to V and so fixed + + align:start position:0% +energy with respect to V and so fixed + + + align:start position:0% +energy with respect to V and so fixed +sorry fixed then and V the second + + align:start position:0% +sorry fixed then and V the second + + + align:start position:0% +sorry fixed then and V the second +differential so the concavity here is + + align:start position:0% +differential so the concavity here is + + + align:start position:0% +differential so the concavity here is +positive you can do it also from the + + align:start position:0% +positive you can do it also from the + + + align:start position:0% +positive you can do it also from the +other point of view so we say you find + + align:start position:0% +other point of view so we say you find + + + align:start position:0% +other point of view so we say you find +that the second differential of s with + + align:start position:0% +that the second differential of s with + + + align:start position:0% +that the second differential of s with +respect to uh at fixed vnn is negative + + align:start position:0% +respect to uh at fixed vnn is negative + + + align:start position:0% +respect to uh at fixed vnn is negative +okay + + align:start position:0% +okay + + + align:start position:0% +okay +now yeah we also apply that to prove uh + + align:start position:0% +now yeah we also apply that to prove uh + + + align:start position:0% +now yeah we also apply that to prove uh +uh + + align:start position:0% +uh + + + align:start position:0% +uh +but for example that the specific I mean + + align:start position:0% +but for example that the specific I mean + + + align:start position:0% +but for example that the specific I mean +the heat capacities are uh non- + + align:start position:0% + + + + align:start position:0% + +negative and we + + align:start position:0% +negative and we + + + align:start position:0% +negative and we +proved the first part this is just the + + align:start position:0% +proved the first part this is just the + + + align:start position:0% +proved the first part this is just the +first part of the of the theorem by CH + + align:start position:0% + + + + align:start position:0% + +Brown today we'll uh we'll do also a + + align:start position:0% +Brown today we'll uh we'll do also a + + + align:start position:0% +Brown today we'll uh we'll do also a +second part which is + + align:start position:0% +second part which is + + + align:start position:0% +second part which is +um even more + + align:start position:0% +um even more + + + align:start position:0% +um even more +interesting so the first part was any + + align:start position:0% +interesting so the first part was any + + + align:start position:0% +interesting so the first part was any +way that um if you if you perturb your + + align:start position:0% +way that um if you if you perturb your + + + align:start position:0% +way that um if you if you perturb your +the state of your system which is + + align:start position:0% +the state of your system which is + + + align:start position:0% +the state of your system which is +initially in mutual equilibrium with the + + align:start position:0% +initially in mutual equilibrium with the + + + align:start position:0% +initially in mutual equilibrium with the +res you put it off the mutual + + align:start position:0% +res you put it off the mutual + + + align:start position:0% +res you put it off the mutual +equilibrium by for example giving energy + + align:start position:0% +equilibrium by for example giving energy + + + align:start position:0% +equilibrium by for example giving energy +the system will + + align:start position:0% +the system will + + + align:start position:0% +the system will +react uh by increasing its temperature + + align:start position:0% +react uh by increasing its temperature + + + align:start position:0% +react uh by increasing its temperature +and the temperature as we know is the + + align:start position:0% +and the temperature as we know is the + + + align:start position:0% +and the temperature as we know is the +escaping tendency for energy so it + + align:start position:0% +escaping tendency for energy so it + + + align:start position:0% +escaping tendency for energy so it +increases its willingness to give away + + align:start position:0% +increases its willingness to give away + + + align:start position:0% +increases its willingness to give away +energy and since the reservoir is there + + align:start position:0% +energy and since the reservoir is there + + + align:start position:0% +energy and since the reservoir is there +uh it is It prepares uh the increasing + + align:start position:0% +uh it is It prepares uh the increasing + + + align:start position:0% +uh it is It prepares uh the increasing +in temperature + + align:start position:0% +in temperature + + + align:start position:0% +in temperature +prepares uh the for the for a heat + + align:start position:0% +prepares uh the for the for a heat + + + align:start position:0% +prepares uh the for the for a heat +interaction in which the system gives + + align:start position:0% +interaction in which the system gives + + + align:start position:0% +interaction in which the system gives +energy to the + + align:start position:0% +energy to the + + + align:start position:0% +energy to the +thereby + + align:start position:0% +thereby + + + align:start position:0% +thereby +contrasting the change with which you + + align:start position:0% +contrasting the change with which you + + + align:start position:0% +contrasting the change with which you +took it away from equilibrium it tries + + align:start position:0% +took it away from equilibrium it tries + + + align:start position:0% +took it away from equilibrium it tries +to spontaneously return to equilibrium + + align:start position:0% +to spontaneously return to equilibrium + + + align:start position:0% +to spontaneously return to equilibrium +by increasing its + + align:start position:0% + + + + align:start position:0% + +temperature so that's one thing all + + align:start position:0% +temperature so that's one thing all + + + align:start position:0% +temperature so that's one thing all +right so to to see a little + + align:start position:0% + + + + align:start position:0% + +more uh let's broaden our + + align:start position:0% +more uh let's broaden our + + + align:start position:0% +more uh let's broaden our +class or category of systems that we + + align:start position:0% +class or category of systems that we + + + align:start position:0% +class or category of systems that we +call thermal reservoirs or say heat + + align:start position:0% +call thermal reservoirs or say heat + + + align:start position:0% +call thermal reservoirs or say heat +Buffs because in practice we often have + + align:start position:0% +Buffs because in practice we often have + + + align:start position:0% +Buffs because in practice we often have +also uh + + align:start position:0% +also uh + + + align:start position:0% +also uh +reservoirs that are variable + + align:start position:0% + + + + align:start position:0% + +volume + + align:start position:0% +volume + + + align:start position:0% +volume +often the atmosphere where we live the + + align:start position:0% +often the atmosphere where we live the + + + align:start position:0% +often the atmosphere where we live the +Environ is the environment and it's + + align:start position:0% +Environ is the environment and it's + + + align:start position:0% +Environ is the environment and it's +something that would accept a change in + + align:start position:0% +something that would accept a change in + + + align:start position:0% +something that would accept a change in +volume uh + + align:start position:0% +volume uh + + + align:start position:0% +volume uh +uh + + align:start position:0% +uh + + + align:start position:0% +uh +without if you if if if the changeing + + align:start position:0% +without if you if if if the changeing + + + align:start position:0% +without if you if if if the changeing +volume is reasonably small and also the + + align:start position:0% +volume is reasonably small and also the + + + align:start position:0% +volume is reasonably small and also the +changes in + + align:start position:0% +changes in + + + align:start position:0% +changes in +energy are reasonably small uh you can + + align:start position:0% +energy are reasonably small uh you can + + + align:start position:0% +energy are reasonably small uh you can +add or subtract the volume and energy to + + align:start position:0% +add or subtract the volume and energy to + + + align:start position:0% +add or subtract the volume and energy to +the environment without changing its + + align:start position:0% +the environment without changing its + + + align:start position:0% +the environment without changing its +temperature and + + align:start position:0% +temperature and + + + align:start position:0% +temperature and +pressure so if the system is large + + align:start position:0% +pressure so if the system is large + + + align:start position:0% +pressure so if the system is large +enough like the air uh in the + + align:start position:0% +enough like the air uh in the + + + align:start position:0% +enough like the air uh in the +environment of of a town or the the the + + align:start position:0% +environment of of a town or the the the + + + align:start position:0% +environment of of a town or the the the +water in the sea or in the lake or in a + + align:start position:0% +water in the sea or in the lake or in a + + + align:start position:0% +water in the sea or in the lake or in a +river with respect to if it is if it is + + align:start position:0% +river with respect to if it is if it is + + + align:start position:0% +river with respect to if it is if it is +large enough with respect to the amounts + + align:start position:0% +large enough with respect to the amounts + + + align:start position:0% +large enough with respect to the amounts +of energies entropies and volume that + + align:start position:0% +of energies entropies and volume that + + + align:start position:0% +of energies entropies and volume that +you exchange then you may consider that + + align:start position:0% +you exchange then you may consider that + + + align:start position:0% +you exchange then you may consider that +as a as a thermal r word so A system + + align:start position:0% +as a as a thermal r word so A system + + + align:start position:0% +as a as a thermal r word so A system +that maintains + + align:start position:0% +that maintains + + + align:start position:0% +that maintains +fixed uh values of the temperature and + + align:start position:0% +fixed uh values of the temperature and + + + align:start position:0% +fixed uh values of the temperature and +the pressure in this case we + + align:start position:0% +the pressure in this case we + + + align:start position:0% +the pressure in this case we +consider system which has variable + + align:start position:0% +consider system which has variable + + + align:start position:0% +consider system which has variable +volume but still the amounts are + + align:start position:0% +volume but still the amounts are + + + align:start position:0% +volume but still the amounts are +fixed okay then the fundamental relation + + align:start position:0% +fixed okay then the fundamental relation + + + align:start position:0% +fixed okay then the fundamental relation +for a system is also um + + align:start position:0% +for a system is also um + + + align:start position:0% +for a system is also um +linear except that + + align:start position:0% +linear except that + + + align:start position:0% +linear except that +now okay before we had the uh energy + + align:start position:0% +now okay before we had the uh energy + + + align:start position:0% +now okay before we had the uh energy +entropy and this is the temperature + + align:start position:0% +entropy and this is the temperature + + + align:start position:0% +entropy and this is the temperature +TR now if we add volume as a possibility + + align:start position:0% +TR now if we add volume as a possibility + + + align:start position:0% +TR now if we add volume as a possibility +to change then okay let's see make to + + align:start position:0% + + + + align:start position:0% + +this + + align:start position:0% + + + + align:start position:0% + +then okay then we have an equation of + + align:start position:0% + + + + align:start position:0% + +uh of the plane + + align:start position:0% + + + + align:start position:0% + +of which the slopes are + + align:start position:0% +of which the slopes are + + + align:start position:0% +of which the slopes are +TR when you take the slope at constant V + + align:start position:0% +TR when you take the slope at constant V + + + align:start position:0% +TR when you take the slope at constant V +and minus P when you take the slope at + + align:start position:0% +and minus P when you take the slope at + + + align:start position:0% +and minus P when you take the slope at +constant uh + + align:start position:0% +constant uh + + + align:start position:0% +constant uh +s so this is equation of a of a plane + + align:start position:0% +s so this is equation of a of a plane + + + align:start position:0% +s so this is equation of a of a plane +and that's the fundamental relation for + + align:start position:0% +and that's the fundamental relation for + + + align:start position:0% +and that's the fundamental relation for +that thermal Reservoir at variable + + align:start position:0% + + + + align:start position:0% + +volume so we ask the same question now + + align:start position:0% +volume so we ask the same question now + + + align:start position:0% +volume so we ask the same question now +okay what + + align:start position:0% +okay what + + + align:start position:0% +okay what +if I'm changing state for my + + align:start position:0% +if I'm changing state for my + + + align:start position:0% +if I'm changing state for my +system but it exchanges volume what it + + align:start position:0% +system but it exchanges volume what it + + + align:start position:0% +system but it exchanges volume what it +exchanges volume with the + + align:start position:0% +exchanges volume with the + + + align:start position:0% +exchanges volume with the +reservoir so maybe the system changes s + + align:start position:0% +reservoir so maybe the system changes s + + + align:start position:0% +reservoir so maybe the system changes s +the + + align:start position:0% +the + + + align:start position:0% +the +volume and where does it take that + + align:start position:0% +volume and where does it take that + + + align:start position:0% +volume and where does it take that +volume from the + + align:start position:0% +volume from the + + + align:start position:0% +volume from the +reservoir or where does it give it to + + align:start position:0% +reservoir or where does it give it to + + + align:start position:0% +reservoir or where does it give it to +the + + align:start position:0% +the + + + align:start position:0% +the +reservoir you want to ask the maximum + + align:start position:0% +reservoir you want to ask the maximum + + + align:start position:0% +reservoir you want to ask the maximum +work or the minimum work requirement for + + align:start position:0% +work or the minimum work requirement for + + + align:start position:0% +work or the minimum work requirement for +doing that change well energy balance + + align:start position:0% +doing that change well energy balance + + + align:start position:0% +doing that change well energy balance +entropy balance fundamental relation for + + align:start position:0% +entropy balance fundamental relation for + + + align:start position:0% +entropy balance fundamental relation for +the reservoir and here you also have to + + align:start position:0% +the reservoir and here you also have to + + + align:start position:0% +the reservoir and here you also have to +do a volume balance because you have an + + align:start position:0% +do a volume balance because you have an + + + align:start position:0% +do a volume balance because you have an +additional variable that has to be kept + + align:start position:0% +additional variable that has to be kept + + + align:start position:0% +additional variable that has to be kept +uh fixed for the composite + + align:start position:0% +uh fixed for the composite + + + align:start position:0% +uh fixed for the composite +system the overall volume is + + align:start position:0% +system the overall volume is + + + align:start position:0% +system the overall volume is +concerned in order to have no other + + align:start position:0% +concerned in order to have no other + + + align:start position:0% +concerned in order to have no other +effect external + + align:start position:0% +effect external + + + align:start position:0% +effect external +effects like in a weight + + align:start position:0% +effects like in a weight + + + align:start position:0% +effects like in a weight +process okay + + align:start position:0% +process okay + + + align:start position:0% +process okay +so when you do the Sol when you solve + + align:start position:0% +so when you do the Sol when you solve + + + align:start position:0% +so when you do the Sol when you solve +this problem + + align:start position:0% +this problem + + + align:start position:0% +this problem +by eliminating the variables that um + + align:start position:0% +by eliminating the variables that um + + + align:start position:0% +by eliminating the variables that um +relate to the + + align:start position:0% +relate to the + + + align:start position:0% +relate to the +resir here's the + + align:start position:0% +resir here's the + + + align:start position:0% +resir here's the +result it's almost like before except + + align:start position:0% +result it's almost like before except + + + align:start position:0% +result it's almost like before except +that there is now an extra term here + + align:start position:0% +that there is now an extra term here + + + align:start position:0% +that there is now an extra term here +which is PR times the difference in + + align:start position:0% +which is PR times the difference in + + + align:start position:0% +which is PR times the difference in +volume of your system and again it's a + + align:start position:0% +volume of your system and again it's a + + + align:start position:0% +volume of your system and again it's a +reversible term minus + + align:start position:0% +reversible term minus + + + align:start position:0% +reversible term minus +a term related to + + align:start position:0% + + + + align:start position:0% + +irreversibility the reversible term can + + align:start position:0% +irreversibility the reversible term can + + + align:start position:0% +irreversibility the reversible term can +be seen as the difference in two + + align:start position:0% +be seen as the difference in two + + + align:start position:0% +be seen as the difference in two +um + + align:start position:0% +um + + + align:start position:0% +um +properties you could consider this as a + + align:start position:0% +properties you could consider this as a + + + align:start position:0% +properties you could consider this as a +definition of another property that we + + align:start position:0% +definition of another property that we + + + align:start position:0% +definition of another property that we +still call for short of names um + + align:start position:0% +still call for short of names um + + + align:start position:0% +still call for short of names um +available energy with respect to that + + align:start position:0% +available energy with respect to that + + + align:start position:0% +available energy with respect to that +particular Reservoir in that variable + + align:start position:0% +particular Reservoir in that variable + + + align:start position:0% +particular Reservoir in that variable +volume it's it's like the one + + align:start position:0% +volume it's it's like the one + + + align:start position:0% +volume it's it's like the one +before plus this additional P * Delta + + align:start position:0% +before plus this additional P * Delta + + + align:start position:0% +before plus this additional P * Delta +V and also this one if you as you notice + + align:start position:0% +V and also this one if you as you notice + + + align:start position:0% +V and also this one if you as you notice +may be written as a + + align:start position:0% +may be written as a + + + align:start position:0% +may be written as a +difference in an availability function e + + align:start position:0% +difference in an availability function e + + + align:start position:0% +difference in an availability function e +minus TRS plus P + + align:start position:0% +minus TRS plus P + + + align:start position:0% +minus TRS plus P +RV which we're going to call uh just + + align:start position:0% +RV which we're going to call uh just + + + align:start position:0% +RV which we're going to call uh just +with the name capital c + + align:start position:0% + + + + align:start position:0% + +and we may notice + + align:start position:0% +and we may notice + + + align:start position:0% +and we may notice +that this is + + align:start position:0% +that this is + + + align:start position:0% +that this is +not it looks like but it's not the GS + + align:start position:0% +not it looks like but it's not the GS + + + align:start position:0% +not it looks like but it's not the GS +free + + align:start position:0% +free + + + align:start position:0% +free +energy except when the system is in + + align:start position:0% +energy except when the system is in + + + align:start position:0% +energy except when the system is in +mutual equilibrium in the state of + + align:start position:0% +mutual equilibrium in the state of + + + align:start position:0% +mutual equilibrium in the state of +mutual equilibrium with the + + align:start position:0% +mutual equilibrium with the + + + align:start position:0% +mutual equilibrium with the +environment in that case TR is also the + + align:start position:0% +environment in that case TR is also the + + + align:start position:0% +environment in that case TR is also the +temperature of your system a and + + align:start position:0% +temperature of your system a and + + + align:start position:0% +temperature of your system a and +therefore this is the Gibs free energy + + align:start position:0% + + + + align:start position:0% + +whereas uh in any other + + align:start position:0% +whereas uh in any other + + + align:start position:0% +whereas uh in any other +state this TR this PR may not + + align:start position:0% +state this TR this PR may not + + + align:start position:0% +state this TR this PR may not +be the uh temperature of your system + + align:start position:0% +be the uh temperature of your system + + + align:start position:0% +be the uh temperature of your system +a and actually if the state is not an + + align:start position:0% +a and actually if the state is not an + + + align:start position:0% +a and actually if the state is not an +equilibrium State the temp the system a + + align:start position:0% +equilibrium State the temp the system a + + + align:start position:0% +equilibrium State the temp the system a +might not even have a temperature + + align:start position:0% +might not even have a temperature + + + align:start position:0% +might not even have a temperature +defined actually it does not if it is + + align:start position:0% +defined actually it does not if it is + + + align:start position:0% +defined actually it does not if it is +not stable equilibrium yet this + + align:start position:0% +not stable equilibrium yet this + + + align:start position:0% +not stable equilibrium yet this +availability function is + + align:start position:0% +availability function is + + + align:start position:0% +availability function is +defined and it gives + + align:start position:0% +defined and it gives + + + align:start position:0% +defined and it gives +you these answers to questions of + + align:start position:0% +you these answers to questions of + + + align:start position:0% +you these answers to questions of +minimum or maximum uh work to do or to + + align:start position:0% +minimum or maximum uh work to do or to + + + align:start position:0% +minimum or maximum uh work to do or to +uh to + + align:start position:0% + + + + align:start position:0% + +obtain yes exactly with the same + + align:start position:0% +obtain yes exactly with the same + + + align:start position:0% +obtain yes exactly with the same +procedure that we have done to + + align:start position:0% +procedure that we have done to + + + align:start position:0% +procedure that we have done to +obtain + + align:start position:0% +obtain + + + align:start position:0% +obtain +these conditions for the + + align:start position:0% +these conditions for the + + + align:start position:0% +these conditions for the +stability you can do it also here now I + + align:start position:0% +stability you can do it also here now I + + + align:start position:0% +stability you can do it also here now I +since I have several variables it's not + + align:start position:0% +since I have several variables it's not + + + align:start position:0% +since I have several variables it's not +uh I'm sorry let me go back one moment + + align:start position:0% +uh I'm sorry let me go back one moment + + + align:start position:0% +uh I'm sorry let me go back one moment +here + + align:start position:0% +here + + + align:start position:0% +here +okay so you you should think of a + + align:start position:0% +okay so you you should think of a + + + align:start position:0% +okay so you you should think of a +similar procedure only in a + + align:start position:0% +similar procedure only in a + + + align:start position:0% +similar procedure only in a +three-dimensional setup in which you + + align:start position:0% +three-dimensional setup in which you + + + align:start position:0% +three-dimensional setup in which you +start from a mutual equilibrium state + + align:start position:0% +start from a mutual equilibrium state + + + align:start position:0% +start from a mutual equilibrium state +and you + + align:start position:0% +and you + + + align:start position:0% +and you +move away from it and then you apply the + + align:start position:0% +move away from it and then you apply the + + + align:start position:0% +move away from it and then you apply the +condition that gamma must + + align:start position:0% +condition that gamma must + + + align:start position:0% +condition that gamma must +increase if you move away now whereas + + align:start position:0% +increase if you move away now whereas + + + align:start position:0% +increase if you move away now whereas +here you could move + + align:start position:0% +here you could move + + + align:start position:0% +here you could move +away only on the e s + + align:start position:0% + + + + align:start position:0% + +plane in the new uh setup where also the + + align:start position:0% +plane in the new uh setup where also the + + + align:start position:0% +plane in the new uh setup where also the +Val volume is CH is uh is is is can be + + align:start position:0% +Val volume is CH is uh is is is can be + + + align:start position:0% +Val volume is CH is uh is is is can be +changed yes you can move + + align:start position:0% +changed yes you can move + + + align:start position:0% +changed yes you can move +at constant uh V or constant e or but + + align:start position:0% +at constant uh V or constant e or but + + + align:start position:0% +at constant uh V or constant e or but +you can also move in any other direction + + align:start position:0% +you can also move in any other direction + + + align:start position:0% +you can also move in any other direction +so you have more + + align:start position:0% +so you have more + + + align:start position:0% +so you have more +choices and whatever choice you make you + + align:start position:0% +choices and whatever choice you make you + + + align:start position:0% +choices and whatever choice you make you +still have to have this property to + + align:start position:0% +still have to have this property to + + + align:start position:0% +still have to have this property to +uh uh + + align:start position:0% + + + + align:start position:0% + +increase so here I let you if you're + + align:start position:0% +increase so here I let you if you're + + + align:start position:0% +increase so here I let you if you're +interested watch the + + align:start position:0% +interested watch the + + + align:start position:0% +interested watch the +details I choose a a uh for example to + + align:start position:0% +details I choose a a uh for example to + + + align:start position:0% +details I choose a a uh for example to +move by changing the entropy and the + + align:start position:0% +move by changing the entropy and the + + + align:start position:0% +move by changing the entropy and the +volume keeping keeping the N fixed and + + align:start position:0% +volume keeping keeping the N fixed and + + + align:start position:0% +volume keeping keeping the N fixed and +it turns out that when you compute the + + align:start position:0% +it turns out that when you compute the + + + align:start position:0% +it turns out that when you compute the +change in the variable Fe it is exactly + + align:start position:0% +change in the variable Fe it is exactly + + + align:start position:0% +change in the variable Fe it is exactly +equal to a half the second differential + + align:start position:0% +equal to a half the second differential + + + align:start position:0% +equal to a half the second differential +of + + align:start position:0% +of + + + align:start position:0% +of +e uh and therefore you prove that this + + align:start position:0% +e uh and therefore you prove that this + + + align:start position:0% +e uh and therefore you prove that this +is greater than equal to + + align:start position:0% +is greater than equal to + + + align:start position:0% +is greater than equal to +zero or if I choose instead to change + + align:start position:0% +zero or if I choose instead to change + + + align:start position:0% +zero or if I choose instead to change +the energy and volume and therefore and + + align:start position:0% +the energy and volume and therefore and + + + align:start position:0% +the energy and volume and therefore and +to move along the stable equilibrium + + align:start position:0% +to move along the stable equilibrium + + + align:start position:0% +to move along the stable equilibrium +State curve so that the entropy is + + align:start position:0% +State curve so that the entropy is + + + align:start position:0% +State curve so that the entropy is +determined by the fundamental relation + + align:start position:0% +determined by the fundamental relation + + + align:start position:0% +determined by the fundamental relation +then Delta V becomes equal to minus the + + align:start position:0% +then Delta V becomes equal to minus the + + + align:start position:0% +then Delta V becomes equal to minus the +second differential of the + + align:start position:0% +second differential of the + + + align:start position:0% +second differential of the +entropy and since that must be greater + + align:start position:0% +entropy and since that must be greater + + + align:start position:0% +entropy and since that must be greater +than zero it it gives again that + + align:start position:0% +than zero it it gives again that + + + align:start position:0% +than zero it it gives again that +d2s is at fixed n now this + + align:start position:0% +d2s is at fixed n now this + + + align:start position:0% +d2s is at fixed n now this +d2s now + + align:start position:0% +d2s now + + + align:start position:0% +d2s now +if you want to represent + + align:start position:0% +if you want to represent + + + align:start position:0% +if you want to represent +it it's not just the second + + align:start position:0% +it it's not just the second + + + align:start position:0% +it it's not just the second +derivative + + align:start position:0% +derivative + + + align:start position:0% +derivative +uh because you + + align:start position:0% +uh because you + + + align:start position:0% +uh because you +see when we have D d2s at constant V and + + align:start position:0% +see when we have D d2s at constant V and + + + align:start position:0% +see when we have D d2s at constant V and +N this was equal to the second + + align:start position:0% +N this was equal to the second + + + align:start position:0% +N this was equal to the second +derivative of s with respect to + + align:start position:0% +derivative of s with respect to + + + align:start position:0% +derivative of s with respect to +e times the e s + + align:start position:0% + + + + align:start position:0% + +but this other + + align:start position:0% +but this other + + + align:start position:0% +but this other +d2s at constant n only you can vary both + + align:start position:0% +d2s at constant n only you can vary both + + + align:start position:0% +d2s at constant n only you can vary both +e and s + + align:start position:0% +e and s + + + align:start position:0% +e and s +then uh it's given by d2s with respect + + align:start position:0% +then uh it's given by d2s with respect + + + align:start position:0% +then uh it's given by d2s with respect +to + + align:start position:0% +to + + + align:start position:0% +to +e^2 time e + + align:start position:0% +e^2 time e + + + align:start position:0% +e^2 time e +squar plus twice the second derivative + + align:start position:0% +squar plus twice the second derivative + + + align:start position:0% +squar plus twice the second derivative +of s with respect to e and with respect + + align:start position:0% +of s with respect to e and with respect + + + align:start position:0% +of s with respect to e and with respect +to V times d e + + align:start position:0% +to V times d e + + + align:start position:0% +to V times d e +DV plus the second with respect to + + align:start position:0% +DV plus the second with respect to + + + align:start position:0% +DV plus the second with respect to +V twice times DV squ so it's a quadratic + + align:start position:0% +V twice times DV squ so it's a quadratic + + + align:start position:0% +V twice times DV squ so it's a quadratic +form which you can express also in terms + + align:start position:0% +form which you can express also in terms + + + align:start position:0% +form which you can express also in terms +of the uh in in in this form uh like + + align:start position:0% +of the uh in in in this form uh like + + + align:start position:0% +of the uh in in in this form uh like +using matrices D + + align:start position:0% +using matrices D + + + align:start position:0% +using matrices D +DV here you put the S determinant which + + align:start position:0% +DV here you put the S determinant which + + + align:start position:0% +DV here you put the S determinant which +is the determinant made up of the second + + align:start position:0% + + + + align:start position:0% + +derivatives okay and this is + + align:start position:0% +derivatives okay and this is + + + align:start position:0% +derivatives okay and this is +equal and then you multiply this by this + + align:start position:0% +equal and then you multiply this by this + + + align:start position:0% +equal and then you multiply this by this +other Vector made up of two + + align:start position:0% +other Vector made up of two + + + align:start position:0% +other Vector made up of two +elements D and DV if you do matrix + + align:start position:0% +elements D and DV if you do matrix + + + align:start position:0% +elements D and DV if you do matrix +multiplication of of this let's be more + + align:start position:0% +multiplication of of this let's be more + + + align:start position:0% +multiplication of of this let's be more +uh elegant here uh you get the above + + align:start position:0% +uh elegant here uh you get the above + + + align:start position:0% +uh elegant here uh you get the above +result + + align:start position:0% + + + + align:start position:0% + +okay and the fact that this has to be + + align:start position:0% +okay and the fact that this has to be + + + align:start position:0% +okay and the fact that this has to be +negative for arbitrary so this has to + + align:start position:0% +negative for arbitrary so this has to + + + align:start position:0% +negative for arbitrary so this has to +be uh negative for arbitrary choice of + + align:start position:0% +be uh negative for arbitrary choice of + + + align:start position:0% +be uh negative for arbitrary choice of +your vector D DV which + + align:start position:0% +your vector D DV which + + + align:start position:0% +your vector D DV which +means no matter what direction you want + + align:start position:0% +means no matter what direction you want + + + align:start position:0% +means no matter what direction you want +to move uh uh + + align:start position:0% +to move uh uh + + + align:start position:0% +to move uh uh +this has to be + + align:start position:0% +this has to be + + + align:start position:0% +this has to be +negative that requires that the Matrix + + align:start position:0% +negative that requires that the Matrix + + + align:start position:0% +negative that requires that the Matrix +inside be no negative + + align:start position:0% + + + + align:start position:0% + +definite and the Matrix is non negative + + align:start position:0% + + + + align:start position:0% + +definite + + align:start position:0% +definite + + + align:start position:0% +definite +when I me I mean sorry sorry non + + align:start position:0% +when I me I mean sorry sorry non + + + align:start position:0% +when I me I mean sorry sorry non +positive non so it's it's negative + + align:start position:0% +positive non so it's it's negative + + + align:start position:0% +positive non so it's it's negative +semide definite okay so when is a matrix + + align:start position:0% + + + + align:start position:0% + +uh let's start with positive when is a + + align:start position:0% +uh let's start with positive when is a + + + align:start position:0% +uh let's start with positive when is a +matrix positive + + align:start position:0% + + + + align:start position:0% + +definite I have a matrix a 1 one + + align:start position:0% + + + + align:start position:0% + +a12 and let's make it symmetric + + align:start position:0% + + + + align:start position:0% + +okay so + + align:start position:0% + + + + align:start position:0% + +this if it is positive semide + + align:start position:0% + + + + align:start position:0% + +definite the diagonal entries must be + + align:start position:0% +definite the diagonal entries must be + + + align:start position:0% +definite the diagonal entries must be +non- + + align:start position:0% + + + + align:start position:0% + +negative the + + align:start position:0% +negative the + + + align:start position:0% +negative the +determinant must be non- negative so a 1 + + align:start position:0% +determinant must be non- negative so a 1 + + + align:start position:0% +determinant must be non- negative so a 1 +1 a22 minus + + align:start position:0% +1 a22 minus + + + align:start position:0% +1 a22 minus +a12 squared because it's a + + align:start position:0% +a12 squared because it's a + + + align:start position:0% +a12 squared because it's a +symmetric must be greater than equal to + + align:start position:0% + + + + align:start position:0% + +zero you want to make it uh uh if the + + align:start position:0% +zero you want to make it uh uh if the + + + align:start position:0% +zero you want to make it uh uh if the +Matrix instead of + + align:start position:0% +Matrix instead of + + + align:start position:0% +Matrix instead of +being positive semi-definite is negative + + align:start position:0% +being positive semi-definite is negative + + + align:start position:0% +being positive semi-definite is negative +semi-definite so this is less than or + + align:start position:0% +semi-definite so this is less than or + + + align:start position:0% +semi-definite so this is less than or +equal to + + align:start position:0% + + + + align:start position:0% + +so the + + align:start position:0% +so the + + + align:start position:0% +so the +entries on the diagonal should + + align:start position:0% +entries on the diagonal should + + + align:start position:0% +entries on the diagonal should +be non NE non + + align:start position:0% + + + + align:start position:0% + +positive how about the + + align:start position:0% +positive how about the + + + align:start position:0% +positive how about the +determinant should I change the + + align:start position:0% + + + + align:start position:0% + +sign not for a 2X two + + align:start position:0% +sign not for a 2X two + + + align:start position:0% +sign not for a 2X two +Matrix because you see also + + align:start position:0% + + + + align:start position:0% + +the more uh fundamental way uh property + + align:start position:0% +the more uh fundamental way uh property + + + align:start position:0% +the more uh fundamental way uh property +of of a non negative uh of a a nonos + + align:start position:0% +of of a non negative uh of a a nonos + + + align:start position:0% +of of a non negative uh of a a nonos +of of a negative semide definite Matrix + + align:start position:0% +of of a negative semide definite Matrix + + + align:start position:0% +of of a negative semide definite Matrix +is that it's igen values are + + align:start position:0% +is that it's igen values are + + + align:start position:0% +is that it's igen values are +all + + align:start position:0% +all + + + align:start position:0% +all +negative so it means let's say let's + + align:start position:0% +negative so it means let's say let's + + + align:start position:0% +negative so it means let's say let's +call them Lambda so Lambda 1 is less + + align:start position:0% +call them Lambda so Lambda 1 is less + + + align:start position:0% +call them Lambda so Lambda 1 is less +than zero Lambda 2 is less than zero + + align:start position:0% + + + + align:start position:0% + +and for a 2x2 matrix the + + align:start position:0% +and for a 2x2 matrix the + + + align:start position:0% +and for a 2x2 matrix the +determinant is equal to the product of + + align:start position:0% +determinant is equal to the product of + + + align:start position:0% +determinant is equal to the product of +the two L values so this is also equal + + align:start position:0% +the two L values so this is also equal + + + align:start position:0% +the two L values so this is also equal +to Lambda 1 time Lambda 2 so if you + + align:start position:0% +to Lambda 1 time Lambda 2 so if you + + + align:start position:0% +to Lambda 1 time Lambda 2 so if you +multiply two negative numbers you get a + + align:start position:0% +multiply two negative numbers you get a + + + align:start position:0% +multiply two negative numbers you get a +positive number and so you + + align:start position:0% +positive number and so you + + + align:start position:0% +positive number and so you +get the determinant is greater than zero + + align:start position:0% +get the determinant is greater than zero + + + align:start position:0% +get the determinant is greater than zero +If instead you you add a 3 by 3x3 Matrix + + align:start position:0% +If instead you you add a 3 by 3x3 Matrix + + + align:start position:0% +If instead you you add a 3 by 3x3 Matrix +then you have three negative numbers + + align:start position:0% +then you have three negative numbers + + + align:start position:0% +then you have three negative numbers +that multiplied give the determinant in + + align:start position:0% +that multiplied give the determinant in + + + align:start position:0% +that multiplied give the determinant in +that + + align:start position:0% +that + + + align:start position:0% +that +case with an odd number of uh entries uh + + align:start position:0% +case with an odd number of uh entries uh + + + align:start position:0% +case with an odd number of uh entries uh +negative time negative time negative + + align:start position:0% +negative time negative time negative + + + align:start position:0% +negative time negative time negative +makes Nega right so the determinant of + + align:start position:0% +makes Nega right so the determinant of + + + align:start position:0% +makes Nega right so the determinant of +of of the uh + + align:start position:0% +of of the uh + + + align:start position:0% +of of the uh +semi uh of a negative semide definite + + align:start position:0% +semi uh of a negative semide definite + + + align:start position:0% +semi uh of a negative semide definite +Matrix is positive for odd number of uh + + align:start position:0% +Matrix is positive for odd number of uh + + + align:start position:0% +Matrix is positive for odd number of uh +rows and columns and uh negative for uh + + align:start position:0% +rows and columns and uh negative for uh + + + align:start position:0% +rows and columns and uh negative for uh +what did it say positive for even number + + align:start position:0% +what did it say positive for even number + + + align:start position:0% +what did it say positive for even number +and negative for odd + + align:start position:0% +and negative for odd + + + align:start position:0% +and negative for odd +number + + align:start position:0% + + + + align:start position:0% + +okay we need that in a short + + align:start position:0% + + + + align:start position:0% + +while here oh yeah let me just uh + + align:start position:0% +while here oh yeah let me just uh + + + align:start position:0% +while here oh yeah let me just uh +go back to like + + align:start position:0% +go back to like + + + align:start position:0% +go back to like +a a simple + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% + + + + align:start position:0% + +question + + align:start position:0% + + + + align:start position:0% + +about all right suppose you + + align:start position:0% + + + + align:start position:0% + +have you have vacuum so you have a + + align:start position:0% +have you have vacuum so you have a + + + align:start position:0% +have you have vacuum so you have a +piston you have a a + + align:start position:0% +piston you have a a + + + align:start position:0% +piston you have a a +container in which you manage to have + + align:start position:0% +container in which you manage to have + + + align:start position:0% +container in which you manage to have +nothing vacuum vacuum means no particles + + align:start position:0% +nothing vacuum vacuum means no particles + + + align:start position:0% +nothing vacuum vacuum means no particles +nothing + + align:start position:0% +nothing + + + align:start position:0% +nothing +okay so the question + + align:start position:0% + + + + align:start position:0% + +is is that a + + align:start position:0% +is is that a + + + align:start position:0% +is is that a +situation and this vacuum is in a uh in + + align:start position:0% +situation and this vacuum is in a uh in + + + align:start position:0% +situation and this vacuum is in a uh in +an environment which I can + + align:start position:0% +an environment which I can + + + align:start position:0% +an environment which I can +model as a reservoir + + align:start position:0% +model as a reservoir + + + align:start position:0% +model as a reservoir +at pressure + + align:start position:0% +at pressure + + + align:start position:0% +at pressure +PR yeah also temperature TR but uh the + + align:start position:0% +PR yeah also temperature TR but uh the + + + align:start position:0% +PR yeah also temperature TR but uh the +temperature doesn't play much over Ro + + align:start position:0% +temperature doesn't play much over Ro + + + align:start position:0% +temperature doesn't play much over Ro +here so it's like I have this container + + align:start position:0% +here so it's like I have this container + + + align:start position:0% +here so it's like I have this container +in the environment here man I manage to + + align:start position:0% +in the environment here man I manage to + + + align:start position:0% +in the environment here man I manage to +make + + align:start position:0% +make + + + align:start position:0% +make +vacuum what's the minimum work required + + align:start position:0% +vacuum what's the minimum work required + + + align:start position:0% +vacuum what's the minimum work required +to make that + + align:start position:0% +to make that + + + align:start position:0% +to make that +vacuum or if I have that vacuum can I do + + align:start position:0% +vacuum or if I have that vacuum can I do + + + align:start position:0% +vacuum or if I have that vacuum can I do +something useful can I lift the weight + + align:start position:0% +something useful can I lift the weight + + + align:start position:0% +something useful can I lift the weight +what's the maximum uh + + align:start position:0% + + + + align:start position:0% + +lift well let's + + align:start position:0% +lift well let's + + + align:start position:0% +lift well let's +apply this formula + + align:start position:0% + + + + align:start position:0% + +here assume that we do things the best + + align:start position:0% +here assume that we do things the best + + + align:start position:0% +here assume that we do things the best +thermodynamic way so that means without + + align:start position:0% +thermodynamic way so that means without + + + align:start position:0% +thermodynamic way so that means without +generating entropy by + + align:start position:0% + + + + align:start position:0% + +irreversibility and suppose I want my + + align:start position:0% +irreversibility and suppose I want my + + + align:start position:0% +irreversibility and suppose I want my +initial state state one + + align:start position:0% +initial state state one + + + align:start position:0% +initial state state one +okay so let me say that I started with + + align:start position:0% +okay so let me say that I started with + + + align:start position:0% +okay so let me say that I started with +my piston down below + + align:start position:0% +my piston down below + + + align:start position:0% +my piston down below +here and now so this is my say State one + + align:start position:0% +here and now so this is my say State one + + + align:start position:0% +here and now so this is my say State one +and this is my state + + align:start position:0% +and this is my state + + + align:start position:0% +and this is my state +two and I + + align:start position:0% + + + + align:start position:0% + +pull here I have the + + align:start position:0% +pull here I have the + + + align:start position:0% +pull here I have the +pressure of the + + align:start position:0% +pressure of the + + + align:start position:0% +pressure of the +environment so if I pull + + align:start position:0% + + + + align:start position:0% + +how much work do I have to do I have to + + align:start position:0% +how much work do I have to do I have to + + + align:start position:0% +how much work do I have to do I have to +the if you look at the piston on one + + align:start position:0% +the if you look at the piston on one + + + align:start position:0% +the if you look at the piston on one +side you have zero pressure because + + align:start position:0% +side you have zero pressure because + + + align:start position:0% +side you have zero pressure because +nothing here on the other side you have + + align:start position:0% + + + + align:start position:0% + +PR so if you if the the + + align:start position:0% +PR so if you if the the + + + align:start position:0% +PR so if you if the the +volume change is vs2 minus + + align:start position:0% + + + + align:start position:0% + +V1 you can view that as + + align:start position:0% +V1 you can view that as + + + align:start position:0% +V1 you can view that as +a that's let's call X this + + align:start position:0% +a that's let's call X this + + + align:start position:0% +a that's let's call X this +uh the loc let's call Z the location of + + align:start position:0% +uh the loc let's call Z the location of + + + align:start position:0% +uh the loc let's call Z the location of +the of the weight I'm sorry of the + + align:start position:0% +the of the weight I'm sorry of the + + + align:start position:0% +the of the weight I'm sorry of the +piston and let's call Little a the area + + align:start position:0% +piston and let's call Little a the area + + + align:start position:0% +piston and let's call Little a the area +of the + + align:start position:0% + + + + align:start position:0% + +Piston + + align:start position:0% +Piston + + + align:start position:0% +Piston +so the + + align:start position:0% +so the + + + align:start position:0% +so the +force that you have to apply is equal + + align:start position:0% +force that you have to apply is equal + + + align:start position:0% +force that you have to apply is equal +to the pressure times which is force per + + align:start position:0% +to the pressure times which is force per + + + align:start position:0% +to the pressure times which is force per +unit area times the area so that's the + + align:start position:0% +unit area times the area so that's the + + + align:start position:0% +unit area times the area so that's the +force the + + align:start position:0% +force the + + + align:start position:0% +force the +work is + + align:start position:0% +work is + + + align:start position:0% +work is +f time + + align:start position:0% +f time + + + align:start position:0% +f time +x Force I'm sorry + + align:start position:0% + + + + align:start position:0% + +Z + + align:start position:0% +Z + + + align:start position:0% +Z +right uh so that's p + + align:start position:0% +right uh so that's p + + + align:start position:0% +right uh so that's p +r time a + + align:start position:0% +r time a + + + align:start position:0% +r time a +z but a z is the volume so that's p r * + + align:start position:0% +z but a z is the volume so that's p r * + + + align:start position:0% +z but a z is the volume so that's p r * +V but actually it's V2 minus V1 because + + align:start position:0% +V but actually it's V2 minus V1 because + + + align:start position:0% +V but actually it's V2 minus V1 because +uh this is V2 and this is V1 is equal to + + align:start position:0% +uh this is V2 and this is V1 is equal to + + + align:start position:0% +uh this is V2 and this is V1 is equal to +zero in in our case + + align:start position:0% + + + + align:start position:0% + +so it seems that the + + align:start position:0% + + + + align:start position:0% + +work that you need to spend B in order + + align:start position:0% +work that you need to spend B in order + + + align:start position:0% +work that you need to spend B in order +to go from one to two in a reversible + + align:start position:0% +to go from one to two in a reversible + + + align:start position:0% +to go from one to two in a reversible +way is equal to + + align:start position:0% +way is equal to + + + align:start position:0% +way is equal to +that which is written + + align:start position:0% +that which is written + + + align:start position:0% +that which is written +here except that + + align:start position:0% + + + + align:start position:0% + +now it has the wrong + + align:start position:0% +now it has the wrong + + + align:start position:0% +now it has the wrong +sign because this represents the work + + align:start position:0% +sign because this represents the work + + + align:start position:0% +sign because this represents the work +with the arrow out + + align:start position:0% +with the arrow out + + + align:start position:0% +with the arrow out +instead we are spend if we change the + + align:start position:0% +instead we are spend if we change the + + + align:start position:0% +instead we are spend if we change the +direction of the the arrow so me say + + align:start position:0% +direction of the the arrow so me say + + + align:start position:0% +direction of the the arrow so me say +that this is the work that I need to + + align:start position:0% +that this is the work that I need to + + + align:start position:0% +that this is the work that I need to +spend + + align:start position:0% + + + + align:start position:0% + +okay and of course this I could also + + align:start position:0% +okay and of course this I could also + + + align:start position:0% +okay and of course this I could also +write at the same + + align:start position:0% + + + + align:start position:0% + +thing by changing the arrow if I change + + align:start position:0% +thing by changing the arrow if I change + + + align:start position:0% +thing by changing the arrow if I change +the arrow I change also the + + align:start position:0% + + + + align:start position:0% + +sign + + align:start position:0% +sign + + + align:start position:0% +sign +okay so essentially the the the the + + align:start position:0% +okay so essentially the the the the + + + align:start position:0% +okay so essentially the the the the +minimum work to required to produce the + + align:start position:0% +minimum work to required to produce the + + + align:start position:0% +minimum work to required to produce the +vacuum is equal to the pressure of the + + align:start position:0% +vacuum is equal to the pressure of the + + + align:start position:0% +vacuum is equal to the pressure of the +environment times the volume of that + + align:start position:0% +environment times the volume of that + + + align:start position:0% +environment times the volume of that +vacuum that's an easy result we could + + align:start position:0% +vacuum that's an easy result we could + + + align:start position:0% +vacuum that's an easy result we could +have I mean we actually got to that + + align:start position:0% +have I mean we actually got to that + + + align:start position:0% +have I mean we actually got to that +result without all the complicated uh + + align:start position:0% +result without all the complicated uh + + + align:start position:0% +result without all the complicated uh +long story that we are telling + + align:start position:0% +long story that we are telling + + + align:start position:0% +long story that we are telling +but that's just + + align:start position:0% +but that's just + + + align:start position:0% +but that's just +to uh show what uh the consistency of + + align:start position:0% +to uh show what uh the consistency of + + + align:start position:0% +to uh show what uh the consistency of +this relation we what we what we know + + align:start position:0% + + + + align:start position:0% + +so now let's think of another kind of uh + + align:start position:0% + + + + align:start position:0% + +Reservoir which again can be uh + + align:start position:0% +Reservoir which again can be uh + + + align:start position:0% +Reservoir which again can be uh +typically is a typical model of the a + + align:start position:0% +typically is a typical model of the a + + + align:start position:0% +typically is a typical model of the a +environment or the or or some natural uh + + align:start position:0% + + + + align:start position:0% + +environment so here is a particular + + align:start position:0% +environment so here is a particular + + + align:start position:0% +environment so here is a particular +Reservoir that can exchange through a + + align:start position:0% +Reservoir that can exchange through a + + + align:start position:0% +Reservoir that can exchange through a +semi perable membrane only one type of + + align:start position:0% +semi perable membrane only one type of + + + align:start position:0% +semi perable membrane only one type of +substance with your + + align:start position:0% +substance with your + + + align:start position:0% +substance with your +system we may we may call it the an + + align:start position:0% +system we may we may call it the an + + + align:start position:0% +system we may we may call it the an +osmotic Reservoir or a thermal Reservoir + + align:start position:0% +osmotic Reservoir or a thermal Reservoir + + + align:start position:0% +osmotic Reservoir or a thermal Reservoir +or we just not don't give any + + align:start position:0% + + + + align:start position:0% + +names but just Define it uh uh by just + + align:start position:0% +names but just Define it uh uh by just + + + align:start position:0% +names but just Define it uh uh by just +these words all + + align:start position:0% +these words all + + + align:start position:0% +these words all +right you run the same machine machery + + align:start position:0% +right you run the same machine machery + + + align:start position:0% +right you run the same machine machery +energy balance entropy balance now you + + align:start position:0% +energy balance entropy balance now you + + + align:start position:0% +energy balance entropy balance now you +also have to make a balance for the + + align:start position:0% +also have to make a balance for the + + + align:start position:0% +also have to make a balance for the +amounts of constituents of the kind of + + align:start position:0% +amounts of constituents of the kind of + + + align:start position:0% +amounts of constituents of the kind of +substance that can be uh + + align:start position:0% + + + + align:start position:0% + +transferred for example you + + align:start position:0% +transferred for example you + + + align:start position:0% +transferred for example you +can you may be + + align:start position:0% +can you may be + + + align:start position:0% +can you may be +interested in U you know some people are + + align:start position:0% +interested in U you know some people are + + + align:start position:0% +interested in U you know some people are +devising uh devising um methods or or U + + align:start position:0% +devising uh devising um methods or or U + + + align:start position:0% +devising uh devising um methods or or U +uh plants that want to extract CO2 from + + align:start position:0% +uh plants that want to extract CO2 from + + + align:start position:0% +uh plants that want to extract CO2 from +the + + align:start position:0% +the + + + align:start position:0% +the +atmosphere right so you want to ask well + + align:start position:0% +atmosphere right so you want to ask well + + + align:start position:0% +atmosphere right so you want to ask well +what's the minimum amount of work I need + + align:start position:0% +what's the minimum amount of work I need + + + align:start position:0% +what's the minimum amount of work I need +to spend if I want to uh extract CO2 + + align:start position:0% +to spend if I want to uh extract CO2 + + + align:start position:0% +to spend if I want to uh extract CO2 +from the + + align:start position:0% +from the + + + align:start position:0% +from the +atmosphere because that minimum defines + + align:start position:0% +atmosphere because that minimum defines + + + align:start position:0% +atmosphere because that minimum defines +the + + align:start position:0% +the + + + align:start position:0% +the +target defines also the way in which you + + align:start position:0% +target defines also the way in which you + + + align:start position:0% +target defines also the way in which you +determine the efficiency the second low + + align:start position:0% +determine the efficiency the second low + + + align:start position:0% +determine the efficiency the second low +efficiency of that uh particular uh + + align:start position:0% + + + + align:start position:0% + +equipment and it's a question very + + align:start position:0% +equipment and it's a question very + + + align:start position:0% +equipment and it's a question very +similar to this one because one + + align:start position:0% +similar to this one because one + + + align:start position:0% +similar to this one because one +way one way to do + + align:start position:0% +way one way to do + + + align:start position:0% +way one way to do +that uh not saying it's the reversible + + align:start position:0% +that uh not saying it's the reversible + + + align:start position:0% +that uh not saying it's the reversible +way but I'm saying that one way to do it + + align:start position:0% +way but I'm saying that one way to do it + + + align:start position:0% +way but I'm saying that one way to do it +is first you do + + align:start position:0% + + + + align:start position:0% + +vacuum and + + align:start position:0% +vacuum and + + + align:start position:0% +vacuum and +then you open + + align:start position:0% +then you open + + + align:start position:0% +then you open +up the permeability of the Piston to C + + align:start position:0% +up the permeability of the Piston to C + + + align:start position:0% +up the permeability of the Piston to C +just + + align:start position:0% +just + + + align:start position:0% +just +CO2 and so CO2 will fill this + + align:start position:0% +CO2 and so CO2 will fill this + + + align:start position:0% +CO2 and so CO2 will fill this +region and you'll have just CO2 because + + align:start position:0% +region and you'll have just CO2 because + + + align:start position:0% +region and you'll have just CO2 because +the other parts the other mean O oxygen + + align:start position:0% +the other parts the other mean O oxygen + + + align:start position:0% +the other parts the other mean O oxygen +and nitrogen cannot go through uh this + + align:start position:0% +and nitrogen cannot go through uh this + + + align:start position:0% +and nitrogen cannot go through uh this +particular semi-permeable membrane and + + align:start position:0% +particular semi-permeable membrane and + + + align:start position:0% +particular semi-permeable membrane and +that way you have + + align:start position:0% +that way you have + + + align:start position:0% +that way you have +separated so one way is produce vacuum + + align:start position:0% +separated so one way is produce vacuum + + + align:start position:0% +separated so one way is produce vacuum +and we know how much it work it requires + + align:start position:0% + + + + align:start position:0% + +use a semi-perm membrane and there you + + align:start position:0% +use a semi-perm membrane and there you + + + align:start position:0% +use a semi-perm membrane and there you +have your your uh CO2 your CO2 + + align:start position:0% +have your your uh CO2 your CO2 + + + align:start position:0% +have your your uh CO2 your CO2 +eventually will reach Mutual equilibrium + + align:start position:0% +eventually will reach Mutual equilibrium + + + align:start position:0% +eventually will reach Mutual equilibrium +with the reservoir and + + align:start position:0% +with the reservoir and + + + align:start position:0% +with the reservoir and +uh + + align:start position:0% +uh + + + align:start position:0% +uh +uh so if you at that stage I have + + align:start position:0% +uh so if you at that stage I have + + + align:start position:0% +uh so if you at that stage I have +blocked my piston cannot go up and down + + align:start position:0% +blocked my piston cannot go up and down + + + align:start position:0% +blocked my piston cannot go up and down +and I change Reservoir instead of having + + align:start position:0% +and I change Reservoir instead of having + + + align:start position:0% +and I change Reservoir instead of having +a reservoir at variable volume + + align:start position:0% +a reservoir at variable volume + + + align:start position:0% +a reservoir at variable volume +I have a reservoir at uh that can + + align:start position:0% +I have a reservoir at uh that can + + + align:start position:0% +I have a reservoir at uh that can +exchange that so at constant chemical + + align:start position:0% +exchange that so at constant chemical + + + align:start position:0% +exchange that so at constant chemical +potential of that substance + + align:start position:0% + + + + align:start position:0% + +CO2 + + align:start position:0% +CO2 + + + align:start position:0% +CO2 +okay uh the final state will be that + + align:start position:0% +okay uh the final state will be that + + + align:start position:0% +okay uh the final state will be that +instead of vacuum I will just have CO2 + + align:start position:0% +instead of vacuum I will just have CO2 + + + align:start position:0% +instead of vacuum I will just have CO2 +pure let's say that this will have a + + align:start position:0% +pure let's say that this will have a + + + align:start position:0% +pure let's say that this will have a +chemical potential that we will + + align:start position:0% +chemical potential that we will + + + align:start position:0% +chemical potential that we will +call MU + + align:start position:0% +call MU + + + align:start position:0% +call MU +I and it will have a pressure that + + align:start position:0% +I and it will have a pressure that + + + align:start position:0% +I and it will have a pressure that +corresponds to what we + + align:start position:0% +corresponds to what we + + + align:start position:0% +corresponds to what we +defined when they are in mutual + + align:start position:0% +defined when they are in mutual + + + align:start position:0% +defined when they are in mutual +equilibrium equality of chemical + + align:start position:0% +equilibrium equality of chemical + + + align:start position:0% +equilibrium equality of chemical +potentials defines the partial + + align:start position:0% +potentials defines the partial + + + align:start position:0% +potentials defines the partial +pressure so the CO2 will be at the + + align:start position:0% +pressure so the CO2 will be at the + + + align:start position:0% +pressure so the CO2 will be at the +partial pressure that it has in air + + align:start position:0% +partial pressure that it has in air + + + align:start position:0% +partial pressure that it has in air +viewed as a + + align:start position:0% +viewed as a + + + align:start position:0% +viewed as a +mixture okay + + align:start position:0% + + + + align:start position:0% + +this second part of the process from + + align:start position:0% +this second part of the process from + + + align:start position:0% +this second part of the process from +when I after I made vacuum and I stop + + align:start position:0% +when I after I made vacuum and I stop + + + align:start position:0% +when I after I made vacuum and I stop +the piston and I open the pory uh the + + align:start position:0% +the piston and I open the pory uh the + + + align:start position:0% +the piston and I open the pory uh the +second part of the process is + + align:start position:0% +second part of the process is + + + align:start position:0% +second part of the process is +spontaneous because + + align:start position:0% +spontaneous because + + + align:start position:0% +spontaneous because +initially you are in non equilibrium + + align:start position:0% +initially you are in non equilibrium + + + align:start position:0% +initially you are in non equilibrium +State because here you have no CO2 + + align:start position:0% +State because here you have no CO2 + + + align:start position:0% +State because here you have no CO2 +whereas in order for a equilibrium you + + align:start position:0% +whereas in order for a equilibrium you + + + align:start position:0% +whereas in order for a equilibrium you +need to have chemical potentials to be + + align:start position:0% +need to have chemical potentials to be + + + align:start position:0% +need to have chemical potentials to be +equal so this is an irreversible process + + align:start position:0% +equal so this is an irreversible process + + + align:start position:0% +equal so this is an irreversible process +there will be entropy produced by + + align:start position:0% +there will be entropy produced by + + + align:start position:0% +there will be entropy produced by +reversibility so this is not the best + + align:start position:0% +reversibility so this is not the best + + + align:start position:0% +reversibility so this is not the best +way to do it you could also evaluate how + + align:start position:0% +way to do it you could also evaluate how + + + align:start position:0% +way to do it you could also evaluate how +much is the efficiency if you could + + align:start position:0% +much is the efficiency if you could + + + align:start position:0% +much is the efficiency if you could +compare it with what's the minimum work + + align:start position:0% +compare it with what's the minimum work + + + align:start position:0% +compare it with what's the minimum work +that is required and the minimum work + + align:start position:0% +that is required and the minimum work + + + align:start position:0% +that is required and the minimum work +that is + + align:start position:0% +that is + + + align:start position:0% +that is +required is given + + align:start position:0% +required is given + + + align:start position:0% +required is given +here by this formula here I'm Sorry by + + align:start position:0% +here by this formula here I'm Sorry by + + + align:start position:0% +here by this formula here I'm Sorry by +this formula + + align:start position:0% +this formula + + + align:start position:0% +this formula +here so there is again another + + align:start position:0% +here so there is again another + + + align:start position:0% +here so there is again another +um available energy + + align:start position:0% +um available energy + + + align:start position:0% +um available energy +function I'm sorry available energy + + align:start position:0% + + + + align:start position:0% + +property for this particular kind of + + align:start position:0% +property for this particular kind of + + + align:start position:0% +property for this particular kind of +osmotic + + align:start position:0% + + + + align:start position:0% + +reservoirs the difference of which tells + + align:start position:0% +reservoirs the difference of which tells + + + align:start position:0% +reservoirs the difference of which tells +you the minimum or the maximum + + align:start position:0% +you the minimum or the maximum + + + align:start position:0% +you the minimum or the maximum +works for producing or or exploiting and + + align:start position:0% +works for producing or or exploiting and + + + align:start position:0% +works for producing or or exploiting and +the situation + + align:start position:0% + + + + align:start position:0% + +so we'll return later on uh to this + + align:start position:0% +so we'll return later on uh to this + + + align:start position:0% +so we'll return later on uh to this +question of minimum work for separating + + align:start position:0% +question of minimum work for separating + + + align:start position:0% +question of minimum work for separating +a substance from uh from from say the + + align:start position:0% + + + + align:start position:0% + +atmosphere + + align:start position:0% +atmosphere + + + align:start position:0% +atmosphere +here this combination that appears in + + align:start position:0% +here this combination that appears in + + + align:start position:0% +here this combination that appears in +the expression for this new version of + + align:start position:0% +the expression for this new version of + + + align:start position:0% +the expression for this new version of +the available energy namely e minus TRS + + align:start position:0% +the available energy namely e minus TRS + + + align:start position:0% +the available energy namely e minus TRS +minus the chemical potential + + align:start position:0% +minus the chemical potential + + + align:start position:0% +minus the chemical potential +times the amount of that substance that + + align:start position:0% +times the amount of that substance that + + + align:start position:0% +times the amount of that substance that +is can cross between the system and the + + align:start position:0% +is can cross between the system and the + + + align:start position:0% +is can cross between the system and the +reservoir we may give it a name or not + + align:start position:0% +reservoir we may give it a name or not + + + align:start position:0% +reservoir we may give it a name or not +simply an availability + + align:start position:0% +simply an availability + + + align:start position:0% +simply an availability +function maybe we could call it osmotic + + align:start position:0% +function maybe we could call it osmotic + + + align:start position:0% +function maybe we could call it osmotic +availability function maybe we could use + + align:start position:0% +availability function maybe we could use + + + align:start position:0% +availability function maybe we could use +this letter or another letter uh it's + + align:start position:0% +this letter or another letter uh it's + + + align:start position:0% +this letter or another letter uh it's +just a matter of + + align:start position:0% + + + + align:start position:0% + +choice as for for the other availability + + align:start position:0% +choice as for for the other availability + + + align:start position:0% +choice as for for the other availability +functions this also is + + align:start position:0% +functions this also is + + + align:start position:0% +functions this also is +minimum so also from this one you can + + align:start position:0% +minimum so also from this one you can + + + align:start position:0% +minimum so also from this one you can +derive by the + + align:start position:0% +derive by the + + + align:start position:0% +derive by the +same method as before same + + align:start position:0% + + + + align:start position:0% + +procedure conditions for stability of + + align:start position:0% +procedure conditions for stability of + + + align:start position:0% +procedure conditions for stability of +equilibrium for the second differential + + align:start position:0% +equilibrium for the second differential + + + align:start position:0% +equilibrium for the second differential +of the energy now it will be like uh uh + + align:start position:0% +of the energy now it will be like uh uh + + + align:start position:0% +of the energy now it will be like uh uh +this is but not with volume but with NI + + align:start position:0% +this is but not with volume but with NI + + + align:start position:0% +this is but not with volume but with NI +I uh that substitutes and that's the + + align:start position:0% + + + + align:start position:0% + +uh the the the expression for this + + align:start position:0% +uh the the the expression for this + + + align:start position:0% +uh the the the expression for this +second order + + align:start position:0% + + + + align:start position:0% + +differentials and finally we could have + + align:start position:0% +differentials and finally we could have + + + align:start position:0% +differentials and finally we could have +a grand situation okay so Grand + + align:start position:0% +a grand situation okay so Grand + + + align:start position:0% +a grand situation okay so Grand +Reservoir + + align:start position:0% + + + + align:start position:0% + +um with which + + align:start position:0% +um with which + + + align:start position:0% +um with which +you can your system can exchange + + align:start position:0% +you can your system can exchange + + + align:start position:0% +you can your system can exchange +anything it + + align:start position:0% +anything it + + + align:start position:0% +anything it +wants amounts volume energy and + + align:start position:0% + + + + align:start position:0% + +entropy + + align:start position:0% + + + + align:start position:0% + +okay so you have to run again the same + + align:start position:0% +okay so you have to run again the same + + + align:start position:0% +okay so you have to run again the same +Machinery energy balance entropy balance + + align:start position:0% +Machinery energy balance entropy balance + + + align:start position:0% +Machinery energy balance entropy balance +fundamental relation for the + + align:start position:0% +fundamental relation for the + + + align:start position:0% +fundamental relation for the +reservoir notice that PO in the previous + + align:start position:0% +reservoir notice that PO in the previous + + + align:start position:0% +reservoir notice that PO in the previous +case maybe I didn't emphasize it enough + + align:start position:0% +case maybe I didn't emphasize it enough + + + align:start position:0% +case maybe I didn't emphasize it enough +but what changes from Reservoir to + + align:start position:0% +but what changes from Reservoir to + + + align:start position:0% +but what changes from Reservoir to +Reservoir is the + + align:start position:0% +Reservoir is the + + + align:start position:0% +Reservoir is the +expression for the fundamental relation + + align:start position:0% +expression for the fundamental relation + + + align:start position:0% +expression for the fundamental relation +see these uh terms are + + align:start position:0% +see these uh terms are + + + align:start position:0% +see these uh terms are +new peculiar to this + + align:start position:0% +new peculiar to this + + + align:start position:0% +new peculiar to this +Reservoir that acts as a reservoir not + + align:start position:0% +Reservoir that acts as a reservoir not + + + align:start position:0% +Reservoir that acts as a reservoir not +only for exchanges of energy and entropy + + align:start position:0% +only for exchanges of energy and entropy + + + align:start position:0% +only for exchanges of energy and entropy +but also for if you change volume it + + align:start position:0% +but also for if you change volume it + + + align:start position:0% +but also for if you change volume it +doesn't change the pressure if you + + align:start position:0% +doesn't change the pressure if you + + + align:start position:0% +doesn't change the pressure if you +change the amounts it doesn't change the + + align:start position:0% +change the amounts it doesn't change the + + + align:start position:0% +change the amounts it doesn't change the +chemical + + align:start position:0% + + + + align:start position:0% + +potentials and then you have to uh + + align:start position:0% +potentials and then you have to uh + + + align:start position:0% +potentials and then you have to uh +remember also to do the + + align:start position:0% +remember also to do the + + + align:start position:0% +remember also to do the +volume balance and the balance balances + + align:start position:0% +volume balance and the balance balances + + + align:start position:0% +volume balance and the balance balances +for all of the amounts of the various + + align:start position:0% +for all of the amounts of the various + + + align:start position:0% +for all of the amounts of the various +constituents that are + + align:start position:0% +constituents that are + + + align:start position:0% +constituents that are +conserved now chemical reactions + + align:start position:0% + + + + align:start position:0% + +here again eliminate + + align:start position:0% +here again eliminate + + + align:start position:0% +here again eliminate +the terms that relate to + + align:start position:0% +the terms that relate to + + + align:start position:0% +the terms that relate to +the reservoir and you get this + + align:start position:0% +the reservoir and you get this + + + align:start position:0% +the reservoir and you get this +expression which is a + + align:start position:0% +expression which is a + + + align:start position:0% +expression which is a +another generalization of the available + + align:start position:0% +another generalization of the available + + + align:start position:0% +another generalization of the available +energy with respect to this completely + + align:start position:0% +energy with respect to this completely + + + align:start position:0% +energy with respect to this completely +open uh Reservoir and uh it's + + align:start position:0% +open uh Reservoir and uh it's + + + align:start position:0% +open uh Reservoir and uh it's +um this is the available energy the + + align:start position:0% +um this is the available energy the + + + align:start position:0% +um this is the available energy the +expression which can also be written as + + align:start position:0% +expression which can also be written as + + + align:start position:0% +expression which can also be written as +a difference in two + + align:start position:0% +a difference in two + + + align:start position:0% +a difference in two +values so the the work the maximum or + + align:start position:0% +values so the the work the maximum or + + + align:start position:0% +values so the the work the maximum or +minum the reversible work is the + + align:start position:0% +minum the reversible work is the + + + align:start position:0% +minum the reversible work is the +difference in the values of this new + + align:start position:0% +difference in the values of this new + + + align:start position:0% +difference in the values of this new +availability function which I like to + + align:start position:0% +availability function which I like to + + + align:start position:0% +availability function which I like to +call Oiler availability function for the + + align:start position:0% +call Oiler availability function for the + + + align:start position:0% +call Oiler availability function for the +reason I already explained uh the other + + align:start position:0% +reason I already explained uh the other + + + align:start position:0% +reason I already explained uh the other +time and that will be also clear uh + + align:start position:0% +time and that will be also clear uh + + + align:start position:0% +time and that will be also clear uh +later + + align:start position:0% +later + + + align:start position:0% +later +on so this e minus TRS plus PV minus mu + + align:start position:0% +on so this e minus TRS plus PV minus mu + + + align:start position:0% +on so this e minus TRS plus PV minus mu +RN this availability function is defined + + align:start position:0% +RN this availability function is defined + + + align:start position:0% +RN this availability function is defined +for all states equilibrium and non-e + + align:start position:0% +for all states equilibrium and non-e + + + align:start position:0% +for all states equilibrium and non-e +equilibrium when your system is + + align:start position:0% +equilibrium when your system is + + + align:start position:0% +equilibrium when your system is +in + + align:start position:0% +in + + + align:start position:0% +in +uh neutal equilibrium so so it is in the + + align:start position:0% +uh neutal equilibrium so so it is in the + + + align:start position:0% +uh neutal equilibrium so so it is in the +state at temperature TR pressure PR and + + align:start position:0% +state at temperature TR pressure PR and + + + align:start position:0% +state at temperature TR pressure PR and +with the chemical potential so complete + + align:start position:0% +with the chemical potential so complete + + + align:start position:0% +with the chemical potential so complete +equilibrium between system and + + align:start position:0% +equilibrium between system and + + + align:start position:0% +equilibrium between system and +Reservoir then this availability + + align:start position:0% +Reservoir then this availability + + + align:start position:0% +Reservoir then this availability +function we corresponds to that + + align:start position:0% +function we corresponds to that + + + align:start position:0% +function we corresponds to that +characteristic function that we called + + align:start position:0% +characteristic function that we called + + + align:start position:0% +characteristic function that we called +the + + align:start position:0% +the + + + align:start position:0% +the +oiler free energy + + align:start position:0% + + + + align:start position:0% + +that I just reviewed at the beginning of + + align:start position:0% +that I just reviewed at the beginning of + + + align:start position:0% +that I just reviewed at the beginning of +today + + align:start position:0% +today + + + align:start position:0% +today +okay and from this + + align:start position:0% + + + + align:start position:0% + +one this + + align:start position:0% +one this + + + align:start position:0% +one this +also is + + align:start position:0% +also is + + + align:start position:0% +also is +minimum at Mutual + + align:start position:0% + + + + align:start position:0% + +equilibrium and you can do the same + + align:start position:0% +equilibrium and you can do the same + + + align:start position:0% +equilibrium and you can do the same +again + + align:start position:0% + + + + align:start position:0% + +uh to EXT ract + + align:start position:0% +uh to EXT ract + + + align:start position:0% +uh to EXT ract +conditions for stability this + + align:start position:0% +conditions for stability this + + + align:start position:0% +conditions for stability this +time this + + align:start position:0% +time this + + + align:start position:0% +time this +expression D2 e is with respect not to + + align:start position:0% +expression D2 e is with respect not to + + + align:start position:0% +expression D2 e is with respect not to +just two variables so this + + align:start position:0% +just two variables so this + + + align:start position:0% +just two variables so this +Matrix uh the S Matrix will not be just + + align:start position:0% +Matrix uh the S Matrix will not be just + + + align:start position:0% +Matrix uh the S Matrix will not be just +2 by two but will be uh 2 + r because y + + align:start position:0% +2 by two but will be uh 2 + r because y + + + align:start position:0% +2 by two but will be uh 2 + r because y +also also can change all the + + align:start position:0% +also also can change all the + + + align:start position:0% +also also can change all the +constituents and if the our constituents + + align:start position:0% +constituents and if the our constituents + + + align:start position:0% +constituents and if the our constituents +is like a 2X two 2+ R by 2+ R so it's + + align:start position:0% +is like a 2X two 2+ R by 2+ R so it's + + + align:start position:0% +is like a 2X two 2+ R by 2+ R so it's +this Matrix that we have already + + align:start position:0% +this Matrix that we have already + + + align:start position:0% +this Matrix that we have already +anticipated a while + + align:start position:0% +anticipated a while + + + align:start position:0% +anticipated a while +ago and uh this therefore + + align:start position:0% +ago and uh this therefore + + + align:start position:0% +ago and uh this therefore +proves uh I mean here the details here + + align:start position:0% +proves uh I mean here the details here + + + align:start position:0% +proves uh I mean here the details here +prove in more detail + + align:start position:0% +prove in more detail + + + align:start position:0% +prove in more detail +also these expression that we had + + align:start position:0% + + + + align:start position:0% + +anticipated but you can also choose + + align:start position:0% + + + + align:start position:0% + +since now you you are you think that you + + align:start position:0% +since now you you are you think that you + + + align:start position:0% +since now you you are you think that you +are in a in a the mutual equilibrium + + align:start position:0% +are in a in a the mutual equilibrium + + + align:start position:0% +are in a in a the mutual equilibrium +State and then you can move your + + align:start position:0% +State and then you can move your + + + align:start position:0% +State and then you can move your +State uh in various + + align:start position:0% +State uh in various + + + align:start position:0% +State uh in various +directions and one + + align:start position:0% +directions and one + + + align:start position:0% +directions and one +way is that + + align:start position:0% +way is that + + + align:start position:0% +way is that +you choose another + + align:start position:0% +you choose another + + + align:start position:0% +you choose another +state + + align:start position:0% +state + + + align:start position:0% +state +that has still has the same temperature + + align:start position:0% +that has still has the same temperature + + + align:start position:0% +that has still has the same temperature +pressure of your reservo but you change + + align:start position:0% +pressure of your reservo but you change + + + align:start position:0% +pressure of your reservo but you change +the + + align:start position:0% +the + + + align:start position:0% +the +amount so you choose to move away from + + align:start position:0% +amount so you choose to move away from + + + align:start position:0% +amount so you choose to move away from +Mutual + + align:start position:0% +Mutual + + + align:start position:0% +Mutual +equilibrium because the conditions for + + align:start position:0% +equilibrium because the conditions for + + + align:start position:0% +equilibrium because the conditions for +Mutual equilibrium with res is not only + + align:start position:0% +Mutual equilibrium with res is not only + + + align:start position:0% +Mutual equilibrium with res is not only +now that it can exchange not only energy + + align:start position:0% +now that it can exchange not only energy + + + align:start position:0% +now that it can exchange not only energy +but also amounts it's not only the + + align:start position:0% +but also amounts it's not only the + + + align:start position:0% +but also amounts it's not only the +temperature equality it's also the + + align:start position:0% +temperature equality it's also the + + + align:start position:0% +temperature equality it's also the +pressure equality for the volume change + + align:start position:0% +pressure equality for the volume change + + + align:start position:0% +pressure equality for the volume change +and the chemical potentials or chemical + + align:start position:0% +and the chemical potentials or chemical + + + align:start position:0% +and the chemical potentials or chemical +potential so I can move away from Mutual + + align:start position:0% +potential so I can move away from Mutual + + + align:start position:0% +potential so I can move away from Mutual +equilibrium while keeping some of the + + align:start position:0% +equilibrium while keeping some of the + + + align:start position:0% +equilibrium while keeping some of the +mutual equilibrium conditions satisfied + + align:start position:0% +mutual equilibrium conditions satisfied + + + align:start position:0% +mutual equilibrium conditions satisfied +like same temperature and same pressure + + align:start position:0% +like same temperature and same pressure + + + align:start position:0% +like same temperature and same pressure +and moving only the + + align:start position:0% + + + + align:start position:0% + +amounts if you do that and move along uh + + align:start position:0% +amounts if you do that and move along uh + + + align:start position:0% +amounts if you do that and move along uh +the stable equilibrium State surface + + align:start position:0% +the stable equilibrium State surface + + + align:start position:0% +the stable equilibrium State surface +constant temperature and + + align:start position:0% + + + + align:start position:0% + +pressure uh the condition that Delta uh + + align:start position:0% +pressure uh the condition that Delta uh + + + align:start position:0% +pressure uh the condition that Delta uh +that that uh this um + + align:start position:0% + + + + align:start position:0% + +Oiler uh availability + + align:start position:0% +Oiler uh availability + + + align:start position:0% +Oiler uh availability +function must increase along that + + align:start position:0% +function must increase along that + + + align:start position:0% +function must increase along that +path turns out to be the change in this + + align:start position:0% +path turns out to be the change in this + + + align:start position:0% +path turns out to be the change in this +variable + + align:start position:0% +variable + + + align:start position:0% +variable +side is uh equal to the second + + align:start position:0% +side is uh equal to the second + + + align:start position:0% +side is uh equal to the second +differential of the Gibs free + + align:start position:0% + + + + align:start position:0% + +energy you you can prove it by + + align:start position:0% +energy you you can prove it by + + + align:start position:0% +energy you you can prove it by +remembering that the + + align:start position:0% +remembering that the + + + align:start position:0% +remembering that the +the Gibs V energy is e minus s minus TR + + align:start position:0% +the Gibs V energy is e minus s minus TR + + + align:start position:0% +the Gibs V energy is e minus s minus TR +and here TR and PR remain remain + + align:start position:0% +and here TR and PR remain remain + + + align:start position:0% +and here TR and PR remain remain +constant so it it remains + + align:start position:0% + + + + align:start position:0% + +defined so this proves that um the + + align:start position:0% +defined so this proves that um the + + + align:start position:0% +defined so this proves that um the +Gibs free + + align:start position:0% +Gibs free + + + align:start position:0% +Gibs free +energy as a minimum if you move so the + + align:start position:0% +energy as a minimum if you move so the + + + align:start position:0% +energy as a minimum if you move so the +second differential is non negative yes + + align:start position:0% +second differential is non negative yes + + + align:start position:0% +second differential is non negative yes +it's is non negative h if you move at + + align:start position:0% +it's is non negative h if you move at + + + align:start position:0% +it's is non negative h if you move at +con if you change the composition at + + align:start position:0% +con if you change the composition at + + + align:start position:0% +con if you change the composition at +constant + + align:start position:0% + + + + align:start position:0% + +tnp if you keep only temperature fixed + + align:start position:0% +tnp if you keep only temperature fixed + + + align:start position:0% +tnp if you keep only temperature fixed +and change the volume instead of keeping + + align:start position:0% +and change the volume instead of keeping + + + align:start position:0% +and change the volume instead of keeping +the pressure constant you get a similar + + align:start position:0% +the pressure constant you get a similar + + + align:start position:0% +the pressure constant you get a similar +relation this is not the givs free + + align:start position:0% +relation this is not the givs free + + + align:start position:0% +relation this is not the givs free +energy it's the elol free + + align:start position:0% +energy it's the elol free + + + align:start position:0% +energy it's the elol free +energy at constant t + + align:start position:0% + + + + align:start position:0% + +okay so remember that we have seen + + align:start position:0% +okay so remember that we have seen + + + align:start position:0% +okay so remember that we have seen +the that from these conditions here we + + align:start position:0% +the that from these conditions here we + + + align:start position:0% +the that from these conditions here we +obtain first part of the brown + + align:start position:0% +obtain first part of the brown + + + align:start position:0% +obtain first part of the brown +principle + + align:start position:0% +principle + + + align:start position:0% +principle +now + + align:start position:0% +now + + + align:start position:0% +now +yes another little piece of math sorry + + align:start position:0% +yes another little piece of math sorry + + + align:start position:0% +yes another little piece of math sorry +about + + align:start position:0% +about + + + align:start position:0% +about +that uh + + align:start position:0% +that uh + + + align:start position:0% +that uh +but that will get us to the second part + + align:start position:0% +but that will get us to the second part + + + align:start position:0% +but that will get us to the second part +of the chatellier brown principle so it + + align:start position:0% +of the chatellier brown principle so it + + + align:start position:0% +of the chatellier brown principle so it +is which is a more General uh + + align:start position:0% +is which is a more General uh + + + align:start position:0% +is which is a more General uh +statement + + align:start position:0% +statement + + + align:start position:0% +statement +which requires a little um uh brush + + align:start position:0% +which requires a little um uh brush + + + align:start position:0% +which requires a little um uh brush +up or maybe first time you see + + align:start position:0% +up or maybe first time you see + + + align:start position:0% +up or maybe first time you see +math + + align:start position:0% + + + + align:start position:0% + +uh so let's say we have a function + + align:start position:0% +uh so let's say we have a function + + + align:start position:0% +uh so let's say we have a function +for of two variables I put also the the + + align:start position:0% +for of two variables I put also the the + + + align:start position:0% +for of two variables I put also the the +other Z here just to say that the z's + + align:start position:0% +other Z here just to say that the z's + + + align:start position:0% +other Z here just to say that the z's +are going to be constant so I have + + align:start position:0% +are going to be constant so I have + + + align:start position:0% +are going to be constant so I have +several variables but I + + align:start position:0% +several variables but I + + + align:start position:0% +several variables but I +keep a constant all except two of them + + align:start position:0% +keep a constant all except two of them + + + align:start position:0% +keep a constant all except two of them +which are X and + + align:start position:0% + + + + align:start position:0% + +Y and then for example I have that + + align:start position:0% +Y and then for example I have that + + + align:start position:0% +Y and then for example I have that +function I can write the + + align:start position:0% + + + + align:start position:0% + +differential so that's the partial of a + + align:start position:0% +differential so that's the partial of a + + + align:start position:0% +differential so that's the partial of a +with respect to X + + align:start position:0% +with respect to X + + + align:start position:0% +with respect to X +time DX times the partial of a with + + align:start position:0% +time DX times the partial of a with + + + align:start position:0% +time DX times the partial of a with +respect to y * d y I'm going to use the + + align:start position:0% +respect to y * d y I'm going to use the + + + align:start position:0% +respect to y * d y I'm going to use the +notation comma X for partial with + + align:start position:0% +notation comma X for partial with + + + align:start position:0% +notation comma X for partial with +respect to X which is often used like in + + align:start position:0% +respect to X which is often used like in + + + align:start position:0% +respect to X which is often used like in +fluid mechanics so maybe you've seen it + + align:start position:0% +fluid mechanics so maybe you've seen it + + + align:start position:0% +fluid mechanics so maybe you've seen it +already or + + align:start position:0% + + + + align:start position:0% + +elsewhere and for example comma X is the + + align:start position:0% +elsewhere and for example comma X is the + + + align:start position:0% +elsewhere and for example comma X is the +second derivative with respect to X + + align:start position:0% +second derivative with respect to X + + + align:start position:0% +second derivative with respect to X +twice uh comma XY is the derivative of + + align:start position:0% +twice uh comma XY is the derivative of + + + align:start position:0% +twice uh comma XY is the derivative of +uh with respect to X and with respect to + + align:start position:0% + + + + align:start position:0% + +Y + + align:start position:0% +Y + + + align:start position:0% +Y +okay so this is the partial derivative + + align:start position:0% +okay so this is the partial derivative + + + align:start position:0% +okay so this is the partial derivative +with respect to + + align:start position:0% +with respect to + + + align:start position:0% +with respect to +X and here's the full Glory of uh the um + + align:start position:0% +X and here's the full Glory of uh the um + + + align:start position:0% +X and here's the full Glory of uh the um +representation of that + + align:start position:0% +representation of that + + + align:start position:0% +representation of that +derivatives uh where where the subs as + + align:start position:0% +derivatives uh where where the subs as + + + align:start position:0% +derivatives uh where where the subs as +you remember mean the other variables + + align:start position:0% + + + + align:start position:0% + +of the original function that you're + + align:start position:0% +of the original function that you're + + + align:start position:0% +of the original function that you're +taking the deriv the partial derivative + + align:start position:0% +taking the deriv the partial derivative + + + align:start position:0% +taking the deriv the partial derivative +of okay + + align:start position:0% +of okay + + + align:start position:0% +of okay +good then we + + align:start position:0% +good then we + + + align:start position:0% +good then we +have like we've seen there for d2s + + align:start position:0% +have like we've seen there for d2s + + + align:start position:0% +have like we've seen there for d2s +here's + + align:start position:0% +here's + + + align:start position:0% +here's +D2 of this variable + + align:start position:0% +D2 of this variable + + + align:start position:0% +D2 of this variable +a can think of s but it could be also + + align:start position:0% +a can think of s but it could be also + + + align:start position:0% +a can think of s but it could be also +others like the gifts fre energy or or + + align:start position:0% +others like the gifts fre energy or or + + + align:start position:0% +others like the gifts fre energy or or +the elos free energy or whatever you + + align:start position:0% +the elos free energy or whatever you + + + align:start position:0% +the elos free energy or whatever you +need + + align:start position:0% + + + + align:start position:0% + +and this is the quadratic + + align:start position:0% +and this is the quadratic + + + align:start position:0% +and this is the quadratic +form + + align:start position:0% +form + + + align:start position:0% +form +that represents the explicit + + align:start position:0% +that represents the explicit + + + align:start position:0% +that represents the explicit +form of the + + align:start position:0% +form of the + + + align:start position:0% +form of the +uh second or + + align:start position:0% +uh second or + + + align:start position:0% +uh second or +differential okay so now that we have a + + align:start position:0% +differential okay so now that we have a + + + align:start position:0% +differential okay so now that we have a +quadratic + + align:start position:0% +quadratic + + + align:start position:0% +quadratic +form the trick is to put it in the + + align:start position:0% +form the trick is to put it in the + + + align:start position:0% +form the trick is to put it in the +so-called canonical form because you see + + align:start position:0% +so-called canonical form because you see + + + align:start position:0% +so-called canonical form because you see +this quadratic + + align:start position:0% +this quadratic + + + align:start position:0% +this quadratic +form has a square here a square there + + align:start position:0% +form has a square here a square there + + + align:start position:0% +form has a square here a square there +and then it has a product DX + + align:start position:0% +and then it has a product DX + + + align:start position:0% +and then it has a product DX +Dy this isn't doesn't have a a definite + + align:start position:0% + + + + align:start position:0% + +sign + + align:start position:0% +sign + + + align:start position:0% +sign +but let's try to rewrite this quadratic + + align:start position:0% +but let's try to rewrite this quadratic + + + align:start position:0% +but let's try to rewrite this quadratic +form into a form in which you have + + align:start position:0% +form into a form in which you have + + + align:start position:0% +form into a form in which you have +something + + align:start position:0% +something + + + align:start position:0% +something +squared and uh Dy squared so a + + align:start position:0% +squared and uh Dy squared so a + + + align:start position:0% +squared and uh Dy squared so a +combination of DX and Dy proper + + align:start position:0% +combination of DX and Dy proper + + + align:start position:0% +combination of DX and Dy proper +combinate if you choose a proper + + align:start position:0% +combinate if you choose a proper + + + align:start position:0% +combinate if you choose a proper +combination of DX and D + + align:start position:0% +combination of DX and D + + + align:start position:0% +combination of DX and D +y uh and this is the proper combination + + align:start position:0% +y uh and this is the proper combination + + + align:start position:0% +y uh and this is the proper combination +I already built in the the answer so you + + align:start position:0% +I already built in the the answer so you + + + align:start position:0% +I already built in the the answer so you +if you want to check it you just + + align:start position:0% +if you want to check it you just + + + align:start position:0% +if you want to check it you just +substitute if you if you take this + + align:start position:0% +substitute if you if you take this + + + align:start position:0% +substitute if you if you take this +expression and work it out you will + + align:start position:0% +expression and work it out you will + + + align:start position:0% +expression and work it out you will +prove to yourself that it's equivalent + + align:start position:0% +prove to yourself that it's equivalent + + + align:start position:0% +prove to yourself that it's equivalent +to that + + align:start position:0% + + + + align:start position:0% + +one and this ratio this coefficient here + + align:start position:0% +one and this ratio this coefficient here + + + align:start position:0% +one and this ratio this coefficient here +is the ratio + + align:start position:0% +is the ratio + + + align:start position:0% +is the ratio +of uh the second derivative with respect + + align:start position:0% +of uh the second derivative with respect + + + align:start position:0% +of uh the second derivative with respect +to XY and divided by the second + + align:start position:0% +to XY and divided by the second + + + align:start position:0% +to XY and divided by the second +derivative respect to + + align:start position:0% + + + + align:start position:0% + +xx and then you find if you substitute + + align:start position:0% +xx and then you find if you substitute + + + align:start position:0% +xx and then you find if you substitute +by comparison you find that what you + + align:start position:0% +by comparison you find that what you + + + align:start position:0% +by comparison you find that what you +need to put in front of the Dy squ is + + align:start position:0% +need to put in front of the Dy squ is + + + align:start position:0% +need to put in front of the Dy squ is +this Lambda which is not sorry that I + + align:start position:0% +this Lambda which is not sorry that I + + + align:start position:0% +this Lambda which is not sorry that I +used Lambda here it's not the a + + align:start position:0% + + + + align:start position:0% + +values but this + + align:start position:0% +values but this + + + align:start position:0% +values but this +Lambda is given by this + + align:start position:0% +Lambda is given by this + + + align:start position:0% +Lambda is given by this +expression again terms of the + + align:start position:0% +expression again terms of the + + + align:start position:0% +expression again terms of the +original you can do it in this way where + + align:start position:0% +original you can do it in this way where + + + align:start position:0% +original you can do it in this way where +in your summation you get you keep the + + align:start position:0% +in your summation you get you keep the + + + align:start position:0% +in your summation you get you keep the +square of the Y squared or you can do it + + align:start position:0% +square of the Y squared or you can do it + + + align:start position:0% +square of the Y squared or you can do it +also in this other way this is another + + align:start position:0% +also in this other way this is another + + + align:start position:0% +also in this other way this is another +canonical form in which you keep the X + + align:start position:0% +canonical form in which you keep the X + + + align:start position:0% +canonical form in which you keep the X +squar they + + align:start position:0% +squar they + + + align:start position:0% +squar they +are two equivalent + + align:start position:0% +are two equivalent + + + align:start position:0% +are two equivalent +ways of course here the Lambda is + + align:start position:0% +ways of course here the Lambda is + + + align:start position:0% +ways of course here the Lambda is +different than the Lambda X is given by + + align:start position:0% +different than the Lambda X is given by + + + align:start position:0% +different than the Lambda X is given by +this + + align:start position:0% + + + + align:start position:0% + +one okay + + align:start position:0% + + + + align:start position:0% + +now do I have more + + align:start position:0% + + + + align:start position:0% + +space + + align:start position:0% +space + + + align:start position:0% +space +now let's look at + + align:start position:0% +now let's look at + + + align:start position:0% +now let's look at +uh + + align:start position:0% +uh + + + align:start position:0% +uh +suppose that our function a is such that + + align:start position:0% +suppose that our function a is such that + + + align:start position:0% +suppose that our function a is such that +it's uh second differential must be + + align:start position:0% +it's uh second differential must be + + + align:start position:0% +it's uh second differential must be +positive okay + + align:start position:0% +positive okay + + + align:start position:0% +positive okay +so positive + + align:start position:0% +so positive + + + align:start position:0% +so positive +means that this Matrix is positive + + align:start position:0% +means that this Matrix is positive + + + align:start position:0% +means that this Matrix is positive +definite or semide + + align:start position:0% + + + + align:start position:0% + +definite and as as we remember yeah I + + align:start position:0% +definite and as as we remember yeah I + + + align:start position:0% +definite and as as we remember yeah I +took away the wrong so if we + + align:start position:0% +took away the wrong so if we + + + align:start position:0% +took away the wrong so if we +remember uh positive definite for a + + align:start position:0% +remember uh positive definite for a + + + align:start position:0% +remember uh positive definite for a +matrix imply + + align:start position:0% +matrix imply + + + align:start position:0% +matrix imply +all these things are + + align:start position:0% +all these things are + + + align:start position:0% +all these things are +positive or non + + align:start position:0% + + + + align:start position:0% + +negative so we have to have that + + align:start position:0% +negative so we have to have that + + + align:start position:0% +negative so we have to have that +axx is greater than + + align:start position:0% +axx is greater than + + + align:start position:0% +axx is greater than +zero and in fact here that's what I have + + align:start position:0% +zero and in fact here that's what I have + + + align:start position:0% +zero and in fact here that's what I have +written + + align:start position:0% +written + + + align:start position:0% +written +axx is greater than zero it's greater + + align:start position:0% +axx is greater than zero it's greater + + + align:start position:0% +axx is greater than zero it's greater +than something else is greater than zero + + align:start position:0% +than something else is greater than zero + + + align:start position:0% +than something else is greater than zero +and also a y I is greater than + + align:start position:0% + + + + align:start position:0% + +zero + + align:start position:0% +zero + + + align:start position:0% +zero +but here we have written also something + + align:start position:0% +but here we have written also something + + + align:start position:0% +but here we have written also something +more strong than + + align:start position:0% +more strong than + + + align:start position:0% +more strong than +that we have written that a XX or a y y + + align:start position:0% +that we have written that a XX or a y y + + + align:start position:0% +that we have written that a XX or a y y +is greater than + + align:start position:0% +is greater than + + + align:start position:0% +is greater than +Lambda let's + + align:start position:0% +Lambda let's + + + align:start position:0% +Lambda let's +see + + align:start position:0% +see + + + align:start position:0% +see +um the + + align:start position:0% + + + + align:start position:0% + +Lambda uh + + align:start position:0% +Lambda uh + + + align:start position:0% +Lambda uh +Tai yeah I can write it + + align:start position:0% +Tai yeah I can write it + + + align:start position:0% +Tai yeah I can write it +there + + align:start position:0% +there + + + align:start position:0% +there +um see for example Lambda + + align:start position:0% + + + + align:start position:0% + +y let me rewrite it uh this way uh it + + align:start position:0% +y let me rewrite it uh this way uh it + + + align:start position:0% +y let me rewrite it uh this way uh it +has that the + + align:start position:0% +has that the + + + align:start position:0% +has that the +denominator a xx + + align:start position:0% + + + + align:start position:0% + +squ and at the denominate I'm sorry at + + align:start position:0% +squ and at the denominate I'm sorry at + + + align:start position:0% +squ and at the denominate I'm sorry at +the yeah denominator there and numerator + + align:start position:0% +the yeah denominator there and numerator + + + align:start position:0% +the yeah denominator there and numerator +a XX time + + align:start position:0% +a XX time + + + align:start position:0% +a XX time +a y + + align:start position:0% +a y + + + align:start position:0% +a y +y minus a + + align:start position:0% +y minus a + + + align:start position:0% +y minus a +XY + + align:start position:0% +XY + + + align:start position:0% +XY +squar that is the + + align:start position:0% +squar that is the + + + align:start position:0% +squar that is the +determinant of the S + + align:start position:0% + + + + align:start position:0% + +Matrix that + + align:start position:0% + + + + align:start position:0% + +numerator + + align:start position:0% +numerator + + + align:start position:0% +numerator +so since the Matrix is positive the + + align:start position:0% +so since the Matrix is positive the + + + align:start position:0% +so since the Matrix is positive the +numerator is positive the denominator is + + align:start position:0% +numerator is positive the denominator is + + + align:start position:0% +numerator is positive the denominator is +positive so this is also + + align:start position:0% +positive so this is also + + + align:start position:0% +positive so this is also +positive + + align:start position:0% +positive + + + align:start position:0% +positive +okay so Lambda so this explains why + + align:start position:0% + + + + align:start position:0% + +Lambda uh you can do that for y but also + + align:start position:0% +Lambda uh you can do that for y but also + + + align:start position:0% +Lambda uh you can do that for y but also +for + + align:start position:0% +for + + + align:start position:0% +for +x uh the lambdas are also non + + align:start position:0% + + + + align:start position:0% + +negative and now you can also see here y + + align:start position:0% +negative and now you can also see here y + + + align:start position:0% +negative and now you can also see here y +Lambda uh for example Lambda + + align:start position:0% +Lambda uh for example Lambda + + + align:start position:0% +Lambda uh for example Lambda +Y is smaller than a y y because you look + + align:start position:0% +Y is smaller than a y y because you look + + + align:start position:0% +Y is smaller than a y y because you look +look here this is lamb this is a and + + align:start position:0% +look here this is lamb this is a and + + + align:start position:0% +look here this is lamb this is a and +then you subtract something + + align:start position:0% +then you subtract something + + + align:start position:0% +then you subtract something +positive so if if you from a you + + align:start position:0% +positive so if if you from a you + + + align:start position:0% +positive so if if you from a you +subtract something positive it means + + align:start position:0% +subtract something positive it means + + + align:start position:0% +subtract something positive it means +that Lambda is smaller than a i a y + + align:start position:0% +that Lambda is smaller than a i a y + + + align:start position:0% +that Lambda is smaller than a i a y +y + + align:start position:0% +y + + + align:start position:0% +y +okay all right so this is the + + align:start position:0% +okay all right so this is the + + + align:start position:0% +okay all right so this is the +mathematics that uh + + align:start position:0% +mathematics that uh + + + align:start position:0% +mathematics that uh +stands uh that supports that stands + + align:start position:0% +stands uh that supports that stands + + + align:start position:0% +stands uh that supports that stands +behind the um the next the The Brown + + align:start position:0% +behind the um the next the The Brown + + + align:start position:0% +behind the um the next the The Brown +principle that we're going to do in a + + align:start position:0% +principle that we're going to do in a + + + align:start position:0% +principle that we're going to do in a +second of course you can do exactly the + + align:start position:0% +second of course you can do exactly the + + + align:start position:0% +second of course you can do exactly the +same that I've done here + + align:start position:0% +same that I've done here + + + align:start position:0% +same that I've done here +for uh positive semide definite you can + + align:start position:0% +for uh positive semide definite you can + + + align:start position:0% +for uh positive semide definite you can +also do it for negative + + align:start position:0% + + + + align:start position:0% + +sem okay + + align:start position:0% + + + + align:start position:0% + +these + + align:start position:0% + + + + align:start position:0% + +steps help understanding uh + + align:start position:0% +steps help understanding uh + + + align:start position:0% +steps help understanding uh +the various steps on the previous + + align:start position:0% +the various steps on the previous + + + align:start position:0% +the various steps on the previous +uh + + align:start position:0% + + + + align:start position:0% + +slide and + + align:start position:0% +slide and + + + align:start position:0% +slide and +uh the bottom line is is here you can uh + + align:start position:0% +uh the bottom line is is here you can uh + + + align:start position:0% +uh the bottom line is is here you can uh +um rewrite that aou + + align:start position:0% + + + + align:start position:0% + +X it it this is equal to the + + align:start position:0% +X it it this is equal to the + + + align:start position:0% +X it it this is equal to the +partial of ax which is the conjugate + + align:start position:0% +partial of ax which is the conjugate + + + align:start position:0% +partial of ax which is the conjugate +potential to variable uh uh X so + + align:start position:0% + + + + align:start position:0% + +um yeah so suppose suppose our function + + align:start position:0% +um yeah so suppose suppose our function + + + align:start position:0% +um yeah so suppose suppose our function +is + + align:start position:0% +is + + + align:start position:0% +is +S and + + align:start position:0% + + + + align:start position:0% + +S is a function of energy and so s e e + + align:start position:0% +S is a function of energy and so s e e + + + align:start position:0% +S is a function of energy and so s e e +which is the equivalent so our functions + + align:start position:0% +which is the equivalent so our functions + + + align:start position:0% +which is the equivalent so our functions +is the entropy and X variable is the + + align:start position:0% +is the entropy and X variable is the + + + align:start position:0% +is the entropy and X variable is the +energy + + align:start position:0% +energy + + + align:start position:0% +energy +so s e e means partial of s with respect + + align:start position:0% +so s e e means partial of s with respect + + + align:start position:0% +so s e e means partial of s with respect +to e twice but since the partial of s + + align:start position:0% +to e twice but since the partial of s + + + align:start position:0% +to e twice but since the partial of s +with respect to + + align:start position:0% +with respect to + + + align:start position:0% +with respect to +e is 1 / t + + align:start position:0% + + + + align:start position:0% + +Okay so this is equivalent also to the + + align:start position:0% +Okay so this is equivalent also to the + + + align:start position:0% +Okay so this is equivalent also to the +the you can write it + + align:start position:0% +the you can write it + + + align:start position:0% +the you can write it +as s comma e which is the inverse of the + + align:start position:0% +as s comma e which is the inverse of the + + + align:start position:0% +as s comma e which is the inverse of the +temperature the gain comma + + align:start position:0% + + + + align:start position:0% + +e and of course you can do also the + + align:start position:0% +e and of course you can do also the + + + align:start position:0% +e and of course you can do also the +other uh like that so this is the + + align:start position:0% +other uh like that so this is the + + + align:start position:0% +other uh like that so this is the +meaning of partial of the a comma X + + align:start position:0% +meaning of partial of the a comma X + + + align:start position:0% +meaning of partial of the a comma X +again comma X done at constant + + align:start position:0% + + + + align:start position:0% + +y the point is + + align:start position:0% +y the point is + + + align:start position:0% +y the point is +that uh by doing this math here that I + + align:start position:0% +that uh by doing this math here that I + + + align:start position:0% +that uh by doing this math here that I +want to skip + + align:start position:0% +want to skip + + + align:start position:0% +want to skip +uh I have uh um I prove that the Lambda + + align:start position:0% +uh I have uh um I prove that the Lambda + + + align:start position:0% +uh I have uh um I prove that the Lambda +also the lambdas can be written as + + align:start position:0% +also the lambdas can be written as + + + align:start position:0% +also the lambdas can be written as +partials of um this potential so on the + + align:start position:0% +partials of um this potential so on the + + + align:start position:0% +partials of um this potential so on the +first derivative respect to X but not + + align:start position:0% +first derivative respect to X but not + + + align:start position:0% +first derivative respect to X but not +while keeping y constant y but but while + + align:start position:0% +while keeping y constant y but but while + + + align:start position:0% +while keeping y constant y but but while +keeping constant the other + + align:start position:0% +keeping constant the other + + + align:start position:0% +keeping constant the other +potential conjugated to + + align:start position:0% +potential conjugated to + + + align:start position:0% +potential conjugated to +Y okay + + align:start position:0% +Y okay + + + align:start position:0% +Y okay +so what changes in these two terms is + + align:start position:0% +so what changes in these two terms is + + + align:start position:0% +so what changes in these two terms is +what is kept constant here I keep + + align:start position:0% +what is kept constant here I keep + + + align:start position:0% +what is kept constant here I keep +constant y here I say I keep I keep + + align:start position:0% +constant y here I say I keep I keep + + + align:start position:0% +constant y here I say I keep I keep +constant the potential conjugated to + + align:start position:0% +constant the potential conjugated to + + + align:start position:0% +constant the potential conjugated to +Y and that's the + + align:start position:0% +Y and that's the + + + align:start position:0% +Y and that's the +key to + + align:start position:0% + + + + align:start position:0% + +uh to the the Practical uh consequences + + align:start position:0% +uh to the the Practical uh consequences + + + align:start position:0% +uh to the the Practical uh consequences +of these mathematics + + align:start position:0% +of these mathematics + + + align:start position:0% +of these mathematics +so for + + align:start position:0% +so for + + + align:start position:0% +so for +example let's change once more variable + + align:start position:0% +example let's change once more variable + + + align:start position:0% +example let's change once more variable +so that we you get uh a more confused + + align:start position:0% +so that we you get uh a more confused + + + align:start position:0% +so that we you get uh a more confused +but we just have five minutes so it's + + align:start position:0% +but we just have five minutes so it's + + + align:start position:0% +but we just have five minutes so it's +okay uh so we start from a function + + align:start position:0% +okay uh so we start from a function + + + align:start position:0% +okay uh so we start from a function +E from this fundamental relation this + + align:start position:0% +E from this fundamental relation this + + + align:start position:0% +E from this fundamental relation this +form of the fundamental + + align:start position:0% +form of the fundamental + + + align:start position:0% +form of the fundamental +relation keep the end fixed and look at + + align:start position:0% +relation keep the end fixed and look at + + + align:start position:0% +relation keep the end fixed and look at +what happens by applying what we've just + + align:start position:0% +what happens by applying what we've just + + + align:start position:0% +what happens by applying what we've just +seen + + align:start position:0% + + + + align:start position:0% + +this is the train of inequalities that + + align:start position:0% +this is the train of inequalities that + + + align:start position:0% +this is the train of inequalities that +is implied by one of the forms by this + + align:start position:0% +is implied by one of the forms by this + + + align:start position:0% +is implied by one of the forms by this +form and by the second form is written + + align:start position:0% +form and by the second form is written + + + align:start position:0% +form and by the second form is written +here you can do the + + align:start position:0% +here you can do the + + + align:start position:0% +here you can do the +substitutions uh you see I put here what + + align:start position:0% +substitutions uh you see I put here what + + + align:start position:0% +substitutions uh you see I put here what +the variable X Y is what a subx a sub y + + align:start position:0% +the variable X Y is what a subx a sub y + + + align:start position:0% +the variable X Y is what a subx a sub y +called the temperature and the pressure + + align:start position:0% +called the temperature and the pressure + + + align:start position:0% +called the temperature and the pressure +in our case and here is a + + align:start position:0% + + + + align:start position:0% + +result now by the way by looking at + + align:start position:0% +result now by the way by looking at + + + align:start position:0% +result now by the way by looking at +these derivatives you find all friends + + align:start position:0% +these derivatives you find all friends + + + align:start position:0% +these derivatives you find all friends +and you can see that for example you can + + align:start position:0% +and you can see that for example you can + + + align:start position:0% +and you can see that for example you can +rewrite this as + + align:start position:0% +rewrite this as + + + align:start position:0% +rewrite this as +CP is greater than or equal to CV which + + align:start position:0% +CP is greater than or equal to CV which + + + align:start position:0% +CP is greater than or equal to CV which +is greater than equal to zero or that + + align:start position:0% +is greater than equal to zero or that + + + align:start position:0% +is greater than equal to zero or that +one the compressibility constant + + align:start position:0% +one the compressibility constant + + + align:start position:0% +one the compressibility constant +temperature is greater than a + + align:start position:0% +temperature is greater than a + + + align:start position:0% +temperature is greater than a +compressibility at constant + + align:start position:0% +compressibility at constant + + + align:start position:0% +compressibility at constant +entropy okay + + align:start position:0% +entropy okay + + + align:start position:0% +entropy okay +so what's the + + align:start position:0% +so what's the + + + align:start position:0% +so what's the +reading that the chatel brown + + align:start position:0% + + + + align:start position:0% + +does so what's the difference here + + align:start position:0% +does so what's the difference here + + + align:start position:0% +does so what's the difference here +between V the what is what is the + + align:start position:0% +between V the what is what is the + + + align:start position:0% +between V the what is what is the +difference between these two derivatives + + align:start position:0% +difference between these two derivatives + + + align:start position:0% +difference between these two derivatives +is what is kept + + align:start position:0% +is what is kept + + + align:start position:0% +is what is kept +constant I change the entropy and + + align:start position:0% +constant I change the entropy and + + + align:start position:0% +constant I change the entropy and +measure what temperature change + + align:start position:0% +measure what temperature change + + + align:start position:0% +measure what temperature change +occurs uh when I keep volume or when I + + align:start position:0% +occurs uh when I keep volume or when I + + + align:start position:0% +occurs uh when I keep volume or when I +keep uh pressure + + align:start position:0% + + + + align:start position:0% + +fixed you see + + align:start position:0% +fixed you see + + + align:start position:0% +fixed you see +volume + + align:start position:0% +volume + + + align:start position:0% +volume +is the original variable pressure is the + + align:start position:0% +is the original variable pressure is the + + + align:start position:0% +is the original variable pressure is the +conjugated potential it has to do with + + align:start position:0% +conjugated potential it has to do with + + + align:start position:0% +conjugated potential it has to do with +the tendency to escape uh to to to gain + + align:start position:0% +the tendency to escape uh to to to gain + + + align:start position:0% +the tendency to escape uh to to to gain +volume so minus pressure is the tendency + + align:start position:0% +volume so minus pressure is the tendency + + + align:start position:0% +volume so minus pressure is the tendency +to yield + + align:start position:0% + + + + align:start position:0% + +volume so the the idea is that you know + + align:start position:0% +volume so the the idea is that you know + + + align:start position:0% +volume so the the idea is that you know +that the interpretation of these + + align:start position:0% +that the interpretation of these + + + align:start position:0% +that the interpretation of these +derivatives being positive is that the + + align:start position:0% +derivatives being positive is that the + + + align:start position:0% +derivatives being positive is that the +system uh reacts if you move it away + + align:start position:0% +system uh reacts if you move it away + + + align:start position:0% +system uh reacts if you move it away +from the mutual equilibrium state from + + align:start position:0% +from the mutual equilibrium state from + + + align:start position:0% +from the mutual equilibrium state from +of the + + align:start position:0% +of the + + + align:start position:0% +of the +environment uh you add some entropy for + + align:start position:0% +environment uh you add some entropy for + + + align:start position:0% +environment uh you add some entropy for +example it will increase its temperature + + align:start position:0% +example it will increase its temperature + + + align:start position:0% +example it will increase its temperature +this is + + align:start position:0% +this is + + + align:start position:0% +this is +positive so as to increase its uh + + align:start position:0% +positive so as to increase its uh + + + align:start position:0% +positive so as to increase its uh +uh tendency + + align:start position:0% +uh tendency + + + align:start position:0% +uh tendency +to return energy to contrast your change + + align:start position:0% +to return energy to contrast your change + + + align:start position:0% +to return energy to contrast your change +by giving energy giving energy away to + + align:start position:0% +by giving energy giving energy away to + + + align:start position:0% +by giving energy giving energy away to +your environment so the system responds + + align:start position:0% +your environment so the system responds + + + align:start position:0% +your environment so the system responds +by trying to uh spontaneously + + align:start position:0% +by trying to uh spontaneously + + + align:start position:0% +by trying to uh spontaneously +reestablish + + align:start position:0% +reestablish + + + align:start position:0% +reestablish +equilibrium but it does more + + align:start position:0% +equilibrium but it does more + + + align:start position:0% +equilibrium but it does more +so if you do it at constant volume than + + align:start position:0% +so if you do it at constant volume than + + + align:start position:0% +so if you do it at constant volume than +if you do it at constant pressure so the + + align:start position:0% +if you do it at constant pressure so the + + + align:start position:0% +if you do it at constant pressure so the +reaction of the system is + + align:start position:0% +reaction of the system is + + + align:start position:0% +reaction of the system is +stronger uh + + align:start position:0% +stronger uh + + + align:start position:0% +stronger uh +if if what so what's the difference the + + align:start position:0% +if if what so what's the difference the + + + align:start position:0% +if if what so what's the difference the +difference is that + + align:start position:0% +difference is that + + + align:start position:0% +difference is that +here the system as as a smaller reaction + + align:start position:0% +here the system as as a smaller reaction + + + align:start position:0% +here the system as as a smaller reaction +if you + + align:start position:0% +if you + + + align:start position:0% +if you +keep keeping the pressure constant means + + align:start position:0% +keep keeping the pressure constant means + + + align:start position:0% +keep keeping the pressure constant means +means keeping your + + align:start position:0% +means keeping your + + + align:start position:0% +means keeping your +system uh in equilibrium with your res + + align:start position:0% +system uh in equilibrium with your res + + + align:start position:0% +system uh in equilibrium with your res +at least as for the condition that + + align:start position:0% +at least as for the condition that + + + align:start position:0% +at least as for the condition that +requires pressure equality so you're not + + align:start position:0% +requires pressure equality so you're not + + + align:start position:0% +requires pressure equality so you're not +touching that condition for Mutual + + align:start position:0% +touching that condition for Mutual + + + align:start position:0% +touching that condition for Mutual +equilibrium you're touching also some + + align:start position:0% +equilibrium you're touching also some + + + align:start position:0% +equilibrium you're touching also some +something else so if you if you do it + + align:start position:0% +something else so if you if you do it + + + align:start position:0% +something else so if you if you do it +there the system says all right well + + align:start position:0% +there the system says all right well + + + align:start position:0% +there the system says all right well +after all you're you're moving me away + + align:start position:0% +after all you're you're moving me away + + + align:start position:0% +after all you're you're moving me away +but not so much so its reaction is + + align:start position:0% +but not so much so its reaction is + + + align:start position:0% +but not so much so its reaction is +softer if you move it away so that also + + align:start position:0% +softer if you move it away so that also + + + align:start position:0% +softer if you move it away so that also +its pressure changes and therefore like + + align:start position:0% +its pressure changes and therefore like + + + align:start position:0% +its pressure changes and therefore like +you do when you keep the volume constant + + align:start position:0% +you do when you keep the volume constant + + + align:start position:0% +you do when you keep the volume constant +uh then it will U it will uh in in + + align:start position:0% +uh then it will U it will uh in in + + + align:start position:0% +uh then it will U it will uh in in +increase uh not + + align:start position:0% +increase uh not + + + align:start position:0% +increase uh not +only so essentially you are + + align:start position:0% +only so essentially you are + + + align:start position:0% +only so essentially you are +touching two conditions of Mutual + + align:start position:0% +touching two conditions of Mutual + + + align:start position:0% +touching two conditions of Mutual +equilibrium touching equality of + + align:start position:0% +equilibrium touching equality of + + + align:start position:0% +equilibrium touching equality of +temperature and touching equality of + + align:start position:0% +temperature and touching equality of + + + align:start position:0% +temperature and touching equality of +pressure and therefore the system reacts + + align:start position:0% +pressure and therefore the system reacts + + + align:start position:0% +pressure and therefore the system reacts +stronger wants more to come back to + + align:start position:0% + + + + align:start position:0% + +equilibrium this is the uh this is the + + align:start position:0% +equilibrium this is the uh this is the + + + align:start position:0% +equilibrium this is the uh this is the +um uh the idea and since I wanted + + align:start position:0% +um uh the idea and since I wanted + + + align:start position:0% +um uh the idea and since I wanted +to to give me two more minutes I wanted + + align:start position:0% +to to give me two more minutes I wanted + + + align:start position:0% +to to give me two more minutes I wanted +to uh show you the uh + + align:start position:0% +to uh show you the uh + + + align:start position:0% +to uh show you the uh +application + + align:start position:0% +application + + + align:start position:0% +application +here you know uh this is an air spring + + align:start position:0% +here you know uh this is an air spring + + + align:start position:0% +here you know uh this is an air spring +so it's like a piston with air + + align:start position:0% +so it's like a piston with air + + + align:start position:0% +so it's like a piston with air +inside and it acts like a standard uh + + align:start position:0% +inside and it acts like a standard uh + + + align:start position:0% +inside and it acts like a standard uh +mechanical spring you can compute the + + align:start position:0% +mechanical spring you can compute the + + + align:start position:0% +mechanical spring you can compute the +spring + + align:start position:0% +spring + + + align:start position:0% +spring +constant and you here are the details + + align:start position:0% +constant and you here are the details + + + align:start position:0% +constant and you here are the details +it's kind of easy um mechanical + + align:start position:0% +it's kind of easy um mechanical + + + align:start position:0% +it's kind of easy um mechanical +engineering so to + + align:start position:0% +engineering so to + + + align:start position:0% +engineering so to +speak uh so the cake this uh K is the K + + align:start position:0% +speak uh so the cake this uh K is the K + + + align:start position:0% +speak uh so the cake this uh K is the K +the the spring constant that + + align:start position:0% +the the spring constant that + + + align:start position:0% +the the spring constant that +relates the increasing uh reaction or + + align:start position:0% +relates the increasing uh reaction or + + + align:start position:0% +relates the increasing uh reaction or +force of your spring to a change in its + + align:start position:0% +force of your spring to a change in its + + + align:start position:0% +force of your spring to a change in its +uh + + align:start position:0% + + + + align:start position:0% + +compression and this is also similar + + align:start position:0% +compression and this is also similar + + + align:start position:0% +compression and this is also similar +situation it this acts as a + + align:start position:0% +situation it this acts as a + + + align:start position:0% +situation it this acts as a +spring and you can + + align:start position:0% +spring and you can + + + align:start position:0% +spring and you can +compute uh DF over DX + + align:start position:0% +compute uh DF over DX + + + align:start position:0% +compute uh DF over DX +and uh if you do go down here you see + + align:start position:0% +and uh if you do go down here you see + + + align:start position:0% +and uh if you do go down here you see +it's related to how much the area little + + align:start position:0% +it's related to how much the area little + + + align:start position:0% +it's related to how much the area little +a of the Piston the + + align:start position:0% +a of the Piston the + + + align:start position:0% +a of the Piston the +volume and this thing as a denominator + + align:start position:0% +volume and this thing as a denominator + + + align:start position:0% +volume and this thing as a denominator +is the + + align:start position:0% + + + + align:start position:0% + +compressibility so you could have U so + + align:start position:0% +compressibility so you could have U so + + + align:start position:0% +compressibility so you could have U so +if you act your + + align:start position:0% +if you act your + + + align:start position:0% +if you act your +spring while keeping the temperature + + align:start position:0% +spring while keeping the temperature + + + align:start position:0% +spring while keeping the temperature +constant so if your spring uh is in + + align:start position:0% +constant so if your spring uh is in + + + align:start position:0% +constant so if your spring uh is in +contact with the th + + align:start position:0% +contact with the th + + + align:start position:0% +contact with the th +were and therefore it has the time to + + align:start position:0% +were and therefore it has the time to + + + align:start position:0% +were and therefore it has the time to +exchange energy to remain in mutual + + align:start position:0% +exchange energy to remain in mutual + + + align:start position:0% +exchange energy to remain in mutual +equilibrium which typically is when you + + align:start position:0% +equilibrium which typically is when you + + + align:start position:0% +equilibrium which typically is when you +push it but push it slow enough so that + + align:start position:0% +push it but push it slow enough so that + + + align:start position:0% +push it but push it slow enough so that +the system has time to uh exchange heat + + align:start position:0% +the system has time to uh exchange heat + + + align:start position:0% +the system has time to uh exchange heat +with the environment and remain in + + align:start position:0% +with the environment and remain in + + + align:start position:0% +with the environment and remain in +equilibrium then you get one spring + + align:start position:0% +equilibrium then you get one spring + + + align:start position:0% +equilibrium then you get one spring +constant If instead you push a spring + + align:start position:0% +constant If instead you push a spring + + + align:start position:0% +constant If instead you push a spring +fast like when the car goes on on a on a + + align:start position:0% +fast like when the car goes on on a on a + + + align:start position:0% +fast like when the car goes on on a on a +bump + + align:start position:0% +bump + + + align:start position:0% +bump +uh that the system doesn't have time to + + align:start position:0% +uh that the system doesn't have time to + + + align:start position:0% +uh that the system doesn't have time to +exchange energy or or heat and the + + align:start position:0% +exchange energy or or heat and the + + + align:start position:0% +exchange energy or or heat and the +entropy remains + + align:start position:0% +entropy remains + + + align:start position:0% +entropy remains +constant so that's the + + align:start position:0% +constant so that's the + + + align:start position:0% +constant so that's the +isothermal uh compress I'm sorry the + + align:start position:0% +isothermal uh compress I'm sorry the + + + align:start position:0% +isothermal uh compress I'm sorry the +isentropic compressibility that + + align:start position:0% +isentropic compressibility that + + + align:start position:0% +isentropic compressibility that +appears and so you see that the ratio of + + align:start position:0% +appears and so you see that the ratio of + + + align:start position:0% +appears and so you see that the ratio of +these two compress of these two uh spray + + align:start position:0% +these two compress of these two uh spray + + + align:start position:0% +these two compress of these two uh spray +constants + + align:start position:0% + + + + align:start position:0% + +is + + align:start position:0% +is + + + align:start position:0% +is +equal to CP over C CV which for air is + + align:start position:0% +equal to CP over C CV which for air is + + + align:start position:0% +equal to CP over C CV which for air is +1.4 we just + + align:start position:0% +1.4 we just + + + align:start position:0% +1.4 we just +reviewed so that means that U if you act + + align:start position:0% +reviewed so that means that U if you act + + + align:start position:0% +reviewed so that means that U if you act +on the spring fast you get the spring + + align:start position:0% +on the spring fast you get the spring + + + align:start position:0% +on the spring fast you get the spring +constant that is 40% higher than if you + + align:start position:0% +constant that is 40% higher than if you + + + align:start position:0% +constant that is 40% higher than if you +act on the spring + + align:start position:0% +act on the spring + + + align:start position:0% +act on the spring +slow + + align:start position:0% +slow + + + align:start position:0% +slow +okay and these devices if you look up + + align:start position:0% +okay and these devices if you look up + + + align:start position:0% +okay and these devices if you look up +air Springs you see that there are uh + + align:start position:0% +air Springs you see that there are uh + + + align:start position:0% +air Springs you see that there are uh +it's an enormous business because as I + + align:start position:0% +it's an enormous business because as I + + + align:start position:0% +it's an enormous business because as I +said trains uh buses bicycles cars use + + align:start position:0% +said trains uh buses bicycles cars use + + + align:start position:0% +said trains uh buses bicycles cars use +spring constants combined also with The + + align:start position:0% +spring constants combined also with The + + + align:start position:0% +spring constants combined also with The +Dumping system to give you uh like um + + align:start position:0% +Dumping system to give you uh like um + + + align:start position:0% +Dumping system to give you uh like um +suspension systems that are uh allowed + + align:start position:0% +suspension systems that are uh allowed + + + align:start position:0% +suspension systems that are uh allowed +to absorb vibrations and make it uh more + + align:start position:0% +to absorb vibrations and make it uh more + + + align:start position:0% +to absorb vibrations and make it uh more +uh + + align:start position:0% +uh + + + align:start position:0% +uh +comfortable Okay so sorry if I went a + + align:start position:0% +comfortable Okay so sorry if I went a + + + align:start position:0% +comfortable Okay so sorry if I went a +little bit uh late \ No newline at end of file diff --git a/qY0ixUWJx0g.txt b/qY0ixUWJx0g.txt new file mode 100644 index 0000000000000000000000000000000000000000..236dbddedc7211993971e30a1f6f8f59c5ff3a72 --- /dev/null +++ b/qY0ixUWJx0g.txt @@ -0,0 +1,460 @@ +PROFESSOR: Hello and +welcome to the + +help session on pedigrees. + +Today, we will be working +out a problem together. + +If you have not yet had a chance +to work it on your own, + +please do so now, and +return to this video + +when you are done. + +Now that you've had a chance to +look at this problem, let's + +work it out together. + +The first part of this question +asks, what is the + +mode of inheritance that is +observed in this pedigree? + +So, we know that there are two +main types of modes of + +inheritance. + +It can either be dominant +or recessive. + +And from there it can either +be autosomal or X-linked. + +If a disease follows a dominant +inheritance pattern, + +generally, it must be present +in every generation. + +So here we notice that the +disease is present in the + +first generation, but it's not +present in anyone in the + +second generation. + +However, then it reappears +in the third generation. + +This suggests that the +disease is recessive. + +So now, do we think +this disease is + +autosomal or is it X-linked? + +So we look at the pedigree +again, and upon closer + +inspection, we notice +that the affected + +individuals are only males. + +This is a key characteristic +of an + +X-linked recessive disease. + +However, we're also given more +information that tells us that + +this individual here does not +carry an allele associated + +with the affected phenotype. + +This rules out the possibility +that this disease could be an + +autosomal recessive disease. + +Thus, the most likely mode of + +inheritance is X-linked recessive. + +Great, so moving on to the +second part of this problem, + +we are asked to determine the +genotypes of individuals + +number one and number three. + +So, if we look at this pedigree, +we know individual + +one is female and not affected +by the disease. + +Female individuals contain two +X chromosomes, and since she + +is not affected she must contain +at least one large R. + +So we'll call the allele +associated with the + +disease small r. + +We do not yet know what her +second X chromosome could be. + +It could be either another +large R or it + +could be a small r. + +And she also would still not +be affected by the disease. + +This male right here is affected +by the disease. + +So he must have an +X with a small r. + +Remember that males have one +X chromosome and one Y + +chromosome. + +So now, making our way down to +individual number three. + +Individual number three does +not have the disease and is + +female, so again, must have +two X chromosomes. + +One of the X chromosomes must +come from her father and the + +other from her mother. + +The only X chromosome that her +father can pass along to her + +is X small r. + +In order for her to not be +affected with the disease, her + +other X chromosome must +have a large R. + +She was able to get this +genotype with her mother + +having either of these +two genotypes. + +To make sure that both of these +genotypes are possible + +for this mother, we need to +examine her other children. + +Her son here is unaffected. + +So his genotype must have been +X large R, Y. It's possible + +for him to get this genotype +when the mother has either of + +these two genotypes. + +Similarly, this daughter could +be unaffected just as this + +daughter was unaffected. + +So the mother can have either +of these two genotypes. + +And we're unable to rule +out one of them. + +So let me just write up +the answer over here. + +All right, so far, so good. + +Next, we're asked to calculate +the probability that + +individual A is affected. + +Individual A is over here at +the bottom of the pedigree. + +In order for individual A to be +affected, she must have the + +following genotype. + +The only way for her to get two +little r's is for her to + +get one from her father and +one from her mother. + +We know this is possible because +her father is affected + +with the following genotype +of Y, X small r. + +Her mother is not affected. + +So for her to get this small +r, her mother must be a + +carrier for the disease, +and have the genotype X + +large R, X small r. + +So in order to determine the +probability that A is affected + +with both X small r's, we must +also know the probability that + +her mother was a carrier +for the disease. + +Let's call her mother +individual C. + +So, we know the genotypes +of her parents. + +Her mother was a carrier. + +And her father did not have the +disease, so his genotype + +was Y with X large R. So to +calculate the probability that + +individual C is a carrier for +the disease, let's go back + +over here and draw out +a Punnett square. + +On one side, we're going to +write the genotype of her + +father, which was Y because +he's a male. + +And then, he was not affected +by the disease, so it was X + +with a large R. Her mother +was a carrier. + +So she had one copy that was X +large R, and one copy that was + +x little r. + +So next, we want to know +the probability + +that she was a carrier. + +The only ways you can get +females is by looking at this + +top row here. + +So, for now, we're going to +ignore the bottom row. + +Of the two possible ways to +generate a female, only one of + +them is a carrier. + +So there's a 50% chance that +a female will be a carrier. + +So this is a 50% chance that +individual C is a carrier, + +which we will denote with this +half filled in circle. + +All right, so now that we know +the probability that C was a + +carrier, we need to know the +probability that her progeny, + +A, was affected with +the disease. + +Again, looking back over here, +her progeny needs to inherit + +the X small r from the +mother and the X + +small r from the father. + +So, once again, we can draw +a Punnett square to better + +understand this. + +Individual A's father +was indeed + +affected by the disease. + +So his genotype was X small r +and Y. Her mother, we just + +calculated the probability of +her being a carrier, so she is + +X large R, X small r. + +Now, we're looking at individual +A, who is a female, + +so again, we can ignore +the bottom row because + +this will be males. + +Here are the progeny +which are female. + +Of the two possibilities, only +the one on the right, X small + +r, X small r is affected +by the disease. + +So there is a 50% chance that +A will be affected by the + +disease given that her mother +is a carrier of the disease. + +Now to finish up this part of +the problem, we need to + +multiply these two probabilities +together because + +we're looking at the probability +that C is a + +carrier, and the probability +that A is + +affected with the disease. + +This gives us our answer +of one fourth. + +All right, so, moving on to the +last part of the problem. + +We need to calculate the +probability that B is affected + +with the disease. + +So this isn't that hard now that +we've drawn out all of + +these Punnett squares already. + +So, let's take a look back at +our pedigree over here. + +If B is going to be affected +with the disease, he must have + +the genotype Y, X +with a small r. + +He gets the Y from his father +and he must get this X with a + +small r from his mother. + +So again, we need the mother, +C, to be a carrier. + +So let's go back to our Punnett +squares over here. + +We know that there is +a 50% chance that + +individual C is a carrier. + +Now we need to look at +individual B being affected by + +the disease. + +So we can go ahead and fill +in the bottom part of this + +Punnett square. + +So of these two males, that are +possible, only one of them + +is affected with the disease. + +So again, there is a 50% +probability that that child + +will be affected with +the disease. + +Again, we are going +to multiply these + +probabilities together. + +So the probability that the +mother is a carrier, and that + +the son is affected with the +disease, gives us one quarter. + +That concludes our problem +on pedigrees. + +Thank you for joining us. \ No newline at end of file diff --git a/qw0pfuCu8q0.txt b/qw0pfuCu8q0.txt new file mode 100644 index 0000000000000000000000000000000000000000..246d2f33d405fe7812e3425d09ad52f2a4da00be --- /dev/null +++ b/qw0pfuCu8q0.txt @@ -0,0 +1,9091 @@ +align:start position:0% + +The following content is provided under + + align:start position:0% +The following content is provided under + + + align:start position:0% +The following content is provided under +a Creative Common license. Your support + + align:start position:0% +a Creative Common license. Your support + + + align:start position:0% +a Creative Common license. Your support +will help MIT Open Courseware continue + + align:start position:0% +will help MIT Open Courseware continue + + + align:start position:0% +will help MIT Open Courseware continue +to offer high-quality educational + + align:start position:0% +to offer high-quality educational + + + align:start position:0% +to offer high-quality educational +resources for free. To make a donation + + align:start position:0% +resources for free. To make a donation + + + align:start position:0% +resources for free. To make a donation +or to view additional materials from + + align:start position:0% +or to view additional materials from + + + align:start position:0% +or to view additional materials from +hundreds of MIT courses, visit MIT Open + + align:start position:0% +hundreds of MIT courses, visit MIT Open + + + align:start position:0% +hundreds of MIT courses, visit MIT Open +Courseware at ocw.mit.edu. + + align:start position:0% + + + + align:start position:0% + +Let's get started. Um, couple of + + align:start position:0% +Let's get started. Um, couple of + + + align:start position:0% +Let's get started. Um, couple of +announcements. + + align:start position:0% +announcements. + + + align:start position:0% +announcements. +Um reminder about the periodic table + + align:start position:0% +Um reminder about the periodic table + + + align:start position:0% +Um reminder about the periodic table +test which will uh be added next week on + + align:start position:0% +test which will uh be added next week on + + + align:start position:0% +test which will uh be added next week on +the 23rd. You can see the website if you + + align:start position:0% +the 23rd. You can see the website if you + + + align:start position:0% +the 23rd. You can see the website if you +want to download a a copy of this to + + align:start position:0% +want to download a a copy of this to + + + align:start position:0% +want to download a a copy of this to +practice on it. You're required only to + + align:start position:0% +practice on it. You're required only to + + + align:start position:0% +practice on it. You're required only to +put the one or two letter chemical + + align:start position:0% +put the one or two letter chemical + + + align:start position:0% +put the one or two letter chemical +abbreviation the symbol. Some people + + align:start position:0% +abbreviation the symbol. Some people + + + align:start position:0% +abbreviation the symbol. Some people +asked me if I wanted you to know the + + align:start position:0% +asked me if I wanted you to know the + + + align:start position:0% +asked me if I wanted you to know the +molecular weights and so on. And I um I + + align:start position:0% +molecular weights and so on. And I um I + + + align:start position:0% +molecular weights and so on. And I um I +thought that was a bit excessive. So, I + + align:start position:0% +thought that was a bit excessive. So, I + + + align:start position:0% +thought that was a bit excessive. So, I +think if you just know the symbols for + + align:start position:0% +think if you just know the symbols for + + + align:start position:0% +think if you just know the symbols for +the ones that are up there, that would + + align:start position:0% +the ones that are up there, that would + + + align:start position:0% +the ones that are up there, that would +be just that'd be just dandy. Um, here's + + align:start position:0% +be just that'd be just dandy. Um, here's + + + align:start position:0% +be just that'd be just dandy. Um, here's +the + + align:start position:0% +the + + + align:start position:0% +the +uh here's the lady's + + align:start position:0% +uh here's the lady's + + + align:start position:0% +uh here's the lady's +scarf. Very hot. Black. See trim lines + + align:start position:0% +scarf. Very hot. Black. See trim lines + + + align:start position:0% +scarf. Very hot. Black. See trim lines +and uh blue and gold. And it's got + + align:start position:0% +and uh blue and gold. And it's got + + + align:start position:0% +and uh blue and gold. And it's got +elements on it. Very hot. Very + + align:start position:0% +elements on it. Very hot. Very + + + align:start position:0% +elements on it. Very hot. Very +hot. There's a neck tie. Comparable + + align:start position:0% +hot. There's a neck tie. Comparable + + + align:start position:0% +hot. There's a neck tie. Comparable +fabric, comparable pattern. It's not + + align:start position:0% +fabric, comparable pattern. It's not + + + align:start position:0% +fabric, comparable pattern. It's not +geeky. This is very hot. + + align:start position:0% +geeky. This is very hot. + + + align:start position:0% +geeky. This is very hot. +You need you need this. You need this. + + align:start position:0% +You need you need this. You need this. + + + align:start position:0% +You need you need this. You need this. +Okay, let's get on with the lesson. Last + + align:start position:0% +Okay, let's get on with the lesson. Last + + + align:start position:0% +Okay, let's get on with the lesson. Last +day we looked at uh uh Rutherford Guyger + + align:start position:0% +day we looked at uh uh Rutherford Guyger + + + align:start position:0% +day we looked at uh uh Rutherford Guyger +Marsden and the experiment that they + + align:start position:0% +Marsden and the experiment that they + + + align:start position:0% +Marsden and the experiment that they +conducted on the gold foil and out of + + align:start position:0% +conducted on the gold foil and out of + + + align:start position:0% +conducted on the gold foil and out of +that came the uh recognition that + + align:start position:0% +that came the uh recognition that + + + align:start position:0% +that came the uh recognition that +Thompson's plum pudding model uh is not + + align:start position:0% +Thompson's plum pudding model uh is not + + + align:start position:0% +Thompson's plum pudding model uh is not +sustainable in the light of this + + align:start position:0% +sustainable in the light of this + + + align:start position:0% +sustainable in the light of this +evidence and instead Rutherford proposed + + align:start position:0% +evidence and instead Rutherford proposed + + + align:start position:0% +evidence and instead Rutherford proposed +something akin to a planetary system. + + align:start position:0% +something akin to a planetary system. + + + align:start position:0% +something akin to a planetary system. +And there's something uh I'd like you to + + align:start position:0% +And there's something uh I'd like you to + + + align:start position:0% +And there's something uh I'd like you to +be tuned into here. You know, people to + + align:start position:0% +be tuned into here. You know, people to + + + align:start position:0% +be tuned into here. You know, people to +this day are looking for a theory of + + align:start position:0% +this day are looking for a theory of + + + align:start position:0% +this day are looking for a theory of +everything. And there was something very + + align:start position:0% +everything. And there was something very + + + align:start position:0% +everything. And there was something very +appealing about the notion that the + + align:start position:0% +appealing about the notion that the + + + align:start position:0% +appealing about the notion that the +rules that govern the motion of heavenly + + align:start position:0% +rules that govern the motion of heavenly + + + align:start position:0% +rules that govern the motion of heavenly +bodies might be applicable down at uh + + align:start position:0% +bodies might be applicable down at uh + + + align:start position:0% +bodies might be applicable down at uh +atomic dimensions. So this is very uh + + align:start position:0% +atomic dimensions. So this is very uh + + + align:start position:0% +atomic dimensions. So this is very uh +you know cosmic you know there's a + + align:start position:0% +you know cosmic you know there's a + + + align:start position:0% +you know cosmic you know there's a +gestalt here. So uh we ended the day + + align:start position:0% +gestalt here. So uh we ended the day + + + align:start position:0% +gestalt here. So uh we ended the day +with Boore's model of the atom which + + align:start position:0% +with Boore's model of the atom which + + + align:start position:0% +with Boore's model of the atom which +derived from the conceptualization of + + align:start position:0% +derived from the conceptualization of + + + align:start position:0% +derived from the conceptualization of +Rutherford and this uh model is + + align:start position:0% +Rutherford and this uh model is + + + align:start position:0% +Rutherford and this uh model is +quantitative and I think I put up the + + align:start position:0% +quantitative and I think I put up the + + + align:start position:0% +quantitative and I think I put up the +postulates and what I'm going to do + + align:start position:0% +postulates and what I'm going to do + + + align:start position:0% +postulates and what I'm going to do +today is is go in some detail through + + align:start position:0% +today is is go in some detail through + + + align:start position:0% +today is is go in some detail through +the bore model. So let's do that. Um so + + align:start position:0% +the bore model. So let's do that. Um so + + + align:start position:0% +the bore model. So let's do that. Um so +I'm going to put up the uh most + + align:start position:0% +I'm going to put up the uh most + + + align:start position:0% +I'm going to put up the uh most +primitive version. It's a one electron + + align:start position:0% +primitive version. It's a one electron + + + align:start position:0% +primitive version. It's a one electron +atom. So it's got a nucleus at the + + align:start position:0% +atom. So it's got a nucleus at the + + + align:start position:0% +atom. So it's got a nucleus at the +center charged positively. This is where + + align:start position:0% +center charged positively. This is where + + + align:start position:0% +center charged positively. This is where +most of the mass resides and the + + align:start position:0% +most of the mass resides and the + + + align:start position:0% +most of the mass resides and the +positive charge resides. And orbiting + + align:start position:0% +positive charge resides. And orbiting + + + align:start position:0% +positive charge resides. And orbiting +around this is a lone electron out at + + align:start position:0% +around this is a lone electron out at + + + align:start position:0% +around this is a lone electron out at +some distance r. And I don't have to + + align:start position:0% +some distance r. And I don't have to + + + align:start position:0% +some distance r. And I don't have to +worry about these relative dimensions + + align:start position:0% +worry about these relative dimensions + + + align:start position:0% +worry about these relative dimensions +because we know from Marsen's + + align:start position:0% +because we know from Marsen's + + + align:start position:0% +because we know from Marsen's +calculations that on a on the length + + align:start position:0% +calculations that on a on the length + + + align:start position:0% +calculations that on a on the length +scale that I've shown here, these would + + align:start position:0% +scale that I've shown here, these would + + + align:start position:0% +scale that I've shown here, these would +be just tiny little dots. It's about + + align:start position:0% +be just tiny little dots. It's about + + + align:start position:0% +be just tiny little dots. It's about +10,000 to one. ratio of the nuclear + + align:start position:0% +10,000 to one. ratio of the nuclear + + + align:start position:0% +10,000 to one. ratio of the nuclear +dimension to the uh entire atomic + + align:start position:0% +dimension to the uh entire atomic + + + align:start position:0% +dimension to the uh entire atomic +dimension. And so we have a positive + + align:start position:0% +dimension. And so we have a positive + + + align:start position:0% +dimension. And so we have a positive +charge in the nucleus which is given by + + align:start position:0% +charge in the nucleus which is given by + + + align:start position:0% +charge in the nucleus which is given by +the number of protons. This would be a + + align:start position:0% +the number of protons. This would be a + + + align:start position:0% +the number of protons. This would be a +one electron atom. It could be hydrogen. + + align:start position:0% +one electron atom. It could be hydrogen. + + + align:start position:0% +one electron atom. It could be hydrogen. +It could be helium plus. It could be + + align:start position:0% +It could be helium plus. It could be + + + align:start position:0% +It could be helium plus. It could be +lithium double plus and so on. These are + + align:start position:0% +lithium double plus and so on. These are + + + align:start position:0% +lithium double plus and so on. These are +all one electron atoms and they're + + align:start position:0% +all one electron atoms and they're + + + align:start position:0% +all one electron atoms and they're +gas. It's gas single atom. So this will + + align:start position:0% +gas. It's gas single atom. So this will + + + align:start position:0% +gas. It's gas single atom. So this will +be Z times the elementary charge. + + align:start position:0% +be Z times the elementary charge. + + + align:start position:0% +be Z times the elementary charge. +Remember E represents the elementary + + align:start position:0% +Remember E represents the elementary + + + align:start position:0% +Remember E represents the elementary +charge not the charge on the electron. + + align:start position:0% +charge not the charge on the electron. + + + align:start position:0% +charge not the charge on the electron. +The charge on the electron is minus E. + + align:start position:0% +The charge on the electron is minus E. + + + align:start position:0% +The charge on the electron is minus E. +So this is Z * E in the center. And out + + align:start position:0% +So this is Z * E in the center. And out + + + align:start position:0% +So this is Z * E in the center. And out +here we have the charge on the electron + + align:start position:0% +here we have the charge on the electron + + + align:start position:0% +here we have the charge on the electron +as simply equal to E. So I'm going to + + align:start position:0% +as simply equal to E. So I'm going to + + + align:start position:0% +as simply equal to E. So I'm going to +highlight this by calling this Q1. + + align:start position:0% +highlight this by calling this Q1. + + + align:start position:0% +highlight this by calling this Q1. +Lowerase Q being the charge here on the + + align:start position:0% +Lowerase Q being the charge here on the + + + align:start position:0% +Lowerase Q being the charge here on the +uh nucleus and lowercase Q sub 2 is the + + align:start position:0% +uh nucleus and lowercase Q sub 2 is the + + + align:start position:0% +uh nucleus and lowercase Q sub 2 is the +charge on the electron and that is given + + align:start position:0% +charge on the electron and that is given + + + align:start position:0% +charge on the electron and that is given +by minus E minus E and um so the the + + align:start position:0% +by minus E minus E and um so the the + + + align:start position:0% +by minus E minus E and um so the the +other thing that we consider is the + + align:start position:0% +other thing that we consider is the + + + align:start position:0% +other thing that we consider is the +nucleuses being stationary. So we have + + align:start position:0% +nucleuses being stationary. So we have + + + align:start position:0% +nucleuses being stationary. So we have +an orbiting electron but a stationary + + align:start position:0% +an orbiting electron but a stationary + + + align:start position:0% +an orbiting electron but a stationary +nucleus. And Rutherford, whom I've + + align:start position:0% +nucleus. And Rutherford, whom I've + + + align:start position:0% +nucleus. And Rutherford, whom I've +already described to you as being uh a + + align:start position:0% +already described to you as being uh a + + + align:start position:0% +already described to you as being uh a +little bit colorful in his language, he + + align:start position:0% +little bit colorful in his language, he + + + align:start position:0% +little bit colorful in his language, he +backed up bore on this and he says, you + + align:start position:0% +backed up bore on this and he says, you + + + align:start position:0% +backed up bore on this and he says, you +know, when an elephant has fleas, it's + + align:start position:0% +know, when an elephant has fleas, it's + + + align:start position:0% +know, when an elephant has fleas, it's +the fleas that do the jumping. So that's + + align:start position:0% +the fleas that do the jumping. So that's + + + align:start position:0% +the fleas that do the jumping. So that's +why we don't worry about the motion of + + align:start position:0% +why we don't worry about the motion of + + + align:start position:0% +why we don't worry about the motion of +the nucleus because the ratio of masses + + align:start position:0% +the nucleus because the ratio of masses + + + align:start position:0% +the nucleus because the ratio of masses +is about 2,000 to1. So what I'm going to + + align:start position:0% +is about 2,000 to1. So what I'm going to + + + align:start position:0% +is about 2,000 to1. So what I'm going to +do is use these postulates and go + + align:start position:0% +do is use these postulates and go + + + align:start position:0% +do is use these postulates and go +through the basis for the bore model. + + align:start position:0% +through the basis for the bore model. + + + align:start position:0% +through the basis for the bore model. +The first thing we're going to do is uh + + align:start position:0% +The first thing we're going to do is uh + + + align:start position:0% +The first thing we're going to do is uh +describe the energy of the system. So + + align:start position:0% +describe the energy of the system. So + + + align:start position:0% +describe the energy of the system. So +the total energy of the system which + + align:start position:0% +the total energy of the system which + + + align:start position:0% +the total energy of the system which +we're going to get from postulate number + + align:start position:0% +we're going to get from postulate number + + + align:start position:0% +we're going to get from postulate number +four which says the energy of the + + align:start position:0% +four which says the energy of the + + + align:start position:0% +four which says the energy of the +electron which is the energy of the + + align:start position:0% +electron which is the energy of the + + + align:start position:0% +electron which is the energy of the +system is the sum of the kinetic and the + + align:start position:0% +system is the sum of the kinetic and the + + + align:start position:0% +system is the sum of the kinetic and the +potential energy. So let's write that. + + align:start position:0% +potential energy. So let's write that. + + + align:start position:0% +potential energy. So let's write that. +And I as I've reminded you at the end of + + align:start position:0% +And I as I've reminded you at the end of + + + align:start position:0% +And I as I've reminded you at the end of +last day the only reason I'm doing this + + align:start position:0% +last day the only reason I'm doing this + + + align:start position:0% +last day the only reason I'm doing this +for you right now is I want to elucidate + + align:start position:0% +for you right now is I want to elucidate + + + align:start position:0% +for you right now is I want to elucidate +the principles. It's not because I favor + + align:start position:0% +the principles. It's not because I favor + + + align:start position:0% +the principles. It's not because I favor +derivations in class. I've been teaching + + align:start position:0% +derivations in class. I've been teaching + + + align:start position:0% +derivations in class. I've been teaching +long enough to know that doing + + align:start position:0% +long enough to know that doing + + + align:start position:0% +long enough to know that doing +derivations in class is equivalent + + align:start position:0% +derivations in class is equivalent + + + align:start position:0% +derivations in class is equivalent +pouring ice water on the proceedings. So + + align:start position:0% +pouring ice water on the proceedings. So + + + align:start position:0% +pouring ice water on the proceedings. So +this I do this sparingly. So it's a + + align:start position:0% +this I do this sparingly. So it's a + + + align:start position:0% +this I do this sparingly. So it's a +Newtonian system from the mechanical + + align:start position:0% +Newtonian system from the mechanical + + + align:start position:0% +Newtonian system from the mechanical +standpoint. So this is going to be a + + align:start position:0% +standpoint. So this is going to be a + + + align:start position:0% +standpoint. So this is going to be a +half mv squared where this is the mass + + align:start position:0% +half mv squared where this is the mass + + + align:start position:0% +half mv squared where this is the mass +of the + + align:start position:0% +of the + + + align:start position:0% +of the +electron and then the potential energy + + align:start position:0% +electron and then the potential energy + + + align:start position:0% +electron and then the potential energy +the energy is stored here due to the + + align:start position:0% +the energy is stored here due to the + + + align:start position:0% +the energy is stored here due to the +kulomic force of attraction between the + + align:start position:0% +kulomic force of attraction between the + + + align:start position:0% +kulomic force of attraction between the +electron and the nucleus. So in the most + + align:start position:0% +electron and the nucleus. So in the most + + + align:start position:0% +electron and the nucleus. So in the most +general form, Kulum's law is the product + + align:start position:0% +general form, Kulum's law is the product + + + align:start position:0% +general form, Kulum's law is the product +of the charges Q1 Q2 divided by their + + align:start position:0% +of the charges Q1 Q2 divided by their + + + align:start position:0% +of the charges Q1 Q2 divided by their +separation which is R. And in order to + + align:start position:0% +separation which is R. And in order to + + + align:start position:0% +separation which is R. And in order to +rationalize electrostatic units with + + align:start position:0% +rationalize electrostatic units with + + + align:start position:0% +rationalize electrostatic units with +mechanical units, we have to put a + + align:start position:0% +mechanical units, we have to put a + + + align:start position:0% +mechanical units, we have to put a +factor in here. Otherwise, the units + + align:start position:0% +factor in here. Otherwise, the units + + + align:start position:0% +factor in here. Otherwise, the units +that come out of this calculation won't + + align:start position:0% +that come out of this calculation won't + + + align:start position:0% +that come out of this calculation won't +dovetail with the units that come out of + + align:start position:0% +dovetail with the units that come out of + + + align:start position:0% +dovetail with the units that come out of +this calculation. And that factor is 4 + + align:start position:0% +this calculation. And that factor is 4 + + + align:start position:0% +this calculation. And that factor is 4 +pi time epsilon0. epsilon0 is the + + align:start position:0% +pi time epsilon0. epsilon0 is the + + + align:start position:0% +pi time epsilon0. epsilon0 is the +permitivity of vacuum. And now we can + + align:start position:0% +permitivity of vacuum. And now we can + + + align:start position:0% +permitivity of vacuum. And now we can +plug in Q1 and Q2. We know that we've + + align:start position:0% +plug in Q1 and Q2. We know that we've + + + align:start position:0% +plug in Q1 and Q2. We know that we've +got half MV + + align:start position:0% +got half MV + + + align:start position:0% +got half MV +squared. And then Q1 is plus QE. Q2 is + + align:start position:0% +squared. And then Q1 is plus QE. Q2 is + + + align:start position:0% +squared. And then Q1 is plus QE. Q2 is +minus E. So then that will give us a net + + align:start position:0% +minus E. So then that will give us a net + + + align:start position:0% +minus E. So then that will give us a net +minus Z * the square of the elementary + + align:start position:0% +minus Z * the square of the elementary + + + align:start position:0% +minus Z * the square of the elementary +charge over 4 pi epsilon0 R. And I'm + + align:start position:0% +charge over 4 pi epsilon0 R. And I'm + + + align:start position:0% +charge over 4 pi epsilon0 R. And I'm +going to label this as equation one. And + + align:start position:0% +going to label this as equation one. And + + + align:start position:0% +going to label this as equation one. And +um so this is really this is a + + align:start position:0% +um so this is really this is a + + + align:start position:0% +um so this is really this is a +mechanical term if you like mechanical + + align:start position:0% +mechanical term if you like mechanical + + + align:start position:0% +mechanical term if you like mechanical +and this is + + align:start position:0% +and this is + + + align:start position:0% +and this is +electrostatic or + + align:start position:0% +electrostatic or + + + align:start position:0% +electrostatic or +kombic use different words for that. And + + align:start position:0% +kombic use different words for that. And + + + align:start position:0% +kombic use different words for that. And +where do we find these things? We can + + align:start position:0% +where do we find these things? We can + + + align:start position:0% +where do we find these things? We can +find values of all of these. If you look + + align:start position:0% +find values of all of these. If you look + + + align:start position:0% +find values of all of these. If you look +at your table of constants um if you + + align:start position:0% +at your table of constants um if you + + + align:start position:0% +at your table of constants um if you +look at your table of constants this is + + align:start position:0% +look at your table of constants this is + + + align:start position:0% +look at your table of constants this is +the table of constants in its entirety. + + align:start position:0% +the table of constants in its entirety. + + + align:start position:0% +the table of constants in its entirety. +But if you look up really close, there's + + align:start position:0% +But if you look up really close, there's + + + align:start position:0% +But if you look up really close, there's +uh the elementary charge E. There's the + + align:start position:0% +uh the elementary charge E. There's the + + + align:start position:0% +uh the elementary charge E. There's the +mass of the electron. All of these are + + align:start position:0% +mass of the electron. All of these are + + + align:start position:0% +mass of the electron. All of these are +given here. This is 9.11 time 10 - 31 kg + + align:start position:0% +given here. This is 9.11 time 10 - 31 kg + + + align:start position:0% +given here. This is 9.11 time 10 - 31 kg +is 1.6 * 10 - 19 kum. There's the + + align:start position:0% +is 1.6 * 10 - 19 kum. There's the + + + align:start position:0% +is 1.6 * 10 - 19 kum. There's the +permitivity of vacuum. It's all up + + align:start position:0% +permitivity of vacuum. It's all up + + + align:start position:0% +permitivity of vacuum. It's all up +there. Okay. So you have these at your + + align:start position:0% +there. Okay. So you have these at your + + + align:start position:0% +there. Okay. So you have these at your +uh disposal. Um so now let's do the next + + align:start position:0% +uh disposal. Um so now let's do the next + + + align:start position:0% +uh disposal. Um so now let's do the next +uh do the next step which is a force + + align:start position:0% +uh do the next step which is a force + + + align:start position:0% +uh do the next step which is a force +balance that comes out of postulate 3. + + align:start position:0% +balance that comes out of postulate 3. + + + align:start position:0% +balance that comes out of postulate 3. +Out of postulate 3 it says Newtonian + + align:start position:0% +Out of postulate 3 it says Newtonian + + + align:start position:0% +Out of postulate 3 it says Newtonian +mechanics applicable. So let's put a + + align:start position:0% +mechanics applicable. So let's put a + + + align:start position:0% +mechanics applicable. So let's put a +force balance. So I'm going to say if + + align:start position:0% +force balance. So I'm going to say if + + + align:start position:0% +force balance. So I'm going to say if +that electron is to stay in its orbit + + align:start position:0% +that electron is to stay in its orbit + + + align:start position:0% +that electron is to stay in its orbit +that is to say it doesn't flee the atom + + align:start position:0% +that is to say it doesn't flee the atom + + + align:start position:0% +that is to say it doesn't flee the atom +it doesn't collapse into the nucleus + + align:start position:0% +it doesn't collapse into the nucleus + + + align:start position:0% +it doesn't collapse into the nucleus +then the sum of the forces on the + + align:start position:0% +then the sum of the forces on the + + + align:start position:0% +then the sum of the forces on the +electron must be zero. No net force. No + + align:start position:0% +electron must be zero. No net force. No + + + align:start position:0% +electron must be zero. No net force. No +net force. And so that'll be the sum of + + align:start position:0% +net force. And so that'll be the sum of + + + align:start position:0% +net force. And so that'll be the sum of +a of a + + align:start position:0% +a of a + + + align:start position:0% +a of a +dynamic force plus a electrostatic or + + align:start position:0% +dynamic force plus a electrostatic or + + + align:start position:0% +dynamic force plus a electrostatic or +just to be pluralistic in our language + + align:start position:0% +just to be pluralistic in our language + + + align:start position:0% +just to be pluralistic in our language +kulomic force. And so you know from your + + align:start position:0% +kulomic force. And so you know from your + + + align:start position:0% +kulomic force. And so you know from your +Newtonian mechanics as you're learning + + align:start position:0% +Newtonian mechanics as you're learning + + + align:start position:0% +Newtonian mechanics as you're learning +in 801 the dynamic force here is m v ^2 + + align:start position:0% +in 801 the dynamic force here is m v ^2 + + + align:start position:0% +in 801 the dynamic force here is m v ^2 +/ r again m is the mass of the electron. + + align:start position:0% +/ r again m is the mass of the electron. + + + align:start position:0% +/ r again m is the mass of the electron. +And now the force in its most general + + align:start position:0% +And now the force in its most general + + + align:start position:0% +And now the force in its most general +term is Q1 Q2 over 4 piepsilon0 which is + + align:start position:0% +term is Q1 Q2 over 4 piepsilon0 which is + + + align:start position:0% +term is Q1 Q2 over 4 piepsilon0 which is +the conversion factor R2. Force goes as + + align:start position:0% +the conversion factor R2. Force goes as + + + align:start position:0% +the conversion factor R2. Force goes as +1 / R squared. Energy goes as 1 / R. And + + align:start position:0% +1 / R squared. Energy goes as 1 / R. And + + + align:start position:0% +1 / R squared. Energy goes as 1 / R. And +if you ever get confused the way to + + align:start position:0% +if you ever get confused the way to + + + align:start position:0% +if you ever get confused the way to +remember these is that you know that uh + + align:start position:0% +remember these is that you know that uh + + + align:start position:0% +remember these is that you know that uh +energy is the integral of a force moving + + align:start position:0% +energy is the integral of a force moving + + + align:start position:0% +energy is the integral of a force moving +through a distance. + + align:start position:0% +through a distance. + + + align:start position:0% +through a distance. +Right? Energy energy is the integral of + + align:start position:0% +Right? Energy energy is the integral of + + + align:start position:0% +Right? Energy energy is the integral of +force moving through a distance. So the + + align:start position:0% +force moving through a distance. So the + + + align:start position:0% +force moving through a distance. So the +integral of 1 / r 2 gives you 1 / r. If + + align:start position:0% +integral of 1 / r 2 gives you 1 / r. If + + + align:start position:0% +integral of 1 / r 2 gives you 1 / r. If +you get them backwards, you'll integrate + + align:start position:0% +you get them backwards, you'll integrate + + + align:start position:0% +you get them backwards, you'll integrate +one over r, you'll get log r. That makes + + align:start position:0% +one over r, you'll get log r. That makes + + + align:start position:0% +one over r, you'll get log r. That makes +no + + align:start position:0% +no + + + align:start position:0% +no +sense. So there we are. And uh we plug + + align:start position:0% +sense. So there we are. And uh we plug + + + align:start position:0% +sense. So there we are. And uh we plug +in our values and we end up with m v ^2 + + align:start position:0% +in our values and we end up with m v ^2 + + + align:start position:0% +in our values and we end up with m v ^2 +/ r minus z e^2 over 4 pi epsilon0 r 2. + + align:start position:0% +/ r minus z e^2 over 4 pi epsilon0 r 2. + + + align:start position:0% +/ r minus z e^2 over 4 pi epsilon0 r 2. +And I'm going to call this equation two. + + align:start position:0% +And I'm going to call this equation two. + + + align:start position:0% +And I'm going to call this equation two. +So that's our force balance. And then + + align:start position:0% +So that's our force balance. And then + + + align:start position:0% +So that's our force balance. And then +for the for the next piece of + + align:start position:0% +for the for the next piece of + + + align:start position:0% +for the for the next piece of +information, uh I'm going to go to + + align:start position:0% +information, uh I'm going to go to + + + align:start position:0% +information, uh I'm going to go to +postulate number five. And postulate + + align:start position:0% +postulate number five. And postulate + + + align:start position:0% +postulate number five. And postulate +number five is some of Boore's uh early + + align:start position:0% +number five is some of Boore's uh early + + + align:start position:0% +number five is some of Boore's uh early +genius. Boore says that the energy is + + align:start position:0% +genius. Boore says that the energy is + + + align:start position:0% +genius. Boore says that the energy is +quantized through its angular momentum. + + align:start position:0% +quantized through its angular momentum. + + + align:start position:0% +quantized through its angular momentum. +He's talking about the energy of an + + align:start position:0% +He's talking about the energy of an + + + align:start position:0% +He's talking about the energy of an +electron. No one until this time had + + align:start position:0% +electron. No one until this time had + + + align:start position:0% +electron. No one until this time had +suggested that a system would be + + align:start position:0% +suggested that a system would be + + + align:start position:0% +suggested that a system would be +subjected to + + align:start position:0% +subjected to + + + align:start position:0% +subjected to +quantization except for light. Plunk had + + align:start position:0% +quantization except for light. Plunk had + + + align:start position:0% +quantization except for light. Plunk had +already annunciated back in 1900 this E + + align:start position:0% +already annunciated back in 1900 this E + + + align:start position:0% +already annunciated back in 1900 this E +equals H new. In other words, that the + + align:start position:0% +equals H new. In other words, that the + + + align:start position:0% +equals H new. In other words, that the +photon has a quantum of energy H new. So + + align:start position:0% +photon has a quantum of energy H new. So + + + align:start position:0% +photon has a quantum of energy H new. So +quantization of radiation was already + + align:start position:0% +quantization of radiation was already + + + align:start position:0% +quantization of radiation was already +established as of about 1900. But no one + + align:start position:0% +established as of about 1900. But no one + + + align:start position:0% +established as of about 1900. But no one +dared no one dared say we've got this + + align:start position:0% +dared no one dared say we've got this + + + align:start position:0% +dared no one dared say we've got this +little planetary model. I've got an + + align:start position:0% +little planetary model. I've got an + + + align:start position:0% +little planetary model. I've got an +electron orbiting a central nucleus and + + align:start position:0% +electron orbiting a central nucleus and + + + align:start position:0% +electron orbiting a central nucleus and +I'm going to endow that electron with + + align:start position:0% +I'm going to endow that electron with + + + align:start position:0% +I'm going to endow that electron with +quantiz states. That was a big leap. And + + align:start position:0% +quantiz states. That was a big leap. And + + + align:start position:0% +quantiz states. That was a big leap. And +that was bore in postulate 5. So + + align:start position:0% +that was bore in postulate 5. So + + + align:start position:0% +that was bore in postulate 5. So +postulate 5 I'm just going to reproduce. + + align:start position:0% +postulate 5 I'm just going to reproduce. + + + align:start position:0% +postulate 5 I'm just going to reproduce. +So that's mvr which is its angular + + align:start position:0% +So that's mvr which is its angular + + + align:start position:0% +So that's mvr which is its angular +momentum does not take continuous + + align:start position:0% +momentum does not take continuous + + + align:start position:0% +momentum does not take continuous +values. It takes discrete values + + align:start position:0% +values. It takes discrete values + + + align:start position:0% +values. It takes discrete values +multiples of some integer n and the + + align:start position:0% +multiples of some integer n and the + + + align:start position:0% +multiples of some integer n and the +multiplication factor is the ratio of + + align:start position:0% +multiplication factor is the ratio of + + + align:start position:0% +multiplication factor is the ratio of +the plank constant divided by 2 pi where + + align:start position:0% +the plank constant divided by 2 pi where + + + align:start position:0% +the plank constant divided by 2 pi where +n takes one two three and so on. And I'm + + align:start position:0% +n takes one two three and so on. And I'm + + + align:start position:0% +n takes one two three and so on. And I'm +going to call this one equation three. + + align:start position:0% +going to call this one equation three. + + + align:start position:0% +going to call this one equation three. +So, I've got three equations and three + + align:start position:0% +So, I've got three equations and three + + + align:start position:0% +So, I've got three equations and three +unknowns. And I'm not going to take the + + align:start position:0% +unknowns. And I'm not going to take the + + + align:start position:0% +unknowns. And I'm not going to take the +time to solve it because I think that's + + align:start position:0% +time to solve it because I think that's + + + align:start position:0% +time to solve it because I think that's +a waste of class time. But those are the + + align:start position:0% +a waste of class time. But those are the + + + align:start position:0% +a waste of class time. But those are the +three unknowns. The radius of the orbit, + + align:start position:0% +three unknowns. The radius of the orbit, + + + align:start position:0% +three unknowns. The radius of the orbit, +the energy of the + + align:start position:0% +the energy of the + + + align:start position:0% +the energy of the +system, and the velocity of the + + align:start position:0% +system, and the velocity of the + + + align:start position:0% +system, and the velocity of the +electron. So, I'm just going to present + + align:start position:0% +electron. So, I'm just going to present + + + align:start position:0% +electron. So, I'm just going to present +you the solutions. Let's look first of + + align:start position:0% +you the solutions. Let's look first of + + + align:start position:0% +you the solutions. Let's look first of +all at the radius of the orbit. If you + + align:start position:0% +all at the radius of the orbit. If you + + + align:start position:0% +all at the radius of the orbit. If you +solve for r, you'll end up with this. + + align:start position:0% +solve for r, you'll end up with this. + + + align:start position:0% +solve for r, you'll end up with this. +This is the um permitivity of vacuum + + align:start position:0% +This is the um permitivity of vacuum + + + align:start position:0% +This is the um permitivity of vacuum +square of the plant constant time pi + + align:start position:0% +square of the plant constant time pi + + + align:start position:0% +square of the plant constant time pi +mass of the electron. I'm going to stop + + align:start position:0% +mass of the electron. I'm going to stop + + + align:start position:0% +mass of the electron. I'm going to stop +putting subscript e. It's the mass of + + align:start position:0% +putting subscript e. It's the mass of + + + align:start position:0% +putting subscript e. It's the mass of +the electron times the square of the + + align:start position:0% +the electron times the square of the + + + align:start position:0% +the electron times the square of the +elementary charge times n^2 + + align:start position:0% +elementary charge times n^2 + + + align:start position:0% +elementary charge times n^2 +over z. Z is the proton number of + + align:start position:0% +over z. Z is the proton number of + + + align:start position:0% +over z. Z is the proton number of +protons in the nucleus. So what do I + + align:start position:0% +protons in the nucleus. So what do I + + + align:start position:0% +protons in the nucleus. So what do I +see? I see that r takes on discrete + + align:start position:0% +see? I see that r takes on discrete + + + align:start position:0% +see? I see that r takes on discrete +values. R is a function of N takes on + + align:start position:0% +values. R is a function of N takes on + + + align:start position:0% +values. R is a function of N takes on +discrete values and in fact it's a the + + align:start position:0% +discrete values and in fact it's a the + + + align:start position:0% +discrete values and in fact it's a the +the functionality is that of the square + + align:start position:0% +the functionality is that of the square + + + align:start position:0% +the functionality is that of the square +of this number times a constant times a + + align:start position:0% +of this number times a constant times a + + + align:start position:0% +of this number times a constant times a +constant. So this tells us that the + + align:start position:0% +constant. So this tells us that the + + + align:start position:0% +constant. So this tells us that the +radius of the electron orbit first of + + align:start position:0% +radius of the electron orbit first of + + + align:start position:0% +radius of the electron orbit first of +all there is more than one radius + + align:start position:0% +all there is more than one radius + + + align:start position:0% +all there is more than one radius +there's a plurality of values secondly + + align:start position:0% +there's a plurality of values secondly + + + align:start position:0% +there's a plurality of values secondly +that those values are discrete they're + + align:start position:0% +that those values are discrete they're + + + align:start position:0% +that those values are discrete they're +quantized and third it's nonlinear so if + + align:start position:0% +quantized and third it's nonlinear so if + + + align:start position:0% +quantized and third it's nonlinear so if +I look at something that goes as uh n + + align:start position:0% +I look at something that goes as uh n + + + align:start position:0% +I look at something that goes as uh n +squar if this is the edge of the nucleus + + align:start position:0% +squar if this is the edge of the nucleus + + + align:start position:0% +squar if this is the edge of the nucleus +here and if this is r1 it says when n + + align:start position:0% +here and if this is r1 it says when n + + + align:start position:0% +here and if this is r1 it says when n +goes to two the radius goes to four so + + align:start position:0% +goes to two the radius goes to four so + + + align:start position:0% +goes to two the radius goes to four so +this is let's say this is r1 this is r2 + + align:start position:0% +this is let's say this is r1 this is r2 + + + align:start position:0% +this is let's say this is r1 this is r2 +and then this will be R3 and this will + + align:start position:0% +and then this will be R3 and this will + + + align:start position:0% +and then this will be R3 and this will +be R4 and even that's not the scale. + + align:start position:0% +be R4 and even that's not the scale. + + + align:start position:0% +be R4 and even that's not the scale. +Okay, so the the higher the N number the + + align:start position:0% +Okay, so the the higher the N number the + + + align:start position:0% +Okay, so the the higher the N number the +the greater the radius by uh by far and + + align:start position:0% +the greater the radius by uh by far and + + + align:start position:0% +the greater the radius by uh by far and +this applies to all one electron atoms. + + align:start position:0% +this applies to all one electron atoms. + + + align:start position:0% +this applies to all one electron atoms. +All one electron atoms. Um so let's look + + align:start position:0% +All one electron atoms. Um so let's look + + + align:start position:0% +All one electron atoms. Um so let's look +at the simplest case. Suppose we look at + + align:start position:0% +at the simplest case. Suppose we look at + + + align:start position:0% +at the simplest case. Suppose we look at +elemental hydrogen. So in case of + + align:start position:0% +elemental hydrogen. So in case of + + + align:start position:0% +elemental hydrogen. So in case of +elemental hydrogen Z will equal one. And + + align:start position:0% +elemental hydrogen Z will equal one. And + + + align:start position:0% +elemental hydrogen Z will equal one. And +then let's look at the lowest orbit n= + + align:start position:0% +then let's look at the lowest orbit n= + + + align:start position:0% +then let's look at the lowest orbit n= +1. That's the electron in its lowest + + align:start position:0% +1. That's the electron in its lowest + + + align:start position:0% +1. That's the electron in its lowest +orbit to the nucleus of atomic hydrogen. + + align:start position:0% +orbit to the nucleus of atomic hydrogen. + + + align:start position:0% +orbit to the nucleus of atomic hydrogen. +And this lowest orbit is termed the + + align:start position:0% +And this lowest orbit is termed the + + + align:start position:0% +And this lowest orbit is termed the +ground state. The ground + + align:start position:0% +ground state. The ground + + + align:start position:0% +ground state. The ground +state first floor. So if we put one here + + align:start position:0% +state first floor. So if we put one here + + + align:start position:0% +state first floor. So if we put one here +and one here, the value is simply given + + align:start position:0% +and one here, the value is simply given + + + align:start position:0% +and one here, the value is simply given +by this constant. And if you evaluate + + align:start position:0% +by this constant. And if you evaluate + + + align:start position:0% +by this constant. And if you evaluate +the constant you get that r1 is equal to + + align:start position:0% +the constant you get that r1 is equal to + + + align:start position:0% +the constant you get that r1 is equal to +5.29 + + align:start position:0% +5.29 + + + align:start position:0% +5.29 +* 10us 11 m or + + align:start position:0% +* 10us 11 m or + + + align:start position:0% +* 10us 11 m or +0.529 angstroms. I like the angstrom. + + align:start position:0% +0.529 angstroms. I like the angstrom. + + + align:start position:0% +0.529 angstroms. I like the angstrom. +It's 10 the minus 10 m. It's not an SI + + align:start position:0% +It's 10 the minus 10 m. It's not an SI + + + align:start position:0% +It's 10 the minus 10 m. It's not an SI +unit because it's not a multiple of 10 + + align:start position:0% +unit because it's not a multiple of 10 + + + align:start position:0% +unit because it's not a multiple of 10 +the 3. But I like the angstrom. I I I + + align:start position:0% +the 3. But I like the angstrom. I I I + + + align:start position:0% +the 3. But I like the angstrom. I I I +don't like the nanometer. I like the + + align:start position:0% +don't like the nanometer. I like the + + + align:start position:0% +don't like the nanometer. I like the +angstrom because atomic dimensions are + + align:start position:0% +angstrom because atomic dimensions are + + + align:start position:0% +angstrom because atomic dimensions are +conveniently measured by angstroms. + + align:start position:0% +conveniently measured by angstroms. + + + align:start position:0% +conveniently measured by angstroms. +And this is given a special symbol a + + align:start position:0% +And this is given a special symbol a + + + align:start position:0% +And this is given a special symbol a +knot. A knot. It's the value of the + + align:start position:0% +knot. A knot. It's the value of the + + + align:start position:0% +knot. A knot. It's the value of the +radius of the ground state electron + + align:start position:0% +radius of the ground state electron + + + align:start position:0% +radius of the ground state electron +orbit in atomic hydrogen. And this + + align:start position:0% +orbit in atomic hydrogen. And this + + + align:start position:0% +orbit in atomic hydrogen. And this +quantity is termed the bore radius. And + + align:start position:0% +quantity is termed the bore radius. And + + + align:start position:0% +quantity is termed the bore radius. And +you don't even have to look it up + + align:start position:0% +you don't even have to look it up + + + align:start position:0% +you don't even have to look it up +because it too is given on your on your + + align:start position:0% +because it too is given on your on your + + + align:start position:0% +because it too is given on your on your +table of constant. There's the plunk + + align:start position:0% +table of constant. There's the plunk + + + align:start position:0% +table of constant. There's the plunk +constant. It's number five. There's the + + align:start position:0% +constant. It's number five. There's the + + + align:start position:0% +constant. It's number five. There's the +bore radius down there. Number 24. So + + align:start position:0% +bore radius down there. Number 24. So + + + align:start position:0% +bore radius down there. Number 24. So +you just look that up and you know any + + align:start position:0% +you just look that up and you know any + + + align:start position:0% +you just look that up and you know any +anything else is going to be some some + + align:start position:0% +anything else is going to be some some + + + align:start position:0% +anything else is going to be some some +multiple of it. Um the other thing I'd + + align:start position:0% +multiple of it. Um the other thing I'd + + + align:start position:0% +multiple of it. Um the other thing I'd +like to draw your attention to is this + + align:start position:0% +like to draw your attention to is this + + + align:start position:0% +like to draw your attention to is this +that uh I can simplify this in the + + align:start position:0% +that uh I can simplify this in the + + + align:start position:0% +that uh I can simplify this in the +following manner. Say that Rn now that + + align:start position:0% +following manner. Say that Rn now that + + + align:start position:0% +following manner. Say that Rn now that +I've got a bore radius for this uh + + align:start position:0% +I've got a bore radius for this uh + + + align:start position:0% +I've got a bore radius for this uh +bracketed quantity. I can write that as + + align:start position:0% +bracketed quantity. I can write that as + + + align:start position:0% +bracketed quantity. I can write that as +the product of the bore radius for the + + align:start position:0% +the product of the bore radius for the + + + align:start position:0% +the product of the bore radius for the +value of the + + align:start position:0% +value of the + + + align:start position:0% +value of the +orbit in any one electron + + align:start position:0% +orbit in any one electron + + + align:start position:0% +orbit in any one electron +atom. Specify the quantum number + + align:start position:0% +atom. Specify the quantum number + + + align:start position:0% +atom. Specify the quantum number +n divide by z. So that's that's this + + align:start position:0% +n divide by z. So that's that's this + + + align:start position:0% +n divide by z. So that's that's this +rewritten in a much more compact + + align:start position:0% +rewritten in a much more compact + + + align:start position:0% +rewritten in a much more compact +notation because you have the value of + + align:start position:0% +notation because you have the value of + + + align:start position:0% +notation because you have the value of +this. And note that as z increases as + + align:start position:0% +this. And note that as z increases as + + + align:start position:0% +this. And note that as z increases as +the proton number increases the uh + + align:start position:0% +the proton number increases the uh + + + align:start position:0% +the proton number increases the uh +radius decreases for a given end number. + + align:start position:0% +radius decreases for a given end number. + + + align:start position:0% +radius decreases for a given end number. +So if you look at the ground state in + + align:start position:0% +So if you look at the ground state in + + + align:start position:0% +So if you look at the ground state in +two different systems, if you look at + + align:start position:0% +two different systems, if you look at + + + align:start position:0% +two different systems, if you look at +the ground state which is n equals 1. + + align:start position:0% +the ground state which is n equals 1. + + + align:start position:0% +the ground state which is n equals 1. +Think about this. If I increase the + + align:start position:0% +Think about this. If I increase the + + + align:start position:0% +Think about this. If I increase the +proton charge, the komic force of + + align:start position:0% +proton charge, the komic force of + + + align:start position:0% +proton charge, the komic force of +attraction is greater. And so therefore + + align:start position:0% +attraction is greater. And so therefore + + + align:start position:0% +attraction is greater. And so therefore +all other things being equal, the first + + align:start position:0% +all other things being equal, the first + + + align:start position:0% +all other things being equal, the first +orbit should be at a smaller distance. + + align:start position:0% +orbit should be at a smaller distance. + + + align:start position:0% +orbit should be at a smaller distance. +So this is making this is making + + align:start position:0% +So this is making this is making + + + align:start position:0% +So this is making this is making +physical sense. Okay. Now let's look at + + align:start position:0% +physical sense. Okay. Now let's look at + + + align:start position:0% +physical sense. Okay. Now let's look at +energy. Let's uh quantify the energy + + align:start position:0% +energy. Let's uh quantify the energy + + + align:start position:0% +energy. Let's uh quantify the energy +value. If you go through and solve for + + align:start position:0% +value. If you go through and solve for + + + align:start position:0% +value. If you go through and solve for +energy, you'll get this equation. E is + + align:start position:0% +energy, you'll get this equation. E is + + + align:start position:0% +energy, you'll get this equation. E is +equal to + + align:start position:0% +equal to + + + align:start position:0% +equal to +minus mass of the electron time the + + align:start position:0% +minus mass of the electron time the + + + align:start position:0% +minus mass of the electron time the +elementary charge raised to the 4th + + align:start position:0% +elementary charge raised to the 4th + + + align:start position:0% +elementary charge raised to the 4th +power / e * the square of the + + align:start position:0% +power / e * the square of the + + + align:start position:0% +power / e * the square of the +permitivity of vacuum time the square of + + align:start position:0% +permitivity of vacuum time the square of + + + align:start position:0% +permitivity of vacuum time the square of +the plank + + align:start position:0% +the plank + + + align:start position:0% +the plank +constant + + align:start position:0% +constant + + + align:start position:0% +constant +time z ^2 / + + align:start position:0% +time z ^2 / + + + align:start position:0% +time z ^2 / +n^2. So again we see that e is a + + align:start position:0% +n^2. So again we see that e is a + + + align:start position:0% +n^2. So again we see that e is a +function + + align:start position:0% +function + + + align:start position:0% +function +of n. You see the quantum condition by + + align:start position:0% +of n. You see the quantum condition by + + + align:start position:0% +of n. You see the quantum condition by +putting quantization into the angular + + align:start position:0% +putting quantization into the angular + + + align:start position:0% +putting quantization into the angular +momentum it's propagated through the + + align:start position:0% +momentum it's propagated through the + + + align:start position:0% +momentum it's propagated through the +entire system. Orbits dimensions are + + align:start position:0% +entire system. Orbits dimensions are + + + align:start position:0% +entire system. Orbits dimensions are +quantized. Energy is quantized. Velocity + + align:start position:0% +quantized. Energy is quantized. Velocity + + + align:start position:0% +quantized. Energy is quantized. Velocity +is quantized. Everything is quantized. + + align:start position:0% +is quantized. Everything is quantized. + + + align:start position:0% +is quantized. Everything is quantized. +So energy is quantized. It has a + + align:start position:0% +So energy is quantized. It has a + + + align:start position:0% +So energy is quantized. It has a +different n dependence. If I lump all of + + align:start position:0% +different n dependence. If I lump all of + + + align:start position:0% +different n dependence. If I lump all of +this together in some constant, I can + + align:start position:0% +this together in some constant, I can + + + align:start position:0% +this together in some constant, I can +then represent that formula as minus k * + + align:start position:0% +then represent that formula as minus k * + + + align:start position:0% +then represent that formula as minus k * +z + + align:start position:0% +z + + + align:start position:0% +z +^2 over n^2 where n again uh chooses + + align:start position:0% +^2 over n^2 where n again uh chooses + + + align:start position:0% +^2 over n^2 where n again uh chooses +integer values 1 2 3 and so on. And we + + align:start position:0% +integer values 1 2 3 and so on. And we + + + align:start position:0% +integer values 1 2 3 and so on. And we +can go through and and calculate the + + align:start position:0% +can go through and and calculate the + + + align:start position:0% +can go through and and calculate the +value of this quantity in parentheses. + + align:start position:0% +value of this quantity in parentheses. + + + align:start position:0% +value of this quantity in parentheses. +And when we do so we get the value 2.18 + + align:start position:0% +And when we do so we get the value 2.18 + + + align:start position:0% +And when we do so we get the value 2.18 +* 10 + + align:start position:0% +* 10 + + + align:start position:0% +* 10 +-18 + + align:start position:0% +-18 + + + align:start position:0% +-18 +Jew. This is 10 -8 Jew for this one + + align:start position:0% +Jew. This is 10 -8 Jew for this one + + + align:start position:0% +Jew. This is 10 -8 Jew for this one +atom. So I'm going to draw attention to + + align:start position:0% +atom. So I'm going to draw attention to + + + align:start position:0% +atom. So I'm going to draw attention to +this. It's jewels per + + align:start position:0% +this. It's jewels per + + + align:start position:0% +this. It's jewels per +atom. Or if you multiply by Avagadro's + + align:start position:0% +atom. Or if you multiply by Avagadro's + + + align:start position:0% +atom. Or if you multiply by Avagadro's +number then you'll get jewels per mole. + + align:start position:0% +number then you'll get jewels per mole. + + + align:start position:0% +number then you'll get jewels per mole. +And if you do so, you'll end up with + + align:start position:0% +And if you do so, you'll end up with + + + align:start position:0% +And if you do so, you'll end up with +1.312 + + align:start position:0% +1.312 + + + align:start position:0% +1.312 +megaj per mole for this quantity + + align:start position:0% +megaj per mole for this quantity + + + align:start position:0% +megaj per mole for this quantity +K. And and you can find that one too. + + align:start position:0% +K. And and you can find that one too. + + + align:start position:0% +K. And and you can find that one too. +That's on your that's on your chart. Uh + + align:start position:0% +That's on your that's on your chart. Uh + + + align:start position:0% +That's on your that's on your chart. Uh +if you multiply entry 23, which is 13.6 + + align:start position:0% +if you multiply entry 23, which is 13.6 + + + align:start position:0% +if you multiply entry 23, which is 13.6 +electron volts, I'll show you what the + + align:start position:0% +electron volts, I'll show you what the + + + align:start position:0% +electron volts, I'll show you what the +electron volt is in a in a few minutes. + + align:start position:0% +electron volt is in a in a few minutes. + + + align:start position:0% +electron volt is in a in a few minutes. +So we'll just put it up here + + align:start position:0% +So we'll just put it up here + + + align:start position:0% +So we'll just put it up here +prematurely, but that's given in your + + align:start position:0% +prematurely, but that's given in your + + + align:start position:0% +prematurely, but that's given in your +chart. And then the conversion of jewels + + align:start position:0% +chart. And then the conversion of jewels + + + align:start position:0% +chart. And then the conversion of jewels +to electron volts is entry 42. So if you + + align:start position:0% +to electron volts is entry 42. So if you + + + align:start position:0% +to electron volts is entry 42. So if you +multiply those two together, you'll end + + align:start position:0% +multiply those two together, you'll end + + + align:start position:0% +multiply those two together, you'll end +up with with this quantity. And so um + + align:start position:0% +up with with this quantity. And so um + + + align:start position:0% +up with with this quantity. And so um +let's take a look at what that + + align:start position:0% +let's take a look at what that + + + align:start position:0% +let's take a look at what that +does in terms of uh uh graphical + + align:start position:0% +does in terms of uh uh graphical + + + align:start position:0% +does in terms of uh uh graphical +representation. I tried to give you a + + align:start position:0% +representation. I tried to give you a + + + align:start position:0% +representation. I tried to give you a +simple graphical representation of uh so + + align:start position:0% +simple graphical representation of uh so + + + align:start position:0% +simple graphical representation of uh so +that was cartisian space, right? When I + + align:start position:0% +that was cartisian space, right? When I + + + align:start position:0% +that was cartisian space, right? When I +plot r as as a distance out from the + + align:start position:0% +plot r as as a distance out from the + + + align:start position:0% +plot r as as a distance out from the +nucleus, that's sort of our + + align:start position:0% +nucleus, that's sort of our + + + align:start position:0% +nucleus, that's sort of our +simple-minded planetary model. So now + + align:start position:0% +simple-minded planetary model. So now + + + align:start position:0% +simple-minded planetary model. So now +let's look at energy. So energy I'm + + align:start position:0% +let's look at energy. So energy I'm + + + align:start position:0% +let's look at energy. So energy I'm +going to put energy in the following + + align:start position:0% +going to put energy in the following + + + align:start position:0% +going to put energy in the following +manner. See it's a conservative system. + + align:start position:0% +manner. See it's a conservative system. + + + align:start position:0% +manner. See it's a conservative system. +So all the energies are negative, right? + + align:start position:0% +So all the energies are negative, right? + + + align:start position:0% +So all the energies are negative, right? +That quantity in parenthesis I've got a + + align:start position:0% +That quantity in parenthesis I've got a + + + align:start position:0% +That quantity in parenthesis I've got a +mass which is a positive number. + + align:start position:0% +mass which is a positive number. + + + align:start position:0% +mass which is a positive number. +Something raised to the fourth power has + + align:start position:0% +Something raised to the fourth power has + + + align:start position:0% +Something raised to the fourth power has +got to be positive. Something raised to + + align:start position:0% +got to be positive. Something raised to + + + align:start position:0% +got to be positive. Something raised to +the second power it's got to be + + align:start position:0% +the second power it's got to be + + + align:start position:0% +the second power it's got to be +positive. So everything inside the + + align:start position:0% +positive. So everything inside the + + + align:start position:0% +positive. So everything inside the +parenthesis is positive. So minus a + + align:start position:0% +parenthesis is positive. So minus a + + + align:start position:0% +parenthesis is positive. So minus a +positive number. All the energies are + + align:start position:0% +positive number. All the energies are + + + align:start position:0% +positive number. All the energies are +negative because it's a bound system. So + + align:start position:0% +negative because it's a bound system. So + + + align:start position:0% +negative because it's a bound system. So +I start up + + align:start position:0% +I start up + + + align:start position:0% +I start up +here with n= 1 and uh over here this is + + align:start position:0% +here with n= 1 and uh over here this is + + + align:start position:0% +here with n= 1 and uh over here this is +the value of minus k and then if we go + + align:start position:0% +the value of minus k and then if we go + + + align:start position:0% +the value of minus k and then if we go +to n equals 2 what happens? We go to n= + + align:start position:0% +to n equals 2 what happens? We go to n= + + + align:start position:0% +to n equals 2 what happens? We go to n= +2 for a fixed value of z. Uh let's make + + align:start position:0% +2 for a fixed value of z. Uh let's make + + + align:start position:0% +2 for a fixed value of z. Uh let's make +this z equals 1. We'll do it for atomic + + align:start position:0% +this z equals 1. We'll do it for atomic + + + align:start position:0% +this z equals 1. We'll do it for atomic +hydrogen. So it's k over + + align:start position:0% + + + + align:start position:0% + +4 and then we go to n= 3. This is not to + + align:start position:0% +4 and then we go to n= 3. This is not to + + + align:start position:0% +4 and then we go to n= 3. This is not to +scale + + align:start position:0% + + + + align:start position:0% + +but and so on. So this is what uh the + + align:start position:0% +but and so on. So this is what uh the + + + align:start position:0% +but and so on. So this is what uh the +energy level diagram looks like. This is + + align:start position:0% +energy level diagram looks like. This is + + + align:start position:0% +energy level diagram looks like. This is +for atomic hydrogen gas. And I'm going + + align:start position:0% +for atomic hydrogen gas. And I'm going + + + align:start position:0% +for atomic hydrogen gas. And I'm going +to put on here not to + + align:start position:0% +to put on here not to + + + align:start position:0% +to put on here not to +scale. There's some relative the notion + + align:start position:0% +scale. There's some relative the notion + + + align:start position:0% +scale. There's some relative the notion +that the that the energy gap between n=1 + + align:start position:0% +that the that the energy gap between n=1 + + + align:start position:0% +that the that the energy gap between n=1 +and n=2 is greater than that for n= 2 to + + align:start position:0% +and n=2 is greater than that for n= 2 to + + + align:start position:0% +and n=2 is greater than that for n= 2 to +n= 3. That's correctly represented. + + align:start position:0% +n= 3. That's correctly represented. + + + align:start position:0% +n= 3. That's correctly represented. +These are definitely not equally spaced, + + align:start position:0% +These are definitely not equally spaced, + + + align:start position:0% +These are definitely not equally spaced, +but they should be even more uh + + align:start position:0% +but they should be even more uh + + + align:start position:0% +but they should be even more uh +disproportionate than I than I've shown + + align:start position:0% +disproportionate than I than I've shown + + + align:start position:0% +disproportionate than I than I've shown +it. Um, and finally up here we have n + + align:start position:0% +it. Um, and finally up here we have n + + + align:start position:0% +it. Um, and finally up here we have n +equals infinity. When n equals infinity, + + align:start position:0% +equals infinity. When n equals infinity, + + + align:start position:0% +equals infinity. When n equals infinity, +r equals infinity. And so the energy is + + align:start position:0% +r equals infinity. And so the energy is + + + align:start position:0% +r equals infinity. And so the energy is +zero because the electron is no longer + + align:start position:0% +zero because the electron is no longer + + + align:start position:0% +zero because the electron is no longer +bound. It's free. The electron has been + + align:start position:0% +bound. It's free. The electron has been + + + align:start position:0% +bound. It's free. The electron has been +liberated. This represents the uh free + + align:start position:0% +liberated. This represents the uh free + + + align:start position:0% +liberated. This represents the uh free +electron. It's no longer tethered to the + + align:start position:0% +electron. It's no longer tethered to the + + + align:start position:0% +electron. It's no longer tethered to the +nucleus. So there's no energy stored in + + align:start position:0% +nucleus. So there's no energy stored in + + + align:start position:0% +nucleus. So there's no energy stored in +the system and the the the the closer it + + align:start position:0% +the system and the the the the closer it + + + align:start position:0% +the system and the the the the closer it +gets to the nucleus the greater the + + align:start position:0% +gets to the nucleus the greater the + + + align:start position:0% +gets to the nucleus the greater the +amount of energy which means that you + + align:start position:0% +amount of energy which means that you + + + align:start position:0% +amount of energy which means that you +see this in the following manner. Uh + + align:start position:0% +see this in the following manner. Uh + + + align:start position:0% +see this in the following manner. Uh +this is called the ground state n equals + + align:start position:0% +this is called the ground state n equals + + + align:start position:0% +this is called the ground state n equals +1. I already mentioned that it's like + + align:start position:0% +1. I already mentioned that it's like + + + align:start position:0% +1. I already mentioned that it's like +the ground floor. I know some of you + + align:start position:0% +the ground floor. I know some of you + + + align:start position:0% +the ground floor. I know some of you +come from Europe and other parts of the + + align:start position:0% +come from Europe and other parts of the + + + align:start position:0% +come from Europe and other parts of the +world where they have uh the ground + + align:start position:0% +world where they have uh the ground + + + align:start position:0% +world where they have uh the ground +floor is the chos or some silly thing + + align:start position:0% +floor is the chos or some silly thing + + + align:start position:0% +floor is the chos or some silly thing +like this and you push the button on the + + align:start position:0% +like this and you push the button on the + + + align:start position:0% +like this and you push the button on the +elevator to one and you go up to the + + align:start position:0% +elevator to one and you go up to the + + + align:start position:0% +elevator to one and you go up to the +first floor. You are in America now and + + align:start position:0% +first floor. You are in America now and + + + align:start position:0% +first floor. You are in America now and +the international chemical community + + align:start position:0% +the international chemical community + + + align:start position:0% +the international chemical community +calls the ground state n equals 1 not n + + align:start position:0% +calls the ground state n equals 1 not n + + + align:start position:0% +calls the ground state n equals 1 not n +equals zero. So please observe the + + align:start position:0% +equals zero. So please observe the + + + align:start position:0% +equals zero. So please observe the +traditions of the international union of + + align:start position:0% +traditions of the international union of + + + align:start position:0% +traditions of the international union of +pure and applied chemistry not to + + align:start position:0% +pure and applied chemistry not to + + + align:start position:0% +pure and applied chemistry not to +mention Neil's bore. Okay. So this is + + align:start position:0% +mention Neil's bore. Okay. So this is + + + align:start position:0% +mention Neil's bore. Okay. So this is +ground state. These are the excited + + align:start position:0% +ground state. These are the excited + + + align:start position:0% +ground state. These are the excited +states. These are the excited states. + + align:start position:0% +states. These are the excited states. + + + align:start position:0% +states. These are the excited states. +And free electron at n equals infinity. + + align:start position:0% +And free electron at n equals infinity. + + + align:start position:0% +And free electron at n equals infinity. +And at this point we say that the the + + align:start position:0% +And at this point we say that the the + + + align:start position:0% +And at this point we say that the the +atom has + + align:start position:0% +atom has + + + align:start position:0% +atom has +become has become + + align:start position:0% +become has become + + + align:start position:0% +become has become +ionized ionized. That is to say the + + align:start position:0% +ionized ionized. That is to say the + + + align:start position:0% +ionized ionized. That is to say the +electron has been ejected. And so now we + + align:start position:0% +electron has been ejected. And so now we + + + align:start position:0% +electron has been ejected. And so now we +have net charge. And we can calculate + + align:start position:0% +have net charge. And we can calculate + + + align:start position:0% +have net charge. And we can calculate +the ionization energy. The ionization + + align:start position:0% +the ionization energy. The ionization + + + align:start position:0% +the ionization energy. The ionization +energy must then be nothing more than + + align:start position:0% +energy must then be nothing more than + + + align:start position:0% +energy must then be nothing more than +that's the energy to go from the ground + + align:start position:0% +that's the energy to go from the ground + + + align:start position:0% +that's the energy to go from the ground +state here from the ground state to n + + align:start position:0% +state here from the ground state to n + + + align:start position:0% +state here from the ground state to n +equals infinity. So that would be the + + align:start position:0% +equals infinity. So that would be the + + + align:start position:0% +equals infinity. So that would be the +energy at state infinity minus the + + align:start position:0% +energy at state infinity minus the + + + align:start position:0% +energy at state infinity minus the +energy of the ground state. Well the + + align:start position:0% +energy of the ground state. Well the + + + align:start position:0% +energy of the ground state. Well the +energy at infinity is zero and the + + align:start position:0% +energy at infinity is zero and the + + + align:start position:0% +energy at infinity is zero and the +energy in the ground state is minus k. + + align:start position:0% +energy in the ground state is minus k. + + + align:start position:0% +energy in the ground state is minus k. +So min - k is plus k. So k in fact is + + align:start position:0% +So min - k is plus k. So k in fact is + + + align:start position:0% +So min - k is plus k. So k in fact is +the ionization energy. And in fact if + + align:start position:0% +the ionization energy. And in fact if + + + align:start position:0% +the ionization energy. And in fact if +you go + + align:start position:0% +you go + + + align:start position:0% +you go +to if you go to the chart to your + + align:start position:0% +to if you go to the chart to your + + + align:start position:0% +to if you go to the chart to your +periodic table uh indeed there it is. So + + align:start position:0% +periodic table uh indeed there it is. So + + + align:start position:0% +periodic table uh indeed there it is. So +here, this is a a slightly different + + align:start position:0% +here, this is a a slightly different + + + align:start position:0% +here, this is a a slightly different +version from the one you have, but it's + + align:start position:0% +version from the one you have, but it's + + + align:start position:0% +version from the one you have, but it's +the same order. If you look on the + + align:start position:0% +the same order. If you look on the + + + align:start position:0% +the same order. If you look on the +periodic table, this is atomic hydrogen. + + align:start position:0% +periodic table, this is atomic hydrogen. + + + align:start position:0% +periodic table, this is atomic hydrogen. +And sure enough, there's + + align:start position:0% +And sure enough, there's + + + align:start position:0% +And sure enough, there's +13.598, which is this number here in + + align:start position:0% +13.598, which is this number here in + + + align:start position:0% +13.598, which is this number here in +electron volts. That's the ground state + + align:start position:0% +electron volts. That's the ground state + + + align:start position:0% +electron volts. That's the ground state +energy of atomic hydrogen. The other + + align:start position:0% +energy of atomic hydrogen. The other + + + align:start position:0% +energy of atomic hydrogen. The other +thing to note is look at the dependence + + align:start position:0% +thing to note is look at the dependence + + + align:start position:0% +thing to note is look at the dependence +upon Z. + + align:start position:0% +upon Z. + + + align:start position:0% +upon Z. +Suppose instead of hydrogen we + + align:start position:0% +Suppose instead of hydrogen we + + + align:start position:0% +Suppose instead of hydrogen we +considered lithium plus excuse me uh + + align:start position:0% +considered lithium plus excuse me uh + + + align:start position:0% +considered lithium plus excuse me uh +lithium 2+. Lithium 2+ is a is a one + + align:start position:0% +lithium 2+. Lithium 2+ is a is a one + + + align:start position:0% +lithium 2+. Lithium 2+ is a is a one +electron atom. Lithium has three + + align:start position:0% +electron atom. Lithium has three + + + align:start position:0% +electron atom. Lithium has three +electrons. If it loses two, one remains. + + align:start position:0% +electrons. If it loses two, one remains. + + + align:start position:0% +electrons. If it loses two, one remains. +What is this formula telling us? It's + + align:start position:0% +What is this formula telling us? It's + + + align:start position:0% +What is this formula telling us? It's +telling us that the ground state in + + align:start position:0% +telling us that the ground state in + + + align:start position:0% +telling us that the ground state in +lithium would be z. It would be nine + + align:start position:0% +lithium would be z. It would be nine + + + align:start position:0% +lithium would be z. It would be nine +times more intense. It' be nine times + + align:start position:0% +times more intense. It' be nine times + + + align:start position:0% +times more intense. It' be nine times +less. That is to say -9 is less than + + align:start position:0% +less. That is to say -9 is less than + + + align:start position:0% +less. That is to say -9 is less than +minus1. Okay. And that makes sense too + + align:start position:0% +minus1. Okay. And that makes sense too + + + align:start position:0% +minus1. Okay. And that makes sense too +because the positive3 pulling on minus1 + + align:start position:0% +because the positive3 pulling on minus1 + + + align:start position:0% +because the positive3 pulling on minus1 +has a tighter binding energy than + + align:start position:0% +has a tighter binding energy than + + + align:start position:0% +has a tighter binding energy than +positive one pulling on minus1. So this + + align:start position:0% +positive one pulling on minus1. So this + + + align:start position:0% +positive one pulling on minus1. So this +drops by the square whereas the you saw + + align:start position:0% +drops by the square whereas the you saw + + + align:start position:0% +drops by the square whereas the you saw +how the the orbit goes. Um so just + + align:start position:0% +how the the orbit goes. Um so just + + + align:start position:0% +how the the orbit goes. Um so just +picking up on this ionization energy the + + align:start position:0% +picking up on this ionization energy the + + + align:start position:0% +picking up on this ionization energy the +ionization energy we can define as this + + align:start position:0% +ionization energy we can define as this + + + align:start position:0% +ionization energy we can define as this +is the minimum energy. This is the + + align:start position:0% +is the minimum energy. This is the + + + align:start position:0% +is the minimum energy. This is the +minimum energy to remove an electron. + + align:start position:0% +minimum energy to remove an electron. + + + align:start position:0% +minimum energy to remove an electron. +to remove an electron from the ground + + align:start position:0% + + + + align:start position:0% + +state from the ground state. Take out + + align:start position:0% +state from the ground state. Take out + + + align:start position:0% +state from the ground state. Take out +that ambiguity of an atom in the gas + + align:start position:0% +that ambiguity of an atom in the gas + + + align:start position:0% +that ambiguity of an atom in the gas +phase. All the things we're talking + + align:start position:0% +phase. All the things we're talking + + + align:start position:0% +phase. All the things we're talking +about here are with reference to the gas + + align:start position:0% +about here are with reference to the gas + + + align:start position:0% +about here are with reference to the gas +phase. Gas phase single atom. So we + + align:start position:0% +phase. Gas phase single atom. So we + + + align:start position:0% +phase. Gas phase single atom. So we +don't have to deal with work function or + + align:start position:0% +don't have to deal with work function or + + + align:start position:0% +don't have to deal with work function or +any kind of energies associated with + + align:start position:0% +any kind of energies associated with + + + align:start position:0% +any kind of energies associated with +some condensed form of matter. So we're + + align:start position:0% +some condensed form of matter. So we're + + + align:start position:0% +some condensed form of matter. So we're +really looking at uh this reaction here + + align:start position:0% +really looking at uh this reaction here + + + align:start position:0% +really looking at uh this reaction here +for ionization. It's H gas neutral goes + + align:start position:0% +for ionization. It's H gas neutral goes + + + align:start position:0% +for ionization. It's H gas neutral goes +to + + align:start position:0% +to + + + align:start position:0% +to +H+ in the gas phase plus the electron. + + align:start position:0% +H+ in the gas phase plus the electron. + + + align:start position:0% +H+ in the gas phase plus the electron. +Okay. And furthermore, we can have + + align:start position:0% +Okay. And furthermore, we can have + + + align:start position:0% +Okay. And furthermore, we can have +multiple ionization energies. If you + + align:start position:0% +multiple ionization energies. If you + + + align:start position:0% +multiple ionization energies. If you +have multiple electrons, we can lose + + align:start position:0% +have multiple electrons, we can lose + + + align:start position:0% +have multiple electrons, we can lose +them in sequence. So for example, I + + align:start position:0% +them in sequence. So for example, I + + + align:start position:0% +them in sequence. So for example, I +could look at the ionization of lithium. + + align:start position:0% +could look at the ionization of lithium. + + + align:start position:0% +could look at the ionization of lithium. +Again, lithium gas. lithium gas loses an + + align:start position:0% +Again, lithium gas. lithium gas loses an + + + align:start position:0% +Again, lithium gas. lithium gas loses an +electron to become lithium + + align:start position:0% +electron to become lithium + + + align:start position:0% +electron to become lithium +ion plus electron. I can then + + align:start position:0% +ion plus electron. I can then + + + align:start position:0% +ion plus electron. I can then +subsequently lose an electron from the + + align:start position:0% +subsequently lose an electron from the + + + align:start position:0% +subsequently lose an electron from the +lithium ion. So lithium ion loses an + + align:start position:0% +lithium ion. So lithium ion loses an + + + align:start position:0% +lithium ion. So lithium ion loses an +electron to become lithium + + align:start position:0% +electron to become lithium + + + align:start position:0% +electron to become lithium +2+ and the lithium 2+ still has an + + align:start position:0% +2+ and the lithium 2+ still has an + + + align:start position:0% +2+ and the lithium 2+ still has an +electron. Let's dnude lithium 2+. So + + align:start position:0% +electron. Let's dnude lithium 2+. So + + + align:start position:0% +electron. Let's dnude lithium 2+. So +lithium 2+ loses its electron to become + + align:start position:0% +lithium 2+ loses its electron to become + + + align:start position:0% +lithium 2+ loses its electron to become +just the this is the analogy to the + + align:start position:0% +just the this is the analogy to the + + + align:start position:0% +just the this is the analogy to the +alpha particle, right? This alpha + + align:start position:0% +alpha particle, right? This alpha + + + align:start position:0% +alpha particle, right? This alpha +particle was the helium nucleus. This is + + align:start position:0% +particle was the helium nucleus. This is + + + align:start position:0% +particle was the helium nucleus. This is +the lithium nucleus plus electron. So we + + align:start position:0% +the lithium nucleus plus electron. So we + + + align:start position:0% +the lithium nucleus plus electron. So we +call these first, second, third + + align:start position:0% +call these first, second, third + + + align:start position:0% +call these first, second, third +ionization energies in sequence. Right? + + align:start position:0% +ionization energies in sequence. Right? + + + align:start position:0% +ionization energies in sequence. Right? +This is this is the first + + align:start position:0% +This is this is the first + + + align:start position:0% +This is this is the first +ionization energy. This is the second + + align:start position:0% +ionization energy. This is the second + + + align:start position:0% +ionization energy. This is the second +ionization energy. That is to say the + + align:start position:0% +ionization energy. That is to say the + + + align:start position:0% +ionization energy. That is to say the +ionization energy of the + + align:start position:0% +ionization energy of the + + + align:start position:0% +ionization energy of the +second most electron. And this is the + + align:start position:0% +second most electron. And this is the + + + align:start position:0% +second most electron. And this is the +third ionization energy. Now where do we + + align:start position:0% +third ionization energy. Now where do we + + + align:start position:0% +third ionization energy. Now where do we +find these values? Well, if we look on + + align:start position:0% +find these values? Well, if we look on + + + align:start position:0% +find these values? Well, if we look on +the chart, the first ionization energy + + align:start position:0% +the chart, the first ionization energy + + + align:start position:0% +the chart, the first ionization energy +is what is reported in your periodic + + align:start position:0% +is what is reported in your periodic + + + align:start position:0% +is what is reported in your periodic +table. So, the first ionization energy + + align:start position:0% +table. So, the first ionization energy + + + align:start position:0% +table. So, the first ionization energy +of lithium is about + + align:start position:0% +of lithium is about + + + align:start position:0% +of lithium is about +5.4 electron volts per atom. So, we can + + align:start position:0% +5.4 electron volts per atom. So, we can + + + align:start position:0% +5.4 electron volts per atom. So, we can +get this uh from the periodic table. + + align:start position:0% +get this uh from the periodic table. + + + align:start position:0% +get this uh from the periodic table. +Okay, + + align:start position:0% +Okay, + + + align:start position:0% +Okay, +reported in periodic table and this is + + align:start position:0% +reported in periodic table and this is + + + align:start position:0% +reported in periodic table and this is +determined by measurement. This is + + align:start position:0% +determined by measurement. This is + + + align:start position:0% +determined by measurement. This is +determined by measurement. + + align:start position:0% +determined by measurement. + + + align:start position:0% +determined by measurement. +Uh, this one + + align:start position:0% +Uh, this one + + + align:start position:0% +Uh, this one +here can't do anything for you. I have + + align:start position:0% +here can't do anything for you. I have + + + align:start position:0% +here can't do anything for you. I have +to look that one up. What about this + + align:start position:0% +to look that one up. What about this + + + align:start position:0% +to look that one up. What about this +one? This one is calculable by the bore + + align:start position:0% +one? This one is calculable by the bore + + + align:start position:0% +one? This one is calculable by the bore +model because lithium 2+ is a one + + align:start position:0% +model because lithium 2+ is a one + + + align:start position:0% +model because lithium 2+ is a one +electron system. So, I just go through + + align:start position:0% +electron system. So, I just go through + + + align:start position:0% +electron system. So, I just go through +these equations. But be careful to put + + align:start position:0% +these equations. But be careful to put + + + align:start position:0% +these equations. But be careful to put +in Z= 3 and I can calculate this from + + align:start position:0% +in Z= 3 and I can calculate this from + + + align:start position:0% +in Z= 3 and I can calculate this from +bore + + align:start position:0% +bore + + + align:start position:0% +bore +model. Bore model. Let's say calculable. + + align:start position:0% +model. Bore model. Let's say calculable. + + + align:start position:0% +model. Bore model. Let's say calculable. +calculable by bore model and then + + align:start position:0% +calculable by bore model and then + + + align:start position:0% +calculable by bore model and then +remember Z equals 3. So, showing some + + align:start position:0% +remember Z equals 3. So, showing some + + + align:start position:0% +remember Z equals 3. So, showing some +versatility here. And let's see, we've + + align:start position:0% +versatility here. And let's see, we've + + + align:start position:0% +versatility here. And let's see, we've +talked about um radius, we've talked + + align:start position:0% +talked about um radius, we've talked + + + align:start position:0% +talked about um radius, we've talked +about energy. Let's talk about velocity. + + align:start position:0% +about energy. Let's talk about velocity. + + + align:start position:0% +about energy. Let's talk about velocity. +Just for + + align:start position:0% + + + + align:start position:0% + +completeness. Uh so the velocity is + + align:start position:0% +completeness. Uh so the velocity is + + + align:start position:0% +completeness. Uh so the velocity is +given by this uh product of the the + + align:start position:0% +given by this uh product of the the + + + align:start position:0% +given by this uh product of the the +quantum number n plank constant 2 pi + + align:start position:0% +quantum number n plank constant 2 pi + + + align:start position:0% +quantum number n plank constant 2 pi +mass of the electron time the radius of + + align:start position:0% +mass of the electron time the radius of + + + align:start position:0% +mass of the electron time the radius of +the orbit which itself is a function of + + align:start position:0% +the orbit which itself is a function of + + + align:start position:0% +the orbit which itself is a function of +n. We can make some substitutions here + + align:start position:0% +n. We can make some substitutions here + + + align:start position:0% +n. We can make some substitutions here +using some of the derivation on the + + align:start position:0% +using some of the derivation on the + + + align:start position:0% +using some of the derivation on the +previous board which will give us the + + align:start position:0% +previous board which will give us the + + + align:start position:0% +previous board which will give us the +plank constant / 2 pi mass of the + + align:start position:0% +plank constant / 2 pi mass of the + + + align:start position:0% +plank constant / 2 pi mass of the +electron times the bore + + align:start position:0% +electron times the bore + + + align:start position:0% +electron times the bore +radius. All of this times the ratio of Z + + align:start position:0% +radius. All of this times the ratio of Z + + + align:start position:0% +radius. All of this times the ratio of Z +over N where N equals 1 2 3 + + align:start position:0% +over N where N equals 1 2 3 + + + align:start position:0% +over N where N equals 1 2 3 +so and we rarely look at velocity + + align:start position:0% +so and we rarely look at velocity + + + align:start position:0% +so and we rarely look at velocity +because we don't as you'll learn very + + align:start position:0% +because we don't as you'll learn very + + + align:start position:0% +because we don't as you'll learn very +quickly in 3091 we're not we're going to + + align:start position:0% +quickly in 3091 we're not we're going to + + + align:start position:0% +quickly in 3091 we're not we're going to +abandon this strict adherence to a + + align:start position:0% +abandon this strict adherence to a + + + align:start position:0% +abandon this strict adherence to a +planetary model pretty soon but it is + + align:start position:0% +planetary model pretty soon but it is + + + align:start position:0% +planetary model pretty soon but it is +interesting. Let's just for an order of + + align:start position:0% +interesting. Let's just for an order of + + + align:start position:0% +interesting. Let's just for an order of +magnitude say what happens um for ground + + align:start position:0% +magnitude say what happens um for ground + + + align:start position:0% +magnitude say what happens um for ground +state electron and atomic hydrogen. So + + align:start position:0% +state electron and atomic hydrogen. So + + + align:start position:0% +state electron and atomic hydrogen. So +we're going to put atomic hydrogen Z + + align:start position:0% +we're going to put atomic hydrogen Z + + + align:start position:0% +we're going to put atomic hydrogen Z +equals 1 ground state N= 1 that's just + + align:start position:0% +equals 1 ground state N= 1 that's just + + + align:start position:0% +equals 1 ground state N= 1 that's just +this quantity here. So let's find out. + + align:start position:0% +this quantity here. So let's find out. + + + align:start position:0% +this quantity here. So let's find out. +So V1 in atomic hydrogen. Is it fast? Is + + align:start position:0% +So V1 in atomic hydrogen. Is it fast? Is + + + align:start position:0% +So V1 in atomic hydrogen. Is it fast? Is +it slow? What's the number? Plug in the + + align:start position:0% +it slow? What's the number? Plug in the + + + align:start position:0% +it slow? What's the number? Plug in the +values. You get 2.18 * + + align:start position:0% +values. You get 2.18 * + + + align:start position:0% +values. You get 2.18 * +10us uh excuse me 10 + 6 m/s. + + align:start position:0% +10us uh excuse me 10 + 6 m/s. + + + align:start position:0% +10us uh excuse me 10 + 6 m/s. +10 plus 6 meters/s which is about 1% of + + align:start position:0% +10 plus 6 meters/s which is about 1% of + + + align:start position:0% +10 plus 6 meters/s which is about 1% of +the value of the speed of light 1% of + + align:start position:0% +the value of the speed of light 1% of + + + align:start position:0% +the value of the speed of light 1% of +the value of speed of light by the way C + + align:start position:0% +the value of speed of light by the way C + + + align:start position:0% +the value of speed of light by the way C +the value of speed of light in case you + + align:start position:0% +the value of speed of light in case you + + + align:start position:0% +the value of speed of light in case you +can't remember it is the number one + + align:start position:0% +can't remember it is the number one + + + align:start position:0% +can't remember it is the number one +entry in your in your table of constants + + align:start position:0% +entry in your in your table of constants + + + align:start position:0% +entry in your in your table of constants +so 1% of speed of light so I would say + + align:start position:0% +so 1% of speed of light so I would say + + + align:start position:0% +so 1% of speed of light so I would say +that's relatively fast that's a pun + + align:start position:0% +that's relatively fast that's a pun + + + align:start position:0% +that's relatively fast that's a pun +there think about this is a relatively + + align:start position:0% + + + + align:start position:0% + +fast yeah this is people have no sense + + align:start position:0% +fast yeah this is people have no sense + + + align:start position:0% +fast yeah this is people have no sense +of humor no sense of joy no sense of uh + + align:start position:0% +of humor no sense of joy no sense of uh + + + align:start position:0% +of humor no sense of joy no sense of uh +dev. You're so young. You've only been + + align:start position:0% +dev. You're so young. You've only been + + + align:start position:0% +dev. You're so young. You've only been +here a week and so jaded. You got four + + align:start position:0% +here a week and so jaded. You got four + + + align:start position:0% +here a week and so jaded. You got four +years to + + align:start position:0% +years to + + + align:start position:0% +years to +go. So where does C come from? How come + + align:start position:0% +go. So where does C come from? How come + + + align:start position:0% +go. So where does C come from? How come +the speed of light has the symbol C? + + align:start position:0% +the speed of light has the symbol C? + + + align:start position:0% +the speed of light has the symbol C? +Where is the symbol C? It comes from the + + align:start position:0% +Where is the symbol C? It comes from the + + + align:start position:0% +Where is the symbol C? It comes from the +Latin + + align:start position:0% +Latin + + + align:start position:0% +Latin +word caleritas, which means swiftness. + + align:start position:0% +word caleritas, which means swiftness. + + + align:start position:0% +word caleritas, which means swiftness. +We get the English word accelerate from + + align:start position:0% +We get the English word accelerate from + + + align:start position:0% +We get the English word accelerate from +the same root word. That's why that's + + align:start position:0% +the same root word. That's why that's + + + align:start position:0% +the same root word. That's why that's +why we have one. That's why we have C. + + align:start position:0% +why we have one. That's why we have C. + + + align:start position:0% +why we have one. That's why we have C. +All right. So we're in pretty good shape + + align:start position:0% +All right. So we're in pretty good shape + + + align:start position:0% +All right. So we're in pretty good shape +here. We've got a bore model. Bore + + align:start position:0% +here. We've got a bore model. Bore + + + align:start position:0% +here. We've got a bore model. Bore +model's quantitative. So, um, it makes + + align:start position:0% +model's quantitative. So, um, it makes + + + align:start position:0% +model's quantitative. So, um, it makes +predictions that can be tested. We've + + align:start position:0% +predictions that can be tested. We've + + + align:start position:0% +predictions that can be tested. We've +got energies. We got + + align:start position:0% +got energies. We got + + + align:start position:0% +got energies. We got +radi. So, is there any experimental + + align:start position:0% +radi. So, is there any experimental + + + align:start position:0% +radi. So, is there any experimental +evidence that can put this to the test? + + align:start position:0% +evidence that can put this to the test? + + + align:start position:0% +evidence that can put this to the test? +And the answer is yes. In the early + + align:start position:0% +And the answer is yes. In the early + + + align:start position:0% +And the answer is yes. In the early +1850s, + + align:start position:0% +1850s, + + + align:start position:0% +1850s, +um, Angstrom Angstrom up at the, uh, + + align:start position:0% +um, Angstrom Angstrom up at the, uh, + + + align:start position:0% +um, Angstrom Angstrom up at the, uh, +University of of Upsula in Sweden was + + align:start position:0% +University of of Upsula in Sweden was + + + align:start position:0% +University of of Upsula in Sweden was +conducting experiments on atomic + + align:start position:0% +conducting experiments on atomic + + + align:start position:0% +conducting experiments on atomic +hydrogen. He was doing experiments in a + + align:start position:0% +hydrogen. He was doing experiments in a + + + align:start position:0% +hydrogen. He was doing experiments in a +gas discharge tube. He had a tube with + + align:start position:0% +gas discharge tube. He had a tube with + + + align:start position:0% +gas discharge tube. He had a tube with +electrodes potted in it filled with + + align:start position:0% +electrodes potted in it filled with + + + align:start position:0% +electrodes potted in it filled with +atomic hydrogen and by applying a + + align:start position:0% +atomic hydrogen and by applying a + + + align:start position:0% +atomic hydrogen and by applying a +voltage he was able to get the gas to + + align:start position:0% +voltage he was able to get the gas to + + + align:start position:0% +voltage he was able to get the gas to +glow and then he analyzed the components + + align:start position:0% +glow and then he analyzed the components + + + align:start position:0% +glow and then he analyzed the components +of that radiation and this is what he + + align:start position:0% +of that radiation and this is what he + + + align:start position:0% +of that radiation and this is what he +found. First of all, let's take a look + + align:start position:0% +found. First of all, let's take a look + + + align:start position:0% +found. First of all, let's take a look +at his experiment. Uh there it is. This + + align:start position:0% +at his experiment. Uh there it is. This + + + align:start position:0% +at his experiment. Uh there it is. This +is he used the prism spectrograph to + + align:start position:0% +is he used the prism spectrograph to + + + align:start position:0% +is he used the prism spectrograph to +analyze his results. So what do we have + + align:start position:0% +analyze his results. So what do we have + + + align:start position:0% +analyze his results. So what do we have +here? Here's the gas discharge tube. + + align:start position:0% +here? Here's the gas discharge tube. + + + align:start position:0% +here? Here's the gas discharge tube. +This is the diagram taken right from + + align:start position:0% +This is the diagram taken right from + + + align:start position:0% +This is the diagram taken right from +your text. It's uh there's the two + + align:start position:0% +your text. It's uh there's the two + + + align:start position:0% +your text. It's uh there's the two +electrodes coming in and this is atomic + + align:start position:0% +electrodes coming in and this is atomic + + + align:start position:0% +electrodes coming in and this is atomic +hydrogen in the gas tube. And so if he + + align:start position:0% +hydrogen in the gas tube. And so if he + + + align:start position:0% +hydrogen in the gas tube. And so if he +gets the voltage high enough, this gas + + align:start position:0% +gets the voltage high enough, this gas + + + align:start position:0% +gets the voltage high enough, this gas +discharge tube will glow and the light + + align:start position:0% +discharge tube will glow and the light + + + align:start position:0% +discharge tube will glow and the light +will be going in all directions. + + align:start position:0% +will be going in all directions. + + + align:start position:0% +will be going in all directions. +Obviously, it's a glass tube. So he he + + align:start position:0% +Obviously, it's a glass tube. So he he + + + align:start position:0% +Obviously, it's a glass tube. So he he +wants to narrow the light. So he puts a + + align:start position:0% +wants to narrow the light. So he puts a + + + align:start position:0% +wants to narrow the light. So he puts a +couple of slits here and then he just + + align:start position:0% +couple of slits here and then he just + + + align:start position:0% +couple of slits here and then he just +takes that narrow column of light and he + + align:start position:0% +takes that narrow column of light and he + + + align:start position:0% +takes that narrow column of light and he +admits it to a prism. And what the prism + + align:start position:0% +admits it to a prism. And what the prism + + + align:start position:0% +admits it to a prism. And what the prism +does is it takes a tiny tiny difference + + align:start position:0% +does is it takes a tiny tiny difference + + + align:start position:0% +does is it takes a tiny tiny difference +in wavelength and refracts it through a + + align:start position:0% +in wavelength and refracts it through a + + + align:start position:0% +in wavelength and refracts it through a +different angle. And if the prism is of + + align:start position:0% +different angle. And if the prism is of + + + align:start position:0% +different angle. And if the prism is of +sufficient dimension that angle can be + + align:start position:0% +sufficient dimension that angle can be + + + align:start position:0% +sufficient dimension that angle can be +magnified and then further you put a + + align:start position:0% +magnified and then further you put a + + + align:start position:0% +magnified and then further you put a +some recording device which in those + + align:start position:0% +some recording device which in those + + + align:start position:0% +some recording device which in those +days was a photographic plate far across + + align:start position:0% +days was a photographic plate far across + + + align:start position:0% +days was a photographic plate far across +a room. So you take a tiny tiny angle + + align:start position:0% +a room. So you take a tiny tiny angle + + + align:start position:0% +a room. So you take a tiny tiny angle +and you go far enough across the room + + align:start position:0% +and you go far enough across the room + + + align:start position:0% +and you go far enough across the room +and now you get separation on the order + + align:start position:0% +and now you get separation on the order + + + align:start position:0% +and now you get separation on the order +of centimeters. and we record here. And + + align:start position:0% +of centimeters. and we record here. And + + + align:start position:0% +of centimeters. and we record here. And +this is the the blowup of what's on that + + align:start position:0% +this is the the blowup of what's on that + + + align:start position:0% +this is the the blowup of what's on that +photographic plate. And and this was + + align:start position:0% +photographic plate. And and this was + + + align:start position:0% +photographic plate. And and this was +painstaking work. Okay. What what you've + + align:start position:0% +painstaking work. Okay. What what you've + + + align:start position:0% +painstaking work. Okay. What what you've +got here is the photographic plate + + align:start position:0% +got here is the photographic plate + + + align:start position:0% +got here is the photographic plate +demonstrating a spread. First of all, + + align:start position:0% +demonstrating a spread. First of all, + + + align:start position:0% +demonstrating a spread. First of all, +that the the the glow is made up of + + align:start position:0% +that the the the glow is made up of + + + align:start position:0% +that the the the glow is made up of +constituents. There are distinct lines + + align:start position:0% +constituents. There are distinct lines + + + align:start position:0% +constituents. There are distinct lines +here. What what appears to the naked eye + + align:start position:0% +here. What what appears to the naked eye + + + align:start position:0% +here. What what appears to the naked eye +to be just glowing is actually + + align:start position:0% +to be just glowing is actually + + + align:start position:0% +to be just glowing is actually +superposition of different lines of + + align:start position:0% +superposition of different lines of + + + align:start position:0% +superposition of different lines of +distinct frequency. So you see this is + + align:start position:0% +distinct frequency. So you see this is + + + align:start position:0% +distinct frequency. So you see this is +quantized. It's + + align:start position:0% +quantized. It's + + + align:start position:0% +quantized. It's +quantized. And so he published his + + align:start position:0% +quantized. And so he published his + + + align:start position:0% +quantized. And so he published his +results around + + align:start position:0% +results around + + + align:start position:0% +results around +1853. And so they lay. So let's + + align:start position:0% +1853. And so they lay. So let's + + + align:start position:0% +1853. And so they lay. So let's +get + + align:start position:0% + + + + align:start position:0% + +1853. Let's get + + align:start position:0% +1853. Let's get + + + align:start position:0% +1853. Let's get +Angstrom up on the board here since he + + align:start position:0% +Angstrom up on the board here since he + + + align:start position:0% +Angstrom up on the board here since he +did the + + align:start position:0% +did the + + + align:start position:0% +did the +work. He was upsell in Sweden. So he he + + align:start position:0% +work. He was upsell in Sweden. So he he + + + align:start position:0% +work. He was upsell in Sweden. So he he +measured the line spectra line + + align:start position:0% + + + + align:start position:0% + +spectra of atomic + + align:start position:0% +spectra of atomic + + + align:start position:0% +spectra of atomic +hydrogen. By the way, your your text has + + align:start position:0% +hydrogen. By the way, your your text has + + + align:start position:0% +hydrogen. By the way, your your text has +a glaring error. The the label above + + align:start position:0% +a glaring error. The the label above + + + align:start position:0% +a glaring error. The the label above +this figure refers to H2. Take a take + + align:start position:0% +this figure refers to H2. Take a take + + + align:start position:0% +this figure refers to H2. Take a take +the fattest marking pen you have, + + align:start position:0% +the fattest marking pen you have, + + + align:start position:0% +the fattest marking pen you have, +scratch that out, and replace it with + + align:start position:0% +scratch that out, and replace it with + + + align:start position:0% +scratch that out, and replace it with +atomic hydrogen. You do not get this + + align:start position:0% +atomic hydrogen. You do not get this + + + align:start position:0% +atomic hydrogen. You do not get this +line from from uh hydrogen uh molecular + + align:start position:0% +line from from uh hydrogen uh molecular + + + align:start position:0% +line from from uh hydrogen uh molecular +hydrogen. So we've got the line spectra + + align:start position:0% +hydrogen. So we've got the line spectra + + + align:start position:0% +hydrogen. So we've got the line spectra +lying out there in the literature and + + align:start position:0% +lying out there in the literature and + + + align:start position:0% +lying out there in the literature and +people read the literature. They read + + align:start position:0% +people read the literature. They read + + + align:start position:0% +people read the literature. They read +and one of the person one of the people + + align:start position:0% +and one of the person one of the people + + + align:start position:0% +and one of the person one of the people +that was reading this literature was a + + align:start position:0% +that was reading this literature was a + + + align:start position:0% +that was reading this literature was a +school teacher a high school teacher + + align:start position:0% +school teacher a high school teacher + + + align:start position:0% +school teacher a high school teacher +who's teaching uh mathematics in Basil + + align:start position:0% +who's teaching uh mathematics in Basil + + + align:start position:0% +who's teaching uh mathematics in Basil +in Switzerland. So this man + + align:start position:0% +in Switzerland. So this man + + + align:start position:0% +in Switzerland. So this man +was he also had the initials JJ as in JJ + + align:start position:0% +was he also had the initials JJ as in JJ + + + align:start position:0% +was he also had the initials JJ as in JJ +Thompson. This is JJ Balmer and JJ + + align:start position:0% +Thompson. This is JJ Balmer and JJ + + + align:start position:0% +Thompson. This is JJ Balmer and JJ +Balmer in + + align:start position:0% + + + + align:start position:0% + +1885 playing with the numbers associated + + align:start position:0% +1885 playing with the numbers associated + + + align:start position:0% +1885 playing with the numbers associated +with the lines there. You notice how the + + align:start position:0% +with the lines there. You notice how the + + + align:start position:0% +with the lines there. You notice how the +lines are colored? Your book isn't + + align:start position:0% +lines are colored? Your book isn't + + + align:start position:0% +lines are colored? Your book isn't +colored. See, I colored them for you. + + align:start position:0% +colored. See, I colored them for you. + + + align:start position:0% +colored. See, I colored them for you. +You know, I care about you. I wanted to + + align:start position:0% +You know, I care about you. I wanted to + + + align:start position:0% +You know, I care about you. I wanted to +illustrate that there's representing + + align:start position:0% +illustrate that there's representing + + + align:start position:0% +illustrate that there's representing +different wavelengths in the visible, + + align:start position:0% +different wavelengths in the visible, + + + align:start position:0% +different wavelengths in the visible, +you know, and I and the doctor told me + + align:start position:0% +you know, and I and the doctor told me + + + align:start position:0% +you know, and I and the doctor told me +it's it's good for me to express my + + align:start position:0% +it's it's good for me to express my + + + align:start position:0% +it's it's good for me to express my +creative urges because it's so so I I + + align:start position:0% +creative urges because it's so so I I + + + align:start position:0% +creative urges because it's so so I I +got out my pen and and I did + + align:start position:0% +got out my pen and and I did + + + align:start position:0% +got out my pen and and I did +that. Where was I? Oh, so so what Balmer + + align:start position:0% +that. Where was I? Oh, so so what Balmer + + + align:start position:0% +that. Where was I? Oh, so so what Balmer +did Balmer he all he has is those four + + align:start position:0% +did Balmer he all he has is those four + + + align:start position:0% +did Balmer he all he has is those four +numbers. He's got the wavelengths of + + align:start position:0% +numbers. He's got the wavelengths of + + + align:start position:0% +numbers. He's got the wavelengths of +those four numbers and he's playing with + + align:start position:0% +those four numbers and he's playing with + + + align:start position:0% +those four numbers and he's playing with +those numbers. He's determined to make + + align:start position:0% +those numbers. He's determined to make + + + align:start position:0% +those numbers. He's determined to make +sense of those four numbers in some kind + + align:start position:0% +sense of those four numbers in some kind + + + align:start position:0% +sense of those four numbers in some kind +of a sequence and this is what he came + + align:start position:0% +of a sequence and this is what he came + + + align:start position:0% +of a sequence and this is what he came +up with finally he came up with the + + align:start position:0% +up with finally he came up with the + + + align:start position:0% +up with finally he came up with the +relationship + + align:start position:0% +relationship + + + align:start position:0% +relationship +that newbar which is called wave + + align:start position:0% +that newbar which is called wave + + + align:start position:0% +that newbar which is called wave +number wave number which in he found the + + align:start position:0% +number wave number which in he found the + + + align:start position:0% +number wave number which in he found the +reciprocal what he did he coined this + + align:start position:0% +reciprocal what he did he coined this + + + align:start position:0% +reciprocal what he did he coined this +but he found that by taking the + + align:start position:0% +but he found that by taking the + + + align:start position:0% +but he found that by taking the +reciprocal of the wavelengths you've got + + align:start position:0% +reciprocal of the wavelengths you've got + + + align:start position:0% +reciprocal of the wavelengths you've got +four numbers he took the reciprocals of + + align:start position:0% +four numbers he took the reciprocals of + + + align:start position:0% +four numbers he took the reciprocals of +those wavelengths he found that they fit + + align:start position:0% +those wavelengths he found that they fit + + + align:start position:0% +those wavelengths he found that they fit +Get a sequence, a numerical sequence 1 / + + align:start position:0% +Get a sequence, a numerical sequence 1 / + + + align:start position:0% +Get a sequence, a numerical sequence 1 / +2^2 - 1 / + + align:start position:0% +2^2 - 1 / + + + align:start position:0% +2^2 - 1 / +n^2 where n takes values 3 4 5 6 3 4 5 + + align:start position:0% +n^2 where n takes values 3 4 5 6 3 4 5 + + + align:start position:0% +n^2 where n takes values 3 4 5 6 3 4 5 +6 and there's a constant out here and + + align:start position:0% +6 and there's a constant out here and + + + align:start position:0% +6 and there's a constant out here and +the constant if we redo it in in modern + + align:start position:0% +the constant if we redo it in in modern + + + align:start position:0% +the constant if we redo it in in modern +SI units would take on the value of 1.1 + + align:start position:0% +SI units would take on the value of 1.1 + + + align:start position:0% +SI units would take on the value of 1.1 +* 10 + + align:start position:0% +* 10 + + + align:start position:0% +* 10 +7th reciprocal + + align:start position:0% +7th reciprocal + + + align:start position:0% +7th reciprocal +meters 1.1 * 10 7th uh reciprocal + + align:start position:0% +meters 1.1 * 10 7th uh reciprocal + + + align:start position:0% +meters 1.1 * 10 7th uh reciprocal +meters. + + align:start position:0% +meters. + + + align:start position:0% +meters. +So how does this support the bore model? + + align:start position:0% +So how does this support the bore model? + + + align:start position:0% +So how does this support the bore model? +Well, in order to answer that question, + + align:start position:0% +Well, in order to answer that question, + + + align:start position:0% +Well, in order to answer that question, +I've got to give you a little more + + align:start position:0% +I've got to give you a little more + + + align:start position:0% +I've got to give you a little more +background information. First thing I do + + align:start position:0% +background information. First thing I do + + + align:start position:0% +background information. First thing I do +is give you the understanding of what's + + align:start position:0% +is give you the understanding of what's + + + align:start position:0% +is give you the understanding of what's +the physics of the uh gas discharge + + align:start position:0% +the physics of the uh gas discharge + + + align:start position:0% +the physics of the uh gas discharge +tube. So let's let's take a look inside + + align:start position:0% +tube. So let's let's take a look inside + + + align:start position:0% +tube. So let's let's take a look inside +that tube. So let me redraw it. I'm + + align:start position:0% +that tube. So let me redraw it. I'm + + + align:start position:0% +that tube. So let me redraw it. I'm +going to redraw it horizontally. So this + + align:start position:0% +going to redraw it horizontally. So this + + + align:start position:0% +going to redraw it horizontally. So this +is a + + align:start position:0% +is a + + + align:start position:0% +is a +glass glass + + align:start position:0% +glass glass + + + align:start position:0% +glass glass +tube. There are some feedroughs here to + + align:start position:0% +tube. There are some feedroughs here to + + + align:start position:0% +tube. There are some feedroughs here to +allow electrodes to be potted. So this + + align:start position:0% +allow electrodes to be potted. So this + + + align:start position:0% +allow electrodes to be potted. So this +is this is these are gastight + + align:start position:0% +is this is these are gastight + + + align:start position:0% +is this is these are gastight +feedroughs. And these electrodes are + + align:start position:0% +feedroughs. And these electrodes are + + + align:start position:0% +feedroughs. And these electrodes are +then connected to a variable voltage + + align:start position:0% +then connected to a variable voltage + + + align:start position:0% +then connected to a variable voltage +power + + align:start position:0% +power + + + align:start position:0% +power +supply and it's possible to to change + + align:start position:0% +supply and it's possible to to change + + + align:start position:0% +supply and it's possible to to change +the voltage on this on the plates. And + + align:start position:0% +the voltage on this on the plates. And + + + align:start position:0% +the voltage on this on the plates. And +the way I've got this configured, uh, + + align:start position:0% +the way I've got this configured, uh, + + + align:start position:0% +the way I've got this configured, uh, +the left electrode is going to be + + align:start position:0% +the left electrode is going to be + + + align:start position:0% +the left electrode is going to be +charged negatively and the right + + align:start position:0% +charged negatively and the right + + + align:start position:0% +charged negatively and the right +electrode is going to be charged + + align:start position:0% +electrode is going to be charged + + + align:start position:0% +electrode is going to be charged +positively. So this will be the left + + align:start position:0% +positively. So this will be the left + + + align:start position:0% +positively. So this will be the left +electrode will be the cathode as I've + + align:start position:0% +electrode will be the cathode as I've + + + align:start position:0% +electrode will be the cathode as I've +configured it and the right electron the + + align:start position:0% +configured it and the right electron the + + + align:start position:0% +configured it and the right electron the +right electrode will be the anode. And + + align:start position:0% +right electrode will be the anode. And + + + align:start position:0% +right electrode will be the anode. And +um, what is inside the gas discharge + + align:start position:0% +um, what is inside the gas discharge + + + align:start position:0% +um, what is inside the gas discharge +tube is gas at low + + align:start position:0% +tube is gas at low + + + align:start position:0% +tube is gas at low +pressure. Gas at low pressure. + + align:start position:0% +pressure. Gas at low pressure. + + + align:start position:0% +pressure. Gas at low pressure. +As we increase the voltage, we get to a + + align:start position:0% +As we increase the voltage, we get to a + + + align:start position:0% +As we increase the voltage, we get to a +critical value at which it's possible to + + align:start position:0% +critical value at which it's possible to + + + align:start position:0% +critical value at which it's possible to +actually draw electrons across the gap. + + align:start position:0% +actually draw electrons across the gap. + + + align:start position:0% +actually draw electrons across the gap. +Electrons will actually boil off the + + align:start position:0% +Electrons will actually boil off the + + + align:start position:0% +Electrons will actually boil off the +cathode and accelerate across. You've + + align:start position:0% +cathode and accelerate across. You've + + + align:start position:0% +cathode and accelerate across. You've +got a positive electrode here and the + + align:start position:0% +got a positive electrode here and the + + + align:start position:0% +got a positive electrode here and the +electron is charged negatively. It will + + align:start position:0% +electron is charged negatively. It will + + + align:start position:0% +electron is charged negatively. It will +be drawn to the positive electrode. So, + + align:start position:0% +be drawn to the positive electrode. So, + + + align:start position:0% +be drawn to the positive electrode. So, +it will accelerate from rest, crash into + + align:start position:0% +it will accelerate from rest, crash into + + + align:start position:0% +it will accelerate from rest, crash into +the anode. + + align:start position:0% +the anode. + + + align:start position:0% +the anode. +So if we have nothing here, we see + + align:start position:0% +So if we have nothing here, we see + + + align:start position:0% +So if we have nothing here, we see +nothing. If we have too much gas in + + align:start position:0% +nothing. If we have too much gas in + + + align:start position:0% +nothing. If we have too much gas in +here, in other words, if the gas is at + + align:start position:0% +here, in other words, if the gas is at + + + align:start position:0% +here, in other words, if the gas is at +too high a pressure, the collisions with + + align:start position:0% +too high a pressure, the collisions with + + + align:start position:0% +too high a pressure, the collisions with +the gas molecules will consume the + + align:start position:0% +the gas molecules will consume the + + + align:start position:0% +the gas molecules will consume the +energy of the electrons and again, we'll + + align:start position:0% +energy of the electrons and again, we'll + + + align:start position:0% +energy of the electrons and again, we'll +see nothing. So if we get the the + + align:start position:0% +see nothing. So if we get the the + + + align:start position:0% +see nothing. So if we get the the +pressure in there just right, we'll + + align:start position:0% +pressure in there just right, we'll + + + align:start position:0% +pressure in there just right, we'll +allow for gas electron collisions, and + + align:start position:0% +allow for gas electron collisions, and + + + align:start position:0% +allow for gas electron collisions, and +then we get the the glow that ultimately + + align:start position:0% +then we get the the glow that ultimately + + + align:start position:0% +then we get the the glow that ultimately +was sent through the the slits. + + align:start position:0% +was sent through the the slits. + + + align:start position:0% +was sent through the the slits. +So that's + + align:start position:0% +So that's + + + align:start position:0% +So that's +the operation of the gas discharge tube. + + align:start position:0% +the operation of the gas discharge tube. + + + align:start position:0% +the operation of the gas discharge tube. +Now let's look at the physics. What's + + align:start position:0% +Now let's look at the physics. What's + + + align:start position:0% +Now let's look at the physics. What's +the energy of the electron? The energy + + align:start position:0% +the energy of the electron? The energy + + + align:start position:0% +the energy of the electron? The energy +of this electron accelerating from rest + + align:start position:0% +of this electron accelerating from rest + + + align:start position:0% +of this electron accelerating from rest +and crashing into the uh anode here. + + align:start position:0% +and crashing into the uh anode here. + + + align:start position:0% +and crashing into the uh anode here. +Well, it's going to be mechanical a half + + align:start position:0% +Well, it's going to be mechanical a half + + + align:start position:0% +Well, it's going to be mechanical a half +mv + + align:start position:0% +mv + + + align:start position:0% +mv +squared. And how about potential energy? + + align:start position:0% +squared. And how about potential energy? + + + align:start position:0% +squared. And how about potential energy? +It's it's not bound. It's a free + + align:start position:0% +It's it's not bound. It's a free + + + align:start position:0% +It's it's not bound. It's a free +electron. So there's no potential energy + + align:start position:0% +electron. So there's no potential energy + + + align:start position:0% +electron. So there's no potential energy +to be accounted for. So it's simply half + + align:start position:0% +to be accounted for. So it's simply half + + + align:start position:0% +to be accounted for. So it's simply half +MV^2. But I can equate the amount of + + align:start position:0% +MV^2. But I can equate the amount of + + + align:start position:0% +MV^2. But I can equate the amount of +energy, mechanical energy in the + + align:start position:0% +energy, mechanical energy in the + + + align:start position:0% +energy, mechanical energy in the +electron to the amount of electrical + + align:start position:0% +electron to the amount of electrical + + + align:start position:0% +electron to the amount of electrical +energy that was imparted through the + + align:start position:0% +energy that was imparted through the + + + align:start position:0% +energy that was imparted through the +electrodes. And the electrical energy is + + align:start position:0% +electrodes. And the electrical energy is + + + align:start position:0% +electrodes. And the electrical energy is +the product of the charge on the + + align:start position:0% +the product of the charge on the + + + align:start position:0% +the product of the charge on the +electrodes, excuse me, the charge on the + + align:start position:0% +electrodes, excuse me, the charge on the + + + align:start position:0% +electrodes, excuse me, the charge on the +electron times the voltage, which is the + + align:start position:0% +electron times the voltage, which is the + + + align:start position:0% +electron times the voltage, which is the +potential difference through which the + + align:start position:0% +potential difference through which the + + + align:start position:0% +potential difference through which the +electron was accelerated. + + align:start position:0% +electron was accelerated. + + + align:start position:0% +electron was accelerated. +And so this allows me to by increasing + + align:start position:0% +And so this allows me to by increasing + + + align:start position:0% +And so this allows me to by increasing +the voltage increase the energy on the + + align:start position:0% +the voltage increase the energy on the + + + align:start position:0% +the voltage increase the energy on the +electron. So you can see low voltage, + + align:start position:0% +electron. So you can see low voltage, + + + align:start position:0% +electron. So you can see low voltage, +low energy, high voltage, high energy. + + align:start position:0% +low energy, high voltage, high energy. + + + align:start position:0% +low energy, high voltage, high energy. +It's a linear function. And how about + + align:start position:0% +It's a linear function. And how about + + + align:start position:0% +It's a linear function. And how about +order of magnitude? Let's let's see + + align:start position:0% +order of magnitude? Let's let's see + + + align:start position:0% +order of magnitude? Let's let's see +suppose I took let's do everything unit. + + align:start position:0% +suppose I took let's do everything unit. + + + align:start position:0% +suppose I took let's do everything unit. +That's a good way. Let's say suppose I + + align:start position:0% +That's a good way. Let's say suppose I + + + align:start position:0% +That's a good way. Let's say suppose I +took what's the unit charge? The + + align:start position:0% +took what's the unit charge? The + + + align:start position:0% +took what's the unit charge? The +smallest charge I could put here would + + align:start position:0% +smallest charge I could put here would + + + align:start position:0% +smallest charge I could put here would +be 1.6 * 10 -19 kms. And what if I took + + align:start position:0% +be 1.6 * 10 -19 kms. And what if I took + + + align:start position:0% +be 1.6 * 10 -19 kms. And what if I took +a unit charge and I multiplied it times + + align:start position:0% +a unit charge and I multiplied it times + + + align:start position:0% +a unit charge and I multiplied it times +unit voltage 1 volt? Unit charge times + + align:start position:0% +unit voltage 1 volt? Unit charge times + + + align:start position:0% +unit voltage 1 volt? Unit charge times +unit voltage then would give me what? If + + align:start position:0% +unit voltage then would give me what? If + + + align:start position:0% +unit voltage then would give me what? If +I multiply these two what's the kum + + align:start position:0% +I multiply these two what's the kum + + + align:start position:0% +I multiply these two what's the kum +times a volt. You see here's the value + + align:start position:0% +times a volt. You see here's the value + + + align:start position:0% +times a volt. You see here's the value +of using SI units. SI units means + + align:start position:0% +of using SI units. SI units means + + + align:start position:0% +of using SI units. SI units means +everything goes in in SI. Everything + + align:start position:0% +everything goes in in SI. Everything + + + align:start position:0% +everything goes in in SI. Everything +comes out in SI. What's the energy unit + + align:start position:0% +comes out in SI. What's the energy unit + + + align:start position:0% +comes out in SI. What's the energy unit +in SI? The jewel. What is the unit of + + align:start position:0% +in SI? The jewel. What is the unit of + + + align:start position:0% +in SI? The jewel. What is the unit of +charge in Si? Kulom. What's the unit of + + align:start position:0% +charge in Si? Kulom. What's the unit of + + + align:start position:0% +charge in Si? Kulom. What's the unit of +potential difference? Volt with + + align:start position:0% +potential difference? Volt with + + + align:start position:0% +potential difference? Volt with +impunity. With impunity, if I use kulms + + align:start position:0% +impunity. With impunity, if I use kulms + + + align:start position:0% +impunity. With impunity, if I use kulms +here and volts here, I don't even think + + align:start position:0% +here and volts here, I don't even think + + + align:start position:0% +here and volts here, I don't even think +I write 1* 1.6. Even I can do that in my + + align:start position:0% +I write 1* 1.6. Even I can do that in my + + + align:start position:0% +I write 1* 1.6. Even I can do that in my +head. That's 1.6* + + align:start position:0% +head. That's 1.6* + + + align:start position:0% +head. That's 1.6* +10us19 and I write jewels. That's the + + align:start position:0% +10us19 and I write jewels. That's the + + + align:start position:0% +10us19 and I write jewels. That's the +power of having a rationalized system of + + align:start position:0% +power of having a rationalized system of + + + align:start position:0% +power of having a rationalized system of +units. So that's the good news. The bad + + align:start position:0% +units. So that's the good news. The bad + + + align:start position:0% +units. So that's the good news. The bad +news is I hate this number. Look it 1.6 + + align:start position:0% +news is I hate this number. Look it 1.6 + + + align:start position:0% +news is I hate this number. Look it 1.6 +6 * 10 - 18. We got 2.18 * 10, excuse + + align:start position:0% +6 * 10 - 18. We got 2.18 * 10, excuse + + + align:start position:0% +6 * 10 - 18. We got 2.18 * 10, excuse +me, 1.6 * 10 - 19. 2.18 * 10 - 18. Yap + + align:start position:0% +me, 1.6 * 10 - 19. 2.18 * 10 - 18. Yap + + + align:start position:0% +me, 1.6 * 10 - 19. 2.18 * 10 - 18. Yap +yap yap yap yap. Can't we get simple + + align:start position:0% +yap yap yap yap. Can't we get simple + + + align:start position:0% +yap yap yap yap. Can't we get simple +numbers like three, seven? Whatever + + align:start position:0% +numbers like three, seven? Whatever + + + align:start position:0% +numbers like three, seven? Whatever +happened to good old numbers? So I have + + align:start position:0% +happened to good old numbers? So I have + + + align:start position:0% +happened to good old numbers? So I have +an idea. Why don't we why don't we + + align:start position:0% +an idea. Why don't we why don't we + + + align:start position:0% +an idea. Why don't we why don't we +define a new unit of energy that is + + align:start position:0% +define a new unit of energy that is + + + align:start position:0% +define a new unit of energy that is +nearer to what we have to measure? And + + align:start position:0% +nearer to what we have to measure? And + + + align:start position:0% +nearer to what we have to measure? And +that was done. So what people did is + + align:start position:0% +that was done. So what people did is + + + align:start position:0% +that was done. So what people did is +they said let's define a unit of energy + + align:start position:0% +they said let's define a unit of energy + + + align:start position:0% +they said let's define a unit of energy +that represents a unit charge + + align:start position:0% +that represents a unit charge + + + align:start position:0% +that represents a unit charge +accelerated across a unit potential + + align:start position:0% +accelerated across a unit potential + + + align:start position:0% +accelerated across a unit potential +difference and let's call that the + + align:start position:0% +difference and let's call that the + + + align:start position:0% +difference and let's call that the +electron + + align:start position:0% +electron + + + align:start position:0% +electron +volt that's one electron volt the + + align:start position:0% +volt that's one electron volt the + + + align:start position:0% +volt that's one electron volt the +electron volt is not a unit of potential + + align:start position:0% +electron volt is not a unit of potential + + + align:start position:0% +electron volt is not a unit of potential +difference it's a unit of energy so now + + align:start position:0% +difference it's a unit of energy so now + + + align:start position:0% +difference it's a unit of energy so now +this is one eV so now you can see 2.18* + + align:start position:0% +this is one eV so now you can see 2.18* + + + align:start position:0% +this is one eV so now you can see 2.18* +10 - 18 jewels can be 13.6 6 EV. Now I I + + align:start position:0% +10 - 18 jewels can be 13.6 6 EV. Now I I + + + align:start position:0% +10 - 18 jewels can be 13.6 6 EV. Now I I +don't have to, you know, fill my head + + align:start position:0% +don't have to, you know, fill my head + + + align:start position:0% +don't have to, you know, fill my head +with a 2.18 * 10us + + align:start position:0% +with a 2.18 * 10us + + + align:start position:0% +with a 2.18 * 10us +18.6. That's a cool number. I can + + align:start position:0% +18.6. That's a cool number. I can + + + align:start position:0% +18.6. That's a cool number. I can +remember + + align:start position:0% +remember + + + align:start position:0% +remember +that. All right. So that's how that + + align:start position:0% +that. All right. So that's how that + + + align:start position:0% +that. All right. So that's how that +works. By the way, um this is the + + align:start position:0% +works. By the way, um this is the + + + align:start position:0% +works. By the way, um this is the +cathode. And we have a beam. We have a + + align:start position:0% +cathode. And we have a beam. We have a + + + align:start position:0% +cathode. And we have a beam. We have a +beam. It's an electron + + align:start position:0% +beam. It's an electron + + + align:start position:0% +beam. It's an electron +beam. Electron beam. in in the in the + + align:start position:0% +beam. Electron beam. in in the in the + + + align:start position:0% +beam. Electron beam. in in the in the +1890s, the latter part of the 19th + + align:start position:0% +1890s, the latter part of the 19th + + + align:start position:0% +1890s, the latter part of the 19th +century, a very fashionable word was + + align:start position:0% +century, a very fashionable word was + + + align:start position:0% +century, a very fashionable word was +ray because it came from optics. You + + align:start position:0% +ray because it came from optics. You + + + align:start position:0% +ray because it came from optics. You +know, the rays rays of sunlight and so + + align:start position:0% +know, the rays rays of sunlight and so + + + align:start position:0% +know, the rays rays of sunlight and so +on. And in fact, even when we first + + align:start position:0% +on. And in fact, even when we first + + + align:start position:0% +on. And in fact, even when we first +started pulling synthetic fiber, the + + align:start position:0% +started pulling synthetic fiber, the + + + align:start position:0% +started pulling synthetic fiber, the +first synthetic fiber cellulose was + + align:start position:0% +first synthetic fiber cellulose was + + + align:start position:0% +first synthetic fiber cellulose was +referred to as rayon because it looked + + align:start position:0% +referred to as rayon because it looked + + + align:start position:0% +referred to as rayon because it looked +like a ray that was being pulled. So + + align:start position:0% +like a ray that was being pulled. So + + + align:start position:0% +like a ray that was being pulled. So +this rather than calling this an + + align:start position:0% +this rather than calling this an + + + align:start position:0% +this rather than calling this an +electron beam, this was called a cathode + + align:start position:0% +electron beam, this was called a cathode + + + align:start position:0% +electron beam, this was called a cathode +ray. This was called a cathode ray. And + + align:start position:0% +ray. This was called a cathode ray. And + + + align:start position:0% +ray. This was called a cathode ray. And +this is a tube at low pressure. And if I + + align:start position:0% +this is a tube at low pressure. And if I + + + align:start position:0% +this is a tube at low pressure. And if I +evacuate it, I have a cathode ray tube. + + align:start position:0% +evacuate it, I have a cathode ray tube. + + + align:start position:0% +evacuate it, I have a cathode ray tube. +And in fact, instead of having just a an + + align:start position:0% +And in fact, instead of having just a an + + + align:start position:0% +And in fact, instead of having just a an +electrode here, what I could do is I + + align:start position:0% +electrode here, what I could do is I + + + align:start position:0% +electrode here, what I could do is I +could have an electrode that's that's uh + + align:start position:0% +could have an electrode that's that's uh + + + align:start position:0% +could have an electrode that's that's uh +has that's hollow. And then I could put + + align:start position:0% +has that's hollow. And then I could put + + + align:start position:0% +has that's hollow. And then I could put +a flat end here, and I could put + + align:start position:0% +a flat end here, and I could put + + + align:start position:0% +a flat end here, and I could put +phosphorus here. And then I could put a + + align:start position:0% +phosphorus here. And then I could put a + + + align:start position:0% +phosphorus here. And then I could put a +couple of uh plates and I could raster + + align:start position:0% +couple of uh plates and I could raster + + + align:start position:0% +couple of uh plates and I could raster +the beam so that when I'm looking here, + + align:start position:0% +the beam so that when I'm looking here, + + + align:start position:0% +the beam so that when I'm looking here, +the beam goes back and forth about 80 + + align:start position:0% +the beam goes back and forth about 80 + + + align:start position:0% +the beam goes back and forth about 80 +times a second and the phosphorus glow + + align:start position:0% +times a second and the phosphorus glow + + + align:start position:0% +times a second and the phosphorus glow +and I can be watching um uh science + + align:start position:0% + + + + align:start position:0% + +documentary. All right. The other thing + + align:start position:0% +documentary. All right. The other thing + + + align:start position:0% +documentary. All right. The other thing +I have to teach you is matter energy + + align:start position:0% +I have to teach you is matter energy + + + align:start position:0% +I have to teach you is matter energy +interaction so that we can see how the + + align:start position:0% +interaction so that we can see how the + + + align:start position:0% +interaction so that we can see how the +Balmer + + align:start position:0% +Balmer + + + align:start position:0% +Balmer +series validates the bore model. So + + align:start position:0% +series validates the bore model. So + + + align:start position:0% +series validates the bore model. So +there's one more thing you need to know + + align:start position:0% +there's one more thing you need to know + + + align:start position:0% +there's one more thing you need to know +and I'm going to put up this energy + + align:start position:0% +and I'm going to put up this energy + + + align:start position:0% +and I'm going to put up this energy +level diagram again. So this is uh this + + align:start position:0% +level diagram again. So this is uh this + + + align:start position:0% +level diagram again. So this is uh this +is + + align:start position:0% +is + + + align:start position:0% +is +infinity. Let's call this three 2 one. + + align:start position:0% +infinity. Let's call this three 2 one. + + + align:start position:0% +infinity. Let's call this three 2 one. +So this is E1 ground state E2 E3 and so + + align:start position:0% +So this is E1 ground state E2 E3 and so + + + align:start position:0% +So this is E1 ground state E2 E3 and so +on. This is zero. + + align:start position:0% +on. This is zero. + + + align:start position:0% +on. This is zero. +Okay, so let's let's look at the + + align:start position:0% +Okay, so let's let's look at the + + + align:start position:0% +Okay, so let's let's look at the +energetics of one of those electrons + + align:start position:0% +energetics of one of those electrons + + + align:start position:0% +energetics of one of those electrons +crashing into a hydrogen atom inside the + + align:start position:0% +crashing into a hydrogen atom inside the + + + align:start position:0% +crashing into a hydrogen atom inside the +gas tube. So here's here's an electron + + align:start position:0% +gas tube. So here's here's an electron + + + align:start position:0% +gas tube. So here's here's an electron +and I'm going to let this arrow somehow + + align:start position:0% +and I'm going to let this arrow somehow + + + align:start position:0% +and I'm going to let this arrow somehow +indicate the + + align:start position:0% + + + + align:start position:0% + +um value of the incident energy and this + + align:start position:0% +um value of the incident energy and this + + + align:start position:0% +um value of the incident energy and this +is this is the this I'm saying electron + + align:start position:0% +is this is the this I'm saying electron + + + align:start position:0% +is this is the this I'm saying electron +but more generally it's applies to any + + align:start position:0% +but more generally it's applies to any + + + align:start position:0% +but more generally it's applies to any +incident particle later on we could do + + align:start position:0% +incident particle later on we could do + + + align:start position:0% +incident particle later on we could do +this with a proton we could do it with a + + align:start position:0% +this with a proton we could do it with a + + + align:start position:0% +this with a proton we could do it with a +um with a neutron uh we could do saw + + align:start position:0% +um with a neutron uh we could do saw + + + align:start position:0% +um with a neutron uh we could do saw +Rutherford used alpha particles we could + + align:start position:0% +Rutherford used alpha particles we could + + + align:start position:0% +Rutherford used alpha particles we could +use argon ion. There's all kinds of + + align:start position:0% +use argon ion. There's all kinds of + + + align:start position:0% +use argon ion. There's all kinds of +different ways of bombarding um in this + + align:start position:0% +different ways of bombarding um in this + + + align:start position:0% +different ways of bombarding um in this +case hydrogen gas. Now, if this incident + + align:start position:0% +case hydrogen gas. Now, if this incident + + + align:start position:0% +case hydrogen gas. Now, if this incident +energy is great enough, it'll take an + + align:start position:0% +energy is great enough, it'll take an + + + align:start position:0% +energy is great enough, it'll take an +electron out of the ground state and + + align:start position:0% +electron out of the ground state and + + + align:start position:0% +electron out of the ground state and +promote it. But the electron cannot + + align:start position:0% +promote it. But the electron cannot + + + align:start position:0% +promote it. But the electron cannot +reside anywhere except in one of these + + align:start position:0% +reside anywhere except in one of these + + + align:start position:0% +reside anywhere except in one of these +quantized states. So suppose suppose the + + align:start position:0% +quantized states. So suppose suppose the + + + align:start position:0% +quantized states. So suppose suppose the +E + + align:start position:0% +E + + + align:start position:0% +E +incident suppose E incident is greater + + align:start position:0% +incident suppose E incident is greater + + + align:start position:0% +incident suppose E incident is greater +than the energy in the transition going + + align:start position:0% +than the energy in the transition going + + + align:start position:0% +than the energy in the transition going +from ground state to N=2. What will + + align:start position:0% +from ground state to N=2. What will + + + align:start position:0% +from ground state to N=2. What will +happen? That energy will be absorbed by + + align:start position:0% +happen? That energy will be absorbed by + + + align:start position:0% +happen? That energy will be absorbed by +the hydrogen atom. The electron will + + align:start position:0% +the hydrogen atom. The electron will + + + align:start position:0% +the hydrogen atom. The electron will +rise from n=1 to n=2 and that amount of + + align:start position:0% +rise from n=1 to n=2 and that amount of + + + align:start position:0% +rise from n=1 to n=2 and that amount of +energy will be subtracted. And then over + + align:start position:0% +energy will be subtracted. And then over + + + align:start position:0% +energy will be subtracted. And then over +here this electron will continue. And + + align:start position:0% +here this electron will continue. And + + + align:start position:0% +here this electron will continue. And +I've purposely made the arrow shorter to + + align:start position:0% +I've purposely made the arrow shorter to + + + align:start position:0% +I've purposely made the arrow shorter to +indicate that it has been slowed because + + align:start position:0% +indicate that it has been slowed because + + + align:start position:0% +indicate that it has been slowed because +we're going to argue its mass didn't + + align:start position:0% +we're going to argue its mass didn't + + + align:start position:0% +we're going to argue its mass didn't +change. So the only way to change its + + align:start position:0% +change. So the only way to change its + + + align:start position:0% +change. So the only way to change its +energy is to change its velocity. So + + align:start position:0% +energy is to change its velocity. So + + + align:start position:0% +energy is to change its velocity. So +this will be now the the uh scattered. + + align:start position:0% +this will be now the the uh scattered. + + + align:start position:0% +this will be now the the uh scattered. +We call this it's scattered now. It's + + align:start position:0% +We call this it's scattered now. It's + + + align:start position:0% +We call this it's scattered now. It's +interacted. This is the scattered + + align:start position:0% +interacted. This is the scattered + + + align:start position:0% +interacted. This is the scattered +particle. But it doesn't end there. So + + align:start position:0% +particle. But it doesn't end there. So + + + align:start position:0% +particle. But it doesn't end there. So +how much energy is there? If this is let + + align:start position:0% +how much energy is there? If this is let + + + align:start position:0% +how much energy is there? If this is let +this represent the total energy of the + + align:start position:0% +this represent the total energy of the + + + align:start position:0% +this represent the total energy of the +of the + + align:start position:0% +of the + + + align:start position:0% +of the +incident electron and if that's the + + align:start position:0% +incident electron and if that's the + + + align:start position:0% +incident electron and if that's the +energy to go from n equals 1 to n equals + + align:start position:0% +energy to go from n equals 1 to n equals + + + align:start position:0% +energy to go from n equals 1 to n equals +2 then this is the amount of energy + + align:start position:0% +2 then this is the amount of energy + + + align:start position:0% +2 then this is the amount of energy +that's going to be left as kinetic + + align:start position:0% +that's going to be left as kinetic + + + align:start position:0% +that's going to be left as kinetic +energy of the electron. It's like an + + align:start position:0% +energy of the electron. It's like an + + + align:start position:0% +energy of the electron. It's like an +elastic collision between billiard + + align:start position:0% +elastic collision between billiard + + + align:start position:0% +elastic collision between billiard +balls. You've seen these things but it + + align:start position:0% +balls. You've seen these things but it + + + align:start position:0% +balls. You've seen these things but it +doesn't end there because the electron + + align:start position:0% +doesn't end there because the electron + + + align:start position:0% +doesn't end there because the electron +is sitting up here at n equals 2 very + + align:start position:0% +is sitting up here at n equals 2 very + + + align:start position:0% +is sitting up here at n equals 2 very +nervous because there's a lower energy + + align:start position:0% +nervous because there's a lower energy + + + align:start position:0% +nervous because there's a lower energy +state and there's a colombic attraction + + align:start position:0% +state and there's a colombic attraction + + + align:start position:0% +state and there's a colombic attraction +of the nucleus. So what happens you know + + align:start position:0% +of the nucleus. So what happens you know + + + align:start position:0% +of the nucleus. So what happens you know +almost instantaneously after the + + align:start position:0% +almost instantaneously after the + + + align:start position:0% +almost instantaneously after the +collision the electron up here falls + + align:start position:0% +collision the electron up here falls + + + align:start position:0% +collision the electron up here falls +back down and when it falls back down + + align:start position:0% +back down and when it falls back down + + + align:start position:0% +back down and when it falls back down +that energy is given off and it's given + + align:start position:0% +that energy is given off and it's given + + + align:start position:0% +that energy is given off and it's given +off in the form of a + + align:start position:0% +off in the form of a + + + align:start position:0% +off in the form of a +photon. It's given off in the form of a + + align:start position:0% +photon. It's given off in the form of a + + + align:start position:0% +photon. It's given off in the form of a +photon. And what's the energy of that + + align:start position:0% +photon. And what's the energy of that + + + align:start position:0% +photon. And what's the energy of that +photon? Well the energy of the + + align:start position:0% +photon? Well the energy of the + + + align:start position:0% +photon? Well the energy of the +photon we know from plunk is H new which + + align:start position:0% +photon we know from plunk is H new which + + + align:start position:0% +photon we know from plunk is H new which +is H C over lambda. + + align:start position:0% + + + + align:start position:0% + +So now I've got lambdas associated with + + align:start position:0% +So now I've got lambdas associated with + + + align:start position:0% +So now I've got lambdas associated with +transitions between energy levels in + + align:start position:0% +transitions between energy levels in + + + align:start position:0% +transitions between energy levels in +atomic + + align:start position:0% +atomic + + + align:start position:0% +atomic +hydrogen. Gee, I wonder if I could come + + align:start position:0% +hydrogen. Gee, I wonder if I could come + + + align:start position:0% +hydrogen. Gee, I wonder if I could come +up with a set of + + align:start position:0% +up with a set of + + + align:start position:0% +up with a set of +transitions occurring inside atomic + + align:start position:0% +transitions occurring inside atomic + + + align:start position:0% +transitions occurring inside atomic +hydrogen that just might match what + + align:start position:0% +hydrogen that just might match what + + + align:start position:0% +hydrogen that just might match what +Angstrom measured back in 1853. + + align:start position:0% +Angstrom measured back in 1853. + + + align:start position:0% +Angstrom measured back in 1853. +So that's going to be the the challenge. + + align:start position:0% +So that's going to be the the challenge. + + + align:start position:0% +So that's going to be the the challenge. +That's going to be the challenge. The + + align:start position:0% +That's going to be the challenge. The + + + align:start position:0% +That's going to be the challenge. The +interesting thing here is + + align:start position:0% +interesting thing here is + + + align:start position:0% +interesting thing here is +that I can change the incident velocity + + align:start position:0% +that I can change the incident velocity + + + align:start position:0% +that I can change the incident velocity +continuously, right? This is + + align:start position:0% +continuously, right? This is + + + align:start position:0% +continuously, right? This is +continuously variable because I can vary + + align:start position:0% +continuously variable because I can vary + + + align:start position:0% +continuously variable because I can vary +voltage + + align:start position:0% +voltage + + + align:start position:0% +voltage +continuously. Change the voltage, I + + align:start position:0% +continuously. Change the voltage, I + + + align:start position:0% +continuously. Change the voltage, I +change the incident energy. What about + + align:start position:0% +change the incident energy. What about + + + align:start position:0% +change the incident energy. What about +the energy of the emitted photons? Are + + align:start position:0% +the energy of the emitted photons? Are + + + align:start position:0% +the energy of the emitted photons? Are +they continuously variable? No, they are + + align:start position:0% +they continuously variable? No, they are + + + align:start position:0% +they continuously variable? No, they are +discrete. They're discreet. And + + align:start position:0% +discrete. They're discreet. And + + + align:start position:0% +discrete. They're discreet. And +furthermore, they're characteristic of + + align:start position:0% +furthermore, they're characteristic of + + + align:start position:0% +furthermore, they're characteristic of +the target gas element. So, let's say I + + align:start position:0% +the target gas element. So, let's say I + + + align:start position:0% +the target gas element. So, let's say I +got up late and I'm racing to get to + + align:start position:0% +got up late and I'm racing to get to + + + align:start position:0% +got up late and I'm racing to get to +class and I just burst in now and I look + + align:start position:0% +class and I just burst in now and I look + + + align:start position:0% +class and I just burst in now and I look +up there and I go, that's atomic + + align:start position:0% +up there and I go, that's atomic + + + align:start position:0% +up there and I go, that's atomic +hydrogen. because only atomic hydrogen + + align:start position:0% +hydrogen. because only atomic hydrogen + + + align:start position:0% +hydrogen. because only atomic hydrogen +has that set of + + align:start position:0% +has that set of + + + align:start position:0% +has that set of +lines which means I could then take the + + align:start position:0% +lines which means I could then take the + + + align:start position:0% +lines which means I could then take the +spectra of gasphase species and use that + + align:start position:0% +spectra of gasphase species and use that + + + align:start position:0% +spectra of gasphase species and use that +information to + + align:start position:0% +information to + + + align:start position:0% +information to +identify. So this is now a technique of + + align:start position:0% +identify. So this is now a technique of + + + align:start position:0% +identify. So this is now a technique of +analysis. I could take an unknown gas + + align:start position:0% +analysis. I could take an unknown gas + + + align:start position:0% +analysis. I could take an unknown gas +and put it in and measure it and then + + align:start position:0% +and put it in and measure it and then + + + align:start position:0% +and put it in and measure it and then +say wow those are the lines that are + + align:start position:0% +say wow those are the lines that are + + + align:start position:0% +say wow those are the lines that are +characteristic of sodium. This gee, have + + align:start position:0% +characteristic of sodium. This gee, have + + + align:start position:0% +characteristic of sodium. This gee, have +you ever wondered how they know the + + align:start position:0% +you ever wondered how they know the + + + align:start position:0% +you ever wondered how they know the +composition of stars that are light + + align:start position:0% +composition of stars that are light + + + align:start position:0% +composition of stars that are light +years away? Do they get sample bottles + + align:start position:0% +years away? Do they get sample bottles + + + align:start position:0% +years away? Do they get sample bottles +coming in? How do they get that + + align:start position:0% +coming in? How do they get that + + + align:start position:0% +coming in? How do they get that +information? You What is a star if not + + align:start position:0% +information? You What is a star if not + + + align:start position:0% +information? You What is a star if not +just a giant gas bottle + + align:start position:0% +just a giant gas bottle + + + align:start position:0% +just a giant gas bottle +containerless? It's + + align:start position:0% +containerless? It's + + + align:start position:0% +containerless? It's +glowing. And why is it glowing? It's + + align:start position:0% +glowing. And why is it glowing? It's + + + align:start position:0% +glowing. And why is it glowing? It's +glowing because electrons are excited. + + align:start position:0% +glowing because electrons are excited. + + + align:start position:0% +glowing because electrons are excited. +and they're excited and they're jumping + + align:start position:0% +and they're excited and they're jumping + + + align:start position:0% +and they're excited and they're jumping +up and down and they're emitting, but + + align:start position:0% +up and down and they're emitting, but + + + align:start position:0% +up and down and they're emitting, but +they're just not emitting anything. I + + align:start position:0% +they're just not emitting anything. I + + + align:start position:0% +they're just not emitting anything. I +mean, why are some stars this color and + + align:start position:0% +mean, why are some stars this color and + + + align:start position:0% +mean, why are some stars this color and +some stars that color? Somebody painted + + align:start position:0% +some stars that color? Somebody painted + + + align:start position:0% +some stars that color? Somebody painted +them that way. They're different because + + align:start position:0% +them that way. They're different because + + + align:start position:0% +them that way. They're different because +they got different compositions. So, you + + align:start position:0% +they got different compositions. So, you + + + align:start position:0% +they got different compositions. So, you +could use this in order to identify the + + align:start position:0% +could use this in order to identify the + + + align:start position:0% +could use this in order to identify the +contents of + + align:start position:0% +contents of + + + align:start position:0% +contents of +stars, all of + + align:start position:0% +stars, all of + + + align:start position:0% +stars, all of +this. + + align:start position:0% +this. + + + align:start position:0% +this. +So, what did Boore do? I want to tell + + align:start position:0% +So, what did Boore do? I want to tell + + + align:start position:0% +So, what did Boore do? I want to tell +you a couple more Boore stories. Boore, + + align:start position:0% +you a couple more Boore stories. Boore, + + + align:start position:0% +you a couple more Boore stories. Boore, +the guy was great. Okay, so here's what + + align:start position:0% +the guy was great. Okay, so here's what + + + align:start position:0% +the guy was great. Okay, so here's what +happens. Here's a story. Capstone of + + align:start position:0% +happens. Here's a story. Capstone of + + + align:start position:0% +happens. Here's a story. Capstone of +Bor's work on the Balmer + + align:start position:0% + + + + align:start position:0% + +formula. Let me simply tell you that in + + align:start position:0% +formula. Let me simply tell you that in + + + align:start position:0% +formula. Let me simply tell you that in +time I'm going to show you that this + + align:start position:0% +time I'm going to show you that this + + + align:start position:0% +time I'm going to show you that this +formula is inconsistent with the bore + + align:start position:0% +formula is inconsistent with the bore + + + align:start position:0% +formula is inconsistent with the bore +model. You see that at the beginning of + + align:start position:0% +model. You see that at the beginning of + + + align:start position:0% +model. You see that at the beginning of +next lecture. So in 1896, Charles + + align:start position:0% +next lecture. So in 1896, Charles + + + align:start position:0% +next lecture. So in 1896, Charles +Pickering from Harvard found a series of + + align:start position:0% +Pickering from Harvard found a series of + + + align:start position:0% +Pickering from Harvard found a series of +lines in starlight which he attributed + + align:start position:0% +lines in starlight which he attributed + + + align:start position:0% +lines in starlight which he attributed +to hydrogen even though they did not fit + + align:start position:0% +to hydrogen even though they did not fit + + + align:start position:0% +to hydrogen even though they did not fit +Balmer. They were off by a factor + + align:start position:0% +Balmer. They were off by a factor + + + align:start position:0% +Balmer. They were off by a factor +of four. Now, what do you know about + + align:start position:0% +of four. Now, what do you know about + + + align:start position:0% +of four. Now, what do you know about +energy? Already from this class, if I + + align:start position:0% +energy? Already from this class, if I + + + align:start position:0% +energy? Already from this class, if I +told you that I gave you energies in + + align:start position:0% +told you that I gave you energies in + + + align:start position:0% +told you that I gave you energies in +some spectrum, but they were off by a + + align:start position:0% +some spectrum, but they were off by a + + + align:start position:0% +some spectrum, but they were off by a +factor of four, what would you + + align:start position:0% +factor of four, what would you + + + align:start position:0% +factor of four, what would you +think? It's + + align:start position:0% +think? It's + + + align:start position:0% +think? It's +probably maybe the Z is wrong. So, even + + align:start position:0% +probably maybe the Z is wrong. So, even + + + align:start position:0% +probably maybe the Z is wrong. So, even +though the lines were wrong, he says, + + align:start position:0% +though the lines were wrong, he says, + + + align:start position:0% +though the lines were wrong, he says, +"No, it's + + align:start position:0% +"No, it's + + + align:start position:0% +"No, it's +hydrogen." So, Bore says, "No, no, it's + + align:start position:0% +hydrogen." So, Bore says, "No, no, it's + + + align:start position:0% +hydrogen." So, Bore says, "No, no, it's +not hydrogen, it's helium. That star has + + align:start position:0% +not hydrogen, it's helium. That star has + + + align:start position:0% +not hydrogen, it's helium. That star has +got ionized helium. Helium plus Z equ= 2 + + align:start position:0% +got ionized helium. Helium plus Z equ= 2 + + + align:start position:0% +got ionized helium. Helium plus Z equ= 2 +energy will be four times more intense. + + align:start position:0% +energy will be four times more intense. + + + align:start position:0% +energy will be four times more intense. +So Pickering was nasty so and he said ah + + align:start position:0% +So Pickering was nasty so and he said ah + + + align:start position:0% +So Pickering was nasty so and he said ah +you're wrong because in fact it's + + align:start position:0% +you're wrong because in fact it's + + + align:start position:0% +you're wrong because in fact it's +4.0016 and the six is greater than what + + align:start position:0% +4.0016 and the six is greater than what + + + align:start position:0% +4.0016 and the six is greater than what +I would have as experimental error. So + + align:start position:0% +I would have as experimental error. So + + + align:start position:0% +I would have as experimental error. So +your theory is wrong. So Boris says oh + + align:start position:0% +your theory is wrong. So Boris says oh + + + align:start position:0% +your theory is wrong. So Boris says oh +yeah. So he goes back and he redoes the + + align:start position:0% +yeah. So he goes back and he redoes the + + + align:start position:0% +yeah. So he goes back and he redoes the +calculation only in this case he says + + align:start position:0% +calculation only in this case he says + + + align:start position:0% +calculation only in this case he says +all right what I'm going to do is I'm + + align:start position:0% +all right what I'm going to do is I'm + + + align:start position:0% +all right what I'm going to do is I'm +going to redo the calculation for helium + + align:start position:0% +going to redo the calculation for helium + + + align:start position:0% +going to redo the calculation for helium +but I'm going to consider not just the + + align:start position:0% +but I'm going to consider not just the + + + align:start position:0% +but I'm going to consider not just the +mass of the electron but the reduced + + align:start position:0% +mass of the electron but the reduced + + + align:start position:0% +mass of the electron but the reduced +mass of the system. So I'll take into + + align:start position:0% +mass of the system. So I'll take into + + + align:start position:0% +mass of the system. So I'll take into +account that there is some contribution + + align:start position:0% +account that there is some contribution + + + align:start position:0% +account that there is some contribution +of both the nucleus and the electron and + + align:start position:0% +of both the nucleus and the electron and + + + align:start position:0% +of both the nucleus and the electron and +he gets you're you're absolutely right + + align:start position:0% +he gets you're you're absolutely right + + + align:start position:0% +he gets you're you're absolutely right +it's not four it's 4.00163 + + align:start position:0% +it's not four it's 4.00163 + + + align:start position:0% +it's not four it's 4.00163 +0163 take that right so what you have is + + align:start position:0% +0163 take that right so what you have is + + + align:start position:0% +0163 take that right so what you have is +with a simple calculation five + + align:start position:0% +with a simple calculation five + + + align:start position:0% +with a simple calculation five +significant figures five significant + + align:start position:0% +significant figures five significant + + + align:start position:0% +significant figures five significant +figures that shut him + + align:start position:0% +figures that shut him + + + align:start position:0% +figures that shut him +up now to just show it doesn't end more + + align:start position:0% +up now to just show it doesn't end more + + + align:start position:0% +up now to just show it doesn't end more +more nonsense at Harvard this is Cecilia + + align:start position:0% +more nonsense at Harvard this is Cecilia + + + align:start position:0% +more nonsense at Harvard this is Cecilia +Payne first woman graduate student in + + align:start position:0% +Payne first woman graduate student in + + + align:start position:0% +Payne first woman graduate student in +astronomy first PhD in astronomy first + + align:start position:0% +astronomy first PhD in astronomy first + + + align:start position:0% +astronomy first PhD in astronomy first +woman to receive tenure at Harvard she + + align:start position:0% +woman to receive tenure at Harvard she + + + align:start position:0% +woman to receive tenure at Harvard she +was awarded tenure in 193 38 denied a + + align:start position:0% +was awarded tenure in 193 38 denied a + + + align:start position:0% +was awarded tenure in 193 38 denied a +professorship for 18 years. And when she + + align:start position:0% +professorship for 18 years. And when she + + + align:start position:0% +professorship for 18 years. And when she +presented her PhD thesis, she was the + + align:start position:0% +presented her PhD thesis, she was the + + + align:start position:0% +presented her PhD thesis, she was the +one that determined that the sun is made + + align:start position:0% +one that determined that the sun is made + + + align:start position:0% +one that determined that the sun is made +dominantly of hydrogen, not iron, the + + align:start position:0% +dominantly of hydrogen, not iron, the + + + align:start position:0% +dominantly of hydrogen, not iron, the +way most the old goats thought because + + align:start position:0% +way most the old goats thought because + + + align:start position:0% +way most the old goats thought because +the earth is made of iron. Heaven knows + + align:start position:0% +the earth is made of iron. Heaven knows + + + align:start position:0% +the earth is made of iron. Heaven knows +everything is made of the same stuff, + + align:start position:0% +everything is made of the same stuff, + + + align:start position:0% +everything is made of the same stuff, +right? All heavenly bodies, even though + + align:start position:0% +right? All heavenly bodies, even though + + + align:start position:0% +right? All heavenly bodies, even though +the sun is glowing and the earth isn't, + + align:start position:0% +the sun is glowing and the earth isn't, + + + align:start position:0% +the sun is glowing and the earth isn't, +but oh, they must be they must be made + + align:start position:0% +but oh, they must be they must be made + + + align:start position:0% +but oh, they must be they must be made +of the same thing. And after all, we're + + align:start position:0% +of the same thing. And after all, we're + + + align:start position:0% +of the same thing. And after all, we're +Harvard, so we know. So + + align:start position:0% +Harvard, so we know. So + + + align:start position:0% +Harvard, so we know. So +So here's what she did. She was + + align:start position:0% +So here's what she did. She was + + + align:start position:0% +So here's what she did. She was +festidious. Look at this. What do you + + align:start position:0% +festidious. Look at this. What do you + + + align:start position:0% +festidious. Look at this. What do you +see there? Well, you see iron, but you + + align:start position:0% +see there? Well, you see iron, but you + + + align:start position:0% +see there? Well, you see iron, but you +know, this is misspelled. So, yeah, + + align:start position:0% +know, this is misspelled. So, yeah, + + + align:start position:0% +know, this is misspelled. So, yeah, +you're making an excuses. Ah, the + + align:start position:0% +you're making an excuses. Ah, the + + + align:start position:0% +you're making an excuses. Ah, the +detector isn't working. You know, this + + align:start position:0% +detector isn't working. You know, this + + + align:start position:0% +detector isn't working. You know, this +is the noisy system. So, that's what + + align:start position:0% +is the noisy system. So, that's what + + + align:start position:0% +is the noisy system. So, that's what +everybody else is doing. But what + + align:start position:0% +everybody else is doing. But what + + + align:start position:0% +everybody else is doing. But what +Cecilia is doing is she's saying, I got + + align:start position:0% +Cecilia is doing is she's saying, I got + + + align:start position:0% +Cecilia is doing is she's saying, I got +to keep looking. I need a I need a + + align:start position:0% +to keep looking. I need a I need a + + + align:start position:0% +to keep looking. I need a I need a +consistent I need a consistent uh + + align:start position:0% +consistent I need a consistent uh + + + align:start position:0% +consistent I need a consistent uh +picture. So, this is what spectroscopy + + align:start position:0% +picture. So, this is what spectroscopy + + + align:start position:0% +picture. So, this is what spectroscopy +is. Spectroscopy is how you go and look + + align:start position:0% +is. Spectroscopy is how you go and look + + + align:start position:0% +is. Spectroscopy is how you go and look +at patterns, not just individual lines. + + align:start position:0% +at patterns, not just individual lines. + + + align:start position:0% +at patterns, not just individual lines. +So when she defended her thesis, she was + + align:start position:0% +So when she defended her thesis, she was + + + align:start position:0% +So when she defended her thesis, she was +forced to put this phrase in her thesis. + + align:start position:0% +forced to put this phrase in her thesis. + + + align:start position:0% +forced to put this phrase in her thesis. +The enormous abundance of hydrogen is + + align:start position:0% +The enormous abundance of hydrogen is + + + align:start position:0% +The enormous abundance of hydrogen is +almost certainly not + + align:start position:0% +almost certainly not + + + align:start position:0% +almost certainly not +real. Yeah. This is this is the way this + + align:start position:0% +real. Yeah. This is this is the way this + + + align:start position:0% +real. Yeah. This is this is the way this +is the way science welcomes newcomers. + + align:start position:0% +is the way science welcomes newcomers. + + + align:start position:0% +is the way science welcomes newcomers. +This is the way science on some + + align:start position:0% +This is the way science on some + + + align:start position:0% +This is the way science on some +occasions welcomes new + + align:start position:0% + + + + align:start position:0% + +findings just up the + + align:start position:0% +findings just up the + + + align:start position:0% +findings just up the +street. And I'm not talking about, you + + align:start position:0% +street. And I'm not talking about, you + + + align:start position:0% +street. And I'm not talking about, you +know, the 1600s. This was in the in the + + align:start position:0% +know, the 1600s. This was in the in the + + + align:start position:0% +know, the 1600s. This was in the in the +30s. So, this is a painting of her. + + align:start position:0% +30s. So, this is a painting of her. + + + align:start position:0% +30s. So, this is a painting of her. +Dudley Hersbach, who's a Harvard uh + + align:start position:0% +Dudley Hersbach, who's a Harvard uh + + + align:start position:0% +Dudley Hersbach, who's a Harvard uh +chemistry professor who has a Nobel + + align:start position:0% +chemistry professor who has a Nobel + + + align:start position:0% +chemistry professor who has a Nobel +Prize, uh had this painting hung at one + + align:start position:0% +Prize, uh had this painting hung at one + + + align:start position:0% +Prize, uh had this painting hung at one +of the halls, and it's a it's obviously + + align:start position:0% +of the halls, and it's a it's obviously + + + align:start position:0% +of the halls, and it's a it's obviously +referential to Vermeier's the + + align:start position:0% +referential to Vermeier's the + + + align:start position:0% +referential to Vermeier's the +astronomer. + + align:start position:0% +astronomer. + + + align:start position:0% +astronomer. +So, + + align:start position:0% +So, + + + align:start position:0% +So, +um, we've come a long way from the gas + + align:start position:0% +um, we've come a long way from the gas + + + align:start position:0% +um, we've come a long way from the gas +discharge tube to the heavens, but it + + align:start position:0% +discharge tube to the heavens, but it + + + align:start position:0% +discharge tube to the heavens, but it +shows you that with a little bit of + + align:start position:0% +shows you that with a little bit of + + + align:start position:0% +shows you that with a little bit of +understanding of quantization, you can + + align:start position:0% +understanding of quantization, you can + + + align:start position:0% +understanding of quantization, you can +go a long way. Okay, we'll see you + + align:start position:0% +go a long way. Okay, we'll see you + + + align:start position:0% +go a long way. Okay, we'll see you +Friday. \ No newline at end of file diff --git a/r4-cftqTcdI.txt b/r4-cftqTcdI.txt new file mode 100644 index 0000000000000000000000000000000000000000..0facea0eb6dd161b6e95332d311672f2368337c4 --- /dev/null +++ b/r4-cftqTcdI.txt @@ -0,0 +1,12011 @@ +align:start position:0% + +all right welcome back to double-oh-six + + align:start position:0% +all right welcome back to double-oh-six + + + align:start position:0% +all right welcome back to double-oh-six +today we start a totally new section of + + align:start position:0% +today we start a totally new section of + + + align:start position:0% +today we start a totally new section of +the class + + align:start position:0% +the class + + + align:start position:0% +the class +up till now we've mostly been showing + + align:start position:0% +up till now we've mostly been showing + + + align:start position:0% +up till now we've mostly been showing +you really cool and powerful + + align:start position:0% +you really cool and powerful + + + align:start position:0% +you really cool and powerful +algorithms sorting algorithms graph + + align:start position:0% +algorithms sorting algorithms graph + + + align:start position:0% +algorithms sorting algorithms graph +algorithms data structures trees + + align:start position:0% +algorithms data structures trees + + + align:start position:0% +algorithms data structures trees +lots of good stuff that you can apply to + + align:start position:0% +lots of good stuff that you can apply to + + + align:start position:0% +lots of good stuff that you can apply to +solve tons of algorithmic problems + + align:start position:0% +solve tons of algorithmic problems + + + align:start position:0% +solve tons of algorithmic problems +either by reducing to the + + align:start position:0% +either by reducing to the + + + align:start position:0% +either by reducing to the +things data structures that we we showed + + align:start position:0% +things data structures that we we showed + + + align:start position:0% +things data structures that we we showed +you or reducing to the graph problems + + align:start position:0% +you or reducing to the graph problems + + + align:start position:0% +you or reducing to the graph problems +that we showed you + + align:start position:0% +that we showed you + + + align:start position:0% +that we showed you +or by modifying those algorithms a bit + + align:start position:0% +or by modifying those algorithms a bit + + + align:start position:0% +or by modifying those algorithms a bit +today we're going to start a + + align:start position:0% +today we're going to start a + + + align:start position:0% +today we're going to start a +new section on algorithmic design how to + + align:start position:0% +new section on algorithmic design how to + + + align:start position:0% +new section on algorithmic design how to +from scratch come up with a polynomial + + align:start position:0% +from scratch come up with a polynomial + + + align:start position:0% +from scratch come up with a polynomial +time algorithm to solve a problem + + align:start position:0% +time algorithm to solve a problem + + + align:start position:0% +time algorithm to solve a problem +so this is a and in particular we're + + align:start position:0% +so this is a and in particular we're + + + align:start position:0% +so this is a and in particular we're +going to talk about + + align:start position:0% +going to talk about + + + align:start position:0% +going to talk about +a algorithmic design paradigm called + + align:start position:0% +a algorithmic design paradigm called + + + align:start position:0% +a algorithmic design paradigm called +dynamic programming + + align:start position:0% +dynamic programming + + + align:start position:0% +dynamic programming +which is extremely powerful it's + + align:start position:0% +which is extremely powerful it's + + + align:start position:0% +which is extremely powerful it's +probably the most powerful algorithmic + + align:start position:0% +probably the most powerful algorithmic + + + align:start position:0% +probably the most powerful algorithmic +design paradigm very general + + align:start position:0% +design paradigm very general + + + align:start position:0% +design paradigm very general +can solve lots of problems it's a + + align:start position:0% +can solve lots of problems it's a + + + align:start position:0% +can solve lots of problems it's a +particular type of recursive algorithm + + align:start position:0% +particular type of recursive algorithm + + + align:start position:0% +particular type of recursive algorithm +design + + align:start position:0% +design + + + align:start position:0% +design +and in general this class + + align:start position:0% +and in general this class + + + align:start position:0% +and in general this class +all of algorithms is about recursive + + align:start position:0% +all of algorithms is about recursive + + + align:start position:0% +all of algorithms is about recursive +algorithm design + + align:start position:0% +algorithm design + + + align:start position:0% +algorithm design +at some level because we want to write + + align:start position:0% +at some level because we want to write + + + align:start position:0% +at some level because we want to write +constant size pieces of code + + align:start position:0% +constant size pieces of code + + + align:start position:0% +constant size pieces of code +that solve problems of arbitrary size we + + align:start position:0% +that solve problems of arbitrary size we + + + align:start position:0% +that solve problems of arbitrary size we +have some problem size + + align:start position:0% +have some problem size + + + align:start position:0% +have some problem size +n and we're trying to write you know 100 + + align:start position:0% +n and we're trying to write you know 100 + + + align:start position:0% +n and we're trying to write you know 100 +lines of code or whatever some constant + + align:start position:0% +lines of code or whatever some constant + + + align:start position:0% +lines of code or whatever some constant +amount that doesn't depend on the + + align:start position:0% +amount that doesn't depend on the + + + align:start position:0% +amount that doesn't depend on the +problem size we have one algorithm that + + align:start position:0% +problem size we have one algorithm that + + + align:start position:0% +problem size we have one algorithm that +solves all + + align:start position:0% +solves all + + + align:start position:0% +solves all +instances of the problem and so we have + + align:start position:0% +instances of the problem and so we have + + + align:start position:0% +instances of the problem and so we have +to write code + + align:start position:0% +to write code + + + align:start position:0% +to write code +that is recursive or uses loops or + + align:start position:0% +that is recursive or uses loops or + + + align:start position:0% +that is recursive or uses loops or +somehow reuses the instructions that we + + align:start position:0% +somehow reuses the instructions that we + + + align:start position:0% +somehow reuses the instructions that we +give the computer + + align:start position:0% +give the computer + + + align:start position:0% +give the computer +and you may know you can convert any + + align:start position:0% +and you may know you can convert any + + + align:start position:0% +and you may know you can convert any +algorithm based on loops into an + + align:start position:0% +algorithm based on loops into an + + + align:start position:0% +algorithm based on loops into an +algorithm + + align:start position:0% +algorithm + + + align:start position:0% +algorithm +using recursion and we're going to take + + align:start position:0% +using recursion and we're going to take + + + align:start position:0% +using recursion and we're going to take +the recursive view today + + align:start position:0% +the recursive view today + + + align:start position:0% +the recursive view today +in particular because it fits very well + + align:start position:0% +in particular because it fits very well + + + align:start position:0% +in particular because it fits very well +with our proof by induction + + align:start position:0% +with our proof by induction + + + align:start position:0% +with our proof by induction +technique which we've used throughout + + align:start position:0% +technique which we've used throughout + + + align:start position:0% +technique which we've used throughout +this class + + align:start position:0% +this class + + + align:start position:0% +this class +but also because it gives us some + + align:start position:0% +but also because it gives us some + + + align:start position:0% +but also because it gives us some +structure on how + + align:start position:0% +structure on how + + + align:start position:0% +structure on how +different subproblems relate in + + align:start position:0% +different subproblems relate in + + + align:start position:0% +different subproblems relate in +something called a sub problem graph + + align:start position:0% +something called a sub problem graph + + + align:start position:0% +something called a sub problem graph +that we'll be talking about today + + align:start position:0% +that we'll be talking about today + + + align:start position:0% +that we'll be talking about today +and so we're going to start out with in + + align:start position:0% +and so we're going to start out with in + + + align:start position:0% +and so we're going to start out with in +general how do we design recursive + + align:start position:0% +general how do we design recursive + + + align:start position:0% +general how do we design recursive +algorithms + + align:start position:0% +algorithms + + + align:start position:0% +algorithms +that's sort of the overall encompassing + + align:start position:0% +that's sort of the overall encompassing + + + align:start position:0% +that's sort of the overall encompassing +everything we have + + align:start position:0% +everything we have + + + align:start position:0% +everything we have +thought very hard to come up with a cool + + align:start position:0% +thought very hard to come up with a cool + + + align:start position:0% +thought very hard to come up with a cool +acronym for this paradigm + + align:start position:0% +acronym for this paradigm + + + align:start position:0% +acronym for this paradigm +which we invented called sort bot thanks + + align:start position:0% +which we invented called sort bot thanks + + + align:start position:0% +which we invented called sort bot thanks +jason + + align:start position:0% +jason + + + align:start position:0% +jason +and so we'll talk it's not actually for + + align:start position:0% +and so we'll talk it's not actually for + + + align:start position:0% +and so we'll talk it's not actually for +sorting it's just an acronym for + + align:start position:0% +sorting it's just an acronym for + + + align:start position:0% +sorting it's just an acronym for +subproblems + + align:start position:0% + + + + align:start position:0% + +relations topological order base case + + align:start position:0% +relations topological order base case + + + align:start position:0% +relations topological order base case +original problem and time but it's an + + align:start position:0% +original problem and time but it's an + + + align:start position:0% +original problem and time but it's an +acronym that + + align:start position:0% +acronym that + + + align:start position:0% +acronym that +will help you remember all the steps you + + align:start position:0% +will help you remember all the steps you + + + align:start position:0% +will help you remember all the steps you +need in order to specify a recursive + + align:start position:0% +need in order to specify a recursive + + + align:start position:0% +need in order to specify a recursive +algorithm + + align:start position:0% +algorithm + + + align:start position:0% +algorithm +and dynamic programming is going to + + align:start position:0% +and dynamic programming is going to + + + align:start position:0% +and dynamic programming is going to +build on this template + + align:start position:0% +build on this template + + + align:start position:0% +build on this template +by adding one new idea called + + align:start position:0% +by adding one new idea called + + + align:start position:0% +by adding one new idea called +memoization which is just the idea of + + align:start position:0% +memoization which is just the idea of + + + align:start position:0% +memoization which is just the idea of +reusing work that you've done before + + align:start position:0% +reusing work that you've done before + + + align:start position:0% +reusing work that you've done before +and that's going to let us solve tons of + + align:start position:0% +and that's going to let us solve tons of + + + align:start position:0% +and that's going to let us solve tons of +problems + + align:start position:0% +problems + + + align:start position:0% +problems +and let's see i don't uh + + align:start position:0% +and let's see i don't uh + + + align:start position:0% +and let's see i don't uh +let's get into it so we'll start out + + align:start position:0% +let's get into it so we'll start out + + + align:start position:0% +let's get into it so we'll start out +today with sort bots so here is sort + + align:start position:0% +today with sort bots so here is sort + + + align:start position:0% +today with sort bots so here is sort +bot down the column here this is a + + align:start position:0% +bot down the column here this is a + + + align:start position:0% +bot down the column here this is a +recursive algorithm design paradigm + + align:start position:0% +recursive algorithm design paradigm + + + align:start position:0% +recursive algorithm design paradigm +and in general what we're going to do is + + align:start position:0% +and in general what we're going to do is + + + align:start position:0% +and in general what we're going to do is +take the problem that we actually want + + align:start position:0% +take the problem that we actually want + + + align:start position:0% +take the problem that we actually want +to solve + + align:start position:0% +to solve + + + align:start position:0% +to solve +and split it up into lots of possible + + align:start position:0% +and split it up into lots of possible + + + align:start position:0% +and split it up into lots of possible +sub problems + + align:start position:0% +sub problems + + + align:start position:0% +sub problems +and so the first part is to define what + + align:start position:0% +and so the first part is to define what + + + align:start position:0% +and so the first part is to define what +the heck are the sub problems in general + + align:start position:0% +the heck are the sub problems in general + + + align:start position:0% +the heck are the sub problems in general +we'll want some polynomial number of + + align:start position:0% +we'll want some polynomial number of + + + align:start position:0% +we'll want some polynomial number of +them + + align:start position:0% +them + + + align:start position:0% +them +but it's pretty open-ended what these + + align:start position:0% +but it's pretty open-ended what these + + + align:start position:0% +but it's pretty open-ended what these +look like + + align:start position:0% +look like + + + align:start position:0% +look like +and the hardest part usually in + + align:start position:0% +and the hardest part usually in + + + align:start position:0% +and the hardest part usually in +deceptive defining a recursive algorithm + + align:start position:0% +deceptive defining a recursive algorithm + + + align:start position:0% +deceptive defining a recursive algorithm +is figuring out what the sub problems + + align:start position:0% +is figuring out what the sub problems + + + align:start position:0% +is figuring out what the sub problems +should be + + align:start position:0% +should be + + + align:start position:0% +should be +usually they're related to the problem + + align:start position:0% +usually they're related to the problem + + + align:start position:0% +usually they're related to the problem +you want to solve often + + align:start position:0% +you want to solve often + + + align:start position:0% +you want to solve often +the problem you want to solve this is + + align:start position:0% +the problem you want to solve this is + + + align:start position:0% +the problem you want to solve this is +actually near the last step + + align:start position:0% +actually near the last step + + + align:start position:0% +actually near the last step +the original problem you're trying to + + align:start position:0% +the original problem you're trying to + + + align:start position:0% +the original problem you're trying to +solve is often one of these sub problems + + align:start position:0% +solve is often one of these sub problems + + + align:start position:0% +solve is often one of these sub problems +and then you use the smaller sub + + align:start position:0% +and then you use the smaller sub + + + align:start position:0% +and then you use the smaller sub +problems in order to build up + + align:start position:0% +problems in order to build up + + + align:start position:0% +problems in order to build up +the final original problem but sometimes + + align:start position:0% +the final original problem but sometimes + + + align:start position:0% +the final original problem but sometimes +at the end you need to + + align:start position:0% +at the end you need to + + + align:start position:0% +at the end you need to +take a bunch of sub problems and combine + + align:start position:0% +take a bunch of sub problems and combine + + + align:start position:0% +take a bunch of sub problems and combine +it into your original problem + + align:start position:0% +it into your original problem + + + align:start position:0% +it into your original problem +you can think one analogy you can think + + align:start position:0% +you can think one analogy you can think + + + align:start position:0% +you can think one analogy you can think +of here is divide and conquer algorithms + + align:start position:0% +of here is divide and conquer algorithms + + + align:start position:0% +of here is divide and conquer algorithms +which also had this kind of style but + + align:start position:0% +which also had this kind of style but + + + align:start position:0% +which also had this kind of style but +more generally we're going to relate + + align:start position:0% +more generally we're going to relate + + + align:start position:0% +more generally we're going to relate +different subproblem solutions with some + + align:start position:0% +different subproblem solutions with some + + + align:start position:0% +different subproblem solutions with some +recursive structure some recursive + + align:start position:0% +recursive structure some recursive + + + align:start position:0% +recursive structure some recursive +recurrence relation + + align:start position:0% +recurrence relation + + + align:start position:0% +recurrence relation +this is just a recursive algorithm that + + align:start position:0% +this is just a recursive algorithm that + + + align:start position:0% +this is just a recursive algorithm that +defines how to solve one problem in + + align:start position:0% +defines how to solve one problem in + + + align:start position:0% +defines how to solve one problem in +terms of smaller + + align:start position:0% +terms of smaller + + + align:start position:0% +terms of smaller +sub-problems for some notion of smaller + + align:start position:0% +sub-problems for some notion of smaller + + + align:start position:0% +sub-problems for some notion of smaller +and this is given by the topological + + align:start position:0% +and this is given by the topological + + + align:start position:0% +and this is given by the topological +order + + align:start position:0% +order + + + align:start position:0% +order +so if we think of the sub problems as a + + align:start position:0% +so if we think of the sub problems as a + + + align:start position:0% +so if we think of the sub problems as a +graph + + align:start position:0% +graph + + + align:start position:0% +graph +and we draw an edge between + + align:start position:0% +and we draw an edge between + + + align:start position:0% +and we draw an edge between +so the vertices of the graph are sub + + align:start position:0% +so the vertices of the graph are sub + + + align:start position:0% +so the vertices of the graph are sub +problems the edges are the dependencies + + align:start position:0% +problems the edges are the dependencies + + + align:start position:0% +problems the edges are the dependencies +between those sub problems then what + + align:start position:0% +between those sub problems then what + + + align:start position:0% +between those sub problems then what +we'd like + + align:start position:0% +we'd like + + + align:start position:0% +we'd like +is the topological ordering the + + align:start position:0% +is the topological ordering the + + + align:start position:0% +is the topological ordering the +topological sort problem we talked about + + align:start position:0% +topological sort problem we talked about + + + align:start position:0% +topological sort problem we talked about +in the context of dfs or dag shortest + + align:start position:0% +in the context of dfs or dag shortest + + + align:start position:0% +in the context of dfs or dag shortest +paths + + align:start position:0% +paths + + + align:start position:0% +paths +uh what we would like is that this uh + + align:start position:0% +uh what we would like is that this uh + + + align:start position:0% +uh what we would like is that this uh +the sub problems and the calls the + + align:start position:0% +the sub problems and the calls the + + + align:start position:0% +the sub problems and the calls the +recursive calls between them in this + + align:start position:0% +recursive calls between them in this + + + align:start position:0% +recursive calls between them in this +recursive relation + + align:start position:0% +recursive relation + + + align:start position:0% +recursive relation +forms a dag we want it to be acyclic + + align:start position:0% +forms a dag we want it to be acyclic + + + align:start position:0% +forms a dag we want it to be acyclic +otherwise + + align:start position:0% +otherwise + + + align:start position:0% +otherwise +you have an infinite loop in your + + align:start position:0% +you have an infinite loop in your + + + align:start position:0% +you have an infinite loop in your +recursive calls if you have a cycle + + align:start position:0% +recursive calls if you have a cycle + + + align:start position:0% +recursive calls if you have a cycle +you're just go you'll never terminate + + align:start position:0% +you're just go you'll never terminate + + + align:start position:0% +you're just go you'll never terminate +and so to spec to make sure that our + + align:start position:0% +and so to spec to make sure that our + + + align:start position:0% +and so to spec to make sure that our +these dependencies between subproblems + + align:start position:0% +these dependencies between subproblems + + + align:start position:0% +these dependencies between subproblems +given by this recurrence relation + + align:start position:0% +given by this recurrence relation + + + align:start position:0% +given by this recurrence relation +is a cyclic uh one way to do that is to + + align:start position:0% +is a cyclic uh one way to do that is to + + + align:start position:0% +is a cyclic uh one way to do that is to +specify a topological order + + align:start position:0% +specify a topological order + + + align:start position:0% +specify a topological order +okay or you could prove it some other + + align:start position:0% +okay or you could prove it some other + + + align:start position:0% +okay or you could prove it some other +way but often it's just a for loop + + align:start position:0% +way but often it's just a for loop + + + align:start position:0% +way but often it's just a for loop +to say just do it in this order then of + + align:start position:0% +to say just do it in this order then of + + + align:start position:0% +to say just do it in this order then of +course + + align:start position:0% +course + + + align:start position:0% +course +any recursive structure needs base cases + + align:start position:0% +any recursive structure needs base cases + + + align:start position:0% +any recursive structure needs base cases +so + + align:start position:0% +so + + + align:start position:0% +so +that's a useful step not to forget um we + + align:start position:0% +that's a useful step not to forget um we + + + align:start position:0% +that's a useful step not to forget um we +want to solve the original problem using + + align:start position:0% +want to solve the original problem using + + + align:start position:0% +want to solve the original problem using +these sub problems and then we analyze + + align:start position:0% +these sub problems and then we analyze + + + align:start position:0% +these sub problems and then we analyze +our running time + + align:start position:0% +our running time + + + align:start position:0% +our running time +at the end so six easy steps + + align:start position:0% +at the end so six easy steps + + + align:start position:0% +at the end so six easy steps +actually the hardest ones are these two + + align:start position:0% +actually the hardest ones are these two + + + align:start position:0% +actually the hardest ones are these two +which are interrelated + + align:start position:0% +which are interrelated + + + align:start position:0% +which are interrelated +and what we're going to see over the + + align:start position:0% +and what we're going to see over the + + + align:start position:0% +and what we're going to see over the +next four lectures this is the first of + + align:start position:0% +next four lectures this is the first of + + + align:start position:0% +next four lectures this is the first of +four lectures on dynamic programming + + align:start position:0% +four lectures on dynamic programming + + + align:start position:0% +four lectures on dynamic programming +is lots of examples of applying this + + align:start position:0% +is lots of examples of applying this + + + align:start position:0% +is lots of examples of applying this +paradigm over and over + + align:start position:0% +paradigm over and over + + + align:start position:0% +paradigm over and over +together with the memoization idea which + + align:start position:0% +together with the memoization idea which + + + align:start position:0% +together with the memoization idea which +we'll get to soon + + align:start position:0% +we'll get to soon + + + align:start position:0% +we'll get to soon +let's see an example first of an + + align:start position:0% +let's see an example first of an + + + align:start position:0% +let's see an example first of an +algorithm we've already seen which is + + align:start position:0% +algorithm we've already seen which is + + + align:start position:0% +algorithm we've already seen which is +merge sort + + align:start position:0% +merge sort + + + align:start position:0% +merge sort +so a divide and conquer algorithm + + align:start position:0% +so a divide and conquer algorithm + + + align:start position:0% +so a divide and conquer algorithm +phrased in this + + align:start position:0% +phrased in this + + + align:start position:0% +phrased in this +with this structure of sort bot so for + + align:start position:0% +with this structure of sort bot so for + + + align:start position:0% +with this structure of sort bot so for +the subproblems + + align:start position:0% +the subproblems + + + align:start position:0% +the subproblems +so original problem is to sort the + + align:start position:0% +so original problem is to sort the + + + align:start position:0% +so original problem is to sort the +elements of a + + align:start position:0% +elements of a + + + align:start position:0% +elements of a +and some sub problems that we solve + + align:start position:0% +and some sub problems that we solve + + + align:start position:0% +and some sub problems that we solve +along the way are sorting different + + align:start position:0% +along the way are sorting different + + + align:start position:0% +along the way are sorting different +subarrays of a so for every well not for + + align:start position:0% +subarrays of a so for every well not for + + + align:start position:0% +subarrays of a so for every well not for +every i and j but for some + + align:start position:0% +every i and j but for some + + + align:start position:0% +every i and j but for some +i and js we sort the items from + + align:start position:0% +i and js we sort the items from + + + align:start position:0% +i and js we sort the items from +i up to j minus 1. so i'm going to + + align:start position:0% +i up to j minus 1. so i'm going to + + + align:start position:0% +i up to j minus 1. so i'm going to +define that subproblem to be + + align:start position:0% +define that subproblem to be + + + align:start position:0% +define that subproblem to be +s of i j so this is something that i + + align:start position:0% +s of i j so this is something that i + + + align:start position:0% +s of i j so this is something that i +might want to solve + + align:start position:0% +might want to solve + + + align:start position:0% +might want to solve +the original problem that i want to + + align:start position:0% +the original problem that i want to + + + align:start position:0% +the original problem that i want to +solve is s of 0 comma n where n is the + + align:start position:0% +solve is s of 0 comma n where n is the + + + align:start position:0% +solve is s of 0 comma n where n is the +length of the array + + align:start position:0% +length of the array + + + align:start position:0% +length of the array +so that's what i actually care about in + + align:start position:0% +so that's what i actually care about in + + + align:start position:0% +so that's what i actually care about in +the end but we're going to solve that + + align:start position:0% +the end but we're going to solve that + + + align:start position:0% +the end but we're going to solve that +by writing it recursively in terms of + + align:start position:0% +by writing it recursively in terms of + + + align:start position:0% +by writing it recursively in terms of +sorting different + + align:start position:0% +sorting different + + + align:start position:0% +sorting different +subarrays as follows this is the + + align:start position:0% +subarrays as follows this is the + + + align:start position:0% +subarrays as follows this is the +recurrence relation + + align:start position:0% +recurrence relation + + + align:start position:0% +recurrence relation +i've written it very simply here of + + align:start position:0% +i've written it very simply here of + + + align:start position:0% +i've written it very simply here of +course there's a merge algorithm + + align:start position:0% +course there's a merge algorithm + + + align:start position:0% +course there's a merge algorithm +which is uh somewhat complicated but + + align:start position:0% +which is uh somewhat complicated but + + + align:start position:0% +which is uh somewhat complicated but +it's we we saw the two finger + + align:start position:0% +it's we we saw the two finger + + + align:start position:0% +it's we we saw the two finger +linear time merge algorithm given two + + align:start position:0% +linear time merge algorithm given two + + + align:start position:0% +linear time merge algorithm given two +sorted arrays so this is supposed to be + + align:start position:0% +sorted arrays so this is supposed to be + + + align:start position:0% +sorted arrays so this is supposed to be +the sorted array version of the items i + + align:start position:0% +the sorted array version of the items i + + + align:start position:0% +the sorted array version of the items i +through m + + align:start position:0% +through m + + + align:start position:0% +through m +m is the middle element between i and j + + align:start position:0% +m is the middle element between i and j + + + align:start position:0% +m is the middle element between i and j +and + + align:start position:0% +and + + + align:start position:0% +and +the sorted array of the items from m up + + align:start position:0% +the sorted array of the items from m up + + + align:start position:0% +the sorted array of the items from m up +to j + + align:start position:0% +to j + + + align:start position:0% +to j +if we merge those that gives us the + + align:start position:0% +if we merge those that gives us the + + + align:start position:0% +if we merge those that gives us the +sorted array + + align:start position:0% +sorted array + + + align:start position:0% +sorted array +from i up to j and that's exactly what + + align:start position:0% +from i up to j and that's exactly what + + + align:start position:0% +from i up to j and that's exactly what +merge sort + + align:start position:0% +merge sort + + + align:start position:0% +merge sort +does so this is in general this relation + + align:start position:0% +does so this is in general this relation + + + align:start position:0% +does so this is in general this relation +is just some algorithm + + align:start position:0% +is just some algorithm + + + align:start position:0% +is just some algorithm +for if you if you're given the solutions + + align:start position:0% +for if you if you're given the solutions + + + align:start position:0% +for if you if you're given the solutions +to some smaller sub problems + + align:start position:0% +to some smaller sub problems + + + align:start position:0% +to some smaller sub problems +how do i solve uh the sub problem that i + + align:start position:0% +how do i solve uh the sub problem that i + + + align:start position:0% +how do i solve uh the sub problem that i +want to solve + + align:start position:0% + + + + align:start position:0% + +and so we need to make sure that this + + align:start position:0% +and so we need to make sure that this + + + align:start position:0% +and so we need to make sure that this +problem + + align:start position:0% +problem + + + align:start position:0% +problem +is bigger than the ones that we + + align:start position:0% +is bigger than the ones that we + + + align:start position:0% +is bigger than the ones that we +recursively call on + + align:start position:0% +recursively call on + + + align:start position:0% +recursively call on +and that we don't get an infinite cyclic + + align:start position:0% +and that we don't get an infinite cyclic + + + align:start position:0% +and that we don't get an infinite cyclic +group of recursions + + align:start position:0% +group of recursions + + + align:start position:0% +group of recursions +and here a valid topological order is to + + align:start position:0% +and here a valid topological order is to + + + align:start position:0% +and here a valid topological order is to +say solve these problems in order + + align:start position:0% +say solve these problems in order + + + align:start position:0% +say solve these problems in order +where j minus i the length of the + + align:start position:0% +where j minus i the length of the + + + align:start position:0% +where j minus i the length of the +subarray + + align:start position:0% +subarray + + + align:start position:0% +subarray +is increasing and then you can check + + align:start position:0% +is increasing and then you can check + + + align:start position:0% +is increasing and then you can check +because m + + align:start position:0% +because m + + + align:start position:0% +because m +is strictly between i and j as long as + + align:start position:0% +is strictly between i and j as long as + + + align:start position:0% +is strictly between i and j as long as +we're not in a base case + + align:start position:0% +we're not in a base case + + + align:start position:0% +we're not in a base case +then we know uh we can + + align:start position:0% +then we know uh we can + + + align:start position:0% +then we know uh we can +these subarrays will be smaller than + + align:start position:0% +these subarrays will be smaller than + + + align:start position:0% +these subarrays will be smaller than +this one and so this increasing order + + align:start position:0% +this one and so this increasing order + + + align:start position:0% +this one and so this increasing order +gives us a valid topological order + + align:start position:0% +gives us a valid topological order + + + align:start position:0% +gives us a valid topological order +on all of the problems all the sub + + align:start position:0% +on all of the problems all the sub + + + align:start position:0% +on all of the problems all the sub +problems uh we have a base case which is + + align:start position:0% +problems uh we have a base case which is + + + align:start position:0% +problems uh we have a base case which is +if we don't want to sort anything + + align:start position:0% +if we don't want to sort anything + + + align:start position:0% +if we don't want to sort anything +that's the empty array i already said + + align:start position:0% +that's the empty array i already said + + + align:start position:0% +that's the empty array i already said +the original problem and then running + + align:start position:0% +the original problem and then running + + + align:start position:0% +the original problem and then running +time + + align:start position:0% +time + + + align:start position:0% +time +is i mean there's no better way to solve + + align:start position:0% +is i mean there's no better way to solve + + + align:start position:0% +is i mean there's no better way to solve +it than + + align:start position:0% +it than + + + align:start position:0% +it than +the recurrence that we already saw how + + align:start position:0% +the recurrence that we already saw how + + + align:start position:0% +the recurrence that we already saw how +to solve so this is just another way to + + align:start position:0% +to solve so this is just another way to + + + align:start position:0% +to solve so this is just another way to +think of n log n merge sort + + align:start position:0% +think of n log n merge sort + + + align:start position:0% +think of n log n merge sort +in this labeled framework of sort bot + + align:start position:0% +in this labeled framework of sort bot + + + align:start position:0% +in this labeled framework of sort bot +let's get to another problem that does + + align:start position:0% +let's get to another problem that does + + + align:start position:0% +let's get to another problem that does +not + + align:start position:0% +not + + + align:start position:0% +not +fit recursion so well but we can + + align:start position:0% +fit recursion so well but we can + + + align:start position:0% +fit recursion so well but we can +make it better so this we're going to + + align:start position:0% +make it better so this we're going to + + + align:start position:0% +make it better so this we're going to +start with a very simple problem which + + align:start position:0% +start with a very simple problem which + + + align:start position:0% +start with a very simple problem which +is + + align:start position:0% +is + + + align:start position:0% +is +computing fibonacci numbers + + align:start position:0% + + + + align:start position:0% + +it's really just a toy problem to + + align:start position:0% +it's really just a toy problem to + + + align:start position:0% +it's really just a toy problem to +illustrate a very powerful idea which is + + align:start position:0% +illustrate a very powerful idea which is + + + align:start position:0% +illustrate a very powerful idea which is +memoization + + align:start position:0% +memoization + + + align:start position:0% +memoization +so the problem i'm interested in is i'm + + align:start position:0% +so the problem i'm interested in is i'm + + + align:start position:0% +so the problem i'm interested in is i'm +given a particular number + + align:start position:0% +given a particular number + + + align:start position:0% +given a particular number +n and i want to compute + + align:start position:0% +n and i want to compute + + + align:start position:0% +n and i want to compute +the nth fibonacci number and in case you + + align:start position:0% +the nth fibonacci number and in case you + + + align:start position:0% +the nth fibonacci number and in case you +forgot + + align:start position:0% +forgot + + + align:start position:0% +forgot +the nth fibonacci number is given by + + align:start position:0% +the nth fibonacci number is given by + + + align:start position:0% +the nth fibonacci number is given by +this recurrence fn + + align:start position:0% +this recurrence fn + + + align:start position:0% +this recurrence fn +is fn minus one plus fn minus two with + + align:start position:0% +is fn minus one plus fn minus two with + + + align:start position:0% +is fn minus one plus fn minus two with +base case + + align:start position:0% +base case + + + align:start position:0% +base case +uh let's say f1 equals f2 equals one + + align:start position:0% + + + + align:start position:0% + +and so we'd like to compute this this + + align:start position:0% +and so we'd like to compute this this + + + align:start position:0% +and so we'd like to compute this this +seems this is a recurrence + + align:start position:0% +seems this is a recurrence + + + align:start position:0% +seems this is a recurrence +so it seems very natural to write it as + + align:start position:0% +so it seems very natural to write it as + + + align:start position:0% +so it seems very natural to write it as +a recursive algorithm so let's try to do + + align:start position:0% +a recursive algorithm so let's try to do + + + align:start position:0% +a recursive algorithm so let's try to do +it + + align:start position:0% +it + + + align:start position:0% +it +we start with what are the sub-problems + + align:start position:0% +we start with what are the sub-problems + + + align:start position:0% +we start with what are the sub-problems +the obvious sub-problems + + align:start position:0% +the obvious sub-problems + + + align:start position:0% +the obvious sub-problems +are just the various fibonacci numbers + + align:start position:0% +are just the various fibonacci numbers + + + align:start position:0% +are just the various fibonacci numbers +fi for i between + + align:start position:0% +fi for i between + + + align:start position:0% +fi for i between +one and n + + align:start position:0% +one and n + + + align:start position:0% +one and n +so they're n of these sub problems + + align:start position:0% + + + + align:start position:0% + +cool let's see we want a relation + + align:start position:0% +cool let's see we want a relation + + + align:start position:0% +cool let's see we want a relation +between them + + align:start position:0% + + + + align:start position:0% + +well maybe i'll just to distinguish the + + align:start position:0% +well maybe i'll just to distinguish the + + + align:start position:0% +well maybe i'll just to distinguish the +problems from the fibonacci numbers + + align:start position:0% +problems from the fibonacci numbers + + + align:start position:0% +problems from the fibonacci numbers +let me write f of i this is a function + + align:start position:0% +let me write f of i this is a function + + + align:start position:0% +let me write f of i this is a function +an algorithm we're going to define and + + align:start position:0% +an algorithm we're going to define and + + + align:start position:0% +an algorithm we're going to define and +it's defined to be + + align:start position:0% +it's defined to be + + + align:start position:0% +it's defined to be +the goal we're trying to get is the i + + align:start position:0% +the goal we're trying to get is the i + + + align:start position:0% +the goal we're trying to get is the i +fibonacci number + + align:start position:0% +fibonacci number + + + align:start position:0% +fibonacci number +given i and then we can write + + align:start position:0% +given i and then we can write + + + align:start position:0% +given i and then we can write +the recurrence relation on these guys + + align:start position:0% +the recurrence relation on these guys + + + align:start position:0% +the recurrence relation on these guys +just uh + + align:start position:0% +just uh + + + align:start position:0% +just uh +f of i equals f of i minus 1 + + align:start position:0% +f of i equals f of i minus 1 + + + align:start position:0% +f of i equals f of i minus 1 +plus f of i minus 2. so in other words + + align:start position:0% +plus f of i minus 2. so in other words + + + align:start position:0% +plus f of i minus 2. so in other words +recursively compute + + align:start position:0% +recursively compute + + + align:start position:0% +recursively compute +those fibonacci numbers then add them + + align:start position:0% +those fibonacci numbers then add them + + + align:start position:0% +those fibonacci numbers then add them +together that's an algorithm + + align:start position:0% +together that's an algorithm + + + align:start position:0% +together that's an algorithm +next is t for topological order + + align:start position:0% + + + + align:start position:0% + +here of course we just want to compute + + align:start position:0% +here of course we just want to compute + + + align:start position:0% +here of course we just want to compute +these in order of increasing + + align:start position:0% +these in order of increasing + + + align:start position:0% +these in order of increasing +i from the base cases up + + align:start position:0% +i from the base cases up + + + align:start position:0% +i from the base cases up +another way i like to write this is as a + + align:start position:0% +another way i like to write this is as a + + + align:start position:0% +another way i like to write this is as a +for loop + + align:start position:0% +for loop + + + align:start position:0% +for loop +for i equals one to n + + align:start position:0% +for i equals one to n + + + align:start position:0% +for i equals one to n +maybe we'll see why but this gives an + + align:start position:0% +maybe we'll see why but this gives an + + + align:start position:0% +maybe we'll see why but this gives an +explicit order + + align:start position:0% +explicit order + + + align:start position:0% +explicit order +of to compute these sub-problems + + align:start position:0% + + + + align:start position:0% + +and all right base case is just the same + + align:start position:0% + + + + align:start position:0% + +as the fibonacci numbers but i guess i + + align:start position:0% +as the fibonacci numbers but i guess i + + + align:start position:0% +as the fibonacci numbers but i guess i +should write parentheses + + align:start position:0% + + + + align:start position:0% + +the original problem we want to solve is + + align:start position:0% +the original problem we want to solve is + + + align:start position:0% +the original problem we want to solve is +f + + align:start position:0% +f + + + align:start position:0% +f +n and the time + + align:start position:0% +n and the time + + + align:start position:0% +n and the time +all right here's where things get + + align:start position:0% +all right here's where things get + + + align:start position:0% +all right here's where things get +interesting or bad + + align:start position:0% +interesting or bad + + + align:start position:0% +interesting or bad +so what is the running time of this + + align:start position:0% +so what is the running time of this + + + align:start position:0% +so what is the running time of this +recursive algorithm + + align:start position:0% +recursive algorithm + + + align:start position:0% +recursive algorithm +as i've stated it so far the running + + align:start position:0% +as i've stated it so far the running + + + align:start position:0% +as i've stated it so far the running +time is + + align:start position:0% +time is + + + align:start position:0% +time is +given by a recurrence let's write the + + align:start position:0% +given by a recurrence let's write the + + + align:start position:0% +given by a recurrence let's write the +recurrence + + align:start position:0% +recurrence + + + align:start position:0% +recurrence +so in order to compute f of n uh + + align:start position:0% +so in order to compute f of n uh + + + align:start position:0% +so in order to compute f of n uh +i recursively compute f of i minus 1 + + align:start position:0% +i recursively compute f of i minus 1 + + + align:start position:0% +i recursively compute f of i minus 1 +or f of n minus 1 here + + align:start position:0% +or f of n minus 1 here + + + align:start position:0% +or f of n minus 1 here +and i recursively compute f + + align:start position:0% +and i recursively compute f + + + align:start position:0% +and i recursively compute f +of n minus 2 so that will take t of n + + align:start position:0% +of n minus 2 so that will take t of n + + + align:start position:0% +of n minus 2 so that will take t of n +minus 2 this first step will take t of n + + align:start position:0% +minus 2 this first step will take t of n + + + align:start position:0% +minus 2 this first step will take t of n +minus 1. + + align:start position:0% +minus 1. + + + align:start position:0% +minus 1. +and now i need to solve this recurrence + + align:start position:0% +and now i need to solve this recurrence + + + align:start position:0% +and now i need to solve this recurrence +uh this is not a recurrence that falls + + align:start position:0% +uh this is not a recurrence that falls + + + align:start position:0% +uh this is not a recurrence that falls +to the master method it doesn't have a + + align:start position:0% +to the master method it doesn't have a + + + align:start position:0% +to the master method it doesn't have a +divided by so we have to think about it + + align:start position:0% +divided by so we have to think about it + + + align:start position:0% +divided by so we have to think about it +a little bit + + align:start position:0% +a little bit + + + align:start position:0% +a little bit +but we don't have to think about it too + + align:start position:0% +but we don't have to think about it too + + + align:start position:0% +but we don't have to think about it too +hard because this recurrence + + align:start position:0% +hard because this recurrence + + + align:start position:0% +hard because this recurrence +is the same as this recurrence which is + + align:start position:0% +is the same as this recurrence which is + + + align:start position:0% +is the same as this recurrence which is +the same as this recurrence i've written + + align:start position:0% +the same as this recurrence i've written + + + align:start position:0% +the same as this recurrence i've written +it three times now + + align:start position:0% +it three times now + + + align:start position:0% +it three times now +and so the solution to this is the nth + + align:start position:0% +and so the solution to this is the nth + + + align:start position:0% +and so the solution to this is the nth +fibonacci number + + align:start position:0% +fibonacci number + + + align:start position:0% +fibonacci number +uh oh sorry it's a little bit worse + + align:start position:0% +uh oh sorry it's a little bit worse + + + align:start position:0% +uh oh sorry it's a little bit worse +because + + align:start position:0% +because + + + align:start position:0% +because +in addition to those recursions i also + + align:start position:0% +in addition to those recursions i also + + + align:start position:0% +in addition to those recursions i also +spend constant time to do the addition + + align:start position:0% +spend constant time to do the addition + + + align:start position:0% +spend constant time to do the addition +maybe more than constant time but if we + + align:start position:0% +maybe more than constant time but if we + + + align:start position:0% +maybe more than constant time but if we +just count the number of additions we do + + align:start position:0% +just count the number of additions we do + + + align:start position:0% +just count the number of additions we do +it will be plus plus one + + align:start position:0% + + + + align:start position:0% + +additions + + align:start position:0% +additions + + + align:start position:0% +additions +okay but this is bigger than the nth + + align:start position:0% +okay but this is bigger than the nth + + + align:start position:0% +okay but this is bigger than the nth +fibonacci number + + align:start position:0% +fibonacci number + + + align:start position:0% +fibonacci number +and if you know anything about fibonacci + + align:start position:0% +and if you know anything about fibonacci + + + align:start position:0% +and if you know anything about fibonacci +numbers + + align:start position:0% +numbers + + + align:start position:0% +numbers +they grow exponentially they're about + + align:start position:0% +they grow exponentially they're about + + + align:start position:0% +they grow exponentially they're about +golden ratio to the n i'm wearing golden + + align:start position:0% +golden ratio to the n i'm wearing golden + + + align:start position:0% +golden ratio to the n i'm wearing golden +ratio in case you forgot the number + + align:start position:0% +ratio in case you forgot the number + + + align:start position:0% +ratio in case you forgot the number +so that's bad because golden ratio is + + align:start position:0% +so that's bad because golden ratio is + + + align:start position:0% +so that's bad because golden ratio is +bigger than one so this is exponential + + align:start position:0% +bigger than one so this is exponential + + + align:start position:0% +bigger than one so this is exponential +growth + + align:start position:0% +growth + + + align:start position:0% +growth +as we know especially in this time + + align:start position:0% +as we know especially in this time + + + align:start position:0% +as we know especially in this time +exponential growth is bad + + align:start position:0% +exponential growth is bad + + + align:start position:0% +exponential growth is bad +and algorithms exponential growth is bad + + align:start position:0% +and algorithms exponential growth is bad + + + align:start position:0% +and algorithms exponential growth is bad +because we can only solve very small + + align:start position:0% +because we can only solve very small + + + align:start position:0% +because we can only solve very small +problems with exponential growth very + + align:start position:0% +problems with exponential growth very + + + align:start position:0% +problems with exponential growth very +small n so this is a + + align:start position:0% +small n so this is a + + + align:start position:0% +small n so this is a +terrible way to compute the nth + + align:start position:0% +terrible way to compute the nth + + + align:start position:0% +terrible way to compute the nth +fibonacci number + + align:start position:0% + + + + align:start position:0% + +exponential + + align:start position:0% + + + + align:start position:0% + +bad + + align:start position:0% + + + + align:start position:0% + +okay so don't do this + + align:start position:0% +okay so don't do this + + + align:start position:0% +okay so don't do this +but there's a very tiny tweak to this + + align:start position:0% +but there's a very tiny tweak to this + + + align:start position:0% +but there's a very tiny tweak to this +algorithm + + align:start position:0% +algorithm + + + align:start position:0% +algorithm +that makes it really good which is + + align:start position:0% +that makes it really good which is + + + align:start position:0% +that makes it really good which is +memoization and this is a big idea + + align:start position:0% +memoization and this is a big idea + + + align:start position:0% +memoization and this is a big idea +it is the big idea of dynamic + + align:start position:0% + + + + align:start position:0% + +programming + + align:start position:0% +programming + + + align:start position:0% +programming +it's a funny word probably made up by a + + align:start position:0% +it's a funny word probably made up by a + + + align:start position:0% +it's a funny word probably made up by a +computer scientist + + align:start position:0% +computer scientist + + + align:start position:0% +computer scientist +um instead of memorization it's + + align:start position:0% +um instead of memorization it's + + + align:start position:0% +um instead of memorization it's +memoization + + align:start position:0% +memoization + + + align:start position:0% +memoization +because we're going to write things down + + align:start position:0% +because we're going to write things down + + + align:start position:0% +because we're going to write things down +in a memo pad is the idea + + align:start position:0% +in a memo pad is the idea + + + align:start position:0% +in a memo pad is the idea +and it's a very simple idea which is + + align:start position:0% +and it's a very simple idea which is + + + align:start position:0% +and it's a very simple idea which is +just remember + + align:start position:0% +just remember + + + align:start position:0% +just remember +and reuse solutions to sub-problems + + align:start position:0% + + + + align:start position:0% + +so let's draw the recursion tree + + align:start position:0% +so let's draw the recursion tree + + + align:start position:0% +so let's draw the recursion tree +for this recursive algorithm as we've + + align:start position:0% +for this recursive algorithm as we've + + + align:start position:0% +for this recursive algorithm as we've +done it so far + + align:start position:0% +done it so far + + + align:start position:0% +done it so far +so at the top we let me make a little + + align:start position:0% +so at the top we let me make a little + + + align:start position:0% +so at the top we let me make a little +bit of space + + align:start position:0% + + + + align:start position:0% + +at the top we are calling f of n + + align:start position:0% +at the top we are calling f of n + + + align:start position:0% +at the top we are calling f of n +and then that calls f of n minus 1 + + align:start position:0% +and then that calls f of n minus 1 + + + align:start position:0% +and then that calls f of n minus 1 +and f of n minus two and it does an + + align:start position:0% +and f of n minus two and it does an + + + align:start position:0% +and f of n minus two and it does an +addition up here + + align:start position:0% +addition up here + + + align:start position:0% +addition up here +and then this calls f of n minus two + + align:start position:0% +and then this calls f of n minus two + + + align:start position:0% +and then this calls f of n minus two +and this calls f of n minus three + + align:start position:0% +and this calls f of n minus three + + + align:start position:0% +and this calls f of n minus three +this calls f of n minus three + + align:start position:0% +this calls f of n minus three + + + align:start position:0% +this calls f of n minus three +and this calls f of n minus 4. + + align:start position:0% + + + + align:start position:0% + +okay and we notice that + + align:start position:0% + + + + align:start position:0% + +this sub problem is the same as this sub + + align:start position:0% +this sub problem is the same as this sub + + + align:start position:0% +this sub problem is the same as this sub +problem + + align:start position:0% +problem + + + align:start position:0% +problem +so to compute f of n minus 1 i need f of + + align:start position:0% +so to compute f of n minus 1 i need f of + + + align:start position:0% +so to compute f of n minus 1 i need f of +n minus 3 and also to compute f of n + + align:start position:0% +n minus 3 and also to compute f of n + + + align:start position:0% +n minus 3 and also to compute f of n +minus 2 i need f of n minus 3. + + align:start position:0% +minus 2 i need f of n minus 3. + + + align:start position:0% +minus 2 i need f of n minus 3. +so why are we computing it twice let's + + align:start position:0% +so why are we computing it twice let's + + + align:start position:0% +so why are we computing it twice let's +just do it once + + align:start position:0% +just do it once + + + align:start position:0% +just do it once +when we solve it let's write it in a + + align:start position:0% +when we solve it let's write it in a + + + align:start position:0% +when we solve it let's write it in a +table somewhere + + align:start position:0% +table somewhere + + + align:start position:0% +table somewhere +and then when we need it again we'll + + align:start position:0% +and then when we need it again we'll + + + align:start position:0% +and then when we need it again we'll +just reuse that value question + + align:start position:0% + + + + align:start position:0% + +f of n minus 2 is also shared so let me + + align:start position:0% +f of n minus 2 is also shared so let me + + + align:start position:0% +f of n minus 2 is also shared so let me +use a different + + align:start position:0% +use a different + + + align:start position:0% +use a different +symbol f of n minus 2 is already + + align:start position:0% +symbol f of n minus 2 is already + + + align:start position:0% +symbol f of n minus 2 is already +here so this was at the same level but + + align:start position:0% +here so this was at the same level but + + + align:start position:0% +here so this was at the same level but +we also get shared reuse + + align:start position:0% +we also get shared reuse + + + align:start position:0% +we also get shared reuse +between different levels in fact i + + align:start position:0% +between different levels in fact i + + + align:start position:0% +between different levels in fact i +wouldn't even call f of n minus 3 + + align:start position:0% +wouldn't even call f of n minus 3 + + + align:start position:0% +wouldn't even call f of n minus 3 +because this whole part + + align:start position:0% +because this whole part + + + align:start position:0% +because this whole part +doesn't need to be computed a second + + align:start position:0% +doesn't need to be computed a second + + + align:start position:0% +doesn't need to be computed a second +time if i already computed it here + + align:start position:0% +time if i already computed it here + + + align:start position:0% +time if i already computed it here +it doesn't matter which one comes first + + align:start position:0% +it doesn't matter which one comes first + + + align:start position:0% +it doesn't matter which one comes first +let's say this one comes first once this + + align:start position:0% +let's say this one comes first once this + + + align:start position:0% +let's say this one comes first once this +is done + + align:start position:0% +is done + + + align:start position:0% +is done +i can write it down and reuse it over + + align:start position:0% +i can write it down and reuse it over + + + align:start position:0% +i can write it down and reuse it over +here + + align:start position:0% +here + + + align:start position:0% +here +okay but actually and then in here we're + + align:start position:0% +okay but actually and then in here we're + + + align:start position:0% +okay but actually and then in here we're +going to call f of n minus 3 + + align:start position:0% +going to call f of n minus 3 + + + align:start position:0% +going to call f of n minus 3 +so there's still a another computation + + align:start position:0% +so there's still a another computation + + + align:start position:0% +so there's still a another computation +of f of n minus 3. + + align:start position:0% +of f of n minus 3. + + + align:start position:0% +of f of n minus 3. +when that one's done i won't need to do + + align:start position:0% +when that one's done i won't need to do + + + align:start position:0% +when that one's done i won't need to do +any do this recursively + + align:start position:0% +any do this recursively + + + align:start position:0% +any do this recursively +okay so magically this is going to make + + align:start position:0% +okay so magically this is going to make + + + align:start position:0% +okay so magically this is going to make +this algorithm efficient with this + + align:start position:0% +this algorithm efficient with this + + + align:start position:0% +this algorithm efficient with this +very simple tweak let me write down the + + align:start position:0% +very simple tweak let me write down the + + + align:start position:0% +very simple tweak let me write down the +tweak more explicitly + + align:start position:0% +tweak more explicitly + + + align:start position:0% +tweak more explicitly +i won't write code here but + + align:start position:0% +i won't write code here but + + + align:start position:0% +i won't write code here but +just describe it as a data structure + + align:start position:0% +just describe it as a data structure + + + align:start position:0% +just describe it as a data structure +so we're going to maintain our good + + align:start position:0% +so we're going to maintain our good + + + align:start position:0% +so we're going to maintain our good +friend the dictionary + + align:start position:0% + + + + align:start position:0% + +which is abstract data type or interface + + align:start position:0% +which is abstract data type or interface + + + align:start position:0% +which is abstract data type or interface +we could use different data structures + + align:start position:0% +we could use different data structures + + + align:start position:0% +we could use different data structures +to do it but we're going to map + + align:start position:0% +to do it but we're going to map + + + align:start position:0% +to do it but we're going to map +sub problems to their solutions + + align:start position:0% +sub problems to their solutions + + + align:start position:0% +sub problems to their solutions +at least the ones that we've solved + + align:start position:0% +at least the ones that we've solved + + + align:start position:0% +at least the ones that we've solved +already + + align:start position:0% + + + + align:start position:0% + +and usually we can do this with just a + + align:start position:0% +and usually we can do this with just a + + + align:start position:0% +and usually we can do this with just a +direct access array + + align:start position:0% +direct access array + + + align:start position:0% +direct access array +though you could use a hash table just + + align:start position:0% +though you could use a hash table just + + + align:start position:0% +though you could use a hash table just +get expected bounds + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +uh when we + + align:start position:0% + + + + align:start position:0% + +write the code for our recursive + + align:start position:0% +write the code for our recursive + + + align:start position:0% +write the code for our recursive +function so in general once we have a + + align:start position:0% +function so in general once we have a + + + align:start position:0% +function so in general once we have a +sort bot + + align:start position:0% +sort bot + + + align:start position:0% +sort bot +description we can turn this into code + + align:start position:0% +description we can turn this into code + + + align:start position:0% +description we can turn this into code +right we define + + align:start position:0% +right we define + + + align:start position:0% +right we define +f of i and it says am i in a base case + + align:start position:0% +f of i and it says am i in a base case + + + align:start position:0% +f of i and it says am i in a base case +if so return this + + align:start position:0% +if so return this + + + align:start position:0% +if so return this +otherwise do this recursive call that's + + align:start position:0% +otherwise do this recursive call that's + + + align:start position:0% +otherwise do this recursive call that's +our recursive algorithm + + align:start position:0% +our recursive algorithm + + + align:start position:0% +our recursive algorithm +but we're going to do a little more now + + align:start position:0% +but we're going to do a little more now + + + align:start position:0% +but we're going to do a little more now +at first we're going to check + + align:start position:0% + + + + align:start position:0% + +whether this sub problem that we're + + align:start position:0% +whether this sub problem that we're + + + align:start position:0% +whether this sub problem that we're +trying to solve has already been solved + + align:start position:0% + + + + align:start position:0% + +and if so we return that stored solution + + align:start position:0% +and if so we return that stored solution + + + align:start position:0% +and if so we return that stored solution +that's the easy case but it might not + + align:start position:0% +that's the easy case but it might not + + + align:start position:0% +that's the easy case but it might not +exist + + align:start position:0% + + + + align:start position:0% + +and then we'll we'll compute it in the + + align:start position:0% +and then we'll we'll compute it in the + + + align:start position:0% +and then we'll we'll compute it in the +usual way + + align:start position:0% +usual way + + + align:start position:0% +usual way +so what the code then would look like to + + align:start position:0% +so what the code then would look like to + + + align:start position:0% +so what the code then would look like to +define + + align:start position:0% +define + + + align:start position:0% +define +f of i is first we check is i in our + + align:start position:0% +f of i is first we check is i in our + + + align:start position:0% +f of i is first we check is i in our +in our data structure this is usually + + align:start position:0% +in our data structure this is usually + + + align:start position:0% +in our data structure this is usually +called + + align:start position:0% +called + + + align:start position:0% +called +the memo + + align:start position:0% +the memo + + + align:start position:0% +the memo +so we say is this sub problem is i in my + + align:start position:0% +so we say is this sub problem is i in my + + + align:start position:0% +so we say is this sub problem is i in my +memo + + align:start position:0% +memo + + + align:start position:0% +memo +data structure if so just return memo of + + align:start position:0% +data structure if so just return memo of + + + align:start position:0% +data structure if so just return memo of +i done no recursion necessary + + align:start position:0% +i done no recursion necessary + + + align:start position:0% +i done no recursion necessary +otherwise check if i'm a base case if so + + align:start position:0% +otherwise check if i'm a base case if so + + + align:start position:0% +otherwise check if i'm a base case if so +done otherwise recurse so recursively + + align:start position:0% +done otherwise recurse so recursively + + + align:start position:0% +done otherwise recurse so recursively +call f of i minus 1 and f + + align:start position:0% +call f of i minus 1 and f + + + align:start position:0% +call f of i minus 1 and f +minus 2. and in this recursion we can + + align:start position:0% +minus 2. and in this recursion we can + + + align:start position:0% +minus 2. and in this recursion we can +see that after we call f of i minus 1 + + align:start position:0% +see that after we call f of i minus 1 + + + align:start position:0% +see that after we call f of i minus 1 +in fact it will have already computed f + + align:start position:0% +in fact it will have already computed f + + + align:start position:0% +in fact it will have already computed f +of i minus 2. so while this call is + + align:start position:0% +of i minus 2. so while this call is + + + align:start position:0% +of i minus 2. so while this call is +recursive + + align:start position:0% +recursive + + + align:start position:0% +recursive +this one will immediately terminate + + align:start position:0% +this one will immediately terminate + + + align:start position:0% +this one will immediately terminate +because i minus 2 will already be in the + + align:start position:0% +because i minus 2 will already be in the + + + align:start position:0% +because i minus 2 will already be in the +memo table + + align:start position:0% +memo table + + + align:start position:0% +memo table +and so if you think about what happens + + align:start position:0% +and so if you think about what happens + + + align:start position:0% +and so if you think about what happens +in fact we'll just have recursion down + + align:start position:0% +in fact we'll just have recursion down + + + align:start position:0% +in fact we'll just have recursion down +the left branch + + align:start position:0% +the left branch + + + align:start position:0% +the left branch +of this thing and all the right branches + + align:start position:0% +of this thing and all the right branches + + + align:start position:0% +of this thing and all the right branches +will be free we can just look things up + + align:start position:0% +will be free we can just look things up + + + align:start position:0% +will be free we can just look things up +in the memo table + + align:start position:0% +in the memo table + + + align:start position:0% +in the memo table +so what is the overall running time for + + align:start position:0% +so what is the overall running time for + + + align:start position:0% +so what is the overall running time for +fibonacci + + align:start position:0% + + + + align:start position:0% + +this should be order n + + align:start position:0% +this should be order n + + + align:start position:0% +this should be order n +why is it order n this is number of + + align:start position:0% +why is it order n this is number of + + + align:start position:0% +why is it order n this is number of +additions + + align:start position:0% + + + + align:start position:0% + +come back to that in a second + + align:start position:0% + + + + align:start position:0% + +in general the way to analyze an + + align:start position:0% +in general the way to analyze an + + + align:start position:0% +in general the way to analyze an +algorithm like this that uses + + align:start position:0% +algorithm like this that uses + + + align:start position:0% +algorithm like this that uses +memorization is we just count + + align:start position:0% +memorization is we just count + + + align:start position:0% +memorization is we just count +how many different sub-problems are + + align:start position:0% +how many different sub-problems are + + + align:start position:0% +how many different sub-problems are +there because once we solve the + + align:start position:0% +there because once we solve the + + + align:start position:0% +there because once we solve the +sub-problem we will never solve it again + + align:start position:0% +sub-problem we will never solve it again + + + align:start position:0% +sub-problem we will never solve it again +that's the whole idea of a memo table so + + align:start position:0% +that's the whole idea of a memo table so + + + align:start position:0% +that's the whole idea of a memo table so +we will solve each sub-problem + + align:start position:0% +we will solve each sub-problem + + + align:start position:0% +we will solve each sub-problem +at most once and so we just need to + + align:start position:0% +at most once and so we just need to + + + align:start position:0% +at most once and so we just need to +count how much time does it take to + + align:start position:0% +count how much time does it take to + + + align:start position:0% +count how much time does it take to +solve + + align:start position:0% +solve + + + align:start position:0% +solve +every subproblem and here you can see + + align:start position:0% +every subproblem and here you can see + + + align:start position:0% +every subproblem and here you can see +it's constant + + align:start position:0% +it's constant + + + align:start position:0% +it's constant +either it's a base case and it takes + + align:start position:0% +either it's a base case and it takes + + + align:start position:0% +either it's a base case and it takes +constant time or + + align:start position:0% +constant time or + + + align:start position:0% +constant time or +we recursively call these things but + + align:start position:0% +we recursively call these things but + + + align:start position:0% +we recursively call these things but +those are different sub problems so + + align:start position:0% +those are different sub problems so + + + align:start position:0% +those are different sub problems so +we're going to count those later + + align:start position:0% +we're going to count those later + + + align:start position:0% +we're going to count those later +and then the work that's actually done + + align:start position:0% +and then the work that's actually done + + + align:start position:0% +and then the work that's actually done +by this recurrence is a single addition + + align:start position:0% +by this recurrence is a single addition + + + align:start position:0% +by this recurrence is a single addition +so in fact it's n additions to compute f + + align:start position:0% +so in fact it's n additions to compute f + + + align:start position:0% +so in fact it's n additions to compute f +n will be exactly n additions + + align:start position:0% +n will be exactly n additions + + + align:start position:0% +n will be exactly n additions +so it turns out to be very nice closed + + align:start position:0% +so it turns out to be very nice closed + + + align:start position:0% +so it turns out to be very nice closed +form in this case + + align:start position:0% +form in this case + + + align:start position:0% +form in this case +um it should be exactly n sub problems + + align:start position:0% +um it should be exactly n sub problems + + + align:start position:0% +um it should be exactly n sub problems +to compute f of n and because we start + + align:start position:0% +to compute f of n and because we start + + + align:start position:0% +to compute f of n and because we start +stop + + align:start position:0% +stop + + + align:start position:0% +stop +at one and each one has + + align:start position:0% +at one and each one has + + + align:start position:0% +at one and each one has +one addition involved i guess not the + + align:start position:0% +one addition involved i guess not the + + + align:start position:0% +one addition involved i guess not the +base case so maybe n minus two + + align:start position:0% +base case so maybe n minus two + + + align:start position:0% +base case so maybe n minus two +okay definitely order n uh + + align:start position:0% +okay definitely order n uh + + + align:start position:0% +okay definitely order n uh +now there's this one subtlety uh which + + align:start position:0% +now there's this one subtlety uh which + + + align:start position:0% +now there's this one subtlety uh which +let's forget about dynamic programming + + align:start position:0% +let's forget about dynamic programming + + + align:start position:0% +let's forget about dynamic programming +for a moment and go back to + + align:start position:0% +for a moment and go back to + + + align:start position:0% +for a moment and go back to +good old lecture one and two talking + + align:start position:0% +good old lecture one and two talking + + + align:start position:0% +good old lecture one and two talking +about the word ram model of computation + + align:start position:0% +about the word ram model of computation + + + align:start position:0% +about the word ram model of computation +um a question here that usually doesn't + + align:start position:0% +um a question here that usually doesn't + + + align:start position:0% +um a question here that usually doesn't +matter + + align:start position:0% +matter + + + align:start position:0% +matter +in this class usually we assume + + align:start position:0% +in this class usually we assume + + + align:start position:0% +in this class usually we assume +additions take constant time + + align:start position:0% +additions take constant time + + + align:start position:0% +additions take constant time +and we usually do that because it's + + align:start position:0% +and we usually do that because it's + + + align:start position:0% +and we usually do that because it's +usually true and in general our model is + + align:start position:0% +usually true and in general our model is + + + align:start position:0% +usually true and in general our model is +that w + + align:start position:0% +that w + + + align:start position:0% +that w +bit additions + + align:start position:0% +bit additions + + + align:start position:0% +bit additions +where w is our machine word size + + align:start position:0% +where w is our machine word size + + + align:start position:0% +where w is our machine word size +takes constant time + + align:start position:0% + + + + align:start position:0% + +but for this problem and this problem + + align:start position:0% +but for this problem and this problem + + + align:start position:0% +but for this problem and this problem +only pretty much for fibonacci numbers + + align:start position:0% +only pretty much for fibonacci numbers + + + align:start position:0% +only pretty much for fibonacci numbers +i happen to know that the fibonacci + + align:start position:0% +i happen to know that the fibonacci + + + align:start position:0% +i happen to know that the fibonacci +numbers grow exponentially so to write + + align:start position:0% +numbers grow exponentially so to write + + + align:start position:0% +numbers grow exponentially so to write +them down + + align:start position:0% +them down + + + align:start position:0% +them down +actually requires uh theta n bits + + align:start position:0% +actually requires uh theta n bits + + + align:start position:0% +actually requires uh theta n bits +because they are some constant to the n + + align:start position:0% +because they are some constant to the n + + + align:start position:0% +because they are some constant to the n +power and so they're actually really big + + align:start position:0% +power and so they're actually really big + + + align:start position:0% +power and so they're actually really big +uh potential n is probably bigger than w + + align:start position:0% +uh potential n is probably bigger than w + + + align:start position:0% +uh potential n is probably bigger than w +usually you + + align:start position:0% +usually you + + + align:start position:0% +usually you +think of problems that are much bigger + + align:start position:0% +think of problems that are much bigger + + + align:start position:0% +think of problems that are much bigger +than 64 or whatever your word size + + align:start position:0% +than 64 or whatever your word size + + + align:start position:0% +than 64 or whatever your word size +happens to be + + align:start position:0% +happens to be + + + align:start position:0% +happens to be +we do assume that w is at least log n + + align:start position:0% +we do assume that w is at least log n + + + align:start position:0% +we do assume that w is at least log n +but n is + + align:start position:0% +but n is + + + align:start position:0% +but n is +probably bigger than w might be bigger + + align:start position:0% +probably bigger than w might be bigger + + + align:start position:0% +probably bigger than w might be bigger +or smaller we don't know + + align:start position:0% +or smaller we don't know + + + align:start position:0% +or smaller we don't know +and in general to do an n bit addition + + align:start position:0% +and in general to do an n bit addition + + + align:start position:0% +and in general to do an n bit addition +these are n bit additions + + align:start position:0% +these are n bit additions + + + align:start position:0% +these are n bit additions +is going to take a ceiling of n over w + + align:start position:0% +is going to take a ceiling of n over w + + + align:start position:0% +is going to take a ceiling of n over w +time so in the end we will spend + + align:start position:0% +time so in the end we will spend + + + align:start position:0% +time so in the end we will spend +this times n because we have to do that + + align:start position:0% +this times n because we have to do that + + + align:start position:0% +this times n because we have to do that +many of them which + + align:start position:0% +many of them which + + + align:start position:0% +many of them which +is n plus n squared over w + + align:start position:0% +is n plus n squared over w + + + align:start position:0% +is n plus n squared over w +time so a bit of a weird running time + + align:start position:0% +time so a bit of a weird running time + + + align:start position:0% +time so a bit of a weird running time +but + + align:start position:0% +but + + + align:start position:0% +but +it's polynomial whereas this original + + align:start position:0% +it's polynomial whereas this original + + + align:start position:0% +it's polynomial whereas this original +recursive algorithm was exponential + + align:start position:0% +recursive algorithm was exponential + + + align:start position:0% +recursive algorithm was exponential +here using this one simple idea of just + + align:start position:0% +here using this one simple idea of just + + + align:start position:0% +here using this one simple idea of just +remembering the work we've done suddenly + + align:start position:0% +remembering the work we've done suddenly + + + align:start position:0% +remembering the work we've done suddenly +this exponential time algorithm becomes + + align:start position:0% +this exponential time algorithm becomes + + + align:start position:0% +this exponential time algorithm becomes +polynomial + + align:start position:0% +polynomial + + + align:start position:0% +polynomial +why because we have few sub-problems we + + align:start position:0% +why because we have few sub-problems we + + + align:start position:0% +why because we have few sub-problems we +had + + align:start position:0% +had + + + align:start position:0% +had +n sub-problems + + align:start position:0% +n sub-problems + + + align:start position:0% +n sub-problems +for each subproblem we could write a + + align:start position:0% +for each subproblem we could write a + + + align:start position:0% +for each subproblem we could write a +recurrence relation that if we already + + align:start position:0% +recurrence relation that if we already + + + align:start position:0% +recurrence relation that if we already +knew + + align:start position:0% +knew + + + align:start position:0% +knew +the solutions to smaller sub-problems we + + align:start position:0% +the solutions to smaller sub-problems we + + + align:start position:0% +the solutions to smaller sub-problems we +could compute + + align:start position:0% +could compute + + + align:start position:0% +could compute +this bigger problem very efficiently + + align:start position:0% +this bigger problem very efficiently + + + align:start position:0% +this bigger problem very efficiently +this happened to be constant time + + align:start position:0% +this happened to be constant time + + + align:start position:0% +this happened to be constant time +or constant additions + + align:start position:0% + + + + align:start position:0% + +n over w time but as long as this is + + align:start position:0% +n over w time but as long as this is + + + align:start position:0% +n over w time but as long as this is +polynomial + + align:start position:0% +polynomial + + + align:start position:0% +polynomial +and this is polynomial we're happy + + align:start position:0% +and this is polynomial we're happy + + + align:start position:0% +and this is polynomial we're happy +because + + align:start position:0% +because + + + align:start position:0% +because +we we have this nice formula that the + + align:start position:0% +we we have this nice formula that the + + + align:start position:0% +we we have this nice formula that the +time + + align:start position:0% +time + + + align:start position:0% +time +it takes is at most the sum over all sub + + align:start position:0% +it takes is at most the sum over all sub + + + align:start position:0% +it takes is at most the sum over all sub +problems + + align:start position:0% + + + + align:start position:0% + +of the relation time + + align:start position:0% + + + + align:start position:0% + +okay so i'm referring to subproblems the + + align:start position:0% +okay so i'm referring to subproblems the + + + align:start position:0% +okay so i'm referring to subproblems the +number of them and the time it takes to + + align:start position:0% +number of them and the time it takes to + + + align:start position:0% +number of them and the time it takes to +evaluate this ignoring the recursive + + align:start position:0% +evaluate this ignoring the recursive + + + align:start position:0% +evaluate this ignoring the recursive +calls that's important this is the + + align:start position:0% +calls that's important this is the + + + align:start position:0% +calls that's important this is the +uh non-recursive part + + align:start position:0% + + + + align:start position:0% + +in the notes i call this non-recursive + + align:start position:0% +in the notes i call this non-recursive + + + align:start position:0% +in the notes i call this non-recursive +work + + align:start position:0% + + + + align:start position:0% + +so this formula gives us a way to bound + + align:start position:0% +so this formula gives us a way to bound + + + align:start position:0% +so this formula gives us a way to bound +the running time + + align:start position:0% +the running time + + + align:start position:0% +the running time +of one of these algorithms if we use + + align:start position:0% +of one of these algorithms if we use + + + align:start position:0% +of one of these algorithms if we use +memoization + + align:start position:0% +memoization + + + align:start position:0% +memoization +without memoization this is not true + + align:start position:0% +without memoization this is not true + + + align:start position:0% +without memoization this is not true +fibonacci took exponential time + + align:start position:0% +fibonacci took exponential time + + + align:start position:0% +fibonacci took exponential time +but if we add memoization we know that + + align:start position:0% +but if we add memoization we know that + + + align:start position:0% +but if we add memoization we know that +we only solve each sub problem once + + align:start position:0% +we only solve each sub problem once + + + align:start position:0% +we only solve each sub problem once +and so we just need to see for each one + + align:start position:0% +and so we just need to see for each one + + + align:start position:0% +and so we just need to see for each one +how much did it cost me to compute it + + align:start position:0% +how much did it cost me to compute it + + + align:start position:0% +how much did it cost me to compute it +assuming all the recursion work is free + + align:start position:0% +assuming all the recursion work is free + + + align:start position:0% +assuming all the recursion work is free +because that's already taken into + + align:start position:0% +because that's already taken into + + + align:start position:0% +because that's already taken into +account by the summation + + align:start position:0% +account by the summation + + + align:start position:0% +account by the summation +so in particular this summation is at + + align:start position:0% +so in particular this summation is at + + + align:start position:0% +so in particular this summation is at +most the number of sub-problems + + align:start position:0% +most the number of sub-problems + + + align:start position:0% +most the number of sub-problems +times the time per sub-problem which in + + align:start position:0% +times the time per sub-problem which in + + + align:start position:0% +times the time per sub-problem which in +this case is order n + + align:start position:0% +this case is order n + + + align:start position:0% +this case is order n +we could try to apply that analysis to + + align:start position:0% +we could try to apply that analysis to + + + align:start position:0% +we could try to apply that analysis to +merge sort because + + align:start position:0% +merge sort because + + + align:start position:0% +merge sort because +after all this is also a recursive + + align:start position:0% +after all this is also a recursive + + + align:start position:0% +after all this is also a recursive +algorithm + + align:start position:0% +algorithm + + + align:start position:0% +algorithm +it happens to not benefit from + + align:start position:0% +it happens to not benefit from + + + align:start position:0% +it happens to not benefit from +memoization but we could throw in + + align:start position:0% +memoization but we could throw in + + + align:start position:0% +memoization but we could throw in +memorization it wouldn't hurt us + + align:start position:0% +memorization it wouldn't hurt us + + + align:start position:0% +memorization it wouldn't hurt us +but if you think about the call graph + + align:start position:0% +but if you think about the call graph + + + align:start position:0% +but if you think about the call graph +here which is like + + align:start position:0% +here which is like + + + align:start position:0% +here which is like +s of zero n which calls s + + align:start position:0% +s of zero n which calls s + + + align:start position:0% +s of zero n which calls s +of n of zero n over two + + align:start position:0% +of n of zero n over two + + + align:start position:0% +of n of zero n over two +and s of n over two n + + align:start position:0% +and s of n over two n + + + align:start position:0% +and s of n over two n +and so on it has the same picture but + + align:start position:0% +and so on it has the same picture but + + + align:start position:0% +and so on it has the same picture but +there's actually + + align:start position:0% +there's actually + + + align:start position:0% +there's actually +no common substructure here you'll never + + align:start position:0% +no common substructure here you'll never + + + align:start position:0% +no common substructure here you'll never +see a repeated sub-problem because + + align:start position:0% +see a repeated sub-problem because + + + align:start position:0% +see a repeated sub-problem because +this range is completely disjoint from + + align:start position:0% +this range is completely disjoint from + + + align:start position:0% +this range is completely disjoint from +this range + + align:start position:0% +this range + + + align:start position:0% +this range +but you could throw in memorization and + + align:start position:0% +but you could throw in memorization and + + + align:start position:0% +but you could throw in memorization and +try to analyze in the same way and say + + align:start position:0% +try to analyze in the same way and say + + + align:start position:0% +try to analyze in the same way and say +well how many sub problems are there + + align:start position:0% +well how many sub problems are there + + + align:start position:0% +well how many sub problems are there +well looks like there's there's n + + align:start position:0% +well looks like there's there's n + + + align:start position:0% +well looks like there's there's n +choices for i + + align:start position:0% +choices for i + + + align:start position:0% +choices for i +and not quite n choices but + + align:start position:0% +and not quite n choices but + + + align:start position:0% +and not quite n choices but +in general it's at most n squared + + align:start position:0% +in general it's at most n squared + + + align:start position:0% +in general it's at most n squared +different choices in fact it's the + + align:start position:0% +different choices in fact it's the + + + align:start position:0% +different choices in fact it's the +triangular number + + align:start position:0% +triangular number + + + align:start position:0% +triangular number +sum of i equals 1 to n of i + + align:start position:0% +sum of i equals 1 to n of i + + + align:start position:0% +sum of i equals 1 to n of i +different possible choices for i and j + + align:start position:0% +different possible choices for i and j + + + align:start position:0% +different possible choices for i and j +but this is theta n squared + + align:start position:0% +but this is theta n squared + + + align:start position:0% +but this is theta n squared +sub problems which seems not so good + + align:start position:0% +sub problems which seems not so good + + + align:start position:0% +sub problems which seems not so good +and then how much time are we spending + + align:start position:0% +and then how much time are we spending + + + align:start position:0% +and then how much time are we spending +for per sub problem well + + align:start position:0% +for per sub problem well + + + align:start position:0% +for per sub problem well +to solve s of i j we have to merge + + align:start position:0% +to solve s of i j we have to merge + + + align:start position:0% +to solve s of i j we have to merge +about that many elements we know merge + + align:start position:0% +about that many elements we know merge + + + align:start position:0% +about that many elements we know merge +takes linear time and so this takes + + align:start position:0% +takes linear time and so this takes + + + align:start position:0% +takes linear time and so this takes +uh theta j minus i time + + align:start position:0% +uh theta j minus i time + + + align:start position:0% +uh theta j minus i time +to evaluate and so + + align:start position:0% +to evaluate and so + + + align:start position:0% +to evaluate and so +uh what we'd like to do is sum over all + + align:start position:0% +uh what we'd like to do is sum over all + + + align:start position:0% +uh what we'd like to do is sum over all +the sub-problems + + align:start position:0% +the sub-problems + + + align:start position:0% +the sub-problems +of j minus i this is the uh not + + align:start position:0% +of j minus i this is the uh not + + + align:start position:0% +of j minus i this is the uh not +triangular number but the tetrahedral + + align:start position:0% +triangular number but the tetrahedral + + + align:start position:0% +triangular number but the tetrahedral +number i guess + + align:start position:0% +number i guess + + + align:start position:0% +number i guess +and so we end up that the running time + + align:start position:0% +and so we end up that the running time + + + align:start position:0% +and so we end up that the running time +is at most + + align:start position:0% +is at most + + + align:start position:0% +is at most +n cubed + + align:start position:0% + + + + align:start position:0% + +great um so it's true that n log n is + + align:start position:0% +great um so it's true that n log n is + + + align:start position:0% +great um so it's true that n log n is +less than or equal to n cubed + + align:start position:0% +less than or equal to n cubed + + + align:start position:0% +less than or equal to n cubed +but obviously not terribly useful this + + align:start position:0% +but obviously not terribly useful this + + + align:start position:0% +but obviously not terribly useful this +algorithm by the way we already know + + align:start position:0% +algorithm by the way we already know + + + align:start position:0% +algorithm by the way we already know +how to analyze it is indeed n log n and + + align:start position:0% +how to analyze it is indeed n log n and + + + align:start position:0% +how to analyze it is indeed n log n and +the running time turns out to be + + align:start position:0% +the running time turns out to be + + + align:start position:0% +the running time turns out to be +theta n log n so + + align:start position:0% +theta n log n so + + + align:start position:0% +theta n log n so +sometimes this is this equation is not + + align:start position:0% +sometimes this is this equation is not + + + align:start position:0% +sometimes this is this equation is not +what you want to use + + align:start position:0% +what you want to use + + + align:start position:0% +what you want to use +but often it's good enough and + + align:start position:0% +but often it's good enough and + + + align:start position:0% +but often it's good enough and +especially if you just want to get a + + align:start position:0% +especially if you just want to get a + + + align:start position:0% +especially if you just want to get a +polynomial upper bound and then you can + + align:start position:0% +polynomial upper bound and then you can + + + align:start position:0% +polynomial upper bound and then you can +try to optimize it later + + align:start position:0% +try to optimize it later + + + align:start position:0% +try to optimize it later +this will give you a polynomial upper + + align:start position:0% +this will give you a polynomial upper + + + align:start position:0% +this will give you a polynomial upper +bound as long as the number of + + align:start position:0% +bound as long as the number of + + + align:start position:0% +bound as long as the number of +subproblems is polynomial + + align:start position:0% +subproblems is polynomial + + + align:start position:0% +subproblems is polynomial +and the time per subproblem is + + align:start position:0% +and the time per subproblem is + + + align:start position:0% +and the time per subproblem is +polynomial and indeed + + align:start position:0% +polynomial and indeed + + + align:start position:0% +polynomial and indeed +n cubed is polynomial it's not a great + + align:start position:0% +n cubed is polynomial it's not a great + + + align:start position:0% +n cubed is polynomial it's not a great +polynomial but + + align:start position:0% +polynomial but + + + align:start position:0% +polynomial but +this is a an alternate way to analyze + + align:start position:0% +this is a an alternate way to analyze + + + align:start position:0% +this is a an alternate way to analyze +merge sort obviously + + align:start position:0% +merge sort obviously + + + align:start position:0% +merge sort obviously +don't do this for merge sort but it + + align:start position:0% +don't do this for merge sort but it + + + align:start position:0% +don't do this for merge sort but it +illustrates the + + align:start position:0% +illustrates the + + + align:start position:0% +illustrates the +technique good so far + + align:start position:0% +technique good so far + + + align:start position:0% +technique good so far +any questions all right + + align:start position:0% +any questions all right + + + align:start position:0% +any questions all right +uh let me remember where we are + + align:start position:0% + + + + align:start position:0% + +cool so the next thing i'd like to do is + + align:start position:0% +cool so the next thing i'd like to do is + + + align:start position:0% +cool so the next thing i'd like to do is +uh + + align:start position:0% +uh + + + align:start position:0% +uh +show you one more algorithm that we've + + align:start position:0% +show you one more algorithm that we've + + + align:start position:0% +show you one more algorithm that we've +already seen in this class that fits + + align:start position:0% +already seen in this class that fits + + + align:start position:0% +already seen in this class that fits +very nicely into this structure + + align:start position:0% +very nicely into this structure + + + align:start position:0% +very nicely into this structure +arguably is a dynamic program and that + + align:start position:0% +arguably is a dynamic program and that + + + align:start position:0% +arguably is a dynamic program and that +is + + align:start position:0% +is + + + align:start position:0% +is +uh dag shortest paths oh so just to + + align:start position:0% +uh dag shortest paths oh so just to + + + align:start position:0% +uh dag shortest paths oh so just to +close the loop here + + align:start position:0% +close the loop here + + + align:start position:0% +close the loop here +when i say dynamic programming i mean + + align:start position:0% +when i say dynamic programming i mean + + + align:start position:0% +when i say dynamic programming i mean +recursion with memoization + + align:start position:0% +recursion with memoization + + + align:start position:0% +recursion with memoization +i mean we take we we + + align:start position:0% +i mean we take we we + + + align:start position:0% +i mean we take we we +write a recursive piece of code which is + + align:start position:0% +write a recursive piece of code which is + + + align:start position:0% +write a recursive piece of code which is +like + + align:start position:0% +like + + + align:start position:0% +like +def f of some args um + + align:start position:0% +def f of some args um + + + align:start position:0% +def f of some args um +some you know sub-problem specification + + align:start position:0% + + + + align:start position:0% + +we check is the sub-problem uh + + align:start position:0% +we check is the sub-problem uh + + + align:start position:0% +we check is the sub-problem uh +in the memo table if so + + align:start position:0% +in the memo table if so + + + align:start position:0% +in the memo table if so +uh return + + align:start position:0% + + + + align:start position:0% + +memo of subproblem + + align:start position:0% + + + + align:start position:0% + +and otherwise + + align:start position:0% + + + + align:start position:0% + +check if it's a base case if and solve + + align:start position:0% +check if it's a base case if and solve + + + align:start position:0% +check if it's a base case if and solve +it if it's a base case and otherwise + + align:start position:0% +it if it's a base case and otherwise + + + align:start position:0% +it if it's a base case and otherwise +write the uh + + align:start position:0% + + + + align:start position:0% + +recurrence recurse via + + align:start position:0% +recurrence recurse via + + + align:start position:0% +recurrence recurse via +relation + + align:start position:0% + + + + align:start position:0% + +and set the memo table + + align:start position:0% + + + + align:start position:0% + +of the subproblem to be one of those + + align:start position:0% +of the subproblem to be one of those + + + align:start position:0% +of the subproblem to be one of those +things + + align:start position:0% +things + + + align:start position:0% +things +okay so this is the generic dynamic + + align:start position:0% +okay so this is the generic dynamic + + + align:start position:0% +okay so this is the generic dynamic +program + + align:start position:0% +program + + + align:start position:0% +program +and implicitly i'm writing fibonacci + + align:start position:0% +and implicitly i'm writing fibonacci + + + align:start position:0% +and implicitly i'm writing fibonacci +in that way and all of the dynamic + + align:start position:0% +in that way and all of the dynamic + + + align:start position:0% +in that way and all of the dynamic +programs have this implicit structure + + align:start position:0% +programs have this implicit structure + + + align:start position:0% +programs have this implicit structure +where i start with a memo table which is + + align:start position:0% +where i start with a memo table which is + + + align:start position:0% +where i start with a memo table which is +empty + + align:start position:0% + + + + align:start position:0% + +and i always just check if i'm in the + + align:start position:0% +and i always just check if i'm in the + + + align:start position:0% +and i always just check if i'm in the +memo table + + align:start position:0% +memo table + + + align:start position:0% +memo table +if i am i return it otherwise i compute + + align:start position:0% +if i am i return it otherwise i compute + + + align:start position:0% +if i am i return it otherwise i compute +according to this recursive relation + + align:start position:0% +according to this recursive relation + + + align:start position:0% +according to this recursive relation +by recursively calling f + + align:start position:0% + + + + align:start position:0% + +and that's it so this is every dp + + align:start position:0% +and that's it so this is every dp + + + align:start position:0% +and that's it so this is every dp +algorithm is going to have that + + align:start position:0% +algorithm is going to have that + + + align:start position:0% +algorithm is going to have that +structure + + align:start position:0% +structure + + + align:start position:0% +structure +and it's just using recursion and + + align:start position:0% +and it's just using recursion and + + + align:start position:0% +and it's just using recursion and +memorization together + + align:start position:0% +memorization together + + + align:start position:0% +memorization together +okay so now let's apply that technique + + align:start position:0% +okay so now let's apply that technique + + + align:start position:0% +okay so now let's apply that technique +to think about the dag shortest paths + + align:start position:0% +to think about the dag shortest paths + + + align:start position:0% +to think about the dag shortest paths +problem the problem was i give you a dag + + align:start position:0% +problem the problem was i give you a dag + + + align:start position:0% +problem the problem was i give you a dag +i give you a source vertex + + align:start position:0% +i give you a source vertex + + + align:start position:0% +i give you a source vertex +s single source shortest paths compute + + align:start position:0% +s single source shortest paths compute + + + align:start position:0% +s single source shortest paths compute +the shortest path weight + + align:start position:0% +the shortest path weight + + + align:start position:0% +the shortest path weight +from s to every vertex that's the goal + + align:start position:0% +from s to every vertex that's the goal + + + align:start position:0% +from s to every vertex that's the goal +of the problem + + align:start position:0% +of the problem + + + align:start position:0% +of the problem +and we saw a way to solve that which is + + align:start position:0% +and we saw a way to solve that which is + + + align:start position:0% +and we saw a way to solve that which is +dag relaxation i'm going to show you a + + align:start position:0% +dag relaxation i'm going to show you a + + + align:start position:0% +dag relaxation i'm going to show you a +different + + align:start position:0% +different + + + align:start position:0% +different +way which turns out to be basically the + + align:start position:0% +way which turns out to be basically the + + + align:start position:0% +way which turns out to be basically the +same but upside down + + align:start position:0% +same but upside down + + + align:start position:0% +same but upside down +or flipped left to right depending which + + align:start position:0% +or flipped left to right depending which + + + align:start position:0% +or flipped left to right depending which +way you + + align:start position:0% +way you + + + align:start position:0% +way you +direct your edges so + + align:start position:0% +direct your edges so + + + align:start position:0% +direct your edges so +what are our sub problems well here + + align:start position:0% +what are our sub problems well here + + + align:start position:0% +what are our sub problems well here +actually they're kind of spelled out for + + align:start position:0% +actually they're kind of spelled out for + + + align:start position:0% +actually they're kind of spelled out for +us we want to compute delta of sv for + + align:start position:0% +us we want to compute delta of sv for + + + align:start position:0% +us we want to compute delta of sv for +all v + + align:start position:0% +all v + + + align:start position:0% +all v +so that is uh size of these sub-problems + + align:start position:0% +so that is uh size of these sub-problems + + + align:start position:0% +so that is uh size of these sub-problems +that turns out to be enough for this + + align:start position:0% +that turns out to be enough for this + + + align:start position:0% +that turns out to be enough for this +overall problem and the original problem + + align:start position:0% +overall problem and the original problem + + + align:start position:0% +overall problem and the original problem +we want to solve + + align:start position:0% +we want to solve + + + align:start position:0% +we want to solve +is all of the sub problems we solve all + + align:start position:0% +is all of the sub problems we solve all + + + align:start position:0% +is all of the sub problems we solve all +the sub problems we're done + + align:start position:0% +the sub problems we're done + + + align:start position:0% +the sub problems we're done +and then we have uh i think we wrote + + align:start position:0% +and then we have uh i think we wrote + + + align:start position:0% +and then we have uh i think we wrote +this at some point during + + align:start position:0% +this at some point during + + + align:start position:0% +this at some point during +the dag shortest paths lecture we have a + + align:start position:0% +the dag shortest paths lecture we have a + + + align:start position:0% +the dag shortest paths lecture we have a +recursive relation saying that + + align:start position:0% +recursive relation saying that + + + align:start position:0% +recursive relation saying that +the the shortest way to get from s to v + + align:start position:0% +the the shortest way to get from s to v + + + align:start position:0% +the the shortest way to get from s to v +is the minimum + + align:start position:0% +is the minimum + + + align:start position:0% +is the minimum +of the shortest path to get to some + + align:start position:0% +of the shortest path to get to some + + + align:start position:0% +of the shortest path to get to some +vertex u + + align:start position:0% +vertex u + + + align:start position:0% +vertex u +plus the weight of the edge from u to v + + align:start position:0% +plus the weight of the edge from u to v + + + align:start position:0% +plus the weight of the edge from u to v +why because if we look at a vertex v + + align:start position:0% +why because if we look at a vertex v + + + align:start position:0% +why because if we look at a vertex v +unless we started there we came from + + align:start position:0% +unless we started there we came from + + + align:start position:0% +unless we started there we came from +somewhere + + align:start position:0% +somewhere + + + align:start position:0% +somewhere +and so we can consider all of the + + align:start position:0% +and so we can consider all of the + + + align:start position:0% +and so we can consider all of the +possible + + align:start position:0% +possible + + + align:start position:0% +possible +choices for the previous vertex u and + + align:start position:0% +choices for the previous vertex u and + + + align:start position:0% +choices for the previous vertex u and +if you start at s and get to v you must + + align:start position:0% +if you start at s and get to v you must + + + align:start position:0% +if you start at s and get to v you must +go through one of them + + align:start position:0% +go through one of them + + + align:start position:0% +go through one of them +and so this is finding the best way + + align:start position:0% +and so this is finding the best way + + + align:start position:0% +and so this is finding the best way +among all the choices of you + + align:start position:0% +among all the choices of you + + + align:start position:0% +among all the choices of you +uh what's the best way to get to you and + + align:start position:0% +uh what's the best way to get to you and + + + align:start position:0% +uh what's the best way to get to you and +then take the edge from u to v + + align:start position:0% +then take the edge from u to v + + + align:start position:0% +then take the edge from u to v +for all edges uv and this is adjacency + + align:start position:0% +for all edges uv and this is adjacency + + + align:start position:0% +for all edges uv and this is adjacency +minus we don't usually think of that + + align:start position:0% +minus we don't usually think of that + + + align:start position:0% +minus we don't usually think of that +usually we look at adjacency plus the + + align:start position:0% +usually we look at adjacency plus the + + + align:start position:0% +usually we look at adjacency plus the +outgoing edges this is the incoming + + align:start position:0% +outgoing edges this is the incoming + + + align:start position:0% +outgoing edges this is the incoming +edges + + align:start position:0% +edges + + + align:start position:0% +edges +and so u is an incoming uv is an + + align:start position:0% +and so u is an incoming uv is an + + + align:start position:0% +and so u is an incoming uv is an +incoming edge into v + + align:start position:0% +incoming edge into v + + + align:start position:0% +incoming edge into v +okay if we take that minimum and of + + align:start position:0% +okay if we take that minimum and of + + + align:start position:0% +okay if we take that minimum and of +course the possible there + + align:start position:0% +course the possible there + + + align:start position:0% +course the possible there +there is no way to get to v and so i'll + + align:start position:0% +there is no way to get to v and so i'll + + + align:start position:0% +there is no way to get to v and so i'll +also throw infinity into this set + + align:start position:0% +also throw infinity into this set + + + align:start position:0% +also throw infinity into this set +take the min of that set that will give + + align:start position:0% +take the min of that set that will give + + + align:start position:0% +take the min of that set that will give +me the shortest path weight + + align:start position:0% +me the shortest path weight + + + align:start position:0% +me the shortest path weight +in an acyclic graph from s to v and + + align:start position:0% +in an acyclic graph from s to v and + + + align:start position:0% +in an acyclic graph from s to v and +great this is recursive right this was a + + align:start position:0% +great this is recursive right this was a + + + align:start position:0% +great this is recursive right this was a +sub problem + + align:start position:0% +sub problem + + + align:start position:0% +sub problem +these are sub problems which are smaller + + align:start position:0% +these are sub problems which are smaller + + + align:start position:0% +these are sub problems which are smaller +i guess there's no clear notion of + + align:start position:0% +i guess there's no clear notion of + + + align:start position:0% +i guess there's no clear notion of +smaller here + + align:start position:0% +smaller here + + + align:start position:0% +smaller here +except we already know the clear notion + + align:start position:0% +except we already know the clear notion + + + align:start position:0% +except we already know the clear notion +of smaller is + + align:start position:0% +of smaller is + + + align:start position:0% +of smaller is +the topological order of our dag + + align:start position:0% +the topological order of our dag + + + align:start position:0% +the topological order of our dag +because our graph is acyclic we know it + + align:start position:0% +because our graph is acyclic we know it + + + align:start position:0% +because our graph is acyclic we know it +has a topological order we know how to + + align:start position:0% +has a topological order we know how to + + + align:start position:0% +has a topological order we know how to +compute it with dfs + + align:start position:0% +compute it with dfs + + + align:start position:0% +compute it with dfs +and so that guarantees uh there's a + + align:start position:0% +and so that guarantees uh there's a + + + align:start position:0% +and so that guarantees uh there's a +topological order to compute these + + align:start position:0% +topological order to compute these + + + align:start position:0% +topological order to compute these +problems + + align:start position:0% +problems + + + align:start position:0% +problems +and in fact the the relationship + + align:start position:0% +and in fact the the relationship + + + align:start position:0% +and in fact the the relationship +between problems is exactly + + align:start position:0% +between problems is exactly + + + align:start position:0% +between problems is exactly +the given graph g in order to compute + + align:start position:0% +the given graph g in order to compute + + + align:start position:0% +the given graph g in order to compute +the shortest path weight from + + align:start position:0% +the shortest path weight from + + + align:start position:0% +the shortest path weight from +s to v i need to know the shortest + + align:start position:0% +s to v i need to know the shortest + + + align:start position:0% +s to v i need to know the shortest +pathway from s to all of the incoming + + align:start position:0% +pathway from s to all of the incoming + + + align:start position:0% +pathway from s to all of the incoming +vertices + + align:start position:0% +vertices + + + align:start position:0% +vertices +to v and so this is uh i guess + + align:start position:0% +to v and so this is uh i guess + + + align:start position:0% +to v and so this is uh i guess +in the call graph this vertex calls this + + align:start position:0% +in the call graph this vertex calls this + + + align:start position:0% +in the call graph this vertex calls this +vertex + + align:start position:0% +vertex + + + align:start position:0% +vertex +but i'll direct the edge this way to say + + align:start position:0% +but i'll direct the edge this way to say + + + align:start position:0% +but i'll direct the edge this way to say +that this vertex + + align:start position:0% +that this vertex + + + align:start position:0% +that this vertex +requires uh this vertex needs to be + + align:start position:0% +requires uh this vertex needs to be + + + align:start position:0% +requires uh this vertex needs to be +computed before this one + + align:start position:0% +computed before this one + + + align:start position:0% +computed before this one +and so then i can compute them in a + + align:start position:0% +and so then i can compute them in a + + + align:start position:0% +and so then i can compute them in a +topological order + + align:start position:0% +topological order + + + align:start position:0% +topological order +okay we have a base case which is delta + + align:start position:0% +okay we have a base case which is delta + + + align:start position:0% +okay we have a base case which is delta +of ss equals zero + + align:start position:0% +of ss equals zero + + + align:start position:0% +of ss equals zero +and the running time is again we can use + + align:start position:0% +and the running time is again we can use + + + align:start position:0% +and the running time is again we can use +this formula and say let's just sum over + + align:start position:0% +this formula and say let's just sum over + + + align:start position:0% +this formula and say let's just sum over +all the sub-problems + + align:start position:0% +all the sub-problems + + + align:start position:0% +all the sub-problems +of the non-recursive work in our + + align:start position:0% +of the non-recursive work in our + + + align:start position:0% +of the non-recursive work in our +recurrence relation + + align:start position:0% +recurrence relation + + + align:start position:0% +recurrence relation +and so it's computing this min if i gave + + align:start position:0% +and so it's computing this min if i gave + + + align:start position:0% +and so it's computing this min if i gave +you + + align:start position:0% +you + + + align:start position:0% +you +these deltas for free and i gave you + + align:start position:0% +these deltas for free and i gave you + + + align:start position:0% +these deltas for free and i gave you +these weights which we know + + align:start position:0% +these weights which we know + + + align:start position:0% +these weights which we know +from our weight data structure how long + + align:start position:0% +from our weight data structure how long + + + align:start position:0% +from our weight data structure how long +does it take to compute this min well + + align:start position:0% +does it take to compute this min well + + + align:start position:0% +does it take to compute this min well +however many things there are and how + + align:start position:0% +however many things there are and how + + + align:start position:0% +however many things there are and how +many numbers were + + align:start position:0% +many numbers were + + + align:start position:0% +many numbers were +were mining which is the size of the + + align:start position:0% +were mining which is the size of the + + + align:start position:0% +were mining which is the size of the +incoming adjacency list + + align:start position:0% +incoming adjacency list + + + align:start position:0% +incoming adjacency list +plus one for that infinity and so if you + + align:start position:0% +plus one for that infinity and so if you + + + align:start position:0% +plus one for that infinity and so if you +compute this sum + + align:start position:0% +compute this sum + + + align:start position:0% +compute this sum +sum of incoming edges to every vertex + + align:start position:0% +sum of incoming edges to every vertex + + + align:start position:0% +sum of incoming edges to every vertex +that's all the edges + + align:start position:0% +that's all the edges + + + align:start position:0% +that's all the edges +so this is v plus e okay so + + align:start position:0% +so this is v plus e okay so + + + align:start position:0% +so this is v plus e okay so +in fact this algorithm is + + align:start position:0% +in fact this algorithm is + + + align:start position:0% +in fact this algorithm is +morally the same algorithm is the one + + align:start position:0% +morally the same algorithm is the one + + + align:start position:0% +morally the same algorithm is the one +that we saw in the dag shortest path + + align:start position:0% +that we saw in the dag shortest path + + + align:start position:0% +that we saw in the dag shortest path +lecture + + align:start position:0% +lecture + + + align:start position:0% +lecture +which was computer topological order + + align:start position:0% +which was computer topological order + + + align:start position:0% +which was computer topological order +and process vertices in that order + + align:start position:0% +and process vertices in that order + + + align:start position:0% +and process vertices in that order +and relax edges going out from + + align:start position:0% +and relax edges going out from + + + align:start position:0% +and relax edges going out from +vertices so here uh so in + + align:start position:0% +vertices so here uh so in + + + align:start position:0% +vertices so here uh so in +in that algorithm we would have uh tried + + align:start position:0% +in that algorithm we would have uh tried + + + align:start position:0% +in that algorithm we would have uh tried +to relax this edge + + align:start position:0% +to relax this edge + + + align:start position:0% +to relax this edge +if if there's a better path to v and the + + align:start position:0% +if if there's a better path to v and the + + + align:start position:0% +if if there's a better path to v and the +first one certainly is better than + + align:start position:0% +first one certainly is better than + + + align:start position:0% +first one certainly is better than +infinity + + align:start position:0% +infinity + + + align:start position:0% +infinity +so the first one we relax uh indeed + + align:start position:0% +so the first one we relax uh indeed + + + align:start position:0% +so the first one we relax uh indeed +uh the next edge if this is a if this + + align:start position:0% +uh the next edge if this is a if this + + + align:start position:0% +uh the next edge if this is a if this +gave a better path from s to v then we + + align:start position:0% +gave a better path from s to v then we + + + align:start position:0% +gave a better path from s to v then we +would relax that edge and update the + + align:start position:0% +would relax that edge and update the + + + align:start position:0% +would relax that edge and update the +weight here + + align:start position:0% +weight here + + + align:start position:0% +weight here +and do the same here in the end we're + + align:start position:0% +and do the same here in the end we're + + + align:start position:0% +and do the same here in the end we're +just computing this min + + align:start position:0% +just computing this min + + + align:start position:0% +just computing this min +in the relaxation algorithm but doing it + + align:start position:0% +in the relaxation algorithm but doing it + + + align:start position:0% +in the relaxation algorithm but doing it +step by step in the in the relaxation + + align:start position:0% +step by step in the in the relaxation + + + align:start position:0% +step by step in the in the relaxation +algorithm tag relaxation + + align:start position:0% +algorithm tag relaxation + + + align:start position:0% +algorithm tag relaxation +we for each incoming edge to v + + align:start position:0% +we for each incoming edge to v + + + align:start position:0% +we for each incoming edge to v +we update d of v if it's better + + align:start position:0% +we update d of v if it's better + + + align:start position:0% +we update d of v if it's better +and so if you if you repeatedly update + + align:start position:0% +and so if you if you repeatedly update + + + align:start position:0% +and so if you if you repeatedly update +if you're better that ends up computing + + align:start position:0% +if you're better that ends up computing + + + align:start position:0% +if you're better that ends up computing +a min + + align:start position:0% +a min + + + align:start position:0% +a min +okay so this is the same algorithm just + + align:start position:0% +okay so this is the same algorithm just + + + align:start position:0% +okay so this is the same algorithm just +kind of flipped backwards + + align:start position:0% +kind of flipped backwards + + + align:start position:0% +kind of flipped backwards +uh a funny thing although we wrote down + + align:start position:0% +uh a funny thing although we wrote down + + + align:start position:0% +uh a funny thing although we wrote down +the topological order + + align:start position:0% +the topological order + + + align:start position:0% +the topological order +of the subproblem graph here is the + + align:start position:0% +of the subproblem graph here is the + + + align:start position:0% +of the subproblem graph here is the +topological order of g because + + align:start position:0% +topological order of g because + + + align:start position:0% +topological order of g because +the sub-problem graph is g + + align:start position:0% + + + + align:start position:0% + +the algorithm doesn't actually have to + + align:start position:0% +the algorithm doesn't actually have to + + + align:start position:0% +the algorithm doesn't actually have to +compute one it's doing it + + align:start position:0% +compute one it's doing it + + + align:start position:0% +compute one it's doing it +automatically for free if you think + + align:start position:0% +automatically for free if you think + + + align:start position:0% +automatically for free if you think +about + + align:start position:0% +about + + + align:start position:0% +about +this algorithm a generic + + align:start position:0% +this algorithm a generic + + + align:start position:0% +this algorithm a generic +dp algorithm which is check whether + + align:start position:0% +dp algorithm which is check whether + + + align:start position:0% +dp algorithm which is check whether +we're in a memo table if so return + + align:start position:0% +we're in a memo table if so return + + + align:start position:0% +we're in a memo table if so return +otherwise recurse or base case + + align:start position:0% +otherwise recurse or base case + + + align:start position:0% +otherwise recurse or base case +this actually is a depth for search + + align:start position:0% +this actually is a depth for search + + + align:start position:0% +this actually is a depth for search +through the sub-problem graph + + align:start position:0% +through the sub-problem graph + + + align:start position:0% +through the sub-problem graph +technically through the reverse of the + + align:start position:0% +technically through the reverse of the + + + align:start position:0% +technically through the reverse of the +subproblem graph + + align:start position:0% +subproblem graph + + + align:start position:0% +subproblem graph +if i draw an edge + + align:start position:0% +if i draw an edge + + + align:start position:0% +if i draw an edge +so from small + + align:start position:0% +so from small + + + align:start position:0% +so from small +to big so + + align:start position:0% +to big so + + + align:start position:0% +to big so +if i'm just saying i orient the edges + + align:start position:0% +if i'm just saying i orient the edges + + + align:start position:0% +if i'm just saying i orient the edges +from my smaller sub problems to the ones + + align:start position:0% +from my smaller sub problems to the ones + + + align:start position:0% +from my smaller sub problems to the ones +that need it + + align:start position:0% +that need it + + + align:start position:0% +that need it +then i'm actually definitely searching + + align:start position:0% +then i'm actually definitely searching + + + align:start position:0% +then i'm actually definitely searching +backwards in this graph + + align:start position:0% +backwards in this graph + + + align:start position:0% +backwards in this graph +because the bigger problem calls the + + align:start position:0% +because the bigger problem calls the + + + align:start position:0% +because the bigger problem calls the +smaller problem + + align:start position:0% +smaller problem + + + align:start position:0% +smaller problem +and the memo table is serving as the + + align:start position:0% +and the memo table is serving as the + + + align:start position:0% +and the memo table is serving as the +have i visited this vertex + + align:start position:0% +have i visited this vertex + + + align:start position:0% +have i visited this vertex +already check in dfs so this is actually + + align:start position:0% +already check in dfs so this is actually + + + align:start position:0% +already check in dfs so this is actually +a dfs algorithm + + align:start position:0% +a dfs algorithm + + + align:start position:0% +a dfs algorithm +plus we're doing some computation + + align:start position:0% +plus we're doing some computation + + + align:start position:0% +plus we're doing some computation +to actually solve the sub problems we + + align:start position:0% +to actually solve the sub problems we + + + align:start position:0% +to actually solve the sub problems we +care about + + align:start position:0% +care about + + + align:start position:0% +care about +so implicit in this algorithm we are + + align:start position:0% +so implicit in this algorithm we are + + + align:start position:0% +so implicit in this algorithm we are +doing a dfs and at + + align:start position:0% +doing a dfs and at + + + align:start position:0% +doing a dfs and at +the same time we're doing this shortest + + align:start position:0% +the same time we're doing this shortest + + + align:start position:0% +the same time we're doing this shortest +path computation + + align:start position:0% +path computation + + + align:start position:0% +path computation +uh in the finishing order of that dfs + + align:start position:0% +uh in the finishing order of that dfs + + + align:start position:0% +uh in the finishing order of that dfs +traversal + + align:start position:0% +traversal + + + align:start position:0% +traversal +because all the edges are backwards this + + align:start position:0% +because all the edges are backwards this + + + align:start position:0% +because all the edges are backwards this +is the same as the reverse finishing + + align:start position:0% +is the same as the reverse finishing + + + align:start position:0% +is the same as the reverse finishing +order if the graph is forwards so in the + + align:start position:0% +order if the graph is forwards so in the + + + align:start position:0% +order if the graph is forwards so in the +end + + align:start position:0% +end + + + align:start position:0% +end +we're computing a topological order + + align:start position:0% +we're computing a topological order + + + align:start position:0% +we're computing a topological order +because + + align:start position:0% +because + + + align:start position:0% +because +uh dynamic programming includes in it + + align:start position:0% +uh dynamic programming includes in it + + + align:start position:0% +uh dynamic programming includes in it +uh depth first search oh a lot of words + + align:start position:0% +uh depth first search oh a lot of words + + + align:start position:0% +uh depth first search oh a lot of words +but it's kind of cool that this + + align:start position:0% +but it's kind of cool that this + + + align:start position:0% +but it's kind of cool that this +framework just solves dag shortest paths + + align:start position:0% +framework just solves dag shortest paths + + + align:start position:0% +framework just solves dag shortest paths +without + + align:start position:0% +without + + + align:start position:0% +without +much work i mean we we did a lot of work + + align:start position:0% +much work i mean we we did a lot of work + + + align:start position:0% +much work i mean we we did a lot of work +in shorts paths to prove that this + + align:start position:0% +in shorts paths to prove that this + + + align:start position:0% +in shorts paths to prove that this +relation is true + + align:start position:0% +relation is true + + + align:start position:0% +relation is true +but once you know it's true the + + align:start position:0% +but once you know it's true the + + + align:start position:0% +but once you know it's true the +algorithm part is + + align:start position:0% +algorithm part is + + + align:start position:0% +algorithm part is +is pretty much free you just write down + + align:start position:0% +is pretty much free you just write down + + + align:start position:0% +is pretty much free you just write down +sort bot and you're done + + align:start position:0% + + + + align:start position:0% + +okay this brings us to + + align:start position:0% +okay this brings us to + + + align:start position:0% +okay this brings us to +in general at this point we have seen + + align:start position:0% +in general at this point we have seen + + + align:start position:0% +in general at this point we have seen +two + + align:start position:0% +two + + + align:start position:0% +two +examples of dynamic programming i guess + + align:start position:0% +examples of dynamic programming i guess + + + align:start position:0% +examples of dynamic programming i guess +technically merge sort + + align:start position:0% +technically merge sort + + + align:start position:0% +technically merge sort +you can think of as a dynamic program + + align:start position:0% +you can think of as a dynamic program + + + align:start position:0% +you can think of as a dynamic program +but it doesn't actually reuse anything + + align:start position:0% +but it doesn't actually reuse anything + + + align:start position:0% +but it doesn't actually reuse anything +so it's not interesting + + align:start position:0% +so it's not interesting + + + align:start position:0% +so it's not interesting +and indeed that gave us a really bad + + align:start position:0% +and indeed that gave us a really bad + + + align:start position:0% +and indeed that gave us a really bad +bound we've definitely seen bag shortest + + align:start position:0% +bound we've definitely seen bag shortest + + + align:start position:0% +bound we've definitely seen bag shortest +paths + + align:start position:0% +paths + + + align:start position:0% +paths +and fibonacci numbers as two interesting + + align:start position:0% +and fibonacci numbers as two interesting + + + align:start position:0% +and fibonacci numbers as two interesting +examples + + align:start position:0% +examples + + + align:start position:0% +examples +and what the next remainder of this + + align:start position:0% +and what the next remainder of this + + + align:start position:0% +and what the next remainder of this +lecture and the next three lectures are + + align:start position:0% +lecture and the next three lectures are + + + align:start position:0% +lecture and the next three lectures are +going to be about + + align:start position:0% +going to be about + + + align:start position:0% +going to be about +is more and more examples of dynamic + + align:start position:0% +is more and more examples of dynamic + + + align:start position:0% +is more and more examples of dynamic +programming and how you can use it to + + align:start position:0% +programming and how you can use it to + + + align:start position:0% +programming and how you can use it to +solve + + align:start position:0% +solve + + + align:start position:0% +solve +increasingly general problems so far + + align:start position:0% +increasingly general problems so far + + + align:start position:0% +increasingly general problems so far +we've just solved an easy problem + + align:start position:0% +we've just solved an easy problem + + + align:start position:0% +we've just solved an easy problem +and a problem we already knew how to + + align:start position:0% +and a problem we already knew how to + + + align:start position:0% +and a problem we already knew how to +solve let's go to a new problem + + align:start position:0% + + + + align:start position:0% + +which is bowling bowling is popular in + + align:start position:0% +which is bowling bowling is popular in + + + align:start position:0% +which is bowling bowling is popular in +boston + + align:start position:0% +boston + + + align:start position:0% +boston +this boston likes to play candlepin + + align:start position:0% +this boston likes to play candlepin + + + align:start position:0% +this boston likes to play candlepin +bowling which is a bit unusual + + align:start position:0% +bowling which is a bit unusual + + + align:start position:0% +bowling which is a bit unusual +uh today we're going to play an even + + align:start position:0% +uh today we're going to play an even + + + align:start position:0% +uh today we're going to play an even +more unusual bowling game + + align:start position:0% +more unusual bowling game + + + align:start position:0% +more unusual bowling game +one that i made up based on a bowling + + align:start position:0% +one that i made up based on a bowling + + + align:start position:0% +one that i made up based on a bowling +game + + align:start position:0% +game + + + align:start position:0% +game +that henry dudeny made up in 1908 + + align:start position:0% +that henry dudeny made up in 1908 + + + align:start position:0% +that henry dudeny made up in 1908 +so ancient bowling i might call it + + align:start position:0% +so ancient bowling i might call it + + + align:start position:0% +so ancient bowling i might call it +or i think linear bowling is what i + + align:start position:0% +or i think linear bowling is what i + + + align:start position:0% +or i think linear bowling is what i +might call it i'll just call it bowling + + align:start position:0% +might call it i'll just call it bowling + + + align:start position:0% +might call it i'll just call it bowling +here + + align:start position:0% +here + + + align:start position:0% +here +and now i'm going to attempt to draw a + + align:start position:0% +and now i'm going to attempt to draw a + + + align:start position:0% +and now i'm going to attempt to draw a +bowling pin not bad + + align:start position:0% +bowling pin not bad + + + align:start position:0% +bowling pin not bad +that might get progressively worse so + + align:start position:0% +that might get progressively worse so + + + align:start position:0% +that might get progressively worse so +imagine + + align:start position:0% +imagine + + + align:start position:0% +imagine +n identical bowling pins please pretend + + align:start position:0% +n identical bowling pins please pretend + + + align:start position:0% +n identical bowling pins please pretend +these are identical + + align:start position:0% +these are identical + + + align:start position:0% +these are identical +and i have a ball which is + + align:start position:0% +and i have a ball which is + + + align:start position:0% +and i have a ball which is +approximately the same size as a bowling + + align:start position:0% +approximately the same size as a bowling + + + align:start position:0% +approximately the same size as a bowling +pin these bowling pins are + + align:start position:0% +pin these bowling pins are + + + align:start position:0% +pin these bowling pins are +pretty close together i should have left + + align:start position:0% +pretty close together i should have left + + + align:start position:0% +pretty close together i should have left +a little gap here + + align:start position:0% +a little gap here + + + align:start position:0% +a little gap here +and you're a really good bowler now + + align:start position:0% +and you're a really good bowler now + + + align:start position:0% +and you're a really good bowler now +unfortunately these bowling + + align:start position:0% +unfortunately these bowling + + + align:start position:0% +unfortunately these bowling +pins are on a line and you're bowling + + align:start position:0% +pins are on a line and you're bowling + + + align:start position:0% +pins are on a line and you're bowling +from + + align:start position:0% +from + + + align:start position:0% +from +way down at infinity so when you bowl + + align:start position:0% +way down at infinity so when you bowl + + + align:start position:0% +way down at infinity so when you bowl +um you can only hit one pin or two pins + + align:start position:0% +um you can only hit one pin or two pins + + + align:start position:0% +um you can only hit one pin or two pins +or + + align:start position:0% +or + + + align:start position:0% +or +zero pins but probably you want to hit + + align:start position:0% +zero pins but probably you want to hit + + + align:start position:0% +zero pins but probably you want to hit +some pins uh so if you + + align:start position:0% +some pins uh so if you + + + align:start position:0% +some pins uh so if you +pull straight at a pin you will just hit + + align:start position:0% +pull straight at a pin you will just hit + + + align:start position:0% +pull straight at a pin you will just hit +that one pin + + align:start position:0% +that one pin + + + align:start position:0% +that one pin +and if you bowl in the middle between + + align:start position:0% +and if you bowl in the middle between + + + align:start position:0% +and if you bowl in the middle between +two pins + + align:start position:0% +two pins + + + align:start position:0% +two pins +you will knock down that's a ball sorry + + align:start position:0% +you will knock down that's a ball sorry + + + align:start position:0% +you will knock down that's a ball sorry +you will knock down + + align:start position:0% +you will knock down + + + align:start position:0% +you will knock down +two pins okay this is your model of + + align:start position:0% +two pins okay this is your model of + + + align:start position:0% +two pins okay this is your model of +bowling + + align:start position:0% +bowling + + + align:start position:0% +bowling +model of computation now what makes this + + align:start position:0% +model of computation now what makes this + + + align:start position:0% +model of computation now what makes this +interesting is that the pins have values + + align:start position:0% +interesting is that the pins have values + + + align:start position:0% +interesting is that the pins have values +pin i has value + + align:start position:0% +pin i has value + + + align:start position:0% +pin i has value +yeah this is obviously a toy problem uh + + align:start position:0% +yeah this is obviously a toy problem uh + + + align:start position:0% +yeah this is obviously a toy problem uh +though this problem this type of bowling + + align:start position:0% +though this problem this type of bowling + + + align:start position:0% +though this problem this type of bowling +does go back to 1908 + + align:start position:0% +does go back to 1908 + + + align:start position:0% +does go back to 1908 +it was also a toy problem in that + + align:start position:0% +it was also a toy problem in that + + + align:start position:0% +it was also a toy problem in that +setting so each of these + + align:start position:0% +setting so each of these + + + align:start position:0% +setting so each of these +uh bowling pins has some number on it + + align:start position:0% +uh bowling pins has some number on it + + + align:start position:0% +uh bowling pins has some number on it +let's say one nine nine + + align:start position:0% +let's say one nine nine + + + align:start position:0% +let's say one nine nine +let me do a slightly more interesting + + align:start position:0% +let me do a slightly more interesting + + + align:start position:0% +let me do a slightly more interesting +example maybe another one here + + align:start position:0% +example maybe another one here + + + align:start position:0% +example maybe another one here +uh and a two + + align:start position:0% +uh and a two + + + align:start position:0% +uh and a two +and a five and a five something like + + align:start position:0% +and a five and a five something like + + + align:start position:0% +and a five and a five something like +this + + align:start position:0% +this + + + align:start position:0% +this +okay uh or maybe make a little more + + align:start position:0% +okay uh or maybe make a little more + + + align:start position:0% +okay uh or maybe make a little more +interesting let's put some negative + + align:start position:0% +interesting let's put some negative + + + align:start position:0% +interesting let's put some negative +numbers on here + + align:start position:0% +numbers on here + + + align:start position:0% +numbers on here +okay and the model uh so you're at the + + align:start position:0% +okay and the model uh so you're at the + + + align:start position:0% +okay and the model uh so you're at the +carnival bowling + + align:start position:0% +carnival bowling + + + align:start position:0% +carnival bowling +each pin has different potentially + + align:start position:0% +each pin has different potentially + + + align:start position:0% +each pin has different potentially +different values + + align:start position:0% +different values + + + align:start position:0% +different values +and the model is if you hit + + align:start position:0% +and the model is if you hit + + + align:start position:0% +and the model is if you hit +one pin i + + align:start position:0% +one pin i + + + align:start position:0% +one pin i +then you get vi points + + align:start position:0% +then you get vi points + + + align:start position:0% +then you get vi points +so that's straightforward to make it + + align:start position:0% +so that's straightforward to make it + + + align:start position:0% +so that's straightforward to make it +interesting + + align:start position:0% +interesting + + + align:start position:0% +interesting +when you hit two pins you get the + + align:start position:0% +when you hit two pins you get the + + + align:start position:0% +when you hit two pins you get the +product + + align:start position:0% +product + + + align:start position:0% +product +so if i hit two pins it's always i and i + + align:start position:0% +so if i hit two pins it's always i and i + + + align:start position:0% +so if i hit two pins it's always i and i +plus one + + align:start position:0% +plus one + + + align:start position:0% +plus one +for some i you get vi times vi plus one + + align:start position:0% + + + + align:start position:0% + +points this is the + + align:start position:0% +points this is the + + + align:start position:0% +points this is the +the game you're playing and it doesn't + + align:start position:0% +the game you're playing and it doesn't + + + align:start position:0% +the game you're playing and it doesn't +really matter that this is a product + + align:start position:0% +really matter that this is a product + + + align:start position:0% +really matter that this is a product +uh product is just some weird function + + align:start position:0% +uh product is just some weird function + + + align:start position:0% +uh product is just some weird function +that's hard to + + align:start position:0% +that's hard to + + + align:start position:0% +that's hard to +imagine if you stare at this long enough + + align:start position:0% +imagine if you stare at this long enough + + + align:start position:0% +imagine if you stare at this long enough +you should convince yourself that the + + align:start position:0% +you should convince yourself that the + + + align:start position:0% +you should convince yourself that the +optimal solution is probably to + + align:start position:0% +optimal solution is probably to + + + align:start position:0% +optimal solution is probably to +so for each of these numbers i could + + align:start position:0% +so for each of these numbers i could + + + align:start position:0% +so for each of these numbers i could +leave it singleton or pair it with its + + align:start position:0% +leave it singleton or pair it with its + + + align:start position:0% +leave it singleton or pair it with its +left neighbor or pair it with its right + + align:start position:0% +left neighbor or pair it with its right + + + align:start position:0% +left neighbor or pair it with its right +neighbor but the pairings can't overlap + + align:start position:0% +neighbor but the pairings can't overlap + + + align:start position:0% +neighbor but the pairings can't overlap +because once i hit a pin + + align:start position:0% +because once i hit a pin + + + align:start position:0% +because once i hit a pin +it's gone it's knocked over and it + + align:start position:0% +it's gone it's knocked over and it + + + align:start position:0% +it's gone it's knocked over and it +disappears + + align:start position:0% +disappears + + + align:start position:0% +disappears +so because of these nines which are very + + align:start position:0% +so because of these nines which are very + + + align:start position:0% +so because of these nines which are very +high + + align:start position:0% +high + + + align:start position:0% +high +value what i'd probably like to do is + + align:start position:0% +value what i'd probably like to do is + + + align:start position:0% +value what i'd probably like to do is +hit both of them together so pair them + + align:start position:0% +hit both of them together so pair them + + + align:start position:0% +hit both of them together so pair them +up + + align:start position:0% +up + + + align:start position:0% +up +because 9 times 9 is 81 that's really + + align:start position:0% +because 9 times 9 is 81 that's really + + + align:start position:0% +because 9 times 9 is 81 that's really +big much better than hitting them + + align:start position:0% +big much better than hitting them + + + align:start position:0% +big much better than hitting them +individually or hitting 9 times 1 or 9 + + align:start position:0% +individually or hitting 9 times 1 or 9 + + + align:start position:0% +individually or hitting 9 times 1 or 9 +times 2. + + align:start position:0% +times 2. + + + align:start position:0% +times 2. +one and one is kind of funny because + + align:start position:0% +one and one is kind of funny because + + + align:start position:0% +one and one is kind of funny because +it's actually better to hit them + + align:start position:0% +it's actually better to hit them + + + align:start position:0% +it's actually better to hit them +individually + + align:start position:0% +individually + + + align:start position:0% +individually +that will give you two points whereas if + + align:start position:0% +that will give you two points whereas if + + + align:start position:0% +that will give you two points whereas if +i pair them up i only get one point + + align:start position:0% +i pair them up i only get one point + + + align:start position:0% +i pair them up i only get one point +two and minus five that seems bad + + align:start position:0% +two and minus five that seems bad + + + align:start position:0% +two and minus five that seems bad +negative ten points my goal is to + + align:start position:0% +negative ten points my goal is to + + + align:start position:0% +negative ten points my goal is to +maximize score + + align:start position:0% + + + + align:start position:0% + +do you have to hit all the pins + + align:start position:0% + + + + align:start position:0% + +let's say no you don't have to hit all + + align:start position:0% +let's say no you don't have to hit all + + + align:start position:0% +let's say no you don't have to hit all +the pins so i could skip the minus fives + + align:start position:0% +the pins so i could skip the minus fives + + + align:start position:0% +the pins so i could skip the minus fives +but in fact here uh because they're + + align:start position:0% +but in fact here uh because they're + + + align:start position:0% +but in fact here uh because they're +adjacent minus five times minus five is + + align:start position:0% +adjacent minus five times minus five is + + + align:start position:0% +adjacent minus five times minus five is +good that's 25 points + + align:start position:0% +good that's 25 points + + + align:start position:0% +good that's 25 points +so uh the optimal solution for this + + align:start position:0% +so uh the optimal solution for this + + + align:start position:0% +so uh the optimal solution for this +particular instance + + align:start position:0% +particular instance + + + align:start position:0% +particular instance +are to hit all the pins these positive + + align:start position:0% +are to hit all the pins these positive + + + align:start position:0% +are to hit all the pins these positive +uh + + align:start position:0% +uh + + + align:start position:0% +uh +these together these together if i added + + align:start position:0% +these together these together if i added + + + align:start position:0% +these together these together if i added +for example another pin of minus three + + align:start position:0% +for example another pin of minus three + + + align:start position:0% +for example another pin of minus three +here + + align:start position:0% +here + + + align:start position:0% +here +i would choose not to hit that pin good + + align:start position:0% +i would choose not to hit that pin good + + + align:start position:0% +i would choose not to hit that pin good +question so + + align:start position:0% +question so + + + align:start position:0% +question so +you just play until you are tired when + + align:start position:0% +you just play until you are tired when + + + align:start position:0% +you just play until you are tired when +you decide to stop playing + + align:start position:0% +you decide to stop playing + + + align:start position:0% +you decide to stop playing +how can i maximize your score there are + + align:start position:0% +how can i maximize your score there are + + + align:start position:0% +how can i maximize your score there are +many variations this game + + align:start position:0% +many variations this game + + + align:start position:0% +many variations this game +all of them basically any variation + + align:start position:0% +all of them basically any variation + + + align:start position:0% +all of them basically any variation +not literally every variation but many + + align:start position:0% +not literally every variation but many + + + align:start position:0% +not literally every variation but many +many variations of this problem can all + + align:start position:0% +many variations of this problem can all + + + align:start position:0% +many variations of this problem can all +be solved + + align:start position:0% +be solved + + + align:start position:0% +be solved +quickly with dynamic programming but + + align:start position:0% +quickly with dynamic programming but + + + align:start position:0% +quickly with dynamic programming but +let's solve this particular one + + align:start position:0% +let's solve this particular one + + + align:start position:0% +let's solve this particular one +okay um + + align:start position:0% + + + + align:start position:0% + +so now we're really in algorithmic + + align:start position:0% +so now we're really in algorithmic + + + align:start position:0% +so now we're really in algorithmic +design mode + + align:start position:0% +design mode + + + align:start position:0% +design mode +we need to think about sort bot + + align:start position:0% +we need to think about sort bot + + + align:start position:0% +we need to think about sort bot +and in particular we need to think about + + align:start position:0% +and in particular we need to think about + + + align:start position:0% +and in particular we need to think about +what would the subproblems be + + align:start position:0% +what would the subproblems be + + + align:start position:0% +what would the subproblems be +here and at this point we don't have a + + align:start position:0% +here and at this point we don't have a + + + align:start position:0% +here and at this point we don't have a +lot of of help so i should probably give + + align:start position:0% +lot of of help so i should probably give + + + align:start position:0% +lot of of help so i should probably give +you some tools + + align:start position:0% +you some tools + + + align:start position:0% +you some tools +if i want to solve a problem like this + + align:start position:0% +if i want to solve a problem like this + + + align:start position:0% +if i want to solve a problem like this +the input + + align:start position:0% +the input + + + align:start position:0% +the input +is a sequence of numbers right it's a + + align:start position:0% +is a sequence of numbers right it's a + + + align:start position:0% +is a sequence of numbers right it's a +sequence + + align:start position:0% +sequence + + + align:start position:0% +sequence +data structure maybe it's an array of + + align:start position:0% +data structure maybe it's an array of + + + align:start position:0% +data structure maybe it's an array of +numbers which is this v + + align:start position:0% +numbers which is this v + + + align:start position:0% +numbers which is this v +v array + + align:start position:0% + + + + align:start position:0% + +and let's see + + align:start position:0% +and let's see + + + align:start position:0% +and let's see +um a general tool for subproblem design + + align:start position:0% + + + + align:start position:0% + +which will cover most of the problems + + align:start position:0% +which will cover most of the problems + + + align:start position:0% +which will cover most of the problems +maybe all of the problems that we + + align:start position:0% +maybe all of the problems that we + + + align:start position:0% +maybe all of the problems that we +see in this class for dynamic + + align:start position:0% +see in this class for dynamic + + + align:start position:0% +see in this class for dynamic +programming + + align:start position:0% +programming + + + align:start position:0% +programming +here's a trick if + + align:start position:0% +here's a trick if + + + align:start position:0% +here's a trick if +your + + align:start position:0% + + + + align:start position:0% + +input is a sequence + + align:start position:0% + + + + align:start position:0% + +here's some good sub problems to + + align:start position:0% + + + + align:start position:0% + +consider + + align:start position:0% +consider + + + align:start position:0% +consider +uh we could do all prefixes + + align:start position:0% + + + + align:start position:0% + +so let's call the sequence x + + align:start position:0% +so let's call the sequence x + + + align:start position:0% +so let's call the sequence x +so we could do x prefix means up to a + + align:start position:0% +so we could do x prefix means up to a + + + align:start position:0% +so we could do x prefix means up to a +given i for all i + + align:start position:0% +given i for all i + + + align:start position:0% +given i for all i +we could do all the suffixes + + align:start position:0% + + + + align:start position:0% + +x from i onward for all i + + align:start position:0% +x from i onward for all i + + + align:start position:0% +x from i onward for all i +or we could do substrings + + align:start position:0% + + + + align:start position:0% + +which are the consecutive items from i + + align:start position:0% +which are the consecutive items from i + + + align:start position:0% +which are the consecutive items from i +to j + + align:start position:0% +to j + + + align:start position:0% +to j +i don't write subsequence here + + align:start position:0% +i don't write subsequence here + + + align:start position:0% +i don't write subsequence here +subsequence means you can emit items in + + align:start position:0% +subsequence means you can emit items in + + + align:start position:0% +subsequence means you can emit items in +the middle + + align:start position:0% +the middle + + + align:start position:0% +the middle +so substring you have to start at some + + align:start position:0% +so substring you have to start at some + + + align:start position:0% +so substring you have to start at some +position and do all the things up to j + + align:start position:0% +position and do all the things up to j + + + align:start position:0% +position and do all the things up to j +uh so these are nice easy to express in + + align:start position:0% +uh so these are nice easy to express in + + + align:start position:0% +uh so these are nice easy to express in +python notation + + align:start position:0% +python notation + + + align:start position:0% +python notation +and these are great because they're + + align:start position:0% +and these are great because they're + + + align:start position:0% +and these are great because they're +polynomial right if i have n + + align:start position:0% +polynomial right if i have n + + + align:start position:0% +polynomial right if i have n +things if the length of my sequence x is + + align:start position:0% +things if the length of my sequence x is + + + align:start position:0% +things if the length of my sequence x is +n + + align:start position:0% +n + + + align:start position:0% +n +then there are n sequences n prefixes + + align:start position:0% +then there are n sequences n prefixes + + + align:start position:0% +then there are n sequences n prefixes +technically n plus one so + + align:start position:0% +technically n plus one so + + + align:start position:0% +technically n plus one so +let's do theta n prefixes they're theta + + align:start position:0% +let's do theta n prefixes they're theta + + + align:start position:0% +let's do theta n prefixes they're theta +and suffixes + + align:start position:0% +and suffixes + + + align:start position:0% +and suffixes +and they're theta and squared + + align:start position:0% +and they're theta and squared + + + align:start position:0% +and they're theta and squared +substrings because there's n roughly n + + align:start position:0% +substrings because there's n roughly n + + + align:start position:0% +substrings because there's n roughly n +choices for i and j + + align:start position:0% +choices for i and j + + + align:start position:0% +choices for i and j +separately sorry + + align:start position:0% +separately sorry + + + align:start position:0% +separately sorry +subsequences good right i didn't write + + align:start position:0% +subsequences good right i didn't write + + + align:start position:0% +subsequences good right i didn't write +subsequences because in fact there are + + align:start position:0% +subsequences because in fact there are + + + align:start position:0% +subsequences because in fact there are +exponentially many subsequences right + + align:start position:0% +exponentially many subsequences right + + + align:start position:0% +exponentially many subsequences right +it's 2 to the n + + align:start position:0% +it's 2 to the n + + + align:start position:0% +it's 2 to the n +for every item i could choose it or not + + align:start position:0% +for every item i could choose it or not + + + align:start position:0% +for every item i could choose it or not +so i don't want to parametrize i don't + + align:start position:0% +so i don't want to parametrize i don't + + + align:start position:0% +so i don't want to parametrize i don't +want my sub problems to be sub sequences + + align:start position:0% +want my sub problems to be sub sequences + + + align:start position:0% +want my sub problems to be sub sequences +because that's + + align:start position:0% +because that's + + + align:start position:0% +because that's +guaranteed well then you're guaranteed + + align:start position:0% +guaranteed well then you're guaranteed + + + align:start position:0% +guaranteed well then you're guaranteed +to get an exponential number of + + align:start position:0% +to get an exponential number of + + + align:start position:0% +to get an exponential number of +sub-problems which is bad + + align:start position:0% +sub-problems which is bad + + + align:start position:0% +sub-problems which is bad +we'd like to bound the number of + + align:start position:0% +we'd like to bound the number of + + + align:start position:0% +we'd like to bound the number of +sub-problems by a polynomial + + align:start position:0% +sub-problems by a polynomial + + + align:start position:0% +sub-problems by a polynomial +so these are three natural ways to get + + align:start position:0% +so these are three natural ways to get + + + align:start position:0% +so these are three natural ways to get +uh polynomial bounds + + align:start position:0% +uh polynomial bounds + + + align:start position:0% +uh polynomial bounds +now prefixes and suffixes are obviously + + align:start position:0% +now prefixes and suffixes are obviously + + + align:start position:0% +now prefixes and suffixes are obviously +better because there's fewer of them + + align:start position:0% +better because there's fewer of them + + + align:start position:0% +better because there's fewer of them +linear instead of quadratic and usually + + align:start position:0% +linear instead of quadratic and usually + + + align:start position:0% +linear instead of quadratic and usually +almost every problem you'll encounter + + align:start position:0% +almost every problem you'll encounter + + + align:start position:0% +almost every problem you'll encounter +prefixes and suffixes are equally good + + align:start position:0% +prefixes and suffixes are equally good + + + align:start position:0% +prefixes and suffixes are equally good +it doesn't really matter which one you + + align:start position:0% +it doesn't really matter which one you + + + align:start position:0% +it doesn't really matter which one you +choose + + align:start position:0% +choose + + + align:start position:0% +choose +so maybe you like to think of well we'll + + align:start position:0% +so maybe you like to think of well we'll + + + align:start position:0% +so maybe you like to think of well we'll +get to + + align:start position:0% + + + + align:start position:0% + +it's you just choose whichever is more + + align:start position:0% +it's you just choose whichever is more + + + align:start position:0% +it's you just choose whichever is more +comfortable for you + + align:start position:0% + + + + align:start position:0% + +but sometimes it's not enough and we'll + + align:start position:0% +but sometimes it's not enough and we'll + + + align:start position:0% +but sometimes it's not enough and we'll +have to go to substrings that won't be + + align:start position:0% +have to go to substrings that won't be + + + align:start position:0% +have to go to substrings that won't be +for another lecture or two + + align:start position:0% +for another lecture or two + + + align:start position:0% +for another lecture or two +okay today i claim that prefixes or + + align:start position:0% +okay today i claim that prefixes or + + + align:start position:0% +okay today i claim that prefixes or +suffixes + + align:start position:0% +suffixes + + + align:start position:0% +suffixes +are uh enough to solve the bowling + + align:start position:0% +are uh enough to solve the bowling + + + align:start position:0% +are uh enough to solve the bowling +problem + + align:start position:0% +problem + + + align:start position:0% +problem +so what we're going to do is think about + + align:start position:0% +so what we're going to do is think about + + + align:start position:0% +so what we're going to do is think about +i prefer suffixes usually + + align:start position:0% +i prefer suffixes usually + + + align:start position:0% +i prefer suffixes usually +because i like to work from left to + + align:start position:0% +because i like to work from left to + + + align:start position:0% +because i like to work from left to +right from the beginning to the end + + align:start position:0% +right from the beginning to the end + + + align:start position:0% +right from the beginning to the end +so we're going to think of a suffix of + + align:start position:0% +so we're going to think of a suffix of + + + align:start position:0% +so we're going to think of a suffix of +the bowling pins + + align:start position:0% +the bowling pins + + + align:start position:0% +the bowling pins +and so what is the sub problem on a + + align:start position:0% +and so what is the sub problem on a + + + align:start position:0% +and so what is the sub problem on a +suffix well + + align:start position:0% +suffix well + + + align:start position:0% +suffix well +a natural version is just to solve the + + align:start position:0% +a natural version is just to solve the + + + align:start position:0% +a natural version is just to solve the +original problem + + align:start position:0% +original problem + + + align:start position:0% +original problem +bowling how do i maximize my score if + + align:start position:0% +bowling how do i maximize my score if + + + align:start position:0% +bowling how do i maximize my score if +all i were given were these pins + + align:start position:0% +all i were given were these pins + + + align:start position:0% +all i were given were these pins +suppose the pins to the left of i didn't + + align:start position:0% +suppose the pins to the left of i didn't + + + align:start position:0% +suppose the pins to the left of i didn't +exist + + align:start position:0% +exist + + + align:start position:0% +exist +how would i maximize my score on the + + align:start position:0% +how would i maximize my score on the + + + align:start position:0% +how would i maximize my score on the +remaining pins or for this suffix + + align:start position:0% +remaining pins or for this suffix + + + align:start position:0% +remaining pins or for this suffix +given these four pins what would i do + + align:start position:0% +given these four pins what would i do + + + align:start position:0% +given these four pins what would i do +and there's some weird sub problems here + + align:start position:0% +and there's some weird sub problems here + + + align:start position:0% +and there's some weird sub problems here +right if i just gave you the last pin + + align:start position:0% +right if i just gave you the last pin + + + align:start position:0% +right if i just gave you the last pin +what would you do + + align:start position:0% +what would you do + + + align:start position:0% +what would you do +nothing that's clearly different from + + align:start position:0% +nothing that's clearly different from + + + align:start position:0% +nothing that's clearly different from +what i would do globally here + + align:start position:0% +what i would do globally here + + + align:start position:0% +what i would do globally here +but i claim if i can solve all suffixes + + align:start position:0% +but i claim if i can solve all suffixes + + + align:start position:0% +but i claim if i can solve all suffixes +i can solve my original problem because + + align:start position:0% +i can solve my original problem because + + + align:start position:0% +i can solve my original problem because +one of the suffixes is the whole + + align:start position:0% + + + + align:start position:0% + +sequence + + align:start position:0% +sequence + + + align:start position:0% +sequence +so let's do it + + align:start position:0% + + + + align:start position:0% + +sort bot + + align:start position:0% + + + + align:start position:0% + +for bowling + + align:start position:0% + + + + align:start position:0% + +so here's our dynamic program uh the sub + + align:start position:0% +so here's our dynamic program uh the sub + + + align:start position:0% +so here's our dynamic program uh the sub +problems + + align:start position:0% + + + + align:start position:0% + +are suffixes so um + + align:start position:0% +are suffixes so um + + + align:start position:0% +are suffixes so um +all right b of i is the maximum score we + + align:start position:0% +all right b of i is the maximum score we + + + align:start position:0% +all right b of i is the maximum score we +could get + + align:start position:0% +could get + + + align:start position:0% +could get +possible + + align:start position:0% + + + + align:start position:0% + +with our starting + + align:start position:0% +with our starting + + + align:start position:0% +with our starting +if we started a game with pins + + align:start position:0% +if we started a game with pins + + + align:start position:0% +if we started a game with pins +um i i plus one up to + + align:start position:0% +um i i plus one up to + + + align:start position:0% +um i i plus one up to +n minus one okay which is a suffix of + + align:start position:0% +n minus one okay which is a suffix of + + + align:start position:0% +n minus one okay which is a suffix of +the pins + + align:start position:0% +the pins + + + align:start position:0% +the pins +very important whenever you write a + + align:start position:0% +very important whenever you write a + + + align:start position:0% +very important whenever you write a +dynamic program to define what your + + align:start position:0% +dynamic program to define what your + + + align:start position:0% +dynamic program to define what your +sub-problems are don't just say how to + + align:start position:0% +sub-problems are don't just say how to + + + align:start position:0% +sub-problems are don't just say how to +compute them + + align:start position:0% +compute them + + + align:start position:0% +compute them +but first say what is the goal of the + + align:start position:0% +but first say what is the goal of the + + + align:start position:0% +but first say what is the goal of the +subproblem this is a common mistake to + + align:start position:0% +subproblem this is a common mistake to + + + align:start position:0% +subproblem this is a common mistake to +forget + + align:start position:0% +forget + + + align:start position:0% +forget +to state what you're trying to do so now + + align:start position:0% +to state what you're trying to do so now + + + align:start position:0% +to state what you're trying to do so now +i have to find + + align:start position:0% +i have to find + + + align:start position:0% +i have to find +b of i um now what is the + + align:start position:0% +b of i um now what is the + + + align:start position:0% +b of i um now what is the +original thing i'm trying to solve i + + align:start position:0% +original thing i'm trying to solve i + + + align:start position:0% +original thing i'm trying to solve i +like to you can you can also put in sort + + align:start position:0% +like to you can you can also put in sort + + + align:start position:0% +like to you can you can also put in sort +by you could put the o + + align:start position:0% +by you could put the o + + + align:start position:0% +by you could put the o +earlier also then it's actually spell + + align:start position:0% +earlier also then it's actually spell + + + align:start position:0% +earlier also then it's actually spell +sort so why don't i do that for fun + + align:start position:0% +sort so why don't i do that for fun + + + align:start position:0% +sort so why don't i do that for fun +the original problem we're trying to + + align:start position:0% +the original problem we're trying to + + + align:start position:0% +the original problem we're trying to +solve is b + + align:start position:0% +solve is b + + + align:start position:0% +solve is b +of zero right because that is all of the + + align:start position:0% +of zero right because that is all of the + + + align:start position:0% +of zero right because that is all of the +pins the suffix starting at zero is + + align:start position:0% +pins the suffix starting at zero is + + + align:start position:0% +pins the suffix starting at zero is +everything + + align:start position:0% +everything + + + align:start position:0% +everything +so if we can solve that we're done next + + align:start position:0% +so if we can solve that we're done next + + + align:start position:0% +so if we can solve that we're done next +is + + align:start position:0% +is + + + align:start position:0% +is +r for relate this + + align:start position:0% +r for relate this + + + align:start position:0% +r for relate this +is the test of did i get the sub + + align:start position:0% +is the test of did i get the sub + + + align:start position:0% +is the test of did i get the sub +problems right is whether i can write + + align:start position:0% +problems right is whether i can write + + + align:start position:0% +problems right is whether i can write +a recurrence relation so let's try to do + + align:start position:0% +a recurrence relation so let's try to do + + + align:start position:0% +a recurrence relation so let's try to do +it + + align:start position:0% +it + + + align:start position:0% +it +we want to compute b of i + + align:start position:0% + + + + align:start position:0% + +so we have pin i here + + align:start position:0% +so we have pin i here + + + align:start position:0% +so we have pin i here +and then the remaining pins + + align:start position:0% +and then the remaining pins + + + align:start position:0% +and then the remaining pins +and the big idea here is to just think + + align:start position:0% +and the big idea here is to just think + + + align:start position:0% +and the big idea here is to just think +about + + align:start position:0% +about + + + align:start position:0% +about +the nice thing about suffixes is if i + + align:start position:0% +the nice thing about suffixes is if i + + + align:start position:0% +the nice thing about suffixes is if i +take off something from the beginning + + align:start position:0% +take off something from the beginning + + + align:start position:0% +take off something from the beginning +i still have a suffix remember my goal + + align:start position:0% +i still have a suffix remember my goal + + + align:start position:0% +i still have a suffix remember my goal +is to take this sub problem which is + + align:start position:0% +is to take this sub problem which is + + + align:start position:0% +is to take this sub problem which is +the suffix starting at i and reduce it + + align:start position:0% +the suffix starting at i and reduce it + + + align:start position:0% +the suffix starting at i and reduce it +to a smaller sub problem which means a + + align:start position:0% +to a smaller sub problem which means a + + + align:start position:0% +to a smaller sub problem which means a +smaller suffix + + align:start position:0% +smaller suffix + + + align:start position:0% +smaller suffix +so i'd like to clip off a couple one or + + align:start position:0% +so i'd like to clip off a couple one or + + + align:start position:0% +so i'd like to clip off a couple one or +two + + align:start position:0% +two + + + align:start position:0% +two +items here and then the remaining + + align:start position:0% +items here and then the remaining + + + align:start position:0% +items here and then the remaining +problem + + align:start position:0% +problem + + + align:start position:0% +problem +will be one of my sub problems i'll be + + align:start position:0% +will be one of my sub problems i'll be + + + align:start position:0% +will be one of my sub problems i'll be +able to recursively call b of something + + align:start position:0% +able to recursively call b of something + + + align:start position:0% +able to recursively call b of something +smaller than i + + align:start position:0% +smaller than i + + + align:start position:0% +smaller than i +or sorry b of something larger than i + + align:start position:0% +or sorry b of something larger than i + + + align:start position:0% +or sorry b of something larger than i +will be a smaller subsequence because + + align:start position:0% +will be a smaller subsequence because + + + align:start position:0% +will be a smaller subsequence because +we're starting later + + align:start position:0% +we're starting later + + + align:start position:0% +we're starting later +okay so what could i do well the idea is + + align:start position:0% +okay so what could i do well the idea is + + + align:start position:0% +okay so what could i do well the idea is +to just look at pin eye and think + + align:start position:0% +to just look at pin eye and think + + + align:start position:0% +to just look at pin eye and think +what what could i do to pin i i could + + align:start position:0% +what what could i do to pin i i could + + + align:start position:0% +what what could i do to pin i i could +not hit it ever with a ball i could skip + + align:start position:0% +not hit it ever with a ball i could skip + + + align:start position:0% +not hit it ever with a ball i could skip +it that's one option what would be my + + align:start position:0% +it that's one option what would be my + + + align:start position:0% +it that's one option what would be my +score then + + align:start position:0% +score then + + + align:start position:0% +score then +well i if i skip pin i + + align:start position:0% +well i if i skip pin i + + + align:start position:0% +well i if i skip pin i +that leaves the remaining pins which is + + align:start position:0% +that leaves the remaining pins which is + + + align:start position:0% +that leaves the remaining pins which is +just a smaller suffix + + align:start position:0% +just a smaller suffix + + + align:start position:0% +just a smaller suffix +so that is uh b of i plus one + + align:start position:0% +so that is uh b of i plus one + + + align:start position:0% +so that is uh b of i plus one +i'm going to write a max out here + + align:start position:0% +i'm going to write a max out here + + + align:start position:0% +i'm going to write a max out here +because i'd like to maximize my score + + align:start position:0% +because i'd like to maximize my score + + + align:start position:0% +because i'd like to maximize my score +and one of the options is + + align:start position:0% +and one of the options is + + + align:start position:0% +and one of the options is +forget about pin i just solve the rest + + align:start position:0% +forget about pin i just solve the rest + + + align:start position:0% +forget about pin i just solve the rest +another option is i + + align:start position:0% +another option is i + + + align:start position:0% +another option is i +throw a ball and i exactly hit pin i + + align:start position:0% +throw a ball and i exactly hit pin i + + + align:start position:0% +throw a ball and i exactly hit pin i +that's a thing i could do and it would + + align:start position:0% +that's a thing i could do and it would + + + align:start position:0% +that's a thing i could do and it would +it would leave exactly the same + + align:start position:0% +it would leave exactly the same + + + align:start position:0% +it would leave exactly the same +remainder + + align:start position:0% +remainder + + + align:start position:0% +remainder +so another option is b of i plus 1 + + align:start position:0% +so another option is b of i plus 1 + + + align:start position:0% +so another option is b of i plus 1 +plus v i uh why would i prefer this over + + align:start position:0% +plus v i uh why would i prefer this over + + + align:start position:0% +plus v i uh why would i prefer this over +this well if v i is negative + + align:start position:0% +this well if v i is negative + + + align:start position:0% +this well if v i is negative +i'd prefer this but if u is positive + + align:start position:0% +i'd prefer this but if u is positive + + + align:start position:0% +i'd prefer this but if u is positive +i'd actually prefer this over that okay + + align:start position:0% +i'd actually prefer this over that okay + + + align:start position:0% +i'd actually prefer this over that okay +so you're going to figure out which is + + align:start position:0% +so you're going to figure out which is + + + align:start position:0% +so you're going to figure out which is +which is better just locally + + align:start position:0% + + + + align:start position:0% + +but then there's another thing i can do + + align:start position:0% +but then there's another thing i can do + + + align:start position:0% +but then there's another thing i can do +which is maybe i hit this pin + + align:start position:0% +which is maybe i hit this pin + + + align:start position:0% +which is maybe i hit this pin +in a pair with some other pin now + + align:start position:0% +in a pair with some other pin now + + + align:start position:0% +in a pair with some other pin now +there's no pin to the left of this one + + align:start position:0% +there's no pin to the left of this one + + + align:start position:0% +there's no pin to the left of this one +we're assuming we only have the suffix + + align:start position:0% +we're assuming we only have the suffix + + + align:start position:0% +we're assuming we only have the suffix +and so the only other thing i can do is + + align:start position:0% +and so the only other thing i can do is + + + align:start position:0% +and so the only other thing i can do is +throw a ball and hit + + align:start position:0% +throw a ball and hit + + + align:start position:0% +throw a ball and hit +i together with i plus one and then i + + align:start position:0% +i together with i plus one and then i + + + align:start position:0% +i together with i plus one and then i +get the product + + align:start position:0% +get the product + + + align:start position:0% +get the product +now what pins remain i plus two on still + + align:start position:0% +now what pins remain i plus two on still + + + align:start position:0% +now what pins remain i plus two on still +a suffix + + align:start position:0% +a suffix + + + align:start position:0% +a suffix +so if i remove one or two items of + + align:start position:0% +so if i remove one or two items of + + + align:start position:0% +so if i remove one or two items of +course i still get a suffix + + align:start position:0% +course i still get a suffix + + + align:start position:0% +course i still get a suffix +in this case b of i plus two and then + + align:start position:0% +in this case b of i plus two and then + + + align:start position:0% +in this case b of i plus two and then +the number of + + align:start position:0% +the number of + + + align:start position:0% +the number of +points that i add on are vi times vi + + align:start position:0% +points that i add on are vi times vi + + + align:start position:0% +points that i add on are vi times vi +plus one + + align:start position:0% +plus one + + + align:start position:0% +plus one +so this is a max of three things + + align:start position:0% +so this is a max of three things + + + align:start position:0% +so this is a max of three things +so how long does it take me to compute + + align:start position:0% +so how long does it take me to compute + + + align:start position:0% +so how long does it take me to compute +it i claim + + align:start position:0% +it i claim + + + align:start position:0% +it i claim +constant time if i don't count the time + + align:start position:0% +constant time if i don't count the time + + + align:start position:0% +constant time if i don't count the time +it takes to compute these other + + align:start position:0% +it takes to compute these other + + + align:start position:0% +it takes to compute these other +subproblems which are smaller + + align:start position:0% +subproblems which are smaller + + + align:start position:0% +subproblems which are smaller +because they are smaller suffixes + + align:start position:0% +because they are smaller suffixes + + + align:start position:0% +because they are smaller suffixes +further to the right + + align:start position:0% +further to the right + + + align:start position:0% +further to the right +uh then i'm doing you know a couple of + + align:start position:0% +uh then i'm doing you know a couple of + + + align:start position:0% +uh then i'm doing you know a couple of +additions product + + align:start position:0% +additions product + + + align:start position:0% +additions product +max these are all nice numbers they will + + align:start position:0% +max these are all nice numbers they will + + + align:start position:0% +max these are all nice numbers they will +assume that they live in a w + + align:start position:0% +assume that they live in a w + + + align:start position:0% +assume that they live in a w +bit word um because they're only doing + + align:start position:0% +bit word um because they're only doing + + + align:start position:0% +bit word um because they're only doing +constant size products that's good + + align:start position:0% +constant size products that's good + + + align:start position:0% +constant size products that's good +uh so this takes constant constant + + align:start position:0% +uh so this takes constant constant + + + align:start position:0% +uh so this takes constant constant +non-recursive work + + align:start position:0% +non-recursive work + + + align:start position:0% +non-recursive work +how many sub-problems are but suffixes + + align:start position:0% +how many sub-problems are but suffixes + + + align:start position:0% +how many sub-problems are but suffixes +so it's a linear number of sub-problems + + align:start position:0% +so it's a linear number of sub-problems + + + align:start position:0% +so it's a linear number of sub-problems +and so the time i'm going to end up + + align:start position:0% +and so the time i'm going to end up + + + align:start position:0% +and so the time i'm going to end up +needing + + align:start position:0% +needing + + + align:start position:0% +needing +is the number of sub-problems n times + + align:start position:0% +is the number of sub-problems n times + + + align:start position:0% +is the number of sub-problems n times +the non-recursive work i do per sub + + align:start position:0% +the non-recursive work i do per sub + + + align:start position:0% +the non-recursive work i do per sub +problem which is constant + + align:start position:0% +problem which is constant + + + align:start position:0% +problem which is constant +and so this is linear time + + align:start position:0% +and so this is linear time + + + align:start position:0% +and so this is linear time +great now i didn't finish sort bot so + + align:start position:0% +great now i didn't finish sort bot so + + + align:start position:0% +great now i didn't finish sort bot so +there's + + align:start position:0% +there's + + + align:start position:0% +there's +another t which is to make sure that + + align:start position:0% +another t which is to make sure that + + + align:start position:0% +another t which is to make sure that +there is a topological order + + align:start position:0% +there is a topological order + + + align:start position:0% +there is a topological order +and that is in decreasing i order + + align:start position:0% + + + + align:start position:0% + +or i might write that as a for loop + + align:start position:0% +or i might write that as a for loop + + + align:start position:0% +or i might write that as a for loop +for i equals n n minus 1. + + align:start position:0% +for i equals n n minus 1. + + + align:start position:0% +for i equals n n minus 1. +this is the order that i would compute + + align:start position:0% +this is the order that i would compute + + + align:start position:0% +this is the order that i would compute +uh + + align:start position:0% +uh + + + align:start position:0% +uh +my problems because the suffix starting + + align:start position:0% +my problems because the suffix starting + + + align:start position:0% +my problems because the suffix starting +at n is the empty suffix + + align:start position:0% +at n is the empty suffix + + + align:start position:0% +at n is the empty suffix +the suffix starting at zero that's the + + align:start position:0% +the suffix starting at zero that's the + + + align:start position:0% +the suffix starting at zero that's the +one i actually want to compute that's + + align:start position:0% +one i actually want to compute that's + + + align:start position:0% +one i actually want to compute that's +the final suffix i should be computing + + align:start position:0% +the final suffix i should be computing + + + align:start position:0% +the final suffix i should be computing +and then we have a b for base case + + align:start position:0% +and then we have a b for base case + + + align:start position:0% +and then we have a b for base case +which is that first case b of n + + align:start position:0% +which is that first case b of n + + + align:start position:0% +which is that first case b of n +equals uh zero + + align:start position:0% +equals uh zero + + + align:start position:0% +equals uh zero +because there's no pins so i don't get + + align:start position:0% +because there's no pins so i don't get + + + align:start position:0% +because there's no pins so i don't get +any points + + align:start position:0% +any points + + + align:start position:0% +any points +sad + + align:start position:0% + + + + align:start position:0% + +okay so this is it we just take these + + align:start position:0% +okay so this is it we just take these + + + align:start position:0% +okay so this is it we just take these +components + + align:start position:0% +components + + + align:start position:0% +components +plug them into this recursive memoized + + align:start position:0% +plug them into this recursive memoized + + + align:start position:0% +plug them into this recursive memoized +algorithm + + align:start position:0% +algorithm + + + align:start position:0% +algorithm +and we have a linear time algorithm i + + align:start position:0% +and we have a linear time algorithm i + + + align:start position:0% +and we have a linear time algorithm i +want to briefly mention + + align:start position:0% +want to briefly mention + + + align:start position:0% +want to briefly mention +a different way you could plug together + + align:start position:0% +a different way you could plug together + + + align:start position:0% +a different way you could plug together +those pieces which is called bottom up + + align:start position:0% +those pieces which is called bottom up + + + align:start position:0% +those pieces which is called bottom up +dp + + align:start position:0% + + + + align:start position:0% + +which is uh let's do it for this example + + align:start position:0% +which is uh let's do it for this example + + + align:start position:0% +which is uh let's do it for this example +so if i have um + + align:start position:0% +so if i have um + + + align:start position:0% +so if i have um +let's see let me start with the base + + align:start position:0% +let's see let me start with the base + + + align:start position:0% +let's see let me start with the base +case + + align:start position:0% +case + + + align:start position:0% +case +b of n equals zero but now it's an + + align:start position:0% +b of n equals zero but now it's an + + + align:start position:0% +b of n equals zero but now it's an +assignment + + align:start position:0% +assignment + + + align:start position:0% +assignment +and i'm going to do the for loop from + + align:start position:0% +and i'm going to do the for loop from + + + align:start position:0% +and i'm going to do the for loop from +the topological order for i equals + + align:start position:0% +the topological order for i equals + + + align:start position:0% +the topological order for i equals +m n minus 1 to 0. + + align:start position:0% +m n minus 1 to 0. + + + align:start position:0% +m n minus 1 to 0. +now i'm going to do the relation b of i + + align:start position:0% +now i'm going to do the relation b of i + + + align:start position:0% +now i'm going to do the relation b of i +equals max of b of i plus 1 + + align:start position:0% +equals max of b of i plus 1 + + + align:start position:0% +equals max of b of i plus 1 +and b of i plus uh + + align:start position:0% +and b of i plus uh + + + align:start position:0% +and b of i plus uh +1 plus v i and v of i plus 2 + + align:start position:0% +1 plus v i and v of i plus 2 + + + align:start position:0% +1 plus v i and v of i plus 2 +plus v i v i plus 1. + + align:start position:0% +plus v i v i plus 1. + + + align:start position:0% +plus v i v i plus 1. +technically this only works if i is + + align:start position:0% +technically this only works if i is + + + align:start position:0% +technically this only works if i is +strictly less than n minus 1. + + align:start position:0% +strictly less than n minus 1. + + + align:start position:0% +strictly less than n minus 1. +so i should have an if i is less than n + + align:start position:0% +so i should have an if i is less than n + + + align:start position:0% +so i should have an if i is less than n +minus 1 for that last part + + align:start position:0% +minus 1 for that last part + + + align:start position:0% +minus 1 for that last part +because i can only do i can only hit two + + align:start position:0% +because i can only do i can only hit two + + + align:start position:0% +because i can only do i can only hit two +pins if there's at least two pins left + + align:start position:0% +pins if there's at least two pins left + + + align:start position:0% +pins if there's at least two pins left +and then return + + align:start position:0% + + + + align:start position:0% + +b of zero so what i just did is a + + align:start position:0% +b of zero so what i just did is a + + + align:start position:0% +b of zero so what i just did is a +transformation + + align:start position:0% +transformation + + + align:start position:0% +transformation +from this sort bot template into + + align:start position:0% +from this sort bot template into + + + align:start position:0% +from this sort bot template into +a non-recursive algorithm a for loop + + align:start position:0% +a non-recursive algorithm a for loop + + + align:start position:0% +a non-recursive algorithm a for loop +algorithm + + align:start position:0% +algorithm + + + align:start position:0% +algorithm +where i wrote my base case first then i + + align:start position:0% +where i wrote my base case first then i + + + align:start position:0% +where i wrote my base case first then i +did my + + align:start position:0% +did my + + + align:start position:0% +did my +topological order then i did my + + align:start position:0% +topological order then i did my + + + align:start position:0% +topological order then i did my +relation then at the end i did my base + + align:start position:0% +relation then at the end i did my base + + + align:start position:0% +relation then at the end i did my base +not base case the original problem + + align:start position:0% + + + + align:start position:0% + +and provided you can write your + + align:start position:0% +and provided you can write your + + + align:start position:0% +and provided you can write your +topological order as some for loops + + align:start position:0% +topological order as some for loops + + + align:start position:0% +topological order as some for loops +this is actually a great way to write + + align:start position:0% +this is actually a great way to write + + + align:start position:0% +this is actually a great way to write +down a dp as code if i were going to + + align:start position:0% +down a dp as code if i were going to + + + align:start position:0% +down a dp as code if i were going to +implement this algorithm i would write + + align:start position:0% +implement this algorithm i would write + + + align:start position:0% +implement this algorithm i would write +it this way because this is super fast + + align:start position:0% +it this way because this is super fast + + + align:start position:0% +it this way because this is super fast +no recursive calls + + align:start position:0% +no recursive calls + + + align:start position:0% +no recursive calls +just one for loop in fact this is almost + + align:start position:0% +just one for loop in fact this is almost + + + align:start position:0% +just one for loop in fact this is almost +a trivial algorithm it's amazing that + + align:start position:0% +a trivial algorithm it's amazing that + + + align:start position:0% +a trivial algorithm it's amazing that +this + + align:start position:0% +this + + + align:start position:0% +this +solves the bowling problem + + align:start position:0% +solves the bowling problem + + + align:start position:0% +solves the bowling problem +it's in some sense considering every + + align:start position:0% +it's in some sense considering every + + + align:start position:0% +it's in some sense considering every +possible strategy i could + + align:start position:0% +possible strategy i could + + + align:start position:0% +possible strategy i could +for bowling these pins what we're using + + align:start position:0% +for bowling these pins what we're using + + + align:start position:0% +for bowling these pins what we're using +is what we like to call + + align:start position:0% +is what we like to call + + + align:start position:0% +is what we like to call +local brute force where when we think + + align:start position:0% +local brute force where when we think + + + align:start position:0% +local brute force where when we think +about pin + + align:start position:0% +about pin + + + align:start position:0% +about pin +i we look at all of the possible things + + align:start position:0% +i we look at all of the possible things + + + align:start position:0% +i we look at all of the possible things +i could do to pin i + + align:start position:0% +i could do to pin i + + + align:start position:0% +i could do to pin i +here there's really only three options + + align:start position:0% +here there's really only three options + + + align:start position:0% +here there's really only three options +of what i could do + + align:start position:0% +of what i could do + + + align:start position:0% +of what i could do +now normally if i if i tried all the + + align:start position:0% +now normally if i if i tried all the + + + align:start position:0% +now normally if i if i tried all the +options for pin i + + align:start position:0% +options for pin i + + + align:start position:0% +options for pin i +and then all the options for i plus 1 + + align:start position:0% +and then all the options for i plus 1 + + + align:start position:0% +and then all the options for i plus 1 +and i plus 2 and so on that would be + + align:start position:0% +and i plus 2 and so on that would be + + + align:start position:0% +and i plus 2 and so on that would be +exponential it'd be 3 times 3 times 3 + + align:start position:0% +exponential it'd be 3 times 3 times 3 + + + align:start position:0% +exponential it'd be 3 times 3 times 3 +that's bad but because i can reuse these + + align:start position:0% +that's bad but because i can reuse these + + + align:start position:0% +that's bad but because i can reuse these +sub problems + + align:start position:0% +sub problems + + + align:start position:0% +sub problems +it turns out to only be linear time it's + + align:start position:0% +it turns out to only be linear time it's + + + align:start position:0% +it turns out to only be linear time it's +almost like + + align:start position:0% +almost like + + + align:start position:0% +almost like +magic dp + + align:start position:0% +magic dp + + + align:start position:0% +magic dp +dp dp is essentially an idea of + + align:start position:0% +dp dp is essentially an idea of + + + align:start position:0% +dp dp is essentially an idea of +using local brute force + + align:start position:0% + + + + align:start position:0% + +and by defining a small number of sub + + align:start position:0% +and by defining a small number of sub + + + align:start position:0% +and by defining a small number of sub +problems up front and + + align:start position:0% +problems up front and + + + align:start position:0% +problems up front and +as long as i stay within those sub + + align:start position:0% +as long as i stay within those sub + + + align:start position:0% +as long as i stay within those sub +problems as long as i'm always recursing + + align:start position:0% +problems as long as i'm always recursing + + + align:start position:0% +problems as long as i'm always recursing +into this polynomial space + + align:start position:0% +into this polynomial space + + + align:start position:0% +into this polynomial space +i end up only doing polynomial work even + + align:start position:0% +i end up only doing polynomial work even + + + align:start position:0% +i end up only doing polynomial work even +though i'm in some sense exploring + + align:start position:0% +though i'm in some sense exploring + + + align:start position:0% +though i'm in some sense exploring +exponentially many options + + align:start position:0% +exponentially many options + + + align:start position:0% +exponentially many options +and it's it's because what i do for this + + align:start position:0% +and it's it's because what i do for this + + + align:start position:0% +and it's it's because what i do for this +pin doesn't depend + + align:start position:0% +pin doesn't depend + + + align:start position:0% +pin doesn't depend +too much to what i do to a pin much + + align:start position:0% +too much to what i do to a pin much + + + align:start position:0% +too much to what i do to a pin much +later and there's a lot of intuition + + align:start position:0% +later and there's a lot of intuition + + + align:start position:0% +later and there's a lot of intuition +going on here for what + + align:start position:0% +going on here for what + + + align:start position:0% +going on here for what +uh when dp works but we're going to see + + align:start position:0% +uh when dp works but we're going to see + + + align:start position:0% +uh when dp works but we're going to see +a lot more examples of that + + align:start position:0% +a lot more examples of that + + + align:start position:0% +a lot more examples of that +coming up and i just want to mention + + align:start position:0% +coming up and i just want to mention + + + align:start position:0% +coming up and i just want to mention +that the intuition for how to write a + + align:start position:0% +that the intuition for how to write a + + + align:start position:0% +that the intuition for how to write a +recurrence like this + + align:start position:0% +recurrence like this + + + align:start position:0% +recurrence like this +is to think about in the case of + + align:start position:0% +is to think about in the case of + + + align:start position:0% +is to think about in the case of +suffixes you always want to think about + + align:start position:0% +suffixes you always want to think about + + + align:start position:0% +suffixes you always want to think about +the first item + + align:start position:0% +the first item + + + align:start position:0% +the first item +or maybe the first couple items the case + + align:start position:0% +or maybe the first couple items the case + + + align:start position:0% +or maybe the first couple items the case +of prefixes you always think about the + + align:start position:0% +of prefixes you always think about the + + + align:start position:0% +of prefixes you always think about the +last item + + align:start position:0% +last item + + + align:start position:0% +last item +and for sub strings it's could be any + + align:start position:0% +and for sub strings it's could be any + + + align:start position:0% +and for sub strings it's could be any +item maybe in the middle + + align:start position:0% +item maybe in the middle + + + align:start position:0% +item maybe in the middle +if i remove an item from the middle of + + align:start position:0% +if i remove an item from the middle of + + + align:start position:0% +if i remove an item from the middle of +the substring i get two substrings so i + + align:start position:0% +the substring i get two substrings so i + + + align:start position:0% +the substring i get two substrings so i +can recurse + + align:start position:0% +can recurse + + + align:start position:0% +can recurse +here or in general what we want to do is + + align:start position:0% +here or in general what we want to do is + + + align:start position:0% +here or in general what we want to do is +identify + + align:start position:0% +identify + + + align:start position:0% +identify +some feature of the solution that if we + + align:start position:0% +some feature of the solution that if we + + + align:start position:0% +some feature of the solution that if we +knew that feature + + align:start position:0% +knew that feature + + + align:start position:0% +knew that feature +we would be done we would reduce to a + + align:start position:0% +we would be done we would reduce to a + + + align:start position:0% +we would be done we would reduce to a +smaller sub problem + + align:start position:0% +smaller sub problem + + + align:start position:0% +smaller sub problem +in this case we just say well what are + + align:start position:0% +in this case we just say well what are + + + align:start position:0% +in this case we just say well what are +the possible things i could do + + align:start position:0% +the possible things i could do + + + align:start position:0% +the possible things i could do +to the first pin there are three options + + align:start position:0% +to the first pin there are three options + + + align:start position:0% +to the first pin there are three options +if i knew which option it was i would be + + align:start position:0% +if i knew which option it was i would be + + + align:start position:0% +if i knew which option it was i would be +done i could recurse and do my addition + + align:start position:0% +done i could recurse and do my addition + + + align:start position:0% +done i could recurse and do my addition +now i don't know which thing i want to + + align:start position:0% +now i don't know which thing i want to + + + align:start position:0% +now i don't know which thing i want to +do so just try them all + + align:start position:0% +do so just try them all + + + align:start position:0% +do so just try them all +and take the max and if you're + + align:start position:0% +and take the max and if you're + + + align:start position:0% +and take the max and if you're +maximizing you take the max if you're + + align:start position:0% +maximizing you take the max if you're + + + align:start position:0% +maximizing you take the max if you're +minimizing you take them in + + align:start position:0% +minimizing you take them in + + + align:start position:0% +minimizing you take them in +sometimes you take an or or an and there + + align:start position:0% +sometimes you take an or or an and there + + + align:start position:0% +sometimes you take an or or an and there +might be some combination function + + align:start position:0% +might be some combination function + + + align:start position:0% +might be some combination function +for optimization problems where you're + + align:start position:0% +for optimization problems where you're + + + align:start position:0% +for optimization problems where you're +trying to maximize or minimize something + + align:start position:0% +trying to maximize or minimize something + + + align:start position:0% +trying to maximize or minimize something +like shortest paths we're trying to + + align:start position:0% +like shortest paths we're trying to + + + align:start position:0% +like shortest paths we're trying to +minimize we put them in here + + align:start position:0% +minimize we put them in here + + + align:start position:0% +minimize we put them in here +so usually it's min or max and this is + + align:start position:0% +so usually it's min or max and this is + + + align:start position:0% +so usually it's min or max and this is +extremely powerful + + align:start position:0% +extremely powerful + + + align:start position:0% +extremely powerful +uh all you need to do the hard part is + + align:start position:0% +uh all you need to do the hard part is + + + align:start position:0% +uh all you need to do the hard part is +this + + align:start position:0% +this + + + align:start position:0% +this +inspired design part where you say + + align:start position:0% +inspired design part where you say + + + align:start position:0% +inspired design part where you say +what do i need to know that would let me + + align:start position:0% +what do i need to know that would let me + + + align:start position:0% +what do i need to know that would let me +solve my problem + + align:start position:0% +solve my problem + + + align:start position:0% +solve my problem +if you can identify that and the number + + align:start position:0% +if you can identify that and the number + + + align:start position:0% +if you can identify that and the number +of choices for what you need to know + + align:start position:0% +of choices for what you need to know + + + align:start position:0% +of choices for what you need to know +is polynomial then you will be able to + + align:start position:0% +is polynomial then you will be able to + + + align:start position:0% +is polynomial then you will be able to +get a polynomial dynamic program that's + + align:start position:0% +get a polynomial dynamic program that's + + + align:start position:0% +get a polynomial dynamic program that's +the intuition we'll see a lot more + + align:start position:0% +the intuition we'll see a lot more + + + align:start position:0% +the intuition we'll see a lot more +examples + + align:start position:0% +examples + + + align:start position:0% +examples +in the next three lectures \ No newline at end of file diff --git a/r5pXu1PAUkI.txt b/r5pXu1PAUkI.txt new file mode 100644 index 0000000000000000000000000000000000000000..3aa041119ab1f0b1e58bd13ffa6924d57a2320fc --- /dev/null +++ b/r5pXu1PAUkI.txt @@ -0,0 +1,3087 @@ +The following +content is provided + +under a Creative +Commons license. + +Your support will help MIT +OpenCourseWare continue + +to offer high quality +educational resources for free. + +To make a donation or +view additional materials + +from hundreds of MIT courses, +visit MIT OpenCourseWare + +at ocw.mit.edu. + +PROFESSOR: If you guys +want me to cover anything + +in particular, is +there anything you + +didn't understand in lecture? + +In the last section, I +covered the recursion trees + +because they will +be on the Pset, + +and people said they +were a bit unclear, + +so we can do that and cover less +of the stuff that I have here. + +Or if there's anything else, +you can tell me what you want. + +So there I cover recursion +trees because someone said, hey, + +can you go over that again? + +Is there any pain points? + +No? + +OK. + +So then I'm going to +give you the same choice + +that I gave to people +last time, and that + +is we can go over +recursion trees again, + +but if I do that, then I +won't have time to go over + +the code for deleting a node +from a binary search tree. + +So we'll go through +the theory and you guys + +will have to go through +the code on your own. + +But instead, we'll go +over recursion trees again + +and remember how you +solve a recurrence using + +recursion trees. + +The alternative is +we don't do that + +and we complete +the deletions part. + +AUDIENCE: I feel like +covering deletions, + +since we didn't do that in +lecture, that would probably + +be more helpful. + +PROFESSOR: Let's take a vote. + +Who wants to do deletions +in painstaking detail? + +So deletions and not recursion? + +Who wants to do recursion +trees and not deletion? + +AUDIENCE: It's about equal. + +PROFESSOR: It's equal +and nobody cares. + +I'm really sad. + +AUDIENCE: Let's do +both in half detail. + +PROFESSOR: OK, sure. + +Who remembers merge sort? + +What does merge sort +do really quick? + +AUDIENCE: It takes some +sort of unsorted array, + +splits it in half, and +then continually splits it, + +and then once it finally +gets to the point + +where you have arrays of two +elements, then it sorts them, + +and then sorts those, +and then sorts those. + +It's a fun thing. + +And then it merges [INAUDIBLE]. + +PROFESSOR: That's so much code. + +I don't like to write much code +because for every line of code + +that you write, you +might have a bug in it, + +so I like to write less code. + +So the way I do it is when I +get to an array size of one + +element, I know +it's already sorted. + +So merge sort. + +You have an array, +it's unsorted. + +Split it into two halves, +call merge sort on each half, + +assume that magically, they're +going to come back sorted, + +and then you merge +the sorted halves. + +How much time does merging take? + +OK. + +So the recursion for the +running time of merge sort? + +AUDIENCE: Why does +it take n time? + +Just too large? + +AUDIENCE: Isn't it +the finger thing where + +you take each element, +and you're like, this one, + +is that greater or less than, +then you put it in the array. + +So you get-- + +PROFESSOR: Please take my +word for it that it's order n. + +AUDIENCE: I'll explain it +and then I'll be confused. + +PROFESSOR: OK, so order n. + +What's the recursion? + +Don't give me the +solution because then I + +can't do the trees anymore, +so give me the recursion + +before it's solved. + +Give me the recurrence formula. + +So it starts with T of N, right? + +AUDIENCE: It starts with +N over 2 plus N, I think. + +PROFESSOR: Perfect. + +So you take the array, +you split it into two, + +you call merge sort on the +two halves of the arrays. + +So you call merge sort twice. + +That's why you have a 2 here. + +The 2 matters. + +Without it, you get +a different answer. + +And when you call it, +the arrays that you + +give it are half the +size, and then merge + +takes order and time. + +Splitting depends on what you're +using to store your arrays. + +Can be constant time or it +can be order N. So the time + +won't change because of split. + +How do we solve this recurrence? + +The recursion tree +method says that we're + +going to draw a call graph. + +So we start out +with a call to merge + +sort with an array +of size N. Then + +it's going to call +merge sort again, + +but after the array is split. + +So it's going to call merge +sort twice, size is N over 2. + +This guy gets an array of +N over 2, calls merge sort. + +Two arrays, sizes +N over 4, N over 4. + +This does the same. + +So this goes on forever and ever +and ever until at some point + +we reach our base case. + +So we're going to +have a bunch of calls + +here where the array size is? + +What's our base case? + +1. + +Excellent. + +So this is the call graph +for merge sort, and let's + +put the base case here so we +know what we're talking about. + +T of 1 is theta 1. + +Now inside the +nodes, we're going + +to put the cost for each +call without counting + +the sub-call, so +the children here. + +That's this guy here, +except instead of order N, + +I will write CN. + +Remember how sometimes +we use CN instead + +of the order of notation? + +The reason we do that is if I +put in the asymptotic notation, + +then we're going to be +tempted to sum them up. + +You're allowed to sum terms +using asymptotic notation as + +long as there's a +finite number of them, + +but here, it turns out there's +an infinite number of them. + +Also, if you go this way, +you can never go wrong. + +You always get the +right answer, so that's + +why we switch from +order N to CN. + +In order to merge sort +an array of size N, + +we're going to merge sort +two arrays of size N over 2 + +and then spend CN time +on doing the merge. + +What are the costs here? + +To sort an array +of N over 2, what's + +the cost outside +the cost to merge? + +AUDIENCE: C of N over 2. + +PROFESSOR: Perfect. + +C times N over 2. + +C times N over 2. + +How about here? + +AUDIENCE: C times N over 4. + +PROFESSOR: Perfect. + +CN over 4. + +My nodes are really ugly. + +I should have drawn them +like this from the beginning. + +CN over 4. + +There you go. + +How about down here? + +AUDIENCE: C of N +over 2 to the i. + +PROFESSOR: You're +going on step ahead. + +We'll do that right next. + +AUDIENCE: C of N +over log N, right? + +Because they're +log N levels, so-- + +PROFESSOR: Let's not worry +about the number of levels. + +You're ruining my steps. + +I was going to get to +that two steps after this. + +AUDIENCE: Is it just C? + +PROFESSOR: Yep. + +So array size is 1, right? + +So the cost is C. C, C, +C, C. OK, you guys got it + +if you're thinking +of levels already. + +The next thing I +want to do is I want + +to figure out how many +levels I have in this tree. + +Why do I care about that? + +The answer for T of N is the +sum of all these costs in here + +because the cost of merge +sorting an array of size N + +is the merge sort plus the costs +for sorting the two arrays. + +And the nodes here keep +track of all the time spent + +in recursive sub-calls, so if +we can add up everything up, + +we have the answer to T of +N. It turns out the easiest + +way to do that is to sum +up the cost at each level + +because the costs are +this guy copied over here. + +For a level, they +tend to be the same, + +so it's reasonably +easy to add them up, + +except in order to be +able to add those up, + +you have to know how +many levels you have. + +So how do I know how +many levels I have? + +Someone already told me log +N. How do I get to that log N? + +So when I get to the +bottommost level, + +the number has to be 1, the +number next to the node, + +because that's my base case. + +When I have a one element +array, it's sorted, I'm done. + +I return. + +So I can say that +for each level, + +the number next to the node is +something as a function of L. + +Here, I'm going to +say that this is + +N over 1, which is N +over 2 to the 0 power. + +And this is N over 2, so it's +N over 2 to the first power. + +This is N over 2 to the +second, and so on and so forth. + +It might not be obvious if +you only have two levels. + +I don't want to draw +a lot on the board + +because I don't have a lot +of space and I'd get my nodes + +all messed into each other. + +If it takes more than two levels +to see the pattern, go for it. + +Expand for three levels, +four levels, five levels, + +whatever it takes to get it +right on a Pset or on a test. + +So you see the pattern, +then you write the formula + +for the node size at the level. + +And assuming this +pattern holds, we + +see that the size of a +node at level l, the size + +is 2 N over 2 to the l minus 1. + +Fair enough? + +You can say N over 2 +to the l, and forget + +that there's a minus 1, and then +the asymptotics will save you, + +so it's no big deal, but +this is the real number. + +So that means that at the +bottommost level, at level l, + +this size is going to be 1. + +N over 2 to the l +minus 1 equals 1. + +So now this is an equation, +so I can solve for l. + +I pull this on the right side, +N equals 2 to the l minus 1, + +so l minus 1 equals-- anyone? + +The inverse of an exponential? + +AUDIENCE: I wasn't +paying attention. + +Sorry. + +AUDIENCE: Log N. + +PROFESSOR: The inverse of an +exponential is a logarithm. + +Keep that in mind for +solving 6.006 problems. + +l minus 1 is log N so l is +log n plus 1, roughly log n. + +I could use log n plus 1 +and go through the math. + +It's a bit more painful +and, because we're + +using asymptotics, it +doesn't really matter. + +So now we know how +many levels we have. + +Let's see what's the +cost at the level. + +So all the calls +at a certain level, + +what's the sum of the costs? + +For this level, what's the cost? + +CN. + +And That was the easy question. + +Just the root, right? + +How about this level? + +Because I have two nodes, the +cost in each node is CN over 2. + +How about this level? + +Four levels, each +level CN over 4. + +How about the bottom level? + +AUDIENCE: CN. + +PROFESSOR: Why is it CN? + +AUDIENCE: Because there +are N arrays of size 1. + +PROFESSOR: N arrays of size 1. + +Excellent. + +A cute argument I heard once +is you start out with N, + +you split it into N +over 2 and N over 2. + +Then you split this guy +in N over 4, N over 4, + +so this is like +conservation of mass. + +If you start with N and here, +you don't end up with N total, + +then you lost some element +somewhere on the way. + +So CN. + +CN, CN, CN, CN. + +I think I see a pattern. + +I think it's reasonable to say +that for every level, it's CN. + +And if you write the +proof, you can prove that + +by using math instead +of waving hands. + +So CN times the number +of levels, right? + +The answer for this guy +is C of N is CN times l. + +What's l? + +AUDIENCE: N log N. + +PROFESSOR: Roughly. + +OK So order of N +log N. C becomes + +order of, l is order of +log N, N stays the same. + +Any questions? + +Are people getting it or +did I confuse you even more? + +AUDIENCE: We got it. + +PROFESSOR: OK, sweet. + +Thank you for the encouragement. + +So this gets you through +problem one of Pset 2. + +So in this case, the +tree is nicely balanced. + +The cost at each +level is the same. + +When [INAUDIBLE] talked about +recursion trees in lectures, + +he showed two more +trees, one where + +pretty much all the cost was up +here-- the cost of the children + +was negligible-- and one +tree where all the cost was + +concentrated here, so the +cost of all the inner nodes + +was negligible and the leaves +were doing all the real work. + +So don't be scared if your +costs aren't the same. + +Just sum them up and you'll +get to the right answer. + +Now I'm going to talk +about binary search trees, + +except I will make a five +minute general talk about data + +structures before I do that. + +So we use the term +"data structures." + +I think we covered +it well, and I + +want to give you +a couple of tips + +for dealing with them on Pset 1. + +A data structure is +a bunch of algorithms + +that help you store and +then retrieve information. + +You have two types +of algorithms. + +You have queries, +and you have updates. + +You start out with an +empty data structure, + +like an empty binary search +tree or an empty list, + +and then you throw +some data at it. + +That's when you update it. + +Then you ask it some questions, +and that's when you query it. + +Then maybe you throw more data +at it, so you do more updates, + +and you ask more questions, +so you do more queries. + +What are the queries +and the updates + +for the binary search trees +that we talked about in lecture? + +AUDIENCE: A query +would be like, what's + +your right child, +what's your left child? + +PROFESSOR: So that's for a node. + +AUDIENCE: What are +you looking for? + +PROFESSOR: I'm +looking for something + +for the entire infrastructure. + +So for the entire +tree, what's a question + +that you would ask the tree? + +PROFESSOR: Max. + +PROFESSOR: OK. + +Min. + +AUDIENCE: Next larger. + +PROFESSOR: Next larger. + +Are you looking at the nodes? + +AUDIENCE: Is there an are +you balanced question? + +PROFESSOR: Well, I would say +that the most popular operation + +in a binary search +tree is Search, which + +looks for-- we call +it Find in the code + +because most code +implementations call it Find + +nowadays, but +binary search tree. + +What are you going to do in it? + +You search for a value. + +That's why it has the +Search in binary search. + +So queries are operations where +you ask questions to the data + +structure and it doesn't change. + +How about updates? + +What did we learn for updates? + +AUDIENCE: Insert. + +PROFESSOR: Excellent. + +So Insert was +covered in lecture, + +and we're doing Delete today. + +So data structures +have this property + +that's called the +representation invariant, RI, + +or Rep Invariant. + +Actually, before I get +there, the rep invariant + +says that the data in +the data structures + +is organized in this +way, and as long + +as it's organized in this way, +the data structure functions + +correctly. + +Can someone guess +for a sorted array + +what's the +representation invariant? + +AUDIENCE: It can mean sorted. + +PROFESSOR: Yeah. + +A sorted array should be sorted. + +Sounds like a very +good rep invariant. + +So the elements should +be stored an array. + +Every element should be smaller +than any element after it. + +And as long as the rep +invariant holds, so as long + +as elements are stored in +the right way in the data + +structure, the queries will +return the right results. + +If the rep invariant +doesn't hold, + +then God knows what's +going to happen. + +What can you do +in a storage array + +as long as the rep +invariant holds? + +Sorted array. + +What's the reason why I +would have a sorted array? + +What can I do that's +fast in a sorted array? + +AUDIENCE: Min and Max. + +PROFESSOR: I can +do that very fast. + +That's good. + +What's the running time? + +AUDIENCE: A constant. + +PROFESSOR: Perfect. + +Min you look at the beginning, +Max you look at the end. + +Yes? + +AUDIENCE: Binary search. + +PROFESSOR: Binary search. + +That's the other +reason for that. + +So binary search +runs in order log + +N time, doesn't have to +look at most of the array, + +tells you whether an +element is there are not. + +Now, what if the +array is unsorted? + +Will the algorithm work? + +It might say +something isn't there + +when it actually is there. + +You can do binary search +on a non-sorted array. + +So if the rep +invariant doesn't hold, + +your queries might give +you a wrong answer. + +How about updates? + +How do you search +something in a sorted list? + +AUDIENCE: You find +where it should go + +and you move everything. + +PROFESSOR: Yep. + +So you have to move +everything, make room for it, + +and put it there so +that the array is still + +sorted at the end. + +You can't just append +things at the end, + +even though that would be +faster and lazier and less code. + +When you do an update +to a data structure, + +you have to make sure that +the rep invariant still + +holds at the end. + +Sort of a correctness proof +for an update algorithm + +says that if the rep invariant +holds at the beginning, + +the rep invariant is +guaranteed to hold at the end. + +Why do we care about +this rep invariant stuff? + +Suppose you have a problem, +say on the next Pset, that + +asks you to find the place +that's slow in your code + +and then speed it up. + +And suppose you recognize +the data structure there, + +and you say that's +inefficient, and you + +want to implement another +data structure that + +would be more efficient. + +You're going to implement it. + +You might have +bugs in an update. + +How do you find the bugs? + +Queries give you +the wrong answers. + +You might do queries a long +time after you do updates, + +and you're not going to +know which update failed. + +The right way to do this +is you implement the method + +called Check RI-- that's +what I call it-- so + +check the representation +invariant. + +And that method walks through +the entire data structure + +and make sure that the +rep invariant holds, + +and if it doesn't, it +raises an exception + +because you know that whatever +you try to do from there + +is not going to work, so +there's no reason to keep going. + +So at the end of every +update, you add a call + +to this Check RI +method until you're + +sure that your code is correct. + +And after you're done +debugging your code, + +you remove this method +and you submit the code. + +Why do I want to +remove the method? + +It might be painfully slow +and inefficient, much slower + +than the actual +queries and updates. + +For example, let's take a heap. + +Do people remember +heaps from lecture? + +What's the query for a heap? + +Say you have a max heap. + +What's a query? + +AUDIENCE: Where's the max? + +PROFESSOR: OK, cool. + +So for a max heap, a +query would be max. + +Running time? + +AUDIENCE: Constant. + +PROFESSOR: Perfect. + +Constant. + +What do you do? + +Look at the top? + +AUDIENCE: Yeah, exactly. + +PROFESSOR: OK. + +Sweet. + +So what are the two popular +updates in a max heap? + +AUDIENCE: There would +be Insert as well. + +PROFESSOR: OK. + +Insert. + +And did we teach +you general delete? + +Usually Extract Max is simpler. + +That's all you need. + +What's the running +time for Insert? + +Do people remember heaps? + +AUDIENCE: I think it was per +N, but I'm not completely sure. + +PROFESSOR: Anyone else? + +It's not. + +Life would be bad +if it would be N. + +AUDIENCE: N squared? + +PROFESSOR: No. + +It's better than N, so you +guys are doing a binary search + +over the few running times +that I gave you earlier. + +AUDIENCE: [INAUDIBLE] +add to the N, + +and then you compare your +neighbor, and then you + +[INAUDIBLE]. + +AUDIENCE: If it's an +array, there isn't-- + +PROFESSOR: So conceptually, +a heap looks like this. + +And yeah, it becomes +an array eventually, + +but let's look at it this way. + +It is a full binary tree. + +Binary tree means that each +node has at most two children, + +and full means that every +level except for the last level + +is completely populated. + +So every internal node +has exactly two children, + +and in here, every node +except for some nodes + +and then some nodes +after it will not have. + +Everything to the left +is fully populated, + +and then at some point, +you stop having children. + +It turns out that this is +easy to store in an array, + +but I will not go over that. + +Instead, I want to +go over inserting. + +What's the rep +invariant for a heap? + +AUDIENCE: The max +in the top, right? + +Well, for max heap, and +then the two children + +are less than the next node. + +PROFESSOR: All right. + +So the guy here has to be +bigger than these guys, + +then the guy here has to +be bigger than these guys, + +and so on and so forth. + +And if you use +induction, you can + +prove that if this +is bigger than this, + +it has to be bigger than +these guys, and bigger + +than these guys, and bigger +than everything, and it's a max. + +That's the reason why we +have that rep invariant. + +So the way we insert +a node is we add it + +at the bottom, the only +place where we could add it. + +And then if this guy is +bigger than this guy, + +the rep invariant is +violated, so we swap them + +in order to fix that. + +Now the guy is here. + +If this is bigger than +this, we do another swap. + +If this is bigger than +this, we do another swap. + +So you're going to go from the +bottom of the heap potentially + +all the way up to the root. + +So the running time +of insert is order + +of the height of the heap. + +Now, the heap is a +full binary tree. + +I said "full." + +I keep saying "full." + +The reason I care about full +is that the full binary tree + +is guaranteed to have a +height of log N. It's always + +log N, where N is +the number of nodes. + +So inserting in a +heap takes log N. + +AUDIENCE: I have a question. + +Didn't they say that +because it's in an array, + +then to find it-- oh no, I +guess because you can still + +do the swaps. + +PROFESSOR: You can +still do the swaps + +when you have it +serialized in an array. + +You know that given +an item's index, + +the parent is that +index divided by 2. + +So you add an element +at the end of the array, + +and then you know +what the parent is, + +and then you keep swapping +and swapping and swapping + +towards the [INAUDIBLE]. + +AUDIENCE: You don't +ever have to put it in + +and shift everything over. + +You're only swapping. + +PROFESSOR: Yep. + +You only swap. + +That's important. + +Thanks for asking. + +That's important. + +So log N. Extract max, +take my word for it, + +also log N. What's the +running time for checking + +the invariant in a heap? + +So to make sure that this guy is +a heap, if I had numbers here, + +what would you have to do? + +AUDIENCE: You'd have +to look at every node. + +PROFESSOR: Yep. + +So running time? + +AUDIENCE: Theta of N. + +PROFESSOR: Yep. + +So if I'm going to +submit code for a heap + +where the operations +are our order of log N, + +or order 1, but then each +of these calls Check RI, + +that's going to be +painfully slow because I'm + +making the updates be +order N instead of log N. + +So you're putting Check +RI calls in every update. + +You debug your code. + +When you make sure it's +correct, you remove those, + +and then you submit the Pset. + +Make sense? + +Sweet. + +And we looked a little bit +at heaps, which is good. + +Binary search trees. + +So a binary tree is a +tree where every node + +has at most two children. + +When we code this up, we +represent a node as a Python + +object, and for a node, we +keep track of the left child, + +of the right child, parent, +and then this is a hollow tree. + +It's not very useful. + +This becomes useful when you +start putting keys in the nodes + +so that you can find them and +do other things with them. + +So each node has a key. + +Let me draw a +binary search tree. + +Can people see this? + +So this is a binary tree. + +Can someone say something a +bit more specific about it? + +AUDIENCE: It's unbalanced. + +PROFESSOR: OK. + +It's imbalanced. + +So that means that +finding things all the way + +at the bottom is +going to be expensive. + +What else? + +So I said it's a binary tree. + +Give me something more specific. + +So binary tree just means that +every node has two children. + +There's a bit more +structure in this guy. + +So if I look at the +root, if I look at 23, + +all the nodes to the +left are smaller. + +All the nodes to the +right are bigger. + +Now, if I look at 8, all the +nodes to the left are smaller, + +all the nodes to the +right are greater. + +This additional rep invariant +defines a binary search tree. + +This is what we +talked about in class. + +BST. + +Why would I want to +have this rep invariant? + +It sounds like a pain +to maintain nodes + +with all these +ordering constraints. + +What's the advantage +of doing that? + +AUDIENCE: Search is fast. + +PROFESSOR: Yep. + +Search is fast. + +How do I do search? + +If you're looking +for 42 or for 16, + +you'd be like, oh, +it's less than 23. + +I'll get on this path. + +PROFESSOR: So start at the root, +compare my key to the root. + +If it's smaller, go left. + +If it's bigger, go right. + +Then keep doing that +until I arrive somewhere + +or until I arrive at a dead +end if I'm looking for 14. + +This is a lot like +binary search. + +Binary search in an array, +you look at the middle. + +If your key is smaller, go left. + +If your key is +bigger, then go right. + +Let's look at the +code for a little bit. + +Look at the BST Node +Class, and you'll + +see that it has the fields +that we have up here. + +And look at the Find method, +and this is pretty much + +the binary search code. + +Lines 8 and 9 have the return +condition when you're happy + +and you found the key, +and then line 10 compares + +the key that you're looking +for with the key in the node + +that you're at, and then lines +11, 14, 16, and 19 are pretty + +much copy pasted, +except one of them + +deals with the left +case, the other one + +deals with the right case. + +What is the running +time for Find? + +AUDIENCE: Wouldn't +it be log N, right? + +PROFESSOR: I wish. + +If this is all you have +to do to get log N, + +then I would have to +write a lot less code. + +So not quite log N. We will +have to go through next lecture + +to get to log N. Until then, +what's the running time? + +AUDIENCE: Order h. + +PROFESSOR: Yep. + +So you told me at the +beginning it's unbalanced. + +AUDIENCE: Yeah. + +PROFESSOR: So then it's +not going to be fast. + +OK, so order h. + +The reason why we care +about h, and the reason + +we don't say order +N, is because next + +lecture after we learn +how to balance a tree, + +there's some magic that you can +do to these binary search trees + +to guarantee that the +height is order of log N. + +And then we'll go through all +the running times that we have + +and replace h with log N. + +Now, it happens that in this +case, if you would have told + +me order N, I couldn't argue +with you because worst case, + +searches are order N. Can +someone give me a binary search + +tree that exposes +this degenerate case? + +Yes? + +AUDIENCE: If it's +completely unbalanced + +and every node is greater +than the parent nodes. + +PROFESSOR: So give me some +inserts that create it. + +AUDIENCE: Insert 5. + +PROFESSOR: 5. + +AUDIENCE: Insert 10. + +PROFESSOR: 10. + +AUDIENCE: Insert 15. + +PROFESSOR: 15. + +AUDIENCE: Insert 20. + +PROFESSOR: Yep. + +And I could keep going. + +I could say, 1, 2, 3, 4, 5. + +I could say 5, 10, 15. + +As long as these keep +growing, this is basically + +going to be a list, +so searching is + +order N. This is +a degenerate case. + +Turns out it doesn't happen +too often in practice. + +If you have random data, the +height will be roughly log N. + +But in order to avoid +those degenerate cases, + +we'll be doing balanced +trees later on. + +So we covered Find. + +We know it's order h. + +How do you insert, +really quickly? + +AUDIENCE: Do you +mean in searching + +when it's balanced +or unbalanced? + +PROFESSOR: This guy. + +So the trees look +exactly the same. + +If it's balanced, it's +going to look more + +like that than like this. + +Actually, this is balanced. + +This is perfectly unbalanced. + +This is somewhere in the middle. + +If it's balanced, it's just +going to look more like this, + +but it's still a +binary search tree. + +How would you insert a node? + +Yes? + +AUDIENCE: Can't you +start at the root + +and find your way down, and +then the first open child + +that you see that's applicable +to your element, state it then? + +PROFESSOR: Yep. + +So if I wanted to insert +14, which way do I go? + +AUDIENCE: So you'd look +at 23, and you'd say, + +it's less than 23, go left. + +You'd look at 8. + +You'd say, it's greater than 8. + +You'd go right. + +Look at 16. + +You'd say it's less, +so you go left. + +15, it's less. + +Then you have an open spot +so you stick it there. + +PROFESSOR: Excellent. + +Thank you. + +Yes? + +AUDIENCE: I have a question. + +What if we want to insert 5? + +Then-- + +PROFESSOR: So if you +want to insert who? + +AUDIENCE: 5. + +Or actually no, we can't. + +I'm thinking, is there any case +in which need to move a node? + +PROFESSOR: How +would you insert 5? + +Let's see. + +What would you do for 5? + +AUDIENCE: For 5, then we'd +insert it to the right of 4, + +right? + +PROFESSOR: Smaller, +smaller, greater, 5. + +Right? + +AUDIENCE: So there would +be no case in which we'd + +need to swap nodes or something? + +PROFESSOR: No. + +You're thinking ahead. + +We'll talk about that a little +later when we get to deleting. + +As long as you follow a path in +the tree, the path that finding + +would get you to, as soon +as you hit a dead end, + +that's where your node belongs. + +Because you know next time +you're going to search for it, + +the search is going to follow +that path and find the node. + +Yes? + +AUDIENCE: If you have values +are the same, like two + +nodes at the same +number, does it + +matter which side you put it on? + +PROFESSOR: You don't. + +AUDIENCE: Oh, I see. + +It's more like you would only +have four 1's in the tree. + +PROFESSOR: Yes. + +So if you're trying to +store keys and values, + +then what you'd +have to do if you + +want to allow multiple +values for the same key + +is you have a linked +list going off + +of this, which node +becomes an array of values + +aside from the key. + +Smart question. + +Thank you. + +That trips you up every +time you do actual code, + +so that's the right +question to ask yourself + +when you're implementing this. + +Will I have duplicates? + +How do I handle them? + +We don't. + +We take the easy way out. + +So if you look at +Insert, on the next page, + +you will see that the code +is pretty much the Find code + +copy pasted, except +when Self Left is None + +or Self Right is None, +instead of returning, + +it creates a new node. + +Does that make sense to people? + +All right. + +So Delete is going to be the +hardest operation for today. + +Before we do that, let's +do a warm up operation. + +Let's say I want to implement +Find Next Larger, also called + +Successor in some +implementations. + +So I have a node. + +Say I have node 8, and I +want to find the next key + +in the tree that's +strictly larger than 8 + +but smaller than anything else. + +So if I would take these nodes +and write them down in order, + +I want to find the element +that would go right after it. + +How do I do that? + +Don't cheat. + +Don't look at the code, or make +my life easier and do searches. + +AUDIENCE: Go down +one to the right, + +and you try to get down +left as far as you can. + +PROFESSOR: OK. + +Very good. + +So I have a node, and it +has some subtree here, + +so I can go to the right here, +I can go all the way left. + +We have an operation +that does this, + +and it's called Min for a tree. + +In order to find the minimum +in a binary search tree, + +you keep going left. + +For example, in this case, +you get 4, which is good. + +So the way you would code +this up is if you have Min, + +you go to the right +if you can, and then + +you call Min on the subtree. + +And you can see that lines +3 and 4 do exactly that. + +Good guess. + +But you can line +1 says case one, + +so you have the right +answer for one case. + +Now we have to handle +more difficult cases. + +What if instead, I go +down a bunch of nodes, + +and I want to find the successor +for this guy, for example, + +and there's nothing here. + +What do I do? + +So if I want to find the +successor for 8, what do I do? + +Sorry. + +It has an answer. + +What if I want to find +the successor for 4? + +AUDIENCE: Go up one. + +PROFESSOR: OK. + +Go up one. + +Why does that work? + +AUDIENCE: You know it's +going to be greater. + +PROFESSOR: So I'm +going up right. + +So I know that everything here +is guaranteed to be smaller, + +everything here is guaranteed +to be greater than this guy. + +This guy is up right, so this +is guaranteed to be greater + +than this, and +everything here is + +guaranteed to be greater than +this, and so on and so forth + +for the entire tree. + +So if I go up right, I'm happy. + +I definitely found my answer. + +Now, what if I have something +that looks like this, + +and I want to find the +successor for this guy? + +AUDIENCE: There is none. + +PROFESSOR: In this +case, there is none + +if there's nothing else here. + +What if I have this, +but then I have this? + +So I came down this way. + +AUDIENCE: Are you saying you're +calling on that last node? + +PROFESSOR: Yep. + +AUDIENCE: Find the larger? + +I guess you'd just +trace back up. + +PROFESSOR: And where do I stop? + +AUDIENCE: It affects the tree, +so you go up one from there. + +You don't stop there. + +PROFESSOR: Why +can't I stop here? + +AUDIENCE: Because you know +that that-- not necessarily. + +AUDIENCE: You know that +everything in that long branch + +right there is less than +that node [INAUDIBLE]. + +PROFESSOR: This is to +the left of this guy, + +so this guy has to be +greater than everything here, + +and then you can repeat the +argument that we had before. + +So here, we could +stop right away + +because we could branch left. + +In this case, you have +to go up until you're + +able to go left and up. + +If you get to the root, +then what happened? + +Then we're in this case, +and you have no successor. + +So take a look at the code. + +The next larger, +lines 1 through 9. + +Case two, 6 through +8, does exactly that. + +If I can't go to my right +and find the tree there, + +then I go up through +my parent chain, + +and as long as I have +to go up to the left, + +so as long as I'm the +right child of my parent, + +I have to keep going. + +The moment I find the parent +where I'm the left child, + +I stop. + +That's my successor. + +What if I would have to find +the predecessor instead? + +So the element that's +smaller than me + +but bigger than everything +else in the tree. + +What would I do? + +AUDIENCE: It's +just the opposite. + +PROFESSOR: Just the opposite. + +So how do I do the opposite? + +AUDIENCE: You can take the +max of the left side tree, + +or traverse up, and +if that's less than-- + +PROFESSOR: OK, so if I +have a left subtree, fine. + +Call max on it and get +the rightmost node there. + +If not, I go up, +and when do I stop? + +When I go left or right? + +AUDIENCE: You'd +have to go right. + +Is that right? + +PROFESSOR: Yep. + +So last time, in this +case, when I was going up, + +if I was going left, +I had to keep going, + +and the moment I went right, +I was happy and I stopped. + +What if I want to +find the predecessor? + +It's the opposite, right? + +So I will go this way, and +the moment I can go this way, + +I'm done. + +How do you do this in code? + +Slightly tricky. + +Just slightly, I promise. + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: It's hard. + +What I would do is +copy paste the code, + +replace "left" with "right" +everywhere, and replace "min" + +with "max." + +You get it done. + +So we talked about how the +tree is symmetric, right? + +So every time, instead of +saying "left," you say "right," + +and instead of saying +"min," you say "max." + +That's how you do this. + +How do we do deletions? + +So suppose I'm in this tree +and I want to delete 15. + +What do I do? + +AUDIENCE: Kill it. + +PROFESSOR: Kill it. + +Very good. + +What if I want to delete 16? + +What do I do? + +AUDIENCE: You need to +put 15 where 16 is. + +PROFESSOR: OK. + +So I would put 15 here. + +So I had 16. + +Suppose I have a big tree here. + +Actually, let's go +for an easier case. + +Let's say I have this tree here. + +So you're here, you +have a big tree here, + +you don't have +anything here, and you + +want to delete this guy. + +AUDIENCE: You know +that everything less + +than the top node is +going to be less than it, + +so you can just move that up. + +PROFESSOR: Everything +less than this guy is also + +going to be less than this guy. + +So you're saying move +the whole tree up. + +AUDIENCE: Yep. + +PROFESSOR: So the +way we do that is + +we'd take this node's left +link and make it point here, + +and take this guy's parent +link and make it point here, + +and this guy sort of goes away. + +So we have two +cases for deleting. + +We have if you're a +leaf, we'll take you out. + +Sorry. + +I got confused. + +If you have one +child and that child + +is in the same direction as your +parent, then you can do this. + +What if you have one child, +but it's a zigzag like this? + +What do you do? + +AUDIENCE: It's still greater +than, so you do the same thing. + +PROFESSOR: Exactly. + +Same thing. + +Just change this guy, change +this guy, and I'm happy. + +So it doesn't matter if you have +a zigzag or a straight line. + +It might help you think +about it to convince yourself + +that the code is correct, but in +the end, you do the same thing. + +Now, what if I want +to delete node 8? + +So what if I have a nasty case +where I want to delete this guy + +and it has children both on +the left and on the right? + +AUDIENCE: You have to take +8, compare it to its parent + +and compare it to +its right child, + +and see which one +is greater in order + +to figure out which node +gets replaced in its spot. + +PROFESSOR: OK. + +So there is replacing +that's going to happen. + +The answer is really tricky. + +I always forget +this when coding. + +Try to understand it, +and if it doesn't work, + +refer to the textbook. + +When you forget it, because +you will, refer to the textbook + +or to the internet. + +So what you do is I can't just +magically replace this node + +with one of the subtrees, +but we talked right + +before this about Next Greater, +so finding a node's successor. + +If this node has both a left +subtree and a right subtree, + +then I know that if I +call Find Successor on it, + +I'm going to go +somewhere inside here, + +and I'm going to find a node +somewhere in here all the way + +to the left that is +this guy's successor. + +So what I'm going +to do is I'm going + +to delete this node instead, and +then I'm going to take its key + +and put it up here. + +So if I want to delete 8, what +I do is I find its successor, + +then I delete it, then I take +the 15 that was here-- you + +can see it, right? + +It's still there. + +Put it here. + +So the reason this works +is that everything here + +is greater than this guy. + +Everything here is +smaller than this guy. + +This is the next node that's +greater than this guy, + +but everything else +is bigger than it, + +right, because we wanted +it to be a successor. + +So if I take this value +and I put it up here, + +everything in here is still +going to be greater than it. + +This is a successor of this +guy, so everything here + +is still going to be +smaller than the successor. + +Great. + +In order to do a delete, +I find the successor, + +and then I call Delete on it. + +How do I know that +this will end? + +How do I know that +I'm not going to go + +into a loop that runs forever? + +AUDIENCE: Because it's not-- + +AUDIENCE: It's acyclic, right? + +PROFESSOR: OK. + +First answer, good. + +Eventually, worst case, I'm +going to get to the maximum, + +and then not going on have to +delete the successor anymore. + +Now, another thing +to note here is + +that if this guy is the +successor of this guy, + +it can't have anything on the +left, because if it would, + +then whatever is down here +has to be bigger than this, + +and whatever's to +the left of this node + +has to be smaller than this. + +But we said that this is +the successor of this, + +so there's nothing here. + +So this will be one of the easy +cases that we talked about. + +The successor +either has no kids, + +or it has only one +child, only one subtree. + +So then I can delete it +using one of the easy cases. + +So in fact, worst case that +happens in a delete is my node + +has two subtrees. + +Then I find the successor that's +only going to have one subtree, + +I change my links +there, and I'm done. + +What is the running +time for Delete? + +AUDIENCE: Is it order h, +because you should do it + +all the way down to the +bottom of the tree, right? + +PROFESSOR: You have +the right answer. + +Let's see why it's order h. + +It has to be order h, right? + +Otherwise, the tree +would be too slow. + +If it's order N, then it's bad. + +So why would Delete be order h? + +This was a heap, right, +so I can't use this. + +I'm going to write +"delete" here again. + +So the first thing you do is +you have to search for the key, + +right? + +That's order h. + +Now, if it's a happy case, +if it's case one or two, + +you change some links +and you're done. + +What's the time for that? + +AUDIENCE: Constant. + +PROFESSOR: Constant. + +So happy case, order h for sure. + +Now sad case. + +If you have two +children, what do you + +have to do after you realize +that you have two subtrees? + +AUDIENCE: Find the successor. + +PROFESSOR: OK. + +What's the running time +for finding a successor? + +AUDIENCE: Order h. + +PROFESSOR: Order h. + +Once I find the +successor, what do I do? + +Call Delete on that, +and what happens? + +It's a happy case or a sad case? + +AUDIENCE: It's a happy case. + +PROFESSOR: Happy case, +a few links get swapped, + +constant time. + +So worst case, order +h plus order h. + +Order h. + +So insertions are order +h, deletions are order h. + +AUDIENCE: The first one. + +Because the second one is +from finding the successor. + +What is the first one for? + +PROFESSOR: Finding the +node for a key in the tree. + +So if I say Delete 8, +then you have to find 8. + +If I give you the node, +then you don't have that. + +Good question. + +It's a good question. + +Thank you. + +So that's insertion. + +That's deletion. + +Let's look at the +code for Delete. + +Looks kind of long. + +So lines through 21, +happy case or sad case? + +Try to do it by +looking at the "if" + +instead of looking +at the comments. + +So lines through 21 for Delete. + +AUDIENCE: On this tree? + +Which tree, because +there are two deletes? + +PROFESSOR: Oh really? + +Sorry. + +Why do we have two deletes? + +AUDIENCE: There's BST Delete and +then there's BST Node Delete. + +PROFESSOR: So BST Delete. + +Finds the node, and then +calls Delete on the node. + +And then if the node +is a tree's root, + +then it updates the tree's root. + +So let's look at +the nodes delete. + +Oh, I see. + +I think I was looking +at the wrong one. + +Thank you. + +My Delete was much +longer than yours. + +So lines 3 through 12, +happy case or sad case? + +Look at the "if" on +line 3 and tell me, + +what case is it going for? + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: If it doesn't +have a left child + +or it doesn't have +a right child, + +is that the happy +case or the sad case? + +AUDIENCE: Happy. + +PROFESSOR: Happy case. + +So lines 4 through 12 +handle the happy case. + +Lines 14 through 16 +handle the sad case. + +Do lines 14 through +16 make sense? + +Find the successor, +then swap the keys, + +then delete that successor. + +Now, lines 4 through +11 are pretty much what + +we talked about here, except I +can't draw arrows on the board + +and instead I have to +change left and right links. + +Line 4 has to see if we're a +left child or a right child, + +and then lines 5 through 7 and +9 through 11 are pretty much + +copy paste, swap +left with right. + +And they changed the links +like we changed them here. + +Do we have any +questions on Deletes? + +AUDIENCE: So if the +successor had a right child, + +then all you do, you just do +the workaround thing where + +you just-- + +PROFESSOR: Yep. + +So the case that it +doesn't have two children. + +As long as it doesn't +have both children, + +you're in the happy case and +you can do some link swapping. + +Are you guys burned out already? + +Fair enough. + +I left a part out. + +What I left out is how +to augment a binary tree. + +So binary trees by default +can answer the question, + +what's the minimum node +in a tree in order h. + +You go all the way to the +left, you find the minimum. + +That's the minimum. + +It turns out that if you make +a node a little bit fatter, + +so if instead of storing, say, +23 in this node, I store 23, + +and I store the fact that the +minimum in my left subtree + +is 4, then it turns out that +I can answer the question + +in constant time, +what's the minimum? + +Oh gee, if you store +the minimum here, + +of course you can retrieve +it in constant time, right? + +The hard part is, how do you +handle insertions and updates + +in the same time? + +So the idea is that +if I have a node + +and I have a function here, +say the minimum of everything, + +if I have two children, +here they're 15 and 42, + +and say the minimum +in this tree is 4 + +and the minimum in this tree is. + +So if I already computed +the function for these guys, + +how do I compute the +function for this? + +AUDIENCE: [INAUDIBLE] +and compare it? + +PROFESSOR: Yep. + +Take the minimum of +these two guys, right? + +There are some special cases +if you don't have a child. + +If you don't have a left +child, then you're the minimum. + +But you write down +those special cases, + +and you can compute +this in how much time? + +AUDIENCE: Order h, right? + +PROFESSOR: What if I +already computed the answer + +for the children? + +How much time does +it take to compute + +the answer for a single node? + +AUDIENCE: Constant. + +PROFESSOR: Constant. + +OK. + +AUDIENCE: For a tree, though. + +PROFESSOR: For a +tree, it's order h. + +Yeah. + +You're getting ahead. + +You're rushing me. + +You're not letting me finish. + +AUDIENCE: Are you saying that +we store the minimum value? + +PROFESSOR: So for every-- + +AUDIENCE: Each node +has a field that + +says what the minimum +value is in that tree. + +PROFESSOR: Yep, exactly. + +So for each node, what's +the minimum in the subtree. + +So if I add a node here, +suppose I add three + +and I had my minimums, +what changed? + +This subtree changed, +this subtree changed, + +this subtree changed, and +then this subtree changed. + +So I have to update the +minimums here, here, here, here. + +Nothing else changed. + +Outside the path where +I did the Insert, + +nothing changed, so I don't +have to update anything. + +So what I do is after +the Insert, I go back up + +and I re-compute the values. + +So here, I'll have 3. + +I go back up 3, 3, 3. + +AUDIENCE: You could when +you're passing down, though. + +When you're going +down that column, + +you can just compare +it on the way down. + +You don't have to +go back up, right? + +PROFESSOR: Yep. + +So the advantage of doing +it the way I'm saying it + +is that you can have other +functions instead of minimum. + +As long as you can +compute the function + +inside the parent +in constant time + +using the function +from the children, + +it makes sense to compute the +function on the children first. + +There's an obvious function +that I can't tell you + +because that's on the Pset, +but when you see the next Pset, + +you'll see what I mean. + +So if you have a +function where you + +know the result for the children +and you can compute the result + +for the parent in constant time, +then after you do the Insert, + +you go up on the path and +you re-compute the function. + +When you delete, what do you do? + +AUDIENCE: Same thing. + +PROFESSOR: Same thing. + +If this goes away, then this +subtree changed, and then + +if there would be +something else here, + +then this subtree changed, +but nothing else changed. + +So whenever you do an Insert +or a Delete, all you have to do + +is go back up the +path to the parent + +and re-compute the function +that you're trying to compute. + +And that's tree augmentation. + +Does this make sense somewhat? + +That's it. + +So what you'll find +in lecture notes + +is a harder way of doing +it that works for minimum, + +but what I told you +works for everything. + +So don't tell people I told you +how to do this for everything. + +Sure nobody's going to know. \ No newline at end of file diff --git a/rL25BoFW1V4.txt b/rL25BoFW1V4.txt new file mode 100644 index 0000000000000000000000000000000000000000..a094a2cbe6455f4bbed7b3fa3c97d45d62c5532b --- /dev/null +++ b/rL25BoFW1V4.txt @@ -0,0 +1,6795 @@ +align:start position:0% + +my name is David Sue I'm a professor of + + align:start position:0% +my name is David Sue I'm a professor of + + + align:start position:0% +my name is David Sue I'm a professor of +urban studies and planning at MIT this + + align:start position:0% +urban studies and planning at MIT this + + + align:start position:0% +urban studies and planning at MIT this +is another installment of my class on + + align:start position:0% +is another installment of my class on + + + align:start position:0% +is another installment of my class on +Urban Energy Systems and policy thank + + align:start position:0% +Urban Energy Systems and policy thank + + + align:start position:0% +Urban Energy Systems and policy thank +you for joining me today we're going to + + align:start position:0% +you for joining me today we're going to + + + align:start position:0% +you for joining me today we're going to +give the third lecture on transportation + + align:start position:0% +give the third lecture on transportation + + + align:start position:0% +give the third lecture on transportation +and I'm going to talk about + + align:start position:0% +and I'm going to talk about + + + align:start position:0% +and I'm going to talk about +Transportation Systems in the first + + align:start position:0% +Transportation Systems in the first + + + align:start position:0% +Transportation Systems in the first +lecture we talked about Transportation + + align:start position:0% +lecture we talked about Transportation + + + align:start position:0% +lecture we talked about Transportation +Technologies personal transport + + align:start position:0% +Technologies personal transport + + + align:start position:0% +Technologies personal transport +standpoint we use that to build up our + + align:start position:0% +standpoint we use that to build up our + + + align:start position:0% +standpoint we use that to build up our +understanding of the Technologies + + align:start position:0% +understanding of the Technologies + + + align:start position:0% +understanding of the Technologies +involved in the last class I talked + + align:start position:0% +involved in the last class I talked + + + align:start position:0% +involved in the last class I talked +about uh policy analysis and how to + + align:start position:0% +about uh policy analysis and how to + + + align:start position:0% +about uh policy analysis and how to +analyze Transportation Systems we talked + + align:start position:0% +analyze Transportation Systems we talked + + + align:start position:0% +analyze Transportation Systems we talked +about it mostly on an equity basis today + + align:start position:0% +about it mostly on an equity basis today + + + align:start position:0% +about it mostly on an equity basis today +I want to talk about about an efficiency + + align:start position:0% +I want to talk about about an efficiency + + + align:start position:0% +I want to talk about about an efficiency +basis and use efficiency to talk about + + align:start position:0% +basis and use efficiency to talk about + + + align:start position:0% +basis and use efficiency to talk about +what cities can do what cities can do to + + align:start position:0% +what cities can do what cities can do to + + + align:start position:0% +what cities can do what cities can do to +affect a transportation system that is + + align:start position:0% +affect a transportation system that is + + + align:start position:0% +affect a transportation system that is +governed at the local level but also the + + align:start position:0% +governed at the local level but also the + + + align:start position:0% +governed at the local level but also the +regional state and federal level also + + align:start position:0% +regional state and federal level also + + + align:start position:0% +regional state and federal level also +so the materials for today are on the + + align:start position:0% +so the materials for today are on the + + + align:start position:0% +so the materials for today are on the +syllabus I'm going to spend most of my + + align:start position:0% +syllabus I'm going to spend most of my + + + align:start position:0% +syllabus I'm going to spend most of my +time talking about that fourth bullet + + align:start position:0% +time talking about that fourth bullet + + + align:start position:0% +time talking about that fourth bullet +point which was not a reading I signed + + align:start position:0% +point which was not a reading I signed + + + align:start position:0% +point which was not a reading I signed +for this class it's a report by + + align:start position:0% +for this class it's a report by + + + align:start position:0% +for this class it's a report by +Cambridge systematics and the Urban Land + + align:start position:0% +Cambridge systematics and the Urban Land + + + align:start position:0% +Cambridge systematics and the Urban Land +Institute it's titled moving cooler and + + align:start position:0% +Institute it's titled moving cooler and + + + align:start position:0% +Institute it's titled moving cooler and +Analysis of Transportation strategies + + align:start position:0% +Analysis of Transportation strategies + + + align:start position:0% +Analysis of Transportation strategies +for reducing greenhouse gas missions + + align:start position:0% +for reducing greenhouse gas missions + + + align:start position:0% +for reducing greenhouse gas missions +I'll tell you a little bit why I didn't + + align:start position:0% +I'll tell you a little bit why I didn't + + + align:start position:0% +I'll tell you a little bit why I didn't +assign it as a reading but at the same + + align:start position:0% +assign it as a reading but at the same + + + align:start position:0% +assign it as a reading but at the same +time I'll spend most of this lecture + + align:start position:0% +time I'll spend most of this lecture + + + align:start position:0% +time I'll spend most of this lecture +talking about it so you won't + + align:start position:0% +talking about it so you won't + + + align:start position:0% +talking about it so you won't +necessarily find these um uh this + + align:start position:0% +necessarily find these um uh this + + + align:start position:0% +necessarily find these um uh this +lecture or it's not part of our sign + + align:start position:0% +lecture or it's not part of our sign + + + align:start position:0% +lecture or it's not part of our sign +reading but I encourage you to listen to + + align:start position:0% +reading but I encourage you to listen to + + + align:start position:0% +reading but I encourage you to listen to +the video lecture because there's things + + align:start position:0% +the video lecture because there's things + + + align:start position:0% +the video lecture because there's things +I want to pull out of that lecture for + + align:start position:0% +I want to pull out of that lecture for + + + align:start position:0% +I want to pull out of that lecture for +class discussion on + + align:start position:0% +class discussion on + + + align:start position:0% +class discussion on +Thursday just to remind you what can + + align:start position:0% +Thursday just to remind you what can + + + align:start position:0% +Thursday just to remind you what can +cities do why is that an important + + align:start position:0% +cities do why is that an important + + + align:start position:0% +cities do why is that an important +question I'll remind you that we're + + align:start position:0% +question I'll remind you that we're + + + align:start position:0% +question I'll remind you that we're +focusing on cities because of population + + align:start position:0% +focusing on cities because of population + + + align:start position:0% +focusing on cities because of population +majority of human beings globally and in + + align:start position:0% +majority of human beings globally and in + + + align:start position:0% +majority of human beings globally and in +almost all countries or almost all + + align:start position:0% +almost all countries or almost all + + + align:start position:0% +almost all countries or almost all +regions of the world live in cities with + + align:start position:0% +regions of the world live in cities with + + + align:start position:0% +regions of the world live in cities with +that population we have a very high + + align:start position:0% +that population we have a very high + + + align:start position:0% +that population we have a very high +degree of economic activity and of + + align:start position:0% +degree of economic activity and of + + + align:start position:0% +degree of economic activity and of +course cities are centers of consumption + + align:start position:0% +course cities are centers of consumption + + + align:start position:0% +course cities are centers of consumption +while we do have cities that produce + + align:start position:0% +while we do have cities that produce + + + align:start position:0% +while we do have cities that produce +energy and materials and goods in + + align:start position:0% +energy and materials and goods in + + + align:start position:0% +energy and materials and goods in +general in urban areas we consume things + + align:start position:0% +general in urban areas we consume things + + + align:start position:0% +general in urban areas we consume things +from the outside like food like + + align:start position:0% +from the outside like food like + + + align:start position:0% +from the outside like food like +materials like fuels and so our cities + + align:start position:0% +materials like fuels and so our cities + + + align:start position:0% +materials like fuels and so our cities +are centers of consumption not + + align:start position:0% +are centers of consumption not + + + align:start position:0% +are centers of consumption not +production and so we have to think about + + align:start position:0% +production and so we have to think about + + + align:start position:0% +production and so we have to think about +the role of cities in reducing + + align:start position:0% +the role of cities in reducing + + + align:start position:0% +the role of cities in reducing +consumption to achieve our + + align:start position:0% +consumption to achieve our + + + align:start position:0% +consumption to achieve our +decarbonization goals this raises + + align:start position:0% +decarbonization goals this raises + + + align:start position:0% +decarbonization goals this raises +questions about how we are going to make + + align:start position:0% +questions about how we are going to make + + + align:start position:0% +questions about how we are going to make +the necessary changes in cities we know + + align:start position:0% +the necessary changes in cities we know + + + align:start position:0% +the necessary changes in cities we know +that cities are composed of land use and + + align:start position:0% +that cities are composed of land use and + + + align:start position:0% +that cities are composed of land use and +built environment I've just made the + + align:start position:0% +built environment I've just made the + + + align:start position:0% +built environment I've just made the +point to you that cities are connected + + align:start position:0% +point to you that cities are connected + + + align:start position:0% +point to you that cities are connected +to outside areas basically all outside + + align:start position:0% +to outside areas basically all outside + + + align:start position:0% +to outside areas basically all outside +areas we import materials foods and fuel + + align:start position:0% +areas we import materials foods and fuel + + + align:start position:0% +areas we import materials foods and fuel +into cities so how do we think about + + align:start position:0% +into cities so how do we think about + + + align:start position:0% +into cities so how do we think about +changing cities or what can cities do in + + align:start position:0% +changing cities or what can cities do in + + + align:start position:0% +changing cities or what can cities do in +a larger transportation + + align:start position:0% +a larger transportation + + + align:start position:0% +a larger transportation +system and we also know that while urban + + align:start position:0% +system and we also know that while urban + + + align:start position:0% +system and we also know that while urban +life seems very fast-paced we also know + + align:start position:0% +life seems very fast-paced we also know + + + align:start position:0% +life seems very fast-paced we also know +that buildings and the shape of cities + + align:start position:0% +that buildings and the shape of cities + + + align:start position:0% +that buildings and the shape of cities +are relatively long lived durable and + + align:start position:0% +are relatively long lived durable and + + + align:start position:0% +are relatively long lived durable and +seemingly slow to change so the question + + align:start position:0% +seemingly slow to change so the question + + + align:start position:0% +seemingly slow to change so the question +is can we make changes as the urban + + align:start position:0% +is can we make changes as the urban + + + align:start position:0% +is can we make changes as the urban +scale fast enough or broadly enough + + align:start position:0% +scale fast enough or broadly enough + + + align:start position:0% +scale fast enough or broadly enough +who's going to do it and how are we + + align:start position:0% +who's going to do it and how are we + + + align:start position:0% +who's going to do it and how are we +going to make these changes and of + + align:start position:0% +going to make these changes and of + + + align:start position:0% +going to make these changes and of +course from efficiency perspective we + + align:start position:0% +course from efficiency perspective we + + + align:start position:0% +course from efficiency perspective we +have to ask what should we do first to + + align:start position:0% +have to ask what should we do first to + + + align:start position:0% +have to ask what should we do first to +try to achieve better enviral + + align:start position:0% +try to achieve better enviral + + + align:start position:0% +try to achieve better enviral +sustainability or + + align:start position:0% +sustainability or + + + align:start position:0% +sustainability or +decarbonization and I just want to + + align:start position:0% +decarbonization and I just want to + + + align:start position:0% +decarbonization and I just want to +emphasize that a lot of the + + align:start position:0% +emphasize that a lot of the + + + align:start position:0% +emphasize that a lot of the +characteristics we are concerned about + + align:start position:0% +characteristics we are concerned about + + + align:start position:0% +characteristics we are concerned about +cities or why we think cities are hard + + align:start position:0% +cities or why we think cities are hard + + + align:start position:0% +cities or why we think cities are hard +to change quickly are similar + + align:start position:0% +to change quickly are similar + + + align:start position:0% +to change quickly are similar +characteristics to infrastructure to put + + align:start position:0% +characteristics to infrastructure to put + + + align:start position:0% +characteristics to infrastructure to put +it simply infrastructure is really big + + align:start position:0% +it simply infrastructure is really big + + + align:start position:0% +it simply infrastructure is really big +it is also longlived durable and + + align:start position:0% +it is also longlived durable and + + + align:start position:0% +it is also longlived durable and +seemingly slow to change infrastructure + + align:start position:0% +seemingly slow to change infrastructure + + + align:start position:0% +seemingly slow to change infrastructure +is really expensive it's composed of a + + align:start position:0% +is really expensive it's composed of a + + + align:start position:0% +is really expensive it's composed of a +lot of assets and investment it's often + + align:start position:0% +lot of assets and investment it's often + + + align:start position:0% +lot of assets and investment it's often +debt financed over long periods of + + align:start position:0% +debt financed over long periods of + + + align:start position:0% +debt financed over long periods of +time it's debt finan over long periods + + align:start position:0% +time it's debt finan over long periods + + + align:start position:0% +time it's debt finan over long periods +of time because infrastructure is + + align:start position:0% +of time because infrastructure is + + + align:start position:0% +of time because infrastructure is +assumed to operate in a fairly + + align:start position:0% +assumed to operate in a fairly + + + align:start position:0% +assumed to operate in a fairly +continuous basis we move large volumes + + align:start position:0% +continuous basis we move large volumes + + + align:start position:0% +continuous basis we move large volumes +of things we have continuous operations + + align:start position:0% +of things we have continuous operations + + + align:start position:0% +of things we have continuous operations +and they connect to Global Systems and + + align:start position:0% +and they connect to Global Systems and + + + align:start position:0% +and they connect to Global Systems and +in other words our supply chains that we + + align:start position:0% +in other words our supply chains that we + + + align:start position:0% +in other words our supply chains that we +have seen stressed over the last couple + + align:start position:0% +have seen stressed over the last couple + + + align:start position:0% +have seen stressed over the last couple +years we know that infrastructure + + align:start position:0% +years we know that infrastructure + + + align:start position:0% +years we know that infrastructure +physically has very large Footprints and + + align:start position:0% +physically has very large Footprints and + + + align:start position:0% +physically has very large Footprints and +areas and impact and we know that we + + align:start position:0% +areas and impact and we know that we + + + align:start position:0% +areas and impact and we know that we +have environmental justice concerns the + + align:start position:0% +have environmental justice concerns the + + + align:start position:0% +have environmental justice concerns the +Buller article I think quite + + align:start position:0% +Buller article I think quite + + + align:start position:0% +Buller article I think quite +convincingly argues that infrastructure + + align:start position:0% +convincingly argues that infrastructure + + + align:start position:0% +convincingly argues that infrastructure +such as transportation is often cited + + align:start position:0% +such as transportation is often cited + + + align:start position:0% +such as transportation is often cited +apologies for that misspelling there + + align:start position:0% +apologies for that misspelling there + + + align:start position:0% +apologies for that misspelling there +cited near poor and minority communities + + align:start position:0% +cited near poor and minority communities + + + align:start position:0% +cited near poor and minority communities +the article examines why but also + + align:start position:0% +the article examines why but also + + + align:start position:0% +the article examines why but also +examines why the environmental burdens + + align:start position:0% +examines why the environmental burdens + + + align:start position:0% +examines why the environmental burdens +of these infrastructures are often + + align:start position:0% +of these infrastructures are often + + + align:start position:0% +of these infrastructures are often +nearly quite often cited your poor and + + align:start position:0% +nearly quite often cited your poor and + + + align:start position:0% +nearly quite often cited your poor and +minority + + align:start position:0% +minority + + + align:start position:0% +minority +communities one last thing I want to + + align:start position:0% +communities one last thing I want to + + + align:start position:0% +communities one last thing I want to +talk about before we talk about + + align:start position:0% +talk about before we talk about + + + align:start position:0% +talk about before we talk about +analyzing systems and understanding what + + align:start position:0% +analyzing systems and understanding what + + + align:start position:0% +analyzing systems and understanding what +cities can do is the concept of energy + + align:start position:0% +cities can do is the concept of energy + + + align:start position:0% +cities can do is the concept of energy +density we know that energy can be + + align:start position:0% +density we know that energy can be + + + align:start position:0% +density we know that energy can be +measured in terms of the sheer amount of + + align:start position:0% +measured in terms of the sheer amount of + + + align:start position:0% +measured in terms of the sheer amount of +energy but more useful for certain kinds + + align:start position:0% +energy but more useful for certain kinds + + + align:start position:0% +energy but more useful for certain kinds +of systems it's good to analyze certain + + align:start position:0% +of systems it's good to analyze certain + + + align:start position:0% +of systems it's good to analyze certain +metrics so in terms of weight we might + + align:start position:0% +metrics so in terms of weight we might + + + align:start position:0% +metrics so in terms of weight we might +think about how much energy certain + + align:start position:0% +think about how much energy certain + + + align:start position:0% +think about how much energy certain +Technologies store like kilowatt hours + + align:start position:0% +Technologies store like kilowatt hours + + + align:start position:0% +Technologies store like kilowatt hours +per kilogram critical applications are + + align:start position:0% +per kilogram critical applications are + + + align:start position:0% +per kilogram critical applications are +planes cars and ebikes because we know + + align:start position:0% +planes cars and ebikes because we know + + + align:start position:0% +planes cars and ebikes because we know +the batteries themselves or the fuel + + align:start position:0% +the batteries themselves or the fuel + + + align:start position:0% +the batteries themselves or the fuel +tank is a really large portion of the + + align:start position:0% +tank is a really large portion of the + + + align:start position:0% +tank is a really large portion of the +vehicle weight itself it's hard to keep + + align:start position:0% +vehicle weight itself it's hard to keep + + + align:start position:0% +vehicle weight itself it's hard to keep +planes in the air you know a heavy car + + align:start position:0% +planes in the air you know a heavy car + + + align:start position:0% +planes in the air you know a heavy car +or heavy bicycle doesn't perform + + align:start position:0% +or heavy bicycle doesn't perform + + + align:start position:0% +or heavy bicycle doesn't perform +similarly to a lighter bicycle or + + align:start position:0% +similarly to a lighter bicycle or + + + align:start position:0% +similarly to a lighter bicycle or +lighter car we can also measure things + + align:start position:0% +lighter car we can also measure things + + + align:start position:0% +lighter car we can also measure things +in terms of energy required to ship a + + align:start position:0% +in terms of energy required to ship a + + + align:start position:0% +in terms of energy required to ship a +certain amount of weight kilowatt hours + + align:start position:0% +certain amount of weight kilowatt hours + + + align:start position:0% +certain amount of weight kilowatt hours +per ton that matters for planes but also + + align:start position:0% +per ton that matters for planes but also + + + align:start position:0% +per ton that matters for planes but also +ships trucks and trains we can measure + + align:start position:0% +ships trucks and trains we can measure + + + align:start position:0% +ships trucks and trains we can measure +energy in terms of kilowatt hours per + + align:start position:0% +energy in terms of kilowatt hours per + + + align:start position:0% +energy in terms of kilowatt hours per +liter of volume terms of the fuel tank + + align:start position:0% +liter of volume terms of the fuel tank + + + align:start position:0% +liter of volume terms of the fuel tank +planes cars trucks you know that the + + align:start position:0% +planes cars trucks you know that the + + + align:start position:0% +planes cars trucks you know that the +fuel tank is not a small portion of the + + align:start position:0% +fuel tank is not a small portion of the + + + align:start position:0% +fuel tank is not a small portion of the +vehicle volume and of course we can + + align:start position:0% +vehicle volume and of course we can + + + align:start position:0% +vehicle volume and of course we can +measure how much Freight volume we can + + align:start position:0% +measure how much Freight volume we can + + + align:start position:0% +measure how much Freight volume we can +move for large amounts of Commodities in + + align:start position:0% +move for large amounts of Commodities in + + + align:start position:0% +move for large amounts of Commodities in +Planes ships trucks and trains we can + + align:start position:0% +Planes ships trucks and trains we can + + + align:start position:0% +Planes ships trucks and trains we can +measure energy in terms of land area for + + align:start position:0% +measure energy in terms of land area for + + + align:start position:0% +measure energy in terms of land area for +example the kilowatt hours produced per + + align:start position:0% +example the kilowatt hours produced per + + + align:start position:0% +example the kilowatt hours produced per +acre let's say biomass we we're going to + + align:start position:0% +acre let's say biomass we we're going to + + + align:start position:0% +acre let's say biomass we we're going to +need biomass to produce liquid fuels and + + align:start position:0% +need biomass to produce liquid fuels and + + + align:start position:0% +need biomass to produce liquid fuels and +hydrogen or kilowatt hours per acre to + + align:start position:0% +hydrogen or kilowatt hours per acre to + + + align:start position:0% +hydrogen or kilowatt hours per acre to +generate solar and wind produce + + align:start position:0% +generate solar and wind produce + + + align:start position:0% +generate solar and wind produce +electricity and finally there's the + + align:start position:0% +electricity and finally there's the + + + align:start position:0% +electricity and finally there's the +energy density of energy dens density + + align:start position:0% +energy density of energy dens density + + + align:start position:0% +energy density of energy dens density +per per money or kilowatt hours per + + align:start position:0% +per per money or kilowatt hours per + + + align:start position:0% +per per money or kilowatt hours per +dollar we obviously need to know that + + align:start position:0% +dollar we obviously need to know that + + + align:start position:0% +dollar we obviously need to know that +for pretty much everything to deploy + + align:start position:0% +for pretty much everything to deploy + + + align:start position:0% +for pretty much everything to deploy +different + + align:start position:0% +different + + + align:start position:0% +different +Technologies this bring things to the + + align:start position:0% +Technologies this bring things to the + + + align:start position:0% +Technologies this bring things to the +moving cooler strategies report it was + + align:start position:0% +moving cooler strategies report it was + + + align:start position:0% +moving cooler strategies report it was +written in 2009 it was written by this + + align:start position:0% +written in 2009 it was written by this + + + align:start position:0% +written in 2009 it was written by this +entire group of different agencies and + + align:start position:0% +entire group of different agencies and + + + align:start position:0% +entire group of different agencies and +environmental groups ranging from the + + align:start position:0% +environmental groups ranging from the + + + align:start position:0% +environmental groups ranging from the +American public transportation + + align:start position:0% +American public transportation + + + align:start position:0% +American public transportation +Association the intelligent + + align:start position:0% +Association the intelligent + + + align:start position:0% +Association the intelligent +Transportation Society of America and + + align:start position:0% +Transportation Society of America and + + + align:start position:0% +Transportation Society of America and +the Shell Oil Company to the + + align:start position:0% +the Shell Oil Company to the + + + align:start position:0% +the Shell Oil Company to the +environmental defense fund the Federal + + align:start position:0% +environmental defense fund the Federal + + + align:start position:0% +environmental defense fund the Federal +Highway Administration Federal Transit + + align:start position:0% +Highway Administration Federal Transit + + + align:start position:0% +Highway Administration Federal Transit +Administration and the US envir + + align:start position:0% +Administration and the US envir + + + align:start position:0% +Administration and the US envir +Protection Agency and a few other groups + + align:start position:0% +Protection Agency and a few other groups + + + align:start position:0% +Protection Agency and a few other groups +and agencies the key point is that this + + align:start position:0% +and agencies the key point is that this + + + align:start position:0% +and agencies the key point is that this +is actually a fairly unusual report it + + align:start position:0% +is actually a fairly unusual report it + + + align:start position:0% +is actually a fairly unusual report it +was meant to bring together a lot of + + align:start position:0% +was meant to bring together a lot of + + + align:start position:0% +was meant to bring together a lot of +disperate groups to think about how to + + align:start position:0% +disperate groups to think about how to + + + align:start position:0% +disperate groups to think about how to +reduce greenhous gas emissions in the + + align:start position:0% +reduce greenhous gas emissions in the + + + align:start position:0% +reduce greenhous gas emissions in the +transportation system which is very much + + align:start position:0% +transportation system which is very much + + + align:start position:0% +transportation system which is very much +tied up to tied up with our urban life + + align:start position:0% +tied up to tied up with our urban life + + + align:start position:0% +tied up to tied up with our urban life +which is why the Urban Land Institute + + align:start position:0% +which is why the Urban Land Institute + + + align:start position:0% +which is why the Urban Land Institute +helped convene this report and + + align:start position:0% +helped convene this report and + + + align:start position:0% +helped convene this report and +workshop and it's important to note why + + align:start position:0% +workshop and it's important to note why + + + align:start position:0% +workshop and it's important to note why +I guess I didn't assign it as weing this + + align:start position:0% +I guess I didn't assign it as weing this + + + align:start position:0% +I guess I didn't assign it as weing this +year I've assigned it in previous years + + align:start position:0% +year I've assigned it in previous years + + + align:start position:0% +year I've assigned it in previous years +it's a 2009 report and honestly it gets + + align:start position:0% +it's a 2009 report and honestly it gets + + + align:start position:0% +it's a 2009 report and honestly it gets +very technical in places so I decided + + align:start position:0% +very technical in places so I decided + + + align:start position:0% +very technical in places so I decided +not to assign it this year but I want to + + align:start position:0% +not to assign it this year but I want to + + + align:start position:0% +not to assign it this year but I want to +highlight some of the findings in this + + align:start position:0% +highlight some of the findings in this + + + align:start position:0% +highlight some of the findings in this +video lecture it's important to note + + align:start position:0% +video lecture it's important to note + + + align:start position:0% +video lecture it's important to note +what this report does have that makes it + + align:start position:0% +what this report does have that makes it + + + align:start position:0% +what this report does have that makes it +a really good report it does have a + + align:start position:0% +a really good report it does have a + + + align:start position:0% +a really good report it does have a +consideration of telor or less work days + + align:start position:0% +consideration of telor or less work days + + + align:start position:0% +consideration of telor or less work days +at the office now we know after two + + align:start position:0% +at the office now we know after two + + + align:start position:0% +at the office now we know after two +years of Zoom this is possible and + + align:start position:0% +years of Zoom this is possible and + + + align:start position:0% +years of Zoom this is possible and +perhaps even preferable now it does + + align:start position:0% +perhaps even preferable now it does + + + align:start position:0% +perhaps even preferable now it does +include changes in vehicle technology + + align:start position:0% +include changes in vehicle technology + + + align:start position:0% +include changes in vehicle technology +fuel technology travel activity vehicle + + align:start position:0% +fuel technology travel activity vehicle + + + align:start position:0% +fuel technology travel activity vehicle +system operations and crucially codes + + align:start position:0% +system operations and crucially codes + + + align:start position:0% +system operations and crucially codes +all different modes of transportation + + align:start position:0% +all different modes of transportation + + + align:start position:0% +all different modes of transportation +passenger modes Transit modes Freight + + align:start position:0% +passenger modes Transit modes Freight + + + align:start position:0% +passenger modes Transit modes Freight +modes shipping modes and Aviation modes + + align:start position:0% +modes shipping modes and Aviation modes + + + align:start position:0% +modes shipping modes and Aviation modes +what it doesn't have it's a 2009 report + + align:start position:0% +what it doesn't have it's a 2009 report + + + align:start position:0% +what it doesn't have it's a 2009 report +but it doesn't actually have shared + + align:start position:0% +but it doesn't actually have shared + + + align:start position:0% +but it doesn't actually have shared +Vehicles zip car was the business model + + align:start position:0% +Vehicles zip car was the business model + + + align:start position:0% +Vehicles zip car was the business model +where you could share vehicles in your + + align:start position:0% +where you could share vehicles in your + + + align:start position:0% +where you could share vehicles in your +neighborhood I think it's since been + + align:start position:0% +neighborhood I think it's since been + + + align:start position:0% +neighborhood I think it's since been +bought by Herz and I'm not sure if Herz + + align:start position:0% +bought by Herz and I'm not sure if Herz + + + align:start position:0% +bought by Herz and I'm not sure if Herz +still offers the vehicle based shared + + align:start position:0% +still offers the vehicle based shared + + + align:start position:0% +still offers the vehicle based shared +vehicles uh the report only written 2009 + + align:start position:0% +vehicles uh the report only written 2009 + + + align:start position:0% +vehicles uh the report only written 2009 +which is the same year that Uber starts + + align:start position:0% +which is the same year that Uber starts + + + align:start position:0% +which is the same year that Uber starts +ride sharing and lift follows three + + align:start position:0% +ride sharing and lift follows three + + + align:start position:0% +ride sharing and lift follows three +years later it doesn't include + + align:start position:0% +years later it doesn't include + + + align:start position:0% +years later it doesn't include +autonomous vehicles they arguably + + align:start position:0% +autonomous vehicles they arguably + + + align:start position:0% +autonomous vehicles they arguably +autonomous vehicles may be a few more + + align:start position:0% +autonomous vehicles may be a few more + + + align:start position:0% +autonomous vehicles may be a few more +years off than we think they are but it + + align:start position:0% +years off than we think they are but it + + + align:start position:0% +years off than we think they are but it +also doesn't include the fact that + + align:start position:0% +also doesn't include the fact that + + + align:start position:0% +also doesn't include the fact that +electric vehicle costs have greatly + + align:start position:0% +electric vehicle costs have greatly + + + align:start position:0% +electric vehicle costs have greatly +decreased and we're seeing increases in + + align:start position:0% +decreased and we're seeing increases in + + + align:start position:0% +decreased and we're seeing increases in +micro Mobility like scooters electric + + align:start position:0% +micro Mobility like scooters electric + + + align:start position:0% +micro Mobility like scooters electric +bikes it doesn't include bike sharing + + align:start position:0% +bikes it doesn't include bike sharing + + + align:start position:0% +bikes it doesn't include bike sharing +which was started in Amsterdam in + + align:start position:0% +which was started in Amsterdam in + + + align:start position:0% +which was started in Amsterdam in +1965 was deployed at Portland Oregon in + + align:start position:0% +1965 was deployed at Portland Oregon in + + + align:start position:0% +1965 was deployed at Portland Oregon in +1995 and dockless bikes started being + + align:start position:0% +1995 and dockless bikes started being + + + align:start position:0% +1995 and dockless bikes started being +deployed in + + align:start position:0% +deployed in + + + align:start position:0% +deployed in +1998 so this report has good aspect also + + align:start position:0% +1998 so this report has good aspect also + + + align:start position:0% +1998 so this report has good aspect also +lacks other + + align:start position:0% +lacks other + + + align:start position:0% +lacks other +aspects it also considers performance + + align:start position:0% +aspects it also considers performance + + + align:start position:0% +aspects it also considers performance +outcomes it does look at greenhouse gas + + align:start position:0% +outcomes it does look at greenhouse gas + + + align:start position:0% +outcomes it does look at greenhouse gas +reductions it looks at the + + align:start position:0% +reductions it looks at the + + + align:start position:0% +reductions it looks at the +implementation costs which is important + + align:start position:0% +implementation costs which is important + + + align:start position:0% +implementation costs which is important +it looks at the change in vehicle costs + + align:start position:0% +it looks at the change in vehicle costs + + + align:start position:0% +it looks at the change in vehicle costs +required to achieve these performance + + align:start position:0% +required to achieve these performance + + + align:start position:0% +required to achieve these performance +outcomes and it looks at Equity effects + + align:start position:0% +outcomes and it looks at Equity effects + + + align:start position:0% +outcomes and it looks at Equity effects +it doesn't look necessarily look at + + align:start position:0% +it doesn't look necessarily look at + + + align:start position:0% +it doesn't look necessarily look at +travel times one of the reasons why we + + align:start position:0% +travel times one of the reasons why we + + + align:start position:0% +travel times one of the reasons why we +care about Transportation like in the + + align:start position:0% +care about Transportation like in the + + + align:start position:0% +care about Transportation like in the +graph before we care about how fast + + align:start position:0% +graph before we care about how fast + + + align:start position:0% +graph before we care about how fast +these modes are even if they use + + align:start position:0% +these modes are even if they use + + + align:start position:0% +these modes are even if they use +different amounts of energy it does not + + align:start position:0% +different amounts of energy it does not + + + align:start position:0% +different amounts of energy it does not +I think look at what positive which is + + align:start position:0% +I think look at what positive which is + + + align:start position:0% +I think look at what positive which is +if we were expand options reduce + + align:start position:0% +if we were expand options reduce + + + align:start position:0% +if we were expand options reduce +congestions or enable greater + + align:start position:0% +congestions or enable greater + + + align:start position:0% +congestions or enable greater +accessibility it doesn't look at + + align:start position:0% +accessibility it doesn't look at + + + align:start position:0% +accessibility it doesn't look at +improving safety which is something we + + align:start position:0% +improving safety which is something we + + + align:start position:0% +improving safety which is something we +care about in our let's say our vision + + align:start position:0% +care about in our let's say our vision + + + align:start position:0% +care about in our let's say our vision +zero plans and it does does not include + + align:start position:0% +zero plans and it does does not include + + + align:start position:0% +zero plans and it does does not include +improvements in livability equity + + align:start position:0% +improvements in livability equity + + + align:start position:0% +improvements in livability equity +improve local market quality and enhance + + align:start position:0% +improve local market quality and enhance + + + align:start position:0% +improve local market quality and enhance +public health for example I don't think + + align:start position:0% +public health for example I don't think + + + align:start position:0% +public health for example I don't think +it considers the impacts of air + + align:start position:0% +it considers the impacts of air + + + align:start position:0% +it considers the impacts of air +pollution on asthma or chronic pulmonary + + align:start position:0% +pollution on asthma or chronic pulmonary + + + align:start position:0% +pollution on asthma or chronic pulmonary +heart disease which we know are really + + align:start position:0% +heart disease which we know are really + + + align:start position:0% +heart disease which we know are really +big impacts of our transportation system + + align:start position:0% +big impacts of our transportation system + + + align:start position:0% +big impacts of our transportation system +now + + align:start position:0% +now + + + align:start position:0% +now +but the most important thing about this + + align:start position:0% +but the most important thing about this + + + align:start position:0% +but the most important thing about this +from a policy perspective for cities is + + align:start position:0% +from a policy perspective for cities is + + + align:start position:0% +from a policy perspective for cities is +that it does include many different + + align:start position:0% +that it does include many different + + + align:start position:0% +that it does include many different +strategies that cities can Implement in + + align:start position:0% +strategies that cities can Implement in + + + align:start position:0% +strategies that cities can Implement in +various ways it includes many kinds of + + align:start position:0% +various ways it includes many kinds of + + + align:start position:0% +various ways it includes many kinds of +pricing and taxes ranging from parking + + align:start position:0% +pricing and taxes ranging from parking + + + align:start position:0% +pricing and taxes ranging from parking +pricing to Road or congestion pricing it + + align:start position:0% +pricing to Road or congestion pricing it + + + align:start position:0% +pricing to Road or congestion pricing it +includes land use and smart growth + + align:start position:0% +includes land use and smart growth + + + align:start position:0% +includes land use and smart growth +policies includes non-motorized + + align:start position:0% +policies includes non-motorized + + + align:start position:0% +policies includes non-motorized +Transportation includes improvements to + + align:start position:0% +Transportation includes improvements to + + + align:start position:0% +Transportation includes improvements to +public transportation includes ride + + align:start position:0% +public transportation includes ride + + + align:start position:0% +public transportation includes ride +sharing and car sharing and other + + align:start position:0% +sharing and car sharing and other + + + align:start position:0% +sharing and car sharing and other +community strategies I think they're + + align:start position:0% +community strategies I think they're + + + align:start position:0% +community strategies I think they're +referring mostly to car pooling not to + + align:start position:0% +referring mostly to car pooling not to + + + align:start position:0% +referring mostly to car pooling not to +ride hailing services but you can + + align:start position:0% +ride hailing services but you can + + + align:start position:0% +ride hailing services but you can +imagine that some of those results might + + align:start position:0% +imagine that some of those results might + + + align:start position:0% +imagine that some of those results might +extend to ride hailing Services includes + + align:start position:0% +extend to ride hailing Services includes + + + align:start position:0% +extend to ride hailing Services includes +regulatory strategies operational and + + align:start position:0% +regulatory strategies operational and + + + align:start position:0% +regulatory strategies operational and +intelligent Transportation strategies + + align:start position:0% +intelligent Transportation strategies + + + align:start position:0% +intelligent Transportation strategies +things that are probably have expanded + + align:start position:0% +things that are probably have expanded + + + align:start position:0% +things that are probably have expanded +in the last 13 years since the report + + align:start position:0% +in the last 13 years since the report + + + align:start position:0% +in the last 13 years since the report +was written because the growth of + + align:start position:0% +was written because the growth of + + + align:start position:0% +was written because the growth of +telecomunications infrastructure I just + + align:start position:0% +telecomunications infrastructure I just + + + align:start position:0% +telecomunications infrastructure I just +to put this in perspective this report + + align:start position:0% +to put this in perspective this report + + + align:start position:0% +to put this in perspective this report +was written one year after the iPhone + + align:start position:0% +was written one year after the iPhone + + + align:start position:0% +was written one year after the iPhone +was introduced and yet we probably all + + align:start position:0% +was introduced and yet we probably all + + + align:start position:0% +was introduced and yet we probably all +use various mapping applications on our + + align:start position:0% +use various mapping applications on our + + + align:start position:0% +use various mapping applications on our +phones every day now to figure out the + + align:start position:0% +phones every day now to figure out the + + + align:start position:0% +phones every day now to figure out the +quickest way to a certain place or to + + align:start position:0% +quickest way to a certain place or to + + + align:start position:0% +quickest way to a certain place or to +work and finally capacity expansion + + align:start position:0% +work and finally capacity expansion + + + align:start position:0% +work and finally capacity expansion +bottleneck relief multimodal great + + align:start position:0% +bottleneck relief multimodal great + + + align:start position:0% +bottleneck relief multimodal great +sector strategies I would argue are + + align:start position:0% +sector strategies I would argue are + + + align:start position:0% +sector strategies I would argue are +things that as urban planners we don't + + align:start position:0% +things that as urban planners we don't + + + align:start position:0% +things that as urban planners we don't +look at very + + align:start position:0% +look at very + + + align:start position:0% +look at very +often it also considers expanded uh + + align:start position:0% +often it also considers expanded uh + + + align:start position:0% +often it also considers expanded uh +different levels of deployment expanded + + align:start position:0% +different levels of deployment expanded + + + align:start position:0% +different levels of deployment expanded +hear practice focuses mostly on major + + align:start position:0% +hear practice focuses mostly on major + + + align:start position:0% +hear practice focuses mostly on major +Metro areas an aggressive level of + + align:start position:0% +Metro areas an aggressive level of + + + align:start position:0% +Metro areas an aggressive level of +deployment does this sooner and more + + align:start position:0% +deployment does this sooner and more + + + align:start position:0% +deployment does this sooner and more +broadly geographically deployed through + + align:start position:0% +broadly geographically deployed through + + + align:start position:0% +broadly geographically deployed through +smaller or Med mediumsized metral areas + + align:start position:0% +smaller or Med mediumsized metral areas + + + align:start position:0% +smaller or Med mediumsized metral areas +and a maximum effort assumes we have a + + align:start position:0% +and a maximum effort assumes we have a + + + align:start position:0% +and a maximum effort assumes we have a +maximum National regional and local + + align:start position:0% +maximum National regional and local + + + align:start position:0% +maximum National regional and local +focus on trying to reduce green gas + + align:start position:0% +focus on trying to reduce green gas + + + align:start position:0% +focus on trying to reduce green gas +emissions finally they they categorize + + align:start position:0% +emissions finally they they categorize + + + align:start position:0% +emissions finally they they categorize +these things into two different strategy + + align:start position:0% +these things into two different strategy + + + align:start position:0% +these things into two different strategy +bundles they look at near-term early + + align:start position:0% +bundles they look at near-term early + + + align:start position:0% +bundles they look at near-term early +results they look at long-term maximum + + align:start position:0% +results they look at long-term maximum + + + align:start position:0% +results they look at long-term maximum +results they look at land use Transit + + align:start position:0% +results they look at land use Transit + + + align:start position:0% +results they look at land use Transit +and a non-motorized bundle and they look + + align:start position:0% +and a non-motorized bundle and they look + + + align:start position:0% +and a non-motorized bundle and they look +at a system driver a system and Driver + + align:start position:0% +at a system driver a system and Driver + + + align:start position:0% +at a system driver a system and Driver +efficiency bundle a bundle that improves + + align:start position:0% +efficiency bundle a bundle that improves + + + align:start position:0% +efficiency bundle a bundle that improves +Transportation facilities themselves and + + align:start position:0% +Transportation facilities themselves and + + + align:start position:0% +Transportation facilities themselves and +finally and importantly a lowcost Bund + + align:start position:0% +finally and importantly a lowcost Bund + + + align:start position:0% +finally and importantly a lowcost Bund +looking at what are the lowest cost + + align:start position:0% +looking at what are the lowest cost + + + align:start position:0% +looking at what are the lowest cost +things we can do to reduce greenhouse + + align:start position:0% +things we can do to reduce greenhouse + + + align:start position:0% +things we can do to reduce greenhouse +gas + + align:start position:0% +gas + + + align:start position:0% +gas +emissions so if you look at some of the + + align:start position:0% +emissions so if you look at some of the + + + align:start position:0% +emissions so if you look at some of the +results they measure things against the + + align:start position:0% +results they measure things against the + + + align:start position:0% +results they measure things against the +study Baseline they do a sensitivity + + align:start position:0% +study Baseline they do a sensitivity + + + align:start position:0% +study Baseline they do a sensitivity +analysis according to different kinds of + + align:start position:0% +analysis according to different kinds of + + + align:start position:0% +analysis according to different kinds of +assumptions around fuel prices vehicle + + align:start position:0% +assumptions around fuel prices vehicle + + + align:start position:0% +assumptions around fuel prices vehicle +miles traveled Obama administration + + align:start position:0% +miles traveled Obama administration + + + align:start position:0% +miles traveled Obama administration +proposal at the time crucially though + + align:start position:0% +proposal at the time crucially though + + + align:start position:0% +proposal at the time crucially though +and this is something that always found + + align:start position:0% +and this is something that always found + + + align:start position:0% +and this is something that always found +a little depressing when I taught this + + align:start position:0% +a little depressing when I taught this + + + align:start position:0% +a little depressing when I taught this +report in class is that if you look at + + align:start position:0% +report in class is that if you look at + + + align:start position:0% +report in class is that if you look at +the six strategy bundles at the maximum + + align:start position:0% +the six strategy bundles at the maximum + + + align:start position:0% +the six strategy bundles at the maximum +and aggressive deployment levels you can + + align:start position:0% +and aggressive deployment levels you can + + + align:start position:0% +and aggressive deployment levels you can +see that the most Max the maximum range + + align:start position:0% +see that the most Max the maximum range + + + align:start position:0% +see that the most Max the maximum range +of full National regional and local + + align:start position:0% +of full National regional and local + + + align:start position:0% +of full National regional and local +effort only gets this to about a 24% + + align:start position:0% +effort only gets this to about a 24% + + + align:start position:0% +effort only gets this to about a 24% +reduction in V GRE gas emissions the + + align:start position:0% +reduction in V GRE gas emissions the + + + align:start position:0% +reduction in V GRE gas emissions the +report was written in 2009 they had a 4% + + align:start position:0% +report was written in 2009 they had a 4% + + + align:start position:0% +report was written in 2009 they had a 4% +decline already baked in I assume + + align:start position:0% +decline already baked in I assume + + + align:start position:0% +decline already baked in I assume +largely from vehicle efficiency + + align:start position:0% +largely from vehicle efficiency + + + align:start position:0% +largely from vehicle efficiency +standards but if we do everything in the + + align:start position:0% +standards but if we do everything in the + + + align:start position:0% +standards but if we do everything in the +report that they analyze which we'll + + align:start position:0% +report that they analyze which we'll + + + align:start position:0% +report that they analyze which we'll +talk more about you only get to a 24% + + align:start position:0% +talk more about you only get to a 24% + + + align:start position:0% +talk more about you only get to a 24% +reduction of course a 24% reduction in + + align:start position:0% +reduction of course a 24% reduction in + + + align:start position:0% +reduction of course a 24% reduction in +transcation which is about 30% % of our + + align:start position:0% +transcation which is about 30% % of our + + + align:start position:0% +transcation which is about 30% % of our +total greenhous gas missions is not + + align:start position:0% +total greenhous gas missions is not + + + align:start position:0% +total greenhous gas missions is not +nothing that's about a seven or 8% + + align:start position:0% +nothing that's about a seven or 8% + + + align:start position:0% +nothing that's about a seven or 8% +reduction in our total greenhous gas + + align:start position:0% +reduction in our total greenhous gas + + + align:start position:0% +reduction in our total greenhous gas +missions by 2050 but obviously a small + + align:start position:0% +missions by 2050 but obviously a small + + + align:start position:0% +missions by 2050 but obviously a small +drop in the bucket towards where we need + + align:start position:0% +drop in the bucket towards where we need + + + align:start position:0% +drop in the bucket towards where we need +to go in + + align:start position:0% +to go in + + + align:start position:0% +to go in +2050 but and if we just maybe highlight + + align:start position:0% +2050 but and if we just maybe highlight + + + align:start position:0% +2050 but and if we just maybe highlight +that again you can see that the maximum + + align:start position:0% +that again you can see that the maximum + + + align:start position:0% +that again you can see that the maximum +level deployment reduces millions of + + align:start position:0% +level deployment reduces millions of + + + align:start position:0% +level deployment reduces millions of +barrels per year by 11 maybe 110 to 470 + + align:start position:0% +barrels per year by 11 maybe 110 to 470 + + + align:start position:0% +barrels per year by 11 maybe 110 to 470 +million barrels per year but the + + align:start position:0% +million barrels per year but the + + + align:start position:0% +million barrels per year but the +consumption in the US is 5.7 million + + align:start position:0% +consumption in the US is 5.7 million + + + align:start position:0% +consumption in the US is 5.7 million +barrels per day so in other this range + + align:start position:0% +barrels per day so in other this range + + + align:start position:0% +barrels per day so in other this range +is only about 19 or 82 days per year in + + align:start position:0% +is only about 19 or 82 days per year in + + + align:start position:0% +is only about 19 or 82 days per year in +the transportation system alone these + + align:start position:0% +the transportation system alone these + + + align:start position:0% +the transportation system alone these +assumptions of course could have changed + + align:start position:0% +assumptions of course could have changed + + + align:start position:0% +assumptions of course could have changed +in the last 13 year last 13 years but I + + align:start position:0% +in the last 13 year last 13 years but I + + + align:start position:0% +in the last 13 year last 13 years but I +think this just highlights that you know + + align:start position:0% +think this just highlights that you know + + + align:start position:0% +think this just highlights that you know +transportation is a really hard to + + align:start position:0% +transportation is a really hard to + + + align:start position:0% +transportation is a really hard to +decarbonize + + align:start position:0% +decarbonize + + + align:start position:0% +decarbonize +sector now there's one point that I want + + align:start position:0% +sector now there's one point that I want + + + align:start position:0% +sector now there's one point that I want +to make about all of these different + + align:start position:0% +to make about all of these different + + + align:start position:0% +to make about all of these different +strategies and I think it's an important + + align:start position:0% +strategies and I think it's an important + + + align:start position:0% +strategies and I think it's an important +point to make which is we can have these + + align:start position:0% +point to make which is we can have these + + + align:start position:0% +point to make which is we can have these +six different approaches to trying to + + align:start position:0% +six different approaches to trying to + + + align:start position:0% +six different approaches to trying to +reduce our greenhouse gas assumptions in + + align:start position:0% +reduce our greenhouse gas assumptions in + + + align:start position:0% +reduce our greenhouse gas assumptions in +this First Column they all have varying + + align:start position:0% +this First Column they all have varying + + + align:start position:0% +this First Column they all have varying +degrees of greenhouse gas reduction they + + align:start position:0% +degrees of greenhouse gas reduction they + + + align:start position:0% +degrees of greenhouse gas reduction they +also have positive implementation costs + + align:start position:0% +also have positive implementation costs + + + align:start position:0% +also have positive implementation costs +you can see they cost different amounts + + align:start position:0% +you can see they cost different amounts + + + align:start position:0% +you can see they cost different amounts +the U System and Driver efficiency + + align:start position:0% +the U System and Driver efficiency + + + align:start position:0% +the U System and Driver efficiency +perhaps efforts are relatively expensive + + align:start position:0% +perhaps efforts are relatively expensive + + + align:start position:0% +perhaps efforts are relatively expensive +the long-term maximum results and + + align:start position:0% +the long-term maximum results and + + + align:start position:0% +the long-term maximum results and +facility pricing are relatively + + align:start position:0% +facility pricing are relatively + + + align:start position:0% +facility pricing are relatively +expensive but the point is all the + + align:start position:0% +expensive but the point is all the + + + align:start position:0% +expensive but the point is all the +implementation costs are positive but + + align:start position:0% +implementation costs are positive but + + + align:start position:0% +implementation costs are positive but +the changes in vehicle costs are all + + align:start position:0% +the changes in vehicle costs are all + + + align:start position:0% +the changes in vehicle costs are all +negative and much larger which is to say + + align:start position:0% +negative and much larger which is to say + + + align:start position:0% +negative and much larger which is to say +that vehicle costs in footnote B says + + align:start position:0% +that vehicle costs in footnote B says + + + align:start position:0% +that vehicle costs in footnote B says +it's the estimated cumul reduction the + + align:start position:0% +it's the estimated cumul reduction the + + + align:start position:0% +it's the estimated cumul reduction the +cost of owning and operating vehicles + + align:start position:0% +cost of owning and operating vehicles + + + align:start position:0% +cost of owning and operating vehicles +from a societal perspective which would + + align:start position:0% +from a societal perspective which would + + + align:start position:0% +from a societal perspective which would +result in reduction in vehicle miles + + align:start position:0% +result in reduction in vehicle miles + + + align:start position:0% +result in reduction in vehicle miles +travel and fuel consumption in other + + align:start position:0% +travel and fuel consumption in other + + + align:start position:0% +travel and fuel consumption in other +words even though the implementation + + align:start position:0% +words even though the implementation + + + align:start position:0% +words even though the implementation +cost for all these strategies is + + align:start position:0% +cost for all these strategies is + + + align:start position:0% +cost for all these strategies is +positive the change in vehicle cost is + + align:start position:0% +positive the change in vehicle cost is + + + align:start position:0% +positive the change in vehicle cost is +negative and much larger which means if + + align:start position:0% +negative and much larger which means if + + + align:start position:0% +negative and much larger which means if +you take the implementation cost minus + + align:start position:0% +you take the implementation cost minus + + + align:start position:0% +you take the implementation cost minus +vehicle costs you can see in almost all + + align:start position:0% +vehicle costs you can see in almost all + + + align:start position:0% +vehicle costs you can see in almost all +these cases five out of six cases we + + align:start position:0% +these cases five out of six cases we + + + align:start position:0% +these cases five out of six cases we +actually save a lot of money over the + + align:start position:0% +actually save a lot of money over the + + + align:start position:0% +actually save a lot of money over the +forecast for these different strategies + + align:start position:0% +forecast for these different strategies + + + align:start position:0% +forecast for these different strategies +this is that the aggressive level + + align:start position:0% +this is that the aggressive level + + + align:start position:0% +this is that the aggressive level +deployment if you look at maximum level + + align:start position:0% +deployment if you look at maximum level + + + align:start position:0% +deployment if you look at maximum level +of deployment again five out of these + + align:start position:0% +of deployment again five out of these + + + align:start position:0% +of deployment again five out of these +six strategies are actually negative + + align:start position:0% +six strategies are actually negative + + + align:start position:0% +six strategies are actually negative +cost so if we look at the greenhouse gas + + align:start position:0% +cost so if we look at the greenhouse gas + + + align:start position:0% +cost so if we look at the greenhouse gas +reductions that results they actually + + align:start position:0% +reductions that results they actually + + + align:start position:0% +reductions that results they actually +have a negative cost per ton which is to + + align:start position:0% +have a negative cost per ton which is to + + + align:start position:0% +have a negative cost per ton which is to +say that not only do you save money you + + align:start position:0% +say that not only do you save money you + + + align:start position:0% +say that not only do you save money you +can also reduce greenhouse gas emissions + + align:start position:0% +can also reduce greenhouse gas emissions + + + align:start position:0% +can also reduce greenhouse gas emissions +and that's true for five out of the six + + align:start position:0% +and that's true for five out of the six + + + align:start position:0% +and that's true for five out of the six +strategies at the aggressive deployment + + align:start position:0% +strategies at the aggressive deployment + + + align:start position:0% +strategies at the aggressive deployment +level and it's true for four out of the + + align:start position:0% +level and it's true for four out of the + + + align:start position:0% +level and it's true for four out of the +six strategies at the maximum deployment + + align:start position:0% +six strategies at the maximum deployment + + + align:start position:0% +six strategies at the maximum deployment +level this is not taking into account + + align:start position:0% +level this is not taking into account + + + align:start position:0% +level this is not taking into account +the cost of actually reducing carbon or + + align:start position:0% +the cost of actually reducing carbon or + + + align:start position:0% +the cost of actually reducing carbon or +the social cost of carbon for example + + align:start position:0% +the social cost of carbon for example + + + align:start position:0% +the social cost of carbon for example +the net cost of reducing a ton of gas + + align:start position:0% +the net cost of reducing a ton of gas + + + align:start position:0% +the net cost of reducing a ton of gas +gas emissions in the near-term or early + + align:start position:0% +gas emissions in the near-term or early + + + align:start position:0% +gas emissions in the near-term or early +results is negative $410 per ton at + + align:start position:0% +results is negative $410 per ton at + + + align:start position:0% +results is negative $410 per ton at +maximum deployment level which means + + align:start position:0% +maximum deployment level which means + + + align:start position:0% +maximum deployment level which means +that we would actually save $400 for + + align:start position:0% +that we would actually save $400 for + + + align:start position:0% +that we would actually save $400 for +every ton of greenhous gas emissions we + + align:start position:0% +every ton of greenhous gas emissions we + + + align:start position:0% +every ton of greenhous gas emissions we +saving that's not even including + + align:start position:0% +saving that's not even including + + + align:start position:0% +saving that's not even including +including the $51 the federal government + + align:start position:0% +including the $51 the federal government + + + align:start position:0% +including the $51 the federal government +says every ton of gas emissions cost us + + align:start position:0% +says every ton of gas emissions cost us + + + align:start position:0% +says every ton of gas emissions cost us +or the $150 that the most recent studies + + align:start position:0% +or the $150 that the most recent studies + + + align:start position:0% +or the $150 that the most recent studies +say is the social cost of carbon so this + + align:start position:0% +say is the social cost of carbon so this + + + align:start position:0% +say is the social cost of carbon so this +is to say that we should try to do the + + align:start position:0% +is to say that we should try to do the + + + align:start position:0% +is to say that we should try to do the +negative cost stuff because we're going + + align:start position:0% +negative cost stuff because we're going + + + align:start position:0% +negative cost stuff because we're going +to do greenhous gas missions and save + + align:start position:0% +to do greenhous gas missions and save + + + align:start position:0% +to do greenhous gas missions and save +ourselves money in fuel + + align:start position:0% +ourselves money in fuel + + + align:start position:0% +ourselves money in fuel +anyways just to show you this + + align:start position:0% +anyways just to show you this + + + align:start position:0% +anyways just to show you this +graphically this is for the near-term + + align:start position:0% +graphically this is for the near-term + + + align:start position:0% +graphically this is for the near-term +early results bundle aggressive + + align:start position:0% +early results bundle aggressive + + + align:start position:0% +early results bundle aggressive +deployment it cost about 20 billion doll + + align:start position:0% +deployment it cost about 20 billion doll + + + align:start position:0% +deployment it cost about 20 billion doll +in 2008 to implement between 2008 2050 + + align:start position:0% +in 2008 to implement between 2008 2050 + + + align:start position:0% +in 2008 to implement between 2008 2050 +but you can see the vehicle cost savings + + align:start position:0% +but you can see the vehicle cost savings + + + align:start position:0% +but you can see the vehicle cost savings +work that at their high point they're + + align:start position:0% +work that at their high point they're + + + align:start position:0% +work that at their high point they're +about five times more than the original + + align:start position:0% +about five times more than the original + + + align:start position:0% +about five times more than the original +the implementation cost that year and + + align:start position:0% +the implementation cost that year and + + + align:start position:0% +the implementation cost that year and +even at their lowest point in 2050 there + + align:start position:0% +even at their lowest point in 2050 there + + + align:start position:0% +even at their lowest point in 2050 there +are four times the implementation cost + + align:start position:0% +are four times the implementation cost + + + align:start position:0% +are four times the implementation cost +this isst to say if we make policy + + align:start position:0% +this isst to say if we make policy + + + align:start position:0% +this isst to say if we make policy +changes and change infrastructure we can + + align:start position:0% +changes and change infrastructure we can + + + align:start position:0% +changes and change infrastructure we can +reduce greenhouse gas emissions and save + + align:start position:0% +reduce greenhouse gas emissions and save + + + align:start position:0% +reduce greenhouse gas emissions and save +money in the long term throughout almost + + align:start position:0% +money in the long term throughout almost + + + align:start position:0% +money in the long term throughout almost +the entire life of this bundle and if + + align:start position:0% +the entire life of this bundle and if + + + align:start position:0% +the entire life of this bundle and if +you look at what that bundle is supposed + + align:start position:0% +you look at what that bundle is supposed + + + align:start position:0% +you look at what that bundle is supposed +of you can see that there's different + + align:start position:0% +of you can see that there's different + + + align:start position:0% +of you can see that there's different +categories this composed of Park pricing + + align:start position:0% +categories this composed of Park pricing + + + align:start position:0% +categories this composed of Park pricing +strategies for example a price on + + align:start position:0% +strategies for example a price on + + + align:start position:0% +strategies for example a price on +parking in Central Business districts + + align:start position:0% +parking in Central Business districts + + + align:start position:0% +parking in Central Business districts +a price on parking for free private + + align:start position:0% +a price on parking for free private + + + align:start position:0% +a price on parking for free private +parking residential parking permits and + + align:start position:0% +parking residential parking permits and + + + align:start position:0% +parking residential parking permits and +congestion pricing public transportation + + align:start position:0% +congestion pricing public transportation + + + align:start position:0% +congestion pricing public transportation +strategies we have commuting strategies + + align:start position:0% +strategies we have commuting strategies + + + align:start position:0% +strategies we have commuting strategies +we regulatory strategies system + + align:start position:0% +we regulatory strategies system + + + align:start position:0% +we regulatory strategies system +operation strategies and multim modal + + align:start position:0% +operation strategies and multim modal + + + align:start position:0% +operation strategies and multim modal +Freight strategies all these things + + align:start position:0% +Freight strategies all these things + + + align:start position:0% +Freight strategies all these things +together get us a 14% decrease in Prenos + + align:start position:0% +together get us a 14% decrease in Prenos + + + align:start position:0% +together get us a 14% decrease in Prenos +gas emissions from just the near-term + + align:start position:0% +gas emissions from just the near-term + + + align:start position:0% +gas emissions from just the near-term +early results bundle but also crucially + + align:start position:0% +early results bundle but also crucially + + + align:start position:0% +early results bundle but also crucially +it is saving us money in this bundle + + align:start position:0% +it is saving us money in this bundle + + + align:start position:0% +it is saving us money in this bundle +throughout the lifetime of the bundle if + + align:start position:0% +throughout the lifetime of the bundle if + + + align:start position:0% +throughout the lifetime of the bundle if +we do the longterm our maximum results + + align:start position:0% +we do the longterm our maximum results + + + align:start position:0% +we do the longterm our maximum results +bundle at aggressive levels of + + align:start position:0% +bundle at aggressive levels of + + + align:start position:0% +bundle at aggressive levels of +deployment you can see that our vehicle + + align:start position:0% +deployment you can see that our vehicle + + + align:start position:0% +deployment you can see that our vehicle +C our implementation costs start off + + align:start position:0% +C our implementation costs start off + + + align:start position:0% +C our implementation costs start off +much higher around $80 billion was taper + + align:start position:0% +much higher around $80 billion was taper + + + align:start position:0% +much higher around $80 billion was taper +down to $60 billion a year in 2050 but + + align:start position:0% +down to $60 billion a year in 2050 but + + + align:start position:0% +down to $60 billion a year in 2050 but +our vehicle cost savings are still + + align:start position:0% +our vehicle cost savings are still + + + align:start position:0% +our vehicle cost savings are still +almost a factor of two or three higher + + align:start position:0% +almost a factor of two or three higher + + + align:start position:0% +almost a factor of two or three higher +than with notation costs which is to say + + align:start position:0% +than with notation costs which is to say + + + align:start position:0% +than with notation costs which is to say +that we are going to save money through + + align:start position:0% +that we are going to save money through + + + align:start position:0% +that we are going to save money through +lifetime of this analysis and you can + + align:start position:0% +lifetime of this analysis and you can + + + align:start position:0% +lifetime of this analysis and you can +see that to get to our maximum level of + + align:start position:0% +see that to get to our maximum level of + + + align:start position:0% +see that to get to our maximum level of +deployment that's our 24% reduction we + + align:start position:0% +deployment that's our 24% reduction we + + + align:start position:0% +deployment that's our 24% reduction we +have to do many more things over the + + align:start position:0% +have to do many more things over the + + + align:start position:0% +have to do many more things over the +long term to get our maximum results + + align:start position:0% +long term to get our maximum results + + + align:start position:0% +long term to get our maximum results +I'll let you dive into the report to + + align:start position:0% +I'll let you dive into the report to + + + align:start position:0% +I'll let you dive into the report to +understand what some of these policies + + align:start position:0% +understand what some of these policies + + + align:start position:0% +understand what some of these policies +are but all these policies are things + + align:start position:0% +are but all these policies are things + + + align:start position:0% +are but all these policies are things +that you can work on in your + + align:start position:0% +that you can work on in your + + + align:start position:0% +that you can work on in your +careers if you look at the uh same + + align:start position:0% +careers if you look at the uh same + + + align:start position:0% +careers if you look at the uh same +bundle in terms of the graphics you can + + align:start position:0% +bundle in terms of the graphics you can + + + align:start position:0% +bundle in terms of the graphics you can +see that it starts off I think this one + + align:start position:0% +see that it starts off I think this one + + + align:start position:0% +see that it starts off I think this one +might actually be repeated from before + + align:start position:0% +might actually be repeated from before + + + align:start position:0% +might actually be repeated from before +apologies but the crucial thing is + + align:start position:0% +apologies but the crucial thing is + + + align:start position:0% +apologies but the crucial thing is +here's all the uh strategy that comprise + + align:start position:0% +here's all the uh strategy that comprise + + + align:start position:0% +here's all the uh strategy that comprise +this bundle and you can see the land use + + align:start position:0% +this bundle and you can see the land use + + + align:start position:0% +this bundle and you can see the land use +Transit nonmotorized transation bundle + + align:start position:0% +Transit nonmotorized transation bundle + + + align:start position:0% +Transit nonmotorized transation bundle +which is something that planners focus + + align:start position:0% +which is something that planners focus + + + align:start position:0% +which is something that planners focus +on quite a bit the implementation costs + + align:start position:0% +on quite a bit the implementation costs + + + align:start position:0% +on quite a bit the implementation costs +are slightly higher than our near-term + + align:start position:0% +are slightly higher than our near-term + + + align:start position:0% +are slightly higher than our near-term +results but again our vehicle cost + + align:start position:0% +results but again our vehicle cost + + + align:start position:0% +results but again our vehicle cost +savings are roughly two or three times + + align:start position:0% +savings are roughly two or three times + + + align:start position:0% +savings are roughly two or three times +what our implementation costs are and + + align:start position:0% +what our implementation costs are and + + + align:start position:0% +what our implementation costs are and +you can see that there are many things + + align:start position:0% +you can see that there are many things + + + align:start position:0% +you can see that there are many things +that urban planners love ranging from + + align:start position:0% +that urban planners love ranging from + + + align:start position:0% +that urban planners love ranging from +pricing strategies transportation to + + align:start position:0% +pricing strategies transportation to + + + align:start position:0% +pricing strategies transportation to +land use and smart growth strategies to + + align:start position:0% +land use and smart growth strategies to + + + align:start position:0% +land use and smart growth strategies to +public transportation strategies to + + align:start position:0% +public transportation strategies to + + + align:start position:0% +public transportation strategies to +regulatory strategies and so on so this + + align:start position:0% +regulatory strategies and so on so this + + + align:start position:0% +regulatory strategies and so on so this +brings me to the idea of marginal + + align:start position:0% +brings me to the idea of marginal + + + align:start position:0% +brings me to the idea of marginal +abatement this is a very famous graph + + align:start position:0% +abatement this is a very famous graph + + + align:start position:0% +abatement this is a very famous graph +done in 2008 by McKenzie McKenzie didn't + + align:start position:0% +done in 2008 by McKenzie McKenzie didn't + + + align:start position:0% +done in 2008 by McKenzie McKenzie didn't +invent the marginal abatement cost curve + + align:start position:0% +invent the marginal abatement cost curve + + + align:start position:0% +invent the marginal abatement cost curve +but they certainly popularized it in a + + align:start position:0% +but they certainly popularized it in a + + + align:start position:0% +but they certainly popularized it in a +2008 report that was studying the cost + + align:start position:0% +2008 report that was studying the cost + + + align:start position:0% +2008 report that was studying the cost +to reduce greenhouse gas emissions + + align:start position:0% +to reduce greenhouse gas emissions + + + align:start position:0% +to reduce greenhouse gas emissions +across the US economy arguably that 2008 + + align:start position:0% +across the US economy arguably that 2008 + + + align:start position:0% +across the US economy arguably that 2008 +report by McKenzie inspired the moving + + align:start position:0% +report by McKenzie inspired the moving + + + align:start position:0% +report by McKenzie inspired the moving +Pooler report in 2009 but the key thing + + align:start position:0% +Pooler report in 2009 but the key thing + + + align:start position:0% +Pooler report in 2009 but the key thing +is here is that what you do is you graph + + align:start position:0% +is here is that what you do is you graph + + + align:start position:0% +is here is that what you do is you graph +on the horizontal axis the potential + + align:start position:0% +on the horizontal axis the potential + + + align:start position:0% +on the horizontal axis the potential +Savings in terms of gigatons of carbon + + align:start position:0% +Savings in terms of gigatons of carbon + + + align:start position:0% +Savings in terms of gigatons of carbon +dioxide equivalent per year the width of + + align:start position:0% +dioxide equivalent per year the width of + + + align:start position:0% +dioxide equivalent per year the width of +each of these bars tells you how much + + align:start position:0% +each of these bars tells you how much + + + align:start position:0% +each of these bars tells you how much +potential is associated with each of + + align:start position:0% +potential is associated with each of + + + align:start position:0% +potential is associated with each of +these different Technologies or policies + + align:start position:0% +these different Technologies or policies + + + align:start position:0% +these different Technologies or policies +crucial thing here is on the vertical + + align:start position:0% +crucial thing here is on the vertical + + + align:start position:0% +crucial thing here is on the vertical +axis you can see that some things cost + + align:start position:0% +axis you can see that some things cost + + + align:start position:0% +axis you can see that some things cost +money to reduce a ton of greenhouse gas + + align:start position:0% +money to reduce a ton of greenhouse gas + + + align:start position:0% +money to reduce a ton of greenhouse gas +missions and some things like our moving + + align:start position:0% +missions and some things like our moving + + + align:start position:0% +missions and some things like our moving +pool report are negative you actually + + align:start position:0% +pool report are negative you actually + + + align:start position:0% +pool report are negative you actually +save money and you reduce greenhouse gas + + align:start position:0% +save money and you reduce greenhouse gas + + + align:start position:0% +save money and you reduce greenhouse gas +emissions my unsolicited career advice + + align:start position:0% +emissions my unsolicited career advice + + + align:start position:0% +emissions my unsolicited career advice +to all of you is that you want to be on + + align:start position:0% +to all of you is that you want to be on + + + align:start position:0% +to all of you is that you want to be on +the left hand side of this curve the + + align:start position:0% +the left hand side of this curve the + + + align:start position:0% +the left hand side of this curve the +left hand side of the curve are all + + align:start position:0% +left hand side of the curve are all + + + align:start position:0% +left hand side of the curve are all +things that are essentially free for + + align:start position:0% +things that are essentially free for + + + align:start position:0% +things that are essentially free for +people and they achieve our + + align:start position:0% +people and they achieve our + + + align:start position:0% +people and they achieve our +environmental goals so it is much easier + + align:start position:0% +environmental goals so it is much easier + + + align:start position:0% +environmental goals so it is much easier +to sell let's say changes in commercial + + align:start position:0% +to sell let's say changes in commercial + + + align:start position:0% +to sell let's say changes in commercial +buildings and residential buildings and + + align:start position:0% +buildings and residential buildings and + + + align:start position:0% +buildings and residential buildings and +fuel economy packages then it will be to + + align:start position:0% +fuel economy packages then it will be to + + + align:start position:0% +fuel economy packages then it will be to +do things like solar concentrating solar + + align:start position:0% +do things like solar concentrating solar + + + align:start position:0% +do things like solar concentrating solar +concentrating solar power solar CSP + + align:start position:0% +concentrating solar power solar CSP + + + align:start position:0% +concentrating solar power solar CSP +which is a very Hot Topic in 2008 but + + align:start position:0% +which is a very Hot Topic in 2008 but + + + align:start position:0% +which is a very Hot Topic in 2008 but +we've proven over the last 10 years that + + align:start position:0% +we've proven over the last 10 years that + + + align:start position:0% +we've proven over the last 10 years that +those costs have never gone down as much + + align:start position:0% +those costs have never gone down as much + + + align:start position:0% +those costs have never gone down as much +as solar panels have this is probably + + align:start position:0% +as solar panels have this is probably + + + align:start position:0% +as solar panels have this is probably +out of date distributed solar PV has + + align:start position:0% +out of date distributed solar PV has + + + align:start position:0% +out of date distributed solar PV has +become much cheaper + + align:start position:0% +become much cheaper + + + align:start position:0% +become much cheaper +but you know even if you compare this + + align:start position:0% +but you know even if you compare this + + + align:start position:0% +but you know even if you compare this +solar distributed PV is relatively + + align:start position:0% +solar distributed PV is relatively + + + align:start position:0% +solar distributed PV is relatively +expensive compared to utility scale what + + align:start position:0% +expensive compared to utility scale what + + + align:start position:0% +expensive compared to utility scale what +will TS but of course those things are + + align:start position:0% +will TS but of course those things are + + + align:start position:0% +will TS but of course those things are +still more expensive than residential + + align:start position:0% +still more expensive than residential + + + align:start position:0% +still more expensive than residential +water heaters not the sexiest topic but + + align:start position:0% +water heaters not the sexiest topic but + + + align:start position:0% +water heaters not the sexiest topic but +a place where you can actually have + + align:start position:0% +a place where you can actually have + + + align:start position:0% +a place where you can actually have +significant impact it has a negative + + align:start position:0% +significant impact it has a negative + + + align:start position:0% +significant impact it has a negative +cost and has a significant potential + + align:start position:0% +cost and has a significant potential + + + align:start position:0% +cost and has a significant potential +combined heat and Power Residential + + align:start position:0% +combined heat and Power Residential + + + align:start position:0% +combined heat and Power Residential +Building lighting these are fundamental + + align:start position:0% +Building lighting these are fundamental + + + align:start position:0% +Building lighting these are fundamental +changes we can make in buildings which + + align:start position:0% +changes we can make in buildings which + + + align:start position:0% +changes we can make in buildings which +we'll talk about in the next few + + align:start position:0% +we'll talk about in the next few + + + align:start position:0% +we'll talk about in the next few +lectures the point of this is that you + + align:start position:0% +lectures the point of this is that you + + + align:start position:0% +lectures the point of this is that you +can be time do things that have negative + + align:start position:0% +can be time do things that have negative + + + align:start position:0% +can be time do things that have negative +cost and reduced green gas emissions + + align:start position:0% +cost and reduced green gas emissions + + + align:start position:0% +cost and reduced green gas emissions +which is something we can analyze from + + align:start position:0% +which is something we can analyze from + + + align:start position:0% +which is something we can analyze from +the moving cooler report if you look at + + align:start position:0% +the moving cooler report if you look at + + + align:start position:0% +the moving cooler report if you look at +the moving cooler report on the around + + align:start position:0% +the moving cooler report on the around + + + align:start position:0% +the moving cooler report on the around +page 47 or so you can see different + + align:start position:0% +page 47 or so you can see different + + + align:start position:0% +page 47 or so you can see different +categories of how much potential there + + align:start position:0% +categories of how much potential there + + + align:start position:0% +categories of how much potential there +is to reduce greous gas emissions this + + align:start position:0% +is to reduce greous gas emissions this + + + align:start position:0% +is to reduce greous gas emissions this +is the at expanded aggressive and + + align:start position:0% +is the at expanded aggressive and + + + align:start position:0% +is the at expanded aggressive and +maximum levels and you can see on a + + align:start position:0% +maximum levels and you can see on a + + + align:start position:0% +maximum levels and you can see on a +categorized basis that pricing + + align:start position:0% +categorized basis that pricing + + + align:start position:0% +categorized basis that pricing +strategies are basically as much as + + align:start position:0% +strategies are basically as much as + + + align:start position:0% +strategies are basically as much as +everything else put together however on + + align:start position:0% +everything else put together however on + + + align:start position:0% +everything else put together however on +a per unit basis or on a cost basis you + + align:start position:0% +a per unit basis or on a cost basis you + + + align:start position:0% +a per unit basis or on a cost basis you +can also see that the negative costs are + + align:start position:0% +can also see that the negative costs are + + + align:start position:0% +can also see that the negative costs are +R our public transportation strategies + + align:start position:0% +R our public transportation strategies + + + align:start position:0% +R our public transportation strategies +as we talked about in class are + + align:start position:0% +as we talked about in class are + + + align:start position:0% +as we talked about in class are +relatively expensive they don't always + + align:start position:0% +relatively expensive they don't always + + + align:start position:0% +relatively expensive they don't always +recover they don't have Fair box + + align:start position:0% +recover they don't have Fair box + + + align:start position:0% +recover they don't have Fair box +recovery or they don't recover their + + align:start position:0% +recovery or they don't recover their + + + align:start position:0% +recovery or they don't recover their +full cost Through the Fair box but we + + align:start position:0% +full cost Through the Fair box but we + + + align:start position:0% +full cost Through the Fair box but we +might invest in public transportation as + + align:start position:0% +might invest in public transportation as + + + align:start position:0% +might invest in public transportation as +a public good it also has benefits in + + align:start position:0% +a public good it also has benefits in + + + align:start position:0% +a public good it also has benefits in +livability and safety and access the + + align:start position:0% +livability and safety and access the + + + align:start position:0% +livability and safety and access the +things that this report doesn't + + align:start position:0% +things that this report doesn't + + + align:start position:0% +things that this report doesn't +necessarily include but it's also worth + + align:start position:0% +necessarily include but it's also worth + + + align:start position:0% +necessarily include but it's also worth +noting there's lots of other things we + + align:start position:0% +noting there's lots of other things we + + + align:start position:0% +noting there's lots of other things we +can do that essentially have a negative + + align:start position:0% +can do that essentially have a negative + + + align:start position:0% +can do that essentially have a negative +economic cost they probably have + + align:start position:0% +economic cost they probably have + + + align:start position:0% +economic cost they probably have +beneficial costs in terms of uh safety + + align:start position:0% +beneficial costs in terms of uh safety + + + align:start position:0% +beneficial costs in terms of uh safety +and health they're just not included in + + align:start position:0% +and health they're just not included in + + + align:start position:0% +and health they're just not included in +this report so everything here in red + + align:start position:0% +this report so everything here in red + + + align:start position:0% +this report so everything here in red +and almost all levels of deployment is a + + align:start position:0% +and almost all levels of deployment is a + + + align:start position:0% +and almost all levels of deployment is a +negative cost and a reduce gas emission + + align:start position:0% +negative cost and a reduce gas emission + + + align:start position:0% +negative cost and a reduce gas emission +this is a cost of um a a cost of + + align:start position:0% +this is a cost of um a a cost of + + + align:start position:0% +this is a cost of um a a cost of +reducing a ton of greous gas emissions + + align:start position:0% +reducing a ton of greous gas emissions + + + align:start position:0% +reducing a ton of greous gas emissions +you can see that in the data analysis I + + align:start position:0% +you can see that in the data analysis I + + + align:start position:0% +you can see that in the data analysis I +look at the total reduction divided by + + align:start position:0% +look at the total reduction divided by + + + align:start position:0% +look at the total reduction divided by +the net + + align:start position:0% +the net + + + align:start position:0% +the net +cost and if we break it down into the + + align:start position:0% +cost and if we break it down into the + + + align:start position:0% +cost and if we break it down into the +very strategies you can see that the + + align:start position:0% +very strategies you can see that the + + + align:start position:0% +very strategies you can see that the +category of system operations and + + align:start position:0% +category of system operations and + + + align:start position:0% +category of system operations and +management is composed of active traffic + + align:start position:0% +management is composed of active traffic + + + align:start position:0% +management is composed of active traffic +management integrated Corridor + + align:start position:0% +management integrated Corridor + + + align:start position:0% +management integrated Corridor +management signal control management + + align:start position:0% +management signal control management + + + align:start position:0% +management signal control management +these all have a the maximum level + + align:start position:0% +these all have a the maximum level + + + align:start position:0% +these all have a the maximum level +deployment a cost to reduce a metric ton + + align:start position:0% +deployment a cost to reduce a metric ton + + + align:start position:0% +deployment a cost to reduce a metric ton +of carbon dioxide equivalent these are + + align:start position:0% +of carbon dioxide equivalent these are + + + align:start position:0% +of carbon dioxide equivalent these are +all positive + + align:start position:0% +all positive + + + align:start position:0% +all positive +costs you can see that if we move one + + align:start position:0% +costs you can see that if we move one + + + align:start position:0% +costs you can see that if we move one +page down you can see lots of other the + + align:start position:0% +page down you can see lots of other the + + + align:start position:0% +page down you can see lots of other the +things have negative costs I would argue + + align:start position:0% +things have negative costs I would argue + + + align:start position:0% +things have negative costs I would argue +you negative costs are the things that + + align:start position:0% +you negative costs are the things that + + + align:start position:0% +you negative costs are the things that +should be easiest to sell in your career + + align:start position:0% +should be easiest to sell in your career + + + align:start position:0% +should be easiest to sell in your career +and of course if you look at something + + align:start position:0% +and of course if you look at something + + + align:start position:0% +and of course if you look at something +that is not very glamorous Incident + + align:start position:0% +that is not very glamorous Incident + + + align:start position:0% +that is not very glamorous Incident +Management Incident Management looks + + align:start position:0% +Management Incident Management looks + + + align:start position:0% +Management Incident Management looks +like on a per cost basis basically + + align:start position:0% +like on a per cost basis basically + + + align:start position:0% +like on a per cost basis basically +almost the equivalent of everything else + + align:start position:0% +almost the equivalent of everything else + + + align:start position:0% +almost the equivalent of everything else +put together so I would argue that this + + align:start position:0% +put together so I would argue that this + + + align:start position:0% +put together so I would argue that this +is the first thing we should be doing to + + align:start position:0% +is the first thing we should be doing to + + + align:start position:0% +is the first thing we should be doing to +try to reduce greenos gas + + align:start position:0% +try to reduce greenos gas + + + align:start position:0% +try to reduce greenos gas +emissions if we look at the expanded + + align:start position:0% +emissions if we look at the expanded + + + align:start position:0% +emissions if we look at the expanded +aggressive and maximum levels of effort + + align:start position:0% +aggressive and maximum levels of effort + + + align:start position:0% +aggressive and maximum levels of effort +just to talk about that a little bit + + align:start position:0% +just to talk about that a little bit + + + align:start position:0% +just to talk about that a little bit +more expanding current practice is + + align:start position:0% +more expanding current practice is + + + align:start position:0% +more expanding current practice is +basically in large urban areas that + + align:start position:0% +basically in large urban areas that + + + align:start position:0% +basically in large urban areas that +already have Transit medium area + + align:start position:0% +already have Transit medium area + + + align:start position:0% +already have Transit medium area +medium urban areas that have Transit and + + align:start position:0% +medium urban areas that have Transit and + + + align:start position:0% +medium urban areas that have Transit and +small areas that have Transit already + + align:start position:0% +small areas that have Transit already + + + align:start position:0% +small areas that have Transit already +and then in the future we'll try to + + align:start position:0% +and then in the future we'll try to + + + align:start position:0% +and then in the future we'll try to +improve the large urban areas medium + + align:start position:0% +improve the large urban areas medium + + + align:start position:0% +improve the large urban areas medium +urban areas and small urban areas in bit + + align:start position:0% +urban areas and small urban areas in bit + + + align:start position:0% +urban areas and small urban areas in bit +if we want to be more aggressive we'll + + align:start position:0% +if we want to be more aggressive we'll + + + align:start position:0% +if we want to be more aggressive we'll +start doing this faster for all these + + align:start position:0% +start doing this faster for all these + + + align:start position:0% +start doing this faster for all these +categories and bring them up in time and + + align:start position:0% +categories and bring them up in time and + + + align:start position:0% +categories and bring them up in time and +a maximum effort would have been to + + align:start position:0% +a maximum effort would have been to + + + align:start position:0% +a maximum effort would have been to +start 10 years ago in 2010 or so to try + + align:start position:0% +start 10 years ago in 2010 or so to try + + + align:start position:0% +start 10 years ago in 2010 or so to try +to do all of our Metro areas or all of + + align:start position:0% +to do all of our Metro areas or all of + + + align:start position:0% +to do all of our Metro areas or all of +our urban areas with these TR ation + + align:start position:0% +our urban areas with these TR ation + + + align:start position:0% +our urban areas with these TR ation +interventions to I finally got around to + + align:start position:0% +interventions to I finally got around to + + + align:start position:0% +interventions to I finally got around to +making a marginal bait cost curve from + + align:start position:0% +making a marginal bait cost curve from + + + align:start position:0% +making a marginal bait cost curve from +the moving Pooler report itself you can + + align:start position:0% +the moving Pooler report itself you can + + + align:start position:0% +the moving Pooler report itself you can +see we have these nine different + + align:start position:0% +see we have these nine different + + + align:start position:0% +see we have these nine different +categories of strategy types I think + + align:start position:0% +categories of strategy types I think + + + align:start position:0% +categories of strategy types I think +this very thin sliver over here is + + align:start position:0% +this very thin sliver over here is + + + align:start position:0% +this very thin sliver over here is +probably the Incident Management I + + align:start position:0% +probably the Incident Management I + + + align:start position:0% +probably the Incident Management I +mentioned before and you can see the + + align:start position:0% +mentioned before and you can see the + + + align:start position:0% +mentioned before and you can see the +system operations and management + + align:start position:0% +system operations and management + + + align:start position:0% +system operations and management +strategies are relatively cost effective + + align:start position:0% +strategies are relatively cost effective + + + align:start position:0% +strategies are relatively cost effective +they're negative cost but have fairly + + align:start position:0% +they're negative cost but have fairly + + + align:start position:0% +they're negative cost but have fairly +large potential you can see that much of + + align:start position:0% +large potential you can see that much of + + + align:start position:0% +large potential you can see that much of +our negative potential here is composed + + align:start position:0% +our negative potential here is composed + + + align:start position:0% +our negative potential here is composed +of pricing strategies which is going to + + align:start position:0% +of pricing strategies which is going to + + + align:start position:0% +of pricing strategies which is going to +be very politically very difficult but + + align:start position:0% +be very politically very difficult but + + + align:start position:0% +be very politically very difficult but +worthwhile but we can also get a lot of + + align:start position:0% +worthwhile but we can also get a lot of + + + align:start position:0% +worthwhile but we can also get a lot of +changes uh in our transportation system + + align:start position:0% +changes uh in our transportation system + + + align:start position:0% +changes uh in our transportation system +emissions simply by changing our + + align:start position:0% +emissions simply by changing our + + + align:start position:0% +emissions simply by changing our +regulatory strategies and I'll let you + + align:start position:0% +regulatory strategies and I'll let you + + + align:start position:0% +regulatory strategies and I'll let you +look at the report to see what those are + + align:start position:0% +look at the report to see what those are + + + align:start position:0% +look at the report to see what those are +uh we do love uh our land use and smart + + align:start position:0% +uh we do love uh our land use and smart + + + align:start position:0% +uh we do love uh our land use and smart +growth strategies it's a very small box + + align:start position:0% +growth strategies it's a very small box + + + align:start position:0% +growth strategies it's a very small box +here and public transportation + + align:start position:0% +here and public transportation + + + align:start position:0% +here and public transportation +strategies as I said before tend to have + + align:start position:0% +strategies as I said before tend to have + + + align:start position:0% +strategies as I said before tend to have +a positive cost but actually do reduce + + align:start position:0% +a positive cost but actually do reduce + + + align:start position:0% +a positive cost but actually do reduce +gas emissions but you can see that all + + align:start position:0% +gas emissions but you can see that all + + + align:start position:0% +gas emissions but you can see that all +the things we often talk about as urban + + align:start position:0% +the things we often talk about as urban + + + align:start position:0% +the things we often talk about as urban +planners are relatively small and + + align:start position:0% +planners are relatively small and + + + align:start position:0% +planners are relatively small and +potential there are lots of things we + + align:start position:0% +potential there are lots of things we + + + align:start position:0% +potential there are lots of things we +can do over here in pricing strategy and + + align:start position:0% +can do over here in pricing strategy and + + + align:start position:0% +can do over here in pricing strategy and +Regulatory measures that I would argue + + align:start position:0% +Regulatory measures that I would argue + + + align:start position:0% +Regulatory measures that I would argue +we don't talk about enough in urban + + align:start position:0% +we don't talk about enough in urban + + + align:start position:0% +we don't talk about enough in urban +planning HOV carpol man poool communting + + align:start position:0% +planning HOV carpol man poool communting + + + align:start position:0% +planning HOV carpol man poool communting +strategies this blue box right here at + + align:start position:0% +strategies this blue box right here at + + + align:start position:0% +strategies this blue box right here at +all if we go to an aggressive level I've + + align:start position:0% +all if we go to an aggressive level I've + + + align:start position:0% +all if we go to an aggressive level I've +replotted this with the social cost of + + align:start position:0% +replotted this with the social cost of + + + align:start position:0% +replotted this with the social cost of +carbon at + + align:start position:0% +carbon at + + + align:start position:0% +carbon at +$150 per million metric sorry $150 per + + align:start position:0% +$150 per million metric sorry $150 per + + + align:start position:0% +$150 per million metric sorry $150 per +metric ton of carbon di equival + + align:start position:0% +metric ton of carbon di equival + + + align:start position:0% +metric ton of carbon di equival +you can see that in almost every case + + align:start position:0% +you can see that in almost every case + + + align:start position:0% +you can see that in almost every case +everything is cheaper than letting + + align:start position:0% +everything is cheaper than letting + + + align:start position:0% +everything is cheaper than letting +greenhouse gas emissions continue + + align:start position:0% +greenhouse gas emissions continue + + + align:start position:0% +greenhouse gas emissions continue +unchecked or everything is cheaper than + + align:start position:0% +unchecked or everything is cheaper than + + + align:start position:0% +unchecked or everything is cheaper than +climate change so from a social cost to + + align:start position:0% +climate change so from a social cost to + + + align:start position:0% +climate change so from a social cost to +car perspective we should just make all + + align:start position:0% +car perspective we should just make all + + + align:start position:0% +car perspective we should just make all +these Transportation efforts as soon as + + align:start position:0% +these Transportation efforts as soon as + + + align:start position:0% +these Transportation efforts as soon as +possible and of course at the maximum + + align:start position:0% +possible and of course at the maximum + + + align:start position:0% +possible and of course at the maximum +level you can see that the maximum level + + align:start position:0% +level you can see that the maximum level + + + align:start position:0% +level you can see that the maximum level +some things I think that's Incident + + align:start position:0% +some things I think that's Incident + + + align:start position:0% +some things I think that's Incident +Management is incredibly beneficial from + + align:start position:0% +Management is incredibly beneficial from + + + align:start position:0% +Management is incredibly beneficial from +a cost perspective and a greenhouse Gap + + align:start position:0% +a cost perspective and a greenhouse Gap + + + align:start position:0% +a cost perspective and a greenhouse Gap +Val perspective but pretty much + + align:start position:0% +Val perspective but pretty much + + + align:start position:0% +Val perspective but pretty much +everything else here is small and the + + align:start position:0% +everything else here is small and the + + + align:start position:0% +everything else here is small and the +point is at the maximum level everything + + align:start position:0% +point is at the maximum level everything + + + align:start position:0% +point is at the maximum level everything +is less than social cost toart again a + + align:start position:0% +is less than social cost toart again a + + + align:start position:0% +is less than social cost toart again a +good argument for trying to reduce + + align:start position:0% +good argument for trying to reduce + + + align:start position:0% +good argument for trying to reduce +greenos gas emissions + + align:start position:0% +greenos gas emissions + + + align:start position:0% +greenos gas emissions +anyways just to bring us back to the + + align:start position:0% +anyways just to bring us back to the + + + align:start position:0% +anyways just to bring us back to the +Daniel Sperling identity I said before + + align:start position:0% +Daniel Sperling identity I said before + + + align:start position:0% +Daniel Sperling identity I said before +this is I want to highlight the + + align:start position:0% +this is I want to highlight the + + + align:start position:0% +this is I want to highlight the +different parts of the system and how to + + align:start position:0% +different parts of the system and how to + + + align:start position:0% +different parts of the system and how to +break down system there's Mobility the + + align:start position:0% +break down system there's Mobility the + + + align:start position:0% +break down system there's Mobility the +demand we have for transportation + + align:start position:0% +demand we have for transportation + + + align:start position:0% +demand we have for transportation +vehicle miles traveled there's the + + align:start position:0% +vehicle miles traveled there's the + + + align:start position:0% +vehicle miles traveled there's the +vehicle Energy Efficiency and there's + + align:start position:0% +vehicle Energy Efficiency and there's + + + align:start position:0% +vehicle Energy Efficiency and there's +the carbon intensity of the energy + + align:start position:0% +the carbon intensity of the energy + + + align:start position:0% +the carbon intensity of the energy +itself re has gas emissions per unit of + + align:start position:0% +itself re has gas emissions per unit of + + + align:start position:0% +itself re has gas emissions per unit of +energy and that is what gives us greenos + + align:start position:0% +energy and that is what gives us greenos + + + align:start position:0% +energy and that is what gives us greenos +gas emissions the reason why I say that + + align:start position:0% +gas emissions the reason why I say that + + + align:start position:0% +gas emissions the reason why I say that +is because if you look at the existing + + align:start position:0% +is because if you look at the existing + + + align:start position:0% +is because if you look at the existing +sanki diagram you can see that in the US + + align:start position:0% +sanki diagram you can see that in the US + + + align:start position:0% +sanki diagram you can see that in the US +now we have a very small fraction of + + align:start position:0% +now we have a very small fraction of + + + align:start position:0% +now we have a very small fraction of +hydrogen production and almost entirely + + align:start position:0% +hydrogen production and almost entirely + + + align:start position:0% +hydrogen production and almost entirely +goes to Industry almost all of our + + align:start position:0% +goes to Industry almost all of our + + + align:start position:0% +goes to Industry almost all of our +transportation energy comes from liquid + + align:start position:0% +transportation energy comes from liquid + + + align:start position:0% +transportation energy comes from liquid +fuels petroleum and petroleum + + align:start position:0% +fuels petroleum and petroleum + + + align:start position:0% +fuels petroleum and petroleum +sources but if we want to reach a fully + + align:start position:0% +sources but if we want to reach a fully + + + align:start position:0% +sources but if we want to reach a fully +decarbonized economy this is the + + align:start position:0% +decarbonized economy this is the + + + align:start position:0% +decarbonized economy this is the +Williams 2020 paper for 100% renewable + + align:start position:0% +Williams 2020 paper for 100% renewable + + + align:start position:0% +Williams 2020 paper for 100% renewable +energy Matrix it basically forecast that + + align:start position:0% +energy Matrix it basically forecast that + + + align:start position:0% +energy Matrix it basically forecast that +Transportation will come from liquid + + align:start position:0% +Transportation will come from liquid + + + align:start position:0% +Transportation will come from liquid +fuels that are derived from originally + + align:start position:0% +fuels that are derived from originally + + + align:start position:0% +fuels that are derived from originally +from hydrogen and from that hydrogen or + + align:start position:0% +from hydrogen and from that hydrogen or + + + align:start position:0% +from hydrogen and from that hydrogen or +renewable resources like solar and wind + + align:start position:0% +renewable resources like solar and wind + + + align:start position:0% +renewable resources like solar and wind +how are we going to get there and what + + align:start position:0% +how are we going to get there and what + + + align:start position:0% +how are we going to get there and what +does that mean the MIT team led by + + align:start position:0% +does that mean the MIT team led by + + + align:start position:0% +does that mean the MIT team led by +Steven Barrett and in AO Astro and Bill + + align:start position:0% +Steven Barrett and in AO Astro and Bill + + + align:start position:0% +Steven Barrett and in AO Astro and Bill +Green in chemical engineering put + + align:start position:0% +Green in chemical engineering put + + + align:start position:0% +Green in chemical engineering put +together a proposal for the climate + + align:start position:0% +together a proposal for the climate + + + align:start position:0% +together a proposal for the climate +Grand Challenge that called the tough + + align:start position:0% +Grand Challenge that called the tough + + + align:start position:0% +Grand Challenge that called the tough +decarbonize Transportation initiative in + + align:start position:0% +decarbonize Transportation initiative in + + + align:start position:0% +decarbonize Transportation initiative in +2021 and the key finding from these + + align:start position:0% +2021 and the key finding from these + + + align:start position:0% +2021 and the key finding from these +system engineers and from these chemical + + align:start position:0% +system engineers and from these chemical + + + align:start position:0% +system engineers and from these chemical +Engineers was that we're going to need + + align:start position:0% +Engineers was that we're going to need + + + align:start position:0% +Engineers was that we're going to need +new vehicles new fuels and entirely new + + align:start position:0% +new vehicles new fuels and entirely new + + + align:start position:0% +new vehicles new fuels and entirely new +hydrogen system in order of decarbonized + + align:start position:0% +hydrogen system in order of decarbonized + + + align:start position:0% +hydrogen system in order of decarbonized +transportation for low greenhouse gas + + align:start position:0% +transportation for low greenhouse gas + + + align:start position:0% +transportation for low greenhouse gas +carbon based fuels the main challenge is + + align:start position:0% +carbon based fuels the main challenge is + + + align:start position:0% +carbon based fuels the main challenge is +the huge scale of fuel production needed + + align:start position:0% +the huge scale of fuel production needed + + + align:start position:0% +the huge scale of fuel production needed +all of our low greenhouse gas fuel + + align:start position:0% +all of our low greenhouse gas fuel + + + align:start position:0% +all of our low greenhouse gas fuel +options even biofuels depend on a huge + + align:start position:0% +options even biofuels depend on a huge + + + align:start position:0% +options even biofuels depend on a huge +scale production of low greenhous gas + + align:start position:0% +scale production of low greenhous gas + + + align:start position:0% +scale production of low greenhous gas +hydrogen and the cost of low greenhous + + align:start position:0% +hydrogen and the cost of low greenhous + + + align:start position:0% +hydrogen and the cost of low greenhous +gas hydrogen is often largest part of + + align:start position:0% +gas hydrogen is often largest part of + + + align:start position:0% +gas hydrogen is often largest part of +the cost of the finished low gas gas + + align:start position:0% +the cost of the finished low gas gas + + + align:start position:0% +the cost of the finished low gas gas +emitting + + align:start position:0% +emitting + + + align:start position:0% +emitting +Fuel and they find a number of key + + align:start position:0% +Fuel and they find a number of key + + + align:start position:0% +Fuel and they find a number of key +findings in the executive summary first + + align:start position:0% +findings in the executive summary first + + + align:start position:0% +findings in the executive summary first +longdistance vehicles in the tough to + + align:start position:0% +longdistance vehicles in the tough to + + + align:start position:0% +longdistance vehicles in the tough to +decarbonized Transportation sectors + + align:start position:0% +decarbonized Transportation sectors + + + align:start position:0% +decarbonized Transportation sectors +Aviation shipping and trucks all those + + align:start position:0% +Aviation shipping and trucks all those + + + align:start position:0% +Aviation shipping and trucks all those +long-distance Vehicles carry their own + + align:start position:0% +long-distance Vehicles carry their own + + + align:start position:0% +long-distance Vehicles carry their own +energy so the energy density is crucial + + align:start position:0% +energy so the energy density is crucial + + + align:start position:0% +energy so the energy density is crucial +the more weight and more volume of a + + align:start position:0% +the more weight and more volume of a + + + align:start position:0% +the more weight and more volume of a +fuel or battery you carry reduces the + + align:start position:0% +fuel or battery you carry reduces the + + + align:start position:0% +fuel or battery you carry reduces the +payload VI for the vehicle which is the + + align:start position:0% +payload VI for the vehicle which is the + + + align:start position:0% +payload VI for the vehicle which is the +purpose of the trip in and of itself the + + align:start position:0% +purpose of the trip in and of itself the + + + align:start position:0% +purpose of the trip in and of itself the +Alternatives we have hydrocarbons are + + align:start position:0% +Alternatives we have hydrocarbons are + + + align:start position:0% +Alternatives we have hydrocarbons are +two to 30 times heavier and require + + align:start position:0% +two to 30 times heavier and require + + + align:start position:0% +two to 30 times heavier and require +greater + + align:start position:0% +greater + + + align:start position:0% +greater +volumes they also point out a major + + align:start position:0% +volumes they also point out a major + + + align:start position:0% +volumes they also point out a major +challenge is going to be the scale of + + align:start position:0% +challenge is going to be the scale of + + + align:start position:0% +challenge is going to be the scale of +achieving this fuel infrastructure today + + align:start position:0% +achieving this fuel infrastructure today + + + align:start position:0% +achieving this fuel infrastructure today +only fossil fuels are available at the + + align:start position:0% +only fossil fuels are available at the + + + align:start position:0% +only fossil fuels are available at the +huge scale needed about a billion tons + + align:start position:0% +huge scale needed about a billion tons + + + align:start position:0% +huge scale needed about a billion tons +per year and realistically only a few + + align:start position:0% +per year and realistically only a few + + + align:start position:0% +per year and realistically only a few +low carbon alternatives to reach needed + + align:start position:0% +low carbon alternatives to reach needed + + + align:start position:0% +low carbon alternatives to reach needed +scale by + + align:start position:0% +scale by + + + align:start position:0% +scale by +2050 existing vehicles are all designed + + align:start position:0% +2050 existing vehicles are all designed + + + align:start position:0% +2050 existing vehicles are all designed +to use hydrocarbon fuels so we either + + align:start position:0% +to use hydrocarbon fuels so we either + + + align:start position:0% +to use hydrocarbon fuels so we either +need a carbon fuel that doesn't increase + + align:start position:0% +need a carbon fuel that doesn't increase + + + align:start position:0% +need a carbon fuel that doesn't increase +P gas emissions a quote unquote drop + + align:start position:0% +P gas emissions a quote unquote drop + + + align:start position:0% +P gas emissions a quote unquote drop +Fuel and we make a liquid fuel like + + align:start position:0% +Fuel and we make a liquid fuel like + + + align:start position:0% +Fuel and we make a liquid fuel like +gasoline from renewable resources like + + align:start position:0% +gasoline from renewable resources like + + + align:start position:0% +gasoline from renewable resources like +solar and wind instead of pulling it out + + align:start position:0% +solar and wind instead of pulling it out + + + align:start position:0% +solar and wind instead of pulling it out +of the ground and we're also going to + + align:start position:0% +of the ground and we're also going to + + + align:start position:0% +of the ground and we're also going to +need new vehicles or we need new + + align:start position:0% +need new vehicles or we need new + + + align:start position:0% +need new vehicles or we need new +vehicles to use new fuels those vehicle + + align:start position:0% +vehicles to use new fuels those vehicle + + + align:start position:0% +vehicles to use new fuels those vehicle +lifetimes are long 20 to 30 years and + + align:start position:0% +lifetimes are long 20 to 30 years and + + + align:start position:0% +lifetimes are long 20 to 30 years and +new vehicle development is very slow so + + align:start position:0% +new vehicle development is very slow so + + + align:start position:0% +new vehicle development is very slow so +if we want to achieve decarbonization by + + align:start position:0% +if we want to achieve decarbonization by + + + align:start position:0% +if we want to achieve decarbonization by +2050 we need to start develop the new + + align:start position:0% +2050 we need to start develop the new + + + align:start position:0% +2050 we need to start develop the new +vehicles now the good news as you know + + align:start position:0% +vehicles now the good news as you know + + + align:start position:0% +vehicles now the good news as you know +from the news we have many new vehicles + + align:start position:0% +from the news we have many new vehicles + + + align:start position:0% +from the news we have many new vehicles +many new uh trucks being developed now + + align:start position:0% +many new uh trucks being developed now + + + align:start position:0% +many new uh trucks being developed now +we probably arguably have fewer options + + align:start position:0% +we probably arguably have fewer options + + + align:start position:0% +we probably arguably have fewer options +for shipping and Aviation though + + align:start position:0% +for shipping and Aviation though + + + align:start position:0% +for shipping and Aviation though +shipping is one sector that seems to be + + align:start position:0% +shipping is one sector that seems to be + + + align:start position:0% +shipping is one sector that seems to be +quite engaged in reducing its greenhouse + + align:start position:0% +quite engaged in reducing its greenhouse + + + align:start position:0% +quite engaged in reducing its greenhouse +gas emissions the cost of the fuel + + align:start position:0% +gas emissions the cost of the fuel + + + align:start position:0% +gas emissions the cost of the fuel +itself is a significant part of the + + align:start position:0% +itself is a significant part of the + + + align:start position:0% +itself is a significant part of the +total cost of transportation services + + align:start position:0% +total cost of transportation services + + + align:start position:0% +total cost of transportation services +this the fuels for the sector currently + + align:start position:0% +this the fuels for the sector currently + + + align:start position:0% +this the fuels for the sector currently +cost about a trillion dollars per year + + align:start position:0% +cost about a trillion dollars per year + + + align:start position:0% +cost about a trillion dollars per year +and expensive infrastructure adds + + align:start position:0% +and expensive infrastructure adds + + + align:start position:0% +and expensive infrastructure adds +additional cost so if we want to build a + + align:start position:0% +additional cost so if we want to build a + + + align:start position:0% +additional cost so if we want to build a +new fuel infrastructure we're going to + + align:start position:0% +new fuel infrastructure we're going to + + + align:start position:0% +new fuel infrastructure we're going to +need new infrastructure and we're going + + align:start position:0% +need new infrastructure and we're going + + + align:start position:0% +need new infrastructure and we're going +to have to achieve that on a toost + + align:start position:0% +to have to achieve that on a toost + + + align:start position:0% +to have to achieve that on a toost +competitive basis + + align:start position:0% +competitive basis + + + align:start position:0% +competitive basis +and of course there's the practicalities + + align:start position:0% +and of course there's the practicalities + + + align:start position:0% +and of course there's the practicalities +of fuel instructor room temperature + + align:start position:0% +of fuel instructor room temperature + + + align:start position:0% +of fuel instructor room temperature +liquids are much easier to distribute + + align:start position:0% +liquids are much easier to distribute + + + align:start position:0% +liquids are much easier to distribute +and store than gases or solids fast + + align:start position:0% +and store than gases or solids fast + + + align:start position:0% +and store than gases or solids fast +refueling and recharging is important + + align:start position:0% +refueling and recharging is important + + + align:start position:0% +refueling and recharging is important +for some vehicles and a very practical + + align:start position:0% +for some vehicles and a very practical + + + align:start position:0% +for some vehicles and a very practical +level that new fuel has to be available + + align:start position:0% +level that new fuel has to be available + + + align:start position:0% +level that new fuel has to be available +at 800 ports 177,000 airports and more + + align:start position:0% +at 800 ports 177,000 airports and more + + + align:start position:0% +at 800 ports 177,000 airports and more +than 100,000 truck stops in the + + align:start position:0% +than 100,000 truck stops in the + + + align:start position:0% +than 100,000 truck stops in the +US another summary slide from these + + align:start position:0% +US another summary slide from these + + + align:start position:0% +US another summary slide from these +sectors that this team identified as + + align:start position:0% +sectors that this team identified as + + + align:start position:0% +sectors that this team identified as +tough to decarbonize trucking shipping + + align:start position:0% +tough to decarbonize trucking shipping + + + align:start position:0% +tough to decarbonize trucking shipping +and Aviation they all constit about one + + align:start position:0% +and Aviation they all constit about one + + + align:start position:0% +and Aviation they all constit about one +to one 1.25 gigatons per year that's + + align:start position:0% +to one 1.25 gigatons per year that's + + + align:start position:0% +to one 1.25 gigatons per year that's +about 3.25 gigatons a year about one10 + + align:start position:0% +about 3.25 gigatons a year about one10 + + + align:start position:0% +about 3.25 gigatons a year about one10 +of all of the greous gas emissions for + + align:start position:0% +of all of the greous gas emissions for + + + align:start position:0% +of all of the greous gas emissions for +the world you can see that all these + + align:start position:0% +the world you can see that all these + + + align:start position:0% +the world you can see that all these +vehicles have very different vehicle + + align:start position:0% +vehicles have very different vehicle + + + align:start position:0% +vehicles have very different vehicle +intensity of greenhous gas emissions per + + align:start position:0% +intensity of greenhous gas emissions per + + + align:start position:0% +intensity of greenhous gas emissions per +use the engines themselves are different + + align:start position:0% +use the engines themselves are different + + + align:start position:0% +use the engines themselves are different +they use different fuels and they have + + align:start position:0% +they use different fuels and they have + + + align:start position:0% +they use different fuels and they have +very different power requirements it + + align:start position:0% +very different power requirements it + + + align:start position:0% +very different power requirements it +requires a lot more power to lift a + + align:start position:0% +requires a lot more power to lift a + + + align:start position:0% +requires a lot more power to lift a +plane into the air than it does to move + + align:start position:0% +plane into the air than it does to move + + + align:start position:0% +plane into the air than it does to move +a truck along a road or ship through + + align:start position:0% +a truck along a road or ship through + + + align:start position:0% +a truck along a road or ship through +water + + align:start position:0% +water + + + align:start position:0% +water +the state of electrification is that + + align:start position:0% +the state of electrification is that + + + align:start position:0% +the state of electrification is that +Trucking we can achieve at relatively + + align:start position:0% +Trucking we can achieve at relatively + + + align:start position:0% +Trucking we can achieve at relatively +high cost it looks very challenging for + + align:start position:0% +high cost it looks very challenging for + + + align:start position:0% +high cost it looks very challenging for +shipping and for Aviation and space been + + align:start position:0% +shipping and for Aviation and space been + + + align:start position:0% +shipping and for Aviation and space been +deemed barely impossible over large + + align:start position:0% +deemed barely impossible over large + + + align:start position:0% +deemed barely impossible over large +distances because the batteries + + align:start position:0% +distances because the batteries + + + align:start position:0% +distances because the batteries +themselves weigh so much they would + + align:start position:0% +themselves weigh so much they would + + + align:start position:0% +themselves weigh so much they would +displace the passengers or simply way + + align:start position:0% +displace the passengers or simply way + + + align:start position:0% +displace the passengers or simply way +too much for the plane at all fuel cell + + align:start position:0% +too much for the plane at all fuel cell + + + align:start position:0% +too much for the plane at all fuel cell +options where we use a chemical battery + + align:start position:0% +options where we use a chemical battery + + + align:start position:0% +options where we use a chemical battery +a relatively high cost for Trucking and + + align:start position:0% +a relatively high cost for Trucking and + + + align:start position:0% +a relatively high cost for Trucking and +shipping not possible for Aviation if + + align:start position:0% +shipping not possible for Aviation if + + + align:start position:0% +shipping not possible for Aviation if +you summarize these things we have a few + + align:start position:0% +you summarize these things we have a few + + + align:start position:0% +you summarize these things we have a few +different viable path ways that we have + + align:start position:0% +different viable path ways that we have + + + align:start position:0% +different viable path ways that we have +to focus in on we have many different + + align:start position:0% +to focus in on we have many different + + + align:start position:0% +to focus in on we have many different +viable Pathways for Trucking we have a + + align:start position:0% +viable Pathways for Trucking we have a + + + align:start position:0% +viable Pathways for Trucking we have a +few options for shpping carbon based + + align:start position:0% +few options for shpping carbon based + + + align:start position:0% +few options for shpping carbon based +fuels ammonia or hydrogen and for + + align:start position:0% +fuels ammonia or hydrogen and for + + + align:start position:0% +fuels ammonia or hydrogen and for +Aviation we need the energy density of + + align:start position:0% +Aviation we need the energy density of + + + align:start position:0% +Aviation we need the energy density of +carbon based fuels they have low weight + + align:start position:0% +carbon based fuels they have low weight + + + align:start position:0% +carbon based fuels they have low weight +and low volume compared to how much + + align:start position:0% +and low volume compared to how much + + + align:start position:0% +and low volume compared to how much +energy carbon based fuel packed in so we + + align:start position:0% +energy carbon based fuel packed in so we + + + align:start position:0% +energy carbon based fuel packed in so we +need to think about Aviation fuels that + + align:start position:0% +need to think about Aviation fuels that + + + align:start position:0% +need to think about Aviation fuels that +will be low carbon in order to continue + + align:start position:0% +will be low carbon in order to continue + + + align:start position:0% +will be low carbon in order to continue +flying this is to point out that again + + align:start position:0% +flying this is to point out that again + + + align:start position:0% +flying this is to point out that again +if you look at the moving cooler report + + align:start position:0% +if you look at the moving cooler report + + + align:start position:0% +if you look at the moving cooler report +you look at these tough to decarbonized + + align:start position:0% +you look at these tough to decarbonized + + + align:start position:0% +you look at these tough to decarbonized +Transportation sectors urban planners + + align:start position:0% +Transportation sectors urban planners + + + align:start position:0% +Transportation sectors urban planners +can do a lot they have jurisdiction they + + align:start position:0% +can do a lot they have jurisdiction they + + + align:start position:0% +can do a lot they have jurisdiction they +have authority to help plan new + + align:start position:0% +have authority to help plan new + + + align:start position:0% +have authority to help plan new +infrastructure they have authority to + + align:start position:0% +infrastructure they have authority to + + + align:start position:0% +infrastructure they have authority to +plan great infrastructure which we don't + + align:start position:0% +plan great infrastructure which we don't + + + align:start position:0% +plan great infrastructure which we don't +look at very often but I would argue to + + align:start position:0% +look at very often but I would argue to + + + align:start position:0% +look at very often but I would argue to +you that this is kind of an unexplored + + align:start position:0% +you that this is kind of an unexplored + + + align:start position:0% +you that this is kind of an unexplored +area for urban planners to try to affect \ No newline at end of file diff --git a/r_AGxxITsbQ.txt b/r_AGxxITsbQ.txt new file mode 100644 index 0000000000000000000000000000000000000000..7898c2fa7e773c2e686cdd597d76877bf7578754 --- /dev/null +++ b/r_AGxxITsbQ.txt @@ -0,0 +1,10659 @@ +align:start position:0% + +So now uh let's let's talk about the uh + + align:start position:0% +So now uh let's let's talk about the uh + + + align:start position:0% +So now uh let's let's talk about the uh +let's talk about first the different uh + + align:start position:0% +let's talk about first the different uh + + + align:start position:0% +let's talk about first the different uh +concepts uh that we have talked about in + + align:start position:0% +concepts uh that we have talked about in + + + align:start position:0% +concepts uh that we have talked about in +class and then get and then in the end + + align:start position:0% +class and then get and then in the end + + + align:start position:0% +class and then get and then in the end +I'll get to just some example of some + + align:start position:0% +I'll get to just some example of some + + + align:start position:0% +I'll get to just some example of some +problems that you might face on the mid. + + align:start position:0% +problems that you might face on the mid. + + + align:start position:0% +problems that you might face on the mid. +So the first is this that if you take a + + align:start position:0% +So the first is this that if you take a + + + align:start position:0% +So the first is this that if you take a +subset + + align:start position:0% +subset + + + align:start position:0% +subset +of Rn uh to say that a is bounded from + + align:start position:0% +of Rn uh to say that a is bounded from + + + align:start position:0% +of Rn uh to say that a is bounded from +above. + + align:start position:0% + + + + align:start position:0% + +This just means that there exist + + align:start position:0% + + + + align:start position:0% + +m such that for all + + align:start position:0% + + + + align:start position:0% + +a in a a here is less than equal to a. + + align:start position:0% +a in a a here is less than equal to a. + + + align:start position:0% +a in a a here is less than equal to a. +This is what it means to be bounded from + + align:start position:0% +This is what it means to be bounded from + + + align:start position:0% +This is what it means to be bounded from +about from a subset, right? And now the + + align:start position:0% +about from a subset, right? And now the + + + align:start position:0% +about from a subset, right? And now the +there's a list of about + + align:start position:0% + + + + align:start position:0% + +um this is a number uh so so m here is a + + align:start position:0% +um this is a number uh so so m here is a + + + align:start position:0% +um this is a number uh so so m here is a +least + + align:start position:0% +least + + + align:start position:0% +least +so m + + align:start position:0% + + + + align:start position:0% + +is a least upper bound. + + align:start position:0% + + + + align:start position:0% + +If + + align:start position:0% +If + + + align:start position:0% +If +uh um if uh m is an upper bound + + align:start position:0% + + + + align:start position:0% + +and any other + + align:start position:0% + + + + align:start position:0% + +bound + + align:start position:0% + + + + align:start position:0% + +let's call it m + + align:start position:0% +let's call it m + + + align:start position:0% +let's call it m +uh uh is + + align:start position:0% +uh uh is + + + align:start position:0% +uh uh is +bigger equal + + align:start position:0% +bigger equal + + + align:start position:0% +bigger equal +to it. So this is what it means to be a + + align:start position:0% +to it. So this is what it means to be a + + + align:start position:0% +to it. So this is what it means to be a +least up + + align:start position:0% +least up + + + align:start position:0% +least up +and so the least up bounds. So so the + + align:start position:0% +and so the least up bounds. So so the + + + align:start position:0% +and so the least up bounds. So so the +least upper bounds is this is what we + + align:start position:0% +least upper bounds is this is what we + + + align:start position:0% +least upper bounds is this is what we +denote by super. + + align:start position:0% + + + + align:start position:0% + +Okay. And similarly, similarly form + + align:start position:0% + + + + align:start position:0% + +for lower bound + + align:start position:0% + + + + align:start position:0% + +and uh and in + + align:start position:0% +and uh and in + + + align:start position:0% +and uh and in +right and the real numbers have this + + align:start position:0% +right and the real numbers have this + + + align:start position:0% +right and the real numbers have this +property that if I set this bounded from + + align:start position:0% +property that if I set this bounded from + + + align:start position:0% +property that if I set this bounded from +above then it has a then there is a + + align:start position:0% +above then it has a then there is a + + + align:start position:0% +above then it has a then there is a +least upper bound. + + align:start position:0% +least upper bound. + + + align:start position:0% +least upper bound. +uh and likewise for uh assets that is + + align:start position:0% +uh and likewise for uh assets that is + + + align:start position:0% +uh and likewise for uh assets that is +below. + + align:start position:0% +below. + + + align:start position:0% +below. +Okay, so that was soup and we'll get to + + align:start position:0% +Okay, so that was soup and we'll get to + + + align:start position:0% +Okay, so that was soup and we'll get to +this mean soup and make uh I'll just + + align:start position:0% +this mean soup and make uh I'll just + + + align:start position:0% +this mean soup and make uh I'll just +review that a little bit later also. + + align:start position:0% +review that a little bit later also. + + + align:start position:0% +review that a little bit later also. +Uh but that's another important thing. + + align:start position:0% +Uh but that's another important thing. + + + align:start position:0% +Uh but that's another important thing. +Uh a sequence. So another key uh concept + + align:start position:0% +Uh a sequence. So another key uh concept + + + align:start position:0% +Uh a sequence. So another key uh concept +in this class is sequence + + align:start position:0% +in this class is sequence + + + align:start position:0% +in this class is sequence +and we let's begin with a sequence of + + align:start position:0% +and we let's begin with a sequence of + + + align:start position:0% +and we let's begin with a sequence of +real numbers. + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +So this is a map + + align:start position:0% +So this is a map + + + align:start position:0% +So this is a map +from the + + align:start position:0% +from the + + + align:start position:0% +from the +positive integers + + align:start position:0% +positive integers + + + align:start position:0% +positive integers +into + + align:start position:0% + + + + align:start position:0% + +and again it denotes so the image. So if + + align:start position:0% +and again it denotes so the image. So if + + + align:start position:0% +and again it denotes so the image. So if +you're looking at uh the image of some n + + align:start position:0% +you're looking at uh the image of some n + + + align:start position:0% +you're looking at uh the image of some n +we typically denote this by a n or by a + + align:start position:0% +we typically denote this by a n or by a + + + align:start position:0% +we typically denote this by a n or by a +n or xn or something like that + + align:start position:0% +n or xn or something like that + + + align:start position:0% +n or xn or something like that +where we use the subscript + + align:start position:0% +where we use the subscript + + + align:start position:0% +where we use the subscript +but it's just the image under this map. + + align:start position:0% +but it's just the image under this map. + + + align:start position:0% +but it's just the image under this map. +So that's a sequence. So for each + + align:start position:0% +So that's a sequence. So for each + + + align:start position:0% +So that's a sequence. So for each +positive integer you get a real number. + + align:start position:0% +positive integer you get a real number. + + + align:start position:0% +positive integer you get a real number. +Then um + + align:start position:0% + + + + align:start position:0% + +then for a sequence one of the first + + align:start position:0% +then for a sequence one of the first + + + align:start position:0% +then for a sequence one of the first +things you are interested in is + + align:start position:0% +things you are interested in is + + + align:start position:0% +things you are interested in is +convergence. + + align:start position:0% + + + + align:start position:0% + +So if you have so if this here is a + + align:start position:0% +So if you have so if this here is a + + + align:start position:0% +So if you have so if this here is a +sequence + + align:start position:0% +sequence + + + align:start position:0% +sequence +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +that xn converts to some x here. This + + align:start position:0% +that xn converts to some x here. This + + + align:start position:0% +that xn converts to some x here. This +here just means + + align:start position:0% + + + + align:start position:0% + +for all + + align:start position:0% + + + + align:start position:0% + +uh epsilon greater than zero they exist. + + align:start position:0% +uh epsilon greater than zero they exist. + + + align:start position:0% +uh epsilon greater than zero they exist. +I I will use this symbol. I haven't used + + align:start position:0% +I I will use this symbol. I haven't used + + + align:start position:0% +I I will use this symbol. I haven't used +it until now but it's so hard not to use + + align:start position:0% +it until now but it's so hard not to use + + + align:start position:0% +it until now but it's so hard not to use +it. This means they exist. + + align:start position:0% +it. This means they exist. + + + align:start position:0% +it. This means they exist. +It's not on + + align:start position:0% +It's not on + + + align:start position:0% +It's not on +but it's a totally standard symbol. So + + align:start position:0% +but it's a totally standard symbol. So + + + align:start position:0% +but it's a totally standard symbol. So +they exist. + + align:start position:0% +they exist. + + + align:start position:0% +they exist. +uh capital n such that + + align:start position:0% +uh capital n such that + + + align:start position:0% +uh capital n such that +if little n is bigger equal to capital n + + align:start position:0% +if little n is bigger equal to capital n + + + align:start position:0% +if little n is bigger equal to capital n +then uh xn - x + + align:start position:0% +then uh xn - x + + + align:start position:0% +then uh xn - x +small. + + align:start position:0% +small. + + + align:start position:0% +small. +So this is what it means for a sequence + + align:start position:0% +So this is what it means for a sequence + + + align:start position:0% +So this is what it means for a sequence +to convert + + align:start position:0% +to convert + + + align:start position:0% +to convert +to x sequence x to convert to x and you + + align:start position:0% +to x sequence x to convert to x and you + + + align:start position:0% +to x sequence x to convert to x and you +write like this or you can write xn and + + align:start position:0% +write like this or you can write xn and + + + align:start position:0% +write like this or you can write xn and +then the limit here as n go to infinity= + + align:start position:0% +then the limit here as n go to infinity= + + + align:start position:0% +then the limit here as n go to infinity= +both of these + + align:start position:0% +both of these + + + align:start position:0% +both of these +are standard use. + + align:start position:0% +are standard use. + + + align:start position:0% +are standard use. +So and then also if a seage is not + + align:start position:0% +So and then also if a seage is not + + + align:start position:0% +So and then also if a seage is not +convergent + + align:start position:0% + + + + align:start position:0% + +is not convergent + + align:start position:0% + + + + align:start position:0% + +then + + align:start position:0% +then + + + align:start position:0% +then +then we say + + align:start position:0% + + + + align:start position:0% + +is diver. + + align:start position:0% + + + + align:start position:0% + +So sequence is either convergent or it's + + align:start position:0% +So sequence is either convergent or it's + + + align:start position:0% +So sequence is either convergent or it's +divergent. + + align:start position:0% +divergent. + + + align:start position:0% +divergent. +Um and then you there's this + + align:start position:0% + + + + align:start position:0% + +property + + align:start position:0% +property + + + align:start position:0% +property +useful property. + + align:start position:0% +useful property. + + + align:start position:0% +useful property. +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +So a lema + + align:start position:0% + + + + align:start position:0% + +if x + + align:start position:0% +if x + + + align:start position:0% +if x +is convergent + + align:start position:0% + + + + align:start position:0% + +Then the set + + align:start position:0% +Then the set + + + align:start position:0% +Then the set +this as a set this here is a bounce set. + + align:start position:0% + + + + align:start position:0% + +Okay, we talk about that. + + align:start position:0% +Okay, we talk about that. + + + align:start position:0% +Okay, we talk about that. +And then another thing about sequences + + align:start position:0% +And then another thing about sequences + + + align:start position:0% +And then another thing about sequences +is that the algebraic processes + + align:start position:0% + + + + align:start position:0% + +of sequences + + align:start position:0% + + + + align:start position:0% + +and what are the algebraic properties + + align:start position:0% +and what are the algebraic properties + + + align:start position:0% +and what are the algebraic properties +they are that if you take two sequences + + align:start position:0% +they are that if you take two sequences + + + align:start position:0% +they are that if you take two sequences +a n and bn and let's say that a n + + align:start position:0% +a n and bn and let's say that a n + + + align:start position:0% +a n and bn and let's say that a n +converts to a and bn convert to b then + + align:start position:0% +converts to a and bn convert to b then + + + align:start position:0% +converts to a and bn convert to b then +the algebraic and c and c is just a + + align:start position:0% +the algebraic and c and c is just a + + + align:start position:0% +the algebraic and c and c is just a +constant + + align:start position:0% + + + + align:start position:0% + +Then you have that sort of and often + + align:start position:0% +Then you have that sort of and often + + + align:start position:0% +Then you have that sort of and often +when you combine what I did there is one + + align:start position:0% +when you combine what I did there is one + + + align:start position:0% +when you combine what I did there is one +and two before you combine you're + + align:start position:0% +and two before you combine you're + + + align:start position:0% +and two before you combine you're +looking at a n + c * bn this here + + align:start position:0% +looking at a n + c * bn this here + + + align:start position:0% +looking at a n + c * bn this here +converts to a c * b + + align:start position:0% +converts to a c * b + + + align:start position:0% +converts to a c * b +this is the first and this when I state + + align:start position:0% +this is the first and this when I state + + + align:start position:0% +this is the first and this when I state +it like this it actually combine two of + + align:start position:0% +it like this it actually combine two of + + + align:start position:0% +it like this it actually combine two of +the one properties that we talked about + + align:start position:0% +the one properties that we talked about + + + align:start position:0% +the one properties that we talked about +earlier + + align:start position:0% +earlier + + + align:start position:0% +earlier +uh the second one is that a n * B n will + + align:start position:0% +uh the second one is that a n * B n will + + + align:start position:0% +uh the second one is that a n * B n will +converge to a * b. + + align:start position:0% +converge to a * b. + + + align:start position:0% +converge to a * b. +Third property is that if uh if a n if + + align:start position:0% +Third property is that if uh if a n if + + + align:start position:0% +Third property is that if uh if a n if +these here are not equal to zero and the + + align:start position:0% +these here are not equal to zero and the + + + align:start position:0% +these here are not equal to zero and the +limit here is not equal to zero then 1 / + + align:start position:0% +limit here is not equal to zero then 1 / + + + align:start position:0% +limit here is not equal to zero then 1 / +a n converts to 1. + + align:start position:0% + + + + align:start position:0% + +And so of course this last one + + align:start position:0% +And so of course this last one + + + align:start position:0% +And so of course this last one +you know this one implies in particular + + align:start position:0% +you know this one implies in particular + + + align:start position:0% +you know this one implies in particular +of course that also bn / a n converse to + + align:start position:0% +of course that also bn / a n converse to + + + align:start position:0% +of course that also bn / a n converse to +b + + align:start position:0% +b + + + align:start position:0% +b +this is just because this property here + + align:start position:0% +this is just because this property here + + + align:start position:0% +this is just because this property here +combined with property two that will + + align:start position:0% +combined with property two that will + + + align:start position:0% +combined with property two that will +give you this + + align:start position:0% +give you this + + + align:start position:0% +give you this +okay so that's + + align:start position:0% +okay so that's + + + align:start position:0% +okay so that's +the algebraic properties uh of limits + + align:start position:0% +the algebraic properties uh of limits + + + align:start position:0% +the algebraic properties uh of limits +um then you have um the concept of a + + align:start position:0% +um then you have um the concept of a + + + align:start position:0% +um then you have um the concept of a +subsequence. + + align:start position:0% + + + + align:start position:0% + +So a subsequence. + + align:start position:0% + + + + align:start position:0% + +So we are imagining that we have a + + align:start position:0% +So we are imagining that we have a + + + align:start position:0% +So we are imagining that we have a +sequence and often we don't go all the + + align:start position:0% +sequence and often we don't go all the + + + align:start position:0% +sequence and often we don't go all the +way back like this but but a sequence + + align:start position:0% +way back like this but but a sequence + + + align:start position:0% +way back like this but but a sequence +again is is a map from the positive + + align:start position:0% +again is is a map from the positive + + + align:start position:0% +again is is a map from the positive +integer into R and we know the image of + + align:start position:0% +integer into R and we know the image of + + + align:start position:0% +integer into R and we know the image of +N like typically like Xn + + align:start position:0% +N like typically like Xn + + + align:start position:0% +N like typically like Xn +then a subsequence of this sequence and + + align:start position:0% +then a subsequence of this sequence and + + + align:start position:0% +then a subsequence of this sequence and +this is typically denoted something like + + align:start position:0% +this is typically denoted something like + + + align:start position:0% +this is typically denoted something like +this where you have a further subscript + + align:start position:0% +this where you have a further subscript + + + align:start position:0% +this where you have a further subscript +And this is and this is important again + + align:start position:0% +And this is and this is important again + + + align:start position:0% +And this is and this is important again +that this is like equal to f of g of k + + align:start position:0% +that this is like equal to f of g of k + + + align:start position:0% +that this is like equal to f of g of k +where g here and this is the really + + align:start position:0% +where g here and this is the really + + + align:start position:0% +where g here and this is the really +important property that g is a map from + + align:start position:0% +important property that g is a map from + + + align:start position:0% +important property that g is a map from +the positive integers into the positive + + align:start position:0% +the positive integers into the positive + + + align:start position:0% +the positive integers into the positive +integers and the really important is + + align:start position:0% +integers and the really important is + + + align:start position:0% +integers and the really important is +that g here is strictly increasing + + align:start position:0% + + + + align:start position:0% + +And so strictly increasing guarantee you + + align:start position:0% +And so strictly increasing guarantee you + + + align:start position:0% +And so strictly increasing guarantee you +that these numbers here is taken in the + + align:start position:0% +that these numbers here is taken in the + + + align:start position:0% +that these numbers here is taken in the +same order as in the original sequence + + align:start position:0% +same order as in the original sequence + + + align:start position:0% +same order as in the original sequence +but you may skip a bunch right I mean + + align:start position:0% +but you may skip a bunch right I mean + + + align:start position:0% +but you may skip a bunch right I mean +you know you take one and then you may + + align:start position:0% +you know you take one and then you may + + + align:start position:0% +you know you take one and then you may +skip a bunch and then you take another + + align:start position:0% +skip a bunch and then you take another + + + align:start position:0% +skip a bunch and then you take another +one and then you may skip more but it's + + align:start position:0% +one and then you may skip more but it's + + + align:start position:0% +one and then you may skip more but it's +in the same order and that's what + + align:start position:0% +in the same order and that's what + + + align:start position:0% +in the same order and that's what +increasing this guinea + + align:start position:0% +increasing this guinea + + + align:start position:0% +increasing this guinea +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +and and then you have + + align:start position:0% +and and then you have + + + align:start position:0% +and and then you have +then you have this property. + + align:start position:0% +then you have this property. + + + align:start position:0% +then you have this property. +So you have this theorem + + align:start position:0% +So you have this theorem + + + align:start position:0% +So you have this theorem +that a sequence xn is converged + + align:start position:0% + + + + align:start position:0% + +if and only if + + align:start position:0% + + + + align:start position:0% + +or all subsequences + + align:start position:0% + + + + align:start position:0% + +And one of these two was one of the two + + align:start position:0% +And one of these two was one of the two + + + align:start position:0% +And one of these two was one of the two +directions for this was trivial because + + align:start position:0% +directions for this was trivial because + + + align:start position:0% +directions for this was trivial because +if you have a um + + align:start position:0% +if you have a um + + + align:start position:0% +if you have a um +because because if you take a sequence + + align:start position:0% +because because if you take a sequence + + + align:start position:0% +because because if you take a sequence +then it is if you're thinking about this + + align:start position:0% +then it is if you're thinking about this + + + align:start position:0% +then it is if you're thinking about this +map here G as being the identity + + align:start position:0% +map here G as being the identity + + + align:start position:0% +map here G as being the identity +that's so that will give you a + + align:start position:0% +that's so that will give you a + + + align:start position:0% +that's so that will give you a +subsequence but that really is the + + align:start position:0% +subsequence but that really is the + + + align:start position:0% +subsequence but that really is the +original sequence, right? So the + + align:start position:0% +original sequence, right? So the + + + align:start position:0% +original sequence, right? So the +original sequence is a subsequence of + + align:start position:0% +original sequence is a subsequence of + + + align:start position:0% +original sequence is a subsequence of +itself. So if all subsequences are + + align:start position:0% +itself. So if all subsequences are + + + align:start position:0% +itself. So if all subsequences are +convergent, well then in particular the + + align:start position:0% +convergent, well then in particular the + + + align:start position:0% +convergent, well then in particular the +sequence itself is convergent. So one of + + align:start position:0% +sequence itself is convergent. So one of + + + align:start position:0% +sequence itself is convergent. So one of +those two directions was trivial. + + align:start position:0% +those two directions was trivial. + + + align:start position:0% +those two directions was trivial. +Okay. Now then we had these two theorems + + align:start position:0% +Okay. Now then we had these two theorems + + + align:start position:0% +Okay. Now then we had these two theorems +and they were right by then. So you know + + align:start position:0% +and they were right by then. So you know + + + align:start position:0% +and they were right by then. So you know +the like the sing the sort of the + + align:start position:0% +the like the sing the sort of the + + + align:start position:0% +the like the sing the sort of the +singing mathematics is a sinks built on + + align:start position:0% +singing mathematics is a sinks built on + + + align:start position:0% +singing mathematics is a sinks built on +each other right and hopefully like each + + align:start position:0% +each other right and hopefully like each + + + align:start position:0% +each other right and hopefully like each +step is fairly trivial but you build + + align:start position:0% +step is fairly trivial but you build + + + align:start position:0% +step is fairly trivial but you build +step by step and then you end up with + + align:start position:0% +step by step and then you end up with + + + align:start position:0% +step by step and then you end up with +something highly non-trivial right? So + + align:start position:0% +something highly non-trivial right? So + + + align:start position:0% +something highly non-trivial right? So +this here was was pretty trivial but + + align:start position:0% +this here was was pretty trivial but + + + align:start position:0% +this here was was pretty trivial but +then we used it later on to prove + + align:start position:0% +then we used it later on to prove + + + align:start position:0% +then we used it later on to prove +something + + align:start position:0% +something + + + align:start position:0% +something +non-trivial. So this was this model from + + align:start position:0% +non-trivial. So this was this model from + + + align:start position:0% +non-trivial. So this was this model from +convergence theorem + + align:start position:0% + + + + align:start position:0% + +and it has two there was two versions of + + align:start position:0% +and it has two there was two versions of + + + align:start position:0% +and it has two there was two versions of +this. you had a sequence xm + + align:start position:0% +this. you had a sequence xm + + + align:start position:0% +this. you had a sequence xm +and and xm was increasing. + + align:start position:0% +and and xm was increasing. + + + align:start position:0% +and and xm was increasing. +So that means that the next element is + + align:start position:0% +So that means that the next element is + + + align:start position:0% +So that means that the next element is +bigger equal to the previous element. If + + align:start position:0% +bigger equal to the previous element. If + + + align:start position:0% +bigger equal to the previous element. If +this here was the case, then XN is + + align:start position:0% +this here was the case, then XN is + + + align:start position:0% +this here was the case, then XN is +convergent + + align:start position:0% + + + + align:start position:0% + +if and only if + + align:start position:0% + + + + align:start position:0% + +uh XM is is bound. + + align:start position:0% +uh XM is is bound. + + + align:start position:0% +uh XM is is bound. +If the sequence is bound + + align:start position:0% +If the sequence is bound + + + align:start position:0% +If the sequence is bound +and uh the soup + + align:start position:0% +and uh the soup + + + align:start position:0% +and uh the soup +of the exam + + align:start position:0% +of the exam + + + align:start position:0% +of the exam +this here is is is + + align:start position:0% +this here is is is + + + align:start position:0% +this here is is is +the + + align:start position:0% + + + + align:start position:0% + +here is the + + align:start position:0% + + + + align:start position:0% + +second pro the second verse. of this is + + align:start position:0% +second pro the second verse. of this is + + + align:start position:0% +second pro the second verse. of this is +if you have a monot. So instead of being + + align:start position:0% +if you have a monot. So instead of being + + + align:start position:0% +if you have a monot. So instead of being +increasing it's now decreasing. So the + + align:start position:0% +increasing it's now decreasing. So the + + + align:start position:0% +increasing it's now decreasing. So the +next element is smaller equal to the + + align:start position:0% +next element is smaller equal to the + + + align:start position:0% +next element is smaller equal to the +previous element. + + align:start position:0% +previous element. + + + align:start position:0% +previous element. +And then similarly uh the sequence uh xn + + align:start position:0% +And then similarly uh the sequence uh xn + + + align:start position:0% +And then similarly uh the sequence uh xn +is convergent + + align:start position:0% + + + + align:start position:0% + +if and only if + + align:start position:0% + + + + align:start position:0% + +X is found from below + + align:start position:0% + + + + align:start position:0% + +below and in this case and if it is part + + align:start position:0% +below and in this case and if it is part + + + align:start position:0% +below and in this case and if it is part +from below then the limit here + + align:start position:0% +from below then the limit here + + + align:start position:0% +from below then the limit here +is of XN. + + align:start position:0% + + + + align:start position:0% + +Okay. So that was the monitor + + align:start position:0% +Okay. So that was the monitor + + + align:start position:0% +Okay. So that was the monitor +convergence there and it has these two + + align:start position:0% +convergence there and it has these two + + + align:start position:0% +convergence there and it has these two +versions the increasing version and the + + align:start position:0% +versions the increasing version and the + + + align:start position:0% +versions the increasing version and the +decreasing version. + + align:start position:0% +decreasing version. + + + align:start position:0% +decreasing version. +Then + + align:start position:0% +Then + + + align:start position:0% +Then +another important concept + + align:start position:0% +another important concept + + + align:start position:0% +another important concept +was that of the precence + + align:start position:0% +was that of the precence + + + align:start position:0% +was that of the precence +and the use the the the + + align:start position:0% +and the use the the the + + + align:start position:0% +and the use the the the +reason why sequence is useful even for + + align:start position:0% +reason why sequence is useful even for + + + align:start position:0% +reason why sequence is useful even for +the real numbers right I mean you know + + align:start position:0% +the real numbers right I mean you know + + + align:start position:0% +the real numbers right I mean you know +later on we generalize these concepts + + align:start position:0% +later on we generalize these concepts + + + align:start position:0% +later on we generalize these concepts +there was obvious generalization of of + + align:start position:0% +there was obvious generalization of of + + + align:start position:0% +there was obvious generalization of of +the concept of convergence but also of + + align:start position:0% +the concept of convergence but also of + + + align:start position:0% +the concept of convergence but also of +that of being a cruise sequence to + + align:start position:0% +that of being a cruise sequence to + + + align:start position:0% +that of being a cruise sequence to +metric spaces + + align:start position:0% +metric spaces + + + align:start position:0% +metric spaces +But even for the real numbers C + + align:start position:0% +But even for the real numbers C + + + align:start position:0% +But even for the real numbers C +sequence, + + align:start position:0% +sequence, + + + align:start position:0% +sequence, +you know, you might be interested in + + align:start position:0% +you know, you might be interested in + + + align:start position:0% +you know, you might be interested in +whether a sequence is convergent. But + + align:start position:0% +whether a sequence is convergent. But + + + align:start position:0% +whether a sequence is convergent. But +sometimes it's much easier to prove that + + align:start position:0% +sometimes it's much easier to prove that + + + align:start position:0% +sometimes it's much easier to prove that +it's a C sequence than to prove that it + + align:start position:0% +it's a C sequence than to prove that it + + + align:start position:0% +it's a C sequence than to prove that it +actually is convergent. And so if you + + align:start position:0% +actually is convergent. And so if you + + + align:start position:0% +actually is convergent. And so if you +don't really care about what the limit + + align:start position:0% +don't really care about what the limit + + + align:start position:0% +don't really care about what the limit +is, then it's often uh easier to prove + + align:start position:0% +is, then it's often uh easier to prove + + + align:start position:0% +is, then it's often uh easier to prove +that it's a co + + align:start position:0% + + + + align:start position:0% + +So cushy sequence. + + align:start position:0% +So cushy sequence. + + + align:start position:0% +So cushy sequence. +So you have a sequence again. We're + + align:start position:0% +So you have a sequence again. We're + + + align:start position:0% +So you have a sequence again. We're +still in in the real numbers. + + align:start position:0% +still in in the real numbers. + + + align:start position:0% +still in in the real numbers. +And this is a cushy sequence. It just + + align:start position:0% +And this is a cushy sequence. It just + + + align:start position:0% +And this is a cushy sequence. It just +means that for all and now I will use + + align:start position:0% +means that for all and now I will use + + + align:start position:0% +means that for all and now I will use +also this here. This symbol just means + + align:start position:0% +also this here. This symbol just means + + + align:start position:0% +also this here. This symbol just means +for all and that's also a standard + + align:start position:0% +for all and that's also a standard + + + align:start position:0% +for all and that's also a standard +symbol. It's a inverted a + + align:start position:0% +symbol. It's a inverted a + + + align:start position:0% +symbol. It's a inverted a +for all epsilon greater than zero there + + align:start position:0% +for all epsilon greater than zero there + + + align:start position:0% +for all epsilon greater than zero there +exist again this here the inver you know + + align:start position:0% +exist again this here the inver you know + + + align:start position:0% +exist again this here the inver you know +inverted e there exist + + align:start position:0% +inverted e there exist + + + align:start position:0% +inverted e there exist +delta there sorry there exist capital n + + align:start position:0% +delta there sorry there exist capital n + + + align:start position:0% +delta there sorry there exist capital n +um such that + + align:start position:0% + + + + align:start position:0% + +if little n and little m are bigger than + + align:start position:0% +if little n and little m are bigger than + + + align:start position:0% +if little n and little m are bigger than +capital n Then those two elements are + + align:start position:0% +capital n Then those two elements are + + + align:start position:0% +capital n Then those two elements are +bunched + + align:start position:0% +bunched + + + align:start position:0% +bunched +epsilon close together. + + align:start position:0% + + + + align:start position:0% + +This is what it means + + align:start position:0% +This is what it means + + + align:start position:0% +This is what it means +for a sequence to be precise sequence + + align:start position:0% +for a sequence to be precise sequence + + + align:start position:0% +for a sequence to be precise sequence +that the tail of the sequence lies very + + align:start position:0% +that the tail of the sequence lies very + + + align:start position:0% +that the tail of the sequence lies very +very close together. + + align:start position:0% + + + + align:start position:0% + +Then um + + align:start position:0% + + + + align:start position:0% + +let me skip uh in my notes I have + + align:start position:0% +let me skip uh in my notes I have + + + align:start position:0% +let me skip uh in my notes I have +something about contracting that but + + align:start position:0% +something about contracting that but + + + align:start position:0% +something about contracting that but +actually there won't be anything about + + align:start position:0% +actually there won't be anything about + + + align:start position:0% +actually there won't be anything about +contracting that so I'll skip that + + align:start position:0% +contracting that so I'll skip that + + + align:start position:0% +contracting that so I'll skip that +uh + + align:start position:0% +uh + + + align:start position:0% +uh +let me uh let me look at let me now next + + align:start position:0% +let me uh let me look at let me now next + + + align:start position:0% +let me uh let me look at let me now next +talk about the + + align:start position:0% +talk about the + + + align:start position:0% +talk about the +convergence + + align:start position:0% + + + + align:start position:0% + +and Put some wires right there. + + align:start position:0% + + + + align:start position:0% + +So you see + + align:start position:0% + + + + align:start position:0% + +also let me just remind you that again + + align:start position:0% +also let me just remind you that again + + + align:start position:0% +also let me just remind you that again +on the midterm so there are these five + + align:start position:0% +on the midterm so there are these five + + + align:start position:0% +on the midterm so there are these five +main problems then there's a six bonus + + align:start position:0% +main problems then there's a six bonus + + + align:start position:0% +main problems then there's a six bonus +problems but make sure that you uh if + + align:start position:0% +problems but make sure that you uh if + + + align:start position:0% +problems but make sure that you uh if +you know it doesn't matter which one you + + align:start position:0% +you know it doesn't matter which one you + + + align:start position:0% +you know it doesn't matter which one you +do so you might as well uh start like + + align:start position:0% +do so you might as well uh start like + + + align:start position:0% +do so you might as well uh start like +with the ones that seems easiest + + align:start position:0% +with the ones that seems easiest + + + align:start position:0% +with the ones that seems easiest +to + + align:start position:0% +to + + + align:start position:0% +to +uh and you can see anyway say exactly + + align:start position:0% +uh and you can see anyway say exactly + + + align:start position:0% +uh and you can see anyway say exactly +how many points each of them give. So + + align:start position:0% +how many points each of them give. So + + + align:start position:0% +how many points each of them give. So +you can uh if you don't have you know + + align:start position:0% +you can uh if you don't have you know + + + align:start position:0% +you can uh if you don't have you know +enough time to finish all of this you + + align:start position:0% +enough time to finish all of this you + + + align:start position:0% +enough time to finish all of this you +can make sure to try to optimize. + + align:start position:0% + + + + align:start position:0% + +Okay. So what is the cushy convergence + + align:start position:0% +Okay. So what is the cushy convergence + + + align:start position:0% +Okay. So what is the cushy convergence +theorem? So again we are in R sorry uh + + align:start position:0% +theorem? So again we are in R sorry uh + + + align:start position:0% +theorem? So again we are in R sorry uh +and uh and we have and so the CI + + align:start position:0% +and uh and we have and so the CI + + + align:start position:0% +and uh and we have and so the CI +convergence is the + + align:start position:0% +convergence is the + + + align:start position:0% +convergence is the +let's say that if XM is a C sequence + + align:start position:0% + + + + align:start position:0% + +then + + align:start position:0% +then + + + align:start position:0% +then +uh XM is converted + + align:start position:0% + + + + align:start position:0% + +That's a pushy convers + + align:start position:0% + + + + align:start position:0% + +and and and this trans we talk about + + align:start position:0% +and and and this trans we talk about + + + align:start position:0% +and and and this trans we talk about +that. So like the concepts if you when + + align:start position:0% +that. So like the concepts if you when + + + align:start position:0% +that. So like the concepts if you when +we in a minute review metric spaces then + + align:start position:0% +we in a minute review metric spaces then + + + align:start position:0% +we in a minute review metric spaces then +convergence sequence that makes sense in + + align:start position:0% +convergence sequence that makes sense in + + + align:start position:0% +convergence sequence that makes sense in +a metric space could see sequence makes + + align:start position:0% +a metric space could see sequence makes + + + align:start position:0% +a metric space could see sequence makes +sense in a metric space + + align:start position:0% +sense in a metric space + + + align:start position:0% +sense in a metric space +um but it's not and the statement of + + align:start position:0% +um but it's not and the statement of + + + align:start position:0% +um but it's not and the statement of +this theorem makes sense in a metric + + align:start position:0% +this theorem makes sense in a metric + + + align:start position:0% +this theorem makes sense in a metric +space but it's not always that it holds + + align:start position:0% +space but it's not always that it holds + + + align:start position:0% +space but it's not always that it holds +it holds in on but it doesn't hold in a + + align:start position:0% +it holds in on but it doesn't hold in a + + + align:start position:0% +it holds in on but it doesn't hold in a +general metric space. The possum + + align:start position:0% + + + + align:start position:0% + +statement of that + + align:start position:0% +statement of that + + + align:start position:0% +statement of that +also makes sense in a general metric + + align:start position:0% +also makes sense in a general metric + + + align:start position:0% +also makes sense in a general metric +space but it doesn't hold in a general + + align:start position:0% +space but it doesn't hold in a general + + + align:start position:0% +space but it doesn't hold in a general +metric space. So these are again these + + align:start position:0% +metric space. So these are again these + + + align:start position:0% +metric space. So these are again these +are things about the real numbers. + + align:start position:0% +are things about the real numbers. + + + align:start position:0% +are things about the real numbers. +I mean they they extend to more than the + + align:start position:0% +I mean they they extend to more than the + + + align:start position:0% +I mean they they extend to more than the +real number but you have to for other + + align:start position:0% +real number but you have to for other + + + align:start position:0% +real number but you have to for other +spaces you have to kind of prove it + + align:start position:0% +spaces you have to kind of prove it + + + align:start position:0% +spaces you have to kind of prove it +individually right. + + align:start position:0% +individually right. + + + align:start position:0% +individually right. +So banana bias theorem say that if xn is + + align:start position:0% +So banana bias theorem say that if xn is + + + align:start position:0% +So banana bias theorem say that if xn is +a bounded sequence + + align:start position:0% + + + + align:start position:0% + +then + + align:start position:0% +then + + + align:start position:0% +then +uh xn has + + align:start position:0% +uh xn has + + + align:start position:0% +uh xn has +a convergent subsequence. + + align:start position:0% + + + + align:start position:0% + +Okay. So that's simp. + + align:start position:0% + + + + align:start position:0% + +Um the next thing is the next thing I + + align:start position:0% +Um the next thing is the next thing I + + + align:start position:0% +Um the next thing is the next thing I +want to review is what it means for a + + align:start position:0% +want to review is what it means for a + + + align:start position:0% +want to review is what it means for a +function to be continuous. So continuity + + align:start position:0% +function to be continuous. So continuity + + + align:start position:0% +function to be continuous. So continuity +is another important property. It's + + align:start position:0% +is another important property. It's + + + align:start position:0% +is another important property. It's +closely tied together with this sequence + + align:start position:0% +closely tied together with this sequence + + + align:start position:0% +closely tied together with this sequence +and we'll get to that in just a minute. + + align:start position:0% +and we'll get to that in just a minute. + + + align:start position:0% +and we'll get to that in just a minute. +So if you take a + + align:start position:0% +So if you take a + + + align:start position:0% +So if you take a +if you take and you have + + align:start position:0% + + + + align:start position:0% + +so so + + align:start position:0% +so so + + + align:start position:0% +so so +if you have a function let's say on R + + align:start position:0% +if you have a function let's say on R + + + align:start position:0% +if you have a function let's say on R +but it could be defined on a subset of + + align:start position:0% +but it could be defined on a subset of + + + align:start position:0% +but it could be defined on a subset of +R. So if you have a function like this + + align:start position:0% +R. So if you have a function like this + + + align:start position:0% +R. So if you have a function like this +then we say that f here + + align:start position:0% +then we say that f here + + + align:start position:0% +then we say that f here +is continuous + + align:start position:0% + + + + align:start position:0% + +at x0 + + align:start position:0% +at x0 + + + align:start position:0% +at x0 +if for all + + align:start position:0% + + + + align:start position:0% + +uh it's continuous at x0 + + align:start position:0% +uh it's continuous at x0 + + + align:start position:0% +uh it's continuous at x0 +if for all u epsilon greater zero there + + align:start position:0% +if for all u epsilon greater zero there + + + align:start position:0% +if for all u epsilon greater zero there +exist + + align:start position:0% + + + + align:start position:0% + +delta greater than zero such that + + align:start position:0% +delta greater than zero such that + + + align:start position:0% +delta greater than zero such that +if uh x - x0 + + align:start position:0% +if uh x - x0 + + + align:start position:0% +if uh x - x0 +is smaller than delta then the images + + align:start position:0% + + + + align:start position:0% + +smaller than epsilon + + align:start position:0% + + + + align:start position:0% + +um so that what it means for a function + + align:start position:0% +um so that what it means for a function + + + align:start position:0% +um so that what it means for a function +to be continuous and there was this + + align:start position:0% +to be continuous and there was this + + + align:start position:0% +to be continuous and there was this +this theorem or lema + + align:start position:0% +this theorem or lema + + + align:start position:0% +this theorem or lema +that was that tied things together. So + + align:start position:0% +that was that tied things together. So + + + align:start position:0% +that was that tied things together. So +lema + + align:start position:0% + + + + align:start position:0% + +if + + align:start position:0% + + + + align:start position:0% + +uh f is continuous + + align:start position:0% + + + + align:start position:0% + +at x0 + + align:start position:0% +at x0 + + + align:start position:0% +at x0 +and xn + + align:start position:0% +and xn + + + align:start position:0% +and xn +converge to x0 + + align:start position:0% +converge to x0 + + + align:start position:0% +converge to x0 +then + + align:start position:0% +then + + + align:start position:0% +then +then then + + align:start position:0% +then then + + + align:start position:0% +then then +the images + + align:start position:0% +the images + + + align:start position:0% +the images +of this sequence. So that's another + + align:start position:0% +of this sequence. So that's another + + + align:start position:0% +of this sequence. So that's another +sequence convert. + + align:start position:0% + + + + align:start position:0% + +So we prove this even in a metric space + + align:start position:0% +So we prove this even in a metric space + + + align:start position:0% +So we prove this even in a metric space +but we're still not. + + align:start position:0% +but we're still not. + + + align:start position:0% +but we're still not. +Okay. And so + + align:start position:0% +Okay. And so + + + align:start position:0% +Okay. And so +uh right and then we had the algebraic + + align:start position:0% +uh right and then we had the algebraic + + + align:start position:0% +uh right and then we had the algebraic +properties of functions and they were + + align:start position:0% +properties of functions and they were + + + align:start position:0% +properties of functions and they were +very similar to this. So let me just + + align:start position:0% +very similar to this. So let me just + + + align:start position:0% +very similar to this. So let me just +review them. So algebraic properties of + + align:start position:0% +review them. So algebraic properties of + + + align:start position:0% +review them. So algebraic properties of +continuous functions. + + align:start position:0% + + + + align:start position:0% + +So imagine that you have f and g + + align:start position:0% +So imagine that you have f and g + + + align:start position:0% +So imagine that you have f and g +are continuous functions. + + align:start position:0% + + + + align:start position:0% + +Everything is defined on r. + + align:start position:0% +Everything is defined on r. + + + align:start position:0% +Everything is defined on r. +C here is a constant. + + align:start position:0% +C here is a constant. + + + align:start position:0% +C here is a constant. +Well then property one that correspond + + align:start position:0% +Well then property one that correspond + + + align:start position:0% +Well then property one that correspond +to that property one here is that this + + align:start position:0% +to that property one here is that this + + + align:start position:0% +to that property one here is that this +function plus C * this function here + + align:start position:0% +function plus C * this function here + + + align:start position:0% +function plus C * this function here +this here is also continuous + + align:start position:0% + + + + align:start position:0% + +and then two is that if this function + + align:start position:0% +and then two is that if this function + + + align:start position:0% +and then two is that if this function +here + + align:start position:0% +here + + + align:start position:0% +here +is never equal to zero + + align:start position:0% +is never equal to zero + + + align:start position:0% +is never equal to zero +then one over this function again is is + + align:start position:0% +then one over this function again is is + + + align:start position:0% +then one over this function again is is +also continuous + + align:start position:0% + + + + align:start position:0% + +and then sorry that was not that should + + align:start position:0% +and then sorry that was not that should + + + align:start position:0% +and then sorry that was not that should +sorry I should not make that the second + + align:start position:0% +sorry I should not make that the second + + + align:start position:0% +sorry I should not make that the second +I should make that the third property + + align:start position:0% +I should make that the third property + + + align:start position:0% +I should make that the third property +sorry that f * + + align:start position:0% +sorry that f * + + + align:start position:0% +sorry that f * +is also continuous and then the third + + align:start position:0% +is also continuous and then the third + + + align:start position:0% +is also continuous and then the third +property would be that f is not equal to + + align:start position:0% +property would be that f is not equal to + + + align:start position:0% +property would be that f is not equal to +z correspond to it then this function + + align:start position:0% +z correspond to it then this function + + + align:start position:0% +z correspond to it then this function +here is also contin + + align:start position:0% + + + + align:start position:0% + +and Again I divided it up when I did it + + align:start position:0% +and Again I divided it up when I did it + + + align:start position:0% +and Again I divided it up when I did it +I divided up into four steps because I + + align:start position:0% +I divided up into four steps because I + + + align:start position:0% +I divided up into four steps because I +separated this out as two steps. + + align:start position:0% +separated this out as two steps. + + + align:start position:0% +separated this out as two steps. +Okay. And so from this one we got that + + align:start position:0% +Okay. And so from this one we got that + + + align:start position:0% +Okay. And so from this one we got that +right just because then we proved that + + align:start position:0% +right just because then we proved that + + + align:start position:0% +right just because then we proved that +the constant function was continuous and + + align:start position:0% +the constant function was continuous and + + + align:start position:0% +the constant function was continuous and +the linear function the function f ofx= + + align:start position:0% +the linear function the function f ofx= + + + align:start position:0% +the linear function the function f ofx= +to x is continuous. Once we have that + + align:start position:0% +to x is continuous. Once we have that + + + align:start position:0% +to x is continuous. Once we have that +then we then we just use one and two. + + align:start position:0% +then we then we just use one and two. + + + align:start position:0% +then we then we just use one and two. +>> Yeah. + + align:start position:0% +>> Yeah. + + + align:start position:0% +>> Yeah. +>> To prove that all all uh polomials is + + align:start position:0% +>> To prove that all all uh polomials is + + + align:start position:0% +>> To prove that all all uh polomials is +continuous. And then if we bring in + + align:start position:0% +continuous. And then if we bring in + + + align:start position:0% +continuous. And then if we bring in +three then we have this with all + + align:start position:0% +three then we have this with all + + + align:start position:0% +three then we have this with all +rational functions are continuous except + + align:start position:0% +rational functions are continuous except + + + align:start position:0% +rational functions are continuous except +of course where the denominator vanishes + + align:start position:0% +of course where the denominator vanishes + + + align:start position:0% +of course where the denominator vanishes +by. + + align:start position:0% +by. + + + align:start position:0% +by. +Okay. So, so that was how you sort of + + align:start position:0% +Okay. So, so that was how you sort of + + + align:start position:0% +Okay. So, so that was how you sort of +built uh continuous functions from non + + align:start position:0% +built uh continuous functions from non + + + align:start position:0% +built uh continuous functions from non +continuous functions. + + align:start position:0% +continuous functions. + + + align:start position:0% +continuous functions. +Um then we proved the extreme value and + + align:start position:0% +Um then we proved the extreme value and + + + align:start position:0% +Um then we proved the extreme value and +the intermediate values theorem. We had + + align:start position:0% +the intermediate values theorem. We had + + + align:start position:0% +the intermediate values theorem. We had +these two zero and they were proved. So + + align:start position:0% +these two zero and they were proved. So + + + align:start position:0% +these two zero and they were proved. So +one way to prove it that we did last + + align:start position:0% +one way to prove it that we did last + + + align:start position:0% +one way to prove it that we did last +time was to use this lemon that tie + + align:start position:0% +time was to use this lemon that tie + + + align:start position:0% +time was to use this lemon that tie +together + + align:start position:0% +together + + + align:start position:0% +together +um that tie together continuity and + + align:start position:0% +um that tie together continuity and + + + align:start position:0% +um that tie together continuity and +sequences. + + align:start position:0% +sequences. + + + align:start position:0% +sequences. +And so we had the extreme values there + + align:start position:0% +And so we had the extreme values there + + + align:start position:0% +And so we had the extreme values there +and this just say that if you have a + + align:start position:0% +and this just say that if you have a + + + align:start position:0% +and this just say that if you have a +function but now it's crucial + + align:start position:0% +function but now it's crucial + + + align:start position:0% +function but now it's crucial +that this here is a bounded interval and + + align:start position:0% +that this here is a bounded interval and + + + align:start position:0% +that this here is a bounded interval and +the end points are included in this. So + + align:start position:0% +the end points are included in this. So + + + align:start position:0% +the end points are included in this. So +if you have a function like this and + + align:start position:0% +if you have a function like this and + + + align:start position:0% +if you have a function like this and +this function is continuous + + align:start position:0% + + + + align:start position:0% + +then the soup and the in over the set + + align:start position:0% +then the soup and the in over the set + + + align:start position:0% +then the soup and the in over the set +here is achieved. So max or if you go + + align:start position:0% +here is achieved. So max or if you go + + + align:start position:0% +here is achieved. So max or if you go +the max of f and min of + + align:start position:0% +the max of f and min of + + + align:start position:0% +the max of f and min of +of f are achieved. + + align:start position:0% + + + + align:start position:0% + +in particular the function is bounded. + + align:start position:0% +in particular the function is bounded. + + + align:start position:0% +in particular the function is bounded. +So I just state it like this little + + align:start position:0% +So I just state it like this little + + + align:start position:0% +So I just state it like this little +brief like that. So that was the extreme + + align:start position:0% +brief like that. So that was the extreme + + + align:start position:0% +brief like that. So that was the extreme +value theorem. The intermediate value + + align:start position:0% +value theorem. The intermediate value + + + align:start position:0% +value theorem. The intermediate value +theorem + + align:start position:0% +theorem + + + align:start position:0% +theorem +it say that if you have a function + + align:start position:0% +it say that if you have a function + + + align:start position:0% +it say that if you have a function +imagine that starting off here and it + + align:start position:0% +imagine that starting off here and it + + + align:start position:0% +imagine that starting off here and it +ending there. So this is like the + + align:start position:0% +ending there. So this is like the + + + align:start position:0% +ending there. So this is like the +function the intermediate value shall + + align:start position:0% +function the intermediate value shall + + + align:start position:0% +function the intermediate value shall +say that everything in between these two + + align:start position:0% +say that everything in between these two + + + align:start position:0% +say that everything in between these two +is also the image of something right. So + + align:start position:0% +is also the image of something right. So + + + align:start position:0% +is also the image of something right. So +if let's say that f of a smaller than f + + align:start position:0% +if let's say that f of a smaller than f + + + align:start position:0% +if let's say that f of a smaller than f +of b + + align:start position:0% +of b + + + align:start position:0% +of b +then n y here is between f of a and f of + + align:start position:0% +then n y here is between f of a and f of + + + align:start position:0% +then n y here is between f of a and f of +b + + align:start position:0% +b + + + align:start position:0% +b +then there exist + + align:start position:0% +then there exist + + + align:start position:0% +then there exist +x between a and b + + align:start position:0% +x between a and b + + + align:start position:0% +x between a and b +so that f of x + + align:start position:0% +so that f of x + + + align:start position:0% +so that f of x +is equal to one. Again the functions + + align:start position:0% +is equal to one. Again the functions + + + align:start position:0% +is equal to one. Again the functions +we're talking about are continuous right + + align:start position:0% +we're talking about are continuous right + + + align:start position:0% +we're talking about are continuous right +and they're defined on this inter + + align:start position:0% +and they're defined on this inter + + + align:start position:0% +and they're defined on this inter +this inter + + align:start position:0% +this inter + + + align:start position:0% +this inter +okay so that was those two themselium + + align:start position:0% + + + + align:start position:0% + +right and then they used uh And then he + + align:start position:0% +right and then they used uh And then he + + + align:start position:0% +right and then they used uh And then he +used how sequences and continuous + + align:start position:0% +used how sequences and continuous + + + align:start position:0% +used how sequences and continuous +functions was tied together. The Banana + + align:start position:0% +functions was tied together. The Banana + + + align:start position:0% +functions was tied together. The Banana +bias theorem is using something about + + align:start position:0% +bias theorem is using something about + + + align:start position:0% +bias theorem is using something about +the real numbers are ordered and like + + align:start position:0% +the real numbers are ordered and like + + + align:start position:0% +the real numbers are ordered and like +this will soup and if uh uh you know you + + align:start position:0% +this will soup and if uh uh you know you + + + align:start position:0% +this will soup and if uh uh you know you +have the least upper bound property and + + align:start position:0% +have the least upper bound property and + + + align:start position:0% +have the least upper bound property and +the greatest lower bound property, + + align:start position:0% +the greatest lower bound property, + + + align:start position:0% +the greatest lower bound property, +right? So + + align:start position:0% +right? So + + + align:start position:0% +right? So +okay now another thing. So there was so + + align:start position:0% +okay now another thing. So there was so + + + align:start position:0% +okay now another thing. So there was so +we tal about so like some of the + + align:start position:0% +we tal about so like some of the + + + align:start position:0% +we tal about so like some of the +highlights is like the in terms of + + align:start position:0% +highlights is like the in terms of + + + align:start position:0% +highlights is like the in terms of +concepts are sequences and continuity of + + align:start position:0% +concepts are sequences and continuity of + + + align:start position:0% +concepts are sequences and continuity of +functions + + align:start position:0% +functions + + + align:start position:0% +functions +and then various properties that follow + + align:start position:0% +and then various properties that follow + + + align:start position:0% +and then various properties that follow +from this. Then another thing is + + align:start position:0% +from this. Then another thing is + + + align:start position:0% +from this. Then another thing is +sequence series. + + align:start position:0% +sequence series. + + + align:start position:0% +sequence series. +So that's another key property + + align:start position:0% +So that's another key property + + + align:start position:0% +So that's another key property +key concept. + + align:start position:0% + + + + align:start position:0% + +So series. + + align:start position:0% + + + + align:start position:0% + +So series is where you started with a + + align:start position:0% +So series is where you started with a + + + align:start position:0% +So series is where you started with a +sequence. + + align:start position:0% + + + + align:start position:0% + +So + + align:start position:0% +So + + + align:start position:0% +So +serious. + + align:start position:0% +serious. + + + align:start position:0% +serious. +So you started with so this here is a + + align:start position:0% +So you started with so this here is a + + + align:start position:0% +So you started with so this here is a +sequence + + align:start position:0% + + + + align:start position:0% + +and now you form another + + align:start position:0% +and now you form another + + + align:start position:0% +and now you form another +sequence sn but here you sum it and it + + align:start position:0% +sequence sn but here you sum it and it + + + align:start position:0% +sequence sn but here you sum it and it +could start wherever you want to start + + align:start position:0% +could start wherever you want to start + + + align:start position:0% +could start wherever you want to start +it let's say start from zero you're + + align:start position:0% +it let's say start from zero you're + + + align:start position:0% +it let's say start from zero you're +summing the first in this case it would + + align:start position:0% +summing the first in this case it would + + + align:start position:0% +summing the first in this case it would +be because you're starting at zero + + align:start position:0% +be because you're starting at zero + + + align:start position:0% +be because you're starting at zero +you're summing the first n + one + + align:start position:0% +you're summing the first n + one + + + align:start position:0% +you're summing the first n + one +so ai this is A z + + + align:start position:0% +so ai this is A z + + + + align:start position:0% +so ai this is A z + +a n is like n + one in this case, but + + align:start position:0% +a n is like n + one in this case, but + + + align:start position:0% +a n is like n + one in this case, but +you don't have to start at zero. You + + align:start position:0% +you don't have to start at zero. You + + + align:start position:0% +you don't have to start at zero. You +start at one, it would be the first n + + align:start position:0% +start at one, it would be the first n + + + align:start position:0% +start at one, it would be the first n +numbers. + + align:start position:0% +numbers. + + + align:start position:0% +numbers. +So you're looking at so a series is + + align:start position:0% +So you're looking at so a series is + + + align:start position:0% +So you're looking at so a series is +really kind of the same thing, but you + + align:start position:0% +really kind of the same thing, but you + + + align:start position:0% +really kind of the same thing, but you +think about it a little bit different, + + align:start position:0% +think about it a little bit different, + + + align:start position:0% +think about it a little bit different, +but really the same thing as a sequence + + align:start position:0% +but really the same thing as a sequence + + + align:start position:0% +but really the same thing as a sequence +where you starting with a sequence and + + align:start position:0% +where you starting with a sequence and + + + align:start position:0% +where you starting with a sequence and +then you form a new sequence. + + align:start position:0% +then you form a new sequence. + + + align:start position:0% +then you form a new sequence. +And then the the key question here is so + + align:start position:0% +And then the the key question here is so + + + align:start position:0% +And then the the key question here is so +key question + + align:start position:0% + + + + align:start position:0% + +is the serious conversion + + align:start position:0% + + + + align:start position:0% + +conversion, + + align:start position:0% + + + + align:start position:0% + +right? And um so that's a key question + + align:start position:0% +right? And um so that's a key question + + + align:start position:0% +right? And um so that's a key question +and if it is convergent and you often + + align:start position:0% +and if it is convergent and you often + + + align:start position:0% +and if it is convergent and you often +the series is often written like this + + align:start position:0% +the series is often written like this + + + align:start position:0% +the series is often written like this +and so this is so this here will + + align:start position:0% +and so this is so this here will + + + align:start position:0% +and so this is so this here will +symbolize the series and if the series + + align:start position:0% +symbolize the series and if the series + + + align:start position:0% +symbolize the series and if the series +is convergent it will also symbolize the + + align:start position:0% +is convergent it will also symbolize the + + + align:start position:0% +is convergent it will also symbolize the +limit. So it has two meanings. Okay. + + align:start position:0% +limit. So it has two meanings. Okay. + + + align:start position:0% +limit. So it has two meanings. Okay. +Um but you can but even if it's not + + align:start position:0% +Um but you can but even if it's not + + + align:start position:0% +Um but you can but even if it's not +convergent then it well but if it's not + + align:start position:0% +convergent then it well but if it's not + + + align:start position:0% +convergent then it well but if it's not +convergent you would just write down and + + align:start position:0% +convergent you would just write down and + + + align:start position:0% +convergent you would just write down and +you think about this as as as a series. + + align:start position:0% +you think about this as as as a series. + + + align:start position:0% +you think about this as as as a series. +Now there are some series that are + + align:start position:0% +Now there are some series that are + + + align:start position:0% +Now there are some series that are +particular + + align:start position:0% +particular + + + align:start position:0% +particular +you know important + + align:start position:0% + + + + align:start position:0% + +and and they can then be used to + + align:start position:0% +and and they can then be used to + + + align:start position:0% +and and they can then be used to +determine whether or not other series. + + align:start position:0% + + + + align:start position:0% + +So let me just review them. And the most + + align:start position:0% +So let me just review them. And the most + + + align:start position:0% +So let me just review them. And the most +important of all is the geometric + + align:start position:0% +important of all is the geometric + + + align:start position:0% +important of all is the geometric +series. + + align:start position:0% + + + + align:start position:0% + +And the geometric series is the series + + align:start position:0% +And the geometric series is the series + + + align:start position:0% +And the geometric series is the series +um + + align:start position:0% +um + + + align:start position:0% +um +C to the N= + + align:start position:0% +C to the N= + + + align:start position:0% +C to the N= +to Z to infinity. + + align:start position:0% +to Z to infinity. + + + align:start position:0% +to Z to infinity. +This is C is just some fixed number, + + align:start position:0% +This is C is just some fixed number, + + + align:start position:0% +This is C is just some fixed number, +real number. And you're looking at this + + align:start position:0% +real number. And you're looking at this + + + align:start position:0% +real number. And you're looking at this +and this is called this is the geometric + + align:start position:0% +and this is called this is the geometric + + + align:start position:0% +and this is called this is the geometric +series + + align:start position:0% +series + + + align:start position:0% +series +and this is is convergent. + + align:start position:0% + + + + align:start position:0% + +uh if + + align:start position:0% +uh if + + + align:start position:0% +uh if +the absolute value of C is less than one + + align:start position:0% +the absolute value of C is less than one + + + align:start position:0% +the absolute value of C is less than one +and divergent otherwise + + align:start position:0% + + + + align:start position:0% + +and if it is convergent when + + align:start position:0% +and if it is convergent when + + + align:start position:0% +and if it is convergent when +when C here in absolute value is less + + align:start position:0% +when C here in absolute value is less + + + align:start position:0% +when C here in absolute value is less +than one then this here + + align:start position:0% + + + + align:start position:0% + +is = 1us + + align:start position:0% + + + + align:start position:0% + +but remember two things one is that when + + align:start position:0% +but remember two things one is that when + + + align:start position:0% +but remember two things one is that when +you actually want to evaluate the sum + + align:start position:0% +you actually want to evaluate the sum + + + align:start position:0% +you actually want to evaluate the sum +it's crucial where you starting if I + + align:start position:0% +it's crucial where you starting if I + + + align:start position:0% +it's crucial where you starting if I +started at one then it's not anymore + + align:start position:0% +started at one then it's not anymore + + + align:start position:0% +started at one then it's not anymore +equal to this but you have to subtract + + align:start position:0% +equal to this but you have to subtract + + + align:start position:0% +equal to this but you have to subtract +the first element right that was missing + + align:start position:0% +the first element right that was missing + + + align:start position:0% +the first element right that was missing +so it's really for convergence it + + align:start position:0% +so it's really for convergence it + + + align:start position:0% +so it's really for convergence it +doesn't matter where you start but for + + align:start position:0% +doesn't matter where you start but for + + + align:start position:0% +doesn't matter where you start but for +the limits it's it's it's + + align:start position:0% + + + + align:start position:0% + +That's one thing and the other thing is + + align:start position:0% +That's one thing and the other thing is + + + align:start position:0% +That's one thing and the other thing is +uh is like when you again we talk about + + align:start position:0% +uh is like when you again we talk about + + + align:start position:0% +uh is like when you again we talk about +this that when you're given a series + + align:start position:0% +this that when you're given a series + + + align:start position:0% +this that when you're given a series +even before there's any question the + + align:start position:0% +even before there's any question the + + + align:start position:0% +even before there's any question the +first thing when you have a series the + + align:start position:0% +first thing when you have a series the + + + align:start position:0% +first thing when you have a series the +first thing you look at is does this a + + align:start position:0% +first thing you look at is does this a + + + align:start position:0% +first thing you look at is does this a +end convert to zero or not right if a + + align:start position:0% +end convert to zero or not right if a + + + align:start position:0% +end convert to zero or not right if a +end does not go to zero well the series + + align:start position:0% +end does not go to zero well the series + + + align:start position:0% +end does not go to zero well the series +is not going to converge there's no need + + align:start position:0% +is not going to converge there's no need + + + align:start position:0% +is not going to converge there's no need +to apply any fancy test right and and + + align:start position:0% +to apply any fancy test right and and + + + align:start position:0% +to apply any fancy test right and and +for a series it's it's always the + + align:start position:0% +for a series it's it's always the + + + align:start position:0% +for a series it's it's always the +question is always whether it's + + align:start position:0% +question is always whether it's + + + align:start position:0% +question is always whether it's +convergent or not. + + align:start position:0% + + + + align:start position:0% + +Okay. So that's so that's a geometric + + align:start position:0% +Okay. So that's so that's a geometric + + + align:start position:0% +Okay. So that's so that's a geometric +series + + align:start position:0% +series + + + align:start position:0% +series +and then there are two other series that + + align:start position:0% +and then there are two other series that + + + align:start position:0% +and then there are two other series that +we talked about and let me just you know + + align:start position:0% +we talked about and let me just you know + + + align:start position:0% +we talked about and let me just you know +that not only talked about but we also + + align:start position:0% +that not only talked about but we also + + + align:start position:0% +that not only talked about but we also +determined whether or not they were + + align:start position:0% +determined whether or not they were + + + align:start position:0% +determined whether or not they were +converging and they were used then we + + align:start position:0% +converging and they were used then we + + + align:start position:0% +converging and they were used then we +used them to determine whether other + + align:start position:0% +used them to determine whether other + + + align:start position:0% +used them to determine whether other +series were convergent. + + align:start position:0% + + + + align:start position:0% + +But but the again the most important of + + align:start position:0% +But but the again the most important of + + + align:start position:0% +But but the again the most important of +all of them is the geometric series. + + align:start position:0% +all of them is the geometric series. + + + align:start position:0% +all of them is the geometric series. +That's the one that we use to determine + + align:start position:0% +That's the one that we use to determine + + + align:start position:0% +That's the one that we use to determine +whether power series in general was + + align:start position:0% +whether power series in general was + + + align:start position:0% +whether power series in general was +converging or not. But there are two + + align:start position:0% +converging or not. But there are two + + + align:start position:0% +converging or not. But there are two +other that are worth mentioning. One is + + align:start position:0% +other that are worth mentioning. One is + + + align:start position:0% +other that are worth mentioning. One is +the harmonic series. + + align:start position:0% + + + + align:start position:0% + +The harmonic series is the series + + align:start position:0% +The harmonic series is the series + + + align:start position:0% +The harmonic series is the series +1 / n. + + align:start position:0% +1 / n. + + + align:start position:0% +1 / n. +So this here is diverg. + + align:start position:0% + + + + align:start position:0% + +So let's call this second + + align:start position:0% +So let's call this second + + + align:start position:0% +So let's call this second +and then there is like a + + align:start position:0% +and then there is like a + + + align:start position:0% +and then there is like a +closely related. Let's call it two and a + + align:start position:0% +closely related. Let's call it two and a + + + align:start position:0% +closely related. Let's call it two and a +half. + + align:start position:0% +half. + + + align:start position:0% +half. +That's called the alternating. + + align:start position:0% + + + + align:start position:0% + +So the alternating was that the it was + + align:start position:0% +So the alternating was that the it was + + + align:start position:0% +So the alternating was that the it was +like the harmonic series but the sign of + + align:start position:0% +like the harmonic series but the sign of + + + align:start position:0% +like the harmonic series but the sign of +it was alternating + + align:start position:0% + + + + align:start position:0% + +and this here is actually converging + + align:start position:0% + + + + align:start position:0% + +and then so there's one two two and a + + align:start position:0% +and then so there's one two two and a + + + align:start position:0% +and then so there's one two two and a +half and then there's three + + align:start position:0% +half and then there's three + + + align:start position:0% +half and then there's three +uh three and that's uh that's the series + + align:start position:0% +uh three and that's uh that's the series + + + align:start position:0% +uh three and that's uh that's the series +this series. Here we this year and this + + align:start position:0% +this series. Here we this year and this + + + align:start position:0% +this series. Here we this year and this +year was converging. + + align:start position:0% + + + + align:start position:0% + +The only one where we determine what the + + align:start position:0% +The only one where we determine what the + + + align:start position:0% +The only one where we determine what the +sum was was actually the geometric + + align:start position:0% +sum was was actually the geometric + + + align:start position:0% +sum was was actually the geometric +series. + + align:start position:0% + + + + align:start position:0% + +Okay. So that's like some key series. + + align:start position:0% +Okay. So that's like some key series. + + + align:start position:0% +Okay. So that's like some key series. +Um + + align:start position:0% +Um + + + align:start position:0% +Um +then + + align:start position:0% + + + + align:start position:0% + +then there are + + align:start position:0% +then there are + + + align:start position:0% +then there are +then there's when you have a series + + align:start position:0% +then there's when you have a series + + + align:start position:0% +then there's when you have a series +there was one concept that proved to be + + align:start position:0% +there was one concept that proved to be + + + align:start position:0% +there was one concept that proved to be +quite useful and that's was the concept + + align:start position:0% +quite useful and that's was the concept + + + align:start position:0% +quite useful and that's was the concept +of absolute + + align:start position:0% +of absolute + + + align:start position:0% +of absolute +convergence. + + align:start position:0% + + + + align:start position:0% + +of a series + + align:start position:0% + + + + align:start position:0% + +and so you're looking at a series + + align:start position:0% +and so you're looking at a series + + + align:start position:0% +and so you're looking at a series +and absolute convergence was + + align:start position:0% +and absolute convergence was + + + align:start position:0% +and absolute convergence was +that this sum here + + align:start position:0% +that this sum here + + + align:start position:0% +that this sum here +was was converging. So this here is + + align:start position:0% +was was converging. So this here is + + + align:start position:0% +was was converging. So this here is +absolute + + align:start position:0% + + + + align:start position:0% + +convergent. + + align:start position:0% + + + + align:start position:0% + +If this series where you just the a + + align:start position:0% +If this series where you just the a + + + align:start position:0% +If this series where you just the a +replaced by the absolute value is + + align:start position:0% +replaced by the absolute value is + + + align:start position:0% +replaced by the absolute value is +convergent. Okay. So of course a non- + + align:start position:0% +convergent. Okay. So of course a non- + + + align:start position:0% +convergent. Okay. So of course a non- +negative for non for a series of non- + + align:start position:0% +negative for non for a series of non- + + + align:start position:0% +negative for non for a series of non- +negative numbers it's automatically if + + align:start position:0% +negative numbers it's automatically if + + + align:start position:0% +negative numbers it's automatically if +it's convergence it's automatically + + align:start position:0% +it's convergence it's automatically + + + align:start position:0% +it's convergence it's automatically +absolute convergent. + + align:start position:0% +absolute convergent. + + + align:start position:0% +absolute convergent. +And like we talked about it a little bit + + align:start position:0% +And like we talked about it a little bit + + + align:start position:0% +And like we talked about it a little bit +that that one of the things about an + + align:start position:0% +that that one of the things about an + + + align:start position:0% +that that one of the things about an +absolute convergent is that you could + + align:start position:0% +absolute convergent is that you could + + + align:start position:0% +absolute convergent is that you could +kind of reorder the value of summing + + align:start position:0% +kind of reorder the value of summing + + + align:start position:0% +kind of reorder the value of summing +things and it wouldn't matter for the + + align:start position:0% +things and it wouldn't matter for the + + + align:start position:0% +things and it wouldn't matter for the +limit. + + align:start position:0% +limit. + + + align:start position:0% +limit. +But if it's not absolute convergent that + + align:start position:0% +But if it's not absolute convergent that + + + align:start position:0% +But if it's not absolute convergent that +really matters we thought about it. We + + align:start position:0% +really matters we thought about it. We + + + align:start position:0% +really matters we thought about it. We +didn't really prove anything there but I + + align:start position:0% +didn't really prove anything there but I + + + align:start position:0% +didn't really prove anything there but I +think it was kind of clear you can do + + align:start position:0% +think it was kind of clear you can do + + + align:start position:0% +think it was kind of clear you can do +this. + + align:start position:0% +this. + + + align:start position:0% +this. +One thing where we used it was that when + + align:start position:0% +One thing where we used it was that when + + + align:start position:0% +One thing where we used it was that when +we look at product of series + + align:start position:0% +we look at product of series + + + align:start position:0% +we look at product of series +then the product of series was + + align:start position:0% +then the product of series was + + + align:start position:0% +then the product of series was +convergent if each of them was absolute + + align:start position:0% +convergent if each of them was absolute + + + align:start position:0% +convergent if each of them was absolute +convergence and there you saw that we + + align:start position:0% +convergence and there you saw that we + + + align:start position:0% +convergence and there you saw that we +estimated some remainder term and there + + align:start position:0% +estimated some remainder term and there + + + align:start position:0% +estimated some remainder term and there +was really kind of key that that we had + + align:start position:0% +was really kind of key that that we had + + + align:start position:0% +was really kind of key that that we had +absolute convergence. Okay. + + align:start position:0% +absolute convergence. Okay. + + + align:start position:0% +absolute convergence. Okay. +So anyway, so absolute convergence is an + + align:start position:0% +So anyway, so absolute convergence is an + + + align:start position:0% +So anyway, so absolute convergence is an +important uh you know it's it's it's for + + align:start position:0% +important uh you know it's it's it's for + + + align:start position:0% +important uh you know it's it's it's for +a series it's a it's a stronger property + + align:start position:0% +a series it's a it's a stronger property + + + align:start position:0% +a series it's a it's a stronger property +than convergence. So absolute + + align:start position:0% +than convergence. So absolute + + + align:start position:0% +than convergence. So absolute +convergence implies convergence. Maybe I + + align:start position:0% +convergence implies convergence. Maybe I + + + align:start position:0% +convergence implies convergence. Maybe I +should write this as a theorem. So we + + align:start position:0% +should write this as a theorem. So we + + + align:start position:0% +should write this as a theorem. So we +had that theorem. So absolute conversion + + align:start position:0% + + + + align:start position:0% + +but it's not it's it's stronger. + + align:start position:0% +but it's not it's it's stronger. + + + align:start position:0% +but it's not it's it's stronger. +general. + + align:start position:0% + + + + align:start position:0% + +Okay. And now then we had some tests. + + align:start position:0% +Okay. And now then we had some tests. + + + align:start position:0% +Okay. And now then we had some tests. +Then we had some tests and so we had uh + + align:start position:0% +Then we had some tests and so we had uh + + + align:start position:0% +Then we had some tests and so we had uh +we talked in particular about + + align:start position:0% +we talked in particular about + + + align:start position:0% +we talked in particular about +there was a few other tests that we + + align:start position:0% +there was a few other tests that we + + + align:start position:0% +there was a few other tests that we +talked about but but I didn't + + align:start position:0% +talked about but but I didn't + + + align:start position:0% +talked about but but I didn't +um I mean they're not actually going to + + align:start position:0% +um I mean they're not actually going to + + + align:start position:0% +um I mean they're not actually going to +be on the victim uh and and some of them + + align:start position:0% +be on the victim uh and and some of them + + + align:start position:0% +be on the victim uh and and some of them +we get back to this one here won't be on + + align:start position:0% +we get back to this one here won't be on + + + align:start position:0% +we get back to this one here won't be on +the victim alternating but we talked + + align:start position:0% +the victim alternating but we talked + + + align:start position:0% +the victim alternating but we talked +about how to prove the convergence right + + align:start position:0% +about how to prove the convergence right + + + align:start position:0% +about how to prove the convergence right +and the important and and when we talk + + align:start position:0% +and the important and and when we talk + + + align:start position:0% +and the important and and when we talk +about + + align:start position:0% +about + + + align:start position:0% +about +that we discovered that this thing here + + align:start position:0% +that we discovered that this thing here + + + align:start position:0% +that we discovered that this thing here +that there was a stronger statement that + + align:start position:0% +that there was a stronger statement that + + + align:start position:0% +that there was a stronger statement that +if you have alternating and the a were + + align:start position:0% +if you have alternating and the a were + + + align:start position:0% +if you have alternating and the a were +all non negative and these guys was + + align:start position:0% +all non negative and these guys was + + + align:start position:0% +all non negative and these guys was +decreasing goes decreasing down to zero + + align:start position:0% +decreasing goes decreasing down to zero + + + align:start position:0% +decreasing goes decreasing down to zero +then actually any alternating sequence + + align:start position:0% +then actually any alternating sequence + + + align:start position:0% +then actually any alternating sequence +like that would be would be converging + + align:start position:0% +like that would be would be converging + + + align:start position:0% +like that would be would be converging +anyway but but but the test we really + + align:start position:0% +anyway but but but the test we really + + + align:start position:0% +anyway but but but the test we really +talked about was three test. One of them + + align:start position:0% +talked about was three test. One of them + + + align:start position:0% +talked about was three test. One of them +had two parts + + align:start position:0% + + + + align:start position:0% + +and then then in a minute we'll talk + + align:start position:0% +and then then in a minute we'll talk + + + align:start position:0% +and then then in a minute we'll talk +about how we apply them to power series + + align:start position:0% +about how we apply them to power series + + + align:start position:0% +about how we apply them to power series +which one. So we had some tests + + align:start position:0% +which one. So we had some tests + + + align:start position:0% +which one. So we had some tests +to determine + + align:start position:0% + + + + align:start position:0% + +whether or not the series + + align:start position:0% + + + + align:start position:0% + +or not as serious + + align:start position:0% +or not as serious + + + align:start position:0% +or not as serious +uh + + align:start position:0% + + + + align:start position:0% + +is convergence. + + align:start position:0% + + + + align:start position:0% + +Okay. So what are the tests? So there + + align:start position:0% +Okay. So what are the tests? So there + + + align:start position:0% +Okay. So what are the tests? So there +are the comparison test. + + align:start position:0% + + + + align:start position:0% + +Let me just first write down the test. + + align:start position:0% +Let me just first write down the test. + + + align:start position:0% +Let me just first write down the test. +So the comparison test and there was two + + align:start position:0% +So the comparison test and there was two + + + align:start position:0% +So the comparison test and there was two +versions. Version A and version B. + + align:start position:0% +versions. Version A and version B. + + + align:start position:0% +versions. Version A and version B. +Then there was the ratio test. + + align:start position:0% + + + + align:start position:0% + +And then there was the root test. + + align:start position:0% + + + + align:start position:0% + +the ratio test and the root test they + + align:start position:0% +the ratio test and the root test they + + + align:start position:0% +the ratio test and the root test they +are both offsprings of the geometric + + align:start position:0% +are both offsprings of the geometric + + + align:start position:0% +are both offsprings of the geometric +series right in both of these you got + + align:start position:0% +series right in both of these you got + + + align:start position:0% +series right in both of these you got +let's just talk about these first uh the + + align:start position:0% +let's just talk about these first uh the + + + align:start position:0% +let's just talk about these first uh the +ratio test was looking at this + + align:start position:0% +ratio test was looking at this + + + align:start position:0% +ratio test was looking at this +ratio of a n a divided by a n a n + 1 / + + align:start position:0% +ratio of a n a divided by a n a n + 1 / + + + align:start position:0% +ratio of a n a divided by a n a n + 1 / +a n so you are implicitly assuming + + align:start position:0% +a n so you are implicitly assuming + + + align:start position:0% +a n so you are implicitly assuming +that the a does not vanish not zero. + + align:start position:0% +that the a does not vanish not zero. + + + align:start position:0% +that the a does not vanish not zero. +Right? So you can form this ratio and + + align:start position:0% +Right? So you can form this ratio and + + + align:start position:0% +Right? So you can form this ratio and +then if this limit here as n goes to + + align:start position:0% +then if this limit here as n goes to + + + align:start position:0% +then if this limit here as n goes to +infinity if this limit here is less than + + align:start position:0% +infinity if this limit here is less than + + + align:start position:0% +infinity if this limit here is less than +one + + align:start position:0% +one + + + align:start position:0% +one +then then uh the ratio test say that uh + + align:start position:0% +then then uh the ratio test say that uh + + + align:start position:0% +then then uh the ratio test say that uh +the series was convergent. + + align:start position:0% +the series was convergent. + + + align:start position:0% +the series was convergent. +If the ratio was bigger than one then + + align:start position:0% +If the ratio was bigger than one then + + + align:start position:0% +If the ratio was bigger than one then +this ordinary element a n would not even + + align:start position:0% +this ordinary element a n would not even + + + align:start position:0% +this ordinary element a n would not even +go to zero. Right? So this here is so + + align:start position:0% +go to zero. Right? So this here is so + + + align:start position:0% +go to zero. Right? So this here is so +that in this case here maybe maybe I'll + + align:start position:0% +that in this case here maybe maybe I'll + + + align:start position:0% +that in this case here maybe maybe I'll +write it over here. + + align:start position:0% + + + + align:start position:0% + +So for the ratio test, + + align:start position:0% + + + + align:start position:0% + +for the ratio test, you assume that a + + align:start position:0% +for the ratio test, you assume that a + + + align:start position:0% +for the ratio test, you assume that a +none of the a + + align:start position:0% +none of the a + + + align:start position:0% +none of the a +and you're looking at a n + one / n. + + align:start position:0% +and you're looking at a n + one / n. + + + align:start position:0% +and you're looking at a n + one / n. +And if this limit here, + + align:start position:0% +And if this limit here, + + + align:start position:0% +And if this limit here, +let's call this limit, let's assume that + + align:start position:0% +let's call this limit, let's assume that + + + align:start position:0% +let's call this limit, let's assume that +the limit exists. Of course, it may not + + align:start position:0% +the limit exists. Of course, it may not + + + align:start position:0% +the limit exists. Of course, it may not +exist, right? But if the limit existed. + + align:start position:0% +exist, right? But if the limit existed. + + + align:start position:0% +exist, right? But if the limit existed. +So if if C here is less than one, right? + + align:start position:0% +So if if C here is less than one, right? + + + align:start position:0% +So if if C here is less than one, right? +It's always not negative. These are non + + align:start position:0% +It's always not negative. These are non + + + align:start position:0% +It's always not negative. These are non +negative numbers. See is is less than + + align:start position:0% +negative numbers. See is is less than + + + align:start position:0% +negative numbers. See is is less than +one, then the series is converted. + + align:start position:0% + + + + align:start position:0% + +If this C here is strictly bigger than + + align:start position:0% +If this C here is strictly bigger than + + + align:start position:0% +If this C here is strictly bigger than +one, this implies that the series + + align:start position:0% +one, this implies that the series + + + align:start position:0% +one, this implies that the series +is diverted. + + align:start position:0% + + + + align:start position:0% + +And if the C was equal to one then it's + + align:start position:0% +And if the C was equal to one then it's + + + align:start position:0% +And if the C was equal to one then it's +unclear + + align:start position:0% + + + + align:start position:0% + +and so unclear which means that further + + align:start position:0% +and so unclear which means that further + + + align:start position:0% +and so unclear which means that further +test are needed. + + align:start position:0% + + + + align:start position:0% + +And so now + + align:start position:0% +And so now + + + align:start position:0% +And so now +um + + align:start position:0% +um + + + align:start position:0% +um +so that's the ratio test and the root + + align:start position:0% +so that's the ratio test and the root + + + align:start position:0% +so that's the ratio test and the root +test was similar. + + align:start position:0% +test was similar. + + + align:start position:0% +test was similar. +the root test where so you're looking at + + align:start position:0% +the root test where so you're looking at + + + align:start position:0% +the root test where so you're looking at +the AM you take the so this is the root + + align:start position:0% +the AM you take the so this is the root + + + align:start position:0% +the AM you take the so this is the root +test and again this is tested by + + align:start position:0% +test and again this is tested by + + + align:start position:0% +test and again this is tested by +comparing it to the geometric series so + + align:start position:0% +comparing it to the geometric series so + + + align:start position:0% +comparing it to the geometric series so +the root test + + align:start position:0% +the root test + + + align:start position:0% +the root test +so you take the am + + align:start position:0% +so you take the am + + + align:start position:0% +so you take the am +take the nth root of this + + align:start position:0% +take the nth root of this + + + align:start position:0% +take the nth root of this +and you're looking at the limit here and + + align:start position:0% +and you're looking at the limit here and + + + align:start position:0% +and you're looking at the limit here and +we actually looked at the name soup. + + align:start position:0% +we actually looked at the name soup. + + + align:start position:0% +we actually looked at the name soup. +I write in the new soup. Reason why I + + align:start position:0% +I write in the new soup. Reason why I + + + align:start position:0% +I write in the new soup. Reason why I +want the new soup is + + align:start position:0% +want the new soup is + + + align:start position:0% +want the new soup is +that I want to make sure it's later on I + + align:start position:0% +that I want to make sure it's later on I + + + align:start position:0% +that I want to make sure it's later on I +want to apply more generally. Okay. So I + + align:start position:0% +want to apply more generally. Okay. So I + + + align:start position:0% +want to apply more generally. Okay. So I +have uh so if the loom soup here was um + + align:start position:0% +have uh so if the loom soup here was um + + + align:start position:0% +have uh so if the loom soup here was um +was less than one is called soup. It's + + align:start position:0% +was less than one is called soup. It's + + + align:start position:0% +was less than one is called soup. It's +called C. If if C here is less than one + + align:start position:0% +called C. If if C here is less than one + + + align:start position:0% +called C. If if C here is less than one +then uh series is convergence. + + align:start position:0% + + + + align:start position:0% + +True. If the C is bigger than one series + + align:start position:0% +True. If the C is bigger than one series + + + align:start position:0% +True. If the C is bigger than one series +is divergent. This fails the most basic + + align:start position:0% +is divergent. This fails the most basic + + + align:start position:0% +is divergent. This fails the most basic +test divergence. + + align:start position:0% +test divergence. + + + align:start position:0% +test divergence. +And again uh three if C is equal to one + + align:start position:0% +And again uh three if C is equal to one + + + align:start position:0% +And again uh three if C is equal to one +then it's unclear for test or leave it. + + align:start position:0% + + + + align:start position:0% + +That was the that was those two tests. + + align:start position:0% +That was the that was those two tests. + + + align:start position:0% +That was the that was those two tests. +The comparison tests, let's get back to + + align:start position:0% +The comparison tests, let's get back to + + + align:start position:0% +The comparison tests, let's get back to +that. The comparison test had two parts + + align:start position:0% +that. The comparison test had two parts + + + align:start position:0% +that. The comparison test had two parts +that you had suppose you had a n and bn. + + align:start position:0% +that you had suppose you had a n and bn. + + + align:start position:0% +that you had suppose you had a n and bn. +The first part is this statement that if + + align:start position:0% +The first part is this statement that if + + + align:start position:0% +The first part is this statement that if +you have two series, one based on the a + + align:start position:0% +you have two series, one based on the a + + + align:start position:0% +you have two series, one based on the a +series based on the bn. If you have this + + align:start position:0% +series based on the bn. If you have this + + + align:start position:0% +series based on the bn. If you have this +if BN + + align:start position:0% +if BN + + + align:start position:0% +if BN +so this if if this + + align:start position:0% +so this if if this + + + align:start position:0% +so this if if this +is converted + + align:start position:0% + + + + align:start position:0% + +then it fires like this it's converted + + align:start position:0% + + + + align:start position:0% + +right and this is sometimes used both + + align:start position:0% +right and this is sometimes used both + + + align:start position:0% +right and this is sometimes used both +exactly like this and it's also + + align:start position:0% +exactly like this and it's also + + + align:start position:0% +exactly like this and it's also +sometimes used where you know that this + + align:start position:0% +sometimes used where you know that this + + + align:start position:0% +sometimes used where you know that this +one here is divergent and so you + + align:start position:0% +one here is divergent and so you + + + align:start position:0% +one here is divergent and so you +conclude that this + + align:start position:0% + + + + align:start position:0% + +The other part of the comparison test + + align:start position:0% +The other part of the comparison test + + + align:start position:0% +The other part of the comparison test +was if you had the limit here if this + + align:start position:0% +was if you had the limit here if this + + + align:start position:0% +was if you had the limit here if this +limit here exist and it was some L + + align:start position:0% +limit here exist and it was some L + + + align:start position:0% +limit here exist and it was some L +then actually it it say that let's say L + + align:start position:0% +then actually it it say that let's say L + + + align:start position:0% +then actually it it say that let's say L +here is not equal to Z + + align:start position:0% +here is not equal to Z + + + align:start position:0% +here is not equal to Z +then then uh then um then um If + + align:start position:0% +then then uh then um then um If + + + align:start position:0% +then then uh then um then um If +if one of them is converging the other + + align:start position:0% +if one of them is converging the other + + + align:start position:0% +if one of them is converging the other +one is also converging. So + + align:start position:0% +one is also converging. So + + + align:start position:0% +one is also converging. So +a + + align:start position:0% +a + + + align:start position:0% +a +b + + align:start position:0% +b + + + align:start position:0% +b +is converted + + align:start position:0% + + + + align:start position:0% + +that a + + align:start position:0% + + + + align:start position:0% + +and vice versa is actually equivalent. + + align:start position:0% + + + + align:start position:0% + +So those were the three tests that we + + align:start position:0% +So those were the three tests that we + + + align:start position:0% +So those were the three tests that we +really went through. There was a few + + align:start position:0% +really went through. There was a few + + + align:start position:0% +really went through. There was a few +other tests like again this alternating + + align:start position:0% +other tests like again this alternating + + + align:start position:0% +other tests like again this alternating +series test that sort of proved but it's + + align:start position:0% +series test that sort of proved but it's + + + align:start position:0% +series test that sort of proved but it's +not being unmet and you will be trapped + + align:start position:0% +not being unmet and you will be trapped + + + align:start position:0% +not being unmet and you will be trapped +to this later. + + align:start position:0% +to this later. + + + align:start position:0% +to this later. +>> Yeah. + + align:start position:0% +>> Yeah. + + + align:start position:0% +>> Yeah. +>> Um are there like patterns of like when + + align:start position:0% +>> Um are there like patterns of like when + + + align:start position:0% +>> Um are there like patterns of like when +we should apply which tests? + + align:start position:0% +we should apply which tests? + + + align:start position:0% +we should apply which tests? +>> Yeah. No. And I want to get to this + + align:start position:0% +>> Yeah. No. And I want to get to this + + + align:start position:0% +>> Yeah. No. And I want to get to this +um I want to get to this in just a + + align:start position:0% +um I want to get to this in just a + + + align:start position:0% +um I want to get to this in just a +second. + + align:start position:0% +second. + + + align:start position:0% +second. +Uh + + align:start position:0% +Uh + + + align:start position:0% +Uh +let me let me just say a couple of words + + align:start position:0% +let me let me just say a couple of words + + + align:start position:0% +let me let me just say a couple of words +first and then let let me jump to some + + align:start position:0% +first and then let let me jump to some + + + align:start position:0% +first and then let let me jump to some +of the examples of problems and then + + align:start position:0% +of the examples of problems and then + + + align:start position:0% +of the examples of problems and then +I'll come back and I'll review a little + + align:start position:0% +I'll come back and I'll review a little + + + align:start position:0% +I'll come back and I'll review a little +more. So uh but let's just talk about + + align:start position:0% +more. So uh but let's just talk about + + + align:start position:0% +more. So uh but let's just talk about +power shares. + + align:start position:0% +power shares. + + + align:start position:0% +power shares. +Um maybe maybe a little + + align:start position:0% +Um maybe maybe a little + + + align:start position:0% +Um maybe maybe a little +whether uh just now when you were asking + + align:start position:0% +whether uh just now when you were asking + + + align:start position:0% +whether uh just now when you were asking +the question + + align:start position:0% +the question + + + align:start position:0% +the question +uh no this this just review the power + + align:start position:0% +uh no this this just review the power + + + align:start position:0% +uh no this this just review the power +series. + + align:start position:0% + + + + align:start position:0% + +So a power series was a series but it + + align:start position:0% +So a power series was a series but it + + + align:start position:0% +So a power series was a series but it +was something that also defined a + + align:start position:0% +was something that also defined a + + + align:start position:0% +was something that also defined a +function right and so you take so you + + align:start position:0% +function right and so you take so you + + + align:start position:0% +function right and so you take so you +have a you have a u + + align:start position:0% +have a you have a u + + + align:start position:0% +have a you have a u +you have + + align:start position:0% +you have + + + align:start position:0% +you have +see power series + + align:start position:0% + + + + align:start position:0% + +so you have a sequence a + + align:start position:0% +so you have a sequence a + + + align:start position:0% +so you have a sequence a +and then you think for each x but x but + + align:start position:0% +and then you think for each x but x but + + + align:start position:0% +and then you think for each x but x but +x is being fixed you form a series + + align:start position:0% +x is being fixed you form a series + + + align:start position:0% +x is being fixed you form a series +and this is the series that you form + + align:start position:0% + + + + align:start position:0% + +and so for each x you can ask is this + + align:start position:0% +and so for each x you can ask is this + + + align:start position:0% +and so for each x you can ask is this +series convergent or not right this here + + align:start position:0% +series convergent or not right this here + + + align:start position:0% +series convergent or not right this here +is called a power series + + align:start position:0% +is called a power series + + + align:start position:0% +is called a power series +and uh and the the key point for a power + + align:start position:0% +and uh and the the key point for a power + + + align:start position:0% +and uh and the the key point for a power +series is uh again of course whether or + + align:start position:0% +series is uh again of course whether or + + + align:start position:0% +series is uh again of course whether or +not this is convergence + + align:start position:0% +not this is convergence + + + align:start position:0% +not this is convergence +and this give rise to the radius of + + align:start position:0% +and this give rise to the radius of + + + align:start position:0% +and this give rise to the radius of +convergence. + + align:start position:0% + + + + align:start position:0% + +And so the radius of convergence was + + align:start position:0% +And so the radius of convergence was + + + align:start position:0% +And so the radius of convergence was +that we defined we looked at at le + + align:start position:0% + + + + align:start position:0% + +of the nth root + + align:start position:0% +of the nth root + + + align:start position:0% +of the nth root +of a n like that. + + align:start position:0% +of a n like that. + + + align:start position:0% +of a n like that. +Right? And we looked at when this thing + + align:start position:0% +Right? And we looked at when this thing + + + align:start position:0% +Right? And we looked at when this thing +here + + align:start position:0% +here + + + align:start position:0% +here +uh if this thing here is uh right so we + + align:start position:0% +uh if this thing here is uh right so we + + + align:start position:0% +uh if this thing here is uh right so we +define this thing here + + align:start position:0% +define this thing here + + + align:start position:0% +define this thing here +and so we get this thing here and then + + align:start position:0% +and so we get this thing here and then + + + align:start position:0% +and so we get this thing here and then +we define the radius of convergence. So + + align:start position:0% +we define the radius of convergence. So + + + align:start position:0% +we define the radius of convergence. So +the radius of conver + + align:start position:0% +the radius of conver + + + align:start position:0% +the radius of conver +of convergence + + align:start position:0% + + + + align:start position:0% + +this is r and the r is 1 / + + align:start position:0% +this is r and the r is 1 / + + + align:start position:0% +this is r and the r is 1 / +This should + + align:start position:0% + + + + align:start position:0% + +but there was an understanding in this. + + align:start position:0% +but there was an understanding in this. + + + align:start position:0% +but there was an understanding in this. +The understanding is that if this number + + align:start position:0% +The understanding is that if this number + + + align:start position:0% +The understanding is that if this number +here this number here you this one of + + align:start position:0% +here this number here you this one of + + + align:start position:0% +here this number here you this one of +potential could be infinite. Right? + + align:start position:0% +potential could be infinite. Right? + + + align:start position:0% +potential could be infinite. Right? +If it was infinite it meant that this + + align:start position:0% +If it was infinite it meant that this + + + align:start position:0% +If it was infinite it meant that this +thing here was zero. + + align:start position:0% +thing here was zero. + + + align:start position:0% +thing here was zero. +Right? If this one here is is infinity, + + align:start position:0% +Right? If this one here is is infinity, + + + align:start position:0% +Right? If this one here is is infinity, +if this here is zero, then this here + + align:start position:0% +if this here is zero, then this here + + + align:start position:0% +if this here is zero, then this here +would be infinity. + + align:start position:0% +would be infinity. + + + align:start position:0% +would be infinity. +Okay, so that's so that's like a + + align:start position:0% +Okay, so that's so that's like a + + + align:start position:0% +Okay, so that's so that's like a +convention in this particular case, + + align:start position:0% +convention in this particular case, + + + align:start position:0% +convention in this particular case, +right? I mean, usually we don't want to + + align:start position:0% +right? I mean, usually we don't want to + + + align:start position:0% +right? I mean, usually we don't want to +divide by zero that kind of stuff, but + + align:start position:0% +divide by zero that kind of stuff, but + + + align:start position:0% +divide by zero that kind of stuff, but +this is convention in this particular + + align:start position:0% +this is convention in this particular + + + align:start position:0% +this is convention in this particular +case. + + align:start position:0% +case. + + + align:start position:0% +case. +And so using this radius of convergence, + + align:start position:0% +And so using this radius of convergence, + + + align:start position:0% +And so using this radius of convergence, +we saw that if you take a power series, + + align:start position:0% +we saw that if you take a power series, + + + align:start position:0% +we saw that if you take a power series, +if you have any power shares like this, + + align:start position:0% +if you have any power shares like this, + + + align:start position:0% +if you have any power shares like this, +there have any power shares like this, + + align:start position:0% +there have any power shares like this, + + + align:start position:0% +there have any power shares like this, +it's going to be if this here is R and + + align:start position:0% +it's going to be if this here is R and + + + align:start position:0% +it's going to be if this here is R and +again R could be zero or it could be + + align:start position:0% +again R could be zero or it could be + + + align:start position:0% +again R could be zero or it could be +infinity, right? But if this is R. So I + + align:start position:0% +infinity, right? But if this is R. So I + + + align:start position:0% +infinity, right? But if this is R. So I +should write this minus + + align:start position:0% +should write this minus + + + align:start position:0% +should write this minus +then the for x in between for x not + + align:start position:0% +then the for x in between for x not + + + align:start position:0% +then the for x in between for x not +including the end point but in between + + align:start position:0% +including the end point but in between + + + align:start position:0% +including the end point but in between +the series is converging right the power + + align:start position:0% +the series is converging right the power + + + align:start position:0% +the series is converging right the power +series is converging and outside here + + align:start position:0% +series is converging and outside here + + + align:start position:0% +series is converging and outside here +it's it's diverging + + align:start position:0% + + + + align:start position:0% + +outside it's diverging here it's + + align:start position:0% +outside it's diverging here it's + + + align:start position:0% +outside it's diverging here it's +converting + + align:start position:0% + + + + align:start position:0% + +and and at those two points here + + align:start position:0% + + + + align:start position:0% + +further test are needed right so this is + + align:start position:0% +further test are needed right so this is + + + align:start position:0% +further test are needed right so this is +always this picture so this come back to + + align:start position:0% +always this picture so this come back to + + + align:start position:0% +always this picture so this come back to +your question about you know which test + + align:start position:0% +your question about you know which test + + + align:start position:0% +your question about you know which test +I mean of course you can use any test + + align:start position:0% +I mean of course you can use any test + + + align:start position:0% +I mean of course you can use any test +you want but when I you know like if + + align:start position:0% +you want but when I you know like if + + + align:start position:0% +you want but when I you know like if +you're looking at a series you can use + + align:start position:0% +you're looking at a series you can use + + + align:start position:0% +you're looking at a series you can use +whatever test you want but if it was a + + align:start position:0% +whatever test you want but if it was a + + + align:start position:0% +whatever test you want but if it was a +power series you already know that + + align:start position:0% +power series you already know that + + + align:start position:0% +power series you already know that +there's some integral around here where + + align:start position:0% +there's some integral around here where + + + align:start position:0% +there's some integral around here where +it's convergent and then there's a + + align:start position:0% +it's convergent and then there's a + + + align:start position:0% +it's convergent and then there's a +question about the end points, right? + + align:start position:0% +question about the end points, right? + + + align:start position:0% +question about the end points, right? +And so um okay, so now let's look at + + align:start position:0% +And so um okay, so now let's look at + + + align:start position:0% +And so um okay, so now let's look at +let's look at some examples of this + + align:start position:0% +let's look at some examples of this + + + align:start position:0% +let's look at some examples of this +and suppose you look at + + align:start position:0% +and suppose you look at + + + align:start position:0% +and suppose you look at +and so + + align:start position:0% + + + + align:start position:0% + +it's usually not too hard to use either + + align:start position:0% +it's usually not too hard to use either + + + align:start position:0% +it's usually not too hard to use either +either the roof + + align:start position:0% +either the roof + + + align:start position:0% +either the roof +to to use either um + + align:start position:0% +to to use either um + + + align:start position:0% +to to use either um +the this here was based on the root test + + align:start position:0% +the this here was based on the root test + + + align:start position:0% +the this here was based on the root test +to either use the root test or the ratio + + align:start position:0% +to either use the root test or the ratio + + + align:start position:0% +to either use the root test or the ratio +test for power but but you can take + + align:start position:0% +test for power but but you can take + + + align:start position:0% +test for power but but you can take +advantage of it sometimes slightly + + align:start position:0% +advantage of it sometimes slightly + + + align:start position:0% +advantage of it sometimes slightly +easier. So let's look at two examples + + align:start position:0% +easier. So let's look at two examples + + + align:start position:0% +easier. So let's look at two examples +here. So suppose that + + align:start position:0% +here. So suppose that + + + align:start position:0% +here. So suppose that +that you ask to find the the radius of + + align:start position:0% +that you ask to find the the radius of + + + align:start position:0% +that you ask to find the the radius of +convergence + + align:start position:0% + + + + align:start position:0% + +for the power sh + + align:start position:0% + + + + align:start position:0% + +and then let's say that this is n to the + + align:start position:0% +and then let's say that this is n to the + + + align:start position:0% +and then let's say that this is n to the +fifth power x. + + align:start position:0% +fifth power x. + + + align:start position:0% +fifth power x. +So suppose that you are this is a power + + align:start position:0% +So suppose that you are this is a power + + + align:start position:0% +So suppose that you are this is a power +series you're given + + align:start position:0% +series you're given + + + align:start position:0% +series you're given +and you want to find the radius of + + align:start position:0% +and you want to find the radius of + + + align:start position:0% +and you want to find the radius of +convergence right you can either just + + align:start position:0% +convergence right you can either just + + + align:start position:0% +convergence right you can either just +form you know do + + align:start position:0% +form you know do + + + align:start position:0% +form you know do +plug it into this test right or you can + + align:start position:0% +plug it into this test right or you can + + + align:start position:0% +plug it into this test right or you can +just say okay we just apply we know that + + align:start position:0% +just say okay we just apply we know that + + + align:start position:0% +just say okay we just apply we know that +it's some interval and I just want to + + align:start position:0% +it's some interval and I just want to + + + align:start position:0% +it's some interval and I just want to +see for which x does this here converge + + align:start position:0% +see for which x does this here converge + + + align:start position:0% +see for which x does this here converge +so if I looked in this case you might + + align:start position:0% +so if I looked in this case you might + + + align:start position:0% +so if I looked in this case you might +find it slightly easier to do the the + + align:start position:0% +find it slightly easier to do the the + + + align:start position:0% +find it slightly easier to do the the +root test. So if you're looking at the n + + align:start position:0% +root test. So if you're looking at the n + + + align:start position:0% +root test. So if you're looking at the n ++ one elements in this series the n + + align:start position:0% ++ one elements in this series the n + + + align:start position:0% ++ one elements in this series the n +elements sorry the n elements would be + + align:start position:0% +elements sorry the n elements would be + + + align:start position:0% +elements sorry the n elements would be +this to the fifth power think about x as + + align:start position:0% +this to the fifth power think about x as + + + align:start position:0% +this to the fifth power think about x as +being fixed right and you're asking for + + align:start position:0% +being fixed right and you're asking for + + + align:start position:0% +being fixed right and you're asking for +which and then you want to for given x + + align:start position:0% +which and then you want to for given x + + + align:start position:0% +which and then you want to for given x +you want to determine whether the series + + align:start position:0% +you want to determine whether the series + + + align:start position:0% +you want to determine whether the series +this series here is convergent right + + align:start position:0% +this series here is convergent right + + + align:start position:0% +this series here is convergent right +so if you using the root test you would + + align:start position:0% +so if you using the root test you would + + + align:start position:0% +so if you using the root test you would +look at this one here and you might find + + align:start position:0% +look at this one here and you might find + + + align:start position:0% +look at this one here and you might find +in this case slightly easier to use the + + align:start position:0% +in this case slightly easier to use the + + + align:start position:0% +in this case slightly easier to use the +root test. + + align:start position:0% +root test. + + + align:start position:0% +root test. +So if you're looking at this, this thing + + align:start position:0% +So if you're looking at this, this thing + + + align:start position:0% +So if you're looking at this, this thing +here is now n + 1 + + align:start position:0% +here is now n + 1 + + + align:start position:0% +here is now n + 1 +to the 5th power * x to the n + 1 + + align:start position:0% +to the 5th power * x to the n + 1 + + + align:start position:0% +to the 5th power * x to the n + 1 +/ n 5th power * x to the n. Right? + + align:start position:0% +/ n 5th power * x to the n. Right? + + + align:start position:0% +/ n 5th power * x to the n. Right? +That's a ratio. + + align:start position:0% +That's a ratio. + + + align:start position:0% +That's a ratio. +And so of course you can write this in + + align:start position:0% +And so of course you can write this in + + + align:start position:0% +And so of course you can write this in +here. This is like x n + 1 * by itself + + align:start position:0% +here. This is like x n + 1 * by itself + + + align:start position:0% +here. This is like x n + 1 * by itself +five times + + align:start position:0% +five times + + + align:start position:0% +five times +divided by n * by itself five times and + + align:start position:0% +divided by n * by itself five times and + + + align:start position:0% +divided by n * by itself five times and +then this thing here you can write as x + + align:start position:0% +then this thing here you can write as x + + + align:start position:0% +then this thing here you can write as x +to the n * x + + align:start position:0% +to the n * x + + + align:start position:0% +to the n * x +uh over x to the n. + + align:start position:0% +uh over x to the n. + + + align:start position:0% +uh over x to the n. +So you see this thing here you can then + + align:start position:0% +So you see this thing here you can then + + + align:start position:0% +So you see this thing here you can then +think about as n + 1 / n + + align:start position:0% +think about as n + 1 / n + + + align:start position:0% +think about as n + 1 / n +to the fifth power + + align:start position:0% +to the fifth power + + + align:start position:0% +to the fifth power +um and and time sorry time x right + + align:start position:0% +um and and time sorry time x right + + + align:start position:0% +um and and time sorry time x right +and I can write this in here in the + + align:start position:0% +and I can write this in here in the + + + align:start position:0% +and I can write this in here in the +usual way if you want you can write it + + align:start position:0% +usual way if you want you can write it + + + align:start position:0% +usual way if you want you can write it +as 1 + 1 / n I'm dividing by n in both + + align:start position:0% +as 1 + 1 / n I'm dividing by n in both + + + align:start position:0% +as 1 + 1 / n I'm dividing by n in both +denominator and denominator so you can + + align:start position:0% +denominator and denominator so you can + + + align:start position:0% +denominator and denominator so you can +write it like this to the fifth power * + + align:start position:0% +write it like this to the fifth power * + + + align:start position:0% +write it like this to the fifth power * +x. + + align:start position:0% +x. + + + align:start position:0% +x. +And so now + + align:start position:0% +And so now + + + align:start position:0% +And so now +the root test it's asking + + align:start position:0% +the root test it's asking + + + align:start position:0% +the root test it's asking +it's asking whether this the absolute + + align:start position:0% +it's asking whether this the absolute + + + align:start position:0% +it's asking whether this the absolute +value of this root test would be then + + align:start position:0% +value of this root test would be then + + + align:start position:0% +value of this root test would be then +asking if the limit here of x n + one + + align:start position:0% +asking if the limit here of x n + one + + + align:start position:0% +asking if the limit here of x n + one +sorry n + 1 + + align:start position:0% +sorry n + 1 + + + align:start position:0% +sorry n + 1 +if this here has a limit + + align:start position:0% +if this here has a limit + + + align:start position:0% +if this here has a limit +and then it's asking you if that limit + + align:start position:0% +and then it's asking you if that limit + + + align:start position:0% +and then it's asking you if that limit +is less than one if it has a limit and + + align:start position:0% +is less than one if it has a limit and + + + align:start position:0% +is less than one if it has a limit and +the limit is less than one when the + + align:start position:0% +the limit is less than one when the + + + align:start position:0% +the limit is less than one when the +series is converting and it's diverse + + align:start position:0% +series is converting and it's diverse + + + align:start position:0% +series is converting and it's diverse +one. But in this case, this thing here + + align:start position:0% +one. But in this case, this thing here + + + align:start position:0% +one. But in this case, this thing here +this ratio here + + align:start position:0% +this ratio here + + + align:start position:0% +this ratio here +is 1 + 1 + + align:start position:0% +is 1 + 1 + + + align:start position:0% +is 1 + 1 +to the 5th power * x + + align:start position:0% +to the 5th power * x + + + align:start position:0% +to the 5th power * x +that this is all non negative. So the + + align:start position:0% +that this is all non negative. So the + + + align:start position:0% +that this is all non negative. So the +absolute value just go over here. + + align:start position:0% + + + + align:start position:0% + +The algebraic property of the limit say + + align:start position:0% +The algebraic property of the limit say + + + align:start position:0% +The algebraic property of the limit say +that this this one here goes to zero and + + align:start position:0% +that this this one here goes to zero and + + + align:start position:0% +that this this one here goes to zero and +so raised to the fifth power still go to + + align:start position:0% +so raised to the fifth power still go to + + + align:start position:0% +so raised to the fifth power still go to +zero right it's multiply bunch of + + align:start position:0% +zero right it's multiply bunch of + + + align:start position:0% +zero right it's multiply bunch of +sequences five times together that go to + + align:start position:0% +sequences five times together that go to + + + align:start position:0% +sequences five times together that go to +zero to one so so this here this goes to + + align:start position:0% +zero to one so so this here this goes to + + + align:start position:0% +zero to one so so this here this goes to +one and so even raised to fifth power + + align:start position:0% +one and so even raised to fifth power + + + align:start position:0% +one and so even raised to fifth power +still go to one so this here goes to to + + align:start position:0% +still go to one so this here goes to to + + + align:start position:0% +still go to one so this here goes to to +the norm of x right and so the ratio + + align:start position:0% +the norm of x right and so the ratio + + + align:start position:0% +the norm of x right and so the ratio +test would be that if x so ratio test + + align:start position:0% +test would be that if x so ratio test + + + align:start position:0% +test would be that if x so ratio test +gives you + + align:start position:0% + + + + align:start position:0% + +is that if this norm here is less than + + align:start position:0% +is that if this norm here is less than + + + align:start position:0% +is that if this norm here is less than +one then this series is convergent. + + align:start position:0% +one then this series is convergent. + + + align:start position:0% +one then this series is convergent. +If the norm here is bigger than one the + + align:start position:0% +If the norm here is bigger than one the + + + align:start position:0% +If the norm here is bigger than one the +ratio is divergent + + align:start position:0% +ratio is divergent + + + align:start position:0% +ratio is divergent +and it's unclear if the norm is equal to + + align:start position:0% +and it's unclear if the norm is equal to + + + align:start position:0% +and it's unclear if the norm is equal to +one. So in other words you see that the + + align:start position:0% +one. So in other words you see that the + + + align:start position:0% +one. So in other words you see that the +ratio test here gives you directly that + + align:start position:0% +ratio test here gives you directly that + + + align:start position:0% +ratio test here gives you directly that +the radius of convergence is one. Right? + + align:start position:0% +the radius of convergence is one. Right? + + + align:start position:0% +the radius of convergence is one. Right? +So and and of course you could apply the + + align:start position:0% +So and and of course you could apply the + + + align:start position:0% +So and and of course you could apply the +root test, right? + + align:start position:0% +root test, right? + + + align:start position:0% +root test, right? +The root test is great on this here. + + align:start position:0% +The root test is great on this here. + + + align:start position:0% +The root test is great on this here. +It's ah it's a little bit more know I + + align:start position:0% +It's ah it's a little bit more know I + + + align:start position:0% +It's ah it's a little bit more know I +mean you have to do a little bit more + + align:start position:0% +mean you have to do a little bit more + + + align:start position:0% +mean you have to do a little bit more +argument. It's not very hard but it + + align:start position:0% +argument. It's not very hard but it + + + align:start position:0% +argument. It's not very hard but it +actually in this case the root ratio + + align:start position:0% +actually in this case the root ratio + + + align:start position:0% +actually in this case the root ratio +test would be easier to it would be less + + align:start position:0% +test would be easier to it would be less + + + align:start position:0% +test would be easier to it would be less +to argue than in the root test. + + align:start position:0% +to argue than in the root test. + + + align:start position:0% +to argue than in the root test. +Let's do one more example of this. + + align:start position:0% +Let's do one more example of this. + + + align:start position:0% +Let's do one more example of this. +So maybe I'll just switch a little bit + + align:start position:0% +So maybe I'll just switch a little bit + + + align:start position:0% +So maybe I'll just switch a little bit +to and then I'll come back and review + + align:start position:0% +to and then I'll come back and review + + + align:start position:0% +to and then I'll come back and review +some more stuff. I will um I'll just + + align:start position:0% +some more stuff. I will um I'll just + + + align:start position:0% +some more stuff. I will um I'll just +talk about a few of the problems that I + + align:start position:0% +talk about a few of the problems that I + + + align:start position:0% +talk about a few of the problems that I +added to the end of my review notes + + align:start position:0% +added to the end of my review notes + + + align:start position:0% +added to the end of my review notes +again. I post this with these problems. + + align:start position:0% +again. I post this with these problems. + + + align:start position:0% +again. I post this with these problems. +Um and and obviously they are I mean + + align:start position:0% +Um and and obviously they are I mean + + + align:start position:0% +Um and and obviously they are I mean +it's not exactly problems on the met but + + align:start position:0% + + + + align:start position:0% + +Okay. Also another thing I want to say + + align:start position:0% +Okay. Also another thing I want to say + + + align:start position:0% +Okay. Also another thing I want to say +is that uh that the the homework uh is + + align:start position:0% +is that uh that the the homework uh is + + + align:start position:0% +is that uh that the the homework uh is +graded up to an including four. So I + + align:start position:0% +graded up to an including four. So I + + + align:start position:0% +graded up to an including four. So I +wasn't actually aware of over the + + align:start position:0% +wasn't actually aware of over the + + + align:start position:0% +wasn't actually aware of over the +weekend. It was supposed to be handed + + align:start position:0% +weekend. It was supposed to be handed + + + align:start position:0% +weekend. It was supposed to be handed +back within latest a week of when you + + align:start position:0% +back within latest a week of when you + + + align:start position:0% +back within latest a week of when you +handed it in and I just discovered it + + align:start position:0% +handed it in and I just discovered it + + + align:start position:0% +handed it in and I just discovered it +over the weekend that it was uh some of + + align:start position:0% +over the weekend that it was uh some of + + + align:start position:0% +over the weekend that it was uh some of +them were late. So, but I it's fixed uh + + align:start position:0% +them were late. So, but I it's fixed uh + + + align:start position:0% +them were late. So, but I it's fixed uh +you know I'm I'm not the grader. There's + + align:start position:0% +you know I'm I'm not the grader. There's + + + align:start position:0% +you know I'm I'm not the grader. There's +two ways that are grading and a greater + + align:start position:0% +two ways that are grading and a greater + + + align:start position:0% +two ways that are grading and a greater +um but it's all fixed now. So the first + + align:start position:0% +um but it's all fixed now. So the first + + + align:start position:0% +um but it's all fixed now. So the first +four are are you know you can review + + align:start position:0% +four are are you know you can review + + + align:start position:0% +four are are you know you can review +those also for the lecture. + + align:start position:0% +those also for the lecture. + + + align:start position:0% +those also for the lecture. +Okay. So the other the other series or + + align:start position:0% +Okay. So the other the other series or + + + align:start position:0% +Okay. So the other the other series or +power series I want to look at is that + + align:start position:0% +power series I want to look at is that + + + align:start position:0% +power series I want to look at is that +so again what is the radius + + align:start position:0% + + + + align:start position:0% + +the thing about power series the nice + + align:start position:0% +the thing about power series the nice + + + align:start position:0% +the thing about power series the nice +thing about power series is that you + + align:start position:0% +thing about power series is that you + + + align:start position:0% +thing about power series is that you +know power series also test about series + + align:start position:0% +know power series also test about series + + + align:start position:0% +know power series also test about series +right so it's like you know + + align:start position:0% + + + + align:start position:0% + +So what is the radius of convergence? + + align:start position:0% + + + + align:start position:0% + +And now the series it's a slightly + + align:start position:0% +And now the series it's a slightly + + + align:start position:0% +And now the series it's a slightly +different series. It's this series here. + + align:start position:0% + + + + align:start position:0% + +So this series. + + align:start position:0% + + + + align:start position:0% + +Okay. And so now let me again I mean you + + align:start position:0% +Okay. And so now let me again I mean you + + + align:start position:0% +Okay. And so now let me again I mean you +could apply the root test. The root test + + align:start position:0% +could apply the root test. The root test + + + align:start position:0% +could apply the root test. The root test +is the one that sort of just give you a + + align:start position:0% +is the one that sort of just give you a + + + align:start position:0% +is the one that sort of just give you a +answer. It always give you an answer, + + align:start position:0% +answer. It always give you an answer, + + + align:start position:0% +answer. It always give you an answer, +but you know it you may have to work + + align:start position:0% +but you know it you may have to work + + + align:start position:0% +but you know it you may have to work +harder to find the nth root. So, and + + align:start position:0% +harder to find the nth root. So, and + + + align:start position:0% +harder to find the nth root. So, and +sometimes it's just easier to use the + + align:start position:0% +sometimes it's just easier to use the + + + align:start position:0% +sometimes it's just easier to use the +ratio test. So, let's use the ratio test + + align:start position:0% +ratio test. So, let's use the ratio test + + + align:start position:0% +ratio test. So, let's use the ratio test +again. So, a n here is n to the 5th + + align:start position:0% +again. So, a n here is n to the 5th + + + align:start position:0% +again. So, a n here is n to the 5th +power x^ n / n factorial. + + align:start position:0% +power x^ n / n factorial. + + + align:start position:0% +power x^ n / n factorial. +So if you're looking at a n + 1 / a n, + + align:start position:0% +So if you're looking at a n + 1 / a n, + + + align:start position:0% +So if you're looking at a n + 1 / a n, +maybe I should maybe let me write over + + align:start position:0% +maybe I should maybe let me write over + + + align:start position:0% +maybe I should maybe let me write over +here. + + align:start position:0% + + + + align:start position:0% + +So if I'm looking at at a n + one a n + + align:start position:0% + + + + align:start position:0% + +so then I have uh n + 1 + + align:start position:0% +so then I have uh n + 1 + + + align:start position:0% +so then I have uh n + 1 +to the 3 power + + align:start position:0% +to the 3 power + + + align:start position:0% +to the 3 power +uh * x to the power n + 1 + + align:start position:0% +uh * x to the power n + 1 + + + align:start position:0% +uh * x to the power n + 1 +um + + align:start position:0% + + + + align:start position:0% + +over n + 1 + + align:start position:0% +over n + 1 + + + align:start position:0% +over n + 1 +that is a n + one and then I have to + + align:start position:0% +that is a n + one and then I have to + + + align:start position:0% +that is a n + one and then I have to +divide by this. But when I divide by a + + align:start position:0% +divide by this. But when I divide by a + + + align:start position:0% +divide by this. But when I divide by a +fraction, it's like multiplying by + + align:start position:0% +fraction, it's like multiplying by + + + align:start position:0% +fraction, it's like multiplying by +the inverse of this. So like this in + + align:start position:0% +the inverse of this. So like this in + + + align:start position:0% +the inverse of this. So like this in +here + + align:start position:0% +here + + + align:start position:0% +here +n + + align:start position:0% +n + + + align:start position:0% +n +power + + align:start position:0% +power + + + align:start position:0% +power +x to the n power like that. + + align:start position:0% +x to the n power like that. + + + align:start position:0% +x to the n power like that. +And so again I can what I again I can uh + + align:start position:0% +And so again I can what I again I can uh + + + align:start position:0% +And so again I can what I again I can uh +I can write this in here as um so if I + + align:start position:0% +I can write this in here as um so if I + + + align:start position:0% +I can write this in here as um so if I +just do like I did before I would have n + + align:start position:0% +just do like I did before I would have n + + + align:start position:0% +just do like I did before I would have n ++ one over n to the fifth power that's + + align:start position:0% ++ one over n to the fifth power that's + + + align:start position:0% ++ one over n to the fifth power that's +when I take this one here and that one + + align:start position:0% +when I take this one here and that one + + + align:start position:0% +when I take this one here and that one +together + + align:start position:0% +together + + + align:start position:0% +together +then I have when I take those two + + align:start position:0% +then I have when I take those two + + + align:start position:0% +then I have when I take those two +together I can get rid of the n here and + + align:start position:0% +together I can get rid of the n here and + + + align:start position:0% +together I can get rid of the n here and +I just get x + + align:start position:0% +I just get x + + + align:start position:0% +I just get x +and then when I look at the ratio of + + align:start position:0% +and then when I look at the ratio of + + + align:start position:0% +and then when I look at the ratio of +these two this one here n + one + + align:start position:0% +these two this one here n + one + + + align:start position:0% +these two this one here n + one +factorial you can think about that as n + + align:start position:0% +factorial you can think about that as n + + + align:start position:0% +factorial you can think about that as n ++ one and then times n factorial. + + align:start position:0% ++ one and then times n factorial. + + + align:start position:0% ++ one and then times n factorial. +So this n factorial cancel out with that + + align:start position:0% +So this n factorial cancel out with that + + + align:start position:0% +So this n factorial cancel out with that +and you're left with n + one. So this is + + align:start position:0% +and you're left with n + one. So this is + + + align:start position:0% +and you're left with n + one. So this is +what you get + + align:start position:0% +what you get + + + align:start position:0% +what you get +and this one here just writing it as we + + align:start position:0% +and this one here just writing it as we + + + align:start position:0% +and this one here just writing it as we +did before dividing this fraction by 1 / + + align:start position:0% +did before dividing this fraction by 1 / + + + align:start position:0% +did before dividing this fraction by 1 / +n in both uh denominator and denominator + + align:start position:0% +n in both uh denominator and denominator + + + align:start position:0% +n in both uh denominator and denominator +and getting this ring here + + align:start position:0% +and getting this ring here + + + align:start position:0% +and getting this ring here +5 * x n + + align:start position:0% +5 * x n + + + align:start position:0% +5 * x n +and now you see that if and this here I + + align:start position:0% +and now you see that if and this here I + + + align:start position:0% +and now you see that if and this here I +guess it should have been absolute value + + align:start position:0% +guess it should have been absolute value + + + align:start position:0% +guess it should have been absolute value +of So it's absolute value on this + + align:start position:0% + + + + align:start position:0% + +like that. + + align:start position:0% +like that. + + + align:start position:0% +like that. +This one here converts to one. + + align:start position:0% +This one here converts to one. + + + align:start position:0% +This one here converts to one. +This one is just x and this converts to + + align:start position:0% +This one is just x and this converts to + + + align:start position:0% +This one is just x and this converts to +x. And then this here goes to infinity. + + align:start position:0% +x. And then this here goes to infinity. + + + align:start position:0% +x. And then this here goes to infinity. +So the ratio here goes to zero. Right? + + align:start position:0% +So the ratio here goes to zero. Right? + + + align:start position:0% +So the ratio here goes to zero. Right? +I'm using the algebraic property of + + align:start position:0% +I'm using the algebraic property of + + + align:start position:0% +I'm using the algebraic property of +limits. So this is converted to zero. + + align:start position:0% +limits. So this is converted to zero. + + + align:start position:0% +limits. So this is converted to zero. +And so you see that it does have a + + align:start position:0% +And so you see that it does have a + + + align:start position:0% +And so you see that it does have a +limit. So the ratio test apply because + + align:start position:0% +limit. So the ratio test apply because + + + align:start position:0% +limit. So the ratio test apply because +that limit is zero for all x. It's going + + align:start position:0% +that limit is zero for all x. It's going + + + align:start position:0% +that limit is zero for all x. It's going +to be converged for all x. So the radius + + align:start position:0% +to be converged for all x. So the radius + + + align:start position:0% +to be converged for all x. So the radius +of convergence in this case + + align:start position:0% + + + + align:start position:0% + +and of course on the midterm don't just + + align:start position:0% +and of course on the midterm don't just + + + align:start position:0% +and of course on the midterm don't just +say that the radius of convergence is + + align:start position:0% +say that the radius of convergence is + + + align:start position:0% +say that the radius of convergence is +infinite explain this thing here and the + + align:start position:0% +infinite explain this thing here and the + + + align:start position:0% +infinite explain this thing here and the +more detailed the better right because + + align:start position:0% +more detailed the better right because + + + align:start position:0% +more detailed the better right because +even if there's some typos you would + + align:start position:0% +even if there's some typos you would + + + align:start position:0% +even if there's some typos you would +definitely get you should definitely get + + align:start position:0% +definitely get you should definitely get + + + align:start position:0% +definitely get you should definitely get +I mean I'm not great in mid either But + + align:start position:0% +I mean I'm not great in mid either But + + + align:start position:0% +I mean I'm not great in mid either But +you you definitely should get positive, + + align:start position:0% +you you definitely should get positive, + + + align:start position:0% +you you definitely should get positive, +right? Yeah. + + align:start position:0% +right? Yeah. + + + align:start position:0% +right? Yeah. +>> So to get R, is it always like you + + align:start position:0% +>> So to get R, is it always like you + + + align:start position:0% +>> So to get R, is it always like you +divide by the limb soup? Cuz like is the + + align:start position:0% +divide by the limb soup? Cuz like is the + + + align:start position:0% +divide by the limb soup? Cuz like is the +thing on the bottom board the limb soup + + align:start position:0% +thing on the bottom board the limb soup + + + align:start position:0% +thing on the bottom board the limb soup +or just the + + align:start position:0% +or just the + + + align:start position:0% +or just the +>> Yeah. So + + align:start position:0% +>> Yeah. So + + + align:start position:0% +>> Yeah. So +So + + align:start position:0% +So + + + align:start position:0% +So +when you take just a complete general sh + + align:start position:0% +when you take just a complete general sh + + + align:start position:0% +when you take just a complete general sh +then + + align:start position:0% +then + + + align:start position:0% +then +then um you then the radius of + + align:start position:0% +then um you then the radius of + + + align:start position:0% +then um you then the radius of +convergence is by definition this this + + align:start position:0% +convergence is by definition this this + + + align:start position:0% +convergence is by definition this this +is related to you. You asked this + + align:start position:0% +is related to you. You asked this + + + align:start position:0% +is related to you. You asked this +question a couple of times ago that + + align:start position:0% +question a couple of times ago that + + + align:start position:0% +question a couple of times ago that +because we started with the RA ratio + + align:start position:0% +because we started with the RA ratio + + + align:start position:0% +because we started with the RA ratio +test. We did that before we did the root + + align:start position:0% +test. We did that before we did the root + + + align:start position:0% +test. We did that before we did the root +test and you were noting that the in the + + align:start position:0% +test and you were noting that the in the + + + align:start position:0% +test and you were noting that the in the +ratio test you always comparing an + + align:start position:0% +ratio test you always comparing an + + + align:start position:0% +ratio test you always comparing an +element to the previous one, right? And + + align:start position:0% +element to the previous one, right? And + + + align:start position:0% +element to the previous one, right? And +so but in and in general, right, the + + align:start position:0% +so but in and in general, right, the + + + align:start position:0% +so but in and in general, right, the +series can be convergent even though the + + align:start position:0% +series can be convergent even though the + + + align:start position:0% +series can be convergent even though the +next element is slightly larger than the + + align:start position:0% +next element is slightly larger than the + + + align:start position:0% +next element is slightly larger than the +previous. If that keep happening, it's + + align:start position:0% +previous. If that keep happening, it's + + + align:start position:0% +previous. If that keep happening, it's +not convergent. But it could happen a + + align:start position:0% +not convergent. But it could happen a + + + align:start position:0% +not convergent. But it could happen a +few times and then it go really down, + + align:start position:0% +few times and then it go really down, + + + align:start position:0% +few times and then it go really down, +right? And that's fine, right? And so + + align:start position:0% +right? And that's fine, right? And so + + + align:start position:0% +right? And that's fine, right? And so +that's why like the the the the + + align:start position:0% +that's why like the the the the + + + align:start position:0% +that's why like the the the the +root test, right, gives you this general + + align:start position:0% +root test, right, gives you this general + + + align:start position:0% +root test, right, gives you this general +result about that is always right. It + + align:start position:0% +result about that is always right. It + + + align:start position:0% +result about that is always right. It +always work. It doesn't assume that a + + align:start position:0% +always work. It doesn't assume that a + + + align:start position:0% +always work. It doesn't assume that a +end not zero etc. right in any part for + + align:start position:0% +end not zero etc. right in any part for + + + align:start position:0% +end not zero etc. right in any part for +any particular and and it really should + + align:start position:0% +any particular and and it really should + + + align:start position:0% +any particular and and it really should +be in suk right and then it's like + + align:start position:0% +be in suk right and then it's like + + + align:start position:0% +be in suk right and then it's like +defined it's also you know it's a number + + align:start position:0% +defined it's also you know it's a number + + + align:start position:0% +defined it's also you know it's a number +that's always defined + + align:start position:0% +that's always defined + + + align:start position:0% +that's always defined +um and it it's and again you know the + + align:start position:0% +um and it it's and again you know the + + + align:start position:0% +um and it it's and again you know the +way it's stated here the way the proof + + align:start position:0% +way it's stated here the way the proof + + + align:start position:0% +way it's stated here the way the proof +goes is it's not comparing two uh + + align:start position:0% +goes is it's not comparing two uh + + + align:start position:0% +goes is it's not comparing two uh +consecutive a + + align:start position:0% +consecutive a + + + align:start position:0% +consecutive a +um in any particular example the root + + align:start position:0% +um in any particular example the root + + + align:start position:0% +um in any particular example the root +test may not be the easiest way to + + align:start position:0% +test may not be the easiest way to + + + align:start position:0% +test may not be the easiest way to +argue. Often if you can for a power + + align:start position:0% +argue. Often if you can for a power + + + align:start position:0% +argue. Often if you can for a power +sense + + align:start position:0% +sense + + + align:start position:0% +sense +almost always I would say if if it + + align:start position:0% +almost always I would say if if it + + + align:start position:0% +almost always I would say if if it +almost in a power sense it's almost + + align:start position:0% +almost in a power sense it's almost + + + align:start position:0% +almost in a power sense it's almost +always easier to use the ratio test but + + align:start position:0% +always easier to use the ratio test but + + + align:start position:0% +always easier to use the ratio test but +it require that power shares has some + + align:start position:0% +it require that power shares has some + + + align:start position:0% +it require that power shares has some +nice property for this to apply. + + align:start position:0% +nice property for this to apply. + + + align:start position:0% +nice property for this to apply. +>> Yeah. So the reason you know that r is + + align:start position:0% +>> Yeah. So the reason you know that r is + + + align:start position:0% +>> Yeah. So the reason you know that r is +infinity for that example because you + + align:start position:0% +infinity for that example because you + + + align:start position:0% +infinity for that example because you +know for all x + + align:start position:0% +know for all x + + + align:start position:0% +know for all x +>> so in this example here + + align:start position:0% +>> so in this example here + + + align:start position:0% +>> so in this example here +yeah this guy is infinity which means + + align:start position:0% +yeah this guy is infinity which means + + + align:start position:0% +yeah this guy is infinity which means +that this thing here would be zero yeah + + align:start position:0% +that this thing here would be zero yeah + + + align:start position:0% +that this thing here would be zero yeah +>> but you like you know it's very + + align:start position:0% +>> but you like you know it's very + + + align:start position:0% +>> but you like you know it's very +>> but I didn't actually calculate you see + + align:start position:0% +>> but I didn't actually calculate you see + + + align:start position:0% +>> but I didn't actually calculate you see +I didn't calculate the end booth in this + + align:start position:0% +I didn't calculate the end booth in this + + + align:start position:0% +I didn't calculate the end booth in this +example but if I had calculated I would + + align:start position:0% +example but if I had calculated I would + + + align:start position:0% +example but if I had calculated I would +actually it's not very hard to calculate + + align:start position:0% +actually it's not very hard to calculate + + + align:start position:0% +actually it's not very hard to calculate +but it needs some small tricks and So + + align:start position:0% +but it needs some small tricks and So + + + align:start position:0% +but it needs some small tricks and So +and we have yeah which we haven't talked + + align:start position:0% +and we have yeah which we haven't talked + + + align:start position:0% +and we have yeah which we haven't talked +about + + align:start position:0% +about + + + align:start position:0% +about +but so that's why like + + align:start position:0% +but so that's why like + + + align:start position:0% +but so that's why like +let me talk about a few other things and + + align:start position:0% +let me talk about a few other things and + + + align:start position:0% +let me talk about a few other things and +then I mean so again I mean you you know + + align:start position:0% +then I mean so again I mean you you know + + + align:start position:0% +then I mean so again I mean you you know +I I didn't necess I don't think I can + + align:start position:0% +I I didn't necess I don't think I can + + + align:start position:0% +I I didn't necess I don't think I can +probably review all what I what I hadn't + + align:start position:0% +probably review all what I what I hadn't + + + align:start position:0% +probably review all what I what I hadn't +my review notes but let me just talk + + align:start position:0% +my review notes but let me just talk + + + align:start position:0% +my review notes but let me just talk +about a few of the problems that I had + + align:start position:0% +about a few of the problems that I had + + + align:start position:0% +about a few of the problems that I had +but again + + align:start position:0% +but again + + + align:start position:0% +but again +so the things I Let me just quickly + + align:start position:0% +so the things I Let me just quickly + + + align:start position:0% +so the things I Let me just quickly +mention the things I I I may or may not + + align:start position:0% +mention the things I I I may or may not + + + align:start position:0% +mention the things I I I may or may not +get to that I have in my review notes. + + align:start position:0% +get to that I have in my review notes. + + + align:start position:0% +get to that I have in my review notes. +So I had also + + align:start position:0% +So I had also + + + align:start position:0% +So I had also +poverty you know what is le what is le + + align:start position:0% +poverty you know what is le what is le + + + align:start position:0% +poverty you know what is le what is le +and so definitely review that also talk + + align:start position:0% +and so definitely review that also talk + + + align:start position:0% +and so definitely review that also talk +about the radius convergence + + align:start position:0% +about the radius convergence + + + align:start position:0% +about the radius convergence +um and maybe this is all and then talk a + + align:start position:0% +um and maybe this is all and then talk a + + + align:start position:0% +um and maybe this is all and then talk a +little bit about the power series for + + align:start position:0% +little bit about the power series for + + + align:start position:0% +little bit about the power series for +the exponential functions but again all + + align:start position:0% +the exponential functions but again all + + + align:start position:0% +the exponential functions but again all +the stuff we did on the power series for + + align:start position:0% +the stuff we did on the power series for + + + align:start position:0% +the stuff we did on the power series for +the exponential functions + + align:start position:0% +the exponential functions + + + align:start position:0% +the exponential functions +And you know at this point we have + + align:start position:0% +And you know at this point we have + + + align:start position:0% +And you know at this point we have +established it. This is like um it's + + align:start position:0% +established it. This is like um it's + + + align:start position:0% +established it. This is like um it's +more like uh I mean there won't be + + align:start position:0% +more like uh I mean there won't be + + + align:start position:0% +more like uh I mean there won't be +anything particular about I mean the + + align:start position:0% +anything particular about I mean the + + + align:start position:0% +anything particular about I mean the +exponential function itself could be on + + align:start position:0% +exponential function itself could be on + + + align:start position:0% +exponential function itself could be on +the uh midterm but it's not like you + + align:start position:0% +the uh midterm but it's not like you + + + align:start position:0% +the uh midterm but it's not like you +would have to prove the properties of + + align:start position:0% +would have to prove the properties of + + + align:start position:0% +would have to prove the properties of +the exponential function. This property + + align:start position:0% +the exponential function. This property + + + align:start position:0% +the exponential function. This property +that it has property that the + + align:start position:0% +that it has property that the + + + align:start position:0% +that it has property that the +exponential function of x + y is like + + align:start position:0% +exponential function of x + y is like + + + align:start position:0% +exponential function of x + y is like +the product of that kind of stuff. It's + + align:start position:0% +the product of that kind of stuff. It's + + + align:start position:0% +the product of that kind of stuff. It's +not on the midterm. Okay. So, I didn't + + align:start position:0% +not on the midterm. Okay. So, I didn't + + + align:start position:0% +not on the midterm. Okay. So, I didn't +so it's not part of this review. + + align:start position:0% +so it's not part of this review. + + + align:start position:0% +so it's not part of this review. +The other thing that I probably won't + + align:start position:0% +The other thing that I probably won't + + + align:start position:0% +The other thing that I probably won't +get to because I in a minute I'll just + + align:start position:0% +get to because I in a minute I'll just + + + align:start position:0% +get to because I in a minute I'll just +turn to these other problems is that + + align:start position:0% +turn to these other problems is that + + + align:start position:0% +turn to these other problems is that +metric spaces definitely review metric + + align:start position:0% +metric spaces definitely review metric + + + align:start position:0% +metric spaces definitely review metric +spaces. Uh it was in the last lecture. + + align:start position:0% +spaces. Uh it was in the last lecture. + + + align:start position:0% +spaces. Uh it was in the last lecture. +So, you know there's a bunch of you know + + align:start position:0% +So, you know there's a bunch of you know + + + align:start position:0% +So, you know there's a bunch of you know +like there's three properties for metric + + align:start position:0% +like there's three properties for metric + + + align:start position:0% +like there's three properties for metric +space. The distance should be non- + + align:start position:0% +space. The distance should be non- + + + align:start position:0% +space. The distance should be non- +negative. It should be symmetric and the + + align:start position:0% +negative. It should be symmetric and the + + + align:start position:0% +negative. It should be symmetric and the +distance between two points should be + + align:start position:0% +distance between two points should be + + + align:start position:0% +distance between two points should be +zero if and only if those point are the + + align:start position:0% +zero if and only if those point are the + + + align:start position:0% +zero if and only if those point are the +same. And then the crucial the crucial + + align:start position:0% +same. And then the crucial the crucial + + + align:start position:0% +same. And then the crucial the crucial +property in the metric space and that's + + align:start position:0% +property in the metric space and that's + + + align:start position:0% +property in the metric space and that's +like the powerful property is the + + align:start position:0% +like the powerful property is the + + + align:start position:0% +like the powerful property is the +triangle. + + align:start position:0% +triangle. + + + align:start position:0% +triangle. +Okay. And so there was a few examples + + align:start position:0% +Okay. And so there was a few examples + + + align:start position:0% +Okay. And so there was a few examples +and review those examples. I I there in + + align:start position:0% +and review those examples. I I there in + + + align:start position:0% +and review those examples. I I there in +my review notes like the most important + + align:start position:0% +my review notes like the most important + + + align:start position:0% +my review notes like the most important +example I would say this the French + + align:start position:0% +example I would say this the French + + + align:start position:0% +example I would say this the French +world metric is kind of uh you know + + align:start position:0% +world metric is kind of uh you know + + + align:start position:0% +world metric is kind of uh you know +crazy uh metric that's not one of the + + align:start position:0% +crazy uh metric that's not one of the + + + align:start position:0% +crazy uh metric that's not one of the +important ones so I just in just the + + align:start position:0% +important ones so I just in just the + + + align:start position:0% +important ones so I just in just the +most important ones and then there's + + align:start position:0% +most important ones and then there's + + + align:start position:0% +most important ones and then there's +this with what does it mean to be + + align:start position:0% +this with what does it mean to be + + + align:start position:0% +this with what does it mean to be +convergent in a metric space and what + + align:start position:0% +convergent in a metric space and what + + + align:start position:0% +convergent in a metric space and what +does it mean to be a C sequence + + align:start position:0% +does it mean to be a C sequence + + + align:start position:0% +does it mean to be a C sequence +and so now let's get to a couple of the + + align:start position:0% +and so now let's get to a couple of the + + + align:start position:0% +and so now let's get to a couple of the +other uh problems that I suggested that + + align:start position:0% +other uh problems that I suggested that + + + align:start position:0% +other uh problems that I suggested that +you look at + + align:start position:0% +you look at + + + align:start position:0% +you look at +u and so + + align:start position:0% +u and so + + + align:start position:0% +u and so +so here are two other problems + + align:start position:0% +so here are two other problems + + + align:start position:0% +so here are two other problems +u and again you know I won't get to + + align:start position:0% +u and again you know I won't get to + + + align:start position:0% +u and again you know I won't get to +there's also problems about message + + align:start position:0% +there's also problems about message + + + align:start position:0% +there's also problems about message +bases and you should definitely look at + + align:start position:0% +bases and you should definitely look at + + + align:start position:0% +bases and you should definitely look at +it but I I don't have the time + + align:start position:0% +it but I I don't have the time + + + align:start position:0% +it but I I don't have the time +even though it's relevant for the mum uh + + align:start position:0% +even though it's relevant for the mum uh + + + align:start position:0% +even though it's relevant for the mum uh +I just have to pick some + + align:start position:0% + + + + align:start position:0% + +all of all of the problems that I I I + + align:start position:0% +all of all of the problems that I I I + + + align:start position:0% +all of all of the problems that I I I +have four problems here. All of these + + align:start position:0% +have four problems here. All of these + + + align:start position:0% +have four problems here. All of these +are + + align:start position:0% +are + + + align:start position:0% +are +okay. So now uh suppose you take suppose + + align:start position:0% +okay. So now uh suppose you take suppose + + + align:start position:0% +okay. So now uh suppose you take suppose +you take a sequence. So I have a + + align:start position:0% +you take a sequence. So I have a + + + align:start position:0% +you take a sequence. So I have a +sequence here xn and so often a sequence + + align:start position:0% +sequence here xn and so often a sequence + + + align:start position:0% +sequence here xn and so often a sequence +is defined recursively. + + align:start position:0% +is defined recursively. + + + align:start position:0% +is defined recursively. +So recursive + + align:start position:0% + + + + align:start position:0% + +so recursively defined + + align:start position:0% +so recursively defined + + + align:start position:0% +so recursively defined +sequences. + + align:start position:0% +sequences. + + + align:start position:0% +sequences. +So what does it mean? It means that + + align:start position:0% +So what does it mean? It means that + + + align:start position:0% +So what does it mean? It means that +typically you have the first one is + + align:start position:0% +typically you have the first one is + + + align:start position:0% +typically you have the first one is +defined to be whatever and then the next + + align:start position:0% +defined to be whatever and then the next + + + align:start position:0% +defined to be whatever and then the next +one is defined from the previous one. + + align:start position:0% +one is defined from the previous one. + + + align:start position:0% +one is defined from the previous one. +And so the one I was suggesting + + align:start position:0% +And so the one I was suggesting + + + align:start position:0% +And so the one I was suggesting +looking at here is that you said this + + align:start position:0% +looking at here is that you said this + + + align:start position:0% +looking at here is that you said this +here the first one. + + align:start position:0% +here the first one. + + + align:start position:0% +here the first one. +Um + + align:start position:0% + + + + align:start position:0% + +right and then actually let me let me + + align:start position:0% +right and then actually let me let me + + + align:start position:0% +right and then actually let me let me +and then the next one let me just do + + align:start position:0% +and then the next one let me just do + + + align:start position:0% +and then the next one let me just do +this one here. It's actually simpler + + align:start position:0% +this one here. It's actually simpler + + + align:start position:0% +this one here. It's actually simpler +than what I have in my notes, but maybe + + align:start position:0% +than what I have in my notes, but maybe + + + align:start position:0% +than what I have in my notes, but maybe +that one. But but I just want to So the + + align:start position:0% +that one. But but I just want to So the + + + align:start position:0% +that one. But but I just want to So the +next one is defined to be xn. + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +And so then uh right. So now uh the + + align:start position:0% +And so then uh right. So now uh the + + + align:start position:0% +And so then uh right. So now uh the +question will be uh for what + + align:start position:0% +question will be uh for what + + + align:start position:0% +question will be uh for what +for what + + align:start position:0% +for what + + + align:start position:0% +for what +a does this + + align:start position:0% + + + + align:start position:0% + +have a limit the sequence + + align:start position:0% + + + + align:start position:0% + +have a limit + + align:start position:0% +have a limit + + + align:start position:0% +have a limit +and so you see that in this case we only + + align:start position:0% +and so you see that in this case we only + + + align:start position:0% +and so you see that in this case we only +have four minutes left so I only say few + + align:start position:0% +have four minutes left so I only say few + + + align:start position:0% +have four minutes left so I only say few +but this is also it just you do I just + + align:start position:0% +but this is also it just you do I just + + + align:start position:0% +but this is also it just you do I just +wanted you to review what it means like + + align:start position:0% +wanted you to review what it means like + + + align:start position:0% +wanted you to review what it means like +for a sequence to be defined recursively + + align:start position:0% +for a sequence to be defined recursively + + + align:start position:0% +for a sequence to be defined recursively +okay and so you see that in this is + + align:start position:0% +okay and so you see that in this is + + + align:start position:0% +okay and so you see that in this is +right. You have you have that this thing + + align:start position:0% +right. You have you have that this thing + + + align:start position:0% +right. You have you have that this thing +here. It is going down. It's actually + + align:start position:0% +here. It is going down. It's actually + + + align:start position:0% +here. It is going down. It's actually +going down. It it even could go down by + + align:start position:0% +going down. It it even could go down by + + + align:start position:0% +going down. It it even could go down by +a fraction. But now it's like if you're + + align:start position:0% +a fraction. But now it's like if you're + + + align:start position:0% +a fraction. But now it's like if you're +looking at this thing here, if you're + + align:start position:0% +looking at this thing here, if you're + + + align:start position:0% +looking at this thing here, if you're +looking at XN, this here is definitely + + align:start position:0% +looking at XN, this here is definitely + + + align:start position:0% +looking at XN, this here is definitely +going to converge. Whatever you start + + align:start position:0% +going to converge. Whatever you start + + + align:start position:0% +going to converge. Whatever you start +with. + + align:start position:0% +with. + + + align:start position:0% +with. +So I claim that you will always get + + align:start position:0% +So I claim that you will always get + + + align:start position:0% +So I claim that you will always get +that you will always get that xn here + + align:start position:0% +that you will always get that xn here + + + align:start position:0% +that you will always get that xn here +converted to zero + + align:start position:0% +converted to zero + + + align:start position:0% +converted to zero +and it's just you see that if you when + + align:start position:0% +and it's just you see that if you when + + + align:start position:0% +and it's just you see that if you when +you have something recursively + + align:start position:0% +you have something recursively + + + align:start position:0% +you have something recursively +it's often can pay to just write out the + + align:start position:0% +it's often can pay to just write out the + + + align:start position:0% +it's often can pay to just write out the +few first few terms. So you have x and a + + align:start position:0% +few first few terms. So you have x and a + + + align:start position:0% +few first few terms. So you have x and a +x2 is equal to uh a over uh y a is also + + align:start position:0% +x2 is equal to uh a over uh y a is also + + + align:start position:0% +x2 is equal to uh a over uh y a is also +a right because it's the previous one. H + + align:start position:0% +a right because it's the previous one. H + + + align:start position:0% +a right because it's the previous one. H +x2 + + align:start position:0% +x2 + + + align:start position:0% +x2 +is now uh a / 2 x4 + + align:start position:0% +is now uh a / 2 x4 + + + align:start position:0% +is now uh a / 2 x4 +is then uh a / 2 / 3. So this is a / 6, + + align:start position:0% +is then uh a / 2 / 3. So this is a / 6, + + + align:start position:0% +is then uh a / 2 / 3. So this is a / 6, +right? and so on, right? And so if you + + align:start position:0% +right? and so on, right? And so if you + + + align:start position:0% +right? and so on, right? And so if you +continue like this, you will see that + + align:start position:0% +continue like this, you will see that + + + align:start position:0% +continue like this, you will see that +they get that it's like a divided by + + align:start position:0% +they get that it's like a divided by + + + align:start position:0% +they get that it's like a divided by +some larger and larger number, right? + + align:start position:0% +some larger and larger number, right? + + + align:start position:0% +some larger and larger number, right? +And but you have to of course write it + + align:start position:0% +And but you have to of course write it + + + align:start position:0% +And but you have to of course write it +nicely out as a proof, right? But this + + align:start position:0% +nicely out as a proof, right? But this + + + align:start position:0% +nicely out as a proof, right? But this +is so this is proving that. But again, + + align:start position:0% +is so this is proving that. But again, + + + align:start position:0% +is so this is proving that. But again, +you know, this here, if you just did + + align:start position:0% +you know, this here, if you just did + + + align:start position:0% +you know, this here, if you just did +what I did, that would not be enough to + + align:start position:0% +what I did, that would not be enough to + + + align:start position:0% +what I did, that would not be enough to +get full credit, right? So definitely + + align:start position:0% +get full credit, right? So definitely + + + align:start position:0% +get full credit, right? So definitely +write out the other thing in the last + + align:start position:0% +write out the other thing in the last + + + align:start position:0% +write out the other thing in the last +minute here. The other thing uh + + align:start position:0% +minute here. The other thing uh + + + align:start position:0% +minute here. The other thing uh +uh the other + + align:start position:0% +uh the other + + + align:start position:0% +uh the other +thing here for my example here we look + + align:start position:0% +thing here for my example here we look + + + align:start position:0% +thing here for my example here we look +suppose you take a series like this and + + align:start position:0% +suppose you take a series like this and + + + align:start position:0% +suppose you take a series like this and +suppose that a yeah here was less than 1 + + align:start position:0% +suppose that a yeah here was less than 1 + + + align:start position:0% +suppose that a yeah here was less than 1 +/ n² + + align:start position:0% +/ n² + + + align:start position:0% +/ n² +and then the question could be is this + + align:start position:0% +and then the question could be is this + + + align:start position:0% +and then the question could be is this +series + + align:start position:0% +series + + + align:start position:0% +series +is the series because you knew this but + + align:start position:0% +is the series because you knew this but + + + align:start position:0% +is the series because you knew this but +that's all you know is the is + + align:start position:0% + + + + align:start position:0% + +convergent or divergent + + align:start position:0% +convergent or divergent + + + align:start position:0% +convergent or divergent +or divergent, + + align:start position:0% + + + + align:start position:0% + +right? And and and and then I say in the + + align:start position:0% +right? And and and and then I say in the + + + align:start position:0% +right? And and and and then I say in the +notes here, I mean in the in the review + + align:start position:0% +notes here, I mean in the in the review + + + align:start position:0% +notes here, I mean in the in the review +here, right? that if either you should + + align:start position:0% +here, right? that if either you should + + + align:start position:0% +here, right? that if either you should +prove that for all such series it's + + align:start position:0% +prove that for all such series it's + + + align:start position:0% +prove that for all such series it's +convergent or if that's not the case you + + align:start position:0% +convergent or if that's not the case you + + + align:start position:0% +convergent or if that's not the case you +should give an example of a series with + + align:start position:0% +should give an example of a series with + + + align:start position:0% +should give an example of a series with +this property that is divergent because + + align:start position:0% +this property that is divergent because + + + align:start position:0% +this property that is divergent because +obviously if all the a was zero it would + + align:start position:0% +obviously if all the a was zero it would + + + align:start position:0% +obviously if all the a was zero it would +be convergence right but it still could + + align:start position:0% +be convergence right but it still could + + + align:start position:0% +be convergence right but it still could +be another series with a end that + + align:start position:0% +be another series with a end that + + + align:start position:0% +be another series with a end that +property that was divergent right but in + + align:start position:0% +property that was divergent right but in + + + align:start position:0% +property that was divergent right but in +this case it is going to be convergence. + + align:start position:0% +this case it is going to be convergence. + + + align:start position:0% +this case it is going to be convergence. +And why is it convergent? Because that + + align:start position:0% +And why is it convergent? Because that + + + align:start position:0% +And why is it convergent? Because that +this series here is convergence, right? + + align:start position:0% +this series here is convergence, right? + + + align:start position:0% +this series here is convergence, right? +But we've already seen. So this here + + align:start position:0% +But we've already seen. So this here + + + align:start position:0% +But we've already seen. So this here +would be like the simple comparison test + + align:start position:0% +would be like the simple comparison test + + + align:start position:0% +would be like the simple comparison test +like the first comparison test. + + align:start position:0% +like the first comparison test. + + + align:start position:0% +like the first comparison test. +Okay. So + + align:start position:0% + + + + align:start position:0% + +um right. So these are just like + + align:start position:0% +um right. So these are just like + + + align:start position:0% +um right. So these are just like +examples of things you should be + + align:start position:0% +examples of things you should be + + + align:start position:0% +examples of things you should be +reviewing. Right? They are this like + + align:start position:0% +reviewing. Right? They are this like + + + align:start position:0% +reviewing. Right? They are this like +these sinks here, the two sinks to the + + align:start position:0% +these sinks here, the two sinks to the + + + align:start position:0% +these sinks here, the two sinks to the +end that like this one here like this is + + align:start position:0% +end that like this one here like this is + + + align:start position:0% +end that like this one here like this is +super fast. So don't expect it to be + + align:start position:0% +super fast. So don't expect it to be + + + align:start position:0% +super fast. So don't expect it to be +quite as fast on the m but it just give + + align:start position:0% +quite as fast on the m but it just give + + + align:start position:0% +quite as fast on the m but it just give +you it just give you an idea of what you + + align:start position:0% +you it just give you an idea of what you + + + align:start position:0% +you it just give you an idea of what you +should be doing. Okay. \ No newline at end of file diff --git a/rei6tud0Tsg.txt b/rei6tud0Tsg.txt new file mode 100644 index 0000000000000000000000000000000000000000..b43ccde0121badedc82517ac81db8c5dcab6d035 --- /dev/null +++ b/rei6tud0Tsg.txt @@ -0,0 +1,3757 @@ +NARRATOR: The following content +is provided under a + +Creative Commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high-quality educational +resources for free. + +To make a donation or to view +additional materials from + +hundreds of MIT courses, visit +MIT OpenCourseWare at + +ocw.mit.edu. + +PROFESSOR: To take up the topic +of quantization, you + +remember we're talking about +source coding in the first + +part of the course, channel +coding in the + +last 2/3 of the course. + +Source coding, like all, is +divided into three parts. + +If you have waveforms, such +as speech, you start + +out with the waveform. + +The typical way to encode +waveforms is you first either + +sample the waveform or +you expand it in + +some kind of expansion. + +When you do that, you wind up +with a sequence of numbers. + +You put the sequence of numbers +into a quantizer, and + +the quantizer reduces that +to a discrete alphabet. + +You put the discrete symbols +into the discrete encoder. + +You pass it through a reliable +binary channel. + +What is a reliable +binary channel? + +It's a layered view of any old +channel in the world, OK? + +In other words, the way that +discrete channels work these + +days is that, in almost all +cases, what goes into them is + +a binary stream of signals, and +what comes out of them is + +a binary stream of symbols, and +the output is essentially + +the same z-input. + +That's the whole purpose of +how you design digital + +channels, and they work +over analog media and + +all sorts of things. + +OK, so discrete encoders and +discrete decoders are really a + +valid topic to study +in their own. + +I mean, you have text and stuff +like that, which is + +discrete to start with, so +there's a general topic of how + +do you encode discrete things? + +We've pretty much answered that +problem, at least in an + +abstract sense, and the main +point there is you find the + +entropy of that discrete +sequence, the entropy per + +symbol, and then you find ways +of encoding that discrete + +source in such a way that the +number of bits per symbol is + +approximately equal +to that entropy. + +We know you can't do any +better than that. + +You can't do an encoding, which +is uniquely decodable, + +which you can get out of with +the original symbols again, + +with anything less +than the entropy. + +So at least we know roughly what +the answer to that is. + +We even know some classy schemes +like the Lempel-Ziv + +algorithm, which will in fact +operate without even knowing + +anything about what the +probabilities are. + +So we sort of understand this +block here at this point. + +And we could start with this +next, or we could start with + +this next, and unlike the +electrician here, we're going + +to move in sequence and look at +this next and this third. + +There's another reason +for that. + +When we get into this question, +we will be talking + +about what do you do +with waveforms? + +How do you deal with +waveforms? + +It's what you've been studying +probably since the sixth + +grade, and you're all +familiar with it. + +You do integration and +things like that. + +You know how to work +with functions. + +What we're going to do with +functions in this course is a + +little bit different than +what you're used to. + +It's quite a bit different than +what you learned in your + +Signals and Systems course, and +you'll find out why as we + +move along. + +But we have to understand this +business of how to deal with + +waveforms, both in terms of this +block, which is the final + +block we'll study in source +coding, and also in terms of + +how to deal with channels +because in real channels, + +generally what you transmit +is a waveform. + +What the noise does to you is to +add a waveform or, in some + +sense, multiply what you put +in by something else. + +And all of that is +waveform stuff. + +And all of information theory +and all of digital + +communication is based +on thinking bits. + +So somehow or other, we have to +become very facile in going + +from waveforms to bits. + +Now I've been around the +professional communities of + +both communication and +information theory for + +a long, long time. + +There is one fundamental problem +that gives everyone + +problems because information +theory texts do not deal with + +it and communication texts +do not deal with it. + +And that problem is how do you +go from one to the other, + +which seems like it ought +to be an easy thing. + +It's not as easy as it looks, +and therefore, we're going to + +spent quite a bit +of time on that. + +In fact, I passed out lectures +6 and 7 today, which in + +previous years I've done in two +separate lectures because + +quantization is a problem +that looks important. + +We'll see that it's not quite +as important as it looks. + +And I guess the other thing is, +I mean, at different times + +you have to teach different +things or you get stale on it. + +And I've just finished writing +some fairly nice notes, I + +think, on this question of how +do you go from waveforms to + +numbers and how do you go from +numbers to waveforms. + +And I want to spend a little +more time on that this year + +than I did last year. + +I want to spend, therefore, +a little less time on + +quantization, so that next time, +we will briefly review + +what we've done today on +quantization, but we will + +essentially just compress +those two + +lectures all into one. + +In dealing with waveforms, +we're going to learn some + +interesting and kind +of cool things. + +Like for those of you who +really don't -- are not + +interested in mathematics, you +know that people study things + +like the theory of real +variables and functional + +analysis and all of these neat +things, which are very, in a + +sense, advanced mathematics. + +They're all based on measure +theory, and you're going to + +find out a little bit about +measure theory here. + +Not an awful lot, but just +enough to know why one has to + +deal with those questions +because the major results in + +dealing with waveforms and +samples really can't be stated + +in any other form than +in a somewhat + +measure-theoretic form. + +So we're going to find just +enough about that so we can + +understand what those +issues are about. + +So that's why next time we're +going to start dealing with + +the waveform issues. + +OK, so today, we're dealing with +these quantizer issues + +and how do you take a sequence +of numbers, turn them into a + +sequence of symbols +at the other end? + +How do you take a sequence +of symbols, turn + +them back into numbers? + +So when you convert real numbers +to binary strings, you + +need a mapping from the +set of real numbers + +to a discrete alphabet. + +And we're typically going to +have a mapping from the set of + +real numbers into a finite +discrete alphabet. + +Now what's the first obvious +thing that you notice when you + +have a mapping that goes from an +infinite set of things into + +a finite set of things? + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: What? + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: Not really. + +It's a much simpler +idea than that. + +How are you going to get back? + +I mean, usually when you map +something into something else, + +you would like to +get back again. + +When you map an infinite set +into a finite set, how are you + +going to get back? + +AUDIENCE: You're not. + +PROFESSOR: You're not. + +Good! + +There's not any way in hell +that you're ever going + +to get back, OK? + +So, in other words, what +you've done here is to + +deliberately introduce some +distortion into the picture. + +You've introduced distortion +because you have no choice. + +If you want to turn numbers into +bits, you can't get back + +to the exact numbers again. + +So you can only get back to some +approximation of what the + +numbers are. + +But anyway, this process of +doing this is called scalar + +quantization, if we're mapping +from the set of real numbers + +to a discrete alphabet. + +If instead you want to convert +real n-tuples into sequences + +of discrete symbols, in other +words, into a finite alphabet, + +you call that vector +quantization because you can + +view n real numbers, a sequence +of n real numbers as + +a vector within coordinates +and within components. + +And I'm not doing anything +fancy with vectors here. + +You just look at an n-tuple +of numbers as a vector. + +OK, so scalar quantization is +going to encode each term of + +the source sequence +separately. + +And vector quantization is first +going to segment this + +sequence of numbers into blocks +of n numbers each, and + +then it's going to find a way +of encoding those n-blocks + +into discrete symbols. + +Does this sound a little bit +like what we've already done + +in dealing with discrete +sources? + +Yeah, it's exactly +the same thing. + +I mean, we started out by +mapping individual symbols + +into bit sequences, and then we +said, gee, we can also map + +n-blocks of those symbols into +bits, and we said, gee, this + +is the same problem again. + +There's nothing different, +nothing new. + +And it's the same thing here +almost except here the + +properties of the real numbers +are important. + +Why are the properties of the +real numbers important? + +Why can't we just look +at this as symbols? + +Well, because, since we can't +do this mapping in an + +invertable way, you have to deal +with the fact that you + +have distortion here. + +There's no other way +to think about it. + +There is distortion. + +You might as well face it. + +If you try to cover it +up, it just comes + +up to kick you later. + +So we face it right in the +beginning, and that's why we + +deal with these things +as numbers. + +So let's look at a simple +example of what a scalar + +quantizer is going to do. + +Basically, what we have to do +is to map the line R, mainly + +the set of real numbers, into +M different regions, which + +we'll call R1 up to R sub M. +And in this picture here, + +here's R1, here's R2, here's R3, +here's R4, R5 and R6, and + +that's all the regions +we have. + +You'll notice one of the things +that that does is it + +takes an enormous set of +numbers, namely all these + +numbers less than this, +and match them all + +into the same symbol. + +So you might wind up with a +fair amount of distortion + +there, no matter how you +measure distortion. + +All these outliers here all +get mapped into a6, and + +everything in the middle gets +mapped somehow into these + +intermediate values. + +But every source value now in +the region R sub j, we're + +going to map into a +representation point a sub j. + +So everything in R1 is going +to be mapped into a1. + +Everything in R2 is going +to get mapped + +into a2 and so forth. + +Is this a general way to map +R into a set of M symbols? + +Is there anything else I ought +to be thinking about? + +Well, here, these regions here +have a very special property. + +Namely, each region +is an interval. + +And we might say to ourselves, +well, maybe we shouldn't map + +points into intervals. + +But aside from the fact that +we've chosen intervals here, + +this is a perfectly general +way to represent a mapping + +from the real numbers into +a discrete set of things. + +Namely, when you're doing a +mapping from the real numbers + +into a discrete set of things, +there's some set of real + +numbers that get mapped +into a1, and that by + +definition is called R1. + +There's some set of numbers +which get mapped into a2. + +That by definition is called +R2 and so forth. + +So aside from the fact that +these intervals with these + +regions in this picture happen +to be intervals, this is a + +perfectly general mapping from +R into a discrete alphabet. + +So since I've decided I'm +going to look at scalar + +quantizers first, this is a +completely general view of + +what a scalar quantizer is. + +You tell me how many +quantization regions you want, + +namely how big the alphabet is +that you're mapping things + +into, and then your only problem +is how do you choose + +these regions and how +do you choose the + +representation points? + +OK, one new thing here: Before, +we said when you have + +a set of symbols a1 up to +a6, it doesn't matter + +what you call them. + +They're just six symbols. + +Here it makes a difference what +you call them because + +here they are representing +real numbers and they are + +representing real numbers +because when you map some real + +number on the real line into one +of these letters here, the + +distortion is u minus a sub j. + +If you're mapping u into a sub +j, then you get a distortion, + +which is this difference here. + +I haven't said yet what I am +interested in as far as + +distortion is concerned. + +Am I interested in squared +distortion, cubed distortion, + +absolute magnitude +of distortion? + +I haven't answered that +question yet. + +But there is a distortion here, +and somehow that has to + +be important. + +We have to come to grips with +what we call a distortion and + +somehow how big that distortion +is going to be. + +So our problem here is somehow +to trade off between + +distortion and number +of points. + +As we make the number of +points bigger, we can + +presumably make the distortion +smaller in some sense, + +although the distortion is +always going to be very big + +from these really big negative +numbers and from really big + +positive numbers. + +But aside from that, we just +have a problem of how do you + +choose the regions? + +How do you choose the points? + +OK, I've sort of forgotten +about the problem that we + +started with. + +And the problem that we started +with was to have a + +source where the source was +a sequence of numbers. + +And when we're talking about +sources, we're talking about + +something stochastic. + +We need a probability measure +on these real numbers that + +we're encoding. + +If we knew what they were, there +wouldn't be any need to + +encode them. + +I mean, if we knew and the +receiver knew, there would be + +no need to encode them. + +The receiver would just print +out what they were or store + +them or do whatever +the receiver + +wants to do with them. + +OK, so we're going to view the +source value u with the sample + +value of some random variable +capital U. And more generally, + +since we have a sequence, we're +going to consider a + +source sequence to be U1, U2, U3 +and so forth, or you could + +consider it a bi-infinite +sequence, starting at U minus + +infinity and working +its way up forever. + +And then we're going to have +some sort of model, + +statistical model, for this +sequence of random variables. + +Our typical model for these is +to assume that we have a + +memoryless source. + +In other words, U1, U2, U3 are +independent, identically + +distributed, random variables. + +That's the model we'll use until +we get smarter and start + +to think of something else. + +OK, so now each of these source +values we're going to + +map into some representation +point a sub j. + +That's what defines +the quantizer. + +And now since a sub j is a +sample value of a random + +variable U, a sub j is going to +be a sample value of some + +random variable V. OK, in other +words, the probabilities + +of these different sample +values is going to be + +determined by the set of U's +that math into that a sub j. + +So we have a source sequence +U1, U2, blah, blah, blah. + +We have a representation +sequence V1, V2, blah, blah, + +blah, which is defined by if U +sub k is in R sub j, then Vk + +is equal to a sub j. + +Point of confusion here: It's +not confusing now, but it will + +be confusing at some +point to you. + +When you're talking about +sources, you really need two + +indices that you're talking +about all the time. + +OK, one of them is +how to represent + +different elements in time. + +Here we're using k as a way of +keeping track of what element + +in time we're talking about. + +We're also talking about a +discrete alphabet, which has a + +certain number of elements in +it, which is completely + +independent of time. + +Namely, we've just described +the quantizer as something + +which maps real numbers +into sample values. + +It has nothing to do +with time at all. + +We're going to use that same +thing again and again and + +again, and we're using +the subscript j + +to talk about that. + +When you write out problem +solutions, you are going to + +find that it's incredibly +difficult sometimes to write + +sentences which distinguish +about whether you're talking + +about one element out of an +alphabet or one element out of + +a time sequence. + +And everybody has that trouble, +and you read most of + +the literature in information +theory or communication + +theory, and you can't sort out +most of the time what people + +are talking about because +they're doing that. + +I recommend to you using an +element and an alphabet to + +talk about this sort of thing, +what a sub j is or an element + +and a time sequence to +keep track of things + +at different times. + +It's a nice way of keeping +them straight. + +OK, so anyway, for a scalar +quantizer, we're going to be + +able to just look at a single +random variable U, which is a + +continuous-valued random +variable, which takes values + +anywhere on the real line and +maps it into a single element + +in this discrete alphabet, which +is the set a1 up to a6 + +that we were talking +about here. + +So a scalar quantizer then is +just a map of this form, OK? + +So the only thing we need for a +scalar quantizer, we can now + +forget about time and talk about +how do you choose the + +regions, how do you choose the +representation points? + +OK, and there's a nice +algorithm there. + +Again, one of these things, +which if you were the first + +person to think about it, easy +way to become famous. + +You might not stay famous, but +you can get famous initially. + +Anyway, we're almost always +interested in the mean squared + +error or the mean squared +distortion, MSD or MSE, which + +is the expected value of U minus +V. U is this real-valued + +random variable. + +V is the discrete random +variable into which it maps. + +We have the distortion between +U and V, which is U minus V. + +We now have the expected value +of that squared distortion. + +Why is everybody interested in +squared distortion instead of + +magnitude distortion +or something else? + +In many engineering problems, +you should be more interested + +in magnitude distortion. + +Sometimes you're much more +interested in fourth-moment + +distortion or some other +strange thing. + +Why do we always use mean +squared distortion? + +And why do we use mean-squared +everything throughout almost + +everything we do in +communication? + +I'll tell you the reason now. + +We'll come back and talk about +it more a number of times. + +It's because this quantization +problem that we're talking + +about is almost always a +subproblem of this problem, + +where you're dealing with +waveforms, where you take the + +waveform and you sample the +waveform, where you take the + +waveform, and you turn the +waveform into some expansion. + +When you find the mean-squared +distortion in a quantizer, it + +turns out that that maps in +a beautiful way into the + +mean-squared distortion +between waveforms. + +If you deal with magnitudes or +with anything else in the + +world, all of that beauty +goes away, OK? + +In other words, whenever you +want to go from waveforms to + +numbers, the one thing which +remains invariant, which + +remains nice all the way +through, is this mean-square + +distortion, mean-square +value, OK? + +In other words, if you want +to layer this problem into + +looking at this problem +separately from looking at + +this problem, almost the only +way you can do it that makes + +sense is to worry about mean +square distortion rather than + +some other kind of distortion. + +So even though as engineers +we might be interested in + +something else, we almost always +stick to that because + +that's the thing that we can +deal with most nicely. + +I mean, as engineers, we're like +the drunk who dropped his + +wallet on a dark street, and +he's searching for it, and + +somebody comes along. + +And here he is underneath a +beautiful light where he can + +see everything. + +Somebody asks him what he's +looking for you, and he says + +he's looking for his wallet. + +The guy looks down and says, +well, there's no wallet there. + +The drunk says I know. + +I dropped it over there, but +it's dark over there. + +So we use mean square +distortion in + +exactly the same sense. + +It isn't necessarily the problem +we're interested in, + +but it's a problem where we +can see things clearly. + +So given that we're interested +in the mean square distortion + +of a scalar quantizer, an +interesting analytical problem + +that we can play with is for a +given probability density on + +this real random variable, and +we're assuming we have a + +probability density and a given +alphabet size M, the + +problem is how do you choose +these regions and how do you + +choose these representation +points in such a way as to + +minimize the mean square +error, OK? + +So, in other words, we've taken +a big sort of messy + +amorphous engineering problem, +and we said, OK, we're going + +to deal with mean square error, +and OK, we're going to + +deal with scalar quantizers, and +OK, we're going to fix a + +number of quantization levels, +so we've made all those + +choices to start with. + +We still have this interesting +problem of how do you choose + +the right regions? + +How do you choose the +right sample points? + +And that turns out to +be a simple problem. + +I wouldn't talk about +if it wasn't simple. + +And we'll break it into +subproblems, and the + +subproblems are really simple. + +The first subproblem is if I +tell you what representation + +points I want to use, namely, +in this picture here, I say + +OK, I want to use these +representation points. + +And then I ask you, how are +you going to choose the + +regions in an optimal way to +minimize mean square error? + +Well, you think about that for +awhile, and you think about it + +in a number of ways. + +When you think about it in just +the right way, the answer + +becomes obvious. + +And the answer is, let me not +think about the regions here, + +but let me think about a +particular value that comes + +out of the source. + +Let me think, how should I +construct a rule for how to + +take outputs from this +source and map them + +into some number here. + +So if I get some output from +the source u, I say, OK, + +what's the distortion +between u and a1? + +It's u minus a1. + +And the magnitude of that is the +magnitude of u minus a1. + +The square of it is the square +of u minus a1, and then say, + +OK, let me compare that +with u minus a2. + +Let me compare it with u +minus a3 and so forth. + +Let me choose the smallest +of those things. + +What's the smallest stuff +for any given u? + +Suppose I have a u which +happens to be + +right there, for example. + +What's the closest +representation point? + +Well, a3 is obviously +closer than a2. + +And in fact for any point in +here, which is closer to a3 + +than it is to a2, we're +going to choose a3. + +Now what's the set of points +which are closer to a3 than + +they are to a2? + +Well, you put a line here right +between a2 and a3, OK? + +When you put that line right +between a2 and a3, everything + +on this side is closer to a3 and +everything on this side is + +closer to a2. + +So the answer is, +in fact, simple, + +once you see the answer. + +And the answer is, given these +points, we simply construct + +bisectors between them, namely, +bisectors with -- + +halfway between a1 and +a2, we call that b1. + +Halfway between a2 and a3, we +call that b2, and those are + +the separators between +the regions, OK? + +In other words, what we wind +up doing is we define the + +region R sub j, the set of +things which get mapped into a + +sub j as the region which is +bounded by bj minus 1 is the + +average of aj and aj minus 1, +and bj is the average of aj + +and aj plus 1, where I've +already ordered the points a + +sub j going from left +to right, OK? + +And that also tells us that the +minimum mean square error + +regions have got to +be intervals. + +There is no reason at all to +ever pick regions which are + +not intervals because, as soon +as you start to solve this + +problem for any given set of +representation points, you + +wind up with intervals. + +So if you ever think of using +things that are not intervals + +for this mean square error +problem, then as soon as you + +look at this, you say, well, +aha, that can't be the best + +thing to do. + +I will make my regions +intervals. + +I will therefore simplify the +whole problem, and I'll also + +improve it. + +And when you can both simplify +things and improve them at the + +same time, it usually is worth +doing it unless you're dealing + +with standards bodies or +something, and then + +all bets are off. + +OK, so this one part of +the problem is easy. + +If we know what the +representation points are, we + +can solve the problem. + +OK, we have a second problem, +which is just + +the opposite problem. + +Suppose then that somebody gives +you the interval regions + +and asks you, OK, if I give you +these interval regions, + +how are you going to choose the +representation points to + +minimize the mean +square error? + +And analytically that's harder, +but conceptually, it's + +just about as easy. + +And let's look at it and see +if we can understand it. + +Somebody gives us this region +here, R sub 2, and says, OK, + +where should we put +the point a sub 2? + +Well, anybody have any +clues as to where + +you want to put it? + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: What? + +AUDIENCE: At the midpoint? + +PROFESSOR: At the midpoint. + +It sounds like a reasonable +thing, but + +it's not quite right. + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: What? + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: It depends on the +probability density, yes. + +If you have a probability +density, which is highly + +weighted over on -- let's see, +was I talking about R2 or R3? + +Well, it doesn't make +any difference. + +We'll talk about R2. + +If I have a probability density, +which looks like + +this, then I want a2 to be +closer to the left-hand side + +than to the right-hand side. + +I want it to be a little bit +weighted towards here because + +that's more important +in choosing + +the mean square error. + +OK, if you didn't have any of +this stuff, and I said how do + +I choose this to minimize the +mean square error, what's your + +answer then? + +If I just have one region and +I want to minimize the mean + +square error, what do you do? + +Anybody who doesn't know should +go back and study + +elementary probability theory +because this is almost day one + +of elementary probability theory +when you start to study + +what random variables +are all about. + +And the next thing you start +to look at is things like + +variance and second moment. + +And what I'm asking you here +is, how do you choose a2 in + +order to minimize the second +moment of U, whatever it is in + +here, minus a2? + +Yes? + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: I want to take +the expectation of U + +over the region R2. + +In other words, to say it more +technically, I want to take + +the expectation of the +conditional random variable U, + +conditional on being +in R2, OK? + +And all of you could figure that +out yourselves, if you + +sat down quietly and thought +about it for five minutes. + +If you got frightened about it +and started looking it up in a + +book or something, it +would take you about + +two hours to do it. + +But if you just asked +yourselves, how do I do it? + +You'll come up with the right +answer very, very soon, OK? + +So subproblem 2 says let's +look at the conditional + +density of U in this +region R sub j. + +I'll call the conditional +density -- well, the + +conditional density, given that +you're in this region, + +is, in fact, the real density +divided by the probability of + +being in that interval, OK? + +So we'll call that the +conditional density. + +And I'll let U of j be the +random variable, which has + +this density. + +In other words, this isn't +a random variable on the + +probability space that we +started to deal with it. + +It's sort of a phony +random variable. + +But, in fact, it's the +intuitive thing that + +you think of, OK? + +In other words, if this is +exactly what you were thinking + +of, you probably wouldn't have +called this a separate random + +variable, OK? + +So this is a random variable +with this density. + +The expected value of U of j +minus a of j quantity squared, + +as you all know, is sigma +squared of U of j plus the + +expected value a U of j minus a +sub j quantity squared, OK? + +How do you minimize this? + +Well, you're stuck with this. + +This term, you minimize it by +making a sub j equal to the + +expected value of +U of j, which is + +exactly what you said. + +Namely, you set a of j to be the +conditional mean of U of j + +conditional on being +in the center. + +It's harder to say +mathematically than + +it is to see it. + +But, in fact, the intuitive +idea is exactly right. + +Namely, you condition your +random variable on being in + +that interval, and then what you +want to do is choose the + +mean within that interval, which +is exactly the sort of + +thing we were thinking +about here. + +When I drew this curve here, if +I scale it, this, in fact, + +is the density of +u conditional on + +being in R sub j. + +And now all I'm trying to do +is choose the point here, + +which happens to be +the mean which + +minimizes this second moment. + +The second moment, in fact, +is this mean square error. + +So, bingo! + +That's the second problem. + +Well, how do you put the +two problems together? + +Well, you can put it together +in two ways. + +One of them is to say, OK, well +then, clearly an optimal + +scalar quantizer has to +satisfy both of these + +conditions. + +Namely, the endpoints of the +regions have to be the + +midpoints of the representation +points, and the + +representation points have to +be the conditional means of + +the points within a region +that you start with. + +And then you say, OK, how +do I solve that problem? + +Well, if you're a computer +scientist, and sometimes it's + +good to be a computer scientist, +you say, well, I + +don't know how to solve the +problem, but generating an + +algorithm to solve the problem +is almost trivial. + +I start out with some +arbitrary set of + +representation points. + +That should be a capital M +because that's the number of + +points I'm allowed to use. + +Then the next step in the +algorithm is I choose these + +separation points to be b sub j +is the midpoint between the + +a's for each of these values. + +Then as soon as I get these +midpoints, I have a set of + +intervals, and my next step is +to say set a sub j is equal to + +the expected value of this +conditional random variable U + +of j where R sub j is now this +new interval for 1 less than + +or equal to j less than +or equal to M minus 1. + +This means it's open +on the left side. + +This means it's closed on the +right side, and since it's a + +probability density, it doesn't +make any difference + +what it is. + +I just wanted to give you an +explicit rule for what to do + +with probability zero when you +happen to wind up on that + +special point. + +OK, and then you iterate on +2 and 3 until you get a + +negligible improvement. + +And then you ask, of course, +well, if I got a negligible + +improvement this time, maybe +I'll get a bigger + +improvement next time. + +And that, of course, is true. + +And you then say, well, it's +possible that after I can't + +get any improvement anymore, +I still don't + +have the optimal solution. + +And that, of course, +is true also. + +But at least you have an +algorithm which makes sense + +and which, each time you try +it, you do a little better + +than you did before. + +Now, this mean square error for +any choice of regions and + +any choice of representation +points is going to be + +nonnegative because +it's an expected + +value of squared terms. + +The algorithm is nonincreasing +with iterations. + +In other words, the algorithm +is going down all the time. + +So you have zero down here. + +You have an algorithm which is +marching you down toward zero. + +It's not going to get to zero, +but it has to reach a minimum. + +That's a major theorem in +analysis, but you don't need + +any major theorems in analysis +to see this. + +You have a set of numbers, which +are decreasing all the + +time, and they're bounded +underneath. + +After awhile, you have to get +to some point, and you don't + +go any further. + +So it has a limit. + +So that's nice. + +So you have an algorithm +which has to converge. + +It can't keep on going. + +Well, it can keep on going +forever, but it keeps going on + +forever with smaller and +smaller improvements. + +So eventually, you might as well +stop because you're not + +getting anywhere. + +OK, well, those conditions +that we stated, the way a + +mathematician would say this, is +these Lloyd-Max conditions + +are necessary but not +sufficient, OK? + +In other words, any solution +to this problem that we're + +looking at has to have +the property that the + +representation points are the +conditional means of the + +intervals and the interval +boundaries are the midpoints + +between the representation +points. + +But that isn't necessarily +enough. + +Here's a simple example of +where it's not enough. + +Suppose you have a probability +density, which is running + +along almost zero, jumps up to +a big value, almost zero, + +jumps up to a big value, jumps +up to a big value. + +This intentionally is wider than +this and wider than this. + +In other words, there's a lot +more probability over here + +than there is here +or there is here. + +And you're unlucky, and you +start out somehow with points + +like a1 and a2, and you start +out with regions like R1 -- + +well, yeah, you want to start +out with points, a1 and a2. + +So you start out with a point +a1, which is way over here, + +and a point a2, which is +not too far over here. + +And your algorithm then says +pick the midpoint b1. + +Here the algorithm is +particularly simple because, + +since we're only using two +regions, all you need is one + +separator point. + +So we wind up with b1 here, +which is halfway + +between a1 and a2. + +a1 happens to be right in the +middle of that big interval + +there, and there's hardly +anything else here. + +So a1 just stays there as the +conditional mean, given that + +you're on this side. + +And a2 stays as the conditional +mean, given that + +you're over here, which means +that a2 is a little closer + +this big region than it is +to this region, but a2 is + +perfectly happy there. + +And we go back and +we iterate again. + +And we haven't changed b1, we +haven't changed a1, we haven't + +changed a2, and therefore, the +algorithm sticks there. + +Well, that's not surprising. + +I mean, you know that there are +many problems where you + +try to minimize things by +differentiating or all the + +different tricks you have for +minimizing things, and you + +very often find local minima. + +People call algorithms like this +hill-climbing algorithms. + +They should call them +valley-finding algorithms + +because we're sitting +at someplace. + +We try to find a better place. + +So we wind up moving +down into the + +valley further and further. + +Of course, if it's a real +geographical area, you finally + +wind up at the river. + +You then move down the river, +you wind up in the + +ocean and all that. + +But let's forgot about that. + +Let's just assume that there +aren't rivers or anything. + +That we just have some arbitrary +geographical area. + +We wind up in the bottom of a +valley, and we say, OK, are we + +at the minimum or not? + +Well, with hill climbing, you +can take a pair of binoculars, + +and you look around to see if +there's any higher peak + +someplace else. + +With valley seeking, +you can't do that. + +We're sitting there at the +bottom of the valley, and we + +have no idea whether there's a +better valley somewhere else + +or not, OK? + +So that's the trouble with +hill-climbing algorithms or + +valley-seeking algorithms. + +And that's exactly what +this algorithm does. + +This is called the Lloyd-Max +algorithm because a guy by the + +name of Lloyd at Bell Labs +discovered it, I think in '57. + +A guy by the name of Joel +Max discovered it again. + +He was at MIT in 1960, and +because all the information + +theorists around were at MIT at +that time, they called it + +the Max algorithm +for many years. + +And then somebody discovered +that Lloyd had done it three + +years earlier. + +Lloyd never even published it. + +So it became the Lloyd-Max +algorithm. + +And now there's somebody else +who did it even earlier, I + +think, so we should probably +take Max's name off it. + +But anyway, sometime when I +revise the notes, I will give + +the whole story of that. + +But I hope you see that +this algorithm + +is no big deal anyway. + +It was just people fortunately +looking at the question at the + +right time before too many other +people had looked at it. + +And Max unfortunately +looked at it. + +He was in a valley. + +He didn't see all the other +people had looked at it. + +But he became famous. + +He had his moment of time and +then sunk gradually into + +oblivion except when once +in awhile we call it the + +Lloyd-Max algorithm. + +Most people call it the Lloyd +algorithm, though, and I + +really should also. + +OK, vector quantization: +We talked about vector + +quantization a little bit. + +It's the idea of segmenting the +source outputs before you + +try to do the encoding. + +So we ask is scalar quantization +going to be the + +right approach? + +To answer that question, we want +to look at quantizing two + +sample values jointly and +drawing pictures. + +Incidentally, what's the +simplest way of quantizing + +that you can think of? + +And what do people who do simple +things call quantizers? + +Ever hear of an +analog-to-digital converter? + +That's what a quantizer is. + +And an analog-to-digital +converter, the way that + +everybody does it, is scalar. + +So that says that either the +people who implement things + +are very stupid, or there's +something pretty good about + +scalar quantization. + +But anyway, since this is a +course trying to find better + +ways of doing things, we ought +to investigate whether it is + +better to use vector +quantizers and + +what they result in. + +OK, well, the first thing that +we can do is look at + +quantizing two samples. + +In other words, when you want +to generalize a problem to + +vectors, I find it better to +generalize it to two vectors + +first and see what +goes on there. + +And one possible approach is to +use a rectangular grid of + +quantization regions. + +And as I'll show you in the +next slide, that really is + +just a camouflaged scalar +quantizer again. + +So you have a two-dimensional +region corresponding to two + +real samples. + +So you've got two real +numbers, U1 and U2. + +You're trying to map them into +a finite set of sample values + +of representation points. + +Since you're going to be +interested in the distortion + +between U1 and U2, between the +vector U1, U2, and your + +representation vector, a1, +a2, these points, these + +representation points, are going +to be two-dimensional + +points also. + +So if you start out by saying +let's put these points on a + +rectangular grid, well, we can +then look at it, and we say, + +well, given the points, how +do we choose the regions? + +You see, it's exactly +the same problem + +that you solved before. + +If I give you the points and +then I ask you, well, if we + +get a vector U1, U2 that's +there, what do we map it to? + +Well, we map it to the closest +thing, which means if we want + +to find these regions, we set +up these perpendicular + +bisectors halfway between the +representation points. + +So all of this is looking very +rectangular now because we + +started out with these +points rectangular. + +These lines are rectangular, and +now I say, well, is this + +really any different from +a scalar quantizer? + +And, of course, it isn't because +for this particular + +vector quantizer, I can first +ask the question, OK, here's + +U1, which is something +in this direction. + +How do I find regions +for that? + +Well, for U1, I just establish +these regions here. + +And then I say, OK, let's +look at U2 next. + +And then I look at things in +this direction, and I wind up + +in saying, OK, that's all +there is to the problem. + +I have a scalar quantizer +again. + +Everything that I said +before works. + +Now if you're a theoretician, +you go one step further, and + +you say, what this tells me is +that vector quantizers cannot + +be any worse than scalar +quantizers. + +Because, in fact, a vector +quantizer has a -- or at least + +a vector quantizer in two +dimensions -- has a scalar + +quantizer -- + +has two scalar quantizers +as a special case. + +And therefore, the amount of +square distortion that I wind + +up with in the vector case, +I can always get that -- + +whatever I can do with the +scalar quantizer, I can do + +just as well with a vector +quantizer by choosing it, in + +fact, to be rectangular +like this. + +And you can also get some +intuitive ideas that if + +instead of having IID random +variables, if U1 and U2 are + +very heavily correlated somehow +so that they're very + +close together, I mean, you +sort of get an engineering + +view of what you want to do. + +You want to take this +rectangular picture here. + +You want to skew it +around that way. + +And you want to have lots of +points going this way and not + +too many points going this way +because almost everything is + +going this way, and +there's not much + +going on in that direction. + +So you got some pictures +of what you want to do. + +These regions here, a little bit +of terminology, are called + +Voronoi regions. + +Anytime you start out with a +set of points and you put + +perpendicular bisectors in +between those points, halfway + +between the points, you call the +regions that you wind up + +with Voronoi regions. + +So, in fact, part of this +Lloyd-Max algorithm, + +generalized at two dimensions, +says given any set of points, + +the regions ought to be the +Voronoi regions for them. + +So that's that first subproblem +generalized at two + +dimensions. + +And if you have an arbitrary +set of points, the Voronoi + +regions look sort of +like this, OK? + +And I've only drawn it for the +center point because, well, + +there aren't enough points to +do anything more than that. + +So anything in this region gets +mapped into this point. + +Anything in this semi-infinite +region gets mapped into this + +point and so forth. + +So even in two dimensions, +this part of the + +algorithm is simple. + +When you start out with the +regions, with almost the same + +argument that we used before, +you can see that the mean + +square error is going to be +minimized by using conditional + +means for the representation +points. + +I mean, that's done in +detail in the notes. + +It's just algebra to do that. + +It's sort of intuitive that +the same thing ought to + +happen, and in fact, it does. + +So you can still find +a local minimum by + +this Lloyd-Max algorithm. + +If you're unhappy with the +fact that the Lloyd-Max + +algorithm doesn't always work +in one dimension, be content + +with the fact that it's far +worse in two dimensions, and + +it gets worse and worse as you +go to higher numbers of + +dimensions. + +So it is a local minimum, +but not + +necessarily the best thing. + +OK, well, about that time, and +let's go forward for maybe 10 + +years from 1957 and '60 when +people were inventing the + +Lloyd-Max algorithm and where +they thought that quantization + +was a really neat academic +problem, and many people were + +writing theses on it and having +lots of fun with it. + +And then eventually, they +started to realize that when + +you try to solve that problem +and find the minimum, it + +really is just a very +ugly problem. + +At least it looks like a very +ugly problem with everything + +that anybody knows after +having worked on it + +for a very long time. + +So not many people work +on this anymore. + +So we stop and say, well, we +really don't want to go too + +far on this because it's ugly. + +But then we stop and think. + +I mean, anytime you get stuck +on a problem, you ought to + +stop and ask, well, am +I really looking + +at the right problem? + +Now why am I or why am I not +looking at the right problem? + +And remember where +we started off. + +We started off with this kind +of layered solution, which + +said we were going to quantize +these things into a finite + +alphabet and then +we were going to + +discrete code them, OK? + +And here what we've been +doing for awhile, + +and none of you objected. + +Of course, it's hard to object +at 9:30 in the morning. + +You just listen and you -- but +you should have objected. + +You should have said why in hell +am I choosing the number + +of quantization levels +to minimize over? + +What should I be minimizing +over? + +I should be trying to find the +minimum mean square error + +conditional on the entropy +of this output alphabet. + +Because the entropy of the +output alphabet is what + +determines what I can accomplish +by discrete coding. + +That's a slightly phony problem +because I'm insisting, + +now at least to start with, that +the quantizer is a scalar + +quantizer, and by using coding +here, I'm allowing memory in + +the coding process. + +But it's not that phony +because, in fact, this + +quantization job is a real +mess, and this job + +is very, very easy. + +And, in fact, when you think +about it a little bit, you + +say, OK, how do people really +do this if they're trying to + +implement things? + +And how would you go about +implementing something like + +this entire problem that +we're talking about? + +What would you do if you +had to implement it? + +Well, you're probably afraid to +say it, but you would use + +digital signal processing, +wouldn't you? + +I mean, the first thing you +would try to do is to get rid + +of all these analog values, and +you would try to turn them + +into discrete values, so that +you would really, after you + +somehow find this sequence of +numbers here, you would go + +through a quantizer and quantize +these numbers very, + +very finely. + +You would think of them as real +numbers, and then you + +would do some kind of discrete +coding, and you would wind up + +with something. + +And then you would say, ah, I +have quantized these things + +very, very finely. + +And we'll see that when you +quantize it very, very finely, + +what you're going to wind up +with, which is almost optimal, + +is a uniform scalar quantizer, +which is just what a + +garden-variety analog-to-digital +converter + +does for you, OK? + +But then you say, aha! + +What I can't do at that moment, +I don't have enough + +bits to represent what this very +fine quantizer has done. + +So then I think of this +quantization as real numbers. + +I go through the same process +again, and I think of then + +quantizing the real numbers +to the number of + +bits I really want. + +Anybody catch what +I just said? + +I'm saying you do this +in two steps. + +The first step is a very fine +quantization, strictly for + +implementation purposes and +for no other reason. + +And at that point, you +have bits to process. + +You do digital-signal +processing, but you think of + +those bits as representing +numbers, OK? + +In other words, as far as your +thoughts are concerned, you're + +not dealing with the +quantization errors that + +occurred here at all. + +You're just thinking +of real numbers. + +And at that point, you try to +design conceptually what it is + +you want to do in this +process of quantizing + +and discrete coding. + +And you then go back to looking +at these things as + +numbers again, and you quantize +them again, and you + +discrete encode them again in +whatever way makes sense. + +So you do one thing strictly for +implementation purposes. + +You do the other thing for +conceptual purposes. + +Then you put them together into +something that works. + +And that's the way engineers +operate all the time, I think. + +At least they did when I was +more active doing real + +engineering. + +OK, so that's that. + +But anyway, it says finding a +minimum mean square error + +quantizer for fixed M isn't the +right problem that we're + +interested in. + +If you're going to have +quantization followed by + +discrete coding, the quantizer +should minimize mean square + +error for fixed representation +point entropy. + +In other words, I'd +want to find these + +representation points. + +It's important what the +numerical values of the + +representation points are for +mean square error, but I'm not + +interested in how many +of them I have. + +What I'm interested in is +the entropy of them. + +OK, so the quantizer should +minimize mean square error for + +a fixed representation +point entropy. + +I would like some algorithm, +which goes through and changes + +my representation points, +including perhaps changing the + +number of representation +points as a + +way of reducing entropy. + +OK, sometimes you can get more +representation points by + +having them out where there's +virtually no probability, and + +therefore they don't happen very +often, but when they do + +happen, they sure save +you an awful lot + +of mean square error. + +So you can wind up with things +using many, many more + +quantization points than you +would think you would want + +because that's the optimal +thing to do. + +OK, when you're given the +regions, if we try to say what + +happens to the Lloyd-Max +algorithm then, the + +representation points +should still be + +the conditional means. + +Why? + +Anybody figure out why we want +to solve the problem that way? + +If I've already figured out what +the region should the -- + +well, before, when I told you +what the regions were, you + +told me that you wanted to make +the representation points + +the conditional means. + +Now if I make the representation +points + +something other than the +conditional means, what's + +going to happen to +the entropy? + +The entropy stays the same. + +The entropy has nothing +to do with what + +you call these symbols. + +I can move where they are, but +they still have the same + +probability because they still +occur whenever you wind up in + +that region. + +And therefore, the entropy +doesn't change, and therefore, + +the same rule holds. + +But now the peculiar thing is +you don't want to make the + +representation regions Voronoi +regions anymore. + +In other words, sometimes you +want to make a region much + +closer to one point than +to the other point. + +And why do you want +to do that? + +Because you'd like to make these +probabilities of the + +points as unequal as you can +because you're trying to + +reduce entropy. + +And you can reduce entropy by +making things have different + +probabilities. + +OK, so that's where we +wind up with that. + +I would like to say there's +a nice algorithm + +to solve this problem. + +There isn't. + +It's an incredibly +ugly problem. + +You might think it makes sense +to use a Lagrange multiplier + +approach and try to minimize +some linear combination of + +entropy and mean square error. + +I've never been able +to make it work. + +So anyway, let's go on. + +When we want to look at a +high-rate quantizer, which is + +what we very often want, you +can do a very simple + +approximation. + +And the simple approximation +makes the problem much easier, + +and it gives you an +added benefit. + +There's something called +differential entropy. + +And differential entropy is the +same as ordinary entropy, + +except instead of dealing with +probabilities, it deals with + +probability densities. + +And you look at this, and you +say, well, that's virtually + +the same thing, and it looks +like the same thing. + +And to most physicists, most +physicists look at something + +like this, and physicists who +are into statistical mechanics + +say, oh, of course that's +the same thing. + +There's no fundamental +difference between a + +differential entropy +and a real entropy. + +And you say, well, but +they're all these + +scaling issues there. + +And they say, blah, that's +not important. + +And they're right, because once +you understand it, it's + +not important. + +But let's look and see what the +similarities and what the + +differences are. + +And I'll think in terms of, in +fact, a quantization problem, + +where I'm taking this +continuous-valued random + +variable with density, and I'm +quantizing it into a set of + +discrete points. + +And I want to say what's the +difference between this + +differential entropy here and +this discrete entropy, which + +we sort of understand by now. + +Well, things that are the same +-- the first thing that's the + +same is the differential entropy +is still the expected + +value of minus the logarithm +of the probability density. + +OK, we found that that was +useful before when we were + +trying to understand +the entropy. + +It's the expected value +of a log pmf. + +Now the differential entropy is +expected value of a log pdf + +instead of pmf. + +And the entropy of two random +variables, U1 and U2, if + +they're independent, is just the +differential entropy of U1 + +plus the differential +entropy of U2. + +How do I see that? + +You just write it down. + +You write down these +joint densities. + +You write down this. + +The logarithm of the joint +density for IID splits into a + +product of densities. + +A log of a product is +the sum of the logs. + +It's the same as the +argument before. + +In other words, it's not only +that this is the same as the + +answer that we got before, +but the argument + +is exactly the same. + +And the other thing, the next +thing is if you shift this + +density here. + +If I have a density, which is +going along here and I shift + +it over to here and have a +density over there, the + +entropy is the same again. + +Because this entropy is just +fundamentally not -- it + +doesn't have to do with where +you happen to be. + +It has to do with what these +probability densities are. + +And you can stick that shift +into here, and if you're very + +good at doing calculus, you can, +in fact, see that when + +you put a shift in here, you +still get the same entropy. + +I couldn't do that at this +point, but I'm sure that all + +of you can. + +And I can do it if +I spent enough + +time thinking it through. + +It would just take me longer +than most of you. + +OK, so all of these things +are still true. + +There a couple of +very disturbing + +differences, though. + +And the first difference +is that h of U + +is not scale invariant. + +And, in fact, if it were +scale invariant, it + +would be totally useless. + +The fact that it's not scale +invariant turns out to be very + +important when you try +to understand it, OK? + +In other words, if you stretch +this probability density by + +some quantity a, then your +probability density, which + +looks like this, shifts +like this. + +It shifts down and +it shifts out. + +So the log of the +pmf gets bigger. + +The pmf itself is just +sort of spread out. + +It does what you would +expect it to do, and + +that works very nicely. + +But the log of the pmf has this +extra term which comes in + +here, which is a factor of a. + +And it turns out you can just +factor that factor of a out, + +and you wind up with the +differential entropy of a + +scaled random variable U is +equal to the differential + +entropy of the original U plus +log of a, which might be + +minus log of a. + +I'm not sure which it is. + +I'll write down plus +or minus log of a. + +It's one or the other. + +I don't care at this point. + +All I'm interested +in is that you + +recognize that it's different. + +An even more disturbing point +is this differential entropy + +can be negative. + +It can be negative +or positive. + +It can do whatever +it wants to do. + +And so we're left with a sort +of a peculiar thing. + +But we say, well, all right, +that's the way it is. + +The physicists had +to deal with that + +for many, many years. + +And the physicists, who think +about it all the time, deal + +with it and say it's +not very important. + +So we'll say, OK, we'll go along +with this unless asked: + +What happens if we try to build +a uniform high-rate + +scalar quantizer, which is +exactly what you would do for + +implementation purposes +anyway. + +So how does this work? + +You pick a little tiny delta. + +You have all these +regions here. + +And by uniform, I mean you make +all the regions the same. + +I mean, conceptually, this might +mean having accountably + +infinite number of regions. + +Let's not worry about that +for the time being. + +And you have points in here, +which are the conditional + +means of the regions. + +Well, if I assume that delta is +small, then the probability + +density of u is almost constant +within a region, if + +it really is a density. + +And I can define an average +value of f of u within each + +region in the following way. + +It's easier to see what it is +graphically if I have a + +density here, which runs +along like this. + +And within each region, I will +choose f-bar of u to be a + +piecewise constant version of +this density, which might be + +like that, OK? + +Now that's just analytical +stuff to make + +things come out right. + +If you read the notes about how +to do this, you find out + +that this quantity is important +analytically to + +trace through what's going on. + +I think for the level that we're +at now, it's fine to + +just say, OK, this is the same +as this, if we make the + +quantization very small. + +I mean, at some point in this +argument, you want to go + +through and say, OK, what do +I mean by approximate? + +Is the approximation close? + +How does the approximation +become better as I make delta + +smaller, and all of +these questions. + +But let's just now say, OK, this +is the same as that, and + +I'd like to find out how well +this uniform high-rate scalar + +quantizer does. + +So my high-rate approximation +is that this average density + +is the same as the true +density and for + +all possible u. + +So conditional on u and Rj, +this quantity is constant. + +It's constant and equal to 1 +over delta, and the actual + +density is approximately +equal to 1 over delta. + +What's that mean? + +It means that the mean square +error in one of these + +quantization regions is our +usual delta squared over 12, + +which is the mean square error +of a uniform density in a + +region from minus delta over +2 to plus delta over 2. + +So that's the mean +square error. + +You can't do anything +with that. + +You're stuck with it. + +The next question is +what is the entropy + +as a quantizer output? + +I'm sorry, I'm giving a typical +MIT lecture today, + +which people have characterized +as a fire hose, + +and it's because I want to get +done with this material today. + +I think if you read the notes +afterwards, you've got a + +pretty good picture of +what's going on. + +We are not going to have +an enormous number + +of problems on this. + +It's not something we're +stressing so I want to get you + +to have some idea of what +this is all about. + +This slide is probably the most +important slide because + +it tells you what this +differential + +entropy really is. + +OK, I'm going to look at the +probabilities of each of these + +discrete points now. p sub j +is the probability that the + +quantizer will get the +point a sub j. + +In other words, it is the +probability of the + +region R sub j. + +And that's just the integral +of the probability density + +over the j-th region. + +Namely, it's the probability of +being in that j-th region. + +p sub j is also equal to this +average value times delta. + +OK, so I look at what +the entropy is of + +the high-rate quantizer. + +It's the sum of minus +pj log pj. + +I translate that pj is +equal to this, so I + +have a sum over j. + +I have an integral minus a fU of +u, which is that, times log + +And now I'll use this quantity +instead of this quantity. + +f-bar of u times delta du. + +OK, in other words, these +probabilities are scaled by + +delta, which is what I was +telling you before. + +That's the crucial thing here. + +As you make delta smaller and +smaller, the probabilities of + +the intervals go down +with delta. + +OK, so I break this up +into two terms now. + +I take out the log of delta, +which is integrated over fU. + +I have this quantity left. + +This quantity is approximately +equal to the density, and what + +I wind up with is that the +actual entropy of the + +quantized version is equal to +the differential entropy minus + +the log of delta at high rate. + +OK, that's the only way I know +to interpret differential + +entropy that makes any sense, +OK, in other words, usually + +when you think of integrals, +you think of them + +in a Riemann sense. + +You think of breaking up the +interval into lots of very + +thin slices with delta, and then +you integrate things by + +adding up things, and that +integral then is then a sum. + +It's the same as this +kind of sum. + +And the integral that you wind +up with when you're dealing + +with a log of the pmf, you +get this extra delta + +sticking in there, OK? + +So this entropy is this phony +thing minus log of delta. + +As I quantize more and +more finely, this + +entropy keeps going up. + +It goes up because when delta is +very, very small, minus log + +delta is a large number. + +So as delta gets smaller and +smaller, this entropy heads + +off towards infinity. + +And in fact, you would expect +that because if you take a + +real number, which has a +distribution which is -- well, + +anything just between minus 1 +and plus 1, for example, and I + +want to represent it very, very +well if it's uniformly + +distributed there, the better +I try to represent it, the + +more bits it takes. + +That's what this is saying. + +This thing is changing as I try +to represent things better + +and better. + +This quantity here is just some +funny thing that deals + +with the shape of the +probability density and + +nothing else. + +It essentially has a scale +factor built into it because + +the probability density has a +scale factor built into it. + +A probability density is +probability per unit length. + +And therefore, this kind of +entropy has to have that unit + +length coming in here somehow, +and that's the + +way it comes in. + +That's the way it is. + +So to summarize all of that, and +I'm sure you haven't quite + +understood all of it, but if +you do efficient discrete + +coding at the end of the whole +thing, the number of bits per + +sample, namely, per number +coming into the quantizer that + +you need, is H of V, OK? + +With this uniform quantizer, +which produces an entropy of + +the symbols H of V, then you +L-bar bits per symbol to + +represent that. + +That's the result that +we had before. + +This quantity H of V depends +only on delta and h of U. + +Namely, h of U is equal to +H of V plus log delta. + +So, in other words, +analytically, the only thing + +you have to worry about +is what is this + +differential entropy? + +You can't interpret what it is, +but you can calculate it. + +And once you calculate it, +this tells you what this + +entropy is for every +choice of delta so + +long as delta is small. + +It says that when you get to the +point where delta is small + +and the probability density is +essentially constant over a + +region, if I want to make delta +half as big as it was + +before, then I'm going to wind +up with twice as many + +quantization regions. + +They're all going to +be only half as + +probable as the ones before. + +It's going to take me +one extra bit to + +represent that, OK? + +Namely, this one extra bit for +each of these old regions is + +going to tell me whether I'm on +the right side or the left + +side of that old quantization +region to talk about the new + +quantization region. + +So this all make sense, OK? + +Namely, the only thing that's +happening as you make the + +quantization finer and finer is +that you have these extra + +bits coming in, which are sort +of telling you what the fine + +structure is. + +And little h of U already has +built into it the overall + +shape of the thing. + +OK, now I've added one thing +more here, which I haven't + +talked about at all. + +This uniform scalar quantizer +in fact becomes optimal as + +delta become small. + +And that's not obvious; +it's not intuitive. + +There's an argument +in the text that + +shows why that is true. + +It uses a Lagrange multiplier +to do it. + +I guess there's a certain +elegance to it. + +I mean, after years of thinking +about it, I would + +say, yeah, it's pretty likely +that it's true if I didn't + +have the mathematics +to know it's true. + +But, in fact, it's a very +interesting result. + +It says that what you do with +classical a to z converters, + +if you're going to have very +fine quantization, is, in + +fact, the right thing to do. \ No newline at end of file diff --git a/rzD4knm4--I.txt b/rzD4knm4--I.txt new file mode 100644 index 0000000000000000000000000000000000000000..e2b9d63a9cb20178bc614f1c7f32fd577909b7ed --- /dev/null +++ b/rzD4knm4--I.txt @@ -0,0 +1,571 @@ +align:start position:0% + +hi this is Tanya from the publication + + align:start position:0% +hi this is Tanya from the publication + + + align:start position:0% +hi this is Tanya from the publication +team at MIT opencourseware I'd like to + + align:start position:0% +team at MIT opencourseware I'd like to + + + align:start position:0% +team at MIT opencourseware I'd like to +show you a course called toy product + + align:start position:0% +show you a course called toy product + + + align:start position:0% +show you a course called toy product +design in this class students work in + + align:start position:0% +design in this class students work in + + + align:start position:0% +design in this class students work in +small teams to design and prototype new + + align:start position:0% +small teams to design and prototype new + + + align:start position:0% +small teams to design and prototype new +toys all of this takes place in the MIT + + align:start position:0% +toys all of this takes place in the MIT + + + align:start position:0% +toys all of this takes place in the MIT +toy lab which was founded in 2004 by + + align:start position:0% +toy lab which was founded in 2004 by + + + align:start position:0% +toy lab which was founded in 2004 by +Professor David Wallace I worked with + + align:start position:0% +Professor David Wallace I worked with + + + align:start position:0% +Professor David Wallace I worked with +graduate student Barry cudgerowitz on + + align:start position:0% +graduate student Barry cudgerowitz on + + + align:start position:0% +graduate student Barry cudgerowitz on +this course site he developed and + + align:start position:0% +this course site he developed and + + + align:start position:0% +this course site he developed and +teaches the class + + align:start position:0% +teaches the class + + + align:start position:0% +teaches the class +in the project section you'll see all of + + align:start position:0% +in the project section you'll see all of + + + align:start position:0% +in the project section you'll see all of +the things students have developed let's + + align:start position:0% +the things students have developed let's + + + align:start position:0% +the things students have developed let's +take a look at 2006 where the theme was + + align:start position:0% +take a look at 2006 where the theme was + + + align:start position:0% +take a look at 2006 where the theme was +toys to promote good dental hygiene + + align:start position:0% +toys to promote good dental hygiene + + + align:start position:0% +toys to promote good dental hygiene +here's r2d tooth he's the work of the + + align:start position:0% +here's r2d tooth he's the work of the + + + align:start position:0% +here's r2d tooth he's the work of the +red team + + align:start position:0% +red team + + + align:start position:0% +red team +they call it the ultimate robotic dental + + align:start position:0% +they call it the ultimate robotic dental + + + align:start position:0% +they call it the ultimate robotic dental +hygiene sync top assistant + + align:start position:0% +hygiene sync top assistant + + + align:start position:0% +hygiene sync top assistant +you can see that R2 holds a lightsaber + + align:start position:0% +you can see that R2 holds a lightsaber + + + align:start position:0% +you can see that R2 holds a lightsaber +toothbrush that lights up when you use + + align:start position:0% +toothbrush that lights up when you use + + + align:start position:0% +toothbrush that lights up when you use +it + + align:start position:0% +it + + + align:start position:0% +it +students worked with mentors from a + + align:start position:0% +students worked with mentors from a + + + align:start position:0% +students worked with mentors from a +local toy company and a dental hygienist + + align:start position:0% +local toy company and a dental hygienist + + + align:start position:0% +local toy company and a dental hygienist +from MIT medical to develop their ideas + + align:start position:0% +from MIT medical to develop their ideas + + + align:start position:0% +from MIT medical to develop their ideas +they also visited students at a local + + align:start position:0% +they also visited students at a local + + + align:start position:0% +they also visited students at a local +school to get feedback on their + + align:start position:0% +school to get feedback on their + + + align:start position:0% +school to get feedback on their +preliminary designs + + align:start position:0% +preliminary designs + + + align:start position:0% +preliminary designs +the theme for 2007 was toys that could + + align:start position:0% +the theme for 2007 was toys that could + + + align:start position:0% +the theme for 2007 was toys that could +be inexpensively manufactured in Brazil + + align:start position:0% +be inexpensively manufactured in Brazil + + + align:start position:0% +be inexpensively manufactured in Brazil +here's Eggman and Friends a collection + + align:start position:0% +here's Eggman and Friends a collection + + + align:start position:0% +here's Eggman and Friends a collection +of six egg-shaped tops that have a + + align:start position:0% +of six egg-shaped tops that have a + + + align:start position:0% +of six egg-shaped tops that have a +special power when you spin them such as + + align:start position:0% +special power when you spin them such as + + + align:start position:0% +special power when you spin them such as +singing each egg comes in a special egg + + align:start position:0% +singing each egg comes in a special egg + + + align:start position:0% +singing each egg comes in a special egg +carton with a lightning bolt lock + + align:start position:0% +carton with a lightning bolt lock + + + align:start position:0% +carton with a lightning bolt lock +of course it's not all just fun and play + + align:start position:0% +of course it's not all just fun and play + + + align:start position:0% +of course it's not all just fun and play +in addition to working in the toy lab + + align:start position:0% +in addition to working in the toy lab + + + align:start position:0% +in addition to working in the toy lab +students attend lectures and complete + + align:start position:0% +students attend lectures and complete + + + align:start position:0% +students attend lectures and complete +reading assignments to learn about + + align:start position:0% +reading assignments to learn about + + + align:start position:0% +reading assignments to learn about +things like ergonomics and safety + + align:start position:0% +things like ergonomics and safety + + + align:start position:0% +things like ergonomics and safety +half of the total grade is based on + + align:start position:0% +half of the total grade is based on + + + align:start position:0% +half of the total grade is based on +individual work and the other half is + + align:start position:0% +individual work and the other half is + + + align:start position:0% +individual work and the other half is +based on teamwork + + align:start position:0% +based on teamwork + + + align:start position:0% +based on teamwork +each team has to come up with three + + align:start position:0% +each team has to come up with three + + + align:start position:0% +each team has to come up with three +sketch models then select two for + + align:start position:0% +sketch models then select two for + + + align:start position:0% +sketch models then select two for +mock-up designs + + align:start position:0% +mock-up designs + + + align:start position:0% +mock-up designs +finally each team takes one of its ideas + + align:start position:0% +finally each team takes one of its ideas + + + align:start position:0% +finally each team takes one of its ideas +all the way to completion + + align:start position:0% +all the way to completion + + + align:start position:0% +all the way to completion +students are provided with many + + align:start position:0% +students are provided with many + + + align:start position:0% +students are provided with many +resources to guide them and stimulate + + align:start position:0% +resources to guide them and stimulate + + + align:start position:0% +resources to guide them and stimulate +ideas and we've included them on the + + align:start position:0% +ideas and we've included them on the + + + align:start position:0% +ideas and we've included them on the +site + + align:start position:0% +site + + + align:start position:0% +site +at the end of the course students + + align:start position:0% +at the end of the course students + + + align:start position:0% +at the end of the course students +present their prototypes at the + + align:start position:0% +present their prototypes at the + + + align:start position:0% +present their prototypes at the +playsentations an event where they + + align:start position:0% +playsentations an event where they + + + align:start position:0% +playsentations an event where they +present their work to toy designers + + align:start position:0% +present their work to toy designers + + + align:start position:0% +present their work to toy designers +Engineers elementary schools children + + align:start position:0% +Engineers elementary schools children + + + align:start position:0% +Engineers elementary schools children +and the MIT community + + align:start position:0% +and the MIT community + + + align:start position:0% +and the MIT community +by the way ocw's site for toy product + + align:start position:0% +by the way ocw's site for toy product + + + align:start position:0% +by the way ocw's site for toy product +design can be downloaded for use offline + + align:start position:0% +design can be downloaded for use offline + + + align:start position:0% +design can be downloaded for use offline +the link and instructions are right here + + align:start position:0% +the link and instructions are right here + + + align:start position:0% +the link and instructions are right here +I enjoyed working on this course and I + + align:start position:0% +I enjoyed working on this course and I + + + align:start position:0% +I enjoyed working on this course and I +hope you'll enjoy exploring it + + align:start position:0% +hope you'll enjoy exploring it + + + align:start position:0% +hope you'll enjoy exploring it +foreign + + align:start position:0% + + + + align:start position:0% + +you can explore more courses like this + + align:start position:0% +you can explore more courses like this + + + align:start position:0% +you can explore more courses like this +one at + + align:start position:0% +one at + + + align:start position:0% +one at +ocw.mit.edu or get email updates from + + align:start position:0% +ocw.mit.edu or get email updates from + + + align:start position:0% +ocw.mit.edu or get email updates from +MIT opencourseware by subscribing to our + + align:start position:0% +MIT opencourseware by subscribing to our + + + align:start position:0% +MIT opencourseware by subscribing to our +monthly newsletter we hope you'll help + + align:start position:0% +monthly newsletter we hope you'll help + + + align:start position:0% +monthly newsletter we hope you'll help +us keep going and growing by making a + + align:start position:0% +us keep going and growing by making a + + + align:start position:0% +us keep going and growing by making a +donation at + + align:start position:0% +donation at + + + align:start position:0% +donation at +ocw.mit.edu donate \ No newline at end of file diff --git a/s8dZi6eqsJU.txt b/s8dZi6eqsJU.txt new file mode 100644 index 0000000000000000000000000000000000000000..14ecaa970fb4cc4bf7b992fb952c1e80057ec4fa --- /dev/null +++ b/s8dZi6eqsJU.txt @@ -0,0 +1,4243 @@ +align:start position:0% + +The following content is provided under + + align:start position:0% +The following content is provided under + + + align:start position:0% +The following content is provided under +a Creative Common License. Your support + + align:start position:0% +a Creative Common License. Your support + + + align:start position:0% +a Creative Common License. Your support +will help MIT Open Courseware continue + + align:start position:0% +will help MIT Open Courseware continue + + + align:start position:0% +will help MIT Open Courseware continue +to offer high-quality educational + + align:start position:0% +to offer high-quality educational + + + align:start position:0% +to offer high-quality educational +resources for free. To make a donation + + align:start position:0% +resources for free. To make a donation + + + align:start position:0% +resources for free. To make a donation +or view additional materials from + + align:start position:0% +or view additional materials from + + + align:start position:0% +or view additional materials from +hundreds of MIT courses, visit MIT Open + + align:start position:0% +hundreds of MIT courses, visit MIT Open + + + align:start position:0% +hundreds of MIT courses, visit MIT Open +Courseware at ocw.mmit.edu. + + align:start position:0% + + + + align:start position:0% + +So I'm Arvin and this is Micah and we + + align:start position:0% +So I'm Arvin and this is Micah and we + + + align:start position:0% +So I'm Arvin and this is Micah and we +work together on a framework for + + align:start position:0% +work together on a framework for + + + align:start position:0% +work together on a framework for +flexible stream processing on the cell. + + align:start position:0% +flexible stream processing on the cell. + + + align:start position:0% +flexible stream processing on the cell. +So we were also oriented towards an + + align:start position:0% +So we were also oriented towards an + + + align:start position:0% +So we were also oriented towards an +application which is in this case is + + align:start position:0% +application which is in this case is + + + align:start position:0% +application which is in this case is +software radio and we use this + + align:start position:0% +software radio and we use this + + + align:start position:0% +software radio and we use this +application as a case study. Where's the + + align:start position:0% +application as a case study. Where's the + + + align:start position:0% +application as a case study. Where's the +mic? Okay, I'll try and speak as loud as + + align:start position:0% +mic? Okay, I'll try and speak as loud as + + + align:start position:0% +mic? Okay, I'll try and speak as loud as +I can. So our project was about flexible + + align:start position:0% +I can. So our project was about flexible + + + align:start position:0% +I can. So our project was about flexible +flexible stream processing framework for + + align:start position:0% +flexible stream processing framework for + + + align:start position:0% +flexible stream processing framework for +the cell and we used the software radio + + align:start position:0% +the cell and we used the software radio + + + align:start position:0% +the cell and we used the software radio +as an as a case study essentially of an + + align:start position:0% +as an as a case study essentially of an + + + align:start position:0% +as an as a case study essentially of an +application we could build using this + + align:start position:0% +application we could build using this + + + align:start position:0% +application we could build using this +framework. The motivation for our + + align:start position:0% +framework. The motivation for our + + + align:start position:0% +framework. The motivation for our +project is essentially what we've been + + align:start position:0% +project is essentially what we've been + + + align:start position:0% +project is essentially what we've been +discussing in class. It's been + + align:start position:0% +discussing in class. It's been + + + align:start position:0% +discussing in class. It's been +reiterated. The cell isn't easy to + + align:start position:0% +reiterated. The cell isn't easy to + + + align:start position:0% +reiterated. The cell isn't easy to +program. There's no shared memory. + + align:start position:0% +program. There's no shared memory. + + + align:start position:0% +program. There's no shared memory. +There's just message passing which is + + align:start position:0% +There's just message passing which is + + + align:start position:0% +There's just message passing which is +quite messy. You have to explicitly + + align:start position:0% +quite messy. You have to explicitly + + + align:start position:0% +quite messy. You have to explicitly +paralyze your programs if you want to + + align:start position:0% +paralyze your programs if you want to + + + align:start position:0% +paralyze your programs if you want to +write them as say custom C programs. + + align:start position:0% +write them as say custom C programs. + + + align:start position:0% +write them as say custom C programs. +Some of the groups have described the + + align:start position:0% +Some of the groups have described the + + + align:start position:0% +Some of the groups have described the +challenges they faced when doing that. + + align:start position:0% +challenges they faced when doing that. + + + align:start position:0% +challenges they faced when doing that. +Extracting parallelism can be tricky. + + align:start position:0% +Extracting parallelism can be tricky. + + + align:start position:0% +Extracting parallelism can be tricky. +For example, if you want to do + + align:start position:0% +For example, if you want to do + + + align:start position:0% +For example, if you want to do +pipelining, then on the SPEs, you have + + align:start position:0% +pipelining, then on the SPEs, you have + + + align:start position:0% +pipelining, then on the SPEs, you have +to predict what addresses you're going + + align:start position:0% +to predict what addresses you're going + + + align:start position:0% +to predict what addresses you're going +to require and set up the DMA so that + + align:start position:0% +to require and set up the DMA so that + + + align:start position:0% +to require and set up the DMA so that +those addresses are fetched in advance. + + align:start position:0% +those addresses are fetched in advance. + + + align:start position:0% +those addresses are fetched in advance. +And as Bill mentioned in his talk in + + align:start position:0% +And as Bill mentioned in his talk in + + + align:start position:0% +And as Bill mentioned in his talk in +class, stream programming can help + + align:start position:0% +class, stream programming can help + + + align:start position:0% +class, stream programming can help +alleviate some of these issues for some + + align:start position:0% +alleviate some of these issues for some + + + align:start position:0% +alleviate some of these issues for some +applications like software radio where + + align:start position:0% +applications like software radio where + + + align:start position:0% +applications like software radio where +the applications fit naturally into the + + align:start position:0% +the applications fit naturally into the + + + align:start position:0% +the applications fit naturally into the +streaming model. So what we tried to do + + align:start position:0% +streaming model. So what we tried to do + + + align:start position:0% +streaming model. So what we tried to do +for our project was build a lightweight + + align:start position:0% +for our project was build a lightweight + + + align:start position:0% +for our project was build a lightweight +as lightweight as possible because the + + align:start position:0% +as lightweight as possible because the + + + align:start position:0% +as lightweight as possible because the +code has to fit on the SPEs + + align:start position:0% +code has to fit on the SPEs + + + align:start position:0% +code has to fit on the SPEs +but as expressive as possible as well so + + align:start position:0% +but as expressive as possible as well so + + + align:start position:0% +but as expressive as possible as well so +as to simplify life for developers. The + + align:start position:0% +as to simplify life for developers. The + + + align:start position:0% +as to simplify life for developers. The +streaming framework which is targeted + + align:start position:0% +streaming framework which is targeted + + + align:start position:0% +streaming framework which is targeted +specifically at signal processing + + align:start position:0% +specifically at signal processing + + + align:start position:0% +specifically at signal processing +applications. So this is based on the + + align:start position:0% +applications. So this is based on the + + + align:start position:0% +applications. So this is based on the +data model at least is based on a + + align:start position:0% +data model at least is based on a + + + align:start position:0% +data model at least is based on a +research project that I have worked on + + align:start position:0% +research project that I have worked on + + + align:start position:0% +research project that I have worked on +in the past which is wave scope + + align:start position:0% +in the past which is wave scope + + + align:start position:0% +in the past which is wave scope +streaming database management system is + + align:start position:0% +streaming database management system is + + + align:start position:0% +streaming database management system is +a research project in the database + + align:start position:0% +a research project in the database + + + align:start position:0% +a research project in the database +group. The data model is essentially an + + align:start position:0% +group. The data model is essentially an + + + align:start position:0% +group. The data model is essentially an +extension of the streaming model to + + align:start position:0% +extension of the streaming model to + + + align:start position:0% +extension of the streaming model to +handle larger blocks of data so as to + + align:start position:0% +handle larger blocks of data so as to + + + align:start position:0% +handle larger blocks of data so as to +process them better. For example, + + align:start position:0% +process them better. For example, + + + align:start position:0% +process them better. For example, +several signal processing operators like + + align:start position:0% +several signal processing operators like + + + align:start position:0% +several signal processing operators like +the fast 4 year transform need to do + + align:start position:0% +the fast 4 year transform need to do + + + align:start position:0% +the fast 4 year transform need to do +multiple passes over their data and + + align:start position:0% +multiple passes over their data and + + + align:start position:0% +multiple passes over their data and +therefore trying to treat streams on a + + align:start position:0% +therefore trying to treat streams on a + + + align:start position:0% +therefore trying to treat streams on a +sample by sample basis leads to high + + align:start position:0% +sample by sample basis leads to high + + + align:start position:0% +sample by sample basis leads to high +cost scheduling overhead as well as + + align:start position:0% +cost scheduling overhead as well as + + + align:start position:0% +cost scheduling overhead as well as +inefficiency. + + align:start position:0% +inefficiency. + + + align:start position:0% +inefficiency. +So that's what the data model does and + + align:start position:0% +So that's what the data model does and + + + align:start position:0% +So that's what the data model does and +we tried to port this data model over to + + align:start position:0% +we tried to port this data model over to + + + align:start position:0% +we tried to port this data model over to +the cell processor and see how well we + + align:start position:0% +the cell processor and see how well we + + + align:start position:0% +the cell processor and see how well we +could exploit the features of the cell + + align:start position:0% +could exploit the features of the cell + + + align:start position:0% +could exploit the features of the cell +processor in particular the high onchip + + align:start position:0% +processor in particular the high onchip + + + align:start position:0% +processor in particular the high onchip +bandwidth between the SPEs to do + + align:start position:0% +bandwidth between the SPEs to do + + + align:start position:0% +bandwidth between the SPEs to do +streaming. So our case study was as you + + align:start position:0% +streaming. So our case study was as you + + + align:start position:0% +streaming. So our case study was as you +mentioned a simple software radio + + align:start position:0% +mentioned a simple software radio + + + align:start position:0% +mentioned a simple software radio +application it's really simple uses uh + + align:start position:0% +application it's really simple uses uh + + + align:start position:0% +application it's really simple uses uh +incoherent um demodulation as well as + + align:start position:0% +incoherent um demodulation as well as + + + align:start position:0% +incoherent um demodulation as well as +just simple amplitude shift key + + align:start position:0% +just simple amplitude shift key + + + align:start position:0% +just simple amplitude shift key +modulation. + + align:start position:0% +modulation. + + + align:start position:0% +modulation. +As I said, the main goals of our + + align:start position:0% +As I said, the main goals of our + + + align:start position:0% +As I said, the main goals of our +framework are to simplify life and + + align:start position:0% +framework are to simplify life and + + + align:start position:0% +framework are to simplify life and +automate as much parallelism as + + align:start position:0% +automate as much parallelism as + + + align:start position:0% +automate as much parallelism as +possible. Try and extract pipeline + + align:start position:0% +possible. Try and extract pipeline + + + align:start position:0% +possible. Try and extract pipeline +parallelism, data parallelism, some of + + align:start position:0% +parallelism, data parallelism, some of + + + align:start position:0% +parallelism, data parallelism, some of +the kinds of parallelism bill mentioned. + + align:start position:0% +the kinds of parallelism bill mentioned. + + + align:start position:0% +the kinds of parallelism bill mentioned. +The kind of parallelism we were able to + + align:start position:0% +The kind of parallelism we were able to + + + align:start position:0% +The kind of parallelism we were able to +finally implement. So far, it's only + + align:start position:0% +finally implement. So far, it's only + + + align:start position:0% +finally implement. So far, it's only +pipeline parallelism, but as future + + align:start position:0% +pipeline parallelism, but as future + + + align:start position:0% +pipeline parallelism, but as future +work, we'd be interested in the other + + align:start position:0% +work, we'd be interested in the other + + + align:start position:0% +work, we'd be interested in the other +kinds of parallelism as well. More about + + align:start position:0% +kinds of parallelism as well. More about + + + align:start position:0% +kinds of parallelism as well. More about +it as I go on. So, in our in the + + align:start position:0% +it as I go on. So, in our in the + + + align:start position:0% +it as I go on. So, in our in the +framework, we at least implemented the + + align:start position:0% +framework, we at least implemented the + + + align:start position:0% +framework, we at least implemented the +programming model is quite simple. The + + align:start position:0% +programming model is quite simple. The + + + align:start position:0% +programming model is quite simple. The +basic execution unit is what we call an + + align:start position:0% +basic execution unit is what we call an + + + align:start position:0% +basic execution unit is what we call an +operator. It's analogist to what in + + align:start position:0% +operator. It's analogist to what in + + + align:start position:0% +operator. It's analogist to what in +stream it would be called a work + + align:start position:0% +stream it would be called a work + + + align:start position:0% +stream it would be called a work +function or what in glue radio which is + + align:start position:0% +function or what in glue radio which is + + + align:start position:0% +function or what in glue radio which is +a framework for building software radios + + align:start position:0% +a framework for building software radios + + + align:start position:0% +a framework for building software radios +would be called a block. So these + + align:start position:0% +would be called a block. So these + + + align:start position:0% +would be called a block. So these +operators can be any arbitrary C++ + + align:start position:0% +operators can be any arbitrary C++ + + + align:start position:0% +operators can be any arbitrary C++ +classes with state and they implement uh + + align:start position:0% +classes with state and they implement uh + + + align:start position:0% +classes with state and they implement uh +an iterate method which the developer + + align:start position:0% +an iterate method which the developer + + + align:start position:0% +an iterate method which the developer +has to overload in order to process a + + align:start position:0% +has to overload in order to process a + + + align:start position:0% +has to overload in order to process a +block of data. Uh the waves scope data + + align:start position:0% +block of data. Uh the waves scope data + + + align:start position:0% +block of data. Uh the waves scope data +model also provides a library for + + align:start position:0% +model also provides a library for + + + align:start position:0% +model also provides a library for +managing memory and passing blocks of + + align:start position:0% +managing memory and passing blocks of + + + align:start position:0% +managing memory and passing blocks of +signal data between these operators. + + align:start position:0% +signal data between these operators. + + + align:start position:0% +signal data between these operators. +Applications in this model are built by + + align:start position:0% +Applications in this model are built by + + + align:start position:0% +Applications in this model are built by +chaining operators together. So this is + + align:start position:0% +chaining operators together. So this is + + + align:start position:0% +chaining operators together. So this is +a snippet of some of the code we wrote + + align:start position:0% +a snippet of some of the code we wrote + + + align:start position:0% +a snippet of some of the code we wrote +for the software radio roughly. U so you + + align:start position:0% +for the software radio roughly. U so you + + + align:start position:0% +for the software radio roughly. U so you +create a box let's say a fur filter + + align:start position:0% +create a box let's say a fur filter + + + align:start position:0% +create a box let's say a fur filter +which processes elements of type float + + align:start position:0% +which processes elements of type float + + + align:start position:0% +which processes elements of type float +and then it takes in some arguments + + align:start position:0% +and then it takes in some arguments + + + align:start position:0% +and then it takes in some arguments +initialize the filters parameters and so + + align:start position:0% +initialize the filters parameters and so + + + align:start position:0% +initialize the filters parameters and so +on. You want to create a white noise + + align:start position:0% +on. You want to create a white noise + + + align:start position:0% +on. You want to create a white noise +generator and hook up the filter to the + + align:start position:0% +generator and hook up the filter to the + + + align:start position:0% +generator and hook up the filter to the +white noise generator. We use this to + + align:start position:0% +white noise generator. We use this to + + + align:start position:0% +white noise generator. We use this to +simulate a simple channel whis channel. + + align:start position:0% +simulate a simple channel whis channel. + + + align:start position:0% +simulate a simple channel whis channel. +So I'll just describe the components of + + align:start position:0% +So I'll just describe the components of + + + align:start position:0% +So I'll just describe the components of +our + + align:start position:0% +our + + + align:start position:0% +our +framework. Uh we have a lightweight + + align:start position:0% +framework. Uh we have a lightweight + + + align:start position:0% +framework. Uh we have a lightweight +scheduleuler on both the PPE as well as + + align:start position:0% +scheduleuler on both the PPE as well as + + + align:start position:0% +scheduleuler on both the PPE as well as +the + + align:start position:0% +the + + + align:start position:0% +the +SPEs. Uh right now it uses a static + + align:start position:0% +SPEs. Uh right now it uses a static + + + align:start position:0% +SPEs. Uh right now it uses a static +operator mapping in the sense that you + + align:start position:0% +operator mapping in the sense that you + + + align:start position:0% +operator mapping in the sense that you +have to specify a static configuration + + align:start position:0% +have to specify a static configuration + + + align:start position:0% +have to specify a static configuration +file where you say this operator name + + align:start position:0% +file where you say this operator name + + + align:start position:0% +file where you say this operator name +will run on this SP SPU number. But uh + + align:start position:0% +will run on this SP SPU number. But uh + + + align:start position:0% +will run on this SP SPU number. But uh +we've we've not completely implemented + + align:start position:0% +we've we've not completely implemented + + + align:start position:0% +we've we've not completely implemented +dynamically reconfiguring it at runtime + + align:start position:0% +dynamically reconfiguring it at runtime + + + align:start position:0% +dynamically reconfiguring it at runtime +and we haven't yet seen the need for + + align:start position:0% +and we haven't yet seen the need for + + + align:start position:0% +and we haven't yet seen the need for +doing that. So it it wouldn't be too + + align:start position:0% +doing that. So it it wouldn't be too + + + align:start position:0% +doing that. So it it wouldn't be too +hard to add if needed, but right now you + + align:start position:0% +hard to add if needed, but right now you + + + align:start position:0% +hard to add if needed, but right now you +can easily shuffle around the operator + + align:start position:0% +can easily shuffle around the operator + + + align:start position:0% +can easily shuffle around the operator +mapping by tweaking the configuration + + align:start position:0% +mapping by tweaking the configuration + + + align:start position:0% +mapping by tweaking the configuration +file. Signal blocks as I said were + + align:start position:0% +file. Signal blocks as I said were + + + align:start position:0% +file. Signal blocks as I said were +adapted from wave scope. Uh they use + + align:start position:0% +adapted from wave scope. Uh they use + + + align:start position:0% +adapted from wave scope. Uh they use +reference counting and avoid in-memory + + align:start position:0% +reference counting and avoid in-memory + + + align:start position:0% +reference counting and avoid in-memory +copies which can be quite expensive + + align:start position:0% +copies which can be quite expensive + + + align:start position:0% +copies which can be quite expensive +especially on the cell. Uh they also + + align:start position:0% +especially on the cell. Uh they also + + + align:start position:0% +especially on the cell. Uh they also +provide a convenient API to manipulate + + align:start position:0% +provide a convenient API to manipulate + + + align:start position:0% +provide a convenient API to manipulate +signals. So you don't have to do much of + + align:start position:0% +signals. So you don't have to do much of + + + align:start position:0% +signals. So you don't have to do much of +the memory management yourself or debug + + align:start position:0% +the memory management yourself or debug + + + align:start position:0% +the memory management yourself or debug +any of the hard problems to do with + + align:start position:0% +any of the hard problems to do with + + + align:start position:0% +any of the hard problems to do with +memory management. uh we also ported + + align:start position:0% +memory management. uh we also ported + + + align:start position:0% +memory management. uh we also ported +this library to ensure that data is + + align:start position:0% +this library to ensure that data is + + + align:start position:0% +this library to ensure that data is +aligned for you automatically and + + align:start position:0% +aligned for you automatically and + + + align:start position:0% +aligned for you automatically and +transported + + align:start position:0% +transported + + + align:start position:0% +transported +uh via cues. So one of the major things + + align:start position:0% +uh via cues. So one of the major things + + + align:start position:0% +uh via cues. So one of the major things +we had to implement was a queuing + + align:start position:0% +we had to implement was a queuing + + + align:start position:0% +we had to implement was a queuing +library and a remote heap management. + + align:start position:0% +library and a remote heap management. + + + align:start position:0% +library and a remote heap management. +What amounted essentially to a remote + + align:start position:0% +What amounted essentially to a remote + + + align:start position:0% +What amounted essentially to a remote +heap management library? So in some + + align:start position:0% +heap management library? So in some + + + align:start position:0% +heap management library? So in some +sense we faced a choice here. We could + + align:start position:0% +sense we faced a choice here. We could + + + align:start position:0% +sense we faced a choice here. We could +either have the PPE control and allocate + + align:start position:0% +either have the PPE control and allocate + + + align:start position:0% +either have the PPE control and allocate +memory statically and make all the + + align:start position:0% +memory statically and make all the + + + align:start position:0% +memory statically and make all the +decisions about what memory is allocated + + align:start position:0% +decisions about what memory is allocated + + + align:start position:0% +decisions about what memory is allocated +where or we could have the SPS manage it + + align:start position:0% +where or we could have the SPS manage it + + + align:start position:0% +where or we could have the SPS manage it +themselves. We decided to go for the + + align:start position:0% +themselves. We decided to go for the + + + align:start position:0% +themselves. We decided to go for the +latter uh partly because it was more + + align:start position:0% +latter uh partly because it was more + + + align:start position:0% +latter uh partly because it was more +dynamic and also because we weren't sure + + align:start position:0% +dynamic and also because we weren't sure + + + align:start position:0% +dynamic and also because we weren't sure +what the implications of all the control + + align:start position:0% +what the implications of all the control + + + align:start position:0% +what the implications of all the control +flow passing through the PPE were for + + align:start position:0% +flow passing through the PPE were for + + + align:start position:0% +flow passing through the PPE were for +this. So we chose the second approach + + align:start position:0% +this. So we chose the second approach + + + align:start position:0% +this. So we chose the second approach +which is autonomous memory management. + + align:start position:0% +which is autonomous memory management. + + + align:start position:0% +which is autonomous memory management. +So when an SP sends a streaming data + + align:start position:0% +So when an SP sends a streaming data + + + align:start position:0% +So when an SP sends a streaming data +element to another SP, it can it doesn't + + align:start position:0% +element to another SP, it can it doesn't + + + align:start position:0% +element to another SP, it can it doesn't +have to actually explicitly request the + + align:start position:0% +have to actually explicitly request the + + + align:start position:0% +have to actually explicitly request the +other SP for allocating memory. It has a + + align:start position:0% +other SP for allocating memory. It has a + + + align:start position:0% +other SP for allocating memory. It has a +remote heap interface so that it can + + align:start position:0% +remote heap interface so that it can + + + align:start position:0% +remote heap interface so that it can +directly allocate data and write to the + + align:start position:0% +directly allocate data and write to the + + + align:start position:0% +directly allocate data and write to the +SP. This is currently of fixed size. Um + + align:start position:0% +SP. This is currently of fixed size. Um + + + align:start position:0% +SP. This is currently of fixed size. Um +but it could be improved by using this + + align:start position:0% +but it could be improved by using this + + + align:start position:0% +but it could be improved by using this +heap to share a bunch of cues. Right now + + align:start position:0% +heap to share a bunch of cues. Right now + + + align:start position:0% +heap to share a bunch of cues. Right now +we have one remote heap for each que uh + + align:start position:0% +we have one remote heap for each que uh + + + align:start position:0% +we have one remote heap for each que uh +between operators on different SPEs. + + align:start position:0% +between operators on different SPEs. + + + align:start position:0% +between operators on different SPEs. +Uh so our system automatically handles + + align:start position:0% +Uh so our system automatically handles + + + align:start position:0% +Uh so our system automatically handles +pipelining and streaming data from SP to + + align:start position:0% +pipelining and streaming data from SP to + + + align:start position:0% +pipelining and streaming data from SP to +SP using the DMA + + align:start position:0% +SP using the DMA + + + align:start position:0% +SP using the DMA +API. So Micah will take over from here + + align:start position:0% +API. So Micah will take over from here + + + align:start position:0% +API. So Micah will take over from here +and describe the software radio + + align:start position:0% +and describe the software radio + + + align:start position:0% +and describe the software radio +implementation + + align:start position:0% + + + + align:start position:0% + +briefly. Either stay on the side where + + align:start position:0% +briefly. Either stay on the side where + + + align:start position:0% +briefly. Either stay on the side where +the phone is or move from + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +So, so our software radio implementation + + align:start position:0% +So, so our software radio implementation + + + align:start position:0% +So, so our software radio implementation +is is relatively simple. Um, we weren't + + align:start position:0% +is is relatively simple. Um, we weren't + + + align:start position:0% +is is relatively simple. Um, we weren't +we weren't pushing on that too hard, + + align:start position:0% +we weren't pushing on that too hard, + + + align:start position:0% +we weren't pushing on that too hard, +especially because it took the vast + + align:start position:0% +especially because it took the vast + + + align:start position:0% +especially because it took the vast +majority of our time just to get the + + align:start position:0% +majority of our time just to get the + + + align:start position:0% +majority of our time just to get the +framework to work. Um, saving the + + align:start position:0% +framework to work. Um, saving the + + + align:start position:0% +framework to work. Um, saving the +programmer trouble meant that we + + align:start position:0% +programmer trouble meant that we + + + align:start position:0% +programmer trouble meant that we +inherited a lot of trouble ourselves. + + align:start position:0% +inherited a lot of trouble ourselves. + + + align:start position:0% +inherited a lot of trouble ourselves. +So, + + align:start position:0% +So, + + + align:start position:0% +So, +um, it breaks down into about 25 boxes. + + align:start position:0% +um, it breaks down into about 25 boxes. + + + align:start position:0% +um, it breaks down into about 25 boxes. +um which which we took in our config + + align:start position:0% +um which which we took in our config + + + align:start position:0% +um which which we took in our config +file which is manually map mapped to + + align:start position:0% +file which is manually map mapped to + + + align:start position:0% +file which is manually map mapped to +mapped to the to the SPEs um about about + + align:start position:0% +mapped to the to the SPEs um about about + + + align:start position:0% +mapped to the to the SPEs um about about +3,000 lines of code most of which is + + align:start position:0% +3,000 lines of code most of which is + + + align:start position:0% +3,000 lines of code most of which is +most of which is framework + + align:start position:0% + + + + align:start position:0% + +um so I guess if it were to put together + + align:start position:0% +um so I guess if it were to put together + + + align:start position:0% +um so I guess if it were to put together +we'd have a nice diagram to show you I + + align:start position:0% +we'd have a nice diagram to show you I + + + align:start position:0% +we'd have a nice diagram to show you I +will there's enough time I'll try to + + align:start position:0% +will there's enough time I'll try to + + + align:start position:0% +will there's enough time I'll try to +draw a quick diagram on the chalkboard + + align:start position:0% +draw a quick diagram on the chalkboard + + + align:start position:0% +draw a quick diagram on the chalkboard +um so we're simul we're simulating both + + align:start position:0% +um so we're simul we're simulating both + + + align:start position:0% +um so we're simul we're simulating both +sender receiver and a channel. Um, + + align:start position:0% + + + + align:start position:0% + +so so that this is so the the the + + align:start position:0% +so so that this is so the the the + + + align:start position:0% +so so that this is so the the the +computation in question looks something + + align:start position:0% +computation in question looks something + + + align:start position:0% +computation in question looks something +like you have a a bit + + align:start position:0% +like you have a a bit + + + align:start position:0% +like you have a a bit +stream. You need to take these and + + align:start position:0% +stream. You need to take these and + + + align:start position:0% +stream. You need to take these and +convert them into some + + align:start position:0% +convert them into some + + + align:start position:0% +convert them into some +Can you can you read anything? Yeah. All + + align:start position:0% +Can you can you read anything? Yeah. All + + + align:start position:0% +Can you can you read anything? Yeah. All +right. + + align:start position:0% +right. + + + align:start position:0% +right. +All right. + + align:start position:0% + + + + align:start position:0% + +Lovely. All right. Um so you take stream + + align:start position:0% +Lovely. All right. Um so you take stream + + + align:start position:0% +Lovely. All right. Um so you take stream +of bits + + align:start position:0% + + + + align:start position:0% + +in. + + align:start position:0% +in. + + + align:start position:0% +in. +Um take bits um basically sort of sort + + align:start position:0% +Um take bits um basically sort of sort + + + align:start position:0% +Um take bits um basically sort of sort +of use a lookup mechanism to convert it + + align:start position:0% +of use a lookup mechanism to convert it + + + align:start position:0% +of use a lookup mechanism to convert it +to an analog waveform. Um and filter + + align:start position:0% +to an analog waveform. Um and filter + + + align:start position:0% +to an analog waveform. Um and filter +that to produce something that has a + + align:start position:0% +that to produce something that has a + + + align:start position:0% +that to produce something that has a +narrower + + align:start position:0% +narrower + + + align:start position:0% +narrower +spectrum. + + align:start position:0% +spectrum. + + + align:start position:0% +spectrum. +Um I'm running out of space here. Mix + + align:start position:0% +Um I'm running out of space here. Mix + + + align:start position:0% +Um I'm running out of space here. Mix +that multiply that against the sine + + align:start position:0% +that multiply that against the sine + + + align:start position:0% +that multiply that against the sine +wave modulation. Um and so you get you + + align:start position:0% +wave modulation. Um and so you get you + + + align:start position:0% +wave modulation. Um and so you get you +know you've probably seen pictures of + + align:start position:0% +know you've probably seen pictures of + + + align:start position:0% +know you've probably seen pictures of +this. It's um in it's very much like AM. + + align:start position:0% +this. It's um in it's very much like AM. + + + align:start position:0% +this. It's um in it's very much like AM. +It's basically binary AM is the scheme + + align:start position:0% +It's basically binary AM is the scheme + + + align:start position:0% +It's basically binary AM is the scheme +we use. It's one of the simplest things + + align:start position:0% +we use. It's one of the simplest things + + + align:start position:0% +we use. It's one of the simplest things +you can + + align:start position:0% + + + + align:start position:0% + +do. Okay. + + align:start position:0% +do. Okay. + + + align:start position:0% +do. Okay. +Um then this is sent to a simulated + + align:start position:0% +Um then this is sent to a simulated + + + align:start position:0% +Um then this is sent to a simulated +channel which is a random fur filter + + align:start position:0% +channel which is a random fur filter + + + align:start position:0% +channel which is a random fur filter +finite impulse response. So it's basic + + align:start position:0% +finite impulse response. So it's basic + + + align:start position:0% +finite impulse response. So it's basic +what that means is basically it's taking + + align:start position:0% +what that means is basically it's taking + + + align:start position:0% +what that means is basically it's taking +the copies of the input at different + + align:start position:0% +the copies of the input at different + + + align:start position:0% +the copies of the input at different +time offsets with random random + + align:start position:0% +time offsets with random random + + + align:start position:0% +time offsets with random random +coefficients and just summing them up. + + align:start position:0% +coefficients and just summing them up. + + + align:start position:0% +coefficients and just summing them up. +It's a huge multiply add multiply add + + align:start position:0% +It's a huge multiply add multiply add + + + align:start position:0% +It's a huge multiply add multiply add +combination. + + align:start position:0% +combination. + + + align:start position:0% +combination. +So 80 this is 80 + + align:start position:0% + + + + align:start position:0% + +taps and add some Gaussian + + align:start position:0% + + + + align:start position:0% + +noise. Um and then this we take over and + + align:start position:0% +noise. Um and then this we take over and + + + align:start position:0% +noise. Um and then this we take over and +then try to figure out what we put in in + + align:start position:0% +then try to figure out what we put in in + + + align:start position:0% +then try to figure out what we put in in +the first place. + + align:start position:0% +the first place. + + + align:start position:0% +the first place. +Um so a bunch of filtering + + align:start position:0% +Um so a bunch of filtering + + + align:start position:0% +Um so a bunch of filtering +uh again through more more finite + + align:start position:0% +uh again through more more finite + + + align:start position:0% +uh again through more more finite +impulse response filtering. Um, we have + + align:start position:0% +impulse response filtering. Um, we have + + + align:start position:0% +impulse response filtering. Um, we have +to there's a little a closed loop that + + align:start position:0% +to there's a little a closed loop that + + + align:start position:0% +to there's a little a closed loop that +tries to estimate the signal amplitude + + align:start position:0% +tries to estimate the signal amplitude + + + align:start position:0% +tries to estimate the signal amplitude +and correct for it. That's called + + align:start position:0% +and correct for it. That's called + + + align:start position:0% +and correct for it. That's called +automatic gain control to sort of keep + + align:start position:0% +automatic gain control to sort of keep + + + align:start position:0% +automatic gain control to sort of keep +it constant. + + align:start position:0% +it constant. + + + align:start position:0% +it constant. +Um, and I'm probably getting things + + align:start position:0% +Um, and I'm probably getting things + + + align:start position:0% +Um, and I'm probably getting things +these things a little out of order. + + align:start position:0% +these things a little out of order. + + + align:start position:0% +these things a little out of order. +Um, we we square the signal to we this + + align:start position:0% +Um, we we square the signal to we this + + + align:start position:0% +Um, we we square the signal to we this +is the incoherent de modulation part. We + + align:start position:0% +is the incoherent de modulation part. We + + + align:start position:0% +is the incoherent de modulation part. We +square the signal to get rid of the + + align:start position:0% +square the signal to get rid of the + + + align:start position:0% +square the signal to get rid of the +carrier. + + align:start position:0% +carrier. + + + align:start position:0% +carrier. +Um, automated gain control + + align:start position:0% +Um, automated gain control + + + align:start position:0% +Um, automated gain control +filtering. There's another loop. Um, + + align:start position:0% +filtering. There's another loop. Um, + + + align:start position:0% +filtering. There's another loop. Um, +this is called a phase lock loop. The + + align:start position:0% +this is called a phase lock loop. The + + + align:start position:0% +this is called a phase lock loop. The +idea is try to match a sine wave to some + + align:start position:0% +idea is try to match a sine wave to some + + + align:start position:0% +idea is try to match a sine wave to some +to some to some input signal. Um, so I + + align:start position:0% +to some to some input signal. Um, so I + + + align:start position:0% +to some to some input signal. Um, so I +don't explain it very well. Um, it's + + align:start position:0% +don't explain it very well. Um, it's + + + align:start position:0% +don't explain it very well. Um, it's +basically a lock in type of detector. + + align:start position:0% +basically a lock in type of detector. + + + align:start position:0% +basically a lock in type of detector. +The idea is to lock into the phase of + + align:start position:0% +The idea is to lock into the phase of + + + align:start position:0% +The idea is to lock into the phase of +some periodic thing. This is for + + align:start position:0% +some periodic thing. This is for + + + align:start position:0% +some periodic thing. This is for +recovering when do you sample? Because + + align:start position:0% +recovering when do you sample? Because + + + align:start position:0% +recovering when do you sample? Because +you've got this messy waveform. You got + + align:start position:0% +you've got this messy waveform. You got + + + align:start position:0% +you've got this messy waveform. You got +to know when when to look and say, okay, + + align:start position:0% +to know when when to look and say, okay, + + + align:start position:0% +to know when when to look and say, okay, +is it high? Is it low to get a bit out? + + align:start position:0% +is it high? Is it low to get a bit out? + + + align:start position:0% +is it high? Is it low to get a bit out? +Yeah, that's I think that gives the + + align:start position:0% +Yeah, that's I think that gives the + + + align:start position:0% +Yeah, that's I think that gives the +picture. I'm probably boring everybody. + + align:start position:0% +picture. I'm probably boring everybody. + + + align:start position:0% +picture. I'm probably boring everybody. +So, here's a picture. Here's a picture + + align:start position:0% +So, here's a picture. Here's a picture + + + align:start position:0% +So, here's a picture. Here's a picture +generated from the system. Um the red + + align:start position:0% +generated from the system. Um the red + + + align:start position:0% +generated from the system. Um the red +line So, the green line is the data in + + align:start position:0% +line So, the green line is the data in + + + align:start position:0% +line So, the green line is the data in +um you know, high low one. Uh the red + + align:start position:0% +um you know, high low one. Uh the red + + + align:start position:0% +um you know, high low one. Uh the red +line is the analog signal out right + + align:start position:0% +line is the analog signal out right + + + align:start position:0% +line is the analog signal out right +before it's supposed to decide what the + + align:start position:0% +before it's supposed to decide what the + + + align:start position:0% +before it's supposed to decide what the +heck the input was. So, this is after + + align:start position:0% +heck the input was. So, this is after + + + align:start position:0% +heck the input was. So, this is after +this is after um this is after squaring + + align:start position:0% +this is after um this is after squaring + + + align:start position:0% +this is after um this is after squaring +and filtering and automatic gain control + + align:start position:0% +and filtering and automatic gain control + + + align:start position:0% +and filtering and automatic gain control +and all that. Um the little blips um are + + align:start position:0% +and all that. Um the little blips um are + + + align:start position:0% +and all that. Um the little blips um are +actually because we used we used a + + align:start position:0% +actually because we used we used a + + + align:start position:0% +actually because we used we used a +modulation called alternate mark + + align:start position:0% +modulation called alternate mark + + + align:start position:0% +modulation called alternate mark +inversion. It just basically flips every + + align:start position:0% +inversion. It just basically flips every + + + align:start position:0% +inversion. It just basically flips every +one. That's why it's blipping instead of + + align:start position:0% +one. That's why it's blipping instead of + + + align:start position:0% +one. That's why it's blipping instead of +being constant. It's just a convenient + + align:start position:0% +being constant. It's just a convenient + + + align:start position:0% +being constant. It's just a convenient +trick. And then the little blue daggers + + align:start position:0% +trick. And then the little blue daggers + + + align:start position:0% +trick. And then the little blue daggers +are the results of the phase lock loop + + align:start position:0% +are the results of the phase lock loop + + + align:start position:0% +are the results of the phase lock loop +to try and recover when to sample. + + align:start position:0% +to try and recover when to sample. + + + align:start position:0% +to try and recover when to sample. +They're kind of off, but they're kind of + + align:start position:0% +They're kind of off, but they're kind of + + + align:start position:0% +They're kind of off, but they're kind of +right. And so if you take the little + + align:start position:0% +right. And so if you take the little + + + align:start position:0% +right. And so if you take the little +blue blue blip, if the red line is above + + align:start position:0% +blue blue blip, if the red line is above + + + align:start position:0% +blue blue blip, if the red line is above +zero, it's a one. And if it's below + + align:start position:0% +zero, it's a one. And if it's below + + + align:start position:0% +zero, it's a one. And if it's below +zero, it's a zero. Um + + align:start position:0% +zero, it's a zero. Um + + + align:start position:0% +zero, it's a zero. Um +And that's how you get your bits + + align:start position:0% +And that's how you get your bits + + + align:start position:0% +And that's how you get your bits +out. + + align:start position:0% + + + + align:start position:0% + +Um, + + align:start position:0% +Um, + + + align:start position:0% +Um, +so this was hard to get + + align:start position:0% +so this was hard to get + + + align:start position:0% +so this was hard to get +right mostly because of the framework + + align:start position:0% +right mostly because of the framework + + + align:start position:0% +right mostly because of the framework +issues. + + align:start position:0% +issues. + + + align:start position:0% +issues. +Um so we you know implementing + + align:start position:0% +Um so we you know implementing + + + align:start position:0% +Um so we you know implementing +implementing distributed objects on a + + align:start position:0% +implementing distributed objects on a + + + align:start position:0% +implementing distributed objects on a +system without real shared memory um is + + align:start position:0% +system without real shared memory um is + + + align:start position:0% +system without real shared memory um is +hard because you have to serialize + + align:start position:0% +hard because you have to serialize + + + align:start position:0% +hard because you have to serialize +everything into a stream of bits and + + align:start position:0% +everything into a stream of bits and + + + align:start position:0% +everything into a stream of bits and +deserialize. + + align:start position:0% +deserialize. + + + align:start position:0% +deserialize. +Um so it really makes pi out of any + + align:start position:0% +Um so it really makes pi out of any + + + align:start position:0% +Um so it really makes pi out of any +existing object-oriented code. Um we we + + align:start position:0% +existing object-oriented code. Um we we + + + align:start position:0% +existing object-oriented code. Um we we +did quite a bit of work to get um to get + + align:start position:0% +did quite a bit of work to get um to get + + + align:start position:0% +did quite a bit of work to get um to get +sort of decent lock free almost zero + + align:start position:0% +sort of decent lock free almost zero + + + align:start position:0% +sort of decent lock free almost zero +copy. Another day or so we probably + + align:start position:0% +copy. Another day or so we probably + + + align:start position:0% +copy. Another day or so we probably +would have gotten zero copy. um transfer + + align:start position:0% +would have gotten zero copy. um transfer + + + align:start position:0% +would have gotten zero copy. um transfer +transfer streaming of the data from + + align:start position:0% +transfer streaming of the data from + + + align:start position:0% +transfer streaming of the data from +place to place. Um and we had to keep + + align:start position:0% +place to place. Um and we had to keep + + + align:start position:0% +place to place. Um and we had to keep +the code footprint low. + + align:start position:0% +the code footprint low. + + + align:start position:0% +the code footprint low. +Um C++ is bloated. Uh we don't have an + + align:start position:0% +Um C++ is bloated. Uh we don't have an + + + align:start position:0% +Um C++ is bloated. Uh we don't have an +overlay system yet to sort of you know + + align:start position:0% +overlay system yet to sort of you know + + + align:start position:0% +overlay system yet to sort of you know +if if a SPE is not running a particular + + align:start position:0% +if if a SPE is not running a particular + + + align:start position:0% +if if a SPE is not running a particular +box. It still has to have the code for + + align:start position:0% +box. It still has to have the code for + + + align:start position:0% +box. It still has to have the code for +it because we don't have you know we + + align:start position:0% +it because we don't have you know we + + + align:start position:0% +it because we don't have you know we +don't have any infrastructure for some + + align:start position:0% +don't have any infrastructure for some + + + align:start position:0% +don't have any infrastructure for some +that yeah it's pretty messy. So all the + + align:start position:0% +that yeah it's pretty messy. So all the + + + align:start position:0% +that yeah it's pretty messy. So all the +code is on all the SPDs. Um so code + + align:start position:0% +code is on all the SPDs. Um so code + + + align:start position:0% +code is on all the SPDs. Um so code +bloat is particular issue and XLC has + + align:start position:0% +bloat is particular issue and XLC has + + + align:start position:0% +bloat is particular issue and XLC has +this particular penchant for runtime + + align:start position:0% +this particular penchant for runtime + + + align:start position:0% +this particular penchant for runtime +type information and exception handling. + + align:start position:0% +type information and exception handling. + + + align:start position:0% +type information and exception handling. +Um incredible amount of voodoo is + + align:start position:0% +Um incredible amount of voodoo is + + + align:start position:0% +Um incredible amount of voodoo is +necessary to get them out to get them + + align:start position:0% +necessary to get them out to get them + + + align:start position:0% +necessary to get them out to get them +and that 70k of useless bloat out of + + align:start position:0% +and that 70k of useless bloat out of + + + align:start position:0% +and that 70k of useless bloat out of +there. + + align:start position:0% +there. + + + align:start position:0% +there. +Um but but we pretty much have the it + + align:start position:0% +Um but but we pretty much have the it + + + align:start position:0% +Um but but we pretty much have the it +works but not always. So we did manage + + align:start position:0% +works but not always. So we did manage + + + align:start position:0% +works but not always. So we did manage +to get it running long enough to make + + align:start position:0% +to get it running long enough to make + + + align:start position:0% +to get it running long enough to make +some measurements. But yeah, we did get + + align:start position:0% +some measurements. But yeah, we did get + + + align:start position:0% +some measurements. But yeah, we did get +we did get some decent data out. Um + + align:start position:0% +we did get some decent data out. Um + + + align:start position:0% +we did get some decent data out. Um +running on the PPU only we can run about + + align:start position:0% +running on the PPU only we can run about + + + align:start position:0% +running on the PPU only we can run about +170,000 samples per second through um + + align:start position:0% +170,000 samples per second through um + + + align:start position:0% +170,000 samples per second through um +and by with the scheduling file that + + align:start position:0% +and by with the scheduling file that + + + align:start position:0% +and by with the scheduling file that +sort of kind of rule of thumb we just + + align:start position:0% +sort of kind of rule of thumb we just + + + align:start position:0% +sort of kind of rule of thumb we just +sort of roughly said okay that looks + + align:start position:0% +sort of roughly said okay that looks + + + align:start position:0% +sort of roughly said okay that looks +about this big we'll throw it on this + + align:start position:0% +about this big we'll throw it on this + + + align:start position:0% +about this big we'll throw it on this +SP. + + align:start position:0% +SP. + + + align:start position:0% +SP. +We got roughly four times that using + + align:start position:0% +We got roughly four times that using + + + align:start position:0% +We got roughly four times that using +five SPEs. The post is a little large + + align:start position:0% +five SPEs. The post is a little large + + + align:start position:0% +five SPEs. The post is a little large +but + + align:start position:0% +but + + + align:start position:0% +but +Um, yeah, we're we we had to really had + + align:start position:0% +Um, yeah, we're we we had to really had + + + align:start position:0% +Um, yeah, we're we we had to really had +to push down things like our Q. We we + + align:start position:0% +to push down things like our Q. We we + + + align:start position:0% +to push down things like our Q. We we +just didn't have enough memory. It + + align:start position:0% +just didn't have enough memory. It + + + align:start position:0% +just didn't have enough memory. It +sucked. Um, + + align:start position:0% + + + + align:start position:0% + +yeah, basically just said that + + align:start position:0% +yeah, basically just said that + + + align:start position:0% +yeah, basically just said that +performance, I guess. Um, so interesting + + align:start position:0% +performance, I guess. Um, so interesting + + + align:start position:0% +performance, I guess. Um, so interesting +interesting performance behavior. We + + align:start position:0% +interesting performance behavior. We + + + align:start position:0% +interesting performance behavior. We +found that the SPEs are ridiculously + + align:start position:0% +found that the SPEs are ridiculously + + + align:start position:0% +found that the SPEs are ridiculously +underutilized. Um, there may be most of + + align:start position:0% +underutilized. Um, there may be most of + + + align:start position:0% +underutilized. Um, there may be most of +the algorithms are quite a bit zippier + + align:start position:0% +the algorithms are quite a bit zippier + + + align:start position:0% +the algorithms are quite a bit zippier +on the SPEs. Um and so you know they're + + align:start position:0% +on the SPEs. Um and so you know they're + + + align:start position:0% +on the SPEs. Um and so you know they're +maybe running about a third of the time + + align:start position:0% +maybe running about a third of the time + + + align:start position:0% +maybe running about a third of the time +or and the rest of the time just waiting + + align:start position:0% +or and the rest of the time just waiting + + + align:start position:0% +or and the rest of the time just waiting +for input and then the PPE um which is + + align:start position:0% +for input and then the PPE um which is + + + align:start position:0% +for input and then the PPE um which is +doing only a tiny amount of the + + align:start position:0% +doing only a tiny amount of the + + + align:start position:0% +doing only a tiny amount of the +computation basically just feeding in + + align:start position:0% +computation basically just feeding in + + + align:start position:0% +computation basically just feeding in +and sucking it out is spending half of + + align:start position:0% +and sucking it out is spending half of + + + align:start position:0% +and sucking it out is spending half of +its time all busy and the other half of + + align:start position:0% +its time all busy and the other half of + + + align:start position:0% +its time all busy and the other half of +the time stuck in flow control um + + align:start position:0% +the time stuck in flow control um + + + align:start position:0% +the time stuck in flow control um +waiting for Q space which + + align:start position:0% +waiting for Q space which + + + align:start position:0% +waiting for Q space which +is we our flow control algorithm sucks + + align:start position:0% +is we our flow control algorithm sucks + + + align:start position:0% +is we our flow control algorithm sucks +and better with time but so but it seems + + align:start position:0% +and better with time but so but it seems + + + align:start position:0% +and better with time but so but it seems +like you should be able to quite a bit + + align:start position:0% +like you should be able to quite a bit + + + align:start position:0% +like you should be able to quite a bit +better than we did um with a bit more + + align:start position:0% +better than we did um with a bit more + + + align:start position:0% +better than we did um with a bit more +work. Um I + + align:start position:0% +work. Um I + + + align:start position:0% +work. Um I +guess + + align:start position:0% +guess + + + align:start position:0% +guess +so we need to cut down on the code + + align:start position:0% +so we need to cut down on the code + + + align:start position:0% +so we need to cut down on the code +footprint. Um and once we have a little + + align:start position:0% +footprint. Um and once we have a little + + + align:start position:0% +footprint. Um and once we have a little +bit of breathing room, we can and get + + align:start position:0% +bit of breathing room, we can and get + + + align:start position:0% +bit of breathing room, we can and get +rid of the nasty race bugs and such. We + + align:start position:0% +rid of the nasty race bugs and such. We + + + align:start position:0% +rid of the nasty race bugs and such. We +can finally investigate what was our + + align:start position:0% +can finally investigate what was our + + + align:start position:0% +can finally investigate what was our +sort of original pie in the sky goal of + + align:start position:0% +sort of original pie in the sky goal of + + + align:start position:0% +sort of original pie in the sky goal of +automatically deciding what goes where. + + align:start position:0% +automatically deciding what goes where. + + + align:start position:0% +automatically deciding what goes where. +um you know doing me taking measurements + + align:start position:0% +um you know doing me taking measurements + + + align:start position:0% +um you know doing me taking measurements +of the performance and then feeding that + + align:start position:0% +of the performance and then feeding that + + + align:start position:0% +of the performance and then feeding that +back into to producing a better + + align:start position:0% +back into to producing a better + + + align:start position:0% +back into to producing a better +placement of operators + + align:start position:0% +placement of operators + + + align:start position:0% +placement of operators +um and uh applying data parallelism by + + align:start position:0% +um and uh applying data parallelism by + + + align:start position:0% +um and uh applying data parallelism by +instantiating operators on multiple SP + + align:start position:0% +instantiating operators on multiple SP + + + align:start position:0% +instantiating operators on multiple SP +multiple different SPEs and splitting + + align:start position:0% +multiple different SPEs and splitting + + + align:start position:0% +multiple different SPEs and splitting +the data stream + + align:start position:0% +the data stream + + + align:start position:0% +the data stream +um and just doing more. So + + align:start position:0% + + + + align:start position:0% + +since your PB is only at 40% + + align:start position:0% +since your PB is only at 40% + + + align:start position:0% +since your PB is only at 40% +utilization, could you put actual work + + align:start position:0% +utilization, could you put actual work + + + align:start position:0% +utilization, could you put actual work +on there? We did put some work on there. + + align:start position:0% +on there? We did put some work on there. + + + align:start position:0% +on there? We did put some work on there. +Actually, we put work on there because + + align:start position:0% +Actually, we put work on there because + + + align:start position:0% +Actually, we put work on there because +we couldn't fit all the boxes, the code + + align:start position:0% +we couldn't fit all the boxes, the code + + + align:start position:0% +we couldn't fit all the boxes, the code +for all the boxes into the SPES. So we + + align:start position:0% +for all the boxes into the SPES. So we + + + align:start position:0% +for all the boxes into the SPES. So we +we sort of strategically put a few + + align:start position:0% +we sort of strategically put a few + + + align:start position:0% +we sort of strategically put a few +things at the beginning, a few things at + + align:start position:0% +things at the beginning, a few things at + + + align:start position:0% +things at the beginning, a few things at +the end, which weren't supposed to be + + align:start position:0% +the end, which weren't supposed to be + + + align:start position:0% +the end, which weren't supposed to be +very computationally intensive, and yet + + align:start position:0% +very computationally intensive, and yet + + + align:start position:0% +very computationally intensive, and yet +they managed to take up half the CPU. + + align:start position:0% +they managed to take up half the CPU. + + + align:start position:0% +they managed to take up half the CPU. +Now the issue the issue with the other + + align:start position:0% +Now the issue the issue with the other + + + align:start position:0% +Now the issue the issue with the other +half of the CPU is that it's actually in + + align:start position:0% +half of the CPU is that it's actually in + + + align:start position:0% +half of the CPU is that it's actually in +inside an inner loop deep recursive in + + align:start position:0% +inside an inner loop deep recursive in + + + align:start position:0% +inside an inner loop deep recursive in +blocking because basically our back + + align:start position:0% +blocking because basically our back + + + align:start position:0% +blocking because basically our back +pressure isn't online yet. So if it if + + align:start position:0% +pressure isn't online yet. So if it if + + + align:start position:0% +pressure isn't online yet. So if it if +if it tries to emit something to a queue + + align:start position:0% +if it tries to emit something to a queue + + + align:start position:0% +if it tries to emit something to a queue +and that queue is full just stops and it + + align:start position:0% +and that queue is full just stops and it + + + align:start position:0% +and that queue is full just stops and it +really could be running a whole bunch of + + align:start position:0% +really could be running a whole bunch of + + + align:start position:0% +really could be running a whole bunch of +other stuff but it's not smart enough to + + align:start position:0% +other stuff but it's not smart enough to + + + align:start position:0% +other stuff but it's not smart enough to +do that yet. + + align:start position:0% + + + + align:start position:0% + +Everything being everything being unlike + + align:start position:0% +Everything being everything being unlike + + + align:start position:0% +Everything being everything being unlike +sort of a model like stream it + + align:start position:0% +sort of a model like stream it + + + align:start position:0% +sort of a model like stream it +everything here is sort of asynchronous + + align:start position:0% +everything here is sort of asynchronous + + + align:start position:0% +everything here is sort of asynchronous +and code driven or sort of the SPs they + + align:start position:0% +and code driven or sort of the SPs they + + + align:start position:0% +and code driven or sort of the SPs they +can decide on the fly how much to emit + + align:start position:0% +can decide on the fly how much to emit + + + align:start position:0% +can decide on the fly how much to emit +um the programmer doesn't have to + + align:start position:0% +um the programmer doesn't have to + + + align:start position:0% +um the programmer doesn't have to +declare anything but it means everything + + align:start position:0% +declare anything but it means everything + + + align:start position:0% +declare anything but it means everything +is asynchronous um and so you can raise + + align:start position:0% +is asynchronous um and so you can raise + + + align:start position:0% +is asynchronous um and so you can raise +the issues or but in this application do + + align:start position:0% +the issues or but in this application do + + + align:start position:0% +the issues or but in this application do +you find any dynamic rates in this + + align:start position:0% +you find any dynamic rates in this + + + align:start position:0% +you find any dynamic rates in this +application there's not much it's a very + + align:start position:0% +application there's not much it's a very + + + align:start position:0% +application there's not much it's a very +simple application if we actually went + + align:start position:0% +simple application if we actually went + + + align:start position:0% +simple application if we actually went +to packetization + + align:start position:0% +to packetization + + + align:start position:0% +to packetization +um error correction, compression, things + + align:start position:0% +um error correction, compression, things + + + align:start position:0% +um error correction, compression, things +like that. Probably see a lot more of + + align:start position:0% +like that. Probably see a lot more of + + + align:start position:0% +like that. Probably see a lot more of +that. But yeah, this this is definitely + + align:start position:0% +that. But yeah, this this is definitely + + + align:start position:0% +that. But yeah, this this is definitely +underutilized in sort of the synchronous + + align:start position:0% +underutilized in sort of the synchronous + + + align:start position:0% +underutilized in sort of the synchronous +capabilities of the system. + + align:start position:0% +capabilities of the system. + + + align:start position:0% +capabilities of the system. +In the case of radio, wouldn't it be + + align:start position:0% +In the case of radio, wouldn't it be + + + align:start position:0% +In the case of radio, wouldn't it be +okay to drop maybe a frame or two of + + align:start position:0% +okay to drop maybe a frame or two of + + + align:start position:0% +okay to drop maybe a frame or two of +audio data just because you you know + + align:start position:0% +audio data just because you you know + + + align:start position:0% +audio data just because you you know +you're spending so much time waiting? + + align:start position:0% +you're spending so much time waiting? + + + align:start position:0% +you're spending so much time waiting? +It'd be better just, you know, relieve + + align:start position:0% +It'd be better just, you know, relieve + + + align:start position:0% +It'd be better just, you know, relieve +the pressure on the cues by just + + align:start position:0% +the pressure on the cues by just + + + align:start position:0% +the pressure on the cues by just +dropping some frames that are necessary + + align:start position:0% +dropping some frames that are necessary + + + align:start position:0% +dropping some frames that are necessary +interpolating it in the end. try to fix + + align:start position:0% +interpolating it in the end. try to fix + + + align:start position:0% +interpolating it in the end. try to fix +it up. It might well be. We decided not + + align:start position:0% +it up. It might well be. We decided not + + + align:start position:0% +it up. It might well be. We decided not +to do that as a part of the framework um + + align:start position:0% +to do that as a part of the framework um + + + align:start position:0% +to do that as a part of the framework um +because of a policy decision and we + + align:start position:0% +because of a policy decision and we + + + align:start position:0% +because of a policy decision and we +didn't want to make that for all + + align:start position:0% +didn't want to make that for all + + + align:start position:0% +didn't want to make that for all +possible applications. But if you figure + + align:start position:0% +possible applications. But if you figure + + + align:start position:0% +possible applications. But if you figure +out a good way to expose that, that + + align:start position:0% +out a good way to expose that, that + + + align:start position:0% +out a good way to expose that, that +definitely would be an option. Just drop + + align:start position:0% +definitely would be an option. Just drop + + + align:start position:0% +definitely would be an option. Just drop +a few packets, drop a few samples. Yeah. + + align:start position:0% +a few packets, drop a few samples. Yeah. + + + align:start position:0% +a few packets, drop a few samples. Yeah. +So, what about buffer sizes? You declare + + align:start position:0% +So, what about buffer sizes? You declare + + + align:start position:0% +So, what about buffer sizes? You declare +the buffer size as well? Uh yeah. Well, + + align:start position:0% +the buffer size as well? Uh yeah. Well, + + + align:start position:0% +the buffer size as well? Uh yeah. Well, +the way we have it now is actually + + align:start position:0% +the way we have it now is actually + + + align:start position:0% +the way we have it now is actually +there's just a pound defined info that + + align:start position:0% +there's just a pound defined info that + + + align:start position:0% +there's just a pound defined info that +says all buffers are this size. Okay. + + align:start position:0% +says all buffers are this size. Okay. + + + align:start position:0% +says all buffers are this size. Okay. +any double buffering in there or uh you + + align:start position:0% +any double buffering in there or uh you + + + align:start position:0% +any double buffering in there or uh you +don't need it. Well, actually the way it + + align:start position:0% +don't need it. Well, actually the way it + + + align:start position:0% +don't need it. Well, actually the way it +works is that there's there's this sort + + align:start position:0% +works is that there's there's this sort + + + align:start position:0% +works is that there's there's this sort +of this remote heap input Q and an + + align:start position:0% +of this remote heap input Q and an + + + align:start position:0% +of this remote heap input Q and an +upstream SP just DMAS things in as it + + align:start position:0% +upstream SP just DMAS things in as it + + + align:start position:0% +upstream SP just DMAS things in as it +feels like and then the the downstream + + align:start position:0% +feels like and then the the downstream + + + align:start position:0% +feels like and then the the downstream +SP looks is is there something here? + + align:start position:0% +SP looks is is there something here? + + + align:start position:0% +SP looks is is there something here? +Grab it, use it. So it it just it just + + align:start position:0% +Grab it, use it. So it it just it just + + + align:start position:0% +Grab it, use it. So it it just it just +it just sort of works however much + + align:start position:0% +it just sort of works however much + + + align:start position:0% +it just sort of works however much +buffering there's buffer and sort of + + align:start position:0% +buffering there's buffer and sort of + + + align:start position:0% +buffering there's buffer and sort of +manage to get that lock free. Yeah. + + align:start position:0% +manage to get that lock free. Yeah. + + + align:start position:0% +manage to get that lock free. Yeah. +Yeah. So that's that's that's an that's + + align:start position:0% +Yeah. So that's that's that's an that's + + + align:start position:0% +Yeah. So that's that's that's an that's +a benefit of the asynchronous approach. + + align:start position:0% +a benefit of the asynchronous approach. + + + align:start position:0% +a benefit of the asynchronous approach. +It just sort of works if you have enough + + align:start position:0% +It just sort of works if you have enough + + + align:start position:0% +It just sort of works if you have enough +memory, which we don't. + + align:start position:0% + + + + align:start position:0% + +Your cues are tiny. + + align:start position:0% + + + + align:start position:0% + +Any other questions? Mom's angrily + + align:start position:0% +Any other questions? Mom's angrily + + + align:start position:0% +Any other questions? Mom's angrily +telling me that his connection dropped, + + align:start position:0% +telling me that his connection dropped, + + + align:start position:0% +telling me that his connection dropped, +but he's not the + + align:start position:0% + + + + align:start position:0% + +Yeah, I I see it. + + align:start position:0% + + + + align:start position:0% + +How do you do that? + + align:start position:0% +How do you do that? + + + align:start position:0% +How do you do that? +Yeah. Hold on. Just + + align:start position:0% + + + + align:start position:0% + +any other questions. + + align:start position:0% + + + + align:start position:0% + +Did you want to do the demo? + + align:start position:0% + + + + align:start position:0% + +Uh what did you do to get + + align:start position:0% +Uh what did you do to get + + + align:start position:0% +Uh what did you do to get +How did we manage to get ourselves race + + align:start position:0% +How did we manage to get ourselves race + + + align:start position:0% +How did we manage to get ourselves race +conditions? + + align:start position:0% +conditions? + + + align:start position:0% +conditions? +Um well it's a mix of the fact that all + + align:start position:0% +Um well it's a mix of the fact that all + + + align:start position:0% +Um well it's a mix of the fact that all +the SPUs can essentially operate as + + align:start position:0% +the SPUs can essentially operate as + + + align:start position:0% +the SPUs can essentially operate as +independent threads and are sort of + + align:start position:0% +independent threads and are sort of + + + align:start position:0% +independent threads and are sort of +asynchronously dmaing things to each + + align:start position:0% +asynchronously dmaing things to each + + + align:start position:0% +asynchronously dmaing things to each +other and some somewhat poor arch you + + align:start position:0% +other and some somewhat poor arch you + + + align:start position:0% +other and some somewhat poor arch you +know sort of legacy driven architectural + + align:start position:0% +know sort of legacy driven architectural + + + align:start position:0% +know sort of legacy driven architectural +decisions on the way the ppu code works + + align:start position:0% +decisions on the way the ppu code works + + + align:start position:0% +decisions on the way the ppu code works +um because we we ported a lot of code + + align:start position:0% +um because we we ported a lot of code + + + align:start position:0% +um because we we ported a lot of code +from the wave scope platform wasn't + + align:start position:0% +from the wave scope platform wasn't + + + align:start position:0% +from the wave scope platform wasn't +fairly well backed yeah and and that was + + align:start position:0% +fairly well backed yeah and and that was + + + align:start position:0% +fairly well backed yeah and and that was +intended to be multi-threaded with + + align:start position:0% +intended to be multi-threaded with + + + align:start position:0% +intended to be multi-threaded with +pthreads which you know in our in our + + align:start position:0% +pthreads which you know in our in our + + + align:start position:0% +pthreads which you know in our in our +original naive before we actually + + align:start position:0% +original naive before we actually + + + align:start position:0% +original naive before we actually +started the class um impression, we + + align:start position:0% +started the class um impression, we + + + align:start position:0% +started the class um impression, we +thought we were just going to port the + + align:start position:0% +thought we were just going to port the + + + align:start position:0% +thought we were just going to port the +whole thing and use Bthreads on the + + align:start position:0% +whole thing and use Bthreads on the + + + align:start position:0% +whole thing and use Bthreads on the +cell, which of course is not possible. + + align:start position:0% +cell, which of course is not possible. + + + align:start position:0% +cell, which of course is not possible. +Um so there were some still some + + align:start position:0% +Um so there were some still some + + + align:start position:0% +Um so there were some still some +threaded components in there. Um and we + + align:start position:0% +threaded components in there. Um and we + + + align:start position:0% +threaded components in there. Um and we +introduced a lot of bugs trying to port + + align:start position:0% +introduced a lot of bugs trying to port + + + align:start position:0% +introduced a lot of bugs trying to port +the thing. + + align:start position:0% +the thing. + + + align:start position:0% +the thing. +Um see if I can see another subtle + + align:start position:0% +Um see if I can see another subtle + + + align:start position:0% +Um see if I can see another subtle +surprising thing was the fact that we + + align:start position:0% +surprising thing was the fact that we + + + align:start position:0% +surprising thing was the fact that we +had to replace array constructors in + + align:start position:0% +had to replace array constructors in + + + align:start position:0% +had to replace array constructors in +order to eliminate RTI and it was just a + + align:start position:0% +order to eliminate RTI and it was just a + + + align:start position:0% +order to eliminate RTI and it was just a +big deal. We had to get rid of new, we + + align:start position:0% +big deal. We had to get rid of new, we + + + align:start position:0% +big deal. We had to get rid of new, we +had to get rid of delete, we had to get + + align:start position:0% +had to get rid of delete, we had to get + + + align:start position:0% +had to get rid of delete, we had to get +rid of array constructors, we had to get + + align:start position:0% +rid of array constructors, we had to get + + + align:start position:0% +rid of array constructors, we had to get +rid of pure vual functions and virtual + + align:start position:0% +rid of pure vual functions and virtual + + + align:start position:0% +rid of pure vual functions and virtual +destructors. It was a mess. But I guess + + align:start position:0% +destructors. It was a mess. But I guess + + + align:start position:0% +destructors. It was a mess. But I guess +one I guess there's one more piffy thing + + align:start position:0% +one I guess there's one more piffy thing + + + align:start position:0% +one I guess there's one more piffy thing +I can say about race conditions is um + + align:start position:0% +I can say about race conditions is um + + + align:start position:0% +I can say about race conditions is um +it's incredible how many subtle race + + align:start position:0% +it's incredible how many subtle race + + + align:start position:0% +it's incredible how many subtle race +conditions and bugs we found in the + + align:start position:0% +conditions and bugs we found in the + + + align:start position:0% +conditions and bugs we found in the +queueing the remote heap and queuing + + align:start position:0% +queueing the remote heap and queuing + + + align:start position:0% +queueing the remote heap and queuing +library. Um because there's one one it's + + align:start position:0% +library. Um because there's one one it's + + + align:start position:0% +library. Um because there's one one it's +it's a log free it's a log free + + align:start position:0% +it's a log free it's a log free + + + align:start position:0% +it's a log free it's a log free +asynchronous data structure. um there + + align:start position:0% +asynchronous data structure. um there + + + align:start position:0% +asynchronous data structure. um there +are two two threads but two two SPUs + + align:start position:0% +are two two threads but two two SPUs + + + align:start position:0% +are two two threads but two two SPUs +reading and writing from it at the same + + align:start position:0% +reading and writing from it at the same + + + align:start position:0% +reading and writing from it at the same +time and there's all sorts of little + + align:start position:0% +time and there's all sorts of little + + + align:start position:0% +time and there's all sorts of little +subtleties where if you get it a little + + align:start position:0% +subtleties where if you get it a little + + + align:start position:0% +subtleties where if you get it a little +bit wrong you end up with one of the Q + + align:start position:0% +bit wrong you end up with one of the Q + + + align:start position:0% +bit wrong you end up with one of the Q +pointers overrunning the other guy and + + align:start position:0% +pointers overrunning the other guy and + + + align:start position:0% +pointers overrunning the other guy and +you have basically dangling pointers and + + align:start position:0% +you have basically dangling pointers and + + + align:start position:0% +you have basically dangling pointers and +things like that. Um at least three or + + align:start position:0% +things like that. Um at least three or + + + align:start position:0% +things like that. Um at least three or +four times we spent a few hours until we + + align:start position:0% +four times we spent a few hours until we + + + align:start position:0% +four times we spent a few hours until we +discovered that was the cause of + + align:start position:0% +discovered that was the cause of + + + align:start position:0% +discovered that was the cause of +mysterious behavior. + + align:start position:0% + + + + align:start position:0% + +Okay, I + + align:start position:0% +Okay, I + + + align:start position:0% +Okay, I +[Applause] \ No newline at end of file diff --git a/t2PkbsWjG80.txt b/t2PkbsWjG80.txt new file mode 100644 index 0000000000000000000000000000000000000000..47e374e92e09e709465537257cea6c2b70134196 --- /dev/null +++ b/t2PkbsWjG80.txt @@ -0,0 +1,1139 @@ +align:start position:0% + +we would now like to calculate the + + align:start position:0% +we would now like to calculate the + + + align:start position:0% +we would now like to calculate the +potential function for a universal law + + align:start position:0% +potential function for a universal law + + + align:start position:0% +potential function for a universal law +of gravity so let's set up a coordinate + + align:start position:0% +of gravity so let's set up a coordinate + + + align:start position:0% +of gravity so let's set up a coordinate +system first and in this case we're + + align:start position:0% +system first and in this case we're + + + align:start position:0% +system first and in this case we're +going to make a very special case + + align:start position:0% +going to make a very special case + + + align:start position:0% +going to make a very special case +although the general result doesn't + + align:start position:0% +although the general result doesn't + + + align:start position:0% +although the general result doesn't +depend on that so suppose we have a + + align:start position:0% +depend on that so suppose we have a + + + align:start position:0% +depend on that so suppose we have a +planet of radius RP and we have a small + + align:start position:0% +planet of radius RP and we have a small + + + align:start position:0% +planet of radius RP and we have a small +object and initially our object is a + + align:start position:0% +object and initially our object is a + + + align:start position:0% +object and initially our object is a +distance R away from the planet this is + + align:start position:0% +distance R away from the planet this is + + + align:start position:0% +distance R away from the planet this is +our initial state and the planet has + + align:start position:0% +our initial state and the planet has + + + align:start position:0% +our initial state and the planet has +mass of the planet and our small object + + align:start position:0% +mass of the planet and our small object + + + align:start position:0% +mass of the planet and our small object +has mass and and this object is moving + + align:start position:0% +has mass and and this object is moving + + + align:start position:0% +has mass and and this object is moving +of course orbits really aren't like that + + align:start position:0% +of course orbits really aren't like that + + + align:start position:0% +of course orbits really aren't like that +so we should be a little bit more + + align:start position:0% +so we should be a little bit more + + + align:start position:0% +so we should be a little bit more +careful but our orbit might be some type + + align:start position:0% +careful but our orbit might be some type + + + align:start position:0% +careful but our orbit might be some type +of hyperbolic section conic section and + + align:start position:0% +of hyperbolic section conic section and + + + align:start position:0% +of hyperbolic section conic section and +the orbit over here is at some final + + align:start position:0% +the orbit over here is at some final + + + align:start position:0% +the orbit over here is at some final +position did and our eyes the distance + + align:start position:0% +position did and our eyes the distance + + + align:start position:0% +position did and our eyes the distance +from the object to the center of the + + align:start position:0% +from the object to the center of the + + + align:start position:0% +from the object to the center of the +planet as our final is now let's just + + align:start position:0% +planet as our final is now let's just + + + align:start position:0% +planet as our final is now let's just +because there's a central point in this + + align:start position:0% +because there's a central point in this + + + align:start position:0% +because there's a central point in this +problem the natural coordinate system to + + align:start position:0% +problem the natural coordinate system to + + + align:start position:0% +problem the natural coordinate system to +use is polar coordinates in the plane + + align:start position:0% +use is polar coordinates in the plane + + + align:start position:0% +use is polar coordinates in the plane +and let's just imagine that at this + + align:start position:0% +and let's just imagine that at this + + + align:start position:0% +and let's just imagine that at this +moment we have the universal force of + + align:start position:0% +moment we have the universal force of + + + align:start position:0% +moment we have the universal force of +gravity here's our object and it's being + + align:start position:0% +gravity here's our object and it's being + + + align:start position:0% +gravity here's our object and it's being +displaced a distance s so our coordinate + + align:start position:0% +displaced a distance s so our coordinate + + + align:start position:0% +displaced a distance s so our coordinate +system is polar + + align:start position:0% +system is polar + + + align:start position:0% +system is polar +let's call R hat this way and theta hat + + align:start position:0% +let's call R hat this way and theta hat + + + align:start position:0% +let's call R hat this way and theta hat +that way and let's blow up our little + + align:start position:0% +that way and let's blow up our little + + + align:start position:0% +that way and let's blow up our little +displacement in terms of our coordinate + + align:start position:0% +displacement in terms of our coordinate + + + align:start position:0% +displacement in terms of our coordinate +system just so that we see what's + + align:start position:0% +system just so that we see what's + + + align:start position:0% +system just so that we see what's +happening so our displacement had a + + align:start position:0% +happening so our displacement had a + + + align:start position:0% +happening so our displacement had a +let's imagine that our little DS vector + + align:start position:0% +let's imagine that our little DS vector + + + align:start position:0% +let's imagine that our little DS vector +is pointing like this and our center + + align:start position:0% +is pointing like this and our center + + + align:start position:0% +is pointing like this and our center +point here we have the R hat pointing + + align:start position:0% +point here we have the R hat pointing + + + align:start position:0% +point here we have the R hat pointing +radially outward and the theta hat + + align:start position:0% +radially outward and the theta hat + + + align:start position:0% +radially outward and the theta hat +pointing towards the center now to + + align:start position:0% +pointing towards the center now to + + + align:start position:0% +pointing towards the center now to +exaggerate this picture if this is R + + align:start position:0% +exaggerate this picture if this is R + + + align:start position:0% +exaggerate this picture if this is R +then the arc length here is Rd theta and + + align:start position:0% +then the arc length here is Rd theta and + + + align:start position:0% +then the arc length here is Rd theta and +the difference + + align:start position:0% +the difference + + + align:start position:0% +the difference +as the object moves from one point here + + align:start position:0% +as the object moves from one point here + + + align:start position:0% +as the object moves from one point here +to a closer point towards the center + + align:start position:0% +to a closer point towards the center + + + align:start position:0% +to a closer point towards the center +will be D R and so our D s vector we can + + align:start position:0% +will be D R and so our D s vector we can + + + align:start position:0% +will be D R and so our D s vector we can +write as a radial piece R hat now I + + align:start position:0% +write as a radial piece R hat now I + + + align:start position:0% +write as a radial piece R hat now I +don't put a sign in there because only + + align:start position:0% +don't put a sign in there because only + + + align:start position:0% +don't put a sign in there because only +the endpoints of my integral will tell + + align:start position:0% +the endpoints of my integral will tell + + + align:start position:0% +the endpoints of my integral will tell +me whether I was going towards the + + align:start position:0% +me whether I was going towards the + + + align:start position:0% +me whether I was going towards the +planet or away from the planet and our D + + align:start position:0% +planet or away from the planet and our D + + + align:start position:0% +planet or away from the planet and our D +theta theta hat and our gravitational + + align:start position:0% +theta theta hat and our gravitational + + + align:start position:0% +theta theta hat and our gravitational +force is minus G mass mass of the planet + + align:start position:0% +force is minus G mass mass of the planet + + + align:start position:0% +force is minus G mass mass of the planet +over the distance squared R hat so now + + align:start position:0% +over the distance squared R hat so now + + + align:start position:0% +over the distance squared R hat so now +what we see is that when we take the dot + + align:start position:0% +what we see is that when we take the dot + + + align:start position:0% +what we see is that when we take the dot +product of these two forces our hat down + + align:start position:0% +product of these two forces our hat down + + + align:start position:0% +product of these two forces our hat down +our hat is one in polar coordinates why + + align:start position:0% +our hat is one in polar coordinates why + + + align:start position:0% +our hat is one in polar coordinates why +is that the case our hat dot R hat is + + align:start position:0% +is that the case our hat dot R hat is + + + align:start position:0% +is that the case our hat dot R hat is +one because these vectors are purpose of + + align:start position:0% +one because these vectors are purpose of + + + align:start position:0% +one because these vectors are purpose of +the same direction the angle between + + align:start position:0% +the same direction the angle between + + + align:start position:0% +the same direction the angle between +them is zero and remember that any two + + align:start position:0% +them is zero and remember that any two + + + align:start position:0% +them is zero and remember that any two +vectors that are perpendicular have dot + + align:start position:0% +vectors that are perpendicular have dot + + + align:start position:0% +vectors that are perpendicular have dot +product zero R hat and beta hat are + + align:start position:0% +product zero R hat and beta hat are + + + align:start position:0% +product zero R hat and beta hat are +perpendicular and so R hat dot R hat is + + align:start position:0% +perpendicular and so R hat dot R hat is + + + align:start position:0% +perpendicular and so R hat dot R hat is +1 R hat dot theta hat is 0 so we only + + align:start position:0% +1 R hat dot theta hat is 0 so we only + + + align:start position:0% +1 R hat dot theta hat is 0 so we only +get minus g-m P R squared D R and that's + + align:start position:0% +get minus g-m P R squared D R and that's + + + align:start position:0% +get minus g-m P R squared D R and that's +the first step in calculating our + + align:start position:0% +the first step in calculating our + + + align:start position:0% +the first step in calculating our +potential difference because you of our + + align:start position:0% +potential difference because you of our + + + align:start position:0% +potential difference because you of our +final minus you of our initial by + + align:start position:0% +final minus you of our initial by + + + align:start position:0% +final minus you of our initial by +definition is minus the work done in + + align:start position:0% +definition is minus the work done in + + + align:start position:0% +definition is minus the work done in +going from the initial state to the + + align:start position:0% +going from the initial state to the + + + align:start position:0% +going from the initial state to the +final state which are described by these + + align:start position:0% +final state which are described by these + + + align:start position:0% +final state which are described by these +parameters our initial in our final of F + + align:start position:0% +parameters our initial in our final of F + + + align:start position:0% +parameters our initial in our final of F +gravitational dot d s and now we have + + align:start position:0% +gravitational dot d s and now we have + + + align:start position:0% +gravitational dot d s and now we have +actually minus sign in the definition + + align:start position:0% +actually minus sign in the definition + + + align:start position:0% +actually minus sign in the definition +another minus sign coming from the dot + + align:start position:0% +another minus sign coming from the dot + + + align:start position:0% +another minus sign coming from the dot +product and let's make this our + + align:start position:0% +product and let's make this our + + + align:start position:0% +product and let's make this our +integration variable our prime our + + align:start position:0% +integration variable our prime our + + + align:start position:0% +integration variable our prime our +initial R prime equals our final and + + align:start position:0% +initial R prime equals our final and + + + align:start position:0% +initial R prime equals our final and +there's going to be a third minus sign + + align:start position:0% +there's going to be a third minus sign + + + align:start position:0% +there's going to be a third minus sign +because the integral of D RR prime + + align:start position:0% +because the integral of D RR prime + + + align:start position:0% +because the integral of D RR prime +squared is minus one over R prime so + + align:start position:0% +squared is minus one over R prime so + + + align:start position:0% +squared is minus one over R prime so +there'll be three minus signs one from + + align:start position:0% +there'll be three minus signs one from + + + align:start position:0% +there'll be three minus signs one from +the definition one from the scalar + + align:start position:0% +the definition one from the scalar + + + align:start position:0% +the definition one from the scalar +product and one from the integration and + + align:start position:0% +product and one from the integration and + + + align:start position:0% +product and one from the integration and +so we get our final + + align:start position:0% +so we get our final + + + align:start position:0% +so we get our final +- our initial equals three minus signs + + align:start position:0% +- our initial equals three minus signs + + + align:start position:0% +- our initial equals three minus signs +give an overall minus sign G M and + + align:start position:0% +give an overall minus sign G M and + + + align:start position:0% +give an overall minus sign G M and +planet one over our final minus one over + + align:start position:0% +planet one over our final minus one over + + + align:start position:0% +planet one over our final minus one over +our initial so this is the change in + + align:start position:0% +our initial so this is the change in + + + align:start position:0% +our initial so this is the change in +gravitational potential energy as my + + align:start position:0% +gravitational potential energy as my + + + align:start position:0% +gravitational potential energy as my +small object goes from some initial + + align:start position:0% +small object goes from some initial + + + align:start position:0% +small object goes from some initial +state to some final state what about the + + align:start position:0% +state to some final state what about the + + + align:start position:0% +state to some final state what about the +potential function where should we + + align:start position:0% +potential function where should we + + + align:start position:0% +potential function where should we +choose our reference point now so our + + align:start position:0% +choose our reference point now so our + + + align:start position:0% +choose our reference point now so our +reference state here is a little bit + + align:start position:0% +reference state here is a little bit + + + align:start position:0% +reference state here is a little bit +unusual and it will be at infinity and + + align:start position:0% +unusual and it will be at infinity and + + + align:start position:0% +unusual and it will be at infinity and +we'll choose as a potential for our + + align:start position:0% +we'll choose as a potential for our + + + align:start position:0% +we'll choose as a potential for our +reference potential to be zero at + + align:start position:0% +reference potential to be zero at + + + align:start position:0% +reference potential to be zero at +infinity that means when our imagine an + + align:start position:0% +infinity that means when our imagine an + + + align:start position:0% +infinity that means when our imagine an +initial state very very far away from + + align:start position:0% +initial state very very far away from + + + align:start position:0% +initial state very very far away from +the planet and we'll take as a final + + align:start position:0% +the planet and we'll take as a final + + + align:start position:0% +the planet and we'll take as a final +state an arbitrary state just where the + + align:start position:0% +state an arbitrary state just where the + + + align:start position:0% +state an arbitrary state just where the +object is some distance R from the + + align:start position:0% +object is some distance R from the + + + align:start position:0% +object is some distance R from the +planet now we have to be a little bit + + align:start position:0% +planet now we have to be a little bit + + + align:start position:0% +planet now we have to be a little bit +careful because in this calculation are + + align:start position:0% +careful because in this calculation are + + + align:start position:0% +careful because in this calculation are +always our final state must always be + + align:start position:0% +always our final state must always be + + + align:start position:0% +always our final state must always be +outside the planet when the reasons for + + align:start position:0% +outside the planet when the reasons for + + + align:start position:0% +outside the planet when the reasons for +that is subtle but the gravitational + + align:start position:0% +that is subtle but the gravitational + + + align:start position:0% +that is subtle but the gravitational +force inside the planet is no longer + + align:start position:0% +force inside the planet is no longer + + + align:start position:0% +force inside the planet is no longer +minus G m1 m2 over R squared so our + + align:start position:0% +minus G m1 m2 over R squared so our + + + align:start position:0% +minus G m1 m2 over R squared so our +analysis only applies for our bigger + + align:start position:0% +analysis only applies for our bigger + + + align:start position:0% +analysis only applies for our bigger +than our planet and if we put these + + align:start position:0% +than our planet and if we put these + + + align:start position:0% +than our planet and if we put these +values for R and infinity in here we get + + align:start position:0% +values for R and infinity in here we get + + + align:start position:0% +values for R and infinity in here we get +U of R minus the potential at our + + align:start position:0% +U of R minus the potential at our + + + align:start position:0% +U of R minus the potential at our +reference point which will be 0 equals + + align:start position:0% +reference point which will be 0 equals + + + align:start position:0% +reference point which will be 0 equals +minus g-m and P and here's the reason + + align:start position:0% +minus g-m and P and here's the reason + + + align:start position:0% +minus g-m and P and here's the reason +why we choose that reference point 1 + + align:start position:0% +why we choose that reference point 1 + + + align:start position:0% +why we choose that reference point 1 +over our arbitrary state is just minus 1 + + align:start position:0% +over our arbitrary state is just minus 1 + + + align:start position:0% +over our arbitrary state is just minus 1 +over 1 over R but 1 over infinity if we + + align:start position:0% +over 1 over R but 1 over infinity if we + + + align:start position:0% +over 1 over R but 1 over infinity if we +use the initial state as the reference + + align:start position:0% +use the initial state as the reference + + + align:start position:0% +use the initial state as the reference +point 1 over infinity is 0 so that's + + align:start position:0% +point 1 over infinity is 0 so that's + + + align:start position:0% +point 1 over infinity is 0 so that's +minus 0 and so what we get is that the + + align:start position:0% +minus 0 and so what we get is that the + + + align:start position:0% +minus 0 and so what we get is that the +potential function is equal to our + + align:start position:0% +potential function is equal to our + + + align:start position:0% +potential function is equal to our +reference potential plot actually minus + + align:start position:0% +reference potential plot actually minus + + + align:start position:0% +reference potential plot actually minus +g-m mass of the planet over R for R + + align:start position:0% +g-m mass of the planet over R for R + + + align:start position:0% +g-m mass of the planet over R for R +bigger than our + + align:start position:0% +bigger than our + + + align:start position:0% +bigger than our +reference and that is the potential + + align:start position:0% +reference and that is the potential + + + align:start position:0% +reference and that is the potential +function for the gravitational problem + + align:start position:0% +function for the gravitational problem + + + align:start position:0% +function for the gravitational problem +but now remember we're choosing that to + + align:start position:0% +but now remember we're choosing that to + + + align:start position:0% +but now remember we're choosing that to +be our reference point and so the real + + align:start position:0% +be our reference point and so the real + + + align:start position:0% +be our reference point and so the real +conclusion is U of R equals minus g-m + + align:start position:0% +conclusion is U of R equals minus g-m + + + align:start position:0% +conclusion is U of R equals minus g-m +and planet over R with you at infinity + + align:start position:0% +and planet over R with you at infinity + + + align:start position:0% +and planet over R with you at infinity +equal to zero now let's just finish this + + align:start position:0% +equal to zero now let's just finish this + + + align:start position:0% +equal to zero now let's just finish this +by saying in words precisely what this + + align:start position:0% +by saying in words precisely what this + + + align:start position:0% +by saying in words precisely what this +means so if I start my system at + + align:start position:0% +means so if I start my system at + + + align:start position:0% +means so if I start my system at +infinity and I end my system a distance + + align:start position:0% +infinity and I end my system a distance + + + align:start position:0% +infinity and I end my system a distance +R away from the planet and I calculate + + align:start position:0% +R away from the planet and I calculate + + + align:start position:0% +R away from the planet and I calculate +the work done by the gravitational force + + align:start position:0% +the work done by the gravitational force + + + align:start position:0% +the work done by the gravitational force +in going from infinity to a distance R + + align:start position:0% +in going from infinity to a distance R + + + align:start position:0% +in going from infinity to a distance R +away from the planet I take a minus that + + align:start position:0% +away from the planet I take a minus that + + + align:start position:0% +away from the planet I take a minus that +sign so the negative of the + + align:start position:0% +sign so the negative of the + + + align:start position:0% +sign so the negative of the +gravitational work then that's what that + + align:start position:0% +gravitational work then that's what that + + + align:start position:0% +gravitational work then that's what that +number corresponds to \ No newline at end of file diff --git a/tMr9XH64rtM.txt b/tMr9XH64rtM.txt new file mode 100644 index 0000000000000000000000000000000000000000..8b0abb3afd7aaa511a16094b1004469d6eb84a4e --- /dev/null +++ b/tMr9XH64rtM.txt @@ -0,0 +1,345 @@ +PROFESSOR: Now, onward. + +Transcription. + +So, we've got DNA, we'll do two, +three, probably three by + +now, transcription. + +So we have DNA goes to DNA. + +DNA makes RNA, RNA +makes protein. + +This, by the way, gets the +name the central dogma of + +molecular biology. + +Due to Francis Crick, and as +an aside, Francis actually + +never said DNA goes to +RNA goes to protein. + +What he said was nucleic +acids go to protein. + +The information flows from +nucleic acids to proteins. + +He never actually said DNA goes +to RNA goes to protein, + +and that's an important point. + +And we'll come to it at some +point, probably next time. + +So, transcription. + +Here's my genome. + +Here's my double helix. + +I'm going to stop wrapping +around itself, just because + +it's tedious. + +And here's a chunk of DNA +that encodes a gene. + +Maybe it's a gene that makes +our enzyme for arginine + +biosynthesis. + +Remember, we had our arginine +genes and all that. + +But what happens is it has a +starting point, it has a + +stopping point. + +Five prime to three prime. + +What happens is there is a +signal in the DNA that the + +cell knows how to read +called a promoter. + +And under certain circumstances, +this promoter + +invites an enzyme to sit down, +and the enzyme starts copying. + +Which direction does +this enzyme go? + +Five prime to three prime. + +They all go five prime +to three prime. + +But it makes RNA. + +Okay? + +And then it gets to certain +point, and it stops copying. + +This process of copying is +called transcription, because + +it's just a direct +transcribing. + +So what's the difference +between DNA and RNA? + +Two differences. + +One, this is two prime +deoxyribose. + +This is ribose. + +It's not two prime deoxy. + +It's truly ribose. + +The other difference, where DNA +has T, RNA, has U, uracil. + +The difference, what's the +difference between T and U? + +The difference is +a methyl group. + +It's a methyl group in an +unimportant position for the + +base paring. + +It doesn't matter. + +It has an extra methyl group. + +You can look it up +in your book. + +So for all practical purposes, +you, in thinking about + +polymerization and five prime +to three prime, and + +everything, could imagine the +DNA and RNA are the same basic + +structure, because it's got one +little methyl group that + +distinguishes T and U. And it's +got a hydroxyl on the two + +prime position in the carbon, +in the sugar, which actually + +isn't anything we use. + +We never use the two prime. + +So none of what I've told you is +affected by t versus u, or + +deoxyribose versus ribose. + +Now, it turns out it does +make a difference + +in the overall structure. + +It's harder to base pair with +the ribose there as opposed to + +the deoxyribose because they +stack differently, et cetera. + +It makes a difference +to the cell. + +RNA is less stable, all +sorts of things. + +But for your practical purposes, +apart from having to + +know that it's T versus U, and +deoxyribose versus ribose, you + +won't see in this course +actually see any real strong + +reasons why it matters, but it +does matter to the cell. + +All right. + +So this enzyme comes along, and +it copies a segment of the + +DNA, starting at a promoter. + +It knows which strand it's on. + +Remember, this is stranded. + +It's not like it's going +back this way. + +It has a directionality to it. + +And in reaches what's called a +transcriptional stop signal. + +Transcriptional stop, which is a +certain sequence in the DNA, + +and it comes to an end. + +And it makes an RNA transcript, + +which then floats away. + +Which we'll talk +next time, gets + +translated into a protein. + +And how do you think +this works? + +It takes nucleotides, RNA +nucleotides here, with their + +triphosphates, and sticks them +on, just like we saw with DNA. + +And it makes a polymer of RNA. + +And the enzyme is called +RNA polymerase, right? + +This is all pretty +logical stuff. + +RNA polymerase comes along +and does that. + +So we get RNA polymerase. + +Now, when I am a cell, and this +is my genome, I have a + +gene that goes this way. + +Here's its promoter, here's +its transcriptional stop. + +I could also have a gene +that goes this way. + +Here's its promoter, here's +its transcriptional stop. + +Directionality could go +in either direction. + +RNA polymerase comes along, and +with the help of friends, + +knows where to start. + +Those friends could be other +proteins that are sitting down + +there that RNA polymerase +likes to associate with. + +And which strand is +being transcribed? + +The bottom strand, or +the top strand? + +Matters. + +You get a different single +stranded RNA. + +So RNA, when it floats off, +is single stranded. + +This is going to make a single +stranded RNA that, five prime + +to three prime RNA that is +complimentary to, matching to, + +the bottom. + +This guy, however, will make an +RNA that is complimentary + +to the top. + +Much of the business of running +your cell is figuring + +out which genes you should +be transcribing into RNA. + +It turns out your liver is +making different transcripts. + +It's transcribing different +segments of your genome than + +say, a muscle cell. + +Than say, a brain cell. + +All of that machinery of +figuring out how one genome + +gets read out in different ways +by RNA polymerase is the + +problem of gene regulation. + +And we will talk about that +in a little while. + +What we're going to talk about +next time is how that RNA + +transcript gets translated +into a protein. + +And you guys probably, +again, all know this. + +But nonetheless, we'll talk +a little bit about it. + +And then we'll talk about some +variations on that theme. + +Until next time. \ No newline at end of file diff --git a/tkglOK3ZEsI.txt b/tkglOK3ZEsI.txt new file mode 100644 index 0000000000000000000000000000000000000000..55d4b067c3629fd1b0e080308f8300d5261d9781 --- /dev/null +++ b/tkglOK3ZEsI.txt @@ -0,0 +1,12200 @@ +align:start position:0% + +foreign + + align:start position:0% + + + + align:start position:0% + +so so last time + + align:start position:0% +so so last time + + + align:start position:0% +so so last time +we started talking about the following + + align:start position:0% +we started talking about the following + + + align:start position:0% +we started talking about the following +process + + align:start position:0% + + + + align:start position:0% + +so you consider + + align:start position:0% + + + + align:start position:0% + +e plus e minus + + align:start position:0% +e plus e minus + + + align:start position:0% +e plus e minus +so electron voltage on the scatter + + align:start position:0% +so electron voltage on the scatter + + + align:start position:0% +so electron voltage on the scatter +and then they will allow it and then + + align:start position:0% +and then they will allow it and then + + + align:start position:0% +and then they will allow it and then +they create some other particles + + align:start position:0% + + + + align:start position:0% + +okay so B and B Bar some feral particles + + align:start position:0% +okay so B and B Bar some feral particles + + + align:start position:0% +okay so B and B Bar some feral particles +okay can be can be different kind of + + align:start position:0% +okay can be can be different kind of + + + align:start position:0% +okay can be can be different kind of +things so if we draw the function + + align:start position:0% +things so if we draw the function + + + align:start position:0% +things so if we draw the function +diagram with the time going up + + align:start position:0% +diagram with the time going up + + + align:start position:0% +diagram with the time going up +and then then the uh then the process + + align:start position:0% +and then then the uh then the process + + + align:start position:0% +and then then the uh then the process +will be like falling + + align:start position:0% + + + + align:start position:0% + +so the um so the initial particle + + align:start position:0% +so the um so the initial particle + + + align:start position:0% +so the um so the initial particle +so this is the E minus and this is e + + align:start position:0% +so this is the E minus and this is e + + + align:start position:0% +so this is the E minus and this is e +plus and then we have + + align:start position:0% +plus and then we have + + + align:start position:0% +plus and then we have +B and B Bar okay + + align:start position:0% +B and B Bar okay + + + align:start position:0% +B and B Bar okay +so we can um + + align:start position:0% +so we can um + + + align:start position:0% +so we can um +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +so such a process + + align:start position:0% +so such a process + + + align:start position:0% +so such a process +is a very important Discovery machine + + align:start position:0% +is a very important Discovery machine + + + align:start position:0% +is a very important Discovery machine +for new particles + + align:start position:0% +for new particles + + + align:start position:0% +for new particles +okay + + align:start position:0% +okay + + + align:start position:0% +okay +um very important + + align:start position:0% + + + + align:start position:0% + +particles + + align:start position:0% + + + + align:start position:0% + +so let me just mention two examples here + + align:start position:0% +so let me just mention two examples here + + + align:start position:0% +so let me just mention two examples here +so in 1974 + + align:start position:0% +so in 1974 + + + align:start position:0% +so in 1974 +to 1976 + + align:start position:0% +to 1976 + + + align:start position:0% +to 1976 +at Slack + + align:start position:0% +at Slack + + + align:start position:0% +at Slack +so slack is called Stanford linear + + align:start position:0% +so slack is called Stanford linear + + + align:start position:0% +so slack is called Stanford linear +acceleration Center so they have a + + align:start position:0% +acceleration Center so they have a + + + align:start position:0% +acceleration Center so they have a +electron Collider + + align:start position:0% +electron Collider + + + align:start position:0% +electron Collider +and so there they first discovered the + + align:start position:0% +and so there they first discovered the + + + align:start position:0% +and so there they first discovered the +towel + + align:start position:0% +towel + + + align:start position:0% +towel +particle + + align:start position:0% + + + + align:start position:0% + +okay and this top particle + + align:start position:0% +okay and this top particle + + + align:start position:0% +okay and this top particle +with mass is the 1.8 gev Okay so + + align:start position:0% +with mass is the 1.8 gev Okay so + + + align:start position:0% +with mass is the 1.8 gev Okay so +when they + + align:start position:0% +when they + + + align:start position:0% +when they +um + + align:start position:0% + + + + align:start position:0% + +when you or when your total energy is + + align:start position:0% +when you or when your total energy is + + + align:start position:0% +when you or when your total energy is +greater than this one twice the one + + align:start position:0% +greater than this one twice the one + + + align:start position:0% +greater than this one twice the one +point in the GV then you can in + + align:start position:0% +point in the GV then you can in + + + align:start position:0% +point in the GV then you can in +principle create the pair created this + + align:start position:0% +principle create the pair created this + + + align:start position:0% +principle create the pair created this +top part Tau plus and Tall menus + + align:start position:0% +top part Tau plus and Tall menus + + + align:start position:0% +top part Tau plus and Tall menus +and another example + + align:start position:0% +and another example + + + align:start position:0% +and another example +is in 1974 + + align:start position:0% +is in 1974 + + + align:start position:0% +is in 1974 +again at the slack + + align:start position:0% +again at the slack + + + align:start position:0% +again at the slack +and the E plus e minus + + align:start position:0% +and the E plus e minus + + + align:start position:0% +and the E plus e minus +goes to CC Bar + + align:start position:0% +goes to CC Bar + + + align:start position:0% +goes to CC Bar +so C is the chunk Park here + + align:start position:0% +so C is the chunk Park here + + + align:start position:0% +so C is the chunk Park here +okay it's the time clock here so what + + align:start position:0% +okay it's the time clock here so what + + + align:start position:0% +okay it's the time clock here so what +they observed is the bump state of the + + align:start position:0% +they observed is the bump state of the + + + align:start position:0% +they observed is the bump state of the +CC Bar called JSI + + align:start position:0% +CC Bar called JSI + + + align:start position:0% +CC Bar called JSI +so under the mass of the JSI is about + + align:start position:0% +so under the mass of the JSI is about + + + align:start position:0% +so under the mass of the JSI is about +3.1 Kev + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +3.1 guv + + align:start position:0% +3.1 guv + + + align:start position:0% +3.1 guv +so so this JSI uh so so this particle + + align:start position:0% +so so this JSI uh so so this particle + + + align:start position:0% +so so this JSI uh so so this particle +was discovered + + align:start position:0% +was discovered + + + align:start position:0% +was discovered +at the same time + + align:start position:0% +at the same time + + + align:start position:0% +at the same time +at Brookhaven + + align:start position:0% +at Brookhaven + + + align:start position:0% +at Brookhaven +by through the proton quite through the + + align:start position:0% +by through the proton quite through the + + + align:start position:0% +by through the proton quite through the +conditioning of the protons by by our + + align:start position:0% +conditioning of the protons by by our + + + align:start position:0% +conditioning of the protons by by our +own colleagues Samuel team + + align:start position:0% +own colleagues Samuel team + + + align:start position:0% +own colleagues Samuel team +and then they both get the Bell price in + + align:start position:0% +and then they both get the Bell price in + + + align:start position:0% +and then they both get the Bell price in +1975 I think okay + + align:start position:0% +1975 I think okay + + + align:start position:0% +1975 I think okay +so uh uh there was actually a funny + + align:start position:0% +so uh uh there was actually a funny + + + align:start position:0% +so uh uh there was actually a funny +story regarding the discovery of this + + align:start position:0% +story regarding the discovery of this + + + align:start position:0% +story regarding the discovery of this +particle + + align:start position:0% +particle + + + align:start position:0% +particle +so uh so at Brookhaven they + + align:start position:0% +so uh so at Brookhaven they + + + align:start position:0% +so uh so at Brookhaven they +they cried the protons on the abyss + + align:start position:0% +they cried the protons on the abyss + + + align:start position:0% +they cried the protons on the abyss +fixed Target so that is a much massier + + align:start position:0% +fixed Target so that is a much massier + + + align:start position:0% +fixed Target so that is a much massier +machine + + align:start position:0% +machine + + + align:start position:0% +machine +because proton contain lots of uh yeah + + align:start position:0% +because proton contain lots of uh yeah + + + align:start position:0% +because proton contain lots of uh yeah +contain quarks and plurals and so + + align:start position:0% +contain quarks and plurals and so + + + align:start position:0% +contain quarks and plurals and so +um yeah it's + + align:start position:0% +um yeah it's + + + align:start position:0% +um yeah it's +restoring interactions so so uh if you + + align:start position:0% +restoring interactions so so uh if you + + + align:start position:0% +restoring interactions so so uh if you +create the highness yeah if your client + + align:start position:0% +create the highness yeah if your client + + + align:start position:0% +create the highness yeah if your client +had high enough energy you can create + + align:start position:0% +had high enough energy you can create + + + align:start position:0% +had high enough energy you can create +any uh any particles but since you move + + align:start position:0% +any uh any particles but since you move + + + align:start position:0% +any uh any particles but since you move +in strong interactions and strong + + align:start position:0% +in strong interactions and strong + + + align:start position:0% +in strong interactions and strong +interaction have many many particles so + + align:start position:0% +interaction have many many particles so + + + align:start position:0% +interaction have many many particles so +the pro so the client at Brookhaven is + + align:start position:0% +the pro so the client at Brookhaven is + + + align:start position:0% +the pro so the client at Brookhaven is +very very messy + + align:start position:0% +very very messy + + + align:start position:0% +very very messy +okay so in order to find the new + + align:start position:0% +okay so in order to find the new + + + align:start position:0% +okay so in order to find the new +particles it's very very difficult okay + + align:start position:0% +particles it's very very difficult okay + + + align:start position:0% +particles it's very very difficult okay +but but they manage find this new + + align:start position:0% +but but they manage find this new + + + align:start position:0% +but but they manage find this new +particle at Brookhaven + + align:start position:0% +particle at Brookhaven + + + align:start position:0% +particle at Brookhaven +and but Sameer thing was + + align:start position:0% +and but Sameer thing was + + + align:start position:0% +and but Sameer thing was +uh famously + + align:start position:0% +uh famously + + + align:start position:0% +uh famously +extraordinary meticulous okay so he + + align:start position:0% +extraordinary meticulous okay so he + + + align:start position:0% +extraordinary meticulous okay so he +wanted to be absolutely right okay so he + + align:start position:0% +wanted to be absolutely right okay so he + + + align:start position:0% +wanted to be absolutely right okay so he +was checking and checking + + align:start position:0% +was checking and checking + + + align:start position:0% +was checking and checking +so during one of the yeah so this is a + + align:start position:0% +so during one of the yeah so this is a + + + align:start position:0% +so during one of the yeah so this is a +rumor so so the rumor said that during + + align:start position:0% +rumor so so the rumor said that during + + + align:start position:0% +rumor so so the rumor said that during +the one of the check-in process + + align:start position:0% +the one of the check-in process + + + align:start position:0% +the one of the check-in process +and somehow + + align:start position:0% +and somehow + + + align:start position:0% +and somehow +the room was private + + align:start position:0% +the room was private + + + align:start position:0% +the room was private +that he discovered a new particle + + align:start position:0% +that he discovered a new particle + + + align:start position:0% +that he discovered a new particle +and so the person was still in the + + align:start position:0% +and so the person was still in the + + + align:start position:0% +and so the person was still in the +experiment at the slack then caught him + + align:start position:0% +experiment at the slack then caught him + + + align:start position:0% +experiment at the slack then caught him +up + + align:start position:0% +up + + + align:start position:0% +up +even the rumor of the rumor even yeah so + + align:start position:0% +even the rumor of the rumor even yeah so + + + align:start position:0% +even the rumor of the rumor even yeah so +uh so so the news leaked it even leaked + + align:start position:0% +uh so so the news leaked it even leaked + + + align:start position:0% +uh so so the news leaked it even leaked +the energy scale of the particle they + + align:start position:0% +the energy scale of the particle they + + + align:start position:0% +the energy scale of the particle they +found okay + + align:start position:0% +found okay + + + align:start position:0% +found okay +and then the person was doing the + + align:start position:0% +and then the person was doing the + + + align:start position:0% +and then the person was doing the +visitor at the slack and then called the + + align:start position:0% +visitor at the slack and then called the + + + align:start position:0% +visitor at the slack and then called the +same thing he said oh uh uh uh I heard + + align:start position:0% +same thing he said oh uh uh uh I heard + + + align:start position:0% +same thing he said oh uh uh uh I heard +you have found a new particle + + align:start position:0% +you have found a new particle + + + align:start position:0% +you have found a new particle +no no I didn't + + align:start position:0% +no no I didn't + + + align:start position:0% +no no I didn't +yeah because he didn't want to have the + + align:start position:0% +yeah because he didn't want to have the + + + align:start position:0% +yeah because he didn't want to have the +uh uh + + align:start position:0% +uh uh + + + align:start position:0% +uh uh +yeah actually it's not very good because + + align:start position:0% +yeah actually it's not very good because + + + align:start position:0% +yeah actually it's not very good because +I'm recorded + + align:start position:0% + + + + align:start position:0% + +I recorded so so I think this uh maybe + + align:start position:0% +I recorded so so I think this uh maybe + + + align:start position:0% +I recorded so so I think this uh maybe +it's not the good spread rumors + + align:start position:0% +it's not the good spread rumors + + + align:start position:0% +it's not the good spread rumors +it is not recorded actually I can tell + + align:start position:0% +it is not recorded actually I can tell + + + align:start position:0% +it is not recorded actually I can tell +the story uh yeah anyway so so so + + align:start position:0% +the story uh yeah anyway so so so + + + align:start position:0% +the story uh yeah anyway so so so +accordingly and then then then + + align:start position:0% +accordingly and then then then + + + align:start position:0% +accordingly and then then then +the a rich eater and they say oh you + + align:start position:0% +the a rich eater and they say oh you + + + align:start position:0% +the a rich eater and they say oh you +didn't find the particle that I can + + align:start position:0% +didn't find the particle that I can + + + align:start position:0% +didn't find the particle that I can +Discover it + + align:start position:0% +Discover it + + + align:start position:0% +Discover it +because they already knew the energy + + align:start position:0% +because they already knew the energy + + + align:start position:0% +because they already knew the energy +scale they already heard the role model + + align:start position:0% +scale they already heard the role model + + + align:start position:0% +scale they already heard the role model +energy scale and this is a very very + + align:start position:0% +energy scale and this is a very very + + + align:start position:0% +energy scale and this is a very very +clean machine + + align:start position:0% +clean machine + + + align:start position:0% +clean machine +so electron positive and declined the + + align:start position:0% +so electron positive and declined the + + + align:start position:0% +so electron positive and declined the +only energy created and so you don't + + align:start position:0% +only energy created and so you don't + + + align:start position:0% +only energy created and so you don't +create a lot of chunks and if you add to + + align:start position:0% +create a lot of chunks and if you add to + + + align:start position:0% +create a lot of chunks and if you add to +the right energy you can immediately + + align:start position:0% +the right energy you can immediately + + + align:start position:0% +the right energy you can immediately +find the new particle you don't need to + + align:start position:0% +find the new particle you don't need to + + + align:start position:0% +find the new particle you don't need to +do much work and so they put the the + + align:start position:0% +do much work and so they put the the + + + align:start position:0% +do much work and so they put the the +machine at that energy immediately new + + align:start position:0% +machine at that energy immediately new + + + align:start position:0% +machine at that energy immediately new +particle was discovered + + align:start position:0% +particle was discovered + + + align:start position:0% +particle was discovered +okay and so they uh they were um yeah so + + align:start position:0% +okay and so they uh they were um yeah so + + + align:start position:0% +okay and so they uh they were um yeah so +they were avoided Nobel Prize jointly + + align:start position:0% +they were avoided Nobel Prize jointly + + + align:start position:0% +they were avoided Nobel Prize jointly +um anyway so so this was a important + + align:start position:0% +um anyway so so this was a important + + + align:start position:0% +um anyway so so this was a important +discovery + + align:start position:0% +discovery + + + align:start position:0% +discovery +because the because before that people + + align:start position:0% +because the because before that people + + + align:start position:0% +because the because before that people +didn't believe quarks exist okay even + + align:start position:0% +didn't believe quarks exist okay even + + + align:start position:0% +didn't believe quarks exist okay even +though people didn't quite believe the + + align:start position:0% +though people didn't quite believe the + + + align:start position:0% +though people didn't quite believe the +clock existed even though they're there + + align:start position:0% +clock existed even though they're there + + + align:start position:0% +clock existed even though they're there +are many models Etc and there are lots + + align:start position:0% +are many models Etc and there are lots + + + align:start position:0% +are many models Etc and there are lots +of other evidences but this was the + + align:start position:0% +of other evidences but this was the + + + align:start position:0% +of other evidences but this was the +first uh uh uh uh the the the first uh + + align:start position:0% +first uh uh uh uh the the the first uh + + + align:start position:0% +first uh uh uh uh the the the first uh +yeah because sea Clark is very strongly + + align:start position:0% +yeah because sea Clark is very strongly + + + align:start position:0% +yeah because sea Clark is very strongly +uh it is very heavy and so see and the C + + align:start position:0% +uh it is very heavy and so see and the C + + + align:start position:0% +uh it is very heavy and so see and the C +bar the the band not very strongly and + + align:start position:0% +bar the the band not very strongly and + + + align:start position:0% +bar the the band not very strongly and +so this is the first evidence a direct + + align:start position:0% +so this is the first evidence a direct + + + align:start position:0% +so this is the first evidence a direct +evidence actually clock existence and so + + align:start position:0% +evidence actually clock existence and so + + + align:start position:0% +evidence actually clock existence and so +this actually shocked the community so + + align:start position:0% +this actually shocked the community so + + + align:start position:0% +this actually shocked the community so +this was discovered in in October so + + align:start position:0% +this was discovered in in October so + + + align:start position:0% +this was discovered in in October so +they call it October Revolution and uh + + align:start position:0% +they call it October Revolution and uh + + + align:start position:0% +they call it October Revolution and uh +um yeah + + align:start position:0% +um yeah + + + align:start position:0% +um yeah +so uh um yeah played a very important + + align:start position:0% +so uh um yeah played a very important + + + align:start position:0% +so uh um yeah played a very important +role in in understand yeah for people to + + align:start position:0% +role in in understand yeah for people to + + + align:start position:0% +role in in understand yeah for people to +accept the existence of clocks + + align:start position:0% +accept the existence of clocks + + + align:start position:0% +accept the existence of clocks +anyway so + + align:start position:0% +anyway so + + + align:start position:0% +anyway so +in particular by looking at + + align:start position:0% +in particular by looking at + + + align:start position:0% +in particular by looking at +the more General process + + align:start position:0% +the more General process + + + align:start position:0% +the more General process +so this goes to hydrons + + align:start position:0% + + + + align:start position:0% + +okay you just Collide them and then you + + align:start position:0% +okay you just Collide them and then you + + + align:start position:0% +okay you just Collide them and then you +look at it's going to hydrons you can + + align:start position:0% +look at it's going to hydrons you can + + + align:start position:0% +look at it's going to hydrons you can +actually can show + + align:start position:0% + + + + align:start position:0% + +that + + align:start position:0% +that + + + align:start position:0% +that +the clock has three colors + + align:start position:0% + + + + align:start position:0% + +okay make sure I have crop I have three + + align:start position:0% +okay make sure I have crop I have three + + + align:start position:0% +okay make sure I have crop I have three +colors + + align:start position:0% +colors + + + align:start position:0% +colors +and uh yeah so we will we will see that + + align:start position:0% +and uh yeah so we will we will see that + + + align:start position:0% +and uh yeah so we will we will see that +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so so before doing that let's uh first + + align:start position:0% +so so before doing that let's uh first + + + align:start position:0% +so so before doing that let's uh first +have to do a calculation + + align:start position:0% +have to do a calculation + + + align:start position:0% +have to do a calculation +okay so so we have to calculate this + + align:start position:0% +okay so so we have to calculate this + + + align:start position:0% +okay so so we have to calculate this +explicitly + + align:start position:0% +explicitly + + + align:start position:0% +explicitly +well let me see I get my page a little + + align:start position:0% +well let me see I get my page a little + + + align:start position:0% +well let me see I get my page a little +bit + + align:start position:0% + + + + align:start position:0% + +right okay yeah so so first we have to + + align:start position:0% +right okay yeah so so first we have to + + + align:start position:0% +right okay yeah so so first we have to +do a calculation we have to calculate + + align:start position:0% +do a calculation we have to calculate + + + align:start position:0% +do a calculation we have to calculate +this process okay + + align:start position:0% +this process okay + + + align:start position:0% +this process okay +so so uh so after we have calculating + + align:start position:0% +so so uh so after we have calculating + + + align:start position:0% +so so uh so after we have calculating +this then then it's obvious that how + + align:start position:0% +this then then it's obvious that how + + + align:start position:0% +this then then it's obvious that how +that the uh this can tell us why the + + align:start position:0% +that the uh this can tell us why the + + + align:start position:0% +that the uh this can tell us why the +clock has three colors okay + + align:start position:0% +clock has three colors okay + + + align:start position:0% +clock has three colors okay +okay yes + + align:start position:0% + + + + align:start position:0% + +yeah so so indeed for the so that's why + + align:start position:0% +yeah so so indeed for the so that's why + + + align:start position:0% +yeah so so indeed for the so that's why +for many years uh if you look at the + + align:start position:0% +for many years uh if you look at the + + + align:start position:0% +for many years uh if you look at the +proton the neutron and the pair they're + + align:start position:0% +proton the neutron and the pair they're + + + align:start position:0% +proton the neutron and the pair they're +very tightly bound and so so + + align:start position:0% +very tightly bound and so so + + + align:start position:0% +very tightly bound and so so +even though there were models about the + + align:start position:0% +even though there were models about the + + + align:start position:0% +even though there were models about the +clocks inside there so it's not quite uh + + align:start position:0% +clocks inside there so it's not quite uh + + + align:start position:0% +clocks inside there so it's not quite uh +uh yeah but but in the CKC a very uh + + align:start position:0% +uh yeah but but in the CKC a very uh + + + align:start position:0% +uh yeah but but in the CKC a very uh +heavy and so so they form a weekly Bond + + align:start position:0% +heavy and so so they form a weekly Bond + + + align:start position:0% +heavy and so so they form a weekly Bond +State and uh and so in the sense that + + align:start position:0% +State and uh and so in the sense that + + + align:start position:0% +State and uh and so in the sense that +you're looking at the uh uh yeah so here + + align:start position:0% +you're looking at the uh uh yeah so here + + + align:start position:0% +you're looking at the uh uh yeah so here +it's in the sense you can look at the C + + align:start position:0% +it's in the sense you can look at the C + + + align:start position:0% +it's in the sense you can look at the C +clock yeah yeah because it's a very + + align:start position:0% +clock yeah yeah because it's a very + + + align:start position:0% +clock yeah yeah because it's a very +weakly Bond state of the CNC one + + align:start position:0% + + + + align:start position:0% + +other questions + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +just say uh you can probe with the yeah + + align:start position:0% +just say uh you can probe with the yeah + + + align:start position:0% +just say uh you can probe with the yeah +you can essentially you can probe with + + align:start position:0% +you can essentially you can probe with + + + align:start position:0% +you can essentially you can probe with +the internal structure much easier + + align:start position:0% + + + + align:start position:0% + +this Village + + align:start position:0% + + + + align:start position:0% + +like the most important machine like + + align:start position:0% +like the most important machine like + + + align:start position:0% +like the most important machine like +yeah yeah it is quite big big election + + align:start position:0% +yeah yeah it is quite big big election + + + align:start position:0% +yeah yeah it is quite big big election +Crider is more difficult because you + + align:start position:0% +Crider is more difficult because you + + + align:start position:0% +Crider is more difficult because you +have to build a straight line + + align:start position:0% +have to build a straight line + + + align:start position:0% +have to build a straight line +and because the electron have a much + + align:start position:0% +and because the electron have a much + + + align:start position:0% +and because the electron have a much +stronger single Singleton radiation if + + align:start position:0% +stronger single Singleton radiation if + + + align:start position:0% +stronger single Singleton radiation if +they are moving in the circle and so + + align:start position:0% +they are moving in the circle and so + + + align:start position:0% +they are moving in the circle and so +that lose a lot of energy and so that's + + align:start position:0% +that lose a lot of energy and so that's + + + align:start position:0% +that lose a lot of energy and so that's +the inaction clitor they should build a + + align:start position:0% +the inaction clitor they should build a + + + align:start position:0% +the inaction clitor they should build a +strong a straight line but straight nine + + align:start position:0% +strong a straight line but straight nine + + + align:start position:0% +strong a straight line but straight nine +you cannot have very high energy a + + align:start position:0% +you cannot have very high energy a + + + align:start position:0% +you cannot have very high energy a +require very long distance + + align:start position:0% +require very long distance + + + align:start position:0% +require very long distance +so that's why uh normally people build + + align:start position:0% +so that's why uh normally people build + + + align:start position:0% +so that's why uh normally people build +they build the the proton glider + + align:start position:0% +they build the the proton glider + + + align:start position:0% +they build the the proton glider +is easier + + align:start position:0% +is easier + + + align:start position:0% +is easier +and yeah it's easier to to get higher + + align:start position:0% +and yeah it's easier to to get higher + + + align:start position:0% +and yeah it's easier to to get higher +energy + + align:start position:0% +energy + + + align:start position:0% +energy +and but but the last generation of the + + align:start position:0% +and but but the last generation of the + + + align:start position:0% +and but but the last generation of the +accelerator of the ahc people are + + align:start position:0% +accelerator of the ahc people are + + + align:start position:0% +accelerator of the ahc people are +talking about building an electron + + align:start position:0% +talking about building an electron + + + align:start position:0% +talking about building an electron +glider again yeah + + align:start position:0% +glider again yeah + + + align:start position:0% +glider again yeah +um yeah + + align:start position:0% + + + + align:start position:0% + +good so now let's try to calculate this + + align:start position:0% +good so now let's try to calculate this + + + align:start position:0% +good so now let's try to calculate this +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so and essentially we need to calculate + + align:start position:0% +so and essentially we need to calculate + + + align:start position:0% +so and essentially we need to calculate +this diagram + + align:start position:0% +this diagram + + + align:start position:0% +this diagram +and yeah this diagram is very easy we + + align:start position:0% +and yeah this diagram is very easy we + + + align:start position:0% +and yeah this diagram is very easy we +need to calculate the cross section + + align:start position:0% +need to calculate the cross section + + + align:start position:0% +need to calculate the cross section +corresponding to this so so let me just + + align:start position:0% +corresponding to this so so let me just + + + align:start position:0% +corresponding to this so so let me just +label our a label so this is e minus say + + align:start position:0% +label our a label so this is e minus say + + + align:start position:0% +label our a label so this is e minus say +this is e plus so this would be B and + + align:start position:0% +this is e plus so this would be B and + + + align:start position:0% +this is e plus so this would be B and +this will be P bar + + align:start position:0% +this will be P bar + + + align:start position:0% +this will be P bar +so let me enable the momentum so here + + align:start position:0% +so let me enable the momentum so here + + + align:start position:0% +so let me enable the momentum so here +let's take P1 R1 + + align:start position:0% +let's take P1 R1 + + + align:start position:0% +let's take P1 R1 +and then this would be P2 + + align:start position:0% +and then this would be P2 + + + align:start position:0% +and then this would be P2 +R2 bar + + align:start position:0% +R2 bar + + + align:start position:0% +R2 bar +so to tell you this is the antiparticle + + align:start position:0% +so to tell you this is the antiparticle + + + align:start position:0% +so to tell you this is the antiparticle +and so this one is k1 S1 + + align:start position:0% +and so this one is k1 S1 + + + align:start position:0% +and so this one is k1 S1 +and this one is K2 + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and so so the amplitude for this will be + + align:start position:0% +and so so the amplitude for this will be + + + align:start position:0% +and so so the amplitude for this will be +m + + align:start position:0% +m + + + align:start position:0% +m +but the cross section + + align:start position:0% + + + + align:start position:0% + +so so now suppose we consider + + align:start position:0% +so so now suppose we consider + + + align:start position:0% +so so now suppose we consider +unpolarized process + + align:start position:0% +unpolarized process + + + align:start position:0% +unpolarized process +as we discussed last time + + align:start position:0% +as we discussed last time + + + align:start position:0% +as we discussed last time +that the cross section + + align:start position:0% + + + + align:start position:0% + +yeah say the sigma the Omega should be + + align:start position:0% +yeah say the sigma the Omega should be + + + align:start position:0% +yeah say the sigma the Omega should be +proportional + + align:start position:0% +proportional + + + align:start position:0% +proportional +to + + align:start position:0% +to + + + align:start position:0% +to +the spin + + align:start position:0% +the spin + + + align:start position:0% +the spin +so we should + + align:start position:0% +so we should + + + align:start position:0% +so we should +sum over + + align:start position:0% +sum over + + + align:start position:0% +sum over +the value States sum over the + + align:start position:0% +the value States sum over the + + + align:start position:0% +the value States sum over the +presentation of the follow States + + align:start position:0% +presentation of the follow States + + + align:start position:0% +presentation of the follow States +because we don't measure individual + + align:start position:0% +because we don't measure individual + + + align:start position:0% +because we don't measure individual +prioritizations but we also should + + align:start position:0% +prioritizations but we also should + + + align:start position:0% +prioritizations but we also should +average over the polarization of the + + align:start position:0% +average over the polarization of the + + + align:start position:0% +average over the polarization of the +initial States + + align:start position:0% +initial States + + + align:start position:0% +initial States +so so so the result as we discussed at + + align:start position:0% +so so so the result as we discussed at + + + align:start position:0% +so so so the result as we discussed at +the end of last lecture you say you need + + align:start position:0% +the end of last lecture you say you need + + + align:start position:0% +the end of last lecture you say you need +to take one quarter count from the + + align:start position:0% +to take one quarter count from the + + + align:start position:0% +to take one quarter count from the +average over the spin + + align:start position:0% +average over the spin + + + align:start position:0% +average over the spin +so these two initial particles + + align:start position:0% +so these two initial particles + + + align:start position:0% +so these two initial particles +and and then + + align:start position:0% +and and then + + + align:start position:0% +and and then +the sum of spins of all the particles + + align:start position:0% +the sum of spins of all the particles + + + align:start position:0% +the sum of spins of all the particles +okay + + align:start position:0% + + + + align:start position:0% + +okay and uh uh uh um + + align:start position:0% +okay and uh uh uh um + + + align:start position:0% +okay and uh uh uh um +right + + align:start position:0% +right + + + align:start position:0% +right +um okay so so so so so that's the thing + + align:start position:0% +um okay so so so so so that's the thing + + + align:start position:0% +um okay so so so so so that's the thing +we need to so let's just try to First + + align:start position:0% +we need to so let's just try to First + + + align:start position:0% +we need to so let's just try to First +compute the m + + align:start position:0% +compute the m + + + align:start position:0% +compute the m +so m + + align:start position:0% + + + + align:start position:0% + +is given by + + align:start position:0% +is given by + + + align:start position:0% +is given by +okay so we just follow our rule + + align:start position:0% +okay so we just follow our rule + + + align:start position:0% +okay so we just follow our rule +so you look you follow the formionic + + align:start position:0% +so you look you follow the formionic + + + align:start position:0% +so you look you follow the formionic +line + + align:start position:0% +line + + + align:start position:0% +line +okay so so here there's a vertex + + align:start position:0% +okay so so here there's a vertex + + + align:start position:0% +okay so so here there's a vertex +so here there's a gamma + + align:start position:0% +so here there's a gamma + + + align:start position:0% +so here there's a gamma +so each vertex gives you a minus i e + + align:start position:0% +so each vertex gives you a minus i e + + + align:start position:0% +so each vertex gives you a minus i e +comma mu okay + + align:start position:0% +comma mu okay + + + align:start position:0% +comma mu okay +so if you follow this one okay then we + + align:start position:0% +so if you follow this one okay then we + + + align:start position:0% +so if you follow this one okay then we +get + + align:start position:0% + + + + align:start position:0% + +V bar + + align:start position:0% + + + + align:start position:0% + +R2 + + align:start position:0% +R2 + + + align:start position:0% +R2 +P2 + + align:start position:0% +P2 + + + align:start position:0% +P2 +the minus IE gamma mu + + align:start position:0% +the minus IE gamma mu + + + align:start position:0% +the minus IE gamma mu +and U R1 P1 okay + + align:start position:0% +and U R1 P1 okay + + + align:start position:0% +and U R1 P1 okay +so this is coming from this + + align:start position:0% + + + + align:start position:0% + + + align:start position:0% + + + align:start position:0% +we start from here + + align:start position:0% +we start from here + + + align:start position:0% +we start from here +so this would be the um + + align:start position:0% +so this would be the um + + + align:start position:0% +so this would be the um +the U yeah yeah also we have this + + align:start position:0% +the U yeah yeah also we have this + + + align:start position:0% +the U yeah yeah also we have this +propagator let me just write down the + + align:start position:0% +propagator let me just write down the + + + align:start position:0% +propagator let me just write down the +propagator + + align:start position:0% +propagator + + + align:start position:0% +propagator +for the photon + + align:start position:0% +for the photon + + + align:start position:0% +for the photon +so let's take PSI equal to 1 h + + align:start position:0% +so let's take PSI equal to 1 h + + + align:start position:0% +so let's take PSI equal to 1 h +colon the larynx cage with PSI equal to + + align:start position:0% +colon the larynx cage with PSI equal to + + + align:start position:0% +colon the larynx cage with PSI equal to +one + + align:start position:0% +one + + + align:start position:0% +one +and then and then it follows this nine + + align:start position:0% +and then and then it follows this nine + + + align:start position:0% +and then and then it follows this nine +so here + + align:start position:0% + + + + align:start position:0% + +okay and then we will have + + align:start position:0% +okay and then we will have + + + align:start position:0% +okay and then we will have +U Bar as one + + align:start position:0% +U Bar as one + + + align:start position:0% +U Bar as one +K1 + + align:start position:0% +K1 + + + align:start position:0% +K1 +and minus IE comma Nu + + align:start position:0% + + + + align:start position:0% + +V S2 + + align:start position:0% + + + + align:start position:0% + +K2 + + align:start position:0% +K2 + + + align:start position:0% +K2 +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so this is the full amplitude + + align:start position:0% +so this is the full amplitude + + + align:start position:0% +so this is the full amplitude +so + + align:start position:0% +so + + + align:start position:0% +so +so this is a lumber + + align:start position:0% +so this is a lumber + + + align:start position:0% +so this is a lumber +okay so this is a number because this is + + align:start position:0% +okay so this is a number because this is + + + align:start position:0% +okay so this is a number because this is +a row vector + + align:start position:0% +a row vector + + + align:start position:0% +a row vector +this is a matrix and this is a column + + align:start position:0% +this is a matrix and this is a column + + + align:start position:0% +this is a matrix and this is a column +Vector okay so this will be a number and + + align:start position:0% +Vector okay so this will be a number and + + + align:start position:0% +Vector okay so this will be a number and +similarly this will be a number and then + + align:start position:0% +similarly this will be a number and then + + + align:start position:0% +similarly this will be a number and then +the MU Nu in this is a contraction with + + align:start position:0% +the MU Nu in this is a contraction with + + + align:start position:0% +the MU Nu in this is a contraction with +the propagator of the photon okay + + align:start position:0% + + + + align:start position:0% + +so actually uh if I want to be precise + + align:start position:0% +so actually uh if I want to be precise + + + align:start position:0% +so actually uh if I want to be precise +there's actually a factor of I here okay + + align:start position:0% +there's actually a factor of I here okay + + + align:start position:0% +there's actually a factor of I here okay +yeah but but this Factor Y is not + + align:start position:0% +yeah but but this Factor Y is not + + + align:start position:0% +yeah but but this Factor Y is not +important because + + align:start position:0% +important because + + + align:start position:0% +important because +and then the queue + + align:start position:0% +and then the queue + + + align:start position:0% +and then the queue +so the Q is the momentum of the photon + + align:start position:0% +so the Q is the momentum of the photon + + + align:start position:0% +so the Q is the momentum of the photon +here + + align:start position:0% +here + + + align:start position:0% +here +so the Q should be the sum of the + + align:start position:0% +so the Q should be the sum of the + + + align:start position:0% +so the Q should be the sum of the +initial momentum okay so Q + + align:start position:0% +initial momentum okay so Q + + + align:start position:0% +initial momentum okay so Q +is the + + align:start position:0% +is the + + + align:start position:0% +is the +should be equal to P1 plus P2 + + align:start position:0% +should be equal to P1 plus P2 + + + align:start position:0% +should be equal to P1 plus P2 +and also this means that the Q Square + + align:start position:0% +and also this means that the Q Square + + + align:start position:0% +and also this means that the Q Square +is equal to minus s + + align:start position:0% +is equal to minus s + + + align:start position:0% +is equal to minus s +okay remember s is defined to be the + + align:start position:0% +okay remember s is defined to be the + + + align:start position:0% +okay remember s is defined to be the +minus P1 plus P2 Square + + align:start position:0% +minus P1 plus P2 Square + + + align:start position:0% +minus P1 plus P2 Square +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so now we can write this + + align:start position:0% +so now we can write this + + + align:start position:0% +so now we can write this +amplitude using the shorthand location + + align:start position:0% +amplitude using the shorthand location + + + align:start position:0% +amplitude using the shorthand location +so so if I forget all these momentum + + align:start position:0% +so so if I forget all these momentum + + + align:start position:0% +so so if I forget all these momentum +dependence and then this is + + align:start position:0% +dependence and then this is + + + align:start position:0% +dependence and then this is +equal to + + align:start position:0% +equal to + + + align:start position:0% +equal to +minus IE Square + + align:start position:0% +minus IE Square + + + align:start position:0% +minus IE Square +divided by S okay if you cancel all the + + align:start position:0% +divided by S okay if you cancel all the + + + align:start position:0% +divided by S okay if you cancel all the +I's and then we have two terms V bar R2 + + align:start position:0% +I's and then we have two terms V bar R2 + + + align:start position:0% +I's and then we have two terms V bar R2 +comma Nu + + align:start position:0% +comma Nu + + + align:start position:0% +comma Nu +and U are one + + align:start position:0% +and U are one + + + align:start position:0% +and U are one +and the U Bar S1 comma Nu + + align:start position:0% + + + + align:start position:0% + +b s cubed + + align:start position:0% +b s cubed + + + align:start position:0% +b s cubed +okay + + align:start position:0% + + + + align:start position:0% + +and now we need to + + align:start position:0% +and now we need to + + + align:start position:0% +and now we need to +um + + align:start position:0% +um + + + align:start position:0% +um +then what we need to do is we do to + + align:start position:0% +then what we need to do is we do to + + + align:start position:0% +then what we need to do is we do to +square it + + align:start position:0% +square it + + + align:start position:0% +square it +and sum over all the spin + + align:start position:0% +and sum over all the spin + + + align:start position:0% +and sum over all the spin +and then we plug then we plug the + + align:start position:0% +and then we plug then we plug the + + + align:start position:0% +and then we plug then we plug the +resulting expression into the formula we + + align:start position:0% +resulting expression into the formula we + + + align:start position:0% +resulting expression into the formula we +derived for the cross-section V uh + + align:start position:0% +derived for the cross-section V uh + + + align:start position:0% +derived for the cross-section V uh +derived last time okay + + align:start position:0% +derived last time okay + + + align:start position:0% +derived last time okay +so uh uh so the so the whole calculation + + align:start position:0% +so uh uh so the so the whole calculation + + + align:start position:0% +so uh uh so the so the whole calculation +is a little bit tedious okay but but I + + align:start position:0% +is a little bit tedious okay but but I + + + align:start position:0% +is a little bit tedious okay but but I +think we should at least go through one + + align:start position:0% +think we should at least go through one + + + align:start position:0% +think we should at least go through one +such calculation + + align:start position:0% +such calculation + + + align:start position:0% +such calculation +because this is the uh + + align:start position:0% +because this is the uh + + + align:start position:0% +because this is the uh +kind of + + align:start position:0% +kind of + + + align:start position:0% +kind of +uh um yeah prime example okay of QED + + align:start position:0% +uh um yeah prime example okay of QED + + + align:start position:0% +uh um yeah prime example okay of QED +calculation so so each of us should at + + align:start position:0% +calculation so so each of us should at + + + align:start position:0% +calculation so so each of us should at +least see + + align:start position:0% +least see + + + align:start position:0% +least see +once in our life okay so so we will do + + align:start position:0% +once in our life okay so so we will do + + + align:start position:0% +once in our life okay so so we will do +it explicitly here + + align:start position:0% + + + + align:start position:0% + +hmm + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% + + + + align:start position:0% + +oh okay yeah yeah also uh uh uh uh here + + align:start position:0% +oh okay yeah yeah also uh uh uh uh here + + + align:start position:0% +oh okay yeah yeah also uh uh uh uh here +because the Q square is never equal to + + align:start position:0% +because the Q square is never equal to + + + align:start position:0% +because the Q square is never equal to +zero and so we don't need to care about + + align:start position:0% +zero and so we don't need to care about + + + align:start position:0% +zero and so we don't need to care about +as + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +good + + align:start position:0% +good + + + align:start position:0% +good +so now let's do the square + + align:start position:0% + + + + align:start position:0% + +now let's do the square + + align:start position:0% + + + + align:start position:0% + +so Square we just Square this term and + + align:start position:0% +so Square we just Square this term and + + + align:start position:0% +so Square we just Square this term and +square this term okay + + align:start position:0% +square this term okay + + + align:start position:0% +square this term okay +so when we Square this term + + align:start position:0% + + + + align:start position:0% + +so so we also Square this term so here + + align:start position:0% +so so we also Square this term so here + + + align:start position:0% +so so we also Square this term so here +we just get the e to the power 4 divided + + align:start position:0% +we just get the e to the power 4 divided + + + align:start position:0% +we just get the e to the power 4 divided +by S Square + + align:start position:0% +by S Square + + + align:start position:0% +by S Square +and when we Square this term + + align:start position:0% + + + + align:start position:0% + +we just get another uh yeah so + + align:start position:0% +we just get another uh yeah so + + + align:start position:0% +we just get another uh yeah so +so this is gamma Nu comma mu so we if we + + align:start position:0% +so this is gamma Nu comma mu so we if we + + + align:start position:0% +so this is gamma Nu comma mu so we if we +Square it then we get another term + + align:start position:0% +Square it then we get another term + + + align:start position:0% +Square it then we get another term +okay so so we just copy this term + + align:start position:0% + + + + align:start position:0% + +yeah let me just copy here + + align:start position:0% + + + + align:start position:0% + +you are one + + align:start position:0% +you are one + + + align:start position:0% +you are one +um + + align:start position:0% +um + + + align:start position:0% +um +yeah when we scaled we get a lot of copy + + align:start position:0% +yeah when we scaled we get a lot of copy + + + align:start position:0% +yeah when we scaled we get a lot of copy +of this and so let me just write it + + align:start position:0% + + + + align:start position:0% + +yeah sorry + + align:start position:0% +yeah sorry + + + align:start position:0% +yeah sorry +so + + align:start position:0% +so + + + align:start position:0% +so +so we take the compressed conjugate okay + + align:start position:0% +so we take the compressed conjugate okay + + + align:start position:0% +so we take the compressed conjugate okay +so when we take the complex we need to + + align:start position:0% +so when we take the complex we need to + + + align:start position:0% +so when we take the complex we need to +take the modulus that means we need to + + align:start position:0% +take the modulus that means we need to + + + align:start position:0% +take the modulus that means we need to +multiply this + + align:start position:0% +multiply this + + + align:start position:0% +multiply this +which is on compressed conjugates okay + + align:start position:0% +which is on compressed conjugates okay + + + align:start position:0% +which is on compressed conjugates okay +and the complex conjugate of these + + align:start position:0% +and the complex conjugate of these + + + align:start position:0% +and the complex conjugate of these +is given by U Bar R1 + + align:start position:0% +is given by U Bar R1 + + + align:start position:0% +is given by U Bar R1 +then comma Nu + + align:start position:0% + + + + align:start position:0% + +and VR2 + + align:start position:0% +and VR2 + + + align:start position:0% +and VR2 +and then times + + align:start position:0% +and then times + + + align:start position:0% +and then times +this one and its times + + align:start position:0% +this one and its times + + + align:start position:0% +this one and its times +its compressed conjugate and so we have + + align:start position:0% +its compressed conjugate and so we have + + + align:start position:0% +its compressed conjugate and so we have +u s one bar + + align:start position:0% +u s one bar + + + align:start position:0% +u s one bar +common view + + align:start position:0% +common view + + + align:start position:0% +common view +vs2 + + align:start position:0% +vs2 + + + align:start position:0% +vs2 +and vs2 Bar + + align:start position:0% +and vs2 Bar + + + align:start position:0% +and vs2 Bar +comma Nu + + align:start position:0% + + + + align:start position:0% + +S1 Okay so + + align:start position:0% +S1 Okay so + + + align:start position:0% +S1 Okay so +so this is original copy + + align:start position:0% +so this is original copy + + + align:start position:0% +so this is original copy +with the build contracts with this new + + align:start position:0% +with the build contracts with this new + + + align:start position:0% +with the build contracts with this new +and this is a complex conjugate with + + align:start position:0% +and this is a complex conjugate with + + + align:start position:0% +and this is a complex conjugate with +this new contract with this new okay + + align:start position:0% + + + + align:start position:0% + +good + + align:start position:0% + + + + align:start position:0% + +so this looks like a mass + + align:start position:0% +so this looks like a mass + + + align:start position:0% +so this looks like a mass +okay this is nuclex the big Mass + + align:start position:0% +okay this is nuclex the big Mass + + + align:start position:0% +okay this is nuclex the big Mass +and the 1000 actually there's a a series + + align:start position:0% +and the 1000 actually there's a a series + + + align:start position:0% +and the 1000 actually there's a a series +of beautiful tricks we can use to + + align:start position:0% +of beautiful tricks we can use to + + + align:start position:0% +of beautiful tricks we can use to +calculate this quantity okay so solidity + + align:start position:0% +calculate this quantity okay so solidity + + + align:start position:0% +calculate this quantity okay so solidity +you say oh + + align:start position:0% +you say oh + + + align:start position:0% +you say oh +to calculate this thing I have to plug + + align:start position:0% +to calculate this thing I have to plug + + + align:start position:0% +to calculate this thing I have to plug +in the individual + + align:start position:0% +in the individual + + + align:start position:0% +in the individual +wave functions for this uh V and U Etc + + align:start position:0% +wave functions for this uh V and U Etc + + + align:start position:0% +wave functions for this uh V and U Etc +okay we we worked out before but + + align:start position:0% +okay we we worked out before but + + + align:start position:0% +okay we we worked out before but +fortunately actually you don't need to + + align:start position:0% +fortunately actually you don't need to + + + align:start position:0% +fortunately actually you don't need to +do it okay so so we can actually go + + align:start position:0% +do it okay so so we can actually go + + + align:start position:0% +do it okay so so we can actually go +through a a series tricks and that we + + align:start position:0% +through a a series tricks and that we + + + align:start position:0% +through a a series tricks and that we +don't have to do it + + align:start position:0% +don't have to do it + + + align:start position:0% +don't have to do it +so the first trick + + align:start position:0% + + + + align:start position:0% + +is that this is a number + + align:start position:0% +is that this is a number + + + align:start position:0% +is that this is a number +okay since this is a number + + align:start position:0% +okay since this is a number + + + align:start position:0% +okay since this is a number +I can put the trace outside of it okay + + align:start position:0% + + + + align:start position:0% + +because the trace of a number is just a + + align:start position:0% +because the trace of a number is just a + + + align:start position:0% +because the trace of a number is just a +number + + align:start position:0% +number + + + align:start position:0% +number +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and now if you now remember the trades + + align:start position:0% +and now if you now remember the trades + + + align:start position:0% +and now if you now remember the trades +have this cyclic properties + + align:start position:0% +have this cyclic properties + + + align:start position:0% +have this cyclic properties +okay so it's a recycling property so I + + align:start position:0% +okay so it's a recycling property so I + + + align:start position:0% +okay so it's a recycling property so I +can actually move this + + align:start position:0% +can actually move this + + + align:start position:0% +can actually move this +to there okay so so I can move it + + align:start position:0% +to there okay so so I can move it + + + align:start position:0% +to there okay so so I can move it +so so now I can write it as equal to 4 S + + align:start position:0% +so so now I can write it as equal to 4 S + + + align:start position:0% +so so now I can write it as equal to 4 S +Square + + align:start position:0% + + + + align:start position:0% + +I can just move this to this so that the + + align:start position:0% +I can just move this to this so that the + + + align:start position:0% +I can just move this to this so that the +two R2 come together okay so if you have + + align:start position:0% +two R2 come together okay so if you have + + + align:start position:0% +two R2 come together okay so if you have +a v r Cube + + align:start position:0% +a v r Cube + + + align:start position:0% +a v r Cube +V bar R2 + + align:start position:0% +V bar R2 + + + align:start position:0% +V bar R2 +R2 comma mu + + align:start position:0% +R2 comma mu + + + align:start position:0% +R2 comma mu +and U R1 U power R1 + + align:start position:0% +and U R1 U power R1 + + + align:start position:0% +and U R1 U power R1 +times + + align:start position:0% + + + + align:start position:0% + +similarly I put this us to the other + + align:start position:0% +similarly I put this us to the other + + + align:start position:0% +similarly I put this us to the other +side US1 + + align:start position:0% +side US1 + + + align:start position:0% +side US1 +if r s one + + align:start position:0% +if r s one + + + align:start position:0% +if r s one +comma mu + + align:start position:0% +comma mu + + + align:start position:0% +comma mu +sorry I missed + + align:start position:0% +sorry I missed + + + align:start position:0% +sorry I missed +use the Gamma New + + align:start position:0% + + + + align:start position:0% + +sorry did I + + align:start position:0% +sorry did I + + + align:start position:0% +sorry did I +so I put this oh sorry no no + + align:start position:0% +so I put this oh sorry no no + + + align:start position:0% +so I put this oh sorry no no +sorry I just missed that one + + align:start position:0% +sorry I just missed that one + + + align:start position:0% +sorry I just missed that one +bar R1 comma nuke + + align:start position:0% +bar R1 comma nuke + + + align:start position:0% +bar R1 comma nuke +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and it's similarly with that so so I + + align:start position:0% +and it's similarly with that so so I + + + align:start position:0% +and it's similarly with that so so I +have U Bar is one command + + align:start position:0% +have U Bar is one command + + + align:start position:0% +have U Bar is one command +mu + + align:start position:0% +mu + + + align:start position:0% +mu +and then we have vs2 + + align:start position:0% + + + + align:start position:0% + +V bar is two + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +so I guess that + + align:start position:0% +so I guess that + + + align:start position:0% +so I guess that +so the reason I do that + + align:start position:0% +so the reason I do that + + + align:start position:0% +so the reason I do that +so so now in this form now this is a + + align:start position:0% +so so now in this form now this is a + + + align:start position:0% +so so now in this form now this is a +matrix + + align:start position:0% +matrix + + + align:start position:0% +matrix +okay now this is a now this is a column + + align:start position:0% +okay now this is a now this is a column + + + align:start position:0% +okay now this is a now this is a column +this is a row + + align:start position:0% +this is a row + + + align:start position:0% +this is a row +and this is a matrix and this is column + + align:start position:0% +and this is a matrix and this is column + + + align:start position:0% +and this is a matrix and this is column +and this is row so so this is a matrix + + align:start position:0% +and this is row so so this is a matrix + + + align:start position:0% +and this is row so so this is a matrix +times a matrix and times a matrix and + + align:start position:0% +times a matrix and times a matrix and + + + align:start position:0% +times a matrix and times a matrix and +times a matrix okay and then you take + + align:start position:0% +times a matrix okay and then you take + + + align:start position:0% +times a matrix okay and then you take +the trace and then you get number okay + + align:start position:0% +the trace and then you get number okay + + + align:start position:0% +the trace and then you get number okay +similarly with things here + + align:start position:0% + + + + align:start position:0% + +and then we need to sum over all the + + align:start position:0% +and then we need to sum over all the + + + align:start position:0% +and then we need to sum over all the +spins okay remember we did actually when + + align:start position:0% +spins okay remember we did actually when + + + align:start position:0% +spins okay remember we did actually when +we sum all the spins we means we sum + + align:start position:0% +we sum all the spins we means we sum + + + align:start position:0% +we sum all the spins we means we sum +over all possible with some other R2 R1 + + align:start position:0% +over all possible with some other R2 R1 + + + align:start position:0% +over all possible with some other R2 R1 +S1 and S2 okay + + align:start position:0% +S1 and S2 okay + + + align:start position:0% +S1 and S2 okay +so now we can use a trick which we uh we + + align:start position:0% +so now we can use a trick which we uh we + + + align:start position:0% +so now we can use a trick which we uh we +had when we discussed the direct + + align:start position:0% +had when we discussed the direct + + + align:start position:0% +had when we discussed the direct +Spinners okay so now recall + + align:start position:0% + + + + align:start position:0% + +now recall + + align:start position:0% +now recall + + + align:start position:0% +now recall +for unshare spinners + + align:start position:0% + + + + align:start position:0% + +means don't satisfy the equation motion + + align:start position:0% +means don't satisfy the equation motion + + + align:start position:0% +means don't satisfy the equation motion +okay those all the unshell spindles okay + + align:start position:0% + + + + align:start position:0% + +they satisfy the following sum over R if + + align:start position:0% +they satisfy the following sum over R if + + + align:start position:0% +they satisfy the following sum over R if +you sum over all the r of the U + + align:start position:0% +you sum over all the r of the U + + + align:start position:0% +you sum over all the r of the U +u r p + + align:start position:0% + + + + align:start position:0% + +u r bar p + + align:start position:0% +u r bar p + + + align:start position:0% +u r bar p +that give you I I P slash plus m + + align:start position:0% +that give you I I P slash plus m + + + align:start position:0% +that give you I I P slash plus m +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and when you sum over V + + align:start position:0% + + + + align:start position:0% + +with the minus I minus is + + align:start position:0% +with the minus I minus is + + + align:start position:0% +with the minus I minus is +okay + + align:start position:0% + + + + align:start position:0% + +so so now we can now we see we have if + + align:start position:0% +so so now we can now we see we have if + + + align:start position:0% +so so now we can now we see we have if +we sum over spin then we have these + + align:start position:0% +we sum over spin then we have these + + + align:start position:0% +we sum over spin then we have these +combinations + + align:start position:0% +combinations + + + align:start position:0% +combinations +now we can use those formulas okay now + + align:start position:0% +now we can use those formulas okay now + + + align:start position:0% +now we can use those formulas okay now +we can use those formulas + + align:start position:0% +we can use those formulas + + + align:start position:0% +we can use those formulas +so now we find + + align:start position:0% +so now we find + + + align:start position:0% +so now we find +one quarter + + align:start position:0% +one quarter + + + align:start position:0% +one quarter +when we sum all the all the indices + + align:start position:0% +when we sum all the all the indices + + + align:start position:0% +when we sum all the all the indices +R1 R2 S1 S2 + + align:start position:0% + + + + align:start position:0% + +the M Square + + align:start position:0% + + + + align:start position:0% + +you get + + align:start position:0% +you get + + + align:start position:0% +you get +then we just get the uh + + align:start position:0% +then we just get the uh + + + align:start position:0% +then we just get the uh +um + + align:start position:0% +um + + + align:start position:0% +um +so we get E4 + + align:start position:0% +so we get E4 + + + align:start position:0% +so we get E4 +divided by 4s squared + + align:start position:0% +divided by 4s squared + + + align:start position:0% +divided by 4s squared +and then we just + + align:start position:0% +and then we just + + + align:start position:0% +and then we just +apply those formulas into here okay so + + align:start position:0% +apply those formulas into here okay so + + + align:start position:0% +apply those formulas into here okay so +we get + + align:start position:0% +we get + + + align:start position:0% +we get +Trace + + align:start position:0% + + + + align:start position:0% + +minus I P2 slash + + align:start position:0% +minus I P2 slash + + + align:start position:0% +minus I P2 slash +plus m + + align:start position:0% + + + + align:start position:0% + +so m is the mass of the initial particle + + align:start position:0% +so m is the mass of the initial particle + + + align:start position:0% +so m is the mass of the initial particle +and I take the M Prime of the particle + + align:start position:0% +and I take the M Prime of the particle + + + align:start position:0% +and I take the M Prime of the particle +mass of the fellow particle + + align:start position:0% +mass of the fellow particle + + + align:start position:0% +mass of the fellow particle +so the + + align:start position:0% +so the + + + align:start position:0% +so the +so the E plus minus of mass m and b + + align:start position:0% +so the E plus minus of mass m and b + + + align:start position:0% +so the E plus minus of mass m and b +okay + + align:start position:0% + + + + align:start position:0% + +so then I have this then this times + + align:start position:0% + + + + align:start position:0% + +then this comma mu + + align:start position:0% + + + + align:start position:0% + +and so this is still inside this bracket + + align:start position:0% + + + + align:start position:0% + +ip1 slash plus m + + align:start position:0% +ip1 slash plus m + + + align:start position:0% +ip1 slash plus m +comma Nu + + align:start position:0% + + + + align:start position:0% + +and then I have Trace + + align:start position:0% + + + + align:start position:0% + +ik1 smash + + align:start position:0% +ik1 smash + + + align:start position:0% +ik1 smash +plus M Prime + + align:start position:0% +plus M Prime + + + align:start position:0% +plus M Prime +gamma + + align:start position:0% +gamma + + + align:start position:0% +gamma +mu + + align:start position:0% +mu + + + align:start position:0% +mu +and the minus I K2 + + align:start position:0% +and the minus I K2 + + + align:start position:0% +and the minus I K2 +slash plus M Prime + + align:start position:0% +slash plus M Prime + + + align:start position:0% +slash plus M Prime +U + + align:start position:0% +U + + + align:start position:0% +U +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so I just when I do this so the spin sum + + align:start position:0% +so I just when I do this so the spin sum + + + align:start position:0% +so I just when I do this so the spin sum +is crucial okay for this simplification + + align:start position:0% +is crucial okay for this simplification + + + align:start position:0% +is crucial okay for this simplification +when I sum over spins + + align:start position:0% +when I sum over spins + + + align:start position:0% +when I sum over spins +and then without using + + align:start position:0% +and then without using + + + align:start position:0% +and then without using +explicit expression of those uh u and v + + align:start position:0% +explicit expression of those uh u and v + + + align:start position:0% +explicit expression of those uh u and v +we can write all of them just in terms + + align:start position:0% +we can write all of them just in terms + + + align:start position:0% +we can write all of them just in terms +of P slash and the K slash Etc okay + + align:start position:0% + + + + align:start position:0% + +any questions on this + + align:start position:0% +any questions on this + + + align:start position:0% +any questions on this +and now we can evaluate the trace + + align:start position:0% +and now we can evaluate the trace + + + align:start position:0% +and now we can evaluate the trace +okay so imagine the trace + + align:start position:0% +okay so imagine the trace + + + align:start position:0% +okay so imagine the trace +now we need to use the wireless formula + + align:start position:0% +now we need to use the wireless formula + + + align:start position:0% +now we need to use the wireless formula +I think some of them we have done in + + align:start position:0% +I think some of them we have done in + + + align:start position:0% +I think some of them we have done in +your preset + + align:start position:0% +your preset + + + align:start position:0% +your preset +he said now recall + + align:start position:0% +he said now recall + + + align:start position:0% +he said now recall +so this is the place all those + + align:start position:0% +so this is the place all those + + + align:start position:0% +so this is the place all those +exercises they become useful + + align:start position:0% +exercises they become useful + + + align:start position:0% +exercises they become useful +so comma mu so here yeah if you look at + + align:start position:0% +so comma mu so here yeah if you look at + + + align:start position:0% +so comma mu so here yeah if you look at +the structure of these terms + + align:start position:0% +the structure of these terms + + + align:start position:0% +the structure of these terms +so here this is p slash so there's one + + align:start position:0% +so here this is p slash so there's one + + + align:start position:0% +so here this is p slash so there's one +gamma Matrix here + + align:start position:0% +gamma Matrix here + + + align:start position:0% +gamma Matrix here +and there's another gamma Matrix here + + align:start position:0% +and there's another gamma Matrix here + + + align:start position:0% +and there's another gamma Matrix here +and here p is actually the gamma Matrix + + align:start position:0% +and here p is actually the gamma Matrix + + + align:start position:0% +and here p is actually the gamma Matrix +here there's another gamma Matrix so at + + align:start position:0% +here there's another gamma Matrix so at + + + align:start position:0% +here there's another gamma Matrix so at +the most we can have the product of the + + align:start position:0% +the most we can have the product of the + + + align:start position:0% +the most we can have the product of the +four gamma matrices inside the trace + + align:start position:0% +four gamma matrices inside the trace + + + align:start position:0% +four gamma matrices inside the trace +and also depend on the product we can + + align:start position:0% +and also depend on the product we can + + + align:start position:0% +and also depend on the product we can +have four + + align:start position:0% +have four + + + align:start position:0% +have four +three and two okay uh three and two + + align:start position:0% +three and two okay uh three and two + + + align:start position:0% +three and two okay uh three and two +so so we need to uh for this purpose we + + align:start position:0% +so so we need to uh for this purpose we + + + align:start position:0% +so so we need to uh for this purpose we +lead to the uh those formulas + + align:start position:0% + + + + align:start position:0% + +what are the product of the form + + align:start position:0% +what are the product of the form + + + align:start position:0% +what are the product of the form +government Matrix is inside the integral + + align:start position:0% +government Matrix is inside the integral + + + align:start position:0% +government Matrix is inside the integral +so so this is just given by + + align:start position:0% +so so this is just given by + + + align:start position:0% +so so this is just given by +it's a mule + + align:start position:0% +it's a mule + + + align:start position:0% +it's a mule +need a number row + + align:start position:0% +need a number row + + + align:start position:0% +need a number row +Plus + + align:start position:0% + + + + align:start position:0% + +zero + + align:start position:0% +zero + + + align:start position:0% +zero +it's a new Lambda + + align:start position:0% +it's a new Lambda + + + align:start position:0% +it's a new Lambda +Madness + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +and also if you have three gamma + + align:start position:0% +and also if you have three gamma + + + align:start position:0% +and also if you have three gamma +matrices + + align:start position:0% + + + + align:start position:0% + +do you know the answer + + align:start position:0% + + + + align:start position:0% + +yes + + align:start position:0% +yes + + + align:start position:0% +yes +good and if I have two gamma matrices + + align:start position:0% + + + + align:start position:0% + +do you know what is this + + align:start position:0% + + + + align:start position:0% + +that's right it's four years + + align:start position:0% +that's right it's four years + + + align:start position:0% +that's right it's four years +okay so you can just apply those + + align:start position:0% +okay so you can just apply those + + + align:start position:0% +okay so you can just apply those +formulas to here + + align:start position:0% +formulas to here + + + align:start position:0% +formulas to here +okay so I will not + + align:start position:0% +okay so I will not + + + align:start position:0% +okay so I will not +do the calculation explicitly + + align:start position:0% +do the calculation explicitly + + + align:start position:0% +do the calculation explicitly +so you can just + + align:start position:0% +so you can just + + + align:start position:0% +so you can just +plug them in + + align:start position:0% +plug them in + + + align:start position:0% +plug them in +and then then it's mechanical you can + + align:start position:0% +and then then it's mechanical you can + + + align:start position:0% +and then then it's mechanical you can +just calculate it + + align:start position:0% +just calculate it + + + align:start position:0% +just calculate it +and then you find + + align:start position:0% +and then you find + + + align:start position:0% +and then you find +one over four + + align:start position:0% +one over four + + + align:start position:0% +one over four +sum over spin + + align:start position:0% + + + + align:start position:0% + +M Square + + align:start position:0% +M Square + + + align:start position:0% +M Square +is equal to let me write down the answer + + align:start position:0% +is equal to let me write down the answer + + + align:start position:0% +is equal to let me write down the answer +so even though this answer is slightly + + align:start position:0% +so even though this answer is slightly + + + align:start position:0% +so even though this answer is slightly +long but I think it's instructive to + + align:start position:0% +long but I think it's instructive to + + + align:start position:0% +long but I think it's instructive to +write it down so that you see it so if + + align:start position:0% +write it down so that you see it so if + + + align:start position:0% +write it down so that you see it so if +you when you plug all this in + + align:start position:0% +you when you plug all this in + + + align:start position:0% +you when you plug all this in +and the to the algebra + + align:start position:0% +and the to the algebra + + + align:start position:0% +and the to the algebra +and you find that the expression can be + + align:start position:0% +and you find that the expression can be + + + align:start position:0% +and you find that the expression can be +written as this + + align:start position:0% + + + + align:start position:0% + +K1 dot p + + align:start position:0% +K1 dot p + + + align:start position:0% +K1 dot p +one + + align:start position:0% +one + + + align:start position:0% +one +K2 dot P2 + + align:start position:0% +K2 dot P2 + + + align:start position:0% +K2 dot P2 +Plus + + align:start position:0% +Plus + + + align:start position:0% +Plus +P1 dot K2 + + align:start position:0% +P1 dot K2 + + + align:start position:0% +P1 dot K2 +and PQ dot K1 + + align:start position:0% +and PQ dot K1 + + + align:start position:0% +and PQ dot K1 +the minus + + align:start position:0% +the minus + + + align:start position:0% +the minus +M Square + + align:start position:0% +M Square + + + align:start position:0% +M Square +K1 dot KQ + + align:start position:0% + + + + align:start position:0% + +minus M squared + + align:start position:0% +minus M squared + + + align:start position:0% +minus M squared +P1 dot P2 + + align:start position:0% +P1 dot P2 + + + align:start position:0% +P1 dot P2 +M Prime squared sorry here should be M + + align:start position:0% +M Prime squared sorry here should be M + + + align:start position:0% +M Prime squared sorry here should be M +Times Square + + align:start position:0% + + + + align:start position:0% + +plus 2m Square + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +so we discussed before + + align:start position:0% + + + + align:start position:0% + +that the uh the amplitude Square must be + + align:start position:0% +that the uh the amplitude Square must be + + + align:start position:0% +that the uh the amplitude Square must be +a low end scalar + + align:start position:0% + + + + align:start position:0% + +scalar and so you see it explicitly here + + align:start position:0% +scalar and so you see it explicitly here + + + align:start position:0% +scalar and so you see it explicitly here +so it only involves either M square m + + align:start position:0% +so it only involves either M square m + + + align:start position:0% +so it only involves either M square m +Prime square or the product third + + align:start position:0% +Prime square or the product third + + + align:start position:0% +Prime square or the product third +product of initial and final momentum + + align:start position:0% +product of initial and final momentum + + + align:start position:0% +product of initial and final momentum +okay and uh you see all kind of + + align:start position:0% +okay and uh you see all kind of + + + align:start position:0% +okay and uh you see all kind of +combination of the uh initial and final + + align:start position:0% +combination of the uh initial and final + + + align:start position:0% +combination of the uh initial and final +momentum appearing here + + align:start position:0% +momentum appearing here + + + align:start position:0% +momentum appearing here +and now + + align:start position:0% +and now + + + align:start position:0% +and now +so it's convention + + align:start position:0% +so it's convention + + + align:start position:0% +so it's convention +so as we mentioned before actually if + + align:start position:0% +so as we mentioned before actually if + + + align:start position:0% +so as we mentioned before actually if +you look at all these different uh adult + + align:start position:0% +you look at all these different uh adult + + + align:start position:0% +you look at all these different uh adult +products between Indonesia and fellow + + align:start position:0% +products between Indonesia and fellow + + + align:start position:0% +products between Indonesia and fellow +momentum + + align:start position:0% +momentum + + + align:start position:0% +momentum +actually for + + align:start position:0% +actually for + + + align:start position:0% +actually for +because of the moment because of the + + align:start position:0% +because of the moment because of the + + + align:start position:0% +because of the moment because of the +momentum connivation + + align:start position:0% +momentum connivation + + + align:start position:0% +momentum connivation +and the + + align:start position:0% +and the + + + align:start position:0% +and the +actually there are only two + + align:start position:0% +actually there are only two + + + align:start position:0% +actually there are only two +the renting warrant okay + + align:start position:0% +the renting warrant okay + + + align:start position:0% +the renting warrant okay +so so would be convenient + + align:start position:0% +so so would be convenient + + + align:start position:0% +so so would be convenient +to to write this all this in terms of + + align:start position:0% +to to write this all this in terms of + + + align:start position:0% +to to write this all this in terms of +those two uh a Lawrence environment okay + + align:start position:0% +those two uh a Lawrence environment okay + + + align:start position:0% +those two uh a Lawrence environment okay +so so that's the S2 2 of the Stu + + align:start position:0% +so so that's the S2 2 of the Stu + + + align:start position:0% +so so that's the S2 2 of the Stu +variables we defined previously okay so + + align:start position:0% +variables we defined previously okay so + + + align:start position:0% +variables we defined previously okay so +it's often just to use Stu at the same + + align:start position:0% +it's often just to use Stu at the same + + + align:start position:0% +it's often just to use Stu at the same +time so so so we just yeah okay so so + + align:start position:0% +time so so so we just yeah okay so so + + + align:start position:0% +time so so so we just yeah okay so so +now if you write them in terms of Base + + align:start position:0% +now if you write them in terms of Base + + + align:start position:0% +now if you write them in terms of Base +to you + + align:start position:0% +to you + + + align:start position:0% +to you +and then you find for example yeah let + + align:start position:0% +and then you find for example yeah let + + + align:start position:0% +and then you find for example yeah let +me just give you some example for + + align:start position:0% +me just give you some example for + + + align:start position:0% +me just give you some example for +example 2K1 + + align:start position:0% +example 2K1 + + + align:start position:0% +example 2K1 +P1 + + align:start position:0% + + + + align:start position:0% + +so this can be written as t + + align:start position:0% +so this can be written as t + + + align:start position:0% +so this can be written as t +minus M Square minus n Prime squared + + align:start position:0% +minus M Square minus n Prime squared + + + align:start position:0% +minus M Square minus n Prime squared +okay + + align:start position:0% +okay + + + align:start position:0% +okay +which is the same + + align:start position:0% +which is the same + + + align:start position:0% +which is the same +as 2k2 dot P2 + + align:start position:0% +as 2k2 dot P2 + + + align:start position:0% +as 2k2 dot P2 +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and uh 2K1 + + align:start position:0% +and uh 2K1 + + + align:start position:0% +and uh 2K1 +dot P2 then it's actually equal to two + + align:start position:0% +dot P2 then it's actually equal to two + + + align:start position:0% +dot P2 then it's actually equal to two +K2 dot P1 + + align:start position:0% +K2 dot P1 + + + align:start position:0% +K2 dot P1 +then you go to U minus M Square minus M + + align:start position:0% +then you go to U minus M Square minus M + + + align:start position:0% +then you go to U minus M Square minus M +Prime squared + + align:start position:0% +Prime squared + + + align:start position:0% +Prime squared +and then since related to the initial + + align:start position:0% +and then since related to the initial + + + align:start position:0% +and then since related to the initial +momentum then related to the S equal to + + align:start position:0% +momentum then related to the S equal to + + + align:start position:0% +momentum then related to the S equal to +S minus two M Square + + align:start position:0% +S minus two M Square + + + align:start position:0% +S minus two M Square +the minus K1 K2 + + align:start position:0% +the minus K1 K2 + + + align:start position:0% +the minus K1 K2 +okay + + align:start position:0% + + + + align:start position:0% + +so so you just apply those equations in + + align:start position:0% +so so you just apply those equations in + + + align:start position:0% +so so you just apply those equations in +here then you can write them in terms of + + align:start position:0% +here then you can write them in terms of + + + align:start position:0% +here then you can write them in terms of +Stu variables and then you find + + align:start position:0% +Stu variables and then you find + + + align:start position:0% +Stu variables and then you find +with one over sum over spin + + align:start position:0% +with one over sum over spin + + + align:start position:0% +with one over sum over spin +M square is equal to the following + + align:start position:0% +M square is equal to the following + + + align:start position:0% +M square is equal to the following +expression + + align:start position:0% +expression + + + align:start position:0% +expression +2 e to the power 4 + + align:start position:0% +2 e to the power 4 + + + align:start position:0% +2 e to the power 4 +Square + + align:start position:0% + + + + align:start position:0% + +T minus + + align:start position:0% +T minus + + + align:start position:0% +T minus +M Square + + align:start position:0% +M Square + + + align:start position:0% +M Square +Prime squared squared + + align:start position:0% + + + + align:start position:0% + +plus u minus M Square minus n Prime + + align:start position:0% +plus u minus M Square minus n Prime + + + align:start position:0% +plus u minus M Square minus n Prime +Square + + align:start position:0% +Square + + + align:start position:0% +Square +of 2s + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so recall that + + align:start position:0% +so recall that + + + align:start position:0% +so recall that +S Plus t plus u equal to 2 + + align:start position:0% + + + + align:start position:0% + +so you can eliminate one of them okay + + align:start position:0% + + + + align:start position:0% + +so this concludes the calculation + + align:start position:0% + + + + align:start position:0% + +of the scattering amplitude + + align:start position:0% +of the scattering amplitude + + + align:start position:0% +of the scattering amplitude +okay so that's the expression you get + + align:start position:0% +okay so that's the expression you get + + + align:start position:0% +okay so that's the expression you get +okay and you see that it's all expressed + + align:start position:0% +okay and you see that it's all expressed + + + align:start position:0% +okay and you see that it's all expressed +in terms of this s2u okay + + align:start position:0% +in terms of this s2u okay + + + align:start position:0% +in terms of this s2u okay +can be expressed nicely in terms of + + align:start position:0% +can be expressed nicely in terms of + + + align:start position:0% +can be expressed nicely in terms of +these Stu variables + + align:start position:0% +these Stu variables + + + align:start position:0% +these Stu variables +any questions on this + + align:start position:0% + + + + align:start position:0% + +good + + align:start position:0% +good + + + align:start position:0% +good +so now let's calculate the cross action + + align:start position:0% +so now let's calculate the cross action + + + align:start position:0% +so now let's calculate the cross action +and our goal we to calculate the total + + align:start position:0% +and our goal we to calculate the total + + + align:start position:0% +and our goal we to calculate the total +cross section okay + + align:start position:0% +cross section okay + + + align:start position:0% +cross section okay +and so for this purpose let's do the + + align:start position:0% +and so for this purpose let's do the + + + align:start position:0% +and so for this purpose let's do the +center of Mass frame okay + + align:start position:0% + + + + align:start position:0% + +so let's go to the consider the center + + align:start position:0% +so let's go to the consider the center + + + align:start position:0% +so let's go to the consider the center +of Mass frame + + align:start position:0% + + + + align:start position:0% + +so this is the simplest + + align:start position:0% + + + + align:start position:0% + +so remember in the center of Mass frame + + align:start position:0% +so remember in the center of Mass frame + + + align:start position:0% +so remember in the center of Mass frame +we um + + align:start position:0% +we um + + + align:start position:0% +we um +so so so first we need to um + + align:start position:0% +so so so first we need to um + + + align:start position:0% +so so so first we need to um +yeah so remember the certain mesh frame + + align:start position:0% +yeah so remember the certain mesh frame + + + align:start position:0% +yeah so remember the certain mesh frame +you get + + align:start position:0% +you get + + + align:start position:0% +you get +that the um + + align:start position:0% + + + + align:start position:0% + +the um + + align:start position:0% +the um + + + align:start position:0% +the um +the sigma + + align:start position:0% +the sigma + + + align:start position:0% +the sigma +the Omega cm + + align:start position:0% +the Omega cm + + + align:start position:0% +the Omega cm +is given by + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% + + + + align:start position:0% + +yeah let me check my formula suddenly I + + align:start position:0% +yeah let me check my formula suddenly I + + + align:start position:0% +yeah let me check my formula suddenly I +foreign + + align:start position:0% + + + + align:start position:0% + +so it's given by + + align:start position:0% +so it's given by + + + align:start position:0% +so it's given by +say the m + + align:start position:0% +say the m + + + align:start position:0% +say the m +Square + + align:start position:0% +Square + + + align:start position:0% +Square +divided by p c m Prime + + align:start position:0% +divided by p c m Prime + + + align:start position:0% +divided by p c m Prime +divided by + + align:start position:0% +divided by + + + align:start position:0% +divided by +6 4 64 pi squared + + align:start position:0% +6 4 64 pi squared + + + align:start position:0% +6 4 64 pi squared +s + + align:start position:0% +s + + + align:start position:0% +s +p c Prime + + align:start position:0% +p c Prime + + + align:start position:0% +p c Prime +okay so PCM Prime is the momentum in the + + align:start position:0% +okay so PCM Prime is the momentum in the + + + align:start position:0% +okay so PCM Prime is the momentum in the +for the final particles and PCM is the + + align:start position:0% +for the final particles and PCM is the + + + align:start position:0% +for the final particles and PCM is the +momentum in the center of Mass frame for + + align:start position:0% +momentum in the center of Mass frame for + + + align:start position:0% +momentum in the center of Mass frame for +the initial particles okay + + align:start position:0% +the initial particles okay + + + align:start position:0% +the initial particles okay +so so now let's we also need to find the + + align:start position:0% +so so now let's we also need to find the + + + align:start position:0% +so so now let's we also need to find the +PCM Etc okay + + align:start position:0% +PCM Etc okay + + + align:start position:0% +PCM Etc okay +we we also need to express the m + + align:start position:0% +we we also need to express the m + + + align:start position:0% +we we also need to express the m +the amplitude in terms of the Central + + align:start position:0% +the amplitude in terms of the Central + + + align:start position:0% +the amplitude in terms of the Central +Mass script okay + + align:start position:0% +Mass script okay + + + align:start position:0% +Mass script okay +so so in the center of Mass frame + + align:start position:0% +so so in the center of Mass frame + + + align:start position:0% +so so in the center of Mass frame +then we have the P1 + + align:start position:0% +then we have the P1 + + + align:start position:0% +then we have the P1 +would be say e + + align:start position:0% +would be say e + + + align:start position:0% +would be say e +PCM + + align:start position:0% +PCM + + + align:start position:0% +PCM +okay the P2 + + align:start position:0% +okay the P2 + + + align:start position:0% +okay the P2 +will be equal to the same e but the + + align:start position:0% +will be equal to the same e but the + + + align:start position:0% +will be equal to the same e but the +minus PCM + + align:start position:0% +minus PCM + + + align:start position:0% +minus PCM +okay the high but the same e because + + align:start position:0% +okay the high but the same e because + + + align:start position:0% +okay the high but the same e because +they have the same mass + + align:start position:0% +they have the same mass + + + align:start position:0% +they have the same mass +okay the same similarly K1 + + align:start position:0% +okay the same similarly K1 + + + align:start position:0% +okay the same similarly K1 +would be + + align:start position:0% + + + + align:start position:0% + +e + + align:start position:0% +e + + + align:start position:0% +e +Prime + + align:start position:0% + + + + align:start position:0% + +PCMS + + align:start position:0% +PCMS + + + align:start position:0% +PCMS +Prime + + align:start position:0% +Prime + + + align:start position:0% +Prime +and K2 + + align:start position:0% +and K2 + + + align:start position:0% +and K2 +would be e Prime + + align:start position:0% +would be e Prime + + + align:start position:0% +would be e Prime +PCM + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +so now + + align:start position:0% +so now + + + align:start position:0% +so now +from energy conservation immediately + + align:start position:0% +from energy conservation immediately + + + align:start position:0% +from energy conservation immediately +concludes that e must be equal to e + + align:start position:0% +concludes that e must be equal to e + + + align:start position:0% +concludes that e must be equal to e +Prime okay so a second forget about e + + align:start position:0% +Prime okay so a second forget about e + + + align:start position:0% +Prime okay so a second forget about e +Prime okay + + align:start position:0% +Prime okay + + + align:start position:0% +Prime okay +because the total energy would be QE and + + align:start position:0% +because the total energy would be QE and + + + align:start position:0% +because the total energy would be QE and +the final energy will also be 2E so so e + + align:start position:0% +the final energy will also be 2E so so e + + + align:start position:0% +the final energy will also be 2E so so e +have to be equal to e Prime + + align:start position:0% +have to be equal to e Prime + + + align:start position:0% +have to be equal to e Prime +and then we can find + + align:start position:0% +and then we can find + + + align:start position:0% +and then we can find +and so e + + align:start position:0% +and so e + + + align:start position:0% +and so e +would be equal to one half square root S + + align:start position:0% +would be equal to one half square root S + + + align:start position:0% +would be equal to one half square root S +okay + + align:start position:0% + + + + align:start position:0% + +so so this is the um + + align:start position:0% + + + + align:start position:0% + +or s + + align:start position:0% +or s + + + align:start position:0% +or s +is equal to 4G squared + + align:start position:0% + + + + align:start position:0% + +because of the P1 plus P2 is just 2E + + align:start position:0% +because of the P1 plus P2 is just 2E + + + align:start position:0% +because of the P1 plus P2 is just 2E +okay you square it become 4G squared + + align:start position:0% +okay you square it become 4G squared + + + align:start position:0% +okay you square it become 4G squared +and then we find that the PCM + + align:start position:0% + + + + align:start position:0% + +Square + + align:start position:0% +Square + + + align:start position:0% +Square +equal to + + align:start position:0% +equal to + + + align:start position:0% +equal to +then s divided by 4 minus M squared + + align:start position:0% +then s divided by 4 minus M squared + + + align:start position:0% +then s divided by 4 minus M squared +and the PCM + + align:start position:0% +and the PCM + + + align:start position:0% +and the PCM +param Square + + align:start position:0% +param Square + + + align:start position:0% +param Square +equal to S equal to 4 + + align:start position:0% +equal to S equal to 4 + + + align:start position:0% +equal to S equal to 4 +s divided by 4 + + align:start position:0% +s divided by 4 + + + align:start position:0% +s divided by 4 +minus S Prime squared okay + + align:start position:0% + + + + align:start position:0% + +any questions on this + + align:start position:0% + + + + align:start position:0% + +yes + + align:start position:0% + + + + align:start position:0% + +yeah because they have the same mass I + + align:start position:0% +yeah because they have the same mass I + + + align:start position:0% +yeah because they have the same mass I +had to go there momentum over there to + + align:start position:0% +had to go there momentum over there to + + + align:start position:0% +had to go there momentum over there to +each other + + align:start position:0% +each other + + + align:start position:0% +each other +in the center of Mass frame and they + + align:start position:0% +in the center of Mass frame and they + + + align:start position:0% +in the center of Mass frame and they +have the same mass + + align:start position:0% +have the same mass + + + align:start position:0% +have the same mass +[Music] + + align:start position:0% + + + + align:start position:0% + +particle + + align:start position:0% + + + + align:start position:0% + +it's a violation process you always + + align:start position:0% +it's a violation process you always + + + align:start position:0% +it's a violation process you always +create the particle animals + + align:start position:0% + + + + align:start position:0% + +other questions + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so so you can similarly Express the T + + align:start position:0% +so so you can similarly Express the T + + + align:start position:0% +so so you can similarly Express the T +okay you can similarly Express the T and + + align:start position:0% +okay you can similarly Express the T and + + + align:start position:0% +okay you can similarly Express the T and +U in terms of the this uh send a center + + align:start position:0% +U in terms of the this uh send a center + + + align:start position:0% +U in terms of the this uh send a center +of mass the momentum Etc okay and uh so + + align:start position:0% +of mass the momentum Etc okay and uh so + + + align:start position:0% +of mass the momentum Etc okay and uh so +I will uh you can just do that okay so + + align:start position:0% +I will uh you can just do that okay so + + + align:start position:0% +I will uh you can just do that okay so +let me just uh uh write down the final + + align:start position:0% +let me just uh uh write down the final + + + align:start position:0% +let me just uh uh write down the final +answer + + align:start position:0% +answer + + + align:start position:0% +answer +let me just write down the value on so + + align:start position:0% +let me just write down the value on so + + + align:start position:0% +let me just write down the value on so +you can also rewrite one quarter + + align:start position:0% +you can also rewrite one quarter + + + align:start position:0% +you can also rewrite one quarter +some spin + + align:start position:0% +some spin + + + align:start position:0% +some spin +M Square equal to + + align:start position:0% +M Square equal to + + + align:start position:0% +M Square equal to +in terms of the center of mass and then + + align:start position:0% +in terms of the center of mass and then + + + align:start position:0% +in terms of the center of mass and then +you can write the + + align:start position:0% +you can write the + + + align:start position:0% +you can write the +um and then you find is equal to e to + + align:start position:0% +um and then you find is equal to e to + + + align:start position:0% +um and then you find is equal to e to +the power 4 + + align:start position:0% +the power 4 + + + align:start position:0% +the power 4 +1 plus + + align:start position:0% +1 plus + + + align:start position:0% +1 plus +M squared + + align:start position:0% + + + + align:start position:0% + +e Square + + align:start position:0% + + + + align:start position:0% + +okay and the under the uh the Theta is + + align:start position:0% +okay and the under the uh the Theta is + + + align:start position:0% +okay and the under the uh the Theta is +the + + align:start position:0% +the + + + align:start position:0% +the +so you have the scattering of the + + align:start position:0% +so you have the scattering of the + + + align:start position:0% +so you have the scattering of the +initial particle with PCM + + align:start position:0% +initial particle with PCM + + + align:start position:0% +initial particle with PCM +and then you have the final particle + + align:start position:0% +and then you have the final particle + + + align:start position:0% +and then you have the final particle +with the PCM Prime + + align:start position:0% +with the PCM Prime + + + align:start position:0% +with the PCM Prime +and so this angle is set okay + + align:start position:0% +and so this angle is set okay + + + align:start position:0% +and so this angle is set okay +this angle is it + + align:start position:0% + + + + align:start position:0% + +and so the Theta comes from when you + + align:start position:0% +and so the Theta comes from when you + + + align:start position:0% +and so the Theta comes from when you +calculate using the uh using the + + align:start position:0% +calculate using the uh using the + + + align:start position:0% +calculate using the uh using the +involving key and U okay + + align:start position:0% +involving key and U okay + + + align:start position:0% +involving key and U okay +moving here + + align:start position:0% +moving here + + + align:start position:0% +moving here +and so now you have now we have + + align:start position:0% +and so now you have now we have + + + align:start position:0% +and so now you have now we have +everything + + align:start position:0% +everything + + + align:start position:0% +everything +so we have the PCM + + align:start position:0% + + + + align:start position:0% + +it's all in terms of s + + align:start position:0% +it's all in terms of s + + + align:start position:0% +it's all in terms of s +and then your your amplitude is also + + align:start position:0% +and then your your amplitude is also + + + align:start position:0% +and then your your amplitude is also +expressed in terms of the uh either s or + + align:start position:0% +expressed in terms of the uh either s or + + + align:start position:0% +expressed in terms of the uh either s or +E Yeah e is also the S and then we have + + align:start position:0% +E Yeah e is also the S and then we have + + + align:start position:0% +E Yeah e is also the S and then we have +the Theta okay + + align:start position:0% +the Theta okay + + + align:start position:0% +the Theta okay +then we have the Theta + + align:start position:0% +then we have the Theta + + + align:start position:0% +then we have the Theta +so so this is so you just plug the whole + + align:start position:0% +so so this is so you just plug the whole + + + align:start position:0% +so so this is so you just plug the whole +thing into here + + align:start position:0% +thing into here + + + align:start position:0% +thing into here +okay just plug the whole thing into here + + align:start position:0% +okay just plug the whole thing into here + + + align:start position:0% +okay just plug the whole thing into here +and then you find the total + + align:start position:0% +and then you find the total + + + align:start position:0% +and then you find the total +cross-section + + align:start position:0% + + + + align:start position:0% + +okay it's just the + + align:start position:0% +okay it's just the + + + align:start position:0% +okay it's just the +the sigma + + align:start position:0% +the sigma + + + align:start position:0% +the sigma +the Omega + + align:start position:0% +the Omega + + + align:start position:0% +the Omega +it's in the Mass frame + + align:start position:0% +it's in the Mass frame + + + align:start position:0% +it's in the Mass frame +and then sine Theta + + align:start position:0% + + + + align:start position:0% + +5 okay nothing here depends on Phi so + + align:start position:0% +5 okay nothing here depends on Phi so + + + align:start position:0% +5 okay nothing here depends on Phi so +the Phi integral you can just down + + align:start position:0% +the Phi integral you can just down + + + align:start position:0% +the Phi integral you can just down +attributory and then you just need to do + + align:start position:0% +attributory and then you just need to do + + + align:start position:0% +attributory and then you just need to do +the Theta integral and then you have + + align:start position:0% +the Theta integral and then you have + + + align:start position:0% +the Theta integral and then you have +this okay + + align:start position:0% + + + + align:start position:0% + +so so again uh let me just write down + + align:start position:0% +so so again uh let me just write down + + + align:start position:0% +so so again uh let me just write down +the final answer + + align:start position:0% + + + + align:start position:0% + +so in the end you get + + align:start position:0% +so in the end you get + + + align:start position:0% +so in the end you get +4 pi + + align:start position:0% +4 pi + + + align:start position:0% +4 pi +Alpha Square + + align:start position:0% +Alpha Square + + + align:start position:0% +Alpha Square +divided by S + + align:start position:0% +divided by S + + + align:start position:0% +divided by S +so the alpha is to find structure + + align:start position:0% +so the alpha is to find structure + + + align:start position:0% +so the alpha is to find structure +constant + + align:start position:0% + + + + align:start position:0% + +um yeah so the alpha + + align:start position:0% +um yeah so the alpha + + + align:start position:0% +um yeah so the alpha +here's e squared divided by 4 pi + + align:start position:0% +here's e squared divided by 4 pi + + + align:start position:0% +here's e squared divided by 4 pi +is defined structure constant + + align:start position:0% +is defined structure constant + + + align:start position:0% +is defined structure constant +and + + align:start position:0% +and + + + align:start position:0% +and +um + + align:start position:0% +um + + + align:start position:0% +um +this is four Pi Alpha squares 3s + + align:start position:0% +this is four Pi Alpha squares 3s + + + align:start position:0% +this is four Pi Alpha squares 3s +and then + + align:start position:0% +and then + + + align:start position:0% +and then +y minus + + align:start position:0% +y minus + + + align:start position:0% +y minus +Prime squared divided by E Square + + align:start position:0% + + + + align:start position:0% + +minus + + align:start position:0% +minus + + + align:start position:0% +minus +M squared divided by E squared + + align:start position:0% + + + + align:start position:0% + +and the hosting times + + align:start position:0% +and the hosting times + + + align:start position:0% +and the hosting times +1 plus + + align:start position:0% +1 plus + + + align:start position:0% +1 plus +M Square divided by 2E squared + + align:start position:0% + + + + align:start position:0% + +and one plus and Prime squared divided + + align:start position:0% +and one plus and Prime squared divided + + + align:start position:0% +and one plus and Prime squared divided +by 2E squared + + align:start position:0% +by 2E squared + + + align:start position:0% +by 2E squared +okay + + align:start position:0% + + + + align:start position:0% + +so this is a final answer okay + + align:start position:0% +so this is a final answer okay + + + align:start position:0% +so this is a final answer okay +and this is also you can compare with + + align:start position:0% +and this is also you can compare with + + + align:start position:0% +and this is also you can compare with +experiments + + align:start position:0% +experiments + + + align:start position:0% +experiments +okay so this is also you can compare + + align:start position:0% +okay so this is also you can compare + + + align:start position:0% +okay so this is also you can compare +experience + + align:start position:0% + + + + align:start position:0% + +any questions + + align:start position:0% + + + + align:start position:0% + +so now if you look at this answer + + align:start position:0% + + + + align:start position:0% + +it's almost completely symmetric in + + align:start position:0% +it's almost completely symmetric in + + + align:start position:0% +it's almost completely symmetric in +terms of n and n Prime + + align:start position:0% +terms of n and n Prime + + + align:start position:0% +terms of n and n Prime +okay except that for this ratio and the + + align:start position:0% +okay except that for this ratio and the + + + align:start position:0% +okay except that for this ratio and the +m is downstairs and M Prime is upstairs + + align:start position:0% +m is downstairs and M Prime is upstairs + + + align:start position:0% +m is downstairs and M Prime is upstairs +okay otherwise it's the uh yeah + + align:start position:0% + + + + align:start position:0% + +so so this m Prime is upstairs of course + + align:start position:0% +so so this m Prime is upstairs of course + + + align:start position:0% +so so this m Prime is upstairs of course +it's the um + + align:start position:0% + + + + align:start position:0% + +yeah yeah + + align:start position:0% + + + + align:start position:0% + +great yeah so so this factor is key + + align:start position:0% + + + + align:start position:0% + +okay you have to have such kind of + + align:start position:0% +okay you have to have such kind of + + + align:start position:0% +okay you have to have such kind of +factor in the upstairs + + align:start position:0% +factor in the upstairs + + + align:start position:0% +factor in the upstairs +because when e you have to be e to be + + align:start position:0% +because when e you have to be e to be + + + align:start position:0% +because when e you have to be e to be +greater than M Prime Square in order to + + align:start position:0% +greater than M Prime Square in order to + + + align:start position:0% +greater than M Prime Square in order to +produce the particle + + align:start position:0% +produce the particle + + + align:start position:0% +produce the particle +okay if the if your energy is not big + + align:start position:0% +okay if the if your energy is not big + + + align:start position:0% +okay if the if your energy is not big +enough to produce uh uh in order to + + align:start position:0% +enough to produce uh uh in order to + + + align:start position:0% +enough to produce uh uh in order to +produce B and B Bar your energy at least + + align:start position:0% +produce B and B Bar your energy at least + + + align:start position:0% +produce B and B Bar your energy at least +so each so the uh so the so the uh each + + align:start position:0% +so each so the uh so the so the uh each + + + align:start position:0% +so each so the uh so the so the uh each +e has to be large enough to be the + + align:start position:0% +e has to be large enough to be the + + + align:start position:0% +e has to be large enough to be the +greater than uh than M okay because the + + align:start position:0% +greater than uh than M okay because the + + + align:start position:0% +greater than uh than M okay because the +uh your QE total energy must be greater + + align:start position:0% +uh your QE total energy must be greater + + + align:start position:0% +uh your QE total energy must be greater +than 2 m Prime + + align:start position:0% +than 2 m Prime + + + align:start position:0% +than 2 m Prime +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and so you see that when uh uh uh when e + + align:start position:0% +and so you see that when uh uh uh when e + + + align:start position:0% +and so you see that when uh uh uh when e +is smaller than uh M Prime and when e + + align:start position:0% +is smaller than uh M Prime and when e + + + align:start position:0% +is smaller than uh M Prime and when e +equal to n Prime and then this Factor + + align:start position:0% +equal to n Prime and then this Factor + + + align:start position:0% +equal to n Prime and then this Factor +becomes zero and then the cross-section + + align:start position:0% +becomes zero and then the cross-section + + + align:start position:0% +becomes zero and then the cross-section +becomes zero okay + + align:start position:0% + + + + align:start position:0% + +any questions on this + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so now let's consider some specific + + align:start position:0% +so now let's consider some specific + + + align:start position:0% +so now let's consider some specific +cases + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +now let's consider + + align:start position:0% + + + + align:start position:0% + +e plus e minus going to muon + + align:start position:0% + + + + align:start position:0% + +is a + + align:start position:0% +is a + + + align:start position:0% +is a +the next + + align:start position:0% +the next + + + align:start position:0% +the next +massive laptop after the electron + + align:start position:0% +massive laptop after the electron + + + align:start position:0% +massive laptop after the electron +okay so in this case + + align:start position:0% +okay so in this case + + + align:start position:0% +okay so in this case +say m e + + align:start position:0% +say m e + + + align:start position:0% +say m e +M Square will be m e squared + + align:start position:0% +M Square will be m e squared + + + align:start position:0% +M Square will be m e squared +and the m m Prime Square will be mu + + align:start position:0% +and the m m Prime Square will be mu + + + align:start position:0% +and the m m Prime Square will be mu +squared + + align:start position:0% +squared + + + align:start position:0% +squared +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and mu + + align:start position:0% + + + + align:start position:0% + +so the MU or mass is 207 Mev + + align:start position:0% + + + + align:start position:0% + +oh no + + align:start position:0% + + + + align:start position:0% + +100s + + align:start position:0% +100s + + + align:start position:0% +100s +um + + align:start position:0% +um + + + align:start position:0% +um +actually I didn't code number so so mu + + align:start position:0% +actually I didn't code number so so mu + + + align:start position:0% +actually I didn't code number so so mu +and mass is 207 + + align:start position:0% +and mass is 207 + + + align:start position:0% +and mass is 207 +times and the mass of the electron + + align:start position:0% +times and the mass of the electron + + + align:start position:0% +times and the mass of the electron +okay so do you do anybody remember the + + align:start position:0% +okay so do you do anybody remember the + + + align:start position:0% +okay so do you do anybody remember the +electron Mass + + align:start position:0% + + + + align:start position:0% + +hmm + + align:start position:0% +hmm + + + align:start position:0% +hmm +yeah that's right yeah yeah 0.5 + + align:start position:0% +yeah that's right yeah yeah 0.5 + + + align:start position:0% +yeah that's right yeah yeah 0.5 +1 did you say one + + align:start position:0% +1 did you say one + + + align:start position:0% +1 did you say one +yeah yeah it's 511 Kev yeah + + align:start position:0% +yeah yeah it's 511 Kev yeah + + + align:start position:0% +yeah yeah it's 511 Kev yeah +uh 0.511 or Meb and the muon is the 207 + + align:start position:0% +uh 0.511 or Meb and the muon is the 207 + + + align:start position:0% +uh 0.511 or Meb and the muon is the 207 +times the mass of the electron + + align:start position:0% +times the mass of the electron + + + align:start position:0% +times the mass of the electron +so when you so if you want to create the + + align:start position:0% +so when you so if you want to create the + + + align:start position:0% +so when you so if you want to create the +MU arm + + align:start position:0% +MU arm + + + align:start position:0% +MU arm +then the initial total energy okay so + + align:start position:0% +then the initial total energy okay so + + + align:start position:0% +then the initial total energy okay so +that so the so the s + + align:start position:0% +that so the so the s + + + align:start position:0% +that so the so the s +so the square root S which is 2E + + align:start position:0% +so the square root S which is 2E + + + align:start position:0% +so the square root S which is 2E +have to be greater than the 2 and mu + + align:start position:0% +have to be greater than the 2 and mu + + + align:start position:0% +have to be greater than the 2 and mu +okay so that means that the E has to be + + align:start position:0% +okay so that means that the E has to be + + + align:start position:0% +okay so that means that the E has to be +greater than mu + + align:start position:0% + + + + align:start position:0% + +and then this is much much larger than + + align:start position:0% +and then this is much much larger than + + + align:start position:0% +and then this is much much larger than +electron Mass + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +so this is about 200 times larger than + + align:start position:0% +so this is about 200 times larger than + + + align:start position:0% +so this is about 200 times larger than +me + + align:start position:0% +me + + + align:start position:0% +me +so that means actually that the + + align:start position:0% +so that means actually that the + + + align:start position:0% +so that means actually that the +for All Purpose that you can just relax + + align:start position:0% +for All Purpose that you can just relax + + + align:start position:0% +for All Purpose that you can just relax +the electron Mass + + align:start position:0% +the electron Mass + + + align:start position:0% +the electron Mass +okay and so uh so this ratio is a huge + + align:start position:0% +okay and so uh so this ratio is a huge + + + align:start position:0% +okay and so uh so this ratio is a huge +uh so this ratio is 10. + + align:start position:0% +uh so this ratio is 10. + + + align:start position:0% +uh so this ratio is 10. +okay uh + + align:start position:0% +okay uh + + + align:start position:0% +okay uh +it's tiny so we can treat the + + align:start position:0% +it's tiny so we can treat the + + + align:start position:0% +it's tiny so we can treat the +essentially electron as messages + + align:start position:0% + + + + align:start position:0% + +yeah I just not well defined yeah + + align:start position:0% + + + + align:start position:0% + +system + + align:start position:0% +system + + + align:start position:0% +system +no you you don't even yeah in this case + + align:start position:0% +no you you don't even yeah in this case + + + align:start position:0% +no you you don't even yeah in this case +you don't even go to that so so + + align:start position:0% +you don't even go to that so so + + + align:start position:0% +you don't even go to that so so +um + + align:start position:0% +um + + + align:start position:0% +um +so in the case that the um + + align:start position:0% +so in the case that the um + + + align:start position:0% +so in the case that the um +uh yeah uh let me see so so in the case + + align:start position:0% +uh yeah uh let me see so so in the case + + + align:start position:0% +uh yeah uh let me see so so in the case +that the um + + align:start position:0% + + + + align:start position:0% + +uh let me think a little bit + + align:start position:0% +uh let me think a little bit + + + align:start position:0% +uh let me think a little bit +um yeah + + align:start position:0% +um yeah + + + align:start position:0% +um yeah +um + + align:start position:0% +um + + + align:start position:0% +um +right + + align:start position:0% +right + + + align:start position:0% +right +so yeah for this case of course it's not + + align:start position:0% +so yeah for this case of course it's not + + + align:start position:0% +so yeah for this case of course it's not +very defined but in the office case + + align:start position:0% +very defined but in the office case + + + align:start position:0% +very defined but in the office case +let's imagine if you have the two very + + align:start position:0% +let's imagine if you have the two very + + + align:start position:0% +let's imagine if you have the two very +massive particles to collide to create + + align:start position:0% +massive particles to collide to create + + + align:start position:0% +massive particles to collide to create +say lighter particle and then in that + + align:start position:0% +say lighter particle and then in that + + + align:start position:0% +say lighter particle and then in that +case + + align:start position:0% +case + + + align:start position:0% +case +um yeah actually I don't remember the + + align:start position:0% +um yeah actually I don't remember the + + + align:start position:0% +um yeah actually I don't remember the +answer from my top of my head yeah it's + + align:start position:0% +answer from my top of my head yeah it's + + + align:start position:0% +answer from my top of my head yeah it's +a good question I will uh try to find it + + align:start position:0% +a good question I will uh try to find it + + + align:start position:0% +a good question I will uh try to find it +afterwards + + align:start position:0% +afterwards + + + align:start position:0% +afterwards +any other questions + + align:start position:0% +any other questions + + + align:start position:0% +any other questions +okay good + + align:start position:0% +okay good + + + align:start position:0% +okay good +so + + align:start position:0% +so + + + align:start position:0% +so +so in this case + + align:start position:0% +so in this case + + + align:start position:0% +so in this case +so when the when the electron mass is + + align:start position:0% +so when the when the electron mass is + + + align:start position:0% +so when the when the electron mass is +much larger than when the uh the mirror + + align:start position:0% +much larger than when the uh the mirror + + + align:start position:0% +much larger than when the uh the mirror +message might not do the electron Mass + + align:start position:0% +message might not do the electron Mass + + + align:start position:0% +message might not do the electron Mass +and then the um + + align:start position:0% +and then the um + + + align:start position:0% +and then the um +then the beacon set + + align:start position:0% +then the beacon set + + + align:start position:0% +then the beacon set +essentially me equal to zero + + align:start position:0% +essentially me equal to zero + + + align:start position:0% +essentially me equal to zero +okay and in this case the formula + + align:start position:0% +okay and in this case the formula + + + align:start position:0% +okay and in this case the formula +becomes simpler + + align:start position:0% + + + + align:start position:0% + +and then in this case it becomes similar + + align:start position:0% +and then in this case it becomes similar + + + align:start position:0% +and then in this case it becomes similar +the downstairs equal just equal to one + + align:start position:0% +the downstairs equal just equal to one + + + align:start position:0% +the downstairs equal just equal to one +and uh and this Factor also become what + + align:start position:0% +and uh and this Factor also become what + + + align:start position:0% +and uh and this Factor also become what +okay + + align:start position:0% +okay + + + align:start position:0% +okay +this Factor also become one + + align:start position:0% +this Factor also become one + + + align:start position:0% +this Factor also become one +so then there are two interesting + + align:start position:0% +so then there are two interesting + + + align:start position:0% +so then there are two interesting +regimes + + align:start position:0% + + + + align:start position:0% + +there are two interesting regimes + + align:start position:0% +there are two interesting regimes + + + align:start position:0% +there are two interesting regimes +so the first is you just need the + + align:start position:0% +so the first is you just need the + + + align:start position:0% +so the first is you just need the +threshold + + align:start position:0% + + + + align:start position:0% + +okay just near the threshold means that + + align:start position:0% +okay just near the threshold means that + + + align:start position:0% +okay just near the threshold means that +the PCM + + align:start position:0% + + + + align:start position:0% + +Prime is much much smaller than mu + + align:start position:0% +Prime is much much smaller than mu + + + align:start position:0% +Prime is much much smaller than mu +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so in this regime then the E would be + + align:start position:0% +so in this regime then the E would be + + + align:start position:0% +so in this regime then the E would be +approximately just a mu + + align:start position:0% +approximately just a mu + + + align:start position:0% +approximately just a mu +okay and then s will be approximately + + align:start position:0% +okay and then s will be approximately + + + align:start position:0% +okay and then s will be approximately +just for a mu squared + + align:start position:0% + + + + align:start position:0% + +so so now if you just look at that + + align:start position:0% +so so now if you just look at that + + + align:start position:0% +so so now if you just look at that +expression + + align:start position:0% +expression + + + align:start position:0% +expression +um + + align:start position:0% +um + + + align:start position:0% +um +yeah so so let's look at that expression + + align:start position:0% +yeah so so let's look at that expression + + + align:start position:0% +yeah so so let's look at that expression +then you find + + align:start position:0% +then you find + + + align:start position:0% +then you find +the + + align:start position:0% +the + + + align:start position:0% +the +um + + align:start position:0% +um + + + align:start position:0% +um +the + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +then you find that the total the + + align:start position:0% +then you find that the total the + + + align:start position:0% +then you find that the total the +differential cross action + + align:start position:0% +differential cross action + + + align:start position:0% +differential cross action +is equal to Alpha Square + + align:start position:0% +is equal to Alpha Square + + + align:start position:0% +is equal to Alpha Square +to eight + + align:start position:0% +to eight + + + align:start position:0% +to eight +mu squared + + align:start position:0% +mu squared + + + align:start position:0% +mu squared +and then + + align:start position:0% +and then + + + align:start position:0% +and then +PCM Prime + + align:start position:0% +PCM Prime + + + align:start position:0% +PCM Prime +divided by Nu + + align:start position:0% +divided by Nu + + + align:start position:0% +divided by Nu +plus higher all the corrections okay so + + align:start position:0% +plus higher all the corrections okay so + + + align:start position:0% +plus higher all the corrections okay so +you expand in in PCM divided by mu okay + + align:start position:0% +you expand in in PCM divided by mu okay + + + align:start position:0% +you expand in in PCM divided by mu okay +PCM Prime divided by m u and the total + + align:start position:0% +PCM Prime divided by m u and the total + + + align:start position:0% +PCM Prime divided by m u and the total +cross-section + + align:start position:0% + + + + align:start position:0% + +just give them by pi Alpha Square + + align:start position:0% +just give them by pi Alpha Square + + + align:start position:0% +just give them by pi Alpha Square +2 mu squared + + align:start position:0% +2 mu squared + + + align:start position:0% +2 mu squared +and PCM + + align:start position:0% +and PCM + + + align:start position:0% +and PCM +Prime right there + + align:start position:0% +Prime right there + + + align:start position:0% +Prime right there +okay so so you hear you see explicitly + + align:start position:0% +okay so so you hear you see explicitly + + + align:start position:0% +okay so so you hear you see explicitly +that when you reach the threshold + + align:start position:0% +that when you reach the threshold + + + align:start position:0% +that when you reach the threshold +the reach the threshold because when + + align:start position:0% +the reach the threshold because when + + + align:start position:0% +the reach the threshold because when +this quantity goes to zero + + align:start position:0% +this quantity goes to zero + + + align:start position:0% +this quantity goes to zero +okay so when this quantity goes to zero + + align:start position:0% +okay so when this quantity goes to zero + + + align:start position:0% +okay so when this quantity goes to zero +and then you uh uh yeah + + align:start position:0% +and then you uh uh yeah + + + align:start position:0% +and then you uh uh yeah +yeah and then you uh um + + align:start position:0% +yeah and then you uh um + + + align:start position:0% +yeah and then you uh um +at the course I can go to do okay + + align:start position:0% +at the course I can go to do okay + + + align:start position:0% +at the course I can go to do okay +so another regime of Interest + + align:start position:0% + + + + align:start position:0% + +is the actual relativistic regime + + align:start position:0% + + + + align:start position:0% + +the actual optimistic regime so in this + + align:start position:0% +the actual optimistic regime so in this + + + align:start position:0% +the actual optimistic regime so in this +in this case which we can take e to be + + align:start position:0% +in this case which we can take e to be + + + align:start position:0% +in this case which we can take e to be +much much both the me and mu + + align:start position:0% +much much both the me and mu + + + align:start position:0% +much much both the me and mu +so also much greater than mu okay so of + + align:start position:0% +so also much greater than mu okay so of + + + align:start position:0% +so also much greater than mu okay so of +course it's already much greater than me + + align:start position:0% +course it's already much greater than me + + + align:start position:0% +course it's already much greater than me +so in this case then then we can uh yeah + + align:start position:0% +so in this case then then we can uh yeah + + + align:start position:0% +so in this case then then we can uh yeah +you can just hear + + align:start position:0% +you can just hear + + + align:start position:0% +you can just hear +uh uh uh uh you can just you simply take + + align:start position:0% +uh uh uh uh you can just you simply take + + + align:start position:0% +uh uh uh uh you can just you simply take +the both Mass to be zero in this case + + align:start position:0% +the both Mass to be zero in this case + + + align:start position:0% +the both Mass to be zero in this case +and then you find in this case + + align:start position:0% +and then you find in this case + + + align:start position:0% +and then you find in this case +that the sigma + + align:start position:0% +that the sigma + + + align:start position:0% +that the sigma +the Omega CM because you can given by + + align:start position:0% +the Omega CM because you can given by + + + align:start position:0% +the Omega CM because you can given by +Alpha Square divided by 4s + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and then you can find the total + + align:start position:0% +and then you can find the total + + + align:start position:0% +and then you can find the total +cross-section + + align:start position:0% +cross-section + + + align:start position:0% +cross-section +[Applause] + + align:start position:0% + + + + align:start position:0% + +so you can find the total cross-section + + align:start position:0% + + + + align:start position:0% + +given by + + align:start position:0% + + + + align:start position:0% + +4 Pi Alpha Square + + align:start position:0% +4 Pi Alpha Square + + + align:start position:0% +4 Pi Alpha Square +divided by 3x okay + + align:start position:0% +divided by 3x okay + + + align:start position:0% +divided by 3x okay +so now this final formula is very simple + + align:start position:0% + + + + align:start position:0% + +so you could + + align:start position:0% +so you could + + + align:start position:0% +so you could +have written down this formula without + + align:start position:0% +have written down this formula without + + + align:start position:0% +have written down this formula without +doing any calculation + + align:start position:0% +doing any calculation + + + align:start position:0% +doing any calculation +of course up to the prefactor + + align:start position:0% +of course up to the prefactor + + + align:start position:0% +of course up to the prefactor +just on dimensional graph okay so in the + + align:start position:0% +just on dimensional graph okay so in the + + + align:start position:0% +just on dimensional graph okay so in the +archerativistic regime + + align:start position:0% +archerativistic regime + + + align:start position:0% +archerativistic regime +then essentially you can neglect both + + align:start position:0% +then essentially you can neglect both + + + align:start position:0% +then essentially you can neglect both +the mass of the initial particle and the + + align:start position:0% +the mass of the initial particle and the + + + align:start position:0% +the mass of the initial particle and the +final product + + align:start position:0% +final product + + + align:start position:0% +final product +and then in this the the in this whole + + align:start position:0% +and then in this the the in this whole + + + align:start position:0% +and then in this the the in this whole +process if the initial particles message + + align:start position:0% +process if the initial particles message + + + align:start position:0% +process if the initial particles message +and the final particle is massless and + + align:start position:0% +and the final particle is massless and + + + align:start position:0% +and the final particle is massless and +then for for this whole process the only + + align:start position:0% +then for for this whole process the only + + + align:start position:0% +then for for this whole process the only +scale is what + + align:start position:0% + + + + align:start position:0% + +the only scale is s okay that's the only + + align:start position:0% +the only scale is s okay that's the only + + + align:start position:0% +the only scale is s okay that's the only +scale so the only scale is s + + align:start position:0% +scale so the only scale is s + + + align:start position:0% +scale so the only scale is s +and essentially and then that means and + + align:start position:0% +and essentially and then that means and + + + align:start position:0% +and essentially and then that means and +this should have Dimension + + align:start position:0% +this should have Dimension + + + align:start position:0% +this should have Dimension +area Okay and then that means that there + + align:start position:0% +area Okay and then that means that there + + + align:start position:0% +area Okay and then that means that there +should be one over s + + align:start position:0% +should be one over s + + + align:start position:0% +should be one over s +okay and then Alpha Square just comes + + align:start position:0% +okay and then Alpha Square just comes + + + align:start position:0% +okay and then Alpha Square just comes +from because we have two vertex okay + + align:start position:0% +from because we have two vertex okay + + + align:start position:0% +from because we have two vertex okay +and a from a tree level or process + + align:start position:0% + + + + align:start position:0% + +good + + align:start position:0% +good + + + align:start position:0% +good +so + + align:start position:0% +so + + + align:start position:0% +so +um + + align:start position:0% + + + + align:start position:0% + +good + + align:start position:0% +good + + + align:start position:0% +good +so if you draw the plot + + align:start position:0% + + + + align:start position:0% + +Say Say often we feature the total + + align:start position:0% +Say Say often we feature the total + + + align:start position:0% +Say Say often we feature the total +cross-section times s + + align:start position:0% + + + + align:start position:0% + +so s times the total cross-section as a + + align:start position:0% +so s times the total cross-section as a + + + align:start position:0% +so s times the total cross-section as a +function of the square root S + + align:start position:0% +function of the square root S + + + align:start position:0% +function of the square root S +then this threshold is at 2 mu 2 mu + + align:start position:0% +then this threshold is at 2 mu 2 mu + + + align:start position:0% +then this threshold is at 2 mu 2 mu +and then + + align:start position:0% + + + + align:start position:0% + +and then uh here it goes zero like a + + align:start position:0% +and then uh here it goes zero like a + + + align:start position:0% +and then uh here it goes zero like a +square root + + align:start position:0% +square root + + + align:start position:0% +square root +and then you are going to say approach + + align:start position:0% +and then you are going to say approach + + + align:start position:0% +and then you are going to say approach +your const approach your constant this + + align:start position:0% +your const approach your constant this + + + align:start position:0% +your const approach your constant this +is 4 pi + + align:start position:0% +is 4 pi + + + align:start position:0% +is 4 pi +of a square + + align:start position:0% + + + + align:start position:0% + +okay so so you have a curve like this + + align:start position:0% +okay so so you have a curve like this + + + align:start position:0% +okay so so you have a curve like this +okay + + align:start position:0% + + + + align:start position:0% + +foreign + + align:start position:0% + + + + align:start position:0% + +so now let's consider + + align:start position:0% +so now let's consider + + + align:start position:0% +so now let's consider +now let's consider using this process + + align:start position:0% +now let's consider using this process + + + align:start position:0% +now let's consider using this process +to show that actually the the quarks + + align:start position:0% +to show that actually the the quarks + + + align:start position:0% +to show that actually the the quarks +have three colors okay + + align:start position:0% +have three colors okay + + + align:start position:0% +have three colors okay +the clock says three colors + + align:start position:0% +the clock says three colors + + + align:start position:0% +the clock says three colors +so for this purpose let's consider + + align:start position:0% + + + + align:start position:0% + +e plus minus E plus e minus + + align:start position:0% +e plus minus E plus e minus + + + align:start position:0% +e plus minus E plus e minus +goes to hydrogens + + align:start position:0% + + + + align:start position:0% + +so so this simile is a very complicated + + align:start position:0% +so so this simile is a very complicated + + + align:start position:0% +so so this simile is a very complicated +process + + align:start position:0% +process + + + align:start position:0% +process +okay similarly this is a very + + align:start position:0% +okay similarly this is a very + + + align:start position:0% +okay similarly this is a very +complicated process + + align:start position:0% +complicated process + + + align:start position:0% +complicated process +it's because the uh + + align:start position:0% +it's because the uh + + + align:start position:0% +it's because the uh +so suppose say suppose if you have e + + align:start position:0% +so suppose say suppose if you have e + + + align:start position:0% +so suppose say suppose if you have e +plus + + align:start position:0% +plus + + + align:start position:0% +plus +you create a clock and the anti-clock + + align:start position:0% +you create a clock and the anti-clock + + + align:start position:0% +you create a clock and the anti-clock +pair + + align:start position:0% +pair + + + align:start position:0% +pair +but remember the clocks + + align:start position:0% +but remember the clocks + + + align:start position:0% +but remember the clocks +they're they're confined + + align:start position:0% +they're they're confined + + + align:start position:0% +they're they're confined +okay so so we don't observe individual + + align:start position:0% +okay so so we don't observe individual + + + align:start position:0% +okay so so we don't observe individual +clocks it's because the qcd is shown + + align:start position:0% +clocks it's because the qcd is shown + + + align:start position:0% +clocks it's because the qcd is shown +interacting and so the clocks are + + align:start position:0% +interacting and so the clocks are + + + align:start position:0% +interacting and so the clocks are +confined inside the proton parents Etc + + align:start position:0% +confined inside the proton parents Etc + + + align:start position:0% +confined inside the proton parents Etc +and so so in this process + + align:start position:0% +and so so in this process + + + align:start position:0% +and so so in this process +so even though originally created the + + align:start position:0% +so even though originally created the + + + align:start position:0% +so even though originally created the +clock + + align:start position:0% +clock + + + align:start position:0% +clock +but each individual clock and anti-clock + + align:start position:0% +but each individual clock and anti-clock + + + align:start position:0% +but each individual clock and anti-clock +they cannot survive either on their own + + align:start position:0% +they cannot survive either on their own + + + align:start position:0% +they cannot survive either on their own +so so they will so their presence will + + align:start position:0% +so so they will so their presence will + + + align:start position:0% +so so they will so their presence will +polarize the vacuum create many other + + align:start position:0% +polarize the vacuum create many other + + + align:start position:0% +polarize the vacuum create many other +particles + + align:start position:0% +particles + + + align:start position:0% +particles +and so so what happens is that you uh + + align:start position:0% +and so so what happens is that you uh + + + align:start position:0% +and so so what happens is that you uh +you create uh so each of them will + + align:start position:0% +you create uh so each of them will + + + align:start position:0% +you create uh so each of them will +create a lot of particles along with + + align:start position:0% +create a lot of particles along with + + + align:start position:0% +create a lot of particles along with +them + + align:start position:0% +them + + + align:start position:0% +them +okay so in the end it's a complicated + + align:start position:0% +okay so in the end it's a complicated + + + align:start position:0% +okay so in the end it's a complicated +product You observe many hydrogens okay + + align:start position:0% +product You observe many hydrogens okay + + + align:start position:0% +product You observe many hydrogens okay +You observe many hydraulics + + align:start position:0% +You observe many hydraulics + + + align:start position:0% +You observe many hydraulics +foreign + + align:start position:0% + + + + align:start position:0% + +how do we in our in any hope to be able + + align:start position:0% +how do we in our in any hope to be able + + + align:start position:0% +how do we in our in any hope to be able +to understand this process just by + + align:start position:0% +to understand this process just by + + + align:start position:0% +to understand this process just by +imagining this very complicated product + + align:start position:0% +imagining this very complicated product + + + align:start position:0% +imagining this very complicated product +because this product can have protons + + align:start position:0% +because this product can have protons + + + align:start position:0% +because this product can have protons +neutrons ions can also have other cells + + align:start position:0% +neutrons ions can also have other cells + + + align:start position:0% +neutrons ions can also have other cells +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and then this is a very complicated + + align:start position:0% +and then this is a very complicated + + + align:start position:0% +and then this is a very complicated +process + + align:start position:0% +process + + + align:start position:0% +process +but now the key is the following + + align:start position:0% +but now the key is the following + + + align:start position:0% +but now the key is the following +but now the key is the following + + align:start position:0% +but now the key is the following + + + align:start position:0% +but now the key is the following +indeed if you look at the question + + align:start position:0% +indeed if you look at the question + + + align:start position:0% +indeed if you look at the question +of going to each individual hydrant is + + align:start position:0% +of going to each individual hydrant is + + + align:start position:0% +of going to each individual hydrant is +complicated + + align:start position:0% +complicated + + + align:start position:0% +complicated +but if you consider in a so-called + + align:start position:0% +but if you consider in a so-called + + + align:start position:0% +but if you consider in a so-called +include inclusive + + align:start position:0% +include inclusive + + + align:start position:0% +include inclusive +process which goes to all possible + + align:start position:0% +process which goes to all possible + + + align:start position:0% +process which goes to all possible +hydrons in this process okay + + align:start position:0% +hydrons in this process okay + + + align:start position:0% +hydrons in this process okay +and then that probability just given by + + align:start position:0% +and then that probability just given by + + + align:start position:0% +and then that probability just given by +the total cross-section + + align:start position:0% +the total cross-section + + + align:start position:0% +the total cross-section +okay remember the total cosine just + + align:start position:0% +okay remember the total cosine just + + + align:start position:0% +okay remember the total cosine just +matches the total probability + + align:start position:0% +matches the total probability + + + align:start position:0% +matches the total probability +to create say to create such particles + + align:start position:0% +to create say to create such particles + + + align:start position:0% +to create say to create such particles +and and then when they are created and + + align:start position:0% +and and then when they are created and + + + align:start position:0% +and and then when they are created and +then they they go through a complicated + + align:start position:0% +then they they go through a complicated + + + align:start position:0% +then they they go through a complicated +process but that process is unitary + + align:start position:0% +process but that process is unitary + + + align:start position:0% +process but that process is unitary +we're not uh will be uh uh uh say or + + align:start position:0% +we're not uh will be uh uh uh say or + + + align:start position:0% +we're not uh will be uh uh uh say or +probability why to go to all possible + + align:start position:0% +probability why to go to all possible + + + align:start position:0% +probability why to go to all possible +fellow fellow products so if we include + + align:start position:0% +fellow fellow products so if we include + + + align:start position:0% +fellow fellow products so if we include +the cross-section go into all possible + + align:start position:0% +the cross-section go into all possible + + + align:start position:0% +the cross-section go into all possible +value product and so that probability + + align:start position:0% +value product and so that probability + + + align:start position:0% +value product and so that probability +just captured by the total cost Act + + align:start position:0% +just captured by the total cost Act + + + align:start position:0% +just captured by the total cost Act +so the total closed section before this + + align:start position:0% +so the total closed section before this + + + align:start position:0% +so the total closed section before this +process + + align:start position:0% +process + + + align:start position:0% +process +okay for the + + align:start position:0% +okay for the + + + align:start position:0% +okay for the +e + + align:start position:0% +e + + + align:start position:0% +e +e plus E minor is going to equivalent + + align:start position:0% +e plus E minor is going to equivalent + + + align:start position:0% +e plus E minor is going to equivalent +and then just including the total total + + align:start position:0% +and then just including the total total + + + align:start position:0% +and then just including the total total +cross-section + + align:start position:0% +cross-section + + + align:start position:0% +cross-section +so inclusive + + align:start position:0% + + + + align:start position:0% + +section + + align:start position:0% + + + + align:start position:0% + +for all hydrogen + + align:start position:0% +for all hydrogen + + + align:start position:0% +for all hydrogen +product okay + + align:start position:0% + + + + align:start position:0% + +so this way we can actually measure this + + align:start position:0% +so this way we can actually measure this + + + align:start position:0% +so this way we can actually measure this +process okay + + align:start position:0% +process okay + + + align:start position:0% +process okay +indirectly okay even though you don't + + align:start position:0% +indirectly okay even though you don't + + + align:start position:0% +indirectly okay even though you don't +directly measure the clocks + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +so now let's calculate the total + + align:start position:0% +so now let's calculate the total + + + align:start position:0% +so now let's calculate the total +cross-section + + align:start position:0% +cross-section + + + align:start position:0% +cross-section +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so now let's calculate the total + + align:start position:0% +so now let's calculate the total + + + align:start position:0% +so now let's calculate the total +cross-action + + align:start position:0% + + + + align:start position:0% + +and now we we also don't have a choice + + align:start position:0% +and now we we also don't have a choice + + + align:start position:0% +and now we we also don't have a choice +which Quark will be uh uh reproduced so + + align:start position:0% +which Quark will be uh uh reproduced so + + + align:start position:0% +which Quark will be uh uh reproduced so +we need to sum over + + align:start position:0% +we need to sum over + + + align:start position:0% +we need to sum over +the total cross-action + + align:start position:0% +the total cross-action + + + align:start position:0% +the total cross-action +for E plus e minus + + align:start position:0% +for E plus e minus + + + align:start position:0% +for E plus e minus +goes to say different kind of clocks + + align:start position:0% +goes to say different kind of clocks + + + align:start position:0% +goes to say different kind of clocks +so I equals one into different types of + + align:start position:0% +so I equals one into different types of + + + align:start position:0% +so I equals one into different types of +clocks + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +and uh so so each of them we can just + + align:start position:0% +and uh so so each of them we can just + + + align:start position:0% +and uh so so each of them we can just +write it down using our formula + + align:start position:0% +write it down using our formula + + + align:start position:0% +write it down using our formula +so the only difference okay the only + + align:start position:0% +so the only difference okay the only + + + align:start position:0% +so the only difference okay the only +difference + + align:start position:0% + + + + align:start position:0% + +so the same diagram applies + + align:start position:0% + + + + align:start position:0% + +the only difference is that the clock + + align:start position:0% +the only difference is that the clock + + + align:start position:0% +the only difference is that the clock +have different charge from the electron + + align:start position:0% +have different charge from the electron + + + align:start position:0% +have different charge from the electron +so here is ie + + align:start position:0% +so here is ie + + + align:start position:0% +so here is ie +comma mu + + align:start position:0% +comma mu + + + align:start position:0% +comma mu +here we should use the charge for the + + align:start position:0% +here we should use the charge for the + + + align:start position:0% +here we should use the charge for the +clock + + align:start position:0% +clock + + + align:start position:0% +clock +okay so that would be i q e + + align:start position:0% +okay so that would be i q e + + + align:start position:0% +okay so that would be i q e +gamma mu okay Q would be the Quark of + + align:start position:0% +gamma mu okay Q would be the Quark of + + + align:start position:0% +gamma mu okay Q would be the Quark of +the charge compared to the uh the charge + + align:start position:0% +the charge compared to the uh the charge + + + align:start position:0% +the charge compared to the uh the charge +of the electron okay + + align:start position:0% +of the electron okay + + + align:start position:0% +of the electron okay +so so then then what we get + + align:start position:0% +so so then then what we get + + + align:start position:0% +so so then then what we get +okay so so suppose + + align:start position:0% +okay so so suppose + + + align:start position:0% +okay so so suppose +Qi is the the charge for the clock Qi + + align:start position:0% +Qi is the the charge for the clock Qi + + + align:start position:0% +Qi is the the charge for the clock Qi +and then and then and then this gives + + align:start position:0% +and then and then and then this gives + + + align:start position:0% +and then and then and then this gives +you + + align:start position:0% +you + + + align:start position:0% +you +so this total is going to all hydrons + + align:start position:0% +so this total is going to all hydrons + + + align:start position:0% +so this total is going to all hydrons +okay + + align:start position:0% +okay + + + align:start position:0% +okay +two four hydraulics + + align:start position:0% + + + + align:start position:0% + +so this could be given by + + align:start position:0% +so this could be given by + + + align:start position:0% +so this could be given by +sum over different sum over the number + + align:start position:0% +sum over different sum over the number + + + align:start position:0% +sum over different sum over the number +of colors + + align:start position:0% +of colors + + + align:start position:0% +of colors +okay and C is the number of colors for + + align:start position:0% +okay and C is the number of colors for + + + align:start position:0% +okay and C is the number of colors for +each clock + + align:start position:0% +each clock + + + align:start position:0% +each clock +and then then the I will be the flavor + + align:start position:0% +and then then the I will be the flavor + + + align:start position:0% +and then then the I will be the flavor +now the I is the flavor of quark + + align:start position:0% + + + + align:start position:0% + +say whether it's the uh you crack or D + + align:start position:0% +say whether it's the uh you crack or D + + + align:start position:0% +say whether it's the uh you crack or D +Quark or Charm clock Etc and NC is the + + align:start position:0% +Quark or Charm clock Etc and NC is the + + + align:start position:0% +Quark or Charm clock Etc and NC is the +number of colors + + align:start position:0% +number of colors + + + align:start position:0% +number of colors +and then you have Qi Square + + align:start position:0% + + + + align:start position:0% + +and then you have Sigma e plus e minus + + align:start position:0% +and then you have Sigma e plus e minus + + + align:start position:0% +and then you have Sigma e plus e minus +2 mu plus mu minus + + align:start position:0% +2 mu plus mu minus + + + align:start position:0% +2 mu plus mu minus +okay the rest is the same + + align:start position:0% +okay the rest is the same + + + align:start position:0% +okay the rest is the same +so for each type of Quark this is + + align:start position:0% +so for each type of Quark this is + + + align:start position:0% +so for each type of Quark this is +exactly the same you just replace IQ + + align:start position:0% +exactly the same you just replace IQ + + + align:start position:0% +exactly the same you just replace IQ +this vertex by iqi and then you get the + + align:start position:0% +this vertex by iqi and then you get the + + + align:start position:0% +this vertex by iqi and then you get the +QI Square okay + + align:start position:0% + + + + align:start position:0% + +good yes + + align:start position:0% + + + + align:start position:0% + +no no that's a very complicated process + + align:start position:0% +no no that's a very complicated process + + + align:start position:0% +no no that's a very complicated process +we cannot uh yeah yeah that's a very + + align:start position:0% +we cannot uh yeah yeah that's a very + + + align:start position:0% +we cannot uh yeah yeah that's a very +complicated process it's a it's a huge + + align:start position:0% +complicated process it's a it's a huge + + + align:start position:0% +complicated process it's a it's a huge +uh it's a huge field yeah + + align:start position:0% +uh it's a huge field yeah + + + align:start position:0% +uh it's a huge field yeah +to study that yeah + + align:start position:0% + + + + align:start position:0% + +no you just measure you just match all + + align:start position:0% +no you just measure you just match all + + + align:start position:0% +no you just measure you just match all +possible products right + + align:start position:0% + + + + align:start position:0% + +no that's the only thing you can produce + + align:start position:0% + + + + align:start position:0% + +no no no no no no no no as I said + + align:start position:0% +no no no no no no no no as I said + + + align:start position:0% +no no no no no no no no as I said +earlier we only need to worry about this + + align:start position:0% +earlier we only need to worry about this + + + align:start position:0% +earlier we only need to worry about this +process and then this process into + + align:start position:0% +process and then this process into + + + align:start position:0% +process and then this process into +hydrons is complicated + + align:start position:0% +hydrons is complicated + + + align:start position:0% +hydrons is complicated +but this happens with probability one + + align:start position:0% +but this happens with probability one + + + align:start position:0% +but this happens with probability one +okay and so if we calculate this + + align:start position:0% +okay and so if we calculate this + + + align:start position:0% +okay and so if we calculate this +probability then we know the total + + align:start position:0% +probability then we know the total + + + align:start position:0% +probability then we know the total +probability to here yeah yeah + + align:start position:0% +probability to here yeah yeah + + + align:start position:0% +probability to here yeah yeah +yeah because this happens with + + align:start position:0% +yeah because this happens with + + + align:start position:0% +yeah because this happens with +probability one + + align:start position:0% +probability one + + + align:start position:0% +probability one +yes + + align:start position:0% + + + + align:start position:0% + +yes + + align:start position:0% +yes + + + align:start position:0% +yes +indeed that can happen but this is the + + align:start position:0% +indeed that can happen but this is the + + + align:start position:0% +indeed that can happen but this is the +leading process + + align:start position:0% +leading process + + + align:start position:0% +leading process +yeah this is the leading process + + align:start position:0% +yeah this is the leading process + + + align:start position:0% +yeah this is the leading process +yeah so this is the leading + + align:start position:0% +yeah so this is the leading + + + align:start position:0% +yeah so this is the leading +approximation yeah + + align:start position:0% + + + + align:start position:0% + +other questions + + align:start position:0% + + + + align:start position:0% + +okay so so now + + align:start position:0% +okay so so now + + + align:start position:0% +okay so so now +you're just given by this formula + + align:start position:0% +you're just given by this formula + + + align:start position:0% +you're just given by this formula +because uh you just multiply the QI + + align:start position:0% +because uh you just multiply the QI + + + align:start position:0% +because uh you just multiply the QI +Square + + align:start position:0% +Square + + + align:start position:0% +Square +to the to the total cross-section of the + + align:start position:0% +to the to the total cross-section of the + + + align:start position:0% +to the to the total cross-section of the +E plus image to Mu arm and then you sum + + align:start position:0% +E plus image to Mu arm and then you sum + + + align:start position:0% +E plus image to Mu arm and then you sum +all the all the flavors and times the + + align:start position:0% +all the all the flavors and times the + + + align:start position:0% +all the all the flavors and times the +number of the color + + align:start position:0% +number of the color + + + align:start position:0% +number of the color +okay the times the number of color + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +because the each + + align:start position:0% +because the each + + + align:start position:0% +because the each +or different colors have the same charge + + align:start position:0% +or different colors have the same charge + + + align:start position:0% +or different colors have the same charge +okay or different color have same charge + + align:start position:0% +okay or different color have same charge + + + align:start position:0% +okay or different color have same charge +so + + align:start position:0% + + + + align:start position:0% + +so now we can define a ratio + + align:start position:0% + + + + align:start position:0% + +so this is the same for everybody + + align:start position:0% +so this is the same for everybody + + + align:start position:0% +so this is the same for everybody +so this just factorized + + align:start position:0% +so this just factorized + + + align:start position:0% +so this just factorized +so we can define a ratio + + align:start position:0% +so we can define a ratio + + + align:start position:0% +so we can define a ratio +called the quantity code r + + align:start position:0% + + + + align:start position:0% + +code r + + align:start position:0% + + + + align:start position:0% + +is defined by + + align:start position:0% +is defined by + + + align:start position:0% +is defined by +Sigma e plus e minus those two hydrons + + align:start position:0% + + + + align:start position:0% + +divided by Sigma e plus e minus goes to + + align:start position:0% +divided by Sigma e plus e minus goes to + + + align:start position:0% +divided by Sigma e plus e minus goes to +Mu + + align:start position:0% +Mu + + + align:start position:0% +Mu +plus mu Mass + + align:start position:0% +plus mu Mass + + + align:start position:0% +plus mu Mass +and this is just given by Sum and C + + align:start position:0% +and this is just given by Sum and C + + + align:start position:0% +and this is just given by Sum and C +pounds some over eye flavor and the QI + + align:start position:0% +pounds some over eye flavor and the QI + + + align:start position:0% +pounds some over eye flavor and the QI +Square + + align:start position:0% + + + + align:start position:0% + +and this eye of course + + align:start position:0% +and this eye of course + + + align:start position:0% +and this eye of course +you should only sum over I which Allowed + + align:start position:0% +you should only sum over I which Allowed + + + align:start position:0% +you should only sum over I which Allowed +by your energy okay + + align:start position:0% +by your energy okay + + + align:start position:0% +by your energy okay +those cracks which are too heavy will + + align:start position:0% +those cracks which are too heavy will + + + align:start position:0% +those cracks which are too heavy will +not be created by your energy you're not + + align:start position:0% +not be created by your energy you're not + + + align:start position:0% +not be created by your energy you're not +including the sun okay + + align:start position:0% +including the sun okay + + + align:start position:0% +including the sun okay +so a flavor of quarks allowed + + align:start position:0% +so a flavor of quarks allowed + + + align:start position:0% +so a flavor of quarks allowed +by NH + + align:start position:0% + + + + align:start position:0% + +initial image + + align:start position:0% +initial image + + + align:start position:0% +initial image +okay if the quarks are too heavy then of + + align:start position:0% +okay if the quarks are too heavy then of + + + align:start position:0% +okay if the quarks are too heavy then of +course you cannot create them + + align:start position:0% +course you cannot create them + + + align:start position:0% +course you cannot create them +so now let's list + + align:start position:0% +so now let's list + + + align:start position:0% +so now let's list +now let's list the the clocks we know + + align:start position:0% +now let's list the the clocks we know + + + align:start position:0% +now let's list the the clocks we know +the process uh I will not do the + + align:start position:0% +the process uh I will not do the + + + align:start position:0% +the process uh I will not do the +final one so we have U clock D Quark + + align:start position:0% +final one so we have U clock D Quark + + + align:start position:0% +final one so we have U clock D Quark +strange Croc Chunk rock bottom clock and + + align:start position:0% +strange Croc Chunk rock bottom clock and + + + align:start position:0% +strange Croc Chunk rock bottom clock and +then there's a top clock the top clock + + align:start position:0% +then there's a top clock the top clock + + + align:start position:0% +then there's a top clock the top clock +is very heavy and its process will be um + + align:start position:0% +is very heavy and its process will be um + + + align:start position:0% +is very heavy and its process will be um +will be communicated so let's not worry + + align:start position:0% +will be communicated so let's not worry + + + align:start position:0% +will be communicated so let's not worry +about that + + align:start position:0% +about that + + + align:start position:0% +about that +so so then the charge for each of them + + align:start position:0% +so so then the charge for each of them + + + align:start position:0% +so so then the charge for each of them +so this is two-thirds + + align:start position:0% +so this is two-thirds + + + align:start position:0% +so this is two-thirds +so this is minus one third this is minus + + align:start position:0% +so this is minus one third this is minus + + + align:start position:0% +so this is minus one third this is minus +one third + + align:start position:0% +one third + + + align:start position:0% +one third +this is two thirds + + align:start position:0% +this is two thirds + + + align:start position:0% +this is two thirds +this is minus one set okay + + align:start position:0% +this is minus one set okay + + + align:start position:0% +this is minus one set okay +and then the mass twice of the mass + + align:start position:0% +and then the mass twice of the mass + + + align:start position:0% +and then the mass twice of the mass +so I just give you some rough number so + + align:start position:0% +so I just give you some rough number so + + + align:start position:0% +so I just give you some rough number so +you would be about a few Mev okay so so + + align:start position:0% +you would be about a few Mev okay so so + + + align:start position:0% +you would be about a few Mev okay so so +this is a few Meb + + align:start position:0% +this is a few Meb + + + align:start position:0% +this is a few Meb +so this again is a few Mev + + align:start position:0% + + + + align:start position:0% + +and so so so the strange will become + + align:start position:0% +and so so so the strange will become + + + align:start position:0% +and so so so the strange will become +strange is heavier twice is 1 9 PMB + + align:start position:0% +strange is heavier twice is 1 9 PMB + + + align:start position:0% +strange is heavier twice is 1 9 PMB +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and the charm + + align:start position:0% +and the charm + + + align:start position:0% +and the charm +the threshold is about 3.1 GV + + align:start position:0% +the threshold is about 3.1 GV + + + align:start position:0% +the threshold is about 3.1 GV +and the threshold for the bottom clock + + align:start position:0% +and the threshold for the bottom clock + + + align:start position:0% +and the threshold for the bottom clock +is about the line point five + + align:start position:0% + + + + align:start position:0% + +so now + + align:start position:0% +so now + + + align:start position:0% +so now +let's consider the value of r + + align:start position:0% +let's consider the value of r + + + align:start position:0% +let's consider the value of r +as a function of energy okay + + align:start position:0% +as a function of energy okay + + + align:start position:0% +as a function of energy okay +so then if you consider for s + + align:start position:0% +so then if you consider for s + + + align:start position:0% +so then if you consider for s +smaller than + + align:start position:0% +smaller than + + + align:start position:0% +smaller than +the the the uh uh the the charm says 3gb + + align:start position:0% +the the the uh uh the the charm says 3gb + + + align:start position:0% +the the the uh uh the the charm says 3gb +so in this case we can just produce + + align:start position:0% +so in this case we can just produce + + + align:start position:0% +so in this case we can just produce +UDS okay + + align:start position:0% +UDS okay + + + align:start position:0% +UDS okay +so in this case we have r equal to + + align:start position:0% +so in this case we have r equal to + + + align:start position:0% +so in this case we have r equal to +and see + + align:start position:0% +and see + + + align:start position:0% +and see +then times + + align:start position:0% +then times + + + align:start position:0% +then times +say this + + align:start position:0% +say this + + + align:start position:0% +say this +so this one two thirds and two one third + + align:start position:0% +so this one two thirds and two one third + + + align:start position:0% +so this one two thirds and two one third +so we have two three square plus twice + + align:start position:0% +so we have two three square plus twice + + + align:start position:0% +so we have two three square plus twice +Point third Square minus one so it's + + align:start position:0% +Point third Square minus one so it's + + + align:start position:0% +Point third Square minus one so it's +good okay + + align:start position:0% +good okay + + + align:start position:0% +good okay +so this is give you NC + + align:start position:0% +so this is give you NC + + + align:start position:0% +so this is give you NC +times two thirds + + align:start position:0% + + + + align:start position:0% + +and then for + + align:start position:0% +and then for + + + align:start position:0% +and then for +we would other others you cannot create + + align:start position:0% +we would other others you cannot create + + + align:start position:0% +we would other others you cannot create +okay and for square root S + + align:start position:0% + + + + align:start position:0% + +say between + + align:start position:0% +say between + + + align:start position:0% +say between +3G V + + align:start position:0% + + + + align:start position:0% + +and and the line 0.5 + + align:start position:0% +and and the line 0.5 + + + align:start position:0% +and and the line 0.5 +GV the threshold for producing the the + + align:start position:0% +GV the threshold for producing the the + + + align:start position:0% +GV the threshold for producing the the +bottom clock + + align:start position:0% +bottom clock + + + align:start position:0% +bottom clock +and then you can now you can create the + + align:start position:0% +and then you can now you can create the + + + align:start position:0% +and then you can now you can create the +charm clock + + align:start position:0% +charm clock + + + align:start position:0% +charm clock +so you just add another one third + + align:start position:0% +so you just add another one third + + + align:start position:0% +so you just add another one third +so and then now R become + + align:start position:0% +so and then now R become + + + align:start position:0% +so and then now R become +and c times 10 divided by 9. okay just + + align:start position:0% +and c times 10 divided by 9. okay just + + + align:start position:0% +and c times 10 divided by 9. okay just +add another two third Square here + + align:start position:0% +add another two third Square here + + + align:start position:0% +add another two third Square here +and then for now if you have square root + + align:start position:0% +and then for now if you have square root + + + align:start position:0% +and then for now if you have square root +S + + align:start position:0% +S + + + align:start position:0% +S +greater than 9.5 GB + + align:start position:0% + + + + align:start position:0% + +and then + + align:start position:0% +and then + + + align:start position:0% +and then +um + + align:start position:0% +um + + + align:start position:0% +um +then R now you can create the Bottom now + + align:start position:0% +then R now you can create the Bottom now + + + align:start position:0% +then R now you can create the Bottom now +okay so you add another one third Square + + align:start position:0% +okay so you add another one third Square + + + align:start position:0% +okay so you add another one third Square +so this r equal to q and c times + + align:start position:0% +so this r equal to q and c times + + + align:start position:0% +so this r equal to q and c times +10 divided by 9 + + align:start position:0% +10 divided by 9 + + + align:start position:0% +10 divided by 9 +plus another one third Square + + align:start position:0% +plus another one third Square + + + align:start position:0% +plus another one third Square +so they'll give you + + align:start position:0% +so they'll give you + + + align:start position:0% +so they'll give you +see 11 divided + + align:start position:0% +see 11 divided + + + align:start position:0% +see 11 divided +so now if you plot + + align:start position:0% + + + + align:start position:0% + +the r as a function + + align:start position:0% + + + + align:start position:0% + +say for square root S + + align:start position:0% +say for square root S + + + align:start position:0% +say for square root S +as measured by experiments + + align:start position:0% +as measured by experiments + + + align:start position:0% +as measured by experiments +okay so so you should see your Threshold + + align:start position:0% +okay so so you should see your Threshold + + + align:start position:0% +okay so so you should see your Threshold +at three + + align:start position:0% +at three + + + align:start position:0% +at three +a lot of threshold around the 10 + + align:start position:0% +a lot of threshold around the 10 + + + align:start position:0% +a lot of threshold around the 10 +okay yeah 9.5 say around 10 okay + + align:start position:0% +okay yeah 9.5 say around 10 okay + + + align:start position:0% +okay yeah 9.5 say around 10 okay +and then you see something like this + + align:start position:0% +and then you see something like this + + + align:start position:0% +and then you see something like this +yeah I'm just showing roughly okay you + + align:start position:0% +yeah I'm just showing roughly okay you + + + align:start position:0% +yeah I'm just showing roughly okay you +create something + + align:start position:0% +create something + + + align:start position:0% +create something +and then you + + align:start position:0% +and then you + + + align:start position:0% +and then you +something and then you have a large + + align:start position:0% +something and then you have a large + + + align:start position:0% +something and then you have a large +threshold and then you have a lot of + + align:start position:0% +threshold and then you have a lot of + + + align:start position:0% +threshold and then you have a lot of +stretch + + align:start position:0% + + + + align:start position:0% + +so it turns out the first nine is + + align:start position:0% +so it turns out the first nine is + + + align:start position:0% +so it turns out the first nine is +precisely at the two + + align:start position:0% +precisely at the two + + + align:start position:0% +precisely at the two +yeah I have to say precisely it's just + + align:start position:0% +yeah I have to say precisely it's just + + + align:start position:0% +yeah I have to say precisely it's just +say up to some Arrow bar okay and the + + align:start position:0% +say up to some Arrow bar okay and the + + + align:start position:0% +say up to some Arrow bar okay and the +other one is about say a little bit more + + align:start position:0% +other one is about say a little bit more + + + align:start position:0% +other one is about say a little bit more +than three + + align:start position:0% + + + + align:start position:0% + +and uh yeah + + align:start position:0% + + + + align:start position:0% + +a little bit more than three and then + + align:start position:0% +a little bit more than three and then + + + align:start position:0% +a little bit more than three and then +the four is one here + + align:start position:0% + + + + align:start position:0% + +anyway + + align:start position:0% +anyway + + + align:start position:0% +anyway +so + + align:start position:0% +so + + + align:start position:0% +so +so if you compare with these numbers + + align:start position:0% +so if you compare with these numbers + + + align:start position:0% +so if you compare with these numbers +and you conclude that NC is actually + + align:start position:0% +and you conclude that NC is actually + + + align:start position:0% +and you conclude that NC is actually +exactly + + align:start position:0% +exactly + + + align:start position:0% +exactly +yeah in C3 okay to be compatible with + + align:start position:0% +yeah in C3 okay to be compatible with + + + align:start position:0% +yeah in C3 okay to be compatible with +this experiment + + align:start position:0% + + + + align:start position:0% + +any questions on this + + align:start position:0% + + + + align:start position:0% + +yes + + align:start position:0% +yes + + + align:start position:0% +yes +yeah + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +going to high jumps yeah + + align:start position:0% + + + + align:start position:0% + +other questions + + align:start position:0% + + + + align:start position:0% + +okay good + + align:start position:0% +okay good + + + align:start position:0% +okay good +so so this way + + align:start position:0% +so so this way + + + align:start position:0% +so so this way +so this is a very nice + + align:start position:0% +so this is a very nice + + + align:start position:0% +so this is a very nice +simple uh uh uh even though this is a + + align:start position:0% +simple uh uh uh even though this is a + + + align:start position:0% +simple uh uh uh even though this is a +very simple process + + align:start position:0% +very simple process + + + align:start position:0% +very simple process +but actually uh uh have very important + + align:start position:0% +but actually uh uh have very important + + + align:start position:0% +but actually uh uh have very important +physical implications okay and uh in + + align:start position:0% +physical implications okay and uh in + + + align:start position:0% +physical implications okay and uh in +fact quite profound physical + + align:start position:0% +fact quite profound physical + + + align:start position:0% +fact quite profound physical +implications + + align:start position:0% + + + + align:start position:0% + +so we only have a few minutes left + + align:start position:0% +so we only have a few minutes left + + + align:start position:0% +so we only have a few minutes left +so let's + + align:start position:0% +so let's + + + align:start position:0% +so let's +say a few words regarding the + + align:start position:0% +say a few words regarding the + + + align:start position:0% +say a few words regarding the +next topic + + align:start position:0% + + + + align:start position:0% + +foreign + + align:start position:0% + + + + align:start position:0% + +okay so let's again consider this + + align:start position:0% +okay so let's again consider this + + + align:start position:0% +okay so let's again consider this +process + + align:start position:0% + + + + align:start position:0% + +of e plus + + align:start position:0% +of e plus + + + align:start position:0% +of e plus +E minor is going to Mu + + align:start position:0% + + + + align:start position:0% + +okay go into mu + + align:start position:0% +okay go into mu + + + align:start position:0% +okay go into mu +and then + + align:start position:0% +and then + + + align:start position:0% +and then +um + + align:start position:0% +um + + + align:start position:0% +um +so we have + + align:start position:0% +so we have + + + align:start position:0% +so we have +again this diagram + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +so suppose this is P1 P2 + + align:start position:0% +so suppose this is P1 P2 + + + align:start position:0% +so suppose this is P1 P2 +and the K1 + + align:start position:0% +and the K1 + + + align:start position:0% +and the K1 +the K2 + + align:start position:0% + + + + align:start position:0% + +so when we draw this diagram we take the + + align:start position:0% +so when we draw this diagram we take the + + + align:start position:0% +so when we draw this diagram we take the +time as going above so these are the + + align:start position:0% +time as going above so these are the + + + align:start position:0% +time as going above so these are the +initial State these are the final States + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +so now if we view this diagram sideways + + align:start position:0% +so now if we view this diagram sideways + + + align:start position:0% +so now if we view this diagram sideways +so if we view in this direction + + align:start position:0% +so if we view in this direction + + + align:start position:0% +so if we view in this direction +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so if you try to think that the time go + + align:start position:0% +so if you try to think that the time go + + + align:start position:0% +so if you try to think that the time go +into right direction say if you try to + + align:start position:0% +into right direction say if you try to + + + align:start position:0% +into right direction say if you try to +view it sideways + + align:start position:0% +view it sideways + + + align:start position:0% +view it sideways +and then then in this case we'll view + + align:start position:0% +and then then in this case we'll view + + + align:start position:0% +and then then in this case we'll view +the sideway + + align:start position:0% + + + + align:start position:0% + +okay and now this become my initial + + align:start position:0% +okay and now this become my initial + + + align:start position:0% +okay and now this become my initial +state + + align:start position:0% + + + + align:start position:0% + +so this is the initial State and this is + + align:start position:0% +so this is the initial State and this is + + + align:start position:0% +so this is the initial State and this is +still initial state + + align:start position:0% +still initial state + + + align:start position:0% +still initial state +let me see um oh + + align:start position:0% + + + + align:start position:0% + +one second let me see + + align:start position:0% + + + + align:start position:0% + +and then this is the initial State and + + align:start position:0% +and then this is the initial State and + + + align:start position:0% +and then this is the initial State and +this is the uh uh initial State + + align:start position:0% +this is the uh uh initial State + + + align:start position:0% +this is the uh uh initial State +um + + align:start position:0% + + + + align:start position:0% + +yeah let me show the arrow this way okay + + align:start position:0% + + + + align:start position:0% + +yeah it doesn't matter let's do the iron + + align:start position:0% +yeah it doesn't matter let's do the iron + + + align:start position:0% +yeah it doesn't matter let's do the iron +this way so so that this is the uh this + + align:start position:0% +this way so so that this is the uh this + + + align:start position:0% +this way so so that this is the uh this +is the MU this is the MU plus okay + + align:start position:0% +is the MU this is the MU plus okay + + + align:start position:0% +is the MU this is the MU plus okay +so so this is and now let's view this + + align:start position:0% +so so this is and now let's view this + + + align:start position:0% +so so this is and now let's view this +way + + align:start position:0% +way + + + align:start position:0% +way +and now this is nuke you have initial + + align:start position:0% +and now this is nuke you have initial + + + align:start position:0% +and now this is nuke you have initial +initial electron and then you have + + align:start position:0% +initial electron and then you have + + + align:start position:0% +initial electron and then you have +initial muon okay and then + + align:start position:0% +initial muon okay and then + + + align:start position:0% +initial muon okay and then +this become a process e minus plus mu + + align:start position:0% +this become a process e minus plus mu + + + align:start position:0% +this become a process e minus plus mu +minus going to e minus and mu minus + + align:start position:0% +minus going to e minus and mu minus + + + align:start position:0% +minus going to e minus and mu minus +okay because this is the final particle + + align:start position:0% +okay because this is the final particle + + + align:start position:0% +okay because this is the final particle +now going out would be the particle and + + align:start position:0% +now going out would be the particle and + + + align:start position:0% +now going out would be the particle and +this fellow particle going out would be + + align:start position:0% +this fellow particle going out would be + + + align:start position:0% +this fellow particle going out would be +a particle and then then the final will + + align:start position:0% +a particle and then then the final will + + + align:start position:0% +a particle and then then the final will +be the electron and the muon okay + + align:start position:0% + + + + align:start position:0% + +so and then and then you get the process + + align:start position:0% +so and then and then you get the process + + + align:start position:0% +so and then and then you get the process +B + + align:start position:0% +B + + + align:start position:0% +B +that means the diagram when you view the + + align:start position:0% +that means the diagram when you view the + + + align:start position:0% +that means the diagram when you view the +sideways then you have a diagram like + + align:start position:0% +sideways then you have a diagram like + + + align:start position:0% +sideways then you have a diagram like +this if I choose using our again time + + align:start position:0% +this if I choose using our again time + + + align:start position:0% +this if I choose using our again time +going to up + + align:start position:0% + + + + align:start position:0% + +then this is like that + + align:start position:0% +then this is like that + + + align:start position:0% +then this is like that +now this is e minus E minus mu minus + + align:start position:0% +now this is e minus E minus mu minus + + + align:start position:0% +now this is e minus E minus mu minus +okay + + align:start position:0% + + + + align:start position:0% + +so now you wonder + + align:start position:0% +so now you wonder + + + align:start position:0% +so now you wonder +whether there's some relation + + align:start position:0% +whether there's some relation + + + align:start position:0% +whether there's some relation +between these two process okay + + align:start position:0% +between these two process okay + + + align:start position:0% +between these two process okay +whether there's some a relation between + + align:start position:0% +whether there's some a relation between + + + align:start position:0% +whether there's some a relation between +this process we do from you just + + align:start position:0% +this process we do from you just + + + align:start position:0% +this process we do from you just +exchange initial state to the final + + align:start position:0% +exchange initial state to the final + + + align:start position:0% +exchange initial state to the final +state + + align:start position:0% +state + + + align:start position:0% +state +so it turns out actually there's a very + + align:start position:0% +so it turns out actually there's a very + + + align:start position:0% +so it turns out actually there's a very +nice relation between them okay if you + + align:start position:0% +nice relation between them okay if you + + + align:start position:0% +nice relation between them okay if you +know one of them you can try to use the + + align:start position:0% +know one of them you can try to use the + + + align:start position:0% +know one of them you can try to use the +other uh can help you deduce the other + + align:start position:0% +other uh can help you deduce the other + + + align:start position:0% +other uh can help you deduce the other +which uh or or we are running out of + + align:start position:0% +which uh or or we are running out of + + + align:start position:0% +which uh or or we are running out of +time so we will do it the next time okay \ No newline at end of file diff --git a/tpaE_C8rqf8.txt b/tpaE_C8rqf8.txt new file mode 100644 index 0000000000000000000000000000000000000000..b9f16ac099ced211cb9ca847791ad7ad3a6716a7 --- /dev/null +++ b/tpaE_C8rqf8.txt @@ -0,0 +1,859 @@ +align:start position:0% + +we now continue with our example and + + align:start position:0% +we now continue with our example and + + + align:start position:0% +we now continue with our example and +turn to the performance evaluation + + align:start position:0% +turn to the performance evaluation + + + align:start position:0% +turn to the performance evaluation +question as you recall we have a theta + + align:start position:0% +question as you recall we have a theta + + + align:start position:0% +question as you recall we have a theta +that has a certain prior distribution + + align:start position:0% +that has a certain prior distribution + + + align:start position:0% +that has a certain prior distribution +were given a model for the observations + + align:start position:0% +were given a model for the observations + + + align:start position:0% +were given a model for the observations +we came up with a joint distribution for + + align:start position:0% +we came up with a joint distribution for + + + align:start position:0% +we came up with a joint distribution for +X and theta which was uniform on this + + align:start position:0% +X and theta which was uniform on this + + + align:start position:0% +X and theta which was uniform on this +particular shape and we found that the + + align:start position:0% +particular shape and we found that the + + + align:start position:0% +particular shape and we found that the +least mean square system ATAR namely the + + align:start position:0% +least mean square system ATAR namely the + + + align:start position:0% +least mean square system ATAR namely the +conditional expectation of theta given + + align:start position:0% +conditional expectation of theta given + + + align:start position:0% +conditional expectation of theta given +any particular value of x is given by + + align:start position:0% +any particular value of x is given by + + + align:start position:0% +any particular value of x is given by +this particular piecewise linear + + align:start position:0% +this particular piecewise linear + + + align:start position:0% +this particular piecewise linear +function now let us look at the + + align:start position:0% +function now let us look at the + + + align:start position:0% +function now let us look at the +performance of this estimator we judge + + align:start position:0% +performance of this estimator we judge + + + align:start position:0% +performance of this estimator we judge +the performance given any particular + + align:start position:0% +the performance given any particular + + + align:start position:0% +the performance given any particular +value of x by looking at the + + align:start position:0% +value of x by looking at the + + + align:start position:0% +value of x by looking at the +corresponding mean squared error which + + align:start position:0% +corresponding mean squared error which + + + align:start position:0% +corresponding mean squared error which +is the square of the distance between + + align:start position:0% +is the square of the distance between + + + align:start position:0% +is the square of the distance between +the unknown parameter and the estimate + + align:start position:0% +the unknown parameter and the estimate + + + align:start position:0% +the unknown parameter and the estimate +with which we came up and as we have + + align:start position:0% +with which we came up and as we have + + + align:start position:0% +with which we came up and as we have +discussed this is the same as the + + align:start position:0% +discussed this is the same as the + + + align:start position:0% +discussed this is the same as the +variance of theta but in the conditional + + align:start position:0% +variance of theta but in the conditional + + + align:start position:0% +variance of theta but in the conditional +universe where X has been observed + + align:start position:0% +universe where X has been observed + + + align:start position:0% +universe where X has been observed +it's the variance of the conditional + + align:start position:0% +it's the variance of the conditional + + + align:start position:0% +it's the variance of the conditional +distribution of theta as we have + + align:start position:0% +distribution of theta as we have + + + align:start position:0% +distribution of theta as we have +discussed if I tell you that X takes on + + align:start position:0% +discussed if I tell you that X takes on + + + align:start position:0% +discussed if I tell you that X takes on +this particular value theta is uniform + + align:start position:0% +this particular value theta is uniform + + + align:start position:0% +this particular value theta is uniform +on this interval therefore the + + align:start position:0% +on this interval therefore the + + + align:start position:0% +on this interval therefore the +conditional variance of theta is the + + align:start position:0% +conditional variance of theta is the + + + align:start position:0% +conditional variance of theta is the +variance of a uniform on an interval of + + align:start position:0% +variance of a uniform on an interval of + + + align:start position:0% +variance of a uniform on an interval of +this particular length now we know that + + align:start position:0% +this particular length now we know that + + + align:start position:0% +this particular length now we know that +the variance of a uniform on an interval + + align:start position:0% +the variance of a uniform on an interval + + + align:start position:0% +the variance of a uniform on an interval +from A to B is equal to B minus a + + align:start position:0% +from A to B is equal to B minus a + + + align:start position:0% +from A to B is equal to B minus a +squared divided by 12 in this particular + + align:start position:0% +squared divided by 12 in this particular + + + align:start position:0% +squared divided by 12 in this particular +instance the interval has length 2 + + align:start position:0% +instance the interval has length 2 + + + align:start position:0% +instance the interval has length 2 +therefore we have 2 squared divided by + + align:start position:0% +therefore we have 2 squared divided by + + + align:start position:0% +therefore we have 2 squared divided by +12 so the variance is equal to one-third + + align:start position:0% +12 so the variance is equal to one-third + + + align:start position:0% +12 so the variance is equal to one-third +this is what we get when the picture is + + align:start position:0% +this is what we get when the picture is + + + align:start position:0% +this is what we get when the picture is +of this type on the other hand if X + + align:start position:0% +of this type on the other hand if X + + + align:start position:0% +of this type on the other hand if X +falls in this range then this interval + + align:start position:0% +falls in this range then this interval + + + align:start position:0% +falls in this range then this interval +on which theta is now constrained to + + align:start position:0% +on which theta is now constrained to + + + align:start position:0% +on which theta is now constrained to +live has a smaller length and we're + + align:start position:0% +live has a smaller length and we're + + + align:start position:0% +live has a smaller length and we're +going to get a different variance so in + + align:start position:0% +going to get a different variance so in + + + align:start position:0% +going to get a different variance so in +order to keep track let us come up with + + align:start position:0% +order to keep track let us come up with + + + align:start position:0% +order to keep track let us come up with +a plot when x is between 5 & 9 + + align:start position:0% +a plot when x is between 5 & 9 + + + align:start position:0% +a plot when x is between 5 & 9 +theta has a conditioned distribution + + align:start position:0% +theta has a conditioned distribution + + + align:start position:0% +theta has a conditioned distribution +which is uniform on an interval of + + align:start position:0% +which is uniform on an interval of + + + align:start position:0% +which is uniform on an interval of +length 2 and the variance of 1/3 and + + align:start position:0% +length 2 and the variance of 1/3 and + + + align:start position:0% +length 2 and the variance of 1/3 and +therefore the variance is constant takes + + align:start position:0% +therefore the variance is constant takes + + + align:start position:0% +therefore the variance is constant takes +this value at the extreme case when X is + + align:start position:0% +this value at the extreme case when X is + + + align:start position:0% +this value at the extreme case when X is +equal to 3 then this interval has zero + + align:start position:0% +equal to 3 then this interval has zero + + + align:start position:0% +equal to 3 then this interval has zero +lengths in fact we have perfect + + align:start position:0% +lengths in fact we have perfect + + + align:start position:0% +lengths in fact we have perfect +certainty about the value of theta if X + + align:start position:0% +certainty about the value of theta if X + + + align:start position:0% +certainty about the value of theta if X +is equal to 3 then we know that theta is + + align:start position:0% +is equal to 3 then we know that theta is + + + align:start position:0% +is equal to 3 then we know that theta is +equal to 4 there is no uncertainty + + align:start position:0% +equal to 4 there is no uncertainty + + + align:start position:0% +equal to 4 there is no uncertainty +there's zero variance what happens in + + align:start position:0% +there's zero variance what happens in + + + align:start position:0% +there's zero variance what happens in +between and as we increase X moving away + + align:start position:0% +between and as we increase X moving away + + + align:start position:0% +between and as we increase X moving away +from 3 the length of this interval + + align:start position:0% +from 3 the length of this interval + + + align:start position:0% +from 3 the length of this interval +increases linearly with X and this means + + align:start position:0% +increases linearly with X and this means + + + align:start position:0% +increases linearly with X and this means +that the variance increases + + align:start position:0% +that the variance increases + + + align:start position:0% +that the variance increases +quadratically with X so we have a + + align:start position:0% +quadratically with X so we have a + + + align:start position:0% +quadratically with X so we have a +quadratic that starts at 0 and rises to + + align:start position:0% +quadratic that starts at 0 and rises to + + + align:start position:0% +quadratic that starts at 0 and rises to +this value and by symmetric argument + + align:start position:0% +this value and by symmetric argument + + + align:start position:0% +this value and by symmetric argument +on the other side we also get a function + + align:start position:0% +on the other side we also get a function + + + align:start position:0% +on the other side we also get a function +which is 0 at 11 and which rises + + align:start position:0% +which is 0 at 11 and which rises + + + align:start position:0% +which is 0 at 11 and which rises +quadratically as X gets reduced from 11 + + align:start position:0% +quadratically as X gets reduced from 11 + + + align:start position:0% +quadratically as X gets reduced from 11 +to 9 so this is a complete plot of the + + align:start position:0% +to 9 so this is a complete plot of the + + + align:start position:0% +to 9 so this is a complete plot of the +conditional variance of theta as a + + align:start position:0% +conditional variance of theta as a + + + align:start position:0% +conditional variance of theta as a +function of the particular observation + + align:start position:0% +function of the particular observation + + + align:start position:0% +function of the particular observation +that we have obtained we notice that + + align:start position:0% +that we have obtained we notice that + + + align:start position:0% +that we have obtained we notice that +some X's are more favorable than others + + align:start position:0% +some X's are more favorable than others + + + align:start position:0% +some X's are more favorable than others +an observation equal to 3 is extremely + + align:start position:0% +an observation equal to 3 is extremely + + + align:start position:0% +an observation equal to 3 is extremely +favorable because it tells us + + align:start position:0% +favorable because it tells us + + + align:start position:0% +favorable because it tells us +unambiguously the value of theta but + + align:start position:0% +unambiguously the value of theta but + + + align:start position:0% +unambiguously the value of theta but +other choices of X other possible + + align:start position:0% +other choices of X other possible + + + align:start position:0% +other choices of X other possible +observations we lead to more uncertainty + + align:start position:0% +observations we lead to more uncertainty + + + align:start position:0% +observations we lead to more uncertainty +in theta and this is reflected in this + + align:start position:0% +in theta and this is reflected in this + + + align:start position:0% +in theta and this is reflected in this +diagram in case we're now interested in + + align:start position:0% +diagram in case we're now interested in + + + align:start position:0% +diagram in case we're now interested in +the overall mean squared error then we + + align:start position:0% +the overall mean squared error then we + + + align:start position:0% +the overall mean squared error then we +have to calculate the average of this + + align:start position:0% +have to calculate the average of this + + + align:start position:0% +have to calculate the average of this +conditional variance where the average + + align:start position:0% +conditional variance where the average + + + align:start position:0% +conditional variance where the average +is taken over all values of X this is + + align:start position:0% +is taken over all values of X this is + + + align:start position:0% +is taken over all values of X this is +going to be an integral of the + + align:start position:0% +going to be an integral of the + + + align:start position:0% +going to be an integral of the +conditional variance of theta integrated + + align:start position:0% +conditional variance of theta integrated + + + align:start position:0% +conditional variance of theta integrated +over all possibilities for X but of + + align:start position:0% +over all possibilities for X but of + + + align:start position:0% +over all possibilities for X but of +course each possibility of X has to be + + align:start position:0% +course each possibility of X has to be + + + align:start position:0% +course each possibility of X has to be +weighted + + align:start position:0% +weighted + + + align:start position:0% +weighted +according to the corresponding + + align:start position:0% +according to the corresponding + + + align:start position:0% +according to the corresponding +probability or in this case probability + + align:start position:0% +probability or in this case probability + + + align:start position:0% +probability or in this case probability +density function of X what is the PDF of + + align:start position:0% +density function of X what is the PDF of + + + align:start position:0% +density function of X what is the PDF of +X it is not given to us but it is + + align:start position:0% +X it is not given to us but it is + + + align:start position:0% +X it is not given to us but it is +something that can be easily determined + + align:start position:0% +something that can be easily determined + + + align:start position:0% +something that can be easily determined +from what we have already done + + align:start position:0% +from what we have already done + + + align:start position:0% +from what we have already done +we know the Joint Distribution of theta + + align:start position:0% +we know the Joint Distribution of theta + + + align:start position:0% +we know the Joint Distribution of theta +and X and whenever we know the joint we + + align:start position:0% +and X and whenever we know the joint we + + + align:start position:0% +and X and whenever we know the joint we +can also find the marginal so once we + + align:start position:0% +can also find the marginal so once we + + + align:start position:0% +can also find the marginal so once we +find the marginal PDF of X then we can + + align:start position:0% +find the marginal PDF of X then we can + + + align:start position:0% +find the marginal PDF of X then we can +plug it in multiplied by this function + + align:start position:0% +plug it in multiplied by this function + + + align:start position:0% +plug it in multiplied by this function +that we have already obtained carry out + + align:start position:0% +that we have already obtained carry out + + + align:start position:0% +that we have already obtained carry out +the integration and we will end up with + + align:start position:0% +the integration and we will end up with + + + align:start position:0% +the integration and we will end up with +a numerical value since it is an average + + align:start position:0% +a numerical value since it is an average + + + align:start position:0% +a numerical value since it is an average +of what we have here it's going to end + + align:start position:0% +of what we have here it's going to end + + + align:start position:0% +of what we have here it's going to end +up being some number between 0 and 1/3 + + align:start position:0% +up being some number between 0 and 1/3 + + + align:start position:0% +up being some number between 0 and 1/3 +it's the average of these values and + + align:start position:0% +it's the average of these values and + + + align:start position:0% +it's the average of these values and +closer to 1/3 rather than to 0 and this + + align:start position:0% +closer to 1/3 rather than to 0 and this + + + align:start position:0% +closer to 1/3 rather than to 0 and this +would complete the way that the + + align:start position:0% +would complete the way that the + + + align:start position:0% +would complete the way that the +performance of a particular estimator + + align:start position:0% +performance of a particular estimator + + + align:start position:0% +performance of a particular estimator +gets evaluated \ No newline at end of file diff --git a/turMcLH-o_o.txt b/turMcLH-o_o.txt new file mode 100644 index 0000000000000000000000000000000000000000..fd0655f1c12315aaacb7fea4579acaf0524d76ce --- /dev/null +++ b/turMcLH-o_o.txt @@ -0,0 +1,16939 @@ +align:start position:0% + +The following content is provided under + + align:start position:0% +The following content is provided under + + + align:start position:0% +The following content is provided under +a Creative Common license. Your support + + align:start position:0% +a Creative Common license. Your support + + + align:start position:0% +a Creative Common license. Your support +will help MIT Open Courseware continue + + align:start position:0% +will help MIT Open Courseware continue + + + align:start position:0% +will help MIT Open Courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free. To make a donation + + align:start position:0% +resources for free. To make a donation + + + align:start position:0% +resources for free. To make a donation +or to view additional materials from + + align:start position:0% +or to view additional materials from + + + align:start position:0% +or to view additional materials from +hundreds of MIT courses, visit MIT Open + + align:start position:0% +hundreds of MIT courses, visit MIT Open + + + align:start position:0% +hundreds of MIT courses, visit MIT Open +Courseware at ocw.mmit.edu. + + align:start position:0% + + + + align:start position:0% + +My name is David Hart for those of you + + align:start position:0% +My name is David Hart for those of you + + + align:start position:0% +My name is David Hart for those of you +who I haven't met yet. And uh uh I'm + + align:start position:0% +who I haven't met yet. And uh uh I'm + + + align:start position:0% +who I haven't met yet. And uh uh I'm +filling in for for Dwayne Bonding today + + align:start position:0% +filling in for for Dwayne Bonding today + + + align:start position:0% +filling in for for Dwayne Bonding today +or sitting in or or guest lecturing + + align:start position:0% +or sitting in or or guest lecturing + + + align:start position:0% +or sitting in or or guest lecturing +whichever you want to call. You're a co- + + align:start position:0% +whichever you want to call. You're a co- + + + align:start position:0% +whichever you want to call. You're a co- +lecturer. Oh yeah, I'm a co- lecturer. + + align:start position:0% +lecturer. Oh yeah, I'm a co- lecturer. + + + align:start position:0% +lecturer. Oh yeah, I'm a co- lecturer. +Yeah. Yeah, that's right. No, I'm guest + + align:start position:0% +Yeah. Yeah, that's right. No, I'm guest + + + align:start position:0% +Yeah. Yeah, that's right. No, I'm guest +lecturing because well, you know the + + align:start position:0% +lecturing because well, you know the + + + align:start position:0% +lecturing because well, you know the +story. So uh uh I think my role today is + + align:start position:0% +story. So uh uh I think my role today is + + + align:start position:0% +story. So uh uh I think my role today is +to + + align:start position:0% +to + + + align:start position:0% +to +uh in some ways repeat what uh Dwayne + + align:start position:0% +uh in some ways repeat what uh Dwayne + + + align:start position:0% +uh in some ways repeat what uh Dwayne +Bonding has talked about in the first + + align:start position:0% +Bonding has talked about in the first + + + align:start position:0% +Bonding has talked about in the first +two lectures from a little bit more of a + + align:start position:0% +two lectures from a little bit more of a + + + align:start position:0% +two lectures from a little bit more of a +mechanical engineering perspective. But + + align:start position:0% +mechanical engineering perspective. But + + + align:start position:0% +mechanical engineering perspective. But +I'm going to also throw in some things. + + align:start position:0% +I'm going to also throw in some things. + + + align:start position:0% +I'm going to also throw in some things. +Um, you might just say a personal + + align:start position:0% +Um, you might just say a personal + + + align:start position:0% +Um, you might just say a personal +perspective on the problem. Um, and uh, + + align:start position:0% +perspective on the problem. Um, and uh, + + + align:start position:0% +perspective on the problem. Um, and uh, +uh, I I've got too much to try and do in + + align:start position:0% +uh, I I've got too much to try and do in + + + align:start position:0% +uh, I I've got too much to try and do in +one lecture, but that's sort of typical + + align:start position:0% +one lecture, but that's sort of typical + + + align:start position:0% +one lecture, but that's sort of typical +of me anyway. Uh, but the notes are on + + align:start position:0% +of me anyway. Uh, but the notes are on + + + align:start position:0% +of me anyway. Uh, but the notes are on +the on the web if you want for the + + align:start position:0% +the on the web if you want for the + + + align:start position:0% +the on the web if you want for the +things I have to skip over. Um, now the + + align:start position:0% +things I have to skip over. Um, now the + + + align:start position:0% +things I have to skip over. Um, now the +first part of the lecture is to to + + align:start position:0% +first part of the lecture is to to + + + align:start position:0% +first part of the lecture is to to +notice this scene. And this is someone + + align:start position:0% +notice this scene. And this is someone + + + align:start position:0% +notice this scene. And this is someone +was pointing out to me the other day + + align:start position:0% +was pointing out to me the other day + + + align:start position:0% +was pointing out to me the other day +said, "You must be tough for you this + + align:start position:0% +said, "You must be tough for you this + + + align:start position:0% +said, "You must be tough for you this +summer because you go between these + + align:start position:0% +summer because you go between these + + + align:start position:0% +summer because you go between these +these this winter because you go between + + align:start position:0% +these this winter because you go between + + + align:start position:0% +these this winter because you go between +these extreme environments." So I found + + align:start position:0% +these extreme environments." So I found + + + align:start position:0% +these extreme environments." So I found +this picture of sort of what I'll call a + + align:start position:0% +this picture of sort of what I'll call a + + + align:start position:0% +this picture of sort of what I'll call a +tree tunnel. Does anybody know where + + align:start position:0% +tree tunnel. Does anybody know where + + + align:start position:0% +tree tunnel. Does anybody know where +this picture was + + align:start position:0% + + + + align:start position:0% + +taken in January? + + align:start position:0% + + + + align:start position:0% + +It wasn't at MIT. It's a little washed + + align:start position:0% +It wasn't at MIT. It's a little washed + + + align:start position:0% +It wasn't at MIT. It's a little washed +out so you can't see what these these + + align:start position:0% +out so you can't see what these these + + + align:start position:0% +out so you can't see what these these +things are off in the distance. + + align:start position:0% +things are off in the distance. + + + align:start position:0% +things are off in the distance. +If you saw those, you'd probably know in + + align:start position:0% +If you saw those, you'd probably know in + + + align:start position:0% +If you saw those, you'd probably know in +an instant if you know + + align:start position:0% +an instant if you know + + + align:start position:0% +an instant if you know +anybody in Singapore know what that + + align:start position:0% +anybody in Singapore know what that + + + align:start position:0% +anybody in Singapore know what that +picture might be + + align:start position:0% +picture might be + + + align:start position:0% +picture might be +taken. Oh, come + + align:start position:0% +taken. Oh, come + + + align:start position:0% +taken. Oh, come +on. All right. Where do you think this + + align:start position:0% +on. All right. Where do you think this + + + align:start position:0% +on. All right. Where do you think this +picture was taken? + + align:start position:0% +picture was taken? + + + align:start position:0% +picture was taken? +Not. All right. Okay. So, here's a tree + + align:start position:0% +Not. All right. Okay. So, here's a tree + + + align:start position:0% +Not. All right. Okay. So, here's a tree +tunnel in Actton, Massachusetts in + + align:start position:0% +tunnel in Actton, Massachusetts in + + + align:start position:0% +tunnel in Actton, Massachusetts in +January. And here's a tree tunnel in on + + align:start position:0% +January. And here's a tree tunnel in on + + + align:start position:0% +January. And here's a tree tunnel in on +Sentosa Island in Singapore in January. + + align:start position:0% +Sentosa Island in Singapore in January. + + + align:start position:0% +Sentosa Island in Singapore in January. +Just about the same time, same kind of + + align:start position:0% +Just about the same time, same kind of + + + align:start position:0% +Just about the same time, same kind of +view. The difference is that those are + + align:start position:0% +view. The difference is that those are + + + align:start position:0% +view. The difference is that those are +probably the second largest collection + + align:start position:0% +probably the second largest collection + + + align:start position:0% +probably the second largest collection +of container ships in the world. + + align:start position:0% +of container ships in the world. + + + align:start position:0% +of container ships in the world. +Something like that, which is the main + + align:start position:0% +Something like that, which is the main + + + align:start position:0% +Something like that, which is the main +uh landscape feature off of that coast + + align:start position:0% +uh landscape feature off of that coast + + + align:start position:0% +uh landscape feature off of that coast +of + + align:start position:0% +of + + + align:start position:0% +of +Singapore. Okay, just to let everybody + + align:start position:0% +Singapore. Okay, just to let everybody + + + align:start position:0% +Singapore. Okay, just to let everybody +know what the other side is is enjoying + + align:start position:0% +know what the other side is is enjoying + + + align:start position:0% +know what the other side is is enjoying +on their + + align:start position:0% +on their + + + align:start position:0% +on their +weekends. So, um here's what I want to + + align:start position:0% +weekends. So, um here's what I want to + + + align:start position:0% +weekends. So, um here's what I want to +uh try to do today. Okay, I want to uh + + align:start position:0% +uh try to do today. Okay, I want to uh + + + align:start position:0% +uh try to do today. Okay, I want to uh +go back and talk a little bit more about + + align:start position:0% +go back and talk a little bit more about + + + align:start position:0% +go back and talk a little bit more about +process definitions from the point of + + align:start position:0% +process definitions from the point of + + + align:start position:0% +process definitions from the point of +view of geometric change of an object. + + align:start position:0% +view of geometric change of an object. + + + align:start position:0% +view of geometric change of an object. +And I think Dwayne has already talked + + align:start position:0% +And I think Dwayne has already talked + + + align:start position:0% +And I think Dwayne has already talked +about this a fair amount, but I want to + + align:start position:0% +about this a fair amount, but I want to + + + align:start position:0% +about this a fair amount, but I want to +relate it to that model or that view of + + align:start position:0% +relate it to that model or that view of + + + align:start position:0% +relate it to that model or that view of +processes to a couple key mechanical + + align:start position:0% +processes to a couple key mechanical + + + align:start position:0% +processes to a couple key mechanical +processes uh as examples. And then + + align:start position:0% +processes uh as examples. And then + + + align:start position:0% +processes uh as examples. And then +something that we always do is talk + + align:start position:0% +something that we always do is talk + + + align:start position:0% +something that we always do is talk +about this taxonomy for control. It's + + align:start position:0% +about this taxonomy for control. It's + + + align:start position:0% +about this taxonomy for control. It's +it's a framework. It's it's all these + + align:start position:0% +it's a framework. It's it's all these + + + align:start position:0% +it's a framework. It's it's all these +these rather uh abstract terms that uh + + align:start position:0% +these rather uh abstract terms that uh + + + align:start position:0% +these rather uh abstract terms that uh +say here's a way for you to think about + + align:start position:0% +say here's a way for you to think about + + + align:start position:0% +say here's a way for you to think about +every process that's ever been invented + + align:start position:0% +every process that's ever been invented + + + align:start position:0% +every process that's ever been invented +and try to understand how it relates to + + align:start position:0% +and try to understand how it relates to + + + align:start position:0% +and try to understand how it relates to +some other process with respect to + + align:start position:0% +some other process with respect to + + + align:start position:0% +some other process with respect to +things that affect how we control the + + align:start position:0% +things that affect how we control the + + + align:start position:0% +things that affect how we control the +process. So that's our taxonomy for + + align:start position:0% +process. So that's our taxonomy for + + + align:start position:0% +process. So that's our taxonomy for +control. And then we go through a couple + + align:start position:0% +control. And then we go through a couple + + + align:start position:0% +control. And then we go through a couple +mechanical examples. I'll use the + + align:start position:0% +mechanical examples. I'll use the + + + align:start position:0% +mechanical examples. I'll use the +process of simple machining, a turning + + align:start position:0% +process of simple machining, a turning + + + align:start position:0% +process of simple machining, a turning +process, a bending process, and a + + align:start position:0% +process, a bending process, and a + + + align:start position:0% +process, a bending process, and a +molding process. Um we used to have a + + align:start position:0% +molding process. Um we used to have a + + + align:start position:0% +molding process. Um we used to have a +lab in in the course that we did. Uh in + + align:start position:0% +lab in in the course that we did. Uh in + + + align:start position:0% +lab in in the course that we did. Uh in +fact the guys in Singapore did it this + + align:start position:0% +fact the guys in Singapore did it this + + + align:start position:0% +fact the guys in Singapore did it this +summer as part of their summer + + align:start position:0% +summer as part of their summer + + + align:start position:0% +summer as part of their summer +orientation. They actually did this lab + + align:start position:0% +orientation. They actually did this lab + + + align:start position:0% +orientation. They actually did this lab +where they they went through and made + + align:start position:0% +where they they went through and made + + + align:start position:0% +where they they went through and made +parts using these three + + align:start position:0% +parts using these three + + + align:start position:0% +parts using these three +processes and we studied the process + + align:start position:0% +processes and we studied the process + + + align:start position:0% +processes and we studied the process +control aspects of that. And they're + + align:start position:0% +control aspects of that. And they're + + + align:start position:0% +control aspects of that. And they're +simple enough they're they're they're + + align:start position:0% +simple enough they're they're they're + + + align:start position:0% +simple enough they're they're they're +ubiquitous processes but they also can + + align:start position:0% +ubiquitous processes but they also can + + + align:start position:0% +ubiquitous processes but they also can +be reduced uh to some simple enough + + align:start position:0% +be reduced uh to some simple enough + + + align:start position:0% +be reduced uh to some simple enough +concepts that you can try to understand + + align:start position:0% +concepts that you can try to understand + + + align:start position:0% +concepts that you can try to understand +this this idea of the origins of + + align:start position:0% +this this idea of the origins of + + + align:start position:0% +this this idea of the origins of +variation. Why did things vary? Instead + + align:start position:0% +variation. Why did things vary? Instead + + + align:start position:0% +variation. Why did things vary? Instead +of it being a purely um uh uh random + + align:start position:0% +of it being a purely um uh uh random + + + align:start position:0% +of it being a purely um uh uh random +event instead of sort of throwing up + + align:start position:0% +event instead of sort of throwing up + + + align:start position:0% +event instead of sort of throwing up +your hands and saying I have no idea why + + align:start position:0% +your hands and saying I have no idea why + + + align:start position:0% +your hands and saying I have no idea why +anything happened. Let's just model it + + align:start position:0% +anything happened. Let's just model it + + + align:start position:0% +anything happened. Let's just model it +as a random process. We say no, let's + + align:start position:0% +as a random process. We say no, let's + + + align:start position:0% +as a random process. We say no, let's +try to see if we can separate those + + align:start position:0% +try to see if we can separate those + + + align:start position:0% +try to see if we can separate those +things that have a clear cause which we + + align:start position:0% +things that have a clear cause which we + + + align:start position:0% +things that have a clear cause which we +may or may not be able to control and + + align:start position:0% +may or may not be able to control and + + + align:start position:0% +may or may not be able to control and +those things that we just don't know + + align:start position:0% +those things that we just don't know + + + align:start position:0% +those things that we just don't know +about. Okay. And then scrambling at the + + align:start position:0% +about. Okay. And then scrambling at the + + + align:start position:0% +about. Okay. And then scrambling at the +end I'll try to get to this concept of + + align:start position:0% +end I'll try to get to this concept of + + + align:start position:0% +end I'll try to get to this concept of +uh states and properties. And this is + + align:start position:0% +uh states and properties. And this is + + + align:start position:0% +uh states and properties. And this is +again this is more of a framework issue + + align:start position:0% +again this is more of a framework issue + + + align:start position:0% +again this is more of a framework issue +but it is uh an issue of looking at any + + align:start position:0% +but it is uh an issue of looking at any + + + align:start position:0% +but it is uh an issue of looking at any +process + + align:start position:0% +process + + + align:start position:0% +process +uh looking at all the different factors + + align:start position:0% +uh looking at all the different factors + + + align:start position:0% +uh looking at all the different factors +that enter into the outcome of the + + align:start position:0% +that enter into the outcome of the + + + align:start position:0% +that enter into the outcome of the +process and just parsing it really uh + + align:start position:0% +process and just parsing it really uh + + + align:start position:0% +process and just parsing it really uh +into four areas and this idea + + align:start position:0% +into four areas and this idea + + + align:start position:0% +into four areas and this idea +of what we'll end up calling + + align:start position:0% +of what we'll end up calling + + + align:start position:0% +of what we'll end up calling +thermodynamic states those things that + + align:start position:0% +thermodynamic states those things that + + + align:start position:0% +thermodynamic states those things that +are kind of transit come and go and + + align:start position:0% +are kind of transit come and go and + + + align:start position:0% +are kind of transit come and go and +properties those things that are + + align:start position:0% +properties those things that are + + + align:start position:0% +properties those things that are +inherent in the process and then we'll + + align:start position:0% +inherent in the process and then we'll + + + align:start position:0% +inherent in the process and then we'll +separate the process into the equipment + + align:start position:0% +separate the process into the equipment + + + align:start position:0% +separate the process into the equipment +that executes the process which kind of + + align:start position:0% +that executes the process which kind of + + + align:start position:0% +that executes the process which kind of +stays there day after day and year after + + align:start position:0% +stays there day after day and year after + + + align:start position:0% +stays there day after day and year after +year and the material that you're uh + + align:start position:0% +year and the material that you're uh + + + align:start position:0% +year and the material that you're uh +changing as part of the process and of + + align:start position:0% +changing as part of the process and of + + + align:start position:0% +changing as part of the process and of +course that changes on every cycle of + + align:start position:0% +course that changes on every cycle of + + + align:start position:0% +course that changes on every cycle of +the process and those that distinction + + align:start position:0% +the process and those that distinction + + + align:start position:0% +the process and those that distinction +between the two is extremely + + align:start position:0% +between the two is extremely + + + align:start position:0% +between the two is extremely +important. So here's the model you've + + align:start position:0% +important. So here's the model you've + + + align:start position:0% +important. So here's the model you've +already seen and um the first part of + + align:start position:0% +already seen and um the first part of + + + align:start position:0% +already seen and um the first part of +this is to notice that uh we've taken + + align:start position:0% +this is to notice that uh we've taken + + + align:start position:0% +this is to notice that uh we've taken +the manufacturing process and said well + + align:start position:0% +the manufacturing process and said well + + + align:start position:0% +the manufacturing process and said well +again uh there are these two elements to + + align:start position:0% +again uh there are these two elements to + + + align:start position:0% +again uh there are these two elements to +it. There's the material + + align:start position:0% +it. There's the material + + + align:start position:0% +it. There's the material +um which is again sort of coming and + + align:start position:0% +um which is again sort of coming and + + + align:start position:0% +um which is again sort of coming and +going and by its very nature the fact + + align:start position:0% +going and by its very nature the fact + + + align:start position:0% +going and by its very nature the fact +that every time you run the process + + align:start position:0% +that every time you run the process + + + align:start position:0% +that every time you run the process +there's a new piece of material in there + + align:start position:0% +there's a new piece of material in there + + + align:start position:0% +there's a new piece of material in there +that's going to have a different + + align:start position:0% +that's going to have a different + + + align:start position:0% +that's going to have a different +characteristic for its variability than + + align:start position:0% +characteristic for its variability than + + + align:start position:0% +characteristic for its variability than +the equipment which again is you know + + align:start position:0% +the equipment which again is you know + + + align:start position:0% +the equipment which again is you know +unless you buy disposable equipment um + + align:start position:0% +unless you buy disposable equipment um + + + align:start position:0% +unless you buy disposable equipment um +you generally keep around for uh years + + align:start position:0% +you generally keep around for uh years + + + align:start position:0% +you generally keep around for uh years +and then there's an interaction between + + align:start position:0% +and then there's an interaction between + + + align:start position:0% +and then there's an interaction between +the two and that interaction + + align:start position:0% +the two and that interaction + + + align:start position:0% +the two and that interaction +uh if you really want to abstract it is + + align:start position:0% +uh if you really want to abstract it is + + + align:start position:0% +uh if you really want to abstract it is +a uh could be called a directed energy + + align:start position:0% +a uh could be called a directed energy + + + align:start position:0% +a uh could be called a directed energy +exchange. It always takes some energy to + + align:start position:0% +exchange. It always takes some energy to + + + align:start position:0% +exchange. It always takes some energy to +cause the material to change. And what + + align:start position:0% +cause the material to change. And what + + + align:start position:0% +cause the material to change. And what +are you trying to change? You're trying + + align:start position:0% +are you trying to change? You're trying + + + align:start position:0% +are you trying to change? You're trying +to change its + + align:start position:0% +to change its + + + align:start position:0% +to change its +geometry. Usually only its geometry. + + align:start position:0% +geometry. Usually only its geometry. + + + align:start position:0% +geometry. Usually only its geometry. +Often properties change as a result of + + align:start position:0% +Often properties change as a result of + + + align:start position:0% +Often properties change as a result of +that. Or sometimes you're changing + + align:start position:0% +that. Or sometimes you're changing + + + align:start position:0% +that. Or sometimes you're changing +properties like a hardening process or + + align:start position:0% +properties like a hardening process or + + + align:start position:0% +properties like a hardening process or +ion implantation something like that. + + align:start position:0% +ion implantation something like that. + + + align:start position:0% +ion implantation something like that. +You're taking one material and through + + align:start position:0% +You're taking one material and through + + + align:start position:0% +You're taking one material and through +this pl pro process transforming it in + + align:start position:0% +this pl pro process transforming it in + + + align:start position:0% +this pl pro process transforming it in +some + + align:start position:0% +some + + + align:start position:0% +some +way. And um again just just to to remind + + align:start position:0% +way. And um again just just to to remind + + + align:start position:0% +way. And um again just just to to remind +you we have this simple functional + + align:start position:0% +you we have this simple functional + + + align:start position:0% +you we have this simple functional +relationship that says well guess what + + align:start position:0% +relationship that says well guess what + + + align:start position:0% +relationship that says well guess what +the output is a function of all the + + align:start position:0% +the output is a function of all the + + + align:start position:0% +the output is a function of all the +inputs. That's really all it's saying + + align:start position:0% +inputs. That's really all it's saying + + + align:start position:0% +inputs. That's really all it's saying +and and defining it right now saying + + align:start position:0% +and and defining it right now saying + + + align:start position:0% +and and defining it right now saying +that the outputs is some are some vector + + align:start position:0% +that the outputs is some are some vector + + + align:start position:0% +that the outputs is some are some vector +or the outputs can be described as a + + align:start position:0% +or the outputs can be described as a + + + align:start position:0% +or the outputs can be described as a +vector which has all of the relevant + + align:start position:0% +vector which has all of the relevant + + + align:start position:0% +vector which has all of the relevant +geometry and property characteristics of + + align:start position:0% +geometry and property characteristics of + + + align:start position:0% +geometry and property characteristics of +the process. So it would be dimensions, + + align:start position:0% +the process. So it would be dimensions, + + + align:start position:0% +the process. So it would be dimensions, +material properties, things like that. + + align:start position:0% +material properties, things like that. + + + align:start position:0% +material properties, things like that. +um and process parameters using a really + + align:start position:0% +um and process parameters using a really + + + align:start position:0% +um and process parameters using a really +generic word for those input variables + + align:start position:0% +generic word for those input variables + + + align:start position:0% +generic word for those input variables +because I'm going to distinguish between + + align:start position:0% +because I'm going to distinguish between + + + align:start position:0% +because I'm going to distinguish between +inputs and uh parameters a little bit + + align:start position:0% +inputs and uh parameters a little bit + + + align:start position:0% +inputs and uh parameters a little bit +later. Uh and just saying that there's + + align:start position:0% +later. Uh and just saying that there's + + + align:start position:0% +later. Uh and just saying that there's +some functional relationship between the + + align:start position:0% +some functional relationship between the + + + align:start position:0% +some functional relationship between the +two and of course here's the functional + + align:start position:0% +two and of course here's the functional + + + align:start position:0% +two and of course here's the functional +relationship all that all that stuff + + align:start position:0% +relationship all that all that stuff + + + align:start position:0% +relationship all that all that stuff +that's in + + align:start position:0% + + + + align:start position:0% + +there. Okay. So + + align:start position:0% +there. Okay. So + + + align:start position:0% +there. Okay. So +um if if we just focus for a moment on + + align:start position:0% +um if if we just focus for a moment on + + + align:start position:0% +um if if we just focus for a moment on +processes where geometry change is the + + align:start position:0% +processes where geometry change is the + + + align:start position:0% +processes where geometry change is the +most uh important one and and I don't + + align:start position:0% +most uh important one and and I don't + + + align:start position:0% +most uh important one and and I don't +know speaking from my perspective on + + align:start position:0% +know speaking from my perspective on + + + align:start position:0% +know speaking from my perspective on +this class that's going to be 100% of + + align:start position:0% +this class that's going to be 100% of + + + align:start position:0% +this class that's going to be 100% of +what I talk about and I think when we + + align:start position:0% +what I talk about and I think when we + + + align:start position:0% +what I talk about and I think when we +get into semiconductors is a little bit + + align:start position:0% +get into semiconductors is a little bit + + + align:start position:0% +get into semiconductors is a little bit +more on on uh material modification but + + align:start position:0% +more on on uh material modification but + + + align:start position:0% +more on on uh material modification but +I think certainly most of the stuff + + align:start position:0% +I think certainly most of the stuff + + + align:start position:0% +I think certainly most of the stuff +you've seen has been on a manufacturing + + align:start position:0% +you've seen has been on a manufacturing + + + align:start position:0% +you've seen has been on a manufacturing +process meaning we change the geometry + + align:start position:0% +process meaning we change the geometry + + + align:start position:0% +process meaning we change the geometry +um you know what causes the output to + + align:start position:0% +um you know what causes the output to + + + align:start position:0% +um you know what causes the output to +change? Well, there's there's a directed + + align:start position:0% +change? Well, there's there's a directed + + + align:start position:0% +change? Well, there's there's a directed +energy exchange with the equipment. + + align:start position:0% +energy exchange with the equipment. + + + align:start position:0% +energy exchange with the equipment. +Okay. And that energy exchange can take + + align:start position:0% +Okay. And that energy exchange can take + + + align:start position:0% +Okay. And that energy exchange can take +the form of any of of the relevant forms + + align:start position:0% +the form of any of of the relevant forms + + + align:start position:0% +the form of any of of the relevant forms +of energy. So, we could have a + + align:start position:0% +of energy. So, we could have a + + + align:start position:0% +of energy. So, we could have a +mechanical exchange where you impose a + + align:start position:0% +mechanical exchange where you impose a + + + align:start position:0% +mechanical exchange where you impose a +force or a displacement on something. We + + align:start position:0% +force or a displacement on something. We + + + align:start position:0% +force or a displacement on something. We +can have an electrical change where you + + align:start position:0% +can have an electrical change where you + + + align:start position:0% +can have an electrical change where you +run a current through something or or uh + + align:start position:0% +run a current through something or or uh + + + align:start position:0% +run a current through something or or uh +have an electric arc something like + + align:start position:0% +have an electric arc something like + + + align:start position:0% +have an electric arc something like +that. It could be thermal and certainly + + align:start position:0% +that. It could be thermal and certainly + + + align:start position:0% +that. It could be thermal and certainly +there are many of processes where uh + + align:start position:0% +there are many of processes where uh + + + align:start position:0% +there are many of processes where uh +transfer of heat is the is the key way + + align:start position:0% +transfer of heat is the is the key way + + + align:start position:0% +transfer of heat is the is the key way +that you change a geometry and certainly + + align:start position:0% +that you change a geometry and certainly + + + align:start position:0% +that you change a geometry and certainly +it could be chemical. Think of an + + align:start position:0% +it could be chemical. Think of an + + + align:start position:0% +it could be chemical. Think of an +etching process or anything like that. + + align:start position:0% +etching process or anything like that. + + + align:start position:0% +etching process or anything like that. +All of these energies directed the + + align:start position:0% +All of these energies directed the + + + align:start position:0% +All of these energies directed the +correct way + + align:start position:0% +correct way + + + align:start position:0% +correct way +uh can be thought of as um uh geometry + + align:start position:0% +uh can be thought of as um uh geometry + + + align:start position:0% +uh can be thought of as um uh geometry +change mechanisms. Now how do we direct + + align:start position:0% +change mechanisms. Now how do we direct + + + align:start position:0% +change mechanisms. Now how do we direct +this energy? + + align:start position:0% +this energy? + + + align:start position:0% +this energy? +You know, if I if I just say say, you + + align:start position:0% +You know, if I if I just say say, you + + + align:start position:0% +You know, if I if I just say say, you +know, I've got I've got some thermal + + align:start position:0% +know, I've got I've got some thermal + + + align:start position:0% +know, I've got I've got some thermal +energy sitting around. You know, how do + + align:start position:0% +energy sitting around. You know, how do + + + align:start position:0% +energy sitting around. You know, how do +I make sure it goes to the right + + align:start position:0% + + + + align:start position:0% + +place? That's the goal. In effect, + + align:start position:0% +place? That's the goal. In effect, + + + align:start position:0% +place? That's the goal. In effect, +that's the goal of the equipment. That's + + align:start position:0% +that's the goal of the equipment. That's + + + align:start position:0% +that's the goal of the equipment. That's +why this one little thing, which which + + align:start position:0% +why this one little thing, which which + + + align:start position:0% +why this one little thing, which which +my thermodynamics friends would go crazy + + align:start position:0% +my thermodynamics friends would go crazy + + + align:start position:0% +my thermodynamics friends would go crazy +with, but but calling energy a vector + + align:start position:0% +with, but but calling energy a vector + + + align:start position:0% +with, but but calling energy a vector +quantity. + + align:start position:0% +quantity. + + + align:start position:0% +quantity. +Um, it matters where you put the energy, + + align:start position:0% +Um, it matters where you put the energy, + + + align:start position:0% +Um, it matters where you put the energy, +right? + + align:start position:0% +right? + + + align:start position:0% +right? +If I want to if I want to take this bar + + align:start position:0% +If I want to if I want to take this bar + + + align:start position:0% +If I want to if I want to take this bar +and maybe do something to the center of + + align:start position:0% +and maybe do something to the center of + + + align:start position:0% +and maybe do something to the center of +it + + align:start position:0% +it + + + align:start position:0% +it +thermally and I've got a thermal energy + + align:start position:0% +thermally and I've got a thermal energy + + + align:start position:0% +thermally and I've got a thermal energy +source out here called a piece of + + align:start position:0% +source out here called a piece of + + + align:start position:0% +source out here called a piece of +equipment, maybe a torch or something + + align:start position:0% +equipment, maybe a torch or something + + + align:start position:0% +equipment, maybe a torch or something +like that. How do I make sure it goes to + + align:start position:0% +like that. How do I make sure it goes to + + + align:start position:0% +like that. How do I make sure it goes to +the right + + align:start position:0% + + + + align:start position:0% + +place? Equipment material. + + align:start position:0% + + + + align:start position:0% + +It's this is one of my easy + + align:start position:0% +It's this is one of my easy + + + align:start position:0% +It's this is one of my easy +questions. I I make sure I hold it in + + align:start position:0% +questions. I I make sure I hold it in + + + align:start position:0% +questions. I I make sure I hold it in +place, right? Yeah. Go ahead. Go ahead, + + align:start position:0% +place, right? Yeah. Go ahead. Go ahead, + + + align:start position:0% +place, right? Yeah. Go ahead. Go ahead, +Z. So I I guess by ways of relative + + align:start position:0% +Z. So I I guess by ways of relative + + + align:start position:0% +Z. So I I guess by ways of relative +positioning, these two are in the + + align:start position:0% +positioning, these two are in the + + + align:start position:0% +positioning, these two are in the +correct positions. Yeah. I mean, if if I + + align:start position:0% +correct positions. Yeah. I mean, if if I + + + align:start position:0% +correct positions. Yeah. I mean, if if I +had like a point source, a laser or or + + align:start position:0% +had like a point source, a laser or or + + + align:start position:0% +had like a point source, a laser or or +an arc or something like that. Laser is + + align:start position:0% +an arc or something like that. Laser is + + + align:start position:0% +an arc or something like that. Laser is +a better example. and I needed to do + + align:start position:0% +a better example. and I needed to do + + + align:start position:0% +a better example. and I needed to do +something right here maybe uh uh + + align:start position:0% +something right here maybe uh uh + + + align:start position:0% +something right here maybe uh uh +thermally deform this or or join it or + + align:start position:0% +thermally deform this or or join it or + + + align:start position:0% +thermally deform this or or join it or +something like that then the key would + + align:start position:0% +something like that then the key would + + + align:start position:0% +something like that then the key would +be how both the value of that energy and + + align:start position:0% +be how both the value of that energy and + + + align:start position:0% +be how both the value of that energy and +uh where I put it. So location would be + + align:start position:0% +uh where I put it. So location would be + + + align:start position:0% +uh where I put it. So location would be +would be uh really important. So that's + + align:start position:0% +would be uh really important. So that's + + + align:start position:0% +would be uh really important. So that's +one way of thinking of the concept of a + + align:start position:0% +one way of thinking of the concept of a + + + align:start position:0% +one way of thinking of the concept of a +directed energy source. If I want to + + align:start position:0% +directed energy source. If I want to + + + align:start position:0% +directed energy source. If I want to +bend this piece of sheet metal, which + + align:start position:0% +bend this piece of sheet metal, which + + + align:start position:0% +bend this piece of sheet metal, which +was originally flat, um, you know, and I + + align:start position:0% +was originally flat, um, you know, and I + + + align:start position:0% +was originally flat, um, you know, and I +have a a displacement device, it's + + align:start position:0% +have a a displacement device, it's + + + align:start position:0% +have a a displacement device, it's +probably probably a good idea for me to + + align:start position:0% +probably probably a good idea for me to + + + align:start position:0% +probably probably a good idea for me to +put that displacement device in the + + align:start position:0% +put that displacement device in the + + + align:start position:0% +put that displacement device in the +middle, not over here, and to have that + + align:start position:0% +middle, not over here, and to have that + + + align:start position:0% +middle, not over here, and to have that +displacement device have a certain shape + + align:start position:0% +displacement device have a certain shape + + + align:start position:0% +displacement device have a certain shape +um, to get what I + + align:start position:0% +um, to get what I + + + align:start position:0% +um, to get what I +want. Think about this one for a second. + + align:start position:0% +want. Think about this one for a second. + + + align:start position:0% +want. Think about this one for a second. +This one, I don't know if you can see + + align:start position:0% +This one, I don't know if you can see + + + align:start position:0% +This one, I don't know if you can see +this. Let me try my document camera. + + align:start position:0% +this. Let me try my document camera. + + + align:start position:0% +this. Let me try my document camera. +Come on, doc. There we + + align:start position:0% +Come on, doc. There we + + + align:start position:0% +Come on, doc. There we +go. Um, this is an injection molded + + align:start position:0% +go. Um, this is an injection molded + + + align:start position:0% +go. Um, this is an injection molded +part. It's from a precision + + align:start position:0% +part. It's from a precision + + + align:start position:0% +part. It's from a precision +yo-yo. And, + + align:start position:0% +yo-yo. And, + + + align:start position:0% +yo-yo. And, +uh, how do I make what's the energy + + align:start position:0% +uh, how do I make what's the energy + + + align:start position:0% +uh, how do I make what's the energy +we're talking about + + align:start position:0% +we're talking about + + + align:start position:0% +we're talking about +there? This was injection molded. I + + align:start position:0% +there? This was injection molded. I + + + align:start position:0% +there? This was injection molded. I +think most of you here have had some + + align:start position:0% +think most of you here have had some + + + align:start position:0% +think most of you here have had some +hands-on experience with injection + + align:start position:0% +hands-on experience with injection + + + align:start position:0% +hands-on experience with injection +molding. If you haven't, I'll haven't, + + align:start position:0% +molding. If you haven't, I'll haven't, + + + align:start position:0% +molding. If you haven't, I'll haven't, +I'll explain it in a few minutes. But + + align:start position:0% +I'll explain it in a few minutes. But + + + align:start position:0% +I'll explain it in a few minutes. But +um where's my directed energy source + + align:start position:0% +um where's my directed energy source + + + align:start position:0% +um where's my directed energy source +there? Or if you're having trouble think + + align:start position:0% +there? Or if you're having trouble think + + + align:start position:0% +there? Or if you're having trouble think +getting your head around that, how did I + + align:start position:0% +getting your head around that, how did I + + + align:start position:0% +getting your head around that, how did I +come up with that shape? + + align:start position:0% + + + + align:start position:0% + +Heat and pressure. Well, I had heat and + + align:start position:0% +Heat and pressure. Well, I had heat and + + + align:start position:0% +Heat and pressure. Well, I had heat and +pressure to to put the liquid plastic in + + align:start position:0% +pressure to to put the liquid plastic in + + + align:start position:0% +pressure to to put the liquid plastic in +there. + + align:start position:0% +there. + + + align:start position:0% +there. +Okay. That kind of filled the mold. But + + align:start position:0% +Okay. That kind of filled the mold. But + + + align:start position:0% +Okay. That kind of filled the mold. But +what determined the shape? Yeah, the + + align:start position:0% +what determined the shape? Yeah, the + + + align:start position:0% +what determined the shape? Yeah, the +mold. And what's the directed energy in + + align:start position:0% +mold. And what's the directed energy in + + + align:start position:0% +mold. And what's the directed energy in +this case? If if if I'm saying the + + align:start position:0% +this case? If if if I'm saying the + + + align:start position:0% +this case? If if if I'm saying the +directed energy leads to the shape of + + align:start position:0% +directed energy leads to the shape of + + + align:start position:0% +directed energy leads to the shape of +the part, you know, the geometry + + align:start position:0% +the part, you know, the geometry + + + align:start position:0% +the part, you know, the geometry +changees, + + align:start position:0% +changees, + + + align:start position:0% +changees, +pardon me, the mill cutting forces from + + align:start position:0% +pardon me, the mill cutting forces from + + + align:start position:0% +pardon me, the mill cutting forces from +whatever bit used to cut the metal. Uh + + align:start position:0% +whatever bit used to cut the metal. Uh + + + align:start position:0% +whatever bit used to cut the metal. Uh +we're talking about plastic molding + + align:start position:0% +we're talking about plastic molding + + + align:start position:0% +we're talking about plastic molding +right now, right? But to make the Oh, to + + align:start position:0% +right now, right? But to make the Oh, to + + + align:start position:0% +right now, right? But to make the Oh, to +make the mold. Um yeah, I see where + + align:start position:0% +make the mold. Um yeah, I see where + + + align:start position:0% +make the mold. Um yeah, I see where +you're going with that. But I'm thinking + + align:start position:0% +you're going with that. But I'm thinking + + + align:start position:0% +you're going with that. But I'm thinking +about just the molding process. The + + align:start position:0% +about just the molding process. The + + + align:start position:0% +about just the molding process. The +tooling the tooling somehow was + + align:start position:0% +tooling the tooling somehow was + + + align:start position:0% +tooling the tooling somehow was +magically there. I think that the energy + + align:start position:0% +magically there. I think that the energy + + + align:start position:0% +magically there. I think that the energy +of the surface. So everywhere where we + + align:start position:0% +of the surface. So everywhere where we + + + align:start position:0% +of the surface. So everywhere where we +have surface we direct energy. Exactly. + + align:start position:0% +have surface we direct energy. Exactly. + + + align:start position:0% +have surface we direct energy. Exactly. +So now the the the one big distinction + + align:start position:0% +So now the the the one big distinction + + + align:start position:0% +So now the the the one big distinction +between these two is that here it was + + align:start position:0% +between these two is that here it was + + + align:start position:0% +between these two is that here it was +pretty clear that I had a um a pretty + + align:start position:0% +pretty clear that I had a um a pretty + + + align:start position:0% +pretty clear that I had a um a pretty +localized uh source of + + align:start position:0% +localized uh source of + + + align:start position:0% +localized uh source of +energy. And of course the case of + + align:start position:0% +energy. And of course the case of + + + align:start position:0% +energy. And of course the case of +heating this would be the same or as + + align:start position:0% +heating this would be the same or as + + + align:start position:0% +heating this would be the same or as +you'll see later turning it with a with + + align:start position:0% +you'll see later turning it with a with + + + align:start position:0% +you'll see later turning it with a with +a with a + + align:start position:0% +a with a + + + align:start position:0% +a with a +a point say a pointed tool. um here + + align:start position:0% +a point say a pointed tool. um here + + + align:start position:0% +a point say a pointed tool. um here +everything's happening everywhere at + + align:start position:0% +everything's happening everywhere at + + + align:start position:0% +everything's happening everywhere at +once and the direction the the if you + + align:start position:0% +once and the direction the the if you + + + align:start position:0% +once and the direction the the if you +will the spatial aspect of it is imbued + + align:start position:0% +will the spatial aspect of it is imbued + + + align:start position:0% +will the spatial aspect of it is imbued +not by how I position something but by + + align:start position:0% +not by how I position something but by + + + align:start position:0% +not by how I position something but by +uh the shape of the tool. So you start + + align:start position:0% +uh the shape of the tool. So you start + + + align:start position:0% +uh the shape of the tool. So you start +to see that there kind of two extremes + + align:start position:0% +to see that there kind of two extremes + + + align:start position:0% +to see that there kind of two extremes +here. There's the case where this + + align:start position:0% +here. There's the case where this + + + align:start position:0% +here. There's the case where this +geometry is determined + + align:start position:0% +geometry is determined + + + align:start position:0% +geometry is determined +primarily by a spatial distribution of + + align:start position:0% +primarily by a spatial distribution of + + + align:start position:0% +primarily by a spatial distribution of +energy exchange which is a little bit + + align:start position:0% +energy exchange which is a little bit + + + align:start position:0% +energy exchange which is a little bit +stretching it a little bit here but a + + align:start position:0% +stretching it a little bit here but a + + + align:start position:0% +stretching it a little bit here but a +shaped tool and as Simon said everything + + align:start position:0% +shaped tool and as Simon said everything + + + align:start position:0% +shaped tool and as Simon said everything +happens everywhere at the same time. + + align:start position:0% +happens everywhere at the same time. + + + align:start position:0% +happens everywhere at the same time. +Okay. Whereas in this case things are + + align:start position:0% +Okay. Whereas in this case things are + + + align:start position:0% +Okay. Whereas in this case things are +thing the things are changing over + + align:start position:0% +thing the things are changing over + + + align:start position:0% +thing the things are changing over +time and uh thing quite different things + + align:start position:0% +time and uh thing quite different things + + + align:start position:0% +time and uh thing quite different things +happening at different places and in + + align:start position:0% +happening at different places and in + + + align:start position:0% +happening at different places and in +more extreme case again which I'll get + + align:start position:0% +more extreme case again which I'll get + + + align:start position:0% +more extreme case again which I'll get +to later is if if I'm coming in here + + align:start position:0% +to later is if if I'm coming in here + + + align:start position:0% +to later is if if I'm coming in here +with some sort of a point source let's + + align:start position:0% +with some sort of a point source let's + + + align:start position:0% +with some sort of a point source let's +say heating it or applying a force here + + align:start position:0% +say heating it or applying a force here + + + align:start position:0% +say heating it or applying a force here +there's nothing happening out here it's + + align:start position:0% +there's nothing happening out here it's + + + align:start position:0% +there's nothing happening out here it's +all happening right here and the net + + align:start position:0% +all happening right here and the net + + + align:start position:0% +all happening right here and the net +shape that I get has a lot more to do + + align:start position:0% +shape that I get has a lot more to do + + + align:start position:0% +shape that I get has a lot more to do +with how I move that interaction + + align:start position:0% +with how I move that interaction + + + align:start position:0% +with how I move that interaction +port, otherwise known as a tool, uh, + + align:start position:0% +port, otherwise known as a tool, uh, + + + align:start position:0% +port, otherwise known as a tool, uh, +than it does with the tool shape. Tool + + align:start position:0% +than it does with the tool shape. Tool + + + align:start position:0% +than it does with the tool shape. Tool +shape is important, but it's of + + align:start position:0% +shape is important, but it's of + + + align:start position:0% +shape is important, but it's of +secondary importance. + + align:start position:0% + + + + align:start position:0% + +Okay. Okay. They're supposed to go away + + align:start position:0% +Okay. Okay. They're supposed to go away + + + align:start position:0% +Okay. Okay. They're supposed to go away +now. There we go. Okay. Well, they + + align:start position:0% +now. There we go. Okay. Well, they + + + align:start position:0% +now. There we go. Okay. Well, they +didn't go away. It's good to see you + + align:start position:0% +didn't go away. It's good to see you + + + align:start position:0% +didn't go away. It's good to see you +guys. Okay. So, um, now we talk about it + + align:start position:0% +guys. Okay. So, um, now we talk about it + + + align:start position:0% +guys. Okay. So, um, now we talk about it +and we say, + + align:start position:0% + + + + align:start position:0% + +um, it's about geometry change, and I've + + align:start position:0% +um, it's about geometry change, and I've + + + align:start position:0% +um, it's about geometry change, and I've +kind of thrown out some some different + + align:start position:0% +kind of thrown out some some different + + + align:start position:0% +kind of thrown out some some different +ones here. How do you change the shape + + align:start position:0% +ones here. How do you change the shape + + + align:start position:0% +ones here. How do you change the shape +of + + align:start position:0% +of + + + align:start position:0% +of +anything? All right. Well, we already + + align:start position:0% +anything? All right. Well, we already + + + align:start position:0% +anything? All right. Well, we already +talked about one. It's pretty obvious. + + align:start position:0% +talked about one. It's pretty obvious. + + + align:start position:0% +talked about one. It's pretty obvious. +Take out a knife and and a piece of wood + + align:start position:0% +Take out a knife and and a piece of wood + + + align:start position:0% +Take out a knife and and a piece of wood +and you can change its shape by removing + + align:start position:0% +and you can change its shape by removing + + + align:start position:0% +and you can change its shape by removing +wood chips. Okay. Whiddling. That's your + + align:start position:0% +wood chips. Okay. Whiddling. That's your + + + align:start position:0% +wood chips. Okay. Whiddling. That's your +basic basic shaping technique. Well, + + align:start position:0% +basic basic shaping technique. Well, + + + align:start position:0% +basic basic shaping technique. Well, +that's that's essentially uh one of the + + align:start position:0% +that's that's essentially uh one of the + + + align:start position:0% +that's that's essentially uh one of the +most common ways of making anything. You + + align:start position:0% +most common ways of making anything. You + + + align:start position:0% +most common ways of making anything. You +know, we etch away uh silicon. U we + + align:start position:0% +know, we etch away uh silicon. U we + + + align:start position:0% +know, we etch away uh silicon. U we +machine away + + align:start position:0% +machine away + + + align:start position:0% +machine away +material. Um we can uh oxidize and burn + + align:start position:0% +material. Um we can uh oxidize and burn + + + align:start position:0% +material. Um we can uh oxidize and burn +things off. We can uh uh do it in a + + align:start position:0% +things off. We can uh uh do it in a + + + align:start position:0% +things off. We can uh uh do it in a +number of different ways. Okay. So, + + align:start position:0% +number of different ways. Okay. So, + + + align:start position:0% +number of different ways. Okay. So, +removal of material is obviously one way + + align:start position:0% +removal of material is obviously one way + + + align:start position:0% +removal of material is obviously one way +of doing things. Okay. Pretty obvious + + align:start position:0% +of doing things. Okay. Pretty obvious + + + align:start position:0% +of doing things. Okay. Pretty obvious +one. How else can I change the shape of + + align:start position:0% +one. How else can I change the shape of + + + align:start position:0% +one. How else can I change the shape of +something? + + align:start position:0% + + + + align:start position:0% + +add material. I can add material to it. + + align:start position:0% +add material. I can add material to it. + + + align:start position:0% +add material. I can add material to it. +Yeah, I can or or join or something like + + align:start position:0% +Yeah, I can or or join or something like + + + align:start position:0% +Yeah, I can or or join or something like +that. So, I can and can reform uh + + align:start position:0% +that. So, I can and can reform uh + + + align:start position:0% +that. So, I can and can reform uh +things. Okay. How else? + + align:start position:0% + + + + align:start position:0% + +I can deform the material like this. + + align:start position:0% +I can deform the material like this. + + + align:start position:0% +I can deform the material like this. +This started out it's it's a fixed piece + + align:start position:0% +This started out it's it's a fixed piece + + + align:start position:0% +This started out it's it's a fixed piece +of material. I didn't add or subtract + + align:start position:0% +of material. I didn't add or subtract + + + align:start position:0% +of material. I didn't add or subtract +anything to it, but I changed the shape + + align:start position:0% +anything to it, but I changed the shape + + + align:start position:0% +anything to it, but I changed the shape +by bending + + align:start position:0% +by bending + + + align:start position:0% +by bending +it. How else? Let me see what I've got + + align:start position:0% +it. How else? Let me see what I've got + + + align:start position:0% +it. How else? Let me see what I've got +here. Okay. plastic deformation of the + + align:start position:0% +here. Okay. plastic deformation of the + + + align:start position:0% +here. Okay. plastic deformation of the +material. So a constant volume, constant + + align:start position:0% +material. So a constant volume, constant + + + align:start position:0% +material. So a constant volume, constant +mass process. The first case you're + + align:start position:0% +mass process. The first case you're + + + align:start position:0% +mass process. The first case you're +throwing material + + align:start position:0% +throwing material + + + align:start position:0% +throwing material +away, adding material, which I think is + + align:start position:0% +away, adding material, which I think is + + + align:start position:0% +away, adding material, which I think is +what people were already talking about. + + align:start position:0% +what people were already talking about. + + + align:start position:0% +what people were already talking about. +And + + align:start position:0% +And + + + align:start position:0% +And +then so uh one one of my famous + + align:start position:0% +then so uh one one of my famous + + + align:start position:0% +then so uh one one of my famous +professors here at MIT called this + + align:start position:0% +professors here at MIT called this + + + align:start position:0% +professors here at MIT called this +machining and negative machining. So + + align:start position:0% +machining and negative machining. So + + + align:start position:0% +machining and negative machining. So +it's kind of another way of thinking of + + align:start position:0% +it's kind of another way of thinking of + + + align:start position:0% +it's kind of another way of thinking of +it, but adding material, subtracting + + align:start position:0% +it, but adding material, subtracting + + + align:start position:0% +it, but adding material, subtracting +material. the the ultimate manufacturing + + align:start position:0% +material. the the ultimate manufacturing + + + align:start position:0% +material. the the ultimate manufacturing +tool would be one that you know took + + align:start position:0% +tool would be one that you know took + + + align:start position:0% +tool would be one that you know took +from here and gave to there and that + + align:start position:0% +from here and gave to there and that + + + align:start position:0% +from here and gave to there and that +sort of thing. Um what else? There's one + + align:start position:0% +sort of thing. Um what else? There's one + + + align:start position:0% +sort of thing. Um what else? There's one +other where does this where does this + + align:start position:0% +other where does this where does this + + + align:start position:0% +other where does this where does this +fit in? It doesn't fit any of those. + + align:start position:0% + + + + align:start position:0% + +Yeah, you guys took 2810, right? So you + + align:start position:0% +Yeah, you guys took 2810, right? So you + + + align:start position:0% +Yeah, you guys took 2810, right? So you +probably already covered this, but yes, + + align:start position:0% +probably already covered this, but yes, + + + align:start position:0% +probably already covered this, but yes, +formation of material. So uh where you + + align:start position:0% +formation of material. So uh where you + + + align:start position:0% +formation of material. So uh where you +uh go from uh a liquid or vapor state, + + align:start position:0% +uh go from uh a liquid or vapor state, + + + align:start position:0% +uh go from uh a liquid or vapor state, +it + + align:start position:0% +it + + + align:start position:0% +it +solidifies against some energy exchange + + align:start position:0% +solidifies against some energy exchange + + + align:start position:0% +solidifies against some energy exchange +medium or form tool and you come up with + + align:start position:0% +medium or form tool and you come up with + + + align:start position:0% +medium or form tool and you come up with +that shape. Okay. What else? That's only + + align:start position:0% + + + + align:start position:0% + +four. This is every manufacturing + + align:start position:0% +four. This is every manufacturing + + + align:start position:0% +four. This is every manufacturing +process in the world in the universe. + + align:start position:0% +process in the world in the universe. + + + align:start position:0% +process in the world in the universe. +Well, it's kind of under addition, but + + align:start position:0% +Well, it's kind of under addition, but + + + align:start position:0% +Well, it's kind of under addition, but +actually growing material + + align:start position:0% +actually growing material + + + align:start position:0% +actually growing material +biological process like a silicon + + align:start position:0% +biological process like a silicon + + + align:start position:0% +biological process like a silicon +crystal. Okay, good. We'll call that + + align:start position:0% +crystal. Okay, good. We'll call that + + + align:start position:0% +crystal. Okay, good. We'll call that +addition. + + align:start position:0% +addition. + + + align:start position:0% +addition. +It ruins my punch line if we + + align:start position:0% +It ruins my punch line if we + + + align:start position:0% +It ruins my punch line if we +don't. Any others? + + align:start position:0% +don't. Any others? + + + align:start position:0% +don't. Any others? +Well, I mean the the the point is that + + align:start position:0% +Well, I mean the the the point is that + + + align:start position:0% +Well, I mean the the the point is that +that + + align:start position:0% +that + + + align:start position:0% +that +um again it's it is a matter of + + align:start position:0% +um again it's it is a matter of + + + align:start position:0% +um again it's it is a matter of +definitions and you could cut this more + + align:start position:0% +definitions and you could cut this more + + + align:start position:0% +definitions and you could cut this more +finely, but this pretty nicely + + align:start position:0% +finely, but this pretty nicely + + + align:start position:0% +finely, but this pretty nicely +characterizes every manufacturing + + align:start position:0% +characterizes every manufacturing + + + align:start position:0% +characterizes every manufacturing +process with respect to geometry change. + + align:start position:0% +process with respect to geometry change. + + + align:start position:0% +process with respect to geometry change. +We could have a parallel set for uh + + align:start position:0% +We could have a parallel set for uh + + + align:start position:0% +We could have a parallel set for uh +property changes, thermodynamic changes + + align:start position:0% +property changes, thermodynamic changes + + + align:start position:0% +property changes, thermodynamic changes +and you know implantation changes, + + align:start position:0% +and you know implantation changes, + + + align:start position:0% +and you know implantation changes, +atomic changes, so forth and so on. But + + align:start position:0% +atomic changes, so forth and so on. But + + + align:start position:0% +atomic changes, so forth and so on. But +uh for this it seems to cover pretty + + align:start position:0% +uh for this it seems to cover pretty + + + align:start position:0% +uh for this it seems to cover pretty +much everything. So if you look at a + + align:start position:0% +much everything. So if you look at a + + + align:start position:0% +much everything. So if you look at a +manufacturing process or you look at + + align:start position:0% +manufacturing process or you look at + + + align:start position:0% +manufacturing process or you look at +something going on in a factory and say + + align:start position:0% +something going on in a factory and say + + + align:start position:0% +something going on in a factory and say +is this a manufacturing process one of + + align:start position:0% +is this a manufacturing process one of + + + align:start position:0% +is this a manufacturing process one of +these things should be going on if it's + + align:start position:0% +these things should be going on if it's + + + align:start position:0% +these things should be going on if it's +a geometry change uh + + align:start position:0% +a geometry change uh + + + align:start position:0% +a geometry change uh +process. So um what controls the + + align:start position:0% +process. So um what controls the + + + align:start position:0% +process. So um what controls the +geometry change as you said lo the the + + align:start position:0% +geometry change as you said lo the the + + + align:start position:0% +geometry change as you said lo the the +local location and intensity of the + + align:start position:0% +local location and intensity of the + + + align:start position:0% +local location and intensity of the +energy exchange. So we already talked + + align:start position:0% +energy exchange. So we already talked + + + align:start position:0% +energy exchange. So we already talked +about this for turning and here's just a + + align:start position:0% +about this for turning and here's just a + + + align:start position:0% +about this for turning and here's just a +schematic of a simple turning. Uh this + + align:start position:0% +schematic of a simple turning. Uh this + + + align:start position:0% +schematic of a simple turning. Uh this +is actually the experiment we used to do + + align:start position:0% +is actually the experiment we used to do + + + align:start position:0% +is actually the experiment we used to do +where you just or you guys actually did + + align:start position:0% +where you just or you guys actually did + + + align:start position:0% +where you just or you guys actually did +it again where you just come in + + align:start position:0% +it again where you just come in + + + align:start position:0% +it again where you just come in +so-called orthogonal turning and you + + align:start position:0% +so-called orthogonal turning and you + + + align:start position:0% +so-called orthogonal turning and you +come in and reduce the diameter of this + + align:start position:0% +come in and reduce the diameter of this + + + align:start position:0% +come in and reduce the diameter of this +stock. Um and you know more formally we + + align:start position:0% +stock. Um and you know more formally we + + + align:start position:0% +stock. Um and you know more formally we +would say this is the location of the + + align:start position:0% +would say this is the location of the + + + align:start position:0% +would say this is the location of the +maximum shear stress. You you take bring + + align:start position:0% +maximum shear stress. You you take bring + + + align:start position:0% +maximum shear stress. You you take bring +in a tool and the the material is + + align:start position:0% +in a tool and the the material is + + + align:start position:0% +in a tool and the the material is +spinning in this case and there's + + align:start position:0% +spinning in this case and there's + + + align:start position:0% +spinning in this case and there's +essentially no stresses on it. Then you + + align:start position:0% +essentially no stresses on it. Then you + + + align:start position:0% +essentially no stresses on it. Then you +come in with a tool and start applying a + + align:start position:0% +come in with a tool and start applying a + + + align:start position:0% +come in with a tool and start applying a +significant force over a very limited + + align:start position:0% +significant force over a very limited + + + align:start position:0% +significant force over a very limited +area in such a way as to create a + + align:start position:0% +area in such a way as to create a + + + align:start position:0% +area in such a way as to create a +critical shear stress and the material + + align:start position:0% +critical shear stress and the material + + + align:start position:0% +critical shear stress and the material +decides to uh + + align:start position:0% +decides to uh + + + align:start position:0% +decides to uh +leave. Okay. And where you so in an + + align:start position:0% +leave. Okay. And where you so in an + + + align:start position:0% +leave. Okay. And where you so in an +abstract sense I can think of machining + + align:start position:0% +abstract sense I can think of machining + + + align:start position:0% +abstract sense I can think of machining +as locating a maximum a very + + align:start position:0% +as locating a maximum a very + + + align:start position:0% +as locating a maximum a very +concentrated maximal shear stress point + + align:start position:0% +concentrated maximal shear stress point + + + align:start position:0% +concentrated maximal shear stress point +at different places in such a way as to + + align:start position:0% +at different places in such a way as to + + + align:start position:0% +at different places in such a way as to +as to at that location make the material + + align:start position:0% +as to at that location make the material + + + align:start position:0% +as to at that location make the material +disassociate with it. + + align:start position:0% + + + + align:start position:0% + +Okay. Yeah. So, we already talked about + + align:start position:0% +Okay. Yeah. So, we already talked about + + + align:start position:0% +Okay. Yeah. So, we already talked about +this one. Heat transfer at the mold + + align:start position:0% +this one. Heat transfer at the mold + + + align:start position:0% +this one. Heat transfer at the mold +surface and injection molding. + + align:start position:0% +surface and injection molding. + + + align:start position:0% +surface and injection molding. +Um, yeah. This is this is Oops. So, uh, + + align:start position:0% +Um, yeah. This is this is Oops. So, uh, + + + align:start position:0% +Um, yeah. This is this is Oops. So, uh, +another extreme of of um interaction to + + align:start position:0% +another extreme of of um interaction to + + + align:start position:0% +another extreme of of um interaction to +give you an idea that there's more than + + align:start position:0% +give you an idea that there's more than + + + align:start position:0% +give you an idea that there's more than +one way to remove material. And + + align:start position:0% +one way to remove material. And + + + align:start position:0% +one way to remove material. And +everybody, certainly anybody with a + + align:start position:0% +everybody, certainly anybody with a + + + align:start position:0% +everybody, certainly anybody with a +mechanical engineering education, any + + align:start position:0% +mechanical engineering education, any + + + align:start position:0% +mechanical engineering education, any +sort of shop or manufacturing experience + + align:start position:0% +sort of shop or manufacturing experience + + + align:start position:0% +sort of shop or manufacturing experience +says, "Oh, yeah, machining." That's it. + + align:start position:0% +says, "Oh, yeah, machining." That's it. + + + align:start position:0% +says, "Oh, yeah, machining." That's it. +And that's how you remove material. But + + align:start position:0% +And that's how you remove material. But + + + align:start position:0% +And that's how you remove material. But +of course, uh, we remove material in a + + align:start position:0% +of course, uh, we remove material in a + + + align:start position:0% +of course, uh, we remove material in a +lot of different ways. And of course, + + align:start position:0% +lot of different ways. And of course, + + + align:start position:0% +lot of different ways. And of course, +anybody from a doubly or semiconductor + + align:start position:0% +anybody from a doubly or semiconductor + + + align:start position:0% +anybody from a doubly or semiconductor +background says, "Oh yeah, removal, + + align:start position:0% +background says, "Oh yeah, removal, + + + align:start position:0% +background says, "Oh yeah, removal, +that's chemical etching or something + + align:start position:0% +that's chemical etching or something + + + align:start position:0% +that's chemical etching or something +like that." Um, and that's true also. + + align:start position:0% +like that." Um, and that's true also. + + + align:start position:0% +like that." Um, and that's true also. +But, uh, then you have many things these + + align:start position:0% +But, uh, then you have many things these + + + align:start position:0% +But, uh, then you have many things these +beam type processes which are, uh, very + + align:start position:0% +beam type processes which are, uh, very + + + align:start position:0% +beam type processes which are, uh, very +important for a lot of different + + align:start position:0% +important for a lot of different + + + align:start position:0% +important for a lot of different +processes. But you know, think of the + + align:start position:0% +processes. But you know, think of the + + + align:start position:0% +processes. But you know, think of the +the extreme case of a process where + + align:start position:0% +the extreme case of a process where + + + align:start position:0% +the extreme case of a process where +things are very localized and you're + + align:start position:0% +things are very localized and you're + + + align:start position:0% +things are very localized and you're +just doing some something + + align:start position:0% +just doing some something + + + align:start position:0% +just doing some something +uh in a very small region and then you + + align:start position:0% +uh in a very small region and then you + + + align:start position:0% +uh in a very small region and then you +move that region around. The part might + + align:start position:0% +move that region around. The part might + + + align:start position:0% +move that region around. The part might +be something like laser uh processing + + align:start position:0% +be something like laser uh processing + + + align:start position:0% +be something like laser uh processing +laser beams using a laser beam to cut + + align:start position:0% +laser beams using a laser beam to cut + + + align:start position:0% +laser beams using a laser beam to cut +and moving it. This this is uh meant to + + align:start position:0% +and moving it. This this is uh meant to + + + align:start position:0% +and moving it. This this is uh meant to +be a a picture of a robot moving it + + align:start position:0% +be a a picture of a robot moving it + + + align:start position:0% +be a a picture of a robot moving it +around. So the robot is very important + + align:start position:0% +around. So the robot is very important + + + align:start position:0% +around. So the robot is very important +in this case because it's providing the + + align:start position:0% +in this case because it's providing the + + + align:start position:0% +in this case because it's providing the +motion + + align:start position:0% +motion + + + align:start position:0% +motion +um and moving the uh the laser tool. And + + align:start position:0% +um and moving the uh the laser tool. And + + + align:start position:0% +um and moving the uh the laser tool. And +of course this has been taken to extreme + + align:start position:0% +of course this has been taken to extreme + + + align:start position:0% +of course this has been taken to extreme +with um these phentoc lasers which can + + align:start position:0% +with um these phentoc lasers which can + + + align:start position:0% +with um these phentoc lasers which can +affect uh at at any given instant will + + align:start position:0% +affect uh at at any given instant will + + + align:start position:0% +affect uh at at any given instant will +only ablate material in I don't know + + align:start position:0% +only ablate material in I don't know + + + align:start position:0% +only ablate material in I don't know +what submicron areas. So you can you can + + align:start position:0% +what submicron areas. So you can you can + + + align:start position:0% +what submicron areas. So you can you can +really localize it if you want + + align:start position:0% +really localize it if you want + + + align:start position:0% +really localize it if you want +to. And then um you know you've got + + align:start position:0% +to. And then um you know you've got + + + align:start position:0% +to. And then um you know you've got +you've got other things like this like a + + align:start position:0% +you've got other things like this like a + + + align:start position:0% +you've got other things like this like a +CVD process where what you're actually + + align:start position:0% +CVD process where what you're actually + + + align:start position:0% +CVD process where what you're actually +doing is locating uh a chemical reaction + + align:start position:0% +doing is locating uh a chemical reaction + + + align:start position:0% +doing is locating uh a chemical reaction +across the entire surface of something. + + align:start position:0% +across the entire surface of something. + + + align:start position:0% +across the entire surface of something. +And again that's that's that location is + + align:start position:0% +And again that's that's that location is + + + align:start position:0% +And again that's that's that location is +determined primarily by what whatever + + align:start position:0% +determined primarily by what whatever + + + align:start position:0% +determined primarily by what whatever +substrate it is you're trying to coat. + + align:start position:0% +substrate it is you're trying to coat. + + + align:start position:0% +substrate it is you're trying to coat. +In this case we're trying trying to + + align:start position:0% +In this case we're trying trying to + + + align:start position:0% +In this case we're trying trying to +coat. + + align:start position:0% +coat. + + + align:start position:0% +coat. +Um, but just to throw this out, if I + + align:start position:0% +Um, but just to throw this out, if I + + + align:start position:0% +Um, but just to throw this out, if I +have, you know, a nice clean uniform + + align:start position:0% +have, you know, a nice clean uniform + + + align:start position:0% +have, you know, a nice clean uniform +substrate, even with, well, let's just + + align:start position:0% +substrate, even with, well, let's just + + + align:start position:0% +substrate, even with, well, let's just +take a flat one, just a flat disc, and I + + align:start position:0% +take a flat one, just a flat disc, and I + + + align:start position:0% +take a flat one, just a flat disc, and I +need to coat it with a chemical vapor + + align:start position:0% +need to coat it with a chemical vapor + + + align:start position:0% +need to coat it with a chemical vapor +deposition process. So, I've got this + + align:start position:0% +deposition process. So, I've got this + + + align:start position:0% +deposition process. So, I've got this +vapor, and it's going to deposit and um, + + align:start position:0% +vapor, and it's going to deposit and um, + + + align:start position:0% +vapor, and it's going to deposit and um, +solidify on the surface. Um, what's + + align:start position:0% +solidify on the surface. Um, what's + + + align:start position:0% +solidify on the surface. Um, what's +going to determine the final geometry of + + align:start position:0% +going to determine the final geometry of + + + align:start position:0% +going to determine the final geometry of +that surface, of that coating of the + + align:start position:0% +that surface, of that coating of the + + + align:start position:0% +that surface, of that coating of the +surface? + + align:start position:0% + + + + align:start position:0% + +Well, let's Yeah. Well, let's let's + + align:start position:0% +Well, let's Yeah. Well, let's let's + + + align:start position:0% +Well, let's Yeah. Well, let's let's +assume this is just sort of this + + align:start position:0% +assume this is just sort of this + + + align:start position:0% +assume this is just sort of this +chamber filled with with vapor and then + + align:start position:0% +chamber filled with with vapor and then + + + align:start position:0% +chamber filled with with vapor and then +you introduce this in there. + + align:start position:0% +you introduce this in there. + + + align:start position:0% +you introduce this in there. +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +Time certainly is a big big part of it. + + align:start position:0% +Time certainly is a big big part of it. + + + align:start position:0% +Time certainly is a big big part of it. +Yeah. + + align:start position:0% +Yeah. + + + align:start position:0% +Yeah. +topology + + align:start position:0% + + + + align:start position:0% + +the topology of the of the of the + + align:start position:0% +the topology of the of the of the + + + align:start position:0% +the topology of the of the of the +substrate and and I'll just throw in the + + align:start position:0% +substrate and and I'll just throw in the + + + align:start position:0% +substrate and and I'll just throw in the +other is that and because I I want to + + align:start position:0% +other is that and because I I want to + + + align:start position:0% +other is that and because I I want to +make the point that with any of these + + align:start position:0% +make the point that with any of these + + + align:start position:0% +make the point that with any of these +these processes that + + align:start position:0% +these processes that + + + align:start position:0% +these processes that +occur with a distribution sort of + + align:start position:0% +occur with a distribution sort of + + + align:start position:0% +occur with a distribution sort of +simultaneously the ones that Simon was + + align:start position:0% +simultaneously the ones that Simon was + + + align:start position:0% +simultaneously the ones that Simon was +talking about earlier + + align:start position:0% +talking about earlier + + + align:start position:0% +talking about earlier +um there there's always this uh concern + + align:start position:0% +um there there's always this uh concern + + + align:start position:0% +um there there's always this uh concern +that you don't have uniform spatial + + align:start position:0% +that you don't have uniform spatial + + + align:start position:0% +that you don't have uniform spatial +distribution so what I was getting at is + + align:start position:0% +distribution so what I was getting at is + + + align:start position:0% +distribution so what I was getting at is +there was no intention of having + + align:start position:0% +there was no intention of having + + + align:start position:0% +there was no intention of having +directed vapor um density or anything + + align:start position:0% +directed vapor um density or anything + + + align:start position:0% +directed vapor um density or anything +like that. The idea is I've got this + + align:start position:0% +like that. The idea is I've got this + + + align:start position:0% +like that. The idea is I've got this +uniform cloud of uh + + align:start position:0% +uniform cloud of uh + + + align:start position:0% +uniform cloud of uh +vapor and it's reacting with the + + align:start position:0% +vapor and it's reacting with the + + + align:start position:0% +vapor and it's reacting with the +surface. So why might it + + align:start position:0% +surface. So why might it + + + align:start position:0% +surface. So why might it +vary spatially? Not it's certainly going + + align:start position:0% +vary spatially? Not it's certainly going + + + align:start position:0% +vary spatially? Not it's certainly going +to vary over time because it takes time + + align:start position:0% +to vary over time because it takes time + + + align:start position:0% +to vary over time because it takes time +for this stuff to solidify. But it's + + align:start position:0% +for this stuff to solidify. But it's + + + align:start position:0% +for this stuff to solidify. But it's +also going to vary spatially because who + + align:start position:0% +also going to vary spatially because who + + + align:start position:0% +also going to vary spatially because who +said it's uniform? Okay. And one of the + + align:start position:0% +said it's uniform? Okay. And one of the + + + align:start position:0% +said it's uniform? Okay. And one of the +things you want to think about when + + align:start position:0% +things you want to think about when + + + align:start position:0% +things you want to think about when +we're talking about manufacturing is + + align:start position:0% +we're talking about manufacturing is + + + align:start position:0% +we're talking about manufacturing is +always sort of question any any + + align:start position:0% +always sort of question any any + + + align:start position:0% +always sort of question any any +statement of uh uh uniformity or + + align:start position:0% +statement of uh uh uniformity or + + + align:start position:0% +statement of uh uh uniformity or +constancy or things like that because um + + align:start position:0% +constancy or things like that because um + + + align:start position:0% +constancy or things like that because um +uh in inevitably there will be + + align:start position:0% +uh in inevitably there will be + + + align:start position:0% +uh in inevitably there will be +variations because the the topography of + + align:start position:0% +variations because the the topography of + + + align:start position:0% +variations because the the topography of +the of the uh substrate might change. uh + + align:start position:0% +the of the uh substrate might change. uh + + + align:start position:0% +the of the uh substrate might change. uh +who knows and in fact it does happen + + align:start position:0% +who knows and in fact it does happen + + + align:start position:0% +who knows and in fact it does happen +especi especially as you go to larger + + align:start position:0% +especi especially as you go to larger + + + align:start position:0% +especi especially as you go to larger +and larger wafers you get important + + align:start position:0% +and larger wafers you get important + + + align:start position:0% +and larger wafers you get important +variations in the chamber temperature + + align:start position:0% +variations in the chamber temperature + + + align:start position:0% +variations in the chamber temperature +variations you could get concentration + + align:start position:0% +variations you could get concentration + + + align:start position:0% +variations you could get concentration +variations all these kinds of things can + + align:start position:0% +variations all these kinds of things can + + + align:start position:0% +variations all these kinds of things can +uh cause + + align:start position:0% +uh cause + + + align:start position:0% +uh cause +problems + + align:start position:0% +problems + + + align:start position:0% +problems +um one other that I'll mention because I + + align:start position:0% +um one other that I'll mention because I + + + align:start position:0% +um one other that I'll mention because I +I showed this this piece of sheet metal + + align:start position:0% +I showed this this piece of sheet metal + + + align:start position:0% +I showed this this piece of sheet metal +and talked about it as a concentrated + + align:start position:0% +and talked about it as a concentrated + + + align:start position:0% +and talked about it as a concentrated +u energy exchange here's another example + + align:start position:0% +u energy exchange here's another example + + + align:start position:0% +u energy exchange here's another example +of a non-conentrated energy exchange + + align:start position:0% +of a non-conentrated energy exchange + + + align:start position:0% +of a non-conentrated energy exchange +This is a large piece of sheet metal. + + align:start position:0% +This is a large piece of sheet metal. + + + align:start position:0% +This is a large piece of sheet metal. +This dimension here is about 6 feet uh + + align:start position:0% +This dimension here is about 6 feet uh + + + align:start position:0% +This dimension here is about 6 feet uh +aerospace manufacturing and uh it's + + align:start position:0% +aerospace manufacturing and uh it's + + + align:start position:0% +aerospace manufacturing and uh it's +being pulled across this tool and + + align:start position:0% +being pulled across this tool and + + + align:start position:0% +being pulled across this tool and +deformed into here. I actually have a a + + align:start position:0% +deformed into here. I actually have a a + + + align:start position:0% +deformed into here. I actually have a a +sort of video of this which I couldn't + + align:start position:0% +sort of video of this which I couldn't + + + align:start position:0% +sort of video of this which I couldn't +find but you can see it being pulled + + align:start position:0% +find but you can see it being pulled + + + align:start position:0% +find but you can see it being pulled +down to the tool and because of the + + align:start position:0% +down to the tool and because of the + + + align:start position:0% +down to the tool and because of the +reflections of the light you can see + + align:start position:0% +reflections of the light you can see + + + align:start position:0% +reflections of the light you can see +that there's not a single portion of + + align:start position:0% +that there's not a single portion of + + + align:start position:0% +that there's not a single portion of +this p piece large piece of metal that + + align:start position:0% +this p piece large piece of metal that + + + align:start position:0% +this p piece large piece of metal that +isn't being changed at any instant in + + align:start position:0% +isn't being changed at any instant in + + + align:start position:0% +isn't being changed at any instant in +time. So clearly this is this is + + align:start position:0% +time. So clearly this is this is + + + align:start position:0% +time. So clearly this is this is +everything happening everywhere all at + + align:start position:0% +everything happening everywhere all at + + + align:start position:0% +everything happening everywhere all at +once. Uh and we're in effect we're + + align:start position:0% +once. Uh and we're in effect we're + + + align:start position:0% +once. Uh and we're in effect we're +pulling it across a a shaped tool. So in + + align:start position:0% +pulling it across a a shaped tool. So in + + + align:start position:0% +pulling it across a a shaped tool. So in +the end we're we're imposing this + + align:start position:0% +the end we're we're imposing this + + + align:start position:0% +the end we're we're imposing this +displacement field on + + align:start position:0% +displacement field on + + + align:start position:0% +displacement field on +it. Okay. So this gets us to this + + align:start position:0% +it. Okay. So this gets us to this + + + align:start position:0% +it. Okay. So this gets us to this +concept of the + + align:start position:0% +concept of the + + + align:start position:0% +concept of the +taxonomy. You can see that that you know + + align:start position:0% +taxonomy. You can see that that you know + + + align:start position:0% +taxonomy. You can see that that you know +been kind of ranging widely over a + + align:start position:0% +been kind of ranging widely over a + + + align:start position:0% +been kind of ranging widely over a +number of different processes either uh + + align:start position:0% +number of different processes either uh + + + align:start position:0% +number of different processes either uh +directly or by implication. + + align:start position:0% +directly or by implication. + + + align:start position:0% +directly or by implication. +uh and we want to kind of draw some + + align:start position:0% +uh and we want to kind of draw some + + + align:start position:0% +uh and we want to kind of draw some +conclusions from this. So the first is + + align:start position:0% +conclusions from this. So the first is + + + align:start position:0% +conclusions from this. So the first is +that there are two extremes to these + + align:start position:0% +that there are two extremes to these + + + align:start position:0% +that there are two extremes to these +interactions. + + align:start position:0% +interactions. + + + align:start position:0% +interactions. +the so-called serial interaction and you + + align:start position:0% +the so-called serial interaction and you + + + align:start position:0% +the so-called serial interaction and you +know schematically here it's best + + align:start position:0% +know schematically here it's best + + + align:start position:0% +know schematically here it's best +described as you know my phentoc + + align:start position:0% +described as you know my phentoc + + + align:start position:0% +described as you know my phentoc +laser a infantessimally small area of + + align:start position:0% +laser a infantessimally small area of + + + align:start position:0% +laser a infantessimally small area of +interaction over the over the large area + + align:start position:0% +interaction over the over the large area + + + align:start position:0% +interaction over the over the large area +so that at any instant I'm only + + align:start position:0% +so that at any instant I'm only + + + align:start position:0% +so that at any instant I'm only +affecting a small part of the material + + align:start position:0% +affecting a small part of the material + + + align:start position:0% +affecting a small part of the material +but then I I move it I have a time + + align:start position:0% +but then I I move it I have a time + + + align:start position:0% +but then I I move it I have a time +history of this and that's what + + align:start position:0% +history of this and that's what + + + align:start position:0% +history of this and that's what +determines the geometry now of course in + + align:start position:0% +determines the geometry now of course in + + + align:start position:0% +determines the geometry now of course in +a real process even with the phentoc + + align:start position:0% +a real process even with the phentoc + + + align:start position:0% +a real process even with the phentoc +laser if get to small enough um there + + align:start position:0% +laser if get to small enough um there + + + align:start position:0% +laser if get to small enough um there +are spatially distributed effects and as + + align:start position:0% +are spatially distributed effects and as + + + align:start position:0% +are spatially distributed effects and as +I go to larger and larger tools uh this + + align:start position:0% +I go to larger and larger tools uh this + + + align:start position:0% +I go to larger and larger tools uh this +gets uh worse and + + align:start position:0% +gets uh worse and + + + align:start position:0% +gets uh worse and +worse. But if we make a definition that + + align:start position:0% +worse. But if we make a definition that + + + align:start position:0% +worse. But if we make a definition that +the area of the interaction of the + + align:start position:0% +the area of the interaction of the + + + align:start position:0% +the area of the interaction of the +energy interaction is small compared to + + align:start position:0% +energy interaction is small compared to + + + align:start position:0% +energy interaction is small compared to +the total area that I want to + + align:start position:0% +the total area that I want to + + + align:start position:0% +the total area that I want to +change then it's clearly what we'll call + + align:start position:0% +change then it's clearly what we'll call + + + align:start position:0% +change then it's clearly what we'll call +a serial process. + + align:start position:0% +a serial process. + + + align:start position:0% +a serial process. +Um, if the opposite is true, if the area + + align:start position:0% +Um, if the opposite is true, if the area + + + align:start position:0% +Um, if the opposite is true, if the area +of that interaction is on the order of + + align:start position:0% +of that interaction is on the order of + + + align:start position:0% +of that interaction is on the order of +the total area that I'm trying to + + align:start position:0% +the total area that I'm trying to + + + align:start position:0% +the total area that I'm trying to +change, and again, the icon for that + + align:start position:0% +change, and again, the icon for that + + + align:start position:0% +change, and again, the icon for that +would be a, you know, stamping out a car + + align:start position:0% +would be a, you know, stamping out a car + + + align:start position:0% +would be a, you know, stamping out a car +hood or something like that. The area of + + align:start position:0% +hood or something like that. The area of + + + align:start position:0% +hood or something like that. The area of +interaction is the same as the uh area + + align:start position:0% +interaction is the same as the uh area + + + align:start position:0% +interaction is the same as the uh area +that I'm trying to change. Same with + + align:start position:0% +that I'm trying to change. Same with + + + align:start position:0% +that I'm trying to change. Same with +this part. The area of interaction is + + align:start position:0% +this part. The area of interaction is + + + align:start position:0% +this part. The area of interaction is +the entire area. Then we have uh a + + align:start position:0% +the entire area. Then we have uh a + + + align:start position:0% +the entire area. Then we have uh a +parallel process. + + align:start position:0% +parallel process. + + + align:start position:0% +parallel process. +we run into a couple interesting uh + + align:start position:0% +we run into a couple interesting uh + + + align:start position:0% +we run into a couple interesting uh +variants on that. + + align:start position:0% +variants on that. + + + align:start position:0% +variants on that. +Um if we + + align:start position:0% +Um if we + + + align:start position:0% +Um if we +take a very common + + align:start position:0% +take a very common + + + align:start position:0% +take a very common +process rolling to get you know to get + + align:start position:0% +process rolling to get you know to get + + + align:start position:0% +process rolling to get you know to get +um to create sheet or just plate uh + + align:start position:0% +um to create sheet or just plate uh + + + align:start position:0% +um to create sheet or just plate uh +reductions you know I'm coming in with + + align:start position:0% +reductions you know I'm coming in with + + + align:start position:0% +reductions you know I'm coming in with +material that looks like this. I'm + + align:start position:0% +material that looks like this. I'm + + + align:start position:0% +material that looks like this. I'm +coming out with a material that's much + + align:start position:0% +coming out with a material that's much + + + align:start position:0% +coming out with a material that's much +thinner. + + align:start position:0% + + + + align:start position:0% + +Um, where does this fit in this taxonomy + + align:start position:0% +Um, where does this fit in this taxonomy + + + align:start position:0% +Um, where does this fit in this taxonomy +here? This part of the taxonomy, is it a + + align:start position:0% +here? This part of the taxonomy, is it a + + + align:start position:0% +here? This part of the taxonomy, is it a +serial process or a a parallel process? + + align:start position:0% + + + + align:start position:0% + +Serial. + + align:start position:0% + + + + align:start position:0% + +Okay. Okay. So we have 50% of the + + align:start position:0% +Okay. Okay. So we have 50% of the + + + align:start position:0% +Okay. Okay. So we have 50% of the +electorate going for serial. This might + + align:start position:0% +electorate going for serial. This might + + + align:start position:0% +electorate going for serial. This might +be Democratic uh primary parallel 50% + + align:start position:0% +be Democratic uh primary parallel 50% + + + align:start position:0% +be Democratic uh primary parallel 50% +saying parallel. Guess it goes to the + + align:start position:0% + + + + align:start position:0% + +superdelegates. Okay. You guys you guys + + align:start position:0% +superdelegates. Okay. You guys you guys + + + align:start position:0% +superdelegates. Okay. You guys you guys +in Singapore and to you guys want to you + + align:start position:0% +in Singapore and to you guys want to you + + + align:start position:0% +in Singapore and to you guys want to you +want to break the tie here? What is it? + + align:start position:0% +want to break the tie here? What is it? + + + align:start position:0% +want to break the tie here? What is it? +Serial or parallel? + + align:start position:0% +Serial or parallel? + + + align:start position:0% +Serial or parallel? +I think it's parallel. Okay. So 51% for + + align:start position:0% +I think it's parallel. Okay. So 51% for + + + align:start position:0% +I think it's parallel. Okay. So 51% for +uh parallel. Anybody? Anybody there say + + align:start position:0% + + + + align:start position:0% + +serial? We have some Yeah, we still we + + align:start position:0% +serial? We have some Yeah, we still we + + + align:start position:0% +serial? We have some Yeah, we still we +got some cereals here. + + align:start position:0% + + + + align:start position:0% + +H Yeah, now we're getting to it. Okay, + + align:start position:0% +H Yeah, now we're getting to it. Okay, + + + align:start position:0% +H Yeah, now we're getting to it. Okay, +it depends. If I had drawn this in + + align:start position:0% +it depends. If I had drawn this in + + + align:start position:0% +it depends. If I had drawn this in +2D like + + align:start position:0% +2D like + + + align:start position:0% +2D like +this and maybe maybe sort of drawn it in + + align:start position:0% +this and maybe maybe sort of drawn it in + + + align:start position:0% +this and maybe maybe sort of drawn it in +extreme and didn't even show this + + align:start position:0% +extreme and didn't even show this + + + align:start position:0% +extreme and didn't even show this +necking just kind of showed it doing + + align:start position:0% +necking just kind of showed it doing + + + align:start position:0% +necking just kind of showed it doing +this then you'd you'd be pretty tempted + + align:start position:0% +this then you'd you'd be pretty tempted + + + align:start position:0% +this then you'd you'd be pretty tempted +to say oh that's a serial process + + align:start position:0% +to say oh that's a serial process + + + align:start position:0% +to say oh that's a serial process +because all the action is right here. + + align:start position:0% +because all the action is right here. + + + align:start position:0% +because all the action is right here. +Look at this huge area that I'm + + align:start position:0% +Look at this huge area that I'm + + + align:start position:0% +Look at this huge area that I'm +affecting and all the action is right + + align:start position:0% +affecting and all the action is right + + + align:start position:0% +affecting and all the action is right +there. If I draw it in in in uh uh front + + align:start position:0% +there. If I draw it in in in uh uh front + + + align:start position:0% +there. If I draw it in in in uh uh front +end + + align:start position:0% + + + + align:start position:0% + +view and I here's the + + align:start position:0% + + + + align:start position:0% + +material, you'd look at that say, "Oh, + + align:start position:0% +material, you'd look at that say, "Oh, + + + align:start position:0% +material, you'd look at that say, "Oh, +that's parallel. Everything's happening + + align:start position:0% +that's parallel. Everything's happening + + + align:start position:0% +that's parallel. Everything's happening +everywhere at the same time." Okay, so + + align:start position:0% +everywhere at the same time." Okay, so + + + align:start position:0% +everywhere at the same time." Okay, so +just a cautionary tale. It's it's it's + + align:start position:0% +just a cautionary tale. It's it's it's + + + align:start position:0% +just a cautionary tale. It's it's it's +it's not either or, it's neither nor. + + align:start position:0% +it's not either or, it's neither nor. + + + align:start position:0% +it's not either or, it's neither nor. +Okay. uh uh it's it's sort of + + align:start position:0% +Okay. uh uh it's it's sort of + + + align:start position:0% +Okay. uh uh it's it's sort of +prepundonderance of if you will. So + + align:start position:0% +prepundonderance of if you will. So + + + align:start position:0% +prepundonderance of if you will. So +um this this is a good example of of why + + align:start position:0% +um this this is a good example of of why + + + align:start position:0% +um this this is a good example of of why +they're actually important even though + + align:start position:0% +they're actually important even though + + + align:start position:0% +they're actually important even though +it's mixed on here. And I'm going to + + align:start position:0% +it's mixed on here. And I'm going to + + + align:start position:0% +it's mixed on here. And I'm going to +jump ahead to the sort of who cares, + + align:start position:0% +jump ahead to the sort of who cares, + + + align:start position:0% +jump ahead to the sort of who cares, +which may not have a satisfactory answer + + align:start position:0% +which may not have a satisfactory answer + + + align:start position:0% +which may not have a satisfactory answer +today, but the who cares is um if I'm + + align:start position:0% +today, but the who cares is um if I'm + + + align:start position:0% +today, but the who cares is um if I'm +running in this case the Alcoa, + + align:start position:0% +running in this case the Alcoa, + + + align:start position:0% +running in this case the Alcoa, +Tennessee, that's a that's a real town. + + align:start position:0% +Tennessee, that's a that's a real town. + + + align:start position:0% +Tennessee, that's a that's a real town. +The Alcoa, + + align:start position:0% +The Alcoa, + + + align:start position:0% +The Alcoa, +Tennessee cold rolling mill that makes + + align:start position:0% +Tennessee cold rolling mill that makes + + + align:start position:0% +Tennessee cold rolling mill that makes +all their beer can stock. Um, and I'm + + align:start position:0% +all their beer can stock. Um, and I'm + + + align:start position:0% +all their beer can stock. Um, and I'm +really concerned about extremely good + + align:start position:0% +really concerned about extremely good + + + align:start position:0% +really concerned about extremely good +thickness control because when it goes + + align:start position:0% +thickness control because when it goes + + + align:start position:0% +thickness control because when it goes +into the high-speed canning machines, + + align:start position:0% +into the high-speed canning machines, + + + align:start position:0% +into the high-speed canning machines, +that thickness has to be right on, + + align:start position:0% +that thickness has to be right on, + + + align:start position:0% +that thickness has to be right on, +otherwise the walls will tear or it + + align:start position:0% +otherwise the walls will tear or it + + + align:start position:0% +otherwise the walls will tear or it +won't form + + align:start position:0% +won't form + + + align:start position:0% +won't form +properly. What do I control? Just + + align:start position:0% +properly. What do I control? Just + + + align:start position:0% +properly. What do I control? Just +intuitively, what would I control to + + align:start position:0% +intuitively, what would I control to + + + align:start position:0% +intuitively, what would I control to +affect the + + align:start position:0% +affect the + + + align:start position:0% +affect the +geometry parameter called thickness? + + align:start position:0% + + + + align:start position:0% + +Distance between the rolls. Yeah. Okay. + + align:start position:0% +Distance between the rolls. Yeah. Okay. + + + align:start position:0% +Distance between the rolls. Yeah. Okay. +So I control the thickness by + + align:start position:0% +So I control the thickness by + + + align:start position:0% +So I control the thickness by +controlling let's say this this this + + align:start position:0% +controlling let's say this this this + + + align:start position:0% +controlling let's say this this this +distance right + + align:start position:0% +distance right + + + align:start position:0% +distance right +here, + + align:start position:0% +here, + + + align:start position:0% +here, +right? Which thickness does that + + align:start position:0% +right? Which thickness does that + + + align:start position:0% +right? Which thickness does that +control? Does it control this thickness + + align:start position:0% +control? Does it control this thickness + + + align:start position:0% +control? Does it control this thickness +right here or this one here or that one + + align:start position:0% +right here or this one here or that one + + + align:start position:0% +right here or this one here or that one +there? Or maybe that one there or that + + align:start position:0% +there? Or maybe that one there or that + + + align:start position:0% +there? Or maybe that one there or that +one + + align:start position:0% + + + + align:start position:0% + +there? All you can Yeah. All you're + + align:start position:0% +there? All you can Yeah. All you're + + + align:start position:0% +there? All you can Yeah. All you're +doing there's one display there's one + + align:start position:0% +doing there's one display there's one + + + align:start position:0% +doing there's one display there's one +spacing there. You all right? Right. And + + align:start position:0% +spacing there. You all right? Right. And + + + align:start position:0% +spacing there. You all right? Right. And +if I if you say, "Oh, yeah. It's exactly + + align:start position:0% +if I if you say, "Oh, yeah. It's exactly + + + align:start position:0% +if I if you say, "Oh, yeah. It's exactly +right here." And then I I make little + + align:start position:0% +right here." And then I I make little + + + align:start position:0% +right here." And then I I make little +discs and make my cans for the material + + align:start position:0% +discs and make my cans for the material + + + align:start position:0% +discs and make my cans for the material +over here. Who's to say it's going to be + + align:start position:0% +over here. Who's to say it's going to be + + + align:start position:0% +over here. Who's to say it's going to be +right? So even in this case, I've + + align:start position:0% +right? So even in this case, I've + + + align:start position:0% +right? So even in this case, I've +actually got a mixed problem here and a + + align:start position:0% +actually got a mixed problem here and a + + + align:start position:0% +actually got a mixed problem here and a +mixed control problem. So yeah, here's a + + align:start position:0% +mixed control problem. So yeah, here's a + + + align:start position:0% +mixed control problem. So yeah, here's a +case where displacement, you know, this + + align:start position:0% +case where displacement, you know, this + + + align:start position:0% +case where displacement, you know, this +trajectory we're talking about, just + + align:start position:0% +trajectory we're talking about, just + + + align:start position:0% +trajectory we're talking about, just +like uh this deal, you want to think of + + align:start position:0% +like uh this deal, you want to think of + + + align:start position:0% +like uh this deal, you want to think of +it that way. I'm directing the energy + + align:start position:0% +it that way. I'm directing the energy + + + align:start position:0% +it that way. I'm directing the energy +source by displacing + + align:start position:0% +source by displacing + + + align:start position:0% +source by displacing +it. That's part of it. But then how do I + + align:start position:0% +it. That's part of it. But then how do I + + + align:start position:0% +it. That's part of it. But then how do I +change the the the + + align:start position:0% +change the the the + + + align:start position:0% +change the the the +um thickness distribution, the parallel + + align:start position:0% +um thickness distribution, the parallel + + + align:start position:0% +um thickness distribution, the parallel +part of the process? Well, I'd actually + + align:start position:0% +part of the process? Well, I'd actually + + + align:start position:0% +part of the process? Well, I'd actually +probably have to change the shape of the + + align:start position:0% +probably have to change the shape of the + + + align:start position:0% +probably have to change the shape of the +rolls, + + align:start position:0% +rolls, + + + align:start position:0% +rolls, +right? You can do a little bit. They + + align:start position:0% +right? You can do a little bit. They + + + align:start position:0% +right? You can do a little bit. They +actually do both sides and that does + + align:start position:0% +actually do both sides and that does + + + align:start position:0% +actually do both sides and that does +help. But let's say I do both sides. So + + align:start position:0% +help. But let's say I do both sides. So + + + align:start position:0% +help. But let's say I do both sides. So +this is exactly right. This is exactly + + align:start position:0% +this is exactly right. This is exactly + + + align:start position:0% +this is exactly right. This is exactly +right. And the middle looks like this, + + align:start position:0% +right. And the middle looks like this, + + + align:start position:0% +right. And the middle looks like this, +which is not uncommon. It becomes fatter + + align:start position:0% +which is not uncommon. It becomes fatter + + + align:start position:0% +which is not uncommon. It becomes fatter +in the middle. What do you do? + + align:start position:0% + + + + align:start position:0% + +Yeah, but I don't want to do that. Yes, + + align:start position:0% +Yeah, but I don't want to do that. Yes, + + + align:start position:0% +Yeah, but I don't want to do that. Yes, +you would change the rolls and and in + + align:start position:0% +you would change the rolls and and in + + + align:start position:0% +you would change the rolls and and in +fact, what they do is they build rolls + + align:start position:0% +fact, what they do is they build rolls + + + align:start position:0% +fact, what they do is they build rolls +with a little bit of a camber in them + + align:start position:0% +with a little bit of a camber in them + + + align:start position:0% +with a little bit of a camber in them +because, you know, the center is going + + align:start position:0% +because, you know, the center is going + + + align:start position:0% +because, you know, the center is going +to deflect up a little bit, so you put + + align:start position:0% +to deflect up a little bit, so you put + + + align:start position:0% +to deflect up a little bit, so you put +some camber into it. Believe it or not, + + align:start position:0% +some camber into it. Believe it or not, + + + align:start position:0% +some camber into it. Believe it or not, +at Alcoa, that's still not good enough. + + align:start position:0% +at Alcoa, that's still not good enough. + + + align:start position:0% +at Alcoa, that's still not good enough. +This stuff is very precise. I think that + + align:start position:0% +This stuff is very precise. I think that + + + align:start position:0% +This stuff is very precise. I think that +I I shouldn't quote the tolerances, but + + align:start position:0% +I I shouldn't quote the tolerances, but + + + align:start position:0% +I I shouldn't quote the tolerances, but +it's it's on the order of uh in in my + + align:start position:0% +it's it's on the order of uh in in my + + + align:start position:0% +it's it's on the order of uh in in my +newly converted SI brain, I think it's + + align:start position:0% +newly converted SI brain, I think it's + + + align:start position:0% +newly converted SI brain, I think it's +could + + align:start position:0% +could + + + align:start position:0% +could +be 15 microns, you know, fra it's it it + + align:start position:0% +be 15 microns, you know, fra it's it it + + + align:start position:0% +be 15 microns, you know, fra it's it it +could be in the 10,000 several 10,000 of + + align:start position:0% +could be in the 10,000 several 10,000 of + + + align:start position:0% +could be in the 10,000 several 10,000 of +an inch in terms of thickness tolerance. + + align:start position:0% +an inch in terms of thickness tolerance. + + + align:start position:0% +an inch in terms of thickness tolerance. +It's not very thick stuff to begin with. + + align:start position:0% +It's not very thick stuff to begin with. + + + align:start position:0% +It's not very thick stuff to begin with. +So like locally heated through heat. + + align:start position:0% +So like locally heated through heat. + + + align:start position:0% +So like locally heated through heat. +Yeah. In fact, that's what done what is + + align:start position:0% +Yeah. In fact, that's what done what is + + + align:start position:0% +Yeah. In fact, that's what done what is +done to get small displacements to be + + align:start position:0% +done to get small displacements to be + + + align:start position:0% +done to get small displacements to be +able to actually arbitrarily not + + align:start position:0% +able to actually arbitrarily not + + + align:start position:0% +able to actually arbitrarily not +arbitrarily but to put you know some + + align:start position:0% +arbitrarily but to put you know some + + + align:start position:0% +arbitrarily but to put you know some +different profiles on that you locally + + align:start position:0% +different profiles on that you locally + + + align:start position:0% +different profiles on that you locally +heat it or cool + + align:start position:0% +heat it or cool + + + align:start position:0% +heat it or cool +it in response to feedback to actually + + align:start position:0% +it in response to feedback to actually + + + align:start position:0% +it in response to feedback to actually +slowly move the tool locally a little + + align:start position:0% +slowly move the tool locally a little + + + align:start position:0% +slowly move the tool locally a little +bit fatter here a little bit less. You + + align:start position:0% +bit fatter here a little bit less. You + + + align:start position:0% +bit fatter here a little bit less. You +can imagine if you only need, you know, + + align:start position:0% +can imagine if you only need, you know, + + + align:start position:0% +can imagine if you only need, you know, +10 micron, something like that, doesn't + + align:start position:0% +10 micron, something like that, doesn't + + + align:start position:0% +10 micron, something like that, doesn't +take a lot of heat. And yes, indeed, + + align:start position:0% +take a lot of heat. And yes, indeed, + + + align:start position:0% +take a lot of heat. And yes, indeed, +you're going to say, "Oh, how localized + + align:start position:0% +you're going to say, "Oh, how localized + + + align:start position:0% +you're going to say, "Oh, how localized +can that be?" And that's the trade + + align:start position:0% +can that be?" And that's the trade + + + align:start position:0% +can that be?" And that's the trade +secret they won't tell anybody about. + + align:start position:0% +secret they won't tell anybody about. + + + align:start position:0% +secret they won't tell anybody about. +But um yeah, so in this particular case, + + align:start position:0% +But um yeah, so in this particular case, + + + align:start position:0% +But um yeah, so in this particular case, +notice these two different modes of + + align:start position:0% +notice these two different modes of + + + align:start position:0% +notice these two different modes of +uh uh two different modes of interaction + + align:start position:0% +uh uh two different modes of interaction + + + align:start position:0% +uh uh two different modes of interaction +lead to two different ways of + + align:start position:0% +lead to two different ways of + + + align:start position:0% +lead to two different ways of +controlling it. In one case, it's very + + align:start position:0% +controlling it. In one case, it's very + + + align:start position:0% +controlling it. In one case, it's very +simple. I'm going to buy a servo system. + + align:start position:0% +simple. I'm going to buy a servo system. + + + align:start position:0% +simple. I'm going to buy a servo system. +It's going to be really good. it's going + + align:start position:0% +It's going to be really good. it's going + + + align:start position:0% +It's going to be really good. it's going +to be very stiff and I'm going to say + + align:start position:0% +to be very stiff and I'm going to say + + + align:start position:0% +to be very stiff and I'm going to say +make that 2000 of an inch gap and you + + align:start position:0% +make that 2000 of an inch gap and you + + + align:start position:0% +make that 2000 of an inch gap and you +get 2,000 of an inch gap. In the other + + align:start position:0% +get 2,000 of an inch gap. In the other + + + align:start position:0% +get 2,000 of an inch gap. In the other +case, it's like oh my gosh, you know, uh + + align:start position:0% +case, it's like oh my gosh, you know, uh + + + align:start position:0% +case, it's like oh my gosh, you know, uh +I've got to change this spatial + + align:start position:0% +I've got to change this spatial + + + align:start position:0% +I've got to change this spatial +distribution somehow. The extreme case + + align:start position:0% +distribution somehow. The extreme case + + + align:start position:0% +distribution somehow. The extreme case +is to shut the thing down, put in a new + + align:start position:0% +is to shut the thing down, put in a new + + + align:start position:0% +is to shut the thing down, put in a new +set of roles and the other is to come up + + align:start position:0% +set of roles and the other is to come up + + + align:start position:0% +set of roles and the other is to come up +with some clever way of deforming it. + + align:start position:0% +with some clever way of deforming it. + + + align:start position:0% +with some clever way of deforming it. +Okay, so why do we worry about the two + + align:start position:0% +Okay, so why do we worry about the two + + + align:start position:0% +Okay, so why do we worry about the two +modes of interaction? It leads directly + + align:start position:0% +modes of interaction? It leads directly + + + align:start position:0% +modes of interaction? It leads directly +to how we would ever find the knobs on + + align:start position:0% +to how we would ever find the knobs on + + + align:start position:0% +to how we would ever find the knobs on +the machine to change what we're doing. + + align:start position:0% +the machine to change what we're doing. + + + align:start position:0% +the machine to change what we're doing. +Now that will become most + + align:start position:0% +Now that will become most + + + align:start position:0% +Now that will become most +important in the last part of the class + + align:start position:0% +important in the last part of the class + + + align:start position:0% +important in the last part of the class +when we talk about process optimization + + align:start position:0% +when we talk about process optimization + + + align:start position:0% +when we talk about process optimization +and you're saying what can I do you know + + align:start position:0% +and you're saying what can I do you know + + + align:start position:0% +and you're saying what can I do you know +what can I actually change on a process + + align:start position:0% +what can I actually change on a process + + + align:start position:0% +what can I actually change on a process +what can I + + align:start position:0% +what can I + + + align:start position:0% +what can I +change real time millisecond what can I + + align:start position:0% +change real time millisecond what can I + + + align:start position:0% +change real time millisecond what can I +change maybe in this case this is a this + + align:start position:0% +change maybe in this case this is a this + + + align:start position:0% +change maybe in this case this is a this +is an unusual example what can I change + + align:start position:0% +is an unusual example what can I change + + + align:start position:0% +is an unusual example what can I change +on on a you know a frequent basis but in + + align:start position:0% +on on a you know a frequent basis but in + + + align:start position:0% +on on a you know a frequent basis but in +most cases the major change you do with + + align:start position:0% +most cases the major change you do with + + + align:start position:0% +most cases the major change you do with +tooling and things like this is on a + + align:start position:0% +tooling and things like this is on a + + + align:start position:0% +tooling and things like this is on a +you know, hourly shift, yearly basis. + + align:start position:0% +you know, hourly shift, yearly basis. + + + align:start position:0% +you know, hourly shift, yearly basis. +So, your ability to affect the output + + align:start position:0% +So, your ability to affect the output + + + align:start position:0% +So, your ability to affect the output +once you've kind of literally cast it in + + align:start position:0% +once you've kind of literally cast it in + + + align:start position:0% +once you've kind of literally cast it in +stone uh is is greatly uh changed by + + align:start position:0% +stone uh is is greatly uh changed by + + + align:start position:0% +stone uh is is greatly uh changed by +whether it's a parallel or ser or serial + + align:start position:0% + + + + align:start position:0% + +process. + + align:start position:0% + + + + align:start position:0% + +Okay. All right. Okay. So, just just to + + align:start position:0% +Okay. All right. Okay. So, just just to + + + align:start position:0% +Okay. All right. Okay. So, just just to +to summarize this again. So for this + + align:start position:0% +to summarize this again. So for this + + + align:start position:0% +to summarize this again. So for this +lumped or serial case um the time + + align:start position:0% +lumped or serial case um the time + + + align:start position:0% +lumped or serial case um the time +trajectory of that interaction port is + + align:start position:0% +trajectory of that interaction port is + + + align:start position:0% +trajectory of that interaction port is +one of the most important things. So + + align:start position:0% +one of the most important things. So + + + align:start position:0% +one of the most important things. So +robotic + + align:start position:0% +robotic + + + align:start position:0% +robotic +manufacturing which was all the rage for + + align:start position:0% +manufacturing which was all the rage for + + + align:start position:0% +manufacturing which was all the rage for +many a year until we found out it wasn't + + align:start position:0% +many a year until we found out it wasn't + + + align:start position:0% +many a year until we found out it wasn't +really such a thing to be rageful about. + + align:start position:0% +really such a thing to be rageful about. + + + align:start position:0% +really such a thing to be rageful about. +Um it it works for a limited class of + + align:start position:0% +Um it it works for a limited class of + + + align:start position:0% +Um it it works for a limited class of +processes pretty well, but uh and your + + align:start position:0% +processes pretty well, but uh and your + + + align:start position:0% +processes pretty well, but uh and your +your classic CNC machine, the CNC + + align:start position:0% +your classic CNC machine, the CNC + + + align:start position:0% +your classic CNC machine, the CNC +machine of the 60s, which sort of got + + align:start position:0% +machine of the 60s, which sort of got + + + align:start position:0% +machine of the 60s, which sort of got +generalized in the 70s and and put + + align:start position:0% +generalized in the 70s and and put + + + align:start position:0% +generalized in the 70s and and put +everywhere essentially means, if you + + align:start position:0% +everywhere essentially means, if you + + + align:start position:0% +everywhere essentially means, if you +want to put in the terminology what + + align:start position:0% +want to put in the terminology what + + + align:start position:0% +want to put in the terminology what +we're talking about today, usually means + + align:start position:0% +we're talking about today, usually means + + + align:start position:0% +we're talking about today, usually means +the ability to control + + align:start position:0% +the ability to control + + + align:start position:0% +the ability to control +trajectories in a very repeatable way. + + align:start position:0% +trajectories in a very repeatable way. + + + align:start position:0% +trajectories in a very repeatable way. +So it's not just the ability a machine + + align:start position:0% +So it's not just the ability a machine + + + align:start position:0% +So it's not just the ability a machine +that can follow a trajectory, it's also + + align:start position:0% +that can follow a trajectory, it's also + + + align:start position:0% +that can follow a trajectory, it's also +the ability to generate the trajectory + + align:start position:0% +the ability to generate the trajectory + + + align:start position:0% +the ability to generate the trajectory +and things like that. And then in this + + align:start position:0% +and things like that. And then in this + + + align:start position:0% +and things like that. And then in this +distributed distri I've used two + + align:start position:0% +distributed distri I've used two + + + align:start position:0% +distributed distri I've used two +different terms here, but distributed or + + align:start position:0% +different terms here, but distributed or + + + align:start position:0% +different terms here, but distributed or +parallel case it's more than anything + + align:start position:0% +parallel case it's more than anything + + + align:start position:0% +parallel case it's more than anything +it's the shape of the energy + + align:start position:0% +it's the shape of the energy + + + align:start position:0% +it's the shape of the energy +distributor. You know patterns, molds, + + align:start position:0% +distributor. You know patterns, molds, + + + align:start position:0% +distributor. You know patterns, molds, +masks, heat distributions, things like + + align:start position:0% +masks, heat distributions, things like + + + align:start position:0% +masks, heat distributions, things like +that. I think we've seen enough + + align:start position:0% +that. I think we've seen enough + + + align:start position:0% +that. I think we've seen enough +examples. We're sick of these + + align:start position:0% +examples. We're sick of these + + + align:start position:0% +examples. We're sick of these +now. Uh oh yeah. Well, you'll see this + + align:start position:0% +now. Uh oh yeah. Well, you'll see this + + + align:start position:0% +now. Uh oh yeah. Well, you'll see this +in a moment, but a lot of the uh + + align:start position:0% +in a moment, but a lot of the uh + + + align:start position:0% +in a moment, but a lot of the uh +so-called um rapid prototyping methods + + align:start position:0% +so-called um rapid prototyping methods + + + align:start position:0% +so-called um rapid prototyping methods +that that popped up in the '9s or solid + + align:start position:0% +that that popped up in the '9s or solid + + + align:start position:0% +that that popped up in the '9s or solid +free form fabrication as it's sometimes + + align:start position:0% +free form fabrication as it's sometimes + + + align:start position:0% +free form fabrication as it's sometimes +as the government likes to call it um + + align:start position:0% +as the government likes to call it um + + + align:start position:0% +as the government likes to call it um +stereoiththography sort of the first big + + align:start position:0% +stereoiththography sort of the first big + + + align:start position:0% +stereoiththography sort of the first big +one on that 3D printing developed here + + align:start position:0% +one on that 3D printing developed here + + + align:start position:0% +one on that 3D printing developed here +um are serial processes and they figured + + align:start position:0% +um are serial processes and they figured + + + align:start position:0% +um are serial processes and they figured +out how to put down in they turn out to + + align:start position:0% +out how to put down in they turn out to + + + align:start position:0% +out how to put down in they turn out to +be usually serial edition type + + align:start position:0% +be usually serial edition type + + + align:start position:0% +be usually serial edition type +processes. is they figured out how to + + align:start position:0% +processes. is they figured out how to + + + align:start position:0% +processes. is they figured out how to +put a dot of material down at a time uh + + align:start position:0% +put a dot of material down at a time uh + + + align:start position:0% +put a dot of material down at a time uh +to build up uh to build up a structure + + align:start position:0% +to build up uh to build up a structure + + + align:start position:0% +to build up uh to build up a structure +and that that dot itself was cohesive + + align:start position:0% +and that that dot itself was cohesive + + + align:start position:0% +and that that dot itself was cohesive +enough that if you put it down it stayed + + align:start position:0% +enough that if you put it down it stayed + + + align:start position:0% +enough that if you put it down it stayed +there and you didn't need anything to + + align:start position:0% +there and you didn't need anything to + + + align:start position:0% +there and you didn't need anything to +hold it. + + align:start position:0% +hold it. + + + align:start position:0% +hold it. +Um and I'll talk more about that in just + + align:start position:0% +Um and I'll talk more about that in just + + + align:start position:0% +Um and I'll talk more about that in just +a moment. But I think we've kind of + + align:start position:0% +a moment. But I think we've kind of + + + align:start position:0% +a moment. But I think we've kind of +talked about you know these are all + + align:start position:0% +talked about you know these are all + + + align:start position:0% +talked about you know these are all +these are all interesting examples. So + + align:start position:0% +these are all interesting examples. So + + + align:start position:0% +these are all interesting examples. So +if we talk about a taxonomy to kind of + + align:start position:0% +if we talk about a taxonomy to kind of + + + align:start position:0% +if we talk about a taxonomy to kind of +bring together the uh the um energy + + align:start position:0% +bring together the uh the um energy + + + align:start position:0% +bring together the uh the um energy +source if you will or for the um + + align:start position:0% +source if you will or for the um + + + align:start position:0% +source if you will or for the um +geometry change the way we apply it + + align:start position:0% +geometry change the way we apply it + + + align:start position:0% +geometry change the way we apply it +um and a couple other things that'll + + align:start position:0% +um and a couple other things that'll + + + align:start position:0% +um and a couple other things that'll +come up in just a second then we can uh + + align:start position:0% +come up in just a second then we can uh + + + align:start position:0% +come up in just a second then we can uh +and I I think I've said why for the for + + align:start position:0% +and I I think I've said why for the for + + + align:start position:0% +and I I think I've said why for the for +the mode uh you know the change mode why + + align:start position:0% +the mode uh you know the change mode why + + + align:start position:0% +the mode uh you know the change mode why +oh actually I haven't I'm sorry about + + align:start position:0% +oh actually I haven't I'm sorry about + + + align:start position:0% +oh actually I haven't I'm sorry about +that Why does it matter? Let me go back + + align:start position:0% +that Why does it matter? Let me go back + + + align:start position:0% +that Why does it matter? Let me go back +to this. I think I won't bother with the + + align:start position:0% +to this. I think I won't bother with the + + + align:start position:0% +to this. I think I won't bother with the +slides. What I called mode before was + + align:start position:0% +slides. What I called mode before was + + + align:start position:0% +slides. What I called mode before was +really my energy source. Why does it + + align:start position:0% +really my energy source. Why does it + + + align:start position:0% +really my energy source. Why does it +matter matter whether I'm + + align:start position:0% +matter matter whether I'm + + + align:start position:0% +matter matter whether I'm +using + + align:start position:0% +using + + + align:start position:0% +using +mechanical, + + align:start position:0% +mechanical, + + + align:start position:0% +mechanical, +electrical, thermal or chemical as my + + align:start position:0% +electrical, thermal or chemical as my + + + align:start position:0% +electrical, thermal or chemical as my +change + + align:start position:0% + + + + align:start position:0% + +agent? What difference does that make? + + align:start position:0% +agent? What difference does that make? + + + align:start position:0% +agent? What difference does that make? +It's just energy, + + align:start position:0% + + + + align:start position:0% + +right? And again, back to to lecture + + align:start position:0% +right? And again, back to to lecture + + + align:start position:0% +right? And again, back to to lecture +one, what do we care about in a process? + + align:start position:0% +one, what do we care about in a process? + + + align:start position:0% +one, what do we care about in a process? +Quality number one in this class, but + + align:start position:0% +Quality number one in this class, but + + + align:start position:0% +Quality number one in this class, but +also we worry about rate and we worry + + align:start position:0% +also we worry about rate and we worry + + + align:start position:0% +also we worry about rate and we worry +about cost, we worry about flexibility. + + align:start position:0% + + + + align:start position:0% + +So with respect + + align:start position:0% +So with respect + + + align:start position:0% +So with respect +to which + + align:start position:0% +to which + + + align:start position:0% +to which +energy mode is involved, what difference + + align:start position:0% +energy mode is involved, what difference + + + align:start position:0% +energy mode is involved, what difference +does it make in this in + + align:start position:0% +does it make in this in + + + align:start position:0% +does it make in this in +this + + align:start position:0% +this + + + align:start position:0% +this +consideration? Simon, please. Or the way + + align:start position:0% +consideration? Simon, please. Or the way + + + align:start position:0% +consideration? Simon, please. Or the way +we can control the process, we need to + + align:start position:0% +we can control the process, we need to + + + align:start position:0% +we can control the process, we need to +know what energy is involved so we can + + align:start position:0% +know what energy is involved so we can + + + align:start position:0% +know what energy is involved so we can +change. Yeah, sure. + + align:start position:0% +change. Yeah, sure. + + + align:start position:0% +change. Yeah, sure. +Absolutely. So I I would control these + + align:start position:0% +Absolutely. So I I would control these + + + align:start position:0% +Absolutely. So I I would control these +in different ways, right? Uh but let's + + align:start position:0% +in different ways, right? Uh but let's + + + align:start position:0% +in different ways, right? Uh but let's +assume I can do that. I I know how to + + align:start position:0% +assume I can do that. I I know how to + + + align:start position:0% +assume I can do that. I I know how to +control mechanical energy. You know, I + + align:start position:0% +control mechanical energy. You know, I + + + align:start position:0% +control mechanical energy. You know, I +can change forces and displacements and + + align:start position:0% +can change forces and displacements and + + + align:start position:0% +can change forces and displacements and +velocities, electrical, you know, + + align:start position:0% +velocities, electrical, you know, + + + align:start position:0% +velocities, electrical, you know, +currents and voltages. Thermal, I can I + + align:start position:0% +currents and voltages. Thermal, I can I + + + align:start position:0% +currents and voltages. Thermal, I can I +can, you know, that's a little bit + + align:start position:0% +can, you know, that's a little bit + + + align:start position:0% +can, you know, that's a little bit +different. I can certainly control + + align:start position:0% +different. I can certainly control + + + align:start position:0% +different. I can certainly control +temperatures. I can also try to control + + align:start position:0% +temperatures. I can also try to control + + + align:start position:0% +temperatures. I can also try to control +their distributions. I can sometimes + + align:start position:0% +their distributions. I can sometimes + + + align:start position:0% +their distributions. I can sometimes +control heat flux is a little bit harder + + align:start position:0% +control heat flux is a little bit harder + + + align:start position:0% +control heat flux is a little bit harder +to do. And chemical, I can control + + align:start position:0% +to do. And chemical, I can control + + + align:start position:0% +to do. And chemical, I can control +concentrations and temperatures and and + + align:start position:0% +concentrations and temperatures and and + + + align:start position:0% +concentrations and temperatures and and +maybe reaction rates as a result of + + align:start position:0% +maybe reaction rates as a result of + + + align:start position:0% +maybe reaction rates as a result of +that. Yeah. matter of size if you're + + align:start position:0% +that. Yeah. matter of size if you're + + + align:start position:0% +that. Yeah. matter of size if you're +affecting a large area or smaller wafer + + align:start position:0% +affecting a large area or smaller wafer + + + align:start position:0% +affecting a large area or smaller wafer +versus a big stack of door for uh yeah + + align:start position:0% +versus a big stack of door for uh yeah + + + align:start position:0% +versus a big stack of door for uh yeah +that's a + + align:start position:0% +that's a + + + align:start position:0% +that's a +um I thought you were going someplace + + align:start position:0% +um I thought you were going someplace + + + align:start position:0% +um I thought you were going someplace +else with that but yes there is a there + + align:start position:0% +else with that but yes there is a there + + + align:start position:0% +else with that but yes there is a there +is a size scaling but what the example + + align:start position:0% +is a size scaling but what the example + + + align:start position:0% +is a size scaling but what the example +you gave actually though a + + align:start position:0% +you gave actually though a + + + align:start position:0% +you gave actually though a +wafer on in terms of the relative size + + align:start position:0% +wafer on in terms of the relative size + + + align:start position:0% +wafer on in terms of the relative size +of the of the the features that I care + + align:start position:0% +of the of the the features that I care + + + align:start position:0% +of the of the the features that I care +about um is actually huge when you think + + align:start position:0% +about um is actually huge when you think + + + align:start position:0% +about um is actually huge when you think +about a wafer compared to a tiny + + align:start position:0% +about a wafer compared to a tiny + + + align:start position:0% +about a wafer compared to a tiny +submicron line and then I think about a + + align:start position:0% +submicron line and then I think about a + + + align:start position:0% +submicron line and then I think about a +car hood with a little, you know, little + + align:start position:0% +car hood with a little, you know, little + + + align:start position:0% +car hood with a little, you know, little +feature in the middle. The wafer is + + align:start position:0% +feature in the middle. The wafer is + + + align:start position:0% +feature in the middle. The wafer is +actually bigger. + + align:start position:0% +actually bigger. + + + align:start position:0% +actually bigger. +Speaking of + + align:start position:0% + + + + align:start position:0% + +the changes. + + align:start position:0% +the changes. + + + align:start position:0% +the changes. +Yeah. Yeah. Yeah. Yeah. Okay. I think I + + align:start position:0% +Yeah. Yeah. Yeah. Yeah. Okay. I think I + + + align:start position:0% +Yeah. Yeah. Yeah. Yeah. Okay. I think I +think you're getting what to what I what + + align:start position:0% +think you're getting what to what I what + + + align:start position:0% +think you're getting what to what I what +I wanted to do. Let me let me see if I + + align:start position:0% +I wanted to do. Let me let me see if I + + + align:start position:0% +I wanted to do. Let me let me see if I +get any more here and then we'll see. + + align:start position:0% +get any more here and then we'll see. + + + align:start position:0% +get any more here and then we'll see. +The rates are definitely different. + + align:start position:0% +The rates are definitely different. + + + align:start position:0% +The rates are definitely different. +faster than + + align:start position:0% +faster than + + + align:start position:0% +faster than +Yeah. Yeah. Believe it or not, when you + + align:start position:0% +Yeah. Yeah. Believe it or not, when you + + + align:start position:0% +Yeah. Yeah. Believe it or not, when you +think about this, you know, you always + + align:start position:0% +think about this, you know, you always + + + align:start position:0% +think about this, you know, you always +think of electrical, oh, that's that's + + align:start position:0% +think of electrical, oh, that's that's + + + align:start position:0% +think of electrical, oh, that's that's +the gigahertz range, right? And all that + + align:start position:0% +the gigahertz range, right? And all that + + + align:start position:0% +the gigahertz range, right? And all that +kind of stuff. And that's true. If all + + align:start position:0% +kind of stuff. And that's true. If all + + + align:start position:0% +kind of stuff. And that's true. If all +you need to do move is move electrons, + + align:start position:0% +you need to do move is move electrons, + + + align:start position:0% +you need to do move is move electrons, +but we have to move material around + + align:start position:0% +but we have to move material around + + + align:start position:0% +but we have to move material around +here. So, this tends to be very fast. If + + align:start position:0% +here. So, this tends to be very fast. If + + + align:start position:0% +here. So, this tends to be very fast. If +I apply a mechanical load to something, + + align:start position:0% +I apply a mechanical load to something, + + + align:start position:0% +I apply a mechanical load to something, +uh, I can modulate that load pretty fast + + align:start position:0% +uh, I can modulate that load pretty fast + + + align:start position:0% +uh, I can modulate that load pretty fast +these days if I want to. And how long + + align:start position:0% +these days if I want to. And how long + + + align:start position:0% +these days if I want to. And how long +when I when I when when I bring a tool + + align:start position:0% +when I when I when when I bring a tool + + + align:start position:0% +when I when I when when I bring a tool +into a a piece of sheet metal like this, + + align:start position:0% +into a a piece of sheet metal like this, + + + align:start position:0% +into a a piece of sheet metal like this, +how long does it take for this to + + align:start position:0% +how long does it take for this to + + + align:start position:0% +how long does it take for this to +react? Well, essentially at the kinds of + + align:start position:0% +react? Well, essentially at the kinds of + + + align:start position:0% +react? Well, essentially at the kinds of +time scales we're talking about, it + + align:start position:0% +time scales we're talking about, it + + + align:start position:0% +time scales we're talking about, it +happens + + align:start position:0% +happens + + + align:start position:0% +happens +instantaneously. Compare that to how + + align:start position:0% +instantaneously. Compare that to how + + + align:start position:0% +instantaneously. Compare that to how +long it takes to etch something or do + + align:start position:0% +long it takes to etch something or do + + + align:start position:0% +long it takes to etch something or do +certain deposition processes. We're + + align:start position:0% +certain deposition processes. We're + + + align:start position:0% +certain deposition processes. We're +doing these nickelplated + + align:start position:0% +doing these nickelplated + + + align:start position:0% +doing these nickelplated +uh micron scale tools. I just saw a + + align:start position:0% +uh micron scale tools. I just saw a + + + align:start position:0% +uh micron scale tools. I just saw a +presentation last night. you know, three + + align:start position:0% +presentation last night. you know, three + + + align:start position:0% +presentation last night. you know, three +days to make a tool with 50 micron + + align:start position:0% +days to make a tool with 50 micron + + + align:start position:0% +days to make a tool with 50 micron +features on it, you know, that's not + + align:start position:0% +features on it, you know, that's not + + + align:start position:0% +features on it, you know, that's not +what you'd call smoking. Um, so pretty + + align:start position:0% +what you'd call smoking. Um, so pretty + + + align:start position:0% +what you'd call smoking. Um, so pretty +low stuff. So rate that we we could + + align:start position:0% +low stuff. So rate that we we could + + + align:start position:0% +low stuff. So rate that we we could +argue different things. You can have + + align:start position:0% +argue different things. You can have + + + align:start position:0% +argue different things. You can have +fast chemical stuff and so forth and so + + align:start position:0% +fast chemical stuff and so forth and so + + + align:start position:0% +fast chemical stuff and so forth and so +on, but in general there's a speed issue + + align:start position:0% +on, but in general there's a speed issue + + + align:start position:0% +on, but in general there's a speed issue +here. What + + align:start position:0% + + + + align:start position:0% + +else? That's rate. What about quality? + + align:start position:0% +else? That's rate. What about quality? + + + align:start position:0% +else? That's rate. What about quality? +tolerance is or also side effects of + + align:start position:0% +tolerance is or also side effects of + + + align:start position:0% +tolerance is or also side effects of +Yeah, side effects. I like that. Yeah. + + align:start position:0% +Yeah, side effects. I like that. Yeah. + + + align:start position:0% +Yeah, side effects. I like that. Yeah. +Say a little bit more about side + + align:start position:0% +Say a little bit more about side + + + align:start position:0% +Say a little bit more about side +effects. Well, you got the theoretical + + align:start position:0% +effects. Well, you got the theoretical + + + align:start position:0% +effects. Well, you got the theoretical +maybe I want to cut a perfect square. + + align:start position:0% +maybe I want to cut a perfect square. + + + align:start position:0% +maybe I want to cut a perfect square. +The tool is not going to cut perfectly + + align:start position:0% +The tool is not going to cut perfectly + + + align:start position:0% +The tool is not going to cut perfectly +square edges, right? Depending on what + + align:start position:0% +square edges, right? Depending on what + + + align:start position:0% +square edges, right? Depending on what +process I use, it may have undercutting + + align:start position:0% +process I use, it may have undercutting + + + align:start position:0% +process I use, it may have undercutting +or rounded edges. Absolutely. + + align:start position:0% +or rounded edges. Absolutely. + + + align:start position:0% +or rounded edges. Absolutely. +Absolutely. So, there there's a there's + + align:start position:0% +Absolutely. So, there there's a there's + + + align:start position:0% +Absolutely. So, there there's a there's +a there's something here inherently + + align:start position:0% +a there's something here inherently + + + align:start position:0% +a there's something here inherently +related to quality. Two at least two + + align:start position:0% +related to quality. Two at least two + + + align:start position:0% +related to quality. Two at least two +things that I can think of. One of them + + align:start position:0% +things that I can think of. One of them + + + align:start position:0% +things that I can think of. One of them +is related to what I'll call uh + + align:start position:0% +is related to what I'll call uh + + + align:start position:0% +is related to what I'll call uh +uh diffusivity in in the general sense + + align:start position:0% +uh diffusivity in in the general sense + + + align:start position:0% +uh diffusivity in in the general sense +not just purely in the thermal sense. If + + align:start position:0% +not just purely in the thermal sense. If + + + align:start position:0% +not just purely in the thermal sense. If +I apply a load to something + + align:start position:0% +I apply a load to something + + + align:start position:0% +I apply a load to something +uh as as you're saying if I apply a load + + align:start position:0% +uh as as you're saying if I apply a load + + + align:start position:0% +uh as as you're saying if I apply a load +to something even with a point tool you + + align:start position:0% +to something even with a point tool you + + + align:start position:0% +to something even with a point tool you +know there's a stress field that + + align:start position:0% +know there's a stress field that + + + align:start position:0% +know there's a stress field that +develops in it and that sort of thing + + align:start position:0% +develops in it and that sort of thing + + + align:start position:0% +develops in it and that sort of thing +and I you can this will be a little bit + + align:start position:0% +and I you can this will be a little bit + + + align:start position:0% +and I you can this will be a little bit +fille but I can make an argument that + + align:start position:0% +fille but I can make an argument that + + + align:start position:0% +fille but I can make an argument that +says okay if I apply that load to here + + align:start position:0% +says okay if I apply that load to here + + + align:start position:0% +says okay if I apply that load to here +it diffuses and so I I wanted to put the + + align:start position:0% +it diffuses and so I I wanted to put the + + + align:start position:0% +it diffuses and so I I wanted to put the +load in in a in a in a tiny point but it + + align:start position:0% +load in in a in a in a tiny point but it + + + align:start position:0% +load in in a in a in a tiny point but it +actually spread out and so I didn't get + + align:start position:0% +actually spread out and so I didn't get + + + align:start position:0% +actually spread out and so I didn't get +exactly what we want. How about if I put + + align:start position:0% +exactly what we want. How about if I put + + + align:start position:0% +exactly what we want. How about if I put +a thermal source in + + align:start position:0% + + + + align:start position:0% + +there? Yeah. And and the worst part is + + align:start position:0% +there? Yeah. And and the worst part is + + + align:start position:0% +there? Yeah. And and the worst part is +not only does it does it dissipate, it + + align:start position:0% +not only does it does it dissipate, it + + + align:start position:0% +not only does it does it dissipate, it +just keeps dissipating. You know, it + + align:start position:0% +just keeps dissipating. You know, it + + + align:start position:0% +just keeps dissipating. You know, it +probably never reaches equilibrium. So, + + align:start position:0% +probably never reaches equilibrium. So, + + + align:start position:0% +probably never reaches equilibrium. So, +it's really going How about chemical uh + + align:start position:0% +it's really going How about chemical uh + + + align:start position:0% +it's really going How about chemical uh +a chemical reaction. You + + align:start position:0% +a chemical reaction. You + + + align:start position:0% +a chemical reaction. You +know, you know, one of the one of the + + align:start position:0% +know, you know, one of the one of the + + + align:start position:0% +know, you know, one of the one of the +problems we have with that, of course, + + align:start position:0% +problems we have with that, of course, + + + align:start position:0% +problems we have with that, of course, +is the if you do thick etching, you have + + align:start position:0% +is the if you do thick etching, you have + + + align:start position:0% +is the if you do thick etching, you have +undercutting because it don't go there, + + align:start position:0% +undercutting because it don't go there, + + + align:start position:0% +undercutting because it don't go there, +but it's going there. You know, it wants + + align:start position:0% +but it's going there. You know, it wants + + + align:start position:0% +but it's going there. You know, it wants +to go everywhere and other things like + + align:start position:0% +to go everywhere and other things like + + + align:start position:0% +to go everywhere and other things like +that. So, again, you have different + + align:start position:0% +that. So, again, you have different + + + align:start position:0% +that. So, again, you have different +diffusion characteristics here depending + + align:start position:0% +diffusion characteristics here depending + + + align:start position:0% +diffusion characteristics here depending +on what's uh going on. So your ability + + align:start position:0% +on what's uh going on. So your ability + + + align:start position:0% +on what's uh going on. So your ability +to control the shape to get a minimum + + align:start position:0% +to control the shape to get a minimum + + + align:start position:0% +to control the shape to get a minimum +feature size to get a level of precision + + align:start position:0% +feature size to get a level of precision + + + align:start position:0% +feature size to get a level of precision +will vary depending on what you have + + align:start position:0% +will vary depending on what you have + + + align:start position:0% +will vary depending on what you have +here. Um and what else do you think is + + align:start position:0% +here. Um and what else do you think is + + + align:start position:0% +here. Um and what else do you think is +important to quality? Obviously my + + align:start position:0% +important to quality? Obviously my + + + align:start position:0% +important to quality? Obviously my +ability to + + align:start position:0% +ability to + + + align:start position:0% +ability to +um sort of direct things exactly where I + + align:start position:0% +um sort of direct things exactly where I + + + align:start position:0% +um sort of direct things exactly where I +want them to be is important. What else + + align:start position:0% +want them to be is important. What else + + + align:start position:0% +want them to be is important. What else +do you think is important to quality? Um + + align:start position:0% +do you think is important to quality? Um + + + align:start position:0% +do you think is important to quality? Um +how about um repeatability? + + align:start position:0% +how about um repeatability? + + + align:start position:0% +how about um repeatability? +Yeah. Sort of the how how um well I can + + align:start position:0% +Yeah. Sort of the how how um well I can + + + align:start position:0% +Yeah. Sort of the how how um well I can +repeatedly apply this energy and have + + align:start position:0% +repeatedly apply this energy and have + + + align:start position:0% +repeatedly apply this energy and have +the same thing happen. Yeah. And that + + align:start position:0% +the same thing happen. Yeah. And that + + + align:start position:0% +the same thing happen. Yeah. And that +will vary uh again depending on the + + align:start position:0% +will vary uh again depending on the + + + align:start position:0% +will vary uh again depending on the +nature of the interfaces here. You know + + align:start position:0% +nature of the interfaces here. You know + + + align:start position:0% +nature of the interfaces here. You know +for example um if thermal conductivity + + align:start position:0% +for example um if thermal conductivity + + + align:start position:0% +for example um if thermal conductivity +is a big part of it and you're + + align:start position:0% +is a big part of it and you're + + + align:start position:0% +is a big part of it and you're +continually bringing new material into + + align:start position:0% +continually bringing new material into + + + align:start position:0% +continually bringing new material into +contact with an old tool it could be a + + align:start position:0% +contact with an old tool it could be a + + + align:start position:0% +contact with an old tool it could be a +different heat transfer coefficient + + align:start position:0% +different heat transfer coefficient + + + align:start position:0% +different heat transfer coefficient +every time. Um, in mechanical cases, if + + align:start position:0% +every time. Um, in mechanical cases, if + + + align:start position:0% +every time. Um, in mechanical cases, if +I'm always coming back with the same + + align:start position:0% +I'm always coming back with the same + + + align:start position:0% +I'm always coming back with the same +tool except for long-term wear, maybe + + align:start position:0% +tool except for long-term wear, maybe + + + align:start position:0% +tool except for long-term wear, maybe +it's a little bit more uh maybe it's a + + align:start position:0% +it's a little bit more uh maybe it's a + + + align:start position:0% +it's a little bit more uh maybe it's a +little bit more + + align:start position:0% +little bit more + + + align:start position:0% +little bit more +repeatable. + + align:start position:0% +repeatable. + + + align:start position:0% +repeatable. +Um, there's one other aspect to it. Now, + + align:start position:0% +Um, there's one other aspect to it. Now, + + + align:start position:0% +Um, there's one other aspect to it. Now, +now think a little bit more about where + + align:start position:0% +now think a little bit more about where + + + align:start position:0% +now think a little bit more about where +we're going with the class with things + + align:start position:0% +we're going with the class with things + + + align:start position:0% +we're going with the class with things +like statistical process control, which + + align:start position:0% +like statistical process control, which + + + align:start position:0% +like statistical process control, which +says, let's find out things that are not + + align:start position:0% +says, let's find out things that are not + + + align:start position:0% +says, let's find out things that are not +quite right with the process and fix + + align:start position:0% +quite right with the process and fix + + + align:start position:0% +quite right with the process and fix +them, and that will improve our quality. + + align:start position:0% +them, and that will improve our quality. + + + align:start position:0% +them, and that will improve our quality. +and and then in uh the more active + + align:start position:0% +and and then in uh the more active + + + align:start position:0% +and and then in uh the more active +process optimization stuff where we say + + align:start position:0% +process optimization stuff where we say + + + align:start position:0% +process optimization stuff where we say +let's adjust things until they're really + + align:start position:0% +let's adjust things until they're really + + + align:start position:0% +let's adjust things until they're really +right. And then we actually at the end + + align:start position:0% +right. And then we actually at the end + + + align:start position:0% +right. And then we actually at the end +we'll talk a little bit about active + + align:start position:0% +we'll talk a little bit about active + + + align:start position:0% +we'll talk a little bit about active +control where you're continually + + align:start position:0% +control where you're continually + + + align:start position:0% +control where you're continually +adjusting. But think of it this + + align:start position:0% +adjusting. But think of it this + + + align:start position:0% +adjusting. But think of it this +way because this is where you you you + + align:start position:0% +way because this is where you you you + + + align:start position:0% +way because this is where you you you +will be thinking about this. Here's the + + align:start position:0% +will be thinking about this. Here's the + + + align:start position:0% +will be thinking about this. Here's the +process. I just measured its result. + + align:start position:0% +process. I just measured its result. + + + align:start position:0% +process. I just measured its result. +It's not good + + align:start position:0% +It's not good + + + align:start position:0% +It's not good +enough. I need to improve its quality + + align:start position:0% +enough. I need to improve its quality + + + align:start position:0% +enough. I need to improve its quality +and I can't go buy a new machine. + + align:start position:0% + + + + align:start position:0% + +So don't So I have to have the ability + + align:start position:0% +So don't So I have to have the ability + + + align:start position:0% +So don't So I have to have the ability +to adjust something, right? I have to + + align:start position:0% +to adjust something, right? I have to + + + align:start position:0% +to adjust something, right? I have to +have the ability to change something. So + + align:start position:0% +have the ability to change something. So + + + align:start position:0% +have the ability to change something. So +think about what it takes to change + + align:start position:0% +think about what it takes to change + + + align:start position:0% +think about what it takes to change +these just as I was saying before with + + align:start position:0% +these just as I was saying before with + + + align:start position:0% +these just as I was saying before with +the rolling pace in the uh in that. + + align:start position:0% +the rolling pace in the uh in that. + + + align:start position:0% +the rolling pace in the uh in that. +Yeah, go ahead. I think for some + + align:start position:0% +Yeah, go ahead. I think for some + + + align:start position:0% +Yeah, go ahead. I think for some +mechanical uh process, it's easier to + + align:start position:0% +mechanical uh process, it's easier to + + + align:start position:0% +mechanical uh process, it's easier to +stop, but for the chemical thermal uh if + + align:start position:0% +stop, but for the chemical thermal uh if + + + align:start position:0% +stop, but for the chemical thermal uh if +you uh even you you know the problem, + + align:start position:0% +you uh even you you know the problem, + + + align:start position:0% +you uh even you you know the problem, +you can hard to stop the process. It's + + align:start position:0% +you can hard to stop the process. It's + + + align:start position:0% +you can hard to stop the process. It's +hard to stop it. I mean, I'm not trying + + align:start position:0% +hard to stop it. I mean, I'm not trying + + + align:start position:0% +hard to stop it. I mean, I'm not trying +to come up with winners and losers here, + + align:start position:0% +to come up with winners and losers here, + + + align:start position:0% +to come up with winners and losers here, +uh, because they all have advantages and + + align:start position:0% +uh, because they all have advantages and + + + align:start position:0% +uh, because they all have advantages and +disadvantages, but you're absolutely + + align:start position:0% +disadvantages, but you're absolutely + + + align:start position:0% +disadvantages, but you're absolutely +right. There are big differences, right? + + align:start position:0% +right. There are big differences, right? + + + align:start position:0% +right. There are big differences, right? +If if, for example, there's a time + + align:start position:0% +If if, for example, there's a time + + + align:start position:0% +If if, for example, there's a time +aspect to it mechanically, and I can + + align:start position:0% +aspect to it mechanically, and I can + + + align:start position:0% +aspect to it mechanically, and I can +pull that force off and it it goes away. + + align:start position:0% +pull that force off and it it goes away. + + + align:start position:0% +pull that force off and it it goes away. +There's not there's a wave that goes + + align:start position:0% +There's not there's a wave that goes + + + align:start position:0% +There's not there's a wave that goes +through the material, but it it it goes + + align:start position:0% +through the material, but it it it goes + + + align:start position:0% +through the material, but it it it goes +at at sonic rates. You know, uh, the + + align:start position:0% +at at sonic rates. You know, uh, the + + + align:start position:0% +at at sonic rates. You know, uh, the +thermal could take a long time to change + + align:start position:0% +thermal could take a long time to change + + + align:start position:0% +thermal could take a long time to change +anything there. And certainly the + + align:start position:0% +anything there. And certainly the + + + align:start position:0% +anything there. And certainly the +chemical um uh depending on scale could + + align:start position:0% +chemical um uh depending on scale could + + + align:start position:0% +chemical um uh depending on scale could +be like that too. Okay. So it is + + align:start position:0% +be like that too. Okay. So it is + + + align:start position:0% +be like that too. Okay. So it is +important to know what these different + + align:start position:0% +important to know what these different + + + align:start position:0% +important to know what these different +energy sources are if only to say + + align:start position:0% +energy sources are if only to say + + + align:start position:0% +energy sources are if only to say +okay these types of things are more + + align:start position:0% +okay these types of things are more + + + align:start position:0% +okay these types of things are more +important when you're really faced with + + align:start position:0% +important when you're really faced with + + + align:start position:0% +important when you're really faced with +the decision of what's the best I could + + align:start position:0% +the decision of what's the best I could + + + align:start position:0% +the decision of what's the best I could +ever expect this process to do. I've + + align:start position:0% +ever expect this process to do. I've + + + align:start position:0% +ever expect this process to do. I've +I've worked I've done SPC I've done + + align:start position:0% +I've worked I've done SPC I've done + + + align:start position:0% +I've worked I've done SPC I've done +process optimization. There's a + + align:start position:0% +process optimization. There's a + + + align:start position:0% +process optimization. There's a +fundamental limitation because it uses + + align:start position:0% +fundamental limitation because it uses + + + align:start position:0% +fundamental limitation because it uses +mechanical energy. I'll never be able to + + align:start position:0% +mechanical energy. I'll never be able to + + + align:start position:0% +mechanical energy. I'll never be able to +do the following or or so on. + + align:start position:0% +do the following or or so on. + + + align:start position:0% +do the following or or so on. +Okay, so you have these types of things + + align:start position:0% +Okay, so you have these types of things + + + align:start position:0% +Okay, so you have these types of things +interacting with how we apply them. Um, + + align:start position:0% +interacting with how we apply them. Um, + + + align:start position:0% +interacting with how we apply them. Um, +and of course it it's you could say it's + + align:start position:0% +and of course it it's you could say it's + + + align:start position:0% +and of course it it's you could say it's +impossible to use all these in all their + + align:start position:0% +impossible to use all these in all their + + + align:start position:0% +impossible to use all these in all their +different ways, but actually that's not + + align:start position:0% +different ways, but actually that's not + + + align:start position:0% +different ways, but actually that's not +entirely true. + + align:start position:0% + + + + align:start position:0% + +Um, + + align:start position:0% +Um, + + + align:start position:0% +Um, +so kind of said all that. So let's go + + align:start position:0% +so kind of said all that. So let's go + + + align:start position:0% +so kind of said all that. So let's go +on. Now this eye chart um is an attempt + + align:start position:0% +on. Now this eye chart um is an attempt + + + align:start position:0% +on. Now this eye chart um is an attempt +to take this entire taxonomy and then + + align:start position:0% +to take this entire taxonomy and then + + + align:start position:0% +to take this entire taxonomy and then +just populate it. uh this chart with + + align:start position:0% +just populate it. uh this chart with + + + align:start position:0% +just populate it. uh this chart with +um some + + align:start position:0% +um some + + + align:start position:0% +um some +examples, you know, and some of these + + align:start position:0% +examples, you know, and some of these + + + align:start position:0% +examples, you know, and some of these +are are are no-brainers and some of them + + align:start position:0% +are are are no-brainers and some of them + + + align:start position:0% +are are are no-brainers and some of them +could be a little bit controversial. But + + align:start position:0% +could be a little bit controversial. But + + + align:start position:0% +could be a little bit controversial. But +so what this says is, you know, across + + align:start position:0% +so what this says is, you know, across + + + align:start position:0% +so what this says is, you know, across +here, this is the the removal mode of + + align:start position:0% +here, this is the the removal mode of + + + align:start position:0% +here, this is the the removal mode of +transformation and here's a addition and + + align:start position:0% +transformation and here's a addition and + + + align:start position:0% +transformation and here's a addition and +here's formation and here's deformation + + align:start position:0% +here's formation and here's deformation + + + align:start position:0% +here's formation and here's deformation +and in each case then it's divided in + + align:start position:0% +and in each case then it's divided in + + + align:start position:0% +and in each case then it's divided in +half with serial and parallel and then + + align:start position:0% +half with serial and parallel and then + + + align:start position:0% +half with serial and parallel and then +four different energy sources. So you + + align:start position:0% +four different energy sources. So you + + + align:start position:0% +four different energy sources. So you +look at each one and say okay where + + align:start position:0% +look at each one and say okay where + + + align:start position:0% +look at each one and say okay where +where's my favorite process you know so + + align:start position:0% +where's my favorite process you know so + + + align:start position:0% +where's my favorite process you know so +serial + + align:start position:0% +serial + + + align:start position:0% +serial +removal mechanical cutting grinding + + align:start position:0% +removal mechanical cutting grinding + + + align:start position:0% +removal mechanical cutting grinding +brooing polishing water jet right water + + align:start position:0% +brooing polishing water jet right water + + + align:start position:0% +brooing polishing water jet right water +jet is mechanical it's be fluid + + align:start position:0% +jet is mechanical it's be fluid + + + align:start position:0% +jet is mechanical it's be fluid +mechanical but it's mechanical + + align:start position:0% +mechanical but it's mechanical + + + align:start position:0% +mechanical but it's mechanical +electrical serial wire EDM take a single + + align:start position:0% +electrical serial wire EDM take a single + + + align:start position:0% +electrical serial wire EDM take a single +skinny little wire drill a hole + + align:start position:0% +skinny little wire drill a hole + + + align:start position:0% +skinny little wire drill a hole +something like + + align:start position:0% +something like + + + align:start position:0% +something like +that put a whole bunch of them together + + align:start position:0% +that put a whole bunch of them together + + + align:start position:0% +that put a whole bunch of them together +do it all at once say with a with a + + align:start position:0% +do it all at once say with a with a + + + align:start position:0% +do it all at once say with a with a +formed electrode code. Now, it's + + align:start position:0% +formed electrode code. Now, it's + + + align:start position:0% +formed electrode code. Now, it's +parallel EDM. Um, + + align:start position:0% +parallel EDM. Um, + + + align:start position:0% +parallel EDM. Um, +photoiththography with a with an with a + + align:start position:0% +photoiththography with a with an with a + + + align:start position:0% +photoiththography with a with an with a +wet etch, if you want to think of it + + align:start position:0% +wet etch, if you want to think of it + + + align:start position:0% +wet etch, if you want to think of it +that way, is basically a parallel + + align:start position:0% +that way, is basically a parallel + + + align:start position:0% +that way, is basically a parallel +process. It's it's etching everywhere at + + align:start position:0% +process. It's it's etching everywhere at + + + align:start position:0% +process. It's it's etching everywhere at +once, but you just happen to put a mask + + align:start position:0% +once, but you just happen to put a mask + + + align:start position:0% +once, but you just happen to put a mask +in a few places. That's your tool. So, + + align:start position:0% +in a few places. That's your tool. So, + + + align:start position:0% +in a few places. That's your tool. So, +that it can't or I'm sorry, resist. + + align:start position:0% +that it can't or I'm sorry, resist. + + + align:start position:0% +that it can't or I'm sorry, resist. +Um, uh, I think Dwayne has already + + align:start position:0% +Um, uh, I think Dwayne has already + + + align:start position:0% +Um, uh, I think Dwayne has already +talked about chemical mechanical + + align:start position:0% +talked about chemical mechanical + + + align:start position:0% +talked about chemical mechanical +polishing, which I'm told by the experts + + align:start position:0% +polishing, which I'm told by the experts + + + align:start position:0% +polishing, which I'm told by the experts +in the field is really mechanical + + align:start position:0% +in the field is really mechanical + + + align:start position:0% +in the field is really mechanical +polishing, right? So, if we take the C + + align:start position:0% +polishing, right? So, if we take the C + + + align:start position:0% +polishing, right? So, if we take the C +off of there, then CMP is a mechanical + + align:start position:0% +off of there, then CMP is a mechanical + + + align:start position:0% +off of there, then CMP is a mechanical +parallel process. If it's chemical + + align:start position:0% +parallel process. If it's chemical + + + align:start position:0% +parallel process. If it's chemical +mechanical process, then I guess it has + + align:start position:0% +mechanical process, then I guess it has + + + align:start position:0% +mechanical process, then I guess it has +to show up in both of them. Which is it? + + align:start position:0% +to show up in both of them. Which is it? + + + align:start position:0% +to show up in both of them. Which is it? +Is it both? The chemistry softens the + + align:start position:0% +Is it both? The chemistry softens the + + + align:start position:0% +Is it both? The chemistry softens the +surface enough. + + align:start position:0% + + + + align:start position:0% + +Okay. But the chemical by itself would + + align:start position:0% +Okay. But the chemical by itself would + + + align:start position:0% +Okay. But the chemical by itself would +not remove any material. Okay. + + align:start position:0% +not remove any material. Okay. + + + align:start position:0% +not remove any material. Okay. +Chemically assisted mechanical + + align:start position:0% +Chemically assisted mechanical + + + align:start position:0% +Chemically assisted mechanical +processing. Okay. And strangely enough, + + align:start position:0% +processing. Okay. And strangely enough, + + + align:start position:0% +processing. Okay. And strangely enough, +the brazing by itself would not remove + + align:start position:0% +the brazing by itself would not remove + + + align:start position:0% +the brazing by itself would not remove +any material any at all. + + align:start position:0% +any material any at all. + + + align:start position:0% +any material any at all. +Interesting. + + align:start position:0% +Interesting. + + + align:start position:0% +Interesting. +Okay. Well, that's actually an example + + align:start position:0% +Okay. Well, that's actually an example + + + align:start position:0% +Okay. Well, that's actually an example +here of where the chemical part is + + align:start position:0% +here of where the chemical part is + + + align:start position:0% +here of where the chemical part is +actually affecting + + align:start position:0% +actually affecting + + + align:start position:0% +actually affecting +properties. Not unusual. So this is + + align:start position:0% +properties. Not unusual. So this is + + + align:start position:0% +properties. Not unusual. So this is +still true if I'm only talking about the + + align:start position:0% +still true if I'm only talking about the + + + align:start position:0% +still true if I'm only talking about the +uh the the uh rem + + align:start position:0% +uh the the uh rem + + + align:start position:0% +uh the the uh rem +uh the geometry change part of it. Yeah. + + align:start position:0% +uh the geometry change part of it. Yeah. + + + align:start position:0% +uh the geometry change part of it. Yeah. +Um there's a bunch of other ones here. + + align:start position:0% +Um there's a bunch of other ones here. + + + align:start position:0% +Um there's a bunch of other ones here. +One of the interesting things is uh if + + align:start position:0% +One of the interesting things is uh if + + + align:start position:0% +One of the interesting things is uh if +you come over here to something like hot + + align:start position:0% +you come over here to something like hot + + + align:start position:0% +you come over here to something like hot +isostatic pressing a powder metal powder + + align:start position:0% +isostatic pressing a powder metal powder + + + align:start position:0% +isostatic pressing a powder metal powder +metallurgy or powder ceramic process + + align:start position:0% +metallurgy or powder ceramic process + + + align:start position:0% +metallurgy or powder ceramic process +where you take you know uniform powders + + align:start position:0% +where you take you know uniform powders + + + align:start position:0% +where you take you know uniform powders +and compress them in a mold. So that's + + align:start position:0% +and compress them in a mold. So that's + + + align:start position:0% +and compress them in a mold. So that's +obviously an addition process. And then + + align:start position:0% +obviously an addition process. And then + + + align:start position:0% +obviously an addition process. And then +I cinch them and then I do other stuff + + align:start position:0% +I cinch them and then I do other stuff + + + align:start position:0% +I cinch them and then I do other stuff +to it. And I do it all at once in a in a + + align:start position:0% +to it. And I do it all at once in a in a + + + align:start position:0% +to it. And I do it all at once in a in a +in a form tool, a can. Um, and I'm all + + align:start position:0% +in a form tool, a can. Um, and I'm all + + + align:start position:0% +in a form tool, a can. Um, and I'm all +set. + + align:start position:0% +set. + + + align:start position:0% +set. +Um, that's clearly clearly clearly a + + align:start position:0% +Um, that's clearly clearly clearly a + + + align:start position:0% +Um, that's clearly clearly clearly a +parallel process and the result depends + + align:start position:0% +parallel process and the result depends + + + align:start position:0% +parallel process and the result depends +primarily on the shape of the can. + + align:start position:0% +primarily on the shape of the can. + + + align:start position:0% +primarily on the shape of the can. +Um then uh Ellie Saxs at MIT kind of + + align:start position:0% +Um then uh Ellie Saxs at MIT kind of + + + align:start position:0% +Um then uh Ellie Saxs at MIT kind of +invented this process called 3D + + align:start position:0% +invented this process called 3D + + + align:start position:0% +invented this process called 3D +printing. And if you look at 3D + + align:start position:0% +printing. And if you look at 3D + + + align:start position:0% +printing. And if you look at 3D +printing, it's it's not exactly this, + + align:start position:0% +printing, it's it's not exactly this, + + + align:start position:0% +printing, it's it's not exactly this, +but it's essentially the same as saying, + + align:start position:0% +but it's essentially the same as saying, + + + align:start position:0% +but it's essentially the same as saying, +okay, I'm going to uh put down each + + align:start position:0% +okay, I'm going to uh put down each + + + align:start position:0% +okay, I'm going to uh put down each +piece of that powder one piece at a + + align:start position:0% +piece of that powder one piece at a + + + align:start position:0% +piece of that powder one piece at a +time. He does it by joining the powder + + align:start position:0% +time. He does it by joining the powder + + + align:start position:0% +time. He does it by joining the powder +one drop at a time. He puts a binder on + + align:start position:0% +one drop at a time. He puts a binder on + + + align:start position:0% +one drop at a time. He puts a binder on +it. Instead of binding it all at once, + + align:start position:0% +it. Instead of binding it all at once, + + + align:start position:0% +it. Instead of binding it all at once, +he puts a drop down at a time. It's an + + align:start position:0% +he puts a drop down at a time. It's an + + + align:start position:0% +he puts a drop down at a time. It's an +inkjet type process. Um, now it becomes + + align:start position:0% +inkjet type process. Um, now it becomes + + + align:start position:0% +inkjet type process. Um, now it becomes +a serial process. And think about the + + align:start position:0% +a serial process. And think about the + + + align:start position:0% +a serial process. And think about the +difference between these two processes. + + align:start position:0% +difference between these two processes. + + + align:start position:0% +difference between these two processes. +You know, if I've got this big press + + align:start position:0% +You know, if I've got this big press + + + align:start position:0% +You know, if I've got this big press +that has to push this this powder into a + + align:start position:0% +that has to push this this powder into a + + + align:start position:0% +that has to push this this powder into a +green compact, um, big piece of + + align:start position:0% +green compact, um, big piece of + + + align:start position:0% +green compact, um, big piece of +equipment, got to have an expensive + + align:start position:0% +equipment, got to have an expensive + + + align:start position:0% +equipment, got to have an expensive +tool. Whereas this 3D printing, you + + align:start position:0% +tool. Whereas this 3D printing, you + + + align:start position:0% +tool. Whereas this 3D printing, you +know, it's a desktop thing. There are + + align:start position:0% +know, it's a desktop thing. There are + + + align:start position:0% +know, it's a desktop thing. There are +desktop versions of it. Desktop thing. + + align:start position:0% +desktop versions of it. Desktop thing. + + + align:start position:0% +desktop versions of it. Desktop thing. +All I have to do is type in a a CAD + + align:start position:0% +All I have to do is type in a a CAD + + + align:start position:0% +All I have to do is type in a a CAD +file. It does a section + + align:start position:0% +file. It does a section + + + align:start position:0% +file. It does a section +file of it. It creates this thing and + + align:start position:0% +file of it. It creates this thing and + + + align:start position:0% +file of it. It creates this thing and +I've got essentially equivalent parts. + + align:start position:0% +I've got essentially equivalent parts. + + + align:start position:0% +I've got essentially equivalent parts. +Not exactly equivalent, centrally + + align:start position:0% +Not exactly equivalent, centrally + + + align:start position:0% +Not exactly equivalent, centrally +equivalent parts. So clearly this serial + + align:start position:0% +equivalent parts. So clearly this serial + + + align:start position:0% +equivalent parts. So clearly this serial +process is much more + + align:start position:0% +process is much more + + + align:start position:0% +process is much more +flexible. Really great. And I + + align:start position:0% +flexible. Really great. And I + + + align:start position:0% +flexible. Really great. And I +probably can control the quality better + + align:start position:0% +probably can control the quality better + + + align:start position:0% +probably can control the quality better +because if it's not quite right, I just + + align:start position:0% +because if it's not quite right, I just + + + align:start position:0% +because if it's not quite right, I just +change the program a little bit. Right? + + align:start position:0% +change the program a little bit. Right? + + + align:start position:0% +change the program a little bit. Right? +It was a little bit too wide. The last + + align:start position:0% +It was a little bit too wide. The last + + + align:start position:0% +It was a little bit too wide. The last +one I made, I said, "Well, let's let's + + align:start position:0% +one I made, I said, "Well, let's let's + + + align:start position:0% +one I made, I said, "Well, let's let's +reprogram the geometry and bring it in a + + align:start position:0% +reprogram the geometry and bring it in a + + + align:start position:0% +reprogram the geometry and bring it in a +little bit." And it just doesn't. + + align:start position:0% +little bit." And it just doesn't. + + + align:start position:0% +little bit." And it just doesn't. +Whereas, if I'm doing the hot isoatic + + align:start position:0% +Whereas, if I'm doing the hot isoatic + + + align:start position:0% +Whereas, if I'm doing the hot isoatic +pressing, I've got this big expensive + + align:start position:0% +pressing, I've got this big expensive + + + align:start position:0% +pressing, I've got this big expensive +tool and it's not quite right and I + + align:start position:0% +tool and it's not quite right and I + + + align:start position:0% +tool and it's not quite right and I +can't heat it and cool it like I did + + align:start position:0% +can't heat it and cool it like I did + + + align:start position:0% +can't heat it and cool it like I did +with the the uh the rolls on the + + align:start position:0% +with the the uh the rolls on the + + + align:start position:0% +with the the uh the rolls on the +aluminum. I'm kind of stuck with it. + + align:start position:0% +aluminum. I'm kind of stuck with it. + + + align:start position:0% +aluminum. I'm kind of stuck with it. +Right. So, why would anybody do HIP when + + align:start position:0% +Right. So, why would anybody do HIP when + + + align:start position:0% +Right. So, why would anybody do HIP when +you've got 3D printing? + + align:start position:0% + + + + align:start position:0% + +Rate and cost. Absolutely. You know, you + + align:start position:0% +Rate and cost. Absolutely. You know, you + + + align:start position:0% +Rate and cost. Absolutely. You know, you +do the high hot isostatic pressing in + + align:start position:0% +do the high hot isostatic pressing in + + + align:start position:0% +do the high hot isostatic pressing in +minutes, seconds, that sort of thing. + + align:start position:0% +minutes, seconds, that sort of thing. + + + align:start position:0% +minutes, seconds, that sort of thing. +these again the the 3D printing the fast + + align:start position:0% +these again the the 3D printing the fast + + + align:start position:0% +these again the the 3D printing the fast +ones are going to take you minutes to uh + + align:start position:0% +ones are going to take you minutes to uh + + + align:start position:0% +ones are going to take you minutes to uh +to hours and it's volume dependent + + align:start position:0% +to hours and it's volume dependent + + + align:start position:0% +to hours and it's volume dependent +whereas with the hip it's much much less + + align:start position:0% +whereas with the hip it's much much less + + + align:start position:0% +whereas with the hip it's much much less +so so + + align:start position:0% +so so + + + align:start position:0% +so so +um in general why does anybody do + + align:start position:0% +um in general why does anybody do + + + align:start position:0% +um in general why does anybody do +parallel processing because it's really + + align:start position:0% +parallel processing because it's really + + + align:start position:0% +parallel processing because it's really +fast and the example I always like to + + align:start position:0% +fast and the example I always like to + + + align:start position:0% +fast and the example I always like to +give is imagine if if someone took a + + align:start position:0% +give is imagine if if someone took a + + + align:start position:0% +give is imagine if if someone took a +block of uh steel or better yet + + align:start position:0% +block of uh steel or better yet + + + align:start position:0% +block of uh steel or better yet +aluminum and said okay I'm going to make + + align:start position:0% +aluminum and said okay I'm going to make + + + align:start position:0% +aluminum and said okay I'm going to make +all the body panels for your car the + + align:start position:0% +all the body panels for your car the + + + align:start position:0% +all the body panels for your car the +thin little body panels with my machine + + align:start position:0% +thin little body panels with my machine + + + align:start position:0% +thin little body panels with my machine +tool over + + align:start position:0% +tool over + + + align:start position:0% +tool over +here. You know, just imagine that what + + align:start position:0% +here. You know, just imagine that what + + + align:start position:0% +here. You know, just imagine that what +that what it would take to to build that + + align:start position:0% +that what it would take to to build that + + + align:start position:0% +that what it would take to to build that +as opposed to uh going to a high-speed + + align:start position:0% +as opposed to uh going to a high-speed + + + align:start position:0% +as opposed to uh going to a high-speed +modern high-speed stamping shop. Has + + align:start position:0% +modern high-speed stamping shop. Has + + + align:start position:0% +modern high-speed stamping shop. Has +anybody seen automobile body stamping + + align:start position:0% +anybody seen automobile body stamping + + + align:start position:0% +anybody seen automobile body stamping +going on? Yeah. How long does it take to + + align:start position:0% +going on? Yeah. How long does it take to + + + align:start position:0% +going on? Yeah. How long does it take to +make side panel for a car with like + + align:start position:0% +make side panel for a car with like + + + align:start position:0% +make side panel for a car with like +integral door frames and all that other + + align:start position:0% +integral door frames and all that other + + + align:start position:0% +integral door frames and all that other +stuff? Each given operation probably + + align:start position:0% +stuff? Each given operation probably + + + align:start position:0% +stuff? Each given operation probably +takes about two seconds. there's there's + + align:start position:0% +takes about two seconds. there's there's + + + align:start position:0% +takes about two seconds. there's there's +multiple stages. So maybe we'll give it + + align:start position:0% +multiple stages. So maybe we'll give it + + + align:start position:0% +multiple stages. So maybe we'll give it +10 seconds by the time it's done, you + + align:start position:0% +10 seconds by the time it's done, you + + + align:start position:0% +10 seconds by the time it's done, you +know, but blank metal in one end and + + align:start position:0% +know, but blank metal in one end and + + + align:start position:0% +know, but blank metal in one end and +these huge complex structures coming out + + align:start position:0% +these huge complex structures coming out + + + align:start position:0% +these huge complex structures coming out +the other end at incredible rates. Uh + + align:start position:0% +the other end at incredible rates. Uh + + + align:start position:0% +the other end at incredible rates. Uh +you're not going to do that with a + + align:start position:0% +you're not going to do that with a + + + align:start position:0% +you're not going to do that with a +serial process. Uh although I will say + + align:start position:0% +serial process. Uh although I will say + + + align:start position:0% +serial process. Uh although I will say +they've done some things with laser + + align:start position:0% +they've done some things with laser + + + align:start position:0% +they've done some things with laser +cutting and laser welding where that + + align:start position:0% +cutting and laser welding where that + + + align:start position:0% +cutting and laser welding where that +thing really whips along. Uh but uh it's + + align:start position:0% +thing really whips along. Uh but uh it's + + + align:start position:0% +thing really whips along. Uh but uh it's +it's still got a ways to go and it's + + align:start position:0% +it's still got a ways to go and it's + + + align:start position:0% +it's still got a ways to go and it's +much more costly. So all these things uh + + align:start position:0% +much more costly. So all these things uh + + + align:start position:0% +much more costly. So all these things uh +do matter and they uh they come in + + align:start position:0% +do matter and they uh they come in + + + align:start position:0% +do matter and they uh they come in +different ways. Oh. Um, just because I I + + align:start position:0% +different ways. Oh. Um, just because I I + + + align:start position:0% +different ways. Oh. Um, just because I I +always uh like to do this + + align:start position:0% +always uh like to do this + + + align:start position:0% +always uh like to do this +stereoliththography. How does that + + align:start position:0% + + + + align:start position:0% + +work? It's a rapid It it was the + + align:start position:0% +work? It's a rapid It it was the + + + align:start position:0% +work? It's a rapid It it was the +original I think the original rapid + + align:start position:0% +original I think the original rapid + + + align:start position:0% +original I think the original rapid +prototyping process. Anybody know what + + align:start position:0% +prototyping process. Anybody know what + + + align:start position:0% +prototyping process. Anybody know what +stereo uh what's the is what's the trade + + align:start position:0% +stereo uh what's the is what's the trade + + + align:start position:0% +stereo uh what's the is what's the trade +name for that now? That's the most + + align:start position:0% +name for that now? That's the most + + + align:start position:0% +name for that now? That's the most +commercial of them. There's a machine + + align:start position:0% +commercial of them. There's a machine + + + align:start position:0% +commercial of them. There's a machine +right down the far end of this hallway + + align:start position:0% +right down the far end of this hallway + + + align:start position:0% +right down the far end of this hallway +in the architecture department that's an + + align:start position:0% +in the architecture department that's an + + + align:start position:0% +in the architecture department that's an +STL machine. Um stereoiththography. Ah, + + align:start position:0% +STL machine. Um stereoiththography. Ah, + + + align:start position:0% +STL machine. Um stereoiththography. Ah, +I guess it's become pass. Yeah, Adam. + + align:start position:0% +I guess it's become pass. Yeah, Adam. + + + align:start position:0% +I guess it's become pass. Yeah, Adam. +It's just I don't know what the liquid + + align:start position:0% +It's just I don't know what the liquid + + + align:start position:0% +It's just I don't know what the liquid +is, but you select that liquid material. + + align:start position:0% + + + + align:start position:0% + +Yeah, as I as I That's right. There + + align:start position:0% +Yeah, as I as I That's right. There + + + align:start position:0% +Yeah, as I as I That's right. There +there are these photocurable + + align:start position:0% +there are these photocurable + + + align:start position:0% +there are these photocurable +polymers that will be in a liquid state + + align:start position:0% +polymers that will be in a liquid state + + + align:start position:0% +polymers that will be in a liquid state +at room temperature and with just + + align:start position:0% +at room temperature and with just + + + align:start position:0% +at room temperature and with just +regular light on them. But if you hit + + align:start position:0% +regular light on them. But if you hit + + + align:start position:0% +regular light on them. But if you hit +them with the right wavelength light, + + align:start position:0% +them with the right wavelength light, + + + align:start position:0% +them with the right wavelength light, +they will polymerize. you know, they're + + align:start position:0% +they will polymerize. you know, they're + + + align:start position:0% +they will polymerize. you know, they're +UV curable polymers that that are used + + align:start position:0% +UV curable polymers that that are used + + + align:start position:0% +UV curable polymers that that are used +for a lot of things, uh, like contact + + align:start position:0% +for a lot of things, uh, like contact + + + align:start position:0% +for a lot of things, uh, like contact +lenses and things like that. Um, but, + + align:start position:0% +lenses and things like that. Um, but, + + + align:start position:0% +lenses and things like that. Um, but, +uh, this particular case, what they said + + align:start position:0% +uh, this particular case, what they said + + + align:start position:0% +uh, this particular case, what they said +is, well, instead of putting it in a + + align:start position:0% +is, well, instead of putting it in a + + + align:start position:0% +is, well, instead of putting it in a +mold and flashing it with UV light + + align:start position:0% +mold and flashing it with UV light + + + align:start position:0% +mold and flashing it with UV light +everywhere, what if we put a little tiny + + align:start position:0% +everywhere, what if we put a little tiny + + + align:start position:0% +everywhere, what if we put a little tiny +spot of UV light on it? Will it form a + + align:start position:0% +spot of UV light on it? Will it form a + + + align:start position:0% +spot of UV light on it? Will it form a +little ball of of polymer? And the + + align:start position:0% +little ball of of polymer? And the + + + align:start position:0% +little ball of of polymer? And the +answer was sort of, yeah. Uh, so they + + align:start position:0% +answer was sort of, yeah. Uh, so they + + + align:start position:0% +answer was sort of, yeah. Uh, so they +have a you have this bath, I think. + + align:start position:0% +have a you have this bath, I think. + + + align:start position:0% +have a you have this bath, I think. +Again, I I I haven't walked by there + + align:start position:0% +Again, I I I haven't walked by there + + + align:start position:0% +Again, I I I haven't walked by there +this month, but there used to be in one + + align:start position:0% +this month, but there used to be in one + + + align:start position:0% +this month, but there used to be in one +of these glasswalled classrooms down + + align:start position:0% +of these glasswalled classrooms down + + + align:start position:0% +of these glasswalled classrooms down +here at the far end of the fourth floor + + align:start position:0% +here at the far end of the fourth floor + + + align:start position:0% +here at the far end of the fourth floor +in in the architecture department this + + align:start position:0% +in in the architecture department this + + + align:start position:0% +in in the architecture department this +white box with a clear window in it. And + + align:start position:0% +white box with a clear window in it. And + + + align:start position:0% +white box with a clear window in it. And +it's kind of lit up and there's usually + + align:start position:0% +it's kind of lit up and there's usually + + + align:start position:0% +it's kind of lit up and there's usually +something going on in there. And what + + align:start position:0% +something going on in there. And what + + + align:start position:0% +something going on in there. And what +you'll see is is a bath of nearly + + align:start position:0% +you'll see is is a bath of nearly + + + align:start position:0% +you'll see is is a bath of nearly +colorless liquid with a platin on it. + + align:start position:0% +colorless liquid with a platin on it. + + + align:start position:0% +colorless liquid with a platin on it. +And the platin starts at the top with a + + align:start position:0% +And the platin starts at the top with a + + + align:start position:0% +And the platin starts at the top with a +very thin layer of of uh fluid on it. + + align:start position:0% +very thin layer of of uh fluid on it. + + + align:start position:0% +very thin layer of of uh fluid on it. +And this laser, usually not visible, but + + align:start position:0% +And this laser, usually not visible, but + + + align:start position:0% +And this laser, usually not visible, but +this laser will be dancing across the + + align:start position:0% +this laser will be dancing across the + + + align:start position:0% +this laser will be dancing across the +surface tracing an outline. And that + + align:start position:0% +surface tracing an outline. And that + + + align:start position:0% +surface tracing an outline. And that +outline will will become solid. And once + + align:start position:0% +outline will will become solid. And once + + + align:start position:0% +outline will will become solid. And once +it's polymerized, it'll move it down and + + align:start position:0% +it's polymerized, it'll move it down and + + + align:start position:0% +it's polymerized, it'll move it down and +it'll do it again. So it's it's + + align:start position:0% +it'll do it again. So it's it's + + + align:start position:0% +it'll do it again. So it's it's +basically reacting causing a chemical + + align:start position:0% +basically reacting causing a chemical + + + align:start position:0% +basically reacting causing a chemical +reaction or in this case a + + align:start position:0% +reaction or in this case a + + + align:start position:0% +reaction or in this case a +polymerization reaction at a very small + + align:start position:0% +polymerization reaction at a very small + + + align:start position:0% +polymerization reaction at a very small +area by by hitting it with the right + + align:start position:0% +area by by hitting it with the right + + + align:start position:0% +area by by hitting it with the right +amount of activation + + align:start position:0% +amount of activation + + + align:start position:0% +amount of activation +energy. Okay. So that's uh + + align:start position:0% +energy. Okay. So that's uh + + + align:start position:0% +energy. Okay. So that's uh +stereoiththography. That would be a + + align:start position:0% +stereoiththography. That would be a + + + align:start position:0% +stereoiththography. That would be a +serial + + align:start position:0% +serial + + + align:start position:0% +serial +chemical formation process. You're going + + align:start position:0% +chemical formation process. You're going + + + align:start position:0% +chemical formation process. You're going +from liquid to + + align:start position:0% +from liquid to + + + align:start position:0% +from liquid to +solid. + + align:start position:0% +solid. + + + align:start position:0% +solid. +Um, we also do, in fact, I I was here + + align:start position:0% +Um, we also do, in fact, I I was here + + + align:start position:0% +Um, we also do, in fact, I I was here +last night listening to a PhD thesis + + align:start position:0% +last night listening to a PhD thesis + + + align:start position:0% +last night listening to a PhD thesis +from Singapore where what they did is + + align:start position:0% +from Singapore where what they did is + + + align:start position:0% +from Singapore where what they did is +they took a mold, poured UV curable + + align:start position:0% +they took a mold, poured UV curable + + + align:start position:0% +they took a mold, poured UV curable +polymer on it, flashed it with with a UV + + align:start position:0% +polymer on it, flashed it with with a UV + + + align:start position:0% +polymer on it, flashed it with with a UV +lamp over the whole thing for + + align:start position:0% +lamp over the whole thing for + + + align:start position:0% +lamp over the whole thing for +about about 30 seconds or something, I + + align:start position:0% +about about 30 seconds or something, I + + + align:start position:0% +about about 30 seconds or something, I +think, and then pulled it apart. Okay. + + align:start position:0% +think, and then pulled it apart. Okay. + + + align:start position:0% +think, and then pulled it apart. Okay. +And it was all about the mold, the mold + + align:start position:0% +And it was all about the mold, the mold + + + align:start position:0% +And it was all about the mold, the mold +quality and and filling and that sort of + + align:start position:0% +quality and and filling and that sort of + + + align:start position:0% +quality and and filling and that sort of +thing. So, um, and it's all about, you + + align:start position:0% +thing. So, um, and it's all about, you + + + align:start position:0% +thing. So, um, and it's all about, you +know, 90% of her thesis was about, well, + + align:start position:0% +know, 90% of her thesis was about, well, + + + align:start position:0% +know, 90% of her thesis was about, well, +not 90%, a good percentage of her thesis + + align:start position:0% +not 90%, a good percentage of her thesis + + + align:start position:0% +not 90%, a good percentage of her thesis +was about making the molds and how well + + align:start position:0% +was about making the molds and how well + + + align:start position:0% +was about making the molds and how well +could I extract this thing from the + + align:start position:0% +could I extract this thing from the + + + align:start position:0% +could I extract this thing from the +mold. So physically the same material, + + align:start position:0% +mold. So physically the same material, + + + align:start position:0% +mold. So physically the same material, +the same process, but in this case a + + align:start position:0% +the same process, but in this case a + + + align:start position:0% +the same process, but in this case a +really good example of going from a + + align:start position:0% +really good example of going from a + + + align:start position:0% +really good example of going from a +directed energy source that was a point + + align:start position:0% +directed energy source that was a point + + + align:start position:0% +directed energy source that was a point +to a directed energy source source that + + align:start position:0% +to a directed energy source source that + + + align:start position:0% +to a directed energy source source that +was really this entire surface. So I + + align:start position:0% +was really this entire surface. So I + + + align:start position:0% +was really this entire surface. So I +guess my point is and now I guess it's + + align:start position:0% +guess my point is and now I guess it's + + + align:start position:0% +guess my point is and now I guess it's +it's getting a little bit dated but when + + align:start position:0% +it's getting a little bit dated but when + + + align:start position:0% +it's getting a little bit dated but when +when uh these uh rapid prototyping + + align:start position:0% +when uh these uh rapid prototyping + + + align:start position:0% +when uh these uh rapid prototyping +processes were all the rage it was + + align:start position:0% +processes were all the rage it was + + + align:start position:0% +processes were all the rage it was +interesting to notice that on this + + align:start position:0% +interesting to notice that on this + + + align:start position:0% +interesting to notice that on this +taxonomy they simply were the fact that + + align:start position:0% +taxonomy they simply were the fact that + + + align:start position:0% +taxonomy they simply were the fact that +that some people realized and it's been + + align:start position:0% +that some people realized and it's been + + + align:start position:0% +that some people realized and it's been +done for a lot of different things not + + align:start position:0% +done for a lot of different things not + + + align:start position:0% +done for a lot of different things not +just these but people realized that I + + align:start position:0% +just these but people realized that I + + + align:start position:0% +just these but people realized that I +can take a parallel process and if I + + align:start position:0% +can take a parallel process and if I + + + align:start position:0% +can take a parallel process and if I +serialize it it all of a sudden becomes + + align:start position:0% +serialize it it all of a sudden becomes + + + align:start position:0% +serialize it it all of a sudden becomes +a rapid free form uh method doesn't need + + align:start position:0% +a rapid free form uh method doesn't need + + + align:start position:0% +a rapid free form uh method doesn't need +any tooling. And so you've got that + + align:start position:0% +any tooling. And so you've got that + + + align:start position:0% +any tooling. And so you've got that +example. You've got uh what turns out to + + align:start position:0% +example. You've got uh what turns out to + + + align:start position:0% +example. You've got uh what turns out to +be uh I guess I'd call it it's like sort + + align:start position:0% +be uh I guess I'd call it it's like sort + + + align:start position:0% +be uh I guess I'd call it it's like sort +of like a reaction molding parallel + + align:start position:0% +of like a reaction molding parallel + + + align:start position:0% +of like a reaction molding parallel +reaction process to a serial reaction + + align:start position:0% +reaction process to a serial reaction + + + align:start position:0% +reaction process to a serial reaction +process. There's also um this you know + + align:start position:0% +process. There's also um this you know + + + align:start position:0% +process. There's also um this you know +with powdered metals you can center them + + align:start position:0% +with powdered metals you can center them + + + align:start position:0% +with powdered metals you can center them +thermally to get the shape. And when + + align:start position:0% +thermally to get the shape. And when + + + align:start position:0% +thermally to get the shape. And when +people decided they could cinder it + + align:start position:0% +people decided they could cinder it + + + align:start position:0% +people decided they could cinder it +locally with a laser, you could take a + + align:start position:0% +locally with a laser, you could take a + + + align:start position:0% +locally with a laser, you could take a +powder of of metal and zap it with a + + align:start position:0% +powder of of metal and zap it with a + + + align:start position:0% +powder of of metal and zap it with a +laser and just get things to center to + + align:start position:0% +laser and just get things to center to + + + align:start position:0% +laser and just get things to center to +each other uh locally. Okay. So they got + + align:start position:0% +each other uh locally. Okay. So they got + + + align:start position:0% +each other uh locally. Okay. So they got +they they changed the whole equation on + + align:start position:0% +they they changed the whole equation on + + + align:start position:0% +they they changed the whole equation on +how the process is controlled which has + + align:start position:0% +how the process is controlled which has + + + align:start position:0% +how the process is controlled which has +effects on all these different uh + + align:start position:0% +effects on all these different uh + + + align:start position:0% +effects on all these different uh +things. + + align:start position:0% +things. + + + align:start position:0% +things. +Last thing, because we're not going to + + align:start position:0% +Last thing, because we're not going to + + + align:start position:0% +Last thing, because we're not going to +talk about it much for the rest of the + + align:start position:0% +talk about it much for the rest of the + + + align:start position:0% +talk about it much for the rest of the +term, but because it's an extremely has + + align:start position:0% +term, but because it's an extremely has + + + align:start position:0% +term, but because it's an extremely has +been an extremely important part of + + align:start position:0% +been an extremely important part of + + + align:start position:0% +been an extremely important part of +manufacturing, interestingly fading in + + align:start position:0% +manufacturing, interestingly fading in + + + align:start position:0% +manufacturing, interestingly fading in +recent years for good and sufficient + + align:start position:0% +recent years for good and sufficient + + + align:start position:0% +recent years for good and sufficient +reasons, is flexibility. + + align:start position:0% + + + + align:start position:0% + +What do you + + align:start position:0% +What do you + + + align:start position:0% +What do you +think about if I if I were to go to + + align:start position:0% +think about if I if I were to go to + + + align:start position:0% +think about if I if I were to go to +different corners of this taxonomy and + + align:start position:0% +different corners of this taxonomy and + + + align:start position:0% +different corners of this taxonomy and +say, "All + + align:start position:0% +say, "All + + + align:start position:0% +say, "All +right, so let's put a flexibility + + align:start position:0% +right, so let's put a flexibility + + + align:start position:0% +right, so let's put a flexibility +overlay on + + align:start position:0% +overlay on + + + align:start position:0% +overlay on +this." And we'll talk about um you know, + + align:start position:0% +this." And we'll talk about um you know, + + + align:start position:0% +this." And we'll talk about um you know, +flexibility here, I guess. Well, two two + + align:start position:0% +flexibility here, I guess. Well, two two + + + align:start position:0% +flexibility here, I guess. Well, two two +common ways of looking at flexibility + + align:start position:0% +common ways of looking at flexibility + + + align:start position:0% +common ways of looking at flexibility +are sort of product flexibility. So, in + + align:start position:0% +are sort of product flexibility. So, in + + + align:start position:0% +are sort of product flexibility. So, in +our case, it's going to be geometry + + align:start position:0% +our case, it's going to be geometry + + + align:start position:0% +our case, it's going to be geometry +flexibility, geometry and material + + align:start position:0% +flexibility, geometry and material + + + align:start position:0% +flexibility, geometry and material +flexibility. Um and the other would be + + align:start position:0% +flexibility. Um and the other would be + + + align:start position:0% +flexibility. Um and the other would be +sort of quantity flexibility, ability to + + align:start position:0% +sort of quantity flexibility, ability to + + + align:start position:0% +sort of quantity flexibility, ability to +um uh vary the capacity or output of + + align:start position:0% +um uh vary the capacity or output of + + + align:start position:0% +um uh vary the capacity or output of +something without having quite a big + + align:start position:0% +something without having quite a big + + + align:start position:0% +something without having quite a big +cost variances. But let's do the first + + align:start position:0% +cost variances. But let's do the first + + + align:start position:0% +cost variances. But let's do the first +one. We won't get into that second one. + + align:start position:0% +one. We won't get into that second one. + + + align:start position:0% +one. We won't get into that second one. +for flexibility of this process to work + + align:start position:0% +for flexibility of this process to work + + + align:start position:0% +for flexibility of this process to work +with different materials and different + + align:start position:0% +with different materials and different + + + align:start position:0% +with different materials and different +shapes. Obviously, the the the extreme + + align:start position:0% +shapes. Obviously, the the the extreme + + + align:start position:0% +shapes. Obviously, the the the extreme +example of flexibility is every part's + + align:start position:0% +example of flexibility is every part's + + + align:start position:0% +example of flexibility is every part's +different and and there's no every + + align:start position:0% +different and and there's no every + + + align:start position:0% +different and and there's no every +part's different and the setup time is + + align:start position:0% +part's different and the setup time is + + + align:start position:0% +part's different and the setup time is +zero. Okay? So mass production + + align:start position:0% +zero. Okay? So mass production + + + align:start position:0% +zero. Okay? So mass production +rates, mass production cost savings, but + + align:start position:0% +rates, mass production cost savings, but + + + align:start position:0% +rates, mass production cost savings, but +custom + + align:start position:0% +custom + + + align:start position:0% +custom +uh custom uh part capability somewhere + + align:start position:0% +uh custom uh part capability somewhere + + + align:start position:0% +uh custom uh part capability somewhere +these all lie somewhere in between + + align:start position:0% +these all lie somewhere in between + + + align:start position:0% +these all lie somewhere in between +there. But if I look at this broadly, + + align:start position:0% +there. But if I look at this broadly, + + + align:start position:0% +there. But if I look at this broadly, +what do you think is the most + + align:start position:0% +what do you think is the most + + + align:start position:0% +what do you think is the most +flexible or what what most flexible or + + align:start position:0% +flexible or what what most flexible or + + + align:start position:0% +flexible or what what most flexible or +more flexible? If I look at the + + align:start position:0% +more flexible? If I look at the + + + align:start position:0% +more flexible? If I look at the +taxonomy, what area would you look at + + align:start position:0% +taxonomy, what area would you look at + + + align:start position:0% +taxonomy, what area would you look at +for for high flexibility? + + align:start position:0% + + + + align:start position:0% + +serial processes and why + + align:start position:0% +serial processes and why + + + align:start position:0% +serial processes and why +I + + align:start position:0% + + + + align:start position:0% + +guess I guess it gives you more + + align:start position:0% +guess I guess it gives you more + + + align:start position:0% +guess I guess it gives you more +flexibility in + + align:start position:0% +flexibility in + + + align:start position:0% +flexibility in +terms I guess feature by feature and + + align:start position:0% +terms I guess feature by feature and + + + align:start position:0% +terms I guess feature by feature and +also part by part. Yeah, I mean exactly. + + align:start position:0% +also part by part. Yeah, I mean exactly. + + + align:start position:0% +also part by part. Yeah, I mean exactly. +I mean think think of again the the + + align:start position:0% +I mean think think of again the the + + + align:start position:0% +I mean think think of again the the +ubiquous example is a uh um I'm trying + + align:start position:0% +ubiquous example is a uh um I'm trying + + + align:start position:0% +ubiquous example is a uh um I'm trying +to think of + + align:start position:0% +to think of + + + align:start position:0% +to think of +of some + + align:start position:0% +of some + + + align:start position:0% +of some +consumer oriented parts of this but um I + + align:start position:0% +consumer oriented parts of this but um I + + + align:start position:0% +consumer oriented parts of this but um I +mean I'm not coming up with them but + + align:start position:0% +mean I'm not coming up with them but + + + align:start position:0% +mean I'm not coming up with them but +yeah a machine tool let's say you know + + align:start position:0% +yeah a machine tool let's say you know + + + align:start position:0% +yeah a machine tool let's say you know +take a machine tool with an endmill and + + align:start position:0% +take a machine tool with an endmill and + + + align:start position:0% +take a machine tool with an endmill and +it can write your name in a piece of + + align:start position:0% +it can write your name in a piece of + + + align:start position:0% +it can write your name in a piece of +plastic + + align:start position:0% +plastic + + + align:start position:0% +plastic +right there's no once I programmed your + + align:start position:0% +right there's no once I programmed your + + + align:start position:0% +right there's no once I programmed your +name in there and then your name and + + align:start position:0% +name in there and then your name and + + + align:start position:0% +name in there and then your name and +then your name and you know there's + + align:start position:0% +then your name and you know there's + + + align:start position:0% +then your name and you know there's +absolutely no overhead to me switching + + align:start position:0% +absolutely no overhead to me switching + + + align:start position:0% +absolutely no overhead to me switching +because all I have to change is the + + align:start position:0% +because all I have to change is the + + + align:start position:0% +because all I have to change is the +trajectory of the tool and that nowadays + + align:start position:0% +trajectory of the tool and that nowadays + + + align:start position:0% +trajectory of the tool and that nowadays +with CNC control that's a zero cost + + align:start position:0% +with CNC control that's a zero cost + + + align:start position:0% +with CNC control that's a zero cost +changeover. There's a minimal cost in + + align:start position:0% +changeover. There's a minimal cost in + + + align:start position:0% +changeover. There's a minimal cost in +creating the programs and for simple + + align:start position:0% +creating the programs and for simple + + + align:start position:0% +creating the programs and for simple +things like that. So yeah, obviously + + align:start position:0% +things like that. So yeah, obviously + + + align:start position:0% +things like that. So yeah, obviously +something that is purely + + align:start position:0% +something that is purely + + + align:start position:0% +something that is purely +serial makes a big difference. And I'm + + align:start position:0% +serial makes a big difference. And I'm + + + align:start position:0% +serial makes a big difference. And I'm +going to add one other thing because I + + align:start position:0% +going to add one other thing because I + + + align:start position:0% +going to add one other thing because I +if if I hurry up, I'll get at least to + + align:start position:0% +if if I hurry up, I'll get at least to + + + align:start position:0% +if if I hurry up, I'll get at least to +mention + + align:start position:0% +mention + + + align:start position:0% +mention +this. I'll make the case that cutting + + align:start position:0% +this. I'll make the case that cutting + + + align:start position:0% +this. I'll make the case that cutting +metal mechanically + + align:start position:0% +metal mechanically + + + align:start position:0% +metal mechanically +um is is maybe the purest form of + + align:start position:0% +um is is maybe the purest form of + + + align:start position:0% +um is is maybe the purest form of +geometry transformation. pure geometry + + align:start position:0% +geometry transformation. pure geometry + + + align:start position:0% +geometry transformation. pure geometry +transformation with no side + + align:start position:0% +transformation with no side + + + align:start position:0% +transformation with no side +effects. Okay. So that also makes it + + align:start position:0% +effects. Okay. So that also makes it + + + align:start position:0% +effects. Okay. So that also makes it +very flexible in that sense. Uh you know + + align:start position:0% +very flexible in that sense. Uh you know + + + align:start position:0% +very flexible in that sense. Uh you know +it's it's almost as if yeah all I have + + align:start position:0% +it's it's almost as if yeah all I have + + + align:start position:0% +it's it's almost as if yeah all I have +to do is reprogram the trajectory and + + align:start position:0% +to do is reprogram the trajectory and + + + align:start position:0% +to do is reprogram the trajectory and +nothing else changes and everything's + + align:start position:0% +nothing else changes and everything's + + + align:start position:0% +nothing else changes and everything's +fine. Um so we'll we'll start from that + + align:start position:0% +fine. Um so we'll we'll start from that + + + align:start position:0% +fine. Um so we'll we'll start from that +and then we move to to + + align:start position:0% +and then we move to to + + + align:start position:0% +and then we move to to +other other changes here. Um let's go to + + align:start position:0% +other other changes here. Um let's go to + + + align:start position:0% +other other changes here. Um let's go to +uh deformation serial deformation + + align:start position:0% + + + + align:start position:0% + +bending. Okay. Going to bend this + + align:start position:0% +bending. Okay. Going to bend this + + + align:start position:0% +bending. Okay. Going to bend this +three-point bending. + + align:start position:0% +three-point bending. + + + align:start position:0% +three-point bending. +Um I'm calling it serial because most of + + align:start position:0% +Um I'm calling it serial because most of + + + align:start position:0% +Um I'm calling it serial because most of +the action is happening right here. And + + align:start position:0% +the action is happening right here. And + + + align:start position:0% +the action is happening right here. And +I'm not using form tools. You can even + + align:start position:0% +I'm not using form tools. You can even + + + align:start position:0% +I'm not using form tools. You can even +think of this as using knife edge tools + + align:start position:0% +think of this as using knife edge tools + + + align:start position:0% +think of this as using knife edge tools +and I would get sort of this same shape. + + align:start position:0% +and I would get sort of this same shape. + + + align:start position:0% +and I would get sort of this same shape. +And the main thing that determines this + + align:start position:0% +And the main thing that determines this + + + align:start position:0% +And the main thing that determines this +shape, the main thing is how far I push + + align:start position:0% +shape, the main thing is how far I push + + + align:start position:0% +shape, the main thing is how far I push +down in the middle, right? Okay. So, + + align:start position:0% +down in the middle, right? Okay. So, + + + align:start position:0% +down in the middle, right? Okay. So, +that's pretty + + align:start position:0% +that's pretty + + + align:start position:0% +that's pretty +flexible. I mean, if you know, if I want + + align:start position:0% +flexible. I mean, if you know, if I want + + + align:start position:0% +flexible. I mean, if you know, if I want +45 degrees, I just take it down less. If + + align:start position:0% +45 degrees, I just take it down less. If + + + align:start position:0% +45 degrees, I just take it down less. If +I go down farther, it takes down take it + + align:start position:0% +I go down farther, it takes down take it + + + align:start position:0% +I go down farther, it takes down take it +down more. But, as can be shown, and + + align:start position:0% +down more. But, as can be shown, and + + + align:start position:0% +down more. But, as can be shown, and +it's it is in the notes, but we probably + + align:start position:0% +it's it is in the notes, but we probably + + + align:start position:0% +it's it is in the notes, but we probably +won't have time to go through it. As can + + align:start position:0% +won't have time to go through it. As can + + + align:start position:0% +won't have time to go through it. As can +be shown, it makes a huge + + align:start position:0% +be shown, it makes a huge + + + align:start position:0% +be shown, it makes a huge +difference what this material + + align:start position:0% +difference what this material + + + align:start position:0% +difference what this material +is and what the underlying machine + + align:start position:0% +is and what the underlying machine + + + align:start position:0% +is and what the underlying machine +structure looks like. And it also, and + + align:start position:0% +structure looks like. And it also, and + + + align:start position:0% +structure looks like. And it also, and +this really kind of gets us to the next + + align:start position:0% +this really kind of gets us to the next + + + align:start position:0% +this really kind of gets us to the next +the next theme here, it also depends + + align:start position:0% +the next theme here, it also depends + + + align:start position:0% +the next theme here, it also depends +very strongly on the uniformity of this + + align:start position:0% +very strongly on the uniformity of this + + + align:start position:0% +very strongly on the uniformity of this +material. So make the statement that + + align:start position:0% +material. So make the statement that + + + align:start position:0% +material. So make the statement that +that the natural variations out of an + + align:start position:0% +that the natural variations out of an + + + align:start position:0% +that the natural variations out of an +aluminum + + align:start position:0% +aluminum + + + align:start position:0% +aluminum +mill, maybe not the Alcoa Tennessee + + align:start position:0% +mill, maybe not the Alcoa Tennessee + + + align:start position:0% +mill, maybe not the Alcoa Tennessee +mill, but the other ones uh of aluminum + + align:start position:0% +mill, but the other ones uh of aluminum + + + align:start position:0% +mill, but the other ones uh of aluminum +is enough that it can completely + + align:start position:0% +is enough that it can completely + + + align:start position:0% +is enough that it can completely +confound precise control of a process + + align:start position:0% +confound precise control of a process + + + align:start position:0% +confound precise control of a process +like this. The natural variation of a + + align:start position:0% +like this. The natural variation of a + + + align:start position:0% +like this. The natural variation of a +piece of aluminum like this that I'm + + align:start position:0% +piece of aluminum like this that I'm + + + align:start position:0% +piece of aluminum like this that I'm +going to turn just doesn't make any + + align:start position:0% +going to turn just doesn't make any + + + align:start position:0% +going to turn just doesn't make any +difference. Sure, if I put a different + + align:start position:0% +difference. Sure, if I put a different + + + align:start position:0% +difference. Sure, if I put a different +alloy in or I sneak in steel or titanium + + align:start position:0% +alloy in or I sneak in steel or titanium + + + align:start position:0% +alloy in or I sneak in steel or titanium +instead of aluminum, yeah, that's a + + align:start position:0% +instead of aluminum, yeah, that's a + + + align:start position:0% +instead of aluminum, yeah, that's a +that's a big mess up. But, + + align:start position:0% +that's a big mess up. But, + + + align:start position:0% +that's a big mess up. But, +um, if I just say, well, you know, uh, + + align:start position:0% +um, if I just say, well, you know, uh, + + + align:start position:0% +um, if I just say, well, you know, uh, +here here's a piece of aluminum. We we + + align:start position:0% +here here's a piece of aluminum. We we + + + align:start position:0% +here here's a piece of aluminum. We we +did it in this mill over here and it + + align:start position:0% +did it in this mill over here and it + + + align:start position:0% +did it in this mill over here and it +came out with the + + align:start position:0% +came out with the + + + align:start position:0% +came out with the +following properties. You know, it it's + + align:start position:0% +following properties. You know, it it's + + + align:start position:0% +following properties. You know, it it's +elasticity, it's its yield strength, + + align:start position:0% +elasticity, it's its yield strength, + + + align:start position:0% +elasticity, it's its yield strength, +it's its strain hardening + + align:start position:0% +it's its strain hardening + + + align:start position:0% +it's its strain hardening +characteristics. And then I get + + align:start position:0% +characteristics. And then I get + + + align:start position:0% +characteristics. And then I get +supposedly the same material from a + + align:start position:0% +supposedly the same material from a + + + align:start position:0% +supposedly the same material from a +different mill, and they're 10% + + align:start position:0% +different mill, and they're 10% + + + align:start position:0% +different mill, and they're 10% +different. Not the elasticity by the + + align:start position:0% +different. Not the elasticity by the + + + align:start position:0% +different. Not the elasticity by the +way, but all the others. Uh 10% + + align:start position:0% +way, but all the others. Uh 10% + + + align:start position:0% +way, but all the others. Uh 10% +different. Huge difference + + align:start position:0% +different. Huge difference + + + align:start position:0% +different. Huge difference +here. Virtually no difference for the + + align:start position:0% +here. Virtually no difference for the + + + align:start position:0% +here. Virtually no difference for the +machining. So there's an inherent + + align:start position:0% +machining. So there's an inherent + + + align:start position:0% +machining. So there's an inherent +sensitivity of the processes to that. + + align:start position:0% +sensitivity of the processes to that. + + + align:start position:0% +sensitivity of the processes to that. +So if I look just at this purely serial + + align:start position:0% +So if I look just at this purely serial + + + align:start position:0% +So if I look just at this purely serial +parallel thing, yeah, serial is better + + align:start position:0% +parallel thing, yeah, serial is better + + + align:start position:0% +parallel thing, yeah, serial is better +than + + align:start position:0% +than + + + align:start position:0% +than +parallel. I think we can show in general + + align:start position:0% +parallel. I think we can show in general + + + align:start position:0% +parallel. I think we can show in general +that removal tends to be the least + + align:start position:0% +that removal tends to be the least + + + align:start position:0% +that removal tends to be the least +sensitive to material properties, tends + + align:start position:0% +sensitive to material properties, tends + + + align:start position:0% +sensitive to material properties, tends +to be the least sensitive to all these + + align:start position:0% +to be the least sensitive to all these + + + align:start position:0% +to be the least sensitive to all these +things. So, you know, serial removal + + align:start position:0% +things. So, you know, serial removal + + + align:start position:0% +things. So, you know, serial removal +kind of wins in most cases in terms of + + align:start position:0% +kind of wins in most cases in terms of + + + align:start position:0% +kind of wins in most cases in terms of +flexibility. + + align:start position:0% +flexibility. + + + align:start position:0% +flexibility. +Um, deformation is generally a killer in + + align:start position:0% +Um, deformation is generally a killer in + + + align:start position:0% +Um, deformation is generally a killer in +terms of flexibility for these regions + + align:start position:0% +terms of flexibility for these regions + + + align:start position:0% +terms of flexibility for these regions +that we've talked about. And, uh, in + + align:start position:0% +that we've talked about. And, uh, in + + + align:start position:0% +that we've talked about. And, uh, in +many cases, well, certainly anything + + align:start position:0% +many cases, well, certainly anything + + + align:start position:0% +many cases, well, certainly anything +that involves a uh, parallel energy + + align:start position:0% +that involves a uh, parallel energy + + + align:start position:0% +that involves a uh, parallel energy +exchange sort of starts off behind the + + align:start position:0% +exchange sort of starts off behind the + + + align:start position:0% +exchange sort of starts off behind the +eightball with respect to flexibility. + + align:start position:0% +eightball with respect to flexibility. + + + align:start position:0% +eightball with respect to flexibility. +Simon, what about the chemical vapor + + align:start position:0% +Simon, what about the chemical vapor + + + align:start position:0% +Simon, what about the chemical vapor +deposition? I mean, they throw in all + + align:start position:0% +deposition? I mean, they throw in all + + + align:start position:0% +deposition? I mean, they throw in all +sorts of parts and they come out with + + align:start position:0% +sorts of parts and they come out with + + + align:start position:0% +sorts of parts and they come out with +the the coating and I mean there is no + + align:start position:0% +the the coating and I mean there is no + + + align:start position:0% +the the coating and I mean there is no +dependency on that's a that's a very + + align:start position:0% +dependency on that's a that's a very + + + align:start position:0% +dependency on that's a that's a very +good point that's a that's a really good + + align:start position:0% +good point that's a that's a really good + + + align:start position:0% +good point that's a that's a really good +point and I think uh I'm glad you raised + + align:start position:0% +point and I think uh I'm glad you raised + + + align:start position:0% +point and I think uh I'm glad you raised +that uh I hadn't thought about that but + + align:start position:0% +that uh I hadn't thought about that but + + + align:start position:0% +that uh I hadn't thought about that but +um a process like this some of these + + align:start position:0% +um a process like this some of these + + + align:start position:0% +um a process like this some of these +addition processes any sort of a plating + + align:start position:0% +addition processes any sort of a plating + + + align:start position:0% +addition processes any sort of a plating +or coating process um where you put + + align:start position:0% +or coating process um where you put + + + align:start position:0% +or coating process um where you put +stuff into a liquid or or vapor + + align:start position:0% +stuff into a liquid or or vapor + + + align:start position:0% +stuff into a liquid or or vapor +uh bath Um, yeah, it doesn't care about + + align:start position:0% +uh bath Um, yeah, it doesn't care about + + + align:start position:0% +uh bath Um, yeah, it doesn't care about +the shape, does it? In I mean, it it at + + align:start position:0% +the shape, does it? In I mean, it it at + + + align:start position:0% +the shape, does it? In I mean, it it at +a microscopic level it might, but yeah, + + align:start position:0% +a microscopic level it might, but yeah, + + + align:start position:0% +a microscopic level it might, but yeah, +it doesn't. That's a good point. So, in + + align:start position:0% +it doesn't. That's a good point. So, in + + + align:start position:0% +it doesn't. That's a good point. So, in +terms of geometry, + + align:start position:0% +terms of geometry, + + + align:start position:0% +terms of geometry, +um, which is, you know, there's the + + align:start position:0% +um, which is, you know, there's the + + + align:start position:0% +um, which is, you know, there's the +underlying geometry of the substrate + + align:start position:0% +underlying geometry of the substrate + + + align:start position:0% +underlying geometry of the substrate +plus whatever thickness you add, um, to + + align:start position:0% +plus whatever thickness you add, um, to + + + align:start position:0% +plus whatever thickness you add, um, to +my knowledge, if I have a big big piece + + align:start position:0% +my knowledge, if I have a big big piece + + + align:start position:0% +my knowledge, if I have a big big piece +over here and right next to it a little + + align:start position:0% +over here and right next to it a little + + + align:start position:0% +over here and right next to it a little +piece over here, another one over here, + + align:start position:0% +piece over here, another one over here, + + + align:start position:0% +piece over here, another one over here, +they're independent of each other, so + + align:start position:0% +they're independent of each other, so + + + align:start position:0% +they're independent of each other, so +they all deposit at the same rate unless + + align:start position:0% +they all deposit at the same rate unless + + + align:start position:0% +they all deposit at the same rate unless +you do something really dumb. Yeah, it's + + align:start position:0% +you do something really dumb. Yeah, it's + + + align:start position:0% +you do something really dumb. Yeah, it's +a good point. Good point. I don't know + + align:start position:0% +a good point. Good point. I don't know + + + align:start position:0% +a good point. Good point. I don't know +how to I don't know how to pull that + + align:start position:0% +how to I don't know how to pull that + + + align:start position:0% +how to I don't know how to pull that +out. But uh in in that + + align:start position:0% +out. But uh in in that + + + align:start position:0% +out. But uh in in that +sense, well to relate it to what we said + + align:start position:0% +sense, well to relate it to what we said + + + align:start position:0% +sense, well to relate it to what we said +before, the energy + + align:start position:0% +before, the energy + + + align:start position:0% +before, the energy +exchange area is determined by the shape + + align:start position:0% +exchange area is determined by the shape + + + align:start position:0% +exchange area is determined by the shape +of the substrate, not the shape of the + + align:start position:0% +of the substrate, not the shape of the + + + align:start position:0% +of the substrate, not the shape of the +tool. And so in a situation like that, + + align:start position:0% +tool. And so in a situation like that, + + + align:start position:0% +tool. And so in a situation like that, +the shape of the substrate, if it's + + align:start position:0% +the shape of the substrate, if it's + + + align:start position:0% +the shape of the substrate, if it's +right, and I can change it each time I + + align:start position:0% +right, and I can change it each time I + + + align:start position:0% +right, and I can change it each time I +put it in, I get high flexibility with + + align:start position:0% +put it in, I get high flexibility with + + + align:start position:0% +put it in, I get high flexibility with +that. Yeah, good point. Good point. + + align:start position:0% +that. Yeah, good point. Good point. + + + align:start position:0% +that. Yeah, good point. Good point. +have to remember + + align:start position:0% +have to remember + + + align:start position:0% +have to remember +that. Okay, enough enough on the + + align:start position:0% + + + + align:start position:0% + +taxonomy. Okay, now uh the last thing I + + align:start position:0% +taxonomy. Okay, now uh the last thing I + + + align:start position:0% +taxonomy. Okay, now uh the last thing I +want to talk about is um what goes + + align:start position:0% +want to talk about is um what goes + + + align:start position:0% +want to talk about is um what goes +wrong. We've been talking about so far, + + align:start position:0% +wrong. We've been talking about so far, + + + align:start position:0% +wrong. We've been talking about so far, +we've made some reference to it. We've + + align:start position:0% +we've made some reference to it. We've + + + align:start position:0% +we've made some reference to it. We've +been talking about so far is is how to + + align:start position:0% +been talking about so far is is how to + + + align:start position:0% +been talking about so far is is how to +make major changes. you know, I want to + + align:start position:0% +make major changes. you know, I want to + + + align:start position:0% +make major changes. you know, I want to +go from a from uh uh you know, this + + align:start position:0% +go from a from uh uh you know, this + + + align:start position:0% +go from a from uh uh you know, this +diameter down to half that diameter. + + align:start position:0% +diameter down to half that diameter. + + + align:start position:0% +diameter down to half that diameter. +Well, I have to push this in. I have to + + align:start position:0% +Well, I have to push this in. I have to + + + align:start position:0% +Well, I have to push this in. I have to +make chips and and you know, I have to + + align:start position:0% +make chips and and you know, I have to + + + align:start position:0% +make chips and and you know, I have to +push this down so far. But what I want + + align:start position:0% +push this down so far. But what I want + + + align:start position:0% +push this down so far. But what I want +to talk about is why isn't this always + + align:start position:0% +to talk about is why isn't this always + + + align:start position:0% +to talk about is why isn't this always +come out to the to the same angle every + + align:start position:0% +come out to the to the same angle every + + + align:start position:0% +come out to the to the same angle every +time? Why is the the third part out of + + align:start position:0% +time? Why is the the third part out of + + + align:start position:0% +time? Why is the the third part out of +the run of 50 different from the 24th + + align:start position:0% +the run of 50 different from the 24th + + + align:start position:0% +the run of 50 different from the 24th +part? You know, that sort of thing. and + + align:start position:0% +part? You know, that sort of thing. and + + + align:start position:0% +part? You know, that sort of thing. and +why when I when I machine this is it not + + align:start position:0% +why when I when I machine this is it not + + + align:start position:0% +why when I when I machine this is it not +the same diameter + + align:start position:0% +the same diameter + + + align:start position:0% +the same diameter +everywhere. Um, and so it it gets into + + align:start position:0% +everywhere. Um, and so it it gets into + + + align:start position:0% +everywhere. Um, and so it it gets into +looking at um the sources of + + align:start position:0% +looking at um the sources of + + + align:start position:0% +looking at um the sources of +variation. And by by our definition of a + + align:start position:0% +variation. And by by our definition of a + + + align:start position:0% +variation. And by by our definition of a +process parameter, we're going to say, + + align:start position:0% +process parameter, we're going to say, + + + align:start position:0% +process parameter, we're going to say, +well, it it Oops. Oh, don't do + + align:start position:0% +well, it it Oops. Oh, don't do + + + align:start position:0% +well, it it Oops. Oh, don't do +that. I'll say yes. But what did I + + align:start position:0% +that. I'll say yes. But what did I + + + align:start position:0% +that. I'll say yes. But what did I +do? + + align:start position:0% +do? + + + align:start position:0% +do? +Push + + align:start position:0% + + + + align:start position:0% + +by our definition of Oh, I see. by our + + align:start position:0% +by our definition of Oh, I see. by our + + + align:start position:0% +by our definition of Oh, I see. by our +definition of of this it's it's all + + align:start position:0% +definition of of this it's it's all + + + align:start position:0% +definition of of this it's it's all +wrapped + + align:start position:0% + + + + align:start position:0% + +up somehow well in the end it's all it's + + align:start position:0% +up somehow well in the end it's all it's + + + align:start position:0% +up somehow well in the end it's all it's +all wrapped up in this this functional + + align:start position:0% +all wrapped up in this this functional + + + align:start position:0% +all wrapped up in this this functional +relationship but primarily through these + + align:start position:0% +relationship but primarily through these + + + align:start position:0% +relationship but primarily through these +process parameters okay so we're going + + align:start position:0% +process parameters okay so we're going + + + align:start position:0% +process parameters okay so we're going +to use those to try and understand so so + + align:start position:0% +to use those to try and understand so so + + + align:start position:0% +to use those to try and understand so so +let's break down these these process + + align:start position:0% +let's break down these these process + + + align:start position:0% +let's break down these these process +parameters in a little bit more of um a + + align:start position:0% +parameters in a little bit more of um a + + + align:start position:0% +parameters in a little bit more of um a +u a logical fashion + + align:start position:0% +u a logical fashion + + + align:start position:0% +u a logical fashion +um and I'm going to do it in the + + align:start position:0% +um and I'm going to do it in the + + + align:start position:0% +um and I'm going to do it in the +following way with the following + + align:start position:0% +following way with the following + + + align:start position:0% +following way with the following +definitions. First of all, we're going + + align:start position:0% +definitions. First of all, we're going + + + align:start position:0% +definitions. First of all, we're going +to have alphas associated with the + + align:start position:0% +to have alphas associated with the + + + align:start position:0% +to have alphas associated with the +equipment and then we're going to have + + align:start position:0% +equipment and then we're going to have + + + align:start position:0% +equipment and then we're going to have +alphas associate let me go back here + + align:start position:0% +alphas associate let me go back here + + + align:start position:0% +alphas associate let me go back here +actually need my picture. So, we're + + align:start position:0% +actually need my picture. So, we're + + + align:start position:0% +actually need my picture. So, we're +going to have these parameters + + align:start position:0% +going to have these parameters + + + align:start position:0% +going to have these parameters +associated just with the + + align:start position:0% +associated just with the + + + align:start position:0% +associated just with the +equipment. And I think I've already + + align:start position:0% +equipment. And I think I've already + + + align:start position:0% +equipment. And I think I've already +explained why we want to distinguish + + align:start position:0% +explained why we want to distinguish + + + align:start position:0% +explained why we want to distinguish +between the two, you know. So, now we're + + align:start position:0% +between the two, you know. So, now we're + + + align:start position:0% +between the two, you know. So, now we're +talking about properties, variables, + + align:start position:0% +talking about properties, variables, + + + align:start position:0% +talking about properties, variables, +things I can adjust, things that happen + + align:start position:0% +things I can adjust, things that happen + + + align:start position:0% +things I can adjust, things that happen +that are staying with that piece of iron + + align:start position:0% +that are staying with that piece of iron + + + align:start position:0% +that are staying with that piece of iron +that's bolted down to the factory floor. + + align:start position:0% +that's bolted down to the factory floor. + + + align:start position:0% +that's bolted down to the factory floor. +And then a similar set, but + + align:start position:0% +And then a similar set, but + + + align:start position:0% +And then a similar set, but +for the stuff that goes in and out of + + align:start position:0% +for the stuff that goes in and out of + + + align:start position:0% +for the stuff that goes in and out of +the machine or that flows through the + + align:start position:0% +the machine or that flows through the + + + align:start position:0% +the machine or that flows through the +machine, it doesn't go in and out. So, + + align:start position:0% +machine, it doesn't go in and out. So, + + + align:start position:0% +machine, it doesn't go in and out. So, +that's why we distinguish between them. + + align:start position:0% +that's why we distinguish between them. + + + align:start position:0% +that's why we distinguish between them. +So let's just focus uh um I don't know + + align:start position:0% +So let's just focus uh um I don't know + + + align:start position:0% +So let's just focus uh um I don't know +let's focus on the machine on the + + align:start position:0% +let's focus on the machine on the + + + align:start position:0% +let's focus on the machine on the +equipment. If I think of two broad + + align:start position:0% +equipment. If I think of two broad + + + align:start position:0% +equipment. If I think of two broad +classifications of a machine well let's + + align:start position:0% +classifications of a machine well let's + + + align:start position:0% +classifications of a machine well let's +see try this exercise. I think + + align:start position:0% +see try this exercise. I think + + + align:start position:0% +see try this exercise. I think +everybody's familiar with a machine + + align:start position:0% +everybody's familiar with a machine + + + align:start position:0% +everybody's familiar with a machine +tool. I got a simple lathe. It's sitting + + align:start position:0% +tool. I got a simple lathe. It's sitting + + + align:start position:0% +tool. I got a simple lathe. It's sitting +here in front of us. Um and it's not + + align:start position:0% +here in front of us. Um and it's not + + + align:start position:0% +here in front of us. Um and it's not +doing a thing. It's not moving. It's not + + align:start position:0% +doing a thing. It's not moving. It's not + + + align:start position:0% +doing a thing. It's not moving. It's not +even plugged in. + + align:start position:0% +even plugged in. + + + align:start position:0% +even plugged in. +What what alphas what characteristics + + align:start position:0% +What what alphas what characteristics + + + align:start position:0% +What what alphas what characteristics +can you tell me about it just by looking + + align:start position:0% +can you tell me about it just by looking + + + align:start position:0% +can you tell me about it just by looking +at it? It's not + + align:start position:0% +at it? It's not + + + align:start position:0% +at it? It's not +moving. What might you if you were to + + align:start position:0% +moving. What might you if you were to + + + align:start position:0% +moving. What might you if you were to +describe it from an engineering point of + + align:start position:0% +describe it from an engineering point of + + + align:start position:0% +describe it from an engineering point of +view? What are the kinds of things you'd + + align:start position:0% +view? What are the kinds of things you'd + + + align:start position:0% +view? What are the kinds of things you'd +worry about on it? + + align:start position:0% +worry about on it? + + + align:start position:0% +worry about on it? +Stiffness. How stiff is it? Does it + + align:start position:0% +Stiffness. How stiff is it? Does it + + + align:start position:0% +Stiffness. How stiff is it? Does it +deform? + + align:start position:0% +deform? + + + align:start position:0% +deform? +Yeah, that's a that's almost it. That's + + align:start position:0% +Yeah, that's a that's almost it. That's + + + align:start position:0% +Yeah, that's a that's almost it. That's +a good one right there. Stiffness. + + align:start position:0% +a good one right there. Stiffness. + + + align:start position:0% +a good one right there. Stiffness. +Straightness. + + align:start position:0% +Straightness. + + + align:start position:0% +Straightness. +um uh some details of other you know + + align:start position:0% +um uh some details of other you know + + + align:start position:0% +um uh some details of other you know +mechanical characteristics of it. How + + align:start position:0% +mechanical characteristics of it. How + + + align:start position:0% +mechanical characteristics of it. How +about thermal expansion? Yeah, thermal + + align:start position:0% +about thermal expansion? Yeah, thermal + + + align:start position:0% +about thermal expansion? Yeah, thermal +expansion coefficient. Very important + + align:start position:0% +expansion coefficient. Very important + + + align:start position:0% +expansion coefficient. Very important +stuff. All those things that basically + + align:start position:0% +stuff. All those things that basically + + + align:start position:0% +stuff. All those things that basically +go into is is the structure and where + + align:start position:0% +go into is is the structure and where + + + align:start position:0% +go into is is the structure and where +I'm going to direct that energy source + + align:start position:0% +I'm going to direct that energy source + + + align:start position:0% +I'm going to direct that energy source +where I think it's going to be. Okay. Um + + align:start position:0% +where I think it's going to be. Okay. Um + + + align:start position:0% +where I think it's going to be. Okay. Um +now I turn it on. It starts moving and I + + align:start position:0% +now I turn it on. It starts moving and I + + + align:start position:0% +now I turn it on. It starts moving and I +start + + align:start position:0% +start + + + align:start position:0% +start +machining. Forget about the chips and + + align:start position:0% +machining. Forget about the chips and + + + align:start position:0% +machining. Forget about the chips and +all that other stuff, but just the + + align:start position:0% +all that other stuff, but just the + + + align:start position:0% +all that other stuff, but just the +machine itself. What are you gonna What + + align:start position:0% +machine itself. What are you gonna What + + + align:start position:0% +machine itself. What are you gonna What +other characteristics of the machine are + + align:start position:0% +other characteristics of the machine are + + + align:start position:0% +other characteristics of the machine are +you now going to worry about? + + align:start position:0% + + + + align:start position:0% + +The turning speed. Yeah, the turning + + align:start position:0% +The turning speed. Yeah, the turning + + + align:start position:0% +The turning speed. Yeah, the turning +speed. Exactly. The speed. What else? + + align:start position:0% + + + + align:start position:0% + +Accuracy of that rotation. Yeah. + + align:start position:0% +Accuracy of that rotation. Yeah. + + + align:start position:0% +Accuracy of that rotation. Yeah. +Accuracy of the rotation. Yeah. Okay. + + align:start position:0% +Accuracy of the rotation. Yeah. Okay. + + + align:start position:0% +Accuracy of the rotation. Yeah. Okay. +Yep. But now we got the turning speed. + + align:start position:0% +Yep. But now we got the turning speed. + + + align:start position:0% +Yep. But now we got the turning speed. +All right. Now, okay. What's the + + align:start position:0% +All right. Now, okay. What's the + + + align:start position:0% +All right. Now, okay. What's the +difference from the machine's point of + + align:start position:0% +difference from the machine's point of + + + align:start position:0% +difference from the machine's point of +view? If I've got the tool and I'm + + align:start position:0% +view? If I've got the tool and I'm + + + align:start position:0% +view? If I've got the tool and I'm +coming along, I think you guys can see + + align:start position:0% +coming along, I think you guys can see + + + align:start position:0% +coming along, I think you guys can see +this. If I'm coming along like this, + + align:start position:0% +this. If I'm coming along like this, + + + align:start position:0% +this. If I'm coming along like this, +right now I'm characterizing the machine + + align:start position:0% +right now I'm characterizing the machine + + + align:start position:0% +right now I'm characterizing the machine +and now I'm characterizing the machine. + + align:start position:0% +and now I'm characterizing the machine. + + + align:start position:0% +and now I'm characterizing the machine. +I'm I've hit the material and I'm + + align:start position:0% +I'm I've hit the material and I'm + + + align:start position:0% +I'm I've hit the material and I'm +starting to machine. What's the + + align:start position:0% +starting to machine. What's the + + + align:start position:0% +starting to machine. What's the +difference between when I'm here and + + align:start position:0% +difference between when I'm here and + + + align:start position:0% +difference between when I'm here and +when I'm here? + + align:start position:0% + + + + align:start position:0% + +H you skipped something. Go ahead. I + + align:start position:0% +H you skipped something. Go ahead. I + + + align:start position:0% +H you skipped something. Go ahead. I +think Yeah. Yeah. You talked about the + + align:start position:0% +think Yeah. Yeah. You talked about the + + + align:start position:0% +think Yeah. Yeah. You talked about the +speed. So I have a the speed a speed + + align:start position:0% +speed. So I have a the speed a speed + + + align:start position:0% +speed. So I have a the speed a speed +here and I have a rotation speed. But if + + align:start position:0% +here and I have a rotation speed. But if + + + align:start position:0% +here and I have a rotation speed. But if +there's no force like you know there's + + align:start position:0% +there's no force like you know there's + + + align:start position:0% +there's no force like you know there's +no power there's no nothing no nothing + + align:start position:0% +no power there's no nothing no nothing + + + align:start position:0% +no power there's no nothing no nothing +much happening. It's good grammar. Um + + align:start position:0% +much happening. It's good grammar. Um + + + align:start position:0% +much happening. It's good grammar. Um +but if if I come along here all of a + + align:start position:0% +but if if I come along here all of a + + + align:start position:0% +but if if I come along here all of a +sudden the force changes. So as a + + align:start position:0% +sudden the force changes. So as a + + + align:start position:0% +sudden the force changes. So as a +minimum you've got these two sets of + + align:start position:0% +minimum you've got these two sets of + + + align:start position:0% +minimum you've got these two sets of +variables. You've got you know how stiff + + align:start position:0% +variables. You've got you know how stiff + + + align:start position:0% +variables. You've got you know how stiff +is the machine? How does it react to + + align:start position:0% +is the machine? How does it react to + + + align:start position:0% +is the machine? How does it react to +things like forces? um how straight is + + align:start position:0% +things like forces? um how straight is + + + align:start position:0% +things like forces? um how straight is +the machine if I move this way relative + + align:start position:0% +the machine if I move this way relative + + + align:start position:0% +the machine if I move this way relative +to the axis of rotation that's your + + align:start position:0% +to the axis of rotation that's your + + + align:start position:0% +to the axis of rotation that's your +accuracy thing you know is it that way + + align:start position:0% +accuracy thing you know is it that way + + + align:start position:0% +accuracy thing you know is it that way +and those are properties that they're + + align:start position:0% +and those are properties that they're + + + align:start position:0% +and those are properties that they're +not independent of of whether it's + + align:start position:0% +not independent of of whether it's + + + align:start position:0% +not independent of of whether it's +moving or not but you know you kind of + + align:start position:0% +moving or not but you know you kind of + + + align:start position:0% +moving or not but you know you kind of +look at it and you say and it's the + + align:start position:0% +look at it and you say and it's the + + + align:start position:0% +look at it and you say and it's the +basic characteristic of the machine and + + align:start position:0% +basic characteristic of the machine and + + + align:start position:0% +basic characteristic of the machine and +then you've got these transient ones + + align:start position:0% +then you've got these transient ones + + + align:start position:0% +then you've got these transient ones +that are only related to the energy + + align:start position:0% +that are only related to the energy + + + align:start position:0% +that are only related to the energy +exchange so you'd agree that if there's + + align:start position:0% +exchange so you'd agree that if there's + + + align:start position:0% +exchange so you'd agree that if there's +no force there's no energy exchange but + + align:start position:0% +no force there's no energy exchange but + + + align:start position:0% +no force there's no energy exchange but +as soon as I have a force and a velocity + + align:start position:0% +as soon as I have a force and a velocity + + + align:start position:0% +as soon as I have a force and a velocity +I'm putting mechanical power into that + + align:start position:0% +I'm putting mechanical power into that + + + align:start position:0% +I'm putting mechanical power into that +thing and something's going to happen. + + align:start position:0% +thing and something's going to happen. + + + align:start position:0% +thing and something's going to happen. +Okay. So from that we can actually say + + align:start position:0% +Okay. So from that we can actually say + + + align:start position:0% +Okay. So from that we can actually say +okay there are two types of variables. + + align:start position:0% +okay there are two types of variables. + + + align:start position:0% +okay there are two types of variables. +Think of these sort of ones that are + + align:start position:0% +Think of these sort of ones that are + + + align:start position:0% +Think of these sort of ones that are +intrinsic variables that characterize + + align:start position:0% +intrinsic variables that characterize + + + align:start position:0% +intrinsic variables that characterize +the basic properties of the machine. And + + align:start position:0% +the basic properties of the machine. And + + + align:start position:0% +the basic properties of the machine. And +you know if we if we were doing applied + + align:start position:0% +you know if we if we were doing applied + + + align:start position:0% +you know if we if we were doing applied +mechanics we'd say those are the + + align:start position:0% +mechanics we'd say those are the + + + align:start position:0% +mechanics we'd say those are the +constitutive properties of the material + + align:start position:0% +constitutive properties of the material + + + align:start position:0% +constitutive properties of the material +of the material or their constitutive + + align:start position:0% +of the material or their constitutive + + + align:start position:0% +of the material or their constitutive +properties of our machine. And then + + align:start position:0% +properties of our machine. And then + + + align:start position:0% +properties of our machine. And then +there are the energy states, how things + + align:start position:0% +there are the energy states, how things + + + align:start position:0% +there are the energy states, how things +change over time as the as the energy + + align:start position:0% +change over time as the as the energy + + + align:start position:0% +change over time as the as the energy +waxes and wanes and interchanges and + + align:start position:0% +waxes and wanes and interchanges and + + + align:start position:0% +waxes and wanes and interchanges and +things like that. And those are useful + + align:start position:0% +things like that. And those are useful + + + align:start position:0% +things like that. And those are useful +divisions because for example, how + + align:start position:0% +divisions because for example, how + + + align:start position:0% +divisions because for example, how +easily can I change the stiffness of a + + align:start position:0% + + + + align:start position:0% + +machine? Can be done. Could buy a new + + align:start position:0% +machine? Can be done. Could buy a new + + + align:start position:0% +machine? Can be done. Could buy a new +one. I could go in and put in some more + + align:start position:0% +one. I could go in and put in some more + + + align:start position:0% +one. I could go in and put in some more +supports, you know, and that kind of + + align:start position:0% +supports, you know, and that kind of + + + align:start position:0% +supports, you know, and that kind of +stuff. Or I can take some away and make + + align:start position:0% +stuff. Or I can take some away and make + + + align:start position:0% +stuff. Or I can take some away and make +it less stiff. + + align:start position:0% +it less stiff. + + + align:start position:0% +it less stiff. +um kind of hard. Yeah. Depends a lot on + + align:start position:0% +um kind of hard. Yeah. Depends a lot on + + + align:start position:0% +um kind of hard. Yeah. Depends a lot on +where I + + align:start position:0% +where I + + + align:start position:0% +where I +have I have like a mill. I can take the + + align:start position:0% +have I have like a mill. I can take the + + + align:start position:0% +have I have like a mill. I can take the +table out very far and reduce the + + align:start position:0% +table out very far and reduce the + + + align:start position:0% +table out very far and reduce the +stiffness. Oh yeah. Yeah. Yeah. Yeah. + + align:start position:0% +stiffness. Oh yeah. Yeah. Yeah. Yeah. + + + align:start position:0% +stiffness. Oh yeah. Yeah. Yeah. Yeah. +Within right with stiffness is not a + + align:start position:0% +Within right with stiffness is not a + + + align:start position:0% +Within right with stiffness is not a +single quantity. You're right. I can + + align:start position:0% +single quantity. You're right. I can + + + align:start position:0% +single quantity. You're right. I can +find stiffer regions and less stiff + + align:start position:0% +find stiffer regions and less stiff + + + align:start position:0% +find stiffer regions and less stiff +regions. But I guess what I'm saying is + + align:start position:0% +regions. But I guess what I'm saying is + + + align:start position:0% +regions. But I guess what I'm saying is +if you need to elevate the stiffness of + + align:start position:0% +if you need to elevate the stiffness of + + + align:start position:0% +if you need to elevate the stiffness of +the whole, you know, there's no + + align:start position:0% +the whole, you know, there's no + + + align:start position:0% +the whole, you know, there's no +acceptable spot in it. What do you do? + + align:start position:0% +acceptable spot in it. What do you do? + + + align:start position:0% +acceptable spot in it. What do you do? +You know, you have to go you have to + + align:start position:0% +You know, you have to go you have to + + + align:start position:0% +You know, you have to go you have to +change the iron. I have to go in and + + align:start position:0% +change the iron. I have to go in and + + + align:start position:0% +change the iron. I have to go in and +make a a change. It's not something that + + align:start position:0% +make a a change. It's not something that + + + align:start position:0% +make a a change. It's not something that +we would call really at this case a + + align:start position:0% +we would call really at this case a + + + align:start position:0% +we would call really at this case a +control + + align:start position:0% +control + + + align:start position:0% +control +variable. On the other hand, if I need + + align:start position:0% +variable. On the other hand, if I need + + + align:start position:0% +variable. On the other hand, if I need +to change + + align:start position:0% +to change + + + align:start position:0% +to change +the speed at which I'm + + align:start position:0% +the speed at which I'm + + + align:start position:0% +the speed at which I'm +cutting, just change the speed at which + + align:start position:0% +cutting, just change the speed at which + + + align:start position:0% +cutting, just change the speed at which +I'm cutting and it changes. Okay. So, uh + + align:start position:0% +I'm cutting and it changes. Okay. So, uh + + + align:start position:0% +I'm cutting and it changes. Okay. So, uh +again, there's a there's an important + + align:start position:0% +again, there's a there's an important + + + align:start position:0% +again, there's a there's an important +distinction between uh between those two + + align:start position:0% +distinction between uh between those two + + + align:start position:0% +distinction between uh between those two +and our ability to know them as well as + + align:start position:0% +and our ability to know them as well as + + + align:start position:0% +and our ability to know them as well as +to control them is is vastly different. + + align:start position:0% +to control them is is vastly different. + + + align:start position:0% +to control them is is vastly different. +Now, the same thing holds true for this + + align:start position:0% +Now, the same thing holds true for this + + + align:start position:0% +Now, the same thing holds true for this +this this uh piece of piece of sheet + + align:start position:0% +this this uh piece of piece of sheet + + + align:start position:0% +this this uh piece of piece of sheet +metal, you know, in its undeformed + + align:start position:0% +metal, you know, in its undeformed + + + align:start position:0% +metal, you know, in its undeformed +state. This is really hard stuff. It's + + align:start position:0% +state. This is really hard stuff. It's + + + align:start position:0% +state. This is really hard stuff. It's +like butter. Okay. Um, how would you + + align:start position:0% +like butter. Okay. Um, how would you + + + align:start position:0% +like butter. Okay. Um, how would you +characterize if I just put this piece of + + align:start position:0% +characterize if I just put this piece of + + + align:start position:0% +characterize if I just put this piece of +sheet metal down here? How would you + + align:start position:0% +sheet metal down here? How would you + + + align:start position:0% +sheet metal down here? How would you +characterize it? + + align:start position:0% + + + + align:start position:0% + +Yeah, please. Yield strength. Yield + + align:start position:0% +Yeah, please. Yield strength. Yield + + + align:start position:0% +Yeah, please. Yield strength. Yield +strength extremely important. Anything + + align:start position:0% +strength extremely important. Anything + + + align:start position:0% +strength extremely important. Anything +else? + + align:start position:0% + + + + align:start position:0% + +Go ahead, Adam. Elasticity. Yeah, + + align:start position:0% +Go ahead, Adam. Elasticity. Yeah, + + + align:start position:0% +Go ahead, Adam. Elasticity. Yeah, +elasticity. Thickness. Thickness. + + align:start position:0% +elasticity. Thickness. Thickness. + + + align:start position:0% +elasticity. Thickness. Thickness. +Temperature. + + align:start position:0% +Temperature. + + + align:start position:0% +Temperature. +Temperature. Actually, that's not I'm + + align:start position:0% +Temperature. Actually, that's not I'm + + + align:start position:0% +Temperature. Actually, that's not I'm +I'm going to disagree with you on that. + + align:start position:0% +I'm going to disagree with you on that. + + + align:start position:0% +I'm going to disagree with you on that. +No. Why does temperature matter? Because + + align:start position:0% +No. Why does temperature matter? Because + + + align:start position:0% +No. Why does temperature matter? Because +it changes the dimension. Okay. So that + + align:start position:0% +it changes the dimension. Okay. So that + + + align:start position:0% +it changes the dimension. Okay. So that +so there's a thermal expansion + + align:start position:0% +so there's a thermal expansion + + + align:start position:0% +so there's a thermal expansion +characteristic on this. Okay, that's + + align:start position:0% +characteristic on this. Okay, that's + + + align:start position:0% +characteristic on this. Okay, that's +what I that's very important point for + + align:start position:0% +what I that's very important point for + + + align:start position:0% +what I that's very important point for +the when I say characterizing this you + + align:start position:0% +the when I say characterizing this you + + + align:start position:0% +the when I say characterizing this you +don't characterize it by its + + align:start position:0% +don't characterize it by its + + + align:start position:0% +don't characterize it by its +temperature. You characterize it by its + + align:start position:0% +temperature. You characterize it by its + + + align:start position:0% +temperature. You characterize it by its +reaction to + + align:start position:0% +reaction to + + + align:start position:0% +reaction to +temperature. I don't characterize it by + + align:start position:0% +temperature. I don't characterize it by + + + align:start position:0% +temperature. I don't characterize it by +its stress or strain. I characterize it + + align:start position:0% +its stress or strain. I characterize it + + + align:start position:0% +its stress or strain. I characterize it +by its reaction to stress or strain. So + + align:start position:0% +by its reaction to stress or strain. So + + + align:start position:0% +by its reaction to stress or strain. So +those are all again very clearly for a + + align:start position:0% +those are all again very clearly for a + + + align:start position:0% +those are all again very clearly for a +piece of metal it is constitutive + + align:start position:0% +piece of metal it is constitutive + + + align:start position:0% +piece of metal it is constitutive +properties and we could also worry about + + align:start position:0% +properties and we could also worry about + + + align:start position:0% +properties and we could also worry about +its chemical reactivity and all this + + align:start position:0% +its chemical reactivity and all this + + + align:start position:0% +its chemical reactivity and all this +other stuff but it's inherent + + align:start position:0% +other stuff but it's inherent + + + align:start position:0% +other stuff but it's inherent +characteristic of it which describes how + + align:start position:0% +characteristic of it which describes how + + + align:start position:0% +characteristic of it which describes how +it reacts + + align:start position:0% +it reacts + + + align:start position:0% +it reacts +to impinging energy. Okay. So the + + align:start position:0% +to impinging energy. Okay. So the + + + align:start position:0% +to impinging energy. Okay. So the +mechanical energy I put in + + align:start position:0% +mechanical energy I put in + + + align:start position:0% +mechanical energy I put in +here combined with its elasticity, its + + align:start position:0% +here combined with its elasticity, its + + + align:start position:0% +here combined with its elasticity, its +yield stress and other things determines + + align:start position:0% +yield stress and other things determines + + + align:start position:0% +yield stress and other things determines +how far it bends. Okay. And how it + + align:start position:0% +how far it bends. Okay. And how it + + + align:start position:0% +how far it bends. Okay. And how it +bends. So we distinguish between the + + align:start position:0% +bends. So we distinguish between the + + + align:start position:0% +bends. So we distinguish between the +two. Again, um so when this when this + + align:start position:0% +two. Again, um so when this when this + + + align:start position:0% +two. Again, um so when this when this +baby's sitting here waiting to be bent, + + align:start position:0% +baby's sitting here waiting to be bent, + + + align:start position:0% +baby's sitting here waiting to be bent, +it's got its constituive properties. As + + align:start position:0% +it's got its constituive properties. As + + + align:start position:0% +it's got its constituive properties. As +it's being bent, it's now bearing + + align:start position:0% +it's being bent, it's now bearing + + + align:start position:0% +it's being bent, it's now bearing +uh uh external loads uh and + + align:start position:0% +uh uh external loads uh and + + + align:start position:0% +uh uh external loads uh and +displacements. It's stressing and + + align:start position:0% +displacements. It's stressing and + + + align:start position:0% +displacements. It's stressing and +straining. Um and uh that's a + + align:start position:0% +straining. Um and uh that's a + + + align:start position:0% +straining. Um and uh that's a +transangent state, right? It's an energy + + align:start position:0% +transangent state, right? It's an energy + + + align:start position:0% +transangent state, right? It's an energy +transfer. And those are two different + + align:start position:0% +transfer. And those are two different + + + align:start position:0% +transfer. And those are two different +things. They're both important to + + align:start position:0% +things. They're both important to + + + align:start position:0% +things. They're both important to +determining what comes out here because, + + align:start position:0% +determining what comes out here because, + + + align:start position:0% +determining what comes out here because, +you know, if I said, "Okay, go back to + + align:start position:0% +you know, if I said, "Okay, go back to + + + align:start position:0% +you know, if I said, "Okay, go back to +your computers or your textbooks and + + align:start position:0% +your computers or your textbooks and + + + align:start position:0% +your computers or your textbooks and +give me an analysis of how what it takes + + align:start position:0% +give me an analysis of how what it takes + + + align:start position:0% +give me an analysis of how what it takes +to get this shape." You're going to need + + align:start position:0% +to get this shape." You're going to need + + + align:start position:0% +to get this shape." You're going to need +to know the characteristics of the + + align:start position:0% +to know the characteristics of the + + + align:start position:0% +to know the characteristics of the +material, stiffness, yield, stress, that + + align:start position:0% +material, stiffness, yield, stress, that + + + align:start position:0% +material, stiffness, yield, stress, that +sort of thing. You're also going to need + + align:start position:0% +sort of thing. You're also going to need + + + align:start position:0% +sort of thing. You're also going to need +to know what forces and displacements I + + align:start position:0% +to know what forces and displacements I + + + align:start position:0% +to know what forces and displacements I +put into it, which will tell you what + + align:start position:0% +put into it, which will tell you what + + + align:start position:0% +put into it, which will tell you what +happened internally to this thing. What + + align:start position:0% +happened internally to this thing. What + + + align:start position:0% +happened internally to this thing. What +stresses and strains did it did it have? + + align:start position:0% +stresses and strains did it did it have? + + + align:start position:0% +stresses and strains did it did it have? +Okay. Same thing with this + + align:start position:0% +Okay. Same thing with this + + + align:start position:0% +Okay. Same thing with this +You know, I needed to know what the the + + align:start position:0% +You know, I needed to know what the the + + + align:start position:0% +You know, I needed to know what the the +characteristic of the polymer was. How + + align:start position:0% +characteristic of the polymer was. How + + + align:start position:0% +characteristic of the polymer was. How +did it react to temperature? What was it + + align:start position:0% +did it react to temperature? What was it + + + align:start position:0% +did it react to temperature? What was it +its viscosity with temperature? What's + + align:start position:0% +its viscosity with temperature? What's + + + align:start position:0% +its viscosity with temperature? What's +its heat transfer characteristics? And + + align:start position:0% +its heat transfer characteristics? And + + + align:start position:0% +its heat transfer characteristics? And +then I needed to know what temperature + + align:start position:0% +then I needed to know what temperature + + + align:start position:0% +then I needed to know what temperature +it was, what pressure it saw, and what + + align:start position:0% +it was, what pressure it saw, and what + + + align:start position:0% +it was, what pressure it saw, and what +the heat transfer characteristics of the + + align:start position:0% +the heat transfer characteristics of the + + + align:start position:0% +the heat transfer characteristics of the +mold were. Okay. So, what does this all + + align:start position:0% +mold were. Okay. So, what does this all + + + align:start position:0% +mold were. Okay. So, what does this all +lead + + align:start position:0% +lead + + + align:start position:0% +lead +to? These four babies. Two two major + + align:start position:0% +to? These four babies. Two two major + + + align:start position:0% +to? These four babies. Two two major +things. States and properties. Okay. + + align:start position:0% +things. States and properties. Okay. + + + align:start position:0% +things. States and properties. Okay. +States and properties. energy + + align:start position:0% +States and properties. energy + + + align:start position:0% +States and properties. energy +states, transient things, things that + + align:start position:0% +states, transient things, things that + + + align:start position:0% +states, transient things, things that +don't hang around, things that are just + + align:start position:0% +don't hang around, things that are just + + + align:start position:0% +don't hang around, things that are just +there to accomplish what we wanted to + + align:start position:0% +there to accomplish what we wanted to + + + align:start position:0% +there to accomplish what we wanted to +accomplish and then they go away and + + align:start position:0% +accomplish and then they go away and + + + align:start position:0% +accomplish and then they go away and +properties which if you will, we can + + align:start position:0% +properties which if you will, we can + + + align:start position:0% +properties which if you will, we can +change them, but they kind of are there + + align:start position:0% +change them, but they kind of are there + + + align:start position:0% +change them, but they kind of are there +when we begin and they're still there + + align:start position:0% +when we begin and they're still there + + + align:start position:0% +when we begin and they're still there +when we're done. + + align:start position:0% +when we're done. + + + align:start position:0% +when we're done. +Okay? Um, and are are more inherent to + + align:start position:0% +Okay? Um, and are are more inherent to + + + align:start position:0% +Okay? Um, and are are more inherent to +either the the the equipment itself, the + + align:start position:0% +either the the the equipment itself, the + + + align:start position:0% +either the the the equipment itself, the +m essentially the material of the + + align:start position:0% +m essentially the material of the + + + align:start position:0% +m essentially the material of the +equipment or inherent to the to the + + align:start position:0% +equipment or inherent to the to the + + + align:start position:0% +equipment or inherent to the to the +material itself. + + align:start position:0% +material itself. + + + align:start position:0% +material itself. +Um so when we talk about energy states + + align:start position:0% +Um so when we talk about energy states + + + align:start position:0% +Um so when we talk about energy states +this one is is can be made much more + + align:start position:0% +this one is is can be made much more + + + align:start position:0% +this one is is can be made much more +precise than we have time to do here and + + align:start position:0% +precise than we have time to do here and + + + align:start position:0% +precise than we have time to do here and +uh those of us who who are students of + + align:start position:0% +uh those of us who who are students of + + + align:start position:0% +uh those of us who who are students of +uh system dynamics in the mechanical in + + align:start position:0% +uh system dynamics in the mechanical in + + + align:start position:0% +uh system dynamics in the mechanical in +the in the not in the in the um Sturman + + align:start position:0% +the in the not in the in the um Sturman + + + align:start position:0% +the in the not in the in the um Sturman +sense but in the uh in the painter and + + align:start position:0% +sense but in the uh in the painter and + + + align:start position:0% +sense but in the uh in the painter and +and Richardson sense of uh system + + align:start position:0% +and Richardson sense of uh system + + + align:start position:0% +and Richardson sense of uh system +dynamics. uh understand that you can + + align:start position:0% +dynamics. uh understand that you can + + + align:start position:0% +dynamics. uh understand that you can +really do a good job of describing the + + align:start position:0% +really do a good job of describing the + + + align:start position:0% +really do a good job of describing the +world by simply talking about uh energy + + align:start position:0% +world by simply talking about uh energy + + + align:start position:0% +world by simply talking about uh energy +or power and constitutive relationships + + align:start position:0% +or power and constitutive relationships + + + align:start position:0% +or power and constitutive relationships +and you can model any thing as how it + + align:start position:0% +and you can model any thing as how it + + + align:start position:0% +and you can model any thing as how it +reacts to these to these things. So + + align:start position:0% +reacts to these to these things. So + + + align:start position:0% +reacts to these to these things. So +that's really what we've done here. The + + align:start position:0% +that's really what we've done here. The + + + align:start position:0% +that's really what we've done here. The +equipment provides or absorbs either + + align:start position:0% +equipment provides or absorbs either + + + align:start position:0% +equipment provides or absorbs either +either provides or absorbs some form of + + align:start position:0% +either provides or absorbs some form of + + + align:start position:0% +either provides or absorbs some form of +energy, force, velocity, pressure, flow, + + align:start position:0% +energy, force, velocity, pressure, flow, + + + align:start position:0% +energy, force, velocity, pressure, flow, +force displacement, + + align:start position:0% +force displacement, + + + align:start position:0% +force displacement, +uh that sort of thing, voltage, current, + + align:start position:0% +uh that sort of thing, voltage, current, + + + align:start position:0% +uh that sort of thing, voltage, current, +heat transfer, u heat flow. Um, and + + align:start position:0% +heat transfer, u heat flow. Um, and + + + align:start position:0% +heat transfer, u heat flow. Um, and +those are the things that + + align:start position:0% +those are the things that + + + align:start position:0% +those are the things that +determine specifically what's what what + + align:start position:0% +determine specifically what's what what + + + align:start position:0% +determine specifically what's what what +happens in the interaction between these + + align:start position:0% +happens in the interaction between these + + + align:start position:0% +happens in the interaction between these +two. And then the properties which is + + align:start position:0% +two. And then the properties which is + + + align:start position:0% +two. And then the properties which is +sort of like what's going to happen when + + align:start position:0% +sort of like what's going to happen when + + + align:start position:0% +sort of like what's going to happen when +that energy is transferred are all these + + align:start position:0% +that energy is transferred are all these + + + align:start position:0% +that energy is transferred are all these +things we've talked about modulus of + + align:start position:0% +things we've talked about modulus of + + + align:start position:0% +things we've talked about modulus of +elasticity plastic flow properties + + align:start position:0% +elasticity plastic flow properties + + + align:start position:0% +elasticity plastic flow properties +viscosity sort of almost the same thing + + align:start position:0% +viscosity sort of almost the same thing + + + align:start position:0% +viscosity sort of almost the same thing +resistance inductance capacitance + + align:start position:0% +resistance inductance capacitance + + + align:start position:0% +resistance inductance capacitance +chemical reactivity heat transfer + + align:start position:0% +chemical reactivity heat transfer + + + align:start position:0% +chemical reactivity heat transfer +coefficients okay thermal diffusivities + + align:start position:0% +coefficients okay thermal diffusivities + + + align:start position:0% +coefficients okay thermal diffusivities +um intensive constituive properties plus + + align:start position:0% +um intensive constituive properties plus + + + align:start position:0% +um intensive constituive properties plus +because someone mentioned this before + + align:start position:0% +because someone mentioned this before + + + align:start position:0% +because someone mentioned this before +someone mentioned thickness of this + + align:start position:0% +someone mentioned thickness of this + + + align:start position:0% +someone mentioned thickness of this +extremely important so are the other two + + align:start position:0% +extremely important so are the other two + + + align:start position:0% +extremely important so are the other two +dimensions these dimensions are + + align:start position:0% +dimensions these dimensions are + + + align:start position:0% +dimensions these dimensions are +important and these dimensions are + + align:start position:0% +important and these dimensions are + + + align:start position:0% +important and these dimensions are +important and so it turns out the the + + align:start position:0% +important and so it turns out the the + + + align:start position:0% +important and so it turns out the the +object of our all our affection is + + align:start position:0% +object of our all our affection is + + + align:start position:0% +object of our all our affection is +actually + + align:start position:0% +actually + + + align:start position:0% +actually +um the geometry in the end right so it's + + align:start position:0% +um the geometry in the end right so it's + + + align:start position:0% +um the geometry in the end right so it's +a sort of an extensive property of the + + align:start position:0% +a sort of an extensive property of the + + + align:start position:0% +a sort of an extensive property of the +material but we also have to worry about + + align:start position:0% +material but we also have to worry about + + + align:start position:0% +material but we also have to worry about +the geometry before and after and we + + align:start position:0% +the geometry before and after and we + + + align:start position:0% +the geometry before and after and we +worry about the geometry of uh obviously + + align:start position:0% +worry about the geometry of uh obviously + + + align:start position:0% +worry about the geometry of uh obviously +the geometry of the machine is important + + align:start position:0% +the geometry of the machine is important + + + align:start position:0% +the geometry of the machine is important +you know is it straight is it square + + align:start position:0% +you know is it straight is it square + + + align:start position:0% +you know is it straight is it square +that sort of + + align:start position:0% +that sort of + + + align:start position:0% +that sort of +okay so uh let me finish up by just + + align:start position:0% +okay so uh let me finish up by just + + + align:start position:0% +okay so uh let me finish up by just +saying that we can have this + + align:start position:0% +saying that we can have this + + + align:start position:0% +saying that we can have this +model and then talk about and and why + + align:start position:0% +model and then talk about and and why + + + align:start position:0% +model and then talk about and and why +did I bother doing this? I mean, it's + + align:start position:0% +did I bother doing this? I mean, it's + + + align:start position:0% +did I bother doing this? I mean, it's +it's kind of fun. It's it's uh + + align:start position:0% +it's kind of fun. It's it's uh + + + align:start position:0% +it's kind of fun. It's it's uh +intellectually stimulating a little bit, + + align:start position:0% +intellectually stimulating a little bit, + + + align:start position:0% +intellectually stimulating a little bit, +but I think there's one real benefit to + + align:start position:0% +but I think there's one real benefit to + + + align:start position:0% +but I think there's one real benefit to +it, which is to understand why things + + align:start position:0% +it, which is to understand why things + + + align:start position:0% +it, which is to understand why things +vary. + + align:start position:0% +vary. + + + align:start position:0% +vary. +So if I take if I just say all right I'm + + align:start position:0% +So if I take if I just say all right I'm + + + align:start position:0% +So if I take if I just say all right I'm +going to subdivide all of by the way all + + align:start position:0% +going to subdivide all of by the way all + + + align:start position:0% +going to subdivide all of by the way all +all four of these + + align:start position:0% +all four of these + + + align:start position:0% +all four of these +things are subdivisions of this this + + align:start position:0% +things are subdivisions of this this + + + align:start position:0% +things are subdivisions of this this +vector alpha that I that we said is is + + align:start position:0% +vector alpha that I that we said is is + + + align:start position:0% +vector alpha that I that we said is is +what makes everything happen. Okay. So + + align:start position:0% +what makes everything happen. Okay. So + + + align:start position:0% +what makes everything happen. Okay. So +I've got alpha and then I'm going to + + align:start position:0% +I've got alpha and then I'm going to + + + align:start position:0% +I've got alpha and then I'm going to +divide that into what I'll call + + align:start position:0% +divide that into what I'll call + + + align:start position:0% +divide that into what I'll call +equipment states equipment properties + + align:start position:0% +equipment states equipment properties + + + align:start position:0% +equipment states equipment properties +material states and material properties. + + align:start position:0% +material states and material properties. + + + align:start position:0% +material states and material properties. +And why do I bother to do that? Well, in + + align:start position:0% +And why do I bother to do that? Well, in + + + align:start position:0% +And why do I bother to do that? Well, in +end, I'll give you the punch line + + align:start position:0% +end, I'll give you the punch line + + + align:start position:0% +end, I'll give you the punch line +because we're just about out of time. Is + + align:start position:0% +because we're just about out of time. Is + + + align:start position:0% +because we're just about out of time. Is +some of + + align:start position:0% +some of + + + align:start position:0% +some of +these are really easy to control, to + + align:start position:0% +these are really easy to control, to + + + align:start position:0% +these are really easy to control, to +keep fixed, and to basically know + + align:start position:0% +keep fixed, and to basically know + + + align:start position:0% +keep fixed, and to basically know +deterministically. Most of + + align:start position:0% +deterministically. Most of + + + align:start position:0% +deterministically. Most of +them certain certain categories are + + align:start position:0% +them certain certain categories are + + + align:start position:0% +them certain certain categories are +really hard to do that with. As an + + align:start position:0% +really hard to do that with. As an + + + align:start position:0% +really hard to do that with. As an +example, material + + align:start position:0% +example, material + + + align:start position:0% +example, material +properties again material property of + + align:start position:0% +properties again material property of + + + align:start position:0% +properties again material property of +this. How well do I know the properties + + align:start position:0% +this. How well do I know the properties + + + align:start position:0% +this. How well do I know the properties +of this bar of aluminum or this this + + align:start position:0% +of this bar of aluminum or this this + + + align:start position:0% +of this bar of aluminum or this this +hunk of plastic? Well, you know, I can + + align:start position:0% +hunk of plastic? Well, you know, I can + + + align:start position:0% +hunk of plastic? Well, you know, I can +do some tests and do this kind of stuff, + + align:start position:0% +do some tests and do this kind of stuff, + + + align:start position:0% +do some tests and do this kind of stuff, +but again, it can be shown that that + + align:start position:0% +but again, it can be shown that that + + + align:start position:0% +but again, it can be shown that that +these can be highly variable, + + align:start position:0% +these can be highly variable, + + + align:start position:0% +these can be highly variable, +particularly as I go from this bar to + + align:start position:0% +particularly as I go from this bar to + + + align:start position:0% +particularly as I go from this bar to +that bar to that bar. So, we're going to + + align:start position:0% +that bar to that bar. So, we're going to + + + align:start position:0% +that bar to that bar. So, we're going to +be able to argue that unless you spend a + + align:start position:0% +be able to argue that unless you spend a + + + align:start position:0% +be able to argue that unless you spend a +lot of time upstream eliminating + + align:start position:0% +lot of time upstream eliminating + + + align:start position:0% +lot of time upstream eliminating +variations like in in the unless you do + + align:start position:0% +variations like in in the unless you do + + + align:start position:0% +variations like in in the unless you do +really good process control on the + + align:start position:0% +really good process control on the + + + align:start position:0% +really good process control on the +casting and and u turning or casting and + + align:start position:0% +casting and and u turning or casting and + + + align:start position:0% +casting and and u turning or casting and +and rolling and other processes that go + + align:start position:0% +and rolling and other processes that go + + + align:start position:0% +and rolling and other processes that go +into this this will have variable + + align:start position:0% +into this this will have variable + + + align:start position:0% +into this this will have variable +properties. So this tends to be material + + align:start position:0% +properties. So this tends to be material + + + align:start position:0% +properties. So this tends to be material +properties tends to be uh + + align:start position:0% +properties tends to be uh + + + align:start position:0% +properties tends to be uh +variable and as a result depending on + + align:start position:0% +variable and as a result depending on + + + align:start position:0% +variable and as a result depending on +the process + + align:start position:0% +the process + + + align:start position:0% +the process +mechanics has a huge effect on what um + + align:start position:0% +mechanics has a huge effect on what um + + + align:start position:0% +mechanics has a huge effect on what um +what your result can be unless there + + align:start position:0% +what your result can be unless there + + + align:start position:0% +what your result can be unless there +there are some wonderful processes out + + align:start position:0% +there are some wonderful processes out + + + align:start position:0% +there are some wonderful processes out +there again like I said like machining + + align:start position:0% +there again like I said like machining + + + align:start position:0% +there again like I said like machining +that say yeah I don't really care I'm + + align:start position:0% +that say yeah I don't really care I'm + + + align:start position:0% +that say yeah I don't really care I'm +I'm very insensitive to that + + align:start position:0% +I'm very insensitive to that + + + align:start position:0% +I'm very insensitive to that +um equipment properties properties. + + align:start position:0% +um equipment properties properties. + + + align:start position:0% +um equipment properties properties. +Okay. Equipment properties. So, the + + align:start position:0% +Okay. Equipment properties. So, the + + + align:start position:0% +Okay. Equipment properties. So, the +stiffness of the machine, you know, uh + + align:start position:0% +stiffness of the machine, you know, uh + + + align:start position:0% +stiffness of the machine, you know, uh +the the temperature in a reaction + + align:start position:0% +the the temperature in a reaction + + + align:start position:0% +the the temperature in a reaction +chamber, other things like that. I'm + + align:start position:0% +chamber, other things like that. I'm + + + align:start position:0% +chamber, other things like that. I'm +sorry, not temperature uh sorry, the uh + + align:start position:0% +sorry, not temperature uh sorry, the uh + + + align:start position:0% +sorry, not temperature uh sorry, the uh +the thermal insulation in a in a uh in a + + align:start position:0% +the thermal insulation in a in a uh in a + + + align:start position:0% +the thermal insulation in a in a uh in a +in an oven, something like + + align:start position:0% +in an oven, something like + + + align:start position:0% +in an oven, something like +that. Okay. Um within limits, of course, + + align:start position:0% +that. Okay. Um within limits, of course, + + + align:start position:0% +that. Okay. Um within limits, of course, +there's some uncertainty there. It's not + + align:start position:0% +there's some uncertainty there. It's not + + + align:start position:0% +there's some uncertainty there. It's not +just variable. I I should say variable + + align:start position:0% +just variable. I I should say variable + + + align:start position:0% +just variable. I I should say variable +or + + align:start position:0% +or + + + align:start position:0% +or +uh uncertain. either one is as a source + + align:start position:0% +uh uncertain. either one is as a source + + + align:start position:0% +uh uncertain. either one is as a source +of uncertainty or variation for us. + + align:start position:0% +of uncertainty or variation for us. + + + align:start position:0% +of uncertainty or variation for us. +Um, equipment properties. Well, again, + + align:start position:0% +Um, equipment properties. Well, again, + + + align:start position:0% +Um, equipment properties. Well, again, +if I pay a lot, if I'm careful with the + + align:start position:0% +if I pay a lot, if I'm careful with the + + + align:start position:0% +if I pay a lot, if I'm careful with the +machine, if it doesn't degrade a lot + + align:start position:0% +machine, if it doesn't degrade a lot + + + align:start position:0% +machine, if it doesn't degrade a lot +over time, then I'm in good shape. + + align:start position:0% +over time, then I'm in good shape. + + + align:start position:0% +over time, then I'm in good shape. +Machines degrade over time. So, tool + + align:start position:0% +Machines degrade over time. So, tool + + + align:start position:0% +Machines degrade over time. So, tool +wear is a degradation in an equipment + + align:start position:0% +wear is a degradation in an equipment + + + align:start position:0% +wear is a degradation in an equipment +property, right? It's an expected + + align:start position:0% +property, right? It's an expected + + + align:start position:0% +property, right? It's an expected +dimension that's actually changing over + + align:start position:0% +dimension that's actually changing over + + + align:start position:0% +dimension that's actually changing over +time. So this can be + + align:start position:0% + + + + align:start position:0% + +variable over many cases long times. + + align:start position:0% +variable over many cases long times. + + + align:start position:0% +variable over many cases long times. +That's a maintenance issue as much as + + align:start position:0% +That's a maintenance issue as much as + + + align:start position:0% +That's a maintenance issue as much as +anything else. But again, it's within a + + align:start position:0% +anything else. But again, it's within a + + + align:start position:0% +anything else. But again, it's within a +question of how good the machine is. If + + align:start position:0% +question of how good the machine is. If + + + align:start position:0% +question of how good the machine is. If +you build a a machine with very sloppy + + align:start position:0% +you build a a machine with very sloppy + + + align:start position:0% +you build a a machine with very sloppy +bearings, a sloppy bearing is basically + + align:start position:0% +bearings, a sloppy bearing is basically + + + align:start position:0% +bearings, a sloppy bearing is basically +a noise generator, right? You just don't + + align:start position:0% +a noise generator, right? You just don't + + + align:start position:0% +a noise generator, right? You just don't +know where things are. If you build a + + align:start position:0% +know where things are. If you build a + + + align:start position:0% +know where things are. If you build a +machine that is supposed to distribute a + + align:start position:0% +machine that is supposed to distribute a + + + align:start position:0% +machine that is supposed to distribute a +vapor, it's got a a a some sort of a a + + align:start position:0% +vapor, it's got a a a some sort of a a + + + align:start position:0% +vapor, it's got a a a some sort of a a +vapor handling system that's supposed to + + align:start position:0% +vapor handling system that's supposed to + + + align:start position:0% +vapor handling system that's supposed to +distribute it evenly, but it clogs + + align:start position:0% +distribute it evenly, but it clogs + + + align:start position:0% +distribute it evenly, but it clogs +easily or something like that or it just + + align:start position:0% +easily or something like that or it just + + + align:start position:0% +easily or something like that or it just +wasn't designed properly, then um you've + + align:start position:0% +wasn't designed properly, then um you've + + + align:start position:0% +wasn't designed properly, then um you've +got bad properties could cause + + align:start position:0% +got bad properties could cause + + + align:start position:0% +got bad properties could cause +variability. + + align:start position:0% + + + + align:start position:0% + +um equipment + + align:start position:0% +um equipment + + + align:start position:0% +um equipment +states, forces, pressures, temperatures, + + align:start position:0% +states, forces, pressures, temperatures, + + + align:start position:0% +states, forces, pressures, temperatures, +flows, + + align:start position:0% +flows, + + + align:start position:0% +flows, +um + + align:start position:0% +um + + + align:start position:0% +um +velocities. What do you think about + + align:start position:0% +velocities. What do you think about + + + align:start position:0% +velocities. What do you think about +those in terms of our ability to control + + align:start position:0% +those in terms of our ability to control + + + align:start position:0% +those in terms of our ability to control +those and eliminate uncertainty? Good, + + align:start position:0% +those and eliminate uncertainty? Good, + + + align:start position:0% +those and eliminate uncertainty? Good, +bad, or + + align:start position:0% + + + + align:start position:0% + +indifferent? + + align:start position:0% +indifferent? + + + align:start position:0% +indifferent? +Good. We have a vote for good. + + align:start position:0% +Good. We have a vote for good. + + + align:start position:0% +Good. We have a vote for good. +on any I would I would opine that any + + align:start position:0% +on any I would I would opine that any + + + align:start position:0% +on any I would I would opine that any +machine built in the past 20 years at + + align:start position:0% +machine built in the past 20 years at + + + align:start position:0% +machine built in the past 20 years at +least it's really good and that if you + + align:start position:0% +least it's really good and that if you + + + align:start position:0% +least it's really good and that if you +will is the victory of of CNC type + + align:start position:0% +will is the victory of of CNC type + + + align:start position:0% +will is the victory of of CNC type +controls of computer controls one of the + + align:start position:0% +controls of computer controls one of the + + + align:start position:0% +controls of computer controls one of the +biggest things is that this is now very + + align:start position:0% + + + + align:start position:0% + +minimal minimal + + align:start position:0% +minimal minimal + + + align:start position:0% +minimal minimal +variation or uncertainty I know + + align:start position:0% +variation or uncertainty I know + + + align:start position:0% +variation or uncertainty I know +exactly you know if I if I have a good + + align:start position:0% +exactly you know if I if I have a good + + + align:start position:0% +exactly you know if I if I have a good +servo and I say go to this velocity it + + align:start position:0% +servo and I say go to this velocity it + + + align:start position:0% +servo and I say go to this velocity it +goes to that velocity + + align:start position:0% +goes to that velocity + + + align:start position:0% +goes to that velocity +If I have a good temperature regulator + + align:start position:0% +If I have a good temperature regulator + + + align:start position:0% +If I have a good temperature regulator +and I say go to this temperature, it'll + + align:start position:0% +and I say go to this temperature, it'll + + + align:start position:0% +and I say go to this temperature, it'll +hold that within easily within a degree + + align:start position:0% +hold that within easily within a degree + + + align:start position:0% +hold that within easily within a degree +and in some extreme cases a lot less + + align:start position:0% +and in some extreme cases a lot less + + + align:start position:0% +and in some extreme cases a lot less +than that. So with particularly with the + + align:start position:0% +than that. So with particularly with the + + + align:start position:0% +than that. So with particularly with the +use of active control, we've made that + + align:start position:0% +use of active control, we've made that + + + align:start position:0% +use of active control, we've made that +really + + align:start position:0% +really + + + align:start position:0% +really +good. So the last + + align:start position:0% +good. So the last + + + align:start position:0% +good. So the last +one and and I would say + + align:start position:0% +one and and I would say + + + align:start position:0% +one and and I would say +uncontrollable. In other words, not only + + align:start position:0% +uncontrollable. In other words, not only + + + align:start position:0% +uncontrollable. In other words, not only +is it it not variable, I can actually + + align:start position:0% +is it it not variable, I can actually + + + align:start position:0% +is it it not variable, I can actually +tell you what I want it to be. + + align:start position:0% +tell you what I want it to be. + + + align:start position:0% +tell you what I want it to be. +So I'm going to skip discussion of the + + align:start position:0% +So I'm going to skip discussion of the + + + align:start position:0% +So I'm going to skip discussion of the +material states except to say that + + align:start position:0% +material states except to say that + + + align:start position:0% +material states except to say that +they're + + align:start position:0% +they're + + + align:start position:0% +they're +always in some ways they're always + + align:start position:0% +always in some ways they're always + + + align:start position:0% +always in some ways they're always +they're + + align:start position:0% +they're + + + align:start position:0% +they're +often well let's say they are + + align:start position:0% +often well let's say they are + + + align:start position:0% +often well let's say they are +variable and hard to + + align:start position:0% +variable and hard to + + + align:start position:0% +variable and hard to +know and I'll give you my one favorite + + align:start position:0% +know and I'll give you my one favorite + + + align:start position:0% +know and I'll give you my one favorite +example of that. Let's say that I have a + + align:start position:0% +example of that. Let's say that I have a + + + align:start position:0% +example of that. Let's say that I have a +polymer that needs to be at a certain + + align:start position:0% +polymer that needs to be at a certain + + + align:start position:0% +polymer that needs to be at a certain +temperature to do what it's supposed to + + align:start position:0% +temperature to do what it's supposed to + + + align:start position:0% +temperature to do what it's supposed to +do. Typical way of doing that would be + + align:start position:0% +do. Typical way of doing that would be + + + align:start position:0% +do. Typical way of doing that would be +put it in an oven and let it sit in that + + align:start position:0% +put it in an oven and let it sit in that + + + align:start position:0% +put it in an oven and let it sit in that +oven. Okay? So the oven has certain + + align:start position:0% +oven. Okay? So the oven has certain + + + align:start position:0% +oven. Okay? So the oven has certain +properties that you know makes it keep + + align:start position:0% +properties that you know makes it keep + + + align:start position:0% +properties that you know makes it keep +uniform temperature and it has a really + + align:start position:0% +uniform temperature and it has a really + + + align:start position:0% +uniform temperature and it has a really +good temperature control on it. So if I + + align:start position:0% +good temperature control on it. So if I + + + align:start position:0% +good temperature control on it. So if I +say heat this to 100 C, it's right there + + align:start position:0% +say heat this to 100 C, it's right there + + + align:start position:0% +say heat this to 100 C, it's right there +at 100 C. So I've got this heated air + + align:start position:0% +at 100 C. So I've got this heated air + + + align:start position:0% +at 100 C. So I've got this heated air +and it's at 100 C. I take a piece of + + align:start position:0% +and it's at 100 C. I take a piece of + + + align:start position:0% +and it's at 100 C. I take a piece of +polymer and I put it in there. Um, and I + + align:start position:0% +polymer and I put it in there. Um, and I + + + align:start position:0% +polymer and I put it in there. Um, and I +wait sufficiently long that it's at + + align:start position:0% +wait sufficiently long that it's at + + + align:start position:0% +wait sufficiently long that it's at +equilibrium and the polymer is now at + + align:start position:0% +equilibrium and the polymer is now at + + + align:start position:0% +equilibrium and the polymer is now at +100 C. And then I pull it out and put it + + align:start position:0% +100 C. And then I pull it out and put it + + + align:start position:0% +100 C. And then I pull it out and put it +in a forming machine. something like + + align:start position:0% +in a forming machine. something like + + + align:start position:0% +in a forming machine. something like +that. Um, what's the temperature of the + + align:start position:0% +that. Um, what's the temperature of the + + + align:start position:0% +that. Um, what's the temperature of the +polymer when I formed it? That's a state + + align:start position:0% +polymer when I formed it? That's a state + + + align:start position:0% +polymer when I formed it? That's a state +of the polymer, right? It's a + + align:start position:0% +of the polymer, right? It's a + + + align:start position:0% +of the polymer, right? It's a +thermodynamic state of the polymer. I + + align:start position:0% +thermodynamic state of the polymer. I + + + align:start position:0% +thermodynamic state of the polymer. I +don't + + align:start position:0% +don't + + + align:start position:0% +don't +know. Unless I measure it, I don't know. + + align:start position:0% +know. Unless I measure it, I don't know. + + + align:start position:0% +know. Unless I measure it, I don't know. +I'm not controlling it anymore. Now, + + align:start position:0% +I'm not controlling it anymore. Now, + + + align:start position:0% +I'm not controlling it anymore. Now, +there are also cases, and this is true, + + align:start position:0% +there are also cases, and this is true, + + + align:start position:0% +there are also cases, and this is true, +I think, in the semiconductor world now + + align:start position:0% +I think, in the semiconductor world now + + + align:start position:0% +I think, in the semiconductor world now +more than anything else, is that if I + + align:start position:0% +more than anything else, is that if I + + + align:start position:0% +more than anything else, is that if I +want to control a temperature, for + + align:start position:0% +want to control a temperature, for + + + align:start position:0% +want to control a temperature, for +example, I don't measure the temperature + + align:start position:0% +example, I don't measure the temperature + + + align:start position:0% +example, I don't measure the temperature +of the oven or or the chamber. I measure + + align:start position:0% +of the oven or or the chamber. I measure + + + align:start position:0% +of the oven or or the chamber. I measure +the temperature of the thing that I'm + + align:start position:0% +the temperature of the thing that I'm + + + align:start position:0% +the temperature of the thing that I'm +going to uh make. And uh uh an example + + align:start position:0% +going to uh make. And uh uh an example + + + align:start position:0% +going to uh make. And uh uh an example +of that is in fact the machine that this + + align:start position:0% +of that is in fact the machine that this + + + align:start position:0% +of that is in fact the machine that this +was made on, if you guys have used this, + + align:start position:0% +was made on, if you guys have used this, + + + align:start position:0% +was made on, if you guys have used this, +the angle down in building 35, um you + + align:start position:0% +the angle down in building 35, um you + + + align:start position:0% +the angle down in building 35, um you +control the temperature usually on this + + align:start position:0% +control the temperature usually on this + + + align:start position:0% +control the temperature usually on this +process by controlling the nozzle + + align:start position:0% +process by controlling the nozzle + + + align:start position:0% +process by controlling the nozzle +temperature and the barrel temperature. + + align:start position:0% +temperature and the barrel temperature. + + + align:start position:0% +temperature and the barrel temperature. +And you say, "Oh, well that's the + + align:start position:0% +And you say, "Oh, well that's the + + + align:start position:0% +And you say, "Oh, well that's the +temperature of the polymer." But what + + align:start position:0% +temperature of the polymer." But what + + + align:start position:0% +temperature of the polymer." But what +really matters is the temperature of the + + align:start position:0% +really matters is the temperature of the + + + align:start position:0% +really matters is the temperature of the +polymer in the mold, which you never + + align:start position:0% +polymer in the mold, which you never + + + align:start position:0% +polymer in the mold, which you never +measure, right? But there's actually a + + align:start position:0% +measure, right? But there's actually a + + + align:start position:0% +measure, right? But there's actually a +little + + align:start position:0% +little + + + align:start position:0% +little +temperature sensor in the mold that you + + align:start position:0% +temperature sensor in the mold that you + + + align:start position:0% +temperature sensor in the mold that you +can uh measure that and there's also a + + align:start position:0% +can uh measure that and there's also a + + + align:start position:0% +can uh measure that and there's also a +pressure sensor in the mold. So you + + align:start position:0% +pressure sensor in the mold. So you + + + align:start position:0% +pressure sensor in the mold. So you +could you could if you wanted to + + align:start position:0% +could you could if you wanted to + + + align:start position:0% +could you could if you wanted to +actually measure the pressure on this. + + align:start position:0% +actually measure the pressure on this. + + + align:start position:0% +actually measure the pressure on this. +Okay, but it's hard to do. So this tends + + align:start position:0% +Okay, but it's hard to do. So this tends + + + align:start position:0% +Okay, but it's hard to do. So this tends +to be it's knowable but sort of + + align:start position:0% +to be it's knowable but sort of + + + align:start position:0% +to be it's knowable but sort of +expensive to do. So here's here's the + + align:start position:0% +expensive to do. So here's here's the + + + align:start position:0% +expensive to do. So here's here's the +moral of the story. biggest source of + + align:start position:0% +moral of the story. biggest source of + + + align:start position:0% +moral of the story. biggest source of +variation tends to be material + + align:start position:0% +variation tends to be material + + + align:start position:0% +variation tends to be material +uncertainties just inherent in the + + align:start position:0% +uncertainties just inherent in the + + + align:start position:0% +uncertainties just inherent in the +material and if you will the coupling + + align:start position:0% +material and if you will the coupling + + + align:start position:0% +material and if you will the coupling +between this energy source and how well + + align:start position:0% +between this energy source and how well + + + align:start position:0% +between this energy source and how well +it actually gets into the the material + + align:start position:0% +it actually gets into the the material + + + align:start position:0% +it actually gets into the the material +through sort of an uncertain interface. + + align:start position:0% +through sort of an uncertain interface. + + + align:start position:0% +through sort of an uncertain interface. +So all of these things here these three + + align:start position:0% +So all of these things here these three + + + align:start position:0% +So all of these things here these three +are your sources of variation typically + + align:start position:0% +are your sources of variation typically + + + align:start position:0% +are your sources of variation typically +in differenting measures. This is the + + align:start position:0% +in differenting measures. This is the + + + align:start position:0% +in differenting measures. This is the +one saving grace you're going to + + align:start position:0% +one saving grace you're going to + + + align:start position:0% +one saving grace you're going to +actually control way back at the + + align:start position:0% +actually control way back at the + + + align:start position:0% +actually control way back at the +beginning of the process. you're going + + align:start position:0% +beginning of the process. you're going + + + align:start position:0% +beginning of the process. you're going +to control uh equipment states. So when + + align:start position:0% +to control uh equipment states. So when + + + align:start position:0% +to control uh equipment states. So when +it's all said and done, what we + + align:start position:0% +it's all said and done, what we + + + align:start position:0% +it's all said and done, what we +manipulate here are typically not + + align:start position:0% +manipulate here are typically not + + + align:start position:0% +manipulate here are typically not +always, but typically equipment + + align:start position:0% +always, but typically equipment + + + align:start position:0% +always, but typically equipment +states, right? And our ability to do + + align:start position:0% +states, right? And our ability to do + + + align:start position:0% +states, right? And our ability to do +that has a lot and and how well I can + + align:start position:0% +that has a lot and and how well I can + + + align:start position:0% +that has a lot and and how well I can +change an equipment state to get a a + + align:start position:0% +change an equipment state to get a a + + + align:start position:0% +change an equipment state to get a a +change the sensitivity of the process + + align:start position:0% +change the sensitivity of the process + + + align:start position:0% +change the sensitivity of the process +has a lot to do with what I can do with + + align:start position:0% +has a lot to do with what I can do with + + + align:start position:0% +has a lot to do with what I can do with +its control. And the rest of the lecture + + align:start position:0% +its control. And the rest of the lecture + + + align:start position:0% +its control. And the rest of the lecture +which is in the notes is going through + + align:start position:0% +which is in the notes is going through + + + align:start position:0% +which is in the notes is going through +these three processes I've talked about + + align:start position:0% +these three processes I've talked about + + + align:start position:0% +these three processes I've talked about +and kind of addressing those issues. So + + align:start position:0% +and kind of addressing those issues. So + + + align:start position:0% +and kind of addressing those issues. So +if you have a chance take a look at the + + align:start position:0% +if you have a chance take a look at the + + + align:start position:0% +if you have a chance take a look at the +rest of those. Okay. Okay. Thank you. Uh + + align:start position:0% +rest of those. Okay. Okay. Thank you. Uh + + + align:start position:0% +rest of those. Okay. Okay. Thank you. Uh +thank you all and I won't see you next + + align:start position:0% +thank you all and I won't see you next + + + align:start position:0% +thank you all and I won't see you next +time. He will. \ No newline at end of file diff --git a/ufU6b7OHb8M.txt b/ufU6b7OHb8M.txt new file mode 100644 index 0000000000000000000000000000000000000000..af7106929ac2ffca4be6d96b8a6dc6f1459709c7 --- /dev/null +++ b/ufU6b7OHb8M.txt @@ -0,0 +1,8107 @@ +align:start position:0% + +The following content is provided under + + align:start position:0% +The following content is provided under + + + align:start position:0% +The following content is provided under +a creative common license. Your support + + align:start position:0% +a creative common license. Your support + + + align:start position:0% +a creative common license. Your support +will help MIT Open Courseware continue + + align:start position:0% +will help MIT Open Courseware continue + + + align:start position:0% +will help MIT Open Courseware continue +to offer high-quality educational + + align:start position:0% +to offer high-quality educational + + + align:start position:0% +to offer high-quality educational +resources for free. To make a donation + + align:start position:0% +resources for free. To make a donation + + + align:start position:0% +resources for free. To make a donation +or view additional materials from + + align:start position:0% +or view additional materials from + + + align:start position:0% +or view additional materials from +hundreds of MIT courses, visit MIT Open + + align:start position:0% +hundreds of MIT courses, visit MIT Open + + + align:start position:0% +hundreds of MIT courses, visit MIT Open +Courseware at ocw.mmit.edu. + + align:start position:0% + + + + align:start position:0% + +Hello and welcome. + + align:start position:0% + + + + align:start position:0% + +Today we're starting the second half of + + align:start position:0% +Today we're starting the second half of + + + align:start position:0% +Today we're starting the second half of +the class. In the second half of the + + align:start position:0% +the class. In the second half of the + + + align:start position:0% +the class. In the second half of the +class, we'll focus on methods that will + + align:start position:0% +class, we'll focus on methods that will + + + align:start position:0% +class, we'll focus on methods that will +generally be be described as forier + + align:start position:0% +generally be be described as forier + + + align:start position:0% +generally be be described as forier +methods. + + align:start position:0% +methods. + + + align:start position:0% +methods. +And those methods are revolve around + + align:start position:0% +And those methods are revolve around + + + align:start position:0% +And those methods are revolve around +thinking about signals + + align:start position:0% +thinking about signals + + + align:start position:0% +thinking about signals +as being uh sums of sine waves. So we've + + align:start position:0% +as being uh sums of sine waves. So we've + + + align:start position:0% +as being uh sums of sine waves. So we've +previously thought about how you can + + align:start position:0% +previously thought about how you can + + + align:start position:0% +previously thought about how you can +think about a system + + align:start position:0% +think about a system + + + align:start position:0% +think about a system +by thinking about how it responds to + + align:start position:0% +by thinking about how it responds to + + + align:start position:0% +by thinking about how it responds to +sine waves. So this is closely related. + + align:start position:0% +sine waves. So this is closely related. + + + align:start position:0% +sine waves. So this is closely related. +Now instead of thinking about a system + + align:start position:0% +Now instead of thinking about a system + + + align:start position:0% +Now instead of thinking about a system +as how by how it uh processes sound by + + align:start position:0% +as how by how it uh processes sound by + + + align:start position:0% +as how by how it uh processes sound by +how it processes sine waves rather we'll + + align:start position:0% +how it processes sine waves rather we'll + + + align:start position:0% +how it processes sine waves rather we'll +think about signals + + align:start position:0% +think about signals + + + align:start position:0% +think about signals +as being composed of sine waves. So + + align:start position:0% +as being composed of sine waves. So + + + align:start position:0% +as being composed of sine waves. So +that's sort of the idea and today we'll + + align:start position:0% +that's sort of the idea and today we'll + + + align:start position:0% +that's sort of the idea and today we'll +do the very simplest kind of + + align:start position:0% +do the very simplest kind of + + + align:start position:0% +do the very simplest kind of +representation which is a 4A series. Um + + align:start position:0% +representation which is a 4A series. Um + + + align:start position:0% +representation which is a 4A series. Um +the importance of that's going to be our + + align:start position:0% +the importance of that's going to be our + + + align:start position:0% +the importance of that's going to be our +first encounter with how you can think + + align:start position:0% +first encounter with how you can think + + + align:start position:0% +first encounter with how you can think +about complicated signals + + align:start position:0% +about complicated signals + + + align:start position:0% +about complicated signals +as sums of signs and cosiness but also + + align:start position:0% +as sums of signs and cosiness but also + + + align:start position:0% +as sums of signs and cosiness but also +we'll get a new representation for a + + align:start position:0% +we'll get a new representation for a + + + align:start position:0% +we'll get a new representation for a +system + + align:start position:0% +system + + + align:start position:0% +system +that will be generally useful called a + + align:start position:0% +that will be generally useful called a + + + align:start position:0% +that will be generally useful called a +filter. So that's the two agenda items + + align:start position:0% +filter. So that's the two agenda items + + + align:start position:0% +filter. So that's the two agenda items +for today roughly. The first half is on + + align:start position:0% +for today roughly. The first half is on + + + align:start position:0% +for today roughly. The first half is on +the um for a uh series representations + + align:start position:0% +the um for a uh series representations + + + align:start position:0% +the um for a uh series representations +for a signal. The second half is on + + align:start position:0% +for a signal. The second half is on + + + align:start position:0% +for a signal. The second half is on +thinking about systems as filters which + + align:start position:0% +thinking about systems as filters which + + + align:start position:0% +thinking about systems as filters which +is a direct consequence of the first. So + + align:start position:0% +is a direct consequence of the first. So + + + align:start position:0% +is a direct consequence of the first. So +the first idea is just how why should we + + align:start position:0% +the first idea is just how why should we + + + align:start position:0% +the first idea is just how why should we +even think that you can think about + + align:start position:0% +even think that you can think about + + + align:start position:0% +even think that you can think about +signals in terms of sine waves. Well, + + align:start position:0% +signals in terms of sine waves. Well, + + + align:start position:0% +signals in terms of sine waves. Well, +there's very simple examples of that. + + align:start position:0% +there's very simple examples of that. + + + align:start position:0% +there's very simple examples of that. +Some signals are just very naturally + + align:start position:0% +Some signals are just very naturally + + + align:start position:0% +Some signals are just very naturally +described that way. One class of those + + align:start position:0% +described that way. One class of those + + + align:start position:0% +described that way. One class of those +are the ones whose entire frequency + + align:start position:0% +are the ones whose entire frequency + + + align:start position:0% +are the ones whose entire frequency +content are harmonics. + + align:start position:0% +content are harmonics. + + + align:start position:0% +content are harmonics. +Just a bit of jargon. We'll think about + + align:start position:0% +Just a bit of jargon. We'll think about + + + align:start position:0% +Just a bit of jargon. We'll think about +harmonics of omega kn harmonics of some + + align:start position:0% +harmonics of omega kn harmonics of some + + + align:start position:0% +harmonics of omega kn harmonics of some +frequency say 1 khertz + + align:start position:0% +frequency say 1 khertz + + + align:start position:0% +frequency say 1 khertz +then we'll have the first harmonic + + align:start position:0% +then we'll have the first harmonic + + + align:start position:0% +then we'll have the first harmonic +that's another name for the fundamental + + align:start position:0% +that's another name for the fundamental + + + align:start position:0% +that's another name for the fundamental +that's 1 kHz and for example second + + align:start position:0% +that's 1 kHz and for example second + + + align:start position:0% +that's 1 kHz and for example second +harmonic would be some component at + + align:start position:0% +harmonic would be some component at + + + align:start position:0% +harmonic would be some component at +twice the frequency third harmonic three + + align:start position:0% +twice the frequency third harmonic three + + + align:start position:0% +twice the frequency third harmonic three +times the frequency zero harmonic for + + align:start position:0% +times the frequency zero harmonic for + + + align:start position:0% +times the frequency zero harmonic for +the completely obliv so the so for no + + align:start position:0% +the completely obliv so the so for no + + + align:start position:0% +the completely obliv so the so for no +good reason at all we'll call the zero + + align:start position:0% +good reason at all we'll call the zero + + + align:start position:0% +good reason at all we'll call the zero +earth harmonic the DC term meaning + + align:start position:0% +earth harmonic the DC term meaning + + + align:start position:0% +earth harmonic the DC term meaning +direct current which is neither direct + + align:start position:0% +direct current which is neither direct + + + align:start position:0% +direct current which is neither direct +nor has anything to do with current but + + align:start position:0% +nor has anything to do with current but + + + align:start position:0% +nor has anything to do with current but +we will use that jargon because + + align:start position:0% +we will use that jargon because + + + align:start position:0% +we will use that jargon because +everybody else does so that's just + + align:start position:0% +everybody else does so that's just + + + align:start position:0% +everybody else does so that's just +jargon + + align:start position:0% +jargon + + + align:start position:0% +jargon +what I want to think about though at a + + align:start position:0% +what I want to think about though at a + + + align:start position:0% +what I want to think about though at a +deeper level is what what kinds of + + align:start position:0% +deeper level is what what kinds of + + + align:start position:0% +deeper level is what what kinds of +signals should we expect have a good + + align:start position:0% +signals should we expect have a good + + + align:start position:0% +signals should we expect have a good +representation + + align:start position:0% +representation + + + align:start position:0% +representation +in terms of sums of signs and cosiness + + align:start position:0% +in terms of sums of signs and cosiness + + + align:start position:0% +in terms of sums of signs and cosiness +and one very easy kind of uh signal that + + align:start position:0% +and one very easy kind of uh signal that + + + align:start position:0% +and one very easy kind of uh signal that +you can think about is mu signals that + + align:start position:0% +you can think about is mu signals that + + + align:start position:0% +you can think about is mu signals that +we associate with musical instruments + + align:start position:0% +we associate with musical instruments + + + align:start position:0% +we associate with musical instruments +So, think about the sounds that these + + align:start position:0% +So, think about the sounds that these + + + align:start position:0% +So, think about the sounds that these +instruments generate. And I'll play some + + align:start position:0% +instruments generate. And I'll play some + + + align:start position:0% +instruments generate. And I'll play some +audio. And while I'm playing it, what + + align:start position:0% +audio. And while I'm playing it, what + + + align:start position:0% +audio. And while I'm playing it, what +you're supposed to be doing is thinking + + align:start position:0% +you're supposed to be doing is thinking + + + align:start position:0% +you're supposed to be doing is thinking +about what's the cues that this sounds + + align:start position:0% +about what's the cues that this sounds + + + align:start position:0% +about what's the cues that this sounds +like a sum of harmonics. + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +So the idea so using the things that we + + align:start position:0% +So the idea so using the things that we + + + align:start position:0% +So the idea so using the things that we +we'll go over today in lecture I can use + + align:start position:0% +we'll go over today in lecture I can use + + + align:start position:0% +we'll go over today in lecture I can use +I can write a Python program which I did + + align:start position:0% +I can write a Python program which I did + + + align:start position:0% +I can write a Python program which I did +to analyze each of those sounds + + align:start position:0% +to analyze each of those sounds + + + align:start position:0% +to analyze each of those sounds +to expose its harmonic structure. + + align:start position:0% +to expose its harmonic structure. + + + align:start position:0% +to expose its harmonic structure. +And here's the results. So for k= 0 DC 1 + + align:start position:0% +And here's the results. So for k= 0 DC 1 + + + align:start position:0% +And here's the results. So for k= 0 DC 1 +the fundamental two the second harmonic + + align:start position:0% +the fundamental two the second harmonic + + + align:start position:0% +the fundamental two the second harmonic +third harmonic fourth harmonic the + + align:start position:0% +third harmonic fourth harmonic the + + + align:start position:0% +third harmonic fourth harmonic the +lengths of the bars represent the + + align:start position:0% +lengths of the bars represent the + + + align:start position:0% +lengths of the bars represent the +magnitudes how much energy well roughly + + align:start position:0% +magnitudes how much energy well roughly + + + align:start position:0% +magnitudes how much energy well roughly +energy how much signal is present at + + align:start position:0% +energy how much signal is present at + + + align:start position:0% +energy how much signal is present at +those harmonic frequencies as a function + + align:start position:0% +those harmonic frequencies as a function + + + align:start position:0% +those harmonic frequencies as a function +of harmonic number k for each of the + + align:start position:0% +of harmonic number k for each of the + + + align:start position:0% +of harmonic number k for each of the +different instruments. And just like uh + + align:start position:0% +different instruments. And just like uh + + + align:start position:0% +different instruments. And just like uh +the time waveforms have a signature, + + align:start position:0% +the time waveforms have a signature, + + + align:start position:0% +the time waveforms have a signature, +there was a characteristic shape. In + + align:start position:0% +there was a characteristic shape. In + + + align:start position:0% +there was a characteristic shape. In +fact, if I go on, here's the + + align:start position:0% +fact, if I go on, here's the + + + align:start position:0% +fact, if I go on, here's the +characteristic shape. That's an actual + + align:start position:0% +characteristic shape. That's an actual + + + align:start position:0% +characteristic shape. That's an actual +waveform taken from the audio clip that + + align:start position:0% +waveform taken from the audio clip that + + + align:start position:0% +waveform taken from the audio clip that +I played. That's a clip from the piano. + + align:start position:0% +I played. That's a clip from the piano. + + + align:start position:0% +I played. That's a clip from the piano. +This is a clip of the same time duration + + align:start position:0% +This is a clip of the same time duration + + + align:start position:0% +This is a clip of the same time duration +from the violin. Uh a clip of the same + + align:start position:0% +from the violin. Uh a clip of the same + + + align:start position:0% +from the violin. Uh a clip of the same +time duration from the bassoon. + + align:start position:0% +time duration from the bassoon. + + + align:start position:0% +time duration from the bassoon. +And here are the harmonic structures + + align:start position:0% +And here are the harmonic structures + + + align:start position:0% +And here are the harmonic structures +for those different sounds. And you can + + align:start position:0% +for those different sounds. And you can + + + align:start position:0% +for those different sounds. And you can +see the harmonic structures look very + + align:start position:0% +see the harmonic structures look very + + + align:start position:0% +see the harmonic structures look very +different, right? So, uh, not much DC, a + + align:start position:0% +different, right? So, uh, not much DC, a + + + align:start position:0% +different, right? So, uh, not much DC, a +fair amount of fundamental, a lot of + + align:start position:0% +fair amount of fundamental, a lot of + + + align:start position:0% +fair amount of fundamental, a lot of +second, + + align:start position:0% +second, + + + align:start position:0% +second, +uh, a lot of fundamental, not much + + align:start position:0% +uh, a lot of fundamental, not much + + + align:start position:0% +uh, a lot of fundamental, not much +second, + + align:start position:0% +second, + + + align:start position:0% +second, +not much fundamental. That's kind of + + align:start position:0% +not much fundamental. That's kind of + + + align:start position:0% +not much fundamental. That's kind of +interesting. The bassoon is special in + + align:start position:0% +interesting. The bassoon is special in + + + align:start position:0% +interesting. The bassoon is special in +this class because there's not much + + align:start position:0% +this class because there's not much + + + align:start position:0% +this class because there's not much +fundamental, but there's a lot of + + align:start position:0% +fundamental, but there's a lot of + + + align:start position:0% +fundamental, but there's a lot of +second. + + align:start position:0% +second. + + + align:start position:0% +second. +So now think about comparing these two + + align:start position:0% +So now think about comparing these two + + + align:start position:0% +So now think about comparing these two +and listen to them again. + + align:start position:0% + + + + align:start position:0% + +So what what I want you to try to think + + align:start position:0% +So what what I want you to try to think + + + align:start position:0% +So what what I want you to try to think +about and it's kind of hard. Think about + + align:start position:0% +about and it's kind of hard. Think about + + + align:start position:0% +about and it's kind of hard. Think about +how it is that the harmonic structure is + + align:start position:0% +how it is that the harmonic structure is + + + align:start position:0% +how it is that the harmonic structure is +playing a role in determining the the + + align:start position:0% +playing a role in determining the the + + + align:start position:0% +playing a role in determining the the +tamber + + align:start position:0% +tamber + + + align:start position:0% +tamber +of the sound that you're hearing. Okay, + + align:start position:0% +of the sound that you're hearing. Okay, + + + align:start position:0% +of the sound that you're hearing. Okay, +so that's kind of the motivation. Um, + + align:start position:0% +so that's kind of the motivation. Um, + + + align:start position:0% +so that's kind of the motivation. Um, +another motivation is that thinking + + align:start position:0% +another motivation is that thinking + + + align:start position:0% +another motivation is that thinking +about signals in terms of their harmonic + + align:start position:0% +about signals in terms of their harmonic + + + align:start position:0% +about signals in terms of their harmonic +structure can provide important insights + + align:start position:0% +structure can provide important insights + + + align:start position:0% +structure can provide important insights +into the signals. And so for example in + + align:start position:0% +into the signals. And so for example in + + + align:start position:0% +into the signals. And so for example in +music the harmonic structure is what + + align:start position:0% +music the harmonic structure is what + + + align:start position:0% +music the harmonic structure is what +determines uh um consonants and + + align:start position:0% +determines uh um consonants and + + + align:start position:0% +determines uh um consonants and +dissonance + + align:start position:0% +dissonance + + + align:start position:0% +dissonance +dissonance. So uh I'm going to play two + + align:start position:0% +dissonance. So uh I'm going to play two + + + align:start position:0% +dissonance. So uh I'm going to play two +tone two u two different notes that are + + align:start position:0% +tone two u two different notes that are + + + align:start position:0% +tone two u two different notes that are +related by an octave shift by a fifth + + align:start position:0% +related by an octave shift by a fifth + + + align:start position:0% +related by an octave shift by a fifth +shift and uh adjacent notes in in the + + align:start position:0% +shift and uh adjacent notes in in the + + + align:start position:0% +shift and uh adjacent notes in in the +semmitone scale. + + align:start position:0% +semmitone scale. + + + align:start position:0% +semmitone scale. +And below it, I've illustrated the + + align:start position:0% +And below it, I've illustrated the + + + align:start position:0% +And below it, I've illustrated the +harmonic structure for the uh D and for + + align:start position:0% +harmonic structure for the uh D and for + + + align:start position:0% +harmonic structure for the uh D and for +D prime. Okay, so an octave above means + + align:start position:0% +D prime. Okay, so an octave above means + + + align:start position:0% +D prime. Okay, so an octave above means +that the first harmonic, the fundamental + + align:start position:0% +that the first harmonic, the fundamental + + + align:start position:0% +that the first harmonic, the fundamental +of this guy corresponds to the second + + align:start position:0% +of this guy corresponds to the second + + + align:start position:0% +of this guy corresponds to the second +harmonic of this guy. The second to the + + align:start position:0% +harmonic of this guy. The second to the + + + align:start position:0% +harmonic of this guy. The second to the +fourth, etc. There's some relationship + + align:start position:0% +fourth, etc. There's some relationship + + + align:start position:0% +fourth, etc. There's some relationship +for the fifths illustrated here. And + + align:start position:0% +for the fifths illustrated here. And + + + align:start position:0% +for the fifths illustrated here. And +there's a different illust there's a + + align:start position:0% +there's a different illust there's a + + + align:start position:0% +there's a different illust there's a +different relationship here. So what I + + align:start position:0% +different relationship here. So what I + + + align:start position:0% +different relationship here. So what I +want you to do is hear the difference + + align:start position:0% +want you to do is hear the difference + + + align:start position:0% +want you to do is hear the difference +between those six sounds and again think + + align:start position:0% +between those six sounds and again think + + + align:start position:0% +between those six sounds and again think +about uh not only the time waveform but + + align:start position:0% +about uh not only the time waveform but + + + align:start position:0% +about uh not only the time waveform but +also how their harmonics relate. + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +So, um, dissonance has something to do, + + align:start position:0% +So, um, dissonance has something to do, + + + align:start position:0% +So, um, dissonance has something to do, +well, consonants has something to do + + align:start position:0% +well, consonants has something to do + + + align:start position:0% +well, consonants has something to do +with the overlap + + align:start position:0% +with the overlap + + + align:start position:0% +with the overlap +of the harmonic structure and dissonance + + align:start position:0% +of the harmonic structure and dissonance + + + align:start position:0% +of the harmonic structure and dissonance +has something to do with the lack of + + align:start position:0% +has something to do with the lack of + + + align:start position:0% +has something to do with the lack of +overlap + + align:start position:0% +overlap + + + align:start position:0% +overlap +of the harmonic content. So the point + + align:start position:0% +of the harmonic content. So the point + + + align:start position:0% +of the harmonic content. So the point +just being that you we can we can get + + align:start position:0% +just being that you we can we can get + + + align:start position:0% +just being that you we can we can get +some mileage out of thinking about + + align:start position:0% +some mileage out of thinking about + + + align:start position:0% +some mileage out of thinking about +signals + + align:start position:0% +signals + + + align:start position:0% +signals +according to their harmonic + + align:start position:0% +according to their harmonic + + + align:start position:0% +according to their harmonic +decomposition. So that's kind of the uh + + align:start position:0% +decomposition. So that's kind of the uh + + + align:start position:0% +decomposition. So that's kind of the uh +introduction. + + align:start position:0% +introduction. + + + align:start position:0% +introduction. +How should we think about that? What + + align:start position:0% +How should we think about that? What + + + align:start position:0% +How should we think about that? What +kinds of signals ought to be + + align:start position:0% +kinds of signals ought to be + + + align:start position:0% +kinds of signals ought to be +representable + + align:start position:0% +representable + + + align:start position:0% +representable +by their harmonic structure? Okay. Well, + + align:start position:0% +by their harmonic structure? Okay. Well, + + + align:start position:0% +by their harmonic structure? Okay. Well, +if you just draw a picture in the time + + align:start position:0% +if you just draw a picture in the time + + + align:start position:0% +if you just draw a picture in the time +domain and think about a fundamental, + + align:start position:0% +domain and think about a fundamental, + + + align:start position:0% +domain and think about a fundamental, +what would it look like in the time + + align:start position:0% +what would it look like in the time + + + align:start position:0% +what would it look like in the time +domain? What would the signal look like? + + align:start position:0% +domain? What would the signal look like? + + + align:start position:0% +domain? What would the signal look like? +What would the second harmonic look + + align:start position:0% +What would the second harmonic look + + + align:start position:0% +What would the second harmonic look +like? Well, that's a that's a signal + + align:start position:0% +like? Well, that's a that's a signal + + + align:start position:0% +like? Well, that's a that's a signal +whose frequency is twice as big. + + align:start position:0% +whose frequency is twice as big. + + + align:start position:0% +whose frequency is twice as big. +If the frequency is twice as big, the + + align:start position:0% +If the frequency is twice as big, the + + + align:start position:0% +If the frequency is twice as big, the +period is half as big. So, there's now + + align:start position:0% +period is half as big. So, there's now + + + align:start position:0% +period is half as big. So, there's now +two periods of the blue guy + + align:start position:0% +two periods of the blue guy + + + align:start position:0% +two periods of the blue guy +in the same time interval as one period + + align:start position:0% +in the same time interval as one period + + + align:start position:0% +in the same time interval as one period +of the red guy. + + align:start position:0% +of the red guy. + + + align:start position:0% +of the red guy. +Okay. So the relationship of frequencies + + align:start position:0% +Okay. So the relationship of frequencies + + + align:start position:0% +Okay. So the relationship of frequencies +in the harmonics has a relationship in + + align:start position:0% +in the harmonics has a relationship in + + + align:start position:0% +in the harmonics has a relationship in +time + + align:start position:0% +time + + + align:start position:0% +time +and it's proportion or it's inversely + + align:start position:0% +and it's proportion or it's inversely + + + align:start position:0% +and it's proportion or it's inversely +proportional. Okay. So if you think + + align:start position:0% +proportional. Okay. So if you think + + + align:start position:0% +proportional. Okay. So if you think +about uh fundamental second third fourth + + align:start position:0% +about uh fundamental second third fourth + + + align:start position:0% +about uh fundamental second third fourth +fifth fundamental second third fourth + + align:start position:0% +fifth fundamental second third fourth + + + align:start position:0% +fifth fundamental second third fourth +fifth there's a relationship between in + + align:start position:0% +fifth there's a relationship between in + + + align:start position:0% +fifth there's a relationship between in +time of the periods. + + align:start position:0% +time of the periods. + + + align:start position:0% +time of the periods. +And one thing that should be clear is + + align:start position:0% +And one thing that should be clear is + + + align:start position:0% +And one thing that should be clear is +that the these harmonics are all + + align:start position:0% +that the these harmonics are all + + + align:start position:0% +that the these harmonics are all +periodic in the period of the + + align:start position:0% +periodic in the period of the + + + align:start position:0% +periodic in the period of the +fundamental. + + align:start position:0% +fundamental. + + + align:start position:0% +fundamental. +So one thing that you can think about by + + align:start position:0% +So one thing that you can think about by + + + align:start position:0% +So one thing that you can think about by +thinking about the time representation + + align:start position:0% +thinking about the time representation + + + align:start position:0% +thinking about the time representation +of what harmonic signals ought to look + + align:start position:0% +of what harmonic signals ought to look + + + align:start position:0% +of what harmonic signals ought to look +like, periodic signals + + align:start position:0% +like, periodic signals + + + align:start position:0% +like, periodic signals +are sort of our only candidates. + + align:start position:0% +are sort of our only candidates. + + + align:start position:0% +are sort of our only candidates. +All of the harmonics + + align:start position:0% +All of the harmonics + + + align:start position:0% +All of the harmonics +of a fundamental have the same are are + + align:start position:0% +of a fundamental have the same are are + + + align:start position:0% +of a fundamental have the same are are +periodic in capital T the period of the + + align:start position:0% +periodic in capital T the period of the + + + align:start position:0% +periodic in capital T the period of the +fundamental. So it's going to be hard to + + align:start position:0% +fundamental. So it's going to be hard to + + + align:start position:0% +fundamental. So it's going to be hard to +generate a signal by a sum of harmonics + + align:start position:0% +generate a signal by a sum of harmonics + + + align:start position:0% +generate a signal by a sum of harmonics +that doesn't have that periodicity. + + align:start position:0% +that doesn't have that periodicity. + + + align:start position:0% +that doesn't have that periodicity. +Right? So we should be expecting a + + align:start position:0% +Right? So we should be expecting a + + + align:start position:0% +Right? So we should be expecting a +relationship between signals that can be + + align:start position:0% +relationship between signals that can be + + + align:start position:0% +relationship between signals that can be +represented by a sum of harmonics + + align:start position:0% +represented by a sum of harmonics + + + align:start position:0% +represented by a sum of harmonics +and periodic signals. + + align:start position:0% + + + + align:start position:0% + +So we would not expect an aperiodic + + align:start position:0% +So we would not expect an aperiodic + + + align:start position:0% +So we would not expect an aperiodic +signal to be represented this way. The + + align:start position:0% +signal to be represented this way. The + + + align:start position:0% +signal to be represented this way. The +the counter question is should we be + + align:start position:0% +the counter question is should we be + + + align:start position:0% +the counter question is should we be +expecting that all periodic signals can + + align:start position:0% +expecting that all periodic signals can + + + align:start position:0% +expecting that all periodic signals can +be represented this way or some periodic + + align:start position:0% +be represented this way or some periodic + + + align:start position:0% +be represented this way or some periodic +signals or some very special class? Is + + align:start position:0% +signals or some very special class? Is + + + align:start position:0% +signals or some very special class? Is +it a big class or a small class? How do + + align:start position:0% +it a big class or a small class? How do + + + align:start position:0% +it a big class or a small class? How do +we think about that? And historically + + align:start position:0% +we think about that? And historically + + + align:start position:0% +we think about that? And historically +that's been a hard question. And by the + + align:start position:0% +that's been a hard question. And by the + + + align:start position:0% +that's been a hard question. And by the +end of the hour I I hope that you all + + align:start position:0% +end of the hour I I hope that you all + + + align:start position:0% +end of the hour I I hope that you all +understand why it was a hard question. + + align:start position:0% +understand why it was a hard question. + + + align:start position:0% +understand why it was a hard question. +uh people like Furier, you might + + align:start position:0% +uh people like Furier, you might + + + align:start position:0% +uh people like Furier, you might +imagine, advocated the notion + + align:start position:0% +imagine, advocated the notion + + + align:start position:0% +imagine, advocated the notion +that you can make a meaningful harmonic + + align:start position:0% +that you can make a meaningful harmonic + + + align:start position:0% +that you can make a meaningful harmonic +uh representation for a very wide class + + align:start position:0% +uh representation for a very wide class + + + align:start position:0% +uh representation for a very wide class +of signals. Forier claimed basically + + align:start position:0% +of signals. Forier claimed basically + + + align:start position:0% +of signals. Forier claimed basically +everything anything that was periodic + + align:start position:0% +everything anything that was periodic + + + align:start position:0% +everything anything that was periodic +could be represented in terms of a sum + + align:start position:0% +could be represented in terms of a sum + + + align:start position:0% +could be represented in terms of a sum +of harmonics. Other people thought that + + align:start position:0% +of harmonics. Other people thought that + + + align:start position:0% +of harmonics. Other people thought that +was preposterous. + + align:start position:0% +was preposterous. + + + align:start position:0% +was preposterous. +uh in a widely reported public rebuke of + + align:start position:0% +uh in a widely reported public rebuke of + + + align:start position:0% +uh in a widely reported public rebuke of +uh furier lrange said this is ridiculous + + align:start position:0% +uh furier lrange said this is ridiculous + + + align:start position:0% +uh furier lrange said this is ridiculous +because every harmonic is a continuous + + align:start position:0% +because every harmonic is a continuous + + + align:start position:0% +because every harmonic is a continuous +function of time + + align:start position:0% +function of time + + + align:start position:0% +function of time +and you can easily manufacture a + + align:start position:0% +and you can easily manufacture a + + + align:start position:0% +and you can easily manufacture a +periodic signal that's a discontinuous + + align:start position:0% +periodic signal that's a discontinuous + + + align:start position:0% +periodic signal that's a discontinuous +function of time + + align:start position:0% +function of time + + + align:start position:0% +function of time +so for example a square wave + + align:start position:0% +so for example a square wave + + + align:start position:0% +so for example a square wave +how on earth argued lrange how on earth + + align:start position:0% +how on earth argued lrange how on earth + + + align:start position:0% +how on earth argued lrange how on earth +would you represent + + align:start position:0% +would you represent + + + align:start position:0% +would you represent +a discontinuous function by a sum of + + align:start position:0% +a discontinuous function by a sum of + + + align:start position:0% +a discontinuous function by a sum of +continuous functions. That makes no + + align:start position:0% +continuous functions. That makes no + + + align:start position:0% +continuous functions. That makes no +sense, right? So, um what what we will + + align:start position:0% +sense, right? So, um what what we will + + + align:start position:0% +sense, right? So, um what what we will +want to do in the course of the hour is + + align:start position:0% +want to do in the course of the hour is + + + align:start position:0% +want to do in the course of the hour is +think about does that or doesn't that + + align:start position:0% +think about does that or doesn't that + + + align:start position:0% +think about does that or doesn't that +make sense and it'll turn out the answer + + align:start position:0% +make sense and it'll turn out the answer + + + align:start position:0% +make sense and it'll turn out the answer +is kind of complicated + + align:start position:0% +is kind of complicated + + + align:start position:0% +is kind of complicated +and so we can sort of forgive both sides + + align:start position:0% +and so we can sort of forgive both sides + + + align:start position:0% +and so we can sort of forgive both sides +for having sort of u argued with each + + align:start position:0% +for having sort of u argued with each + + + align:start position:0% +for having sort of u argued with each +other because the answer is not + + align:start position:0% +other because the answer is not + + + align:start position:0% +other because the answer is not +completely obvious. + + align:start position:0% +completely obvious. + + + align:start position:0% +completely obvious. +For the time being, I'm going to just + + align:start position:0% +For the time being, I'm going to just + + + align:start position:0% +For the time being, I'm going to just +assume that the answer is yes. + + align:start position:0% + + + + align:start position:0% + +that it makes sense to try to make a + + align:start position:0% +that it makes sense to try to make a + + + align:start position:0% +that it makes sense to try to make a +harmonic representation of a signal that + + align:start position:0% +harmonic representation of a signal that + + + align:start position:0% +harmonic representation of a signal that +might even be discontinuous. I'm going + + align:start position:0% +might even be discontinuous. I'm going + + + align:start position:0% +might even be discontinuous. I'm going +to assume periodic. Let's try and the + + align:start position:0% +to assume periodic. Let's try and the + + + align:start position:0% +to assume periodic. Let's try and the +question will be does that make any + + align:start position:0% +question will be does that make any + + + align:start position:0% +question will be does that make any +sense? + + align:start position:0% +sense? + + + align:start position:0% +sense? +So there's a there's a little bit of + + align:start position:0% +So there's a there's a little bit of + + + align:start position:0% +So there's a there's a little bit of +math there's a mathematical foundation + + align:start position:0% +math there's a mathematical foundation + + + align:start position:0% +math there's a mathematical foundation +that makes understanding these forier + + align:start position:0% +that makes understanding these forier + + + align:start position:0% +that makes understanding these forier +series very easy. The idea is uh has two + + align:start position:0% +series very easy. The idea is uh has two + + + align:start position:0% +series very easy. The idea is uh has two +parts. First off, if you have a + + align:start position:0% +parts. First off, if you have a + + + align:start position:0% +parts. First off, if you have a +sinosoidally varying signal here at + + align:start position:0% +sinosoidally varying signal here at + + + align:start position:0% +sinosoidally varying signal here at +frequency k omega kn, the kith harmonic, + + align:start position:0% +frequency k omega kn, the kith harmonic, + + + align:start position:0% +frequency k omega kn, the kith harmonic, +if you were to multiply the kith + + align:start position:0% +if you were to multiply the kith + + + align:start position:0% +if you were to multiply the kith +harmonic times the elf harmonic, + + align:start position:0% + + + + align:start position:0% + +a signal of frequency k omega times a + + align:start position:0% +a signal of frequency k omega times a + + + align:start position:0% +a signal of frequency k omega times a +signal of frequency l omega, you get a + + align:start position:0% +signal of frequency l omega, you get a + + + align:start position:0% +signal of frequency l omega, you get a +new harmonic, the k plus one. That's a + + align:start position:0% +new harmonic, the k plus one. That's a + + + align:start position:0% +new harmonic, the k plus one. That's a +simple property of the way the product + + align:start position:0% +simple property of the way the product + + + align:start position:0% +simple property of the way the product +of two exponents you you add the + + align:start position:0% +of two exponents you you add the + + + align:start position:0% +of two exponents you you add the +exponents when you take the product of + + align:start position:0% +exponents when you take the product of + + + align:start position:0% +exponents when you take the product of +of two exponentials. + + align:start position:0% +of two exponentials. + + + align:start position:0% +of two exponentials. +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +So that makes it very easy to think + + align:start position:0% +So that makes it very easy to think + + + align:start position:0% +So that makes it very easy to think +about harmonic structure because there's + + align:start position:0% +about harmonic structure because there's + + + align:start position:0% +about harmonic structure because there's +a simple relationship for for generating + + align:start position:0% +a simple relationship for for generating + + + align:start position:0% +a simple relationship for for generating +one harmonic signal in time from another + + align:start position:0% +one harmonic signal in time from another + + + align:start position:0% +one harmonic signal in time from another +harmonic signal in time. + + align:start position:0% +harmonic signal in time. + + + align:start position:0% +harmonic signal in time. +The second thing that makes uh harmonics + + align:start position:0% +The second thing that makes uh harmonics + + + align:start position:0% +The second thing that makes uh harmonics +easy to uh think about mathematically is + + align:start position:0% +easy to uh think about mathematically is + + + align:start position:0% +easy to uh think about mathematically is +that if you integrate over a period, + + align:start position:0% +that if you integrate over a period, + + + align:start position:0% +that if you integrate over a period, +we'll do this so often that we'll + + align:start position:0% +we'll do this so often that we'll + + + align:start position:0% +we'll do this so often that we'll +abbreviate it this way because if you + + align:start position:0% +abbreviate it this way because if you + + + align:start position:0% +abbreviate it this way because if you +have a signal that's periodic, it really + + align:start position:0% +have a signal that's periodic, it really + + + align:start position:0% +have a signal that's periodic, it really +doesn't matter which period you choose + + align:start position:0% +doesn't matter which period you choose + + + align:start position:0% +doesn't matter which period you choose +to do the integral over. If you had a a + + align:start position:0% +to do the integral over. If you had a a + + + align:start position:0% +to do the integral over. If you had a a +signal that was periodic in say capital + + align:start position:0% +signal that was periodic in say capital + + + align:start position:0% +signal that was periodic in say capital +T and integrated it between zero and T, + + align:start position:0% +T and integrated it between zero and T, + + + align:start position:0% +T and integrated it between zero and T, +and if it's periodic, you should be able + + align:start position:0% +and if it's periodic, you should be able + + + align:start position:0% +and if it's periodic, you should be able +to shift that window anywhere you like + + align:start position:0% +to shift that window anywhere you like + + + align:start position:0% +to shift that window anywhere you like +and you should get the same thing. + + align:start position:0% +and you should get the same thing. + + + align:start position:0% +and you should get the same thing. +So we'll not worry about whether it goes + + align:start position:0% +So we'll not worry about whether it goes + + + align:start position:0% +So we'll not worry about whether it goes +from zero to capital t or from 1 to + + align:start position:0% +from zero to capital t or from 1 to + + + align:start position:0% +from zero to capital t or from 1 to +capital t + one. We won't worry about + + align:start position:0% +capital t + one. We won't worry about + + + align:start position:0% +capital t + one. We won't worry about +that. We'll just say integrate over the + + align:start position:0% +that. We'll just say integrate over the + + + align:start position:0% +that. We'll just say integrate over the +period t. If you integrate over the + + align:start position:0% +period t. If you integrate over the + + + align:start position:0% +period t. If you integrate over the +period t any harmonic signal + + align:start position:0% +period t any harmonic signal + + + align:start position:0% +period t any harmonic signal +then there's only two possible answers. + + align:start position:0% +then there's only two possible answers. + + + align:start position:0% +then there's only two possible answers. +So if you integrate e to the j k omega t + + align:start position:0% +So if you integrate e to the j k omega t + + + align:start position:0% +So if you integrate e to the j k omega t +over u one period of omega kn + + align:start position:0% +over u one period of omega kn + + + align:start position:0% +over u one period of omega kn +there will be k periods in there. + + align:start position:0% +there will be k periods in there. + + + align:start position:0% +there will be k periods in there. +So if k is a number other than zero + + align:start position:0% +So if k is a number other than zero + + + align:start position:0% +So if k is a number other than zero +you'll have complete periods of a sine + + align:start position:0% +you'll have complete periods of a sine + + + align:start position:0% +you'll have complete periods of a sine +wave. So the answer of the integral the + + align:start position:0% +wave. So the answer of the integral the + + + align:start position:0% +wave. So the answer of the integral the +average value over that period is zero. + + align:start position:0% +average value over that period is zero. + + + align:start position:0% +average value over that period is zero. +The only time you'll ever get something + + align:start position:0% +The only time you'll ever get something + + + align:start position:0% +The only time you'll ever get something +that's non zero is if k were zero. + + align:start position:0% +that's non zero is if k were zero. + + + align:start position:0% +that's non zero is if k were zero. +If k were zero. If it were DC, + + align:start position:0% +If k were zero. If it were DC, + + + align:start position:0% +If k were zero. If it were DC, +then e to the 0 is one. The integral of + + align:start position:0% +then e to the 0 is one. The integral of + + + align:start position:0% +then e to the 0 is one. The integral of +one over a period, regardless of what + + align:start position:0% +one over a period, regardless of what + + + align:start position:0% +one over a period, regardless of what +period you pick up, the integral of one + + align:start position:0% +period you pick up, the integral of one + + + align:start position:0% +period you pick up, the integral of one +over a period is capital t. + + align:start position:0% +over a period is capital t. + + + align:start position:0% +over a period is capital t. +So it becomes so two things. It's easy + + align:start position:0% +So it becomes so two things. It's easy + + + align:start position:0% +So it becomes so two things. It's easy +to figure out the product of two + + align:start position:0% +to figure out the product of two + + + align:start position:0% +to figure out the product of two +harmonic signals. It's just a different + + align:start position:0% +harmonic signals. It's just a different + + + align:start position:0% +harmonic signals. It's just a different +harmonic. And uh integrals over a period + + align:start position:0% +harmonic. And uh integrals over a period + + + align:start position:0% +harmonic. And uh integrals over a period +are easy with that basis. Then it's easy + + align:start position:0% +are easy with that basis. Then it's easy + + + align:start position:0% +are easy with that basis. Then it's easy +to say how let's imagine that some + + align:start position:0% +to say how let's imagine that some + + + align:start position:0% +to say how let's imagine that some +arbitrary periodic signal which we can + + align:start position:0% +arbitrary periodic signal which we can + + + align:start position:0% +arbitrary periodic signal which we can +always write this way x of t if it's + + align:start position:0% +always write this way x of t if it's + + + align:start position:0% +always write this way x of t if it's +periodic could also be written x of t + + align:start position:0% +periodic could also be written x of t + + + align:start position:0% +periodic could also be written x of t +plus capital t if x if x of t is + + align:start position:0% +plus capital t if x if x of t is + + + align:start position:0% +plus capital t if x if x of t is +periodic in capital t. Let's assume that + + align:start position:0% +periodic in capital t. Let's assume that + + + align:start position:0% +periodic in capital t. Let's assume that +that can be written as a sum of + + align:start position:0% +that can be written as a sum of + + + align:start position:0% +that can be written as a sum of +harmonics. + + align:start position:0% +harmonics. + + + align:start position:0% +harmonics. +So a sum k= minus infinity to infinity + + align:start position:0% +So a sum k= minus infinity to infinity + + + align:start position:0% +So a sum k= minus infinity to infinity +of some amount of e to the j omega kt. + + align:start position:0% +of some amount of e to the j omega kt. + + + align:start position:0% +of some amount of e to the j omega kt. +Why do I have the minus k's in there? + + align:start position:0% + + + + align:start position:0% + +Okay, I've asked this question about six + + align:start position:0% +Okay, I've asked this question about six + + + align:start position:0% +Okay, I've asked this question about six +times. + + align:start position:0% +times. + + + align:start position:0% +times. +Why do I have a minus case in there? + + align:start position:0% + + + + align:start position:0% + +Yeah. + + align:start position:0% +Yeah. + + + align:start position:0% +Yeah. +Precisely. + + align:start position:0% +Precisely. + + + align:start position:0% +Precisely. +We like Oilers's equation. We like + + align:start position:0% +We like Oilers's equation. We like + + + align:start position:0% +We like Oilers's equation. We like +complex numbers. We don't like cosiness + + align:start position:0% +complex numbers. We don't like cosiness + + + align:start position:0% +complex numbers. We don't like cosiness +and signs. And we can convert SS and + + align:start position:0% +and signs. And we can convert SS and + + + align:start position:0% +and signs. And we can convert SS and +cosiness into complex exponentials using + + align:start position:0% +cosiness into complex exponentials using + + + align:start position:0% +cosiness into complex exponentials using +Oilers's formula. And any everything's + + align:start position:0% +Oilers's formula. And any everything's + + + align:start position:0% +Oilers's formula. And any everything's +very easy, right? So we use minus K for + + align:start position:0% +very easy, right? So we use minus K for + + + align:start position:0% +very easy, right? So we use minus K for +the same reason that we use minus omega + + align:start position:0% +the same reason that we use minus omega + + + align:start position:0% +the same reason that we use minus omega +in previous representations. + + align:start position:0% +in previous representations. + + + align:start position:0% +in previous representations. +So imagine that we can write x of t some + + align:start position:0% +So imagine that we can write x of t some + + + align:start position:0% +So imagine that we can write x of t some +generic periodic signal as a sum of + + align:start position:0% +generic periodic signal as a sum of + + + align:start position:0% +generic periodic signal as a sum of +harmonics. + + align:start position:0% +harmonics. + + + align:start position:0% +harmonics. +Then let's use those principles that we + + align:start position:0% +Then let's use those principles that we + + + align:start position:0% +Then let's use those principles that we +talked about before. If that can be + + align:start position:0% +talked about before. If that can be + + + align:start position:0% +talked about before. If that can be +represented as a sum, I can sift out the + + align:start position:0% +represented as a sum, I can sift out the + + + align:start position:0% +represented as a sum, I can sift out the +one of interest + + align:start position:0% +one of interest + + + align:start position:0% +one of interest +by multiplying x of t times e to the + + align:start position:0% +by multiplying x of t times e to the + + + align:start position:0% +by multiplying x of t times e to the +minus j l omega. We'll see in a minute + + align:start position:0% +minus j l omega. We'll see in a minute + + + align:start position:0% +minus j l omega. We'll see in a minute +what I mean by sift out and why I'm + + align:start position:0% +what I mean by sift out and why I'm + + + align:start position:0% +what I mean by sift out and why I'm +using minus instead of plus. + + align:start position:0% +using minus instead of plus. + + + align:start position:0% +using minus instead of plus. +If you were to run this integral over a + + align:start position:0% +If you were to run this integral over a + + + align:start position:0% +If you were to run this integral over a +period + + align:start position:0% +period + + + align:start position:0% +period +and imagine for the moment that all the + + align:start position:0% +and imagine for the moment that all the + + + align:start position:0% +and imagine for the moment that all the +sums are well behaved so nothing + + align:start position:0% +sums are well behaved so nothing + + + align:start position:0% +sums are well behaved so nothing +explodes and so all the convergence + + align:start position:0% +explodes and so all the convergence + + + align:start position:0% +explodes and so all the convergence +issues are are trivial. If I if the + + align:start position:0% +issues are are trivial. If I if the + + + align:start position:0% +issues are are trivial. If I if the +convergence issues were trivial then I + + align:start position:0% +convergence issues were trivial then I + + + align:start position:0% +convergence issues were trivial then I +could swap the sum in the integral. + + align:start position:0% +could swap the sum in the integral. + + + align:start position:0% +could swap the sum in the integral. +If I did that, then I would end up with + + align:start position:0% +If I did that, then I would end up with + + + align:start position:0% +If I did that, then I would end up with +a sum of a bunch of different ks. But + + align:start position:0% +a sum of a bunch of different ks. But + + + align:start position:0% +a sum of a bunch of different ks. But +for each one, I'd be taking some + + align:start position:0% +for each one, I'd be taking some + + + align:start position:0% +for each one, I'd be taking some +harmonic + + align:start position:0% +harmonic + + + align:start position:0% +harmonic +times the minus l har harmonic. + + align:start position:0% +times the minus l har harmonic. + + + align:start position:0% +times the minus l har harmonic. +And that's going to give me zero when I + + align:start position:0% +And that's going to give me zero when I + + + align:start position:0% +And that's going to give me zero when I +integrate over a period except when k + + align:start position:0% +integrate over a period except when k + + + align:start position:0% +integrate over a period except when k +equals l. + + align:start position:0% + + + + align:start position:0% + +If k equals l, then I'm going to get + + align:start position:0% +If k equals l, then I'm going to get + + + align:start position:0% +If k equals l, then I'm going to get +capital t. So the net effect of doing + + align:start position:0% +capital t. So the net effect of doing + + + align:start position:0% +capital t. So the net effect of doing +this is to to generate T A L. It sifts + + align:start position:0% +this is to to generate T A L. It sifts + + + align:start position:0% +this is to to generate T A L. It sifts +out one of those coefficients. + + align:start position:0% +out one of those coefficients. + + + align:start position:0% +out one of those coefficients. +Well, that's nice. That means that if I + + align:start position:0% +Well, that's nice. That means that if I + + + align:start position:0% +Well, that's nice. That means that if I +assume I can write the signal this way, + + align:start position:0% +assume I can write the signal this way, + + + align:start position:0% +assume I can write the signal this way, +then I can sift out the kith + + align:start position:0% +then I can sift out the kith + + + align:start position:0% +then I can sift out the kith +coefficient + + align:start position:0% +coefficient + + + align:start position:0% +coefficient +by integrating against minus the kith + + align:start position:0% +by integrating against minus the kith + + + align:start position:0% +by integrating against minus the kith +and divide by t because of the + + align:start position:0% +and divide by t because of the + + + align:start position:0% +and divide by t because of the +normalization because if you integrate + + align:start position:0% +normalization because if you integrate + + + align:start position:0% +normalization because if you integrate +one over a period, you get capital t. + + align:start position:0% +one over a period, you get capital t. + + + align:start position:0% +one over a period, you get capital t. +And that tells me then that if this were + + align:start position:0% +And that tells me then that if this were + + + align:start position:0% +And that tells me then that if this were +true, this is how you'd find the + + align:start position:0% +true, this is how you'd find the + + + align:start position:0% +true, this is how you'd find the +coefficient. + + align:start position:0% + + + + align:start position:0% + +So that leads to what we call a set of + + align:start position:0% +So that leads to what we call a set of + + + align:start position:0% +So that leads to what we call a set of +uh analysis and synthesis equations. + + align:start position:0% +uh analysis and synthesis equations. + + + align:start position:0% +uh analysis and synthesis equations. +So that if X can be represented this + + align:start position:0% +So that if X can be represented this + + + align:start position:0% +So that if X can be represented this +way, if we can synthesize + + align:start position:0% +way, if we can synthesize + + + align:start position:0% +way, if we can synthesize +a periodic signal X by adding together a + + align:start position:0% +a periodic signal X by adding together a + + + align:start position:0% +a periodic signal X by adding together a +bunch of harmonic components with a + + align:start position:0% +bunch of harmonic components with a + + + align:start position:0% +bunch of harmonic components with a +suitable waiting factor. The waiting + + align:start position:0% +suitable waiting factor. The waiting + + + align:start position:0% +suitable waiting factor. The waiting +factor a subk certainly has a different + + align:start position:0% +factor a subk certainly has a different + + + align:start position:0% +factor a subk certainly has a different +magnitude just like those musical tones + + align:start position:0% +magnitude just like those musical tones + + + align:start position:0% +magnitude just like those musical tones +that I played at the beginning, those + + align:start position:0% +that I played at the beginning, those + + + align:start position:0% +that I played at the beginning, those +musical notes. All the different ks had + + align:start position:0% +musical notes. All the different ks had + + + align:start position:0% +musical notes. All the different ks had +different amplitudes. They also have + + align:start position:0% +different amplitudes. They also have + + + align:start position:0% +different amplitudes. They also have +different phases. A subk can be a + + align:start position:0% +different phases. A subk can be a + + + align:start position:0% +different phases. A subk can be a +complex number. We like complex numbers. + + align:start position:0% +complex number. We like complex numbers. + + + align:start position:0% +complex number. We like complex numbers. +Complex numbers are easy. + + align:start position:0% +Complex numbers are easy. + + + align:start position:0% +Complex numbers are easy. +So uh if we can represent x by a sum of + + align:start position:0% +So uh if we can represent x by a sum of + + + align:start position:0% +So uh if we can represent x by a sum of +harmonics complex complex valued + + align:start position:0% +harmonics complex complex valued + + + align:start position:0% +harmonics complex complex valued +s uh so weighted by a complex number + + align:start position:0% +s uh so weighted by a complex number + + + align:start position:0% +s uh so weighted by a complex number +then we can sift out what those weight + + align:start position:0% +then we can sift out what those weight + + + align:start position:0% +then we can sift out what those weight +factors were by running the analysis + + align:start position:0% +factors were by running the analysis + + + align:start position:0% +factors were by running the analysis +equation. we can analyze the signal to + + align:start position:0% +equation. we can analyze the signal to + + + align:start position:0% +equation. we can analyze the signal to +figure out how much of the case + + align:start position:0% +figure out how much of the case + + + align:start position:0% +figure out how much of the case +component is there. + + align:start position:0% + + + + align:start position:0% + +So the strategy then is assume that all + + align:start position:0% +So the strategy then is assume that all + + + align:start position:0% +So the strategy then is assume that all +works. + + align:start position:0% +works. + + + align:start position:0% +works. +That is to say let's take an ugly signal + + align:start position:0% +That is to say let's take an ugly signal + + + align:start position:0% +That is to say let's take an ugly signal +of the type that caused controversy back + + align:start position:0% +of the type that caused controversy back + + + align:start position:0% +of the type that caused controversy back +in the mid 1800s. + + align:start position:0% +in the mid 1800s. + + + align:start position:0% +in the mid 1800s. +Let's take a controversial signal like a + + align:start position:0% +Let's take a controversial signal like a + + + align:start position:0% +Let's take a controversial signal like a +square wave. Assume it all works and + + align:start position:0% +square wave. Assume it all works and + + + align:start position:0% +square wave. Assume it all works and +figure out what the AKs would have had + + align:start position:0% +figure out what the AKs would have had + + + align:start position:0% +figure out what the AKs would have had +to be. and then we'll figure out whether + + align:start position:0% +to be. and then we'll figure out whether + + + align:start position:0% +to be. and then we'll figure out whether +that made any sense. + + align:start position:0% +that made any sense. + + + align:start position:0% +that made any sense. +So, + + align:start position:0% +So, + + + align:start position:0% +So, +uh if this thing were to be represented + + align:start position:0% +uh if this thing were to be represented + + + align:start position:0% +uh if this thing were to be represented +by a forier series by a a sum of + + align:start position:0% +by a forier series by a a sum of + + + align:start position:0% +by a forier series by a a sum of +harmonic components, + + align:start position:0% +harmonic components, + + + align:start position:0% +harmonic components, +how many of these statements would be + + align:start position:0% +how many of these statements would be + + + align:start position:0% +how many of these statements would be +true about those harmonic amplitudes? + + align:start position:0% + + + + align:start position:0% + +So, as you start to write, look toward + + align:start position:0% +So, as you start to write, look toward + + + align:start position:0% +So, as you start to write, look toward +your neighbor and say hi. + + align:start position:0% +your neighbor and say hi. + + + align:start position:0% +your neighbor and say hi. +Then write and figure out the answer. + + align:start position:0% + + + + align:start position:0% + +Okay. So, how many of those statements + + align:start position:0% +Okay. So, how many of those statements + + + align:start position:0% +Okay. So, how many of those statements +are true? Raise your hand with a number + + align:start position:0% +are true? Raise your hand with a number + + + align:start position:0% +are true? Raise your hand with a number +of fingers between zero and five would + + align:start position:0% +of fingers between zero and five would + + + align:start position:0% +of fingers between zero and five would +seem good limits. + + align:start position:0% +seem good limits. + + + align:start position:0% +seem good limits. +How many statements are true? + + align:start position:0% +How many statements are true? + + + align:start position:0% +How many statements are true? +Okay, we got about 40% correct. So, + + align:start position:0% +Okay, we got about 40% correct. So, + + + align:start position:0% +Okay, we got about 40% correct. So, +that's a little under half. What do I do + + align:start position:0% +that's a little under half. What do I do + + + align:start position:0% +that's a little under half. What do I do +first? + + align:start position:0% +first? + + + align:start position:0% +first? +If I want to figure this out, what would + + align:start position:0% +If I want to figure this out, what would + + + align:start position:0% +If I want to figure this out, what would +I do to try to figure out? So, statement + + align:start position:0% +I do to try to figure out? So, statement + + + align:start position:0% +I do to try to figure out? So, statement +one, a subk is zero if k is even. Should + + align:start position:0% +one, a subk is zero if k is even. Should + + + align:start position:0% +one, a subk is zero if k is even. Should +that be true or false? How do I think + + align:start position:0% +that be true or false? How do I think + + + align:start position:0% +that be true or false? How do I think +about that? + + align:start position:0% +about that? + + + align:start position:0% +about that? +Yeah. + + align:start position:0% + + + + align:start position:0% + +Square wave is odd. Okay, that sounds + + align:start position:0% +Square wave is odd. Okay, that sounds + + + align:start position:0% +Square wave is odd. Okay, that sounds +good. So, what's how's that help me? + + align:start position:0% + + + + align:start position:0% + +So, I might want to have only uh odd + + align:start position:0% +So, I might want to have only uh odd + + + align:start position:0% +So, I might want to have only uh odd +terms. How do I tell how many terms in + + align:start position:0% +terms. How do I tell how many terms in + + + align:start position:0% +terms. How do I tell how many terms in +the forier decomposition are odd and + + align:start position:0% +the forier decomposition are odd and + + + align:start position:0% +the forier decomposition are odd and +even? + + align:start position:0% +even? + + + align:start position:0% +even? +What is the forier decomposition? So + + align:start position:0% +What is the forier decomposition? So + + + align:start position:0% +What is the forier decomposition? So +let's start by just writing some + + align:start position:0% +let's start by just writing some + + + align:start position:0% +let's start by just writing some +definition, right? So I want to say that + + align:start position:0% +definition, right? So I want to say that + + + align:start position:0% +definition, right? So I want to say that +x of t + + align:start position:0% + + + + align:start position:0% + +is let's see I have a period of one. + + align:start position:0% +is let's see I have a period of one. + + + align:start position:0% +is let's see I have a period of one. +That's the same as x of t + one, right? + + align:start position:0% +That's the same as x of t + one, right? + + + align:start position:0% +That's the same as x of t + one, right? +And I want to write this as some sort of + + align:start position:0% +And I want to write this as some sort of + + + align:start position:0% +And I want to write this as some sort of +a forier thing. So what do I write next? + + align:start position:0% + + + + align:start position:0% + +Right? I want to say I want to say that + + align:start position:0% +Right? I want to say I want to say that + + + align:start position:0% +Right? I want to say I want to say that +this signal can be represented by some + + align:start position:0% +this signal can be represented by some + + + align:start position:0% +this signal can be represented by some +sum of something. Right? And I'm going + + align:start position:0% +sum of something. Right? And I'm going + + + align:start position:0% +sum of something. Right? And I'm going +to have to put some weights in. + + align:start position:0% +to have to put some weights in. + + + align:start position:0% +to have to put some weights in. +And I'm going to want something like e + + align:start position:0% +And I'm going to want something like e + + + align:start position:0% +And I'm going to want something like e +to the minus j 2 pi kt by t something + + align:start position:0% +to the minus j 2 pi kt by t something + + + align:start position:0% +to the minus j 2 pi kt by t something +like that. + + align:start position:0% +like that. + + + align:start position:0% +like that. +And I'm going to need a whole bunch of + + align:start position:0% +And I'm going to need a whole bunch of + + + align:start position:0% +And I'm going to need a whole bunch of +these. + + align:start position:0% +these. + + + align:start position:0% +these. +Where does even and odd show up? + + align:start position:0% + + + + align:start position:0% + +So if I were to rewrite this as ss and + + align:start position:0% +So if I were to rewrite this as ss and + + + align:start position:0% +So if I were to rewrite this as ss and +cosiness, right? So I could rewrite this + + align:start position:0% +cosiness, right? So I could rewrite this + + + align:start position:0% +cosiness, right? So I could rewrite this +in terms of some signs and some + + align:start position:0% +in terms of some signs and some + + + align:start position:0% +in terms of some signs and some +cosiness, + + align:start position:0% +cosiness, + + + align:start position:0% +cosiness, +then then the decomposition into even + + align:start position:0% +then then the decomposition into even + + + align:start position:0% +then then the decomposition into even +and odd is easier. That's correct. + + align:start position:0% +and odd is easier. That's correct. + + + align:start position:0% +and odd is easier. That's correct. +How do I So let's get back to this one. + + align:start position:0% +How do I So let's get back to this one. + + + align:start position:0% +How do I So let's get back to this one. +How do I think about this one now? Uh so + + align:start position:0% +How do I think about this one now? Uh so + + + align:start position:0% +How do I think about this one now? Uh so +I want k to be even. + + align:start position:0% +I want k to be even. + + + align:start position:0% +I want k to be even. +What does K even correspond to? + + align:start position:0% + + + + align:start position:0% + +Okay, let's assume I don't know what K + + align:start position:0% +Okay, let's assume I don't know what K + + + align:start position:0% +Okay, let's assume I don't know what K +even How do I do this if I don't know + + align:start position:0% +even How do I do this if I don't know + + + align:start position:0% +even How do I do this if I don't know +anything? How do I just uh grunt through + + align:start position:0% +anything? How do I just uh grunt through + + + align:start position:0% +anything? How do I just uh grunt through +it? + + align:start position:0% + + + + align:start position:0% + +Yeah, + + align:start position:0% +Yeah, + + + align:start position:0% +Yeah, +just do the integral. Exactly. So, what + + align:start position:0% +just do the integral. Exactly. So, what + + + align:start position:0% +just do the integral. Exactly. So, what +I'd like to do is say that uh a subk is + + align:start position:0% +I'd like to do is say that uh a subk is + + + align:start position:0% +I'd like to do is say that uh a subk is +one of So, assuming everything works, + + align:start position:0% +one of So, assuming everything works, + + + align:start position:0% +one of So, assuming everything works, +right? Assuming everything works, then a + + align:start position:0% +right? Assuming everything works, then a + + + align:start position:0% +right? Assuming everything works, then a +subk should be the integral over t + + align:start position:0% +subk should be the integral over t + + + align:start position:0% +subk should be the integral over t +weighted by 1 / t x of t e to the minus + + align:start position:0% +weighted by 1 / t x of t e to the minus + + + align:start position:0% +weighted by 1 / t x of t e to the minus +j 2 pi kt over t. I put a I should have + + align:start position:0% +j 2 pi kt over t. I put a I should have + + + align:start position:0% +j 2 pi kt over t. I put a I should have +put a plus there. + + align:start position:0% +put a plus there. + + + align:start position:0% +put a plus there. +Um I want the minus sign in one of the + + align:start position:0% +Um I want the minus sign in one of the + + + align:start position:0% +Um I want the minus sign in one of the +formulas and not in the other one. Okay. + + align:start position:0% +formulas and not in the other one. Okay. + + + align:start position:0% +formulas and not in the other one. Okay. +And if you just think about that that uh + + align:start position:0% +And if you just think about that that uh + + + align:start position:0% +And if you just think about that that uh +integral, it's not very hard. + + align:start position:0% +integral, it's not very hard. + + + align:start position:0% +integral, it's not very hard. +So I want this kind of thing. Capital T + + align:start position:0% +So I want this kind of thing. Capital T + + + align:start position:0% +So I want this kind of thing. Capital T +is one, right? + + align:start position:0% +is one, right? + + + align:start position:0% +is one, right? +So I get two pieces. The piece that + + align:start position:0% +So I get two pieces. The piece that + + + align:start position:0% +So I get two pieces. The piece that +corresponds to the minus a half and plus + + align:start position:0% +corresponds to the minus a half and plus + + + align:start position:0% +corresponds to the minus a half and plus +a half. + + align:start position:0% +a half. + + + align:start position:0% +a half. +And when I integrate them, I get + + align:start position:0% +And when I integrate them, I get + + + align:start position:0% +And when I integrate them, I get +something that's a little bit Well, no, + + align:start position:0% +something that's a little bit Well, no, + + + align:start position:0% +something that's a little bit Well, no, +it's pretty straightforward, right? So + + align:start position:0% +it's pretty straightforward, right? So + + + align:start position:0% +it's pretty straightforward, right? So +you integrate this thing, the one over + + align:start position:0% +you integrate this thing, the one over + + + align:start position:0% +you integrate this thing, the one over +minus, so the minus J2 pi K flips into + + align:start position:0% +minus, so the minus J2 pi K flips into + + + align:start position:0% +minus, so the minus J2 pi K flips into +the bottom. Uh the half turns it into J + + align:start position:0% +the bottom. Uh the half turns it into J + + + align:start position:0% +the bottom. Uh the half turns it into J +4 pi K blah blah blah. You get four + + align:start position:0% +4 pi K blah blah blah. You get four + + + align:start position:0% +4 pi K blah blah blah. You get four +pieces. two pieces. The these two pieces + + align:start position:0% +pieces. two pieces. The these two pieces + + + align:start position:0% +pieces. two pieces. The these two pieces +correspond to one. They sum to two. So + + align:start position:0% +correspond to one. They sum to two. So + + + align:start position:0% +correspond to one. They sum to two. So +you get that. + + align:start position:0% +you get that. + + + align:start position:0% +you get that. +The point is that it's a pretty simple + + align:start position:0% +The point is that it's a pretty simple + + + align:start position:0% +The point is that it's a pretty simple +it's a pretty simple transformation + + align:start position:0% +it's a pretty simple transformation + + + align:start position:0% +it's a pretty simple transformation +to think about the square wave turning + + align:start position:0% +to think about the square wave turning + + + align:start position:0% +to think about the square wave turning +into a sequence of amplitudes. + + align:start position:0% + + + + align:start position:0% + +So if you choose um let's see. So if you + + align:start position:0% +So if you choose um let's see. So if you + + + align:start position:0% +So if you choose um let's see. So if you +choose uh k to be even then I've got uh + + align:start position:0% +choose uh k to be even then I've got uh + + + align:start position:0% +choose uh k to be even then I've got uh +an integer multiple of 2 pi + + align:start position:0% +an integer multiple of 2 pi + + + align:start position:0% +an integer multiple of 2 pi +right if k were even then I would have + + align:start position:0% +right if k were even then I would have + + + align:start position:0% +right if k were even then I would have +uh an integer multiple of 2 pi e to the + + align:start position:0% +uh an integer multiple of 2 pi e to the + + + align:start position:0% +uh an integer multiple of 2 pi e to the +integer multiple of 2 pi flips around to + + align:start position:0% +integer multiple of 2 pi flips around to + + + align:start position:0% +integer multiple of 2 pi flips around to +one + + align:start position:0% +one + + + align:start position:0% +one +as does the minus one that kills this + + align:start position:0% +as does the minus one that kills this + + + align:start position:0% +as does the minus one that kills this +stuff. + + align:start position:0% +stuff. + + + align:start position:0% +stuff. +Okay, so that's where the K even and K + + align:start position:0% +Okay, so that's where the K even and K + + + align:start position:0% +Okay, so that's where the K even and K +odd comes from. + + align:start position:0% +odd comes from. + + + align:start position:0% +odd comes from. +So the point is that there's a simple + + align:start position:0% +So the point is that there's a simple + + + align:start position:0% +So the point is that there's a simple +way to to just crank through it and we + + align:start position:0% +way to to just crank through it and we + + + align:start position:0% +way to to just crank through it and we +get a a simple representation. So we get + + align:start position:0% +get a a simple representation. So we get + + + align:start position:0% +get a a simple representation. So we get +that AK is um 1 over J pi K + + align:start position:0% +that AK is um 1 over J pi K + + + align:start position:0% +that AK is um 1 over J pi K +uh K odd + + align:start position:0% +uh K odd + + + align:start position:0% +uh K odd +zero otherwise. + + align:start position:0% + + + + align:start position:0% + +Okay. And then we can just sort of t run + + align:start position:0% +Okay. And then we can just sort of t run + + + align:start position:0% +Okay. And then we can just sort of t run +down through the list. We'll see in a + + align:start position:0% +down through the list. We'll see in a + + + align:start position:0% +down through the list. We'll see in a +minute why this particular list of + + align:start position:0% +minute why this particular list of + + + align:start position:0% +minute why this particular list of +properties is interesting. So a a subk + + align:start position:0% +properties is interesting. So a a subk + + + align:start position:0% +properties is interesting. So a a subk +is zero if k is even. Yep. Right. + + align:start position:0% +is zero if k is even. Yep. Right. + + + align:start position:0% +is zero if k is even. Yep. Right. +Ak is real. Nope. There's a j in it. + + align:start position:0% +Ak is real. Nope. There's a j in it. + + + align:start position:0% +Ak is real. Nope. There's a j in it. +Uh a k magnitude decreases with k + + align:start position:0% +Uh a k magnitude decreases with k + + + align:start position:0% +Uh a k magnitude decreases with k +square. Nope. Decreases with k. + + align:start position:0% + + + + align:start position:0% + +Uh there's an infinite number of nonzero + + align:start position:0% +Uh there's an infinite number of nonzero + + + align:start position:0% +Uh there's an infinite number of nonzero +terms. Yep. Right. K goes to infinity. + + align:start position:0% +terms. Yep. Right. K goes to infinity. + + + align:start position:0% +terms. Yep. Right. K goes to infinity. +All of the above obvious. Okay. The + + align:start position:0% +All of the above obvious. Okay. The + + + align:start position:0% +All of the above obvious. Okay. The +point is it's simple to do and you end + + align:start position:0% +point is it's simple to do and you end + + + align:start position:0% +point is it's simple to do and you end +up representing the the uh + + align:start position:0% +up representing the the uh + + + align:start position:0% +up representing the the uh +time waveform + + align:start position:0% +time waveform + + + align:start position:0% +time waveform +by just a sequence of numbers. + + align:start position:0% +by just a sequence of numbers. + + + align:start position:0% +by just a sequence of numbers. +How big is the fundamental? How big is + + align:start position:0% +How big is the fundamental? How big is + + + align:start position:0% +How big is the fundamental? How big is +the second harmonic? How big is the + + align:start position:0% +the second harmonic? How big is the + + + align:start position:0% +the second harmonic? How big is the +third harmonic? Etc. + + align:start position:0% +third harmonic? Etc. + + + align:start position:0% +third harmonic? Etc. +There's some more math that makes things + + align:start position:0% +There's some more math that makes things + + + align:start position:0% +There's some more math that makes things +even easier. + + align:start position:0% +even easier. + + + align:start position:0% +even easier. +There are ways of thinking about + + align:start position:0% +There are ways of thinking about + + + align:start position:0% +There are ways of thinking about +operations in time + + align:start position:0% +operations in time + + + align:start position:0% +operations in time +as equivalent operations in harmonics. + + align:start position:0% +as equivalent operations in harmonics. + + + align:start position:0% +as equivalent operations in harmonics. +That makes the idea even more powerful + + align:start position:0% +That makes the idea even more powerful + + + align:start position:0% +That makes the idea even more powerful +because what we are developing is an + + align:start position:0% +because what we are developing is an + + + align:start position:0% +because what we are developing is an +alternative representation for signals. + + align:start position:0% +alternative representation for signals. + + + align:start position:0% +alternative representation for signals. +So same as we had multiple + + align:start position:0% +So same as we had multiple + + + align:start position:0% +So same as we had multiple +representations for systems, + + align:start position:0% +representations for systems, + + + align:start position:0% +representations for systems, +differential equations, block diagrams, + + align:start position:0% +differential equations, block diagrams, + + + align:start position:0% +differential equations, block diagrams, +h of t, h of s, h of r, bod plots, all + + align:start position:0% +h of t, h of s, h of r, bod plots, all + + + align:start position:0% +h of t, h of s, h of r, bod plots, all +those different representations of + + align:start position:0% +those different representations of + + + align:start position:0% +those different representations of +signal of systems. This represents an + + align:start position:0% +signal of systems. This represents an + + + align:start position:0% +signal of systems. This represents an +alternative representation of a signal. + + align:start position:0% +alternative representation of a signal. + + + align:start position:0% +alternative representation of a signal. +We think about it being represented in + + align:start position:0% +We think about it being represented in + + + align:start position:0% +We think about it being represented in +time or we will we think about it being + + align:start position:0% +time or we will we think about it being + + + align:start position:0% +time or we will we think about it being +represented in harmonics or eventually + + align:start position:0% +represented in harmonics or eventually + + + align:start position:0% +represented in harmonics or eventually +we'll call that frequency. So we'll + + align:start position:0% +we'll call that frequency. So we'll + + + align:start position:0% +we'll call that frequency. So we'll +think about signals being represented in + + align:start position:0% +think about signals being represented in + + + align:start position:0% +think about signals being represented in +time or frequency. And you can think + + align:start position:0% +time or frequency. And you can think + + + align:start position:0% +time or frequency. And you can think +about operations in time having a + + align:start position:0% +about operations in time having a + + + align:start position:0% +about operations in time having a +corresponding operation in frequency. + + align:start position:0% +corresponding operation in frequency. + + + align:start position:0% +corresponding operation in frequency. +So illustrated here, if a signal is + + align:start position:0% +So illustrated here, if a signal is + + + align:start position:0% +So illustrated here, if a signal is +differentiated in time, the 4A + + align:start position:0% +differentiated in time, the 4A + + + align:start position:0% +differentiated in time, the 4A +coefficients are multiplied by J 2 pi + + align:start position:0% +coefficients are multiplied by J 2 pi + + + align:start position:0% +coefficients are multiplied by J 2 pi +over T K. Okay. Well, that's easy. If we + + align:start position:0% +over T K. Okay. Well, that's easy. If we + + + align:start position:0% +over T K. Okay. Well, that's easy. If we +assume for the moment that we can + + align:start position:0% +assume for the moment that we can + + + align:start position:0% +assume for the moment that we can +represent X as this kind of a sum, + + align:start position:0% +represent X as this kind of a sum, + + + align:start position:0% +represent X as this kind of a sum, +differentiation is linear. The + + align:start position:0% +differentiation is linear. The + + + align:start position:0% +differentiation is linear. The +derivative of a sum is a sum of the + + align:start position:0% +derivative of a sum is a sum of the + + + align:start position:0% +derivative of a sum is a sum of the +derivatives. the derivative of sine + + align:start position:0% +derivatives. the derivative of sine + + + align:start position:0% +derivatives. the derivative of sine +waves easy and we end up with with the + + align:start position:0% +waves easy and we end up with with the + + + align:start position:0% +waves easy and we end up with with the +idea that if you knew the a subks + + align:start position:0% +idea that if you knew the a subks + + + align:start position:0% +idea that if you knew the a subks +then you can easily formulate the the u + + align:start position:0% +then you can easily formulate the the u + + + align:start position:0% +then you can easily formulate the the u +series representation + + align:start position:0% +series representation + + + align:start position:0% +series representation +for the harmonic structure by just + + align:start position:0% +for the harmonic structure by just + + + align:start position:0% +for the harmonic structure by just +multiplying each of the aks by the power + + align:start position:0% +multiplying each of the aks by the power + + + align:start position:0% +multiplying each of the aks by the power +of the exponent. + + align:start position:0% + + + + align:start position:0% + +Okay, so that gives us a way of thinking + + align:start position:0% +Okay, so that gives us a way of thinking + + + align:start position:0% +Okay, so that gives us a way of thinking +about signals in time + + align:start position:0% +about signals in time + + + align:start position:0% +about signals in time +as being represented in frequency. + + align:start position:0% +as being represented in frequency. + + + align:start position:0% +as being represented in frequency. +So here's an illustration of that. + + align:start position:0% +So here's an illustration of that. + + + align:start position:0% +So here's an illustration of that. +Imagine that we have a a triangle wave + + align:start position:0% +Imagine that we have a a triangle wave + + + align:start position:0% +Imagine that we have a a triangle wave +rather than a square wave. + + align:start position:0% + + + + align:start position:0% + +Answer the same questions and be aware + + align:start position:0% +Answer the same questions and be aware + + + align:start position:0% +Answer the same questions and be aware +that it's a trick. + + align:start position:0% + + + + align:start position:0% + +By trick I mean you could use the + + align:start position:0% +By trick I mean you could use the + + + align:start position:0% +By trick I mean you could use the +obvious approach which is one we just + + align:start position:0% +obvious approach which is one we just + + + align:start position:0% +obvious approach which is one we just +did or you could use some insight from + + align:start position:0% +did or you could use some insight from + + + align:start position:0% +did or you could use some insight from +the last slide and do it in one step. + + align:start position:0% + + + + align:start position:0% + +So, how many of these statements are + + align:start position:0% +So, how many of these statements are + + + align:start position:0% +So, how many of these statements are +true? + + align:start position:0% +true? + + + align:start position:0% +true? +Everybody raise your hand. raise a + + align:start position:0% +Everybody raise your hand. raise a + + + align:start position:0% +Everybody raise your hand. raise a +number of fingers + + align:start position:0% +number of fingers + + + align:start position:0% +number of fingers +equal to the U number of correct + + align:start position:0% +equal to the U number of correct + + + align:start position:0% +equal to the U number of correct +statements. We've got complete switch of + + align:start position:0% +statements. We've got complete switch of + + + align:start position:0% +statements. We've got complete switch of +who's right and still 40% correct. + + align:start position:0% +who's right and still 40% correct. + + + align:start position:0% +who's right and still 40% correct. +That's phenomenal. + + align:start position:0% +That's phenomenal. + + + align:start position:0% +That's phenomenal. +So, uh we could just go through the + + align:start position:0% +So, uh we could just go through the + + + align:start position:0% +So, uh we could just go through the +list. What's the trick? + + align:start position:0% + + + + align:start position:0% + +So close. So integral. Exactly. Right. + + align:start position:0% +So close. So integral. Exactly. Right. + + + align:start position:0% +So close. So integral. Exactly. Right. +This signal is the integral of the + + align:start position:0% +This signal is the integral of the + + + align:start position:0% +This signal is the integral of the +previous signal. Right. + + align:start position:0% +previous signal. Right. + + + align:start position:0% +previous signal. Right. +So that means that we ought to be able + + align:start position:0% +So that means that we ought to be able + + + align:start position:0% +So that means that we ought to be able +to there's some kind of a simple + + align:start position:0% +to there's some kind of a simple + + + align:start position:0% +to there's some kind of a simple +relationship between this series and the + + align:start position:0% +relationship between this series and the + + + align:start position:0% +relationship between this series and the +series that represents that one. What + + align:start position:0% +series that represents that one. What + + + align:start position:0% +series that represents that one. What +should I do to this one to make it look + + align:start position:0% +should I do to this one to make it look + + + align:start position:0% +should I do to this one to make it look +like that one? + + align:start position:0% + + + + align:start position:0% + +Divide by J2 K precisely. + + align:start position:0% +Divide by J2 K precisely. + + + align:start position:0% +Divide by J2 K precisely. +So um I can think about the bks being + + align:start position:0% +So um I can think about the bks being + + + align:start position:0% +So um I can think about the bks being +the aks + + align:start position:0% +the aks + + + align:start position:0% +the aks +but then I have to worry about the + + align:start position:0% +but then I have to worry about the + + + align:start position:0% +but then I have to worry about the +representation for differentiation or + + align:start position:0% +representation for differentiation or + + + align:start position:0% +representation for differentiation or +here integration + + align:start position:0% +here integration + + + align:start position:0% +here integration +in the frequency domain. In the + + align:start position:0% +in the frequency domain. In the + + + align:start position:0% +in the frequency domain. In the +frequency domain integration + + align:start position:0% +frequency domain integration + + + align:start position:0% +frequency domain integration +corresponds to dividing by uh J2 pi k. + + align:start position:0% +corresponds to dividing by uh J2 pi k. + + + align:start position:0% +corresponds to dividing by uh J2 pi k. +So now uh if I think about the list of + + align:start position:0% +So now uh if I think about the list of + + + align:start position:0% +So now uh if I think about the list of +questions uh is b zero for k even? Yeah, + + align:start position:0% +questions uh is b zero for k even? Yeah, + + + align:start position:0% +questions uh is b zero for k even? Yeah, +it was before. It is now + + align:start position:0% +it was before. It is now + + + align:start position:0% +it was before. It is now +because all we're doing is changing the + + align:start position:0% +because all we're doing is changing the + + + align:start position:0% +because all we're doing is changing the +the weights. And if the weights started + + align:start position:0% +the weights. And if the weights started + + + align:start position:0% +the weights. And if the weights started +out zero and we're multiplying by + + align:start position:0% +out zero and we're multiplying by + + + align:start position:0% +out zero and we're multiplying by +something, we can't get it to be + + align:start position:0% +something, we can't get it to be + + + align:start position:0% +something, we can't get it to be +different from zero. + + align:start position:0% +different from zero. + + + align:start position:0% +different from zero. +Uh, is it real valued? Well, now it is + + align:start position:0% +Uh, is it real valued? Well, now it is + + + align:start position:0% +Uh, is it real valued? Well, now it is +because I had a J time J. + + align:start position:0% +because I had a J time J. + + + align:start position:0% +because I had a J time J. +So now they are real real valued. + + align:start position:0% +So now they are real real valued. + + + align:start position:0% +So now they are real real valued. +Uh, does it decrease with K square? Now + + align:start position:0% +Uh, does it decrease with K square? Now + + + align:start position:0% +Uh, does it decrease with K square? Now +it does because I got one of the K's + + align:start position:0% +it does because I got one of the K's + + + align:start position:0% +it does because I got one of the K's +from the differentiation operator and + + align:start position:0% +from the differentiation operator and + + + align:start position:0% +from the differentiation operator and +the other K from over here. + + align:start position:0% +the other K from over here. + + + align:start position:0% +the other K from over here. +uh infinite number. Of course, the old + + align:start position:0% +uh infinite number. Of course, the old + + + align:start position:0% +uh infinite number. Of course, the old +one did too. All of the above. Yes. + + align:start position:0% +one did too. All of the above. Yes. + + + align:start position:0% +one did too. All of the above. Yes. +Okay. So, that was just supposed to be a + + align:start position:0% +Okay. So, that was just supposed to be a + + + align:start position:0% +Okay. So, that was just supposed to be a +simple exercise in in how to run the + + align:start position:0% +simple exercise in in how to run the + + + align:start position:0% +simple exercise in in how to run the +formulas, how to do this stuff um from a + + align:start position:0% +formulas, how to do this stuff um from a + + + align:start position:0% +formulas, how to do this stuff um from a +purely mechanical point of view. Now, I + + align:start position:0% +purely mechanical point of view. Now, I + + + align:start position:0% +purely mechanical point of view. Now, I +want to think about the bigger question. + + align:start position:0% +want to think about the bigger question. + + + align:start position:0% +want to think about the bigger question. +Does any of this make any sense? + + align:start position:0% +Does any of this make any sense? + + + align:start position:0% +Does any of this make any sense? +And the answers were concocted to help + + align:start position:0% +And the answers were concocted to help + + + align:start position:0% +And the answers were concocted to help +me make sense of that. The questions, + + align:start position:0% +me make sense of that. The questions, + + + align:start position:0% +me make sense of that. The questions, +the check yourselves were concocted so + + align:start position:0% +the check yourselves were concocted so + + + align:start position:0% +the check yourselves were concocted so +that if we think about the answer that + + align:start position:0% +that if we think about the answer that + + + align:start position:0% +that if we think about the answer that +came out, we'll have some insight into + + align:start position:0% +came out, we'll have some insight into + + + align:start position:0% +came out, we'll have some insight into +why we think it works and why it was + + align:start position:0% +why we think it works and why it was + + + align:start position:0% +why we think it works and why it was +controversial 150 years ago. + + align:start position:0% +controversial 150 years ago. + + + align:start position:0% +controversial 150 years ago. +So let's do the simple case first. Even + + align:start position:0% +So let's do the simple case first. Even + + + align:start position:0% +So let's do the simple case first. Even +Lrange wouldn't have any trouble with + + align:start position:0% +Lrange wouldn't have any trouble with + + + align:start position:0% +Lrange wouldn't have any trouble with +this way. Well, maybe he would have had + + align:start position:0% +this way. Well, maybe he would have had + + + align:start position:0% +this way. Well, maybe he would have had +a little trouble. I guess he would have + + align:start position:0% +a little trouble. I guess he would have + + + align:start position:0% +a little trouble. I guess he would have +had a little trouble. So, Lrange had the + + align:start position:0% +had a little trouble. So, Lrange had the + + + align:start position:0% +had a little trouble. So, Lrange had the +problem with Forier that Forier was + + align:start position:0% +problem with Forier that Forier was + + + align:start position:0% +problem with Forier that Forier was +making these outrageous claims that any + + align:start position:0% +making these outrageous claims that any + + + align:start position:0% +making these outrageous claims that any +periodic function should have a Forier + + align:start position:0% +periodic function should have a Forier + + + align:start position:0% +periodic function should have a Forier +decomposition and if you have uh + + align:start position:0% +decomposition and if you have uh + + + align:start position:0% +decomposition and if you have uh +discontinuous function and if all the + + align:start position:0% +discontinuous function and if all the + + + align:start position:0% +discontinuous function and if all the +basis functions are continuous, how + + align:start position:0% +basis functions are continuous, how + + + align:start position:0% +basis functions are continuous, how +could that make any sense, right? This + + align:start position:0% +could that make any sense, right? This + + + align:start position:0% +could that make any sense, right? This +doesn't have any discontinuities, but it + + align:start position:0% +doesn't have any discontinuities, but it + + + align:start position:0% +doesn't have any discontinuities, but it +does have slope discontinuities. + + align:start position:0% + + + + align:start position:0% + +That's sort of the same thing, right? If + + align:start position:0% +That's sort of the same thing, right? If + + + align:start position:0% +That's sort of the same thing, right? If +you have a slope discontinuity and + + align:start position:0% +you have a slope discontinuity and + + + align:start position:0% +you have a slope discontinuity and +you're trying to make u you're trying to + + align:start position:0% +you're trying to make u you're trying to + + + align:start position:0% +you're trying to make u you're trying to +represent the signal by a sum of signals + + align:start position:0% +represent the signal by a sum of signals + + + align:start position:0% +represent the signal by a sum of signals +none of whom have slope discontinuities + + align:start position:0% +none of whom have slope discontinuities + + + align:start position:0% +none of whom have slope discontinuities +that's kind of the same kind of problem. + + align:start position:0% +that's kind of the same kind of problem. + + + align:start position:0% +that's kind of the same kind of problem. +One way we can think about it is to + + align:start position:0% +One way we can think about it is to + + + align:start position:0% +One way we can think about it is to +think about how the approximation gets + + align:start position:0% +think about how the approximation gets + + + align:start position:0% +think about how the approximation gets +better or fails to get better as we add + + align:start position:0% +better or fails to get better as we add + + + align:start position:0% +better or fails to get better as we add +terms. So this is the base function. + + align:start position:0% +terms. So this is the base function. + + + align:start position:0% +terms. So this is the base function. +This is how the signal that we would + + align:start position:0% +This is how the signal that we would + + + align:start position:0% +This is how the signal that we would +like to represent harmonically. If we + + align:start position:0% +like to represent harmonically. If we + + + align:start position:0% +like to represent harmonically. If we +just think about the first nonzero term, + + align:start position:0% +just think about the first nonzero term, + + + align:start position:0% +just think about the first nonzero term, +the first nonzero term is the + + align:start position:0% +the first nonzero term is the + + + align:start position:0% +the first nonzero term is the +fundamental. It actually is not bad, + + align:start position:0% +fundamental. It actually is not bad, + + + align:start position:0% +fundamental. It actually is not bad, +right? If we were willing to accept + + align:start position:0% +right? If we were willing to accept + + + align:start position:0% +right? If we were willing to accept +errors about this big, it would be okay. + + align:start position:0% +errors about this big, it would be okay. + + + align:start position:0% +errors about this big, it would be okay. +Okay. Well, but somehow it doesn't + + align:start position:0% +Okay. Well, but somehow it doesn't + + + align:start position:0% +Okay. Well, but somehow it doesn't +capture much trianguliness, + + align:start position:0% +capture much trianguliness, + + + align:start position:0% +capture much trianguliness, +right? it sort of doesn't look much like + + align:start position:0% +right? it sort of doesn't look much like + + + align:start position:0% +right? it sort of doesn't look much like +even though so the one term sort of + + align:start position:0% +even though so the one term sort of + + + align:start position:0% +even though so the one term sort of +catches a lot of the deviation but it + + align:start position:0% +catches a lot of the deviation but it + + + align:start position:0% +catches a lot of the deviation but it +doesn't capture the the triangle aspect + + align:start position:0% +doesn't capture the the triangle aspect + + + align:start position:0% +doesn't capture the the triangle aspect +if you add another term the next nonzero + + align:start position:0% +if you add another term the next nonzero + + + align:start position:0% +if you add another term the next nonzero +term is the third one so if you write + + align:start position:0% +term is the third one so if you write + + + align:start position:0% +term is the third one so if you write +the sum of the first term the k equals 1 + + align:start position:0% +the sum of the first term the k equals 1 + + + align:start position:0% +the sum of the first term the k equals 1 +term and the k= 3 term you get this + + align:start position:0% +term and the k= 3 term you get this + + + align:start position:0% +term and the k= 3 term you get this +waveform + + align:start position:0% +waveform + + + align:start position:0% +waveform +notice that the effect of that was to + + align:start position:0% +notice that the effect of that was to + + + align:start position:0% +notice that the effect of that was to +creep it toward the underlying signal if + + align:start position:0% +creep it toward the underlying signal if + + + align:start position:0% +creep it toward the underlying signal if +you add another term Five, seven, nine. + + align:start position:0% +you add another term Five, seven, nine. + + + align:start position:0% +you add another term Five, seven, nine. +It's getting closer, closer, closer. + + align:start position:0% +It's getting closer, closer, closer. + + + align:start position:0% +It's getting closer, closer, closer. +19 because I got bored making the + + align:start position:0% +19 because I got bored making the + + + align:start position:0% +19 because I got bored making the +figures, right? So, I skipped a bunch. + + align:start position:0% +figures, right? So, I skipped a bunch. + + + align:start position:0% +figures, right? So, I skipped a bunch. +29 because I skipped a bunch. + + align:start position:0% +29 because I skipped a bunch. + + + align:start position:0% +29 because I skipped a bunch. +39. You can see that what's happening is + + align:start position:0% +39. You can see that what's happening is + + + align:start position:0% +39. You can see that what's happening is +that we as we add more and more of those + + align:start position:0% +that we as we add more and more of those + + + align:start position:0% +that we as we add more and more of those +terms, by the time we've got up to + + align:start position:0% +terms, by the time we've got up to + + + align:start position:0% +terms, by the time we've got up to +number 39, it's pretty good. So, that + + align:start position:0% +number 39, it's pretty good. So, that + + + align:start position:0% +number 39, it's pretty good. So, that +probably from your seat, it's not + + align:start position:0% +probably from your seat, it's not + + + align:start position:0% +probably from your seat, it's not +altogether apparent that they're + + align:start position:0% +altogether apparent that they're + + + align:start position:0% +altogether apparent that they're +different. They're still different, + + align:start position:0% +different. They're still different, + + + align:start position:0% +different. They're still different, +right? But you can see that there's a + + align:start position:0% +right? But you can see that there's a + + + align:start position:0% +right? But you can see that there's a +sense + + align:start position:0% +sense + + + align:start position:0% +sense +in which the approximation is converging + + align:start position:0% +in which the approximation is converging + + + align:start position:0% +in which the approximation is converging +toward the underlying signal. + + align:start position:0% +toward the underlying signal. + + + align:start position:0% +toward the underlying signal. +That's good. So that's a sense in which + + align:start position:0% +That's good. So that's a sense in which + + + align:start position:0% +That's good. So that's a sense in which +there's a convergence between the signal + + align:start position:0% +there's a convergence between the signal + + + align:start position:0% +there's a convergence between the signal +and its forier representation. + + align:start position:0% + + + + align:start position:0% + +A different kind of thing happens here. + + align:start position:0% +A different kind of thing happens here. + + + align:start position:0% +A different kind of thing happens here. +Now let's do the square wave. + + align:start position:0% +Now let's do the square wave. + + + align:start position:0% +Now let's do the square wave. +If we put in the first term of the + + align:start position:0% +If we put in the first term of the + + + align:start position:0% +If we put in the first term of the +forier representation, which is the + + align:start position:0% +forier representation, which is the + + + align:start position:0% +forier representation, which is the +fundamental, we get a sine wave + + align:start position:0% +fundamental, we get a sine wave + + + align:start position:0% +fundamental, we get a sine wave +approximation, which is a little worse + + align:start position:0% +approximation, which is a little worse + + + align:start position:0% +approximation, which is a little worse +perhaps for a square wave than it was + + align:start position:0% +perhaps for a square wave than it was + + + align:start position:0% +perhaps for a square wave than it was +for a triangle wave. + + align:start position:0% +for a triangle wave. + + + align:start position:0% +for a triangle wave. +put in the third, fifth, 7th, 9th, + + align:start position:0% +put in the third, fifth, 7th, 9th, + + + align:start position:0% +put in the third, fifth, 7th, 9th, +19th. So that's the So I threw in five + + align:start position:0% +19th. So that's the So I threw in five + + + align:start position:0% +19th. So that's the So I threw in five +again. + + align:start position:0% +again. + + + align:start position:0% +again. +29, + + align:start position:0% +29, + + + align:start position:0% +29, +39. + + align:start position:0% +39. + + + align:start position:0% +39. +It's not doing as well. What's not doing + + align:start position:0% +It's not doing as well. What's not doing + + + align:start position:0% +It's not doing as well. What's not doing +as well? + + align:start position:0% + + + + align:start position:0% + +Right. So we go one one term partial sum + + align:start position:0% +Right. So we go one one term partial sum + + + align:start position:0% +Right. So we go one one term partial sum +two three four five + + align:start position:0% +two three four five + + + align:start position:0% +two three four five +20 uh 10 15 20 + + align:start position:0% +20 uh 10 15 20 + + + align:start position:0% +20 uh 10 15 20 +yeah + + align:start position:0% + + + + align:start position:0% + +really quick transitions not able to + + align:start position:0% +really quick transitions not able to + + + align:start position:0% +really quick transitions not able to +handle the really quick transition it's + + align:start position:0% +handle the really quick transition it's + + + align:start position:0% +handle the really quick transition it's +kind of like Lrange said right how are + + align:start position:0% +kind of like Lrange said right how are + + + align:start position:0% +kind of like Lrange said right how are +you going to make a discontinuous + + align:start position:0% +you going to make a discontinuous + + + align:start position:0% +you going to make a discontinuous +function out of a sum of continuous ones + + align:start position:0% +function out of a sum of continuous ones + + + align:start position:0% +function out of a sum of continuous ones +right it's + + align:start position:0% +right it's + + + align:start position:0% +right it's +In fact, um this is called Gibbs + + align:start position:0% +In fact, um this is called Gibbs + + + align:start position:0% +In fact, um this is called Gibbs +phenomena after the guy who sort of + + align:start position:0% +phenomena after the guy who sort of + + + align:start position:0% +phenomena after the guy who sort of +formulated the mathematics of this. + + align:start position:0% +formulated the mathematics of this. + + + align:start position:0% +formulated the mathematics of this. +There's even in the limit, no matter how + + align:start position:0% +There's even in the limit, no matter how + + + align:start position:0% +There's even in the limit, no matter how +many terms you put into the sum, + + align:start position:0% +many terms you put into the sum, + + + align:start position:0% +many terms you put into the sum, +the worstcase deviation is about 9%. + + align:start position:0% +the worstcase deviation is about 9%. + + + align:start position:0% +the worstcase deviation is about 9%. +You can't get rid of it. So in some + + align:start position:0% +You can't get rid of it. So in some + + + align:start position:0% +You can't get rid of it. So in some +sense, + + align:start position:0% +sense, + + + align:start position:0% +sense, +Lrange is right. Right. You can't put + + align:start position:0% +Lrange is right. Right. You can't put + + + align:start position:0% +Lrange is right. Right. You can't put +enough terms in there so that it + + align:start position:0% +enough terms in there so that it + + + align:start position:0% +enough terms in there so that it +converges everywhere. + + align:start position:0% +converges everywhere. + + + align:start position:0% +converges everywhere. +Okay. So the problem then becomes that + + align:start position:0% +Okay. So the problem then becomes that + + + align:start position:0% +Okay. So the problem then becomes that +we can't really think about convergence + + align:start position:0% +we can't really think about convergence + + + align:start position:0% +we can't really think about convergence +in the familiar ways we like to think + + align:start position:0% +in the familiar ways we like to think + + + align:start position:0% +in the familiar ways we like to think +about convergence. Convergence at a + + align:start position:0% +about convergence. Convergence at a + + + align:start position:0% +about convergence. Convergence at a +point is not a good way to think about + + align:start position:0% +point is not a good way to think about + + + align:start position:0% +point is not a good way to think about +it because there's always a point that + + align:start position:0% +it because there's always a point that + + + align:start position:0% +it because there's always a point that +deviates a lot. + + align:start position:0% +deviates a lot. + + + align:start position:0% +deviates a lot. +And in fact in signal processing we have + + align:start position:0% +And in fact in signal processing we have + + + align:start position:0% +And in fact in signal processing we have +lots of other ways we think about + + align:start position:0% +lots of other ways we think about + + + align:start position:0% +lots of other ways we think about +convergence if you think about so in + + align:start position:0% +convergence if you think about so in + + + align:start position:0% +convergence if you think about so in +addition to being 9% overshoot the Gibbs + + align:start position:0% +addition to being 9% overshoot the Gibbs + + + align:start position:0% +addition to being 9% overshoot the Gibbs +phenomenon + + align:start position:0% +phenomenon + + + align:start position:0% +phenomenon +what else do you see as the trend as you + + align:start position:0% +what else do you see as the trend as you + + + align:start position:0% +what else do you see as the trend as you +increase the number of terms in the + + align:start position:0% +increase the number of terms in the + + + align:start position:0% +increase the number of terms in the +partial sum + + align:start position:0% + + + + align:start position:0% + +in addition to converging and staying + + align:start position:0% +in addition to converging and staying + + + align:start position:0% +in addition to converging and staying +sort of the same height eight. + + align:start position:0% +sort of the same height eight. + + + align:start position:0% +sort of the same height eight. +What else happened as I added terms to + + align:start position:0% +What else happened as I added terms to + + + align:start position:0% +What else happened as I added terms to +the partial sum + + align:start position:0% + + + + align:start position:0% + +got skinnier. + + align:start position:0% + + + + align:start position:0% + +The deviations got crammed toward the + + align:start position:0% +The deviations got crammed toward the + + + align:start position:0% +The deviations got crammed toward the +transition point. + + align:start position:0% +transition point. + + + align:start position:0% +transition point. +And if I keep adding them, they'll get + + align:start position:0% +And if I keep adding them, they'll get + + + align:start position:0% +And if I keep adding them, they'll get +crammed more and more in there. + + align:start position:0% +crammed more and more in there. + + + align:start position:0% +crammed more and more in there. +And it's not like an impulse, right? The + + align:start position:0% +And it's not like an impulse, right? The + + + align:start position:0% +And it's not like an impulse, right? The +height didn't get bigger. The width got + + align:start position:0% +height didn't get bigger. The width got + + + align:start position:0% +height didn't get bigger. The width got +smaller. + + align:start position:0% +smaller. + + + align:start position:0% +smaller. +Had the height got bigger, we'd have + + align:start position:0% +Had the height got bigger, we'd have + + + align:start position:0% +Had the height got bigger, we'd have +been in trouble + + align:start position:0% +been in trouble + + + align:start position:0% +been in trouble +because then we would have said it + + align:start position:0% +because then we would have said it + + + align:start position:0% +because then we would have said it +deviates from the square wave by having + + align:start position:0% +deviates from the square wave by having + + + align:start position:0% +deviates from the square wave by having +an impulse at the transition. It doesn't + + align:start position:0% +an impulse at the transition. It doesn't + + + align:start position:0% +an impulse at the transition. It doesn't +have an impulse. The height staying the + + align:start position:0% +have an impulse. The height staying the + + + align:start position:0% +have an impulse. The height staying the +same, the width is smashing towards + + align:start position:0% +same, the width is smashing towards + + + align:start position:0% +same, the width is smashing towards +zero. The energy in that signal is + + align:start position:0% +zero. The energy in that signal is + + + align:start position:0% +zero. The energy in that signal is +getting smaller and smaller. So we like + + align:start position:0% +getting smaller and smaller. So we like + + + align:start position:0% +getting smaller and smaller. So we like +to think about so a different way to + + align:start position:0% +to think about so a different way to + + + align:start position:0% +to think about so a different way to +think about convergence is how big is + + align:start position:0% +think about convergence is how big is + + + align:start position:0% +think about convergence is how big is +the energy difference between the two + + align:start position:0% +the energy difference between the two + + + align:start position:0% +the energy difference between the two +signals. + + align:start position:0% +signals. + + + align:start position:0% +signals. +In that sense, this converges in 4A's + + align:start position:0% +In that sense, this converges in 4A's + + + align:start position:0% +In that sense, this converges in 4A's +right. + + align:start position:0% +right. + + + align:start position:0% +right. +As you add terms, the energy difference + + align:start position:0% +As you add terms, the energy difference + + + align:start position:0% +As you add terms, the energy difference +between the two signals goes to zero. + + align:start position:0% +between the two signals goes to zero. + + + align:start position:0% +between the two signals goes to zero. +That's the that's the modern way of + + align:start position:0% +That's the that's the modern way of + + + align:start position:0% +That's the that's the modern way of +thinking about the controversy. Right? + + align:start position:0% +thinking about the controversy. Right? + + + align:start position:0% +thinking about the controversy. Right? +There is an issue, right? If we choose + + align:start position:0% +There is an issue, right? If we choose + + + align:start position:0% +There is an issue, right? If we choose +to think about convergence in terms of + + align:start position:0% +to think about convergence in terms of + + + align:start position:0% +to think about convergence in terms of +uh energy difference, then we can + + align:start position:0% +uh energy difference, then we can + + + align:start position:0% +uh energy difference, then we can +resolve the problem. That's what we'll + + align:start position:0% +resolve the problem. That's what we'll + + + align:start position:0% +resolve the problem. That's what we'll +do. + + align:start position:0% +do. + + + align:start position:0% +do. +That's the reason in lots of the things + + align:start position:0% +That's the reason in lots of the things + + + align:start position:0% +That's the reason in lots of the things +that we talk about, we haven't been too + + align:start position:0% +that we talk about, we haven't been too + + + align:start position:0% +that we talk about, we haven't been too +worried about single points being off of + + align:start position:0% +worried about single points being off of + + + align:start position:0% +worried about single points being off of +curves. + + align:start position:0% +curves. + + + align:start position:0% +curves. +That's come up in some of the homeworks + + align:start position:0% +That's come up in some of the homeworks + + + align:start position:0% +That's come up in some of the homeworks +that we don't really care too much that + + align:start position:0% +that we don't really care too much that + + + align:start position:0% +that we don't really care too much that +say you have a function that is one + + align:start position:0% +say you have a function that is one + + + align:start position:0% +say you have a function that is one +everywhere except one point. + + align:start position:0% +everywhere except one point. + + + align:start position:0% +everywhere except one point. +There's no energy difference between the + + align:start position:0% +There's no energy difference between the + + + align:start position:0% +There's no energy difference between the +signal that differs by one point and the + + align:start position:0% +signal that differs by one point and the + + + align:start position:0% +signal that differs by one point and the +original, + + align:start position:0% + + + + align:start position:0% + +right? has a finite height, but there's + + align:start position:0% +right? has a finite height, but there's + + + align:start position:0% +right? has a finite height, but there's +zero width, so there's no energy + + align:start position:0% +zero width, so there's no energy + + + align:start position:0% +zero width, so there's no energy +difference. So we So that's the reason + + align:start position:0% +difference. So we So that's the reason + + + align:start position:0% +difference. So we So that's the reason +we haven't been so worried about that + + align:start position:0% +we haven't been so worried about that + + + align:start position:0% +we haven't been so worried about that +because we we use this kind of a + + align:start position:0% +because we we use this kind of a + + + align:start position:0% +because we we use this kind of a +definition of equality. They're equal if + + align:start position:0% +definition of equality. They're equal if + + + align:start position:0% +definition of equality. They're equal if +there's no energy difference between + + align:start position:0% +there's no energy difference between + + + align:start position:0% +there's no energy difference between +them. + + align:start position:0% +them. + + + align:start position:0% +them. +Okay? And using that kind of a way of + + align:start position:0% +Okay? And using that kind of a way of + + + align:start position:0% +Okay? And using that kind of a way of +thinking about things, we get to write + + align:start position:0% +thinking about things, we get to write + + + align:start position:0% +thinking about things, we get to write +FRA uh decompositions, harmonic + + align:start position:0% +FRA uh decompositions, harmonic + + + align:start position:0% +FRA uh decompositions, harmonic +decompositions for a wide range of + + align:start position:0% +decompositions for a wide range of + + + align:start position:0% +decompositions for a wide range of +signals, not all of them, right? for EA + + align:start position:0% +signals, not all of them, right? for EA + + + align:start position:0% +signals, not all of them, right? for EA +exaggerated + + align:start position:0% +exaggerated + + + align:start position:0% +exaggerated +but for a wide range of signals in fact + + align:start position:0% +but for a wide range of signals in fact + + + align:start position:0% +but for a wide range of signals in fact +with the definition we will typically + + align:start position:0% +with the definition we will typically + + + align:start position:0% +with the definition we will typically +use is signals with finite energy + + align:start position:0% +use is signals with finite energy + + + align:start position:0% +use is signals with finite energy +we'll be able to do this + + align:start position:0% +we'll be able to do this + + + align:start position:0% +we'll be able to do this +so now what I want to do is the last + + align:start position:0% +so now what I want to do is the last + + + align:start position:0% +so now what I want to do is the last +part of this lecture I want to introduce + + align:start position:0% +part of this lecture I want to introduce + + + align:start position:0% +part of this lecture I want to introduce +how thinking about a signal in terms of + + align:start position:0% +how thinking about a signal in terms of + + + align:start position:0% +how thinking about a signal in terms of +its harmonic structure lets us think + + align:start position:0% +its harmonic structure lets us think + + + align:start position:0% +its harmonic structure lets us think +about systems differently + + align:start position:0% +about systems differently + + + align:start position:0% +about systems differently +so here the idea is we previously + + align:start position:0% +so here the idea is we previously + + + align:start position:0% +so here the idea is we previously +thought about systems as frequency + + align:start position:0% +thought about systems as frequency + + + align:start position:0% +thought about systems as frequency +responses. In a frequency response, we + + align:start position:0% +responses. In a frequency response, we + + + align:start position:0% +responses. In a frequency response, we +use the igen function property. You put + + align:start position:0% +use the igen function property. You put + + + align:start position:0% +use the igen function property. You put +in an igen function, one of these + + align:start position:0% +in an igen function, one of these + + + align:start position:0% +in an igen function, one of these +complex exponentials, you get out the + + align:start position:0% +complex exponentials, you get out the + + + align:start position:0% +complex exponentials, you get out the +same complex exponential if the system + + align:start position:0% +same complex exponential if the system + + + align:start position:0% +same complex exponential if the system +is linear time invariant. + + align:start position:0% +is linear time invariant. + + + align:start position:0% +is linear time invariant. +And the igen value is the value of the + + align:start position:0% +And the igen value is the value of the + + + align:start position:0% +And the igen value is the value of the +system function evaluated the frequency + + align:start position:0% +system function evaluated the frequency + + + align:start position:0% +system function evaluated the frequency +of interest. We've done that before. + + align:start position:0% +of interest. We've done that before. + + + align:start position:0% +of interest. We've done that before. +The neat thing that happens if you think + + align:start position:0% +The neat thing that happens if you think + + + align:start position:0% +The neat thing that happens if you think +about for series is that you can break + + align:start position:0% +about for series is that you can break + + + align:start position:0% +about for series is that you can break +down the input into a a sum of discrete + + align:start position:0% +down the input into a a sum of discrete + + + align:start position:0% +down the input into a a sum of discrete +parts. the first harmonic, the zero + + align:start position:0% +parts. the first harmonic, the zero + + + align:start position:0% +parts. the first harmonic, the zero +harmonic, the second harmonic, the third + + align:start position:0% +harmonic, the second harmonic, the third + + + align:start position:0% +harmonic, the second harmonic, the third +harmonic. And now each one of those + + align:start position:0% +harmonic. And now each one of those + + + align:start position:0% +harmonic. And now each one of those +parts was an igen function. And each one + + align:start position:0% +parts was an igen function. And each one + + + align:start position:0% +parts was an igen function. And each one +of those parts gets preferentially + + align:start position:0% +of those parts gets preferentially + + + align:start position:0% +of those parts gets preferentially +amplified + + align:start position:0% +amplified + + + align:start position:0% +amplified +andor time delayed according to the the + + align:start position:0% +andor time delayed according to the the + + + align:start position:0% +andor time delayed according to the the +um frequency response idea for the + + align:start position:0% +um frequency response idea for the + + + align:start position:0% +um frequency response idea for the +system. + + align:start position:0% +system. + + + align:start position:0% +system. +That lets us think about the effect of a + + align:start position:0% +That lets us think about the effect of a + + + align:start position:0% +That lets us think about the effect of a +system is to filter the input. So the + + align:start position:0% +system is to filter the input. So the + + + align:start position:0% +system is to filter the input. So the +system u the idea in a filter is that + + align:start position:0% +system u the idea in a filter is that + + + align:start position:0% +system u the idea in a filter is that +systems do not LTI systems linear time + + align:start position:0% +systems do not LTI systems linear time + + + align:start position:0% +systems do not LTI systems linear time +invariant systems the same kind of + + align:start position:0% +invariant systems the same kind of + + + align:start position:0% +invariant systems the same kind of +systems that we've been thinking about + + align:start position:0% +systems that we've been thinking about + + + align:start position:0% +systems that we've been thinking about +all along so far linear time invariant + + align:start position:0% +all along so far linear time invariant + + + align:start position:0% +all along so far linear time invariant +systems cannot create new frequencies. + + align:start position:0% + + + + align:start position:0% + +If you put some frequency in that's the + + align:start position:0% +If you put some frequency in that's the + + + align:start position:0% +If you put some frequency in that's the +frequency that comes out. We've already + + align:start position:0% +frequency that comes out. We've already + + + align:start position:0% +frequency that comes out. We've already +seen that when we talked about frequency + + align:start position:0% +seen that when we talked about frequency + + + align:start position:0% +seen that when we talked about frequency +response. + + align:start position:0% +response. + + + align:start position:0% +response. +They can only scale the magnitude and + + align:start position:0% +They can only scale the magnitude and + + + align:start position:0% +They can only scale the magnitude and +shift the phase. They can't make new + + align:start position:0% +shift the phase. They can't make new + + + align:start position:0% +shift the phase. They can't make new +frequencies. All they can do is change + + align:start position:0% +frequencies. All they can do is change + + + align:start position:0% +frequencies. All they can do is change +the amplitude and the phase. And that's + + align:start position:0% +the amplitude and the phase. And that's + + + align:start position:0% +the amplitude and the phase. And that's +a very interesting way to think about a + + align:start position:0% +a very interesting way to think about a + + + align:start position:0% +a very interesting way to think about a +system. Think about a lowass filter. + + align:start position:0% +system. Think about a lowass filter. + + + align:start position:0% +system. Think about a lowass filter. +Think about a system whose input is + + align:start position:0% +Think about a system whose input is + + + align:start position:0% +Think about a system whose input is +little VI and whose output is little VO. + + align:start position:0% +little VI and whose output is little VO. + + + align:start position:0% +little VI and whose output is little VO. +You all know how to characterize that a + + align:start position:0% +You all know how to characterize that a + + + align:start position:0% +You all know how to characterize that a +gazillion ways. You would know how to + + align:start position:0% +gazillion ways. You would know how to + + + align:start position:0% +gazillion ways. You would know how to +write a differential equation for that. + + align:start position:0% +write a differential equation for that. + + + align:start position:0% +write a differential equation for that. +Nod your head. Yes. Yes. Yes. You would + + align:start position:0% +Nod your head. Yes. Yes. Yes. You would + + + align:start position:0% +Nod your head. Yes. Yes. Yes. You would +know how to write that as a differential + + align:start position:0% +know how to write that as a differential + + + align:start position:0% +know how to write that as a differential +equation. You'd be able to write a + + align:start position:0% +equation. You'd be able to write a + + + align:start position:0% +equation. You'd be able to write a +system function. you'll be able to do a + + align:start position:0% +system function. you'll be able to do a + + + align:start position:0% +system function. you'll be able to do a +frequency response, a bodie plot, all + + align:start position:0% +frequency response, a bodie plot, all + + + align:start position:0% +frequency response, a bodie plot, all +those sorts of things. + + align:start position:0% +those sorts of things. + + + align:start position:0% +those sorts of things. +That's fine. What I want to do is think + + align:start position:0% +That's fine. What I want to do is think + + + align:start position:0% +That's fine. What I want to do is think +about it instead as a filter. + + align:start position:0% +about it instead as a filter. + + + align:start position:0% +about it instead as a filter. +So + + align:start position:0% +So + + + align:start position:0% +So +imagine the bodie plot, right? Bodie + + align:start position:0% +imagine the bodie plot, right? Bodie + + + align:start position:0% +imagine the bodie plot, right? Bodie +plot's good, right? U so imagine the + + align:start position:0% +plot's good, right? U so imagine the + + + align:start position:0% +plot's good, right? U so imagine the +bodie plot representation for the uh RC + + align:start position:0% +bodie plot representation for the uh RC + + + align:start position:0% +bodie plot representation for the uh RC +lowass filter. You get uh so the RCC low + + align:start position:0% +lowass filter. You get uh so the RCC low + + + align:start position:0% +lowass filter. You get uh so the RCC low +pass filter has a single pole. The pole + + align:start position:0% +pass filter has a single pole. The pole + + + align:start position:0% +pass filter has a single pole. The pole +is at the frequency one over RC minus + + align:start position:0% +is at the frequency one over RC minus + + + align:start position:0% +is at the frequency one over RC minus +one over RC. + + align:start position:0% +one over RC. + + + align:start position:0% +one over RC. +Bodie plot looks like so magnitude has + + align:start position:0% +Bodie plot looks like so magnitude has + + + align:start position:0% +Bodie plot looks like so magnitude has +an asmtote at low frequencies that is a + + align:start position:0% +an asmtote at low frequencies that is a + + + align:start position:0% +an asmtote at low frequencies that is a +constant. At high frequencies it's + + align:start position:0% +constant. At high frequencies it's + + + align:start position:0% +constant. At high frequencies it's +sloping with minus1 or as we would say + + align:start position:0% +sloping with minus1 or as we would say + + + align:start position:0% +sloping with minus1 or as we would say +minus 20 dB per decade + + align:start position:0% +minus 20 dB per decade + + + align:start position:0% +minus 20 dB per decade +and it has some sort of phase response + + align:start position:0% +and it has some sort of phase response + + + align:start position:0% +and it has some sort of phase response +right low frequencies phase is zero. + + align:start position:0% +right low frequencies phase is zero. + + + align:start position:0% +right low frequencies phase is zero. +High frequencies the phase lags by pi + + align:start position:0% +High frequencies the phase lags by pi + + + align:start position:0% +High frequencies the phase lags by pi +over two. + + align:start position:0% +over two. + + + align:start position:0% +over two. +But now let's think about exciting it + + align:start position:0% +But now let's think about exciting it + + + align:start position:0% +But now let's think about exciting it +with a square wave. Square wave is what + + align:start position:0% +with a square wave. Square wave is what + + + align:start position:0% +with a square wave. Square wave is what +we've been thinking about. + + align:start position:0% +we've been thinking about. + + + align:start position:0% +we've been thinking about. +Square wave has a harmonic structure + + align:start position:0% +Square wave has a harmonic structure + + + align:start position:0% +Square wave has a harmonic structure +that falls with K. + + align:start position:0% +that falls with K. + + + align:start position:0% +that falls with K. +So if we represent K= 1 3 5 7 9 on a log + + align:start position:0% +So if we represent K= 1 3 5 7 9 on a log + + + align:start position:0% +So if we represent K= 1 3 5 7 9 on a log +scale + + align:start position:0% +scale + + + align:start position:0% +scale +falling with K is a linear slope. So + + align:start position:0% +falling with K is a linear slope. So + + + align:start position:0% +falling with K is a linear slope. So +this linear decrease in amplitude height + + align:start position:0% +this linear decrease in amplitude height + + + align:start position:0% +this linear decrease in amplitude height +is the reciprocal over here. It's the + + align:start position:0% +is the reciprocal over here. It's the + + + align:start position:0% +is the reciprocal over here. It's the +idea of a log, right? + + align:start position:0% +idea of a log, right? + + + align:start position:0% +idea of a log, right? +So we can represent the signal the + + align:start position:0% +So we can represent the signal the + + + align:start position:0% +So we can represent the signal the +square wave by this amplitude spectrum. + + align:start position:0% +square wave by this amplitude spectrum. + + + align:start position:0% +square wave by this amplitude spectrum. +How big are the components at all the + + align:start position:0% +How big are the components at all the + + + align:start position:0% +How big are the components at all the +different frequencies? Well, there's + + align:start position:0% +different frequencies? Well, there's + + + align:start position:0% +different frequencies? Well, there's +only a discrete number of them. There's + + align:start position:0% +only a discrete number of them. There's + + + align:start position:0% +only a discrete number of them. There's +the what? The k= 1 1, the k= 31, the k= + + align:start position:0% +the what? The k= 1 1, the k= 31, the k= + + + align:start position:0% +the what? The k= 1 1, the k= 31, the k= +5, 1, etc. each one represented by a + + align:start position:0% +5, 1, etc. each one represented by a + + + align:start position:0% +5, 1, etc. each one represented by a +straight line. And they all have phase + + align:start position:0% +straight line. And they all have phase + + + align:start position:0% +straight line. And they all have phase +of minus pi over two because of the j. + + align:start position:0% + + + + align:start position:0% + +Now if you were to choose the base + + align:start position:0% +Now if you were to choose the base + + + align:start position:0% +Now if you were to choose the base +frequency for the square wave so that 2 + + align:start position:0% +frequency for the square wave so that 2 + + + align:start position:0% +frequency for the square wave so that 2 +pi over capital t + + align:start position:0% +pi over capital t + + + align:start position:0% +pi over capital t +omega kn is small compared to the cutff + + align:start position:0% +omega kn is small compared to the cutff + + + align:start position:0% +omega kn is small compared to the cutff +frequency + + align:start position:0% +frequency + + + align:start position:0% +frequency +for the lowass filter. + + align:start position:0% +for the lowass filter. + + + align:start position:0% +for the lowass filter. +What would be the effect on these + + align:start position:0% +What would be the effect on these + + + align:start position:0% +What would be the effect on these +amplitudes + + align:start position:0% +amplitudes + + + align:start position:0% +amplitudes +of this filter? + + align:start position:0% +of this filter? + + + align:start position:0% +of this filter? +Well, the magnitude is one. So if you go + + align:start position:0% +Well, the magnitude is one. So if you go + + + align:start position:0% +Well, the magnitude is one. So if you go +to arbitrarily low frequencies, + + align:start position:0% +to arbitrarily low frequencies, + + + align:start position:0% +to arbitrarily low frequencies, +the magnitude is arbitrarily close to + + align:start position:0% +the magnitude is arbitrarily close to + + + align:start position:0% +the magnitude is arbitrarily close to +one. The phase is arbitrarily close to + + align:start position:0% +one. The phase is arbitrarily close to + + + align:start position:0% +one. The phase is arbitrarily close to +to pi over two. What would happen? + + align:start position:0% + + + + align:start position:0% + +Excuse me. The phase would be + + align:start position:0% +Excuse me. The phase would be + + + align:start position:0% +Excuse me. The phase would be +arbitrarily close to zero. Sorry, I'm + + align:start position:0% +arbitrarily close to zero. Sorry, I'm + + + align:start position:0% +arbitrarily close to zero. Sorry, I'm +supposed to be going to very low + + align:start position:0% +supposed to be going to very low + + + align:start position:0% +supposed to be going to very low +frequencies. If I go to very low + + align:start position:0% +frequencies. If I go to very low + + + align:start position:0% +frequencies. If I go to very low +frequencies, the phase is zero. + + align:start position:0% +frequencies, the phase is zero. + + + align:start position:0% +frequencies, the phase is zero. +If the amplitude is arbitrarily close to + + align:start position:0% +If the amplitude is arbitrarily close to + + + align:start position:0% +If the amplitude is arbitrarily close to +one, the the phase is arbitrarily close + + align:start position:0% +one, the the phase is arbitrarily close + + + align:start position:0% +one, the the phase is arbitrarily close +to zero. And if the input is represented + + align:start position:0% +to zero. And if the input is represented + + + align:start position:0% +to zero. And if the input is represented +by the red lines, what's the output + + align:start position:0% +by the red lines, what's the output + + + align:start position:0% +by the red lines, what's the output +represented by? + + align:start position:0% + + + + align:start position:0% + +Same red lines, right? Each red line is + + align:start position:0% +Same red lines, right? Each red line is + + + align:start position:0% +Same red lines, right? Each red line is +multiplied by one at angle zero. + + align:start position:0% +multiplied by one at angle zero. + + + align:start position:0% +multiplied by one at angle zero. +So the output has the same shape as the + + align:start position:0% +So the output has the same shape as the + + + align:start position:0% +So the output has the same shape as the +input. + + align:start position:0% + + + + align:start position:0% + +If however I shift the period + + align:start position:0% +If however I shift the period + + + align:start position:0% +If however I shift the period +to be shorter so that omega kn is higher + + align:start position:0% +to be shorter so that omega kn is higher + + + align:start position:0% +to be shorter so that omega kn is higher +then I can have some of the higher + + align:start position:0% +then I can have some of the higher + + + align:start position:0% +then I can have some of the higher +frequencies fall into the region of + + align:start position:0% +frequencies fall into the region of + + + align:start position:0% +frequencies fall into the region of +sloping magnitude. + + align:start position:0% +sloping magnitude. + + + align:start position:0% +sloping magnitude. +I can have some of the phases fall into + + align:start position:0% +I can have some of the phases fall into + + + align:start position:0% +I can have some of the phases fall into +the region where the phase is minus pi / + + align:start position:0% +the region where the phase is minus pi / + + + align:start position:0% +the region where the phase is minus pi / +2. + + align:start position:0% +2. + + + align:start position:0% +2. +The way to think about it is the + + align:start position:0% +The way to think about it is the + + + align:start position:0% +The way to think about it is the +fundamental is still going through the + + align:start position:0% +fundamental is still going through the + + + align:start position:0% +fundamental is still going through the +place with unity gain phase of zero. The + + align:start position:0% +place with unity gain phase of zero. The + + + align:start position:0% +place with unity gain phase of zero. The +basic shape is determined by the + + align:start position:0% +basic shape is determined by the + + + align:start position:0% +basic shape is determined by the +fundamental. The basic shape comes + + align:start position:0% +fundamental. The basic shape comes + + + align:start position:0% +fundamental. The basic shape comes +through. + + align:start position:0% +through. + + + align:start position:0% +through. +But now the high frequencies are being + + align:start position:0% +But now the high frequencies are being + + + align:start position:0% +But now the high frequencies are being +altered and their phase relationship is + + align:start position:0% +altered and their phase relationship is + + + align:start position:0% +altered and their phase relationship is +being altered and that's why the shape + + align:start position:0% +being altered and that's why the shape + + + align:start position:0% +being altered and that's why the shape +is different. + + align:start position:0% +is different. + + + align:start position:0% +is different. +If you go to still higher frequencies, + + align:start position:0% +If you go to still higher frequencies, + + + align:start position:0% +If you go to still higher frequencies, +more of the components are filtered. + + align:start position:0% +more of the components are filtered. + + + align:start position:0% +more of the components are filtered. +Each component gets sent through the + + align:start position:0% +Each component gets sent through the + + + align:start position:0% +Each component gets sent through the +frequency response and its amplitude and + + align:start position:0% +frequency response and its amplitude and + + + align:start position:0% +frequency response and its amplitude and +phase are modified appropriately. And if + + align:start position:0% +phase are modified appropriately. And if + + + align:start position:0% +phase are modified appropriately. And if +you go to extremely high frequencies, + + align:start position:0% +you go to extremely high frequencies, + + + align:start position:0% +you go to extremely high frequencies, +then all of the magnitudes + + align:start position:0% +then all of the magnitudes + + + align:start position:0% +then all of the magnitudes +are multiplied by the sloping down line. + + align:start position:0% +are multiplied by the sloping down line. + + + align:start position:0% +are multiplied by the sloping down line. +We turn K convergence, we turn the + + align:start position:0% +We turn K convergence, we turn the + + + align:start position:0% +We turn K convergence, we turn the +reciprocal in K into a reciprocal on K + + align:start position:0% +reciprocal in K into a reciprocal on K + + + align:start position:0% +reciprocal in K into a reciprocal on K +squ. Where have we seen that before? + + align:start position:0% +squ. Where have we seen that before? + + + align:start position:0% +squ. Where have we seen that before? +That was the decomposition for the + + align:start position:0% +That was the decomposition for the + + + align:start position:0% +That was the decomposition for the +triangle wave. So the answer comes out + + align:start position:0% +triangle wave. So the answer comes out + + + align:start position:0% +triangle wave. So the answer comes out +looking like a triangle wave. + + align:start position:0% +looking like a triangle wave. + + + align:start position:0% +looking like a triangle wave. +The point being that in addition to + + align:start position:0% +The point being that in addition to + + + align:start position:0% +The point being that in addition to +thinking about how the system works in + + align:start position:0% +thinking about how the system works in + + + align:start position:0% +thinking about how the system works in +terms of feeding frequencies through it, + + align:start position:0% +terms of feeding frequencies through it, + + + align:start position:0% +terms of feeding frequencies through it, +now we think about how signals work by + + align:start position:0% +now we think about how signals work by + + + align:start position:0% +now we think about how signals work by +breaking them up into frequency parts + + align:start position:0% +breaking them up into frequency parts + + + align:start position:0% +breaking them up into frequency parts +and the whole system then is reduced to + + align:start position:0% +and the whole system then is reduced to + + + align:start position:0% +and the whole system then is reduced to +how does the system modify that + + align:start position:0% +how does the system modify that + + + align:start position:0% +how does the system modify that +component. So that gives rise to the + + align:start position:0% +component. So that gives rise to the + + + align:start position:0% +component. So that gives rise to the +idea of thinking about the fil the + + align:start position:0% +idea of thinking about the fil the + + + align:start position:0% +idea of thinking about the fil the +system as a filter. Systems LTI systems + + align:start position:0% +system as a filter. Systems LTI systems + + + align:start position:0% +system as a filter. Systems LTI systems +do not generate new frequencies. All + + align:start position:0% +do not generate new frequencies. All + + + align:start position:0% +do not generate new frequencies. All +they do is modify the amplitude and + + align:start position:0% +they do is modify the amplitude and + + + align:start position:0% +they do is modify the amplitude and +phase of existing frequencies. If you + + align:start position:0% +phase of existing frequencies. If you + + + align:start position:0% +phase of existing frequencies. If you +enumerate all the existing frequencies, + + align:start position:0% +enumerate all the existing frequencies, + + + align:start position:0% +enumerate all the existing frequencies, +you can just go through them one by one + + align:start position:0% +you can just go through them one by one + + + align:start position:0% +you can just go through them one by one +and figure out how they come out. And + + align:start position:0% +and figure out how they come out. And + + + align:start position:0% +and figure out how they come out. And +that's an equivalent way of thinking + + align:start position:0% +that's an equivalent way of thinking + + + align:start position:0% +that's an equivalent way of thinking +about an LTI system. And that's the kind + + align:start position:0% +about an LTI system. And that's the kind + + + align:start position:0% +about an LTI system. And that's the kind +of a focus that we'll use in the + + align:start position:0% +of a focus that we'll use in the + + + align:start position:0% +of a focus that we'll use in the +remaining part of the course. + + align:start position:0% +remaining part of the course. + + + align:start position:0% +remaining part of the course. +Okay. Thanks. \ No newline at end of file diff --git a/uiG6KY0Cqd8.txt b/uiG6KY0Cqd8.txt new file mode 100644 index 0000000000000000000000000000000000000000..84e65aa826559e9f4869f4f08cfe06a2dadaf830 --- /dev/null +++ b/uiG6KY0Cqd8.txt @@ -0,0 +1,18323 @@ +align:start position:0% + +uh let's start + + align:start position:0% +uh let's start + + + align:start position:0% +uh let's start +this should be + + align:start position:0% +this should be + + + align:start position:0% +this should be +a fun diversion from + + align:start position:0% +a fun diversion from + + + align:start position:0% +a fun diversion from +other things we're doing + + align:start position:0% +other things we're doing + + + align:start position:0% +other things we're doing +we'll + + align:start position:0% +we'll + + + align:start position:0% +we'll +develop methods that are useful in + + align:start position:0% +develop methods that are useful in + + + align:start position:0% +develop methods that are useful in +photogrammetry and + + align:start position:0% +photogrammetry and + + + align:start position:0% +photogrammetry and +robotics + + align:start position:0% +robotics + + + align:start position:0% +robotics +in particular dealing with + + align:start position:0% +in particular dealing with + + + align:start position:0% + +rotation which + + align:start position:0% + + + + align:start position:0% + +has some strange properties + + align:start position:0% +has some strange properties + + + align:start position:0% +has some strange properties +so + + align:start position:0% +so + + + align:start position:0% +so +for example + + align:start position:0% +for example + + + align:start position:0% +for example +in the case of translation things are + + align:start position:0% +in the case of translation things are + + + align:start position:0% +in the case of translation things are +commutative if i go + + align:start position:0% +commutative if i go + + + align:start position:0% +commutative if i go +5 meters in x and 10 meters in y i end + + align:start position:0% +5 meters in x and 10 meters in y i end + + + align:start position:0% +5 meters in x and 10 meters in y i end +up in the same place as if i go + + align:start position:0% +up in the same place as if i go + + + align:start position:0% +up in the same place as if i go +10 meters in y and 5 meters in x + + align:start position:0% +10 meters in y and 5 meters in x + + + align:start position:0% +10 meters in y and 5 meters in x +this is not the case with rotation and + + align:start position:0% +this is not the case with rotation and + + + align:start position:0% +this is not the case with rotation and +to illustrate i suppose that + + align:start position:0% +to illustrate i suppose that + + + align:start position:0% +to illustrate i suppose that +this is the x-axis and this is the + + align:start position:0% +this is the x-axis and this is the + + + align:start position:0% +this is the x-axis and this is the +y-axis so i'm going to take + + align:start position:0% +y-axis so i'm going to take + + + align:start position:0% +y-axis so i'm going to take +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +this eraser and rotate it uh 90 degrees + + align:start position:0% +this eraser and rotate it uh 90 degrees + + + align:start position:0% +this eraser and rotate it uh 90 degrees +about the x-axis like that + + align:start position:0% +about the x-axis like that + + + align:start position:0% +about the x-axis like that +and then 90 degrees about the y-axis and + + align:start position:0% +and then 90 degrees about the y-axis and + + + align:start position:0% +and then 90 degrees about the y-axis and +i end up there and i take the + + align:start position:0% +i end up there and i take the + + + align:start position:0% +i end up there and i take the +equivalent eraser and i rotate it uh 90 + + align:start position:0% +equivalent eraser and i rotate it uh 90 + + + align:start position:0% +equivalent eraser and i rotate it uh 90 +degrees about the y-axis + + align:start position:0% +degrees about the y-axis + + + align:start position:0% +degrees about the y-axis +and then 90 degrees about the x-axis and + + align:start position:0% +and then 90 degrees about the x-axis and + + + align:start position:0% +and then 90 degrees about the x-axis and +i'm there so + + align:start position:0% +i'm there so + + + align:start position:0% +i'm there so +fortunately that worked so they're not + + align:start position:0% +fortunately that worked so they're not + + + align:start position:0% +fortunately that worked so they're not +the same + + align:start position:0% +the same + + + align:start position:0% +the same +and so it's not commutative so it's a + + align:start position:0% +and so it's not commutative so it's a + + + align:start position:0% +and so it's not commutative so it's a +little bit more difficult to deal with + + align:start position:0% +little bit more difficult to deal with + + + align:start position:0% +little bit more difficult to deal with +particularly when it comes to + + align:start position:0% +particularly when it comes to + + + align:start position:0% +particularly when it comes to +least squares problems and + + align:start position:0% +least squares problems and + + + align:start position:0% +least squares problems and +fitting of + + align:start position:0% +fitting of + + + align:start position:0% +fitting of +data to observations + + align:start position:0% +data to observations + + + align:start position:0% +data to observations +so + + align:start position:0% +so + + + align:start position:0% +so +here's an outline of what we're going to + + align:start position:0% +here's an outline of what we're going to + + + align:start position:0% +here's an outline of what we're going to +be talking about + + align:start position:0% +be talking about + + + align:start position:0% +be talking about +properties of rotation + + align:start position:0% +properties of rotation + + + align:start position:0% +properties of rotation +different representation for rotations + + align:start position:0% +different representation for rotations + + + align:start position:0% +different representation for rotations +and in particular the one we're going to + + align:start position:0% +and in particular the one we're going to + + + align:start position:0% +and in particular the one we're going to +pick which is + + align:start position:0% +pick which is + + + align:start position:0% +pick which is +hamilton hamilton's quaternions + + align:start position:0% +hamilton hamilton's quaternions + + + align:start position:0% +hamilton hamilton's quaternions +and um + + align:start position:0% +and um + + + align:start position:0% +and um +they're more general but if we restrict + + align:start position:0% +they're more general but if we restrict + + + align:start position:0% +they're more general but if we restrict +attention to unit quaternions they map + + align:start position:0% +attention to unit quaternions they map + + + align:start position:0% +attention to unit quaternions they map +directly onto rotations in three space + + align:start position:0% +directly onto rotations in three space + + + align:start position:0% +directly onto rotations in three space +they allow us to talk about a space of + + align:start position:0% +they allow us to talk about a space of + + + align:start position:0% +they allow us to talk about a space of +rotation so for translation obviously + + align:start position:0% +rotation so for translation obviously + + + align:start position:0% +rotation so for translation obviously +you know three space is our space of + + align:start position:0% +you know three space is our space of + + + align:start position:0% +you know three space is our space of +translations + + align:start position:0% +translations + + + align:start position:0% +translations +and if we do some optimization + + align:start position:0% +and if we do some optimization + + + align:start position:0% +and if we do some optimization +that's the space we're searching in + + align:start position:0% +that's the space we're searching in + + + align:start position:0% +that's the space we're searching in +that's the space we tessellate that's + + align:start position:0% +that's the space we tessellate that's + + + align:start position:0% +that's the space we tessellate that's +the space where um + + align:start position:0% +the space where um + + + align:start position:0% +the space where um +we get our answers whereas uh it's not + + align:start position:0% +we get our answers whereas uh it's not + + + align:start position:0% +we get our answers whereas uh it's not +so obvious with rotation you know what + + align:start position:0% +so obvious with rotation you know what + + + align:start position:0% +so obvious with rotation you know what +say you want to take an average of force + + align:start position:0% +say you want to take an average of force + + + align:start position:0% +say you want to take an average of force +on a seat belt over all possible + + align:start position:0% +on a seat belt over all possible + + + align:start position:0% +on a seat belt over all possible +orientations of a car + + align:start position:0% +orientations of a car + + + align:start position:0% +orientations of a car +that's something that you know if it was + + align:start position:0% +that's something that you know if it was + + + align:start position:0% +that's something that you know if it was +translation it'd be trivial you just + + align:start position:0% +translation it'd be trivial you just + + + align:start position:0% +translation it'd be trivial you just +integrate over some volume of space + + align:start position:0% +integrate over some volume of space + + + align:start position:0% +integrate over some volume of space +divide by its volume and you're done + + align:start position:0% +divide by its volume and you're done + + + align:start position:0% +divide by its volume and you're done +so that that's something we'll be able + + align:start position:0% +so that that's something we'll be able + + + align:start position:0% +so that that's something we'll be able +to do + + align:start position:0% +to do + + + align:start position:0% +to do +applications are for us mostly in + + align:start position:0% +applications are for us mostly in + + + align:start position:0% +applications are for us mostly in +photogrammetry although they're + + align:start position:0% +photogrammetry although they're + + + align:start position:0% +photogrammetry although they're +very important in robotics and graphics + + align:start position:0% +very important in robotics and graphics + + + align:start position:0% +very important in robotics and graphics +and um control of spacecraft so we'll + + align:start position:0% +and um control of spacecraft so we'll + + + align:start position:0% +and um control of spacecraft so we'll +talk about some of that + + align:start position:0% +talk about some of that + + + align:start position:0% +talk about some of that +and in particular uh using this we're + + align:start position:0% +and in particular uh using this we're + + + align:start position:0% +and in particular uh using this we're +going to develop a closed form solution + + align:start position:0% +going to develop a closed form solution + + + align:start position:0% +going to develop a closed form solution +to the problem that we + + align:start position:0% +to the problem that we + + + align:start position:0% +to the problem that we +started talking about last time which is + + align:start position:0% +started talking about last time which is + + + align:start position:0% +started talking about last time which is +you know either measurements in two + + align:start position:0% +you know either measurements in two + + + align:start position:0% +you know either measurements in two +different coordinate system of the same + + align:start position:0% +different coordinate system of the same + + + align:start position:0% +different coordinate system of the same +object + + align:start position:0% +object + + + align:start position:0% +object +or measurements in one coordinate system + + align:start position:0% +or measurements in one coordinate system + + + align:start position:0% +or measurements in one coordinate system +of two objects or one object that moved + + align:start position:0% +of two objects or one object that moved + + + align:start position:0% +of two objects or one object that moved +so + + align:start position:0% +so + + + align:start position:0% +so +and just for fun at the end we'll + + align:start position:0% +and just for fun at the end we'll + + + align:start position:0% +and just for fun at the end we'll +briefly talk about + + align:start position:0% +briefly talk about + + + align:start position:0% +briefly talk about +division algebras + + align:start position:0% +division algebras + + + align:start position:0% +division algebras +and space time + + align:start position:0% + + + + align:start position:0% + +and so here are some of the things i + + align:start position:0% +and so here are some of the things i + + + align:start position:0% +and so here are some of the things i +mentioned where we need to + + align:start position:0% +mentioned where we need to + + + align:start position:0% +mentioned where we need to +have a good representation for rotation + + align:start position:0% +have a good representation for rotation + + + align:start position:0% +have a good representation for rotation +obviously in machine vision for + + align:start position:0% +obviously in machine vision for + + + align:start position:0% +obviously in machine vision for +recognition and for determining the + + align:start position:0% +recognition and for determining the + + + align:start position:0% +recognition and for determining the +orientation of an object in space for + + align:start position:0% +orientation of an object in space for + + + align:start position:0% +orientation of an object in space for +the robot arm to + + align:start position:0% +the robot arm to + + + align:start position:0% +the robot arm to +and so on so + + align:start position:0% +and so on so + + + align:start position:0% +and so on so +you know down to protein folding + + align:start position:0% +you know down to protein folding + + + align:start position:0% +you know down to protein folding +cryo micros electron microscopy + + align:start position:0% +cryo micros electron microscopy + + + align:start position:0% +cryo micros electron microscopy +we all need a good representation for + + align:start position:0% +we all need a good representation for + + + align:start position:0% +we all need a good representation for +rotation there + + align:start position:0% +rotation there + + + align:start position:0% +rotation there +and + + align:start position:0% +and + + + align:start position:0% +and +in particular with + + align:start position:0% +in particular with + + + align:start position:0% +in particular with +robotic situations we're dealing with + + align:start position:0% +robotic situations we're dealing with + + + align:start position:0% +robotic situations we're dealing with +motions in space + + align:start position:0% +motions in space + + + align:start position:0% +motions in space +euclidean motions which + + align:start position:0% +euclidean motions which + + + align:start position:0% +euclidean motions which +can be decomposed into translations and + + align:start position:0% +can be decomposed into translations and + + + align:start position:0% +can be decomposed into translations and +rotations + + align:start position:0% +rotations + + + align:start position:0% +rotations +and the euclidean motions have the + + align:start position:0% +and the euclidean motions have the + + + align:start position:0% +and the euclidean motions have the +property that they preserve distances + + align:start position:0% +property that they preserve distances + + + align:start position:0% +property that they preserve distances +between points they preserve angles + + align:start position:0% +between points they preserve angles + + + align:start position:0% +between points they preserve angles +between lines and they preserve + + align:start position:0% +between lines and they preserve + + + align:start position:0% +between lines and they preserve +handedness which sometimes we forget but + + align:start position:0% +handedness which sometimes we forget but + + + align:start position:0% +handedness which sometimes we forget but +if we don't put that in then we're going + + align:start position:0% +if we don't put that in then we're going + + + align:start position:0% +if we don't put that in then we're going +to get + + align:start position:0% +to get + + + align:start position:0% +to get +reflections + + align:start position:0% +reflections + + + align:start position:0% +reflections +as you know most of the biologically + + align:start position:0% +as you know most of the biologically + + + align:start position:0% +as you know most of the biologically +important uh chemicals exist in in one + + align:start position:0% +important uh chemicals exist in in one + + + align:start position:0% +important uh chemicals exist in in one +particular form the mirror image form + + align:start position:0% +particular form the mirror image form + + + align:start position:0% +particular form the mirror image form +doesn't work and so it's you know kind + + align:start position:0% +doesn't work and so it's you know kind + + + align:start position:0% +doesn't work and so it's you know kind +of important to preserve-handedness + + align:start position:0% +of important to preserve-handedness + + + align:start position:0% +of important to preserve-handedness +uh put together those mean that we + + align:start position:0% +uh put together those mean that we + + + align:start position:0% +uh put together those mean that we +preserve dot products and we preserve uh + + align:start position:0% +preserve dot products and we preserve uh + + + align:start position:0% +preserve dot products and we preserve uh +triple products and we're leaving out + + align:start position:0% +triple products and we're leaving out + + + align:start position:0% +triple products and we're leaving out +by doing this transformations of free + + align:start position:0% +by doing this transformations of free + + + align:start position:0% +by doing this transformations of free +space that you know would otherwise be + + align:start position:0% +space that you know would otherwise be + + + align:start position:0% +space that you know would otherwise be +perfectly reasonable + + align:start position:0% +perfectly reasonable + + + align:start position:0% +perfectly reasonable +such as reflections and skewing and + + align:start position:0% +such as reflections and skewing and + + + align:start position:0% +such as reflections and skewing and +scaling we'll talk a little bit about + + align:start position:0% +scaling we'll talk a little bit about + + + align:start position:0% +scaling we'll talk a little bit about +scaling but + + align:start position:0% +scaling but + + + align:start position:0% +scaling but +mostly for the moment we leave it out + + align:start position:0% +mostly for the moment we leave it out + + + align:start position:0% +mostly for the moment we leave it out +so + + align:start position:0% +so + + + align:start position:0% +so +rotations first euler's theorem + + align:start position:0% +rotations first euler's theorem + + + align:start position:0% +rotations first euler's theorem +any rotation of a rigid object has the + + align:start position:0% +any rotation of a rigid object has the + + + align:start position:0% +any rotation of a rigid object has the +property that there is a line that is + + align:start position:0% +property that there is a line that is + + + align:start position:0% +property that there is a line that is +not changed that's the axis + + align:start position:0% +not changed that's the axis + + + align:start position:0% +not changed that's the axis +then + + align:start position:0% +then + + + align:start position:0% +then +there's the parallel axis theorem which + + align:start position:0% +there's the parallel axis theorem which + + + align:start position:0% +there's the parallel axis theorem which +says that + + align:start position:0% +says that + + + align:start position:0% +says that +any rotation + + align:start position:0% +any rotation + + + align:start position:0% +any rotation +about any axis is equivalent to a + + align:start position:0% +about any axis is equivalent to a + + + align:start position:0% +about any axis is equivalent to a +rotation about an axis through the + + align:start position:0% +rotation about an axis through the + + + align:start position:0% +rotation about an axis through the +origin + + align:start position:0% +origin + + + align:start position:0% +origin +plus a translation + + align:start position:0% +plus a translation + + + align:start position:0% +plus a translation +so + + align:start position:0% +so + + + align:start position:0% +so +for us it's going to be very convenient + + align:start position:0% +for us it's going to be very convenient + + + align:start position:0% +for us it's going to be very convenient +to separate translation and rotation + + align:start position:0% +to separate translation and rotation + + + align:start position:0% +to separate translation and rotation +this way that when we talk about + + align:start position:0% +this way that when we talk about + + + align:start position:0% +this way that when we talk about +rotation that we're going to recover + + align:start position:0% +rotation that we're going to recover + + + align:start position:0% +rotation that we're going to recover +we're just going to talk about rotation + + align:start position:0% +we're just going to talk about rotation + + + align:start position:0% +we're just going to talk about rotation +about an axis through the origin because + + align:start position:0% +about an axis through the origin because + + + align:start position:0% +about an axis through the origin because +we deal with the translation separately + + align:start position:0% +we deal with the translation separately + + + align:start position:0% +we deal with the translation separately +and because of the parallel axis theorem + + align:start position:0% +and because of the parallel axis theorem + + + align:start position:0% +and because of the parallel axis theorem +we can do that then if we figure out how + + align:start position:0% +we can do that then if we figure out how + + + align:start position:0% +we can do that then if we figure out how +a sphere rotates + + align:start position:0% +a sphere rotates + + + align:start position:0% +a sphere rotates +we basically figured out how everything + + align:start position:0% +we basically figured out how everything + + + align:start position:0% +we basically figured out how everything +rotates because we can and that sort of + + align:start position:0% +rotates because we can and that sort of + + + align:start position:0% +rotates because we can and that sort of +simplifies thing we can just think of + + align:start position:0% +simplifies thing we can just think of + + + align:start position:0% +simplifies thing we can just think of +sphere rotating in space and all the + + align:start position:0% +sphere rotating in space and all the + + + align:start position:0% +sphere rotating in space and all the +possible ways that can happen and that + + align:start position:0% +possible ways that can happen and that + + + align:start position:0% +possible ways that can happen and that +then corresponds to + + align:start position:0% +then corresponds to + + + align:start position:0% +then corresponds to +rotation of space + + align:start position:0% +rotation of space + + + align:start position:0% +rotation of space +when we talk about attitude we basically + + align:start position:0% +when we talk about attitude we basically + + + align:start position:0% +when we talk about attitude we basically +mean orientation we mean orientation + + align:start position:0% +mean orientation we mean orientation + + + align:start position:0% +mean orientation we mean orientation +relative to some standard so for example + + align:start position:0% +relative to some standard so for example + + + align:start position:0% +relative to some standard so for example +we might have models + + align:start position:0% +we might have models + + + align:start position:0% +we might have models +as we had when we're talking about the + + align:start position:0% +as we had when we're talking about the + + + align:start position:0% +as we had when we're talking about the +patents except now in 3d + + align:start position:0% +patents except now in 3d + + + align:start position:0% +patents except now in 3d +and they'll be in some preferred + + align:start position:0% +and they'll be in some preferred + + + align:start position:0% +and they'll be in some preferred +coordinate system and when we talk about + + align:start position:0% +coordinate system and when we talk about + + + align:start position:0% +coordinate system and when we talk about +locating that object we're talking about + + align:start position:0% +locating that object we're talking about + + + align:start position:0% +locating that object we're talking about +finding its position in space and + + align:start position:0% +finding its position in space and + + + align:start position:0% +finding its position in space and +finding its rotation relative to that + + align:start position:0% +finding its rotation relative to that + + + align:start position:0% +finding its rotation relative to that +reference rotation + + align:start position:0% +reference rotation + + + align:start position:0% +reference rotation +so by the way + + align:start position:0% +so by the way + + + align:start position:0% +so by the way +this is going to be on stellar + + align:start position:0% +this is going to be on stellar + + + align:start position:0% +this is going to be on stellar +this whole presentation + + align:start position:0% +this whole presentation + + + align:start position:0% +this whole presentation +then there's a + + align:start position:0% +then there's a + + + align:start position:0% +then there's a +four-page blurb that summarizes + + align:start position:0% +four-page blurb that summarizes + + + align:start position:0% +four-page blurb that summarizes +everything you want to know about + + align:start position:0% +everything you want to know about + + + align:start position:0% +everything you want to know about +quaternions + + align:start position:0% +quaternions + + + align:start position:0% +quaternions +or maybe not + + align:start position:0% +or maybe not + + + align:start position:0% +or maybe not +maybe everything you need for this + + align:start position:0% +maybe everything you need for this + + + align:start position:0% +maybe everything you need for this +course + + align:start position:0% +course + + + align:start position:0% +course +degrees of freedom so we talked about + + align:start position:0% +degrees of freedom so we talked about + + + align:start position:0% +degrees of freedom so we talked about +this last time that there happened to be + + align:start position:0% +this last time that there happened to be + + + align:start position:0% +this last time that there happened to be +three degrees of freedom to rotation and + + align:start position:0% +three degrees of freedom to rotation and + + + align:start position:0% +three degrees of freedom to rotation and +that can be slightly confusing + + align:start position:0% +that can be slightly confusing + + + align:start position:0% +that can be slightly confusing +what's interesting is that rotational + + align:start position:0% +what's interesting is that rotational + + + align:start position:0% +what's interesting is that rotational +velocity is much easier + + align:start position:0% +velocity is much easier + + + align:start position:0% +velocity is much easier +angular velocity all we need is a vector + + align:start position:0% +angular velocity all we need is a vector + + + align:start position:0% +angular velocity all we need is a vector +that gives us the axis + + align:start position:0% +that gives us the axis + + + align:start position:0% +that gives us the axis +and a rate + + align:start position:0% +and a rate + + + align:start position:0% +and a rate +so many radians per second and if we + + align:start position:0% +so many radians per second and if we + + + align:start position:0% +so many radians per second and if we +take the axis and multiply it by the + + align:start position:0% +take the axis and multiply it by the + + + align:start position:0% +take the axis and multiply it by the +rate we have a three vector + + align:start position:0% +rate we have a three vector + + + align:start position:0% +rate we have a three vector +and those three vectors add just like + + align:start position:0% +and those three vectors add just like + + + align:start position:0% +and those three vectors add just like +translations so if you're spinning + + align:start position:0% +translations so if you're spinning + + + align:start position:0% +translations so if you're spinning +around the x-axis at you know one radian + + align:start position:0% +around the x-axis at you know one radian + + + align:start position:0% +around the x-axis at you know one radian +per second you're spinning about the + + align:start position:0% +per second you're spinning about the + + + align:start position:0% +per second you're spinning about the +y-axis at one radian per second then + + align:start position:0% +y-axis at one radian per second then + + + align:start position:0% +y-axis at one radian per second then +you're spinning about the one one zero + + align:start position:0% +you're spinning about the one one zero + + + align:start position:0% +you're spinning about the one one zero +axis you know so it's very easy to just + + align:start position:0% +axis you know so it's very easy to just + + + align:start position:0% +axis you know so it's very easy to just +add these up + + align:start position:0% +add these up + + + align:start position:0% +add these up +and + + align:start position:0% +and + + + align:start position:0% +and +of course that can change so now you've + + align:start position:0% +of course that can change so now you've + + + align:start position:0% +of course that can change so now you've +moved a little bit and the next time + + align:start position:0% +moved a little bit and the next time + + + align:start position:0% +moved a little bit and the next time +instance the axis will be different so + + align:start position:0% +instance the axis will be different so + + + align:start position:0% +instance the axis will be different so +but instantaneously rotational velocity + + align:start position:0% +but instantaneously rotational velocity + + + align:start position:0% +but instantaneously rotational velocity +is very easy + + align:start position:0% +is very easy + + + align:start position:0% +is very easy +and this + + align:start position:0% +and this + + + align:start position:0% +and this +for those of you who know about these + + align:start position:0% +for those of you who know about these + + + align:start position:0% +for those of you who know about these +things + + align:start position:0% +things + + + align:start position:0% +things +corresponds to you know the the lee + + align:start position:0% +corresponds to you know the the lee + + + align:start position:0% +corresponds to you know the the lee +algebra versus the lead group + + align:start position:0% +algebra versus the lead group + + + align:start position:0% +algebra versus the lead group +the + + align:start position:0% +the + + + align:start position:0% +the +rotational velocities are the algebra it + + align:start position:0% +rotational velocities are the algebra it + + + align:start position:0% +rotational velocities are the algebra it +has all the nice properties of an + + align:start position:0% +has all the nice properties of an + + + align:start position:0% +has all the nice properties of an +algebra + + align:start position:0% +algebra + + + align:start position:0% +algebra +the rotations which are sort of the + + align:start position:0% +the rotations which are sort of the + + + align:start position:0% +the rotations which are sort of the +integral of that don't they don't have + + align:start position:0% +integral of that don't they don't have + + + align:start position:0% +integral of that don't they don't have +quite those nice properties + + align:start position:0% +quite those nice properties + + + align:start position:0% +quite those nice properties +poisson's formula tells you what the + + align:start position:0% +poisson's formula tells you what the + + + align:start position:0% +poisson's formula tells you what the +velocity is of some point uh when + + align:start position:0% +velocity is of some point uh when + + + align:start position:0% +velocity is of some point uh when +there's a known rotational veloci um + + align:start position:0% +there's a known rotational veloci um + + + align:start position:0% +there's a known rotational veloci um +right rotational velocity so omega + + align:start position:0% +right rotational velocity so omega + + + align:start position:0% +right rotational velocity so omega +is that vector + + align:start position:0% +is that vector + + + align:start position:0% +is that vector +the + + align:start position:0% +the + + + align:start position:0% +the +axis of which is the axis of the + + align:start position:0% +axis of which is the axis of the + + + align:start position:0% +axis of which is the axis of the +direction of which is the axis of + + align:start position:0% +direction of which is the axis of + + + align:start position:0% +direction of which is the axis of +rotation and the magnitude of it is the + + align:start position:0% +rotation and the magnitude of it is the + + + align:start position:0% +rotation and the magnitude of it is the +rate of rotation and then if we have + + align:start position:0% +rate of rotation and then if we have + + + align:start position:0% +rate of rotation and then if we have +some point r we just take that cross + + align:start position:0% +some point r we just take that cross + + + align:start position:0% +some point r we just take that cross +product to figure out what the velocity + + align:start position:0% +product to figure out what the velocity + + + align:start position:0% +product to figure out what the velocity +is and obviously + + align:start position:0% +is and obviously + + + align:start position:0% +is and obviously +it's going to be perpendicular to r and + + align:start position:0% +it's going to be perpendicular to r and + + + align:start position:0% +it's going to be perpendicular to r and +it's going to be perpendicular to omega + + align:start position:0% +it's going to be perpendicular to omega + + + align:start position:0% +it's going to be perpendicular to omega +and you can you know get its direction + + align:start position:0% +and you can you know get its direction + + + align:start position:0% +and you can you know get its direction +by using the right hand rule + + align:start position:0% +by using the right hand rule + + + align:start position:0% +by using the right hand rule +so rotational velocity is simpler they + + align:start position:0% +so rotational velocity is simpler they + + + align:start position:0% +so rotational velocity is simpler they +add + + align:start position:0% +add + + + align:start position:0% +add +and we just saw finite finite rotations + + align:start position:0% +and we just saw finite finite rotations + + + align:start position:0% +and we just saw finite finite rotations +don't commute and we talked last time + + align:start position:0% +don't commute and we talked last time + + + align:start position:0% +don't commute and we talked last time +about how they're + + align:start position:0% +about how they're + + + align:start position:0% +about how they're +n times n minus one over two degrees of + + align:start position:0% +n times n minus one over two degrees of + + + align:start position:0% +n times n minus one over two degrees of +freedom + + align:start position:0% +freedom + + + align:start position:0% +freedom +and for n equals three that happens to + + align:start position:0% +and for n equals three that happens to + + + align:start position:0% +and for n equals three that happens to +give you three + + align:start position:0% +give you three + + + align:start position:0% +give you three +so often we talk about rotation about + + align:start position:0% +so often we talk about rotation about + + + align:start position:0% +so often we talk about rotation about +axes like i just did rotation about the + + align:start position:0% +axes like i just did rotation about the + + + align:start position:0% +axes like i just did rotation about the +x-axis rotation about the y-axis + + align:start position:0% +x-axis rotation about the y-axis + + + align:start position:0% +x-axis rotation about the y-axis +and + + align:start position:0% +and + + + align:start position:0% +and +if you follow that + + align:start position:0% +if you follow that + + + align:start position:0% +if you follow that +view then you might think that in + + align:start position:0% +view then you might think that in + + + align:start position:0% +view then you might think that in +n-dimensions rotation is n-dimensional + + align:start position:0% +n-dimensions rotation is n-dimensional + + + align:start position:0% +n-dimensions rotation is n-dimensional +and therefore it is better to think + + align:start position:0% +and therefore it is better to think + + + align:start position:0% +and therefore it is better to think +about rotation as rotation preserving + + align:start position:0% +about rotation as rotation preserving + + + align:start position:0% +about rotation as rotation preserving +certain planes + + align:start position:0% +certain planes + + + align:start position:0% +certain planes +so for example we can preserve the x y + + align:start position:0% +so for example we can preserve the x y + + + align:start position:0% +so for example we can preserve the x y +plane + + align:start position:0% +plane + + + align:start position:0% +plane +uh we can rotate in such a way that the + + align:start position:0% +uh we can rotate in such a way that the + + + align:start position:0% +uh we can rotate in such a way that the +x y plane is not changed the things in + + align:start position:0% +x y plane is not changed the things in + + + align:start position:0% +x y plane is not changed the things in +the x y plane are moved into x y plane + + align:start position:0% +the x y plane are moved into x y plane + + + align:start position:0% +the x y plane are moved into x y plane +somewhere else + + align:start position:0% +somewhere else + + + align:start position:0% +somewhere else +uh y z plane and z x plane also three + + align:start position:0% +uh y z plane and z x plane also three + + + align:start position:0% +uh y z plane and z x plane also three +but that one works because in in 2d + + align:start position:0% +but that one works because in in 2d + + + align:start position:0% +but that one works because in in 2d +we only have the xy plane one degree of + + align:start position:0% +we only have the xy plane one degree of + + + align:start position:0% +we only have the xy plane one degree of +freedom + + align:start position:0% +freedom + + + align:start position:0% +freedom +and in 4d we have + + align:start position:0% +and in 4d we have + + + align:start position:0% +and in 4d we have +six combinations and that's the number + + align:start position:0% +six combinations and that's the number + + + align:start position:0% +six combinations and that's the number +of degrees of freedom of rotation in 4d + + align:start position:0% +of degrees of freedom of rotation in 4d + + + align:start position:0% +of degrees of freedom of rotation in 4d +okay um + + align:start position:0% + + + + align:start position:0% + +so before we go further + + align:start position:0% +so before we go further + + + align:start position:0% +so before we go further +here's a + + align:start position:0% +here's a + + + align:start position:0% +here's a +interesting thing that we will exploit + + align:start position:0% +interesting thing that we will exploit + + + align:start position:0% +interesting thing that we will exploit +and also it's a + + align:start position:0% +and also it's a + + + align:start position:0% +and also it's a +kind of preview of a method we'll use + + align:start position:0% +kind of preview of a method we'll use + + + align:start position:0% +kind of preview of a method we'll use +which is uh + + align:start position:0% +which is uh + + + align:start position:0% +which is uh +you know cross products cross products + + align:start position:0% +you know cross products cross products + + + align:start position:0% +you know cross products cross products +as i mentioned are kind of confusing + + align:start position:0% +as i mentioned are kind of confusing + + + align:start position:0% +as i mentioned are kind of confusing +because you take the product of two + + align:start position:0% +because you take the product of two + + + align:start position:0% +because you take the product of two +vectors and you get another vector + + align:start position:0% +vectors and you get another vector + + + align:start position:0% +vectors and you get another vector +which isn't quite right but it happens + + align:start position:0% +which isn't quite right but it happens + + + align:start position:0% +which isn't quite right but it happens +to have three + + align:start position:0% +to have three + + + align:start position:0% +to have three +degrees of freedom so we represent it as + + align:start position:0% +degrees of freedom so we represent it as + + + align:start position:0% +degrees of freedom so we represent it as +a vector + + align:start position:0% +a vector + + + align:start position:0% +a vector +and um + + align:start position:0% +and um + + + align:start position:0% +and um +again that's a coincidence + + align:start position:0% +again that's a coincidence + + + align:start position:0% +again that's a coincidence +what is it well it's perpendicular to + + align:start position:0% +what is it well it's perpendicular to + + + align:start position:0% +what is it well it's perpendicular to +the two vectors you started with + + align:start position:0% +the two vectors you started with + + + align:start position:0% +the two vectors you started with +and so in + + align:start position:0% +and so in + + + align:start position:0% +and so in +higher dimensional space if you take + + align:start position:0% +higher dimensional space if you take + + + align:start position:0% +higher dimensional space if you take +if you say you know what are the things + + align:start position:0% +if you say you know what are the things + + + align:start position:0% +if you say you know what are the things +that are perpendicular to two vectors + + align:start position:0% +that are perpendicular to two vectors + + + align:start position:0% +that are perpendicular to two vectors +well they're not going to be a vector + + align:start position:0% +well they're not going to be a vector + + + align:start position:0% +well they're not going to be a vector +there's going to be a whole subspace + + align:start position:0% +there's going to be a whole subspace + + + align:start position:0% +there's going to be a whole subspace +so the generalization of a cross product + + align:start position:0% +so the generalization of a cross product + + + align:start position:0% +so the generalization of a cross product +would be something more complicated like + + align:start position:0% +would be something more complicated like + + + align:start position:0% +would be something more complicated like +uh one way to generalize it in an + + align:start position:0% +uh one way to generalize it in an + + + align:start position:0% +uh one way to generalize it in an +n-dimensional space is it's that vector + + align:start position:0% +n-dimensional space is it's that vector + + + align:start position:0% +n-dimensional space is it's that vector +that's perpendicular to n minus one + + align:start position:0% +that's perpendicular to n minus one + + + align:start position:0% +that's perpendicular to n minus one +other vectors well here n minus one + + align:start position:0% +other vectors well here n minus one + + + align:start position:0% +other vectors well here n minus one +happens to be two so + + align:start position:0% +happens to be two so + + + align:start position:0% +happens to be two so +that's where we get our cross product + + align:start position:0% +that's where we get our cross product + + + align:start position:0% +that's where we get our cross product +and it's + + align:start position:0% +and it's + + + align:start position:0% +and it's +actually very convenient + + align:start position:0% +actually very convenient + + + align:start position:0% +actually very convenient +for certain operations + + align:start position:0% +for certain operations + + + align:start position:0% +for certain operations +particularly matrix vector operations to + + align:start position:0% +particularly matrix vector operations to + + + align:start position:0% +particularly matrix vector operations to +represent the cross product in this way + + align:start position:0% +represent the cross product in this way + + + align:start position:0% +represent the cross product in this way +where we + + align:start position:0% +where we + + + align:start position:0% +where we +uh take the skew symmetric matrix + + align:start position:0% +uh take the skew symmetric matrix + + + align:start position:0% +uh take the skew symmetric matrix +and we can represent a cross b by + + align:start position:0% +and we can represent a cross b by + + + align:start position:0% +and we can represent a cross b by +multiplying that + + align:start position:0% +multiplying that + + + align:start position:0% +multiplying that +skew symmetric matrix by b + + align:start position:0% +skew symmetric matrix by b + + + align:start position:0% +skew symmetric matrix by b +and it has the right degrees of freedom + + align:start position:0% +and it has the right degrees of freedom + + + align:start position:0% +and it has the right degrees of freedom +right because a has three degrees of + + align:start position:0% +right because a has three degrees of + + + align:start position:0% +right because a has three degrees of +freedom + + align:start position:0% +freedom + + + align:start position:0% +freedom +a skew-symmetric matrix has zero on the + + align:start position:0% +a skew-symmetric matrix has zero on the + + + align:start position:0% +a skew-symmetric matrix has zero on the +diagonal and + + align:start position:0% +diagonal and + + + align:start position:0% +diagonal and +the off-diagonal symmetric so you again + + align:start position:0% +the off-diagonal symmetric so you again + + + align:start position:0% +the off-diagonal symmetric so you again +have three degrees of freedom so + + align:start position:0% +have three degrees of freedom so + + + align:start position:0% +have three degrees of freedom so +that seems like a reasonable isomorphism + + align:start position:0% +that seems like a reasonable isomorphism + + + align:start position:0% +that seems like a reasonable isomorphism +and + + align:start position:0% +and + + + align:start position:0% +and +then once you've done that you've gotten + + align:start position:0% +then once you've done that you've gotten + + + align:start position:0% +then once you've done that you've gotten +rid of this weird thing the cross + + align:start position:0% +rid of this weird thing the cross + + + align:start position:0% +rid of this weird thing the cross +product and you have something that you + + align:start position:0% +product and you have something that you + + + align:start position:0% +product and you have something that you +can manipulate in combination with other + + align:start position:0% +can manipulate in combination with other + + + align:start position:0% +can manipulate in combination with other +vectors and matrices + + align:start position:0% +vectors and matrices + + + align:start position:0% +vectors and matrices +now of course why did we pick a to + + align:start position:0% +now of course why did we pick a to + + + align:start position:0% +now of course why did we pick a to +expand as the matrix we could equally + + align:start position:0% +expand as the matrix we could equally + + + align:start position:0% +expand as the matrix we could equally +well have picked b + + align:start position:0% +well have picked b + + + align:start position:0% +well have picked b +and have written it this way equally + + align:start position:0% +and have written it this way equally + + + align:start position:0% +and have written it this way equally +valid uh and you'll notice this matrix + + align:start position:0% +valid uh and you'll notice this matrix + + + align:start position:0% +valid uh and you'll notice this matrix +is uh you know + + align:start position:0% +is uh you know + + + align:start position:0% +is uh you know +transpose or negate that version of of + + align:start position:0% +transpose or negate that version of of + + + align:start position:0% +transpose or negate that version of of +that matrix + + align:start position:0% +that matrix + + + align:start position:0% +that matrix +so the matrix for b + + align:start position:0% +so the matrix for b + + + align:start position:0% +so the matrix for b +so it's order dependent and we know that + + align:start position:0% +so it's order dependent and we know that + + + align:start position:0% +so it's order dependent and we know that +because + + align:start position:0% +because + + + align:start position:0% +because +cross products don't don't commute so + + align:start position:0% + + + + align:start position:0% + +okay there are loads of representations + + align:start position:0% +okay there are loads of representations + + + align:start position:0% +okay there are loads of representations +for rotation which tells you that + + align:start position:0% +for rotation which tells you that + + + align:start position:0% +for rotation which tells you that +there's a problem you know with + + align:start position:0% +there's a problem you know with + + + align:start position:0% +there's a problem you know with +translation we just have x y z be done + + align:start position:0% +translation we just have x y z be done + + + align:start position:0% +translation we just have x y z be done +with it + + align:start position:0% +with it + + + align:start position:0% +with it +um so one uh one notation that's very + + align:start position:0% +um so one uh one notation that's very + + + align:start position:0% +um so one uh one notation that's very +useful is um axis and angle so we have + + align:start position:0% +useful is um axis and angle so we have + + + align:start position:0% +useful is um axis and angle so we have +an axis which can be given as a unit + + align:start position:0% +an axis which can be given as a unit + + + align:start position:0% +an axis which can be given as a unit +vector and we have a + + align:start position:0% +vector and we have a + + + align:start position:0% +vector and we have a +number of degrees that we rotate or + + align:start position:0% +number of degrees that we rotate or + + + align:start position:0% +number of degrees that we rotate or +radians that we rotate through so that's + + align:start position:0% +radians that we rotate through so that's + + + align:start position:0% +radians that we rotate through so that's +three degrees of freedom because the + + align:start position:0% +three degrees of freedom because the + + + align:start position:0% +three degrees of freedom because the +unit vector only has two and plus the + + align:start position:0% +unit vector only has two and plus the + + + align:start position:0% +unit vector only has two and plus the +angle gives us 3. + + align:start position:0% +angle gives us 3. + + + align:start position:0% +angle gives us 3. +now + + align:start position:0% +now + + + align:start position:0% +now +sometimes + + align:start position:0% +sometimes + + + align:start position:0% +sometimes +we can derive other notations from that + + align:start position:0% +we can derive other notations from that + + + align:start position:0% +we can derive other notations from that +one of them is the gibbs vector which + + align:start position:0% +one of them is the gibbs vector which + + + align:start position:0% +one of them is the gibbs vector which +tries to combine those two + + align:start position:0% +tries to combine those two + + + align:start position:0% +tries to combine those two +you know into a single thing so this + + align:start position:0% +you know into a single thing so this + + + align:start position:0% +you know into a single thing so this +this is sort of inconvenient in a way + + align:start position:0% +this is sort of inconvenient in a way + + + align:start position:0% +this is sort of inconvenient in a way +because you've got a three vector which + + align:start position:0% +because you've got a three vector which + + + align:start position:0% +because you've got a three vector which +happens to be unit vector and then you + + align:start position:0% +happens to be unit vector and then you + + + align:start position:0% +happens to be unit vector and then you +have this thing + + align:start position:0% +have this thing + + + align:start position:0% +have this thing +so the gibbs vector + + align:start position:0% +so the gibbs vector + + + align:start position:0% +so the gibbs vector +is a vector and and it turns out that + + align:start position:0% +is a vector and and it turns out that + + + align:start position:0% +is a vector and and it turns out that +you don't want to just multiply by theta + + align:start position:0% +you don't want to just multiply by theta + + + align:start position:0% +you don't want to just multiply by theta +that doesn't give you uh nice algebraic + + align:start position:0% +that doesn't give you uh nice algebraic + + + align:start position:0% +that doesn't give you uh nice algebraic +properties uh it's much better and plus + + align:start position:0% +properties uh it's much better and plus + + + align:start position:0% +properties uh it's much better and plus +you know theta wraps around 2 pi so that + + align:start position:0% +you know theta wraps around 2 pi so that + + + align:start position:0% +you know theta wraps around 2 pi so that +doesn't really make much sense anyway + + align:start position:0% +doesn't really make much sense anyway + + + align:start position:0% +doesn't really make much sense anyway +and gibbs found out that you can get + + align:start position:0% +and gibbs found out that you can get + + + align:start position:0% +and gibbs found out that you can get +some useful properties by taking tan + + align:start position:0% +some useful properties by taking tan + + + align:start position:0% +some useful properties by taking tan +theta over two so now you have a vector + + align:start position:0% +theta over two so now you have a vector + + + align:start position:0% +theta over two so now you have a vector +it's no longer a unit vector so it has + + align:start position:0% +it's no longer a unit vector so it has + + + align:start position:0% +it's no longer a unit vector so it has +three components so it has the right + + align:start position:0% +three components so it has the right + + + align:start position:0% +three components so it has the right +number of degrees of freedom + + align:start position:0% +number of degrees of freedom + + + align:start position:0% +number of degrees of freedom +only bad thing is + + align:start position:0% +only bad thing is + + + align:start position:0% +only bad thing is +it blows up at theta equals pi right + + align:start position:0% +it blows up at theta equals pi right + + + align:start position:0% +it blows up at theta equals pi right +because tan of pi over 2 is infinite + + align:start position:0% +because tan of pi over 2 is infinite + + + align:start position:0% +because tan of pi over 2 is infinite +uh and theta over pi so is that a + + align:start position:0% +uh and theta over pi so is that a + + + align:start position:0% +uh and theta over pi so is that a +problem well you know rotating through + + align:start position:0% +problem well you know rotating through + + + align:start position:0% +problem well you know rotating through +180 degrees that's a perfectly + + align:start position:0% +180 degrees that's a perfectly + + + align:start position:0% +180 degrees that's a perfectly +reasonable thing to do so it's not like + + align:start position:0% +reasonable thing to do so it's not like + + + align:start position:0% +reasonable thing to do so it's not like +we want to exclude that because it's not + + align:start position:0% +we want to exclude that because it's not + + + align:start position:0% +we want to exclude that because it's not +a reasonable thing to do so that is a + + align:start position:0% +a reasonable thing to do so that is a + + + align:start position:0% +a reasonable thing to do so that is a +problem and it's very similar to you + + align:start position:0% +problem and it's very similar to you + + + align:start position:0% +problem and it's very similar to you +know y equals mx plus c when when the + + align:start position:0% +know y equals mx plus c when when the + + + align:start position:0% +know y equals mx plus c when when the +line happens to be perpendicular up + + align:start position:0% +line happens to be perpendicular up + + + align:start position:0% +line happens to be perpendicular up +parallel to the y axis + + align:start position:0% +parallel to the y axis + + + align:start position:0% +parallel to the y axis +then we have euler angles + + align:start position:0% +then we have euler angles + + + align:start position:0% +then we have euler angles +and there's a classic uh + + align:start position:0% +and there's a classic uh + + + align:start position:0% +and there's a classic uh +text in mechanical engineering by by + + align:start position:0% +text in mechanical engineering by by + + + align:start position:0% +text in mechanical engineering by by +gold + + align:start position:0% +gold + + + align:start position:0% +gold +uh which explains about euler angles + + align:start position:0% +uh which explains about euler angles + + + align:start position:0% +uh which explains about euler angles +basically you know you rotate about x + + align:start position:0% +basically you know you rotate about x + + + align:start position:0% +basically you know you rotate about x +you rotate about y rotate about z + + align:start position:0% +you rotate about y rotate about z + + + align:start position:0% +you rotate about y rotate about z +if you're in an airplane + + align:start position:0% +if you're in an airplane + + + align:start position:0% +if you're in an airplane +you have roll which is rotation about + + align:start position:0% +you have roll which is rotation about + + + align:start position:0% +you have roll which is rotation about +the axis length long axis of the plane + + align:start position:0% +the axis length long axis of the plane + + + align:start position:0% +the axis length long axis of the plane +then you have pitch which is + + align:start position:0% +then you have pitch which is + + + align:start position:0% +then you have pitch which is +going up or down and then you have your + + align:start position:0% +going up or down and then you have your + + + align:start position:0% +going up or down and then you have your +which is going left and right + + align:start position:0% +which is going left and right + + + align:start position:0% +which is going left and right +so it's + + align:start position:0% +so it's + + + align:start position:0% +so it's +very convenient to think about that but + + align:start position:0% +very convenient to think about that but + + + align:start position:0% +very convenient to think about that but +as you know + + align:start position:0% +as you know + + + align:start position:0% +as you know +the result will depend on the order so + + align:start position:0% +the result will depend on the order so + + + align:start position:0% +the result will depend on the order so +yeah if you have very small angles of + + align:start position:0% +yeah if you have very small angles of + + + align:start position:0% +yeah if you have very small angles of +roll pitch and yaw which is a + + align:start position:0% +roll pitch and yaw which is a + + + align:start position:0% +roll pitch and yaw which is a +comfortable airplane flight + + align:start position:0% +comfortable airplane flight + + + align:start position:0% +comfortable airplane flight +it probably doesn't matter a lot because + + align:start position:0% +it probably doesn't matter a lot because + + + align:start position:0% +it probably doesn't matter a lot because +you get pretty much the same result if + + align:start position:0% +you get pretty much the same result if + + + align:start position:0% +you get pretty much the same result if +you + + align:start position:0% +you + + + align:start position:0% +you +compose them in different orders but if + + align:start position:0% +compose them in different orders but if + + + align:start position:0% +compose them in different orders but if +you have + + align:start position:0% +you have + + + align:start position:0% +you have +large angles like 90 degrees you know + + align:start position:0% +large angles like 90 degrees you know + + + align:start position:0% +large angles like 90 degrees you know +it's definitely not going to work + + align:start position:0% +it's definitely not going to work + + + align:start position:0% +it's definitely not going to work +so that means if you define euler angles + + align:start position:0% +so that means if you define euler angles + + + align:start position:0% +so that means if you define euler angles +you've got to do several things one of + + align:start position:0% +you've got to do several things one of + + + align:start position:0% +you've got to do several things one of +them is you have to define the order of + + align:start position:0% +them is you have to define the order of + + + align:start position:0% +them is you have to define the order of +operations you know does the x-axis come + + align:start position:0% +operations you know does the x-axis come + + + align:start position:0% +operations you know does the x-axis come +first and so on + + align:start position:0% +first and so on + + + align:start position:0% +first and so on +plus + + align:start position:0% +plus + + + align:start position:0% +plus +other rotations about the new axes after + + align:start position:0% +other rotations about the new axes after + + + align:start position:0% +other rotations about the new axes after +you rotate or about the original axes + + align:start position:0% +you rotate or about the original axes + + + align:start position:0% +you rotate or about the original axes +anyway as a result of this as google + + align:start position:0% +anyway as a result of this as google + + + align:start position:0% +anyway as a result of this as google +points out there are 24 different + + align:start position:0% +points out there are 24 different + + + align:start position:0% +points out there are 24 different +definitions for euler angle and there + + align:start position:0% +definitions for euler angle and there + + + align:start position:0% +definitions for euler angle and there +hasn't been an international meeting to + + align:start position:0% +hasn't been an international meeting to + + + align:start position:0% +hasn't been an international meeting to +say you know thou shalt use this one so + + align:start position:0% +say you know thou shalt use this one so + + + align:start position:0% +say you know thou shalt use this one so +it's it's pretty confusing + + align:start position:0% +it's it's pretty confusing + + + align:start position:0% +it's it's pretty confusing +then we have of course orthonormal + + align:start position:0% +then we have of course orthonormal + + + align:start position:0% +then we have of course orthonormal +matrices which i'm sure you're all very + + align:start position:0% +matrices which i'm sure you're all very + + + align:start position:0% +matrices which i'm sure you're all very +familiar with and they have these two + + align:start position:0% +familiar with and they have these two + + + align:start position:0% +familiar with and they have these two +constraints on them + + align:start position:0% +constraints on them + + + align:start position:0% +constraints on them +and then this one is a kind of exotic + + align:start position:0% +and then this one is a kind of exotic + + + align:start position:0% +and then this one is a kind of exotic +one + + align:start position:0% +one + + + align:start position:0% +one +this + + align:start position:0% +this + + + align:start position:0% +this +represents a rotation matrix in an + + align:start position:0% +represents a rotation matrix in an + + + align:start position:0% +represents a rotation matrix in an +exponential form so what does this mean + + align:start position:0% +exponential form so what does this mean + + + align:start position:0% +exponential form so what does this mean +well + + align:start position:0% +well + + + align:start position:0% +well +here this capital omega is that three by + + align:start position:0% +here this capital omega is that three by + + + align:start position:0% +here this capital omega is that three by +three skew symmetric matrix that you get + + align:start position:0% +three skew symmetric matrix that you get + + + align:start position:0% +three skew symmetric matrix that you get +for cross product + + align:start position:0% +for cross product + + + align:start position:0% +for cross product +and so what does it mean to have + + align:start position:0% +and so what does it mean to have + + + align:start position:0% +and so what does it mean to have +exponential with a matrix in the + + align:start position:0% +exponential with a matrix in the + + + align:start position:0% +exponential with a matrix in the +exponent well you just use the formula + + align:start position:0% +exponent well you just use the formula + + + align:start position:0% +exponent well you just use the formula +for + + align:start position:0% +for + + + align:start position:0% +for +e to the x except now x is the matrix + + align:start position:0% +e to the x except now x is the matrix + + + align:start position:0% +e to the x except now x is the matrix +instead of uh scalar so you're going to + + align:start position:0% +instead of uh scalar so you're going to + + + align:start position:0% +instead of uh scalar so you're going to +end up with you know 1 plus + + align:start position:0% +end up with you know 1 plus + + + align:start position:0% +end up with you know 1 plus +x plus + + align:start position:0% +x plus + + + align:start position:0% +x plus +1 half x squared and so on where x now + + align:start position:0% +1 half x squared and so on where x now + + + align:start position:0% +1 half x squared and so on where x now +is a matrix so you can make this work + + align:start position:0% +is a matrix so you can make this work + + + align:start position:0% +is a matrix so you can make this work +but we won't uh pursue this it's + + align:start position:0% +but we won't uh pursue this it's + + + align:start position:0% +but we won't uh pursue this it's +um + + align:start position:0% +um + + + align:start position:0% +um +the and the others so here's another one + + align:start position:0% +the and the others so here's another one + + + align:start position:0% +the and the others so here's another one +uh stereography + + align:start position:0% +uh stereography + + + align:start position:0% +uh stereography +so there are lots of projections of the + + align:start position:0% +so there are lots of projections of the + + + align:start position:0% +so there are lots of projections of the +sphere and you know there's a whole + + align:start position:0% +sphere and you know there's a whole + + + align:start position:0% +sphere and you know there's a whole +cottage industry dating back hundreds of + + align:start position:0% +cottage industry dating back hundreds of + + + align:start position:0% +cottage industry dating back hundreds of +years because people found it necessary + + align:start position:0% +years because people found it necessary + + + align:start position:0% +years because people found it necessary +to + + align:start position:0% +to + + + align:start position:0% +to +take the spherical or almost spherical + + align:start position:0% +take the spherical or almost spherical + + + align:start position:0% +take the spherical or almost spherical +earth and map it onto a plane so they + + align:start position:0% +earth and map it onto a plane so they + + + align:start position:0% +earth and map it onto a plane so they +could sell maps and so there are lots of + + align:start position:0% +could sell maps and so there are lots of + + + align:start position:0% +could sell maps and so there are lots of +these one of them + + align:start position:0% +these one of them + + + align:start position:0% +these one of them +is conformal that is it preserves angles + + align:start position:0% +is conformal that is it preserves angles + + + align:start position:0% +is conformal that is it preserves angles +and uh it's called stereography + + align:start position:0% +and uh it's called stereography + + + align:start position:0% +and uh it's called stereography +and as we said a rotation of a sphere + + align:start position:0% +and as we said a rotation of a sphere + + + align:start position:0% +and as we said a rotation of a sphere +induces rotation of the space so uh we + + align:start position:0% +induces rotation of the space so uh we + + + align:start position:0% +induces rotation of the space so uh we +can take a sphere map it onto the plane + + align:start position:0% +can take a sphere map it onto the plane + + + align:start position:0% +can take a sphere map it onto the plane +then mush things around in the plane and + + align:start position:0% +then mush things around in the plane and + + + align:start position:0% +then mush things around in the plane and +map them back onto the sphere + + align:start position:0% +map them back onto the sphere + + + align:start position:0% +map them back onto the sphere +and if we mush things around just the + + align:start position:0% +and if we mush things around just the + + + align:start position:0% +and if we mush things around just the +right way in the plane + + align:start position:0% +right way in the plane + + + align:start position:0% +right way in the plane +uh then we actually have induced the + + align:start position:0% +uh then we actually have induced the + + + align:start position:0% +uh then we actually have induced the +rotation on the sphere + + align:start position:0% +rotation on the sphere + + + align:start position:0% +rotation on the sphere +we'll look at a picture of that again + + align:start position:0% +we'll look at a picture of that again + + + align:start position:0% +we'll look at a picture of that again +we're not going to use that but it's + + align:start position:0% +we're not going to use that but it's + + + align:start position:0% +we're not going to use that but it's +kind of amusing + + align:start position:0% +kind of amusing + + + align:start position:0% +kind of amusing +the thing you do in the plane is to + + align:start position:0% +the thing you do in the plane is to + + + align:start position:0% +the thing you do in the plane is to +treat the plane as a complex plane and + + align:start position:0% +treat the plane as a complex plane and + + + align:start position:0% +treat the plane as a complex plane and +do some + + align:start position:0% +do some + + + align:start position:0% +do some +uh + + align:start position:0% +uh + + + align:start position:0% +uh +homogeneous transformation on that + + align:start position:0% +homogeneous transformation on that + + + align:start position:0% +homogeneous transformation on that +and then of course physicists you know + + align:start position:0% +and then of course physicists you know + + + align:start position:0% +and then of course physicists you know +have to invent their own stuff + + align:start position:0% +have to invent their own stuff + + + align:start position:0% +have to invent their own stuff +so there's a type of two by two complex + + align:start position:0% +so there's a type of two by two complex + + + align:start position:0% +so there's a type of two by two complex +matrix that can be used to represent + + align:start position:0% +matrix that can be used to represent + + + align:start position:0% +matrix that can be used to represent +rotation that paulie came up with + + align:start position:0% +rotation that paulie came up with + + + align:start position:0% +rotation that paulie came up with +the same man who's famous for saying + + align:start position:0% +the same man who's famous for saying + + + align:start position:0% +the same man who's famous for saying +you know that paper isn't even wrong + + align:start position:0% +you know that paper isn't even wrong + + + align:start position:0% +you know that paper isn't even wrong +as a criticism of one of his colleagues + + align:start position:0% +as a criticism of one of his colleagues + + + align:start position:0% +as a criticism of one of his colleagues +so uh two by two complex numbers that + + align:start position:0% +so uh two by two complex numbers that + + + align:start position:0% +so uh two by two complex numbers that +sounds like eight degrees of freedom + + align:start position:0% +sounds like eight degrees of freedom + + + align:start position:0% +sounds like eight degrees of freedom +uh well they're not just any they have + + align:start position:0% +uh well they're not just any they have + + + align:start position:0% +uh well they're not just any they have +to be hermitian + + align:start position:0% +to be hermitian + + + align:start position:0% +to be hermitian +and they have to be unitary so it turns + + align:start position:0% +and they have to be unitary so it turns + + + align:start position:0% +and they have to be unitary so it turns +out that after you do that the only + + align:start position:0% +out that after you do that the only + + + align:start position:0% +out that after you do that the only +three degrees of freedom left + + align:start position:0% +three degrees of freedom left + + + align:start position:0% +three degrees of freedom left +then we get the euler parameters + + align:start position:0% +then we get the euler parameters + + + align:start position:0% +then we get the euler parameters +sometimes also called + + align:start position:0% +sometimes also called + + + align:start position:0% +sometimes also called +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +gonzales parameters rodriguez parameters + + align:start position:0% +gonzales parameters rodriguez parameters + + + align:start position:0% +gonzales parameters rodriguez parameters +excuse me + + align:start position:0% +excuse me + + + align:start position:0% +excuse me +and then we get to unit quaternions now + + align:start position:0% +and then we get to unit quaternions now + + + align:start position:0% +and then we get to unit quaternions now +of course there's a relation between all + + align:start position:0% +of course there's a relation between all + + + align:start position:0% +of course there's a relation between all +of them and in fact uh + + align:start position:0% +of them and in fact uh + + + align:start position:0% +of them and in fact uh +it's important to be able to convert + + align:start position:0% +it's important to be able to convert + + + align:start position:0% +it's important to be able to convert +between them + + align:start position:0% +between them + + + align:start position:0% +between them +and uh we'll do some of that and it's a + + align:start position:0% +and uh we'll do some of that and it's a + + + align:start position:0% +and uh we'll do some of that and it's a +little bit like + + align:start position:0% +little bit like + + + align:start position:0% +little bit like +many other problems where + + align:start position:0% +many other problems where + + + align:start position:0% +many other problems where +you're trying to solve something and it + + align:start position:0% +you're trying to solve something and it + + + align:start position:0% +you're trying to solve something and it +turns out if you have the right + + align:start position:0% +turns out if you have the right + + + align:start position:0% +turns out if you have the right +representation + + align:start position:0% +representation + + + align:start position:0% +representation +the answer is easy and so often the + + align:start position:0% +the answer is easy and so often the + + + align:start position:0% +the answer is easy and so often the +problem then ends up being the + + align:start position:0% +problem then ends up being the + + + align:start position:0% +problem then ends up being the +conversion and so then you find that + + align:start position:0% +conversion and so then you find that + + + align:start position:0% +conversion and so then you find that +well the conversion is complex just like + + align:start position:0% +well the conversion is complex just like + + + align:start position:0% +well the conversion is complex just like +you know in the trivial case we could + + align:start position:0% +you know in the trivial case we could + + + align:start position:0% +you know in the trivial case we could +have polar coordinates versus cartesian + + align:start position:0% +have polar coordinates versus cartesian + + + align:start position:0% +have polar coordinates versus cartesian +coordinates and maybe the answer in the + + align:start position:0% +coordinates and maybe the answer in the + + + align:start position:0% +coordinates and maybe the answer in the +car in polar coordinates is trivial but + + align:start position:0% +car in polar coordinates is trivial but + + + align:start position:0% +car in polar coordinates is trivial but +it's not in cartesian coordinates and + + align:start position:0% +it's not in cartesian coordinates and + + + align:start position:0% +it's not in cartesian coordinates and +then you're left with a conversion well + + align:start position:0% +then you're left with a conversion well + + + align:start position:0% +then you're left with a conversion well +in that case the conversion's not too + + align:start position:0% +in that case the conversion's not too + + + align:start position:0% +in that case the conversion's not too +hard but + + align:start position:0% +hard but + + + align:start position:0% +hard but +here sometimes it is + + align:start position:0% +here sometimes it is + + + align:start position:0% +here sometimes it is +okay so + + align:start position:0% +okay so + + + align:start position:0% +okay so +uh let's start with that this is + + align:start position:0% +uh let's start with that this is + + + align:start position:0% +uh let's start with that this is +rodriguez rodriguez was a + + align:start position:0% +rodriguez rodriguez was a + + + align:start position:0% +rodriguez rodriguez was a +banker + + align:start position:0% +banker + + + align:start position:0% +banker +in paris and apparently he found banking + + align:start position:0% +in paris and apparently he found banking + + + align:start position:0% +in paris and apparently he found banking +a fairly boring profession because he + + align:start position:0% +a fairly boring profession because he + + + align:start position:0% +a fairly boring profession because he +spent his nights doing math and so this + + align:start position:0% +spent his nights doing math and so this + + + align:start position:0% +spent his nights doing math and so this +is one of his results basically um the + + align:start position:0% +is one of his results basically um the + + + align:start position:0% +is one of his results basically um the +operations we're going to want to do uh + + align:start position:0% +operations we're going to want to do uh + + + align:start position:0% +operations we're going to want to do uh +two one operation is take a vector and + + align:start position:0% +two one operation is take a vector and + + + align:start position:0% +two one operation is take a vector and +rotate it or find out what that vector + + align:start position:0% +rotate it or find out what that vector + + + align:start position:0% +rotate it or find out what that vector +is in a rotated coordinate system + + align:start position:0% +is in a rotated coordinate system + + + align:start position:0% +is in a rotated coordinate system +equivalent problem the other one is + + align:start position:0% +equivalent problem the other one is + + + align:start position:0% +equivalent problem the other one is +composing rotations we've rotated a + + align:start position:0% +composing rotations we've rotated a + + + align:start position:0% +composing rotations we've rotated a +little bit in this around this axis now + + align:start position:0% +little bit in this around this axis now + + + align:start position:0% +little bit in this around this axis now +we're going to rotate about another axis + + align:start position:0% +we're going to rotate about another axis + + + align:start position:0% +we're going to rotate about another axis +what is the overall result and that + + align:start position:0% +what is the overall result and that + + + align:start position:0% +what is the overall result and that +turns out to be you know non-trivial so + + align:start position:0% +turns out to be you know non-trivial so + + + align:start position:0% +turns out to be you know non-trivial so +this here + + align:start position:0% +this here + + + align:start position:0% +this here +is addressing that first problem so we + + align:start position:0% +is addressing that first problem so we + + + align:start position:0% +is addressing that first problem so we +have a vector r + + align:start position:0% +have a vector r + + + align:start position:0% +have a vector r +and we have an axis of rotation that's + + align:start position:0% +and we have an axis of rotation that's + + + align:start position:0% +and we have an axis of rotation that's +uh here you know vertical + + align:start position:0% +uh here you know vertical + + + align:start position:0% +uh here you know vertical +and + + align:start position:0% +and + + + align:start position:0% +and +we're going to rotate through an angle + + align:start position:0% +we're going to rotate through an angle + + + align:start position:0% +we're going to rotate through an angle +theta about that axis and that will take + + align:start position:0% +theta about that axis and that will take + + + align:start position:0% +theta about that axis and that will take +us to a new position + + align:start position:0% +us to a new position + + + align:start position:0% +us to a new position +r + + align:start position:0% +r + + + align:start position:0% +r +prime and the question is you know how + + align:start position:0% +prime and the question is you know how + + + align:start position:0% +prime and the question is you know how +do you compute r prime + + align:start position:0% +do you compute r prime + + + align:start position:0% +do you compute r prime +well if we first convert it to a 2d + + align:start position:0% +well if we first convert it to a 2d + + + align:start position:0% +well if we first convert it to a 2d +problem you know in this plane indicated + + align:start position:0% +problem you know in this plane indicated + + + align:start position:0% +problem you know in this plane indicated +by this ellipse then it's very easy + + align:start position:0% +by this ellipse then it's very easy + + + align:start position:0% +by this ellipse then it's very easy +because we just take this vector + + align:start position:0% +because we just take this vector + + + align:start position:0% +because we just take this vector +and that vector and combine them in a + + align:start position:0% +and that vector and combine them in a + + + align:start position:0% +and that vector and combine them in a +weighted fashion + + align:start position:0% +weighted fashion + + + align:start position:0% +weighted fashion +so + + align:start position:0% +so + + + align:start position:0% +so +this + + align:start position:0% +this + + + align:start position:0% +this +dotted vector is + + align:start position:0% +dotted vector is + + + align:start position:0% +dotted vector is +this vector times cosine theta plus this + + align:start position:0% +this vector times cosine theta plus this + + + align:start position:0% +this vector times cosine theta plus this +vector times sine theta + + align:start position:0% +vector times sine theta + + + align:start position:0% +vector times sine theta +so + + align:start position:0% +so + + + align:start position:0% +so +you can see how when theta is zero the + + align:start position:0% +you can see how when theta is zero the + + + align:start position:0% +you can see how when theta is zero the +dotted vector will be equal to this one + + align:start position:0% +dotted vector will be equal to this one + + + align:start position:0% +dotted vector will be equal to this one +and when theta is equal to one uh pi + + align:start position:0% +and when theta is equal to one uh pi + + + align:start position:0% +and when theta is equal to one uh pi +over two it'll be equal to this vector + + align:start position:0% +over two it'll be equal to this vector + + + align:start position:0% +over two it'll be equal to this vector +and all the way along it retains its its + + align:start position:0% +and all the way along it retains its its + + + align:start position:0% +and all the way along it retains its its +length and so on so in 2d rotation as we + + align:start position:0% +length and so on so in 2d rotation as we + + + align:start position:0% +length and so on so in 2d rotation as we +know is very simple then and like + + align:start position:0% +know is very simple then and like + + + align:start position:0% +know is very simple then and like +mathematicians want to often do we + + align:start position:0% +mathematicians want to often do we + + + align:start position:0% +mathematicians want to often do we +reduce a complicated problem to a + + align:start position:0% +reduce a complicated problem to a + + + align:start position:0% +reduce a complicated problem to a +simpler one we already know how to solve + + align:start position:0% +simpler one we already know how to solve + + + align:start position:0% +simpler one we already know how to solve +but that's in this plane and so we first + + align:start position:0% +but that's in this plane and so we first + + + align:start position:0% +but that's in this plane and so we first +have to figure out what what these two + + align:start position:0% +have to figure out what what these two + + + align:start position:0% +have to figure out what what these two +vectors are that we are combining using + + align:start position:0% +vectors are that we are combining using + + + align:start position:0% +vectors are that we are combining using +cosine and sine and so first of all this + + align:start position:0% +cosine and sine and so first of all this + + + align:start position:0% +cosine and sine and so first of all this +one here so how do we get that one well + + align:start position:0% +one here so how do we get that one well + + + align:start position:0% +one here so how do we get that one well +we take r and we subtract out + + align:start position:0% +we take r and we subtract out + + + align:start position:0% +we take r and we subtract out +this vector + + align:start position:0% +this vector + + + align:start position:0% +this vector +right and the difference is going to be + + align:start position:0% +right and the difference is going to be + + + align:start position:0% +right and the difference is going to be +this vector here + + align:start position:0% +this vector here + + + align:start position:0% +this vector here +well um that means that we need to know + + align:start position:0% +well um that means that we need to know + + + align:start position:0% +well um that means that we need to know +what this vector is well that's just + + align:start position:0% +what this vector is well that's just + + + align:start position:0% +what this vector is well that's just +projecting r onto omega and since omega + + align:start position:0% +projecting r onto omega and since omega + + + align:start position:0% +projecting r onto omega and since omega +is the unit vector it's very easy + + align:start position:0% +is the unit vector it's very easy + + + align:start position:0% +is the unit vector it's very easy +there's a formula + + align:start position:0% +there's a formula + + + align:start position:0% +there's a formula +and so therefore this vector is r minus + + align:start position:0% +and so therefore this vector is r minus + + + align:start position:0% +and so therefore this vector is r minus +that thing + + align:start position:0% +that thing + + + align:start position:0% +that thing +and then finally we need to know what + + align:start position:0% +and then finally we need to know what + + + align:start position:0% +and then finally we need to know what +this vector is and basically that vector + + align:start position:0% +this vector is and basically that vector + + + align:start position:0% +this vector is and basically that vector +has to be perpendicular to omega + + align:start position:0% +has to be perpendicular to omega + + + align:start position:0% +has to be perpendicular to omega +and it has to be perpendicular to this + + align:start position:0% +and it has to be perpendicular to this + + + align:start position:0% +and it has to be perpendicular to this +because in this plane it's pi over two + + align:start position:0% +because in this plane it's pi over two + + + align:start position:0% +because in this plane it's pi over two +away from that vector right so by taking + + align:start position:0% +away from that vector right so by taking + + + align:start position:0% +away from that vector right so by taking +the cross product of uh of um uh + + align:start position:0% +the cross product of uh of um uh + + + align:start position:0% +the cross product of uh of um uh +let's see this this thing here with this + + align:start position:0% +let's see this this thing here with this + + + align:start position:0% +let's see this this thing here with this +thing here we end up with after + + align:start position:0% +thing here we end up with after + + + align:start position:0% +thing here we end up with after +simplification just omega cross r and it + + align:start position:0% +simplification just omega cross r and it + + + align:start position:0% +simplification just omega cross r and it +makes sense because it's going to be + + align:start position:0% +makes sense because it's going to be + + + align:start position:0% +makes sense because it's going to be +perpendicular to r and it's going to be + + align:start position:0% +perpendicular to r and it's going to be + + + align:start position:0% +perpendicular to r and it's going to be +perpendicular to omega anyway you put + + align:start position:0% +perpendicular to omega anyway you put + + + align:start position:0% +perpendicular to omega anyway you put +all of those things together you get + + align:start position:0% +all of those things together you get + + + align:start position:0% +all of those things together you get +this formula so r prime the the vector + + align:start position:0% +this formula so r prime the the vector + + + align:start position:0% +this formula so r prime the the vector +after rotation is cosine theta r the + + align:start position:0% +after rotation is cosine theta r the + + + align:start position:0% +after rotation is cosine theta r the +vector before rotation uh plus uh these + + align:start position:0% +vector before rotation uh plus uh these + + + align:start position:0% +vector before rotation uh plus uh these +terms + + align:start position:0% +terms + + + align:start position:0% +terms +and you know you can see that rotation's + + align:start position:0% +and you know you can see that rotation's + + + align:start position:0% +and you know you can see that rotation's +not quite that trivial so + + align:start position:0% +not quite that trivial so + + + align:start position:0% +not quite that trivial so +anyway so uh we'll + + align:start position:0% +anyway so uh we'll + + + align:start position:0% +anyway so uh we'll +so axis and angle is a useful notation + + align:start position:0% +so axis and angle is a useful notation + + + align:start position:0% +so axis and angle is a useful notation +and it's often a good way to visualize + + align:start position:0% +and it's often a good way to visualize + + + align:start position:0% +and it's often a good way to visualize +things you know it's easy to say okay + + align:start position:0% +things you know it's easy to say okay + + + align:start position:0% +things you know it's easy to say okay +we're rotating about the x-axis through + + align:start position:0% +we're rotating about the x-axis through + + + align:start position:0% +we're rotating about the x-axis through +90 degrees easy to understand what it is + + align:start position:0% +90 degrees easy to understand what it is + + + align:start position:0% +90 degrees easy to understand what it is +what's the disadvantage the disadvantage + + align:start position:0% +what's the disadvantage the disadvantage + + + align:start position:0% +what's the disadvantage the disadvantage +is if it composition if you have two + + align:start position:0% +is if it composition if you have two + + + align:start position:0% +is if it composition if you have two +rotations given as axes and angle + + align:start position:0% +rotations given as axes and angle + + + align:start position:0% +rotations given as axes and angle +how do you combine them into a single we + + align:start position:0% +how do you combine them into a single we + + + align:start position:0% +how do you combine them into a single we +know by euler's theorem there's a single + + align:start position:0% +know by euler's theorem there's a single + + + align:start position:0% +know by euler's theorem there's a single +rotation that uh represents the + + align:start position:0% +rotation that uh represents the + + + align:start position:0% +rotation that uh represents the +combination + + align:start position:0% +combination + + + align:start position:0% +combination +but how do you combine them well it + + align:start position:0% +but how do you combine them well it + + + align:start position:0% +but how do you combine them well it +turns out + + align:start position:0% +turns out + + + align:start position:0% +turns out +what i would do is convert both of these + + align:start position:0% +what i would do is convert both of these + + + align:start position:0% +what i would do is convert both of these +to some other form like + + align:start position:0% +to some other form like + + + align:start position:0% +to some other form like +orthonormal matrices multiply the normal + + align:start position:0% +orthonormal matrices multiply the normal + + + align:start position:0% +orthonormal matrices multiply the normal +matrices go back to this form so so + + align:start position:0% +matrices go back to this form so so + + + align:start position:0% +matrices go back to this form so so +that's a disadvantage there is no it's + + align:start position:0% +that's a disadvantage there is no it's + + + align:start position:0% +that's a disadvantage there is no it's +you can rotate vectors that's the one + + align:start position:0% +you can rotate vectors that's the one + + + align:start position:0% +you can rotate vectors that's the one +operation we want it's hard to do uh + + align:start position:0% +operation we want it's hard to do uh + + + align:start position:0% +operation we want it's hard to do uh +composition of rotation so + + align:start position:0% +composition of rotation so + + + align:start position:0% +composition of rotation so +uh okay well i will skip this this is + + align:start position:0% +uh okay well i will skip this this is + + + align:start position:0% +uh okay well i will skip this this is +the exponential + + align:start position:0% +the exponential + + + align:start position:0% +the exponential +the algebra view of things and + + align:start position:0% +the algebra view of things and + + + align:start position:0% +the algebra view of things and +that too let's forget that i just wanted + + align:start position:0% +that too let's forget that i just wanted + + + align:start position:0% +that too let's forget that i just wanted +to point uh + + align:start position:0% +to point uh + + + align:start position:0% +to point uh +this one which we mentioned + + align:start position:0% +this one which we mentioned + + + align:start position:0% +this one which we mentioned +so here the idea is that here's our + + align:start position:0% +so here the idea is that here's our + + + align:start position:0% +so here the idea is that here's our +sphere that we're going to rotate and we + + align:start position:0% +sphere that we're going to rotate and we + + + align:start position:0% +sphere that we're going to rotate and we +project it onto a plane which happens to + + align:start position:0% +project it onto a plane which happens to + + + align:start position:0% +project it onto a plane which happens to +be tangent at the north pole + + align:start position:0% +be tangent at the north pole + + + align:start position:0% +be tangent at the north pole +and this projection if your center of + + align:start position:0% +and this projection if your center of + + + align:start position:0% +and this projection if your center of +projection is the south pole so you go + + align:start position:0% +projection is the south pole so you go + + + align:start position:0% +projection is the south pole so you go +from the south pole to a point on the + + align:start position:0% +from the south pole to a point on the + + + align:start position:0% +from the south pole to a point on the +surface and that + + align:start position:0% +surface and that + + + align:start position:0% +surface and that +then extend that line until it hits that + + align:start position:0% +then extend that line until it hits that + + + align:start position:0% +then extend that line until it hits that +plane + + align:start position:0% +plane + + + align:start position:0% +plane +and you'll see a couple of things one of + + align:start position:0% +and you'll see a couple of things one of + + + align:start position:0% +and you'll see a couple of things one of +them is you can map the whole sphere + + align:start position:0% +them is you can map the whole sphere + + + align:start position:0% +them is you can map the whole sphere +onto a plane + + align:start position:0% +onto a plane + + + align:start position:0% +onto a plane +well except the south pole right + + align:start position:0% +well except the south pole right + + + align:start position:0% +well except the south pole right +the other one you can see is + + align:start position:0% +the other one you can see is + + + align:start position:0% +the other one you can see is +areas are going to be distorted right + + align:start position:0% +areas are going to be distorted right + + + align:start position:0% +areas are going to be distorted right +because if we're dealing with + + align:start position:0% +because if we're dealing with + + + align:start position:0% +because if we're dealing with +say alaska up here it's going to be + + align:start position:0% +say alaska up here it's going to be + + + align:start position:0% +say alaska up here it's going to be +mapped onto the plane without much + + align:start position:0% +mapped onto the plane without much + + + align:start position:0% +mapped onto the plane without much +magnification but if we're looking at + + align:start position:0% +magnification but if we're looking at + + + align:start position:0% +magnification but if we're looking at +australia you know it's going to come + + align:start position:0% +australia you know it's going to come + + + align:start position:0% +australia you know it's going to come +out way over here it's going to be huge + + align:start position:0% +out way over here it's going to be huge + + + align:start position:0% +out way over here it's going to be huge +so + + align:start position:0% +so + + + align:start position:0% +so +this particular map projection + + align:start position:0% +this particular map projection + + + align:start position:0% +this particular map projection +is actually + + align:start position:0% +is actually + + + align:start position:0% +is actually +used for the polar regions because most + + align:start position:0% +used for the polar regions because most + + + align:start position:0% +used for the polar regions because most +of the other map projections don't work + + align:start position:0% +of the other map projections don't work + + + align:start position:0% +of the other map projections don't work +very well there + + align:start position:0% +very well there + + + align:start position:0% +very well there +but it does have that feature and why is + + align:start position:0% +but it does have that feature and why is + + + align:start position:0% +but it does have that feature and why is +it liked so much well because it doesn't + + align:start position:0% +it liked so much well because it doesn't + + + align:start position:0% +it liked so much well because it doesn't +distort shapes + + align:start position:0% +distort shapes + + + align:start position:0% +distort shapes +so and it preserves angles most now all + + align:start position:0% +so and it preserves angles most now all + + + align:start position:0% +so and it preserves angles most now all +other projections have the property that + + align:start position:0% +other projections have the property that + + + align:start position:0% +other projections have the property that +they will distort shapes they will + + align:start position:0% +they will distort shapes they will + + + align:start position:0% +they will distort shapes they will +distort areas you have your choice you + + align:start position:0% +distort areas you have your choice you + + + align:start position:0% +distort areas you have your choice you +know you can pick + + align:start position:0% +know you can pick + + + align:start position:0% +know you can pick +projections that preserve area you can + + align:start position:0% +projections that preserve area you can + + + align:start position:0% +projections that preserve area you can +pick projections that preserve shape + + align:start position:0% +pick projections that preserve shape + + + align:start position:0% +pick projections that preserve shape +angles + + align:start position:0% +angles + + + align:start position:0% +angles +but you can't do both + + align:start position:0% +but you can't do both + + + align:start position:0% +but you can't do both +okay so uh we start off we take our + + align:start position:0% +okay so uh we start off we take our + + + align:start position:0% +okay so uh we start off we take our +sphere we project it onto this pla map + + align:start position:0% +sphere we project it onto this pla map + + + align:start position:0% +sphere we project it onto this pla map +this plane which is the complex plane + + align:start position:0% +this plane which is the complex plane + + + align:start position:0% +this plane which is the complex plane +then in that complex plane we do this + + align:start position:0% +then in that complex plane we do this + + + align:start position:0% +then in that complex plane we do this +operation so z is a complex variable + + align:start position:0% +operation so z is a complex variable + + + align:start position:0% +operation so z is a complex variable +coordinate in this plane + + align:start position:0% +coordinate in this plane + + + align:start position:0% +coordinate in this plane +and z prime is its new position + + align:start position:0% +and z prime is its new position + + + align:start position:0% +and z prime is its new position +so + + align:start position:0% + + + + align:start position:0% + +and a b c d are + + align:start position:0% +and a b c d are + + + align:start position:0% +and a b c d are +complex numbers + + align:start position:0% +complex numbers + + + align:start position:0% +complex numbers +so + + align:start position:0% +so + + + align:start position:0% +so +everything in that plane is going to get + + align:start position:0% +everything in that plane is going to get + + + align:start position:0% +everything in that plane is going to get +moved around and now we project it back + + align:start position:0% +moved around and now we project it back + + + align:start position:0% +moved around and now we project it back +on the sphere and the amazing thing is + + align:start position:0% +on the sphere and the amazing thing is + + + align:start position:0% +on the sphere and the amazing thing is +that the pattern on the sphere is just a + + align:start position:0% +that the pattern on the sphere is just a + + + align:start position:0% +that the pattern on the sphere is just a +rotated version of what it was before + + align:start position:0% +rotated version of what it was before + + + align:start position:0% +rotated version of what it was before +and therefore we can think of rotation + + align:start position:0% +and therefore we can think of rotation + + + align:start position:0% +and therefore we can think of rotation +or in three space + + align:start position:0% +or in three space + + + align:start position:0% +or in three space +instead in terms of some operation in + + align:start position:0% +instead in terms of some operation in + + + align:start position:0% +instead in terms of some operation in +the complex plane which is pretty + + align:start position:0% +the complex plane which is pretty + + + align:start position:0% +the complex plane which is pretty +amazing + + align:start position:0% + + + + align:start position:0% + +so that's yet another representation + + align:start position:0% +so that's yet another representation + + + align:start position:0% +so that's yet another representation +okay so what are the desirable + + align:start position:0% +okay so what are the desirable + + + align:start position:0% +okay so what are the desirable +properties we already mentioned some of + + align:start position:0% +properties we already mentioned some of + + + align:start position:0% +properties we already mentioned some of +them we we need to be able to rotate + + align:start position:0% +them we we need to be able to rotate + + + align:start position:0% +them we we need to be able to rotate +vectors or equivalently rotate + + align:start position:0% +vectors or equivalently rotate + + + align:start position:0% +vectors or equivalently rotate +coordinate systems we but also we need + + align:start position:0% +coordinate systems we but also we need + + + align:start position:0% +coordinate systems we but also we need +to be able to compose rotations + + align:start position:0% +to be able to compose rotations + + + align:start position:0% +to be able to compose rotations +we would like to have an intuitive + + align:start position:0% +we would like to have an intuitive + + + align:start position:0% +we would like to have an intuitive +representation you know like axis and + + align:start position:0% +representation you know like axis and + + + align:start position:0% +representation you know like axis and +angle sort of intuitive it's easy to + + align:start position:0% +angle sort of intuitive it's easy to + + + align:start position:0% +angle sort of intuitive it's easy to +understand what that is whereas you look + + align:start position:0% +understand what that is whereas you look + + + align:start position:0% +understand what that is whereas you look +at a rotational matrix you look at the + + align:start position:0% +at a rotational matrix you look at the + + + align:start position:0% +at a rotational matrix you look at the +numbers you know + + align:start position:0% +numbers you know + + + align:start position:0% +numbers you know +what do they mean + + align:start position:0% +what do they mean + + + align:start position:0% +what do they mean +i don't know you you multiply a vector + + align:start position:0% +i don't know you you multiply a vector + + + align:start position:0% +i don't know you you multiply a vector +and see what happens but the numbers + + align:start position:0% +and see what happens but the numbers + + + align:start position:0% +and see what happens but the numbers +don't directly mean anything + + align:start position:0% +don't directly mean anything + + + align:start position:0% +don't directly mean anything +if you know a little bit more about it + + align:start position:0% +if you know a little bit more about it + + + align:start position:0% +if you know a little bit more about it +you say well if i look at the trace + + align:start position:0% +you say well if i look at the trace + + + align:start position:0% +you say well if i look at the trace +with the sum of diagonal elements it's i + + align:start position:0% +with the sum of diagonal elements it's i + + + align:start position:0% +with the sum of diagonal elements it's i +don't know + + align:start position:0% +don't know + + + align:start position:0% +don't know +2 times 1 minus the cosine of the angle + + align:start position:0% +2 times 1 minus the cosine of the angle + + + align:start position:0% +2 times 1 minus the cosine of the angle +of rotation but it's not very intuitive + + align:start position:0% +of rotation but it's not very intuitive + + + align:start position:0% +of rotation but it's not very intuitive +then is it redundant well orthonormal + + align:start position:0% +then is it redundant well orthonormal + + + align:start position:0% +then is it redundant well orthonormal +matrices are a prime example of + + align:start position:0% +matrices are a prime example of + + + align:start position:0% +matrices are a prime example of +something that's definitely not + + align:start position:0% +something that's definitely not + + + align:start position:0% +something that's definitely not +redundant + + align:start position:0% +redundant + + + align:start position:0% +redundant +because we have nine numbers to + + align:start position:0% +because we have nine numbers to + + + align:start position:0% +because we have nine numbers to +represent three things + + align:start position:0% + + + + align:start position:0% + +right that's a very good point so so + + align:start position:0% +right that's a very good point so so + + + align:start position:0% +right that's a very good point so so +much for my story about it not being + + align:start position:0% +much for my story about it not being + + + align:start position:0% +much for my story about it not being +intuitive + + align:start position:0% +intuitive + + + align:start position:0% +intuitive +well if you think about rotating uh the + + align:start position:0% +well if you think about rotating uh the + + + align:start position:0% +well if you think about rotating uh the +x-axis + + align:start position:0% +x-axis + + + align:start position:0% +x-axis +ie one zero zero multiply the matrix by + + align:start position:0% +ie one zero zero multiply the matrix by + + + align:start position:0% +ie one zero zero multiply the matrix by +that you get the first column + + align:start position:0% +that you get the first column + + + align:start position:0% +that you get the first column +so uh as he's pointing out the first + + align:start position:0% +so uh as he's pointing out the first + + + align:start position:0% +so uh as he's pointing out the first +column is a significant vector it's what + + align:start position:0% +column is a significant vector it's what + + + align:start position:0% +column is a significant vector it's what +happens to the x-axis second column is + + align:start position:0% +happens to the x-axis second column is + + + align:start position:0% +happens to the x-axis second column is +what happens to the y-axis + + align:start position:0% +what happens to the y-axis + + + align:start position:0% +what happens to the y-axis +third column is what happens to the + + align:start position:0% +third column is what happens to the + + + align:start position:0% +third column is what happens to the +z-axis so + + align:start position:0% +z-axis so + + + align:start position:0% +z-axis so +you can understand the rotation matrix + + align:start position:0% +you can understand the rotation matrix + + + align:start position:0% +you can understand the rotation matrix +that way + + align:start position:0% +that way + + + align:start position:0% +that way +and similarly you can talk about the the + + align:start position:0% +and similarly you can talk about the the + + + align:start position:0% +and similarly you can talk about the the +rows going in the other direction + + align:start position:0% +rows going in the other direction + + + align:start position:0% +rows going in the other direction +but you know you wouldn't know the axis + + align:start position:0% +but you know you wouldn't know the axis + + + align:start position:0% +but you know you wouldn't know the axis +of rotation or the angle of rotation so + + align:start position:0% +of rotation or the angle of rotation so + + + align:start position:0% +of rotation or the angle of rotation so +but yes that's a good point okay + + align:start position:0% +but yes that's a good point okay + + + align:start position:0% +but yes that's a good point okay +redundant so let's see + + align:start position:0% + + + + align:start position:0% + +axis an angle well axis an angle is kind + + align:start position:0% +axis an angle well axis an angle is kind + + + align:start position:0% +axis an angle well axis an angle is kind +of redundant because if we have a vector + + align:start position:0% +of redundant because if we have a vector + + + align:start position:0% +of redundant because if we have a vector +it has three components plus an angle is + + align:start position:0% +it has three components plus an angle is + + + align:start position:0% +it has three components plus an angle is +four + + align:start position:0% +four + + + align:start position:0% +four +gibbs vector is not redundant because + + align:start position:0% +gibbs vector is not redundant because + + + align:start position:0% +gibbs vector is not redundant because +we've + + align:start position:0% +we've + + + align:start position:0% +we've +you know + + align:start position:0% +you know + + + align:start position:0% +you know +multiplied the vector by the tangent of + + align:start position:0% +multiplied the vector by the tangent of + + + align:start position:0% +multiplied the vector by the tangent of +theta over two + + align:start position:0% +theta over two + + + align:start position:0% +theta over two +but we don't want singularities + + align:start position:0% +but we don't want singularities + + + align:start position:0% +but we don't want singularities +gibbs vector has a singularity so + + align:start position:0% +gibbs vector has a singularity so + + + align:start position:0% +gibbs vector has a singularity so +we'd also like it to be computationally + + align:start position:0% +we'd also like it to be computationally + + + align:start position:0% +we'd also like it to be computationally +efficient + + align:start position:0% +efficient + + + align:start position:0% +efficient +and we'll get into that a little bit and + + align:start position:0% +and we'll get into that a little bit and + + + align:start position:0% +and we'll get into that a little bit and +we want to be able to do lots of things + + align:start position:0% +we want to be able to do lots of things + + + align:start position:0% +we want to be able to do lots of things +for example interpolate orientation so + + align:start position:0% +for example interpolate orientation so + + + align:start position:0% +for example interpolate orientation so +in graphics + + align:start position:0% +in graphics + + + align:start position:0% +in graphics +we might often have + + align:start position:0% +we might often have + + + align:start position:0% +we might often have +some + + align:start position:0% +some + + + align:start position:0% +some +person performing some + + align:start position:0% +person performing some + + + align:start position:0% +person performing some +dance or action in the world + + align:start position:0% +dance or action in the world + + + align:start position:0% +dance or action in the world +and we would like the artist to only + + align:start position:0% +and we would like the artist to only + + + align:start position:0% +and we would like the artist to only +have to specify certain distinct points + + align:start position:0% +have to specify certain distinct points + + + align:start position:0% +have to specify certain distinct points +rather than you know every frame + + align:start position:0% +rather than you know every frame + + + align:start position:0% +rather than you know every frame +and so we'll need to interpolate well if + + align:start position:0% +and so we'll need to interpolate well if + + + align:start position:0% +and so we'll need to interpolate well if +that person is rotating how do we + + align:start position:0% +that person is rotating how do we + + + align:start position:0% +that person is rotating how do we +interpolate how do you do a partial + + align:start position:0% +interpolate how do you do a partial + + + align:start position:0% +interpolate how do you do a partial +rotation + + align:start position:0% +rotation + + + align:start position:0% +rotation +and so you know you might say well half + + align:start position:0% +and so you know you might say well half + + + align:start position:0% +and so you know you might say well half +a rotation that's the square root of the + + align:start position:0% +a rotation that's the square root of the + + + align:start position:0% +a rotation that's the square root of the +rotation matrix + + align:start position:0% +rotation matrix + + + align:start position:0% +rotation matrix +right because if you multiply that by + + align:start position:0% +right because if you multiply that by + + + align:start position:0% +right because if you multiply that by +itself you get the rotation matrix but + + align:start position:0% +itself you get the rotation matrix but + + + align:start position:0% +itself you get the rotation matrix but +what how do you get the square root of a + + align:start position:0% +what how do you get the square root of a + + + align:start position:0% +what how do you get the square root of a +matrix + + align:start position:0% +matrix + + + align:start position:0% +matrix +so + + align:start position:0% +so + + + align:start position:0% +so +that's something another thing we might + + align:start position:0% +that's something another thing we might + + + align:start position:0% +that's something another thing we might +want to do is get averages of ranges of + + align:start position:0% +want to do is get averages of ranges of + + + align:start position:0% +want to do is get averages of ranges of +rotation + + align:start position:0% +rotation + + + align:start position:0% +rotation +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +for us a big deal is going to be + + align:start position:0% +for us a big deal is going to be + + + align:start position:0% +for us a big deal is going to be +optimization we're going to try and fit + + align:start position:0% +optimization we're going to try and fit + + + align:start position:0% +optimization we're going to try and fit +coordinate system we're going to try and + + align:start position:0% +coordinate system we're going to try and + + + align:start position:0% +coordinate system we're going to try and +fit measurements to + + align:start position:0% +fit measurements to + + + align:start position:0% +fit measurements to +models and in that case we need to be + + align:start position:0% +models and in that case we need to be + + + align:start position:0% +models and in that case we need to be +able to do things like take a derivative + + align:start position:0% +able to do things like take a derivative + + + align:start position:0% +able to do things like take a derivative +and set the result equal to zero well + + align:start position:0% +and set the result equal to zero well + + + align:start position:0% +and set the result equal to zero well +the derivative with respect to a + + align:start position:0% +the derivative with respect to a + + + align:start position:0% +the derivative with respect to a +rotational matrix that you know doesn't + + align:start position:0% +rotational matrix that you know doesn't + + + align:start position:0% +rotational matrix that you know doesn't +make a lot of sense + + align:start position:0% +make a lot of sense + + + align:start position:0% +make a lot of sense +what is it well something with nine + + align:start position:0% +what is it well something with nine + + + align:start position:0% +what is it well something with nine +components but you know how do you + + align:start position:0% +components but you know how do you + + + align:start position:0% +components but you know how do you +enforce the constraints + + align:start position:0% +enforce the constraints + + + align:start position:0% +enforce the constraints +then in some cases where we can't get a + + align:start position:0% +then in some cases where we can't get a + + + align:start position:0% +then in some cases where we can't get a +closed form solution + + align:start position:0% +closed form solution + + + align:start position:0% +closed form solution +we might want to sample that space and + + align:start position:0% +we might want to sample that space and + + + align:start position:0% +we might want to sample that space and +you know try to try + + align:start position:0% +you know try to try + + + align:start position:0% +you know try to try +some subsid but we'd like to sample the + + align:start position:0% +some subsid but we'd like to sample the + + + align:start position:0% +some subsid but we'd like to sample the +space in an efficient way which means we + + align:start position:0% +space in an efficient way which means we + + + align:start position:0% +space in an efficient way which means we +want to sample it uniformly so if it was + + align:start position:0% +want to sample it uniformly so if it was + + + align:start position:0% +want to sample it uniformly so if it was +a translation space we just you know + + align:start position:0% +a translation space we just you know + + + align:start position:0% +a translation space we just you know +chop up space into + + align:start position:0% +chop up space into + + + align:start position:0% +chop up space into +voxels + + align:start position:0% +voxels + + + align:start position:0% +voxels +equally spaced + + align:start position:0% +equally spaced + + + align:start position:0% +equally spaced +and we'd be done or if we + + align:start position:0% +and we'd be done or if we + + + align:start position:0% +and we'd be done or if we +go into for a random sampling we could + + align:start position:0% +go into for a random sampling we could + + + align:start position:0% +go into for a random sampling we could +just + + align:start position:0% +just + + + align:start position:0% +just +generate a random x between the range + + align:start position:0% +generate a random x between the range + + + align:start position:0% +generate a random x between the range +and the random y between the certain in + + align:start position:0% +and the random y between the certain in + + + align:start position:0% +and the random y between the certain in +a certain range and the z in a certain + + align:start position:0% +a certain range and the z in a certain + + + align:start position:0% +a certain range and the z in a certain +range but how do you do that for + + align:start position:0% +range but how do you do that for + + + align:start position:0% +range but how do you do that for +rotations now if you did it in euler + + align:start position:0% +rotations now if you did it in euler + + + align:start position:0% +rotations now if you did it in euler +angles you could say okay well i'll take + + align:start position:0% +angles you could say okay well i'll take + + + align:start position:0% +angles you could say okay well i'll take +the first angle + + align:start position:0% +the first angle + + + align:start position:0% +the first angle +between minus 90 and plus 90 and then + + align:start position:0% +between minus 90 and plus 90 and then + + + align:start position:0% +between minus 90 and plus 90 and then +the second angle and so on and you get + + align:start position:0% +the second angle and so on and you get + + + align:start position:0% +the second angle and so on and you get +into a non-uniform sampling of the space + + align:start position:0% +into a non-uniform sampling of the space + + + align:start position:0% +into a non-uniform sampling of the space +for example you know much easier example + + align:start position:0% +for example you know much easier example + + + align:start position:0% +for example you know much easier example +is + + align:start position:0% +is + + + align:start position:0% +is +on the sphere + + align:start position:0% +on the sphere + + + align:start position:0% +on the sphere +we can use latitude and longitude as + + align:start position:0% +we can use latitude and longitude as + + + align:start position:0% +we can use latitude and longitude as +coordinates + + align:start position:0% +coordinates + + + align:start position:0% +coordinates +but if you use that to control your + + align:start position:0% +but if you use that to control your + + + align:start position:0% +but if you use that to control your +sampling you're going to sample much + + align:start position:0% +sampling you're going to sample much + + + align:start position:0% +sampling you're going to sample much +more closely near the two poles right so + + align:start position:0% +more closely near the two poles right so + + + align:start position:0% +more closely near the two poles right so +that's um + + align:start position:0% +that's um + + + align:start position:0% +that's um +you know one more add one more dimension + + align:start position:0% +you know one more add one more dimension + + + align:start position:0% +you know one more add one more dimension +and you get the problem for uh rotations + + align:start position:0% +and you get the problem for uh rotations + + + align:start position:0% +and you get the problem for uh rotations +so the idea of having a space of no + + align:start position:0% +so the idea of having a space of no + + + align:start position:0% +so the idea of having a space of no +rotations is very + + align:start position:0% +rotations is very + + + align:start position:0% +rotations is very +attractive because then we can + + align:start position:0% +attractive because then we can + + + align:start position:0% +attractive because then we can +tessellate that space we can sample it + + align:start position:0% +tessellate that space we can sample it + + + align:start position:0% +tessellate that space we can sample it +uniformly or randomly we can compute + + align:start position:0% +uniformly or randomly we can compute + + + align:start position:0% +uniformly or randomly we can compute +averages or whatever + + align:start position:0% +averages or whatever + + + align:start position:0% +averages or whatever +so here are some of the problems we + + align:start position:0% +so here are some of the problems we + + + align:start position:0% +so here are some of the problems we +already talked about + + align:start position:0% +already talked about + + + align:start position:0% +already talked about +you know the orthonormal matrices + + align:start position:0% +you know the orthonormal matrices + + + align:start position:0% +you know the orthonormal matrices +they're redundant and the constraints + + align:start position:0% +they're redundant and the constraints + + + align:start position:0% +they're redundant and the constraints +are complicated + + align:start position:0% +are complicated + + + align:start position:0% +are complicated +euler angles don't make it easy to + + align:start position:0% +euler angles don't make it easy to + + + align:start position:0% +euler angles don't make it easy to +compose rotations just as with angle and + + align:start position:0% +compose rotations just as with angle and + + + align:start position:0% +compose rotations just as with angle and +axis notation best thing you can do is + + align:start position:0% +axis notation best thing you can do is + + + align:start position:0% +axis notation best thing you can do is +convert it to orthonormal matrix and + + align:start position:0% +convert it to orthonormal matrix and + + + align:start position:0% +convert it to orthonormal matrix and +multiply + + align:start position:0% +multiply + + + align:start position:0% +multiply +and then there's gimbal lock + + align:start position:0% +and then there's gimbal lock + + + align:start position:0% +and then there's gimbal lock +so + + align:start position:0% + + + + align:start position:0% + +i know you're all too young for this but + + align:start position:0% +i know you're all too young for this but + + + align:start position:0% +i know you're all too young for this but +there was a time when man went to the + + align:start position:0% +there was a time when man went to the + + + align:start position:0% +there was a time when man went to the +moon which was a very exciting time and + + align:start position:0% +moon which was a very exciting time and + + + align:start position:0% +moon which was a very exciting time and +when you listened on television + + align:start position:0% +when you listened on television + + + align:start position:0% +when you listened on television +and you ignored the stupid commentators + + align:start position:0% +and you ignored the stupid commentators + + + align:start position:0% +and you ignored the stupid commentators +that were talking over the + + align:start position:0% +that were talking over the + + + align:start position:0% +that were talking over the +communication from the cabin you'd hear + + align:start position:0% +communication from the cabin you'd hear + + + align:start position:0% +communication from the cabin you'd hear +them talk about + + align:start position:0% +them talk about + + + align:start position:0% +them talk about +approaching gimbal lock so what was that + + align:start position:0% +approaching gimbal lock so what was that + + + align:start position:0% +approaching gimbal lock so what was that +well they draper lab built their + + align:start position:0% +well they draper lab built their + + + align:start position:0% +well they draper lab built their +navigation system + + align:start position:0% +navigation system + + + align:start position:0% +navigation system +and it had gyroscopes in it and + + align:start position:0% +and it had gyroscopes in it and + + + align:start position:0% +and it had gyroscopes in it and +gyroscopes basically + + align:start position:0% +gyroscopes basically + + + align:start position:0% +gyroscopes basically +have three + + align:start position:0% +have three + + + align:start position:0% +have three +that type of gyroscope has three axes + + align:start position:0% +that type of gyroscope has three axes + + + align:start position:0% +that type of gyroscope has three axes +and it has a + + align:start position:0% +and it has a + + + align:start position:0% +and it has a +part that is spinning at high speed and + + align:start position:0% +part that is spinning at high speed and + + + align:start position:0% +part that is spinning at high speed and +wants to continue spinning around that + + align:start position:0% +wants to continue spinning around that + + + align:start position:0% +wants to continue spinning around that +axis and then the + + align:start position:0% +axis and then the + + + align:start position:0% +axis and then the +the cage basically + + align:start position:0% +the cage basically + + + align:start position:0% +the cage basically +allows the spacecraft to rotate about + + align:start position:0% +allows the spacecraft to rotate about + + + align:start position:0% +allows the spacecraft to rotate about +that fixed direction + + align:start position:0% +that fixed direction + + + align:start position:0% +that fixed direction +but + + align:start position:0% +but + + + align:start position:0% +but +as with euler angles + + align:start position:0% +as with euler angles + + + align:start position:0% +as with euler angles +you can get to a situation where two of + + align:start position:0% +you can get to a situation where two of + + + align:start position:0% +you can get to a situation where two of +the axes line up and then you've lost + + align:start position:0% +the axes line up and then you've lost + + + align:start position:0% +the axes line up and then you've lost +the degree of freedom and if you move + + align:start position:0% +the degree of freedom and if you move + + + align:start position:0% +the degree of freedom and if you move +through that point you've basically lost + + align:start position:0% +through that point you've basically lost + + + align:start position:0% +through that point you've basically lost +your orientation in space so they were + + align:start position:0% +your orientation in space so they were + + + align:start position:0% +your orientation in space so they were +carefully instructed not to + + align:start position:0% +carefully instructed not to + + + align:start position:0% +carefully instructed not to +go through that point because their + + align:start position:0% +go through that point because their + + + align:start position:0% +go through that point because their +automated systems wouldn't wouldn't work + + align:start position:0% +automated systems wouldn't wouldn't work + + + align:start position:0% +automated systems wouldn't wouldn't work +correctly and so + + align:start position:0% +correctly and so + + + align:start position:0% +correctly and so +that's exactly the problem with euler + + align:start position:0% +that's exactly the problem with euler + + + align:start position:0% +that's exactly the problem with euler +angles that when you rotate one of them + + align:start position:0% +angles that when you rotate one of them + + + align:start position:0% +angles that when you rotate one of them +through 90 degrees it lines up with the + + align:start position:0% +through 90 degrees it lines up with the + + + align:start position:0% +through 90 degrees it lines up with the +next one and you've lost the degree of + + align:start position:0% +next one and you've lost the degree of + + + align:start position:0% +next one and you've lost the degree of +freedom + + align:start position:0% +freedom + + + align:start position:0% +freedom +and so + + align:start position:0% +and so + + + align:start position:0% +and so +by the way how do you solve it well + + align:start position:0% +by the way how do you solve it well + + + align:start position:0% +by the way how do you solve it well +the easiest way is have four axes + + align:start position:0% +the easiest way is have four axes + + + align:start position:0% +the easiest way is have four axes +and in that case unfortunately you can + + align:start position:0% +and in that case unfortunately you can + + + align:start position:0% +and in that case unfortunately you can +no longer treat it as a passive system + + align:start position:0% +no longer treat it as a passive system + + + align:start position:0% +no longer treat it as a passive system +you have to have an active system that + + align:start position:0% +you have to have an active system that + + + align:start position:0% +you have to have an active system that +drives the axis so that you never have + + align:start position:0% +drives the axis so that you never have + + + align:start position:0% +drives the axis so that you never have +two of them line up anyway + + align:start position:0% +two of them line up anyway + + + align:start position:0% +two of them line up anyway +euler angles gibbs vector had that + + align:start position:0% +euler angles gibbs vector had that + + + align:start position:0% +euler angles gibbs vector had that +singularity + + align:start position:0% +singularity + + + align:start position:0% +singularity +uh acts as an angle has the problem of + + align:start position:0% +uh acts as an angle has the problem of + + + align:start position:0% +uh acts as an angle has the problem of +the composing rotations and then of + + align:start position:0% +the composing rotations and then of + + + align:start position:0% +the composing rotations and then of +course we don't have a clear idea of + + align:start position:0% +course we don't have a clear idea of + + + align:start position:0% +course we don't have a clear idea of +what is the space of rotations + + align:start position:0% +what is the space of rotations + + + align:start position:0% +what is the space of rotations +so we get to hamilton + + align:start position:0% +so we get to hamilton + + + align:start position:0% +so we get to hamilton +who lived in dublin ireland + + align:start position:0% +who lived in dublin ireland + + + align:start position:0% +who lived in dublin ireland +and he was fascinated by + + align:start position:0% +and he was fascinated by + + + align:start position:0% +and he was fascinated by +algebraic couples so the view is that we + + align:start position:0% +algebraic couples so the view is that we + + + align:start position:0% +algebraic couples so the view is that we +think of complex numbers as pairs of + + align:start position:0% +think of complex numbers as pairs of + + + align:start position:0% +think of complex numbers as pairs of +reals and can we somehow + + align:start position:0% +reals and can we somehow + + + align:start position:0% +reals and can we somehow +generalize that + + align:start position:0% +generalize that + + + align:start position:0% +generalize that +and you want to have a nice algebra you + + align:start position:0% +and you want to have a nice algebra you + + + align:start position:0% +and you want to have a nice algebra you +want to be able to add subtract multiply + + align:start position:0% +want to be able to add subtract multiply + + + align:start position:0% +want to be able to add subtract multiply +and + + align:start position:0% +and + + + align:start position:0% +and +very important you want to be able to + + align:start position:0% +very important you want to be able to + + + align:start position:0% +very important you want to be able to +divide + + align:start position:0% +divide + + + align:start position:0% +divide +you i mean you can do all sorts of + + align:start position:0% +you i mean you can do all sorts of + + + align:start position:0% +you i mean you can do all sorts of +wonderful things but if you if you can + + align:start position:0% +wonderful things but if you if you can + + + align:start position:0% +wonderful things but if you if you can +do that then you can solve equations you + + align:start position:0% +do that then you can solve equations you + + + align:start position:0% +do that then you can solve equations you +know by subtracting + + align:start position:0% +know by subtracting + + + align:start position:0% +know by subtracting +cross multiplying doing all those things + + align:start position:0% +cross multiplying doing all those things + + + align:start position:0% +cross multiplying doing all those things +we're used to + + align:start position:0% +we're used to + + + align:start position:0% +we're used to +and so uh there was a lot of interest in + + align:start position:0% +and so uh there was a lot of interest in + + + align:start position:0% +and so uh there was a lot of interest in +physics particularly in dealing with + + align:start position:0% +physics particularly in dealing with + + + align:start position:0% +physics particularly in dealing with +vectors in space well they weren't + + align:start position:0% +vectors in space well they weren't + + + align:start position:0% +vectors in space well they weren't +called vectors but dealing with points + + align:start position:0% +called vectors but dealing with points + + + align:start position:0% +called vectors but dealing with points +in space and so the natural thing was + + align:start position:0% +in space and so the natural thing was + + + align:start position:0% +in space and so the natural thing was +you know let's go from real numbers to + + align:start position:0% +you know let's go from real numbers to + + + align:start position:0% +you know let's go from real numbers to +complex numbers to triples + + align:start position:0% +complex numbers to triples + + + align:start position:0% +complex numbers to triples +and + + align:start position:0% +and + + + align:start position:0% +and +then what can we do with the triples + + align:start position:0% +then what can we do with the triples + + + align:start position:0% +then what can we do with the triples +well you can multiply them and of course + + align:start position:0% +well you can multiply them and of course + + + align:start position:0% +well you can multiply them and of course +the dot products not much use for this + + align:start position:0% +the dot products not much use for this + + + align:start position:0% +the dot products not much use for this +purpose because it's a scalar + + align:start position:0% +purpose because it's a scalar + + + align:start position:0% +purpose because it's a scalar +cross product well the trouble is if + + align:start position:0% +cross product well the trouble is if + + + align:start position:0% +cross product well the trouble is if +you've got a cross b + + align:start position:0% +you've got a cross b + + + align:start position:0% +you've got a cross b +you know c equals a cross b can you say + + align:start position:0% +you know c equals a cross b can you say + + + align:start position:0% +you know c equals a cross b can you say +uh a equals c divided by b uh no so you + + align:start position:0% +uh a equals c divided by b uh no so you + + + align:start position:0% +uh a equals c divided by b uh no so you +know so that was his problem and it + + align:start position:0% +know so that was his problem and it + + + align:start position:0% +know so that was his problem and it +really uh puzzled him for for quite a + + align:start position:0% +really uh puzzled him for for quite a + + + align:start position:0% +really uh puzzled him for for quite a +while + + align:start position:0% +while + + + align:start position:0% +while +and he'd he trained his children to + + align:start position:0% +and he'd he trained his children to + + + align:start position:0% +and he'd he trained his children to +every morning he came down for breakfast + + align:start position:0% +every morning he came down for breakfast + + + align:start position:0% +every morning he came down for breakfast +to ask him uh papa can you multiply + + align:start position:0% +to ask him uh papa can you multiply + + + align:start position:0% +to ask him uh papa can you multiply +triplets yet + + align:start position:0% +triplets yet + + + align:start position:0% +triplets yet +which were these vectors + + align:start position:0% +which were these vectors + + + align:start position:0% +which were these vectors +we later call vectors + + align:start position:0% +we later call vectors + + + align:start position:0% +we later call vectors +and then uh on this fateful day + + align:start position:0% +and then uh on this fateful day + + + align:start position:0% +and then uh on this fateful day +uh he + + align:start position:0% +uh he + + + align:start position:0% +uh he +he's he got it + + align:start position:0% +he's he got it + + + align:start position:0% +he's he got it +and he went with his wife on his usual + + align:start position:0% +and he went with his wife on his usual + + + align:start position:0% +and he went with his wife on his usual +sunday stroll through + + align:start position:0% +sunday stroll through + + + align:start position:0% +sunday stroll through +dublin + + align:start position:0% +dublin + + + align:start position:0% +dublin +and + + align:start position:0% +and + + + align:start position:0% +and +he committed a criminal act on the + + align:start position:0% +he committed a criminal act on the + + + align:start position:0% +he committed a criminal act on the +bridge he engraved in graffiti the basic + + align:start position:0% +bridge he engraved in graffiti the basic + + + align:start position:0% +bridge he engraved in graffiti the basic +equation you need to solve this problem + + align:start position:0% +equation you need to solve this problem + + + align:start position:0% +equation you need to solve this problem +without explanation just the formula + + align:start position:0% +without explanation just the formula + + + align:start position:0% +without explanation just the formula +and then later when he described it he's + + align:start position:0% +and then later when he described it he's + + + align:start position:0% +and then later when he described it he's +saying + + align:start position:0% +saying + + + align:start position:0% +saying +and here they dawned on me the notion + + align:start position:0% +and here they dawned on me the notion + + + align:start position:0% +and here they dawned on me the notion +that we must admit in some sense a + + align:start position:0% +that we must admit in some sense a + + + align:start position:0% +that we must admit in some sense a +fourth dimension of space for the + + align:start position:0% +fourth dimension of space for the + + + align:start position:0% +fourth dimension of space for the +purpose of calculating with triples an + + align:start position:0% +purpose of calculating with triples an + + + align:start position:0% +purpose of calculating with triples an +electric circuit seemed to close and a + + align:start position:0% +electric circuit seemed to close and a + + + align:start position:0% +electric circuit seemed to close and a +spark flashed forth remember it was 1843 + + align:start position:0% +spark flashed forth remember it was 1843 + + + align:start position:0% +spark flashed forth remember it was 1843 +so you know there's a lot of excitement + + align:start position:0% +so you know there's a lot of excitement + + + align:start position:0% +so you know there's a lot of excitement +about electric stuff but long before + + align:start position:0% +about electric stuff but long before + + + align:start position:0% +about electric stuff but long before +tesla and edison + + align:start position:0% +tesla and edison + + + align:start position:0% +tesla and edison +and + + align:start position:0% +and + + + align:start position:0% +and +the key thing was that he decided you + + align:start position:0% +the key thing was that he decided you + + + align:start position:0% +the key thing was that he decided you +can't do it with three there's no way to + + align:start position:0% +can't do it with three there's no way to + + + align:start position:0% +can't do it with three there's no way to +do it with three but you can do it with + + align:start position:0% +do it with three but you can do it with + + + align:start position:0% +do it with three but you can do it with +four and so + + align:start position:0% +four and so + + + align:start position:0% +four and so +then he wrote a book which is basically + + align:start position:0% +then he wrote a book which is basically + + + align:start position:0% +then he wrote a book which is basically +incomprehensible it's like 800 pages of + + align:start position:0% +incomprehensible it's like 800 pages of + + + align:start position:0% +incomprehensible it's like 800 pages of +heavy math but we'll simplify it a lot + + align:start position:0% +heavy math but we'll simplify it a lot + + + align:start position:0% +heavy math but we'll simplify it a lot +so the insight was you can't do it with + + align:start position:0% +so the insight was you can't do it with + + + align:start position:0% +so the insight was you can't do it with +three components and then he took his q + + align:start position:0% +three components and then he took his q + + + align:start position:0% +three components and then he took his q +from complex numbers where we introduced + + align:start position:0% +from complex numbers where we introduced + + + align:start position:0% +from complex numbers where we introduced +a quote imaginary number and + + align:start position:0% +a quote imaginary number and + + + align:start position:0% +a quote imaginary number and +he said well maybe if we have more of + + align:start position:0% +he said well maybe if we have more of + + + align:start position:0% +he said well maybe if we have more of +them you know maybe there are other + + align:start position:0% +them you know maybe there are other + + + align:start position:0% +them you know maybe there are other +things when you square them they become + + align:start position:0% +things when you square them they become + + + align:start position:0% +things when you square them they become +minus one and so that was his key + + align:start position:0% +minus one and so that was his key + + + align:start position:0% +minus one and so that was his key +insight he used + + align:start position:0% +insight he used + + + align:start position:0% +insight he used +the notation i j k + + align:start position:0% +the notation i j k + + + align:start position:0% +the notation i j k +such that i squared and j squared and k + + align:start position:0% +such that i squared and j squared and k + + + align:start position:0% +such that i squared and j squared and k +squared are minus one and then very + + align:start position:0% +squared are minus one and then very + + + align:start position:0% +squared are minus one and then very +importantly he added this i j k equals + + align:start position:0% +importantly he added this i j k equals + + + align:start position:0% +importantly he added this i j k equals +minus one and this is what he engraved + + align:start position:0% +minus one and this is what he engraved + + + align:start position:0% +minus one and this is what he engraved +in the bridge + + align:start position:0% +in the bridge + + + align:start position:0% +in the bridge +and it's still there although heavily + + align:start position:0% +and it's still there although heavily + + + align:start position:0% +and it's still there although heavily +worn by mathematicians touching it to + + align:start position:0% +worn by mathematicians touching it to + + + align:start position:0% +worn by mathematicians touching it to +see if they can get the inside from + + align:start position:0% +see if they can get the inside from + + + align:start position:0% +see if they can get the inside from +uh anyway + + align:start position:0% +uh anyway + + + align:start position:0% +uh anyway +from those you can get everything else + + align:start position:0% +from those you can get everything else + + + align:start position:0% +from those you can get everything else +for example if you want to know what i j + + align:start position:0% +for example if you want to know what i j + + + align:start position:0% +for example if you want to know what i j +is well you just multiply i j k by k and + + align:start position:0% +is well you just multiply i j k by k and + + + align:start position:0% +is well you just multiply i j k by k and +you get k squared which is minus one so + + align:start position:0% +you get k squared which is minus one so + + + align:start position:0% +you get k squared which is minus one so +it's going to be minus one times you + + align:start position:0% +it's going to be minus one times you + + + align:start position:0% +it's going to be minus one times you +know and so on to get k + + align:start position:0% +know and so on to get k + + + align:start position:0% +know and so on to get k +so these others are all subsidiary he + + align:start position:0% +so these others are all subsidiary he + + + align:start position:0% +so these others are all subsidiary he +didn't bother engraving them he just + + align:start position:0% +didn't bother engraving them he just + + + align:start position:0% +didn't bother engraving them he just +took the uh + + align:start position:0% +took the uh + + + align:start position:0% +took the uh +important the multiplication is not + + align:start position:0% +important the multiplication is not + + + align:start position:0% +important the multiplication is not +commutative so you know i j is k j i is + + align:start position:0% +commutative so you know i j is k j i is + + + align:start position:0% +commutative so you know i j is k j i is +minus k and um + + align:start position:0% +minus k and um + + + align:start position:0% +minus k and um +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +that sort of corresponds to cross + + align:start position:0% +that sort of corresponds to cross + + + align:start position:0% +that sort of corresponds to cross +products so this kind of suggests a + + align:start position:0% +products so this kind of suggests a + + + align:start position:0% +products so this kind of suggests a +connection with + + align:start position:0% +connection with + + + align:start position:0% +connection with +vectors + + align:start position:0% + + + + align:start position:0% + +and so there are lots of different ways + + align:start position:0% +and so there are lots of different ways + + + align:start position:0% +and so there are lots of different ways +of thinking about quaternions + + align:start position:0% +of thinking about quaternions + + + align:start position:0% +of thinking about quaternions +one is just simply as a real part and + + align:start position:0% +one is just simply as a real part and + + + align:start position:0% +one is just simply as a real part and +three different flavors of imaginary + + align:start position:0% +three different flavors of imaginary + + + align:start position:0% +three different flavors of imaginary +parts rather than just one imaginary + + align:start position:0% +parts rather than just one imaginary + + + align:start position:0% +parts rather than just one imaginary +part + + align:start position:0% +part + + + align:start position:0% +part +but then you can take these three and + + align:start position:0% +but then you can take these three and + + + align:start position:0% +but then you can take these three and +think of them as a vector in space + + align:start position:0% +think of them as a vector in space + + + align:start position:0% +think of them as a vector in space +and treat the whole thing as a scalar q + + align:start position:0% +and treat the whole thing as a scalar q + + + align:start position:0% +and treat the whole thing as a scalar q +zero + + align:start position:0% +zero + + + align:start position:0% +zero +plus this vector and use this notation + + align:start position:0% +plus this vector and use this notation + + + align:start position:0% +plus this vector and use this notation +which + + align:start position:0% +which + + + align:start position:0% +which +has a scalar comma vector part + + align:start position:0% +has a scalar comma vector part + + + align:start position:0% +has a scalar comma vector part +or you can just write it as a four + + align:start position:0% +or you can just write it as a four + + + align:start position:0% +or you can just write it as a four +vector a thing with four components + + align:start position:0% +vector a thing with four components + + + align:start position:0% +vector a thing with four components +so uh i use this notation with a little + + align:start position:0% +so uh i use this notation with a little + + + align:start position:0% +so uh i use this notation with a little +circle over it to denote a quaternion + + align:start position:0% +circle over it to denote a quaternion + + + align:start position:0% +circle over it to denote a quaternion +it's not standard so don't get confused + + align:start position:0% +it's not standard so don't get confused + + + align:start position:0% +it's not standard so don't get confused +by that but + + align:start position:0% +by that but + + + align:start position:0% +by that but +when i'm writing stuff it's very + + align:start position:0% +when i'm writing stuff it's very + + + align:start position:0% +when i'm writing stuff it's very +important for me to distinguish the + + align:start position:0% +important for me to distinguish the + + + align:start position:0% +important for me to distinguish the +scalar the vector and the quaternion so + + align:start position:0% +scalar the vector and the quaternion so + + + align:start position:0% +scalar the vector and the quaternion so +i use the little circle to denote that + + align:start position:0% +i use the little circle to denote that + + + align:start position:0% +i use the little circle to denote that +another way of thinking about + + align:start position:0% +another way of thinking about + + + align:start position:0% +another way of thinking about +quaternions is as four by four matrices + + align:start position:0% +quaternions is as four by four matrices + + + align:start position:0% +quaternions is as four by four matrices +and that brings us back to that + + align:start position:0% +and that brings us back to that + + + align:start position:0% +and that brings us back to that +isomorphism we had that was useful for + + align:start position:0% +isomorphism we had that was useful for + + + align:start position:0% +isomorphism we had that was useful for +cross products there will be an + + align:start position:0% +cross products there will be an + + + align:start position:0% +cross products there will be an +isomorphism + + align:start position:0% +isomorphism + + + align:start position:0% +isomorphism +of quaternions with 4x4 matrices + + align:start position:0% +of quaternions with 4x4 matrices + + + align:start position:0% +of quaternions with 4x4 matrices +that allows us to do + + align:start position:0% +that allows us to do + + + align:start position:0% +that allows us to do +multiplication and yet another way + + align:start position:0% +multiplication and yet another way + + + align:start position:0% +multiplication and yet another way +is to think of a complex composite of + + align:start position:0% +is to think of a complex composite of + + + align:start position:0% +is to think of a complex composite of +two complex numbers so you know complex + + align:start position:0% +two complex numbers so you know complex + + + align:start position:0% +two complex numbers so you know complex +numbers are real plus i times a real now + + align:start position:0% +numbers are real plus i times a real now + + + align:start position:0% +numbers are real plus i times a real now +imagine that you replace the real with + + align:start position:0% +imagine that you replace the real with + + + align:start position:0% +imagine that you replace the real with +complex numbers you've got something + + align:start position:0% +complex numbers you've got something + + + align:start position:0% +complex numbers you've got something +with four components because you've got + + align:start position:0% +with four components because you've got + + + align:start position:0% +with four components because you've got +to be careful because you've got two + + align:start position:0% +to be careful because you've got two + + + align:start position:0% +to be careful because you've got two +different types of imaginary things + + align:start position:0% +different types of imaginary things + + + align:start position:0% +different types of imaginary things +that's actually a way we aren't going to + + align:start position:0% +that's actually a way we aren't going to + + + align:start position:0% +that's actually a way we aren't going to +use but it's a way that leads you to + + align:start position:0% +use but it's a way that leads you to + + + align:start position:0% +use but it's a way that leads you to +other things for example you can + + align:start position:0% +other things for example you can + + + align:start position:0% +other things for example you can +use that idea again and now you get + + align:start position:0% +use that idea again and now you get + + + align:start position:0% +use that idea again and now you get +instead of four components eight + + align:start position:0% +instead of four components eight + + + align:start position:0% +instead of four components eight +and then again you can get sixteen + + align:start position:0% +and then again you can get sixteen + + + align:start position:0% +and then again you can get sixteen +components so you can build these + + align:start position:0% +components so you can build these + + + align:start position:0% +components so you can build these +algebras that have uh you know one two + + align:start position:0% +algebras that have uh you know one two + + + align:start position:0% +algebras that have uh you know one two +four eight sixteen components and they + + align:start position:0% +four eight sixteen components and they + + + align:start position:0% +four eight sixteen components and they +get weirder and weirder we're gonna + + align:start position:0% +get weirder and weirder we're gonna + + + align:start position:0% +get weirder and weirder we're gonna +stick with four that's as far as we need + + align:start position:0% +stick with four that's as far as we need + + + align:start position:0% +stick with four that's as far as we need +to go + + align:start position:0% +to go + + + align:start position:0% +to go +okay so um + + align:start position:0% +okay so um + + + align:start position:0% +okay so um +here's the view of multiplication using + + align:start position:0% +here's the view of multiplication using + + + align:start position:0% +here's the view of multiplication using +uh hamilton's uh basic uh uh explanation + + align:start position:0% +uh hamilton's uh basic uh uh explanation + + + align:start position:0% +uh hamilton's uh basic uh uh explanation +of how to multiply these things + + align:start position:0% +of how to multiply these things + + + align:start position:0% +of how to multiply these things +here two quaternions we're gonna + + align:start position:0% +here two quaternions we're gonna + + + align:start position:0% +here two quaternions we're gonna +multiply them and obviously we're gonna + + align:start position:0% +multiply them and obviously we're gonna + + + align:start position:0% +multiply them and obviously we're gonna +get 16 terms and then you know j times k + + align:start position:0% +get 16 terms and then you know j times k + + + align:start position:0% +get 16 terms and then you know j times k +is minus i + + align:start position:0% +is minus i + + + align:start position:0% +is minus i +um + + align:start position:0% +um + + + align:start position:0% +um +and so we can gather them up as again a + + align:start position:0% +and so we can gather them up as again a + + + align:start position:0% +and so we can gather them up as again a +scalar part + + align:start position:0% +scalar part + + + align:start position:0% +scalar part +and then these three um + + align:start position:0% +and then these three um + + + align:start position:0% +and then these three um +uh imaginary parts + + align:start position:0% +uh imaginary parts + + + align:start position:0% +uh imaginary parts +and that's you know that's the + + align:start position:0% +and that's you know that's the + + + align:start position:0% +and that's you know that's the +bottom baseline truth but it's kind of + + align:start position:0% +bottom baseline truth but it's kind of + + + align:start position:0% +bottom baseline truth but it's kind of +uh + + align:start position:0% +uh + + + align:start position:0% +uh +too detailed it's kind of hard to + + align:start position:0% +too detailed it's kind of hard to + + + align:start position:0% +too detailed it's kind of hard to +uh keep remember that + + align:start position:0% +uh keep remember that + + + align:start position:0% +uh keep remember that +and it's uh for us who are now remember + + align:start position:0% +and it's uh for us who are now remember + + + align:start position:0% +and it's uh for us who are now remember +this was before vectors + + align:start position:0% +this was before vectors + + + align:start position:0% +this was before vectors +but today we're all into vectors and + + align:start position:0% +but today we're all into vectors and + + + align:start position:0% +but today we're all into vectors and +scalars so in that notation it's a lot + + align:start position:0% +scalars so in that notation it's a lot + + + align:start position:0% +scalars so in that notation it's a lot +easier to write it this way so here's a + + align:start position:0% +easier to write it this way so here's a + + + align:start position:0% +easier to write it this way so here's a +quaternion p a quaternion q we multiply + + align:start position:0% +quaternion p a quaternion q we multiply + + + align:start position:0% +quaternion p a quaternion q we multiply +them together and we get this quaternion + + align:start position:0% +them together and we get this quaternion + + + align:start position:0% +them together and we get this quaternion +and the scalar part of it is just the + + align:start position:0% +and the scalar part of it is just the + + + align:start position:0% +and the scalar part of it is just the +scalar parts multiplied minus the dot + + align:start position:0% +scalar parts multiplied minus the dot + + + align:start position:0% +scalar parts multiplied minus the dot +product of the vector parts and so on + + align:start position:0% +product of the vector parts and so on + + + align:start position:0% +product of the vector parts and so on +and it's non-commutative why because it + + align:start position:0% +and it's non-commutative why because it + + + align:start position:0% +and it's non-commutative why because it +includes this cross product at the end + + align:start position:0% +includes this cross product at the end + + + align:start position:0% +includes this cross product at the end +here so if we if we interchange these + + align:start position:0% +here so if we if we interchange these + + + align:start position:0% +here so if we if we interchange these +two we're going to get q cross p which + + align:start position:0% +two we're going to get q cross p which + + + align:start position:0% +two we're going to get q cross p which +is of course minus p cross + + align:start position:0% +is of course minus p cross + + + align:start position:0% +is of course minus p cross +okay so this is actually a way we're + + align:start position:0% +okay so this is actually a way we're + + + align:start position:0% +okay so this is actually a way we're +going to use it + + align:start position:0% +going to use it + + + align:start position:0% +going to use it +just it's much more compact than this + + align:start position:0% +just it's much more compact than this + + + align:start position:0% +just it's much more compact than this +uh here's another notation that's + + align:start position:0% +uh here's another notation that's + + + align:start position:0% +uh here's another notation that's +sometimes uh very useful and this is + + align:start position:0% +sometimes uh very useful and this is + + + align:start position:0% +sometimes uh very useful and this is +analogous to the isomorphism we had + + align:start position:0% +analogous to the isomorphism we had + + + align:start position:0% +analogous to the isomorphism we had +between vectors and skew symmetric three + + align:start position:0% +between vectors and skew symmetric three + + + align:start position:0% +between vectors and skew symmetric three +by three matrices here we have + + align:start position:0% +by three matrices here we have + + + align:start position:0% +by three matrices here we have +isomorphism between a quaternion and a + + align:start position:0% +isomorphism between a quaternion and a + + + align:start position:0% +isomorphism between a quaternion and a +four by four + + align:start position:0% +four by four + + + align:start position:0% +four by four +uh matrix which happens to be orthogonal + + align:start position:0% +uh matrix which happens to be orthogonal + + + align:start position:0% +uh matrix which happens to be orthogonal +and if the quaternion is a unit + + align:start position:0% +and if the quaternion is a unit + + + align:start position:0% +and if the quaternion is a unit +quaternion it's also a unit + + align:start position:0% +quaternion it's also a unit + + + align:start position:0% +quaternion it's also a unit +normal so this actually in our case is + + align:start position:0% +normal so this actually in our case is + + + align:start position:0% +normal so this actually in our case is +typically a orthonormal four by four + + align:start position:0% +typically a orthonormal four by four + + + align:start position:0% +typically a orthonormal four by four +matrix + + align:start position:0% + + + + align:start position:0% + +and so this multiplication up here can + + align:start position:0% +and so this multiplication up here can + + + align:start position:0% +and so this multiplication up here can +be written as this product of a matrix + + align:start position:0% +be written as this product of a matrix + + + align:start position:0% +be written as this product of a matrix +times a vector and there's quite a bit + + align:start position:0% +times a vector and there's quite a bit + + + align:start position:0% +times a vector and there's quite a bit +of structure to this you can see you + + align:start position:0% +of structure to this you can see you + + + align:start position:0% +of structure to this you can see you +know the first column is just the + + align:start position:0% +know the first column is just the + + + align:start position:0% +know the first column is just the +quaternion p + + align:start position:0% +quaternion p + + + align:start position:0% +quaternion p +and then you can see that it's sort of + + align:start position:0% +and then you can see that it's sort of + + + align:start position:0% +and then you can see that it's sort of +skew symmetric except for the diagonal + + align:start position:0% +skew symmetric except for the diagonal + + + align:start position:0% +skew symmetric except for the diagonal +which would be zero if it was skew + + align:start position:0% +which would be zero if it was skew + + + align:start position:0% +which would be zero if it was skew +symmetric + + align:start position:0% +symmetric + + + align:start position:0% +symmetric +um + + align:start position:0% +um + + + align:start position:0% +um +and so uh we can write the product of + + align:start position:0% +and so uh we can write the product of + + + align:start position:0% +and so uh we can write the product of +two quaternions + + align:start position:0% +two quaternions + + + align:start position:0% +two quaternions +uh in that form so we can write p q so + + align:start position:0% +uh in that form so we can write p q so + + + align:start position:0% +uh in that form so we can write p q so +this is just like cross product you know + + align:start position:0% +this is just like cross product you know + + + align:start position:0% +this is just like cross product you know +where we said a cross b is some matrix + + align:start position:0% +where we said a cross b is some matrix + + + align:start position:0% +where we said a cross b is some matrix +times b similarly here p q can be + + align:start position:0% +times b similarly here p q can be + + + align:start position:0% +times b similarly here p q can be +written as this matrix times q and the + + align:start position:0% +written as this matrix times q and the + + + align:start position:0% +written as this matrix times q and the +matrix looks like this + + align:start position:0% +matrix looks like this + + + align:start position:0% +matrix looks like this +and the matrix is orthogonal and it's + + align:start position:0% +and the matrix is orthogonal and it's + + + align:start position:0% +and the matrix is orthogonal and it's +normal if it's a unit quaternion + + align:start position:0% +normal if it's a unit quaternion + + + align:start position:0% +normal if it's a unit quaternion +and + + align:start position:0% +and + + + align:start position:0% +and +if we get rid of p0 then it's skew + + align:start position:0% +if we get rid of p0 then it's skew + + + align:start position:0% +if we get rid of p0 then it's skew +symmetric + + align:start position:0% +symmetric + + + align:start position:0% +symmetric +and again just as with cross products we + + align:start position:0% +and again just as with cross products we + + + align:start position:0% +and again just as with cross products we +have the choice of either expanding the + + align:start position:0% +have the choice of either expanding the + + + align:start position:0% +have the choice of either expanding the +first part into a matrix or the second + + align:start position:0% +first part into a matrix or the second + + + align:start position:0% +first part into a matrix or the second +part so here's the other version + + align:start position:0% +part so here's the other version + + + align:start position:0% +part so here's the other version +where now we've + + align:start position:0% +where now we've + + + align:start position:0% +where now we've +turned q into a four by four matrix and + + align:start position:0% +turned q into a four by four matrix and + + + align:start position:0% +turned q into a four by four matrix and +this four by four matrix looks a lot + + align:start position:0% +this four by four matrix looks a lot + + + align:start position:0% +this four by four matrix looks a lot +like this one the first column is pretty + + align:start position:0% +like this one the first column is pretty + + + align:start position:0% +like this one the first column is pretty +much the same the first row is pretty + + align:start position:0% +much the same the first row is pretty + + + align:start position:0% +much the same the first row is pretty +much the same what's different is this + + align:start position:0% +much the same what's different is this + + + align:start position:0% +much the same what's different is this +three by three sub matrix is flipped + + align:start position:0% +three by three sub matrix is flipped + + + align:start position:0% +three by three sub matrix is flipped +it's it's a transpose + + align:start position:0% +it's it's a transpose + + + align:start position:0% +it's it's a transpose +so they're very similar but and this + + align:start position:0% +so they're very similar but and this + + + align:start position:0% +so they're very similar but and this +corresponds again to the fact that + + align:start position:0% +corresponds again to the fact that + + + align:start position:0% +corresponds again to the fact that +multiplication is non-commutative if + + align:start position:0% +multiplication is non-commutative if + + + align:start position:0% +multiplication is non-commutative if +those two pieces were the same then this + + align:start position:0% +those two pieces were the same then this + + + align:start position:0% +those two pieces were the same then this +whole operation would have been + + align:start position:0% +whole operation would have been + + + align:start position:0% +whole operation would have been +commutative + + align:start position:0% + + + + align:start position:0% + +okay so um + + align:start position:0% +okay so um + + + align:start position:0% +okay so um +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +now that we've got you know the basics + + align:start position:0% +now that we've got you know the basics + + + align:start position:0% +now that we've got you know the basics +and different ways of representing it uh + + align:start position:0% +and different ways of representing it uh + + + align:start position:0% +and different ways of representing it uh +it's easy to prove some of these uh + + align:start position:0% +it's easy to prove some of these uh + + + align:start position:0% +it's easy to prove some of these uh +basic results so first of all + + align:start position:0% +basic results so first of all + + + align:start position:0% +basic results so first of all +it's clear that it's not commutative and + + align:start position:0% +it's clear that it's not commutative and + + + align:start position:0% +it's clear that it's not commutative and +and + + align:start position:0% +and + + + align:start position:0% +and +it you know that's why we're talking + + align:start position:0% +it you know that's why we're talking + + + align:start position:0% +it you know that's why we're talking +about it we wouldn't be talking about it + + align:start position:0% +about it we wouldn't be talking about it + + + align:start position:0% +about it we wouldn't be talking about it +because commutative gives them there's + + align:start position:0% +because commutative gives them there's + + + align:start position:0% +because commutative gives them there's +no way that it can represent rotation uh + + align:start position:0% +no way that it can represent rotation uh + + + align:start position:0% +no way that it can represent rotation uh +it's associative and that's not too hard + + align:start position:0% +it's associative and that's not too hard + + + align:start position:0% +it's associative and that's not too hard +to prove just use the formula for + + align:start position:0% +to prove just use the formula for + + + align:start position:0% +to prove just use the formula for +multiplication it's just a bit of messy + + align:start position:0% +multiplication it's just a bit of messy + + + align:start position:0% +multiplication it's just a bit of messy +algebra + + align:start position:0% +algebra + + + align:start position:0% +algebra +then we define a conjugate and the + + align:start position:0% +then we define a conjugate and the + + + align:start position:0% +then we define a conjugate and the +conjugate in analogy with complex + + align:start position:0% +conjugate in analogy with complex + + + align:start position:0% +conjugate in analogy with complex +numbers just means you negate the + + align:start position:0% +numbers just means you negate the + + + align:start position:0% +numbers just means you negate the +imaginary part + + align:start position:0% +imaginary part + + + align:start position:0% +imaginary part +and then + + align:start position:0% +and then + + + align:start position:0% +and then +the next result you can get is that the + + align:start position:0% +the next result you can get is that the + + + align:start position:0% +the next result you can get is that the +conjugate of a product is the product of + + align:start position:0% +conjugate of a product is the product of + + + align:start position:0% +conjugate of a product is the product of +the conjugates in reverse order which is + + align:start position:0% +the conjugates in reverse order which is + + + align:start position:0% +the conjugates in reverse order which is +just like uh matrix multiplication + + align:start position:0% +just like uh matrix multiplication + + + align:start position:0% +just like uh matrix multiplication +a b all transposed is b transpose a + + align:start position:0% +a b all transposed is b transpose a + + + align:start position:0% +a b all transposed is b transpose a +transpose so there there's some + + align:start position:0% +transpose so there there's some + + + align:start position:0% +transpose so there there's some +analogies here and you you know if you + + align:start position:0% +analogies here and you you know if you + + + align:start position:0% +analogies here and you you know if you +into physics you'll realize that you + + align:start position:0% +into physics you'll realize that you + + + align:start position:0% +into physics you'll realize that you +know different heroes of physics had + + align:start position:0% +know different heroes of physics had + + + align:start position:0% +know different heroes of physics had +different uh + + align:start position:0% +different uh + + + align:start position:0% +different uh +ways of approaching quantum physics and + + align:start position:0% +ways of approaching quantum physics and + + + align:start position:0% +ways of approaching quantum physics and +some of them like to do it with a sort + + align:start position:0% +some of them like to do it with a sort + + + align:start position:0% +some of them like to do it with a sort +of complex number view and some of them + + align:start position:0% +of complex number view and some of them + + + align:start position:0% +of complex number view and some of them +like to do it with a matrix view and you + + align:start position:0% +like to do it with a matrix view and you + + + align:start position:0% +like to do it with a matrix view and you +can find that they're kind of equivalent + + align:start position:0% +can find that they're kind of equivalent + + + align:start position:0% +can find that they're kind of equivalent +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +so uh i've done a little of that and i'm + + align:start position:0% +so uh i've done a little of that and i'm + + + align:start position:0% +so uh i've done a little of that and i'm +going to do more of it + + align:start position:0% +going to do more of it + + + align:start position:0% +going to do more of it +and the main reason is that we can get a + + align:start position:0% +and the main reason is that we can get a + + + align:start position:0% +and the main reason is that we can get a +closed form solution because we can + + align:start position:0% +closed form solution because we can + + + align:start position:0% +closed form solution because we can +differentiate with respect to a + + align:start position:0% +differentiate with respect to a + + + align:start position:0% +differentiate with respect to a +quaternion we can't differentiate with + + align:start position:0% +quaternion we can't differentiate with + + + align:start position:0% +quaternion we can't differentiate with +respect to orthonormal matrix so that's + + align:start position:0% +respect to orthonormal matrix so that's + + + align:start position:0% +respect to orthonormal matrix so that's +kind of the main reason + + align:start position:0% +kind of the main reason + + + align:start position:0% +kind of the main reason +but there are these subsidiary reasons + + align:start position:0% +but there are these subsidiary reasons + + + align:start position:0% +but there are these subsidiary reasons +like if you can't get a closed form + + align:start position:0% +like if you can't get a closed form + + + align:start position:0% +like if you can't get a closed form +solution you can do a search in the + + align:start position:0% +solution you can do a search in the + + + align:start position:0% +solution you can do a search in the +space of rotations + + align:start position:0% +space of rotations + + + align:start position:0% +space of rotations +and you can sample that space + + align:start position:0% +and you can sample that space + + + align:start position:0% +and you can sample that space +efficiently either + + align:start position:0% +efficiently either + + + align:start position:0% +efficiently either +uniformly or randomly + + align:start position:0% +uniformly or randomly + + + align:start position:0% +uniformly or randomly +once you've got the notion of a space of + + align:start position:0% +once you've got the notion of a space of + + + align:start position:0% +once you've got the notion of a space of +rotation which is the case with + + align:start position:0% +rotation which is the case with + + + align:start position:0% +rotation which is the case with +quaternions + + align:start position:0% +quaternions + + + align:start position:0% +quaternions +okay so the few other + + align:start position:0% +okay so the few other + + + align:start position:0% +okay so the few other +dot product well the dot product you + + align:start position:0% +dot product well the dot product you + + + align:start position:0% +dot product well the dot product you +know if we think of it as a four vector + + align:start position:0% +know if we think of it as a four vector + + + align:start position:0% +know if we think of it as a four vector +it's just the ordinary dot product of a + + align:start position:0% +it's just the ordinary dot product of a + + + align:start position:0% +it's just the ordinary dot product of a +four vector if we think of it in terms + + align:start position:0% +four vector if we think of it in terms + + + align:start position:0% +four vector if we think of it in terms +of scalar and vector well then it's the + + align:start position:0% +of scalar and vector well then it's the + + + align:start position:0% +of scalar and vector well then it's the +product of the scalars plus the dot + + align:start position:0% +product of the scalars plus the dot + + + align:start position:0% +product of the scalars plus the dot +product of the vectors + + align:start position:0% +product of the vectors + + + align:start position:0% +product of the vectors +but you know underneath it's just q 0 + + align:start position:0% +but you know underneath it's just q 0 + + + align:start position:0% +but you know underneath it's just q 0 +squared plus q x squared plus + + align:start position:0% +squared plus q x squared plus + + + align:start position:0% +squared plus q x squared plus +sorry + + align:start position:0% +sorry + + + align:start position:0% +sorry +p 0 q 0 plus p x q x etc + + align:start position:0% +p 0 q 0 plus p x q x etc + + + align:start position:0% +p 0 q 0 plus p x q x etc +and therefore there's a norm we can + + align:start position:0% +and therefore there's a norm we can + + + align:start position:0% +and therefore there's a norm we can +define a norm + + align:start position:0% +define a norm + + + align:start position:0% +define a norm +and this is the perhaps the most + + align:start position:0% +and this is the perhaps the most + + + align:start position:0% +and this is the perhaps the most +important if we multiply + + align:start position:0% +important if we multiply + + + align:start position:0% +important if we multiply +q by its conjugate + + align:start position:0% +q by its conjugate + + + align:start position:0% +q by its conjugate +it turns out we get a real quantity + + align:start position:0% +it turns out we get a real quantity + + + align:start position:0% +it turns out we get a real quantity +there's no imaginary part + + align:start position:0% +there's no imaginary part + + + align:start position:0% +there's no imaginary part +and it's it's this + + align:start position:0% +and it's it's this + + + align:start position:0% +and it's it's this +uh it's uh the dot product of q + + align:start position:0% +uh it's uh the dot product of q + + + align:start position:0% +uh it's uh the dot product of q +with itself times e where e is this + + align:start position:0% +with itself times e where e is this + + + align:start position:0% +with itself times e where e is this +quaternion that + + align:start position:0% +quaternion that + + + align:start position:0% +quaternion that +has a scalar it's a scalar one and i + + align:start position:0% +has a scalar it's a scalar one and i + + + align:start position:0% +has a scalar it's a scalar one and i +could have just written one there but + + align:start position:0% +could have just written one there but + + + align:start position:0% +could have just written one there but +that looks sort of funny so i invented + + align:start position:0% +that looks sort of funny so i invented + + + align:start position:0% +that looks sort of funny so i invented +this symbol + + align:start position:0% +this symbol + + + align:start position:0% +this symbol +which is a quaternion that has + + align:start position:0% +which is a quaternion that has + + + align:start position:0% +which is a quaternion that has +no vector part + + align:start position:0% +no vector part + + + align:start position:0% +no vector part +and why is this important well if you + + align:start position:0% +and why is this important well if you + + + align:start position:0% +and why is this important well if you +can do that then you have division + + align:start position:0% +can do that then you have division + + + align:start position:0% +can do that then you have division +so + + align:start position:0% +so + + + align:start position:0% +so +the multiplicative inverse is is this + + align:start position:0% +the multiplicative inverse is is this + + + align:start position:0% +the multiplicative inverse is is this +and that was the problem with the + + align:start position:0% +and that was the problem with the + + + align:start position:0% +and that was the problem with the +triplets there was no way of defining an + + align:start position:0% +triplets there was no way of defining an + + + align:start position:0% +triplets there was no way of defining an +inverse + + align:start position:0% +inverse + + + align:start position:0% +inverse +and here here we can define an inverse + + align:start position:0% +and here here we can define an inverse + + + align:start position:0% +and here here we can define an inverse +well except for q equals 0 but then + + align:start position:0% +well except for q equals 0 but then + + + align:start position:0% +well except for q equals 0 but then +that's always a problem so + + align:start position:0% +that's always a problem so + + + align:start position:0% +that's always a problem so +and so this means for example that + + align:start position:0% + + + + align:start position:0% + +we can + + align:start position:0% +we can + + + align:start position:0% +we can +get the inverse of a rotation very + + align:start position:0% +get the inverse of a rotation very + + + align:start position:0% +get the inverse of a rotation very +easily first of all in the rotation + + align:start position:0% +easily first of all in the rotation + + + align:start position:0% +easily first of all in the rotation +we're going to be dealing with unit + + align:start position:0% +we're going to be dealing with unit + + + align:start position:0% +we're going to be dealing with unit +quaternions so q dot q is 1. so in the + + align:start position:0% +quaternions so q dot q is 1. so in the + + + align:start position:0% +quaternions so q dot q is 1. so in the +case of that + + align:start position:0% +case of that + + + align:start position:0% +case of that +unit quaternion representation the + + align:start position:0% +unit quaternion representation the + + + align:start position:0% +unit quaternion representation the +inverse is just the conjugate + + align:start position:0% +inverse is just the conjugate + + + align:start position:0% +inverse is just the conjugate +sort of like in the case of orthonormal + + align:start position:0% +sort of like in the case of orthonormal + + + align:start position:0% +sort of like in the case of orthonormal +matrices the inverse is just the + + align:start position:0% +matrices the inverse is just the + + + align:start position:0% +matrices the inverse is just the +transpose + + align:start position:0% +transpose + + + align:start position:0% +transpose +okay and then a few other sort of minor + + align:start position:0% +okay and then a few other sort of minor + + + align:start position:0% +okay and then a few other sort of minor +properties and you can just take those + + align:start position:0% +properties and you can just take those + + + align:start position:0% +properties and you can just take those +on faith or you can check them by doing + + align:start position:0% +on faith or you can check them by doing + + + align:start position:0% +on faith or you can check them by doing +the multiplications so the dot product + + align:start position:0% +the multiplications so the dot product + + + align:start position:0% +the multiplications so the dot product +of uh products is the product of dot + + align:start position:0% +of uh products is the product of dot + + + align:start position:0% +of uh products is the product of dot +products all surprising that + + align:start position:0% +products all surprising that + + + align:start position:0% +products all surprising that +and then + + align:start position:0% +and then + + + align:start position:0% +and then +this first line is the + + align:start position:0% +this first line is the + + + align:start position:0% +this first line is the +special case of the second line which is + + align:start position:0% +special case of the second line which is + + + align:start position:0% +special case of the second line which is +more useful in calculations + + align:start position:0% +more useful in calculations + + + align:start position:0% +more useful in calculations +and then this this one's pretty handy so + + align:start position:0% +and then this this one's pretty handy so + + + align:start position:0% +and then this this one's pretty handy so +what's happened here well sometimes we + + align:start position:0% +what's happened here well sometimes we + + + align:start position:0% +what's happened here well sometimes we +have a + + align:start position:0% +have a + + + align:start position:0% +have a +quaternion on one side we'd like to move + + align:start position:0% +quaternion on one side we'd like to move + + + align:start position:0% +quaternion on one side we'd like to move +it to the other side of a dot product + + align:start position:0% +it to the other side of a dot product + + + align:start position:0% +it to the other side of a dot product +and it turns out we can do that as long + + align:start position:0% +and it turns out we can do that as long + + + align:start position:0% +and it turns out we can do that as long +as we conjugate it + + align:start position:0% +as we conjugate it + + + align:start position:0% +as we conjugate it +so we've moved the cube from the left + + align:start position:0% +so we've moved the cube from the left + + + align:start position:0% +so we've moved the cube from the left +side of the dot to the right side of the + + align:start position:0% +side of the dot to the right side of the + + + align:start position:0% +side of the dot to the right side of the +dot and + + align:start position:0% +dot and + + + align:start position:0% +dot and +just conjugated it and it's easy to + + align:start position:0% +just conjugated it and it's easy to + + + align:start position:0% +just conjugated it and it's easy to +prove that you just multiply by you know + + align:start position:0% +prove that you just multiply by you know + + + align:start position:0% +prove that you just multiply by you know +cube conjugate and so on + + align:start position:0% +cube conjugate and so on + + + align:start position:0% +cube conjugate and so on +okay so uh so we're going to use unit + + align:start position:0% +okay so uh so we're going to use unit + + + align:start position:0% +okay so uh so we're going to use unit +quaternaries to represent rotation and + + align:start position:0% +quaternaries to represent rotation and + + + align:start position:0% +quaternaries to represent rotation and +we'll see right now how that's related + + align:start position:0% +we'll see right now how that's related + + + align:start position:0% +we'll see right now how that's related +to the other notations for rotation but + + align:start position:0% +to the other notations for rotation but + + + align:start position:0% +to the other notations for rotation but +we're dealing with vectors so what about + + align:start position:0% +we're dealing with vectors so what about + + + align:start position:0% +we're dealing with vectors so what about +vectors well we'll need to have a + + align:start position:0% +vectors well we'll need to have a + + + align:start position:0% +vectors well we'll need to have a +quaternion way of representing vectors + + align:start position:0% +quaternion way of representing vectors + + + align:start position:0% +quaternion way of representing vectors +and of course + + align:start position:0% +and of course + + + align:start position:0% +and of course +it's obvious we just leave out the + + align:start position:0% +it's obvious we just leave out the + + + align:start position:0% +it's obvious we just leave out the +scalar part conversely if we wanted to + + align:start position:0% +scalar part conversely if we wanted to + + + align:start position:0% +scalar part conversely if we wanted to +represent a scalar we could just leave + + align:start position:0% +represent a scalar we could just leave + + + align:start position:0% +represent a scalar we could just leave +out the vector part + + align:start position:0% +out the vector part + + + align:start position:0% +out the vector part +okay so we're going to convert our + + align:start position:0% +okay so we're going to convert our + + + align:start position:0% +okay so we're going to convert our +vectors in 3d to these funny uh + + align:start position:0% +vectors in 3d to these funny uh + + + align:start position:0% +vectors in 3d to these funny uh +quaternions purely imaginary quaternions + + align:start position:0% +quaternions purely imaginary quaternions + + + align:start position:0% +quaternions purely imaginary quaternions +uh + + align:start position:0% +uh + + + align:start position:0% +uh +manipulate them in that space and then + + align:start position:0% +manipulate them in that space and then + + + align:start position:0% +manipulate them in that space and then +bring them back into the into 3d + + align:start position:0% +bring them back into the into 3d + + + align:start position:0% +bring them back into the into 3d +um + + align:start position:0% +um + + + align:start position:0% +um +for this special case only of these + + align:start position:0% +for this special case only of these + + + align:start position:0% +for this special case only of these +types of quaternions + + align:start position:0% +types of quaternions + + + align:start position:0% +types of quaternions +there's lots of interesting properties + + align:start position:0% +there's lots of interesting properties + + + align:start position:0% +there's lots of interesting properties +first of all the conjugate of course is + + align:start position:0% +first of all the conjugate of course is + + + align:start position:0% +first of all the conjugate of course is +just negating it because conjugate means + + align:start position:0% +just negating it because conjugate means + + + align:start position:0% +just negating it because conjugate means +negating the imaginary part + + align:start position:0% +negating the imaginary part + + + align:start position:0% +negating the imaginary part +the dot product is just the dot product + + align:start position:0% +the dot product is just the dot product + + + align:start position:0% +the dot product is just the dot product +so this is the dot product of the + + align:start position:0% +so this is the dot product of the + + + align:start position:0% +so this is the dot product of the +quaternions this is the dot product of + + align:start position:0% +quaternions this is the dot product of + + + align:start position:0% +quaternions this is the dot product of +the corresponding vectors and since the + + align:start position:0% +the corresponding vectors and since the + + + align:start position:0% +the corresponding vectors and since the +scalar part is zero you know it's + + align:start position:0% +scalar part is zero you know it's + + + align:start position:0% +scalar part is zero you know it's +obvious that this is the case so we can + + align:start position:0% +obvious that this is the case so we can + + + align:start position:0% +obvious that this is the case so we can +easily compute dot products uh if we + + align:start position:0% +easily compute dot products uh if we + + + align:start position:0% +easily compute dot products uh if we +multiply two of these special + + align:start position:0% +multiply two of these special + + + align:start position:0% +multiply two of these special +quaternions we get this funny thing + + align:start position:0% +quaternions we get this funny thing + + + align:start position:0% +quaternions we get this funny thing +it has the dot product in it and the + + align:start position:0% +it has the dot product in it and the + + + align:start position:0% +it has the dot product in it and the +cross product + + align:start position:0% +cross product + + + align:start position:0% +cross product +and this is why some critics of this + + align:start position:0% +and this is why some critics of this + + + align:start position:0% +and this is why some critics of this +notation uh called it a hermaphrodite + + align:start position:0% +notation uh called it a hermaphrodite + + + align:start position:0% +notation uh called it a hermaphrodite +monster you know it's got both sexes + + align:start position:0% +monster you know it's got both sexes + + + align:start position:0% +monster you know it's got both sexes +built into it dot products and cross + + align:start position:0% +built into it dot products and cross + + + align:start position:0% +built into it dot products and cross +products and they they thought this was + + align:start position:0% +products and they they thought this was + + + align:start position:0% +products and they they thought this was +a disadvantage well + + align:start position:0% +a disadvantage well + + + align:start position:0% +a disadvantage well +for some purposes is actually an + + align:start position:0% +for some purposes is actually an + + + align:start position:0% +for some purposes is actually an +advantage then if we take the product of + + align:start position:0% +advantage then if we take the product of + + + align:start position:0% +advantage then if we take the product of +r and s and take the dot with t + + align:start position:0% +r and s and take the dot with t + + + align:start position:0% +r and s and take the dot with t +uh we get the triple product rst and the + + align:start position:0% +uh we get the triple product rst and the + + + align:start position:0% +uh we get the triple product rst and the +triple products often pretty useful + + align:start position:0% +triple products often pretty useful + + + align:start position:0% +triple products often pretty useful +aside from computing volumes or + + align:start position:0% +aside from computing volumes or + + + align:start position:0% +aside from computing volumes or +something + + align:start position:0% +something + + + align:start position:0% +something +and again this is very simple to prove + + align:start position:0% +and again this is very simple to prove + + + align:start position:0% +and again this is very simple to prove +you know once you have a zero scalar + + align:start position:0% +you know once you have a zero scalar + + + align:start position:0% +you know once you have a zero scalar +part + + align:start position:0% +part + + + align:start position:0% +part +then all you're going to get is the + + align:start position:0% +then all you're going to get is the + + + align:start position:0% +then all you're going to get is the +vector part of t dotted with + + align:start position:0% +vector part of t dotted with + + + align:start position:0% +vector part of t dotted with +this thing r cross s + + align:start position:0% +this thing r cross s + + + align:start position:0% +this thing r cross s +and of course that's just you know r + + align:start position:0% +and of course that's just you know r + + + align:start position:0% +and of course that's just you know r +cross s dot t that's the triple product + + align:start position:0% +cross s dot t that's the triple product + + + align:start position:0% +cross s dot t that's the triple product +rst + + align:start position:0% +rst + + + align:start position:0% +rst +and so on + + align:start position:0% +and so on + + + align:start position:0% +and so on +so + + align:start position:0% +so + + + align:start position:0% +so +that's how we represent + + align:start position:0% + + + + align:start position:0% + +vectors + + align:start position:0% +vectors + + + align:start position:0% +vectors +okay scalars yeah we can do that + + align:start position:0% +okay scalars yeah we can do that + + + align:start position:0% +okay scalars yeah we can do that +finally we get to rotation so how do we + + align:start position:0% +finally we get to rotation so how do we + + + align:start position:0% +finally we get to rotation so how do we +do rotation well it turns out that a + + align:start position:0% +do rotation well it turns out that a + + + align:start position:0% +do rotation well it turns out that a +simple product of a quaternion with + + align:start position:0% +simple product of a quaternion with + + + align:start position:0% +simple product of a quaternion with +another quaternion won't do it because + + align:start position:0% +another quaternion won't do it because + + + align:start position:0% +another quaternion won't do it because +it takes us out of 3d into 4d + + align:start position:0% +it takes us out of 3d into 4d + + + align:start position:0% +it takes us out of 3d into 4d +we need an operation that takes us back + + align:start position:0% +we need an operation that takes us back + + + align:start position:0% +we need an operation that takes us back +into 3d + + align:start position:0% +into 3d + + + align:start position:0% +into 3d +and so + + align:start position:0% +and so + + + align:start position:0% +and so +this is a little bit like + + align:start position:0% +this is a little bit like + + + align:start position:0% +this is a little bit like +you can do rotation in the plane by + + align:start position:0% +you can do rotation in the plane by + + + align:start position:0% +you can do rotation in the plane by +doing some operation that takes you out + + align:start position:0% +doing some operation that takes you out + + + align:start position:0% +doing some operation that takes you out +into three space but then you have to + + align:start position:0% +into three space but then you have to + + + align:start position:0% +into three space but then you have to +have another part of the operation that + + align:start position:0% +have another part of the operation that + + + align:start position:0% +have another part of the operation that +takes you back into the plane now in a + + align:start position:0% +takes you back into the plane now in a + + + align:start position:0% +takes you back into the plane now in a +rotated form so this is like that if we + + align:start position:0% +rotated form so this is like that if we + + + align:start position:0% +rotated form so this is like that if we +multiply two quaternions we're basically + + align:start position:0% +multiply two quaternions we're basically + + + align:start position:0% +multiply two quaternions we're basically +doing an operation of rotation in four + + align:start position:0% +doing an operation of rotation in four + + + align:start position:0% +doing an operation of rotation in four +space + + align:start position:0% +space + + + align:start position:0% +space +and now we need to find a + + align:start position:0% +and now we need to find a + + + align:start position:0% +and now we need to find a +operation that + + align:start position:0% +operation that + + + align:start position:0% +operation that +doesn't undo that but takes us back into + + align:start position:0% +doesn't undo that but takes us back into + + + align:start position:0% +doesn't undo that but takes us back into +free space and this is + + align:start position:0% +free space and this is + + + align:start position:0% +free space and this is +exactly what what happens here so we + + align:start position:0% +exactly what what happens here so we + + + align:start position:0% +exactly what what happens here so we +take our vector r turn it into a + + align:start position:0% +take our vector r turn it into a + + + align:start position:0% +take our vector r turn it into a +quaternion with zero scalar part then we + + align:start position:0% +quaternion with zero scalar part then we + + + align:start position:0% +quaternion with zero scalar part then we +pre-multiply by q and post-multiply by q + + align:start position:0% +pre-multiply by q and post-multiply by q + + + align:start position:0% +pre-multiply by q and post-multiply by q +conjugate and magically we're back in + + align:start position:0% +conjugate and magically we're back in + + + align:start position:0% +conjugate and magically we're back in +the in the real world so that this + + align:start position:0% +the in the real world so that this + + + align:start position:0% +the in the real world so that this +quaternion r prime has a zero scalar + + align:start position:0% +quaternion r prime has a zero scalar + + + align:start position:0% +quaternion r prime has a zero scalar +part and so this is how we're going to + + align:start position:0% +part and so this is how we're going to + + + align:start position:0% +part and so this is how we're going to +do rotation + + align:start position:0% +do rotation + + + align:start position:0% +do rotation +now there are many different ways of + + align:start position:0% +now there are many different ways of + + + align:start position:0% +now there are many different ways of +analyzing this one is to use that trick + + align:start position:0% +analyzing this one is to use that trick + + + align:start position:0% +analyzing this one is to use that trick +we had of + + align:start position:0% +we had of + + + align:start position:0% +we had of +representing quaternion multiplication + + align:start position:0% +representing quaternion multiplication + + + align:start position:0% +representing quaternion multiplication +as multiplication of four by four + + align:start position:0% +as multiplication of four by four + + + align:start position:0% +as multiplication of four by four +matrices and a four vector right so we + + align:start position:0% +matrices and a four vector right so we + + + align:start position:0% +matrices and a four vector right so we +take these first two + + align:start position:0% +take these first two + + + align:start position:0% +take these first two +and turn them into that + + align:start position:0% +and turn them into that + + + align:start position:0% +and turn them into that +and then we take the second uh + + align:start position:0% +and then we take the second uh + + + align:start position:0% +and then we take the second uh +multiplication and this time we turn the + + align:start position:0% +multiplication and this time we turn the + + + align:start position:0% +multiplication and this time we turn the +q + + align:start position:0% +q + + + align:start position:0% +q +conjugate into a matrix this matrix over + + align:start position:0% +conjugate into a matrix this matrix over + + + align:start position:0% +conjugate into a matrix this matrix over +here + + align:start position:0% +here + + + align:start position:0% +here +okay so + + align:start position:0% +okay so + + + align:start position:0% +okay so +this operation is actually equivalent to + + align:start position:0% +this operation is actually equivalent to + + + align:start position:0% +this operation is actually equivalent to +that operation and what is this this is + + align:start position:0% +that operation and what is this this is + + + align:start position:0% +that operation and what is this this is +a four by four matrix is a product of + + align:start position:0% +a four by four matrix is a product of + + + align:start position:0% +a four by four matrix is a product of +two four by four matrices and if you + + align:start position:0% +two four by four matrices and if you + + + align:start position:0% +two four by four matrices and if you +multiply them out you get this + + align:start position:0% +multiply them out you get this + + + align:start position:0% +multiply them out you get this +and this uh the most interesting + + align:start position:0% +and this uh the most interesting + + + align:start position:0% +and this uh the most interesting +property of this is that the first row + + align:start position:0% +property of this is that the first row + + + align:start position:0% +property of this is that the first row +and the first column are mostly zeros + + align:start position:0% +and the first column are mostly zeros + + + align:start position:0% +and the first column are mostly zeros +and the result is that if you have a + + align:start position:0% +and the result is that if you have a + + + align:start position:0% +and the result is that if you have a +vector in 3d + + align:start position:0% +vector in 3d + + + align:start position:0% +vector in 3d +which has a zero part scalar part and + + align:start position:0% +which has a zero part scalar part and + + + align:start position:0% +which has a zero part scalar part and +multiplied by this + + align:start position:0% +multiplied by this + + + align:start position:0% +multiplied by this +there'll be no zero scalar part right + + align:start position:0% +there'll be no zero scalar part right + + + align:start position:0% +there'll be no zero scalar part right +because you're multiplying this by zero + + align:start position:0% +because you're multiplying this by zero + + + align:start position:0% +because you're multiplying this by zero +and then you're adding all of these + + align:start position:0% +and then you're adding all of these + + + align:start position:0% +and then you're adding all of these +zeros multiplied by whatever and you get + + align:start position:0% +zeros multiplied by whatever and you get + + + align:start position:0% +zeros multiplied by whatever and you get +zero so so uh all this is proved so far + + align:start position:0% +zero so so uh all this is proved so far + + + align:start position:0% +zero so so uh all this is proved so far +is that this operation will in fact get + + align:start position:0% +is that this operation will in fact get + + + align:start position:0% +is that this operation will in fact get +you back into 3d so + + align:start position:0% + + + + align:start position:0% + +and this + + align:start position:0% +and this + + + align:start position:0% +and this +by the way this sub matrix is also and + + align:start position:0% +by the way this sub matrix is also and + + + align:start position:0% +by the way this sub matrix is also and +this actually is our three by three + + align:start position:0% +this actually is our three by three + + + align:start position:0% +this actually is our three by three +orthonormal rotational matrix + + align:start position:0% + + + + align:start position:0% + +okay so that's the + + align:start position:0% +okay so that's the + + + align:start position:0% +okay so that's the +equation we're going to use for rotation + + align:start position:0% +equation we're going to use for rotation + + + align:start position:0% +equation we're going to use for rotation +and this is the scalar part we can + + align:start position:0% +and this is the scalar part we can + + + align:start position:0% +and this is the scalar part we can +compute the scalar part and if the + + align:start position:0% +compute the scalar part and if the + + + align:start position:0% +compute the scalar part and if the +scalar part of the original vector is 0 + + align:start position:0% +scalar part of the original vector is 0 + + + align:start position:0% +scalar part of the original vector is 0 +we get 0 for the scalar part of the new + + align:start position:0% +we get 0 for the scalar part of the new + + + align:start position:0% +we get 0 for the scalar part of the new +vector the vector part can be computed + + align:start position:0% +vector the vector part can be computed + + + align:start position:0% +vector the vector part can be computed +this way so if you don't want to you + + align:start position:0% +this way so if you don't want to you + + + align:start position:0% +this way so if you don't want to you +know jump into the ocean of quaternions + + align:start position:0% +know jump into the ocean of quaternions + + + align:start position:0% +know jump into the ocean of quaternions +you can do everything using scalars and + + align:start position:0% +you can do everything using scalars and + + + align:start position:0% +you can do everything using scalars and +vectors here's the formula + + align:start position:0% +vectors here's the formula + + + align:start position:0% +vectors here's the formula +right so + + align:start position:0% +right so + + + align:start position:0% +right so +uh + + align:start position:0% +uh + + + align:start position:0% +uh +you know just dot products and cross + + align:start position:0% +you know just dot products and cross + + + align:start position:0% +you know just dot products and cross +products very easy + + align:start position:0% +products very easy + + + align:start position:0% +products very easy +when we uh + + align:start position:0% +when we uh + + + align:start position:0% +when we uh +use this operation + + align:start position:0% +use this operation + + + align:start position:0% +use this operation +we can easily well with a bit of algebra + + align:start position:0% +we can easily well with a bit of algebra + + + align:start position:0% +we can easily well with a bit of algebra +we can prove that it preserves dot + + align:start position:0% +we can prove that it preserves dot + + + align:start position:0% +we can prove that it preserves dot +products right you just take this + + align:start position:0% +products right you just take this + + + align:start position:0% +products right you just take this +formula apply it to r and then apply it + + align:start position:0% +formula apply it to r and then apply it + + + align:start position:0% +formula apply it to r and then apply it +to s take the dot product and you get r + + align:start position:0% +to s take the dot product and you get r + + + align:start position:0% +to s take the dot product and you get r +dot s + + align:start position:0% +dot s + + + align:start position:0% +dot s +and so it preserves dot product + + align:start position:0% +and so it preserves dot product + + + align:start position:0% +and so it preserves dot product +uh similarly it preserves triple + + align:start position:0% +uh similarly it preserves triple + + + align:start position:0% +uh similarly it preserves triple +products remember we had this special + + align:start position:0% +products remember we had this special + + + align:start position:0% +products remember we had this special +form that this multiplication gave us a + + align:start position:0% +form that this multiplication gave us a + + + align:start position:0% +form that this multiplication gave us a +triple product of the vector uh the + + align:start position:0% +triple product of the vector uh the + + + align:start position:0% +triple product of the vector uh the +underlying vectors + + align:start position:0% +underlying vectors + + + align:start position:0% +underlying vectors +well it preserves triple products so so + + align:start position:0% +well it preserves triple products so so + + + align:start position:0% +well it preserves triple products so so +that's it it's a + + align:start position:0% +that's it it's a + + + align:start position:0% +that's it it's a +rotation right it preserves dot products + + align:start position:0% +rotation right it preserves dot products + + + align:start position:0% +rotation right it preserves dot products +it preserves triple products + + align:start position:0% +it preserves triple products + + + align:start position:0% +it preserves triple products +so that's good + + align:start position:0% +so that's good + + + align:start position:0% +so that's good +we don't know yet what rotation but but + + align:start position:0% +we don't know yet what rotation but but + + + align:start position:0% +we don't know yet what rotation but but +we know it has to be a rotation because + + align:start position:0% +we know it has to be a rotation because + + + align:start position:0% +we know it has to be a rotation because +it preserves length and angles and it + + align:start position:0% +it preserves length and angles and it + + + align:start position:0% +it preserves length and angles and it +preserves handedness + + align:start position:0% +preserves handedness + + + align:start position:0% +preserves handedness +and then the other thing we were talking + + align:start position:0% +and then the other thing we were talking + + + align:start position:0% +and then the other thing we were talking +about was not just rotating a vector but + + align:start position:0% +about was not just rotating a vector but + + + align:start position:0% +about was not just rotating a vector but +composing rotations we wanted that to be + + align:start position:0% +composing rotations we wanted that to be + + + align:start position:0% +composing rotations we wanted that to be +easy well uh so suppose we first rotate + + align:start position:0% +easy well uh so suppose we first rotate + + + align:start position:0% +easy well uh so suppose we first rotate +uh we take our vector r we rotate it + + align:start position:0% +uh we take our vector r we rotate it + + + align:start position:0% +uh we take our vector r we rotate it +using q + + align:start position:0% +using q + + + align:start position:0% +using q +and then we take the result and we + + align:start position:0% +and then we take the result and we + + + align:start position:0% +and then we take the result and we +rotate it using p + + align:start position:0% +rotate it using p + + + align:start position:0% +rotate it using p +so we we write this and because these + + align:start position:0% +so we we write this and because these + + + align:start position:0% +so we we write this and because these +operations are associative i can rewrite + + align:start position:0% +operations are associative i can rewrite + + + align:start position:0% +operations are associative i can rewrite +it this way + + align:start position:0% +it this way + + + align:start position:0% +it this way +and that tells you oh + + align:start position:0% +and that tells you oh + + + align:start position:0% +and that tells you oh +composition of rotation is just + + align:start position:0% +composition of rotation is just + + + align:start position:0% +composition of rotation is just +multiplication of quaternions very easy + + align:start position:0% +multiplication of quaternions very easy + + + align:start position:0% +multiplication of quaternions very easy +and actually computationally efficient + + align:start position:0% +and actually computationally efficient + + + align:start position:0% +and actually computationally efficient +as well + + align:start position:0% +as well + + + align:start position:0% +as well +which is very different from axes in + + align:start position:0% +which is very different from axes in + + + align:start position:0% +which is very different from axes in +angle notation or euler angles + + align:start position:0% +angle notation or euler angles + + + align:start position:0% +angle notation or euler angles +where it's very hard to compose + + align:start position:0% +where it's very hard to compose + + + align:start position:0% +where it's very hard to compose +rotations + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% + + + + align:start position:0% + +then we need to figure out what rotation + + align:start position:0% +then we need to figure out what rotation + + + align:start position:0% +then we need to figure out what rotation +is it + + align:start position:0% +is it + + + align:start position:0% +is it +or if we have specified rotation in some + + align:start position:0% +or if we have specified rotation in some + + + align:start position:0% +or if we have specified rotation in some +other form how do we turn it into + + align:start position:0% +other form how do we turn it into + + + align:start position:0% +other form how do we turn it into +quaternion + + align:start position:0% +quaternion + + + align:start position:0% +quaternion +well + + align:start position:0% +well + + + align:start position:0% +well +this is the formula we just + + align:start position:0% +this is the formula we just + + + align:start position:0% +this is the formula we just +sort of derived on the previous page + + align:start position:0% +sort of derived on the previous page + + + align:start position:0% +sort of derived on the previous page +and here's rodriguez's formula remember + + align:start position:0% +and here's rodriguez's formula remember + + + align:start position:0% +and here's rodriguez's formula remember +from + + align:start position:0% +from + + + align:start position:0% +from +a while back and then if we identify + + align:start position:0% +a while back and then if we identify + + + align:start position:0% +a while back and then if we identify +corresponding pairs first thing you + + align:start position:0% +corresponding pairs first thing you + + + align:start position:0% +corresponding pairs first thing you +notice is that q the vector part is + + align:start position:0% +notice is that q the vector part is + + + align:start position:0% +notice is that q the vector part is +parallel to omega so the vector part of + + align:start position:0% +parallel to omega so the vector part of + + + align:start position:0% +parallel to omega so the vector part of +the quaternion is in the direction of + + align:start position:0% +the quaternion is in the direction of + + + align:start position:0% +the quaternion is in the direction of +the axis + + align:start position:0% +the axis + + + align:start position:0% +the axis +sort of makes sense + + align:start position:0% + + + + align:start position:0% + +and we can actually prove that easily + + align:start position:0% +and we can actually prove that easily + + + align:start position:0% +and we can actually prove that easily +if you + + align:start position:0% +if you + + + align:start position:0% +if you +um + + align:start position:0% +um + + + align:start position:0% +um +if you plug um + + align:start position:0% +if you plug um + + + align:start position:0% +if you plug um +if you plug q in here for r + + align:start position:0% +if you plug q in here for r + + + align:start position:0% +if you plug q in here for r +what happens well this part drops out + + align:start position:0% +what happens well this part drops out + + + align:start position:0% +what happens well this part drops out +because + + align:start position:0% +because + + + align:start position:0% +because +you know q cross q is 0. + + align:start position:0% +you know q cross q is 0. + + + align:start position:0% +you know q cross q is 0. +and then + + align:start position:0% +and then + + + align:start position:0% +and then +this becomes q dot q times q + + align:start position:0% +this becomes q dot q times q + + + align:start position:0% +this becomes q dot q times q +and this becomes something times q + + align:start position:0% +and this becomes something times q + + + align:start position:0% +and this becomes something times q +so what + + align:start position:0% +so what + + + align:start position:0% +so what +the whole thing + + align:start position:0% +the whole thing + + + align:start position:0% +the whole thing +both of these are vectors in the q + + align:start position:0% +both of these are vectors in the q + + + align:start position:0% +both of these are vectors in the q +direction so r prime is going to be in + + align:start position:0% +direction so r prime is going to be in + + + align:start position:0% +direction so r prime is going to be in +the q direction so uh very easy to show + + align:start position:0% +the q direction so uh very easy to show + + + align:start position:0% +the q direction so uh very easy to show +that q becomes q + + align:start position:0% +that q becomes q + + + align:start position:0% +that q becomes q +you know and that's + + align:start position:0% +you know and that's + + + align:start position:0% +you know and that's +euler's + + align:start position:0% +euler's + + + align:start position:0% +euler's +axis theorem + + align:start position:0% +axis theorem + + + align:start position:0% +axis theorem +so it's very easy to see that the vector + + align:start position:0% +so it's very easy to see that the vector + + + align:start position:0% +so it's very easy to see that the vector +part is parallel to the + + align:start position:0% +part is parallel to the + + + align:start position:0% +part is parallel to the +axis of rotation we don't know yet how + + align:start position:0% +axis of rotation we don't know yet how + + + align:start position:0% +axis of rotation we don't know yet how +long it's supposed to be + + align:start position:0% +long it's supposed to be + + + align:start position:0% +long it's supposed to be +and we don't know what the angle is + + align:start position:0% +and we don't know what the angle is + + + align:start position:0% +and we don't know what the angle is +but anyway uh leave out some of this the + + align:start position:0% +but anyway uh leave out some of this the + + + align:start position:0% +but anyway uh leave out some of this the +conclusion is this is our representation + + align:start position:0% +conclusion is this is our representation + + + align:start position:0% +conclusion is this is our representation +a conversion so if we know + + align:start position:0% +a conversion so if we know + + + align:start position:0% +a conversion so if we know +axis and angle we can compute the uh + + align:start position:0% +axis and angle we can compute the uh + + + align:start position:0% +axis and angle we can compute the uh +quaternion + + align:start position:0% +quaternion + + + align:start position:0% +quaternion +so that's one of the conversions between + + align:start position:0% +so that's one of the conversions between + + + align:start position:0% +so that's one of the conversions between +the you know we have eight different + + align:start position:0% +the you know we have eight different + + + align:start position:0% +the you know we have eight different +ways of representing it so there are + + align:start position:0% +ways of representing it so there are + + + align:start position:0% +ways of representing it so there are +eight times seven + + align:start position:0% +eight times seven + + + align:start position:0% +eight times seven +56 different conversions we could + + align:start position:0% +56 different conversions we could + + + align:start position:0% +56 different conversions we could +possibly do but we're not going to do + + align:start position:0% +possibly do but we're not going to do + + + align:start position:0% +possibly do but we're not going to do +them + + align:start position:0% +them + + + align:start position:0% +them +so this is one the other one we saw + + align:start position:0% +so this is one the other one we saw + + + align:start position:0% +so this is one the other one we saw +earlier + + align:start position:0% +earlier + + + align:start position:0% +earlier +where we can we produce the orthonormal + + align:start position:0% +where we can we produce the orthonormal + + + align:start position:0% +where we can we produce the orthonormal +matrix that's another important one + + align:start position:0% +matrix that's another important one + + + align:start position:0% +matrix that's another important one +because we use orthonormal matrices all + + align:start position:0% +because we use orthonormal matrices all + + + align:start position:0% +because we use orthonormal matrices all +the time we need to be able to go back + + align:start position:0% +the time we need to be able to go back + + + align:start position:0% +the time we need to be able to go back +and forth between axis and angle which + + align:start position:0% +and forth between axis and angle which + + + align:start position:0% +and forth between axis and angle which +is this formula + + align:start position:0% +is this formula + + + align:start position:0% +is this formula +and between orthogonal matrix and that + + align:start position:0% +and between orthogonal matrix and that + + + align:start position:0% +and between orthogonal matrix and that +was that previous formula + + align:start position:0% +was that previous formula + + + align:start position:0% +was that previous formula +uh there so there are two things about + + align:start position:0% +uh there so there are two things about + + + align:start position:0% +uh there so there are two things about +this one of them this is a unit + + align:start position:0% +this one of them this is a unit + + + align:start position:0% +this one of them this is a unit +quaternion you easily prove you you know + + align:start position:0% +quaternion you easily prove you you know + + + align:start position:0% +quaternion you easily prove you you know +take its dot product with itself and you + + align:start position:0% +take its dot product with itself and you + + + align:start position:0% +take its dot product with itself and you +get cos squared theta over two plus sine + + align:start position:0% +get cos squared theta over two plus sine + + + align:start position:0% +get cos squared theta over two plus sine +squared theta over two so + + align:start position:0% +squared theta over two so + + + align:start position:0% +squared theta over two so +so that's one thing so we're not talking + + align:start position:0% +so that's one thing so we're not talking + + + align:start position:0% +so that's one thing so we're not talking +about arbitrary quaternions just unit + + align:start position:0% +about arbitrary quaternions just unit + + + align:start position:0% +about arbitrary quaternions just unit +quaternions and then the other thing + + align:start position:0% +quaternions and then the other thing + + + align:start position:0% +quaternions and then the other thing +that's a little bit uh annoying is that + + align:start position:0% +that's a little bit uh annoying is that + + + align:start position:0% +that's a little bit uh annoying is that +minus q is the same rotation as plus q + + align:start position:0% +minus q is the same rotation as plus q + + + align:start position:0% +minus q is the same rotation as plus q +y well imagine you plug minus q into + + align:start position:0% +y well imagine you plug minus q into + + + align:start position:0% +y well imagine you plug minus q into +this formula the minuses just multi + + align:start position:0% +this formula the minuses just multi + + + align:start position:0% +this formula the minuses just multi +disappear + + align:start position:0% +disappear + + + align:start position:0% +disappear +so + + align:start position:0% +so + + + align:start position:0% +so +what does this mean it means that if we + + align:start position:0% +what does this mean it means that if we + + + align:start position:0% +what does this mean it means that if we +think of the sphere + + align:start position:0% +think of the sphere + + + align:start position:0% +think of the sphere +as representing the space of rotation + + align:start position:0% +as representing the space of rotation + + + align:start position:0% +as representing the space of rotation +opposite points are actually the same + + align:start position:0% +opposite points are actually the same + + + align:start position:0% +opposite points are actually the same +rotation + + align:start position:0% +rotation + + + align:start position:0% +rotation +so it's you know + + align:start position:0% +so it's you know + + + align:start position:0% +so it's you know +it's very nice to think of a sphere in + + align:start position:0% +it's very nice to think of a sphere in + + + align:start position:0% +it's very nice to think of a sphere in +four dimensions as the space of rotation + + align:start position:0% +four dimensions as the space of rotation + + + align:start position:0% +four dimensions as the space of rotation +and then we can produce ways of sampling + + align:start position:0% +and then we can produce ways of sampling + + + align:start position:0% +and then we can produce ways of sampling +that space and taking integrals and take + + align:start position:0% +that space and taking integrals and take + + + align:start position:0% +that space and taking integrals and take +computing averages and so on but you + + align:start position:0% +computing averages and so on but you + + + align:start position:0% +computing averages and so on but you +have to keep in mind that you really + + align:start position:0% +have to keep in mind that you really + + + align:start position:0% +have to keep in mind that you really +only want half the sphere because the + + align:start position:0% +only want half the sphere because the + + + align:start position:0% +only want half the sphere because the +opposite side the reflected side + + align:start position:0% +opposite side the reflected side + + + align:start position:0% +opposite side the reflected side +represents the same rotations + + align:start position:0% + + + + align:start position:0% + +and typical points are identified so we + + align:start position:0% +and typical points are identified so we + + + align:start position:0% +and typical points are identified so we +use we're going to use this in + + align:start position:0% +use we're going to use this in + + + align:start position:0% +use we're going to use this in +photogrammetry and uh in particular + + align:start position:0% +photogrammetry and uh in particular + + + align:start position:0% +photogrammetry and uh in particular +in absolute orientation + + align:start position:0% +in absolute orientation + + + align:start position:0% +in absolute orientation +we already talked about that and this is + + align:start position:0% +we already talked about that and this is + + + align:start position:0% +we already talked about that and this is +from last lecture so we got + + align:start position:0% +from last lecture so we got + + + align:start position:0% +from last lecture so we got +points in space + + align:start position:0% +points in space + + + align:start position:0% +points in space +identified measured in two coordinate + + align:start position:0% +identified measured in two coordinate + + + align:start position:0% +identified measured in two coordinate +systems we want to know the + + align:start position:0% +systems we want to know the + + + align:start position:0% +systems we want to know the +coordinate transformation between those + + align:start position:0% +coordinate transformation between those + + + align:start position:0% +coordinate transformation between those +two systems + + align:start position:0% +two systems + + + align:start position:0% +two systems +and it's dual to the other problem where + + align:start position:0% +and it's dual to the other problem where + + + align:start position:0% +and it's dual to the other problem where +we have the same coordinate system but + + align:start position:0% +we have the same coordinate system but + + + align:start position:0% +we have the same coordinate system but +we have two objects so we have one + + align:start position:0% +we have two objects so we have one + + + align:start position:0% +we have two objects so we have one +object moving + + align:start position:0% +object moving + + + align:start position:0% +object moving +and we modeled it this way where + + align:start position:0% +and we modeled it this way where + + + align:start position:0% +and we modeled it this way where +coordinates in the left system are + + align:start position:0% +coordinates in the left system are + + + align:start position:0% +coordinates in the left system are +rotated and translated to produce + + align:start position:0% +rotated and translated to produce + + + align:start position:0% +rotated and translated to produce +coordinates in the right coordinate + + align:start position:0% +coordinates in the right coordinate + + + align:start position:0% +coordinates in the right coordinate +system and we want the best fit rotation + + align:start position:0% +system and we want the best fit rotation + + + align:start position:0% +system and we want the best fit rotation +and translation meaning we want to + + align:start position:0% +and translation meaning we want to + + + align:start position:0% +and translation meaning we want to +minimize some error + + align:start position:0% +minimize some error + + + align:start position:0% +minimize some error +and what we're given are a bunch of + + align:start position:0% +and what we're given are a bunch of + + + align:start position:0% +and what we're given are a bunch of +corresponding points measured in the two + + align:start position:0% +corresponding points measured in the two + + + align:start position:0% +corresponding points measured in the two +coordinate system + + align:start position:0% +coordinate system + + + align:start position:0% +coordinate system +left left and right + + align:start position:0% +left left and right + + + align:start position:0% +left left and right +and then we talked about this mechanical + + align:start position:0% +and then we talked about this mechanical + + + align:start position:0% +and then we talked about this mechanical +this physical analog + + align:start position:0% +this physical analog + + + align:start position:0% +this physical analog +uh that we want a min we want to make + + align:start position:0% +uh that we want a min we want to make + + + align:start position:0% +uh that we want a min we want to make +these errors small and so one way to do + + align:start position:0% +these errors small and so one way to do + + + align:start position:0% +these errors small and so one way to do +it is to have these springs + + align:start position:0% +it is to have these springs + + + align:start position:0% +it is to have these springs +which have energy proportional to the + + align:start position:0% +which have energy proportional to the + + + align:start position:0% +which have energy proportional to the +distance squared + + align:start position:0% +distance squared + + + align:start position:0% +distance squared +and the energy total energy in those + + align:start position:0% +and the energy total energy in those + + + align:start position:0% +and the energy total energy in those +springs is the sum of squares of errors + + align:start position:0% +springs is the sum of squares of errors + + + align:start position:0% +springs is the sum of squares of errors +and the system wants to minimize that so + + align:start position:0% +and the system wants to minimize that so + + + align:start position:0% +and the system wants to minimize that so +that's the physical model + + align:start position:0% +that's the physical model + + + align:start position:0% +that's the physical model +of how it finds the rotation and + + align:start position:0% +of how it finds the rotation and + + + align:start position:0% +of how it finds the rotation and +transcend translation + + align:start position:0% +transcend translation + + + align:start position:0% +transcend translation +so then we + + align:start position:0% +so then we + + + align:start position:0% +so then we +we did this so + + align:start position:0% +we did this so + + + align:start position:0% +we did this so +this is the error term right because if + + align:start position:0% +this is the error term right because if + + + align:start position:0% +this is the error term right because if +i take the left coordinate and i rotate + + align:start position:0% +i take the left coordinate and i rotate + + + align:start position:0% +i take the left coordinate and i rotate +and translate it i i get this and that + + align:start position:0% +and translate it i i get this and that + + + align:start position:0% +and translate it i i get this and that +should be equal to the right coordinate + + align:start position:0% +should be equal to the right coordinate + + + align:start position:0% +should be equal to the right coordinate +when i subtract them i get the remaining + + align:start position:0% +when i subtract them i get the remaining + + + align:start position:0% +when i subtract them i get the remaining +error i square that i add all of those + + align:start position:0% +error i square that i add all of those + + + align:start position:0% +error i square that i add all of those +errors + + align:start position:0% +errors + + + align:start position:0% +errors +then first step let's find the + + align:start position:0% +then first step let's find the + + + align:start position:0% +then first step let's find the +translation and we did this last time + + align:start position:0% +translation and we did this last time + + + align:start position:0% +translation and we did this last time +one way to do it which is not the way we + + align:start position:0% +one way to do it which is not the way we + + + align:start position:0% +one way to do it which is not the way we +did it in class is just differentiate + + align:start position:0% +did it in class is just differentiate + + + align:start position:0% +did it in class is just differentiate +with respect to the translation r0 and + + align:start position:0% +with respect to the translation r0 and + + + align:start position:0% +with respect to the translation r0 and +this is uh + + align:start position:0% +this is uh + + + align:start position:0% +this is uh +you know this notation this is the norm + + align:start position:0% +you know this notation this is the norm + + + align:start position:0% +you know this notation this is the norm +which is really the dot product of this + + align:start position:0% +which is really the dot product of this + + + align:start position:0% +which is really the dot product of this +thing with itself if we differentiate it + + align:start position:0% +thing with itself if we differentiate it + + + align:start position:0% +thing with itself if we differentiate it +we get twice this + + align:start position:0% +we get twice this + + + align:start position:0% +we get twice this +and we set that equal to zero and then + + align:start position:0% +and we set that equal to zero and then + + + align:start position:0% +and we set that equal to zero and then +we can split so we have a sum of + + align:start position:0% +we can split so we have a sum of + + + align:start position:0% +we can split so we have a sum of +three terms we can split that into + + align:start position:0% +three terms we can split that into + + + align:start position:0% +three terms we can split that into +uh three sums right so for example of + + align:start position:0% +uh three sums right so for example of + + + align:start position:0% +uh three sums right so for example of +course we get rid of the two that's not + + align:start position:0% +course we get rid of the two that's not + + + align:start position:0% +course we get rid of the two that's not +very interesting + + align:start position:0% +very interesting + + + align:start position:0% +very interesting +and we get this and and final result was + + align:start position:0% +and we get this and and final result was + + + align:start position:0% +and we get this and and final result was +just that + + align:start position:0% +just that + + + align:start position:0% +just that +uh the translation is what takes the + + align:start position:0% +uh the translation is what takes the + + + align:start position:0% +uh the translation is what takes the +centroid in the left system + + align:start position:0% +centroid in the left system + + + align:start position:0% +centroid in the left system +after rotation + + align:start position:0% +after rotation + + + align:start position:0% +after rotation +into the centroid of the right system so + + align:start position:0% +into the centroid of the right system so + + + align:start position:0% +into the centroid of the right system so +so that's + + align:start position:0% + + + + align:start position:0% + +kind of intuitive and nice it says that + + align:start position:0% +kind of intuitive and nice it says that + + + align:start position:0% +kind of intuitive and nice it says that +you know whatever your transformation is + + align:start position:0% +you know whatever your transformation is + + + align:start position:0% +you know whatever your transformation is +it should map the centroid of this point + + align:start position:0% +it should map the centroid of this point + + + align:start position:0% +it should map the centroid of this point +cloud into the centroid of that point + + align:start position:0% +cloud into the centroid of that point + + + align:start position:0% +cloud into the centroid of that point +cloud and one of the nice features of it + + align:start position:0% +cloud and one of the nice features of it + + + align:start position:0% +cloud and one of the nice features of it +is that you don't even need + + align:start position:0% +is that you don't even need + + + align:start position:0% +is that you don't even need +correspondences + + align:start position:0% +correspondences + + + align:start position:0% +correspondences +you just compute the centroid of those + + align:start position:0% +you just compute the centroid of those + + + align:start position:0% +you just compute the centroid of those +clouds so for this part uh you don't + + align:start position:0% +clouds so for this part uh you don't + + + align:start position:0% +clouds so for this part uh you don't +need to know which point in that cloud + + align:start position:0% +need to know which point in that cloud + + + align:start position:0% +need to know which point in that cloud +corresponds to which point in the other + + align:start position:0% +corresponds to which point in the other + + + align:start position:0% +corresponds to which point in the other +cloud + + align:start position:0% +cloud + + + align:start position:0% +cloud +and of course right now we can't get the + + align:start position:0% +and of course right now we can't get the + + + align:start position:0% +and of course right now we can't get the +answer because we don't know r + + align:start position:0% +answer because we don't know r + + + align:start position:0% +answer because we don't know r +but this is the formula that we're going + + align:start position:0% +but this is the formula that we're going + + + align:start position:0% +but this is the formula that we're going +to come back to at the end to get the + + align:start position:0% +to come back to at the end to get the + + + align:start position:0% +to come back to at the end to get the +translation + + align:start position:0% +translation + + + align:start position:0% +translation +and so at that point we can + + align:start position:0% +and so at that point we can + + + align:start position:0% +and so at that point we can +at that point we can move the origin to + + align:start position:0% +at that point we can move the origin to + + + align:start position:0% +at that point we can move the origin to +the centroid + + align:start position:0% +the centroid + + + align:start position:0% +the centroid +and + + align:start position:0% +and + + + align:start position:0% +and +add a dash to the r's indicating they're + + align:start position:0% +add a dash to the r's indicating they're + + + align:start position:0% +add a dash to the r's indicating they're +now measured with respect to the + + align:start position:0% +now measured with respect to the + + + align:start position:0% +now measured with respect to the +centroid so + + align:start position:0% +centroid so + + + align:start position:0% +centroid so +when we do that the formula simplifies + + align:start position:0% +when we do that the formula simplifies + + + align:start position:0% +when we do that the formula simplifies +this now that we're minimizing this + + align:start position:0% +this now that we're minimizing this + + + align:start position:0% +this now that we're minimizing this +expression + + align:start position:0% +expression + + + align:start position:0% +expression +where these + + align:start position:0% +where these + + + align:start position:0% +where these +r prime and r r prime and r l prime are + + align:start position:0% +r prime and r r prime and r l prime are + + + align:start position:0% +r prime and r r prime and r l prime are +defined in terms of uh coordinates with + + align:start position:0% +defined in terms of uh coordinates with + + + align:start position:0% +defined in terms of uh coordinates with +respect to the center we subtract out + + align:start position:0% +respect to the center we subtract out + + + align:start position:0% +respect to the center we subtract out +the centroid subtract out the centroid + + align:start position:0% +the centroid subtract out the centroid + + + align:start position:0% +the centroid subtract out the centroid +there + + align:start position:0% +there + + + align:start position:0% +there +and okay then we take this and we + + align:start position:0% +and okay then we take this and we + + + align:start position:0% +and okay then we take this and we +multiply this out again the norm squared + + align:start position:0% +multiply this out again the norm squared + + + align:start position:0% +multiply this out again the norm squared +is just the dot product of this thing + + align:start position:0% +is just the dot product of this thing + + + align:start position:0% +is just the dot product of this thing +with itself so think of it written out + + align:start position:0% +with itself so think of it written out + + + align:start position:0% +with itself so think of it written out +that way then when you multiply out you + + align:start position:0% +that way then when you multiply out you + + + align:start position:0% +that way then when you multiply out you +get four terms you gather them up and + + align:start position:0% +get four terms you gather them up and + + + align:start position:0% +get four terms you gather them up and +you you get this + + align:start position:0% +you you get this + + + align:start position:0% +you you get this +and here we use one little trick which + + align:start position:0% +and here we use one little trick which + + + align:start position:0% +and here we use one little trick which +is that we noted that the length of a + + align:start position:0% +is that we noted that the length of a + + + align:start position:0% +is that we noted that the length of a +vector is not changed by rotation so + + align:start position:0% +vector is not changed by rotation so + + + align:start position:0% +vector is not changed by rotation so +over here we we really get r + + align:start position:0% +over here we we really get r + + + align:start position:0% +over here we we really get r +times + + align:start position:0% +times + + + align:start position:0% +times +the left vector squared + + align:start position:0% +the left vector squared + + + align:start position:0% +the left vector squared +but we know that after rotation it's the + + align:start position:0% +but we know that after rotation it's the + + + align:start position:0% +but we know that after rotation it's the +same length so we just + + align:start position:0% +same length so we just + + + align:start position:0% +same length so we just +replace it + + align:start position:0% +replace it + + + align:start position:0% +replace it +okay and at that point these two things + + align:start position:0% +okay and at that point these two things + + + align:start position:0% +okay and at that point these two things +are fixed they're given by the data + + align:start position:0% +are fixed they're given by the data + + + align:start position:0% +are fixed they're given by the data +they're not going to depend on the + + align:start position:0% +they're not going to depend on the + + + align:start position:0% +they're not going to depend on the +rotation you pick so forget about them + + align:start position:0% +rotation you pick so forget about them + + + align:start position:0% +rotation you pick so forget about them +we need to focus on this middle term + + align:start position:0% +we need to focus on this middle term + + + align:start position:0% +we need to focus on this middle term +it's the only one we have control over + + align:start position:0% +it's the only one we have control over + + + align:start position:0% +it's the only one we have control over +we can change r + + align:start position:0% +we can change r + + + align:start position:0% +we can change r +but it has a minus sign so we're trying + + align:start position:0% +but it has a minus sign so we're trying + + + align:start position:0% +but it has a minus sign so we're trying +to minimize something so that means we + + align:start position:0% +to minimize something so that means we + + + align:start position:0% +to minimize something so that means we +want to maximize uh this term + + align:start position:0% +want to maximize uh this term + + + align:start position:0% +want to maximize uh this term +and that that's where we got to last + + align:start position:0% +and that that's where we got to last + + + align:start position:0% +and that that's where we got to last +time + + align:start position:0% +time + + + align:start position:0% +time +and now i was explaining it in terms of + + align:start position:0% +and now i was explaining it in terms of + + + align:start position:0% +and now i was explaining it in terms of +uh see the sea urchin analogy where + + align:start position:0% +uh see the sea urchin analogy where + + + align:start position:0% +uh see the sea urchin analogy where +we've got these spines and we're trying + + align:start position:0% +we've got these spines and we're trying + + + align:start position:0% +we've got these spines and we're trying +to get them to + + align:start position:0% +to get them to + + + align:start position:0% +to get them to +um be as lined up as close as possible + + align:start position:0% +um be as lined up as close as possible + + + align:start position:0% +um be as lined up as close as possible +so that their dot product is as large as + + align:start position:0% +so that their dot product is as large as + + + align:start position:0% +so that their dot product is as large as +possible the dot product of + + align:start position:0% +possible the dot product of + + + align:start position:0% +possible the dot product of +corresponding point now we need + + align:start position:0% +corresponding point now we need + + + align:start position:0% +corresponding point now we need +correspondences + + align:start position:0% +correspondences + + + align:start position:0% +correspondences +and + + align:start position:0% +and + + + align:start position:0% +and +this is a classic problem in spacecraft + + align:start position:0% +this is a classic problem in spacecraft + + + align:start position:0% +this is a classic problem in spacecraft +attitude control + + align:start position:0% +attitude control + + + align:start position:0% +attitude control +you have the direction to + + align:start position:0% +you have the direction to + + + align:start position:0% +you have the direction to +stars in your cameras + + align:start position:0% +stars in your cameras + + + align:start position:0% +stars in your cameras +and you're trying to + + align:start position:0% +and you're trying to + + + align:start position:0% +and you're trying to +line them up with the catalog directions + + align:start position:0% +line them up with the catalog directions + + + align:start position:0% +line them up with the catalog directions +and of course you want to make the + + align:start position:0% +and of course you want to make the + + + align:start position:0% +and of course you want to make the +and it's a good analogy because in this + + align:start position:0% +and it's a good analogy because in this + + + align:start position:0% +and it's a good analogy because in this +case we don't care about the length we + + align:start position:0% +case we don't care about the length we + + + align:start position:0% +case we don't care about the length we +don't have the length we don't know how + + align:start position:0% +don't have the length we don't know how + + + align:start position:0% +don't have the length we don't know how +we from the camera we have no idea how + + align:start position:0% +we from the camera we have no idea how + + + align:start position:0% +we from the camera we have no idea how +far away the stars are and we don't care + + align:start position:0% +far away the stars are and we don't care + + + align:start position:0% +far away the stars are and we don't care +and if we move sideways actually that + + align:start position:0% +and if we move sideways actually that + + + align:start position:0% +and if we move sideways actually that +direction doesn't change because in + + align:start position:0% +direction doesn't change because in + + + align:start position:0% +direction doesn't change because in +comparison to the distance to the stars + + align:start position:0% +comparison to the distance to the stars + + + align:start position:0% +comparison to the distance to the stars +our own motion is microscopic + + align:start position:0% +our own motion is microscopic + + + align:start position:0% +our own motion is microscopic +so uh this would be the thing you want + + align:start position:0% +so uh this would be the thing you want + + + align:start position:0% +so uh this would be the thing you want +to maximize in in that case + + align:start position:0% +to maximize in in that case + + + align:start position:0% +to maximize in in that case +but how do you do it well you know + + align:start position:0% +but how do you do it well you know + + + align:start position:0% +but how do you do it well you know +we're sort of tuned to using calculus to + + align:start position:0% +we're sort of tuned to using calculus to + + + align:start position:0% +we're sort of tuned to using calculus to +solve all these problems just + + align:start position:0% +solve all these problems just + + + align:start position:0% +solve all these problems just +differentiate with respect to the + + align:start position:0% +differentiate with respect to the + + + align:start position:0% +differentiate with respect to the +unknown + + align:start position:0% +unknown + + + align:start position:0% +unknown +transformation but you know what does it + + align:start position:0% +transformation but you know what does it + + + align:start position:0% +transformation but you know what does it +mean to differentiate with respect to r + + align:start position:0% +mean to differentiate with respect to r + + + align:start position:0% +mean to differentiate with respect to r +now i'm sort of making fun of it but you + + align:start position:0% +now i'm sort of making fun of it but you + + + align:start position:0% +now i'm sort of making fun of it but you +can actually pursue this further + + align:start position:0% +can actually pursue this further + + + align:start position:0% +can actually pursue this further +what you need to do is not just + + align:start position:0% +what you need to do is not just + + + align:start position:0% +what you need to do is not just +differentiate with respect to r but + + align:start position:0% +differentiate with respect to r but + + + align:start position:0% +differentiate with respect to r but +impose all of those constraints that i + + align:start position:0% +impose all of those constraints that i + + + align:start position:0% +impose all of those constraints that i +talked about and you can do that it just + + align:start position:0% +talked about and you can do that it just + + + align:start position:0% +talked about and you can do that it just +gets messy you know you have to impose + + align:start position:0% +gets messy you know you have to impose + + + align:start position:0% +gets messy you know you have to impose +that r transpose r is the identity and + + align:start position:0% +that r transpose r is the identity and + + + align:start position:0% +that r transpose r is the identity and +you have the the determinant of r is + + align:start position:0% +you have the the determinant of r is + + + align:start position:0% +you have the the determinant of r is +plus one that's the hard one + + align:start position:0% + + + + align:start position:0% + +okay so let's not do it that way + + align:start position:0% +okay so let's not do it that way + + + align:start position:0% +okay so let's not do it that way +let's use our newfangled + + align:start position:0% +let's use our newfangled + + + align:start position:0% +let's use our newfangled +quaternion notation so here we have a + + align:start position:0% +quaternion notation so here we have a + + + align:start position:0% +quaternion notation so here we have a +dot product of two vectors and we can + + align:start position:0% +dot product of two vectors and we can + + + align:start position:0% +dot product of two vectors and we can +express that here as the dot product of + + align:start position:0% +express that here as the dot product of + + + align:start position:0% +express that here as the dot product of +two + + align:start position:0% +two + + + align:start position:0% +two +quaternions with zero scalar part + + align:start position:0% +quaternions with zero scalar part + + + align:start position:0% +quaternions with zero scalar part +right so we we map this + + align:start position:0% +right so we we map this + + + align:start position:0% +right so we we map this +r + + align:start position:0% +r + + + align:start position:0% +r +l i prime + + align:start position:0% +l i prime + + + align:start position:0% +l i prime +into + + align:start position:0% +into + + + align:start position:0% +into +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +a quaternion r l i prime + + align:start position:0% +a quaternion r l i prime + + + align:start position:0% +a quaternion r l i prime +and we map this + + align:start position:0% +and we map this + + + align:start position:0% +and we map this +r r i prime into this quaternion and + + align:start position:0% +r r i prime into this quaternion and + + + align:start position:0% +r r i prime into this quaternion and +it's all you've done is add the zero + + align:start position:0% +it's all you've done is add the zero + + + align:start position:0% +it's all you've done is add the zero +scalar part is you know i've also + + align:start position:0% +scalar part is you know i've also + + + align:start position:0% +scalar part is you know i've also +flipped them around because you know dot + + align:start position:0% +flipped them around because you know dot + + + align:start position:0% +flipped them around because you know dot +products commute so i can do that + + align:start position:0% +products commute so i can do that + + + align:start position:0% +products commute so i can do that +okay and this is where i use that trick + + align:start position:0% +okay and this is where i use that trick + + + align:start position:0% +okay and this is where i use that trick +remember i said that sometimes you want + + align:start position:0% +remember i said that sometimes you want + + + align:start position:0% +remember i said that sometimes you want +to move something from one side of a dot + + align:start position:0% +to move something from one side of a dot + + + align:start position:0% +to move something from one side of a dot +product to the other + + align:start position:0% +product to the other + + + align:start position:0% +product to the other +here i've taken this + + align:start position:0% +here i've taken this + + + align:start position:0% +here i've taken this +quaternion flipped it to the other side + + align:start position:0% +quaternion flipped it to the other side + + + align:start position:0% +quaternion flipped it to the other side +but i had to conjugate it + + align:start position:0% +but i had to conjugate it + + + align:start position:0% +but i had to conjugate it +now it's already conjugated so conjugate + + align:start position:0% +now it's already conjugated so conjugate + + + align:start position:0% +now it's already conjugated so conjugate +of the conjugate is the thing itself so + + align:start position:0% +of the conjugate is the thing itself so + + + align:start position:0% +of the conjugate is the thing itself so +i get this expression + + align:start position:0% +i get this expression + + + align:start position:0% +i get this expression +and then i make use of the uh property + + align:start position:0% +and then i make use of the uh property + + + align:start position:0% +and then i make use of the uh property +that i can write this quaternion product + + align:start position:0% +that i can write this quaternion product + + + align:start position:0% +that i can write this quaternion product +as a matrix times vector and i can write + + align:start position:0% +as a matrix times vector and i can write + + + align:start position:0% +as a matrix times vector and i can write +this as a matrix times vector so i get + + align:start position:0% +this as a matrix times vector so i get + + + align:start position:0% +this as a matrix times vector so i get +so i get that + + align:start position:0% +so i get that + + + align:start position:0% +so i get that +and then i make use of the fact that a + + align:start position:0% +and then i make use of the fact that a + + + align:start position:0% +and then i make use of the fact that a +dot product is just the left thing + + align:start position:0% +dot product is just the left thing + + + align:start position:0% +dot product is just the left thing +transposed multiplied by the right thing + + align:start position:0% +transposed multiplied by the right thing + + + align:start position:0% +transposed multiplied by the right thing +and then finally i can pull out the q + + align:start position:0% +and then finally i can pull out the q + + + align:start position:0% +and then finally i can pull out the q +so so this is important i can + + align:start position:0% +so so this is important i can + + + align:start position:0% +so so this is important i can +you know separate out the cube on both + + align:start position:0% +you know separate out the cube on both + + + align:start position:0% +you know separate out the cube on both +sides so it doesn't it doesn't vary with + + align:start position:0% +sides so it doesn't it doesn't vary with + + + align:start position:0% +sides so it doesn't it doesn't vary with +i + + align:start position:0% +i + + + align:start position:0% +i +and so i end up with this + + align:start position:0% +and so i end up with this + + + align:start position:0% +and so i end up with this +product + + align:start position:0% + + + + align:start position:0% + +so this is where all my data is all my + + align:start position:0% +so this is where all my data is all my + + + align:start position:0% +so this is where all my data is all my +measurements are buried in here this is + + align:start position:0% +measurements are buried in here this is + + + align:start position:0% +measurements are buried in here this is +a four by four matrix that i get from my + + align:start position:0% +a four by four matrix that i get from my + + + align:start position:0% +a four by four matrix that i get from my +measurements and now all i want to do is + + align:start position:0% +measurements and now all i want to do is + + + align:start position:0% +measurements and now all i want to do is +make this thing as large as possible + + align:start position:0% +make this thing as large as possible + + + align:start position:0% +make this thing as large as possible +well you know uh not quite + + align:start position:0% +well you know uh not quite + + + align:start position:0% +well you know uh not quite +because i can make this as large as i + + align:start position:0% +because i can make this as large as i + + + align:start position:0% +because i can make this as large as i +like by making q large right + + align:start position:0% +like by making q large right + + + align:start position:0% +like by making q large right +so i have to be careful to impose that + + align:start position:0% +so i have to be careful to impose that + + + align:start position:0% +so i have to be careful to impose that +constraint and so that's + + align:start position:0% +constraint and so that's + + + align:start position:0% +constraint and so that's +uh so quaternions are not a redundant + + align:start position:0% +uh so quaternions are not a redundant + + + align:start position:0% +uh so quaternions are not a redundant +representation because they have four + + align:start position:0% +representation because they have four + + + align:start position:0% +representation because they have four +degree four numbers + + align:start position:0% +degree four numbers + + + align:start position:0% +degree four numbers +and you have to impose this extra + + align:start position:0% +and you have to impose this extra + + + align:start position:0% +and you have to impose this extra +constraint okay and then the different + + align:start position:0% +constraint okay and then the different + + + align:start position:0% +constraint okay and then the different +ways of doing this so first of all + + align:start position:0% +ways of doing this so first of all + + + align:start position:0% +ways of doing this so first of all +let's see what is n well n is again + + align:start position:0% +let's see what is n well n is again + + + align:start position:0% +let's see what is n well n is again +got from the data + + align:start position:0% +got from the data + + + align:start position:0% +got from the data +and there are two ways to do this if you + + align:start position:0% +and there are two ways to do this if you + + + align:start position:0% +and there are two ways to do this if you +know about lagrange multipliers you can + + align:start position:0% +know about lagrange multipliers you can + + + align:start position:0% +know about lagrange multipliers you can +add another term that imposes the + + align:start position:0% +add another term that imposes the + + + align:start position:0% +add another term that imposes the +constraint so the constraint is that q + + align:start position:0% +constraint so the constraint is that q + + + align:start position:0% +constraint so the constraint is that q +dot q equals one + + align:start position:0% +dot q equals one + + + align:start position:0% +dot q equals one +or minus one minus q dot q equals zero + + align:start position:0% +or minus one minus q dot q equals zero + + + align:start position:0% +or minus one minus q dot q equals zero +so you can impose that way and we'll do + + align:start position:0% +so you can impose that way and we'll do + + + align:start position:0% +so you can impose that way and we'll do +it another way that doesn't involve + + align:start position:0% +it another way that doesn't involve + + + align:start position:0% +it another way that doesn't involve +needing to know about lagrange + + align:start position:0% +needing to know about lagrange + + + align:start position:0% +needing to know about lagrange +multipliers + + align:start position:0% +multipliers + + + align:start position:0% +multipliers +anyway in either method we can now + + align:start position:0% +anyway in either method we can now + + + align:start position:0% +anyway in either method we can now +differentiate with respect to q which is + + align:start position:0% +differentiate with respect to q which is + + + align:start position:0% +differentiate with respect to q which is +you know + + align:start position:0% +you know + + + align:start position:0% +you know +amazing we can differentiate with + + align:start position:0% +amazing we can differentiate with + + + align:start position:0% +amazing we can differentiate with +respect to rotation of course in the + + align:start position:0% +respect to rotation of course in the + + + align:start position:0% +respect to rotation of course in the +case of translation you know no one's + + align:start position:0% +case of translation you know no one's + + + align:start position:0% +case of translation you know no one's +surprised you can differentiate with + + align:start position:0% +surprised you can differentiate with + + + align:start position:0% +surprised you can differentiate with +respect to translation or position but + + align:start position:0% +respect to translation or position but + + + align:start position:0% +respect to translation or position but +for rotation that's quite something + + align:start position:0% +for rotation that's quite something + + + align:start position:0% +for rotation that's quite something +if we do + + align:start position:0% +if we do + + + align:start position:0% +if we do +we get this and this is just using the + + align:start position:0% +we get this and this is just using the + + + align:start position:0% +we get this and this is just using the +ordinary rules for + + align:start position:0% +ordinary rules for + + + align:start position:0% +ordinary rules for +differentiation of a dot product and + + align:start position:0% +differentiation of a dot product and + + + align:start position:0% +differentiation of a dot product and +differentiation of a matrix times a + + align:start position:0% +differentiation of a matrix times a + + + align:start position:0% +differentiation of a matrix times a +vector which by the way are in the + + align:start position:0% +vector which by the way are in the + + + align:start position:0% +vector which by the way are in the +appendix of the book which by the way is + + align:start position:0% +appendix of the book which by the way is + + + align:start position:0% +appendix of the book which by the way is +on stellar so if you need to refresh + + align:start position:0% +on stellar so if you need to refresh + + + align:start position:0% +on stellar so if you need to refresh +your memory about differentiating with + + align:start position:0% +your memory about differentiating with + + + align:start position:0% +your memory about differentiating with +respect to a vector it's all there + + align:start position:0% +respect to a vector it's all there + + + align:start position:0% +respect to a vector it's all there +and so what does this say well this says + + align:start position:0% +and so what does this say well this says + + + align:start position:0% +and so what does this say well this says +that nq equals lambda q + + align:start position:0% +that nq equals lambda q + + + align:start position:0% +that nq equals lambda q +well that should remind you of stuff + + align:start position:0% +well that should remind you of stuff + + + align:start position:0% +well that should remind you of stuff +we've done before right it's an + + align:start position:0% +we've done before right it's an + + + align:start position:0% +we've done before right it's an +eigenvector + + align:start position:0% +eigenvector + + + align:start position:0% +eigenvector +so q has to be an eigenvector and lambda + + align:start position:0% +so q has to be an eigenvector and lambda + + + align:start position:0% +so q has to be an eigenvector and lambda +is the eigenvalue + + align:start position:0% +is the eigenvalue + + + align:start position:0% +is the eigenvalue +and since we want to make this as large + + align:start position:0% +and since we want to make this as large + + + align:start position:0% +and since we want to make this as large +as possible we pick the eigenvector that + + align:start position:0% +as possible we pick the eigenvector that + + + align:start position:0% +as possible we pick the eigenvector that +corresponds to the largest eigen which + + align:start position:0% +corresponds to the largest eigen which + + + align:start position:0% +corresponds to the largest eigen which +is sort of unusual in the past we've + + align:start position:0% +is sort of unusual in the past we've + + + align:start position:0% +is sort of unusual in the past we've +always wanted to minimize something we + + align:start position:0% +always wanted to minimize something we + + + align:start position:0% +always wanted to minimize something we +wanted the smallest + + align:start position:0% +wanted the smallest + + + align:start position:0% +wanted the smallest +eigenvalue here because of that sine + + align:start position:0% +eigenvalue here because of that sine + + + align:start position:0% +eigenvalue here because of that sine +flip we want the largest one + + align:start position:0% +flip we want the largest one + + + align:start position:0% +flip we want the largest one +and what is it the eigenvector of it's a + + align:start position:0% +and what is it the eigenvector of it's a + + + align:start position:0% +and what is it the eigenvector of it's a +four by four real symmetric matrix + + align:start position:0% +four by four real symmetric matrix + + + align:start position:0% +four by four real symmetric matrix +which is constructed from the data + + align:start position:0% +which is constructed from the data + + + align:start position:0% +which is constructed from the data +and um + + align:start position:0% +and um + + + align:start position:0% +and um +so a couple of notes on that so one of + + align:start position:0% +so a couple of notes on that so one of + + + align:start position:0% +so a couple of notes on that so one of +them is + + align:start position:0% +them is + + + align:start position:0% +them is +you know we said for a two by four two + + align:start position:0% +you know we said for a two by four two + + + align:start position:0% +you know we said for a two by four two +by two matrix we actually explicitly + + align:start position:0% +by two matrix we actually explicitly + + + align:start position:0% +by two matrix we actually explicitly +gave the eigenvalues and eigenvectors + + align:start position:0% +gave the eigenvalues and eigenvectors + + + align:start position:0% +gave the eigenvalues and eigenvectors +because we know how to solve quadratics + + align:start position:0% +because we know how to solve quadratics + + + align:start position:0% +because we know how to solve quadratics +and i mentioned last time that for 3x3 + + align:start position:0% +and i mentioned last time that for 3x3 + + + align:start position:0% +and i mentioned last time that for 3x3 +it can be done because the + + align:start position:0% +it can be done because the + + + align:start position:0% +it can be done because the +characteristic equation is a cubic + + align:start position:0% +characteristic equation is a cubic + + + align:start position:0% +characteristic equation is a cubic +polynomial in lambda and and someone + + align:start position:0% +polynomial in lambda and and someone + + + align:start position:0% +polynomial in lambda and and someone +knows how to solve cubics in closed form + + align:start position:0% +knows how to solve cubics in closed form + + + align:start position:0% +knows how to solve cubics in closed form +um + + align:start position:0% +um + + + align:start position:0% +um +by the way this used to be + + align:start position:0% +by the way this used to be + + + align:start position:0% +by the way this used to be +a big game particularly amongst the + + align:start position:0% +a big game particularly amongst the + + + align:start position:0% +a big game particularly amongst the +italian mathematicians you know they + + align:start position:0% +italian mathematicians you know they + + + align:start position:0% +italian mathematicians you know they +would this was these problems were real + + align:start position:0% +would this was these problems were real + + + align:start position:0% +would this was these problems were real +puzzled to them and they were very proud + + align:start position:0% +puzzled to them and they were very proud + + + align:start position:0% +puzzled to them and they were very proud +when they saw them you know correctly so + + align:start position:0% +when they saw them you know correctly so + + + align:start position:0% +when they saw them you know correctly so +but there was uh there wasn't the same + + align:start position:0% +but there was uh there wasn't the same + + + align:start position:0% +but there was uh there wasn't the same +sort of modern you know publication and + + align:start position:0% +sort of modern you know publication and + + + align:start position:0% +sort of modern you know publication and +tenure and whatever it's like you've + + align:start position:0% +tenure and whatever it's like you've + + + align:start position:0% +tenure and whatever it's like you've +solved this tough problem and you know + + align:start position:0% +solved this tough problem and you know + + + align:start position:0% +solved this tough problem and you know +you're very proud of it what do you do + + align:start position:0% +you're very proud of it what do you do + + + align:start position:0% +you're very proud of it what do you do +with it you don't want to just give it + + align:start position:0% +with it you don't want to just give it + + + align:start position:0% +with it you don't want to just give it +away and yet you want to be able to say + + align:start position:0% +away and yet you want to be able to say + + + align:start position:0% +away and yet you want to be able to say +later you know i got that 10 years ago + + align:start position:0% +later you know i got that 10 years ago + + + align:start position:0% +later you know i got that 10 years ago +so they'd come up with all these weird + + align:start position:0% +so they'd come up with all these weird + + + align:start position:0% +so they'd come up with all these weird +ways of coding and coding their solution + + align:start position:0% +ways of coding and coding their solution + + + align:start position:0% +ways of coding and coding their solution +and + + align:start position:0% +and + + + align:start position:0% +and +like in a story or as a sort of parable + + align:start position:0% +like in a story or as a sort of parable + + + align:start position:0% +like in a story or as a sort of parable +or some sort of other mathematics and + + align:start position:0% +or some sort of other mathematics and + + + align:start position:0% +or some sort of other mathematics and +then later on you know ferrari who was + + align:start position:0% +then later on you know ferrari who was + + + align:start position:0% +then later on you know ferrari who was +one of the guys who did this could say + + align:start position:0% +one of the guys who did this could say + + + align:start position:0% +one of the guys who did this could say +that oh i solved this years before + + align:start position:0% +that oh i solved this years before + + + align:start position:0% +that oh i solved this years before +cardano who is another guy because look + + align:start position:0% +cardano who is another guy because look + + + align:start position:0% +cardano who is another guy because look +at that poem i wrote it tells you how to + + align:start position:0% +at that poem i wrote it tells you how to + + + align:start position:0% +at that poem i wrote it tells you how to +do this so anyway + + align:start position:0% +do this so anyway + + + align:start position:0% +do this so anyway +they discovered how to solve cubics + + align:start position:0% +they discovered how to solve cubics + + + align:start position:0% +they discovered how to solve cubics +here we're going to have a quartic right + + align:start position:0% +here we're going to have a quartic right + + + align:start position:0% +here we're going to have a quartic right +because it's four by four it's going to + + align:start position:0% +because it's four by four it's going to + + + align:start position:0% +because it's four by four it's going to +be fourth order and guess what + + align:start position:0% +be fourth order and guess what + + + align:start position:0% +be fourth order and guess what +they have closed form solutions and + + align:start position:0% +they have closed form solutions and + + + align:start position:0% +they have closed form solutions and +those italian mathematicians and others + + align:start position:0% +those italian mathematicians and others + + + align:start position:0% +those italian mathematicians and others +figured out how to how to do do it + + align:start position:0% +figured out how to how to do do it + + + align:start position:0% +figured out how to how to do do it +basically how do you do any of these + + align:start position:0% +basically how do you do any of these + + + align:start position:0% +basically how do you do any of these +things well the usual trick you try and + + align:start position:0% +things well the usual trick you try and + + + align:start position:0% +things well the usual trick you try and +find a way of reducing third order to + + align:start position:0% +find a way of reducing third order to + + + align:start position:0% +find a way of reducing third order to +second order because you know how to do + + align:start position:0% +second order because you know how to do + + + align:start position:0% +second order because you know how to do +second order + + align:start position:0% +second order + + + align:start position:0% +second order +and + + align:start position:0% +and + + + align:start position:0% +and +quartics + + align:start position:0% +quartics + + + align:start position:0% +quartics +first step is reduce it to a cubic solve + + align:start position:0% +first step is reduce it to a cubic solve + + + align:start position:0% +first step is reduce it to a cubic solve +the cubic and then the rest is easy + + align:start position:0% +the cubic and then the rest is easy + + + align:start position:0% +the cubic and then the rest is easy +and so uh can you solve fifth order + + align:start position:0% + + + + align:start position:0% + +no + + align:start position:0% +no + + + align:start position:0% +no +okay so it's good that some of you know + + align:start position:0% +okay so it's good that some of you know + + + align:start position:0% +okay so it's good that some of you know +that that's it you can't now of course + + align:start position:0% +that that's it you can't now of course + + + align:start position:0% +that that's it you can't now of course +today with computers we can always + + align:start position:0% +today with computers we can always + + + align:start position:0% +today with computers we can always +numerically solve any of these but + + align:start position:0% +numerically solve any of these but + + + align:start position:0% +numerically solve any of these but +if you want to + + align:start position:0% +if you want to + + + align:start position:0% +if you want to +have a quote closed form solution + + align:start position:0% +have a quote closed form solution + + + align:start position:0% +have a quote closed form solution +you know then you do need to know that + + align:start position:0% +you know then you do need to know that + + + align:start position:0% +you know then you do need to know that +you can solve one two three four but + + align:start position:0% +you can solve one two three four but + + + align:start position:0% +you can solve one two three four but +that's it then higher order you can't + + align:start position:0% +that's it then higher order you can't + + + align:start position:0% +that's it then higher order you can't +solve in closed form using addition + + align:start position:0% +solve in closed form using addition + + + align:start position:0% +solve in closed form using addition +subtraction multiplication and square + + align:start position:0% +subtraction multiplication and square + + + align:start position:0% +subtraction multiplication and square +roots + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so + + align:start position:0% +so + + + align:start position:0% +so +this matrix down here + + align:start position:0% +this matrix down here + + + align:start position:0% +this matrix down here +it look is more familiar to you than n + + align:start position:0% +it look is more familiar to you than n + + + align:start position:0% +it look is more familiar to you than n +that's because this is simply the diatic + + align:start position:0% +that's because this is simply the diatic + + + align:start position:0% +that's because this is simply the diatic +product of the vector in the left + + align:start position:0% +product of the vector in the left + + + align:start position:0% +product of the vector in the left +coordinate system and the vector in the + + align:start position:0% +coordinate system and the vector in the + + + align:start position:0% +coordinate system and the vector in the +right coordinate system so this is a + + align:start position:0% +right coordinate system so this is a + + + align:start position:0% +right coordinate system so this is a +three by three each of these is a three + + align:start position:0% +three by three each of these is a three + + + align:start position:0% +three by three each of these is a three +by three matrix + + align:start position:0% +by three matrix + + + align:start position:0% +by three matrix +that's a dyadic product and you just + + align:start position:0% +that's a dyadic product and you just + + + align:start position:0% +that's a dyadic product and you just +keep on going stepping through your + + align:start position:0% +keep on going stepping through your + + + align:start position:0% +keep on going stepping through your +point pairs and adding them up and you + + align:start position:0% +point pairs and adding them up and you + + + align:start position:0% +point pairs and adding them up and you +get a three by three matrix + + align:start position:0% +get a three by three matrix + + + align:start position:0% +get a three by three matrix +which is not symmetric um + + align:start position:0% +which is not symmetric um + + + align:start position:0% +which is not symmetric um +and so it has nine independent + + align:start position:0% +and so it has nine independent + + + align:start position:0% +and so it has nine independent +quantities + + align:start position:0% +quantities + + + align:start position:0% +quantities +and let's think about n + + align:start position:0% +and let's think about n + + + align:start position:0% +and let's think about n +well uh n um + + align:start position:0% +well uh n um + + + align:start position:0% +well uh n um +is four by four so it has 16 so so how + + align:start position:0% +is four by four so it has 16 so so how + + + align:start position:0% +is four by four so it has 16 so so how +does that work + + align:start position:0% +does that work + + + align:start position:0% +does that work +um + + align:start position:0% +um + + + align:start position:0% +um +it turns out that uh n is rather special + + align:start position:0% +it turns out that uh n is rather special + + + align:start position:0% +it turns out that uh n is rather special +it turns out n is symmetric and and uh + + align:start position:0% +it turns out n is symmetric and and uh + + + align:start position:0% +it turns out n is symmetric and and uh +it turns out that it's not that easy to + + align:start position:0% +it turns out that it's not that easy to + + + align:start position:0% +it turns out that it's not that easy to +prove and + + align:start position:0% +prove and + + + align:start position:0% +prove and +the one mistake in this paper was that + + align:start position:0% +the one mistake in this paper was that + + + align:start position:0% +the one mistake in this paper was that +um i think i said something like it's + + align:start position:0% +um i think i said something like it's + + + align:start position:0% +um i think i said something like it's +obvious that it's symmetric but + + align:start position:0% +obvious that it's symmetric but + + + align:start position:0% +obvious that it's symmetric but +it takes some anyway it's symmetric so + + align:start position:0% +it takes some anyway it's symmetric so + + + align:start position:0% +it takes some anyway it's symmetric so +that means four by four symmetric we've + + align:start position:0% +that means four by four symmetric we've + + + align:start position:0% +that means four by four symmetric we've +got uh four on the diagonal and then we + + align:start position:0% +got uh four on the diagonal and then we + + + align:start position:0% +got uh four on the diagonal and then we +have um + + align:start position:0% +have um + + + align:start position:0% +have um +six more no ten we have ten independent + + align:start position:0% +six more no ten we have ten independent + + + align:start position:0% +six more no ten we have ten independent +so it's not sixteen but it's ten but + + align:start position:0% +so it's not sixteen but it's ten but + + + align:start position:0% +so it's not sixteen but it's ten but +it's still it's still too many right + + align:start position:0% +it's still it's still too many right + + + align:start position:0% +it's still it's still too many right +because we only have 9 in m well it + + align:start position:0% +because we only have 9 in m well it + + + align:start position:0% +because we only have 9 in m well it +turns out that this matrix is very + + align:start position:0% +turns out that this matrix is very + + + align:start position:0% +turns out that this matrix is very +special because + + align:start position:0% +special because + + + align:start position:0% +special because +the determinant the characteristic + + align:start position:0% +the determinant the characteristic + + + align:start position:0% +the determinant the characteristic +equation + + align:start position:0% +equation + + + align:start position:0% +equation +up here has some has this important + + align:start position:0% +up here has some has this important + + + align:start position:0% +up here has some has this important +property that + + align:start position:0% +property that + + + align:start position:0% +property that +that cubic term is zero which actually + + align:start position:0% +that cubic term is zero which actually + + + align:start position:0% +that cubic term is zero which actually +makes it easier to reduce it to a cubic + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +so n is a symmetric four by four matrix + + align:start position:0% +so n is a symmetric four by four matrix + + + align:start position:0% +so n is a symmetric four by four matrix +with a trace of zero so that means we've + + align:start position:0% +with a trace of zero so that means we've + + + align:start position:0% +with a trace of zero so that means we've +got ten minus one is nine so that so now + + align:start position:0% +got ten minus one is nine so that so now + + + align:start position:0% +got ten minus one is nine so that so now +it matches + + align:start position:0% +it matches + + + align:start position:0% +it matches +m has nine independent values okay we + + align:start position:0% +m has nine independent values okay we + + + align:start position:0% +m has nine independent values okay we +don't need to really know and if you're + + align:start position:0% +don't need to really know and if you're + + + align:start position:0% +don't need to really know and if you're +actually gonna implement this you might + + align:start position:0% +actually gonna implement this you might + + + align:start position:0% +actually gonna implement this you might +want to know this but + + align:start position:0% +want to know this but + + + align:start position:0% +want to know this but +just to know that you can compute all + + align:start position:0% +just to know that you can compute all + + + align:start position:0% +just to know that you can compute all +the coefficients of the characteristic + + align:start position:0% +the coefficients of the characteristic + + + align:start position:0% +the coefficients of the characteristic +equation and then you go off and solve + + align:start position:0% +equation and then you go off and solve + + + align:start position:0% +equation and then you go off and solve +your quotient + + align:start position:0% +your quotient + + + align:start position:0% +your quotient +so the main application is going to be + + align:start position:0% +so the main application is going to be + + + align:start position:0% +so the main application is going to be +absolute orientation + + align:start position:0% +absolute orientation + + + align:start position:0% +absolute orientation +but it also has lots of other + + align:start position:0% +but it also has lots of other + + + align:start position:0% +but it also has lots of other +applications that we you know already + + align:start position:0% +applications that we you know already + + + align:start position:0% +applications that we you know already +talked about + + align:start position:0% +talked about + + + align:start position:0% +talked about +and in + + align:start position:0% +and in + + + align:start position:0% +and in +if you go over to draper lab where they + + align:start position:0% +if you go over to draper lab where they + + + align:start position:0% +if you go over to draper lab where they +do all this uh spacecraft control + + align:start position:0% +do all this uh spacecraft control + + + align:start position:0% +do all this uh spacecraft control +you'll find people who uh know about + + align:start position:0% +you'll find people who uh know about + + + align:start position:0% +you'll find people who uh know about +quaternions because that's what's used + + align:start position:0% +quaternions because that's what's used + + + align:start position:0% +quaternions because that's what's used +there + + align:start position:0% +there + + + align:start position:0% +there +desirable properties so we had this + + align:start position:0% +desirable properties so we had this + + + align:start position:0% +desirable properties so we had this +table let's see how we're doing + + align:start position:0% +table let's see how we're doing + + + align:start position:0% +table let's see how we're doing +ability to rotate vectors yes we q r q + + align:start position:0% +ability to rotate vectors yes we q r q + + + align:start position:0% +ability to rotate vectors yes we q r q +conjugate + + align:start position:0% +conjugate + + + align:start position:0% +conjugate +ability compose rotations yes p times q + + align:start position:0% +ability compose rotations yes p times q + + + align:start position:0% +ability compose rotations yes p times q +is the composition + + align:start position:0% +is the composition + + + align:start position:0% +is the composition +intuitive non-redundant representation + + align:start position:0% +intuitive non-redundant representation + + + align:start position:0% +intuitive non-redundant representation +well it's almost non-redundant it has + + align:start position:0% +well it's almost non-redundant it has + + + align:start position:0% +well it's almost non-redundant it has +four numbers to represent three degrees + + align:start position:0% +four numbers to represent three degrees + + + align:start position:0% +four numbers to represent three degrees +of freedom + + align:start position:0% +of freedom + + + align:start position:0% +of freedom +and but the redundancy is very simple + + align:start position:0% +and but the redundancy is very simple + + + align:start position:0% +and but the redundancy is very simple +it's just the unit unit quaternion uh is + + align:start position:0% +it's just the unit unit quaternion uh is + + + align:start position:0% +it's just the unit unit quaternion uh is +it intuitive + + align:start position:0% +it intuitive + + + align:start position:0% +it intuitive +you know one part the the vector part is + + align:start position:0% +you know one part the the vector part is + + + align:start position:0% +you know one part the the vector part is +in the direction of the axis that sort + + align:start position:0% +in the direction of the axis that sort + + + align:start position:0% +in the direction of the axis that sort +of intuitive + + align:start position:0% +of intuitive + + + align:start position:0% +of intuitive +computational efficiency we haven't + + align:start position:0% +computational efficiency we haven't + + + align:start position:0% +computational efficiency we haven't +talked about that yet you know how does + + align:start position:0% +talked about that yet you know how does + + + align:start position:0% +talked about that yet you know how does +it compare with matrix operations + + align:start position:0% +it compare with matrix operations + + + align:start position:0% +it compare with matrix operations +uh can we do things like interpolate + + align:start position:0% +uh can we do things like interpolate + + + align:start position:0% +uh can we do things like interpolate +orientations yes + + align:start position:0% +orientations yes + + + align:start position:0% +orientations yes +you know suppose that you have um + + align:start position:0% +you know suppose that you have um + + + align:start position:0% +you know suppose that you have um +your artist has the ballerina doing a + + align:start position:0% +your artist has the ballerina doing a + + + align:start position:0% +your artist has the ballerina doing a +turn and got it got her in this position + + align:start position:0% +turn and got it got her in this position + + + align:start position:0% +turn and got it got her in this position +and then in that position + + align:start position:0% +and then in that position + + + align:start position:0% +and then in that position +uh rotate it + + align:start position:0% +uh rotate it + + + align:start position:0% +uh rotate it +how do you do all the in-betweening + + align:start position:0% +how do you do all the in-betweening + + + align:start position:0% +how do you do all the in-betweening +do you take the initial rotation matrix + + align:start position:0% +do you take the initial rotation matrix + + + align:start position:0% +do you take the initial rotation matrix +and the final rotation matrix takes some + + align:start position:0% +and the final rotation matrix takes some + + + align:start position:0% +and the final rotation matrix takes some +sort of weighted average + + align:start position:0% +sort of weighted average + + + align:start position:0% +sort of weighted average +well that's not going to be orthonormal + + align:start position:0% +well that's not going to be orthonormal + + + align:start position:0% +well that's not going to be orthonormal +so here it's trivial + + align:start position:0% +so here it's trivial + + + align:start position:0% +so here it's trivial +right you just + + align:start position:0% +right you just + + + align:start position:0% +right you just +take that angle suppose that the + + align:start position:0% +take that angle suppose that the + + + align:start position:0% +take that angle suppose that the +rotation is about an axis through an + + align:start position:0% +rotation is about an axis through an + + + align:start position:0% +rotation is about an axis through an +angle of 90 degrees you just split it up + + align:start position:0% +angle of 90 degrees you just split it up + + + align:start position:0% +angle of 90 degrees you just split it up +into however many frames you need and + + align:start position:0% +into however many frames you need and + + + align:start position:0% +into however many frames you need and +compute the quaternion + + align:start position:0% +compute the quaternion + + + align:start position:0% +compute the quaternion +correspondingly + + align:start position:0% +correspondingly + + + align:start position:0% +correspondingly +we can take averages of a range of + + align:start position:0% +we can take averages of a range of + + + align:start position:0% +we can take averages of a range of +rotations if you want to know + + align:start position:0% +rotations if you want to know + + + align:start position:0% +rotations if you want to know +the average loading on the seat belt as + + align:start position:0% +the average loading on the seat belt as + + + align:start position:0% +the average loading on the seat belt as +your car is tumbling in all possible + + align:start position:0% +your car is tumbling in all possible + + + align:start position:0% +your car is tumbling in all possible +orientations you can easily do that + + align:start position:0% +orientations you can easily do that + + + align:start position:0% +orientations you can easily do that +and we can + + align:start position:0% +and we can + + + align:start position:0% +and we can +take the derivative as we saw so we can + + align:start position:0% +take the derivative as we saw so we can + + + align:start position:0% +take the derivative as we saw so we can +do optimizations least squares + + align:start position:0% +do optimizations least squares + + + align:start position:0% +do optimizations least squares +if if there's no closed form solution we + + align:start position:0% +if if there's no closed form solution we + + + align:start position:0% +if if there's no closed form solution we +at least have a way of sampling that + + align:start position:0% +at least have a way of sampling that + + + align:start position:0% +at least have a way of sampling that +space of possibilities in a uniform or + + align:start position:0% +space of possibilities in a uniform or + + + align:start position:0% +space of possibilities in a uniform or +random way + + align:start position:0% + + + + align:start position:0% + +oh okay well let's see how late is it + + align:start position:0% +oh okay well let's see how late is it + + + align:start position:0% +oh okay well let's see how late is it +well let's do a couple more things + + align:start position:0% +well let's do a couple more things + + + align:start position:0% +well let's do a couple more things +okay so this is where we're going to go + + align:start position:0% +okay so this is where we're going to go + + + align:start position:0% +okay so this is where we're going to go +after absolute orientation this is + + align:start position:0% +after absolute orientation this is + + + align:start position:0% +after absolute orientation this is +relative orientation and this is kind of + + align:start position:0% +relative orientation and this is kind of + + + align:start position:0% +relative orientation and this is kind of +uh more + + align:start position:0% +uh more + + + align:start position:0% +uh more +so absolute orientation is very + + align:start position:0% +so absolute orientation is very + + + align:start position:0% +so absolute orientation is very +important for photogrammetry you know + + align:start position:0% +important for photogrammetry you know + + + align:start position:0% +important for photogrammetry you know +making topographic maps from aerial + + align:start position:0% +making topographic maps from aerial + + + align:start position:0% +making topographic maps from aerial +photographs but in terms of + + align:start position:0% +photographs but in terms of + + + align:start position:0% +photographs but in terms of +understanding human vision you know one + + align:start position:0% +understanding human vision you know one + + + align:start position:0% +understanding human vision you know one +of a dozen depth cues is binocular + + align:start position:0% +of a dozen depth cues is binocular + + + align:start position:0% +of a dozen depth cues is binocular +stereo and so relative orientation there + + align:start position:0% +stereo and so relative orientation there + + + align:start position:0% +stereo and so relative orientation there +is more important and so that's the + + align:start position:0% +is more important and so that's the + + + align:start position:0% +is more important and so that's the +problem of we've got two eyes + + align:start position:0% +problem of we've got two eyes + + + align:start position:0% +problem of we've got two eyes +and the eyes don't get depth uh they + + align:start position:0% +and the eyes don't get depth uh they + + + align:start position:0% +and the eyes don't get depth uh they +only get directions so we have the + + align:start position:0% +only get directions so we have the + + + align:start position:0% +only get directions so we have the +directions in each of those coordinate + + align:start position:0% +directions in each of those coordinate + + + align:start position:0% +directions in each of those coordinate +systems two points out in the world + + align:start position:0% +systems two points out in the world + + + align:start position:0% +systems two points out in the world +and are shown five and it turns out five + + align:start position:0% +and are shown five and it turns out five + + + align:start position:0% +and are shown five and it turns out five +is the minimum number you need to solve + + align:start position:0% +is the minimum number you need to solve + + + align:start position:0% +is the minimum number you need to solve +this problem and your problem is to find + + align:start position:0% +this problem and your problem is to find + + + align:start position:0% +this problem and your problem is to find +out what that baseline is and what the + + align:start position:0% +out what that baseline is and what the + + + align:start position:0% +out what that baseline is and what the +relative orientation of this coordinate + + align:start position:0% +relative orientation of this coordinate + + + align:start position:0% +relative orientation of this coordinate +system is relative to that in other + + align:start position:0% +system is relative to that in other + + + align:start position:0% +system is relative to that in other +words + + align:start position:0% +words + + + align:start position:0% +words +we have a translation and we're going to + + align:start position:0% +we have a translation and we're going to + + + align:start position:0% +we have a translation and we're going to +have a rotation + + align:start position:0% +have a rotation + + + align:start position:0% +have a rotation +so in that respect it's the same problem + + align:start position:0% +so in that respect it's the same problem + + + align:start position:0% +so in that respect it's the same problem +it's just that our data now is not as + + align:start position:0% +it's just that our data now is not as + + + align:start position:0% +it's just that our data now is not as +good but for in absolute orientation we + + align:start position:0% +good but for in absolute orientation we + + + align:start position:0% +good but for in absolute orientation we +actually know 3d coordinates of all of + + align:start position:0% +actually know 3d coordinates of all of + + + align:start position:0% +actually know 3d coordinates of all of +these points and that makes it possible + + align:start position:0% +these points and that makes it possible + + + align:start position:0% +these points and that makes it possible +to get a closed form solution here we + + align:start position:0% +to get a closed form solution here we + + + align:start position:0% +to get a closed form solution here we +only know the directions so that's the + + align:start position:0% +only know the directions so that's the + + + align:start position:0% +only know the directions so that's the +problem we're going to solve after + + align:start position:0% +problem we're going to solve after + + + align:start position:0% +problem we're going to solve after +absolute orientation + + align:start position:0% +absolute orientation + + + align:start position:0% +absolute orientation +um then you know if you're trying to + + align:start position:0% +um then you know if you're trying to + + + align:start position:0% +um then you know if you're trying to +describe the kinematics of a robot + + align:start position:0% +describe the kinematics of a robot + + + align:start position:0% +describe the kinematics of a robot +manipulator + + align:start position:0% +manipulator + + + align:start position:0% +manipulator +well these days people are lazy you just + + align:start position:0% +well these days people are lazy you just + + + align:start position:0% +well these days people are lazy you just +buy it and the software does all that + + align:start position:0% +buy it and the software does all that + + + align:start position:0% +buy it and the software does all that +for you but you know in the old days + + align:start position:0% +for you but you know in the old days + + + align:start position:0% +for you but you know in the old days +uh you know we had to walk in the snow + + align:start position:0% +uh you know we had to walk in the snow + + + align:start position:0% +uh you know we had to walk in the snow +there was no bus well in the old days + + align:start position:0% +there was no bus well in the old days + + + align:start position:0% +there was no bus well in the old days +you actually had to understand the + + align:start position:0% +you actually had to understand the + + + align:start position:0% +you actually had to understand the +geometry of these devices and that means + + align:start position:0% +geometry of these devices and that means + + + align:start position:0% +geometry of these devices and that means +that + + align:start position:0% +that + + + align:start position:0% +that +as you go through each link you are + + align:start position:0% +as you go through each link you are + + + align:start position:0% +as you go through each link you are +doing a translation and a rotation and + + align:start position:0% +doing a translation and a rotation and + + + align:start position:0% +doing a translation and a rotation and +so + + align:start position:0% +so + + + align:start position:0% +so +if you want to avoid problems with + + align:start position:0% +if you want to avoid problems with + + + align:start position:0% +if you want to avoid problems with +coordinate systems lining up + + align:start position:0% +coordinate systems lining up + + + align:start position:0% +coordinate systems lining up +particularly in the wrist + + align:start position:0% +particularly in the wrist + + + align:start position:0% +particularly in the wrist +then quaternions are a good way to + + align:start position:0% +then quaternions are a good way to + + + align:start position:0% +then quaternions are a good way to +represent the rotation so in the wrist + + align:start position:0% +represent the rotation so in the wrist + + + align:start position:0% +represent the rotation so in the wrist +for example you can imagine that if this + + align:start position:0% +for example you can imagine that if this + + + align:start position:0% +for example you can imagine that if this +part now comes up there'll be a time + + align:start position:0% +part now comes up there'll be a time + + + align:start position:0% +part now comes up there'll be a time +where this axis in here is parallel to + + align:start position:0% +where this axis in here is parallel to + + + align:start position:0% +where this axis in here is parallel to +that axis and you've lost the degree of + + align:start position:0% +that axis and you've lost the degree of + + + align:start position:0% +that axis and you've lost the degree of +freedom so + + align:start position:0% + + + + align:start position:0% + +uh computational issues now i guess + + align:start position:0% +uh computational issues now i guess + + + align:start position:0% +uh computational issues now i guess +these days computers are pretty fast so + + align:start position:0% +these days computers are pretty fast so + + + align:start position:0% +these days computers are pretty fast so +we don't worry about this as much but if + + align:start position:0% +we don't worry about this as much but if + + + align:start position:0% +we don't worry about this as much but if +you have to do this for every point in + + align:start position:0% +you have to do this for every point in + + + align:start position:0% +you have to do this for every point in +some object in your graphics + + align:start position:0% +some object in your graphics + + + align:start position:0% +some object in your graphics +representation this this could be an + + align:start position:0% +representation this this could be an + + + align:start position:0% +representation this this could be an +issue + + align:start position:0% +issue + + + align:start position:0% +issue +so let's see how expensive it is so + + align:start position:0% +so let's see how expensive it is so + + + align:start position:0% +so let's see how expensive it is so +again the two things we want to do + + align:start position:0% +again the two things we want to do + + + align:start position:0% +again the two things we want to do +compose rotations and rotate vectors so + + align:start position:0% +compose rotations and rotate vectors so + + + align:start position:0% +compose rotations and rotate vectors so +for composition we know it's just + + align:start position:0% +for composition we know it's just + + + align:start position:0% +for composition we know it's just +multiplying two quaternions and if you + + align:start position:0% +multiplying two quaternions and if you + + + align:start position:0% +multiplying two quaternions and if you +do it the naive way just you following + + align:start position:0% +do it the naive way just you following + + + align:start position:0% +do it the naive way just you following +that formula you get 16 multipliers and + + align:start position:0% +that formula you get 16 multipliers and + + + align:start position:0% +that formula you get 16 multipliers and +12 adds + + align:start position:0% +12 adds + + + align:start position:0% +12 adds +and if you do this with the orthonormal + + align:start position:0% +and if you do this with the orthonormal + + + align:start position:0% +and if you do this with the orthonormal +matrix of course it's a 3x3 matrix + + align:start position:0% +matrix of course it's a 3x3 matrix + + + align:start position:0% +matrix of course it's a 3x3 matrix +product which is 27 multipliers and 18 + + align:start position:0% +product which is 27 multipliers and 18 + + + align:start position:0% +product which is 27 multipliers and 18 +adds so we we win definitely win here + + align:start position:0% +adds so we we win definitely win here + + + align:start position:0% +adds so we we win definitely win here +let's go to rotating a vector so we use + + align:start position:0% +let's go to rotating a vector so we use + + + align:start position:0% +let's go to rotating a vector so we use +this formula + + align:start position:0% +this formula + + + align:start position:0% +this formula +and we can expand out the part we want + + align:start position:0% +and we can expand out the part we want + + + align:start position:0% +and we can expand out the part we want +which is the vector part + + align:start position:0% +which is the vector part + + + align:start position:0% +which is the vector part +22 multiplies 16 ads + + align:start position:0% +22 multiplies 16 ads + + + align:start position:0% +22 multiplies 16 ads +compare the matrix per oops + + align:start position:0% +compare the matrix per oops + + + align:start position:0% +compare the matrix per oops +9 multipliers and 6 ads so here we lose + + align:start position:0% +9 multipliers and 6 ads so here we lose + + + align:start position:0% +9 multipliers and 6 ads so here we lose +but + + align:start position:0% +but + + + align:start position:0% +but +this can be rewritten in this form which + + align:start position:0% +this can be rewritten in this form which + + + align:start position:0% +this can be rewritten in this form which +has the advantage that you compute the + + align:start position:0% +has the advantage that you compute the + + + align:start position:0% +has the advantage that you compute the +qr once and you use it in two different + + align:start position:0% +qr once and you use it in two different + + + align:start position:0% +qr once and you use it in two different +places and you get it down to 15 + + align:start position:0% +places and you get it down to 15 + + + align:start position:0% +places and you get it down to 15 +multipliers and 12 ads + + align:start position:0% +multipliers and 12 ads + + + align:start position:0% +multipliers and 12 ads +and this is naive stuff you know people + + align:start position:0% +and this is naive stuff you know people + + + align:start position:0% +and this is naive stuff you know people +that get serious about this go further + + align:start position:0% +that get serious about this go further + + + align:start position:0% +that get serious about this go further +for example with a three by three matrix + + align:start position:0% +for example with a three by three matrix + + + align:start position:0% +for example with a three by three matrix +uh + + align:start position:0% +uh + + + align:start position:0% +uh +they don't represent it as three by + + align:start position:0% +they don't represent it as three by + + + align:start position:0% +they don't represent it as three by +three matrix at most you take the first + + align:start position:0% +three matrix at most you take the first + + + align:start position:0% +three matrix at most you take the first +two rows because the other one's + + align:start position:0% +two rows because the other one's + + + align:start position:0% +two rows because the other one's +implicit it's a cross product and so + + align:start position:0% +implicit it's a cross product and so + + + align:start position:0% +implicit it's a cross product and so +both so um you know you could have a + + align:start position:0% +both so um you know you could have a + + + align:start position:0% +both so um you know you could have a +competition where you just keep on going + + align:start position:0% +competition where you just keep on going + + + align:start position:0% +competition where you just keep on going +um + + align:start position:0% +um + + + align:start position:0% +um +on both sides + + align:start position:0% +on both sides + + + align:start position:0% +on both sides +and they end up uh being similar + + align:start position:0% +and they end up uh being similar + + + align:start position:0% +and they end up uh being similar +uh + + align:start position:0% +uh + + + align:start position:0% +uh +but with the advantage for composition + + align:start position:0% +but with the advantage for composition + + + align:start position:0% +but with the advantage for composition +going to quaternions and the advantage + + align:start position:0% +going to quaternions and the advantage + + + align:start position:0% +going to quaternions and the advantage +for + + align:start position:0% +for + + + align:start position:0% +for +rotating vectors going to um + + align:start position:0% +rotating vectors going to um + + + align:start position:0% +rotating vectors going to um +orthonormal + + align:start position:0% +orthonormal + + + align:start position:0% +orthonormal +okay how about + + align:start position:0% +okay how about + + + align:start position:0% +okay how about +re-normalizing so one of the things that + + align:start position:0% +re-normalizing so one of the things that + + + align:start position:0% +re-normalizing so one of the things that +happens suppose you have a graphic + + align:start position:0% +happens suppose you have a graphic + + + align:start position:0% +happens suppose you have a graphic +program that's trying to + + align:start position:0% +program that's trying to + + + align:start position:0% +program that's trying to +do some motion sequence and you're + + align:start position:0% +do some motion sequence and you're + + + align:start position:0% +do some motion sequence and you're +composing small incremental rotations + + align:start position:0% +composing small incremental rotations + + + align:start position:0% +composing small incremental rotations +and if you represent them let's say as + + align:start position:0% +and if you represent them let's say as + + + align:start position:0% +and if you represent them let's say as +orthogonal matrices you can imagine that + + align:start position:0% +orthogonal matrices you can imagine that + + + align:start position:0% +orthogonal matrices you can imagine that +because of the limitations of floating + + align:start position:0% +because of the limitations of floating + + + align:start position:0% +because of the limitations of floating +point arithmetic that errors will + + align:start position:0% +point arithmetic that errors will + + + align:start position:0% +point arithmetic that errors will +accumulate and after a while your three + + align:start position:0% +accumulate and after a while your three + + + align:start position:0% +accumulate and after a while your three +by three matrix is no longer orthonormal + + align:start position:0% +by three matrix is no longer orthonormal + + + align:start position:0% +by three matrix is no longer orthonormal +and so you'd want to sort of square it + + align:start position:0% +and so you'd want to sort of square it + + + align:start position:0% +and so you'd want to sort of square it +up + + align:start position:0% +up + + + align:start position:0% +up +and that can be done + + align:start position:0% +and that can be done + + + align:start position:0% +and that can be done +but it requires doing this you take your + + align:start position:0% +but it requires doing this you take your + + + align:start position:0% +but it requires doing this you take your +matrix m you multiply you take its + + align:start position:0% +matrix m you multiply you take its + + + align:start position:0% +matrix m you multiply you take its +transpose multiplied by m and you take + + align:start position:0% +transpose multiplied by m and you take + + + align:start position:0% +transpose multiplied by m and you take +the inverse of the square root of the + + align:start position:0% +the inverse of the square root of the + + + align:start position:0% +the inverse of the square root of the +matrix so you know right there you + + align:start position:0% +matrix so you know right there you + + + align:start position:0% +matrix so you know right there you +i'd imagine that you may not know how to + + align:start position:0% +i'd imagine that you may not know how to + + + align:start position:0% +i'd imagine that you may not know how to +do that but it can be done but that just + + align:start position:0% +do that but it can be done but that just + + + align:start position:0% +do that but it can be done but that just +suggests that this is not an operation + + align:start position:0% +suggests that this is not an operation + + + align:start position:0% +suggests that this is not an operation +that you'd normally want to do it's it's + + align:start position:0% +that you'd normally want to do it's it's + + + align:start position:0% +that you'd normally want to do it's it's +expensive + + align:start position:0% +expensive + + + align:start position:0% +expensive +with quaternions sure enough you take + + align:start position:0% +with quaternions sure enough you take + + + align:start position:0% +with quaternions sure enough you take +the unit quaternion you multiply it by + + align:start position:0% +the unit quaternion you multiply it by + + + align:start position:0% +the unit quaternion you multiply it by +another unit quaternion and so on and + + align:start position:0% +another unit quaternion and so on and + + + align:start position:0% +another unit quaternion and so on and +because of the limitations of floating + + align:start position:0% +because of the limitations of floating + + + align:start position:0% +because of the limitations of floating +point arithmetic after a while it isn't + + align:start position:0% +point arithmetic after a while it isn't + + + align:start position:0% +point arithmetic after a while it isn't +a unit quaternion how do you square it + + align:start position:0% +a unit quaternion how do you square it + + + align:start position:0% +a unit quaternion how do you square it +up well you know trivial so + + align:start position:0% +up well you know trivial so + + + align:start position:0% +up well you know trivial so +so this is + + align:start position:0% +so this is + + + align:start position:0% +so this is +one other small difference between them + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +um + + align:start position:0% +um + + + align:start position:0% +um +uh just about at the end so we talked + + align:start position:0% +uh just about at the end so we talked + + + align:start position:0% +uh just about at the end so we talked +about the space of rotation being uh + + align:start position:0% +about the space of rotation being uh + + + align:start position:0% +about the space of rotation being uh +this uh three three sphere + + align:start position:0% +this uh three three sphere + + + align:start position:0% +this uh three three sphere +unit sphere and four d with antipodal + + align:start position:0% +unit sphere and four d with antipodal + + + align:start position:0% +unit sphere and four d with antipodal +points identified and it also happens to + + align:start position:0% +points identified and it also happens to + + + align:start position:0% +points identified and it also happens to +be identical to the projective space p3 + + align:start position:0% +be identical to the projective space p3 + + + align:start position:0% +be identical to the projective space p3 +although we don't use that and it's + + align:start position:0% +although we don't use that and it's + + + align:start position:0% +although we don't use that and it's +not as handy + + align:start position:0% +not as handy + + + align:start position:0% +not as handy +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +then + + align:start position:0% +then + + + align:start position:0% +then +sampling regular and random so how do we + + align:start position:0% +sampling regular and random so how do we + + + align:start position:0% +sampling regular and random so how do we +sample this space well you know in 3d we + + align:start position:0% +sample this space well you know in 3d we + + + align:start position:0% +sample this space well you know in 3d we +can easily come up with a regular + + align:start position:0% +can easily come up with a regular + + + align:start position:0% +can easily come up with a regular +sampling + + align:start position:0% +sampling + + + align:start position:0% +sampling +of space or even a random sampling but + + align:start position:0% +of space or even a random sampling but + + + align:start position:0% +of space or even a random sampling but +it's not so obvious how to do it here + + align:start position:0% +it's not so obvious how to do it here + + + align:start position:0% +it's not so obvious how to do it here +and one way + + align:start position:0% +and one way + + + align:start position:0% +and one way +is to + + align:start position:0% +is to + + + align:start position:0% +is to +find regular patterns + + align:start position:0% +find regular patterns + + + align:start position:0% +find regular patterns +you know if we're + + align:start position:0% +you know if we're + + + align:start position:0% +you know if we're +say we want to sample a sphere regularly + + align:start position:0% +say we want to sample a sphere regularly + + + align:start position:0% +say we want to sample a sphere regularly +that's not so easy either certainly + + align:start position:0% +that's not so easy either certainly + + + align:start position:0% +that's not so easy either certainly +latitude and longitude's not going to do + + align:start position:0% +latitude and longitude's not going to do + + + align:start position:0% +latitude and longitude's not going to do +it but one thing we can do is project + + align:start position:0% +it but one thing we can do is project + + + align:start position:0% +it but one thing we can do is project +polyhedra onto it because polyhedra are + + align:start position:0% +polyhedra onto it because polyhedra are + + + align:start position:0% +polyhedra onto it because polyhedra are +completely regular so if we project say + + align:start position:0% +completely regular so if we project say + + + align:start position:0% +completely regular so if we project say +a icosahedron + + align:start position:0% +a icosahedron + + + align:start position:0% +a icosahedron +or a dodeca icosahedron which is + + align:start position:0% +or a dodeca icosahedron which is + + + align:start position:0% +or a dodeca icosahedron which is +a soccer ball + + align:start position:0% +a soccer ball + + + align:start position:0% +a soccer ball +anyone here know about soccer uh + + align:start position:0% +anyone here know about soccer uh + + + align:start position:0% +anyone here know about soccer uh +then we end up with a pattern on the + + align:start position:0% +then we end up with a pattern on the + + + align:start position:0% +then we end up with a pattern on the +sphere that is regular but they're only + + align:start position:0% +sphere that is regular but they're only + + + align:start position:0% +sphere that is regular but they're only +some special ones like uh regular solids + + align:start position:0% +some special ones like uh regular solids + + + align:start position:0% +some special ones like uh regular solids +they're only a few of them well + + align:start position:0% +they're only a few of them well + + + align:start position:0% +they're only a few of them well +similarly here except now we're in 4d + + align:start position:0% +similarly here except now we're in 4d + + + align:start position:0% +similarly here except now we're in 4d +and the corresponding things are + + align:start position:0% +and the corresponding things are + + + align:start position:0% +and the corresponding things are +rotations rather than polyhedra and so + + align:start position:0% +rotations rather than polyhedra and so + + + align:start position:0% +rotations rather than polyhedra and so +it turns out that if you look at the + + align:start position:0% +it turns out that if you look at the + + + align:start position:0% +it turns out that if you look at the +rotations of polyhedra they will give + + align:start position:0% +rotations of polyhedra they will give + + + align:start position:0% +rotations of polyhedra they will give +you a nice even sampling of that space + + align:start position:0% +you a nice even sampling of that space + + + align:start position:0% +you a nice even sampling of that space +and the rotation groups are the so the + + align:start position:0% +and the rotation groups are the so the + + + align:start position:0% +and the rotation groups are the so the +tetrahedron + + align:start position:0% +tetrahedron + + + align:start position:0% +tetrahedron +has 12 rotations that will align it with + + align:start position:0% +has 12 rotations that will align it with + + + align:start position:0% +has 12 rotations that will align it with +itself + + align:start position:0% +itself + + + align:start position:0% +itself +the cube and the octahedron have 24 + + align:start position:0% +the cube and the octahedron have 24 + + + align:start position:0% +the cube and the octahedron have 24 +and the icosahedron and dodecahedron + + align:start position:0% +and the icosahedron and dodecahedron + + + align:start position:0% +and the icosahedron and dodecahedron +have 60. so these give you a perfectly + + align:start position:0% +have 60. so these give you a perfectly + + + align:start position:0% +have 60. so these give you a perfectly +uniform spaced uh + + align:start position:0% +uniform spaced uh + + + align:start position:0% +uniform spaced uh +sampling of that space + + align:start position:0% +sampling of that space + + + align:start position:0% +sampling of that space +unfortunately that's not a very fine + + align:start position:0% +unfortunately that's not a very fine + + + align:start position:0% +unfortunately that's not a very fine +sampling right because 60 in the four + + align:start position:0% +sampling right because 60 in the four + + + align:start position:0% +sampling right because 60 in the four +dimensional space + + align:start position:0% +dimensional space + + + align:start position:0% +dimensional space +so they're tricks to give you + + align:start position:0% +so they're tricks to give you + + + align:start position:0% +so they're tricks to give you +a finer sampling but they all start with + + align:start position:0% +a finer sampling but they all start with + + + align:start position:0% +a finer sampling but they all start with +those simple ones and just uh while i + + align:start position:0% +those simple ones and just uh while i + + + align:start position:0% +those simple ones and just uh while i +have the slides here + + align:start position:0% +have the slides here + + + align:start position:0% +have the slides here +if you pick the + + align:start position:0% +if you pick the + + + align:start position:0% +if you pick the +coordinate systems right you get very + + align:start position:0% +coordinate systems right you get very + + + align:start position:0% +coordinate systems right you get very +simple expressions for these rotation + + align:start position:0% +simple expressions for these rotation + + + align:start position:0% +simple expressions for these rotation +groups so each of these is a rotation + + align:start position:0% +groups so each of these is a rotation + + + align:start position:0% +groups so each of these is a rotation +this one of course is the identity + + align:start position:0% +this one of course is the identity + + + align:start position:0% +this one of course is the identity +rotation does nothing + + align:start position:0% +rotation does nothing + + + align:start position:0% +rotation does nothing +this is the rotation about the x-axis + + align:start position:0% +this is the rotation about the x-axis + + + align:start position:0% +this is the rotation about the x-axis +by + + align:start position:0% +by + + + align:start position:0% +by +180 degrees + + align:start position:0% +180 degrees + + + align:start position:0% +180 degrees +and this is about the y-axis and so on + + align:start position:0% +and this is about the y-axis and so on + + + align:start position:0% +and this is about the y-axis and so on +so this is the group for the tetrahedron + + align:start position:0% +so this is the group for the tetrahedron + + + align:start position:0% +so this is the group for the tetrahedron +they provide a regular space + + align:start position:0% +they provide a regular space + + + align:start position:0% +they provide a regular space +sampling of that space this is for the + + align:start position:0% +sampling of that space this is for the + + + align:start position:0% +sampling of that space this is for the +hexahedron and the octahedron and then + + align:start position:0% +hexahedron and the octahedron and then + + + align:start position:0% +hexahedron and the octahedron and then +the + + align:start position:0% +the + + + align:start position:0% +the +the prize is this one this is the + + align:start position:0% +the prize is this one this is the + + + align:start position:0% +the prize is this one this is the +rotation group for the dodecahedron and + + align:start position:0% +rotation group for the dodecahedron and + + + align:start position:0% +rotation group for the dodecahedron and +icosahedron and where the you know + + align:start position:0% +icosahedron and where the you know + + + align:start position:0% +icosahedron and where the you know +these abcds are given by these + + align:start position:0% +these abcds are given by these + + + align:start position:0% +these abcds are given by these +expressions up there + + align:start position:0% +expressions up there + + + align:start position:0% +expressions up there +um these should look familiar + + align:start position:0% +um these should look familiar + + + align:start position:0% +um these should look familiar +um + + align:start position:0% +um + + + align:start position:0% +um +this only works if you line it up nicely + + align:start position:0% +this only works if you line it up nicely + + + align:start position:0% +this only works if you line it up nicely +with the coordinate system anyway + + align:start position:0% +with the coordinate system anyway + + + align:start position:0% +with the coordinate system anyway +you this would be a sampling so you + + align:start position:0% +you this would be a sampling so you + + + align:start position:0% +you this would be a sampling so you +could try these 60 + + align:start position:0% +could try these 60 + + + align:start position:0% +could try these 60 +orientations for + + align:start position:0% +orientations for + + + align:start position:0% +orientations for +your search or your averaging + + align:start position:0% +your search or your averaging + + + align:start position:0% +your search or your averaging +uh and then you can interpolate further + + align:start position:0% +uh and then you can interpolate further + + + align:start position:0% +uh and then you can interpolate further +okay well we've run out of time so + + align:start position:0% +okay well we've run out of time so + + + align:start position:0% +okay well we've run out of time so +that's it for today \ No newline at end of file diff --git a/v5jffYzm5pg.txt b/v5jffYzm5pg.txt new file mode 100644 index 0000000000000000000000000000000000000000..1dc4da1ecf6e80bdbe4473eb20cfa3977f08e0c5 --- /dev/null +++ b/v5jffYzm5pg.txt @@ -0,0 +1,1571 @@ +align:start position:0% + +welcome back to 820 special relativity + + align:start position:0% +welcome back to 820 special relativity + + + align:start position:0% +welcome back to 820 special relativity +so in our quest + + align:start position:0% +so in our quest + + + align:start position:0% +so in our quest +to understand how we get to general + + align:start position:0% +to understand how we get to general + + + align:start position:0% +to understand how we get to general +relativity there's two things to + + align:start position:0% +relativity there's two things to + + + align:start position:0% +relativity there's two things to +consider the first one this lecture is + + align:start position:0% +consider the first one this lecture is + + + align:start position:0% +consider the first one this lecture is +not meant to give you a full description + + align:start position:0% +not meant to give you a full description + + + align:start position:0% +not meant to give you a full description +of general relativity but just a view + + align:start position:0% +of general relativity but just a view + + + align:start position:0% +of general relativity but just a view +into where this might lead where this + + align:start position:0% +into where this might lead where this + + + align:start position:0% +into where this might lead where this +discussion might lead + + align:start position:0% +discussion might lead + + + align:start position:0% +discussion might lead +so + + align:start position:0% +so + + + align:start position:0% +so +in this quest + + align:start position:0% +in this quest + + + align:start position:0% +in this quest +we can understand the theory of + + align:start position:0% +we can understand the theory of + + + align:start position:0% +we can understand the theory of +general relativity as a theory on how to + + align:start position:0% +general relativity as a theory on how to + + + align:start position:0% +general relativity as a theory on how to +patch together the different reference + + align:start position:0% +patch together the different reference + + + align:start position:0% +patch together the different reference +frames which are each + + align:start position:0% +frames which are each + + + align:start position:0% +frames which are each +can be described in special relativity + + align:start position:0% +can be described in special relativity + + + align:start position:0% +can be described in special relativity +so in the framework we discussed up to + + align:start position:0% +so in the framework we discussed up to + + + align:start position:0% +so in the framework we discussed up to +now + + align:start position:0% +now + + + align:start position:0% +now +and is valid in short intervals in space + + align:start position:0% +and is valid in short intervals in space + + + align:start position:0% +and is valid in short intervals in space +time + + align:start position:0% +time + + + align:start position:0% +time +consequence of general relativity are + + align:start position:0% +consequence of general relativity are + + + align:start position:0% +consequence of general relativity are +that space time is curved so we have + + align:start position:0% +that space time is curved so we have + + + align:start position:0% +that space time is curved so we have +modified geometries + + align:start position:0% +modified geometries + + + align:start position:0% +modified geometries +um and we learned that because of + + align:start position:0% +um and we learned that because of + + + align:start position:0% +um and we learned that because of +gravitational effects matter curves + + align:start position:0% +gravitational effects matter curves + + + align:start position:0% +gravitational effects matter curves +space-time + + align:start position:0% +space-time + + + align:start position:0% +space-time +as a consequence of that you know there + + align:start position:0% +as a consequence of that you know there + + + align:start position:0% +as a consequence of that you know there +must be modification of of gravity based + + align:start position:0% +must be modification of of gravity based + + + align:start position:0% +must be modification of of gravity based +on meta distributions and so there must + + align:start position:0% +on meta distributions and so there must + + + align:start position:0% +on meta distributions and so there must +also be gravitational waves + + align:start position:0% +also be gravitational waves + + + align:start position:0% +also be gravitational waves +gravitational lenses which bend light + + align:start position:0% +gravitational lenses which bend light + + + align:start position:0% +gravitational lenses which bend light +black holes + + align:start position:0% +black holes + + + align:start position:0% +black holes +and there's cosmological predictions + + align:start position:0% +and there's cosmological predictions + + + align:start position:0% +and there's cosmological predictions +coming out of general relativity + + align:start position:0% +coming out of general relativity + + + align:start position:0% +coming out of general relativity +so let's have a discussion first + + align:start position:0% +so let's have a discussion first + + + align:start position:0% +so let's have a discussion first +what does it mean to have a changed or + + align:start position:0% +what does it mean to have a changed or + + + align:start position:0% +what does it mean to have a changed or +modified geometry + + align:start position:0% +modified geometry + + + align:start position:0% +modified geometry +what could that mean + + align:start position:0% +what could that mean + + + align:start position:0% +what could that mean +so you're all used to euclidean geometry + + align:start position:0% +so you're all used to euclidean geometry + + + align:start position:0% +so you're all used to euclidean geometry +where when you draw a + + align:start position:0% +where when you draw a + + + align:start position:0% +where when you draw a +triangle you add up all the angles to + + align:start position:0% +triangle you add up all the angles to + + + align:start position:0% +triangle you add up all the angles to +180 degrees if you draw two parallel + + align:start position:0% +180 degrees if you draw two parallel + + + align:start position:0% +180 degrees if you draw two parallel +lines they never cross they also don't + + align:start position:0% +lines they never cross they also don't + + + align:start position:0% +lines they never cross they also don't +diverge + + align:start position:0% +diverge + + + align:start position:0% +diverge +but if you have a modified geometry + + align:start position:0% +but if you have a modified geometry + + + align:start position:0% +but if you have a modified geometry +for example the geometry on the sphere + + align:start position:0% +for example the geometry on the sphere + + + align:start position:0% +for example the geometry on the sphere +like on our globe + + align:start position:0% +like on our globe + + + align:start position:0% +like on our globe +the angles do not add up to 180 degrees + + align:start position:0% +the angles do not add up to 180 degrees + + + align:start position:0% +the angles do not add up to 180 degrees +they actually the sum is larger than 180 + + align:start position:0% +they actually the sum is larger than 180 + + + align:start position:0% +they actually the sum is larger than 180 +degrees and parallel lines will cross we + + align:start position:0% +degrees and parallel lines will cross we + + + align:start position:0% +degrees and parallel lines will cross we +would call this kind of space positively + + align:start position:0% +would call this kind of space positively + + + align:start position:0% +would call this kind of space positively +curved + + align:start position:0% +curved + + + align:start position:0% +curved +but you can have the opposite example + + align:start position:0% +but you can have the opposite example + + + align:start position:0% +but you can have the opposite example +like on a saddle + + align:start position:0% +like on a saddle + + + align:start position:0% +like on a saddle +so you can have other spaces and other + + align:start position:0% +so you can have other spaces and other + + + align:start position:0% +so you can have other spaces and other +curved spaces and they can be negatively + + align:start position:0% +curved spaces and they can be negatively + + + align:start position:0% +curved spaces and they can be negatively +skirved in this example if you add up + + align:start position:0% +skirved in this example if you add up + + + align:start position:0% +skirved in this example if you add up +all angles you find they add up to less + + align:start position:0% +all angles you find they add up to less + + + align:start position:0% +all angles you find they add up to less +than 180 degrees + + align:start position:0% +than 180 degrees + + + align:start position:0% +than 180 degrees +parallel lines will not cross but they + + align:start position:0% +parallel lines will not cross but they + + + align:start position:0% +parallel lines will not cross but they +will diverge + + align:start position:0% + + + + align:start position:0% + +okay so + + align:start position:0% +okay so + + + align:start position:0% +okay so +mass has changed the geometry of + + align:start position:0% +mass has changed the geometry of + + + align:start position:0% +mass has changed the geometry of +spacecraft time you know we just talked + + align:start position:0% +spacecraft time you know we just talked + + + align:start position:0% +spacecraft time you know we just talked +about light bending + + align:start position:0% +about light bending + + + align:start position:0% +about light bending +and because of the change in geometry + + align:start position:0% +and because of the change in geometry + + + align:start position:0% +and because of the change in geometry +light will not go on a straight line + + align:start position:0% +light will not go on a straight line + + + align:start position:0% +light will not go on a straight line +anymore but will bend around massive + + align:start position:0% +anymore but will bend around massive + + + align:start position:0% +anymore but will bend around massive +object space time is + + align:start position:0% +object space time is + + + align:start position:0% +object space time is +curved geometry of space-time tells us + + align:start position:0% +curved geometry of space-time tells us + + + align:start position:0% +curved geometry of space-time tells us +how the masses move + + align:start position:0% +how the masses move + + + align:start position:0% +how the masses move +you can think about + + align:start position:0% +you can think about + + + align:start position:0% +you can think about +um a trampoline when you put a heavy + + align:start position:0% +um a trampoline when you put a heavy + + + align:start position:0% +um a trampoline when you put a heavy +object on a trampoline + + align:start position:0% +object on a trampoline + + + align:start position:0% +object on a trampoline +all the other objects on the trampoline + + align:start position:0% +all the other objects on the trampoline + + + align:start position:0% +all the other objects on the trampoline +will gravitate towards the heavier + + align:start position:0% +will gravitate towards the heavier + + + align:start position:0% +will gravitate towards the heavier +object and that's kind of a picture on + + align:start position:0% +object and that's kind of a picture on + + + align:start position:0% +object and that's kind of a picture on +how spacecraft spacetime actually looks + + align:start position:0% +how spacecraft spacetime actually looks + + + align:start position:0% +how spacecraft spacetime actually looks +like + + align:start position:0% + + + + align:start position:0% + +einstein + + align:start position:0% +einstein + + + align:start position:0% +einstein +used those finding in order to redefine + + align:start position:0% +used those finding in order to redefine + + + align:start position:0% +used those finding in order to redefine +newton's first law and found the + + align:start position:0% +newton's first law and found the + + + align:start position:0% +newton's first law and found the +so-called einstein field equation + + align:start position:0% +so-called einstein field equation + + + align:start position:0% +so-called einstein field equation +so there's on one side of the equation + + align:start position:0% +so there's on one side of the equation + + + align:start position:0% +so there's on one side of the equation +there's a description of space time and + + align:start position:0% +there's a description of space time and + + + align:start position:0% +there's a description of space time and +its curvature + + align:start position:0% +its curvature + + + align:start position:0% +its curvature +and on the other side of the equation is + + align:start position:0% +and on the other side of the equation is + + + align:start position:0% +and on the other side of the equation is +the energy momentum momentum tensor the + + align:start position:0% +the energy momentum momentum tensor the + + + align:start position:0% +the energy momentum momentum tensor the +description and how energy energy and + + align:start position:0% +description and how energy energy and + + + align:start position:0% +description and how energy energy and +momentum of object is distributed + + align:start position:0% +momentum of object is distributed + + + align:start position:0% +momentum of object is distributed +and those two things space time and + + align:start position:0% +and those two things space time and + + + align:start position:0% +and those two things space time and +energy and momentum they're kind of + + align:start position:0% +energy and momentum they're kind of + + + align:start position:0% +energy and momentum they're kind of +interlinked in this in this equation + + align:start position:0% +interlinked in this in this equation + + + align:start position:0% +interlinked in this in this equation +so if you read this description you can + + align:start position:0% +so if you read this description you can + + + align:start position:0% +so if you read this description you can +read it from one side to the next space + + align:start position:0% +read it from one side to the next space + + + align:start position:0% +read it from one side to the next space +time tells matter how to move + + align:start position:0% +time tells matter how to move + + + align:start position:0% +time tells matter how to move +or you read it from the other direction + + align:start position:0% +or you read it from the other direction + + + align:start position:0% +or you read it from the other direction +say + + align:start position:0% +say + + + align:start position:0% +say +meta tell space crime space time how to + + align:start position:0% +meta tell space crime space time how to + + + align:start position:0% +meta tell space crime space time how to +curve + + align:start position:0% +curve + + + align:start position:0% +curve +there is an equation and you can just + + align:start position:0% +there is an equation and you can just + + + align:start position:0% +there is an equation and you can just +read it from the left to the right or + + align:start position:0% +read it from the left to the right or + + + align:start position:0% +read it from the left to the right or +from the right to the left so our + + align:start position:0% +from the right to the left so our + + + align:start position:0% +from the right to the left so our +understanding here + + align:start position:0% +understanding here + + + align:start position:0% +understanding here +it says space and time are not fixed + + align:start position:0% +it says space and time are not fixed + + + align:start position:0% +it says space and time are not fixed +things + + align:start position:0% +things + + + align:start position:0% +things +you know + + align:start position:0% +you know + + + align:start position:0% +you know +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +matter + + align:start position:0% +matter + + + align:start position:0% +matter +through which matter and energy moves + + align:start position:0% +through which matter and energy moves + + + align:start position:0% +through which matter and energy moves +through + + align:start position:0% +through + + + align:start position:0% +through +the matter and energy then itself + + align:start position:0% +the matter and energy then itself + + + align:start position:0% +the matter and energy then itself +defines space-time + + align:start position:0% +defines space-time + + + align:start position:0% +defines space-time +and matter because of that time sp + + align:start position:0% +and matter because of that time sp + + + align:start position:0% +and matter because of that time sp +space-time is dynamical it's changing + + align:start position:0% +space-time is dynamical it's changing + + + align:start position:0% +space-time is dynamical it's changing +it's interacting with the matter and + + align:start position:0% +it's interacting with the matter and + + + align:start position:0% +it's interacting with the matter and +with the energy + + align:start position:0% +with the energy + + + align:start position:0% +with the energy +this is a super exciting picture from + + align:start position:0% +this is a super exciting picture from + + + align:start position:0% +this is a super exciting picture from +hubble + + align:start position:0% +hubble + + + align:start position:0% +hubble +the hubble space telescope and you see + + align:start position:0% +the hubble space telescope and you see + + + align:start position:0% +the hubble space telescope and you see +galaxies um but what you also see + + align:start position:0% +galaxies um but what you also see + + + align:start position:0% +galaxies um but what you also see +is those structures which looked like + + align:start position:0% +is those structures which looked like + + + align:start position:0% +is those structures which looked like +something the light has gone through + + align:start position:0% +something the light has gone through + + + align:start position:0% +something the light has gone through +lenses those lenses are actually meta + + align:start position:0% +lenses those lenses are actually meta + + + align:start position:0% +lenses those lenses are actually meta +distributions galaxies themselves which + + align:start position:0% +distributions galaxies themselves which + + + align:start position:0% +distributions galaxies themselves which +actually lead to the bending of the + + align:start position:0% +actually lead to the bending of the + + + align:start position:0% +actually lead to the bending of the +light and those lensing effects + + align:start position:0% + + + + align:start position:0% + +okay if you want to summarize um general + + align:start position:0% +okay if you want to summarize um general + + + align:start position:0% +okay if you want to summarize um general +relativity you can first say that space + + align:start position:0% +relativity you can first say that space + + + align:start position:0% +relativity you can first say that space +time is curved and it follows the pseudo + + align:start position:0% +time is curved and it follows the pseudo + + + align:start position:0% +time is curved and it follows the pseudo +romanian monifold with a specific metric + + align:start position:0% +romanian monifold with a specific metric + + + align:start position:0% +romanian monifold with a specific metric +we have seen the metric before with + + align:start position:0% +we have seen the metric before with + + + align:start position:0% +we have seen the metric before with +minus plus plus plus + + align:start position:0% +minus plus plus plus + + + align:start position:0% +minus plus plus plus +and the relationship between matter and + + align:start position:0% +and the relationship between matter and + + + align:start position:0% +and the relationship between matter and +curvature is given by the einstein + + align:start position:0% +curvature is given by the einstein + + + align:start position:0% +curvature is given by the einstein +equation and here i give you a slightly + + align:start position:0% +equation and here i give you a slightly + + + align:start position:0% +equation and here i give you a slightly +different form where there is the + + align:start position:0% +different form where there is the + + + align:start position:0% +different form where there is the +dynamics again on one side and the + + align:start position:0% +dynamics again on one side and the + + + align:start position:0% +dynamics again on one side and the +energy momentum on the other side + + align:start position:0% +energy momentum on the other side + + + align:start position:0% +energy momentum on the other side +let's just look at one + + align:start position:0% +let's just look at one + + + align:start position:0% +let's just look at one +example here so we discussed in special + + align:start position:0% +example here so we discussed in special + + + align:start position:0% +example here so we discussed in special +relativity invariant intervals right and + + align:start position:0% +relativity invariant intervals right and + + + align:start position:0% +relativity invariant intervals right and +we had this delta s squared or we had + + align:start position:0% +we had this delta s squared or we had + + + align:start position:0% +we had this delta s squared or we had +different name for i + + align:start position:0% +different name for i + + + align:start position:0% +different name for i +given by minus dt square plus dx square + + align:start position:0% +given by minus dt square plus dx square + + + align:start position:0% +given by minus dt square plus dx square +plus dy square plus dz squared we could + + align:start position:0% +plus dy square plus dz squared we could + + + align:start position:0% +plus dy square plus dz squared we could +have just written this in polar + + align:start position:0% +have just written this in polar + + + align:start position:0% +have just written this in polar +coordinates as well where you find the d + + align:start position:0% +coordinates as well where you find the d + + + align:start position:0% +coordinates as well where you find the d +r square and r square d theta square and + + align:start position:0% +r square and r square d theta square and + + + align:start position:0% +r square and r square d theta square and +then r square + + align:start position:0% +then r square + + + align:start position:0% +then r square +sine square theta d phi squared + + align:start position:0% +sine square theta d phi squared + + + align:start position:0% +sine square theta d phi squared +okay same thing it's just a different + + align:start position:0% +okay same thing it's just a different + + + align:start position:0% +okay same thing it's just a different +coordinate system + + align:start position:0% +coordinate system + + + align:start position:0% +coordinate system +so + + align:start position:0% +so + + + align:start position:0% +so +as a solution + + align:start position:0% +as a solution + + + align:start position:0% +as a solution +to einstein equation we find something + + align:start position:0% +to einstein equation we find something + + + align:start position:0% +to einstein equation we find something +which looks very very similar that's not + + align:start position:0% +which looks very very similar that's not + + + align:start position:0% +which looks very very similar that's not +a surprise as we + + align:start position:0% +a surprise as we + + + align:start position:0% +a surprise as we +find general relativity as a patchwork + + align:start position:0% +find general relativity as a patchwork + + + align:start position:0% +find general relativity as a patchwork +of small spaces of general special + + align:start position:0% +of small spaces of general special + + + align:start position:0% +of small spaces of general special +relativity + + align:start position:0% +relativity + + + align:start position:0% +relativity +so the solutions might be very similar + + align:start position:0% +so the solutions might be very similar + + + align:start position:0% +so the solutions might be very similar +okay in the solution found here by the + + align:start position:0% +okay in the solution found here by the + + + align:start position:0% +okay in the solution found here by the +so-called schwarzschild solution which + + align:start position:0% +so-called schwarzschild solution which + + + align:start position:0% +so-called schwarzschild solution which +are unique solution vacuum with + + align:start position:0% +are unique solution vacuum with + + + align:start position:0% +are unique solution vacuum with +spherical symmetry + + align:start position:0% +spherical symmetry + + + align:start position:0% +spherical symmetry +of a meta distribution so you have a + + align:start position:0% +of a meta distribution so you have a + + + align:start position:0% +of a meta distribution so you have a +spherical meta distribution like our sun + + align:start position:0% +spherical meta distribution like our sun + + + align:start position:0% +spherical meta distribution like our sun +right and this is solution which + + align:start position:0% +right and this is solution which + + + align:start position:0% +right and this is solution which +describes + + align:start position:0% +describes + + + align:start position:0% +describes +um space time around this you find this + + align:start position:0% +um space time around this you find this + + + align:start position:0% +um space time around this you find this +invariant interval here has two + + align:start position:0% +invariant interval here has two + + + align:start position:0% +invariant interval here has two +interesting features + + align:start position:0% +interesting features + + + align:start position:0% +interesting features +there's two + + align:start position:0% +there's two + + + align:start position:0% +there's two +singularities in here + + align:start position:0% +singularities in here + + + align:start position:0% +singularities in here +so you find this should be a minus one + + align:start position:0% + + + + align:start position:0% + +you find those two singularities one is + + align:start position:0% +you find those two singularities one is + + + align:start position:0% +you find those two singularities one is +at r equals zero that's kind of expected + + align:start position:0% +at r equals zero that's kind of expected + + + align:start position:0% +at r equals zero that's kind of expected +in the middle of the mass distribution + + align:start position:0% +in the middle of the mass distribution + + + align:start position:0% +in the middle of the mass distribution +this thing is not defined anymore + + align:start position:0% +this thing is not defined anymore + + + align:start position:0% +this thing is not defined anymore +there's no mass left + + align:start position:0% +there's no mass left + + + align:start position:0% +there's no mass left +but there's also a second singularity at + + align:start position:0% +but there's also a second singularity at + + + align:start position:0% +but there's also a second singularity at +two gm + + align:start position:0% +two gm + + + align:start position:0% +two gm +this is called the so-called + + align:start position:0% +this is called the so-called + + + align:start position:0% +this is called the so-called +schwarzschild radius + + align:start position:0% +schwarzschild radius + + + align:start position:0% +schwarzschild radius +and it defines + + align:start position:0% +and it defines + + + align:start position:0% +and it defines +if you get to the singularity + + align:start position:0% +if you get to the singularity + + + align:start position:0% +if you get to the singularity +you basically don't define anymore this + + align:start position:0% +you basically don't define anymore this + + + align:start position:0% +you basically don't define anymore this +invariant interval + + align:start position:0% +invariant interval + + + align:start position:0% +invariant interval +you can think about the black hole the + + align:start position:0% +you can think about the black hole the + + + align:start position:0% +you can think about the black hole the +surface of a black hole as this + + align:start position:0% +surface of a black hole as this + + + align:start position:0% +surface of a black hole as this +singularity + + align:start position:0% +singularity + + + align:start position:0% +singularity +at this r values at those singularities + + align:start position:0% +at this r values at those singularities + + + align:start position:0% +at this r values at those singularities +everything becomes timeline time like or + + align:start position:0% +everything becomes timeline time like or + + + align:start position:0% +everything becomes timeline time like or +everything within the radius becomes + + align:start position:0% +everything within the radius becomes + + + align:start position:0% +everything within the radius becomes +time-like + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/vICUY43i190.txt b/vICUY43i190.txt new file mode 100644 index 0000000000000000000000000000000000000000..0e6186de50ecf39cf5ff5327c7ce09ad97aff95c --- /dev/null +++ b/vICUY43i190.txt @@ -0,0 +1,1939 @@ +align:start position:0% + +welcome back to 8701 + + align:start position:0% +welcome back to 8701 + + + align:start position:0% +welcome back to 8701 +so in this lecture we look at the + + align:start position:0% +so in this lecture we look at the + + + align:start position:0% +so in this lecture we look at the +interaction of w + + align:start position:0% +interaction of w + + + align:start position:0% +interaction of w +codons with quarks so the charged weak + + align:start position:0% +codons with quarks so the charged weak + + + align:start position:0% +codons with quarks so the charged weak +interaction of quarks + + align:start position:0% +interaction of quarks + + + align:start position:0% +interaction of quarks +let's just make a number of observations + + align:start position:0% +let's just make a number of observations + + + align:start position:0% +let's just make a number of observations +so we observe that the weak interaction + + align:start position:0% +so we observe that the weak interaction + + + align:start position:0% +so we observe that the weak interaction +respects the lepton generation + + align:start position:0% +respects the lepton generation + + + align:start position:0% +respects the lepton generation +meaning that a w couples to an electron + + align:start position:0% +meaning that a w couples to an electron + + + align:start position:0% +meaning that a w couples to an electron +and an electro neutrino + + align:start position:0% +and an electro neutrino + + + align:start position:0% +and an electro neutrino +but not an electron in the mirena too + + align:start position:0% +but not an electron in the mirena too + + + align:start position:0% +but not an electron in the mirena too +but + + align:start position:0% +but + + + align:start position:0% +but +in the case of the quarks there is a + + align:start position:0% +in the case of the quarks there is a + + + align:start position:0% +in the case of the quarks there is a +violation of this + + align:start position:0% +violation of this + + + align:start position:0% +violation of this +so there is a disrespect of the clock + + align:start position:0% +so there is a disrespect of the clock + + + align:start position:0% +so there is a disrespect of the clock +generation + + align:start position:0% +generation + + + align:start position:0% +generation +when it comes to the interaction with ws + + align:start position:0% +when it comes to the interaction with ws + + + align:start position:0% +when it comes to the interaction with ws +so when you investigate these two + + align:start position:0% +so when you investigate these two + + + align:start position:0% +so when you investigate these two +diagrams here you find that the w + + align:start position:0% +diagrams here you find that the w + + + align:start position:0% +diagrams here you find that the w +couples couples to the u-quark but to + + align:start position:0% +couples couples to the u-quark but to + + + align:start position:0% +couples couples to the u-quark but to +the b quark and the u-quark but it also + + align:start position:0% +the b quark and the u-quark but it also + + + align:start position:0% +the b quark and the u-quark but it also +couples to the s-code + + align:start position:0% +couples to the s-code + + + align:start position:0% +couples to the s-code +s clock in the youth block all right + + align:start position:0% +s clock in the youth block all right + + + align:start position:0% +s clock in the youth block all right +um in order to encapsulate this we have + + align:start position:0% +um in order to encapsulate this we have + + + align:start position:0% +um in order to encapsulate this we have +to make a correction and the corrections + + align:start position:0% +to make a correction and the corrections + + + align:start position:0% +to make a correction and the corrections +are typically called + + align:start position:0% +are typically called + + + align:start position:0% +are typically called +cosine um theta c and sine theta c + + align:start position:0% +cosine um theta c and sine theta c + + + align:start position:0% +cosine um theta c and sine theta c +theta c is a cabinet angle so theta + + align:start position:0% +theta c is a cabinet angle so theta + + + align:start position:0% +theta c is a cabinet angle so theta +cable + + align:start position:0% +cable + + + align:start position:0% +cable +turns out this is rather small certain + + align:start position:0% +turns out this is rather small certain + + + align:start position:0% +turns out this is rather small certain +decrease so it is a correction of small + + align:start position:0% +decrease so it is a correction of small + + + align:start position:0% +decrease so it is a correction of small +correction when we study the + + align:start position:0% +correction when we study the + + + align:start position:0% +correction when we study the +partial decay with of the k on that in + + align:start position:0% +partial decay with of the k on that in + + + align:start position:0% +partial decay with of the k on that in +electronic decays + + align:start position:0% +electronic decays + + + align:start position:0% +electronic decays +um was a partial decays to the ion of + + align:start position:0% +um was a partial decays to the ion of + + + align:start position:0% +um was a partial decays to the ion of +the occupier in electronic decays + + align:start position:0% +the occupier in electronic decays + + + align:start position:0% +the occupier in electronic decays +we found that there is a set of forms + + align:start position:0% +we found that there is a set of forms + + + align:start position:0% +we found that there is a set of forms +that was a form factor for the pi and + + align:start position:0% +that was a form factor for the pi and + + + align:start position:0% +that was a form factor for the pi and +decay and a form factor for the k on + + align:start position:0% +decay and a form factor for the k on + + + align:start position:0% +decay and a form factor for the k on +decay + + align:start position:0% +decay + + + align:start position:0% +decay +it turns out that the form factors are + + align:start position:0% +it turns out that the form factors are + + + align:start position:0% +it turns out that the form factors are +due to + + align:start position:0% +due to + + + align:start position:0% +due to +this additional correction so you find + + align:start position:0% +this additional correction so you find + + + align:start position:0% +this additional correction so you find +the tangent square of the carbido angle + + align:start position:0% +the tangent square of the carbido angle + + + align:start position:0% +the tangent square of the carbido angle +as part of this correction good + + align:start position:0% +as part of this correction good + + + align:start position:0% +as part of this correction good +so far so good now we have made an + + align:start position:0% +so far so good now we have made an + + + align:start position:0% +so far so good now we have made an +observation we haven't explained + + align:start position:0% +observation we haven't explained + + + align:start position:0% +observation we haven't explained +anything yet + + align:start position:0% +anything yet + + + align:start position:0% +anything yet +you can make one more um observation or + + align:start position:0% +you can make one more um observation or + + + align:start position:0% +you can make one more um observation or +discuss + + align:start position:0% +discuss + + + align:start position:0% +discuss +one and that's the decay of neutral + + align:start position:0% +one and that's the decay of neutral + + + align:start position:0% +one and that's the decay of neutral +chaons to a pair of neurons it turns out + + align:start position:0% +chaons to a pair of neurons it turns out + + + align:start position:0% +chaons to a pair of neurons it turns out +that + + align:start position:0% +that + + + align:start position:0% +that +those are not very likely + + align:start position:0% +those are not very likely + + + align:start position:0% +those are not very likely +even so you would expect that the + + align:start position:0% +even so you would expect that the + + + align:start position:0% +even so you would expect that the +amplitude has a factor here + + align:start position:0% +amplitude has a factor here + + + align:start position:0% +amplitude has a factor here +of um sine and cosine tabito + + align:start position:0% +of um sine and cosine tabito + + + align:start position:0% +of um sine and cosine tabito +so the amplitude should be in the order + + align:start position:0% +so the amplitude should be in the order + + + align:start position:0% +so the amplitude should be in the order +of sine + + align:start position:0% +of sine + + + align:start position:0% +of sine +theta carbido times cosine theta + + align:start position:0% +theta carbido times cosine theta + + + align:start position:0% +theta carbido times cosine theta +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +um so when this was studied the charm + + align:start position:0% +um so when this was studied the charm + + + align:start position:0% +um so when this was studied the charm +clock hasn't been discovered + + align:start position:0% +clock hasn't been discovered + + + align:start position:0% +clock hasn't been discovered +um and the explanation to why + + align:start position:0% +um and the explanation to why + + + align:start position:0% +um and the explanation to why +uh this decay is suppressed comes from + + align:start position:0% +uh this decay is suppressed comes from + + + align:start position:0% +uh this decay is suppressed comes from +the fact that there is a second diagram + + align:start position:0% +the fact that there is a second diagram + + + align:start position:0% +the fact that there is a second diagram +here + + align:start position:0% +here + + + align:start position:0% +here +where we just replace the u chord in + + align:start position:0% +where we just replace the u chord in + + + align:start position:0% +where we just replace the u chord in +this loop as a c clock + + align:start position:0% +this loop as a c clock + + + align:start position:0% +this loop as a c clock +this diagram contributes as a minus sign + + align:start position:0% +this diagram contributes as a minus sign + + + align:start position:0% +this diagram contributes as a minus sign +to the amplitude and therefore those two + + align:start position:0% +to the amplitude and therefore those two + + + align:start position:0% +to the amplitude and therefore those two +diagrams they cancel + + align:start position:0% +diagrams they cancel + + + align:start position:0% +diagrams they cancel +right yeah they are the same magnitude + + align:start position:0% +right yeah they are the same magnitude + + + align:start position:0% +right yeah they are the same magnitude +about the same magnitude and we have an + + align:start position:0% +about the same magnitude and we have an + + + align:start position:0% +about the same magnitude and we have an +opposite side + + align:start position:0% +opposite side + + + align:start position:0% +opposite side +so this was the first indication that + + align:start position:0% +so this was the first indication that + + + align:start position:0% +so this was the first indication that +there must be a fourth quark + + align:start position:0% +there must be a fourth quark + + + align:start position:0% +there must be a fourth quark +contributing to this kind of processes + + align:start position:0% +contributing to this kind of processes + + + align:start position:0% +contributing to this kind of processes +the charm block + + align:start position:0% +the charm block + + + align:start position:0% +the charm block +um let me now try to understand what's + + align:start position:0% +um let me now try to understand what's + + + align:start position:0% +um let me now try to understand what's +going on here why is the w + + align:start position:0% +going on here why is the w + + + align:start position:0% +going on here why is the w +uh coupling modified um or why + + align:start position:0% +uh coupling modified um or why + + + align:start position:0% +uh coupling modified um or why +it's not the full down quark or + + align:start position:0% +it's not the full down quark or + + + align:start position:0% +it's not the full down quark or +a strange core participating in the weak + + align:start position:0% +a strange core participating in the weak + + + align:start position:0% +a strange core participating in the weak +interaction + + align:start position:0% +interaction + + + align:start position:0% +interaction +um we can do the following here we can + + align:start position:0% +um we can do the following here we can + + + align:start position:0% +um we can do the following here we can +rewrite + + align:start position:0% +rewrite + + + align:start position:0% +rewrite +or we note that the the weak interaction + + align:start position:0% +or we note that the the weak interaction + + + align:start position:0% +or we note that the the weak interaction +eigenstate the eigenstate which + + align:start position:0% +eigenstate the eigenstate which + + + align:start position:0% +eigenstate the eigenstate which +participate in the weak index is not the + + align:start position:0% +participate in the weak index is not the + + + align:start position:0% +participate in the weak index is not the +eigenstate of the particle itself the + + align:start position:0% +eigenstate of the particle itself the + + + align:start position:0% +eigenstate of the particle itself the +so-called mass eigenstate + + align:start position:0% +so-called mass eigenstate + + + align:start position:0% +so-called mass eigenstate +so we have to write the weak eigenstate + + align:start position:0% +so we have to write the weak eigenstate + + + align:start position:0% +so we have to write the weak eigenstate +with a linear combination of the + + align:start position:0% +with a linear combination of the + + + align:start position:0% +with a linear combination of the +the mass eigenstate or white version + + align:start position:0% +the mass eigenstate or white version + + + align:start position:0% +the mass eigenstate or white version +this can be done + + align:start position:0% +this can be done + + + align:start position:0% +this can be done +in this matrix form here where we simply + + align:start position:0% +in this matrix form here where we simply + + + align:start position:0% +in this matrix form here where we simply +modify + + align:start position:0% +modify + + + align:start position:0% +modify +multiply the weak eigenstates + + align:start position:0% +multiply the weak eigenstates + + + align:start position:0% +multiply the weak eigenstates +with the with a matrix and just + + align:start position:0% +with the with a matrix and just + + + align:start position:0% +with the with a matrix and just +basically rotate it + + align:start position:0% +basically rotate it + + + align:start position:0% +basically rotate it +into the mass eigenstate so this was + + align:start position:0% +into the mass eigenstate so this was + + + align:start position:0% +into the mass eigenstate so this was +proposed by gabibo and rather successful + + align:start position:0% +proposed by gabibo and rather successful + + + align:start position:0% +proposed by gabibo and rather successful +um but it didn't incorporate the search + + align:start position:0% +um but it didn't incorporate the search + + + align:start position:0% +um but it didn't incorporate the search +innovation articles and this was done by + + align:start position:0% +innovation articles and this was done by + + + align:start position:0% +innovation articles and this was done by +kobayashi and mascara who generalized + + align:start position:0% +kobayashi and mascara who generalized + + + align:start position:0% +kobayashi and mascara who generalized +the scheme + + align:start position:0% +the scheme + + + align:start position:0% +the scheme +and propose the so-called ckm matrix c + + align:start position:0% +and propose the so-called ckm matrix c + + + align:start position:0% +and propose the so-called ckm matrix c +is here for + + align:start position:0% +is here for + + + align:start position:0% +is here for +cabibo kobayashi and mascara + + align:start position:0% +cabibo kobayashi and mascara + + + align:start position:0% +cabibo kobayashi and mascara +because of constraints we'll discuss in + + align:start position:0% +because of constraints we'll discuss in + + + align:start position:0% +because of constraints we'll discuss in +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +in one of the recitations um this matrix + + align:start position:0% +in one of the recitations um this matrix + + + align:start position:0% +in one of the recitations um this matrix +can be parameterized or has only + + align:start position:0% +can be parameterized or has only + + + align:start position:0% +can be parameterized or has only +three independent angles and one complex + + align:start position:0% +three independent angles and one complex + + + align:start position:0% +three independent angles and one complex +space as independent parameters + + align:start position:0% +space as independent parameters + + + align:start position:0% +space as independent parameters +so you can choose different + + align:start position:0% +so you can choose different + + + align:start position:0% +so you can choose different +parameterization to capture that there's + + align:start position:0% +parameterization to capture that there's + + + align:start position:0% +parameterization to capture that there's +only three + + align:start position:0% +only three + + + align:start position:0% +only three +four parameters in this matrix which has + + align:start position:0% +four parameters in this matrix which has + + + align:start position:0% +four parameters in this matrix which has +nine components um one is + + align:start position:0% +nine components um one is + + + align:start position:0% +nine components um one is +by uh thinking about this matrix as + + align:start position:0% +by uh thinking about this matrix as + + + align:start position:0% +by uh thinking about this matrix as +three independent rotations in this + + align:start position:0% +three independent rotations in this + + + align:start position:0% +three independent rotations in this +complex space here + + align:start position:0% +complex space here + + + align:start position:0% +complex space here +in terms of numerical values you see + + align:start position:0% +in terms of numerical values you see + + + align:start position:0% +in terms of numerical values you see +that the + + align:start position:0% + + + + align:start position:0% + +diagonal elements of this matrix are + + align:start position:0% +diagonal elements of this matrix are + + + align:start position:0% +diagonal elements of this matrix are +very close to one + + align:start position:0% +very close to one + + + align:start position:0% +very close to one +meaning that this this mixing is + + align:start position:0% +meaning that this this mixing is + + + align:start position:0% +meaning that this this mixing is +for in the dwark sector the wireless + + align:start position:0% +for in the dwark sector the wireless + + + align:start position:0% +for in the dwark sector the wireless +mount effect you find that those next + + align:start position:0% +mount effect you find that those next + + + align:start position:0% +mount effect you find that those next +nearest + + align:start position:0% +nearest + + + align:start position:0% +nearest +off diagonal elements and the order of + + align:start position:0% +off diagonal elements and the order of + + + align:start position:0% +off diagonal elements and the order of +20 percent + + align:start position:0% +20 percent + + + align:start position:0% +20 percent +and the next to next of elements are + + align:start position:0% +and the next to next of elements are + + + align:start position:0% +and the next to next of elements are +even + + align:start position:0% +even + + + align:start position:0% +even +smaller okay this leads us + + align:start position:0% +smaller okay this leads us + + + align:start position:0% +smaller okay this leads us +into the discussion that we can you know + + align:start position:0% +into the discussion that we can you know + + + align:start position:0% +into the discussion that we can you know +use different parameterization in order + + align:start position:0% +use different parameterization in order + + + align:start position:0% +use different parameterization in order +to capture + + align:start position:0% +to capture + + + align:start position:0% +to capture +we already discussed the standard + + align:start position:0% +we already discussed the standard + + + align:start position:0% +we already discussed the standard +parameterization which you can really + + align:start position:0% +parameterization which you can really + + + align:start position:0% +parameterization which you can really +think about + + align:start position:0% +think about + + + align:start position:0% +think about +three different rotations um and the + + align:start position:0% +three different rotations um and the + + + align:start position:0% +three different rotations um and the +the values of this those angles are + + align:start position:0% +the values of this those angles are + + + align:start position:0% +the values of this those angles are +given here + + align:start position:0% +given here + + + align:start position:0% +given here +together with the value of this um + + align:start position:0% +together with the value of this um + + + align:start position:0% +together with the value of this um +additional phase + + align:start position:0% +additional phase + + + align:start position:0% +additional phase +another way to look at this is the + + align:start position:0% +another way to look at this is the + + + align:start position:0% +another way to look at this is the +so-called wolfenstein polarization and + + align:start position:0% +so-called wolfenstein polarization and + + + align:start position:0% +so-called wolfenstein polarization and +this captures the fact that it seems + + align:start position:0% +this captures the fact that it seems + + + align:start position:0% +this captures the fact that it seems +like that there is a + + align:start position:0% +like that there is a + + + align:start position:0% +like that there is a +correction being applied to the actual + + align:start position:0% +correction being applied to the actual + + + align:start position:0% +correction being applied to the actual +particle so you find + + align:start position:0% +particle so you find + + + align:start position:0% +particle so you find +elements the order of lambda lambda is + + align:start position:0% +elements the order of lambda lambda is + + + align:start position:0% +elements the order of lambda lambda is +about 22 + + align:start position:0% +about 22 + + + align:start position:0% +about 22 +um then you find elements which are in + + align:start position:0% +um then you find elements which are in + + + align:start position:0% +um then you find elements which are in +the order of one minus + + align:start position:0% +the order of one minus + + + align:start position:0% +the order of one minus +the lambda square correction and then + + align:start position:0% +the lambda square correction and then + + + align:start position:0% +the lambda square correction and then +there's elements which are of lambda + + align:start position:0% +there's elements which are of lambda + + + align:start position:0% +there's elements which are of lambda +square and lambda + + align:start position:0% +square and lambda + + + align:start position:0% +square and lambda +third power so this captures + + align:start position:0% +third power so this captures + + + align:start position:0% +third power so this captures +the matrix and then there's higher order + + align:start position:0% +the matrix and then there's higher order + + + align:start position:0% +the matrix and then there's higher order +corrections to that + + align:start position:0% +corrections to that + + + align:start position:0% +corrections to that +which are of order lambda to the fourth + + align:start position:0% +which are of order lambda to the fourth + + + align:start position:0% +which are of order lambda to the fourth +power + + align:start position:0% +power + + + align:start position:0% +power +okay + + align:start position:0% + + + + align:start position:0% + +um because there's constraints on this + + align:start position:0% +um because there's constraints on this + + + align:start position:0% +um because there's constraints on this +matrix + + align:start position:0% +matrix + + + align:start position:0% +matrix +specifically your unitarity constraints + + align:start position:0% +specifically your unitarity constraints + + + align:start position:0% +specifically your unitarity constraints +meaning that + + align:start position:0% +meaning that + + + align:start position:0% +meaning that +you know we have three generations if i + + align:start position:0% +you know we have three generations if i + + + align:start position:0% +you know we have three generations if i +make a mixing of those three + + align:start position:0% +make a mixing of those three + + + align:start position:0% +make a mixing of those three +uh mass eigenstate to a weak eigenstate + + align:start position:0% +uh mass eigenstate to a weak eigenstate + + + align:start position:0% +uh mass eigenstate to a weak eigenstate +then + + align:start position:0% +then + + + align:start position:0% +then +on you know unitarily the the total + + align:start position:0% +on you know unitarily the the total + + + align:start position:0% +on you know unitarily the the total +number of + + align:start position:0% +number of + + + align:start position:0% +number of +particles in this discussion is + + align:start position:0% +particles in this discussion is + + + align:start position:0% +particles in this discussion is +conserved uh this will change if there + + align:start position:0% +conserved uh this will change if there + + + align:start position:0% +conserved uh this will change if there +would be for example a fourth generation + + align:start position:0% +would be for example a fourth generation + + + align:start position:0% +would be for example a fourth generation +particle + + align:start position:0% +particle + + + align:start position:0% +particle +so the study of weak charge interaction + + align:start position:0% +so the study of weak charge interaction + + + align:start position:0% +so the study of weak charge interaction +with quark helps us to understand + + align:start position:0% +with quark helps us to understand + + + align:start position:0% +with quark helps us to understand +whether or not there might be a fourth + + align:start position:0% +whether or not there might be a fourth + + + align:start position:0% +whether or not there might be a fourth +generation + + align:start position:0% +generation + + + align:start position:0% +generation +um we'll not go into too much detail + + align:start position:0% +um we'll not go into too much detail + + + align:start position:0% +um we'll not go into too much detail +here but it also the the + + align:start position:0% +here but it also the the + + + align:start position:0% +here but it also the the +complex space um explains part of + + align:start position:0% +complex space um explains part of + + + align:start position:0% +complex space um explains part of +uh our understanding of cp violation + + align:start position:0% +uh our understanding of cp violation + + + align:start position:0% +uh our understanding of cp violation +and we might discuss it in a little bit + + align:start position:0% +and we might discuss it in a little bit + + + align:start position:0% +and we might discuss it in a little bit +of a later of a later lecture + + align:start position:0% +of a later of a later lecture + + + align:start position:0% +of a later of a later lecture +but nevertheless so what we can actually + + align:start position:0% +but nevertheless so what we can actually + + + align:start position:0% +but nevertheless so what we can actually +form here is those unitarity constraints + + align:start position:0% + + + + align:start position:0% + +just simply summing over the matrix + + align:start position:0% +just simply summing over the matrix + + + align:start position:0% +just simply summing over the matrix +elements + + align:start position:0% +elements + + + align:start position:0% +elements +the scalar product of matrix elements + + align:start position:0% +the scalar product of matrix elements + + + align:start position:0% +the scalar product of matrix elements +and those where + + align:start position:0% +and those where + + + align:start position:0% +and those where +the contribution vanishes vanishes so + + align:start position:0% +the contribution vanishes vanishes so + + + align:start position:0% +the contribution vanishes vanishes so +those where + + align:start position:0% +those where + + + align:start position:0% +those where +j and k are not equal those um + + align:start position:0% +j and k are not equal those um + + + align:start position:0% +j and k are not equal those um +can be represented as a triangle that's + + align:start position:0% +can be represented as a triangle that's + + + align:start position:0% +can be represented as a triangle that's +quite interesting you can just rewrite + + align:start position:0% +quite interesting you can just rewrite + + + align:start position:0% +quite interesting you can just rewrite +this + + align:start position:0% +this + + + align:start position:0% +this +you just say for those three elements of + + align:start position:0% +you just say for those three elements of + + + align:start position:0% +you just say for those three elements of +the sum are equal to zero + + align:start position:0% +the sum are equal to zero + + + align:start position:0% +the sum are equal to zero +then you normalize by one element in + + align:start position:0% +then you normalize by one element in + + + align:start position:0% +then you normalize by one element in +this case here + + align:start position:0% +this case here + + + align:start position:0% +this case here +normalized by uh vcd + + align:start position:0% +normalized by uh vcd + + + align:start position:0% +normalized by uh vcd +vcb and so then this makes this point + + align:start position:0% +vcb and so then this makes this point + + + align:start position:0% +vcb and so then this makes this point +being zero + + align:start position:0% +being zero + + + align:start position:0% +being zero +and so we have this nice triangle here + + align:start position:0% +and so we have this nice triangle here + + + align:start position:0% +and so we have this nice triangle here +which has + + align:start position:0% +which has + + + align:start position:0% +which has +three angles alpha data and gamma + + align:start position:0% +three angles alpha data and gamma + + + align:start position:0% +three angles alpha data and gamma +and this point here rho and eta + + align:start position:0% +and this point here rho and eta + + + align:start position:0% +and this point here rho and eta +and so this is a nice way to illustrate + + align:start position:0% +and so this is a nice way to illustrate + + + align:start position:0% +and so this is a nice way to illustrate +actual measurements of the elements + + align:start position:0% +actual measurements of the elements + + + align:start position:0% +actual measurements of the elements +of this ckm metric of the ckm matrix + + align:start position:0% +of this ckm metric of the ckm matrix + + + align:start position:0% +of this ckm metric of the ckm matrix +element + + align:start position:0% +element + + + align:start position:0% +element +and without actually explaining how we + + align:start position:0% +and without actually explaining how we + + + align:start position:0% +and without actually explaining how we +do this experiment you can assume that + + align:start position:0% +do this experiment you can assume that + + + align:start position:0% +do this experiment you can assume that +you know all measurements have or you + + align:start position:0% +you know all measurements have or you + + + align:start position:0% +you know all measurements have or you +can understand that all measurements + + align:start position:0% +can understand that all measurements + + + align:start position:0% +can understand that all measurements +have + + align:start position:0% +have + + + align:start position:0% +have +to do with the weak interaction with + + align:start position:0% +to do with the weak interaction with + + + align:start position:0% +to do with the weak interaction with +kwarf that's how we have access + + align:start position:0% +kwarf that's how we have access + + + align:start position:0% +kwarf that's how we have access +to the um speaker and matrix elements + + align:start position:0% +to the um speaker and matrix elements + + + align:start position:0% +to the um speaker and matrix elements +uh sometimes this results in + + align:start position:0% +uh sometimes this results in + + + align:start position:0% +uh sometimes this results in +modification of + + align:start position:0% +modification of + + + align:start position:0% +modification of +masses or splitting of mass states and + + align:start position:0% +masses or splitting of mass states and + + + align:start position:0% +masses or splitting of mass states and +sometimes the direct measurement + + align:start position:0% +sometimes the direct measurement + + + align:start position:0% +sometimes the direct measurement +of the coupling + + align:start position:0% +of the coupling + + + align:start position:0% +of the coupling +when you put all of those measurements + + align:start position:0% +when you put all of those measurements + + + align:start position:0% +when you put all of those measurements +back together you can + + align:start position:0% +back together you can + + + align:start position:0% +back together you can +look at this so we see on our triangle + + align:start position:0% +look at this so we see on our triangle + + + align:start position:0% +look at this so we see on our triangle +here + + align:start position:0% +here + + + align:start position:0% +here +we see this this point um + + align:start position:0% +we see this this point um + + + align:start position:0% +we see this this point um +etc and row which is given here in this + + align:start position:0% +etc and row which is given here in this + + + align:start position:0% +etc and row which is given here in this +plane and you see various number of + + align:start position:0% +plane and you see various number of + + + align:start position:0% +plane and you see various number of +measurements + + align:start position:0% +measurements + + + align:start position:0% +measurements +um which cause branch to um + + align:start position:0% +um which cause branch to um + + + align:start position:0% +um which cause branch to um +which corresponds to you know elements + + align:start position:0% +which corresponds to you know elements + + + align:start position:0% +which corresponds to you know elements +of this + + align:start position:0% +of this + + + align:start position:0% +of this +of the cklm metrics \ No newline at end of file diff --git a/vIjmMUI2w4c.txt b/vIjmMUI2w4c.txt new file mode 100644 index 0000000000000000000000000000000000000000..2f0eeadf8a44b1e9f2fae6dc20c0113673a4d49b --- /dev/null +++ b/vIjmMUI2w4c.txt @@ -0,0 +1,12019 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +to view additional materials from + + align:start position:0% +to view additional materials from + + + align:start position:0% +to view additional materials from +hundreds of MIT courses visit MIT + + align:start position:0% +hundreds of MIT courses visit MIT + + + align:start position:0% +hundreds of MIT courses visit MIT +opencourseware at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu you know I didn't get to say + + align:start position:0% +ocw.mit.edu you know I didn't get to say + + + align:start position:0% +ocw.mit.edu you know I didn't get to say +in person to you how how fun this class + + align:start position:0% +in person to you how how fun this class + + + align:start position:0% +in person to you how how fun this class +is but this is the material itself is + + align:start position:0% +is but this is the material itself is + + + align:start position:0% +is but this is the material itself is +definitely the the uh + + align:start position:0% +definitely the the uh + + + align:start position:0% +definitely the the uh +the most exciting in all the tw3 + + align:start position:0% +the most exciting in all the tw3 + + + align:start position:0% +the most exciting in all the tw3 +curriculum um I want to take a minute + + align:start position:0% +curriculum um I want to take a minute + + + align:start position:0% +curriculum um I want to take a minute +and just kind of reintroduce myself my + + align:start position:0% +and just kind of reintroduce myself my + + + align:start position:0% +and just kind of reintroduce myself my +name is Sanjay Sarma please call me + + align:start position:0% +name is Sanjay Sarma please call me + + + align:start position:0% +name is Sanjay Sarma please call me +Sanjay right I'm very informal I demand + + align:start position:0% +Sanjay right I'm very informal I demand + + + align:start position:0% +Sanjay right I'm very informal I demand +informality I will be informal to you as + + align:start position:0% +informality I will be informal to you as + + + align:start position:0% +informality I will be informal to you as +well I will learn all your names trust + + align:start position:0% +well I will learn all your names trust + + + align:start position:0% +well I will learn all your names trust +me how many people do we have in + + align:start position:0% +me how many people do we have in + + + align:start position:0% +me how many people do we have in +class 130 okay I'll learn half your + + align:start position:0% +class 130 okay I'll learn half your + + + align:start position:0% +class 130 okay I'll learn half your +names okay but we're going to have a lot + + align:start position:0% +names okay but we're going to have a lot + + + align:start position:0% +names okay but we're going to have a lot +of fun we the some of the classes are + + align:start position:0% +of fun we the some of the classes are + + + align:start position:0% +of fun we the some of the classes are +going to be videotaped uh because as + + align:start position:0% +going to be videotaped uh because as + + + align:start position:0% +going to be videotaped uh because as +we're doing it slightly differently this + + align:start position:0% +we're doing it slightly differently this + + + align:start position:0% +we're doing it slightly differently this +class is going to be a little + + align:start position:0% +class is going to be a little + + + align:start position:0% +class is going to be a little +more MIT than Harvard in other words + + align:start position:0% +more MIT than Harvard in other words + + + align:start position:0% +more MIT than Harvard in other words +we're going to do stuff um a little in a + + align:start position:0% +we're going to do stuff um a little in a + + + align:start position:0% +we're going to do stuff um a little in a +little more formal fundamental way um + + align:start position:0% +little more formal fundamental way um + + + align:start position:0% +little more formal fundamental way um +and it'll help us address and understand + + align:start position:0% +and it'll help us address and understand + + + align:start position:0% +and it'll help us address and understand +some of the uh Concepts especially in + + align:start position:0% +some of the uh Concepts especially in + + + align:start position:0% +some of the uh Concepts especially in +kinematics more intensely than if uh you + + align:start position:0% +kinematics more intensely than if uh you + + + align:start position:0% +kinematics more intensely than if uh you +took it the way that it's s in other + + align:start position:0% +took it the way that it's s in other + + + align:start position:0% +took it the way that it's s in other +classes um as I said my style is going + + align:start position:0% +classes um as I said my style is going + + + align:start position:0% +classes um as I said my style is going +to be very informal we're going to take + + align:start position:0% +to be very informal we're going to take + + + align:start position:0% +to be very informal we're going to take +Pi we're going to see who speaks we want + + align:start position:0% +Pi we're going to see who speaks we want + + + align:start position:0% +Pi we're going to see who speaks we want +you to speak up I'll ask questions uh + + align:start position:0% +you to speak up I'll ask questions uh + + + align:start position:0% +you to speak up I'll ask questions uh +you will never + + align:start position:0% +you will never + + + align:start position:0% +you will never +ever be uh penalized for seeing anything + + align:start position:0% +ever be uh penalized for seeing anything + + + align:start position:0% +ever be uh penalized for seeing anything +class you'll only get credit for it okay + + align:start position:0% +class you'll only get credit for it okay + + + align:start position:0% +class you'll only get credit for it okay +even if it's + + align:start position:0% +even if it's + + + align:start position:0% +even if it's +funny okay so in the last class we set + + align:start position:0% +funny okay so in the last class we set + + + align:start position:0% +funny okay so in the last class we set +up what we're going to do um I we + + align:start position:0% +up what we're going to do um I we + + + align:start position:0% +up what we're going to do um I we +explained that in the field of Dynamics + + align:start position:0% +explained that in the field of Dynamics + + + align:start position:0% +explained that in the field of Dynamics +there are actually two pieces there's + + align:start position:0% +there are actually two pieces there's + + + align:start position:0% +there are actually two pieces there's +kinematics and there's kinetics right + + align:start position:0% +kinematics and there's kinetics right + + + align:start position:0% +kinematics and there's kinetics right +and we said we would do kinematics in + + align:start position:0% +and we said we would do kinematics in + + + align:start position:0% +and we said we would do kinematics in +this class and we're going to do K + + align:start position:0% +this class and we're going to do K + + + align:start position:0% +this class and we're going to do K +kinetics afterwards kinematics is all + + align:start position:0% +kinetics afterwards kinematics is all + + + align:start position:0% +kinetics afterwards kinematics is all +about motion and as I said it's the most + + align:start position:0% +about motion and as I said it's the most + + + align:start position:0% +about motion and as I said it's the most +fun part of Dynamics so let me just + + align:start position:0% +fun part of Dynamics so let me just + + + align:start position:0% +fun part of Dynamics so let me just +lower this + + align:start position:0% + + + + align:start position:0% + +uh sorry sorry + + align:start position:0% + + + + align:start position:0% + +so there's no better way to get get + + align:start position:0% +so there's no better way to get get + + + align:start position:0% +so there's no better way to get get +going than to Simply start by writing + + align:start position:0% +going than to Simply start by writing + + + align:start position:0% +going than to Simply start by writing +out a + + align:start position:0% +out a + + + align:start position:0% +out a +problem and trying to solve it in class + + align:start position:0% +problem and trying to solve it in class + + + align:start position:0% +problem and trying to solve it in class +and that's what we're going to do now + + align:start position:0% +and that's what we're going to do now + + + align:start position:0% +and that's what we're going to do now +get this all lined up focused + + align:start position:0% + + + + align:start position:0% + +okay so the problem that we're going to + + align:start position:0% +okay so the problem that we're going to + + + align:start position:0% +okay so the problem that we're going to +start with is imagine that I'm standing + + align:start position:0% +start with is imagine that I'm standing + + + align:start position:0% +start with is imagine that I'm standing +here in the corner of this room okay I + + align:start position:0% +here in the corner of this room okay I + + + align:start position:0% +here in the corner of this room okay I +have a + + align:start position:0% +have a + + + align:start position:0% +have a +Frisbee and I throw it across the room + + align:start position:0% +Frisbee and I throw it across the room + + + align:start position:0% +Frisbee and I throw it across the room +the Frisbee translates that as it moves + + align:start position:0% +the Frisbee translates that as it moves + + + align:start position:0% +the Frisbee translates that as it moves +it + + align:start position:0% +it + + + align:start position:0% +it +rotates and um let's make it more + + align:start position:0% +rotates and um let's make it more + + + align:start position:0% +rotates and um let's make it more +interesting there's an insect on the + + align:start position:0% +interesting there's an insect on the + + + align:start position:0% +interesting there's an insect on the +Frisbee okay and when the frisbee is + + align:start position:0% +Frisbee okay and when the frisbee is + + + align:start position:0% +Frisbee okay and when the frisbee is +moving across the room and rotating in + + align:start position:0% +moving across the room and rotating in + + + align:start position:0% +moving across the room and rotating in +insect starts + + align:start position:0% +insect starts + + + align:start position:0% +insect starts +running away from the + + align:start position:0% +running away from the + + + align:start position:0% +running away from the +center okay now this is a made of + + align:start position:0% +center okay now this is a made of + + + align:start position:0% +center okay now this is a made of +problem but this is the problem I'm + + align:start position:0% +problem but this is the problem I'm + + + align:start position:0% +problem but this is the problem I'm +going to solve today and what does + + align:start position:0% +going to solve today and what does + + + align:start position:0% +going to solve today and what does +solving a problem mean I'll solve a + + align:start position:0% +solving a problem mean I'll solve a + + + align:start position:0% +solving a problem mean I'll solve a +piece of it but let's let's examine what + + align:start position:0% +piece of it but let's let's examine what + + + align:start position:0% +piece of it but let's let's examine what +this could mean first of all this is + + align:start position:0% +this could mean first of all this is + + + align:start position:0% +this could mean first of all this is +obviously a silly you know exercise but + + align:start position:0% +obviously a silly you know exercise but + + + align:start position:0% +obviously a silly you know exercise but +um if you imagine an astronaut on the + + align:start position:0% +um if you imagine an astronaut on the + + + align:start position:0% +um if you imagine an astronaut on the +space shuttle hurtling through + + align:start position:0% +space shuttle hurtling through + + + align:start position:0% +space shuttle hurtling through +space um this is a similar problem and + + align:start position:0% +space um this is a similar problem and + + + align:start position:0% +space um this is a similar problem and +the question you might ask is the + + align:start position:0% +the question you might ask is the + + + align:start position:0% +the question you might ask is the +astronauts boots let's say the're + + align:start position:0% +astronauts boots let's say the're + + + align:start position:0% +astronauts boots let's say the're +magnetic exert a certain force on the + + align:start position:0% +magnetic exert a certain force on the + + + align:start position:0% +magnetic exert a certain force on the +space + + align:start position:0% +space + + + align:start position:0% +space +shuttle right now + + align:start position:0% +shuttle right now + + + align:start position:0% +shuttle right now +obviously uh there are certain + + align:start position:0% +obviously uh there are certain + + + align:start position:0% +obviously uh there are certain +conditions under which the astronaut + + align:start position:0% +conditions under which the astronaut + + + align:start position:0% +conditions under which the astronaut +would lose contact with the space + + align:start position:0% +would lose contact with the space + + + align:start position:0% +would lose contact with the space +shuttle assuming the surface actually + + align:start position:0% +shuttle assuming the surface actually + + + align:start position:0% +shuttle assuming the surface actually +the surface of the space shule isn't ion + + align:start position:0% +the surface of the space shule isn't ion + + + align:start position:0% +the surface of the space shule isn't ion +it's aluminum so my example doesn't + + align:start position:0% +it's aluminum so my example doesn't + + + align:start position:0% +it's aluminum so my example doesn't +really hold but that's okay okay so + + align:start position:0% +really hold but that's okay okay so + + + align:start position:0% +really hold but that's okay okay so +assuming it assume it's iron why isn't + + align:start position:0% +assuming it assume it's iron why isn't + + + align:start position:0% +assuming it assume it's iron why isn't +it Alum why isn't it iron because yeah + + align:start position:0% +it Alum why isn't it iron because yeah + + + align:start position:0% +it Alum why isn't it iron because yeah +it's heavy yeah we know all right but is + + align:start position:0% +it's heavy yeah we know all right but is + + + align:start position:0% +it's heavy yeah we know all right but is +assume it's iron right so let's assume + + align:start position:0% +assume it's iron right so let's assume + + + align:start position:0% +assume it's iron right so let's assume +that the astronaut's holding on to the + + align:start position:0% +that the astronaut's holding on to the + + + align:start position:0% +that the astronaut's holding on to the +space shut using a magnet using magnetic + + align:start position:0% +space shut using a magnet using magnetic + + + align:start position:0% +space shut using a magnet using magnetic +boots under what conditions would the + + align:start position:0% +boots under what conditions would the + + + align:start position:0% +boots under what conditions would the +astronaut stay in contact with the space + + align:start position:0% +astronaut stay in contact with the space + + + align:start position:0% +astronaut stay in contact with the space +shuttle + + align:start position:0% + + + + align:start position:0% + +anyone + + align:start position:0% +anyone + + + align:start position:0% +anyone +hi excuse + + align:start position:0% +hi excuse + + + align:start position:0% +hi excuse +me + + align:start position:0% +me + + + align:start position:0% +me +sorrys so under what conditions would + + align:start position:0% +sorrys so under what conditions would + + + align:start position:0% +sorrys so under what conditions would +the astronaut stay in contact with the + + align:start position:0% +the astronaut stay in contact with the + + + align:start position:0% +the astronaut stay in contact with the +space shuttle + + align:start position:0% +space shuttle + + + align:start position:0% +space shuttle +space shuttles swirling through space + + align:start position:0% +space shuttles swirling through space + + + align:start position:0% +space shuttles swirling through space +it's hot in here isn't it let's open the + + align:start position:0% +it's hot in here isn't it let's open the + + + align:start position:0% +it's hot in here isn't it let's open the +windows I don't know if there's a way to + + align:start position:0% +windows I don't know if there's a way to + + + align:start position:0% +windows I don't know if there's a way to +do + + align:start position:0% +do + + + align:start position:0% +do +this go ahead how do how does the + + align:start position:0% +this go ahead how do how does the + + + align:start position:0% +this go ahead how do how does the +astronaut stay in touch with the space + + align:start position:0% +astronaut stay in touch with the space + + + align:start position:0% +astronaut stay in touch with the space +shuttle okay we'll figure this out it's + + align:start position:0% +shuttle okay we'll figure this out it's + + + align:start position:0% +shuttle okay we'll figure this out it's +broken anyone raise your hands + + align:start position:0% + + + + align:start position:0% + +yes excellent magnetic force is strong + + align:start position:0% +yes excellent magnetic force is strong + + + align:start position:0% +yes excellent magnetic force is strong +enough to keep him or her in contact + + align:start position:0% +enough to keep him or her in contact + + + align:start position:0% +enough to keep him or her in contact +uh and able to overcome whatever force + + align:start position:0% +uh and able to overcome whatever force + + + align:start position:0% +uh and able to overcome whatever force +is pulling him or her away from the + + align:start position:0% +is pulling him or her away from the + + + align:start position:0% +is pulling him or her away from the +space shuttle what force is pulling him + + align:start position:0% +space shuttle what force is pulling him + + + align:start position:0% +space shuttle what force is pulling him +or her away from the space + + align:start position:0% + + + + align:start position:0% + +shuttle what + + align:start position:0% +shuttle what + + + align:start position:0% +shuttle what +else inertial Force what's that + + align:start position:0% + + + + align:start position:0% + +mean + + align:start position:0% + + + + align:start position:0% + +yeah yeah some + + align:start position:0% + + + + align:start position:0% + +that's right look it's very simple right + + align:start position:0% +that's right look it's very simple right + + + align:start position:0% +that's right look it's very simple right +think of this astronaut forget the + + align:start position:0% +think of this astronaut forget the + + + align:start position:0% +think of this astronaut forget the +spaceship imagine you know just imagine + + align:start position:0% +spaceship imagine you know just imagine + + + align:start position:0% +spaceship imagine you know just imagine +the spaceship isn't there right if you + + align:start position:0% +the spaceship isn't there right if you + + + align:start position:0% +the spaceship isn't there right if you +just think of the astronaut this guy + + align:start position:0% +just think of the astronaut this guy + + + align:start position:0% +just think of the astronaut this guy +this woman is hurling through space + + align:start position:0% +this woman is hurling through space + + + align:start position:0% +this woman is hurling through space +right and it's he or she's doing it + + align:start position:0% +right and it's he or she's doing it + + + align:start position:0% +right and it's he or she's doing it +under the influence of a certain + + align:start position:0% +under the influence of a certain + + + align:start position:0% +under the influence of a certain +force and that Force had better be equal + + align:start position:0% +force and that Force had better be equal + + + align:start position:0% +force and that Force had better be equal +to mass times the acceleration of that + + align:start position:0% +to mass times the acceleration of that + + + align:start position:0% +to mass times the acceleration of that +astronaut + + align:start position:0% +astronaut + + + align:start position:0% +astronaut +right if the magnetic force cannot equal + + align:start position:0% +right if the magnetic force cannot equal + + + align:start position:0% +right if the magnetic force cannot equal +or exceed n * whatever the a + + align:start position:0% +or exceed n * whatever the a + + + align:start position:0% +or exceed n * whatever the a +is by by astronaut + + align:start position:0% +is by by astronaut + + + align:start position:0% +is by by astronaut +right get it because the magnetic force + + align:start position:0% +right get it because the magnetic force + + + align:start position:0% +right get it because the magnetic force +cannot + + align:start position:0% +cannot + + + align:start position:0% +cannot +provide the uh change cannot affect the + + align:start position:0% +provide the uh change cannot affect the + + + align:start position:0% +provide the uh change cannot affect the +change in momentum rate of change in + + align:start position:0% +change in momentum rate of change in + + + align:start position:0% +change in momentum rate of change in +momentum required to keep the astronaut + + align:start position:0% +momentum required to keep the astronaut + + + align:start position:0% +momentum required to keep the astronaut +in position get it so the magnetic force + + align:start position:0% +in position get it so the magnetic force + + + align:start position:0% +in position get it so the magnetic force +is weak and the space shuttle is kind of + + align:start position:0% +is weak and the space shuttle is kind of + + + align:start position:0% +is weak and the space shuttle is kind of +spinning away right it + + align:start position:0% +spinning away right it + + + align:start position:0% +spinning away right it +the if the force isn't enough to keep + + align:start position:0% +the if the force isn't enough to keep + + + align:start position:0% +the if the force isn't enough to keep +the astronaut spinning accelerating with + + align:start position:0% +the astronaut spinning accelerating with + + + align:start position:0% +the astronaut spinning accelerating with +the space shuttle so they're going to + + align:start position:0% +the space shuttle so they're going to + + + align:start position:0% +the space shuttle so they're going to +separate right so this problem of you + + align:start position:0% +separate right so this problem of you + + + align:start position:0% +separate right so this problem of you +know me throwing a uh a a frisbee across + + align:start position:0% +know me throwing a uh a a frisbee across + + + align:start position:0% +know me throwing a uh a a frisbee across +the room an insect on the Frisbee + + align:start position:0% +the room an insect on the Frisbee + + + align:start position:0% +the room an insect on the Frisbee +running away from the center of the + + align:start position:0% +running away from the center of the + + + align:start position:0% +running away from the center of the +Frisbee the the the practical + + align:start position:0% +Frisbee the the the practical + + + align:start position:0% +Frisbee the the the practical +application of the problem could be hey + + align:start position:0% +application of the problem could be hey + + + align:start position:0% +application of the problem could be hey +what is the attractive Force for example + + align:start position:0% +what is the attractive Force for example + + + align:start position:0% +what is the attractive Force for example +the you know spiders have adhesive pads + + align:start position:0% +the you know spiders have adhesive pads + + + align:start position:0% +the you know spiders have adhesive pads +right + + align:start position:0% +right + + + align:start position:0% +right +so what is the kind of the adhesive + + align:start position:0% +so what is the kind of the adhesive + + + align:start position:0% +so what is the kind of the adhesive +force that the spider should be able to + + align:start position:0% +force that the spider should be able to + + + align:start position:0% +force that the spider should be able to +exert if it wants to stay on the Frisbee + + align:start position:0% +exert if it wants to stay on the Frisbee + + + align:start position:0% +exert if it wants to stay on the Frisbee +as I hle it across space and if it wants + + align:start position:0% +as I hle it across space and if it wants + + + align:start position:0% +as I hle it across space and if it wants +to kind of move on the Frisbee in some + + align:start position:0% +to kind of move on the Frisbee in some + + + align:start position:0% +to kind of move on the Frisbee in some +predetermined way get it now in order + + align:start position:0% +predetermined way get it now in order + + + align:start position:0% +predetermined way get it now in order +for me to answer this question what + + align:start position:0% +for me to answer this question what + + + align:start position:0% +for me to answer this question what +question do I need to answer + + align:start position:0% +question do I need to answer + + + align:start position:0% +question do I need to answer +first in order to answer the question + + align:start position:0% +first in order to answer the question + + + align:start position:0% +first in order to answer the question +what is the force required right let's + + align:start position:0% +what is the force required right let's + + + align:start position:0% +what is the force required right let's +say I know the mass of the the spider + + align:start position:0% +say I know the mass of the the spider + + + align:start position:0% +say I know the mass of the the spider +what is the one thing I need to figure + + align:start position:0% +what is the one thing I need to figure + + + align:start position:0% +what is the one thing I need to figure +out yep coordinate system you need yes + + align:start position:0% +out yep coordinate system you need yes + + + align:start position:0% +out yep coordinate system you need yes +that's how I start and then what do I + + align:start position:0% +that's how I start and then what do I + + + align:start position:0% +that's how I start and then what do I +need to + + align:start position:0% +need to + + + align:start position:0% +need to +do that's right all you need to do is + + align:start position:0% +do that's right all you need to do is + + + align:start position:0% +do that's right all you need to do is +find the + + align:start position:0% +find the + + + align:start position:0% +find the +acceleration of this dud the + + align:start position:0% +acceleration of this dud the + + + align:start position:0% +acceleration of this dud the +spider as it stays on the Frisbee and + + align:start position:0% +spider as it stays on the Frisbee and + + + align:start position:0% +spider as it stays on the Frisbee and +tries to move as it's hurling through + + align:start position:0% +tries to move as it's hurling through + + + align:start position:0% +tries to move as it's hurling through +space right that's all we need to do and + + align:start position:0% +space right that's all we need to do and + + + align:start position:0% +space right that's all we need to do and +answering that question is the subject + + align:start position:0% +answering that question is the subject + + + align:start position:0% +answering that question is the subject +of a topic which begins with k which is + + align:start position:0% +of a topic which begins with k which is + + + align:start position:0% +of a topic which begins with k which is +kinematics right okay all right so how + + align:start position:0% +kinematics right okay all right so how + + + align:start position:0% +kinematics right okay all right so how +do you do it + + align:start position:0% + + + + align:start position:0% + +how would you do + + align:start position:0% + + + + align:start position:0% + +it where do you + + align:start position:0% + + + + align:start position:0% + +start say it + + align:start position:0% + + + + align:start position:0% + +again okay and then what do you + + align:start position:0% + + + + align:start position:0% + +do very good right look if I'm sitting + + align:start position:0% +do very good right look if I'm sitting + + + align:start position:0% +do very good right look if I'm sitting +on the Frisby let's say I'm sitting on + + align:start position:0% +on the Frisby let's say I'm sitting on + + + align:start position:0% +on the Frisby let's say I'm sitting on +frisbee I'm the pilot of the Frisbee + + align:start position:0% +frisbee I'm the pilot of the Frisbee + + + align:start position:0% +frisbee I'm the pilot of the Frisbee +right and I see my buddy the astronaut + + align:start position:0% +right and I see my buddy the astronaut + + + align:start position:0% +right and I see my buddy the astronaut +trying to I move on the space shuttle + + align:start position:0% +trying to I move on the space shuttle + + + align:start position:0% +trying to I move on the space shuttle +right I'm or similarly I'm sitting on + + align:start position:0% +right I'm or similarly I'm sitting on + + + align:start position:0% +right I'm or similarly I'm sitting on +the Frisbee and I see this insect the + + align:start position:0% +the Frisbee and I see this insect the + + + align:start position:0% +the Frisbee and I see this insect the +spider running away from the center of + + align:start position:0% +spider running away from the center of + + + align:start position:0% +spider running away from the center of +the + + align:start position:0% +the + + + align:start position:0% +the +Frisbee with respect to myself what's a + + align:start position:0% +Frisbee with respect to myself what's a + + + align:start position:0% +Frisbee with respect to myself what's a +spider trying to + + align:start position:0% +spider trying to + + + align:start position:0% +spider trying to +do in a what what sort of path straight + + align:start position:0% +do in a what what sort of path straight + + + align:start position:0% +do in a what what sort of path straight +line right as far as I'm concerned just + + align:start position:0% +line right as far as I'm concerned just + + + align:start position:0% +line right as far as I'm concerned just +moving away in a straight line + + align:start position:0% +moving away in a straight line + + + align:start position:0% +moving away in a straight line +right what about with respect to the + + align:start position:0% +right what about with respect to the + + + align:start position:0% +right what about with respect to the +ground Observer of the Space Shuttle or + + align:start position:0% +ground Observer of the Space Shuttle or + + + align:start position:0% +ground Observer of the Space Shuttle or +with with respect to me what's the uh + + align:start position:0% +with with respect to me what's the uh + + + align:start position:0% +with with respect to me what's the uh +what's the uh Spider + + align:start position:0% +what's the uh Spider + + + align:start position:0% +what's the uh Spider +doing yeah it's kind of going like this + + align:start position:0% +doing yeah it's kind of going like this + + + align:start position:0% +doing yeah it's kind of going like this +right it's kind of bigger and bigger + + align:start position:0% +right it's kind of bigger and bigger + + + align:start position:0% +right it's kind of bigger and bigger +spiral kind of thing right so is the + + align:start position:0% +spiral kind of thing right so is the + + + align:start position:0% +spiral kind of thing right so is the +acceleration different depending on + + align:start position:0% +acceleration different depending on + + + align:start position:0% +acceleration different depending on +where I'm looking + + align:start position:0% +where I'm looking + + + align:start position:0% +where I'm looking +from yes okay which frame should I + + align:start position:0% + + + + align:start position:0% + +pick where should I look at it from + + align:start position:0% +pick where should I look at it from + + + align:start position:0% +pick where should I look at it from +let's say I'm on Earth where do I look + + align:start position:0% +let's say I'm on Earth where do I look + + + align:start position:0% +let's say I'm on Earth where do I look +at it from should I should I pick the + + align:start position:0% +at it from should I should I pick the + + + align:start position:0% +at it from should I should I pick the +frame on Earth should I pick the frame + + align:start position:0% +frame on Earth should I pick the frame + + + align:start position:0% +frame on Earth should I pick the frame +attached to the spider I mean to the to + + align:start position:0% +attached to the spider I mean to the to + + + align:start position:0% +attached to the spider I mean to the to +the spider should I pick a frame + + align:start position:0% +the spider should I pick a frame + + + align:start position:0% +the spider should I pick a frame +attached to the Frisbee which one should + + align:start position:0% +attached to the Frisbee which one should + + + align:start position:0% +attached to the Frisbee which one should +I pick where should I be looking at it + + align:start position:0% +I pick where should I be looking at it + + + align:start position:0% +I pick where should I be looking at it +to do this F is equal to + + align:start position:0% + + + + align:start position:0% + +ma because obviously the accelerations + + align:start position:0% +ma because obviously the accelerations + + + align:start position:0% +ma because obviously the accelerations +are different right a frame attached to + + align:start position:0% +are different right a frame attached to + + + align:start position:0% +are different right a frame attached to +the spider sees no acceleration + + align:start position:0% +the spider sees no acceleration + + + align:start position:0% +the spider sees no acceleration +whatsoever + + align:start position:0% +whatsoever + + + align:start position:0% +whatsoever +right okay this is + + align:start position:0% +right okay this is + + + align:start position:0% +right okay this is +irritating so which frame should I + + align:start position:0% +irritating so which frame should I + + + align:start position:0% +irritating so which frame should I +pick come on let's warm up we have + + align:start position:0% +pick come on let's warm up we have + + + align:start position:0% +pick come on let's warm up we have +another 15 weeks to go we going to be + + align:start position:0% +another 15 weeks to go we going to be + + + align:start position:0% +another 15 weeks to go we going to be +doing a lot + + align:start position:0% + + + + align:start position:0% + +talking that's excellent Insight so you + + align:start position:0% +talking that's excellent Insight so you + + + align:start position:0% +talking that's excellent Insight so you +got to pick some frame because if you + + align:start position:0% +got to pick some frame because if you + + + align:start position:0% +got to pick some frame because if you +pick the Frisbee then you're ignoring + + align:start position:0% +pick the Frisbee then you're ignoring + + + align:start position:0% +pick the Frisbee then you're ignoring +some things right so which frame should + + align:start position:0% +some things right so which frame should + + + align:start position:0% +some things right so which frame should +we pick that's exactly right but which + + align:start position:0% +we pick that's exactly right but which + + + align:start position:0% +we pick that's exactly right but which +one would you pick where you wouldn't + + align:start position:0% +one would you pick where you wouldn't + + + align:start position:0% +one would you pick where you wouldn't +have to add + + align:start position:0% +have to add + + + align:start position:0% +have to add +anything + + align:start position:0% +anything + + + align:start position:0% +anything +H which one the + + align:start position:0% +H which one the + + + align:start position:0% +H which one the +Earth what do you think the Earth but + + align:start position:0% +Earth what do you think the Earth but + + + align:start position:0% +Earth what do you think the Earth but +isn't the Earth moving + + align:start position:0% + + + + align:start position:0% + +what but that's true of any + + align:start position:0% +what but that's true of any + + + align:start position:0% +what but that's true of any +frame but you're actually on the right + + align:start position:0% +frame but you're actually on the right + + + align:start position:0% +frame but you're actually on the right +track should I tell you the answer the + + align:start position:0% +track should I tell you the answer the + + + align:start position:0% +track should I tell you the answer the +answer is actually you pick an inertial + + align:start position:0% +answer is actually you pick an inertial + + + align:start position:0% +answer is actually you pick an inertial +frame remember that word but there is no + + align:start position:0% +frame remember that word but there is no + + + align:start position:0% +frame remember that word but there is no +such thing as an inertial frame really + + align:start position:0% +such thing as an inertial frame really + + + align:start position:0% +such thing as an inertial frame really +okay what it means is it's a frame that + + align:start position:0% +okay what it means is it's a frame that + + + align:start position:0% +okay what it means is it's a frame that +is Motionless in space and the Earth + + align:start position:0% +is Motionless in space and the Earth + + + align:start position:0% +is Motionless in space and the Earth +moves with respect to that frame and the + + align:start position:0% +moves with respect to that frame and the + + + align:start position:0% +moves with respect to that frame and the +Frisbee or the space shuttle moves with + + align:start position:0% +Frisbee or the space shuttle moves with + + + align:start position:0% +Frisbee or the space shuttle moves with +respect to that frame and you need to + + align:start position:0% +respect to that frame and you need to + + + align:start position:0% +respect to that frame and you need to +calculate the acceleration with respect + + align:start position:0% +calculate the acceleration with respect + + + align:start position:0% +calculate the acceleration with respect +to that frame but it turns out that the + + align:start position:0% +to that frame but it turns out that the + + + align:start position:0% +to that frame but it turns out that the +relative velocity relative motion of the + + align:start position:0% +relative velocity relative motion of the + + + align:start position:0% +relative velocity relative motion of the +Earth with respect to inertial frame is + + align:start position:0% +Earth with respect to inertial frame is + + + align:start position:0% +Earth with respect to inertial frame is +much lower compared to the relative + + align:start position:0% +much lower compared to the relative + + + align:start position:0% +much lower compared to the relative +velocity of the Space Shuttle so we can + + align:start position:0% +velocity of the Space Shuttle so we can + + + align:start position:0% +velocity of the Space Shuttle so we can +just pick the Earth get it so it's + + align:start position:0% +just pick the Earth get it so it's + + + align:start position:0% +just pick the Earth get it so it's +actually an approximation so we're just + + align:start position:0% +actually an approximation so we're just + + + align:start position:0% +actually an approximation so we're just +going to pick the Earth right because + + align:start position:0% +going to pick the Earth right because + + + align:start position:0% +going to pick the Earth right because +space sh moves really fast on the earth + + align:start position:0% +space sh moves really fast on the earth + + + align:start position:0% +space sh moves really fast on the earth +so if you actually picked the inertial + + align:start position:0% +so if you actually picked the inertial + + + align:start position:0% +so if you actually picked the inertial +frame it would make such a big + + align:start position:0% +frame it would make such a big + + + align:start position:0% +frame it would make such a big +difference so from a Dynamics point of + + align:start position:0% +difference so from a Dynamics point of + + + align:start position:0% +difference so from a Dynamics point of +view we pick the Earth + + align:start position:0% +view we pick the Earth + + + align:start position:0% +view we pick the Earth +because it's an inertial frame or an + + align:start position:0% +because it's an inertial frame or an + + + align:start position:0% +because it's an inertial frame or an +approximation of inertial frame but from + + align:start position:0% +approximation of inertial frame but from + + + align:start position:0% +approximation of inertial frame but from +a kinematics point of view we don't care + + align:start position:0% +a kinematics point of view we don't care + + + align:start position:0% +a kinematics point of view we don't care +what an inertial frame is an inertial + + align:start position:0% +what an inertial frame is an inertial + + + align:start position:0% +what an inertial frame is an inertial +frame is simply the frame in which f is + + align:start position:0% +frame is simply the frame in which f is + + + align:start position:0% +frame is simply the frame in which f is +equal to ma right what we're going to + + align:start position:0% +equal to ma right what we're going to + + + align:start position:0% +equal to ma right what we're going to +concentrate on now is calculating the a + + align:start position:0% +concentrate on now is calculating the a + + + align:start position:0% +concentrate on now is calculating the a +in whichever frame you choose get it it + + align:start position:0% +in whichever frame you choose get it it + + + align:start position:0% +in whichever frame you choose get it it +just so happens then we start writing + + align:start position:0% +just so happens then we start writing + + + align:start position:0% +just so happens then we start writing +Dynamic equations by the way the word is + + align:start position:0% +Dynamic equations by the way the word is + + + align:start position:0% +Dynamic equations by the way the word is +the objective is dynamic or dynamical + + align:start position:0% +the objective is dynamic or dynamical + + + align:start position:0% +the objective is dynamic or dynamical +they're both correct okay it took me 20 + + align:start position:0% +they're both correct okay it took me 20 + + + align:start position:0% +they're both correct okay it took me 20 +years to figure this out + + align:start position:0% +years to figure this out + + + align:start position:0% +years to figure this out +but anyway um if you from a kinematics + + align:start position:0% +but anyway um if you from a kinematics + + + align:start position:0% +but anyway um if you from a kinematics +point of view we should be able to + + align:start position:0% +point of view we should be able to + + + align:start position:0% +point of view we should be able to +figure out the velocity of anything with + + align:start position:0% +figure out the velocity of anything with + + + align:start position:0% +figure out the velocity of anything with +respect to any frame right and then when + + align:start position:0% +respect to any frame right and then when + + + align:start position:0% +respect to any frame right and then when +we come to Dynamics we'll make sure we + + align:start position:0% +we come to Dynamics we'll make sure we + + + align:start position:0% +we come to Dynamics we'll make sure we +do the Spectrum inertial frame and write + + align:start position:0% +do the Spectrum inertial frame and write + + + align:start position:0% +do the Spectrum inertial frame and write +f is equal to ma but right now our focus + + align:start position:0% +f is equal to ma but right now our focus + + + align:start position:0% +f is equal to ma but right now our focus +is on the a all right so let's figure + + align:start position:0% +is on the a all right so let's figure + + + align:start position:0% +is on the a all right so let's figure +out how to + + align:start position:0% +out how to + + + align:start position:0% +out how to +calculate um the velocity of and the + + align:start position:0% +calculate um the velocity of and the + + + align:start position:0% +calculate um the velocity of and the +acceleration of the spider with respect + + align:start position:0% +acceleration of the spider with respect + + + align:start position:0% +acceleration of the spider with respect +to different frames and We Know by the + + align:start position:0% +to different frames and We Know by the + + + align:start position:0% +to different frames and We Know by the +way that the Earth is the frame we + + align:start position:0% +way that the Earth is the frame we + + + align:start position:0% +way that the Earth is the frame we +really care about but we don't care in + + align:start position:0% +really care about but we don't care in + + + align:start position:0% +really care about but we don't care in +kinematics right because kinematics is + + align:start position:0% +kinematics right because kinematics is + + + align:start position:0% +kinematics right because kinematics is +all motion we don't care about okay so + + align:start position:0% +all motion we don't care about okay so + + + align:start position:0% +all motion we don't care about okay so +what's a frame let me start by asking + + align:start position:0% +what's a frame let me start by asking + + + align:start position:0% +what's a frame let me start by asking +you to guess and then I'll tell you what + + align:start position:0% +you to guess and then I'll tell you what + + + align:start position:0% +you to guess and then I'll tell you what +it is what's a + + align:start position:0% + + + + align:start position:0% + +frame + + align:start position:0% +frame + + + align:start position:0% +frame +perspective yeah it's a + + align:start position:0% +perspective yeah it's a + + + align:start position:0% +perspective yeah it's a +perspective any other words for it + + align:start position:0% + + + + align:start position:0% + +I'm actually holding a frame here's what + + align:start position:0% +I'm actually holding a frame here's what + + + align:start position:0% +I'm actually holding a frame here's what +a frame is when in doubt imagine a frame + + align:start position:0% +a frame is when in doubt imagine a frame + + + align:start position:0% +a frame is when in doubt imagine a frame +to be some sort of three-dimensional + + align:start position:0% +to be some sort of three-dimensional + + + align:start position:0% +to be some sort of three-dimensional +transparency okay now let's limit + + align:start position:0% +transparency okay now let's limit + + + align:start position:0% +transparency okay now let's limit +ourselves to two- dimensional space a + + align:start position:0% +ourselves to two- dimensional space a + + + align:start position:0% +ourselves to two- dimensional space a +frame is a + + align:start position:0% +frame is a + + + align:start position:0% +frame is a +transparency that's all it is it is this + + align:start position:0% +transparency that's all it is it is this + + + align:start position:0% +transparency that's all it is it is this +imaginary set of points that are kind of + + align:start position:0% +imaginary set of points that are kind of + + + align:start position:0% +imaginary set of points that are kind of +rigid with respect to each other get it + + align:start position:0% +rigid with respect to each other get it + + + align:start position:0% +rigid with respect to each other get it +so here's a frame let us say that I say + + align:start position:0% +so here's a frame let us say that I say + + + align:start position:0% +so here's a frame let us say that I say +that draw it here + + align:start position:0% +that draw it here + + + align:start position:0% +that draw it here +this is the corner of the + + align:start position:0% + + + + align:start position:0% + +room + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and this is the + + align:start position:0% +and this is the + + + align:start position:0% +and this is the +Frisbee now I can pick attach a frame to + + align:start position:0% +Frisbee now I can pick attach a frame to + + + align:start position:0% +Frisbee now I can pick attach a frame to +the Frisbee as + + align:start position:0% + + + + align:start position:0% + +well okay now I'll call let me remove + + align:start position:0% +well okay now I'll call let me remove + + + align:start position:0% +well okay now I'll call let me remove +this I'm going to call this guy from + + align:start position:0% +this I'm going to call this guy from + + + align:start position:0% +this I'm going to call this guy from +name f for Frisbee for the time + + align:start position:0% +name f for Frisbee for the time + + + align:start position:0% +name f for Frisbee for the time +being and every point of the + + align:start position:0% +being and every point of the + + + align:start position:0% +being and every point of the +transparency moves kind of rigidly and + + align:start position:0% +transparency moves kind of rigidly and + + + align:start position:0% +transparency moves kind of rigidly and +that's that frame that's frame F get it + + align:start position:0% +that's that frame that's frame F get it + + + align:start position:0% +that's that frame that's frame F get it +I used a capital letter F I put a circle + + align:start position:0% +I used a capital letter F I put a circle + + + align:start position:0% +I used a capital letter F I put a circle +around it I put a squiggly line right + + align:start position:0% +around it I put a squiggly line right + + + align:start position:0% +around it I put a squiggly line right +and I called it a frame so this is the + + align:start position:0% +and I called it a frame so this is the + + + align:start position:0% +and I called it a frame so this is the +frame right and this is let's call it + + align:start position:0% +frame right and this is let's call it + + + align:start position:0% +frame right and this is let's call it +Earth e right so let's call this planet + + align:start position:0% + + + + align:start position:0% + +Earth where most of us live + + align:start position:0% +Earth where most of us live + + + align:start position:0% +Earth where most of us live +and + + align:start position:0% +and + + + align:start position:0% +and +uh so this is the frame attached to this + + align:start position:0% +uh so this is the frame attached to this + + + align:start position:0% +uh so this is the frame attached to this +frisbee right it can turn it can move + + align:start position:0% +frisbee right it can turn it can move + + + align:start position:0% +frisbee right it can turn it can move +whatever right this is the frame + + align:start position:0% +whatever right this is the frame + + + align:start position:0% +whatever right this is the frame +attached to the Earth right now + + align:start position:0% +attached to the Earth right now + + + align:start position:0% +attached to the Earth right now +stationary and this guy's moving spect + + align:start position:0% +stationary and this guy's moving spect + + + align:start position:0% +stationary and this guy's moving spect +to this got + + align:start position:0% +to this got + + + align:start position:0% +to this got +it + + align:start position:0% +it + + + align:start position:0% +it +so with respect to the Frisbee oh oh by + + align:start position:0% +so with respect to the Frisbee oh oh by + + + align:start position:0% +so with respect to the Frisbee oh oh by +the way now we have an insect here the + + align:start position:0% +the way now we have an insect here the + + + align:start position:0% +the way now we have an insect here the +spider let's call it + + align:start position:0% +spider let's call it + + + align:start position:0% +spider let's call it +s and it's kind of heading out in some + + align:start position:0% +s and it's kind of heading out in some + + + align:start position:0% +s and it's kind of heading out in some +Direction like this right so with + + align:start position:0% +Direction like this right so with + + + align:start position:0% +Direction like this right so with +respect to the frisbee + + align:start position:0% +respect to the frisbee + + + align:start position:0% +respect to the frisbee +if you're sitting on the Frisbee f is + + align:start position:0% +if you're sitting on the Frisbee f is + + + align:start position:0% +if you're sitting on the Frisbee f is +frozen + + align:start position:0% +frozen + + + align:start position:0% +frozen +right so all you see is the spider kind + + align:start position:0% +right so all you see is the spider kind + + + align:start position:0% +right so all you see is the spider kind +of walking away but respect to the + + align:start position:0% +of walking away but respect to the + + + align:start position:0% +of walking away but respect to the +ground or the Earth e right S is doing + + align:start position:0% +ground or the Earth e right S is doing + + + align:start position:0% +ground or the Earth e right S is doing +all sorts of funny things + + align:start position:0% +all sorts of funny things + + + align:start position:0% +all sorts of funny things +right so that's what a frame is so now + + align:start position:0% +right so that's what a frame is so now + + + align:start position:0% +right so that's what a frame is so now +with that let's jump in and get a little + + align:start position:0% +with that let's jump in and get a little + + + align:start position:0% +with that let's jump in and get a little +more detail I'll use transparencies once + + align:start position:0% +more detail I'll use transparencies once + + + align:start position:0% +more detail I'll use transparencies once +in a while but I really be doing chalk + + align:start position:0% +in a while but I really be doing chalk + + + align:start position:0% +in a while but I really be doing chalk +and talk right so you need to stop me + + align:start position:0% +and talk right so you need to stop me + + + align:start position:0% +and talk right so you need to stop me +I'll have my back turned towards you you + + align:start position:0% +I'll have my back turned towards you you + + + align:start position:0% +I'll have my back turned towards you you +need to stop me if you have any + + align:start position:0% +need to stop me if you have any + + + align:start position:0% +need to stop me if you have any +questions I'll put this away um in + + align:start position:0% +questions I'll put this away um in + + + align:start position:0% +questions I'll put this away um in +future by the way um if you don't mind + + align:start position:0% +future by the way um if you don't mind + + + align:start position:0% +future by the way um if you don't mind +what's your name I'm + + align:start position:0% +what's your name I'm + + + align:start position:0% +what's your name I'm +sorry kie if you don't mind you know + + align:start position:0% +sorry kie if you don't mind you know + + + align:start position:0% +sorry kie if you don't mind you know +this thing being right next to you it's + + align:start position:0% +this thing being right next to you it's + + + align:start position:0% +this thing being right next to you it's +hot um it's okay but if you do you know + + align:start position:0% +hot um it's okay but if you do you know + + + align:start position:0% +hot um it's okay but if you do you know +leave that chair unoccupied all right + + align:start position:0% +leave that chair unoccupied all right + + + align:start position:0% +leave that chair unoccupied all right +I've learned one name cly getting there + + align:start position:0% +I've learned one name cly getting there + + + align:start position:0% +I've learned one name cly getting there +another 129 to + + align:start position:0% +another 129 to + + + align:start position:0% +another 129 to +go okay so let's start the actual uh the + + align:start position:0% +go okay so let's start the actual uh the + + + align:start position:0% +go okay so let's start the actual uh the +serious portion of the class + + align:start position:0% + + + + align:start position:0% + +so I said a frame was basically a + + align:start position:0% +so I said a frame was basically a + + + align:start position:0% +so I said a frame was basically a +transparency okay and that's the best + + align:start position:0% +transparency okay and that's the best + + + align:start position:0% +transparency okay and that's the best +way to think about it um and a frame is + + align:start position:0% +way to think about it um and a frame is + + + align:start position:0% +way to think about it um and a frame is +essentially a in two dimensions a rigid + + align:start position:0% +essentially a in two dimensions a rigid + + + align:start position:0% +essentially a in two dimensions a rigid +imaginary set of points that are rigidly + + align:start position:0% +imaginary set of points that are rigidly + + + align:start position:0% +imaginary set of points that are rigidly +connected to each other okay like the + + align:start position:0% +connected to each other okay like the + + + align:start position:0% +connected to each other okay like the +transparency it doesn't mean there's any + + align:start position:0% +transparency it doesn't mean there's any + + + align:start position:0% +transparency it doesn't mean there's any +stuff there is an actual rigid body of + + align:start position:0% +stuff there is an actual rigid body of + + + align:start position:0% +stuff there is an actual rigid body of +frame + + align:start position:0% + + + + align:start position:0% + +anybody Yes No Maybe + + align:start position:0% +anybody Yes No Maybe + + + align:start position:0% +anybody Yes No Maybe +sometimes yes or no yes yes it is it + + align:start position:0% +sometimes yes or no yes yes it is it + + + align:start position:0% +sometimes yes or no yes yes it is it +just happens to be a a set of points + + align:start position:0% +just happens to be a a set of points + + + align:start position:0% +just happens to be a a set of points +where there's Mass on a frame get it + + align:start position:0% +where there's Mass on a frame get it + + + align:start position:0% +where there's Mass on a frame get it +that's all there is to it a rigid body + + align:start position:0% +that's all there is to it a rigid body + + + align:start position:0% +that's all there is to it a rigid body +is a set of points where there's Mass so + + align:start position:0% +is a set of points where there's Mass so + + + align:start position:0% +is a set of points where there's Mass so +a rigid body can also have a frame + + align:start position:0% +a rigid body can also have a frame + + + align:start position:0% +a rigid body can also have a frame +embedded in it and in fact it is kind of + + align:start position:0% +embedded in it and in fact it is kind of + + + align:start position:0% +embedded in it and in fact it is kind of +a frame it just has a mass right okay so + + align:start position:0% +a frame it just has a mass right okay so + + + align:start position:0% +a frame it just has a mass right okay so +let's start + + align:start position:0% + + + + align:start position:0% + +a + + align:start position:0% + + + + align:start position:0% + +frame is a + + align:start position:0% + + + + align:start position:0% + +rigidly + + align:start position:0% + + + + align:start position:0% + +connected continuum + + align:start position:0% + + + + align:start position:0% + +of + + align:start position:0% + + + + align:start position:0% + +imaginary + + align:start position:0% + + + + align:start position:0% + +points right now one of the things I did + + align:start position:0% +points right now one of the things I did + + + align:start position:0% +points right now one of the things I did +was in that frame I put I picked a point + + align:start position:0% +was in that frame I put I picked a point + + + align:start position:0% +was in that frame I put I picked a point +I pied two little + + align:start position:0% +I pied two little + + + align:start position:0% +I pied two little +vectors right two vectors you know what + + align:start position:0% +vectors right two vectors you know what + + + align:start position:0% +vectors right two vectors you know what +those vectors are called + + align:start position:0% + + + + align:start position:0% + +those little two vectors I put + + align:start position:0% +those little two vectors I put + + + align:start position:0% +those little two vectors I put +yeah yeah you could say axis you could + + align:start position:0% +yeah yeah you could say axis you could + + + align:start position:0% +yeah yeah you could say axis you could +even call them unit vectors right but + + align:start position:0% +even call them unit vectors right but + + + align:start position:0% +even call them unit vectors right but +the technical term is the're Basis + + align:start position:0% +the technical term is the're Basis + + + align:start position:0% +the technical term is the're Basis +vectors okay so I can identify a frame + + align:start position:0% +vectors okay so I can identify a frame + + + align:start position:0% +vectors okay so I can identify a frame +you know that transparency I could take + + align:start position:0% +you know that transparency I could take + + + align:start position:0% +you know that transparency I could take +the bottom left corner and take put two + + align:start position:0% +the bottom left corner and take put two + + + align:start position:0% +the bottom left corner and take put two +little unit length vectors at the bottom + + align:start position:0% +little unit length vectors at the bottom + + + align:start position:0% +little unit length vectors at the bottom +left corner right and that becomes the + + align:start position:0% +left corner right and that becomes the + + + align:start position:0% +left corner right and that becomes the +basis vectors of the frame + + align:start position:0% + + + + align:start position:0% + +I pick them once I can pick any two + + align:start position:0% +I pick them once I can pick any two + + + align:start position:0% +I pick them once I can pick any two +mutually perpendicular vectors I don't + + align:start position:0% +mutually perpendicular vectors I don't + + + align:start position:0% +mutually perpendicular vectors I don't +need them to be mutually perpendicular + + align:start position:0% +need them to be mutually perpendicular + + + align:start position:0% +need them to be mutually perpendicular +they just shouldn't be parallel right + + align:start position:0% +they just shouldn't be parallel right + + + align:start position:0% +they just shouldn't be parallel right +but for convenience we pick two mutually + + align:start position:0% +but for convenience we pick two mutually + + + align:start position:0% +but for convenience we pick two mutually +perpendicular little vectors unit length + + align:start position:0% +perpendicular little vectors unit length + + + align:start position:0% +perpendicular little vectors unit length +and we call them basis vectors right + + align:start position:0% +and we call them basis vectors right + + + align:start position:0% +and we call them basis vectors right +so we + + align:start position:0% +so we + + + align:start position:0% +so we +can + + align:start position:0% +can + + + align:start position:0% +can +embed + + align:start position:0% + + + + align:start position:0% + +two mutually + + align:start position:0% + + + + align:start position:0% + +perpendicular unit + + align:start position:0% + + + + align:start position:0% + +vectors um which are frozen for that + + align:start position:0% +vectors um which are frozen for that + + + align:start position:0% +vectors um which are frozen for that +frame right + + align:start position:0% +frame right + + + align:start position:0% +frame right +once and for + + align:start position:0% +once and for + + + align:start position:0% +once and for +all + + align:start position:0% +all + + + align:start position:0% +all +and called them + + align:start position:0% + + + + align:start position:0% + +the basis + + align:start position:0% + + + + align:start position:0% + +vectors okay so what that means is that + + align:start position:0% +vectors okay so what that means is that + + + align:start position:0% +vectors okay so what that means is that +I could + + align:start position:0% +I could + + + align:start position:0% +I could +take uh I raised it you know what let me + + align:start position:0% +take uh I raised it you know what let me + + + align:start position:0% +take uh I raised it you know what let me +keep that down until I finish + + align:start position:0% +keep that down until I finish + + + align:start position:0% +keep that down until I finish +my + + align:start position:0% + + + + align:start position:0% + +demonstrations I could just + + align:start position:0% + + + + align:start position:0% + +take in this case + + align:start position:0% +take in this case + + + align:start position:0% +take in this case +for this Frame right for this Frame the + + align:start position:0% +for this Frame right for this Frame the + + + align:start position:0% +for this Frame right for this Frame the +edge of the transparency is here can you + + align:start position:0% +edge of the transparency is here can you + + + align:start position:0% +edge of the transparency is here can you +see it let me see can you see that's the + + align:start position:0% +see it let me see can you see that's the + + + align:start position:0% +see it let me see can you see that's the +edge of the transparency I could have + + align:start position:0% +edge of the transparency I could have + + + align:start position:0% +edge of the transparency I could have +picked a little unit Vector along you + + align:start position:0% +picked a little unit Vector along you + + + align:start position:0% +picked a little unit Vector along you +know the horizontal a little one along + + align:start position:0% +know the horizontal a little one along + + + align:start position:0% +know the horizontal a little one along +the vertical and call them the two basis + + align:start position:0% +the vertical and call them the two basis + + + align:start position:0% +the vertical and call them the two basis +vectors of that frame does it matter + + align:start position:0% +vectors of that frame does it matter + + + align:start position:0% +vectors of that frame does it matter +where I pick + + align:start position:0% +where I pick + + + align:start position:0% +where I pick +them no I can pick any basis Vector + + align:start position:0% +them no I can pick any basis Vector + + + align:start position:0% +them no I can pick any basis Vector +right so I'm going to pick them here and + + align:start position:0% +right so I'm going to pick them here and + + + align:start position:0% +right so I'm going to pick them here and +I want to give you a little convention + + align:start position:0% +I want to give you a little convention + + + align:start position:0% +I want to give you a little convention +I'm going to refer to them as little + + align:start position:0% +I'm going to refer to them as little + + + align:start position:0% +I'm going to refer to them as little +F1 and little F2 the underscore + + align:start position:0% +F1 and little F2 the underscore + + + align:start position:0% +F1 and little F2 the underscore +indicates that it's a little + + align:start position:0% + + + + align:start position:0% + +Vector okay now I can + + align:start position:0% +Vector okay now I can + + + align:start position:0% +Vector okay now I can +similarly + + align:start position:0% +similarly + + + align:start position:0% +similarly +take Earth planet + + align:start position:0% +take Earth planet + + + align:start position:0% +take Earth planet +Earth where most of us + + align:start position:0% +Earth where most of us + + + align:start position:0% +Earth where most of us +live and call this + + align:start position:0% +live and call this + + + align:start position:0% +live and call this +E1 and E2 and this is my little + + align:start position:0% +E1 and E2 and this is my little + + + align:start position:0% +E1 and E2 and this is my little +convention right I'm going to limit my + + align:start position:0% +convention right I'm going to limit my + + + align:start position:0% +convention right I'm going to limit my +descriptions to two Dimensions but + + align:start position:0% +descriptions to two Dimensions but + + + align:start position:0% +descriptions to two Dimensions but +everything I tell you about in + + align:start position:0% +everything I tell you about in + + + align:start position:0% +everything I tell you about in +kinematics easily and seamlessly + + align:start position:0% +kinematics easily and seamlessly + + + align:start position:0% +kinematics easily and seamlessly +translates to three dimensions that's + + align:start position:0% +translates to three dimensions that's + + + align:start position:0% +translates to three dimensions that's +the beauty of the way we do it okay so + + align:start position:0% +the beauty of the way we do it okay so + + + align:start position:0% +the beauty of the way we do it okay so +we'll do everything in 2D but you just + + align:start position:0% +we'll do everything in 2D but you just + + + align:start position:0% +we'll do everything in 2D but you just +go to 3D everything's fine with cross + + align:start position:0% +go to 3D everything's fine with cross + + + align:start position:0% +go to 3D everything's fine with cross +products dot products everything will be + + align:start position:0% +products dot products everything will be + + + align:start position:0% +products dot products everything will be +the same okay so these are the basis + + align:start position:0% +the same okay so these are the basis + + + align:start position:0% +the same okay so these are the basis +vectors in the unit length and uh now so + + align:start position:0% +vectors in the unit length and uh now so + + + align:start position:0% +vectors in the unit length and uh now so +any Vector with respect to frame F can + + align:start position:0% +any Vector with respect to frame F can + + + align:start position:0% +any Vector with respect to frame F can +be using these basis vectors can be + + align:start position:0% +be using these basis vectors can be + + + align:start position:0% +be using these basis vectors can be +expressed as you know some something * + + align:start position:0% +expressed as you know some something * + + + align:start position:0% +expressed as you know some something * +FS1 plus something * FS2 right with + + align:start position:0% +FS1 plus something * FS2 right with + + + align:start position:0% +FS1 plus something * FS2 right with +respect to these basis vectors that be + + align:start position:0% +respect to these basis vectors that be + + + align:start position:0% +respect to these basis vectors that be +something * E1 something * + + align:start position:0% +something * E1 something * + + + align:start position:0% +something * E1 something * +E2 + + align:start position:0% +E2 + + + align:start position:0% +E2 +right I might come back to + + align:start position:0% + + + + align:start position:0% + +this okay let me ask you a question so + + align:start position:0% +this okay let me ask you a question so + + + align:start position:0% +this okay let me ask you a question so +let's say I pick a a frame f F1 oh sorry + + align:start position:0% + + + + align:start position:0% + +F and I take a vector R it's a little + + align:start position:0% +F and I take a vector R it's a little + + + align:start position:0% +F and I take a vector R it's a little +unit it's a little you know vector and I + + align:start position:0% +unit it's a little you know vector and I + + + align:start position:0% +unit it's a little you know vector and I +freeze it in that transparency I draw it + + align:start position:0% +freeze it in that transparency I draw it + + + align:start position:0% +freeze it in that transparency I draw it +can it ever change within the F + + align:start position:0% +can it ever change within the F + + + align:start position:0% +can it ever change within the F +frame if I draw it there right and I'm + + align:start position:0% +frame if I draw it there right and I'm + + + align:start position:0% +frame if I draw it there right and I'm +sitting on FR frame will I ever see + + align:start position:0% +sitting on FR frame will I ever see + + + align:start position:0% +sitting on FR frame will I ever see +change in length or + + align:start position:0% +change in length or + + + align:start position:0% +change in length or +Direction no but that same Vector if I'm + + align:start position:0% +Direction no but that same Vector if I'm + + + align:start position:0% +Direction no but that same Vector if I'm +sitting in the E frame I'm using moving + + align:start position:0% +sitting in the E frame I'm using moving + + + align:start position:0% +sitting in the E frame I'm using moving +the transparency around will it + + align:start position:0% +the transparency around will it + + + align:start position:0% +the transparency around will it +change right will the length change no + + align:start position:0% +change right will the length change no + + + align:start position:0% +change right will the length change no +but what will change its direction will + + align:start position:0% +but what will change its direction will + + + align:start position:0% +but what will change its direction will +change right so that means that a vector + + align:start position:0% +change right so that means that a vector + + + align:start position:0% +change right so that means that a vector +embedded in a frame will not change in + + align:start position:0% +embedded in a frame will not change in + + + align:start position:0% +embedded in a frame will not change in +that frame but with respect to some + + align:start position:0% +that frame but with respect to some + + + align:start position:0% +that frame but with respect to some +other frame it might change okay all + + align:start position:0% + + + + align:start position:0% + +right so here's what I'm going to say + + align:start position:0% +right so here's what I'm going to say + + + align:start position:0% +right so here's what I'm going to say +and then I'll explain this more by the + + align:start position:0% +and then I'll explain this more by the + + + align:start position:0% +and then I'll explain this more by the +time we're done with today's class and + + align:start position:0% +time we're done with today's class and + + + align:start position:0% +time we're done with today's class and +next week's class you'll understand this + + align:start position:0% +next week's class you'll understand this + + + align:start position:0% +next week's class you'll understand this +completely because we're going to do + + align:start position:0% +completely because we're going to do + + + align:start position:0% +completely because we're going to do +this in gory detail okay but bear with + + align:start position:0% +this in gory detail okay but bear with + + + align:start position:0% +this in gory detail okay but bear with +me we're going to make some a a few + + align:start position:0% +me we're going to make some a a few + + + align:start position:0% +me we're going to make some a a few +leaps here but when when we're done + + align:start position:0% +leaps here but when when we're done + + + align:start position:0% +leaps here but when when we're done +you'll you'll be completely totally cop + + align:start position:0% +you'll you'll be completely totally cop + + + align:start position:0% +you'll you'll be completely totally cop +pathetic with + + align:start position:0% + + + + align:start position:0% + +it oh sorry Miss Mis wrote + + align:start position:0% + + + + align:start position:0% + +by the way I haven't said anything + + align:start position:0% +by the way I haven't said anything + + + align:start position:0% +by the way I haven't said anything +profound yet everything is very + + align:start position:0% +profound yet everything is very + + + align:start position:0% +profound yet everything is very +intuitive right I haven't said anything + + align:start position:0% +intuitive right I haven't said anything + + + align:start position:0% +intuitive right I haven't said anything +special so you're not missing anything + + align:start position:0% +special so you're not missing anything + + + align:start position:0% +special so you're not missing anything +I'm just going slowly we'll gather speed + + align:start position:0% +I'm just going slowly we'll gather speed + + + align:start position:0% +I'm just going slowly we'll gather speed +in a + + align:start position:0% + + + + align:start position:0% + +minute and I'm going to say this in a + + align:start position:0% +minute and I'm going to say this in a + + + align:start position:0% +minute and I'm going to say this in a +I'm going to say what I just said in + + align:start position:0% +I'm going to say what I just said in + + + align:start position:0% +I'm going to say what I just said in +English in a slight more mathematical + + align:start position:0% + + + + align:start position:0% + +way okay so so now I'm going to write + + align:start position:0% +way okay so so now I'm going to write + + + align:start position:0% +way okay so so now I'm going to write +something for you which might seem a + + align:start position:0% +something for you which might seem a + + + align:start position:0% +something for you which might seem a +little odd but this is the thing you + + align:start position:0% +little odd but this is the thing you + + + align:start position:0% +little odd but this is the thing you +need to get once you get this all of + + align:start position:0% +need to get once you get this all of + + + align:start position:0% +need to get once you get this all of +kinematics is is + + align:start position:0% + + + + align:start position:0% + +Breeze d by DT + + align:start position:0% +Breeze d by DT + + + align:start position:0% +Breeze d by DT +of a vector fixed in a frame let's let's + + align:start position:0% +of a vector fixed in a frame let's let's + + + align:start position:0% +of a vector fixed in a frame let's let's +consider frame F which give me an + + align:start position:0% +consider frame F which give me an + + + align:start position:0% +consider frame F which give me an +example of a vector that's fixed in + + align:start position:0% +example of a vector that's fixed in + + + align:start position:0% +example of a vector that's fixed in +frame + + align:start position:0% + + + + align:start position:0% + +f um oh yeah actually give it to me in + + align:start position:0% +f um oh yeah actually give it to me in + + + align:start position:0% +f um oh yeah actually give it to me in +terms give me make up a vector that's + + align:start position:0% +terms give me make up a vector that's + + + align:start position:0% +terms give me make up a vector that's +fixed in terms of you know B1 B2 F1 F2 + + align:start position:0% +fixed in terms of you know B1 B2 F1 F2 + + + align:start position:0% +fixed in terms of you know B1 B2 F1 F2 +in terms of frame + + align:start position:0% + + + + align:start position:0% + +F it's it's an odd question yeah huh vs + + align:start position:0% +F it's it's an odd question yeah huh vs + + + align:start position:0% +F it's it's an odd question yeah huh vs +vs is a velocity right it could be fixed + + align:start position:0% +vs is a velocity right it could be fixed + + + align:start position:0% +vs is a velocity right it could be fixed +let me actually let let me just tell you + + align:start position:0% +let me actually let let me just tell you + + + align:start position:0% +let me actually let let me just tell you +is this Vector fixed in frame this is f + + align:start position:0% +is this Vector fixed in frame this is f + + + align:start position:0% +is this Vector fixed in frame this is f +is Vector F1 fixed in frame F yeah what + + align:start position:0% +is Vector F1 fixed in frame F yeah what + + + align:start position:0% +is Vector F1 fixed in frame F yeah what +about this + + align:start position:0% +about this + + + align:start position:0% +about this +Vector is this fixed in frame + + align:start position:0% +Vector is this fixed in frame + + + align:start position:0% +Vector is this fixed in frame +one yes right so any Vector which can be + + align:start position:0% +one yes right so any Vector which can be + + + align:start position:0% +one yes right so any Vector which can be +written as in terms of the basis vectors + + align:start position:0% +written as in terms of the basis vectors + + + align:start position:0% +written as in terms of the basis vectors +and constant numbers is fixed in the + + align:start position:0% +and constant numbers is fixed in the + + + align:start position:0% +and constant numbers is fixed in the +frame F right so any Vector + + align:start position:0% +frame F right so any Vector + + + align:start position:0% +frame F right so any Vector +r that is fixed in frame M I'll just + + align:start position:0% +r that is fixed in frame M I'll just + + + align:start position:0% +r that is fixed in frame M I'll just +call it R right + + align:start position:0% + + + + align:start position:0% + +now + + align:start position:0% +now + + + align:start position:0% +now +where R is + + align:start position:0% +where R is + + + align:start position:0% +where R is +fixed in + + align:start position:0% + + + + align:start position:0% + +F here's what I'm going to say d by DT + + align:start position:0% +F here's what I'm going to say d by DT + + + align:start position:0% +F here's what I'm going to say d by DT +of that R is equal + + align:start position:0% + + + + align:start position:0% + +to zero I haven't told you precisely + + align:start position:0% +to zero I haven't told you precisely + + + align:start position:0% +to zero I haven't told you precisely +what this D by DT is I'll explain it to + + align:start position:0% +what this D by DT is I'll explain it to + + + align:start position:0% +what this D by DT is I'll explain it to +you right but you know that that Vector + + align:start position:0% +you right but you know that that Vector + + + align:start position:0% +you right but you know that that Vector +if it's fixed in in frame F if I take + + align:start position:0% +if it's fixed in in frame F if I take + + + align:start position:0% +if it's fixed in in frame F if I take +the derivative it should be zero right + + align:start position:0% +the derivative it should be zero right + + + align:start position:0% +the derivative it should be zero right +it ain't changing isn't moving + + align:start position:0% + + + + align:start position:0% + +right now if I take this derivative of + + align:start position:0% +right now if I take this derivative of + + + align:start position:0% +right now if I take this derivative of +that same Vector not in the frame of the + + align:start position:0% +that same Vector not in the frame of the + + + align:start position:0% +that same Vector not in the frame of the +frisbe but in the frame of the earth is + + align:start position:0% +frisbe but in the frame of the earth is + + + align:start position:0% +frisbe but in the frame of the earth is +it going to be + + align:start position:0% +it going to be + + + align:start position:0% +it going to be +zero no so I need to have some way of + + align:start position:0% +zero no so I need to have some way of + + + align:start position:0% +zero no so I need to have some way of +saying listen I'm taking this derivative + + align:start position:0% +saying listen I'm taking this derivative + + + align:start position:0% +saying listen I'm taking this derivative +in frame F not in frame + + align:start position:0% +in frame F not in frame + + + align:start position:0% +in frame F not in frame +earth right how would I denote that + + align:start position:0% + + + + align:start position:0% + +very good so for example I could put a + + align:start position:0% +very good so for example I could put a + + + align:start position:0% +very good so for example I could put a +parenthesis and a little F like this + + align:start position:0% +parenthesis and a little F like this + + + align:start position:0% +parenthesis and a little F like this +right to say listen I'm taking the + + align:start position:0% +right to say listen I'm taking the + + + align:start position:0% +right to say listen I'm taking the +derivative respect to frame F right I + + align:start position:0% +derivative respect to frame F right I + + + align:start position:0% +derivative respect to frame F right I +could do that but it turns out that + + align:start position:0% +could do that but it turns out that + + + align:start position:0% +could do that but it turns out that +a better convention is to Simply write + + align:start position:0% +a better convention is to Simply write + + + align:start position:0% +a better convention is to Simply write +the frame of reference + + align:start position:0% + + + + align:start position:0% + +here okay so when you see something like + + align:start position:0% +here okay so when you see something like + + + align:start position:0% +here okay so when you see something like +that this is the way to read it in + + align:start position:0% +that this is the way to read it in + + + align:start position:0% +that this is the way to read it in +English the derivative of vector r with + + align:start position:0% +English the derivative of vector r with + + + align:start position:0% +English the derivative of vector r with +respect to frame F and if I tell you + + align:start position:0% +respect to frame F and if I tell you + + + align:start position:0% +respect to frame F and if I tell you +that derivative that R is fixed in F the + + align:start position:0% +that derivative that R is fixed in F the + + + align:start position:0% +that derivative that R is fixed in F the +statement I'm making is that derivative + + align:start position:0% +statement I'm making is that derivative + + + align:start position:0% +statement I'm making is that derivative +is zero got + + align:start position:0% +is zero got + + + align:start position:0% +is zero got +it makes sense any questions I insist on + + align:start position:0% +it makes sense any questions I insist on + + + align:start position:0% +it makes sense any questions I insist on +at least one question at this point I + + align:start position:0% +at least one question at this point I + + + align:start position:0% +at least one question at this point I +get tired I need you know I need a break + + align:start position:0% +get tired I need you know I need a break + + + align:start position:0% +get tired I need you know I need a break +anyone yes thank you what's your name + + align:start position:0% +anyone yes thank you what's your name + + + align:start position:0% +anyone yes thank you what's your name +Rachel Rachel + + align:start position:0% +Rachel Rachel + + + align:start position:0% +Rachel Rachel +two is that what two under the f it's + + align:start position:0% +two is that what two under the f it's + + + align:start position:0% +two is that what two under the f it's +actually just wasn't even meant to be a + + align:start position:0% +actually just wasn't even meant to be a + + + align:start position:0% +actually just wasn't even meant to be a +line it's not a vector it's just a frame + + align:start position:0% +line it's not a vector it's just a frame + + + align:start position:0% +line it's not a vector it's just a frame +so it's just a capital letter thank + + align:start position:0% +so it's just a capital letter thank + + + align:start position:0% +so it's just a capital letter thank +you right f is just the name of a frame + + align:start position:0% +you right f is just the name of a frame + + + align:start position:0% +you right f is just the name of a frame +I could call it Rachel right Rachel + + align:start position:0% +I could call it Rachel right Rachel + + + align:start position:0% +I could call it Rachel right Rachel +right yeah so I could call it Rachel I + + align:start position:0% +right yeah so I could call it Rachel I + + + align:start position:0% +right yeah so I could call it Rachel I +just call it f just a name okay any + + align:start position:0% +just call it f just a name okay any + + + align:start position:0% +just call it f just a name okay any +other + + align:start position:0% +other + + + align:start position:0% +other +questions anyone else it's oppressive + + align:start position:0% +questions anyone else it's oppressive + + + align:start position:0% +questions anyone else it's oppressive +and yeah we should call facilities and + + align:start position:0% +and yeah we should call facilities and + + + align:start position:0% +and yeah we should call facilities and +figure out how to turn the air + + align:start position:0% +figure out how to turn the air + + + align:start position:0% +figure out how to turn the air +conditioning or open the window or + + align:start position:0% +conditioning or open the window or + + + align:start position:0% +conditioning or open the window or +something so if you remind me I'll call + + align:start position:0% +something so if you remind me I'll call + + + align:start position:0% +something so if you remind me I'll call +them later thanks okay so that's all the + + align:start position:0% +them later thanks okay so that's all the + + + align:start position:0% +them later thanks okay so that's all the +RIS of frames when you look at one frame + + align:start position:0% +RIS of frames when you look at one frame + + + align:start position:0% +RIS of frames when you look at one frame +and now the fun starts because now we're + + align:start position:0% +and now the fun starts because now we're + + + align:start position:0% +and now the fun starts because now we're +going to start looking at taking + + align:start position:0% +going to start looking at taking + + + align:start position:0% +going to start looking at taking +derivatives and looking at stuff across + + align:start position:0% +derivatives and looking at stuff across + + + align:start position:0% +derivatives and looking at stuff across +frames all right and once I do that + + align:start position:0% +frames all right and once I do that + + + align:start position:0% +frames all right and once I do that +we'll jump into the Frisbee problem + + align:start position:0% +we'll jump into the Frisbee problem + + + align:start position:0% +we'll jump into the Frisbee problem +we'll nail it it's a 1010 about + + align:start position:0% +we'll nail it it's a 1010 about + + + align:start position:0% +we'll nail it it's a 1010 about +105 uh we might not finish the Frisbee + + align:start position:0% +105 uh we might not finish the Frisbee + + + align:start position:0% +105 uh we might not finish the Frisbee +problem we'll certainly set it up and + + align:start position:0% +problem we'll certainly set it up and + + + align:start position:0% +problem we'll certainly set it up and +start doing some of the math and U we'll + + align:start position:0% +start doing some of the math and U we'll + + + align:start position:0% +start doing some of the math and U we'll +finish it off worst case next class + + align:start position:0% +finish it off worst case next class + + + align:start position:0% +finish it off worst case next class +okay okay so now let's look at + + align:start position:0% + + + + align:start position:0% + +multiple + + align:start position:0% + + + + align:start position:0% + +frames + + align:start position:0% + + + + align:start position:0% + +so I'm going to call it multiple but + + align:start position:0% +so I'm going to call it multiple but + + + align:start position:0% +so I'm going to call it multiple but +we'll always look at pairs of frames two + + align:start position:0% +we'll always look at pairs of frames two + + + align:start position:0% +we'll always look at pairs of frames two +frames right and if you can do the math + + align:start position:0% +frames right and if you can do the math + + + align:start position:0% +frames right and if you can do the math +across two frames three frames is just a + + align:start position:0% +across two frames three frames is just a + + + align:start position:0% +across two frames three frames is just a +chain of two frames right so we'll just + + align:start position:0% +chain of two frames right so we'll just + + + align:start position:0% +chain of two frames right so we'll just +look at two frames but we'll call it + + align:start position:0% +look at two frames but we'll call it + + + align:start position:0% +look at two frames but we'll call it +multiple because it goes to + + align:start position:0% + + + + align:start position:0% + +multiple + + align:start position:0% + + + + align:start position:0% + +okay so imagine one + + align:start position:0% +okay so imagine one + + + align:start position:0% +okay so imagine one +transparency or one frame which is + + align:start position:0% +transparency or one frame which is + + + align:start position:0% +transparency or one frame which is +planet Earth + + align:start position:0% + + + + align:start position:0% + +let's attach a basis Vector to it a + + align:start position:0% +let's attach a basis Vector to it a + + + align:start position:0% +let's attach a basis Vector to it a +basis or basis vectors to + + align:start position:0% + + + + align:start position:0% + +it + + align:start position:0% +it + + + align:start position:0% +it +E1 and + + align:start position:0% + + + + align:start position:0% + +E2 + + align:start position:0% + + + + align:start position:0% + +okay now let's think of another + + align:start position:0% + + + + align:start position:0% + +frame frame B1 B I'm sorry actually we + + align:start position:0% +frame frame B1 B I'm sorry actually we + + + align:start position:0% +frame frame B1 B I'm sorry actually we +called it f for frisbe right so we call + + align:start position:0% +called it f for frisbe right so we call + + + align:start position:0% +called it f for frisbe right so we call +it f + + align:start position:0% + + + + align:start position:0% + +what are the basis vectors in + + align:start position:0% +what are the basis vectors in + + + align:start position:0% +what are the basis vectors in +f f and + + align:start position:0% + + + + align:start position:0% + +F2 + + align:start position:0% +F2 + + + align:start position:0% +F2 +okay first + + align:start position:0% + + + + align:start position:0% + +question can you write E1 and E2 in + + align:start position:0% +question can you write E1 and E2 in + + + align:start position:0% +question can you write E1 and E2 in +terms of F1 and F2 or F1 and F2 in terms + + align:start position:0% +terms of F1 and F2 or F1 and F2 in terms + + + align:start position:0% +terms of F1 and F2 or F1 and F2 in terms +of E1 and E2 2 yes yes what do you need + + align:start position:0% +of E1 and E2 2 yes yes what do you need + + + align:start position:0% +of E1 and E2 2 yes yes what do you need +to tell me what E1 and E2 are in terms + + align:start position:0% +to tell me what E1 and E2 are in terms + + + align:start position:0% +to tell me what E1 and E2 are in terms +of F1 and + + align:start position:0% +of F1 and + + + align:start position:0% +of F1 and +F2 the starts with an A the angle right + + align:start position:0% +F2 the starts with an A the angle right + + + align:start position:0% +F2 the starts with an A the angle right +so now one of the things I'm going to do + + align:start position:0% +so now one of the things I'm going to do + + + align:start position:0% +so now one of the things I'm going to do +in this class especially because uh + + align:start position:0% +in this class especially because uh + + + align:start position:0% +in this class especially because uh +we're going to do a lot of stuff and I + + align:start position:0% +we're going to do a lot of stuff and I + + + align:start position:0% +we're going to do a lot of stuff and I +want to keep you guys engaged is I'm + + align:start position:0% +want to keep you guys engaged is I'm + + + align:start position:0% +want to keep you guys engaged is I'm +going to have these snap quizzes AJ may + + align:start position:0% +going to have these snap quizzes AJ may + + + align:start position:0% +going to have these snap quizzes AJ may +have explained the snap quiz to you but + + align:start position:0% +have explained the snap quiz to you but + + + align:start position:0% +have explained the snap quiz to you but +the way the snap quizes work is we look + + align:start position:0% +the way the snap quizes work is we look + + + align:start position:0% +the way the snap quizes work is we look +at them and we make sure you put in some + + align:start position:0% +at them and we make sure you put in some + + + align:start position:0% +at them and we make sure you put in some +effort + + align:start position:0% +effort + + + align:start position:0% +effort +and we absolutely don't penalize you for + + align:start position:0% +and we absolutely don't penalize you for + + + align:start position:0% +and we absolutely don't penalize you for +making any mistakes in fact we penalize + + align:start position:0% +making any mistakes in fact we penalize + + + align:start position:0% +making any mistakes in fact we penalize +ourselves we don't penalize ourselves + + align:start position:0% +ourselves we don't penalize ourselves + + + align:start position:0% +ourselves we don't penalize ourselves +but we you + + align:start position:0% +but we you + + + align:start position:0% +but we you +know we uh see what we succeeded in + + align:start position:0% +know we uh see what we succeeded in + + + align:start position:0% +know we uh see what we succeeded in +transmitting all right so here's what I + + align:start position:0% +transmitting all right so here's what I + + + align:start position:0% +transmitting all right so here's what I +want you to do and some of these snap + + align:start position:0% +want you to do and some of these snap + + + align:start position:0% +want you to do and some of these snap +goers are we haven't it's not like we're + + align:start position:0% +goers are we haven't it's not like we're + + + align:start position:0% +goers are we haven't it's not like we're +asking you to recall something we're + + align:start position:0% +asking you to recall something we're + + + align:start position:0% +asking you to recall something we're +actually asking you to look ahead here's + + align:start position:0% +actually asking you to look ahead here's + + + align:start position:0% +actually asking you to look ahead here's +a snap quiz I want you to write for me + + align:start position:0% +a snap quiz I want you to write for me + + + align:start position:0% +a snap quiz I want you to write for me +fub1 and F2 in terms of E1 and E2 is you + + align:start position:0% +fub1 and F2 in terms of E1 and E2 is you + + + align:start position:0% +fub1 and F2 in terms of E1 and E2 is you +this + + align:start position:0% +this + + + align:start position:0% +this +angle is Theta and this is basic + + align:start position:0% + + + + align:start position:0% + +trigonometric yes pull out a sheet of + + align:start position:0% +trigonometric yes pull out a sheet of + + + align:start position:0% +trigonometric yes pull out a sheet of +paper write your name on top and have a + + align:start position:0% +paper write your name on top and have a + + + align:start position:0% +paper write your name on top and have a +go at it and we'll collect at the end of + + align:start position:0% +go at it and we'll collect at the end of + + + align:start position:0% +go at it and we'll collect at the end of +class yes + + align:start position:0% +class yes + + + align:start position:0% +class yes +sorry the angle is the very good so let + + align:start position:0% +sorry the angle is the very good so let + + + align:start position:0% +sorry the angle is the very good so let +me explain I have defined Theta I could + + align:start position:0% +me explain I have defined Theta I could + + + align:start position:0% +me explain I have defined Theta I could +have defined it any way I could you know + + align:start position:0% +have defined it any way I could you know + + + align:start position:0% +have defined it any way I could you know +because I'm the professor I can do what + + align:start position:0% +because I'm the professor I can do what + + + align:start position:0% +because I'm the professor I can do what +I want you know you know it works but + + align:start position:0% +I want you know you know it works but + + + align:start position:0% +I want you know you know it works but +anyway it's the angle between F1 and E1 + + align:start position:0% +anyway it's the angle between F1 and E1 + + + align:start position:0% +anyway it's the angle between F1 and E1 +at a snapshot in time at an instant in + + align:start position:0% +at a snapshot in time at an instant in + + + align:start position:0% +at a snapshot in time at an instant in +time I'm calling it Theta and I want you + + align:start position:0% +time I'm calling it Theta and I want you + + + align:start position:0% +time I'm calling it Theta and I want you +to tell me what FS1 and F2 are in terms + + align:start position:0% +to tell me what FS1 and F2 are in terms + + + align:start position:0% +to tell me what FS1 and F2 are in terms +of E1 and E E2 as a function of + + align:start position:0% +of E1 and E E2 as a function of + + + align:start position:0% +of E1 and E E2 as a function of +theta + + align:start position:0% +theta + + + align:start position:0% +theta +y1 F1 and F2 are both unit vectors e and + + align:start position:0% +y1 F1 and F2 are both unit vectors e and + + + align:start position:0% +y1 F1 and F2 are both unit vectors e and +E2 unit vectors + + align:start position:0% + + + + align:start position:0% + +okay for + + align:start position:0% + + + + align:start position:0% + +yeah I want you to write so I want you + + align:start position:0% +yeah I want you to write so I want you + + + align:start position:0% +yeah I want you to write so I want you +to write something like fub1 is equal + + align:start position:0% +to write something like fub1 is equal + + + align:start position:0% +to write something like fub1 is equal +to something E1 plus something E2 F2 is + + align:start position:0% +to something E1 plus something E2 F2 is + + + align:start position:0% +to something E1 plus something E2 F2 is +equal to something E1 plus something E2 + + align:start position:0% +equal to something E1 plus something E2 + + + align:start position:0% +equal to something E1 plus something E2 +that's what it'll come out looking like + + align:start position:0% +that's what it'll come out looking like + + + align:start position:0% +that's what it'll come out looking like +and it might have a few SS and cosine + + align:start position:0% +and it might have a few SS and cosine + + + align:start position:0% +and it might have a few SS and cosine +thetas floating + + align:start position:0% +thetas floating + + + align:start position:0% +thetas floating +around in fact it better have some sin + + align:start position:0% +around in fact it better have some sin + + + align:start position:0% +around in fact it better have some sin +thetas and cosine thetas right + + align:start position:0% + + + + align:start position:0% + +and by the way we will put up a handout + + align:start position:0% +and by the way we will put up a handout + + + align:start position:0% +and by the way we will put up a handout +um has it been put up yet AJ will the uh + + align:start position:0% +um has it been put up yet AJ will the uh + + + align:start position:0% +um has it been put up yet AJ will the uh +um kinematics PDF we'll put it up like + + align:start position:0% +um kinematics PDF we'll put it up like + + + align:start position:0% +um kinematics PDF we'll put it up like +today or tomorrow which explains all + + align:start position:0% +today or tomorrow which explains all + + + align:start position:0% +today or tomorrow which explains all +this all right I'll tell you about the + + align:start position:0% +this all right I'll tell you about the + + + align:start position:0% +this all right I'll tell you about the +book in a minute when you're done with + + align:start position:0% +book in a minute when you're done with + + + align:start position:0% +book in a minute when you're done with +the quiz + + align:start position:0% + + + + align:start position:0% + +yep um it's just fub1 equals to cinea E1 + + align:start position:0% +yep um it's just fub1 equals to cinea E1 + + + align:start position:0% +yep um it's just fub1 equals to cinea E1 +ah hold up up okay yeah good yeah I get + + align:start position:0% +ah hold up up okay yeah good yeah I get + + + align:start position:0% +ah hold up up okay yeah good yeah I get +it I know it's easy good I want you to + + align:start position:0% +it I know it's easy good I want you to + + + align:start position:0% +it I know it's easy good I want you to +know it's easy but I want everyone to + + align:start position:0% +know it's easy but I want everyone to + + + align:start position:0% +know it's easy but I want everyone to +know + + align:start position:0% +know + + + align:start position:0% +know +it good what's your + + align:start position:0% +it good what's your + + + align:start position:0% +it good what's your +name Joe what's your full name Joe + + align:start position:0% +name Joe what's your full name Joe + + + align:start position:0% +name Joe what's your full name Joe +kurri k h o u r y kurri + + align:start position:0% + + + + align:start position:0% + +excellent only because Joe is a common + + align:start position:0% +excellent only because Joe is a common + + + align:start position:0% +excellent only because Joe is a common +name so you know + + align:start position:0% + + + + align:start position:0% + +there's a Dean at MIT I think he's still + + align:start position:0% +there's a Dean at MIT I think he's still + + + align:start position:0% +there's a Dean at MIT I think he's still +a Dean right with your last name yeah + + align:start position:0% +a Dean right with your last name yeah + + + align:start position:0% +a Dean right with your last name yeah +Phil + + align:start position:0% + + + + align:start position:0% + +cury okay everyone + + align:start position:0% +cury okay everyone + + + align:start position:0% +cury okay everyone +done + + align:start position:0% +done + + + align:start position:0% +done +another 90 seconds it doesn't matter if + + align:start position:0% +another 90 seconds it doesn't matter if + + + align:start position:0% +another 90 seconds it doesn't matter if +you don't get it once I write it down + + align:start position:0% +you don't get it once I write it down + + + align:start position:0% +you don't get it once I write it down +you'll get it I want you to put in the + + align:start position:0% +you'll get it I want you to put in the + + + align:start position:0% +you'll get it I want you to put in the +effort of trying that's all + + align:start position:0% + + + + align:start position:0% + +I'll tell people that with things like + + align:start position:0% +I'll tell people that with things like + + + align:start position:0% +I'll tell people that with things like +this it really helps to grit your + + align:start position:0% + + + + align:start position:0% + +teeth doesn't really I'm just + + align:start position:0% + + + + align:start position:0% + +conf got it got it + + align:start position:0% +conf got it got it + + + align:start position:0% +conf got it got it +okay 10 + + align:start position:0% + + + + align:start position:0% + +seconds all righty we're done anyone Joe + + align:start position:0% +seconds all righty we're done anyone Joe + + + align:start position:0% +seconds all righty we're done anyone Joe +what's F1 and F2 in terms of E1 and E2 + + align:start position:0% +what's F1 and F2 in terms of E1 and E2 + + + align:start position:0% +what's F1 and F2 in terms of E1 and E2 +F1 is uh cosine th E1 plus sin Theta E2 + + align:start position:0% + + + + align:start position:0% + +is um F2 = + + align:start position:0% +is um F2 = + + + align:start position:0% +is um F2 = +to- sin thet + + align:start position:0% + + + + align:start position:0% + +want + + align:start position:0% + + + + align:start position:0% + +plus does did everyone get + + align:start position:0% +plus does did everyone get + + + align:start position:0% +plus does did everyone get +this + + align:start position:0% +this + + + align:start position:0% +this +yeah be + + align:start position:0% +yeah be + + + align:start position:0% +yeah be +normalized + + align:start position:0% +normalized + + + align:start position:0% +normalized +um they would automatically be yes they + + align:start position:0% +um they would automatically be yes they + + + align:start position:0% +um they would automatically be yes they +should + + align:start position:0% +should + + + align:start position:0% +should +think about it right no no think about + + align:start position:0% +think about it right no no think about + + + align:start position:0% +think about it right no no think about +it so the the question so first of all + + align:start position:0% +it so the the question so first of all + + + align:start position:0% +it so the the question so first of all +let me come back it's a great thought + + align:start position:0% +let me come back it's a great thought + + + align:start position:0% +let me come back it's a great thought +hold that thought all right does do + + align:start position:0% +hold that thought all right does do + + + align:start position:0% +hold that thought all right does do +people agree with this AJ is this + + align:start position:0% +people agree with this AJ is this + + + align:start position:0% +people agree with this AJ is this +correct a is a + + align:start position:0% +correct a is a + + + align:start position:0% +correct a is a +TA he wasn't looking okay that's fine + + align:start position:0% +TA he wasn't looking okay that's fine + + + align:start position:0% +TA he wasn't looking okay that's fine +let me look at my notes and confirm okay + + align:start position:0% +let me look at my notes and confirm okay + + + align:start position:0% +let me look at my notes and confirm okay +F1 and F2 that's correct excellent okay + + align:start position:0% +F1 and F2 that's correct excellent okay + + + align:start position:0% +F1 and F2 that's correct excellent okay +so what's your name r r how do you spell + + align:start position:0% +so what's your name r r how do you spell + + + align:start position:0% +so what's your name r r how do you spell +it r a n e + + align:start position:0% +it r a n e + + + align:start position:0% +it r a n e +R any excellent rain so the question + + align:start position:0% +R any excellent rain so the question + + + align:start position:0% +R any excellent rain so the question +rain is asking is look fub1 and F2 are + + align:start position:0% +rain is asking is look fub1 and F2 are + + + align:start position:0% +rain is asking is look fub1 and F2 are +unit + + align:start position:0% +unit + + + align:start position:0% +unit +vectors E1 and E2 are unit vectors I'm + + align:start position:0% +vectors E1 and E2 are unit vectors I'm + + + align:start position:0% +vectors E1 and E2 are unit vectors I'm +assuming this is what you're asking so + + align:start position:0% +assuming this is what you're asking so + + + align:start position:0% +assuming this is what you're asking so +obviously this better be a unit Vector + + align:start position:0% +obviously this better be a unit Vector + + + align:start position:0% +obviously this better be a unit Vector +right but as it turns out if you + + align:start position:0% +right but as it turns out if you + + + align:start position:0% +right but as it turns out if you +transform between unit vectors what + + align:start position:0% +transform between unit vectors what + + + align:start position:0% +transform between unit vectors what +comes out will end up being magnitude + + align:start position:0% +comes out will end up being magnitude + + + align:start position:0% +comes out will end up being magnitude +one and the reason is that if you take + + align:start position:0% +one and the reason is that if you take + + + align:start position:0% +one and the reason is that if you take +the magnitude of this you get cosine + + align:start position:0% +the magnitude of this you get cosine + + + align:start position:0% +the magnitude of this you get cosine +Square theta plus sin Square Theta which + + align:start position:0% +Square theta plus sin Square Theta which + + + align:start position:0% +Square theta plus sin Square Theta which +will be one so it'll kind of self + + align:start position:0% +will be one so it'll kind of self + + + align:start position:0% +will be one so it'll kind of self +normalize get it + + align:start position:0% + + + + align:start position:0% + +did people understand what I just said + + align:start position:0% +did people understand what I just said + + + align:start position:0% +did people understand what I just said +right so this is correct any questions + + align:start position:0% +right so this is correct any questions + + + align:start position:0% +right so this is correct any questions +about + + align:start position:0% +about + + + align:start position:0% +about +this do you does anyone want to know how + + align:start position:0% +this do you does anyone want to know how + + + align:start position:0% +this do you does anyone want to know how +I got this it takes a lot of courage to + + align:start position:0% +I got this it takes a lot of courage to + + + align:start position:0% +I got this it takes a lot of courage to +say yes and I'll show you you want me to + + align:start position:0% +say yes and I'll show you you want me to + + + align:start position:0% +say yes and I'll show you you want me to +show you okay it's very simple right in + + align:start position:0% +show you okay it's very simple right in + + + align:start position:0% +show you okay it's very simple right in +the if you think of it the following way + + align:start position:0% +the if you think of it the following way + + + align:start position:0% +the if you think of it the following way +I'll I'll do it below all + + align:start position:0% +I'll I'll do it below all + + + align:start position:0% +I'll I'll do it below all +right I'll do it here by the way this is + + align:start position:0% +right I'll do it here by the way this is + + + align:start position:0% +right I'll do it here by the way this is +a terrible classroom I apologize so you + + align:start position:0% +a terrible classroom I apologize so you + + + align:start position:0% +a terrible classroom I apologize so you +can't see stuff from a distance just hey + + align:start position:0% +can't see stuff from a distance just hey + + + align:start position:0% +can't see stuff from a distance just hey +call me and I'll you know I'll try and + + align:start position:0% +call me and I'll you know I'll try and + + + align:start position:0% +call me and I'll you know I'll try and +make it bigger so + + align:start position:0% + + + + align:start position:0% + +fub1 + + align:start position:0% +fub1 + + + align:start position:0% +fub1 +right + + align:start position:0% + + + + align:start position:0% + +FS2 and we're trying to calculate F1 and + + align:start position:0% +FS2 and we're trying to calculate F1 and + + + align:start position:0% +FS2 and we're trying to calculate F1 and +F2 in terms + + align:start position:0% +F2 in terms + + + align:start position:0% +F2 in terms +of + + align:start position:0% + + + + align:start position:0% + +E1 and + + align:start position:0% + + + + align:start position:0% + +E2 right so the way we would do it + + align:start position:0% +E2 right so the way we would do it + + + align:start position:0% +E2 right so the way we would do it +is there are a couple ways to do it one + + align:start position:0% +is there are a couple ways to do it one + + + align:start position:0% +is there are a couple ways to do it one +is you can just take components and add + + align:start position:0% +is you can just take components and add + + + align:start position:0% +is you can just take components and add +them + + align:start position:0% +them + + + align:start position:0% +them +up right so one of the things you could + + align:start position:0% +up right so one of the things you could + + + align:start position:0% +up right so one of the things you could +do is you could say listen um F1 is + + align:start position:0% +do is you could say listen um F1 is + + + align:start position:0% +do is you could say listen um F1 is +composed of this component of + + align:start position:0% +composed of this component of + + + align:start position:0% +composed of this component of +E2 and + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% + + + + align:start position:0% + +um how would I do it that's an easy way + + align:start position:0% +um how would I do it that's an easy way + + + align:start position:0% +um how would I do it that's an easy way +to say this + + align:start position:0% + + + + align:start position:0% + +yeah or yeah I could do the other way + + align:start position:0% +yeah or yeah I could do the other way + + + align:start position:0% +yeah or yeah I could do the other way +right + + align:start position:0% +right + + + align:start position:0% +right +right so I can take the projection of F1 + + align:start position:0% +right so I can take the projection of F1 + + + align:start position:0% +right so I can take the projection of F1 +on E1 and take the projection of F1 on + + align:start position:0% +on E1 and take the projection of F1 on + + + align:start position:0% +on E1 and take the projection of F1 on +E2 get it what's your name ER Erica + + align:start position:0% +E2 get it what's your name ER Erica + + + align:start position:0% +E2 get it what's your name ER Erica +right I can just take the projection of + + align:start position:0% +right I can just take the projection of + + + align:start position:0% +right I can just take the projection of +fub1 on E1 and E2 right and just use the + + align:start position:0% +fub1 on E1 and E2 right and just use the + + + align:start position:0% +fub1 on E1 and E2 right and just use the +these thetas right and then take the + + align:start position:0% +these thetas right and then take the + + + align:start position:0% +these thetas right and then take the +projection of F2 on E1 E2 and then write + + align:start position:0% +projection of F2 on E1 E2 and then write + + + align:start position:0% +projection of F2 on E1 E2 and then write +that's what you get okay I don't want to + + align:start position:0% +that's what you get okay I don't want to + + + align:start position:0% +that's what you get okay I don't want to +do it only because I uh I can show it + + align:start position:0% +do it only because I uh I can show it + + + align:start position:0% +do it only because I uh I can show it +you after class it's just very very + + align:start position:0% +you after class it's just very very + + + align:start position:0% +you after class it's just very very +basically just add the projections and + + align:start position:0% +basically just add the projections and + + + align:start position:0% +basically just add the projections and +you'll get that it's in the + + align:start position:0% +you'll get that it's in the + + + align:start position:0% +you'll get that it's in the +notes okay what is E1 and E2 in terms of + + align:start position:0% +notes okay what is E1 and E2 in terms of + + + align:start position:0% +notes okay what is E1 and E2 in terms of +F1 and + + align:start position:0% + + + + align:start position:0% + +F2 what's a quick way to do + + align:start position:0% + + + + align:start position:0% + +this H yeah you could solve it or + + align:start position:0% +this H yeah you could solve it or + + + align:start position:0% +this H yeah you could solve it or +there's another way to do it which is if + + align:start position:0% +there's another way to do it which is if + + + align:start position:0% +there's another way to do it which is if +you put yourself in F1 and f2s if you + + align:start position:0% +you put yourself in F1 and f2s if you + + + align:start position:0% +you put yourself in F1 and f2s if you +kind of turn it around if it's like + + align:start position:0% +kind of turn it around if it's like + + + align:start position:0% +kind of turn it around if it's like +replacing Theta with a minus + + align:start position:0% +replacing Theta with a minus + + + align:start position:0% +replacing Theta with a minus +Theta right so if you replace Theta with + + align:start position:0% +Theta right so if you replace Theta with + + + align:start position:0% +Theta right so if you replace Theta with +a minus Theta what you'll get is + + align:start position:0% + + + + align:start position:0% + +got it so this is how you go back and + + align:start position:0% +got it so this is how you go back and + + + align:start position:0% +got it so this is how you go back and +forth between two frames and as long as + + align:start position:0% +forth between two frames and as long as + + + align:start position:0% +forth between two frames and as long as +you know the angle between the frames + + align:start position:0% +you know the angle between the frames + + + align:start position:0% +you know the angle between the frames +right now here's the deal if this + + align:start position:0% +right now here's the deal if this + + + align:start position:0% +right now here's the deal if this +Frame is rotating with respect to this + + align:start position:0% +Frame is rotating with respect to this + + + align:start position:0% +Frame is rotating with respect to this +Frame the Theta will change but at any + + align:start position:0% +Frame the Theta will change but at any + + + align:start position:0% +Frame the Theta will change but at any +given point in time if you know what the + + align:start position:0% +given point in time if you know what the + + + align:start position:0% +given point in time if you know what the +Theta is Binger you can calculate fub1 + + align:start position:0% +Theta is Binger you can calculate fub1 + + + align:start position:0% +Theta is Binger you can calculate fub1 +from F1 and F2 in terms of E1 and E2 and + + align:start position:0% +from F1 and F2 in terms of E1 and E2 and + + + align:start position:0% +from F1 and F2 in terms of E1 and E2 and +vice + + align:start position:0% +vice + + + align:start position:0% +vice +ver okay any questions about this + + align:start position:0% + + + + align:start position:0% + +yep + + align:start position:0% + + + + align:start position:0% + +yes you will but it's many more steps so + + align:start position:0% +yes you will but it's many more steps so + + + align:start position:0% +yes you will but it's many more steps so +we'll come to that we'll nail the spider + + align:start position:0% +we'll come to that we'll nail the spider + + + align:start position:0% +we'll come to that we'll nail the spider +now all right okay but this is how you + + align:start position:0% +now all right okay but this is how you + + + align:start position:0% +now all right okay but this is how you +trans transform between + + align:start position:0% +trans transform between + + + align:start position:0% +trans transform between +frames okay so now the notes go there + + align:start position:0% + + + + align:start position:0% + +okay now I'm going to tell you something + + align:start position:0% +okay now I'm going to tell you something + + + align:start position:0% +okay now I'm going to tell you something +which will seem like an empty trick and + + align:start position:0% +which will seem like an empty trick and + + + align:start position:0% +which will seem like an empty trick and +then we'll do the spider problem and + + align:start position:0% +then we'll do the spider problem and + + + align:start position:0% +then we'll do the spider problem and +it'll make + + align:start position:0% + + + + align:start position:0% + +sense now let's assume that we have some + + align:start position:0% +sense now let's assume that we have some + + + align:start position:0% +sense now let's assume that we have some +Vector r + + align:start position:0% + + + + align:start position:0% + +I'm trying to thread the needle here I'm + + align:start position:0% +I'm trying to thread the needle here I'm + + + align:start position:0% +I'm trying to thread the needle here I'm +just + + align:start position:0% + + + + align:start position:0% + +thinking whether I should give you the + + align:start position:0% +thinking whether I should give you the + + + align:start position:0% +thinking whether I should give you the +conceptual Point + + align:start position:0% + + + + align:start position:0% + +first okay let's just jump into the + + align:start position:0% +first okay let's just jump into the + + + align:start position:0% +first okay let's just jump into the +spider problem and then we'll because a + + align:start position:0% +spider problem and then we'll because a + + + align:start position:0% +spider problem and then we'll because a +lot of people asked about how solving + + align:start position:0% +lot of people asked about how solving + + + align:start position:0% +lot of people asked about how solving +that getting the velocity let's just do + + align:start position:0% +that getting the velocity let's just do + + + align:start position:0% +that getting the velocity let's just do +that now and then I'll make the final + + align:start position:0% +that now and then I'll make the final + + + align:start position:0% +that now and then I'll make the final +point I want to make after that okay so + + align:start position:0% +point I want to make after that okay so + + + align:start position:0% +point I want to make after that okay so +this is how you translate between frames + + align:start position:0% +this is how you translate between frames + + + align:start position:0% +this is how you translate between frames +this is how you transform between frames + + align:start position:0% +this is how you transform between frames + + + align:start position:0% +this is how you transform between frames +and we're all set so now we have all the + + align:start position:0% +and we're all set so now we have all the + + + align:start position:0% +and we're all set so now we have all the +math we need there's one little trick I + + align:start position:0% +math we need there's one little trick I + + + align:start position:0% +math we need there's one little trick I +want to tell you which I'll tell you now + + align:start position:0% +want to tell you which I'll tell you now + + + align:start position:0% +want to tell you which I'll tell you now +in the context of the spider problem and + + align:start position:0% +in the context of the spider problem and + + + align:start position:0% +in the context of the spider problem and +now what we're going to do is actually + + align:start position:0% +now what we're going to do is actually + + + align:start position:0% +now what we're going to do is actually +try and figure out what the velocity and + + align:start position:0% +try and figure out what the velocity and + + + align:start position:0% +try and figure out what the velocity and +acceleration of that spider are all + + align:start position:0% +acceleration of that spider are all + + + align:start position:0% +acceleration of that spider are all +right so let's do that okay so this is + + align:start position:0% +right so let's do that okay so this is + + + align:start position:0% +right so let's do that okay so this is +the corner of the + + align:start position:0% +the corner of the + + + align:start position:0% +the corner of the +room right this is the room and um in + + align:start position:0% +room right this is the room and um in + + + align:start position:0% +room right this is the room and um in +the in the corner of the room I have two + + align:start position:0% +the in the corner of the room I have two + + + align:start position:0% +the in the corner of the room I have two +two unit vectors let's make them a + + align:start position:0% +two unit vectors let's make them a + + + align:start position:0% +two unit vectors let's make them a +little shorter these are too + + align:start position:0% +little shorter these are too + + + align:start position:0% +little shorter these are too +long right uh we'll call them E and F + + align:start position:0% +long right uh we'll call them E and F + + + align:start position:0% +long right uh we'll call them E and F +just because we've been using that for + + align:start position:0% +just because we've been using that for + + + align:start position:0% +just because we've been using that for +Earth and + + align:start position:0% +Earth and + + + align:start position:0% +Earth and +frisbee right + + align:start position:0% +frisbee right + + + align:start position:0% +frisbee right +e and this is our + + align:start position:0% +e and this is our + + + align:start position:0% +e and this is our +frisbee we call that + + align:start position:0% +frisbee we call that + + + align:start position:0% +frisbee we call that +F and it's + + align:start position:0% + + + + align:start position:0% + +spinning we call these + + align:start position:0% +spinning we call these + + + align:start position:0% +spinning we call these +fub1 and FS2 so first question to your + + align:start position:0% +fub1 and FS2 so first question to your + + + align:start position:0% +fub1 and FS2 so first question to your +folks the first thing you need to do by + + align:start position:0% +folks the first thing you need to do by + + + align:start position:0% +folks the first thing you need to do by +the way actually as a comment is when + + align:start position:0% +the way actually as a comment is when + + + align:start position:0% +the way actually as a comment is when +you draw a picture like this you must + + align:start position:0% +you draw a picture like this you must + + + align:start position:0% +you draw a picture like this you must +always go out of your way to label + + align:start position:0% +always go out of your way to label + + + align:start position:0% +always go out of your way to label +points that are of importance so for + + align:start position:0% +points that are of importance so for + + + align:start position:0% +points that are of importance so for +example this point we'll call it + + align:start position:0% +example this point we'll call it + + + align:start position:0% +example this point we'll call it +P right it's just a point P I could have + + align:start position:0% +P right it's just a point P I could have + + + align:start position:0% +P right it's just a point P I could have +called it C center of the Frisbee let's + + align:start position:0% +called it C center of the Frisbee let's + + + align:start position:0% +called it C center of the Frisbee let's +call the position of the spider s now + + align:start position:0% +call the position of the spider s now + + + align:start position:0% +call the position of the spider s now +have I lost any generality in claiming + + align:start position:0% +have I lost any generality in claiming + + + align:start position:0% +have I lost any generality in claiming +that the spider is along this unit basis + + align:start position:0% +that the spider is along this unit basis + + + align:start position:0% +that the spider is along this unit basis +Vector have a lot I haven't right + + align:start position:0% +Vector have a lot I haven't right + + + align:start position:0% +Vector have a lot I haven't right +because I picked them arbitrarily so + + align:start position:0% +because I picked them arbitrarily so + + + align:start position:0% +because I picked them arbitrarily so +might as well just pick that okay let us + + align:start position:0% +might as well just pick that okay let us + + + align:start position:0% +might as well just pick that okay let us +call now actually even before that so + + align:start position:0% +call now actually even before that so + + + align:start position:0% +call now actually even before that so +here's the question to + + align:start position:0% +here's the question to + + + align:start position:0% +here's the question to +you how do I parameterize the position + + align:start position:0% +you how do I parameterize the position + + + align:start position:0% +you how do I parameterize the position +of the spider at any given moment in + + align:start position:0% +of the spider at any given moment in + + + align:start position:0% +of the spider at any given moment in +time what do I need to know to tell you + + align:start position:0% +time what do I need to know to tell you + + + align:start position:0% +time what do I need to know to tell you +where the spider is right + + align:start position:0% + + + + align:start position:0% + +now say + + align:start position:0% + + + + align:start position:0% + +loudly the relationship of F1 to + + align:start position:0% +loudly the relationship of F1 to + + + align:start position:0% +loudly the relationship of F1 to +reference frame e + + align:start position:0% +reference frame e + + + align:start position:0% +reference frame e +and what would that relationship + + align:start position:0% +and what would that relationship + + + align:start position:0% +and what would that relationship +be think about what do you need to + + align:start position:0% + + + + align:start position:0% + +know excellent okay so one parameter you + + align:start position:0% +know excellent okay so one parameter you + + + align:start position:0% +know excellent okay so one parameter you +need for sure is this angle + + align:start position:0% +need for sure is this angle + + + align:start position:0% +need for sure is this angle +right which is Theta which we just used + + align:start position:0% +right which is Theta which we just used + + + align:start position:0% +right which is Theta which we just used +up + + align:start position:0% +up + + + align:start position:0% +up +there what else do you need to + + align:start position:0% +there what else do you need to + + + align:start position:0% +there what else do you need to +parameterize if I want you you to give + + align:start position:0% +parameterize if I want you you to give + + + align:start position:0% +parameterize if I want you you to give +me the exact coordinates of the spider + + align:start position:0% +me the exact coordinates of the spider + + + align:start position:0% +me the exact coordinates of the spider +what are the numbers do I need + + align:start position:0% + + + + align:start position:0% + +yep now if I know the angle + + align:start position:0% +yep now if I know the angle + + + align:start position:0% +yep now if I know the angle +but I know it is a function of time then + + align:start position:0% +but I know it is a function of time then + + + align:start position:0% +but I know it is a function of time then +that's one parameter what are the other + + align:start position:0% +that's one parameter what are the other + + + align:start position:0% +that's one parameter what are the other +parameters I + + align:start position:0% +parameters I + + + align:start position:0% +parameters I +need don't think of motion yet just + + align:start position:0% +need don't think of motion yet just + + + align:start position:0% +need don't think of motion yet just +think of like a + + align:start position:0% +think of like a + + + align:start position:0% +think of like a +snapshot right just give me distances + + align:start position:0% +snapshot right just give me distances + + + align:start position:0% +snapshot right just give me distances +we'll get to Velocity right see this + + align:start position:0% +we'll get to Velocity right see this + + + align:start position:0% +we'll get to Velocity right see this +this is what I want you to think through + + align:start position:0% +this is what I want you to think through + + + align:start position:0% +this is what I want you to think through +velocities are derivatives of location + + align:start position:0% +velocities are derivatives of location + + + align:start position:0% +velocities are derivatives of location +so go ahead distance exactly so what + + align:start position:0% +so go ahead distance exactly so what + + + align:start position:0% +so go ahead distance exactly so what +else do we need we need the distance of + + align:start position:0% +else do we need we need the distance of + + + align:start position:0% +else do we need we need the distance of +this point P from some point embedded on + + align:start position:0% +this point P from some point embedded on + + + align:start position:0% +this point P from some point embedded on +the earth it doesn't matter which point + + align:start position:0% +the earth it doesn't matter which point + + + align:start position:0% +the earth it doesn't matter which point +we pick we need to pick one point that's + + align:start position:0% +we pick we need to pick one point that's + + + align:start position:0% +we pick we need to pick one point that's +embedded on the Earth right so I'm just + + align:start position:0% +embedded on the Earth right so I'm just + + + align:start position:0% +embedded on the Earth right so I'm just +going to pick one point at the corner of + + align:start position:0% +going to pick one point at the corner of + + + align:start position:0% +going to pick one point at the corner of +these two where I've drawn these axes it + + align:start position:0% +these two where I've drawn these axes it + + + align:start position:0% +these two where I've drawn these axes it +doesn't matter I got have picked it here + + align:start position:0% +doesn't matter I got have picked it here + + + align:start position:0% +doesn't matter I got have picked it here +uh I'll call that point O So this + + align:start position:0% +uh I'll call that point O So this + + + align:start position:0% +uh I'll call that point O So this +distance I'm going to call it + + align:start position:0% +distance I'm going to call it + + + align:start position:0% +distance I'm going to call it +U and what else do I + + align:start position:0% +U and what else do I + + + align:start position:0% +U and what else do I +need it's two + + align:start position:0% +need it's two + + + align:start position:0% +need it's two +Dimensions I need the vertical + + align:start position:0% +Dimensions I need the vertical + + + align:start position:0% +Dimensions I need the vertical +distance I'm going to call that + + align:start position:0% + + + + align:start position:0% + +V what else do I need come on quick + + align:start position:0% + + + + align:start position:0% + +excellent I need this + + align:start position:0% +excellent I need this + + + align:start position:0% +excellent I need this +distance and I'm making the making this + + align:start position:0% +distance and I'm making the making this + + + align:start position:0% +distance and I'm making the making this +up as I go I'll call that + + align:start position:0% +up as I go I'll call that + + + align:start position:0% +up as I go I'll call that +L + + align:start position:0% +L + + + align:start position:0% +L +okay now and this is something you + + align:start position:0% +okay now and this is something you + + + align:start position:0% +okay now and this is something you +should do every time you solve a problem + + align:start position:0% +should do every time you solve a problem + + + align:start position:0% +should do every time you solve a problem +like + + align:start position:0% +like + + + align:start position:0% +like +this what is the position of the spider + + align:start position:0% +this what is the position of the spider + + + align:start position:0% +this what is the position of the spider +with respect to that point we picked on + + align:start position:0% +with respect to that point we picked on + + + align:start position:0% +with respect to that point we picked on +the surface of the Earth which we call O + + align:start position:0% + + + + align:start position:0% + +anybody okay this is so watch this I'm + + align:start position:0% +anybody okay this is so watch this I'm + + + align:start position:0% +anybody okay this is so watch this I'm +going to call it R all that thought okay + + align:start position:0% +going to call it R all that thought okay + + + align:start position:0% +going to call it R all that thought okay +I'm just going to write it out first the + + align:start position:0% +I'm just going to write it out first the + + + align:start position:0% +I'm just going to write it out first the +the position Vector from o to P which is + + align:start position:0% +the position Vector from o to P which is + + + align:start position:0% +the position Vector from o to P which is +the vector this + + align:start position:0% +the vector this + + + align:start position:0% +the vector this +Vector right that + + align:start position:0% +Vector right that + + + align:start position:0% +Vector right that +Vector get + + align:start position:0% +Vector get + + + align:start position:0% +Vector get +it right is equal to r o is equal to + + align:start position:0% +it right is equal to r o is equal to + + + align:start position:0% +it right is equal to r o is equal to +what go + + align:start position:0% + + + + align:start position:0% + +ahead well no no you're no keep going U + + align:start position:0% +ahead well no no you're no keep going U + + + align:start position:0% +ahead well no no you're no keep going U +plus plus L cosine but don't do I need + + align:start position:0% +plus plus L cosine but don't do I need + + + align:start position:0% +plus plus L cosine but don't do I need +some uh L cosine Theta right yeah yeah + + align:start position:0% +some uh L cosine Theta right yeah yeah + + + align:start position:0% +some uh L cosine Theta right yeah yeah +yeah okay you going to write like this + + align:start position:0% +yeah okay you going to write like this + + + align:start position:0% +yeah okay you going to write like this +U plus L cosine + + align:start position:0% + + + + align:start position:0% + +Theta E1 + + align:start position:0% + + + + align:start position:0% + +okay that's perfectly correct + + align:start position:0% +okay that's perfectly correct + + + align:start position:0% +okay that's perfectly correct +yep I'm sorry that's s yeah a position + + align:start position:0% +yep I'm sorry that's s yeah a position + + + align:start position:0% +yep I'm sorry that's s yeah a position +of spider right that's what he wrote I + + align:start position:0% +of spider right that's what he wrote I + + + align:start position:0% +of spider right that's what he wrote I +beg you pardon right so that's exactly + + align:start position:0% +beg you pardon right so that's exactly + + + align:start position:0% +beg you pardon right so that's exactly +correct say it + + align:start position:0% + + + + align:start position:0% + +again that should be V yeah okay so you + + align:start position:0% +again that should be V yeah okay so you + + + align:start position:0% +again that should be V yeah okay so you +actually that's perfectly correct you + + align:start position:0% +actually that's perfectly correct you + + + align:start position:0% +actually that's perfectly correct you +did it right but now I'm going to give + + align:start position:0% +did it right but now I'm going to give + + + align:start position:0% +did it right but now I'm going to give +you a slightly different way to think + + align:start position:0% +you a slightly different way to think + + + align:start position:0% +you a slightly different way to think +about it which will lead to the same + + align:start position:0% +about it which will lead to the same + + + align:start position:0% +about it which will lead to the same +answer you did a shortcut in your head + + align:start position:0% +answer you did a shortcut in your head + + + align:start position:0% +answer you did a shortcut in your head +which is brilliant right but I'm going + + align:start position:0% +which is brilliant right but I'm going + + + align:start position:0% +which is brilliant right but I'm going +to give you a different way to think + + align:start position:0% +to give you a different way to think + + + align:start position:0% +to give you a different way to think +about it which is a little more + + align:start position:0% +about it which is a little more + + + align:start position:0% +about it which is a little more +methodical but which also brings out the + + align:start position:0% +methodical but which also brings out the + + + align:start position:0% +methodical but which also brings out the +point I want to make to + + align:start position:0% +point I want to make to + + + align:start position:0% +point I want to make to +you I'm going to write this + + align:start position:0% +you I'm going to write this + + + align:start position:0% +you I'm going to write this +differently that was right I'm going to + + align:start position:0% +differently that was right I'm going to + + + align:start position:0% +differently that was right I'm going to +write it + + align:start position:0% +write it + + + align:start position:0% +write it +differently I'm going to write this + + align:start position:0% +differently I'm going to write this + + + align:start position:0% +differently I'm going to write this +Vector R + + align:start position:0% +Vector R + + + align:start position:0% +Vector R +oos as equal to + + align:start position:0% +oos as equal to + + + align:start position:0% +oos as equal to +because I'm not as + + align:start position:0% +because I'm not as + + + align:start position:0% +because I'm not as +smart r + + align:start position:0% +smart r + + + align:start position:0% +smart r +o plus r PS is this fair I can do that + + align:start position:0% +o plus r PS is this fair I can do that + + + align:start position:0% +o plus r PS is this fair I can do that +right break it them into two + + align:start position:0% +right break it them into two + + + align:start position:0% +right break it them into two +pieces now then I'm going to + + align:start position:0% +pieces now then I'm going to + + + align:start position:0% +pieces now then I'm going to +say r o p is + + align:start position:0% +say r o p is + + + align:start position:0% +say r o p is +simply U + + align:start position:0% +simply U + + + align:start position:0% +simply U +E1 plus v + + align:start position:0% +E1 plus v + + + align:start position:0% +E1 plus v +E2 that's this guy + + align:start position:0% +E2 that's this guy + + + align:start position:0% +E2 that's this guy +is that + + align:start position:0% + + + + align:start position:0% + +correct am I going too fast do you see + + align:start position:0% +correct am I going too fast do you see + + + align:start position:0% +correct am I going too fast do you see +what I'm doing + + align:start position:0% +what I'm doing + + + align:start position:0% +what I'm doing +here + + align:start position:0% +here + + + align:start position:0% +here +everybody + + align:start position:0% +everybody + + + align:start position:0% +everybody +yeah and what is r PS and here's the rub + + align:start position:0% +yeah and what is r PS and here's the rub + + + align:start position:0% +yeah and what is r PS and here's the rub +I'm going to write it + + align:start position:0% +I'm going to write it + + + align:start position:0% +I'm going to write it +as get + + align:start position:0% +as get + + + align:start position:0% +as get +this l + + align:start position:0% + + + + align:start position:0% + +does that make you + + align:start position:0% +does that make you + + + align:start position:0% +does that make you +queasy right makes you queasy + + align:start position:0% + + + + align:start position:0% + +right it's like putting uh you know + + align:start position:0% +right it's like putting uh you know + + + align:start position:0% +right it's like putting uh you know +strawberry ice cream on a cheese + + align:start position:0% +strawberry ice cream on a cheese + + + align:start position:0% +strawberry ice cream on a cheese +sandwich + + align:start position:0% +sandwich + + + align:start position:0% +sandwich +yeah my daughter my daughter did that + + align:start position:0% +yeah my daughter my daughter did that + + + align:start position:0% +yeah my daughter my daughter did that +exra this morning so + + align:start position:0% +exra this morning so + + + align:start position:0% +exra this morning so +yeah oh I'm sorry that's probably what + + align:start position:0% +yeah oh I'm sorry that's probably what + + + align:start position:0% +yeah oh I'm sorry that's probably what +made you + + align:start position:0% + + + + align:start position:0% + +squeasy and in this way now does this + + align:start position:0% +squeasy and in this way now does this + + + align:start position:0% +squeasy and in this way now does this +make you + + align:start position:0% +make you + + + align:start position:0% +make you +queasy no it doesn't make it that should + + align:start position:0% +queasy no it doesn't make it that should + + + align:start position:0% +queasy no it doesn't make it that should +still make you queasy think about it + + align:start position:0% +still make you queasy think about it + + + align:start position:0% +still make you queasy think about it +anti- mixing basis + + align:start position:0% + + + + align:start position:0% + +bases is that okay can iic + + align:start position:0% +bases is that okay can iic + + + align:start position:0% +bases is that okay can iic +bases yes no okay all in favor all + + align:start position:0% +bases yes no okay all in favor all + + + align:start position:0% +bases yes no okay all in favor all +against okay I set the all against up I + + align:start position:0% +against okay I set the all against up I + + + align:start position:0% +against okay I set the all against up I +I was misleading you it turns out no + + align:start position:0% +I was misleading you it turns out no + + + align:start position:0% +I was misleading you it turns out no +it's my fault buty you I wanted to + + align:start position:0% +it's my fault buty you I wanted to + + + align:start position:0% +it's my fault buty you I wanted to +wanted to kind of expose any hidden + + align:start position:0% +wanted to kind of expose any hidden + + + align:start position:0% +wanted to kind of expose any hidden +latent queasiness is + + align:start position:0% +latent queasiness is + + + align:start position:0% +latent queasiness is +right it's okay it's okay to mix bases + + align:start position:0% +right it's okay it's okay to mix bases + + + align:start position:0% +right it's okay it's okay to mix bases +absolutely okay + + align:start position:0% +absolutely okay + + + align:start position:0% +absolutely okay +yep find them up there in terms of each + + align:start position:0% +yep find them up there in terms of each + + + align:start position:0% +yep find them up there in terms of each +other yeah well it's okay because even + + align:start position:0% +other yeah well it's okay because even + + + align:start position:0% +other yeah well it's okay because even +if I didn't Define them it's a vector + + align:start position:0% +if I didn't Define them it's a vector + + + align:start position:0% +if I didn't Define them it's a vector +right I can add vectors it's perfectly + + align:start position:0% +right I can add vectors it's perfectly + + + align:start position:0% +right I can add vectors it's perfectly +okay even if they're different bases + + align:start position:0% +okay even if they're different bases + + + align:start position:0% +okay even if they're different bases +that's okay right so what you did was + + align:start position:0% +that's okay right so what you did was + + + align:start position:0% +that's okay right so what you did was +you can of downon converted everything + + align:start position:0% +you can of downon converted everything + + + align:start position:0% +you can of downon converted everything +to E1 and E2 right but I'm taking the + + align:start position:0% +to E1 and E2 right but I'm taking the + + + align:start position:0% +to E1 and E2 right but I'm taking the +lazy approach which is I'm going to + + align:start position:0% +lazy approach which is I'm going to + + + align:start position:0% +lazy approach which is I'm going to +write them like this just because you'll + + align:start position:0% +write them like this just because you'll + + + align:start position:0% +write them like this just because you'll +see in the class certain things come out + + align:start position:0% +see in the class certain things come out + + + align:start position:0% +see in the class certain things come out +if you write it this way but what you + + align:start position:0% +if you write it this way but what you + + + align:start position:0% +if you write it this way but what you +did was perfectly right in fact I'm + + align:start position:0% +did was perfectly right in fact I'm + + + align:start position:0% +did was perfectly right in fact I'm +going to do what you just said in a + + align:start position:0% +going to do what you just said in a + + + align:start position:0% +going to do what you just said in a +moment + + align:start position:0% +moment + + + align:start position:0% +moment +now here's the deal what is the + + align:start position:0% +now here's the deal what is the + + + align:start position:0% +now here's the deal what is the +velocity + + align:start position:0% +velocity + + + align:start position:0% +velocity +of the center of the + + align:start position:0% + + + + align:start position:0% + +Frisbee first of all that's an + + align:start position:0% +Frisbee first of all that's an + + + align:start position:0% +Frisbee first of all that's an +incomplete question I haven't asked I + + align:start position:0% +incomplete question I haven't asked I + + + align:start position:0% +incomplete question I haven't asked I +haven't told you everything you need to + + align:start position:0% +haven't told you everything you need to + + + align:start position:0% +haven't told you everything you need to +know but what's the velocity of the + + align:start position:0% +know but what's the velocity of the + + + align:start position:0% +know but what's the velocity of the +center of the + + align:start position:0% + + + + align:start position:0% + +Frisbee + + align:start position:0% +Frisbee + + + align:start position:0% +Frisbee +what I I can't hear + + align:start position:0% +what I I can't hear + + + align:start position:0% +what I I can't hear +you no no you might have said it right I + + align:start position:0% +you no no you might have said it right I + + + align:start position:0% +you no no you might have said it right I +really could everyone spoke I'm ten so + + align:start position:0% +really could everyone spoke I'm ten so + + + align:start position:0% +really could everyone spoke I'm ten so +you need to speak louder what what was + + align:start position:0% +you need to speak louder what what was + + + align:start position:0% +you need to speak louder what what was +incomplete about the question I just + + align:start position:0% +incomplete about the question I just + + + align:start position:0% +incomplete about the question I just +asked I said what's the velocity of the + + align:start position:0% +asked I said what's the velocity of the + + + align:start position:0% +asked I said what's the velocity of the +center of the Frisbee yep I didn't tell + + align:start position:0% +center of the Frisbee yep I didn't tell + + + align:start position:0% +center of the Frisbee yep I didn't tell +you a reference frame right so what's + + align:start position:0% +you a reference frame right so what's + + + align:start position:0% +you a reference frame right so what's +the velocity of the center of the frisbe + + align:start position:0% +the velocity of the center of the frisbe + + + align:start position:0% +the velocity of the center of the frisbe +with respect to planet + + align:start position:0% +with respect to planet + + + align:start position:0% +with respect to planet +Earth + + align:start position:0% +Earth + + + align:start position:0% +Earth +yes yeah so this is how I'm going to + + align:start position:0% +yes yeah so this is how I'm going to + + + align:start position:0% +yes yeah so this is how I'm going to +write + + align:start position:0% +write + + + align:start position:0% +write +velocity with respect to planet Earth a + + align:start position:0% +velocity with respect to planet Earth a + + + align:start position:0% +velocity with respect to planet Earth a +sorry sorry + + align:start position:0% +sorry sorry + + + align:start position:0% +sorry sorry +e right the velocity V of which point + + align:start position:0% + + + + align:start position:0% + +P right this notation is very important + + align:start position:0% +P right this notation is very important + + + align:start position:0% +P right this notation is very important +if I just said the velocity of Point P + + align:start position:0% +if I just said the velocity of Point P + + + align:start position:0% +if I just said the velocity of Point P +it makes no sense because I could be + + align:start position:0% +it makes no sense because I could be + + + align:start position:0% +it makes no sense because I could be +asking the velocity of Point p with + + align:start position:0% +asking the velocity of Point p with + + + align:start position:0% +asking the velocity of Point p with +respect to the Frisbee which would be + + align:start position:0% +respect to the Frisbee which would be + + + align:start position:0% +respect to the Frisbee which would be +zero right right so the velocity of + + align:start position:0% +zero right right so the velocity of + + + align:start position:0% +zero right right so the velocity of +Point p with respect to + + align:start position:0% +Point p with respect to + + + align:start position:0% +Point p with respect to +Earth is equal to D by + + align:start position:0% +Earth is equal to D by + + + align:start position:0% +Earth is equal to D by +DT of r p is that complete or am I + + align:start position:0% +DT of r p is that complete or am I + + + align:start position:0% +DT of r p is that complete or am I +missing something + + align:start position:0% + + + + align:start position:0% + +there any someone in the back someone on + + align:start position:0% +there any someone in the back someone on + + + align:start position:0% +there any someone in the back someone on +the that + + align:start position:0% +the that + + + align:start position:0% +the that +quadrant the way I wrote d by DTM I'm + + align:start position:0% +quadrant the way I wrote d by DTM I'm + + + align:start position:0% +quadrant the way I wrote d by DTM I'm +missing something + + align:start position:0% +missing something + + + align:start position:0% +missing something +here yeah I need to say from here on + + align:start position:0% +here yeah I need to say from here on + + + align:start position:0% +here yeah I need to say from here on +when you take a derivative which we + + align:start position:0% +when you take a derivative which we + + + align:start position:0% +when you take a derivative which we +still need to completely define I need + + align:start position:0% +still need to completely define I need + + + align:start position:0% +still need to completely define I need +to tell you which frame I'm taking the + + align:start position:0% +to tell you which frame I'm taking the + + + align:start position:0% +to tell you which frame I'm taking the +derivative with respect + + align:start position:0% +derivative with respect + + + align:start position:0% +derivative with respect +to + + align:start position:0% + + + + align:start position:0% + +okay and + + align:start position:0% + + + + align:start position:0% + +I I should have written Ro I'm still a + + align:start position:0% +I I should have written Ro I'm still a + + + align:start position:0% +I I should have written Ro I'm still a +little rusty I've been gone for the + + align:start position:0% +little rusty I've been gone for the + + + align:start position:0% +little rusty I've been gone for the +summer so I'm making mistakes but you + + align:start position:0% +summer so I'm making mistakes but you + + + align:start position:0% +summer so I'm making mistakes but you +caught me that's good + + align:start position:0% +caught me that's good + + + align:start position:0% +caught me that's good +yep do you need the second with respect + + align:start position:0% +yep do you need the second with respect + + + align:start position:0% +yep do you need the second with respect +to why do I need the + + align:start position:0% + + + + align:start position:0% + +second this one that's a beautiful + + align:start position:0% +second this one that's a beautiful + + + align:start position:0% +second this one that's a beautiful +question and hold that thought and + + align:start position:0% +question and hold that thought and + + + align:start position:0% +question and hold that thought and +remind me if I don't get back to it + + align:start position:0% +remind me if I don't get back to it + + + align:start position:0% +remind me if I don't get back to it +that's a great question okay but you can + + align:start position:0% +that's a great question okay but you can + + + align:start position:0% +that's a great question okay but you can +see that it doesn't hurt to write it + + align:start position:0% +see that it doesn't hurt to write it + + + align:start position:0% +see that it doesn't hurt to write it +it's complete it turns out that if I + + align:start position:0% +it's complete it turns out that if I + + + align:start position:0% +it's complete it turns out that if I +flip the frames it might look correct + + align:start position:0% +flip the frames it might look correct + + + align:start position:0% +flip the frames it might look correct +but it'll turn out to be wrong okay well + + align:start position:0% +but it'll turn out to be wrong okay well + + + align:start position:0% +but it'll turn out to be wrong okay well +what's your name Sam Sam all right I'll + + align:start position:0% +what's your name Sam Sam all right I'll + + + align:start position:0% +what's your name Sam Sam all right I'll +remember I'll remember that and we'll + + align:start position:0% +remember I'll remember that and we'll + + + align:start position:0% +remember I'll remember that and we'll +come back to that and what is the + + align:start position:0% +come back to that and what is the + + + align:start position:0% +come back to that and what is the +velocity of the spider how do I write + + align:start position:0% +velocity of the spider how do I write + + + align:start position:0% +velocity of the spider how do I write +the velocity of the spider with respect + + align:start position:0% +the velocity of the spider with respect + + + align:start position:0% +the velocity of the spider with respect +to the + + align:start position:0% +to the + + + align:start position:0% +to the +Earth + + align:start position:0% +Earth + + + align:start position:0% +Earth +quick + + align:start position:0% +quick + + + align:start position:0% +quick +e v s is equal to + + align:start position:0% +e v s is equal to + + + align:start position:0% +e v s is equal to +come + + align:start position:0% + + + + align:start position:0% + +on E DT let me raise this of r o + + align:start position:0% +on E DT let me raise this of r o + + + align:start position:0% +on E DT let me raise this of r o +p oh r + + align:start position:0% +p oh r + + + align:start position:0% +p oh r +s which is the same as e d by + + align:start position:0% + + + + align:start position:0% + +DT r + + align:start position:0% +DT r + + + align:start position:0% +DT r +o plus e d by + + align:start position:0% +o plus e d by + + + align:start position:0% +o plus e d by +DT r + + align:start position:0% + + + + align:start position:0% + +PS + + align:start position:0% +PS + + + align:start position:0% +PS +right so I've done nothing differently + + align:start position:0% +right so I've done nothing differently + + + align:start position:0% +right so I've done nothing differently +than what Sam did but I'm just doing it + + align:start position:0% +than what Sam did but I'm just doing it + + + align:start position:0% +than what Sam did but I'm just doing it +in more painstaking way that's all + + align:start position:0% +in more painstaking way that's all + + + align:start position:0% +in more painstaking way that's all +nothing + + align:start position:0% +nothing + + + align:start position:0% +nothing +special okay I'm going to raise this up + + align:start position:0% +special okay I'm going to raise this up + + + align:start position:0% +special okay I'm going to raise this up +there and go to go back to these + + align:start position:0% +there and go to go back to these + + + align:start position:0% +there and go to go back to these +boards and finish + + align:start position:0% + + + + align:start position:0% + +up this is very simple stuff so you're + + align:start position:0% +up this is very simple stuff so you're + + + align:start position:0% +up this is very simple stuff so you're +not missing anything if you if you're + + align:start position:0% +not missing anything if you if you're + + + align:start position:0% +not missing anything if you if you're +like what's it doing I know this it's + + align:start position:0% +like what's it doing I know this it's + + + align:start position:0% +like what's it doing I know this it's +okay I'm just doing it + + align:start position:0% +okay I'm just doing it + + + align:start position:0% +okay I'm just doing it +simply nothing + + align:start position:0% +simply nothing + + + align:start position:0% +simply nothing +profound okay so we're picking up + + align:start position:0% + + + + align:start position:0% + +here okay so let's go directly to this + + align:start position:0% +here okay so let's go directly to this + + + align:start position:0% +here okay so let's go directly to this +guy let's analyze this guy I just broke + + align:start position:0% +guy let's analyze this guy I just broke + + + align:start position:0% +guy let's analyze this guy I just broke +it out there for you just to kind of get + + align:start position:0% +it out there for you just to kind of get + + + align:start position:0% +it out there for you just to kind of get +you + + align:start position:0% +you + + + align:start position:0% +you +to walk through it with me I'm going to + + align:start position:0% +to walk through it with me I'm going to + + + align:start position:0% +to walk through it with me I'm going to +expand on that so I'm going to take + + align:start position:0% +expand on that so I'm going to take + + + align:start position:0% +expand on that so I'm going to take +first + + align:start position:0% +first + + + align:start position:0% +first +this + + align:start position:0% +this + + + align:start position:0% +this +term + + align:start position:0% + + + + align:start position:0% + +okay okay + + align:start position:0% +okay okay + + + align:start position:0% +okay okay +e d by + + align:start position:0% + + + + align:start position:0% + +DT R + + align:start position:0% +DT R + + + align:start position:0% +DT R +oos and what is r oos it's UE E1 sorry R + + align:start position:0% +oos and what is r oos it's UE E1 sorry R + + + align:start position:0% +oos and what is r oos it's UE E1 sorry R +I'm sorry r o p right this is r o it's U + + align:start position:0% +I'm sorry r o p right this is r o it's U + + + align:start position:0% +I'm sorry r o p right this is r o it's U +E1 + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +yes what do I do now + + align:start position:0% +yes what do I do now + + + align:start position:0% +yes what do I do now +yes that's an equal to + + align:start position:0% +yes that's an equal to + + + align:start position:0% +yes that's an equal to +no that was a kind of a stroke I'm + + align:start position:0% +no that was a kind of a stroke I'm + + + align:start position:0% +no that was a kind of a stroke I'm +writing like this it's kind of hard I'm + + align:start position:0% +writing like this it's kind of hard I'm + + + align:start position:0% +writing like this it's kind of hard I'm +trying to say Blackboard but it wasn't a + + align:start position:0% +trying to say Blackboard but it wasn't a + + + align:start position:0% +trying to say Blackboard but it wasn't a +negative okay is this + + align:start position:0% + + + + align:start position:0% + +good so what do I do now folks I'm + + align:start position:0% +good so what do I do now folks I'm + + + align:start position:0% +good so what do I do now folks I'm +simply trying to calculate this term + + align:start position:0% +simply trying to calculate this term + + + align:start position:0% +simply trying to calculate this term +what do I + + align:start position:0% + + + + align:start position:0% + +do very painstakingly I'm doing very + + align:start position:0% +do very painstakingly I'm doing very + + + align:start position:0% +do very painstakingly I'm doing very +slowly and + + align:start position:0% +slowly and + + + align:start position:0% +slowly and +painstakingly how do I take the + + align:start position:0% +painstakingly how do I take the + + + align:start position:0% +painstakingly how do I take the +derivatives and the vectors what do I do + + align:start position:0% + + + + align:start position:0% + +here say it again you want constant so + + align:start position:0% +here say it again you want constant so + + + align:start position:0% +here say it again you want constant so +you can pull those out exactly and + + align:start position:0% +you can pull those out exactly and + + + align:start position:0% +you can pull those out exactly and +shouldn't be constant exactly nailed it + + align:start position:0% +shouldn't be constant exactly nailed it + + + align:start position:0% +shouldn't be constant exactly nailed it +all right so I could think of as two + + align:start position:0% +all right so I could think of as two + + + align:start position:0% +all right so I could think of as two +ways one is I can do it by parts right + + align:start position:0% +ways one is I can do it by parts right + + + align:start position:0% +ways one is I can do it by parts right +so I can go e d by DT U * + + align:start position:0% +so I can go e d by DT U * + + + align:start position:0% +so I can go e d by DT U * +E1 plus u e by DT of E1 what is e d e DT + + align:start position:0% +E1 plus u e by DT of E1 what is e d e DT + + + align:start position:0% +E1 plus u e by DT of E1 what is e d e DT +of + + align:start position:0% +of + + + align:start position:0% +of +E1 zero right it's what a constant is + + align:start position:0% +E1 zero right it's what a constant is + + + align:start position:0% +E1 zero right it's what a constant is +right so this corresponds to Simply + + align:start position:0% + + + + align:start position:0% + +get + + align:start position:0% + + + + align:start position:0% + +it anyone good with + + align:start position:0% + + + + align:start position:0% + +this yes okay so that's that first term + + align:start position:0% +this yes okay so that's that first term + + + align:start position:0% +this yes okay so that's that first term +we just nailed this guy in excruciating + + align:start position:0% + + + + align:start position:0% + +detail now let's write this guy out + + align:start position:0% + + + + align:start position:0% + +is equal to + + align:start position:0% +is equal to + + + align:start position:0% +is equal to +what help me out you + + align:start position:0% + + + + align:start position:0% + +so what do I do here + + align:start position:0% +so what do I do here + + + align:start position:0% +so what do I do here +folks is F1 constant in + + align:start position:0% + + + + align:start position:0% + +E yes no no right so strictly speaking + + align:start position:0% +E yes no no right so strictly speaking + + + align:start position:0% +E yes no no right so strictly speaking +I'm in a bit of trouble here so what do + + align:start position:0% +I'm in a bit of trouble here so what do + + + align:start position:0% +I'm in a bit of trouble here so what do +I + + align:start position:0% + + + + align:start position:0% + +do Sam did that actually but he did it + + align:start position:0% +do Sam did that actually but he did it + + + align:start position:0% +do Sam did that actually but he did it +in he was right what should I + + align:start position:0% +in he was right what should I + + + align:start position:0% +in he was right what should I +do yeah yeah exactly so let's write it + + align:start position:0% +do yeah yeah exactly so let's write it + + + align:start position:0% +do yeah yeah exactly so let's write it +in terms of you know our wonderful trans + + align:start position:0% +in terms of you know our wonderful trans + + + align:start position:0% +in terms of you know our wonderful trans +transformation there those + + align:start position:0% +transformation there those + + + align:start position:0% +transformation there those +Transformations are very important by + + align:start position:0% +Transformations are very important by + + + align:start position:0% +Transformations are very important by +the way you need to nail them understand + + align:start position:0% +the way you need to nail them understand + + + align:start position:0% +the way you need to nail them understand +them okay and put them in your + + align:start position:0% +them okay and put them in your + + + align:start position:0% +them okay and put them in your +Sheets if if you know you in the exams + + align:start position:0% +Sheets if if you know you in the exams + + + align:start position:0% +Sheets if if you know you in the exams +we permit your sheets there are + + align:start position:0% +we permit your sheets there are + + + align:start position:0% +we permit your sheets there are +only tools we formulate that are + + align:start position:0% +only tools we formulate that are + + + align:start position:0% +only tools we formulate that are +important and that's that's kind of an + + align:start position:0% +important and that's that's kind of an + + + align:start position:0% +important and that's that's kind of an +important one these Transformations that + + align:start position:0% +important one these Transformations that + + + align:start position:0% +important one these Transformations that +we had down + + align:start position:0% +we had down + + + align:start position:0% +we had down +here those + + align:start position:0% +here those + + + align:start position:0% +here those +guys okay so these you should remember + + align:start position:0% +guys okay so these you should remember + + + align:start position:0% +guys okay so these you should remember +and understand them don't make mistakes + + align:start position:0% +and understand them don't make mistakes + + + align:start position:0% +and understand them don't make mistakes +there because they Cascade and screw + + align:start position:0% +there because they Cascade and screw + + + align:start position:0% +there because they Cascade and screw +everything else up okay so that is equal + + align:start position:0% +everything else up okay so that is equal + + + align:start position:0% +everything else up okay so that is equal +to expand it for me because I can't see + + align:start position:0% +to expand it for me because I can't see + + + align:start position:0% +to expand it for me because I can't see +it from here + + align:start position:0% + + + + align:start position:0% + +please come + + align:start position:0% + + + + align:start position:0% + +on + + align:start position:0% + + + + align:start position:0% + +plus + + align:start position:0% + + + + align:start position:0% + +sorry okay I'm going to raise that and + + align:start position:0% +sorry okay I'm going to raise that and + + + align:start position:0% +sorry okay I'm going to raise that and +finish it up here + + align:start position:0% +finish it up here + + + align:start position:0% +finish it up here +we're still calculating velocities + + align:start position:0% + + + + align:start position:0% + +right what did I do + + align:start position:0% +right what did I do + + + align:start position:0% +right what did I do +wrong oh okay I + + align:start position:0% +wrong oh okay I + + + align:start position:0% +wrong oh okay I +thought let's see I can't see it from + + align:start position:0% +thought let's see I can't see it from + + + align:start position:0% +thought let's see I can't see it from +here so + + align:start position:0% + + + + align:start position:0% + +I've F1 + + align:start position:0% + + + + align:start position:0% + +yeah they will backwards thank you + + align:start position:0% + + + + align:start position:0% + +okay so what do I do + + align:start position:0% + + + + align:start position:0% + +now + + align:start position:0% +now + + + align:start position:0% +now +H chain + + align:start position:0% +H chain + + + align:start position:0% +H chain +rule right so I just take the derivative + + align:start position:0% +rule right so I just take the derivative + + + align:start position:0% +rule right so I just take the derivative +that's and this is what it'll come out + + align:start position:0% +that's and this is what it'll come out + + + align:start position:0% +that's and this is what it'll come out +to be it'll + + align:start position:0% +to be it'll + + + align:start position:0% +to be it'll +be + + align:start position:0% +be + + + align:start position:0% +be +um is L constant + + align:start position:0% + + + + align:start position:0% + +is the Theta + + align:start position:0% +is the Theta + + + align:start position:0% +is the Theta +constant is the E1 constant in + + align:start position:0% +constant is the E1 constant in + + + align:start position:0% +constant is the E1 constant in +E + + align:start position:0% +E + + + align:start position:0% +E +yeah that's going to be in parts + + align:start position:0% + + + + align:start position:0% + +H actually I'll let you guys do it once + + align:start position:0% +H actually I'll let you guys do it once + + + align:start position:0% +H actually I'll let you guys do it once +you do it and read it out to + + align:start position:0% + + + + align:start position:0% + +me do it in Parts like I was trying to + + align:start position:0% +me do it in Parts like I was trying to + + + align:start position:0% +me do it in Parts like I was trying to +do it there I don't want to just write + + align:start position:0% +do it there I don't want to just write + + + align:start position:0% +do it there I don't want to just write +it out and you know I want you to read + + align:start position:0% +it out and you know I want you to read + + + align:start position:0% +it out and you know I want you to read +it out to + + align:start position:0% + + + + align:start position:0% + +me take this + + align:start position:0% +me take this + + + align:start position:0% +me take this +term Right Use the chain Rule and tell + + align:start position:0% +term Right Use the chain Rule and tell + + + align:start position:0% +term Right Use the chain Rule and tell +me what it's going to come out to be yes + + align:start position:0% +me what it's going to come out to be yes + + + align:start position:0% +me what it's going to come out to be yes +um E1 what's your name Amanda Amanda + + align:start position:0% +um E1 what's your name Amanda Amanda + + + align:start position:0% +um E1 what's your name Amanda Amanda +yeah yeah E1 uh in + + align:start position:0% +yeah yeah E1 uh in + + + align:start position:0% +yeah yeah E1 uh in +parentheses times uh L do cosine Theta + + align:start position:0% +parentheses times uh L do cosine Theta + + + align:start position:0% +parentheses times uh L do cosine Theta +minus L sin + + align:start position:0% + + + + align:start position:0% + +Theta and then nothing + + align:start position:0% + + + + align:start position:0% + +else L sin + + align:start position:0% + + + + align:start position:0% + +Theta that's it yeah is there a theod + + align:start position:0% +Theta that's it yeah is there a theod + + + align:start position:0% +Theta that's it yeah is there a theod +DOT yes yes + + align:start position:0% +DOT yes yes + + + align:start position:0% +DOT yes yes +very good and then um plus + + align:start position:0% +very good and then um plus + + + align:start position:0% +very good and then um plus +E2 L + + align:start position:0% + + + + align:start position:0% + +DOA + + align:start position:0% + + + + align:start position:0% + +L make + + align:start position:0% +L make + + + align:start position:0% +L make +sense + + align:start position:0% +sense + + + align:start position:0% +sense +right so here's the trick you know when + + align:start position:0% +right so here's the trick you know when + + + align:start position:0% +right so here's the trick you know when +I write vectors like in this way it's + + align:start position:0% +I write vectors like in this way it's + + + align:start position:0% +I write vectors like in this way it's +perfectly reasonable to do this E1 E2 + + align:start position:0% +perfectly reasonable to do this E1 E2 + + + align:start position:0% +perfectly reasonable to do this E1 E2 +and then I put an F1 here right and I + + align:start position:0% +and then I put an F1 here right and I + + + align:start position:0% +and then I put an F1 here right and I +said should make you feel queasy it + + align:start position:0% +said should make you feel queasy it + + + align:start position:0% +said should make you feel queasy it +shouldn't really that's okay it's okay + + align:start position:0% +shouldn't really that's okay it's okay + + + align:start position:0% +shouldn't really that's okay it's okay +but when you take the derivative of this + + align:start position:0% +but when you take the derivative of this + + + align:start position:0% +but when you take the derivative of this +guy with respect to a frame like e the + + align:start position:0% +guy with respect to a frame like e the + + + align:start position:0% +guy with respect to a frame like e the +first and cleanest way to do it is to + + align:start position:0% +first and cleanest way to do it is to + + + align:start position:0% +first and cleanest way to do it is to +downconvert all the uh kind of + + align:start position:0% +downconvert all the uh kind of + + + align:start position:0% +downconvert all the uh kind of +contaminating terms which are not E1 E2 + + align:start position:0% +contaminating terms which are not E1 E2 + + + align:start position:0% +contaminating terms which are not E1 E2 +bases down to E1 E2 bases get it and + + align:start position:0% +bases down to E1 E2 bases get it and + + + align:start position:0% +bases down to E1 E2 bases get it and +then take the derivative because even in + + align:start position:0% +then take the derivative because even in + + + align:start position:0% +then take the derivative because even in +E2 bases the basis vectors are constant + + align:start position:0% +E2 bases the basis vectors are constant + + + align:start position:0% +E2 bases the basis vectors are constant +in E if you just do this you know if you + + align:start position:0% +in E if you just do this you know if you + + + align:start position:0% +in E if you just do this you know if you +take the derivative of F1 by itself then + + align:start position:0% +take the derivative of F1 by itself then + + + align:start position:0% +take the derivative of F1 by itself then +You' figure out what it is and you'll + + align:start position:0% +You' figure out what it is and you'll + + + align:start position:0% +You' figure out what it is and you'll +end up converting anyway get it so the + + align:start position:0% +end up converting anyway get it so the + + + align:start position:0% +end up converting anyway get it so the +bottom line is that we've just + + align:start position:0% +bottom line is that we've just + + + align:start position:0% +bottom line is that we've just +computed that R PS is this so the + + align:start position:0% +computed that R PS is this so the + + + align:start position:0% +computed that R PS is this so the +velocity of the spider when you put it + + align:start position:0% +velocity of the spider when you put it + + + align:start position:0% +velocity of the spider when you put it +all together with respect to the + + align:start position:0% +all together with respect to the + + + align:start position:0% +all together with respect to the +Earth right which we write + + align:start position:0% +Earth right which we write + + + align:start position:0% +Earth right which we write +as e spider with respect to the Earth is + + align:start position:0% +as e spider with respect to the Earth is + + + align:start position:0% +as e spider with respect to the Earth is +equal to now add it all up and tell me + + align:start position:0% +equal to now add it all up and tell me + + + align:start position:0% +equal to now add it all up and tell me +please + + align:start position:0% + + + + align:start position:0% + +what yeah that's d by + + align:start position:0% + + + + align:start position:0% + +DT right okay what is + + align:start position:0% + + + + align:start position:0% + +this what is the velocity of the spider + + align:start position:0% +this what is the velocity of the spider + + + align:start position:0% +this what is the velocity of the spider +with respect to the frame e the Earth + + align:start position:0% + + + + align:start position:0% + +and that my friends is the velocity of + + align:start position:0% +and that my friends is the velocity of + + + align:start position:0% +and that my friends is the velocity of +the + + align:start position:0% +the + + + align:start position:0% +the +spider with respect to the Earth + + align:start position:0% + + + + align:start position:0% + +okay and that's the cleanest way to do + + align:start position:0% +okay and that's the cleanest way to do + + + align:start position:0% +okay and that's the cleanest way to do +it and we use no magic right we use + + align:start position:0% +it and we use no magic right we use + + + align:start position:0% +it and we use no magic right we use +frames and a very basic geometric + + align:start position:0% +frames and a very basic geometric + + + align:start position:0% +frames and a very basic geometric +transformation between frames and we + + align:start position:0% +transformation between frames and we + + + align:start position:0% +transformation between frames and we +calculate the + + align:start position:0% +calculate the + + + align:start position:0% +calculate the +velocity that's it there's no magic to + + align:start position:0% +velocity that's it there's no magic to + + + align:start position:0% +velocity that's it there's no magic to +it it's painful and when we get an + + align:start position:0% +it it's painful and when we get an + + + align:start position:0% +it it's painful and when we get an +acceleration it's going to get even more + + align:start position:0% +acceleration it's going to get even more + + + align:start position:0% +acceleration it's going to get even more +painful trust me we're going to + + align:start position:0% +painful trust me we're going to + + + align:start position:0% +painful trust me we're going to +calculate the acceleration now right but + + align:start position:0% +calculate the acceleration now right but + + + align:start position:0% +calculate the acceleration now right but +that's what it + + align:start position:0% +that's what it + + + align:start position:0% +that's what it +is + + align:start position:0% +is + + + align:start position:0% +is +so any questions about this and if if + + align:start position:0% +so any questions about this and if if + + + align:start position:0% +so any questions about this and if if +not we'll set up the next Point any + + align:start position:0% +not we'll set up the next Point any + + + align:start position:0% +not we'll set up the next Point any +questions I insist on at least one + + align:start position:0% +questions I insist on at least one + + + align:start position:0% +questions I insist on at least one +question at this point I'm out of + + align:start position:0% + + + + align:start position:0% + +breath anybody totally get it okay then + + align:start position:0% +breath anybody totally get it okay then + + + align:start position:0% +breath anybody totally get it okay then +I have a question for you how do you + + align:start position:0% +I have a question for you how do you + + + align:start position:0% +I have a question for you how do you +calculate the acceleration of the Spider + + align:start position:0% +calculate the acceleration of the Spider + + + align:start position:0% +calculate the acceleration of the Spider +by the way actually let's take a minute + + align:start position:0% +by the way actually let's take a minute + + + align:start position:0% +by the way actually let's take a minute +here and just appre appreciate what + + align:start position:0% +here and just appre appreciate what + + + align:start position:0% +here and just appre appreciate what +we've done + + align:start position:0% +we've done + + + align:start position:0% +we've done +here if this if the uh frisbee were not + + align:start position:0% +here if this if the uh frisbee were not + + + align:start position:0% +here if this if the uh frisbee were not +translating okay which terms would + + align:start position:0% +translating okay which terms would + + + align:start position:0% +translating okay which terms would +vanish so let's say I was spinning the + + align:start position:0% +vanish so let's say I was spinning the + + + align:start position:0% +vanish so let's say I was spinning the +frisbeer on my finger + + align:start position:0% +frisbeer on my finger + + + align:start position:0% +frisbeer on my finger +right this would go to + + align:start position:0% +right this would go to + + + align:start position:0% +right this would go to +zero and this would go to + + align:start position:0% + + + + align:start position:0% + +zero okay and you know what this turn + + align:start position:0% +zero okay and you know what this turn + + + align:start position:0% +zero okay and you know what this turn +the rest of it will turn + + align:start position:0% +the rest of it will turn + + + align:start position:0% +the rest of it will turn +into it'll be + + align:start position:0% +into it'll be + + + align:start position:0% +into it'll be +it'll be some sort of theta. L term + + align:start position:0% +it'll be some sort of theta. L term + + + align:start position:0% +it'll be some sort of theta. L term +theta. L does it make sense theta. L + + align:start position:0% +theta. L does it make sense theta. L + + + align:start position:0% +theta. L does it make sense theta. L +right this is the vector equivalent of + + align:start position:0% +right this is the vector equivalent of + + + align:start position:0% +right this is the vector equivalent of +theta. L get + + align:start position:0% +theta. L get + + + align:start position:0% +theta. L get +it right it's actually Omega cross R + + align:start position:0% +it right it's actually Omega cross R + + + align:start position:0% +it right it's actually Omega cross R +that's where it'll come down to be Omega + + align:start position:0% +that's where it'll come down to be Omega + + + align:start position:0% +that's where it'll come down to be Omega +cross the L Vector right we haven't done + + align:start position:0% +cross the L Vector right we haven't done + + + align:start position:0% +cross the L Vector right we haven't done +any cross products here by the way but + + align:start position:0% +any cross products here by the way but + + + align:start position:0% +any cross products here by the way but +you can see how it came out right does + + align:start position:0% +you can see how it came out right does + + + align:start position:0% +you can see how it came out right does +anyone understand what I just said to + + align:start position:0% +anyone understand what I just said to + + + align:start position:0% +anyone understand what I just said to +you right okay what if the if the SP if + + align:start position:0% +you right okay what if the if the SP if + + + align:start position:0% +you right okay what if the if the SP if +the spider were the center the Frisbee + + align:start position:0% +the spider were the center the Frisbee + + + align:start position:0% +the spider were the center the Frisbee +and not running + + align:start position:0% +and not running + + + align:start position:0% +and not running +away which terms would + + align:start position:0% +away which terms would + + + align:start position:0% +away which terms would +vanish l dot would go away what + + align:start position:0% +vanish l dot would go away what + + + align:start position:0% +vanish l dot would go away what +else and L would go + + align:start position:0% +else and L would go + + + align:start position:0% +else and L would go +zero right so what would the velocity be + + align:start position:0% +zero right so what would the velocity be + + + align:start position:0% +zero right so what would the velocity be +simply simply translation makes sense + + align:start position:0% +simply simply translation makes sense + + + align:start position:0% +simply simply translation makes sense +right right so this is a composition + + align:start position:0% +right right so this is a composition + + + align:start position:0% +right right so this is a composition +it's an addition of the translation + + align:start position:0% +it's an addition of the translation + + + align:start position:0% +it's an addition of the translation +velocity and the kind of the rotational + + align:start position:0% +velocity and the kind of the rotational + + + align:start position:0% +velocity and the kind of the rotational +aspect right so you know from basic + + align:start position:0% +aspect right so you know from basic + + + align:start position:0% +aspect right so you know from basic +physics you kind of see makes sense + + align:start position:0% +physics you kind of see makes sense + + + align:start position:0% +physics you kind of see makes sense +right yes okay now what we're going to + + align:start position:0% +right yes okay now what we're going to + + + align:start position:0% +right yes okay now what we're going to +do is calculate the + + align:start position:0% +do is calculate the + + + align:start position:0% +do is calculate the +acceleration and now we get into No + + align:start position:0% +acceleration and now we get into No + + + align:start position:0% +acceleration and now we get into No +Nonsense you know Vector derivatives + + align:start position:0% +Nonsense you know Vector derivatives + + + align:start position:0% +Nonsense you know Vector derivatives +here but there's no magic either it's + + align:start position:0% +here but there's no magic either it's + + + align:start position:0% +here but there's no magic either it's +just painstaking stuff we'll introduce + + align:start position:0% +just painstaking stuff we'll introduce + + + align:start position:0% +just painstaking stuff we'll introduce +the subtle stuff in a minute actually in + + align:start position:0% +the subtle stuff in a minute actually in + + + align:start position:0% +the subtle stuff in a minute actually in +the next class so how do you calculate + + align:start position:0% +the next class so how do you calculate + + + align:start position:0% +the next class so how do you calculate +the + + align:start position:0% + + + + align:start position:0% + +acceleration yep that's + + align:start position:0% +acceleration yep that's + + + align:start position:0% +acceleration yep that's +it no magic to it just take the + + align:start position:0% +it no magic to it just take the + + + align:start position:0% +it no magic to it just take the +derivative of the whole thing so let's + + align:start position:0% +derivative of the whole thing so let's + + + align:start position:0% +derivative of the whole thing so let's +do that because you know we right we + + align:start position:0% +do that because you know we right we + + + align:start position:0% +do that because you know we right we +don't do kind of stuff we do it all + + align:start position:0% +don't do kind of stuff we do it all + + + align:start position:0% +don't do kind of stuff we do it all +right let's do + + align:start position:0% + + + + align:start position:0% + +it so let's see e acceleration a of + + align:start position:0% +it so let's see e acceleration a of + + + align:start position:0% +it so let's see e acceleration a of +spider s is equal to D by DT I'm sorry + + align:start position:0% +spider s is equal to D by DT I'm sorry + + + align:start position:0% +spider s is equal to D by DT I'm sorry +I'm writing it small here of e velocity + + align:start position:0% +I'm writing it small here of e velocity + + + align:start position:0% +I'm writing it small here of e velocity +s is equal + + align:start position:0% + + + + align:start position:0% + +to okay let's start at this term what + + align:start position:0% +to okay let's start at this term what + + + align:start position:0% +to okay let's start at this term what +does this term + + align:start position:0% +does this term + + + align:start position:0% +does this term +become so let's put an E1 here because + + align:start position:0% +become so let's put an E1 here because + + + align:start position:0% +become so let's put an E1 here because +E1 is constant u double dot yeah keep + + align:start position:0% + + + + align:start position:0% + +going keep going + + align:start position:0% + + + + align:start position:0% + +keep going come + + align:start position:0% + + + + align:start position:0% + +on + + align:start position:0% + + + + align:start position:0% + +huh did we miss a + + align:start position:0% +huh did we miss a + + + align:start position:0% +huh did we miss a +term is that + + align:start position:0% + + + + align:start position:0% + +correct hold on that that should give us + + align:start position:0% +correct hold on that that should give us + + + align:start position:0% +correct hold on that that should give us +three terms right so it should give us + + align:start position:0% +three terms right so it should give us + + + align:start position:0% +three terms right so it should give us +the lble do term right the l dot + + align:start position:0% +the lble do term right the l dot + + + align:start position:0% +the lble do term right the l dot +um oh are we coming to this one now two + + align:start position:0% +um oh are we coming to this one now two + + + align:start position:0% +um oh are we coming to this one now two +terms I'm sorry okay yeah so go ahead + + align:start position:0% +terms I'm sorry okay yeah so go ahead + + + align:start position:0% +terms I'm sorry okay yeah so go ahead +sorry but I interrupted you go ahead + + align:start position:0% +sorry but I interrupted you go ahead + + + align:start position:0% +sorry but I interrupted you go ahead +yeah someone was reading out the next + + align:start position:0% +yeah someone was reading out the next + + + align:start position:0% +yeah someone was reading out the next +term to me go + + align:start position:0% + + + + align:start position:0% + +ahead + + align:start position:0% + + + + align:start position:0% + +uh-huh see I don't have my notes in + + align:start position:0% +uh-huh see I don't have my notes in + + + align:start position:0% +uh-huh see I don't have my notes in +front of me I'm right next to the board + + align:start position:0% +front of me I'm right next to the board + + + align:start position:0% +front of me I'm right next to the board +so you need to help me out here + + align:start position:0% + + + + align:start position:0% + +yeah okay is everyone in agreement with + + align:start position:0% +yeah okay is everyone in agreement with + + + align:start position:0% +yeah okay is everyone in agreement with +with + + align:start position:0% +with + + + align:start position:0% +with +this + + align:start position:0% +this + + + align:start position:0% +this +huh + + align:start position:0% +huh + + + align:start position:0% +huh +okay everyone agreement with this you + + align:start position:0% +okay everyone agreement with this you + + + align:start position:0% +okay everyone agreement with this you +did it I didn't do it okay that's the + + align:start position:0% +did it I didn't do it okay that's the + + + align:start position:0% +did it I didn't do it okay that's the +first term + + align:start position:0% +first term + + + align:start position:0% +first term +right plus + + align:start position:0% + + + + align:start position:0% + +E2 + + align:start position:0% +E2 + + + align:start position:0% +E2 +anybody someone else someone back + + align:start position:0% +anybody someone else someone back + + + align:start position:0% +anybody someone else someone back +there + + align:start position:0% + + + + align:start position:0% + +just then + + align:start position:0% + + + + align:start position:0% + +l + + align:start position:0% +l + + + align:start position:0% +l +dot sin Theta okay try and keep it in + + align:start position:0% +dot sin Theta okay try and keep it in + + + align:start position:0% +dot sin Theta okay try and keep it in +the same pattern okay because I'm trying + + align:start position:0% +the same pattern okay because I'm trying + + + align:start position:0% +the same pattern okay because I'm trying +to pull out a pattern for you here yep + + align:start position:0% +to pull out a pattern for you here yep + + + align:start position:0% +to pull out a pattern for you here yep +keep + + align:start position:0% + + + + align:start position:0% + +going + + align:start position:0% + + + + align:start position:0% + +plus + + align:start position:0% +plus + + + align:start position:0% +plus +uh-huh and then plus or minus next minus + + align:start position:0% +uh-huh and then plus or minus next minus + + + align:start position:0% +uh-huh and then plus or minus next minus +the double dot + + align:start position:0% + + + + align:start position:0% + +plus okay Theta double + + align:start position:0% + + + + align:start position:0% + +dot okay two more terms nearly + + align:start position:0% + + + + align:start position:0% + +there plus Theta do L do cosine + + align:start position:0% + + + + align:start position:0% + +Theta no magic was just pure hard work + + align:start position:0% +Theta no magic was just pure hard work + + + align:start position:0% +Theta no magic was just pure hard work +just took the derivative of that and we + + align:start position:0% +just took the derivative of that and we + + + align:start position:0% +just took the derivative of that and we +calculated the acceleration of the + + align:start position:0% +calculated the acceleration of the + + + align:start position:0% +calculated the acceleration of the +spider okay and what you just did + + align:start position:0% +spider okay and what you just did + + + align:start position:0% +spider okay and what you just did +encapsulates 300 years of physics + + align:start position:0% +encapsulates 300 years of physics + + + align:start position:0% +encapsulates 300 years of physics +believe it or not and there are famous + + align:start position:0% +believe it or not and there are famous + + + align:start position:0% +believe it or not and there are famous +names attached to some of these terms + + align:start position:0% +names attached to some of these terms + + + align:start position:0% +names attached to some of these terms +and I'm going to give you those names + + align:start position:0% +and I'm going to give you those names + + + align:start position:0% +and I'm going to give you those names +now and I said it to the last class and + + align:start position:0% +now and I said it to the last class and + + + align:start position:0% +now and I said it to the last class and +I make the pr same promise to you guys + + align:start position:0% +I make the pr same promise to you guys + + + align:start position:0% +I make the pr same promise to you guys +if he came up with a term here that the + + align:start position:0% +if he came up with a term here that the + + + align:start position:0% +if he came up with a term here that the +other physicist have missed we'll I'll + + align:start position:0% +other physicist have missed we'll I'll + + + align:start position:0% +other physicist have missed we'll I'll +name it after the guy the person in the + + align:start position:0% +name it after the guy the person in the + + + align:start position:0% +name it after the guy the person in the +class who came up with this right so for + + align:start position:0% +class who came up with this right so for + + + align:start position:0% +class who came up with this right so for +example some of these terms are called + + align:start position:0% +example some of these terms are called + + + align:start position:0% +example some of these terms are called +cholis terms so we'll call it the Rachel + + align:start position:0% +cholis terms so we'll call it the Rachel + + + align:start position:0% +cholis terms so we'll call it the Rachel +term if you came up with that okay all + + align:start position:0% +term if you came up with that okay all + + + align:start position:0% +term if you came up with that okay all +right right so let's examine this so + + align:start position:0% +right right so let's examine this so + + + align:start position:0% +right right so let's examine this so +this is the vector form of it right what + + align:start position:0% +this is the vector form of it right what + + + align:start position:0% +this is the vector form of it right what +is this kind of in + + align:start position:0% + + + + align:start position:0% + +English translation acceleration right + + align:start position:0% + + + + align:start position:0% + +translation + + align:start position:0% +translation + + + align:start position:0% +translation +okay of the Frisbee center of the + + align:start position:0% +okay of the Frisbee center of the + + + align:start position:0% +okay of the Frisbee center of the +Frisbee right + + align:start position:0% + + + + align:start position:0% + +what is um + + align:start position:0% +what is um + + + align:start position:0% +what is um +this capture kind of in + + align:start position:0% + + + + align:start position:0% + +English + + align:start position:0% +English + + + align:start position:0% +English +of with respect + + align:start position:0% +of with respect + + + align:start position:0% +of with respect +to yeah yeah in English that's kind of + + align:start position:0% +to yeah yeah in English that's kind of + + + align:start position:0% +to yeah yeah in English that's kind of +what this is this is a spider kind of + + align:start position:0% +what this is this is a spider kind of + + + align:start position:0% +what this is this is a spider kind of +right there + + align:start position:0% + + + + align:start position:0% + +spider spider term okay these are kind + + align:start position:0% +spider spider term okay these are kind + + + align:start position:0% +spider spider term okay these are kind +of informal terms but I'll formalize + + align:start position:0% +of informal terms but I'll formalize + + + align:start position:0% +of informal terms but I'll formalize +them later + + align:start position:0% +them later + + + align:start position:0% +them later +on spider + + align:start position:0% + + + + align:start position:0% + +translation okay + + align:start position:0% + + + + align:start position:0% + +um anyone recognize this term + + align:start position:0% + + + + align:start position:0% + +yeah and that's called + + align:start position:0% +yeah and that's called + + + align:start position:0% +yeah and that's called +the centripetal acceleration get it + + align:start position:0% +the centripetal acceleration get it + + + align:start position:0% +the centripetal acceleration get it +remember Theta do squ make ring a bell + + align:start position:0% +remember Theta do squ make ring a bell + + + align:start position:0% +remember Theta do squ make ring a bell +Theta dot squ right spin something kind + + align:start position:0% +Theta dot squ right spin something kind + + + align:start position:0% +Theta dot squ right spin something kind +of accelerates inwards right L Theta do + + align:start position:0% +of accelerates inwards right L Theta do + + + align:start position:0% +of accelerates inwards right L Theta do +squ hey there's an L Theta do squ sin + + align:start position:0% +squ hey there's an L Theta do squ sin + + + align:start position:0% +squ hey there's an L Theta do squ sin +Theta cos cosine Theta so that's the + + align:start position:0% +Theta cos cosine Theta so that's the + + + align:start position:0% +Theta cos cosine Theta so that's the +vector form of it right right so that's + + align:start position:0% +vector form of it right right so that's + + + align:start position:0% +vector form of it right right so that's +centripedal right it's named after a + + align:start position:0% +centripedal right it's named after a + + + align:start position:0% +centripedal right it's named after a +famous French engineer but the name is + + align:start position:0% +famous French engineer but the name is + + + align:start position:0% +famous French engineer but the name is +centripedal I'm kidding centripedal + + align:start position:0% +centripedal I'm kidding centripedal + + + align:start position:0% +centripedal I'm kidding centripedal +right + + align:start position:0% + + + + align:start position:0% + +cental + + align:start position:0% + + + + align:start position:0% + +okay anyone does this term kind of make + + align:start position:0% +okay anyone does this term kind of make + + + align:start position:0% +okay anyone does this term kind of make +sense what's + + align:start position:0% + + + + align:start position:0% + +that yeah is the angular acceleration + + align:start position:0% +that yeah is the angular acceleration + + + align:start position:0% +that yeah is the angular acceleration +multipied by the force arm right but + + align:start position:0% +multipied by the force arm right but + + + align:start position:0% +multipied by the force arm right but +again written in vector vector form + + align:start position:0% +again written in vector vector form + + + align:start position:0% +again written in vector vector form +right does that make + + align:start position:0% +right does that make + + + align:start position:0% +right does that make +sense and that is actually for some + + align:start position:0% +sense and that is actually for some + + + align:start position:0% +sense and that is actually for some +reason coil the oiler + + align:start position:0% + + + + align:start position:0% + +acceleration and then we have two guys + + align:start position:0% +acceleration and then we have two guys + + + align:start position:0% +acceleration and then we have two guys +left + + align:start position:0% +left + + + align:start position:0% +left +out anyone remember what those are + + align:start position:0% +out anyone remember what those are + + + align:start position:0% +out anyone remember what those are +called + + align:start position:0% +called + + + align:start position:0% +called +yep cholis here's the deal they're just + + align:start position:0% +yep cholis here's the deal they're just + + + align:start position:0% +yep cholis here's the deal they're just +two straight terms if you do the math + + align:start position:0% +two straight terms if you do the math + + + align:start position:0% +two straight terms if you do the math +right they show up we did the math right + + align:start position:0% +right they show up we did the math right + + + align:start position:0% +right they show up we did the math right +they showed up no + + align:start position:0% +they showed up no + + + align:start position:0% +they showed up no +surprise right now actually the funny + + align:start position:0% +surprise right now actually the funny + + + align:start position:0% +surprise right now actually the funny +thing is you see it's minus L do theta + + align:start position:0% +thing is you see it's minus L do theta + + + align:start position:0% +thing is you see it's minus L do theta +dot it's the same term twice right so I + + align:start position:0% +dot it's the same term twice right so I + + + align:start position:0% +dot it's the same term twice right so I +can actually make this + + align:start position:0% +can actually make this + + + align:start position:0% +can actually make this +two right and remove this and the same + + align:start position:0% +two right and remove this and the same + + + align:start position:0% +two right and remove this and the same +term twice here I can put a two here and + + align:start position:0% +term twice here I can put a two here and + + + align:start position:0% +term twice here I can put a two here and +remove this the same thing I just + + align:start position:0% +remove this the same thing I just + + + align:start position:0% +remove this the same thing I just +consolidating terms and there was this + + align:start position:0% +consolidating terms and there was this + + + align:start position:0% +consolidating terms and there was this +French engineer by the name of + + align:start position:0% +French engineer by the name of + + + align:start position:0% +French engineer by the name of +coris he found I think the history is + + align:start position:0% +coris he found I think the history is + + + align:start position:0% +coris he found I think the history is +that um + + align:start position:0% +that um + + + align:start position:0% +that um +when you shoot a projectile from a ship + + align:start position:0% +when you shoot a projectile from a ship + + + align:start position:0% +when you shoot a projectile from a ship +or from any vehicle but usually ships in + + align:start position:0% +or from any vehicle but usually ships in + + + align:start position:0% +or from any vehicle but usually ships in +the northern hemisphere they I think + + align:start position:0% +the northern hemisphere they I think + + + align:start position:0% +the northern hemisphere they I think +Gunners found that they were missing to + + align:start position:0% +Gunners found that they were missing to + + + align:start position:0% +Gunners found that they were missing to +one side and there to kind of compensate + + align:start position:0% +one side and there to kind of compensate + + + align:start position:0% +one side and there to kind of compensate +and once the Gunners perfected the skill + + align:start position:0% +and once the Gunners perfected the skill + + + align:start position:0% +and once the Gunners perfected the skill +and they cross the Equator they found + + align:start position:0% +and they cross the Equator they found + + + align:start position:0% +and they cross the Equator they found +that their skill was useless because + + align:start position:0% +that their skill was useless because + + + align:start position:0% +that their skill was useless because +they would go to the other side and the + + align:start position:0% +they would go to the other side and the + + + align:start position:0% +they would go to the other side and the +straight term is referred to as the + + align:start position:0% +straight term is referred to as the + + + align:start position:0% +straight term is referred to as the +coris + + align:start position:0% +coris + + + align:start position:0% +coris +acceleration okay this is also the + + align:start position:0% +acceleration okay this is also the + + + align:start position:0% +acceleration okay this is also the +reason hurricanes spin one way in the + + align:start position:0% +reason hurricanes spin one way in the + + + align:start position:0% +reason hurricanes spin one way in the +northern Hemisphere and another way in + + align:start position:0% +northern Hemisphere and another way in + + + align:start position:0% +northern Hemisphere and another way in +the southern hemisphere we'll talk about + + align:start position:0% +the southern hemisphere we'll talk about + + + align:start position:0% +the southern hemisphere we'll talk about +all this the beginning of the next class + + align:start position:0% +all this the beginning of the next class + + + align:start position:0% +all this the beginning of the next class +but what you've just done with + + align:start position:0% +but what you've just done with + + + align:start position:0% +but what you've just done with +me is from Ground Zero using the most + + align:start position:0% +me is from Ground Zero using the most + + + align:start position:0% +me is from Ground Zero using the most +basic basic geometry you have derived + + align:start position:0% +basic basic geometry you have derived + + + align:start position:0% +basic basic geometry you have derived +terms that go back 300 years or took 300 + + align:start position:0% +terms that go back 300 years or took 300 + + + align:start position:0% +terms that go back 300 years or took 300 +years to derive so this + + align:start position:0% +years to derive so this + + + align:start position:0% +years to derive so this +term this collection of terms is called + + align:start position:0% +term this collection of terms is called + + + align:start position:0% +term this collection of terms is called +coris and this is the most general + + align:start position:0% +coris and this is the most general + + + align:start position:0% +coris and this is the most general +statement of the calculation of + + align:start position:0% +statement of the calculation of + + + align:start position:0% +statement of the calculation of +acceleration that you will need in + + align:start position:0% +acceleration that you will need in + + + align:start position:0% +acceleration that you will need in +kinematics to + + align:start position:0% +kinematics to + + + align:start position:0% +kinematics to +compute the motion of complex systems + + align:start position:0% +compute the motion of complex systems + + + align:start position:0% +compute the motion of complex systems +and now if you have now look we can we + + align:start position:0% +and now if you have now look we can we + + + align:start position:0% +and now if you have now look we can we +can do frame e to F right let's say + + align:start position:0% +can do frame e to F right let's say + + + align:start position:0% +can do frame e to F right let's say +those let's say the Earth spinning and + + align:start position:0% +those let's say the Earth spinning and + + + align:start position:0% +those let's say the Earth spinning and +there's someone watching us from other + + align:start position:0% +there's someone watching us from other + + + align:start position:0% +there's someone watching us from other +another planet well no problem you can + + align:start position:0% +another planet well no problem you can + + + align:start position:0% +another planet well no problem you can +kind of compose it and you can you know + + align:start position:0% +kind of compose it and you can you know + + + align:start position:0% +kind of compose it and you can you know +compute the acceleration with respect to + + align:start position:0% +compute the acceleration with respect to + + + align:start position:0% +compute the acceleration with respect to +that planet the math will get hairy but + + align:start position:0% +that planet the math will get hairy but + + + align:start position:0% +that planet the math will get hairy but +there's nothing profound get it + + align:start position:0% +there's nothing profound get it + + + align:start position:0% +there's nothing profound get it +questions all right we'll see you next + + align:start position:0% +questions all right we'll see you next + + + align:start position:0% +questions all right we'll see you next +class \ No newline at end of file diff --git a/vyShGGc2X38.txt b/vyShGGc2X38.txt new file mode 100644 index 0000000000000000000000000000000000000000..7449f5658b6a719c894554a7b650af347429a128 --- /dev/null +++ b/vyShGGc2X38.txt @@ -0,0 +1,203 @@ +align:start position:0% + +hi everybody our first thing that we + + align:start position:0% +hi everybody our first thing that we + + + align:start position:0% +hi everybody our first thing that we +really want to think about is how are we + + align:start position:0% +really want to think about is how are we + + + align:start position:0% +really want to think about is how are we +going to + + align:start position:0% +going to + + + align:start position:0% +going to +represent + + align:start position:0% +represent + + + align:start position:0% +represent +musical objects + + align:start position:0% +musical objects + + + align:start position:0% +musical objects +music on a computer so let's start with + + align:start position:0% +music on a computer so let's start with + + + align:start position:0% +music on a computer so let's start with +maybe one of the most fundamental things + + align:start position:0% +maybe one of the most fundamental things + + + align:start position:0% +maybe one of the most fundamental things +and that is pitch so + + align:start position:0% +and that is pitch so + + + align:start position:0% +and that is pitch so +in a score-based class we might + + align:start position:0% +in a score-based class we might + + + align:start position:0% +in a score-based class we might +represent pitch with a score and we + + align:start position:0% +represent pitch with a score and we + + + align:start position:0% +represent pitch with a score and we +write notes on + + align:start position:0% +write notes on + + + align:start position:0% +write notes on +it I guess then we assign it to a + + align:start position:0% +it I guess then we assign it to a + + + align:start position:0% +it I guess then we assign it to a +variable well that's not going to work + + align:start position:0% +variable well that's not going to work + + + align:start position:0% +variable well that's not going to work +um okay so we we take a a frequency and + + align:start position:0% +um okay so we we take a a frequency and + + + align:start position:0% +um okay so we we take a a frequency and +we assign that to a variable well I'm + + align:start position:0% +we assign that to a variable well I'm + + + align:start position:0% +we assign that to a variable well I'm +not exactly sure how to do that either + + align:start position:0% +not exactly sure how to do that either + + + align:start position:0% +not exactly sure how to do that either +um maybe we just assign a variable to a + + align:start position:0% +um maybe we just assign a variable to a + + + align:start position:0% +um maybe we just assign a variable to a +particular number representing a + + align:start position:0% +particular number representing a + + + align:start position:0% +particular number representing a +frequency or to a + + align:start position:0% +frequency or to a + + + align:start position:0% +frequency or to a +string representing a + + align:start position:0% +string representing a + + + align:start position:0% +string representing a +pitch + + align:start position:0% +pitch + + + align:start position:0% +pitch +okay first thing I want you to do is + + align:start position:0% +okay first thing I want you to do is + + + align:start position:0% +okay first thing I want you to do is +take five minutes no more than that and + + align:start position:0% +take five minutes no more than that and + + + align:start position:0% +take five minutes no more than that and +jot down some notes on how you like + + align:start position:0% +jot down some notes on how you like + + + align:start position:0% +jot down some notes on how you like +represent pitch on a computer very + + align:start position:0% +represent pitch on a computer very + + + align:start position:0% +represent pitch on a computer very +naively \ No newline at end of file diff --git a/wDLzLN1tArA.txt b/wDLzLN1tArA.txt new file mode 100644 index 0000000000000000000000000000000000000000..d22818e0b2a837a2075e086282ea30d54e60c0da --- /dev/null +++ b/wDLzLN1tArA.txt @@ -0,0 +1,11835 @@ +align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +topic for the classes interpretability + + align:start position:0% +topic for the classes interpretability + + + align:start position:0% +topic for the classes interpretability +as you know the modern machine learning + + align:start position:0% +as you know the modern machine learning + + + align:start position:0% +as you know the modern machine learning +models are justifiably reputed to be + + align:start position:0% +models are justifiably reputed to be + + + align:start position:0% +models are justifiably reputed to be +very difficult to understand so if I + + align:start position:0% +very difficult to understand so if I + + + align:start position:0% +very difficult to understand so if I +give you something like the GPT 2 model + + align:start position:0% +give you something like the GPT 2 model + + + align:start position:0% +give you something like the GPT 2 model +which we talked about a natural language + + align:start position:0% +which we talked about a natural language + + + align:start position:0% +which we talked about a natural language +processing and I tell you that it has + + align:start position:0% +processing and I tell you that it has + + + align:start position:0% +processing and I tell you that it has +1.5 billion parameters and then you say + + align:start position:0% +1.5 billion parameters and then you say + + + align:start position:0% +1.5 billion parameters and then you say +mm why is it working + + align:start position:0% +mm why is it working + + + align:start position:0% +mm why is it working +clearly the answer is not because these + + align:start position:0% +clearly the answer is not because these + + + align:start position:0% +clearly the answer is not because these +particular parameters have these + + align:start position:0% +particular parameters have these + + + align:start position:0% +particular parameters have these +particular values + + align:start position:0% +particular values + + + align:start position:0% +particular values +there's no way to understand that and so + + align:start position:0% +there's no way to understand that and so + + + align:start position:0% +there's no way to understand that and so +the topic today is something that we + + align:start position:0% +the topic today is something that we + + + align:start position:0% +the topic today is something that we +raised a little bit in the lecture on + + align:start position:0% +raised a little bit in the lecture on + + + align:start position:0% +raised a little bit in the lecture on +fairness where one of the issues there + + align:start position:0% +fairness where one of the issues there + + + align:start position:0% +fairness where one of the issues there +was also that if you can't understand + + align:start position:0% +was also that if you can't understand + + + align:start position:0% +was also that if you can't understand +the model you can't tell if the model + + align:start position:0% +the model you can't tell if the model + + + align:start position:0% +the model you can't tell if the model +has baked in prejudices by examining it + + align:start position:0% +has baked in prejudices by examining it + + + align:start position:0% +has baked in prejudices by examining it +and so today we're going to look at + + align:start position:0% +and so today we're going to look at + + + align:start position:0% +and so today we're going to look at +different methods that people have + + align:start position:0% +different methods that people have + + + align:start position:0% +different methods that people have +developed to try to overcome this + + align:start position:0% +developed to try to overcome this + + + align:start position:0% +developed to try to overcome this +problem of inscrutable models so there's + + align:start position:0% +problem of inscrutable models so there's + + + align:start position:0% +problem of inscrutable models so there's +a very interesting bit of history how + + align:start position:0% +a very interesting bit of history how + + + align:start position:0% +a very interesting bit of history how +many of you know of george miller 7 plus + + align:start position:0% +many of you know of george miller 7 plus + + + align:start position:0% +many of you know of george miller 7 plus +or minus 2 result only a few so miller + + align:start position:0% +or minus 2 result only a few so miller + + + align:start position:0% +or minus 2 result only a few so miller +was a psychologist at at harvard I think + + align:start position:0% +was a psychologist at at harvard I think + + + align:start position:0% +was a psychologist at at harvard I think +in the 1950s and he wrote this paper in + + align:start position:0% +in the 1950s and he wrote this paper in + + + align:start position:0% +in the 1950s and he wrote this paper in +1956 called the magical number 7 plus or + + align:start position:0% +1956 called the magical number 7 plus or + + + align:start position:0% +1956 called the magical number 7 plus or +minus 2 some limits on our capacity for + + align:start position:0% +minus 2 some limits on our capacity for + + + align:start position:0% +minus 2 some limits on our capacity for +processing information it's quite an + + align:start position:0% +processing information it's quite an + + + align:start position:0% +processing information it's quite an +interesting paper so he started off with + + align:start position:0% +interesting paper so he started off with + + + align:start position:0% +interesting paper so he started off with +something that I had forgotten I read + + align:start position:0% +something that I had forgotten I read + + + align:start position:0% +something that I had forgotten I read +this paper many many years ago and I had + + align:start position:0% +this paper many many years ago and I had + + + align:start position:0% +this paper many many years ago and I had +forgotten that he starts off with the + + align:start position:0% +forgotten that he starts off with the + + + align:start position:0% +forgotten that he starts off with the +question of how many different things + + align:start position:0% +question of how many different things + + + align:start position:0% +question of how many different things +can you sense how many different levels + + align:start position:0% +can you sense how many different levels + + + align:start position:0% +can you sense how many different levels +of things can you sense so if I put + + align:start position:0% +of things can you sense so if I put + + + align:start position:0% +of things can you sense so if I put +headphones on you and I ask you to tell + + align:start position:0% +headphones on you and I ask you to tell + + + align:start position:0% +headphones on you and I ask you to tell +me on a scale of 1 to n how loud is the + + align:start position:0% +me on a scale of 1 to n how loud is the + + + align:start position:0% +me on a scale of 1 to n how loud is the +sound + + align:start position:0% +sound + + + align:start position:0% +sound +that I'm playing in your headphone it + + align:start position:0% +that I'm playing in your headphone it + + + align:start position:0% +that I'm playing in your headphone it +turns out people get confused when you + + align:start position:0% +turns out people get confused when you + + + align:start position:0% +turns out people get confused when you +get beyond about five six seven + + align:start position:0% +get beyond about five six seven + + + align:start position:0% +get beyond about five six seven +different levels of intensity and + + align:start position:0% +different levels of intensity and + + + align:start position:0% +different levels of intensity and +similarly if I give you a bunch of + + align:start position:0% +similarly if I give you a bunch of + + + align:start position:0% +similarly if I give you a bunch of +colors and I ask you to tell me where + + align:start position:0% +colors and I ask you to tell me where + + + align:start position:0% +colors and I ask you to tell me where +the boundaries are between different + + align:start position:0% +the boundaries are between different + + + align:start position:0% +the boundaries are between different +colors people seem to come up with seven + + align:start position:0% +colors people seem to come up with seven + + + align:start position:0% +colors people seem to come up with seven +plus or minus two as the number of + + align:start position:0% +plus or minus two as the number of + + + align:start position:0% +plus or minus two as the number of +colors that they can distinguish and so + + align:start position:0% +colors that they can distinguish and so + + + align:start position:0% +colors that they can distinguish and so +there's a long psychological literature + + align:start position:0% +there's a long psychological literature + + + align:start position:0% +there's a long psychological literature +of this and then Miller went on to do + + align:start position:0% +of this and then Miller went on to do + + + align:start position:0% +of this and then Miller went on to do +experiments where he asked people to + + align:start position:0% +experiments where he asked people to + + + align:start position:0% +experiments where he asked people to +memorize lists of things and what he + + align:start position:0% +memorize lists of things and what he + + + align:start position:0% +memorize lists of things and what he +discovered is again that you could + + align:start position:0% +discovered is again that you could + + + align:start position:0% +discovered is again that you could +memorize a list of about seven plus or + + align:start position:0% +memorize a list of about seven plus or + + + align:start position:0% +memorize a list of about seven plus or +minus two things and beyond that you + + align:start position:0% +minus two things and beyond that you + + + align:start position:0% +minus two things and beyond that you +couldn't remember the list anymore so + + align:start position:0% +couldn't remember the list anymore so + + + align:start position:0% +couldn't remember the list anymore so +this tells us something about the + + align:start position:0% +this tells us something about the + + + align:start position:0% +this tells us something about the +cognitive capacity of the human mind and + + align:start position:0% +cognitive capacity of the human mind and + + + align:start position:0% +cognitive capacity of the human mind and +it suggests that if I give you an + + align:start position:0% +it suggests that if I give you an + + + align:start position:0% +it suggests that if I give you an +explanation that has 20 things in it + + align:start position:0% +explanation that has 20 things in it + + + align:start position:0% +explanation that has 20 things in it +you're unlikely to be able to fathom it + + align:start position:0% +you're unlikely to be able to fathom it + + + align:start position:0% +you're unlikely to be able to fathom it +because you can't keep all the moving + + align:start position:0% +because you can't keep all the moving + + + align:start position:0% +because you can't keep all the moving +parts in your mind at one time now it's + + align:start position:0% +parts in your mind at one time now it's + + + align:start position:0% +parts in your mind at one time now it's +a tricky result because he does point + + align:start position:0% +a tricky result because he does point + + + align:start position:0% +a tricky result because he does point +out even in 1956 that if you chunk + + align:start position:0% +out even in 1956 that if you chunk + + + align:start position:0% +out even in 1956 that if you chunk +things into bigger chunks you can + + align:start position:0% +things into bigger chunks you can + + + align:start position:0% +things into bigger chunks you can +remember seven of those even if they're + + align:start position:0% +remember seven of those even if they're + + + align:start position:0% +remember seven of those even if they're +much bigger and so people who are very + + align:start position:0% +much bigger and so people who are very + + + align:start position:0% +much bigger and so people who are very +good at memorizing things for example + + align:start position:0% +good at memorizing things for example + + + align:start position:0% +good at memorizing things for example +make up patterns and they remember those + + align:start position:0% +make up patterns and they remember those + + + align:start position:0% +make up patterns and they remember those +patterns which then allow them to + + align:start position:0% +patterns which then allow them to + + + align:start position:0% +patterns which then allow them to +actually remember more primitive objects + + align:start position:0% +actually remember more primitive objects + + + align:start position:0% +actually remember more primitive objects +so it you know and we still don't really + + align:start position:0% +so it you know and we still don't really + + + align:start position:0% +so it you know and we still don't really +understand how memory works but this is + + align:start position:0% +understand how memory works but this is + + + align:start position:0% +understand how memory works but this is +just an interesting observation and I + + align:start position:0% +just an interesting observation and I + + + align:start position:0% +just an interesting observation and I +think plays into the question of of how + + align:start position:0% +think plays into the question of of how + + + align:start position:0% +think plays into the question of of how +do you explain things in a complicated + + align:start position:0% +do you explain things in a complicated + + + align:start position:0% +do you explain things in a complicated +model because it suggests that you can't + + align:start position:0% +model because it suggests that you can't + + + align:start position:0% +model because it suggests that you can't +explain too many different things + + align:start position:0% +explain too many different things + + + align:start position:0% +explain too many different things +because people won't understand what + + align:start position:0% +because people won't understand what + + + align:start position:0% +because people won't understand what +you're talking about okay so what leads + + align:start position:0% +you're talking about okay so what leads + + + align:start position:0% +you're talking about okay so what leads +to complex models well as I say + + align:start position:0% +to complex models well as I say + + + align:start position:0% +to complex models well as I say +overfitting certainly lead + + align:start position:0% +overfitting certainly lead + + + align:start position:0% +overfitting certainly lead +two complex models I remember in the + + align:start position:0% +two complex models I remember in the + + + align:start position:0% +two complex models I remember in the +1970s when we started working on expert + + align:start position:0% +1970s when we started working on expert + + + align:start position:0% +1970s when we started working on expert +systems and in healthcare I I made a + + align:start position:0% +systems and in healthcare I I made a + + + align:start position:0% +systems and in healthcare I I made a +very bad faux pas I went to the first + + align:start position:0% +very bad faux pas I went to the first + + + align:start position:0% +very bad faux pas I went to the first +joint conference between statisticians + + align:start position:0% +joint conference between statisticians + + + align:start position:0% +joint conference between statisticians +and artificial intelligence researchers + + align:start position:0% +and artificial intelligence researchers + + + align:start position:0% +and artificial intelligence researchers +and the statisticians were all about you + + align:start position:0% +and the statisticians were all about you + + + align:start position:0% +and the statisticians were all about you +know understanding the variance and + + align:start position:0% +know understanding the variance and + + + align:start position:0% +know understanding the variance and +understanding statistical significance + + align:start position:0% +understanding statistical significance + + + align:start position:0% +understanding statistical significance +and so on and I was all about trying to + + align:start position:0% +and so on and I was all about trying to + + + align:start position:0% +and so on and I was all about trying to +model details of what was going on in an + + align:start position:0% +model details of what was going on in an + + + align:start position:0% +model details of what was going on in an +individual patient and in some + + align:start position:0% +individual patient and in some + + + align:start position:0% +individual patient and in some +discussion after my talk somebody + + align:start position:0% +discussion after my talk somebody + + + align:start position:0% +discussion after my talk somebody +challenged me and I said well what we a + + align:start position:0% +challenged me and I said well what we a + + + align:start position:0% +challenged me and I said well what we a +I people are really doing is fitting + + align:start position:0% +I people are really doing is fitting + + + align:start position:0% +I people are really doing is fitting +what you guys think is the noise right + + align:start position:0% +what you guys think is the noise right + + + align:start position:0% +what you guys think is the noise right +because we're trying to make a lot more + + align:start position:0% +because we're trying to make a lot more + + + align:start position:0% +because we're trying to make a lot more +detailed refinements in our theories in + + align:start position:0% +detailed refinements in our theories in + + + align:start position:0% +detailed refinements in our theories in +our models than what the typical + + align:start position:0% +our models than what the typical + + + align:start position:0% +our models than what the typical +statistical model does and of course I + + align:start position:0% +statistical model does and of course I + + + align:start position:0% +statistical model does and of course I +was roundly booed out of out of the hall + + align:start position:0% +was roundly booed out of out of the hall + + + align:start position:0% +was roundly booed out of out of the hall +and people shunned me for the rest of + + align:start position:0% +and people shunned me for the rest of + + + align:start position:0% +and people shunned me for the rest of +the conference because I had done + + align:start position:0% +the conference because I had done + + + align:start position:0% +the conference because I had done +something really stupid + + align:start position:0% +something really stupid + + + align:start position:0% +something really stupid +to admit that I was I was fitting noise + + align:start position:0% +to admit that I was I was fitting noise + + + align:start position:0% +to admit that I was I was fitting noise +and of course I didn't really believe + + align:start position:0% +and of course I didn't really believe + + + align:start position:0% +and of course I didn't really believe +that I was fitting noise I was believed + + align:start position:0% +that I was fitting noise I was believed + + + align:start position:0% +that I was fitting noise I was believed +that what I was fitting was what the + + align:start position:0% +that what I was fitting was what the + + + align:start position:0% +that what I was fitting was what the +average statistician just chalks up to + + align:start position:0% +average statistician just chalks up to + + + align:start position:0% +average statistician just chalks up to +noise and we're interested in more + + align:start position:0% +noise and we're interested in more + + + align:start position:0% +noise and we're interested in more +details of the mechanisms so overfitting + + align:start position:0% +details of the mechanisms so overfitting + + + align:start position:0% +details of the mechanisms so overfitting +we have a pretty good handle on by + + align:start position:0% +we have a pretty good handle on by + + + align:start position:0% +we have a pretty good handle on by +regularization so you can you know + + align:start position:0% +regularization so you can you know + + + align:start position:0% +regularization so you can you know +you've seen lots of examples of + + align:start position:0% +you've seen lots of examples of + + + align:start position:0% +you've seen lots of examples of +regularization throughout the course and + + align:start position:0% +regularization throughout the course and + + + align:start position:0% +regularization throughout the course and +people keep coming up with interesting + + align:start position:0% +people keep coming up with interesting + + + align:start position:0% +people keep coming up with interesting +ideas for how to apply regularization in + + align:start position:0% +ideas for how to apply regularization in + + + align:start position:0% +ideas for how to apply regularization in +order to simplify models or make them + + align:start position:0% +order to simplify models or make them + + + align:start position:0% +order to simplify models or make them +fit some preconception of what the model + + align:start position:0% +fit some preconception of what the model + + + align:start position:0% +fit some preconception of what the model +ought to look like before you start + + align:start position:0% +ought to look like before you start + + + align:start position:0% +ought to look like before you start +learning it from data but the problem is + + align:start position:0% +learning it from data but the problem is + + + align:start position:0% +learning it from data but the problem is +that there's there really is true + + align:start position:0% +that there's there really is true + + + align:start position:0% +that there's there really is true +complexity to these models whether or + + align:start position:0% +complexity to these models whether or + + + align:start position:0% +complexity to these models whether or +not you're fitting noise there's the + + align:start position:0% +not you're fitting noise there's the + + + align:start position:0% +not you're fitting noise there's the +world is a complicated place + + align:start position:0% +world is a complicated place + + + align:start position:0% +world is a complicated place +human beings were not designed they + + align:start position:0% +human beings were not designed they + + + align:start position:0% +human beings were not designed they +evolved and so there's all kinds of + + align:start position:0% +evolved and so there's all kinds of + + + align:start position:0% +evolved and so there's all kinds of +bizarre stuff left over from our + + align:start position:0% +bizarre stuff left over from our + + + align:start position:0% +bizarre stuff left over from our +evolutionary heritage and so it is just + + align:start position:0% +evolutionary heritage and so it is just + + + align:start position:0% +evolutionary heritage and so it is just +complex it's hard to understand in a + + align:start position:0% +complex it's hard to understand in a + + + align:start position:0% +complex it's hard to understand in a +simple way how to make predictions that + + align:start position:0% +simple way how to make predictions that + + + align:start position:0% +simple way how to make predictions that +are useful when the world really is + + align:start position:0% +are useful when the world really is + + + align:start position:0% +are useful when the world really is +complex so what do we do in order to try + + align:start position:0% +complex so what do we do in order to try + + + align:start position:0% +complex so what do we do in order to try +to deal with this well one approach is + + align:start position:0% +to deal with this well one approach is + + + align:start position:0% +to deal with this well one approach is +to make up what I call just so stories + + align:start position:0% +to make up what I call just so stories + + + align:start position:0% +to make up what I call just so stories +that give a simplified explanation of + + align:start position:0% +that give a simplified explanation of + + + align:start position:0% +that give a simplified explanation of +how a complicated thing actually works + + align:start position:0% +how a complicated thing actually works + + + align:start position:0% +how a complicated thing actually works +so how many of you have read these + + align:start position:0% +so how many of you have read these + + + align:start position:0% +so how many of you have read these +stories when you were a kid nobody my + + align:start position:0% +stories when you were a kid nobody my + + + align:start position:0% +stories when you were a kid nobody my +god okay must be a generational thing + + align:start position:0% +god okay must be a generational thing + + + align:start position:0% +god okay must be a generational thing +so Rudyard Kipling was a famous author + + align:start position:0% +so Rudyard Kipling was a famous author + + + align:start position:0% +so Rudyard Kipling was a famous author +and he wrote the series of just-so + + align:start position:0% +and he wrote the series of just-so + + + align:start position:0% +and he wrote the series of just-so +stories things like how the lion got his + + align:start position:0% +stories things like how the lion got his + + + align:start position:0% +stories things like how the lion got his +mane and how the camel got his hump and + + align:start position:0% +mane and how the camel got his hump and + + + align:start position:0% +mane and how the camel got his hump and +so on and of course they're all total + + align:start position:0% +so on and of course they're all total + + + align:start position:0% +so on and of course they're all total +bull right I mean it's not a Darwinian + + align:start position:0% +bull right I mean it's not a Darwinian + + + align:start position:0% +bull right I mean it's not a Darwinian +evolutionary explanation of why male + + align:start position:0% +evolutionary explanation of why male + + + align:start position:0% +evolutionary explanation of why male +lions have Mane's it's just some made-up + + align:start position:0% +lions have Mane's it's just some made-up + + + align:start position:0% +lions have Mane's it's just some made-up +story but they're really cute stories + + align:start position:0% +story but they're really cute stories + + + align:start position:0% +story but they're really cute stories +and and I enjoyed them as a kid and + + align:start position:0% +and and I enjoyed them as a kid and + + + align:start position:0% +and and I enjoyed them as a kid and +maybe you would have to if your parents + + align:start position:0% +maybe you would have to if your parents + + + align:start position:0% +maybe you would have to if your parents +had read them to you so I mean I use + + align:start position:0% +had read them to you so I mean I use + + + align:start position:0% +had read them to you so I mean I use +this as a kind of pejorative because + + align:start position:0% +this as a kind of pejorative because + + + align:start position:0% +this as a kind of pejorative because +what the people who follow this line of + + align:start position:0% +what the people who follow this line of + + + align:start position:0% +what the people who follow this line of +investigation do is they take some very + + align:start position:0% +investigation do is they take some very + + + align:start position:0% +investigation do is they take some very +complicated model they make a local + + align:start position:0% +complicated model they make a local + + + align:start position:0% +complicated model they make a local +approximation to it that says this is + + align:start position:0% +approximation to it that says this is + + + align:start position:0% +approximation to it that says this is +not an approximation to the entire model + + align:start position:0% +not an approximation to the entire model + + + align:start position:0% +not an approximation to the entire model +but it's an approximation to the model + + align:start position:0% +but it's an approximation to the model + + + align:start position:0% +but it's an approximation to the model +in the vicinity of a particular case and + + align:start position:0% +in the vicinity of a particular case and + + + align:start position:0% +in the vicinity of a particular case and +then they explain that simplified model + + align:start position:0% +then they explain that simplified model + + + align:start position:0% +then they explain that simplified model +and I'll show you some examples of that + + align:start position:0% +and I'll show you some examples of that + + + align:start position:0% +and I'll show you some examples of that +through the lecture today and the other + + align:start position:0% +through the lecture today and the other + + + align:start position:0% +through the lecture today and the other +approach which I'll also show you some + + align:start position:0% +approach which I'll also show you some + + + align:start position:0% +approach which I'll also show you some +examples of is that you simply trade off + + align:start position:0% +examples of is that you simply trade off + + + align:start position:0% +examples of is that you simply trade off +somewhat lower performance + + align:start position:0% +somewhat lower performance + + + align:start position:0% +somewhat lower performance +for simple model that's simple enough to + + align:start position:0% +for simple model that's simple enough to + + + align:start position:0% +for simple model that's simple enough to +be able to explain so things like + + align:start position:0% +be able to explain so things like + + + align:start position:0% +be able to explain so things like +decision trees and and logistic + + align:start position:0% +decision trees and and logistic + + + align:start position:0% +decision trees and and logistic +regression and so on typically don't + + align:start position:0% +regression and so on typically don't + + + align:start position:0% +regression and so on typically don't +perform quite as well as the best most + + align:start position:0% +perform quite as well as the best most + + + align:start position:0% +perform quite as well as the best most +sophisticated models although you've + + align:start position:0% +sophisticated models although you've + + + align:start position:0% +sophisticated models although you've +seen plenty of examples in this class + + align:start position:0% +seen plenty of examples in this class + + + align:start position:0% +seen plenty of examples in this class +where in fact they do perform quite well + + align:start position:0% +where in fact they do perform quite well + + + align:start position:0% +where in fact they do perform quite well +and where they're not outperformed by + + align:start position:0% +and where they're not outperformed by + + + align:start position:0% +and where they're not outperformed by +the fancy models but in general you can + + align:start position:0% +the fancy models but in general you can + + + align:start position:0% +the fancy models but in general you can +do a little better by tweaking a fancy + + align:start position:0% +do a little better by tweaking a fancy + + + align:start position:0% +do a little better by tweaking a fancy +model but then it becomes + + align:start position:0% +model but then it becomes + + + align:start position:0% +model but then it becomes +incomprehensible and so people are + + align:start position:0% +incomprehensible and so people are + + + align:start position:0% +incomprehensible and so people are +willing to say okay I'm gonna give up 1% + + align:start position:0% +willing to say okay I'm gonna give up 1% + + + align:start position:0% +willing to say okay I'm gonna give up 1% +or 2% in performance in order to have a + + align:start position:0% +or 2% in performance in order to have a + + + align:start position:0% +or 2% in performance in order to have a +model that I can really understand and + + align:start position:0% +model that I can really understand and + + + align:start position:0% +model that I can really understand and +the reason it makes sense is because + + align:start position:0% +the reason it makes sense is because + + + align:start position:0% +the reason it makes sense is because +these models are not self-executing + + align:start position:0% +these models are not self-executing + + + align:start position:0% +these models are not self-executing +they're typically used as advice for + + align:start position:0% +they're typically used as advice for + + + align:start position:0% +they're typically used as advice for +some human being who makes ultimate + + align:start position:0% +some human being who makes ultimate + + + align:start position:0% +some human being who makes ultimate +decisions your surgeon is not going to + + align:start position:0% +decisions your surgeon is not going to + + + align:start position:0% +decisions your surgeon is not going to +look at one of these models that says + + align:start position:0% +look at one of these models that says + + + align:start position:0% +look at one of these models that says +take out the guy's left kidney and say + + align:start position:0% +take out the guy's left kidney and say + + + align:start position:0% +take out the guy's left kidney and say +okay my guess they're gonna go well does + + align:start position:0% +okay my guess they're gonna go well does + + + align:start position:0% +okay my guess they're gonna go well does +that make sense and in order to answer + + align:start position:0% +that make sense and in order to answer + + + align:start position:0% +that make sense and in order to answer +the question of does that make sense it + + align:start position:0% +the question of does that make sense it + + + align:start position:0% +the question of does that make sense it +really helps to know what the model was + + align:start position:0% +really helps to know what the model was + + + align:start position:0% +really helps to know what the model was +what what the models recommendation is + + align:start position:0% +what what the models recommendation is + + + align:start position:0% +what what the models recommendation is +based on what is its internal logic and + + align:start position:0% +based on what is its internal logic and + + + align:start position:0% +based on what is its internal logic and +so even an approximation to that is + + align:start position:0% +so even an approximation to that is + + + align:start position:0% +so even an approximation to that is +useful so the need for trust clinical + + align:start position:0% +useful so the need for trust clinical + + + align:start position:0% +useful so the need for trust clinical +adoption of ML models there are two + + align:start position:0% +adoption of ML models there are two + + + align:start position:0% +adoption of ML models there are two +approaches in this paper that I'm going + + align:start position:0% +approaches in this paper that I'm going + + + align:start position:0% +approaches in this paper that I'm going +to talk about where they say okay what + + align:start position:0% +to talk about where they say okay what + + + align:start position:0% +to talk about where they say okay what +you'd like to do is to look at case + + align:start position:0% +you'd like to do is to look at case + + + align:start position:0% +you'd like to do is to look at case +specific predictions so there's a + + align:start position:0% +specific predictions so there's a + + + align:start position:0% +specific predictions so there's a +particular patient in a particular state + + align:start position:0% +particular patient in a particular state + + + align:start position:0% +particular patient in a particular state +and you want to understand what the + + align:start position:0% +and you want to understand what the + + + align:start position:0% +and you want to understand what the +model is saying about that patient and + + align:start position:0% +model is saying about that patient and + + + align:start position:0% +model is saying about that patient and +then you also want to have confidence in + + align:start position:0% +then you also want to have confidence in + + + align:start position:0% +then you also want to have confidence in +the model overall and so you'd like to + + align:start position:0% +the model overall and so you'd like to + + + align:start position:0% +the model overall and so you'd like to +be able to have an explanatory + + align:start position:0% +be able to have an explanatory + + + align:start position:0% +be able to have an explanatory +capability that says here are some + + align:start position:0% +capability that says here are some + + + align:start position:0% +capability that says here are some +interesting representative cases and + + align:start position:0% +interesting representative cases and + + + align:start position:0% +interesting representative cases and +here's how the model views them look + + align:start position:0% +here's how the model views them look + + + align:start position:0% +here's how the model views them look +through them and decide whether you + + align:start position:0% +through them and decide whether you + + + align:start position:0% +through them and decide whether you +agree with the approach that this model + + align:start position:0% +agree with the approach that this model + + + align:start position:0% +agree with the approach that this model +is take + + align:start position:0% +is take + + + align:start position:0% +is take +now remember my critique of randomized + + align:start position:0% +now remember my critique of randomized + + + align:start position:0% +now remember my critique of randomized +control trials that that people do these + + align:start position:0% +control trials that that people do these + + + align:start position:0% +control trials that that people do these +trials they choose the simplest cases + + align:start position:0% +trials they choose the simplest cases + + + align:start position:0% +trials they choose the simplest cases +the smallest number of patients that + + align:start position:0% +the smallest number of patients that + + + align:start position:0% +the smallest number of patients that +they need in order to reach statistical + + align:start position:0% +they need in order to reach statistical + + + align:start position:0% +they need in order to reach statistical +significance the shortest amount of + + align:start position:0% +significance the shortest amount of + + + align:start position:0% +significance the shortest amount of +follow-up time etc and then the results + + align:start position:0% +follow-up time etc and then the results + + + align:start position:0% +follow-up time etc and then the results +of those trials are applied to very + + align:start position:0% +of those trials are applied to very + + + align:start position:0% +of those trials are applied to very +different populations so david's talked + + align:start position:0% +different populations so david's talked + + + align:start position:0% +different populations so david's talked +about cohort shift as a generalization + + align:start position:0% +about cohort shift as a generalization + + + align:start position:0% +about cohort shift as a generalization +of that idea but the same thing happens + + align:start position:0% +of that idea but the same thing happens + + + align:start position:0% +of that idea but the same thing happens +in these machine learning models that + + align:start position:0% +in these machine learning models that + + + align:start position:0% +in these machine learning models that +you train on some set of data + + align:start position:0% +you train on some set of data + + + align:start position:0% +you train on some set of data +the typical publication will then test + + align:start position:0% +the typical publication will then test + + + align:start position:0% +the typical publication will then test +on some held out subset of the same data + + align:start position:0% +on some held out subset of the same data + + + align:start position:0% +on some held out subset of the same data +but that's not a very accurate + + align:start position:0% +but that's not a very accurate + + + align:start position:0% +but that's not a very accurate +representation of the real world if you + + align:start position:0% +representation of the real world if you + + + align:start position:0% +representation of the real world if you +then try to apply that model to data + + align:start position:0% +then try to apply that model to data + + + align:start position:0% +then try to apply that model to data +from a totally different source the + + align:start position:0% +from a totally different source the + + + align:start position:0% +from a totally different source the +chances are you will have specialized it + + align:start position:0% +chances are you will have specialized it + + + align:start position:0% +chances are you will have specialized it +in some way that you don't appreciate + + align:start position:0% +in some way that you don't appreciate + + + align:start position:0% +in some way that you don't appreciate +and the results that you get are not as + + align:start position:0% +and the results that you get are not as + + + align:start position:0% +and the results that you get are not as +good as what you got on the held-out + + align:start position:0% +good as what you got on the held-out + + + align:start position:0% +good as what you got on the held-out +test data because it's more + + align:start position:0% +test data because it's more + + + align:start position:0% +test data because it's more +heterogeneous I think I mentioned that + + align:start position:0% +heterogeneous I think I mentioned that + + + align:start position:0% +heterogeneous I think I mentioned that +Jeff Drazen the editor-in-chief of the + + align:start position:0% +Jeff Drazen the editor-in-chief of the + + + align:start position:0% +Jeff Drazen the editor-in-chief of the +New England Journal had a meeting about + + align:start position:0% +New England Journal had a meeting about + + + align:start position:0% +New England Journal had a meeting about +about a year ago in which he was arguing + + align:start position:0% +about a year ago in which he was arguing + + + align:start position:0% +about a year ago in which he was arguing +that the journal shouldn't ever publish + + align:start position:0% +that the journal shouldn't ever publish + + + align:start position:0% +that the journal shouldn't ever publish +a research study unless it's been + + align:start position:0% +a research study unless it's been + + + align:start position:0% +a research study unless it's been +validated on two independent data sets + + align:start position:0% +validated on two independent data sets + + + align:start position:0% +validated on two independent data sets +because he he's tired of publishing + + align:start position:0% +because he he's tired of publishing + + + align:start position:0% +because he he's tired of publishing +studies that wind up getting retracted + + align:start position:0% +studies that wind up getting retracted + + + align:start position:0% +studies that wind up getting retracted +because not because of any overt badness + + align:start position:0% +because not because of any overt badness + + + align:start position:0% +because not because of any overt badness +on the part of the investigators they've + + align:start position:0% +on the part of the investigators they've + + + align:start position:0% +on the part of the investigators they've +done exactly the kinds of things that + + align:start position:0% +done exactly the kinds of things that + + + align:start position:0% +done exactly the kinds of things that +you've learned how to do in this class + + align:start position:0% +you've learned how to do in this class + + + align:start position:0% +you've learned how to do in this class +but when they go to apply that model to + + align:start position:0% +but when they go to apply that model to + + + align:start position:0% +but when they go to apply that model to +a different population it just doesn't + + align:start position:0% +a different population it just doesn't + + + align:start position:0% +a different population it just doesn't +work nearly as well as it did in the + + align:start position:0% +work nearly as well as it did in the + + + align:start position:0% +work nearly as well as it did in the +published version and of course they're + + align:start position:0% +published version and of course they're + + + align:start position:0% +published version and of course they're +all the publication bias issues about + + align:start position:0% +all the publication bias issues about + + + align:start position:0% +all the publication bias issues about +you know if if 50 of us do the same + + align:start position:0% +you know if if 50 of us do the same + + + align:start position:0% +you know if if 50 of us do the same +experiment and by random chance some of + + align:start position:0% +experiment and by random chance some of + + + align:start position:0% +experiment and by random chance some of +us are going to get better results than + + align:start position:0% +us are going to get better results than + + + align:start position:0% +us are going to get better results than +others and those are the ones that + + align:start position:0% +others and those are the ones that + + + align:start position:0% +others and those are the ones that +I get published because the people who + + align:start position:0% +I get published because the people who + + + align:start position:0% +I get published because the people who +got poor results don't have anything + + align:start position:0% +got poor results don't have anything + + + align:start position:0% +got poor results don't have anything +interesting to report and so there's + + align:start position:0% +interesting to report and so there's + + + align:start position:0% +interesting to report and so there's +that whole issue of publication bias + + align:start position:0% +that whole issue of publication bias + + + align:start position:0% +that whole issue of publication bias +which is another serious one okay so I + + align:start position:0% +which is another serious one okay so I + + + align:start position:0% +which is another serious one okay so I +wanted to just spend a minute to say you + + align:start position:0% +wanted to just spend a minute to say you + + + align:start position:0% +wanted to just spend a minute to say you +know explanation is not a new idea so in + + align:start position:0% +know explanation is not a new idea so in + + + align:start position:0% +know explanation is not a new idea so in +the expert system zero that we talked + + align:start position:0% +the expert system zero that we talked + + + align:start position:0% +the expert system zero that we talked +about a little bit in one of one of our + + align:start position:0% +about a little bit in one of one of our + + + align:start position:0% +about a little bit in one of one of our +earlier classes we talked about the idea + + align:start position:0% +earlier classes we talked about the idea + + + align:start position:0% +earlier classes we talked about the idea +that we would take medical human medical + + align:start position:0% +that we would take medical human medical + + + align:start position:0% +that we would take medical human medical +experts and debrief them of what they + + align:start position:0% +experts and debrief them of what they + + + align:start position:0% +experts and debrief them of what they +knew and then try to encode those in + + align:start position:0% +knew and then try to encode those in + + + align:start position:0% +knew and then try to encode those in +patterns or in rules or in various ways + + align:start position:0% +patterns or in rules or in various ways + + + align:start position:0% +patterns or in rules or in various ways +in a computer program in order to + + align:start position:0% +in a computer program in order to + + + align:start position:0% +in a computer program in order to +reproduce their behavior so my son was + + align:start position:0% +reproduce their behavior so my son was + + + align:start position:0% +reproduce their behavior so my son was +one of those programs petroglyphs PhD + + align:start position:0% +one of those programs petroglyphs PhD + + + align:start position:0% +one of those programs petroglyphs PhD +thesis in 1975 and they published this + + align:start position:0% +thesis in 1975 and they published this + + + align:start position:0% +thesis in 1975 and they published this +nice paper that was about explanation + + align:start position:0% +nice paper that was about explanation + + + align:start position:0% +nice paper that was about explanation +and rule acquisition capabilities of the + + align:start position:0% +and rule acquisition capabilities of the + + + align:start position:0% +and rule acquisition capabilities of the +Meissen system and as an illustration + + align:start position:0% +Meissen system and as an illustration + + + align:start position:0% +Meissen system and as an illustration +they gave some examples of what you + + align:start position:0% +they gave some examples of what you + + + align:start position:0% +they gave some examples of what you +could do with the system so rules they + + align:start position:0% +could do with the system so rules they + + + align:start position:0% +could do with the system so rules they +argued were quite understandable because + + align:start position:0% +argued were quite understandable because + + + align:start position:0% +argued were quite understandable because +they say if a bunch of conditions then + + align:start position:0% +they say if a bunch of conditions then + + + align:start position:0% +they say if a bunch of conditions then +you can draw the following conclusion + + align:start position:0% +you can draw the following conclusion + + + align:start position:0% +you can draw the following conclusion +right so given that you can say well + + align:start position:0% +right so given that you can say well + + + align:start position:0% +right so given that you can say well +when the program comes back and says in + + align:start position:0% +when the program comes back and says in + + + align:start position:0% +when the program comes back and says in +light of the site from which the culture + + align:start position:0% +light of the site from which the culture + + + align:start position:0% +light of the site from which the culture +was obtained and the method of + + align:start position:0% +was obtained and the method of + + + align:start position:0% +was obtained and the method of +collection do you feel that a + + align:start position:0% +collection do you feel that a + + + align:start position:0% +collection do you feel that a +significant number of organism one were + + align:start position:0% +significant number of organism one were + + + align:start position:0% +significant number of organism one were +detected were obtained right in other + + align:start position:0% +detected were obtained right in other + + + align:start position:0% +detected were obtained right in other +words if you took a sample from + + align:start position:0% +words if you took a sample from + + + align:start position:0% +words if you took a sample from +somebody's body and you're looking for + + align:start position:0% +somebody's body and you're looking for + + + align:start position:0% +somebody's body and you're looking for +an infection do you think you got enough + + align:start position:0% +an infection do you think you got enough + + + align:start position:0% +an infection do you think you got enough +organisms in that sample and the user + + align:start position:0% +organisms in that sample and the user + + + align:start position:0% +organisms in that sample and the user +says well why are you asking that me + + align:start position:0% +says well why are you asking that me + + + align:start position:0% +says well why are you asking that me +this question and the answer in terms of + + align:start position:0% +this question and the answer in terms of + + + align:start position:0% +this question and the answer in terms of +the rules that the system works by is + + align:start position:0% +the rules that the system works by is + + + align:start position:0% +the rules that the system works by is +pretty good it says it's important to + + align:start position:0% +pretty good it says it's important to + + + align:start position:0% +pretty good it says it's important to +find out whether there's therapeutically + + align:start position:0% +find out whether there's therapeutically + + + align:start position:0% +find out whether there's therapeutically +significant disease associated with this + + align:start position:0% +significant disease associated with this + + + align:start position:0% +significant disease associated with this +occurrence of organism one we've already + + align:start position:0% +occurrence of organism one we've already + + + align:start position:0% +occurrence of organism one we've already +established that the culture + + align:start position:0% +established that the culture + + + align:start position:0% +established that the culture +is not one of those that are normally + + align:start position:0% +is not one of those that are normally + + + align:start position:0% +is not one of those that are normally +sterile and the method of collection is + + align:start position:0% +sterile and the method of collection is + + + align:start position:0% +sterile and the method of collection is +sterile + + align:start position:0% +sterile + + + align:start position:0% +sterile +therefore if the organism has been + + align:start position:0% +therefore if the organism has been + + + align:start position:0% +therefore if the organism has been +observed in significant numbers then + + align:start position:0% +observed in significant numbers then + + + align:start position:0% +observed in significant numbers then +they're strongly suggestive evidence + + align:start position:0% +they're strongly suggestive evidence + + + align:start position:0% +they're strongly suggestive evidence +that there's therapeutically significant + + align:start position:0% +that there's therapeutically significant + + + align:start position:0% +that there's therapeutically significant +disease associated with this occurrence + + align:start position:0% +disease associated with this occurrence + + + align:start position:0% +disease associated with this occurrence +of the organism okay + + align:start position:0% +of the organism okay + + + align:start position:0% +of the organism okay +so if you find bugs in a place carefully + + align:start position:0% +so if you find bugs in a place carefully + + + align:start position:0% +so if you find bugs in a place carefully +collected then that suggests that you + + align:start position:0% +collected then that suggests that you + + + align:start position:0% +collected then that suggests that you +ought to probably treat this patient if + + align:start position:0% +ought to probably treat this patient if + + + align:start position:0% +ought to probably treat this patient if +there are a bunch of enough enough bugs + + align:start position:0% +there are a bunch of enough enough bugs + + + align:start position:0% +there are a bunch of enough enough bugs +there and there's also strongly + + align:start position:0% +there and there's also strongly + + + align:start position:0% +there and there's also strongly +suggestive evidence that the organism is + + align:start position:0% +suggestive evidence that the organism is + + + align:start position:0% +suggestive evidence that the organism is +not a contaminant because the collection + + align:start position:0% +not a contaminant because the collection + + + align:start position:0% +not a contaminant because the collection +method was sterile and you can go on + + align:start position:0% +method was sterile and you can go on + + + align:start position:0% +method was sterile and you can go on +with this and you can say well why did + + align:start position:0% +with this and you can say well why did + + + align:start position:0% +with this and you can say well why did +why why that so why that that question + + align:start position:0% +why why that so why that that question + + + align:start position:0% +why why that so why that that question +and and and it traces back in its + + align:start position:0% +and and and it traces back in its + + + align:start position:0% +and and and it traces back in its +evolution of these rules and it says + + align:start position:0% +evolution of these rules and it says + + + align:start position:0% +evolution of these rules and it says +well in order to find out the locus of + + align:start position:0% +well in order to find out the locus of + + + align:start position:0% +well in order to find out the locus of +infection it's already been established + + align:start position:0% +infection it's already been established + + + align:start position:0% +infection it's already been established +that the site of the culture is known + + align:start position:0% +that the site of the culture is known + + + align:start position:0% +that the site of the culture is known +the number of days since the specimen + + align:start position:0% +the number of days since the specimen + + + align:start position:0% +the number of days since the specimen +was obtained is less than seven + + align:start position:0% +was obtained is less than seven + + + align:start position:0% +was obtained is less than seven +therefore there's therapeutically + + align:start position:0% +therefore there's therapeutically + + + align:start position:0% +therefore there's therapeutically +significant disease associated with this + + align:start position:0% +significant disease associated with this + + + align:start position:0% +significant disease associated with this +recurrence of the organism so there's + + align:start position:0% +recurrence of the organism so there's + + + align:start position:0% +recurrence of the organism so there's +some rule that says if you got bugs and + + align:start position:0% +some rule that says if you got bugs and + + + align:start position:0% +some rule that says if you got bugs and +it happened within the last seven days + + align:start position:0% +it happened within the last seven days + + + align:start position:0% +it happened within the last seven days +the patient probably really does have an + + align:start position:0% +the patient probably really does have an + + + align:start position:0% +the patient probably really does have an +infection right so and I mean I've got a + + align:start position:0% +infection right so and I mean I've got a + + + align:start position:0% +infection right so and I mean I've got a +lot of examples of this but you can keep + + align:start position:0% +lot of examples of this but you can keep + + + align:start position:0% +lot of examples of this but you can keep +going why you know this is the + + align:start position:0% +going why you know this is the + + + align:start position:0% +going why you know this is the +two-year-old but why daddy but why but + + align:start position:0% +two-year-old but why daddy but why but + + + align:start position:0% +two-year-old but why daddy but why but +why well why is it important to find out + + align:start position:0% +why well why is it important to find out + + + align:start position:0% +why well why is it important to find out +a locus of infection and well there's a + + align:start position:0% +a locus of infection and well there's a + + + align:start position:0% +a locus of infection and well there's a +reason which is that there's a rule that + + align:start position:0% +reason which is that there's a rule that + + + align:start position:0% +reason which is that there's a rule that +will conclude for example that the + + align:start position:0% +will conclude for example that the + + + align:start position:0% +will conclude for example that the +abdomen is a locus of infection or the + + align:start position:0% +abdomen is a locus of infection or the + + + align:start position:0% +abdomen is a locus of infection or the +pelvis as a locus of infection of the + + align:start position:0% +pelvis as a locus of infection of the + + + align:start position:0% +pelvis as a locus of infection of the +patient if you satisfy these these + + align:start position:0% +patient if you satisfy these these + + + align:start position:0% +patient if you satisfy these these +criteria and so this is a kind of + + align:start position:0% +criteria and so this is a kind of + + + align:start position:0% +criteria and so this is a kind of +rudimentary explanation that comes + + align:start position:0% +rudimentary explanation that comes + + + align:start position:0% +rudimentary explanation that comes +directly out of the fact that these are + + align:start position:0% +directly out of the fact that these are + + + align:start position:0% +directly out of the fact that these are +rule based system + + align:start position:0% +rule based system + + + align:start position:0% +rule based system +and so you can just play back the rules + + align:start position:0% +and so you can just play back the rules + + + align:start position:0% +and so you can just play back the rules +one of the things I like is you can also + + align:start position:0% +one of the things I like is you can also + + + align:start position:0% +one of the things I like is you can also +ask freeform questions 1975 the natural + + align:start position:0% +ask freeform questions 1975 the natural + + + align:start position:0% +ask freeform questions 1975 the natural +language processing was not so good and + + align:start position:0% +language processing was not so good and + + + align:start position:0% +language processing was not so good and +so this worked about one time in five + + align:start position:0% +so this worked about one time in five + + + align:start position:0% +so this worked about one time in five +but you could walk up to it and type + + align:start position:0% +but you could walk up to it and type + + + align:start position:0% +but you could walk up to it and type +some question and for example do you + + align:start position:0% +some question and for example do you + + + align:start position:0% +some question and for example do you +ever prescribe carbon a salon for + + align:start position:0% +ever prescribe carbon a salon for + + + align:start position:0% +ever prescribe carbon a salon for +Pseudomonas infections and it says well + + align:start position:0% +Pseudomonas infections and it says well + + + align:start position:0% +Pseudomonas infections and it says well +there are three rules in my database of + + align:start position:0% +there are three rules in my database of + + + align:start position:0% +there are three rules in my database of +rules that would conclude something + + align:start position:0% +rules that would conclude something + + + align:start position:0% +rules that would conclude something +relevant to that question so which one + + align:start position:0% +relevant to that question so which one + + + align:start position:0% +relevant to that question so which one +do you want to see and if you say I want + + align:start position:0% +do you want to see and if you say I want + + + align:start position:0% +do you want to see and if you say I want +to see rule 64 it says while that rule + + align:start position:0% +to see rule 64 it says while that rule + + + align:start position:0% +to see rule 64 it says while that rule +says if it's known with certainty that + + align:start position:0% +says if it's known with certainty that + + + align:start position:0% +says if it's known with certainty that +the organism is a pseudo Pseudomonas and + + align:start position:0% +the organism is a pseudo Pseudomonas and + + + align:start position:0% +the organism is a pseudo Pseudomonas and +the drug under consideration is + + align:start position:0% +the drug under consideration is + + + align:start position:0% +the drug under consideration is +gentamicin then a more appropriate + + align:start position:0% +gentamicin then a more appropriate + + + align:start position:0% +gentamicin then a more appropriate +therapy would be a combination of + + align:start position:0% +therapy would be a combination of + + + align:start position:0% +therapy would be a combination of +gentamicin and carvanha Siwan again this + + align:start position:0% +gentamicin and carvanha Siwan again this + + + align:start position:0% +gentamicin and carvanha Siwan again this +is medical knowledge as of 1975 but my + + align:start position:0% +is medical knowledge as of 1975 but my + + + align:start position:0% +is medical knowledge as of 1975 but my +guess is the real underlying reason is + + align:start position:0% +guess is the real underlying reason is + + + align:start position:0% +guess is the real underlying reason is +that there are probably worse + + align:start position:0% +that there are probably worse + + + align:start position:0% +that there are probably worse +Pseudomonas that were resistant by that + + align:start position:0% +Pseudomonas that were resistant by that + + + align:start position:0% +Pseudomonas that were resistant by that +point to gentamicin and so they used a + + align:start position:0% +point to gentamicin and so they used a + + + align:start position:0% +point to gentamicin and so they used a +combination therapy now notice by the + + align:start position:0% +combination therapy now notice by the + + + align:start position:0% +combination therapy now notice by the +way that this explanation capability + + align:start position:0% +way that this explanation capability + + + align:start position:0% +way that this explanation capability +does not tell you that right because it + + align:start position:0% +does not tell you that right because it + + + align:start position:0% +does not tell you that right because it +doesn't actually understand the + + align:start position:0% +doesn't actually understand the + + + align:start position:0% +doesn't actually understand the +rationale behind these individual rules + + align:start position:0% +rationale behind these individual rules + + + align:start position:0% +rationale behind these individual rules +and at the time there was also research + + align:start position:0% +and at the time there was also research + + + align:start position:0% +and at the time there was also research +for example by one of my students on how + + align:start position:0% +for example by one of my students on how + + + align:start position:0% +for example by one of my students on how +to do a better job of that by by + + align:start position:0% +to do a better job of that by by + + + align:start position:0% +to do a better job of that by by +encoding not only the rules or the + + align:start position:0% +encoding not only the rules or the + + + align:start position:0% +encoding not only the rules or the +patterns but also the rationale behind + + align:start position:0% +patterns but also the rationale behind + + + align:start position:0% +patterns but also the rationale behind +them so that the explanations could be + + align:start position:0% +them so that the explanations could be + + + align:start position:0% +them so that the explanations could be +more sensible + + align:start position:0% +more sensible + + + align:start position:0% +more sensible +okay well the granddaddy of the standard + + align:start position:0% +okay well the granddaddy of the standard + + + align:start position:0% +okay well the granddaddy of the standard +just so story approach to explanation of + + align:start position:0% +just so story approach to explanation of + + + align:start position:0% +just so story approach to explanation of +complex models today comes from this + + align:start position:0% +complex models today comes from this + + + align:start position:0% +complex models today comes from this +paper and a system called Lyme locally + + align:start position:0% +paper and a system called Lyme locally + + + align:start position:0% +paper and a system called Lyme locally +interpretable model agnostic + + align:start position:0% +interpretable model agnostic + + + align:start position:0% +interpretable model agnostic +explanations and just to give you an + + align:start position:0% +explanations and just to give you an + + + align:start position:0% +explanations and just to give you an +illustration you have some complicated + + align:start position:0% +illustration you have some complicated + + + align:start position:0% +illustration you have some complicated +model and it's trying to explain why the + + align:start position:0% +model and it's trying to explain why the + + + align:start position:0% +model and it's trying to explain why the +or human being made a certain decision + + align:start position:0% +or human being made a certain decision + + + align:start position:0% +or human being made a certain decision +or why the model made a certain decision + + align:start position:0% +or why the model made a certain decision + + + align:start position:0% +or why the model made a certain decision +and so it says well here are the data we + + align:start position:0% +and so it says well here are the data we + + + align:start position:0% +and so it says well here are the data we +have about the patient we know that the + + align:start position:0% +have about the patient we know that the + + + align:start position:0% +have about the patient we know that the +patient is sneezing and we know their + + align:start position:0% +patient is sneezing and we know their + + + align:start position:0% +patient is sneezing and we know their +weight and their headache and their age + + align:start position:0% +weight and their headache and their age + + + align:start position:0% +weight and their headache and their age +and the fact that they have no fatigue + + align:start position:0% +and the fact that they have no fatigue + + + align:start position:0% +and the fact that they have no fatigue +and so the explainer says well why did + + align:start position:0% +and so the explainer says well why did + + + align:start position:0% +and so the explainer says well why did +the model decide this patient has the + + align:start position:0% +the model decide this patient has the + + + align:start position:0% +the model decide this patient has the +flu + + align:start position:0% +flu + + + align:start position:0% +flu +well positives are sneeze and headache + + align:start position:0% +well positives are sneeze and headache + + + align:start position:0% +well positives are sneeze and headache +and a negative is no fatigue right so it + + align:start position:0% +and a negative is no fatigue right so it + + + align:start position:0% +and a negative is no fatigue right so it +goes into this complicated model and it + + align:start position:0% +goes into this complicated model and it + + + align:start position:0% +goes into this complicated model and it +says well I can't explain all the + + align:start position:0% +says well I can't explain all the + + + align:start position:0% +says well I can't explain all the +numerology that happens in that the role + + align:start position:0% +numerology that happens in that the role + + + align:start position:0% +numerology that happens in that the role +network or Bayesian network or whatever + + align:start position:0% +network or Bayesian network or whatever + + + align:start position:0% +network or Bayesian network or whatever +network it's being it's using but I can + + align:start position:0% +network it's being it's using but I can + + + align:start position:0% +network it's being it's using but I can +specify that it looks like these are the + + align:start position:0% +specify that it looks like these are the + + + align:start position:0% +specify that it looks like these are the +most important positive and negative + + align:start position:0% +most important positive and negative + + + align:start position:0% +most important positive and negative +contributors yeah I'll show you some + + align:start position:0% +contributors yeah I'll show you some + + + align:start position:0% +contributors yeah I'll show you some +other kind of data and in a minute I + + align:start position:0% +other kind of data and in a minute I + + + align:start position:0% +other kind of data and in a minute I +think they originally worked it out for + + align:start position:0% +think they originally worked it out for + + + align:start position:0% +think they originally worked it out for +notes but it was also used for images + + align:start position:0% +notes but it was also used for images + + + align:start position:0% +notes but it was also used for images +and other as well okay and the argument + + align:start position:0% +and other as well okay and the argument + + + align:start position:0% +and other as well okay and the argument +they make is that this approach also + + align:start position:0% +they make is that this approach also + + + align:start position:0% +they make is that this approach also +helps to detect data leakage for example + + align:start position:0% +helps to detect data leakage for example + + + align:start position:0% +helps to detect data leakage for example +in one of their experiments the the + + align:start position:0% +in one of their experiments the the + + + align:start position:0% +in one of their experiments the the +headers of the data had information in + + align:start position:0% +headers of the data had information in + + + align:start position:0% +headers of the data had information in +them that that correlated highly with + + align:start position:0% +them that that correlated highly with + + + align:start position:0% +them that that correlated highly with +the result I think they're I can't + + align:start position:0% +the result I think they're I can't + + + align:start position:0% +the result I think they're I can't +remember if it was these guys but + + align:start position:0% +remember if it was these guys but + + + align:start position:0% +remember if it was these guys but +somebody was assigning study IDs to each + + align:start position:0% +somebody was assigning study IDs to each + + + align:start position:0% +somebody was assigning study IDs to each +case and they did it in a stupid way so + + align:start position:0% +case and they did it in a stupid way so + + + align:start position:0% +case and they did it in a stupid way so +that all the small numbers correspond it + + align:start position:0% +that all the small numbers correspond it + + + align:start position:0% +that all the small numbers correspond it +to people who had the disease and the + + align:start position:0% +to people who had the disease and the + + + align:start position:0% +to people who had the disease and the +big numbers correspond it to the people + + align:start position:0% +big numbers correspond it to the people + + + align:start position:0% +big numbers correspond it to the people +who didn't and of course the most + + align:start position:0% +who didn't and of course the most + + + align:start position:0% +who didn't and of course the most +parsimonious predictive model just used + + align:start position:0% +parsimonious predictive model just used + + + align:start position:0% +parsimonious predictive model just used +the ID number and said okay I got it so + + align:start position:0% +the ID number and said okay I got it so + + + align:start position:0% +the ID number and said okay I got it so +this would help you identify that + + align:start position:0% +this would help you identify that + + + align:start position:0% +this would help you identify that +because if you see that the best + + align:start position:0% +because if you see that the best + + + align:start position:0% +because if you see that the best +predictor is the ID + + align:start position:0% +predictor is the ID + + + align:start position:0% +predictor is the ID +number then you would say there's + + align:start position:0% +number then you would say there's + + + align:start position:0% +number then you would say there's +something a little fishy going on here + + align:start position:0% +something a little fishy going on here + + + align:start position:0% +something a little fishy going on here +well so here's an example where this + + align:start position:0% +well so here's an example where this + + + align:start position:0% +well so here's an example where this +kind of capability is very useful so + + align:start position:0% +kind of capability is very useful so + + + align:start position:0% +kind of capability is very useful so +this was another this was from a news + + align:start position:0% +this was another this was from a news + + + align:start position:0% +this was another this was from a news +group and they were trying to decide + + align:start position:0% +group and they were trying to decide + + + align:start position:0% +group and they were trying to decide +whether a post was about christianity or + + align:start position:0% +whether a post was about christianity or + + + align:start position:0% +whether a post was about christianity or +atheism okay now look at these two + + align:start position:0% +atheism okay now look at these two + + + align:start position:0% +atheism okay now look at these two +models + + align:start position:0% +models + + + align:start position:0% +models +so there's algorithm one an algorithm - + + align:start position:0% +so there's algorithm one an algorithm - + + + align:start position:0% +so there's algorithm one an algorithm - +or model one and model two and when you + + align:start position:0% +or model one and model two and when you + + + align:start position:0% +or model one and model two and when you +explain a particular case about using + + align:start position:0% +explain a particular case about using + + + align:start position:0% +explain a particular case about using +model one it says well the words that I + + align:start position:0% +model one it says well the words that I + + + align:start position:0% +model one it says well the words that I +consider important are God mean anyone + + align:start position:0% +consider important are God mean anyone + + + align:start position:0% +consider important are God mean anyone +this Koresh and through does there + + align:start position:0% +this Koresh and through does there + + + align:start position:0% +this Koresh and through does there +anybody remember who David Koresh was he + + align:start position:0% +anybody remember who David Koresh was he + + + align:start position:0% +anybody remember who David Koresh was he +was some cult leader who I can't + + align:start position:0% +was some cult leader who I can't + + + align:start position:0% +was some cult leader who I can't +remember if if he killed a bunch of + + align:start position:0% +remember if if he killed a bunch of + + + align:start position:0% +remember if if he killed a bunch of +people or bad things happened oh I think + + align:start position:0% +people or bad things happened oh I think + + + align:start position:0% +people or bad things happened oh I think +he was the guy in Waco Texas that the + + align:start position:0% +he was the guy in Waco Texas that the + + + align:start position:0% +he was the guy in Waco Texas that the +FBI and the ATF went in and and set + + align:start position:0% +FBI and the ATF went in and and set + + + align:start position:0% +FBI and the ATF went in and and set +their place on fire and a whole bunch of + + align:start position:0% +their place on fire and a whole bunch of + + + align:start position:0% +their place on fire and a whole bunch of +people died so the prediction in this + + align:start position:0% +people died so the prediction in this + + + align:start position:0% +people died so the prediction in this +case is atheism and you notice that God + + align:start position:0% +case is atheism and you notice that God + + + align:start position:0% +case is atheism and you notice that God +and Koresh and mean are negatives and + + align:start position:0% +and Koresh and mean are negatives and + + + align:start position:0% +and Koresh and mean are negatives and +anyone this and through our positives + + align:start position:0% +anyone this and through our positives + + + align:start position:0% +anyone this and through our positives +and you go + + align:start position:0% +and you go + + + align:start position:0% +and you go +is that good but then you look at + + align:start position:0% +is that good but then you look at + + + align:start position:0% +is that good but then you look at +algorithm two and you say this also made + + align:start position:0% +algorithm two and you say this also made + + + align:start position:0% +algorithm two and you say this also made +the correct prediction which is that + + align:start position:0% +the correct prediction which is that + + + align:start position:0% +the correct prediction which is that +this particular article is about atheism + + align:start position:0% +this particular article is about atheism + + + align:start position:0% +this particular article is about atheism +but the positives were the word by and + + align:start position:0% +but the positives were the word by and + + + align:start position:0% +but the positives were the word by and +in not not terribly specific and the + + align:start position:0% +in not not terribly specific and the + + + align:start position:0% +in not not terribly specific and the +negatives were things like nntp you know + + align:start position:0% +negatives were things like nntp you know + + + align:start position:0% +negatives were things like nntp you know +what that is that's the network time + + align:start position:0% +what that is that's the network time + + + align:start position:0% +what that is that's the network time +protocol okay it's some technical thing + + align:start position:0% +protocol okay it's some technical thing + + + align:start position:0% +protocol okay it's some technical thing +and posting and host so this is probably + + align:start position:0% +and posting and host so this is probably + + + align:start position:0% +and posting and host so this is probably +like metadata that got into the header + + align:start position:0% +like metadata that got into the header + + + align:start position:0% +like metadata that got into the header +of the articles or something so + + align:start position:0% +of the articles or something so + + + align:start position:0% +of the articles or something so +it happened that in this case algorithm + + align:start position:0% +it happened that in this case algorithm + + + align:start position:0% +it happened that in this case algorithm +two turned out to be more accurate than + + align:start position:0% +two turned out to be more accurate than + + + align:start position:0% +two turned out to be more accurate than +algorithm one on their held-out test + + align:start position:0% +algorithm one on their held-out test + + + align:start position:0% +algorithm one on their held-out test +data but not for any good reason and so + + align:start position:0% +data but not for any good reason and so + + + align:start position:0% +data but not for any good reason and so +the explanation capability allows you to + + align:start position:0% +the explanation capability allows you to + + + align:start position:0% +the explanation capability allows you to +clue in on the fact that even though + + align:start position:0% +clue in on the fact that even though + + + align:start position:0% +clue in on the fact that even though +this thing is getting the right answers + + align:start position:0% +this thing is getting the right answers + + + align:start position:0% +this thing is getting the right answers +it's not for sensible reasons okay so + + align:start position:0% +it's not for sensible reasons okay so + + + align:start position:0% +it's not for sensible reasons okay so +what would you like from an explanation + + align:start position:0% +what would you like from an explanation + + + align:start position:0% +what would you like from an explanation +well they say you'd like it to be + + align:start position:0% +well they say you'd like it to be + + + align:start position:0% +well they say you'd like it to be +interpretable so it should provide + + align:start position:0% +interpretable so it should provide + + + align:start position:0% +interpretable so it should provide +qualitative understanding of the + + align:start position:0% +qualitative understanding of the + + + align:start position:0% +qualitative understanding of the +relationship between the input variables + + align:start position:0% +relationship between the input variables + + + align:start position:0% +relationship between the input variables +and the response but they also say that + + align:start position:0% +and the response but they also say that + + + align:start position:0% +and the response but they also say that +that's going to depend on the audience + + align:start position:0% +that's going to depend on the audience + + + align:start position:0% +that's going to depend on the audience +it requires sparsity for the george + + align:start position:0% +it requires sparsity for the george + + + align:start position:0% +it requires sparsity for the george +miller argument that i was making before + + align:start position:0% +miller argument that i was making before + + + align:start position:0% +miller argument that i was making before +you can't keep too many things in mind + + align:start position:0% +you can't keep too many things in mind + + + align:start position:0% +you can't keep too many things in mind +and the features themselves that you're + + align:start position:0% +and the features themselves that you're + + + align:start position:0% +and the features themselves that you're +explaining must make sense so for + + align:start position:0% +explaining must make sense so for + + + align:start position:0% +explaining must make sense so for +example if i say well the reason this + + align:start position:0% +example if i say well the reason this + + + align:start position:0% +example if i say well the reason this +decided that is because the eigenvector + + align:start position:0% +decided that is because the eigenvector + + + align:start position:0% +decided that is because the eigenvector +for the first principal component was + + align:start position:0% +for the first principal component was + + + align:start position:0% +for the first principal component was +the following + + align:start position:0% +the following + + + align:start position:0% +the following +that's not gonna mean much to most + + align:start position:0% +that's not gonna mean much to most + + + align:start position:0% +that's not gonna mean much to most +people and then they also say well it + + align:start position:0% +people and then they also say well it + + + align:start position:0% +people and then they also say well it +ought to have local fidelity so it must + + align:start position:0% +ought to have local fidelity so it must + + + align:start position:0% +ought to have local fidelity so it must +correspond to how the model behaves in + + align:start position:0% +correspond to how the model behaves in + + + align:start position:0% +correspond to how the model behaves in +the vicinity of the particular instance + + align:start position:0% +the vicinity of the particular instance + + + align:start position:0% +the vicinity of the particular instance +that you're trying to explain and their + + align:start position:0% +that you're trying to explain and their + + + align:start position:0% +that you're trying to explain and their +third criterion which i think is a + + align:start position:0% +third criterion which i think is a + + + align:start position:0% +third criterion which i think is a +little iffy er is that it must be model + + align:start position:0% +little iffy er is that it must be model + + + align:start position:0% +little iffy er is that it must be model +agnostic in other words you can't take + + align:start position:0% +agnostic in other words you can't take + + + align:start position:0% +agnostic in other words you can't take +advantage of anything you know that is + + align:start position:0% +advantage of anything you know that is + + + align:start position:0% +advantage of anything you know that is +specific about the structure of the + + align:start position:0% +specific about the structure of the + + + align:start position:0% +specific about the structure of the +model the way you trained it anything + + align:start position:0% +model the way you trained it anything + + + align:start position:0% +model the way you trained it anything +like that it has to be a general-purpose + + align:start position:0% +like that it has to be a general-purpose + + + align:start position:0% +like that it has to be a general-purpose +explainer that works on any kind of + + align:start position:0% +explainer that works on any kind of + + + align:start position:0% +explainer that works on any kind of +complicated model yeah I think their + + align:start position:0% +complicated model yeah I think their + + + align:start position:0% +complicated model yeah I think their +their reasoning for why they insist on + + align:start position:0% +their reasoning for why they insist on + + + align:start position:0% +their reasoning for why they insist on +this is because they don't want to have + + align:start position:0% +this is because they don't want to have + + + align:start position:0% +this is because they don't want to have +to write a separate explainer for each + + align:start position:0% +to write a separate explainer for each + + + align:start position:0% +to write a separate explainer for each +possible model so it's much more + + align:start position:0% +possible model so it's much more + + + align:start position:0% +possible model so it's much more +efficient if you can get this done but I + + align:start position:0% +efficient if you can get this done but I + + + align:start position:0% +efficient if you can get this done but I +actually questioned whether this is + + align:start position:0% +actually questioned whether this is + + + align:start position:0% +actually questioned whether this is +always a good idea or not but + + align:start position:0% +always a good idea or not but + + + align:start position:0% +always a good idea or not but +nevertheless this is one of their + + align:start position:0% +nevertheless this is one of their + + + align:start position:0% +nevertheless this is one of their +assumptions okay so here's the setup + + align:start position:0% +assumptions okay so here's the setup + + + align:start position:0% +assumptions okay so here's the setup +that they use they say all right X is a + + align:start position:0% +that they use they say all right X is a + + + align:start position:0% +that they use they say all right X is a +vector in some D dimensional space that + + align:start position:0% +vector in some D dimensional space that + + + align:start position:0% +vector in some D dimensional space that +defines your original data and what + + align:start position:0% +defines your original data and what + + + align:start position:0% +defines your original data and what +we're gonna do in order to make the data + + align:start position:0% +we're gonna do in order to make the data + + + align:start position:0% +we're gonna do in order to make the data +explainable in order to make the data + + align:start position:0% +explainable in order to make the data + + + align:start position:0% +explainable in order to make the data +not the model explainable is we're going + + align:start position:0% +not the model explainable is we're going + + + align:start position:0% +not the model explainable is we're going +to define a new set of variables X prime + + align:start position:0% +to define a new set of variables X prime + + + align:start position:0% +to define a new set of variables X prime +that are all binary and that are in some + + align:start position:0% +that are all binary and that are in some + + + align:start position:0% +that are all binary and that are in some +space of dimension D prime that is + + align:start position:0% +space of dimension D prime that is + + + align:start position:0% +space of dimension D prime that is +probably lower than D okay so it's we're + + align:start position:0% +probably lower than D okay so it's we're + + + align:start position:0% +probably lower than D okay so it's we're +simplifying the data that we're gonna + + align:start position:0% +simplifying the data that we're gonna + + + align:start position:0% +simplifying the data that we're gonna +explain about this model then they say + + align:start position:0% +explain about this model then they say + + + align:start position:0% +explain about this model then they say +okay we're going to build an explanation + + align:start position:0% +okay we're going to build an explanation + + + align:start position:0% +okay we're going to build an explanation +model G where G is the class of + + align:start position:0% +model G where G is the class of + + + align:start position:0% +model G where G is the class of +interpretable models so what's an + + align:start position:0% +interpretable models so what's an + + + align:start position:0% +interpretable models so what's an +interpretable model well they don't tell + + align:start position:0% +interpretable model well they don't tell + + + align:start position:0% +interpretable model well they don't tell +you but they say well examples might be + + align:start position:0% +you but they say well examples might be + + + align:start position:0% +you but they say well examples might be +linear models additive scores decision + + align:start position:0% +linear models additive scores decision + + + align:start position:0% +linear models additive scores decision +trees falling rule lists which + + align:start position:0% +trees falling rule lists which + + + align:start position:0% +trees falling rule lists which +see you later in the lecture and the + + align:start position:0% +see you later in the lecture and the + + + align:start position:0% +see you later in the lecture and the +domain of this is this input the + + align:start position:0% +domain of this is this input the + + + align:start position:0% +domain of this is this input the +simplified input data the binary + + align:start position:0% +simplified input data the binary + + + align:start position:0% +simplified input data the binary +variables in D prime dimensions and the + + align:start position:0% +variables in D prime dimensions and the + + + align:start position:0% +variables in D prime dimensions and the +model complexity is going to be some + + align:start position:0% +model complexity is going to be some + + + align:start position:0% +model complexity is going to be some +measure of the depths of the decision + + align:start position:0% +measure of the depths of the decision + + + align:start position:0% +measure of the depths of the decision +tree the number of nonzero weights and + + align:start position:0% +tree the number of nonzero weights and + + + align:start position:0% +tree the number of nonzero weights and +the logistic regression the number of + + align:start position:0% +the logistic regression the number of + + + align:start position:0% +the logistic regression the number of +clauses in a following rule list etc so + + align:start position:0% +clauses in a following rule list etc so + + + align:start position:0% +clauses in a following rule list etc so +it's some complexity measure and you + + align:start position:0% +it's some complexity measure and you + + + align:start position:0% +it's some complexity measure and you +want to minimize complexity so then they + + align:start position:0% +want to minimize complexity so then they + + + align:start position:0% +want to minimize complexity so then they +say alright the real model the the hairy + + align:start position:0% +say alright the real model the the hairy + + + align:start position:0% +say alright the real model the the hairy +complicated full Bohr model is F and + + align:start position:0% +complicated full Bohr model is F and + + + align:start position:0% +complicated full Bohr model is F and +that map's the original data space into + + align:start position:0% +that map's the original data space into + + + align:start position:0% +that map's the original data space into +some probability and for example for + + align:start position:0% +some probability and for example for + + + align:start position:0% +some probability and for example for +classification F is the probability that + + align:start position:0% +classification F is the probability that + + + align:start position:0% +classification F is the probability that +X belongs to a certain class and then + + align:start position:0% +X belongs to a certain class and then + + + align:start position:0% +X belongs to a certain class and then +they also need a proximity measure so + + align:start position:0% +they also need a proximity measure so + + + align:start position:0% +they also need a proximity measure so +they need to say we have to have a way + + align:start position:0% +they need to say we have to have a way + + + align:start position:0% +they need to say we have to have a way +of comparing two cases and saying how + + align:start position:0% +of comparing two cases and saying how + + + align:start position:0% +of comparing two cases and saying how +close are they to each other and the + + align:start position:0% +close are they to each other and the + + + align:start position:0% +close are they to each other and the +reason for that is because remember + + align:start position:0% +reason for that is because remember + + + align:start position:0% +reason for that is because remember +they're going to give you an explanation + + align:start position:0% +they're going to give you an explanation + + + align:start position:0% +they're going to give you an explanation +of a particular case and the most + + align:start position:0% +of a particular case and the most + + + align:start position:0% +of a particular case and the most +relevant things that will help with that + + align:start position:0% +relevant things that will help with that + + + align:start position:0% +relevant things that will help with that +explanation are the ones that are near + + align:start position:0% +explanation are the ones that are near + + + align:start position:0% +explanation are the ones that are near +it in this high dimensional input space + + align:start position:0% +it in this high dimensional input space + + + align:start position:0% +it in this high dimensional input space +okay so they then define their loss + + align:start position:0% +okay so they then define their loss + + + align:start position:0% +okay so they then define their loss +function based on the actual decision + + align:start position:0% +function based on the actual decision + + + align:start position:0% +function based on the actual decision +algorithm based on the simplified one + + align:start position:0% +algorithm based on the simplified one + + + align:start position:0% +algorithm based on the simplified one +and based on the proximity measure and + + align:start position:0% +and based on the proximity measure and + + + align:start position:0% +and based on the proximity measure and +they say well the best explanation is + + align:start position:0% +they say well the best explanation is + + + align:start position:0% +they say well the best explanation is +that G which minimizes this loss + + align:start position:0% +that G which minimizes this loss + + + align:start position:0% +that G which minimizes this loss +function plus the complexity of G pretty + + align:start position:0% +function plus the complexity of G pretty + + + align:start position:0% +function plus the complexity of G pretty +straightforward so that's our best best + + align:start position:0% +straightforward so that's our best best + + + align:start position:0% +straightforward so that's our best best +model + + align:start position:0% + + + + align:start position:0% + +now the clever idea here is to say + + align:start position:0% +now the clever idea here is to say + + + align:start position:0% +now the clever idea here is to say +instead of using all of the data that we + + align:start position:0% +instead of using all of the data that we + + + align:start position:0% +instead of using all of the data that we +started with what we're going to do is + + align:start position:0% +started with what we're going to do is + + + align:start position:0% +started with what we're going to do is +to sample the data so that we take more + + align:start position:0% +to sample the data so that we take more + + + align:start position:0% +to sample the data so that we take more +sample points near the point we're + + align:start position:0% +sample points near the point we're + + + align:start position:0% +sample points near the point we're +interested in exploit explaining we're + + align:start position:0% +interested in exploit explaining we're + + + align:start position:0% +interested in exploit explaining we're +going to sample in the simplified space + + align:start position:0% +going to sample in the simplified space + + + align:start position:0% +going to sample in the simplified space +that is explainable and then we'll build + + align:start position:0% +that is explainable and then we'll build + + + align:start position:0% +that is explainable and then we'll build +that G model the explanatory model from + + align:start position:0% +that G model the explanatory model from + + + align:start position:0% +that G model the explanatory model from +that sample of data where we wait by + + align:start position:0% +that sample of data where we wait by + + + align:start position:0% +that sample of data where we wait by +that proximity function so the things + + align:start position:0% +that proximity function so the things + + + align:start position:0% +that proximity function so the things +that are closer will have a larger + + align:start position:0% +that are closer will have a larger + + + align:start position:0% +that are closer will have a larger +influence on the model that we learn and + + align:start position:0% +influence on the model that we learn and + + + align:start position:0% +influence on the model that we learn and +then we recapture the sort of the + + align:start position:0% +then we recapture the sort of the + + + align:start position:0% +then we recapture the sort of the +closest point to this simplified + + align:start position:0% +closest point to this simplified + + + align:start position:0% +closest point to this simplified +representation we can calculate what its + + align:start position:0% +representation we can calculate what its + + + align:start position:0% +representation we can calculate what its +answer should be and that becomes the + + align:start position:0% +answer should be and that becomes the + + + align:start position:0% +answer should be and that becomes the +label for that point and so now we + + align:start position:0% +label for that point and so now we + + + align:start position:0% +label for that point and so now we +trained a simple model to predict the + + align:start position:0% +trained a simple model to predict the + + + align:start position:0% +trained a simple model to predict the +label that the complicated model would + + align:start position:0% +label that the complicated model would + + + align:start position:0% +label that the complicated model would +have predicted for the point that we've + + align:start position:0% +have predicted for the point that we've + + + align:start position:0% +have predicted for the point that we've +sampled okay yeah + + align:start position:0% + + + + align:start position:0% + +it's a distance function of some sort + + align:start position:0% +it's a distance function of some sort + + + align:start position:0% +it's a distance function of some sort +and I'll say more about it in a minute + + align:start position:0% +and I'll say more about it in a minute + + + align:start position:0% +and I'll say more about it in a minute +because that's one of the critiques of + + align:start position:0% +because that's one of the critiques of + + + align:start position:0% +because that's one of the critiques of +this particular method has to do with + + align:start position:0% +this particular method has to do with + + + align:start position:0% +this particular method has to do with +how do you choose that distance function + + align:start position:0% +how do you choose that distance function + + + align:start position:0% +how do you choose that distance function +but it's basically a similarity so + + align:start position:0% +but it's basically a similarity so + + + align:start position:0% +but it's basically a similarity so +here's a nice graphical explanation of + + align:start position:0% +here's a nice graphical explanation of + + + align:start position:0% +here's a nice graphical explanation of +what's going on + + align:start position:0% +what's going on + + + align:start position:0% +what's going on +suppose that the actual model the + + align:start position:0% +suppose that the actual model the + + + align:start position:0% +suppose that the actual model the +decision boundary is between the blue + + align:start position:0% +decision boundary is between the blue + + + align:start position:0% +decision boundary is between the blue +and the pink regions okay + + align:start position:0% +and the pink regions okay + + + align:start position:0% +and the pink regions okay +so it's this god-awful hairy complicated + + align:start position:0% +so it's this god-awful hairy complicated + + + align:start position:0% +so it's this god-awful hairy complicated +decision model and we're trying to + + align:start position:0% +decision model and we're trying to + + + align:start position:0% +decision model and we're trying to +explain why this big red plus wound up + + align:start position:0% +explain why this big red plus wound up + + + align:start position:0% +explain why this big red plus wound up +in the pink rather than in the blue so + + align:start position:0% +in the pink rather than in the blue so + + + align:start position:0% +in the pink rather than in the blue so +the approach that they take is to say + + align:start position:0% +the approach that they take is to say + + + align:start position:0% +the approach that they take is to say +well let's sample a bunch of points + + align:start position:0% +well let's sample a bunch of points + + + align:start position:0% +well let's sample a bunch of points +weighted by shortest distance so we do + + align:start position:0% +weighted by shortest distance so we do + + + align:start position:0% +weighted by shortest distance so we do +sample a few points out here but mostly + + align:start position:0% +sample a few points out here but mostly + + + align:start position:0% +sample a few points out here but mostly +we're sampling points near the point + + align:start position:0% +we're sampling points near the point + + + align:start position:0% +we're sampling points near the point +that we're interested in we then learn a + + align:start position:0% +that we're interested in we then learn a + + + align:start position:0% +that we're interested in we then learn a +linear boundary between the positive and + + align:start position:0% +linear boundary between the positive and + + + align:start position:0% +linear boundary between the positive and +the negative cases and that boundary is + + align:start position:0% +the negative cases and that boundary is + + + align:start position:0% +the negative cases and that boundary is +an approximation to the actual boundary + + align:start position:0% +an approximation to the actual boundary + + + align:start position:0% +an approximation to the actual boundary +in the more complicated decision model + + align:start position:0% +in the more complicated decision model + + + align:start position:0% +in the more complicated decision model +okay so now we can give an explanation + + align:start position:0% +okay so now we can give an explanation + + + align:start position:0% +okay so now we can give an explanation +just like you saw before which says well + + align:start position:0% +just like you saw before which says well + + + align:start position:0% +just like you saw before which says well +this is some D prime dimensional space + + align:start position:0% +this is some D prime dimensional space + + + align:start position:0% +this is some D prime dimensional space +and so which variables in that the D + + align:start position:0% +and so which variables in that the D + + + align:start position:0% +and so which variables in that the D +prime dimensional space are the ones + + align:start position:0% +prime dimensional space are the ones + + + align:start position:0% +prime dimensional space are the ones +that influence where you are on one side + + align:start position:0% +that influence where you are on one side + + + align:start position:0% +that influence where you are on one side +or another of this newly computed + + align:start position:0% +or another of this newly computed + + + align:start position:0% +or another of this newly computed +decision boundary and to and to what + + align:start position:0% +decision boundary and to and to what + + + align:start position:0% +decision boundary and to and to what +extent and that becomes the explanation + + align:start position:0% +extent and that becomes the explanation + + + align:start position:0% +extent and that becomes the explanation +okay nice idea + + align:start position:0% + + + + align:start position:0% + +so if you apply this to text + + align:start position:0% +so if you apply this to text + + + align:start position:0% +so if you apply this to text +classification yes well that's why I + + align:start position:0% +classification yes well that's why I + + + align:start position:0% +classification yes well that's why I +called the called just so story right + + align:start position:0% +called the called just so story right + + + align:start position:0% +called the called just so story right +should you believe it well the + + align:start position:0% +should you believe it well the + + + align:start position:0% +should you believe it well the +engineering disciplines have a very long + + align:start position:0% +engineering disciplines have a very long + + + align:start position:0% +engineering disciplines have a very long +history of approximating extremely + + align:start position:0% +history of approximating extremely + + + align:start position:0% +history of approximating extremely +complicated phenomena with linear models + + align:start position:0% +complicated phenomena with linear models + + + align:start position:0% +complicated phenomena with linear models +right I mean I'm I'm in a Department of + + align:start position:0% +right I mean I'm I'm in a Department of + + + align:start position:0% +right I mean I'm I'm in a Department of +Electrical Engineering and computer + + align:start position:0% +Electrical Engineering and computer + + + align:start position:0% +Electrical Engineering and computer +science and if I talked to my electrical + + align:start position:0% +science and if I talked to my electrical + + + align:start position:0% +science and if I talked to my electrical +engineering colleagues they know that + + align:start position:0% +engineering colleagues they know that + + + align:start position:0% +engineering colleagues they know that +the world is insanely complicated + + align:start position:0% +the world is insanely complicated + + + align:start position:0% +the world is insanely complicated +nevertheless most models in electrical + + align:start position:0% +nevertheless most models in electrical + + + align:start position:0% +nevertheless most models in electrical +engineering or linear models and they + + align:start position:0% +engineering or linear models and they + + + align:start position:0% +engineering or linear models and they +work well enough that people are able to + + align:start position:0% +work well enough that people are able to + + + align:start position:0% +work well enough that people are able to +build really complicated things and have + + align:start position:0% +build really complicated things and have + + + align:start position:0% +build really complicated things and have +them work so I that's not a proof that + + align:start position:0% +them work so I that's not a proof that + + + align:start position:0% +them work so I that's not a proof that +that's an argument by by history or + + align:start position:0% +that's an argument by by history or + + + align:start position:0% +that's an argument by by history or +something but it's true linear models + + align:start position:0% +something but it's true linear models + + + align:start position:0% +something but it's true linear models +are very powerful especially when you + + align:start position:0% +are very powerful especially when you + + + align:start position:0% +are very powerful especially when you +limit them to giving explanations that + + align:start position:0% +limit them to giving explanations that + + + align:start position:0% +limit them to giving explanations that +are local notice that this model is a + + align:start position:0% +are local notice that this model is a + + + align:start position:0% +are local notice that this model is a +very poor approximation to this decision + + align:start position:0% +very poor approximation to this decision + + + align:start position:0% +very poor approximation to this decision +boundary or this one right and so it + + align:start position:0% +boundary or this one right and so it + + + align:start position:0% +boundary or this one right and so it +only works to explain in the + + align:start position:0% +only works to explain in the + + + align:start position:0% +only works to explain in the +neighborhood of the particular example + + align:start position:0% +neighborhood of the particular example + + + align:start position:0% +neighborhood of the particular example +that I've chosen all right but it does + + align:start position:0% +that I've chosen all right but it does + + + align:start position:0% +that I've chosen all right but it does +work okay there + + align:start position:0% + + + + align:start position:0% + +in the middle of the red space then + + align:start position:0% +in the middle of the red space then + + + align:start position:0% +in the middle of the red space then +well they did so they sample all over + + align:start position:0% +well they did so they sample all over + + + align:start position:0% +well they did so they sample all over +the place but remember that that + + align:start position:0% +the place but remember that that + + + align:start position:0% +the place but remember that that +proximity function says that this one is + + align:start position:0% +proximity function says that this one is + + + align:start position:0% +proximity function says that this one is +less relevant to predicting that that + + align:start position:0% +less relevant to predicting that that + + + align:start position:0% +less relevant to predicting that that +decision boundary because it's far away + + align:start position:0% +decision boundary because it's far away + + + align:start position:0% +decision boundary because it's far away +from the point that I'm interested in so + + align:start position:0% +from the point that I'm interested in so + + + align:start position:0% +from the point that I'm interested in so +that's the magic + + align:start position:0% + + + + align:start position:0% + +well but but they they would I mean it's + + align:start position:0% +well but but they they would I mean it's + + + align:start position:0% +well but but they they would I mean it's +suppose they picked this point instead + + align:start position:0% +suppose they picked this point instead + + + align:start position:0% +suppose they picked this point instead +then they would sample around this point + + align:start position:0% +then they would sample around this point + + + align:start position:0% +then they would sample around this point +and and presumably they would find this + + align:start position:0% +and and presumably they would find this + + + align:start position:0% +and and presumably they would find this +decision boundary or this one or + + align:start position:0% +decision boundary or this one or + + + align:start position:0% +decision boundary or this one or +something like that and still still be + + align:start position:0% +something like that and still still be + + + align:start position:0% +something like that and still still be +able to come up with a coherent + + align:start position:0% +able to come up with a coherent + + + align:start position:0% +able to come up with a coherent +explanation okay so in the case of text + + align:start position:0% +explanation okay so in the case of text + + + align:start position:0% +explanation okay so in the case of text +you've seen this example already it's + + align:start position:0% +you've seen this example already it's + + + align:start position:0% +you've seen this example already it's +pretty simple they for their proximity + + align:start position:0% +pretty simple they for their proximity + + + align:start position:0% +pretty simple they for their proximity +function they use cosine distance so two + + align:start position:0% +function they use cosine distance so two + + + align:start position:0% +function they use cosine distance so two +bag of words model and they just + + align:start position:0% +bag of words model and they just + + + align:start position:0% +bag of words model and they just +calculate cosine distance between + + align:start position:0% +calculate cosine distance between + + + align:start position:0% +calculate cosine distance between +different examples by how much overlap + + align:start position:0% +different examples by how much overlap + + + align:start position:0% +different examples by how much overlap +there is between the words that they use + + align:start position:0% +there is between the words that they use + + + align:start position:0% +there is between the words that they use +and the frequency of words that they use + + align:start position:0% +and the frequency of words that they use + + + align:start position:0% +and the frequency of words that they use +and then they choose K with the number + + align:start position:0% +and then they choose K with the number + + + align:start position:0% +and then they choose K with the number +of words to show just as a preference so + + align:start position:0% +of words to show just as a preference so + + + align:start position:0% +of words to show just as a preference so +it's sort of a hyper parameter they say + + align:start position:0% +it's sort of a hyper parameter they say + + + align:start position:0% +it's sort of a hyper parameter they say +you know I'm interested in looking at + + align:start position:0% +you know I'm interested in looking at + + + align:start position:0% +you know I'm interested in looking at +the top five words or the top ten words + + align:start position:0% +the top five words or the top ten words + + + align:start position:0% +the top five words or the top ten words +that are either positively or negatively + + align:start position:0% +that are either positively or negatively + + + align:start position:0% +that are either positively or negatively +an influence on the decision but not the + + align:start position:0% +an influence on the decision but not the + + + align:start position:0% +an influence on the decision but not the +top 10,000 words because I don't know + + align:start position:0% +top 10,000 words because I don't know + + + align:start position:0% +top 10,000 words because I don't know +what to do with 10,000 words okay now + + align:start position:0% +what to do with 10,000 words okay now + + + align:start position:0% +what to do with 10,000 words okay now +what's interesting is you can also then + + align:start position:0% +what's interesting is you can also then + + + align:start position:0% +what's interesting is you can also then +apply the same idea to image + + align:start position:0% +apply the same idea to image + + + align:start position:0% +apply the same idea to image +interpretation so here's a dog playing a + + align:start position:0% +interpretation so here's a dog playing a + + + align:start position:0% +interpretation so here's a dog playing a +guitar and they say how do we interpret + + align:start position:0% +guitar and they say how do we interpret + + + align:start position:0% +guitar and they say how do we interpret +this and so this is one of these + + align:start position:0% +this and so this is one of these + + + align:start position:0% +this and so this is one of these +labeling tasks where you'd like to label + + align:start position:0% +labeling tasks where you'd like to label + + + align:start position:0% +labeling tasks where you'd like to label +this picture as a Labrador or maybe as + + align:start position:0% +this picture as a Labrador or maybe as + + + align:start position:0% +this picture as a Labrador or maybe as +an acoustic guitar but some some labels + + align:start position:0% +an acoustic guitar but some some labels + + + align:start position:0% +an acoustic guitar but some some labels +also decide that it's an electric guitar + + align:start position:0% +also decide that it's an electric guitar + + + align:start position:0% +also decide that it's an electric guitar +and so they say well what counts in + + align:start position:0% +and so they say well what counts in + + + align:start position:0% +and so they say well what counts in +favor of or against each of these and + + align:start position:0% +favor of or against each of these and + + + align:start position:0% +favor of or against each of these and +the approach they take is a relatively + + align:start position:0% +the approach they take is a relatively + + + align:start position:0% +the approach they take is a relatively +straightforward one they say let's + + align:start position:0% +straightforward one they say let's + + + align:start position:0% +straightforward one they say let's +define a super pixel as a region of + + align:start position:0% +define a super pixel as a region of + + + align:start position:0% +define a super pixel as a region of +pixels within it within an image that + + align:start position:0% +pixels within it within an image that + + + align:start position:0% +pixels within it within an image that +have roughly the same intensity so if + + align:start position:0% +have roughly the same intensity so if + + + align:start position:0% +have roughly the same intensity so if +you've ever used Photoshop the magic + + align:start position:0% +you've ever used Photoshop the magic + + + align:start position:0% +you've ever used Photoshop the magic +selection tool can be adjusted to say + + align:start position:0% +selection tool can be adjusted to say + + + align:start position:0% +selection tool can be adjusted to say +find the region around this point where + + align:start position:0% +find the region around this point where + + + align:start position:0% +find the region around this point where +all the intensities are within some + + align:start position:0% +all the intensities are within some + + + align:start position:0% +all the intensities are within some +Delta of the of the point that I've + + align:start position:0% +Delta of the of the point that I've + + + align:start position:0% +Delta of the of the point that I've +picked and so it will outline some + + align:start position:0% +picked and so it will outline some + + + align:start position:0% +picked and so it will outline some +region of the picture and what they do + + align:start position:0% +region of the picture and what they do + + + align:start position:0% +region of the picture and what they do +is they break up the entire image into + + align:start position:0% +is they break up the entire image into + + + align:start position:0% +is they break up the entire image into +these regions and then they treat those + + align:start position:0% +these regions and then they treat those + + + align:start position:0% +these regions and then they treat those +as if they were the words in the in the + + align:start position:0% +as if they were the words in the in the + + + align:start position:0% +as if they were the words in the in the +word style explanation okay so they say + + align:start position:0% +word style explanation okay so they say + + + align:start position:0% +word style explanation okay so they say +well this looks like an electric guitar + + align:start position:0% +well this looks like an electric guitar + + + align:start position:0% +well this looks like an electric guitar +to the algorithm and this looks like an + + align:start position:0% +to the algorithm and this looks like an + + + align:start position:0% +to the algorithm and this looks like an +acoustic guitar and this looks like a + + align:start position:0% +acoustic guitar and this looks like a + + + align:start position:0% +acoustic guitar and this looks like a +Labrador so some of that makes sense I + + align:start position:0% +Labrador so some of that makes sense I + + + align:start position:0% +Labrador so some of that makes sense I +mean you know that dog's face does kind + + align:start position:0% +mean you know that dog's face does kind + + + align:start position:0% +mean you know that dog's face does kind +of look like a lab this does look kind + + align:start position:0% +of look like a lab this does look kind + + + align:start position:0% +of look like a lab this does look kind +of like part of the body and part of the + + align:start position:0% +of like part of the body and part of the + + + align:start position:0% +of like part of the body and part of the +fret work of a guitar I have no idea + + align:start position:0% +fret work of a guitar I have no idea + + + align:start position:0% +fret work of a guitar I have no idea +what the stuff is or why this + + align:start position:0% +what the stuff is or why this + + + align:start position:0% +what the stuff is or why this +contributes to it being a dog but such + + align:start position:0% +contributes to it being a dog but such + + + align:start position:0% +contributes to it being a dog but such +as such as the nature of these models + + align:start position:0% +as such as the nature of these models + + + align:start position:0% +as such as the nature of these models +but at least it is telling you why it + + align:start position:0% +but at least it is telling you why it + + + align:start position:0% +but at least it is telling you why it +believes these various things so then + + align:start position:0% +believes these various things so then + + + align:start position:0% +believes these various things so then +the last thing they do is to say well + + align:start position:0% +the last thing they do is to say well + + + align:start position:0% +the last thing they do is to say well +okay that helps you understand the + + align:start position:0% +okay that helps you understand the + + + align:start position:0% +okay that helps you understand the +particular model but how do you convince + + align:start position:0% +particular model but how do you convince + + + align:start position:0% +particular model but how do you convince +yourself I mean a particular example + + align:start position:0% +yourself I mean a particular example + + + align:start position:0% +yourself I mean a particular example +where a model is applied to it but how + + align:start position:0% +where a model is applied to it but how + + + align:start position:0% +where a model is applied to it but how +do you convince yourself that the model + + align:start position:0% +do you convince yourself that the model + + + align:start position:0% +do you convince yourself that the model +itself is reasonable and so they say + + align:start position:0% +itself is reasonable and so they say + + + align:start position:0% +itself is reasonable and so they say +well the best technique we know is to + + align:start position:0% +well the best technique we know is to + + + align:start position:0% +well the best technique we know is to +show you a bunch of examples but we want + + align:start position:0% +show you a bunch of examples but we want + + + align:start position:0% +show you a bunch of examples but we want +those examples to kind of cover the + + align:start position:0% +those examples to kind of cover the + + + align:start position:0% +those examples to kind of cover the +gamut of places that you might be + + align:start position:0% +gamut of places that you might be + + + align:start position:0% +gamut of places that you might be +interested in and so they say let's + + align:start position:0% +interested in and so they say let's + + + align:start position:0% +interested in and so they say let's +create this matrix an explanation matrix + + align:start position:0% +create this matrix an explanation matrix + + + align:start position:0% +create this matrix an explanation matrix +where these are the cases and these are + + align:start position:0% +where these are the cases and these are + + + align:start position:0% +where these are the cases and these are +the various features you know the top + + align:start position:0% +the various features you know the top + + + align:start position:0% +the various features you know the top +words or the top pixel elements or + + align:start position:0% +words or the top pixel elements or + + + align:start position:0% +words or the top pixel elements or +something and then we'll fill in the + + align:start position:0% +something and then we'll fill in the + + + align:start position:0% +something and then we'll fill in the +element of the matrix that tells me how + + align:start position:0% +element of the matrix that tells me how + + + align:start position:0% +element of the matrix that tells me how +strongly the + + align:start position:0% +strongly the + + + align:start position:0% +strongly the +feature is correlated or anti-correlated + + align:start position:0% +feature is correlated or anti-correlated + + + align:start position:0% +feature is correlated or anti-correlated +with the classification for that model + + align:start position:0% +with the classification for that model + + + align:start position:0% +with the classification for that model +and then it becomes a kind of set + + align:start position:0% +and then it becomes a kind of set + + + align:start position:0% +and then it becomes a kind of set +covering issue find a set of models that + + align:start position:0% +covering issue find a set of models that + + + align:start position:0% +covering issue find a set of models that +gives me the best coverage of + + align:start position:0% +gives me the best coverage of + + + align:start position:0% +gives me the best coverage of +explanations across that set of features + + align:start position:0% +explanations across that set of features + + + align:start position:0% +explanations across that set of features +and then with that I can convince myself + + align:start position:0% +and then with that I can convince myself + + + align:start position:0% +and then with that I can convince myself +that the model is reasonable so they + + align:start position:0% +that the model is reasonable so they + + + align:start position:0% +that the model is reasonable so they +have this thing called the sub modular + + align:start position:0% +have this thing called the sub modular + + + align:start position:0% +have this thing called the sub modular +pick algorithm and you know probably if + + align:start position:0% +pick algorithm and you know probably if + + + align:start position:0% +pick algorithm and you know probably if +you're interested you should read the + + align:start position:0% +you're interested you should read the + + + align:start position:0% +you're interested you should read the +paper but what they're doing is this is + + align:start position:0% +paper but what they're doing is this is + + + align:start position:0% +paper but what they're doing is this is +essentially doing a kind of greedy + + align:start position:0% +essentially doing a kind of greedy + + + align:start position:0% +essentially doing a kind of greedy +search that says what feature should I + + align:start position:0% +search that says what feature should I + + + align:start position:0% +search that says what feature should I +add in order to get the best coverage in + + align:start position:0% +add in order to get the best coverage in + + + align:start position:0% +add in order to get the best coverage in +that space of features by documents and + + align:start position:0% + + + + align:start position:0% + +and then they did a bunch of experiments + + align:start position:0% +and then they did a bunch of experiments + + + align:start position:0% +and then they did a bunch of experiments +where they said okay let's compare the + + align:start position:0% +where they said okay let's compare the + + + align:start position:0% +where they said okay let's compare the +results of these explanations of these + + align:start position:0% +results of these explanations of these + + + align:start position:0% +results of these explanations of these +simplified models to two sentiment + + align:start position:0% +simplified models to two sentiment + + + align:start position:0% +simplified models to two sentiment +analysis tasks of two thousand instances + + align:start position:0% +analysis tasks of two thousand instances + + + align:start position:0% +analysis tasks of two thousand instances +each bag of words as features they + + align:start position:0% +each bag of words as features they + + + align:start position:0% +each bag of words as features they +compared it to decision trees logistic + + align:start position:0% +compared it to decision trees logistic + + + align:start position:0% +compared it to decision trees logistic +regression nearest neighbors SVM with a + + align:start position:0% +regression nearest neighbors SVM with a + + + align:start position:0% +regression nearest neighbors SVM with a +radial basis function kernel or random + + align:start position:0% +radial basis function kernel or random + + + align:start position:0% +radial basis function kernel or random +forests that use word to vacuum + + align:start position:0% +forests that use word to vacuum + + + align:start position:0% +forests that use word to vacuum +betting's + + align:start position:0% +betting's + + + align:start position:0% +betting's +highly non explainable with a thousand + + align:start position:0% +highly non explainable with a thousand + + + align:start position:0% +highly non explainable with a thousand +trees and k equal ten so they chose ten + + align:start position:0% +trees and k equal ten so they chose ten + + + align:start position:0% +trees and k equal ten so they chose ten +features to explain for each each of + + align:start position:0% +features to explain for each each of + + + align:start position:0% +features to explain for each each of +these models they then did a side + + align:start position:0% +these models they then did a side + + + align:start position:0% +these models they then did a side +calculation that said what are the ten + + align:start position:0% +calculation that said what are the ten + + + align:start position:0% +calculation that said what are the ten +most suggestive features for each case + + align:start position:0% +most suggestive features for each case + + + align:start position:0% +most suggestive features for each case +and then they said does that covering + + align:start position:0% +and then they said does that covering + + + align:start position:0% +and then they said does that covering +algorithm identify those features + + align:start position:0% +algorithm identify those features + + + align:start position:0% +algorithm identify those features +correctly and so what they show here is + + align:start position:0% +correctly and so what they show here is + + + align:start position:0% +correctly and so what they show here is +that they're their method line does + + align:start position:0% +that they're their method line does + + + align:start position:0% +that they're their method line does +better in every case than + + align:start position:0% +better in every case than + + + align:start position:0% +better in every case than +a random sampling that's not very + + align:start position:0% +a random sampling that's not very + + + align:start position:0% +a random sampling that's not very +surprising or a greedy sampling or a + + align:start position:0% +surprising or a greedy sampling or a + + + align:start position:0% +surprising or a greedy sampling or a +partisan sampling which I don't know the + + align:start position:0% +partisan sampling which I don't know the + + + align:start position:0% +partisan sampling which I don't know the +details of but in any case there's what + + align:start position:0% +details of but in any case there's what + + + align:start position:0% +details of but in any case there's what +this graph is showing is that of the + + align:start position:0% +this graph is showing is that of the + + + align:start position:0% +this graph is showing is that of the +features that they decided were + + align:start position:0% +features that they decided were + + + align:start position:0% +features that they decided were +important in each of these cases they're + + align:start position:0% +important in each of these cases they're + + + align:start position:0% +important in each of these cases they're +recovering so there recall is up around + + align:start position:0% +recovering so there recall is up around + + + align:start position:0% +recovering so there recall is up around +you know 90s 90 plus percent so in fact + + align:start position:0% +you know 90s 90 plus percent so in fact + + + align:start position:0% +you know 90s 90 plus percent so in fact +the algorithm is identifying the right + + align:start position:0% +the algorithm is identifying the right + + + align:start position:0% +the algorithm is identifying the right +cases to give you a broad coverage + + align:start position:0% +cases to give you a broad coverage + + + align:start position:0% +cases to give you a broad coverage +across all the important features that + + align:start position:0% +across all the important features that + + + align:start position:0% +across all the important features that +matter in classifying these cases they + + align:start position:0% +matter in classifying these cases they + + + align:start position:0% +matter in classifying these cases they +then also did a bunch of human + + align:start position:0% +then also did a bunch of human + + + align:start position:0% +then also did a bunch of human +experiments where they said okay we're + + align:start position:0% +experiments where they said okay we're + + + align:start position:0% +experiments where they said okay we're +going to ask users to choose which of + + align:start position:0% +going to ask users to choose which of + + + align:start position:0% +going to ask users to choose which of +two classifiers they think is going to + + align:start position:0% +two classifiers they think is going to + + + align:start position:0% +two classifiers they think is going to +generalize better so this is like the + + align:start position:0% +generalize better so this is like the + + + align:start position:0% +generalize better so this is like the +picture I showed you of the Christianity + + align:start position:0% +picture I showed you of the Christianity + + + align:start position:0% +picture I showed you of the Christianity +versus atheism algorithm where + + align:start position:0% +versus atheism algorithm where + + + align:start position:0% +versus atheism algorithm where +presumably if you were a Mechanical Turk + + align:start position:0% +presumably if you were a Mechanical Turk + + + align:start position:0% +presumably if you were a Mechanical Turk +er and somebody showed you an algorithm + + align:start position:0% +er and somebody showed you an algorithm + + + align:start position:0% +er and somebody showed you an algorithm +that has very high accuracy but that + + align:start position:0% +that has very high accuracy but that + + + align:start position:0% +that has very high accuracy but that +depends on things like finding the word + + align:start position:0% +depends on things like finding the word + + + align:start position:0% +depends on things like finding the word +and NTP in a classifier for atheism + + align:start position:0% +and NTP in a classifier for atheism + + + align:start position:0% +and NTP in a classifier for atheism +versus Christianity you would say well + + align:start position:0% +versus Christianity you would say well + + + align:start position:0% +versus Christianity you would say well +maybe that algorithm isn't going to + + align:start position:0% +maybe that algorithm isn't going to + + + align:start position:0% +maybe that algorithm isn't going to +generalize very well because it's + + align:start position:0% +generalize very well because it's + + + align:start position:0% +generalize very well because it's +depending on something random that may + + align:start position:0% +depending on something random that may + + + align:start position:0% +depending on something random that may +be correlated with this particular + + align:start position:0% +be correlated with this particular + + + align:start position:0% +be correlated with this particular +dataset but if I try it on a different + + align:start position:0% +dataset but if I try it on a different + + + align:start position:0% +dataset but if I try it on a different +data set it's unlikely to work so that + + align:start position:0% +data set it's unlikely to work so that + + + align:start position:0% +data set it's unlikely to work so that +was one of the tasks and then they asked + + align:start position:0% +was one of the tasks and then they asked + + + align:start position:0% +was one of the tasks and then they asked +them to identify features like that that + + align:start position:0% +them to identify features like that that + + + align:start position:0% +them to identify features like that that +looked bad they then ran this + + align:start position:0% +looked bad they then ran this + + + align:start position:0% +looked bad they then ran this +Christianity versus atheism test and had + + align:start position:0% +Christianity versus atheism test and had + + + align:start position:0% +Christianity versus atheism test and had +a separate test set of about 800 + + align:start position:0% +a separate test set of about 800 + + + align:start position:0% +a separate test set of about 800 +additional webpages from this website + + align:start position:0% +additional webpages from this website + + + align:start position:0% +additional webpages from this website +they the underlying model was a support + + align:start position:0% +they the underlying model was a support + + + align:start position:0% +they the underlying model was a support +vector machine with RBF kernels trained + + align:start position:0% +vector machine with RBF kernels trained + + + align:start position:0% +vector machine with RBF kernels trained +on the 20 News group data I don't know + + align:start position:0% +on the 20 News group data I don't know + + + align:start position:0% +on the 20 News group data I don't know +if you know that + + align:start position:0% +if you know that + + + align:start position:0% +if you know that +dataset but it's it's a well known + + align:start position:0% +dataset but it's it's a well known + + + align:start position:0% +dataset but it's it's a well known +publicly available dataset they got a + + align:start position:0% +publicly available dataset they got a + + + align:start position:0% +publicly available dataset they got a +hundred Mechanical Turkish and they said + + align:start position:0% +hundred Mechanical Turkish and they said + + + align:start position:0% +hundred Mechanical Turkish and they said +okay we're gonna present each of them + + align:start position:0% +okay we're gonna present each of them + + + align:start position:0% +okay we're gonna present each of them +six documents and six features per + + align:start position:0% +six documents and six features per + + + align:start position:0% +six documents and six features per +document in order to ask them to make + + align:start position:0% +document in order to ask them to make + + + align:start position:0% +document in order to ask them to make +this and then they did an auxiliary + + align:start position:0% +this and then they did an auxiliary + + + align:start position:0% +this and then they did an auxiliary +experiment in which they said if you see + + align:start position:0% +experiment in which they said if you see + + + align:start position:0% +experiment in which they said if you see +words that are no good in this + + align:start position:0% +words that are no good in this + + + align:start position:0% +words that are no good in this +experiment just strike them out and that + + align:start position:0% +experiment just strike them out and that + + + align:start position:0% +experiment just strike them out and that +will tell us which of the features were + + align:start position:0% +will tell us which of the features were + + + align:start position:0% +will tell us which of the features were +bad in in this in this method and what + + align:start position:0% +bad in in this in this method and what + + + align:start position:0% +bad in in this in this method and what +they found was that the human subjects + + align:start position:0% +they found was that the human subjects + + + align:start position:0% +they found was that the human subjects +choosing between two classifiers were + + align:start position:0% +choosing between two classifiers were + + + align:start position:0% +choosing between two classifiers were +pretty good at figuring out which was + + align:start position:0% +pretty good at figuring out which was + + + align:start position:0% +pretty good at figuring out which was +the better classifier now this is better + + align:start position:0% +the better classifier now this is better + + + align:start position:0% +the better classifier now this is better +by their their judgment and so they said + + align:start position:0% +by their their judgment and so they said + + + align:start position:0% +by their their judgment and so they said +okay the the sub-module or pick + + align:start position:0% +okay the the sub-module or pick + + + align:start position:0% +okay the the sub-module or pick +algorithm which is the one that I didn't + + align:start position:0% +algorithm which is the one that I didn't + + + align:start position:0% +algorithm which is the one that I didn't +describe in detail but it's this set + + align:start position:0% +describe in detail but it's this set + + + align:start position:0% +describe in detail but it's this set +covering algorithm gives you better + + align:start position:0% +covering algorithm gives you better + + + align:start position:0% +covering algorithm gives you better +results than a random pick algorithm + + align:start position:0% +results than a random pick algorithm + + + align:start position:0% +results than a random pick algorithm +that just says pick random features + + align:start position:0% +that just says pick random features + + + align:start position:0% +that just says pick random features +again not totally surprising so and the + + align:start position:0% +again not totally surprising so and the + + + align:start position:0% +again not totally surprising so and the +other thing that's interesting is if you + + align:start position:0% +other thing that's interesting is if you + + + align:start position:0% +other thing that's interesting is if you +do the feature engineering experiment it + + align:start position:0% +do the feature engineering experiment it + + + align:start position:0% +do the feature engineering experiment it +shows that as the Turkish interacted + + align:start position:0% +shows that as the Turkish interacted + + + align:start position:0% +shows that as the Turkish interacted +with the system the system became better + + align:start position:0% +with the system the system became better + + + align:start position:0% +with the system the system became better +so they started off with real-world + + align:start position:0% +so they started off with real-world + + + align:start position:0% +so they started off with real-world +accuracy of just under 60 percent and + + align:start position:0% +accuracy of just under 60 percent and + + + align:start position:0% +accuracy of just under 60 percent and +using the better of their algorithms + + align:start position:0% +using the better of their algorithms + + + align:start position:0% +using the better of their algorithms +they reached about seventy five percent + + align:start position:0% +they reached about seventy five percent + + + align:start position:0% +they reached about seventy five percent +after three rounds of interaction so the + + align:start position:0% +after three rounds of interaction so the + + + align:start position:0% +after three rounds of interaction so the +users could say I don't like this + + align:start position:0% +users could say I don't like this + + + align:start position:0% +users could say I don't like this +feature and then the system would give + + align:start position:0% +feature and then the system would give + + + align:start position:0% +feature and then the system would give +them better features now they tried a + + align:start position:0% +them better features now they tried a + + + align:start position:0% +them better features now they tried a +similar thing with images and so they + + align:start position:0% +similar thing with images and so they + + + align:start position:0% +similar thing with images and so they +this one is a little funny + + align:start position:0% +this one is a little funny + + + align:start position:0% +this one is a little funny +so they trained a deliberately lousy + + align:start position:0% +so they trained a deliberately lousy + + + align:start position:0% +so they trained a deliberately lousy +classifier to classify between + + align:start position:0% +classifier to classify between + + + align:start position:0% +classifier to classify between +wolves and huskies right this is a + + align:start position:0% +wolves and huskies right this is a + + + align:start position:0% +wolves and huskies right this is a +famous example also it turns out that + + align:start position:0% +famous example also it turns out that + + + align:start position:0% +famous example also it turns out that +that Huskies live in Alaska and so and + + align:start position:0% +that Huskies live in Alaska and so and + + + align:start position:0% +that Huskies live in Alaska and so and +wolves I guess some wolves do but most + + align:start position:0% +wolves I guess some wolves do but most + + + align:start position:0% +wolves I guess some wolves do but most +wolves don't and so the data set on + + align:start position:0% +wolves don't and so the data set on + + + align:start position:0% +wolves don't and so the data set on +which that are written which was used in + + align:start position:0% +which that are written which was used in + + + align:start position:0% +which that are written which was used in +that original problem formulation there + + align:start position:0% +that original problem formulation there + + + align:start position:0% +that original problem formulation there +was an extremely accurate classifier + + align:start position:0% +was an extremely accurate classifier + + + align:start position:0% +was an extremely accurate classifier +that was trained and when they went to + + align:start position:0% +that was trained and when they went to + + + align:start position:0% +that was trained and when they went to +look to see what it had learned + + align:start position:0% +look to see what it had learned + + + align:start position:0% +look to see what it had learned +basically it had learned to look for + + align:start position:0% +basically it had learned to look for + + + align:start position:0% +basically it had learned to look for +snow and if it saw snow in the picture + + align:start position:0% +snow and if it saw snow in the picture + + + align:start position:0% +snow and if it saw snow in the picture +it said it's a husky and if it didn't + + align:start position:0% +it said it's a husky and if it didn't + + + align:start position:0% +it said it's a husky and if it didn't +see snow in the picture it said it's a + + align:start position:0% +see snow in the picture it said it's a + + + align:start position:0% +see snow in the picture it said it's a +wolf so that turns out to be pretty + + align:start position:0% +wolf so that turns out to be pretty + + + align:start position:0% +wolf so that turns out to be pretty +accurate for the sample that they had + + align:start position:0% +accurate for the sample that they had + + + align:start position:0% +accurate for the sample that they had +but of course it's not a very + + align:start position:0% +but of course it's not a very + + + align:start position:0% +but of course it's not a very +sophisticated classification algorithm + + align:start position:0% +sophisticated classification algorithm + + + align:start position:0% +sophisticated classification algorithm +because it's possible to put a wolf in a + + align:start position:0% +because it's possible to put a wolf in a + + + align:start position:0% +because it's possible to put a wolf in a +snowy picture and it's possible to have + + align:start position:0% +snowy picture and it's possible to have + + + align:start position:0% +snowy picture and it's possible to have +your husky indoors with no snow and then + + align:start position:0% +your husky indoors with no snow and then + + + align:start position:0% +your husky indoors with no snow and then +you're just missing the boat on this + + align:start position:0% +you're just missing the boat on this + + + align:start position:0% +you're just missing the boat on this +classification so these guys built a + + align:start position:0% +classification so these guys built a + + + align:start position:0% +classification so these guys built a +particularly bad classifier by having + + align:start position:0% +particularly bad classifier by having + + + align:start position:0% +particularly bad classifier by having +all wolves in the training set had snow + + align:start position:0% +all wolves in the training set had snow + + + align:start position:0% +all wolves in the training set had snow +in the picture and none of the Huskies + + align:start position:0% +in the picture and none of the Huskies + + + align:start position:0% +in the picture and none of the Huskies +did okay and then they presented cases + + align:start position:0% +did okay and then they presented cases + + + align:start position:0% +did okay and then they presented cases +to graduate students like you guys with + + align:start position:0% +to graduate students like you guys with + + + align:start position:0% +to graduate students like you guys with +math machine learning backgrounds ten + + align:start position:0% +math machine learning backgrounds ten + + + align:start position:0% +math machine learning backgrounds ten +balanced test predictions but they put + + align:start position:0% +balanced test predictions but they put + + + align:start position:0% +balanced test predictions but they put +one ringer in each category so they put + + align:start position:0% +one ringer in each category so they put + + + align:start position:0% +one ringer in each category so they put +in one husky in snow and one wolf who + + align:start position:0% +in one husky in snow and one wolf who + + + align:start position:0% +in one husky in snow and one wolf who +was not in snow and the comparison was + + align:start position:0% +was not in snow and the comparison was + + + align:start position:0% +was not in snow and the comparison was +between pre and post experiment trust + + align:start position:0% +between pre and post experiment trust + + + align:start position:0% +between pre and post experiment trust +and understanding and so before the + + align:start position:0% +and understanding and so before the + + + align:start position:0% +and understanding and so before the +experiment they said that 10 of the 27 + + align:start position:0% +experiment they said that 10 of the 27 + + + align:start position:0% +experiment they said that 10 of the 27 +students said they trusted the bad mom + + align:start position:0% +students said they trusted the bad mom + + + align:start position:0% +students said they trusted the bad mom +this bad model that they trained and + + align:start position:0% +this bad model that they trained and + + + align:start position:0% +this bad model that they trained and +afterwards only 3 out of 27 trusted it + + align:start position:0% +afterwards only 3 out of 27 trusted it + + + align:start position:0% +afterwards only 3 out of 27 trusted it +so this is a kind of sociological + + align:start position:0% +so this is a kind of sociological + + + align:start position:0% +so this is a kind of sociological +experiment that says yes we can actually + + align:start position:0% +experiment that says yes we can actually + + + align:start position:0% +experiment that says yes we can actually +change people's minds about whether + + align:start position:0% +change people's minds about whether + + + align:start position:0% +change people's minds about whether +remodel is a good or a bad one + + align:start position:0% +remodel is a good or a bad one + + + align:start position:0% +remodel is a good or a bad one +an experiment before only 12 out of 27 + + align:start position:0% +an experiment before only 12 out of 27 + + + align:start position:0% +an experiment before only 12 out of 27 +students mentioned snow as a potential + + align:start position:0% +students mentioned snow as a potential + + + align:start position:0% +students mentioned snow as a potential +feature in this classifier whereas + + align:start position:0% +feature in this classifier whereas + + + align:start position:0% +feature in this classifier whereas +afterwards almost everybody did so again + + align:start position:0% +afterwards almost everybody did so again + + + align:start position:0% +afterwards almost everybody did so again +this tells you that that the method is + + align:start position:0% +this tells you that that the method is + + + align:start position:0% +this tells you that that the method is +providing some useful information now + + align:start position:0% +providing some useful information now + + + align:start position:0% +providing some useful information now +this paper set off a lot of work + + align:start position:0% +this paper set off a lot of work + + + align:start position:0% +this paper set off a lot of work +including a lot of critiques of the work + + align:start position:0% +including a lot of critiques of the work + + + align:start position:0% +including a lot of critiques of the work +and so this is one particular one from + + align:start position:0% +and so this is one particular one from + + + align:start position:0% +and so this is one particular one from +just a few months ago the end of + + align:start position:0% +just a few months ago the end of + + + align:start position:0% +just a few months ago the end of +December and what these guys say is that + + align:start position:0% +December and what these guys say is that + + + align:start position:0% +December and what these guys say is that +that distance function which includes a + + align:start position:0% +that distance function which includes a + + + align:start position:0% +that distance function which includes a +Sigma which is sort of the scale of + + align:start position:0% +Sigma which is sort of the scale of + + + align:start position:0% +Sigma which is sort of the scale of +distance that you're willing to go is + + align:start position:0% +distance that you're willing to go is + + + align:start position:0% +distance that you're willing to go is +pretty arbitrary in the experiments that + + align:start position:0% +pretty arbitrary in the experiments that + + + align:start position:0% +pretty arbitrary in the experiments that +the original authors did they set that + + align:start position:0% +the original authors did they set that + + + align:start position:0% +the original authors did they set that +distance to 75 percent of the square + + align:start position:0% +distance to 75 percent of the square + + + align:start position:0% +distance to 75 percent of the square +root of the dimensionality of the data + + align:start position:0% +root of the dimensionality of the data + + + align:start position:0% +root of the dimensionality of the data +set and you know okay I mean that's a + + align:start position:0% +set and you know okay I mean that's a + + + align:start position:0% +set and you know okay I mean that's a +number but it's not obvious that that's + + align:start position:0% +number but it's not obvious that that's + + + align:start position:0% +number but it's not obvious that that's +the best number or the right number and + + align:start position:0% +the best number or the right number and + + + align:start position:0% +the best number or the right number and +so these guys argue that it's important + + align:start position:0% +so these guys argue that it's important + + + align:start position:0% +so these guys argue that it's important +to tune the size of the neighborhood + + align:start position:0% +to tune the size of the neighborhood + + + align:start position:0% +to tune the size of the neighborhood +according to how far Z the point that + + align:start position:0% +according to how far Z the point that + + + align:start position:0% +according to how far Z the point that +you're trying to explain is from a + + align:start position:0% +you're trying to explain is from a + + + align:start position:0% +you're trying to explain is from a +boundary so if it's close to the + + align:start position:0% +boundary so if it's close to the + + + align:start position:0% +boundary so if it's close to the +boundary then you ought to take a + + align:start position:0% +boundary then you ought to take a + + + align:start position:0% +boundary then you ought to take a +smaller region for your proximity + + align:start position:0% +smaller region for your proximity + + + align:start position:0% +smaller region for your proximity +measure and if it's far from the + + align:start position:0% +measure and if it's far from the + + + align:start position:0% +measure and if it's far from the +boundary this addresses the question you + + align:start position:0% +boundary this addresses the question you + + + align:start position:0% +boundary this addresses the question you +guys were asking about what happens if + + align:start position:0% +guys were asking about what happens if + + + align:start position:0% +guys were asking about what happens if +you pick a point in the middle and so + + align:start position:0% +you pick a point in the middle and so + + + align:start position:0% +you pick a point in the middle and so +they show some nice examples of places + + align:start position:0% +they show some nice examples of places + + + align:start position:0% +they show some nice examples of places +where for for instance if you compare + + align:start position:0% +where for for instance if you compare + + + align:start position:0% +where for for instance if you compare +this explaining this Green Point you get + + align:start position:0% +this explaining this Green Point you get + + + align:start position:0% +this explaining this Green Point you get +a nice green line that follows the local + + align:start position:0% +a nice green line that follows the local + + + align:start position:0% +a nice green line that follows the local +boundary but explaining the Blue Point + + align:start position:0% +boundary but explaining the Blue Point + + + align:start position:0% +boundary but explaining the Blue Point +which is close to a corner of the the + + align:start position:0% +which is close to a corner of the the + + + align:start position:0% +which is close to a corner of the the +actual decision boundary you get a line + + align:start position:0% +actual decision boundary you get a line + + + align:start position:0% +actual decision boundary you get a line +that's not very different from the green + + align:start position:0% +that's not very different from the green + + + align:start position:0% +that's not very different from the green +one and similarly for the red point and + + align:start position:0% +one and similarly for the red point and + + + align:start position:0% +one and similarly for the red point and +so they say well we really need to work + + align:start position:0% +so they say well we really need to work + + + align:start position:0% +so they say well we really need to work +on + + align:start position:0% +on + + + align:start position:0% +on +distance function and so they come up + + align:start position:0% +distance function and so they come up + + + align:start position:0% +distance function and so they come up +with a method that they call leaf äj-- + + align:start position:0% +with a method that they call leaf äj-- + + + align:start position:0% +with a method that they call leaf äj-- +which basically says remember what lime + + align:start position:0% +which basically says remember what lime + + + align:start position:0% +which basically says remember what lime +did is it sampled nonexistent cases + + align:start position:0% +did is it sampled nonexistent cases + + + align:start position:0% +did is it sampled nonexistent cases +simplified non-existent cases but here + + align:start position:0% +simplified non-existent cases but here + + + align:start position:0% +simplified non-existent cases but here +they're gonna sample existing cases so + + align:start position:0% +they're gonna sample existing cases so + + + align:start position:0% +they're gonna sample existing cases so +they're going to learn from the + + align:start position:0% +they're going to learn from the + + + align:start position:0% +they're going to learn from the +trainings the original training set but + + align:start position:0% +trainings the original training set but + + + align:start position:0% +trainings the original training set but +they're going to sample it by proximity + + align:start position:0% +they're going to sample it by proximity + + + align:start position:0% +they're going to sample it by proximity +to the the example that they're trying + + align:start position:0% +to the the example that they're trying + + + align:start position:0% +to the the example that they're trying +to explain and they argue that this is a + + align:start position:0% +to explain and they argue that this is a + + + align:start position:0% +to explain and they argue that this is a +good idea because for example in law the + + align:start position:0% +good idea because for example in law the + + + align:start position:0% +good idea because for example in law the +notion of precedent is that you get to + + align:start position:0% +notion of precedent is that you get to + + + align:start position:0% +notion of precedent is that you get to +argue that this case is very similar to + + align:start position:0% +argue that this case is very similar to + + + align:start position:0% +argue that this case is very similar to +some previously decided case and + + align:start position:0% +some previously decided case and + + + align:start position:0% +some previously decided case and +therefore it should be decided the same + + align:start position:0% +therefore it should be decided the same + + + align:start position:0% +therefore it should be decided the same +way + + align:start position:0% +way + + + align:start position:0% +way +I mean Supreme Court arguments are + + align:start position:0% +I mean Supreme Court arguments are + + + align:start position:0% +I mean Supreme Court arguments are +always all about that lower court + + align:start position:0% +always all about that lower court + + + align:start position:0% +always all about that lower court +arguments are sometimes more driven by + + align:start position:0% +arguments are sometimes more driven by + + + align:start position:0% +arguments are sometimes more driven by +what the law actually says but case law + + align:start position:0% +what the law actually says but case law + + + align:start position:0% +what the law actually says but case law +has been well established in British law + + align:start position:0% +has been well established in British law + + + align:start position:0% +has been well established in British law +and then by by inheritance in American + + align:start position:0% +and then by by inheritance in American + + + align:start position:0% +and then by by inheritance in American +law for many many centuries so they say + + align:start position:0% +law for many many centuries so they say + + + align:start position:0% +law for many many centuries so they say +well case based reasoning normally + + align:start position:0% +well case based reasoning normally + + + align:start position:0% +well case based reasoning normally +involves retrieving a similar case + + align:start position:0% +involves retrieving a similar case + + + align:start position:0% +involves retrieving a similar case +adapting it and then learning at that as + + align:start position:0% +adapting it and then learning at that as + + + align:start position:0% +adapting it and then learning at that as +a new precedent and they also argue for + + align:start position:0% +a new precedent and they also argue for + + + align:start position:0% +a new precedent and they also argue for +contrastive justification which is not + + align:start position:0% +contrastive justification which is not + + + align:start position:0% +contrastive justification which is not +only why did you choose X but why did + + align:start position:0% +only why did you choose X but why did + + + align:start position:0% +only why did you choose X but why did +you choose X rather than Y as giving a + + align:start position:0% +you choose X rather than Y as giving a + + + align:start position:0% +you choose X rather than Y as giving a +more satisfying and a more insightful + + align:start position:0% +more satisfying and a more insightful + + + align:start position:0% +more satisfying and a more insightful +explanation of how some model is working + + align:start position:0% +explanation of how some model is working + + + align:start position:0% +explanation of how some model is working +so they say okay similar set up F solves + + align:start position:0% +so they say okay similar set up F solves + + + align:start position:0% +so they say okay similar set up F solves +the classification problem where X is + + align:start position:0% +the classification problem where X is + + + align:start position:0% +the classification problem where X is +the data and Y is some binary classifier + + align:start position:0% +the data and Y is some binary classifier + + + align:start position:0% +the data and Y is some binary classifier +you know 0 or 0 1 if you like the + + align:start position:0% +you know 0 or 0 1 if you like the + + + align:start position:0% +you know 0 or 0 1 if you like the +training set is a bunch of X's y sub + + align:start position:0% +training set is a bunch of X's y sub + + + align:start position:0% +training set is a bunch of X's y sub +true is the actual answer and Y + + align:start position:0% +true is the actual answer and Y + + + align:start position:0% +true is the actual answer and Y +predicted is what F predicts on that on + + align:start position:0% +predicted is what F predicts on that on + + + align:start position:0% +predicted is what F predicts on that on +that X and to explain f of Z equals some + + align:start position:0% +that X and to explain f of Z equals some + + + align:start position:0% +that X and to explain f of Z equals some +pretty + + align:start position:0% +pretty + + + align:start position:0% +pretty +or outcome you can define the allies of + + align:start position:0% +or outcome you can define the allies of + + + align:start position:0% +or outcome you can define the allies of +a case as ones that come up with the + + align:start position:0% +a case as ones that come up with the + + + align:start position:0% +a case as ones that come up with the +same answer and you can define the + + align:start position:0% +same answer and you can define the + + + align:start position:0% +same answer and you can define the +enemies as one that ones that come up + + align:start position:0% +enemies as one that ones that come up + + + align:start position:0% +enemies as one that ones that come up +with a different answer right so now + + align:start position:0% +with a different answer right so now + + + align:start position:0% +with a different answer right so now +you're gonna sample both the Allies and + + align:start position:0% +you're gonna sample both the Allies and + + + align:start position:0% +you're gonna sample both the Allies and +the enemies according to a new distance + + align:start position:0% +the enemies according to a new distance + + + align:start position:0% +the enemies according to a new distance +function and the intuition they had is + + align:start position:0% +function and the intuition they had is + + + align:start position:0% +function and the intuition they had is +that the reason that they're that the + + align:start position:0% +that the reason that they're that the + + + align:start position:0% +that the reason that they're that the +distance function in the original line + + align:start position:0% +distance function in the original line + + + align:start position:0% +distance function in the original line +work wasn't working very well is because + + align:start position:0% +work wasn't working very well is because + + + align:start position:0% +work wasn't working very well is because +it was a spherical distance function in + + align:start position:0% +it was a spherical distance function in + + + align:start position:0% +it was a spherical distance function in +n-dimensional space and so they're gonna + + align:start position:0% +n-dimensional space and so they're gonna + + + align:start position:0% +n-dimensional space and so they're gonna +bias it by saying that the distance this + + align:start position:0% +bias it by saying that the distance this + + + align:start position:0% +bias it by saying that the distance this +B is going to be some combination of the + + align:start position:0% +B is going to be some combination of the + + + align:start position:0% +B is going to be some combination of the +difference in in the linear predictions + + align:start position:0% +difference in in the linear predictions + + + align:start position:0% +difference in in the linear predictions +plus the difference in the two points + + align:start position:0% +plus the difference in the two points + + + align:start position:0% +plus the difference in the two points +and so the contour lines of the first + + align:start position:0% +and so the contour lines of the first + + + align:start position:0% +and so the contour lines of the first +term are these circular contour lines + + align:start position:0% +term are these circular contour lines + + + align:start position:0% +term are these circular contour lines +this is what lime was doing the contour + + align:start position:0% +this is what lime was doing the contour + + + align:start position:0% +this is what lime was doing the contour +lines of the second term are these + + align:start position:0% +lines of the second term are these + + + align:start position:0% +lines of the second term are these +linear gradients and they add them to + + align:start position:0% +linear gradients and they add them to + + + align:start position:0% +linear gradients and they add them to +get sort of oval shaped things and this + + align:start position:0% +get sort of oval shaped things and this + + + align:start position:0% +get sort of oval shaped things and this +is what gives you that desired feature + + align:start position:0% +is what gives you that desired feature + + + align:start position:0% +is what gives you that desired feature +of being more sensitive to how close + + align:start position:0% +of being more sensitive to how close + + + align:start position:0% +of being more sensitive to how close +this point is to the decision boundary + + align:start position:0% +this point is to the decision boundary + + + align:start position:0% +this point is to the decision boundary +okay again there are a lot of relatively + + align:start position:0% +okay again there are a lot of relatively + + + align:start position:0% +okay again there are a lot of relatively +hairy details which I'm going to elide + + align:start position:0% +hairy details which I'm going to elide + + + align:start position:0% +hairy details which I'm going to elide +in the in the class today but they're + + align:start position:0% +in the in the class today but they're + + + align:start position:0% +in the in the class today but they're +they're definitely in the paper so they + + align:start position:0% +they're definitely in the paper so they + + + align:start position:0% +they're definitely in the paper so they +also did a user study on some very + + align:start position:0% +also did a user study on some very + + + align:start position:0% +also did a user study on some very +simple prediction models so this was how + + align:start position:0% +simple prediction models so this was how + + + align:start position:0% +simple prediction models so this was how +much is your house worth based on things + + align:start position:0% +much is your house worth based on things + + + align:start position:0% +much is your house worth based on things +like how how big is it and what year was + + align:start position:0% +like how how big is it and what year was + + + align:start position:0% +like how how big is it and what year was +it built built in and what's some + + align:start position:0% +it built built in and what's some + + + align:start position:0% +it built built in and what's some +subjective quality judgment of it and so + + align:start position:0% +subjective quality judgment of it and so + + + align:start position:0% +subjective quality judgment of it and so +what they show is that you can find the + + align:start position:0% +what they show is that you can find the + + + align:start position:0% +what they show is that you can find the +examples that are the the allies and the + + align:start position:0% +examples that are the the allies and the + + + align:start position:0% +examples that are the the allies and the +enemies of this house in + + align:start position:0% +enemies of this house in + + + align:start position:0% +enemies of this house in +order to do the prediction so then they + + align:start position:0% +order to do the prediction so then they + + + align:start position:0% +order to do the prediction so then they +applied their algorithm and if it works + + align:start position:0% +applied their algorithm and if it works + + + align:start position:0% +applied their algorithm and if it works +it gives you better answers I'll have to + + align:start position:0% +it gives you better answers I'll have to + + + align:start position:0% +it gives you better answers I'll have to +go find that slide somewhere all right + + align:start position:0% +go find that slide somewhere all right + + + align:start position:0% +go find that slide somewhere all right +so that's that's all I'm gonna say about + + align:start position:0% +so that's that's all I'm gonna say about + + + align:start position:0% +so that's that's all I'm gonna say about +about this this idea of using simplified + + align:start position:0% +about this this idea of using simplified + + + align:start position:0% +about this this idea of using simplified +models in the local neighborhood of + + align:start position:0% +models in the local neighborhood of + + + align:start position:0% +models in the local neighborhood of +individual cases in order to explain + + align:start position:0% +individual cases in order to explain + + + align:start position:0% +individual cases in order to explain +something I wanted to talk about two + + align:start position:0% +something I wanted to talk about two + + + align:start position:0% +something I wanted to talk about two +other topics so this was a paper by some + + align:start position:0% +other topics so this was a paper by some + + + align:start position:0% +other topics so this was a paper by some +of my students recently in which they're + + align:start position:0% +of my students recently in which they're + + + align:start position:0% +of my students recently in which they're +looking at medical images and trying to + + align:start position:0% +looking at medical images and trying to + + + align:start position:0% +looking at medical images and trying to +generate radiology reports from those + + align:start position:0% +generate radiology reports from those + + + align:start position:0% +generate radiology reports from those +medical images right I mean you know + + align:start position:0% +medical images right I mean you know + + + align:start position:0% +medical images right I mean you know +machine learning can solve all problems + + align:start position:0% +machine learning can solve all problems + + + align:start position:0% +machine learning can solve all problems +I give you a collection of images and a + + align:start position:0% +I give you a collection of images and a + + + align:start position:0% +I give you a collection of images and a +collection of radiology reports should + + align:start position:0% +collection of radiology reports should + + + align:start position:0% +collection of radiology reports should +be straightforward to build a model that + + align:start position:0% +be straightforward to build a model that + + + align:start position:0% +be straightforward to build a model that +now takes new radiological images and + + align:start position:0% +now takes new radiological images and + + + align:start position:0% +now takes new radiological images and +produces new radiology reports that are + + align:start position:0% +produces new radiology reports that are + + + align:start position:0% +produces new radiology reports that are +understandable accurate etc I'm joking + + align:start position:0% +understandable accurate etc I'm joking + + + align:start position:0% +understandable accurate etc I'm joking +of course + + align:start position:0% + + + + align:start position:0% + +but the the approach they took was kind + + align:start position:0% +but the the approach they took was kind + + + align:start position:0% +but the the approach they took was kind +of interesting so they taken a standard + + align:start position:0% +of interesting so they taken a standard + + + align:start position:0% +of interesting so they taken a standard +image decoder and then before the + + align:start position:0% +image decoder and then before the + + + align:start position:0% +image decoder and then before the +pooling layer they take essentially an + + align:start position:0% +pooling layer they take essentially an + + + align:start position:0% +pooling layer they take essentially an +image embedding from the next last layer + + align:start position:0% +image embedding from the next last layer + + + align:start position:0% +image embedding from the next last layer +of this imaging coding algorithm and + + align:start position:0% +of this imaging coding algorithm and + + + align:start position:0% +of this imaging coding algorithm and +then they feed that into a word decoder + + align:start position:0% +then they feed that into a word decoder + + + align:start position:0% +then they feed that into a word decoder +and word generator and the idea is to + + align:start position:0% +and word generator and the idea is to + + + align:start position:0% +and word generator and the idea is to +get things that appear in the image that + + align:start position:0% +get things that appear in the image that + + + align:start position:0% +get things that appear in the image that +correspond to words that appear in the + + align:start position:0% +correspond to words that appear in the + + + align:start position:0% +correspond to words that appear in the +report to wind up in the same place in + + align:start position:0% +report to wind up in the same place in + + + align:start position:0% +report to wind up in the same place in +the embedding space and so again there's + + align:start position:0% +the embedding space and so again there's + + + align:start position:0% +the embedding space and so again there's +a lot of hair it's a lsdm based encoder + + align:start position:0% +a lot of hair it's a lsdm based encoder + + + align:start position:0% +a lot of hair it's a lsdm based encoder +and it's modeled as a sentence decoder + + align:start position:0% +and it's modeled as a sentence decoder + + + align:start position:0% +and it's modeled as a sentence decoder +and within that there's a word decoder + + align:start position:0% +and within that there's a word decoder + + + align:start position:0% +and within that there's a word decoder +and then there's a generator + + align:start position:0% +and then there's a generator + + + align:start position:0% +and then there's a generator +that generates these reports and it uses + + align:start position:0% +that generates these reports and it uses + + + align:start position:0% +that generates these reports and it uses +reinforcement learning and it you know + + align:start position:0% +reinforcement learning and it you know + + + align:start position:0% +reinforcement learning and it you know +tons of hair but here's what I wanted to + + align:start position:0% +tons of hair but here's what I wanted to + + + align:start position:0% +tons of hair but here's what I wanted to +show you which is interesting so the + + align:start position:0% +show you which is interesting so the + + + align:start position:0% +show you which is interesting so the +encoder takes a bunch of spatial image + + align:start position:0% +encoder takes a bunch of spatial image + + + align:start position:0% +encoder takes a bunch of spatial image +features the sentence decoder uses these + + align:start position:0% +features the sentence decoder uses these + + + align:start position:0% +features the sentence decoder uses these +image features in addition to the the + + align:start position:0% +image features in addition to the the + + + align:start position:0% +image features in addition to the the +linguistic features the word embeddings + + align:start position:0% +linguistic features the word embeddings + + + align:start position:0% +linguistic features the word embeddings +that are fed into it and then for ground + + align:start position:0% +that are fed into it and then for ground + + + align:start position:0% +that are fed into it and then for ground +truth annotation they also use a remote + + align:start position:0% +truth annotation they also use a remote + + + align:start position:0% +truth annotation they also use a remote +annotation method which is this check + + align:start position:0% +annotation method which is this check + + + align:start position:0% +annotation method which is this check +spurt program which is a rule-based + + align:start position:0% +spurt program which is a rule-based + + + align:start position:0% +spurt program which is a rule-based +program out of stanford that reads + + align:start position:0% +program out of stanford that reads + + + align:start position:0% +program out of stanford that reads +radiology reports and identifies + + align:start position:0% +radiology reports and identifies + + + align:start position:0% +radiology reports and identifies +features in the report that it thinks + + align:start position:0% +features in the report that it thinks + + + align:start position:0% +features in the report that it thinks +are important and correct so it's not + + align:start position:0% +are important and correct so it's not + + + align:start position:0% +are important and correct so it's not +always correct of course but but that's + + align:start position:0% +always correct of course but but that's + + + align:start position:0% +always correct of course but but that's +used in order to guide the generator so + + align:start position:0% +used in order to guide the generator so + + + align:start position:0% +used in order to guide the generator so +here's an example so this is an image of + + align:start position:0% +here's an example so this is an image of + + + align:start position:0% +here's an example so this is an image of +a chest and the ground truth so this is + + align:start position:0% +a chest and the ground truth so this is + + + align:start position:0% +a chest and the ground truth so this is +the actual radiology report says + + align:start position:0% +the actual radiology report says + + + align:start position:0% +the actual radiology report says +cardiomegaly is moderate by basilar + + align:start position:0% +cardiomegaly is moderate by basilar + + + align:start position:0% +cardiomegaly is moderate by basilar +atelectasis is mild + + align:start position:0% +atelectasis is mild + + + align:start position:0% +atelectasis is mild +there's no pneumothorax a lower cervical + + align:start position:0% +there's no pneumothorax a lower cervical + + + align:start position:0% +there's no pneumothorax a lower cervical +spinal fusion is partially visualized + + align:start position:0% +spinal fusion is partially visualized + + + align:start position:0% +spinal fusion is partially visualized +healed right rib fractures are + + align:start position:0% +healed right rib fractures are + + + align:start position:0% +healed right rib fractures are +incidentally noted by the way I've + + align:start position:0% +incidentally noted by the way I've + + + align:start position:0% +incidentally noted by the way I've +stared at hundreds of radiological + + align:start position:0% +stared at hundreds of radiological + + + align:start position:0% +stared at hundreds of radiological +images like this I could never figure + + align:start position:0% +images like this I could never figure + + + align:start position:0% +images like this I could never figure +out that that this image says that but + + align:start position:0% +out that that this image says that but + + + align:start position:0% +out that that this image says that but +that's why radiologists trained for many + + align:start position:0% +that's why radiologists trained for many + + + align:start position:0% +that's why radiologists trained for many +many years to become good at this stuff + + align:start position:0% +many years to become good at this stuff + + + align:start position:0% +many years to become good at this stuff +so there was a previous program done by + + align:start position:0% +so there was a previous program done by + + + align:start position:0% +so there was a previous program done by +others called tie net which generates + + align:start position:0% +others called tie net which generates + + + align:start position:0% +others called tie net which generates +the following report it says ap portable + + align:start position:0% +the following report it says ap portable + + + align:start position:0% +the following report it says ap portable +upright view of the chest there's no + + align:start position:0% +upright view of the chest there's no + + + align:start position:0% +upright view of the chest there's no +pool no focal consolidation effusion or + + align:start position:0% +pool no focal consolidation effusion or + + + align:start position:0% +pool no focal consolidation effusion or +no pneumothorax the cardio meta + + align:start position:0% +no pneumothorax the cardio meta + + + align:start position:0% +no pneumothorax the cardio meta +mediastinal silhouette is normal imaged + + align:start position:0% +mediastinal silhouette is normal imaged + + + align:start position:0% +mediastinal silhouette is normal imaged +us + + align:start position:0% +us + + + align:start position:0% +us +structures are intact so if you compare + + align:start position:0% +structures are intact so if you compare + + + align:start position:0% +structures are intact so if you compare +this to that you say well if the cardio + + align:start position:0% +this to that you say well if the cardio + + + align:start position:0% +this to that you say well if the cardio +mediastinal silhouette is normal then + + align:start position:0% + + + + align:start position:0% + +where would the the lower cervical + + align:start position:0% +where would the the lower cervical + + + align:start position:0% +where would the the lower cervical +spinal fusion being partially visualized + + align:start position:0% +spinal fusion being partially visualized + + + align:start position:0% +spinal fusion being partially visualized +because that's along the middle and so + + align:start position:0% +because that's along the middle and so + + + align:start position:0% +because that's along the middle and so +these are not quite consistent so the + + align:start position:0% +these are not quite consistent so the + + + align:start position:0% +these are not quite consistent so the +system that the students built says + + align:start position:0% +system that the students built says + + + align:start position:0% +system that the students built says +there's mild enlargement of the cardiac + + align:start position:0% +there's mild enlargement of the cardiac + + + align:start position:0% +there's mild enlargement of the cardiac +silhouette there's no pleural effusion + + align:start position:0% +silhouette there's no pleural effusion + + + align:start position:0% +silhouette there's no pleural effusion +or pneumothorax and there's no acute + + align:start position:0% +or pneumothorax and there's no acute + + + align:start position:0% +or pneumothorax and there's no acute +osseous abnormalities so it also missed + + align:start position:0% +osseous abnormalities so it also missed + + + align:start position:0% +osseous abnormalities so it also missed +the healed right rib fractures that were + + align:start position:0% +the healed right rib fractures that were + + + align:start position:0% +the healed right rib fractures that were +incidentally noted but anyway it's you + + align:start position:0% +incidentally noted but anyway it's you + + + align:start position:0% +incidentally noted but anyway it's you +know the remarkable thing about a + + align:start position:0% +know the remarkable thing about a + + + align:start position:0% +know the remarkable thing about a +singing dog is not how well it sings but + + align:start position:0% +singing dog is not how well it sings but + + + align:start position:0% +singing dog is not how well it sings but +the fact that it sings at all + + align:start position:0% +the fact that it sings at all + + + align:start position:0% +the fact that it sings at all +and the reason I included this work is + + align:start position:0% +and the reason I included this work is + + + align:start position:0% +and the reason I included this work is +not to convince you that this is gonna + + align:start position:0% +not to convince you that this is gonna + + + align:start position:0% +not to convince you that this is gonna +replace radiologists anytime soon but + + align:start position:0% +replace radiologists anytime soon but + + + align:start position:0% +replace radiologists anytime soon but +but that it had an interesting + + align:start position:0% +but that it had an interesting + + + align:start position:0% +but that it had an interesting +explanation facility and the explanation + + align:start position:0% +explanation facility and the explanation + + + align:start position:0% +explanation facility and the explanation +facility uses attention which is part of + + align:start position:0% +facility uses attention which is part of + + + align:start position:0% +facility uses attention which is part of +its model to say hey when we reach some + + align:start position:0% +its model to say hey when we reach some + + + align:start position:0% +its model to say hey when we reach some +conclusion we can point back into the + + align:start position:0% +conclusion we can point back into the + + + align:start position:0% +conclusion we can point back into the +image and say what part of the image + + align:start position:0% +image and say what part of the image + + + align:start position:0% +image and say what part of the image +corresponds to that part of the + + align:start position:0% +corresponds to that part of the + + + align:start position:0% +corresponds to that part of the +conclusion and so this is pretty + + align:start position:0% +conclusion and so this is pretty + + + align:start position:0% +conclusion and so this is pretty +interesting you say an upright and + + align:start position:0% +interesting you say an upright and + + + align:start position:0% +interesting you say an upright and +lateral views of the chest in red well + + align:start position:0% +lateral views of the chest in red well + + + align:start position:0% +lateral views of the chest in red well +that's kind of the chest in red + + align:start position:0% +that's kind of the chest in red + + + align:start position:0% +that's kind of the chest in red +there's moderate cardiomegaly so here + + align:start position:0% +there's moderate cardiomegaly so here + + + align:start position:0% +there's moderate cardiomegaly so here +the green certainly shows you where your + + align:start position:0% +the green certainly shows you where your + + + align:start position:0% +the green certainly shows you where your +heart is okay about there and a little + + align:start position:0% +heart is okay about there and a little + + + align:start position:0% +heart is okay about there and a little +bit to the left and there's no pleural + + align:start position:0% +bit to the left and there's no pleural + + + align:start position:0% +bit to the left and there's no pleural +effusion or pneumothorax this one is + + align:start position:0% +effusion or pneumothorax this one is + + + align:start position:0% +effusion or pneumothorax this one is +kind of funny that's the blue region so + + align:start position:0% +kind of funny that's the blue region so + + + align:start position:0% +kind of funny that's the blue region so +how do you show me that there isn't + + align:start position:0% +how do you show me that there isn't + + + align:start position:0% +how do you show me that there isn't +something and we were surprised actually + + align:start position:0% +something and we were surprised actually + + + align:start position:0% +something and we were surprised actually +when the way it showed us that there + + align:start position:0% +when the way it showed us that there + + + align:start position:0% +when the way it showed us that there +isn't something is to highlight + + align:start position:0% +isn't something is to highlight + + + align:start position:0% +isn't something is to highlight +everything + + align:start position:0% +everything + + + align:start position:0% +everything +outside of anything that you might be + + align:start position:0% +outside of anything that you might be + + + align:start position:0% +outside of anything that you might be +interested in which is not exactly + + align:start position:0% +interested in which is not exactly + + + align:start position:0% +interested in which is not exactly +convincing that there's no no pleural + + align:start position:0% +convincing that there's no no pleural + + + align:start position:0% +convincing that there's no no pleural +effusion and here's another example + + align:start position:0% +effusion and here's another example + + + align:start position:0% +effusion and here's another example +there's no relevant change tracheostomy + + align:start position:0% +there's no relevant change tracheostomy + + + align:start position:0% +there's no relevant change tracheostomy +tube is in place so that roughly is + + align:start position:0% +tube is in place so that roughly is + + + align:start position:0% +tube is in place so that roughly is +showing a little too wide but it's + + align:start position:0% +showing a little too wide but it's + + + align:start position:0% +showing a little too wide but it's +showing roughly where a tracheostomy + + align:start position:0% +showing roughly where a tracheostomy + + + align:start position:0% +showing roughly where a tracheostomy +tube might be bilateral pleural effusion + + align:start position:0% +tube might be bilateral pleural effusion + + + align:start position:0% +tube might be bilateral pleural effusion +and compressive analytic ASIS and left + + align:start position:0% +and compressive analytic ASIS and left + + + align:start position:0% +and compressive analytic ASIS and left +ASIS is when your lung tissue stick + + align:start position:0% +ASIS is when your lung tissue stick + + + align:start position:0% +ASIS is when your lung tissue stick +together + + align:start position:0% +together + + + align:start position:0% +together +and so that does often happen in the + + align:start position:0% +and so that does often happen in the + + + align:start position:0% +and so that does often happen in the +lower part of the lung and again the + + align:start position:0% +lower part of the lung and again the + + + align:start position:0% +lower part of the lung and again the +negative shows you everything that's not + + align:start position:0% +negative shows you everything that's not + + + align:start position:0% +negative shows you everything that's not +sort of part of the action yeah + + align:start position:0% + + + + align:start position:0% + +no it's trying to predict the whole + + align:start position:0% +no it's trying to predict the whole + + + align:start position:0% +no it's trying to predict the whole +model the whole note yeah but these guys + + align:start position:0% +model the whole note yeah but these guys + + + align:start position:0% +model the whole note yeah but these guys +were ambitious you know what was it + + align:start position:0% +were ambitious you know what was it + + + align:start position:0% +were ambitious you know what was it +geoff hinton said a few years ago that + + align:start position:0% +geoff hinton said a few years ago that + + + align:start position:0% +geoff hinton said a few years ago that +he wouldn't want his children to become + + align:start position:0% +he wouldn't want his children to become + + + align:start position:0% +he wouldn't want his children to become +radiologists because that field is going + + align:start position:0% +radiologists because that field is going + + + align:start position:0% +radiologists because that field is going +to be replaced by by computers I think + + align:start position:0% +to be replaced by by computers I think + + + align:start position:0% +to be replaced by by computers I think +that was a stupid thing to say + + align:start position:0% +that was a stupid thing to say + + + align:start position:0% +that was a stupid thing to say +especially when you look at the state of + + align:start position:0% +especially when you look at the state of + + + align:start position:0% +especially when you look at the state of +the art of how well these things work + + align:start position:0% +the art of how well these things work + + + align:start position:0% +the art of how well these things work +but if that were true then you would in + + align:start position:0% +but if that were true then you would in + + + align:start position:0% +but if that were true then you would in +fact want something that is able to + + align:start position:0% +fact want something that is able to + + + align:start position:0% +fact want something that is able to +produce an entire radiology report so + + align:start position:0% +produce an entire radiology report so + + + align:start position:0% +produce an entire radiology report so +the motivation is there now after this + + align:start position:0% +the motivation is there now after this + + + align:start position:0% +the motivation is there now after this +work was done we ran into this + + align:start position:0% +work was done we ran into this + + + align:start position:0% +work was done we ran into this +interesting paper from Northeastern + + align:start position:0% +interesting paper from Northeastern + + + align:start position:0% +interesting paper from Northeastern +which says attempt but listen guys + + align:start position:0% +which says attempt but listen guys + + + align:start position:0% +which says attempt but listen guys +attention is not explanation okay + + align:start position:0% +attention is not explanation okay + + + align:start position:0% +attention is not explanation okay +so attention is clearly a mechanism + + align:start position:0% +so attention is clearly a mechanism + + + align:start position:0% +so attention is clearly a mechanism +that's very useful in all kinds of + + align:start position:0% +that's very useful in all kinds of + + + align:start position:0% +that's very useful in all kinds of +machine learning methods but you + + align:start position:0% +machine learning methods but you + + + align:start position:0% +machine learning methods but you +shouldn't confuse it with an explanation + + align:start position:0% +shouldn't confuse it with an explanation + + + align:start position:0% +shouldn't confuse it with an explanation +so they say well assumption it's the + + align:start position:0% +so they say well assumption it's the + + + align:start position:0% +so they say well assumption it's the +assumption that the input units are + + align:start position:0% +assumption that the input units are + + + align:start position:0% +assumption that the input units are +accorded high attention that are + + align:start position:0% +accorded high attention that are + + + align:start position:0% +accorded high attention that are +accorded high attention weights are + + align:start position:0% +accorded high attention weights are + + + align:start position:0% +accorded high attention weights are +responsible through the model outputs + + align:start position:0% +responsible through the model outputs + + + align:start position:0% +responsible through the model outputs +and that may not be true and so what + + align:start position:0% +and that may not be true and so what + + + align:start position:0% +and that may not be true and so what +they did is they did a bunch of + + align:start position:0% +they did is they did a bunch of + + + align:start position:0% +they did is they did a bunch of +experiments where they studied the + + align:start position:0% +experiments where they studied the + + + align:start position:0% +experiments where they studied the +correlation between the attention + + align:start position:0% +correlation between the attention + + + align:start position:0% +correlation between the attention +weights and the the gradients of the + + align:start position:0% +weights and the the gradients of the + + + align:start position:0% +weights and the the gradients of the +model parameters to see whether in fact + + align:start position:0% +model parameters to see whether in fact + + + align:start position:0% +model parameters to see whether in fact +the words that had high attention were + + align:start position:0% +the words that had high attention were + + + align:start position:0% +the words that had high attention were +the ones that were most decisive in + + align:start position:0% +the ones that were most decisive in + + + align:start position:0% +the ones that were most decisive in +making a decision in the model and they + + align:start position:0% +making a decision in the model and they + + + align:start position:0% +making a decision in the model and they +found that the evidence that correlation + + align:start position:0% +found that the evidence that correlation + + + align:start position:0% +found that the evidence that correlation +between intuitive feature importance + + align:start position:0% +between intuitive feature importance + + + align:start position:0% +between intuitive feature importance +measures including gradient and feature + + align:start position:0% +measures including gradient and feature + + + align:start position:0% +measures including gradient and feature +erasure approaches so this is ablation + + align:start position:0% +erasure approaches so this is ablation + + + align:start position:0% +erasure approaches so this is ablation +studies and learned attention weights is + + align:start position:0% +studies and learned attention weights is + + + align:start position:0% +studies and learned attention weights is +weak and so they did a bunch of + + align:start position:0% +weak and so they did a bunch of + + + align:start position:0% +weak and so they did a bunch of +experiments there are a lot of + + align:start position:0% +experiments there are a lot of + + + align:start position:0% +experiments there are a lot of +controversies about this particular + + align:start position:0% +controversies about this particular + + + align:start position:0% +controversies about this particular +study but what you find is that if you + + align:start position:0% +study but what you find is that if you + + + align:start position:0% +study but what you find is that if you +calculate we can + + align:start position:0% +calculate we can + + + align:start position:0% +calculate we can +Corden's you know between on different + + align:start position:0% +Corden's you know between on different + + + align:start position:0% +Corden's you know between on different +data sets using different models you see + + align:start position:0% +data sets using different models you see + + + align:start position:0% +data sets using different models you see +that for example the concordance is not + + align:start position:0% +that for example the concordance is not + + + align:start position:0% +that for example the concordance is not +very high it's less than a half for this + + align:start position:0% +very high it's less than a half for this + + + align:start position:0% +very high it's less than a half for this +data set and you know some of it below + + align:start position:0% +data set and you know some of it below + + + align:start position:0% +data set and you know some of it below +zero so the opposite for this data set + + align:start position:0% +zero so the opposite for this data set + + + align:start position:0% +zero so the opposite for this data set +the interestingly things like like + + align:start position:0% +the interestingly things like like + + + align:start position:0% +the interestingly things like like +diabetes which come from the mimic data + + align:start position:0% +diabetes which come from the mimic data + + + align:start position:0% +diabetes which come from the mimic data +have narrower bounds than some of the + + align:start position:0% +have narrower bounds than some of the + + + align:start position:0% +have narrower bounds than some of the +others so they seem to have a more + + align:start position:0% +others so they seem to have a more + + + align:start position:0% +others so they seem to have a more +definitive conclusion at least for this + + align:start position:0% +definitive conclusion at least for this + + + align:start position:0% +definitive conclusion at least for this +study okay let me finish off by talking + + align:start position:0% +study okay let me finish off by talking + + + align:start position:0% +study okay let me finish off by talking +about the opposite idea + + align:start position:0% +about the opposite idea + + + align:start position:0% +about the opposite idea +so rather than building a complicated + + align:start position:0% +so rather than building a complicated + + + align:start position:0% +so rather than building a complicated +model and then trying to explain it in + + align:start position:0% +model and then trying to explain it in + + + align:start position:0% +model and then trying to explain it in +simple ways what if we just built a + + align:start position:0% +simple ways what if we just built a + + + align:start position:0% +simple ways what if we just built a +simple model and Cynthia Rudin was now a + + align:start position:0% +simple model and Cynthia Rudin was now a + + + align:start position:0% +simple model and Cynthia Rudin was now a +Duke used to be at in the Sloan School + + align:start position:0% +Duke used to be at in the Sloan School + + + align:start position:0% +Duke used to be at in the Sloan School +at MIT has been championing this idea + + align:start position:0% +at MIT has been championing this idea + + + align:start position:0% +at MIT has been championing this idea +for many years and so she has come up + + align:start position:0% +for many years and so she has come up + + + align:start position:0% +for many years and so she has come up +with a bunch of different ideas for how + + align:start position:0% +with a bunch of different ideas for how + + + align:start position:0% +with a bunch of different ideas for how +to build simple models that trade-off + + align:start position:0% +to build simple models that trade-off + + + align:start position:0% +to build simple models that trade-off +maybe a little bit of accuracy in order + + align:start position:0% +maybe a little bit of accuracy in order + + + align:start position:0% +maybe a little bit of accuracy in order +to be explainable and one of her + + align:start position:0% +to be explainable and one of her + + + align:start position:0% +to be explainable and one of her +favorites is this thing called a falling + + align:start position:0% +favorites is this thing called a falling + + + align:start position:0% +favorites is this thing called a falling +rule list so this is an example for a + + align:start position:0% +rule list so this is an example for a + + + align:start position:0% +rule list so this is an example for a +mammographic mass data set so it says if + + align:start position:0% +mammographic mass data set so it says if + + + align:start position:0% +mammographic mass data set so it says if +the if some lump has an irregular shape + + align:start position:0% +the if some lump has an irregular shape + + + align:start position:0% +the if some lump has an irregular shape +and the patient is over 60 years old + + align:start position:0% +and the patient is over 60 years old + + + align:start position:0% +and the patient is over 60 years old +then there's an 85 percent chance of + + align:start position:0% +then there's an 85 percent chance of + + + align:start position:0% +then there's an 85 percent chance of +malignancy risk and there are 230 cases + + align:start position:0% +malignancy risk and there are 230 cases + + + align:start position:0% +malignancy risk and there are 230 cases +in which that happened okay if this is + + align:start position:0% +in which that happened okay if this is + + + align:start position:0% +in which that happened okay if this is +not the case then if the the lump has a + + align:start position:0% +not the case then if the the lump has a + + + align:start position:0% +not the case then if the the lump has a +speculated margin so it has little + + align:start position:0% +speculated margin so it has little + + + align:start position:0% +speculated margin so it has little +spikes coming out of it and the patient + + align:start position:0% +spikes coming out of it and the patient + + + align:start position:0% +spikes coming out of it and the patient +is over 45 then there's a 78% chance of + + align:start position:0% +is over 45 then there's a 78% chance of + + + align:start position:0% +is over 45 then there's a 78% chance of +malignancy and otherwise if the margin + + align:start position:0% +malignancy and otherwise if the margin + + + align:start position:0% +malignancy and otherwise if the margin +is kind of fuzzy the edge of it is kind + + align:start position:0% +is kind of fuzzy the edge of it is kind + + + align:start position:0% +is kind of fuzzy the edge of it is kind +of + + align:start position:0% +of + + + align:start position:0% +of +and the patient is over 60 then there's + + align:start position:0% +and the patient is over 60 then there's + + + align:start position:0% +and the patient is over 60 then there's +a 69% chance and if it has an irregular + + align:start position:0% +a 69% chance and if it has an irregular + + + align:start position:0% +a 69% chance and if it has an irregular +shape then there's a 63% chance and if + + align:start position:0% +shape then there's a 63% chance and if + + + align:start position:0% +shape then there's a 63% chance and if +it's lobular and the density is high + + align:start position:0% +it's lobular and the density is high + + + align:start position:0% +it's lobular and the density is high +then there's a 39% chance and if it's + + align:start position:0% +then there's a 39% chance and if it's + + + align:start position:0% +then there's a 39% chance and if it's +round and the patient is over 60 then + + align:start position:0% +round and the patient is over 60 then + + + align:start position:0% +round and the patient is over 60 then +there's a 26% chance otherwise there's a + + align:start position:0% +there's a 26% chance otherwise there's a + + + align:start position:0% +there's a 26% chance otherwise there's a +10% chance okay and the argument is that + + align:start position:0% +10% chance okay and the argument is that + + + align:start position:0% +10% chance okay and the argument is that +that description of the model the + + align:start position:0% +that description of the model the + + + align:start position:0% +that description of the model the +decision-making model is simple enough + + align:start position:0% +decision-making model is simple enough + + + align:start position:0% +decision-making model is simple enough +that even doctors can understand it he's + + align:start position:0% +that even doctors can understand it he's + + + align:start position:0% +that even doctors can understand it he's +supposed to laugh now there are still + + align:start position:0% +supposed to laugh now there are still + + + align:start position:0% +supposed to laugh now there are still +some problems so one of them is notice + + align:start position:0% +some problems so one of them is notice + + + align:start position:0% +some problems so one of them is notice +some of these are age greater than 60 + + align:start position:0% +some of these are age greater than 60 + + + align:start position:0% +some of these are age greater than 60 +age greater than 45 age greater than 60 + + align:start position:0% +age greater than 45 age greater than 60 + + + align:start position:0% +age greater than 45 age greater than 60 +it's not quite obvious what categories + + align:start position:0% +it's not quite obvious what categories + + + align:start position:0% +it's not quite obvious what categories +that's that's defining and in principle + + align:start position:0% +that's that's defining and in principle + + + align:start position:0% +that's that's defining and in principle +it could be different ages in in + + align:start position:0% +it could be different ages in in + + + align:start position:0% +it could be different ages in in +different ones but here's how they build + + align:start position:0% +different ones but here's how they build + + + align:start position:0% +different ones but here's how they build +it so this is a very simple model that's + + align:start position:0% +it so this is a very simple model that's + + + align:start position:0% +it so this is a very simple model that's +built by a very complicated process so + + align:start position:0% +built by a very complicated process so + + + align:start position:0% +built by a very complicated process so +the simple model is the one I've just + + align:start position:0% +the simple model is the one I've just + + + align:start position:0% +the simple model is the one I've just +showed you and there's a Bayesian + + align:start position:0% +showed you and there's a Bayesian + + + align:start position:0% +showed you and there's a Bayesian +approach a Bayesian generative approach + + align:start position:0% +approach a Bayesian generative approach + + + align:start position:0% +approach a Bayesian generative approach +where they have a bunch of hyper + + align:start position:0% +where they have a bunch of hyper + + + align:start position:0% +where they have a bunch of hyper +parameters falling rulest parameters + + align:start position:0% +parameters falling rulest parameters + + + align:start position:0% +parameters falling rulest parameters +theta they calculate a likelihood which + + align:start position:0% +theta they calculate a likelihood which + + + align:start position:0% +theta they calculate a likelihood which +is given a particular theta how likely + + align:start position:0% +is given a particular theta how likely + + + align:start position:0% +is given a particular theta how likely +are you to get the answers that are + + align:start position:0% +are you to get the answers that are + + + align:start position:0% +are you to get the answers that are +actually in your data given the model + + align:start position:0% +actually in your data given the model + + + align:start position:0% +actually in your data given the model +that you generate and they start with a + + align:start position:0% +that you generate and they start with a + + + align:start position:0% +that you generate and they start with a +possible set of if clauses so they do + + align:start position:0% +possible set of if clauses so they do + + + align:start position:0% +possible set of if clauses so they do +frequent Clause mining to say what + + align:start position:0% +frequent Clause mining to say what + + + align:start position:0% +frequent Clause mining to say what +conditions what binary conditions occur + + align:start position:0% +conditions what binary conditions occur + + + align:start position:0% +conditions what binary conditions occur +frequently together in the database and + + align:start position:0% +frequently together in the database and + + + align:start position:0% +frequently together in the database and +those are the only ones that are going + + align:start position:0% +those are the only ones that are going + + + align:start position:0% +those are the only ones that are going +to consider because of course the number + + align:start position:0% +to consider because of course the number + + + align:start position:0% +to consider because of course the number +of possible clauses is vast and they + + align:start position:0% +of possible clauses is vast and they + + + align:start position:0% +of possible clauses is vast and they +don't want to have to iterate through + + align:start position:0% +don't want to have to iterate through + + + align:start position:0% +don't want to have to iterate through +those and then for each setup for each + + align:start position:0% +those and then for each setup for each + + + align:start position:0% +those and then for each setup for each +Clause they they calculate a risk score + + align:start position:0% +Clause they they calculate a risk score + + + align:start position:0% +Clause they they calculate a risk score +which + + align:start position:0% +which + + + align:start position:0% +which +is generated by a by a probability + + align:start position:0% +is generated by a by a probability + + + align:start position:0% +is generated by a by a probability +distribution under the constraint that + + align:start position:0% +distribution under the constraint that + + + align:start position:0% +distribution under the constraint that +the risk score for the next Clause is + + align:start position:0% +the risk score for the next Clause is + + + align:start position:0% +the risk score for the next Clause is +lower or equal to the risk score for the + + align:start position:0% +lower or equal to the risk score for the + + + align:start position:0% +lower or equal to the risk score for the +previous Clause okay there are lots of + + align:start position:0% +previous Clause okay there are lots of + + + align:start position:0% +previous Clause okay there are lots of +details so there's this frequent + + align:start position:0% +details so there's this frequent + + + align:start position:0% +details so there's this frequent +itemsets mining algorithm it turns out + + align:start position:0% +itemsets mining algorithm it turns out + + + align:start position:0% +itemsets mining algorithm it turns out +that choosing our R sub L to be the logs + + align:start position:0% +that choosing our R sub L to be the logs + + + align:start position:0% +that choosing our R sub L to be the logs +of products of real numbers is an + + align:start position:0% +of products of real numbers is an + + + align:start position:0% +of products of real numbers is an +important step in order to guarantee + + align:start position:0% +important step in order to guarantee + + + align:start position:0% +important step in order to guarantee +that monotonicity constraint in a simple + + align:start position:0% +that monotonicity constraint in a simple + + + align:start position:0% +that monotonicity constraint in a simple +way L the number of clauses is drawn + + align:start position:0% +way L the number of clauses is drawn + + + align:start position:0% +way L the number of clauses is drawn +from a Poisson distribution and you give + + align:start position:0% +from a Poisson distribution and you give + + + align:start position:0% +from a Poisson distribution and you give +it a kind of scale that says roughly how + + align:start position:0% +it a kind of scale that says roughly how + + + align:start position:0% +it a kind of scale that says roughly how +many clauses would you be willing to + + align:start position:0% +many clauses would you be willing to + + + align:start position:0% +many clauses would you be willing to +tolerate in your in your following rule + + align:start position:0% +tolerate in your in your following rule + + + align:start position:0% +tolerate in your in your following rule +list and then there's a lot of + + align:start position:0% +list and then there's a lot of + + + align:start position:0% +list and then there's a lot of +computational hair where they do they + + align:start position:0% +computational hair where they do they + + + align:start position:0% +computational hair where they do they +get mean a posterior a probability + + align:start position:0% +get mean a posterior a probability + + + align:start position:0% +get mean a posterior a probability +estimation by using a simulated + + align:start position:0% +estimation by using a simulated + + + align:start position:0% +estimation by using a simulated +annealing algorithm so they basically + + align:start position:0% +annealing algorithm so they basically + + + align:start position:0% +annealing algorithm so they basically +generate some clauses and then they use + + align:start position:0% +generate some clauses and then they use + + + align:start position:0% +generate some clauses and then they use +swap replace add and delete operators in + + align:start position:0% +swap replace add and delete operators in + + + align:start position:0% +swap replace add and delete operators in +order to try different variations and + + align:start position:0% +order to try different variations and + + + align:start position:0% +order to try different variations and +they're doing hill climbing in that + + align:start position:0% +they're doing hill climbing in that + + + align:start position:0% +they're doing hill climbing in that +space there's also some Gibbs sampling + + align:start position:0% +space there's also some Gibbs sampling + + + align:start position:0% +space there's also some Gibbs sampling +because once you have one of these + + align:start position:0% +because once you have one of these + + + align:start position:0% +because once you have one of these +models simply calculating how accurate + + align:start position:0% +models simply calculating how accurate + + + align:start position:0% +models simply calculating how accurate +it is is not straightforward there's not + + align:start position:0% +it is is not straightforward there's not + + + align:start position:0% +it is is not straightforward there's not +a closed-form way of doing it and so + + align:start position:0% +a closed-form way of doing it and so + + + align:start position:0% +a closed-form way of doing it and so +they're doing sampling in order to try + + align:start position:0% +they're doing sampling in order to try + + + align:start position:0% +they're doing sampling in order to try +to generate that so it's a bunch of hair + + align:start position:0% +to generate that so it's a bunch of hair + + + align:start position:0% +to generate that so it's a bunch of hair +and again the paper describes it all + + align:start position:0% +and again the paper describes it all + + + align:start position:0% +and again the paper describes it all +well what's interesting is that on a 30 + + align:start position:0% +well what's interesting is that on a 30 + + + align:start position:0% +well what's interesting is that on a 30 +day hospital readmission data set with + + align:start position:0% +day hospital readmission data set with + + + align:start position:0% +day hospital readmission data set with +about 8,000 patients they used about 34 + + align:start position:0% +about 8,000 patients they used about 34 + + + align:start position:0% +about 8,000 patients they used about 34 +features like impaired Mental Status + + align:start position:0% +features like impaired Mental Status + + + align:start position:0% +features like impaired Mental Status +difficult behavior + + align:start position:0% +difficult behavior + + + align:start position:0% +difficult behavior +pain feels unsafe etc they mind rules or + + align:start position:0% +pain feels unsafe etc they mind rules or + + + align:start position:0% +pain feels unsafe etc they mind rules or +clauses with support more than 5% of the + + align:start position:0% +clauses with support more than 5% of the + + + align:start position:0% +clauses with support more than 5% of the +database and no more than two conditions + + align:start position:0% +database and no more than two conditions + + + align:start position:0% +database and no more than two conditions +they set the expected length of the + + align:start position:0% +they set the expected length of the + + + align:start position:0% +they set the expected length of the +decision list to be 8 clauses and then + + align:start position:0% +decision list to be 8 clauses and then + + + align:start position:0% +decision list to be 8 clauses and then +they compared the decision model they + + align:start position:0% +they compared the decision model they + + + align:start position:0% +they compared the decision model they +got to SVM's random forest logistic + + align:start position:0% +got to SVM's random forest logistic + + + align:start position:0% +got to SVM's random forest logistic +regression cart and an inductive logic + + align:start position:0% +regression cart and an inductive logic + + + align:start position:0% +regression cart and an inductive logic +programming approach and shockingly to + + align:start position:0% +programming approach and shockingly to + + + align:start position:0% +programming approach and shockingly to +me their method the falling rulest + + align:start position:0% +me their method the falling rulest + + + align:start position:0% +me their method the falling rulest +method got an a you see of about 0.8 + + align:start position:0% +method got an a you see of about 0.8 + + + align:start position:0% +method got an a you see of about 0.8 +whereas all the others did like 0.7 9.75 + + align:start position:0% +whereas all the others did like 0.7 9.75 + + + align:start position:0% +whereas all the others did like 0.7 9.75 +logistic regression as usual + + align:start position:0% +logistic regression as usual + + + align:start position:0% +logistic regression as usual +outperformed the one they got slightly + + align:start position:0% +outperformed the one they got slightly + + + align:start position:0% +outperformed the one they got slightly +right but this is interesting because + + align:start position:0% +right but this is interesting because + + + align:start position:0% +right but this is interesting because +their argument is that this + + align:start position:0% +their argument is that this + + + align:start position:0% +their argument is that this +representation of the model is much more + + align:start position:0% +representation of the model is much more + + + align:start position:0% +representation of the model is much more +easy to understand than even a logistic + + align:start position:0% +easy to understand than even a logistic + + + align:start position:0% +easy to understand than even a logistic +regression model for most human human + + align:start position:0% +regression model for most human human + + + align:start position:0% +regression model for most human human +users and also if you look at these are + + align:start position:0% +users and also if you look at these are + + + align:start position:0% +users and also if you look at these are +just various runs and the different + + align:start position:0% +just various runs and the different + + + align:start position:0% +just various runs and the different +models and their model has a pretty + + align:start position:0% +models and their model has a pretty + + + align:start position:0% +models and their model has a pretty +decent day you see up here I think the + + align:start position:0% +decent day you see up here I think the + + + align:start position:0% +decent day you see up here I think the +green one is the logistic regression one + + align:start position:0% +green one is the logistic regression one + + + align:start position:0% +green one is the logistic regression one +and it it's slightly better because it + + align:start position:0% +and it it's slightly better because it + + + align:start position:0% +and it it's slightly better because it +outperforms their best model in the + + align:start position:0% +outperforms their best model in the + + + align:start position:0% +outperforms their best model in the +region of low false positive rates which + + align:start position:0% +region of low false positive rates which + + + align:start position:0% +region of low false positive rates which +may be where you want to operate so that + + align:start position:0% +may be where you want to operate so that + + + align:start position:0% +may be where you want to operate so that +may actually be a better model so here's + + align:start position:0% +may actually be a better model so here's + + + align:start position:0% +may actually be a better model so here's +their readmission rule list and it says + + align:start position:0% +their readmission rule list and it says + + + align:start position:0% +their readmission rule list and it says +if the patient has bedsores and has a + + align:start position:0% +if the patient has bedsores and has a + + + align:start position:0% +if the patient has bedsores and has a +history of not showing up for + + align:start position:0% +history of not showing up for + + + align:start position:0% +history of not showing up for +appointments then there's a 33% + + align:start position:0% +appointments then there's a 33% + + + align:start position:0% +appointments then there's a 33% +probability that they'll be readmitted + + align:start position:0% +probability that they'll be readmitted + + + align:start position:0% +probability that they'll be readmitted +within 30 days if I think some note says + + align:start position:0% +within 30 days if I think some note says + + + align:start position:0% +within 30 days if I think some note says +poor prognosis and maximum care etc so + + align:start position:0% +poor prognosis and maximum care etc so + + + align:start position:0% +poor prognosis and maximum care etc so +this is the result that they came up + + align:start position:0% +this is the result that they came up + + + align:start position:0% +this is the result that they came up +with now by the way we've talked a + + align:start position:0% +with now by the way we've talked a + + + align:start position:0% +with now by the way we've talked a +little bit about a 30 day readmission + + align:start position:0% +little bit about a 30 day readmission + + + align:start position:0% +little bit about a 30 day readmission +predictions and getting over about 70% + + align:start position:0% +predictions and getting over about 70% + + + align:start position:0% +predictions and getting over about 70% +is not bad in that domain because it's + + align:start position:0% +is not bad in that domain because it's + + + align:start position:0% +is not bad in that domain because it's +just not that easily predictable who's + + align:start position:0% +just not that easily predictable who's + + + align:start position:0% +just not that easily predictable who's +gonna wind up back in the hospital + + align:start position:0% +gonna wind up back in the hospital + + + align:start position:0% +gonna wind up back in the hospital +within 30 days so these models are + + align:start position:0% +within 30 days so these models are + + + align:start position:0% +within 30 days so these models are +actually doing quite well and certainly + + align:start position:0% +actually doing quite well and certainly + + + align:start position:0% +actually doing quite well and certainly +understandable in these terms they also + + align:start position:0% +understandable in these terms they also + + + align:start position:0% +understandable in these terms they also +tried on a variety of University of + + align:start position:0% +tried on a variety of University of + + + align:start position:0% +tried on a variety of University of +california-irvine machine learning data + + align:start position:0% +california-irvine machine learning data + + + align:start position:0% +california-irvine machine learning data +sets these are just random public data + + align:start position:0% +sets these are just random public data + + + align:start position:0% +sets these are just random public data +sets and they tried building these + + align:start position:0% +sets and they tried building these + + + align:start position:0% +sets and they tried building these +falling rulest models to make + + align:start position:0% +falling rulest models to make + + + align:start position:0% +falling rulest models to make +predictions and what you see is that the + + align:start position:0% +predictions and what you see is that the + + + align:start position:0% +predictions and what you see is that the +au C's are pretty good so on the spam + + align:start position:0% +au C's are pretty good so on the spam + + + align:start position:0% +au C's are pretty good so on the spam +detection data set their system gets + + align:start position:0% +detection data set their system gets + + + align:start position:0% +detection data set their system gets +about 91 logistic regression again gets + + align:start position:0% +about 91 logistic regression again gets + + + align:start position:0% +about 91 logistic regression again gets +97 so you know part of the unfortunate + + align:start position:0% +97 so you know part of the unfortunate + + + align:start position:0% +97 so you know part of the unfortunate +lesson that we we teach in almost every + + align:start position:0% +lesson that we we teach in almost every + + + align:start position:0% +lesson that we we teach in almost every +example in this class is the simple + + align:start position:0% +example in this class is the simple + + + align:start position:0% +example in this class is the simple +models like logistic regression often do + + align:start position:0% +models like logistic regression often do + + + align:start position:0% +models like logistic regression often do +quite well but remember here they're + + align:start position:0% +quite well but remember here they're + + + align:start position:0% +quite well but remember here they're +optimizing for explained ability rather + + align:start position:0% +optimizing for explained ability rather + + + align:start position:0% +optimizing for explained ability rather +than for getting the right answer so + + align:start position:0% +than for getting the right answer so + + + align:start position:0% +than for getting the right answer so +they're willing to sacrifice some + + align:start position:0% +they're willing to sacrifice some + + + align:start position:0% +they're willing to sacrifice some +accuracy in their model in order to + + align:start position:0% +accuracy in their model in order to + + + align:start position:0% +accuracy in their model in order to +develop a result that is easy to explain + + align:start position:0% +develop a result that is easy to explain + + + align:start position:0% +develop a result that is easy to explain +to people so again there are many + + align:start position:0% +to people so again there are many + + + align:start position:0% +to people so again there are many +variations on this type of work where + + align:start position:0% +variations on this type of work where + + + align:start position:0% +variations on this type of work where +people have different notions of what + + align:start position:0% +people have different notions of what + + + align:start position:0% +people have different notions of what +counts as a simple explainable model but + + align:start position:0% +counts as a simple explainable model but + + + align:start position:0% +counts as a simple explainable model but +that's a very different approach than + + align:start position:0% +that's a very different approach than + + + align:start position:0% +that's a very different approach than +the Lyme approach which says build the + + align:start position:0% +the Lyme approach which says build the + + + align:start position:0% +the Lyme approach which says build the +Harry model and then produce local + + align:start position:0% +Harry model and then produce local + + + align:start position:0% +Harry model and then produce local +explanations for why it makes certain + + align:start position:0% +explanations for why it makes certain + + + align:start position:0% +explanations for why it makes certain +decisions on particular cases all right + + align:start position:0% +decisions on particular cases all right + + + align:start position:0% +decisions on particular cases all right +I think that's all I'm going to say + + align:start position:0% +I think that's all I'm going to say + + + align:start position:0% +I think that's all I'm going to say +about explain ability this is a very hot + + align:start position:0% +about explain ability this is a very hot + + + align:start position:0% +about explain ability this is a very hot +topic at the moment and so there are + + align:start position:0% +topic at the moment and so there are + + + align:start position:0% +topic at the moment and so there are +lots of papers + + align:start position:0% +lots of papers + + + align:start position:0% +lots of papers +I think there's I just saw a call for a + + align:start position:0% +I think there's I just saw a call for a + + + align:start position:0% +I think there's I just saw a call for a +conference on explainable machine + + align:start position:0% +conference on explainable machine + + + align:start position:0% +conference on explainable machine +learning models so there's more and more + + align:start position:0% +learning models so there's more and more + + + align:start position:0% +learning models so there's more and more +working in this area so with that we + + align:start position:0% +working in this area so with that we + + + align:start position:0% +working in this area so with that we +come to the end of our + + align:start position:0% +come to the end of our + + + align:start position:0% +come to the end of our +and I just wanted I just went through + + align:start position:0% +and I just wanted I just went through + + + align:start position:0% +and I just wanted I just went through +the the front page of the course website + + align:start position:0% +the the front page of the course website + + + align:start position:0% +the the front page of the course website +and listed all the topics so we've + + align:start position:0% +and listed all the topics so we've + + + align:start position:0% +and listed all the topics so we've +covered quite a lot of stuff right you + + align:start position:0% +covered quite a lot of stuff right you + + + align:start position:0% +covered quite a lot of stuff right you +know what what makes healthcare + + align:start position:0% +know what what makes healthcare + + + align:start position:0% +know what what makes healthcare +different and we talked about what + + align:start position:0% +different and we talked about what + + + align:start position:0% +different and we talked about what +clinical care is all about and what + + align:start position:0% +clinical care is all about and what + + + align:start position:0% +clinical care is all about and what +clinical data is like and risk + + align:start position:0% +clinical data is like and risk + + + align:start position:0% +clinical data is like and risk +stratification survival modeling + + align:start position:0% +stratification survival modeling + + + align:start position:0% +stratification survival modeling +physiological time-series how to + + align:start position:0% +physiological time-series how to + + + align:start position:0% +physiological time-series how to +interpret clinical text in a couple of + + align:start position:0% +interpret clinical text in a couple of + + + align:start position:0% +interpret clinical text in a couple of +lectures translating technology into the + + align:start position:0% +lectures translating technology into the + + + align:start position:0% +lectures translating technology into the +clinic the italicized ones were guest + + align:start position:0% +clinic the italicized ones were guest + + + align:start position:0% +clinic the italicized ones were guest +lecturers so machine learning for + + align:start position:0% +lecturers so machine learning for + + + align:start position:0% +lecturers so machine learning for +cardiology and machine learning for + + align:start position:0% +cardiology and machine learning for + + + align:start position:0% +cardiology and machine learning for +differential diagnosis machine learning + + align:start position:0% +differential diagnosis machine learning + + + align:start position:0% +differential diagnosis machine learning +for pathology for mammography David gave + + align:start position:0% +for pathology for mammography David gave + + + align:start position:0% +for pathology for mammography David gave +a couple of lectures on causal inference + + align:start position:0% +a couple of lectures on causal inference + + + align:start position:0% +a couple of lectures on causal inference +and reinforcement learning or David and + + align:start position:0% +and reinforcement learning or David and + + + align:start position:0% +and reinforcement learning or David and +a guest which I I didn't note here + + align:start position:0% +a guest which I I didn't note here + + + align:start position:0% +a guest which I I didn't note here +disease progression and subtyping we + + align:start position:0% +disease progression and subtyping we + + + align:start position:0% +disease progression and subtyping we +talked about precision medicine and the + + align:start position:0% +talked about precision medicine and the + + + align:start position:0% +talked about precision medicine and the +role of genetics automating clinical + + align:start position:0% +role of genetics automating clinical + + + align:start position:0% +role of genetics automating clinical +workflows the lecture on regulation and + + align:start position:0% +workflows the lecture on regulation and + + + align:start position:0% +workflows the lecture on regulation and +then recently fairness robustness the + + align:start position:0% +then recently fairness robustness the + + + align:start position:0% +then recently fairness robustness the +data set shift and interpretability + + align:start position:0% +data set shift and interpretability + + + align:start position:0% +data set shift and interpretability +so that's quite a lot we I think we're + + align:start position:0% +so that's quite a lot we I think we're + + + align:start position:0% +so that's quite a lot we I think we're +we the staff are pretty happy with how + + align:start position:0% +we the staff are pretty happy with how + + + align:start position:0% +we the staff are pretty happy with how +the class has gone it was our first time + + align:start position:0% +the class has gone it was our first time + + + align:start position:0% +the class has gone it was our first time +as this crew teaching it and we hope to + + align:start position:0% +as this crew teaching it and we hope to + + + align:start position:0% +as this crew teaching it and we hope to +do it again I can't stop without giving + + align:start position:0% +do it again I can't stop without giving + + + align:start position:0% +do it again I can't stop without giving +an immense vote of gratitude to Irene + + align:start position:0% +an immense vote of gratitude to Irene + + + align:start position:0% +an immense vote of gratitude to Irene +and Willi without whom we would have + + align:start position:0% +and Willi without whom we would have + + + align:start position:0% +and Willi without whom we would have +been totally sunk + + align:start position:0% + + + + align:start position:0% + +and I also want to acknowledge David's + + align:start position:0% +and I also want to acknowledge David's + + + align:start position:0% +and I also want to acknowledge David's +vision and putting this course together + + align:start position:0% +vision and putting this course together + + + align:start position:0% +vision and putting this course together +he taught a sort of half-size version of + + align:start position:0% +he taught a sort of half-size version of + + + align:start position:0% +he taught a sort of half-size version of +a class like this a couple of years ago + + align:start position:0% +a class like this a couple of years ago + + + align:start position:0% +a class like this a couple of years ago +and thought that it would be a good idea + + align:start position:0% +and thought that it would be a good idea + + + align:start position:0% +and thought that it would be a good idea +to expand it into a full semester a + + align:start position:0% +to expand it into a full semester a + + + align:start position:0% +to expand it into a full semester a +regular course and got me on board to + + align:start position:0% +regular course and got me on board to + + + align:start position:0% +regular course and got me on board to +work with them and I want to thank you + + align:start position:0% +work with them and I want to thank you + + + align:start position:0% +work with them and I want to thank you +all for your hard work and I and I'm + + align:start position:0% +all for your hard work and I and I'm + + + align:start position:0% +all for your hard work and I and I'm +looking forward to \ No newline at end of file diff --git a/wEyKvA_O-n4.txt b/wEyKvA_O-n4.txt new file mode 100644 index 0000000000000000000000000000000000000000..b99ce344a3e5f58f4b31e3fd7feeb32a177a05bf --- /dev/null +++ b/wEyKvA_O-n4.txt @@ -0,0 +1,619 @@ +align:start position:0% + +here I made the list of the ingredients + + align:start position:0% +here I made the list of the ingredients + + + align:start position:0% +here I made the list of the ingredients +with ingredients for the meatballs this + + align:start position:0% +with ingredients for the meatballs this + + + align:start position:0% +with ingredients for the meatballs this +is the ingredient tea for this + + align:start position:0% +is the ingredient tea for this + + + align:start position:0% +is the ingredient tea for this +and this is foreign + + align:start position:0% + + + + align:start position:0% + +so what is the idea + + align:start position:0% +so what is the idea + + + align:start position:0% +so what is the idea +well you just have to mince chop ground + + align:start position:0% +well you just have to mince chop ground + + + align:start position:0% +well you just have to mince chop ground +everything make little balls you can + + align:start position:0% +everything make little balls you can + + + align:start position:0% +everything make little balls you can +make them smaller than + + align:start position:0% +make them smaller than + + + align:start position:0% +make them smaller than +if they cook faster and then what I was + + align:start position:0% +if they cook faster and then what I was + + + align:start position:0% +if they cook faster and then what I was +thinking is that we could cook the + + align:start position:0% +thinking is that we could cook the + + + align:start position:0% +thinking is that we could cook the +meatballs + + align:start position:0% +meatballs + + + align:start position:0% +meatballs +foreign + + align:start position:0% + + + + align:start position:0% + +foreign + + align:start position:0% + + + + align:start position:0% + +then you take the salsicha you want to + + align:start position:0% +then you take the salsicha you want to + + + align:start position:0% +then you take the salsicha you want to +take the skin off so that and then you + + align:start position:0% +take the skin off so that and then you + + + align:start position:0% +take the skin off so that and then you +can use the sausage + + align:start position:0% +can use the sausage + + + align:start position:0% +can use the sausage +yes + + align:start position:0% + + + + align:start position:0% + +very very very small yes very small + + align:start position:0% +very very very small yes very small + + + align:start position:0% +very very very small yes very small +because then you're going to mix + + align:start position:0% +because then you're going to mix + + + align:start position:0% +because then you're going to mix +everything together and then wash the + + align:start position:0% +everything together and then wash the + + + align:start position:0% +everything together and then wash the +Brazil and you can use yes you chop it + + align:start position:0% +Brazil and you can use yes you chop it + + + align:start position:0% +Brazil and you can use yes you chop it +and you put it in there okay okay so + + align:start position:0% +and you put it in there okay okay so + + + align:start position:0% +and you put it in there okay okay so +it's a traditional + + align:start position:0% +it's a traditional + + + align:start position:0% +it's a traditional +we would also add the input + + align:start position:0% +we would also add the input + + + align:start position:0% +we would also add the input +but I thought we could make a version + + align:start position:0% +but I thought we could make a version + + + align:start position:0% +but I thought we could make a version +that's a little bit lighter okay so + + align:start position:0% +that's a little bit lighter okay so + + + align:start position:0% +that's a little bit lighter okay so +let's try without this okay but don't + + align:start position:0% +let's try without this okay but don't + + + align:start position:0% +let's try without this okay but don't +forget to add salad and then you will + + align:start position:0% +forget to add salad and then you will + + + align:start position:0% +forget to add salad and then you will +cook it in the pan + + align:start position:0% +cook it in the pan + + + align:start position:0% +cook it in the pan +you have different options you can um + + align:start position:0% +you have different options you can um + + + align:start position:0% +you have different options you can um +but I would avoid for frying yeah + + align:start position:0% +but I would avoid for frying yeah + + + align:start position:0% +but I would avoid for frying yeah +so what you can do maybe you can make a + + align:start position:0% +so what you can do maybe you can make a + + + align:start position:0% +so what you can do maybe you can make a +Sofrito + + align:start position:0% + + + + align:start position:0% + +you put a lot of Chipola + + align:start position:0% + + + + align:start position:0% + +you know this one works better yeah + + align:start position:0% +you know this one works better yeah + + + align:start position:0% +you know this one works better yeah +this is the best so great + + align:start position:0% + + + + align:start position:0% + +it's gonna come out you will see a + + align:start position:0% +it's gonna come out you will see a + + + align:start position:0% +it's gonna come out you will see a +different consistency longer more fluffy + + align:start position:0% +different consistency longer more fluffy + + + align:start position:0% +different consistency longer more fluffy +yeah so it's really good then you want + + align:start position:0% +yeah so it's really good then you want + + + align:start position:0% +yeah so it's really good then you want +to mix everything together make little + + align:start position:0% +to mix everything together make little + + + align:start position:0% +to mix everything together make little +balls and then you cook them in the pan + + align:start position:0% +balls and then you cook them in the pan + + + align:start position:0% +balls and then you cook them in the pan +slow heat with a little bit of oil so + + align:start position:0% +slow heat with a little bit of oil so + + + align:start position:0% +slow heat with a little bit of oil so +wash the zucchini you're starting to + + align:start position:0% +wash the zucchini you're starting to + + + align:start position:0% +wash the zucchini you're starting to +chop them that's fine but it's fast + + align:start position:0% +chop them that's fine but it's fast + + + align:start position:0% +chop them that's fine but it's fast +sorry if you use the grater okay and + + align:start position:0% +sorry if you use the grater okay and + + + align:start position:0% +sorry if you use the grater okay and +they're they're not gonna come out too + + align:start position:0% +they're they're not gonna come out too + + + align:start position:0% +they're they're not gonna come out too +much thinner then you can use them + + align:start position:0% +much thinner then you can use them + + + align:start position:0% +much thinner then you can use them +directly as they are or I prefer to + + align:start position:0% +directly as they are or I prefer to + + + align:start position:0% +directly as they are or I prefer to +cook them with some Sofrito to add a + + align:start position:0% +cook them with some Sofrito to add a + + + align:start position:0% +cook them with some Sofrito to add a +little bit of taste so you can mix Frito + + align:start position:0% +little bit of taste so you can mix Frito + + + align:start position:0% +little bit of taste so you can mix Frito +with algae and your favorite space + + align:start position:0% + + + + align:start position:0% + +spices and also in this way they're + + align:start position:0% +spices and also in this way they're + + + align:start position:0% +spices and also in this way they're +going to release some of the water + + align:start position:0% +going to release some of the water + + + align:start position:0% +going to release some of the water +otherwise they come out like very very + + align:start position:0% +otherwise they come out like very very + + + align:start position:0% +otherwise they come out like very very +watery okay then you let them cool you + + align:start position:0% +watery okay then you let them cool you + + + align:start position:0% +watery okay then you let them cool you +mix them with the rest of the + + align:start position:0% +mix them with the rest of the + + + align:start position:0% +mix them with the rest of the +ingredients make little balls and then + + align:start position:0% +ingredients make little balls and then + + + align:start position:0% +ingredients make little balls and then +you put them + + align:start position:0% + + + + align:start position:0% + +yes + + align:start position:0% + + + + align:start position:0% + +very hungry yes and this is + + align:start position:0% + + + + align:start position:0% + +it goes so fast + + align:start position:0% + + + + align:start position:0% + +I find it a little bit more tasty + + align:start position:0% +I find it a little bit more tasty + + + align:start position:0% +I find it a little bit more tasty +but usually + + align:start position:0% +but usually + + + align:start position:0% +but usually +because it has been in the can it's not + + align:start position:0% +because it has been in the can it's not + + + align:start position:0% +because it has been in the can it's not +like the best quality so you want to + + align:start position:0% +like the best quality so you want to + + + align:start position:0% +like the best quality so you want to +drain it + + align:start position:0% +drain it + + + align:start position:0% +drain it +okay it's okay it's not a big deal if + + align:start position:0% +okay it's okay it's not a big deal if + + + align:start position:0% +okay it's okay it's not a big deal if +you added some + + align:start position:0% + + + + align:start position:0% + +foreign + + align:start position:0% + + + + align:start position:0% + +so right now we're making this mix into + + align:start position:0% +so right now we're making this mix into + + + align:start position:0% +so right now we're making this mix into +tiny little balls and then we're gonna + + align:start position:0% +tiny little balls and then we're gonna + + + align:start position:0% +tiny little balls and then we're gonna +cover them + + align:start position:0% + + + + align:start position:0% + +so then again it has kind of make sure + + align:start position:0% +so then again it has kind of make sure + + + align:start position:0% +so then again it has kind of make sure +yeah yeah when we fry them okay + + align:start position:0% +yeah yeah when we fry them okay + + + align:start position:0% +yeah yeah when we fry them okay +okay + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +foreign + + align:start position:0% + + + + align:start position:0% + +foreign \ No newline at end of file diff --git a/wQBSalAFFC4.txt b/wQBSalAFFC4.txt new file mode 100644 index 0000000000000000000000000000000000000000..9accbe22d7b7ae08142e35119c35f69c6b31d5ae --- /dev/null +++ b/wQBSalAFFC4.txt @@ -0,0 +1,11882 @@ +align:start position:0% + +hello can people hear me in the + + align:start position:0% +hello can people hear me in the + + + align:start position:0% +hello can people hear me in the +back yeah thumbs up + + align:start position:0% +back yeah thumbs up + + + align:start position:0% +back yeah thumbs up +okay uh so today we're going to be + + align:start position:0% +okay uh so today we're going to be + + + align:start position:0% +okay uh so today we're going to be +continuing our discussion of uh + + align:start position:0% +continuing our discussion of uh + + + align:start position:0% +continuing our discussion of uh +probability uh in the last lecture we + + align:start position:0% +probability uh in the last lecture we + + + align:start position:0% +probability uh in the last lecture we +saw uh how to compute probabilities + + align:start position:0% +saw uh how to compute probabilities + + + align:start position:0% +saw uh how to compute probabilities +using the uh oh dear uh using the uh + + align:start position:0% +using the uh oh dear uh using the uh + + + align:start position:0% +using the uh oh dear uh using the uh +tree method and this lecture we are + + align:start position:0% +tree method and this lecture we are + + + align:start position:0% +tree method and this lecture we are +going to uh you know see how some of the + + align:start position:0% +going to uh you know see how some of the + + + align:start position:0% +going to uh you know see how some of the +tools that we learned in the last unit + + align:start position:0% +tools that we learned in the last unit + + + align:start position:0% +tools that we learned in the last unit +for + + align:start position:0% +for + + + align:start position:0% +for +counting uh for for reasoning about the + + align:start position:0% +counting uh for for reasoning about the + + + align:start position:0% +counting uh for for reasoning about the +sizes of sets and things like that can + + align:start position:0% +sizes of sets and things like that can + + + align:start position:0% +sizes of sets and things like that can +also carry over naturally into the uh + + align:start position:0% +also carry over naturally into the uh + + + align:start position:0% +also carry over naturally into the uh +into the realm of probability okay uh + + align:start position:0% +into the realm of probability okay uh + + + align:start position:0% +into the realm of probability okay uh +and we'll also learn how to express + + align:start position:0% +and we'll also learn how to express + + + align:start position:0% +and we'll also learn how to express +mathematically uh statements like uh if + + align:start position:0% +mathematically uh statements like uh if + + + align:start position:0% +mathematically uh statements like uh if +you recall I was saying things last time + + align:start position:0% +you recall I was saying things last time + + + align:start position:0% +you recall I was saying things last time +like you know if the prize is behind + + align:start position:0% +like you know if the prize is behind + + + align:start position:0% +like you know if the prize is behind +door a what is the probability that uh + + align:start position:0% +door a what is the probability that uh + + + align:start position:0% +door a what is the probability that uh +Marilyn selects door b or or something + + align:start position:0% +Marilyn selects door b or or something + + + align:start position:0% +Marilyn selects door b or or something +like that okay so we're going to uh you + + align:start position:0% +like that okay so we're going to uh you + + + align:start position:0% +like that okay so we're going to uh you +know see you know more formally what + + align:start position:0% +know see you know more formally what + + + align:start position:0% +know see you know more formally what +these statements are are trying to + + align:start position:0% +these statements are are trying to + + + align:start position:0% +these statements are are trying to +express and how to reason about them + + align:start position:0% +express and how to reason about them + + + align:start position:0% +express and how to reason about them +okay so uh recall how we Define the + + align:start position:0% +okay so uh recall how we Define the + + + align:start position:0% +okay so uh recall how we Define the +probability of an event a so an event is + + align:start position:0% +probability of an event a so an event is + + + align:start position:0% +probability of an event a so an event is +just a set of + + align:start position:0% +just a set of + + + align:start position:0% +just a set of +outcomes uh our probability function PR + + align:start position:0% +outcomes uh our probability function PR + + + align:start position:0% +outcomes uh our probability function PR +is a function from uh the set of + + align:start position:0% +is a function from uh the set of + + + align:start position:0% +is a function from uh the set of +outcomes the sample space uh to the + + align:start position:0% +outcomes the sample space uh to the + + + align:start position:0% +outcomes the sample space uh to the +interval 0 to 1 and we can can extend + + align:start position:0% +interval 0 to 1 and we can can extend + + + align:start position:0% +interval 0 to 1 and we can can extend +this naturally to events by saying that + + align:start position:0% +this naturally to events by saying that + + + align:start position:0% +this naturally to events by saying that +the probability of an event is just the + + align:start position:0% +the probability of an event is just the + + + align:start position:0% +the probability of an event is just the +sum of the probabilities of all of the + + align:start position:0% +sum of the probabilities of all of the + + + align:start position:0% +sum of the probabilities of all of the +outcomes in that event + + align:start position:0% +outcomes in that event + + + align:start position:0% +outcomes in that event +okay so an immediate consequence of this + + align:start position:0% +okay so an immediate consequence of this + + + align:start position:0% +okay so an immediate consequence of this +definition or several immediate + + align:start position:0% +definition or several immediate + + + align:start position:0% +definition or several immediate +consequences I suppose are the following + + align:start position:0% +consequences I suppose are the following + + + align:start position:0% +consequences I suppose are the following +so first we have the sum + + align:start position:0% + + + + align:start position:0% + +rule so if we have two events uh A and B + + align:start position:0% +rule so if we have two events uh A and B + + + align:start position:0% +rule so if we have two events uh A and B +and they're disjoint so A and B are + + align:start position:0% +and they're disjoint so A and B are + + + align:start position:0% +and they're disjoint so A and B are +disjoint of + + align:start position:0% + + + + align:start position:0% + +events this tells us that the + + align:start position:0% +events this tells us that the + + + align:start position:0% +events this tells us that the +probability of the Union of A and + + align:start position:0% +probability of the Union of A and + + + align:start position:0% +probability of the Union of A and +B is what what do we think that + + align:start position:0% +B is what what do we think that + + + align:start position:0% +B is what what do we think that +is any + + align:start position:0% + + + + align:start position:0% + +ideas + + align:start position:0% +ideas + + + align:start position:0% +ideas +yeah yeah the sum of the probabilities + + align:start position:0% +yeah yeah the sum of the probabilities + + + align:start position:0% +yeah yeah the sum of the probabilities +so probability of + + align:start position:0% +so probability of + + + align:start position:0% +so probability of +a plus the probability of B + + align:start position:0% + + + + align:start position:0% + +okay so very similar to what we saw with + + align:start position:0% +okay so very similar to what we saw with + + + align:start position:0% +okay so very similar to what we saw with +sets if you have two disint sets the + + align:start position:0% +sets if you have two disint sets the + + + align:start position:0% +sets if you have two disint sets the +size of their Union is the same as as + + align:start position:0% +size of their Union is the same as as + + + align:start position:0% +size of their Union is the same as as +the uh sum of the individual sizes the + + align:start position:0% +the uh sum of the individual sizes the + + + align:start position:0% +the uh sum of the individual sizes the +same thing happens with + + align:start position:0% +same thing happens with + + + align:start position:0% +same thing happens with +probability okay uh we also have the + + align:start position:0% +probability okay uh we also have the + + + align:start position:0% +probability okay uh we also have the +complement + + align:start position:0% + + + + align:start position:0% + +rule so if we have some event a what do + + align:start position:0% +rule so if we have some event a what do + + + align:start position:0% +rule so if we have some event a what do +we think the + + align:start position:0% +we think the + + + align:start position:0% +we think the +probability of the complement of a is so + + align:start position:0% +probability of the complement of a is so + + + align:start position:0% +probability of the complement of a is so +the probability that a does doesn't + + align:start position:0% + + + + align:start position:0% + +occur oh I should + + align:start position:0% +occur oh I should + + + align:start position:0% +occur oh I should +probably + + align:start position:0% + + + + align:start position:0% + +yeah what's the probability of not + + align:start position:0% +yeah what's the probability of not + + + align:start position:0% +yeah what's the probability of not +a anybody + + align:start position:0% + + + + align:start position:0% + +yeah yeah one minus the probability of + + align:start position:0% +yeah yeah one minus the probability of + + + align:start position:0% +yeah yeah one minus the probability of +a + + align:start position:0% +a + + + align:start position:0% +a +okay right because uh a and not a are + + align:start position:0% +okay right because uh a and not a are + + + align:start position:0% +okay right because uh a and not a are +disjoint and one of them must happen so + + align:start position:0% +disjoint and one of them must happen so + + + align:start position:0% +disjoint and one of them must happen so +you know with certainty uh one of a or + + align:start position:0% +you know with certainty uh one of a or + + + align:start position:0% +you know with certainty uh one of a or +not a happens so the probability of + + align:start position:0% +not a happens so the probability of + + + align:start position:0% +not a happens so the probability of +their Union is one so this kind of just + + align:start position:0% +their Union is one so this kind of just + + + align:start position:0% +their Union is one so this kind of just +follows from the sum rule + + align:start position:0% + + + + align:start position:0% + +okay what else do we + + align:start position:0% + + + + align:start position:0% + +have uh the difference + + align:start position:0% + + + + align:start position:0% + +rule okay so in this case suppose we + + align:start position:0% +rule okay so in this case suppose we + + + align:start position:0% +rule okay so in this case suppose we +have uh again two events a and B and + + align:start position:0% +have uh again two events a and B and + + + align:start position:0% +have uh again two events a and B and +this time we'd like to look at the + + align:start position:0% +this time we'd like to look at the + + + align:start position:0% +this time we'd like to look at the +difference a set minus + + align:start position:0% + + + + align:start position:0% + +B what do we think that might be in + + align:start position:0% +B what do we think that might be in + + + align:start position:0% +B what do we think that might be in +terms of the probabilities of A and + + align:start position:0% + + + + align:start position:0% + +B yeah + + align:start position:0% + + + + align:start position:0% + +exactly so the probability of + + align:start position:0% + + + + align:start position:0% + +a minus the + + align:start position:0% +a minus the + + + align:start position:0% +a minus the +probability of the + + align:start position:0% +probability of the + + + align:start position:0% +probability of the +intersection + + align:start position:0% +intersection + + + align:start position:0% +intersection +okay and why is that well a is just the + + align:start position:0% +okay and why is that well a is just the + + + align:start position:0% +okay and why is that well a is just the +disjoint Union of a minus b and a + + align:start position:0% +disjoint Union of a minus b and a + + + align:start position:0% +disjoint Union of a minus b and a +intercept B + + align:start position:0% +intercept B + + + align:start position:0% +intercept B +okay uh we also have an analog of + + align:start position:0% +okay uh we also have an analog of + + + align:start position:0% +okay uh we also have an analog of +principle of uh inclusion exclusion + + align:start position:0% + + + + align:start position:0% + +so the probability of + + align:start position:0% +so the probability of + + + align:start position:0% +so the probability of +uh a union B for more General A and B so + + align:start position:0% +uh a union B for more General A and B so + + + align:start position:0% +uh a union B for more General A and B so +you know they're not necessarily + + align:start position:0% +you know they're not necessarily + + + align:start position:0% +you know they're not necessarily +disjoint + + align:start position:0% +disjoint + + + align:start position:0% +disjoint +anymore just like we had with sets this + + align:start position:0% +anymore just like we had with sets this + + + align:start position:0% +anymore just like we had with sets this +is going to be the probability of + + align:start position:0% +is going to be the probability of + + + align:start position:0% +is going to be the probability of +a plus the probability of + + align:start position:0% +a plus the probability of + + + align:start position:0% +a plus the probability of +B minus the + + align:start position:0% +B minus the + + + align:start position:0% +B minus the +probability of the + + align:start position:0% + + + + align:start position:0% + +intersection okay + + align:start position:0% + + + + align:start position:0% + +and we have a couple of um new uh rules + + align:start position:0% +and we have a couple of um new uh rules + + + align:start position:0% +and we have a couple of um new uh rules +that don't really have analoges in in + + align:start position:0% +that don't really have analoges in in + + + align:start position:0% +that don't really have analoges in in +the case of uh uh like in the case of + + align:start position:0% +the case of uh uh like in the case of + + + align:start position:0% +the case of uh uh like in the case of +counting + + align:start position:0% +counting + + + align:start position:0% +counting +sets so first we have the union + + align:start position:0% +sets so first we have the union + + + align:start position:0% +sets so first we have the union +Bond + + align:start position:0% + + + + align:start position:0% + +oops + + align:start position:0% +oops + + + align:start position:0% +oops +so probability of a union B it's less + + align:start position:0% +so probability of a union B it's less + + + align:start position:0% +so probability of a union B it's less +than or equal to probability of + + align:start position:0% +than or equal to probability of + + + align:start position:0% +than or equal to probability of +a plus probability of b or I suppose I + + align:start position:0% +a plus probability of b or I suppose I + + + align:start position:0% +a plus probability of b or I suppose I +shouldn't say it doesn't really have an + + align:start position:0% +shouldn't say it doesn't really have an + + + align:start position:0% +shouldn't say it doesn't really have an +analog but we didn't really look at the + + align:start position:0% +analog but we didn't really look at the + + + align:start position:0% +analog but we didn't really look at the +analog + + align:start position:0% + + + + align:start position:0% + +okay and why might that be the + + align:start position:0% +okay and why might that be the + + + align:start position:0% +okay and why might that be the +case yeah oh + + align:start position:0% + + + + align:start position:0% + +yeah uh so uh the question is what's the + + align:start position:0% +yeah uh so uh the question is what's the + + + align:start position:0% +yeah uh so uh the question is what's the +difference between the sum Rule and Pi + + align:start position:0% +difference between the sum Rule and Pi + + + align:start position:0% +difference between the sum Rule and Pi +so so in the sum rule we assume that A + + align:start position:0% +so so in the sum rule we assume that A + + + align:start position:0% +so so in the sum rule we assume that A +and B are + + align:start position:0% +and B are + + + align:start position:0% +and B are +disjoint okay so if a and b are disjoint + + align:start position:0% +disjoint okay so if a and b are disjoint + + + align:start position:0% +disjoint okay so if a and b are disjoint +then their intersection is is empty so + + align:start position:0% +then their intersection is is empty so + + + align:start position:0% +then their intersection is is empty so +the intersection has zero probability so + + align:start position:0% +the intersection has zero probability so + + + align:start position:0% +the intersection has zero probability so +Pi is just a way to generalize uh the + + align:start position:0% +Pi is just a way to generalize uh the + + + align:start position:0% +Pi is just a way to generalize uh the +the sum rule okay to to the case where + + align:start position:0% +the sum rule okay to to the case where + + + align:start position:0% +the sum rule okay to to the case where +they're they're not necessarily disjoint + + align:start position:0% +they're they're not necessarily disjoint + + + align:start position:0% +they're they're not necessarily disjoint +anymore they may have a non-trivial + + align:start position:0% +anymore they may have a non-trivial + + + align:start position:0% +anymore they may have a non-trivial +intersection okay good question any + + align:start position:0% +intersection okay good question any + + + align:start position:0% +intersection okay good question any +other + + align:start position:0% + + + + align:start position:0% + +questions no okay so can anybody give a + + align:start position:0% +questions no okay so can anybody give a + + + align:start position:0% +questions no okay so can anybody give a +reason why the union bound might be + + align:start position:0% + + + + align:start position:0% + +true + + align:start position:0% + + + + align:start position:0% + +yeah yeah so the answer was the + + align:start position:0% +yeah yeah so the answer was the + + + align:start position:0% +yeah yeah so the answer was the +probability of the intersection is not + + align:start position:0% +probability of the intersection is not + + + align:start position:0% +probability of the intersection is not +negative right so uh you know if we just + + align:start position:0% +negative right so uh you know if we just + + + align:start position:0% +negative right so uh you know if we just +take PI right so this holds you know + + align:start position:0% +take PI right so this holds you know + + + align:start position:0% +take PI right so this holds you know +with + + align:start position:0% +with + + + align:start position:0% +with +equality and now if we just you know get + + align:start position:0% +equality and now if we just you know get + + + align:start position:0% +equality and now if we just you know get +rid of this negative term here we can + + align:start position:0% +rid of this negative term here we can + + + align:start position:0% +rid of this negative term here we can +only increase the uh the probability + + align:start position:0% +only increase the uh the probability + + + align:start position:0% +only increase the uh the probability +because all probabilities have to be + + align:start position:0% +because all probabilities have to be + + + align:start position:0% +because all probabilities have to be +between zero and one + + align:start position:0% +between zero and one + + + align:start position:0% +between zero and one +okay uh we also have + + align:start position:0% + + + + align:start position:0% + +monotonicity again I don't think we uh + + align:start position:0% +monotonicity again I don't think we uh + + + align:start position:0% +monotonicity again I don't think we uh +you know saw an analogue of this with + + align:start position:0% +you know saw an analogue of this with + + + align:start position:0% +you know saw an analogue of this with +sets but uh you know + + align:start position:0% +sets but uh you know + + + align:start position:0% +sets but uh you know +if a is a subset of B what do you think + + align:start position:0% +if a is a subset of B what do you think + + + align:start position:0% +if a is a subset of B what do you think +that tells us about the uh probabilities + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% + + + + align:start position:0% + +ites I'm I'm seeing some uh hand + + align:start position:0% +ites I'm I'm seeing some uh hand + + + align:start position:0% +ites I'm I'm seeing some uh hand +motions + + align:start position:0% + + + + align:start position:0% + +so as you might expect from the + + align:start position:0% + + + + align:start position:0% + +name if a is a subset of B then its + + align:start position:0% +name if a is a subset of B then its + + + align:start position:0% +name if a is a subset of B then its +probability should be smaller than the + + align:start position:0% +probability should be smaller than the + + + align:start position:0% +probability should be smaller than the +the probability of + + align:start position:0% +the probability of + + + align:start position:0% +the probability of +B + + align:start position:0% + + + + align:start position:0% + +okay so do these make uh do these make + + align:start position:0% +okay so do these make uh do these make + + + align:start position:0% +okay so do these make uh do these make +sense to everybody + + align:start position:0% + + + + align:start position:0% + +okay so just as we saw with uh with + + align:start position:0% +okay so just as we saw with uh with + + + align:start position:0% +okay so just as we saw with uh with +sets uh both the sum rule the union + + align:start position:0% +sets uh both the sum rule the union + + + align:start position:0% +sets uh both the sum rule the union +bound and uh principle of inclusion + + align:start position:0% +bound and uh principle of inclusion + + + align:start position:0% +bound and uh principle of inclusion +exclusion can all generalize to you know + + align:start position:0% +exclusion can all generalize to you know + + + align:start position:0% +exclusion can all generalize to you know +arbitrary numbers of of uh events uh or + + align:start position:0% +arbitrary numbers of of uh events uh or + + + align:start position:0% +arbitrary numbers of of uh events uh or +even you know countably many okay uh I + + align:start position:0% +even you know countably many okay uh I + + + align:start position:0% +even you know countably many okay uh I +suppose principle of inclusion exclusion + + align:start position:0% +suppose principle of inclusion exclusion + + + align:start position:0% +suppose principle of inclusion exclusion +you should probably only think about you + + align:start position:0% +you should probably only think about you + + + align:start position:0% +you should probably only think about you +know finite cases but the other two are + + align:start position:0% +know finite cases but the other two are + + + align:start position:0% +know finite cases but the other two are +you know they fairly naturally + + align:start position:0% +you know they fairly naturally + + + align:start position:0% +you know they fairly naturally +generalize to uh to countable sets of + + align:start position:0% +generalize to uh to countable sets of + + + align:start position:0% +generalize to uh to countable sets of +events okay so do these rules make sense + + align:start position:0% +events okay so do these rules make sense + + + align:start position:0% +events okay so do these rules make sense +to everybody he'll probably be using + + align:start position:0% +to everybody he'll probably be using + + + align:start position:0% +to everybody he'll probably be using +them quite a lot so uh you know make + + align:start position:0% +them quite a lot so uh you know make + + + align:start position:0% +them quite a lot so uh you know make +sure you're familiar with + + align:start position:0% + + + + align:start position:0% + +them any + + align:start position:0% + + + + align:start position:0% + +questions + + align:start position:0% +questions + + + align:start position:0% +questions +okay so in that case let us move on to + + align:start position:0% +okay so in that case let us move on to + + + align:start position:0% +okay so in that case let us move on to +the main topic of today's lecture + + align:start position:0% +the main topic of today's lecture + + + align:start position:0% +the main topic of today's lecture +conditional + + align:start position:0% + + + + align:start position:0% + +probability okay so if you recall on + + align:start position:0% +probability okay so if you recall on + + + align:start position:0% +probability okay so if you recall on +Tuesday when we were talking about the + + align:start position:0% +Tuesday when we were talking about the + + + align:start position:0% +Tuesday when we were talking about the +Monty Hall problem when we were drawing + + align:start position:0% +Monty Hall problem when we were drawing + + + align:start position:0% +Monty Hall problem when we were drawing +a tree diagram right um we were making + + align:start position:0% +a tree diagram right um we were making + + + align:start position:0% +a tree diagram right um we were making +statements such as you know if the car + + align:start position:0% +statements such as you know if the car + + + align:start position:0% +statements such as you know if the car +is behind door one what's the + + align:start position:0% +is behind door one what's the + + + align:start position:0% +is behind door one what's the +probability that we picked door two or I + + align:start position:0% +probability that we picked door two or I + + + align:start position:0% +probability that we picked door two or I +guess it was you purple gold and green + + align:start position:0% +guess it was you purple gold and green + + + align:start position:0% +guess it was you purple gold and green +uh purple gold silver silver + + align:start position:0% +uh purple gold silver silver + + + align:start position:0% +uh purple gold silver silver +yeah uh so how do we express this + + align:start position:0% +yeah uh so how do we express this + + + align:start position:0% +yeah uh so how do we express this +mathematically uh so that's where + + align:start position:0% +mathematically uh so that's where + + + align:start position:0% +mathematically uh so that's where +conditional probability comes + + align:start position:0% +conditional probability comes + + + align:start position:0% +conditional probability comes +in we're going to make use of the + + align:start position:0% +in we're going to make use of the + + + align:start position:0% +in we're going to make use of the +following definition okay so if we have + + align:start position:0% +following definition okay so if we have + + + align:start position:0% +following definition okay so if we have +two + + align:start position:0% + + + + align:start position:0% + +events A and + + align:start position:0% +events A and + + + align:start position:0% +events A and +B uh we Define the conditional + + align:start position:0% +B uh we Define the conditional + + + align:start position:0% +B uh we Define the conditional +probability + + align:start position:0% + + + + align:start position:0% + +of a given + + align:start position:0% + + + + align:start position:0% + +B + + align:start position:0% +B + + + align:start position:0% +B +okay uh which we denote as the + + align:start position:0% + + + + align:start position:0% + +following so we' say uh you know a + + align:start position:0% +following so we' say uh you know a + + + align:start position:0% +following so we' say uh you know a +conditioned on B right we denote that + + align:start position:0% +conditioned on B right we denote that + + + align:start position:0% +conditioned on B right we denote that +with a vertical + + align:start position:0% +with a vertical + + + align:start position:0% +with a vertical +bar we Define this to be + + align:start position:0% +bar we Define this to be + + + align:start position:0% +bar we Define this to be +the + + align:start position:0% +the + + + align:start position:0% +the +probability of a intersect + + align:start position:0% +probability of a intersect + + + align:start position:0% +probability of a intersect +B divided by the probability of + + align:start position:0% + + + + align:start position:0% + +B + + align:start position:0% + + + + align:start position:0% + +okay so intuitively you can kind of + + align:start position:0% +okay so intuitively you can kind of + + + align:start position:0% +okay so intuitively you can kind of +think of it a little bit as uh you know + + align:start position:0% +think of it a little bit as uh you know + + + align:start position:0% +think of it a little bit as uh you know +we're trying to scale our probability + + align:start position:0% +we're trying to scale our probability + + + align:start position:0% +we're trying to scale our probability +space so that you know B becomes our + + align:start position:0% +space so that you know B becomes our + + + align:start position:0% +space so that you know B becomes our +entire entire sample space okay so we + + align:start position:0% +entire entire sample space okay so we + + + align:start position:0% +entire entire sample space okay so we +kind of want to divide out this this + + align:start position:0% +kind of want to divide out this this + + + align:start position:0% +kind of want to divide out this this +probability of B uh so that you know we + + align:start position:0% +probability of B uh so that you know we + + + align:start position:0% +probability of B uh so that you know we +still get a a probability space all of + + align:start position:0% +still get a a probability space all of + + + align:start position:0% +still get a a probability space all of +the probabilities sum to one okay does + + align:start position:0% +the probabilities sum to one okay does + + + align:start position:0% +the probabilities sum to one okay does +that kind of make sense to + + align:start position:0% +that kind of make sense to + + + align:start position:0% +that kind of make sense to +everybody and then you know the analog + + align:start position:0% +everybody and then you know the analog + + + align:start position:0% +everybody and then you know the analog +of a right we're you know only looking + + align:start position:0% +of a right we're you know only looking + + + align:start position:0% +of a right we're you know only looking +at everything that that's already within + + align:start position:0% +at everything that that's already within + + + align:start position:0% +at everything that that's already within +B so we're looking at the intersection + + align:start position:0% +B so we're looking at the intersection + + + align:start position:0% +B so we're looking at the intersection +of A and + + align:start position:0% +of A and + + + align:start position:0% +of A and +B + + align:start position:0% + + + + align:start position:0% + +okay now if we rewrite this we can get a + + align:start position:0% +okay now if we rewrite this we can get a + + + align:start position:0% +okay now if we rewrite this we can get a +product rule + + align:start position:0% + + + + align:start position:0% + +right so if we want to know the + + align:start position:0% +right so if we want to know the + + + align:start position:0% +right so if we want to know the +probability of a intercept B we can kind + + align:start position:0% +probability of a intercept B we can kind + + + align:start position:0% +probability of a intercept B we can kind +of just move this probability of B over + + align:start position:0% +of just move this probability of B over + + + align:start position:0% +of just move this probability of B over +to the other + + align:start position:0% +to the other + + + align:start position:0% +to the other +side and we end up with probability of a + + align:start position:0% +side and we end up with probability of a + + + align:start position:0% +side and we end up with probability of a +intersect + + align:start position:0% +intersect + + + align:start position:0% +intersect +b + + align:start position:0% +b + + + align:start position:0% +b +equals probability of a given + + align:start position:0% +equals probability of a given + + + align:start position:0% +equals probability of a given +B times the + + align:start position:0% +B times the + + + align:start position:0% +B times the +probability of B + + align:start position:0% + + + + align:start position:0% + +okay and as you might expect you can + + align:start position:0% +okay and as you might expect you can + + + align:start position:0% +okay and as you might expect you can +extend this to multiple + + align:start position:0% +extend this to multiple + + + align:start position:0% +extend this to multiple +events or I guess this is already kind + + align:start position:0% +events or I guess this is already kind + + + align:start position:0% +events or I guess this is already kind +of multiple events you can extend it to + + align:start position:0% +of multiple events you can extend it to + + + align:start position:0% +of multiple events you can extend it to +more than two + + align:start position:0% +more than two + + + align:start position:0% +more than two +events so you can also have + + align:start position:0% +events so you can also have + + + align:start position:0% +events so you can also have +EG the probability of a intercept B + + align:start position:0% +EG the probability of a intercept B + + + align:start position:0% +EG the probability of a intercept B +intercept + + align:start position:0% +intercept + + + align:start position:0% +intercept +C + + align:start position:0% +C + + + align:start position:0% +C +equals + + align:start position:0% +equals + + + align:start position:0% +equals +probability of a given being + + align:start position:0% +probability of a given being + + + align:start position:0% +probability of a given being +T times the + + align:start position:0% +T times the + + + align:start position:0% +T times the +probability of B uh or maybe I should + + align:start position:0% +probability of B uh or maybe I should + + + align:start position:0% +probability of B uh or maybe I should +write this out more + + align:start position:0% +write this out more + + + align:start position:0% +write this out more +explicitly B intercept C okay and then + + align:start position:0% +explicitly B intercept C okay and then + + + align:start position:0% +explicitly B intercept C okay and then +if we apply our uh apply our binary + + align:start position:0% +if we apply our uh apply our binary + + + align:start position:0% +if we apply our uh apply our binary +product rule again we can kind of expand + + align:start position:0% +product rule again we can kind of expand + + + align:start position:0% +product rule again we can kind of expand +out that uh this + + align:start position:0% +out that uh this + + + align:start position:0% +out that uh this +term as the probability of a given B and + + align:start position:0% +term as the probability of a given B and + + + align:start position:0% +term as the probability of a given B and +C probability of + + align:start position:0% +C probability of + + + align:start position:0% +C probability of +B given + + align:start position:0% +B given + + + align:start position:0% +B given +C + + align:start position:0% +C + + + align:start position:0% +C +probability of + + align:start position:0% + + + + align:start position:0% + +C + + align:start position:0% +C + + + align:start position:0% +C +okay so that's basically what we were + + align:start position:0% +okay so that's basically what we were + + + align:start position:0% +okay so that's basically what we were +doing on Tuesday you know written out + + align:start position:0% +doing on Tuesday you know written out + + + align:start position:0% +doing on Tuesday you know written out +more formally right so + + align:start position:0% +more formally right so + + + align:start position:0% +more formally right so +uh like probability of C corresponds to + + align:start position:0% +uh like probability of C corresponds to + + + align:start position:0% +uh like probability of C corresponds to +you know what is the first Edge we chose + + align:start position:0% +you know what is the first Edge we chose + + + align:start position:0% +you know what is the first Edge we chose +you know the the first Edge going away + + align:start position:0% +you know the the first Edge going away + + + align:start position:0% +you know the the first Edge going away +from the root okay and then conditioned + + align:start position:0% +from the root okay and then conditioned + + + align:start position:0% +from the root okay and then conditioned +on reaching a particular vertex like + + align:start position:0% +on reaching a particular vertex like + + + align:start position:0% +on reaching a particular vertex like +conditioned on you know Monty hiding the + + align:start position:0% +conditioned on you know Monty hiding the + + + align:start position:0% +conditioned on you know Monty hiding the +prize in the gold + + align:start position:0% +prize in the gold + + + align:start position:0% +prize in the gold +box you know what's the probability that + + align:start position:0% +box you know what's the probability that + + + align:start position:0% +box you know what's the probability that +Marilyn chooses the silver one okay so + + align:start position:0% +Marilyn chooses the silver one okay so + + + align:start position:0% +Marilyn chooses the silver one okay so +that's the conditional probability of + + align:start position:0% +that's the conditional probability of + + + align:start position:0% +that's the conditional probability of +choosing the Silver Box conditioned on + + align:start position:0% +choosing the Silver Box conditioned on + + + align:start position:0% +choosing the Silver Box conditioned on +the the prize being in the gold box okay + + align:start position:0% +the the prize being in the gold box okay + + + align:start position:0% +the the prize being in the gold box okay +and then you know as you continue along + + align:start position:0% +and then you know as you continue along + + + align:start position:0% +and then you know as you continue along +the uh uh along the path to a + + align:start position:0% +the uh uh along the path to a + + + align:start position:0% +the uh uh along the path to a +leaf uh all of the edge probabilities + + align:start position:0% +leaf uh all of the edge probabilities + + + align:start position:0% +leaf uh all of the edge probabilities +that you're looking at are secret like + + align:start position:0% +that you're looking at are secret like + + + align:start position:0% +that you're looking at are secret like +they were secretly just you know basic + + align:start position:0% +they were secretly just you know basic + + + align:start position:0% +they were secretly just you know basic +additional probabilities okay does that + + align:start position:0% +additional probabilities okay does that + + + align:start position:0% +additional probabilities okay does that +make sense to + + align:start position:0% + + + + align:start position:0% + +everybody any + + align:start position:0% + + + + align:start position:0% + +questions + + align:start position:0% +questions + + + align:start position:0% +questions +okay so another extension of this that + + align:start position:0% +okay so another extension of this that + + + align:start position:0% +okay so another extension of this that +you may find + + align:start position:0% + + + + align:start position:0% + +useful is the + + align:start position:0% + + + + align:start position:0% + +following a intersect B + + align:start position:0% +following a intersect B + + + align:start position:0% +following a intersect B +given + + align:start position:0% +given + + + align:start position:0% +given +C is going to + + align:start position:0% +C is going to + + + align:start position:0% +C is going to +be + + align:start position:0% +be + + + align:start position:0% +be +probability of a given B intercept + + align:start position:0% +probability of a given B intercept + + + align:start position:0% +probability of a given B intercept +C + + align:start position:0% +C + + + align:start position:0% +C +probability of B given + + align:start position:0% + + + + align:start position:0% + +C + + align:start position:0% +C + + + align:start position:0% +C +okay so can anybody see why that might + + align:start position:0% +okay so can anybody see why that might + + + align:start position:0% +okay so can anybody see why that might +be the case + + align:start position:0% + + + + align:start position:0% + +well first maybe we should look at you + + align:start position:0% +well first maybe we should look at you + + + align:start position:0% +well first maybe we should look at you +know what exactly is it saying okay so + + align:start position:0% +know what exactly is it saying okay so + + + align:start position:0% +know what exactly is it saying okay so +if you kind + + align:start position:0% +if you kind + + + align:start position:0% +if you kind +of squint a little bit and get rid of + + align:start position:0% +of squint a little bit and get rid of + + + align:start position:0% +of squint a little bit and get rid of +the C's + + align:start position:0% + + + + align:start position:0% + +right it kind of looks a little + + align:start position:0% +right it kind of looks a little + + + align:start position:0% +right it kind of looks a little +bit like the product rule right a + + align:start position:0% +bit like the product rule right a + + + align:start position:0% +bit like the product rule right a +intercept B is + + align:start position:0% +intercept B is + + + align:start position:0% +intercept B is +probability a given + + align:start position:0% +probability a given + + + align:start position:0% +probability a given +B times probability of B + + align:start position:0% +B times probability of B + + + align:start position:0% +B times probability of B +okay it it looks kind of like that right + + align:start position:0% +okay it it looks kind of like that right + + + align:start position:0% +okay it it looks kind of like that right +but we've added a bunch of C's + + align:start position:0% +but we've added a bunch of C's + + + align:start position:0% +but we've added a bunch of C's +everywhere so basically what we're + + align:start position:0% +everywhere so basically what we're + + + align:start position:0% +everywhere so basically what we're +saying here is this is the product rule + + align:start position:0% +saying here is this is the product rule + + + align:start position:0% +saying here is this is the product rule +in the probability space where we're you + + align:start position:0% +in the probability space where we're you + + + align:start position:0% +in the probability space where we're you +know assuming C like it's it's the + + align:start position:0% +know assuming C like it's it's the + + + align:start position:0% +know assuming C like it's it's the +product rule conditioned on + + align:start position:0% +product rule conditioned on + + + align:start position:0% +product rule conditioned on +C okay does that make sense to + + align:start position:0% + + + + align:start position:0% + +everybody and we can you know obtain it + + align:start position:0% +everybody and we can you know obtain it + + + align:start position:0% +everybody and we can you know obtain it +from the from the previous line just by + + align:start position:0% +from the from the previous line just by + + + align:start position:0% +from the from the previous line just by +dividing out by the probability of C + + align:start position:0% + + + + align:start position:0% + +okay do people have questions are we + + align:start position:0% +okay do people have questions are we + + + align:start position:0% +okay do people have questions are we +happy to move on to some examples yeah + + align:start position:0% + + + + align:start position:0% + +sorry uh okay so the question was are we + + align:start position:0% +sorry uh okay so the question was are we + + + align:start position:0% +sorry uh okay so the question was are we +talking about sets or events uh yes uh + + align:start position:0% +talking about sets or events uh yes uh + + + align:start position:0% +talking about sets or events uh yes uh +so remember that uh events are defined + + align:start position:0% +so remember that uh events are defined + + + align:start position:0% +so remember that uh events are defined +to be sets of outcomes right so uh you + + align:start position:0% +to be sets of outcomes right so uh you + + + align:start position:0% +to be sets of outcomes right so uh you +know we're talking about events but you + + align:start position:0% +know we're talking about events but you + + + align:start position:0% +know we're talking about events but you +know events are sets and we can treat + + align:start position:0% +know events are sets and we can treat + + + align:start position:0% +know events are sets and we can treat +them as such so that's why we're using + + align:start position:0% +them as such so that's why we're using + + + align:start position:0% +them as such so that's why we're using +uh lots of notation here that you would + + align:start position:0% +uh lots of notation here that you would + + + align:start position:0% +uh lots of notation here that you would +typically associate with sets like Union + + align:start position:0% +typically associate with sets like Union + + + align:start position:0% +typically associate with sets like Union +intersection + + align:start position:0% + + + + align:start position:0% + +Etc okay any other questions oh yeah + + align:start position:0% + + + + align:start position:0% + +ah uh so these are not nodes in the tree + + align:start position:0% +ah uh so these are not nodes in the tree + + + align:start position:0% +ah uh so these are not nodes in the tree +um some of uh sorry question was if we + + align:start position:0% +um some of uh sorry question was if we + + + align:start position:0% +um some of uh sorry question was if we +have an event that's like a union B + + align:start position:0% +have an event that's like a union B + + + align:start position:0% +have an event that's like a union B +Union C or something uh are these + + align:start position:0% +Union C or something uh are these + + + align:start position:0% +Union C or something uh are these +General sets or are they nodes in in the + + align:start position:0% +General sets or are they nodes in in the + + + align:start position:0% +General sets or are they nodes in in the +tree um that is a good observation some + + align:start position:0% +tree um that is a good observation some + + + align:start position:0% +tree um that is a good observation some +of the nodes in the tree kind of + + align:start position:0% +of the nodes in the tree kind of + + + align:start position:0% +of the nodes in the tree kind of +naturally correspond to events right + + align:start position:0% +naturally correspond to events right + + + align:start position:0% +naturally correspond to events right +like uh you know if we draw out our tree + + align:start position:0% +like uh you know if we draw out our tree + + + align:start position:0% +like uh you know if we draw out our tree +diagram this node here fairly naturally + + align:start position:0% +diagram this node here fairly naturally + + + align:start position:0% +diagram this node here fairly naturally +corresponds to this set of events like + + align:start position:0% +corresponds to this set of events like + + + align:start position:0% +corresponds to this set of events like +or sorry this set of outcomes those + + align:start position:0% +or sorry this set of outcomes those + + + align:start position:0% +or sorry this set of outcomes those +those two uh leaves in its sub tree uh + + align:start position:0% +those two uh leaves in its sub tree uh + + + align:start position:0% +those two uh leaves in its sub tree uh +but not every event necessarily + + align:start position:0% +but not every event necessarily + + + align:start position:0% +but not every event necessarily +corresponds to an internal node of the + + align:start position:0% +corresponds to an internal node of the + + + align:start position:0% +corresponds to an internal node of the +tree like that like for instance you + + align:start position:0% +tree like that like for instance you + + + align:start position:0% +tree like that like for instance you +could + + align:start position:0% +could + + + align:start position:0% +could +have these two uh outcomes + + align:start position:0% +have these two uh outcomes + + + align:start position:0% +have these two uh outcomes +right uh if you you know consider the + + align:start position:0% +right uh if you you know consider the + + + align:start position:0% +right uh if you you know consider the +set of those two outcomes that's still a + + align:start position:0% +set of those two outcomes that's still a + + + align:start position:0% +set of those two outcomes that's still a +valid event but it doesn't really + + align:start position:0% +valid event but it doesn't really + + + align:start position:0% +valid event but it doesn't really +naturally correspond to a a a tree Noe + + align:start position:0% +naturally correspond to a a a tree Noe + + + align:start position:0% +naturally correspond to a a a tree Noe +in the same way + + align:start position:0% +in the same way + + + align:start position:0% +in the same way +does that make + + align:start position:0% + + + + align:start position:0% + +sense oh that that is quite + + align:start position:0% + + + + align:start position:0% + +possible okay um so asking about the + + align:start position:0% +possible okay um so asking about the + + + align:start position:0% +possible okay um so asking about the +conditional probabilities as they appear + + align:start position:0% +conditional probabilities as they appear + + + align:start position:0% +conditional probabilities as they appear +in the + + align:start position:0% +in the + + + align:start position:0% +in the +tree uh + + align:start position:0% + + + + align:start position:0% + +yes oh I see okay uh so I guess the the + + align:start position:0% +yes oh I see okay uh so I guess the the + + + align:start position:0% +yes oh I see okay uh so I guess the the +way that I like to think about uh a + + align:start position:0% +way that I like to think about uh a + + + align:start position:0% +way that I like to think about uh a +given B um it is an event in a different + + align:start position:0% +given B um it is an event in a different + + + align:start position:0% +given B um it is an event in a different +probability + + align:start position:0% +probability + + + align:start position:0% +probability +space so you can kind of think of uh you + + align:start position:0% +space so you can kind of think of uh you + + + align:start position:0% +space so you can kind of think of uh you +know if you limit uh the scope rather + + align:start position:0% +know if you limit uh the scope rather + + + align:start position:0% +know if you limit uh the scope rather +rather than you know talking about your + + align:start position:0% +rather than you know talking about your + + + align:start position:0% +rather than you know talking about your +entire sample space s if you limit the + + align:start position:0% +entire sample space s if you limit the + + + align:start position:0% +entire sample space s if you limit the +the scope to just C so you like scale + + align:start position:0% +the scope to just C so you like scale + + + align:start position:0% +the scope to just C so you like scale +all of the probabilities down by by the + + align:start position:0% +all of the probabilities down by by the + + + align:start position:0% +all of the probabilities down by by the +probability of C you you end up with a + + align:start position:0% +probability of C you you end up with a + + + align:start position:0% +probability of C you you end up with a +different probability space so now the + + align:start position:0% +different probability space so now the + + + align:start position:0% +different probability space so now the +probability of or sorry the event you + + align:start position:0% +probability of or sorry the event you + + + align:start position:0% +probability of or sorry the event you +know be given C is an event in that + + align:start position:0% +know be given C is an event in that + + + align:start position:0% +know be given C is an event in that +probability space does that make + + align:start position:0% +probability space does that make + + + align:start position:0% +probability space does that make +sense okay yeah + + align:start position:0% +sense okay yeah + + + align:start position:0% +sense okay yeah +sorry thank you for the clarification + + align:start position:0% + + + + align:start position:0% + +okay so why don't we move on to some + + align:start position:0% +okay so why don't we move on to some + + + align:start position:0% +okay so why don't we move on to some +examples then if uh if this makes you + + align:start position:0% +examples then if uh if this makes you + + + align:start position:0% +examples then if uh if this makes you +know reasonable amount of sense + + align:start position:0% +know reasonable amount of sense + + + align:start position:0% +know reasonable amount of sense +hopefully it'll make more sense after + + align:start position:0% +hopefully it'll make more sense after + + + align:start position:0% +hopefully it'll make more sense after +examples okay so uh you know suppose Ash + + align:start position:0% +examples okay so uh you know suppose Ash + + + align:start position:0% +examples okay so uh you know suppose Ash +and Gary are having a bunch of Pokemon + + align:start position:0% +and Gary are having a bunch of Pokemon + + + align:start position:0% +and Gary are having a bunch of Pokemon +battles against each other and you know + + align:start position:0% +battles against each other and you know + + + align:start position:0% +battles against each other and you know +they're doing like a tournament the the + + align:start position:0% +they're doing like a tournament the the + + + align:start position:0% +they're doing like a tournament the the +first to win two battles uh wins the uh + + align:start position:0% +first to win two battles uh wins the uh + + + align:start position:0% +first to win two battles uh wins the uh +the or I guess the series the first to + + align:start position:0% +the or I guess the series the first to + + + align:start position:0% +the or I guess the series the first to +win two battles wins the series okay and + + align:start position:0% +win two battles wins the series okay and + + + align:start position:0% +win two battles wins the series okay and +uh you know the the probability is of + + align:start position:0% +uh you know the the probability is of + + + align:start position:0% +uh you know the the probability is of +Victor are not you know entirely uniform + + align:start position:0% +Victor are not you know entirely uniform + + + align:start position:0% +Victor are not you know entirely uniform +so for the first match you know maybe + + align:start position:0% +so for the first match you know maybe + + + align:start position:0% +so for the first match you know maybe +it's a toss up okay Ash wins with + + align:start position:0% +it's a toss up okay Ash wins with + + + align:start position:0% +it's a toss up okay Ash wins with +probability one2 Gary wins with + + align:start position:0% +probability one2 Gary wins with + + + align:start position:0% +probability one2 Gary wins with +probability one half okay uh but after + + align:start position:0% +probability one half okay uh but after + + + align:start position:0% +probability one half okay uh but after +the first battle there's kind of an + + align:start position:0% +the first battle there's kind of an + + + align:start position:0% +the first battle there's kind of an +advantage to whoever won the last battle + + align:start position:0% +advantage to whoever won the last battle + + + align:start position:0% +advantage to whoever won the last battle +like you know their their their morale + + align:start position:0% +like you know their their their morale + + + align:start position:0% +like you know their their their morale +is high or something they they do better + + align:start position:0% +is high or something they they do better + + + align:start position:0% +is high or something they they do better +so they now have probability of 2/3 uh + + align:start position:0% +so they now have probability of 2/3 uh + + + align:start position:0% +so they now have probability of 2/3 uh +of winning the next battle + + align:start position:0% +of winning the next battle + + + align:start position:0% +of winning the next battle +okay and there aren't there aren't any + + align:start position:0% +okay and there aren't there aren't any + + + align:start position:0% +okay and there aren't there aren't any +draws uh they're bitter Rivals they will + + align:start position:0% +draws uh they're bitter Rivals they will + + + align:start position:0% +draws uh they're bitter Rivals they will +fight to the death + + align:start position:0% +fight to the death + + + align:start position:0% +fight to the death +um + + align:start position:0% +um + + + align:start position:0% +um +okay so let's define a couple of events + + align:start position:0% +okay so let's define a couple of events + + + align:start position:0% +okay so let's define a couple of events +we'll say that a is the + + align:start position:0% + + + + align:start position:0% + +event Ash + + align:start position:0% +event Ash + + + align:start position:0% +event Ash +wins oops the + + align:start position:0% + + + + align:start position:0% + +series and + + align:start position:0% +series and + + + align:start position:0% +series and +B is the event uh Ash wins + + align:start position:0% +B is the event uh Ash wins + + + align:start position:0% +B is the event uh Ash wins +the first + + align:start position:0% + + + + align:start position:0% + +battal + + align:start position:0% +battal + + + align:start position:0% +battal +okay so now we can ask for the + + align:start position:0% + + + + align:start position:0% + +probability of a given + + align:start position:0% + + + + align:start position:0% + +B + + align:start position:0% +B + + + align:start position:0% +B +okay so does does the problem setup make + + align:start position:0% +okay so does does the problem setup make + + + align:start position:0% +okay so does does the problem setup make +sense yeah okay so how could we compute + + align:start position:0% + + + + align:start position:0% + +this any ideas where do we want to + + align:start position:0% + + + + align:start position:0% + +start should we just throw some numbers + + align:start position:0% +start should we just throw some numbers + + + align:start position:0% +start should we just throw some numbers +out there oh + + align:start position:0% +out there oh + + + align:start position:0% +out there oh +yeah yeah let's draw a tree diagram nice + + align:start position:0% +yeah yeah let's draw a tree diagram nice + + + align:start position:0% +yeah yeah let's draw a tree diagram nice +one okay + + align:start position:0% +one okay + + + align:start position:0% +one okay +so drawing a tree diagram what's the + + align:start position:0% +so drawing a tree diagram what's the + + + align:start position:0% +so drawing a tree diagram what's the +first you know random thing that happens + + align:start position:0% +first you know random thing that happens + + + align:start position:0% +first you know random thing that happens +what's the what's the first source of + + align:start position:0% + + + + align:start position:0% + +Randomness + + align:start position:0% + + + + align:start position:0% + +yeah yeah so F could win or lose the + + align:start position:0% +yeah yeah so F could win or lose the + + + align:start position:0% +yeah yeah so F could win or lose the +first battle so we can actually label + + align:start position:0% +first battle so we can actually label + + + align:start position:0% +first battle so we can actually label +these as + + align:start position:0% +these as + + + align:start position:0% +these as +B and not B + + align:start position:0% +B and not B + + + align:start position:0% +B and not B +okay what's the next random thing that + + align:start position:0% +okay what's the next random thing that + + + align:start position:0% +okay what's the next random thing that +could + + align:start position:0% + + + + align:start position:0% + +happen + + align:start position:0% + + + + align:start position:0% + +yeah yeah that's right so actually maybe + + align:start position:0% +yeah yeah that's right so actually maybe + + + align:start position:0% +yeah yeah that's right so actually maybe +it's better to call these just W and L + + align:start position:0% +it's better to call these just W and L + + + align:start position:0% +it's better to call these just W and L +so we can use the same thing + + align:start position:0% + + + + align:start position:0% + +everywhere so win lose win lose + + align:start position:0% +everywhere so win lose win lose + + + align:start position:0% +everywhere so win lose win lose +regardless of uh whether he wins or + + align:start position:0% +regardless of uh whether he wins or + + + align:start position:0% +regardless of uh whether he wins or +loses the first battle you can still + + align:start position:0% +loses the first battle you can still + + + align:start position:0% +loses the first battle you can still +either win or lose the second one Okay + + align:start position:0% +either win or lose the second one Okay + + + align:start position:0% +either win or lose the second one Okay +now what's the third layer going to + + align:start position:0% + + + + align:start position:0% + +be + + align:start position:0% +be + + + align:start position:0% +be +exactly yeah exactly okay so if he's one + + align:start position:0% +exactly yeah exactly okay so if he's one + + + align:start position:0% +exactly yeah exactly okay so if he's one +two or lost two those are just leaves + + align:start position:0% +two or lost two those are just leaves + + + align:start position:0% +two or lost two those are just leaves +now we don't do anything more the series + + align:start position:0% +now we don't do anything more the series + + + align:start position:0% +now we don't do anything more the series +is over okay but if he's won one and + + align:start position:0% +is over okay but if he's won one and + + + align:start position:0% +is over okay but if he's won one and +lost one in either order we can now + + align:start position:0% +lost one in either order we can now + + + align:start position:0% +lost one in either order we can now +split + + align:start position:0% +split + + + align:start position:0% +split +again oops that's a little bit long but + + align:start position:0% +again oops that's a little bit long but + + + align:start position:0% +again oops that's a little bit long but +oh well WL + + align:start position:0% +oh well WL + + + align:start position:0% +oh well WL +WL + + align:start position:0% +WL + + + align:start position:0% +WL +okay so now what are our outcomes again + + align:start position:0% +okay so now what are our outcomes again + + + align:start position:0% +okay so now what are our outcomes again +let's look at the uh uh paths from from + + align:start position:0% +let's look at the uh uh paths from from + + + align:start position:0% +let's look at the uh uh paths from from +root to leaves and just you know label + + align:start position:0% +root to leaves and just you know label + + + align:start position:0% +root to leaves and just you know label +with a uh a string of edge labels so + + align:start position:0% +with a uh a string of edge labels so + + + align:start position:0% +with a uh a string of edge labels so +this is going to be W comma w w l + + align:start position:0% +this is going to be W comma w w l + + + align:start position:0% +this is going to be W comma w w l +w w l + + align:start position:0% +w w l + + + align:start position:0% +w w l +l l w w l w l and l + + align:start position:0% + + + + align:start position:0% + +l + + align:start position:0% +l + + + align:start position:0% +l +okay now what are the probabilities on + + align:start position:0% +okay now what are the probabilities on + + + align:start position:0% +okay now what are the probabilities on +each of the edges + + align:start position:0% + + + + align:start position:0% + +so in the first layer what's the + + align:start position:0% +so in the first layer what's the + + + align:start position:0% +so in the first layer what's the +probability that Ash wins the first + + align:start position:0% +probability that Ash wins the first + + + align:start position:0% +probability that Ash wins the first +game first match + + align:start position:0% +game first match + + + align:start position:0% +game first match +yeah2 so each of these say probability + + align:start position:0% + + + + align:start position:0% + +one2 okay now the second layer we said + + align:start position:0% +one2 okay now the second layer we said + + + align:start position:0% +one2 okay now the second layer we said +are now conditional probabilities so + + align:start position:0% +are now conditional probabilities so + + + align:start position:0% +are now conditional probabilities so +conditioned on winning the first match + + align:start position:0% +conditioned on winning the first match + + + align:start position:0% +conditioned on winning the first match +what's the probability of winning the + + align:start position:0% +what's the probability of winning the + + + align:start position:0% +what's the probability of winning the +second + + align:start position:0% +second + + + align:start position:0% +second +match what's the probability on this + + align:start position:0% +match what's the probability on this + + + align:start position:0% +match what's the probability on this +edge here + + align:start position:0% + + + + align:start position:0% + +do we + + align:start position:0% +do we + + + align:start position:0% +do we +remember 2/3 + + align:start position:0% + + + + align:start position:0% + +yeah and so the other branch is going to + + align:start position:0% +yeah and so the other branch is going to + + + align:start position:0% +yeah and so the other branch is going to +be the complement of that so + + align:start position:0% +be the complement of that so + + + align:start position:0% +be the complement of that so +1/3 okay and then for the bottom Branch + + align:start position:0% +1/3 okay and then for the bottom Branch + + + align:start position:0% +1/3 okay and then for the bottom Branch +it's going to be exactly the opposite + + align:start position:0% +it's going to be exactly the opposite + + + align:start position:0% +it's going to be exactly the opposite +okay it's going to be one3 chance of + + align:start position:0% +okay it's going to be one3 chance of + + + align:start position:0% +okay it's going to be one3 chance of +winning 2/3 chance of + + align:start position:0% + + + + align:start position:0% + +losing okay + + align:start position:0% +losing okay + + + align:start position:0% +losing okay +now conditioned on winning the first + + align:start position:0% +now conditioned on winning the first + + + align:start position:0% +now conditioned on winning the first +match and losing the second match what's + + align:start position:0% +match and losing the second match what's + + + align:start position:0% +match and losing the second match what's +the probability of winning the + + align:start position:0% + + + + align:start position:0% + +third + + align:start position:0% +third + + + align:start position:0% +third +yeah one3 + + align:start position:0% +yeah one3 + + + align:start position:0% +yeah one3 +yeah so 1/3 win 2/3 loss and uh this + + align:start position:0% +yeah so 1/3 win 2/3 loss and uh this + + + align:start position:0% +yeah so 1/3 win 2/3 loss and uh this +will be uh exactly the opposite so 2/3 + + align:start position:0% +will be uh exactly the opposite so 2/3 + + + align:start position:0% +will be uh exactly the opposite so 2/3 +win 1/3 loss + + align:start position:0% +win 1/3 loss + + + align:start position:0% +win 1/3 loss +okay so now we can assign probabilities + + align:start position:0% +okay so now we can assign probabilities + + + align:start position:0% +okay so now we can assign probabilities +to all of the outcomes + + align:start position:0% +to all of the outcomes + + + align:start position:0% +to all of the outcomes +okay what's the probability of winning + + align:start position:0% + + + + align:start position:0% + +twice how do we compute these + + align:start position:0% + + + + align:start position:0% + +probabilities anyone + + align:start position:0% + + + + align:start position:0% + +yeah uh oh so that this was uh just you + + align:start position:0% +yeah uh oh so that this was uh just you + + + align:start position:0% +yeah uh oh so that this was uh just you +know what we assumed in the problem + + align:start position:0% +know what we assumed in the problem + + + align:start position:0% +know what we assumed in the problem +right + + align:start position:0% +right + + + align:start position:0% +right +if uh if it's not the first game uh you + + align:start position:0% +if uh if it's not the first game uh you + + + align:start position:0% +if uh if it's not the first game uh you +win with probability 2/3 if you won the + + align:start position:0% +win with probability 2/3 if you won the + + + align:start position:0% +win with probability 2/3 if you won the +last game or with probability 1/3 if you + + align:start position:0% +last game or with probability 1/3 if you + + + align:start position:0% +last game or with probability 1/3 if you +lost the last + + align:start position:0% + + + + align:start position:0% + +game okay so the the first branch is + + align:start position:0% +game okay so the the first branch is + + + align:start position:0% +game okay so the the first branch is +50/50 but the subsequent ones are going + + align:start position:0% +50/50 but the subsequent ones are going + + + align:start position:0% +50/50 but the subsequent ones are going +to be 2/3 1/3 in One Direction or the + + align:start position:0% +to be 2/3 1/3 in One Direction or the + + + align:start position:0% +to be 2/3 1/3 in One Direction or the +other depending on the outcome of the + + align:start position:0% +other depending on the outcome of the + + + align:start position:0% +other depending on the outcome of the +previous game maybe I shouldn't use + + align:start position:0% +previous game maybe I shouldn't use + + + align:start position:0% +previous game maybe I shouldn't use +outcome depending on the result of the + + align:start position:0% +outcome depending on the result of the + + + align:start position:0% +outcome depending on the result of the +previous + + align:start position:0% +previous + + + align:start position:0% +previous +game okay + + align:start position:0% + + + + align:start position:0% + +okay so how do we compute probabilities + + align:start position:0% +okay so how do we compute probabilities + + + align:start position:0% +okay so how do we compute probabilities +of outcomes does anybody + + align:start position:0% + + + + align:start position:0% + +remember + + align:start position:0% + + + + align:start position:0% + +yeah yeah so you multiply probabilities + + align:start position:0% +yeah yeah so you multiply probabilities + + + align:start position:0% +yeah yeah so you multiply probabilities +along paths two outcomes okay so for + + align:start position:0% +along paths two outcomes okay so for + + + align:start position:0% +along paths two outcomes okay so for +this top outcome right we've got uh 1/2 + + align:start position:0% +this top outcome right we've got uh 1/2 + + + align:start position:0% +this top outcome right we've got uh 1/2 +* 2/3 so this is probability + + align:start position:0% +* 2/3 so this is probability + + + align:start position:0% +* 2/3 so this is probability +1/3 uh win loss win has probability 1/3 + + align:start position:0% +1/3 uh win loss win has probability 1/3 + + + align:start position:0% +1/3 uh win loss win has probability 1/3 +by/ 12 by 1/3 so that's + + align:start position:0% +by/ 12 by 1/3 so that's + + + align:start position:0% +by/ 12 by 1/3 so that's +118th uh when loss loss is probability + + align:start position:0% +118th uh when loss loss is probability + + + align:start position:0% +118th uh when loss loss is probability +1/2 * 1/3 * 2/3 so that's going to be 1 + + align:start position:0% +1/2 * 1/3 * 2/3 so that's going to be 1 + + + align:start position:0% +1/2 * 1/3 * 2/3 so that's going to be 1 +nth uh and then these all + + align:start position:0% +nth uh and then these all + + + align:start position:0% +nth uh and then these all +reverse 11 18th and + + align:start position:0% +reverse 11 18th and + + + align:start position:0% +reverse 11 18th and +13 have I done that + + align:start position:0% +13 have I done that + + + align:start position:0% +13 have I done that +correctly yes that looks + + align:start position:0% +correctly yes that looks + + + align:start position:0% +correctly yes that looks +fine if I make an error please shout at + + align:start position:0% +fine if I make an error please shout at + + + align:start position:0% +fine if I make an error please shout at +me uh okay + + align:start position:0% +me uh okay + + + align:start position:0% +me uh okay +so we've got all of the uh we've got our + + align:start position:0% +so we've got all of the uh we've got our + + + align:start position:0% +so we've got all of the uh we've got our +tree diagram we've got our sample space + + align:start position:0% +tree diagram we've got our sample space + + + align:start position:0% +tree diagram we've got our sample space +we've got our our probability + + align:start position:0% +we've got our our probability + + + align:start position:0% +we've got our our probability +function uh what's the next thing we + + align:start position:0% + + + + align:start position:0% + +need do we remember + + align:start position:0% + + + + align:start position:0% + +so we've got step one the + + align:start position:0% +so we've got step one the + + + align:start position:0% +so we've got step one the +tree step two the uh + + align:start position:0% + + + + align:start position:0% + +probabilities three right was the events + + align:start position:0% +probabilities three right was the events + + + align:start position:0% +probabilities three right was the events +of + + align:start position:0% +of + + + align:start position:0% +of +Interest + + align:start position:0% + + + + align:start position:0% + +okay so what are the events we care + + align:start position:0% +okay so what are the events we care + + + align:start position:0% +okay so what are the events we care +about here + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% + + + + align:start position:0% + +pardon okay winning the tournament and + + align:start position:0% +pardon okay winning the tournament and + + + align:start position:0% +pardon okay winning the tournament and +winning the first game okay + + align:start position:0% +winning the first game okay + + + align:start position:0% +winning the first game okay +so uh a was uh y a was winning the + + align:start position:0% +so uh a was uh y a was winning the + + + align:start position:0% +so uh a was uh y a was winning the +tournament B was winning the first + + align:start position:0% +tournament B was winning the first + + + align:start position:0% +tournament B was winning the first +game uh is that + + align:start position:0% +game uh is that + + + align:start position:0% +game uh is that +all are there any other events that we + + align:start position:0% +all are there any other events that we + + + align:start position:0% +all are there any other events that we +care about + + align:start position:0% + + + + align:start position:0% + +yeah yes exactly so we also + + align:start position:0% +yeah yes exactly so we also + + + align:start position:0% +yeah yes exactly so we also +want a intersect B okay we also care + + align:start position:0% +want a intersect B okay we also care + + + align:start position:0% +want a intersect B okay we also care +about the event where you win the first + + align:start position:0% +about the event where you win the first + + + align:start position:0% +about the event where you win the first +battle and the series why is + + align:start position:0% + + + + align:start position:0% + +that would you like to explain + + align:start position:0% +that would you like to explain + + + align:start position:0% +that would you like to explain +or yeah exactly so ultimately we want + + align:start position:0% +or yeah exactly so ultimately we want + + + align:start position:0% +or yeah exactly so ultimately we want +this conditional probability right the + + align:start position:0% +this conditional probability right the + + + align:start position:0% +this conditional probability right the +probability of a given B and if we go + + align:start position:0% +probability of a given B and if we go + + + align:start position:0% +probability of a given B and if we go +back to our definition right the + + align:start position:0% +back to our definition right the + + + align:start position:0% +back to our definition right the +probability of a given B is the + + align:start position:0% +probability of a given B is the + + + align:start position:0% +probability of a given B is the +probability of a intersect B divided by + + align:start position:0% +probability of a intersect B divided by + + + align:start position:0% +probability of a intersect B divided by +the probability of B okay so as it turns + + align:start position:0% +the probability of B okay so as it turns + + + align:start position:0% +the probability of B okay so as it turns +out we kind of don't really need a right + + align:start position:0% +out we kind of don't really need a right + + + align:start position:0% +out we kind of don't really need a right +the two probabilities we really need are + + align:start position:0% +the two probabilities we really need are + + + align:start position:0% +the two probabilities we really need are +these two or the two events I suppose + + align:start position:0% +these two or the two events I suppose + + + align:start position:0% +these two or the two events I suppose +okay so finally for answer + + align:start position:0% +okay so finally for answer + + + align:start position:0% +okay so finally for answer +what is our + + align:start position:0% +what is our + + + align:start position:0% +what is our +answer well probability of a given + + align:start position:0% +answer well probability of a given + + + align:start position:0% +answer well probability of a given +b as we just said is the probability of + + align:start position:0% +b as we just said is the probability of + + + align:start position:0% +b as we just said is the probability of +a intersect B divide by probability of + + align:start position:0% +a intersect B divide by probability of + + + align:start position:0% +a intersect B divide by probability of +B + + align:start position:0% +B + + + align:start position:0% +B +okay what are each of these + + align:start position:0% + + + + align:start position:0% + +probabilities well which events or sorry + + align:start position:0% +probabilities well which events or sorry + + + align:start position:0% +probabilities well which events or sorry +which outcomes are in the event a + + align:start position:0% +which outcomes are in the event a + + + align:start position:0% +which outcomes are in the event a +intersect B + + align:start position:0% + + + + align:start position:0% + +it's ww in a intercept + + align:start position:0% +it's ww in a intercept + + + align:start position:0% +it's ww in a intercept +B + + align:start position:0% +B + + + align:start position:0% +B +yeah win loss win also yes okay win loss + + align:start position:0% +yeah win loss win also yes okay win loss + + + align:start position:0% +yeah win loss win also yes okay win loss +loss nope and all of these he lost the + + align:start position:0% +loss nope and all of these he lost the + + + align:start position:0% +loss nope and all of these he lost the +first game so these are also not in it + + align:start position:0% +first game so these are also not in it + + + align:start position:0% +first game so these are also not in it +so we care about these two uh these two + + align:start position:0% +so we care about these two uh these two + + + align:start position:0% +so we care about these two uh these two +outcomes okay so this is going to be by + + align:start position:0% +outcomes okay so this is going to be by + + + align:start position:0% +outcomes okay so this is going to be by +the sum rule 1/3 +/ 18 + + align:start position:0% + + + + align:start position:0% + +that doesn't look much like an + + align:start position:0% +that doesn't look much like an + + + align:start position:0% +that doesn't look much like an +eight oh well + + align:start position:0% +eight oh well + + + align:start position:0% +eight oh well +okay now what's the probability of + + align:start position:0% + + + + align:start position:0% + +B yeah yeah it's just one half right + + align:start position:0% +B yeah yeah it's just one half right + + + align:start position:0% +B yeah yeah it's just one half right +either by symmetry or you can actually + + align:start position:0% +either by symmetry or you can actually + + + align:start position:0% +either by symmetry or you can actually +look at what those outcomes are right + + align:start position:0% +look at what those outcomes are right + + + align:start position:0% +look at what those outcomes are right +it's these top uh these top three + + align:start position:0% + + + + align:start position:0% + +okay and if we do this arithmetic we've + + align:start position:0% +okay and if we do this arithmetic we've + + + align:start position:0% +okay and if we do this arithmetic we've +got 7/8 divided 12 which is 7 + + align:start position:0% + + + + align:start position:0% + +nths + + align:start position:0% +nths + + + align:start position:0% +nths +okay so the probability that Ash wins + + align:start position:0% +okay so the probability that Ash wins + + + align:start position:0% +okay so the probability that Ash wins +the entire series given that he won the + + align:start position:0% +the entire series given that he won the + + + align:start position:0% +the entire series given that he won the +first battle is going to be + + align:start position:0% +first battle is going to be + + + align:start position:0% +first battle is going to be +79ths okay so so far this is pretty + + align:start position:0% +79ths okay so so far this is pretty + + + align:start position:0% +79ths okay so so far this is pretty +straightforward right fairly routine uh + + align:start position:0% +straightforward right fairly routine uh + + + align:start position:0% +straightforward right fairly routine uh +mathemat well + + align:start position:0% + + + + align:start position:0% + +arithmetic but what if + + align:start position:0% +arithmetic but what if + + + align:start position:0% +arithmetic but what if +instead we ask for the probability of B + + align:start position:0% +instead we ask for the probability of B + + + align:start position:0% +instead we ask for the probability of B +given a + + align:start position:0% + + + + align:start position:0% + +what is that + + align:start position:0% + + + + align:start position:0% + +probability well numerically right we + + align:start position:0% +probability well numerically right we + + + align:start position:0% +probability well numerically right we +can compute it in exactly the same way + + align:start position:0% +can compute it in exactly the same way + + + align:start position:0% +can compute it in exactly the same way +right it's going to be the probability + + align:start position:0% +right it's going to be the probability + + + align:start position:0% +right it's going to be the probability +of the intersection divided by this time + + align:start position:0% +of the intersection divided by this time + + + align:start position:0% +of the intersection divided by this time +the probability of a rather than the + + align:start position:0% +the probability of a rather than the + + + align:start position:0% +the probability of a rather than the +probability of B but still by symmetry + + align:start position:0% +probability of B but still by symmetry + + + align:start position:0% +probability of B but still by symmetry +that probability is going to be2 + + align:start position:0% +that probability is going to be2 + + + align:start position:0% +that probability is going to be2 +okay so this is also going to be 7 + + align:start position:0% + + + + align:start position:0% + +9ths but what exactly does it + + align:start position:0% + + + + align:start position:0% + +mean + + align:start position:0% + + + + align:start position:0% + +yeah yeah so the answer was you know + + align:start position:0% +yeah yeah so the answer was you know + + + align:start position:0% +yeah yeah so the answer was you know +given that you already won the series + + align:start position:0% +given that you already won the series + + + align:start position:0% +given that you already won the series +what's the probability that he won the + + align:start position:0% +what's the probability that he won the + + + align:start position:0% +what's the probability that he won the +first + + align:start position:0% +first + + + align:start position:0% +first +battle okay now this might sound a + + align:start position:0% +battle okay now this might sound a + + + align:start position:0% +battle okay now this might sound a +little bit weird to some of you right + + align:start position:0% +little bit weird to some of you right + + + align:start position:0% +little bit weird to some of you right +like you know if we know that he's won + + align:start position:0% +like you know if we know that he's won + + + align:start position:0% +like you know if we know that he's won +the series right everything's already + + align:start position:0% +the series right everything's already + + + align:start position:0% +the series right everything's already +happened he either won the battle or he + + align:start position:0% +happened he either won the battle or he + + + align:start position:0% +happened he either won the battle or he +didn't right but uh you know when we're + + align:start position:0% +didn't right but uh you know when we're + + + align:start position:0% +didn't right but uh you know when we're +modeling probability questions you know + + align:start position:0% +modeling probability questions you know + + + align:start position:0% +modeling probability questions you know +we don't really care about any sort of + + align:start position:0% +we don't really care about any sort of + + + align:start position:0% +we don't really care about any sort of +temporal relations or anything like that + + align:start position:0% +temporal relations or anything like that + + + align:start position:0% +temporal relations or anything like that +or even causal ones right like uh you + + align:start position:0% +or even causal ones right like uh you + + + align:start position:0% +or even causal ones right like uh you +know we're just uh like it it's all just + + align:start position:0% +know we're just uh like it it's all just + + + align:start position:0% +know we're just uh like it it's all just +you know numerical right you can kind of + + align:start position:0% +you know numerical right you can kind of + + + align:start position:0% +you know numerical right you can kind of +think of it a bit like an inference + + align:start position:0% +think of it a bit like an inference + + + align:start position:0% +think of it a bit like an inference +right like you know you've got some + + align:start position:0% +right like you know you've got some + + + align:start position:0% +right like you know you've got some +uncertainty right like you know maybe + + align:start position:0% +uncertainty right like you know maybe + + + align:start position:0% +uncertainty right like you know maybe +you're told that he won the battle you + + align:start position:0% +you're told that he won the battle you + + + align:start position:0% +you're told that he won the battle you +want to or sorry you're told that he won + + align:start position:0% +want to or sorry you're told that he won + + + align:start position:0% +want to or sorry you're told that he won +the series you want to update your + + align:start position:0% +the series you want to update your + + + align:start position:0% +the series you want to update your +belief that you know maybe he won the + + align:start position:0% +belief that you know maybe he won the + + + align:start position:0% +belief that you know maybe he won the +the first battle maybe he didn't uh and + + align:start position:0% +the first battle maybe he didn't uh and + + + align:start position:0% +the first battle maybe he didn't uh and +maybe you're not entirely confident in + + align:start position:0% +maybe you're not entirely confident in + + + align:start position:0% +maybe you're not entirely confident in +it uh but you'd like to estimate you + + align:start position:0% +it uh but you'd like to estimate you + + + align:start position:0% +it uh but you'd like to estimate you +know how confident you should be uh that + + align:start position:0% +know how confident you should be uh that + + + align:start position:0% +know how confident you should be uh that +might be one way to think about + + align:start position:0% +might be one way to think about + + + align:start position:0% +might be one way to think about +it um + + align:start position:0% +it um + + + align:start position:0% +it um +so in a sense it's kind of like looking + + align:start position:0% +so in a sense it's kind of like looking + + + align:start position:0% +so in a sense it's kind of like looking +at a backwards probability that you know + + align:start position:0% +at a backwards probability that you know + + + align:start position:0% +at a backwards probability that you know +something in the past has happened given + + align:start position:0% +something in the past has happened given + + + align:start position:0% +something in the past has happened given +that we observed something in the + + align:start position:0% +that we observed something in the + + + align:start position:0% +that we observed something in the +future uh so you know in general you + + align:start position:0% +future uh so you know in general you + + + align:start position:0% +future uh so you know in general you +know they they won't always be the same + + align:start position:0% +know they they won't always be the same + + + align:start position:0% +know they they won't always be the same +like this like you can kind of relate + + align:start position:0% +like this like you can kind of relate + + + align:start position:0% +like this like you can kind of relate +the probability of B given a to the + + align:start position:0% +the probability of B given a to the + + + align:start position:0% +the probability of B given a to the +probability of a given B they won't + + align:start position:0% +probability of a given B they won't + + + align:start position:0% +probability of a given B they won't +always be equal okay let's see how to + + align:start position:0% +always be equal okay let's see how to + + + align:start position:0% +always be equal okay let's see how to +relate + + align:start position:0% + + + + align:start position:0% + +them it just so happens that in this + + align:start position:0% +them it just so happens that in this + + + align:start position:0% +them it just so happens that in this +case right these two + + align:start position:0% +case right these two + + + align:start position:0% +case right these two +things + + align:start position:0% +things + + + align:start position:0% +things +oh these two things have the same + + align:start position:0% +oh these two things have the same + + + align:start position:0% +oh these two things have the same +probability okay so that's really the + + align:start position:0% +probability okay so that's really the + + + align:start position:0% +probability okay so that's really the +core reason why they were + + align:start position:0% +core reason why they were + + + align:start position:0% +core reason why they were +equal but more generally we have the + + align:start position:0% + + + + align:start position:0% + +following okay this is called base + + align:start position:0% +following okay this is called base + + + align:start position:0% +following okay this is called base +rule + + align:start position:0% +rule + + + align:start position:0% +rule +okay uh you can kind of think of it is + + align:start position:0% +okay uh you can kind of think of it is + + + align:start position:0% +okay uh you can kind of think of it is +you know it's just the product rule in + + align:start position:0% +you know it's just the product rule in + + + align:start position:0% +you know it's just the product rule in +disguise right so the + + align:start position:0% +disguise right so the + + + align:start position:0% +disguise right so the +probability of B given + + align:start position:0% +probability of B given + + + align:start position:0% +probability of B given +a equals the probability Oops why don't + + align:start position:0% +a equals the probability Oops why don't + + + align:start position:0% +a equals the probability Oops why don't +I split this into two + + align:start position:0% +I split this into two + + + align:start position:0% +I split this into two +lines probability of a given + + align:start position:0% +lines probability of a given + + + align:start position:0% +lines probability of a given +B probability of + + align:start position:0% +B probability of + + + align:start position:0% +B probability of +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +B divided by probability of + + align:start position:0% +B divided by probability of + + + align:start position:0% +B divided by probability of +a okay so in the example we just saw + + align:start position:0% +a okay so in the example we just saw + + + align:start position:0% +a okay so in the example we just saw +these two are the same so they just + + align:start position:0% +these two are the same so they just + + + align:start position:0% +these two are the same so they just +cancel uh but more generally you want to + + align:start position:0% +cancel uh but more generally you want to + + + align:start position:0% +cancel uh but more generally you want to +multiply by the quotient okay and you + + align:start position:0% +multiply by the quotient okay and you + + + align:start position:0% +multiply by the quotient okay and you +can kind of think of this as the product + + align:start position:0% +can kind of think of this as the product + + + align:start position:0% +can kind of think of this as the product +rule in disguise right like if you just + + align:start position:0% +rule in disguise right like if you just + + + align:start position:0% +rule in disguise right like if you just +move this probability of a over to this + + align:start position:0% +move this probability of a over to this + + + align:start position:0% +move this probability of a over to this +side right uh now you're just Computing + + align:start position:0% +side right uh now you're just Computing + + + align:start position:0% +side right uh now you're just Computing +the probability of the intersection of A + + align:start position:0% +the probability of the intersection of A + + + align:start position:0% +the probability of the intersection of A +and B on both sides does that make + + align:start position:0% +and B on both sides does that make + + + align:start position:0% +and B on both sides does that make +sense but uh it can often be useful uh + + align:start position:0% +sense but uh it can often be useful uh + + + align:start position:0% +sense but uh it can often be useful uh +you know even though it's not really + + align:start position:0% +you know even though it's not really + + + align:start position:0% +you know even though it's not really +saying anything new it can often be + + align:start position:0% +saying anything new it can often be + + + align:start position:0% +saying anything new it can often be +useful to think about it in this way + + align:start position:0% +useful to think about it in this way + + + align:start position:0% +useful to think about it in this way +okay if you kind of want to reverse the + + align:start position:0% +okay if you kind of want to reverse the + + + align:start position:0% +okay if you kind of want to reverse the +direction of an + + align:start position:0% +direction of an + + + align:start position:0% +direction of an +inference uh you want to multiply by the + + align:start position:0% +inference uh you want to multiply by the + + + align:start position:0% +inference uh you want to multiply by the +quotient of the two event the two + + align:start position:0% +quotient of the two event the two + + + align:start position:0% +quotient of the two event the two +probabilities of the events that you + + align:start position:0% +probabilities of the events that you + + + align:start position:0% +probabilities of the events that you +care about + + align:start position:0% +care about + + + align:start position:0% +care about +okay + + align:start position:0% +okay + + + align:start position:0% +okay +uh and one particularly useful + + align:start position:0% +uh and one particularly useful + + + align:start position:0% +uh and one particularly useful +uh consequence of this is the following + + align:start position:0% +uh consequence of this is the following + + + align:start position:0% +uh consequence of this is the following +so suppose we have two events B and C + + align:start position:0% +so suppose we have two events B and C + + + align:start position:0% +so suppose we have two events B and C +and we're kind of trying to condition + + align:start position:0% +and we're kind of trying to condition + + + align:start position:0% +and we're kind of trying to condition +them both on the same + + align:start position:0% +them both on the same + + + align:start position:0% +them both on the same +event + + align:start position:0% +event + + + align:start position:0% +event +okay + + align:start position:0% + + + + align:start position:0% + +so what is the probability of C given + + align:start position:0% +so what is the probability of C given + + + align:start position:0% +so what is the probability of C given +a no B given a divided by the + + align:start position:0% +a no B given a divided by the + + + align:start position:0% +a no B given a divided by the +probability of C given + + align:start position:0% +probability of C given + + + align:start position:0% +probability of C given +a + + align:start position:0% + + + + align:start position:0% + +okay and in particular often we would + + align:start position:0% +okay and in particular often we would + + + align:start position:0% +okay and in particular often we would +take C to be the complement of b or + + align:start position:0% +take C to be the complement of b or + + + align:start position:0% +take C to be the complement of b or +something like that and that will then + + align:start position:0% +something like that and that will then + + + align:start position:0% +something like that and that will then +help us to compute this probability of + + align:start position:0% +help us to compute this probability of + + + align:start position:0% +help us to compute this probability of +being given a + + align:start position:0% +being given a + + + align:start position:0% +being given a +okay so as it turns out this is going to + + align:start position:0% +okay so as it turns out this is going to + + + align:start position:0% +okay so as it turns out this is going to +be the probability of a given + + align:start position:0% +be the probability of a given + + + align:start position:0% +be the probability of a given +B times the probability of + + align:start position:0% +B times the probability of + + + align:start position:0% +B times the probability of +B divided + + align:start position:0% +B divided + + + align:start position:0% +B divided +by probability of a given + + align:start position:0% +by probability of a given + + + align:start position:0% +by probability of a given +C oops + + align:start position:0% +C oops + + + align:start position:0% +C oops +probability of C + + align:start position:0% + + + + align:start position:0% + +so does that make sense to + + align:start position:0% + + + + align:start position:0% + +everybody and the reason that this might + + align:start position:0% +everybody and the reason that this might + + + align:start position:0% +everybody and the reason that this might +you know this in particular might be + + align:start position:0% +you know this in particular might be + + + align:start position:0% +you know this in particular might be +useful uh in order to compute the + + align:start position:0% +useful uh in order to compute the + + + align:start position:0% +useful uh in order to compute the +probability of B you know if we uh use B + + align:start position:0% +probability of B you know if we uh use B + + + align:start position:0% +probability of B you know if we uh use B +complement to C + + align:start position:0% +complement to C + + + align:start position:0% +complement to C +right this right hand side here + + align:start position:0% +right this right hand side here + + + align:start position:0% +right this right hand side here +does not depend on the probability of a + + align:start position:0% +does not depend on the probability of a + + + align:start position:0% +does not depend on the probability of a +right like we don't have to compute the + + align:start position:0% +right like we don't have to compute the + + + align:start position:0% +right like we don't have to compute the +probability of a so maybe if a is some + + align:start position:0% +probability of a so maybe if a is some + + + align:start position:0% +probability of a so maybe if a is some +really nasty event right and we don't + + align:start position:0% +really nasty event right and we don't + + + align:start position:0% +really nasty event right and we don't +actually want to compute its probability + + align:start position:0% +actually want to compute its probability + + + align:start position:0% +actually want to compute its probability +but we can still condition on it we + + align:start position:0% +but we can still condition on it we + + + align:start position:0% +but we can still condition on it we +might still be able to use this formula + + align:start position:0% +might still be able to use this formula + + + align:start position:0% +might still be able to use this formula +more easily than we could use this + + align:start position:0% +more easily than we could use this + + + align:start position:0% +more easily than we could use this +one okay does that make sense to + + align:start position:0% + + + + align:start position:0% + +everybody + + align:start position:0% +everybody + + + align:start position:0% +everybody +okay so let's take a look at a couple of + + align:start position:0% +okay so let's take a look at a couple of + + + align:start position:0% +okay so let's take a look at a couple of +applications of BAS + + align:start position:0% + + + + align:start position:0% + +R uh or actually + + align:start position:0% + + + + align:start position:0% + +first first maybe I should uh give you a + + align:start position:0% +first first maybe I should uh give you a + + + align:start position:0% +first first maybe I should uh give you a +brief lesson in + + align:start position:0% +brief lesson in + + + align:start position:0% +brief lesson in +statistics uh so + + align:start position:0% + + + + align:start position:0% + +terminology the probability of uh a + + align:start position:0% +terminology the probability of uh a + + + align:start position:0% +terminology the probability of uh a +given + + align:start position:0% + + + + align:start position:0% + +B uh this would often be called the + + align:start position:0% +B uh this would often be called the + + + align:start position:0% +B uh this would often be called the +likelihood + + align:start position:0% + + + + align:start position:0% + +of a given + + align:start position:0% + + + + align:start position:0% + +B okay so if any of you have ever seen + + align:start position:0% +B okay so if any of you have ever seen + + + align:start position:0% +B okay so if any of you have ever seen +like maximum likelihood estimations or + + align:start position:0% +like maximum likelihood estimations or + + + align:start position:0% +like maximum likelihood estimations or +anything like that that's where this + + align:start position:0% +anything like that that's where this + + + align:start position:0% +anything like that that's where this +comes from or this is where that comes + + align:start position:0% +comes from or this is where that comes + + + align:start position:0% +comes from or this is where that comes +from + + align:start position:0% +from + + + align:start position:0% +from +sorry uh probability of B + + align:start position:0% + + + + align:start position:0% + +we call the prior + + align:start position:0% + + + + align:start position:0% + +probability of + + align:start position:0% + + + + align:start position:0% + +B and the left hand side the probability + + align:start position:0% +B and the left hand side the probability + + + align:start position:0% +B and the left hand side the probability +of being given an + + align:start position:0% + + + + align:start position:0% + +a is the posterior + + align:start position:0% + + + + align:start position:0% + +of + + align:start position:0% +of + + + align:start position:0% +of +B uh actually we don't usually specify a + + align:start position:0% +B uh actually we don't usually specify a + + + align:start position:0% +B uh actually we don't usually specify a +with that + + align:start position:0% +with that + + + align:start position:0% +with that +oops + + align:start position:0% +oops + + + align:start position:0% +oops +okay so this is how you would normally + + align:start position:0% +okay so this is how you would normally + + + align:start position:0% +okay so this is how you would normally +talk about it like in statistics or + + align:start position:0% +talk about it like in statistics or + + + align:start position:0% +talk about it like in statistics or +something like that uh the the + + align:start position:0% +something like that uh the the + + + align:start position:0% +something like that uh the the +likelihood of a given B the prior + + align:start position:0% +likelihood of a given B the prior + + + align:start position:0% +likelihood of a given B the prior +probability and the posterior + + align:start position:0% +probability and the posterior + + + align:start position:0% +probability and the posterior +probability because basically what + + align:start position:0% +probability because basically what + + + align:start position:0% +probability because basically what +you're doing right is you're starting + + align:start position:0% +you're doing right is you're starting + + + align:start position:0% +you're doing right is you're starting +with some prior right if you don't know + + align:start position:0% +with some prior right if you don't know + + + align:start position:0% +with some prior right if you don't know +anything like this is kind of what you + + align:start position:0% +anything like this is kind of what you + + + align:start position:0% +anything like this is kind of what you +think the the probability of B should be + + align:start position:0% +think the the probability of B should be + + + align:start position:0% +think the the probability of B should be +and now you make some uh some + + align:start position:0% +and now you make some uh some + + + align:start position:0% +and now you make some uh some +observation a right and so now you + + align:start position:0% +observation a right and so now you + + + align:start position:0% +observation a right and so now you +update and you got a posterior + + align:start position:0% +update and you got a posterior + + + align:start position:0% +update and you got a posterior +probability of B you know condition on + + align:start position:0% +probability of B you know condition on + + + align:start position:0% +probability of B you know condition on +that that uh uh observation does that + + align:start position:0% +that that uh uh observation does that + + + align:start position:0% +that that uh uh observation does that +make + + align:start position:0% + + + + align:start position:0% + +sense + + align:start position:0% +sense + + + align:start position:0% +sense +okay so why don't we take a look at a + + align:start position:0% +okay so why don't we take a look at a + + + align:start position:0% +okay so why don't we take a look at a +couple of examples then + + align:start position:0% + + + + align:start position:0% + +uh + + align:start position:0% +uh + + + align:start position:0% +uh +here hopefully everybody is okay with + + align:start position:0% +here hopefully everybody is okay with + + + align:start position:0% +here hopefully everybody is okay with +those okay so first example suppose I've + + align:start position:0% +those okay so first example suppose I've + + + align:start position:0% +those okay so first example suppose I've +got two + + align:start position:0% +got two + + + align:start position:0% +got two +coins okay uh I've got one Fair coin + + align:start position:0% +coins okay uh I've got one Fair coin + + + align:start position:0% +coins okay uh I've got one Fair coin +right I toss this coin and it'll come up + + align:start position:0% +right I toss this coin and it'll come up + + + align:start position:0% +right I toss this coin and it'll come up +heads with 50% probability tails with + + align:start position:0% +heads with 50% probability tails with + + + align:start position:0% +heads with 50% probability tails with +50% probability okay and I've also got a + + align:start position:0% +50% probability okay and I've also got a + + + align:start position:0% +50% probability okay and I've also got a +trick coin right it's uh you know double + + align:start position:0% +trick coin right it's uh you know double + + + align:start position:0% +trick coin right it's uh you know double +heads I flip it I always get + + align:start position:0% +heads I flip it I always get + + + align:start position:0% +heads I flip it I always get +heads + + align:start position:0% +heads + + + align:start position:0% +heads +okay uh suppose I pick one of these + + align:start position:0% +okay uh suppose I pick one of these + + + align:start position:0% +okay uh suppose I pick one of these +coins uniformly at + + align:start position:0% +coins uniformly at + + + align:start position:0% +coins uniformly at +random I flip that + + align:start position:0% +random I flip that + + + align:start position:0% +random I flip that +coin and it comes up + + align:start position:0% +coin and it comes up + + + align:start position:0% +coin and it comes up +heads okay what is the probability that + + align:start position:0% +heads okay what is the probability that + + + align:start position:0% +heads okay what is the probability that +I picked the far coin to begin with as + + align:start position:0% +I picked the far coin to begin with as + + + align:start position:0% +I picked the far coin to begin with as +opposed to the biased one + + align:start position:0% + + + + align:start position:0% + +any ideas does anybody have any guesses + + align:start position:0% +any ideas does anybody have any guesses + + + align:start position:0% +any ideas does anybody have any guesses +as to what the probability + + align:start position:0% + + + + align:start position:0% + +is who wants to just dra draw the tree + + align:start position:0% +is who wants to just dra draw the tree + + + align:start position:0% +is who wants to just dra draw the tree +diagram few people people aren't as + + align:start position:0% +diagram few people people aren't as + + + align:start position:0% +diagram few people people aren't as +enthusiastic about it as as they were on + + align:start position:0% +enthusiastic about it as as they were on + + + align:start position:0% +enthusiastic about it as as they were on +Tuesday that's uh that's slightly + + align:start position:0% +Tuesday that's uh that's slightly + + + align:start position:0% +Tuesday that's uh that's slightly +unfortunate let's do it anyway uh no + + align:start position:0% +unfortunate let's do it anyway uh no + + + align:start position:0% +unfortunate let's do it anyway uh no +let's let's first uh you know let's make + + align:start position:0% +let's let's first uh you know let's make + + + align:start position:0% +let's let's first uh you know let's make +precise the events that we care about + + align:start position:0% +precise the events that we care about + + + align:start position:0% +precise the events that we care about +okay um so let's let H be the event + + align:start position:0% + + + + align:start position:0% + +uh that we flipped + + align:start position:0% + + + + align:start position:0% + +heads uh and uh f is the + + align:start position:0% +heads uh and uh f is the + + + align:start position:0% +heads uh and uh f is the +event picked the fa + + align:start position:0% + + + + align:start position:0% + +coin + + align:start position:0% +coin + + + align:start position:0% +coin +okay so what is the probability that + + align:start position:0% +okay so what is the probability that + + + align:start position:0% +okay so what is the probability that +we're trying to compute + + align:start position:0% + + + + align:start position:0% + +in terms of these two + + align:start position:0% +in terms of these two + + + align:start position:0% +in terms of these two +quantities + + align:start position:0% + + + + align:start position:0% + +yeah probability of f given H + + align:start position:0% + + + + align:start position:0% + +yes + + align:start position:0% +yes + + + align:start position:0% +yes +okay so how might we compute + + align:start position:0% +okay so how might we compute + + + align:start position:0% +okay so how might we compute +this people didn't seem too enthusiastic + + align:start position:0% +this people didn't seem too enthusiastic + + + align:start position:0% +this people didn't seem too enthusiastic +about the tree diagram so what else + + align:start position:0% +about the tree diagram so what else + + + align:start position:0% +about the tree diagram so what else +could we do instead + + align:start position:0% + + + + align:start position:0% + +does anybody see a way to use base + + align:start position:0% + + + + align:start position:0% + +rule yeah or just a stretch + + align:start position:0% + + + + align:start position:0% + +sorry + + align:start position:0% + + + + align:start position:0% + +yeah yeah the probability of H given f + + align:start position:0% +yeah yeah the probability of H given f + + + align:start position:0% +yeah yeah the probability of H given f +is easy right that's that's 50% okay so + + align:start position:0% +is easy right that's that's 50% okay so + + + align:start position:0% +is easy right that's that's 50% okay so +that's that's an easy known quantity so + + align:start position:0% +that's that's an easy known quantity so + + + align:start position:0% +that's that's an easy known quantity so +if we use base rule right that that + + align:start position:0% +if we use base rule right that that + + + align:start position:0% +if we use base rule right that that +might make it easier to uh to compute + + align:start position:0% +might make it easier to uh to compute + + + align:start position:0% +might make it easier to uh to compute +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so uh actually why don't we use the uh + + align:start position:0% +so uh actually why don't we use the uh + + + align:start position:0% +so uh actually why don't we use the uh +you know slightly more complicated + + align:start position:0% +you know slightly more complicated + + + align:start position:0% +you know slightly more complicated +version of Base rule so let's compute + + align:start position:0% +version of Base rule so let's compute + + + align:start position:0% +version of Base rule so let's compute +the ratio of the probability that we + + align:start position:0% +the ratio of the probability that we + + + align:start position:0% +the ratio of the probability that we +picked the faircoin given that we + + align:start position:0% +picked the faircoin given that we + + + align:start position:0% +picked the faircoin given that we +observed a heads versus you know the the + + align:start position:0% +observed a heads versus you know the the + + + align:start position:0% +observed a heads versus you know the the +probability of the of picking the biased + + align:start position:0% +probability of the of picking the biased + + + align:start position:0% +probability of the of picking the biased +coin given that we observed a heads + + align:start position:0% +coin given that we observed a heads + + + align:start position:0% +coin given that we observed a heads +okay so the + + align:start position:0% +okay so the + + + align:start position:0% +okay so the +probability of f given + + align:start position:0% +probability of f given + + + align:start position:0% +probability of f given +H over probability of not F given + + align:start position:0% + + + + align:start position:0% + +H so what was that + + align:start position:0% + + + + align:start position:0% + +so right base rule is about you know + + align:start position:0% +so right base rule is about you know + + + align:start position:0% +so right base rule is about you know +flipping the uh flipping the order right + + align:start position:0% +flipping the uh flipping the order right + + + align:start position:0% +flipping the uh flipping the order right +so instead of f conditioned on H we want + + align:start position:0% +so instead of f conditioned on H we want + + + align:start position:0% +so instead of f conditioned on H we want +H conditioned on + + align:start position:0% +H conditioned on + + + align:start position:0% +H conditioned on +F multiplied by + + align:start position:0% + + + + align:start position:0% + +what yeah yeah probability of f + + align:start position:0% + + + + align:start position:0% + +okay and on the bottom we can do the + + align:start position:0% +okay and on the bottom we can do the + + + align:start position:0% +okay and on the bottom we can do the +same thing probability of H given not + + align:start position:0% +same thing probability of H given not + + + align:start position:0% +same thing probability of H given not +F times the probability of not + + align:start position:0% + + + + align:start position:0% + +F + + align:start position:0% +F + + + align:start position:0% +F +okay so this expression is much easier + + align:start position:0% +okay so this expression is much easier + + + align:start position:0% +okay so this expression is much easier +to work with right what's the + + align:start position:0% +to work with right what's the + + + align:start position:0% +to work with right what's the +probability of H given f + + align:start position:0% + + + + align:start position:0% + +yep2 + + align:start position:0% + + + + align:start position:0% + +yeah okay what about the probability of + + align:start position:0% +yeah okay what about the probability of + + + align:start position:0% +yeah okay what about the probability of +H given not + + align:start position:0% + + + + align:start position:0% + +F yeah + + align:start position:0% + + + + align:start position:0% + +one and probability of F and not + + align:start position:0% + + + + align:start position:0% + +F those are each one half by assumption + + align:start position:0% +F those are each one half by assumption + + + align:start position:0% +F those are each one half by assumption +okay + + align:start position:0% + + + + align:start position:0% + +okay so those just cancel and we are + + align:start position:0% +okay so those just cancel and we are + + + align:start position:0% +okay so those just cancel and we are +left + + align:start position:0% + + + + align:start position:0% + +with2 + + align:start position:0% +with2 + + + align:start position:0% +with2 +okay so + + align:start position:0% +okay so + + + align:start position:0% +okay so +now what is this + + align:start position:0% + + + + align:start position:0% + +probability we computed the ratio of + + align:start position:0% +probability we computed the ratio of + + + align:start position:0% +probability we computed the ratio of +this probability to its complement + + align:start position:0% +this probability to its complement + + + align:start position:0% +this probability to its complement +right so what does that tell us the uh + + align:start position:0% +right so what does that tell us the uh + + + align:start position:0% +right so what does that tell us the uh +probability + + align:start position:0% + + + + align:start position:0% + +is yeah one3 + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% + + + + align:start position:0% + +okay so OB serve here that uh if our + + align:start position:0% +okay so OB serve here that uh if our + + + align:start position:0% +okay so OB serve here that uh if our +prior changes right if the if the chance + + align:start position:0% +prior changes right if the if the chance + + + align:start position:0% +prior changes right if the if the chance +that we are you know picking the fa coin + + align:start position:0% +that we are you know picking the fa coin + + + align:start position:0% +that we are you know picking the fa coin +to begin with + + align:start position:0% +to begin with + + + align:start position:0% +to begin with +changes uh this posterior probability + + align:start position:0% +changes uh this posterior probability + + + align:start position:0% +changes uh this posterior probability +also + + align:start position:0% +also + + + align:start position:0% +also +changes okay + + align:start position:0% +changes okay + + + align:start position:0% +changes okay +so you know if if I if I originally + + align:start position:0% +so you know if if I if I originally + + + align:start position:0% +so you know if if I if I originally +picked the Fair coin with very high + + align:start position:0% +picked the Fair coin with very high + + + align:start position:0% +picked the Fair coin with very high +probability + + align:start position:0% +probability + + + align:start position:0% +probability +right uh and then I observe a heads + + align:start position:0% +right uh and then I observe a heads + + + align:start position:0% +right uh and then I observe a heads +right do you think the uh probability + + align:start position:0% +right do you think the uh probability + + + align:start position:0% +right do you think the uh probability +that a the the posterior probability + + align:start position:0% +that a the the posterior probability + + + align:start position:0% +that a the the posterior probability +should be the same higher or + + align:start position:0% + + + + align:start position:0% + +lower oh yeah how did we get a third oh + + align:start position:0% +lower oh yeah how did we get a third oh + + + align:start position:0% +lower oh yeah how did we get a third oh +question how did we get a + + align:start position:0% +question how did we get a + + + align:start position:0% +question how did we get a +third uh so the ratio of this to its + + align:start position:0% +third uh so the ratio of this to its + + + align:start position:0% +third uh so the ratio of this to its +complement is 12 right they sum to one + + align:start position:0% +complement is 12 right they sum to one + + + align:start position:0% +complement is 12 right they sum to one +right so they're 1/3 and 2/3 + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +yeah the numerical values of h and + + align:start position:0% +yeah the numerical values of h and + + + align:start position:0% +yeah the numerical values of h and +f uh so h and f are events they're not + + align:start position:0% +f uh so h and f are events they're not + + + align:start position:0% +f uh so h and f are events they're not +uh they're not numbers + + align:start position:0% +uh they're not numbers + + + align:start position:0% +uh they're not numbers +exactly right so you know H is the event + + align:start position:0% +exactly right so you know H is the event + + + align:start position:0% +exactly right so you know H is the event +that you know whichever coin I flipped + + align:start position:0% +that you know whichever coin I flipped + + + align:start position:0% +that you know whichever coin I flipped +uh I got a heads on + + align:start position:0% +uh I got a heads on + + + align:start position:0% +uh I got a heads on +it right + + align:start position:0% +it right + + + align:start position:0% +it right +and F is the event that the the coin I + + align:start position:0% +and F is the event that the the coin I + + + align:start position:0% +and F is the event that the the coin I +picked was the Fair + + align:start position:0% +picked was the Fair + + + align:start position:0% +picked was the Fair +one okay so they're not really numbers + + align:start position:0% +one okay so they're not really numbers + + + align:start position:0% +one okay so they're not really numbers +they're just you know sets of outcomes + + align:start position:0% +they're just you know sets of outcomes + + + align:start position:0% +they're just you know sets of outcomes +that could have + + align:start position:0% +that could have + + + align:start position:0% +that could have +happened okay + + align:start position:0% +happened okay + + + align:start position:0% +happened okay +yeah oh the assumptions right so um you + + align:start position:0% +yeah oh the assumptions right so um you + + + align:start position:0% +yeah oh the assumptions right so um you +know pick uh + + align:start position:0% +know pick uh + + + align:start position:0% +know pick uh +fair or + + align:start position:0% + + + + align:start position:0% + +biased uh uniformly + + align:start position:0% + + + + align:start position:0% + +and then uh flip + + align:start position:0% + + + + align:start position:0% + +it so fair means it comes up with 5050 + + align:start position:0% +it so fair means it comes up with 5050 + + + align:start position:0% +it so fair means it comes up with 5050 +you know heads or tails biased it's a + + align:start position:0% +you know heads or tails biased it's a + + + align:start position:0% +you know heads or tails biased it's a +two-headed + + align:start position:0% +two-headed + + + align:start position:0% +two-headed +coin + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +yeah uh explain where the one/ third + + align:start position:0% +yeah uh explain where the one/ third + + + align:start position:0% +yeah uh explain where the one/ third +came from again okay so uh the + + align:start position:0% +came from again okay so uh the + + + align:start position:0% +came from again okay so uh the +probability of f given H over not F + + align:start position:0% +probability of f given H over not F + + + align:start position:0% +probability of f given H over not F +given h + + align:start position:0% +given h + + + align:start position:0% +given h +right these are complimentary + + align:start position:0% +right these are complimentary + + + align:start position:0% +right these are complimentary +probabilities they should sum to one + + align:start position:0% +probabilities they should sum to one + + + align:start position:0% +probabilities they should sum to one +okay so we figured that the ratio right + + align:start position:0% +okay so we figured that the ratio right + + + align:start position:0% +okay so we figured that the ratio right +is + + align:start position:0% + + + + align:start position:0% + +uh2 okay so you know if we want them to + + align:start position:0% +uh2 okay so you know if we want them to + + + align:start position:0% +uh2 okay so you know if we want them to +to sum to one then then they should be + + align:start position:0% +to sum to one then then they should be + + + align:start position:0% +to sum to one then then they should be +1/3 and + + align:start position:0% +1/3 and + + + align:start position:0% +1/3 and +2/3 okay does does that make sense + + align:start position:0% +2/3 okay does does that make sense + + + align:start position:0% +2/3 okay does does that make sense +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +okay yeah + + align:start position:0% + + + + align:start position:0% + +sorry oh question if it's biased do we + + align:start position:0% +sorry oh question if it's biased do we + + + align:start position:0% +sorry oh question if it's biased do we +care in which direction it's biased uh + + align:start position:0% +care in which direction it's biased uh + + + align:start position:0% +care in which direction it's biased uh +yes + + align:start position:0% +yes + + + align:start position:0% +yes +absolutely so if it's you know a double + + align:start position:0% +absolutely so if it's you know a double + + + align:start position:0% +absolutely so if it's you know a double +tailed coin instead of a double heads + + align:start position:0% +tailed coin instead of a double heads + + + align:start position:0% +tailed coin instead of a double heads +coin right you know if I observe a heads + + align:start position:0% +coin right you know if I observe a heads + + + align:start position:0% +coin right you know if I observe a heads +it must be the Fair coin right because + + align:start position:0% +it must be the Fair coin right because + + + align:start position:0% +it must be the Fair coin right because +the the double Tales coin cannot get a + + align:start position:0% +the the double Tales coin cannot get a + + + align:start position:0% +the the double Tales coin cannot get a +heads right so then my probability is + + align:start position:0% +heads right so then my probability is + + + align:start position:0% +heads right so then my probability is +just one + + align:start position:0% + + + + align:start position:0% + +okay are people reasonably happy with + + align:start position:0% +okay are people reasonably happy with + + + align:start position:0% +okay are people reasonably happy with +this example shall we move on to a + + align:start position:0% +this example shall we move on to a + + + align:start position:0% +this example shall we move on to a +second + + align:start position:0% + + + + align:start position:0% + +one + + align:start position:0% +one + + + align:start position:0% +one +okay second example Co testing woohoo + + align:start position:0% +okay second example Co testing woohoo + + + align:start position:0% +okay second example Co testing woohoo +everybody loves Co testing right oh I + + align:start position:0% +everybody loves Co testing right oh I + + + align:start position:0% +everybody loves Co testing right oh I +suppose you most of you probably weren't + + align:start position:0% +suppose you most of you probably weren't + + + align:start position:0% +suppose you most of you probably weren't +here when there were those like you know + + align:start position:0% +here when there were those like you know + + + align:start position:0% +here when there were those like you know +daily or near daily nasal swabs right + + align:start position:0% +daily or near daily nasal swabs right + + + align:start position:0% +daily or near daily nasal swabs right +well those those were fun times okay + + align:start position:0% +well those those were fun times okay + + + align:start position:0% +well those those were fun times okay +um so in the next next couple of + + align:start position:0% +um so in the next next couple of + + + align:start position:0% +um so in the next next couple of +examples we're going to see some you + + align:start position:0% +examples we're going to see some you + + + align:start position:0% +examples we're going to see some you +know rather counterintuitive behavior + + align:start position:0% +know rather counterintuitive behavior + + + align:start position:0% +know rather counterintuitive behavior +that uh arises from base rule okay + + align:start position:0% +that uh arises from base rule okay + + + align:start position:0% +that uh arises from base rule okay +so you know you just as we were + + align:start position:0% +so you know you just as we were + + + align:start position:0% +so you know you just as we were +discussing last time you kind of want to + + align:start position:0% +discussing last time you kind of want to + + + align:start position:0% +discussing last time you kind of want to +throw away uh intuitive reasoning and + + align:start position:0% +throw away uh intuitive reasoning and + + + align:start position:0% +throw away uh intuitive reasoning and +you know just go with the numbers okay + + align:start position:0% +you know just go with the numbers okay + + + align:start position:0% +you know just go with the numbers okay +so suppose + + align:start position:0% + + + + align:start position:0% + +10% of + + align:start position:0% + + + + align:start position:0% + +MIT has + + align:start position:0% + + + + align:start position:0% + +Co + + align:start position:0% +Co + + + align:start position:0% +Co +okay uh and everybody has to take a + + align:start position:0% +okay uh and everybody has to take a + + + align:start position:0% +okay uh and everybody has to take a +covid test okay uh they have a false + + align:start position:0% +covid test okay uh they have a false + + + align:start position:0% +covid test okay uh they have a false +positive + + align:start position:0% + + + + align:start position:0% + +rate uh uh of uh + + align:start position:0% + + + + align:start position:0% + +30% and false negative + + align:start position:0% + + + + align:start position:0% + +rate of + + align:start position:0% +rate of + + + align:start position:0% +rate of +10% okay so false positive rate means + + align:start position:0% +10% okay so false positive rate means + + + align:start position:0% +10% okay so false positive rate means +you know uh if I'm am healthy and I take + + align:start position:0% +you know uh if I'm am healthy and I take + + + align:start position:0% +you know uh if I'm am healthy and I take +a covid test there's a 30% chance that + + align:start position:0% +a covid test there's a 30% chance that + + + align:start position:0% +a covid test there's a 30% chance that +it's going to be wrong and it's going to + + align:start position:0% +it's going to be wrong and it's going to + + + align:start position:0% +it's going to be wrong and it's going to +say that I'm I have Co okay okay so it's + + align:start position:0% +say that I'm I have Co okay okay so it's + + + align:start position:0% +say that I'm I have Co okay okay so it's +it's falsely reporting a positive + + align:start position:0% +it's falsely reporting a positive + + + align:start position:0% +it's falsely reporting a positive +positive result uh and false negative is + + align:start position:0% +positive result uh and false negative is + + + align:start position:0% +positive result uh and false negative is +the opposite so if I'm sick and I take a + + align:start position:0% +the opposite so if I'm sick and I take a + + + align:start position:0% +the opposite so if I'm sick and I take a +covid test there is a 10% chance that it + + align:start position:0% +covid test there is a 10% chance that it + + + align:start position:0% +covid test there is a 10% chance that it +does not detect it and it reports that + + align:start position:0% +does not detect it and it reports that + + + align:start position:0% +does not detect it and it reports that +I'm + + align:start position:0% +I'm + + + align:start position:0% +I'm +healthy okay do does the setup make + + align:start position:0% +healthy okay do does the setup make + + + align:start position:0% +healthy okay do does the setup make +sense + + align:start position:0% + + + + align:start position:0% + +yeah oh uh question was are the false + + align:start position:0% +yeah oh uh question was are the false + + + align:start position:0% +yeah oh uh question was are the false +positives included in the 10% or is the + + align:start position:0% +positives included in the 10% or is the + + + align:start position:0% +positives included in the 10% or is the +10% when you actually have it uh so this + + align:start position:0% +10% when you actually have it uh so this + + + align:start position:0% +10% when you actually have it uh so this +10% is you know conditioned on being + + align:start position:0% +10% is you know conditioned on being + + + align:start position:0% +10% is you know conditioned on being +sick okay the conditional probability + + align:start position:0% +sick okay the conditional probability + + + align:start position:0% +sick okay the conditional probability +that it gets it wrong is + + align:start position:0% +that it gets it wrong is + + + align:start position:0% +that it gets it wrong is +10% and the false positive rate is + + align:start position:0% +10% and the false positive rate is + + + align:start position:0% +10% and the false positive rate is +conditioned on being oh sorry false + + align:start position:0% +conditioned on being oh sorry false + + + align:start position:0% +conditioned on being oh sorry false +negative is conditioned on being healthy + + align:start position:0% +negative is conditioned on being healthy + + + align:start position:0% +negative is conditioned on being healthy +false positive is conditioned on being + + align:start position:0% +false positive is conditioned on being + + + align:start position:0% +false positive is conditioned on being +sick + + align:start position:0% +sick + + + align:start position:0% +sick +no no positive positive is sick yeah it + + align:start position:0% +no no positive positive is sick yeah it + + + align:start position:0% +no no positive positive is sick yeah it +was right the first time sorry I'm I'm + + align:start position:0% +was right the first time sorry I'm I'm + + + align:start position:0% +was right the first time sorry I'm I'm +confused uh yeah so these are both + + align:start position:0% +confused uh yeah so these are both + + + align:start position:0% +confused uh yeah so these are both +talking about conditional probabilities + + align:start position:0% +talking about conditional probabilities + + + align:start position:0% +talking about conditional probabilities +okay conditioned on being healthy or + + align:start position:0% +okay conditioned on being healthy or + + + align:start position:0% +okay conditioned on being healthy or +sick what's the probability that the + + align:start position:0% +sick what's the probability that the + + + align:start position:0% +sick what's the probability that the +test is accurate or wrong + + align:start position:0% + + + + align:start position:0% + +okay so let's define some + + align:start position:0% +okay so let's define some + + + align:start position:0% +okay so let's define some +events let's say that H is you know + + align:start position:0% + + + + align:start position:0% + +healthy uh and S can be its + + align:start position:0% + + + + align:start position:0% + +complement + + align:start position:0% +complement + + + align:start position:0% +complement +sick uh plus is going to be positive + + align:start position:0% + + + + align:start position:0% + +result and minus is going to be a + + align:start position:0% +result and minus is going to be a + + + align:start position:0% +result and minus is going to be a +negative + + align:start position:0% + + + + align:start position:0% + +result + + align:start position:0% + + + + align:start position:0% + +okay so suppose I take this covid test + + align:start position:0% +okay so suppose I take this covid test + + + align:start position:0% +okay so suppose I take this covid test +and it comes out + + align:start position:0% +and it comes out + + + align:start position:0% +and it comes out +positive okay what's the probability + + align:start position:0% +positive okay what's the probability + + + align:start position:0% +positive okay what's the probability +that I have + + align:start position:0% + + + + align:start position:0% + +covid so first what is the probability + + align:start position:0% +covid so first what is the probability + + + align:start position:0% +covid so first what is the probability +that we're trying to compute + + align:start position:0% + + + + align:start position:0% + +yeah probability of + + align:start position:0% + + + + align:start position:0% + +s + + align:start position:0% + + + + align:start position:0% + +unconditionally yeah so s given positive + + align:start position:0% +unconditionally yeah so s given positive + + + align:start position:0% +unconditionally yeah so s given positive +right the unconditional probability of s + + align:start position:0% +right the unconditional probability of s + + + align:start position:0% +right the unconditional probability of s +is just 10% by assumption okay what + + align:start position:0% +is just 10% by assumption okay what + + + align:start position:0% +is just 10% by assumption okay what +we're actually looking for is the + + align:start position:0% +we're actually looking for is the + + + align:start position:0% +we're actually looking for is the +probability of uh probability that I'm + + align:start position:0% +probability of uh probability that I'm + + + align:start position:0% +probability of uh probability that I'm +sick given that I tested positive okay + + align:start position:0% +sick given that I tested positive okay + + + align:start position:0% +sick given that I tested positive okay +because that's the observation that we + + align:start position:0% +because that's the observation that we + + + align:start position:0% +because that's the observation that we +made okay so how would we compute + + align:start position:0% + + + + align:start position:0% + +this well let's do the same thing we + + align:start position:0% +this well let's do the same thing we + + + align:start position:0% +this well let's do the same thing we +just did over + + align:start position:0% + + + + align:start position:0% + +here let's look at the ratio of this + + align:start position:0% +here let's look at the ratio of this + + + align:start position:0% +here let's look at the ratio of this +probability to its + + align:start position:0% +probability to its + + + align:start position:0% +probability to its +complement + + align:start position:0% +complement + + + align:start position:0% +complement +okay and and applies apply base + + align:start position:0% +okay and and applies apply base + + + align:start position:0% +okay and and applies apply base +rule so we're going to flip this uh + + align:start position:0% +rule so we're going to flip this uh + + + align:start position:0% +rule so we're going to flip this uh +conditional + + align:start position:0% +conditional + + + align:start position:0% +conditional +here positive given sick times + + align:start position:0% +here positive given sick times + + + align:start position:0% +here positive given sick times +probability of + + align:start position:0% +probability of + + + align:start position:0% +probability of +sick divided by probability of positive + + align:start position:0% +sick divided by probability of positive + + + align:start position:0% +sick divided by probability of positive +given + + align:start position:0% +given + + + align:start position:0% +given +healthy times probability of + + align:start position:0% + + + + align:start position:0% + +healthy + + align:start position:0% +healthy + + + align:start position:0% +healthy +okay now those four probabilities are + + align:start position:0% +okay now those four probabilities are + + + align:start position:0% +okay now those four probabilities are +probab that we know okay what are + + align:start position:0% + + + + align:start position:0% + +they what's the probability of plus + + align:start position:0% +they what's the probability of plus + + + align:start position:0% +they what's the probability of plus +given that I'm + + align:start position:0% + + + + align:start position:0% + +sick + + align:start position:0% +sick + + + align:start position:0% +sick +yeah yeah + + align:start position:0% +yeah yeah + + + align:start position:0% +yeah yeah +90% so let's write that as 0. + + align:start position:0% + + + + align:start position:0% + +n what's the uh prior probability that + + align:start position:0% +n what's the uh prior probability that + + + align:start position:0% +n what's the uh prior probability that +I'm sick + + align:start position:0% + + + + align:start position:0% + +yeah 10 + + align:start position:0% + + + + align:start position:0% + +10% and now what's the probability of a + + align:start position:0% +10% and now what's the probability of a + + + align:start position:0% +10% and now what's the probability of a +positive result condition on being + + align:start position:0% + + + + align:start position:0% + +healthy + + align:start position:0% +healthy + + + align:start position:0% +healthy +yeah yeah that's the false positive + + align:start position:0% + + + + align:start position:0% + +rate3 times and what's the probability + + align:start position:0% +rate3 times and what's the probability + + + align:start position:0% +rate3 times and what's the probability +that I'm healthy the prior probility of + + align:start position:0% +that I'm healthy the prior probility of + + + align:start position:0% +that I'm healthy the prior probility of +I'm + + align:start position:0% + + + + align:start position:0% + +healthy well that's just going to be the + + align:start position:0% +healthy well that's just going to be the + + + align:start position:0% +healthy well that's just going to be the +complement of the uh the event that I'm + + align:start position:0% +complement of the uh the event that I'm + + + align:start position:0% +complement of the uh the event that I'm +sick so that's going to + + align:start position:0% +sick so that's going to + + + align:start position:0% +sick so that's going to +be. + + align:start position:0% +be. + + + align:start position:0% +be. +n okay so these NS + + align:start position:0% +n okay so these NS + + + align:start position:0% +n okay so these NS +cancel this is going to be + + align:start position:0% + + + + align:start position:0% + +1/3 okay so I am 1/3 as likely to be + + align:start position:0% +1/3 okay so I am 1/3 as likely to be + + + align:start position:0% +1/3 okay so I am 1/3 as likely to be +sick as healthy so the probability that + + align:start position:0% +sick as healthy so the probability that + + + align:start position:0% +sick as healthy so the probability that +I'm sick condition on getting the + + align:start position:0% +I'm sick condition on getting the + + + align:start position:0% +I'm sick condition on getting the +positive result is actually only one and + + align:start position:0% +positive result is actually only one and + + + align:start position:0% +positive result is actually only one and +four + + align:start position:0% +four + + + align:start position:0% +four +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so probability s given + + align:start position:0% +so probability s given + + + align:start position:0% +so probability s given +plus equals + + align:start position:0% + + + + align:start position:0% + +1/4 does that make sense to + + align:start position:0% +1/4 does that make sense to + + + align:start position:0% +1/4 does that make sense to +everybody so it might seem a little bit + + align:start position:0% +everybody so it might seem a little bit + + + align:start position:0% +everybody so it might seem a little bit +weird right like uh uh you know this + + align:start position:0% +weird right like uh uh you know this + + + align:start position:0% +weird right like uh uh you know this +this test is a pretty good one right + + align:start position:0% +this test is a pretty good one right + + + align:start position:0% +this test is a pretty good one right +like it's usually giving the right + + align:start position:0% +like it's usually giving the right + + + align:start position:0% +like it's usually giving the right +answer but you know I took the test I + + align:start position:0% +answer but you know I took the test I + + + align:start position:0% +answer but you know I took the test I +got a positive result but I'm still + + align:start position:0% +got a positive result but I'm still + + + align:start position:0% +got a positive result but I'm still +probably healthy why is + + align:start position:0% + + + + align:start position:0% + +that can anybody explain what's going on + + align:start position:0% +that can anybody explain what's going on + + + align:start position:0% +that can anybody explain what's going on +here + + align:start position:0% + + + + align:start position:0% + +yeah yeah exactly so that there's a very + + align:start position:0% +yeah yeah exactly so that there's a very + + + align:start position:0% +yeah yeah exactly so that there's a very +slim chance that I'd Co to begin with so + + align:start position:0% +slim chance that I'd Co to begin with so + + + align:start position:0% +slim chance that I'd Co to begin with so +it's actually much higher now that I've + + align:start position:0% +it's actually much higher now that I've + + + align:start position:0% +it's actually much higher now that I've +got a positive result but the uh the the + + align:start position:0% +got a positive result but the uh the the + + + align:start position:0% +got a positive result but the uh the the +prior was kind of overwhelmingly in + + align:start position:0% +prior was kind of overwhelmingly in + + + align:start position:0% +prior was kind of overwhelmingly in +favor of being healthy and so it's still + + align:start position:0% +favor of being healthy and so it's still + + + align:start position:0% +favor of being healthy and so it's still +you know very likely that I'm healthy + + align:start position:0% +you know very likely that I'm healthy + + + align:start position:0% +you know very likely that I'm healthy +just you know slightly less + + align:start position:0% +just you know slightly less + + + align:start position:0% +just you know slightly less +so okay so often people kind of + + align:start position:0% +so okay so often people kind of + + + align:start position:0% +so okay so often people kind of +underestimate the uh uh the impact of + + align:start position:0% +underestimate the uh uh the impact of + + + align:start position:0% +underestimate the uh uh the impact of +the prior in this way okay uh of course + + align:start position:0% +the prior in this way okay uh of course + + + align:start position:0% +the prior in this way okay uh of course +in the real world you generally don't uh + + align:start position:0% +in the real world you generally don't uh + + + align:start position:0% +in the real world you generally don't uh +do this so if you get a positive result + + align:start position:0% +do this so if you get a positive result + + + align:start position:0% +do this so if you get a positive result +uh you can be more confident in it + + align:start position:0% +uh you can be more confident in it + + + align:start position:0% +uh you can be more confident in it +because you know normally you only test + + align:start position:0% +because you know normally you only test + + + align:start position:0% +because you know normally you only test +when you have symptoms right so the + + align:start position:0% +when you have symptoms right so the + + + align:start position:0% +when you have symptoms right so the +probability that you uh uh that you're + + align:start position:0% +probability that you uh uh that you're + + + align:start position:0% +probability that you uh uh that you're +sick given that you tested positive and + + align:start position:0% +sick given that you tested positive and + + + align:start position:0% +sick given that you tested positive and +you have symptoms that's probably going + + align:start position:0% +you have symptoms that's probably going + + + align:start position:0% +you have symptoms that's probably going +to be much higher than + + align:start position:0% +to be much higher than + + + align:start position:0% +to be much higher than +1/4 + + align:start position:0% + + + + align:start position:0% + +okay are people happy with + + align:start position:0% +okay are people happy with + + + align:start position:0% +okay are people happy with +that yeah + + align:start position:0% +that yeah + + + align:start position:0% +that yeah +okay why don't we look at another + + align:start position:0% +okay why don't we look at another + + + align:start position:0% +okay why don't we look at another +interesting application called Simpsons + + align:start position:0% +interesting application called Simpsons + + + align:start position:0% +interesting application called Simpsons +paradox + + align:start position:0% + + + + align:start position:0% + +okay so there's actually kind of a funny + + align:start position:0% +okay so there's actually kind of a funny + + + align:start position:0% +okay so there's actually kind of a funny +story behind this one uh so about 50 + + align:start position:0% +story behind this one uh so about 50 + + + align:start position:0% +story behind this one uh so about 50 +years ago uh Berkeley UC Berkeley got + + align:start position:0% +years ago uh Berkeley UC Berkeley got + + + align:start position:0% +years ago uh Berkeley UC Berkeley got +sued right because uh you know that it + + align:start position:0% +sued right because uh you know that it + + + align:start position:0% +sued right because uh you know that it +was claimed that they were being very + + align:start position:0% +was claimed that they were being very + + + align:start position:0% +was claimed that they were being very +sexist in their admissions + + align:start position:0% +sexist in their admissions + + + align:start position:0% +sexist in their admissions +policies um and + + align:start position:0% +policies um and + + + align:start position:0% +policies um and +uh you know the + + align:start position:0% +uh you know the + + + align:start position:0% +uh you know the +claim was that the admissions rate was + + align:start position:0% +claim was that the admissions rate was + + + align:start position:0% +claim was that the admissions rate was +much higher for men than it was for + + align:start position:0% +much higher for men than it was for + + + align:start position:0% +much higher for men than it was for +women right so you know that's that's + + align:start position:0% +women right so you know that's that's + + + align:start position:0% +women right so you know that's that's +clearly bad right but then Berkeley + + align:start position:0% +clearly bad right but then Berkeley + + + align:start position:0% +clearly bad right but then Berkeley +counter claimed by saying that if you + + align:start position:0% +counter claimed by saying that if you + + + align:start position:0% +counter claimed by saying that if you +look at each individual Department it's + + align:start position:0% +look at each individual Department it's + + + align:start position:0% +look at each individual Department it's +actually the opposite like women are + + align:start position:0% +actually the opposite like women are + + + align:start position:0% +actually the opposite like women are +being admitted uh with much higher rates + + align:start position:0% +being admitted uh with much higher rates + + + align:start position:0% +being admitted uh with much higher rates +than + + align:start position:0% +than + + + align:start position:0% +than +men right so + + align:start position:0% +men right so + + + align:start position:0% +men right so +um what's going on was somebody lying + + align:start position:0% +um what's going on was somebody lying + + + align:start position:0% +um what's going on was somebody lying +can these both be true + + align:start position:0% + + + + align:start position:0% + +any + + align:start position:0% + + + + align:start position:0% + +ideas + + align:start position:0% + + + + align:start position:0% + +yeah yeah exactly so the uh the the + + align:start position:0% +yeah yeah exactly so the uh the the + + + align:start position:0% +yeah yeah exactly so the uh the the +observation right was that the sizes of + + align:start position:0% +observation right was that the sizes of + + + align:start position:0% +observation right was that the sizes of +the Departments could be very different + + align:start position:0% +the Departments could be very different + + + align:start position:0% +the Departments could be very different +right and what + + align:start position:0% + + + + align:start position:0% + +else + + align:start position:0% + + + + align:start position:0% + +yeah yeah so the the the admissions + + align:start position:0% +yeah yeah so the the the admissions + + + align:start position:0% +yeah yeah so the the the admissions +rates like the the the overall + + align:start position:0% +rates like the the the overall + + + align:start position:0% +rates like the the the overall +admissions rates for the Departments can + + align:start position:0% +admissions rates for the Departments can + + + align:start position:0% +admissions rates for the Departments can +also be very different right and so you + + align:start position:0% +also be very different right and so you + + + align:start position:0% +also be very different right and so you +know maybe you know there's some + + align:start position:0% +know maybe you know there's some + + + align:start position:0% +know maybe you know there's some +departments like you know let's let's + + align:start position:0% +departments like you know let's let's + + + align:start position:0% +departments like you know let's let's +take a look at a very simple example + + align:start position:0% +take a look at a very simple example + + + align:start position:0% +take a look at a very simple example +okay so suppose we have two departments + + align:start position:0% +okay so suppose we have two departments + + + align:start position:0% +okay so suppose we have two departments +e and + + align:start position:0% +e and + + + align:start position:0% +e and +CS + + align:start position:0% +CS + + + align:start position:0% +CS +okay right uh and you + + align:start position:0% +okay right uh and you + + + align:start position:0% +okay right uh and you +know maybe both of them mildly favor + + align:start position:0% +know maybe both of them mildly favor + + + align:start position:0% +know maybe both of them mildly favor +women okay but uh uh you know one of + + align:start position:0% +women okay but uh uh you know one of + + + align:start position:0% +women okay but uh uh you know one of +them is much more popular with men one + + align:start position:0% +them is much more popular with men one + + + align:start position:0% +them is much more popular with men one +of them is much more popular with women + + align:start position:0% +of them is much more popular with women + + + align:start position:0% +of them is much more popular with women +and they have very different admissions + + align:start position:0% +and they have very different admissions + + + align:start position:0% +and they have very different admissions +rates you know + + align:start position:0% +rates you know + + + align:start position:0% +rates you know +generally + + align:start position:0% +generally + + + align:start position:0% +generally +okay so + + align:start position:0% +okay so + + + align:start position:0% +okay so +maybe uh we have a 100 men and 100 women + + align:start position:0% +maybe uh we have a 100 men and 100 women + + + align:start position:0% +maybe uh we have a 100 men and 100 women +applying to you know this two Department + + align:start position:0% +applying to you know this two Department + + + align:start position:0% +applying to you know this two Department +UC + + align:start position:0% +UC + + + align:start position:0% +UC +Berkeley + + align:start position:0% +Berkeley + + + align:start position:0% +Berkeley +okay and uh maybe we have + + align:start position:0% +okay and uh maybe we have + + + align:start position:0% +okay and uh maybe we have +99 uh women and one man apply to + + align:start position:0% +99 uh women and one man apply to + + + align:start position:0% +99 uh women and one man apply to +Cs and in we it's the opposite one woman + + align:start position:0% +Cs and in we it's the opposite one woman + + + align:start position:0% +Cs and in we it's the opposite one woman +and + + align:start position:0% +and + + + align:start position:0% +and + + align:start position:0% + + + align:start position:0% +men + + align:start position:0% + + + + align:start position:0% + +okay and + + align:start position:0% +okay and + + + align:start position:0% +okay and +maybe + + align:start position:0% +maybe + + + align:start position:0% +maybe +uh in CS we're a bunch of snobs right we + + align:start position:0% +uh in CS we're a bunch of snobs right we + + + align:start position:0% +uh in CS we're a bunch of snobs right we +we hate everybody we take one + + align:start position:0% +we hate everybody we take one + + + align:start position:0% +we hate everybody we take one +applicant okay so maybe we take you know + + align:start position:0% +applicant okay so maybe we take you know + + + align:start position:0% +applicant okay so maybe we take you know +one woman + + align:start position:0% +one woman + + + align:start position:0% +one woman +is + + align:start position:0% +is + + + align:start position:0% +is +accepted everybody else is rejected + + align:start position:0% +accepted everybody else is rejected + + + align:start position:0% +accepted everybody else is rejected +okay uh and dou on the other hand has no + + align:start position:0% +okay uh and dou on the other hand has no + + + align:start position:0% +okay uh and dou on the other hand has no +standards at all they'll just take + + align:start position:0% +standards at all they'll just take + + + align:start position:0% +standards at all they'll just take +anybody with a pulse uh but + + align:start position:0% +anybody with a pulse uh but + + + align:start position:0% +anybody with a pulse uh but +unfortunately one of these men is dead + + align:start position:0% +unfortunately one of these men is dead + + + align:start position:0% +unfortunately one of these men is dead +so uh you know they take one woman and + + align:start position:0% +so uh you know they take one woman and + + + align:start position:0% +so uh you know they take one woman and + + align:start position:0% + + + align:start position:0% +men + + align:start position:0% + + + + align:start position:0% + +okay so now if you look at the + + align:start position:0% +okay so now if you look at the + + + align:start position:0% +okay so now if you look at the +individual Department's admissions rates + + align:start position:0% +individual Department's admissions rates + + + align:start position:0% +individual Department's admissions rates +right + + align:start position:0% +right + + + align:start position:0% +right +uh CS has accepted a woman right so + + align:start position:0% +uh CS has accepted a woman right so + + + align:start position:0% +uh CS has accepted a woman right so +their their admissions rate for women is + + align:start position:0% +their their admissions rate for women is + + + align:start position:0% +their their admissions rate for women is +you know nonzero they haven't accepted + + align:start position:0% +you know nonzero they haven't accepted + + + align:start position:0% +you know nonzero they haven't accepted +any men so they've got a zero admissions + + align:start position:0% +any men so they've got a zero admissions + + + align:start position:0% +any men so they've got a zero admissions +rate for + + align:start position:0% +rate for + + + align:start position:0% +rate for +men so it's higher for + + align:start position:0% +men so it's higher for + + + align:start position:0% +men so it's higher for +women right and in E they've accepted + + align:start position:0% +women right and in E they've accepted + + + align:start position:0% +women right and in E they've accepted +all of the women but not all of the men + + align:start position:0% +all of the women but not all of the men + + + align:start position:0% +all of the women but not all of the men +so again it's higher for women but if + + align:start position:0% +so again it's higher for women but if + + + align:start position:0% +so again it's higher for women but if +you look at what's happened overall + + align:start position:0% +you look at what's happened overall + + + align:start position:0% +you look at what's happened overall +right we've got two women being accepted + + align:start position:0% +right we've got two women being accepted + + + align:start position:0% +right we've got two women being accepted +and 98 men + + align:start position:0% + + + + align:start position:0% + +right so you can kind of argue that you + + align:start position:0% +right so you can kind of argue that you + + + align:start position:0% +right so you can kind of argue that you +know rather than being a problem with + + align:start position:0% +know rather than being a problem with + + + align:start position:0% +know rather than being a problem with +the + + align:start position:0% +the + + + align:start position:0% +the +university uh or or the Departments it's + + align:start position:0% +university uh or or the Departments it's + + + align:start position:0% +university uh or or the Departments it's +kind of more of a systemic problem like + + align:start position:0% +kind of more of a systemic problem like + + + align:start position:0% +kind of more of a systemic problem like +uh you know maybe they're you know + + align:start position:0% +uh you know maybe they're you know + + + align:start position:0% +uh you know maybe they're you know +encouraging men and women to apply to uh + + align:start position:0% +encouraging men and women to apply to uh + + + align:start position:0% +encouraging men and women to apply to uh +different departments at different rates + + align:start position:0% +different departments at different rates + + + align:start position:0% +different departments at different rates +and uh you know it's all a bit messy and + + align:start position:0% +and uh you know it's all a bit messy and + + + align:start position:0% +and uh you know it's all a bit messy and +uh you know also this is 50 years ago so + + align:start position:0% +uh you know also this is 50 years ago so + + + align:start position:0% +uh you know also this is 50 years ago so +you know they only really considered men + + align:start position:0% +you know they only really considered men + + + align:start position:0% +you know they only really considered men +and women women didn't really you know + + align:start position:0% +and women women didn't really you know + + + align:start position:0% +and women women didn't really you know +consider anybody who you know identified + + align:start position:0% +consider anybody who you know identified + + + align:start position:0% +consider anybody who you know identified +as anything else but you know we're not + + align:start position:0% +as anything else but you know we're not + + + align:start position:0% +as anything else but you know we're not +saying anything about that this is just + + align:start position:0% +saying anything about that this is just + + + align:start position:0% +saying anything about that this is just +kind of uh to illustrate the math so + + align:start position:0% +kind of uh to illustrate the math so + + + align:start position:0% +kind of uh to illustrate the math so +hopefully it's not terribly + + align:start position:0% +hopefully it's not terribly + + + align:start position:0% +hopefully it's not terribly +offensive but yeah uh even though for + + align:start position:0% +offensive but yeah uh even though for + + + align:start position:0% +offensive but yeah uh even though for +each department the the women are doing + + align:start position:0% +each department the the women are doing + + + align:start position:0% +each department the the women are doing +better than men the men are doing much + + align:start position:0% +better than men the men are doing much + + + align:start position:0% +better than men the men are doing much +better overall okay so that's what we + + align:start position:0% +better overall okay so that's what we + + + align:start position:0% +better overall okay so that's what we +call simp Simpsons + + align:start position:0% +call simp Simpsons + + + align:start position:0% +call simp Simpsons +Paradox does anybody have any question + + align:start position:0% +Paradox does anybody have any question + + + align:start position:0% +Paradox does anybody have any question +questions about + + align:start position:0% + + + + align:start position:0% + +that + + align:start position:0% +that + + + align:start position:0% +that +okay so last + + align:start position:0% + + + + align:start position:0% + +example has anybody seen the dragon + + align:start position:0% +example has anybody seen the dragon + + + align:start position:0% +example has anybody seen the dragon +prins couple of hands okay well so last + + align:start position:0% +prins couple of hands okay well so last + + + align:start position:0% +prins couple of hands okay well so last +example uh suppose a cake has gone + + align:start position:0% +example uh suppose a cake has gone + + + align:start position:0% +example uh suppose a cake has gone +missing from the bakery and and uh you + + align:start position:0% +missing from the bakery and and uh you + + + align:start position:0% +missing from the bakery and and uh you +know barus the baker has has a prime + + align:start position:0% +know barus the baker has has a prime + + + align:start position:0% +know barus the baker has has a prime +suspect right he thinks that Prince ezin + + align:start position:0% +suspect right he thinks that Prince ezin + + + align:start position:0% +suspect right he thinks that Prince ezin +stole the + + align:start position:0% +stole the + + + align:start position:0% +stole the +cake + + align:start position:0% +cake + + + align:start position:0% +cake +uh and you know he wants to present + + align:start position:0% +uh and you know he wants to present + + + align:start position:0% +uh and you know he wants to present +evidence to the + + align:start position:0% +evidence to the + + + align:start position:0% +evidence to the +king he would like to tell the king that + + align:start position:0% +king he would like to tell the king that + + + align:start position:0% +king he would like to tell the king that +you know this this uh this deviant is + + align:start position:0% +you know this this uh this deviant is + + + align:start position:0% +you know this this uh this deviant is +always stealing jelly Tarts from my + + align:start position:0% +always stealing jelly Tarts from my + + + align:start position:0% +always stealing jelly Tarts from my +bakery you know that makes it much more + + align:start position:0% +bakery you know that makes it much more + + + align:start position:0% +bakery you know that makes it much more +likely that he stole the cake right like + + align:start position:0% +likely that he stole the cake right like + + + align:start position:0% +likely that he stole the cake right like +jelly tart thieves are you know 10 times + + align:start position:0% +jelly tart thieves are you know 10 times + + + align:start position:0% +jelly tart thieves are you know 10 times +as likely as randos to to steal cakes + + align:start position:0% +as likely as randos to to steal cakes + + + align:start position:0% +as likely as randos to to steal cakes +okay it seems Seems fairly reasonable + + align:start position:0% +okay it seems Seems fairly reasonable + + + align:start position:0% +okay it seems Seems fairly reasonable +right does does anybody think that this + + align:start position:0% +right does does anybody think that this + + + align:start position:0% +right does does anybody think that this +is a good reason to uh admit the jelly + + align:start position:0% +is a good reason to uh admit the jelly + + + align:start position:0% +is a good reason to uh admit the jelly +tart thevery into uh into + + align:start position:0% +tart thevery into uh into + + + align:start position:0% +tart thevery into uh into +evidence who thinks that it's not a + + align:start position:0% +evidence who thinks that it's not a + + + align:start position:0% +evidence who thinks that it's not a +compelling + + align:start position:0% +compelling + + + align:start position:0% +compelling +reason well who has no + + align:start position:0% +reason well who has no + + + align:start position:0% +reason well who has no +idea morans okay so uh maybe Prince + + align:start position:0% +idea morans okay so uh maybe Prince + + + align:start position:0% +idea morans okay so uh maybe Prince +cen's counter claim + + align:start position:0% +cen's counter claim + + + align:start position:0% +cen's counter claim +is well if you look at you know all + + align:start position:0% +is well if you look at you know all + + + align:start position:0% +is well if you look at you know all +jelly tart thieves you know only one in + + align:start position:0% +jelly tart thieves you know only one in + + + align:start position:0% +jelly tart thieves you know only one in +say 2500 of them actually go on to Steel + + align:start position:0% +say 2500 of them actually go on to Steel + + + align:start position:0% +say 2500 of them actually go on to Steel +cakes so like you know even though the + + align:start position:0% +cakes so like you know even though the + + + align:start position:0% +cakes so like you know even though the +probability of you know being a cake + + align:start position:0% +probability of you know being a cake + + + align:start position:0% +probability of you know being a cake +thief has you know increased + + align:start position:0% +thief has you know increased + + + align:start position:0% +thief has you know increased +dramatically from from the the Baseline + + align:start position:0% +dramatically from from the the Baseline + + + align:start position:0% +dramatically from from the the Baseline +in terms of like a multiplicative Factor + + align:start position:0% +in terms of like a multiplicative Factor + + + align:start position:0% +in terms of like a multiplicative Factor +it can't actually have increased very + + align:start position:0% +it can't actually have increased very + + + align:start position:0% +it can't actually have increased very +much because you know it went from 1 + + align:start position:0% +much because you know it went from 1 + + + align:start position:0% +much because you know it went from 1 +125,000 to 1 + + align:start position:0% +125,000 to 1 + + + align:start position:0% +125,000 to 1 +12500 right so the uh the probative + + align:start position:0% +12500 right so the uh the probative + + + align:start position:0% +12500 right so the uh the probative +value here is you know essentially zero + + align:start position:0% +value here is you know essentially zero + + + align:start position:0% +value here is you know essentially zero +right you're you're trying to prove + + align:start position:0% +right you're you're trying to prove + + + align:start position:0% +right you're you're trying to prove +guilt Beyond A Reasonable Doubt + + align:start position:0% +guilt Beyond A Reasonable Doubt + + + align:start position:0% +guilt Beyond A Reasonable Doubt +right and so a 1 in 2500 chance increase + + align:start position:0% +right and so a 1 in 2500 chance increase + + + align:start position:0% +right and so a 1 in 2500 chance increase +is kind of negligible but on the other + + align:start position:0% +is kind of negligible but on the other + + + align:start position:0% +is kind of negligible but on the other +hand you know if you admit this into + + align:start position:0% +hand you know if you admit this into + + + align:start position:0% +hand you know if you admit this into +evidence the king is going to be biased + + align:start position:0% +evidence the king is going to be biased + + + align:start position:0% +evidence the king is going to be biased +against ezren right he's going to be + + align:start position:0% +against ezren right he's going to be + + + align:start position:0% +against ezren right he's going to be +like oh this kid's a thief this is + + align:start position:0% +like oh this kid's a thief this is + + + align:start position:0% +like oh this kid's a thief this is +terrible we got to punish him right + + align:start position:0% +terrible we got to punish him right + + + align:start position:0% +terrible we got to punish him right +regardless of whether he stole the + + align:start position:0% + + + + align:start position:0% + +cake so uh so who's right is is the + + align:start position:0% +cake so uh so who's right is is the + + + align:start position:0% +cake so uh so who's right is is the +baker right or is the uh is the suspect + + align:start position:0% + + + + align:start position:0% + +right who thinks Baker is + + align:start position:0% + + + + align:start position:0% + +right who think suspect is + + align:start position:0% +right who think suspect is + + + align:start position:0% +right who think suspect is +right who thinks + + align:start position:0% +right who thinks + + + align:start position:0% +right who thinks +[Laughter] + + align:start position:0% +[Laughter] + + + align:start position:0% +[Laughter] +neither yeah I've got a few HS + + align:start position:0% +neither yeah I've got a few HS + + + align:start position:0% +neither yeah I've got a few HS +okay so + + align:start position:0% +okay so + + + align:start position:0% +okay so +um well both parties here are trying to + + align:start position:0% +um well both parties here are trying to + + + align:start position:0% +um well both parties here are trying to +reason + + align:start position:0% +reason + + + align:start position:0% +reason +about uh a conditional + + align:start position:0% +about uh a conditional + + + align:start position:0% +about uh a conditional +probability okay what is that + + align:start position:0% +probability okay what is that + + + align:start position:0% +probability okay what is that +conditional + + align:start position:0% + + + + align:start position:0% + +probability + + align:start position:0% + + + + align:start position:0% + +anybody well maybe we should start by + + align:start position:0% +anybody well maybe we should start by + + + align:start position:0% +anybody well maybe we should start by +writing out some + + align:start position:0% +writing out some + + + align:start position:0% +writing out some +events + + align:start position:0% +events + + + align:start position:0% +events +so let's let J be the event + + align:start position:0% +so let's let J be the event + + + align:start position:0% +so let's let J be the event +suspect + + align:start position:0% +suspect + + + align:start position:0% +suspect +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +steals jelly tarts + + align:start position:0% + + + + align:start position:0% + +uh C can be the event suspect steals + + align:start position:0% + + + + align:start position:0% + +cake and X can be the event cake was + + align:start position:0% + + + + align:start position:0% + +stolen + + align:start position:0% +stolen + + + align:start position:0% +stolen +okay so both the Baker and the suspect + + align:start position:0% +okay so both the Baker and the suspect + + + align:start position:0% +okay so both the Baker and the suspect +we making claims about conditional + + align:start position:0% +we making claims about conditional + + + align:start position:0% +we making claims about conditional +probabilities what specific conditional + + align:start position:0% +probabilities what specific conditional + + + align:start position:0% +probabilities what specific conditional +probability in terms of these events + + align:start position:0% +probability in terms of these events + + + align:start position:0% +probability in terms of these events +were they making claims + + align:start position:0% + + + + align:start position:0% + +about + + align:start position:0% +about + + + align:start position:0% +about +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +sorry uh repeat the assertions oh the + + align:start position:0% +sorry uh repeat the assertions oh the + + + align:start position:0% +sorry uh repeat the assertions oh the +assumptions uh so the assumptions were + + align:start position:0% +assumptions uh so the assumptions were + + + align:start position:0% +assumptions uh so the assumptions were +right that a cake has gone missing from + + align:start position:0% +right that a cake has gone missing from + + + align:start position:0% +right that a cake has gone missing from +the bakery the baker has a prime suspect + + align:start position:0% +the bakery the baker has a prime suspect + + + align:start position:0% +the bakery the baker has a prime suspect +okay and the the Baker wants to admit + + align:start position:0% +okay and the the Baker wants to admit + + + align:start position:0% +okay and the the Baker wants to admit +into evidence that this suspect is + + align:start position:0% +into evidence that this suspect is + + + align:start position:0% +into evidence that this suspect is +always stealing jelly Tarts okay and the + + align:start position:0% +always stealing jelly Tarts okay and the + + + align:start position:0% +always stealing jelly Tarts okay and the +reasoning is that uh you know jelly tart + + align:start position:0% +reasoning is that uh you know jelly tart + + + align:start position:0% +reasoning is that uh you know jelly tart +thieves are much more likely to steal + + align:start position:0% +thieves are much more likely to steal + + + align:start position:0% +thieves are much more likely to steal +cakes than you know random other + + align:start position:0% +cakes than you know random other + + + align:start position:0% +cakes than you know random other +people okay and the suspect counters by + + align:start position:0% +people okay and the suspect counters by + + + align:start position:0% +people okay and the suspect counters by +saying well sure but like only one in + + align:start position:0% +saying well sure but like only one in + + + align:start position:0% +saying well sure but like only one in +2500 jelly tart thieves is actually a + + align:start position:0% +2500 jelly tart thieves is actually a + + + align:start position:0% +2500 jelly tart thieves is actually a +cake thief right so you know the actual + + align:start position:0% +cake thief right so you know the actual + + + align:start position:0% +cake thief right so you know the actual +increase is less than 1 in + + align:start position:0% +increase is less than 1 in + + + align:start position:0% +increase is less than 1 in + + align:start position:0% + + + align:start position:0% +okay so what are the probabilities that + + align:start position:0% +okay so what are the probabilities that + + + align:start position:0% +okay so what are the probabilities that +they're reasoning about what are the + + align:start position:0% +they're reasoning about what are the + + + align:start position:0% +they're reasoning about what are the +conditional + + align:start position:0% + + + + align:start position:0% + +probabilities yeah + + align:start position:0% + + + + align:start position:0% + +yeah well you're both right sorry it's + + align:start position:0% +yeah well you're both right sorry it's + + + align:start position:0% +yeah well you're both right sorry it's +um geometry they're both trying to + + align:start position:0% +um geometry they're both trying to + + + align:start position:0% +um geometry they're both trying to +reason about probability of C given J + + align:start position:0% +reason about probability of C given J + + + align:start position:0% +reason about probability of C given J +right you know so we're conditioning on + + align:start position:0% +right you know so we're conditioning on + + + align:start position:0% +right you know so we're conditioning on +the suspect having stolen jelly Tarts + + align:start position:0% +the suspect having stolen jelly Tarts + + + align:start position:0% +the suspect having stolen jelly Tarts +and they're both trying to make claims + + align:start position:0% +and they're both trying to make claims + + + align:start position:0% +and they're both trying to make claims +about you know what is the probability + + align:start position:0% +about you know what is the probability + + + align:start position:0% +about you know what is the probability +of C conditioned on + + align:start position:0% + + + + align:start position:0% + +that okay + + align:start position:0% +that okay + + + align:start position:0% +that okay +so well the baker is arguing that + + align:start position:0% +so well the baker is arguing that + + + align:start position:0% +so well the baker is arguing that +probability of C given J divided by + + align:start position:0% +probability of C given J divided by + + + align:start position:0% +probability of C given J divided by +probability of C given not + + align:start position:0% +probability of C given not + + + align:start position:0% +probability of C given not +J is + + align:start position:0% +J is + + + align:start position:0% +J is +high + + align:start position:0% +high + + + align:start position:0% +high +right so you know because this is you + + align:start position:0% +right so you know because this is you + + + align:start position:0% +right so you know because this is you +know about 10 J is very relevant to the + + align:start position:0% +know about 10 J is very relevant to the + + + align:start position:0% +know about 10 J is very relevant to the +case so it should be + + align:start position:0% +case so it should be + + + align:start position:0% +case so it should be +admitted okay uh the suspect is saying + + align:start position:0% +admitted okay uh the suspect is saying + + + align:start position:0% +admitted okay uh the suspect is saying +that + + align:start position:0% +that + + + align:start position:0% +that +probability of C given + + align:start position:0% +probability of C given + + + align:start position:0% +probability of C given +J is low + + align:start position:0% +J is low + + + align:start position:0% +J is low +right so J cannot actually uh + + align:start position:0% +right so J cannot actually uh + + + align:start position:0% +right so J cannot actually uh +dramatically increase the + + align:start position:0% +dramatically increase the + + + align:start position:0% +dramatically increase the +probability right the increase is going + + align:start position:0% +probability right the increase is going + + + align:start position:0% +probability right the increase is going +to be less than this + + align:start position:0% + + + + align:start position:0% + +probability yeah + + align:start position:0% + + + + align:start position:0% + +yeah so that's a good point um so the + + align:start position:0% +yeah so that's a good point um so the + + + align:start position:0% +yeah so that's a good point um so the +the point was that we're we're talking + + align:start position:0% +the point was that we're we're talking + + + align:start position:0% +the point was that we're we're talking +about you know one individual suspect + + align:start position:0% +about you know one individual suspect + + + align:start position:0% +about you know one individual suspect +one individual cake one individual case + + align:start position:0% +one individual cake one individual case + + + align:start position:0% +one individual cake one individual case +right so kind of as we were saying + + align:start position:0% +right so kind of as we were saying + + + align:start position:0% +right so kind of as we were saying +before when we first uh started looking + + align:start position:0% +before when we first uh started looking + + + align:start position:0% +before when we first uh started looking +at rule like you know either it happened + + align:start position:0% +at rule like you know either it happened + + + align:start position:0% +at rule like you know either it happened +or it didn't right like you could say + + align:start position:0% +or it didn't right like you could say + + + align:start position:0% +or it didn't right like you could say +that it doesn't make a whole lot of + + align:start position:0% +that it doesn't make a whole lot of + + + align:start position:0% +that it doesn't make a whole lot of +sense to talk about probabilities right + + align:start position:0% +sense to talk about probabilities right + + + align:start position:0% +sense to talk about probabilities right +but you know you're trying to convince + + align:start position:0% +but you know you're trying to convince + + + align:start position:0% +but you know you're trying to convince +you know the king or a jury or somebody + + align:start position:0% +you know the king or a jury or somebody + + + align:start position:0% +you know the king or a jury or somebody +right um so this is kind of you know + + align:start position:0% +right um so this is kind of you know + + + align:start position:0% +right um so this is kind of you know +similar to when you present DNA evidence + + align:start position:0% +similar to when you present DNA evidence + + + align:start position:0% +similar to when you present DNA evidence +in court or something like that uh like + + align:start position:0% +in court or something like that uh like + + + align:start position:0% +in court or something like that uh like +the fact that there's a match means that + + align:start position:0% +the fact that there's a match means that + + + align:start position:0% +the fact that there's a match means that +there's you know overwhelming + + align:start position:0% +there's you know overwhelming + + + align:start position:0% +there's you know overwhelming +probability that the uh the suspect was + + align:start position:0% +probability that the uh the suspect was + + + align:start position:0% +probability that the uh the suspect was +at the crime scene or something like + + align:start position:0% +at the crime scene or something like + + + align:start position:0% +at the crime scene or something like +that right so like you you do kind of + + align:start position:0% +that right so like you you do kind of + + + align:start position:0% +that right so like you you do kind of +still talk about + + align:start position:0% +still talk about + + + align:start position:0% +still talk about +probabilities uh but you could think of + + align:start position:0% +probabilities uh but you could think of + + + align:start position:0% +probabilities uh but you could think of +it as like you know how confident are + + align:start position:0% +it as like you know how confident are + + + align:start position:0% +it as like you know how confident are +you in the inference that uh that the + + align:start position:0% +you in the inference that uh that the + + + align:start position:0% +you in the inference that uh that the +suspect did something does that make + + align:start position:0% + + + + align:start position:0% + +sense + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so so if you were the judge in this case + + align:start position:0% +so so if you were the judge in this case + + + align:start position:0% +so so if you were the judge in this case +determining what should be presented to + + align:start position:0% +determining what should be presented to + + + align:start position:0% +determining what should be presented to +the + + align:start position:0% +the + + + align:start position:0% +the +king what would your verdict + + align:start position:0% + + + + align:start position:0% + +be do do we allow jelly tart thievery + + align:start position:0% +be do do we allow jelly tart thievery + + + align:start position:0% +be do do we allow jelly tart thievery +into evidence or + + align:start position:0% +into evidence or + + + align:start position:0% +into evidence or +no pardon draw a tree diagram draw a + + align:start position:0% +no pardon draw a tree diagram draw a + + + align:start position:0% +no pardon draw a tree diagram draw a +tree diagram uh well that's not actually + + align:start position:0% +tree diagram uh well that's not actually + + + align:start position:0% +tree diagram uh well that's not actually +necessary anymore we've already figured + + align:start position:0% +necessary anymore we've already figured + + + align:start position:0% +necessary anymore we've already figured +out what the uh probabilities are the uh + + align:start position:0% +out what the uh probabilities are the uh + + + align:start position:0% +out what the uh probabilities are the uh +question is um you know is the probative + + align:start position:0% +question is um you know is the probative + + + align:start position:0% +question is um you know is the probative +value good enough to justify you know + + align:start position:0% +value good enough to justify you know + + + align:start position:0% +value good enough to justify you know +putting it into evidence or is the + + align:start position:0% +putting it into evidence or is the + + + align:start position:0% +putting it into evidence or is the +probative value small enough that the uh + + align:start position:0% +probative value small enough that the uh + + + align:start position:0% +probative value small enough that the uh +bias is going to be more more of a + + align:start position:0% +bias is going to be more more of a + + + align:start position:0% +bias is going to be more more of a +factor + + align:start position:0% + + + + align:start position:0% + +yeah oh + + align:start position:0% + + + + align:start position:0% + +yeah so it it it will not you know + + align:start position:0% +yeah so it it it will not you know + + + align:start position:0% +yeah so it it it will not you know +generally capture the full story and + + align:start position:0% +generally capture the full story and + + + align:start position:0% +generally capture the full story and +this is why you know lawyers in a + + align:start position:0% +this is why you know lawyers in a + + + align:start position:0% +this is why you know lawyers in a +courtroom are you know trying to find + + align:start position:0% +courtroom are you know trying to find + + + align:start position:0% +courtroom are you know trying to find +all kinds of evidence to uh to bolster + + align:start position:0% +all kinds of evidence to uh to bolster + + + align:start position:0% +all kinds of evidence to uh to bolster +their cases so yeah like something like + + align:start position:0% +their cases so yeah like something like + + + align:start position:0% +their cases so yeah like something like +that might be something that the uh the + + align:start position:0% +that might be something that the uh the + + + align:start position:0% +that might be something that the uh the +defense would want to uh would want to + + align:start position:0% +defense would want to uh would want to + + + align:start position:0% +defense would want to uh would want to +present um or the prosecution might be + + align:start position:0% +present um or the prosecution might be + + + align:start position:0% +present um or the prosecution might be +like oh but even though it's an MIT + + align:start position:0% +like oh but even though it's an MIT + + + align:start position:0% +like oh but even though it's an MIT +student like it's an it eecs student who + + align:start position:0% +student like it's an it eecs student who + + + align:start position:0% +student like it's an it eecs student who +do steel cakes all the time + + align:start position:0% +do steel cakes all the time + + + align:start position:0% +do steel cakes all the time +so I'm getting some uh some nods That's + + align:start position:0% +so I'm getting some uh some nods That's + + + align:start position:0% +so I'm getting some uh some nods That's +mildly + + align:start position:0% +mildly + + + align:start position:0% +mildly +[Laughter] + + align:start position:0% +[Laughter] + + + align:start position:0% +[Laughter] +concerning so uh you know like yeah it's + + align:start position:0% +concerning so uh you know like yeah it's + + + align:start position:0% +concerning so uh you know like yeah it's +going to be very difficult to capture + + align:start position:0% +going to be very difficult to capture + + + align:start position:0% +going to be very difficult to capture +the entire picture um for right now + + align:start position:0% +the entire picture um for right now + + + align:start position:0% +the entire picture um for right now +we're just trying to limit the scope to + + align:start position:0% +we're just trying to limit the scope to + + + align:start position:0% +we're just trying to limit the scope to +like these are these are the things that + + align:start position:0% +like these are these are the things that + + + align:start position:0% +like these are these are the things that +are known right we we know that a cake + + align:start position:0% +are known right we we know that a cake + + + align:start position:0% +are known right we we know that a cake +is stolen we know that this suspect + + align:start position:0% +is stolen we know that this suspect + + + align:start position:0% +is stolen we know that this suspect +steals jelly Tarts uh but that's it like + + align:start position:0% +steals jelly Tarts uh but that's it like + + + align:start position:0% +steals jelly Tarts uh but that's it like +we we want to try and figure out you + + align:start position:0% +we we want to try and figure out you + + + align:start position:0% +we we want to try and figure out you +know what the the probative value of + + align:start position:0% +know what the the probative value of + + + align:start position:0% +know what the the probative value of +this evidence is uh just based on + + align:start position:0% +this evidence is uh just based on + + + align:start position:0% +this evidence is uh just based on +those does that make + + align:start position:0% +those does that make + + + align:start position:0% +those does that make +sense so who thinks who thinks the jelly + + align:start position:0% +sense so who thinks who thinks the jelly + + + align:start position:0% +sense so who thinks who thinks the jelly +tart should be + + align:start position:0% +tart should be + + + align:start position:0% +tart should be +admitted who thinks + + align:start position:0% + + + + align:start position:0% + +no okay I'm I'm I'm getting more hands + + align:start position:0% +no okay I'm I'm I'm getting more hands + + + align:start position:0% +no okay I'm I'm I'm getting more hands +this time less extensions okay does + + align:start position:0% +this time less extensions okay does + + + align:start position:0% +this time less extensions okay does +anybody want to say + + align:start position:0% +anybody want to say + + + align:start position:0% +anybody want to say +why yeah + + align:start position:0% + + + + align:start position:0% + +mhm yeah so the the observation rate was + + align:start position:0% +mhm yeah so the the observation rate was + + + align:start position:0% +mhm yeah so the the observation rate was +uh you know the probability of C given + + align:start position:0% +uh you know the probability of C given + + + align:start position:0% +uh you know the probability of C given +not J is also very low right and in fact + + align:start position:0% +not J is also very low right and in fact + + + align:start position:0% +not J is also very low right and in fact +it is much lower than than C given J um + + align:start position:0% +it is much lower than than C given J um + + + align:start position:0% +it is much lower than than C given J um +so that's kind of where this this uh the + + align:start position:0% +so that's kind of where this this uh the + + + align:start position:0% +so that's kind of where this this uh the +the ratio there probability of C given J + + align:start position:0% +the ratio there probability of C given J + + + align:start position:0% +the ratio there probability of C given J +over C given not J is coming from right + + align:start position:0% +over C given not J is coming from right + + + align:start position:0% +over C given not J is coming from right +like uh probability of C given J is 1 + + align:start position:0% +like uh probability of C given J is 1 + + + align:start position:0% +like uh probability of C given J is 1 +and 2500 probability of C given not J is + + align:start position:0% +and 2500 probability of C given not J is + + + align:start position:0% +and 2500 probability of C given not J is +1 and + + align:start position:0% +1 and + + + align:start position:0% +1 and +25,000 right so that's where you're + + align:start position:0% +25,000 right so that's where you're + + + align:start position:0% +25,000 right so that's where you're +getting this factor of + + align:start position:0% +getting this factor of + + + align:start position:0% +getting this factor of +10 so you you agree with the uh the + + align:start position:0% +10 so you you agree with the uh the + + + align:start position:0% +10 so you you agree with the uh the +defense that this should not be ad + + align:start position:0% +defense that this should not be ad + + + align:start position:0% +defense that this should not be ad +admitted into evidence okay does anybody + + align:start position:0% +admitted into evidence okay does anybody + + + align:start position:0% +admitted into evidence okay does anybody +have any Contra + + align:start position:0% + + + + align:start position:0% + +claims + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% + + + + align:start position:0% + +yeah yeah so that's a good point we've + + align:start position:0% +yeah yeah so that's a good point we've + + + align:start position:0% +yeah yeah so that's a good point we've +uh we've kind of forgotten about + + align:start position:0% +uh we've kind of forgotten about + + + align:start position:0% +uh we've kind of forgotten about +something + + align:start position:0% + + + + align:start position:0% + +right a cake was stolen right we don't + + align:start position:0% +right a cake was stolen right we don't + + + align:start position:0% +right a cake was stolen right we don't +care that the probability of cakes being + + align:start position:0% +care that the probability of cakes being + + + align:start position:0% +care that the probability of cakes being +stolen is low it it + + align:start position:0% +stolen is low it it + + + align:start position:0% +stolen is low it it +happened right + + align:start position:0% +happened right + + + align:start position:0% +happened right +so you know we we we don't really care + + align:start position:0% +so you know we we we don't really care + + + align:start position:0% +so you know we we we don't really care +about these probabilities at all what is + + align:start position:0% +about these probabilities at all what is + + + align:start position:0% +about these probabilities at all what is +the actual probability we care + + align:start position:0% + + + + align:start position:0% + +about what we really want is is + + align:start position:0% +about what we really want is is + + + align:start position:0% +about what we really want is is +probability of C given + + align:start position:0% + + + + align:start position:0% + +what + + align:start position:0% + + + + align:start position:0% + +yeah well not that they stole a cake but + + align:start position:0% +yeah well not that they stole a cake but + + + align:start position:0% +yeah well not that they stole a cake but +that a cake was stolen yeah so C given j + + align:start position:0% +that a cake was stolen yeah so C given j + + + align:start position:0% +that a cake was stolen yeah so C given j +and + + align:start position:0% +and + + + align:start position:0% +and +x okay so that's what we really care + + align:start position:0% +x okay so that's what we really care + + + align:start position:0% +x okay so that's what we really care +about right uh that the fact that the + + align:start position:0% +about right uh that the fact that the + + + align:start position:0% +about right uh that the fact that the +cake is stolen is really important right + + align:start position:0% +cake is stolen is really important right + + + align:start position:0% +cake is stolen is really important right +like if + + align:start position:0% +like if + + + align:start position:0% +like if +uh no if you don't know whether the cake + + align:start position:0% +uh no if you don't know whether the cake + + + align:start position:0% +uh no if you don't know whether the cake +is stolen right why are you even having + + align:start position:0% +is stolen right why are you even having + + + align:start position:0% +is stolen right why are you even having +a + + align:start position:0% + + + + align:start position:0% + +trial and as it turns out this + + align:start position:0% +trial and as it turns out this + + + align:start position:0% +trial and as it turns out this +probability is something like + + align:start position:0% + + + + align:start position:0% + +80% jelly tart thieves founded bakeries + + align:start position:0% +80% jelly tart thieves founded bakeries + + + align:start position:0% +80% jelly tart thieves founded bakeries +with missing cakes usually they're the + + align:start position:0% +with missing cakes usually they're the + + + align:start position:0% +with missing cakes usually they're the +guilty + + align:start position:0% + + + + align:start position:0% + +party um + + align:start position:0% +party um + + + align:start position:0% +party um +so yeah I've kind of made this a little + + align:start position:0% +so yeah I've kind of made this a little + + + align:start position:0% +so yeah I've kind of made this a little +bit more palatable but uh this is uh you + + align:start position:0% +bit more palatable but uh this is uh you + + + align:start position:0% +bit more palatable but uh this is uh you +know based on an actual courtroom case + + align:start position:0% +know based on an actual courtroom case + + + align:start position:0% +know based on an actual courtroom case +um like this this is the kind of thing + + align:start position:0% +um like this this is the kind of thing + + + align:start position:0% +um like this this is the kind of thing +that that people uh you know like people + + align:start position:0% +that that people uh you know like people + + + align:start position:0% +that that people uh you know like people +try and use and you know end up misusing + + align:start position:0% +try and use and you know end up misusing + + + align:start position:0% +try and use and you know end up misusing +probabilities and conditional + + align:start position:0% +probabilities and conditional + + + align:start position:0% +probabilities and conditional +probabilities all the time this was + + align:start position:0% +probabilities all the time this was + + + align:start position:0% +probabilities all the time this was +actually from a very high-profile case + + align:start position:0% +actually from a very high-profile case + + + align:start position:0% +actually from a very high-profile case +the OJ Simpson case um where both the + + align:start position:0% +the OJ Simpson case um where both the + + + align:start position:0% +the OJ Simpson case um where both the +defense and the prosecution attorneys + + align:start position:0% +defense and the prosecution attorneys + + + align:start position:0% +defense and the prosecution attorneys +like you know they're supposed to be + + align:start position:0% +like you know they're supposed to be + + + align:start position:0% +like you know they're supposed to be +experts uh but you know they were both + + align:start position:0% +experts uh but you know they were both + + + align:start position:0% +experts uh but you know they were both +making bogus claims about uh about + + align:start position:0% +making bogus claims about uh about + + + align:start position:0% +making bogus claims about uh about +conditional + + align:start position:0% +conditional + + + align:start position:0% +conditional +probabilities uh you know it's it's very + + align:start position:0% +probabilities uh you know it's it's very + + + align:start position:0% +probabilities uh you know it's it's very +easy to make these kinds of mistakes so + + align:start position:0% +easy to make these kinds of mistakes so + + + align:start position:0% +easy to make these kinds of mistakes so +you know fall back on fundamentals uh + + align:start position:0% +you know fall back on fundamentals uh + + + align:start position:0% +you know fall back on fundamentals uh +when you're an adult fall back on the + + align:start position:0% +when you're an adult fall back on the + + + align:start position:0% +when you're an adult fall back on the +fundamentals even if you're not it's + + align:start position:0% +fundamentals even if you're not it's + + + align:start position:0% +fundamentals even if you're not it's +probably a good idea anyway okay uh feel + + align:start position:0% +probably a good idea anyway okay uh feel + + + align:start position:0% +probably a good idea anyway okay uh feel +free to come up if you have any + + align:start position:0% +free to come up if you have any + + + align:start position:0% +free to come up if you have any +questions and uh otherwise we will see + + align:start position:0% +questions and uh otherwise we will see + + + align:start position:0% +questions and uh otherwise we will see +you next week \ No newline at end of file diff --git a/wrEcliDbXQk.txt b/wrEcliDbXQk.txt new file mode 100644 index 0000000000000000000000000000000000000000..53ee5aeabe292d37b4db76faa9da1f13945b8d3d --- /dev/null +++ b/wrEcliDbXQk.txt @@ -0,0 +1,459 @@ +align:start position:0% + +the field of a square pair of coils can + + align:start position:0% +the field of a square pair of coils can + + + align:start position:0% +the field of a square pair of coils can +be found by using the biot-savart law + + align:start position:0% + + + + align:start position:0% + +here are our square coils each with 50 + + align:start position:0% +here are our square coils each with 50 + + + align:start position:0% +here are our square coils each with 50 +turns and sides of length 45 centimeters + + align:start position:0% +turns and sides of length 45 centimeters + + + align:start position:0% +turns and sides of length 45 centimeters +the axial magnetometer probe is mounted + + align:start position:0% +the axial magnetometer probe is mounted + + + align:start position:0% +the axial magnetometer probe is mounted +on this carriage to record the Z + + align:start position:0% +on this carriage to record the Z + + + align:start position:0% +on this carriage to record the Z +component of magnetic field before we + + align:start position:0% +component of magnetic field before we + + + align:start position:0% +component of magnetic field before we +apply current to the coils we have + + align:start position:0% +apply current to the coils we have + + + align:start position:0% +apply current to the coils we have +compensated for the small part of the + + align:start position:0% +compensated for the small part of the + + + align:start position:0% +compensated for the small part of the +Earth's magnetic field that is in the + + align:start position:0% +Earth's magnetic field that is in the + + + align:start position:0% +Earth's magnetic field that is in the +horizontal direction by zeroing the + + align:start position:0% +horizontal direction by zeroing the + + + align:start position:0% +horizontal direction by zeroing the +magnetometer the Earth's magnetic field + + align:start position:0% +magnetometer the Earth's magnetic field + + + align:start position:0% +magnetometer the Earth's magnetic field +is essentially vertical with the + + align:start position:0% +is essentially vertical with the + + + align:start position:0% +is essentially vertical with the +strength of about a half the Gauss and + + align:start position:0% +strength of about a half the Gauss and + + + align:start position:0% +strength of about a half the Gauss and +could contribute a slight error to the + + align:start position:0% +could contribute a slight error to the + + + align:start position:0% +could contribute a slight error to the +measurement if not accounted for a + + align:start position:0% +measurement if not accounted for a + + + align:start position:0% +measurement if not accounted for a +current of two and a half amperes is + + align:start position:0% +current of two and a half amperes is + + + align:start position:0% +current of two and a half amperes is +applied to the coils we have placed the + + align:start position:0% +applied to the coils we have placed the + + + align:start position:0% +applied to the coils we have placed the +theoretical variation of the magnetic + + align:start position:0% +theoretical variation of the magnetic + + + align:start position:0% +theoretical variation of the magnetic +field versus position Z as a solid line + + align:start position:0% +field versus position Z as a solid line + + + align:start position:0% +field versus position Z as a solid line +directly on the oscilloscope screen + + align:start position:0% +directly on the oscilloscope screen + + + align:start position:0% +directly on the oscilloscope screen +let's see if the scope trays follows + + align:start position:0% +let's see if the scope trays follows + + + align:start position:0% +let's see if the scope trays follows +this theoretical curve we have adjusted + + align:start position:0% +this theoretical curve we have adjusted + + + align:start position:0% +this theoretical curve we have adjusted +the scope vertical gain so that the + + align:start position:0% +the scope vertical gain so that the + + + align:start position:0% +the scope vertical gain so that the +display matches the theoretical waveform + + align:start position:0% +display matches the theoretical waveform + + + align:start position:0% +display matches the theoretical waveform +at one position we'll see if the scope + + align:start position:0% +at one position we'll see if the scope + + + align:start position:0% +at one position we'll see if the scope +trays follows the shape of this + + align:start position:0% +trays follows the shape of this + + + align:start position:0% +trays follows the shape of this +theoretical curve will check the field + + align:start position:0% +theoretical curve will check the field + + + align:start position:0% +theoretical curve will check the field +magnitude later the probe is initially + + align:start position:0% +magnitude later the probe is initially + + + align:start position:0% +magnitude later the probe is initially +here we now turn on the probe carriage + + align:start position:0% +here we now turn on the probe carriage + + + align:start position:0% +here we now turn on the probe carriage +the scope horizontal gain has been + + align:start position:0% +the scope horizontal gain has been + + + align:start position:0% +the scope horizontal gain has been +adjusted so that the horizontal + + align:start position:0% +adjusted so that the horizontal + + + align:start position:0% +adjusted so that the horizontal +deflection of the scope matches the Z + + align:start position:0% +deflection of the scope matches the Z + + + align:start position:0% +deflection of the scope matches the Z +position of the probe + + align:start position:0% + + + + align:start position:0% + +the magnetic field is largest directly + + align:start position:0% +the magnetic field is largest directly + + + align:start position:0% +the magnetic field is largest directly +under a coil now the left one at Z equal + + align:start position:0% +under a coil now the left one at Z equal + + + align:start position:0% +under a coil now the left one at Z equal +minus D + + align:start position:0% + + + + align:start position:0% + +and is fairly uniform in the central + + align:start position:0% +and is fairly uniform in the central + + + align:start position:0% +and is fairly uniform in the central +region between coils with a minimum at + + align:start position:0% +region between coils with a minimum at + + + align:start position:0% +region between coils with a minimum at +the center Z equals zero + + align:start position:0% + + + + align:start position:0% + +the field increases again to a maximum + + align:start position:0% +the field increases again to a maximum + + + align:start position:0% +the field increases again to a maximum +under the right coil at Z equal D and + + align:start position:0% +under the right coil at Z equal D and + + + align:start position:0% +under the right coil at Z equal D and +decreases in the region outside the + + align:start position:0% +decreases in the region outside the + + + align:start position:0% +decreases in the region outside the +coils now the magnetic field is an odd + + align:start position:0% +coils now the magnetic field is an odd + + + align:start position:0% +coils now the magnetic field is an odd +function around Z equals zero it is zero + + align:start position:0% +function around Z equals zero it is zero + + + align:start position:0% +function around Z equals zero it is zero +in the center is expected this reversing + + align:start position:0% +in the center is expected this reversing + + + align:start position:0% +in the center is expected this reversing +switch reverses the direction of current + + align:start position:0% +switch reverses the direction of current + + + align:start position:0% +switch reverses the direction of current +in the left coil let's see how the + + align:start position:0% +in the left coil let's see how the + + + align:start position:0% +in the left coil let's see how the +measured field compares with the + + align:start position:0% +measured field compares with the + + + align:start position:0% +measured field compares with the +prediction we have aligned the zero + + align:start position:0% +prediction we have aligned the zero + + + align:start position:0% +prediction we have aligned the zero +field lines and adjusted the vertical + + align:start position:0% +field lines and adjusted the vertical + + + align:start position:0% +field lines and adjusted the vertical +gain to match the waveform at one point + + align:start position:0% +gain to match the waveform at one point + + + align:start position:0% +gain to match the waveform at one point +we now turn on the probe carriage + + align:start position:0% + + + + align:start position:0% + +the field is a negative maximum under + + align:start position:0% +the field is a negative maximum under + + + align:start position:0% +the field is a negative maximum under +the left coil + + align:start position:0% + + + + align:start position:0% + +is zero at the center + + align:start position:0% + + + + align:start position:0% + +and reaches a positive maximum under the + + align:start position:0% +and reaches a positive maximum under the + + + align:start position:0% +and reaches a positive maximum under the +right coil \ No newline at end of file diff --git a/wsOoClvZmic.txt b/wsOoClvZmic.txt new file mode 100644 index 0000000000000000000000000000000000000000..313fec30008e7a5e9faa6f6eff7b26c0a86e9bbc --- /dev/null +++ b/wsOoClvZmic.txt @@ -0,0 +1,3475 @@ +align:start position:0% + +The following content is provided under + + align:start position:0% +The following content is provided under + + + align:start position:0% +The following content is provided under +a Creative Common License. Your support + + align:start position:0% +a Creative Common License. Your support + + + align:start position:0% +a Creative Common License. Your support +will help MIT Open Courseware continue + + align:start position:0% +will help MIT Open Courseware continue + + + align:start position:0% +will help MIT Open Courseware continue +to offer high-quality educational + + align:start position:0% +to offer high-quality educational + + + align:start position:0% +to offer high-quality educational +resources for free. To make a donation + + align:start position:0% +resources for free. To make a donation + + + align:start position:0% +resources for free. To make a donation +or view additional materials from + + align:start position:0% +or view additional materials from + + + align:start position:0% +or view additional materials from +hundreds of MIT courses, visit MIT Open + + align:start position:0% +hundreds of MIT courses, visit MIT Open + + + align:start position:0% +hundreds of MIT courses, visit MIT Open +Courseware at ocw.mmit.edu. + + align:start position:0% + + + + align:start position:0% + +Hi, welcome to calculus part two where + + align:start position:0% +Hi, welcome to calculus part two where + + + align:start position:0% +Hi, welcome to calculus part two where +our theme for the entire course will + + align:start position:0% +our theme for the entire course will + + + align:start position:0% +our theme for the entire course will +essentially be functions of several + + align:start position:0% +essentially be functions of several + + + align:start position:0% +essentially be functions of several +variables but a more underlying theme a + + align:start position:0% +variables but a more underlying theme a + + + align:start position:0% +variables but a more underlying theme a +theme which will not only permeate this + + align:start position:0% +theme which will not only permeate this + + + align:start position:0% +theme which will not only permeate this +course but virtually every course in the + + align:start position:0% +course but virtually every course in the + + + align:start position:0% +course but virtually every course in the +mathematics curriculum and perhaps other + + align:start position:0% +mathematics curriculum and perhaps other + + + align:start position:0% +mathematics curriculum and perhaps other +curricular as well is the idea of what + + align:start position:0% +curricular as well is the idea of what + + + align:start position:0% +curricular as well is the idea of what +we mean by a mathematical structure. And + + align:start position:0% +we mean by a mathematical structure. And + + + align:start position:0% +we mean by a mathematical structure. And +if this sounds a little bit ominous and + + align:start position:0% +if this sounds a little bit ominous and + + + align:start position:0% +if this sounds a little bit ominous and +frightening, the idea of a mathematical + + align:start position:0% +frightening, the idea of a mathematical + + + align:start position:0% +frightening, the idea of a mathematical +structure can be compared very nicely in + + align:start position:0% +structure can be compared very nicely in + + + align:start position:0% +structure can be compared very nicely in +terms of a game. And for this reason, I + + align:start position:0% +terms of a game. And for this reason, I + + + align:start position:0% +terms of a game. And for this reason, I +have chosen to entitle our first lesson, + + align:start position:0% +have chosen to entitle our first lesson, + + + align:start position:0% +have chosen to entitle our first lesson, +the game of mathematics. The game of + + align:start position:0% +the game of mathematics. The game of + + + align:start position:0% +the game of mathematics. The game of +mathematics. And let's emphasize the + + align:start position:0% +mathematics. And let's emphasize the + + + align:start position:0% +mathematics. And let's emphasize the +word game here. We do not mean game in a + + align:start position:0% +word game here. We do not mean game in a + + + align:start position:0% +word game here. We do not mean game in a +trivial sense where in elementary school + + align:start position:0% +trivial sense where in elementary school + + + align:start position:0% +trivial sense where in elementary school +the first row races the second row to + + align:start position:0% +the first row races the second row to + + + align:start position:0% +the first row races the second row to +see who finishes the addition problem + + align:start position:0% +see who finishes the addition problem + + + align:start position:0% +see who finishes the addition problem +first. The idea that we want to talk + + align:start position:0% +first. The idea that we want to talk + + + align:start position:0% +first. The idea that we want to talk +about is what is a game? And I remember + + align:start position:0% +about is what is a game? And I remember + + + align:start position:0% +about is what is a game? And I remember +an old riddle when I was in about the + + align:start position:0% +an old riddle when I was in about the + + + align:start position:0% +an old riddle when I was in about the +fourth or fifth grade when somebody said + + align:start position:0% +fourth or fifth grade when somebody said + + + align:start position:0% +fourth or fifth grade when somebody said +to me, "What is it that looks like a + + align:start position:0% +to me, "What is it that looks like a + + + align:start position:0% +to me, "What is it that looks like a +box, smells like cheese, and flies?" And + + align:start position:0% +box, smells like cheese, and flies?" And + + + align:start position:0% +box, smells like cheese, and flies?" And +the answer was a flying cheese box. And + + align:start position:0% +the answer was a flying cheese box. And + + + align:start position:0% +the answer was a flying cheese box. And +the interesting point is that this is + + align:start position:0% +the interesting point is that this is + + + align:start position:0% +the interesting point is that this is +how in the scientific world we often + + align:start position:0% +how in the scientific world we often + + + align:start position:0% +how in the scientific world we often +make up definitions. Namely, to define a + + align:start position:0% +make up definitions. Namely, to define a + + + align:start position:0% +make up definitions. Namely, to define a +game, we try to think of every single + + align:start position:0% +game, we try to think of every single + + + align:start position:0% +game, we try to think of every single +ingredient that is common to every game. + + align:start position:0% +ingredient that is common to every game. + + + align:start position:0% +ingredient that is common to every game. +And then we roll all of these + + align:start position:0% +And then we roll all of these + + + align:start position:0% +And then we roll all of these +ingredients into one long definition and + + align:start position:0% +ingredients into one long definition and + + + align:start position:0% +ingredients into one long definition and +that becomes our final definition. And + + align:start position:0% +that becomes our final definition. And + + + align:start position:0% +that becomes our final definition. And +with that in mind, + + align:start position:0% +with that in mind, + + + align:start position:0% +with that in mind, +let me take the following TAC. And again + + align:start position:0% +let me take the following TAC. And again + + + align:start position:0% +let me take the following TAC. And again +let me point out that I am going through + + align:start position:0% +let me point out that I am going through + + + align:start position:0% +let me point out that I am going through +this rather hurriedly because the main + + align:start position:0% +this rather hurriedly because the main + + + align:start position:0% +this rather hurriedly because the main +aim of the lesson is to give an overview + + align:start position:0% +aim of the lesson is to give an overview + + + align:start position:0% +aim of the lesson is to give an overview +with the idea that the supplementary + + align:start position:0% +with the idea that the supplementary + + + align:start position:0% +with the idea that the supplementary +notes and the exercises at the in the + + align:start position:0% +notes and the exercises at the in the + + + align:start position:0% +notes and the exercises at the in the +unit will give you the computational + + align:start position:0% +unit will give you the computational + + + align:start position:0% +unit will give you the computational +drill that you need. But for a first + + align:start position:0% +drill that you need. But for a first + + + align:start position:0% +drill that you need. But for a first +approximation let us say that in any + + align:start position:0% +approximation let us say that in any + + + align:start position:0% +approximation let us say that in any +game you must have definitions so that + + align:start position:0% +game you must have definitions so that + + + align:start position:0% +game you must have definitions so that +you know what terminology you have. Then + + align:start position:0% +you know what terminology you have. Then + + + align:start position:0% +you know what terminology you have. Then +you must have rules of the game and + + align:start position:0% +you must have rules of the game and + + + align:start position:0% +you must have rules of the game and +notice that the rules of the game are + + align:start position:0% +notice that the rules of the game are + + + align:start position:0% +notice that the rules of the game are +relationships between the terms or as a + + align:start position:0% +relationships between the terms or as a + + + align:start position:0% +relationships between the terms or as a +trivial example in playing cards. There + + align:start position:0% +trivial example in playing cards. There + + + align:start position:0% +trivial example in playing cards. There +are many different card games that can + + align:start position:0% +are many different card games that can + + + align:start position:0% +are many different card games that can +be played with the same deck of cards. + + align:start position:0% +be played with the same deck of cards. + + + align:start position:0% +be played with the same deck of cards. +What makes the game different is not + + align:start position:0% +What makes the game different is not + + + align:start position:0% +What makes the game different is not +diff different are not the definitions + + align:start position:0% +diff different are not the definitions + + + align:start position:0% +diff different are not the definitions +involved but the rules of the game. And + + align:start position:0% +involved but the rules of the game. And + + + align:start position:0% +involved but the rules of the game. And +finally, there are objectives. Well, + + align:start position:0% +finally, there are objectives. Well, + + + align:start position:0% +finally, there are objectives. Well, +obviously the objective of any game is + + align:start position:0% +obviously the objective of any game is + + + align:start position:0% +obviously the objective of any game is +to win. What we really mean by an + + align:start position:0% +to win. What we really mean by an + + + align:start position:0% +to win. What we really mean by an +objective is the art of carrying out a + + align:start position:0% +objective is the art of carrying out a + + + align:start position:0% +objective is the art of carrying out a +winning situation by successfully + + align:start position:0% +winning situation by successfully + + + align:start position:0% +winning situation by successfully +employing the definitions and the rules. + + align:start position:0% +employing the definitions and the rules. + + + align:start position:0% +employing the definitions and the rules. +All right? And the way we do that is + + align:start position:0% +All right? And the way we do that is + + + align:start position:0% +All right? And the way we do that is +usually called strategy. Strategy is the + + align:start position:0% +usually called strategy. Strategy is the + + + align:start position:0% +usually called strategy. Strategy is the +art of using the definitions and rules + + align:start position:0% +art of using the definitions and rules + + + align:start position:0% +art of using the definitions and rules +to carry out the objective in an + + align:start position:0% +to carry out the objective in an + + + align:start position:0% +to carry out the objective in an +inescapable manner. And the reason I + + align:start position:0% +inescapable manner. And the reason I + + + align:start position:0% +inescapable manner. And the reason I +like this particular little setup is it + + align:start position:0% +like this particular little setup is it + + + align:start position:0% +like this particular little setup is it +gives me a way to show you in + + align:start position:0% +gives me a way to show you in + + + align:start position:0% +gives me a way to show you in +juxtaposition the role of wrote versus + + align:start position:0% +juxtaposition the role of wrote versus + + + align:start position:0% +juxtaposition the role of wrote versus +reason, logic versus memory in any + + align:start position:0% +reason, logic versus memory in any + + + align:start position:0% +reason, logic versus memory in any +mathematical situation or real life + + align:start position:0% +mathematical situation or real life + + + align:start position:0% +mathematical situation or real life +situation. Namely, the strategy part of + + align:start position:0% +situation. Namely, the strategy part of + + + align:start position:0% +situation. Namely, the strategy part of +a game is logic and things like the + + align:start position:0% +a game is logic and things like the + + + align:start position:0% +a game is logic and things like the +definitions and the rules + + align:start position:0% +definitions and the rules + + + align:start position:0% +definitions and the rules +are things that we memorize. + + align:start position:0% + + + + align:start position:0% + +Okay. Now the thing that we're going to + + align:start position:0% +Okay. Now the thing that we're going to + + + align:start position:0% +Okay. Now the thing that we're going to +do in our particular course is always + + align:start position:0% +do in our particular course is always + + + align:start position:0% +do in our particular course is always +come back to this particular structure. + + align:start position:0% +come back to this particular structure. + + + align:start position:0% +come back to this particular structure. +In other words, our definition of a game + + align:start position:0% +In other words, our definition of a game + + + align:start position:0% +In other words, our definition of a game +is any system which consists of + + align:start position:0% +is any system which consists of + + + align:start position:0% +is any system which consists of +definitions, rules and objectives where + + align:start position:0% +definitions, rules and objectives where + + + align:start position:0% +definitions, rules and objectives where +the objective is carried out as an + + align:start position:0% +the objective is carried out as an + + + align:start position:0% +the objective is carried out as an +inescapable consequence of the + + align:start position:0% +inescapable consequence of the + + + align:start position:0% +inescapable consequence of the +definitions and the rules by means of + + align:start position:0% +definitions and the rules by means of + + + align:start position:0% +definitions and the rules by means of +strategy. And by the way, don't take + + align:start position:0% +strategy. And by the way, don't take + + + align:start position:0% +strategy. And by the way, don't take +this lightly. This is a very serious + + align:start position:0% +this lightly. This is a very serious + + + align:start position:0% +this lightly. This is a very serious +topic. Later in the course, the + + align:start position:0% +topic. Later in the course, the + + + align:start position:0% +topic. Later in the course, the +computation will become sufficiently + + align:start position:0% +computation will become sufficiently + + + align:start position:0% +computation will become sufficiently +difficult that we may lose sight of the + + align:start position:0% +difficult that we may lose sight of the + + + align:start position:0% +difficult that we may lose sight of the +forest because of the trees. Right now, + + align:start position:0% +forest because of the trees. Right now, + + + align:start position:0% +forest because of the trees. Right now, +what I want to do is emphasize this to + + align:start position:0% +what I want to do is emphasize this to + + + align:start position:0% +what I want to do is emphasize this to +you in terms of topics that you're + + align:start position:0% +you in terms of topics that you're + + + align:start position:0% +you in terms of topics that you're +already familiar with so that you can + + align:start position:0% +already familiar with so that you can + + + align:start position:0% +already familiar with so that you can +see what the overall structure of + + align:start position:0% +see what the overall structure of + + + align:start position:0% +see what the overall structure of +mathematics is so that you will not be + + align:start position:0% +mathematics is so that you will not be + + + align:start position:0% +mathematics is so that you will not be +preoccupied with this when we're + + align:start position:0% +preoccupied with this when we're + + + align:start position:0% +preoccupied with this when we're +learning more computational things. Let + + align:start position:0% +learning more computational things. Let + + + align:start position:0% +learning more computational things. Let +me just take a look at well a relatively + + align:start position:0% +me just take a look at well a relatively + + + align:start position:0% +me just take a look at well a relatively +trivial example. + + align:start position:0% +trivial example. + + + align:start position:0% +trivial example. +I call this a new look at counting. We + + align:start position:0% +I call this a new look at counting. We + + + align:start position:0% +I call this a new look at counting. We +all know how to count. We start with a + + align:start position:0% +all know how to count. We start with a + + + align:start position:0% +all know how to count. We start with a +number called 1. And we have various + + align:start position:0% +number called 1. And we have various + + + align:start position:0% +number called 1. And we have various +definitions. 1 + 1 is 2. 2 + 1 is 3. 3 + + + align:start position:0% +definitions. 1 + 1 is 2. 2 + 1 is 3. 3 + + + + align:start position:0% +definitions. 1 + 1 is 2. 2 + 1 is 3. 3 + +1 is 4. 4 + 1 is 5. 5 + 1 is 6. 6 + 1 is + + align:start position:0% +1 is 4. 4 + 1 is 5. 5 + 1 is 6. 6 + 1 is + + + align:start position:0% +1 is 4. 4 + 1 is 5. 5 + 1 is 6. 6 + 1 is +7 etc. Okay. So far so good. Now we ask + + align:start position:0% +7 etc. Okay. So far so good. Now we ask + + + align:start position:0% +7 etc. Okay. So far so good. Now we ask +the question, how much is 4 + 3? Now + + align:start position:0% +the question, how much is 4 + 3? Now + + + align:start position:0% +the question, how much is 4 + 3? Now +obviously we all know that 4 + 3 is 7. + + align:start position:0% +obviously we all know that 4 + 3 is 7. + + + align:start position:0% +obviously we all know that 4 + 3 is 7. +We're not saying what are we looking at + + align:start position:0% +We're not saying what are we looking at + + + align:start position:0% +We're not saying what are we looking at +this problem for. What we're trying to + + align:start position:0% +this problem for. What we're trying to + + + align:start position:0% +this problem for. What we're trying to +show now is a very important aspect of + + align:start position:0% +show now is a very important aspect of + + + align:start position:0% +show now is a very important aspect of +the game of mathematics. You see notice + + align:start position:0% +the game of mathematics. You see notice + + + align:start position:0% +the game of mathematics. You see notice +that in our list of definitions, no + + align:start position:0% +that in our list of definitions, no + + + align:start position:0% +that in our list of definitions, no +place do we have the sum 4 + 3 defined. + + align:start position:0% +place do we have the sum 4 + 3 defined. + + + align:start position:0% +place do we have the sum 4 + 3 defined. +What we are interested in now is not so + + align:start position:0% +What we are interested in now is not so + + + align:start position:0% +What we are interested in now is not so +much the truthful statement that 4 plus + + align:start position:0% +much the truthful statement that 4 plus + + + align:start position:0% +much the truthful statement that 4 plus +3 is 7, but whether the result 4 + 3 + + align:start position:0% +3 is 7, but whether the result 4 + 3 + + + align:start position:0% +3 is 7, but whether the result 4 + 3 +equals 7 follows inescapably from the + + align:start position:0% +equals 7 follows inescapably from the + + + align:start position:0% +equals 7 follows inescapably from the +definitions that we've listed. Now you + + align:start position:0% +definitions that we've listed. Now you + + + align:start position:0% +definitions that we've listed. Now you +see the point is all we've listed are + + align:start position:0% +see the point is all we've listed are + + + align:start position:0% +see the point is all we've listed are +definitions. We haven't told any + + align:start position:0% +definitions. We haven't told any + + + align:start position:0% +definitions. We haven't told any +particular rules of the game yet. Well, + + align:start position:0% +particular rules of the game yet. Well, + + + align:start position:0% +particular rules of the game yet. Well, +let's make up some rules as we go along. + + align:start position:0% +let's make up some rules as we go along. + + + align:start position:0% +let's make up some rules as we go along. +And as I say, we'll discuss these in + + align:start position:0% +And as I say, we'll discuss these in + + + align:start position:0% +And as I say, we'll discuss these in +more details in our notes and in the + + align:start position:0% +more details in our notes and in the + + + align:start position:0% +more details in our notes and in the +exercises. We essentially do something + + align:start position:0% +exercises. We essentially do something + + + align:start position:0% +exercises. We essentially do something +like this. We write down 4 + 3. Okay. + + align:start position:0% +like this. We write down 4 + 3. Okay. + + + align:start position:0% +like this. We write down 4 + 3. Okay. +Then we say, okay, we do know how to add + + align:start position:0% +Then we say, okay, we do know how to add + + + align:start position:0% +Then we say, okay, we do know how to add +by ones. That's what our definition + + align:start position:0% +by ones. That's what our definition + + + align:start position:0% +by ones. That's what our definition +says. So we rewrite three as 2 + 1. In + + align:start position:0% +says. So we rewrite three as 2 + 1. In + + + align:start position:0% +says. So we rewrite three as 2 + 1. In +other words, we substitute 2 + 1, which + + align:start position:0% +other words, we substitute 2 + 1, which + + + align:start position:0% +other words, we substitute 2 + 1, which +is equal to 3 by definition. Then we + + align:start position:0% +is equal to 3 by definition. Then we + + + align:start position:0% +is equal to 3 by definition. Then we +say, okay, 2 + 1 is the same as 1 + 2. + + align:start position:0% +say, okay, 2 + 1 is the same as 1 + 2. + + + align:start position:0% +say, okay, 2 + 1 is the same as 1 + 2. +Now, by the way, notice the tasted + + align:start position:0% +Now, by the way, notice the tasted + + + align:start position:0% +Now, by the way, notice the tasted +assumption that we're making. We're + + align:start position:0% +assumption that we're making. We're + + + align:start position:0% +assumption that we're making. We're +assuming that the order in which you add + + align:start position:0% +assuming that the order in which you add + + + align:start position:0% +assuming that the order in which you add +two numbers makes no difference. + + align:start position:0% +two numbers makes no difference. + + + align:start position:0% +two numbers makes no difference. +Obviously, this is not a rule in every + + align:start position:0% +Obviously, this is not a rule in every + + + align:start position:0% +Obviously, this is not a rule in every +game of life. In most things in life, + + align:start position:0% +game of life. In most things in life, + + + align:start position:0% +game of life. In most things in life, +order does make a difference. Consider, + + align:start position:0% +order does make a difference. Consider, + + + align:start position:0% +order does make a difference. Consider, +for example, the statements, first I + + align:start position:0% +for example, the statements, first I + + + align:start position:0% +for example, the statements, first I +undress and then I take a shower or + + align:start position:0% +undress and then I take a shower or + + + align:start position:0% +undress and then I take a shower or +first I shower and then I undress. + + align:start position:0% +first I shower and then I undress. + + + align:start position:0% +first I shower and then I undress. +Without meaning to pass judgment as to + + align:start position:0% +Without meaning to pass judgment as to + + + align:start position:0% +Without meaning to pass judgment as to +which is proper, at least notice there + + align:start position:0% +which is proper, at least notice there + + + align:start position:0% +which is proper, at least notice there +is a difference between the two. What + + align:start position:0% +is a difference between the two. What + + + align:start position:0% +is a difference between the two. What +we're saying is that somehow or other in + + align:start position:0% +we're saying is that somehow or other in + + + align:start position:0% +we're saying is that somehow or other in +the game of arithmetic we assume that + + align:start position:0% +the game of arithmetic we assume that + + + align:start position:0% +the game of arithmetic we assume that +addition has the property that the order + + align:start position:0% +addition has the property that the order + + + align:start position:0% +addition has the property that the order +in which you add makes no difference. So + + align:start position:0% +in which you add makes no difference. So + + + align:start position:0% +in which you add makes no difference. So +we say okay let's accept that as a rule + + align:start position:0% +we say okay let's accept that as a rule + + + align:start position:0% +we say okay let's accept that as a rule +of the game. If we accept that as a rule + + align:start position:0% +of the game. If we accept that as a rule + + + align:start position:0% +of the game. If we accept that as a rule +of a game 2 + 1 can then be substituted + + align:start position:0% +of a game 2 + 1 can then be substituted + + + align:start position:0% +of a game 2 + 1 can then be substituted +for by 1 + 2. We make the additional + + align:start position:0% +for by 1 + 2. We make the additional + + + align:start position:0% +for by 1 + 2. We make the additional +assumption that when you add three + + align:start position:0% +assumption that when you add three + + + align:start position:0% +assumption that when you add three +numbers the answer does not depend on + + align:start position:0% +numbers the answer does not depend on + + + align:start position:0% +numbers the answer does not depend on +voice inflection. In other words, that 4 + + align:start position:0% +voice inflection. In other words, that 4 + + + align:start position:0% +voice inflection. In other words, that 4 ++ 1 + 2 is equal to 4 + 1 + 2. And the + + align:start position:0% ++ 1 + 2 is equal to 4 + 1 + 2. And the + + + align:start position:0% ++ 1 + 2 is equal to 4 + 1 + 2. And the +strategy behind doing that is that we + + align:start position:0% +strategy behind doing that is that we + + + align:start position:0% +strategy behind doing that is that we +know that another name for 4 + 1 is + + align:start position:0% +know that another name for 4 + 1 is + + + align:start position:0% +know that another name for 4 + 1 is +five. In other words, we now arrive at + + align:start position:0% +five. In other words, we now arrive at + + + align:start position:0% +five. In other words, we now arrive at +the fact that 4 + 3 is equal to 5 + 2. + + align:start position:0% +the fact that 4 + 3 is equal to 5 + 2. + + + align:start position:0% +the fact that 4 + 3 is equal to 5 + 2. +We now rewrite two as 1 + 1. And we now + + align:start position:0% +We now rewrite two as 1 + 1. And we now + + + align:start position:0% +We now rewrite two as 1 + 1. And we now +have that 5 + 2 is the same as 5 + 1 + + + align:start position:0% +have that 5 + 2 is the same as 5 + 1 + + + + align:start position:0% +have that 5 + 2 is the same as 5 + 1 + +1. We now again use the fact that voice + + align:start position:0% +1. We now again use the fact that voice + + + align:start position:0% +1. We now again use the fact that voice +inflection makes no difference. And we + + align:start position:0% +inflection makes no difference. And we + + + align:start position:0% +inflection makes no difference. And we +rewrite this as 5 + 1 + 1. + + align:start position:0% +rewrite this as 5 + 1 + 1. + + + align:start position:0% +rewrite this as 5 + 1 + 1. +5 + 1 we know by definition is six. And + + align:start position:0% +5 + 1 we know by definition is six. And + + + align:start position:0% +5 + 1 we know by definition is six. And +6 + 1 we know by definition is seven. In + + align:start position:0% +6 + 1 we know by definition is seven. In + + + align:start position:0% +6 + 1 we know by definition is seven. In +other words, subject to the rules that + + align:start position:0% +other words, subject to the rules that + + + align:start position:0% +other words, subject to the rules that +we've talked about implicitly here but + + align:start position:0% +we've talked about implicitly here but + + + align:start position:0% +we've talked about implicitly here but +have not stated in our game format + + align:start position:0% +have not stated in our game format + + + align:start position:0% +have not stated in our game format +explicitly. What we have shown is that + + align:start position:0% +explicitly. What we have shown is that + + + align:start position:0% +explicitly. What we have shown is that +if we accept certain rules, it follows + + align:start position:0% +if we accept certain rules, it follows + + + align:start position:0% +if we accept certain rules, it follows +from our definitions that 4 + 3= 7 is an + + align:start position:0% +from our definitions that 4 + 3= 7 is an + + + align:start position:0% +from our definitions that 4 + 3= 7 is an +inescapable conclusion. Notice that the + + align:start position:0% +inescapable conclusion. Notice that the + + + align:start position:0% +inescapable conclusion. Notice that the +inescapability of the conclusion hinges + + align:start position:0% +inescapability of the conclusion hinges + + + align:start position:0% +inescapability of the conclusion hinges +on the fact + + align:start position:0% +on the fact + + + align:start position:0% +on the fact +that we've accepted certain rules. If we + + align:start position:0% +that we've accepted certain rules. If we + + + align:start position:0% +that we've accepted certain rules. If we +change the rules, we can change the + + align:start position:0% +change the rules, we can change the + + + align:start position:0% +change the rules, we can change the +conclusions. In other words, this thing + + align:start position:0% +conclusions. In other words, this thing + + + align:start position:0% +conclusions. In other words, this thing +called drawing inescapable conclusions + + align:start position:0% +called drawing inescapable conclusions + + + align:start position:0% +called drawing inescapable conclusions +is something called validity. And + + align:start position:0% +is something called validity. And + + + align:start position:0% +is something called validity. And +validity involves the art of drawing + + align:start position:0% +validity involves the art of drawing + + + align:start position:0% +validity involves the art of drawing +inescapable conclusions using given + + align:start position:0% +inescapable conclusions using given + + + align:start position:0% +inescapable conclusions using given +rules and given definitions. We'll talk + + align:start position:0% +rules and given definitions. We'll talk + + + align:start position:0% +rules and given definitions. We'll talk +about that in more detail. But for now, + + align:start position:0% +about that in more detail. But for now, + + + align:start position:0% +about that in more detail. But for now, +notice the difference here. Before we + + align:start position:0% +notice the difference here. Before we + + + align:start position:0% +notice the difference here. Before we +did this, we knew as a conjecture, a + + align:start position:0% +did this, we knew as a conjecture, a + + + align:start position:0% +did this, we knew as a conjecture, a +past experience thing that 4 + 3= 7 is a + + align:start position:0% +past experience thing that 4 + 3= 7 is a + + + align:start position:0% +past experience thing that 4 + 3= 7 is a +true statement. What we now know is in + + align:start position:0% +true statement. What we now know is in + + + align:start position:0% +true statement. What we now know is in +terms of certain rules of the game + + align:start position:0% +terms of certain rules of the game + + + align:start position:0% +terms of certain rules of the game +coupled with the definitions that we've + + align:start position:0% +coupled with the definitions that we've + + + align:start position:0% +coupled with the definitions that we've +accepted, 4 + 3= 7 is an inescapable + + align:start position:0% +accepted, 4 + 3= 7 is an inescapable + + + align:start position:0% +accepted, 4 + 3= 7 is an inescapable +conclusion. Henceforth to be called a + + align:start position:0% +conclusion. Henceforth to be called a + + + align:start position:0% +conclusion. Henceforth to be called a +theorem in our game. Let's see if we + + align:start position:0% +theorem in our game. Let's see if we + + + align:start position:0% +theorem in our game. Let's see if we +can't get away from this rather simple + + align:start position:0% +can't get away from this rather simple + + + align:start position:0% +can't get away from this rather simple +example. And again, let me emphasize + + align:start position:0% +example. And again, let me emphasize + + + align:start position:0% +example. And again, let me emphasize +that as simple as this example is, + + align:start position:0% +that as simple as this example is, + + + align:start position:0% +that as simple as this example is, +throughout our course, we will be using + + align:start position:0% +throughout our course, we will be using + + + align:start position:0% +throughout our course, we will be using +the same technique only at a more + + align:start position:0% +the same technique only at a more + + + align:start position:0% +the same technique only at a more +sophisticated level of computational + + align:start position:0% +sophisticated level of computational + + + align:start position:0% +sophisticated level of computational +skill. But let's take a look here and + + align:start position:0% +skill. But let's take a look here and + + + align:start position:0% +skill. But let's take a look here and +see what we're really saying. + + align:start position:0% +see what we're really saying. + + + align:start position:0% +see what we're really saying. +What mathematical structure really + + align:start position:0% +What mathematical structure really + + + align:start position:0% +What mathematical structure really +involves + + align:start position:0% +involves + + + align:start position:0% +involves +is a logic machine type of thing. We + + align:start position:0% +is a logic machine type of thing. We + + + align:start position:0% +is a logic machine type of thing. We +have a logic machine. A machine that + + align:start position:0% +have a logic machine. A machine that + + + align:start position:0% +have a logic machine. A machine that +being fed any kinds of definitions, + + align:start position:0% +being fed any kinds of definitions, + + + align:start position:0% +being fed any kinds of definitions, +rules, assumptions, etc. grinds these + + align:start position:0% +rules, assumptions, etc. grinds these + + + align:start position:0% +rules, assumptions, etc. grinds these +things through and has as the out as its + + align:start position:0% +things through and has as the out as its + + + align:start position:0% +things through and has as the out as its +output inescapable conclusions. + + align:start position:0% +output inescapable conclusions. + + + align:start position:0% +output inescapable conclusions. +Okay? In other words, you feed in + + align:start position:0% +Okay? In other words, you feed in + + + align:start position:0% +Okay? In other words, you feed in +definitions, rules, etc., which by the + + align:start position:0% +definitions, rules, etc., which by the + + + align:start position:0% +definitions, rules, etc., which by the +way don't really have to be true in the + + align:start position:0% +way don't really have to be true in the + + + align:start position:0% +way don't really have to be true in the +real life sense of being true. I mean + + align:start position:0% +real life sense of being true. I mean + + + align:start position:0% +real life sense of being true. I mean +for example in the baseball game to say + + align:start position:0% +for example in the baseball game to say + + + align:start position:0% +for example in the baseball game to say +the rule is three strikes is an out + + align:start position:0% +the rule is three strikes is an out + + + align:start position:0% +the rule is three strikes is an out +there is certainly no basic truth that + + align:start position:0% +there is certainly no basic truth that + + + align:start position:0% +there is certainly no basic truth that +said that that had to be the case. What + + align:start position:0% +said that that had to be the case. What + + + align:start position:0% +said that that had to be the case. What +is true is that in the world of science + + align:start position:0% +is true is that in the world of science + + + align:start position:0% +is true is that in the world of science +the scientist is the interpreter of + + align:start position:0% +the scientist is the interpreter of + + + align:start position:0% +the scientist is the interpreter of +nature. What happens in real life + + align:start position:0% +nature. What happens in real life + + + align:start position:0% +nature. What happens in real life +happens whether the scientist predicts + + align:start position:0% +happens whether the scientist predicts + + + align:start position:0% +happens whether the scientist predicts +it or not. What he tries to do is to + + align:start position:0% +it or not. What he tries to do is to + + + align:start position:0% +it or not. What he tries to do is to +make up definitions and rules which are + + align:start position:0% +make up definitions and rules which are + + + align:start position:0% +make up definitions and rules which are +compatible with his experience. Things + + align:start position:0% +compatible with his experience. Things + + + align:start position:0% +compatible with his experience. Things +which he calls truth. He feeds those + + align:start position:0% +which he calls truth. He feeds those + + + align:start position:0% +which he calls truth. He feeds those +through his logic machine, draws + + align:start position:0% +through his logic machine, draws + + + align:start position:0% +through his logic machine, draws +inescapable conclusions, + + align:start position:0% +inescapable conclusions, + + + align:start position:0% +inescapable conclusions, +and if the conclusions follow + + align:start position:0% +and if the conclusions follow + + + align:start position:0% +and if the conclusions follow +inescapably from the definitions and the + + align:start position:0% +inescapably from the definitions and the + + + align:start position:0% +inescapably from the definitions and the +rules, we call the resulting argument + + align:start position:0% +rules, we call the resulting argument + + + align:start position:0% +rules, we call the resulting argument +valid. In other words, truth is a value + + align:start position:0% +valid. In other words, truth is a value + + + align:start position:0% +valid. In other words, truth is a value +judgment that we make about a particular + + align:start position:0% +judgment that we make about a particular + + + align:start position:0% +judgment that we make about a particular +statement. Validity is a more objective + + align:start position:0% +statement. Validity is a more objective + + + align:start position:0% +statement. Validity is a more objective +thing that we attribute to an argument. + + align:start position:0% +thing that we attribute to an argument. + + + align:start position:0% +thing that we attribute to an argument. +In other words, a statement is either + + align:start position:0% +In other words, a statement is either + + + align:start position:0% +In other words, a statement is either +true or false. An argument is either + + align:start position:0% +true or false. An argument is either + + + align:start position:0% +true or false. An argument is either +valid or invalid. Meaning that we only + + align:start position:0% +valid or invalid. Meaning that we only + + + align:start position:0% +valid or invalid. Meaning that we only +judge whether the conclusion of the + + align:start position:0% +judge whether the conclusion of the + + + align:start position:0% +judge whether the conclusion of the +argument follows inescapably from the + + align:start position:0% +argument follows inescapably from the + + + align:start position:0% +argument follows inescapably from the +given assumptions independently of + + align:start position:0% +given assumptions independently of + + + align:start position:0% +given assumptions independently of +whether those assumptions happen to be + + align:start position:0% +whether those assumptions happen to be + + + align:start position:0% +whether those assumptions happen to be +true or not. By the way, as an aside, + + align:start position:0% +true or not. By the way, as an aside, + + + align:start position:0% +true or not. By the way, as an aside, +one of the reasons that the scientist + + align:start position:0% +one of the reasons that the scientist + + + align:start position:0% +one of the reasons that the scientist +prefers to dodge issues such as what is + + align:start position:0% +prefers to dodge issues such as what is + + + align:start position:0% +prefers to dodge issues such as what is +truth and leaves that to the philosopher + + align:start position:0% +truth and leaves that to the philosopher + + + align:start position:0% +truth and leaves that to the philosopher +is that truth in many cases is a + + align:start position:0% +is that truth in many cases is a + + + align:start position:0% +is that truth in many cases is a +relative thing. It's based on the + + align:start position:0% +relative thing. It's based on the + + + align:start position:0% +relative thing. It's based on the +available knowledge. It's also based on + + align:start position:0% +available knowledge. It's also based on + + + align:start position:0% +available knowledge. It's also based on +the situation that we want to handle. In + + align:start position:0% +the situation that we want to handle. In + + + align:start position:0% +the situation that we want to handle. In +other words, what is truth? + + align:start position:0% +other words, what is truth? + + + align:start position:0% +other words, what is truth? +And my claim is that the answer depends + + align:start position:0% +And my claim is that the answer depends + + + align:start position:0% +And my claim is that the answer depends +on the situation. + + align:start position:0% +on the situation. + + + align:start position:0% +on the situation. +Well, let me give you again a trivial + + align:start position:0% +Well, let me give you again a trivial + + + align:start position:0% +Well, let me give you again a trivial +arithmetic situation. Does 1/2 + 1/3= 56 + + align:start position:0% +arithmetic situation. Does 1/2 + 1/3= 56 + + + align:start position:0% +arithmetic situation. Does 1/2 + 1/3= 56 +or does 1/2 + 1/3 equal two fifths? And + + align:start position:0% +or does 1/2 + 1/3 equal two fifths? And + + + align:start position:0% +or does 1/2 + 1/3 equal two fifths? And +again, the answer is it depends on what + + align:start position:0% +again, the answer is it depends on what + + + align:start position:0% +again, the answer is it depends on what +real life problem you're dealing with. + + align:start position:0% +real life problem you're dealing with. + + + align:start position:0% +real life problem you're dealing with. +For example, if a person is working for + + align:start position:0% +For example, if a person is working for + + + align:start position:0% +For example, if a person is working for +you by the hour and he works for you for + + align:start position:0% +you by the hour and he works for you for + + + align:start position:0% +you by the hour and he works for you for +a half hour one day and a third of an + + align:start position:0% +a half hour one day and a third of an + + + align:start position:0% +a half hour one day and a third of an +hour the next day, the total time he's + + align:start position:0% +hour the next day, the total time he's + + + align:start position:0% +hour the next day, the total time he's +worked is 56 of an hour. Why? Because + + align:start position:0% +worked is 56 of an hour. Why? Because + + + align:start position:0% +worked is 56 of an hour. Why? Because +this agrees with our real life + + align:start position:0% +this agrees with our real life + + + align:start position:0% +this agrees with our real life +experience that 30 minutes plus 20 + + align:start position:0% +experience that 30 minutes plus 20 + + + align:start position:0% +experience that 30 minutes plus 20 +minutes is 50 minutes. On the other + + align:start position:0% +minutes is 50 minutes. On the other + + + align:start position:0% +minutes is 50 minutes. On the other +hand, if a baseball player goes one for + + align:start position:0% +hand, if a baseball player goes one for + + + align:start position:0% +hand, if a baseball player goes one for +two in the first game of a double header + + align:start position:0% +two in the first game of a double header + + + align:start position:0% +two in the first game of a double header +and one for three in the second game of + + align:start position:0% +and one for three in the second game of + + + align:start position:0% +and one for three in the second game of +a double header, he has batted two hits + + align:start position:0% +a double header, he has batted two hits + + + align:start position:0% +a double header, he has batted two hits +in five times at bat. In fact, if you + + align:start position:0% +in five times at bat. In fact, if you + + + align:start position:0% +in five times at bat. In fact, if you +could convince the public that he had + + align:start position:0% +could convince the public that he had + + + align:start position:0% +could convince the public that he had +five hits and six times at bat, you + + align:start position:0% +five hits and six times at bat, you + + + align:start position:0% +five hits and six times at bat, you +could become a director of any economy + + align:start position:0% +could become a director of any economy + + + align:start position:0% +could become a director of any economy +program in the nation. I guess the point + + align:start position:0% +program in the nation. I guess the point + + + align:start position:0% +program in the nation. I guess the point +however is this in most arithmetic + + align:start position:0% +however is this in most arithmetic + + + align:start position:0% +however is this in most arithmetic +questions that we deal with we are used + + align:start position:0% +questions that we deal with we are used + + + align:start position:0% +questions that we deal with we are used +to the physical interpretation in which + + align:start position:0% +to the physical interpretation in which + + + align:start position:0% +to the physical interpretation in which +1/2 + 1/3= 56 reflects the real life + + align:start position:0% +1/2 + 1/3= 56 reflects the real life + + + align:start position:0% +1/2 + 1/3= 56 reflects the real life +situation. Whereas this example here may + + align:start position:0% +situation. Whereas this example here may + + + align:start position:0% +situation. Whereas this example here may +seem trivial namely how often are you + + align:start position:0% +seem trivial namely how often are you + + + align:start position:0% +seem trivial namely how often are you +going to be involved with batting + + align:start position:0% +going to be involved with batting + + + align:start position:0% +going to be involved with batting +averages unless you're doing sixth grade + + align:start position:0% +averages unless you're doing sixth grade + + + align:start position:0% +averages unless you're doing sixth grade +arithmetic. The point remains ironically + + align:start position:0% +arithmetic. The point remains ironically + + + align:start position:0% +arithmetic. The point remains ironically +or whatever you want to call it that + + align:start position:0% +or whatever you want to call it that + + + align:start position:0% +or whatever you want to call it that +this little batting average problem is + + align:start position:0% +this little batting average problem is + + + align:start position:0% +this little batting average problem is +not trivial. In the world of + + align:start position:0% +not trivial. In the world of + + + align:start position:0% +not trivial. In the world of +engineering, we know this example as the + + align:start position:0% +engineering, we know this example as the + + + align:start position:0% +engineering, we know this example as the +weighted average problem. In other + + align:start position:0% +weighted average problem. In other + + + align:start position:0% +weighted average problem. In other +words, you'll notice that 2 over5 as a + + align:start position:0% +words, you'll notice that 2 over5 as a + + + align:start position:0% +words, you'll notice that 2 over5 as a +fraction is more nearly equal to 1/3 + + align:start position:0% +fraction is more nearly equal to 1/3 + + + align:start position:0% +fraction is more nearly equal to 1/3 +than it is equal to 1/2. And the reason + + align:start position:0% +than it is equal to 1/2. And the reason + + + align:start position:0% +than it is equal to 1/2. And the reason +for that is that the player batted at + + align:start position:0% +for that is that the player batted at + + + align:start position:0% +for that is that the player batted at +the lower average one over three, one + + align:start position:0% +the lower average one over three, one + + + align:start position:0% +the lower average one over three, one +hit and three times at bat for more + + align:start position:0% +hit and three times at bat for more + + + align:start position:0% +hit and three times at bat for more +times at bat. In other words, the three + + align:start position:0% +times at bat. In other words, the three + + + align:start position:0% +times at bat. In other words, the three +has a heavier waiting factor than the + + align:start position:0% +has a heavier waiting factor than the + + + align:start position:0% +has a heavier waiting factor than the +two. And every time that you use a + + align:start position:0% +two. And every time that you use a + + + align:start position:0% +two. And every time that you use a +weighted average in a scientific + + align:start position:0% +weighted average in a scientific + + + align:start position:0% +weighted average in a scientific +engineering oriented investigation, this + + align:start position:0% +engineering oriented investigation, this + + + align:start position:0% +engineering oriented investigation, this +is the truth, not this. In other words, + + align:start position:0% +is the truth, not this. In other words, + + + align:start position:0% +is the truth, not this. In other words, +it is neither true nor false that 1/2 + + + align:start position:0% +it is neither true nor false that 1/2 + + + + align:start position:0% +it is neither true nor false that 1/2 + +1/3 equals 2- fifths or that 1/2 + 1/3= + + align:start position:0% +1/3 equals 2- fifths or that 1/2 + 1/3= + + + align:start position:0% +1/3 equals 2- fifths or that 1/2 + 1/3= +56. Which is true depends on the + + align:start position:0% +56. Which is true depends on the + + + align:start position:0% +56. Which is true depends on the +particular physical situation. You see a + + align:start position:0% +particular physical situation. You see a + + + align:start position:0% +particular physical situation. You see a +rather interesting point here that we + + align:start position:0% +rather interesting point here that we + + + align:start position:0% +rather interesting point here that we +sometimes allow truth to be based on + + align:start position:0% +sometimes allow truth to be based on + + + align:start position:0% +sometimes allow truth to be based on +what particular problem we're trying to + + align:start position:0% +what particular problem we're trying to + + + align:start position:0% +what particular problem we're trying to +solve. Another way that we manipulate + + align:start position:0% +solve. Another way that we manipulate + + + align:start position:0% +solve. Another way that we manipulate +truth is that we sometimes have a rule + + align:start position:0% +truth is that we sometimes have a rule + + + align:start position:0% +truth is that we sometimes have a rule +that we like to be true. In fact, I + + align:start position:0% +that we like to be true. In fact, I + + + align:start position:0% +that we like to be true. In fact, I +guess this is probably what happens with + + align:start position:0% +guess this is probably what happens with + + + align:start position:0% +guess this is probably what happens with +most political theories that one starts + + align:start position:0% +most political theories that one starts + + + align:start position:0% +most political theories that one starts +with the objectives, knows what it is + + align:start position:0% +with the objectives, knows what it is + + + align:start position:0% +with the objectives, knows what it is +that he wants to be true, and then + + align:start position:0% +that he wants to be true, and then + + + align:start position:0% +that he wants to be true, and then +invents the definitions and the rules to + + align:start position:0% +invents the definitions and the rules to + + + align:start position:0% +invents the definitions and the rules to +conform with this. In much the same way + + align:start position:0% +conform with this. In much the same way + + + align:start position:0% +conform with this. In much the same way +as around the fourth grade again, we + + align:start position:0% +as around the fourth grade again, we + + + align:start position:0% +as around the fourth grade again, we +learn such adages as look before you + + align:start position:0% +learn such adages as look before you + + + align:start position:0% +learn such adages as look before you +leap. And two minutes later, you learn + + align:start position:0% +leap. And two minutes later, you learn + + + align:start position:0% +leap. And two minutes later, you learn +he who hesitates is lost. and suddenly + + align:start position:0% +he who hesitates is lost. and suddenly + + + align:start position:0% +he who hesitates is lost. and suddenly +you come to the conclusion that you can + + align:start position:0% +you come to the conclusion that you can + + + align:start position:0% +you come to the conclusion that you can +make your assumptions validify any + + align:start position:0% +make your assumptions validify any + + + align:start position:0% +make your assumptions validify any +conclusion you want just by choosing + + align:start position:0% +conclusion you want just by choosing + + + align:start position:0% +conclusion you want just by choosing +your assumptions appropriately. Now if + + align:start position:0% +your assumptions appropriately. Now if + + + align:start position:0% +your assumptions appropriately. Now if +that sounds degrading let me show you + + align:start position:0% +that sounds degrading let me show you + + + align:start position:0% +that sounds degrading let me show you +how it's used effectively in + + align:start position:0% +how it's used effectively in + + + align:start position:0% +how it's used effectively in +mathematics. + + align:start position:0% +mathematics. + + + align:start position:0% +mathematics. +In other words, let me just say that + + align:start position:0% +In other words, let me just say that + + + align:start position:0% +In other words, let me just say that +predetermined rules may control truth. + + align:start position:0% +predetermined rules may control truth. + + + align:start position:0% +predetermined rules may control truth. +Let me give you an example. Going back + + align:start position:0% +Let me give you an example. Going back + + + align:start position:0% +Let me give you an example. Going back +to exponents, why does b to the 0 equal + + align:start position:0% +to exponents, why does b to the 0 equal + + + align:start position:0% +to exponents, why does b to the 0 equal +one? + + align:start position:0% +one? + + + align:start position:0% +one? +The answer is very simple that when we + + align:start position:0% +The answer is very simple that when we + + + align:start position:0% +The answer is very simple that when we +used positive exponents, + + align:start position:0% +used positive exponents, + + + align:start position:0% +used positive exponents, +positive whole number exponents, we + + align:start position:0% +positive whole number exponents, we + + + align:start position:0% +positive whole number exponents, we +talked about that many factors of B. And + + align:start position:0% +talked about that many factors of B. And + + + align:start position:0% +talked about that many factors of B. And +one of the interesting rules that we saw + + align:start position:0% +one of the interesting rules that we saw + + + align:start position:0% +one of the interesting rules that we saw +that was obeyed by whole number + + align:start position:0% +that was obeyed by whole number + + + align:start position:0% +that was obeyed by whole number +exponents was that if you multiplied B + + align:start position:0% +exponents was that if you multiplied B + + + align:start position:0% +exponents was that if you multiplied B +to the M power by B to the N power, you + + align:start position:0% +to the M power by B to the N power, you + + + align:start position:0% +to the M power by B to the N power, you +got as an answer B to the M + N power. + + align:start position:0% +got as an answer B to the M + N power. + + + align:start position:0% +got as an answer B to the M + N power. +Okay? B to the M plus N. Now, the + + align:start position:0% +Okay? B to the M plus N. Now, the + + + align:start position:0% +Okay? B to the M plus N. Now, the +interesting thing is + + align:start position:0% +interesting thing is + + + align:start position:0% +interesting thing is +that after a while, you never even paid + + align:start position:0% +that after a while, you never even paid + + + align:start position:0% +that after a while, you never even paid +attention to why this rule worked. What + + align:start position:0% +attention to why this rule worked. What + + + align:start position:0% +attention to why this rule worked. What +you did know was that this was a pretty + + align:start position:0% +you did know was that this was a pretty + + + align:start position:0% +you did know was that this was a pretty +darn convenient rule to use. + + align:start position:0% +darn convenient rule to use. + + + align:start position:0% +darn convenient rule to use. +Computationally, this rule simplified + + align:start position:0% +Computationally, this rule simplified + + + align:start position:0% +Computationally, this rule simplified +many particular combination uh uh + + align:start position:0% +many particular combination uh uh + + + align:start position:0% +many particular combination uh uh +computations that you were doing. In + + align:start position:0% +computations that you were doing. In + + + align:start position:0% +computations that you were doing. In +particular, then as soon as n is zero, + + align:start position:0% +particular, then as soon as n is zero, + + + align:start position:0% +particular, then as soon as n is zero, +you would still like to be able to use + + align:start position:0% +you would still like to be able to use + + + align:start position:0% +you would still like to be able to use +this rule. In other words, we want this + + align:start position:0% +this rule. In other words, we want this + + + align:start position:0% +this rule. In other words, we want this +nice rule to apply even when n equals z. + + align:start position:0% +nice rule to apply even when n equals z. + + + align:start position:0% +nice rule to apply even when n equals z. +Now, let's look at this from a + + align:start position:0% +Now, let's look at this from a + + + align:start position:0% +Now, let's look at this from a +computational point of view. If we want + + align:start position:0% +computational point of view. If we want + + + align:start position:0% +computational point of view. If we want +this rule + + align:start position:0% +this rule + + + align:start position:0% +this rule +to apply when n equals z, let's simply + + align:start position:0% +to apply when n equals z, let's simply + + + align:start position:0% +to apply when n equals z, let's simply +rewrite this exactly as it appears here + + align:start position:0% +rewrite this exactly as it appears here + + + align:start position:0% +rewrite this exactly as it appears here +with n equal to zero. All right, we then + + align:start position:0% +with n equal to zero. All right, we then + + + align:start position:0% +with n equal to zero. All right, we then +have what? We have B. We'll just repeat + + align:start position:0% +have what? We have B. We'll just repeat + + + align:start position:0% +have what? We have B. We'll just repeat +everything here. b to the M + + align:start position:0% +everything here. b to the M + + + align:start position:0% +everything here. b to the M +times B. Now we're replacing N by zero. + + align:start position:0% +times B. Now we're replacing N by zero. + + + align:start position:0% +times B. Now we're replacing N by zero. +So that's B to the 0. And that must + + align:start position:0% +So that's B to the 0. And that must + + + align:start position:0% +So that's B to the 0. And that must +equal B to the M + N. That's M + 0. + + align:start position:0% +equal B to the M + N. That's M + 0. + + + align:start position:0% +equal B to the M + N. That's M + 0. +But the interesting point is that we + + align:start position:0% +But the interesting point is that we + + + align:start position:0% +But the interesting point is that we +know how to add numbers. And for + + align:start position:0% +know how to add numbers. And for + + + align:start position:0% +know how to add numbers. And for +numbers, m + 0 is m. In other words, + + align:start position:0% +numbers, m + 0 is m. In other words, + + + align:start position:0% +numbers, m + 0 is m. In other words, +this is still b to the m. Now we look at + + align:start position:0% +this is still b to the m. Now we look at + + + align:start position:0% +this is still b to the m. Now we look at +this + + align:start position:0% +this + + + align:start position:0% +this +and what we're saying is if we want the + + align:start position:0% +and what we're saying is if we want the + + + align:start position:0% +and what we're saying is if we want the +rule b to the m * b to the n to equal b + + align:start position:0% +rule b to the m * b to the n to equal b + + + align:start position:0% +rule b to the m * b to the n to equal b +to the m + n to be true even when n is + + align:start position:0% +to the m + n to be true even when n is + + + align:start position:0% +to the m + n to be true even when n is +zero. This says that b to the 0 must be + + align:start position:0% +zero. This says that b to the 0 must be + + + align:start position:0% +zero. This says that b to the 0 must be +that number such that when we multiply + + align:start position:0% +that number such that when we multiply + + + align:start position:0% +that number such that when we multiply +it by b to the m we get b to the m. Now + + align:start position:0% +it by b to the m we get b to the m. Now + + + align:start position:0% +it by b to the m we get b to the m. Now +what number has the property that when + + align:start position:0% +what number has the property that when + + + align:start position:0% +what number has the property that when +you multiply it by b to the m you get b + + align:start position:0% +you multiply it by b to the m you get b + + + align:start position:0% +you multiply it by b to the m you get b +to the m? And if you're real quick, you + + align:start position:0% +to the m? And if you're real quick, you + + + align:start position:0% +to the m? And if you're real quick, you +say one. And if you're algebra oriented, + + align:start position:0% +say one. And if you're algebra oriented, + + + align:start position:0% +say one. And if you're algebra oriented, +you say b to the 0 is therefore equal b + + align:start position:0% +you say b to the 0 is therefore equal b + + + align:start position:0% +you say b to the 0 is therefore equal b +to the m / b to the m. And again, you + + align:start position:0% +to the m / b to the m. And again, you + + + align:start position:0% +to the m / b to the m. And again, you +say one, + + align:start position:0% +say one, + + + align:start position:0% +say one, +except of course that b must be unequal + + align:start position:0% +except of course that b must be unequal + + + align:start position:0% +except of course that b must be unequal +to zero because hopefully by this time + + align:start position:0% +to zero because hopefully by this time + + + align:start position:0% +to zero because hopefully by this time +we understand why we must never divide + + align:start position:0% +we understand why we must never divide + + + align:start position:0% +we understand why we must never divide +by zero. In other words, what we now + + align:start position:0% +by zero. In other words, what we now + + + align:start position:0% +by zero. In other words, what we now +have is the old high school rule that + + align:start position:0% +have is the old high school rule that + + + align:start position:0% +have is the old high school rule that +B to the 0 equals 1 provided B is + + align:start position:0% +B to the 0 equals 1 provided B is + + + align:start position:0% +B to the 0 equals 1 provided B is +unequal to zero. But here's the + + align:start position:0% +unequal to zero. But here's the + + + align:start position:0% +unequal to zero. But here's the +important point. If I have never defined + + align:start position:0% +important point. If I have never defined + + + align:start position:0% +important point. If I have never defined +B to the 0 and somebody says to me, make + + align:start position:0% +B to the 0 and somebody says to me, make + + + align:start position:0% +B to the 0 and somebody says to me, make +up a definition for B to the zero and I + + align:start position:0% +up a definition for B to the zero and I + + + align:start position:0% +up a definition for B to the zero and I +say okay B to the 0 is going to be 36. I + + align:start position:0% +say okay B to the 0 is going to be 36. I + + + align:start position:0% +say okay B to the 0 is going to be 36. I +have every right in the world to make up + + align:start position:0% +have every right in the world to make up + + + align:start position:0% +have every right in the world to make up +that definition. What I don't have a + + align:start position:0% +that definition. What I don't have a + + + align:start position:0% +that definition. What I don't have a +right to do is when I'm ever using an + + align:start position:0% +right to do is when I'm ever using an + + + align:start position:0% +right to do is when I'm ever using an +expression like B to the zero is to + + align:start position:0% +expression like B to the zero is to + + + align:start position:0% +expression like B to the zero is to +assume that I have the right to use this + + align:start position:0% +assume that I have the right to use this + + + align:start position:0% +assume that I have the right to use this +particular recipe. In other words, if I + + align:start position:0% +particular recipe. In other words, if I + + + align:start position:0% +particular recipe. In other words, if I +want to be able to use the nice recipe + + align:start position:0% +want to be able to use the nice recipe + + + align:start position:0% +want to be able to use the nice recipe +even when N is zero, I have no choice + + align:start position:0% +even when N is zero, I have no choice + + + align:start position:0% +even when N is zero, I have no choice +but to define B to the 0 to equal one. + + align:start position:0% +but to define B to the 0 to equal one. + + + align:start position:0% +but to define B to the 0 to equal one. +Therefore, we make up that definition + + align:start position:0% +Therefore, we make up that definition + + + align:start position:0% +Therefore, we make up that definition +because we want that recipe to apply. + + align:start position:0% +because we want that recipe to apply. + + + align:start position:0% +because we want that recipe to apply. +And that's exactly what we're going to + + align:start position:0% +And that's exactly what we're going to + + + align:start position:0% +And that's exactly what we're going to +be doing through most of this course. We + + align:start position:0% +be doing through most of this course. We + + + align:start position:0% +be doing through most of this course. We +are going to look at certain real life + + align:start position:0% +are going to look at certain real life + + + align:start position:0% +are going to look at certain real life +situations. We are going to look at + + align:start position:0% +situations. We are going to look at + + + align:start position:0% +situations. We are going to look at +certain recipes that we want to apply + + align:start position:0% +certain recipes that we want to apply + + + align:start position:0% +certain recipes that we want to apply +and we are going to make up definitions + + align:start position:0% +and we are going to make up definitions + + + align:start position:0% +and we are going to make up definitions +this way and then see how our + + align:start position:0% +this way and then see how our + + + align:start position:0% +this way and then see how our +inescapable conclusions follow from + + align:start position:0% +inescapable conclusions follow from + + + align:start position:0% +inescapable conclusions follow from +these definitions. More about that will + + align:start position:0% +these definitions. More about that will + + + align:start position:0% +these definitions. More about that will +be said in the remainder of this unit + + align:start position:0% +be said in the remainder of this unit + + + align:start position:0% +be said in the remainder of this unit +and our next lecture will pick up the + + align:start position:0% +and our next lecture will pick up the + + + align:start position:0% +and our next lecture will pick up the +game of mathematics in a different + + align:start position:0% +game of mathematics in a different + + + align:start position:0% +game of mathematics in a different +context. But until next time, goodbye. + + align:start position:0% + + + + align:start position:0% + +Funding for the publication of this + + align:start position:0% +Funding for the publication of this + + + align:start position:0% +Funding for the publication of this +video was provided by the Gabriella and + + align:start position:0% +video was provided by the Gabriella and + + + align:start position:0% +video was provided by the Gabriella and +Paul Rosenbomb Foundation. + + align:start position:0% +Paul Rosenbomb Foundation. + + + align:start position:0% +Paul Rosenbomb Foundation. +Help OCW continue to provide free and + + align:start position:0% +Help OCW continue to provide free and + + + align:start position:0% +Help OCW continue to provide free and +open access to MIT courses by making a + + align:start position:0% +open access to MIT courses by making a + + + align:start position:0% +open access to MIT courses by making a +donation at ocw.mmit.edu/donate. \ No newline at end of file diff --git a/wvLUlPCbc5s.txt b/wvLUlPCbc5s.txt new file mode 100644 index 0000000000000000000000000000000000000000..7d40550f14ca0b69f173d336ab0d832335590ec1 --- /dev/null +++ b/wvLUlPCbc5s.txt @@ -0,0 +1,12555 @@ +align:start position:0% + +Um, my name is Rob Clark. I'm from uh + + align:start position:0% +Um, my name is Rob Clark. I'm from uh + + + align:start position:0% +Um, my name is Rob Clark. I'm from uh +Michigan State University School of + + align:start position:0% +Michigan State University School of + + + align:start position:0% +Michigan State University School of +Packaging and I've been doing uh RFID + + align:start position:0% +Packaging and I've been doing uh RFID + + + align:start position:0% +Packaging and I've been doing uh RFID +research uh since 1999. Uh, we just are + + align:start position:0% +research uh since 1999. Uh, we just are + + + align:start position:0% +research uh since 1999. Uh, we just are +in the process of finalizing purchase of + + align:start position:0% +in the process of finalizing purchase of + + + align:start position:0% +in the process of finalizing purchase of +a 10,000 square foot facility to move uh + + align:start position:0% +a 10,000 square foot facility to move uh + + + align:start position:0% +a 10,000 square foot facility to move uh +a new lab uh that'll look at both active + + align:start position:0% +a new lab uh that'll look at both active + + + align:start position:0% +a new lab uh that'll look at both active +and passive. But um moving forward with + + align:start position:0% +and passive. But um moving forward with + + + align:start position:0% +and passive. But um moving forward with +this whole session now, uh a couple + + align:start position:0% +this whole session now, uh a couple + + + align:start position:0% +this whole session now, uh a couple +things that kind of bothered me about + + align:start position:0% +things that kind of bothered me about + + + align:start position:0% +things that kind of bothered me about +this. Um I keep walking in and on the + + align:start position:0% +this. Um I keep walking in and on the + + + align:start position:0% +this. Um I keep walking in and on the +bulletin boards right outside the door + + align:start position:0% +bulletin boards right outside the door + + + align:start position:0% +bulletin boards right outside the door +there is a big advertisement for urine + + align:start position:0% +there is a big advertisement for urine + + + align:start position:0% +there is a big advertisement for urine +town and I want to know who leaked + + align:start position:0% +town and I want to know who leaked + + + align:start position:0% +town and I want to know who leaked +information about this session. + + align:start position:0% +information about this session. + + + align:start position:0% +information about this session. +Yeah. + + align:start position:0% +Yeah. + + + align:start position:0% +Yeah. +Okay. Um from a packaging standpoint, + + align:start position:0% +Okay. Um from a packaging standpoint, + + + align:start position:0% +Okay. Um from a packaging standpoint, +how many people here are directly + + align:start position:0% +how many people here are directly + + + align:start position:0% +how many people here are directly +involved with packaging? + + align:start position:0% +involved with packaging? + + + align:start position:0% +involved with packaging? +Okay, a few uh you may or may not know + + align:start position:0% +Okay, a few uh you may or may not know + + + align:start position:0% +Okay, a few uh you may or may not know +Jim Goff, the name who founded the + + align:start position:0% +Jim Goff, the name who founded the + + + align:start position:0% +Jim Goff, the name who founded the +packaging discipline at Michigan State + + align:start position:0% +packaging discipline at Michigan State + + + align:start position:0% +packaging discipline at Michigan State +University, the first academic packaging + + align:start position:0% +University, the first academic packaging + + + align:start position:0% +University, the first academic packaging +uh facility in the world. Uh he just + + align:start position:0% +uh facility in the world. Uh he just + + + align:start position:0% +uh facility in the world. Uh he just +passed away last week and uh very + + align:start position:0% +passed away last week and uh very + + + align:start position:0% +passed away last week and uh very +unfortunate situation. + + align:start position:0% +unfortunate situation. + + + align:start position:0% +unfortunate situation. +Um, and for those of you that didn't + + align:start position:0% +Um, and for those of you that didn't + + + align:start position:0% +Um, and for those of you that didn't +know on the news this morning, Super + + align:start position:0% +know on the news this morning, Super + + + align:start position:0% +know on the news this morning, Super +Value just purchased Albertson's, and we + + align:start position:0% +Value just purchased Albertson's, and we + + + align:start position:0% +Value just purchased Albertson's, and we +don't know what that's going to do to + + align:start position:0% +don't know what that's going to do to + + + align:start position:0% +don't know what that's going to do to +their RFID + + align:start position:0% +their RFID + + + align:start position:0% +their RFID +uh, announcements. + + align:start position:0% +uh, announcements. + + + align:start position:0% +uh, announcements. +But, and I also want to thank the sound + + align:start position:0% +But, and I also want to thank the sound + + + align:start position:0% +But, and I also want to thank the sound +guy up there, uh, because he's been + + align:start position:0% +guy up there, uh, because he's been + + + align:start position:0% +guy up there, uh, because he's been +working his tail off for this entire + + align:start position:0% +working his tail off for this entire + + + align:start position:0% +working his tail off for this entire +conference. + + align:start position:0% +conference. + + + align:start position:0% +conference. +And the rest you'll wait for. + + align:start position:0% + + + + align:start position:0% + +Special thanks to Steve Miles and the + + align:start position:0% +Special thanks to Steve Miles and the + + + align:start position:0% +Special thanks to Steve Miles and the +MIT crew, the conference committee for + + align:start position:0% +MIT crew, the conference committee for + + + align:start position:0% +MIT crew, the conference committee for +all the work and phone calls that we had + + align:start position:0% +all the work and phone calls that we had + + + align:start position:0% +all the work and phone calls that we had +back and forth, all the speakers, and of + + align:start position:0% +back and forth, all the speakers, and of + + + align:start position:0% +back and forth, all the speakers, and of +course all the attendees because without + + align:start position:0% +course all the attendees because without + + + align:start position:0% +course all the attendees because without +the interchange of our ideas and your + + align:start position:0% +the interchange of our ideas and your + + + align:start position:0% +the interchange of our ideas and your +input, this wouldn't move very far. And + + align:start position:0% +input, this wouldn't move very far. And + + + align:start position:0% +input, this wouldn't move very far. And +we can all say that we're part of the + + align:start position:0% +we can all say that we're part of the + + + align:start position:0% +we can all say that we're part of the +soers club now due to our walk yesterday + + align:start position:0% +soers club now due to our walk yesterday + + + align:start position:0% +soers club now due to our walk yesterday +uh crossing the puddles uh on the way + + align:start position:0% +uh crossing the puddles uh on the way + + + align:start position:0% +uh crossing the puddles uh on the way +there. We're we're we're bound for life. + + align:start position:0% +there. We're we're we're bound for life. + + + align:start position:0% +there. We're we're we're bound for life. +Why study packaging? What does packaging + + align:start position:0% +Why study packaging? What does packaging + + + align:start position:0% +Why study packaging? What does packaging +have to do with uh riffid or arid or + + align:start position:0% +have to do with uh riffid or arid or + + + align:start position:0% +have to do with uh riffid or arid or +anything else? Well, Throck Morton P. + + align:start position:0% +anything else? Well, Throck Morton P. + + + align:start position:0% +anything else? Well, Throck Morton P. +Ruddy III, one of my favorite people, + + align:start position:0% +Ruddy III, one of my favorite people, + + + align:start position:0% +Ruddy III, one of my favorite people, +once stated, "Packaging is a center of + + align:start position:0% +once stated, "Packaging is a center of + + + align:start position:0% +once stated, "Packaging is a center of +the universe. You might as well accept + + align:start position:0% +the universe. You might as well accept + + + align:start position:0% +the universe. You might as well accept +it now. All these other disciplines and + + align:start position:0% +it now. All these other disciplines and + + + align:start position:0% +it now. All these other disciplines and +fields just support packaging." And once + + align:start position:0% +fields just support packaging." And once + + + align:start position:0% +fields just support packaging." And once +you come to that agreement, you'll see + + align:start position:0% +you come to that agreement, you'll see + + + align:start position:0% +you come to that agreement, you'll see +why packaging is relevant to RFID. + + align:start position:0% +why packaging is relevant to RFID. + + + align:start position:0% +why packaging is relevant to RFID. +Our work is a ground level handson + + align:start position:0% +Our work is a ground level handson + + + align:start position:0% +Our work is a ground level handson +approach. A lot of the information that + + align:start position:0% +approach. A lot of the information that + + + align:start position:0% +approach. A lot of the information that +I hear is the 30,000 foot overview which + + align:start position:0% +I hear is the 30,000 foot overview which + + + align:start position:0% +I hear is the 30,000 foot overview which +is wonderful. It sets direction. It sets + + align:start position:0% +is wonderful. It sets direction. It sets + + + align:start position:0% +is wonderful. It sets direction. It sets +precedent and it doesn't mean if it + + align:start position:0% +precedent and it doesn't mean if it + + + align:start position:0% +precedent and it doesn't mean if it +doesn't work. You have to have the + + align:start position:0% +doesn't work. You have to have the + + + align:start position:0% +doesn't work. You have to have the +ground level hands-on approach to make + + align:start position:0% +ground level hands-on approach to make + + + align:start position:0% +ground level hands-on approach to make +sure it works. That's what packaging + + align:start position:0% +sure it works. That's what packaging + + + align:start position:0% +sure it works. That's what packaging +does. + + align:start position:0% +does. + + + align:start position:0% +does. +Now, why is this so? + + align:start position:0% +Now, why is this so? + + + align:start position:0% +Now, why is this so? +What is packaging? Real quickly, you're + + align:start position:0% +What is packaging? Real quickly, you're + + + align:start position:0% +What is packaging? Real quickly, you're +all going to be experts in 30 seconds or + + align:start position:0% +all going to be experts in 30 seconds or + + + align:start position:0% +all going to be experts in 30 seconds or +so. There are different levels of + + align:start position:0% +so. There are different levels of + + + align:start position:0% +so. There are different levels of +packaging. Primary, secondary, tertiary, + + align:start position:0% +packaging. Primary, secondary, tertiary, + + + align:start position:0% +packaging. Primary, secondary, tertiary, +all the way up through unitiz loads or + + align:start position:0% +all the way up through unitiz loads or + + + align:start position:0% +all the way up through unitiz loads or +cargo container loads, however you want + + align:start position:0% +cargo container loads, however you want + + + align:start position:0% +cargo container loads, however you want +to look at it. Primary physically holds + + align:start position:0% +to look at it. Primary physically holds + + + align:start position:0% +to look at it. Primary physically holds +the product. A bottle is a primary + + align:start position:0% +the product. A bottle is a primary + + + align:start position:0% +the product. A bottle is a primary +container. Secondary container, we're + + align:start position:0% +container. Secondary container, we're + + + align:start position:0% +container. Secondary container, we're +really brilliant, holds primary + + align:start position:0% +really brilliant, holds primary + + + align:start position:0% +really brilliant, holds primary +containers. So, a six-ack of your + + align:start position:0% +containers. So, a six-ack of your + + + align:start position:0% +containers. So, a six-ack of your +favorite Amber beverages would be a + + align:start position:0% +favorite Amber beverages would be a + + + align:start position:0% +favorite Amber beverages would be a +secondary container. Tertiary, I bet + + align:start position:0% +secondary container. Tertiary, I bet + + + align:start position:0% +secondary container. Tertiary, I bet +you're getting this now, holds the + + align:start position:0% +you're getting this now, holds the + + + align:start position:0% +you're getting this now, holds the +secondary. So, a shipping case would be + + align:start position:0% +secondary. So, a shipping case would be + + + align:start position:0% +secondary. So, a shipping case would be +the tertiary and on and on and on. Not + + align:start position:0% +the tertiary and on and on and on. Not + + + align:start position:0% +the tertiary and on and on and on. Not +all products have the same levels or + + align:start position:0% +all products have the same levels or + + + align:start position:0% +all products have the same levels or +requirements. + + align:start position:0% +requirements. + + + align:start position:0% +requirements. +You also have different requirements for + + align:start position:0% +You also have different requirements for + + + align:start position:0% +You also have different requirements for +different industries. You have the + + align:start position:0% +different industries. You have the + + + align:start position:0% +different industries. You have the +consumer sector, which we've heard a + + align:start position:0% +consumer sector, which we've heard a + + + align:start position:0% +consumer sector, which we've heard a +great deal about, retail outlets, these + + align:start position:0% +great deal about, retail outlets, these + + + align:start position:0% +great deal about, retail outlets, these +types of things. Industrial sector + + align:start position:0% +types of things. Industrial sector + + + align:start position:0% +types of things. Industrial sector +really hasn't gotten a lot of play here + + align:start position:0% +really hasn't gotten a lot of play here + + + align:start position:0% +really hasn't gotten a lot of play here +except some of the the DHL and larger + + align:start position:0% +except some of the the DHL and larger + + + align:start position:0% +except some of the the DHL and larger +volumes, but it's a huge market. When + + align:start position:0% +volumes, but it's a huge market. When + + + align:start position:0% +volumes, but it's a huge market. When +you think of all the trucks you see + + align:start position:0% +you think of all the trucks you see + + + align:start position:0% +you think of all the trucks you see +driving down the highways with the big + + align:start position:0% +driving down the highways with the big + + + align:start position:0% +driving down the highways with the big +boxes of materials or machinery, that's + + align:start position:0% +boxes of materials or machinery, that's + + + align:start position:0% +boxes of materials or machinery, that's +an a sector that is completely ignored. + + align:start position:0% +an a sector that is completely ignored. + + + align:start position:0% +an a sector that is completely ignored. +military. + + align:start position:0% +military. + + + align:start position:0% +military. +Think about packaging something that you + + align:start position:0% +Think about packaging something that you + + + align:start position:0% +Think about packaging something that you +don't know when it's going to be used, + + align:start position:0% +don't know when it's going to be used, + + + align:start position:0% +don't know when it's going to be used, +where it's going to be used, or what the + + align:start position:0% +where it's going to be used, or what the + + + align:start position:0% +where it's going to be used, or what the +evaluation is for once it is in use + + align:start position:0% +evaluation is for once it is in use + + + align:start position:0% +evaluation is for once it is in use +somewhere between now and 20 years from + + align:start position:0% +somewhere between now and 20 years from + + + align:start position:0% +somewhere between now and 20 years from +now. How do you package that? Real + + align:start position:0% +now. How do you package that? Real + + + align:start position:0% +now. How do you package that? Real +interesting dichotomy. And then of + + align:start position:0% +interesting dichotomy. And then of + + + align:start position:0% +interesting dichotomy. And then of +course medical pharmaceuticals, which + + align:start position:0% +course medical pharmaceuticals, which + + + align:start position:0% +course medical pharmaceuticals, which +we've heard a great deal about. How many + + align:start position:0% +we've heard a great deal about. How many + + + align:start position:0% +we've heard a great deal about. How many +of you want your packaging to fail + + align:start position:0% +of you want your packaging to fail + + + align:start position:0% +of you want your packaging to fail +prior to taking your medicine? Okay. + + align:start position:0% +prior to taking your medicine? Okay. + + + align:start position:0% +prior to taking your medicine? Okay. +Huge implications and what goes on for + + align:start position:0% +Huge implications and what goes on for + + + align:start position:0% +Huge implications and what goes on for +uh powdered soap for uh Mr. Proctor and + + align:start position:0% +uh powdered soap for uh Mr. Proctor and + + + align:start position:0% +uh powdered soap for uh Mr. Proctor and +Gamble Cascade. You brought that up + + align:start position:0% +Gamble Cascade. You brought that up + + + align:start position:0% +Gamble Cascade. You brought that up +earlier + + align:start position:0% +earlier + + + align:start position:0% +earlier +uh is a little different than what goes + + align:start position:0% +uh is a little different than what goes + + + align:start position:0% +uh is a little different than what goes +on for a uh life-saving medicine and + + align:start position:0% +on for a uh life-saving medicine and + + + align:start position:0% +on for a uh life-saving medicine and +there are different requirements. So + + align:start position:0% +there are different requirements. So + + + align:start position:0% +there are different requirements. So +packaging has to address those. It then + + align:start position:0% +packaging has to address those. It then + + + align:start position:0% +packaging has to address those. It then +has to do all of that with an eye + + align:start position:0% +has to do all of that with an eye + + + align:start position:0% +has to do all of that with an eye +towards cost. And for 10 seconds, cost + + align:start position:0% +towards cost. And for 10 seconds, cost + + + align:start position:0% +towards cost. And for 10 seconds, cost +and price are not equal. Period. You + + align:start position:0% +and price are not equal. Period. You + + + align:start position:0% +and price are not equal. Period. You +don't talk about the the uh adversion to + + align:start position:0% +don't talk about the the uh adversion to + + + align:start position:0% +don't talk about the the uh adversion to +moving into RFID because of the cost. + + align:start position:0% +moving into RFID because of the cost. + + + align:start position:0% +moving into RFID because of the cost. +It's actually the price that most people + + align:start position:0% +It's actually the price that most people + + + align:start position:0% +It's actually the price that most people +if they look at the cost you have + + align:start position:0% +if they look at the cost you have + + + align:start position:0% +if they look at the cost you have +insurance costs, liability costs, + + align:start position:0% +insurance costs, liability costs, + + + align:start position:0% +insurance costs, liability costs, +opportunity costs, uh goodwill costs and + + align:start position:0% +opportunity costs, uh goodwill costs and + + + align:start position:0% +opportunity costs, uh goodwill costs and +you have to balance the costs positive + + align:start position:0% +you have to balance the costs positive + + + align:start position:0% +you have to balance the costs positive +and negative before you can make a + + align:start position:0% +and negative before you can make a + + + align:start position:0% +and negative before you can make a +business case and that's more the + + align:start position:0% +business case and that's more the + + + align:start position:0% +business case and that's more the +business side coming out. Price is what + + align:start position:0% +business side coming out. Price is what + + + align:start position:0% +business side coming out. Price is what +you pay for something. Environmental + + align:start position:0% +you pay for something. Environmental + + + align:start position:0% +you pay for something. Environmental +issues. + + align:start position:0% +issues. + + + align:start position:0% +issues. +Simply put, your product plus your + + align:start position:0% +Simply put, your product plus your + + + align:start position:0% +Simply put, your product plus your +package + + align:start position:0% +package + + + align:start position:0% +package +at worst has to equal the environment + + align:start position:0% +at worst has to equal the environment + + + align:start position:0% +at worst has to equal the environment +that you're going to ship it through. + + align:start position:0% +that you're going to ship it through. + + + align:start position:0% +that you're going to ship it through. +Now you know everything you need to know + + align:start position:0% +Now you know everything you need to know + + + align:start position:0% +Now you know everything you need to know +about packaging pretty much. If a + + align:start position:0% +about packaging pretty much. If a + + + align:start position:0% +about packaging pretty much. If a +package doesn't do its job in that + + align:start position:0% +package doesn't do its job in that + + + align:start position:0% +package doesn't do its job in that +environment, it breaks down, product + + align:start position:0% +environment, it breaks down, product + + + align:start position:0% +environment, it breaks down, product +spills, breaks, no good. If it's too + + align:start position:0% +spills, breaks, no good. If it's too + + + align:start position:0% +spills, breaks, no good. If it's too +good and your product all gets there in + + align:start position:0% +good and your product all gets there in + + + align:start position:0% +good and your product all gets there in +perfect shape, you're losing money. + + align:start position:0% +perfect shape, you're losing money. + + + align:start position:0% +perfect shape, you're losing money. +So, there's a a fine balance and + + align:start position:0% +So, there's a a fine balance and + + + align:start position:0% +So, there's a a fine balance and +trade-off there that you have to look + + align:start position:0% +trade-off there that you have to look + + + align:start position:0% +trade-off there that you have to look +at. + + align:start position:0% +at. + + + align:start position:0% +at. +Four main functions of packaging, any + + align:start position:0% +Four main functions of packaging, any + + + align:start position:0% +Four main functions of packaging, any +one of which can be considered a package + + align:start position:0% +one of which can be considered a package + + + align:start position:0% +one of which can be considered a package +by itself, but ideally most of the + + align:start position:0% +by itself, but ideally most of the + + + align:start position:0% +by itself, but ideally most of the +packages we're talking about have all + + align:start position:0% +packages we're talking about have all + + + align:start position:0% +packages we're talking about have all +four. Containment, physical holding. + + align:start position:0% +four. Containment, physical holding. + + + align:start position:0% +four. Containment, physical holding. +You'll see my little no sign up there. + + align:start position:0% +You'll see my little no sign up there. + + + align:start position:0% +You'll see my little no sign up there. +Why? Because the containment function of + + align:start position:0% +Why? Because the containment function of + + + align:start position:0% +Why? Because the containment function of +packaging really doesn't mean anything + + align:start position:0% +packaging really doesn't mean anything + + + align:start position:0% +packaging really doesn't mean anything +with respect to RFID implementation, + + align:start position:0% +with respect to RFID implementation, + + + align:start position:0% +with respect to RFID implementation, +convenience and utility, easy opening + + align:start position:0% +convenience and utility, easy opening + + + align:start position:0% +convenience and utility, easy opening +features, uh reclosability, + + align:start position:0% +features, uh reclosability, + + + align:start position:0% +features, uh reclosability, +secondary uses, these types of things in + + align:start position:0% +secondary uses, these types of things in + + + align:start position:0% +secondary uses, these types of things in +packages maybe, maybe not + + align:start position:0% +packages maybe, maybe not + + + align:start position:0% +packages maybe, maybe not +uh have uh an opportunity with RF. If + + align:start position:0% +uh have uh an opportunity with RF. If + + + align:start position:0% +uh have uh an opportunity with RF. If +you're looking at material sorting in a + + align:start position:0% +you're looking at material sorting in a + + + align:start position:0% +you're looking at material sorting in a +recycling center, maybe that's a + + align:start position:0% +recycling center, maybe that's a + + + align:start position:0% +recycling center, maybe that's a +possibility. Now, communication and + + align:start position:0% +possibility. Now, communication and + + + align:start position:0% +possibility. Now, communication and +protection. A package should communicate + + align:start position:0% +protection. A package should communicate + + + align:start position:0% +protection. A package should communicate +to the users how to open it, how to + + align:start position:0% +to the users how to open it, how to + + + align:start position:0% +to the users how to open it, how to +close it. Safety. Don't try ripping the + + align:start position:0% +close it. Safety. Don't try ripping the + + + align:start position:0% +close it. Safety. Don't try ripping the +damn plastic clamshells apart with your + + align:start position:0% +damn plastic clamshells apart with your + + + align:start position:0% +damn plastic clamshells apart with your +hands cuz you'll cut your fingers up. + + align:start position:0% +hands cuz you'll cut your fingers up. + + + align:start position:0% +hands cuz you'll cut your fingers up. +That's the number one hated package in + + align:start position:0% +That's the number one hated package in + + + align:start position:0% +That's the number one hated package in +the world. Doesn't matter what country + + align:start position:0% +the world. Doesn't matter what country + + + align:start position:0% +the world. Doesn't matter what country +you're from. People hate it. But + + align:start position:0% +you're from. People hate it. But + + + align:start position:0% +you're from. People hate it. But +protection is a really key one for + + align:start position:0% +protection is a really key one for + + + align:start position:0% +protection is a really key one for +almost every package system. You have to + + align:start position:0% +almost every package system. You have to + + + align:start position:0% +almost every package system. You have to +protect the contents from the + + align:start position:0% +protect the contents from the + + + align:start position:0% +protect the contents from the +environment. Be it a physical + + align:start position:0% +environment. Be it a physical + + + align:start position:0% +environment. Be it a physical +environment uh shock, vibration, + + align:start position:0% +environment uh shock, vibration, + + + align:start position:0% +environment uh shock, vibration, +compression during distribution and + + align:start position:0% +compression during distribution and + + + align:start position:0% +compression during distribution and +handling. Be it uh environmental in uh + + align:start position:0% +handling. Be it uh environmental in uh + + + align:start position:0% +handling. Be it uh environmental in uh +temperature, humidity, uh uh salt spray + + align:start position:0% +temperature, humidity, uh uh salt spray + + + align:start position:0% +temperature, humidity, uh uh salt spray +we had uh conference to these types of + + align:start position:0% +we had uh conference to these types of + + + align:start position:0% +we had uh conference to these types of +things. You also in many cases need a + + align:start position:0% +things. You also in many cases need a + + + align:start position:0% +things. You also in many cases need a +package to protect the environment from + + align:start position:0% +package to protect the environment from + + + align:start position:0% +package to protect the environment from +the product + + align:start position:0% +the product + + + align:start position:0% +the product +nuclear waste. How many of you want + + align:start position:0% +nuclear waste. How many of you want + + + align:start position:0% +nuclear waste. How many of you want +those packages to fall apart and leak + + align:start position:0% +those packages to fall apart and leak + + + align:start position:0% +those packages to fall apart and leak +say anytime within the next 20,000 + + align:start position:0% +say anytime within the next 20,000 + + + align:start position:0% +say anytime within the next 20,000 +years? + + align:start position:0% +years? + + + align:start position:0% +years? +So these are functions of packaging that + + align:start position:0% +So these are functions of packaging that + + + align:start position:0% +So these are functions of packaging that +you need to take into account. The + + align:start position:0% +you need to take into account. The + + + align:start position:0% +you need to take into account. The +impact of this, it's cool. Everything + + align:start position:0% +impact of this, it's cool. Everything + + + align:start position:0% +impact of this, it's cool. Everything +has to be packaged. It's the center of + + align:start position:0% +has to be packaged. It's the center of + + + align:start position:0% +has to be packaged. It's the center of +the universe. You can go into any field + + align:start position:0% +the universe. You can go into any field + + + align:start position:0% +the universe. You can go into any field +you want through packaging and students + + align:start position:0% +you want through packaging and students + + + align:start position:0% +you want through packaging and students +like that. All companies in industry use + + align:start position:0% +like that. All companies in industry use + + + align:start position:0% +like that. All companies in industry use +it at some level + + align:start position:0% +it at some level + + + align:start position:0% +it at some level +and it should withstand the rigors of + + align:start position:0% +and it should withstand the rigors of + + + align:start position:0% +and it should withstand the rigors of +distribution, manual and mechanical + + align:start position:0% +distribution, manual and mechanical + + + align:start position:0% +distribution, manual and mechanical +handlings, warehousing and storage, not + + align:start position:0% +handlings, warehousing and storage, not + + + align:start position:0% +handlings, warehousing and storage, not +create any problems and give the + + align:start position:0% +create any problems and give the + + + align:start position:0% +create any problems and give the +ultimate user a sense of value. What is + + align:start position:0% +ultimate user a sense of value. What is + + + align:start position:0% +ultimate user a sense of value. What is +value in this case? You ask somebody, + + align:start position:0% +value in this case? You ask somebody, + + + align:start position:0% +value in this case? You ask somebody, +"What is it that you want?" And then you + + align:start position:0% +"What is it that you want?" And then you + + + align:start position:0% +"What is it that you want?" And then you +give it to them. And if you really want + + align:start position:0% +give it to them. And if you really want + + + align:start position:0% +give it to them. And if you really want +customer satisfaction, give them + + align:start position:0% +customer satisfaction, give them + + + align:start position:0% +customer satisfaction, give them +something extra. What a bargain. What a + + align:start position:0% +something extra. What a bargain. What a + + + align:start position:0% +something extra. What a bargain. What a +value. Packaging can do this. + + align:start position:0% +value. Packaging can do this. + + + align:start position:0% +value. Packaging can do this. +Now, at the MSU School of Packaging, we + + align:start position:0% +Now, at the MSU School of Packaging, we + + + align:start position:0% +Now, at the MSU School of Packaging, we +focus on RFID applications for the + + align:start position:0% +focus on RFID applications for the + + + align:start position:0% +focus on RFID applications for the +supply chain because the item level is a + + align:start position:0% +supply chain because the item level is a + + + align:start position:0% +supply chain because the item level is a +great marketing thing, but it's a ways + + align:start position:0% +great marketing thing, but it's a ways + + + align:start position:0% +great marketing thing, but it's a ways +off. Um, supply chain has some real + + align:start position:0% +off. Um, supply chain has some real + + + align:start position:0% +off. Um, supply chain has some real +applications. You're using bulk + + align:start position:0% +applications. You're using bulk + + + align:start position:0% +applications. You're using bulk +quantities. You have fixed points that + + align:start position:0% +quantities. You have fixed points that + + + align:start position:0% +quantities. You have fixed points that +you're using, although they're nebulous + + align:start position:0% +you're using, although they're nebulous + + + align:start position:0% +you're using, although they're nebulous +depending on the company and everything + + align:start position:0% +depending on the company and everything + + + align:start position:0% +depending on the company and everything +else. And you want to ultimately define + + align:start position:0% +else. And you want to ultimately define + + + align:start position:0% +else. And you want to ultimately define +the perfect purchase order. So when a + + align:start position:0% +the perfect purchase order. So when a + + + align:start position:0% +the perfect purchase order. So when a +store or customer orders a product or a + + align:start position:0% +store or customer orders a product or a + + + align:start position:0% +store or customer orders a product or a +truckload of products, they get exactly + + align:start position:0% +truckload of products, they get exactly + + + align:start position:0% +truckload of products, they get exactly +what they want when they want it in the + + align:start position:0% +what they want when they want it in the + + + align:start position:0% +what they want when they want it in the +right count. And that's one of the + + align:start position:0% +right count. And that's one of the + + + align:start position:0% +right count. And that's one of the +things RFID can do. + + align:start position:0% +things RFID can do. + + + align:start position:0% +things RFID can do. +Um little aside, MSU School of + + align:start position:0% +Um little aside, MSU School of + + + align:start position:0% +Um little aside, MSU School of +Packaging, we have 600 undergraduates. + + align:start position:0% +Packaging, we have 600 undergraduates. + + + align:start position:0% +Packaging, we have 600 undergraduates. +We have just about a hundred master + + align:start position:0% +We have just about a hundred master + + + align:start position:0% +We have just about a hundred master +students and 20 PhDs. + + align:start position:0% +students and 20 PhDs. + + + align:start position:0% +students and 20 PhDs. +Who'd have thought packaging would be + + align:start position:0% +Who'd have thought packaging would be + + + align:start position:0% +Who'd have thought packaging would be +that big all in our own school. + + align:start position:0% +that big all in our own school. + + + align:start position:0% +that big all in our own school. +Now, we haven't spent a lot of time + + align:start position:0% +Now, we haven't spent a lot of time + + + align:start position:0% +Now, we haven't spent a lot of time +talking about active packaging a little + + align:start position:0% +talking about active packaging a little + + + align:start position:0% +talking about active packaging a little +bit yesterday, but there uh is a real + + align:start position:0% +bit yesterday, but there uh is a real + + + align:start position:0% +bit yesterday, but there uh is a real +opportunity for uh complimentary active + + align:start position:0% +opportunity for uh complimentary active + + + align:start position:0% +opportunity for uh complimentary active +and passive application. If you start + + align:start position:0% +and passive application. If you start + + + align:start position:0% +and passive application. If you start +down here with item levels going into a + + align:start position:0% +down here with item levels going into a + + + align:start position:0% +down here with item levels going into a +case, going into a pallet, ultimately + + align:start position:0% +case, going into a pallet, ultimately + + + align:start position:0% +case, going into a pallet, ultimately +going into a container, you can track + + align:start position:0% +going into a container, you can track + + + align:start position:0% +going into a container, you can track +those. And if you note, some of those + + align:start position:0% +those. And if you note, some of those + + + align:start position:0% +those. And if you note, some of those +require passive tags, meaning the tags + + align:start position:0% +require passive tags, meaning the tags + + + align:start position:0% +require passive tags, meaning the tags +don't have any internal energy source. + + align:start position:0% +don't have any internal energy source. + + + align:start position:0% +don't have any internal energy source. +They collect it from the readers at read + + align:start position:0% +They collect it from the readers at read + + + align:start position:0% +They collect it from the readers at read +points versus an active tag, which may + + align:start position:0% +points versus an active tag, which may + + + align:start position:0% +points versus an active tag, which may +go on the container. And you'll see if + + align:start position:0% +go on the container. And you'll see if + + + align:start position:0% +go on the container. And you'll see if +you look in the bottom corner, I stole + + align:start position:0% +you look in the bottom corner, I stole + + + align:start position:0% +you look in the bottom corner, I stole +this from the Department of Defense. Uh + + align:start position:0% +this from the Department of Defense. Uh + + + align:start position:0% +this from the Department of Defense. Uh +because this is how they ship things + + align:start position:0% +because this is how they ship things + + + align:start position:0% +because this is how they ship things +over to uh uh the Middle East for the uh + + align:start position:0% +over to uh uh the Middle East for the uh + + + align:start position:0% +over to uh uh the Middle East for the uh +uh Iraqi and Afghanistan or uh uh + + align:start position:0% +uh Iraqi and Afghanistan or uh uh + + + align:start position:0% +uh Iraqi and Afghanistan or uh uh +wherever the hell they are over there, + + align:start position:0% +wherever the hell they are over there, + + + align:start position:0% +wherever the hell they are over there, +Pakistan having problems. Um and I like + + align:start position:0% +Pakistan having problems. Um and I like + + + align:start position:0% +Pakistan having problems. Um and I like +it because it shows that you have + + align:start position:0% +it because it shows that you have + + + align:start position:0% +it because it shows that you have +different responsibilities at different + + align:start position:0% +different responsibilities at different + + + align:start position:0% +different responsibilities at different +parts of the supply chain. And there's a + + align:start position:0% +parts of the supply chain. And there's a + + + align:start position:0% +parts of the supply chain. And there's a +lot more to this, but I want you to + + align:start position:0% +lot more to this, but I want you to + + + align:start position:0% +lot more to this, but I want you to +realize that because here's the key. + + align:start position:0% +realize that because here's the key. + + + align:start position:0% +realize that because here's the key. +There's nothing that says some of those + + align:start position:0% +There's nothing that says some of those + + + align:start position:0% +There's nothing that says some of those +applications have to be RFID. + + align:start position:0% +applications have to be RFID. + + + align:start position:0% +applications have to be RFID. +I love RFID. I live and breathe RFID, + + align:start position:0% +I love RFID. I live and breathe RFID, + + + align:start position:0% +I love RFID. I live and breathe RFID, +but it's just a technology and there are + + align:start position:0% +but it's just a technology and there are + + + align:start position:0% +but it's just a technology and there are +a lot of different frequencies and + + align:start position:0% +a lot of different frequencies and + + + align:start position:0% +a lot of different frequencies and +applications, some of which are better + + align:start position:0% +applications, some of which are better + + + align:start position:0% +applications, some of which are better +suited by other technologies. There are + + align:start position:0% +suited by other technologies. There are + + + align:start position:0% +suited by other technologies. There are +different frequencies than 915. + + align:start position:0% +different frequencies than 915. + + + align:start position:0% +different frequencies than 915. +I think the uh opportunities presented + + align:start position:0% +I think the uh opportunities presented + + + align:start position:0% +I think the uh opportunities presented +by EPC for bringing a lot of positive + + align:start position:0% +by EPC for bringing a lot of positive + + + align:start position:0% +by EPC for bringing a lot of positive +things to the world is a strong + + align:start position:0% +things to the world is a strong + + + align:start position:0% +things to the world is a strong +well-defined + + align:start position:0% +well-defined + + + align:start position:0% +well-defined +uh uh forwardthinking + + align:start position:0% +uh uh forwardthinking + + + align:start position:0% +uh uh forwardthinking +process. But it's not the only RFID + + align:start position:0% +process. But it's not the only RFID + + + align:start position:0% +process. But it's not the only RFID +process out there. They cover 1356 915. + + align:start position:0% +process out there. They cover 1356 915. + + + align:start position:0% +process out there. They cover 1356 915. +Those are key elements, but there's a + + align:start position:0% +Those are key elements, but there's a + + + align:start position:0% +Those are key elements, but there's a +lot of other applications that don't use + + align:start position:0% +lot of other applications that don't use + + + align:start position:0% +lot of other applications that don't use +those frequencies, that don't use the + + align:start position:0% +those frequencies, that don't use the + + + align:start position:0% +those frequencies, that don't use the +same type of applications, and we have + + align:start position:0% +same type of applications, and we have + + + align:start position:0% +same type of applications, and we have +to be careful not to exclude those and + + align:start position:0% +to be careful not to exclude those and + + + align:start position:0% +to be careful not to exclude those and +focus only on certain areas. + + align:start position:0% +focus only on certain areas. + + + align:start position:0% +focus only on certain areas. +Now, why look to a university? Well, I + + align:start position:0% +Now, why look to a university? Well, I + + + align:start position:0% +Now, why look to a university? Well, I +made this one up because it looks cool. + + align:start position:0% +made this one up because it looks cool. + + + align:start position:0% +made this one up because it looks cool. +And of course, packaging's in the center + + align:start position:0% +And of course, packaging's in the center + + + align:start position:0% +And of course, packaging's in the center +of that universe, as we all know it + + align:start position:0% +of that universe, as we all know it + + + align:start position:0% +of that universe, as we all know it +should be by now. But we interact with + + align:start position:0% +should be by now. But we interact with + + + align:start position:0% +should be by now. But we interact with +users. We interact with institutional + + align:start position:0% +users. We interact with institutional + + + align:start position:0% +users. We interact with institutional +players and we interact with suppliers. + + align:start position:0% +players and we interact with suppliers. + + + align:start position:0% +players and we interact with suppliers. +We have nothing to sell except our work + + align:start position:0% +We have nothing to sell except our work + + + align:start position:0% +We have nothing to sell except our work +and our research. And if we don't do a + + align:start position:0% +and our research. And if we don't do a + + + align:start position:0% +and our research. And if we don't do a +good job, we don't sell it very well. So + + align:start position:0% +good job, we don't sell it very well. So + + + align:start position:0% +good job, we don't sell it very well. So +these are some of the areas that I would + + align:start position:0% +these are some of the areas that I would + + + align:start position:0% +these are some of the areas that I would +encourage you to look at, think about + + align:start position:0% +encourage you to look at, think about + + + align:start position:0% +encourage you to look at, think about +and if it makes sense for you to develop + + align:start position:0% +and if it makes sense for you to develop + + + align:start position:0% +and if it makes sense for you to develop +some of the work with the university, + + align:start position:0% +some of the work with the university, + + + align:start position:0% +some of the work with the university, +hey, we encourage it. + + align:start position:0% +hey, we encourage it. + + + align:start position:0% +hey, we encourage it. +Packaging materials. This is where I was + + align:start position:0% +Packaging materials. This is where I was + + + align:start position:0% +Packaging materials. This is where I was +afraid you were going to fall asleep, so + + align:start position:0% +afraid you were going to fall asleep, so + + + align:start position:0% +afraid you were going to fall asleep, so +I put in a moving picture for you. What + + align:start position:0% +I put in a moving picture for you. What + + + align:start position:0% +I put in a moving picture for you. What +are the materials, major materials of + + align:start position:0% +are the materials, major materials of + + + align:start position:0% +are the materials, major materials of +packaging? Well, in somewhat of an order + + align:start position:0% +packaging? Well, in somewhat of an order + + + align:start position:0% +packaging? Well, in somewhat of an order +here, wood, huge area. Very few people + + align:start position:0% +here, wood, huge area. Very few people + + + align:start position:0% +here, wood, huge area. Very few people +talk about it. They think wood, pallets, + + align:start position:0% +talk about it. They think wood, pallets, + + + align:start position:0% +talk about it. They think wood, pallets, +that's it. But there are so many wooden + + align:start position:0% +that's it. But there are so many wooden + + + align:start position:0% +that's it. But there are so many wooden +packages out there + + align:start position:0% +packages out there + + + align:start position:0% +packages out there +that you lose sight of them because + + align:start position:0% +that you lose sight of them because + + + align:start position:0% +that you lose sight of them because +they're a tree in the forest. paper, + + align:start position:0% +they're a tree in the forest. paper, + + + align:start position:0% +they're a tree in the forest. paper, +which is slightly different than that. + + align:start position:0% +which is slightly different than that. + + + align:start position:0% +which is slightly different than that. +Uh, and there are a lot of different + + align:start position:0% +Uh, and there are a lot of different + + + align:start position:0% +Uh, and there are a lot of different +types of paper. There is not one type of + + align:start position:0% +types of paper. There is not one type of + + + align:start position:0% +types of paper. There is not one type of +paper. So, you say it reads through + + align:start position:0% +paper. So, you say it reads through + + + align:start position:0% +paper. So, you say it reads through +paper. If you say that, you don't know + + align:start position:0% +paper. If you say that, you don't know + + + align:start position:0% +paper. If you say that, you don't know +what the hell you're talking about + + align:start position:0% +what the hell you're talking about + + + align:start position:0% +what the hell you're talking about +because papers are treated, coated, + + align:start position:0% +because papers are treated, coated, + + + align:start position:0% +because papers are treated, coated, +laminated, different processing issues + + align:start position:0% +laminated, different processing issues + + + align:start position:0% +laminated, different processing issues +that go on. And all of those can affect + + align:start position:0% +that go on. And all of those can affect + + + align:start position:0% +that go on. And all of those can affect +their characteristics and either lend + + align:start position:0% +their characteristics and either lend + + + align:start position:0% +their characteristics and either lend +themselves to benefit RFID or on the + + align:start position:0% +themselves to benefit RFID or on the + + + align:start position:0% +themselves to benefit RFID or on the +other side block it. Then we have + + align:start position:0% +other side block it. Then we have + + + align:start position:0% +other side block it. Then we have +problems. Plastics and these are things + + align:start position:0% +problems. Plastics and these are things + + + align:start position:0% +problems. Plastics and these are things +that I'll spend a little more time with. + + align:start position:0% +that I'll spend a little more time with. + + + align:start position:0% +that I'll spend a little more time with. +Name me the plastic. You can't. There's + + align:start position:0% +Name me the plastic. You can't. There's + + + align:start position:0% +Name me the plastic. You can't. There's +like a billion of them. It's the beauty + + align:start position:0% +like a billion of them. It's the beauty + + + align:start position:0% +like a billion of them. It's the beauty +of plastics. You can build in the + + align:start position:0% +of plastics. You can build in the + + + align:start position:0% +of plastics. You can build in the +requirements that you want. You add a + + align:start position:0% +requirements that you want. You add a + + + align:start position:0% +requirements that you want. You add a +little bit of this, a little bit of + + align:start position:0% +little bit of this, a little bit of + + + align:start position:0% +little bit of this, a little bit of +that, and you have a a gas barrier, a + + align:start position:0% +that, and you have a a gas barrier, a + + + align:start position:0% +that, and you have a a gas barrier, a +light barrier, a moisture barrier, all + + align:start position:0% +light barrier, a moisture barrier, all + + + align:start position:0% +light barrier, a moisture barrier, all +these things. And you can you can mix + + align:start position:0% +these things. And you can you can mix + + + align:start position:0% +these things. And you can you can mix +and match. So, you can design any + + align:start position:0% +and match. So, you can design any + + + align:start position:0% +and match. So, you can design any +plastic you want. Um, metals, + + align:start position:0% +plastic you want. Um, metals, + + + align:start position:0% +plastic you want. Um, metals, +huge opportunity. A lot of metal + + align:start position:0% +huge opportunity. A lot of metal + + + align:start position:0% +huge opportunity. A lot of metal +packaging still available. Um, and glass + + align:start position:0% +packaging still available. Um, and glass + + + align:start position:0% +packaging still available. Um, and glass +of course. Um, now the interesting thing + + align:start position:0% +of course. Um, now the interesting thing + + + align:start position:0% +of course. Um, now the interesting thing +about glass, well, I'll skip that. Now, + + align:start position:0% +about glass, well, I'll skip that. Now, + + + align:start position:0% +about glass, well, I'll skip that. Now, +from a packaging standpoint, + + align:start position:0% +from a packaging standpoint, + + + align:start position:0% +from a packaging standpoint, +there is no cardboard. All right. And + + align:start position:0% +there is no cardboard. All right. And + + + align:start position:0% +there is no cardboard. All right. And +I've heard several people make reference + + align:start position:0% +I've heard several people make reference + + + align:start position:0% +I've heard several people make reference +and it's okay because you hadn't had + + align:start position:0% +and it's okay because you hadn't had + + + align:start position:0% +and it's okay because you hadn't had +this class before. All right. But + + align:start position:0% +this class before. All right. But + + + align:start position:0% +this class before. All right. But +cardboard is not a technical term. And + + align:start position:0% +cardboard is not a technical term. And + + + align:start position:0% +cardboard is not a technical term. And +if you'll notice in some of the + + align:start position:0% +if you'll notice in some of the + + + align:start position:0% +if you'll notice in some of the +presentations, cardboard in one + + align:start position:0% +presentations, cardboard in one + + + align:start position:0% +presentations, cardboard in one +presentation referred to rolled paper. + + align:start position:0% +presentation referred to rolled paper. + + + align:start position:0% +presentation referred to rolled paper. +Cardboard in another referred to + + align:start position:0% +Cardboard in another referred to + + + align:start position:0% +Cardboard in another referred to +corrugated. And in another refer + + align:start position:0% +corrugated. And in another refer + + + align:start position:0% +corrugated. And in another refer +referred to paper board, which is like + + align:start position:0% +referred to paper board, which is like + + + align:start position:0% +referred to paper board, which is like +what's on the back of your uh uh writing + + align:start position:0% +what's on the back of your uh uh writing + + + align:start position:0% +what's on the back of your uh uh writing +tablets. And so from that standpoint, + + align:start position:0% +tablets. And so from that standpoint, + + + align:start position:0% +tablets. And so from that standpoint, +there are different terms. Solid fiber + + align:start position:0% +there are different terms. Solid fiber + + + align:start position:0% +there are different terms. Solid fiber +board would be the your your cardboard, + + align:start position:0% +board would be the your your cardboard, + + + align:start position:0% +board would be the your your cardboard, +if you'll use that on the back of your + + align:start position:0% +if you'll use that on the back of your + + + align:start position:0% +if you'll use that on the back of your +writing. Corrugated board, your + + align:start position:0% +writing. Corrugated board, your + + + align:start position:0% +writing. Corrugated board, your +cardboard box. And I'm going to put this + + align:start position:0% +cardboard box. And I'm going to put this + + + align:start position:0% +cardboard box. And I'm going to put this +up, not because you're idiots, but I + + align:start position:0% +up, not because you're idiots, but I + + + align:start position:0% +up, not because you're idiots, but I +just like to draw on the board. + + align:start position:0% +just like to draw on the board. + + + align:start position:0% +just like to draw on the board. +Okay, + + align:start position:0% +Okay, + + + align:start position:0% +Okay, +that's a cross-section of a corrugated + + align:start position:0% +that's a cross-section of a corrugated + + + align:start position:0% +that's a cross-section of a corrugated +box. And I have it there for a reason + + align:start position:0% +box. And I have it there for a reason + + + align:start position:0% +box. And I have it there for a reason +that I'll get to in a little bit. + + align:start position:0% +that I'll get to in a little bit. + + + align:start position:0% +that I'll get to in a little bit. +Now the impact of these materials on + + align:start position:0% +Now the impact of these materials on + + + align:start position:0% +Now the impact of these materials on +RFID + + align:start position:0% +RFID + + + align:start position:0% +RFID +different frequencies exhibit different + + align:start position:0% +different frequencies exhibit different + + + align:start position:0% +different frequencies exhibit different +behaviors around different materials in + + align:start position:0% +behaviors around different materials in + + + align:start position:0% +behaviors around different materials in +applications. + + align:start position:0% +applications. + + + align:start position:0% +applications. +Period. That's the nature of the world. + + align:start position:0% +Period. That's the nature of the world. + + + align:start position:0% +Period. That's the nature of the world. +Can't change it. You need to find the + + align:start position:0% +Can't change it. You need to find the + + + align:start position:0% +Can't change it. You need to find the +one that works. Metal has a large effect + + align:start position:0% +one that works. Metal has a large effect + + + align:start position:0% +one that works. Metal has a large effect +on most RF systems + + align:start position:0% +on most RF systems + + + align:start position:0% +on most RF systems +and particularly true at the UHF. + + align:start position:0% +and particularly true at the UHF. + + + align:start position:0% +and particularly true at the UHF. +it blocks it. It It reraiates it. It It + + align:start position:0% +it blocks it. It It reraiates it. It It + + + align:start position:0% +it blocks it. It It reraiates it. It It +uh sends it off elsewhere. Now, + + align:start position:0% +uh sends it off elsewhere. Now, + + + align:start position:0% +uh sends it off elsewhere. Now, +interestingly, if you know that, you can + + align:start position:0% +interestingly, if you know that, you can + + + align:start position:0% +interestingly, if you know that, you can +use that to your benefit. And in our + + align:start position:0% +use that to your benefit. And in our + + + align:start position:0% +use that to your benefit. And in our +facility, we've been able to double our + + align:start position:0% +facility, we've been able to double our + + + align:start position:0% +facility, we've been able to double our +read range by directing things at a an + + align:start position:0% +read range by directing things at a an + + + align:start position:0% +read range by directing things at a an +angle off of large metal structures. And + + align:start position:0% +angle off of large metal structures. And + + + align:start position:0% +angle off of large metal structures. And +it works wonderfully if you can control + + align:start position:0% +it works wonderfully if you can control + + + align:start position:0% +it works wonderfully if you can control +the environment. Now, in the supply + + align:start position:0% +the environment. Now, in the supply + + + align:start position:0% +the environment. Now, in the supply +chain, good luck. But in certain + + align:start position:0% +chain, good luck. But in certain + + + align:start position:0% +chain, good luck. But in certain +situations, you can do that. + + align:start position:0% +situations, you can do that. + + + align:start position:0% +situations, you can do that. +plastics. Now, plastics because there + + align:start position:0% +plastics. Now, plastics because there + + + align:start position:0% +plastics. Now, plastics because there +are so many different ones, they vary + + align:start position:0% +are so many different ones, they vary + + + align:start position:0% +are so many different ones, they vary +all over the map. Some plastics are RF + + align:start position:0% +all over the map. Some plastics are RF + + + align:start position:0% +all over the map. Some plastics are RF +friendly, some hate it. Common ones, + + align:start position:0% +friendly, some hate it. Common ones, + + + align:start position:0% +friendly, some hate it. Common ones, +your PETs, your polyethylene teralates, + + align:start position:0% +your PETs, your polyethylene teralates, + + + align:start position:0% +your PETs, your polyethylene teralates, +your coke bottles, um your + + align:start position:0% +your coke bottles, um your + + + align:start position:0% +your coke bottles, um your +polyethylines, your polyropylines, + + align:start position:0% +polyethylines, your polyropylines, + + + align:start position:0% +polyethylines, your polyropylines, +all of those are pretty RF friendly and + + align:start position:0% +all of those are pretty RF friendly and + + + align:start position:0% +all of those are pretty RF friendly and +can be utilized. But not all plastics + + align:start position:0% +can be utilized. But not all plastics + + + align:start position:0% +can be utilized. But not all plastics +react the same. Now, interestingly, + + align:start position:0% +react the same. Now, interestingly, + + + align:start position:0% +react the same. Now, interestingly, +glass can be claimed to have little to + + align:start position:0% +glass can be claimed to have little to + + + align:start position:0% +glass can be claimed to have little to +no effect on RF. That can be true, but + + align:start position:0% +no effect on RF. That can be true, but + + + align:start position:0% +no effect on RF. That can be true, but +you keep in mind that glass is not + + align:start position:0% +you keep in mind that glass is not + + + align:start position:0% +you keep in mind that glass is not +glass. + + align:start position:0% +glass. + + + align:start position:0% +glass. +All right, this is metaphysical already. + + align:start position:0% +All right, this is metaphysical already. + + + align:start position:0% +All right, this is metaphysical already. +All right, glass is like plastics. It's + + align:start position:0% +All right, glass is like plastics. It's + + + align:start position:0% +All right, glass is like plastics. It's +like paper. You order the type of glass + + align:start position:0% +like paper. You order the type of glass + + + align:start position:0% +like paper. You order the type of glass +you want to use. There are different + + align:start position:0% +you want to use. There are different + + + align:start position:0% +you want to use. There are different +classes of glass. Those of you in the + + align:start position:0% +classes of glass. Those of you in the + + + align:start position:0% +classes of glass. Those of you in the +pharmaceutical industry know that you + + align:start position:0% +pharmaceutical industry know that you + + + align:start position:0% +pharmaceutical industry know that you +can have class one, class 2, class 3, + + align:start position:0% +can have class one, class 2, class 3, + + + align:start position:0% +can have class one, class 2, class 3, +class 4. And in changing that, when + + align:start position:0% +class 4. And in changing that, when + + + align:start position:0% +class 4. And in changing that, when +you're making your glass, you add a + + align:start position:0% +you're making your glass, you add a + + + align:start position:0% +you're making your glass, you add a +little bit of this, a little bit of that + + align:start position:0% +little bit of this, a little bit of that + + + align:start position:0% +little bit of this, a little bit of that +to get different properties. Think about + + align:start position:0% +to get different properties. Think about + + + align:start position:0% +to get different properties. Think about +in your kitchen, those of you that have + + align:start position:0% +in your kitchen, those of you that have + + + align:start position:0% +in your kitchen, those of you that have +Pyrex cookware, if you drop it, it + + align:start position:0% +Pyrex cookware, if you drop it, it + + + align:start position:0% +Pyrex cookware, if you drop it, it +bounces. Okay? That's not the same as + + align:start position:0% +bounces. Okay? That's not the same as + + + align:start position:0% +bounces. Okay? That's not the same as +your light bulb. Glass is not always + + align:start position:0% +your light bulb. Glass is not always + + + align:start position:0% +your light bulb. Glass is not always +glass. and the composition of glass can + + align:start position:0% +glass. and the composition of glass can + + + align:start position:0% +glass. and the composition of glass can +impact the properties. Now, I didn't + + align:start position:0% +impact the properties. Now, I didn't + + + align:start position:0% +impact the properties. Now, I didn't +have time to put in a slide of this, but + + align:start position:0% +have time to put in a slide of this, but + + + align:start position:0% +have time to put in a slide of this, but +here's some testing we did. We took + + align:start position:0% +here's some testing we did. We took + + + align:start position:0% +here's some testing we did. We took +panes of glass, and it was class two, if + + align:start position:0% +panes of glass, and it was class two, if + + + align:start position:0% +panes of glass, and it was class two, if +anybody cares, like your window pane, + + align:start position:0% +anybody cares, like your window pane, + + + align:start position:0% +anybody cares, like your window pane, +clear, amber, and uh green. + + align:start position:0% +clear, amber, and uh green. + + + align:start position:0% +clear, amber, and uh green. +We took an RF tag read, got our read + + align:start position:0% +We took an RF tag read, got our read + + + align:start position:0% +We took an RF tag read, got our read +range, and then we put the tag behind + + align:start position:0% +range, and then we put the tag behind + + + align:start position:0% +range, and then we put the tag behind +glass. + + align:start position:0% +glass. + + + align:start position:0% +glass. +Our read range dropped. We sandwich the + + align:start position:0% +Our read range dropped. We sandwich the + + + align:start position:0% +Our read range dropped. We sandwich the +tag between glass. Our read range + + align:start position:0% +tag between glass. Our read range + + + align:start position:0% +tag between glass. Our read range +dropped. + + align:start position:0% +dropped. + + + align:start position:0% +dropped. +Huh? Shouldn't happen that way. But it + + align:start position:0% +Huh? Shouldn't happen that way. But it + + + align:start position:0% +Huh? Shouldn't happen that way. But it +depends on what's added. You need to + + align:start position:0% +depends on what's added. You need to + + + align:start position:0% +depends on what's added. You need to +think about that. Paper, little or no + + align:start position:0% +think about that. Paper, little or no + + + align:start position:0% +think about that. Paper, little or no +effect. And for the reasons I stated + + align:start position:0% +effect. And for the reasons I stated + + + align:start position:0% +effect. And for the reasons I stated +earlier, that's not always the case. + + align:start position:0% +earlier, that's not always the case. + + + align:start position:0% +earlier, that's not always the case. +Paper has some real unique properties, + + align:start position:0% +Paper has some real unique properties, + + + align:start position:0% +Paper has some real unique properties, +even if it's just plain brown paper like + + align:start position:0% +even if it's just plain brown paper like + + + align:start position:0% +even if it's just plain brown paper like +you get in grocery bags. Uh, we're going + + align:start position:0% +you get in grocery bags. Uh, we're going + + + align:start position:0% +you get in grocery bags. Uh, we're going +to look at that. composits. They're all + + align:start position:0% +to look at that. composits. They're all + + + align:start position:0% +to look at that. composits. They're all +over the map. Uh the only real composite + + align:start position:0% +over the map. Uh the only real composite + + + align:start position:0% +over the map. Uh the only real composite +I saw here was the bubble pack with + + align:start position:0% +I saw here was the bubble pack with + + + align:start position:0% +I saw here was the bubble pack with +myar. So it was a foilized plastic. And + + align:start position:0% +myar. So it was a foilized plastic. And + + + align:start position:0% +myar. So it was a foilized plastic. And +I'll tell you right now, that one + + align:start position:0% +I'll tell you right now, that one + + + align:start position:0% +I'll tell you right now, that one +doesn't read. It's a good insulator for + + align:start position:0% +doesn't read. It's a good insulator for + + + align:start position:0% +doesn't read. It's a good insulator for +RF energy. + + align:start position:0% +RF energy. + + + align:start position:0% +RF energy. +Problematic matchings come up because + + align:start position:0% +Problematic matchings come up because + + + align:start position:0% +Problematic matchings come up because +sometimes you have packaging and + + align:start position:0% +sometimes you have packaging and + + + align:start position:0% +sometimes you have packaging and +waterbased products. Water is + + align:start position:0% +waterbased products. Water is + + + align:start position:0% +waterbased products. Water is +particularly problematic with UHF. + + align:start position:0% +particularly problematic with UHF. + + + align:start position:0% +particularly problematic with UHF. +If you move to a different frequency, + + align:start position:0% +If you move to a different frequency, + + + align:start position:0% +If you move to a different frequency, +the water issue can decrease. All right? + + align:start position:0% +the water issue can decrease. All right? + + + align:start position:0% +the water issue can decrease. All right? +So that it becomes more friendly. + + align:start position:0% +So that it becomes more friendly. + + + align:start position:0% +So that it becomes more friendly. +They use energy through the earth to + + align:start position:0% +They use energy through the earth to + + + align:start position:0% +They use energy through the earth to +communicate with submarines. We got a + + align:start position:0% +communicate with submarines. We got a + + + align:start position:0% +communicate with submarines. We got a +500 mile long antenna buried in the + + align:start position:0% +500 mile long antenna buried in the + + + align:start position:0% +500 mile long antenna buried in the +upper peninsula of Michigan so that they + + align:start position:0% +upper peninsula of Michigan so that they + + + align:start position:0% +upper peninsula of Michigan so that they +can use frequencies through water to + + align:start position:0% +can use frequencies through water to + + + align:start position:0% +can use frequencies through water to +communicate with submarines. can use it, + + align:start position:0% +communicate with submarines. can use it, + + + align:start position:0% +communicate with submarines. can use it, +but it has to be really low in that + + align:start position:0% +but it has to be really low in that + + + align:start position:0% +but it has to be really low in that +particular case. The lower you go, the + + align:start position:0% +particular case. The lower you go, the + + + align:start position:0% +particular case. The lower you go, the +better it works. But not all liquids are + + align:start position:0% +better it works. But not all liquids are + + + align:start position:0% +better it works. But not all liquids are +water. + + align:start position:0% +water. + + + align:start position:0% +water. +If you think about it, how many of you + + align:start position:0% +If you think about it, how many of you + + + align:start position:0% +If you think about it, how many of you +put water in your car? + + align:start position:0% +put water in your car? + + + align:start position:0% +put water in your car? +I hope it goes, you know, into your + + align:start position:0% +I hope it goes, you know, into your + + + align:start position:0% +I hope it goes, you know, into your +washers rather than your fuel tank + + align:start position:0% +washers rather than your fuel tank + + + align:start position:0% +washers rather than your fuel tank +because they're different. Gasoline + + align:start position:0% +because they're different. Gasoline + + + align:start position:0% +because they're different. Gasoline +doesn't have water in it. Your gas + + align:start position:0% +doesn't have water in it. Your gas + + + align:start position:0% +doesn't have water in it. Your gas +engine doesn't like it. Um, motor oil + + align:start position:0% +engine doesn't like it. Um, motor oil + + + align:start position:0% +engine doesn't like it. Um, motor oil +does not have water in it. And so if you + + align:start position:0% +does not have water in it. And so if you + + + align:start position:0% +does not have water in it. And so if you +take those liquids, RF can go through + + align:start position:0% +take those liquids, RF can go through + + + align:start position:0% +take those liquids, RF can go through +those. + + align:start position:0% +those. + + + align:start position:0% +those. +So water-based problems is any product + + align:start position:0% +So water-based problems is any product + + + align:start position:0% +So water-based problems is any product +put in metal packaging. So your product + + align:start position:0% +put in metal packaging. So your product + + + align:start position:0% +put in metal packaging. So your product +can be perfectly red and if it goes into + + align:start position:0% +can be perfectly red and if it goes into + + + align:start position:0% +can be perfectly red and if it goes into +a package that doesn't work, you have + + align:start position:0% +a package that doesn't work, you have + + + align:start position:0% +a package that doesn't work, you have +problems. Now the uh the Cascade + + align:start position:0% +problems. Now the uh the Cascade + + + align:start position:0% +problems. Now the uh the Cascade +powdered soap that I'd mentioned earlier + + align:start position:0% +powdered soap that I'd mentioned earlier + + + align:start position:0% +powdered soap that I'd mentioned earlier +is a good example of a dry granular + + align:start position:0% +is a good example of a dry granular + + + align:start position:0% +is a good example of a dry granular +product. All right, let's put it in a + + align:start position:0% +product. All right, let's put it in a + + + align:start position:0% +product. All right, let's put it in a +standard corrugated box. Will it read or + + align:start position:0% +standard corrugated box. Will it read or + + + align:start position:0% +standard corrugated box. Will it read or +not read? What do you think? Read. + + align:start position:0% +not read? What do you think? Read. + + + align:start position:0% +not read? What do you think? Read. +Not read. + + align:start position:0% +Not read. + + + align:start position:0% +Not read. +Doesn't read. Why? It's not the water. + + align:start position:0% +Doesn't read. Why? It's not the water. + + + align:start position:0% +Doesn't read. Why? It's not the water. +One of the things you don't think about + + align:start position:0% +One of the things you don't think about + + + align:start position:0% +One of the things you don't think about +heavy iron content in the soap and hence + + align:start position:0% +heavy iron content in the soap and hence + + + align:start position:0% +heavy iron content in the soap and hence +it scatters the RF all over the place. + + align:start position:0% +it scatters the RF all over the place. + + + align:start position:0% +it scatters the RF all over the place. +So, you can't generally read through a + + align:start position:0% +So, you can't generally read through a + + + align:start position:0% +So, you can't generally read through a +uh a powdered soap. Who to think? Just + + align:start position:0% +uh a powdered soap. Who to think? Just + + + align:start position:0% +uh a powdered soap. Who to think? Just +looking up here. We have meats. We've + + align:start position:0% +looking up here. We have meats. We've + + + align:start position:0% +looking up here. We have meats. We've +been testing meats. + + align:start position:0% +been testing meats. + + + align:start position:0% +been testing meats. +Silly thing. Water-based. I talked about + + align:start position:0% +Silly thing. Water-based. I talked about + + + align:start position:0% +Silly thing. Water-based. I talked about +this is a uh TI. That's a 13.56 tag. We + + align:start position:0% +this is a uh TI. That's a 13.56 tag. We + + + align:start position:0% +this is a uh TI. That's a 13.56 tag. We +also tested it with 915 single cut of + + align:start position:0% +also tested it with 915 single cut of + + + align:start position:0% +also tested it with 915 single cut of +beef. And by the way, it was steak and + + align:start position:0% +beef. And by the way, it was steak and + + + align:start position:0% +beef. And by the way, it was steak and +damn good when we were done testing. Um + + align:start position:0% +damn good when we were done testing. Um + + + align:start position:0% +damn good when we were done testing. Um +we ran them at chilled temperatures and + + align:start position:0% +we ran them at chilled temperatures and + + + align:start position:0% +we ran them at chilled temperatures and +we ran them at frozen temperatures. 1356 + + align:start position:0% +we ran them at frozen temperatures. 1356 + + + align:start position:0% +we ran them at frozen temperatures. 1356 +you could read two or three stacked in a + + align:start position:0% +you could read two or three stacked in a + + + align:start position:0% +you could read two or three stacked in a +in a column and still be able to read + + align:start position:0% +in a column and still be able to read + + + align:start position:0% +in a column and still be able to read +through uh UHF. You could read the top + + align:start position:0% +through uh UHF. You could read the top + + + align:start position:0% +through uh UHF. You could read the top +one and that was it. wouldn't penetrate + + align:start position:0% +one and that was it. wouldn't penetrate + + + align:start position:0% +one and that was it. wouldn't penetrate +to the bottom. When we froze those same + + align:start position:0% +to the bottom. When we froze those same + + + align:start position:0% +to the bottom. When we froze those same +cuts of meats with the same tags, we + + align:start position:0% +cuts of meats with the same tags, we + + + align:start position:0% +cuts of meats with the same tags, we +could read five and six deep + + align:start position:0% +could read five and six deep + + + align:start position:0% +could read five and six deep +because the uh water molecules get bound + + align:start position:0% +because the uh water molecules get bound + + + align:start position:0% +because the uh water molecules get bound +up as ice crystals and they leave gaps + + align:start position:0% +up as ice crystals and they leave gaps + + + align:start position:0% +up as ice crystals and they leave gaps +for RF to go through. So you can read + + align:start position:0% +for RF to go through. So you can read + + + align:start position:0% +for RF to go through. So you can read +frozen a lot of times with water. And + + align:start position:0% +frozen a lot of times with water. And + + + align:start position:0% +frozen a lot of times with water. And +for those of you that care, it's + + align:start position:0% +for those of you that care, it's + + + align:start position:0% +for those of you that care, it's +dialectric constant. If you look at + + align:start position:0% +dialectric constant. If you look at + + + align:start position:0% +dialectric constant. If you look at +dialectric constant of water, it's 70 to + + align:start position:0% +dialectric constant of water, it's 70 to + + + align:start position:0% +dialectric constant of water, it's 70 to +80 depending on the properties involved. + + align:start position:0% +80 depending on the properties involved. + + + align:start position:0% +80 depending on the properties involved. +If you look at the dialectric constant + + align:start position:0% +If you look at the dialectric constant + + + align:start position:0% +If you look at the dialectric constant +of ice 3.5 + + align:start position:0% +of ice 3.5 + + + align:start position:0% +of ice 3.5 +right through it. So pretty good stuff. + + align:start position:0% +right through it. So pretty good stuff. + + + align:start position:0% +right through it. So pretty good stuff. +Um + + align:start position:0% +Um + + + align:start position:0% +Um +some of the research I just want to + + align:start position:0% +some of the research I just want to + + + align:start position:0% +some of the research I just want to +touch on these real briefly. + + align:start position:0% +touch on these real briefly. + + + align:start position:0% +touch on these real briefly. +Somebody give me a five minute sign when + + align:start position:0% +Somebody give me a five minute sign when + + + align:start position:0% +Somebody give me a five minute sign when +it's five minutes. + + align:start position:0% +it's five minutes. + + + align:start position:0% +it's five minutes. +Uh warehouse environment. This was + + align:start position:0% +Uh warehouse environment. This was + + + align:start position:0% +Uh warehouse environment. This was +starting way back when when we first + + align:start position:0% +starting way back when when we first + + + align:start position:0% +starting way back when when we first +where in the heck do you use this stuff? + + align:start position:0% +where in the heck do you use this stuff? + + + align:start position:0% +where in the heck do you use this stuff? +And so back in 99 we started this + + align:start position:0% +And so back in 99 we started this + + + align:start position:0% +And so back in 99 we started this +research. Well let's see if we can use + + align:start position:0% +research. Well let's see if we can use + + + align:start position:0% +research. Well let's see if we can use +it in a warehouse and developing a model + + align:start position:0% +it in a warehouse and developing a model + + + align:start position:0% +it in a warehouse and developing a model +for it. um transponder effects on bloom + + align:start position:0% +for it. um transponder effects on bloom + + + align:start position:0% +for it. um transponder effects on bloom +time. That meat study, the first one we + + align:start position:0% +time. That meat study, the first one we + + + align:start position:0% +time. That meat study, the first one we +looked at, because the uh inlay was + + align:start position:0% +looked at, because the uh inlay was + + + align:start position:0% +looked at, because the uh inlay was +printed on PET, if you put that on the + + align:start position:0% +printed on PET, if you put that on the + + + align:start position:0% +printed on PET, if you put that on the +surface over the meat, even though it + + align:start position:0% +surface over the meat, even though it + + + align:start position:0% +surface over the meat, even though it +was on the plastic over the meat, it + + align:start position:0% +was on the plastic over the meat, it + + + align:start position:0% +was on the plastic over the meat, it +created a double barrier. And when you + + align:start position:0% +created a double barrier. And when you + + + align:start position:0% +created a double barrier. And when you +peeled the plastic off of the meat, you + + align:start position:0% +peeled the plastic off of the meat, you + + + align:start position:0% +peeled the plastic off of the meat, you +had a big purple spot there because meat + + align:start position:0% +had a big purple spot there because meat + + + align:start position:0% +had a big purple spot there because meat +turns red during oxygenation. All right? + + align:start position:0% +turns red during oxygenation. All right? + + + align:start position:0% +turns red during oxygenation. All right? +And so when you peel the tag off, + + align:start position:0% +And so when you peel the tag off, + + + align:start position:0% +And so when you peel the tag off, +because you have an oxygen barrier on + + align:start position:0% +because you have an oxygen barrier on + + + align:start position:0% +because you have an oxygen barrier on +top, you left a big purple splotch. And + + align:start position:0% +top, you left a big purple splotch. And + + + align:start position:0% +top, you left a big purple splotch. And +people were returning meats to the store + + align:start position:0% +people were returning meats to the store + + + align:start position:0% +people were returning meats to the store +saying, "This crap spoiled." And yet if + + align:start position:0% +saying, "This crap spoiled." And yet if + + + align:start position:0% +saying, "This crap spoiled." And yet if +they waited 20 minutes, it would + + align:start position:0% +they waited 20 minutes, it would + + + align:start position:0% +they waited 20 minutes, it would +disappear + + align:start position:0% +disappear + + + align:start position:0% +disappear +because the meat becomes oxygenated. + + align:start position:0% +because the meat becomes oxygenated. + + + align:start position:0% +because the meat becomes oxygenated. +Um frozen and refrigerated temperatures, + + align:start position:0% +Um frozen and refrigerated temperatures, + + + align:start position:0% +Um frozen and refrigerated temperatures, +I just gave you that. That's Johno. He's + + align:start position:0% +I just gave you that. That's Johno. He's + + + align:start position:0% +I just gave you that. That's Johno. He's +now at uh Kimberly Clark and APC uh + + align:start position:0% +now at uh Kimberly Clark and APC uh + + + align:start position:0% +now at uh Kimberly Clark and APC uh +member and task group on something. + + align:start position:0% +member and task group on something. + + + align:start position:0% +member and task group on something. +Um Jeff Tazzlar now with Simon wherever + + align:start position:0% +Um Jeff Tazzlar now with Simon wherever + + + align:start position:0% +Um Jeff Tazzlar now with Simon wherever +Simon went um effects of tag orientation + + align:start position:0% +Simon went um effects of tag orientation + + + align:start position:0% +Simon went um effects of tag orientation +and package content on readability. I + + align:start position:0% +and package content on readability. I + + + align:start position:0% +and package content on readability. I +have a slide on this that I'll share + + align:start position:0% +have a slide on this that I'll share + + + align:start position:0% +have a slide on this that I'll share +with you shortly. Um failure modes of + + align:start position:0% +with you shortly. Um failure modes of + + + align:start position:0% +with you shortly. Um failure modes of +class zero in the lab. When you look at + + align:start position:0% +class zero in the lab. When you look at + + + align:start position:0% +class zero in the lab. When you look at +ISTA, the uh institute um + + align:start position:0% +ISTA, the uh institute um + + + align:start position:0% +ISTA, the uh institute um +uh + + align:start position:0% +uh + + + align:start position:0% +uh +international safe transit association, + + align:start position:0% +international safe transit association, + + + align:start position:0% +international safe transit association, +excuse me, mental uh burp. + + align:start position:0% +excuse me, mental uh burp. + + + align:start position:0% +excuse me, mental uh burp. +Um, they run a series of dynamic tests + + align:start position:0% +Um, they run a series of dynamic tests + + + align:start position:0% +Um, they run a series of dynamic tests +uh that UPS, FedEx, uh, DHL may use for + + align:start position:0% +uh that UPS, FedEx, uh, DHL may use for + + + align:start position:0% +uh that UPS, FedEx, uh, DHL may use for +uh, liability issues. If something goes + + align:start position:0% +uh, liability issues. If something goes + + + align:start position:0% +uh, liability issues. If something goes +wrong with your package, they beat the + + align:start position:0% +wrong with your package, they beat the + + + align:start position:0% +wrong with your package, they beat the +hell out of it and the product has to + + align:start position:0% +hell out of it and the product has to + + + align:start position:0% +hell out of it and the product has to +survive. That's their test in a in a + + align:start position:0% +survive. That's their test in a in a + + + align:start position:0% +survive. That's their test in a in a +nutshell. Now, American Society of + + align:start position:0% +nutshell. Now, American Society of + + + align:start position:0% +nutshell. Now, American Society of +Testing Materials, ASM, also has a + + align:start position:0% +Testing Materials, ASM, also has a + + + align:start position:0% +Testing Materials, ASM, also has a +series of tests, shock, vibration, + + align:start position:0% +series of tests, shock, vibration, + + + align:start position:0% +series of tests, shock, vibration, +compression, and you can build your own + + align:start position:0% +compression, and you can build your own + + + align:start position:0% +compression, and you can build your own +distribution to fine-tune so you don't + + align:start position:0% +distribution to fine-tune so you don't + + + align:start position:0% +distribution to fine-tune so you don't +overpackage. We did both tests side by + + align:start position:0% +overpackage. We did both tests side by + + + align:start position:0% +overpackage. We did both tests side by +side with the same tags. And uh one of + + align:start position:0% +side with the same tags. And uh one of + + + align:start position:0% +side with the same tags. And uh one of +the interesting things we found was that + + align:start position:0% +the interesting things we found was that + + + align:start position:0% +the interesting things we found was that +it was really hard to kill them in + + align:start position:0% +it was really hard to kill them in + + + align:start position:0% +it was really hard to kill them in +transit unless there is a direct impact + + align:start position:0% +transit unless there is a direct impact + + + align:start position:0% +transit unless there is a direct impact +to the chip. The chips were not affected + + align:start position:0% +to the chip. The chips were not affected + + + align:start position:0% +to the chip. The chips were not affected +by vibration which surprised me. They + + align:start position:0% +by vibration which surprised me. They + + + align:start position:0% +by vibration which surprised me. They +were not affected by shock unless the + + align:start position:0% +were not affected by shock unless the + + + align:start position:0% +were not affected by shock unless the +shock was directly over the chip. And + + align:start position:0% +shock was directly over the chip. And + + + align:start position:0% +shock was directly over the chip. And +it's a brittle piece of silicon glass so + + align:start position:0% +it's a brittle piece of silicon glass so + + + align:start position:0% +it's a brittle piece of silicon glass so +it breaks. And here's why I did this + + align:start position:0% +it breaks. And here's why I did this + + + align:start position:0% +it breaks. And here's why I did this +earlier. Little trivia for you. It makes + + align:start position:0% +earlier. Little trivia for you. It makes + + + align:start position:0% +earlier. Little trivia for you. It makes +a difference for survivability + + align:start position:0% +a difference for survivability + + + align:start position:0% +a difference for survivability +whether the chip on a tag is over the + + align:start position:0% +whether the chip on a tag is over the + + + align:start position:0% +whether the chip on a tag is over the +peak, + + align:start position:0% +peak, + + + align:start position:0% +peak, +over the slope, + + align:start position:0% + + + + align:start position:0% + +or over the valley. + + align:start position:0% + + + + align:start position:0% + +Try and plan that into your automated uh + + align:start position:0% +Try and plan that into your automated uh + + + align:start position:0% +Try and plan that into your automated uh +system. + + align:start position:0% + + + + align:start position:0% + +Yes, + + align:start position:0% + + + + align:start position:0% + +I'll tell you later. + + align:start position:0% +I'll tell you later. + + + align:start position:0% +I'll tell you later. +Um, and we just finished one uh antenna + + align:start position:0% +Um, and we just finished one uh antenna + + + align:start position:0% +Um, and we just finished one uh antenna +configurations uh looking at product and + + align:start position:0% +configurations uh looking at product and + + + align:start position:0% +configurations uh looking at product and +tag types and we evaluated uh with the + + align:start position:0% +tag types and we evaluated uh with the + + + align:start position:0% +tag types and we evaluated uh with the +same readers and we looked at multiple + + align:start position:0% +same readers and we looked at multiple + + + align:start position:0% +same readers and we looked at multiple +readers. We looked at multiple classes + + align:start position:0% +readers. We looked at multiple classes + + + align:start position:0% +readers. We looked at multiple classes +of tags whether one antenna, two + + align:start position:0% +of tags whether one antenna, two + + + align:start position:0% +of tags whether one antenna, two +antenna, three antenna or four antenna + + align:start position:0% +antenna, three antenna or four antenna + + + align:start position:0% +antenna, three antenna or four antenna +gave better results and we looked at + + align:start position:0% +gave better results and we looked at + + + align:start position:0% +gave better results and we looked at +both uh linear and circular for + + align:start position:0% +both uh linear and circular for + + + align:start position:0% +both uh linear and circular for +different product mixes. So uh real + + align:start position:0% +different product mixes. So uh real + + + align:start position:0% +different product mixes. So uh real +interesting we hope to have that one + + align:start position:0% +interesting we hope to have that one + + + align:start position:0% +interesting we hope to have that one +published uh shortly because it's a + + align:start position:0% +published uh shortly because it's a + + + align:start position:0% +published uh shortly because it's a +fascinating study uh one that going on + + align:start position:0% +fascinating study uh one that going on + + + align:start position:0% +fascinating study uh one that going on +right now and uh Richard + + align:start position:0% +right now and uh Richard + + + align:start position:0% +right now and uh Richard +he disappeared. This is one I wanted to + + align:start position:0% +he disappeared. This is one I wanted to + + + align:start position:0% +he disappeared. This is one I wanted to +talk to him about. Electromagnetic + + align:start position:0% +talk to him about. Electromagnetic + + + align:start position:0% +talk to him about. Electromagnetic +property measurement and RF signal + + align:start position:0% +property measurement and RF signal + + + align:start position:0% +property measurement and RF signal +absorption evaluation for product + + align:start position:0% +absorption evaluation for product + + + align:start position:0% +absorption evaluation for product +simulant. + + align:start position:0% +simulant. + + + align:start position:0% +simulant. +I love these titles because they don't + + align:start position:0% +I love these titles because they don't + + + align:start position:0% +I love these titles because they don't +mean anything. But um we are evaluating + + align:start position:0% +mean anything. But um we are evaluating + + + align:start position:0% +mean anything. But um we are evaluating +how much the materials + + align:start position:0% +how much the materials + + + align:start position:0% +how much the materials +uh downgrade moving through various + + align:start position:0% +uh downgrade moving through various + + + align:start position:0% +uh downgrade moving through various +materials because they all have a + + align:start position:0% +materials because they all have a + + + align:start position:0% +materials because they all have a +different if you look at a freeze + + align:start position:0% +different if you look at a freeze + + + align:start position:0% +different if you look at a freeze +equation for those of you that know what + + align:start position:0% +equation for those of you that know what + + + align:start position:0% +equation for those of you that know what +I'm talking about. you have a signal + + align:start position:0% +I'm talking about. you have a signal + + + align:start position:0% +I'm talking about. you have a signal +strength and when it reaches a barrier + + align:start position:0% +strength and when it reaches a barrier + + + align:start position:0% +strength and when it reaches a barrier +if it's a packaging material you'll get + + align:start position:0% +if it's a packaging material you'll get + + + align:start position:0% +if it's a packaging material you'll get +a lessening as it crosses that barrier + + align:start position:0% +a lessening as it crosses that barrier + + + align:start position:0% +a lessening as it crosses that barrier +and you can actually measure these and + + align:start position:0% +and you can actually measure these and + + + align:start position:0% +and you can actually measure these and +we developed some new equipment to do + + align:start position:0% +we developed some new equipment to do + + + align:start position:0% +we developed some new equipment to do +that and it's coming out pretty + + align:start position:0% +that and it's coming out pretty + + + align:start position:0% +that and it's coming out pretty +interesting and then uh we did one on + + align:start position:0% +interesting and then uh we did one on + + + align:start position:0% +interesting and then uh we did one on +department of defense's RFID mandates + + align:start position:0% +department of defense's RFID mandates + + + align:start position:0% +department of defense's RFID mandates +blah blah blah this is the uh the chart + + align:start position:0% +blah blah blah this is the uh the chart + + + align:start position:0% +blah blah blah this is the uh the chart +that's kind of interesting on the one + + align:start position:0% +that's kind of interesting on the one + + + align:start position:0% +that's kind of interesting on the one +side here with the product + + align:start position:0% +side here with the product + + + align:start position:0% +side here with the product +you'll see that I have empty foam foam, + + align:start position:0% +you'll see that I have empty foam foam, + + + align:start position:0% +you'll see that I have empty foam foam, +empty bottles, rice and water bottles. + + align:start position:0% +empty bottles, rice and water bottles. + + + align:start position:0% +empty bottles, rice and water bottles. +Those are 12 by 12x 12 in cases, cubic + + align:start position:0% +Those are 12 by 12x 12 in cases, cubic + + + align:start position:0% +Those are 12 by 12x 12 in cases, cubic +foot with nothing in them, foam in them + + align:start position:0% +foot with nothing in them, foam in them + + + align:start position:0% +foot with nothing in them, foam in them +only because we were looking at some of + + align:start position:0% +only because we were looking at some of + + + align:start position:0% +only because we were looking at some of +the shipping uses. Empty PET bottles, + + align:start position:0% +the shipping uses. Empty PET bottles, + + + align:start position:0% +the shipping uses. Empty PET bottles, +rice in PET bottles, and filled water + + align:start position:0% +rice in PET bottles, and filled water + + + align:start position:0% +rice in PET bottles, and filled water +bottles, the same PET. And if you start + + align:start position:0% +bottles, the same PET. And if you start + + + align:start position:0% +bottles, the same PET. And if you start +going across the tag orientation at the + + align:start position:0% +going across the tag orientation at the + + + align:start position:0% +going across the tag orientation at the +top says outward-facing tags where we + + align:start position:0% +top says outward-facing tags where we + + + align:start position:0% +top says outward-facing tags where we +had as many tags facing outward as we + + align:start position:0% +had as many tags facing outward as we + + + align:start position:0% +had as many tags facing outward as we +could, inward facing tags, you'll see + + align:start position:0% +could, inward facing tags, you'll see + + + align:start position:0% +could, inward facing tags, you'll see +problems there. Forward-facing tags on + + align:start position:0% +problems there. Forward-facing tags on + + + align:start position:0% +problems there. Forward-facing tags on +the pallet, upward-facing tags on the + + align:start position:0% +the pallet, upward-facing tags on the + + + align:start position:0% +the pallet, upward-facing tags on the +pallet, and bottom base tags on the + + align:start position:0% +pallet, and bottom base tags on the + + + align:start position:0% +pallet, and bottom base tags on the +pallet. Um, one of the DHL uh uh movies, + + align:start position:0% +pallet. Um, one of the DHL uh uh movies, + + + align:start position:0% +pallet. Um, one of the DHL uh uh movies, +which I thought was interesting, when + + align:start position:0% +which I thought was interesting, when + + + align:start position:0% +which I thought was interesting, when +they left the tag on the product in the + + align:start position:0% +they left the tag on the product in the + + + align:start position:0% +they left the tag on the product in the +loading dock and the guy had to stop and + + align:start position:0% +loading dock and the guy had to stop and + + + align:start position:0% +loading dock and the guy had to stop and +run back and get it, the tag was sitting + + align:start position:0% +run back and get it, the tag was sitting + + + align:start position:0% +run back and get it, the tag was sitting +on the side so the reader could pick it + + align:start position:0% +on the side so the reader could pick it + + + align:start position:0% +on the side so the reader could pick it +up. If you took that same package and + + align:start position:0% +up. If you took that same package and + + + align:start position:0% +up. If you took that same package and +turn that tag down on the floor, chances + + align:start position:0% +turn that tag down on the floor, chances + + + align:start position:0% +turn that tag down on the floor, chances +are the reader wouldn't get it. Why? + + align:start position:0% +are the reader wouldn't get it. Why? + + + align:start position:0% +are the reader wouldn't get it. Why? +There's metal in the floor. Because when + + align:start position:0% +There's metal in the floor. Because when + + + align:start position:0% +There's metal in the floor. Because when +you build facilities, you put rebar down + + align:start position:0% +you build facilities, you put rebar down + + + align:start position:0% +you build facilities, you put rebar down +there and it scatters waves all over + + align:start position:0% +there and it scatters waves all over + + + align:start position:0% +there and it scatters waves all over +hell. So anyway, this just shows that + + align:start position:0% +hell. So anyway, this just shows that + + + align:start position:0% +hell. So anyway, this just shows that +the white are good reads. This is 1,200 + + align:start position:0% +the white are good reads. This is 1,200 + + + align:start position:0% +the white are good reads. This is 1,200 +reads in for each test. Each box is + + align:start position:0% +reads in for each test. Each box is + + + align:start position:0% +reads in for each test. Each box is +1,200 reads and uh percentages of reads. + + align:start position:0% +1,200 reads and uh percentages of reads. + + + align:start position:0% +1,200 reads and uh percentages of reads. +And you can see that the white to the + + align:start position:0% +And you can see that the white to the + + + align:start position:0% +And you can see that the white to the +red you had orientation issues, not a + + align:start position:0% +red you had orientation issues, not a + + + align:start position:0% +red you had orientation issues, not a +lot but statistically significant. And + + align:start position:0% +lot but statistically significant. And + + + align:start position:0% +lot but statistically significant. And +in the uh product categories as you + + align:start position:0% +in the uh product categories as you + + + align:start position:0% +in the uh product categories as you +moved across, you had certain + + align:start position:0% +moved across, you had certain + + + align:start position:0% +moved across, you had certain +orientations of the tags on cases that + + align:start position:0% +orientations of the tags on cases that + + + align:start position:0% +orientations of the tags on cases that +were problematic. And when you looked at + + align:start position:0% +were problematic. And when you looked at + + + align:start position:0% +were problematic. And when you looked at +both of those areas, the orange squares + + align:start position:0% +both of those areas, the orange squares + + + align:start position:0% +both of those areas, the orange squares +up there did come out orange. + + align:start position:0% +up there did come out orange. + + + align:start position:0% +up there did come out orange. +Real problems, packaging and product + + align:start position:0% +Real problems, packaging and product + + + align:start position:0% +Real problems, packaging and product +issues that affect RFID, readability, + + align:start position:0% +issues that affect RFID, readability, + + + align:start position:0% +issues that affect RFID, readability, +transmission, any number of words you + + align:start position:0% +transmission, any number of words you + + + align:start position:0% +transmission, any number of words you +want to put in there. Now again, this is + + align:start position:0% +want to put in there. Now again, this is + + + align:start position:0% +want to put in there. Now again, this is +Richard's and I won't this is some of + + align:start position:0% +Richard's and I won't this is some of + + + align:start position:0% +Richard's and I won't this is some of +the stuff we're doing on the + + align:start position:0% +the stuff we're doing on the + + + align:start position:0% +the stuff we're doing on the +electromagnetic properties and being + + align:start position:0% +electromagnetic properties and being + + + align:start position:0% +electromagnetic properties and being +able to measure energy that gets through + + align:start position:0% +able to measure energy that gets through + + + align:start position:0% +able to measure energy that gets through +packaging to a tag and uh being able to + + align:start position:0% +packaging to a tag and uh being able to + + + align:start position:0% +packaging to a tag and uh being able to +measure how much energy it takes to + + align:start position:0% +measure how much energy it takes to + + + align:start position:0% +measure how much energy it takes to +breach the threshold for a passive tag + + align:start position:0% +breach the threshold for a passive tag + + + align:start position:0% +breach the threshold for a passive tag +to send a signal back and uh it's a it's + + align:start position:0% +to send a signal back and uh it's a it's + + + align:start position:0% +to send a signal back and uh it's a it's +a neat um we can talk about that later. + + align:start position:0% +a neat um we can talk about that later. + + + align:start position:0% +a neat um we can talk about that later. +Now, corrugated board. All right. + + align:start position:0% +Now, corrugated board. All right. + + + align:start position:0% +Now, corrugated board. All right. +When you add humidity to paper, it's a + + align:start position:0% +When you add humidity to paper, it's a + + + align:start position:0% +When you add humidity to paper, it's a +hyroscopic paper. It absorbs moisture to + + align:start position:0% +hyroscopic paper. It absorbs moisture to + + + align:start position:0% +hyroscopic paper. It absorbs moisture to +some level. It changes the moisture + + align:start position:0% +some level. It changes the moisture + + + align:start position:0% +some level. It changes the moisture +content. And if you see here, we have + + align:start position:0% +content. And if you see here, we have + + + align:start position:0% +content. And if you see here, we have +storage conditions, three different + + align:start position:0% +storage conditions, three different + + + align:start position:0% +storage conditions, three different +storage conditions, three different + + align:start position:0% +storage conditions, three different + + + align:start position:0% +storage conditions, three different +moisture contents associated with that. + + align:start position:0% +moisture contents associated with that. + + + align:start position:0% +moisture contents associated with that. +And guess what happens? As you go up in + + align:start position:0% +And guess what happens? As you go up in + + + align:start position:0% +And guess what happens? As you go up in +moisture content, you start having an + + align:start position:0% +moisture content, you start having an + + + align:start position:0% +moisture content, you start having an +effect on the paper. + + align:start position:0% +effect on the paper. + + + align:start position:0% +effect on the paper. +Now, + + align:start position:0% +Now, + + + align:start position:0% +Now, +doesn't look like much, but what it + + align:start position:0% +doesn't look like much, but what it + + + align:start position:0% +doesn't look like much, but what it +boils down to is corrugated board or any + + align:start position:0% +boils down to is corrugated board or any + + + align:start position:0% +boils down to is corrugated board or any +other paper, all right, can affect RFID. + + align:start position:0% +other paper, all right, can affect RFID. + + + align:start position:0% +other paper, all right, can affect RFID. +It does not say it will. It does not say + + align:start position:0% +It does not say it will. It does not say + + + align:start position:0% +It does not say it will. It does not say +it has to. It can when you have high + + align:start position:0% +it has to. It can when you have high + + + align:start position:0% +it has to. It can when you have high +humidity. + + align:start position:0% +humidity. + + + align:start position:0% +humidity. +If you have low to medium humidity, but + + align:start position:0% +If you have low to medium humidity, but + + + align:start position:0% +If you have low to medium humidity, but +the paper has already been exposed to + + align:start position:0% +the paper has already been exposed to + + + align:start position:0% +the paper has already been exposed to +high humidity. Hysteresus is a saying + + align:start position:0% +high humidity. Hysteresus is a saying + + + align:start position:0% +high humidity. Hysteresus is a saying +Mark and I had a conference in Tokyo + + align:start position:0% +Mark and I had a conference in Tokyo + + + align:start position:0% +Mark and I had a conference in Tokyo +where we discussed this very topic. When + + align:start position:0% +where we discussed this very topic. When + + + align:start position:0% +where we discussed this very topic. When +you uh change a paper's uh u uh + + align:start position:0% +you uh change a paper's uh u uh + + + align:start position:0% +you uh change a paper's uh u uh +chemistry by adding moisture and then + + align:start position:0% +chemistry by adding moisture and then + + + align:start position:0% +chemistry by adding moisture and then +dry it out, it never goes back to the + + align:start position:0% +dry it out, it never goes back to the + + + align:start position:0% +dry it out, it never goes back to the +same static condition. There's always a + + align:start position:0% +same static condition. There's always a + + + align:start position:0% +same static condition. There's always a +residual there. So, it's easier to pick + + align:start position:0% +residual there. So, it's easier to pick + + + align:start position:0% +residual there. So, it's easier to pick +up moisture the second time around. Uh + + align:start position:0% +up moisture the second time around. Uh + + + align:start position:0% +up moisture the second time around. Uh +so, with leakage or condensation, that's + + align:start position:0% +so, with leakage or condensation, that's + + + align:start position:0% +so, with leakage or condensation, that's +an issue. If you guys are trying to ship + + align:start position:0% +an issue. If you guys are trying to ship + + + align:start position:0% +an issue. If you guys are trying to ship +down to uh help Katrina in the uh uh + + align:start position:0% +down to uh help Katrina in the uh uh + + + align:start position:0% +down to uh help Katrina in the uh uh +southern coast where it literally rains + + align:start position:0% +southern coast where it literally rains + + + align:start position:0% +southern coast where it literally rains +inside of warehouses in the summer, this + + align:start position:0% +inside of warehouses in the summer, this + + + align:start position:0% +inside of warehouses in the summer, this +could be an issue. + + align:start position:0% +could be an issue. + + + align:start position:0% +could be an issue. +However, and here's an interesting + + align:start position:0% +However, and here's an interesting + + + align:start position:0% +However, and here's an interesting +point. I hear this a lot in my + + align:start position:0% +point. I hear this a lot in my + + + align:start position:0% +point. I hear this a lot in my +presentations. That means we should go + + align:start position:0% +presentations. That means we should go + + + align:start position:0% +presentations. That means we should go +to RPCs, returnable plastic containers, + + align:start position:0% +to RPCs, returnable plastic containers, + + + align:start position:0% +to RPCs, returnable plastic containers, +or actually there's about five acronyms + + align:start position:0% +or actually there's about five acronyms + + + align:start position:0% +or actually there's about five acronyms +for RPCs depending on the industry + + align:start position:0% +for RPCs depending on the industry + + + align:start position:0% +for RPCs depending on the industry +you're talking to. And here's one of the + + align:start position:0% +you're talking to. And here's one of the + + + align:start position:0% +you're talking to. And here's one of the +things that I find with that. If you do, + + align:start position:0% +things that I find with that. If you do, + + + align:start position:0% +things that I find with that. If you do, +and you can, they'll go, you can embed + + align:start position:0% +and you can, they'll go, you can embed + + + align:start position:0% +and you can, they'll go, you can embed +the tag. Absolutely right. No question. + + align:start position:0% +the tag. Absolutely right. No question. + + + align:start position:0% +the tag. Absolutely right. No question. +You can embed the tag and it's + + align:start position:0% +You can embed the tag and it's + + + align:start position:0% +You can embed the tag and it's +protected. Those are good things. You + + align:start position:0% +protected. Those are good things. You + + + align:start position:0% +protected. Those are good things. You +can embed the tag in corrugated, too. + + align:start position:0% +can embed the tag in corrugated, too. + + + align:start position:0% +can embed the tag in corrugated, too. +Um, I don't I have to look ahead. Don't + + align:start position:0% +Um, I don't I have to look ahead. Don't + + + align:start position:0% +Um, I don't I have to look ahead. Don't +look. Okay, good. Um, if you embed the + + align:start position:0% +look. Okay, good. Um, if you embed the + + + align:start position:0% +look. Okay, good. Um, if you embed the +tag in corrugated, there's a problem + + align:start position:0% +tag in corrugated, there's a problem + + + align:start position:0% +tag in corrugated, there's a problem +with that inherently from an operation + + align:start position:0% +with that inherently from an operation + + + align:start position:0% +with that inherently from an operation +standpoint because you embed it and + + align:start position:0% +standpoint because you embed it and + + + align:start position:0% +standpoint because you embed it and +those of you that have been in a + + align:start position:0% +those of you that have been in a + + + align:start position:0% +those of you that have been in a +corrugated plant, you see this stuff + + align:start position:0% +corrugated plant, you see this stuff + + + align:start position:0% +corrugated plant, you see this stuff +whipping off and you place tags every so + + align:start position:0% +whipping off and you place tags every so + + + align:start position:0% +whipping off and you place tags every so +often. You then have to die cut to get + + align:start position:0% +often. You then have to die cut to get + + + align:start position:0% +often. You then have to die cut to get +that box blank. And if you're changing + + align:start position:0% +that box blank. And if you're changing + + + align:start position:0% +that box blank. And if you're changing +the die, + + align:start position:0% +the die, + + + align:start position:0% +the die, +you don't know what's going to happen to + + align:start position:0% +you don't know what's going to happen to + + + align:start position:0% +you don't know what's going to happen to +that tag. So, that's really problematic. + + align:start position:0% +that tag. So, that's really problematic. + + + align:start position:0% +that tag. So, that's really problematic. +That means you end up having to + + align:start position:0% +That means you end up having to + + + align:start position:0% +That means you end up having to +inventory 8-ft sheets of board rather + + align:start position:0% +inventory 8-ft sheets of board rather + + + align:start position:0% +inventory 8-ft sheets of board rather +than diecut blanks or diecut uh boxes. + + align:start position:0% +than diecut blanks or diecut uh boxes. + + + align:start position:0% +than diecut blanks or diecut uh boxes. +That's a huge amount of space increase. + + align:start position:0% +That's a huge amount of space increase. + + + align:start position:0% +That's a huge amount of space increase. +All right. Now, the other thing that + + align:start position:0% +All right. Now, the other thing that + + + align:start position:0% +All right. Now, the other thing that +well, okay, with RPCs, I'll I'll cover + + align:start position:0% +well, okay, with RPCs, I'll I'll cover + + + align:start position:0% +well, okay, with RPCs, I'll I'll cover +that in a second. Uh don't let me + + align:start position:0% +that in a second. Uh don't let me + + + align:start position:0% +that in a second. Uh don't let me +forget. These are just some of our test + + align:start position:0% +forget. These are just some of our test + + + align:start position:0% +forget. These are just some of our test +conditions. We have loading docks at the + + align:start position:0% +conditions. We have loading docks at the + + + align:start position:0% +conditions. We have loading docks at the +school. Um and in the bottom corner over + + align:start position:0% +school. Um and in the bottom corner over + + + align:start position:0% +school. Um and in the bottom corner over +here, you'll see uh one of my labs. And + + align:start position:0% +here, you'll see uh one of my labs. And + + + align:start position:0% +here, you'll see uh one of my labs. And +uh I run that. I just put the corugated + + align:start position:0% +uh I run that. I just put the corugated + + + align:start position:0% +uh I run that. I just put the corugated +up to make it look clean because it's a + + align:start position:0% +up to make it look clean because it's a + + + align:start position:0% +up to make it look clean because it's a +dirty lab, if you will, literally and + + align:start position:0% +dirty lab, if you will, literally and + + + align:start position:0% +dirty lab, if you will, literally and +figuratively. Um, but we'll turn on all + + align:start position:0% +figuratively. Um, but we'll turn on all + + + align:start position:0% +figuratively. Um, but we'll turn on all +the equipment and see what + + align:start position:0% +the equipment and see what + + + align:start position:0% +the equipment and see what +electromagnetic interference uh does + + align:start position:0% +electromagnetic interference uh does + + + align:start position:0% +electromagnetic interference uh does +with respect to different tag and reader + + align:start position:0% +with respect to different tag and reader + + + align:start position:0% +with respect to different tag and reader +combinations. + + align:start position:0% +combinations. + + + align:start position:0% +combinations. +We did shock testing. Okay, so we're + + align:start position:0% +We did shock testing. Okay, so we're + + + align:start position:0% +We did shock testing. Okay, so we're +doing drops on here. Here's a vibration + + align:start position:0% +doing drops on here. Here's a vibration + + + align:start position:0% +doing drops on here. Here's a vibration +test unit load as well as column stack + + align:start position:0% +test unit load as well as column stack + + + align:start position:0% +test unit load as well as column stack +where we're trying to get the columns + + align:start position:0% +where we're trying to get the columns + + + align:start position:0% +where we're trying to get the columns +rubbing against each other to see if we + + align:start position:0% +rubbing against each other to see if we + + + align:start position:0% +rubbing against each other to see if we +could araid through to destroy the chip. + + align:start position:0% +could araid through to destroy the chip. + + + align:start position:0% +could araid through to destroy the chip. +compression tests. You can do these all + + align:start position:0% +compression tests. You can do these all + + + align:start position:0% +compression tests. You can do these all +day long. Nothing ever happens, but + + align:start position:0% +day long. Nothing ever happens, but + + + align:start position:0% +day long. Nothing ever happens, but +they're cool to look at. Um, now here's + + align:start position:0% +they're cool to look at. Um, now here's + + + align:start position:0% +they're cool to look at. Um, now here's +some issues that we also found in + + align:start position:0% +some issues that we also found in + + + align:start position:0% +some issues that we also found in +looking at a lot of product package + + align:start position:0% +looking at a lot of product package + + + align:start position:0% +looking at a lot of product package +combinations. This is a seven down + + align:start position:0% +combinations. This is a seven down + + + align:start position:0% +combinations. This is a seven down +footprint, four and three cases. And the + + align:start position:0% +footprint, four and three cases. And the + + + align:start position:0% +footprint, four and three cases. And the +white means you got 100% reads in um + + align:start position:0% +white means you got 100% reads in um + + + align:start position:0% +white means you got 100% reads in um +25 trials going through a portal. And + + align:start position:0% +25 trials going through a portal. And + + + align:start position:0% +25 trials going through a portal. And +you have the red with various + + align:start position:0% +you have the red with various + + + align:start position:0% +you have the red with various +percentages up there. Those tags didn't + + align:start position:0% +percentages up there. Those tags didn't + + + align:start position:0% +percentages up there. Those tags didn't +read, but they're all perimeter tags, + + align:start position:0% +read, but they're all perimeter tags, + + + align:start position:0% +read, but they're all perimeter tags, +and they didn't read because + + align:start position:0% +and they didn't read because + + + align:start position:0% +and they didn't read because +metal forklift blocked the RF from + + align:start position:0% +metal forklift blocked the RF from + + + align:start position:0% +metal forklift blocked the RF from +getting to them. I don't have it in + + align:start position:0% +getting to them. I don't have it in + + + align:start position:0% +getting to them. I don't have it in +here. We did a lot of studies on how + + align:start position:0% +here. We did a lot of studies on how + + + align:start position:0% +here. We did a lot of studies on how +much room do you need to measure in that + + align:start position:0% +much room do you need to measure in that + + + align:start position:0% +much room do you need to measure in that +gap and reflect off, but it's a + + align:start position:0% +gap and reflect off, but it's a + + + align:start position:0% +gap and reflect off, but it's a +different. Now, on the bottom is the + + align:start position:0% +different. Now, on the bottom is the + + + align:start position:0% +different. Now, on the bottom is the +exact same product, the exact same cases + + align:start position:0% +exact same product, the exact same cases + + + align:start position:0% +exact same product, the exact same cases +and tags, but I changed the stacking + + align:start position:0% +and tags, but I changed the stacking + + + align:start position:0% +and tags, but I changed the stacking +pattern. + + align:start position:0% +pattern. + + + align:start position:0% +pattern. +I agree. It is a stacking pattern that + + align:start position:0% +I agree. It is a stacking pattern that + + + align:start position:0% +I agree. It is a stacking pattern that +rhymes with It's a terrible + + align:start position:0% +rhymes with It's a terrible + + + align:start position:0% +rhymes with It's a terrible +pattern. You'd never use this. However, + + align:start position:0% +pattern. You'd never use this. However, + + + align:start position:0% +pattern. You'd never use this. However, +my point was to demonstrate that if you + + align:start position:0% +my point was to demonstrate that if you + + + align:start position:0% +my point was to demonstrate that if you +change stacking patterns, it can impact + + align:start position:0% +change stacking patterns, it can impact + + + align:start position:0% +change stacking patterns, it can impact +readability. That's all I wanted to + + align:start position:0% +readability. That's all I wanted to + + + align:start position:0% +readability. That's all I wanted to +prove. + + align:start position:0% +prove. + + + align:start position:0% +prove. +Now, here's one where the green is the + + align:start position:0% +Now, here's one where the green is the + + + align:start position:0% +Now, here's one where the green is the +tag location on these cases. And we have + + align:start position:0% +tag location on these cases. And we have + + + align:start position:0% +tag location on these cases. And we have +the same orientation, the same patterns. + + align:start position:0% +the same orientation, the same patterns. + + + align:start position:0% +the same orientation, the same patterns. +And I just turned the tags inward rather + + align:start position:0% +And I just turned the tags inward rather + + + align:start position:0% +And I just turned the tags inward rather +than leaving them at the perimeter. And + + align:start position:0% +than leaving them at the perimeter. And + + + align:start position:0% +than leaving them at the perimeter. And +those red reads, 25 trials, not a single + + align:start position:0% +those red reads, 25 trials, not a single + + + align:start position:0% +those red reads, 25 trials, not a single +time that case read. These are + + align:start position:0% +time that case read. These are + + + align:start position:0% +time that case read. These are +individual uh tiers stacked on top of + + align:start position:0% +individual uh tiers stacked on top of + + + align:start position:0% +individual uh tiers stacked on top of +each other. Same with the bottom ones, + + align:start position:0% +each other. Same with the bottom ones, + + + align:start position:0% +each other. Same with the bottom ones, +even though you have the channels into + + align:start position:0% +even though you have the channels into + + + align:start position:0% +even though you have the channels into +the tags. + + align:start position:0% +the tags. + + + align:start position:0% +the tags. +Okay. Now, here's just kind of a + + align:start position:0% +Okay. Now, here's just kind of a + + + align:start position:0% +Okay. Now, here's just kind of a +reversed all perimeter tags on the top + + align:start position:0% +reversed all perimeter tags on the top + + + align:start position:0% +reversed all perimeter tags on the top +one. good readability like no failures + + align:start position:0% +one. good readability like no failures + + + align:start position:0% +one. good readability like no failures +that's real handy inward-f facing tags + + align:start position:0% +that's real handy inward-f facing tags + + + align:start position:0% +that's real handy inward-f facing tags +death except on the top where there was + + align:start position:0% +death except on the top where there was + + + align:start position:0% +death except on the top where there was +no case surrounding it now what this + + align:start position:0% +no case surrounding it now what this + + + align:start position:0% +no case surrounding it now what this +means and you know we've done a lot of + + align:start position:0% +means and you know we've done a lot of + + + align:start position:0% +means and you know we've done a lot of +talking on processes here one of the + + align:start position:0% +talking on processes here one of the + + + align:start position:0% +talking on processes here one of the +processes that may have to occur before + + align:start position:0% +processes that may have to occur before + + + align:start position:0% +processes that may have to occur before +RFID enables all the benefits we're + + align:start position:0% +RFID enables all the benefits we're + + + align:start position:0% +RFID enables all the benefits we're +talking about in the supply chain is to + + align:start position:0% +talking about in the supply chain is to + + + align:start position:0% +talking about in the supply chain is to +look at changing the pallet patterns or + + align:start position:0% +look at changing the pallet patterns or + + + align:start position:0% +look at changing the pallet patterns or +case counts to match maximize perimeter + + align:start position:0% +case counts to match maximize perimeter + + + align:start position:0% +case counts to match maximize perimeter +tagging. In the video that DHL showed, + + align:start position:0% +tagging. In the video that DHL showed, + + + align:start position:0% +tagging. In the video that DHL showed, +did anybody notice that that pallet was + + align:start position:0% +did anybody notice that that pallet was + + + align:start position:0% +did anybody notice that that pallet was +a half pallet? It wasn't a typical uh + + align:start position:0% +a half pallet? It wasn't a typical uh + + + align:start position:0% +a half pallet? It wasn't a typical uh +GMA pallet like we use here in the + + align:start position:0% +GMA pallet like we use here in the + + + align:start position:0% +GMA pallet like we use here in the +United States, Grocery Manufacturers + + align:start position:0% +United States, Grocery Manufacturers + + + align:start position:0% +United States, Grocery Manufacturers +Association, a 40x 48 inch pallet. It + + align:start position:0% +Association, a 40x 48 inch pallet. It + + + align:start position:0% +Association, a 40x 48 inch pallet. It +was a half pallet. And if you go through + + align:start position:0% +was a half pallet. And if you go through + + + align:start position:0% +was a half pallet. And if you go through +Europe, you'll also see quarter pallets. + + align:start position:0% +Europe, you'll also see quarter pallets. + + + align:start position:0% +Europe, you'll also see quarter pallets. +And one of the benefits of that system + + align:start position:0% +And one of the benefits of that system + + + align:start position:0% +And one of the benefits of that system +is you always almost always pretty much + + align:start position:0% +is you always almost always pretty much + + + align:start position:0% +is you always almost always pretty much +always get that perimeter tagging + + align:start position:0% +always get that perimeter tagging + + + align:start position:0% +always get that perimeter tagging +opportunity and therefore better + + align:start position:0% +opportunity and therefore better + + + align:start position:0% +opportunity and therefore better +readability. + + align:start position:0% +readability. + + + align:start position:0% +readability. +Now product impact water we tested some + + align:start position:0% +Now product impact water we tested some + + + align:start position:0% +Now product impact water we tested some +and we found a case that would be + + align:start position:0% +and we found a case that would be + + + align:start position:0% +and we found a case that would be +readable non-readable readable + + align:start position:0% +readable non-readable readable + + + align:start position:0% +readable non-readable readable +non-readable nothing changed. What the + + align:start position:0% +non-readable nothing changed. What the + + + align:start position:0% +non-readable nothing changed. What the +hell's going on? I'm going crazy here. + + align:start position:0% +hell's going on? I'm going crazy here. + + + align:start position:0% +hell's going on? I'm going crazy here. +All right. What we found was we had + + align:start position:0% +All right. What we found was we had + + + align:start position:0% +All right. What we found was we had +heads of lettuce and a head of lettuce + + align:start position:0% +heads of lettuce and a head of lettuce + + + align:start position:0% +heads of lettuce and a head of lettuce +would rotate and put a flat portion of + + align:start position:0% +would rotate and put a flat portion of + + + align:start position:0% +would rotate and put a flat portion of +the head on the back side of the case + + align:start position:0% +the head on the back side of the case + + + align:start position:0% +the head on the back side of the case +where the tag was. And if that hunk of + + align:start position:0% +where the tag was. And if that hunk of + + + align:start position:0% +where the tag was. And if that hunk of +water in a lettuce was up against the + + align:start position:0% +water in a lettuce was up against the + + + align:start position:0% +water in a lettuce was up against the +corrugated behind the tag, you can't + + align:start position:0% +corrugated behind the tag, you can't + + + align:start position:0% +corrugated behind the tag, you can't +read the tag. And that was demonstrated + + align:start position:0% +read the tag. And that was demonstrated + + + align:start position:0% +read the tag. And that was demonstrated +last night with the different + + align:start position:0% +last night with the different + + + align:start position:0% +last night with the different +thicknesses on the uh water with Dan. + + align:start position:0% +thicknesses on the uh water with Dan. + + + align:start position:0% +thicknesses on the uh water with Dan. +When you rotated the uh uh tray full of + + align:start position:0% +When you rotated the uh uh tray full of + + + align:start position:0% +When you rotated the uh uh tray full of +water, you needed additional thicknesses + + align:start position:0% +water, you needed additional thicknesses + + + align:start position:0% +water, you needed additional thicknesses +because you need to separate the tag + + align:start position:0% +because you need to separate the tag + + + align:start position:0% +because you need to separate the tag +from the water to allow the signal to + + align:start position:0% +from the water to allow the signal to + + + align:start position:0% +from the water to allow the signal to +get in and energize the uh antenna. And + + align:start position:0% +get in and energize the uh antenna. And + + + align:start position:0% +get in and energize the uh antenna. And +here's a perfect example. We found it in + + align:start position:0% +here's a perfect example. We found it in + + + align:start position:0% +here's a perfect example. We found it in +lettuce. We found it in peaches. We + + align:start position:0% +lettuce. We found it in peaches. We + + + align:start position:0% +lettuce. We found it in peaches. We +found it in a couple different products. + + align:start position:0% +found it in a couple different products. + + + align:start position:0% +found it in a couple different products. +We started looking at uh reading on + + align:start position:0% +We started looking at uh reading on + + + align:start position:0% +We started looking at uh reading on +shrink wrap uh situations, stretch wrap, + + align:start position:0% +shrink wrap uh situations, stretch wrap, + + + align:start position:0% +shrink wrap uh situations, stretch wrap, +excuse me. And this is a portal that has + + align:start position:0% +excuse me. And this is a portal that has + + + align:start position:0% +excuse me. And this is a portal that has +four antenna. This is part of the uh + + align:start position:0% +four antenna. This is part of the uh + + + align:start position:0% +four antenna. This is part of the uh +antenna configuration and and + + align:start position:0% +antenna configuration and and + + + align:start position:0% +antenna configuration and and +readability and uh reading while it's + + align:start position:0% +readability and uh reading while it's + + + align:start position:0% +readability and uh reading while it's +because it's on there for roughly uh 30 + + align:start position:0% +because it's on there for roughly uh 30 + + + align:start position:0% +because it's on there for roughly uh 30 +seconds while the uh uh uh stretch wrap + + align:start position:0% +seconds while the uh uh uh stretch wrap + + + align:start position:0% +seconds while the uh uh uh stretch wrap +is being put on. And uh we found some + + align:start position:0% +is being put on. And uh we found some + + + align:start position:0% +is being put on. And uh we found some +some fun results, but that'll be out + + align:start position:0% +some fun results, but that'll be out + + + align:start position:0% +some fun results, but that'll be out +shortly and I'll I'll tease you all with + + align:start position:0% +shortly and I'll I'll tease you all with + + + align:start position:0% +shortly and I'll I'll tease you all with +that. One of the things we're currently + + align:start position:0% +that. One of the things we're currently + + + align:start position:0% +that. One of the things we're currently +doing now is looking at water on + + align:start position:0% +doing now is looking at water on + + + align:start position:0% +doing now is looking at water on +corrugated. Corrugated has huge markets + + align:start position:0% +corrugated. Corrugated has huge markets + + + align:start position:0% +corrugated. Corrugated has huge markets +and opportunities within produce. No + + align:start position:0% +and opportunities within produce. No + + + align:start position:0% +and opportunities within produce. No +question about it. And here we've + + align:start position:0% +question about it. And here we've + + + align:start position:0% +question about it. And here we've +started a series of tests on these. We + + align:start position:0% +started a series of tests on these. We + + + align:start position:0% +started a series of tests on these. We +have produce trays. And in the top we + + align:start position:0% +have produce trays. And in the top we + + + align:start position:0% +have produce trays. And in the top we +just have a squeeze bottle. Real + + align:start position:0% +just have a squeeze bottle. Real + + + align:start position:0% +just have a squeeze bottle. Real +scientific. Cost me I think 89 cents to + + align:start position:0% +scientific. Cost me I think 89 cents to + + + align:start position:0% +scientific. Cost me I think 89 cents to +empty and fill up with water. And we + + align:start position:0% +empty and fill up with water. And we + + + align:start position:0% +empty and fill up with water. And we +spray on the tag. Okay. And the one + + align:start position:0% +spray on the tag. Okay. And the one + + + align:start position:0% +spray on the tag. Okay. And the one +below that we got a squeeze bottle. That + + align:start position:0% +below that we got a squeeze bottle. That + + + align:start position:0% +below that we got a squeeze bottle. That +was cheaper. That was like 39 cents. and + + align:start position:0% +was cheaper. That was like 39 cents. and + + + align:start position:0% +was cheaper. That was like 39 cents. and +we just squeeze a stream on it. Now, on + + align:start position:0% +we just squeeze a stream on it. Now, on + + + align:start position:0% +we just squeeze a stream on it. Now, on +the top, we run a tap and we have a + + align:start position:0% +the top, we run a tap and we have a + + + align:start position:0% +the top, we run a tap and we have a +calibrated hand splashing water across + + align:start position:0% +calibrated hand splashing water across + + + align:start position:0% +calibrated hand splashing water across +the tag, looking at different levels of + + align:start position:0% +the tag, looking at different levels of + + + align:start position:0% +the tag, looking at different levels of +moisture on the tag. And here's one of + + align:start position:0% +moisture on the tag. And here's one of + + + align:start position:0% +moisture on the tag. And here's one of +the interesting things that we found. If + + align:start position:0% +the interesting things that we found. If + + + align:start position:0% +the interesting things that we found. If +you have untreated board, any water on + + align:start position:0% +you have untreated board, any water on + + + align:start position:0% +you have untreated board, any water on +the tag, the tag disappears. You can't + + align:start position:0% +the tag, the tag disappears. You can't + + + align:start position:0% +the tag, the tag disappears. You can't +read it. Okay? And in the bottom + + align:start position:0% +read it. Okay? And in the bottom + + + align:start position:0% +read it. Okay? And in the bottom +picture, you see how the water has + + align:start position:0% +picture, you see how the water has + + + align:start position:0% +picture, you see how the water has +worked its way into some of the holes of + + align:start position:0% +worked its way into some of the holes of + + + align:start position:0% +worked its way into some of the holes of +the case. + + align:start position:0% +the case. + + + align:start position:0% +the case. +it holds moisture, you still have + + align:start position:0% +it holds moisture, you still have + + + align:start position:0% +it holds moisture, you still have +problems and you can't always read those + + align:start position:0% +problems and you can't always read those + + + align:start position:0% +problems and you can't always read those +after the water application stops. + + align:start position:0% +after the water application stops. + + + align:start position:0% +after the water application stops. +However, if you have treated board and + + align:start position:0% +However, if you have treated board and + + + align:start position:0% +However, if you have treated board and +you do this exact test, as soon as you + + align:start position:0% +you do this exact test, as soon as you + + + align:start position:0% +you do this exact test, as soon as you +stop the water, whether it's a spray, a + + align:start position:0% +stop the water, whether it's a spray, a + + + align:start position:0% +stop the water, whether it's a spray, a +squeeze bottle, or a flood of water, the + + align:start position:0% +squeeze bottle, or a flood of water, the + + + align:start position:0% +squeeze bottle, or a flood of water, the +second you stop that water and it + + align:start position:0% +second you stop that water and it + + + align:start position:0% +second you stop that water and it +drains, that tag reads again. That is no + + align:start position:0% +drains, that tag reads again. That is no + + + align:start position:0% +drains, that tag reads again. That is no +different than a tag embedded in a + + align:start position:0% +different than a tag embedded in a + + + align:start position:0% +different than a tag embedded in a +returnable plastic container. If you run + + align:start position:0% +returnable plastic container. If you run + + + align:start position:0% +returnable plastic container. If you run +water over those, the tag still + + align:start position:0% +water over those, the tag still + + + align:start position:0% +water over those, the tag still +disappears. + + align:start position:0% +disappears. + + + align:start position:0% +disappears. +There's no magic that if you bury a tag + + align:start position:0% +There's no magic that if you bury a tag + + + align:start position:0% +There's no magic that if you bury a tag +in plastic, you can still spray it with + + align:start position:0% +in plastic, you can still spray it with + + + align:start position:0% +in plastic, you can still spray it with +water and get the tag to read. You can + + align:start position:0% +water and get the tag to read. You can + + + align:start position:0% +water and get the tag to read. You can +spray it with water for cleaning. But + + align:start position:0% +spray it with water for cleaning. But + + + align:start position:0% +spray it with water for cleaning. But +here was an interesting thing. My wife + + align:start position:0% +here was an interesting thing. My wife + + + align:start position:0% +here was an interesting thing. My wife +is here with me and I was talking to her + + align:start position:0% +is here with me and I was talking to her + + + align:start position:0% +is here with me and I was talking to her +about returnable containers and she + + align:start position:0% +about returnable containers and she + + + align:start position:0% +about returnable containers and she +worked for a company in Dallas. + + align:start position:0% +worked for a company in Dallas. + + + align:start position:0% +worked for a company in Dallas. +We made a one-way container for a + + align:start position:0% +We made a one-way container for a + + + align:start position:0% +We made a one-way container for a +company and it was electronic company in + + align:start position:0% +company and it was electronic company in + + + align:start position:0% +company and it was electronic company in +Dallas. They came back a year later and + + align:start position:0% +Dallas. They came back a year later and + + + align:start position:0% +Dallas. They came back a year later and +wanted us to rebuild this corrugated box + + align:start position:0% +wanted us to rebuild this corrugated box + + + align:start position:0% +wanted us to rebuild this corrugated box +and it was about the length and width of + + align:start position:0% +and it was about the length and width of + + + align:start position:0% +and it was about the length and width of +this table about this deep. They had + + align:start position:0% +this table about this deep. They had + + + align:start position:0% +this table about this deep. They had +used it every week for a shipment to a + + align:start position:0% +used it every week for a shipment to a + + + align:start position:0% +used it every week for a shipment to a +plant and back for a year and then they + + align:start position:0% +plant and back for a year and then they + + + align:start position:0% +plant and back for a year and then they +asked them to rebuild it rather than a + + align:start position:0% +asked them to rebuild it rather than a + + + align:start position:0% +asked them to rebuild it rather than a +new one out of corrugated. Now, it was + + align:start position:0% +new one out of corrugated. Now, it was + + + align:start position:0% +new one out of corrugated. Now, it was +triple wall, but there is a good + + align:start position:0% +triple wall, but there is a good + + + align:start position:0% +triple wall, but there is a good +reusable. Fredo Lelay uses returnable uh + + align:start position:0% +reusable. Fredo Lelay uses returnable uh + + + align:start position:0% +reusable. Fredo Lelay uses returnable uh +corrugated boxes for all of their chips + + align:start position:0% +corrugated boxes for all of their chips + + + align:start position:0% +corrugated boxes for all of their chips +because they control the placement on + + align:start position:0% +because they control the placement on + + + align:start position:0% +because they control the placement on +the shelves and then they take the boxes + + align:start position:0% +the shelves and then they take the boxes + + + align:start position:0% +the shelves and then they take the boxes +back and they reuse them and they can + + align:start position:0% +back and they reuse them and they can + + + align:start position:0% +back and they reuse them and they can +reuse them for months at a time because + + align:start position:0% +reuse them for months at a time because + + + align:start position:0% +reuse them for months at a time because +they don't get beat up. Some good + + align:start position:0% +they don't get beat up. Some good + + + align:start position:0% +they don't get beat up. Some good +opportunities. Now, there's what we + + align:start position:0% +opportunities. Now, there's what we + + + align:start position:0% +opportunities. Now, there's what we +talked about. Reads stop drinking water. + + align:start position:0% +talked about. Reads stop drinking water. + + + align:start position:0% +talked about. Reads stop drinking water. +They'll continue to fail if it becomes + + align:start position:0% +They'll continue to fail if it becomes + + + align:start position:0% +They'll continue to fail if it becomes +saturated, but they resume failing if + + align:start position:0% +saturated, but they resume failing if + + + align:start position:0% +saturated, but they resume failing if +it's treated. And uh with that, + + align:start position:0% +it's treated. And uh with that, + + + align:start position:0% +it's treated. And uh with that, +I'm going to sit down and start + + align:start position:0% +I'm going to sit down and start + + + align:start position:0% +I'm going to sit down and start +drinking. And uh I'm going to turn this + + align:start position:0% +drinking. And uh I'm going to turn this + + + align:start position:0% +drinking. And uh I'm going to turn this +over to uh Dr. Aman from uh Florida. I + + align:start position:0% +over to uh Dr. Aman from uh Florida. I + + + align:start position:0% +over to uh Dr. Aman from uh Florida. I +appreciate your time and attention. + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +want everything. Yeah, + + align:start position:0% +want everything. Yeah, + + + align:start position:0% +want everything. Yeah, +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +I'm very sorry for some of you that were + + align:start position:0% +I'm very sorry for some of you that were + + + align:start position:0% +I'm very sorry for some of you that were +done with me yesterday. Um, I'm always + + align:start position:0% +done with me yesterday. Um, I'm always + + + align:start position:0% +done with me yesterday. Um, I'm always +back. It's like a bad cold. I was coming + + align:start position:0% +back. It's like a bad cold. I was coming + + + align:start position:0% +back. It's like a bad cold. I was coming +back. Um, I'm going to go fast because + + align:start position:0% +back. Um, I'm going to go fast because + + + align:start position:0% +back. Um, I'm going to go fast because +we have lunch and uh so uh I'm sorry I + + align:start position:0% +we have lunch and uh so uh I'm sorry I + + + align:start position:0% +we have lunch and uh so uh I'm sorry I +had bad uh finger on this thing. Okay. + + align:start position:0% +had bad uh finger on this thing. Okay. + + + align:start position:0% +had bad uh finger on this thing. Okay. +Well, thank you again and uh well I'm + + align:start position:0% +Well, thank you again and uh well I'm + + + align:start position:0% +Well, thank you again and uh well I'm +going to talk about packaging and a few + + align:start position:0% +going to talk about packaging and a few + + + align:start position:0% +going to talk about packaging and a few +of the thing that uh Rob discussed a + + align:start position:0% +of the thing that uh Rob discussed a + + + align:start position:0% +of the thing that uh Rob discussed a +little bit earlier is uh I'm going to + + align:start position:0% +little bit earlier is uh I'm going to + + + align:start position:0% +little bit earlier is uh I'm going to +address that and that's really + + align:start position:0% +address that and that's really + + + align:start position:0% +address that and that's really +interesting uh very quick you know it's + + align:start position:0% +interesting uh very quick you know it's + + + align:start position:0% +interesting uh very quick you know it's +um and I explained about the center for + + align:start position:0% +um and I explained about the center for + + + align:start position:0% +um and I explained about the center for +food retailing yesterday and uh we are + + align:start position:0% +food retailing yesterday and uh we are + + + align:start position:0% +food retailing yesterday and uh we are +trying to develop smart packaging for + + align:start position:0% +trying to develop smart packaging for + + + align:start position:0% +trying to develop smart packaging for +the food industry in the pharmaceutical + + align:start position:0% +the food industry in the pharmaceutical + + + align:start position:0% +the food industry in the pharmaceutical +industry and uh one thing that uh we + + align:start position:0% +industry and uh one thing that uh we + + + align:start position:0% +industry and uh one thing that uh we +started as well in this area of RFID + + align:start position:0% +started as well in this area of RFID + + + align:start position:0% +started as well in this area of RFID +this is what happened in 2003 when uh + + align:start position:0% +this is what happened in 2003 when uh + + + align:start position:0% +this is what happened in 2003 when uh +friendwell a company based in plan city + + align:start position:0% +friendwell a company based in plan city + + + align:start position:0% +friendwell a company based in plan city +Florida came to us and said we're going + + align:start position:0% +Florida came to us and said we're going + + + align:start position:0% +Florida came to us and said we're going +to give you RFID lab and start to play + + align:start position:0% +to give you RFID lab and start to play + + + align:start position:0% +to give you RFID lab and start to play +with this thing. And the reason why it + + align:start position:0% +with this thing. And the reason why it + + + align:start position:0% +with this thing. And the reason why it +was a good match for the food industry + + align:start position:0% +was a good match for the food industry + + + align:start position:0% +was a good match for the food industry +is because we have already + + align:start position:0% +is because we have already + + + align:start position:0% +is because we have already +infrastructure. We have 14 cold room uh + + align:start position:0% +infrastructure. We have 14 cold room uh + + + align:start position:0% +infrastructure. We have 14 cold room uh +temperature humidity programmable and we + + align:start position:0% +temperature humidity programmable and we + + + align:start position:0% +temperature humidity programmable and we +have two freezer, we have two C + + align:start position:0% +have two freezer, we have two C + + + align:start position:0% +have two freezer, we have two C +container, uh one refrigerated trailer + + align:start position:0% +container, uh one refrigerated trailer + + + align:start position:0% +container, uh one refrigerated trailer +and even a 727 frider uh that they don't + + align:start position:0% +and even a 727 frider uh that they don't + + + align:start position:0% +and even a 727 frider uh that they don't +allow me to fly luckily for everybody. + + align:start position:0% +allow me to fly luckily for everybody. + + + align:start position:0% +allow me to fly luckily for everybody. +But the the goal was to um from that + + align:start position:0% +But the the goal was to um from that + + + align:start position:0% +But the the goal was to um from that +time is that to to get the uh all the + + align:start position:0% +time is that to to get the uh all the + + + align:start position:0% +time is that to to get the uh all the +RFID hardware software manufacturer to + + align:start position:0% +RFID hardware software manufacturer to + + + align:start position:0% +RFID hardware software manufacturer to +have a start there and since then every + + align:start position:0% +have a start there and since then every + + + align:start position:0% +have a start there and since then every +three months they come and they upgrade + + align:start position:0% +three months they come and they upgrade + + + align:start position:0% +three months they come and they upgrade +our our equipment software hardware. So + + align:start position:0% +our our equipment software hardware. So + + + align:start position:0% +our our equipment software hardware. So +that's pretty neat for that. We always + + align:start position:0% +that's pretty neat for that. We always + + + align:start position:0% +that's pretty neat for that. We always +uh pretty get the uh the new stuff + + align:start position:0% +uh pretty get the uh the new stuff + + + align:start position:0% +uh pretty get the uh the new stuff +pretty ahead. So our lab is designed + + align:start position:0% +pretty ahead. So our lab is designed + + + align:start position:0% +pretty ahead. So our lab is designed +like Rob, you know, we have uh for + + align:start position:0% +like Rob, you know, we have uh for + + + align:start position:0% +like Rob, you know, we have uh for +everything to measure, you know, the + + align:start position:0% +everything to measure, you know, the + + + align:start position:0% +everything to measure, you know, the +impact of packaging and things like + + align:start position:0% +impact of packaging and things like + + + align:start position:0% +impact of packaging and things like +that. You see, Rob, I I use a drawing so + + align:start position:0% +that. You see, Rob, I I use a drawing so + + + align:start position:0% +that. You see, Rob, I I use a drawing so +I don't have to put the boards to uh + + align:start position:0% +I don't have to put the boards to uh + + + align:start position:0% +I don't have to put the boards to uh +hide my dirt in this thing. Okay. So, + + align:start position:0% +hide my dirt in this thing. Okay. So, + + + align:start position:0% +hide my dirt in this thing. Okay. So, +well, very quick, you know, uh the first + + align:start position:0% +well, very quick, you know, uh the first + + + align:start position:0% +well, very quick, you know, uh the first +thing that we did was with the TNA and + + align:start position:0% +thing that we did was with the TNA and + + + align:start position:0% +thing that we did was with the TNA and +the Fresh Express, you know, prepare + + align:start position:0% +the Fresh Express, you know, prepare + + + align:start position:0% +the Fresh Express, you know, prepare +salad and the head of lettuce and we did + + align:start position:0% +salad and the head of lettuce and we did + + + align:start position:0% +salad and the head of lettuce and we did +shipment from coast to coast, study the + + align:start position:0% +shipment from coast to coast, study the + + + align:start position:0% +shipment from coast to coast, study the +tag location on the speed of the load, + + align:start position:0% +tag location on the speed of the load, + + + align:start position:0% +tag location on the speed of the load, +and I'm going to go fast on that. The + + align:start position:0% +and I'm going to go fast on that. The + + + align:start position:0% +and I'm going to go fast on that. The +idea was to map a pallet and see where + + align:start position:0% +idea was to map a pallet and see where + + + align:start position:0% +idea was to map a pallet and see where +are the uh the good place to put a tag + + align:start position:0% +are the uh the good place to put a tag + + + align:start position:0% +are the uh the good place to put a tag +and the other place that were critical + + align:start position:0% +and the other place that were critical + + + align:start position:0% +and the other place that were critical +not put a tag because we couldn't read + + align:start position:0% +not put a tag because we couldn't read + + + align:start position:0% +not put a tag because we couldn't read +it because the effect of the old pallet. + + align:start position:0% +it because the effect of the old pallet. + + + align:start position:0% +it because the effect of the old pallet. +So we played for with that for a while + + align:start position:0% +So we played for with that for a while + + + align:start position:0% +So we played for with that for a while +until we decided that it was we have to + + align:start position:0% +until we decided that it was we have to + + + align:start position:0% +until we decided that it was we have to +go further with that. So we started to + + align:start position:0% +go further with that. So we started to + + + align:start position:0% +go further with that. So we started to +compare different material plastic wire + + align:start position:0% +compare different material plastic wire + + + align:start position:0% +compare different material plastic wire +bound wooden crate and uh and corrugated + + align:start position:0% +bound wooden crate and uh and corrugated + + + align:start position:0% +bound wooden crate and uh and corrugated +boxes and the I apologize for the wood + + align:start position:0% +boxes and the I apologize for the wood + + + align:start position:0% +boxes and the I apologize for the wood +crate. Uh I was still learning how to + + align:start position:0% +crate. Uh I was still learning how to + + + align:start position:0% +crate. Uh I was still learning how to +drive the uh Publix forklift and the + + align:start position:0% +drive the uh Publix forklift and the + + + align:start position:0% +drive the uh Publix forklift and the +corner were pretty uh stiff on this + + align:start position:0% +corner were pretty uh stiff on this + + + align:start position:0% +corner were pretty uh stiff on this +thing. But the idea was to compare what + + align:start position:0% +thing. But the idea was to compare what + + + align:start position:0% +thing. But the idea was to compare what +was the effect if you're using because + + align:start position:0% +was the effect if you're using because + + + align:start position:0% +was the effect if you're using because +these are coming from the same grower + + align:start position:0% +these are coming from the same grower + + + align:start position:0% +these are coming from the same grower +and they have different kind of + + align:start position:0% +and they have different kind of + + + align:start position:0% +and they have different kind of +packaging and things like that. So we + + align:start position:0% +packaging and things like that. So we + + + align:start position:0% +packaging and things like that. So we +wanted to study that and we came with a + + align:start position:0% +wanted to study that and we came with a + + + align:start position:0% +wanted to study that and we came with a +different thing but the problem that we + + align:start position:0% +different thing but the problem that we + + + align:start position:0% +different thing but the problem that we +dis we discover is that when people were + + align:start position:0% +dis we discover is that when people were + + + align:start position:0% +dis we discover is that when people were +looking for um readability read rate + + align:start position:0% +looking for um readability read rate + + + align:start position:0% +looking for um readability read rate +were having pretty low number and they + + align:start position:0% +were having pretty low number and they + + + align:start position:0% +were having pretty low number and they +were like oh man you know that's awful + + align:start position:0% +were like oh man you know that's awful + + + align:start position:0% +were like oh man you know that's awful +but I said well because we're losing the + + align:start position:0% +but I said well because we're losing the + + + align:start position:0% +but I said well because we're losing the +tag you know we cannot read them if + + align:start position:0% +tag you know we cannot read them if + + + align:start position:0% +tag you know we cannot read them if +they're not there anymore and uh we + + align:start position:0% +they're not there anymore and uh we + + + align:start position:0% +they're not there anymore and uh we +started to discover a lot of falling + + align:start position:0% +started to discover a lot of falling + + + align:start position:0% +started to discover a lot of falling +tags everywhere and that was a big issue + + align:start position:0% +tags everywhere and that was a big issue + + + align:start position:0% +tags everywhere and that was a big issue +one thing that we decided is that why we + + align:start position:0% +one thing that we decided is that why we + + + align:start position:0% +one thing that we decided is that why we +don't look a little bit further and and + + align:start position:0% +don't look a little bit further and and + + + align:start position:0% +don't look a little bit further and and +say when you pack something in a package + + align:start position:0% +say when you pack something in a package + + + align:start position:0% +say when you pack something in a package +uh it should stay you know with the + + align:start position:0% +uh it should stay you know with the + + + align:start position:0% +uh it should stay you know with the +package the RFID tag all the time at + + align:start position:0% +package the RFID tag all the time at + + + align:start position:0% +package the RFID tag all the time at +least identification and this is where + + align:start position:0% +least identification and this is where + + + align:start position:0% +least identification and this is where +it's started to trigger that we should + + align:start position:0% +it's started to trigger that we should + + + align:start position:0% +it's started to trigger that we should +always try to improve uh the way of of + + align:start position:0% +always try to improve uh the way of of + + + align:start position:0% +always try to improve uh the way of of +mixing tag RFID tag with packaging by + + align:start position:0% +mixing tag RFID tag with packaging by + + + align:start position:0% +mixing tag RFID tag with packaging by +trying to know if we cannot in the + + align:start position:0% +trying to know if we cannot in the + + + align:start position:0% +trying to know if we cannot in the +process of making the package just get + + align:start position:0% +process of making the package just get + + + align:start position:0% +process of making the package just get +the RFID tag inside and uh make it one + + align:start position:0% +the RFID tag inside and uh make it one + + + align:start position:0% +the RFID tag inside and uh make it one +step rather than many step so we started + + align:start position:0% +step rather than many step so we started + + + align:start position:0% +step rather than many step so we started +to investigate that so what we did is + + align:start position:0% +to investigate that so what we did is + + + align:start position:0% +to investigate that so what we did is +that we started to embed RFID tag + + align:start position:0% +that we started to embed RFID tag + + + align:start position:0% +that we started to embed RFID tag +reusable blessing container of course to + + align:start position:0% +reusable blessing container of course to + + + align:start position:0% +reusable blessing container of course to +reduce the use uh the cost per use. So + + align:start position:0% +reduce the use uh the cost per use. So + + + align:start position:0% +reduce the use uh the cost per use. So +this tag is there you cannot see it but + + align:start position:0% +this tag is there you cannot see it but + + + align:start position:0% +this tag is there you cannot see it but +it's there uh and that was doing with + + align:start position:0% +it's there uh and that was doing with + + + align:start position:0% +it's there uh and that was doing with +the PL injection molding plastic that we + + align:start position:0% +the PL injection molding plastic that we + + + align:start position:0% +the PL injection molding plastic that we +did that. So we can always track the + + align:start position:0% +did that. So we can always track the + + + align:start position:0% +did that. So we can always track the +base you know because the wall you can + + align:start position:0% +base you know because the wall you can + + + align:start position:0% +base you know because the wall you can +change them because you can if you break + + align:start position:0% +change them because you can if you break + + + align:start position:0% +change them because you can if you break +one wall you can change it but the base + + align:start position:0% +one wall you can change it but the base + + + align:start position:0% +one wall you can change it but the base +is always the base and uh so we can + + align:start position:0% +is always the base and uh so we can + + + align:start position:0% +is always the base and uh so we can +always track the life of these RPC + + align:start position:0% +always track the life of these RPC + + + align:start position:0% +always track the life of these RPC +because sometime they're used in + + align:start position:0% +because sometime they're used in + + + align:start position:0% +because sometime they're used in +different industry where you're trying + + align:start position:0% +different industry where you're trying + + + align:start position:0% +different industry where you're trying +to use them for different uh use and u + + align:start position:0% +to use them for different uh use and u + + + align:start position:0% +to use them for different uh use and u +so what we did we did we did during + + align:start position:0% +so what we did we did we did during + + + align:start position:0% +so what we did we did we did during +injection molding process and it cannot + + align:start position:0% +injection molding process and it cannot + + + align:start position:0% +injection molding process and it cannot +be removed but the the interesting is + + align:start position:0% +be removed but the the interesting is + + + align:start position:0% +be removed but the the interesting is +that we were always wondering when you + + align:start position:0% +that we were always wondering when you + + + align:start position:0% +that we were always wondering when you +inject plastic it's very high + + align:start position:0% +inject plastic it's very high + + + align:start position:0% +inject plastic it's very high +temperature and a lot of friction in the + + align:start position:0% +temperature and a lot of friction in the + + + align:start position:0% +temperature and a lot of friction in the +the mold and is a tag can survive that + + align:start position:0% +the mold and is a tag can survive that + + + align:start position:0% +the mold and is a tag can survive that +and can we locate the tag at the right + + align:start position:0% +and can we locate the tag at the right + + + align:start position:0% +and can we locate the tag at the right +place and it happened and you know it it + + align:start position:0% +place and it happened and you know it it + + + align:start position:0% +place and it happened and you know it it +was easier than we expected they were + + align:start position:0% +was easier than we expected they were + + + align:start position:0% +was easier than we expected they were +very tough and what is interesting is + + align:start position:0% +very tough and what is interesting is + + + align:start position:0% +very tough and what is interesting is +that I I can cut pretty much the price + + align:start position:0% +that I I can cut pretty much the price + + + align:start position:0% +that I I can cut pretty much the price +of that by uh skipping few steps so I + + align:start position:0% +of that by uh skipping few steps so I + + + align:start position:0% +of that by uh skipping few steps so I +don't need a fancy RFID tag in this + + align:start position:0% +don't need a fancy RFID tag in this + + + align:start position:0% +don't need a fancy RFID tag in this +thing you know I don't need very much in + + align:start position:0% +thing you know I don't need very much in + + + align:start position:0% +thing you know I don't need very much in +fact you know uh we're going to see + + align:start position:0% +fact you know uh we're going to see + + + align:start position:0% +fact you know uh we're going to see +later I only need the chips once in a + + align:start position:0% +later I only need the chips once in a + + + align:start position:0% +later I only need the chips once in a +while so the price of the old process is + + align:start position:0% +while so the price of the old process is + + + align:start position:0% +while so the price of the old process is +made and this thing doesn't require any + + align:start position:0% +made and this thing doesn't require any + + + align:start position:0% +made and this thing doesn't require any +new equipment for the injection molding + + align:start position:0% +new equipment for the injection molding + + + align:start position:0% +new equipment for the injection molding +company any company can do that. So what + + align:start position:0% +company any company can do that. So what + + + align:start position:0% +company any company can do that. So what +we did also is we started to embed on + + align:start position:0% +we did also is we started to embed on + + + align:start position:0% +we did also is we started to embed on +smaller container. It was more + + align:start position:0% +smaller container. It was more + + + align:start position:0% +smaller container. It was more +challenging because the thickness of the + + align:start position:0% +challenging because the thickness of the + + + align:start position:0% +challenging because the thickness of the +uh the chip is what is limit the the + + align:start position:0% +uh the chip is what is limit the the + + + align:start position:0% +uh the chip is what is limit the the +thickness of my wall but you can always + + align:start position:0% +thickness of my wall but you can always + + + align:start position:0% +thickness of my wall but you can always +find a place to put it. So as I said we + + align:start position:0% +find a place to put it. So as I said we + + + align:start position:0% +find a place to put it. So as I said we +don't need these fancy label we need a + + align:start position:0% +don't need these fancy label we need a + + + align:start position:0% +don't need these fancy label we need a +chip and that's it and everybody can do + + align:start position:0% +chip and that's it and everybody can do + + + align:start position:0% +chip and that's it and everybody can do +it. So that's pretty cheap at what + + align:start position:0% +it. So that's pretty cheap at what + + + align:start position:0% +it. So that's pretty cheap at what +point. Okay. So um injection bolding + + align:start position:0% +point. Okay. So um injection bolding + + + align:start position:0% +point. Okay. So um injection bolding +company can run a batch of regular + + align:start position:0% +company can run a batch of regular + + + align:start position:0% +company can run a batch of regular +container and just switch in a matter of + + align:start position:0% +container and just switch in a matter of + + + align:start position:0% +container and just switch in a matter of +few seconds to uh with one with embedded + + align:start position:0% +few seconds to uh with one with embedded + + + align:start position:0% +few seconds to uh with one with embedded +RFID tag and this is what we are doing + + align:start position:0% +RFID tag and this is what we are doing + + + align:start position:0% +RFID tag and this is what we are doing +right now. Of course you know + + align:start position:0% +right now. Of course you know + + + align:start position:0% +right now. Of course you know +everybody's like oh item level Jeep it's + + align:start position:0% +everybody's like oh item level Jeep it's + + + align:start position:0% +everybody's like oh item level Jeep it's +way too ahead you know but it just + + align:start position:0% +way too ahead you know but it just + + + align:start position:0% +way too ahead you know but it just +proved that you know I can take RFID tag + + align:start position:0% +proved that you know I can take RFID tag + + + align:start position:0% +proved that you know I can take RFID tag +container and put that in this container + + align:start position:0% +container and put that in this container + + + align:start position:0% +container and put that in this container +and drive the price to very very cheap + + align:start position:0% +and drive the price to very very cheap + + + align:start position:0% +and drive the price to very very cheap +to the price almost of the chips only. + + align:start position:0% +to the price almost of the chips only. + + + align:start position:0% +to the price almost of the chips only. +So that's very interesting on that. Well + + align:start position:0% +So that's very interesting on that. Well + + + align:start position:0% +So that's very interesting on that. Well +and also we started to uh do uh with + + align:start position:0% +and also we started to uh do uh with + + + align:start position:0% +and also we started to uh do uh with +project with different nature of product + + align:start position:0% +project with different nature of product + + + align:start position:0% +project with different nature of product +and of course you know because of the + + align:start position:0% +and of course you know because of the + + + align:start position:0% +and of course you know because of the +water and what we said uh one of the big + + align:start position:0% +water and what we said uh one of the big + + + align:start position:0% +water and what we said uh one of the big +issues that if I have my tag and with + + align:start position:0% +issues that if I have my tag and with + + + align:start position:0% +issues that if I have my tag and with +water I cannot read it. So we sometime + + align:start position:0% +water I cannot read it. So we sometime + + + align:start position:0% +water I cannot read it. So we sometime +we have to redesign the package not very + + align:start position:0% +we have to redesign the package not very + + + align:start position:0% +we have to redesign the package not very +much but slight change that I can + + align:start position:0% +much but slight change that I can + + + align:start position:0% +much but slight change that I can +position my RFID tag to a location that + + align:start position:0% +position my RFID tag to a location that + + + align:start position:0% +position my RFID tag to a location that +it will not interfere with the been + + align:start position:0% +it will not interfere with the been + + + align:start position:0% +it will not interfere with the been +interfere by the the food that I put + + align:start position:0% +interfere by the the food that I put + + + align:start position:0% +interfere by the the food that I put +inside. So we were able to pinpoint + + align:start position:0% +inside. So we were able to pinpoint + + + align:start position:0% +inside. So we were able to pinpoint +location and redesign slightly some of + + align:start position:0% +location and redesign slightly some of + + + align:start position:0% +location and redesign slightly some of +these container and and get these good + + align:start position:0% +these container and and get these good + + + align:start position:0% +these container and and get these good +read. In fact, and I'm going to tell you + + align:start position:0% +read. In fact, and I'm going to tell you + + + align:start position:0% +read. In fact, and I'm going to tell you +something interesting. We did a thousand + + align:start position:0% +something interesting. We did a thousand + + + align:start position:0% +something interesting. We did a thousand +uh container with uh tags embedded and + + align:start position:0% +uh container with uh tags embedded and + + + align:start position:0% +uh container with uh tags embedded and +only one of them fail. All of them were + + align:start position:0% +only one of them fail. All of them were + + + align:start position:0% +only one of them fail. All of them were +good. So that was pretty interesting on + + align:start position:0% +good. So that was pretty interesting on + + + align:start position:0% +good. So that was pretty interesting on +that. What we are doing also in 2000 + + align:start position:0% +that. What we are doing also in 2000 + + + align:start position:0% +that. What we are doing also in 2000 +right now is that we are looking for + + align:start position:0% +right now is that we are looking for + + + align:start position:0% +right now is that we are looking for +smaller antenna design. We don't some of + + align:start position:0% +smaller antenna design. We don't some of + + + align:start position:0% +smaller antenna design. We don't some of +them we just want to reach six to 12 + + align:start position:0% +them we just want to reach six to 12 + + + align:start position:0% +them we just want to reach six to 12 +inches. So, we're going to need some + + align:start position:0% +inches. So, we're going to need some + + + align:start position:0% +inches. So, we're going to need some +help on the design, antenna design on + + align:start position:0% +help on the design, antenna design on + + + align:start position:0% +help on the design, antenna design on +this thing. So, I'm just uh asking you + + align:start position:0% +this thing. So, I'm just uh asking you + + + align:start position:0% +this thing. So, I'm just uh asking you +everybody, you know, help. Okay. On the + + align:start position:0% +everybody, you know, help. Okay. On the + + + align:start position:0% +everybody, you know, help. Okay. On the +firm industry, well, this is something + + align:start position:0% +firm industry, well, this is something + + + align:start position:0% +firm industry, well, this is something +interesting because um your container if + + align:start position:0% +interesting because um your container if + + + align:start position:0% +interesting because um your container if +you put pills in it and you want to + + align:start position:0% +you put pills in it and you want to + + + align:start position:0% +you put pills in it and you want to +follow that, I can remove a label. Okay? + + align:start position:0% +follow that, I can remove a label. Okay? + + + align:start position:0% +follow that, I can remove a label. Okay? +But if it's inside the container, I + + align:start position:0% +But if it's inside the container, I + + + align:start position:0% +But if it's inside the container, I +cannot remove the label. It's inside the + + align:start position:0% +cannot remove the label. It's inside the + + + align:start position:0% +cannot remove the label. It's inside the +container. I can stack up with the tons + + align:start position:0% +container. I can stack up with the tons + + + align:start position:0% +container. I can stack up with the tons +of label. Well, it's still part of the + + align:start position:0% +of label. Well, it's still part of the + + + align:start position:0% +of label. Well, it's still part of the +container. And we did that and so of the + + align:start position:0% +container. And we did that and so of the + + + align:start position:0% +container. And we did that and so of the +thing is that prescription drug using + + align:start position:0% +thing is that prescription drug using + + + align:start position:0% +thing is that prescription drug using +blow mold and count container uh has + + align:start position:0% +blow mold and count container uh has + + + align:start position:0% +blow mold and count container uh has +been something that we're working in + + align:start position:0% +been something that we're working in + + + align:start position:0% +been something that we're working in +pretty close to the to be successful on + + align:start position:0% +pretty close to the to be successful on + + + align:start position:0% +pretty close to the to be successful on +this one and also we work on the blood + + align:start position:0% +this one and also we work on the blood + + + align:start position:0% +this one and also we work on the blood +product right now and packaging + + align:start position:0% +product right now and packaging + + + align:start position:0% +product right now and packaging +component that you put in the when you + + align:start position:0% +component that you put in the when you + + + align:start position:0% +component that you put in the when you +ship + + align:start position:0% +ship + + + align:start position:0% +ship +perform product on this thing. That was + + align:start position:0% +perform product on this thing. That was + + + align:start position:0% +perform product on this thing. That was +a fast uh presentation but I'm going to + + align:start position:0% +a fast uh presentation but I'm going to + + + align:start position:0% +a fast uh presentation but I'm going to +let you after that just doing that. Hey + + align:start position:0% +let you after that just doing that. Hey + + + align:start position:0% +let you after that just doing that. Hey +we are uh we are there we are working + + align:start position:0% +we are uh we are there we are working + + + align:start position:0% +we are uh we are there we are working +very much but we need some collaboration + + align:start position:0% +very much but we need some collaboration + + + align:start position:0% +very much but we need some collaboration +also. So, thank you very much. + + align:start position:0% + + + + align:start position:0% + +Was it fast? + + align:start position:0% + + + + align:start position:0% + +Okay. Thank you. I'm going to Well, I + + align:start position:0% +Okay. Thank you. I'm going to Well, I + + + align:start position:0% +Okay. Thank you. I'm going to Well, I +can + + align:start position:0% +can + + + align:start position:0% +can +Well, + + align:start position:0% +Well, + + + align:start position:0% +Well, +we'll do the Laurel Hardy thing. + + align:start position:0% +we'll do the Laurel Hardy thing. + + + align:start position:0% +we'll do the Laurel Hardy thing. +John Pierre and I were talking. We're + + align:start position:0% +John Pierre and I were talking. We're + + + align:start position:0% +John Pierre and I were talking. We're +going to have a race. See who could do + + align:start position:0% +going to have a race. See who could do + + + align:start position:0% +going to have a race. See who could do +their presentation the fastest. So, I'm + + align:start position:0% +their presentation the fastest. So, I'm + + + align:start position:0% +their presentation the fastest. So, I'm +going to win on this one. But, all + + align:start position:0% +going to win on this one. But, all + + + align:start position:0% +going to win on this one. But, all +right. I'm first going to tell you guys + + align:start position:0% +right. I'm first going to tell you guys + + + align:start position:0% +right. I'm first going to tell you guys +who we are and why you should care. + + align:start position:0% +who we are and why you should care. + + + align:start position:0% +who we are and why you should care. +Then, I'm going to tell you about what + + align:start position:0% +Then, I'm going to tell you about what + + + align:start position:0% +Then, I'm going to tell you about what +we're looking for out there as far as + + align:start position:0% +we're looking for out there as far as + + + align:start position:0% +we're looking for out there as far as +technology and why we want that. So, + + align:start position:0% +technology and why we want that. So, + + + align:start position:0% +technology and why we want that. So, +we'll flip through. Um, we're once I + + align:start position:0% +we'll flip through. Um, we're once I + + + align:start position:0% +we'll flip through. Um, we're once I +figure out how to work this Midwest + + align:start position:0% +figure out how to work this Midwest + + + align:start position:0% +figure out how to work this Midwest +Feco. We're into consumer packaging. Um, + + align:start position:0% +Feco. We're into consumer packaging. Um, + + + align:start position:0% +Feco. We're into consumer packaging. Um, +we're into three principal areas. And if + + align:start position:0% +we're into three principal areas. And if + + + align:start position:0% +we're into three principal areas. And if +you look at these three principal areas + + align:start position:0% +you look at these three principal areas + + + align:start position:0% +you look at these three principal areas +and you think about RFID and ubiquitous + + align:start position:0% +and you think about RFID and ubiquitous + + + align:start position:0% +and you think about RFID and ubiquitous +tagging, these are are three areas where + + align:start position:0% +tagging, these are are three areas where + + + align:start position:0% +tagging, these are are three areas where +they're prime candidates for RFID. The + + align:start position:0% +they're prime candidates for RFID. The + + + align:start position:0% +they're prime candidates for RFID. The +media and entertainment. Here you have + + align:start position:0% +media and entertainment. Here you have + + + align:start position:0% +media and entertainment. Here you have +these high value items in small + + align:start position:0% +these high value items in small + + + align:start position:0% +these high value items in small +packages. You're ending up with high + + align:start position:0% +packages. You're ending up with high + + + align:start position:0% +packages. You're ending up with high +shrinkage. you have the um the area + + align:start position:0% +shrinkage. you have the um the area + + + align:start position:0% +shrinkage. you have the um the area +where an out of stock is a big issue + + align:start position:0% +where an out of stock is a big issue + + + align:start position:0% +where an out of stock is a big issue +because if somebody walks in there and + + align:start position:0% +because if somebody walks in there and + + + align:start position:0% +because if somebody walks in there and +they don't find the title they want, + + align:start position:0% +they don't find the title they want, + + + align:start position:0% +they don't find the title they want, +they're not going to buy some other + + align:start position:0% +they're not going to buy some other + + + align:start position:0% +they're not going to buy some other +title. They're going to go to some other + + align:start position:0% +title. They're going to go to some other + + + align:start position:0% +title. They're going to go to some other +store with all the money in their pocket + + align:start position:0% +store with all the money in their pocket + + + align:start position:0% +store with all the money in their pocket +and they're going to buy everything else + + align:start position:0% +and they're going to buy everything else + + + align:start position:0% +and they're going to buy everything else +they needed at that other store. Also, + + align:start position:0% +they needed at that other store. Also, + + + align:start position:0% +they needed at that other store. Also, +we're into the consumer products. We um + + align:start position:0% +we're into the consumer products. We um + + + align:start position:0% +we're into the consumer products. We um +heard about Simply uh white earlier on + + align:start position:0% +heard about Simply uh white earlier on + + + align:start position:0% +heard about Simply uh white earlier on +here. That's uh another you know + + align:start position:0% +here. That's uh another you know + + + align:start position:0% +here. That's uh another you know +interesting thing for tracking and out + + align:start position:0% +interesting thing for tracking and out + + + align:start position:0% +interesting thing for tracking and out +of stocks. And then we have the healthc + + align:start position:0% +of stocks. And then we have the healthc + + + align:start position:0% +of stocks. And then we have the healthc +care industry where you have the the + + align:start position:0% +care industry where you have the the + + + align:start position:0% +care industry where you have the the +huge issue of counterfeits. The FDA's um + + align:start position:0% +huge issue of counterfeits. The FDA's um + + + align:start position:0% +huge issue of counterfeits. The FDA's um +edict that has come down that basically + + align:start position:0% +edict that has come down that basically + + + align:start position:0% +edict that has come down that basically +strongly suggests uh RFID in the um in + + align:start position:0% +strongly suggests uh RFID in the um in + + + align:start position:0% +strongly suggests uh RFID in the um in +the packaging there. + + align:start position:0% +the packaging there. + + + align:start position:0% +the packaging there. +The other um area that you're probably + + align:start position:0% +The other um area that you're probably + + + align:start position:0% +The other um area that you're probably +more familiar with, ME West, or at least + + align:start position:0% +more familiar with, ME West, or at least + + + align:start position:0% +more familiar with, ME West, or at least +the MEED name, is in the consumer and + + align:start position:0% +the MEED name, is in the consumer and + + + align:start position:0% +the MEED name, is in the consumer and +office products area. And we're into + + align:start position:0% +office products area. And we're into + + + align:start position:0% +office products area. And we're into +RFID in that area thanks to Walmart. Uh + + align:start position:0% +RFID in that area thanks to Walmart. Uh + + + align:start position:0% +RFID in that area thanks to Walmart. Uh +we're at the uh pallet level in shipping + + align:start position:0% +we're at the uh pallet level in shipping + + + align:start position:0% +we're at the uh pallet level in shipping +our our goods on that uh in that product + + align:start position:0% +our our goods on that uh in that product + + + align:start position:0% +our our goods on that uh in that product +line. Now our um we've been in looking + + align:start position:0% +line. Now our um we've been in looking + + + align:start position:0% +line. Now our um we've been in looking +at RFID participating in this area for + + align:start position:0% +at RFID participating in this area for + + + align:start position:0% +at RFID participating in this area for +um about six years now. We were um one + + align:start position:0% +um about six years now. We were um one + + + align:start position:0% +um about six years now. We were um one +of the early members of the AutoID + + align:start position:0% +of the early members of the AutoID + + + align:start position:0% +of the early members of the AutoID +center up here at MIT. We also founded a + + align:start position:0% +center up here at MIT. We also founded a + + + align:start position:0% +center up here at MIT. We also founded a +um a group in our company called + + align:start position:0% +um a group in our company called + + + align:start position:0% +um a group in our company called +Intelligence Systems and I'm not sure if + + align:start position:0% +Intelligence Systems and I'm not sure if + + + align:start position:0% +Intelligence Systems and I'm not sure if +any of you had um read about them. They + + align:start position:0% +any of you had um read about them. They + + + align:start position:0% +any of you had um read about them. They +were in the news for uh quite some time + + align:start position:0% +were in the news for uh quite some time + + + align:start position:0% +were in the news for uh quite some time +now here. Basically that uh that group + + align:start position:0% +now here. Basically that uh that group + + + align:start position:0% +now here. Basically that uh that group +came up with a um an intelligent shelf + + align:start position:0% +came up with a um an intelligent shelf + + + align:start position:0% +came up with a um an intelligent shelf +system where uh unlike some of the other + + align:start position:0% +system where uh unlike some of the other + + + align:start position:0% +system where uh unlike some of the other +ones that were out there where people + + align:start position:0% +ones that were out there where people + + + align:start position:0% +ones that were out there where people +had sent multiple wires to each of the + + align:start position:0% +had sent multiple wires to each of the + + + align:start position:0% +had sent multiple wires to each of the +antennas trying to reduce the cost, we + + align:start position:0% +antennas trying to reduce the cost, we + + + align:start position:0% +antennas trying to reduce the cost, we +found a way of taking one reader and + + align:start position:0% +found a way of taking one reader and + + + align:start position:0% +found a way of taking one reader and +basically using that reader to read a + + align:start position:0% +basically using that reader to read a + + + align:start position:0% +basically using that reader to read a +100 antennas and having a single wire + + align:start position:0% +100 antennas and having a single wire + + + align:start position:0% +100 antennas and having a single wire +running down the line of a 100 antennas + + align:start position:0% +running down the line of a 100 antennas + + + align:start position:0% +running down the line of a 100 antennas +and uh bringing + + align:start position:0% +and uh bringing + + + align:start position:0% +and uh bringing +it back. Um, this as you can think about + + align:start position:0% +it back. Um, this as you can think about + + + align:start position:0% +it back. Um, this as you can think about +this is a really unique way of reducing + + align:start position:0% +this is a really unique way of reducing + + + align:start position:0% +this is a really unique way of reducing +the cost of the infrastructure by + + align:start position:0% +the cost of the infrastructure by + + + align:start position:0% +the cost of the infrastructure by +several orders of magnitude. And that + + align:start position:0% +several orders of magnitude. And that + + + align:start position:0% +several orders of magnitude. And that +was essentially our goal here as we got + + align:start position:0% +was essentially our goal here as we got + + + align:start position:0% +was essentially our goal here as we got +into this. We had we had looked at the + + align:start position:0% +into this. We had we had looked at the + + + align:start position:0% +into this. We had we had looked at the +field and realized that for tags to be + + align:start position:0% +field and realized that for tags to be + + + align:start position:0% +field and realized that for tags to be +ubiquitous, the tags were going to have + + align:start position:0% +ubiquitous, the tags were going to have + + + align:start position:0% +ubiquitous, the tags were going to have +to be commodity type items. And there + + align:start position:0% +to be commodity type items. And there + + + align:start position:0% +to be commodity type items. And there +were plenty of players out there like + + align:start position:0% +were plenty of players out there like + + + align:start position:0% +were plenty of players out there like +Alien. We were in discussions with them + + align:start position:0% +Alien. We were in discussions with them + + + align:start position:0% +Alien. We were in discussions with them +who were doing a very good job of that. + + align:start position:0% +who were doing a very good job of that. + + + align:start position:0% +who were doing a very good job of that. +But people weren't really addressing the + + align:start position:0% +But people weren't really addressing the + + + align:start position:0% +But people weren't really addressing the +infrastructure successfully. So um now + + align:start position:0% +infrastructure successfully. So um now + + + align:start position:0% +infrastructure successfully. So um now +this last year we uh sold the + + align:start position:0% +this last year we uh sold the + + + align:start position:0% +this last year we uh sold the +intelligence systems or most of the + + align:start position:0% +intelligence systems or most of the + + + align:start position:0% +intelligence systems or most of the +intelligence systems to an outside group + + align:start position:0% +intelligence systems to an outside group + + + align:start position:0% +intelligence systems to an outside group +so that they could um really concentrate + + align:start position:0% +so that they could um really concentrate + + + align:start position:0% +so that they could um really concentrate +on it uh full force. We still have a + + align:start position:0% +on it uh full force. We still have a + + + align:start position:0% +on it uh full force. We still have a +residual interest and are following it + + align:start position:0% +residual interest and are following it + + + align:start position:0% +residual interest and are following it +because we do think that that it's very + + align:start position:0% +because we do think that that it's very + + + align:start position:0% +because we do think that that it's very +important for success in this uh in this + + align:start position:0% +important for success in this uh in this + + + align:start position:0% +important for success in this uh in this +field for that company to be successful. + + align:start position:0% +field for that company to be successful. + + + align:start position:0% +field for that company to be successful. +our capabilities at this point in time. + + align:start position:0% +our capabilities at this point in time. + + + align:start position:0% +our capabilities at this point in time. +We do have production capabilities for + + align:start position:0% +We do have production capabilities for + + + align:start position:0% +We do have production capabilities for +uh doing um item level coding of tags of + + align:start position:0% +uh doing um item level coding of tags of + + + align:start position:0% +uh doing um item level coding of tags of +uh testing those tags in line and uh + + align:start position:0% +uh testing those tags in line and uh + + + align:start position:0% +uh testing those tags in line and uh +tagging boxes. Uh we have not seen the + + align:start position:0% +tagging boxes. Uh we have not seen the + + + align:start position:0% +tagging boxes. Uh we have not seen the +the pull from the customer base, but + + align:start position:0% +the pull from the customer base, but + + + align:start position:0% +the pull from the customer base, but +we're positioned and we're trying to um + + align:start position:0% +we're positioned and we're trying to um + + + align:start position:0% +we're positioned and we're trying to um +improve that position daily so that + + align:start position:0% +improve that position daily so that + + + align:start position:0% +improve that position daily so that +we're ready when the the market pull + + align:start position:0% +we're ready when the the market pull + + + align:start position:0% +we're ready when the the market pull +comes along. Uh that's basically our + + align:start position:0% +comes along. Uh that's basically our + + + align:start position:0% +comes along. Uh that's basically our +ability to tag is anything we can put an + + align:start position:0% +ability to tag is anything we can put an + + + align:start position:0% +ability to tag is anything we can put an +EAS tag on today we can uh switch over + + align:start position:0% +EAS tag on today we can uh switch over + + + align:start position:0% +EAS tag on today we can uh switch over +and do an RFID tag. Now, uh what we need + + align:start position:0% +and do an RFID tag. Now, uh what we need + + + align:start position:0% +and do an RFID tag. Now, uh what we need +as far as technology, we're looking for + + align:start position:0% +as far as technology, we're looking for + + + align:start position:0% +as far as technology, we're looking for +the things that are going to make our + + align:start position:0% +the things that are going to make our + + + align:start position:0% +the things that are going to make our +our customers successful and um probably + + align:start position:0% +our customers successful and um probably + + + align:start position:0% +our customers successful and um probably +the primary thing there would be item + + align:start position:0% +the primary thing there would be item + + + align:start position:0% +the primary thing there would be item +level tracking at low cost. And we've + + align:start position:0% +level tracking at low cost. And we've + + + align:start position:0% +level tracking at low cost. And we've +been hearing uh discussions uh yesterday + + align:start position:0% +been hearing uh discussions uh yesterday + + + align:start position:0% +been hearing uh discussions uh yesterday +and today on some of the things that + + align:start position:0% +and today on some of the things that + + + align:start position:0% +and today on some of the things that +would um go into reducing the cost of + + align:start position:0% +would um go into reducing the cost of + + + align:start position:0% +would um go into reducing the cost of +the tag and such. But uh also want to + + align:start position:0% +the tag and such. But uh also want to + + + align:start position:0% +the tag and such. But uh also want to +remind everyone that this doesn't + + align:start position:0% +remind everyone that this doesn't + + + align:start position:0% +remind everyone that this doesn't +necessarily mean 96bit RFID. There's a + + align:start position:0% +necessarily mean 96bit RFID. There's a + + + align:start position:0% +necessarily mean 96bit RFID. There's a +lot of attention out there to chipless + + align:start position:0% +lot of attention out there to chipless + + + align:start position:0% +lot of attention out there to chipless +tags to um organic RFID. Uh and these + + align:start position:0% +tags to um organic RFID. Uh and these + + + align:start position:0% +tags to um organic RFID. Uh and these +are areas that we're we're exploring and + + align:start position:0% +are areas that we're we're exploring and + + + align:start position:0% +are areas that we're we're exploring and +and discussions with various companies + + align:start position:0% +and discussions with various companies + + + align:start position:0% +and discussions with various companies +on. But uh if you are going forward + + align:start position:0% +on. But uh if you are going forward + + + align:start position:0% +on. But uh if you are going forward +looking into the field, one of the + + align:start position:0% +looking into the field, one of the + + + align:start position:0% +looking into the field, one of the +things that I want to caution everyone + + align:start position:0% +things that I want to caution everyone + + + align:start position:0% +things that I want to caution everyone +on is that uh these things cannot sit + + align:start position:0% +on is that uh these things cannot sit + + + align:start position:0% +on is that uh these things cannot sit +there and expect to come in and require + + align:start position:0% +there and expect to come in and require + + + align:start position:0% +there and expect to come in and require +a whole new infrastructure through the + + align:start position:0% +a whole new infrastructure through the + + + align:start position:0% +a whole new infrastructure through the +whole supply chain. I mean the the 96 + + align:start position:0% +whole supply chain. I mean the the 96 + + + align:start position:0% +whole supply chain. I mean the the 96 +bit is a juggernaut going down that road + + align:start position:0% +bit is a juggernaut going down that road + + + align:start position:0% +bit is a juggernaut going down that road +there. we're going to see those that + + align:start position:0% +there. we're going to see those that + + + align:start position:0% +there. we're going to see those that +infrastructure go in there. If the or + + align:start position:0% +infrastructure go in there. If the or + + + align:start position:0% +infrastructure go in there. If the or +the organic RFID can only read at 125 um + + align:start position:0% +the organic RFID can only read at 125 um + + + align:start position:0% +the organic RFID can only read at 125 um +K megahertz or hertz, then um and you + + align:start position:0% +K megahertz or hertz, then um and you + + + align:start position:0% +K megahertz or hertz, then um and you +don't have an agile reader that can read + + align:start position:0% +don't have an agile reader that can read + + + align:start position:0% +don't have an agile reader that can read +at both points, you're going to have a + + align:start position:0% +at both points, you're going to have a + + + align:start position:0% +at both points, you're going to have a +hard time selling those that organic + + align:start position:0% +hard time selling those that organic + + + align:start position:0% +hard time selling those that organic +RFID in there. The same with the uh the + + align:start position:0% +RFID in there. The same with the uh the + + + align:start position:0% +RFID in there. The same with the uh the +chipless tags. Uh if you've looked at + + align:start position:0% +chipless tags. Uh if you've looked at + + + align:start position:0% +chipless tags. Uh if you've looked at +the chip various chipless technologies, + + align:start position:0% +the chip various chipless technologies, + + + align:start position:0% +the chip various chipless technologies, +it's very interesting. That's very + + align:start position:0% +it's very interesting. That's very + + + align:start position:0% +it's very interesting. That's very +appealing to us because our desire is to + + align:start position:0% +appealing to us because our desire is to + + + align:start position:0% +appealing to us because our desire is to +be able to just print the RFID on there. + + align:start position:0% +be able to just print the RFID on there. + + + align:start position:0% +be able to just print the RFID on there. +That's the way we're going to reduce it + + align:start position:0% +That's the way we're going to reduce it + + + align:start position:0% +That's the way we're going to reduce it +down the cost down for our customers. + + align:start position:0% +down the cost down for our customers. + + + align:start position:0% +down the cost down for our customers. +But uh again, what are you looking at + + align:start position:0% +But uh again, what are you looking at + + + align:start position:0% +But uh again, what are you looking at +when you get a chipless tag? You're + + align:start position:0% +when you get a chipless tag? You're + + + align:start position:0% +when you get a chipless tag? You're +probably not looking at 96 bits and + + align:start position:0% +probably not looking at 96 bits and + + + align:start position:0% +probably not looking at 96 bits and +you're definitely not looking at the + + align:start position:0% +you're definitely not looking at the + + + align:start position:0% +you're definitely not looking at the +same reader that you're using for using + + align:start position:0% +same reader that you're using for using + + + align:start position:0% +same reader that you're using for using +uh for reading your silicon based tag. + + align:start position:0% +uh for reading your silicon based tag. + + + align:start position:0% +uh for reading your silicon based tag. +Now there are value propositions out + + align:start position:0% +Now there are value propositions out + + + align:start position:0% +Now there are value propositions out +there that would would draw towards + + align:start position:0% +there that would would draw towards + + + align:start position:0% +there that would would draw towards +things these uh technologies. If you can + + align:start position:0% +things these uh technologies. If you can + + + align:start position:0% +things these uh technologies. If you can +if you can identify the niche market + + align:start position:0% +if you can identify the niche market + + + align:start position:0% +if you can identify the niche market +that you're going after um we have + + align:start position:0% +that you're going after um we have + + + align:start position:0% +that you're going after um we have +something to talk about. + + align:start position:0% + + + + align:start position:0% + +All right. The other thing is uh we have + + align:start position:0% +All right. The other thing is uh we have + + + align:start position:0% +All right. The other thing is uh we have +to look at the total cost of the tag + + align:start position:0% +to look at the total cost of the tag + + + align:start position:0% +to look at the total cost of the tag +over the lifetime. It's not just the + + align:start position:0% +over the lifetime. It's not just the + + + align:start position:0% +over the lifetime. It's not just the +cost of the chip and I think we've heard + + align:start position:0% +cost of the chip and I think we've heard + + + align:start position:0% +cost of the chip and I think we've heard +that before. What's the cost of how how + + align:start position:0% +that before. What's the cost of how how + + + align:start position:0% +that before. What's the cost of how how +much does it cost to actually put it on + + align:start position:0% +much does it cost to actually put it on + + + align:start position:0% +much does it cost to actually put it on +the package? What's the antenna cost? + + align:start position:0% +the package? What's the antenna cost? + + + align:start position:0% +the package? What's the antenna cost? +What's the crossover uh cost there? Um + + align:start position:0% +What's the crossover uh cost there? Um + + + align:start position:0% +What's the crossover uh cost there? Um +what's going to happen um as far as + + align:start position:0% +what's going to happen um as far as + + + align:start position:0% +what's going to happen um as far as +testing? How do you handle the rejects? + + align:start position:0% +testing? How do you handle the rejects? + + + align:start position:0% +testing? How do you handle the rejects? +Uh when you get failed reads in the + + align:start position:0% +Uh when you get failed reads in the + + + align:start position:0% +Uh when you get failed reads in the +supply chain, how are you going to + + align:start position:0% +supply chain, how are you going to + + + align:start position:0% +supply chain, how are you going to +handle those? Those represent costs. Uh + + align:start position:0% +handle those? Those represent costs. Uh + + + align:start position:0% +handle those? Those represent costs. Uh +and then finally, and we've heard that + + align:start position:0% +and then finally, and we've heard that + + + align:start position:0% +and then finally, and we've heard that +alerted to before, uh this disposal + + align:start position:0% +alerted to before, uh this disposal + + + align:start position:0% +alerted to before, uh this disposal +issue is going to come and catch up to + + align:start position:0% +issue is going to come and catch up to + + + align:start position:0% +issue is going to come and catch up to +us at some point in time here. What is + + align:start position:0% +us at some point in time here. What is + + + align:start position:0% +us at some point in time here. What is +in your antenna? Um, + + align:start position:0% +in your antenna? Um, + + + align:start position:0% +in your antenna? Um, +look at Europe. Look at there's places + + align:start position:0% +look at Europe. Look at there's places + + + align:start position:0% +look at Europe. Look at there's places +in New England that are starting to look + + align:start position:0% +in New England that are starting to look + + + align:start position:0% +in New England that are starting to look +at the uh metals in the in the + + align:start position:0% +at the uh metals in the in the + + + align:start position:0% +at the uh metals in the in the +landfills. + + align:start position:0% +landfills. + + + align:start position:0% +landfills. +And then the last area is one that's + + align:start position:0% +And then the last area is one that's + + + align:start position:0% +And then the last area is one that's +gotten a lot of attention here and I'm + + align:start position:0% +gotten a lot of attention here and I'm + + + align:start position:0% +gotten a lot of attention here and I'm +glad to see it. And that's in the uh the + + align:start position:0% +glad to see it. And that's in the uh the + + + align:start position:0% +glad to see it. And that's in the uh the +whole area of track and trace. Track and + + align:start position:0% +whole area of track and trace. Track and + + + align:start position:0% +whole area of track and trace. Track and +trace is a very very um valuable um + + align:start position:0% +trace is a very very um valuable um + + + align:start position:0% +trace is a very very um valuable um +thing to look at especially when we're + + align:start position:0% +thing to look at especially when we're + + + align:start position:0% +thing to look at especially when we're +looking at the uh pharmaceutical + + align:start position:0% +looking at the uh pharmaceutical + + + align:start position:0% +looking at the uh pharmaceutical +industries. But what's what's going to + + align:start position:0% +industries. But what's what's going to + + + align:start position:0% +industries. But what's what's going to +be out there in the data data management + + align:start position:0% +be out there in the data data management + + + align:start position:0% +be out there in the data data management +infrastructure? Uh who's going to come + + align:start position:0% +infrastructure? Uh who's going to come + + + align:start position:0% +infrastructure? Uh who's going to come +up with that? How are we going to handle + + align:start position:0% +up with that? How are we going to handle + + + align:start position:0% +up with that? How are we going to handle +this data? Uh pass it from um various + + align:start position:0% +this data? Uh pass it from um various + + + align:start position:0% +this data? Uh pass it from um various +entities in the supply chain. + + align:start position:0% +entities in the supply chain. + + + align:start position:0% +entities in the supply chain. +That's it. I beat John Pierre. + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +I guess we're going to run this + + align:start position:0% +I guess we're going to run this + + + align:start position:0% +I guess we're going to run this +ourselves. So, if you have any + + align:start position:0% +ourselves. So, if you have any + + + align:start position:0% +ourselves. So, if you have any +questions, come on down. We Sorry, we + + align:start position:0% +questions, come on down. We Sorry, we + + + align:start position:0% +questions, come on down. We Sorry, we +felt like Miles Davis there with our + + align:start position:0% +felt like Miles Davis there with our + + + align:start position:0% +felt like Miles Davis there with our +back to the audience, but uh we wanted + + align:start position:0% +back to the audience, but uh we wanted + + + align:start position:0% +back to the audience, but uh we wanted +to learn something new at the same time + + align:start position:0% +to learn something new at the same time + + + align:start position:0% +to learn something new at the same time +and it's hard to do it that way. So, + + align:start position:0% +and it's hard to do it that way. So, + + + align:start position:0% +and it's hard to do it that way. So, +excuse us. It hurts. Yeah. Okay. Just + + align:start position:0% +excuse us. It hurts. Yeah. Okay. Just + + + align:start position:0% +excuse us. It hurts. Yeah. Okay. Just +one question again for what changes are + + align:start position:0% +one question again for what changes are + + + align:start position:0% +one question again for what changes are +you seeing to the metrics + + align:start position:0% +you seeing to the metrics + + + align:start position:0% +you seeing to the metrics +as you experiment with this technology + + align:start position:0% +as you experiment with this technology + + + align:start position:0% +as you experiment with this technology +in your packaging design? What do you + + align:start position:0% +in your packaging design? What do you + + + align:start position:0% +in your packaging design? What do you +measure measure performances that may be + + align:start position:0% +measure measure performances that may be + + + align:start position:0% +measure measure performances that may be +changing units that you measure may be + + align:start position:0% +changing units that you measure may be + + + align:start position:0% +changing units that you measure may be +changing? What have you experienced with + + align:start position:0% +changing? What have you experienced with + + + align:start position:0% +changing? What have you experienced with +all your testing or what you might see + + align:start position:0% +all your testing or what you might see + + + align:start position:0% +all your testing or what you might see +in the future? + + align:start position:0% +in the future? + + + align:start position:0% +in the future? +Um, I'm not sure this is the same + + align:start position:0% +Um, I'm not sure this is the same + + + align:start position:0% +Um, I'm not sure this is the same +answer, but uh I don't see much new at + + align:start position:0% +answer, but uh I don't see much new at + + + align:start position:0% +answer, but uh I don't see much new at +all, honestly. Um, + + align:start position:0% +all, honestly. Um, + + + align:start position:0% +all, honestly. Um, +units are the same that I used in my + + align:start position:0% +units are the same that I used in my + + + align:start position:0% +units are the same that I used in my +graduate work uh studying random + + align:start position:0% +graduate work uh studying random + + + align:start position:0% +graduate work uh studying random +vibration as an energy source. Um, + + align:start position:0% +vibration as an energy source. Um, + + + align:start position:0% +vibration as an energy source. Um, +RF is a great area and I'm I'm not here + + align:start position:0% +RF is a great area and I'm I'm not here + + + align:start position:0% +RF is a great area and I'm I'm not here +to uh disavow it in any way, + + align:start position:0% +to uh disavow it in any way, + + + align:start position:0% +to uh disavow it in any way, +but it's a technology. It's not a + + align:start position:0% +but it's a technology. It's not a + + + align:start position:0% +but it's a technology. It's not a +panacea. Uh I, you know, with all due + + align:start position:0% +panacea. Uh I, you know, with all due + + + align:start position:0% +panacea. Uh I, you know, with all due +deference to uh previous speakers, I + + align:start position:0% +deference to uh previous speakers, I + + + align:start position:0% +deference to uh previous speakers, I +don't think it's worthy of a discipline. + + align:start position:0% +don't think it's worthy of a discipline. + + + align:start position:0% +don't think it's worthy of a discipline. +Uh I did, uh get caught short here + + align:start position:0% +Uh I did, uh get caught short here + + + align:start position:0% +Uh I did, uh get caught short here +briefly by asking the uh gentleman from + + align:start position:0% +briefly by asking the uh gentleman from + + + align:start position:0% +briefly by asking the uh gentleman from +IBM if they still had barcode + + align:start position:0% +IBM if they still had barcode + + + align:start position:0% +IBM if they still had barcode +specialists on staff and he said, "Yes, + + align:start position:0% +specialists on staff and he said, "Yes, + + + align:start position:0% +specialists on staff and he said, "Yes, +we do." Although he might not have been + + align:start position:0% +we do." Although he might not have been + + + align:start position:0% +we do." Although he might not have been +sure what they did, but I know in + + align:start position:0% +sure what they did, but I know in + + + align:start position:0% +sure what they did, but I know in +Michigan we've gotten rid of barcode + + align:start position:0% +Michigan we've gotten rid of barcode + + + align:start position:0% +Michigan we've gotten rid of barcode +specialists. And you know uh one of my + + align:start position:0% +specialists. And you know uh one of my + + + align:start position:0% +specialists. And you know uh one of my +grad students is working with uh uh + + align:start position:0% +grad students is working with uh uh + + + align:start position:0% +grad students is working with uh uh +Simon Langford at Walmart running their + + align:start position:0% +Simon Langford at Walmart running their + + + align:start position:0% +Simon Langford at Walmart running their +lab. And uh when he was hired uh the + + align:start position:0% +lab. And uh when he was hired uh the + + + align:start position:0% +lab. And uh when he was hired uh the +comment Simon made was that we hope in 3 + + align:start position:0% +comment Simon made was that we hope in 3 + + + align:start position:0% +comment Simon made was that we hope in 3 +years you don't have a job because the + + align:start position:0% +years you don't have a job because the + + + align:start position:0% +years you don't have a job because the +intent was to make this so broadly based + + align:start position:0% +intent was to make this so broadly based + + + align:start position:0% +intent was to make this so broadly based +across the company that it becomes as + + align:start position:0% +across the company that it becomes as + + + align:start position:0% +across the company that it becomes as +common as UPC and you don't need + + align:start position:0% +common as UPC and you don't need + + + align:start position:0% +common as UPC and you don't need +anything special. It's just an adaptive + + align:start position:0% +anything special. It's just an adaptive + + + align:start position:0% +anything special. It's just an adaptive +technology that helps. + + align:start position:0% +technology that helps. + + + align:start position:0% +technology that helps. +Thank you. + + align:start position:0% +Thank you. + + + align:start position:0% +Thank you. +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +Hi uh Patrick Mone from Georgetown + + align:start position:0% +Hi uh Patrick Mone from Georgetown + + + align:start position:0% +Hi uh Patrick Mone from Georgetown +University and want to thank you guys + + align:start position:0% +University and want to thank you guys + + + align:start position:0% +University and want to thank you guys +first for this presentation. I think it + + align:start position:0% +first for this presentation. I think it + + + align:start position:0% +first for this presentation. I think it +outlined a lot of the shortcomings in + + align:start position:0% +outlined a lot of the shortcomings in + + + align:start position:0% +outlined a lot of the shortcomings in +this technology. I sat in on uh + + align:start position:0% +this technology. I sat in on uh + + + align:start position:0% +this technology. I sat in on uh +opportunities opportunities. Yes, + + align:start position:0% +opportunities opportunities. Yes, + + + align:start position:0% +opportunities opportunities. Yes, +absolutely. And I've sat in on on + + align:start position:0% +absolutely. And I've sat in on on + + + align:start position:0% +absolutely. And I've sat in on on +several government meetings on uh + + align:start position:0% +several government meetings on uh + + + align:start position:0% +several government meetings on uh +launching uh RFID for identity + + align:start position:0% +launching uh RFID for identity + + + align:start position:0% +launching uh RFID for identity +management. And the shortcomings that + + align:start position:0% +management. And the shortcomings that + + + align:start position:0% +management. And the shortcomings that +I'm seeing time and time again are the + + align:start position:0% +I'm seeing time and time again are the + + + align:start position:0% +I'm seeing time and time again are the +lack of understanding from I don't want + + align:start position:0% +lack of understanding from I don't want + + + align:start position:0% +lack of understanding from I don't want +to name names but these consulting + + align:start position:0% +to name names but these consulting + + + align:start position:0% +to name names but these consulting +companies that kind of promise RF + + align:start position:0% +companies that kind of promise RF + + + align:start position:0% +companies that kind of promise RF +fighting in a box and passive allowing + + align:start position:0% +fighting in a box and passive allowing + + + align:start position:0% +fighting in a box and passive allowing +you to drive through at 55 miles an hour + + align:start position:0% +you to drive through at 55 miles an hour + + + align:start position:0% +you to drive through at 55 miles an hour +and things like that and it's just not + + align:start position:0% +and things like that and it's just not + + + align:start position:0% +and things like that and it's just not +being answered. So I think research like + + align:start position:0% +being answered. So I think research like + + + align:start position:0% +being answered. So I think research like +this would be very advantageous uh to be + + align:start position:0% +this would be very advantageous uh to be + + + align:start position:0% +this would be very advantageous uh to be +out there in the public for the + + align:start position:0% +out there in the public for the + + + align:start position:0% +out there in the public for the +industry. My question is on + + align:start position:0% +industry. My question is on + + + align:start position:0% +industry. My question is on +pharmaceutical. Uh the FDA has asked to + + align:start position:0% +pharmaceutical. Uh the FDA has asked to + + + align:start position:0% +pharmaceutical. Uh the FDA has asked to +secure around counterfeiting that + + align:start position:0% +secure around counterfeiting that + + + align:start position:0% +secure around counterfeiting that +there's overt, covert, and forensic. And + + align:start position:0% +there's overt, covert, and forensic. And + + + align:start position:0% +there's overt, covert, and forensic. And +in the launches that are out there now, + + align:start position:0% +in the launches that are out there now, + + + align:start position:0% +in the launches that are out there now, +you're seeing overt and covert. You're + + align:start position:0% +you're seeing overt and covert. You're + + + align:start position:0% +you're seeing overt and covert. You're +not seeing forensic. And I'm and I'm + + align:start position:0% +not seeing forensic. And I'm and I'm + + + align:start position:0% +not seeing forensic. And I'm and I'm +curious if anyone can uh answer that. + + align:start position:0% +curious if anyone can uh answer that. + + + align:start position:0% +curious if anyone can uh answer that. +And then my last is a potential wag of + + align:start position:0% +And then my last is a potential wag of + + + align:start position:0% +And then my last is a potential wag of +the finger. I hope none of you are + + align:start position:0% +the finger. I hope none of you are + + + align:start position:0% +the finger. I hope none of you are +responsible for those damn huge plastic + + align:start position:0% +responsible for those damn huge plastic + + + align:start position:0% +responsible for those damn huge plastic +containers for my small microchip that + + align:start position:0% +containers for my small microchip that + + + align:start position:0% +containers for my small microchip that +are frustratingly impossible to open. So + + align:start position:0% +are frustratingly impossible to open. So + + + align:start position:0% +are frustratingly impossible to open. So +that uh thanks again. + + align:start position:0% + + + + align:start position:0% + +Um + + align:start position:0% + + + + align:start position:0% + +I don't have a really good answer I + + align:start position:0% +I don't have a really good answer I + + + align:start position:0% +I don't have a really good answer I +guess on the uh uh forensic. Um, we have + + align:start position:0% +guess on the uh uh forensic. Um, we have + + + align:start position:0% +guess on the uh uh forensic. Um, we have +done work with both overt and covert and + + align:start position:0% +done work with both overt and covert and + + + align:start position:0% +done work with both overt and covert and +uh there are much better experts than uh + + align:start position:0% +uh there are much better experts than uh + + + align:start position:0% +uh there are much better experts than uh +at least the three of us on that. It's + + align:start position:0% +at least the three of us on that. It's + + + align:start position:0% +at least the three of us on that. It's +kind of interesting if you guys, you + + align:start position:0% +kind of interesting if you guys, you + + + align:start position:0% +kind of interesting if you guys, you +know, pull out a $100 bill and just pass + + align:start position:0% +know, pull out a $100 bill and just pass + + + align:start position:0% +know, pull out a $100 bill and just pass +them forward. I'll show you how they + + align:start position:0% +them forward. I'll show you how they + + + align:start position:0% +them forward. I'll show you how they +have all of these security or + + align:start position:0% +have all of these security or + + + align:start position:0% +have all of these security or +anti-counterfeiting + + align:start position:0% +anti-counterfeiting + + + align:start position:0% +anti-counterfeiting +uh techniques involved. And for those of + + align:start position:0% +uh techniques involved. And for those of + + + align:start position:0% +uh techniques involved. And for those of +you visiting from different countries, + + align:start position:0% +you visiting from different countries, + + + align:start position:0% +you visiting from different countries, +our our currency now has 20 uh overt uh + + align:start position:0% +our our currency now has 20 uh overt uh + + + align:start position:0% +our our currency now has 20 uh overt uh +or covert anti-counterfeiting + + align:start position:0% +or covert anti-counterfeiting + + + align:start position:0% +or covert anti-counterfeiting +uh detection devices built into it and + + align:start position:0% +uh detection devices built into it and + + + align:start position:0% +uh detection devices built into it and +at least 10 others that they won't talk + + align:start position:0% +at least 10 others that they won't talk + + + align:start position:0% +at least 10 others that they won't talk +about. Uh but there's roughly 30 + + align:start position:0% +about. Uh but there's roughly 30 + + + align:start position:0% +about. Uh but there's roughly 30 +anti-counterfeiting features in in an + + align:start position:0% +anti-counterfeiting features in in an + + + align:start position:0% +anti-counterfeiting features in in an +individual bill. And those are the + + align:start position:0% +individual bill. And those are the + + + align:start position:0% +individual bill. And those are the +people you really need to uh bring into + + align:start position:0% +people you really need to uh bring into + + + align:start position:0% +people you really need to uh bring into +this discussion because I'm certainly + + align:start position:0% +this discussion because I'm certainly + + + align:start position:0% +this discussion because I'm certainly +not a specialist in that. All right. + + align:start position:0% +not a specialist in that. All right. + + + align:start position:0% +not a specialist in that. All right. +to answer that. Like to answer that, but + + align:start position:0% +to answer that. Like to answer that, but + + + align:start position:0% +to answer that. Like to answer that, but +we're on it. Uh we can't tell you what + + align:start position:0% +we're on it. Uh we can't tell you what + + + align:start position:0% +we're on it. Uh we can't tell you what +we're doing, but uh we're on it. We have + + align:start position:0% +we're doing, but uh we're on it. We have + + + align:start position:0% +we're doing, but uh we're on it. We have +those three areas covered. Excellent. + + align:start position:0% +those three areas covered. Excellent. + + + align:start position:0% +those three areas covered. Excellent. +Very quick. You know, the uh also on the + + align:start position:0% +Very quick. You know, the uh also on the + + + align:start position:0% +Very quick. You know, the uh also on the +other area that we never discussed is + + align:start position:0% +other area that we never discussed is + + + align:start position:0% +other area that we never discussed is +temporary evidence, you know, and um + + align:start position:0% +temporary evidence, you know, and um + + + align:start position:0% +temporary evidence, you know, and um +have you seen that sometime you have + + align:start position:0% +have you seen that sometime you have + + + align:start position:0% +have you seen that sometime you have +something a plastic it said if it's not + + align:start position:0% +something a plastic it said if it's not + + + align:start position:0% +something a plastic it said if it's not +there don't use it, but if it's not + + align:start position:0% +there don't use it, but if it's not + + + align:start position:0% +there don't use it, but if it's not +there, you cannot read it anymore. Okay. + + align:start position:0% +there, you cannot read it anymore. Okay. + + + align:start position:0% +there, you cannot read it anymore. Okay. +And uh so that we were discussing and + + align:start position:0% +And uh so that we were discussing and + + + align:start position:0% +And uh so that we were discussing and +the best protection for temporary vision + + align:start position:0% +the best protection for temporary vision + + + align:start position:0% +the best protection for temporary vision +is that nobody can see it and this is + + align:start position:0% +is that nobody can see it and this is + + + align:start position:0% +is that nobody can see it and this is +what we're working on. + + align:start position:0% +what we're working on. + + + align:start position:0% +what we're working on. +Thank you. Good presentation. Thank you. + + align:start position:0% +Thank you. Good presentation. Thank you. + + + align:start position:0% +Thank you. Good presentation. Thank you. +Yeah, John Hitchford from Mars. My + + align:start position:0% +Yeah, John Hitchford from Mars. My + + + align:start position:0% +Yeah, John Hitchford from Mars. My +question is how is RFID starting to work + + align:start position:0% +question is how is RFID starting to work + + + align:start position:0% +question is how is RFID starting to work +its way into the curriculum particularly + + align:start position:0% +its way into the curriculum particularly + + + align:start position:0% +its way into the curriculum particularly +undergraduate because it's important + + align:start position:0% +undergraduate because it's important + + + align:start position:0% +undergraduate because it's important +that they know and also how are you + + align:start position:0% +that they know and also how are you + + + align:start position:0% +that they know and also how are you +training the guys that aren't in school + + align:start position:0% +training the guys that aren't in school + + + align:start position:0% +training the guys that aren't in school +anymore about the utilization of + + align:start position:0% +anymore about the utilization of + + + align:start position:0% +anymore about the utilization of +technology in a supplier base? I'd be + + align:start position:0% +technology in a supplier base? I'd be + + + align:start position:0% +technology in a supplier base? I'd be +interested in that question. + + align:start position:0% +interested in that question. + + + align:start position:0% +interested in that question. +um from a Michigan State standpoint at + + align:start position:0% +um from a Michigan State standpoint at + + + align:start position:0% +um from a Michigan State standpoint at +least um I started teaching a class on + + align:start position:0% +least um I started teaching a class on + + + align:start position:0% +least um I started teaching a class on +RFID and packaging two years ago and uh + + align:start position:0% +RFID and packaging two years ago and uh + + + align:start position:0% +RFID and packaging two years ago and uh +it's been uh an elective class but I've + + align:start position:0% +it's been uh an elective class but I've + + + align:start position:0% +it's been uh an elective class but I've +had really good uh turnouts not only + + align:start position:0% +had really good uh turnouts not only + + + align:start position:0% +had really good uh turnouts not only +from packaging but uh from uh uh + + align:start position:0% +from packaging but uh from uh uh + + + align:start position:0% +from packaging but uh from uh uh +engineering from uh supply chain + + align:start position:0% +engineering from uh supply chain + + + align:start position:0% +engineering from uh supply chain +management logistics um and because all + + align:start position:0% +management logistics um and because all + + + align:start position:0% +management logistics um and because all +of these cross over these areas and we + + align:start position:0% +of these cross over these areas and we + + + align:start position:0% +of these cross over these areas and we +now have um uh companies coming in to + + align:start position:0% +now have um uh companies coming in to + + + align:start position:0% +now have um uh companies coming in to +hire our undergraduates and even our + + align:start position:0% +hire our undergraduates and even our + + + align:start position:0% +hire our undergraduates and even our +graduate students that will not even + + align:start position:0% +graduate students that will not even + + + align:start position:0% +graduate students that will not even +interview them if they haven't had the + + align:start position:0% +interview them if they haven't had the + + + align:start position:0% +interview them if they haven't had the +class because this is an area that + + align:start position:0% +class because this is an area that + + + align:start position:0% +class because this is an area that +companies are trying to find those + + align:start position:0% +companies are trying to find those + + + align:start position:0% +companies are trying to find those +answers and they're trying to find + + align:start position:0% +answers and they're trying to find + + + align:start position:0% +answers and they're trying to find +people that have hands-on + + align:start position:0% +people that have hands-on + + + align:start position:0% +people that have hands-on +work and and feel so that they come in + + align:start position:0% +work and and feel so that they come in + + + align:start position:0% +work and and feel so that they come in +hitting the ground running uh as opposed + + align:start position:0% +hitting the ground running uh as opposed + + + align:start position:0% +hitting the ground running uh as opposed +to having to be trained. Uh there are + + align:start position:0% +to having to be trained. Uh there are + + + align:start position:0% +to having to be trained. Uh there are +also just like yourself uh conferences + + align:start position:0% +also just like yourself uh conferences + + + align:start position:0% +also just like yourself uh conferences +up the wazoo. Um, you know, JP and I + + align:start position:0% +up the wazoo. Um, you know, JP and I + + + align:start position:0% +up the wazoo. Um, you know, JP and I +have talked uh repeatedly about we could + + align:start position:0% +have talked uh repeatedly about we could + + + align:start position:0% +have talked uh repeatedly about we could +be at a conference every week of the + + align:start position:0% +be at a conference every week of the + + + align:start position:0% +be at a conference every week of the +year and uh if you could get more of + + align:start position:0% +year and uh if you could get more of + + + align:start position:0% +year and uh if you could get more of +them in Hawaii, we might. Um, but uh + + align:start position:0% +them in Hawaii, we might. Um, but uh + + + align:start position:0% +them in Hawaii, we might. Um, but uh +that's really what you're almost limited + + align:start position:0% +that's really what you're almost limited + + + align:start position:0% +that's really what you're almost limited +to. But we are developing an uh online + + align:start position:0% +to. But we are developing an uh online + + + align:start position:0% +to. But we are developing an uh online +uh web-based program for uh uh recent + + align:start position:0% +uh web-based program for uh uh recent + + + align:start position:0% +uh web-based program for uh uh recent +graduates like yourself. + + align:start position:0% +graduates like yourself. + + + align:start position:0% +graduates like yourself. +Yeah. very quick and univers + + align:start position:0% + + + + align:start position:0% + +almost every courses where you can have + + align:start position:0% +almost every courses where you can have + + + align:start position:0% +almost every courses where you can have +RFID topic in it are is already there. + + align:start position:0% +RFID topic in it are is already there. + + + align:start position:0% +RFID topic in it are is already there. +So we have chapter in transportation + + align:start position:0% +So we have chapter in transportation + + + align:start position:0% +So we have chapter in transportation +distribution food uh packaging we have + + align:start position:0% +distribution food uh packaging we have + + + align:start position:0% +distribution food uh packaging we have +uh consumer product all these packaging + + align:start position:0% +uh consumer product all these packaging + + + align:start position:0% +uh consumer product all these packaging +courses we they all have chapter where + + align:start position:0% +courses we they all have chapter where + + + align:start position:0% +courses we they all have chapter where +it's suitable to to put it inside + + align:start position:0% +it's suitable to to put it inside + + + align:start position:0% +it's suitable to to put it inside +and uh well basically we've been talking + + align:start position:0% +and uh well basically we've been talking + + + align:start position:0% +and uh well basically we've been talking +to our senior management about it for + + align:start position:0% +to our senior management about it for + + + align:start position:0% +to our senior management about it for +probably six years now and um I think + + align:start position:0% +probably six years now and um I think + + + align:start position:0% +probably six years now and um I think +they get it now um we're way past the uh + + align:start position:0% +they get it now um we're way past the uh + + + align:start position:0% +they get it now um we're way past the uh +the early days when people thought RFID + + align:start position:0% +the early days when people thought RFID + + + align:start position:0% +the early days when people thought RFID +meant you'd read them from satellites. + + align:start position:0% +meant you'd read them from satellites. + + + align:start position:0% +meant you'd read them from satellites. +Um, I think if you if you cornered + + align:start position:0% +Um, I think if you if you cornered + + + align:start position:0% +Um, I think if you if you cornered +anyone in our senior management team, + + align:start position:0% +anyone in our senior management team, + + + align:start position:0% +anyone in our senior management team, +you'd have a pretty good conversation. + + align:start position:0% + + + + align:start position:0% + +Last question. Hi, my name is James Shed + + align:start position:0% +Last question. Hi, my name is James Shed + + + align:start position:0% +Last question. Hi, my name is James Shed +Dubage from Gillette PNG. Um, + + align:start position:0% +Dubage from Gillette PNG. Um, + + + align:start position:0% +Dubage from Gillette PNG. Um, +as part of EPC Global, there's a strong + + align:start position:0% +as part of EPC Global, there's a strong + + + align:start position:0% +as part of EPC Global, there's a strong +effort to try and standardize on + + align:start position:0% +effort to try and standardize on + + + align:start position:0% +effort to try and standardize on +measures and metrics and like you + + align:start position:0% +measures and metrics and like you + + + align:start position:0% +measures and metrics and like you +mentioned, John Anduro and both Jeff + + align:start position:0% +mentioned, John Anduro and both Jeff + + + align:start position:0% +mentioned, John Anduro and both Jeff +Talazar are co-chairs. I'm on I'm the + + align:start position:0% +Talazar are co-chairs. I'm on I'm the + + + align:start position:0% +Talazar are co-chairs. I'm on I'm the +third co-chair of that group. Uh we'd + + align:start position:0% +third co-chair of that group. Uh we'd + + + align:start position:0% +third co-chair of that group. Uh we'd +like to get more academic involvement + + align:start position:0% +like to get more academic involvement + + + align:start position:0% +like to get more academic involvement +into that group. How do how do we make + + align:start position:0% +into that group. How do how do we make + + + align:start position:0% +into that group. How do how do we make +that happen so that you're not going off + + align:start position:0% +that happen so that you're not going off + + + align:start position:0% +that happen so that you're not going off +and doing these tests that are very + + align:start position:0% +and doing these tests that are very + + + align:start position:0% +and doing these tests that are very +interesting, but if we can try and + + align:start position:0% +interesting, but if we can try and + + + align:start position:0% +interesting, but if we can try and +synergize on those, I'd like to hear + + align:start position:0% +synergize on those, I'd like to hear + + + align:start position:0% +synergize on those, I'd like to hear +your thoughts on that. Great issue. I + + align:start position:0% +your thoughts on that. Great issue. I + + + align:start position:0% +your thoughts on that. Great issue. I +actually had a conversation with uh some + + align:start position:0% +actually had a conversation with uh some + + + align:start position:0% +actually had a conversation with uh some +people from EPC Global yesterday to uh + + align:start position:0% +people from EPC Global yesterday to uh + + + align:start position:0% +people from EPC Global yesterday to uh +try and uh synthesize some of the work + + align:start position:0% +try and uh synthesize some of the work + + + align:start position:0% +try and uh synthesize some of the work +we're doing. I'm a uh uh co-chair + + align:start position:0% +we're doing. I'm a uh uh co-chair + + + align:start position:0% +we're doing. I'm a uh uh co-chair +actually a chair of a new task group + + align:start position:0% +actually a chair of a new task group + + + align:start position:0% +actually a chair of a new task group +within uh ASM the American Society of + + align:start position:0% +within uh ASM the American Society of + + + align:start position:0% +within uh ASM the American Society of +Testing and Materials uh where we are uh + + align:start position:0% +Testing and Materials uh where we are uh + + + align:start position:0% +Testing and Materials uh where we are uh +developing procedures and reporting on + + align:start position:0% +developing procedures and reporting on + + + align:start position:0% +developing procedures and reporting on +how you test case loads, pallet loads, + + align:start position:0% +how you test case loads, pallet loads, + + + align:start position:0% +how you test case loads, pallet loads, +uh military applications, pharmaceutical + + align:start position:0% +uh military applications, pharmaceutical + + + align:start position:0% +uh military applications, pharmaceutical +applications, etc. Um, we want to work + + align:start position:0% +applications, etc. Um, we want to work + + + align:start position:0% +applications, etc. Um, we want to work +in conjunction with you on developing + + align:start position:0% +in conjunction with you on developing + + + align:start position:0% +in conjunction with you on developing +these and and share all the data uh + + align:start position:0% +these and and share all the data uh + + + align:start position:0% +these and and share all the data uh +where we're different from EPC because + + align:start position:0% +where we're different from EPC because + + + align:start position:0% +where we're different from EPC because +that always comes up is that we are uh + + align:start position:0% +that always comes up is that we are uh + + + align:start position:0% +that always comes up is that we are uh +uh reader tag frequency agnostic. We + + align:start position:0% +uh reader tag frequency agnostic. We + + + align:start position:0% +uh reader tag frequency agnostic. We +don't care what you use. Here is a + + align:start position:0% +don't care what you use. Here is a + + + align:start position:0% +don't care what you use. Here is a +standard procedure for measuring + + align:start position:0% +standard procedure for measuring + + + align:start position:0% +standard procedure for measuring +readability + + align:start position:0% +readability + + + align:start position:0% +readability +of a case, readability of an item, read + + align:start position:0% +of a case, readability of an item, read + + + align:start position:0% +of a case, readability of an item, read +distance, read fields, uh, military, + + align:start position:0% +distance, read fields, uh, military, + + + align:start position:0% +distance, read fields, uh, military, +whatever it is. And so if it's if it + + align:start position:0% +whatever it is. And so if it's if it + + + align:start position:0% +whatever it is. And so if it's if it +fits into EPC through 1356, 915, they + + align:start position:0% +fits into EPC through 1356, 915, they + + + align:start position:0% +fits into EPC through 1356, 915, they +might be identical, but if you have a + + align:start position:0% +might be identical, but if you have a + + + align:start position:0% +might be identical, but if you have a +closed loop system and are looking at at + + align:start position:0% +closed loop system and are looking at at + + + align:start position:0% +closed loop system and are looking at at +134 or 2.4, 5.8, 8 uh and even different + + align:start position:0% +134 or 2.4, 5.8, 8 uh and even different + + + align:start position:0% +134 or 2.4, 5.8, 8 uh and even different +frequencies from that. Uh there's so + + align:start position:0% +frequencies from that. Uh there's so + + + align:start position:0% +frequencies from that. Uh there's so +much in military at 433 right now that + + align:start position:0% +much in military at 433 right now that + + + align:start position:0% +much in military at 433 right now that +um we just want to set up what that is + + align:start position:0% +um we just want to set up what that is + + + align:start position:0% +um we just want to set up what that is +and if anybody contacts me I'll be happy + + align:start position:0% +and if anybody contacts me I'll be happy + + + align:start position:0% +and if anybody contacts me I'll be happy +to respond. + + align:start position:0% +to respond. + + + align:start position:0% +to respond. +Maybe I can say something about it um + + align:start position:0% +Maybe I can say something about it um + + + align:start position:0% +Maybe I can say something about it um +about APC and u the standardization. + + align:start position:0% +about APC and u the standardization. + + + align:start position:0% +about APC and u the standardization. +I would say that in our lab you know we + + align:start position:0% +I would say that in our lab you know we + + + align:start position:0% +I would say that in our lab you know we +touch many many area some of them will + + align:start position:0% +touch many many area some of them will + + + align:start position:0% +touch many many area some of them will +fall under APC what you're looking for + + align:start position:0% +fall under APC what you're looking for + + + align:start position:0% +fall under APC what you're looking for +and uh that's going to be good but we + + align:start position:0% +and uh that's going to be good but we + + + align:start position:0% +and uh that's going to be good but we +still going to keep doing other area + + align:start position:0% +still going to keep doing other area + + + align:start position:0% +still going to keep doing other area +because the request of other application + + align:start position:0% +because the request of other application + + + align:start position:0% +because the request of other application +is pretty big and so if some of the + + align:start position:0% +is pretty big and so if some of the + + + align:start position:0% +is pretty big and so if some of the +thing that we do will fall under APC + + align:start position:0% +thing that we do will fall under APC + + + align:start position:0% +thing that we do will fall under APC +what you're looking for this is great + + align:start position:0% +what you're looking for this is great + + + align:start position:0% +what you're looking for this is great +okay but we still going to have a lot of + + align:start position:0% +okay but we still going to have a lot of + + + align:start position:0% +okay but we still going to have a lot of +thing that we want to keep uh running + + align:start position:0% +thing that we want to keep uh running + + + align:start position:0% +thing that we want to keep uh running +also + + align:start position:0% +also + + + align:start position:0% +also +thank you if we could on that note thank \ No newline at end of file diff --git a/wwQu2_u8jeo.txt b/wwQu2_u8jeo.txt new file mode 100644 index 0000000000000000000000000000000000000000..cd95571054adcba46db267f2f49fd9171a05a5c5 --- /dev/null +++ b/wwQu2_u8jeo.txt @@ -0,0 +1,243 @@ +align:start position:0% + +so during the semester we have a few + + align:start position:0% +so during the semester we have a few + + + align:start position:0% +so during the semester we have a few +recitation instructors they help with + + align:start position:0% +recitation instructors they help with + + + align:start position:0% +recitation instructors they help with +the students during the recitation + + align:start position:0% +the students during the recitation + + + align:start position:0% +the students during the recitation +section so during those sections your + + align:start position:0% +section so during those sections your + + + align:start position:0% +section so during those sections your +the the instructor will solve a similar + + align:start position:0% +the the instructor will solve a similar + + + align:start position:0% +the the instructor will solve a similar +problem like what is actually covered + + align:start position:0% +problem like what is actually covered + + + align:start position:0% +problem like what is actually covered +during the same during the lecture and + + align:start position:0% +during the same during the lecture and + + + align:start position:0% +during the same during the lecture and +that give the students another chance to + + align:start position:0% +that give the students another chance to + + + align:start position:0% +that give the students another chance to +look at more example and to get for + + align:start position:0% +look at more example and to get for + + + align:start position:0% +look at more example and to get for +media will get used to the calculation + + align:start position:0% +media will get used to the calculation + + + align:start position:0% +media will get used to the calculation +which we carry how for the first time + + align:start position:0% +which we carry how for the first time + + + align:start position:0% +which we carry how for the first time +during the the lecture so also the + + align:start position:0% +during the the lecture so also the + + + align:start position:0% +during the the lecture so also the +recitation section and during the + + align:start position:0% +recitation section and during the + + + align:start position:0% +recitation section and during the +recitation section the instructors help + + align:start position:0% +recitation section the instructors help + + + align:start position:0% +recitation section the instructors help +the students they can actually ask more + + align:start position:0% +the students they can actually ask more + + + align:start position:0% +the students they can actually ask more +questions during the recitation sections + + align:start position:0% +questions during the recitation sections + + + align:start position:0% +questions during the recitation sections +including the questions they have the + + align:start position:0% +including the questions they have the + + + align:start position:0% +including the questions they have the +pset or any additional questions they + + align:start position:0% +pset or any additional questions they + + + align:start position:0% +pset or any additional questions they +they thought about after the lecture ok + + align:start position:0% +they thought about after the lecture ok + + + align:start position:0% +they thought about after the lecture ok +so that they get some chance another + + align:start position:0% +so that they get some chance another + + + align:start position:0% +so that they get some chance another +chance to clear some of the concept + + align:start position:0% +chance to clear some of the concept + + + align:start position:0% +chance to clear some of the concept +which they don't really understand + + align:start position:0% +which they don't really understand + + + align:start position:0% +which they don't really understand +during the during the lecture so we did + + align:start position:0% +during the during the lecture so we did + + + align:start position:0% +during the during the lecture so we did +not record the recitation sections + + align:start position:0% +not record the recitation sections + + + align:start position:0% +not record the recitation sections +during the fall semester in 2016 on the + + align:start position:0% +during the fall semester in 2016 on the + + + align:start position:0% +during the fall semester in 2016 on the +other hand we included problem-solving + + align:start position:0% +other hand we included problem-solving + + + align:start position:0% +other hand we included problem-solving +videos from Professor with Busha which + + align:start position:0% +videos from Professor with Busha which + + + align:start position:0% +videos from Professor with Busha which +is similar to what we do during the + + align:start position:0% +is similar to what we do during the + + + align:start position:0% +is similar to what we do during the +recitation sections from previous years + + align:start position:0% +recitation sections from previous years + + + align:start position:0% +recitation sections from previous years +to to go with the lecture videos done + + align:start position:0% +to to go with the lecture videos done + + + align:start position:0% +to to go with the lecture videos done +during the semester \ No newline at end of file diff --git a/xE9IGS-_6zo.txt b/xE9IGS-_6zo.txt new file mode 100644 index 0000000000000000000000000000000000000000..48f65850b6a3314ae29b4b20be0d78bb8e24fa91 --- /dev/null +++ b/xE9IGS-_6zo.txt @@ -0,0 +1,7771 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT OpenCourseWare continue to + + align:start position:0% +will help MIT OpenCourseWare continue to + + + align:start position:0% +will help MIT OpenCourseWare continue to +offer high quality educational resources + + align:start position:0% +offer high quality educational resources + + + align:start position:0% +offer high quality educational resources +for free + + align:start position:0% +for free + + + align:start position:0% +for free +to make a donation or to view additional + + align:start position:0% +to make a donation or to view additional + + + align:start position:0% +to make a donation or to view additional +materials from hundreds of MIT courses + + align:start position:0% +materials from hundreds of MIT courses + + + align:start position:0% +materials from hundreds of MIT courses +visit MIT opencourseware at ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +alright let's get started so today we're + + align:start position:0% +alright let's get started so today we're + + + align:start position:0% +alright let's get started so today we're +going to talk about boundary value + + align:start position:0% +going to talk about boundary value + + + align:start position:0% +going to talk about boundary value +problems but I'm going to try to start + + align:start position:0% +problems but I'm going to try to start + + + align:start position:0% +problems but I'm going to try to start +back with a motivating example so like + + align:start position:0% +back with a motivating example so like + + + align:start position:0% +back with a motivating example so like +unfortunately like most technologies the + + align:start position:0% +unfortunately like most technologies the + + + align:start position:0% +unfortunately like most technologies the +biggest driver for differential equation + + align:start position:0% +biggest driver for differential equation + + + align:start position:0% +biggest driver for differential equation +solutions was from military technology + + align:start position:0% +solutions was from military technology + + + align:start position:0% +solutions was from military technology +and the military problem I'll tell you + + align:start position:0% +and the military problem I'll tell you + + + align:start position:0% +and the military problem I'll tell you +in a second let me the first will remind + + align:start position:0% +in a second let me the first will remind + + + align:start position:0% +in a second let me the first will remind +you so we have OD e IV P's and they are + + align:start position:0% + + + + align:start position:0% + +right so that's that the OD IV piece we + + align:start position:0% +right so that's that the OD IV piece we + + + align:start position:0% +right so that's that the OD IV piece we +have in differential equations and we + + align:start position:0% +have in differential equations and we + + + align:start position:0% +have in differential equations and we +have n initial conditions all right and + + align:start position:0% +have n initial conditions all right and + + + align:start position:0% +have n initial conditions all right and +you guys are really good at these now a + + align:start position:0% +you guys are really good at these now a + + + align:start position:0% +you guys are really good at these now a +lot of practice but you can have + + align:start position:0% +lot of practice but you can have + + + align:start position:0% +lot of practice but you can have +problems where some of the conditions + + align:start position:0% +problems where some of the conditions + + + align:start position:0% +problems where some of the conditions +are not specified at the at T naught are + + align:start position:0% +are not specified at the at T naught are + + + align:start position:0% +are not specified at the at T naught are +specified somewhere else so if all of + + align:start position:0% +specified somewhere else so if all of + + + align:start position:0% +specified somewhere else so if all of +them are specified T naught we call it + + align:start position:0% +them are specified T naught we call it + + + align:start position:0% +them are specified T naught we call it +an IVP and it we call it a be VP is if + + align:start position:0% + + + + align:start position:0% + +the conditions are like this and not all + + align:start position:0% +the conditions are like this and not all + + + align:start position:0% +the conditions are like this and not all +the TMS are the same if all the teams + + align:start position:0% +the TMS are the same if all the teams + + + align:start position:0% +the TMS are the same if all the teams +are the same would call it t naught and + + align:start position:0% +are the same would call it t naught and + + + align:start position:0% +are the same would call it t naught and +we're back to IVP so IV feels like a + + align:start position:0% +we're back to IVP so IV feels like a + + + align:start position:0% +we're back to IVP so IV feels like a +special case of the OD BDD problem okay + + align:start position:0% +special case of the OD BDD problem okay + + + align:start position:0% +special case of the OD BDD problem okay +and here and write them as if + + align:start position:0% +and here and write them as if + + + align:start position:0% +and here and write them as if +everything's explicit so we know an + + align:start position:0% +everything's explicit so we know an + + + align:start position:0% +everything's explicit so we know an +explicit equation for dy DT we have an + + align:start position:0% +explicit equation for dy DT we have an + + + align:start position:0% +explicit equation for dy DT we have an +explicit equation for the boundary + + align:start position:0% +explicit equation for the boundary + + + align:start position:0% +explicit equation for the boundary +conditions in fact often we actually + + align:start position:0% +conditions in fact often we actually + + + align:start position:0% +conditions in fact often we actually +only have implicit equations so I'll + + align:start position:0% +only have implicit equations so I'll + + + align:start position:0% +only have implicit equations so I'll +show you an example in a minute + + align:start position:0% +show you an example in a minute + + + align:start position:0% +show you an example in a minute +all right that's it we still need to + + align:start position:0% +all right that's it we still need to + + + align:start position:0% +all right that's it we still need to +have n n equations well guess I can do + + align:start position:0% +have n n equations well guess I can do + + + align:start position:0% +have n n equations well guess I can do +this take this back I guess I call this + + align:start position:0% +this take this back I guess I call this + + + align:start position:0% +this take this back I guess I call this +n just be just be careful he's answered + + align:start position:0% +n just be just be careful he's answered + + + align:start position:0% +n just be just be careful he's answered +there's the same number of them + + align:start position:0% +there's the same number of them + + + align:start position:0% +there's the same number of them +there's sanitary conditions this is okay + + align:start position:0% +there's sanitary conditions this is okay + + + align:start position:0% +there's sanitary conditions this is okay +to write it this way but just be careful + + align:start position:0% +to write it this way but just be careful + + + align:start position:0% +to write it this way but just be careful +all right that's okay just to make it + + align:start position:0% +all right that's okay just to make it + + + align:start position:0% +all right that's okay just to make it +confusing all right that comes I guess + + align:start position:0% +confusing all right that comes I guess + + + align:start position:0% +confusing all right that comes I guess +think oh it's not now it's even though + + align:start position:0% +think oh it's not now it's even though + + + align:start position:0% +think oh it's not now it's even though +it's not really not right it's really + + align:start position:0% +it's not really not right it's really + + + align:start position:0% +it's not really not right it's really +maybe cold start at the boundary there's + + align:start position:0% +maybe cold start at the boundary there's + + + align:start position:0% +maybe cold start at the boundary there's +some special that some special place + + align:start position:0% +some special that some special place + + + align:start position:0% +some special that some special place +where you know the value of that Y okay + + align:start position:0% +where you know the value of that Y okay + + + align:start position:0% +where you know the value of that Y okay +all right so let's do the motivating + + align:start position:0% +all right so let's do the motivating + + + align:start position:0% +all right so let's do the motivating +example which comes from military + + align:start position:0% +example which comes from military + + + align:start position:0% +example which comes from military +technology and this is quite an old + + align:start position:0% +technology and this is quite an old + + + align:start position:0% +technology and this is quite an old +problem so because in the old days + + align:start position:0% +problem so because in the old days + + + align:start position:0% +problem so because in the old days +people didn't have motor vehicles and + + align:start position:0% +people didn't have motor vehicles and + + + align:start position:0% +people didn't have motor vehicles and +basically the roads were no good and + + align:start position:0% +basically the roads were no good and + + + align:start position:0% +basically the roads were no good and +there were a lot of bandits out on the + + align:start position:0% +there were a lot of bandits out on the + + + align:start position:0% +there were a lot of bandits out on the +roads people like to ship everything by + + align:start position:0% +roads people like to ship everything by + + + align:start position:0% +roads people like to ship everything by +water transportation and so all the + + align:start position:0% +water transportation and so all the + + + align:start position:0% +water transportation and so all the +towns grew up on rivers or on ports on + + align:start position:0% +towns grew up on rivers or on ports on + + + align:start position:0% +towns grew up on rivers or on ports on +the ocean and so if you lived in a nice + + align:start position:0% +the ocean and so if you lived in a nice + + + align:start position:0% +the ocean and so if you lived in a nice +little town you know there's up in the + + align:start position:0% +little town you know there's up in the + + + align:start position:0% +little town you know there's up in the +hills there and then the base of the + + align:start position:0% +hills there and then the base of the + + + align:start position:0% +hills there and then the base of the +hills + + align:start position:0% +hills + + + align:start position:0% +hills +you have your cute little town you have + + align:start position:0% +you have your cute little town you have + + + align:start position:0% +you have your cute little town you have +your house yeah some you know warehouses + + align:start position:0% +your house yeah some you know warehouses + + + align:start position:0% +your house yeah some you know warehouses +where you keep all your nice goods you + + align:start position:0% +where you keep all your nice goods you + + + align:start position:0% +where you keep all your nice goods you +have a dock that goes out onto the water + + align:start position:0% +have a dock that goes out onto the water + + + align:start position:0% +have a dock that goes out onto the water +here's the land here these nice ships + + align:start position:0% +here's the land here these nice ships + + + align:start position:0% +here's the land here these nice ships +come and park at the dock they unload + + align:start position:0% +come and park at the dock they unload + + + align:start position:0% +come and park at the dock they unload +nice good you trade your stuff to them + + align:start position:0% +nice good you trade your stuff to them + + + align:start position:0% +nice good you trade your stuff to them +you make a lot of money you're + + align:start position:0% +you make a lot of money you're + + + align:start position:0% +you make a lot of money you're +everyone's happy and prosperous and + + align:start position:0% +everyone's happy and prosperous and + + + align:start position:0% +everyone's happy and prosperous and +having a great time living those like + + align:start position:0% +having a great time living those like + + + align:start position:0% +having a great time living those like +poor city but then you look out on the + + align:start position:0% +poor city but then you look out on the + + + align:start position:0% +poor city but then you look out on the +horizon in the water and you see a ship + + align:start position:0% +horizon in the water and you see a ship + + + align:start position:0% +horizon in the water and you see a ship +is coming and sometimes the ship is + + align:start position:0% +is coming and sometimes the ship is + + + align:start position:0% +is coming and sometimes the ship is +coming is really good news for you but + + align:start position:0% +coming is really good news for you but + + + align:start position:0% +coming is really good news for you but +sometimes the ship coming is not good + + align:start position:0% +sometimes the ship coming is not good + + + align:start position:0% +sometimes the ship coming is not good +because on the back it has a flag and on + + align:start position:0% +because on the back it has a flag and on + + + align:start position:0% +because on the back it has a flag and on +the flag you see + + align:start position:0% + + + + align:start position:0% + +skull and crossbones and your eyes the + + align:start position:0% +skull and crossbones and your eyes the + + + align:start position:0% +skull and crossbones and your eyes the +Pirates are coming and now you're in + + align:start position:0% +Pirates are coming and now you're in + + + align:start position:0% +Pirates are coming and now you're in +serious trouble because you're really + + align:start position:0% +serious trouble because you're really + + + align:start position:0% +serious trouble because you're really +done with the Pirates to come to your + + align:start position:0% +done with the Pirates to come to your + + + align:start position:0% +done with the Pirates to come to your +nice little town because who knows what + + align:start position:0% +nice little town because who knows what + + + align:start position:0% +nice little town because who knows what +they'll do there but it won't be good + + align:start position:0% +they'll do there but it won't be good + + + align:start position:0% +they'll do there but it won't be good +all right so the people who live in this + + align:start position:0% +all right so the people who live in this + + + align:start position:0% +all right so the people who live in this +town after this happens to you a few + + align:start position:0% +town after this happens to you a few + + + align:start position:0% +town after this happens to you a few +times + + align:start position:0% +times + + + align:start position:0% +times +you're really alarmed and you're really + + align:start position:0% +you're really alarmed and you're really + + + align:start position:0% +you're really alarmed and you're really +unhappy and you don't want to rebuild + + align:start position:0% +unhappy and you don't want to rebuild + + + align:start position:0% +unhappy and you don't want to rebuild +your town encounters it just got burned + + align:start position:0% +your town encounters it just got burned + + + align:start position:0% +your town encounters it just got burned +down the last time when the Pirates came + + align:start position:0% +down the last time when the Pirates came + + + align:start position:0% +down the last time when the Pirates came +to pillaged and took everything and you + + align:start position:0% +to pillaged and took everything and you + + + align:start position:0% +to pillaged and took everything and you +guys all had to run away into the hills + + align:start position:0% +guys all had to run away into the hills + + + align:start position:0% +guys all had to run away into the hills +so instead they've been in cannons or + + align:start position:0% +so instead they've been in cannons or + + + align:start position:0% +so instead they've been in cannons or +catapults and you put one of the cannons + + align:start position:0% +catapults and you put one of the cannons + + + align:start position:0% +catapults and you put one of the cannons +say at the top of the hill above your + + align:start position:0% +say at the top of the hill above your + + + align:start position:0% +say at the top of the hill above your +town and then you say the next time the + + align:start position:0% +town and then you say the next time the + + + align:start position:0% +town and then you say the next time the +Pirates come I'm ready for them okay + + align:start position:0% +Pirates come I'm ready for them okay + + + align:start position:0% +Pirates come I'm ready for them okay +drawing the cannon + + align:start position:0% +drawing the cannon + + + align:start position:0% +drawing the cannon +alright and so the question is you want + + align:start position:0% +alright and so the question is you want + + + align:start position:0% +alright and so the question is you want +to shoot the Cannonball so it hits the + + align:start position:0% +to shoot the Cannonball so it hits the + + + align:start position:0% +to shoot the Cannonball so it hits the +pirate ship at the waterline when the + + align:start position:0% +pirate ship at the waterline when the + + + align:start position:0% +pirate ship at the waterline when the +pirate is a distance L from the shore + + align:start position:0% +pirate is a distance L from the shore + + + align:start position:0% +pirate is a distance L from the shore +hopefully pretty far so they're not + + align:start position:0% +hopefully pretty far so they're not + + + align:start position:0% +hopefully pretty far so they're not +going to shoot at you first and you're + + align:start position:0% +going to shoot at you first and you're + + + align:start position:0% +going to shoot at you first and you're +shooting for up to the top of the hill + + align:start position:0% +shooting for up to the top of the hill + + + align:start position:0% +shooting for up to the top of the hill +so you can shoot further than they can + + align:start position:0% +so you can shoot further than they can + + + align:start position:0% +so you can shoot further than they can +so you're gonna shoot distance L and + + align:start position:0% +so you're gonna shoot distance L and + + + align:start position:0% +so you're gonna shoot distance L and +your sheep on top from a elevation H + + align:start position:0% +your sheep on top from a elevation H + + + align:start position:0% +your sheep on top from a elevation H +okay and you want to make sure your + + align:start position:0% +okay and you want to make sure your + + + align:start position:0% +okay and you want to make sure your +cannonball hits them ideally right at + + align:start position:0% +cannonball hits them ideally right at + + + align:start position:0% +cannonball hits them ideally right at +the waterline boom makes a nice hole in + + align:start position:0% +the waterline boom makes a nice hole in + + + align:start position:0% +the waterline boom makes a nice hole in +their ship and they sinks okay so that's + + align:start position:0% +their ship and they sinks okay so that's + + + align:start position:0% +their ship and they sinks okay so that's +the plan now the the problem is she's + + align:start position:0% +the plan now the the problem is she's + + + align:start position:0% +the plan now the the problem is she's +getting the cannonball to go from here + + align:start position:0% +getting the cannonball to go from here + + + align:start position:0% +getting the cannonball to go from here +to there it's not so easy it's a big + + align:start position:0% +to there it's not so easy it's a big + + + align:start position:0% +to there it's not so easy it's a big +ocean there's a lot of place your cannon + + align:start position:0% +ocean there's a lot of place your cannon + + + align:start position:0% +ocean there's a lot of place your cannon +balls can fall into the ocean and it + + align:start position:0% +balls can fall into the ocean and it + + + align:start position:0% +balls can fall into the ocean and it +might not be with the pirate ship is and + + align:start position:0% +might not be with the pirate ship is and + + + align:start position:0% +might not be with the pirate ship is and +reloading a cannon is pretty slow and + + align:start position:0% +reloading a cannon is pretty slow and + + + align:start position:0% +reloading a cannon is pretty slow and +you guys live in this prosperous port + + align:start position:0% +you guys live in this prosperous port + + + align:start position:0% +you guys live in this prosperous port +you're not military guys and say you + + align:start position:0% +you're not military guys and say you + + + align:start position:0% +you're not military guys and say you +don't know how that much practice doing + + align:start position:0% +don't know how that much practice doing + + + align:start position:0% +don't know how that much practice doing +it anyway and you're cheap because + + align:start position:0% +it anyway and you're cheap because + + + align:start position:0% +it anyway and you're cheap because +you're merchants you don't want to spend + + align:start position:0% +you're merchants you don't want to spend + + + align:start position:0% +you're merchants you don't want to spend +your money buying lots of cannonballs + + align:start position:0% +your money buying lots of cannonballs + + + align:start position:0% +your money buying lots of cannonballs +anyway so you only have a few + + align:start position:0% +anyway so you only have a few + + + align:start position:0% +anyway so you only have a few +cannonballs up here there's a little + + align:start position:0% +cannonballs up here there's a little + + + align:start position:0% +cannonballs up here there's a little +pile cannonball next to the cannon and + + align:start position:0% +pile cannonball next to the cannon and + + + align:start position:0% +pile cannonball next to the cannon and +then when you see the pirate ship coming + + align:start position:0% +then when you see the pirate ship coming + + + align:start position:0% +then when you see the pirate ship coming +you guys run up the hill quick and you + + align:start position:0% +you guys run up the hill quick and you + + + align:start position:0% +you guys run up the hill quick and you +get to take you know a couple of shots + + align:start position:0% +get to take you know a couple of shots + + + align:start position:0% +get to take you know a couple of shots +and that's it and if you hit them then + + align:start position:0% +and that's it and if you hit them then + + + align:start position:0% +and that's it and if you hit them then +your town is safe and otherwise + + align:start position:0% +your town is safe and otherwise + + + align:start position:0% +your town is safe and otherwise +everything you love and know in your + + align:start position:0% +everything you love and know in your + + + align:start position:0% +everything you love and know in your +world is to be destroyed by the parts + + align:start position:0% +world is to be destroyed by the parts + + + align:start position:0% +world is to be destroyed by the parts +okay so this was the motivating example + + align:start position:0% +okay so this was the motivating example + + + align:start position:0% +okay so this was the motivating example +for the development of differential + + align:start position:0% +for the development of differential + + + align:start position:0% +for the development of differential +equation solvers okay + + align:start position:0% + + + + align:start position:0% + +so let's see if we can write down the + + align:start position:0% +so let's see if we can write down the + + + align:start position:0% +so let's see if we can write down the +equations that correspond to this + + align:start position:0% +equations that correspond to this + + + align:start position:0% +equations that correspond to this +example so it's gonna be Newton's laws F + + align:start position:0% +example so it's gonna be Newton's laws F + + + align:start position:0% +example so it's gonna be Newton's laws F +equals MA on the cannonball is it + + align:start position:0% +equals MA on the cannonball is it + + + align:start position:0% +equals MA on the cannonball is it +travels right so where we can write that + + align:start position:0% +travels right so where we can write that + + + align:start position:0% +travels right so where we can write that +also as equals well what's what's the DF + + align:start position:0% +also as equals well what's what's the DF + + + align:start position:0% +also as equals well what's what's the DF +so f is going to be negative mg mg in + + align:start position:0% +so f is going to be negative mg mg in + + + align:start position:0% +so f is going to be negative mg mg in +the Z direction all right + + align:start position:0% +the Z direction all right + + + align:start position:0% +the Z direction all right +that's gravity's pulling the Cannonball + + align:start position:0% +that's gravity's pulling the Cannonball + + + align:start position:0% +that's gravity's pulling the Cannonball +down and then they'll have some air + + align:start position:0% +down and then they'll have some air + + + align:start position:0% +down and then they'll have some air +friction on the Cannonball and I'm going + + align:start position:0% +friction on the Cannonball and I'm going + + + align:start position:0% +friction on the Cannonball and I'm going +to call the air friction coefficient + + align:start position:0% +to call the air friction coefficient + + + align:start position:0% +to call the air friction coefficient +gamma M times V okay so that's the + + align:start position:0% +gamma M times V okay so that's the + + + align:start position:0% +gamma M times V okay so that's the +simplest model for what the forces are + + align:start position:0% +simplest model for what the forces are + + + align:start position:0% +simplest model for what the forces are +unaccountable is this flying for my + + align:start position:0% +unaccountable is this flying for my + + + align:start position:0% +unaccountable is this flying for my +cannon + + align:start position:0% +cannon + + + align:start position:0% +cannon +hopefully did the pirate ship and I can + + align:start position:0% +hopefully did the pirate ship and I can + + + align:start position:0% +hopefully did the pirate ship and I can +rearrange this by dividing through by M + + align:start position:0% +rearrange this by dividing through by M + + + align:start position:0% +rearrange this by dividing through by M +so D net acceleration velocity said DV + + align:start position:0% +so D net acceleration velocity said DV + + + align:start position:0% +so D net acceleration velocity said DV +DT is equal to negative G okay sorry + + align:start position:0% +DT is equal to negative G okay sorry + + + align:start position:0% +DT is equal to negative G okay sorry +patience not so good okay everybody + + align:start position:0% +patience not so good okay everybody + + + align:start position:0% +patience not so good okay everybody +right with us yeah so then we can write + + align:start position:0% +right with us yeah so then we can write + + + align:start position:0% +right with us yeah so then we can write +the whole differential equation system c + + align:start position:0% +the whole differential equation system c + + + align:start position:0% +the whole differential equation system c +dt x e DX DZ equals DX dt is DX DZ DT is + + align:start position:0% +dt x e DX DZ equals DX dt is DX DZ DT is + + + align:start position:0% +dt x e DX DZ equals DX dt is DX DZ DT is +VZ d DX DT is negative gamma D X D DZ DT + + align:start position:0% +VZ d DX DT is negative gamma D X D DZ DT + + + align:start position:0% +VZ d DX DT is negative gamma D X D DZ DT +is negative G minus + + align:start position:0% +is negative G minus + + + align:start position:0% +is negative G minus +easy all right so that's a fine Eau de + + align:start position:0% +easy all right so that's a fine Eau de + + + align:start position:0% +easy all right so that's a fine Eau de +system it's not too hard to solve it's + + align:start position:0% +system it's not too hard to solve it's + + + align:start position:0% +system it's not too hard to solve it's +actually linear piece of cake + + align:start position:0% +actually linear piece of cake + + + align:start position:0% +actually linear piece of cake +right you guys probably do this already + + align:start position:0% +right you guys probably do this already + + + align:start position:0% +right you guys probably do this already +when you're in high school or college + + align:start position:0% +when you're in high school or college + + + align:start position:0% +when you're in high school or college +anyway for sure + + align:start position:0% +anyway for sure + + + align:start position:0% +anyway for sure +and let's write down the initial + + align:start position:0% +and let's write down the initial + + + align:start position:0% +and let's write down the initial +conditions so we know X of 0 is equal to + + align:start position:0% +conditions so we know X of 0 is equal to + + + align:start position:0% +conditions so we know X of 0 is equal to +0 Z of 0 is equal to H the height of the + + align:start position:0% +0 Z of 0 is equal to H the height of the + + + align:start position:0% +0 Z of 0 is equal to H the height of the +of the cannon the X of 0 oh it's that + + align:start position:0% +of the cannon the X of 0 oh it's that + + + align:start position:0% +of the cannon the X of 0 oh it's that +equal to we don't know V Z of 0 we don't + + align:start position:0% +equal to we don't know V Z of 0 we don't + + + align:start position:0% +equal to we don't know V Z of 0 we don't +know that either but we bought this + + align:start position:0% +know that either but we bought this + + + align:start position:0% +know that either but we bought this +cannon with a certified muzzle velocity + + align:start position:0% +cannon with a certified muzzle velocity + + + align:start position:0% +cannon with a certified muzzle velocity +B naught so we actually know that V X of + + align:start position:0% +B naught so we actually know that V X of + + + align:start position:0% +B naught so we actually know that V X of +0 squared plus V Z of 0 squared is equal + + align:start position:0% +0 squared plus V Z of 0 squared is equal + + + align:start position:0% +0 squared plus V Z of 0 squared is equal +to V naught squared whereas my my when I + + align:start position:0% +to V naught squared whereas my my when I + + + align:start position:0% +to V naught squared whereas my my when I +bought the cannon the merchants went out + + align:start position:0% +bought the cannon the merchants went out + + + align:start position:0% +bought the cannon the merchants went out +to the local cannon dealer and buy + + align:start position:0% +to the local cannon dealer and buy + + + align:start position:0% +to the local cannon dealer and buy +cannon and the guy said you put this + + align:start position:0% +cannon and the guy said you put this + + + align:start position:0% +cannon and the guy said you put this +much gunpowder in it you'll get a muzzle + + align:start position:0% +much gunpowder in it you'll get a muzzle + + + align:start position:0% +much gunpowder in it you'll get a muzzle +velocity of you know I said they know + + align:start position:0% +velocity of you know I said they know + + + align:start position:0% +velocity of you know I said they know +that that numbers so we have a condition + + align:start position:0% +that that numbers so we have a condition + + + align:start position:0% +that that numbers so we have a condition +that's not really the way we expect it + + align:start position:0% +that's not really the way we expect it + + + align:start position:0% +that's not really the way we expect it +to be and we don't have enough + + align:start position:0% +to be and we don't have enough + + + align:start position:0% +to be and we don't have enough +conditions we need four conditions but + + align:start position:0% +conditions we need four conditions but + + + align:start position:0% +conditions we need four conditions but +of course the most important condition + + align:start position:0% +of course the most important condition + + + align:start position:0% +of course the most important condition +is what happens at L we really want to + + align:start position:0% +is what happens at L we really want to + + + align:start position:0% +is what happens at L we really want to +know that X of T final is equal to L and + + align:start position:0% +know that X of T final is equal to L and + + + align:start position:0% +know that X of T final is equal to L and +y of T final is equal to zero sea level + + align:start position:0% +y of T final is equal to zero sea level + + + align:start position:0% +y of T final is equal to zero sea level +so that's that we are cannibals get in + + align:start position:0% +so that's that we are cannibals get in + + + align:start position:0% +so that's that we are cannibals get in +to the right location at T final so we + + align:start position:0% +to the right location at T final so we + + + align:start position:0% +to the right location at T final so we +have two conditions specified way way + + align:start position:0% +have two conditions specified way way + + + align:start position:0% +have two conditions specified way way +away from where we are and we have two + + align:start position:0% +away from where we are and we have two + + + align:start position:0% +away from where we are and we have two +conditions specified initially I know + + align:start position:0% +conditions specified initially I know + + + align:start position:0% +conditions specified initially I know +you have some oddball thing in here + + align:start position:0% +you have some oddball thing in here + + + align:start position:0% +you have some oddball thing in here +let's let my own behind ball v condition + + align:start position:0% +let's let my own behind ball v condition + + + align:start position:0% +let's let my own behind ball v condition +now okay one problem here is we don't + + align:start position:0% +now okay one problem here is we don't + + + align:start position:0% +now okay one problem here is we don't +actually know what T final is right + + align:start position:0% +actually know what T final is right + + + align:start position:0% +actually know what T final is right +because before we shoot we really don't + + align:start position:0% +because before we shoot we really don't + + + align:start position:0% +because before we shoot we really don't +know how long it takes the Cannonball to + + align:start position:0% +know how long it takes the Cannonball to + + + align:start position:0% +know how long it takes the Cannonball to +get out there so this is a kind of weird + + align:start position:0% +get out there so this is a kind of weird + + + align:start position:0% +get out there so this is a kind of weird +condition where T finals unknown where + + align:start position:0% +condition where T finals unknown where + + + align:start position:0% +condition where T finals unknown where +so once you're done before I think + + align:start position:0% +so once you're done before I think + + + align:start position:0% +so once you're done before I think +you've always known T final so right so + + align:start position:0% +you've always known T final so right so + + + align:start position:0% +you've always known T final so right so +let's talk about how to deal with that + + align:start position:0% + + + + align:start position:0% + +so one problem one one way to deal with + + align:start position:0% +so one problem one one way to deal with + + + align:start position:0% +so one problem one one way to deal with +us is to notice that if we have a + + align:start position:0% +us is to notice that if we have a + + + align:start position:0% +us is to notice that if we have a +equation system dy DT equals F of Y we + + align:start position:0% +equation system dy DT equals F of Y we + + + align:start position:0% +equation system dy DT equals F of Y we +could change variables instead of using + + align:start position:0% +could change variables instead of using + + + align:start position:0% +could change variables instead of using +T since we really don't know much about + + align:start position:0% +T since we really don't know much about + + + align:start position:0% +T since we really don't know much about +time in this problem T is not the best + + align:start position:0% +time in this problem T is not the best + + + align:start position:0% +time in this problem T is not the best +variable for us so we want to change it + + align:start position:0% +variable for us so we want to change it + + + align:start position:0% +variable for us so we want to change it +to some new variable U so suppose that + + align:start position:0% +to some new variable U so suppose that + + + align:start position:0% +to some new variable U so suppose that +we know what we want to change to you + + align:start position:0% +we know what we want to change to you + + + align:start position:0% +we know what we want to change to you +and if we change to you will have we can + + align:start position:0% +and if we change to you will have we can + + + align:start position:0% +and if we change to you will have we can +write something like this D why do you + + align:start position:0% +write something like this D why do you + + + align:start position:0% +write something like this D why do you +do you DT equals f of Y can you see that + + align:start position:0% +do you DT equals f of Y can you see that + + + align:start position:0% +do you DT equals f of Y can you see that +right so if I change I could try to get + + align:start position:0% +right so if I change I could try to get + + + align:start position:0% +right so if I change I could try to get +the differential is returned to you and + + align:start position:0% +the differential is returned to you and + + + align:start position:0% +the differential is returned to you and +I just have to know what my Dutt is and + + align:start position:0% +I just have to know what my Dutt is and + + + align:start position:0% +I just have to know what my Dutt is and +you guys might have been change the + + align:start position:0% +you guys might have been change the + + + align:start position:0% +you guys might have been change the +variable variables before in calculus + + align:start position:0% +variable variables before in calculus + + + align:start position:0% +variable variables before in calculus +some time you probably did this a long + + align:start position:0% +some time you probably did this a long + + + align:start position:0% +some time you probably did this a long +time ago and chain rule and stuff like + + align:start position:0% +time ago and chain rule and stuff like + + + align:start position:0% +time ago and chain rule and stuff like +that yeah all right so we can sort of + + align:start position:0% +that yeah all right so we can sort of + + + align:start position:0% +that yeah all right so we can sort of +pick whatever I do we want and as long + + align:start position:0% +pick whatever I do we want and as long + + + align:start position:0% +pick whatever I do we want and as long +as we put in the the Dutt in the + + align:start position:0% +as we put in the the Dutt in the + + + align:start position:0% +as we put in the the Dutt in the +equation it will be okay so let's let's + + align:start position:0% +equation it will be okay so let's let's + + + align:start position:0% +equation it will be okay so let's let's +just choose that U is equal to ax + + align:start position:0% +just choose that U is equal to ax + + + align:start position:0% +just choose that U is equal to ax +because we know Dutt would then be DX + + align:start position:0% +because we know Dutt would then be DX + + + align:start position:0% +because we know Dutt would then be DX +right so we could we could write this + + align:start position:0% +right so we could we could write this + + + align:start position:0% +right so we could we could write this +out this way we could write D I'll keep + + align:start position:0% +out this way we could write D I'll keep + + + align:start position:0% +out this way we could write D I'll keep +it as you for a minute so but the + + align:start position:0% +it as you for a minute so but the + + + align:start position:0% +it as you for a minute so but the +notation won't be so confusing so d we + + align:start position:0% +notation won't be so confusing so d we + + + align:start position:0% +notation won't be so confusing so d we +UDT py e edu is equal to f of y over u + + align:start position:0% +UDT py e edu is equal to f of y over u + + + align:start position:0% +UDT py e edu is equal to f of y over u +dt and as long as t du DT is never zero + + align:start position:0% +dt and as long as t du DT is never zero + + + align:start position:0% +dt and as long as t du DT is never zero +we're good so we could do any any we + + align:start position:0% +we're good so we could do any any we + + + align:start position:0% +we're good so we could do any any we +want as long as DT is never zero then we + + align:start position:0% +want as long as DT is never zero then we + + + align:start position:0% +want as long as DT is never zero then we +have we're still gonna have a nice + + align:start position:0% +have we're still gonna have a nice + + + align:start position:0% +have we're still gonna have a nice +simple equation here and so I'm gonna + + align:start position:0% +simple equation here and so I'm gonna + + + align:start position:0% +simple equation here and so I'm gonna +choose U is equal to X it's goes to UDC + + align:start position:0% +choose U is equal to X it's goes to UDC + + + align:start position:0% +choose U is equal to X it's goes to UDC +is VX and I know that VX is never zero + + align:start position:0% +is VX and I know that VX is never zero + + + align:start position:0% +is VX and I know that VX is never zero +the ball is always moving to the right + + align:start position:0% +the ball is always moving to the right + + + align:start position:0% +the ball is always moving to the right +okay so I'm gonna divide by something is + + align:start position:0% +okay so I'm gonna divide by something is + + + align:start position:0% +okay so I'm gonna divide by something is +not never zero so I can write it this + + align:start position:0% +not never zero so I can write it this + + + align:start position:0% +not never zero so I can write it this +way dy + + align:start position:0% +way dy + + + align:start position:0% +way dy +equal to thank you velvet list and + + align:start position:0% +equal to thank you velvet list and + + + align:start position:0% +equal to thank you velvet list and +divide each of these things by VX so + + align:start position:0% +divide each of these things by VX so + + + align:start position:0% +divide each of these things by VX so +it's one easy over B X negative gamma + + align:start position:0% +it's one easy over B X negative gamma + + + align:start position:0% +it's one easy over B X negative gamma +negative G over B X minus gamma easy + + align:start position:0% + + + + align:start position:0% + +that's my new okay is everybody okay + + align:start position:0% +that's my new okay is everybody okay + + + align:start position:0% +that's my new okay is everybody okay +with this so far energetic nodding yeah + + align:start position:0% +with this so far energetic nodding yeah + + + align:start position:0% +with this so far energetic nodding yeah +yeah sure keep going faster did you go + + align:start position:0% +yeah sure keep going faster did you go + + + align:start position:0% +yeah sure keep going faster did you go +you wait you slept that's what I want + + align:start position:0% +you wait you slept that's what I want + + + align:start position:0% +you wait you slept that's what I want +you to say yeah apparently not okay all + + align:start position:0% +you to say yeah apparently not okay all + + + align:start position:0% +you to say yeah apparently not okay all +right so the the advantage to changing + + align:start position:0% +right so the the advantage to changing + + + align:start position:0% +right so the the advantage to changing +here is that now I can write the initial + + align:start position:0% +here is that now I can write the initial + + + align:start position:0% +here is that now I can write the initial +conditions and that the all these + + align:start position:0% +conditions and that the all these + + + align:start position:0% +conditions and that the all these +conditions in terms of U which is X so I + + align:start position:0% +conditions in terms of U which is X so I + + + align:start position:0% +conditions in terms of U which is X so I +really I want to go from U is equal to 0 + + align:start position:0% +really I want to go from U is equal to 0 + + + align:start position:0% +really I want to go from U is equal to 0 +ie X equal to 0 to U is equal to L right + + align:start position:0% +ie X equal to 0 to U is equal to L right + + + align:start position:0% +ie X equal to 0 to U is equal to L right +so now I could also look at this and say + + align:start position:0% +so now I could also look at this and say + + + align:start position:0% +so now I could also look at this and say +this is kind of stupid dy to you the + + align:start position:0% +this is kind of stupid dy to you the + + + align:start position:0% +this is kind of stupid dy to you the +first component of Y is just do you want + + align:start position:0% +first component of Y is just do you want + + + align:start position:0% +first component of Y is just do you want +to U is equal to 1 and that first + + align:start position:0% +to U is equal to 1 and that first + + + align:start position:0% +to U is equal to 1 and that first +component of Y never appears and the + + align:start position:0% +component of Y never appears and the + + + align:start position:0% +component of Y never appears and the +rest of these equations so that's kind + + align:start position:0% +rest of these equations so that's kind + + + align:start position:0% +rest of these equations so that's kind +of not a very useful one so I can change + + align:start position:0% +of not a very useful one so I can change + + + align:start position:0% +of not a very useful one so I can change +and I could write a simpler equation do + + align:start position:0% +and I could write a simpler equation do + + + align:start position:0% +and I could write a simpler equation do +u Y tilde do u is equal to VZ over V X + + align:start position:0% +u Y tilde do u is equal to VZ over V X + + + align:start position:0% +u Y tilde do u is equal to VZ over V X +negative gamma negative G over B minus + + align:start position:0% +negative gamma negative G over B minus + + + align:start position:0% +negative gamma negative G over B minus +gamma V over V X where my Y tilde is + + align:start position:0% +gamma V over V X where my Y tilde is + + + align:start position:0% +gamma V over V X where my Y tilde is +just equal to the last three variables + + align:start position:0% +just equal to the last three variables + + + align:start position:0% +just equal to the last three variables +be sorry Z the X so right so I did a lot + + align:start position:0% +be sorry Z the X so right so I did a lot + + + align:start position:0% +be sorry Z the X so right so I did a lot +of algebra but I end up simplifying my + + align:start position:0% +of algebra but I end up simplifying my + + + align:start position:0% +of algebra but I end up simplifying my +life because I only have three different + + align:start position:0% +life because I only have three different + + + align:start position:0% +life because I only have three different +equations + + align:start position:0% + + + + align:start position:0% + +and I can write that y tilde 0 of the + + align:start position:0% +and I can write that y tilde 0 of the + + + align:start position:0% +and I can write that y tilde 0 of the +first element of Y tilde which is Z is + + align:start position:0% +first element of Y tilde which is Z is + + + align:start position:0% +first element of Y tilde which is Z is +equal to H so that's a condition I know + + align:start position:0% +equal to H so that's a condition I know + + + align:start position:0% +equal to H so that's a condition I know +for sure and I know that I really want + + align:start position:0% +for sure and I know that I really want + + + align:start position:0% +for sure and I know that I really want +this kind of ball to hit the pirate ship + + align:start position:0% +this kind of ball to hit the pirate ship + + + align:start position:0% +this kind of ball to hit the pirate ship +so I want Y 1 tilde of L to be 0 + + align:start position:0% +so I want Y 1 tilde of L to be 0 + + + align:start position:0% +so I want Y 1 tilde of L to be 0 +that's why 1 tilde is Z and I want C to + + align:start position:0% +that's why 1 tilde is Z and I want C to + + + align:start position:0% +that's why 1 tilde is Z and I want C to +be 0 at when the when X is equal to L + + align:start position:0% +be 0 at when the when X is equal to L + + + align:start position:0% +be 0 at when the when X is equal to L +all right that's the point where the + + align:start position:0% +all right that's the point where the + + + align:start position:0% +all right that's the point where the +kind of ball sitting the ship at the + + align:start position:0% +kind of ball sitting the ship at the + + + align:start position:0% +kind of ball sitting the ship at the +waterline over there + + align:start position:0% + + + + align:start position:0% + +so those are two two definitely two + + align:start position:0% +so those are two two definitely two + + + align:start position:0% +so those are two two definitely two +conditions I have and then I need a + + align:start position:0% +conditions I have and then I need a + + + align:start position:0% +conditions I have and then I need a +third condition and my third condition + + align:start position:0% +third condition and my third condition + + + align:start position:0% +third condition and my third condition +is this crazy equation here ok all right + + align:start position:0% +is this crazy equation here ok all right + + + align:start position:0% +is this crazy equation here ok all right +so now I have three conditions for three + + align:start position:0% +so now I have three conditions for three + + + align:start position:0% +so now I have three conditions for three +different equations and one of them is + + align:start position:0% +different equations and one of them is + + + align:start position:0% +different equations and one of them is +an oddball looking thing these two look + + align:start position:0% +an oddball looking thing these two look + + + align:start position:0% +an oddball looking thing these two look +kind of normal however this one's this + + align:start position:0% +kind of normal however this one's this + + + align:start position:0% +kind of normal however this one's this +one's a t naught and this one's it some + + align:start position:0% +one's a t naught and this one's it some + + + align:start position:0% +one's a t naught and this one's it some +goofball value but at least I know the + + align:start position:0% +goofball value but at least I know the + + + align:start position:0% +goofball value but at least I know the +value I know one else so now how far + + align:start position:0% +value I know one else so now how far + + + align:start position:0% +value I know one else so now how far +away the prior to this okay so far so + + align:start position:0% +away the prior to this okay so far so + + + align:start position:0% +away the prior to this okay so far so +good + + align:start position:0% +good + + + align:start position:0% +good +yeah all right so but how am I going to + + align:start position:0% +yeah all right so but how am I going to + + + align:start position:0% +yeah all right so but how am I going to +solve this so one you know how do we + + align:start position:0% +solve this so one you know how do we + + + align:start position:0% +solve this so one you know how do we +know how to solve differential equations + + align:start position:0% +know how to solve differential equations + + + align:start position:0% +know how to solve differential equations +right now is we know how to do initial + + align:start position:0% +right now is we know how to do initial + + + align:start position:0% +right now is we know how to do initial +value problems we have these nice + + align:start position:0% +value problems we have these nice + + + align:start position:0% +value problems we have these nice +programs like go to you for five that + + align:start position:0% +programs like go to you for five that + + + align:start position:0% +programs like go to you for five that +work great integrate differential + + align:start position:0% +work great integrate differential + + + align:start position:0% +work great integrate differential +equations so we should be able to use + + align:start position:0% +equations so we should be able to use + + + align:start position:0% +equations so we should be able to use +that somehow to solve this but we don't + + align:start position:0% +that somehow to solve this but we don't + + + align:start position:0% +that somehow to solve this but we don't +have all the inputs because ode45 would + + align:start position:0% +have all the inputs because ode45 would + + + align:start position:0% +have all the inputs because ode45 would +expect us to give values of all three of + + align:start position:0% +expect us to give values of all three of + + + align:start position:0% +expect us to give values of all three of +the Y tilde values at zero I only know + + align:start position:0% +the Y tilde values at zero I only know + + + align:start position:0% +the Y tilde values at zero I only know +one of them okay so how can I approach + + align:start position:0% +one of them okay so how can I approach + + + align:start position:0% +one of them okay so how can I approach +it I'm sorry I put my beautiful drawing + + align:start position:0% +it I'm sorry I put my beautiful drawing + + + align:start position:0% +it I'm sorry I put my beautiful drawing +down below + + align:start position:0% +down below + + + align:start position:0% +down below +we'll save us for posterity you can look + + align:start position:0% +we'll save us for posterity you can look + + + align:start position:0% +we'll save us for posterity you can look +at it later all right so I could + + align:start position:0% +at it later all right so I could + + + align:start position:0% +at it later all right so I could +approach it by saying well I don't know + + align:start position:0% +approach it by saying well I don't know + + + align:start position:0% +approach it by saying well I don't know +what these two initial conditions should + + align:start position:0% +what these two initial conditions should + + + align:start position:0% +what these two initial conditions should +be what V X and B Z should be at zero + + align:start position:0% +be what V X and B Z should be at zero + + + align:start position:0% +be what V X and B Z should be at zero +I'll treat them as unknowns I want to + + align:start position:0% +I'll treat them as unknowns I want to + + + align:start position:0% +I'll treat them as unknowns I want to +figure out what they should be in and so + + align:start position:0% +figure out what they should be in and so + + + align:start position:0% +figure out what they should be in and so +I'm going to vary those unknowns and + + align:start position:0% +I'm going to vary those unknowns and + + + align:start position:0% +I'm going to vary those unknowns and +then for each value I choose then I can + + align:start position:0% +then for each value I choose then I can + + + align:start position:0% +then for each value I choose then I can +shoot the cannon with those V's and I + + align:start position:0% +shoot the cannon with those V's and I + + + align:start position:0% +shoot the cannon with those V's and I +can see where the cannonball went and if + + align:start position:0% +can see where the cannonball went and if + + + align:start position:0% +can see where the cannonball went and if +it didn't go to the right location I can + + align:start position:0% +it didn't go to the right location I can + + + align:start position:0% +it didn't go to the right location I can +readjust those bees and then try again + + align:start position:0% +readjust those bees and then try again + + + align:start position:0% +readjust those bees and then try again +right just like if you were running the + + align:start position:0% +right just like if you were running the + + + align:start position:0% +right just like if you were running the +cannon you might add you know shoot the + + align:start position:0% +cannon you might add you know shoot the + + + align:start position:0% +cannon you might add you know shoot the +certain angle and then adjust the angle + + align:start position:0% +certain angle and then adjust the angle + + + align:start position:0% +certain angle and then adjust the angle +to Canada and shoot again and that when + + align:start position:0% +to Canada and shoot again and that when + + + align:start position:0% +to Canada and shoot again and that when +you change the angle you'll change the + + align:start position:0% +you change the angle you'll change the + + + align:start position:0% +you change the angle you'll change the +ratio of v x wy initially right so + + align:start position:0% +ratio of v x wy initially right so + + + align:start position:0% +ratio of v x wy initially right so +that's called the shooting method for + + align:start position:0% +that's called the shooting method for + + + align:start position:0% +that's called the shooting method for +good reason okay so this in the shooting + + align:start position:0% +good reason okay so this in the shooting + + + align:start position:0% +good reason okay so this in the shooting +method that's what we do is we guess the + + align:start position:0% +method that's what we do is we guess the + + + align:start position:0% +method that's what we do is we guess the +missing initial conditions then you + + align:start position:0% +missing initial conditions then you + + + align:start position:0% +missing initial conditions then you +solve using the gas saw the dod iv-e + + align:start position:0% +solve using the gas saw the dod iv-e + + + align:start position:0% +solve using the gas saw the dod iv-e +problem and then you see where what it + + align:start position:0% +problem and then you see where what it + + + align:start position:0% +problem and then you see where what it +computes and if if the solution you get + + align:start position:0% +computes and if if the solution you get + + + align:start position:0% +computes and if if the solution you get +doesn't satisfy the conditions you + + align:start position:0% +doesn't satisfy the conditions you + + + align:start position:0% +doesn't satisfy the conditions you +demand you go back and adjust your guess + + align:start position:0% + + + + align:start position:0% + +and you loop around okay so that's the + + align:start position:0% +and you loop around okay so that's the + + + align:start position:0% +and you loop around okay so that's the +idea now this thing of adjusting some + + align:start position:0% +idea now this thing of adjusting some + + + align:start position:0% +idea now this thing of adjusting some +parameter values some initial conditions + + align:start position:0% +parameter values some initial conditions + + + align:start position:0% +parameter values some initial conditions +to try to satisfy some condition that's + + align:start position:0% +to try to satisfy some condition that's + + + align:start position:0% +to try to satisfy some condition that's +like an F solve problem right that's a + + align:start position:0% +like an F solve problem right that's a + + + align:start position:0% +like an F solve problem right that's a +nonlinear system of nonlinear equations + + align:start position:0% +nonlinear system of nonlinear equations + + + align:start position:0% +nonlinear system of nonlinear equations +kind of problem so we're going to have F + + align:start position:0% +kind of problem so we're going to have F + + + align:start position:0% +kind of problem so we're going to have F +solve as the outside loop and that's + + align:start position:0% +solve as the outside loop and that's + + + align:start position:0% +solve as the outside loop and that's +gonna adjust some parameters and then + + align:start position:0% +gonna adjust some parameters and then + + + align:start position:0% +gonna adjust some parameters and then +what self self do so f self tries to + + align:start position:0% +what self self do so f self tries to + + + align:start position:0% +what self self do so f self tries to +solve problems the form G of usually + + align:start position:0% +solve problems the form G of usually + + + align:start position:0% +solve problems the form G of usually +right acts but cold be here + + align:start position:0% +right acts but cold be here + + + align:start position:0% +right acts but cold be here +no these not good either what letter + + align:start position:0% +no these not good either what letter + + + align:start position:0% +no these not good either what letter +have we have and not used yet any a + + align:start position:0% +have we have and not used yet any a + + + align:start position:0% +have we have and not used yet any a +letter Jeep W here we go G of W equals + + align:start position:0% +letter Jeep W here we go G of W equals + + + align:start position:0% +letter Jeep W here we go G of W equals +zero I want to figure out what W is I + + align:start position:0% +zero I want to figure out what W is I + + + align:start position:0% +zero I want to figure out what W is I +need to use okay and actually we can be + + align:start position:0% +need to use okay and actually we can be + + + align:start position:0% +need to use okay and actually we can be +is right we're trying to just the + + align:start position:0% +is right we're trying to just the + + + align:start position:0% +is right we're trying to just the +velocities right let's do sorry I'm + + align:start position:0% +velocities right let's do sorry I'm + + + align:start position:0% +velocities right let's do sorry I'm +messing up here it's good to use a racer + + align:start position:0% +messing up here it's good to use a racer + + + align:start position:0% +messing up here it's good to use a racer +in this class especially this nice big + + align:start position:0% +in this class especially this nice big + + + align:start position:0% +in this class especially this nice big +eraser all right all right so G V we're + + align:start position:0% +eraser all right all right so G V we're + + + align:start position:0% +eraser all right all right so G V we're +trying to adjust the velocities and to + + align:start position:0% +trying to adjust the velocities and to + + + align:start position:0% +trying to adjust the velocities and to +make something zero so what's our G that + + align:start position:0% +make something zero so what's our G that + + + align:start position:0% +make something zero so what's our G that +we're trying to we want we really want + + align:start position:0% +we're trying to we want we really want + + + align:start position:0% +we're trying to we want we really want +that the Z value at L we want that which + + align:start position:0% +that the Z value at L we want that which + + + align:start position:0% +that the Z value at L we want that which +this is we want that to be equal zero + + align:start position:0% +this is we want that to be equal zero + + + align:start position:0% +this is we want that to be equal zero +and this thing is like implicitly a + + align:start position:0% +and this thing is like implicitly a + + + align:start position:0% +and this thing is like implicitly a +function of the V's the V naught value + + align:start position:0% +function of the V's the V naught value + + + align:start position:0% +function of the V's the V naught value +so we get right if you put some if you + + align:start position:0% +so we get right if you put some if you + + + align:start position:0% +so we get right if you put some if you +put the right V naught values in then Z + + align:start position:0% +put the right V naught values in then Z + + + align:start position:0% +put the right V naught values in then Z +Adele would be zero okay so this is what + + align:start position:0% +Adele would be zero okay so this is what + + + align:start position:0% +Adele would be zero okay so this is what +we're really trying to solve now this is + + align:start position:0% +we're really trying to solve now this is + + + align:start position:0% +we're really trying to solve now this is +to get see eval we have to solve this + + align:start position:0% +to get see eval we have to solve this + + + align:start position:0% +to get see eval we have to solve this +system differential equations so it's a + + align:start position:0% +system differential equations so it's a + + + align:start position:0% +system differential equations so it's a +little complicated to go from V naught + + align:start position:0% +little complicated to go from V naught + + + align:start position:0% +little complicated to go from V naught +to Z all but we can do it as we have OD + + align:start position:0% +to Z all but we can do it as we have OD + + + align:start position:0% +to Z all but we can do it as we have OD +4 5 so we can write up a function to do + + align:start position:0% +4 5 so we can write up a function to do + + + align:start position:0% +4 5 so we can write up a function to do +this running out words + + align:start position:0% + + + + align:start position:0% + +all right so let's try to write the + + align:start position:0% +all right so let's try to write the + + + align:start position:0% +all right so let's try to write the +program so we want to front write the + + align:start position:0% +program so we want to front write the + + + align:start position:0% +program so we want to front write the +program G right so we want to write Z + + align:start position:0% +program G right so we want to write Z + + + align:start position:0% +program G right so we want to write Z +Val is equal to G you know okay + + align:start position:0% +Val is equal to G you know okay + + + align:start position:0% +Val is equal to G you know okay +and that's striking what this function + + align:start position:0% +and that's striking what this function + + + align:start position:0% +and that's striking what this function +is so we're going to the meat of this is + + align:start position:0% +is so we're going to the meat of this is + + + align:start position:0% +is so we're going to the meat of this is +we answer to solve a differential + + align:start position:0% +we answer to solve a differential + + + align:start position:0% +we answer to solve a differential +equation at IVP so somewhere here we + + align:start position:0% +equation at IVP so somewhere here we + + + align:start position:0% +equation at IVP so somewhere here we +have to go to you for five call what is + + align:start position:0% +have to go to you for five call what is + + + align:start position:0% +have to go to you for five call what is +OD or five computing it's computing the + + align:start position:0% +OD or five computing it's computing the + + + align:start position:0% +OD or five computing it's computing the +position the expositions and the C + + align:start position:0% +position the expositions and the C + + + align:start position:0% +position the expositions and the C +prediction C positions right and it's + + align:start position:0% +prediction C positions right and it's + + + align:start position:0% +prediction C positions right and it's +gonna use some function f which was lost + + align:start position:0% +gonna use some function f which was lost + + + align:start position:0% +gonna use some function f which was lost +in here nope + + align:start position:0% +in here nope + + + align:start position:0% +in here nope +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +sorry it's under the bow here I'm + + align:start position:0% +sorry it's under the bow here I'm + + + align:start position:0% +sorry it's under the bow here I'm +terrible board worker so this is our + + align:start position:0% +terrible board worker so this is our + + + align:start position:0% +terrible board worker so this is our +function f that's my right yeah so it's + + align:start position:0% +function f that's my right yeah so it's + + + align:start position:0% +function f that's my right yeah so it's +really F tilde slide that's the function + + align:start position:0% +really F tilde slide that's the function + + + align:start position:0% +really F tilde slide that's the function +that I'm gonna integrate and I can't + + align:start position:0% +that I'm gonna integrate and I can't + + + align:start position:0% +that I'm gonna integrate and I can't +remember that what are the arguments but + + align:start position:0% +remember that what are the arguments but + + + align:start position:0% +remember that what are the arguments but +it's me something like from zero to L + + align:start position:0% +it's me something like from zero to L + + + align:start position:0% +it's me something like from zero to L +and then I have to give it a why not and + + align:start position:0% +and then I have to give it a why not and + + + align:start position:0% +and then I have to give it a why not and +then we did some other stuff out there + + align:start position:0% +then we did some other stuff out there + + + align:start position:0% +then we did some other stuff out there +all right do you guys remember the ODU + + align:start position:0% +all right do you guys remember the ODU + + + align:start position:0% +all right do you guys remember the ODU +for five his diet is very water remember + + align:start position:0% +for five his diet is very water remember + + + align:start position:0% +for five his diet is very water remember +okay so I need to specify the why not + + align:start position:0% +okay so I need to specify the why not + + + align:start position:0% +okay so I need to specify the why not +so why not it's gonna be equal to the + + align:start position:0% +so why not it's gonna be equal to the + + + align:start position:0% +so why not it's gonna be equal to the +initial value of Z altitude so it's + + align:start position:0% +initial value of Z altitude so it's + + + align:start position:0% +initial value of Z altitude so it's +gonna be H and then it's the initial + + align:start position:0% +gonna be H and then it's the initial + + + align:start position:0% +gonna be H and then it's the initial +value of BX so I don't know what that is + + align:start position:0% +value of BX so I don't know what that is + + + align:start position:0% +value of BX so I don't know what that is +but it's funny it's maybe that's what + + align:start position:0% +but it's funny it's maybe that's what + + + align:start position:0% +but it's funny it's maybe that's what +called you not and then I haven't I do + + align:start position:0% +called you not and then I haven't I do + + + align:start position:0% +called you not and then I haven't I do +have one more condition here that V Z is + + align:start position:0% +have one more condition here that V Z is + + + align:start position:0% +have one more condition here that V Z is +related to V X so I can use that so I + + align:start position:0% +related to V X so I can use that so I + + + align:start position:0% +related to V X so I can use that so I +can have the last one be the square root + + align:start position:0% + + + + align:start position:0% + +so that's that's the line for what y + + align:start position:0% +so that's that's the line for what y + + + align:start position:0% +so that's that's the line for what y +know it is and then I saw this and then + + align:start position:0% +know it is and then I saw this and then + + + align:start position:0% +know it is and then I saw this and then +I write the number of steps and the time + + align:start position:0% +I write the number of steps and the time + + + align:start position:0% +I write the number of steps and the time +stepping program that did in order to + + align:start position:0% +stepping program that did in order to + + + align:start position:0% +stepping program that did in order to +get here was X 2x stepping in this case + + align:start position:0% +get here was X 2x stepping in this case + + + align:start position:0% +get here was X 2x stepping in this case +I'm steps is equal to the land x and z + + align:start position:0% +I'm steps is equal to the land x and z + + + align:start position:0% +I'm steps is equal to the land x and z +Val is equal to z vac + + align:start position:0% + + + + align:start position:0% + +so that's the function that you would + + align:start position:0% +so that's the function that you would + + + align:start position:0% +so that's the function that you would +feed to f solve and your correct value + + align:start position:0% +feed to f solve and your correct value + + + align:start position:0% +feed to f solve and your correct value +of VX 0 is the one that makes CL 0 which + + align:start position:0% +of VX 0 is the one that makes CL 0 which + + + align:start position:0% +of VX 0 is the one that makes CL 0 which +is what f stuff tries to do yeah you can + + align:start position:0% +is what f stuff tries to do yeah you can + + + align:start position:0% +is what f stuff tries to do yeah you can +but in the physical problem yeah usually + + align:start position:0% +but in the physical problem yeah usually + + + align:start position:0% +but in the physical problem yeah usually +canons always shoot upwards so what is + + align:start position:0% +canons always shoot upwards so what is + + + align:start position:0% +canons always shoot upwards so what is +the shippers oh yeah it could be either + + align:start position:0% +the shippers oh yeah it could be either + + + align:start position:0% +the shippers oh yeah it could be either +way yeah and in fact in this problem you + + align:start position:0% +way yeah and in fact in this problem you + + + align:start position:0% +way yeah and in fact in this problem you +might do better to change instead of + + align:start position:0% +might do better to change instead of + + + align:start position:0% +might do better to change instead of +using VX not as your unknown you might + + align:start position:0% +using VX not as your unknown you might + + + align:start position:0% +using VX not as your unknown you might +have a change to theta the angle the + + align:start position:0% +have a change to theta the angle the + + + align:start position:0% +have a change to theta the angle the +elevation angle the Canon and that would + + align:start position:0% +elevation angle the Canon and that would + + + align:start position:0% +elevation angle the Canon and that would +be more physical of what the actual user + + align:start position:0% +be more physical of what the actual user + + + align:start position:0% +be more physical of what the actual user +of the cannon is using their adjusting + + align:start position:0% +of the cannon is using their adjusting + + + align:start position:0% +of the cannon is using their adjusting +theta and not adjusting to the X here + + align:start position:0% +theta and not adjusting to the X here + + + align:start position:0% +theta and not adjusting to the X here +okay it's no problem actually right from + + align:start position:0% +okay it's no problem actually right from + + + align:start position:0% +okay it's no problem actually right from +the point of view of the F solve you can + + align:start position:0% +the point of view of the F solve you can + + + align:start position:0% +the point of view of the F solve you can +make this theta instead and then you'd + + align:start position:0% +make this theta instead and then you'd + + + align:start position:0% +make this theta instead and then you'd +have this be V naught times cosine theta + + align:start position:0% +have this be V naught times cosine theta + + + align:start position:0% +have this be V naught times cosine theta +and this VV v naught times sine of theta + + align:start position:0% +and this VV v naught times sine of theta + + + align:start position:0% +and this VV v naught times sine of theta +and then would work just as well do you + + align:start position:0% +and then would work just as well do you + + + align:start position:0% +and then would work just as well do you +the solution all right so that's the + + align:start position:0% +the solution all right so that's the + + + align:start position:0% +the solution all right so that's the +shooting method so this thing all this + + align:start position:0% +shooting method so this thing all this + + + align:start position:0% +shooting method so this thing all this +function G is the G that's going to be + + align:start position:0% +function G is the G that's going to be + + + align:start position:0% +function G is the G that's going to be +you'll have F solve so it's gonna say + + align:start position:0% +you'll have F solve so it's gonna say + + + align:start position:0% +you'll have F solve so it's gonna say +the X X naught is equal to F solve of G + + align:start position:0% +the X X naught is equal to F solve of G + + + align:start position:0% +the X X naught is equal to F solve of G +and then you have to have a guess all + + align:start position:0% +and then you have to have a guess all + + + align:start position:0% +and then you have to have a guess all +right for ourselves so that's how you + + align:start position:0% +right for ourselves so that's how you + + + align:start position:0% +right for ourselves so that's how you +would invoke this function all right and + + align:start position:0% +would invoke this function all right and + + + align:start position:0% +would invoke this function all right and +and so if we want to figure operation + + align:start position:0% +and so if we want to figure operation + + + align:start position:0% +and so if we want to figure operation +count of how many operations this is to + + align:start position:0% +count of how many operations this is to + + + align:start position:0% +count of how many operations this is to +find the solution this way how's it + + align:start position:0% +find the solution this way how's it + + + align:start position:0% +find the solution this way how's it +going + + align:start position:0% + + + + align:start position:0% + +and the ideas okay about how many + + align:start position:0% +and the ideas okay about how many + + + align:start position:0% +and the ideas okay about how many +iterations is to say to solve an eau de + + align:start position:0% +iterations is to say to solve an eau de + + + align:start position:0% +iterations is to say to solve an eau de +ivb that depends on the step size right + + align:start position:0% +ivb that depends on the step size right + + + align:start position:0% +ivb that depends on the step size right +it's adaptive usually dr. stepping so + + align:start position:0% +it's adaptive usually dr. stepping so + + + align:start position:0% +it's adaptive usually dr. stepping so +you you have some experience to that + + align:start position:0% +you you have some experience to that + + + align:start position:0% +you you have some experience to that +maybe 100 steps something like that this + + align:start position:0% +maybe 100 steps something like that this + + + align:start position:0% +maybe 100 steps something like that this +is usually enough maybe maybe thousand + + align:start position:0% +is usually enough maybe maybe thousand + + + align:start position:0% +is usually enough maybe maybe thousand +if it's not stiff and then how how many + + align:start position:0% +if it's not stiff and then how how many + + + align:start position:0% +if it's not stiff and then how how many +iterations does it take F solve this + + align:start position:0% +iterations does it take F solve this + + + align:start position:0% +iterations does it take F solve this +solve something + + align:start position:0% + + + + align:start position:0% + +tenth + + align:start position:0% +tenth + + + align:start position:0% +tenth +okay so you have maybe a thousand time + + align:start position:0% +okay so you have maybe a thousand time + + + align:start position:0% +okay so you have maybe a thousand time +steps maybe ten ten iterations means ten + + align:start position:0% +steps maybe ten ten iterations means ten + + + align:start position:0% +steps maybe ten ten iterations means ten +different value initial values that you + + align:start position:0% +different value initial values that you + + + align:start position:0% +different value initial values that you +try before you before you converts the + + align:start position:0% +try before you before you converts the + + + align:start position:0% +try before you before you converts the +solution and then you may have to + + align:start position:0% +solution and then you may have to + + + align:start position:0% +solution and then you may have to +actually compute the Jacobian of G right + + align:start position:0% +actually compute the Jacobian of G right + + + align:start position:0% +actually compute the Jacobian of G right +inside F soffits gonna use the Newton + + align:start position:0% +inside F soffits gonna use the Newton + + + align:start position:0% +inside F soffits gonna use the Newton +newton raphson step it's going to need + + align:start position:0% +newton raphson step it's going to need + + + align:start position:0% +newton raphson step it's going to need +the Jacobian of G the Jacobian of G + + align:start position:0% +the Jacobian of G the Jacobian of G + + + align:start position:0% +the Jacobian of G the Jacobian of G +takes the number of unknowns times + + align:start position:0% +takes the number of unknowns times + + + align:start position:0% +takes the number of unknowns times +number of function evaluations right it + + align:start position:0% +number of function evaluations right it + + + align:start position:0% +number of function evaluations right it +took computed by finite differences + + align:start position:0% +took computed by finite differences + + + align:start position:0% +took computed by finite differences +maybe two times that number so it's + + align:start position:0% +maybe two times that number so it's + + + align:start position:0% +maybe two times that number so it's +gonna be something like n squared will + + align:start position:0% +gonna be something like n squared will + + + align:start position:0% +gonna be something like n squared will +be and N squared to evaluate the + + align:start position:0% +be and N squared to evaluate the + + + align:start position:0% +be and N squared to evaluate the +Jacobian takes n operations to evaluate + + align:start position:0% +Jacobian takes n operations to evaluate + + + align:start position:0% +Jacobian takes n operations to evaluate +half so it would have been where n is + + align:start position:0% +half so it would have been where n is + + + align:start position:0% +half so it would have been where n is +number variables and times that to the + + align:start position:0% +number variables and times that to the + + + align:start position:0% +number variables and times that to the +Jacobian so if you like order number + + align:start position:0% +Jacobian so if you like order number + + + align:start position:0% +Jacobian so if you like order number +variables squared times ten times a + + align:start position:0% +variables squared times ten times a + + + align:start position:0% +variables squared times ten times a +thousand it's kind of order of the cost + + align:start position:0% +thousand it's kind of order of the cost + + + align:start position:0% +thousand it's kind of order of the cost +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and that's and it's only a thousand + + align:start position:0% +and that's and it's only a thousand + + + align:start position:0% +and that's and it's only a thousand +because it's only that cost because we + + align:start position:0% +because it's only that cost because we + + + align:start position:0% +because it's only that cost because we +can do explicit solver if you had to do + + align:start position:0% +can do explicit solver if you had to do + + + align:start position:0% +can do explicit solver if you had to do +an implicit OD solution to be a lot more + + align:start position:0% +an implicit OD solution to be a lot more + + + align:start position:0% +an implicit OD solution to be a lot more +right because you'd have to compute a + + align:start position:0% +right because you'd have to compute a + + + align:start position:0% +right because you'd have to compute a +jacobians more often alright so it's fun + + align:start position:0% +jacobians more often alright so it's fun + + + align:start position:0% +jacobians more often alright so it's fun +okay so this is a shooting method you + + align:start position:0% +okay so this is a shooting method you + + + align:start position:0% +okay so this is a shooting method you +guys should all do this no trouble + + align:start position:0% +guys should all do this no trouble + + + align:start position:0% +guys should all do this no trouble +conceptually this is not so different + + align:start position:0% +conceptually this is not so different + + + align:start position:0% +conceptually this is not so different +than the homework problem you did where + + align:start position:0% +than the homework problem you did where + + + align:start position:0% +than the homework problem you did where +you did an optimization of the parameter + + align:start position:0% +you did an optimization of the parameter + + + align:start position:0% +you did an optimization of the parameter +values remember she had some + + align:start position:0% +values remember she had some + + + align:start position:0% +values remember she had some +differential equations and you have to + + align:start position:0% +differential equations and you have to + + + align:start position:0% +differential equations and you have to +devise the parameters to try to find the + + align:start position:0% +devise the parameters to try to find the + + + align:start position:0% +devise the parameters to try to find the +best solutions here it's instead of + + align:start position:0% +best solutions here it's instead of + + + align:start position:0% +best solutions here it's instead of +optimizing them you're doing F solve + + align:start position:0% +optimizing them you're doing F solve + + + align:start position:0% +optimizing them you're doing F solve +you're trying to solve them to make + + align:start position:0% +you're trying to solve them to make + + + align:start position:0% +you're trying to solve them to make +something happen + + align:start position:0% +something happen + + + align:start position:0% +something happen +okay now how can this run into troubles + + align:start position:0% +okay now how can this run into troubles + + + align:start position:0% +okay now how can this run into troubles +why would the shooting problem not a + + align:start position:0% +why would the shooting problem not a + + + align:start position:0% +why would the shooting problem not a +cheesy method not always work everything + + align:start position:0% + + + + align:start position:0% + +okay so in a common case where that + + align:start position:0% +okay so in a common case where that + + + align:start position:0% +okay so in a common case where that +might happen be if your OD system was + + align:start position:0% +might happen be if your OD system was + + + align:start position:0% +might happen be if your OD system was +unstable right or your your OD solution + + align:start position:0% +unstable right or your your OD solution + + + align:start position:0% +unstable right or your your OD solution +method was not numerically unstable in + + align:start position:0% +method was not numerically unstable in + + + align:start position:0% +method was not numerically unstable in +either of those cases who knows what + + align:start position:0% +either of those cases who knows what + + + align:start position:0% +either of those cases who knows what +you're getting and actually don't know + + align:start position:0% +you're getting and actually don't know + + + align:start position:0% +you're getting and actually don't know +the solutions even real + + align:start position:0% +the solutions even real + + + align:start position:0% +the solutions even real +you don't know if the computed final + + align:start position:0% +you don't know if the computed final + + + align:start position:0% +you don't know if the computed final +value ZL is really what corresponds to + + align:start position:0% +value ZL is really what corresponds to + + + align:start position:0% +value ZL is really what corresponds to +that input value of VX 0 because if you + + align:start position:0% +that input value of VX 0 because if you + + + align:start position:0% +that input value of VX 0 because if you +have a big kind of numerical sensitivity + + align:start position:0% +have a big kind of numerical sensitivity + + + align:start position:0% +have a big kind of numerical sensitivity +and instability so that's one kind of + + align:start position:0% +and instability so that's one kind of + + + align:start position:0% +and instability so that's one kind of +problem so this is just like all the OD + + align:start position:0% +problem so this is just like all the OD + + + align:start position:0% +problem so this is just like all the OD +IBP problems if the Odie's problem + + align:start position:0% +IBP problems if the Odie's problem + + + align:start position:0% +IBP problems if the Odie's problem +intrinsically is unstable in a big way + + align:start position:0% +intrinsically is unstable in a big way + + + align:start position:0% +intrinsically is unstable in a big way +you're in trouble because your ears are + + align:start position:0% +you're in trouble because your ears are + + + align:start position:0% +you're in trouble because your ears are +going to amplify and then also if you + + align:start position:0% +going to amplify and then also if you + + + align:start position:0% +going to amplify and then also if you +use if you have a problem where the + + align:start position:0% +use if you have a problem where the + + + align:start position:0% +use if you have a problem where the +Delta T's are too large compared to the + + align:start position:0% +Delta T's are too large compared to the + + + align:start position:0% +Delta T's are too large compared to the +two this numerical stability of the + + align:start position:0% +two this numerical stability of the + + + align:start position:0% +two this numerical stability of the +solver you also have a problem right so + + align:start position:0% +solver you also have a problem right so + + + align:start position:0% +solver you also have a problem right so +those are two kinds of problem so we + + align:start position:0% +those are two kinds of problem so we + + + align:start position:0% +those are two kinds of problem so we +always have an OD each solutions and so + + align:start position:0% +always have an OD each solutions and so + + + align:start position:0% +always have an OD each solutions and so +you might actually want to use this + + align:start position:0% +you might actually want to use this + + + align:start position:0% +you might actually want to use this +method for some regular Oh de vie Biv + + align:start position:0% +method for some regular Oh de vie Biv + + + align:start position:0% +method for some regular Oh de vie Biv +problems so for example if you had a + + align:start position:0% +problems so for example if you had a + + + align:start position:0% +problems so for example if you had a +problem + + align:start position:0% +problem + + + align:start position:0% +problem +I don't want to wreck my beautiful + + align:start position:0% +I don't want to wreck my beautiful + + + align:start position:0% +I don't want to wreck my beautiful +artwork okay you guys did this if you + + align:start position:0% +artwork okay you guys did this if you + + + align:start position:0% +artwork okay you guys did this if you +had a problem that said dy DT is equal + + align:start position:0% +had a problem that said dy DT is equal + + + align:start position:0% +had a problem that said dy DT is equal +to 10 to the sixth times y yes yes well + + align:start position:0% +to 10 to the sixth times y yes yes well + + + align:start position:0% +to 10 to the sixth times y yes yes well +two ways so you could either solve it + + align:start position:0% +two ways so you could either solve it + + + align:start position:0% +two ways so you could either solve it +for repeated values different initial + + align:start position:0% +for repeated values different initial + + + align:start position:0% +for repeated values different initial +values of V naught and by find a + + align:start position:0% +values of V naught and by find a + + + align:start position:0% +values of V naught and by find a +difference get the Jacobian or you could + + align:start position:0% +difference get the Jacobian or you could + + + align:start position:0% +difference get the Jacobian or you could +use the sensitivity method that we did + + align:start position:0% +use the sensitivity method that we did + + + align:start position:0% +use the sensitivity method that we did +in the second problem a problem set it + + align:start position:0% +in the second problem a problem set it + + + align:start position:0% +in the second problem a problem set it +go and get analytically got the + + align:start position:0% +go and get analytically got the + + + align:start position:0% +go and get analytically got the +derivatives are respect to the + + align:start position:0% +derivatives are respect to the + + + align:start position:0% +derivatives are respect to the +parameters either way but either way + + align:start position:0% +parameters either way but either way + + + align:start position:0% +parameters either way but either way +it's a lot of work yeah so the the + + align:start position:0% +it's a lot of work yeah so the the + + + align:start position:0% +it's a lot of work yeah so the the +supposed a problem like this this is a + + align:start position:0% +supposed a problem like this this is a + + + align:start position:0% +supposed a problem like this this is a +pretty simple problem right and you want + + align:start position:0% +pretty simple problem right and you want + + + align:start position:0% +pretty simple problem right and you want +to suppose you wanted to go all the way + + align:start position:0% +to suppose you wanted to go all the way + + + align:start position:0% +to suppose you wanted to go all the way +out to T equals one now the problem is + + align:start position:0% +out to T equals one now the problem is + + + align:start position:0% +out to T equals one now the problem is +that this is a solution of this is a e + + align:start position:0% +that this is a solution of this is a e + + + align:start position:0% +that this is a solution of this is a e +to attend to this x times T something + + align:start position:0% +to attend to this x times T something + + + align:start position:0% +to attend to this x times T something +right so this is really not looking so + + align:start position:0% +right so this is really not looking so + + + align:start position:0% +right so this is really not looking so +great as a as a problem to solve this is + + align:start position:0% +great as a as a problem to solve this is + + + align:start position:0% +great as a as a problem to solve this is +about as unstable as you can get the + + align:start position:0% +about as unstable as you can get the + + + align:start position:0% +about as unstable as you can get the +tiniest little deviation anywhere along + + align:start position:0% +tiniest little deviation anywhere along + + + align:start position:0% +tiniest little deviation anywhere along +the way it's going to make the thing + + align:start position:0% +the way it's going to make the thing + + + align:start position:0% +the way it's going to make the thing +blow up and so this this is not so great + + align:start position:0% +blow up and so this this is not so great + + + align:start position:0% +blow up and so this this is not so great +and so even if the initial condition is + + align:start position:0% +and so even if the initial condition is + + + align:start position:0% +and so even if the initial condition is +that Y of T naught is equal ten to minus + + align:start position:0% +that Y of T naught is equal ten to minus + + + align:start position:0% +that Y of T naught is equal ten to minus +twelve so actually this is not so bad + + align:start position:0% +twelve so actually this is not so bad + + + align:start position:0% +twelve so actually this is not so bad +this is still a hard to solve + + align:start position:0% +this is still a hard to solve + + + align:start position:0% +this is still a hard to solve +numerically but you could flip it around + + align:start position:0% +numerically but you could flip it around + + + align:start position:0% +numerically but you could flip it around +and treat it as a shooting problem and + + align:start position:0% +and treat it as a shooting problem and + + + align:start position:0% +and treat it as a shooting problem and +solve it reverse so you could change + + align:start position:0% +solve it reverse so you could change + + + align:start position:0% +solve it reverse so you could change +variables that U is equal to negative T + + align:start position:0% +variables that U is equal to negative T + + + align:start position:0% +variables that U is equal to negative T +and then you'd have dy D you + + align:start position:0% +and then you'd have dy D you + + + align:start position:0% +and then you'd have dy D you +is equal to negative 10 to the 6 times y + + align:start position:0% +is equal to negative 10 to the 6 times y + + + align:start position:0% +is equal to negative 10 to the 6 times y +and now this is really stable and now + + align:start position:0% +and now this is really stable and now + + + align:start position:0% +and now this is really stable and now +you might want to integrate in so from + + align:start position:0% +you might want to integrate in so from + + + align:start position:0% +you might want to integrate in so from +its so the original question was what is + + align:start position:0% +its so the original question was what is + + + align:start position:0% +its so the original question was what is +why I want from the in the differential + + align:start position:0% +why I want from the in the differential + + + align:start position:0% +why I want from the in the differential +equations you could do the same you + + align:start position:0% +equations you could do the same you + + + align:start position:0% +equations you could do the same you +could do a reverse and say I'm gonna + + align:start position:0% +could do a reverse and say I'm gonna + + + align:start position:0% +could do a reverse and say I'm gonna +guess Y of 1 is equal to Y gasps and I'm + + align:start position:0% +guess Y of 1 is equal to Y gasps and I'm + + + align:start position:0% +guess Y of 1 is equal to Y gasps and I'm +gonna integrate it and demand that this + + align:start position:0% +gonna integrate it and demand that this + + + align:start position:0% +gonna integrate it and demand that this +is my final condition so now it's + + align:start position:0% +is my final condition so now it's + + + align:start position:0% +is my final condition so now it's +actually why I choose dumb confusing + + align:start position:0% +actually why I choose dumb confusing + + + align:start position:0% +actually why I choose dumb confusing +myself if I have negative 1 I guess I + + align:start position:0% +myself if I have negative 1 I guess I + + + align:start position:0% +myself if I have negative 1 I guess I +just put the sine T and hmm they only + + align:start position:0% +just put the sine T and hmm they only + + + align:start position:0% +just put the sine T and hmm they only +had just failed make it easier this way + + align:start position:0% +had just failed make it easier this way + + + align:start position:0% +had just failed make it easier this way +I'm minus T says the same derivative so + + align:start position:0% + + + + align:start position:0% + +y 0 2 I guess and y 1 is too much so + + align:start position:0% +y 0 2 I guess and y 1 is too much so + + + align:start position:0% +y 0 2 I guess and y 1 is too much so +this is my final condition that I'm + + align:start position:0% +this is my final condition that I'm + + + align:start position:0% +this is my final condition that I'm +trying to shoot to and I'll bury the Y + + align:start position:0% +trying to shoot to and I'll bury the Y + + + align:start position:0% +trying to shoot to and I'll bury the Y +guests integrate and now I have a + + align:start position:0% +guests integrate and now I have a + + + align:start position:0% +guests integrate and now I have a +perfectly stable differential equation I + + align:start position:0% +perfectly stable differential equation I + + + align:start position:0% +perfectly stable differential equation I +can solve it okay so this the same idea + + align:start position:0% +can solve it okay so this the same idea + + + align:start position:0% +can solve it okay so this the same idea +of shooting it comes up in mobile + + align:start position:0% +of shooting it comes up in mobile + + + align:start position:0% +of shooting it comes up in mobile +applications and this whole thing about + + align:start position:0% +applications and this whole thing about + + + align:start position:0% +applications and this whole thing about +flipping the changes of variables is + + align:start position:0% +flipping the changes of variables is + + + align:start position:0% +flipping the changes of variables is +often extremely useful trick to just + + align:start position:0% +often extremely useful trick to just + + + align:start position:0% +often extremely useful trick to just +recast equations in a way this more + + align:start position:0% +recast equations in a way this more + + + align:start position:0% +recast equations in a way this more +numerically stable to solve as fewer + + align:start position:0% +numerically stable to solve as fewer + + + align:start position:0% +numerically stable to solve as fewer +number equations you can write + + align:start position:0% +number equations you can write + + + align:start position:0% +number equations you can write +explicitly what you want but this takes + + align:start position:0% +explicitly what you want but this takes + + + align:start position:0% +explicitly what you want but this takes +some cleverness to know how to to recast + + align:start position:0% +some cleverness to know how to to recast + + + align:start position:0% +some cleverness to know how to to recast +them all right so so this this motivate + + align:start position:0% +them all right so so this this motivate + + + align:start position:0% +them all right so so this this motivate +example is is a good one yeah you could + + align:start position:0% +example is is a good one yeah you could + + + align:start position:0% +example is is a good one yeah you could +I was just trying to get back in the + + align:start position:0% +I was just trying to get back in the + + + align:start position:0% +I was just trying to get back in the +form of T naught equals 0 I guess I + + align:start position:0% +form of T naught equals 0 I guess I + + + align:start position:0% +form of T naught equals 0 I guess I +could have T naught equals negative 1 + + align:start position:0% +could have T naught equals negative 1 + + + align:start position:0% +could have T naught equals negative 1 +and do it I just can do the arithmetic + + align:start position:0% +and do it I just can do the arithmetic + + + align:start position:0% +and do it I just can do the arithmetic +on the work + + align:start position:0% + + + + align:start position:0% + +why of zeros know but that just start + + align:start position:0% +why of zeros know but that just start + + + align:start position:0% +why of zeros know but that just start +from T naught equals negative one so I + + align:start position:0% +from T naught equals negative one so I + + + align:start position:0% +from T naught equals negative one so I +could do sorry so suppose I did u equals + + align:start position:0% +could do sorry so suppose I did u equals + + + align:start position:0% +could do sorry so suppose I did u equals +negative T dy D u is equal to theta 1006 + + align:start position:0% +negative T dy D u is equal to theta 1006 + + + align:start position:0% +negative T dy D u is equal to theta 1006 +why and I know Y of Y of 0 is equal to + + align:start position:0% +why and I know Y of Y of 0 is equal to + + + align:start position:0% +why and I know Y of Y of 0 is equal to +know what do I know yeah Y of 0 is equal + + align:start position:0% +know what do I know yeah Y of 0 is equal + + + align:start position:0% +know what do I know yeah Y of 0 is equal +to 10 to the minus 12 and y of negative + + align:start position:0% +to 10 to the minus 12 and y of negative + + + align:start position:0% +to 10 to the minus 12 and y of negative +1 is equal to I guess and I can + + align:start position:0% +1 is equal to I guess and I can + + + align:start position:0% +1 is equal to I guess and I can +integrate from negative 1 over so this + + align:start position:0% +integrate from negative 1 over so this + + + align:start position:0% +integrate from negative 1 over so this +would be Tino on if I was using a + + align:start position:0% +would be Tino on if I was using a + + + align:start position:0% +would be Tino on if I was using a +shooting method and this would be T + + align:start position:0% +shooting method and this would be T + + + align:start position:0% +shooting method and this would be T +final yeah or you could shift it over by + + align:start position:0% +final yeah or you could shift it over by + + + align:start position:0% +final yeah or you could shift it over by +1 if you want to do the way I did you + + align:start position:0% +1 if you want to do the way I did you + + + align:start position:0% +1 if you want to do the way I did you +know what's all right sorry tell you if + + align:start position:0% +know what's all right sorry tell you if + + + align:start position:0% +know what's all right sorry tell you if +she's all the arithmetic guys getting + + align:start position:0% +she's all the arithmetic guys getting + + + align:start position:0% +she's all the arithmetic guys getting +confused - all right now I wrote this ok + + align:start position:0% +confused - all right now I wrote this ok + + + align:start position:0% +confused - all right now I wrote this ok +another another situation where this + + align:start position:0% +another another situation where this + + + align:start position:0% +another another situation where this +will not work is you can have systems + + align:start position:0% +will not work is you can have systems + + + align:start position:0% +will not work is you can have systems +where you have both positive and + + align:start position:0% +where you have both positive and + + + align:start position:0% +where you have both positive and +negative eigen values of the Jacobian + + align:start position:0% +negative eigen values of the Jacobian + + + align:start position:0% +negative eigen values of the Jacobian +and that means that either way you + + align:start position:0% +and that means that either way you + + + align:start position:0% +and that means that either way you +integrate from plus in the plus T + + align:start position:0% +integrate from plus in the plus T + + + align:start position:0% +integrate from plus in the plus T +direction or the negative T direction + + align:start position:0% +direction or the negative T direction + + + align:start position:0% +direction or the negative T direction +either way it's always unstable right so + + align:start position:0% +either way it's always unstable right so + + + align:start position:0% +either way it's always unstable right so +no matter what you do you're doomed + + align:start position:0% +no matter what you do you're doomed + + + align:start position:0% +no matter what you do you're doomed +right the IBP method is not going to + + align:start position:0% +right the IBP method is not going to + + + align:start position:0% +right the IBP method is not going to +work cuz you're numerically unstable in + + align:start position:0% +work cuz you're numerically unstable in + + + align:start position:0% +work cuz you're numerically unstable in +both directions and so that's kind of a + + align:start position:0% +both directions and so that's kind of a + + + align:start position:0% +both directions and so that's kind of a +really a bummer and it means are all our + + align:start position:0% +really a bummer and it means are all our + + + align:start position:0% +really a bummer and it means are all our +you know our div P methods not going to + + align:start position:0% +you know our div P methods not going to + + + align:start position:0% +you know our div P methods not going to +work for us and so then we have to find + + align:start position:0% +work for us and so then we have to find + + + align:start position:0% +work for us and so then we have to find +a different method but before before I + + align:start position:0% +a different method but before before I + + + align:start position:0% +a different method but before before I +go into that let's just write the more + + align:start position:0% +go into that let's just write the more + + + align:start position:0% +go into that let's just write the more +general version of this ok so this is I + + align:start position:0% +general version of this ok so this is I + + + align:start position:0% +general version of this ok so this is I +think you guys all know this + + align:start position:0% + + + + align:start position:0% + +so let's write a more general version of + + align:start position:0% +so let's write a more general version of + + + align:start position:0% +so let's write a more general version of +the ODB beefy problem and now will allow + + align:start position:0% +the ODB beefy problem and now will allow + + + align:start position:0% +the ODB beefy problem and now will allow +for the fact that things don't have to + + align:start position:0% +for the fact that things don't have to + + + align:start position:0% +for the fact that things don't have to +be explicit and don't have to be as + + align:start position:0% +be explicit and don't have to be as + + + align:start position:0% +be explicit and don't have to be as +simple as we thought and you could see + + align:start position:0% +simple as we thought and you could see + + + align:start position:0% +simple as we thought and you could see +even in the problem I just did we had a + + align:start position:0% +even in the problem I just did we had a + + + align:start position:0% +even in the problem I just did we had a +V x squared V 2 X square plus B Square + + align:start position:0% +V x squared V 2 X square plus B Square + + + align:start position:0% +V x squared V 2 X square plus B Square +and had to be equal something and so + + align:start position:0% +and had to be equal something and so + + + align:start position:0% +and had to be equal something and so +that's not a simple boundary condition + + align:start position:0% +that's not a simple boundary condition + + + align:start position:0% +that's not a simple boundary condition +like we saw it before so you know more + + align:start position:0% +like we saw it before so you know more + + + align:start position:0% +like we saw it before so you know more +complicated conditions and what you + + align:start position:0% +complicated conditions and what you + + + align:start position:0% +complicated conditions and what you +really can have is a set of equations GN + + align:start position:0% +really can have is a set of equations GN + + + align:start position:0% +really can have is a set of equations GN +of dy DT Y T is equal to 0 and + + align:start position:0% +of dy DT Y T is equal to 0 and + + + align:start position:0% +of dy DT Y T is equal to 0 and +corresponding sort of Q n of dy DT + + align:start position:0% +corresponding sort of Q n of dy DT + + + align:start position:0% +corresponding sort of Q n of dy DT +evaluated at TN y of TN TN is equal to 0 + + align:start position:0% +evaluated at TN y of TN TN is equal to 0 + + + align:start position:0% +evaluated at TN y of TN TN is equal to 0 +says this is the general Oh de system + + align:start position:0% +says this is the general Oh de system + + + align:start position:0% +says this is the general Oh de system +that's written in an implicit form and + + align:start position:0% +that's written in an implicit form and + + + align:start position:0% +that's written in an implicit form and +this has to be true for for all T in the + + align:start position:0% +this has to be true for for all T in the + + + align:start position:0% +this has to be true for for all T in the +domain + + align:start position:0% +domain + + + align:start position:0% +domain +I'll te that are a member of T naught to + + align:start position:0% +I'll te that are a member of T naught to + + + align:start position:0% +I'll te that are a member of T naught to +TF right so all the T's are inside this + + align:start position:0% +TF right so all the T's are inside this + + + align:start position:0% +TF right so all the T's are inside this +interval that we domain we care about + + align:start position:0% +interval that we domain we care about + + + align:start position:0% +interval that we domain we care about +this is the differential equation + + align:start position:0% +this is the differential equation + + + align:start position:0% +this is the differential equation +written is just as general as can be and + + align:start position:0% +written is just as general as can be and + + + align:start position:0% +written is just as general as can be and +n is equal to 1 there's n of these + + align:start position:0% +n is equal to 1 there's n of these + + + align:start position:0% +n is equal to 1 there's n of these +equations yeah + + align:start position:0% + + + + align:start position:0% + +I just want to make it clear that this + + align:start position:0% +I just want to make it clear that this + + + align:start position:0% +I just want to make it clear that this +is the conditions and this is the + + align:start position:0% +is the conditions and this is the + + + align:start position:0% +is the conditions and this is the +general equation I don't know you can + + align:start position:0% +general equation I don't know you can + + + align:start position:0% +general equation I don't know you can +write it any way you want + + align:start position:0% +write it any way you want + + + align:start position:0% +write it any way you want +so just like some variable letters + + align:start position:0% +so just like some variable letters + + + align:start position:0% +so just like some variable letters +instead of Q I can change this make them + + align:start position:0% +instead of Q I can change this make them + + + align:start position:0% +instead of Q I can change this make them +images yeah and this was this one I'm + + align:start position:0% +images yeah and this was this one I'm + + + align:start position:0% +images yeah and this was this one I'm +just trying to emphasize this one is + + align:start position:0% +just trying to emphasize this one is + + + align:start position:0% +just trying to emphasize this one is +only true at TN only this equation of + + align:start position:0% +only true at TN only this equation of + + + align:start position:0% +only true at TN only this equation of +this equation this is the condition at + + align:start position:0% +this equation this is the condition at + + + align:start position:0% +this equation this is the condition at +one particular time I demand something + + align:start position:0% +one particular time I demand something + + + align:start position:0% +one particular time I demand something +to be true and this is the general + + align:start position:0% +to be true and this is the general + + + align:start position:0% +to be true and this is the general +differential equation has to be true at + + align:start position:0% +differential equation has to be true at + + + align:start position:0% +differential equation has to be true at +all times + + align:start position:0% +all times + + + align:start position:0% +all times +and I need and if if I have n + + align:start position:0% +and I need and if if I have n + + + align:start position:0% +and I need and if if I have n +differentials I need in differential + + align:start position:0% +differentials I need in differential + + + align:start position:0% +differentials I need in differential +equations and in initial conditions by + + align:start position:0% +equations and in initial conditions by + + + align:start position:0% +equations and in initial conditions by +the way you can write the DA EES this + + align:start position:0% +the way you can write the DA EES this + + + align:start position:0% +the way you can write the DA EES this +way as well the differential algebraic + + align:start position:0% +way as well the differential algebraic + + + align:start position:0% +way as well the differential algebraic +equations and then he dos won't have as + + align:start position:0% +equations and then he dos won't have as + + + align:start position:0% +equations and then he dos won't have as +many initial conditions because every + + align:start position:0% +many initial conditions because every + + + align:start position:0% +many initial conditions because every +time you have an algebraic equation + + align:start position:0% +time you have an algebraic equation + + + align:start position:0% +time you have an algebraic equation +instead of a differential equation then + + align:start position:0% +instead of a differential equation then + + + align:start position:0% +instead of a differential equation then +you don't need an initial condition + + align:start position:0% +you don't need an initial condition + + + align:start position:0% +you don't need an initial condition +because the algebraic equation has its + + align:start position:0% +because the algebraic equation has its + + + align:start position:0% +because the algebraic equation has its +own its own condition + + align:start position:0% +own its own condition + + + align:start position:0% +own its own condition +so make sense alright so you can write + + align:start position:0% +so make sense alright so you can write + + + align:start position:0% +so make sense alright so you can write +this kind of in general and just by + + align:start position:0% +this kind of in general and just by + + + align:start position:0% +this kind of in general and just by +depending on how many differentials you + + align:start position:0% +depending on how many differentials you + + + align:start position:0% +depending on how many differentials you +have that's how many conditions you need + + align:start position:0% +have that's how many conditions you need + + + align:start position:0% +have that's how many conditions you need +and you know a lot of times you can + + align:start position:0% +and you know a lot of times you can + + + align:start position:0% +and you know a lot of times you can +write them explicit so you you this + + align:start position:0% +write them explicit so you you this + + + align:start position:0% +write them explicit so you you this +thing is equivalent to dy DT is equal to + + align:start position:0% +thing is equivalent to dy DT is equal to + + + align:start position:0% +thing is equivalent to dy DT is equal to +f of T y you know a lot many times you + + align:start position:0% +f of T y you know a lot many times you + + + align:start position:0% +f of T y you know a lot many times you +can solve for dy DT and write this way + + align:start position:0% +can solve for dy DT and write this way + + + align:start position:0% +can solve for dy DT and write this way +but not always okay all right and the + + align:start position:0% +but not always okay all right and the + + + align:start position:0% +but not always okay all right and the +reason why we need to have n conditions + + align:start position:0% +reason why we need to have n conditions + + + align:start position:0% +reason why we need to have n conditions +is just like when you're doing integrals + + align:start position:0% +is just like when you're doing integrals + + + align:start position:0% +is just like when you're doing integrals +you have n constants of integration + + align:start position:0% +you have n constants of integration + + + align:start position:0% +you have n constants of integration +every time you do an integral you get + + align:start position:0% +every time you do an integral you get + + + align:start position:0% +every time you do an integral you get +one now we have like three and we have n + + align:start position:0% +one now we have like three and we have n + + + align:start position:0% +one now we have like three and we have n +differential equations we'll have any + + align:start position:0% +differential equations we'll have any + + + align:start position:0% +differential equations we'll have any +conditions all right now a bad thing + + align:start position:0% +conditions all right now a bad thing + + + align:start position:0% +conditions all right now a bad thing +about these problems in general is that + + align:start position:0% +about these problems in general is that + + + align:start position:0% +about these problems in general is that +the solutions depend a lot on the + + align:start position:0% +the solutions depend a lot on the + + + align:start position:0% +the solutions depend a lot on the +boundary conditions and in fact you can + + align:start position:0% +boundary conditions and in fact you can + + + align:start position:0% +boundary conditions and in fact you can +write down boundary conditions that are + + align:start position:0% +write down boundary conditions that are + + + align:start position:0% +write down boundary conditions that are +not achievable which means there's no + + align:start position:0% +not achievable which means there's no + + + align:start position:0% +not achievable which means there's no +solution so this is really a bummer if + + align:start position:0% +solution so this is really a bummer if + + + align:start position:0% +solution so this is really a bummer if +you don't realize you did it because you + + align:start position:0% +you don't realize you did it because you + + + align:start position:0% +you don't realize you did it because you +can try solve it all day and you'll + + align:start position:0% +can try solve it all day and you'll + + + align:start position:0% +can try solve it all day and you'll +never solve it because it doesn't have a + + align:start position:0% +never solve it because it doesn't have a + + + align:start position:0% +never solve it because it doesn't have a +solution okay so for example in this + + align:start position:0% +solution okay so for example in this + + + align:start position:0% +solution okay so for example in this +problem if I set L to be too large the + + align:start position:0% +problem if I set L to be too large the + + + align:start position:0% +problem if I set L to be too large the +cannibal can't go that far I can't set L + + align:start position:0% +cannibal can't go that far I can't set L + + + align:start position:0% +cannibal can't go that far I can't set L +to be 3,000 kilometers and get a + + align:start position:0% +to be 3,000 kilometers and get a + + + align:start position:0% +to be 3,000 kilometers and get a +solution because the muzzle velocity is + + align:start position:0% +solution because the muzzle velocity is + + + align:start position:0% +solution because the muzzle velocity is +not high enough that the kind of ball is + + align:start position:0% +not high enough that the kind of ball is + + + align:start position:0% +not high enough that the kind of ball is +going to travel 3,000 kilometers but + + align:start position:0% +going to travel 3,000 kilometers but + + + align:start position:0% +going to travel 3,000 kilometers but +when I wrote the problem you didn't see + + align:start position:0% +when I wrote the problem you didn't see + + + align:start position:0% +when I wrote the problem you didn't see +that right you didn't come and tell me + + align:start position:0% +that right you didn't come and tell me + + + align:start position:0% +that right you didn't come and tell me +whoa watch out + + align:start position:0% +whoa watch out + + + align:start position:0% +whoa watch out +you know there's no way all could be + + align:start position:0% +you know there's no way all could be + + + align:start position:0% +you know there's no way all could be +bigger than such a touch okay and so you + + align:start position:0% +bigger than such a touch okay and so you + + + align:start position:0% +bigger than such a touch okay and so you +might not know it you might just you + + align:start position:0% +might not know it you might just you + + + align:start position:0% +might not know it you might just you +might specify a condition that's just + + align:start position:0% +might specify a condition that's just + + + align:start position:0% +might specify a condition that's just +not achievable I used to work an + + align:start position:0% +not achievable I used to work an + + + align:start position:0% +not achievable I used to work an +industry that's happened a lot manager + + align:start position:0% +industry that's happened a lot manager + + + align:start position:0% +industry that's happened a lot manager +would specify boundary conditions which + + align:start position:0% +would specify boundary conditions which + + + align:start position:0% +would specify boundary conditions which +were not achievable you know I want 99% + + align:start position:0% +were not achievable you know I want 99% + + + align:start position:0% +were not achievable you know I want 99% +yield and a 10% cost reduction go and + + align:start position:0% +yield and a 10% cost reduction go and + + + align:start position:0% +yield and a 10% cost reduction go and +now I'm the engineer I'm trying to work + + align:start position:0% +now I'm the engineer I'm trying to work + + + align:start position:0% +now I'm the engineer I'm trying to work +it out and then sometimes it didn't yeah + + align:start position:0% +it out and then sometimes it didn't yeah + + + align:start position:0% +it out and then sometimes it didn't yeah +so in some ways it's a lot better to + + align:start position:0% +so in some ways it's a lot better to + + + align:start position:0% +so in some ways it's a lot better to +just say max you know please maximize + + align:start position:0% +just say max you know please maximize + + + align:start position:0% +just say max you know please maximize +this as best you can subject to your + + align:start position:0% +this as best you can subject to your + + + align:start position:0% +this as best you can subject to your +constraints instead of specifying this + + align:start position:0% +constraints instead of specifying this + + + align:start position:0% +constraints instead of specifying this +but of course I don't know why there's a + + align:start position:0% +but of course I don't know why there's a + + + align:start position:0% +but of course I don't know why there's a +school management that says like we want + + align:start position:0% +school management that says like we want + + + align:start position:0% +school management that says like we want +definite targets we don't we don't want + + align:start position:0% +definite targets we don't we don't want + + + align:start position:0% +definite targets we don't we don't want +to be just the best we want to be + + align:start position:0% +to be just the best we want to be + + + align:start position:0% +to be just the best we want to be +perfect you know right so the No Child + + align:start position:0% +perfect you know right so the No Child + + + align:start position:0% +perfect you know right so the No Child +Left Behind every single student in this + + align:start position:0% +Left Behind every single student in this + + + align:start position:0% +Left Behind every single student in this +class is gonna really achieve that's it + + align:start position:0% +class is gonna really achieve that's it + + + align:start position:0% +class is gonna really achieve that's it +anyway that's that's that's the way + + align:start position:0% +anyway that's that's that's the way + + + align:start position:0% +anyway that's that's that's the way +targets get set but you know it's + + align:start position:0% +targets get set but you know it's + + + align:start position:0% +targets get set but you know it's +doesn't have to be achievable and it's + + align:start position:0% +doesn't have to be achievable and it's + + + align:start position:0% +doesn't have to be achievable and it's +actually a big branch of mathematics + + align:start position:0% +actually a big branch of mathematics + + + align:start position:0% +actually a big branch of mathematics +about trying to detect if the boundary + + align:start position:0% +about trying to detect if the boundary + + + align:start position:0% +about trying to detect if the boundary +conditions are indeed consistent so that + + align:start position:0% +conditions are indeed consistent so that + + + align:start position:0% +conditions are indeed consistent so that +they could be achieved and it's not so + + align:start position:0% +they could be achieved and it's not so + + + align:start position:0% +they could be achieved and it's not so +obvious to do it so I'm not gonna I'm + + align:start position:0% +obvious to do it so I'm not gonna I'm + + + align:start position:0% +obvious to do it so I'm not gonna I'm +not gonna get into that at all you could + + align:start position:0% +not gonna get into that at all you could + + + align:start position:0% +not gonna get into that at all you could +take a like a PDE class there's in the + + align:start position:0% +take a like a PDE class there's in the + + + align:start position:0% +take a like a PDE class there's in the +math department and that's all they talk + + align:start position:0% +math department and that's all they talk + + + align:start position:0% +math department and that's all they talk +about all day is about how to figure out + + align:start position:0% +about all day is about how to figure out + + + align:start position:0% +about all day is about how to figure out +you know are these boundary conditions + + align:start position:0% +you know are these boundary conditions + + + align:start position:0% +you know are these boundary conditions +consistent or not consistent you can + + align:start position:0% +consistent or not consistent you can + + + align:start position:0% +consistent or not consistent you can +also have boundary conditions are + + align:start position:0% +also have boundary conditions are + + + align:start position:0% +also have boundary conditions are +repetitive and don't have enough + + align:start position:0% +repetitive and don't have enough + + + align:start position:0% +repetitive and don't have enough +information in those cases you might + + align:start position:0% +information in those cases you might + + + align:start position:0% +information in those cases you might +have an infinite number of solutions and + + align:start position:0% +have an infinite number of solutions and + + + align:start position:0% +have an infinite number of solutions and +I think you can also have cases where + + align:start position:0% +I think you can also have cases where + + + align:start position:0% +I think you can also have cases where +you have multiple solutions so like in + + align:start position:0% +you have multiple solutions so like in + + + align:start position:0% +you have multiple solutions so like in +the Cannonball problem if you could have + + align:start position:0% +the Cannonball problem if you could have + + + align:start position:0% +the Cannonball problem if you could have +a negative UI and that the ship was + + align:start position:0% +a negative UI and that the ship was + + + align:start position:0% +a negative UI and that the ship was +close enough you might be able to shoot + + align:start position:0% +close enough you might be able to shoot + + + align:start position:0% +close enough you might be able to shoot +it two ways you could shoot shooting + + align:start position:0% +it two ways you could shoot shooting + + + align:start position:0% +it two ways you could shoot shooting +down at it or you could just follow up + + align:start position:0% +down at it or you could just follow up + + + align:start position:0% +down at it or you could just follow up +ahead up by and come down and they're + + align:start position:0% +ahead up by and come down and they're + + + align:start position:0% +ahead up by and come down and they're +both be solutions that satisfy all the + + align:start position:0% +both be solutions that satisfy all the + + + align:start position:0% +both be solutions that satisfy all the +conditions so is this is like general + + align:start position:0% +conditions so is this is like general + + + align:start position:0% +conditions so is this is like general +nonlinear equation problems that you + + align:start position:0% +nonlinear equation problems that you + + + align:start position:0% +nonlinear equation problems that you +don't know how many solutions you got + + align:start position:0% +don't know how many solutions you got + + + align:start position:0% +don't know how many solutions you got +you don't know if you have a solution + + align:start position:0% +you don't know if you have a solution + + + align:start position:0% +you don't know if you have a solution +you might have an infinite number of + + align:start position:0% +you might have an infinite number of + + + align:start position:0% +you might have an infinite number of +solutions you might have some finite + + align:start position:0% +solutions you might have some finite + + + align:start position:0% +solutions you might have some finite +number of solutions you don't know how + + align:start position:0% +number of solutions you don't know how + + + align:start position:0% +number of solutions you don't know how +many and it's just that's the way life + + align:start position:0% +many and it's just that's the way life + + + align:start position:0% +many and it's just that's the way life +is and you have to live with it but + + align:start position:0% +is and you have to live with it but + + + align:start position:0% +is and you have to live with it but +kind of annoying sometimes for now let's + + align:start position:0% +kind of annoying sometimes for now let's + + + align:start position:0% +kind of annoying sometimes for now let's +just assume that we somehow know that we + + align:start position:0% +just assume that we somehow know that we + + + align:start position:0% +just assume that we somehow know that we +have a unique solution there's a unique + + align:start position:0% +have a unique solution there's a unique + + + align:start position:0% +have a unique solution there's a unique +physical solution and we're just gonna + + align:start position:0% +physical solution and we're just gonna + + + align:start position:0% +physical solution and we're just gonna +try to find that and we're not gonna + + align:start position:0% +try to find that and we're not gonna + + + align:start position:0% +try to find that and we're not gonna +worry about this other problem about the + + align:start position:0% +worry about this other problem about the + + + align:start position:0% +worry about this other problem about the +fact that could actually be multiple + + align:start position:0% +fact that could actually be multiple + + + align:start position:0% +fact that could actually be multiple +solutions or no solution or whatever + + align:start position:0% +solutions or no solution or whatever + + + align:start position:0% +solutions or no solution or whatever +which you know when you actually run + + align:start position:0% +which you know when you actually run + + + align:start position:0% +which you know when you actually run +into a case like that then you'll really + + align:start position:0% +into a case like that then you'll really + + + align:start position:0% +into a case like that then you'll really +worry about it a lot good question + + align:start position:0% + + + + align:start position:0% + +all right so we had it we had an example + + align:start position:0% +all right so we had it we had an example + + + align:start position:0% +all right so we had it we had an example +in the actually the zeroth homework the + + align:start position:0% +in the actually the zeroth homework the + + + align:start position:0% +in the actually the zeroth homework the +very beginning that had a problem like + + align:start position:0% +very beginning that had a problem like + + + align:start position:0% +very beginning that had a problem like +this the homework 0p1 + + align:start position:0% + + + + align:start position:0% + +we had a problem where it was it gave + + align:start position:0% +we had a problem where it was it gave + + + align:start position:0% +we had a problem where it was it gave +you remember this it was like cylinder + + align:start position:0% +you remember this it was like cylinder + + + align:start position:0% +you remember this it was like cylinder +and you're trying to compute T of R or + + align:start position:0% +and you're trying to compute T of R or + + + align:start position:0% +and you're trying to compute T of R or +this and and it gave you some conditions + + align:start position:0% +this and and it gave you some conditions + + + align:start position:0% +this and and it gave you some conditions +about here so it gave you give you t + + align:start position:0% +about here so it gave you give you t + + + align:start position:0% +about here so it gave you give you t +when R was equal to R and it gave you + + align:start position:0% +when R was equal to R and it gave you + + + align:start position:0% +when R was equal to R and it gave you +DTD are actually give you some Quetta + + align:start position:0% +DTD are actually give you some Quetta + + + align:start position:0% +DTD are actually give you some Quetta +quai ssin it was a it was actually a + + align:start position:0% +quai ssin it was a it was actually a + + + align:start position:0% +quai ssin it was a it was actually a +function of this and T all of a + + align:start position:0% +function of this and T all of a + + + align:start position:0% +function of this and T all of a +evaluated at R was equal to something + + align:start position:0% +evaluated at R was equal to something + + + align:start position:0% +evaluated at R was equal to something +you remember this yeah so we gave you + + align:start position:0% +you remember this yeah so we gave you + + + align:start position:0% +you remember this yeah so we gave you +those two but then we also told you in + + align:start position:0% +those two but then we also told you in + + + align:start position:0% +those two but then we also told you in +the most recent homework oh by the way + + align:start position:0% +the most recent homework oh by the way + + + align:start position:0% +the most recent homework oh by the way +DTD are it's got to be equal to 0 at R + + align:start position:0% +DTD are it's got to be equal to 0 at R + + + align:start position:0% +DTD are it's got to be equal to 0 at R +equals 0 so this is one of these ones + + align:start position:0% +equals 0 so this is one of these ones + + + align:start position:0% +equals 0 so this is one of these ones +where we only have we should only have + + align:start position:0% +where we only have we should only have + + + align:start position:0% +where we only have we should only have +two conditions but we told you three + + align:start position:0% +two conditions but we told you three + + + align:start position:0% +two conditions but we told you three +conditions so then where it was any of + + align:start position:0% +conditions so then where it was any of + + + align:start position:0% +conditions so then where it was any of +you are able to achieve all three + + align:start position:0% +you are able to achieve all three + + + align:start position:0% +you are able to achieve all three +conditions no ok so this is this is + + align:start position:0% +conditions no ok so this is this is + + + align:start position:0% +conditions no ok so this is this is +highlighting the problem right so we + + align:start position:0% +highlighting the problem right so we + + + align:start position:0% +highlighting the problem right so we +gave you three boundary conditions are + + align:start position:0% +gave you three boundary conditions are + + + align:start position:0% +gave you three boundary conditions are +apparently incompatible that you + + align:start position:0% +apparently incompatible that you + + + align:start position:0% +apparently incompatible that you +couldn't actually solve them all at the + + align:start position:0% +couldn't actually solve them all at the + + + align:start position:0% +couldn't actually solve them all at the +same time so beware I guess now in that + + align:start position:0% +same time so beware I guess now in that + + + align:start position:0% +same time so beware I guess now in that +problem it might have been more natural + + align:start position:0% +problem it might have been more natural + + + align:start position:0% +problem it might have been more natural +to give you this equation which we are + + align:start position:0% +to give you this equation which we are + + + align:start position:0% +to give you this equation which we are +sure is exactly true + + align:start position:0% +sure is exactly true + + + align:start position:0% +sure is exactly true +by the symmetry situation as one of the + + align:start position:0% +by the symmetry situation as one of the + + + align:start position:0% +by the symmetry situation as one of the +conditions and then only one of these + + align:start position:0% +conditions and then only one of these + + + align:start position:0% +conditions and then only one of these +other conditions out + + align:start position:0% +other conditions out + + + align:start position:0% +other conditions out +that whichever one we were more sure was + + align:start position:0% +that whichever one we were more sure was + + + align:start position:0% +that whichever one we were more sure was +correct might be the thing to do and so + + align:start position:0% +correct might be the thing to do and so + + + align:start position:0% +correct might be the thing to do and so +we kind of you know gave you some + + align:start position:0% +we kind of you know gave you some + + + align:start position:0% +we kind of you know gave you some +goofball conditions I guess in some ways + + align:start position:0% +goofball conditions I guess in some ways + + + align:start position:0% +goofball conditions I guess in some ways +right yeah they could all be true and if + + align:start position:0% +right yeah they could all be true and if + + + align:start position:0% +right yeah they could all be true and if +they were all true then then if you saw + + align:start position:0% +they were all true then then if you saw + + + align:start position:0% +they were all true then then if you saw +the numerically exactly you should you + + align:start position:0% +the numerically exactly you should you + + + align:start position:0% +the numerically exactly you should you +should get the real solution it should + + align:start position:0% +should get the real solution it should + + + align:start position:0% +should get the real solution it should +satisfy all of them + + align:start position:0% + + + + align:start position:0% + +yeah I think that I think one wasn't + + align:start position:0% +yeah I think that I think one wasn't + + + align:start position:0% +yeah I think that I think one wasn't +true and I think it's maybe due to + + align:start position:0% +true and I think it's maybe due to + + + align:start position:0% +true and I think it's maybe due to +roundoff yeah so but it's highlights a + + align:start position:0% +roundoff yeah so but it's highlights a + + + align:start position:0% +roundoff yeah so but it's highlights a +problem if you have three conditions + + align:start position:0% +problem if you have three conditions + + + align:start position:0% +problem if you have three conditions +that should be true but they evolved + + align:start position:0% +that should be true but they evolved + + + align:start position:0% +that should be true but they evolved +numbers in them then often they won't + + align:start position:0% +numbers in them then often they won't + + + align:start position:0% +numbers in them then often they won't +all be exactly consistent with each + + align:start position:0% +all be exactly consistent with each + + + align:start position:0% +all be exactly consistent with each +other but those are actually worse kind + + align:start position:0% +other but those are actually worse kind + + + align:start position:0% +other but those are actually worse kind +of problem right because it's like it's + + align:start position:0% +of problem right because it's like it's + + + align:start position:0% +of problem right because it's like it's +close to being consistent to all those + + align:start position:0% +close to being consistent to all those + + + align:start position:0% +close to being consistent to all those +conditions but you're not exactly + + align:start position:0% +conditions but you're not exactly + + + align:start position:0% +conditions but you're not exactly +conditioning consistent but then if you + + align:start position:0% +conditioning consistent but then if you + + + align:start position:0% +conditioning consistent but then if you +get into it trying to figure out what's + + align:start position:0% +get into it trying to figure out what's + + + align:start position:0% +get into it trying to figure out what's +going on a lot of times you'll get like + + align:start position:0% +going on a lot of times you'll get like + + + align:start position:0% +going on a lot of times you'll get like +new your singular matrices and stuff + + align:start position:0% +new your singular matrices and stuff + + + align:start position:0% +new your singular matrices and stuff +because you have things that are nearly + + align:start position:0% +because you have things that are nearly + + + align:start position:0% +because you have things that are nearly +linearly dependent in some way so really + + align:start position:0% +linearly dependent in some way so really + + + align:start position:0% +linearly dependent in some way so really +it's better if you just have the right + + align:start position:0% +it's better if you just have the right + + + align:start position:0% +it's better if you just have the right +number of conditions that you're really + + align:start position:0% +number of conditions that you're really + + + align:start position:0% +number of conditions that you're really +sure really specify everything correctly + + align:start position:0% +sure really specify everything correctly + + + align:start position:0% +sure really specify everything correctly +and just go with those and treat the + + align:start position:0% +and just go with those and treat the + + + align:start position:0% +and just go with those and treat the +ones that you think would be nice if + + align:start position:0% +ones that you think would be nice if + + + align:start position:0% +ones that you think would be nice if +they were true as like approximate + + align:start position:0% +they were true as like approximate + + + align:start position:0% +they were true as like approximate +things that are sort of physical checks + + align:start position:0% +things that are sort of physical checks + + + align:start position:0% +things that are sort of physical checks +to see what your solutions reasonable + + align:start position:0% +to see what your solutions reasonable + + + align:start position:0% +to see what your solutions reasonable +and we did it sort of like that in the + + align:start position:0% +and we did it sort of like that in the + + + align:start position:0% +and we did it sort of like that in the +problem you did we said well you know + + align:start position:0% +problem you did we said well you know + + + align:start position:0% +problem you did we said well you know +DTD r should really be equal to zero but + + align:start position:0% +DTD r should really be equal to zero but + + + align:start position:0% +DTD r should really be equal to zero but +we didn't demand that in your solution + + align:start position:0% +we didn't demand that in your solution + + + align:start position:0% +we didn't demand that in your solution +your solution didn't actually satisfy + + align:start position:0% +your solution didn't actually satisfy + + + align:start position:0% +your solution didn't actually satisfy +that and you we use that as a measure of + + align:start position:0% +that and you we use that as a measure of + + + align:start position:0% +that and you we use that as a measure of +how far off your solution is that's + + align:start position:0% +how far off your solution is that's + + + align:start position:0% +how far off your solution is that's +actually pretty useful in practice you + + align:start position:0% +actually pretty useful in practice you + + + align:start position:0% +actually pretty useful in practice you +get a solution it's good to have some + + align:start position:0% +get a solution it's good to have some + + + align:start position:0% +get a solution it's good to have some +additional condition that you can test + + align:start position:0% +additional condition that you can test + + + align:start position:0% +additional condition that you can test +for like physical reasonableness of the + + align:start position:0% +for like physical reasonableness of the + + + align:start position:0% +for like physical reasonableness of the +solution and particularly cuz this + + align:start position:0% +solution and particularly cuz this + + + align:start position:0% +solution and particularly cuz this +problem that you might have multiple + + align:start position:0% +problem that you might have multiple + + + align:start position:0% +problem that you might have multiple +solutions and maybe one of them is a + + align:start position:0% +solutions and maybe one of them is a + + + align:start position:0% +solutions and maybe one of them is a +physical solution and one is some other + + align:start position:0% +physical solution and one is some other + + + align:start position:0% +physical solution and one is some other +crazy solution and so you you need to + + align:start position:0% +crazy solution and so you you need to + + + align:start position:0% +crazy solution and so you you need to +have some way to detect the crazy + + align:start position:0% +have some way to detect the crazy + + + align:start position:0% +have some way to detect the crazy +solution by some other condition you can + + align:start position:0% +solution by some other condition you can + + + align:start position:0% +solution by some other condition you can +test does it make sense yeah all right + + align:start position:0% +test does it make sense yeah all right + + + align:start position:0% +test does it make sense yeah all right +so I said I said you know you could have + + align:start position:0% +so I said I said you know you could have + + + align:start position:0% +so I said I said you know you could have +cases where the Jacobian of + + align:start position:0% +cases where the Jacobian of + + + align:start position:0% +cases where the Jacobian of +your equation yeah so you can be trying + + align:start position:0% +your equation yeah so you can be trying + + + align:start position:0% +your equation yeah so you can be trying +to solve this and it could be for some + + align:start position:0% +to solve this and it could be for some + + + align:start position:0% +to solve this and it could be for some +problems that Jacobian always has both + + align:start position:0% +problems that Jacobian always has both + + + align:start position:0% +problems that Jacobian always has both +positive and negative eigenvalues + + align:start position:0% +positive and negative eigenvalues + + + align:start position:0% +positive and negative eigenvalues +together and in that case using I VPS + + align:start position:0% +together and in that case using I VPS + + + align:start position:0% +together and in that case using I VPS +it's not going to be a smart idea + + align:start position:0% +it's not going to be a smart idea + + + align:start position:0% +it's not going to be a smart idea +because you no matter which direction + + align:start position:0% +because you no matter which direction + + + align:start position:0% +because you no matter which direction +you integrate in you're gonna have a + + align:start position:0% +you integrate in you're gonna have a + + + align:start position:0% +you integrate in you're gonna have a +positive eigenvalue and so then the the + + align:start position:0% +positive eigenvalue and so then the the + + + align:start position:0% +positive eigenvalue and so then the the +ivv is not good and so instead we're + + align:start position:0% +ivv is not good and so instead we're + + + align:start position:0% +ivv is not good and so instead we're +gonna use a different methods and we'll + + align:start position:0% +gonna use a different methods and we'll + + + align:start position:0% +gonna use a different methods and we'll +talk about that next time and those are + + align:start position:0% +talk about that next time and those are + + + align:start position:0% +talk about that next time and those are +called relaxation methods and the + + align:start position:0% +called relaxation methods and the + + + align:start position:0% +called relaxation methods and the +concept of these is different than it + + align:start position:0% +concept of these is different than it + + + align:start position:0% +concept of these is different than it +was for shooting so the relaxation + + align:start position:0% +was for shooting so the relaxation + + + align:start position:0% +was for shooting so the relaxation +methods is you have a white gas that + + align:start position:0% +methods is you have a white gas that + + + align:start position:0% +methods is you have a white gas that +you're gonna have the whole guess for + + align:start position:0% +you're gonna have the whole guess for + + + align:start position:0% +you're gonna have the whole guess for +the entire Y throughout the whole domain + + align:start position:0% +the entire Y throughout the whole domain + + + align:start position:0% +the entire Y throughout the whole domain +and actually a lot of times you might + + align:start position:0% +and actually a lot of times you might + + + align:start position:0% +and actually a lot of times you might +you might set this up so that why I + + align:start position:0% +you might set this up so that why I + + + align:start position:0% +you might set this up so that why I +guess actually exactly satisfies the + + align:start position:0% +guess actually exactly satisfies the + + + align:start position:0% +guess actually exactly satisfies the +boundary conditions so you know it + + align:start position:0% +boundary conditions so you know it + + + align:start position:0% +boundary conditions so you know it +satisfies those equations right from the + + align:start position:0% +satisfies those equations right from the + + + align:start position:0% +satisfies those equations right from the +beginning just from the way you set up I + + align:start position:0% +beginning just from the way you set up I + + + align:start position:0% +beginning just from the way you set up I +guess but it won't satisfy the + + align:start position:0% +guess but it won't satisfy the + + + align:start position:0% +guess but it won't satisfy the +differential equation and then what + + align:start position:0% +differential equation and then what + + + align:start position:0% +differential equation and then what +you'll do is you'll say you know how + + align:start position:0% +you'll do is you'll say you know how + + + align:start position:0% +you'll do is you'll say you know how +badly does it fail to satisfy G and + + align:start position:0% +badly does it fail to satisfy G and + + + align:start position:0% +badly does it fail to satisfy G and +equals you know the G is equal zero all + + align:start position:0% +equals you know the G is equal zero all + + + align:start position:0% +equals you know the G is equal zero all +right because who really wants G's equal + + align:start position:0% +right because who really wants G's equal + + + align:start position:0% +right because who really wants G's equal +to zero for the true solution and we'll + + align:start position:0% +to zero for the true solution and we'll + + + align:start position:0% +to zero for the true solution and we'll +call this this failure of our Y guest to + + align:start position:0% +call this this failure of our Y guest to + + + align:start position:0% +call this this failure of our Y guest to +solve this we'll call that the residual + + align:start position:0% +solve this we'll call that the residual + + + align:start position:0% +solve this we'll call that the residual +so we can actually plug in y guess in + + align:start position:0% +so we can actually plug in y guess in + + + align:start position:0% +so we can actually plug in y guess in +here and y guess in here and evaluate + + align:start position:0% +here and y guess in here and evaluate + + + align:start position:0% +here and y guess in here and evaluate +this and normally it will not be 0 + + align:start position:0% +this and normally it will not be 0 + + + align:start position:0% +this and normally it will not be 0 +because our y guess there's not perfect + + align:start position:0% +because our y guess there's not perfect + + + align:start position:0% +because our y guess there's not perfect +and so it's going to deviate from zero + + align:start position:0% +and so it's going to deviate from zero + + + align:start position:0% +and so it's going to deviate from zero +but how big a deviates from zero is + + align:start position:0% +but how big a deviates from zero is + + + align:start position:0% +but how big a deviates from zero is +going to be our measure of how bad that + + align:start position:0% +going to be our measure of how bad that + + + align:start position:0% +going to be our measure of how bad that +that guess was and then we're going to + + align:start position:0% +that guess was and then we're going to + + + align:start position:0% +that guess was and then we're going to +try to change Y gas to try to make it + + align:start position:0% +try to change Y gas to try to make it + + + align:start position:0% +try to change Y gas to try to make it +closer and closer to zero so the idea is + + align:start position:0% +closer and closer to zero so the idea is + + + align:start position:0% +closer and closer to zero so the idea is +relax it you get a incorrect solution + + align:start position:0% +relax it you get a incorrect solution + + + align:start position:0% +relax it you get a incorrect solution +and you adjust it to relax it to make it + + align:start position:0% +and you adjust it to relax it to make it + + + align:start position:0% +and you adjust it to relax it to make it +become the correct solution alright and + + align:start position:0% +become the correct solution alright and + + + align:start position:0% +become the correct solution alright and +so that's the the general idea of the + + align:start position:0% +so that's the the general idea of the + + + align:start position:0% +so that's the the general idea of the +relaxation methods and we'll talk about + + align:start position:0% +relaxation methods and we'll talk about + + + align:start position:0% +relaxation methods and we'll talk about +several different forms of that normally + + align:start position:0% +several different forms of that normally + + + align:start position:0% +several different forms of that normally +what we have to do is you have to write + + align:start position:0% +what we have to do is you have to write + + + align:start position:0% +what we have to do is you have to write +why guess and some in terms of some + + align:start position:0% +why guess and some in terms of some + + + align:start position:0% +why guess and some in terms of some +parameters so why guess T depends on + + align:start position:0% +parameters so why guess T depends on + + + align:start position:0% +parameters so why guess T depends on +some parameters and we're gonna adjust + + align:start position:0% +some parameters and we're gonna adjust + + + align:start position:0% +some parameters and we're gonna adjust +the parameters and that's going to + + align:start position:0% +the parameters and that's going to + + + align:start position:0% +the parameters and that's going to +change what Y guesses and so for example + + align:start position:0% +change what Y guesses and so for example + + + align:start position:0% +change what Y guesses and so for example +we could do a basis set expansion as we + + align:start position:0% +we could do a basis set expansion as we + + + align:start position:0% +we could do a basis set expansion as we +did one of the earlier classes we talked + + align:start position:0% +did one of the earlier classes we talked + + + align:start position:0% +did one of the earlier classes we talked +about how you could expand Y guests as a + + align:start position:0% +about how you could expand Y guests as a + + + align:start position:0% +about how you could expand Y guests as a +sum of some basis functions weighted by + + align:start position:0% +sum of some basis functions weighted by + + + align:start position:0% +sum of some basis functions weighted by +peas and then you can adjust the peas + + align:start position:0% +peas and then you can adjust the peas + + + align:start position:0% +peas and then you can adjust the peas +and find the best possible set of peas + + align:start position:0% +and find the best possible set of peas + + + align:start position:0% +and find the best possible set of peas +to get them to make this G as close to + + align:start position:0% +to get them to make this G as close to + + + align:start position:0% +to get them to make this G as close to +zero as possible for example but we'll + + align:start position:0% +zero as possible for example but we'll + + + align:start position:0% +zero as possible for example but we'll +give examples of that next time and talk + + align:start position:0% +give examples of that next time and talk + + + align:start position:0% +give examples of that next time and talk +about there's a several choices about + + align:start position:0% +about there's a several choices about + + + align:start position:0% +about there's a several choices about +that all right \ No newline at end of file diff --git a/xEnYH0KNkfA.txt b/xEnYH0KNkfA.txt new file mode 100644 index 0000000000000000000000000000000000000000..3683202ea6a6e6e26780c4f5318838e5451fea49 --- /dev/null +++ b/xEnYH0KNkfA.txt @@ -0,0 +1,2915 @@ +The following content is +provided under a Creative + +Commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high-quality educational +resources for free. + +To make a donation or view +additional material from + +hundreds of MIT courses, visit +MIT OpenCourseWare at + +ocw.mit.edu. + +PROFESSOR: All right. + +So today we're going to start +the last section. + +We're going to do three lectures +on phase diagrams. + +And I've given this the label +here of Stability, Sustaining + +the Solid State. + +We've talked a lot about the +solid state in 3.091 as the + +vehicle for teaching the +rudiments of chemistry. + +One of the things we have not +talked about, is what are the + +conditions that sustain +the solid state? + +How do I know whether +something's going to be a + +solid, or a liquid, or a gas? + +This is very important. + +For example, if you're in a +foundry, you're running + +places, making auto parts, +you have to know what the + +solidification temperature is of +the alloys, so you can get + +the parts out quickly and +keep productivity high. + +It's even important in +failure analysis. + +You know, when they were looking +at things like the + +rubble from the World Trade +Center by understanding phase + +stability, the thermal history +was imprinted in the metal. + +It's possible to determine +what temperatures were + +achieved, and therefore, what +the chain of events was that + +led to the collapse of +those buildings. + +Now you might say, well, isn't +this straightforward? + +I mean, for example, you just +look up the melting point or + +boiling point. + +Water, 0 degrees C. Melting +point, boiling point, 100 + +degrees C. + +Well, suppose you decide to +realize your life's ambition. + +You're going to go and +scale Mount Everest. + +So you pay the $10,000, you +get a license from the + +Nepalese Government, +and you're at base + +camp at 20,000 feet. + +You're sitting there, you've +got your campfire going, + +you've got a hankering for +a hard-boiled egg. + +And you start, you put the eggs +into boiling water and + +you cook them 10 minutes, you +take them out, and they're + +still runny. + +You say, I must've lost +track of time. + +So you cook them 20 minutes, +and they're still runny. + +And you cook them 30 minutes, +and they're still runny. + +And you eventually come to the +realization that at 20,000 + +feet, the boiling point of water +is below the denaturing + +temperature of egg yolk. + +So now the boiling point is +a function of pressure. + +So you know, we could have one +of these Iron Chef cookoffs, + +only the dish is souffle, only +we'll have the contest at + +Flagstaff, Arizona, where the +altitude is so high that the + +classical recipes won't work, +because the boiling point, the + +atmospheric pressure, and +everything conspire so that + +you're not going to be able +to support the souffle. + +So you're going to have to +understand phase diagrams. + +In fact, if you understand phase +diagrams, that's your + +ticket to being a four-star +chef in the kitchen. + +Well, here's another place we +can look at, where pressure + +has an important role. + +Let's look under the +hood of a car. + +You're running an internal +combustion engine. + +So this is the engine +block, and there's + +combustion going on inside. + +We've got to keep this thing +from overeating. + +It could damage the metal. + +In extreme, you could +melt the metal. + +So we've got cooling channels +in here with water flow. + +But then the water's going +to heat up, and the + +water's going to boil. + +So we've got, over here, +the radiator. + +So it's really a double +cooling system. + +The water cools the block, +and then the + +radiator cools the water. + +So how's that going to work? + +Well, here, the temperature is +on the order of about 90 + +degrees C, and here the +temperature inside the engine + +block is much greater than 90 +degrees C. It's several + +hundred degrees C inside that +engine block, and we've got + +water going like this. + +So we've got cooling water +flow in this manner. + +And now cold water goes in and +hot water comes out, and then + +we get into the radiator, and +we've got channels here, and + +we've either got a fan or +some kind of air flow. + +And so now, what's +the gambit here? + +I want to see what's going +on inside this radiator. + +So if this is the wall of the +radiator, and in here I've got + +water, and over here I've got +air, the idea is to have a + +high heat flux to get the energy +out of the water and + +cool it down. + +Now, if things get really, +really hot in here-- let's say + +you're zooming along down the +highway at about 90, I mean, + +about 65 miles an hour, and all +of a sudden you come upon + +a collision, and you have to +go to a dead stop, all that + +energy in the engine +is now dumped, and + +the water could overheat. + +And in the extreme, if it +overheats, it can actually go + +into a boil. + +And this is bad. + +Because heat transfer is really +good between a liquid + +and a solid, and it's +really poor + +between a gas and a solid. + +This is a low heat flux, +and this is bad. + +High heat flux, that's good. + +This is the bubbles. + +This is boiling. + +And why? + +Because what transfers energy? + +It's the atoms. + +And what's the atom density in +a liquid versus the atom + +density in a gas? + +You just have really crummy +heat transfer. + +That's why insulation involves +dead airspace. + +Because you have very +poor atom density. + +So what can we do in +order to try to + +repress the bubble formation? + +Well, we said if we went up +Mount Everest, we went to high + +altitude, the boiling +point went down. + +And why did it go down? + +Because the atmospheric +pressure is lower. + +So why don't we go the inverse +here, and we'll put a pressure + +cap on the radiator, and make +the pressure go up, and when + +the pressure goes up, it exerts +a back pressure and + +represses bubble formation? + +So by increasing pressure, we +can increase the temperature, + +and get the temperature up. + +So let's say p equals-- if you +look on the top of the + +pressure cap, it will +say 15 psi. + +And 15 psi is almost 14.7 psi, +which is exactly 1 atmosphere, + +which in SI units is, and I know +this to six significant + +figures, 101325 Pascals. + +Or, you know, from Torricelli, +760 millimeters of mercury, + +that's the column that's +supported. + +So we're at 2 atmospheres +pressure in there, and with + +two atmospheres of pressure, we +can raise the boiling point + +to 106 degrees C. And then what +we can do, is now change + +the composition. + +So we change the pressure, and +I change the boiling point. + +I change the composition. + +add 50% ethylene glycol. + +So now I've got a +one-to-one mix, + +ethylene glycol and water. + +And that takes the boiling point +up to 130 degrees C, or + +265 degrees Fahrenheit. + +So another example of how +we can manage systems. + +So when I'm showing you by these +several examples, is + +that the boiling point is a +function of pressure and + +composition. + +So we can tune the +boiling point. + +See we were tuning materials +properties before. + +Now we're tuning physical +chemical properties, because + +that's what chemistry +is all about. + +It's about control. + +It's about management. + +Management to advantage. + +So how do we know +what to do here? + +Can we predict this from +first principles? + +No. + +Systems are still +too complicated. + +Our models aren't +robust enough. + +So instead, we turn +to an archive. + +So we have phase diagrams. + +And the phase diagrams guide +us in our search for better + +management of material +systems. + +And these are stability maps. + +They tell us which phases are +stable under which conditions + +of pressure, temperature, +composition. + +You can consider them +as archives. + +So that's what I want to talk +about, because it's really + +important to know this stuff. + +OK. + +So what are we going to do? + +So first of all, let's-- + +I don't want to write +on that one. + +This is interesting. + +This could be a work of art. + +I'd hate to desecrate it. + +You like? + +This is really good! + +So I'm just going +to leave that. + +That's very good. + +That's excellent. + +OK. + +So I've been talking +about phase. + +What is a phase? + +Let's get the right +definition here. + +What is a phase? + +It's a region uniform chemical +composition. + +Just to get it down. + +it's a region in a material, +region of uniform chemical + +composition, and it has these +other properties. + +Uniform chemical composition. + +It's physically distinct. + +And I'll show you by examples, +but let's just get the + +definition down. + +It's physically distinct, and +in the extreme case-- + +so that means it's bounded. + +It's physically distinct. + +That's a fancy way of saying +that you can put a + +boundary around it. + +It's bounded. + +And then the other property that +it has, it's mechanically + +separable in the extreme. + +And so that's in the +case where you have + +a multi-phase system. + +You can point to the +different p. + +So what I'm going to +do, is I'm going to + +give you some examples. + +And so I'm going to let circle +p equal number of phases. + +I'll give you some examples. + +Why am I using circle p? + +Because just plain old p +is already pressure. + +So pressure, so this is kind of +a Western motif, you know? + +Like a Circle Bar Ranch +or something. + +So it's a p with a circle. + +That's my font. + +That's how I say number +of phases. + +So let's take a look +at some examples. + +So here's some examples +of p equals 1. + +So simple one is pure water. + +Pure H2O liquid. + +It has all of this. + +Wherever I have the water, all +right, here's some water, it's + +all of the same chemical +composition. + +It is physically distinct. + +I can put a boundary +around it. + +And in this case, there's +nothing to separate, because + +it's just a one-phase system. + +White gold. + +White gold is one phase. + +Because we have gold. + +Obviously we have gold. + +If you market something as white +gold, it has no gold, + +you'll go to prison. + +And how do we make white gold go +to its white color from the + +normal yellow? + +We add silver and +we add nickel. + +And these are all FCC metals, +and they substitute for one + +another on the lattice, and if +you sample anywhere in the + +white gold, you get +the same chemical + +composition, and so on. + +Air is an example of +a one-phase system. + +It's a gas, and in decreasing +order, we + +have nitrogen, oxygen. + +So it's a solution. + +We're breathing a solution. + +Nitrogen, oxygen, argon are +the main constituents. + +There's some CO2, some sulfur +dioxide if you live near a + +power plant, NOx if you're +near a tailpipe, and + +so on and so forth. + +And then the last one I'll +give as an example is + +calcia-zirconia. + +Or cubic zirconia. + +Let's just call it +cubic zirconia. + +The holidays are coming, +so we better get + +cubic zirconia up here. + +That's the poor man's diamond. + +Cubic zirconia, which consists +of a solid solution of calcium + +oxide in zirconium oxide. + +This is a solid solution, so +it's continuous and chemical + +composition identical. + +Now, contrast that with +two-phase system. + +So p equals 2 looks like this. + +So let's look at, instead of +simple water liquid, if I have + +ice cubes in water. + +So now I have two different +phases, and they're separated + +by state of matter. + +State of matter is +the issue here. + +Because I have a solid-- + +this is solid-- + +and I'm going to put the +boundary around them. + +The composition of the solid +is different from the + +composition of liquid. + +They're both the same water, +but you can tell it's a + +different crystal structure +and so on. + +And I can put boundaries +around, and it's + +mechanically separable. + +You can pull the ice cubes +out of the mix. + +Milk is two-phase. + +Milk has a fatty phase and +it has an aqueous phase. + +The aqueous phase contains +the minerals. + +That's why you can drink skim +milk and still get your + +calcium, because calcium, even +the general public knows + +calcium is a mineral. + +It's not elemental calcium, +it's a calcium compound. + +But it's ionic, it's soluble in +water, and the fat contains + +the other parts. + +You know from last day, this +is one of the lipids. + +And so you have fat globules +that are mechanically + +separable and distinct +from aqueous. + +So they actually have +a different chemical + +composition, different +type of bonding. + +Right? + +This is largely nonpolar, and +nonpolar doesn't like to + +dissolve in something that is +polar and hydrogen-bonded. + +So they phase separate. + +I've been saying phase +separate all along. + +Now you know what we mean +by phase separate. + +Here's a third one. + +This is really cool, because +you won't get this in any + +other chemistry class, +because only 3.091 + +talks about such things. + +David, can we cut to the +document camera? + +I want to show you a piece +of snowflake obsidian. + +Obsidian is a volcanic glass. + +So here's the piece +of obsidian. + +And what you're looking at is, +the black area is the glassy + +part, and the white is actually +some of the obsidian + +that has decided to devitrify. + +And it is turning crystalline. + +And so those are islands of +obsidian crystal sitting in a + +matrix of obsidian glass. + +If we go back to the-- + +I picked that up in +Yellowstone Park. + +It's fantastic. + +There's a wall, just a wall of +obsidian that comes down. + +And I think I've got +an image here. + +There it is. + +This one I pulled off +the internet. + +So this is crystalline +phase, and this is + +the amorphous phase. + +And the overall composition, +it's a glass, it's a silicate. + +And why isn't it transparent +to visible light? + +Because it's got iron in it. + +The iron gives it the absorption +and capabilities. + +The band gap is invisible, +so it's black. + +But then when this crystallizes, +it's got a + +different index, and +it's mainly SiO2. + +It's really the cristobalite +phase of the obsidian. + +So that's cool. + +So this is actually +differentiated on the basis of + +amorphous and crystalline of +something that's virtually the + +same chemical composition. + +So this could give you an idea +of what happens in the area of + +phase separation. + +OK. + +Now the second thing that +I have to bring to your + +attention, is that these phase +diagrams treat systems at + +equilibrium. + +They're stability maps, and +they treat systems at + +equilibrium. + +So what is equilibrium? + +Let's just get one time up +here a definition of + +equilibrium. + +Equilibrium is a condition which +there is no net reaction + +taking place. + +The system could be reacting. + +If you're looking at the ice +cubes in water, the ice could + +be dissolving, and some of the +water could be freezing, but + +overall, with time, there's +no net reaction. + +It's a dynamic system with +no net reaction. + +And it's characterized as +the lowest energy state. + +Systems strive towards +equilibrium. + +If it's the lowest energy state, +no net reaction then. + +If a system is truly at +equilibrium, the properties + +should be invariant +over time, because + +there's no net reaction. + +You can't prove equilibrium. + +You can only demonstrate the +absence of equilibrium. + +Because at equilibrium, there's +nothing, there's no + +net reaction. + +And it could be attainable +by multiple paths. + +So in other words, if I have ice +as the equilibrium phase, + +I can make it by freezing water, +and get to the same ice + +at the given temperature +and pressure. + +Or I could sublime. + +But if I specify the pressure +and the composition, I should + +always end up with +the same system. + +So attainable by +multiple paths. + +Because it's a stable +state, so it doesn't + +matter how you got there. + +It's a state function. + +And you know from your physics, +a state function has + +the same value, regardless +of how you arrived there. + +And then the last thing is, +I want to differentiate. + +See, these are all single phase, +but some of them are + +just one element, some of them +are just one compound, and + +some of them have a whole mix. + +So we have a way of quantifying +the degree of + +chemical complexity by using +the term called component. + +It's a measure of chemical +complexity. + +It's the number of chemically +distinguishable constituents. + +And again, these are +definitions. + +I'll give you some examples +so then the + +definition comes to life. + +I like to think of it as the +number of bottles you've got + +to pull off the shelf to +make the final product. + +The building blocks. + +So for example, water +is just water. + +You could say, but it's +hydrogen and oxygen. + +But if you take 560 or some +other thermal class, you'll + +learn that they're bound +by mole ratio. + +You don't have freedom of +hydrogen and oxygen. + +So it's just one bottle, whereas +to make white gold, + +you need three bottles. + +You need a bottle of gold, +a bottle of silver, + +and a bottle of nickel. + +So that's a three component +system. + +And I'm going to designate the +components by c with a + +circle around it. + +Because c without a circle +is already composition, + +concentration. + +OK. + +So now we can put all of this +together, and we'll show the + +difference between +multicomponent and multiphase. + +So we'll make a little table +here, and here I'm going to + +talk about one-phase systems, +and distinguish on the basis + +of components. + +So if it's single phase single +component, that's just water. + +One phase, one component. + +Simple liquid. + +If it's two components one +phase, that could be + +calcia-zirconia. + +I need a bottle of calcia and a +bottle of zirconia in order + +to make this two component +single-phase system. + +And then to have three +components, + +that's the white gold. + +It's still single phase, but I +need the gold, silver, and the + +nickel, whereas if I come over +here, I've got two phases. + +That could be slush. + +Slush, that's ice water. + +It's just one component. + +I just start with water, and +drop it down to 0 Centigrade, + +and I'm going to end up with +ice crystals in the water. + +So that's one component. + +I just needed one bottle. + +Literally, one bottle. + +All right. + +Now what about two components, +two phases? + +Well, we saw earlier when we +started thinking about + +solubility, we did the +bilayer with carbon + +tetrachloride and water. + +Remember, we dropped potassium +permanganate and iodine, and + +the potassium permanganate +dissolved in the water, and + +the iodine dissolved in the +carbon tetrachloride? + +Two different components. + +I need a bottle of carbon tet +and a bottle of water. + +And they'll phase separate. + +They don't dissolve in one +another, because this is a + +nonpolar liquid, and this is +polar hydrogen bonded. + +That's the origin of +phase separation. + +It's all about bonding, and +bonding is all about + +electronic structure, and that +sounds like a good topic for a + +class in chemistry. + +And then the last one +here is obsidian. + +The snowflake obsidian, +in which the + +components are SiO2-- + +so I'm going to have three +components and + +end up with two phases. + +SiO2, there's some magnesia, and +then the black comes from + +the magnetite. + +Fe304. + +So I've got three bottles off +the shelf, and I end up with + +something that is crystalline +and amorphous. + +So that's where I get +the two phases. + +Three components, two phases. + +It's great. + +So now I want to look at +some stability maps. + +And I'm going to start with the +simplest of all, which is + +the one we know best from human + +experience, and that's water. + +So we're going to look +at the one-- + +so it's a one component. + +So for water, we start with c +equals 1, and the example is + +going to be water. + +One component phase diagram. + +So we don't have a composition +axis, because the only thing + +we can vary is pressure +and temperature. + +If we change composition, +we've lost water. + +So it has to be axiomatically, +no variation composition. + +All we have is that +the coordinates of + +temperature and pressure. + +So there it is out of the book, +and I'm going to draw it + +a little bit differently, just +to emphasize three of my + +favorite words. + +Not to scale. + +Otherwise you can't see some +of the subtle features. + +So overall, it's a +y-shaped diagram. + +And this is pressure. + +Let's make it pressure +in atmospheres. + +Then our human experiences +is at 1 atmosphere. + +So at the highest temperatures, +we expect to + +have vapor, and at the lowest +temperatures, we expect solid. + +And in between, we +expect liquid. + +And then if we look at the 1 +atmosphere isobar, what's + +happening on this line? + +On the one side of line it's +liquid, and the other side of + +line, it's vapor. + +At this temperature, liquid +and vapor coexist. + +I call that the boiling point. + +So I'm going to put 100 here. + +And we already learned from our +little example of Mount + +Everest that this locust here, +this line, is the liquid + +equals vapor two phase +equilibrium. + +And you see how it changes? + +If I go to the top of Mount +Everest, the pressure is less + +than 1 atmosphere. + +which means the boiling point +of water is below the + +denaturing point. + +So this actually gives +you the map. + +Or if I put the pressure +cap on, I go up here. + +And you can use this in +the kitchen again. + +If you love wild rice, and you +can't wait 45 minutes when you + +get home, use a pressure +cooker. + +What the pressure cooker does, +is it allows you to have + +liquid up to 130 degrees +Celsius. + +See, you can't steam it. + +You've got to soak +it in water. + +And you know the +Arrhenius Law. + +If you can get the temperature +up by 30 degrees, you'll cut + +the cooking time in half. + +So how do you get water, +liquid, at 130 degrees? + +Then you can cook quicker! + +Pressure. + +Seal it. + +And then you've got liquid +water way, way up here. + +Now over here, this is +solid goes to liquid. + +So this is the freezing +point line. + +At 1 atmosphere, that's 0. + +0 Celsius. + +And you know, if you +go skating-- + +so let's say the ice +is minus 5 Celsius. + +And you're here, but you put +your weight on the blades, and + +the blades have small area. + +So pressure is force per area. + +So that puts you up here, and +now you cross, and now you + +glide on water. + +Film of water. + +You ever watch a hockey game? + +I grew up in Canada. + +We used to say, well, +the ice is fast. + +Why is the ice fast? + +Because you get down to +temperatures where you just + +get the right slickness +of water. + +If the ice is slow, the +temperature is so close that, + +you know, you get these big, +bruising hockey players, and + +they're moving up into +here, and it's + +like they're dragging. + +And if you ever come from +Minnesota or North Dakota, if + +you've ever skated when the +temperature gets down about + +minus 20, minus 30? + +It's a different experience, +because you never + +get across this line. + +Your blades are just, they +can't get a good grip. + +See? + +Everything you need +to know is here. + +This is four-star chef, this is + +prize-winning hockey player. + +We haven't got off the 1 +atmosphere line yet. + +OK. + +So now I'm going to say, this +is single phase, right? + +It's just vapor. + +This is single phase, and +this is single phase. + +It's all solid. + +And along this line, it's +two phase, isn't it? + +Solid-liquid. + +This is ice cubes, isn't it. + +Anywhere along this line +is ice cubes in water. + +Look at this one. + +This is liquid vapor. + +This is solid, liquid-- + +all three of them +coexist here. + +This is p equals 3, which means, +ice cubes floating in + +boiling water. + +And this happens at +only one point. + +It's called the triple point, +and its coordinates are-- + +this is not to scale. + +So this is 0.01 degrees +C. It's a + +1/100 of a degree higher. + +And the pressure here is 4.58 +millimeters of mercury, which + +then you can convert using +the 760 as 1 atmosphere. + +Oh, and this is solid-vapor. + +You can go directly from solid +to vapor down here. + +If you hang up your clothes on +a line and it's minus 20 + +degrees outside, first +thing that + +happens, the clothes freeze. + +You come back five +hours later, and + +the clothes are dry. + +Well, what happened? + +Did somebody take them in? + +Run them around the clothes +dryer, then + +hang them up for you? + +No. + +You're going directly from solid +to vapor, down in here. + +So here's the whole story +of the phase diagram. + +One last thing I want +to point out. + +Here, you're at a given +temperature and it's vapor. + +And then you squeeze, squeeze, +squeeze, and now things get + +closer together, and you go +from paper to liquid at + +constant temperature. + +That makes sense, right? + +I start from vapor, constant +temperature. + +I squeeze it, I get liquid, +I keep squeezing, + +I should make solid. + +Here's vapor. + +I squeeze, I get solid, +and I squeeze + +harder, and I get liquid. + +That makes no sense at all, +but that's what happens. + +What does this tell me? + +It tells me that the number of +nearest neighbors in the solid + +is greater than the vapor. + +Yeah, I get that. + +But the number of nearest +neighbors in the liquid must + +be greater than the +number of nearest + +neighbors in the solid. + +This is an exception. + +When I see this negative slope, +it means that ice cubes + +are going to float on water. + +That's what I learn from +this negative slope. + +So let's put that down. + +dp by dt when dp by dt +is less than zero. + +This is for solid +equals liquid. + +That means that the density of +the solid is less than the + +density of the liquid. + +All from here. + +OK. + +Good. + +So let's look at a few +other phase diagrams. + +I think I've got a few +things up here. + +Here's silicon. + +Pressure versus temperature. + +Its normal melting +point is about-- + +see, now I said normal +melting point. + +After today's lecture, if +somebody says, what's the + +boiling point of water? + +You don't go, 100 degrees. + +You say, at what pressure? + +And they go, oh, I hate you. + +I hated you before. + +I'm going to use +an adverb here. + +Now I really hate you. + +OK. + +So this is the normal melting +point of silicon. + +It's about 1430 degrees +Centigrade, or a 1700 + +something Kelvin. + +And it also has this +negative slope. + +And what does that tell you? + +That liquid silicon is denser +than solid silicon, and it's a + +good thing it is, because +we wouldn't have the + +microelectronics age if +it weren't for that. + +We couldn't have Teukolsky +crystal growth and everything + +else that makes silicon +dirt cheap. + +You know why it's dirt cheap? + +Because it's made from dirt. + +That's why it's dirt cheap. + +It's true. + +Here's aluminum. + +This is normal. + +This is the normal solid-liquid +equilibrium. + +This is FCC metal, which +is the closest packed. + +Axiomatically, the liquid must +be less well-packed. + +All right? + +So this is dog bites man, +this is man bites dog. + +This is the unusual one. + +OK. + +What else do we have? + +Nitrogen! + +Here's nitrogen. + +I drew this. + +So there's the 1 atmosphere +line. + +Nitrogen boils at 77 +Kelvin, and it + +freezes at about 63 Kelvin. + +And it's got the positive slope +that you'd expect, and + +so solid nitrogen is denser +then liquid nitrogen. + +And you can remember +77 Kelvin. + +You want to remember a +few of these things. + +I wanted to point out to +you that at atmospheric + +temperature, ambient +temperature, you + +can remember 20-20. + +20-20 vision. + +So at 20 degrees C, it's roughly +20 millimeters of + +mercury, is the vapor +pressure of water. + +It's not exactly true, but +it's close enough. + +I think it's really 24. + +But 20-20 is nice to know. + +And what's the street +address for MIT? + +77 Mass Ave. That's the boiling +point of liquid + +nitrogen, 77 Kelvin. + +So I thought we'd do +a few things here. + +And I'm going to show you a +little bit of fun and games + +with liquid nitrogen. + +But first, I've been instructed +I have to practice + +safe laboratory-- + +So I'm going to put +on my lab coat. + +Yes. + +It's a nice lab coat. + +Mm-hm! + +Yeah, look. + +You want to know-- + +let's go back to this. + +They have to know where +the-- this is not + +just any old lab coat. + +This is a nice lab coat. + +This is from France. + +It's from MAISON DUTECH. + +See? + +Notice the collar. + +It's not that typical, +you know. + +MAISON DUTECH. + +OK. + +Let's go back to the +phase diagram. + +So Dave Broderick is going +to help us here. + +So we're going to +have some fun. + +I'm going to put on +a face shield so + +I don't blind myself. + +All right. + +Here we go. + +All right. + +So let's get some +liquid nitrogen. + +Sounds different, huh? + +Sounds terrible for me. + +All right. + +So we've got some liquid +nitrogen here, and I'll pour + +it into a Dewar. + +So what happens when you wet a +sheet of paper with ink with + +liquid nitrogen? + +What kind of bonding is there +in liquid nitrogen? + +Look. + +No running, no running. + +If it's liquid nitrogen. + +I tell you, everything you +learn here is so valuable + +compared all the other stuff +you learn here-- + +All right. + +So there's a couple of things. + +So let's look at glass +transition temperature. + +So this is a latex glove. + +You can see it's above its glass +transition temperature, + +and the cross-links are +snapping it back. + +What I'm going to do, is take +it down below its glass + +transition temperature, and turn +it glassy and brittle. + +So that it's below the TG. + +Here's some paraffin. + +Paraffin, which is also +a polymer here. + +Take the paper off. + +OK. + +So here's paraffin. + +Look. + +Look at the van der +Waals bond. + +All right? + +This is van der Waals bond. + +Now we're going to +go below the TG. + +It's liquid nitrogen! + +It doesn't matter. + +OK, you can hear it already. + +So it's now below the glass +transition temperature. + +So what else have we got? + +Oh, you've heard of the glass +flowers at Harvard? + +Well, we've got glass +flowers here, so. + +Here's a rose. + +See, in the proteins, you know, +it's above the-- you + +know, it's soft. + +But now, we're going +to put the-- + +mm-hm. + +Here we go. + +You ready? + +Oh, come on. + +It's not a kitten. + +What's the matter? + +It's still burbling here. + +We have to wait until +it's dead. + +This is for science. + +OK. + +Now it's below its glass +transition temperature. + +Oh, I'm sorry, David. + +I should put this over +on the other side. + +But maybe it's the red, +or maybe it's + +because it's a rose. + +So here's the chrysanthemum. + +Today is your day. + +Let's go. + +Get this thing moving! + +Yeah. + +So there you have it. + +There you have it. + +I think that's-- + +oh, there's one, may we +go back to the slide? + +Better put the gloves +on for this. + +I'll have to write +apology letters. + +OK. + +So we're going to do next, is +we're going to look at phase + +equilibriums. + +There's the melting points and +boiling point of oxygen, + +argon, and nitrogen. + +And what you notice is that +nitrogen boils at a lower + +temperature then oxygen +and argon. + +So what I'm going to do, is I'm +going to pour some liquid + +nitrogen into this beaker. + +And then inside the graduated +cylinder, I'm going to let it + +sit here, and we're going +to condense air. + +And the result will be that +we're going to start + +condensing liquid oxygen, and +they'll be little bits of + +argon ice floating +in liquid oxygen. + +And liquid oxygen is faintly +blue, and it's paramagnetic, + +as you know, because it's got +the unpaired electrons, which + +means that it will levitate +in a magnetic field. + +I couldn't bring a big magnet +in here, but we'll see if we + +can make some blue stuff. + +And it's foaming, because this +would be like pouring water + +into something that's-- + +I don't know. + +300 degrees Centigrade. + +But eventually, the heat +transfer gets low enough that + +you have stability here, and-- + +yeah. + +OK. + +Oh, that's terrific. + +OK. + +What else have we got? + +Let's go back to the slide. + +God, I hate this thing. + +OK. + +So you've been looking +at that nitrogen. + +Let's look at what's next. + +Ah. + +Now if you solidify nitrogen +here, you get a whole bunch of + +different polymorphs. + +Different crystal structures. + +So there are about five or six +different crystallographic + +forms of solid nitrogen. + +For that, we'd have to +bring liquid helium. + +4.2 Kelvin. + +Very cool stuff. + +Here's carbon dioxide. + +Now, it also has the positive +slope, so solid + +will sink in liquid. + +But look, the interesting +point here. + +The triple point is +5 atmospheres. + +At atmospheric pressure, you go +directly from solid to gas. + +It sublimes. + +And that's advantageous. + +When we use carbon dioxide as +a coolant, when it gives up + +its enthalpy to cool, it doesn't +then turn into liquid. + +If you chill something with ice, +with water ice, when it + +gives up its enthalpy, +the object is + +now swimming in water. + +And that's no good. + +So hence we have the term dry +ice, because we go directly + +from solid to vapor. + +And we want to prove this. + +So what we've got here is +a big block of dry ice. + +So this is at minus 78 degrees +Celsius, and it's + +still stable here. + +Well, it's subliming +before your eyes. + +It's smaller than it was when +we started the lecture. + +So what I'm going to do now-- + +oh, I'm not wearing +that stuff. + +I guess I'd better. + +They're going to write +me up on some log, + +teaching you bad practice. + +But anyways. + +All right. + +So what we're going to do, is +we're going to test the + +proposal that this actually +goes-- so I've got some water. + +Here, David, let's go +out to the video. + +So let's take some water. + +I think we got water +from France. + +Goes with the lab coat. + +This is Evian, OK? + +So I pour the Evian into +the Florence flask. + +This is Florence. + +Florence is round, and the +Erlenmeyer is the flat one. + +So let's move this guy. + +You're going in the backstage +for a while. + +You just keep + +condensing All right. + +So now, this is here. + +Now what we're going to do, is +we're going to put some dry + +ice in there, and see +if we go directly + +from solid to a vapor. + +Take a chip off the +old block, here. + +OK. + +So now you can see that +it's going directly + +from solid to vapor. + +So that's carbon dioxide +bubbles. + +And we assume that the phase +diagrams is correct. + +I mean, another thing +we could do, is-- + +I mean, I know what club +soda tastes like. + +I could just test it, right? + +Yeah. + +It's carbon dioxide. + +Now! + +Here's the other thing. + +You know, Schweppes likes to +pride itself on tiny bubbles. + +They have a tagline, +Tiny Bubbles. + +Right? + +So here's Schweppes. + +And you can see Schweppes, +with their + +wimpy little tiny bubbles. + +Can you get that, David? + +But we have, we have +big bubbles. + +I mean, this is pure. + +You can't get any better +than that. + +I got Evian water, and I got +a block of carbon dioxide. + +I like making my own +carbonated water. + +I've taken it to a new level. + +OK. + +What else do we have? + +Well, let's see if we made +any liquid oxygen here. + +Try this. + +I don't know if we got +anything here. + +Oh yeah! + +Oh, wow. + +Look. + +OK. + +So that liquid in there-- +oh, I see. + +You've got a separate thing. + +I don't know if you can see. + +It's condensing. + +That liquid in there, that's +liquid oxygen. + +I won't drink this. + +But I can inhale it. + +Pure oxygen. + +I could have a cigarette, +and just put the + +cigarette in there. + +What happens if I put the lit +cigarette into the oxygen? + +All that happens is that it +burns quickly, that's all. + +There's no explosion. + +It burns quickly. + +If you walk into a room full of +oxygen, all that happens is + +you'll singe your nose, +that's all. + +There's no explosion. + +It's just oxygen. + +There's no fuel. + +The fuel is just in tobacco, +and there's not much. + +It's not a problem. + +A room full of oxygen? + +Pfft! + +OK. + +Let's go back to the slides. + +What have we got here? + +We've got some examples of +other phase diagrams. + +All right. + +Yeah. + +[MUSIC PLAYBACK: FROM 'PHANTOM +OF THE OPERA'] + +PROFESSOR: Actually, +it's quite tasty. + +All right. + +So. + +Now, here's zirconia. + +Now, here's the thing to +know about zirconia. + +Look at all the different +phases. + +And cubic zirconia is the one +that has a high index of + +refraction, but it's stable only +at temperatures exceeding + +2000 degrees C. So +that's no good. + +So what I'm going to show you +next day is that by changing + +the composition, and adding +calcium oxide, we open up this + +zone here that's labeled cubic, +and we get it stable + +all the way down to +room temperature. + +It's an example of changing +composition to get the + +stability of a phase +that we want. + +This is carbon. + +So down here, the normal form, +as we've learned earlier, the + +normal form is graphite. + +Diamond is formed at elevated +temperatures and pressures. + +And this is liquid carbon. + +All right? + +Now, to make artificial diamond, +you can try putting + +graphite in an anvil, and +squeezing, and squeezing, and + +squeezing, and coming +up into here. + +And then it becomes metastable, +and then maybe, + +because the activation energy +to jump from that sp3 + +hybridized state to sp2 is so +high, the diamond is stable. + +So you don't have to go running +home to see if your + +diamond studs are now turning +into graphite. + +They won't. + +Once you get into this +zone, they'll stay. + +The activation energy +is too high. + +You need more than 1/40 eV +to do it, is necessary. + +But in the 1950s, General +Electric, its Schenectady + +research labs, reasoned that +because carbon is so soluble + +in iron, they could dissolve +carbon in liquid iron, and + +then raise the pressure and +temperature, and then change + +to exsolve and cause carbon +to precipitate + +out of molten iron. + +That's the birth of artificial +diamond. + +That's how they did it. + +Using this concept, but then +dissolving it in molten iron. + +[MUSIC PLAYBACK: 'DIAMONDS ARE +A GIRL'S BEST FRIEND'] + +PROFESSOR: I don't know +how that got in there. + +All right. + +Here's one for mercury. + +I looked it up, using the tools +that you've been taught + +here in 3.091. + +So this is a paper phase +diagram for mercury. + +And physicists drive me nuts, +because they plot temperature + +versus pressure. + +I want pressure versus +temperature. + +So I just turned it around. + +And so here's the liquid line. + +So you know that liquid mercury +is going to float on + +solid mercury, and there's a +plurality of solid phases. + +And these are all different +crystal structures. + +Now I've got a treat for you. + +I was in Barcelona several +years ago, and I saw the + +mercury fountain that was made +by Joan Miro in collaboration + +with Calder. + +Calder has the big sail outside +of East Campus. + +So Calder collaborated +with Miro, back in + +the '30s and '40s. + +And this is in honor of the +miners of Almaden, where there + +are cinnabar mines. + +And the miners fought bravely +against the Fascist forces of + +Franco, and Miro wanted +to honor them. + +So here's their museum. + +It's a beautiful place +up on top of an + +escarpment over Barcelona. + +And what I'm going to show you +is a mercury fountain. + +[MUSIC PLAYBACK] + +This is liquid mercury. + +The speed has not +been altered. + +This is a liquid at room +temperature, density 13.5, + +metallic bonds. + +Look at it. + +Very high surface tension. + +Look at the way it shimmers. + +Look at this shot. + +This has not been altered. + +That's the way it pours +into gravity field. + +It's really fantastic. + +And of course, mercury vapor +is toxic, so the + +whole thing is in a-- + +[END MUSIC PLAYBACK] + +PROFESSOR: Oh, that's the-- + +I cut that snippet out +of the documentary. + +OK, we don't want to see that. + +So they have the whole +thing inside of a + +polymethylmethacrylate cage, to +keep the mercury vapor from + +affecting the people that +work in the museum. + +Here are some phase diagrams +from hell. + +This is bismuth. + +And look at bismuth. + +Bismuth is like water, +and like silicon. + +So the solid is less dense +than the liquid. + +But look at all of these +different phases. + +Here's sulfur. + +Sulfur is crazy. + +Look, phases in the solid phase, +there's even phases in + +the liquid! + +Different phases. + +They're allotropes. + +Here's sulfur. + +Elemental sulfur, the disulfide, +hexasulfide. + +It makes rings, it makes +long chains. + +And these are called +allotropes. + +They're different forms +of the same element. + +So oxygen is O. There's +the diatomic molecule. + +And the triatomic molecule, +which is ozone, these are all + +allotropes of oxygen. + +What else do we have? + +OK. + +This is polymorphs. + +So this is alpha goes to beta. + +See, different crystal +structures. + +You could see with your naked +eye what's going on here. + +Different crystal structures. + +And then this goes to lambda, +and then finally, they're + +pouring here. + +And if you get a very high +cooling rate, and you've got + +those long chains, +what happens? + +You don't form the crystal. + +You form the amorphous form. + +So they'll call this forming +plastic sulfur. + +We know better. + +It's amorphous sulfur. + +It's not plastic sulfur. + +Here's water, a complete +diagram. + +Now, this is in kilobars. + +So there's all the different +phases of water. + +There's the negative line. + +That's the thing here. + +But at very, very high. + +Look at all the different +phases of water. + +And they have numbers on them. + +If you read Kurt Vonnegut's +Cat's + +Cradle, there's ice nine. + +You get that going, it freezes +the whole world, right? + +But here's, I draw your +attention on this one. + +You see this point here? + +This is ice seven. + +At 100 degrees C, it's solid. + +You need 25 kilobars. + +So we could go over to the lab, +take some water, put 25 + +kilobars on it, make solid +ice at 100 degrees C. + +And it'll be stable. + +Look! + +This is minus 78. + +It's been here for +a long time. + +So now I come into a cocktail +party with this, I drop this + +ice cube into a glass of aqueous +beverage, it sinks to + +the bottom, and the beverage +heats up to the boiling point. + +That's what this +is telling you! + +That'll get you popularity +instantly. + +How did you do that? + +How did you do that? + +And up here is the supercritical +fluid, the last + +thing we haven't said +anything about. + +Look. + +If you take a gas, and you +keep squeezing it and + +squeezing it, eventually the gas +molecules are close enough + +together that they're +indistinguishable from the + +liquid phase. + +Or if you start here, with the +liquid, and you keep raising + +the temperature, the density +goes lower and lower until the + +molecules are far enough apart +that you can't tell this zone, + +whether it's a rarefied liquid +or a highly compressed gas. + +The properties criss-cross. + +This is supercritical. + +It has liquid-like transport +properties, and vapor-like + +chemical properties. + +So you can end up doing things +that are very, very different. + +Now, I'm going to give you an +example of decaffeinating + +coffee by taking the coffee, +going up into the + +supercritical regime, which +allows you to extract the + +caffeine, and not +brew the coffee. + +So you want to just get the-- +well, if you just heat it up, + +you'll make the coffee. + +So here's an example. + +It's called solvent +extraction. + +Historically, this solvent was +methylene chloride, which is + +also used as paint stripper. + +We don't do that anymore +to coffee. + +They did in the '60s! + +They did. + +They also used +trichloroethylene. + +It works really well to leech +out the caffeine. + +How much is left in there for +you to taste in your coffee? + +I don't know. + +Maybe that's why people were +so excited in the '60s to + +drink their decaffeinated +Sanka. + +I don't know. + +But anyway, so you take the +green beans in carbon dioxide + +as supercritical, and drop the +caffeine level, and then you + +play with temperature and +pressure to go over the KSP. + +The caffeine salts out, and +then you recycle the CO2. + +OK. + +I hope I've given you some + +introduction to phase diagrams. + +And we'll see you on Monday. \ No newline at end of file diff --git a/xdewLsXI_UQ.txt b/xdewLsXI_UQ.txt new file mode 100644 index 0000000000000000000000000000000000000000..942c147703b93eaca4bde4318bb6c5a740482515 --- /dev/null +++ b/xdewLsXI_UQ.txt @@ -0,0 +1,1067 @@ +align:start position:0% + +we now study a model that involves the + + align:start position:0% +we now study a model that involves the + + + align:start position:0% +we now study a model that involves the +sum of independent random variables but + + align:start position:0% +sum of independent random variables but + + + align:start position:0% +sum of independent random variables but +with a twist it's going to be the sum of + + align:start position:0% +with a twist it's going to be the sum of + + + align:start position:0% +with a twist it's going to be the sum of +a random number of independent random + + align:start position:0% +a random number of independent random + + + align:start position:0% +a random number of independent random +variables as opposed to a fixed number + + align:start position:0% +variables as opposed to a fixed number + + + align:start position:0% +variables as opposed to a fixed number +this is a model that shows up in a + + align:start position:0% +this is a model that shows up in a + + + align:start position:0% +this is a model that shows up in a +variety of applications but it will also + + align:start position:0% +variety of applications but it will also + + + align:start position:0% +variety of applications but it will also +help us fine tune our command of the law + + align:start position:0% +help us fine tune our command of the law + + + align:start position:0% +help us fine tune our command of the law +of iterated expectations and the law of + + align:start position:0% +of iterated expectations and the law of + + + align:start position:0% +of iterated expectations and the law of +total variance the story goes as follows + + align:start position:0% +total variance the story goes as follows + + + align:start position:0% +total variance the story goes as follows +you go shopping and you visit a number + + align:start position:0% +you go shopping and you visit a number + + + align:start position:0% +you go shopping and you visit a number +of stores except that the number of + + align:start position:0% +of stores except that the number of + + + align:start position:0% +of stores except that the number of +stores that you will visit is itself a + + align:start position:0% +stores that you will visit is itself a + + + align:start position:0% +stores that you will visit is itself a +random variable at each one of the + + align:start position:0% +random variable at each one of the + + + align:start position:0% +random variable at each one of the +stores you spend a certain amount of + + align:start position:0% +stores you spend a certain amount of + + + align:start position:0% +stores you spend a certain amount of +money we denoted by X I and we make the + + align:start position:0% +money we denoted by X I and we make the + + + align:start position:0% +money we denoted by X I and we make the +assumption that the x i's are drawn from + + align:start position:0% +assumption that the x i's are drawn from + + + align:start position:0% +assumption that the x i's are drawn from +a certain distribution they're + + align:start position:0% +a certain distribution they're + + + align:start position:0% +a certain distribution they're +identically distributed and they're + + align:start position:0% +identically distributed and they're + + + align:start position:0% +identically distributed and they're +independent of each other + + align:start position:0% +independent of each other + + + align:start position:0% +independent of each other +we also make the assumption that the x + + align:start position:0% +we also make the assumption that the x + + + align:start position:0% +we also make the assumption that the x +i's are independent of capital and this + + align:start position:0% +i's are independent of capital and this + + + align:start position:0% +i's are independent of capital and this +means that no matter how many stores you + + align:start position:0% +means that no matter how many stores you + + + align:start position:0% +means that no matter how many stores you +visit the X I the amount of money you + + align:start position:0% +visit the X I the amount of money you + + + align:start position:0% +visit the X I the amount of money you +spend in each one of the stores that you + + align:start position:0% +spend in each one of the stores that you + + + align:start position:0% +spend in each one of the stores that you +visit is a random variable that's drawn + + align:start position:0% +visit is a random variable that's drawn + + + align:start position:0% +visit is a random variable that's drawn +from a common distribution which does + + align:start position:0% +from a common distribution which does + + + align:start position:0% +from a common distribution which does +not change no matter what capital n is + + align:start position:0% +not change no matter what capital n is + + + align:start position:0% +not change no matter what capital n is +with these assumptions in place let us + + align:start position:0% +with these assumptions in place let us + + + align:start position:0% +with these assumptions in place let us +now focus on the total amount of money + + align:start position:0% +now focus on the total amount of money + + + align:start position:0% +now focus on the total amount of money +that you are spending this is the sum of + + align:start position:0% +that you are spending this is the sum of + + + align:start position:0% +that you are spending this is the sum of +random variables but with the extra + + align:start position:0% +random variables but with the extra + + + align:start position:0% +random variables but with the extra +twist that the index goes up to capital + + align:start position:0% +twist that the index goes up to capital + + + align:start position:0% +twist that the index goes up to capital +n which is itself a random variable how + + align:start position:0% +n which is itself a random variable how + + + align:start position:0% +n which is itself a random variable how +do we deal with this situation + + align:start position:0% +do we deal with this situation + + + align:start position:0% +do we deal with this situation +one approach that's always worth trying + + align:start position:0% +one approach that's always worth trying + + + align:start position:0% +one approach that's always worth trying +when faced with a complicated problem is + + align:start position:0% +when faced with a complicated problem is + + + align:start position:0% +when faced with a complicated problem is +to try to condition on some information + + align:start position:0% +to try to condition on some information + + + align:start position:0% +to try to condition on some information +that will make the problem easier in + + align:start position:0% +that will make the problem easier in + + + align:start position:0% +that will make the problem easier in +this case we can condition on the value + + align:start position:0% +this case we can condition on the value + + + align:start position:0% +this case we can condition on the value +of capital n taking a fixed specific + + align:start position:0% +of capital n taking a fixed specific + + + align:start position:0% +of capital n taking a fixed specific +value because in that case we will be + + align:start position:0% +value because in that case we will be + + + align:start position:0% +value because in that case we will be +dealing with the sum of a finite number + + align:start position:0% +dealing with the sum of a finite number + + + align:start position:0% +dealing with the sum of a finite number +of random variables where that number is + + align:start position:0% +of random variables where that number is + + + align:start position:0% +of random variables where that number is +a fixed specific number and this is a + + align:start position:0% +a fixed specific number and this is a + + + align:start position:0% +a fixed specific number and this is a +situation we have encountered before and + + align:start position:0% +situation we have encountered before and + + + align:start position:0% +situation we have encountered before and +know how to deal with it + + align:start position:0% +know how to deal with it + + + align:start position:0% +know how to deal with it +so let us get started let us calculate + + align:start position:0% +so let us get started let us calculate + + + align:start position:0% +so let us get started let us calculate +the expected value of y if we condition + + align:start position:0% +the expected value of y if we condition + + + align:start position:0% +the expected value of y if we condition +on the number of stars let's say for + + align:start position:0% +on the number of stars let's say for + + + align:start position:0% +on the number of stars let's say for +example someone tells us that we visited + + align:start position:0% +example someone tells us that we visited + + + align:start position:0% +example someone tells us that we visited +five stars then the expected value of y + + align:start position:0% +five stars then the expected value of y + + + align:start position:0% +five stars then the expected value of y +is going to be the expected value of the + + align:start position:0% +is going to be the expected value of the + + + align:start position:0% +is going to be the expected value of the +sum of the amount of money you spend in + + align:start position:0% +sum of the amount of money you spend in + + + align:start position:0% +sum of the amount of money you spend in +each one of those five stores in our + + align:start position:0% +each one of those five stores in our + + + align:start position:0% +each one of those five stores in our +instance it's that random variable + + align:start position:0% +instance it's that random variable + + + align:start position:0% +instance it's that random variable +capital n but since I told you that + + align:start position:0% +capital n but since I told you that + + + align:start position:0% +capital n but since I told you that +capital n takes a specific numerical + + align:start position:0% +capital n takes a specific numerical + + + align:start position:0% +capital n takes a specific numerical +value this means that this instance of + + align:start position:0% +value this means that this instance of + + + align:start position:0% +value this means that this instance of +capital n in the index of the summation + + align:start position:0% +capital n in the index of the summation + + + align:start position:0% +capital n in the index of the summation +can be replaced by little n if I tell + + align:start position:0% +can be replaced by little n if I tell + + + align:start position:0% +can be replaced by little n if I tell +you that capital n is equal to little n + + align:start position:0% +you that capital n is equal to little n + + + align:start position:0% +you that capital n is equal to little n +then this number here capital n becomes + + align:start position:0% +then this number here capital n becomes + + + align:start position:0% +then this number here capital n becomes +the same as little n here we use now the + + align:start position:0% +the same as little n here we use now the + + + align:start position:0% +the same as little n here we use now the +assumption that capital n is independent + + align:start position:0% +assumption that capital n is independent + + + align:start position:0% +assumption that capital n is independent +from the excise here we have the sum of + + align:start position:0% +from the excise here we have the sum of + + + align:start position:0% +from the excise here we have the sum of +a fixed number of random variables all + + align:start position:0% +a fixed number of random variables all + + + align:start position:0% +a fixed number of random variables all +of them are independent of capital n if + + align:start position:0% +of them are independent of capital n if + + + align:start position:0% +of them are independent of capital n if +I give you some information on capital n + + align:start position:0% +I give you some information on capital n + + + align:start position:0% +I give you some information on capital n +this does not change the distribution of + + align:start position:0% +this does not change the distribution of + + + align:start position:0% +this does not change the distribution of +the x i's so the conditioning does not + + align:start position:0% +the x i's so the conditioning does not + + + align:start position:0% +the x i's so the conditioning does not +affect the answer the conditional + + align:start position:0% +affect the answer the conditional + + + align:start position:0% +affect the answer the conditional +expectation is going to be the same as + + align:start position:0% +expectation is going to be the same as + + + align:start position:0% +expectation is going to be the same as +the unconditional expectation and now we + + align:start position:0% +the unconditional expectation and now we + + + align:start position:0% +the unconditional expectation and now we +have the expected value of a sum of + + align:start position:0% +have the expected value of a sum of + + + align:start position:0% +have the expected value of a sum of +random variables each one of them has a + + align:start position:0% +random variables each one of them has a + + + align:start position:0% +random variables each one of them has a +common expectation let's denote it with + + align:start position:0% +common expectation let's denote it with + + + align:start position:0% +common expectation let's denote it with +this notation this is the common + + align:start position:0% +this notation this is the common + + + align:start position:0% +this notation this is the common +expected value of all the x i's and + + align:start position:0% +expected value of all the x i's and + + + align:start position:0% +expected value of all the x i's and +we're adding n of them so we obtain n + + align:start position:0% +we're adding n of them so we obtain n + + + align:start position:0% +we're adding n of them so we obtain n +times this expectation now let us apply + + align:start position:0% +times this expectation now let us apply + + + align:start position:0% +times this expectation now let us apply +the total expectation theorem do we take + + align:start position:0% +the total expectation theorem do we take + + + align:start position:0% +the total expectation theorem do we take +the familiar form of the total + + align:start position:0% +the familiar form of the total + + + align:start position:0% +the familiar form of the total +expectation theorem and in here we can + + align:start position:0% +expectation theorem and in here we can + + + align:start position:0% +expectation theorem and in here we can +plug in the expression that we have just + + align:start position:0% +plug in the expression that we have just + + + align:start position:0% +plug in the expression that we have just +found which is n times expected value of + + align:start position:0% +found which is n times expected value of + + + align:start position:0% +found which is n times expected value of +x now the expected value of x is just a + + align:start position:0% +x now the expected value of x is just a + + + align:start position:0% +x now the expected value of x is just a +number and then we have this summation + + align:start position:0% +number and then we have this summation + + + align:start position:0% +number and then we have this summation +here which we recognize to be just the + + align:start position:0% +here which we recognize to be just the + + + align:start position:0% +here which we recognize to be just the +definition of the expected value of N + + align:start position:0% +definition of the expected value of N + + + align:start position:0% +definition of the expected value of N +and so we come to the conclusion that + + align:start position:0% +and so we come to the conclusion that + + + align:start position:0% +and so we come to the conclusion that +the expected amount of money that you + + align:start position:0% +the expected amount of money that you + + + align:start position:0% +the expected amount of money that you +will be spending is equal to the + + align:start position:0% +will be spending is equal to the + + + align:start position:0% +will be spending is equal to the +following product the expected number of + + align:start position:0% +following product the expected number of + + + align:start position:0% +following product the expected number of +stores that you visit times the expected + + align:start position:0% +stores that you visit times the expected + + + align:start position:0% +stores that you visit times the expected +amount of money that you will be + + align:start position:0% +amount of money that you will be + + + align:start position:0% +amount of money that you will be +spending at each store this is a quite + + align:start position:0% +spending at each store this is a quite + + + align:start position:0% +spending at each store this is a quite +plausible answer it makes sense on the + + align:start position:0% +plausible answer it makes sense on the + + + align:start position:0% +plausible answer it makes sense on the +average the amount of money you spend is + + align:start position:0% +average the amount of money you spend is + + + align:start position:0% +average the amount of money you spend is +equal to the average number of stores + + align:start position:0% +equal to the average number of stores + + + align:start position:0% +equal to the average number of stores +times the average amount of money in + + align:start position:0% +times the average amount of money in + + + align:start position:0% +times the average amount of money in +each store so it is intuitively what you + + align:start position:0% +each store so it is intuitively what you + + + align:start position:0% +each store so it is intuitively what you +might expect on the other hand we know + + align:start position:0% +might expect on the other hand we know + + + align:start position:0% +might expect on the other hand we know +that reasoning on the average does not + + align:start position:0% +that reasoning on the average does not + + + align:start position:0% +that reasoning on the average does not +always give us the right answers so it's + + align:start position:0% +always give us the right answers so it's + + + align:start position:0% +always give us the right answers so it's +important to corroborate this particular + + align:start position:0% +important to corroborate this particular + + + align:start position:0% +important to corroborate this particular +formula by working out a mathematical + + align:start position:0% +formula by working out a mathematical + + + align:start position:0% +formula by working out a mathematical +derivation now let us carry out the + + align:start position:0% +derivation now let us carry out the + + + align:start position:0% +derivation now let us carry out the +second mathematical derivation using the + + align:start position:0% +second mathematical derivation using the + + + align:start position:0% +second mathematical derivation using the +law of iterated expectations to use the + + align:start position:0% +law of iterated expectations to use the + + + align:start position:0% +law of iterated expectations to use the +law of iterated expectations we need to + + align:start position:0% +law of iterated expectations we need to + + + align:start position:0% +law of iterated expectations we need to +put our hands on this random variable + + align:start position:0% +put our hands on this random variable + + + align:start position:0% +put our hands on this random variable +the abstract conditional expectation + + align:start position:0% +the abstract conditional expectation + + + align:start position:0% +the abstract conditional expectation +what is this object it's a random + + align:start position:0% +what is this object it's a random + + + align:start position:0% +what is this object it's a random +variable that takes this value whenever + + align:start position:0% +variable that takes this value whenever + + + align:start position:0% +variable that takes this value whenever +capital n is equal to little n so it's + + align:start position:0% +capital n is equal to little n so it's + + + align:start position:0% +capital n is equal to little n so it's +an object that takes this value whenever + + align:start position:0% +an object that takes this value whenever + + + align:start position:0% +an object that takes this value whenever +capital n is equal to little n but that + + align:start position:0% +capital n is equal to little n but that + + + align:start position:0% +capital n is equal to little n but that +object is the same as this random + + align:start position:0% +object is the same as this random + + + align:start position:0% +object is the same as this random +variable because this is the random + + align:start position:0% +variable because this is the random + + + align:start position:0% +variable because this is the random +variable that takes the value here when + + align:start position:0% +variable that takes the value here when + + + align:start position:0% +variable that takes the value here when +capital n is equal to little n therefore + + align:start position:0% +capital n is equal to little n therefore + + + align:start position:0% +capital n is equal to little n therefore +the abstract conditional expectation + + align:start position:0% +the abstract conditional expectation + + + align:start position:0% +the abstract conditional expectation +takes this particular form here which we + + align:start position:0% +takes this particular form here which we + + + align:start position:0% +takes this particular form here which we +can substitute inside this expectation + + align:start position:0% +can substitute inside this expectation + + + align:start position:0% +can substitute inside this expectation +here and now notice that the expected + + align:start position:0% +here and now notice that the expected + + + align:start position:0% +here and now notice that the expected +value of X is a constant so it can be + + align:start position:0% +value of X is a constant so it can be + + + align:start position:0% +value of X is a constant so it can be +pulled outside this expectation and + + align:start position:0% +pulled outside this expectation and + + + align:start position:0% +pulled outside this expectation and +we're left with the product of the + + align:start position:0% +we're left with the product of the + + + align:start position:0% +we're left with the product of the +expected value of n times the expected + + align:start position:0% +expected value of n times the expected + + + align:start position:0% +expected value of n times the expected +value of X so this completes the + + align:start position:0% +value of X so this completes the + + + align:start position:0% +value of X so this completes the +derivation of the expected value of the + + align:start position:0% +derivation of the expected value of the + + + align:start position:0% +derivation of the expected value of the +sum of a random number of random + + align:start position:0% +sum of a random number of random + + + align:start position:0% +sum of a random number of random +variables \ No newline at end of file diff --git a/yBOmyxg0sVM.txt b/yBOmyxg0sVM.txt new file mode 100644 index 0000000000000000000000000000000000000000..f77d764eb353c5e4022750feeb2b4e349fce1ee4 --- /dev/null +++ b/yBOmyxg0sVM.txt @@ -0,0 +1,16323 @@ +align:start position:0% + +Let's uh let's start a so first the + + align:start position:0% +Let's uh let's start a so first the + + + align:start position:0% +Let's uh let's start a so first the +homework assignment is out as I + + align:start position:0% +homework assignment is out as I + + + align:start position:0% +homework assignment is out as I +said uh it's due right before + + align:start position:0% +said uh it's due right before + + + align:start position:0% +said uh it's due right before +Thanksgiving if anybody needs an + + align:start position:0% +Thanksgiving if anybody needs an + + + align:start position:0% +Thanksgiving if anybody needs an +extension just let me + + align:start position:0% +extension just let me + + + align:start position:0% +extension just let me +know a and + + align:start position:0% +know a and + + + align:start position:0% +know a and +uh the instructions are on the on the + + align:start position:0% +uh the instructions are on the on the + + + align:start position:0% +uh the instructions are on the on the +site essentially uh each one should + + align:start position:0% +site essentially uh each one should + + + align:start position:0% +site essentially uh each one should +write like their own solution to make + + align:start position:0% +write like their own solution to make + + + align:start position:0% +write like their own solution to make +sure you understand it's okay if you + + align:start position:0% +sure you understand it's okay if you + + + align:start position:0% +sure you understand it's okay if you +talk among one among one another as long + + align:start position:0% +talk among one among one another as long + + + align:start position:0% +talk among one among one another as long +as it's fruitful and please type it up + + align:start position:0% +as it's fruitful and please type it up + + + align:start position:0% +as it's fruitful and please type it up +in latch and submit it through great + + align:start position:0% +in latch and submit it through great + + + align:start position:0% +in latch and submit it through great +scope questions + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +yeah + + align:start position:0% + + + + align:start position:0% + +oh you what why can't you do don't you + + align:start position:0% +oh you what why can't you do don't you + + + align:start position:0% +oh you what why can't you do don't you +use grade scope for other classes yeah + + align:start position:0% +use grade scope for other classes yeah + + + align:start position:0% +use grade scope for other classes yeah +but I have not seen this class oh no it + + align:start position:0% +but I have not seen this class oh no it + + + align:start position:0% +but I have not seen this class oh no it +is it is now when did you check + + align:start position:0% +is it is now when did you check + + + align:start position:0% +is it is now when did you check +oh yeah it's recently uh yeah if there's + + align:start position:0% +oh yeah it's recently uh yeah if there's + + + align:start position:0% +oh yeah it's recently uh yeah if there's +issues let me know yeah this class is + + align:start position:0% +issues let me know yeah this class is + + + align:start position:0% +issues let me know yeah this class is +assigned to there is a great scope site + + align:start position:0% +assigned to there is a great scope site + + + align:start position:0% +assigned to there is a great scope site +for + + align:start position:0% +for + + + align:start position:0% +for +this uh any any other questions before + + align:start position:0% +this uh any any other questions before + + + align:start position:0% +this uh any any other questions before +we + + align:start position:0% + + + + align:start position:0% + +start okay so uh just a quick a quick + + align:start position:0% +start okay so uh just a quick a quick + + + align:start position:0% +start okay so uh just a quick a quick +recap uh so last time we talked Al about + + align:start position:0% +recap uh so last time we talked Al about + + + align:start position:0% +recap uh so last time we talked Al about +the kilan mikali protocol it's an + + align:start position:0% +the kilan mikali protocol it's an + + + align:start position:0% +the kilan mikali protocol it's an +interactive argument it's a succinct + + align:start position:0% +interactive argument it's a succinct + + + align:start position:0% +interactive argument it's a succinct +interactive argument that which you can + + align:start position:0% +interactive argument that which you can + + + align:start position:0% +interactive argument that which you can +use to prove uh membership in any NP + + align:start position:0% +use to prove uh membership in any NP + + + align:start position:0% +use to prove uh membership in any NP +language okay if you recall the idea was + + align:start position:0% +language okay if you recall the idea was + + + align:start position:0% +language okay if you recall the idea was +we started before that was kind of our + + align:start position:0% +we started before that was kind of our + + + align:start position:0% +we started before that was kind of our +entrance to to cryptography so we said + + align:start position:0% +entrance to to cryptography so we said + + + align:start position:0% +entrance to to cryptography so we said +the idea of the K mic protocol is that + + align:start position:0% +the idea of the K mic protocol is that + + + align:start position:0% +the idea of the K mic protocol is that +you take any PCP which is very very + + align:start position:0% +you take any PCP which is very very + + + align:start position:0% +you take any PCP which is very very +large but very efficiently if you just + + align:start position:0% +large but very efficiently if you just + + + align:start position:0% +large but very efficiently if you just +have Ram access to it you can verify it + + align:start position:0% +have Ram access to it you can verify it + + + align:start position:0% +have Ram access to it you can verify it +very efficiently + + align:start position:0% +very efficiently + + + align:start position:0% +very efficiently +and the idea is you take this very very + + align:start position:0% +and the idea is you take this very very + + + align:start position:0% +and the idea is you take this very very +large PCP and you kind of shrink it to + + align:start position:0% +large PCP and you kind of shrink it to + + + align:start position:0% +large PCP and you kind of shrink it to +kind of a you uh you know uh digest it + + align:start position:0% +kind of a you uh you know uh digest it + + + align:start position:0% +kind of a you uh you know uh digest it +down uh using cryptography to this kind + + align:start position:0% +down uh using cryptography to this kind + + + align:start position:0% +down uh using cryptography to this kind +of suing digest this is done using + + align:start position:0% +of suing digest this is done using + + + align:start position:0% +of suing digest this is done using +what's called using hash function but in + + align:start position:0% +what's called using hash function but in + + + align:start position:0% +what's called using hash function but in +particular mirle hash or hash function + + align:start position:0% +particular mirle hash or hash function + + + align:start position:0% +particular mirle hash or hash function +that are sixing but can be opened + + align:start position:0% +that are sixing but can be opened + + + align:start position:0% +that are sixing but can be opened +locally so I'll recall what this is in a + + align:start position:0% +locally so I'll recall what this is in a + + + align:start position:0% +locally so I'll recall what this is in a +second and once the prover sends over + + align:start position:0% +second and once the prover sends over + + + align:start position:0% +second and once the prover sends over +kind of a uh squished form of the PC + + align:start position:0% +kind of a uh squished form of the PC + + + align:start position:0% +kind of a uh squished form of the PC +then the verifier now behav like he's a + + align:start position:0% +then the verifier now behav like he's a + + + align:start position:0% +then the verifier now behav like he's a +PCP verifier he tells the Prov open this + + align:start position:0% +PCP verifier he tells the Prov open this + + + align:start position:0% +PCP verifier he tells the Prov open this +PCP and the location that the PCP + + align:start position:0% +PCP and the location that the PCP + + + align:start position:0% +PCP and the location that the PCP +verifier would want to open and he gets + + align:start position:0% +verifier would want to open and he gets + + + align:start position:0% +verifier would want to open and he gets +back the openings so uh so that's kind + + align:start position:0% +back the openings so uh so that's kind + + + align:start position:0% +back the openings so uh so that's kind +of what the Kil mikali protocol is but + + align:start position:0% +of what the Kil mikali protocol is but + + + align:start position:0% +of what the Kil mikali protocol is but +in order to to uh when I said you know + + align:start position:0% +in order to to uh when I said you know + + + align:start position:0% +in order to to uh when I said you know +it squishes down and then there's + + align:start position:0% +it squishes down and then there's + + + align:start position:0% +it squishes down and then there's +opening really what we need is a we want + + align:start position:0% +opening really what we need is a we want + + + align:start position:0% +opening really what we need is a we want +to take a hash function so if you + + align:start position:0% +to take a hash function so if you + + + align:start position:0% +to take a hash function so if you +remember a hash hash function is kind of + + align:start position:0% +remember a hash hash function is kind of + + + align:start position:0% +remember a hash hash function is kind of +consists of a key generation algorithm + + align:start position:0% +consists of a key generation algorithm + + + align:start position:0% +consists of a key generation algorithm +that generates a hash key and an eval + + align:start position:0% +that generates a hash key and an eval + + + align:start position:0% +that generates a hash key and an eval +algorithm that take a hash and an input + + align:start position:0% +algorithm that take a hash and an input + + + align:start position:0% +algorithm that take a hash and an input +and generates kind of a digest or a hash + + align:start position:0% +and generates kind of a digest or a hash + + + align:start position:0% +and generates kind of a digest or a hash +value a last time we uh we talk we + + align:start position:0% +value a last time we uh we talk we + + + align:start position:0% +value a last time we uh we talk we +showed how to get a a hash value uh how + + align:start position:0% +showed how to get a a hash value uh how + + + align:start position:0% +showed how to get a a hash value uh how +to construct from uh the discrete log we + + align:start position:0% +to construct from uh the discrete log we + + + align:start position:0% +to construct from uh the discrete log we +showed how to construct a hash function + + align:start position:0% +showed how to construct a hash function + + + align:start position:0% +showed how to construct a hash function +uh uh from two Lambda to Lambda it takes + + align:start position:0% +uh uh from two Lambda to Lambda it takes + + + align:start position:0% +uh uh from two Lambda to Lambda it takes +2 Lambda bit Lambda B actually was z p + + align:start position:0% +2 Lambda bit Lambda B actually was z p + + + align:start position:0% +2 Lambda bit Lambda B actually was z p +to the 2 Lambda to zp to Lambda but + + align:start position:0% +to the 2 Lambda to zp to Lambda but + + + align:start position:0% +to the 2 Lambda to zp to Lambda but +anyway one can encoded to have to be 01 + + align:start position:0% +anyway one can encoded to have to be 01 + + + align:start position:0% +anyway one can encoded to have to be 01 +to the 2 Lambda to 0 1 to the + + align:start position:0% +to the 2 Lambda to 0 1 to the + + + align:start position:0% +to the 2 Lambda to 0 1 to the +Lambda but this is actually not enough + + align:start position:0% +Lambda but this is actually not enough + + + align:start position:0% +Lambda but this is actually not enough +for the Kil M protocol what we actually + + align:start position:0% +for the Kil M protocol what we actually + + + align:start position:0% +for the Kil M protocol what we actually +need is a collision hash function first + + align:start position:0% +need is a collision hash function first + + + align:start position:0% +need is a collision hash function first +it needs to be much bigger because we're + + align:start position:0% +it needs to be much bigger because we're + + + align:start position:0% +it needs to be much bigger because we're +taking a gigantic PCP we want to squish + + align:start position:0% +taking a gigantic PCP we want to squish + + + align:start position:0% +taking a gigantic PCP we want to squish +it way more than like half this takes + + align:start position:0% +it way more than like half this takes + + + align:start position:0% +it way more than like half this takes +you know make squishes the size reduces + + align:start position:0% +you know make squishes the size reduces + + + align:start position:0% +you know make squishes the size reduces +the size from two Lambda to Lambda so it + + align:start position:0% +the size from two Lambda to Lambda so it + + + align:start position:0% +the size from two Lambda to Lambda so it +squishes it by factor of two we actually + + align:start position:0% +squishes it by factor of two we actually + + + align:start position:0% +squishes it by factor of two we actually +want to squish it to much bigger Factor + + align:start position:0% +want to squish it to much bigger Factor + + + align:start position:0% +want to squish it to much bigger Factor +okay so we want to take kind of eval + + align:start position:0% +okay so we want to take kind of eval + + + align:start position:0% +okay so we want to take kind of eval +what we what we use actually is an eval + + align:start position:0% +what we what we use actually is an eval + + + align:start position:0% +what we what we use actually is an eval +algorithm that takes strings of size two + + align:start position:0% +algorithm that takes strings of size two + + + align:start position:0% +algorithm that takes strings of size two +to the Lambda to Lambda so note here the + + align:start position:0% +to the Lambda to Lambda so note here the + + + align:start position:0% +to the Lambda to Lambda so note here the +Lambda is upstairs it's very different + + align:start position:0% +Lambda is upstairs it's very different + + + align:start position:0% +Lambda is upstairs it's very different +than two Lambda it's exponential + + align:start position:0% +than two Lambda it's exponential + + + align:start position:0% +than two Lambda it's exponential +difference a so we take a a hash + + align:start position:0% +difference a so we take a a hash + + + align:start position:0% +difference a so we take a a hash +function that goes takes gigantic + + align:start position:0% +function that goes takes gigantic + + + align:start position:0% +function that goes takes gigantic +strings to lamb + + align:start position:0% +strings to lamb + + + align:start position:0% +strings to lamb +and moreover another property that we + + align:start position:0% +and moreover another property that we + + + align:start position:0% +and moreover another property that we +want is we can open locally remember we + + align:start position:0% +want is we can open locally remember we + + + align:start position:0% +want is we can open locally remember we +said the way the mikali protocol works + + align:start position:0% +said the way the mikali protocol works + + + align:start position:0% +said the way the mikali protocol works +is that the verifier asks okay you + + align:start position:0% +is that the verifier asks okay you + + + align:start position:0% +is that the verifier asks okay you +committed to the gigantic PCP open it in + + align:start position:0% +committed to the gigantic PCP open it in + + + align:start position:0% +committed to the gigantic PCP open it in +location you know 37 and 15 now how do + + align:start position:0% +location you know 37 and 15 now how do + + + align:start position:0% +location you know 37 and 15 now how do +you open it so we also want kind of a a + + align:start position:0% +you open it so we also want kind of a a + + + align:start position:0% +you open it so we also want kind of a a +opening algorithm so really what we + + align:start position:0% +opening algorithm so really what we + + + align:start position:0% +opening algorithm so really what we +needed when we talked about Miracle hash + + align:start position:0% +needed when we talked about Miracle hash + + + align:start position:0% +needed when we talked about Miracle hash +or hash hashes with local opening in + + align:start position:0% +or hash hashes with local opening in + + + align:start position:0% +or hash hashes with local opening in +addition to having a key generation and + + align:start position:0% +addition to having a key generation and + + + align:start position:0% +addition to having a key generation and +eval algorithm we also have a open + + align:start position:0% +eval algorithm we also have a open + + + align:start position:0% +eval algorithm we also have a open +algorithm that generates kind of a + + align:start position:0% +algorithm that generates kind of a + + + align:start position:0% +algorithm that generates kind of a +succinct + + align:start position:0% +succinct + + + align:start position:0% +succinct +opening and you which can be verified in + + align:start position:0% +opening and you which can be verified in + + + align:start position:0% +opening and you which can be verified in +a verification algorithm that verifies + + align:start position:0% +a verification algorithm that verifies + + + align:start position:0% +a verification algorithm that verifies +it so last time we we kind of + + align:start position:0% +it so last time we we kind of + + + align:start position:0% +it so last time we we kind of +constructed this morle hatch I'll recall + + align:start position:0% +constructed this morle hatch I'll recall + + + align:start position:0% +constructed this morle hatch I'll recall +it today quickly and we ended without + + align:start position:0% +it today quickly and we ended without + + + align:start position:0% +it today quickly and we ended without +kind of proving that it's collagen + + align:start position:0% +kind of proving that it's collagen + + + align:start position:0% +kind of proving that it's collagen +resistant so that's where we're going to + + align:start position:0% +resistant so that's where we're going to + + + align:start position:0% +resistant so that's where we're going to +start today we're going to just wrap up + + align:start position:0% +start today we're going to just wrap up + + + align:start position:0% +start today we're going to just wrap up +the K mikali + + align:start position:0% +the K mikali + + + align:start position:0% +the K mikali +protocol by explaining the thing that + + align:start position:0% +protocol by explaining the thing that + + + align:start position:0% +protocol by explaining the thing that +was left is kind of to argue that this + + align:start position:0% +was left is kind of to argue that this + + + align:start position:0% +was left is kind of to argue that this +Merkel hash + + align:start position:0% +Merkel hash + + + align:start position:0% +Merkel hash +construction is indeed Collision + + align:start position:0% +construction is indeed Collision + + + align:start position:0% +construction is indeed Collision +resistance so that's where we're going + + align:start position:0% +resistance so that's where we're going + + + align:start position:0% +resistance so that's where we're going +to start today but then uh so once we do + + align:start position:0% +to start today but then uh so once we do + + + align:start position:0% +to start today but then uh so once we do +that once we argue that the we have this + + align:start position:0% +that once we argue that the we have this + + + align:start position:0% +that once we argue that the we have this +Merkel hash we put that it's Collision + + align:start position:0% +Merkel hash we put that it's Collision + + + align:start position:0% +Merkel hash we put that it's Collision +resistant then we're done with the kill + + align:start position:0% +resistant then we're done with the kill + + + align:start position:0% +resistant then we're done with the kill +M you actually proved that it sound + + align:start position:0% +M you actually proved that it sound + + + align:start position:0% +M you actually proved that it sound +under this + + align:start position:0% +under this + + + align:start position:0% +under this +assumption so so okay so where are we + + align:start position:0% +assumption so so okay so where are we + + + align:start position:0% +assumption so so okay so where are we +heading today after we finished the + + align:start position:0% +heading today after we finished the + + + align:start position:0% +heading today after we finished the +Merkel hash now we we actually showed a + + align:start position:0% +Merkel hash now we we actually showed a + + + align:start position:0% +Merkel hash now we we actually showed a +succinct argument for all of NP this is + + align:start position:0% +succinct argument for all of NP this is + + + align:start position:0% +succinct argument for all of NP this is +great however it's + + align:start position:0% +great however it's + + + align:start position:0% +great however it's +interactive and interactive proofs or + + align:start position:0% +interactive and interactive proofs or + + + align:start position:0% +interactive and interactive proofs or +arguments are really they're not very + + align:start position:0% +arguments are really they're not very + + + align:start position:0% +arguments are really they're not very +useful and the reason they're not very + + align:start position:0% +useful and the reason they're not very + + + align:start position:0% +useful and the reason they're not very +useful is for many reasons a there's + + align:start position:0% +useful is for many reasons a there's + + + align:start position:0% +useful is for many reasons a there's +latency to talk back forth back forth + + align:start position:0% +latency to talk back forth back forth + + + align:start position:0% +latency to talk back forth back forth +but another reason perhaps much more + + align:start position:0% +but another reason perhaps much more + + + align:start position:0% +but another reason perhaps much more +important is that it's per per verifier + + align:start position:0% +important is that it's per per verifier + + + align:start position:0% +important is that it's per per verifier +so if I want to just prove to the world + + align:start position:0% +so if I want to just prove to the world + + + align:start position:0% +so if I want to just prove to the world +some statement I can't prove it using I + + align:start position:0% +some statement I can't prove it using I + + + align:start position:0% +some statement I can't prove it using I +I'm not gonna go to each person in the + + align:start position:0% +I'm not gonna go to each person in the + + + align:start position:0% +I'm not gonna go to each person in the +world and give him an an interactive + + align:start position:0% +world and give him an an interactive + + + align:start position:0% +world and give him an an interactive +proof so it's really verifier specific + + align:start position:0% +proof so it's really verifier specific + + + align:start position:0% +proof so it's really verifier specific +interactive proofs are verifier specific + + align:start position:0% +interactive proofs are verifier specific + + + align:start position:0% +interactive proofs are verifier specific +it convinces the specific verifier you + + align:start position:0% +it convinces the specific verifier you + + + align:start position:0% +it convinces the specific verifier you +talk + + align:start position:0% +talk + + + align:start position:0% +talk +with okay and we want to prove that + + align:start position:0% +with okay and we want to prove that + + + align:start position:0% +with okay and we want to prove that +convinces + + align:start position:0% +convinces + + + align:start position:0% +convinces +everyone so that's kind of where the + + align:start position:0% +everyone so that's kind of where the + + + align:start position:0% +everyone so that's kind of where the +segue we're taking today how do we + + align:start position:0% +segue we're taking today how do we + + + align:start position:0% +segue we're taking today how do we +construct actually + + align:start position:0% +construct actually + + + align:start position:0% +construct actually +non-interactive R now to reduce + + align:start position:0% +non-interactive R now to reduce + + + align:start position:0% +non-interactive R now to reduce +interraction okay so what we're going to + + align:start position:0% +interraction okay so what we're going to + + + align:start position:0% +interraction okay so what we're going to +show is how to eliminate interaction and + + align:start position:0% +show is how to eliminate interaction and + + + align:start position:0% +show is how to eliminate interaction and +this is going to be done using a really + + align:start position:0% +this is going to be done using a really + + + align:start position:0% +this is going to be done using a really +beautiful Paradigm called the F Paradigm + + align:start position:0% +beautiful Paradigm called the F Paradigm + + + align:start position:0% +beautiful Paradigm called the F Paradigm +so I'm going to explain what it is it's + + align:start position:0% +so I'm going to explain what it is it's + + + align:start position:0% +so I'm going to explain what it is it's +very very simple and then we're going to + + align:start position:0% +very very simple and then we're going to + + + align:start position:0% +very very simple and then we're going to +introduce the random Oracle model which + + align:start position:0% +introduce the random Oracle model which + + + align:start position:0% +introduce the random Oracle model which +is a model that was invented in order to + + align:start position:0% +is a model that was invented in order to + + + align:start position:0% +is a model that was invented in order to +an attempt to analyze or to understand + + align:start position:0% +an attempt to analyze or to understand + + + align:start position:0% +an attempt to analyze or to understand +the security of this F Paradigm uh it's + + align:start position:0% +the security of this F Paradigm uh it's + + + align:start position:0% +the security of this F Paradigm uh it's +an ideal model okay we're gonna prove + + align:start position:0% +an ideal model okay we're gonna prove + + + align:start position:0% +an ideal model okay we're gonna prove +the soundness of the Kil mikali protocol + + align:start position:0% +the soundness of the Kil mikali protocol + + + align:start position:0% +the soundness of the Kil mikali protocol +that we we saw last time we're going to + + align:start position:0% +that we we saw last time we're going to + + + align:start position:0% +that we we saw last time we're going to +actually show that it sound uh even if + + align:start position:0% +actually show that it sound uh even if + + + align:start position:0% +actually show that it sound uh even if +you apply the F Paradigm to it as long + + align:start position:0% +you apply the F Paradigm to it as long + + + align:start position:0% +you apply the F Paradigm to it as long +as you rign this random Oracle model and + + align:start position:0% +as you rign this random Oracle model and + + + align:start position:0% +as you rign this random Oracle model and +this ideal + + align:start position:0% +this ideal + + + align:start position:0% +this ideal +model and then we're going to probably + + align:start position:0% +model and then we're going to probably + + + align:start position:0% +model and then we're going to probably +this we're going to only get till next + + align:start position:0% +this we're going to only get till next + + + align:start position:0% +this we're going to only get till next +time but we're going to try to we're + + align:start position:0% +time but we're going to try to we're + + + align:start position:0% +time but we're going to try to we're +talk about the soundness uh of the F and + + align:start position:0% +talk about the soundness uh of the F and + + + align:start position:0% +talk about the soundness uh of the F and +the standard model okay so again we're + + align:start position:0% +the standard model okay so again we're + + + align:start position:0% +the standard model okay so again we're +going to talk about eliminating + + align:start position:0% +going to talk about eliminating + + + align:start position:0% +going to talk about eliminating +interaction using F talk about the + + align:start position:0% +interaction using F talk about the + + + align:start position:0% +interaction using F talk about the +random orical model show that actually + + align:start position:0% +random orical model show that actually + + + align:start position:0% +random orical model show that actually +the random oral model of this Paradigm + + align:start position:0% +the random oral model of this Paradigm + + + align:start position:0% +the random oral model of this Paradigm +works well often uh we'll see exactly + + align:start position:0% +works well often uh we'll see exactly + + + align:start position:0% +works well often uh we'll see exactly +when it works well when it doesn't and + + align:start position:0% +when it works well when it doesn't and + + + align:start position:0% +when it works well when it doesn't and +then we're going to talk about if we + + align:start position:0% +then we're going to talk about if we + + + align:start position:0% +then we're going to talk about if we +have time maybe start talking about uh + + align:start position:0% +have time maybe start talking about uh + + + align:start position:0% +have time maybe start talking about uh +about Security in that standard model + + align:start position:0% +about Security in that standard model + + + align:start position:0% +about Security in that standard model +because the random work model is not + + align:start position:0% +because the random work model is not + + + align:start position:0% +because the random work model is not +it's a it's an ideal model so is it + + align:start position:0% +it's a it's an ideal model so is it + + + align:start position:0% +it's a it's an ideal model so is it +secure is it sound like in when used in + + align:start position:0% +secure is it sound like in when used in + + + align:start position:0% +secure is it sound like in when used in +actual + + align:start position:0% +actual + + + align:start position:0% +actual +reality that's the plan questions yes + + align:start position:0% +reality that's the plan questions yes + + + align:start position:0% +reality that's the plan questions yes +you shouldn't be able to do two of the + + align:start position:0% + + + + align:start position:0% + +land you're something that long you find + + align:start position:0% +land you're something that long you find + + + align:start position:0% +land you're something that long you find +a oh okay so um uh okay uh of course of + + align:start position:0% +a oh okay so um uh okay uh of course of + + + align:start position:0% +a oh okay so um uh okay uh of course of +course you can find the Collision the qu + + align:start position:0% +course you can find the Collision the qu + + + align:start position:0% +course you can find the Collision the qu +okay so I we Define it okay so the + + align:start position:0% +okay so I we Define it okay so the + + + align:start position:0% +okay so I we Define it okay so the +question was about this two two to the + + align:start position:0% +question was about this two two to the + + + align:start position:0% +question was about this two two to the +Lambda let me get let me now we'll see + + align:start position:0% +Lambda let me get let me now we'll see + + + align:start position:0% +Lambda let me get let me now we'll see +the definition the construction I'll + + align:start position:0% +the definition the construction I'll + + + align:start position:0% +the definition the construction I'll +explain but the the we get we get + + align:start position:0% +explain but the the we get we get + + + align:start position:0% +explain but the the we get we get +completeness for two to the Lambda now + + align:start position:0% +completeness for two to the Lambda now + + + align:start position:0% +completeness for two to the Lambda now +you're talking about soundness okay + + align:start position:0% +you're talking about soundness okay + + + align:start position:0% +you're talking about soundness okay +soundness says that any poly adversary + + align:start position:0% +soundness says that any poly adversary + + + align:start position:0% +soundness says that any poly adversary +or t time adversary yeah poly Lambda + + align:start position:0% +or t time adversary yeah poly Lambda + + + align:start position:0% +or t time adversary yeah poly Lambda +adversary or po or t poly in t Lambda + + align:start position:0% +adversary or po or t poly in t Lambda + + + align:start position:0% +adversary or po or t poly in t Lambda +adversary + + align:start position:0% +adversary + + + align:start position:0% +adversary +cannot find a collision now if this T is + + align:start position:0% +cannot find a collision now if this T is + + + align:start position:0% +cannot find a collision now if this T is +two to the Lambda then you're not going + + align:start position:0% +two to the Lambda then you're not going + + + align:start position:0% +two to the Lambda then you're not going +to be secure so that I mean the + + align:start position:0% +to be secure so that I mean the + + + align:start position:0% +to be secure so that I mean the +Assumption R so there's this is for + + align:start position:0% +Assumption R so there's this is for + + + align:start position:0% +Assumption R so there's this is for +completeness for soundness the + + align:start position:0% +completeness for soundness the + + + align:start position:0% +completeness for soundness the +assumption is for Collision resistance + + align:start position:0% +assumption is for Collision resistance + + + align:start position:0% +assumption is for Collision resistance +the the definition is that no poly + + align:start position:0% +the the definition is that no poly + + + align:start position:0% +the the definition is that no poly +Lambda time or poly T Lambda depending + + align:start position:0% +Lambda time or poly T Lambda depending + + + align:start position:0% +Lambda time or poly T Lambda depending +on if you want standard Collision + + align:start position:0% +on if you want standard Collision + + + align:start position:0% +on if you want standard Collision +resistant or T Collision resistant which + + align:start position:0% +resistant or T Collision resistant which + + + align:start position:0% +resistant or T Collision resistant which +is slightly stronger assumption cannot + + align:start position:0% +is slightly stronger assumption cannot + + + align:start position:0% +is slightly stronger assumption cannot +find + + align:start position:0% +find + + + align:start position:0% +find +collisions great thank thanks for the + + align:start position:0% +collisions great thank thanks for the + + + align:start position:0% +collisions great thank thanks for the +question any any other + + align:start position:0% +question any any other + + + align:start position:0% +question any any other +questions I like questions just + + align:start position:0% +questions I like questions just + + + align:start position:0% +questions I like questions just +reminding you + + align:start position:0% +reminding you + + + align:start position:0% +reminding you +guys okay yeah so during this whole + + align:start position:0% +guys okay yeah so during this whole + + + align:start position:0% +guys okay yeah so during this whole +thing I'm trying to imagine like how big + + align:start position:0% +thing I'm trying to imagine like how big + + + align:start position:0% +thing I'm trying to imagine like how big +are the parameters so n like inside of + + align:start position:0% +are the parameters so n like inside of + + + align:start position:0% +are the parameters so n like inside of +the input is something that's like like + + align:start position:0% +the input is something that's like like + + + align:start position:0% +the input is something that's like like +normal people can read right yeah yeah + + align:start position:0% +normal people can read right yeah yeah + + + align:start position:0% +normal people can read right yeah yeah +yeah yeah yeah yeah exactly okay so let + + align:start position:0% +yeah yeah yeah yeah exactly okay so let + + + align:start position:0% +yeah yeah yeah yeah exactly okay so let +me yeah let me talk a little bit about + + align:start position:0% +me yeah let me talk a little bit about + + + align:start position:0% +me yeah let me talk a little bit about +the parameters that's a great question + + align:start position:0% +the parameters that's a great question + + + align:start position:0% +the parameters that's a great question +that's a good good thing to start with + + align:start position:0% +that's a good good thing to start with + + + align:start position:0% +that's a good good thing to start with +so we want succinctness okay now when we + + align:start position:0% +so we want succinctness okay now when we + + + align:start position:0% +so we want succinctness okay now when we +say succinct really what we want is so + + align:start position:0% +say succinct really what we want is so + + + align:start position:0% +say succinct really what we want is so +we that's the things by using + + align:start position:0% +we that's the things by using + + + align:start position:0% +we that's the things by using +cryptography once we use cryptography + + align:start position:0% +cryptography once we use cryptography + + + align:start position:0% +cryptography once we use cryptography +things grow with the security of the + + align:start position:0% +things grow with the security of the + + + align:start position:0% +things grow with the security of the +that we want so things will grow with + + align:start position:0% +that we want so things will grow with + + + align:start position:0% +that we want so things will grow with +Lambda which is the security parameter + + align:start position:0% +Lambda which is the security parameter + + + align:start position:0% +Lambda which is the security parameter +what the security parameter is depends + + align:start position:0% +what the security parameter is depends + + + align:start position:0% +what the security parameter is depends +kind of how paranoid we are in the world + + align:start position:0% +kind of how paranoid we are in the world + + + align:start position:0% +kind of how paranoid we are in the world +okay you can think about it is 256 bits + + align:start position:0% +okay you can think about it is 256 bits + + + align:start position:0% +okay you can think about it is 256 bits +sometimes it's more depending on also + + align:start position:0% +sometimes it's more depending on also + + + align:start position:0% +sometimes it's more depending on also +which crypto systems you use but that's + + align:start position:0% +which crypto systems you use but that's + + + align:start position:0% +which crypto systems you use but that's +a good it's kind of independent of the + + align:start position:0% +a good it's kind of independent of the + + + align:start position:0% +a good it's kind of independent of the +input okay just you want as succinct as + + align:start position:0% +input okay just you want as succinct as + + + align:start position:0% +input okay just you want as succinct as +you can get and you know if you want to + + align:start position:0% +you can get and you know if you want to + + + align:start position:0% +you can get and you know if you want to +use cryptography it's it's like security + + align:start position:0% +use cryptography it's it's like security + + + align:start position:0% +use cryptography it's it's like security +parameter now the input it should in + + align:start position:0% +parameter now the input it should in + + + align:start position:0% +parameter now the input it should in +some sense it should not depend on the + + align:start position:0% +some sense it should not depend on the + + + align:start position:0% +some sense it should not depend on the +input but of course the input is not + + align:start position:0% +input but of course the input is not + + + align:start position:0% +input but of course the input is not +going to be like more than two to the + + align:start position:0% +going to be like more than two to the + + + align:start position:0% +going to be like more than two to the +Lambda because you think of Lambda is + + align:start position:0% +Lambda because you think of Lambda is + + + align:start position:0% +Lambda because you think of Lambda is +such that two to the Lambda is like more + + align:start position:0% +such that two to the Lambda is like more + + + align:start position:0% +such that two to the Lambda is like more +than the number of of molecules in the + + align:start position:0% +than the number of of molecules in the + + + align:start position:0% +than the number of of molecules in the +universe so nothing is that big in our + + align:start position:0% +universe so nothing is that big in our + + + align:start position:0% +universe so nothing is that big in our +world okay so you think of the X can be + + align:start position:0% +world okay so you think of the X can be + + + align:start position:0% +world okay so you think of the X can be +bigger actually the input can also be + + align:start position:0% +bigger actually the input can also be + + + align:start position:0% +bigger actually the input can also be +small you know but then sometimes you + + align:start position:0% +small you know but then sometimes you + + + align:start position:0% +small you know but then sometimes you +don't need cryptography so so tiny it's + + align:start position:0% +don't need cryptography so so tiny it's + + + align:start position:0% +don't need cryptography so so tiny it's +like phography is useless uh you can + + align:start position:0% +like phography is useless uh you can + + + align:start position:0% +like phography is useless uh you can +just give the witness um so usually we + + align:start position:0% +just give the witness um so usually we + + + align:start position:0% +just give the witness um so usually we +think think in our head of the input as + + align:start position:0% +think think in our head of the input as + + + align:start position:0% +think think in our head of the input as +being can be much bigger than Lambda can + + align:start position:0% +being can be much bigger than Lambda can + + + align:start position:0% +being can be much bigger than Lambda can +be poly Lambda and maybe even be like + + align:start position:0% +be poly Lambda and maybe even be like + + + align:start position:0% +be poly Lambda and maybe even be like +Lambda to the log Lambda it can be you + + align:start position:0% +Lambda to the log Lambda it can be you + + + align:start position:0% +Lambda to the log Lambda it can be you +know but it's not as big as two to the + + align:start position:0% +know but it's not as big as two to the + + + align:start position:0% +know but it's not as big as two to the +Lambda that's doesn't exist okay but it + + align:start position:0% +Lambda that's doesn't exist okay but it + + + align:start position:0% +Lambda that's doesn't exist okay but it +can be kind of anything that's kind of + + align:start position:0% +can be kind of anything that's kind of + + + align:start position:0% +can be kind of anything that's kind of +real world number in in the sense um and + + align:start position:0% +real world number in in the sense um and + + + align:start position:0% +real world number in in the sense um and +so that's kind of what what we should + + align:start position:0% +so that's kind of what what we should + + + align:start position:0% +so that's kind of what what we should +think of okay does + + align:start position:0% +think of okay does + + + align:start position:0% +think of okay does +that okay so when we do we're trying to + + align:start position:0% +that okay so when we do we're trying to + + + align:start position:0% +that okay so when we do we're trying to +reduce the amount of the side of the pro + + align:start position:0% +reduce the amount of the side of the pro + + + align:start position:0% +reduce the amount of the side of the pro +from like still a reasonable polze thing + + align:start position:0% +from like still a reasonable polze thing + + + align:start position:0% +from like still a reasonable polze thing +but just like a 26 exactly exactly or or + + align:start position:0% +but just like a 26 exactly exactly or or + + + align:start position:0% +but just like a 26 exactly exactly or or +right so you can think of it you're + + align:start position:0% +right so you can think of it you're + + + align:start position:0% +right so you can think of it you're +trying to when when you do and let me + + align:start position:0% +trying to when when you do and let me + + + align:start position:0% +trying to when when you do and let me +just repeat it also for the mic uh when + + align:start position:0% +just repeat it also for the mic uh when + + + align:start position:0% +just repeat it also for the mic uh when +you're trying uh when you do this + + align:start position:0% +you're trying uh when you do this + + + align:start position:0% +you're trying uh when you do this +interactive argument you think of you + + align:start position:0% +interactive argument you think of you + + + align:start position:0% +interactive argument you think of you +take an X that's still real world you + + align:start position:0% +take an X that's still real world you + + + align:start position:0% +take an X that's still real world you +can think of it polom l but it can be + + align:start position:0% +can think of it polom l but it can be + + + align:start position:0% +can think of it polom l but it can be +more but as long as a kind of real world + + align:start position:0% +more but as long as a kind of real world + + + align:start position:0% +more but as long as a kind of real world +thing and you reduce it to kind of 256 + + align:start position:0% +thing and you reduce it to kind of 256 + + + align:start position:0% +thing and you reduce it to kind of 256 +bits okay that's kind of the um the + + align:start position:0% +bits okay that's kind of the um the + + + align:start position:0% +bits okay that's kind of the um the +Practical idea you should think of and + + align:start position:0% +Practical idea you should think of and + + + align:start position:0% +Practical idea you should think of and +the more theoretical idea is to say you + + align:start position:0% +the more theoretical idea is to say you + + + align:start position:0% +the more theoretical idea is to say you +can take any input X but not more than + + align:start position:0% +can take any input X but not more than + + + align:start position:0% +can take any input X but not more than +two to the Lambda because that's like + + align:start position:0% +two to the Lambda because that's like + + + align:start position:0% +two to the Lambda because that's like +you know but something anything less and + + align:start position:0% +you know but something anything less and + + + align:start position:0% +you know but something anything less and +we make it as small as as po + + align:start position:0% +we make it as small as as po + + + align:start position:0% +we make it as small as as po +Lambda okay great any any other + + align:start position:0% +Lambda okay great any any other + + + align:start position:0% +Lambda okay great any any other +questions yeah and verify that row is + + align:start position:0% +questions yeah and verify that row is + + + align:start position:0% +questions yeah and verify that row is +like the opening is that what it + + align:start position:0% +like the opening is that what it + + + align:start position:0% +like the opening is that what it +is yes yes yes yeah yeah sorry yes this + + align:start position:0% +is yes yes yes yeah yeah sorry yes this + + + align:start position:0% +is yes yes yes yeah yeah sorry yes this +is yeah I'll I'll go to it now yeah yeah + + align:start position:0% +is yeah I'll I'll go to it now yeah yeah + + + align:start position:0% +is yeah I'll I'll go to it now yeah yeah +yeah yeah yeah yeah let me let me okay + + align:start position:0% +yeah yeah yeah yeah let me let me okay + + + align:start position:0% +yeah yeah yeah yeah let me let me okay +so good so let me uh just finish wrap up + + align:start position:0% +so good so let me uh just finish wrap up + + + align:start position:0% +so good so let me uh just finish wrap up +what we where we left last time which is + + align:start position:0% +what we where we left last time which is + + + align:start position:0% +what we where we left last time which is +the Merle hash so we use ml hash in the + + align:start position:0% +the Merle hash so we use ml hash in the + + + align:start position:0% +the Merle hash so we use ml hash in the +kilan mikali protocol actually we don't + + align:start position:0% +kilan mikali protocol actually we don't + + + align:start position:0% +kilan mikali protocol actually we don't +need to really remember the kilan mikali + + align:start position:0% +need to really remember the kilan mikali + + + align:start position:0% +need to really remember the kilan mikali +protocol for today we're not going to + + align:start position:0% +protocol for today we're not going to + + + align:start position:0% +protocol for today we're not going to +actually really use it but let me still + + align:start position:0% +actually really use it but let me still + + + align:start position:0% +actually really use it but let me still +finish the Merle hash because it's a + + align:start position:0% +finish the Merle hash because it's a + + + align:start position:0% +finish the Merle hash because it's a +very important primitive it's kind of + + align:start position:0% +very important primitive it's kind of + + + align:start position:0% +very important primitive it's kind of +used everywhere in cryptography so it's + + align:start position:0% +used everywhere in cryptography so it's + + + align:start position:0% +used everywhere in cryptography so it's +very important to know so uh so what is + + align:start position:0% +very important to know so uh so what is + + + align:start position:0% +very important to know so uh so what is +the miracle hash it takes any hash + + align:start position:0% +the miracle hash it takes any hash + + + align:start position:0% +the miracle hash it takes any hash +function not local opening just a + + align:start position:0% +function not local opening just a + + + align:start position:0% +function not local opening just a +regular hash function that generates a + + align:start position:0% +regular hash function that generates a + + + align:start position:0% +regular hash function that generates a +hash key and has an eval algorithm + + align:start position:0% +hash key and has an eval algorithm + + + align:start position:0% +hash key and has an eval algorithm +evaluates just generates hash value such + + align:start position:0% +evaluates just generates hash value such + + + align:start position:0% +evaluates just generates hash value such +that it takes two Lambda bits to Lambda + + align:start position:0% +that it takes two Lambda bits to Lambda + + + align:start position:0% +that it takes two Lambda bits to Lambda +bits okay you can actually you can make + + align:start position:0% +bits okay you can actually you can make + + + align:start position:0% +bits okay you can actually you can make +it more you can be even one plus Epsilon + + align:start position:0% +it more you can be even one plus Epsilon + + + align:start position:0% +it more you can be even one plus Epsilon +Lambda bits to lamb you can play with it + + align:start position:0% +Lambda bits to lamb you can play with it + + + align:start position:0% +Lambda bits to lamb you can play with it +but let's say two Lambda to Lambda + + align:start position:0% +but let's say two Lambda to Lambda + + + align:start position:0% +but let's say two Lambda to Lambda +bits and we construct from it a hash + + align:start position:0% +bits and we construct from it a hash + + + align:start position:0% +bits and we construct from it a hash +function with local opening so let me + + align:start position:0% +function with local opening so let me + + + align:start position:0% +function with local opening so let me +tell you exactly what this hash function + + align:start position:0% +tell you exactly what this hash function + + + align:start position:0% +tell you exactly what this hash function +with local opening what it looks like so + + align:start position:0% +with local opening what it looks like so + + + align:start position:0% +with local opening what it looks like so +that then the hash key is exactly the + + align:start position:0% +that then the hash key is exactly the + + + align:start position:0% +that then the hash key is exactly the +same as before we take the same hash key + + align:start position:0% +same as before we take the same hash key + + + align:start position:0% +same as before we take the same hash key +as our underlying so first we started + + align:start position:0% +as our underlying so first we started + + + align:start position:0% +as our underlying so first we started +with a hash we started with this hash + + align:start position:0% +with a hash we started with this hash + + + align:start position:0% +with a hash we started with this hash +family what is it last time we saw we + + align:start position:0% +family what is it last time we saw we + + + align:start position:0% +family what is it last time we saw we +can take for example I gave an example + + align:start position:0% +can take for example I gave an example + + + align:start position:0% +can take for example I gave an example +with this discrete log but you can even + + align:start position:0% +with this discrete log but you can even + + + align:start position:0% +with this discrete log but you can even +if you don't remember it doesn't matter + + align:start position:0% +if you don't remember it doesn't matter + + + align:start position:0% +if you don't remember it doesn't matter +take think of it someone gave you a hash + + align:start position:0% +take think of it someone gave you a hash + + + align:start position:0% +take think of it someone gave you a hash +family with this domain and range okay + + align:start position:0% +family with this domain and range okay + + + align:start position:0% +family with this domain and range okay +now I'm gonna do a domain extension I'm + + align:start position:0% +now I'm gonna do a domain extension I'm + + + align:start position:0% +now I'm gonna do a domain extension I'm +going to make the domain much bigger and + + align:start position:0% +going to make the domain much bigger and + + + align:start position:0% +going to make the domain much bigger and +get local opening how do I do it so this + + align:start position:0% +get local opening how do I do it so this + + + align:start position:0% +get local opening how do I do it so this +is the miracle hash + + align:start position:0% +is the miracle hash + + + align:start position:0% +is the miracle hash +construction the idea is so the Gen is + + align:start position:0% +construction the idea is so the Gen is + + + align:start position:0% +construction the idea is so the Gen is +as I said just generate the same hash + + align:start position:0% +as I said just generate the same hash + + + align:start position:0% +as I said just generate the same hash +key as the original gen no change to the + + align:start position:0% +key as the original gen no change to the + + + align:start position:0% +key as the original gen no change to the +Gen algorithm the eval algorithm on the + + align:start position:0% +Gen algorithm the eval algorithm on the + + + align:start position:0% +Gen algorithm the eval algorithm on the +other end of course changes because the + + align:start position:0% +other end of course changes because the + + + align:start position:0% +other end of course changes because the +domain is much bigger okay it takes + + align:start position:0% +domain is much bigger okay it takes + + + align:start position:0% +domain is much bigger okay it takes +strings of size at most two to the L + + align:start position:0% +strings of size at most two to the L + + + align:start position:0% +strings of size at most two to the L +bits and what does it do so what it does + + align:start position:0% +bits and what does it do so what it does + + + align:start position:0% +bits and what does it do so what it does +is the following it takes his input X + + align:start position:0% +is the following it takes his input X + + + align:start position:0% +is the following it takes his input X +let's suppose for Simplicity that X is + + align:start position:0% +let's suppose for Simplicity that X is + + + align:start position:0% +let's suppose for Simplicity that X is +exactly kind of 2 the L time Lambda + + align:start position:0% +exactly kind of 2 the L time Lambda + + + align:start position:0% +exactly kind of 2 the L time Lambda +bits + + align:start position:0% +bits + + + align:start position:0% +bits +okay a so it's uh you don't have to + + align:start position:0% +okay a so it's uh you don't have to + + + align:start position:0% +okay a so it's uh you don't have to +assume this this is just easy to assume + + align:start position:0% +assume this this is just easy to assume + + + align:start position:0% +assume this this is just easy to assume +and you can always get it with padding + + align:start position:0% +and you can always get it with padding + + + align:start position:0% +and you can always get it with padding +kind of take any input and Pad it so + + align:start position:0% +kind of take any input and Pad it so + + + align:start position:0% +kind of take any input and Pad it so +it'll be of this form and I'll hash it + + align:start position:0% +it'll be of this form and I'll hash it + + + align:start position:0% +it'll be of this form and I'll hash it +okay I I'll say a word if it's not of + + align:start position:0% +okay I I'll say a word if it's not of + + + align:start position:0% +okay I I'll say a word if it's not of +this form uh but if it is of this form + + align:start position:0% +this form uh but if it is of this form + + + align:start position:0% +this form uh but if it is of this form +what do you do you take your input X + + align:start position:0% +what do you do you take your input X + + + align:start position:0% +what do you do you take your input X +just partition it to blocks each of + + align:start position:0% +just partition it to blocks each of + + + align:start position:0% +just partition it to blocks each of +length Lambda so you have two to the L + + align:start position:0% +length Lambda so you have two to the L + + + align:start position:0% +length Lambda so you have two to the L +blocks okay you have an input X of + + align:start position:0% +blocks okay you have an input X of + + + align:start position:0% +blocks okay you have an input X of +length two to the L * Lambda you + + align:start position:0% +length two to the L * Lambda you + + + align:start position:0% +length two to the L * Lambda you +partition it to chunks each of length + + align:start position:0% +partition it to chunks each of length + + + align:start position:0% +partition it to chunks each of length +Lambda so you have two to the L chunks + + align:start position:0% +Lambda so you have two to the L chunks + + + align:start position:0% +Lambda so you have two to the L chunks +let's call the chunks X1 X2 X3 X4 and so + + align:start position:0% +let's call the chunks X1 X2 X3 X4 and so + + + align:start position:0% +let's call the chunks X1 X2 X3 X4 and so +on up to X2 to the Lambda each of them + + align:start position:0% +on up to X2 to the Lambda each of them + + + align:start position:0% +on up to X2 to the Lambda each of them +up to X2 to the L + + align:start position:0% +up to X2 to the L + + + align:start position:0% +up to X2 to the L +sorry each of them of length Lambda and + + align:start position:0% +sorry each of them of length Lambda and + + + align:start position:0% +sorry each of them of length Lambda and +now what you do you take two blocks this + + align:start position:0% +now what you do you take two blocks this + + + align:start position:0% +now what you do you take two blocks this +is two Lambda bits and hash it using our + + align:start position:0% +is two Lambda bits and hash it using our + + + align:start position:0% +is two Lambda bits and hash it using our +building block hash that takes 2 Lambda + + align:start position:0% +building block hash that takes 2 Lambda + + + align:start position:0% +building block hash that takes 2 Lambda +to Lambda you take the to Lambda you + + align:start position:0% +to Lambda you take the to Lambda you + + + align:start position:0% +to Lambda you take the to Lambda you +hash you take these two you hash so in + + align:start position:0% +hash you take these two you hash so in + + + align:start position:0% +hash you take these two you hash so in +other words you take the two to the L + + align:start position:0% +other words you take the two to the L + + + align:start position:0% +other words you take the two to the L +blocks to two to the L minus one blocks + + align:start position:0% +blocks to two to the L minus one blocks + + + align:start position:0% +blocks to two to the L minus one blocks +you hash every every pair you hash every + + align:start position:0% +you hash every every pair you hash every + + + align:start position:0% +you hash every every pair you hash every +pair you hash every pair you hash every + + align:start position:0% +pair you hash every pair you hash every + + + align:start position:0% +pair you hash every pair you hash every +pair you hash you got two to the L minus + + align:start position:0% +pair you hash you got two to the L minus + + + align:start position:0% +pair you hash you got two to the L minus +one blocks then you take these blocks + + align:start position:0% +one blocks then you take these blocks + + + align:start position:0% +one blocks then you take these blocks +and again every pair you hash every pair + + align:start position:0% +and again every pair you hash every pair + + + align:start position:0% +and again every pair you hash every pair +you hash every pair two to the L minus + + align:start position:0% +you hash every pair two to the L minus + + + align:start position:0% +you hash every pair two to the L minus +two blocks and so on for so forth until + + align:start position:0% +two blocks and so on for so forth until + + + align:start position:0% +two blocks and so on for so forth until +you arrive to one block at the end + + align:start position:0% +you arrive to one block at the end + + + align:start position:0% +you arrive to one block at the end +what do you output you output the top + + align:start position:0% +what do you output you output the top + + + align:start position:0% +what do you output you output the top +the final I guess it's going to be + + align:start position:0% +the final I guess it's going to be + + + align:start position:0% +the final I guess it's going to be +somewhere + + align:start position:0% +somewhere + + + align:start position:0% +somewhere +here uh block which is often called a + + align:start position:0% +here uh block which is often called a + + + align:start position:0% +here uh block which is often called a +root you output the root and you output + + align:start position:0% +root you output the root and you output + + + align:start position:0% +root you output the root and you output +the depth of the + + align:start position:0% +the depth of the + + + align:start position:0% +the depth of the +tree okay that's the output of the hash + + align:start position:0% +tree okay that's the output of the hash + + + align:start position:0% +tree okay that's the output of the hash +so the output is the root the hash value + + align:start position:0% +so the output is the root the hash value + + + align:start position:0% +so the output is the root the hash value +here it's Lambda + + align:start position:0% +here it's Lambda + + + align:start position:0% +here it's Lambda +bits and D which you also think of it as + + align:start position:0% +bits and D which you also think of it as + + + align:start position:0% +bits and D which you also think of it as +being Lambda bits even if it's less just + + align:start position:0% +being Lambda bits even if it's less just + + + align:start position:0% +being Lambda bits even if it's less just +encoded using Lambda bits so if you're + + align:start position:0% +encoded using Lambda bits so if you're + + + align:start position:0% +encoded using Lambda bits so if you're +mad now at me because I promise you + + align:start position:0% +mad now at me because I promise you + + + align:start position:0% +mad now at me because I promise you +Lambda bits and you see here two Lambda + + align:start position:0% +Lambda bits and you see here two Lambda + + + align:start position:0% +Lambda bits and you see here two Lambda +bits apply this hash one more time and + + align:start position:0% +bits apply this hash one more time and + + + align:start position:0% +bits apply this hash one more time and +you'll get your Lambda + + align:start position:0% +you'll get your Lambda + + + align:start position:0% +you'll get your Lambda +bits okay but how two Lambda bits is + + align:start position:0% +bits okay but how two Lambda bits is + + + align:start position:0% +bits okay but how two Lambda bits is +also fine yeah um why are we Bing the + + align:start position:0% +also fine yeah um why are we Bing the + + + align:start position:0% +also fine yeah um why are we Bing the +input L to two to the Lambda instead of + + align:start position:0% +input L to two to the Lambda instead of + + + align:start position:0% +input L to two to the Lambda instead of +just arbitrary good good good good good + + align:start position:0% +just arbitrary good good good good good + + + align:start position:0% +just arbitrary good good good good good +great because last time great question + + align:start position:0% +great because last time great question + + + align:start position:0% +great because last time great question +so last time when I mention I said oh + + align:start position:0% +so last time when I mention I said oh + + + align:start position:0% +so last time when I mention I said oh +just take STAR here anything so why am I + + align:start position:0% +just take STAR here anything so why am I + + + align:start position:0% +just take STAR here anything so why am I +why am I bounding out to to the Lambda + + align:start position:0% +why am I bounding out to to the Lambda + + + align:start position:0% +why am I bounding out to to the Lambda +so this construction bounds two to the + + align:start position:0% +so this construction bounds two to the + + + align:start position:0% +so this construction bounds two to the +Lambda because as you I take every + + align:start position:0% +Lambda because as you I take every + + + align:start position:0% +Lambda because as you I take every +Lambda I can't take that's all it gives + + align:start position:0% +Lambda I can't take that's all it gives + + + align:start position:0% +Lambda I can't take that's all it gives +me so that's all I get now you can say + + align:start position:0% +me so that's all I get now you can say + + + align:start position:0% +me so that's all I get now you can say +wait what if I want more maybe I more + + align:start position:0% +wait what if I want more maybe I more + + + align:start position:0% +wait what if I want more maybe I more +than two Lambda you can actually get + + align:start position:0% +than two Lambda you can actually get + + + align:start position:0% +than two Lambda you can actually get +more than two to the Lambda for example + + align:start position:0% +more than two to the Lambda for example + + + align:start position:0% +more than two to the Lambda for example +you can bootstrap this so now you can + + align:start position:0% +you can bootstrap this so now you can + + + align:start position:0% +you can bootstrap this so now you can +take two to the Lambda to Lambda you can + + align:start position:0% +take two to the Lambda to Lambda you can + + + align:start position:0% +take two to the Lambda to Lambda you can +kind of create a Merkel hash of this + + align:start position:0% +kind of create a Merkel hash of this + + + align:start position:0% +kind of create a Merkel hash of this +Merkel hash you know you can kind of uh + + align:start position:0% +Merkel hash you know you can kind of uh + + + align:start position:0% +Merkel hash you know you can kind of uh +uh but actually you never it doesn't + + align:start position:0% +uh but actually you never it doesn't + + + align:start position:0% +uh but actually you never it doesn't +come up because you never need to two to + + align:start position:0% +come up because you never need to two to + + + align:start position:0% +come up because you never need to two to +Lambda is like nothing is more than two + + align:start position:0% +Lambda is like nothing is more than two + + + align:start position:0% +Lambda is like nothing is more than two +to we choose Lambda to in our world + + align:start position:0% +to we choose Lambda to in our world + + + align:start position:0% +to we choose Lambda to in our world +nothing is more than size two to the + + align:start position:0% +nothing is more than size two to the + + + align:start position:0% +nothing is more than size two to the +Lambda but you can think of like um you + + align:start position:0% +Lambda but you can think of like um you + + + align:start position:0% +Lambda but you can think of like um you +you can get if you just as a kind of + + align:start position:0% +you can get if you just as a kind of + + + align:start position:0% +you can get if you just as a kind of +mathematical curiosity you can uh apply + + align:start position:0% +mathematical curiosity you can uh apply + + + align:start position:0% +mathematical curiosity you can uh apply +it you know so once you have from two to + + align:start position:0% +it you know so once you have from two to + + + align:start position:0% +it you know so once you have from two to +the Lambda to Lambda you + + align:start position:0% +the Lambda to Lambda you + + + align:start position:0% +the Lambda to Lambda you +can chop your things to two to the + + align:start position:0% +can chop your things to two to the + + + align:start position:0% +can chop your things to two to the +Lambda and and do this kind of use this + + align:start position:0% +Lambda and and do this kind of use this + + + align:start position:0% +Lambda and and do this kind of use this +as a building block to a bigger morle + + align:start position:0% +as a building block to a bigger morle + + + align:start position:0% +as a building block to a bigger morle +high so you can kind of amplify it you + + align:start position:0% +high so you can kind of amplify it you + + + align:start position:0% +high so you can kind of amplify it you +know uh but we're not for us 2 to the + + align:start position:0% +know uh but we're not for us 2 to the + + + align:start position:0% +know uh but we're not for us 2 to the +Lambda to Lambda is good enough great + + align:start position:0% +Lambda to Lambda is good enough great + + + align:start position:0% +Lambda to Lambda is good enough great +great question + + align:start position:0% + + + + align:start position:0% + +any any other question yes why does the + + align:start position:0% +any any other question yes why does the + + + align:start position:0% +any any other question yes why does the +need to be included in the like should + + align:start position:0% +need to be included in the like should + + + align:start position:0% +need to be included in the like should +it not just be a function of the left of + + align:start position:0% +it not just be a function of the left of + + + align:start position:0% +it not just be a function of the left of +X ah good great great question why do + + align:start position:0% +X ah good great great question why do + + + align:start position:0% +X ah good great great question why do +why do I insist on including D is it not + + align:start position:0% +why do I insist on including D is it not + + + align:start position:0% +why do I insist on including D is it not +a function of X it is a function of X + + align:start position:0% +a function of X it is a function of X + + + align:start position:0% +a function of X it is a function of X +it's a deterministic function of the L + + align:start position:0% +it's a deterministic function of the L + + + align:start position:0% +it's a deterministic function of the L +not even X of the length of X yes + + align:start position:0% +not even X of the length of X yes + + + align:start position:0% +not even X of the length of X yes +however nobody knows what x is so you + + align:start position:0% +however nobody knows what x is so you + + + align:start position:0% +however nobody knows what x is so you +know at the end of the day I want + + align:start position:0% +know at the end of the day I want + + + align:start position:0% +know at the end of the day I want +Collision resistance and so the property + + align:start position:0% +Collision resistance and so the property + + + align:start position:0% +Collision resistance and so the property +we want from this hash is that it's + + align:start position:0% +we want from this hash is that it's + + + align:start position:0% +we want from this hash is that it's +Collision resistance what does Collision + + align:start position:0% +Collision resistance what does Collision + + + align:start position:0% +Collision resistance what does Collision +resistant means it means that you cannot + + align:start position:0% +resistant means it means that you cannot + + + align:start position:0% +resistant means it means that you cannot +output a hash value with two different + + align:start position:0% +output a hash value with two different + + + align:start position:0% +output a hash value with two different +openings now when you outut a has value + + align:start position:0% +openings now when you outut a has value + + + align:start position:0% +openings now when you outut a has value +nobody knows what the x is actually you + + align:start position:0% +nobody knows what the x is actually you + + + align:start position:0% +nobody knows what the x is actually you +may not even know well if + + align:start position:0% +may not even know well if + + + align:start position:0% +may not even know well if +you um okay when you open you know but + + align:start position:0% +you um okay when you open you know but + + + align:start position:0% +you um okay when you open you know but +uh you know when you give someone a hash + + align:start position:0% +uh you know when you give someone a hash + + + align:start position:0% +uh you know when you give someone a hash +value there's no X + + align:start position:0% +value there's no X + + + align:start position:0% +value there's no X +inherently a part of it if you don't + + align:start position:0% +inherently a part of it if you don't + + + align:start position:0% +inherently a part of it if you don't +include the dep actually there's an + + align:start position:0% +include the dep actually there's an + + + align:start position:0% +include the dep actually there's an +attack it's not collig resistance it's + + align:start position:0% +attack it's not collig resistance it's + + + align:start position:0% +attack it's not collig resistance it's +really not it's not just a why is it not + + align:start position:0% +really not it's not just a why is it not + + + align:start position:0% +really not it's not just a why is it not +Collision resistance for example just as + + align:start position:0% +Collision resistance for example just as + + + align:start position:0% +Collision resistance for example just as +an attack let's say I publish this route + + align:start position:0% +an attack let's say I publish this route + + + align:start position:0% +an attack let's say I publish this route +even this is my root okay this is my + + align:start position:0% +even this is my root okay this is my + + + align:start position:0% +even this is my root okay this is my +input my input is X1 X2 X3 X4 and the + + align:start position:0% +input my input is X1 X2 X3 X4 and the + + + align:start position:0% +input my input is X1 X2 X3 X4 and the +output is root now let me break the + + align:start position:0% +output is root now let me break the + + + align:start position:0% +output is root now let me break the +Collision resistance I'll give you two + + align:start position:0% +Collision resistance I'll give you two + + + align:start position:0% +Collision resistance I'll give you two +different openings one is X1 X2 X3 X4 + + align:start position:0% +different openings one is X1 X2 X3 X4 + + + align:start position:0% +different openings one is X1 X2 X3 X4 +you do the hash you see yeah you're + + align:start position:0% +you do the hash you see yeah you're + + + align:start position:0% +you do the hash you see yeah you're +happy it's a good opening now let me + + align:start position:0% +happy it's a good opening now let me + + + align:start position:0% +happy it's a good opening now let me +give you another opening just this and + + align:start position:0% +give you another opening just this and + + + align:start position:0% +give you another opening just this and +this that's also a good open opening so + + align:start position:0% +this that's also a good open opening so + + + align:start position:0% +this that's also a good open opening so +I open it in two different + + align:start position:0% +I open it in two different + + + align:start position:0% +I open it in two different +ways that's not okay that's a collision + + align:start position:0% +ways that's not okay that's a collision + + + align:start position:0% +ways that's not okay that's a collision +if you include D however then so that's + + align:start position:0% +if you include D however then so that's + + + align:start position:0% +if you include D however then so that's +exactly what will allow me to argue + + align:start position:0% +exactly what will allow me to argue + + + align:start position:0% +exactly what will allow me to argue +Collision resistance it's this D great + + align:start position:0% +Collision resistance it's this D great + + + align:start position:0% +Collision resistance it's this D great +question thank you any so so this is the + + align:start position:0% +question thank you any so so this is the + + + align:start position:0% +question thank you any so so this is the +construction + + align:start position:0% +construction + + + align:start position:0% +construction +questions okay let's see how do we open + + align:start position:0% +questions okay let's see how do we open + + + align:start position:0% +questions okay let's see how do we open +so now this is this is just so far great + + align:start position:0% +so now this is this is just so far great + + + align:start position:0% +so now this is this is just so far great +we managed to go from two to the Lambda + + align:start position:0% +we managed to go from two to the Lambda + + + align:start position:0% +we managed to go from two to the Lambda +to Lambda I didn't argue Collision resen + + align:start position:0% +to Lambda I didn't argue Collision resen + + + align:start position:0% +to Lambda I didn't argue Collision resen +but at least we did domain extension so + + align:start position:0% +but at least we did domain extension so + + + align:start position:0% +but at least we did domain extension so +we extended the domain but I also want + + align:start position:0% +we extended the domain but I also want + + + align:start position:0% +we extended the domain but I also want +especially I need it for the killan M + + align:start position:0% +especially I need it for the killan M + + + align:start position:0% +especially I need it for the killan M +protocol and for many many other uses in + + align:start position:0% +protocol and for many many other uses in + + + align:start position:0% +protocol and for many many other uses in +cryptography I want to be able to do + + align:start position:0% +cryptography I want to be able to do + + + align:start position:0% +cryptography I want to be able to do +local opening so remember what does + + align:start position:0% +local opening so remember what does + + + align:start position:0% +local opening so remember what does +local opening mean I may not want to + + align:start position:0% +local opening mean I may not want to + + + align:start position:0% +local opening mean I may not want to +open when with I may not want to give + + align:start position:0% +open when with I may not want to give + + + align:start position:0% +open when with I may not want to give +you my entire + + align:start position:0% +you my entire + + + align:start position:0% +you my entire +input I may just want to give you to + + align:start position:0% +input I may just want to give you to + + + align:start position:0% +input I may just want to give you to +convince you that this hash value in + + align:start position:0% +convince you that this hash value in + + + align:start position:0% +convince you that this hash value in +some location I of the of the of the + + align:start position:0% +some location I of the of the of the + + + align:start position:0% +some location I of the of the of the +input the value is some bit B but I + + align:start position:0% +input the value is some bit B but I + + + align:start position:0% +input the value is some bit B but I +don't want to give you the entire + + align:start position:0% +don't want to give you the entire + + + align:start position:0% +don't want to give you the entire +because the entire input is gigantic you + + align:start position:0% +because the entire input is gigantic you + + + align:start position:0% +because the entire input is gigantic you +can't even hold it so I want kind of a + + align:start position:0% +can't even hold it so I want kind of a + + + align:start position:0% +can't even hold it so I want kind of a +succinct opener I want to convince you + + align:start position:0% +succinct opener I want to convince you + + + align:start position:0% +succinct opener I want to convince you +in a kind of a very succinct way that + + align:start position:0% +in a kind of a very succinct way that + + + align:start position:0% +in a kind of a very succinct way that +what's sitting here in this bit is zero + + align:start position:0% +what's sitting here in this bit is zero + + + align:start position:0% +what's sitting here in this bit is zero +or it's one so how do I do it so this um + + align:start position:0% +or it's one so how do I do it so this um + + + align:start position:0% +or it's one so how do I do it so this um +a uh construction is actually really + + align:start position:0% +a uh construction is actually really + + + align:start position:0% +a uh construction is actually really +nice it gives you a local opening in a + + align:start position:0% +nice it gives you a local opening in a + + + align:start position:0% +nice it gives you a local opening in a +very nice way so what's the local + + align:start position:0% +very nice way so what's the local + + + align:start position:0% +very nice way so what's the local +opening suppose I want to open this kind + + align:start position:0% +opening suppose I want to open this kind + + + align:start position:0% +opening suppose I want to open this kind +of the bit here sitting here what I'm + + align:start position:0% +of the bit here sitting here what I'm + + + align:start position:0% +of the bit here sitting here what I'm +going to do I'm going to actually give + + align:start position:0% +going to do I'm going to actually give + + + align:start position:0% +going to do I'm going to actually give +you this entire Block it's only L the + + align:start position:0% +you this entire Block it's only L the + + + align:start position:0% +you this entire Block it's only L the +bit so it's not that big okay I give you + + align:start position:0% +bit so it's not that big okay I give you + + + align:start position:0% +bit so it's not that big okay I give you +this block what do you do with it so let + + align:start position:0% +this block what do you do with it so let + + + align:start position:0% +this block what do you do with it so let +me help you convince you that this block + + align:start position:0% +me help you convince you that this block + + + align:start position:0% +me help you convince you that this block +is indeed the block related to the root + + align:start position:0% +is indeed the block related to the root + + + align:start position:0% +is indeed the block related to the root +namely it's the it's the block that + + align:start position:0% +namely it's the it's the block that + + + align:start position:0% +namely it's the it's the block that +indeed sits here next to how do I + + align:start position:0% +indeed sits here next to how do I + + + align:start position:0% +indeed sits here next to how do I +convince + + align:start position:0% +convince + + + align:start position:0% +convince +you I give you the sibling so this block + + align:start position:0% +you I give you the sibling so this block + + + align:start position:0% +you I give you the sibling so this block +has a parent I give you the sibling and + + align:start position:0% +has a parent I give you the sibling and + + + align:start position:0% +has a parent I give you the sibling and +the + + align:start position:0% +the + + + align:start position:0% +the +parent this parent has a parent I give + + align:start position:0% +parent this parent has a parent I give + + + align:start position:0% +parent this parent has a parent I give +you the sibling and the parent and so on + + align:start position:0% +you the sibling and the parent and so on + + + align:start position:0% +you the sibling and the parent and so on +so forth until you get to the root I + + align:start position:0% +so forth until you get to the root I + + + align:start position:0% +so forth until you get to the root I +give you all these blocks so in each + + align:start position:0% +give you all these blocks so in each + + + align:start position:0% +give you all these blocks so in each +layer I open two blocks which are the + + align:start position:0% +layer I open two blocks which are the + + + align:start position:0% +layer I open two blocks which are the +two siblings so I open two siblings you + + align:start position:0% +two siblings so I open two siblings you + + + align:start position:0% +two siblings so I open two siblings you +get this I open the two siblings you get + + align:start position:0% +get this I open the two siblings you get + + + align:start position:0% +get this I open the two siblings you get +this I open the twoing and so on + + align:start position:0% +this I open the twoing and so on + + + align:start position:0% +this I open the twoing and so on +yes so I don't know if it matters but + + align:start position:0% +yes so I don't know if it matters but + + + align:start position:0% +yes so I don't know if it matters but +you strictly you to return the ancestors + + align:start position:0% +you strictly you to return the ancestors + + + align:start position:0% +you strictly you to return the ancestors +you can only return the sit ons right + + align:start position:0% +you can only return the sit ons right + + + align:start position:0% +you can only return the sit ons right +good good good right right right you're + + align:start position:0% +good good good right right right you're + + + align:start position:0% +good good good right right right you're +totally right you're saying well if you + + align:start position:0% +totally right you're saying well if you + + + align:start position:0% +totally right you're saying well if you +really want to be what you're saying + + align:start position:0% +really want to be what you're saying + + + align:start position:0% +really want to be what you're saying +which is completely right thing this is + + align:start position:0% +which is completely right thing this is + + + align:start position:0% +which is completely right thing this is +wasteful because actually all I need to + + align:start position:0% +wasteful because actually all I need to + + + align:start position:0% +wasteful because actually all I need to +give you is the sibling so why waste + + align:start position:0% +give you is the sibling so why waste + + + align:start position:0% +give you is the sibling so why waste +communication I if I want to open this + + align:start position:0% +communication I if I want to open this + + + align:start position:0% +communication I if I want to open this +I'll give you this and this sibling I + + align:start position:0% +I'll give you this and this sibling I + + + align:start position:0% +I'll give you this and this sibling I +don't need to give you this you can + + align:start position:0% +don't need to give you this you can + + + align:start position:0% +don't need to give you this you can +compute this on your own so compute this + + align:start position:0% +compute this on your own so compute this + + + align:start position:0% +compute this on your own so compute this +on your own I'll give you this I don't + + align:start position:0% +on your own I'll give you this I don't + + + align:start position:0% +on your own I'll give you this I don't +need to give you this you have these two + + align:start position:0% +need to give you this you have these two + + + align:start position:0% +need to give you this you have these two +so complet it on this on your own and + + align:start position:0% +so complet it on this on your own and + + + align:start position:0% +so complet it on this on your own and +then I'll only give you this and then + + align:start position:0% +then I'll only give you this and then + + + align:start position:0% +then I'll only give you this and then +and so on you're 100% correct I actually + + align:start position:0% +and so on you're 100% correct I actually + + + align:start position:0% +and so on you're 100% correct I actually +just need to give you + + align:start position:0% +just need to give you + + + align:start position:0% +just need to give you +one okay I wrote two because it's just + + align:start position:0% +one okay I wrote two because it's just + + + align:start position:0% +one okay I wrote two because it's just +easier to say something but yes exactly + + align:start position:0% +easier to say something but yes exactly + + + align:start position:0% +easier to say something but yes exactly +one is enough and you can compute the + + align:start position:0% +one is enough and you can compute the + + + align:start position:0% +one is enough and you can compute the +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +fantastic uh so that's the so I I I + + align:start position:0% +fantastic uh so that's the so I I I + + + align:start position:0% +fantastic uh so that's the so I I I +denoted by so what does the open do it + + align:start position:0% +denoted by so what does the open do it + + + align:start position:0% +denoted by so what does the open do it +gives you for each layer it gives you + + align:start position:0% +gives you for each layer it gives you + + + align:start position:0% +gives you for each layer it gives you +two blocks for layer J denoted by ZJ so + + align:start position:0% +two blocks for layer J denoted by ZJ so + + + align:start position:0% +two blocks for layer J denoted by ZJ so +ZJ is two blocks okay there's on the + + align:start position:0% +ZJ is two blocks okay there's on the + + + align:start position:0% +ZJ is two blocks okay there's on the +leaves it's two blocks J equal zero it's + + align:start position:0% +leaves it's two blocks J equal zero it's + + + align:start position:0% +leaves it's two blocks J equal zero it's +on the leaf layer one layer two up to + + align:start position:0% +on the leaf layer one layer two up to + + + align:start position:0% +on the leaf layer one layer two up to +layer D it's actually just the root so + + align:start position:0% +layer D it's actually just the root so + + + align:start position:0% +layer D it's actually just the root so +you don't you can actually go to D minus + + align:start position:0% +you don't you can actually go to D minus + + + align:start position:0% +you don't you can actually go to D minus +one if you want okay but I I'll just in + + align:start position:0% +one if you want okay but I I'll just in + + + align:start position:0% +one if you want okay but I I'll just in +in my mind I want to include the root + + align:start position:0% +in my mind I want to include the root + + + align:start position:0% +in my mind I want to include the root +it's just you'll the reason I include + + align:start position:0% +it's just you'll the reason I include + + + align:start position:0% +it's just you'll the reason I include +both and the root is now when I analyze + + align:start position:0% +both and the root is now when I analyze + + + align:start position:0% +both and the root is now when I analyze +it it's notation wise it's just very + + align:start position:0% +it it's notation wise it's just very + + + align:start position:0% +it it's notation wise it's just very +very easy but really it's enough like + + align:start position:0% +very easy but really it's enough like + + + align:start position:0% +very easy but really it's enough like +you said to have the sibling and the + + align:start position:0% +you said to have the sibling and the + + + align:start position:0% +you said to have the sibling and the +roots of course you don't need to + + align:start position:0% +roots of course you don't need to + + + align:start position:0% +roots of course you don't need to +give okay but let's just think this is + + align:start position:0% +give okay but let's just think this is + + + align:start position:0% +give okay but let's just think this is +how I open and now how do I + + align:start position:0% +how I open and now how do I + + + align:start position:0% +how I open and now how do I +verify I just take each two sibling + + align:start position:0% +verify I just take each two sibling + + + align:start position:0% +verify I just take each two sibling +compute the hash and make sure it + + align:start position:0% +compute the hash and make sure it + + + align:start position:0% +compute the hash and make sure it +corresponds to the relevant the relevant + + align:start position:0% +corresponds to the relevant the relevant + + + align:start position:0% +corresponds to the relevant the relevant +Z is indeed uh the parent so again you + + align:start position:0% +Z is indeed uh the parent so again you + + + align:start position:0% +Z is indeed uh the parent so again you +gave me all these things I compute these + + align:start position:0% +gave me all these things I compute these + + + align:start position:0% +gave me all these things I compute these +two I check that it's consistent with + + align:start position:0% +two I check that it's consistent with + + + align:start position:0% +two I check that it's consistent with +the what you gave you if you didn't give + + align:start position:0% +the what you gave you if you didn't give + + + align:start position:0% +the what you gave you if you didn't give +me fine I'll compute on my own I get + + align:start position:0% +me fine I'll compute on my own I get + + + align:start position:0% +me fine I'll compute on my own I get +this I'll compute this and give and then + + align:start position:0% +this I'll compute this and give and then + + + align:start position:0% +this I'll compute this and give and then +they'll check that all I need to check + + align:start position:0% +they'll check that all I need to check + + + align:start position:0% +they'll check that all I need to check +it then is consistency with the + + align:start position:0% +it then is consistency with the + + + align:start position:0% +it then is consistency with the +root okay that the + + align:start position:0% + + + + align:start position:0% + +verification question about the design + + align:start position:0% +verification question about the design + + + align:start position:0% +verification question about the design +the the + + align:start position:0% + + + + align:start position:0% + +algorithms okay so this is kind of where + + align:start position:0% +algorithms okay so this is kind of where + + + align:start position:0% +algorithms okay so this is kind of where +we left off actually last time and what + + align:start position:0% +we left off actually last time and what + + + align:start position:0% +we left off actually last time and what +I want to do now is do the Collision + + align:start position:0% +I want to do now is do the Collision + + + align:start position:0% +I want to do now is do the Collision +resistance I'm happy that actually we + + align:start position:0% +resistance I'm happy that actually we + + + align:start position:0% +resistance I'm happy that actually we +got a chance to do it again because it's + + align:start position:0% +got a chance to do it again because it's + + + align:start position:0% +got a chance to do it again because it's +a very important primitive so it's worth + + align:start position:0% +a very important primitive so it's worth + + + align:start position:0% +a very important primitive so it's worth +kind of having it ingrained in your mind + + align:start position:0% +kind of having it ingrained in your mind + + + align:start position:0% +kind of having it ingrained in your mind +a okay so why why is it collagen + + align:start position:0% +a okay so why why is it collagen + + + align:start position:0% +a okay so why why is it collagen +resistant + + align:start position:0% + + + + align:start position:0% + +so to prove Collision resistance what do + + align:start position:0% +so to prove Collision resistance what do + + + align:start position:0% +so to prove Collision resistance what do +we want to argue that an adversary + + align:start position:0% +we want to argue that an adversary + + + align:start position:0% +we want to argue that an adversary +that's given a hash key cannot produce a + + align:start position:0% +that's given a hash key cannot produce a + + + align:start position:0% +that's given a hash key cannot produce a +hash value namely root and D with two + + align:start position:0% +hash value namely root and D with two + + + align:start position:0% +hash value namely root and D with two +different + + align:start position:0% +different + + + align:start position:0% +different +openings okay so + + align:start position:0% + + + + align:start position:0% + +Suppose there + + align:start position:0% +Suppose there + + + align:start position:0% +Suppose there +exists a poly + + align:start position:0% + + + + align:start position:0% + +size adversary that does find the + + align:start position:0% +size adversary that does find the + + + align:start position:0% +size adversary that does find the +Collision okay such that the probability + + align:start position:0% +Collision okay such that the probability + + + align:start position:0% +Collision okay such that the probability +that a he gets a hash key hash key is + + align:start position:0% +that a he gets a hash key hash key is + + + align:start position:0% +that a he gets a hash key hash key is +from + + align:start position:0% + + + + align:start position:0% + +gen and somehow he manages to Output a + + align:start position:0% +gen and somehow he manages to Output a + + + align:start position:0% +gen and somehow he manages to Output a +hash value which is root and D that's + + align:start position:0% +hash value which is root and D that's + + + align:start position:0% +hash value which is root and D that's +just a hash + + align:start position:0% +just a hash + + + align:start position:0% +just a hash +value and he gives me some + + align:start position:0% +value and he gives me some + + + align:start position:0% +value and he gives me some +index uh I and he managed to open it in + + align:start position:0% +index uh I and he managed to open it in + + + align:start position:0% +index uh I and he managed to open it in +two different way he gives me an open + + align:start position:0% +two different way he gives me an open + + + align:start position:0% +two different way he gives me an open +opening that says oh I is zero and it + + align:start position:0% +opening that says oh I is zero and it + + + align:start position:0% +opening that says oh I is zero and it +gives me another opening that says the I + + align:start position:0% +gives me another opening that says the I + + + align:start position:0% +gives me another opening that says the I +bit is one and such that for both of + + align:start position:0% +bit is one and such that for both of + + + align:start position:0% +bit is one and such that for both of +them such that for every B for both zero + + align:start position:0% +them such that for every B for both zero + + + align:start position:0% +them such that for every B for both zero +and + + align:start position:0% +and + + + align:start position:0% +and +one there will accept there and hash + + align:start position:0% +one there will accept there and hash + + + align:start position:0% +one there will accept there and hash +key uh root and d i and row b outputs + + align:start position:0% +key uh root and d i and row b outputs + + + align:start position:0% +key uh root and d i and row b outputs +one so suppose I have an algorithm + + align:start position:0% +one so suppose I have an algorithm + + + align:start position:0% +one so suppose I have an algorithm +that gives me a hash value an index and + + align:start position:0% +that gives me a hash value an index and + + + align:start position:0% +that gives me a hash value an index and +a valid opening both to zero and to one + + align:start position:0% +a valid opening both to zero and to one + + + align:start position:0% +a valid opening both to zero and to one +valid I mean that the ver will accept + + align:start position:0% +valid I mean that the ver will accept + + + align:start position:0% +valid I mean that the ver will accept +both of them oh sorry + + align:start position:0% +both of them oh sorry + + + align:start position:0% +both of them oh sorry +B so ver takes hash key a value an index + + align:start position:0% +B so ver takes hash key a value an index + + + align:start position:0% +B so ver takes hash key a value an index +I and a b bit B saying whether index I + + align:start position:0% +I and a b bit B saying whether index I + + + align:start position:0% +I and a b bit B saying whether index I +is zero or one and a proof an + + align:start position:0% +is zero or one and a proof an + + + align:start position:0% +is zero or one and a proof an +opening and suppose he accepts + + align:start position:0% +opening and suppose he accepts + + + align:start position:0% +opening and suppose he accepts +both suppose he accepts both with + + align:start position:0% +both suppose he accepts both with + + + align:start position:0% +both suppose he accepts both with +probability at least I know + + align:start position:0% +probability at least I know + + + align:start position:0% +probability at least I know +Epsilon okay so Suppose there exist an + + align:start position:0% +Epsilon okay so Suppose there exist an + + + align:start position:0% +Epsilon okay so Suppose there exist an +exists + + align:start position:0% + + + + align:start position:0% + +Epsilon so Suppose there exist epon so + + align:start position:0% +Epsilon so Suppose there exist epon so + + + align:start position:0% +Epsilon so Suppose there exist epon so +that for any L that the probability that + + align:start position:0% +that for any L that the probability that + + + align:start position:0% +that for any L that the probability that +a managed to find the Collision like + + align:start position:0% +a managed to find the Collision like + + + align:start position:0% +a managed to find the Collision like +this is at least Epsilon I'm going to + + align:start position:0% +this is at least Epsilon I'm going to + + + align:start position:0% +this is at least Epsilon I'm going to +argue then then you can find a collision + + align:start position:0% +argue then then you can find a collision + + + align:start position:0% +argue then then you can find a collision +in the underlying H in the small H with + + align:start position:0% +in the underlying H in the small H with + + + align:start position:0% +in the underlying H in the small H with +probability Epsilon + + align:start position:0% +probability Epsilon + + + align:start position:0% +probability Epsilon +okay so if you you if you have an + + align:start position:0% +okay so if you you if you have an + + + align:start position:0% +okay so if you you if you have an +algorithm like this + + align:start position:0% +algorithm like this + + + align:start position:0% +algorithm like this +then there exists an algorithm uh uh + + align:start position:0% +then there exists an algorithm uh uh + + + align:start position:0% +then there exists an algorithm uh uh +poly + + align:start position:0% + + + + align:start position:0% + +size such that + + align:start position:0% +size such that + + + align:start position:0% +size such that +b such that the + + align:start position:0% +b such that the + + + align:start position:0% +b such that the +probability that b he gets hash key the + + align:start position:0% +probability that b he gets hash key the + + + align:start position:0% +probability that b he gets hash key the +probability that he outputs + + align:start position:0% + + + + align:start position:0% + +a I don't know x0 x and x Prime such + + align:start position:0% +a I don't know x0 x and x Prime such + + + align:start position:0% +a I don't know x0 x and x Prime such +that the original eval HK x equals + + align:start position:0% +that the original eval HK x equals + + + align:start position:0% +that the original eval HK x equals +eval hkx Prime and X is different than x + + align:start position:0% +eval hkx Prime and X is different than x + + + align:start position:0% +eval hkx Prime and X is different than x +Prime is at least + + align:start position:0% +Prime is at least + + + align:start position:0% +Prime is at least +Epsilon but we assume that this is + + align:start position:0% +Epsilon but we assume that this is + + + align:start position:0% +Epsilon but we assume that this is +Collision resistance we started with an + + align:start position:0% +Collision resistance we started with an + + + align:start position:0% +Collision resistance we started with an +underlying hash function that's + + align:start position:0% +underlying hash function that's + + + align:start position:0% +underlying hash function that's +Collision resistance so the Epsilon has + + align:start position:0% +Collision resistance so the Epsilon has + + + align:start position:0% +Collision resistance so the Epsilon has +to be + + align:start position:0% + + + + align:start position:0% + +negligible okay that's what we're going + + align:start position:0% +negligible okay that's what we're going + + + align:start position:0% +negligible okay that's what we're going +to show so we're going to use if an + + align:start position:0% +to show so we're going to use if an + + + align:start position:0% +to show so we're going to use if an +adversary can find a coll a local + + align:start position:0% +adversary can find a coll a local + + + align:start position:0% +adversary can find a coll a local +opening that collides for the Merkel + + align:start position:0% +opening that collides for the Merkel + + + align:start position:0% +opening that collides for the Merkel +hash we can use them to actually + + align:start position:0% +hash we can use them to actually + + + align:start position:0% +hash we can use them to actually +break the to find collisions in the + + align:start position:0% +break the to find collisions in the + + + align:start position:0% +break the to find collisions in the +underlying kind of two Lambda to L to + + align:start position:0% +underlying kind of two Lambda to L to + + + align:start position:0% +underlying kind of two Lambda to L to +Lambda uh hash function in the little + + align:start position:0% +Lambda uh hash function in the little + + + align:start position:0% +Lambda uh hash function in the little +hash + + align:start position:0% +hash + + + align:start position:0% +hash +function so how does B work what does B + + align:start position:0% +function so how does B work what does B + + + align:start position:0% +function so how does B work what does B +do B takes it a hash key he just run a + + align:start position:0% +do B takes it a hash key he just run a + + + align:start position:0% +do B takes it a hash key he just run a +so let me so we claim that there exists + + align:start position:0% +so let me so we claim that there exists + + + align:start position:0% +so let me so we claim that there exists +a b so let's see + + align:start position:0% +a b so let's see + + + align:start position:0% +a b so let's see +B an input hash key what does it do just + + align:start position:0% +B an input hash key what does it do just + + + align:start position:0% +B an input hash key what does it do just +run a so get root d i row0 Row + + align:start position:0% +run a so get root d i row0 Row + + + align:start position:0% +run a so get root d i row0 Row +one which is just a and hash + + align:start position:0% +one which is just a and hash + + + align:start position:0% +one which is just a and hash +key now + + align:start position:0% +key now + + + align:start position:0% +key now +he got row zero and Row one what are row + + align:start position:0% +he got row zero and Row one what are row + + + align:start position:0% +he got row zero and Row one what are row +zero Row one each row is this kind of + + align:start position:0% +zero Row one each row is this kind of + + + align:start position:0% +zero Row one each row is this kind of +two uh pairs of siblings I'm going to + + align:start position:0% +two uh pairs of siblings I'm going to + + + align:start position:0% +two uh pairs of siblings I'm going to +assume that both exist because it's just + + align:start position:0% +assume that both exist because it's just + + + align:start position:0% +assume that both exist because it's just +easier for me that's why I wrote both of + + align:start position:0% +easier for me that's why I wrote both of + + + align:start position:0% +easier for me that's why I wrote both of +them so each + + align:start position:0% +them so each + + + align:start position:0% +them so each +opening so row zero is for each level + + align:start position:0% +opening so row zero is for each level + + + align:start position:0% +opening so row zero is for each level +you have + + align:start position:0% +you have + + + align:start position:0% +you have +z0 + + align:start position:0% + + + + align:start position:0% + +J from zero to D and Row + + align:start position:0% + + + + align:start position:0% + +one is let's call it z uh one + + align:start position:0% + + + + align:start position:0% + +J now what do we know in the leaves so + + align:start position:0% +J now what do we know in the leaves so + + + align:start position:0% +J now what do we know in the leaves so +we know that + + align:start position:0% +we know that + + + align:start position:0% +we know that +z0 Z is different than Z One Z the two + + align:start position:0% +z0 Z is different than Z One Z the two + + + align:start position:0% +z0 Z is different than Z One Z the two +leaves are different because in one + + align:start position:0% +leaves are different because in one + + + align:start position:0% +leaves are different because in one +leaf okay suppose suppose verify access + + align:start position:0% +leaf okay suppose suppose verify access + + + align:start position:0% +leaf okay suppose suppose verify access +to both of them in the case that these + + align:start position:0% +to both of them in the case that these + + + align:start position:0% +to both of them in the case that these +are both accepted I'm going to argue + + align:start position:0% +are both accepted I'm going to argue + + + align:start position:0% +are both accepted I'm going to argue +that I found + + align:start position:0% +that I found + + + align:start position:0% +that I found +collisions okay so now suppose row Z and + + align:start position:0% +collisions okay so now suppose row Z and + + + align:start position:0% +collisions okay so now suppose row Z and +Row one are accepted so + + align:start position:0% +Row one are accepted so + + + align:start position:0% +Row one are accepted so +ver ver accepts both of + + align:start position:0% +ver ver accepts both of + + + align:start position:0% +ver ver accepts both of +them now if there accepts both of them + + align:start position:0% +them now if there accepts both of them + + + align:start position:0% +them now if there accepts both of them +so we know that the leaves are different + + align:start position:0% +so we know that the leaves are different + + + align:start position:0% +so we know that the leaves are different +because in the leaves in one case I have + + align:start position:0% +because in the leaves in one case I have + + + align:start position:0% +because in the leaves in one case I have +here one and the other case I have zero + + align:start position:0% +here one and the other case I have zero + + + align:start position:0% +here one and the other case I have zero +so they have to be different so I know + + align:start position:0% +so they have to be different so I know + + + align:start position:0% +so they have to be different so I know +the leaves are different I also know + + align:start position:0% +the leaves are different I also know + + + align:start position:0% +the leaves are different I also know +that z0 + + align:start position:0% +that z0 + + + align:start position:0% +that z0 +D equals z1d these are both a + + align:start position:0% +D equals z1d these are both a + + + align:start position:0% +D equals z1d these are both a +root now of course I said we don't need + + align:start position:0% +root now of course I said we don't need + + + align:start position:0% +root now of course I said we don't need +to include it because but I'm just + + align:start position:0% +to include it because but I'm just + + + align:start position:0% +to include it because but I'm just +putting here because I want what the + + align:start position:0% +putting here because I want what the + + + align:start position:0% +putting here because I want what the +reason I want to include it is just for + + align:start position:0% +reason I want to include it is just for + + + align:start position:0% +reason I want to include it is just for +clarity to say look we have kind of D + + align:start position:0% +clarity to say look we have kind of D + + + align:start position:0% +clarity to say look we have kind of D +layers of information on each + + align:start position:0% +layers of information on each + + + align:start position:0% +layers of information on each +opening the leaves they must be + + align:start position:0% +opening the leaves they must be + + + align:start position:0% +opening the leaves they must be +different because one opens to zero one + + align:start position:0% +different because one opens to zero one + + + align:start position:0% +different because one opens to zero one +opens to one the root the last one must + + align:start position:0% +opens to one the root the last one must + + + align:start position:0% +opens to one the root the last one must +be the same it's the root + + align:start position:0% +be the same it's the root + + + align:start position:0% +be the same it's the root +it means that there must be some kind of + + align:start position:0% +it means that there must be some kind of + + + align:start position:0% +it means that there must be some kind of +two adjacent layers on which one of + + align:start position:0% +two adjacent layers on which one of + + + align:start position:0% +two adjacent layers on which one of +below they disagree and above they agree + + align:start position:0% +below they disagree and above they agree + + + align:start position:0% +below they disagree and above they agree +okay we know here they disagree here + + align:start position:0% +okay we know here they disagree here + + + align:start position:0% +okay we know here they disagree here +they agree okay they disagree do they + + align:start position:0% +they agree okay they disagree do they + + + align:start position:0% +they agree okay they disagree do they +disagree here disagree here at some + + align:start position:0% +disagree here disagree here at some + + + align:start position:0% +disagree here disagree here at some +point they're going to agree so we say + + align:start position:0% +point they're going to agree so we say + + + align:start position:0% +point they're going to agree so we say +there must + + align:start position:0% +there must + + + align:start position:0% +there must +be a layer J such that zj0 is different + + align:start position:0% +be a layer J such that zj0 is different + + + align:start position:0% +be a layer J such that zj0 is different +than zj1 but ZJ + one 0 is equal to + + align:start position:0% +than zj1 but ZJ + one 0 is equal to + + + align:start position:0% +than zj1 but ZJ + one 0 is equal to +ZJ + 1 + + align:start position:0% +ZJ + 1 + + + align:start position:0% +ZJ + 1 +1 yeah okay they disagree here how about + + align:start position:0% +1 yeah okay they disagree here how about + + + align:start position:0% +1 yeah okay they disagree here how about +one layer above do they agree if they + + align:start position:0% +one layer above do they agree if they + + + align:start position:0% +one layer above do they agree if they +agree great then that's going to be our + + align:start position:0% +agree great then that's going to be our + + + align:start position:0% +agree great then that's going to be our +J plus one they disagree let's go up + + align:start position:0% +J plus one they disagree let's go up + + + align:start position:0% +J plus one they disagree let's go up +until at some point they'll agree + + align:start position:0% +until at some point they'll agree + + + align:start position:0% +until at some point they'll agree +because they agree + + align:start position:0% + + + + align:start position:0% + +yeah oh thank you very much thank you uh + + align:start position:0% +yeah oh thank you very much thank you uh + + + align:start position:0% +yeah oh thank you very much thank you uh +great thank you yeah it's not just for + + align:start position:0% +great thank you yeah it's not just for + + + align:start position:0% +great thank you yeah it's not just for +the video it's also for you guys so I + + align:start position:0% +the video it's also for you guys so I + + + align:start position:0% +the video it's also for you guys so I +won't uh confuse you more than it thank + + align:start position:0% +won't uh confuse you more than it thank + + + align:start position:0% +won't uh confuse you more than it thank +you a one J One J + one thank + + align:start position:0% +you a one J One J + one thank + + + align:start position:0% +you a one J One J + one thank +you okay yes I I is + + align:start position:0% + + + + align:start position:0% + +it I did I miss + + align:start position:0% +it I did I miss + + + align:start position:0% +it I did I miss +I yes + + align:start position:0% +I yes + + + align:start position:0% +I yes +my God okay no there zero one + + align:start position:0% +my God okay no there zero one + + + align:start position:0% +my God okay no there zero one +ah okay did I get it right yes okay so + + align:start position:0% +ah okay did I get it right yes okay so + + + align:start position:0% +ah okay did I get it right yes okay so +there's a layer J said that in layer J + + align:start position:0% +there's a layer J said that in layer J + + + align:start position:0% +there's a layer J said that in layer J +they disagree in layer j+ one they + + align:start position:0% +they disagree in layer j+ one they + + + align:start position:0% +they disagree in layer j+ one they +agree that's it this is a collision why + + align:start position:0% +agree that's it this is a collision why + + + align:start position:0% +agree that's it this is a collision why +what is layer J + one one of them is the + + align:start position:0% +what is layer J + one one of them is the + + + align:start position:0% +what is layer J + one one of them is the +father is the + + align:start position:0% +father is the + + + align:start position:0% +father is the +parent so we have two that they + + align:start position:0% +parent so we have two that they + + + align:start position:0% +parent so we have two that they +disagree but both of these they agree + + align:start position:0% +disagree but both of these they agree + + + align:start position:0% +disagree but both of these they agree +on in particular they agree on this so + + align:start position:0% +on in particular they agree on this so + + + align:start position:0% +on in particular they agree on this so +done so we found a collision this must + + align:start position:0% +done so we found a collision this must + + + align:start position:0% +done so we found a collision this must +mean + + align:start position:0% + + + + align:start position:0% + +that the hash + + align:start position:0% +that the hash + + + align:start position:0% +that the hash +eval hash key of + + align:start position:0% +eval hash key of + + + align:start position:0% +eval hash key of +z0j is equal to + + align:start position:0% +z0j is equal to + + + align:start position:0% +z0j is equal to +eval H key of z1j because this value is + + align:start position:0% +eval H key of z1j because this value is + + + align:start position:0% +eval H key of z1j because this value is +one of the it's you know one of this and + + align:start position:0% +one of the it's you know one of this and + + + align:start position:0% +one of the it's you know one of this and +one one of this and one of this + + align:start position:0% +one one of this and one of this + + + align:start position:0% +one one of this and one of this +depending if it's the left or the right + + align:start position:0% +depending if it's the left or the right + + + align:start position:0% +depending if it's the left or the right +depending on the tree but and they're + + align:start position:0% +depending on the tree but and they're + + + align:start position:0% +depending on the tree but and they're +both equal so done I found a + + align:start position:0% + + + + align:start position:0% + +collision okay with the same exact + + align:start position:0% +collision okay with the same exact + + + align:start position:0% +collision okay with the same exact +probability so it's + + align:start position:0% +probability so it's + + + align:start position:0% +probability so it's +uh now as I said this I wrote here + + align:start position:0% +uh now as I said this I wrote here + + + align:start position:0% +uh now as I said this I wrote here +supposed to exist P Lambda I could have + + align:start position:0% +supposed to exist P Lambda I could have + + + align:start position:0% +supposed to exist P Lambda I could have +if we assumed that the underlying hash + + align:start position:0% +if we assumed that the underlying hash + + + align:start position:0% +if we assumed that the underlying hash +function is t- secure namely you can't + + align:start position:0% +function is t- secure namely you can't + + + align:start position:0% +function is t- secure namely you can't +find collisions even if you run time + + align:start position:0% +find collisions even if you run time + + + align:start position:0% +find collisions even if you run time +poly T of Lambda then we get that the + + align:start position:0% +poly T of Lambda then we get that the + + + align:start position:0% +poly T of Lambda then we get that the +Merle hash is POL secure because B all + + align:start position:0% +Merle hash is POL secure because B all + + + align:start position:0% +Merle hash is POL secure because B all +it does really is just run a it doesn't + + align:start position:0% +it does really is just run a it doesn't + + + align:start position:0% +it does really is just run a it doesn't +run much more than a it just runs a and + + align:start position:0% +run much more than a it just runs a and + + + align:start position:0% +run much more than a it just runs a and +then it does something very trivial so + + align:start position:0% +then it does something very trivial so + + + align:start position:0% +then it does something very trivial so +the complexity of breaking the miracle + + align:start position:0% +the complexity of breaking the miracle + + + align:start position:0% +the complexity of breaking the miracle +hash is really the same as the + + align:start position:0% +hash is really the same as the + + + align:start position:0% +hash is really the same as the +complexity of breaking the underlying + + align:start position:0% +complexity of breaking the underlying + + + align:start position:0% +complexity of breaking the underlying +hash so if the underlying hash is tsec + + align:start position:0% +hash so if the underlying hash is tsec + + + align:start position:0% +hash so if the underlying hash is tsec +Miracle hash is TC + + align:start position:0% + + + + align:start position:0% + +secure + + align:start position:0% + + + + align:start position:0% + +questions okay so where are we so we + + align:start position:0% +questions okay so where are we so we + + + align:start position:0% +questions okay so where are we so we +prove the Merkel hash as we saw the + + align:start position:0% +prove the Merkel hash as we saw the + + + align:start position:0% +prove the Merkel hash as we saw the +Merkel hash was used to give an + + align:start position:0% +Merkel hash was used to give an + + + align:start position:0% +Merkel hash was used to give an +interactive a succinct interactive + + align:start position:0% +interactive a succinct interactive + + + align:start position:0% +interactive a succinct interactive +argument for all of + + align:start position:0% +argument for all of + + + align:start position:0% +argument for all of +NP so now if you're willing to you know + + align:start position:0% +NP so now if you're willing to you know + + + align:start position:0% +NP so now if you're willing to you know +to you're happy with intrac + + align:start position:0% +to you're happy with intrac + + + align:start position:0% +to you're happy with intrac +protocols thank you very much I hope you + + align:start position:0% +protocols thank you very much I hope you + + + align:start position:0% +protocols thank you very much I hope you +enjoyed the semester and we're + + align:start position:0% +enjoyed the semester and we're + + + align:start position:0% +enjoyed the semester and we're +done if you're not though but as I said + + align:start position:0% +done if you're not though but as I said + + + align:start position:0% +done if you're not though but as I said +we're actually we're not happy with + + align:start position:0% +we're actually we're not happy with + + + align:start position:0% +we're actually we're not happy with +interactive protocols it's really + + align:start position:0% +interactive protocols it's really + + + align:start position:0% +interactive protocols it's really +interesting actually to think of the + + align:start position:0% +interesting actually to think of the + + + align:start position:0% +interesting actually to think of the +evolution of of this because you know it + + align:start position:0% +evolution of of this because you know it + + + align:start position:0% +evolution of of this because you know it +before all this interactive proofs and + + align:start position:0% +before all this interactive proofs and + + + align:start position:0% +before all this interactive proofs and +arguments and so on we had just + + align:start position:0% +arguments and so on we had just + + + align:start position:0% +arguments and so on we had just +mathematical proofs which were not + + align:start position:0% +mathematical proofs which were not + + + align:start position:0% +mathematical proofs which were not +interactive but they were very very + + align:start position:0% +interactive but they were very very + + + align:start position:0% +interactive but they were very very +long and people were not happy like kid + + align:start position:0% +long and people were not happy like kid + + + align:start position:0% +long and people were not happy like kid +like oh they're so long and then + + align:start position:0% +like oh they're so long and then + + + align:start position:0% +like oh they're so long and then +interactive proofs were defined I think + + align:start position:0% +interactive proofs were defined I think + + + align:start position:0% +interactive proofs were defined I think +they were defined only for the sake of + + align:start position:0% +they were defined only for the sake of + + + align:start position:0% +they were defined only for the sake of +zero knowledge they were defined just to + + align:start position:0% +zero knowledge they were defined just to + + + align:start position:0% +zero knowledge they were defined just to +get zero knowledge proofs I'm GNA + + align:start position:0% +get zero knowledge proofs I'm GNA + + + align:start position:0% +get zero knowledge proofs I'm GNA +actually mention we're going to talk + + align:start position:0% +actually mention we're going to talk + + + align:start position:0% +actually mention we're going to talk +about zero knowledge later + + align:start position:0% +about zero knowledge later + + + align:start position:0% +about zero knowledge later +today and this motivated kind of the int + + align:start position:0% +today and this motivated kind of the int + + + align:start position:0% +today and this motivated kind of the int +to introduce + + align:start position:0% +to introduce + + + align:start position:0% +to introduce +interraction and then people like wow + + align:start position:0% +interraction and then people like wow + + + align:start position:0% +interraction and then people like wow +you oh what a great forget about zero + + align:start position:0% +you oh what a great forget about zero + + + align:start position:0% +you oh what a great forget about zero +knowledge forget about cryptography this + + align:start position:0% +knowledge forget about cryptography this + + + align:start position:0% +knowledge forget about cryptography this +is such a great model using intraction + + align:start position:0% +is such a great model using intraction + + + align:start position:0% +is such a great model using intraction +we can prove a lot more right and we saw + + align:start position:0% +we can prove a lot more right and we saw + + + align:start position:0% +we can prove a lot more right and we saw +the Gare protocol you can can do like uh + + align:start position:0% +the Gare protocol you can can do like uh + + + align:start position:0% +the Gare protocol you can can do like uh +you can prove actually any any circuits + + align:start position:0% +you can prove actually any any circuits + + + align:start position:0% +you can prove actually any any circuits +that are really really huge as long as + + align:start position:0% +that are really really huge as long as + + + align:start position:0% +that are really really huge as long as +they're kind of have dep you can do PE + + align:start position:0% +they're kind of have dep you can do PE + + + align:start position:0% +they're kind of have dep you can do PE +space or any computation that has poly + + align:start position:0% +space or any computation that has poly + + + align:start position:0% +space or any computation that has poly +depth you verify can be any depth V you + + align:start position:0% +depth you verify can be any depth V you + + + align:start position:0% +depth you verify can be any depth V you +can the verify runs in time deep great + + align:start position:0% +can the verify runs in time deep great + + + align:start position:0% +can the verify runs in time deep great +not it doesn't run in the sign so it's + + align:start position:0% +not it doesn't run in the sign so it's + + + align:start position:0% +not it doesn't run in the sign so it's +much much more powerful wow wow wow and + + align:start position:0% +much much more powerful wow wow wow and + + + align:start position:0% +much much more powerful wow wow wow and +then people like actually with + + align:start position:0% +then people like actually with + + + align:start position:0% +then people like actually with +cryptographer can do much more great but + + align:start position:0% +cryptographer can do much more great but + + + align:start position:0% +cryptographer can do much more great but +now like but wait there was a big price + + align:start position:0% +now like but wait there was a big price + + + align:start position:0% +now like but wait there was a big price +we actually don't want ction so where + + align:start position:0% +we actually don't want ction so where + + + align:start position:0% +we actually don't want ction so where +are we are we back at + + align:start position:0% +are we are we back at + + + align:start position:0% +are we are we back at +NP NP is very we're back in the + + align:start position:0% +NP NP is very we're back in the + + + align:start position:0% +NP NP is very we're back in the +mathematical proof that are way way too + + align:start position:0% +mathematical proof that are way way too + + + align:start position:0% +mathematical proof that are way way too +long so I said + + align:start position:0% +long so I said + + + align:start position:0% +long so I said +no we're actually going to circle back + + align:start position:0% +no we're actually going to circle back + + + align:start position:0% +no we're actually going to circle back +in a very interesting way and get suin + + align:start position:0% +in a very interesting way and get suin + + + align:start position:0% +in a very interesting way and get suin +non-interactive + + align:start position:0% + + + + align:start position:0% + +proofs so how do we Circle back okay + + align:start position:0% + + + + align:start position:0% + +so so this idea of how to Circle back + + align:start position:0% +so so this idea of how to Circle back + + + align:start position:0% +so so this idea of how to Circle back +actually was + + align:start position:0% +actually was + + + align:start position:0% +actually was +um put forth by fat Cham this is in the + + align:start position:0% +um put forth by fat Cham this is in the + + + align:start position:0% +um put forth by fat Cham this is in the +mid 80s and + + align:start position:0% +mid 80s and + + + align:start position:0% +mid 80s and +86 they proposed a really really nice + + align:start position:0% +86 they proposed a really really nice + + + align:start position:0% +86 they proposed a really really nice +Paradigm actually they didn't think + + align:start position:0% +Paradigm actually they didn't think + + + align:start position:0% +Paradigm actually they didn't think +about this is this is 86 this is kind of + + align:start position:0% +about this is this is 86 this is kind of + + + align:start position:0% +about this is this is 86 this is kind of +before intractive proofs it was just + + align:start position:0% +before intractive proofs it was just + + + align:start position:0% +before intractive proofs it was just +when zonal was introduced um interactive + + align:start position:0% +when zonal was introduced um interactive + + + align:start position:0% +when zonal was introduced um interactive +proofs just came about but no you know + + align:start position:0% +proofs just came about but no you know + + + align:start position:0% +proofs just came about but no you know +there was no PCP no interactive argument + + align:start position:0% +there was no PCP no interactive argument + + + align:start position:0% +there was no PCP no interactive argument +none of that okay this is an 86 + + align:start position:0% + + + + align:start position:0% + +F they proposed the method + + align:start position:0% +F they proposed the method + + + align:start position:0% +F they proposed the method +of actually reducing interaction of + + align:start position:0% +of actually reducing interaction of + + + align:start position:0% +of actually reducing interaction of +constructing signature schemes now I I + + align:start position:0% +constructing signature schemes now I I + + + align:start position:0% +constructing signature schemes now I I +stand behind what I said that this class + + align:start position:0% +stand behind what I said that this class + + + align:start position:0% +stand behind what I said that this class +will not require a lot of cryptog crypto + + align:start position:0% +will not require a lot of cryptog crypto + + + align:start position:0% +will not require a lot of cryptog crypto +background you don't need to know what + + align:start position:0% +background you don't need to know what + + + align:start position:0% +background you don't need to know what +signature schemes are but the what they + + align:start position:0% +signature schemes are but the what they + + + align:start position:0% +signature schemes are but the what they +did their idea is there was there's a + + align:start position:0% +did their idea is there was there's a + + + align:start position:0% +did their idea is there was there's a +primitive called identification scheme I + + align:start position:0% +primitive called identification scheme I + + + align:start position:0% +primitive called identification scheme I +want to prove to you that I'm y okay how + + align:start position:0% +want to prove to you that I'm y okay how + + + align:start position:0% +want to prove to you that I'm y okay how +do I prove that I'm y I have a public + + align:start position:0% +do I prove that I'm y I have a public + + + align:start position:0% +do I prove that I'm y I have a public +key corresponding to my name and I'm + + align:start position:0% +key corresponding to my name and I'm + + + align:start position:0% +key corresponding to my name and I'm +going to prove to that I know the secret + + align:start position:0% +going to prove to that I know the secret + + + align:start position:0% +going to prove to that I know the secret +key + + align:start position:0% +key + + + align:start position:0% +key +me knowing whoever knows the secret key + + align:start position:0% +me knowing whoever knows the secret key + + + align:start position:0% +me knowing whoever knows the secret key +has my identity essentially that's how + + align:start position:0% +has my identity essentially that's how + + + align:start position:0% +has my identity essentially that's how +things work in the digital world so I'm + + align:start position:0% +things work in the digital world so I'm + + + align:start position:0% +things work in the digital world so I'm +going to prove to you that I know the + + align:start position:0% +going to prove to you that I know the + + + align:start position:0% +going to prove to you that I know the +secret key this proves that I'm me okay + + align:start position:0% +secret key this proves that I'm me okay + + + align:start position:0% +secret key this proves that I'm me okay +this proof was interactive okay + + align:start position:0% +this proof was interactive okay + + + align:start position:0% +this proof was interactive okay +identification Protocols are like three + + align:start position:0% +identification Protocols are like three + + + align:start position:0% +identification Protocols are like three +round protocols I give you a message + + align:start position:0% +round protocols I give you a message + + + align:start position:0% +round protocols I give you a message +Alpha you send me a question beta I give + + align:start position:0% +Alpha you send me a question beta I give + + + align:start position:0% +Alpha you send me a question beta I give +you an answer gamma you verify that's + + align:start position:0% +you an answer gamma you verify that's + + + align:start position:0% +you an answer gamma you verify that's +how it + + align:start position:0% +how it + + + align:start position:0% +how it +works now they said let's convert this + + align:start position:0% +works now they said let's convert this + + + align:start position:0% +works now they said let's convert this +identification scheme into a signature + + align:start position:0% +identification scheme into a signature + + + align:start position:0% +identification scheme into a signature +scheme instead of kind of interacting to + + align:start position:0% +scheme instead of kind of interacting to + + + align:start position:0% +scheme instead of kind of interacting to +make sure it's you every time you sign a + + align:start position:0% +make sure it's you every time you sign a + + + align:start position:0% +make sure it's you every time you sign a +you want to send a message kind of use + + align:start position:0% +you want to send a message kind of use + + + align:start position:0% +you want to send a message kind of use +this use this message take this + + align:start position:0% +this use this message take this + + + align:start position:0% +this use this message take this +identification protocol together with + + align:start position:0% +identification protocol together with + + + align:start position:0% +identification protocol together with +some message and kind of eliminate the + + align:start position:0% +some message and kind of eliminate the + + + align:start position:0% +some message and kind of eliminate the +interaction I'll explain exactly how + + align:start position:0% +interaction I'll explain exactly how + + + align:start position:0% +interaction I'll explain exactly how +they do it but but they do it in a way + + align:start position:0% +they do it but but they do it in a way + + + align:start position:0% +they do it but but they do it in a way +to construct signature scheme that was + + align:start position:0% +to construct signature scheme that was + + + align:start position:0% +to construct signature scheme that was +their + + align:start position:0% +their + + + align:start position:0% +their +goal but now after several years after + + align:start position:0% +goal but now after several years after + + + align:start position:0% +goal but now after several years after +we use it all the time to actually + + align:start position:0% +we use it all the time to actually + + + align:start position:0% +we use it all the time to actually +forget about just the specific + + align:start position:0% +forget about just the specific + + + align:start position:0% +forget about just the specific +application of identification skin to + + align:start position:0% +application of identification skin to + + + align:start position:0% +application of identification skin to +signature that's one application + + align:start position:0% +signature that's one application + + + align:start position:0% +signature that's one application +but actually we can show we can use it + + align:start position:0% +but actually we can show we can use it + + + align:start position:0% +but actually we can show we can use it +to reduce to eliminate intraction not + + align:start position:0% +to reduce to eliminate intraction not + + + align:start position:0% +to reduce to eliminate intraction not +only from identification scheme but from + + align:start position:0% +only from identification scheme but from + + + align:start position:0% +only from identification scheme but from +any interactive protocol that is public + + align:start position:0% +any interactive protocol that is public + + + align:start position:0% +any interactive protocol that is public +coin so let me explain so now take any + + align:start position:0% +coin so let me explain so now take any + + + align:start position:0% +coin so let me explain so now take any +protocol uh so so this is a this is a + + align:start position:0% + + + + align:start position:0% + +paradigm for eliminating + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +interaction + + align:start position:0% +interaction + + + align:start position:0% +interaction +from + + align:start position:0% +from + + + align:start position:0% +from +interactive + + align:start position:0% + + + + align:start position:0% + +protocols that are public + + align:start position:0% +protocols that are public + + + align:start position:0% +protocols that are public +coin so not all protocol but ones that + + align:start position:0% +coin so not all protocol but ones that + + + align:start position:0% +coin so not all protocol but ones that +are public coin so what is a public coin + + align:start position:0% +are public coin so what is a public coin + + + align:start position:0% +are public coin so what is a public coin +protocol take any protocol let say a + + align:start position:0% +protocol take any protocol let say a + + + align:start position:0% +protocol take any protocol let say a +proof so I have aover and a VAR + + align:start position:0% +proof so I have aover and a VAR + + + align:start position:0% +proof so I have aover and a VAR +verifier and suppose for a second it's + + align:start position:0% +verifier and suppose for a second it's + + + align:start position:0% +verifier and suppose for a second it's +so the suppose for Simplicity that it's + + align:start position:0% +so the suppose for Simplicity that it's + + + align:start position:0% +so the suppose for Simplicity that it's +three messages okay so the verify the + + align:start position:0% +three messages okay so the verify the + + + align:start position:0% +three messages okay so the verify the +prover sends a message Alpha the + + align:start position:0% +prover sends a message Alpha the + + + align:start position:0% +prover sends a message Alpha the +verifier sends beta which is random okay + + align:start position:0% +verifier sends beta which is random okay + + + align:start position:0% +verifier sends beta which is random okay +that's public CO mean the message of the + + align:start position:0% +that's public CO mean the message of the + + + align:start position:0% +that's public CO mean the message of the +ver far is completely random okay let's + + align:start position:0% +ver far is completely random okay let's + + + align:start position:0% +ver far is completely random okay let's +say it's kind of Lambda bits if it's + + align:start position:0% +say it's kind of Lambda bits if it's + + + align:start position:0% +say it's kind of Lambda bits if it's +less then just P it to be Lambda okay + + align:start position:0% +less then just P it to be Lambda okay + + + align:start position:0% +less then just P it to be Lambda okay +and if it's more just call that Lambda + + align:start position:0% +and if it's more just call that Lambda + + + align:start position:0% +and if it's more just call that Lambda +make that the security parameter just + + align:start position:0% +make that the security parameter just + + + align:start position:0% +make that the security parameter just +increase the security parameter + + align:start position:0% +increase the security parameter + + + align:start position:0% +increase the security parameter +okay now you send + + align:start position:0% +okay now you send + + + align:start position:0% +okay now you send +gamma and maybe it's more round so maybe + + align:start position:0% +gamma and maybe it's more round so maybe + + + align:start position:0% +gamma and maybe it's more round so maybe +then he sends + + align:start position:0% +then he sends + + + align:start position:0% +then he sends +Delta let's say random bits and then you + + align:start position:0% +Delta let's say random bits and then you + + + align:start position:0% +Delta let's say random bits and then you +say epsilon and you can continue okay + + align:start position:0% +say epsilon and you can continue okay + + + align:start position:0% +say epsilon and you can continue okay +let me stop here for the sake + + align:start position:0% +let me stop here for the sake + + + align:start position:0% +let me stop here for the sake +of okay now I'm going to eliminate + + align:start position:0% +of okay now I'm going to eliminate + + + align:start position:0% +of okay now I'm going to eliminate +intraction how do we eliminate + + align:start position:0% +intraction how do we eliminate + + + align:start position:0% +intraction how do we eliminate +intraction it seem like intraction is + + align:start position:0% +intraction it seem like intraction is + + + align:start position:0% +intraction it seem like intraction is +very important I mean the entire kind of + + align:start position:0% +very important I mean the entire kind of + + + align:start position:0% +very important I mean the entire kind of +if you remember the surack and G + + align:start position:0% +if you remember the surack and G + + + align:start position:0% +if you remember the surack and G +I mean it's tempting maybe to say oh + + align:start position:0% +I mean it's tempting maybe to say oh + + + align:start position:0% +I mean it's tempting maybe to say oh +tell the prover compute Alpha Beta GMA + + align:start position:0% +tell the prover compute Alpha Beta GMA + + + align:start position:0% +tell the prover compute Alpha Beta GMA +just compute the transcript on your own + + align:start position:0% +just compute the transcript on your own + + + align:start position:0% +just compute the transcript on your own +you simulate the verifi messages then + + align:start position:0% +you simulate the verifi messages then + + + align:start position:0% +you simulate the verifi messages then +he'll + + align:start position:0% +he'll + + + align:start position:0% +he'll +cheat so how do you get rid of the + + align:start position:0% +cheat so how do you get rid of the + + + align:start position:0% +cheat so how do you get rid of the +interaction seems + + align:start position:0% +interaction seems + + + align:start position:0% +interaction seems +really really hard actually it's so easy + + align:start position:0% +really really hard actually it's so easy + + + align:start position:0% +really really hard actually it's so easy +I mean there idea is Trivial so what is + + align:start position:0% +I mean there idea is Trivial so what is + + + align:start position:0% +I mean there idea is Trivial so what is +their idea they said they say the + + align:start position:0% +their idea they said they say the + + + align:start position:0% +their idea they said they say the +following + + align:start position:0% +following + + + align:start position:0% +following +how does the verifier how does the Prov + + align:start position:0% +how does the verifier how does the Prov + + + align:start position:0% +how does the verifier how does the Prov +get this + + align:start position:0% +get this + + + align:start position:0% +get this +beta the verifier chose it so you know + + align:start position:0% +beta the verifier chose it so you know + + + align:start position:0% +beta the verifier chose it so you know +what let's comp let not have the ver now + + align:start position:0% +what let's comp let not have the ver now + + + align:start position:0% +what let's comp let not have the ver now +we don't have a verifier it's not + + align:start position:0% +we don't have a verifier it's not + + + align:start position:0% +we don't have a verifier it's not +interactive there's no verifier so how + + align:start position:0% +interactive there's no verifier so how + + + align:start position:0% +interactive there's no verifier so how +to compute this beta let's compute it as + + align:start position:0% +to compute this beta let's compute it as + + + align:start position:0% +to compute this beta let's compute it as +kind of a hash function applied to the + + align:start position:0% +kind of a hash function applied to the + + + align:start position:0% +kind of a hash function applied to the +transcript so + + align:start position:0% +transcript so + + + align:start position:0% +transcript so +far so let me explain so + + align:start position:0% +far so let me explain so + + + align:start position:0% +far so let me explain so +how here's how you convert it + + align:start position:0% +how here's how you convert it + + + align:start position:0% +how here's how you convert it +to p f CH + + align:start position:0% +to p f CH + + + align:start position:0% +to p f CH +V this is associated with some hash + + align:start position:0% +V this is associated with some hash + + + align:start position:0% +V this is associated with some hash +family okay there's some It's associated + + align:start position:0% +family okay there's some It's associated + + + align:start position:0% +family okay there's some It's associated +with a hash family so the F Paradigm you + + align:start position:0% +with a hash family so the F Paradigm you + + + align:start position:0% +with a hash family so the F Paradigm you +can take any hash family and use that to + + align:start position:0% +can take any hash family and use that to + + + align:start position:0% +can take any hash family and use that to +reduce interraction how do you use it to + + align:start position:0% +reduce interraction how do you use it to + + + align:start position:0% +reduce interraction how do you use it to +reduce intraction now there's some hash + + align:start position:0% +reduce intraction now there's some hash + + + align:start position:0% +reduce intraction now there's some hash +key that's chosen once and for all + + align:start position:0% +key that's chosen once and for all + + + align:start position:0% +key that's chosen once and for all +everybody knows it either the verifier + + align:start position:0% +everybody knows it either the verifier + + + align:start position:0% +everybody knows it either the verifier +sends it once or if you think about + + align:start position:0% +sends it once or if you think about + + + align:start position:0% +sends it once or if you think about +public like everybody can verify I don't + + align:start position:0% +public like everybody can verify I don't + + + align:start position:0% +public like everybody can verify I don't +know the + + align:start position:0% +know the + + + align:start position:0% +know the +the US government publishes this hash + + align:start position:0% +the US government publishes this hash + + + align:start position:0% +the US government publishes this hash +key everybody uses this hash key okay + + align:start position:0% +key everybody uses this hash key okay + + + align:start position:0% +key everybody uses this hash key okay +there's some fixed hash key everybody + + align:start position:0% +there's some fixed hash key everybody + + + align:start position:0% +there's some fixed hash key everybody +uses it now once we agree on a hash key + + align:start position:0% +uses it now once we agree on a hash key + + + align:start position:0% +uses it now once we agree on a hash key +what does the prover + + align:start position:0% +what does the prover + + + align:start position:0% +what does the prover +do he computes Alpha that's let's say he + + align:start position:0% +do he computes Alpha that's let's say he + + + align:start position:0% +do he computes Alpha that's let's say he +wants to prove that X is in some + + align:start position:0% + + + + align:start position:0% + +language so he let's say he want he's + + align:start position:0% +language so he let's say he want he's + + + align:start position:0% +language so he let's say he want he's +telling okay I'm going to prove to you + + align:start position:0% +telling okay I'm going to prove to you + + + align:start position:0% +telling okay I'm going to prove to you +that X is in the language let me prove + + align:start position:0% +that X is in the language let me prove + + + align:start position:0% +that X is in the language let me prove +it to you okay I compute the + + align:start position:0% +it to you okay I compute the + + + align:start position:0% +it to you okay I compute the +alpha now I'm waiting for a beta but + + align:start position:0% +alpha now I'm waiting for a beta but + + + align:start position:0% +alpha now I'm waiting for a beta but +there's no verifier fine the I'll tell + + align:start position:0% +there's no verifier fine the I'll tell + + + align:start position:0% +there's no verifier fine the I'll tell +you what the beta is beta is just has is + + align:start position:0% +you what the beta is beta is just has is + + + align:start position:0% +you what the beta is beta is just has is +going to be EV Val of hash key on the + + align:start position:0% +going to be EV Val of hash key on the + + + align:start position:0% +going to be EV Val of hash key on the +transcript so far X in Alpha that's + + align:start position:0% +transcript so far X in Alpha that's + + + align:start position:0% +transcript so far X in Alpha that's +currently what's in the transcript the + + align:start position:0% +currently what's in the transcript the + + + align:start position:0% +currently what's in the transcript the +the statement and the first message + + align:start position:0% +the statement and the first message + + + align:start position:0% +the statement and the first message +Alpha now the proof is like okay this is + + align:start position:0% +Alpha now the proof is like okay this is + + + align:start position:0% +Alpha now the proof is like okay this is +the beta I got from the verifier he's + + align:start position:0% +the beta I got from the verifier he's + + + align:start position:0% +the beta I got from the verifier he's +interpreting this as the beta he got + + align:start position:0% +interpreting this as the beta he got + + + align:start position:0% +interpreting this as the beta he got +from the verifier and now he computes + + align:start position:0% +from the verifier and now he computes + + + align:start position:0% +from the verifier and now he computes +gamma my answer + + align:start position:0% +gamma my answer + + + align:start position:0% +gamma my answer +the Pro's answer now he's waiting for a + + align:start position:0% +the Pro's answer now he's waiting for a + + + align:start position:0% +the Pro's answer now he's waiting for a +message a query from the verifier some + + align:start position:0% +message a query from the verifier some + + + align:start position:0% +message a query from the verifier some +Delta but there is no verifier so he's + + align:start position:0% +Delta but there is no verifier so he's + + + align:start position:0% +Delta but there is no verifier so he's +going to compute + + align:start position:0% +going to compute + + + align:start position:0% +going to compute +Delta as eval of the hash key using the + + align:start position:0% +Delta as eval of the hash key using the + + + align:start position:0% +Delta as eval of the hash key using the +transcript so far so X Alpha Beta + + align:start position:0% +transcript so far so X Alpha Beta + + + align:start position:0% +transcript so far so X Alpha Beta +gamma once he has Delta he's going to go + + align:start position:0% +gamma once he has Delta he's going to go + + + align:start position:0% +gamma once he has Delta he's going to go +back to being aover and + + align:start position:0% +back to being aover and + + + align:start position:0% +back to being aover and +compute Epsilon + + align:start position:0% +compute Epsilon + + + align:start position:0% +compute Epsilon +and then you can continue next message + + align:start position:0% +and then you can continue next message + + + align:start position:0% +and then you can continue next message +he goes computes a hash value of all the + + align:start position:0% +he goes computes a hash value of all the + + + align:start position:0% +he goes computes a hash value of all the +transends of so far compute the next + + align:start position:0% +transends of so far compute the next + + + align:start position:0% +transends of so far compute the next +Pro's + + align:start position:0% +Pro's + + + align:start position:0% +Pro's +message another ver and we go that's how + + align:start position:0% +message another ver and we go that's how + + + align:start position:0% +message another ver and we go that's how +we + + align:start position:0% +we + + + align:start position:0% +we +continue any questions about so what + + align:start position:0% +continue any questions about so what + + + align:start position:0% +continue any questions about so what +what did we go we got we started from an + + align:start position:0% +what did we go we got we started from an + + + align:start position:0% +what did we go we got we started from an +interactive + + align:start position:0% +interactive + + + align:start position:0% +interactive +protocol can have many rounds and now + + align:start position:0% +protocol can have many rounds and now + + + align:start position:0% +protocol can have many rounds and now +all we need is to agree on a + + align:start position:0% +all we need is to agree on a + + + align:start position:0% +all we need is to agree on a +haski and once we agree on Hashi the pro + + align:start position:0% +haski and once we agree on Hashi the pro + + + align:start position:0% +haski and once we agree on Hashi the pro +just gives you this is one message + + align:start position:0% +just gives you this is one message + + + align:start position:0% +just gives you this is one message +that's + + align:start position:0% +that's + + + align:start position:0% +that's +it + + align:start position:0% + + + + align:start position:0% + +yeah good great question is it important + + align:start position:0% +yeah good great question is it important + + + align:start position:0% +yeah good great question is it important +to include beta actually you don't need + + align:start position:0% +to include beta actually you don't need + + + align:start position:0% +to include beta actually you don't need +to include beta at all because the + + align:start position:0% +to include beta at all because the + + + align:start position:0% +to include beta at all because the +verifier can compute beta so we you only + + align:start position:0% +verifier can compute beta so we you only + + + align:start position:0% +verifier can compute beta so we you only +need to know beta so you can compute + + align:start position:0% +need to know beta so you can compute + + + align:start position:0% +need to know beta so you can compute +gamma you actually don't need to include + + align:start position:0% +gamma you actually don't need to include + + + align:start position:0% +gamma you actually don't need to include +it great question great great + + align:start position:0% + + + + align:start position:0% + +question so note for example if you + + align:start position:0% +question so note for example if you + + + align:start position:0% +question so note for example if you +think about kilan mikali protocol you + + align:start position:0% +think about kilan mikali protocol you + + + align:start position:0% +think about kilan mikali protocol you +may not remembered but let me just write + + align:start position:0% +may not remembered but let me just write + + + align:start position:0% +may not remembered but let me just write +it here just to refresh your memory why + + align:start position:0% +it here just to refresh your memory why + + + align:start position:0% +it here just to refresh your memory why +not you don't need to actually to + + align:start position:0% +not you don't need to actually to + + + align:start position:0% +not you don't need to actually to +understand this but uh since it's such a + + align:start position:0% +understand this but uh since it's such a + + + align:start position:0% +understand this but uh since it's such a +nice protocol and so how does it go + + align:start position:0% +nice protocol and so how does it go + + + align:start position:0% +nice protocol and so how does it go +there's a prover and a verifier the + + align:start position:0% +there's a prover and a verifier the + + + align:start position:0% +there's a prover and a verifier the +verifier sends a hash key so he wants to + + align:start position:0% +verifier sends a hash key so he wants to + + + align:start position:0% +verifier sends a hash key so he wants to +prove that X is an + + align:start position:0% +prove that X is an + + + align:start position:0% +prove that X is an +L he does a Merkle + + align:start position:0% +L he does a Merkle + + + align:start position:0% +L he does a Merkle +hash of the PCP so he computes a PCP Pi + + align:start position:0% +hash of the PCP so he computes a PCP Pi + + + align:start position:0% +hash of the PCP so he computes a PCP Pi +is a + + align:start position:0% +is a + + + align:start position:0% +is a +PCP for x and + + align:start position:0% +PCP for x and + + + align:start position:0% +PCP for x and +L and he sends you the Merkel hash so he + + align:start position:0% +L and he sends you the Merkel hash so he + + + align:start position:0% +L and he sends you the Merkel hash so he +sends you root + + align:start position:0% + + + + align:start position:0% + +and the and the depth + + align:start position:0% +and the and the depth + + + align:start position:0% +and the and the depth +that's that's just the so he takes the + + align:start position:0% +that's that's just the so he takes the + + + align:start position:0% +that's that's just the so he takes the +PCP and he does a hatch with local + + align:start position:0% +PCP and he does a hatch with local + + + align:start position:0% +PCP and he does a hatch with local +opening for example mer hatch actually + + align:start position:0% +opening for example mer hatch actually + + + align:start position:0% +opening for example mer hatch actually +can do any hatch with local opening that + + align:start position:0% +can do any hatch with local opening that + + + align:start position:0% +can do any hatch with local opening that +you want this is the most common one and + + align:start position:0% +you want this is the most common one and + + + align:start position:0% +you want this is the most common one and +then he gets kind of the randomness from + + align:start position:0% +then he gets kind of the randomness from + + + align:start position:0% +then he gets kind of the randomness from +the PCP verifier so this is R from our + + align:start position:0% +the PCP verifier so this is R from our + + + align:start position:0% +the PCP verifier so this is R from our +correspond to the PCP + + align:start position:0% +correspond to the PCP + + + align:start position:0% +correspond to the PCP +verifier this determines a few locations + + align:start position:0% +verifier this determines a few locations + + + align:start position:0% +verifier this determines a few locations +to open so now he opens so he gives so + + align:start position:0% +to open so now he opens so he gives so + + + align:start position:0% +to open so now he opens so he gives so +this may this you know this Randomness + + align:start position:0% +this may this you know this Randomness + + + align:start position:0% +this may this you know this Randomness +corresponds to like some locations i1 up + + align:start position:0% +corresponds to like some locations i1 up + + + align:start position:0% +corresponds to like some locations i1 up +to I L and then you just Open PI i1 with + + align:start position:0% +to I L and then you just Open PI i1 with + + + align:start position:0% +to I L and then you just Open PI i1 with +open one up to Pi i l with open + + align:start position:0% +open one up to Pi i l with open + + + align:start position:0% +open one up to Pi i l with open +L that's the protocol note this is + + align:start position:0% +L that's the protocol note this is + + + align:start position:0% +L that's the protocol note this is +completely + + align:start position:0% +completely + + + align:start position:0% +completely +random it's the randomness of the PCP + + align:start position:0% +random it's the randomness of the PCP + + + align:start position:0% +random it's the randomness of the PCP +verifier so we can uh eliminate + + align:start position:0% +verifier so we can uh eliminate + + + align:start position:0% +verifier so we can uh eliminate +intraction this you if you think of it + + align:start position:0% +intraction this you if you think of it + + + align:start position:0% +intraction this you if you think of it +this is just kind of a protocol where + + align:start position:0% +this is just kind of a protocol where + + + align:start position:0% +this is just kind of a protocol where +you send a hash key and then you have + + align:start position:0% +you send a hash key and then you have + + + align:start position:0% +you send a hash key and then you have +kind of Alpha Beta + + align:start position:0% + + + + align:start position:0% + +gamma okay so let's eliminate + + align:start position:0% +gamma okay so let's eliminate + + + align:start position:0% +gamma okay so let's eliminate +interaction so how do we eliminate + + align:start position:0% +interaction so how do we eliminate + + + align:start position:0% +interaction so how do we eliminate +interaction well there's this hash key + + align:start position:0% +interaction well there's this hash key + + + align:start position:0% +interaction well there's this hash key +let's we can use this hash key to do but + + align:start position:0% +let's we can use this hash key to do but + + + align:start position:0% +let's we can use this hash key to do but +we can also use another hash key hash + + align:start position:0% +we can also use another hash key hash + + + align:start position:0% +we can also use another hash key hash +key and + + align:start position:0% +key and + + + align:start position:0% +key and +now the well this can be now you give + + align:start position:0% +now the well this can be now you give + + + align:start position:0% +now the well this can be now you give +Alpha beta is going to be simply you + + align:start position:0% +Alpha beta is going to be simply you + + + align:start position:0% +Alpha beta is going to be simply you +don't have to include it but it's going + + align:start position:0% +don't have to include it but it's going + + + align:start position:0% +don't have to include it but it's going +to be in your in our head it's going to + + align:start position:0% +to be in your in our head it's going to + + + align:start position:0% +to be in your in our head it's going to +be eval of hash + + align:start position:0% + + + + align:start position:0% + +hash of X in + + align:start position:0% +hash of X in + + + align:start position:0% +hash of X in +Alpha and then maybe hash key is also + + align:start position:0% +Alpha and then maybe hash key is also + + + align:start position:0% +Alpha and then maybe hash key is also +part of the + + align:start position:0% +part of the + + + align:start position:0% +part of the +transcript and and uh this gives bit and + + align:start position:0% +transcript and and uh this gives bit and + + + align:start position:0% +transcript and and uh this gives bit and +now you compute the GMA which is the + + align:start position:0% + + + + align:start position:0% + +opening okay so you can + + align:start position:0% +opening okay so you can + + + align:start position:0% +opening okay so you can +you can take any so now if what does the + + align:start position:0% +you can take any so now if what does the + + + align:start position:0% +you can take any so now if what does the +F give you it gives us a away remember K + + align:start position:0% +F give you it gives us a away remember K + + + align:start position:0% +F give you it gives us a away remember K +mikali was very succinct right you can + + align:start position:0% +mikali was very succinct right you can + + + align:start position:0% +mikali was very succinct right you can +take X any let's say NP + + align:start position:0% +take X any let's say NP + + + align:start position:0% +take X any let's say NP +language n can be very large it can be + + align:start position:0% +language n can be very large it can be + + + align:start position:0% +language n can be very large it can be +Lambda to that thousand I know it can be + + align:start position:0% +Lambda to that thousand I know it can be + + + align:start position:0% +Lambda to that thousand I know it can be +what it can be even super poom Lambda it + + align:start position:0% +what it can be even super poom Lambda it + + + align:start position:0% +what it can be even super poom Lambda it +can be almost as l two to the + + align:start position:0% +can be almost as l two to the + + + align:start position:0% +can be almost as l two to the +Lambda + + align:start position:0% +Lambda + + + align:start position:0% +Lambda +okay and look how sucing the protocol is + + align:start position:0% +okay and look how sucing the protocol is + + + align:start position:0% +okay and look how sucing the protocol is +you just send a hash key the root which + + align:start position:0% +you just send a hash key the root which + + + align:start position:0% +you just send a hash key the root which +is Lambda bits and the opening and this + + align:start position:0% +is Lambda bits and the opening and this + + + align:start position:0% +is Lambda bits and the opening and this +the PCP is all L the bits poly L the + + align:start position:0% +the PCP is all L the bits poly L the + + + align:start position:0% +the PCP is all L the bits poly L the +bits so very very succinct and now you + + align:start position:0% +bits so very very succinct and now you + + + align:start position:0% +bits so very very succinct and now you +can even just make it + + align:start position:0% +can even just make it + + + align:start position:0% +can even just make it +so what is this you can all send it all + + align:start position:0% +so what is this you can all send it all + + + align:start position:0% +so what is this you can all send it all +in one round so what what does it give + + align:start position:0% +in one round so what what does it give + + + align:start position:0% +in one round so what what does it give +you what does it tell us that you we can + + align:start position:0% +you what does it tell us that you we can + + + align:start position:0% +you what does it tell us that you we can +take any NP + + align:start position:0% +take any NP + + + align:start position:0% +take any NP +statement and give a proof of size poly + + align:start position:0% +statement and give a proof of size poly + + + align:start position:0% +statement and give a proof of size poly +Lambda doesn't matter what size X + + align:start position:0% + + + + align:start position:0% + +is that's + + align:start position:0% +is that's + + + align:start position:0% +is that's +amazing without cryptography we need po + + align:start position:0% +amazing without cryptography we need po + + + align:start position:0% +amazing without cryptography we need po +you know these G Witnesses + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +prob imagine ofd hash family where there + + align:start position:0% +prob imagine ofd hash family where there + + + align:start position:0% +prob imagine ofd hash family where there +exist hash keys that are really bad okay + + align:start position:0% +exist hash keys that are really bad okay + + + align:start position:0% +exist hash keys that are really bad okay +and so I guess here it's fine because + + align:start position:0% +and so I guess here it's fine because + + + align:start position:0% +and so I guess here it's fine because +the verifier chooses the hash key but + + align:start position:0% +the verifier chooses the hash key but + + + align:start position:0% +the verifier chooses the hash key but +you might imagine if the US publishes a + + align:start position:0% +you might imagine if the US publishes a + + + align:start position:0% +you might imagine if the US publishes a +anything else what if it happens to be a + + align:start position:0% +anything else what if it happens to be a + + + align:start position:0% +anything else what if it happens to be a +bad one or to be a bad one okay you two + + align:start position:0% +bad one or to be a bad one okay you two + + + align:start position:0% +bad one or to be a bad one okay you two +things first you're saying who chooses + + align:start position:0% +things first you're saying who chooses + + + align:start position:0% +things first you're saying who chooses +this hash key of the F how do we know + + align:start position:0% +this hash key of the F how do we know + + + align:start position:0% +this hash key of the F how do we know +that we trusted but you know it's much + + align:start position:0% +that we trusted but you know it's much + + + align:start position:0% +that we trusted but you know it's much +worse than that is it secure let's say + + align:start position:0% +worse than that is it secure let's say + + + align:start position:0% +worse than that is it secure let's say +let's say it's chosen randomly from the + + align:start position:0% +let's say it's chosen randomly from the + + + align:start position:0% +let's say it's chosen randomly from the +hash + + align:start position:0% +hash + + + align:start position:0% +hash +family is this + + align:start position:0% +family is this + + + align:start position:0% +family is this +sound it's so again what did we do here + + align:start position:0% +sound it's so again what did we do here + + + align:start position:0% +sound it's so again what did we do here +we started with an interactive protocol + + align:start position:0% +we started with an interactive protocol + + + align:start position:0% +we started with an interactive protocol +we proved it sound let's say k m sound + + align:start position:0% +we proved it sound let's say k m sound + + + align:start position:0% +we proved it sound let's say k m sound +we proved it ass we have Collision in + + align:start position:0% +we proved it ass we have Collision in + + + align:start position:0% +we proved it ass we have Collision in +hash we prove that it + + align:start position:0% +hash we prove that it + + + align:start position:0% +hash we prove that it +sound it sound assuming the prover gets + + align:start position:0% +sound it sound assuming the prover gets + + + align:start position:0% +sound it sound assuming the prover gets +the ver the messages of the verify + + align:start position:0% +the ver the messages of the verify + + + align:start position:0% +the ver the messages of the verify +randomly that's one 20 it sounds that's + + align:start position:0% +randomly that's one 20 it sounds that's + + + align:start position:0% +randomly that's one 20 it sounds that's +we used it to Pro Sound is + + align:start position:0% +we used it to Pro Sound is + + + align:start position:0% +we used it to Pro Sound is +now what am I saying what are we doing + + align:start position:0% +now what am I saying what are we doing + + + align:start position:0% +now what am I saying what are we doing +now I'm saying oh forget about it it's + + align:start position:0% +now I'm saying oh forget about it it's + + + align:start position:0% +now I'm saying oh forget about it it's +not random actually you comput it on + + align:start position:0% +not random actually you comput it on + + + align:start position:0% +not random actually you comput it on +your + + align:start position:0% +your + + + align:start position:0% +your +own from some hash key that someone + + align:start position:0% +own from some hash key that someone + + + align:start position:0% +own from some hash key that someone +chooses even honestly from let's say we + + align:start position:0% +chooses even honestly from let's say we + + + align:start position:0% +chooses even honestly from let's say we +agree we all agreed on some hash family + + align:start position:0% +agree we all agreed on some hash family + + + align:start position:0% +agree we all agreed on some hash family +and someone honestly chose a hash key + + align:start position:0% +and someone honestly chose a hash key + + + align:start position:0% +and someone honestly chose a hash key +but now you know this hash key now you + + align:start position:0% +but now you know this hash key now you + + + align:start position:0% +but now you know this hash key now you +compute who says it sound I mean is it + + align:start position:0% +compute who says it sound I mean is it + + + align:start position:0% +compute who says it sound I mean is it +still sound maybe it's not + + align:start position:0% + + + + align:start position:0% + +sound okay so + + align:start position:0% +sound okay so + + + align:start position:0% +sound okay so +first of all okay so first of all of + + align:start position:0% +first of all okay so first of all of + + + align:start position:0% +first of all okay so first of all of +course there's one can think + + align:start position:0% +course there's one can think + + + align:start position:0% +course there's one can think +of this hash this hash functions need to + + align:start position:0% +of this hash this hash functions need to + + + align:start position:0% +of this hash this hash functions need to +have some property okay Collision + + align:start position:0% +have some property okay Collision + + + align:start position:0% +have some property okay Collision +resistance like at the minimum if if you + + align:start position:0% +resistance like at the minimum if if you + + + align:start position:0% +resistance like at the minimum if if you +can find collisions for example here + + align:start position:0% +can find collisions for example here + + + align:start position:0% +can find collisions for example here +you're screwed it can be it can be ID it + + align:start position:0% +you're screwed it can be it can be ID it + + + align:start position:0% +you're screwed it can be it can be ID it +can be trivial okay so you need some + + align:start position:0% +can be trivial okay so you need some + + + align:start position:0% +can be trivial okay so you need some +property now the question is what + + align:start position:0% +property now the question is what + + + align:start position:0% +property now the question is what +property do you need what property do + + align:start position:0% +property do you need what property do + + + align:start position:0% +property do you need what property do +you need from this hash family to argue + + align:start position:0% +you need from this hash family to argue + + + align:start position:0% +you need from this hash family to argue +soundness yeah + + align:start position:0% + + + + align:start position:0% + +very very okay good so it seems like + + align:start position:0% +very very okay good so it seems like + + + align:start position:0% +very very okay good so it seems like +well what do you need it need to be + + align:start position:0% +well what do you need it need to be + + + align:start position:0% +well what do you need it need to be +random like in the protocol like okay we + + align:start position:0% +random like in the protocol like okay we + + + align:start position:0% +random like in the protocol like okay we +we want to say take any what is our goal + + align:start position:0% +we want to say take any what is our goal + + + align:start position:0% +we want to say take any what is our goal +our goal is to say take any + + align:start position:0% +our goal is to say take any + + + align:start position:0% +our goal is to say take any +protocol that is sound public coin and + + align:start position:0% +protocol that is sound public coin and + + + align:start position:0% +protocol that is sound public coin and +we want to convert it to non-interactive + + align:start position:0% +we want to convert it to non-interactive + + + align:start position:0% +we want to convert it to non-interactive +that's what we're trying to do now I'm + + align:start position:0% +that's what we're trying to do now I'm + + + align:start position:0% +that's what we're trying to do now I'm +saying what property do you need well + + align:start position:0% +saying what property do you need well + + + align:start position:0% +saying what property do you need well +look here the our guarantee was that it + + align:start position:0% +look here the our guarantee was that it + + + align:start position:0% +look here the our guarantee was that it +sound if this was random so need this + + align:start position:0% +sound if this was random so need this + + + align:start position:0% +sound if this was random so need this +has to be somehow + + align:start position:0% +has to be somehow + + + align:start position:0% +has to be somehow +random stand for reason so this is okay + + align:start position:0% +random stand for reason so this is okay + + + align:start position:0% +random stand for reason so this is okay +but look hash functions are not random + + align:start position:0% +but look hash functions are not random + + + align:start position:0% +but look hash functions are not random +it's a hash function by the way let me + + align:start position:0% +it's a hash function by the way let me + + + align:start position:0% +it's a hash function by the way let me +say this Paradigm is used all over the + + align:start position:0% +say this Paradigm is used all over the + + + align:start position:0% +say this Paradigm is used all over the +place it's a very popular Paradigm it's + + align:start position:0% +place it's a very popular Paradigm it's + + + align:start position:0% +place it's a very popular Paradigm it's +used a lot in in signature schemes and + + align:start position:0% +used a lot in in signature schemes and + + + align:start position:0% +used a lot in in signature schemes and +also in in uh um proof systems it's used + + align:start position:0% +also in in uh um proof systems it's used + + + align:start position:0% +also in in uh um proof systems it's used +all over the place and which hash + + align:start position:0% +all over the place and which hash + + + align:start position:0% +all over the place and which hash +function is used some of the Shelf hash + + align:start position:0% +function is used some of the Shelf hash + + + align:start position:0% +function is used some of the Shelf hash +function sh 250 six like + + align:start position:0% +function sh 250 six like + + + align:start position:0% +function sh 250 six like +these engineered type you know hash + + align:start position:0% +these engineered type you know hash + + + align:start position:0% +these engineered type you know hash +function that are + + align:start position:0% +function that are + + + align:start position:0% +function that are +optimized so is it secure with shot + + align:start position:0% +optimized so is it secure with shot + + + align:start position:0% +optimized so is it secure with shot +256 it's definitely not random + + align:start position:0% +256 it's definitely not random + + + align:start position:0% +256 it's definitely not random +it's so we actually don't know that so + + align:start position:0% +it's so we actually don't know that so + + + align:start position:0% +it's so we actually don't know that so +let me be honest that is it + + align:start position:0% +let me be honest that is it + + + align:start position:0% +let me be honest that is it +secure I don't + + align:start position:0% +secure I don't + + + align:start position:0% +secure I don't +know + + align:start position:0% + + + + align:start position:0% + +yeah extension + + align:start position:0% + + + + align:start position:0% + +yeah right yeah you right right right + + align:start position:0% +yeah right yeah you right right right + + + align:start position:0% +yeah right yeah you right right right +right right so actually let me good so + + align:start position:0% +right right so actually let me good so + + + align:start position:0% +right right so actually let me good so +let me just say a few + + align:start position:0% + + + + align:start position:0% + +things okay maybe I'll cut to just to + + align:start position:0% +things okay maybe I'll cut to just to + + + align:start position:0% +things okay maybe I'll cut to just to +the + + align:start position:0% +the + + + align:start position:0% +the +chase I do know let me tell you it's not + + align:start position:0% +chase I do know let me tell you it's not + + + align:start position:0% +chase I do know let me tell you it's not +necessarily secure actually + + align:start position:0% +necessarily secure actually + + + align:start position:0% +necessarily secure actually +unfortunately we have counter examples + + align:start position:0% +unfortunately we have counter examples + + + align:start position:0% +unfortunately we have counter examples +so I said this is used in practice all + + align:start position:0% +so I said this is used in practice all + + + align:start position:0% +so I said this is used in practice all +the time you know it's uh one of the + + align:start position:0% +the time you know it's uh one of the + + + align:start position:0% +the time you know it's uh one of the +great inventions of cryptography is it + + align:start position:0% +great inventions of cryptography is it + + + align:start position:0% +great inventions of cryptography is it +secure + + align:start position:0% +secure + + + align:start position:0% +secure +no okay so what do I mean by no okay let + + align:start position:0% +no okay so what do I mean by no okay let + + + align:start position:0% +no okay so what do I mean by no okay let +me is it always secure no so yeah let me + + align:start position:0% +me is it always secure no so yeah let me + + + align:start position:0% +me is it always secure no so yeah let me +say let me take back my know thing is it + + align:start position:0% +say let me take back my know thing is it + + + align:start position:0% +say let me take back my know thing is it +always secure is it always the case that + + align:start position:0% +always secure is it always the case that + + + align:start position:0% +always secure is it always the case that +when you start with an + + align:start position:0% +when you start with an + + + align:start position:0% +when you start with an +interactive protocol and convert public + + align:start position:0% +interactive protocol and convert public + + + align:start position:0% +interactive protocol and convert public +coin and you apply is it always secure + + align:start position:0% +coin and you apply is it always secure + + + align:start position:0% +coin and you apply is it always secure +no moreover let me tell you we have + + align:start position:0% +no moreover let me tell you we have + + + align:start position:0% +no moreover let me tell you we have +protocols so that no matter which has + + align:start position:0% +protocols so that no matter which has + + + align:start position:0% +protocols so that no matter which has +family you use for for all half families + + align:start position:0% +family you use for for all half families + + + align:start position:0% +family you use for for all half families +the protocol becomes + + align:start position:0% +the protocol becomes + + + align:start position:0% +the protocol becomes +insecure hey let me tell you even more + + align:start position:0% +insecure hey let me tell you even more + + + align:start position:0% +insecure hey let me tell you even more +than that that will kind of really + + align:start position:0% +than that that will kind of really + + + align:start position:0% +than that that will kind of really +you'll be + + align:start position:0% +you'll be + + + align:start position:0% +you'll be +mad you know the K mikali + + align:start position:0% +mad you know the K mikali + + + align:start position:0% +mad you know the K mikali +protocol that we kind of built + + align:start position:0% +protocol that we kind of built + + + align:start position:0% +protocol that we kind of built +up even that's not secure the the F + + align:start position:0% +up even that's not secure the the F + + + align:start position:0% +up even that's not secure the the F +won't be secure on it but this let me + + align:start position:0% +won't be secure on it but this let me + + + align:start position:0% +won't be secure on it but this let me +actually put an Asters + + align:start position:0% +actually put an Asters + + + align:start position:0% +actually put an Asters +there it's what okay so let me let me + + align:start position:0% +there it's what okay so let me let me + + + align:start position:0% +there it's what okay so let me let me +tell you what's known about the + + align:start position:0% +tell you what's known about the + + + align:start position:0% +tell you what's known about the +insecurity + + align:start position:0% +insecurity + + + align:start position:0% +insecurity +of the F Paradigm for this protocol what + + align:start position:0% +of the F Paradigm for this protocol what + + + align:start position:0% +of the F Paradigm for this protocol what +is known is there are some contrived so + + align:start position:0% +is known is there are some contrived so + + + align:start position:0% +is known is there are some contrived so +the F the KE mikali protocol says take + + align:start position:0% +the F the KE mikali protocol says take + + + align:start position:0% +the F the KE mikali protocol says take +any hash function that's Collision + + align:start position:0% +any hash function that's Collision + + + align:start position:0% +any hash function that's Collision +resistance and uh and take any + + align:start position:0% +resistance and uh and take any + + + align:start position:0% +resistance and uh and take any +PCP we get + + align:start position:0% +PCP we get + + + align:start position:0% +PCP we get +tness there are examples of specific + + align:start position:0% +tness there are examples of specific + + + align:start position:0% +tness there are examples of specific +hash functions or specific pcps that are + + align:start position:0% +hash functions or specific pcps that are + + + align:start position:0% +hash functions or specific pcps that are +sound of course because it's so I mean + + align:start position:0% +sound of course because it's so I mean + + + align:start position:0% +sound of course because it's so I mean +there are example of collision resistant + + align:start position:0% +there are example of collision resistant + + + align:start position:0% +there are example of collision resistant +hash functions and pcps such that this + + align:start position:0% +hash functions and pcps such that this + + + align:start position:0% +hash functions and pcps such that this +of course it sound it sounds for any + + align:start position:0% +of course it sound it sounds for any + + + align:start position:0% +of course it sound it sounds for any +Collision hash function PCP but such + + align:start position:0% +Collision hash function PCP but such + + + align:start position:0% +Collision hash function PCP but such +that no matter which hash function you + + align:start position:0% +that no matter which hash function you + + + align:start position:0% +that no matter which hash function you +use for the phia this will be insecure + + align:start position:0% +use for the phia this will be insecure + + + align:start position:0% +use for the phia this will be insecure +not + + align:start position:0% +not + + + align:start position:0% +not +sound no matter what you + + align:start position:0% + + + + align:start position:0% + +use + + align:start position:0% +use + + + align:start position:0% +use +yeah what break yeah I I'll say a little + + align:start position:0% +yeah what break yeah I I'll say a little + + + align:start position:0% +yeah what break yeah I I'll say a little +bit what break + + align:start position:0% +bit what break + + + align:start position:0% +bit what break +in a second yeah example or okay good + + align:start position:0% +in a second yeah example or okay good + + + align:start position:0% +in a second yeah example or okay good +good good same question so the example + + align:start position:0% +good good same question so the example + + + align:start position:0% +good good same question so the example +for why it so why it breaks the example + + align:start position:0% +for why it so why it breaks the example + + + align:start position:0% +for why it so why it breaks the example +for why it break is very contrived + + align:start position:0% +for why it break is very contrived + + + align:start position:0% +for why it break is very contrived +actually so that's why am is the message + + align:start position:0% +actually so that's why am is the message + + + align:start position:0% +actually so that's why am is the message +here don't use f CH we have a break no + + align:start position:0% +here don't use f CH we have a break no + + + align:start position:0% +here don't use f CH we have a break no +that's not the message you should use f + + align:start position:0% +that's not the message you should use f + + + align:start position:0% +that's not the message you should use f +because in practice it works very well I + + align:start position:0% +because in practice it works very well I + + + align:start position:0% +because in practice it works very well I +don't have a single instance that people + + align:start position:0% +don't have a single instance that people + + + align:start position:0% +don't have a single instance that people +used F practice and it broke so it's a + + align:start position:0% +used F practice and it broke so it's a + + + align:start position:0% +used F practice and it broke so it's a +great paradigm use + + align:start position:0% +great paradigm use + + + align:start position:0% +great paradigm use +it can we come up with a general proof + + align:start position:0% +it can we come up with a general proof + + + align:start position:0% +it can we come up with a general proof +of security no because we have counter + + align:start position:0% +of security no because we have counter + + + align:start position:0% +of security no because we have counter +examples so what did we learn okay so + + align:start position:0% +examples so what did we learn okay so + + + align:start position:0% +examples so what did we learn okay so +maybe I'll start by saying I'll say very + + align:start position:0% +maybe I'll start by saying I'll say very + + + align:start position:0% +maybe I'll start by saying I'll say very +very high level not in detail but about + + align:start position:0% +very high level not in detail but about + + + align:start position:0% +very high level not in detail but about +the counter examples okay how can we + + align:start position:0% +the counter examples okay how can we + + + align:start position:0% +the counter examples okay how can we +build counter examples and as opposed to + + align:start position:0% +build counter examples and as opposed to + + + align:start position:0% +build counter examples and as opposed to +going to the K mikali protocol because + + align:start position:0% +going to the K mikali protocol because + + + align:start position:0% +going to the K mikali protocol because +there you need to work a little harder + + align:start position:0% +there you need to work a little harder + + + align:start position:0% +there you need to work a little harder +to fit it in uh I'll say a word how you + + align:start position:0% +to fit it in uh I'll say a word how you + + + align:start position:0% +to fit it in uh I'll say a word how you +fit it in there too but the idea is the + + align:start position:0% +fit it in there too but the idea is the + + + align:start position:0% +fit it in there too but the idea is the +foll let me try to give you a a proof + + align:start position:0% +foll let me try to give you a a proof + + + align:start position:0% +foll let me try to give you a a proof +that is or an interactive protocol that + + align:start position:0% +that is or an interactive protocol that + + + align:start position:0% +that is or an interactive protocol that +is sound but when you convert it to uh + + align:start position:0% +is sound but when you convert it to uh + + + align:start position:0% +is sound but when you convert it to uh +when you apply F soundness + + align:start position:0% +when you apply F soundness + + + align:start position:0% +when you apply F soundness +breaks so the idea is the following it's + + align:start position:0% +breaks so the idea is the following it's + + + align:start position:0% +breaks so the idea is the following it's +going to be a very contrived protocol + + align:start position:0% +going to be a very contrived protocol + + + align:start position:0% +going to be a very contrived protocol +okay so my what I want to do is + + align:start position:0% +okay so my what I want to do is + + + align:start position:0% +okay so my what I want to do is +construct a contrived + + align:start position:0% + + + + align:start position:0% + +protocol that is sound + + align:start position:0% +protocol that is sound + + + align:start position:0% +protocol that is sound +but when you apply F no matter which + + align:start position:0% +but when you apply F no matter which + + + align:start position:0% +but when you apply F no matter which +hash function you use it will + + align:start position:0% +hash function you use it will + + + align:start position:0% +hash function you use it will +break and intuitively the contri + + align:start position:0% +break and intuitively the contri + + + align:start position:0% +break and intuitively the contri +protocol is the following take any sound + + align:start position:0% +protocol is the following take any sound + + + align:start position:0% +protocol is the following take any sound +protocol for example f for example kilan + + align:start position:0% +protocol for example f for example kilan + + + align:start position:0% +protocol for example f for example kilan +mikali whatever or gkr whatever sound + + align:start position:0% +mikali whatever or gkr whatever sound + + + align:start position:0% +mikali whatever or gkr whatever sound +protocol you like and I'm going to + + align:start position:0% +protocol you like and I'm going to + + + align:start position:0% +protocol you like and I'm going to +change it I'm going to tweak a little + + align:start position:0% +change it I'm going to tweak a little + + + align:start position:0% +change it I'm going to tweak a little +bit that the sound will still remain I'm + + align:start position:0% +bit that the sound will still remain I'm + + + align:start position:0% +bit that the sound will still remain I'm +I'm going to tweak it so that I the + + align:start position:0% +I'm going to tweak it so that I the + + + align:start position:0% +I'm going to tweak it so that I the +soundness will still + + align:start position:0% +soundness will still + + + align:start position:0% +soundness will still +hold but on the twick protocol when you + + align:start position:0% +hold but on the twick protocol when you + + + align:start position:0% +hold but on the twick protocol when you +apply for will + + align:start position:0% +apply for will + + + align:start position:0% +apply for will +fail okay so start with PV for example + + align:start position:0% +fail okay so start with PV for example + + + align:start position:0% +fail okay so start with PV for example +gkr for example k m whatever you like + + align:start position:0% +gkr for example k m whatever you like + + + align:start position:0% +gkr for example k m whatever you like +and I'm gonna kind of tweak it a little + + align:start position:0% +and I'm gonna kind of tweak it a little + + + align:start position:0% +and I'm gonna kind of tweak it a little +bit how am I going to tweak it I'm gonna + + align:start position:0% +bit how am I going to tweak it I'm gonna + + + align:start position:0% +bit how am I going to tweak it I'm gonna +say tell the tell the verifier you know + + align:start position:0% +say tell the tell the verifier you know + + + align:start position:0% +say tell the tell the verifier you know +what accept if you accept it before but + + align:start position:0% +what accept if you accept it before but + + + align:start position:0% +what accept if you accept it before but +accept also if something very weird + + align:start position:0% +accept also if something very weird + + + align:start position:0% +accept also if something very weird +happens but don't worry it will never + + align:start position:0% +happens but don't worry it will never + + + align:start position:0% +happens but don't worry it will never +happen Okay when else are we going to + + align:start position:0% +happen Okay when else are we going to + + + align:start position:0% +happen Okay when else are we going to +accept so remember the verifier let's + + align:start position:0% +accept so remember the verifier let's + + + align:start position:0% +accept so remember the verifier let's +say he sends kind of a random beta + + align:start position:0% + + + + align:start position:0% + +if the prover let's say ahead of time + + align:start position:0% +if the prover let's say ahead of time + + + align:start position:0% +if the prover let's say ahead of time +guessed your beta he told you I know how + + align:start position:0% +guessed your beta he told you I know how + + + align:start position:0% +guessed your beta he told you I know how +you're going Compu your beta so if the + + align:start position:0% +you're going Compu your beta so if the + + + align:start position:0% +you're going Compu your beta so if the +pro ahead of time sent you kind of um + + align:start position:0% +pro ahead of time sent you kind of um + + + align:start position:0% +pro ahead of time sent you kind of um +sent you a message that will kind of + + align:start position:0% +sent you a message that will kind of + + + align:start position:0% +sent you a message that will kind of +tell say kind of I can + + align:start position:0% +tell say kind of I can + + + align:start position:0% +tell say kind of I can +predict beta and kind of will predict + + align:start position:0% +predict beta and kind of will predict + + + align:start position:0% +predict beta and kind of will predict +bet ahead of time then you accept him + + align:start position:0% +bet ahead of time then you accept him + + + align:start position:0% +bet ahead of time then you accept him +this is random what's the property that + + align:start position:0% +this is random what's the property that + + + align:start position:0% +this is random what's the property that +you can prct my bet + + align:start position:0% +you can prct my bet + + + align:start position:0% +you can prct my bet +if beta is like random and 0 one to the + + align:start position:0% +if beta is like random and 0 one to the + + + align:start position:0% +if beta is like random and 0 one to the +Lambda there's no way you can predict it + + align:start position:0% +Lambda there's no way you can predict it + + + align:start position:0% +Lambda there's no way you can predict it +so if by any chance you predict I'm + + align:start position:0% +so if by any chance you predict I'm + + + align:start position:0% +so if by any chance you predict I'm +going to you know you can won the + + align:start position:0% +going to you know you can won the + + + align:start position:0% +going to you know you can won the +lottery I'll accept you no matter I + + align:start position:0% +lottery I'll accept you no matter I + + + align:start position:0% +lottery I'll accept you no matter I +don't care if that's in the language or + + align:start position:0% +don't care if that's in the language or + + + align:start position:0% +don't care if that's in the language or +not it only adds like a negligable + + align:start position:0% +not it only adds like a negligable + + + align:start position:0% +not it only adds like a negligable +probability of you know because the + + align:start position:0% +probability of you know because the + + + align:start position:0% +probability of you know because the +probability that you can predict beta is + + align:start position:0% +probability that you can predict beta is + + + align:start position:0% +probability that you can predict beta is +one over two to the + + align:start position:0% + + + + align:start position:0% + +beta now what happens in the F meal + + align:start position:0% +beta now what happens in the F meal + + + align:start position:0% +beta now what happens in the F meal +Paradigm oh I can tell you oh I know bet + + align:start position:0% +Paradigm oh I can tell you oh I know bet + + + align:start position:0% +Paradigm oh I can tell you oh I know bet +I'm I can predict it I'm going to tell + + align:start position:0% +I'm I can predict it I'm going to tell + + + align:start position:0% +I'm I can predict it I'm going to tell +you exactly how I predict it beta is + + align:start position:0% +you exactly how I predict it beta is + + + align:start position:0% +you exactly how I predict it beta is +going to be eval hash key and this + + align:start position:0% + + + + align:start position:0% + +message that's the idea now to implement + + align:start position:0% +message that's the idea now to implement + + + align:start position:0% +message that's the idea now to implement +this idea it's harder it requires some + + align:start position:0% +this idea it's harder it requires some + + + align:start position:0% +this idea it's harder it requires some +work I'll tell you why this idea is not + + align:start position:0% +work I'll tell you why this idea is not + + + align:start position:0% +work I'll tell you why this idea is not +trivially + + align:start position:0% +trivially + + + align:start position:0% +trivially +implemented + + align:start position:0% +implemented + + + align:start position:0% +implemented +because when we do F we say we + + align:start position:0% +because when we do F we say we + + + align:start position:0% +because when we do F we say we +start with a protocol and now the + + align:start position:0% +start with a protocol and now the + + + align:start position:0% +start with a protocol and now the +question question is does there exist a + + align:start position:0% +question question is does there exist a + + + align:start position:0% +question question is does there exist a +hash a f has family for which it's + + align:start position:0% +hash a f has family for which it's + + + align:start position:0% +hash a f has family for which it's +secure now we start with a protocol this + + align:start position:0% +secure now we start with a protocol this + + + align:start position:0% +secure now we start with a protocol this +protocol can say can say Okay Alpha is + + align:start position:0% +protocol can say can say Okay Alpha is + + + align:start position:0% +protocol can say can say Okay Alpha is +Hash key for + + align:start position:0% +Hash key for + + + align:start position:0% +Hash key for +example and then you accept if you + + align:start position:0% +example and then you accept if you + + + align:start position:0% +example and then you accept if you +originally accepted or if eval of hash + + align:start position:0% +originally accepted or if eval of hash + + + align:start position:0% +originally accepted or if eval of hash +key of alpha which is also hash key is + + align:start position:0% +key of alpha which is also hash key is + + + align:start position:0% +key of alpha which is also hash key is +equal to Beta now this will not happen + + align:start position:0% +equal to Beta now this will not happen + + + align:start position:0% +equal to Beta now this will not happen +but in the future me it will happen + + align:start position:0% +but in the future me it will happen + + + align:start position:0% +but in the future me it will happen +I'm going to just send the F in haski + + align:start position:0% +I'm going to just send the F in haski + + + align:start position:0% +I'm going to just send the F in haski +that's what I + + align:start position:0% +that's what I + + + align:start position:0% +that's what I +do okay but then someone will say okay + + align:start position:0% +do okay but then someone will say okay + + + align:start position:0% +do okay but then someone will say okay +so you give me a protocol what is the + + align:start position:0% +so you give me a protocol what is the + + + align:start position:0% +so you give me a protocol what is the +length of your Alpha it's Lambda bits + + align:start position:0% +length of your Alpha it's Lambda bits + + + align:start position:0% +length of your Alpha it's Lambda bits +I'm going to use a hash function that + + align:start position:0% +I'm going to use a hash function that + + + align:start position:0% +I'm going to use a hash function that +the hash key is longer and now you can't + + align:start position:0% +the hash key is longer and now you can't + + + align:start position:0% +the hash key is longer and now you can't +send it because here I'm like I'll send + + align:start position:0% +send it because here I'm like I'll send + + + align:start position:0% +send it because here I'm like I'll send +the hash + + align:start position:0% +the hash + + + align:start position:0% +the hash +key so then you need to use a hash to + + align:start position:0% +key so then you need to use a hash to + + + align:start position:0% +key so then you need to use a hash to +kind of Squish this hash key it it's + + align:start position:0% +kind of Squish this hash key it it's + + + align:start position:0% +kind of Squish this hash key it it's +more + + align:start position:0% +more + + + align:start position:0% +more +complicated but the the basic idea + + align:start position:0% +complicated but the the basic idea + + + align:start position:0% +complicated but the the basic idea +is this does not work if somehow the + + align:start position:0% +is this does not work if somehow the + + + align:start position:0% +is this does not work if somehow the +verifier accepts you if you kind of + + align:start position:0% +verifier accepts you if you kind of + + + align:start position:0% +verifier accepts you if you kind of +convinced him that you can kind of + + align:start position:0% +convinced him that you can kind of + + + align:start position:0% +convinced him that you can kind of +predict his his beta that's really + + align:start position:0% +predict his his beta that's really + + + align:start position:0% +predict his his beta that's really +and so we can construct kind of + + align:start position:0% +and so we can construct kind of + + + align:start position:0% +and so we can construct kind of +contrived um protocols that achieve this + + align:start position:0% +contrived um protocols that achieve this + + + align:start position:0% +contrived um protocols that achieve this +or we can cont construct very contrived + + align:start position:0% +or we can cont construct very contrived + + + align:start position:0% +or we can cont construct very contrived +hash function that do this weird game + + align:start position:0% +hash function that do this weird game + + + align:start position:0% +hash function that do this weird game +inside the hash function like the hash + + align:start position:0% +inside the hash function like the hash + + + align:start position:0% +inside the hash function like the hash +function becomes trivial if you feed it + + align:start position:0% +function becomes trivial if you feed it + + + align:start position:0% +function becomes trivial if you feed it +something that kind of so so it requires + + align:start position:0% +something that kind of so so it requires + + + align:start position:0% +something that kind of so so it requires +more work but it's all very + + align:start position:0% +more work but it's all very + + + align:start position:0% +more work but it's all very +contrived okay so I hope I convinced you + + align:start position:0% +contrived okay so I hope I convinced you + + + align:start position:0% +contrived okay so I hope I convinced you +by with these examples the counter + + align:start position:0% +by with these examples the counter + + + align:start position:0% +by with these examples the counter +examples are so contrived so when you + + align:start position:0% +examples are so contrived so when you + + + align:start position:0% +examples are so contrived so when you +when you say oh we found the p is not + + align:start position:0% +when you say oh we found the p is not + + + align:start position:0% +when you say oh we found the p is not +secure and you show these example the + + align:start position:0% +secure and you show these example the + + + align:start position:0% +secure and you show these example the +reaction should be come on okay nobody + + align:start position:0% +reaction should be come on okay nobody + + + align:start position:0% +reaction should be come on okay nobody +uses these + + align:start position:0% +uses these + + + align:start position:0% +uses these +protocols but what it does tell us you + + align:start position:0% +protocols but what it does tell us you + + + align:start position:0% +protocols but what it does tell us you +can't apply F blind you can't okay what + + align:start position:0% +can't apply F blind you can't okay what + + + align:start position:0% +can't apply F blind you can't okay what +it does tell us is for all of us who are + + align:start position:0% +it does tell us is for all of us who are + + + align:start position:0% +it does tell us is for all of us who are +upset with trying to prove the Paradigm + + align:start position:0% +upset with trying to prove the Paradigm + + + align:start position:0% +upset with trying to prove the Paradigm +there's no General proof because we have + + align:start position:0% +there's no General proof because we have + + + align:start position:0% +there's no General proof because we have +counter examples at least + + align:start position:0% +counter examples at least + + + align:start position:0% +counter examples at least +that question you need to + + align:start position:0% + + + + align:start position:0% + +start great great question okay I that's + + align:start position:0% +start great great question okay I that's + + + align:start position:0% +start great great question okay I that's +my next so I I'll I'll uh + + align:start position:0% +my next so I I'll I'll uh + + + align:start position:0% +my next so I I'll I'll uh +yeah I'll the answer is yes but I'll + + align:start position:0% +yeah I'll the answer is yes but I'll + + + align:start position:0% +yeah I'll the answer is yes but I'll +I'll I'll talk about that next the + + align:start position:0% +I'll I'll talk about that next the + + + align:start position:0% +I'll I'll talk about that next the +question was about negligible soundness + + align:start position:0% +question was about negligible soundness + + + align:start position:0% +question was about negligible soundness +but we'll get to that next so any + + align:start position:0% +but we'll get to that next so any + + + align:start position:0% +but we'll get to that next so any +question though + + align:start position:0% +question though + + + align:start position:0% +question though +before okay so but you know still people + + align:start position:0% +before okay so but you know still people + + + align:start position:0% +before okay so but you know still people +use the F Paradigm and there's a + + align:start position:0% +use the F Paradigm and there's a + + + align:start position:0% +use the F Paradigm and there's a +question + + align:start position:0% +question + + + align:start position:0% +question +of is it sound for natural protocols is + + align:start position:0% +of is it sound for natural protocols is + + + align:start position:0% +of is it sound for natural protocols is +it + + align:start position:0% +it + + + align:start position:0% +it +sound and the answer is actually it + + align:start position:0% +sound and the answer is actually it + + + align:start position:0% +sound and the answer is actually it +would have been nice if we can come up + + align:start position:0% +would have been nice if we can come up + + + align:start position:0% +would have been nice if we can come up +with Pro nice protocols and say at least + + align:start position:0% +with Pro nice protocols and say at least + + + align:start position:0% +with Pro nice protocols and say at least +a large class of protocols and say yeah + + align:start position:0% +a large class of protocols and say yeah + + + align:start position:0% +a large class of protocols and say yeah +if you use this hash function this + + align:start position:0% +if you use this hash function this + + + align:start position:0% +if you use this hash function this +specific hash function which we know is + + align:start position:0% +specific hash function which we know is + + + align:start position:0% +specific hash function which we know is +Collision resistant under discret log or + + align:start position:0% +Collision resistant under discret log or + + + align:start position:0% +Collision resistant under discret log or +under some other + + align:start position:0% +under some other + + + align:start position:0% +under some other +then your scheme is sound that would be + + align:start position:0% +then your scheme is sound that would be + + + align:start position:0% +then your scheme is sound that would be +very + + align:start position:0% + + + + align:start position:0% + +nice we're still not there yet but we + + align:start position:0% +nice we're still not there yet but we + + + align:start position:0% +nice we're still not there yet but we +made a lot of progress in recent years + + align:start position:0% +made a lot of progress in recent years + + + align:start position:0% +made a lot of progress in recent years +and I want to tell you about the + + align:start position:0% +and I want to tell you about the + + + align:start position:0% +and I want to tell you about the +progress but before that the first way + + align:start position:0% +progress but before that the first way + + + align:start position:0% +progress but before that the first way +the first a + + align:start position:0% + + + + align:start position:0% + +a uh kind of way we try to analyze so + + align:start position:0% +a uh kind of way we try to analyze so + + + align:start position:0% +a uh kind of way we try to analyze so +the F gained popularity very quickly + + align:start position:0% +the F gained popularity very quickly + + + align:start position:0% +the F gained popularity very quickly +okay uh and because it's so simple and + + align:start position:0% +okay uh and because it's so simple and + + + align:start position:0% +okay uh and because it's so simple and +so efficient uh it became very very + + align:start position:0% +so efficient uh it became very very + + + align:start position:0% +so efficient uh it became very very +popular + + align:start position:0% +popular + + + align:start position:0% +popular +and people really wanted to understand + + align:start position:0% +and people really wanted to understand + + + align:start position:0% +and people really wanted to understand +its uh security is it sound is it not + + align:start position:0% +its uh security is it sound is it not + + + align:start position:0% +its uh security is it sound is it not +sound and then in + + align:start position:0% +sound and then in + + + align:start position:0% +sound and then in +93 Bela and rway introduced kind of an + + align:start position:0% +93 Bela and rway introduced kind of an + + + align:start position:0% +93 Bela and rway introduced kind of an +ideal model called the random Oracle + + align:start position:0% + + + + align:start position:0% + +model and this model said you know + + align:start position:0% +model and this model said you know + + + align:start position:0% +model and this model said you know +what by the way this was before we had + + align:start position:0% +what by the way this was before we had + + + align:start position:0% +what by the way this was before we had +any counter examples okay this model was + + align:start position:0% +any counter examples okay this model was + + + align:start position:0% +any counter examples okay this model was +introduced by Bel and rway in I believe + + align:start position:0% +introduced by Bel and rway in I believe + + + align:start position:0% +introduced by Bel and rway in I believe +80 uh + + align:start position:0% +80 uh + + + align:start position:0% +80 uh +93 this was before we knew any counter + + align:start position:0% +93 this was before we knew any counter + + + align:start position:0% +93 this was before we knew any counter +examples for the Paradigm and they I + + align:start position:0% +examples for the Paradigm and they I + + + align:start position:0% +examples for the Paradigm and they I +mean except for some which goes through + + align:start position:0% +mean except for some which goes through + + + align:start position:0% +mean except for some which goes through +your question Leo but I'm going to get + + align:start position:0% +your question Leo but I'm going to get + + + align:start position:0% +your question Leo but I'm going to get +to it and they wanted to ask can we + + align:start position:0% +to it and they wanted to ask can we + + + align:start position:0% +to it and they wanted to ask can we +prove security of of + + align:start position:0% +prove security of of + + + align:start position:0% +prove security of of +the uh what do we need about the hash + + align:start position:0% +the uh what do we need about the hash + + + align:start position:0% +the uh what do we need about the hash +function what properties do we need + + align:start position:0% +function what properties do we need + + + align:start position:0% +function what properties do we need +about the hash function to prove + + align:start position:0% +about the hash function to prove + + + align:start position:0% +about the hash function to prove +security and the first property they + + align:start position:0% +security and the first property they + + + align:start position:0% +security and the first property they +said you know what what if the hash + + align:start position:0% +said you know what what if the hash + + + align:start position:0% +said you know what what if the hash +function was completely + + align:start position:0% +function was completely + + + align:start position:0% +function was completely +random so when you use we use a specific + + align:start position:0% +random so when you use we use a specific + + + align:start position:0% +random so when you use we use a specific +there's a circuit that computes the hash + + align:start position:0% +there's a circuit that computes the hash + + + align:start position:0% +there's a circuit that computes the hash +function it's like a touring machine a + + align:start position:0% +function it's like a touring machine a + + + align:start position:0% +function it's like a touring machine a +polinomial Time touring machine or a + + align:start position:0% +polinomial Time touring machine or a + + + align:start position:0% +polinomial Time touring machine or a +polinomial size circuit takes a hash key + + align:start position:0% +polinomial size circuit takes a hash key + + + align:start position:0% +polinomial size circuit takes a hash key +and okay they say you know what what if + + align:start position:0% +and okay they say you know what what if + + + align:start position:0% +and okay they say you know what what if +the hash function is completely + + align:start position:0% +the hash function is completely + + + align:start position:0% +the hash function is completely +random Okay so the r welome model says + + align:start position:0% + + + + align:start position:0% + +suppose we + + align:start position:0% +suppose we + + + align:start position:0% +suppose we +apply Fe to + + align:start position:0% + + + + align:start position:0% + +Paradigm with + + align:start position:0% +Paradigm with + + + align:start position:0% +Paradigm with +truly + + align:start position:0% +truly + + + align:start position:0% +truly +random function + + align:start position:0% +random function + + + align:start position:0% +random function +H so this is completely completely + + align:start position:0% +H so this is completely completely + + + align:start position:0% +H so this is completely completely +random so what do I mean by completely + + align:start position:0% +random so what do I mean by completely + + + align:start position:0% +random so what do I mean by completely +random so now I + + align:start position:0% + + + + align:start position:0% + +guess let me + + align:start position:0% +guess let me + + + align:start position:0% +guess let me +instead of + + align:start position:0% +instead of + + + align:start position:0% +instead of +choosing a function from a + + align:start position:0% +choosing a function from a + + + align:start position:0% +choosing a function from a +family we don't choose a function and we + + align:start position:0% +family we don't choose a function and we + + + align:start position:0% +family we don't choose a function and we +just say suppose they have a truly + + align:start position:0% +just say suppose they have a truly + + + align:start position:0% +just say suppose they have a truly +random they have access to both of them + + align:start position:0% +random they have access to both of them + + + align:start position:0% +random they have access to both of them +to a truly truly random function and + + align:start position:0% +to a truly truly random function and + + + align:start position:0% +to a truly truly random function and +they can ask so when the prover computes + + align:start position:0% +they can ask so when the prover computes + + + align:start position:0% +they can ask so when the prover computes +Alpha he asks he has Oracle this + + align:start position:0% +Alpha he asks he has Oracle this + + + align:start position:0% +Alpha he asks he has Oracle this +function and he tells the function give + + align:start position:0% +function and he tells the function give + + + align:start position:0% +function and he tells the function give +me the function apply 2 x and Alpha and + + align:start position:0% +me the function apply 2 x and Alpha and + + + align:start position:0% +me the function apply 2 x and Alpha and +he gets back a beta and every time this + + align:start position:0% +he gets back a beta and every time this + + + align:start position:0% +he gets back a beta and every time this +hash this Oracle he gets a query he + + align:start position:0% +hash this Oracle he gets a query he + + + align:start position:0% +hash this Oracle he gets a query he +chooses a completely random so think of + + align:start position:0% +chooses a completely random so think of + + + align:start position:0% +chooses a completely random so think of +this as like a database of all like size + + align:start position:0% +this as like a database of all like size + + + align:start position:0% +this as like a database of all like size +two to the Lambda of all like just + + align:start position:0% +two to the Lambda of all like just + + + align:start position:0% +two to the Lambda of all like just +random random random elements a really + + align:start position:0% +random random random elements a really + + + align:start position:0% +random random random elements a really +really truly random + + align:start position:0% +really truly random + + + align:start position:0% +really truly random +function so now the question was okay if + + align:start position:0% +function so now the question was okay if + + + align:start position:0% +function so now the question was okay if +this is truly random now can we get + + align:start position:0% +this is truly random now can we get + + + align:start position:0% +this is truly random now can we get +security at least like that's the + + align:start position:0% +security at least like that's the + + + align:start position:0% +security at least like that's the +minimum and moreover it seem like the + + align:start position:0% +minimum and moreover it seem like the + + + align:start position:0% +minimum and moreover it seem like the +answer should be yes because in some + + align:start position:0% +answer should be yes because in some + + + align:start position:0% +answer should be yes because in some +sense what was their what was their + + align:start position:0% +sense what was their what was their + + + align:start position:0% +sense what was their what was their +intuition the intuition is what does it + + align:start position:0% +intuition the intuition is what does it + + + align:start position:0% +intuition the intuition is what does it +matter if you're talking to a verifier + + align:start position:0% +matter if you're talking to a verifier + + + align:start position:0% +matter if you're talking to a verifier +that gives you random queries or you're + + align:start position:0% +that gives you random queries or you're + + + align:start position:0% +that gives you random queries or you're +talking to in terms of the prover so the + + align:start position:0% +talking to in terms of the prover so the + + + align:start position:0% +talking to in terms of the prover so the +prover is trying to cheat what does it + + align:start position:0% +prover is trying to cheat what does it + + + align:start position:0% +prover is trying to cheat what does it +matter if he's talking to a verifier + + align:start position:0% +matter if he's talking to a verifier + + + align:start position:0% +matter if he's talking to a verifier +that give him kind of random vas or he's + + align:start position:0% +that give him kind of random vas or he's + + + align:start position:0% +that give him kind of random vas or he's +talking to a random function that gives + + align:start position:0% +talking to a random function that gives + + + align:start position:0% +talking to a random function that gives +them random betas both of them do random + + align:start position:0% +them random betas both of them do random + + + align:start position:0% +them random betas both of them do random +betas what's the + + align:start position:0% +betas what's the + + + align:start position:0% +betas what's the +difference so it should at least be + + align:start position:0% +difference so it should at least be + + + align:start position:0% +difference so it should at least be +secure in the random Oracle model let's + + align:start position:0% +secure in the random Oracle model let's + + + align:start position:0% +secure in the random Oracle model let's +first establish + + align:start position:0% +first establish + + + align:start position:0% +first establish +that so is it secure in the random + + align:start position:0% +that so is it secure in the random + + + align:start position:0% +that so is it secure in the random +Oracle model + + align:start position:0% +Oracle model + + + align:start position:0% +Oracle model +no and this goes to Leo's + + align:start position:0% +no and this goes to Leo's + + + align:start position:0% +no and this goes to Leo's +question and I'm going to tell you why + + align:start position:0% +question and I'm going to tell you why + + + align:start position:0% +question and I'm going to tell you why +it's not secured the random oracal model + + align:start position:0% +it's not secured the random oracal model + + + align:start position:0% +it's not secured the random oracal model +and actually let me take a little + + align:start position:0% +and actually let me take a little + + + align:start position:0% +and actually let me take a little +detour and uh tell you I'll I'll show + + align:start position:0% +detour and uh tell you I'll I'll show + + + align:start position:0% +detour and uh tell you I'll I'll show +why it's not secure in the random oracal + + align:start position:0% +why it's not secure in the random oracal + + + align:start position:0% +why it's not secure in the random oracal +model via a little protocol + + align:start position:0% +model via a little protocol + + + align:start position:0% +model via a little protocol +this protocol actually is going to be + + align:start position:0% +this protocol actually is going to be + + + align:start position:0% +this protocol actually is going to be +useful because actually later we will + + align:start position:0% +useful because actually later we will + + + align:start position:0% +useful because actually later we will +show that the f is sound for this + + align:start position:0% +show that the f is sound for this + + + align:start position:0% +show that the f is sound for this +protocol it's kind of weird but let's + + align:start position:0% +protocol it's kind of weird but let's + + + align:start position:0% +protocol it's kind of weird but let's +this protocol by the way is very + + align:start position:0% +this protocol by the way is very + + + align:start position:0% +this protocol by the way is very +important + + align:start position:0% +important + + + align:start position:0% +important +protocol so so let me quickly do let me + + align:start position:0% +protocol so so let me quickly do let me + + + align:start position:0% +protocol so so let me quickly do let me +do a little detour I think it's a really + + align:start position:0% +do a little detour I think it's a really + + + align:start position:0% +do a little detour I think it's a really +interesting detour so I hope you enjoy + + align:start position:0% +interesting detour so I hope you enjoy + + + align:start position:0% +interesting detour so I hope you enjoy +it um it takes us a little bit into the + + align:start position:0% +it um it takes us a little bit into the + + + align:start position:0% +it um it takes us a little bit into the +land of + + align:start position:0% +land of + + + align:start position:0% +land of +cryptography but not too bad + + align:start position:0% + + + + align:start position:0% + +a little further than we went so far so + + align:start position:0% +a little further than we went so far so + + + align:start position:0% +a little further than we went so far so +far we just talked about hash + + align:start position:0% +far we just talked about hash + + + align:start position:0% +far we just talked about hash +functions okay + + align:start position:0% + + + + align:start position:0% + +so what I'm going to say now is going to + + align:start position:0% +so what I'm going to say now is going to + + + align:start position:0% +so what I'm going to say now is going to +be a little bit of a high level + + align:start position:0% +be a little bit of a high level + + + align:start position:0% +be a little bit of a high level +a so a protocol that I want + + align:start position:0% +a so a protocol that I want + + + align:start position:0% +a so a protocol that I want +to talk about is actually a zero + + align:start position:0% +to talk about is actually a zero + + + align:start position:0% +to talk about is actually a zero +knowledge protocol so you know so far we + + align:start position:0% +knowledge protocol so you know so far we + + + align:start position:0% +knowledge protocol so you know so far we +just talked about verification + + align:start position:0% +just talked about verification + + + align:start position:0% +just talked about verification +verification you know synness and + + align:start position:0% +verification you know synness and + + + align:start position:0% +verification you know synness and +efficiency but uh as I mentioned + + align:start position:0% +efficiency but uh as I mentioned + + + align:start position:0% +efficiency but uh as I mentioned +interactive protocols were actually + + align:start position:0% +interactive protocols were actually + + + align:start position:0% +interactive protocols were actually +invented for the sake of zero + + align:start position:0% +invented for the sake of zero + + + align:start position:0% +invented for the sake of zero +knowledge so what was the goal the goal + + align:start position:0% +knowledge so what was the goal the goal + + + align:start position:0% +knowledge so what was the goal the goal +was forget about sness now it was not at + + align:start position:0% +was forget about sness now it was not at + + + align:start position:0% +was forget about sness now it was not at +all about sness all we wanted is a + + align:start position:0% +all about sness all we wanted is a + + + align:start position:0% +all about sness all we wanted is a +prover that has let's say a witness for + + align:start position:0% +prover that has let's say a witness for + + + align:start position:0% +prover that has let's say a witness for +some there's some there's some language + + align:start position:0% +some there's some there's some language + + + align:start position:0% +some there's some there's some language +and let's say the language we're going + + align:start position:0% +and let's say the language we're going + + + align:start position:0% +and let's say the language we're going +to be interested for today just as an + + align:start position:0% +to be interested for today just as an + + + align:start position:0% +to be interested for today just as an +example is the language of hamiltonian + + align:start position:0% +example is the language of hamiltonian + + + align:start position:0% +example is the language of hamiltonian +cycle + + align:start position:0% + + + + align:start position:0% + +that's just an example so this language + + align:start position:0% +that's just an example so this language + + + align:start position:0% +that's just an example so this language +consists of + + align:start position:0% +consists of + + + align:start position:0% +consists of +graphs so this is the language that + + align:start position:0% +graphs so this is the language that + + + align:start position:0% +graphs so this is the language that +consists of all graphs graph is just + + align:start position:0% +consists of all graphs graph is just + + + align:start position:0% +consists of all graphs graph is just +consists of nodes and + + align:start position:0% +consists of nodes and + + + align:start position:0% +consists of nodes and +edges such that this graph has a + + align:start position:0% +edges such that this graph has a + + + align:start position:0% +edges such that this graph has a +hamiltonian cycle so that g + + align:start position:0% +hamiltonian cycle so that g + + + align:start position:0% +hamiltonian cycle so that g +has + + align:start position:0% +has + + + align:start position:0% +has +a + + align:start position:0% +a + + + align:start position:0% +a +hamiltonian cycle what this means is + + align:start position:0% +hamiltonian cycle what this means is + + + align:start position:0% +hamiltonian cycle what this means is +just + + align:start position:0% + + + + align:start position:0% + +you can just there's a kind of a a cycle + + align:start position:0% +you can just there's a kind of a a cycle + + + align:start position:0% +you can just there's a kind of a a cycle +of all the nodes so it means that + + align:start position:0% +of all the nodes so it means that + + + align:start position:0% +of all the nodes so it means that +there's a cycle of all the nodes so + + align:start position:0% +there's a cycle of all the nodes so + + + align:start position:0% +there's a cycle of all the nodes so +let's say you start with node i1 + + align:start position:0% +let's say you start with node i1 + + + align:start position:0% +let's say you start with node i1 +I2 up to i n and then go up to I in said + + align:start position:0% +I2 up to i n and then go up to I in said + + + align:start position:0% +I2 up to i n and then go up to I in said +that there's an edge here Edge Edge Edge + + align:start position:0% +that there's an edge here Edge Edge Edge + + + align:start position:0% +that there's an edge here Edge Edge Edge +Edge Edge an edge all the way back + + align:start position:0% +Edge Edge an edge all the way back + + + align:start position:0% +Edge Edge an edge all the way back +that's that means it if if you can if + + align:start position:0% +that's that means it if if you can if + + + align:start position:0% +that's that means it if if you can if +there's some such um uh uh a setting of + + align:start position:0% +there's some such um uh uh a setting of + + + align:start position:0% +there's some such um uh uh a setting of +The nodes for which you can kind of set + + align:start position:0% +The nodes for which you can kind of set + + + align:start position:0% +The nodes for which you can kind of set +them in a way that there's edges that + + align:start position:0% +them in a way that there's edges that + + + align:start position:0% +them in a way that there's edges that +kind of complete a cycle then we say the + + align:start position:0% +kind of complete a cycle then we say the + + + align:start position:0% +kind of complete a cycle then we say the +graph has the hamiltonian cycle okay + + align:start position:0% +graph has the hamiltonian cycle okay + + + align:start position:0% +graph has the hamiltonian cycle okay +this language is NP complete okay now so + + align:start position:0% +this language is NP complete okay now so + + + align:start position:0% +this language is NP complete okay now so +now going back what is a zero knowledge + + align:start position:0% +now going back what is a zero knowledge + + + align:start position:0% +now going back what is a zero knowledge +proof a zero knowledge proof is a way I + + align:start position:0% +proof a zero knowledge proof is a way I + + + align:start position:0% +proof a zero knowledge proof is a way I +want to convince you that a graph G has + + align:start position:0% +want to convince you that a graph G has + + + align:start position:0% +want to convince you that a graph G has +aonian cycle now I can give you the + + align:start position:0% +aonian cycle now I can give you the + + + align:start position:0% +aonian cycle now I can give you the +cycle I can give you see here's the node + + align:start position:0% +cycle I can give you see here's the node + + + align:start position:0% +cycle I can give you see here's the node +you can look there's a cycle there but I + + align:start position:0% +you can look there's a cycle there but I + + + align:start position:0% +you can look there's a cycle there but I +don't want to give you any information I + + align:start position:0% +don't want to give you any information I + + + align:start position:0% +don't want to give you any information I +don't want you to learn anything I don't + + align:start position:0% +don't want you to learn anything I don't + + + align:start position:0% +don't want you to learn anything I don't +want you to to find the cycle I don't + + align:start position:0% +want you to to find the cycle I don't + + + align:start position:0% +want you to to find the cycle I don't +want to reveal any information but I + + align:start position:0% +want to reveal any information but I + + + align:start position:0% +want to reveal any information but I +want to convince you that it has a + + align:start position:0% +want to convince you that it has a + + + align:start position:0% +want to convince you that it has a +hamiltonian + + align:start position:0% + + + + align:start position:0% + +cycle how do I do that so this kind of + + align:start position:0% +cycle how do I do that so this kind of + + + align:start position:0% +cycle how do I do that so this kind of +so there's a a celebrated result it + + align:start position:0% +so there's a a celebrated result it + + + align:start position:0% +so there's a a celebrated result it +started with gasali and ROV in mid 80s + + align:start position:0% +started with gasali and ROV in mid 80s + + + align:start position:0% +started with gasali and ROV in mid 80s +and uh where they defined this notion of + + align:start position:0% +and uh where they defined this notion of + + + align:start position:0% +and uh where they defined this notion of +zero knowledge uh and constructed some + + align:start position:0% +zero knowledge uh and constructed some + + + align:start position:0% +zero knowledge uh and constructed some +protocols but later very shortly later + + align:start position:0% +protocols but later very shortly later + + + align:start position:0% +protocols but later very shortly later +uh uh by gold gold mikali and vigone + + align:start position:0% +uh uh by gold gold mikali and vigone + + + align:start position:0% +uh uh by gold gold mikali and vigone +showed that actually any NP language has + + align:start position:0% +showed that actually any NP language has + + + align:start position:0% +showed that actually any NP language has +a zero knowledge + + align:start position:0% +a zero knowledge + + + align:start position:0% +a zero knowledge +proof okay let me give you one specific + + align:start position:0% +proof okay let me give you one specific + + + align:start position:0% +proof okay let me give you one specific +zero knowledge proof for the aonian uh + + align:start position:0% +zero knowledge proof for the aonian uh + + + align:start position:0% +zero knowledge proof for the aonian uh +cycle language uh and this is Du to blam + + align:start position:0% +cycle language uh and this is Du to blam + + + align:start position:0% +cycle language uh and this is Du to blam +okay so I'll show you the the proof it's + + align:start position:0% +okay so I'll show you the the proof it's + + + align:start position:0% +okay so I'll show you the the proof it's +very very nice okay and it's going to be + + align:start position:0% +very very nice okay and it's going to be + + + align:start position:0% +very very nice okay and it's going to be +useful for us uh to show NE to show why + + align:start position:0% +useful for us uh to show NE to show why + + + align:start position:0% +useful for us uh to show NE to show why +the random oral model fails and then + + align:start position:0% +the random oral model fails and then + + + align:start position:0% +the random oral model fails and then +also to show the security of the F so + + align:start position:0% +also to show the security of the F so + + + align:start position:0% +also to show the security of the F so +this is actually we'll get back to this + + align:start position:0% +this is actually we'll get back to this + + + align:start position:0% +this is actually we'll get back to this +protocol okay so what is this protocol + + align:start position:0% +protocol okay so what is this protocol + + + align:start position:0% +protocol okay so what is this protocol +there's a prover in a + + align:start position:0% +there's a prover in a + + + align:start position:0% +there's a prover in a +verifier the idea is the following the + + align:start position:0% +verifier the idea is the following the + + + align:start position:0% +verifier the idea is the following the +prover will he knows he will first he + + align:start position:0% +prover will he knows he will first he + + + align:start position:0% +prover will he knows he will first he +has a + + align:start position:0% +has a + + + align:start position:0% +has a +g the first thing he's going to permute + + align:start position:0% +g the first thing he's going to permute + + + align:start position:0% +g the first thing he's going to permute +completely permute that the nodes okay + + align:start position:0% +completely permute that the nodes okay + + + align:start position:0% +completely permute that the nodes okay +so he's going to choose a random + + align:start position:0% +so he's going to choose a random + + + align:start position:0% +so he's going to choose a random +permutation Pi let's say n is the number + + align:start position:0% +permutation Pi let's say n is the number + + + align:start position:0% +permutation Pi let's say n is the number +denoted by + + align:start position:0% +denoted by + + + align:start position:0% +denoted by +n the number of vertices in G he's going + + align:start position:0% +n the number of vertices in G he's going + + + align:start position:0% +n the number of vertices in G he's going +to to choose a a random + + align:start position:0% + + + + align:start position:0% + +permutation of the + + align:start position:0% +permutation of the + + + align:start position:0% +permutation of the +nodes now he has kind of the permuted + + align:start position:0% +nodes now he has kind of the permuted + + + align:start position:0% +nodes now he has kind of the permuted +graph in his head so he has pi of G in + + align:start position:0% +graph in his head so he has pi of G in + + + align:start position:0% +graph in his head so he has pi of G in +his + + align:start position:0% +his + + + align:start position:0% +his +head now this it has this P of G has a + + align:start position:0% +head now this it has this P of G has a + + + align:start position:0% +head now this it has this P of G has a +hamiltonian cycle because G has and I + + align:start position:0% +hamiltonian cycle because G has and I + + + align:start position:0% +hamiltonian cycle because G has and I +just renamed the nodes now I'm going to + + align:start position:0% +just renamed the nodes now I'm going to + + + align:start position:0% +just renamed the nodes now I'm going to +I want to give you I want to give you + + align:start position:0% +I want to give you I want to give you + + + align:start position:0% +I want to give you I want to give you +just this hamiltonian cycle so I want to + + align:start position:0% +just this hamiltonian cycle so I want to + + + align:start position:0% +just this hamiltonian cycle so I want to +give you the nodes here that form + + align:start position:0% +give you the nodes here that form + + + align:start position:0% +give you the nodes here that form +Hamilton so I want to give you H I would + + align:start position:0% +Hamilton so I want to give you H I would + + + align:start position:0% +Hamilton so I want to give you H I would +like to give you the nodes that form the + + align:start position:0% +like to give you the nodes that form the + + + align:start position:0% +like to give you the nodes that form the +ham just the hamiltonian cycle but I + + align:start position:0% +ham just the hamiltonian cycle but I + + + align:start position:0% +ham just the hamiltonian cycle but I +can't give you that will reveal + + align:start position:0% +can't give you that will reveal + + + align:start position:0% +can't give you that will reveal +information okay so I don't want to do + + align:start position:0% +information okay so I don't want to do + + + align:start position:0% +information okay so I don't want to do +that instead I'm going to give it to you + + align:start position:0% +that instead I'm going to give it to you + + + align:start position:0% +that instead I'm going to give it to you +kind of in a safe okay hidden this is + + align:start position:0% +kind of in a safe okay hidden this is + + + align:start position:0% +kind of in a safe okay hidden this is +what called in cryptography call this + + align:start position:0% +what called in cryptography call this + + + align:start position:0% +what called in cryptography call this +commitment scheme so I'm going to give + + align:start position:0% +commitment scheme so I'm going to give + + + align:start position:0% +commitment scheme so I'm going to give +you a + + align:start position:0% +you a + + + align:start position:0% +you a +commitment of the cycle C + + align:start position:0% +commitment of the cycle C + + + align:start position:0% +commitment of the cycle C +so think of this I'm for all the + + align:start position:0% +so think of this I'm for all the + + + align:start position:0% +so think of this I'm for all the +possible edges I'm put 0 0 0 0 only in + + align:start position:0% +possible edges I'm put 0 0 0 0 only in + + + align:start position:0% +possible edges I'm put 0 0 0 0 only in +the cycle I'm going to put one that's + + align:start position:0% +the cycle I'm going to put one that's + + + align:start position:0% +the cycle I'm going to put one that's +what I mean here because this so this is + + align:start position:0% +what I mean here because this so this is + + + align:start position:0% +what I mean here because this so this is +like think of it's a + + align:start position:0% + + + + align:start position:0% + +matrix uh of n byn uh + + align:start position:0% +matrix uh of n byn uh + + + align:start position:0% +matrix uh of n byn uh +sorry yeah n + + align:start position:0% +sorry yeah n + + + align:start position:0% +sorry yeah n +byn for any possible Edge for any + + align:start position:0% +byn for any possible Edge for any + + + align:start position:0% +byn for any possible Edge for any +possible node I and J I'm going to put + + align:start position:0% +possible node I and J I'm going to put + + + align:start position:0% +possible node I and J I'm going to put +zero like there's no Edge only if it's + + align:start position:0% +zero like there's no Edge only if it's + + + align:start position:0% +zero like there's no Edge only if it's +in the cycle I'm going to put an edge + + align:start position:0% +in the cycle I'm going to put an edge + + + align:start position:0% +in the cycle I'm going to put an edge +there yeah is on the label of the like + + align:start position:0% +there yeah is on the label of the like + + + align:start position:0% +there yeah is on the label of the like +permuted gra exactly on the permuted + + align:start position:0% +permuted gra exactly on the permuted + + + align:start position:0% +permuted gra exactly on the permuted +graph okay this the reason I permute the + + align:start position:0% +graph okay this the reason I permute the + + + align:start position:0% +graph okay this the reason I permute the +graph is to ensure zero knowledg this + + align:start position:0% +graph is to ensure zero knowledg this + + + align:start position:0% +graph is to ensure zero knowledg this +even though when I send the commitment + + align:start position:0% +even though when I send the commitment + + + align:start position:0% +even though when I send the commitment +really think of it I'm we're going to + + align:start position:0% +really think of it I'm we're going to + + + align:start position:0% +really think of it I'm we're going to +later talk about how to do this + + align:start position:0% +later talk about how to do this + + + align:start position:0% +later talk about how to do this +commitment but for now think of it + + align:start position:0% +commitment but for now think of it + + + align:start position:0% +commitment but for now think of it +there's a safe I'm putting my commitment + + align:start position:0% +there's a safe I'm putting my commitment + + + align:start position:0% +there's a safe I'm putting my commitment +inside the safe I leave the key to + + align:start position:0% +inside the safe I leave the key to + + + align:start position:0% +inside the safe I leave the key to +myself and I give you this box so you + + align:start position:0% +myself and I give you this box so you + + + align:start position:0% +myself and I give you this box so you +learn + + align:start position:0% +learn + + + align:start position:0% +learn +nothing okay so here really you learn + + align:start position:0% +nothing okay so here really you learn + + + align:start position:0% +nothing okay so here really you learn +nothing but now but you but you're not + + align:start position:0% +nothing but now but you but you're not + + + align:start position:0% +nothing but now but you but you're not +convinced either because you just got a + + align:start position:0% +convinced either because you just got a + + + align:start position:0% +convinced either because you just got a +safe what are you going to do with it so + + align:start position:0% +safe what are you going to do with it so + + + align:start position:0% +safe what are you going to do with it so +now here's how I'm going to convince you + + align:start position:0% +now here's how I'm going to convince you + + + align:start position:0% +now here's how I'm going to convince you +that actually this graph is is has a + + align:start position:0% +that actually this graph is is has a + + + align:start position:0% +that actually this graph is is has a +hamiltonian cycle without leaking any + + align:start position:0% +hamiltonian cycle without leaking any + + + align:start position:0% +hamiltonian cycle without leaking any +information so you the verifier you're + + align:start position:0% +information so you the verifier you're + + + align:start position:0% +information so you the verifier you're +going to give me a random bid + + align:start position:0% +going to give me a random bid + + + align:start position:0% +going to give me a random bid +B this is going to be + + align:start position:0% + + + + align:start position:0% + +random random bit now + + align:start position:0% +random random bit now + + + align:start position:0% +random random bit now +if B is + + align:start position:0% +if B is + + + align:start position:0% +if B is +zero I'm just going to open this so if B + + align:start position:0% +zero I'm just going to open this so if B + + + align:start position:0% +zero I'm just going to open this so if B +zero if B is zero open I'm going to open + + align:start position:0% +zero if B is zero open I'm going to open + + + align:start position:0% +zero if B is zero open I'm going to open +the safe and now you can see that what's + + align:start position:0% +the safe and now you can see that what's + + + align:start position:0% +the safe and now you can see that what's +sitting there is a hamiltonian + + align:start position:0% + + + + align:start position:0% + +cycle okay now what did you + + align:start position:0% +cycle okay now what did you + + + align:start position:0% +cycle okay now what did you +learn well because I permuted it's just + + align:start position:0% +learn well because I permuted it's just + + + align:start position:0% +learn well because I permuted it's just +a random cycle actually it has nothing + + align:start position:0% +a random cycle actually it has nothing + + + align:start position:0% +a random cycle actually it has nothing +to do with the graph I can even first + + align:start position:0% +to do with the graph I can even first + + + align:start position:0% +to do with the graph I can even first +just choose a random cycle commit to it + + align:start position:0% +just choose a random cycle commit to it + + + align:start position:0% +just choose a random cycle commit to it +and then kind of post kind of choose + + align:start position:0% +and then kind of post kind of choose + + + align:start position:0% +and then kind of post kind of choose +this permutation to align with this uh + + align:start position:0% +this permutation to align with this uh + + + align:start position:0% +this permutation to align with this uh +with this cycle so really because I G I + + align:start position:0% +with this cycle so really because I G I + + + align:start position:0% +with this cycle so really because I G I +chose you a random permutation it's just + + align:start position:0% +chose you a random permutation it's just + + + align:start position:0% +chose you a random permutation it's just +a random cycle so you didn't learn + + align:start position:0% +a random cycle so you didn't learn + + + align:start position:0% +a random cycle so you didn't learn +anything it's just a random cycle you + + align:start position:0% +anything it's just a random cycle you + + + align:start position:0% +anything it's just a random cycle you +and yourself can put a random cycle in a + + align:start position:0% +and yourself can put a random cycle in a + + + align:start position:0% +and yourself can put a random cycle in a +safe so really no + + align:start position:0% + + + + align:start position:0% + +information what if B equals + + align:start position:0% +information what if B equals + + + align:start position:0% +information what if B equals +1 if B equals 1 + + align:start position:0% +1 if B equals 1 + + + align:start position:0% +1 if B equals 1 +I want to first I want to give you Pi + + align:start position:0% +I want to first I want to give you Pi + + + align:start position:0% +I want to first I want to give you Pi +okay so I give you Pi but now I can't + + align:start position:0% +okay so I give you Pi but now I can't + + + align:start position:0% +okay so I give you Pi but now I can't +open this because now if you know pi and + + align:start position:0% +open this because now if you know pi and + + + align:start position:0% +open this because now if you know pi and +you see the cycle you know where my + + align:start position:0% +you see the cycle you know where my + + + align:start position:0% +you see the cycle you know where my +hamiltonian cycle + + align:start position:0% +hamiltonian cycle + + + align:start position:0% +hamiltonian cycle +is so what I'm going to do I just want + + align:start position:0% +is so what I'm going to do I just want + + + align:start position:0% +is so what I'm going to do I just want +to convince + + align:start position:0% +to convince + + + align:start position:0% +to convince +you + + align:start position:0% +you + + + align:start position:0% +you +that this cycle only + + align:start position:0% +that this cycle only + + + align:start position:0% +that this cycle only +has edges that were in this + + align:start position:0% +has edges that were in this + + + align:start position:0% +has edges that were in this +graph so I'm G to open only the non + + align:start position:0% +graph so I'm G to open only the non + + + align:start position:0% +graph so I'm G to open only the non +edges so instead of opening everything + + align:start position:0% +edges so instead of opening everything + + + align:start position:0% +edges so instead of opening everything +I'm going to + + align:start position:0% +I'm going to + + + align:start position:0% +I'm going to +open non + + align:start position:0% + + + + align:start position:0% + +edges + + align:start position:0% +edges + + + align:start position:0% +edges +in the the permuted + + align:start position:0% +in the the permuted + + + align:start position:0% +in the the permuted +graph so note here we have so I have + + align:start position:0% +graph so note here we have so I have + + + align:start position:0% +graph so note here we have so I have +here like okay so there's a question how + + align:start position:0% +here like okay so there's a question how + + + align:start position:0% +here like okay so there's a question how +do I how do I open so think of + + align:start position:0% +do I how do I open so think of + + + align:start position:0% +do I how do I open so think of +it I I commit to N squared bits okay for + + align:start position:0% +it I I commit to N squared bits okay for + + + align:start position:0% +it I I commit to N squared bits okay for +any possible IG I have a bit saying is + + align:start position:0% +any possible IG I have a bit saying is + + + align:start position:0% +any possible IG I have a bit saying is +it zero or is it one is there an edge or + + align:start position:0% +it zero or is it one is there an edge or + + + align:start position:0% +it zero or is it one is there an edge or +is it not an edge think of it as I'm + + align:start position:0% +is it not an edge think of it as I'm + + + align:start position:0% +is it not an edge think of it as I'm +giving you N squared safes okay like now + + align:start position:0% +giving you N squared safes okay like now + + + align:start position:0% +giving you N squared safes okay like now +if B is zero I open all the safes I open + + align:start position:0% +if B is zero I open all the safes I open + + + align:start position:0% +if B is zero I open all the safes I open +all the safes and you see oh there's + + align:start position:0% +all the safes and you see oh there's + + + align:start position:0% +all the safes and you see oh there's +only there's just a cycle you know + + align:start position:0% +only there's just a cycle you know + + + align:start position:0% +only there's just a cycle you know +there's everything is zero except for + + align:start position:0% +there's everything is zero except for + + + align:start position:0% +there's everything is zero except for +you know i1 and I2 are there's one and + + align:start position:0% +you know i1 and I2 are there's one and + + + align:start position:0% +you know i1 and I2 are there's one and +then I2 I3 that's it everything else is + + align:start position:0% +then I2 I3 that's it everything else is + + + align:start position:0% +then I2 I3 that's it everything else is +zero if you send me a one then I open + + align:start position:0% +zero if you send me a one then I open + + + align:start position:0% +zero if you send me a one then I open +something else I don't open everything + + align:start position:0% +something else I don't open everything + + + align:start position:0% +something else I don't open everything +now opposite what I do is I give you + + align:start position:0% +now opposite what I do is I give you + + + align:start position:0% +now opposite what I do is I give you +pi and for every nonedge in pi I open + + align:start position:0% +pi and for every nonedge in pi I open + + + align:start position:0% +pi and for every nonedge in pi I open +the nonedge safe and I show you see + + align:start position:0% +the nonedge safe and I show you see + + + align:start position:0% +the nonedge safe and I show you see +there + + align:start position:0% +there + + + align:start position:0% +there +zero so all the all the safes I opened + + align:start position:0% +zero so all the all the safes I opened + + + align:start position:0% +zero so all the all the safes I opened +are just going to be + + align:start position:0% +are just going to be + + + align:start position:0% +are just going to be +zero so you really didn't learn anything + + align:start position:0% +zero so you really didn't learn anything + + + align:start position:0% +zero so you really didn't learn anything +I just opened zeros you can simulate + + align:start position:0% +I just opened zeros you can simulate + + + align:start position:0% +I just opened zeros you can simulate +that in your head what do you learn in + + align:start position:0% +that in your head what do you learn in + + + align:start position:0% +that in your head what do you learn in +some sense you know if if you you know + + align:start position:0% +some sense you know if if you you know + + + align:start position:0% +some sense you know if if you you know +that if you accept me oh I'm going to + + align:start position:0% +that if you accept me oh I'm going to + + + align:start position:0% +that if you accept me oh I'm going to +open to do zeros + + align:start position:0% +open to do zeros + + + align:start position:0% +open to do zeros +there and the pi doesn't reveal anything + + align:start position:0% +there and the pi doesn't reveal anything + + + align:start position:0% +there and the pi doesn't reveal anything +it's just random + + align:start position:0% + + + + align:start position:0% + +permutation so note you the verifier + + align:start position:0% +permutation so note you the verifier + + + align:start position:0% +permutation so note you the verifier +didn't learn anything if you open to + + align:start position:0% +didn't learn anything if you open to + + + align:start position:0% +didn't learn anything if you open to +zero if you send me zero I just open + + align:start position:0% +zero if you send me zero I just open + + + align:start position:0% +zero if you send me zero I just open +random cycle has nothing to do with the + + align:start position:0% +random cycle has nothing to do with the + + + align:start position:0% +random cycle has nothing to do with the +graph nothing just random cycle okay + + align:start position:0% +graph nothing just random cycle okay + + + align:start position:0% +graph nothing just random cycle okay +that doesn't get that that's not helpful + + align:start position:0% +that doesn't get that that's not helpful + + + align:start position:0% +that doesn't get that that's not helpful +for you if you open one I gave you + + align:start position:0% +for you if you open one I gave you + + + align:start position:0% +for you if you open one I gave you +completely random permutation + + align:start position:0% +completely random permutation + + + align:start position:0% +completely random permutation +you know p on your own and I open to + + align:start position:0% +you know p on your own and I open to + + + align:start position:0% +you know p on your own and I open to +zeros all the n edes i open to zero you + + align:start position:0% +zeros all the n edes i open to zero you + + + align:start position:0% +zeros all the n edes i open to zero you +learn + + align:start position:0% +learn + + + align:start position:0% +learn +nothing + + align:start position:0% +nothing + + + align:start position:0% +nothing +still you are somewhat + + align:start position:0% +still you are somewhat + + + align:start position:0% +still you are somewhat +convinced that this protocol that that + + align:start position:0% +convinced that this protocol that that + + + align:start position:0% +convinced that this protocol that that +the graph is hamiltonian why are you + + align:start position:0% +the graph is hamiltonian why are you + + + align:start position:0% +the graph is hamiltonian why are you +somewhat convinced that the that there's + + align:start position:0% +somewhat convinced that the that there's + + + align:start position:0% +somewhat convinced that the that there's +a hamiltonian cycle why are you someone + + align:start position:0% +a hamiltonian cycle why are you someone + + + align:start position:0% +a hamiltonian cycle why are you someone +convinced because if there is no + + align:start position:0% +convinced because if there is no + + + align:start position:0% +convinced because if there is no +hamiltonian cycle in G I cannot open to + + align:start position:0% +hamiltonian cycle in G I cannot open to + + + align:start position:0% +hamiltonian cycle in G I cannot open to +both zero and + + align:start position:0% +both zero and + + + align:start position:0% +both zero and +one why why is it the case that I cannot + + align:start position:0% +one why why is it the case that I cannot + + + align:start position:0% +one why why is it the case that I cannot +open let's + + align:start position:0% +open let's + + + align:start position:0% +open let's +see I'm a cheating let's say the graph + + align:start position:0% +see I'm a cheating let's say the graph + + + align:start position:0% +see I'm a cheating let's say the graph +is there's no hamiltonian + + align:start position:0% +is there's no hamiltonian + + + align:start position:0% +is there's no hamiltonian +cycle now I sent you these N squared + + align:start position:0% +cycle now I sent you these N squared + + + align:start position:0% +cycle now I sent you these N squared +safes case one there's indeed only a + + align:start position:0% +safes case one there's indeed only a + + + align:start position:0% +safes case one there's indeed only a +hamiltonian cycle there like indeed when + + align:start position:0% +hamiltonian cycle there like indeed when + + + align:start position:0% +hamiltonian cycle there like indeed when +you open all these end saves what you + + align:start position:0% +you open all these end saves what you + + + align:start position:0% +you open all these end saves what you +see is everything is zero except for + + align:start position:0% +see is everything is zero except for + + + align:start position:0% +see is everything is zero except for +hamiltonian cycle + + align:start position:0% +hamiltonian cycle + + + align:start position:0% +hamiltonian cycle +if that's not the case I cannot open to + + align:start position:0% +if that's not the case I cannot open to + + + align:start position:0% +if that's not the case I cannot open to +zero if I open to zero you catch + + align:start position:0% +zero if I open to zero you catch + + + align:start position:0% +zero if I open to zero you catch +me now suppose I did succeed in opening + + align:start position:0% +me now suppose I did succeed in opening + + + align:start position:0% +me now suppose I did succeed in opening +to zero namely there's just aonian cycle + + align:start position:0% +to zero namely there's just aonian cycle + + + align:start position:0% +to zero namely there's just aonian cycle +there that's + + align:start position:0% +there that's + + + align:start position:0% +there that's +it then I claim there's no way I can + + align:start position:0% +it then I claim there's no way I can + + + align:start position:0% +it then I claim there's no way I can +open to one why if there is a + + align:start position:0% +open to one why if there is a + + + align:start position:0% +open to one why if there is a +hamiltonian cycle there I know the + + align:start position:0% +hamiltonian cycle there I know the + + + align:start position:0% +hamiltonian cycle there I know the +hamiltonian cycle is not on the + + align:start position:0% +hamiltonian cycle is not on the + + + align:start position:0% +hamiltonian cycle is not on the +non-edges because the non-edges are zero + + align:start position:0% +non-edges because the non-edges are zero + + + align:start position:0% +non-edges because the non-edges are zero +if I open on one the non-edges are zero + + align:start position:0% +if I open on one the non-edges are zero + + + align:start position:0% +if I open on one the non-edges are zero +so Theon CLE is on the edges but there + + align:start position:0% +so Theon CLE is on the edges but there + + + align:start position:0% +so Theon CLE is on the edges but there +is noonian cycle it can be on the + + align:start position:0% +is noonian cycle it can be on the + + + align:start position:0% +is noonian cycle it can be on the +edges so either I'm a chover either I + + align:start position:0% +edges so either I'm a chover either I + + + align:start position:0% +edges so either I'm a chover either I +can I I may be able to open to zero I + + align:start position:0% +can I I may be able to open to zero I + + + align:start position:0% +can I I may be able to open to zero I +may be able to open to one but I can't + + align:start position:0% +may be able to open to one but I can't + + + align:start position:0% +may be able to open to one but I can't +open to + + align:start position:0% +open to + + + align:start position:0% +open to +both so with probability half you'll + + align:start position:0% +both so with probability half you'll + + + align:start position:0% +both so with probability half you'll +reject + + align:start position:0% +reject + + + align:start position:0% +reject +me half is not that great but it's + + align:start position:0% +me half is not that great but it's + + + align:start position:0% +me half is not that great but it's +something okay so at least now we know + + align:start position:0% +something okay so at least now we know + + + align:start position:0% +something okay so at least now we know +with probability half I'm going to be + + align:start position:0% +with probability half I'm going to be + + + align:start position:0% +with probability half I'm going to be +rejected + + align:start position:0% + + + + align:start position:0% + +okay you like The + + align:start position:0% +okay you like The + + + align:start position:0% +okay you like The +Detour okay let's go back to the random + + align:start position:0% +Detour okay let's go back to the random + + + align:start position:0% +Detour okay let's go back to the random +or but + + align:start position:0% + + + + align:start position:0% + +yeah I so what no what I commit to is + + align:start position:0% +yeah I so what no what I commit to is + + + align:start position:0% +yeah I so what no what I commit to is +actually I have N squared commitments + + align:start position:0% +actually I have N squared commitments + + + align:start position:0% +actually I have N squared commitments +everything is zero except for a random + + align:start position:0% +everything is zero except for a random + + + align:start position:0% +everything is zero except for a random +cycle I don't I only commit to zeros why + + align:start position:0% +cycle I don't I only commit to zeros why + + + align:start position:0% +cycle I don't I only commit to zeros why +is it important that I only commit to + + align:start position:0% +is it important that I only commit to + + + align:start position:0% +is it important that I only commit to +zeros because + + align:start position:0% +zeros because + + + align:start position:0% +zeros because +when I open okay I want to make sure + + align:start position:0% +when I open okay I want to make sure + + + align:start position:0% +when I open okay I want to make sure +that there's a cycle + + align:start position:0% +that there's a cycle + + + align:start position:0% +that there's a cycle +here but when I open to one I don't want + + align:start position:0% +here but when I open to one I don't want + + + align:start position:0% +here but when I open to one I don't want +to reveal anything and the way I don't + + align:start position:0% +to reveal anything and the way I don't + + + align:start position:0% +to reveal anything and the way I don't +reveal anything is I show that all the + + align:start position:0% +reveal anything is I show that all the + + + align:start position:0% +reveal anything is I show that all the +non edges in pi in pi of G if you open + + align:start position:0% +non edges in pi in pi of G if you open + + + align:start position:0% +non edges in pi in pi of G if you open +them here you'll get a + + align:start position:0% + + + + align:start position:0% + +zero just with the cyle like outline + + align:start position:0% +zero just with the cyle like outline + + + align:start position:0% +zero just with the cyle like outline +exactly exactly what I commit is a + + align:start position:0% +exactly exactly what I commit is a + + + align:start position:0% +exactly exactly what I commit is a +matrix what I commit to is like a matrix + + align:start position:0% +matrix what I commit to is like a matrix + + + align:start position:0% +matrix what I commit to is like a matrix +that only has like a hamiltonian cycle + + align:start position:0% +that only has like a hamiltonian cycle + + + align:start position:0% +that only has like a hamiltonian cycle +and that's it everything else is + + align:start position:0% + + + + align:start position:0% + +zero yeah so in the second case the + + align:start position:0% +zero yeah so in the second case the + + + align:start position:0% +zero yeah so in the second case the +verifi cannot use the permutation to + + align:start position:0% +verifi cannot use the permutation to + + + align:start position:0% +verifi cannot use the permutation to +figure out what edges are not in the hon + + align:start position:0% +figure out what edges are not in the hon + + + align:start position:0% +figure out what edges are not in the hon +ccle for the original right so in the in + + align:start position:0% +ccle for the original right so in the in + + + align:start position:0% +ccle for the original right so in the in +in the b equals one case you're talking + + align:start position:0% +in the b equals one case you're talking + + + align:start position:0% +in the b equals one case you're talking +about yeah in the b equals one case the + + align:start position:0% +about yeah in the b equals one case the + + + align:start position:0% +about yeah in the b equals one case the +verifier what does he learn he learns Pi + + align:start position:0% +verifier what does he learn he learns Pi + + + align:start position:0% +verifier what does he learn he learns Pi +the permutation that's just a random + + align:start position:0% +the permutation that's just a random + + + align:start position:0% +the permutation that's just a random +permutation + + align:start position:0% +permutation + + + align:start position:0% +permutation +and then I'm just telling you I'm + + align:start position:0% +and then I'm just telling you I'm + + + align:start position:0% +and then I'm just telling you I'm +reassuring you that I didn't lie what do + + align:start position:0% +reassuring you that I didn't lie what do + + + align:start position:0% +reassuring you that I didn't lie what do +I mean by reassure you I open everybody + + align:start position:0% +I mean by reassure you I open everybody + + + align:start position:0% +I mean by reassure you I open everybody +you can compute Pi G on your own that's + + align:start position:0% +you can compute Pi G on your own that's + + + align:start position:0% +you can compute Pi G on your own that's +not a secret G's given Pi is given you + + align:start position:0% +not a secret G's given Pi is given you + + + align:start position:0% +not a secret G's given Pi is given you +can Pi G you see all the non edges + + align:start position:0% +can Pi G you see all the non edges + + + align:start position:0% +can Pi G you see all the non edges +that's not a that's not and all the N + + align:start position:0% +that's not a that's not and all the N + + + align:start position:0% +that's not a that's not and all the N +edges I'm going to open only the N edges + + align:start position:0% +edges I'm going to open only the N edges + + + align:start position:0% +edges I'm going to open only the N edges +and show you + + align:start position:0% + + + + align:start position:0% + +zeros okay because the point is if I was + + align:start position:0% +zeros okay because the point is if I was + + + align:start position:0% +zeros okay because the point is if I was +honest what I should do is put on only + + align:start position:0% +honest what I should do is put on only + + + align:start position:0% +honest what I should do is put on only +on edges and not only on edges only on + + align:start position:0% +on edges and not only on edges only on + + + align:start position:0% +on edges and not only on edges only on +hamiltonian and the edes that former + + align:start position:0% +hamiltonian and the edes that former + + + align:start position:0% +hamiltonian and the edes that former +hamiltonian cycle that's what I should + + align:start position:0% +hamiltonian cycle that's what I should + + + align:start position:0% +hamiltonian cycle that's what I should +do if I'm honest and what I show you I + + align:start position:0% +do if I'm honest and what I show you I + + + align:start position:0% +do if I'm honest and what I show you I +don't show you that because that will + + align:start position:0% +don't show you that because that will + + + align:start position:0% +don't show you that because that will +give information but at least what I + + align:start position:0% +give information but at least what I + + + align:start position:0% +give information but at least what I +show you then all the non-edges here I + + align:start position:0% +show you then all the non-edges here I + + + align:start position:0% +show you then all the non-edges here I +committed to + + align:start position:0% +committed to + + + align:start position:0% +committed to +zero and that gives you no + + align:start position:0% +zero and that gives you no + + + align:start position:0% +zero and that gives you no +information but if indeed I the + + align:start position:0% +information but if indeed I the + + + align:start position:0% +information but if indeed I the +non-edges are zero and there's + + align:start position:0% +non-edges are zero and there's + + + align:start position:0% +non-edges are zero and there's +hamiltonian cycle then it means Honan + + align:start position:0% +hamiltonian cycle then it means Honan + + + align:start position:0% +hamiltonian cycle then it means Honan +must must be edges and then it means + + align:start position:0% +must must be edges and then it means + + + align:start position:0% +must must be edges and then it means +that P G has a hon cycle and that can't + + align:start position:0% +that P G has a hon cycle and that can't + + + align:start position:0% +that P G has a hon cycle and that can't +be if G doesn't have a hilon cycle 5G + + align:start position:0% +be if G doesn't have a hilon cycle 5G + + + align:start position:0% +be if G doesn't have a hilon cycle 5G +doesn't have a honi cycle and that's why + + align:start position:0% +doesn't have a honi cycle and that's why + + + align:start position:0% +doesn't have a honi cycle and that's why +I can't succeed in convincing + + align:start position:0% +I can't succeed in convincing + + + align:start position:0% +I can't succeed in convincing +you in answering both + + align:start position:0% + + + + align:start position:0% + +questions yeah is there a formal way to + + align:start position:0% +questions yeah is there a formal way to + + + align:start position:0% +questions yeah is there a formal way to +say what it means to be zero knowledge + + align:start position:0% + + + + align:start position:0% + +like good good good good good so the + + align:start position:0% +like good good good good good so the + + + align:start position:0% +like good good good good good so the +question yeah actually I plan not to go + + align:start position:0% +question yeah actually I plan not to go + + + align:start position:0% +question yeah actually I plan not to go +into the the but it's so beautiful so I + + align:start position:0% +into the the but it's so beautiful so I + + + align:start position:0% +into the the but it's so beautiful so I +will + + align:start position:0% +will + + + align:start position:0% +will +a yeah so the question was uh what is + + align:start position:0% +a yeah so the question was uh what is + + + align:start position:0% +a yeah so the question was uh what is +the definition actually of zero + + align:start position:0% +the definition actually of zero + + + align:start position:0% +the definition actually of zero +knowledge and the definition of zero + + align:start position:0% +knowledge and the definition of zero + + + align:start position:0% +knowledge and the definition of zero +knowledge + + align:start position:0% +knowledge + + + align:start position:0% +knowledge +says that what does it mean you don't + + align:start position:0% +says that what does it mean you don't + + + align:start position:0% +says that what does it mean you don't +learn anything so the definition says + + align:start position:0% +learn anything so the definition says + + + align:start position:0% +learn anything so the definition says +that so this is the definition of zero + + align:start position:0% + + + + align:start position:0% + +knowledge what it says + + align:start position:0% +knowledge what it says + + + align:start position:0% +knowledge what it says +is the verifier actually it's it says + + align:start position:0% +is the verifier actually it's it says + + + align:start position:0% +is the verifier actually it's it says +it's stronger it says for every verifier + + align:start position:0% +it's stronger it says for every verifier + + + align:start position:0% +it's stronger it says for every verifier +not just the honest verifier even + + align:start position:0% +not just the honest verifier even + + + align:start position:0% +not just the honest verifier even +malicious ver there's you can talk about + + align:start position:0% +malicious ver there's you can talk about + + + align:start position:0% +malicious ver there's you can talk about +honest verifier you an object the honest + + align:start position:0% +honest verifier you an object the honest + + + align:start position:0% +honest verifier you an object the honest +verifier who just does what it should do + + align:start position:0% +verifier who just does what it should do + + + align:start position:0% +verifier who just does what it should do +and just listens doesn't learn anything + + align:start position:0% +and just listens doesn't learn anything + + + align:start position:0% +and just listens doesn't learn anything +but actually there's a stronger notion + + align:start position:0% +but actually there's a stronger notion + + + align:start position:0% +but actually there's a stronger notion +of malicious so I say even for malicious + + align:start position:0% + + + + align:start position:0% + +verifier you want to say what he learned + + align:start position:0% +verifier you want to say what he learned + + + align:start position:0% +verifier you want to say what he learned +he could have simulated on his + + align:start position:0% +he could have simulated on his + + + align:start position:0% +he could have simulated on his +own so the definition says for every uh + + align:start position:0% +own so the definition says for every uh + + + align:start position:0% +own so the definition says for every uh +so you okay for every verifier if you + + align:start position:0% +so you okay for every verifier if you + + + align:start position:0% +so you okay for every verifier if you +look the + + align:start position:0% + + + + align:start position:0% + +transcript of and and for every X and + + align:start position:0% +transcript of and and for every X and + + + align:start position:0% +transcript of and and for every X and +L for every X if you look at the + + align:start position:0% +L for every X if you look at the + + + align:start position:0% +L for every X if you look at the +transcript between the honest prover and + + align:start position:0% +transcript between the honest prover and + + + align:start position:0% +transcript between the honest prover and +the + + align:start position:0% +the + + + align:start position:0% +the +verifier the prover has a witness but + + align:start position:0% +verifier the prover has a witness but + + + align:start position:0% +verifier the prover has a witness but +the verifier + + align:start position:0% +the verifier + + + align:start position:0% +the verifier +doesn't what he learned from this + + align:start position:0% +doesn't what he learned from this + + + align:start position:0% +doesn't what he learned from this +transcript or what the verify maybe + + align:start position:0% +transcript or what the verify maybe + + + align:start position:0% +transcript or what the verify maybe +sorry let me write it differently let me + + align:start position:0% +sorry let me write it differently let me + + + align:start position:0% +sorry let me write it differently let me +say The View + + align:start position:0% + + + + align:start position:0% + +of V Star while interacting with + + align:start position:0% +of V Star while interacting with + + + align:start position:0% +of V Star while interacting with +P an input + + align:start position:0% +P an input + + + align:start position:0% +P an input +X so whatever varar + + align:start position:0% +X so whatever varar + + + align:start position:0% +X so whatever varar +learned he could have simulated on his + + align:start position:0% + + + + align:start position:0% + +own so it says there + + align:start position:0% +own so it says there + + + align:start position:0% +own so it says there +exists a + + align:start position:0% +exists a + + + align:start position:0% +exists a +simulator and this is efficient and + + align:start position:0% +simulator and this is efficient and + + + align:start position:0% +simulator and this is efficient and +efficient + + align:start position:0% + + + + align:start position:0% + +simulator such + + align:start position:0% + + + + align:start position:0% + +that the simulator efficiently can + + align:start position:0% +that the simulator efficiently can + + + align:start position:0% +that the simulator efficiently can +generate this transcript on his + + align:start position:0% +generate this transcript on his + + + align:start position:0% +generate this transcript on his +own if he has v he needs varar because + + align:start position:0% +own if he has v he needs varar because + + + align:start position:0% +own if he has v he needs varar because +of course varar depends what he sends + + align:start position:0% +of course varar depends what he sends + + + align:start position:0% +of course varar depends what he sends +and so on but he could generate it on + + align:start position:0% +and so on but he could generate it on + + + align:start position:0% +and so on but he could generate it on +his + + align:start position:0% +his + + + align:start position:0% +his +own + + align:start position:0% +own + + + align:start position:0% +own +yeah on + + align:start position:0% +yeah on + + + align:start position:0% +yeah on +than is it the same SIM for every oh my + + align:start position:0% +than is it the same SIM for every oh my + + + align:start position:0% +than is it the same SIM for every oh my +God there's so many okay there's so so + + align:start position:0% +God there's so many okay there's so so + + + align:start position:0% +God there's so many okay there's so so +many Notions of zero knowledge so for + + align:start position:0% +many Notions of zero knowledge so for + + + align:start position:0% +many Notions of zero knowledge so for +example first of all it I'll answer your + + align:start position:0% +example first of all it I'll answer your + + + align:start position:0% +example first of all it I'll answer your +question the question was is the + + align:start position:0% +question the question was is the + + + align:start position:0% +question the question was is the +simulator only gets V Star as Oracle AIS + + align:start position:0% +simulator only gets V Star as Oracle AIS + + + align:start position:0% +simulator only gets V Star as Oracle AIS +does it get as an input is it Universal + + align:start position:0% +does it get as an input is it Universal + + + align:start position:0% +does it get as an input is it Universal +is it for there exist for every V is it + + align:start position:0% +is it for there exist for every V is it + + + align:start position:0% +is it for there exist for every V is it +for every V there's a simulator moreover + + align:start position:0% +for every V there's a simulator moreover + + + align:start position:0% +for every V there's a simulator moreover +let me continue is V all powerful is V + + align:start position:0% +let me continue is V all powerful is V + + + align:start position:0% +let me continue is V all powerful is V +supposed to be PPT or poly siiz + + align:start position:0% + + + + align:start position:0% + +and the answers there's many definitions + + align:start position:0% + + + + align:start position:0% + +but yeah so + + align:start position:0% + + + + align:start position:0% + +um originally all the protocols we had + + align:start position:0% +um originally all the protocols we had + + + align:start position:0% +um originally all the protocols we had +used the verifiers of + + align:start position:0% +used the verifiers of + + + align:start position:0% +used the verifiers of +blackbox uh however in 2001 I think was + + align:start position:0% +blackbox uh however in 2001 I think was + + + align:start position:0% +blackbox uh however in 2001 I think was +it h BOS Barak was the first kind of + + align:start position:0% +it h BOS Barak was the first kind of + + + align:start position:0% +it h BOS Barak was the first kind of +construct non blackbox Z knowledge where + + align:start position:0% +construct non blackbox Z knowledge where + + + align:start position:0% +construct non blackbox Z knowledge where +the simulator used verifire as a non + + align:start position:0% +the simulator used verifire as a non + + + align:start position:0% +the simulator used verifire as a non +blackbox and it was a really + + align:start position:0% +blackbox and it was a really + + + align:start position:0% +blackbox and it was a really +breakthrough result because what he + + align:start position:0% +breakthrough result because what he + + + align:start position:0% +breakthrough result because what he +managed to to get is a new Zer knowledge + + align:start position:0% +managed to to get is a new Zer knowledge + + + align:start position:0% +managed to to get is a new Zer knowledge +proof that we didn't know of before it + + align:start position:0% +proof that we didn't know of before it + + + align:start position:0% +proof that we didn't know of before it +was kind of constant round now you you + + align:start position:0% +was kind of constant round now you you + + + align:start position:0% +was kind of constant round now you you +can say wait this is also constant round + + align:start position:0% +can say wait this is also constant round + + + align:start position:0% +can say wait this is also constant round +what do you mean we didn't know before + + align:start position:0% +what do you mean we didn't know before + + + align:start position:0% +what do you mean we didn't know before +but this is only sound as + + align:start position:0% + + + + align:start position:0% + +half turns out if you want NE sound this + + align:start position:0% +half turns out if you want NE sound this + + + align:start position:0% +half turns out if you want NE sound this +you need to repeat this protocol + + align:start position:0% +you need to repeat this protocol + + + align:start position:0% +you need to repeat this protocol +sequentially you can if you repeat it in + + align:start position:0% +sequentially you can if you repeat it in + + + align:start position:0% +sequentially you can if you repeat it in +parallel + + align:start position:0% +parallel + + + align:start position:0% +parallel +it's it's not necessarily zero knowledge + + align:start position:0% +it's it's not necessarily zero knowledge + + + align:start position:0% +it's it's not necessarily zero knowledge +actually yeah this one actually is not + + align:start position:0% +actually yeah this one actually is not + + + align:start position:0% +actually yeah this one actually is not +zero knowledge if you're you're + + align:start position:0% +zero knowledge if you're you're + + + align:start position:0% +zero knowledge if you're you're +repeating in parallel we we'll talk + + align:start position:0% +repeating in parallel we we'll talk + + + align:start position:0% +repeating in parallel we we'll talk +about that and so using non blackbox + + align:start position:0% +about that and so using non blackbox + + + align:start position:0% +about that and so using non blackbox +technique he managed to show the first + + align:start position:0% +technique he managed to show the first + + + align:start position:0% +technique he managed to show the first +kind of Conant round zero knowledge + + align:start position:0% +kind of Conant round zero knowledge + + + align:start position:0% +kind of Conant round zero knowledge +public coin zero knowledge proof so + + align:start position:0% +public coin zero knowledge proof so + + + align:start position:0% +public coin zero knowledge proof so +there's there's many many variants okay + + align:start position:0% +there's there's many many variants okay + + + align:start position:0% +there's there's many many variants okay +is is the + + align:start position:0% +is is the + + + align:start position:0% +is is the +a the the + + align:start position:0% + + + + align:start position:0% + +point okay but this is kind of a common + + align:start position:0% +point okay but this is kind of a common + + + align:start position:0% +point okay but this is kind of a common +variant to think + + align:start position:0% +variant to think + + + align:start position:0% +variant to think +about and also um so this is kind of + + align:start position:0% +about and also um so this is kind of + + + align:start position:0% +about and also um so this is kind of +poly size or or V can have auxiliary + + align:start position:0% +poly size or or V can have auxiliary + + + align:start position:0% +poly size or or V can have auxiliary +input so for every X and A or V Star is + + align:start position:0% +input so for every X and A or V Star is + + + align:start position:0% +input so for every X and A or V Star is +poly size so we can have like auxilary + + align:start position:0% +poly size so we can have like auxilary + + + align:start position:0% +poly size so we can have like auxilary +information about X even if he has ail + + align:start position:0% +information about X even if he has ail + + + align:start position:0% +information about X even if he has ail +information about X still so V Star is + + align:start position:0% +information about X still so V Star is + + + align:start position:0% +information about X still so V Star is +kind of has may have ex information + + align:start position:0% +kind of has may have ex information + + + align:start position:0% +kind of has may have ex information +about + + align:start position:0% +about + + + align:start position:0% +about +X still the two are + + align:start position:0% +X still the two are + + + align:start position:0% +X still the two are +indistinguishable + + align:start position:0% +indistinguishable + + + align:start position:0% +indistinguishable +yeah what if + + align:start position:0% +yeah what if + + + align:start position:0% +yeah what if +the follow with + + align:start position:0% +the follow with + + + align:start position:0% +the follow with +commitment where he create that matrices + + align:start position:0% +commitment where he create that matrices + + + align:start position:0% +commitment where he create that matrices +that cycle in that matri Comm that wait + + align:start position:0% +that cycle in that matri Comm that wait + + + align:start position:0% +that cycle in that matri Comm that wait +again what if the commit approver + + align:start position:0% +again what if the commit approver + + + align:start position:0% +again what if the commit approver +commits to a cycle or no he commits to a + + align:start position:0% +commits to a cycle or no he commits to a + + + align:start position:0% +commits to a cycle or no he commits to a +cycle but the cycle is not necessarily + + align:start position:0% + + + + align:start position:0% + +it has nothing to do with G just commits + + align:start position:0% +it has nothing to do with G just commits + + + align:start position:0% +it has nothing to do with G just commits +to any cycle he to CC that then able + + align:start position:0% +to any cycle he to CC that then able + + + align:start position:0% +to any cycle he to CC that then able +to it's zero right yeah he'll be able to + + align:start position:0% +to it's zero right yeah he'll be able to + + + align:start position:0% +to it's zero right yeah he'll be able to +exactly he'll be able to answer zero but + + align:start position:0% +exactly he'll be able to answer zero but + + + align:start position:0% +exactly he'll be able to answer zero but +he won't be able to answer + + align:start position:0% +he won't be able to answer + + + align:start position:0% +he won't be able to answer +one because that cycle must touch an + + align:start position:0% +one because that cycle must touch an + + + align:start position:0% +one because that cycle must touch an +edge + + align:start position:0% +edge + + + align:start position:0% +edge +because sorry that cycle must touch a + + align:start position:0% +because sorry that cycle must touch a + + + align:start position:0% +because sorry that cycle must touch a +non-edge because if it only touched + + align:start position:0% +non-edge because if it only touched + + + align:start position:0% +non-edge because if it only touched +edges + + align:start position:0% +edges + + + align:start position:0% +edges +there is no cycle so that cycle you give + + align:start position:0% +there is no cycle so that cycle you give + + + align:start position:0% +there is no cycle so that cycle you give +here Pi now the prover can the cheating + + align:start position:0% +here Pi now the prover can the cheating + + + align:start position:0% +here Pi now the prover can the cheating +prover can give whatever Pi he wants but + + align:start position:0% +prover can give whatever Pi he wants but + + + align:start position:0% +prover can give whatever Pi he wants but +the point is that the graph the permuted + + align:start position:0% +the point is that the graph the permuted + + + align:start position:0% +the point is that the graph the permuted +graph doesn't have a hamiltonian cycle + + align:start position:0% +graph doesn't have a hamiltonian cycle + + + align:start position:0% +graph doesn't have a hamiltonian cycle +because if G doesn't have a hamiltonian + + align:start position:0% +because if G doesn't have a hamiltonian + + + align:start position:0% +because if G doesn't have a hamiltonian +cyle the permuted G also doesn't have a + + align:start position:0% +cyle the permuted G also doesn't have a + + + align:start position:0% +cyle the permuted G also doesn't have a +hamiltonian cycle so this graph doesn't + + align:start position:0% +hamiltonian cycle so this graph doesn't + + + align:start position:0% +hamiltonian cycle so this graph doesn't +have a hamiltonian cycle and that means + + align:start position:0% +have a hamiltonian cycle and that means + + + align:start position:0% +have a hamiltonian cycle and that means +that the cycle that's here I don't care + + align:start position:0% +that the cycle that's here I don't care + + + align:start position:0% +that the cycle that's here I don't care +how you generate whatever the cycle was + + align:start position:0% +how you generate whatever the cycle was + + + align:start position:0% +how you generate whatever the cycle was +it must touch such a non + + align:start position:0% +it must touch such a non + + + align:start position:0% +it must touch such a non +Edge so so the hamiltonan CLE says you + + align:start position:0% +Edge so so the hamiltonan CLE says you + + + align:start position:0% +Edge so so the hamiltonan CLE says you +know there's an edge between i1 I2 + + align:start position:0% +know there's an edge between i1 I2 + + + align:start position:0% +know there's an edge between i1 I2 +there's an edge between I2 I3 there one + + align:start position:0% +there's an edge between I2 I3 there one + + + align:start position:0% +there's an edge between I2 I3 there one +of them cannot be edge here it can't be + + align:start position:0% +of them cannot be edge here it can't be + + + align:start position:0% +of them cannot be edge here it can't be +that all of them are edges here because + + align:start position:0% +that all of them are edges here because + + + align:start position:0% +that all of them are edges here because +they're so because it doesn't have an + + align:start position:0% +they're so because it doesn't have an + + + align:start position:0% +they're so because it doesn't have an +malonian cycle so one of them cannot be + + align:start position:0% +malonian cycle so one of them cannot be + + + align:start position:0% +malonian cycle so one of them cannot be +an edge here and now what the what the + + align:start position:0% +an edge here and now what the what the + + + align:start position:0% +an edge here and now what the what the +verifier is asking from the prover he + + align:start position:0% +verifier is asking from the prover he + + + align:start position:0% +verifier is asking from the prover he +looks at all the I i1 and I all the I + + align:start position:0% +looks at all the I i1 and I all the I + + + align:start position:0% +looks at all the I i1 and I all the I +and J that do not have an edge and he + + align:start position:0% +and J that do not have an edge and he + + + align:start position:0% +and J that do not have an edge and he +open that edge I want to see that it's + + align:start position:0% +open that edge I want to see that it's + + + align:start position:0% +open that edge I want to see that it's +zero I want I want you I want to see + + align:start position:0% +zero I want I want you I want to see + + + align:start position:0% +zero I want I want you I want to see +that I gave you n squar safes so for + + align:start position:0% +that I gave you n squar safes so for + + + align:start position:0% +that I gave you n squar safes so for +every inj there's a safe and it should + + align:start position:0% +every inj there's a safe and it should + + + align:start position:0% +every inj there's a safe and it should +be one if there's an edge and zero other + + align:start position:0% +be one if there's an edge and zero other + + + align:start position:0% +be one if there's an edge and zero other +I mean if there's an edge in the + + align:start position:0% +I mean if there's an edge in the + + + align:start position:0% +I mean if there's an edge in the +hamiltonian cycle and zero otherwise now + + align:start position:0% +hamiltonian cycle and zero otherwise now + + + align:start position:0% +hamiltonian cycle and zero otherwise now +with the with the verifier is asking the + + align:start position:0% +with the with the verifier is asking the + + + align:start position:0% +with the with the verifier is asking the +prover for every J here that does not + + align:start position:0% +prover for every J here that does not + + + align:start position:0% +prover for every J here that does not +have an edge I want you to open the safe + + align:start position:0% +have an edge I want you to open the safe + + + align:start position:0% +have an edge I want you to open the safe +corresponding to that edge and I want to + + align:start position:0% +corresponding to that edge and I want to + + + align:start position:0% +corresponding to that edge and I want to +see a zero there if there's a one there + + align:start position:0% +see a zero there if there's a one there + + + align:start position:0% +see a zero there if there's a one there +I'm not happy I'm going to reject you + + align:start position:0% +I'm not happy I'm going to reject you + + + align:start position:0% +I'm not happy I'm going to reject you +because this there should be on only on + + align:start position:0% +because this there should be on only on + + + align:start position:0% +because this there should be on only on +the hamiltonian cycle and these are only + + align:start position:0% +the hamiltonian cycle and these are only + + + align:start position:0% +the hamiltonian cycle and these are only +places that have an edge on your + + align:start position:0% +places that have an edge on your + + + align:start position:0% +places that have an edge on your +graph but the problem + + align:start position:0% +graph but the problem + + + align:start position:0% +graph but the problem +is on one of these I that don't have an + + align:start position:0% +is on one of these I that don't have an + + + align:start position:0% +is on one of these I that don't have an +edge you'll see an edge because the + + align:start position:0% +edge you'll see an edge because the + + + align:start position:0% +edge you'll see an edge because the +aonian tyo is not all on edges and then + + align:start position:0% +aonian tyo is not all on edges and then + + + align:start position:0% +aonian tyo is not all on edges and then +I'm going to catch + + align:start position:0% +I'm going to catch + + + align:start position:0% +I'm going to catch +you yeah + + align:start position:0% + + + + align:start position:0% + +great any more questions + + align:start position:0% + + + + align:start position:0% + +yeah slightly stronger that requires the + + align:start position:0% +yeah slightly stronger that requires the + + + align:start position:0% +yeah slightly stronger that requires the +pro to actually + + align:start position:0% +pro to actually + + + align:start position:0% +pro to actually +know the hamiltonian cycle right so here + + align:start position:0% +know the hamiltonian cycle right so here + + + align:start position:0% +know the hamiltonian cycle right so here +the proof like with the second part say + + align:start position:0% +the proof like with the second part say + + + align:start position:0% +the proof like with the second part say +that only guarante that if G is not + + align:start position:0% +that only guarante that if G is not + + + align:start position:0% +that only guarante that if G is not +doesn't have a + + align:start position:0% +doesn't have a + + + align:start position:0% +doesn't have a +hon proof + + align:start position:0% +hon proof + + + align:start position:0% +hon proof +the cannot but do necess like Converse + + align:start position:0% +the cannot but do necess like Converse + + + align:start position:0% +the cannot but do necess like Converse +like + + align:start position:0% +like + + + align:start position:0% +like +is it possible for G to not know cyle + + align:start position:0% +is it possible for G to not know cyle + + + align:start position:0% +is it possible for G to not know cyle +but still ver good G good good good + + align:start position:0% +but still ver good G good good good + + + align:start position:0% +but still ver good G good good good +great question great question so the + + align:start position:0% +great question great question so the + + + align:start position:0% +great question great question so the +question was or let me just answer the + + align:start position:0% +question was or let me just answer the + + + align:start position:0% +question was or let me just answer the +question is the qu the question was wait + + align:start position:0% +question is the qu the question was wait + + + align:start position:0% +question is the qu the question was wait +we just proved your soundness that if x + + align:start position:0% +we just proved your soundness that if x + + + align:start position:0% +we just proved your soundness that if x +is an non the language on one of the + + align:start position:0% +is an non the language on one of the + + + align:start position:0% +is an non the language on one of the +answers you'll fail but actually doesn't + + align:start position:0% +answers you'll fail but actually doesn't + + + align:start position:0% +answers you'll fail but actually doesn't +this protocol give you something + + align:start position:0% +this protocol give you something + + + align:start position:0% +this protocol give you something +stronger was the question and the answer + + align:start position:0% +stronger was the question and the answer + + + align:start position:0% +stronger was the question and the answer +is yes so what what do we mean by some + + align:start position:0% +is yes so what what do we mean by some + + + align:start position:0% +is yes so what what do we mean by some +something stronger let's say G is does + + align:start position:0% +something stronger let's say G is does + + + align:start position:0% +something stronger let's say G is does +have a hamiltonian + + align:start position:0% +have a hamiltonian + + + align:start position:0% +have a hamiltonian +cycle doesn't this protocol tell us not + + align:start position:0% +cycle doesn't this protocol tell us not + + + align:start position:0% +cycle doesn't this protocol tell us not +only that g has a hamiltonian cycle if + + align:start position:0% +only that g has a hamiltonian cycle if + + + align:start position:0% +only that g has a hamiltonian cycle if +you succeed let's say you succeed + + align:start position:0% +you succeed let's say you succeed + + + align:start position:0% +you succeed let's say you succeed +probability one or you know with h more + + align:start position:0% +probability one or you know with h more + + + align:start position:0% +probability one or you know with h more +more than + + align:start position:0% +more than + + + align:start position:0% +more than +half this protocol tells us not only + + align:start position:0% +half this protocol tells us not only + + + align:start position:0% +half this protocol tells us not only +that g has a hamiltonian cycle it means + + align:start position:0% +that g has a hamiltonian cycle it means + + + align:start position:0% +that g has a hamiltonian cycle it means +that P must know the + + align:start position:0% +that P must know the + + + align:start position:0% +that P must know the +cycle you can actually find you can + + align:start position:0% +cycle you can actually find you can + + + align:start position:0% +cycle you can actually find you can +extract the cycle from from from p and + + align:start position:0% +extract the cycle from from from p and + + + align:start position:0% +extract the cycle from from from p and +the answer is yes yes you can you can + + align:start position:0% +the answer is yes yes you can you can + + + align:start position:0% +the answer is yes yes you can you can +actually this is what's called proof of + + align:start position:0% +actually this is what's called proof of + + + align:start position:0% +actually this is what's called proof of +knowledge it means that P knows now I + + align:start position:0% +knowledge it means that P knows now I + + + align:start position:0% +knowledge it means that P knows now I +can say what does it mean that P knows + + align:start position:0% +can say what does it mean that P knows + + + align:start position:0% +can say what does it mean that P knows +what do we this is this is a theory + + align:start position:0% +what do we this is this is a theory + + + align:start position:0% +what do we this is this is a theory +class mathematics what does no mean you + + align:start position:0% +class mathematics what does no mean you + + + align:start position:0% +class mathematics what does no mean you +know so what what what we mean by P NOS + + align:start position:0% +know so what what what we mean by P NOS + + + align:start position:0% +know so what what what we mean by P NOS +what we mean is that we can actually + + align:start position:0% +what we mean is that we can actually + + + align:start position:0% +what we mean is that we can actually +efficiently extract the cycle from p and + + align:start position:0% +efficiently extract the cycle from p and + + + align:start position:0% +efficiently extract the cycle from p and +how do we extract the cycle it's + + align:start position:0% +how do we extract the cycle it's + + + align:start position:0% +how do we extract the cycle it's +actually very + + align:start position:0% +actually very + + + align:start position:0% +actually very +easy we ask him he committed to + + align:start position:0% +easy we ask him he committed to + + + align:start position:0% +easy we ask him he committed to +something he knows how to open both + + align:start position:0% +something he knows how to open both + + + align:start position:0% +something he knows how to open both +that's assumption so first we'll ask him + + align:start position:0% +that's assumption so first we'll ask him + + + align:start position:0% +that's assumption so first we'll ask him +okay open only the + + align:start position:0% + + + + align:start position:0% + +cycle and + + align:start position:0% +cycle and + + + align:start position:0% +cycle and +then give me the + + align:start position:0% +then give me the + + + align:start position:0% +then give me the +pi once I know the pi and the cycle I + + align:start position:0% +pi once I know the pi and the cycle I + + + align:start position:0% +pi once I know the pi and the cycle I +can I can undo I can I know what py gen + + align:start position:0% +can I can undo I can I know what py gen + + + align:start position:0% +can I can undo I can I know what py gen +I can see I can actually find the aonian + + align:start position:0% +I can see I can actually find the aonian + + + align:start position:0% +I can see I can actually find the aonian +cycle so it's it's more than just a + + align:start position:0% +cycle so it's it's more than just a + + + align:start position:0% +cycle so it's it's more than just a +soundness it's a proof of knowledge he + + align:start position:0% +soundness it's a proof of knowledge he + + + align:start position:0% +soundness it's a proof of knowledge he +must no I can actually use him to kind + + align:start position:0% +must no I can actually use him to kind + + + align:start position:0% +must no I can actually use him to kind +of extract the the antonian cycle from + + align:start position:0% + + + + align:start position:0% + +him any any other + + align:start position:0% +him any any other + + + align:start position:0% +him any any other +questions okay so let's take a five + + align:start position:0% +questions okay so let's take a five + + + align:start position:0% +questions okay so let's take a five +minute break and then after the break + + align:start position:0% +minute break and then after the break + + + align:start position:0% +minute break and then after the break +I'm going to show you why this protocol + + align:start position:0% +I'm going to show you why this protocol + + + align:start position:0% +I'm going to show you why this protocol +is not secure in the roral model but + + align:start position:0% +is not secure in the roral model but + + + align:start position:0% +is not secure in the roral model but +we'll fix it don't worry okay I'll take + + align:start position:0% +we'll fix it don't worry okay I'll take + + + align:start position:0% +we'll fix it don't worry okay I'll take +a break \ No newline at end of file diff --git a/yIjTCMlIgpU.txt b/yIjTCMlIgpU.txt new file mode 100644 index 0000000000000000000000000000000000000000..a039a7151b1fa95929429485076091fc66cfafa5 --- /dev/null +++ b/yIjTCMlIgpU.txt @@ -0,0 +1,2774 @@ +PROFESSOR: OK, +welcome back to 6849. + +So last lecture, +lecture three, we + +were talking about +local foldability + +and some complicated flat +folding, like a flapping bird + +here. + +We were looking at a +single vertex and locally + +around that vertex +what properties + +it would have to have. + +And we saw Kawasaki's theorem +which characterized the angles. + +And without a mountain +valley assignment + +Kawasaki was all you needed. + +The alternating sum +of angles should be 0. + +And given a mountain +valley pattern, locally + +we characterize things +as a sequence, anything + +you can do by a +sequence of crimps. + +So sort of a similar +version to lecture + +two, which was about +1D flat foldability. + +There we needed +crimps and end folds. + +Here we needed just +crimps, which is easier. + +So I'm going to +jump into questions. + +And in particular, this +is an opportunity for me + +to talk about the main +thing that I skipped + +last class, class two, +because it relates again + +to this lecture, which is how +do we do this algorithmically? + +So it's one thing +to say, oh, just + +do crimps and end folds +till you can't anymore, + +and then when you run out of +stuff to do, if you're done, + +you're done, otherwise +it's not flat foldable. + +That's true. + +But the obvious way to +implement that algorithm + +is to sweep over +the crease pattern, + +look for any crimps +or end folds. + +If you find one, do it, and +then repeat and keep sweeping. + +And that would take +quadratic time, + +because in the worst +case every scan + +you have to look through +the whole pattern + +and at the very end you +find what you need to do. + +So after about n +operations-- n is + +the number of creases +in your pattern-- + +you find what you need to +do, you do the operation, + +and then you repeat. + +So n plus n plus n, n +times, is n squared. + +But you can do +better and it's been + +alluded to in the lectures, +but it wasn't covered. + +And so I wanted to cover +it, because there's actually + +a really simple way to do it. + +There's one version +in the textbook, + +but there is a simpler way. + +So I want to talk about that. + +This is a new way we +just invented last week? + +This week? + +I forget. + +So I'm going to first talk +about it in the 1D scenario, + +but it's pretty much +the same for both. + +1D's a little bit easier +to think about, though. + +So 1D mountain valley +pattern something like this. + +So I'm going to follow +the same approach, which + +is sweep left to right +until I find either an end + +fold or a crimp that I can do. + +So in this case, maybe this +would be the first thing + +that I find sweeping +left to right. + +That's a crimpable pair-- +or crimpable segment, + +I'm going to call it-- is just +one that is locally smallest. + +It's less than or equal to +its two neighbors in length, + +and it has two different +assignments, M/V or V/M. + +So that's a crimpable +pair, because it's + +shorter than those two guys. + +So that's the basic +algorithm, but what + +I do after that is going to +be a little bit different. + +So I want to search left to +right for a segment that's + +either crimpable +or end foldable. + +And there's two situations. + +If I don't find any operations +to do, then we stop. + +And if there are +any creases left + +we know that the +resulting thing is not + +flat foldable from what +we proved in lecture two. + +If there's no crimp or end +fold, you're not flat foldable. + +But if you do find +something, then do the fold. + +This is so far pretty obvious. + +I'm going to draw the picture +for a crimp situation. + +So in the crimp +situation-- these + +are the previous +and next creases-- + +we have these +lengths x, y, and z. + +We know that y is less than +or equal to z and is less than + +or equal to x. + +And after we do the +crimp, it looks like this. + +So we have x, y, and +z here, but we're + +then going to fuse +this material together, + +because these creases +are done with. + +We don't really care about them. + +The new length that we +get is x minus y plus z. + +OK. + +So that's what I +mean by do the fold. + +And we'll also call this +sort of merging the segments, + +meaning replace-- so normally +we have a sequence of lengths-- + +replace x, y, z with +x minus y plus z, + +remove these two creases +which were, say, M and V. + +Now we want to continue. + +And the realization +is that we don't + +have to start over our +search in searching + +left to right for +a crimpable thing. + +If we went all the way +through the pattern + +and then finally found +a crimp at the end, + +should we start way back here? + +No. + +There's no point. + +You might as well start +basically where you just were. + +Not quite. + +You have to go back one step. + +So the next step in this +algorithm is go back one step, + +and then continue the search. + +Back means left. + +And the search is this line. + +OK. + +So that's an algorithm, +a little loop there. + +So in this example we-- the +point of what's going on + +and the reason this +algorithm is correct + +is we just modified +these three segments. + +And we replaced +these three segments + +with a single segment which +looks something like that. + +And the rest, the parts to +the left and to the right + +are the same. + +I still claim we need +to back up one segment + +and look at this one again, +because now potentially + +this one might be crimpable +whereas it wasn't before. + +Because we changed +this length, it + +may have gotten +longer potentially. + +Or shorter. + +It could have changed. + +So this pair may be crimpable +whereas it wasn't before. + +So just to make sure, +we'll go left one step, + +and then we'll check, is +that segment crimpable? + +Is this one? + +Is this one? + +And just keep going. + +And I'm guessing +this pattern is not + +is not flat foldable +because of these two. + +We could check. + +Did I miss one? + +V, M, M. M is the little thing. + +So I think this +is going to crimp. + +And then this will +get end folded. + +But still this is a problem +because of the two M's. + +So this will not flat fold. + +We'll be left with +something like this, + +which is the two M's +and then we say, oh. + +We'll reach the stop case. + +Can't find a crimp +or and end fold + +and there are +still creases left. + +And so we know that +we're not flat foldable. + +But the reason I'm doing this +fast resume of the search, + +continuing the search +from one step to the left, + +is because we get a +good running time. + +I'm going to use running +time notation of order n. + +This means some +constant times n. + +We don't really care what the +constant is, but the growth is + +linear in the number +of creases that's n. + +And the reason it's +linear is that the number + +of rightward steps +that we make is + +going to be equal to n plus +the number of leftward steps. + +Why is that? + +Because overall the search +is going left to right, + +and if it doesn't find +anything it just takes n steps. + +You look at all the creases +or all the segments. + +It's basically n, +n plus 1, whatever. + +For each one, you check is +it crimpable, end foldable. + +That takes constant time. + +You're just comparing +a couple of numbers. + +So I'm counting the +number of rightward steps. + +The trouble with the +search is that every time I + +find a fold to do +I go back one step + +and so I'm kind +of losing progress + +because I go backwards. + +There's actually two +reasons why that's OK. + +One is you're also decreasing +n at the same time, + +because you're replacing +3 things with 1 thing, + +so n goes down by 2. + +But also, in order to +make a rightward step + +either it's in the +full search or it's + +because you went back one and +you have to go right again. + +So this is true. + +And the point is the number +of leftward steps is also + +at most n, because +every time you + +do a leftward step +you did a fold, + +and there's only +n folds to make. + +So-- it's actually less, +because crimps do two at a time. + +But the point is +this is at most 2n. + +And so the number of rightward +steps we make is linear. + +And so the overall +running time is linear. + +For the algorithms people, this +is a very simple amortization + +argument. + +We're charging the +leftward steps to the folds + +that we're doing. + +So that's an easy way to +do 1D flat foldability + +testing for mountain +valley patterns. + +Yes? + +AUDIENCE: Why do you +need to go back a step? + +So, the segment +that you labelled x, + +its new length is x plus +the quantity z minus y, + +and z is greater than y. + +So it's x plus a +positive number, right? + +So it's only increasing +in length, not decreasing. + +PROFESSOR: Only increasing. + +But that's of interest, right? + +Because if you had something +that wasn't crimpable + +because this was too short, and +then-- OK, here's an example. + +Good question. + +I hadn't thoroughly checked. + +So we scan. + +This guy's not crimpable +because this guy's too short. + +Then we reach-- suppose +then we jump to this guy. + +I'll do valley mountain to make +this definitely not crimpable. + +We look at this guy. + +We do the crimp. + +And now suddenly we have +this nice big length. + +And so now this +pair is crimpable. + +Good. + +So that's why we need +to go back a step. + +After we crimp +this guy, this one + +becomes crimpable +if it wasn't before. + +Yeah. + +I could have easily believed +that this step wasn't + +necessary, but it +definitely doesn't hurt + +and it is indeed necessary. + +The key is that we don't have +to back up more than one step, + +because we're only changing +our neighbors, basically. + +Other questions +about this algorithm? + +OK, well once we have this for-- +this is really for lecture two + +material, we can adapt it to +lecture three material, which + +is the circular case. + +Instead of having a line +we have a circle of paper. + +In that case, we only +need to look for crimps, + +and so we do the same +thing for crimps. + +I don't think I really need to +write this down, but algorithm + +for a single vertex +mountain valley pattern. + +It's basically the +same algorithm. + +Instead of wherever +you see left and right + +you replace it with clockwise +and counterclockwise + +going around in a circle. + +There's no obvious +starting point + +you just start at an arbitrary +segment, which in this case + +is an angle of the +crease pattern. + +Maybe I should draw a +little crease pattern, just + +for a picture. + +So you start, let's +say, at this segment. + +You see is this pair crimpable. + +If not continue, +let's say, clockwise. + +Keep going. + +If you ever find a crimpable +pair, like these two guys-- + +maybe this is +mountain and valley + +and this is a locally +smallest angle-- + +you do the crimp, meaning +you replace this angle x y + +and z with x minus y +plus z, just as before. + +And then you step +counterclockwise one step. + +And the point is +the invariant you're + +maintaining at all times during +this algorithm, the interval + +of the segments from the very +first segment you went to, + +up to but not +including the segment + +you're currently +looking at, those + +are all guaranteed not +crimpable at the moment. + +And so when you do a crimp, +that may invalidate this one, + +and so you have to step +backwards because you're not + +sure whether that one's +crimpable anymore. + +But you maintain that invariant. + +And so when if you ever get +back to the original angle + +that you were considering, +the original segment, + +then you know that in fact +everything is not crimpable, + +and then you're in trouble. + +Maybe. + +Except for this issue +which I also forgot about + +in lecture three-- I mean, I +didn't forget about this time, + +but I forgot about it then-- +which is in the base case. + +You can never actually do +everything by crimping, + +because at the +very end your hope + +is that you have a cone +with two creases that + +are both the same orientation. + +That is your goal. + +You know that there's two more +mountains or two more valleys + +and crimps pair them up. + +So you hope that you end +up with the situation. + +If you do, and these +two angles are equal, + +then you're flat foldable. + +You have that one +last fold to make. + +Otherwise, if you have anything +else, you're not flat foldable. + +That's what we proved +in lecture three, + +is that crimps are enough to +get down to this situation + +where you have only +two creases left, + +and that's what's foldable +when you only have two creases. + +OK so this is becoming a cone +as soon as you do operations. + +It's just like the +analysis we did. + +But this algorithm +will run in linear time + +for the same reason. + +The number of clockwise +steps equals at most n + +plus the number of +counterclockwise steps. + +And so I guess I should +maybe write "at most." + +And so this is +linear time as well. + +Any questions about +those algorithms? + +Yeah. + +AUDIENCE: For the +simple one, could you + +run into some edge case +where the very last crimp + +you considered makes the +very first one, which + +wasn't crimpable, +crimpable and then you + +have to go around +the circle again? + +PROFESSOR: Ah. + +OK. + +Good question. + +Right. + +So we said, OK, this is +guaranteed not crimpable, + +but if you then crimp +the very last segment + +this one may become crimpable, +and then that may propagate + +and force you to go +around a second time. + +AUDIENCE: So if that happens +at each step, then at each step + +you go all the way around, +and it could become quadratic. + +PROFESSOR: Ooh, interesting. + +AUDIENCE: But I'm +not sure if it's + +possible for that to +happen every step. + +PROFESSOR: Good. + +Well, this is the nature +of new algorithms. + +Yeah. + +AUDIENCE: The set of +possibly crimpable things + +increases by at most 1 every +time-- or at most 2 every time + +you make a crimp. + +PROFESSOR: Yeah. + +So certainly you will only have +to go around at most n times, + +but a quadratic bound +overall is not very exciting. + +AUDIENCE: So it stays linear. + +The interval in which things +are possibly crimpable + +expands by at most 2 every +time you make a crimp. + +PROFESSOR: I see. + +OK. + +So this is a different +algorithm, unfortunately. + +But you maintain the +interval of things + +that are guaranteed +not crimpable + +and you can look at +both ends whether you + +can crimp something. + +If you can, fine, you do it. + +You shrink the +interval a little bit. + +So in general your interval +is-- I have colored chalk, + +I should use it-- your +interval is an interval. + +It starts somewhere, +ends somewhere. + +And you're checking +is this guy crimpable. + +If it's not crimpable +you can extend + +the interval a little bit. + +If it is crimpable +you do the fold + +and you actually shrink +the interval a little bit. + +But every time you shrink +the interval, you did a fold, + +and that only happens n times. + +Every time you grow the +interval, you grew the interval + +and you can only grow n times. + +Good. + +So that will clean +up this situation. + +If this ends up being +crimpable, you just + +shrink the interval +from the other side. + +So I guess if I +wanted to just tweak + +this algorithm I would +change the notion of first. + +So I said, oh, this guy is +the first one that I visited. + +But if I end up +crimping this guy, + +I have to advance the first +to be the very next interval. + +Good. + +Thank you. + +All right. + +I'll correct that in +the notes as well. + +It was almost correct. + +Think now that +should be correct. + +Thanks for checking. + +And now we can do +it in linear time. + +There's a different +algorithm in the textbook, + +which uses more data structures. + +This I like because +it's very simple. + +It's just, like, storing +two pointers and that's it. + +Other questions? + +OK. + +That does algorithms. + +That was the new material +I wanted to cover. + +Then there is the other-- +the actual algorithm that + +was briefly described in class +is this local foldability + +algorithm. + +So you have now not +just a single vertex, + +but you have a whole +crease pattern. + +You'd like to assign a mountain +valley assignment to it that + +is at least locally +good, that when + +you run this algorithm +at each vertex it gives + +the right answer, it +says that, yeah, it's + +locally foldable +for each vertex. + +It doesn't mean the whole +thing will fold flat, + +but it's a start, at least. + +It's a necessary +condition for that. + +So I just want to give +you a few examples + +of this algorithm, +because it is confusing. + +I didn't do any +examples in lecture. + +It's always been the most +confusing part to me, + +and especially this notion +of merging cycles and paths. + +So for starters, these are +the examples in the textbook. + +They're pretty simple, but at +least they'll get us warmed up. + +So the crease pattern +is the bold black lines. + +It's two of them. + +And in this case it's +the generic case, + +so there's a unique +pairing here. + +There's only one crimpable +pair, which are these two guys. + +This is the only +locally smallest angle. + +So those two have +to be crimped first. + +One's going to be a mountain, +one's going to be a valley. + +So we would write not +equals in this blue thing + +to represent that constraint. + +This will be all that's left. + +And so these two guys +have to be equal. + +It's symmetric, so it looks +the same all the way around. + +And so when you see, OK, these +two guys have to be not equal, + +but also these two guys +have to be not equal, + +but also these two guys +have to be not equal, + +this is what we call a +cycle of constraints. + +In general, you get paths. + +Like, this one starts +and ends at infinity, + +so these two guys +have to be equal, + +these two guys have to be equal. + +They could both be mountain, +both be valley, doesn't matter. + +These are the only constraints. + +But this cycle-- +cycles can be problems, + +and here because it's +an odd cycle of not + +equals there's no +way to assign it. + +If you say mountain, +valley, mountain, + +then these two guys +are both mountains, + +which violates that constraint. + +In general, the +number of not equals + +should be even in each cycle. + +If it's ever an odd number of +not equals, you're in trouble. + +Here's an example where +the cycle is even, + +but we end up with +an equals here, + +and so the number of +not equals is still odd, + +so this is also bad. + +I mean, it's just replacing this +segment with two equal creases. + +Still can't assign a +mountain or valley. + +But these are kind +of simple examples. + +These are cycles and everything +was uniquely determined here. + +You had to crimp this guy first. + +You had to crimp this guy first. + +There was no choice. + +And the tricky part +of the algorithm + +is when you have choice, when +you have multiple equal angles, + +you don't know what +to crimp first. + +The algorithm just +crimps one of them first, + +but then it might +have to fix things. + +So I came up with +a simple example + +where you have to do that. + +I think it will help clarify +how this merging really happens. + +So the example is-- it's hard +to draw an equilateral triangle + +with accurate angles, +but I'll do my best-- + +and then these are supposed +to be right angles. + +OK. + +So that's my crease pattern. + +And some of this is forced. + +This guy-- at this vertex, this +is the only locally smallest + +angle. + +It's only 60 degrees, +these are 90. + +This is bigger than 90. + +So this has to be crimped +first, and it's not equal. + +That means these guys are equal. + +We don't really +care about those. + +And it's symmetric, +so not equal, equal. + +OK. + +But here we have a choice. + +There's two 60 degree angles. + +This does not look +very flat foldable. + +I think I'd better add +some more creases there. + +Got to have to even +parity at every vertex. + +So now we have a choice. + +Do we crimp this one first or +do we crimp the other one first? + +At this point, it's symmetric, +so I'll do this one first. + +This'll be my pairing. + +And there are two +possibilities here. + +Either I crimp this one first +or crimp this one first. + +The algorithm doesn't care. + +So let's suppose it does +this one, because this + +is the bad one. + +OK. + +Now we have a cycle with +an odd number not equals. + +So this is not +possible to satisfy. + +The algorithm +doesn't stop there. + +It says, OK, I have these paths. + +There's a cycle here +that's a problem, + +then I also have a path up here. + +How does it go? + +There's a path that goes +here, here, here, here. + +And there's a path +that goes here. + +But really it looks at the +vertices that had choice. + +It says, look, at +this moment I had + +a choice between whether to +fold this angle or this angle. + +In general, it might have +been a bunch of equal angles. + +We see here that there's a cycle +that the other choice would've + +involved a path. + +And so we merge. + +In general, if there's +two different things-- + +one could be a cycle, +one could be a path, + +they could both be cycles, +they could both be paths, + +whatever-- if I ever +have the opportunity + +to join those two parts +together I'll do it. + +So in other words, I do +the other crease first. + +Let me draw that. + +What that means will become +clear once we actually do one. + +So I want to do this first. + +The rest is the same. + +OK. + +So in that situation, what do +my paths and cycle look like? + +Well, there was this path +that started over here. + +It used to go like this, but +now this vertex has changed. + +So it's going to do something +different at that vertex. + +Now it goes over this way. + +I'm just following +the constraints. + +Now those two guys are +constrained to be different. + +And these are +constrained to be equal. + +So lo and behold we merged +a path and the cycle + +and we got a single path. + +The other paths remain the same. + +Just these two guys +got interchanged. + +What we're doing is basically +turning here and turning here + +instead of going that +way and going that way. + +And whenever you have two pieces +like this, and one of which + +is a cycle, you will do a merge. + +Merging can only help +us, because they'll + +get bigger and +bigger and bigger. + +The bigger these +sets of constraints + +are, essentially, +the better chance + +that you'll get +the parity right. + +I can never-- and this +is argued in the notes, + +but few-- it never hurts to +merge something, is the point. + +And if you're lucky-- if you, +say, merge two odd cycles-- + +they will become even. + +If you merge with a path, +you'll become a path. + +And so you're golden. + +Paths are always good. + +And so this thing becomes +flat foldable, or at least + +locally flat foldable. + +And we can mark in a +crease pattern, I guess. + +You could make this-- that's +going to be hard to see, + +I think-- mountain, valley, +mountain, valley, mountain-- + +oh, sorry-- equals, not equals, +this is not equals, not equals, + +not equals, equals. + +These guys are free. + +So you can make one +of them mountain, + +one of--- you can make them +all mountains, I guess. + +Or not. + +OK. + +This is a locally +valid flat folding. + +And it's hard to tell +whether it actually works + +except by folding it. + +So here I made one. + +That's the top side, I think. + +Ideally I got the same +crease pattern as here. + +The reds are mountains. + +Looks the same. + +And then-- + +It's clear that this pattern +is flat foldable, right? + +You just simple fold +here, and then you've + +got a single vertex and that +single vertex is flat foldable. + +But this does not do that. + +It does a kind of twist. + +It's kind of a fun mountain +valley assignment for it. + +So in this case it works. + +In general, you might get +some weird mountain valley + +assignment that doesn't work. + +But something simple +like this pattern, + +which has four +vertices, always will. + +Any more questions +about local foldability? + +That gives you at least an idea +of what the merges look like. + +It's hard to draw a huge +example, but-- Yeah. + +AUDIENCE: So the +generic case, you + +don't really have +a choice at any-- + +PROFESSOR: In the generic +case you have no choices, + +and so you've got to-- you +just check, does it work. + +And if it-- + +AUDIENCE: If you have +an odd number of faces, + +odd number of sides, then +it's not going to work? + +PROFESSOR: If you have a face +with an odd number of sides, + +that might be fine. + +It depends on these +assignments, whether they're + +not equal or equals. + +Like if this were an equal +sign, then you'd be happy. + +And that would +happen, for example, + +if you move these +creases to be very small. + +I'd have to also make this +one proportionally big, which + +is possible if I move +this vertex way over here. + +I'll have a triangle. + +This will have a big angle. + +Then I can have a +small angle here + +and these two guys +will be made not equal + +and these two will +be made equal, + +and then the parity's fine. + +So if you have a cycle with +an odd number of not equals, + +then you're screwed. + +In the generic case +there's nothing you can do. + +When you have equal angles, +when you had a choice, + +you go back and check whether +the choices would do merges. + +If you do, you do them. + +Overall, this turns out +to take a linear time + +if you're careful, because you +can only merge so many times. + +You have at most n parts and +each merge-- with some care. + +You need fancy data structures +to get this to work. + +You need find stuff, +but then you'll + +get linear time over all. + +Other questions? + +AUDIENCE: So what's the +definition of merging, again? + +PROFESSOR: So the +definition of merging + +is you look at every time +you had a choice in running + +this algorithm-- which you have +to not just run this algorithm + +but you have to maintain all +the choices that you had made. + +So whenever you had two +equal angles-- in general, + +the algorithm is you look at +a sequence of equal angles. + +The algorithm maybe +chooses the first one, + +but you could have chosen any. + +You see for each of the +other possibilities, + +would that end up combining +two of the components. + +So the constraints sort of join +together either into cycles + +or into paths, like this guy. + +And we just check, if +I do this other change, + +does it end up combining +two of those components? + +Before I had 1, 2, +3, 4 components. + +Now I only have 3 components. + +So just see what happens. + +If that decreases the number +of components I do it. + +And you can guarantee +this never hurts you. + +Keep merging components +until you can't anymore. + +And then either it +works and you've + +got no parity problems or no +cycles, or it doesn't work. + +If it doesn't work, there is +no local foldable assignment. + +Yeah. + +AUDIENCE: When you +say it's linear, + +are you counting +vertices or edges? + +PROFESSOR: Let's say number +of vertices plus edges. + +That's the safe way to define +n and then linear in that. + +Or if you count +the endpoints here + +it doesn't matter whether you +just count vertices or edges. + +The sum of the two +is always safe. + +So n usually just means +the size of the input, + +and those vertices and edges, +so why not just count them both. + +Other questions? + +Cool. + +So that's local foldability. + +I just have a few +more little things + +and then you can +ask more questions. + +Oh, sorry. + +I have one more example. + +I forgot. + +This is an example where +everything works fine. + +You don't get any cycles. + +But it's kind of a fun example. + +The crane. + +I'd never analyzed it +before, so I spent the time + +to draw one of these pictures. + +So first I just put a +bunch of circles down, + +and I look for things that +are forced, just because that + +is more interesting. + +I tried to make it +as bad as possible. + +It turns out I couldn't +make it that bad. + +But this guy's +forced, because it's + +the only locally smallest angle. + +And then it's +symmetrical around. + +So this guy's forced. + +Four of them should be forced. + +If I advance, yeah. + +This one, this one. + +Those are all forced +to be not equal. + +The rest are equal. + +The other guys have ambiguity. + +And I tried. + +I thought this would be a +great place to find the cycle + +and then we could resolve +the cycle, because I know + +this should work in the end, +but I couldn't make a cycle. + +It's not possible, because +there's sort of this cut point + +here. + +And you once you go to +one side of the pattern, + +you can't come back +to the other side. + +I could make a really +long path though. + +So I chose-- there's +a lot of choices here, + +but the algorithm +just chooses one. + +I tried to make the +longest path I could. + +It's kind of a fun puzzle. + +Not that hard to solve. + +It gets a little hard +to draw these pairings. + +Here these two guys are +paired together as not equal. + +We crimp that first. + +Then let's say we +crimp these two. + +Then we've got two +angles here, each + +of which I think is 90 degrees +after you do the crimps. + +And so these two guys +have to be equal. + +That's what this notation means. + +So here there were, I think +four different possibilities. + +And if you trace all the +paths, you get these guys. + +So there's some simple paths +out here, but then there's + +this purple path in the +middle, which starts here, + +goes up here, over here, +over here, along this crease, + +over here, here, here, here, up +there, here, here, there, back, + +forth, and then it +escapes in the corner. + +So you get a mountain valley +assignment out of this. + +I didn't test whether +it was possible. + +Probably not. + +Anyway, you get something, +and it might be possible. + +Exercise for you to try at home. + +All right. + +That took some time to draw. + +Cool. + +That's local foldability. + +Now with the +Kawasaki condition, I + +mentioned briefly +in lecture three + +that-- We were talking +about convex cones, where + +the amount of material is +less than or equal to 360. + +Someone pointed out and +said, oh, out of paper + +you can't make +something more than 360. + +And it's true if you start +from one sheet of paper. + +But if you start with +multiple sheets of material + +and join them together, like +sew them up, like in a T-shirt, + +you can get non-convex +cones, meaning + +more than 360 degrees +of material here. + +This is, let's say, +270, let's call it? + +So you double that, +because there's + +a front side and the +back side of the T-shirt. + +Easier to see in a 3D one. + +You've got more than 360 degrees +of material in the armpits. + +So, yes, it's true. + +And what happens, as I mentioned +briefly, is there's a new case. + +There's sort of +two situations when + +you have a kind of a mess +of material like this, + +more than 360 +degrees of material. + +There are two possibilities. + +Either you end up folding it to +lie in less than a full circle, + +in terms of the boundary, +and then it's just like here. + +The alternating sum +should be equal to 0. + +Or you end up folding it +so that it encompasses + +an entire circle, +and then you end up + +with this alternating sum of +angles being plus or minus 360. + +And it's in the textbook. + +It's not so easy to prove +that that's all that happens, + +but you-- Basically, you +can't twist multiple times, + +because then you'd end +up with a crossing. + +So it's not that much +harder to analyze + +these kinds of situations. + +You can do it. + +But this is a +great excuse for me + +to show cool ways +to fold T-shirts. + +How many people seen this video? + +most. + +It's like six years old. + +Have you ever tried it? + +[LAUGHTER] + +I brought an extra +little T-shirt here. + +This is totally for fun. + +You pinch here and here. + +Bring this side over here. + +You pinch. + +You do a nice +flourish, and then you + +get your perfectly +folded-- I didn't + +do it perfectly-- +T-shirt in one motion. + +As they say, in two seconds, +and it works for us. + +So it's a great T-shirts. + +And for fun, here's the-- +this is like the high tech way + +to do it. + +There's actually a whole bunch +of T-shirt folding machines. + +You push the button. + +It's a bunch of simple +folds, actually. + +So it's a nice little +simple folding machine. + +[LAUGHTER] + +It's kind of fun to watch. + +Seems like a lot of set up time. + +You have set up time with +the fast method also. + +So It's kind of fun. + +The same machine. you can also +wrap them directly into bags. + +Question? + +AUDIENCE: Have you +in clothing stores + +they have non-mechanical +versions of those + +that are just plastic boards. + +PROFESSOR: And you just-- + +AUDIENCE: That you can flop over +so that all your T-shirts are + +folded the same. + +PROFESSOR: It's not automated. + +Yes. + +You can actually buy-- I've +only seen them in stores rarely. + +They're usually +in the back room. + +But you can actually buy +this folding machine. + +It's like a giant piece of +plastic with exactly-- maybe + +only three creases, +I think typically. + +And then you just do them +in some order manually + +with simple folds, +and it does make + +really nicely folded T-shirts. + +Nicer than I could +fold by hand, anyway. + +All right. + +That was just for fun. + +While we're on the +topic of T-shirts. + +Next question is about +higher dimensions. + +So I mentioned +briefly, yeah, you + +can do higher +dimensional origami. + +Not much is known about it. + +So a natural thing to ask +about is flat foldability + +for higher dimensions. + +And there are exactly +two papers about this. + +Well, maybe even just one. + +The old one is this paper +by Kawasaki-- same guy + +as Kawasaki's condition-- +and this is in this book. + +This the first-- +this is a hard book + +to get a copy of, +First International + +Meeting of Origami +Science and Technology. + +These days it's called +Origami Science, Math, + +and Education, OSME. + +And this T-shirt is from +the latest one, which + +was in Singapore two +years ago, I think, 2010. + +Next one is in a +year or two in Japan. + +So this is the very first one. + +This is before my time. + +And there's this paper. + +It's a translated Japanese +paper, so it has a few typos. + +We also have the +Japanese original + +if you're interested in +reading this some time. + +You see, for example, +here is folding + +a regular piece +of paper in half. + +Here's folding a 3D +solid of paper in half. + +A little harder to +imagine, but there it is. + +And let's see, +what's in this paper? + +There's a definition, +although I would really + +call it a necessary condition. + +I think this is not +a good definition + +of flat origami in 3D. + +But there it is. + +This is the definition. + +What it says is basically, +locally everything works out. + +When you do a fold, +it's like a reflection. + +If you do it +instantaneously, this + +is like reflecting this +piece through the line + +for flat folding. + +This is like reflecting this +piece through the plane. + +And so one condition you +have is that if you-- it's + +easier to look at one of +the examples in the paper. + +So you have this +crease pattern, which + +you can draw by a bunch +of planes, let's say. + +If you kind of walk +around and say, OK, I + +go through this +crease, which means + +I reflect through +that plane, then + +I reflect through this plane, +this plane, this plane, + +you can take any sort of path, +any cycle through this world. + +In the end I should end +up back where I started. + +Otherwise I'm ripping. + +And what that condition +says is that if you + +take the sequence of reflections +and you compose them, + +you end up with no reflection +at all, that nothing moved. + +And so that's a necessary +condition for flat foldability. + +I wouldn't call it a definition, +although this paper did. + +Natural definition +is more like what + +we draw in 2D for +flat folding, where + +we add another layer, +another dimension, + +and then guarantee no +collisions in that dimension. + +So same thing in 3D. + +It's just harder to imagine +stacking up copies of 3D. + +Question? + +AUDIENCE: Doesn't the +reflection analogy + +only apply to +simple folds, where + +the plane goes all the way? + +PROFESSOR: OK. + +Good question. + +The reflection +analogy definitely + +applies to simple folds. + +It also applies to +non-simple folds. + +But it does require +straight folds, + +which here mean flat +folds, like planar folds. + +For curve creases, +you're not really + +reflecting, because +you can't fold + +a curve crease all the way. + +You can't fold it flat. + +But whenever you fold +something all the way-- so even + +in something like this, which is +not a simple fold in the end-- + +you can check. + +Essentially, this is what we-- +on the circle, when we said, + +OK, you walk this way and then +you just change direction. + +That's essentially +the reflection + +that's happening on the circle. + +If you live on the circle +you're reflecting in + +that you're immediately +bouncing back at that crease. + +It turns out to +hold in 2D as well. + +So if you look at the +effect of this crease, + +it is that you're reflecting +this part over that crease. + +I guess you can see +it in the folding too. + +I mean, you go over this +crease, then you hit this line, + +and then you immediately +bounce back at the line. + +That is actually a +reflection through the line. + +Good question. + +It's obvious for simple +folds, but reflection actually + +works here as well. + +We'll talk more about that in +the next lecture, I believe. + +OK. + +I was looking up reference, +any papers that cited that one, + +and there's basically +one paper, which + +is this kind of a +graphics/art/math paper talking + +about four-dimensional origami. + +It's basically some +simulations and some examples. + +Here's the not folding +all the way picture. + +A little harder to imagine. + +Here they're doing, I think, the +4D analog of a rabbit ear fold. + +Little hard to +tell, but first they + +do a simple fold +along a bisector. + +That I can understand. + +And then they do an +inside reverse fold. + +And then you end up with +1/4 of the tetrahedron. + +So if you divide, this is the +centroid of the tetrahedron. + +It's really hard to +draw these pictures. + +In the paper, they +actually showed two images, + +and if you align +them with your eyes + +then you'll see +a 3D image, which + +is of course a projection +of the 4D thing. + +They also have this one. + +Anyone have red-blue +glasses with them? + +Then you'll see this in 3D. + +Here you can watch that later. + +This is their 4D analog of +a flapping bird, I guess. + +It's pretty hard to see +these pictures, though + +But this is the state of the art +in 4D origami as far as I know. + +It's kind of neat to find. + +This is a pretty recent paper. + +Questions about +higher dimensions? + +Lots of things are open. + +For example, single +vertex flat foldability + +could be a neat problem. + +I don't think-- It may be +that Kawasaki's condition + +from that paper is enough. + +I don't know. + +Maybe not. + +OK. + +Last question, just kind +of a nice place to end + +is, why are we spending all +this time on flat foldability. + +Flat origami's kind of boring. + +And so why do we spend +all this time with it? + +It's good to check +why are we doing this. + +One answer of course is that +there's interesting mathematics + +here. + +It's kind of a natural question. + +Why not? + +That's the math cop-out answer. + +But there are actually a +lot of good answers as well. + +One answer is that flat origami +actually is pretty cool. + +There's a whole world of +flat tessellations, where + +you fold a repeating +pattern in your sheet. + +This is from a +rectangle of paper. + +What you're seeing here +is a shadow pattern. + +It's held up to a window, and +so you see this shadow pattern, + +which looks an awful lot like +a 6 by 6 by 6 Rubik's cube. + +That's the design here. + +You could make it even +larger if you want. + +Another answer is, well, +maybe I need to store stuff. + +And while I can +unfold things, it's + +kind of big when it's unfolded. + +If I could fold it +all the way flat-- + +maybe I care about the 3D +shape, but if I could fold it + +all the way flat, then it +would be easier to store. + +It's going to be smaller, more +compact, I can roll it up, + +I can do lots of things. + +Airbag folding is one example. + +Here you actually +start with a 3D shape. + +There's no sort of unfold. + +It's been sewn into a 3D shape. + +And then you want to collapse +it into some nice flat shape + +for storage in your steering +wheel, or the side of your car, + +or whatever. + +And this is an example of +folding using flat origami + +designs. + +This crease pattern is +based on the tree method, + +and other stuff we haven't +covered yet, fold and cut. + +So that's another. + +That's sort of the +practical answer. + +And then there's more +mathematical answers, + +deeper things. + +Even if you don't care about +flat folding by itself, + +it turns out to relate +to 3D folding as well. + +This is a paper +that's very cool. + +We have a guest lecture by +Tomohiro Tachi coming up. + +I haven't scheduled +exactly when it will be, + +because it's in the in the box. + +It's on tape. + +So we'll be watching +that at some point. + +He was actually just +visiting a couple weeks ago. + +And he has this +cool theorem which + +says that if you +have a plane or quad + +mesh-- so a particular kind of +crease pattern, every vertex + +has four incident increases, +every face is a quadrilateral-- + +and it's flat foldable-- +so you may not + +care about flat +foldability, but you + +need this Kawasaki +condition to guarantee + +that this will work-- then it +has a rigid folding motion, if + +and only if it has a 3D state. + +Let me show you some examples. + +So this a kind of a classic +origami called miura-ori. + +And it has this cool property +that even if these panels are + +made up out of rigid material +like sheet metal or plastic + +or whatever, if these are +hinges you can still fold it. + +And this is an +animation of it folding. + +And indeed it folds flat. + +And what the +theorem is saying is + +if you can build a 3D picture +like this, any one of these, + +that guarantees that there's +this folding motion-- not + +necessarily all the way to flat, +but at least part way to flat. + +And often you can get +it all the way to flat. + +And so Tomohiro's +developed software + +that lets you start +with something + +you know works-- so this +is a miura-ori that's + +been folded partly-- +and then just start + +pulling on the vertices and +messing it up and just changing + +the shapes. + +So this is not a folding. + +You're changing how the +paper fits together. + +You're changing +the crease pattern. + +As you do that, he keeps +track of the crease pattern + +and he adds constraints +to make sure + +that it stays flat foldable. + +The result is you end up with +a 3D embedding, a 3D folding, + +and you have a flat +foldable crease + +pattern that goes with it. + +And that guarantees +that you get a motion. + +Those two things. + +So this technique of +having flat foldability + +lets him design crazy +crease patterns that + +fold into whatever +shape he wants + +with a nice rigid motion where +all these panels stay rigid. + +So that's another motivation +for flat foldability. + +It's probably used +elsewhere as well, + +but this is kind of the +coolest, newest example I know, + +where it's just a +condition in the theorem, + +and in order to check +that condition you + +need to understand +flat foldability. + +Other questions? + +That's all I have for slides. + +Cool. + +That's the end of class. \ No newline at end of file diff --git a/ywl3pq6yc54.txt b/ywl3pq6yc54.txt new file mode 100644 index 0000000000000000000000000000000000000000..f3367c9e8a9ae1f5d5a795292a5157f3c136010d --- /dev/null +++ b/ywl3pq6yc54.txt @@ -0,0 +1,13195 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit MIT opencourseware + + align:start position:0% +of MIT courses visit MIT opencourseware + + + align:start position:0% +of MIT courses visit MIT opencourseware +at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu well today's today's topic + + align:start position:0% +ocw.mit.edu well today's today's topic + + + align:start position:0% +ocw.mit.edu well today's today's topic +is portfolio Theory and it's uh really + + align:start position:0% +is portfolio Theory and it's uh really + + + align:start position:0% +is portfolio Theory and it's uh really +one of the most important topics in + + align:start position:0% +one of the most important topics in + + + align:start position:0% +one of the most important topics in +finance + + align:start position:0% +finance + + + align:start position:0% +finance +um we're going to go through the uh + + align:start position:0% +um we're going to go through the uh + + + align:start position:0% +um we're going to go through the uh +historical theory of + + align:start position:0% +historical theory of + + + align:start position:0% +historical theory of +portfolio uh optimization uh beginning + + align:start position:0% +portfolio uh optimization uh beginning + + + align:start position:0% +portfolio uh optimization uh beginning +with marwitz mean variance + + align:start position:0% +with marwitz mean variance + + + align:start position:0% +with marwitz mean variance +optimization uh where we look at + + align:start position:0% +optimization uh where we look at + + + align:start position:0% +optimization uh where we look at +portfolios in terms of their performance + + align:start position:0% +portfolios in terms of their performance + + + align:start position:0% +portfolios in terms of their performance +characteristics as determined by their + + align:start position:0% +characteristics as determined by their + + + align:start position:0% +characteristics as determined by their +mean return and the volatility of + + align:start position:0% +mean return and the volatility of + + + align:start position:0% +mean return and the volatility of +returns uh this analysis uh gets + + align:start position:0% +returns uh this analysis uh gets + + + align:start position:0% +returns uh this analysis uh gets +extended by looking at also investing + + align:start position:0% +extended by looking at also investing + + + align:start position:0% +extended by looking at also investing +with a risk-free asset uh the initial + + align:start position:0% +with a risk-free asset uh the initial + + + align:start position:0% +with a risk-free asset uh the initial +Theory on folio analysis didn't consider + + align:start position:0% +Theory on folio analysis didn't consider + + + align:start position:0% +Theory on folio analysis didn't consider +investing in cash but just investing in + + align:start position:0% +investing in cash but just investing in + + + align:start position:0% +investing in cash but just investing in +Risky assets uh the problem changes + + align:start position:0% +Risky assets uh the problem changes + + + align:start position:0% +Risky assets uh the problem changes +quite dramatically when we add the + + align:start position:0% +quite dramatically when we add the + + + align:start position:0% +quite dramatically when we add the +risk-free + + align:start position:0% +risk-free + + + align:start position:0% +risk-free +asset uh then the topic of utility + + align:start position:0% +asset uh then the topic of utility + + + align:start position:0% +asset uh then the topic of utility +Theory uh vanoyan Morganstern utility + + align:start position:0% +Theory uh vanoyan Morganstern utility + + + align:start position:0% +Theory uh vanoyan Morganstern utility +Theory uh in uh statistical decision + + align:start position:0% +Theory uh in uh statistical decision + + + align:start position:0% +Theory uh in uh statistical decision +Theory uh we are trying to make + + align:start position:0% +Theory uh we are trying to make + + + align:start position:0% +Theory uh we are trying to make +decisions under uncertainty in a + + align:start position:0% +decisions under uncertainty in a + + + align:start position:0% +decisions under uncertainty in a +rational way and Von noyman and uh + + align:start position:0% +rational way and Von noyman and uh + + + align:start position:0% +rational way and Von noyman and uh +Morgan Stern uh developed a UT expected + + align:start position:0% +Morgan Stern uh developed a UT expected + + + align:start position:0% +Morgan Stern uh developed a UT expected +utility hypothesis for rational + + align:start position:0% +utility hypothesis for rational + + + align:start position:0% +utility hypothesis for rational +decision- making and that's really very + + align:start position:0% +decision- making and that's really very + + + align:start position:0% +decision- making and that's really very +important motivator for uh decision + + align:start position:0% +important motivator for uh decision + + + align:start position:0% +important motivator for uh decision +analysis generally and portfolio + + align:start position:0% +analysis generally and portfolio + + + align:start position:0% +analysis generally and portfolio +selection in particular so we'll go + + align:start position:0% +selection in particular so we'll go + + + align:start position:0% +selection in particular so we'll go +through that uh then we'll turn to + + align:start position:0% +through that uh then we'll turn to + + + align:start position:0% +through that uh then we'll turn to +portfolio optimization constraints there + + align:start position:0% +portfolio optimization constraints there + + + align:start position:0% +portfolio optimization constraints there +are realistic issues when you have well + + align:start position:0% +are realistic issues when you have well + + + align:start position:0% +are realistic issues when you have well +there's how much money you have to + + align:start position:0% +there's how much money you have to + + + align:start position:0% +there's how much money you have to +invest or how much Capital you have to + + align:start position:0% +invest or how much Capital you have to + + + align:start position:0% +invest or how much Capital you have to +invest whether you can short Securities + + align:start position:0% +invest whether you can short Securities + + + align:start position:0% +invest whether you can short Securities +or not uh whether there are uh sort of + + align:start position:0% +or not uh whether there are uh sort of + + + align:start position:0% +or not uh whether there are uh sort of +limits in capacity of different assets + + align:start position:0% +limits in capacity of different assets + + + align:start position:0% +limits in capacity of different assets +you might want to trade those can come + + align:start position:0% +you might want to trade those can come + + + align:start position:0% +you might want to trade those can come +into play and affect the + + align:start position:0% +into play and affect the + + + align:start position:0% +into play and affect the +solutions um all of these methods are + + align:start position:0% +solutions um all of these methods are + + + align:start position:0% +solutions um all of these methods are +driven by estimates of how well we + + align:start position:0% +driven by estimates of how well we + + + align:start position:0% +driven by estimates of how well we +expect assets to do so estimating + + align:start position:0% +expect assets to do so estimating + + + align:start position:0% +expect assets to do so estimating +returns are estimating + + align:start position:0% +returns are estimating + + + align:start position:0% +returns are estimating +Alphas uh and also estimating the + + align:start position:0% +Alphas uh and also estimating the + + + align:start position:0% +Alphas uh and also estimating the +volatilities and correlations amongst + + align:start position:0% +volatilities and correlations amongst + + + align:start position:0% +volatilities and correlations amongst +the assets we're trading in uh most of + + align:start position:0% +the assets we're trading in uh most of + + + align:start position:0% +the assets we're trading in uh most of +the theory we'll talk about today deals + + align:start position:0% +the theory we'll talk about today deals + + + align:start position:0% +the theory we'll talk about today deals +with uh estimates well with the problem + + align:start position:0% +with uh estimates well with the problem + + + align:start position:0% +with uh estimates well with the problem +where we're assuming basically uh + + align:start position:0% +where we're assuming basically uh + + + align:start position:0% +where we're assuming basically uh +certainty in terms of understanding + + align:start position:0% +certainty in terms of understanding + + + align:start position:0% +certainty in terms of understanding +those uh underlying uh return + + align:start position:0% +those uh underlying uh return + + + align:start position:0% +those uh underlying uh return +characteristics the means variances and + + align:start position:0% +characteristics the means variances and + + + align:start position:0% +characteristics the means variances and +correlations but when we have to + + align:start position:0% +correlations but when we have to + + + align:start position:0% +correlations but when we have to +estimate those that that raises new + + align:start position:0% +estimate those that that raises new + + + align:start position:0% +estimate those that that raises new +problems and finally we'll finish up + + align:start position:0% +problems and finally we'll finish up + + + align:start position:0% +problems and finally we'll finish up +talking about some alternative risk + + align:start position:0% +talking about some alternative risk + + + align:start position:0% +talking about some alternative risk +measures which extend the + + align:start position:0% +measures which extend the + + + align:start position:0% +measures which extend the +straightforward mean or simple mean + + align:start position:0% +straightforward mean or simple mean + + + align:start position:0% +straightforward mean or simple mean +variance + + align:start position:0% + + + + align:start position:0% + +analysis now now the mean variance + + align:start position:0% +analysis now now the mean variance + + + align:start position:0% +analysis now now the mean variance +analysis is a single period analysis uh + + align:start position:0% +analysis is a single period analysis uh + + + align:start position:0% +analysis is a single period analysis uh +what we want to do is consider investing + + align:start position:0% +what we want to do is consider investing + + + align:start position:0% +what we want to do is consider investing +our capital in some assets and we want + + align:start position:0% +our capital in some assets and we want + + + align:start position:0% +our capital in some assets and we want +to do so for just a single period and do + + align:start position:0% +to do so for just a single period and do + + + align:start position:0% +to do so for just a single period and do +so optimally um so in terms of notation + + align:start position:0% +so optimally um so in terms of notation + + + align:start position:0% +so optimally um so in terms of notation +we'll consider risky assets indexed by I + + align:start position:0% +we'll consider risky assets indexed by I + + + align:start position:0% +we'll consider risky assets indexed by I +1 through M single period returns will + + align:start position:0% +1 through M single period returns will + + + align:start position:0% +1 through M single period returns will +be a multivariant vector + + align:start position:0% +be a multivariant vector + + + align:start position:0% +be a multivariant vector +of those + + align:start position:0% +of those + + + align:start position:0% +of those +Returns the mean and covariance of this + + align:start position:0% +Returns the mean and covariance of this + + + align:start position:0% +Returns the mean and covariance of this +uh of these assets are represented in a + + align:start position:0% +uh of these assets are represented in a + + + align:start position:0% +uh of these assets are represented in a +vector of returns and a cence matrix of + + align:start position:0% +vector of returns and a cence matrix of + + + align:start position:0% +vector of returns and a cence matrix of +squared volatilities the variances of + + align:start position:0% +squared volatilities the variances of + + + align:start position:0% +squared volatilities the variances of +the assets along the diagonals and the + + align:start position:0% +the assets along the diagonals and the + + + align:start position:0% +the assets along the diagonals and the +co-variances on the off + + align:start position:0% +co-variances on the off + + + align:start position:0% +co-variances on the off +diagonals uh a portfolio will be + + align:start position:0% +diagonals uh a portfolio will be + + + align:start position:0% +diagonals uh a portfolio will be +represented as basically a waiting in of + + align:start position:0% +represented as basically a waiting in of + + + align:start position:0% +represented as basically a waiting in of +our investment in these M assets + + align:start position:0% +our investment in these M assets + + + align:start position:0% +our investment in these M assets +so we'll have a vector W consisting of + + align:start position:0% +so we'll have a vector W consisting of + + + align:start position:0% +so we'll have a vector W consisting of +W1 up to W1 giving the relative weights + + align:start position:0% +W1 up to W1 giving the relative weights + + + align:start position:0% +W1 up to W1 giving the relative weights +an absolute weights of those uh + + align:start position:0% +an absolute weights of those uh + + + align:start position:0% +an absolute weights of those uh +Investments uh we'll assume that we have + + align:start position:0% +Investments uh we'll assume that we have + + + align:start position:0% +Investments uh we'll assume that we have +one unit of capital to invest so the sum + + align:start position:0% +one unit of capital to invest so the sum + + + align:start position:0% +one unit of capital to invest so the sum +of these weights equals one and the + + align:start position:0% +of these weights equals one and the + + + align:start position:0% +of these weights equals one and the +portfolio return has uh expected return + + align:start position:0% +portfolio return has uh expected return + + + align:start position:0% +portfolio return has uh expected return +given by the expectation of this linear + + align:start position:0% +given by the expectation of this linear + + + align:start position:0% +given by the expectation of this linear +combination of the returns which is + + align:start position:0% +combination of the returns which is + + + align:start position:0% +combination of the returns which is +simply the the same linear combination + + align:start position:0% +simply the the same linear combination + + + align:start position:0% +simply the the same linear combination +of the underlying expectations and the + + align:start position:0% +of the underlying expectations and the + + + align:start position:0% +of the underlying expectations and the +co the variance of the portfolio is + + align:start position:0% +co the variance of the portfolio is + + + align:start position:0% +co the variance of the portfolio is +given by the variance of the weighted + + align:start position:0% +given by the variance of the weighted + + + align:start position:0% +given by the variance of the weighted +average of the individual returns which + + align:start position:0% +average of the individual returns which + + + align:start position:0% +average of the individual returns which +is given by this quadratic form in The + + align:start position:0% +is given by this quadratic form in The + + + align:start position:0% +is given by this quadratic form in The +covariance Matrix so uh you know we've + + align:start position:0% +covariance Matrix so uh you know we've + + + align:start position:0% +covariance Matrix so uh you know we've +gone through this uh or you understand I + + align:start position:0% +gone through this uh or you understand I + + + align:start position:0% +gone through this uh or you understand I +think these calculations from our + + align:start position:0% +think these calculations from our + + + align:start position:0% +think these calculations from our +discussion in Time series and that + + align:start position:0% +discussion in Time series and that + + + align:start position:0% +discussion in Time series and that +that's quite quite simple now let's + + align:start position:0% +that's quite quite simple now let's + + + align:start position:0% +that's quite quite simple now let's +before going into the theory for this + + align:start position:0% +before going into the theory for this + + + align:start position:0% +before going into the theory for this +let's look at the + + align:start position:0% +let's look at the + + + align:start position:0% +let's look at the +problem let's look at the portfolio + + align:start position:0% +problem let's look at the portfolio + + + align:start position:0% +problem let's look at the portfolio +analysis problem in a very simplified + + align:start position:0% +analysis problem in a very simplified + + + align:start position:0% +analysis problem in a very simplified +setting uh we're just going to consider + + align:start position:0% +setting uh we're just going to consider + + + align:start position:0% +setting uh we're just going to consider +two + + align:start position:0% +two + + + align:start position:0% +two +assets and talk about optimal portfoli + + align:start position:0% +assets and talk about optimal portfoli + + + align:start position:0% +assets and talk about optimal portfoli +is investing in these two assets so m + + align:start position:0% +is investing in these two assets so m + + + align:start position:0% +is investing in these two assets so m +equals + + align:start position:0% +equals + + + align:start position:0% +equals +2 the first asset uh has return R1 with + + align:start position:0% +2 the first asset uh has return R1 with + + + align:start position:0% +2 the first asset uh has return R1 with +mean .15 now I'm going to think of this + + align:start position:0% +mean .15 now I'm going to think of this + + + align:start position:0% +mean .15 now I'm going to think of this +as annualized returns so a 15% + + align:start position:0% +as annualized returns so a 15% + + + align:start position:0% +as annualized returns so a 15% +annualized return and a volatility of + + align:start position:0% +annualized return and a volatility of + + + align:start position:0% +annualized return and a volatility of +25% the second asset has expected return + + align:start position:0% +25% the second asset has expected return + + + align:start position:0% +25% the second asset has expected return +of 20% and a volatility of + + align:start position:0% +of 20% and a volatility of + + + align:start position:0% +of 20% and a volatility of +30% Sigma + + align:start position:0% +30% Sigma + + + align:start position:0% +30% Sigma +2 these assets are possibly correlated + + align:start position:0% +2 these assets are possibly correlated + + + align:start position:0% +2 these assets are possibly correlated +we'll let row denote the correlation + + align:start position:0% +we'll let row denote the correlation + + + align:start position:0% +we'll let row denote the correlation +between the two and a + + align:start position:0% +between the two and a + + + align:start position:0% +between the two and a +portfolio uh basically all the + + align:start position:0% +portfolio uh basically all the + + + align:start position:0% +portfolio uh basically all the +portfolios we can invest in uh so long + + align:start position:0% +portfolios we can invest in uh so long + + + align:start position:0% +portfolios we can invest in uh so long +as we are you know limited to a unit of + + align:start position:0% +as we are you know limited to a unit of + + + align:start position:0% +as we are you know limited to a unit of +capital and no shorting um are given by + + align:start position:0% +capital and no shorting um are given by + + + align:start position:0% +capital and no shorting um are given by +portfolios indexed by W basically the + + align:start position:0% +portfolios indexed by W basically the + + + align:start position:0% +portfolios indexed by W basically the +amount of money we invest in the second + + align:start position:0% +amount of money we invest in the second + + + align:start position:0% +amount of money we invest in the second +asset so RW is WR wr2 plus 1 minus WR + + align:start position:0% +asset so RW is WR wr2 plus 1 minus WR + + + align:start position:0% +asset so RW is WR wr2 plus 1 minus WR +wr1 that's the return on the portfolio + + align:start position:0% +wr1 that's the return on the portfolio + + + align:start position:0% +wr1 that's the return on the portfolio +that invests in that proport those + + align:start position:0% +that invests in that proport those + + + align:start position:0% +that invests in that proport those +proportions in the two assets the + + align:start position:0% +proportions in the two assets the + + + align:start position:0% +proportions in the two assets the +expected return is this linear + + align:start position:0% +expected return is this linear + + + align:start position:0% +expected return is this linear +combination which is given in Matrix + + align:start position:0% +combination which is given in Matrix + + + align:start position:0% +combination which is given in Matrix +form in the previous page or the pre on + + align:start position:0% +form in the previous page or the pre on + + + align:start position:0% +form in the previous page or the pre on +the lecture notes and the variance are + + align:start position:0% +the lecture notes and the variance are + + + align:start position:0% +the lecture notes and the variance are +squared + + align:start position:0% +squared + + + align:start position:0% +squared +volatility is what it's 1 - Omega 2 time + + align:start position:0% +volatility is what it's 1 - Omega 2 time + + + align:start position:0% +volatility is what it's 1 - Omega 2 time +the variance of R1 plus W ^2 times the + + align:start position:0% +the variance of R1 plus W ^2 times the + + + align:start position:0% +the variance of R1 plus W ^2 times the +variance of R2 then we have a cross uh a + + align:start position:0% +variance of R2 then we have a cross uh a + + + align:start position:0% +variance of R2 then we have a cross uh a +a covariance term that comes into + + align:start position:0% + + + + align:start position:0% + +play now the mean variance analysis that + + align:start position:0% +play now the mean variance analysis that + + + align:start position:0% +play now the mean variance analysis that +markwitz + + align:start position:0% +markwitz + + + align:start position:0% +markwitz +addressed basically looks at the + + align:start position:0% +addressed basically looks at the + + + align:start position:0% +addressed basically looks at the +feasible portfolio set + + align:start position:0% +feasible portfolio set + + + align:start position:0% +feasible portfolio set +okay we we simplify things by saying + + align:start position:0% +okay we we simplify things by saying + + + align:start position:0% +okay we we simplify things by saying +let's ju Focus just on the volatility or + + align:start position:0% +let's ju Focus just on the volatility or + + + align:start position:0% +let's ju Focus just on the volatility or +variance and the expected return of our + + align:start position:0% +variance and the expected return of our + + + align:start position:0% +variance and the expected return of our +portfolio so we can Define the uh + + align:start position:0% +portfolio so we can Define the uh + + + align:start position:0% +portfolio so we can Define the uh +feasible portfolio set as the collection + + align:start position:0% +feasible portfolio set as the collection + + + align:start position:0% +feasible portfolio set as the collection +of volatility return pairs for all the + + align:start position:0% +of volatility return pairs for all the + + + align:start position:0% +of volatility return pairs for all the +assets or for all the + + align:start position:0% +assets or for all the + + + align:start position:0% +assets or for all the +portfolios and uh so you know well what + + align:start position:0% +portfolios and uh so you know well what + + + align:start position:0% +portfolios and uh so you know well what +is piar that collection basically what's + + align:start position:0% +is piar that collection basically what's + + + align:start position:0% +is piar that collection basically what's +the universe of possible portfolios we + + align:start position:0% +the universe of possible portfolios we + + + align:start position:0% +the universe of possible portfolios we +could construct in this two-dimensional + + align:start position:0% +could construct in this two-dimensional + + + align:start position:0% +could construct in this two-dimensional +case it's going to be very simple in + + align:start position:0% +case it's going to be very simple in + + + align:start position:0% +case it's going to be very simple in +multi-dimensional cases it's more + + align:start position:0% +multi-dimensional cases it's more + + + align:start position:0% +multi-dimensional cases it's more +complicated but what portfolios are + + align:start position:0% +complicated but what portfolios are + + + align:start position:0% +complicated but what portfolios are +optimal + + align:start position:0% +optimal + + + align:start position:0% +optimal +suboptimal how do we choose or identify + + align:start position:0% +suboptimal how do we choose or identify + + + align:start position:0% +suboptimal how do we choose or identify +a particular portfolio to invest in how + + align:start position:0% +a particular portfolio to invest in how + + + align:start position:0% +a particular portfolio to invest in how +is that choice made and is there any + + align:start position:0% +is that choice made and is there any + + + align:start position:0% +is that choice made and is there any +special structure to these + + align:start position:0% +special structure to these + + + align:start position:0% +special structure to these +portfolios um what you'll see in the + + align:start position:0% +portfolios um what you'll see in the + + + align:start position:0% +portfolios um what you'll see in the +lecture today is that the uh marwitz + + align:start position:0% +lecture today is that the uh marwitz + + + align:start position:0% +lecture today is that the uh marwitz +Theory and extensions of that provide + + align:start position:0% +Theory and extensions of that provide + + + align:start position:0% +Theory and extensions of that provide +really elegant answers to these uh + + align:start position:0% +really elegant answers to these uh + + + align:start position:0% +really elegant answers to these uh +questions and but let's understand + + align:start position:0% +questions and but let's understand + + + align:start position:0% +questions and but let's understand +basically what's going on just with this + + align:start position:0% +basically what's going on just with this + + + align:start position:0% +basically what's going on just with this +two asset + + align:start position:0% +two asset + + + align:start position:0% +two asset +case and what I'm going to do here is uh + + align:start position:0% +case and what I'm going to do here is uh + + + align:start position:0% +case and what I'm going to do here is uh +just simulate 500 weekly + + align:start position:0% +just simulate 500 weekly + + + align:start position:0% +just simulate 500 weekly +returns with different values of the + + align:start position:0% +returns with different values of the + + + align:start position:0% +returns with different values of the +correlation between the two + + align:start position:0% +correlation between the two + + + align:start position:0% +correlation between the two +assets and we want to examine the + + align:start position:0% +assets and we want to examine the + + + align:start position:0% +assets and we want to examine the +cumulative returns of each + + align:start position:0% +cumulative returns of each + + + align:start position:0% +cumulative returns of each +asset the asset returns in terms of + + align:start position:0% +asset the asset returns in terms of + + + align:start position:0% +asset the asset returns in terms of +their means volatilities and + + align:start position:0% +their means volatilities and + + + align:start position:0% +their means volatilities and +correlations a plot of piar and the uh + + align:start position:0% +correlations a plot of piar and the uh + + + align:start position:0% +correlations a plot of piar and the uh +cumulative returns of each asset uh with + + align:start position:0% +cumulative returns of each asset uh with + + + align:start position:0% +cumulative returns of each asset uh with +the minimum variance portfolio so um let + + align:start position:0% +the minimum variance portfolio so um let + + + align:start position:0% +the minimum variance portfolio so um let +me just highlight here that what we want + + align:start position:0% +me just highlight here that what we want + + + align:start position:0% +me just highlight here that what we want +here is to be plotting Sigma Omega + + align:start position:0% +here is to be plotting Sigma Omega + + + align:start position:0% +here is to be plotting Sigma Omega +versus Alpha + + align:start position:0% +versus Alpha + + + align:start position:0% +versus Alpha +Omega um and we have two assets + + align:start position:0% +Omega um and we have two assets + + + align:start position:0% +Omega um and we have two assets +We + + align:start position:0% +We + + + align:start position:0% +We +have basically + + align:start position:0% +have basically + + + align:start position:0% +have basically +um Sigma 1 and Alpha 1 corresponds to + + align:start position:0% +um Sigma 1 and Alpha 1 corresponds to + + + align:start position:0% +um Sigma 1 and Alpha 1 corresponds to +our first asset Sigma 2 and Alpha + + align:start position:0% +our first asset Sigma 2 and Alpha + + + align:start position:0% +our first asset Sigma 2 and Alpha +2 corresponds to our second asset so + + align:start position:0% +2 corresponds to our second asset so + + + align:start position:0% +2 corresponds to our second asset so +this point here corresponds to + + align:start position:0% +this point here corresponds to + + + align:start position:0% +this point here corresponds to +W + + align:start position:0% +W + + + align:start position:0% +W +equals W equals uh + + align:start position:0% +equals W equals uh + + + align:start position:0% +equals W equals uh +zero and U the other corresponds to W + + align:start position:0% +zero and U the other corresponds to W + + + align:start position:0% +zero and U the other corresponds to W +equals 1 so uh R1 and + + align:start position:0% +equals 1 so uh R1 and + + + align:start position:0% +equals 1 so uh R1 and +R2 now what's going to happen when we + + align:start position:0% +R2 now what's going to happen when we + + + align:start position:0% +R2 now what's going to happen when we +combine the Assets in a + + align:start position:0% +combine the Assets in a + + + align:start position:0% +combine the Assets in a +portfolio well + + align:start position:0% +portfolio well + + + align:start position:0% +portfolio well +um let's take a + + align:start position:0% +um let's take a + + + align:start position:0% +um let's take a +look at the + + align:start position:0% + + + + align:start position:0% + +simulation and + + align:start position:0% + + + + align:start position:0% + +okay here is a + + align:start position:0% +okay here is a + + + align:start position:0% +okay here is a +graph of the + + align:start position:0% +graph of the + + + align:start position:0% +graph of the +simulated asset + + align:start position:0% +simulated asset + + + align:start position:0% +simulated asset +returns + + align:start position:0% +returns + + + align:start position:0% +returns +with basically a uh the mean returns + + align:start position:0% +with basically a uh the mean returns + + + align:start position:0% +with basically a uh the mean returns +given by 15% 25% volatility is 20 and 30 + + align:start position:0% +given by 15% 25% volatility is 20 and 30 + + + align:start position:0% +given by 15% 25% volatility is 20 and 30 +and with an asset correlation of zero so + + align:start position:0% +and with an asset correlation of zero so + + + align:start position:0% +and with an asset correlation of zero so +here's just a scatter plot of the weekly + + align:start position:0% +here's just a scatter plot of the weekly + + + align:start position:0% +here's just a scatter plot of the weekly +returns there's basically no apparent + + align:start position:0% +returns there's basically no apparent + + + align:start position:0% +returns there's basically no apparent +correlation there there actually is a + + align:start position:0% +correlation there there actually is a + + + align:start position:0% +correlation there there actually is a +sample correlation because the a sample + + align:start position:0% +sample correlation because the a sample + + + align:start position:0% +sample correlation because the a sample +from this uh these distributions does + + align:start position:0% +from this uh these distributions does + + + align:start position:0% +from this uh these distributions does +you know won't have perfectly zero + + align:start position:0% +you know won't have perfectly zero + + + align:start position:0% +you know won't have perfectly zero +correlation on top we have graphs of the + + align:start position:0% +correlation on top we have graphs of the + + + align:start position:0% +correlation on top we have graphs of the +cumulative returns of the two ass + + align:start position:0% +cumulative returns of the two ass + + + align:start position:0% +cumulative returns of the two ass +individual + + align:start position:0% +individual + + + align:start position:0% +individual +assets uh rather obviously the higher + + align:start position:0% +assets uh rather obviously the higher + + + align:start position:0% +assets uh rather obviously the higher +graph corresponds to the asset with + + align:start position:0% +graph corresponds to the asset with + + + align:start position:0% +graph corresponds to the asset with +higher return um the lower which is + + align:start position:0% +higher return um the lower which is + + + align:start position:0% +higher return um the lower which is +asset two and the green corresponds to + + align:start position:0% +asset two and the green corresponds to + + + align:start position:0% +asset two and the green corresponds to +asset + + align:start position:0% +asset + + + align:start position:0% +asset +one the graph on the right top right is + + align:start position:0% +one the graph on the right top right is + + + align:start position:0% +one the graph on the right top right is +the graph of the feasible set as we + + align:start position:0% +the graph of the feasible set as we + + + align:start position:0% +the graph of the feasible set as we +allocate between asset one and asset + + align:start position:0% +allocate between asset one and asset + + + align:start position:0% +allocate between asset one and asset +two and so by the simulation + + align:start position:0% +two and so by the simulation + + + align:start position:0% +two and so by the simulation +this you + + align:start position:0% +this you + + + align:start position:0% +this you +know this curve corresponds to the + + align:start position:0% +know this curve corresponds to the + + + align:start position:0% +know this curve corresponds to the +feasible set of + + align:start position:0% +feasible set of + + + align:start position:0% +feasible set of +portfolios and what's uh really + + align:start position:0% +portfolios and what's uh really + + + align:start position:0% +portfolios and what's uh really +remarkable um is that we can get uh + + align:start position:0% +remarkable um is that we can get uh + + + align:start position:0% +remarkable um is that we can get uh +basically a reduction in the volatility + + align:start position:0% +basically a reduction in the volatility + + + align:start position:0% +basically a reduction in the volatility +of the + + align:start position:0% +of the + + + align:start position:0% +of the +portfolio without compromising and in + + align:start position:0% +portfolio without compromising and in + + + align:start position:0% +portfolio without compromising and in +fact improving the return of the + + align:start position:0% +fact improving the return of the + + + align:start position:0% +fact improving the return of the +portfolio so if we invest fully in asset + + align:start position:0% +portfolio so if we invest fully in asset + + + align:start position:0% +portfolio so if we invest fully in asset +one we're at this point as we + + align:start position:0% +one we're at this point as we + + + align:start position:0% +one we're at this point as we +increase as we start allocating towards + + align:start position:0% +increase as we start allocating towards + + + align:start position:0% +increase as we start allocating towards +asset + + align:start position:0% +asset + + + align:start position:0% +asset +2 not only does the return of asset of + + align:start position:0% +2 not only does the return of asset of + + + align:start position:0% +2 not only does the return of asset of +the portfolio go up but the volatility + + align:start position:0% +the portfolio go up but the volatility + + + align:start position:0% +the portfolio go up but the volatility +goes + + align:start position:0% +goes + + + align:start position:0% +goes +down and uh let's see on + + align:start position:0% +down and uh let's see on + + + align:start position:0% +down and uh let's see on +the in this simulation what I've done is + + align:start position:0% +the in this simulation what I've done is + + + align:start position:0% +the in this simulation what I've done is +also plotted the uh Return of the + + align:start position:0% +also plotted the uh Return of the + + + align:start position:0% +also plotted the uh Return of the +portfolio corresponding to the minimum + + align:start position:0% +portfolio corresponding to the minimum + + + align:start position:0% +portfolio corresponding to the minimum +variance + + align:start position:0% +variance + + + align:start position:0% +variance +um so let's uh just look at the minimum + + align:start position:0% +um so let's uh just look at the minimum + + + align:start position:0% +um so let's uh just look at the minimum +variance + + align:start position:0% + + + + align:start position:0% + +portfolio + + align:start position:0% +portfolio + + + align:start position:0% +portfolio +um for a minute we have Sigma squar + + align:start position:0% +um for a minute we have Sigma squar + + + align:start position:0% +um for a minute we have Sigma squar +W is equal to 1 - + + align:start position:0% +W is equal to 1 - + + + align:start position:0% +W is equal to 1 - +w^2 + + + align:start position:0% +w^2 + + + + align:start position:0% +w^2 + +w^2 Sigma 2^ 2 this is Sigma 1^ + + align:start position:0% +w^2 Sigma 2^ 2 this is Sigma 1^ + + + align:start position:0% +w^2 Sigma 2^ 2 this is Sigma 1^ +2 and then plus Z in the case that + + align:start position:0% +2 and then plus Z in the case that + + + align:start position:0% +2 and then plus Z in the case that +there's no correlation between the two + + align:start position:0% +there's no correlation between the two + + + align:start position:0% +there's no correlation between the two +assets if we want to minimize this uh + + align:start position:0% +assets if we want to minimize this uh + + + align:start position:0% +assets if we want to minimize this uh +portfolio uh + + align:start position:0% +portfolio uh + + + align:start position:0% +portfolio uh +volatility we + + align:start position:0% +volatility we + + + align:start position:0% +volatility we +can take the derivative of that with + + align:start position:0% +can take the derivative of that with + + + align:start position:0% +can take the derivative of that with +respect to the weight and uh set that + + align:start position:0% +respect to the weight and uh set that + + + align:start position:0% +respect to the weight and uh set that +equal to + + align:start position:0% +equal to + + + align:start position:0% +equal to +zero so what's that equal to well it's + + align:start position:0% +zero so what's that equal to well it's + + + align:start position:0% +zero so what's that equal to well it's +uh let's see did I do this + + align:start position:0% +uh let's see did I do this + + + align:start position:0% +uh let's see did I do this +right actually just with the uh previous + + align:start position:0% +right actually just with the uh previous + + + align:start position:0% +right actually just with the uh previous +notes + + align:start position:0% + + + + align:start position:0% + +so yeah sorry R1 is equal to zero okay + + align:start position:0% +so yeah sorry R1 is equal to zero okay + + + align:start position:0% +so yeah sorry R1 is equal to zero okay +right okay so we have 2 1 minus W Sig 1^ + + align:start position:0% +right okay so we have 2 1 minus W Sig 1^ + + + align:start position:0% +right okay so we have 2 1 minus W Sig 1^ +2 * -1 + 2 W Sigma 2^ 2 is equal to + + align:start position:0% +2 * -1 + 2 W Sigma 2^ 2 is equal to + + + align:start position:0% +2 * -1 + 2 W Sigma 2^ 2 is equal to +Z and so the uh solving this we get w + + align:start position:0% + + + + align:start position:0% + +is equal + + align:start position:0% + + + + align:start position:0% + +to let's see you get one over Sigma 1^ + + align:start position:0% +to let's see you get one over Sigma 1^ + + + align:start position:0% +to let's see you get one over Sigma 1^ +2 sorry 1/ Sigma 2^ 2 / 1 over Sigma 1^ + + align:start position:0% +2 sorry 1/ Sigma 2^ 2 / 1 over Sigma 1^ + + + align:start position:0% +2 sorry 1/ Sigma 2^ 2 / 1 over Sigma 1^ +2 + 1 over Sigma 2^ 2 if you solve this + + align:start position:0% +2 + 1 over Sigma 2^ 2 if you solve this + + + align:start position:0% +2 + 1 over Sigma 2^ 2 if you solve this +out you basically get a + + align:start position:0% +out you basically get a + + + align:start position:0% +out you basically get a +waiting on the different assets which + + align:start position:0% +waiting on the different assets which + + + align:start position:0% +waiting on the different assets which +weights inversely proportional to their + + align:start position:0% +weights inversely proportional to their + + + align:start position:0% +weights inversely proportional to their +squared + + align:start position:0% +squared + + + align:start position:0% +squared +volatility and with + + align:start position:0% +volatility and with + + + align:start position:0% +volatility and with +this graph here you can see that it is + + align:start position:0% +this graph here you can see that it is + + + align:start position:0% +this graph here you can see that it is +the blue graph is a bit closer to asset + + align:start position:0% +the blue graph is a bit closer to asset + + + align:start position:0% +the blue graph is a bit closer to asset +one than to asset 2's cumulative return + + align:start position:0% +one than to asset 2's cumulative return + + + align:start position:0% +one than to asset 2's cumulative return +that corresponds to giving a slightly + + align:start position:0% +that corresponds to giving a slightly + + + align:start position:0% +that corresponds to giving a slightly +higher weight to asset one + + align:start position:0% +higher weight to asset one + + + align:start position:0% +higher weight to asset one +because whatever Sigma 1^ 2 is bigger + + align:start position:0% +because whatever Sigma 1^ 2 is bigger + + + align:start position:0% +because whatever Sigma 1^ 2 is bigger +than 1/ Sigma 2^ + + align:start position:0% +than 1/ Sigma 2^ + + + align:start position:0% +than 1/ Sigma 2^ +squ well let's look at what happen + + align:start position:0% +squ well let's look at what happen + + + align:start position:0% +squ well let's look at what happen +happens if + + align:start position:0% +happens if + + + align:start position:0% +happens if +we consider negative correlations + + align:start position:0% +we consider negative correlations + + + align:start position:0% +we consider negative correlations +between the two + + align:start position:0% + + + + align:start position:0% + +assets well actually okay before we do + + align:start position:0% +assets well actually okay before we do + + + align:start position:0% +assets well actually okay before we do +that + + align:start position:0% +that + + + align:start position:0% +that +um you know if you were going to choose + + align:start position:0% +um you know if you were going to choose + + + align:start position:0% +um you know if you were going to choose +one of these portfolios + + align:start position:0% +one of these portfolios + + + align:start position:0% +one of these portfolios +for uh investing you know are there any + + align:start position:0% +for uh investing you know are there any + + + align:start position:0% +for uh investing you know are there any +portfolios that you wouldn't invest + + align:start position:0% + + + + align:start position:0% + +in and are any of these portfolios + + align:start position:0% +in and are any of these portfolios + + + align:start position:0% +in and are any of these portfolios +suboptimal in terms of mean variance + + align:start position:0% + + + + align:start position:0% + +W well W1 is certainly + + align:start position:0% +W well W1 is certainly + + + align:start position:0% +W well W1 is certainly +infeasible in terms of because we can + + align:start position:0% +infeasible in terms of because we can + + + align:start position:0% +infeasible in terms of because we can +all we can increase its mean and we can + + align:start position:0% +all we can increase its mean and we can + + + align:start position:0% +all we can increase its mean and we can +increase its uh and decrease its + + align:start position:0% + + + + align:start position:0% + +volatility so actually all of these + + align:start position:0% +volatility so actually all of these + + + align:start position:0% +volatility so actually all of these +points here are really suboptimal + + align:start position:0% +points here are really suboptimal + + + align:start position:0% +points here are really suboptimal +portfolios and from the minimum variance + + align:start position:0% +portfolios and from the minimum variance + + + align:start position:0% +portfolios and from the minimum variance +portfolio which is basically getting us + + align:start position:0% +portfolio which is basically getting us + + + align:start position:0% +portfolio which is basically getting us +you know the vertical tangent all the + + align:start position:0% +you know the vertical tangent all the + + + align:start position:0% +you know the vertical tangent all the +points from here up to the uh asset to + + align:start position:0% +points from here up to the uh asset to + + + align:start position:0% +points from here up to the uh asset to +fully investing in asset 2 are are are + + align:start position:0% +fully investing in asset 2 are are are + + + align:start position:0% +fully investing in asset 2 are are are +uh feasible and none of these portfolios + + align:start position:0% +uh feasible and none of these portfolios + + + align:start position:0% +uh feasible and none of these portfolios +is dominates the other basically it's a + + align:start position:0% +is dominates the other basically it's a + + + align:start position:0% +is dominates the other basically it's a +trade-off between return and + + align:start position:0% + + + + align:start position:0% + +volatility okay so so that's a really + + align:start position:0% +volatility okay so so that's a really + + + align:start position:0% +volatility okay so so that's a really +important point that uh you know there + + align:start position:0% +important point that uh you know there + + + align:start position:0% +important point that uh you know there +really are portfolios that you can just + + align:start position:0% +really are portfolios that you can just + + + align:start position:0% +really are portfolios that you can just +disregard um considering um the uh there + + align:start position:0% +disregard um considering um the uh there + + + align:start position:0% +disregard um considering um the uh there +are definite well when there's zero + + align:start position:0% +are definite well when there's zero + + + align:start position:0% +are definite well when there's zero +correlation there is a benefit to + + align:start position:0% +correlation there is a benefit to + + + align:start position:0% +correlation there is a benefit to +diversifying across these two assets so + + align:start position:0% +diversifying across these two assets so + + + align:start position:0% +diversifying across these two assets so +with if if you have an asset and you are + + align:start position:0% +with if if you have an asset and you are + + + align:start position:0% +with if if you have an asset and you are +considering uh pulling that asset with + + align:start position:0% +considering uh pulling that asset with + + + align:start position:0% +considering uh pulling that asset with +another in your portfolio if those are + + align:start position:0% +another in your portfolio if those are + + + align:start position:0% +another in your portfolio if those are +fully + + align:start position:0% +fully + + + align:start position:0% +fully +uncorrelated then you should be able to + + align:start position:0% +uncorrelated then you should be able to + + + align:start position:0% +uncorrelated then you should be able to +improve your portfolio by adding some + + align:start position:0% +improve your portfolio by adding some + + + align:start position:0% +improve your portfolio by adding some +allocation to that second asset let's + + align:start position:0% +allocation to that second asset let's + + + align:start position:0% +allocation to that second asset let's +look at the + + align:start position:0% +look at the + + + align:start position:0% +look at the +considering a negative a more negative + + align:start position:0% +considering a negative a more negative + + + align:start position:0% +considering a negative a more negative +autocorrelation or a more negative + + align:start position:0% +autocorrelation or a more negative + + + align:start position:0% +autocorrelation or a more negative +correlation between the two assets of + + align:start position:0% +correlation between the two assets of + + + align:start position:0% +correlation between the two assets of +minus + + align:start position:0% +minus + + + align:start position:0% +minus +point4 here you'll see that + + align:start position:0% +point4 here you'll see that + + + align:start position:0% +point4 here you'll see that +there's a basically a tilt a negative + + align:start position:0% +there's a basically a tilt a negative + + + align:start position:0% +there's a basically a tilt a negative +tilt to the scatter plot of + + align:start position:0% +tilt to the scatter plot of + + + align:start position:0% +tilt to the scatter plot of +returns and with the portfolios of two + + align:start position:0% +returns and with the portfolios of two + + + align:start position:0% +returns and with the portfolios of two +assets based of the feasible set that + + align:start position:0% +assets based of the feasible set that + + + align:start position:0% +assets based of the feasible set that +feasible + + align:start position:0% +feasible + + + align:start position:0% +feasible +set is actually stretching further to + + align:start position:0% +set is actually stretching further to + + + align:start position:0% +set is actually stretching further to +the + + align:start position:0% +the + + + align:start position:0% +the +left so with a negative correlation + + align:start position:0% +left so with a negative correlation + + + align:start position:0% +left so with a negative correlation +between the assets we're actually able + + align:start position:0% +between the assets we're actually able + + + align:start position:0% +between the assets we're actually able +to + + align:start position:0% +to + + + align:start position:0% +to +reduce the volatility even more if + + align:start position:0% +reduce the volatility even more if + + + align:start position:0% +reduce the volatility even more if +that's what you know is is our + + align:start position:0% +that's what you know is is our + + + align:start position:0% +that's what you know is is our +preference if we go up here to + + align:start position:0% +preference if we go up here to + + + align:start position:0% +preference if we go up here to +minus8 you it gets even more + + align:start position:0% +minus8 you it gets even more + + + align:start position:0% +minus8 you it gets even more +exaggerated now what's going to happen + + align:start position:0% +exaggerated now what's going to happen + + + align:start position:0% +exaggerated now what's going to happen +if we have a correlation of negative-1 + + align:start position:0% +if we have a correlation of negative-1 + + + align:start position:0% +if we have a correlation of negative-1 +between these two as + + align:start position:0% + + + + align:start position:0% + +assets yes then a portfolio the two + + align:start position:0% +assets yes then a portfolio the two + + + align:start position:0% +assets yes then a portfolio the two +assets can have zero variability so um + + align:start position:0% +assets can have zero variability so um + + + align:start position:0% +assets can have zero variability so um +in indeed with the + + align:start position:0% +in indeed with the + + + align:start position:0% +in indeed with the +hedging uh + + align:start position:0% +hedging uh + + + align:start position:0% +hedging uh +strategies um one often is considering + + align:start position:0% +strategies um one often is considering + + + align:start position:0% +strategies um one often is considering +you know investing in assets consisting + + align:start position:0% +you know investing in assets consisting + + + align:start position:0% +you know investing in assets consisting +of uh perhaps you know an underlying + + align:start position:0% +of uh perhaps you know an underlying + + + align:start position:0% +of uh perhaps you know an underlying +security and some derivative on that and + + align:start position:0% +security and some derivative on that and + + + align:start position:0% +security and some derivative on that and +that derivative you know if it's a + + align:start position:0% +that derivative you know if it's a + + + align:start position:0% +that derivative you know if it's a +future say you know could have basically + + align:start position:0% +future say you know could have basically + + + align:start position:0% +future say you know could have basically +a negative one correlation so you could + + align:start position:0% +a negative one correlation so you could + + + align:start position:0% +a negative one correlation so you could +essentially hedge out the the volatility + + align:start position:0% +essentially hedge out the the volatility + + + align:start position:0% +essentially hedge out the the volatility +almost perfectly so so that special case + + align:start position:0% +almost perfectly so so that special case + + + align:start position:0% +almost perfectly so so that special case +actually does exist uh quite frequently + + align:start position:0% +actually does exist uh quite frequently + + + align:start position:0% +actually does exist uh quite frequently +and is exploited um but it falls out + + align:start position:0% +and is exploited um but it falls out + + + align:start position:0% +and is exploited um but it falls out +just from this simple analysis of this + + align:start position:0% +just from this simple analysis of this + + + align:start position:0% +just from this simple analysis of this +uh this simple + + align:start position:0% +uh this simple + + + align:start position:0% +uh this simple +simulation okay let's also look at the + + align:start position:0% +simulation okay let's also look at the + + + align:start position:0% +simulation okay let's also look at the +uh going to increase in the + + align:start position:0% +uh going to increase in the + + + align:start position:0% +uh going to increase in the +correlation + + align:start position:0% +correlation + + + align:start position:0% +correlation +yes of the whole portfolio is zero does + + align:start position:0% +yes of the whole portfolio is zero does + + + align:start position:0% +yes of the whole portfolio is zero does +that mean it's valuable always mean + + align:start position:0% +that mean it's valuable always mean + + + align:start position:0% +that mean it's valuable always mean +constant equal to does that mean what so + + align:start position:0% +constant equal to does that mean what so + + + align:start position:0% +constant equal to does that mean what so +would that mean since it has zero + + align:start position:0% +would that mean since it has zero + + + align:start position:0% +would that mean since it has zero +variance so it will actually be constant + + align:start position:0% +variance so it will actually be constant + + + align:start position:0% +variance so it will actually be constant +over time the whole okay um I mean if it + + align:start position:0% +over time the whole okay um I mean if it + + + align:start position:0% +over time the whole okay um I mean if it +has zero variance then it should be + + align:start position:0% +has zero variance then it should be + + + align:start position:0% +has zero variance then it should be +constant over time yeah and zero + + align:start position:0% +constant over time yeah and zero + + + align:start position:0% +constant over time yeah and zero +variance means that over that that that + + align:start position:0% +variance means that over that that that + + + align:start position:0% +variance means that over that that that +it's its value is a + + align:start position:0% +it's its value is a + + + align:start position:0% +it's its value is a +constant um and so + + align:start position:0% +constant um and so + + + align:start position:0% +constant um and so +aide well it in terms of uh uh I + + align:start position:0% +aide well it in terms of uh uh I + + + align:start position:0% +aide well it in terms of uh uh I +and in in the markets nothing has zero + + align:start position:0% +and in in the markets nothing has zero + + + align:start position:0% +and in in the markets nothing has zero +or almost nothing has zero zero + + align:start position:0% +or almost nothing has zero zero + + + align:start position:0% +or almost nothing has zero zero +volatility um and uh so you know indeed + + align:start position:0% +volatility um and uh so you know indeed + + + align:start position:0% +volatility um and uh so you know indeed +but but the IDE but in in the pricing + + align:start position:0% +but but the IDE but in in the pricing + + + align:start position:0% +but but the IDE but in in the pricing +theory that uh chungong will be + + align:start position:0% +theory that uh chungong will be + + + align:start position:0% +theory that uh chungong will be +discussing uh in subsequent lectures if + + align:start position:0% +discussing uh in subsequent lectures if + + + align:start position:0% +discussing uh in subsequent lectures if +we have basically a portfolio which has + + align:start position:0% +we have basically a portfolio which has + + + align:start position:0% +we have basically a portfolio which has +no + + align:start position:0% +no + + + align:start position:0% +no +volatility then its return should be + + align:start position:0% +volatility then its return should be + + + align:start position:0% +volatility then its return should be +equal to whatever a risk free rate ought + + align:start position:0% +equal to whatever a risk free rate ought + + + align:start position:0% +equal to whatever a risk free rate ought +to be and so you know this particular + + align:start position:0% +to be and so you know this particular + + + align:start position:0% +to be and so you know this particular +portfolio ought to be structured so that + + align:start position:0% +portfolio ought to be structured so that + + + align:start position:0% +portfolio ought to be structured so that +it achieves a return equal to a + + align:start position:0% +it achieves a return equal to a + + + align:start position:0% +it achieves a return equal to a +risk-free rate barring transaction costs + + align:start position:0% +risk-free rate barring transaction costs + + + align:start position:0% +risk-free rate barring transaction costs +and frictions and all that kind of thing + + align:start position:0% +and frictions and all that kind of thing + + + align:start position:0% +and frictions and all that kind of thing +but um yeah okay uh so if we increase + + align:start position:0% +but um yeah okay uh so if we increase + + + align:start position:0% +but um yeah okay uh so if we increase +the correlation from from uh from + + align:start position:0% +the correlation from from uh from + + + align:start position:0% +the correlation from from uh from +zero uh to + + align:start position:0% +zero uh to + + + align:start position:0% +zero uh to +point4 well we still get a benefit of + + align:start position:0% +point4 well we still get a benefit of + + + align:start position:0% +point4 well we still get a benefit of +diversification but + + align:start position:0% +diversification but + + + align:start position:0% +diversification but +less um we're basically not able to + + align:start position:0% +less um we're basically not able to + + + align:start position:0% +less um we're basically not able to +lower the variance as much + + align:start position:0% +lower the variance as much + + + align:start position:0% +lower the variance as much +um and it's even more exaggerated with a + + align:start position:0% +um and it's even more exaggerated with a + + + align:start position:0% +um and it's even more exaggerated with a +correlation + + align:start position:0% +correlation + + + align:start position:0% +correlation +of8 + + align:start position:0% + + + + align:start position:0% + +um now in looking + + align:start position:0% +um now in looking + + + align:start position:0% +um now in looking +at these or the simulation I one thing I + + align:start position:0% +at these or the simulation I one thing I + + + align:start position:0% +at these or the simulation I one thing I +want to highlight to you now which will + + align:start position:0% +want to highlight to you now which will + + + align:start position:0% +want to highlight to you now which will +come up later is you know here I've + + align:start position:0% +come up later is you know here I've + + + align:start position:0% +come up later is you know here I've +simulated returns according to gaussing + + align:start position:0% +simulated returns according to gaussing + + + align:start position:0% +simulated returns according to gaussing +distributions with these means + + align:start position:0% +distributions with these means + + + align:start position:0% +distributions with these means +volatilities and + + align:start position:0% +volatilities and + + + align:start position:0% +volatilities and +correlations and in the + + align:start position:0% +correlations and in the + + + align:start position:0% +correlations and in the +the lower left panel I give the sample + + align:start position:0% +the lower left panel I give the sample + + + align:start position:0% +the lower left panel I give the sample +statistics basically the maximum + + align:start position:0% +statistics basically the maximum + + + align:start position:0% +statistics basically the maximum +likelihood estimates for all the + + align:start position:0% +likelihood estimates for all the + + + align:start position:0% +likelihood estimates for all the +parameters and what you'll see is that + + align:start position:0% +parameters and what you'll see is that + + + align:start position:0% +parameters and what you'll see is that +these sample estimates differ quite a + + align:start position:0% +these sample estimates differ quite a + + + align:start position:0% +these sample estimates differ quite a +bit from well they differ from the the + + align:start position:0% +bit from well they differ from the the + + + align:start position:0% +bit from well they differ from the the +theoretical parameters okay in this + + align:start position:0% +theoretical parameters okay in this + + + align:start position:0% +theoretical parameters okay in this +case uh the sample volatility is almost + + align:start position:0% +case uh the sample volatility is almost + + + align:start position:0% +case uh the sample volatility is almost +you know exactly on point for the first + + align:start position:0% +you know exactly on point for the first + + + align:start position:0% +you know exactly on point for the first +asset it's a bit below 0 287 for the + + align:start position:0% +asset it's a bit below 0 287 for the + + + align:start position:0% +asset it's a bit below 0 287 for the +second the sample mean is 0. 21 which is + + align:start position:0% +second the sample mean is 0. 21 which is + + + align:start position:0% +second the sample mean is 0. 21 which is +a bit high for the first and it's 321 + + align:start position:0% +a bit high for the first and it's 321 + + + align:start position:0% +a bit high for the first and it's 321 +which is also a bit high for the second + + align:start position:0% +which is also a bit high for the second + + + align:start position:0% +which is also a bit high for the second +let's just go back and look at a couple + + align:start position:0% +let's just go back and look at a couple + + + align:start position:0% +let's just go back and look at a couple +of the + + align:start position:0% +of the + + + align:start position:0% +of the +others because it can + + align:start position:0% + + + + align:start position:0% + +get okay well here's one + + align:start position:0% +get okay well here's one + + + align:start position:0% +get okay well here's one +where the sample means are 0.144 and + + align:start position:0% +where the sample means are 0.144 and + + + align:start position:0% +where the sample means are 0.144 and +343 um and so those are actually quite + + align:start position:0% +343 um and so those are actually quite + + + align:start position:0% +343 um and so those are actually quite +different from the the uh population + + align:start position:0% +different from the the uh population + + + align:start position:0% +different from the the uh population +parameters um and uh at least the the + + align:start position:0% +parameters um and uh at least the the + + + align:start position:0% +parameters um and uh at least the the +second asset has has a much higher + + align:start position:0% +second asset has has a much higher + + + align:start position:0% +second asset has has a much higher +sample mean so so it's important to note + + align:start position:0% +sample mean so so it's important to note + + + align:start position:0% +sample mean so so it's important to note +that uh sample estimates can have a + + align:start position:0% +that uh sample estimates can have a + + + align:start position:0% +that uh sample estimates can have a +certain amount of variability turns out + + align:start position:0% +certain amount of variability turns out + + + align:start position:0% +certain amount of variability turns out +that there's less variability in + + align:start position:0% +that there's less variability in + + + align:start position:0% +that there's less variability in +estimating covariances and correlations + + align:start position:0% +estimating covariances and correlations + + + align:start position:0% +estimating covariances and correlations +if the assumptions hold and greater uh + + align:start position:0% +if the assumptions hold and greater uh + + + align:start position:0% +if the assumptions hold and greater uh +variability in the sample means so uh at + + align:start position:0% +variability in the sample means so uh at + + + align:start position:0% +variability in the sample means so uh at +the end of the day we really need to be + + align:start position:0% +the end of the day we really need to be + + + align:start position:0% +the end of the day we really need to be +very sensitive to what estimates + + align:start position:0% +very sensitive to what estimates + + + align:start position:0% +very sensitive to what estimates +we use and how much uncertainty there is + + align:start position:0% +we use and how much uncertainty there is + + + align:start position:0% +we use and how much uncertainty there is +in + + align:start position:0% + + + + align:start position:0% + +those + + align:start position:0% +those + + + align:start position:0% +those +okay + + align:start position:0% +okay + + + align:start position:0% +okay +let's go back to the lecture notes now + + align:start position:0% + + + + align:start position:0% + +um okay + + align:start position:0% + + + + align:start position:0% + +view full screen all + + align:start position:0% + + + + align:start position:0% + +right all right so we've just gone + + align:start position:0% +right all right so we've just gone + + + align:start position:0% +right all right so we've just gone +through how we are evaluating different + + align:start position:0% +through how we are evaluating different + + + align:start position:0% +through how we are evaluating different +portfolios in terms of the the pair of + + align:start position:0% +portfolios in terms of the the pair of + + + align:start position:0% +portfolios in terms of the the pair of +the uh basically the mean of the + + align:start position:0% +the uh basically the mean of the + + + align:start position:0% +the uh basically the mean of the +portfolio and the volatility squared + + align:start position:0% +portfolio and the volatility squared + + + align:start position:0% +portfolio and the volatility squared +volatility of the portfolio higher + + align:start position:0% +volatility of the portfolio higher + + + align:start position:0% +volatility of the portfolio higher +expected returns are obviously desirable + + align:start position:0% +expected returns are obviously desirable + + + align:start position:0% +expected returns are obviously desirable +lower volatility is desirable and so + + align:start position:0% +lower volatility is desirable and so + + + align:start position:0% +lower volatility is desirable and so +what uh markwitz did was to uh basically + + align:start position:0% +what uh markwitz did was to uh basically + + + align:start position:0% +what uh markwitz did was to uh basically +pose this as a uh quadratic programming + + align:start position:0% +pose this as a uh quadratic programming + + + align:start position:0% +pose this as a uh quadratic programming +problem where what we want to do is + + align:start position:0% +problem where what we want to do is + + + align:start position:0% +problem where what we want to do is +minimize the + + align:start position:0% +minimize the + + + align:start position:0% +minimize the +volatility of the or the squared + + align:start position:0% +volatility of the or the squared + + + align:start position:0% +volatility of the or the squared +volatility of the portfolio subject to a + + align:start position:0% +volatility of the portfolio subject to a + + + align:start position:0% +volatility of the portfolio subject to a +constraint on the mean of the portfolio + + align:start position:0% +constraint on the mean of the portfolio + + + align:start position:0% +constraint on the mean of the portfolio +and considering that we're fully + + align:start position:0% +and considering that we're fully + + + align:start position:0% +and considering that we're fully +invested so this mathematical problem is + + align:start position:0% +invested so this mathematical problem is + + + align:start position:0% +invested so this mathematical problem is +you know a standard you know convex + + align:start position:0% +you know a standard you know convex + + + align:start position:0% +you know a standard you know convex +optimization problem a quadratic + + align:start position:0% +optimization problem a quadratic + + + align:start position:0% +optimization problem a quadratic +programming problem which is very simple + + align:start position:0% +programming problem which is very simple + + + align:start position:0% +programming problem which is very simple +and we solve it by defining a + + align:start position:0% +and we solve it by defining a + + + align:start position:0% +and we solve it by defining a +lran basically we take our objective + + align:start position:0% +lran basically we take our objective + + + align:start position:0% +lran basically we take our objective +function the + + align:start position:0% +function the + + + align:start position:0% +function the +volatility and we want to minimize that + + align:start position:0% +volatility and we want to minimize that + + + align:start position:0% +volatility and we want to minimize that +we're going to use a half Factor just to + + align:start position:0% +we're going to use a half Factor just to + + + align:start position:0% +we're going to use a half Factor just to +simplify the computations and then we + + align:start position:0% +simplify the computations and then we + + + align:start position:0% +simplify the computations and then we +add lran for the different constraints + + align:start position:0% +add lran for the different constraints + + + align:start position:0% +add lran for the different constraints +of the problem so we add Lambda 1 * + + align:start position:0% +of the problem so we add Lambda 1 * + + + align:start position:0% +of the problem so we add Lambda 1 * +Alpha us W Prime Alpha we want the mean + + align:start position:0% +Alpha us W Prime Alpha we want the mean + + + align:start position:0% +Alpha us W Prime Alpha we want the mean +return WP Prime Alpha to be constrained + + align:start position:0% +return WP Prime Alpha to be constrained + + + align:start position:0% +return WP Prime Alpha to be constrained +to equal Alpha not and we also want the + + align:start position:0% +to equal Alpha not and we also want the + + + align:start position:0% +to equal Alpha not and we also want the +sum of the weights W Prime 1M to equal + + align:start position:0% + + + + align:start position:0% + +1 and the first order conditions of the + + align:start position:0% +1 and the first order conditions of the + + + align:start position:0% +1 and the first order conditions of the +Gran basically give us those two + + align:start position:0% +Gran basically give us those two + + + align:start position:0% +Gran basically give us those two +constraints for differentiating with + + align:start position:0% +constraints for differentiating with + + + align:start position:0% +constraints for differentiating with +respect to Lambda one and + + align:start position:0% +respect to Lambda one and + + + align:start position:0% +respect to Lambda one and +lamb2 uh the the the initial first order + + align:start position:0% +lamb2 uh the the the initial first order + + + align:start position:0% +lamb2 uh the the the initial first order +condition with respect to the port folio + + align:start position:0% +condition with respect to the port folio + + + align:start position:0% +condition with respect to the port folio +weights uh basically allows us to solve + + align:start position:0% +weights uh basically allows us to solve + + + align:start position:0% +weights uh basically allows us to solve +for for those + + align:start position:0% + + + + align:start position:0% + +weights now this first order condition + + align:start position:0% +weights now this first order condition + + + align:start position:0% +weights now this first order condition +is going to solve our problem + + align:start position:0% +is going to solve our problem + + + align:start position:0% +is going to solve our problem +because this uh if we take the second + + align:start position:0% +because this uh if we take the second + + + align:start position:0% +because this uh if we take the second +order derivative of this + + align:start position:0% +order derivative of this + + + align:start position:0% +order derivative of this +lran it's going to + + align:start position:0% +lran it's going to + + + align:start position:0% +lran it's going to +be Sigma so um let me just point out + + align:start position:0% +be Sigma so um let me just point out + + + align:start position:0% +be Sigma so um let me just point out +that + + align:start position:0% +that + + + align:start position:0% +that +if we take d^2 L by DW DW Prime that's + + align:start position:0% +if we take d^2 L by DW DW Prime that's + + + align:start position:0% +if we take d^2 L by DW DW Prime that's +equal to our covariance Matrix + + align:start position:0% +equal to our covariance Matrix + + + align:start position:0% +equal to our covariance Matrix +Sigma and that is a positive definite or + + align:start position:0% +Sigma and that is a positive definite or + + + align:start position:0% +Sigma and that is a positive definite or +positive semi-finite Matrix so so we + + align:start position:0% +positive semi-finite Matrix so so we + + + align:start position:0% +positive semi-finite Matrix so so we +indeed are minimizing the problem so + + align:start position:0% +indeed are minimizing the problem so + + + align:start position:0% +indeed are minimizing the problem so +this is just a + + align:start position:0% +this is just a + + + align:start position:0% +this is just a +generalization of uh basically a a + + align:start position:0% +generalization of uh basically a a + + + align:start position:0% +generalization of uh basically a a +parabola in multi-dimensions and we're + + align:start position:0% +parabola in multi-dimensions and we're + + + align:start position:0% +parabola in multi-dimensions and we're +trying to to minimize that well what's + + align:start position:0% +trying to to minimize that well what's + + + align:start position:0% +trying to to minimize that well what's +the solution to + + align:start position:0% +the solution to + + + align:start position:0% +the solution to +this well first we can solve for w the + + align:start position:0% +this well first we can solve for w the + + + align:start position:0% +this well first we can solve for w the +weights in terms of Lambda 1 and Lambda + + align:start position:0% +weights in terms of Lambda 1 and Lambda + + + align:start position:0% +weights in terms of Lambda 1 and Lambda +2 so we take the first order the first + + align:start position:0% +2 so we take the first order the first + + + align:start position:0% +2 so we take the first order the first +equation of the first order conditions + + align:start position:0% +equation of the first order conditions + + + align:start position:0% +equation of the first order conditions +and basically premultiply by Sigma + + align:start position:0% +and basically premultiply by Sigma + + + align:start position:0% +and basically premultiply by Sigma +inverse + + align:start position:0% +inverse + + + align:start position:0% +inverse +across and we get W is equal to Lambda 1 + + align:start position:0% +across and we get W is equal to Lambda 1 + + + align:start position:0% +across and we get W is equal to Lambda 1 +Sigma inverse Alpha plus Lambda 2 Sigma + + align:start position:0% +Sigma inverse Alpha plus Lambda 2 Sigma + + + align:start position:0% +Sigma inverse Alpha plus Lambda 2 Sigma +inverse the unit Vector our Vector of + + align:start position:0% +inverse the unit Vector our Vector of + + + align:start position:0% +inverse the unit Vector our Vector of +units + + align:start position:0% +units + + + align:start position:0% +units +and then we can just solve for Lambda 1 + + align:start position:0% +and then we can just solve for Lambda 1 + + + align:start position:0% +and then we can just solve for Lambda 1 +and Lambda 2 by plugging this W + + align:start position:0% +and Lambda 2 by plugging this W + + + align:start position:0% +and Lambda 2 by plugging this W +KN solution into the second two + + align:start position:0% +KN solution into the second two + + + align:start position:0% +KN solution into the second two +equations and this these two equations + + align:start position:0% +equations and this these two equations + + + align:start position:0% +equations and this these two equations +for the second and third first order + + align:start position:0% +for the second and third first order + + + align:start position:0% +for the second and third first order +conditions is just a very simple linear + + align:start position:0% +conditions is just a very simple linear + + + align:start position:0% +conditions is just a very simple linear +set of linear + + align:start position:0% +set of linear + + + align:start position:0% +set of linear +equations um we basically + + align:start position:0% +equations um we basically + + + align:start position:0% +equations um we basically +have you know Alpha not alpha alpha not + + align:start position:0% +have you know Alpha not alpha alpha not + + + align:start position:0% +have you know Alpha not alpha alpha not +one is equal to + + align:start position:0% + + + + align:start position:0% + +Su Matrix times Lambda 1 Lambda 2 and + + align:start position:0% +Su Matrix times Lambda 1 Lambda 2 and + + + align:start position:0% +Su Matrix times Lambda 1 Lambda 2 and +that Matrix AB b c is given by Alpha + + align:start position:0% +that Matrix AB b c is given by Alpha + + + align:start position:0% +that Matrix AB b c is given by Alpha +Prime Sigma inverse Alpha for the a + + align:start position:0% +Prime Sigma inverse Alpha for the a + + + align:start position:0% +Prime Sigma inverse Alpha for the a +element and the B and C elements are + + align:start position:0% +element and the B and C elements are + + + align:start position:0% +element and the B and C elements are +those corresponding elements so this + + align:start position:0% +those corresponding elements so this + + + align:start position:0% +those corresponding elements so this +solves the + + align:start position:0% + + + + align:start position:0% + +problem and the variance of the optimal + + align:start position:0% +problem and the variance of the optimal + + + align:start position:0% +problem and the variance of the optimal +portfolio with a given return can + + align:start position:0% +portfolio with a given return can + + + align:start position:0% +portfolio with a given return can +also be solved by just substituting in + + align:start position:0% +also be solved by just substituting in + + + align:start position:0% +also be solved by just substituting in +these Solutions so we get that uh for a + + align:start position:0% +these Solutions so we get that uh for a + + + align:start position:0% +these Solutions so we get that uh for a +given Alpha not our Target + + align:start position:0% +given Alpha not our Target + + + align:start position:0% +given Alpha not our Target +return the squared volatility of that + + align:start position:0% +return the squared volatility of that + + + align:start position:0% +return the squared volatility of that +optimal + + align:start position:0% +optimal + + + align:start position:0% +optimal +portfolio is this has that form now + + align:start position:0% +portfolio is this has that form now + + + align:start position:0% +portfolio is this has that form now +what's that + + align:start position:0% +what's that + + + align:start position:0% +what's that +form it's essentially a parabola in + + align:start position:0% +form it's essentially a parabola in + + + align:start position:0% +form it's essentially a parabola in +Alpha + + align:start position:0% +Alpha + + + align:start position:0% +Alpha +notot Okay so when we're looking + + align:start position:0% +notot Okay so when we're looking + + + align:start position:0% +notot Okay so when we're looking +at when we're looking let's see is there + + align:start position:0% +at when we're looking let's see is there + + + align:start position:0% +at when we're looking let's see is there +an eraser here it is when we're looking + + align:start position:0% +an eraser here it is when we're looking + + + align:start position:0% +an eraser here it is when we're looking +at this + + align:start position:0% +at this + + + align:start position:0% +at this +graph here in the two-dimensional case + + align:start position:0% +graph here in the two-dimensional case + + + align:start position:0% +graph here in the two-dimensional case +then there's basically a + + align:start position:0% +then there's basically a + + + align:start position:0% +then there's basically a +parabola I can't draw parabas very well + + align:start position:0% +parabola I can't draw parabas very well + + + align:start position:0% +parabola I can't draw parabas very well +but there's a parabola between those two + + align:start position:0% +but there's a parabola between those two + + + align:start position:0% +but there's a parabola between those two +points that uh characterizes the thing + + align:start position:0% +points that uh characterizes the thing + + + align:start position:0% +points that uh characterizes the thing +and in multi-dimension with you know + + align:start position:0% +and in multi-dimension with you know + + + align:start position:0% +and in multi-dimension with you know +multiple assets it's just a you know a + + align:start position:0% +multiple assets it's just a you know a + + + align:start position:0% +multiple assets it's just a you know a +multivar extension of that + + align:start position:0% + + + + align:start position:0% + +um all right this particular problem uh + + align:start position:0% +um all right this particular problem uh + + + align:start position:0% +um all right this particular problem uh +can also be looked at in many in two + + align:start position:0% +can also be looked at in many in two + + + align:start position:0% +can also be looked at in many in two +other ways I before we're looking at + + align:start position:0% +other ways I before we're looking at + + + align:start position:0% +other ways I before we're looking at +minimizing the variant subject to a + + align:start position:0% +minimizing the variant subject to a + + + align:start position:0% +minimizing the variant subject to a +constraint on the expected return we can + + align:start position:0% +constraint on the expected return we can + + + align:start position:0% +constraint on the expected return we can +also say well let's maximize the return + + align:start position:0% +also say well let's maximize the return + + + align:start position:0% +also say well let's maximize the return +subject to a constraint on the + + align:start position:0% +subject to a constraint on the + + + align:start position:0% +subject to a constraint on the +volatility and uh + + align:start position:0% + + + + align:start position:0% + +that + + align:start position:0% +that + + + align:start position:0% +that +problem is basically has the same lran + + align:start position:0% +problem is basically has the same lran + + + align:start position:0% +problem is basically has the same lran +and we can also consider just + + align:start position:0% +and we can also consider just + + + align:start position:0% +and we can also consider just +maximizing a weighted average of the + + align:start position:0% + + + + align:start position:0% + +return and have a negative multiple on + + align:start position:0% +return and have a negative multiple on + + + align:start position:0% +return and have a negative multiple on +the variance and consider maximizing + + align:start position:0% +the variance and consider maximizing + + + align:start position:0% +the variance and consider maximizing +that + + align:start position:0% +that + + + align:start position:0% +that +expression um this turns out it to be + + align:start position:0% +expression um this turns out it to be + + + align:start position:0% +expression um this turns out it to be +the risk aversion + + align:start position:0% +the risk aversion + + + align:start position:0% +the risk aversion +optimization um where we basically are + + align:start position:0% + + + + align:start position:0% + +penalizing portfolios + + align:start position:0% +penalizing portfolios + + + align:start position:0% +penalizing portfolios +W for how + + align:start position:0% +W for how + + + align:start position:0% +W for how +much variance they have and the Lambda + + align:start position:0% +much variance they have and the Lambda + + + align:start position:0% +much variance they have and the Lambda +Factor tells us how much penalty to + + align:start position:0% +Factor tells us how much penalty to + + + align:start position:0% +Factor tells us how much penalty to +associate per variance + + align:start position:0% + + + + align:start position:0% + +unit and these are all equivalent uh + + align:start position:0% +unit and these are all equivalent uh + + + align:start position:0% +unit and these are all equivalent uh +problems uh being solved by the same + + align:start position:0% +problems uh being solved by the same + + + align:start position:0% +problems uh being solved by the same +lren and from these problems we can + + align:start position:0% +lren and from these problems we can + + + align:start position:0% +lren and from these problems we can +Define the efficient Frontier which is + + align:start position:0% +Define the efficient Frontier which is + + + align:start position:0% +Define the efficient Frontier which is +the collection of all possible + + align:start position:0% +the collection of all possible + + + align:start position:0% +the collection of all possible +solutions where we + + align:start position:0% +solutions where we + + + align:start position:0% +solutions where we +range the target return amongst values + + align:start position:0% +range the target return amongst values + + + align:start position:0% +range the target return amongst values +that are feasible and the volatility + + align:start position:0% +that are feasible and the volatility + + + align:start position:0% +that are feasible and the volatility +amongst values that are feasible as + + align:start position:0% +amongst values that are feasible as + + + align:start position:0% +amongst values that are feasible as +well so the efficient Frontier will just + + align:start position:0% +well so the efficient Frontier will just + + + align:start position:0% +well so the efficient Frontier will just +Trace these + + align:start position:0% +Trace these + + + align:start position:0% +Trace these +out um and in our two variable case our + + align:start position:0% +out um and in our two variable case our + + + align:start position:0% +out um and in our two variable case our +two asset + + align:start position:0% + + + + align:start position:0% + +case okay we have Sigma and Alpha we + + align:start position:0% +case okay we have Sigma and Alpha we + + + align:start position:0% +case okay we have Sigma and Alpha we +have two assets is basically a parabola + + align:start position:0% +have two assets is basically a parabola + + + align:start position:0% +have two assets is basically a parabola +like + + align:start position:0% +like + + + align:start position:0% +like +that if we have another two assets that + + align:start position:0% +that if we have another two assets that + + + align:start position:0% +that if we have another two assets that +we're investing + + align:start position:0% + + + + align:start position:0% + +with then if we consider the two asset + + align:start position:0% +with then if we consider the two asset + + + align:start position:0% +with then if we consider the two asset +combinate portfolios of just these two + + align:start position:0% +combinate portfolios of just these two + + + align:start position:0% +combinate portfolios of just these two +assets there's basically another + + align:start position:0% +assets there's basically another + + + align:start position:0% +assets there's basically another +Parabola there and as we consider + + align:start position:0% +Parabola there and as we consider + + + align:start position:0% +Parabola there and as we consider +different + + align:start position:0% +different + + + align:start position:0% +different +other Assets in the mix we basically get + + align:start position:0% +other Assets in the mix we basically get + + + align:start position:0% +other Assets in the mix we basically get +all these parabas of two asset + + align:start position:0% +all these parabas of two asset + + + align:start position:0% +all these parabas of two asset +portfolios and then combinations of + + align:start position:0% +portfolios and then combinations of + + + align:start position:0% +portfolios and then combinations of +those two asset portfolios gives us + + align:start position:0% +those two asset portfolios gives us + + + align:start position:0% +those two asset portfolios gives us +our uh feasible set and so at the end of + + align:start position:0% +our uh feasible set and so at the end of + + + align:start position:0% +our uh feasible set and so at the end of +the day we basically have a convex + + align:start position:0% +the day we basically have a convex + + + align:start position:0% +the day we basically have a convex +set of all Fe feasible assets which uh + + align:start position:0% +set of all Fe feasible assets which uh + + + align:start position:0% +set of all Fe feasible assets which uh +Define the efficient Frontier and the + + align:start position:0% +Define the efficient Frontier and the + + + align:start position:0% +Define the efficient Frontier and the +efficient Frontier is always going to + + align:start position:0% +efficient Frontier is always going to + + + align:start position:0% +efficient Frontier is always going to +be basically the top side of that + + align:start position:0% +be basically the top side of that + + + align:start position:0% +be basically the top side of that +curve + + align:start position:0% + + + + align:start position:0% + +well + + align:start position:0% + + + + align:start position:0% + +with let's see the next topic considers + + align:start position:0% +with let's see the next topic considers + + + align:start position:0% +with let's see the next topic considers +adding basically a risk-free asset to + + align:start position:0% +adding basically a risk-free asset to + + + align:start position:0% +adding basically a risk-free asset to +invest in the problem as it's been + + align:start position:0% +invest in the problem as it's been + + + align:start position:0% +invest in the problem as it's been +stated so far says we want to be fully + + align:start position:0% +stated so far says we want to be fully + + + align:start position:0% +stated so far says we want to be fully +invested across our M assets and what + + align:start position:0% +invested across our M assets and what + + + align:start position:0% +invested across our M assets and what +are the optimal + + align:start position:0% +are the optimal + + + align:start position:0% +are the optimal +portfolios well what if + + align:start position:0% +portfolios well what if + + + align:start position:0% +portfolios well what if +we don't what if we want to invest some + + align:start position:0% +we don't what if we want to invest some + + + align:start position:0% +we don't what if we want to invest some +of our money our Capital just in cash or + + align:start position:0% +of our money our Capital just in cash or + + + align:start position:0% +of our money our Capital just in cash or +not invest our full capital and and + + align:start position:0% +not invest our full capital and and + + + align:start position:0% +not invest our full capital and and +invest the rest in in the in the + + align:start position:0% +invest the rest in in the in the + + + align:start position:0% +invest the rest in in the in the +portfolios so + + align:start position:0% +portfolios so + + + align:start position:0% +portfolios so +um if we consider adding a risk-free + + align:start position:0% +um if we consider adding a risk-free + + + align:start position:0% +um if we consider adding a risk-free +asset uh then this is an asset we'll + + align:start position:0% +asset uh then this is an asset we'll + + + align:start position:0% +asset uh then this is an asset we'll +call it the zeroth + + align:start position:0% +call it the zeroth + + + align:start position:0% +call it the zeroth +asset it has say some expected return + + align:start position:0% +asset it has say some expected return + + + align:start position:0% +asset it has say some expected return +are not it's risk-free so that's a + + align:start position:0% +are not it's risk-free so that's a + + + align:start position:0% +are not it's risk-free so that's a +constant it has zero + + align:start position:0% +constant it has zero + + + align:start position:0% +constant it has zero +variance and if we're investing as well + + align:start position:0% +variance and if we're investing as well + + + align:start position:0% +variance and if we're investing as well +in that possible risky asset then we can + + align:start position:0% +in that possible risky asset then we can + + + align:start position:0% +in that possible risky asset then we can +basically consider investing W weights + + align:start position:0% +basically consider investing W weights + + + align:start position:0% +basically consider investing W weights +in the risky assets and one minus W + + align:start position:0% +in the risky assets and one minus W + + + align:start position:0% +in the risky assets and one minus W +Times the unit Vector in in in the + + align:start position:0% +Times the unit Vector in in in the + + + align:start position:0% +Times the unit Vector in in in the +risk-free + + align:start position:0% +risk-free + + + align:start position:0% +risk-free +asset um and let's see I want to draw + + align:start position:0% +asset um and let's see I want to draw + + + align:start position:0% +asset um and let's see I want to draw +this graph + + align:start position:0% + + + + align:start position:0% + +here let's + + align:start position:0% + + + + align:start position:0% + +see okay + + align:start position:0% +see okay + + + align:start position:0% +see okay +um okay suppose we have two assets where + + align:start position:0% +um okay suppose we have two assets where + + + align:start position:0% +um okay suppose we have two assets where +this is the efficient + + align:start position:0% +this is the efficient + + + align:start position:0% +this is the efficient +set and we consider now allowing for for + + align:start position:0% +set and we consider now allowing for for + + + align:start position:0% +set and we consider now allowing for for +a risk-free asset to be invested in as + + align:start position:0% +a risk-free asset to be invested in as + + + align:start position:0% +a risk-free asset to be invested in as +well well that risk-free asset is + + align:start position:0% +well well that risk-free asset is + + + align:start position:0% +well well that risk-free asset is +basically this point + + align:start position:0% + + + + align:start position:0% + +here and it has mean r KN and variance + + align:start position:0% +here and it has mean r KN and variance + + + align:start position:0% +here and it has mean r KN and variance +zero now if we combine this asset with + + align:start position:0% +zero now if we combine this asset with + + + align:start position:0% +zero now if we combine this asset with +any of these + + align:start position:0% + + + + align:start position:0% + +portfolios what's the feasible set going + + align:start position:0% +portfolios what's the feasible set going + + + align:start position:0% +portfolios what's the feasible set going +to be + + align:start position:0% +to be + + + align:start position:0% +to be +well we can + + align:start position:0% + + + + align:start position:0% + +basically invest in some money in the + + align:start position:0% +basically invest in some money in the + + + align:start position:0% +basically invest in some money in the +risk-free asset and some in asset + + align:start position:0% + + + + align:start position:0% + +two so we can get any point along this + + align:start position:0% +two so we can get any point along this + + + align:start position:0% +two so we can get any point along this +line basically if we invest in the + + align:start position:0% +line basically if we invest in the + + + align:start position:0% +line basically if we invest in the +risk-free + + align:start position:0% +risk-free + + + align:start position:0% +risk-free +asset um if we invest uh some fraction + + align:start position:0% +asset um if we invest uh some fraction + + + align:start position:0% +asset um if we invest uh some fraction +in asset two and the remainder in the + + align:start position:0% +in asset two and the remainder in the + + + align:start position:0% +in asset two and the remainder in the +risk-free asset then our expected return + + align:start position:0% +risk-free asset then our expected return + + + align:start position:0% +risk-free asset then our expected return +is the + + align:start position:0% +is the + + + align:start position:0% +is the +linear U line between R KN and Alpha + + align:start position:0% +linear U line between R KN and Alpha + + + align:start position:0% +linear U line between R KN and Alpha +2 and the volatility of a weighted + + align:start position:0% +2 and the volatility of a weighted + + + align:start position:0% +2 and the volatility of a weighted +average or of a fraction of asset + + align:start position:0% +average or of a fraction of asset + + + align:start position:0% +average or of a fraction of asset +to uh is has volatility given by + + align:start position:0% +to uh is has volatility given by + + + align:start position:0% +to uh is has volatility given by +whatever that weight is times the + + align:start position:0% +whatever that weight is times the + + + align:start position:0% +whatever that weight is times the +volatility so um so this point here + + align:start position:0% +volatility so um so this point here + + + align:start position:0% +volatility so um so this point here +corresponds to + + align:start position:0% +corresponds to + + + align:start position:0% +corresponds to +uh say w * Sigma + + align:start position:0% +uh say w * Sigma + + + align:start position:0% +uh say w * Sigma +2 for its + + align:start position:0% +2 for its + + + align:start position:0% +2 for its +volatility + + align:start position:0% +volatility + + + align:start position:0% +volatility +and R KN plus W * Alpha 2 minus + + align:start position:0% + + + + align:start position:0% + +r now the dramatic thing is that U we + + align:start position:0% +r now the dramatic thing is that U we + + + align:start position:0% +r now the dramatic thing is that U we +actually are able to achieve + + align:start position:0% +actually are able to achieve + + + align:start position:0% +actually are able to achieve +an improvement + + align:start position:0% +an improvement + + + align:start position:0% +an improvement +over points on the efficient + + align:start position:0% +over points on the efficient + + + align:start position:0% +over points on the efficient +Frontier such as say the minimum + + align:start position:0% +Frontier such as say the minimum + + + align:start position:0% +Frontier such as say the minimum +variance + + align:start position:0% +variance + + + align:start position:0% +variance +portfolio um and if we consider the + + align:start position:0% +portfolio um and if we consider the + + + align:start position:0% +portfolio um and if we consider the +fraction up here we actually have a + + align:start position:0% +fraction up here we actually have a + + + align:start position:0% +fraction up here we actually have a +higher + + align:start position:0% +higher + + + align:start position:0% +higher +return and a lower variance than the + + align:start position:0% +return and a lower variance than the + + + align:start position:0% +return and a lower variance than the +minimum variance portfolio that we + + align:start position:0% +minimum variance portfolio that we + + + align:start position:0% +minimum variance portfolio that we +considered + + align:start position:0% +considered + + + align:start position:0% +considered +before and so investing in the risk free + + align:start position:0% +before and so investing in the risk free + + + align:start position:0% +before and so investing in the risk free +asset does sort of enlarge our + + align:start position:0% +asset does sort of enlarge our + + + align:start position:0% +asset does sort of enlarge our +opportunity space quite dramatically and + + align:start position:0% +opportunity space quite dramatically and + + + align:start position:0% +opportunity space quite dramatically and +uh there are some very special results + + align:start position:0% +uh there are some very special results + + + align:start position:0% +uh there are some very special results +that come from this + + align:start position:0% + + + + align:start position:0% + +um so let's go through the mathematics + + align:start position:0% +um so let's go through the mathematics + + + align:start position:0% +um so let's go through the mathematics +for solving this problem and in the + + align:start position:0% +for solving this problem and in the + + + align:start position:0% +for solving this problem and in the +lecture notes I'm going to go over this + + align:start position:0% +lecture notes I'm going to go over this + + + align:start position:0% +lecture notes I'm going to go over this +pretty + + align:start position:0% +pretty + + + align:start position:0% +pretty +quickly I it's really when you go + + align:start position:0% +quickly I it's really when you go + + + align:start position:0% +quickly I it's really when you go +through it slowly you'll say oh this is + + align:start position:0% +through it slowly you'll say oh this is + + + align:start position:0% +through it slowly you'll say oh this is +very straightforward logical + + align:start position:0% +very straightforward logical + + + align:start position:0% +very straightforward logical +um so we're basically going to minimize + + align:start position:0% +um so we're basically going to minimize + + + align:start position:0% +um so we're basically going to minimize +the volatility subject to the constraint + + align:start position:0% +the volatility subject to the constraint + + + align:start position:0% +the volatility subject to the constraint +that the return is equal to Alpha not we + + align:start position:0% +that the return is equal to Alpha not we + + + align:start position:0% +that the return is equal to Alpha not we +Define the + + align:start position:0% +Define the + + + align:start position:0% +Define the +lonian and do the first order conditions + + align:start position:0% +lonian and do the first order conditions + + + align:start position:0% +lonian and do the first order conditions +solve those and if we solve those we get + + align:start position:0% +solve those and if we solve those we get + + + align:start position:0% +solve those and if we solve those we get +basically uh Lambda 1 has this nice form + + align:start position:0% +basically uh Lambda 1 has this nice form + + + align:start position:0% +basically uh Lambda 1 has this nice form +here and this is obtained by just very + + align:start position:0% +here and this is obtained by just very + + + align:start position:0% +here and this is obtained by just very +simple equation solving of those two + + align:start position:0% +simple equation solving of those two + + + align:start position:0% +simple equation solving of those two +first order + + align:start position:0% + + + + align:start position:0% + +conditions and if we have M assets + + align:start position:0% +conditions and if we have M assets + + + align:start position:0% +conditions and if we have M assets +uh available um when we look at the + + align:start position:0% +uh available um when we look at the + + + align:start position:0% +uh available um when we look at the +solution + + align:start position:0% + + + + align:start position:0% + +then we get an optimal + + align:start position:0% +then we get an optimal + + + align:start position:0% +then we get an optimal +portfolio that has a w Vector given by + + align:start position:0% +portfolio that has a w Vector given by + + + align:start position:0% +portfolio that has a w Vector given by +this solution and Lambda one given by + + align:start position:0% +this solution and Lambda one given by + + + align:start position:0% +this solution and Lambda one given by +this solution now W is the proportion uh + + align:start position:0% +this solution now W is the proportion uh + + + align:start position:0% +this solution now W is the proportion uh +is the allocation to the risky + + align:start position:0% +is the allocation to the risky + + + align:start position:0% +is the allocation to the risky +assets what is what + + align:start position:0% +assets what is what + + + align:start position:0% +assets what is what +varies depending on our Target return + + align:start position:0% +varies depending on our Target return + + + align:start position:0% +varies depending on our Target return +Alpha KN is simply + + align:start position:0% +Alpha KN is simply + + + align:start position:0% +Alpha KN is simply +this uh Lambda 1 uh lran multiplier + + align:start position:0% +this uh Lambda 1 uh lran multiplier + + + align:start position:0% +this uh Lambda 1 uh lran multiplier +basically Alpha not our Target + + align:start position:0% +basically Alpha not our Target + + + align:start position:0% +basically Alpha not our Target +return only affects the value of Lambda + + align:start position:0% +return only affects the value of Lambda + + + align:start position:0% +return only affects the value of Lambda +1 and our weights across the risky + + align:start position:0% +1 and our weights across the risky + + + align:start position:0% +1 and our weights across the risky +assets is a simple multiple of of a + + align:start position:0% +assets is a simple multiple of of a + + + align:start position:0% +assets is a simple multiple of of a +fixed + + align:start position:0% +fixed + + + align:start position:0% +fixed +Vector of relative + + align:start position:0% +Vector of relative + + + align:start position:0% +Vector of relative +weights and and this fixed Vector of + + align:start position:0% +weights and and this fixed Vector of + + + align:start position:0% +weights and and this fixed Vector of +relative + + align:start position:0% +relative + + + align:start position:0% +relative +weights is the inverse of the covariance + + align:start position:0% +weights is the inverse of the covariance + + + align:start position:0% +weights is the inverse of the covariance +Matrix across the assets times Alpha + + align:start position:0% +Matrix across the assets times Alpha + + + align:start position:0% +Matrix across the assets times Alpha +minus 1 M + + align:start position:0% +minus 1 M + + + align:start position:0% +minus 1 M +r0 and uh so what we have is a + + align:start position:0% +r0 and uh so what we have is a + + + align:start position:0% +r0 and uh so what we have is a +portfolio + + align:start position:0% +portfolio + + + align:start position:0% +portfolio +that + + align:start position:0% +that + + + align:start position:0% +that +uh basically in invests in the risky + + align:start position:0% +uh basically in invests in the risky + + + align:start position:0% +uh basically in invests in the risky +Assets in the same way the only thing + + align:start position:0% +Assets in the same way the only thing + + + align:start position:0% +Assets in the same way the only thing +that differs is how much weight we give + + align:start position:0% +that differs is how much weight we give + + + align:start position:0% +that differs is how much weight we give +to that particular portfolio as we + + align:start position:0% +to that particular portfolio as we + + + align:start position:0% +to that particular portfolio as we +increase Lambda 1 then we give more + + align:start position:0% +increase Lambda 1 then we give more + + + align:start position:0% +increase Lambda 1 then we give more +allocation to this fixed Vector of + + align:start position:0% +allocation to this fixed Vector of + + + align:start position:0% +allocation to this fixed Vector of +weight so we invest proportionally in + + align:start position:0% +weight so we invest proportionally in + + + align:start position:0% +weight so we invest proportionally in +the assets and we just scale how much + + align:start position:0% +the assets and we just scale how much + + + align:start position:0% +the assets and we just scale how much +that uh overall factor is uh to achieve + + align:start position:0% +that uh overall factor is uh to achieve + + + align:start position:0% +that uh overall factor is uh to achieve +different levels of + + align:start position:0% + + + + align:start position:0% + +return okay we can get nice closed form + + align:start position:0% +return okay we can get nice closed form + + + align:start position:0% +return okay we can get nice closed form +expressions for the portfolio + + align:start position:0% +expressions for the portfolio + + + align:start position:0% +expressions for the portfolio +variance um just you know as an + + align:start position:0% +variance um just you know as an + + + align:start position:0% +variance um just you know as an +extension of the sort of two asset case + + align:start position:0% +extension of the sort of two asset case + + + align:start position:0% +extension of the sort of two asset case +basically the portfolio variance is a + + align:start position:0% +basically the portfolio variance is a + + + align:start position:0% +basically the portfolio variance is a +parabola in the Target + + align:start position:0% +parabola in the Target + + + align:start position:0% +parabola in the Target +return um and so as we increase our + + align:start position:0% +return um and so as we increase our + + + align:start position:0% +return um and so as we increase our +Target return we have to increase our + + align:start position:0% +Target return we have to increase our + + + align:start position:0% +Target return we have to increase our +portfolio variability there's there is + + align:start position:0% +portfolio variability there's there is + + + align:start position:0% +portfolio variability there's there is +that tradeoff with these optimal + + align:start position:0% +that tradeoff with these optimal + + + align:start position:0% +that tradeoff with these optimal +portfolio + + align:start position:0% + + + + align:start position:0% + +and if we consider the fully invested + + align:start position:0% +and if we consider the fully invested + + + align:start position:0% +and if we consider the fully invested +optimal + + align:start position:0% +optimal + + + align:start position:0% +optimal +portfolio well + + align:start position:0% +portfolio well + + + align:start position:0% +portfolio well +um the fully invested Mark uh uh the + + align:start position:0% +um the fully invested Mark uh uh the + + + align:start position:0% +um the fully invested Mark uh uh the +fully invested portfolio invests nothing + + align:start position:0% +fully invested portfolio invests nothing + + + align:start position:0% +fully invested portfolio invests nothing +in cash invests everything in the risky + + align:start position:0% +in cash invests everything in the risky + + + align:start position:0% +in cash invests everything in the risky +assets um we actually are going to call + + align:start position:0% +assets um we actually are going to call + + + align:start position:0% +assets um we actually are going to call +that the market + + align:start position:0% +that the market + + + align:start position:0% +that the market +portfolio um um and the Expressions here + + align:start position:0% +portfolio um um and the Expressions here + + + align:start position:0% +portfolio um um and the Expressions here +give us the weights for that uh Market + + align:start position:0% +give us the weights for that uh Market + + + align:start position:0% +give us the weights for that uh Market +portfolio and + + align:start position:0% +portfolio and + + + align:start position:0% +portfolio and +uh and this may look a little + + align:start position:0% +uh and this may look a little + + + align:start position:0% +uh and this may look a little +complicated um in terms of the + + align:start position:0% +complicated um in terms of the + + + align:start position:0% +complicated um in terms of the +Expressions but it's actually simple + + align:start position:0% +Expressions but it's actually simple + + + align:start position:0% +Expressions but it's actually simple +closed form expressions + + align:start position:0% +closed form expressions + + + align:start position:0% +closed form expressions +for uh the expected return and the + + align:start position:0% +for uh the expected return and the + + + align:start position:0% +for uh the expected return and the +variance of the market + + align:start position:0% +variance of the market + + + align:start position:0% +variance of the market +portfolio um and and what's + + align:start position:0% +portfolio um and and what's + + + align:start position:0% +portfolio um and and what's +happening with this is We + + align:start position:0% + + + + align:start position:0% + +have basically for the risky assets we + + align:start position:0% +have basically for the risky assets we + + + align:start position:0% +have basically for the risky assets we +have some + + align:start position:0% +have some + + + align:start position:0% +have some +efficient uh or set of feasible + + align:start position:0% +efficient uh or set of feasible + + + align:start position:0% +efficient uh or set of feasible +portfolios which is all in this range + + align:start position:0% +portfolios which is all in this range + + + align:start position:0% +portfolios which is all in this range +and + + align:start position:0% +and + + + align:start position:0% +and +then with our risky + + align:start position:0% +then with our risky + + + align:start position:0% +then with our risky +asset we could be investing here and so + + align:start position:0% +asset we could be investing here and so + + + align:start position:0% +asset we could be investing here and so +the optimal + + align:start position:0% +the optimal + + + align:start position:0% +the optimal +portfolio the optimal portfolio is in in + + align:start position:0% +portfolio the optimal portfolio is in in + + + align:start position:0% +portfolio the optimal portfolio is in in +in the case where we can invest in in + + align:start position:0% +in the case where we can invest in in + + + align:start position:0% +in the case where we can invest in in +the uh risk-free + + align:start position:0% +the uh risk-free + + + align:start position:0% +the uh risk-free +asset will basically correspond to sort + + align:start position:0% +asset will basically correspond to sort + + + align:start position:0% +asset will basically correspond to sort +of maximizing the return the mean return + + align:start position:0% +of maximizing the return the mean return + + + align:start position:0% +of maximizing the return the mean return +for across all portfolio so it's + + align:start position:0% +for across all portfolio so it's + + + align:start position:0% +for across all portfolio so it's +actually going to correspond to the + + align:start position:0% +actually going to correspond to the + + + align:start position:0% +actually going to correspond to the +simple tangent + + align:start position:0% +simple tangent + + + align:start position:0% +simple tangent +line which + + align:start position:0% +line which + + + align:start position:0% +line which +basically + + align:start position:0% + + + + align:start position:0% + +crosses the uh Market + + align:start position:0% +crosses the uh Market + + + align:start position:0% +crosses the uh Market +portfolio which is the fully invested + + align:start position:0% + + + + align:start position:0% + +portfolio Okay now + + align:start position:0% +portfolio Okay now + + + align:start position:0% +portfolio Okay now +um this structure of the problem is is + + align:start position:0% +um this structure of the problem is is + + + align:start position:0% +um this structure of the problem is is +actually + + align:start position:0% +actually + + + align:start position:0% +actually +incredibly powerful and there's an + + align:start position:0% +incredibly powerful and there's an + + + align:start position:0% +incredibly powerful and there's an +important paper by Tobin + + align:start position:0% +important paper by Tobin + + + align:start position:0% +important paper by Tobin +which uh states that basically every + + align:start position:0% +which uh states that basically every + + + align:start position:0% +which uh states that basically every +portfolio is going to under these + + align:start position:0% +portfolio is going to under these + + + align:start position:0% +portfolio is going to under these +assumptions for the investment uh + + align:start position:0% +assumptions for the investment uh + + + align:start position:0% +assumptions for the investment uh +problem every optimal portfolio invests + + align:start position:0% +problem every optimal portfolio invests + + + align:start position:0% +problem every optimal portfolio invests +in a combination of the risk-free asset + + align:start position:0% +in a combination of the risk-free asset + + + align:start position:0% +in a combination of the risk-free asset +and the market + + align:start position:0% +and the market + + + align:start position:0% +and the market +portfolio + + align:start position:0% +portfolio + + + align:start position:0% +portfolio +so regardless of what of how you want of + + align:start position:0% +so regardless of what of how you want of + + + align:start position:0% +so regardless of what of how you want of +regardless of uh how much risk you want + + align:start position:0% +regardless of uh how much risk you want + + + align:start position:0% +regardless of uh how much risk you want +to take the optimal portfolio + + align:start position:0% +to take the optimal portfolio + + + align:start position:0% +to take the optimal portfolio +is essentially the same it just depends + + align:start position:0% +is essentially the same it just depends + + + align:start position:0% +is essentially the same it just depends +on how much Capital you're going to put + + align:start position:0% +on how much Capital you're going to put + + + align:start position:0% +on how much Capital you're going to put +into that optimal + + align:start position:0% +into that optimal + + + align:start position:0% +into that optimal +portfolio and so uh all the optimal + + align:start position:0% +portfolio and so uh all the optimal + + + align:start position:0% +portfolio and so uh all the optimal +portfolios will invest in the same risky + + align:start position:0% +portfolios will invest in the same risky + + + align:start position:0% +portfolios will invest in the same risky +assets as the market portfolio and the + + align:start position:0% +assets as the market portfolio and the + + + align:start position:0% +assets as the market portfolio and the +same proportions and the only difference + + align:start position:0% +same proportions and the only difference + + + align:start position:0% +same proportions and the only difference +is is their total + + align:start position:0% +is is their total + + + align:start position:0% +is is their total +weight now plugging in the expressions + + align:start position:0% +weight now plugging in the expressions + + + align:start position:0% +weight now plugging in the expressions +for the different uh lrange multipliers + + align:start position:0% +for the different uh lrange multipliers + + + align:start position:0% +for the different uh lrange multipliers +for a given + + align:start position:0% +for a given + + + align:start position:0% +for a given +portfolio p with + + align:start position:0% +portfolio p with + + + align:start position:0% +portfolio p with +return and we get that expression so let + + align:start position:0% +return and we get that expression so let + + + align:start position:0% +return and we get that expression so let +me just summarize that so suppose we + + align:start position:0% +me just summarize that so suppose we + + + align:start position:0% +me just summarize that so suppose we +want the portfolio P such that the + + align:start position:0% +want the portfolio P such that the + + + align:start position:0% +want the portfolio P such that the +expectation of RP is equal to Alpha + + align:start position:0% + + + + align:start position:0% + +not + + align:start position:0% + + + + align:start position:0% + +then this uh this portfolio RP + + align:start position:0% +then this uh this portfolio RP + + + align:start position:0% +then this uh this portfolio RP +is going to + + align:start position:0% + + + + align:start position:0% + +equal it's going to equal um + + align:start position:0% + + + + align:start position:0% + +basically what uh it's going to invest + + align:start position:0% +basically what uh it's going to invest + + + align:start position:0% +basically what uh it's going to invest +in the risk-free asset with one minus + + align:start position:0% +in the risk-free asset with one minus + + + align:start position:0% +in the risk-free asset with one minus +one transpose + + align:start position:0% + + + + align:start position:0% + +WM + + align:start position:0% + + + + align:start position:0% + +plus WM transpose + + align:start position:0% + + + + align:start position:0% + +I'm sorry WM + + align:start position:0% +I'm sorry WM + + + align:start position:0% +I'm sorry WM +times the return of the + + align:start position:0% +times the return of the + + + align:start position:0% +times the return of the +market and uh the actual weights are + + align:start position:0% +market and uh the actual weights are + + + align:start position:0% +market and uh the actual weights are +given by this expression here + + align:start position:0% +given by this expression here + + + align:start position:0% +given by this expression here +which gives + + align:start position:0% + + + + align:start position:0% + +us okay the expression that I'm just + + align:start position:0% +us okay the expression that I'm just + + + align:start position:0% +us okay the expression that I'm just +writing up from the + + align:start position:0% + + + + align:start position:0% + +board we have that the expected return + + align:start position:0% +board we have that the expected return + + + align:start position:0% +board we have that the expected return +is R plus WM * the market return minus r + + align:start position:0% +is R plus WM * the market return minus r + + + align:start position:0% +is R plus WM * the market return minus r +and the + + align:start position:0% +and the + + + align:start position:0% +and the +volatility Sigma 2 p is simply the + + align:start position:0% +volatility Sigma 2 p is simply the + + + align:start position:0% +volatility Sigma 2 p is simply the +square of the weight in the market times + + align:start position:0% +square of the weight in the market times + + + align:start position:0% +square of the weight in the market times +the market + + align:start position:0% + + + + align:start position:0% + +volatility okay this uh leads to the + + align:start position:0% +volatility okay this uh leads to the + + + align:start position:0% +volatility okay this uh leads to the +definition of basically the Capital + + align:start position:0% +definition of basically the Capital + + + align:start position:0% +definition of basically the Capital +Market + + align:start position:0% +Market + + + align:start position:0% +Market +line which + + align:start position:0% + + + + align:start position:0% + +is which is essentially this line here + + align:start position:0% +is which is essentially this line here + + + align:start position:0% +is which is essentially this line here +this is our Capital Market line + + align:start position:0% +this is our Capital Market line + + + align:start position:0% +this is our Capital Market line +for the portfolio + + align:start position:0% +for the portfolio + + + align:start position:0% +for the portfolio +optimization and the structure of this + + align:start position:0% +optimization and the structure of this + + + align:start position:0% +optimization and the structure of this +line is such that this point for the + + align:start position:0% +line is such that this point for the + + + align:start position:0% +line is such that this point for the +market + + align:start position:0% +market + + + align:start position:0% +market +portfolio that has volatility given by + + align:start position:0% +portfolio that has volatility given by + + + align:start position:0% +portfolio that has volatility given by +the market portfolios volatility Sigma M + + align:start position:0% +the market portfolios volatility Sigma M + + + align:start position:0% +the market portfolios volatility Sigma M +and the return on the market alpha M or + + align:start position:0% +and the return on the market alpha M or + + + align:start position:0% +and the return on the market alpha M or +expected value of M of + + align:start position:0% +expected value of M of + + + align:start position:0% +expected value of M of +RM + + align:start position:0% +RM + + + align:start position:0% +RM +and the slope of this + + align:start position:0% +and the slope of this + + + align:start position:0% +and the slope of this +line is given + + align:start position:0% +line is given + + + align:start position:0% +line is given +by Alpha + + align:start position:0% +by Alpha + + + align:start position:0% +by Alpha +M minus r KN over Sigma + + align:start position:0% +M minus r KN over Sigma + + + align:start position:0% +M minus r KN over Sigma +M and points along the line are given by + + align:start position:0% +M and points along the line are given by + + + align:start position:0% +M and points along the line are given by +R + + align:start position:0% +R + + + align:start position:0% +R +KN Plus + + align:start position:0% + + + + align:start position:0% + +Sigma P times this Factor so this is the + + align:start position:0% +Sigma P times this Factor so this is the + + + align:start position:0% +Sigma P times this Factor so this is the +uh expected value of + + align:start position:0% +uh expected value of + + + align:start position:0% +uh expected value of +RP is any optimal portfolio has return + + align:start position:0% +RP is any optimal portfolio has return + + + align:start position:0% +RP is any optimal portfolio has return +equal to the risk-free + + align:start position:0% +equal to the risk-free + + + align:start position:0% +equal to the risk-free +rate plus a + + align:start position:0% +rate plus a + + + align:start position:0% +rate plus a +multiple of the return per risk of the + + align:start position:0% +multiple of the return per risk of the + + + align:start position:0% +multiple of the return per risk of the +market + + align:start position:0% + + + + align:start position:0% + +portfolio This this term here + + align:start position:0% + + + + align:start position:0% + +is called the price of Market + + align:start position:0% +is called the price of Market + + + align:start position:0% +is called the price of Market +risk yes is that the same as the sharp + + align:start position:0% +risk yes is that the same as the sharp + + + align:start position:0% +risk yes is that the same as the sharp +ratio I it's + + align:start position:0% +ratio I it's + + + align:start position:0% +ratio I it's +uh close to the sharp ratio and the + + align:start position:0% +uh close to the sharp ratio and the + + + align:start position:0% +uh close to the sharp ratio and the +sharp ratio is + + align:start position:0% +sharp ratio is + + + align:start position:0% +sharp ratio is +is yes and this is is the sharp ratio + + align:start position:0% +is yes and this is is the sharp ratio + + + align:start position:0% +is yes and this is is the sharp ratio +for the uh for the market portfolio + + align:start position:0% +for the uh for the market portfolio + + + align:start position:0% +for the uh for the market portfolio +yeah and so um if we want to invest in + + align:start position:0% +yeah and so um if we want to invest in + + + align:start position:0% +yeah and so um if we want to invest in +uh in the market our decision is reduced + + align:start position:0% +uh in the market our decision is reduced + + + align:start position:0% +uh in the market our decision is reduced +then to how much risk are we willing to + + align:start position:0% +then to how much risk are we willing to + + + align:start position:0% +then to how much risk are we willing to +take and the compensation for taking + + align:start position:0% +take and the compensation for taking + + + align:start position:0% +take and the compensation for taking +extra risk is extra return and we + + align:start position:0% +extra risk is extra return and we + + + align:start position:0% +extra risk is extra return and we +achieve that by essentially investing in + + align:start position:0% +achieve that by essentially investing in + + + align:start position:0% +achieve that by essentially investing in +the same portfolio only we change the + + align:start position:0% +the same portfolio only we change the + + + align:start position:0% +the same portfolio only we change the +scale at which we're investing in that + + align:start position:0% +scale at which we're investing in that + + + align:start position:0% +scale at which we're investing in that +portfolio so + + align:start position:0% +portfolio so + + + align:start position:0% +portfolio so +uh now + + align:start position:0% +uh now + + + align:start position:0% +uh now +if right now so far we've been been + + align:start position:0% +if right now so far we've been been + + + align:start position:0% +if right now so far we've been been +considering sort of points so between uh + + align:start position:0% +considering sort of points so between uh + + + align:start position:0% +considering sort of points so between uh +being fully invested in the market or + + align:start position:0% +being fully invested in the market or + + + align:start position:0% +being fully invested in the market or +fully invested in cash if we are able to + + align:start position:0% +fully invested in cash if we are able to + + + align:start position:0% +fully invested in cash if we are able to +borrow + + align:start position:0% +borrow + + + align:start position:0% +borrow +money at the risk-free + + align:start position:0% +money at the risk-free + + + align:start position:0% +money at the risk-free +rate then we can basically allocate + + align:start position:0% +rate then we can basically allocate + + + align:start position:0% +rate then we can basically allocate +additional weights to the market + + align:start position:0% +additional weights to the market + + + align:start position:0% +additional weights to the market +portfolio and Achieve + + align:start position:0% +portfolio and Achieve + + + align:start position:0% +portfolio and Achieve +points that are + + align:start position:0% +points that are + + + align:start position:0% +points that are +Beyond you know have higher return + + align:start position:0% +Beyond you know have higher return + + + align:start position:0% +Beyond you know have higher return +higher volatility than the market + + align:start position:0% +higher volatility than the market + + + align:start position:0% +higher volatility than the market +portfolio we can basically lever the + + align:start position:0% +portfolio we can basically lever the + + + align:start position:0% +portfolio we can basically lever the +strategy by borrowing money and + + align:start position:0% +strategy by borrowing money and + + + align:start position:0% +strategy by borrowing money and +investing that in in in this market + + align:start position:0% +investing that in in in this market + + + align:start position:0% +investing that in in in this market +portfolio so so this + + align:start position:0% +portfolio so so this + + + align:start position:0% +portfolio so so this +uh efficient + + align:start position:0% +uh efficient + + + align:start position:0% +uh efficient +Frontier uh if we can borrow riskless + + align:start position:0% +Frontier uh if we can borrow riskless + + + align:start position:0% +Frontier uh if we can borrow riskless +you know would it just be the Capital + + align:start position:0% +you know would it just be the Capital + + + align:start position:0% +you know would it just be the Capital +Market line + + align:start position:0% + + + + align:start position:0% + +extended um here's a listing of of the + + align:start position:0% +extended um here's a listing of of the + + + align:start position:0% +extended um here's a listing of of the +papers that go through sort of the + + align:start position:0% +papers that go through sort of the + + + align:start position:0% +papers that go through sort of the +classical foundations for the and I + + align:start position:0% +classical foundations for the and I + + + align:start position:0% +classical foundations for the and I +these are all accessible on the web and + + align:start position:0% +these are all accessible on the web and + + + align:start position:0% +these are all accessible on the web and +I encourage you to actually look at + + align:start position:0% +I encourage you to actually look at + + + align:start position:0% +I encourage you to actually look at +these papers because uh the arguments + + align:start position:0% +these papers because uh the arguments + + + align:start position:0% +these papers because uh the arguments +are very straightforward the motivation + + align:start position:0% +are very straightforward the motivation + + + align:start position:0% +are very straightforward the motivation +and uh background is is is interesting + + align:start position:0% +and uh background is is is interesting + + + align:start position:0% +and uh background is is is interesting +to read um I virtually everyone on this + + align:start position:0% +to read um I virtually everyone on this + + + align:start position:0% +to read um I virtually everyone on this +page actually has a Nobel Prize except + + align:start position:0% +page actually has a Nobel Prize except + + + align:start position:0% +page actually has a Nobel Prize except +lintner I think he died before they gave + + align:start position:0% +lintner I think he died before they gave + + + align:start position:0% +lintner I think he died before they gave +the Nobel Prize to Mark witz and sharp + + align:start position:0% +the Nobel Prize to Mark witz and sharp + + + align:start position:0% +the Nobel Prize to Mark witz and sharp +uh but he would certainly would have + + align:start position:0% +uh but he would certainly would have + + + align:start position:0% +uh but he would certainly would have +been included in this case + + align:start position:0% + + + + align:start position:0% + +pardon me the latest and the latest one + + align:start position:0% +pardon me the latest and the latest one + + + align:start position:0% +pardon me the latest and the latest one +yes yes F was just awarded what two + + align:start position:0% +yes yes F was just awarded what two + + + align:start position:0% +yes yes F was just awarded what two +weeks + + align:start position:0% + + + + align:start position:0% + +ago all right + + align:start position:0% + + + + align:start position:0% + +let's okay let's move on to uh Von + + align:start position:0% +let's okay let's move on to uh Von + + + align:start position:0% +let's okay let's move on to uh Von +noyman Morganstern utility + + align:start position:0% + + + + align:start position:0% + +Theory now in in the markwitz mean + + align:start position:0% +Theory now in in the markwitz mean + + + align:start position:0% +Theory now in in the markwitz mean +variance analysis we sort of reduced all + + align:start position:0% +variance analysis we sort of reduced all + + + align:start position:0% +variance analysis we sort of reduced all +portfolios to the properties of what's + + align:start position:0% +portfolios to the properties of what's + + + align:start position:0% +portfolios to the properties of what's +their expected return and what's their + + align:start position:0% +their expected return and what's their + + + align:start position:0% +their expected return and what's their +the variance or volatility of the + + align:start position:0% +the variance or volatility of the + + + align:start position:0% +the variance or volatility of the +returns + + align:start position:0% +returns + + + align:start position:0% +returns +um why under what circumstances would + + align:start position:0% +um why under what circumstances would + + + align:start position:0% +um why under what circumstances would +that be a really good decision to be + + align:start position:0% +that be a really good decision to be + + + align:start position:0% +that be a really good decision to be +making for how to do + + align:start position:0% +making for how to do + + + align:start position:0% +making for how to do +portfolio uh optimization portfolio + + align:start position:0% +portfolio uh optimization portfolio + + + align:start position:0% +portfolio uh optimization portfolio +allocations well uh V noyman the V + + align:start position:0% +allocations well uh V noyman the V + + + align:start position:0% +allocations well uh V noyman the V +noyman Morganstern theory is a theory + + align:start position:0% +noyman Morganstern theory is a theory + + + align:start position:0% +noyman Morganstern theory is a theory +which + + align:start position:0% +which + + + align:start position:0% +which +motivates making decisions under + + align:start position:0% +motivates making decisions under + + + align:start position:0% +motivates making decisions under +uncertainty + + align:start position:0% +uncertainty + + + align:start position:0% +uncertainty +where you should specify a utility + + align:start position:0% +where you should specify a utility + + + align:start position:0% +where you should specify a utility +function for your + + align:start position:0% +function for your + + + align:start position:0% +function for your +wealth and you should engage in + + align:start position:0% +wealth and you should engage in + + + align:start position:0% +wealth and you should engage in +decisions that maximize the expected + + align:start position:0% +decisions that maximize the expected + + + align:start position:0% +decisions that maximize the expected +utility of your wealth and uh the theory + + align:start position:0% +utility of your wealth and uh the theory + + + align:start position:0% +utility of your wealth and uh the theory +is is really very uh powerful um in that + + align:start position:0% +is is really very uh powerful um in that + + + align:start position:0% +is is really very uh powerful um in that +uh the + + align:start position:0% +uh the + + + align:start position:0% +uh the +uh when you're making decisions under + + align:start position:0% +uh when you're making decisions under + + + align:start position:0% +uh when you're making decisions under +uncertainty that there are there's are + + align:start position:0% +uncertainty that there are there's are + + + align:start position:0% +uncertainty that there are there's are +rational things you should do um you + + align:start position:0% +rational things you should do um you + + + align:start position:0% +rational things you should do um you +know you basically um like you if you + + align:start position:0% +know you basically um like you if you + + + align:start position:0% +know you basically um like you if you +like higher return you know you the + + align:start position:0% +like higher return you know you the + + + align:start position:0% +like higher return you know you the +decision should be consistent with + + align:start position:0% +decision should be consistent with + + + align:start position:0% +decision should be consistent with +preferring uh outcomes with higher + + align:start position:0% +preferring uh outcomes with higher + + + align:start position:0% +preferring uh outcomes with higher +returns if you don't like variability + + align:start position:0% +returns if you don't like variability + + + align:start position:0% +returns if you don't like variability +then you should be preferring returns + + align:start position:0% +then you should be preferring returns + + + align:start position:0% +then you should be preferring returns +that have the same expected return that + + align:start position:0% +that have the same expected return that + + + align:start position:0% +that have the same expected return that +have lower volatility um but depending + + align:start position:0% +have lower volatility um but depending + + + align:start position:0% +have lower volatility um but depending +on how your utility function is defined + + align:start position:0% +on how your utility function is defined + + + align:start position:0% +on how your utility function is defined +you may get different different outcomes + + align:start position:0% +you may get different different outcomes + + + align:start position:0% +you may get different different outcomes +and uh the uh so so to set up this + + align:start position:0% +and uh the uh so so to set up this + + + align:start position:0% +and uh the uh so so to set up this +problem let's just consider you know the + + align:start position:0% +problem let's just consider you know the + + + align:start position:0% +problem let's just consider you know the +the problem that Mark was addressed you + + align:start position:0% +the problem that Mark was addressed you + + + align:start position:0% +the problem that Mark was addressed you +have a one period investment you start + + align:start position:0% +have a one period investment you start + + + align:start position:0% +have a one period investment you start +with initial wealth w0 you're going to + + align:start position:0% +with initial wealth w0 you're going to + + + align:start position:0% +with initial wealth w0 you're going to +choose a portfolio p and uh the wealth + + align:start position:0% +choose a portfolio p and uh the wealth + + + align:start position:0% +choose a portfolio p and uh the wealth +after one period is simply going to be + + align:start position:0% +after one period is simply going to be + + + align:start position:0% +after one period is simply going to be +one plus the return on that portfolio + + align:start position:0% +one plus the return on that portfolio + + + align:start position:0% +one plus the return on that portfolio +given uh terminal wealth W and our + + align:start position:0% +given uh terminal wealth W and our + + + align:start position:0% +given uh terminal wealth W and our +utility function is going to be some + + align:start position:0% +utility function is going to be some + + + align:start position:0% +utility function is going to be some +quantitative measure of the outcome + + align:start position:0% +quantitative measure of the outcome + + + align:start position:0% +quantitative measure of the outcome +what's the value to the investor and we + + align:start position:0% +what's the value to the investor and we + + + align:start position:0% +what's the value to the investor and we +simply want to uh compute the expected + + align:start position:0% +simply want to uh compute the expected + + + align:start position:0% +simply want to uh compute the expected +volatility of different strategies and + + align:start position:0% +volatility of different strategies and + + + align:start position:0% +volatility of different strategies and +find the strategy that maximizes the + + align:start position:0% +find the strategy that maximizes the + + + align:start position:0% +find the strategy that maximizes the +expected + + align:start position:0% + + + + align:start position:0% + +utility what kind what would or what are + + align:start position:0% +utility what kind what would or what are + + + align:start position:0% +utility what kind what would or what are +the basic properties of utility + + align:start position:0% +the basic properties of utility + + + align:start position:0% +the basic properties of utility +functions + + align:start position:0% +functions + + + align:start position:0% +functions +well you know if we + + align:start position:0% +well you know if we + + + align:start position:0% +well you know if we +graph over wealth + + align:start position:0% +graph over wealth + + + align:start position:0% +graph over wealth +our utility of + + align:start position:0% +our utility of + + + align:start position:0% +our utility of +wealth starting at w0 our initial + + align:start position:0% +wealth starting at w0 our initial + + + align:start position:0% +wealth starting at w0 our initial +wealth if + + align:start position:0% +wealth if + + + align:start position:0% +wealth if +we + + align:start position:0% +we + + + align:start position:0% +we +uh have greater wealth + + align:start position:0% +uh have greater wealth + + + align:start position:0% +uh have greater wealth +presumably uh will have greater utility + + align:start position:0% +presumably uh will have greater utility + + + align:start position:0% +presumably uh will have greater utility +so the slope of the utility function + + align:start position:0% +so the slope of the utility function + + + align:start position:0% +so the slope of the utility function +should be + + align:start position:0% +should be + + + align:start position:0% +should be +increasing perhaps as we get more and + + align:start position:0% +increasing perhaps as we get more and + + + align:start position:0% +increasing perhaps as we get more and +more wealthy the mark marginal benefit + + align:start position:0% +more wealthy the mark marginal benefit + + + align:start position:0% +more wealthy the mark marginal benefit +of additional wealth isn't quite as much + + align:start position:0% +of additional wealth isn't quite as much + + + align:start position:0% +of additional wealth isn't quite as much +as it was when we were poor and so + + align:start position:0% +as it was when we were poor and so + + + align:start position:0% +as it was when we were poor and so +perhaps the curve for the utility + + align:start position:0% +perhaps the curve for the utility + + + align:start position:0% +perhaps the curve for the utility +function should taper off a bit okay + + align:start position:0% +function should taper off a bit okay + + + align:start position:0% +function should taper off a bit okay +these conditions um would correspond to + + align:start position:0% +these conditions um would correspond to + + + align:start position:0% +these conditions um would correspond to +the first derivative being increasing + + align:start position:0% +the first derivative being increasing + + + align:start position:0% +the first derivative being increasing +always and the second derivative being + + align:start position:0% +always and the second derivative being + + + align:start position:0% +always and the second derivative being +less than zero + + align:start position:0% +less than zero + + + align:start position:0% +less than zero +perhaps + + align:start position:0% +perhaps + + + align:start position:0% +perhaps +um there are definitions in the + + align:start position:0% +um there are definitions in the + + + align:start position:0% +um there are definitions in the +literature of risk aversion absolute + + align:start position:0% +literature of risk aversion absolute + + + align:start position:0% +literature of risk aversion absolute +risk aversion and relative risk + + align:start position:0% +risk aversion and relative risk + + + align:start position:0% +risk aversion and relative risk +aversion um and these are simple + + align:start position:0% +aversion um and these are simple + + + align:start position:0% +aversion um and these are simple +functions of the first and second + + align:start position:0% +functions of the first and second + + + align:start position:0% +functions of the first and second +derivatives of the utility function to + + align:start position:0% +derivatives of the utility function to + + + align:start position:0% +derivatives of the utility function to +see where these come into play Let's + + align:start position:0% +see where these come into play Let's + + + align:start position:0% +see where these come into play Let's +just look at let's assume that the + + align:start position:0% +just look at let's assume that the + + + align:start position:0% +just look at let's assume that the +utility function is a smooth function + + align:start position:0% +utility function is a smooth function + + + align:start position:0% +utility function is a smooth function +and uh consider a tailor series + + align:start position:0% +and uh consider a tailor series + + + align:start position:0% +and uh consider a tailor series +approximation of that so if we consider + + align:start position:0% +approximation of that so if we consider + + + align:start position:0% +approximation of that so if we consider +expanding the utility function about + + align:start position:0% +expanding the utility function about + + + align:start position:0% +expanding the utility function about +some base wealth + + align:start position:0% +some base wealth + + + align:start position:0% +some base wealth +wstar then it's simply equal to to you + + align:start position:0% +wstar then it's simply equal to to you + + + align:start position:0% +wstar then it's simply equal to to you +know that value at w Star Plus the first + + align:start position:0% +know that value at w Star Plus the first + + + align:start position:0% +know that value at w Star Plus the first +derivative time wus W Star Plus uh 1 + + align:start position:0% +derivative time wus W Star Plus uh 1 + + + align:start position:0% +derivative time wus W Star Plus uh 1 +half the second derivative times the + + align:start position:0% +half the second derivative times the + + + align:start position:0% +half the second derivative times the +squar deviation of the wealth from W + + align:start position:0% +squar deviation of the wealth from W + + + align:start position:0% +squar deviation of the wealth from W +star and if we take expectations of + + align:start position:0% +star and if we take expectations of + + + align:start position:0% +star and if we take expectations of +this and if W star is the actual + + align:start position:0% +this and if W star is the actual + + + align:start position:0% +this and if W star is the actual +expected wealth of the random variable + + align:start position:0% +expected wealth of the random variable + + + align:start position:0% +expected wealth of the random variable +then the this expected utility is + + align:start position:0% +then the this expected utility is + + + align:start position:0% +then the this expected utility is +actually proportional to + + align:start position:0% +actually proportional to + + + align:start position:0% +actually proportional to +the expected wealth minus a half Lambda + + align:start position:0% +the expected wealth minus a half Lambda + + + align:start position:0% +the expected wealth minus a half Lambda +times the variance of the wealth so sort + + align:start position:0% +times the variance of the wealth so sort + + + align:start position:0% +times the variance of the wealth so sort +of to a whatever second order + + align:start position:0% +of to a whatever second order + + + align:start position:0% +of to a whatever second order +approximation this expected utility + + align:start position:0% +approximation this expected utility + + + align:start position:0% +approximation this expected utility +is a function which is looking at + + align:start position:0% +is a function which is looking at + + + align:start position:0% +is a function which is looking at +expected return minus a multiple of the + + align:start position:0% +expected return minus a multiple of the + + + align:start position:0% +expected return minus a multiple of the +volatility of that return or the wealth + + align:start position:0% +volatility of that return or the wealth + + + align:start position:0% +volatility of that return or the wealth +if we're considering it on that + + align:start position:0% +if we're considering it on that + + + align:start position:0% +if we're considering it on that +scale um so + + align:start position:0% +scale um so + + + align:start position:0% +scale um so +well there are various different utility + + align:start position:0% +well there are various different utility + + + align:start position:0% +well there are various different utility +functions that economists have uh worked + + align:start position:0% +functions that economists have uh worked + + + align:start position:0% +functions that economists have uh worked +with and you know + + align:start position:0% +with and you know + + + align:start position:0% +with and you know +basically the kinds of functions they + + align:start position:0% +basically the kinds of functions they + + + align:start position:0% +basically the kinds of functions they +work with are all the simple functions + + align:start position:0% +work with are all the simple functions + + + align:start position:0% +work with are all the simple functions +we as mathematicians know about linear + + align:start position:0% +we as mathematicians know about linear + + + align:start position:0% +we as mathematicians know about linear +functions quadratic functions + + align:start position:0% +functions quadratic functions + + + align:start position:0% +functions quadratic functions +exponential functions power functions + + align:start position:0% +exponential functions power functions + + + align:start position:0% +exponential functions power functions +right and log functions so you know + + align:start position:0% +right and log functions so you know + + + align:start position:0% +right and log functions so you know +these are just uh you know the first + + align:start position:0% +these are just uh you know the first + + + align:start position:0% +these are just uh you know the first +ones uh that come to mind perhaps to + + align:start position:0% +ones uh that come to mind perhaps to + + + align:start position:0% +ones uh that come to mind perhaps to +economists but um there's actually a a + + align:start position:0% +economists but um there's actually a a + + + align:start position:0% +economists but um there's actually a a +some rich theory in terms terms of uh + + align:start position:0% +some rich theory in terms terms of uh + + + align:start position:0% +some rich theory in terms terms of uh +sort of portfolio or investment Choice + + align:start position:0% +sort of portfolio or investment Choice + + + align:start position:0% +sort of portfolio or investment Choice +with different utility functions of of + + align:start position:0% +with different utility functions of of + + + align:start position:0% +with different utility functions of of +these types and uh uh you know there's + + align:start position:0% +these types and uh uh you know there's + + + align:start position:0% +these types and uh uh you know there's +there's there there is some interesting + + align:start position:0% +there's there there is some interesting + + + align:start position:0% +there's there there is some interesting +work work there in the economics + + align:start position:0% +work work there in the economics + + + align:start position:0% +work work there in the economics +literature um one thing that is + + align:start position:0% +literature um one thing that is + + + align:start position:0% +literature um one thing that is +uh uh to be pointed out is that with + + align:start position:0% +uh uh to be pointed out is that with + + + align:start position:0% +uh uh to be pointed out is that with +quadratic + + align:start position:0% +quadratic + + + align:start position:0% +quadratic +utility then if we consider the expected + + align:start position:0% +utility then if we consider the expected + + + align:start position:0% +utility then if we consider the expected +utility under quadratic utility that is + + align:start position:0% +utility under quadratic utility that is + + + align:start position:0% +utility under quadratic utility that is +a expected utility function that only + + align:start position:0% +a expected utility function that only + + + align:start position:0% +a expected utility function that only +only depends on the expected wealth and + + align:start position:0% +only depends on the expected wealth and + + + align:start position:0% +only depends on the expected wealth and +the variance of the wealth which depends + + align:start position:0% +the variance of the wealth which depends + + + align:start position:0% +the variance of the wealth which depends +only on the expected return and the + + align:start position:0% +only on the expected return and the + + + align:start position:0% +only on the expected return and the +variance of the return of the portfolio + + align:start position:0% +variance of the return of the portfolio + + + align:start position:0% +variance of the return of the portfolio +so if we are working with a quadratic + + align:start position:0% +so if we are working with a quadratic + + + align:start position:0% +so if we are working with a quadratic +utility + + align:start position:0% +utility + + + align:start position:0% +utility +function then this mean variance + + align:start position:0% +function then this mean variance + + + align:start position:0% +function then this mean variance +analysis is the right thing to be doing + + align:start position:0% +analysis is the right thing to be doing + + + align:start position:0% +analysis is the right thing to be doing +under the Von no and Morganstern + + align:start position:0% +under the Von no and Morganstern + + + align:start position:0% +under the Von no and Morganstern +expected utility + + align:start position:0% +expected utility + + + align:start position:0% +expected utility +Theory so uh so doing that is + + align:start position:0% +Theory so uh so doing that is + + + align:start position:0% +Theory so uh so doing that is +is a good a good decision under under + + align:start position:0% +is a good a good decision under under + + + align:start position:0% +is a good a good decision under under +that if that's the utility function now + + align:start position:0% +that if that's the utility function now + + + align:start position:0% +that if that's the utility function now +when is that solution not to be + + align:start position:0% +when is that solution not to be + + + align:start position:0% +when is that solution not to be +preferred well really it's not to be + + align:start position:0% +preferred well really it's not to be + + + align:start position:0% +preferred well really it's not to be +preferred if you have a different + + align:start position:0% +preferred if you have a different + + + align:start position:0% +preferred if you have a different +utility function possibly and maybe the + + align:start position:0% +utility function possibly and maybe the + + + align:start position:0% +utility function possibly and maybe the +uh utility function should be adding + + align:start position:0% +uh utility function should be adding + + + align:start position:0% +uh utility function should be adding +some penalties for skewness or + + align:start position:0% +some penalties for skewness or + + + align:start position:0% +some penalties for skewness or +curtosis and that's being ignored here + + align:start position:0% +curtosis and that's being ignored here + + + align:start position:0% +curtosis and that's being ignored here +so extensions can can can be uh looked + + align:start position:0% +so extensions can can can be uh looked + + + align:start position:0% +so extensions can can can be uh looked +at uh an interesting mathematical fact + + align:start position:0% +at uh an interesting mathematical fact + + + align:start position:0% +at uh an interesting mathematical fact +is that you know under the + + align:start position:0% +is that you know under the + + + align:start position:0% +is that you know under the +assumption or should I say the + + align:start position:0% +assumption or should I say the + + + align:start position:0% +assumption or should I say the +imagination that returns are gaussian + + align:start position:0% +imagination that returns are gaussian + + + align:start position:0% +imagination that returns are gaussian +distributed um then the sort of means + + align:start position:0% +distributed um then the sort of means + + + align:start position:0% +distributed um then the sort of means +and variances of portfolios completely + + align:start position:0% +and variances of portfolios completely + + + align:start position:0% +and variances of portfolios completely +characterize all the distributions of of + + align:start position:0% +characterize all the distributions of of + + + align:start position:0% +characterize all the distributions of of +portfolios of assets if the underlying + + align:start position:0% +portfolios of assets if the underlying + + + align:start position:0% +portfolios of assets if the underlying +assets are gaussing distributions so a + + align:start position:0% +assets are gaussing distributions so a + + + align:start position:0% +assets are gaussing distributions so a +mean variance analysis is actually + + align:start position:0% +mean variance analysis is actually + + + align:start position:0% +mean variance analysis is actually +optimal under non-quadratic + + align:start position:0% +optimal under non-quadratic + + + align:start position:0% +optimal under non-quadratic +uh utility + + align:start position:0% +uh utility + + + align:start position:0% +uh utility +functions if the underlying assets are + + align:start position:0% +functions if the underlying assets are + + + align:start position:0% +functions if the underlying assets are +have gaussin distributions because + + align:start position:0% +have gaussin distributions because + + + align:start position:0% +have gaussin distributions because +basically only the means and variances + + align:start position:0% +basically only the means and variances + + + align:start position:0% +basically only the means and variances +are going to characterize the optimal + + align:start position:0% +are going to characterize the optimal + + + align:start position:0% +are going to characterize the optimal +portfolios and properties of those and + + align:start position:0% +portfolios and properties of those and + + + align:start position:0% +portfolios and properties of those and +uh uh basally stochastic dominance of + + align:start position:0% +uh uh basally stochastic dominance of + + + align:start position:0% +uh uh basally stochastic dominance of +functions of these variables will + + align:start position:0% +functions of these variables will + + + align:start position:0% +functions of these variables will +generally apply when the uh there's that + + align:start position:0% +generally apply when the uh there's that + + + align:start position:0% +generally apply when the uh there's that +corresponding stochastic dominance in + + align:start position:0% +corresponding stochastic dominance in + + + align:start position:0% +corresponding stochastic dominance in +terms of their means and variances + + align:start position:0% +terms of their means and variances + + + align:start position:0% +terms of their means and variances +anyway that this kind of theory can can + + align:start position:0% +anyway that this kind of theory can can + + + align:start position:0% +anyway that this kind of theory can can +uh can get involved but allows us to + + align:start position:0% +uh can get involved but allows us to + + + align:start position:0% +uh can get involved but allows us to +extend the the basic model that we + + align:start position:0% +extend the the basic model that we + + + align:start position:0% +extend the the basic model that we +consider + + align:start position:0% +consider + + + align:start position:0% +consider +here let's turn to then to the topic of + + align:start position:0% +here let's turn to then to the topic of + + + align:start position:0% +here let's turn to then to the topic of +uh portfolio constraints so far in + + align:start position:0% +uh portfolio constraints so far in + + + align:start position:0% +uh portfolio constraints so far in +looking at this problem we haven't made + + align:start position:0% +looking at this problem we haven't made + + + align:start position:0% +looking at this problem we haven't made +any constraints on the problem we just + + align:start position:0% +any constraints on the problem we just + + + align:start position:0% +any constraints on the problem we just +want to maximize return minimize + + align:start position:0% +want to maximize return minimize + + + align:start position:0% +want to maximize return minimize +variance and uh consider trade-offs + + align:start position:0% +variance and uh consider trade-offs + + + align:start position:0% +variance and uh consider trade-offs +between those um with uh pract with + + align:start position:0% +between those um with uh pract with + + + align:start position:0% +between those um with uh pract with +practical uh portfolio optimization + + align:start position:0% +practical uh portfolio optimization + + + align:start position:0% +practical uh portfolio optimization +problems there there are different + + align:start position:0% +problems there there are different + + + align:start position:0% +problems there there are different +constraints that come into play + + align:start position:0% +constraints that come into play + + + align:start position:0% +constraints that come into play +um portfolios that are long only + + align:start position:0% +um portfolios that are long only + + + align:start position:0% +um portfolios that are long only +constrain the weights to only be + + align:start position:0% +constrain the weights to only be + + + align:start position:0% +constrain the weights to only be +positive there can be holding + + align:start position:0% +positive there can be holding + + + align:start position:0% +positive there can be holding +constraints which uh and it may be that + + align:start position:0% +constraints which uh and it may be that + + + align:start position:0% +constraints which uh and it may be that +we don't want the amount of a given + + align:start position:0% +we don't want the amount of a given + + + align:start position:0% +we don't want the amount of a given +asset to be too too big um in uh + + align:start position:0% +asset to be too too big um in uh + + + align:start position:0% +asset to be too too big um in uh +basically Equity strategies you you + + align:start position:0% +basically Equity strategies you you + + + align:start position:0% +basically Equity strategies you you +don't want to be holding uh if you have + + align:start position:0% +don't want to be holding uh if you have + + + align:start position:0% +don't want to be holding uh if you have +a sort of a medium frequency trading + + align:start position:0% +a sort of a medium frequency trading + + + align:start position:0% +a sort of a medium frequency trading +strategy and equities you don't want to + + align:start position:0% +strategy and equities you don't want to + + + align:start position:0% +strategy and equities you don't want to +be holding uh much more than the trading + + align:start position:0% +be holding uh much more than the trading + + + align:start position:0% +be holding uh much more than the trading +volume of a few hours or maybe a day in + + align:start position:0% +volume of a few hours or maybe a day in + + + align:start position:0% +volume of a few hours or maybe a day in +in the asset because if you're have + + align:start position:0% +in the asset because if you're have + + + align:start position:0% +in the asset because if you're have +having to sell it uh you know there + + align:start position:0% +having to sell it uh you know there + + + align:start position:0% +having to sell it uh you know there +really won't be the liquidity to trade + + align:start position:0% +really won't be the liquidity to trade + + + align:start position:0% +really won't be the liquidity to trade +that um but uh we can + + align:start position:0% +that um but uh we can + + + align:start position:0% +that um but uh we can +add basically simple linear constraints + + align:start position:0% +add basically simple linear constraints + + + align:start position:0% +add basically simple linear constraints +on the Holdings there can be turnover + + align:start position:0% +on the Holdings there can be turnover + + + align:start position:0% +on the Holdings there can be turnover +constraints + + align:start position:0% + + + + align:start position:0% + +if we're + + align:start position:0% +if we're + + + align:start position:0% +if we're +considering um changing our or basically + + align:start position:0% +considering um changing our or basically + + + align:start position:0% +considering um changing our or basically +adjusting our portfolio uh from one + + align:start position:0% +adjusting our portfolio uh from one + + + align:start position:0% +adjusting our portfolio uh from one +period to the next uh we may not or + + align:start position:0% +period to the next uh we may not or + + + align:start position:0% +period to the next uh we may not or +there are limits in terms of how much we + + align:start position:0% +there are limits in terms of how much we + + + align:start position:0% +there are limits in terms of how much we +can actually trade of the different + + align:start position:0% +can actually trade of the different + + + align:start position:0% +can actually trade of the different +assets um there can be a benchmark + + align:start position:0% +assets um there can be a benchmark + + + align:start position:0% +assets um there can be a benchmark +exposure constraints um suppose we want + + align:start position:0% +exposure constraints um suppose we want + + + align:start position:0% +exposure constraints um suppose we want +to invest in a portfolio that's very + + align:start position:0% +to invest in a portfolio that's very + + + align:start position:0% +to invest in a portfolio that's very +much + + align:start position:0% +much + + + align:start position:0% +much +like um but basically a market index say + + align:start position:0% +like um but basically a market index say + + + align:start position:0% +like um but basically a market index say +the S&P + + align:start position:0% +the S&P + + + align:start position:0% +the S&P +500 um but we want to try and do better + + align:start position:0% +500 um but we want to try and do better + + + align:start position:0% +500 um but we want to try and do better +than the S&P 500 but um but at the but + + align:start position:0% +than the S&P 500 but um but at the but + + + align:start position:0% +than the S&P 500 but um but at the but +we don't but we want to protect + + align:start position:0% +we don't but we want to protect + + + align:start position:0% +we don't but we want to protect +ourselves from uh basically not being + + align:start position:0% +ourselves from uh basically not being + + + align:start position:0% +ourselves from uh basically not being +very close to the Benchmark if our bets + + align:start position:0% +very close to the Benchmark if our bets + + + align:start position:0% +very close to the Benchmark if our bets +basically on allocation are wrong then + + align:start position:0% +basically on allocation are wrong then + + + align:start position:0% +basically on allocation are wrong then +uh one can basically attempt one can + + align:start position:0% +uh one can basically attempt one can + + + align:start position:0% +uh one can basically attempt one can +control how different from the Benchmark + + align:start position:0% +control how different from the Benchmark + + + align:start position:0% +control how different from the Benchmark +allocation we are and and limit that uh + + align:start position:0% +allocation we are and and limit that uh + + + align:start position:0% +allocation we are and and limit that uh +that departure so we can uh basically + + align:start position:0% +that departure so we can uh basically + + + align:start position:0% +that departure so we can uh basically +limit how far from The Benchmark weights + + align:start position:0% +limit how far from The Benchmark weights + + + align:start position:0% +limit how far from The Benchmark weights +we want our portfolio to be and and and + + align:start position:0% +we want our portfolio to be and and and + + + align:start position:0% +we want our portfolio to be and and and +this is useful basically for considering + + align:start position:0% +this is useful basically for considering + + + align:start position:0% +this is useful basically for considering +strategies that uh do as well or better + + align:start position:0% +strategies that uh do as well or better + + + align:start position:0% +strategies that uh do as well or better +than particular Benchmark + + align:start position:0% +than particular Benchmark + + + align:start position:0% +than particular Benchmark +indices um related to this our tracking + + align:start position:0% +indices um related to this our tracking + + + align:start position:0% +indices um related to this our tracking +error + + align:start position:0% +error + + + align:start position:0% +error +constraints + + align:start position:0% +constraints + + + align:start position:0% +constraints +um you know in addition to to um + + align:start position:0% +um you know in addition to to um + + + align:start position:0% +um you know in addition to to um +basically not + + align:start position:0% +basically not + + + align:start position:0% +basically not +having allocation weights that depart + + align:start position:0% +having allocation weights that depart + + + align:start position:0% +having allocation weights that depart +much from The Benchmark weights uh we + + align:start position:0% +much from The Benchmark weights uh we + + + align:start position:0% +much from The Benchmark weights uh we +can consider how much variation is there + + align:start position:0% +can consider how much variation is there + + + align:start position:0% +can consider how much variation is there +in our + + align:start position:0% +in our + + + align:start position:0% +in our +portfolio uh compared with an underlying + + align:start position:0% +portfolio uh compared with an underlying + + + align:start position:0% +portfolio uh compared with an underlying +uh Benchmark and we can consider the + + align:start position:0% +uh Benchmark and we can consider the + + + align:start position:0% +uh Benchmark and we can consider the +tracking error between our portfolio p + + align:start position:0% +tracking error between our portfolio p + + + align:start position:0% +tracking error between our portfolio p +and the underlying Benchmark and measure + + align:start position:0% +and the underlying Benchmark and measure + + + align:start position:0% +and the underlying Benchmark and measure +that tracking error in terms of the + + align:start position:0% +that tracking error in terms of the + + + align:start position:0% +that tracking error in terms of the +variability of that difference and want + + align:start position:0% +variability of that difference and want + + + align:start position:0% +variability of that difference and want +to control that + + align:start position:0% + + + + align:start position:0% + +there are also risk factor constraints + + align:start position:0% +there are also risk factor constraints + + + align:start position:0% +there are also risk factor constraints +and in and in equity markets there are + + align:start position:0% +and in and in equity markets there are + + + align:start position:0% +and in and in equity markets there are +many different factors that uh affect uh + + align:start position:0% +many different factors that uh affect uh + + + align:start position:0% +many different factors that uh affect uh +returns um and uh these factors can be + + align:start position:0% +returns um and uh these factors can be + + + align:start position:0% +returns um and uh these factors can be +identified + + align:start position:0% +identified + + + align:start position:0% +identified +empirically uh and controlled for by + + align:start position:0% +empirically uh and controlled for by + + + align:start position:0% +empirically uh and controlled for by +basically limiting the exposure to + + align:start position:0% +basically limiting the exposure to + + + align:start position:0% +basically limiting the exposure to +different factors in in the portfolio I + + align:start position:0% +different factors in in the portfolio I + + + align:start position:0% +different factors in in the portfolio I +we'll see this in our uh uh next lecture + + align:start position:0% +we'll see this in our uh uh next lecture + + + align:start position:0% +we'll see this in our uh uh next lecture +some but uh basically if they're + + align:start position:0% +some but uh basically if they're + + + align:start position:0% +some but uh basically if they're +underlying factors F which + + align:start position:0% +underlying factors F which + + + align:start position:0% +underlying factors F which +uh basically a return on asset I can be + + align:start position:0% +uh basically a return on asset I can be + + + align:start position:0% +uh basically a return on asset I can be +explained by sort of an idios + + align:start position:0% +explained by sort of an idios + + + align:start position:0% +explained by sort of an idios +idiosyncratic Alpha for that asset + + align:start position:0% +idiosyncratic Alpha for that asset + + + align:start position:0% +idiosyncratic Alpha for that asset +plus certain correlations with Market + + align:start position:0% +plus certain correlations with Market + + + align:start position:0% +plus certain correlations with Market +factors F and and then a residual uh + + align:start position:0% +factors F and and then a residual uh + + + align:start position:0% +factors F and and then a residual uh +Innovation Epsilon um and + + align:start position:0% +Innovation Epsilon um and + + + align:start position:0% +Innovation Epsilon um and +so the Returns on these assets can uh be + + align:start position:0% +so the Returns on these assets can uh be + + + align:start position:0% +so the Returns on these assets can uh be +explained perhaps 50% by underlying + + align:start position:0% +explained perhaps 50% by underlying + + + align:start position:0% +explained perhaps 50% by underlying +Market + + align:start position:0% +Market + + + align:start position:0% +Market +forces and um given by the underlying + + align:start position:0% +forces and um given by the underlying + + + align:start position:0% +forces and um given by the underlying +factors fjt which are uh constant across + + align:start position:0% +factors fjt which are uh constant across + + + align:start position:0% +factors fjt which are uh constant across +ey so these are affecting all the stocks + + align:start position:0% +ey so these are affecting all the stocks + + + align:start position:0% +ey so these are affecting all the stocks +with different coefficients beta + + align:start position:0% +with different coefficients beta + + + align:start position:0% +with different coefficients beta +ik and uh in a portfolio + + align:start position:0% +ik and uh in a portfolio + + + align:start position:0% +ik and uh in a portfolio +we may want to limit the exposure to a + + align:start position:0% +we may want to limit the exposure to a + + + align:start position:0% +we may want to limit the exposure to a +given factor and with many strategies + + align:start position:0% +given factor and with many strategies + + + align:start position:0% +given factor and with many strategies +you actually want to neutralize the + + align:start position:0% +you actually want to neutralize the + + + align:start position:0% +you actually want to neutralize the +portfolio to those Market risk factors + + align:start position:0% +portfolio to those Market risk factors + + + align:start position:0% +portfolio to those Market risk factors +so we can actually constrain our weights + + align:start position:0% +so we can actually constrain our weights + + + align:start position:0% +so we can actually constrain our weights +to have zero exposure across these + + align:start position:0% +to have zero exposure across these + + + align:start position:0% +to have zero exposure across these +different uh Market + + align:start position:0% + + + + align:start position:0% + +factors U there are other other + + align:start position:0% +factors U there are other other + + + align:start position:0% +factors U there are other other +constraints minimum transaction size + + align:start position:0% +constraints minimum transaction size + + + align:start position:0% +constraints minimum transaction size +um you know It generally is the case + + align:start position:0% +um you know It generally is the case + + + align:start position:0% +um you know It generally is the case +that uh know trades and equities are in + + align:start position:0% +that uh know trades and equities are in + + + align:start position:0% +that uh know trades and equities are in +in a 100 share units although that's + + align:start position:0% +in a 100 share units although that's + + + align:start position:0% +in a 100 share units although that's +changing um there can be minimum uh + + align:start position:0% +changing um there can be minimum uh + + + align:start position:0% +changing um there can be minimum uh +holding sizes and uh there's also + + align:start position:0% +holding sizes and uh there's also + + + align:start position:0% +holding sizes and uh there's also +integer constraints that that can be + + align:start position:0% +integer constraints that that can be + + + align:start position:0% +integer constraints that that can be +applied + + align:start position:0% +applied + + + align:start position:0% +applied +um if you're trading + + align:start position:0% +um if you're trading + + + align:start position:0% +um if you're trading +uh assets that have sort of large values + + align:start position:0% +uh assets that have sort of large values + + + align:start position:0% +uh assets that have sort of large values +then uh these integer constraints + + align:start position:0% +then uh these integer constraints + + + align:start position:0% +then uh these integer constraints +actually come into play I if you're + + align:start position:0% +actually come into play I if you're + + + align:start position:0% +actually come into play I if you're +trading Google stock and how much is + + align:start position:0% +trading Google stock and how much is + + + align:start position:0% +trading Google stock and how much is +Google stock worth now + + align:start position:0% +Google stock worth now + + + align:start position:0% +Google stock worth now +800 something like that so you know + + align:start position:0% +800 something like that so you know + + + align:start position:0% +800 something like that so you know +compare that with h Ford you know which + + align:start position:0% +compare that with h Ford you know which + + + align:start position:0% +compare that with h Ford you know which +is like $50 or I don't know but you know + + align:start position:0% +is like $50 or I don't know but you know + + + align:start position:0% +is like $50 or I don't know but you know +the orders of magnitude different so so + + align:start position:0% +the orders of magnitude different so so + + + align:start position:0% +the orders of magnitude different so so +integer constraints can come into play + + align:start position:0% +integer constraints can come into play + + + align:start position:0% +integer constraints can come into play +um if you're dealing in very large size + + align:start position:0% +um if you're dealing in very large size + + + align:start position:0% +um if you're dealing in very large size +then these things don't really have much + + align:start position:0% +then these things don't really have much + + + align:start position:0% +then these things don't really have much +of an impact but uh uh they can uh with + + align:start position:0% +of an impact but uh uh they can uh with + + + align:start position:0% +of an impact but uh uh they can uh with +smaller + + align:start position:0% +smaller + + + align:start position:0% +smaller +portfolios now all of these different + + align:start position:0% +portfolios now all of these different + + + align:start position:0% +portfolios now all of these different +constraints can be expressed as linear + + align:start position:0% +constraints can be expressed as linear + + + align:start position:0% +constraints can be expressed as linear +and quadratic constraints on the weights + + align:start position:0% +and quadratic constraints on the weights + + + align:start position:0% +and quadratic constraints on the weights +and uh so so the setup for uh the + + align:start position:0% +and uh so so the setup for uh the + + + align:start position:0% +and uh so so the setup for uh the +portfolio optimization problem can be + + align:start position:0% +portfolio optimization problem can be + + + align:start position:0% +portfolio optimization problem can be +the same as before except we add in + + align:start position:0% +the same as before except we add in + + + align:start position:0% +the same as before except we add in +these additional constraints so we add + + align:start position:0% +these additional constraints so we add + + + align:start position:0% +these additional constraints so we add +basically add in additional lrange + + align:start position:0% +basically add in additional lrange + + + align:start position:0% +basically add in additional lrange +multipliers times these particular + + align:start position:0% +multipliers times these particular + + + align:start position:0% +multipliers times these particular +constraints with their linear quadratic + + align:start position:0% +constraints with their linear quadratic + + + align:start position:0% +constraints with their linear quadratic +and we can implement the portfolio + + align:start position:0% +and we can implement the portfolio + + + align:start position:0% +and we can implement the portfolio +optimization problem that + + align:start position:0% +optimization problem that + + + align:start position:0% +optimization problem that +way let me uh turn to an + + align:start position:0% +way let me uh turn to an + + + align:start position:0% +way let me uh turn to an +example let's go + + align:start position:0% + + + + align:start position:0% + +let's + + align:start position:0% + + + + align:start position:0% + +see is + + align:start position:0% +see is + + + align:start position:0% +see is +that + + align:start position:0% +that + + + align:start position:0% +that +okay let me magnify this + + align:start position:0% +okay let me magnify this + + + align:start position:0% +okay let me magnify this +here okay I want + + align:start position:0% +here okay I want + + + align:start position:0% +here okay I want +to go through an + + align:start position:0% +to go through an + + + align:start position:0% +to go through an +example of uh + + align:start position:0% +example of uh + + + align:start position:0% +example of uh +uh I'll use the + + align:start position:0% + + + + align:start position:0% + +mouse okay I want to + + align:start position:0% +mouse okay I want to + + + align:start position:0% +mouse okay I want to +consider um us sector exchange traded + + align:start position:0% +consider um us sector exchange traded + + + align:start position:0% +consider um us sector exchange traded +funds between 2009 and last week um the + + align:start position:0% +funds between 2009 and last week um the + + + align:start position:0% +funds between 2009 and last week um the +uh basically there are uh you exchange + + align:start position:0% +uh basically there are uh you exchange + + + align:start position:0% +uh basically there are uh you exchange +trade FS allow you to + + align:start position:0% +trade FS allow you to + + + align:start position:0% +trade FS allow you to +invest in equity markets with sort of + + align:start position:0% +invest in equity markets with sort of + + + align:start position:0% +invest in equity markets with sort of +single assets that represent different + + align:start position:0% +single assets that represent different + + + align:start position:0% +single assets that represent different +sectors um the ones that are considered + + align:start position:0% +sectors um the ones that are considered + + + align:start position:0% +sectors um the ones that are considered +here are basically spider traded funds + + align:start position:0% +here are basically spider traded funds + + + align:start position:0% +here are basically spider traded funds +uh which invest in the different major + + align:start position:0% +uh which invest in the different major + + + align:start position:0% +uh which invest in the different major +industrial sectors of the US market uh + + align:start position:0% +industrial sectors of the US market uh + + + align:start position:0% +industrial sectors of the US market uh +ranging from materials Health Care + + align:start position:0% +ranging from materials Health Care + + + align:start position:0% +ranging from materials Health Care +Consumer Staples down to technology and + + align:start position:0% + + + + align:start position:0% + +utilities here + + align:start position:0% + + + + align:start position:0% + +is a graph of the cumulative returns of + + align:start position:0% +is a graph of the cumulative returns of + + + align:start position:0% +is a graph of the cumulative returns of +these nine different exchange traded + + align:start position:0% +these nine different exchange traded + + + align:start position:0% +these nine different exchange traded +funds and uh over the period uh from + + align:start position:0% +funds and uh over the period uh from + + + align:start position:0% +funds and uh over the period uh from +2009 up through uh last week and what + + align:start position:0% +2009 up through uh last week and what + + + align:start position:0% +2009 up through uh last week and what +one can see is uh basically they perform + + align:start position:0% +one can see is uh basically they perform + + + align:start position:0% +one can see is uh basically they perform +differently um and what I'd like to do + + align:start position:0% +differently um and what I'd like to do + + + align:start position:0% +differently um and what I'd like to do +is just examine of what would have + + align:start position:0% +is just examine of what would have + + + align:start position:0% +is just examine of what would have +been an optimal allocation across these + + align:start position:0% +been an optimal allocation across these + + + align:start position:0% +been an optimal allocation across these +exchange traded funds over this period + + align:start position:0% +exchange traded funds over this period + + + align:start position:0% +exchange traded funds over this period +so basically looking back at the data + + align:start position:0% +so basically looking back at the data + + + align:start position:0% +so basically looking back at the data +and seeing how our + + align:start position:0% +and seeing how our + + + align:start position:0% +and seeing how our +portfolio + + align:start position:0% +portfolio + + + align:start position:0% +portfolio +uh analysis uh tools um would would + + align:start position:0% +uh analysis uh tools um would would + + + align:start position:0% +uh analysis uh tools um would would +result in particular application + + align:start position:0% +result in particular application + + + align:start position:0% +result in particular application +allocations so um so we can look at the + + align:start position:0% +allocations so um so we can look at the + + + align:start position:0% +allocations so um so we can look at the +risk versus return annualized of these + + align:start position:0% +risk versus return annualized of these + + + align:start position:0% +risk versus return annualized of these +let's see + + align:start position:0% +let's see + + + align:start position:0% +let's see +this + + align:start position:0% +this + + + align:start position:0% +this +is I don't know if + + align:start position:0% + + + + align:start position:0% + +that's I guess that's good enough anyway + + align:start position:0% +that's I guess that's good enough anyway + + + align:start position:0% +that's I guess that's good enough anyway +what you can see is you know basically + + align:start position:0% +what you can see is you know basically + + + align:start position:0% +what you can see is you know basically +with volatility range between 0 and 30 + + align:start position:0% +with volatility range between 0 and 30 + + + align:start position:0% +with volatility range between 0 and 30 +OD annual ex return between 0 and + + align:start position:0% +OD annual ex return between 0 and + + + align:start position:0% +OD annual ex return between 0 and +25 um we have the different sectors in + + align:start position:0% +25 um we have the different sectors in + + + align:start position:0% +25 um we have the different sectors in +this uh in this plot so this is our + + align:start position:0% +this uh in this plot so this is our + + + align:start position:0% +this uh in this plot so this is our +feasible set + + align:start position:0% +feasible set + + + align:start position:0% +feasible set +of uh or this is the plot of return + + align:start position:0% +of uh or this is the plot of return + + + align:start position:0% +of uh or this is the plot of return +versus volatility for these nine + + align:start position:0% +versus volatility for these nine + + + align:start position:0% +versus volatility for these nine +exchange traded funds um this happens to + + align:start position:0% +exchange traded funds um this happens to + + + align:start position:0% +exchange traded funds um this happens to +be utilities there's financials over + + align:start position:0% +be utilities there's financials over + + + align:start position:0% +be utilities there's financials over +there here's Consumer Staples the very + + align:start position:0% +there here's Consumer Staples the very + + + align:start position:0% +there here's Consumer Staples the very +top is consumer uh + + align:start position:0% + + + + align:start position:0% + +discretionary let's see I applied a uh + + align:start position:0% +discretionary let's see I applied a uh + + + align:start position:0% +discretionary let's see I applied a uh +mean variance optimization to this + + align:start position:0% +mean variance optimization to this + + + align:start position:0% +mean variance optimization to this +problem + + align:start position:0% + + + + align:start position:0% + +uh assuming that There's a + + align:start position:0% +uh assuming that There's a + + + align:start position:0% +uh assuming that There's a +constraint of + + align:start position:0% +constraint of + + + align:start position:0% +constraint of +30% of the capital per asset so we don't + + align:start position:0% +30% of the capital per asset so we don't + + + align:start position:0% +30% of the capital per asset so we don't +want to invest more than 30% of the + + align:start position:0% +want to invest more than 30% of the + + + align:start position:0% +want to invest more than 30% of the +capital in any single exchange traded + + align:start position:0% +capital in any single exchange traded + + + align:start position:0% +capital in any single exchange traded +fund and this + + align:start position:0% + + + + align:start position:0% + +uh graph here shows how as we vary our + + align:start position:0% +uh graph here shows how as we vary our + + + align:start position:0% +uh graph here shows how as we vary our +Target return from sort of the minimum + + align:start position:0% +Target return from sort of the minimum + + + align:start position:0% +Target return from sort of the minimum +value up to the maximum value for being + + align:start position:0% +value up to the maximum value for being + + + align:start position:0% +value up to the maximum value for being +fully + + align:start position:0% +fully + + + align:start position:0% +fully +invested how much of the capital we're + + align:start position:0% +invested how much of the capital we're + + + align:start position:0% +invested how much of the capital we're +going to invest in the different sector + + align:start position:0% +going to invest in the different sector + + + align:start position:0% +going to invest in the different sector +funds so what you can see is this yellow + + align:start position:0% +funds so what you can see is this yellow + + + align:start position:0% +funds so what you can see is this yellow +one which is consumer staples is coming + + align:start position:0% +one which is consumer staples is coming + + + align:start position:0% +one which is consumer staples is coming +in with a really high weight and the + + align:start position:0% +in with a really high weight and the + + + align:start position:0% +in with a really high weight and the +green is + + align:start position:0% +green is + + + align:start position:0% +green is +energy um let's see I think it's energy + + align:start position:0% +energy um let's see I think it's energy + + + align:start position:0% +energy um let's see I think it's energy +that is is the next one then in Orange + + align:start position:0% +that is is the next one then in Orange + + + align:start position:0% +that is is the next one then in Orange +is is + + align:start position:0% +is is + + + align:start position:0% +is is +health and uh + + align:start position:0% + + + + align:start position:0% + +what's what's important to see is that + + align:start position:0% +what's what's important to see is that + + + align:start position:0% +what's what's important to see is that +when when we're looking sort of at the + + align:start position:0% +when when we're looking sort of at the + + + align:start position:0% +when when we're looking sort of at the +lower range of the returns basically + + align:start position:0% +lower range of the returns basically + + + align:start position:0% +lower range of the returns basically +expecting returns above the risk-free + + align:start position:0% +expecting returns above the risk-free + + + align:start position:0% +expecting returns above the risk-free +rate that's very low + + align:start position:0% +rate that's very low + + + align:start position:0% +rate that's very low +then the relative proportion invested in + + align:start position:0% +then the relative proportion invested in + + + align:start position:0% +then the relative proportion invested in +the different assets is the same + + align:start position:0% +the different assets is the same + + + align:start position:0% +the different assets is the same +basically these allocations are slowly + + align:start position:0% +basically these allocations are slowly + + + align:start position:0% +basically these allocations are slowly +scaling up just linearly and that + + align:start position:0% +scaling up just linearly and that + + + align:start position:0% +scaling up just linearly and that +corresponds to basically investing in + + align:start position:0% +corresponds to basically investing in + + + align:start position:0% +corresponds to basically investing in +the optimal port folio without + + align:start position:0% +the optimal port folio without + + + align:start position:0% +the optimal port folio without +constraints with a fixed + + align:start position:0% +constraints with a fixed + + + align:start position:0% +constraints with a fixed +value but once we hit the 30% level then + + align:start position:0% +value but once we hit the 30% level then + + + align:start position:0% +value but once we hit the 30% level then +that constraint starts to be active and + + align:start position:0% +that constraint starts to be active and + + + align:start position:0% +that constraint starts to be active and +we can't invest any more in that so we + + align:start position:0% +we can't invest any more in that so we + + + align:start position:0% +we can't invest any more in that so we +have to add more to other Securities and + + align:start position:0% +have to add more to other Securities and + + + align:start position:0% +have to add more to other Securities and +so basically more is given to uh the uh + + align:start position:0% +so basically more is given to uh the uh + + + align:start position:0% +so basically more is given to uh the uh +I think it's consumer + + align:start position:0% +I think it's consumer + + + align:start position:0% +I think it's consumer +discretionary and and the other now this + + align:start position:0% +discretionary and and the other now this + + + align:start position:0% +discretionary and and the other now this +graph actually here's another graph of + + align:start position:0% +graph actually here's another graph of + + + align:start position:0% +graph actually here's another graph of +the same data just stacking the + + align:start position:0% +the same data just stacking the + + + align:start position:0% +the same data just stacking the +allocation + + align:start position:0% +allocation + + + align:start position:0% +allocation +the allocation so we consider ranging + + align:start position:0% +the allocation so we consider ranging + + + align:start position:0% +the allocation so we consider ranging +from basically how are we investing all + + align:start position:0% +from basically how are we investing all + + + align:start position:0% +from basically how are we investing all +of our Capital the this dark red is how + + align:start position:0% +of our Capital the this dark red is how + + + align:start position:0% +of our Capital the this dark red is how +much money we invest in + + align:start position:0% +much money we invest in + + + align:start position:0% +much money we invest in +cash and then these colored lines + + align:start position:0% +cash and then these colored lines + + + align:start position:0% +cash and then these colored lines +indicate by their vertical length how + + align:start position:0% +indicate by their vertical length how + + + align:start position:0% +indicate by their vertical length how +much we're investing in the different + + align:start position:0% +much we're investing in the different + + + align:start position:0% +much we're investing in the different +exchange traded + + align:start position:0% +exchange traded + + + align:start position:0% +exchange traded +funds so so basically + + align:start position:0% +funds so so basically + + + align:start position:0% +funds so so basically +as the constraints get hit we basically + + align:start position:0% +as the constraints get hit we basically + + + align:start position:0% +as the constraints get hit we basically +the portfolio sort of change in terms of + + align:start position:0% +the portfolio sort of change in terms of + + + align:start position:0% +the portfolio sort of change in terms of +their overall structure + + align:start position:0% +their overall structure + + + align:start position:0% +their overall structure +and what can + + align:start position:0% +and what can + + + align:start position:0% +and what can +happen + + align:start position:0% +happen + + + align:start position:0% +happen +is um actually as we're trying to + + align:start position:0% +is um actually as we're trying to + + + align:start position:0% +is um actually as we're trying to +achieve more and more + + align:start position:0% +achieve more and more + + + align:start position:0% +achieve more and more +return well there may not be assets that + + align:start position:0% +return well there may not be assets that + + + align:start position:0% +return well there may not be assets that +provide that additional return or there + + align:start position:0% +provide that additional return or there + + + align:start position:0% +provide that additional return or there +may be a very few assets that provide + + align:start position:0% +may be a very few assets that provide + + + align:start position:0% +may be a very few assets that provide +that return and so that um in this case + + align:start position:0% +that return and so that um in this case + + + align:start position:0% +that return and so that um in this case +uh technology stocks are coming in as + + align:start position:0% +uh technology stocks are coming in as + + + align:start position:0% +uh technology stocks are coming in as +we're trying to get really high levels + + align:start position:0% +we're trying to get really high levels + + + align:start position:0% +we're trying to get really high levels +of return in our optimal + + align:start position:0% +of return in our optimal + + + align:start position:0% +of return in our optimal +portfolios and um so if we really want + + align:start position:0% +portfolios and um so if we really want + + + align:start position:0% +portfolios and um so if we really want +that higher return that's going to come + + align:start position:0% +that higher return that's going to come + + + align:start position:0% +that higher return that's going to come +at higher + + align:start position:0% +at higher + + + align:start position:0% +at higher +risk uh and we actually are deallocating + + align:start position:0% +risk uh and we actually are deallocating + + + align:start position:0% +risk uh and we actually are deallocating +some from uh the consumer staples and uh + + align:start position:0% +some from uh the consumer staples and uh + + + align:start position:0% +some from uh the consumer staples and uh +the consumer discretionary at that + + align:start position:0% + + + + align:start position:0% + +point okay this um okay here's a graph + + align:start position:0% +point okay this um okay here's a graph + + + align:start position:0% +point okay this um okay here's a graph +of the + + align:start position:0% +of the + + + align:start position:0% +of the +uh efficient Frontier + + align:start position:0% +uh efficient Frontier + + + align:start position:0% +uh efficient Frontier +as estimated with the with the data um + + align:start position:0% +as estimated with the with the data um + + + align:start position:0% +as estimated with the with the data um +and what you can see is that uh + + align:start position:0% +and what you can see is that uh + + + align:start position:0% +and what you can see is that uh +basically these portfolios optimal + + align:start position:0% +basically these portfolios optimal + + + align:start position:0% +basically these portfolios optimal +portfolios yield improvements over each + + align:start position:0% +portfolios yield improvements over each + + + align:start position:0% +portfolios yield improvements over each +of the individual exchange traded funds + + align:start position:0% +of the individual exchange traded funds + + + align:start position:0% +of the individual exchange traded funds +in terms of having higher return with + + align:start position:0% +in terms of having higher return with + + + align:start position:0% +in terms of having higher return with +lower + + align:start position:0% +lower + + + align:start position:0% +lower +risk + + align:start position:0% + + + + align:start position:0% + +um and as see if we consider just a + + align:start position:0% +um and as see if we consider just a + + + align:start position:0% +um and as see if we consider just a +Target return of 10% okay there's the + + align:start position:0% +Target return of 10% okay there's the + + + align:start position:0% +Target return of 10% okay there's the +optimal portfolio I've graft here sort + + align:start position:0% +optimal portfolio I've graft here sort + + + align:start position:0% +optimal portfolio I've graft here sort +of in solid blue what the uh optimal + + align:start position:0% +of in solid blue what the uh optimal + + + align:start position:0% +of in solid blue what the uh optimal +portfolio with a 10% uh volatility is + + align:start position:0% +portfolio with a 10% uh volatility is + + + align:start position:0% +portfolio with a 10% uh volatility is +that's the solid Blue Line there so this + + align:start position:0% +that's the solid Blue Line there so this + + + align:start position:0% +that's the solid Blue Line there so this +is the these are the results + + align:start position:0% +is the these are the results + + + align:start position:0% +is the these are the results +with + + align:start position:0% +with + + + align:start position:0% +with +uh this 30% Capital constraint now how + + align:start position:0% +uh this 30% Capital constraint now how + + + align:start position:0% +uh this 30% Capital constraint now how +is this problem going to change if we uh + + align:start position:0% +is this problem going to change if we uh + + + align:start position:0% +is this problem going to change if we uh +reduce the capital constraint from 30% + + align:start position:0% +reduce the capital constraint from 30% + + + align:start position:0% +reduce the capital constraint from 30% +per asset to 15% + + align:start position:0% + + + + align:start position:0% + +who can comment on what what will + + align:start position:0% +who can comment on what what will + + + align:start position:0% +who can comment on what what will +change Dan I'm a little confused why + + align:start position:0% +change Dan I'm a little confused why + + + align:start position:0% +change Dan I'm a little confused why +wouldn't you put a constraint on the + + align:start position:0% +wouldn't you put a constraint on the + + + align:start position:0% +wouldn't you put a constraint on the +risk free asset could you do that as + + align:start position:0% +risk free asset could you do that as + + + align:start position:0% +risk free asset could you do that as +well or + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% +um + + + align:start position:0% +um +well the risk- free asset has no + + align:start position:0% +well the risk- free asset has no + + + align:start position:0% +well the risk- free asset has no +risk and so + + align:start position:0% +risk and so + + + align:start position:0% +risk and so +um putting a constraint well you could + + align:start position:0% +um putting a constraint well you could + + + align:start position:0% +um putting a constraint well you could +put a constraint on it in terms of it + + align:start position:0% +put a constraint on it in terms of it + + + align:start position:0% +put a constraint on it in terms of it +not going negative and it not being + + align:start position:0% +not going negative and it not being + + + align:start position:0% +not going negative and it not being +greater than one so in fact that is a + + align:start position:0% +greater than one so in fact that is a + + + align:start position:0% +greater than one so in fact that is a +constraint those are constraints that + + align:start position:0% +constraint those are constraints that + + + align:start position:0% +constraint those are constraints that +are imposed + + align:start position:0% + + + + align:start position:0% + +here but um but and I guess in some well + + align:start position:0% +here but um but and I guess in some well + + + align:start position:0% +here but um but and I guess in some well +there are like uh I guess endowments say + + align:start position:0% +there are like uh I guess endowments say + + + align:start position:0% +there are like uh I guess endowments say +that have investment policies that say + + align:start position:0% +that have investment policies that say + + + align:start position:0% +that have investment policies that say +that they want a certain fraction of + + align:start position:0% +that they want a certain fraction of + + + align:start position:0% +that they want a certain fraction of +their assets invested in Risky assets + + align:start position:0% +their assets invested in Risky assets + + + align:start position:0% +their assets invested in Risky assets +and not in cash and so that you know is + + align:start position:0% +and not in cash and so that you know is + + + align:start position:0% +and not in cash and so that you know is +is uh is a realistic constraint in + + align:start position:0% +is uh is a realistic constraint in + + + align:start position:0% +is uh is a realistic constraint in +certain circumstances and this is just + + align:start position:0% +certain circumstances and this is just + + + align:start position:0% +certain circumstances and this is just +highlighting you + + align:start position:0% +highlighting you + + + align:start position:0% +highlighting you +know the how the allocations vary across + + align:start position:0% +know the how the allocations vary across + + + align:start position:0% +know the how the allocations vary across +the risky assets if if we only have very + + align:start position:0% +the risky assets if if we only have very + + + align:start position:0% +the risky assets if if we only have very +simple constraints on on the cash + + align:start position:0% +simple constraints on on the cash + + + align:start position:0% +simple constraints on on the cash +investment + + align:start position:0% +investment + + + align:start position:0% +investment +well the question I want to focus on is + + align:start position:0% +well the question I want to focus on is + + + align:start position:0% +well the question I want to focus on is +what happens if we make these the + + align:start position:0% +what happens if we make these the + + + align:start position:0% +what happens if we make these the +maximum allocation constraint more + + align:start position:0% +maximum allocation constraint more + + + align:start position:0% +maximum allocation constraint more +severe so it's 15% instead of 30 then + + align:start position:0% +severe so it's 15% instead of 30 then + + + align:start position:0% +severe so it's 15% instead of 30 then +what's going to happen + + align:start position:0% +what's going to happen + + + align:start position:0% +what's going to happen +is + + align:start position:0% +is + + + align:start position:0% +is +the these these Capital constraints are + + align:start position:0% +the these these Capital constraints are + + + align:start position:0% +the these these Capital constraints are +going going to start hitting sooner so + + align:start position:0% +going going to start hitting sooner so + + + align:start position:0% +going going to start hitting sooner so +we have to allocate to + + align:start position:0% +we have to allocate to + + + align:start position:0% +we have to allocate to +more uh to the other exchange traded + + align:start position:0% +more uh to the other exchange traded + + + align:start position:0% +more uh to the other exchange traded +funds so let me show you how that works + + align:start position:0% +funds so let me show you how that works + + + align:start position:0% +funds so let me show you how that works +out with the same + + align:start position:0% + + + + align:start position:0% + +graph let's + + align:start position:0% + + + + align:start position:0% + +see all + + align:start position:0% + + + + align:start position:0% + +right okay let me just close that and + + align:start position:0% +right okay let me just close that and + + + align:start position:0% +right okay let me just close that and +then me go here + + align:start position:0% + + + + align:start position:0% + +okay this shows let see with a 50% + + align:start position:0% +okay this shows let see with a 50% + + + align:start position:0% +okay this shows let see with a 50% +allocation how how the allocations + + align:start position:0% +allocation how how the allocations + + + align:start position:0% +allocation how how the allocations +vary and uh I'll I'll be posting this on + + align:start position:0% +vary and uh I'll I'll be posting this on + + + align:start position:0% +vary and uh I'll I'll be posting this on +the course website um but uh turns out + + align:start position:0% +the course website um but uh turns out + + + align:start position:0% +the course website um but uh turns out +the efficient Frontier is actually lower + + align:start position:0% +the efficient Frontier is actually lower + + + align:start position:0% +the efficient Frontier is actually lower +basically we you know for higher returns + + align:start position:0% +basically we you know for higher returns + + + align:start position:0% +basically we you know for higher returns +we actually can't get those higher + + align:start position:0% +we actually can't get those higher + + + align:start position:0% +we actually can't get those higher +returns from by giving the getting the + + align:start position:0% +returns from by giving the getting the + + + align:start position:0% +returns from by giving the getting the +biggest bang for the buck we don't want + + align:start position:0% +biggest bang for the buck we don't want + + + align:start position:0% +biggest bang for the buck we don't want +to allocate too much to those higher + + align:start position:0% +to allocate too much to those higher + + + align:start position:0% +to allocate too much to those higher +return higher risk Securities and so the + + align:start position:0% +return higher risk Securities and so the + + + align:start position:0% +return higher risk Securities and so the +uh optimal uh the efficient Frontier as + + align:start position:0% +uh optimal uh the efficient Frontier as + + + align:start position:0% +uh optimal uh the efficient Frontier as +estimated uh basically slopes down um + + align:start position:0% + + + + align:start position:0% + +now just uh okay as an ex okay with with + + align:start position:0% +now just uh okay as an ex okay with with + + + align:start position:0% +now just uh okay as an ex okay with with +this particular example of these uh + + align:start position:0% +this particular example of these uh + + + align:start position:0% +this particular example of these uh +exchange traded funds and how You' + + align:start position:0% +exchange traded funds and how You' + + + align:start position:0% +exchange traded funds and how You' +allocate across those um you know this + + align:start position:0% +allocate across those um you know this + + + align:start position:0% +allocate across those um you know this +provides some insight into portfolio IO + + align:start position:0% +provides some insight into portfolio IO + + + align:start position:0% +provides some insight into portfolio IO +optimization it's not really a realistic + + align:start position:0% +optimization it's not really a realistic + + + align:start position:0% +optimization it's not really a realistic +setting because we're looking over the + + align:start position:0% +setting because we're looking over the + + + align:start position:0% +setting because we're looking over the +past and using the actual sample + + align:start position:0% +past and using the actual sample + + + align:start position:0% +past and using the actual sample +performance to Define these + + align:start position:0% +performance to Define these + + + align:start position:0% +performance to Define these +portfolios um let me just highlight a an + + align:start position:0% +portfolios um let me just highlight a an + + + align:start position:0% +portfolios um let me just highlight a an +example of applying these kinds of + + align:start position:0% +example of applying these kinds of + + + align:start position:0% +example of applying these kinds of +methods with + + align:start position:0% +methods with + + + align:start position:0% +methods with +um let's see is it + + align:start position:0% +um let's see is it + + + align:start position:0% +um let's see is it +here yeah okay + + align:start position:0% + + + + align:start position:0% + +let's see is that the right + + align:start position:0% + + + + align:start position:0% + +graph yeah okay okay suppose we + + align:start position:0% +graph yeah okay okay suppose we + + + align:start position:0% +graph yeah okay okay suppose we +uh consider not investing in exchange + + align:start position:0% +uh consider not investing in exchange + + + align:start position:0% +uh consider not investing in exchange +traded funds but we are a a hedge fund + + align:start position:0% +traded funds but we are a a hedge fund + + + align:start position:0% +traded funds but we are a a hedge fund +and we have uh sector pricing models + + align:start position:0% +and we have uh sector pricing models + + + align:start position:0% +and we have uh sector pricing models +across all all these different sectors + + align:start position:0% +across all all these different sectors + + + align:start position:0% +across all all these different sectors +and what we can do is consider in going + + align:start position:0% +and what we can do is consider in going + + + align:start position:0% +and what we can do is consider in going +long short in these + + align:start position:0% +long short in these + + + align:start position:0% +long short in these +sectors and in fact we consider sort of + + align:start position:0% +sectors and in fact we consider sort of + + + align:start position:0% +sectors and in fact we consider sort of +a sort of a a market neutral strategy + + align:start position:0% +a sort of a a market neutral strategy + + + align:start position:0% +a sort of a a market neutral strategy +sector by sector and consider + + align:start position:0% +sector by sector and consider + + + align:start position:0% +sector by sector and consider +investing uh in in the sector by sector + + align:start position:0% +investing uh in in the sector by sector + + + align:start position:0% +investing uh in in the sector by sector +in these different sector-based models + + align:start position:0% +in these different sector-based models + + + align:start position:0% +in these different sector-based models +okay here's a graph of different + + align:start position:0% +okay here's a graph of different + + + align:start position:0% +okay here's a graph of different +multiactor pricing models for trading + + align:start position:0% +multiactor pricing models for trading + + + align:start position:0% +multiactor pricing models for trading +Market neutral programs within each of + + align:start position:0% +Market neutral programs within each of + + + align:start position:0% +Market neutral programs within each of +uh nine industrial sectors the same ones + + align:start position:0% +uh nine industrial sectors the same ones + + + align:start position:0% +uh nine industrial sectors the same ones +corresponding to the exchange traded + + align:start position:0% +corresponding to the exchange traded + + + align:start position:0% +corresponding to the exchange traded +funds and uh okay because the these + + align:start position:0% +funds and uh okay because the these + + + align:start position:0% +funds and uh okay because the these +strategies are Market neutral the sort + + align:start position:0% +strategies are Market neutral the sort + + + align:start position:0% +strategies are Market neutral the sort +of total returns over this is a 5-year + + align:start position:0% +of total returns over this is a 5-year + + + align:start position:0% +of total returns over this is a 5-year +period um are rather + + align:start position:0% +period um are rather + + + align:start position:0% +period um are rather +modest namely uh you know sort of 60% + + align:start position:0% +modest namely uh you know sort of 60% + + + align:start position:0% +modest namely uh you know sort of 60% +for some of the models 20% for other + + align:start position:0% +for some of the models 20% for other + + + align:start position:0% +for some of the models 20% for other +models + + align:start position:0% + + + + align:start position:0% + +what's particularly uh relevant with + + align:start position:0% +what's particularly uh relevant with + + + align:start position:0% +what's particularly uh relevant with +these models though is that they tend to + + align:start position:0% +these models though is that they tend to + + + align:start position:0% +these models though is that they tend to +be less correlated and um the + + align:start position:0% +be less correlated and um the + + + align:start position:0% +be less correlated and um the +diversification benefits can be rather + + align:start position:0% +diversification benefits can be rather + + + align:start position:0% +diversification benefits can be rather +dramatic and so here is a graph of the + + align:start position:0% +dramatic and so here is a graph of the + + + align:start position:0% +dramatic and so here is a graph of the +optimal allocations across these + + align:start position:0% +optimal allocations across these + + + align:start position:0% +optimal allocations across these +different sector uh Market neutral + + align:start position:0% +different sector uh Market neutral + + + align:start position:0% +different sector uh Market neutral +models and we can see that this red + + align:start position:0% +models and we can see that this red + + + align:start position:0% +models and we can see that this red +model is getting a lot lot of weight + + align:start position:0% +model is getting a lot lot of weight + + + align:start position:0% +model is getting a lot lot of weight +that actually is uh the utility sector + + align:start position:0% +that actually is uh the utility sector + + + align:start position:0% +that actually is uh the utility sector +and then these other models are uh + + align:start position:0% +and then these other models are uh + + + align:start position:0% +and then these other models are uh +Industrials and + + align:start position:0% +Industrials and + + + align:start position:0% +Industrials and +uh let's see Industrials and + + align:start position:0% +uh let's see Industrials and + + + align:start position:0% +uh let's see Industrials and +energy + + align:start position:0% +energy + + + align:start position:0% +energy +um and so if we + + align:start position:0% +um and so if we + + + align:start position:0% +um and so if we +consider investing in these + + align:start position:0% + + + + align:start position:0% + +we can actually + + align:start position:0% +we can actually + + + align:start position:0% +we can actually +achieve uh with a Target volatility of + + align:start position:0% +achieve uh with a Target volatility of + + + align:start position:0% +achieve uh with a Target volatility of +10% we're can achieve this solid blue + + align:start position:0% +10% we're can achieve this solid blue + + + align:start position:0% +10% we're can achieve this solid blue +line as as the portfolio strategy and + + align:start position:0% +line as as the portfolio strategy and + + + align:start position:0% +line as as the portfolio strategy and +one can see how by combining these + + align:start position:0% +one can see how by combining these + + + align:start position:0% +one can see how by combining these +assets together these assets are + + align:start position:0% +assets together these assets are + + + align:start position:0% +assets together these assets are +different uh uh Market neutral trading + + align:start position:0% +different uh uh Market neutral trading + + + align:start position:0% +different uh uh Market neutral trading +models um we actually get uh quite a bit + + align:start position:0% +models um we actually get uh quite a bit + + + align:start position:0% +models um we actually get uh quite a bit +of benefit from the portfolio + + align:start position:0% +of benefit from the portfolio + + + align:start position:0% +of benefit from the portfolio +optimization and the greater benefit and + + align:start position:0% +optimization and the greater benefit and + + + align:start position:0% +optimization and the greater benefit and +the portfolio optimization is because + + align:start position:0% +the portfolio optimization is because + + + align:start position:0% +the portfolio optimization is because +these uh strategies tend to be uh have + + align:start position:0% +these uh strategies tend to be uh have + + + align:start position:0% +these uh strategies tend to be uh have +much lower correlations with each other + + align:start position:0% +much lower correlations with each other + + + align:start position:0% +much lower correlations with each other +and uh it's adding value let's go back + + align:start position:0% +and uh it's adding value let's go back + + + align:start position:0% +and uh it's adding value let's go back +now finish up + + align:start position:0% + + + + align:start position:0% + +with how do we how do we go back here + + align:start position:0% +with how do we how do we go back here + + + align:start position:0% +with how do we how do we go back here +where's my Red + + align:start position:0% + + + + align:start position:0% + +Dot okay + + align:start position:0% + + + + align:start position:0% + +let's okay + + align:start position:0% + + + + align:start position:0% + +okay just to finish up the + + align:start position:0% + + + + align:start position:0% + +discussion um with these methods um it's + + align:start position:0% +discussion um with these methods um it's + + + align:start position:0% +discussion um with these methods um it's +important to highlight that you know + + align:start position:0% +important to highlight that you know + + + align:start position:0% +important to highlight that you know +what we've been using we're estimated + + align:start position:0% +what we've been using we're estimated + + + align:start position:0% +what we've been using we're estimated +returns estimated volatilities and + + align:start position:0% +returns estimated volatilities and + + + align:start position:0% +returns estimated volatilities and +correlations and these estimates can + + align:start position:0% +correlations and these estimates can + + + align:start position:0% +correlations and these estimates can +have a huge impact on on the results um + + align:start position:0% +have a huge impact on on the results um + + + align:start position:0% +have a huge impact on on the results um +there's basically choices of estimation + + align:start position:0% +there's basically choices of estimation + + + align:start position:0% +there's basically choices of estimation +period there's estimation error uh + + align:start position:0% +period there's estimation error uh + + + align:start position:0% +period there's estimation error uh +different techniques can uh modulate + + align:start position:0% +different techniques can uh modulate + + + align:start position:0% +different techniques can uh modulate +these these issues uh exponential moving + + align:start position:0% +these these issues uh exponential moving + + + align:start position:0% +these these issues uh exponential moving +average are often applied having Dynamic + + align:start position:0% +average are often applied having Dynamic + + + align:start position:0% +average are often applied having Dynamic +Factor models is is used um basically + + align:start position:0% +Factor models is is used um basically + + + align:start position:0% +Factor models is is used um basically +rather than using sample estimates of + + align:start position:0% +rather than using sample estimates of + + + align:start position:0% +rather than using sample estimates of +the variance co-variance Matrix using + + align:start position:0% +the variance co-variance Matrix using + + + align:start position:0% +the variance co-variance Matrix using +Factor models to estimate the variance + + align:start position:0% +Factor models to estimate the variance + + + align:start position:0% +Factor models to estimate the variance +co-variance Matrix um results in uh more + + align:start position:0% +co-variance Matrix um results in uh more + + + align:start position:0% +co-variance Matrix um results in uh more +precise + + align:start position:0% +precise + + + align:start position:0% +precise +uh inputs to to the + + align:start position:0% +uh inputs to to the + + + align:start position:0% +uh inputs to to the +optimization um and finally just with uh + + align:start position:0% +optimization um and finally just with uh + + + align:start position:0% +optimization um and finally just with uh +different risk measures we've been + + align:start position:0% +different risk measures we've been + + + align:start position:0% +different risk measures we've been +focusing on portfolio volatility and + + align:start position:0% +focusing on portfolio volatility and + + + align:start position:0% +focusing on portfolio volatility and +minimizing that the methodologies can be + + align:start position:0% +minimizing that the methodologies can be + + + align:start position:0% +minimizing that the methodologies can be +extended to have different measures of + + align:start position:0% +extended to have different measures of + + + align:start position:0% +extended to have different measures of +risk mean absolute deviation for example + + align:start position:0% +risk mean absolute deviation for example + + + align:start position:0% +risk mean absolute deviation for example +or + + align:start position:0% +or + + + align:start position:0% +or +semivariance um in terms of you know the + + align:start position:0% +semivariance um in terms of you know the + + + align:start position:0% +semivariance um in terms of you know the +motivation for squared volatility + + align:start position:0% +motivation for squared volatility + + + align:start position:0% +motivation for squared volatility +minimizing that you'll recall that in + + align:start position:0% +minimizing that you'll recall that in + + + align:start position:0% +minimizing that you'll recall that in +likelihood analysis of gaussing + + align:start position:0% +likelihood analysis of gaussing + + + align:start position:0% +likelihood analysis of gaussing +distributions the sort of square + + align:start position:0% +distributions the sort of square + + + align:start position:0% +distributions the sort of square +deviations from the means are + + align:start position:0% +deviations from the means are + + + align:start position:0% +deviations from the means are +characterizing variability well if we + + align:start position:0% +characterizing variability well if we + + + align:start position:0% +characterizing variability well if we +focus on mean absolute deviation then + + align:start position:0% +focus on mean absolute deviation then + + + align:start position:0% +focus on mean absolute deviation then +probability distributions that where the + + align:start position:0% +probability distributions that where the + + + align:start position:0% +probability distributions that where the +distributions relate to the absolute + + align:start position:0% +distributions relate to the absolute + + + align:start position:0% +distributions relate to the absolute +deviation from the mean characterizing + + align:start position:0% +deviation from the mean characterizing + + + align:start position:0% +deviation from the mean characterizing +the distribution might be appropriate + + align:start position:0% +the distribution might be appropriate + + + align:start position:0% +the distribution might be appropriate +and indeed uh distributions with heavier + + align:start position:0% +and indeed uh distributions with heavier + + + align:start position:0% +and indeed uh distributions with heavier +Tails like exponential + + align:start position:0% +Tails like exponential + + + align:start position:0% +Tails like exponential +distributions uh basically are + + align:start position:0% +distributions uh basically are + + + align:start position:0% +distributions uh basically are +appropriate when we consider mean + + align:start position:0% +appropriate when we consider mean + + + align:start position:0% +appropriate when we consider mean +absolute deviation so um some alternate + + align:start position:0% +absolute deviation so um some alternate + + + align:start position:0% +absolute deviation so um some alternate +risk measures are appropriate when the + + align:start position:0% +risk measures are appropriate when the + + + align:start position:0% +risk measures are appropriate when the +volatility measure itself isn't um + + align:start position:0% +volatility measure itself isn't um + + + align:start position:0% +volatility measure itself isn't um +necessarily appropriate because of the + + align:start position:0% +necessarily appropriate because of the + + + align:start position:0% +necessarily appropriate because of the +the distributional assumptions uh + + align:start position:0% +the distributional assumptions uh + + + align:start position:0% +the distributional assumptions uh +semivariance was introduced actually by + + align:start position:0% +semivariance was introduced actually by + + + align:start position:0% +semivariance was introduced actually by +marwitz uh where you're interested in + + align:start position:0% +marwitz uh where you're interested in + + + align:start position:0% +marwitz uh where you're interested in +controlling the downside risk as opposed + + align:start position:0% +controlling the downside risk as opposed + + + align:start position:0% +controlling the downside risk as opposed +to the upside risk um and uh there's + + align:start position:0% +to the upside risk um and uh there's + + + align:start position:0% +to the upside risk um and uh there's +value at risk meas measures which are + + align:start position:0% +value at risk meas measures which are + + + align:start position:0% +value at risk meas measures which are +now completely standard in uh portfolio + + align:start position:0% +now completely standard in uh portfolio + + + align:start position:0% +now completely standard in uh portfolio +management and uh management of uh risky + + align:start position:0% +management and uh management of uh risky + + + align:start position:0% +management and uh management of uh risky +assets um + + align:start position:0% +assets um + + + align:start position:0% +assets um +where one is actually well this was + + align:start position:0% +where one is actually well this was + + + align:start position:0% +where one is actually well this was +introduced by Ken Abbott in one of the + + align:start position:0% +introduced by Ken Abbott in one of the + + + align:start position:0% +introduced by Ken Abbott in one of the +first few lectures uh value at risk is + + align:start position:0% +first few lectures uh value at risk is + + + align:start position:0% +first few lectures uh value at risk is +basically a very simple idea of + + align:start position:0% +basically a very simple idea of + + + align:start position:0% +basically a very simple idea of +characterizing what outcome is uh sort + + align:start position:0% +characterizing what outcome is uh sort + + + align:start position:0% +characterizing what outcome is uh sort +of the threshold of extreme at say the + + align:start position:0% +of the threshold of extreme at say the + + + align:start position:0% +of the threshold of extreme at say the +5% level or the 1% level and to + + align:start position:0% +5% level or the 1% level and to + + + align:start position:0% +5% level or the 1% level and to +basically keep a monitor of that the + + align:start position:0% +basically keep a monitor of that the + + + align:start position:0% +basically keep a monitor of that the +value at risk so if we had a risk that + + align:start position:0% +value at risk so if we had a risk that + + + align:start position:0% +value at risk so if we had a risk that +was you know basically in the worst 5% + + align:start position:0% +was you know basically in the worst 5% + + + align:start position:0% +was you know basically in the worst 5% +or 1% of the time what is that level + + align:start position:0% +or 1% of the time what is that level + + + align:start position:0% +or 1% of the time what is that level +that's the value at risk um that as a + + align:start position:0% +that's the value at risk um that as a + + + align:start position:0% +that's the value at risk um that as a +nice risk measure is um simple to Define + + align:start position:0% +nice risk measure is um simple to Define + + + align:start position:0% +nice risk measure is um simple to Define +but and and reasonably simple to to + + align:start position:0% +but and and reasonably simple to to + + + align:start position:0% +but and and reasonably simple to to +estimate but um it doesn't characterize + + align:start position:0% +estimate but um it doesn't characterize + + + align:start position:0% +estimate but um it doesn't characterize +sort of what the potential exposure is + + align:start position:0% +sort of what the potential exposure is + + + align:start position:0% +sort of what the potential exposure is +if you exceed that and there are + + align:start position:0% +if you exceed that and there are + + + align:start position:0% +if you exceed that and there are +extensions of that the conditional value + + align:start position:0% +extensions of that the conditional value + + + align:start position:0% +extensions of that the conditional value +at risk which is looking at the expected + + align:start position:0% +at risk which is looking at the expected + + + align:start position:0% +at risk which is looking at the expected +loss given that you exceed the value + + align:start position:0% +loss given that you exceed the value + + + align:start position:0% +loss given that you exceed the value +risk threshold and uh this method is now + + align:start position:0% +risk threshold and uh this method is now + + + align:start position:0% +risk threshold and uh this method is now +uh I I think it's being going to be + + align:start position:0% +uh I I think it's being going to be + + + align:start position:0% +uh I I think it's being going to be +incorporated into uh regulatory uh uh + + align:start position:0% +incorporated into uh regulatory uh uh + + + align:start position:0% +incorporated into uh regulatory uh uh +requirements for for banks in terms of + + align:start position:0% +requirements for for banks in terms of + + + align:start position:0% +requirements for for banks in terms of +how they measure risk right now I + + align:start position:0% +how they measure risk right now I + + + align:start position:0% +how they measure risk right now I +believe it's almost all value at risk uh + + align:start position:0% +believe it's almost all value at risk uh + + + align:start position:0% +believe it's almost all value at risk uh +extensions but this uh conditional value + + align:start position:0% +extensions but this uh conditional value + + + align:start position:0% +extensions but this uh conditional value +risk is is definitely going to be uh + + align:start position:0% +risk is is definitely going to be uh + + + align:start position:0% +risk is is definitely going to be uh +applied um and in the discussion of + + align:start position:0% +applied um and in the discussion of + + + align:start position:0% +applied um and in the discussion of +different risk measures there's + + align:start position:0% +different risk measures there's + + + align:start position:0% +different risk measures there's +literature talking about what are + + align:start position:0% +literature talking about what are + + + align:start position:0% +literature talking about what are +appropriate risk measures and how how do + + align:start position:0% +appropriate risk measures and how how do + + + align:start position:0% +appropriate risk measures and how how do +we Define those + + align:start position:0% +we Define those + + + align:start position:0% +we Define those +well you know it really depends on what + + align:start position:0% +well you know it really depends on what + + + align:start position:0% +well you know it really depends on what +your assets are and if you your assets + + align:start position:0% +your assets are and if you your assets + + + align:start position:0% +your assets are and if you your assets +are simply + + align:start position:0% +are simply + + + align:start position:0% +are simply +simple investments in stocks or bonds + + align:start position:0% +simple investments in stocks or bonds + + + align:start position:0% +simple investments in stocks or bonds +sort of cash assets or you know uh cash + + align:start position:0% +sort of cash assets or you know uh cash + + + align:start position:0% +sort of cash assets or you know uh cash +cash instruments then uh value at risk + + align:start position:0% +cash instruments then uh value at risk + + + align:start position:0% +cash instruments then uh value at risk +is quite reasonable if you're investing + + align:start position:0% +is quite reasonable if you're investing + + + align:start position:0% +is quite reasonable if you're investing +in derivatives which have nonlinear + + align:start position:0% +in derivatives which have nonlinear + + + align:start position:0% +in derivatives which have nonlinear +payoffs then things get complicated and + + align:start position:0% +payoffs then things get complicated and + + + align:start position:0% +payoffs then things get complicated and +so + + align:start position:0% +so + + + align:start position:0% +so +um things basically need to be handled + + align:start position:0% +um things basically need to be handled + + + align:start position:0% +um things basically need to be handled +on on a case-by Case basis there but uh + + align:start position:0% +on on a case-by Case basis there but uh + + + align:start position:0% +on on a case-by Case basis there but uh +but if you're interested in in Risk + + align:start position:0% +but if you're interested in in Risk + + + align:start position:0% +but if you're interested in in Risk +analysis there's a whole discussion on + + align:start position:0% +analysis there's a whole discussion on + + + align:start position:0% +analysis there's a whole discussion on +coherent risk measures that uh uh you + + align:start position:0% +coherent risk measures that uh uh you + + + align:start position:0% +coherent risk measures that uh uh you +you can you can look into that's quite + + align:start position:0% +you can you can look into that's quite + + + align:start position:0% +you can you can look into that's quite +interesting all right let's stop there + + align:start position:0% +interesting all right let's stop there + + + align:start position:0% +interesting all right let's stop there +thank you \ No newline at end of file diff --git a/z6kTOFSZZmQ.txt b/z6kTOFSZZmQ.txt new file mode 100644 index 0000000000000000000000000000000000000000..0e3917f0fbeb1eec5712364984ada5fab863f9b2 --- /dev/null +++ b/z6kTOFSZZmQ.txt @@ -0,0 +1,163 @@ +align:start position:0% + +my name is Michel de Graaff and I've + + align:start position:0% +my name is Michel de Graaff and I've + + + align:start position:0% +my name is Michel de Graaff and I've +been teaching in linguistics at MIT for + + align:start position:0% +been teaching in linguistics at MIT for + + + align:start position:0% +been teaching in linguistics at MIT for +the past 21 years already and I'm the + + align:start position:0% +the past 21 years already and I'm the + + + align:start position:0% +the past 21 years already and I'm the +faculty instructor for the course on + + align:start position:0% +faculty instructor for the course on + + + align:start position:0% +faculty instructor for the course on +clear languages and Caribbean identities + + align:start position:0% +clear languages and Caribbean identities + + + align:start position:0% +clear languages and Caribbean identities +so my research is about trying to + + align:start position:0% +so my research is about trying to + + + align:start position:0% +so my research is about trying to +understand how languages evolve over + + align:start position:0% +understand how languages evolve over + + + align:start position:0% +understand how languages evolve over +time and what happens when new languages + + align:start position:0% +time and what happens when new languages + + + align:start position:0% +time and what happens when new languages +are created say for example the + + align:start position:0% +are created say for example the + + + align:start position:0% +are created say for example the +Caribbean in magnitude Haiti where + + align:start position:0% +Caribbean in magnitude Haiti where + + + align:start position:0% +Caribbean in magnitude Haiti where +Haitian Creole emerged in the seventeen + + align:start position:0% +Haitian Creole emerged in the seventeen + + + align:start position:0% +Haitian Creole emerged in the seventeen +eighteenth century so we try to + + align:start position:0% +eighteenth century so we try to + + + align:start position:0% +eighteenth century so we try to +understand the patterns of development + + align:start position:0% +understand the patterns of development + + + align:start position:0% +understand the patterns of development +of the things that we call Creole + + align:start position:0% +of the things that we call Creole + + + align:start position:0% +of the things that we call Creole +languages and in terms of the structure + + align:start position:0% +languages and in terms of the structure + + + align:start position:0% +languages and in terms of the structure +but also have an applied side to my work + + align:start position:0% +but also have an applied side to my work + + + align:start position:0% +but also have an applied side to my work +where I try to understand how best to + + align:start position:0% +where I try to understand how best to + + + align:start position:0% +where I try to understand how best to +use say Haitian Creole and other local + + align:start position:0% +use say Haitian Creole and other local + + + align:start position:0% +use say Haitian Creole and other local +languages in education and how that's + + align:start position:0% +languages in education and how that's + + + align:start position:0% +languages in education and how that's +crucial for development of countries + + align:start position:0% +crucial for development of countries + + + align:start position:0% +crucial for development of countries +like Haiti \ No newline at end of file diff --git a/zB9aY8tzd74.txt b/zB9aY8tzd74.txt new file mode 100644 index 0000000000000000000000000000000000000000..8191145680dd4790b20980f5fe3d88021f29fff5 --- /dev/null +++ b/zB9aY8tzd74.txt @@ -0,0 +1,3693 @@ +The following content is +provided under a Creative + +Commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high quality educational +resources for free. + +To make a donation or to view +additional materials from + +hundreds of MIT courses, visit +MIT OpenCourseWare at + +OCW.MIT.edu. + +PROFESSOR: OK. + +We are talking about jointly +Gaussian random variables. + +One comment through all of this +and through all of the + +notes is that you can add a +mean to Gaussian random + +variables, or you +can talk about + +zero-mean random variables. + +Here we're using random +variables mostly + +to talk about noise. + +When we're talking about noise, +you really should be + +talking about zero-mean random +variables, because you can + +always take the mean out. + +And because of that, I don't +like to state everything twice + +once for variables of processes +without a mean, and + +once for variables of processes +with a mean. + +And after looking at the notes, +I think I've been a + +little inconsistent +about that. + +I think the point is you can +keep yourself straight by just + +saying the only thing +important is the + +case without a mean. + +Putting the mean in is something +unfortunately done + +by people who like complexity. + +And they have unfortunately +got in the + +notation on their side. + +So anytime you want +to talk about a + +zero-mean random variable. + +You have to say zero-mean +random variable. + +And if you say random variable, +it means it could + +have a mean or not +have a mean. + +And of course the way the +notation should be stated is + +you talk about random variables +as things which + +don't have means. + +And then you can talk about +random variables plus means as + +things which do have means, +which would make life easier + +but unfortunately it's +not that way. + +So anytime you see something +and are wondering about + +whether I've been careful about +the mean or not, the + +answer is I well might +not have been. + +And two, it's not +very important. + +So anyway. + +Here I'll be talking all +about zero-mean things. + +A k-tuple of zero-mean random +variables is said to be + +jointly Gaussian if you can +express them in this way here. + +Namely as a linear combination +of IID normal Gaussian again + +random variables. + +OK. + +In your homework, those of you +who've done it already, have + +realized that just having two +Gaussian random variables is + +not enough to make +those two random + +variables be jointly Gaussian. + +They can be individually +Gaussian + +but not jointly Gaussian. + +This is sort of important +because when you start + +manipulating things as we will +do when we're generating + +signals to send and things like +this, you can very easily + +wind up with things which look +Gaussian and are appropriately + +modeled as Gaussian, but which +are not jointly Gaussian. + +Things which are jointly +Gaussian are + +defined in this way. + +We will come up with +a couple of other + +definitions of them later. + +But you've undoubtedly been +taught that any old Gaussian + +random variables are +jointly Gaussian. + +You've probably seen joint +densities for them + +and things like this. + +Those joint densities only apply +when you have jointly + +Gaussian random variables. + +And the fundamental definition +is this. + +This fundamental definition +makes sense, because the way + +that you generate these noise +random variables is usually + +from some very large underlying +set of very, very + +small random variables. + +And the Law of Large Numbers +says that when you add up a + +very, very large number of +small underlying random + +variables, you normalize the sum +so it has some reasonable + +variance then that random +variable is going to be + +appropriately modeled +as being Gaussian. + +If you at the same time look +at linear combinations of + +those things for the same +reason, it's appropriate to + +model each of the random +variables you're looking at as + +a linear combination of some +underlying set of noise + +variables which is +very, very large. + +Probably not Gaussian. + +But here when we're trying to +do this, because of the + +central limit theorem, we just +model these as normal Gaussian + +random variables +to start with. + +So that's where that definition +comes from. + +It's why when you're looking at +noise processes in the real + +world, and trying to model them +in a sensible way this + +jointly Gaussian is the +thing you almost + +always come up with. + +OK. + +So one important point here, and +the notes point this out. + +If each of these random +variables Z sub i is + +independent of each of the +others, and they have + +arbitrary variances, then +because of this formula, the + +set of Z i's are going to +be jointly Gaussian. + +Why is that? + +Well you simply make a matrix +here A, which is diagonal. + +And the elements of this +diagonal matrix are sigma 1 + +squared, sigma 2 squared, sigma +3 squared, and so forth. + +If you have a vector Z, which +is then sigma 1 squared down + +to sigma k squared times a noise +vector N1 to N sub k. + +What you wind up with is Z sub +i is going to be equal to -- + +I guess I don't want those +squares in there. + +Sigma 1 up to sigma k -- + +Z sub i is going to be equal to +sigma i, N sub i; N sub i + +is a Gaussian random variable +with variance one and + +therefore Z sub i as Gaussian +random variable with variance + +sigma sub i squared. + +OK. + +So anyway, one special case of +this formula is anytime that + +you want to deal with a set of +independent Gaussian random + +variables with arbitrary +variances, they are always + +going to be jointly Gaussian. + +Saying that they're +uncorrelated is + +not enough for that. + +You really need the statement +that they're independent of + +each other. + +OK. + +That's sort of where +we were last time. + +When you look at this formula, +you can look at it in terms of + +sample values. + +And if we look at a sample value +what's happening is that + +the sample value of the random +vector Z, namely little z, is + +going to be defined as some +matrix A times this sample + +value for the normal +vector N. OK. + +And what we want to look +at is geometrically + +what happens there. + +Well this matrix a is going to +map a unit vector, E sub i + +into the i'th column +of A. Why is that? + +Well you look at A, which is +whatever it is, A sub 1, 1, + +blah, blah, blah up +to A sub k, k. + +And you look at multiplying it +by a vector which is zero only + +in the i'th position. + +And what's this matrix +multiplication going to do? + +It's going to simply pick +out the i'th column + +of this matrix here. + +OK. + +So a is going to map e sub i +into the i'th column of A. OK. + +So then the question is what is +this matrix A going to do + +to some small cube +in the n plane? + +OK. + +If you take a small cube in the +n plane from 0 to delta + +along the n1 line is going to +map into 0 to this point here, + +which is A e sub 1. + +This point here is going to +map into A times e sub 2. + +This is just drawing for two +dimensions of course. + +So in fact all the points in +this cube are going to get map + +into this little +rectangle here. + +OK. + +Namely, that's what a matrix +times a vector is going to do. + +Anybody awake out there? + +You're all looking at me as +if I'm totally insane. + +OK. + +Every everyone following this? + +OK. + +So perhaps this is +just too trivial. + +I hope not. + +OK. + +So unit cubes get mapped +into rectangles here. + +If I take a unit cube up here, +it's going to get mapped into + +the same kind of unit +rectangle here. + +If I visualize tiling this plane +here with little tiny + +cubes, delta on a side, what's +going to happen? + +Each of these little cubes +is going to map into a + +parallelogram over here, and +these parallelograms going to + +tile this space here. + +OK. + +Which means that each little +cube here maps into one of + +these rectangles. + +Each rectangle here maps back +into a little cube here. + +Which means that I'm +looking at a very + +special case of a here. + +I'm looking at a case where +a is non-singular. + +In other words, I can get the +any point in this plane by + +starting with some point +in this plane. + +Which means for any point here, +I can go back here also. + +In other words, I can also write +n is equal to A to the + +minus 1 times Z. And this +matrix has to exist. + +OK. + +That's what you mean +geometrically by a + +non-singular matrix. + +It means that all points in +this plane get mapped into + +points in this plane. + +And get mapped into only one +point in this plane, and get + +mapped into only one point +in this plane. + +Where every point in this +plane is the map + +of some point here. + +In other words you can go +from here to there. + +You can also go back again. + +OK. + +The volume of a parallelepiped +here, and this is in an + +arbitrary number of dimensions +is going to be the determinant + +of A. And you all know how +to find determinants. + +Namely you program a computer +to do it, and the + +computer does it. + +I mean it used to be we had to +do this by an enormous amount + +of calculation. + +And of course nobody +does that anymore. + +OK. + +So we can find the volume of +this parallelepiped, it's this + +determinant. + +And what does all +of that mean? + +Well first let me ask +you the question. + +What's going to happen if +the determinant of a + +is equaled to zero? + +What does that mean +geometrically? + +What does that mean here +in terms of this + +two dimensional diagram? + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: What? + +AUDIENCE: Projection +onto a line. + +PROFESSOR: Yeah. + +This little cube here is simply +going to get projected + +onto some line here. + +Like for example that. + +In other words it means that +this matrix is not invertible + +for one thing, but it also means +everything here gets + +mapped onto some lower +dimensional + +sub-space here in general. + +OK. + +Now remember that for a minute, +and we'll come back to + +that when we start talking about +probability densities. + +OK because of the picture we +were just looking at, the + +density of the random variables +Z at A times N, + +namely the density of Z at this +particular value here is + +just the density that we get +corresponding to the density + +of some point here mapped +over into here. + +And what's going to happen when +we take a point here and + +map it over into here? + +If you have a certain amount +of density here, which is + +probability per unit volume. + +Now when you map it into here, +and the determinant is bigger + +than zero, what you're doing +is mapping a little volume + +into a big volume. + +And if you're doing that over +small enough region where the + +probability density is of such +essentially fixed, what's + +going to happen to the +probability density over here? + +It's going to get scaled down, +and it's going to get scaled + +down precisely by that +determinant. + +OK. + +So what this is saying is the +probability density of the + +random variable z, which is +linear combination of these + +normal random variables, is in +fact the probability density + +of this normal vector N, and we +know what that probability + +density is, divided by this +determinant of a. + +In fact this is a general +formula for any old + +probability density at all. + +You can start out with anything +which you call a + +random vector N and you can +derive the probability density + +of any linear combination +of those elements in + +precisely this way. + +So long as this volume element +is non-zero, which means + +you're not mapping an entire +space into a sub-space. + +When you're mapping an entire +space into a sub-space and you + +define density as being density +per unit volume, of + +course the density in this map +space doesn't exist anymore. + +Which is exactly what +this formula says. + +If this determinant is zero, it +means this density here is + +going to be infinite in the +regions where this z exists at + +all, which is just in this +linear sub-space, and what do + +you do about that? + +I mean do you get all +frustrated about it? + +Or do you say what's going +on and treat it in + +some sensible way? + +I mean the thing is +happening here. + +And this talks about +it a little bit. + +If a is singular, then +A is going to map Rk + +into a proper sub-space. + +Determinant A is going +to be equal to 0. + +The density doesn't exist. + +So what do you do about it? + +I mean what does this mean +if you're mapping + +into a smaller sub-space. + +What does it mean in terms +of this diagram here? + +Well in the diagram here +it's pretty clear. + +Because these little cubes here +are getting mapped into + +straight lines here. + +Yeah? + +What? + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: Some linear +combinations of this are being + +mapped into 0. + +Namely if this straight line +is this way any Z which is + +going in this direction is +being mapped into 0. + +Any vector Z which is going in +this direction has to be + +identically equaled to 0. + +In other words some linear +combination of n1 and n2 is a + +random variable which takes on +the value 0 identically. + +Why do you try to represent that +in a probabilistic sense? + +Why don't you just take it out +of consideration altogether? + +Here what it means is that z1 +and z2 are simply linear + +combinations of each other. + +OK. + +In other words once you know +what the sample value of z1 + +is, you can find the +sample values z2. + +In other words z2 is a linear +combination of z1. + +It's linearly dependent on z1, +which means that you can + +identify it exactly once +you know what z1 is. + +Which means you might as +well not call it a + +random variable at all. + +Which means you might as well +view this situation where the + +determinant is 0 as where the +vector Z is really just one + +random variable, and everything +else is determined. + +So you throw out these extra +random variables, + +pseudo-random variables, which +are really just linear + +combinations of the others. + +So you deal with a smaller +dimensional set. + +You find the probability +density of the smaller + +dimensional set, and you don't +worry about all of these + +mathematical peculiarities that +would arise otherwise. + +OK. + +So once we do that, A is going +to be non-singular. + +Because we're going to be left +with a set of random + +variables, which are +not linearly + +dependent on each other. + +They can be statistically +dependent on each other, but + +not linearly dependent, OK. + +So for all z then, since +determinant A is not 0, the + +probability density at some +arbitrary vector Z is going to + +be the normal joint density +evaluated at a to the minus 1z + +divided by the determinant +of A. OK. + +In other words we're just +working the map backwards. + +This formula is the same as this +formula, except instead + +of writing An here, we're +writing z here. + +And when An is equal to z then +little n has to be equal to A + +to the minus 1z. + +And what does that say? + +It says that the joint +probability density has to be + +equal to this quantity here. + +Which in matrix terms looks +rather simple, it + +looks rather nice. + +You can rewrite this. + +This is a norm here, +so it's this vector + +there times this vector. + +Where in fact when you want to +multiply vectors in this way, + +you're taking inner product of +the vector with this cell. + +These are real vectors +we're looking at. + +Because we're trying to model +real noise, because we're + +modeling the noise on +communication channels. + +So this is going to be the +inner product of A to the + +minus 1z with itself, which +means you want to look at the + +transform of a to +the minus 1z. + +Now what's the transform +of a to the minus 1z? + +It's z transform times a to +the minus 1 transform. + +So we wind up with a to the +minus 1 transform times a to + +the minus 1 times z. + +So we have some kind of peculiar +bilinear form here. + +So for any sample value of the +random vector Z we can find + +the probability density in terms +of this quantity here. + +Which looks a little bit +peculiar, but it + +doesn't look too bad. + +OK. + +Now we want to simplify +that a little bit. + +Anytime you're dealing with +zero-mean random variables -- + +now remember I'm going to forget +to say zero-mean half + +the time because everything is +concerned with zero-mean + +random variables. + +The covariance of Z1 and Z2 is +expected value of Z1 times Z2. + +So if you have a k-tuple Z, +the covariance is a matrix + +whose i,j element is expected +value of Zi times Zj. + +And what that means is that the +covariance matrix, this is + +a matrix now, it's going to be +the expected value of z times + +z transpose. + +Z is a random vector, which is +a column random vector, Z + +transpose is a row-random +vector, which is this simply + +turned upside down, turned +by 90 degrees. + +Now when you multiply the +components of this vector + +together, you can see that what +you get is the elements + +of this covariance matrix. + +In other words this is just +standard matrix manipulation, + +which I hope most of you or at +least partly familiar with. + +OK. + +When we then talk about the +expected values Z times Z + +transpose we can write this as +the expected value of A times + +N, which is what z is. + +N transpose times A transpose, +which is what Z transpose is. + +And miraculously here the N and +the N transpose are in the + +middle here, where it's easy +to deal with them, because + +these are normal Gaussian +random variables. + +And when you look at this column +times this row, since + +all diagonal elements are +independent of each other, and + +all of them have variance one, +the expected value of N times + +N transpose is simply +the identity matrix. + +All the randomness goes out of +this which it obviously has to + +because we're looking at a +covariance which is just a + +matrix and not something +random. + +So you wind up with this +covariance matrix is equal to + +a rather arbitrary matrix A, +but not singular, times the + +transpose of that matrix. + +OK. + +We've assumed that A is +non-singular and therefore + +it's not too hard to see the k +sub Z is non-singular also. + +And explicitly case of Z mainly +its co-variance matrix, + +the inverse of it, is A to the +minus 1 transpose times A to + +the minus 1. + +Namely you take the inverse and +you start flipping things + +and you do all of these +neat matrix things + +that you always do. + +And you should review them +if you've forgotten that. + +So that when we write our +probability density, which was + +this in terms of this +transformation here, what we + +get is the density of Z is +equal to, in place of + +determinant of A, we get the +square root of the determinant + +in the k sub Z. You probably +don't remember that, but is + +what you get. + +And it's sort of a blah. + +Here this is more interesting. + +This is minus 1/2 z transpose +times Kz to the + +minus 1 times z. + +What does this tell you? + +Look at this formula. + +Is it just a big formula or +what does it say to you? + +You got to look at these things +and see what they say. + +I mean we've gone through +a lot of work to derive + +something here. + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: Well it +is Gaussian. + +Yes. + +I mean that's the way we define +jointly Gaussian. + +But what's the funny +thing about + +this probability density? + +What does it depend on? + +What do I have to tell you in +order for you to calculate + +this probability density +for every z you + +want to plug in here? + +I have to tell you what this +covariance matrix is. + +And once I tell you what the +covariance matrix is, there is + +nothing more to be specified. + +In other words, a jointly +Gaussian random vector is + +completely specified by +its covariance matrix. + +And it's specified exactly +this way by + +its covariance matrix. + +OK. + +There's nothing more there. + +So this says anytime you're +dealing with jointly Gaussian, + +the only thing you have to +be interested in is this + +covariance here. + +Namely all you need to have +jointly Gaussian is somebody + +has to tell you what the +covariance is, and somebody + +has to tell you also that +it's jointly Gaussian. + +Jointly Gaussian plus a given +covariance specifies the + +probability density. + +OK. + +What does that tell you? + +Well let's look at an example +where we just have two random + +variables, Z1 and Z2. + +then expected value of Z1 +squared is the upper. + +Left hand element of that +covariance matrix, which we'll + +call sigma 1 squared. + +The lower, right hand side of +the matrix is K22, which we'll + +call sigma 2 squared. + +And we're going to let rho be +the normalize covariance. + +We're just defining a bunch of +things here, because this is + +the way people usually +define this. + +So rho will be the normalized +cross covariance. + +Then the determinant of the +Kz is this mess here. + +For A to be non-singular, we +have to have rho less than 1. + +If rho is equal to 1 then this +determinant is going to be + +equal to 0, and we're back in +this awful case that we don't + +want to think about. + +So then if we go through the +trouble of finding out what + +the inverse of K sub z is, we +find this 1 over 1 minus row + +square times this matrix here. + +The probability density plugging +this in is this big + +thing here. + +OK what does that tell you? + +Well the thing that it tells +me is that I never want to + +deal with this, and I +particularly don't want to + +deal with it if I'm dealing with +three or more variables. + +OK. + +In other words the interesting +thing here is the simple + +formula we had before, which +is this formula. + +OK. + +And we have computers these +days which say given nice + +formulas like this, their +standard computer routines to + +calculate things like this. + +And you never want to look at +some awful mess like this. + +OK. + +And if you put a mean into here, +which you will see in + +every textbook on random +variables and probability you + +ever look at, this thing becomes +so ugly that you were + +probably convinced before you +took this class that jointly + +Gaussian random variables were +things you wanted to avoid + +like the plague. + +And if you really have to deal +with explicit formulas like + +this, you're absolutely right. + +You do want to avoid them like +the plague, because you can't + +get any insight from what that +says, or at least I can't. + +So I say OK, we have +to deal with this. + +But yet we like to get a little +more insight about what + +this means. + +And to do this, we like to find +a little bit more about + +what these bilinear forms +are all about. + +Those of you who have taken any +course on linear algebra + +have dealt with these +bilinear forms. + +And played with them forever. + +And those of you who haven't are +probably puzzled about how + +to deal with them. + +The notes have an appendix, +which is about two pages long + +which tells you what you have to +know about these matrices. + +And I will just sort of quote +those results as we go. + +Incidentally those results +are not hard to derive. + +And not hard to find +out about. + +You can simply derive them on +your own, or you can look at + +Strang's book on linear algebra, +which is about the + +simplest way to get them. + +And that's all you need to do. + +OK. + +We've said the probability +density depends on this + +bilinear form z transpose +times Kz to the + +minus 1 time z. + +What is this? + +Is this a matrix or +a vector or what? + +How many people think +it's a matrix? + +How many people think +it's a vector? + +You think it's a vector? + +OK. + +Well in a very peculiar +sense it is. + +How many people think +it's a number? + +Good. + +OK. + +It is a number, and it's +a number because + +this is a row vector. + +This is a matrix. + +This is a column vector. + +And if you think of multiplying +a matrix times a + +column vector, you get +a column vector. + +And if you take a row vector +times a column + +vector, you got a number. + +OK. + +So this is just a number which +depends on little z. + +OK. + +Kz is called a positive +definite matrix. + +And it's called a positive +definite matrix, because this + +thing is always non-negative. + +And it always has to be +non-negative because this + +refers to the -- + +if I put capital Z in here, +namely if I put the random + +vector in here Z, then what this +is, is the variance of a + +particular random variable. + +So it has to be greater +than or equal to zero. + +So anyway K sub z is always +non-negative definite. + +Here it's going to be positive +definite, because we've + +already assumed that the matrix +A was non-singular, and + +therefore the matrix Kz has +to be non-singular. + +So this has to be positive +definite. + +So it has an inverse, K sub +z minus 1 is also positive + +definite which means this +quantity is always greater + +than zero, if z is non-zero. + +You can take these positive +definite matrices and you can + +find eigenvectors and +eigenvalues for them. + +Do you ever actually calculate +these eigenvectors and + +eigenvalues? + +I hope not. + +It's a mess to do it. + +I mean it's just as bad as +writing that awful formula we + +had before. + +So you don't want to actually do +this, but it's nice to know + +that these things exist. + +And because these vectors exist, +and in fact if you have + +a matrix which is k by k, little +k by little k, then + +there are k such eigenvectors +and they can be chosen + +orthonormal. + +OK. + +In other words each of these Q +sub i are orthogonal to each + +of the others. + +You can clearly scale them, +because you scale this and + +scale this together. + +And it's going to maintain +equality. + +So you just scale them down so +you can make them normalize. + +If you have a bunch of +eigenvectors with the same + +eigenvalue, then the whole +linear sub-space formed by + +that set of eigenvectors all +have the same eigenvalue + +lambda sub i. + +Namely you take any linear +combination of these things + +which satisfy this equation +for a particular lambda. + +And any linear combination +will satisfy the + +same the same equation. + +So you can simply choose an +orthonormal set among them to + +satisfy this. + +And if you look at Q sub i and +Q sub j, which have different + +eigenvalues, then it's pretty +easy to show that in fact they + +have to be orthogonal +to each other. + +So anyway when you do this you +wind up with this form becomes + +just the sum over i of lambda +sub i to the minus 1. + +Namely these eigenvalues +to the minus 1. + +These eigenvalues are +all positive. + +Times the inner product +of z with Q sub i. + +In other words, you take +whatever vector Z you're + +interested in here, you +project it on these k + +orthonormal vectors Q sub i. + +You get those k values. + +And then this form here is +just that sum there. + +So when you write +the probability + +density in that way -- + +we still have this here +we'll get rid of that + +in the minute -- + +you have e to the minus sum over +i, these inner product + +terms squared divided by +2 times lambda sub i. + +That's just because this +is equal to this. + +It's just substituting this for +this in the formula for + +the probability density. + +OK. + +What does that say +pictorially? + +Let me show you a picture +of it first. + +It says that for any positive +definite matrix and therefore + +for any covariance matrix, +you can always find these + +orthonormal vectors. + +I've drawn them here +for two dimensions. + +They're just some arbitrary +vector q1; q2 has to be + +orthogonal to it. + +And if you look at the square +root of lambda 1 times q1, you + +got a point here. + +You look at the square root of +lambda 2 times q2, you got a + +point here. + +If you then look at this +probability density here, you + +see that all the points on this +ellipse here have to have + +the same sum of z +times Q sub i. + +OK. + +It looked a little +better over here. + +Yes. + +OK. + +Namely the points little z for +which this is constant are the + +points which form +this ellipse. + +And it's the ellipse which has +the axes square root of lambda + +i times Q sub i. + +And then you just imagine it +if it's lined up this way. + +And think of what you would get +if you were looking at the + +lines of equal probability +density for independent + +Gaussian random variables with +different variances. + +I mean we already pointed out +if the variances are all the + +same, these equal probability +contours are spheres. + +If you now expand on some of +the axes, you get ellipses. + +And now we've taken these +arbitrary vectors, so these + +are not in the directions we +started out with, but in some + +arbitrary directions. + +We have q1 and q2 are +orthornormal to each other, + +because that's the way +we've chosen them. + +And then the probability +density has this form + +which is this form. + +And the other thing we can do is +to take this form here and + +say gee this is just a +probability density for a + +bunch of independent random +variables, where the + +independent random variables are +the inner product of the + +random vector Z with Q sub 1 up +to the inner product of z + +with Q sub k. + +So these are independent +Gaussian random variables. + +They have variances +lambda sub i. + +And this is the nicest formula +for the probability density of + +an arbitrary set of jointly +density of jointly Gaussian + +random variables. + +OK. + +In other words what this says +is in general if you have a + +set of jointly Gaussian random +variables and I have this + +messy form here, all you're +doing is looking at them in a + +wrong coordinate system. + +If you switch them around, you +look at them this way instead + +of this way, you're going to +have independent Gaussian + +random variables. + +And the way to look at them +is found by solving this + +eigenvector eigenvalue equation, +which will tell you + +what these orthogonal +directions are. + +And then it'll tell you how to +get this nice picture that + +looks this way. + +OK. + +OK so that tells us what we +need to know, maybe even a + +little more than we have to +know, about jointly Gaussian + +random variables. + +But there's one more +bonus we get. + +And the bonus is +the following. + +If you create a matrix here B +where the i'th row of B is + +this vector Q sub i divided by +the square root of lambda sub + +i, then what this is going to +do is the corresponding + +element here is going to be a +normalized Gaussian random + +variable with variance one and +all of these are going to be + +independent of each other. + +OK. + +That's essentially what +we were saying before. + +This is just another way of +saying the same thing. + +That when you squish this +probability density around and + +look at it in a different frame +of reference, and then + +you scale the random variables +down or up, what you wind up + +with is IID normal Gaussian +random variables. + +OK. + +But that says that Z is +equal to B to the + +minus 1 times N prime. + +Well so what? + +Here's the reason for so what. + +We started out with a definition +of jointly + +Gaussian, which is probably not +the definition of jointly + +Gaussian you've ever seen if +you've seen this before. + +Then what we did was to say, +OK if you have jointly + +Gaussian random variables +and they're not linearly + +independent and none of them are +linearly dependent on the + +others, then this matrix +A is invertible. + +From that we derive the +probability density. + +From the probability density +we derive this. + +OK. + +The only thing you need +to get this is + +the probability density. + +And this says that anytime you +have a random vector Z with + +this probability density that +we just wrote down. + +Then you have the property that +N prime is equal to BZ, + +and Z is equal to B to +the minus 1 N prime. + +Which says that if you have this +probability density, then + +you have jointly Gaussian +random variables. + +So we have an alternate + +definition of jointly Gaussian. + +Random variables are jointly +Gaussian if they have this + +probability density. + +You can somehow represent them +as linear combinations of + +normal random variables. + +OK. + +Then there's something +even simpler. + +It says that if all linear +combinations of a random + +vector Z are Gaussian, then +Z is jointly Gaussian. + +Why is that? + +well If you look at this formula +here, it says take any + +old random vector at all that +has a covariance matrix. + +From that covariance matrix, we +can solve for all of these + +eigenvectors. + +If I find the appropriate random +variables here from + +this transformation, those +random variables are then + +uncorrelated from each other, +they are all statistically + +independent of each other, And +it follows from that, that if + +all these linear combinations +are Gaussian then Z has to be + +jointly Gaussian. + +OK. + +So we now have three +definitions. + +This one is the simplest +one to state. + +It's the hardest one +to work with. + +That's life you know. + +This one is probably the most +straightforward, because you + +don't have to know anything to +understand this definition. + +This original definition is +physically the most appealing + +because it shows why noise +vectors actually + +do have this property. + +OK. + +So here's a summary +of all of this. + +It says if Kz is singular, you +want to remove the linearly + +independent random variables. + +You just take them away because +they're uniquely + +specified in terms of +the other variables. + +And then you take the resulting +non-singular matrix, + +and Z is going to be jointly +Gaussian if and only if Z is + +equal to AN for some normal +random variable N. If Z has + +jointly Gaussian density or if +all linear combinations of Z + +are Gaussian all of this for 0 +mean would mean it applies to + +fluctuation. + +OK. + +So why do we have to know all of +that about jointly Gaussian + +random variables? + +Well because everything about +Gaussian processes depends on + +jointly Gaussian random +variables. + +You can't do anything with +Gaussian processes without + +being able to look +at these jointly + +Gaussian random variables. + +And the reason is that we said +that Z of t is a Gaussian + +process if for every k and every +set of time instance, + +every set of e, that's +t1 to t sub k. + +If Z of t1 up to Z of +tk is a jointly + +Gaussian random vector. + +OK. + +So that directly links the +definition of a Gaussian + +process to Gaussian +random vectors. + +OK. + +Supposed the sample functions +of Z of t or L2 with + +probability one. + +I want to say a little bit about +this because otherwise + +you can't sort out any of these +things about how L2 + +theory connects with +random processes. + +OK. + +So I'm going to start out by +just assuming that all these + +sample functions are going +to be L2 functions with + +probability 1. + +One way to ensure this is to +look only at processes of the + +form Z of t equals some sum +of Z sub i times ti of t. + +OK remember at the beginning +we started looking at this + +process the sum of a set of +normalized Gaussian random + +variables times sinc +functions times + +displaced sinc functions. + +You can also do the same +thing with Fourier + +coefficients or anything. + +You got a fairly general set +of processes that way. + +unfortunately they don't quite +work, because if you look at + +the sinc functions and you +look at noise, which is + +independent and identically +distributed in time, then the + +sample functions are going +to have infinite energy. + +I mean that kind of process +just runs on forever. + +It runs on with finite +power forever. + +And therefore it has +infinite energy. + +And therefore the simplest +process to look at, the sample + +functions are non-L2 with +probability one, which is sort + +of unfortunate. + +So we say OK we don't care about +that, because if you + +want to look at that process +a sum of Z sub i times sinc + +functions, what do +you care about? + +I mean you only care about the +terms in that expansion, which + +run from the big bang until +the next big bang. + +OK. + +We certainly don't care about it +before that or after that. + +And if we look within those +finite time limits, then all + +these functions are +going to be L2. + +Because they just last for +a finite amount of time. + +So all we need to do is to +truncate these things somehow. + +And we're going to diddle around +a little bit with a + +question of how to truncate +these series. + +But for the time being we +just say we can do that. + +And we will do it. + +So we can look at any processes +the form sum of Zi + +times phi i of t, where the Zi +are independent and the phi i + +of t are orthonormal. + +And to make things L2, we're +going to assume that the sum + +over i of Zi squared bar +is less than infinity. + +OK. + +In other words we only take a +finite number of these things, + +or if we want to take infinite +a number of them, the + +variances are going +to go off to zero. + +And I don't know whether you're +proving it in the + +homework this time or you will +prove it in the homework next + +time, I forget, but you're going +to look at the question + +of why this finite variance +condition makes these sample + +functions be L2 with +probability one. + +OK. + +So if you had this condition, +then all your sample functions + +are going to be L2. + +I'm going to get off +all of this L2 + +business relatively shortly. + +I want to do a little bit +of it to start with. + +Because if any of you have start +doing any research in + +this area, at some point you're +going to be merrily + +working away calculating +all sorts of things. + +And suddenly you're going to +find that none of it exists, + +because of these problems +of infinite energy. + +And you're going to +get very puzzled. + +So one of the things I tried to +do in the notes is to write + +them in way that you can +understand them at a first + +reading without worrying +about any of this. + +And then when you go back for a +second reading, you can pick + +up all the mathematics +that you need. + +So that in fact you won't have +the problem of suddenly + +finding out that three-quarters +of your thesis + +has to be thrown away, because +you've been dealing with + +things that don't +make any sense. + +OK. + +So, we're going to define linear +functionals in the + +following way. + +We're going to first look at the +sample functions of this + +random process Z. OK. + +Now we talked about +this last time. + +If you have a random process Z +than really what you have is a + +set of functions defined +on some samples space. + +So the quantities you're +interested in is what is the + +value of the random process at +time t for sample point omega. + +OK. + +If we look at that and make it +for a given omega, this thing + +becomes a function of t. + +In fact for a given omega, this +is just what we've been + +calling a sample element +of the random process. + +So if we take this sample +element, look at the inner + +product of that with some +function g of t. + +In other words we look at the +integral of Z of t omega times + +g of t, dt. + +And if all these sample +functions are L2 and if g of t + +is L2, what happens when you +take the integral of an L2 + +function times an L2 function, +which is the inner product of + +something L2 with something L2 +which says something with + +finite energy inner +product with + +something with finite energy. + +Well the Schwarz inequality +tells you that if this has + +finite energy and this has +finite energy, the inner + +product exists. + +That's the reason why we went +through the Schwarz + +inequality. + +It's the main reason +for doing that. + +So these things have +finite value. + +So V of omega the results of +doing this namely V as a + +function of the sample space +is a real number. + +And it's a real number for the +sample points of omega with + +probability one, which means +we can talk about V as a + +random variable. + +OK. + +And now V is a random variable +which is defined in this way. + +And from now on we will call +these things linear + +functionals which are in fact +the integral of a random + +process times a function. + +And we can take that +kind of integral. + +It sort of looks like the linear +combinations of things + +we were doing before when we +were talking about matrices + +and random vectors. + +OK. + +If we restrict the random +process to have the following + +form, where these are +independent and these are + +orthonormal, then one of these +linear functionals is given by + +the random variable V is going +to be the integral of Z of t + +times g of t, but +Z of t is this. + +And at this point we're not +going to fuss about + +interchanging integrals +with summations. + +You have the machinery to do it, +because we're now dealing + +with an L2 space. + +We're not going to +fuss about it. + +And I advise you not +to fuss about it. + +So we have a sum of these random +variables here times + +these integrals here. + +These integrals here are just +projections of g of t on this + +space of orthonormal +functions. + +So whatever space of orthonormal +functions gives + +you your jollies, use it talk +about the inner products on + +that space. + +This gives you a nice inner +products space of + +sequences of numbers. + +And then if the z i are jointly +Gaussian, then V is + +going to be Gaussian. + +And then to generalize this one +little bit further, if you + +take a whole bunch of L2 +functions, g1 of t g2 of t and + +so forth, you can talk about +a whole bunch of random + +variables V1 up to V sub j, 0. + +And V sub j is going to be +the integral of Z of + +t times gj of tdt. + +Remember this thing +looks very simple. + +It looks like the -- + +like the convolutions you've +been doing all your life. + +It's not. + +It's really a rather +peculiar quantity. + +This in fact is what we call a +linear functional, and is the + +integral of a random +process times this. + +Which we have defined in terms +of the sample functions of the + +random process. + +And now we said OK now that we +understand what it is, we will + +just write this all the time. + +But I just caution +you not to let + +familiarity breed contempt. + +Because this is a rather +peculiar notion. + +And a rather powerful notion. + +OK. + +So these things are +jointly Gaussian. + +We want to take the expected +value of V sub i times V sub + +j, and now we're going to do +this without worrying about + +being careful at all. + +We have the expected value of +the integral of Z of t, gi of + +t, td times the integral of +Z tau gj of tau, d tau. + +And now we're going to slide +this expected value inside of + +both of these integrals. + +And not worry about it. + +And therefore what we're going +to have is a double integral + +of gi of t expected value of z +of t time z of tau times gj of + +tau dt, d tau, which +is this thing here. + +Which you should compare with +what we've been dealing with + +most of the lecture today. + +This is the same kind of form +for a covariance function as + +we've been dealing with for +covariance matrices. + +It has very similar effects. + +I mean before you were just +talking about finite + +dimensional matrices, which is +all simple mathematically in + +eigenfunctions and +eigenvalues. + +You have eigenfunctions +and eigenvalues of + +these things also. + +And so long as these are defined +nicely by these L2 + +properties we've been +talking about. + +In fact you can deal with these +in virtually the same + +way that you can deal with +the matrices we were + +dealing with before. + +If you just remember what the +results are from matrices, you + +can guess what they are for +these covariance functions. + +OK. + +But anyway you can find the +expected value of Vi times Vj + +by this formula. + +Again we're dealing with +zero-mean and therefore we + +don't have to worry about the +mean, put that in later. + +And that all exists. + +OK. + +So the next thing we want +to deal with, hitting + +you with a lot today. + +But I mean the trouble is a lot +of this is half familiar + +to most of you. + +People who have taken various +communication courses at + +various places have all been +exposed to random processes in + +some highly trivialized sense. + +But the major results are the +same as the results we're + +going through here. + +And all we're doing here is +adding a little bit of + +carefulness about what works +and what doesn't work. + +Incidentally in the notes which +is towards the end of + +lectures 14 and 15, we give +three examples which let you + +know why in fact we want to +look primarily at random + +processes which are defined in +terms of a sum of independent + +Gaussian random variables time +orthonormal functions. + +And if you look at those +three examples, some + +of them have problems. + +Because of the fact that +everything you're dealing with + +has infinite energy. + +And therefore it doesn't +really make any sense. + +And one of them I should +talk about this just a + +little bit in class. + +And I think I still have a +couple of minutes, is a very + +strange process where +Z of t is IID. + +In fact just let it be normal. + +And independent for all t. + +OK. + +In other words you generate a +random process by looking at + +an uncountably infinite +collection of + +normal random variables. + +How do you deal with +such a process? + +I don't know how to +deal with it. + +I mean it sounds like +it's simple. + +If I put this on a quiz, +three-quarters of you would + +say oh that's very simple. + +What we're dealing with is a +family of impulse functions. + +Spaced arbitrarily +closely together. + +This is not impulse function. + +Impulse functions are even worse +than this, but this is + +bad enough. + +When we start talking about +spectral density, we can + +explain this a little bit better +by thinking this kind + +of process it doesn't +make any sense. + +But this kind of process, if +you look at its spectral + +density, it's going to have a +spectral density which is zero + +everywhere, but whose integral +over all frequencies is one. + +OK. + +In other words it's not +something you want to wish on + +your on your worse friend. + +It makes a certain amount of +sense as a limit of things. + +You can look at a very broadband +process where in + +fact you spread the process +out enormously. + +You can make pseudo noise which +looks sort of like this. + +And you make the process broader +and broader and lower + +and lower intensity +everywhere. + +But it still has this +energy of one. + +It still has a power +of one everywhere. + +And it just is ugly. + +OK. + +Now if you never worried about +these questions of L2, you + +would look at a process like +that and say, gee there must + +be some easy way to handle that +because it's probably the + +easiest process you +can define. + +I mean everything is normal. + +If you look at any set at +different times, you get a set + +of IID normal Gaussian +variables. + +You try to put it together, and +it doesn't mean anything. + +If you pass it through a filter, +the filter is going to + +cancel it all out. + +So anyway, that's one reason +why we want to look at this + +restricted class of random +processes we're looking at. + +OK. + +What we're interested in now is +we want to take a Gaussian + +random process really, but you +can take any random process. + +We want to pass it through a +filter, and we want to look at + +the random process +that comes out. + +OK. + +And that certainly is a very +physical kind of operation. + +I mean any kind of communication +system that you + +build is going to have +noise on the channel. + +And one of the first things +you're going to do is you're + +going to filter what +you've received. + +So you have to have some way +of dealing with this. + +OK. + +And the way we sort of been +dealing with it all along in + +terms of the transmitted way +forms we've been dealing with + +is to say OK. + +What we're going to do is to +first look what happens when + +we take sample functions of +this, pass them through the + +filter, and then what comes +out is going to be some + +function again. + +And then we're back into +what you studied as an + +undergraduate talking about +functions through filters. + +We're going to jazz it up a +little bit by saying these + +functions are going to +be L2 the filters + +are going to be L2. + +So that in fact you know +you'd get something + +out that make sense. + +So what we're doing is looking +at these sample functions V + +the output at time tau for +sample point omega is going to + +be the convolution of the input +at time t and sample + +point omega. + +Remember this one sample point +exists for all time. + +That's why these sample points +and sample spaces are so damn + +complicated. + +Because they have everything +in them. + +OK. + +So there's one sample point +which exists for all of them. + +This is a sample function. + +You're passing the sample +function through a filter, + +which is just normal +convolution. + +What comes out then. + +If in fact we express this +random process in terms of + +this orthonormal sum the way +we've been doing before. + +Is you get the sum over j of +this, which is a sample value + +of the j'th random variable +coming out times the integral + +of pj of t, h of tau +minus t, d tau. + +OK. + +For each tau that you look at, +this is just a sample value of + +a linear functional. + +OK. + +If I want to look at this at one +value of tau, I have this + +integral here which is +a random process. + +A sample value of a +random process at + +omega time a function. + +This is just a function +of t for given tau. + +OK. + +So this is a linear +functional. + +As a type we've been +talking about. + +And that linear functional +is then given by + +this for each tau. + +This is a sample value +of a linear + +functional we can talk about. + +OK. + +These things are then, if you +look over the whole sample + +space omega, V of tau becomes +a random variable. + +OK. + +V of tau is the random variable +whose sample values + +are V of t omega, and they're +given by this. + +So if z of t is Gaussian +process, you get jointly + +Gaussian linear functionals at +each of any set of times tau + +1, tau 2 up to tau sub k. + +So this just gives you a whole +set of linear functionals. + +And if z of t is a Gaussian +process, then all these linear + +functionals are going to be +jointly Gaussian also. + +And bingo. + +What we have then is an +alternate way to generate + +Gaussian processes. + +OK. + +In other words you can generate +a Gaussian process by + +specifying at each set of k +times, you have jointly + +Gaussian random variables. + +But once you do that, once you +understand one Gaussian + +process, you're off +and running. + +Because then you can pass +it through any L2 filter + +that you want to. + +And you generate another +Gaussian process. + +So for example, if you start +out with this sinc type + +process, I mean we'll see that +that has a spectral density, + +which is flat over +all frequencies. + +And we'll talk about spectral +density tomorrow. + +But then you pass it through a +linear filter, and you can + +give it any spectral density +that you want. + +So at this point, we really +have enough to talk about + +arbitrary covariance functions +just by starting out with + +random processes, which are +defined in terms of some + +sequence of orthonormal +random variables. + +OK. + +Now we can get to covariance +function of a filter process + +in the same way as we got the +matrix for linear functionals. + +OK. + +And this is just computation. + +OK. + +So what is it? + +The covariance function of +this output process V + +evaluated at one time +r another time s. + +One of the nasty things about +notation when you start + +dealing with a covariance +function of the input and the + +output to a linear filter is +you suddenly need to worry + +about two times at the +input and two other + +times at the output. + +OK. + +Because this thing is then +expected value of V sub r + +times the expected +value of V subs. + +OK. + +This is a random variable, which +is the process V of r + +evaluated at time r. + +This is the random variable, +which is the process V of t + +evaluated at a particular +time s. + +This is going to be the expected +value of what this + +random variable now is the +integral of the random process + +z of t times this function +here, which is now + +a function of t. + +Because we're looking at +a fixed value of r. + +So this is a linear functional, + +which is a random variable. + +This is another linear +functional. + +This is evaluated at some time +s, which is the output of the + +filter at time s. + +Then we will throw caution to +the wind interchange integrals + +with expectation +and everything. + +And then in the middle we'll +have expected value of z of t + +times z of tau, which is the +covariance function of z. + +OK. + +So the covariance function of +z then specifies what the + +covariance function +of the output is. + +OK. + +So whenever you pass a random +process through a filter if + +you know what the covariance +function of input to the + +filter is, you can find the +covariance function of the + +output of the filter. + +That's a kind of a nasty +formula, it's not very nice. + +But anyway the thing that it +tells you is that whether this + +random process is +Gaussian or not. + +The only thing that determines +the covariance function of the + +output of the filter is the +covariance function of the + +input to the filter plus of +course the filter response, + +which is needed OK. + +And this is just the same kind +of bilinear form that we were + +dealing with before. + +Next time we will talk a little +bit about the fact that + +when you're dealing with a +bilinear form like this, you + +can take these covariance +functions and they have the + +same kind of eigenvalues and +eigenvectors that we had + +before for a matrix. + +Namely this is again going to +be positive definite as a + +function, and we will be able +to find its eigenvectors and + +its eigenvalues. + +We can't calculate them. + +Computers can calculate them. + +People who've spend their +lives doing this + +can calculate them. + +I wouldn't suggest that you +spend your life doing this. + +Because again you would be +setting yourself up as a + +second class computer, and +you don't make any + +profit out of that. + +But anyway, we can find this +in principle from this. + +OK. + +One of the things that we +haven't talked about at all + +yet, and which we will start +talking about next time in + +which the next set of lecture +notes, lecture 16, we'll deal + +with is the question +of stationarity. + +Let me say just a little bit +about that to get into it. + +And then we'll talk a lot +more about it next time. + +The notes will probably be on +the web some time tomorrow. + +I hope before noon if you +want to look at them. + +Physically if you look at a +stochastic process, and you + +want to model it. + +I mean suppose you want to +model a noise process. + +How do you model a +noise process? + +Well you look at it over +a long period of time. + +You start taking statistics +about it over a + +long period of time. + +And somehow you want to model +it in such a way, I mean the + +only thing you can look at +is statistics over a + +long period of time. + +So if you're only looking at one +process, you can look at + +it for a year and then you can +model it, and then you can use + +that model for the +next 10 years. + +And what that's assuming is that +the noise process looks + +the same way this year +as it does next year. + +You can go further than that +and say, OK I'm going to + +manufacture cell phones or some +other kind of widget. + +And what I'm interested in then +is what these noise wave + +forms are to the whole +collection of my widgets. + +Namely different people +will buy my widgets. + +They will use them in +different places. + +So I'm interested in modeling +the noise over this whole set + +of widgets. + +But still if you're doing that +you're still almost forced to + +deal with models which have the +same statistics over at + +least a broad range of times. + +Sometimes when we're dealing +with wireless communication we + +say, no the channel keeps +changing in time. and the + +channel keeps changing +slowly in time. + +And therefore you don't have +the same statistics + +now as you have then. + +If you want to understands that, +believe me, the only way + +you're going to understand it is +to first understand how to + +deal with statistics for +the channel which + +stay the same forever. + +And once you understand those +statistics, you will then be + +in a position to start to +understand what happens when + +these statistics +change slowly. + +OK. + +In other words, what our +modeling assumption is in this + +course, and I believe it's the +right modeling assumption for + +all engineers, is that you never +start with some physical + +phenomena and say, I want to +test the hell out of this + +until I find an appropriate +statistical model for it. + +You do that only after +you know enough + +about random processes. + +That you know how to deal with +an enormous variety of + +different home cooked +random processes. + +OK. + +So what we do in a course like +this is we deal with lots of + +different home cooked random +processes, which is in fact + +why we've done rather peculiar +things like saying, let's look + +at a random process which +comes from a sum of + +independent random variables +multiplied + +by orthonormal functions. + +And you see what we've +accomplished by that already. + +Namely by starting out that way +we've been able to define + +Gaussian processes. + +We've been able to define what +happens when one of those + +Gaussian processes goes +through a filter. + +And in fact, that gives a way +of generating a lot more + +random processes. + +And next time what we're going +to do is not to say how is it + +that we know that processes +are stationary. + +How do you test whether +processes are + +stationary or not. + +But we're just going to assume +that they're stationary. + +In other words if they had the +same statistics now as they're + +going to have next year. + +And those statistics stay +the same forever. + +And then see what we +can say about it. + +To give you a clue as to how +to start looking at this, + +remember what we said quite +a long time ago + +about Markov chains. + +OK. + +And now when you look at Markov +chains, remember that + +what happens at one time is +statistically a function of + +what happened at the unit +of time before it. + +OK. + +But we can still model those +Markov change as being + +stationary. + +Because the dependents at this +time on the previous sample of + +time is the same now as it will +be five years from now. + +OK. + +In other words you can't just +look at the process at one + +instant of time and say +this is independent + +of all other times. + +That's not what stationary +means. + +What stationary means is the way +the process depends on the + +past at time t is the same is +the way it depends on the past + +at some later time tau. + +And that in fact is the way +we're going to define + +stationarity. + +It's at these joint sample times +that we're going to be + +looking at. + +Which I had a better +word for that. + +Join sets of epochs that +we'll be looking at. + +The joint statistics over a set +of epics is going to be + +the same now as it will be at +sometime in the future. + +And that's the way we're going +to define stationarity. + +A prelude of what we're going +to find when we do that is + +that this covariance function, +if the covariance function at + +time t and time tau is the same +if you translate it up to + +t plus t1 and tau plus t1, then +in fact this function is + +going to be a function only if +the difference t minus tau. + +It's going to be a function +of one variable + +instead of two variables. + +OK. + +So as soon as we get this +function being a function of + +one variable instead of two +variables, first thing we're + +going to do is to take the +Fourier transform of this. + +Because then we'll be taking +the Fourier transform of a + +function of a single variable. + +We're going to call +that the spectral + +density of the process. + +And we're going to find that for +stationary processes the + +spectrum densities tell you + +everything if they're Gaussian. + +Why is that? + +Well the inverse Fourier +transform is + +this covariance function. + +And we've now seen that the +covariance function tells you + +everything about a +Gaussian process. + +So if you know the spectral +density for a stationary + +process, it will tell +you everything. + +We will also have to fiddle +around a little bit about how + +we define stationarity. + +But at the same time +don't have this + +infinite energy problem. + +And the way we're going +to do it is the way + +we've done it all along. + +We're going to take something +that looked stationary, we're + +going to truncate it over some +long period of time, and we're + +going to have our cake and +eat it too that way. + +OK. + +So we'll do that next time. \ No newline at end of file diff --git a/zM5MW5NKZJg.txt b/zM5MW5NKZJg.txt new file mode 100644 index 0000000000000000000000000000000000000000..eb094b23e955a8410410946a21b9ade8039e91b4 --- /dev/null +++ b/zM5MW5NKZJg.txt @@ -0,0 +1,5955 @@ +align:start position:0% + +The following content is provided under + + align:start position:0% +The following content is provided under + + + align:start position:0% +The following content is provided under +a Creative Common License. Your support + + align:start position:0% +a Creative Common License. Your support + + + align:start position:0% +a Creative Common License. Your support +will help MIT Open Courseware continue + + align:start position:0% +will help MIT Open Courseware continue + + + align:start position:0% +will help MIT Open Courseware continue +to offer high-quality educational + + align:start position:0% +to offer high-quality educational + + + align:start position:0% +to offer high-quality educational +resources for free. To make a donation + + align:start position:0% +resources for free. To make a donation + + + align:start position:0% +resources for free. To make a donation +or view additional materials from + + align:start position:0% +or view additional materials from + + + align:start position:0% +or view additional materials from +hundreds of MIT courses, visit MIT Open + + align:start position:0% +hundreds of MIT courses, visit MIT Open + + + align:start position:0% +hundreds of MIT courses, visit MIT Open +Courseware at ocw.mmit.edu. + + align:start position:0% + + + + align:start position:0% + +So today + + align:start position:0% +So today + + + align:start position:0% +So today +we're going to look at approximation + + align:start position:0% +we're going to look at approximation + + + align:start position:0% +we're going to look at approximation +algorithms for the traveling salesman + + align:start position:0% +algorithms for the traveling salesman + + + align:start position:0% +algorithms for the traveling salesman +problem. So you should so I hope + + align:start position:0% +problem. So you should so I hope + + + align:start position:0% +problem. So you should so I hope +everyone knows what the trouble and + + align:start position:0% +everyone knows what the trouble and + + + align:start position:0% +everyone knows what the trouble and +salesman problem is. You have a graph + + align:start position:0% +salesman problem is. You have a graph + + + align:start position:0% +salesman problem is. You have a graph +you're trying to visit every vertex and + + align:start position:0% +you're trying to visit every vertex and + + + align:start position:0% +you're trying to visit every vertex and +you want to do this. So you start at a + + align:start position:0% +you want to do this. So you start at a + + + align:start position:0% +you want to do this. So you start at a +vertex you visit every single one and + + align:start position:0% +vertex you visit every single one and + + + align:start position:0% +vertex you visit every single one and +you end at the starting vertex and you + + align:start position:0% +you end at the starting vertex and you + + + align:start position:0% +you end at the starting vertex and you +want to do that in the shortest possible + + align:start position:0% +want to do that in the shortest possible + + + align:start position:0% +want to do that in the shortest possible +time or distance or whatever the metric + + align:start position:0% +time or distance or whatever the metric + + + align:start position:0% +time or distance or whatever the metric +is. So unfortunately this is np hard + + align:start position:0% +is. So unfortunately this is np hard + + + align:start position:0% +is. So unfortunately this is np hard +also the approximation algorithms for + + align:start position:0% +also the approximation algorithms for + + + align:start position:0% +also the approximation algorithms for +any constant approximation is also known + + align:start position:0% +any constant approximation is also known + + + align:start position:0% +any constant approximation is also known +to be np hard. Um so you should have + + align:start position:0% +to be np hard. Um so you should have + + + align:start position:0% +to be np hard. Um so you should have +gone over approximation algorithms in + + align:start position:0% +gone over approximation algorithms in + + + align:start position:0% +gone over approximation algorithms in +lecture. So basically uh let's say the + + align:start position:0% +lecture. So basically uh let's say the + + + align:start position:0% +lecture. So basically uh let's say the +optimal solution has some value v and if + + align:start position:0% +optimal solution has some value v and if + + + align:start position:0% +optimal solution has some value v and if +you want to calc if you want to + + align:start position:0% +you want to calc if you want to + + + align:start position:0% +you want to calc if you want to +guarantee that your algorithm will end + + align:start position:0% +guarantee that your algorithm will end + + + align:start position:0% +guarantee that your algorithm will end +up with a value which is within a + + align:start position:0% +up with a value which is within a + + + align:start position:0% +up with a value which is within a +constant factor of v so less than cv + + align:start position:0% +constant factor of v so less than cv + + + align:start position:0% +constant factor of v so less than cv +that that is an approximation algorithm + + align:start position:0% +that that is an approximation algorithm + + + align:start position:0% +that that is an approximation algorithm +but for the traveling salesman problem + + align:start position:0% +but for the traveling salesman problem + + + align:start position:0% +but for the traveling salesman problem +the approx constant approximation + + align:start position:0% +the approx constant approximation + + + align:start position:0% +the approx constant approximation +algorithms are also np hard so instead + + align:start position:0% +algorithms are also np hard so instead + + + align:start position:0% +algorithms are also np hard so instead +we we modify it slightly so on the + + align:start position:0% +we we modify it slightly so on the + + + align:start position:0% +we we modify it slightly so on the +traveling salesman problem we impose + + align:start position:0% +traveling salesman problem we impose + + + align:start position:0% +traveling salesman problem we impose +something called a metric so the + + align:start position:0% +something called a metric so the + + + align:start position:0% +something called a metric so the +important relation here is this one so + + align:start position:0% +important relation here is this one so + + + align:start position:0% +important relation here is this one so +first of all Let's go through this. So + + align:start position:0% +first of all Let's go through this. So + + + align:start position:0% +first of all Let's go through this. So +you have a distance metric for so if X Y + + align:start position:0% +you have a distance metric for so if X Y + + + align:start position:0% +you have a distance metric for so if X Y +are vertices your distance is always + + align:start position:0% +are vertices your distance is always + + + align:start position:0% +are vertices your distance is always +greater than zero which is reasonable. + + align:start position:0% +greater than zero which is reasonable. + + + align:start position:0% +greater than zero which is reasonable. +Your this undirected which is this + + align:start position:0% +Your this undirected which is this + + + align:start position:0% +Your this undirected which is this +relation and you have the triangle + + align:start position:0% +relation and you have the triangle + + + align:start position:0% +relation and you have the triangle +inequality which means that if you have + + align:start position:0% +inequality which means that if you have + + + align:start position:0% +inequality which means that if you have +three vert vertices + + align:start position:0% +three vert vertices + + + align:start position:0% +three vert vertices +and you have distances like this + + align:start position:0% +and you have distances like this + + + align:start position:0% +and you have distances like this +distance is always smaller than the sum + + align:start position:0% +distance is always smaller than the sum + + + align:start position:0% +distance is always smaller than the sum +of these two distances which is at least + + align:start position:0% +of these two distances which is at least + + + align:start position:0% +of these two distances which is at least +like real worldish things that make + + align:start position:0% +like real worldish things that make + + + align:start position:0% +like real worldish things that make +sense right if if this system was longer + + align:start position:0% +sense right if if this system was longer + + + align:start position:0% +sense right if if this system was longer +you would just take this path instead. + + align:start position:0% +you would just take this path instead. + + + align:start position:0% +you would just take this path instead. +So the distance by taking another node + + align:start position:0% +So the distance by taking another node + + + align:start position:0% +So the distance by taking another node +is always greater than equal to the + + align:start position:0% +is always greater than equal to the + + + align:start position:0% +is always greater than equal to the +direct distance. + + align:start position:0% +direct distance. + + + align:start position:0% +direct distance. +So + + align:start position:0% +So + + + align:start position:0% +So +turns out the metric ts problem is also + + align:start position:0% +turns out the metric ts problem is also + + + align:start position:0% +turns out the metric ts problem is also +np hard. So not nothing very great + + align:start position:0% +np hard. So not nothing very great + + + align:start position:0% +np hard. So not nothing very great +there. But but you can do a constant + + align:start position:0% +there. But but you can do a constant + + + align:start position:0% +there. But but you can do a constant +approximation here and we'll go through + + align:start position:0% +approximation here and we'll go through + + + align:start position:0% +approximation here and we'll go through +two approximations today. The first the + + align:start position:0% +two approximations today. The first the + + + align:start position:0% +two approximations today. The first the +simpler one is a two approximation + + align:start position:0% + + + + align:start position:0% + +and then we'll improve this to 3 over2. + + align:start position:0% +and then we'll improve this to 3 over2. + + + align:start position:0% +and then we'll improve this to 3 over2. +So + + align:start position:0% +So + + + align:start position:0% +So +let's start with the first one. So + + align:start position:0% +let's start with the first one. So + + + align:start position:0% +let's start with the first one. So +before we begin, let's uh define a + + align:start position:0% +before we begin, let's uh define a + + + align:start position:0% +before we begin, let's uh define a +couple of terms. Let's define + + align:start position:0% +couple of terms. Let's define + + + align:start position:0% +couple of terms. Let's define +C of S. So let's so what is S? So let S + + align:start position:0% +C of S. So let's so what is S? So let S + + + align:start position:0% +C of S. So let's so what is S? So let S +be a path + + align:start position:0% +be a path + + + align:start position:0% +be a path +or rather let's say S + + align:start position:0% +or rather let's say S + + + align:start position:0% +or rather let's say S +is a set of edges. + + align:start position:0% + + + + align:start position:0% + +So if you have your graph here, + + align:start position:0% + + + + align:start position:0% + +your set of edges could be something + + align:start position:0% +your set of edges could be something + + + align:start position:0% +your set of edges could be something +like this, this, this, this. So that + + align:start position:0% +like this, this, this, this. So that + + + align:start position:0% +like this, this, this, this. So that +that's set of edges. And C of S is + + align:start position:0% +that's set of edges. And C of S is + + + align:start position:0% +that's set of edges. And C of S is +defined as the sum of the sum of the + + align:start position:0% +defined as the sum of the sum of the + + + align:start position:0% +defined as the sum of the sum of the +weights of all the edges. And this + + align:start position:0% +weights of all the edges. And this + + + align:start position:0% +weights of all the edges. And this +actually should be a multi set because + + align:start position:0% +actually should be a multi set because + + + align:start position:0% +actually should be a multi set because +you can have you can count the same edge + + align:start position:0% +you can have you can count the same edge + + + align:start position:0% +you can have you can count the same edge +twice. So you can count this edge three + + align:start position:0% +twice. So you can count this edge three + + + align:start position:0% +twice. So you can count this edge three +times or whatever you want, how many + + align:start position:0% +times or whatever you want, how many + + + align:start position:0% +times or whatever you want, how many +however many times you want. So that's + + align:start position:0% +however many times you want. So that's + + + align:start position:0% +however many times you want. So that's +the definition. So now we want to find a + + align:start position:0% +the definition. So now we want to find a + + + align:start position:0% +the definition. So now we want to find a +cycle which goes through all the + + align:start position:0% +cycle which goes through all the + + + align:start position:0% +cycle which goes through all the +vertices and we want to minimize the + + align:start position:0% +vertices and we want to minimize the + + + align:start position:0% +vertices and we want to minimize the +cost of that cycle. So let's say your + + align:start position:0% +cost of that cycle. So let's say your + + + align:start position:0% +cost of that cycle. So let's say your +optimal so this is this should remind + + align:start position:0% +optimal so this is this should remind + + + align:start position:0% +optimal so this is this should remind +you of the Hamiltonian cycle problem. So + + align:start position:0% +you of the Hamiltonian cycle problem. So + + + align:start position:0% +you of the Hamiltonian cycle problem. So +this is essentially finding a + + align:start position:0% +this is essentially finding a + + + align:start position:0% +this is essentially finding a +Hamiltonian cycle in the graph of + + align:start position:0% +Hamiltonian cycle in the graph of + + + align:start position:0% +Hamiltonian cycle in the graph of +minimum weight. So this is worse than + + align:start position:0% +minimum weight. So this is worse than + + + align:start position:0% +minimum weight. So this is worse than +the Hamiltonian cycle problem. This is + + align:start position:0% +the Hamiltonian cycle problem. This is + + + align:start position:0% +the Hamiltonian cycle problem. This is +finding the minimum weight Hamiltonian + + align:start position:0% +finding the minimum weight Hamiltonian + + + align:start position:0% +finding the minimum weight Hamiltonian +cycle. Okay. So let's say there exists + + align:start position:0% +cycle. Okay. So let's say there exists + + + align:start position:0% +cycle. Okay. So let's say there exists +this beautiful Hamiltonian cycle which + + align:start position:0% +this beautiful Hamiltonian cycle which + + + align:start position:0% +this beautiful Hamiltonian cycle which +is min you know of is of minimum weight. + + align:start position:0% +is min you know of is of minimum weight. + + + align:start position:0% +is min you know of is of minimum weight. +Let's call that h star g. So it's the + + align:start position:0% +Let's call that h star g. So it's the + + + align:start position:0% +Let's call that h star g. So it's the +best Hamiltonian cycle on this graph and + + align:start position:0% +best Hamiltonian cycle on this graph and + + + align:start position:0% +best Hamiltonian cycle on this graph and +that's the shortest path that your + + align:start position:0% +that's the shortest path that your + + + align:start position:0% +that's the shortest path that your +traveling salesman can take. And so the + + align:start position:0% +traveling salesman can take. And so the + + + align:start position:0% +traveling salesman can take. And so the +cost of that is given by cf sg. Okay. So + + align:start position:0% +cost of that is given by cf sg. Okay. So + + + align:start position:0% +cost of that is given by cf sg. Okay. So +how do we go about trying to approximate + + align:start position:0% +how do we go about trying to approximate + + + align:start position:0% +how do we go about trying to approximate +this problem? So think about what + + align:start position:0% +this problem? So think about what + + + align:start position:0% +this problem? So think about what +algorithms you've seen that can that + + align:start position:0% +algorithms you've seen that can that + + + align:start position:0% +algorithms you've seen that can that +sort of connect all the vertices of a + + align:start position:0% +sort of connect all the vertices of a + + + align:start position:0% +sort of connect all the vertices of a +graph and minimize costs of edges. + + align:start position:0% +graph and minimize costs of edges. + + + align:start position:0% +graph and minimize costs of edges. +Remind you of anything polomial that + + align:start position:0% +Remind you of anything polomial that + + + align:start position:0% +Remind you of anything polomial that +you've seen in the class that connects + + align:start position:0% +you've seen in the class that connects + + + align:start position:0% +you've seen in the class that connects +all the vertices + + align:start position:0% + + + + align:start position:0% + +spans all the vertices. + + align:start position:0% +spans all the vertices. + + + align:start position:0% +spans all the vertices. +Exactly. So Chris call min spanning + + align:start position:0% +Exactly. So Chris call min spanning + + + align:start position:0% +Exactly. So Chris call min spanning +tree. So min spanning tree is polomial + + align:start position:0% +tree. So min spanning tree is polomial + + + align:start position:0% +tree. So min spanning tree is polomial +time and it connects all the vertex + + align:start position:0% +time and it connects all the vertex + + + align:start position:0% +time and it connects all the vertex +vert. So let's let's take some graph. + + align:start position:0% +vert. So let's let's take some graph. + + + align:start position:0% +vert. So let's let's take some graph. +Let's just go with this one. So you have + + align:start position:0% +Let's just go with this one. So you have + + + align:start position:0% +Let's just go with this one. So you have +some + + align:start position:0% +some + + + align:start position:0% +some +vertices and you connect you make a + + align:start position:0% +vertices and you connect you make a + + + align:start position:0% +vertices and you connect you make a +minimum spanning tree out of them. + + align:start position:0% +minimum spanning tree out of them. + + + align:start position:0% +minimum spanning tree out of them. +Now clearly this is not a cycle yet. But + + align:start position:0% +Now clearly this is not a cycle yet. But + + + align:start position:0% +Now clearly this is not a cycle yet. But +let's try to construct a path out of + + align:start position:0% +let's try to construct a path out of + + + align:start position:0% +let's try to construct a path out of +this minimum spanning tree. + + align:start position:0% +this minimum spanning tree. + + + align:start position:0% +this minimum spanning tree. +So first let's root it. So let's say we + + align:start position:0% +So first let's root it. So let's say we + + + align:start position:0% +So first let's root it. So let's say we +have rooted minimum spanning tree. + + align:start position:0% +have rooted minimum spanning tree. + + + align:start position:0% +have rooted minimum spanning tree. +Let's say this is the root. So you have + + align:start position:0% +Let's say this is the root. So you have + + + align:start position:0% +Let's say this is the root. So you have +three things coming out of there. I + + align:start position:0% +three things coming out of there. I + + + align:start position:0% +three things coming out of there. I +think that's it. Okay. So let's give + + align:start position:0% +think that's it. Okay. So let's give + + + align:start position:0% +think that's it. Okay. So let's give +these labels. + + align:start position:0% + + + + align:start position:0% + +So now what we're going to do is the way + + align:start position:0% +So now what we're going to do is the way + + + align:start position:0% +So now what we're going to do is the way +we're going to traverse all the + + align:start position:0% +we're going to traverse all the + + + align:start position:0% +we're going to traverse all the +vertices. Let's just do a DFS. So in DFS + + align:start position:0% +vertices. Let's just do a DFS. So in DFS + + + align:start position:0% +vertices. Let's just do a DFS. So in DFS +traversal you'll first C1 + + align:start position:0% +traversal you'll first C1 + + + align:start position:0% +traversal you'll first C1 +then you'll go down in C2 + + align:start position:0% +then you'll go down in C2 + + + align:start position:0% +then you'll go down in C2 +then go down in C3 + + align:start position:0% +then go down in C3 + + + align:start position:0% +then go down in C3 +then you'll go back up C2 again then go + + align:start position:0% +then you'll go back up C2 again then go + + + align:start position:0% +then you'll go back up C2 again then go +back down C4 go back up C2 one 5 1 6 so + + align:start position:0% +back down C4 go back up C2 one 5 1 6 so + + + align:start position:0% +back down C4 go back up C2 one 5 1 6 so +basically you're ignoring the rest of + + align:start position:0% +basically you're ignoring the rest of + + + align:start position:0% +basically you're ignoring the rest of +the graph you find your minimum spanning + + align:start position:0% +the graph you find your minimum spanning + + + align:start position:0% +the graph you find your minimum spanning +tree and you follow all the paths follow + + align:start position:0% +tree and you follow all the paths follow + + + align:start position:0% +tree and you follow all the paths follow +them back up and just do a DFS reversal + + align:start position:0% +them back up and just do a DFS reversal + + + align:start position:0% +them back up and just do a DFS reversal +and that is and then you go reach back + + align:start position:0% +and that is and then you go reach back + + + align:start position:0% +and that is and then you go reach back +to one I think And then you have this + + align:start position:0% +to one I think And then you have this + + + align:start position:0% +to one I think And then you have this +well it visits all the vertices. It + + align:start position:0% +well it visits all the vertices. It + + + align:start position:0% +well it visits all the vertices. It +visits some of them more than once which + + align:start position:0% +visits some of them more than once which + + + align:start position:0% +visits some of them more than once which +is a problem which we'll deal with + + align:start position:0% +is a problem which we'll deal with + + + align:start position:0% +is a problem which we'll deal with +shortly. But it visits all the vertices + + align:start position:0% +shortly. But it visits all the vertices + + + align:start position:0% +shortly. But it visits all the vertices +and it's a cycle. So now the problem is + + align:start position:0% +and it's a cycle. So now the problem is + + + align:start position:0% +and it's a cycle. So now the problem is +the travel and salesman problem does not + + align:start position:0% +the travel and salesman problem does not + + + align:start position:0% +the travel and salesman problem does not +allow you to visit vertices more than + + align:start position:0% +allow you to visit vertices more than + + + align:start position:0% +allow you to visit vertices more than +once because if you did not have this + + align:start position:0% +once because if you did not have this + + + align:start position:0% +once because if you did not have this +restriction you could shorten your path + + align:start position:0% +restriction you could shorten your path + + + align:start position:0% +restriction you could shorten your path +length by going to a separate vertex and + + align:start position:0% +length by going to a separate vertex and + + + align:start position:0% +length by going to a separate vertex and +coming back or something like that. So + + align:start position:0% +coming back or something like that. So + + + align:start position:0% +coming back or something like that. So +let's make that more concrete. So at + + align:start position:0% +let's make that more concrete. So at + + + align:start position:0% +let's make that more concrete. So at +least so in this case given this + + align:start position:0% +least so in this case given this + + + align:start position:0% +least so in this case given this +triangle inequality I claim that + + align:start position:0% +triangle inequality I claim that + + + align:start position:0% +triangle inequality I claim that +you can just delete the duplicate + + align:start position:0% +you can just delete the duplicate + + + align:start position:0% +you can just delete the duplicate +vertices. So let's look at the duplicate + + align:start position:0% +vertices. So let's look at the duplicate + + + align:start position:0% +vertices. So let's look at the duplicate +ones. You have 1 2 3 this repeats. So + + align:start position:0% +ones. You have 1 2 3 this repeats. So + + + align:start position:0% +ones. You have 1 2 3 this repeats. So +you delete that repeats repeats repeats + + align:start position:0% +you delete that repeats repeats repeats + + + align:start position:0% +you delete that repeats repeats repeats +and that's cycling back. So how do you + + align:start position:0% +and that's cycling back. So how do you + + + align:start position:0% +and that's cycling back. So how do you +delete things? So in this case you had a + + align:start position:0% +delete things? So in this case you had a + + + align:start position:0% +delete things? So in this case you had a +path right? You were going to one to two + + align:start position:0% +path right? You were going to one to two + + + align:start position:0% +path right? You were going to one to two +and two to three + + align:start position:0% +and two to three + + + align:start position:0% +and two to three +to two and so on. So + + align:start position:0% +to two and so on. So + + + align:start position:0% +to two and so on. So +let's draw the four in. So this is + + align:start position:0% +let's draw the four in. So this is + + + align:start position:0% +let's draw the four in. So this is +following only the tree edges. So how + + align:start position:0% +following only the tree edges. So how + + + align:start position:0% +following only the tree edges. So how +would you delete this? So let's say you + + align:start position:0% +would you delete this? So let's say you + + + align:start position:0% +would you delete this? So let's say you +find the first duplicate vertex and you + + align:start position:0% +find the first duplicate vertex and you + + + align:start position:0% +find the first duplicate vertex and you +don't want that. That's not allowed. So + + align:start position:0% +don't want that. That's not allowed. So + + + align:start position:0% +don't want that. That's not allowed. So +all you do is simply you follow the path + + align:start position:0% +all you do is simply you follow the path + + + align:start position:0% +all you do is simply you follow the path +and you bypass it. And by the triangle + + align:start position:0% +and you bypass it. And by the triangle + + + align:start position:0% +and you bypass it. And by the triangle +inequality, you know that bypassing it + + align:start position:0% +inequality, you know that bypassing it + + + align:start position:0% +inequality, you know that bypassing it +will will never increase your cost. + + align:start position:0% +will will never increase your cost. + + + align:start position:0% +will will never increase your cost. +It'll decrease it or like keep it the + + align:start position:0% +It'll decrease it or like keep it the + + + align:start position:0% +It'll decrease it or like keep it the +same. So you can remove the duplicate + + align:start position:0% +same. So you can remove the duplicate + + + align:start position:0% +same. So you can remove the duplicate +vertex in this path just bypassing it + + align:start position:0% +vertex in this path just bypassing it + + + align:start position:0% +vertex in this path just bypassing it +with also remember that this is a + + align:start position:0% +with also remember that this is a + + + align:start position:0% +with also remember that this is a +complete graph. So a metric is defined + + align:start position:0% +complete graph. So a metric is defined + + + align:start position:0% +complete graph. So a metric is defined +on all pairs of vertices. So every edge + + align:start position:0% +on all pairs of vertices. So every edge + + + align:start position:0% +on all pairs of vertices. So every edge +exists with some value. + + align:start position:0% +exists with some value. + + + align:start position:0% +exists with some value. +So that also follows by the triangle + + align:start position:0% +So that also follows by the triangle + + + align:start position:0% +So that also follows by the triangle +inequality. So if an edge does not + + align:start position:0% +inequality. So if an edge does not + + + align:start position:0% +inequality. So if an edge does not +exist, just make it the sum of the So if + + align:start position:0% +exist, just make it the sum of the So if + + + align:start position:0% +exist, just make it the sum of the So if +XZ is not an edge, just make it the sum + + align:start position:0% +XZ is not an edge, just make it the sum + + + align:start position:0% +XZ is not an edge, just make it the sum +of XY plus YZ. + + align:start position:0% +of XY plus YZ. + + + align:start position:0% +of XY plus YZ. +So in any case, so so you construct the + + align:start position:0% +So in any case, so so you construct the + + + align:start position:0% +So in any case, so so you construct the +an initial path just by going down the + + align:start position:0% +an initial path just by going down the + + + align:start position:0% +an initial path just by going down the +tree and doing a naive DFS reversal and + + align:start position:0% +tree and doing a naive DFS reversal and + + + align:start position:0% +tree and doing a naive DFS reversal and +then you correct that path by skipping + + align:start position:0% +then you correct that path by skipping + + + align:start position:0% +then you correct that path by skipping +over the duplicates. So finally you'll + + align:start position:0% +over the duplicates. So finally you'll + + + align:start position:0% +over the duplicates. So finally you'll +end up with after skipping over the + + align:start position:0% +end up with after skipping over the + + + align:start position:0% +end up with after skipping over the +duplicates you get a 1 2 3 4 5 6 1 and + + align:start position:0% +duplicates you get a 1 2 3 4 5 6 1 and + + + align:start position:0% +duplicates you get a 1 2 3 4 5 6 1 and +that's a valid cycle right. So so let's + + align:start position:0% +that's a valid cycle right. So so let's + + + align:start position:0% +that's a valid cycle right. So so let's +call this minimum spanning tree t. + + align:start position:0% +call this minimum spanning tree t. + + + align:start position:0% +call this minimum spanning tree t. +So that's your mst + + align:start position:0% + + + + align:start position:0% + +and you are removing duplicate edges and + + align:start position:0% +and you are removing duplicate edges and + + + align:start position:0% +and you are removing duplicate edges and +getting a cycle c let's say. + + align:start position:0% +getting a cycle c let's say. + + + align:start position:0% +getting a cycle c let's say. +So now you know that um actually let's + + align:start position:0% +So now you know that um actually let's + + + align:start position:0% +So now you know that um actually let's +take another step back. Let's say okay + + align:start position:0% +take another step back. Let's say okay + + + align:start position:0% +take another step back. Let's say okay +let's say let's define + + align:start position:0% +let's say let's define + + + align:start position:0% +let's say let's define +let's define a cycle first which is so + + align:start position:0% +let's define a cycle first which is so + + + align:start position:0% +let's define a cycle first which is so +let's say let's call this cycle + + align:start position:0% +let's say let's call this cycle + + + align:start position:0% +let's say let's call this cycle +this guy is C + + align:start position:0% +this guy is C + + + align:start position:0% +this guy is C +and then you're going from C and you're + + align:start position:0% +and then you're going from C and you're + + + align:start position:0% +and then you're going from C and you're +deleting the duplicates and you're + + align:start position:0% +deleting the duplicates and you're + + + align:start position:0% +deleting the duplicates and you're +getting C dash + + align:start position:0% +getting C dash + + + align:start position:0% +getting C dash +so now what you have is + + align:start position:0% +so now what you have is + + + align:start position:0% +so now what you have is +cost of + + align:start position:0% +cost of + + + align:start position:0% +cost of +C dash it's a valation but anyway Okay, + + align:start position:0% +C dash it's a valation but anyway Okay, + + + align:start position:0% +C dash it's a valation but anyway Okay, +the cost of C dash is less than equal to + + align:start position:0% +the cost of C dash is less than equal to + + + align:start position:0% +the cost of C dash is less than equal to +cost of C. And what is the cost of C? + + align:start position:0% +cost of C. And what is the cost of C? + + + align:start position:0% +cost of C. And what is the cost of C? +If you know the weight of your minimum + + align:start position:0% +If you know the weight of your minimum + + + align:start position:0% +If you know the weight of your minimum +spanning tree, what is the cost of C? C + + align:start position:0% +spanning tree, what is the cost of C? C + + + align:start position:0% +spanning tree, what is the cost of C? C +is just doing a GFS reversal. So what is + + align:start position:0% +is just doing a GFS reversal. So what is + + + align:start position:0% +is just doing a GFS reversal. So what is +the cost of C? + + align:start position:0% +the cost of C? + + + align:start position:0% +the cost of C? +If you have if you know your minimum + + align:start position:0% +If you have if you know your minimum + + + align:start position:0% +If you have if you know your minimum +spanning tree, + + align:start position:0% + + + + align:start position:0% + +no. So you're traversing every edge on + + align:start position:0% +no. So you're traversing every edge on + + + align:start position:0% +no. So you're traversing every edge on +the minimum spanning tree twice. So + + align:start position:0% +the minimum spanning tree twice. So + + + align:start position:0% +the minimum spanning tree twice. So +you're doing a DFS travers, right? So + + align:start position:0% +you're doing a DFS travers, right? So + + + align:start position:0% +you're doing a DFS travers, right? So +you're going down, you're coming back + + align:start position:0% +you're going down, you're coming back + + + align:start position:0% +you're going down, you're coming back +up. It's like you're going down, coming + + align:start position:0% +up. It's like you're going down, coming + + + align:start position:0% +up. It's like you're going down, coming +back up, backtracking, going back down. + + align:start position:0% +back up, backtracking, going back down. + + + align:start position:0% +back up, backtracking, going back down. +So every edge is reversed twice. So it's + + align:start position:0% +So every edge is reversed twice. So it's + + + align:start position:0% +So every edge is reversed twice. So it's +exactly twice D. So let's bring up a + + align:start position:0% +exactly twice D. So let's bring up a + + + align:start position:0% +exactly twice D. So let's bring up a +different board. + + align:start position:0% + + + + align:start position:0% + +So you know that cost of C is twice the + + align:start position:0% +So you know that cost of C is twice the + + + align:start position:0% +So you know that cost of C is twice the +cost of T. Does that make sense? Why the + + align:start position:0% +cost of T. Does that make sense? Why the + + + align:start position:0% +cost of T. Does that make sense? Why the +traversal implies that you have every + + align:start position:0% +traversal implies that you have every + + + align:start position:0% +traversal implies that you have every +edge being visited twice, right? Okay. + + align:start position:0% +edge being visited twice, right? Okay. + + + align:start position:0% +edge being visited twice, right? Okay. +So + + align:start position:0% +So + + + align:start position:0% +So +now our claim is that the C dash cycle + + align:start position:0% +now our claim is that the C dash cycle + + + align:start position:0% +now our claim is that the C dash cycle +is uh two approximation of the actual + + align:start position:0% +is uh two approximation of the actual + + + align:start position:0% +is uh two approximation of the actual +Hamilton actual cycle. So why is that? + + align:start position:0% +Hamilton actual cycle. So why is that? + + + align:start position:0% +Hamilton actual cycle. So why is that? +So we already proved. So this impli also + + align:start position:0% +So we already proved. So this impli also + + + align:start position:0% +So we already proved. So this impli also +implies that C of C dash is less than + + align:start position:0% +implies that C of C dash is less than + + + align:start position:0% +implies that C of C dash is less than +equal to 2 of CT. + + align:start position:0% +equal to 2 of CT. + + + align:start position:0% +equal to 2 of CT. +Realize that this is not a valid cycle + + align:start position:0% +Realize that this is not a valid cycle + + + align:start position:0% +Realize that this is not a valid cycle +but this is a valid cycle. Okay. So now + + align:start position:0% +but this is a valid cycle. Okay. So now + + + align:start position:0% +but this is a valid cycle. Okay. So now +we need to show that this is somehow + + align:start position:0% +we need to show that this is somehow + + + align:start position:0% +we need to show that this is somehow +bounded by H star G. So how do you do + + align:start position:0% +bounded by H star G. So how do you do + + + align:start position:0% +bounded by H star G. So how do you do +that? Well, look at HRG. What is HRG? + + align:start position:0% +that? Well, look at HRG. What is HRG? + + + align:start position:0% +that? Well, look at HRG. What is HRG? +HRG is just a cycle which goes the + + align:start position:0% +HRG is just a cycle which goes the + + + align:start position:0% +HRG is just a cycle which goes the +optimal cycle which goes through all the + + align:start position:0% +optimal cycle which goes through all the + + + align:start position:0% +optimal cycle which goes through all the +vertices and comes back to the parent + + align:start position:0% +vertices and comes back to the parent + + + align:start position:0% +vertices and comes back to the parent +vertex. So what you can do? So this is a + + align:start position:0% +vertex. So what you can do? So this is a + + + align:start position:0% +vertex. So what you can do? So this is a +star of G. This is the optimal thing. + + align:start position:0% +star of G. This is the optimal thing. + + + align:start position:0% +star of G. This is the optimal thing. +Now you can take an edge E here and + + align:start position:0% +Now you can take an edge E here and + + + align:start position:0% +Now you can take an edge E here and +delete it and then you will get a + + align:start position:0% +delete it and then you will get a + + + align:start position:0% +delete it and then you will get a +spanning tree because this is your + + align:start position:0% +spanning tree because this is your + + + align:start position:0% +spanning tree because this is your +optimal cycle. Remove one edge and you + + align:start position:0% +optimal cycle. Remove one edge and you + + + align:start position:0% +optimal cycle. Remove one edge and you +get a spanning tree. So let's call that + + align:start position:0% +get a spanning tree. So let's call that + + + align:start position:0% +get a spanning tree. So let's call that +t ddash. + + align:start position:0% + + + + align:start position:0% + +Does that make sense why that is a + + align:start position:0% +Does that make sense why that is a + + + align:start position:0% +Does that make sense why that is a +spanning tree? Because you had a cycle + + align:start position:0% +spanning tree? Because you had a cycle + + + align:start position:0% +spanning tree? Because you had a cycle +and you move one edge. So it's touches + + align:start position:0% +and you move one edge. So it's touches + + + align:start position:0% +and you move one edge. So it's touches +all the vertices and has and it's a + + align:start position:0% +all the vertices and has and it's a + + + align:start position:0% +all the vertices and has and it's a +tree. So it's a spanning tree but it's + + align:start position:0% +tree. So it's a spanning tree but it's + + + align:start position:0% +tree. So it's a spanning tree but it's +not the minimum spanning tree. So you + + align:start position:0% +not the minimum spanning tree. So you + + + align:start position:0% +not the minimum spanning tree. So you +know that + + align:start position:0% +know that + + + align:start position:0% +know that +H star G the cost of H star of G + + align:start position:0% +H star G the cost of H star of G + + + align:start position:0% +H star G the cost of H star of G +is greater than equal to the cost of H + + align:start position:0% +is greater than equal to the cost of H + + + align:start position:0% +is greater than equal to the cost of H +star of G minus the edge we removed + + align:start position:0% +star of G minus the edge we removed + + + align:start position:0% +star of G minus the edge we removed +is greater than equal to the cost of T. + + align:start position:0% +is greater than equal to the cost of T. + + + align:start position:0% +is greater than equal to the cost of T. +Make sense? So you removed one edge and + + align:start position:0% +Make sense? So you removed one edge and + + + align:start position:0% +Make sense? So you removed one edge and +then that that is still greater than the + + align:start position:0% +then that that is still greater than the + + + align:start position:0% +then that that is still greater than the +minimum spanning tree. So now combining + + align:start position:0% +minimum spanning tree. So now combining + + + align:start position:0% +minimum spanning tree. So now combining +this guy and this guy you get cost of C + + align:start position:0% +this guy and this guy you get cost of C + + + align:start position:0% +this guy and this guy you get cost of C +dash is less than equal to 2 * cost of + + align:start position:0% +dash is less than equal to 2 * cost of + + + align:start position:0% +dash is less than equal to 2 * cost of +C. But you know cost of C is less than + + align:start position:0% +C. But you know cost of C is less than + + + align:start position:0% +C. But you know cost of C is less than +cost of H of G. So you get a two + + align:start position:0% +cost of H of G. So you get a two + + + align:start position:0% +cost of H of G. So you get a two +approximation. + + align:start position:0% + + + + align:start position:0% + +So does that make sense? + + align:start position:0% + + + + align:start position:0% + +Okay. Okay. So that was a true + + align:start position:0% +Okay. Okay. So that was a true + + + align:start position:0% +Okay. Okay. So that was a true +approximation. That was pretty + + align:start position:0% +approximation. That was pretty + + + align:start position:0% +approximation. That was pretty +straightforward. You just constructed a + + align:start position:0% +straightforward. You just constructed a + + + align:start position:0% +straightforward. You just constructed a +spanning tree. You did a DFS reversal, + + align:start position:0% +spanning tree. You did a DFS reversal, + + + align:start position:0% +spanning tree. You did a DFS reversal, +remove duplicates, and you have a nice + + align:start position:0% +remove duplicates, and you have a nice + + + align:start position:0% +remove duplicates, and you have a nice +path. + + align:start position:0% +path. + + + align:start position:0% +path. +But okay, let's just leave it down. + + align:start position:0% +But okay, let's just leave it down. + + + align:start position:0% +But okay, let's just leave it down. +But here's the thing. It seems kind of + + align:start position:0% +But here's the thing. It seems kind of + + + align:start position:0% +But here's the thing. It seems kind of +wasteful to go through all the edges + + align:start position:0% +wasteful to go through all the edges + + + align:start position:0% +wasteful to go through all the edges +when you don't need to. So you're + + align:start position:0% +when you don't need to. So you're + + + align:start position:0% +when you don't need to. So you're +traveling down the tree, you're going + + align:start position:0% +traveling down the tree, you're going + + + align:start position:0% +traveling down the tree, you're going +back up, and you're you're traversing + + align:start position:0% +back up, and you're you're traversing + + + align:start position:0% +back up, and you're you're traversing +every edge twice. So it seems kind of + + align:start position:0% +every edge twice. So it seems kind of + + + align:start position:0% +every edge twice. So it seems kind of +ridiculous that you would be doing every + + align:start position:0% +ridiculous that you would be doing every + + + align:start position:0% +ridiculous that you would be doing every +edge twice. Doesn't So what could you do + + align:start position:0% +edge twice. Doesn't So what could you do + + + align:start position:0% +edge twice. Doesn't So what could you do +better? Well, + + align:start position:0% +better? Well, + + + align:start position:0% +better? Well, +before we introduce that, let's prove a + + align:start position:0% +before we introduce that, let's prove a + + + align:start position:0% +before we introduce that, let's prove a +couple of lemmas, + + align:start position:0% +couple of lemmas, + + + align:start position:0% +couple of lemmas, +let's so first + + align:start position:0% +let's so first + + + align:start position:0% +let's so first +we + + align:start position:0% +we + + + align:start position:0% +we +we start with this. So let's say S is a + + align:start position:0% +we start with this. So let's say S is a + + + align:start position:0% +we start with this. So let's say S is a +subset of V. So you have a graph + + align:start position:0% +subset of V. So you have a graph + + + align:start position:0% +subset of V. So you have a graph +and you take make a subgraph. So you so + + align:start position:0% +and you take make a subgraph. So you so + + + align:start position:0% +and you take make a subgraph. So you so +you pick out some vertices. So pick out + + align:start position:0% +you pick out some vertices. So pick out + + + align:start position:0% +you pick out some vertices. So pick out +this one and this one and this one and + + align:start position:0% +this one and this one and this one and + + + align:start position:0% +this one and this one and this one and +this one and that is your S. + + align:start position:0% +this one and that is your S. + + + align:start position:0% +this one and that is your S. +And so you get a new graph which + + align:start position:0% +And so you get a new graph which + + + align:start position:0% +And so you get a new graph which +contains just those vertices + + align:start position:0% +contains just those vertices + + + align:start position:0% +contains just those vertices +and whatever edges connect them. + + align:start position:0% +and whatever edges connect them. + + + align:start position:0% +and whatever edges connect them. +So the claim is that that that graph + + align:start position:0% +So the claim is that that that graph + + + align:start position:0% +So the claim is that that that graph +also has a Hamiltonian cycle the minimum + + align:start position:0% +also has a Hamiltonian cycle the minimum + + + align:start position:0% +also has a Hamiltonian cycle the minimum +cost Hamiltonian cycle which is also the + + align:start position:0% +cost Hamiltonian cycle which is also the + + + align:start position:0% +cost Hamiltonian cycle which is also the +traveling salesman solution. So let's + + align:start position:0% +traveling salesman solution. So let's + + + align:start position:0% +traveling salesman solution. So let's +call that h star of s. So is some cycle + + align:start position:0% +call that h star of s. So is some cycle + + + align:start position:0% +call that h star of s. So is some cycle +which looks like this I guess here. So h + + align:start position:0% +which looks like this I guess here. So h + + + align:start position:0% +which looks like this I guess here. So h +star of s. Now the claim is that the + + align:start position:0% +star of s. Now the claim is that the + + + align:start position:0% +star of s. Now the claim is that the +cost of h star of s is less than equal + + align:start position:0% +cost of h star of s is less than equal + + + align:start position:0% +cost of h star of s is less than equal +to cost of h star of g. That should make + + align:start position:0% +to cost of h star of g. That should make + + + align:start position:0% +to cost of h star of g. That should make +intuitive sense because you're taking + + align:start position:0% +intuitive sense because you're taking + + + align:start position:0% +intuitive sense because you're taking +only some of the vertices and trying to + + align:start position:0% +only some of the vertices and trying to + + + align:start position:0% +only some of the vertices and trying to +traverse them. And in this case you're + + align:start position:0% +traverse them. And in this case you're + + + align:start position:0% +traverse them. And in this case you're +trying to traverse all the vertices. + + align:start position:0% +trying to traverse all the vertices. + + + align:start position:0% +trying to traverse all the vertices. +However, this is not this is not this is + + align:start position:0% +However, this is not this is not this is + + + align:start position:0% +However, this is not this is not this is +only true because of the triangle + + align:start position:0% +only true because of the triangle + + + align:start position:0% +only true because of the triangle +inequality. And let's see why that is + + align:start position:0% +inequality. And let's see why that is + + + align:start position:0% +inequality. And let's see why that is +the case. + + align:start position:0% +the case. + + + align:start position:0% +the case. +So let's say let's so proof by + + align:start position:0% +So let's say let's so proof by + + + align:start position:0% +So let's say let's so proof by +contradiction. + + align:start position:0% +contradiction. + + + align:start position:0% +contradiction. +Say + + align:start position:0% +Say + + + align:start position:0% +Say +cost of + + align:start position:0% +cost of + + + align:start position:0% +cost of +har of s is actually greater than cost + + align:start position:0% +har of s is actually greater than cost + + + align:start position:0% +har of s is actually greater than cost +of h star of g. + + align:start position:0% +of h star of g. + + + align:start position:0% +of h star of g. +Okay. So look at h star of g. It's a + + align:start position:0% +Okay. So look at h star of g. It's a + + + align:start position:0% +Okay. So look at h star of g. It's a +cycle, right? So you have something that + + align:start position:0% +cycle, right? So you have something that + + + align:start position:0% +cycle, right? So you have something that +your cycle and in this cycle you have + + align:start position:0% +your cycle and in this cycle you have + + + align:start position:0% +your cycle and in this cycle you have +all the vertices of s. So pick them out. + + align:start position:0% + + + + align:start position:0% + +And now so you have a cycle which has + + align:start position:0% +And now so you have a cycle which has + + + align:start position:0% +And now so you have a cycle which has +cost less than the optimal cycle in S + + align:start position:0% +cost less than the optimal cycle in S + + + align:start position:0% +cost less than the optimal cycle in S +but it contains all the vertices in S. + + align:start position:0% +but it contains all the vertices in S. + + + align:start position:0% +but it contains all the vertices in S. +So what you can do is now you can use + + align:start position:0% +So what you can do is now you can use + + + align:start position:0% +So what you can do is now you can use +the skipping lema from before. So + + align:start position:0% +the skipping lema from before. So + + + align:start position:0% +the skipping lema from before. So +instead of so last time you remove + + align:start position:0% +instead of so last time you remove + + + align:start position:0% +instead of so last time you remove +duplicate vertices but this time what + + align:start position:0% +duplicate vertices but this time what + + + align:start position:0% +duplicate vertices but this time what +you'll do is instead you'll just skip + + align:start position:0% +you'll do is instead you'll just skip + + + align:start position:0% +you'll do is instead you'll just skip +over this vertex and you'll skip over + + align:start position:0% +over this vertex and you'll skip over + + + align:start position:0% +over this vertex and you'll skip over +this vertex and so every vertex that's + + align:start position:0% +this vertex and so every vertex that's + + + align:start position:0% +this vertex and so every vertex that's +not an S skip over it and that can only + + align:start position:0% +not an S skip over it and that can only + + + align:start position:0% +not an S skip over it and that can only +decrease the cost. So now you've + + align:start position:0% +decrease the cost. So now you've + + + align:start position:0% +decrease the cost. So now you've +constructed another cycle which contains + + align:start position:0% +constructed another cycle which contains + + + align:start position:0% +constructed another cycle which contains +only the vertices of S. So it's a + + align:start position:0% +only the vertices of S. So it's a + + + align:start position:0% +only the vertices of S. So it's a +Hamiltonian cycle for S but it has cost + + align:start position:0% +Hamiltonian cycle for S but it has cost + + + align:start position:0% +Hamiltonian cycle for S but it has cost +less than equals H star G which means + + align:start position:0% +less than equals H star G which means + + + align:start position:0% +less than equals H star G which means +that this this can never be true. So + + align:start position:0% +that this this can never be true. So + + + align:start position:0% +that this this can never be true. So +that is the reason so so the important + + align:start position:0% +that is the reason so so the important + + + align:start position:0% +that is the reason so so the important +fact is there that if you have a subset + + align:start position:0% +fact is there that if you have a subset + + + align:start position:0% +fact is there that if you have a subset +of vertices making the the restricted + + align:start position:0% +of vertices making the the restricted + + + align:start position:0% +of vertices making the the restricted +graph the Hamiltonian cycle is always + + align:start position:0% +graph the Hamiltonian cycle is always + + + align:start position:0% +graph the Hamiltonian cycle is always +less than equal to the cost of the + + align:start position:0% +less than equal to the cost of the + + + align:start position:0% +less than equal to the cost of the +Hamilton minimum Hamiltonian cycle is + + align:start position:0% +Hamilton minimum Hamiltonian cycle is + + + align:start position:0% +Hamilton minimum Hamiltonian cycle is +always less than equal to the one in the + + align:start position:0% +always less than equal to the one in the + + + align:start position:0% +always less than equal to the one in the +original graph. So intuitively that + + align:start position:0% +original graph. So intuitively that + + + align:start position:0% +original graph. So intuitively that +should make sense. That's the proof. + + align:start position:0% +should make sense. That's the proof. + + + align:start position:0% +should make sense. That's the proof. +Okay, + + align:start position:0% +Okay, + + + align:start position:0% +Okay, +next thing is something which might seem + + align:start position:0% +next thing is something which might seem + + + align:start position:0% +next thing is something which might seem +unrelated right now. Uh + + align:start position:0% +unrelated right now. Uh + + + align:start position:0% +unrelated right now. Uh +perfect matchings. + + align:start position:0% + + + + align:start position:0% + +So, so we've seen perfect matchings in + + align:start position:0% +So, so we've seen perfect matchings in + + + align:start position:0% +So, so we've seen perfect matchings in +the context of bipartite graphs, right? + + align:start position:0% +the context of bipartite graphs, right? + + + align:start position:0% +the context of bipartite graphs, right? +So, you find the minimum cost perfect + + align:start position:0% +So, you find the minimum cost perfect + + + align:start position:0% +So, you find the minimum cost perfect +matching. You do this flow thing. You + + align:start position:0% +matching. You do this flow thing. You + + + align:start position:0% +matching. You do this flow thing. You +send all the flow in and then you + + align:start position:0% +send all the flow in and then you + + + align:start position:0% +send all the flow in and then you +connect the vertices with the capacities + + align:start position:0% +connect the vertices with the capacities + + + align:start position:0% +connect the vertices with the capacities +and whatever. So turns out in a complete + + align:start position:0% +and whatever. So turns out in a complete + + + align:start position:0% +and whatever. So turns out in a complete +graph + + align:start position:0% +graph + + + align:start position:0% +graph +uh you can still do perfect matching. So + + align:start position:0% +uh you can still do perfect matching. So + + + align:start position:0% +uh you can still do perfect matching. So +perfect matching is you have a bunch of + + align:start position:0% +perfect matching is you have a bunch of + + + align:start position:0% +perfect matching is you have a bunch of +so let's say you need to have an even + + align:start position:0% +so let's say you need to have an even + + + align:start position:0% +so let's say you need to have an even +number of vertices right have perfect + + align:start position:0% +number of vertices right have perfect + + + align:start position:0% +number of vertices right have perfect +matching. So let's say you have these + + align:start position:0% +matching. So let's say you have these + + + align:start position:0% +matching. So let's say you have these +vertices and so this is the perfect + + align:start position:0% +vertices and so this is the perfect + + + align:start position:0% +vertices and so this is the perfect +matching. So every vertex has one edge + + align:start position:0% +matching. So every vertex has one edge + + + align:start position:0% +matching. So every vertex has one edge +coming out of it uh exactly one edge + + align:start position:0% +coming out of it uh exactly one edge + + + align:start position:0% +coming out of it uh exactly one edge +coming out of it and it needs to be even + + align:start position:0% +coming out of it and it needs to be even + + + align:start position:0% +coming out of it and it needs to be even +because otherwise it doesn't work out. + + align:start position:0% +because otherwise it doesn't work out. + + + align:start position:0% +because otherwise it doesn't work out. +So that's perfect matching and the + + align:start position:0% +So that's perfect matching and the + + + align:start position:0% +So that's perfect matching and the +minimum cost perfect matching is the + + align:start position:0% +minimum cost perfect matching is the + + + align:start position:0% +minimum cost perfect matching is the +minimum among among all all such things + + align:start position:0% +minimum among among all all such things + + + align:start position:0% +minimum among among all all such things +and you did this for bipartite graphs. + + align:start position:0% +and you did this for bipartite graphs. + + + align:start position:0% +and you did this for bipartite graphs. +It's fine with flow networks. You can so + + align:start position:0% +It's fine with flow networks. You can so + + + align:start position:0% +It's fine with flow networks. You can so +I'm not going to go into the algorithm + + align:start position:0% +I'm not going to go into the algorithm + + + align:start position:0% +I'm not going to go into the algorithm +for this. It's kind of complicated but + + align:start position:0% +for this. It's kind of complicated but + + + align:start position:0% +for this. It's kind of complicated but +it uses linear programming and you can + + align:start position:0% +it uses linear programming and you can + + + align:start position:0% +it uses linear programming and you can +find this for complete graph and it's + + align:start position:0% +find this for complete graph and it's + + + align:start position:0% +find this for complete graph and it's +polinomial. That's good. So given a + + align:start position:0% +polinomial. That's good. So given a + + + align:start position:0% +polinomial. That's good. So given a +complete graph you can find the perfect + + align:start position:0% +complete graph you can find the perfect + + + align:start position:0% +complete graph you can find the perfect +matching is what you should assume for + + align:start position:0% +matching is what you should assume for + + + align:start position:0% +matching is what you should assume for +now. Okay. One last thing we want to + + align:start position:0% +now. Okay. One last thing we want to + + + align:start position:0% +now. Okay. One last thing we want to +introduce + + align:start position:0% +introduce + + + align:start position:0% +introduce +is + + align:start position:0% +is + + + align:start position:0% +is +so that's called it's oiler circuits. So + + align:start position:0% +so that's called it's oiler circuits. So + + + align:start position:0% +so that's called it's oiler circuits. So +who who has heard of oiler circuits + + align:start position:0% +who who has heard of oiler circuits + + + align:start position:0% +who who has heard of oiler circuits +before? + + align:start position:0% + + + + align:start position:0% + +Okay. So, + + align:start position:0% + + + + align:start position:0% + +so the reason we're So, okay, let's go + + align:start position:0% +so the reason we're So, okay, let's go + + + align:start position:0% +so the reason we're So, okay, let's go +back to the what we did before. We had a + + align:start position:0% +back to the what we did before. We had a + + + align:start position:0% +back to the what we did before. We had a +tree and we were the best way found to + + align:start position:0% +tree and we were the best way found to + + + align:start position:0% +tree and we were the best way found to +traverse it was just going down and + + align:start position:0% +traverse it was just going down and + + + align:start position:0% +traverse it was just going down and +going back up and going down and sort of + + align:start position:0% +going back up and going down and sort of + + + align:start position:0% +going back up and going down and sort of +messy. So, what we would rather want to + + align:start position:0% +messy. So, what we would rather want to + + + align:start position:0% +messy. So, what we would rather want to +do is sort of traverse the thing without + + align:start position:0% +do is sort of traverse the thing without + + + align:start position:0% +do is sort of traverse the thing without +repeating edges. So I don't know if + + align:start position:0% +repeating edges. So I don't know if + + + align:start position:0% +repeating edges. So I don't know if +you've probably seen this puzzle before. + + align:start position:0% +you've probably seen this puzzle before. + + + align:start position:0% +you've probably seen this puzzle before. +So you you have you have this graph + + align:start position:0% +So you you have you have this graph + + + align:start position:0% +So you you have you have this graph +given to you and the task is to draw + + align:start position:0% +given to you and the task is to draw + + + align:start position:0% +given to you and the task is to draw +this graph without lifting your pen off + + align:start position:0% +this graph without lifting your pen off + + + align:start position:0% +this graph without lifting your pen off +the paper. So for for example in this + + align:start position:0% +the paper. So for for example in this + + + align:start position:0% +the paper. So for for example in this +graph you could start here go here go + + align:start position:0% +graph you could start here go here go + + + align:start position:0% +graph you could start here go here go +here and come back and something and + + align:start position:0% +here and come back and something and + + + align:start position:0% +here and come back and something and +there you go. So you can do that then if + + align:start position:0% +there you go. So you can do that then if + + + align:start position:0% +there you go. So you can do that then if +you but if you add on like another thing + + align:start position:0% +you but if you add on like another thing + + + align:start position:0% +you but if you add on like another thing +another lobe here then you can't make a + + align:start position:0% +another lobe here then you can't make a + + + align:start position:0% +another lobe here then you can't make a +circuit. You can still make a path I + + align:start position:0% +circuit. You can still make a path I + + + align:start position:0% +circuit. You can still make a path I +believe if you add another one you can't + + align:start position:0% +believe if you add another one you can't + + + align:start position:0% +believe if you add another one you can't +even make a path. So how does this work? + + align:start position:0% +even make a path. So how does this work? + + + align:start position:0% +even make a path. So how does this work? +Let's see. So um + + align:start position:0% +Let's see. So um + + + align:start position:0% +Let's see. So um +let's say forget about the graph for + + align:start position:0% +let's say forget about the graph for + + + align:start position:0% +let's say forget about the graph for +now. Let's say you're just drawing. So + + align:start position:0% +now. Let's say you're just drawing. So + + + align:start position:0% +now. Let's say you're just drawing. So +you start somewhere. You go to a vertex. + + align:start position:0% +you start somewhere. You go to a vertex. + + + align:start position:0% +you start somewhere. You go to a vertex. +Go to another vertex. Come back. Go to + + align:start position:0% +Go to another vertex. Come back. Go to + + + align:start position:0% +Go to another vertex. Come back. Go to +this vertex. Leave it. come back. And so + + align:start position:0% +this vertex. Leave it. come back. And so + + + align:start position:0% +this vertex. Leave it. come back. And so +observe that whenever you're making this + + align:start position:0% +observe that whenever you're making this + + + align:start position:0% +observe that whenever you're making this +drawing, you go to a vertex and you + + align:start position:0% +drawing, you go to a vertex and you + + + align:start position:0% +drawing, you go to a vertex and you +leave it. Every time you hit a vertex, + + align:start position:0% +leave it. Every time you hit a vertex, + + + align:start position:0% +leave it. Every time you hit a vertex, +you leave it. Since this is a circuit, + + align:start position:0% +you leave it. Since this is a circuit, + + + align:start position:0% +you leave it. Since this is a circuit, +you just loop around and every time you + + align:start position:0% +you just loop around and every time you + + + align:start position:0% +you just loop around and every time you +enter a vertex, you have to leave it. + + align:start position:0% +enter a vertex, you have to leave it. + + + align:start position:0% +enter a vertex, you have to leave it. +What that means is that even though this + + align:start position:0% +What that means is that even though this + + + align:start position:0% +What that means is that even though this +is not directed, if you like drew out + + align:start position:0% +is not directed, if you like drew out + + + align:start position:0% +is not directed, if you like drew out +the actual path, you would see the + + align:start position:0% +the actual path, you would see the + + + align:start position:0% +the actual path, you would see the +number of vertices go number of edges + + align:start position:0% +number of vertices go number of edges + + + align:start position:0% +number of vertices go number of edges +going into a vertex is equal number of + + align:start position:0% +going into a vertex is equal number of + + + align:start position:0% +going into a vertex is equal number of +ones leaving. Which means that every + + align:start position:0% +ones leaving. Which means that every + + + align:start position:0% +ones leaving. Which means that every +degree has to be even. + + align:start position:0% +degree has to be even. + + + align:start position:0% +degree has to be even. +So if you go and look at this graph + + align:start position:0% +So if you go and look at this graph + + + align:start position:0% +So if you go and look at this graph +which is with added loes, this degree is + + align:start position:0% +which is with added loes, this degree is + + + align:start position:0% +which is with added loes, this degree is +not even. Neither is this, neither is + + align:start position:0% +not even. Neither is this, neither is + + + align:start position:0% +not even. Neither is this, neither is +this, neither is this. They're all five, + + align:start position:0% +this, neither is this. They're all five, + + + align:start position:0% +this, neither is this. They're all five, +I think. Yeah, they're all five. Which + + align:start position:0% +I think. Yeah, they're all five. Which + + + align:start position:0% +I think. Yeah, they're all five. Which +means that this this can never have + + align:start position:0% +means that this this can never have + + + align:start position:0% +means that this this can never have +oiler circuit. So a graph can only have + + align:start position:0% +oiler circuit. So a graph can only have + + + align:start position:0% +oiler circuit. So a graph can only have +an oiler circuit if it has even degrees + + align:start position:0% +an oiler circuit if it has even degrees + + + align:start position:0% +an oiler circuit if it has even degrees +for every vertex. + + align:start position:0% +for every vertex. + + + align:start position:0% +for every vertex. +And the other way is also true. If a + + align:start position:0% +And the other way is also true. If a + + + align:start position:0% +And the other way is also true. If a +graph has even degrees on every vertex, + + align:start position:0% +graph has even degrees on every vertex, + + + align:start position:0% +graph has even degrees on every vertex, +then it must have an oiler circuit. + + align:start position:0% +then it must have an oiler circuit. + + + align:start position:0% +then it must have an oiler circuit. +That's not harder to prove, but like + + align:start position:0% +That's not harder to prove, but like + + + align:start position:0% +That's not harder to prove, but like +there's a constructive algorithm you can + + align:start position:0% +there's a constructive algorithm you can + + + align:start position:0% +there's a constructive algorithm you can +use. So let's say you're given this + + align:start position:0% +use. So let's say you're given this + + + align:start position:0% +use. So let's say you're given this +graph for instance. You would just you + + align:start position:0% +graph for instance. You would just you + + + align:start position:0% +graph for instance. You would just you +would simply go through the graph just + + align:start position:0% +would simply go through the graph just + + + align:start position:0% +would simply go through the graph just +like start at some random node and then + + align:start position:0% +like start at some random node and then + + + align:start position:0% +like start at some random node and then +like go through can keep following edges + + align:start position:0% +like go through can keep following edges + + + align:start position:0% +like go through can keep following edges +till you can no longer follow edges. So + + align:start position:0% +till you can no longer follow edges. So + + + align:start position:0% +till you can no longer follow edges. So +let's say you stop here then you pick + + align:start position:0% +let's say you stop here then you pick + + + align:start position:0% +let's say you stop here then you pick +another edge and start and so on and + + align:start position:0% +another edge and start and so on and + + + align:start position:0% +another edge and start and so on and +then you can like splice these cycles + + align:start position:0% +then you can like splice these cycles + + + align:start position:0% +then you can like splice these cycles +together at some point. So it's kind of + + align:start position:0% +together at some point. So it's kind of + + + align:start position:0% +together at some point. So it's kind of +a hand wavy argument but it should be + + align:start position:0% +a hand wavy argument but it should be + + + align:start position:0% +a hand wavy argument but it should be +sort of intuitive why you can construct + + align:start position:0% +sort of intuitive why you can construct + + + align:start position:0% +sort of intuitive why you can construct +another path given an even degree. + + align:start position:0% +another path given an even degree. + + + align:start position:0% +another path given an even degree. +You just perform searches. You just + + align:start position:0% +You just perform searches. You just + + + align:start position:0% +You just perform searches. You just +create cycles and you splice them + + align:start position:0% +create cycles and you splice them + + + align:start position:0% +create cycles and you splice them +together. But for now, I just take it as + + align:start position:0% +together. But for now, I just take it as + + + align:start position:0% +together. But for now, I just take it as +fact that give a graph as an oiler + + align:start position:0% +fact that give a graph as an oiler + + + align:start position:0% +fact that give a graph as an oiler +circuit as in you can draw it without + + align:start position:0% +circuit as in you can draw it without + + + align:start position:0% +circuit as in you can draw it without +lifting your pen off if and only if + + align:start position:0% +lifting your pen off if and only if + + + align:start position:0% +lifting your pen off if and only if +every vertex has even degree. So why is + + align:start position:0% +every vertex has even degree. So why is + + + align:start position:0% +every vertex has even degree. So why is +that interesting? So let's say we could + + align:start position:0% +that interesting? So let's say we could + + + align:start position:0% +that interesting? So let's say we could +add some edges to our tree and turn it + + align:start position:0% +add some edges to our tree and turn it + + + align:start position:0% +add some edges to our tree and turn it +into turn it into one of those nice + + align:start position:0% +into turn it into one of those nice + + + align:start position:0% +into turn it into one of those nice +graphs. Right? Now this is not right. + + align:start position:0% +graphs. Right? Now this is not right. + + + align:start position:0% +graphs. Right? Now this is not right. +This is vertic degree 1 degree 1 degree + + align:start position:0% +This is vertic degree 1 degree 1 degree + + + align:start position:0% +This is vertic degree 1 degree 1 degree +3 degree 1 degree 1 degree three. All of + + align:start position:0% +3 degree 1 degree 1 degree three. All of + + + align:start position:0% +3 degree 1 degree 1 degree three. All of +them are odd but that's not good. But + + align:start position:0% +them are odd but that's not good. But + + + align:start position:0% +them are odd but that's not good. But +let's say you could add some edges in, + + align:start position:0% +let's say you could add some edges in, + + + align:start position:0% +let's say you could add some edges in, +turn it to an oiler circuit and then you + + align:start position:0% +turn it to an oiler circuit and then you + + + align:start position:0% +turn it to an oiler circuit and then you +could do a nice reversal of it and maybe + + align:start position:0% +could do a nice reversal of it and maybe + + + align:start position:0% +could do a nice reversal of it and maybe +that'll give you a better approximation. + + align:start position:0% +that'll give you a better approximation. + + + align:start position:0% +that'll give you a better approximation. +So with that hope, let's look at the + + align:start position:0% +So with that hope, let's look at the + + + align:start position:0% +So with that hope, let's look at the +algorithm. + + align:start position:0% +algorithm. + + + align:start position:0% +algorithm. +So what you do is you go back to your + + align:start position:0% +So what you do is you go back to your + + + align:start position:0% +So what you do is you go back to your +tree. + + align:start position:0% + + + + align:start position:0% + +Let's just leave it at that. So + + align:start position:0% +Let's just leave it at that. So + + + align:start position:0% +Let's just leave it at that. So +now let's see. So this is degree two. + + align:start position:0% +now let's see. So this is degree two. + + + align:start position:0% +now let's see. So this is degree two. +That's good. This is degree three. + + align:start position:0% +That's good. This is degree three. + + + align:start position:0% +That's good. This is degree three. +That's not good. Degree one. This is + + align:start position:0% +That's not good. Degree one. This is + + + align:start position:0% +That's not good. Degree one. This is +fine. This is degree one. This also has + + align:start position:0% +fine. This is degree one. This also has + + + align:start position:0% +fine. This is degree one. This also has +degree one. This is degree three. + + align:start position:0% +degree one. This is degree three. + + + align:start position:0% +degree one. This is degree three. +Actually, let's let's get rid of this. + + align:start position:0% +Actually, let's let's get rid of this. + + + align:start position:0% +Actually, let's let's get rid of this. +It does not have degree three. That's a + + align:start position:0% +It does not have degree three. That's a + + + align:start position:0% +It does not have degree three. That's a +lot of vertices. Okay, there we go. + + align:start position:0% +lot of vertices. Okay, there we go. + + + align:start position:0% +lot of vertices. Okay, there we go. +So in this graph, you see that you have + + align:start position:0% +So in this graph, you see that you have + + + align:start position:0% +So in this graph, you see that you have +1 2 3 4 five vertices which have degree + + align:start position:0% +1 2 3 4 five vertices which have degree + + + align:start position:0% +1 2 3 4 five vertices which have degree +odd. So now we would like to add some + + align:start position:0% +odd. So now we would like to add some + + + align:start position:0% +odd. So now we would like to add some +edges to make to turn this set of turn + + align:start position:0% +edges to make to turn this set of turn + + + align:start position:0% +edges to make to turn this set of turn +this into another circuitable graph. So + + align:start position:0% +this into another circuitable graph. So + + + align:start position:0% +this into another circuitable graph. So +how do we do that? So let's call the set + + align:start position:0% +how do we do that? So let's call the set + + + align:start position:0% +how do we do that? So let's call the set +of odd edges S. + + align:start position:0% + + + + align:start position:0% + +It's odd vertices. Sorry. + + align:start position:0% + + + + align:start position:0% + +So you take the set of odd degree + + align:start position:0% +So you take the set of odd degree + + + align:start position:0% +So you take the set of odd degree +vertices. Now + + align:start position:0% +vertices. Now + + + align:start position:0% +vertices. Now +go back to perfect matchings. So what + + align:start position:0% +go back to perfect matchings. So what + + + align:start position:0% +go back to perfect matchings. So what +does a perfect matching do? It adds + + align:start position:0% +does a perfect matching do? It adds + + + align:start position:0% +does a perfect matching do? It adds +edges to that graph so that everything + + align:start position:0% +edges to that graph so that everything + + + align:start position:0% +edges to that graph so that everything +gets degree increased by one. + + align:start position:0% +gets degree increased by one. + + + align:start position:0% +gets degree increased by one. +So if you increase the degree of all the + + align:start position:0% +So if you increase the degree of all the + + + align:start position:0% +So if you increase the degree of all the +odd vertices by one, everything turns + + align:start position:0% +odd vertices by one, everything turns + + + align:start position:0% +odd vertices by one, everything turns +even. Right? + + align:start position:0% +even. Right? + + + align:start position:0% +even. Right? +So you take the set of odd vertices. + + align:start position:0% +So you take the set of odd vertices. + + + align:start position:0% +So you take the set of odd vertices. +Okay. Another thing to observe, realize + + align:start position:0% +Okay. Another thing to observe, realize + + + align:start position:0% +Okay. Another thing to observe, realize +that how many odd verses can you have? + + align:start position:0% +that how many odd verses can you have? + + + align:start position:0% +that how many odd verses can you have? +Can you have an odd number of odd + + align:start position:0% +Can you have an odd number of odd + + + align:start position:0% +Can you have an odd number of odd +vertices? Because that would that would + + align:start position:0% +vertices? Because that would that would + + + align:start position:0% +vertices? Because that would that would +that would screw up the whole thing + + align:start position:0% +that would screw up the whole thing + + + align:start position:0% +that would screw up the whole thing +where we needed an even number of + + align:start position:0% +where we needed an even number of + + + align:start position:0% +where we needed an even number of +things. + + align:start position:0% + + + + align:start position:0% + +So, so why why could can you why why is + + align:start position:0% +So, so why why could can you why why is + + + align:start position:0% +So, so why why could can you why why is +that not possible? Why can you not have + + align:start position:0% +that not possible? Why can you not have + + + align:start position:0% +that not possible? Why can you not have +an odd number of odd vertices? + + align:start position:0% + + + + align:start position:0% + +So, the thing is that + + align:start position:0% +So, the thing is that + + + align:start position:0% +So, the thing is that +let's say let's say you have some graph + + align:start position:0% +let's say let's say you have some graph + + + align:start position:0% +let's say let's say you have some graph +and what is the sum of the degrees of + + align:start position:0% +and what is the sum of the degrees of + + + align:start position:0% +and what is the sum of the degrees of +the graph? Let's move to a different + + align:start position:0% +the graph? Let's move to a different + + + align:start position:0% +the graph? Let's move to a different +board for this. + + align:start position:0% + + + + align:start position:0% + +So you have a graph G and you want the + + align:start position:0% +So you have a graph G and you want the + + + align:start position:0% +So you have a graph G and you want the +sum of degrees. So DI is the degree for + + align:start position:0% +sum of degrees. So DI is the degree for + + + align:start position:0% +sum of degrees. So DI is the degree for +all V. So what is this equal to? So + + align:start position:0% +all V. So what is this equal to? So + + + align:start position:0% +all V. So what is this equal to? So +let's say you have this graph. + + align:start position:0% + + + + align:start position:0% + +So now if you count the degrees of every + + align:start position:0% +So now if you count the degrees of every + + + align:start position:0% +So now if you count the degrees of every +vertex, + + align:start position:0% +vertex, + + + align:start position:0% +vertex, +you're basically counting the number of + + align:start position:0% +you're basically counting the number of + + + align:start position:0% +you're basically counting the number of +edges coming out, which means that every + + align:start position:0% +edges coming out, which means that every + + + align:start position:0% +edges coming out, which means that every +edge is counted twice. Once for its this + + align:start position:0% +edge is counted twice. Once for its this + + + align:start position:0% +edge is counted twice. Once for its this +end point, once for this end point. This + + align:start position:0% +end point, once for this end point. This + + + align:start position:0% +end point, once for this end point. This +edge is counted twice for here and here. + + align:start position:0% +edge is counted twice for here and here. + + + align:start position:0% +edge is counted twice for here and here. +This edge is also counted twice. So + + align:start position:0% +This edge is also counted twice. So + + + align:start position:0% +This edge is also counted twice. So +basically the sum of the degrees is + + align:start position:0% +basically the sum of the degrees is + + + align:start position:0% +basically the sum of the degrees is +nothing but 2 * mod of e. Does that make + + align:start position:0% +nothing but 2 * mod of e. Does that make + + + align:start position:0% +nothing but 2 * mod of e. Does that make +sense? Right? + + align:start position:0% +sense? Right? + + + align:start position:0% +sense? Right? +So this is even. Now let's say you take + + align:start position:0% +So this is even. Now let's say you take + + + align:start position:0% +So this is even. Now let's say you take +only the odd vertices out. So you the + + align:start position:0% +only the odd vertices out. So you the + + + align:start position:0% +only the odd vertices out. So you the +even vertices are good. This is good. + + align:start position:0% +even vertices are good. This is good. + + + align:start position:0% +even vertices are good. This is good. +This is good. This is not good. This is + + align:start position:0% +This is good. This is not good. This is + + + align:start position:0% +This is good. This is not good. This is +also not good. This is Yeah. So these + + align:start position:0% +also not good. This is Yeah. So these + + + align:start position:0% +also not good. This is Yeah. So these +are the odd vertices. + + align:start position:0% +are the odd vertices. + + + align:start position:0% +are the odd vertices. +So the sum of the degrees of the even + + align:start position:0% +So the sum of the degrees of the even + + + align:start position:0% +So the sum of the degrees of the even +vertices are by definition even even. So + + align:start position:0% +vertices are by definition even even. So + + + align:start position:0% +vertices are by definition even even. So +if you remove them the sum of the odd + + align:start position:0% +if you remove them the sum of the odd + + + align:start position:0% +if you remove them the sum of the odd +vertices should also remain even. + + align:start position:0% +vertices should also remain even. + + + align:start position:0% +vertices should also remain even. +And so you have the sum of odd degrees + + align:start position:0% +And so you have the sum of odd degrees + + + align:start position:0% +And so you have the sum of odd degrees +becoming even which means that you need + + align:start position:0% +becoming even which means that you need + + + align:start position:0% +becoming even which means that you need +to have an even number of them. Make + + align:start position:0% +to have an even number of them. Make + + + align:start position:0% +to have an even number of them. Make +sense? + + align:start position:0% +sense? + + + align:start position:0% +sense? +So + + align:start position:0% +So + + + align:start position:0% +So +going back to this, so there's a lot of + + align:start position:0% +going back to this, so there's a lot of + + + align:start position:0% +going back to this, so there's a lot of +lot of branching off here, but going + + align:start position:0% +lot of branching off here, but going + + + align:start position:0% +lot of branching off here, but going +back to the main point here is that you + + align:start position:0% +back to the main point here is that you + + + align:start position:0% +back to the main point here is that you +have an even number of odd vertices. So + + align:start position:0% +have an even number of odd vertices. So + + + align:start position:0% +have an even number of odd vertices. So +consider the restriction of the original + + align:start position:0% +consider the restriction of the original + + + align:start position:0% +consider the restriction of the original +graph G to this set S. So now we're + + align:start position:0% +graph G to this set S. So now we're + + + align:start position:0% +graph G to this set S. So now we're +going to the first thing we did there + + align:start position:0% +going to the first thing we did there + + + align:start position:0% +going to the first thing we did there +where we considered a restriction of the + + align:start position:0% +where we considered a restriction of the + + + align:start position:0% +where we considered a restriction of the +graph to a certain set of vertices. So + + align:start position:0% +graph to a certain set of vertices. So + + + align:start position:0% +graph to a certain set of vertices. So +you take the set. So 1 2 3 4 5. So you + + align:start position:0% +you take the set. So 1 2 3 4 5. So you + + + align:start position:0% +you take the set. So 1 2 3 4 5. So you +take these five vertices + + align:start position:0% + + + + align:start position:0% + +and you consider the graph that is + + align:start position:0% +and you consider the graph that is + + + align:start position:0% +and you consider the graph that is +restricted to these five vertices. Oh + + align:start position:0% +restricted to these five vertices. Oh + + + align:start position:0% +restricted to these five vertices. Oh +sorry there should be six. + + align:start position:0% +sorry there should be six. + + + align:start position:0% +sorry there should be six. +Oh there's there we go. That's the other + + align:start position:0% +Oh there's there we go. That's the other + + + align:start position:0% +Oh there's there we go. That's the other +one. + + align:start position:0% + + + + align:start position:0% + +So those are your six vertices which + + align:start position:0% +So those are your six vertices which + + + align:start position:0% +So those are your six vertices which +have odd degrees. Now you find a perfect + + align:start position:0% +have odd degrees. Now you find a perfect + + + align:start position:0% +have odd degrees. Now you find a perfect +matching with your polinomal sign + + align:start position:0% +matching with your polinomal sign + + + align:start position:0% +matching with your polinomal sign +algorithm + + align:start position:0% +algorithm + + + align:start position:0% +algorithm +and you get something. So you can now + + align:start position:0% +and you get something. So you can now + + + align:start position:0% +and you get something. So you can now +add those edges back in here. So these + + align:start position:0% +add those edges back in here. So these + + + align:start position:0% +add those edges back in here. So these +are your new edges and let's say + + align:start position:0% +are your new edges and let's say + + + align:start position:0% +are your new edges and let's say +and something + + align:start position:0% +and something + + + align:start position:0% +and something +this one. Okay. So you get three new + + align:start position:0% +this one. Okay. So you get three new + + + align:start position:0% +this one. Okay. So you get three new +edges and now realize that all the + + align:start position:0% +edges and now realize that all the + + + align:start position:0% +edges and now realize that all the +degrees are now even. So now you can do + + align:start position:0% +degrees are now even. So now you can do + + + align:start position:0% +degrees are now even. So now you can do +your circuit also. So let's call this + + align:start position:0% +your circuit also. So let's call this + + + align:start position:0% +your circuit also. So let's call this +matching M. So this is a set of edges M. + + align:start position:0% +matching M. So this is a set of edges M. + + + align:start position:0% +matching M. So this is a set of edges M. +Let's call the original tree T and the + + align:start position:0% +Let's call the original tree T and the + + + align:start position:0% +Let's call the original tree T and the +new thing that is formed is T union M. + + align:start position:0% +new thing that is formed is T union M. + + + align:start position:0% +new thing that is formed is T union M. +So you're taking all the edges from T + + align:start position:0% +So you're taking all the edges from T + + + align:start position:0% +So you're taking all the edges from T +and you're adding all the edges from M. + + align:start position:0% +and you're adding all the edges from M. + + + align:start position:0% +and you're adding all the edges from M. +So realize that you can have multiple + + align:start position:0% +So realize that you can have multiple + + + align:start position:0% +So realize that you can have multiple +edges, but that's fine because oiler + + align:start position:0% +edges, but that's fine because oiler + + + align:start position:0% +edges, but that's fine because oiler +circuits allow you to have multiple + + align:start position:0% +circuits allow you to have multiple + + + align:start position:0% +circuits allow you to have multiple +edges. So now you take this graph and + + align:start position:0% +edges. So now you take this graph and + + + align:start position:0% +edges. So now you take this graph and +you find this oiler circuit. + + align:start position:0% +you find this oiler circuit. + + + align:start position:0% +you find this oiler circuit. +So that is basically this thing. So the + + align:start position:0% +So that is basically this thing. So the + + + align:start position:0% +So that is basically this thing. So the +set of edges in some order and that + + align:start position:0% +set of edges in some order and that + + + align:start position:0% +set of edges in some order and that +order exists. So the cost of the oiler + + align:start position:0% +order exists. So the cost of the oiler + + + align:start position:0% +order exists. So the cost of the oiler +circuit let's call it C is equal to the + + align:start position:0% +circuit let's call it C is equal to the + + + align:start position:0% +circuit let's call it C is equal to the +cost of T plus the cost of M right + + align:start position:0% +cost of T plus the cost of M right + + + align:start position:0% +cost of T plus the cost of M right +because you're traversing all the edges + + align:start position:0% +because you're traversing all the edges + + + align:start position:0% +because you're traversing all the edges +in your graph. So that is the cost + + align:start position:0% +in your graph. So that is the cost + + + align:start position:0% +in your graph. So that is the cost +circuit. Now my claim is that so this + + align:start position:0% +circuit. Now my claim is that so this + + + align:start position:0% +circuit. Now my claim is that so this +this is visiting all the nodes in the + + align:start position:0% +this is visiting all the nodes in the + + + align:start position:0% +this is visiting all the nodes in the +graph and remember you can do the whole + + align:start position:0% +graph and remember you can do the whole + + + align:start position:0% +graph and remember you can do the whole +dup duplication argument from before + + align:start position:0% +dup duplication argument from before + + + align:start position:0% +dup duplication argument from before +where so where was that ah there so you + + align:start position:0% +where so where was that ah there so you + + + align:start position:0% +where so where was that ah there so you +can do the duplication argument so + + align:start position:0% +can do the duplication argument so + + + align:start position:0% +can do the duplication argument so +you're visiting all the edges in the + + align:start position:0% +you're visiting all the edges in the + + + align:start position:0% +you're visiting all the edges in the +graph all the vertices in the graph you + + align:start position:0% +graph all the vertices in the graph you + + + align:start position:0% +graph all the vertices in the graph you +remove the duplicates and you have a + + align:start position:0% +remove the duplicates and you have a + + + align:start position:0% +remove the duplicates and you have a +valid path now let's see if this valid + + align:start position:0% +valid path now let's see if this valid + + + align:start position:0% +valid path now let's see if this valid +path is actually + + align:start position:0% +path is actually + + + align:start position:0% +path is actually +uh a better approximation + + align:start position:0% +uh a better approximation + + + align:start position:0% +uh a better approximation +So, + + align:start position:0% + + + + align:start position:0% + +so again you will go from C. So this C + + align:start position:0% +so again you will go from C. So this C + + + align:start position:0% +so again you will go from C. So this C +will go to C dash + + align:start position:0% + + + + align:start position:0% + +and this will give you as before uh cost + + align:start position:0% +and this will give you as before uh cost + + + align:start position:0% +and this will give you as before uh cost +of C dash is less than equal to cost of + + align:start position:0% +of C dash is less than equal to cost of + + + align:start position:0% +of C dash is less than equal to cost of +C. So now you're only interested in cost + + align:start position:0% +C. So now you're only interested in cost + + + align:start position:0% +C. So now you're only interested in cost +of C. So what are we doing there? So we + + align:start position:0% +of C. So what are we doing there? So we + + + align:start position:0% +of C. So what are we doing there? So we +know that the cost of + + align:start position:0% +know that the cost of + + + align:start position:0% +know that the cost of +C is equal to cost of T plus the cost of + + align:start position:0% +C is equal to cost of T plus the cost of + + + align:start position:0% +C is equal to cost of T plus the cost of +M. + + align:start position:0% +M. + + + align:start position:0% +M. +So from the previous problem we know + + align:start position:0% +So from the previous problem we know + + + align:start position:0% +So from the previous problem we know +that the cost of t is less than equal to + + align:start position:0% +that the cost of t is less than equal to + + + align:start position:0% +that the cost of t is less than equal to +the cost of h star of g right. So this + + align:start position:0% +the cost of h star of g right. So this + + + align:start position:0% +the cost of h star of g right. So this +is less than equal to cost of + + align:start position:0% +is less than equal to cost of + + + align:start position:0% +is less than equal to cost of +h star g. + + align:start position:0% +h star g. + + + align:start position:0% +h star g. +So this guy is less than the optimal + + align:start position:0% +So this guy is less than the optimal + + + align:start position:0% +So this guy is less than the optimal +hamiltonian path. What about this guy? + + align:start position:0% +hamiltonian path. What about this guy? + + + align:start position:0% +hamiltonian path. What about this guy? +Well, so let's take let's look at the + + align:start position:0% +Well, so let's take let's look at the + + + align:start position:0% +Well, so let's take let's look at the +actual H star G again. + + align:start position:0% + + + + align:start position:0% + +So actually let's look at H star S. + + align:start position:0% +So actually let's look at H star S. + + + align:start position:0% +So actually let's look at H star S. +So S remember that S is the set of odd + + align:start position:0% +So S remember that S is the set of odd + + + align:start position:0% +So S remember that S is the set of odd +vertices and that is where this matching + + align:start position:0% +vertices and that is where this matching + + + align:start position:0% +vertices and that is where this matching +is done. So H star S is nothing but the + + align:start position:0% +is done. So H star S is nothing but the + + + align:start position:0% +is done. So H star S is nothing but the +optimal Hamiltonian cycle on that + + align:start position:0% +optimal Hamiltonian cycle on that + + + align:start position:0% +optimal Hamiltonian cycle on that +restricted graph. Okay, from our + + align:start position:0% +restricted graph. Okay, from our + + + align:start position:0% +restricted graph. Okay, from our +previous lema which I which is down + + align:start position:0% +previous lema which I which is down + + + align:start position:0% +previous lema which I which is down +here, we know that H star of S is less + + align:start position:0% +here, we know that H star of S is less + + + align:start position:0% +here, we know that H star of S is less +than H star of G. + + align:start position:0% +than H star of G. + + + align:start position:0% +than H star of G. +So + + align:start position:0% +So + + + align:start position:0% +So +we know that cost of + + align:start position:0% +we know that cost of + + + align:start position:0% +we know that cost of +is less than equal to cost of whatever + + align:start position:0% +is less than equal to cost of whatever + + + align:start position:0% +is less than equal to cost of whatever +G. + + align:start position:0% +G. + + + align:start position:0% +G. +So now let's look at just look at HR. + + align:start position:0% +So now let's look at just look at HR. + + + align:start position:0% +So now let's look at just look at HR. +Now we construct a matching. + + align:start position:0% +Now we construct a matching. + + + align:start position:0% +Now we construct a matching. +We take every other edge. You take this + + align:start position:0% +We take every other edge. You take this + + + align:start position:0% +We take every other edge. You take this +one, you would take this one, you take + + align:start position:0% +one, you would take this one, you take + + + align:start position:0% +one, you would take this one, you take +this one and + + align:start position:0% +this one and + + + align:start position:0% +this one and +and look at the alternate set also. So + + align:start position:0% +and look at the alternate set also. So + + + align:start position:0% +and look at the alternate set also. So +take this one and this one and this one. + + align:start position:0% +take this one and this one and this one. + + + align:start position:0% +take this one and this one and this one. +So look at the blue set and the red set. + + align:start position:0% +So look at the blue set and the red set. + + + align:start position:0% +So look at the blue set and the red set. +Since it's part of a Hamiltonian cycle, + + align:start position:0% +Since it's part of a Hamiltonian cycle, + + + align:start position:0% +Since it's part of a Hamiltonian cycle, +they're both matchings, right? + + align:start position:0% +they're both matchings, right? + + + align:start position:0% +they're both matchings, right? +So let's call the red one M1 and the + + align:start position:0% +So let's call the red one M1 and the + + + align:start position:0% +So let's call the red one M1 and the +blue one M2. + + align:start position:0% +blue one M2. + + + align:start position:0% +blue one M2. +So I'm not saying they're perfect + + align:start position:0% +So I'm not saying they're perfect + + + align:start position:0% +So I'm not saying they're perfect +matchings. They're they're not the min + + align:start position:0% +matchings. They're they're not the min + + + align:start position:0% +matchings. They're they're not the min +minimum matchings, but they're + + align:start position:0% +minimum matchings, but they're + + + align:start position:0% +minimum matchings, but they're +definitely perfect matchings. And + + align:start position:0% +definitely perfect matchings. And + + + align:start position:0% +definitely perfect matchings. And +because they're because we know the + + align:start position:0% +because they're because we know the + + + align:start position:0% +because they're because we know the +perfect matching is M + + align:start position:0% +perfect matching is M + + + align:start position:0% +perfect matching is M +or the minimum matching is M. Cost of M + + align:start position:0% +or the minimum matching is M. Cost of M + + + align:start position:0% +or the minimum matching is M. Cost of M +is less than equal to + + align:start position:0% +is less than equal to + + + align:start position:0% +is less than equal to +cost of M1. + + align:start position:0% +cost of M1. + + + align:start position:0% +cost of M1. +And also the cost of M is less than + + align:start position:0% +And also the cost of M is less than + + + align:start position:0% +And also the cost of M is less than +equal to the cost of + + align:start position:0% +equal to the cost of + + + align:start position:0% +equal to the cost of +M2. + + align:start position:0% +M2. + + + align:start position:0% +M2. +Make sense? Because M was the minimum + + align:start position:0% +Make sense? Because M was the minimum + + + align:start position:0% +Make sense? Because M was the minimum +cost matching. you have cost of M is + + align:start position:0% +cost matching. you have cost of M is + + + align:start position:0% +cost matching. you have cost of M is +less than any other matching which is + + align:start position:0% +less than any other matching which is + + + align:start position:0% +less than any other matching which is +constructed from this again. So this + + align:start position:0% +constructed from this again. So this + + + align:start position:0% +constructed from this again. So this +implies that the cost of M + + align:start position:0% +implies that the cost of M + + + align:start position:0% +implies that the cost of M +is + + align:start position:0% +is + + + align:start position:0% +is +less than equal to + + align:start position:0% +less than equal to + + + align:start position:0% +less than equal to +half + + align:start position:0% + + + + align:start position:0% + +cost of okay let's not let's not write + + align:start position:0% +cost of okay let's not let's not write + + + align:start position:0% +cost of okay let's not let's not write +this here + + align:start position:0% + + + + align:start position:0% + +let's get a different board + + align:start position:0% + + + + align:start position:0% + +this here so cost of H that's less than + + align:start position:0% +this here so cost of H that's less than + + + align:start position:0% +this here so cost of H that's less than +equal to half + + align:start position:0% +equal to half + + + align:start position:0% +equal to half +cost of M1 + + align:start position:0% +cost of M1 + + + align:start position:0% +cost of M1 +plus cost of M2. + + align:start position:0% +plus cost of M2. + + + align:start position:0% +plus cost of M2. +Since both of these guys are larger than + + align:start position:0% +Since both of these guys are larger than + + + align:start position:0% +Since both of these guys are larger than +this, their average is also larger than + + align:start position:0% +this, their average is also larger than + + + align:start position:0% +this, their average is also larger than +this. Right? But what is cost of M1 plus + + align:start position:0% +this. Right? But what is cost of M1 plus + + + align:start position:0% +this. Right? But what is cost of M1 plus +of M2? This is nothing but half + + align:start position:0% +of M2? This is nothing but half + + + align:start position:0% +of M2? This is nothing but half +cost of H star of S. Right? Because the + + align:start position:0% +cost of H star of S. Right? Because the + + + align:start position:0% +cost of H star of S. Right? Because the +Hamiltonian cycle is constructed from M1 + + align:start position:0% +Hamiltonian cycle is constructed from M1 + + + align:start position:0% +Hamiltonian cycle is constructed from M1 +and M2. + + align:start position:0% + + + + align:start position:0% + +So and by our lema this is less than + + align:start position:0% +So and by our lema this is less than + + + align:start position:0% +So and by our lema this is less than +equal to half cost of h star of g. + + align:start position:0% +equal to half cost of h star of g. + + + align:start position:0% +equal to half cost of h star of g. +Right? So now we have all we need. This + + align:start position:0% +Right? So now we have all we need. This + + + align:start position:0% +Right? So now we have all we need. This +is less than equal to half cost of + + align:start position:0% +is less than equal to half cost of + + + align:start position:0% +is less than equal to half cost of +h star of g. And then add them together + + align:start position:0% +h star of g. And then add them together + + + align:start position:0% +h star of g. And then add them together +you get cost of C dash is less than + + align:start position:0% +you get cost of C dash is less than + + + align:start position:0% +you get cost of C dash is less than +equal to cost of C is less than equal to + + align:start position:0% +equal to cost of C is less than equal to + + + align:start position:0% +equal to cost of C is less than equal to +the sum which is equal to three cost of + + align:start position:0% +the sum which is equal to three cost of + + + align:start position:0% +the sum which is equal to three cost of +H star of G. + + align:start position:0% + + + + align:start position:0% + +So that's the proof. So there's a lot of + + align:start position:0% +So that's the proof. So there's a lot of + + + align:start position:0% +So that's the proof. So there's a lot of +lot lot of things going on here. Let's + + align:start position:0% +lot lot of things going on here. Let's + + + align:start position:0% +lot lot of things going on here. Let's +try to go back and see what we did. So + + align:start position:0% +try to go back and see what we did. So + + + align:start position:0% +try to go back and see what we did. So +we took a minimum spanning tree and then + + align:start position:0% +we took a minimum spanning tree and then + + + align:start position:0% +we took a minimum spanning tree and then +we tried to remove all the odd odd + + align:start position:0% +we tried to remove all the odd odd + + + align:start position:0% +we tried to remove all the odd odd +degree vertices. So we took all the odd + + align:start position:0% +degree vertices. So we took all the odd + + + align:start position:0% +degree vertices. So we took all the odd +degree vertices and made a perfect + + align:start position:0% +degree vertices and made a perfect + + + align:start position:0% +degree vertices and made a perfect +matching the minimum cost perfect + + align:start position:0% +matching the minimum cost perfect + + + align:start position:0% +matching the minimum cost perfect +matching. So we added edges just to make + + align:start position:0% +matching. So we added edges just to make + + + align:start position:0% +matching. So we added edges just to make +everything even degree. + + align:start position:0% +everything even degree. + + + align:start position:0% +everything even degree. +Then we took the oiler circuit on that + + align:start position:0% +Then we took the oiler circuit on that + + + align:start position:0% +Then we took the oiler circuit on that +graph + + align:start position:0% +graph + + + align:start position:0% +graph +and we removed duplicates. So that's + + align:start position:0% +and we removed duplicates. So that's + + + align:start position:0% +and we removed duplicates. So that's +fine. That's the easy part. But you took + + align:start position:0% +fine. That's the easy part. But you took + + + align:start position:0% +fine. That's the easy part. But you took +the oiler circuit on that graph. And + + align:start position:0% +the oiler circuit on that graph. And + + + align:start position:0% +the oiler circuit on that graph. And +then you argued that because all the + + align:start position:0% +then you argued that because all the + + + align:start position:0% +then you argued that because all the +circuit in that graph is just the sum of + + align:start position:0% +circuit in that graph is just the sum of + + + align:start position:0% +circuit in that graph is just the sum of +the edges in the spanning tree plus the + + align:start position:0% +the edges in the spanning tree plus the + + + align:start position:0% +the edges in the spanning tree plus the +sum of the edges in the matching which + + align:start position:0% +sum of the edges in the matching which + + + align:start position:0% +sum of the edges in the matching which +you added later. So the spanning tree + + align:start position:0% +you added later. So the spanning tree + + + align:start position:0% +you added later. So the spanning tree +had already bounded in the previous + + align:start position:0% +had already bounded in the previous + + + align:start position:0% +had already bounded in the previous +argument. The matching was bounded by + + align:start position:0% +argument. The matching was bounded by + + + align:start position:0% +argument. The matching was bounded by +taking the optimal Hamiltonian cycle + + align:start position:0% +taking the optimal Hamiltonian cycle + + + align:start position:0% +taking the optimal Hamiltonian cycle +decomposing it into two matchings + + align:start position:0% +decomposing it into two matchings + + + align:start position:0% +decomposing it into two matchings +arguing that those two matchings are not + + align:start position:0% +arguing that those two matchings are not + + + align:start position:0% +arguing that those two matchings are not +the optimal matching. So not necessarily + + align:start position:0% +the optimal matching. So not necessarily + + + align:start position:0% +the optimal matching. So not necessarily +the optimal matchings but they're at + + align:start position:0% +the optimal matchings but they're at + + + align:start position:0% +the optimal matchings but they're at +least they're less than equal to the + + align:start position:0% +least they're less than equal to the + + + align:start position:0% +least they're less than equal to the +optimal. So there he went there. And so + + align:start position:0% +optimal. So there he went there. And so + + + align:start position:0% +optimal. So there he went there. And so +the cost of the optimal matching which + + align:start position:0% +the cost of the optimal matching which + + + align:start position:0% +the cost of the optimal matching which +you're using in our constructed path + + align:start position:0% +you're using in our constructed path + + + align:start position:0% +you're using in our constructed path +constructed Hamiltonian cycle is less + + align:start position:0% +constructed Hamiltonian cycle is less + + + align:start position:0% +constructed Hamiltonian cycle is less +than equal to both of these matchings. + + align:start position:0% +than equal to both of these matchings. + + + align:start position:0% +than equal to both of these matchings. +You add them up you get that bound and + + align:start position:0% +You add them up you get that bound and + + + align:start position:0% +You add them up you get that bound and +works. So questions on any of the steps. + + align:start position:0% +works. So questions on any of the steps. + + + align:start position:0% +works. So questions on any of the steps. +This is a lot of branching off and then + + align:start position:0% +This is a lot of branching off and then + + + align:start position:0% +This is a lot of branching off and then +coming back together but yeah + + align:start position:0% +coming back together but yeah + + + align:start position:0% +coming back together but yeah +yes that is not 3x3 that that would be P + + align:start position:0% +yes that is not 3x3 that that would be P + + + align:start position:0% +yes that is not 3x3 that that would be P +equals NP. + + align:start position:0% +equals NP. + + + align:start position:0% +equals NP. +Yeah. Anything else? + + align:start position:0% + + + + align:start position:0% + +Okay, you're free to go or ask questions + + align:start position:0% +Okay, you're free to go or ask questions + + + align:start position:0% +Okay, you're free to go or ask questions +or whatever. + + align:start position:0% + + + + align:start position:0% + +Oh, \ No newline at end of file diff --git a/zPGh2bBeIgM.txt b/zPGh2bBeIgM.txt new file mode 100644 index 0000000000000000000000000000000000000000..c8f6430e5cf156b823fa2771f413ee7f77672e52 --- /dev/null +++ b/zPGh2bBeIgM.txt @@ -0,0 +1,14368 @@ +align:start position:0% + +the following content is provided by mit + + align:start position:0% +the following content is provided by mit + + + align:start position:0% +the following content is provided by mit +opencourseware under a creative commons + + align:start position:0% +opencourseware under a creative commons + + + align:start position:0% +opencourseware under a creative commons +license + + align:start position:0% +license + + + align:start position:0% +license +additional information about our license + + align:start position:0% +additional information about our license + + + align:start position:0% +additional information about our license +and mit opencourseware in general is + + align:start position:0% +and mit opencourseware in general is + + + align:start position:0% +and mit opencourseware in general is +available at ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +okay uh then what we'll do today is + + align:start position:0% +okay uh then what we'll do today is + + + align:start position:0% +okay uh then what we'll do today is +uh + + align:start position:0% +uh + + + align:start position:0% +uh +recapitulation of the semester + + align:start position:0% +recapitulation of the semester + + + align:start position:0% +recapitulation of the semester +forward looking to the rest of the + + align:start position:0% +forward looking to the rest of the + + + align:start position:0% +forward looking to the rest of the +semester + + align:start position:0% +semester + + + align:start position:0% +semester +adjusting the syllabus to + + align:start position:0% +adjusting the syllabus to + + + align:start position:0% +adjusting the syllabus to +uh concerns all concerns + + align:start position:0% +uh concerns all concerns + + + align:start position:0% +uh concerns all concerns +the best we can + + align:start position:0% +the best we can + + + align:start position:0% +the best we can +uh + + align:start position:0% +uh + + + align:start position:0% +uh +and um + + align:start position:0% + + + + align:start position:0% + +that introduction then i want to do an + + align:start position:0% +that introduction then i want to do an + + + align:start position:0% +that introduction then i want to do an +introduction to codes of ethics + + align:start position:0% + + + + align:start position:0% + +and as long as we're not talking too + + align:start position:0% +and as long as we're not talking too + + + align:start position:0% +and as long as we're not talking too +much about hyperspaces + + align:start position:0% +much about hyperspaces + + + align:start position:0% +much about hyperspaces +then i won't get carried off + + align:start position:0% +then i won't get carried off + + + align:start position:0% +then i won't get carried off +we'll be able to talk about + + align:start position:0% + + + + align:start position:0% + +not that i don't want to talk about + + align:start position:0% +not that i don't want to talk about + + + align:start position:0% +not that i don't want to talk about +hyperspaces but then we'll talk about + + align:start position:0% +hyperspaces but then we'll talk about + + + align:start position:0% +hyperspaces but then we'll talk about +codes of ethics + + align:start position:0% +codes of ethics + + + align:start position:0% +codes of ethics +we've all met our visitor today and he + + align:start position:0% +we've all met our visitor today and he + + + align:start position:0% +we've all met our visitor today and he +is welcome to participate in the class + + align:start position:0% +is welcome to participate in the class + + + align:start position:0% +is welcome to participate in the class +uh he's a colleague of tony and mine uh + + align:start position:0% +uh he's a colleague of tony and mine uh + + + align:start position:0% +uh he's a colleague of tony and mine uh +and uh + + align:start position:0% +and uh + + + align:start position:0% +and uh +it's an honor to have you with us but + + align:start position:0% +it's an honor to have you with us but + + + align:start position:0% +it's an honor to have you with us but +phil you you will find + + align:start position:0% +phil you you will find + + + align:start position:0% +phil you you will find +in this class a motivation to say + + align:start position:0% +in this class a motivation to say + + + align:start position:0% +in this class a motivation to say +something i think + + align:start position:0% + + + + align:start position:0% + +tell you what before we get started on + + align:start position:0% +tell you what before we get started on + + + align:start position:0% +tell you what before we get started on +this recap + + align:start position:0% + + + + align:start position:0% + +we had + + align:start position:0% +we had + + + align:start position:0% +we had +we have two opportunities to make up our + + align:start position:0% +we have two opportunities to make up our + + + align:start position:0% +we have two opportunities to make up our +class with + + align:start position:0% +class with + + + align:start position:0% +class with +two um + + align:start position:0% +two um + + + align:start position:0% +two um +lectures + + align:start position:0% +lectures + + + align:start position:0% +lectures +outside of the class and uh + + align:start position:0% +outside of the class and uh + + + align:start position:0% +outside of the class and uh +i went miss bethke and i went to one of + + align:start position:0% +i went miss bethke and i went to one of + + + align:start position:0% +i went miss bethke and i went to one of +them + + align:start position:0% +them + + + align:start position:0% +them +she's going to give a report on that + + align:start position:0% +she's going to give a report on that + + + align:start position:0% +she's going to give a report on that +particular + + align:start position:0% + + + + align:start position:0% + +lecture and the other one comes up + + align:start position:0% +lecture and the other one comes up + + + align:start position:0% +lecture and the other one comes up +friday + + align:start position:0% +friday + + + align:start position:0% +friday +and i got a note back from + + align:start position:0% + + + + align:start position:0% + +nancy + + align:start position:0% +nancy + + + align:start position:0% +nancy +already saying + + align:start position:0% +already saying + + + align:start position:0% +already saying +all come please come looking forward to + + align:start position:0% +all come please come looking forward to + + + align:start position:0% +all come please come looking forward to +us the whole day + + align:start position:0% +us the whole day + + + align:start position:0% +us the whole day +so we can participate if necessary so um + + align:start position:0% +so we can participate if necessary so um + + + align:start position:0% +so we can participate if necessary so um +you don't mind if i make sure i got + + align:start position:0% +you don't mind if i make sure i got + + + align:start position:0% +you don't mind if i make sure i got +everything up while you're talking okay + + align:start position:0% + + + + align:start position:0% + +well i plan to be surprised by what you + + align:start position:0% +well i plan to be surprised by what you + + + align:start position:0% +well i plan to be surprised by what you +have to say + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +in the 1980s he was + + align:start position:0% +in the 1980s he was + + + align:start position:0% +in the 1980s he was +very active in fact a leader in + + align:start position:0% +very active in fact a leader in + + + align:start position:0% +very active in fact a leader in +developing internet protocol + + align:start position:0% +developing internet protocol + + + align:start position:0% +developing internet protocol +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +one of the chief architects of + + align:start position:0% +one of the chief architects of + + + align:start position:0% +one of the chief architects of +the internet + + align:start position:0% +the internet + + + align:start position:0% +the internet +um so + + align:start position:0% + + + + align:start position:0% + +his talk + + align:start position:0% +his talk + + + align:start position:0% +his talk +how things have changed since then and + + align:start position:0% +how things have changed since then and + + + align:start position:0% +how things have changed since then and +how he's trying to have a new outlook on + + align:start position:0% +how he's trying to have a new outlook on + + + align:start position:0% +how he's trying to have a new outlook on +designing the internet for the future + + align:start position:0% +designing the internet for the future + + + align:start position:0% +designing the internet for the future +so + + align:start position:0% +so + + + align:start position:0% +so +he started by saying the code and + + align:start position:0% +he started by saying the code and + + + align:start position:0% +he started by saying the code and +protocol that defined the internet the + + align:start position:0% +protocol that defined the internet the + + + align:start position:0% +protocol that defined the internet the +internet were originally created by a + + align:start position:0% +internet were originally created by a + + + align:start position:0% +internet were originally created by a +small group of computer scientists many + + align:start position:0% +small group of computer scientists many + + + align:start position:0% +small group of computer scientists many +here at mit you call these the techies + + align:start position:0% +here at mit you call these the techies + + + align:start position:0% +here at mit you call these the techies +and in the 1990s + + align:start position:0% +and in the 1990s + + + align:start position:0% +and in the 1990s +clark realized that these techies + + align:start position:0% +clark realized that these techies + + + align:start position:0% +clark realized that these techies +were not in charge anymore of the + + align:start position:0% +were not in charge anymore of the + + + align:start position:0% +were not in charge anymore of the +internet that + + align:start position:0% +internet that + + + align:start position:0% +internet that +instead economic social values politics + + align:start position:0% +instead economic social values politics + + + align:start position:0% +instead economic social values politics +this much larger social space + + align:start position:0% +this much larger social space + + + align:start position:0% +this much larger social space +was dictating the way the internet was + + align:start position:0% +was dictating the way the internet was + + + align:start position:0% +was dictating the way the internet was +developing and in return the internet + + align:start position:0% +developing and in return the internet + + + align:start position:0% +developing and in return the internet +was changing the social space + + align:start position:0% +was changing the social space + + + align:start position:0% +was changing the social space +it was deeply affecting the way people + + align:start position:0% +it was deeply affecting the way people + + + align:start position:0% +it was deeply affecting the way people +lived and the way society functions + + align:start position:0% +lived and the way society functions + + + align:start position:0% +lived and the way society functions +and so + + align:start position:0% +and so + + + align:start position:0% +and so +now clark's goals for his professional + + align:start position:0% +now clark's goals for his professional + + + align:start position:0% +now clark's goals for his professional +life + + align:start position:0% +life + + + align:start position:0% +life +are to understand this larger social + + align:start position:0% +are to understand this larger social + + + align:start position:0% +are to understand this larger social +space and how it interacts with the + + align:start position:0% +space and how it interacts with the + + + align:start position:0% +space and how it interacts with the +internet + + align:start position:0% +internet + + + align:start position:0% +internet +and then + + align:start position:0% +and then + + + align:start position:0% +and then +he said back derive the technology for + + align:start position:0% +he said back derive the technology for + + + align:start position:0% +he said back derive the technology for +the future and the infrastructure so + + align:start position:0% +the future and the infrastructure so + + + align:start position:0% +the future and the infrastructure so +instead of making incremental changes + + align:start position:0% +instead of making incremental changes + + + align:start position:0% +instead of making incremental changes +really understand this larger sort of + + align:start position:0% +really understand this larger sort of + + + align:start position:0% +really understand this larger sort of +space + + align:start position:0% + + + + align:start position:0% + +he found that he needed a word to + + align:start position:0% +he found that he needed a word to + + + align:start position:0% +he found that he needed a word to +describe + + align:start position:0% +describe + + + align:start position:0% +describe +the ever present and ongoing conflicts + + align:start position:0% +the ever present and ongoing conflicts + + + align:start position:0% +the ever present and ongoing conflicts +between different groups of users of the + + align:start position:0% +between different groups of users of the + + + align:start position:0% +between different groups of users of the +internet + + align:start position:0% +internet + + + align:start position:0% +internet +and he calls these social conflicts + + align:start position:0% +and he calls these social conflicts + + + align:start position:0% +and he calls these social conflicts +tussle so if you hear him talk or read + + align:start position:0% +tussle so if you hear him talk or read + + + align:start position:0% +tussle so if you hear him talk or read +one of his papers you'll see this word + + align:start position:0% +one of his papers you'll see this word + + + align:start position:0% +one of his papers you'll see this word +tussle + + align:start position:0% +tussle + + + align:start position:0% +tussle +and + + align:start position:0% +and + + + align:start position:0% +and +it's + + align:start position:0% +it's + + + align:start position:0% +it's +in his mind + + align:start position:0% +in his mind + + + align:start position:0% +in his mind +social + + align:start position:0% +social + + + align:start position:0% +social +phenomena + + align:start position:0% +phenomena + + + align:start position:0% +phenomena +social structures are always being + + align:start position:0% +social structures are always being + + + align:start position:0% +social structures are always being +tweaked by us there's never a final + + align:start position:0% +tweaked by us there's never a final + + + align:start position:0% +tweaked by us there's never a final +there's never a final way public schools + + align:start position:0% +there's never a final way public schools + + + align:start position:0% +there's never a final way public schools +are going to be this way forever and + + align:start position:0% +are going to be this way forever and + + + align:start position:0% +are going to be this way forever and +ever no we're always changing but + + align:start position:0% +ever no we're always changing but + + + align:start position:0% +ever no we're always changing but +engineers and computer scientists are + + align:start position:0% +engineers and computer scientists are + + + align:start position:0% +engineers and computer scientists are +used to designing for a final edge for + + align:start position:0% +used to designing for a final edge for + + + align:start position:0% +used to designing for a final edge for +final outcome + + align:start position:0% +final outcome + + + align:start position:0% +final outcome +and so we have computer scientists + + align:start position:0% +and so we have computer scientists + + + align:start position:0% +and so we have computer scientists +who are really + + align:start position:0% +who are really + + + align:start position:0% +who are really +being called upon to do social + + align:start position:0% +being called upon to do social + + + align:start position:0% +being called upon to do social +engineering + + align:start position:0% +engineering + + + align:start position:0% +engineering +to create the social space but their + + align:start position:0% +to create the social space but their + + + align:start position:0% +to create the social space but their +training is computer science and so + + align:start position:0% +training is computer science and so + + + align:start position:0% +training is computer science and so +there needs to be a rethinking of + + align:start position:0% +there needs to be a rethinking of + + + align:start position:0% +there needs to be a rethinking of +designing for tussle + + align:start position:0% +designing for tussle + + + align:start position:0% +designing for tussle +um + + align:start position:0% + + + + align:start position:0% + +let's see + + align:start position:0% +let's see + + + align:start position:0% +let's see +so what clark + + align:start position:0% +so what clark + + + align:start position:0% +so what clark +proposes is to try to predict these + + align:start position:0% +proposes is to try to predict these + + + align:start position:0% +proposes is to try to predict these +social tussles these conflicts between + + align:start position:0% +social tussles these conflicts between + + + align:start position:0% +social tussles these conflicts between +different groups of users of the + + align:start position:0% +different groups of users of the + + + align:start position:0% +different groups of users of the +internet + + align:start position:0% +internet + + + align:start position:0% +internet +and then create + + align:start position:0% +and then create + + + align:start position:0% +and then create +an infrastructure that is robust to + + align:start position:0% +an infrastructure that is robust to + + + align:start position:0% +an infrastructure that is robust to +those tussles + + align:start position:0% +those tussles + + + align:start position:0% +those tussles +so you have to be creative do a lot of + + align:start position:0% +so you have to be creative do a lot of + + + align:start position:0% +so you have to be creative do a lot of +predictive ways + + align:start position:0% +predictive ways + + + align:start position:0% +predictive ways +and he tries to predict these hustles by + + align:start position:0% +and he tries to predict these hustles by + + + align:start position:0% +and he tries to predict these hustles by +thinking about different groups of users + + align:start position:0% +thinking about different groups of users + + + align:start position:0% +thinking about different groups of users +so + + align:start position:0% +so + + + align:start position:0% +so +interactions between one person and + + align:start position:0% +interactions between one person and + + + align:start position:0% +interactions between one person and +another person on the internet + + align:start position:0% +another person on the internet + + + align:start position:0% +another person on the internet +interactions between different groups + + align:start position:0% +interactions between different groups + + + align:start position:0% +interactions between different groups +interactions that are + + align:start position:0% +interactions that are + + + align:start position:0% +interactions that are +common to a whole country and then + + align:start position:0% +common to a whole country and then + + + align:start position:0% +common to a whole country and then +interactions that are beyond country + + align:start position:0% +interactions that are beyond country + + + align:start position:0% +interactions that are beyond country +borders + + align:start position:0% +borders + + + align:start position:0% +borders +so some examples of tussles are over + + align:start position:0% +so some examples of tussles are over + + + align:start position:0% +so some examples of tussles are over +music sharing like no one predicted that + + align:start position:0% +music sharing like no one predicted that + + + align:start position:0% +music sharing like no one predicted that +the way they constructed the internet + + align:start position:0% +the way they constructed the internet + + + align:start position:0% +the way they constructed the internet +would + + align:start position:0% +would + + + align:start position:0% +would +sort of fuel this huge music sharing + + align:start position:0% +sort of fuel this huge music sharing + + + align:start position:0% +sort of fuel this huge music sharing +problem whether or not to enable + + align:start position:0% +problem whether or not to enable + + + align:start position:0% +problem whether or not to enable +encryption over the internet for a long + + align:start position:0% +encryption over the internet for a long + + + align:start position:0% +encryption over the internet for a long +time that government didn't want + + align:start position:0% +time that government didn't want + + + align:start position:0% +time that government didn't want +encryption to be enabled because then + + align:start position:0% +encryption to be enabled because then + + + align:start position:0% +encryption to be enabled because then +spies could use the internet + + align:start position:0% + + + + align:start position:0% + +very recently what google + + align:start position:0% +very recently what google + + + align:start position:0% +very recently what google +is doing in china to make search engines + + align:start position:0% +is doing in china to make search engines + + + align:start position:0% +is doing in china to make search engines +tailored to the + + align:start position:0% +tailored to the + + + align:start position:0% +tailored to the +laws or practices of a specific country + + align:start position:0% +laws or practices of a specific country + + + align:start position:0% +laws or practices of a specific country +he says + + align:start position:0% +he says + + + align:start position:0% +he says +what we have isn't is technology that is + + align:start position:0% +what we have isn't is technology that is + + + align:start position:0% +what we have isn't is technology that is +the same everywhere but policies and + + align:start position:0% +the same everywhere but policies and + + + align:start position:0% +the same everywhere but policies and +cultures that are very different + + align:start position:0% +cultures that are very different + + + align:start position:0% +cultures that are very different +and + + align:start position:0% +and + + + align:start position:0% +and +we + + align:start position:0% +we + + + align:start position:0% +we +are used to designing technology for + + align:start position:0% +are used to designing technology for + + + align:start position:0% +are used to designing technology for +specific cultures we don't know how to + + align:start position:0% +specific cultures we don't know how to + + + align:start position:0% +specific cultures we don't know how to +design technology + + align:start position:0% +design technology + + + align:start position:0% +design technology +in many different cultures at once + + align:start position:0% +in many different cultures at once + + + align:start position:0% +in many different cultures at once +so + + align:start position:0% +so + + + align:start position:0% +so +in conclusion + + align:start position:0% +in conclusion + + + align:start position:0% +in conclusion +he says part of predicting tussle is to + + align:start position:0% +he says part of predicting tussle is to + + + align:start position:0% +he says part of predicting tussle is to +think about the values that were + + align:start position:0% +think about the values that were + + + align:start position:0% +think about the values that were +embedded in the creation of the internet + + align:start position:0% +embedded in the creation of the internet + + + align:start position:0% +embedded in the creation of the internet +the the computer scientists who wrote + + align:start position:0% +the the computer scientists who wrote + + + align:start position:0% +the the computer scientists who wrote +the initial code and protocol + + align:start position:0% +the initial code and protocol + + + align:start position:0% +the initial code and protocol +did embed values user empowerment + + align:start position:0% +did embed values user empowerment + + + align:start position:0% +did embed values user empowerment +ability to be anonymous + + align:start position:0% +ability to be anonymous + + + align:start position:0% +ability to be anonymous +distrust of losing control + + align:start position:0% +distrust of losing control + + + align:start position:0% +distrust of losing control +and the idea that what is not forbidden + + align:start position:0% +and the idea that what is not forbidden + + + align:start position:0% +and the idea that what is not forbidden +is permitted so + + align:start position:0% +is permitted so + + + align:start position:0% +is permitted so +whether we like it or not they embedded + + align:start position:0% +whether we like it or not they embedded + + + align:start position:0% +whether we like it or not they embedded +those values in the way they wrote the + + align:start position:0% +those values in the way they wrote the + + + align:start position:0% +those values in the way they wrote the +performance + + align:start position:0% +performance + + + align:start position:0% +performance +so there's that and one set and then + + align:start position:0% +so there's that and one set and then + + + align:start position:0% +so there's that and one set and then +there's values that we sort of expect + + align:start position:0% +there's values that we sort of expect + + + align:start position:0% +there's values that we sort of expect +that users expect freedom from attack + + align:start position:0% +that users expect freedom from attack + + + align:start position:0% +that users expect freedom from attack +stability + + align:start position:0% +stability + + + align:start position:0% +stability +freedom of speech access to information + + align:start position:0% +freedom of speech access to information + + + align:start position:0% +freedom of speech access to information +so those values that the creators + + align:start position:0% +so those values that the creators + + + align:start position:0% +so those values that the creators +embedded the values that users expect + + align:start position:0% +embedded the values that users expect + + + align:start position:0% +embedded the values that users expect +are in conflict and then there's + + align:start position:0% + + + + align:start position:0% + +there were some good questions from the + + align:start position:0% +there were some good questions from the + + + align:start position:0% +there were some good questions from the +floor + + align:start position:0% + + + + align:start position:0% + +one person + + align:start position:0% + + + + align:start position:0% + +let me see how did he frame that + + align:start position:0% +let me see how did he frame that + + + align:start position:0% +let me see how did he frame that +question about happiness + + align:start position:0% + + + + align:start position:0% + +someone asked if + + align:start position:0% +someone asked if + + + align:start position:0% +someone asked if +in thinking about + + align:start position:0% +in thinking about + + + align:start position:0% +in thinking about +what the internet should enable + + align:start position:0% +what the internet should enable + + + align:start position:0% +what the internet should enable +or what its value should be do you ever + + align:start position:0% +or what its value should be do you ever + + + align:start position:0% +or what its value should be do you ever +consider one of its purposes to be + + align:start position:0% +consider one of its purposes to be + + + align:start position:0% +consider one of its purposes to be +enabling the pursuit of happiness + + align:start position:0% +enabling the pursuit of happiness + + + align:start position:0% +enabling the pursuit of happiness +that's kind of what the person asked yes + + align:start position:0% +that's kind of what the person asked yes + + + align:start position:0% +that's kind of what the person asked yes +uh the way he asked + + align:start position:0% +uh the way he asked + + + align:start position:0% +uh the way he asked +was + + align:start position:0% + + + + align:start position:0% + +a question in political science + + align:start position:0% +a question in political science + + + align:start position:0% +a question in political science +the + + align:start position:0% +the + + + align:start position:0% +the +the notion here in the united states + + align:start position:0% +the notion here in the united states + + + align:start position:0% +the notion here in the united states +that one should be free + + align:start position:0% +that one should be free + + + align:start position:0% +that one should be free +to pursue happiness + + align:start position:0% +to pursue happiness + + + align:start position:0% +to pursue happiness +okay + + align:start position:0% +okay + + + align:start position:0% +okay +but + + align:start position:0% +but + + + align:start position:0% +but +we all know that that + + align:start position:0% +we all know that that + + + align:start position:0% +we all know that that +pursuit of happiness concept comes from + + align:start position:0% +pursuit of happiness concept comes from + + + align:start position:0% +pursuit of happiness concept comes from +the happiness principle in ethics + + align:start position:0% + + + + align:start position:0% + +that you have + + align:start position:0% +that you have + + + align:start position:0% +that you have +you should be free to pursue + + align:start position:0% +you should be free to pursue + + + align:start position:0% +you should be free to pursue +happiness + + align:start position:0% +happiness + + + align:start position:0% +happiness +and + + align:start position:0% +and + + + align:start position:0% +and +i think dave clark + + align:start position:0% + + + + align:start position:0% + +took it the way that it was put + + align:start position:0% +took it the way that it was put + + + align:start position:0% +took it the way that it was put +as a question of political science + + align:start position:0% +as a question of political science + + + align:start position:0% +as a question of political science +and + + align:start position:0% +and + + + align:start position:0% +and +uh didn't have + + align:start position:0% +uh didn't have + + + align:start position:0% +uh didn't have +much to say about it i'm sure that i + + align:start position:0% +much to say about it i'm sure that i + + + align:start position:0% +much to say about it i'm sure that i +wouldn't have had anything to say about + + align:start position:0% +wouldn't have had anything to say about + + + align:start position:0% +wouldn't have had anything to say about +it + + align:start position:0% +it + + + align:start position:0% +it +but the question + + align:start position:0% +but the question + + + align:start position:0% +but the question +when you look at it from the standpoint + + align:start position:0% +when you look at it from the standpoint + + + align:start position:0% +when you look at it from the standpoint +of the happiness principle now that's a + + align:start position:0% +of the happiness principle now that's a + + + align:start position:0% +of the happiness principle now that's a +that is um + + align:start position:0% +that is um + + + align:start position:0% +that is um +an intriguing question does the internet + + align:start position:0% +an intriguing question does the internet + + + align:start position:0% +an intriguing question does the internet +make people happy + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% + + + + align:start position:0% + +i'll tell you one way that + + align:start position:0% +i'll tell you one way that + + + align:start position:0% +i'll tell you one way that +we i think we shouldn't answer the + + align:start position:0% +we i think we shouldn't answer the + + + align:start position:0% +we i think we shouldn't answer the +question what would life be like if we + + align:start position:0% +question what would life be like if we + + + align:start position:0% +question what would life be like if we +didn't have it + + align:start position:0% +didn't have it + + + align:start position:0% +didn't have it +all right the reason i say that that's + + align:start position:0% +all right the reason i say that that's + + + align:start position:0% +all right the reason i say that that's +not a good way to answer the question is + + align:start position:0% +not a good way to answer the question is + + + align:start position:0% +not a good way to answer the question is +that a drug addict + + align:start position:0% +that a drug addict + + + align:start position:0% +that a drug addict +says the same thing + + align:start position:0% +says the same thing + + + align:start position:0% +says the same thing +what would it be like if i didn't have + + align:start position:0% +what would it be like if i didn't have + + + align:start position:0% +what would it be like if i didn't have +my drugs + + align:start position:0% + + + + align:start position:0% + +we might be addicted to this thing + + align:start position:0% + + + + align:start position:0% + +called the internet + + align:start position:0% +called the internet + + + align:start position:0% +called the internet +and if we are addicted to it then i + + align:start position:0% +and if we are addicted to it then i + + + align:start position:0% +and if we are addicted to it then i +don't think that that kind of happiness + + align:start position:0% +don't think that that kind of happiness + + + align:start position:0% +don't think that that kind of happiness +is what john stuart mills talking about + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so uh let's let's let let's not leave + + align:start position:0% +so uh let's let's let let's not leave + + + align:start position:0% +so uh let's let's let let's not leave +that as a rhetorical question does this + + align:start position:0% +that as a rhetorical question does this + + + align:start position:0% +that as a rhetorical question does this +does + + align:start position:0% +does + + + align:start position:0% +does +let's pursue that for a second does the + + align:start position:0% +let's pursue that for a second does the + + + align:start position:0% +let's pursue that for a second does the +internet make anybody happy + + align:start position:0% + + + + align:start position:0% + +all right how would you break it down + + align:start position:0% +all right how would you break it down + + + align:start position:0% +all right how would you break it down +then + + align:start position:0% + + + + align:start position:0% + +i'm asking does it make people happy + + align:start position:0% +i'm asking does it make people happy + + + align:start position:0% +i'm asking does it make people happy +is it good + + align:start position:0% + + + + align:start position:0% + +that's for everybody is it good i mean + + align:start position:0% +that's for everybody is it good i mean + + + align:start position:0% +that's for everybody is it good i mean +do we really like the internet + + align:start position:0% + + + + align:start position:0% + +yes + + align:start position:0% + + + + align:start position:0% + +okay um so you're saying that everything + + align:start position:0% +okay um so you're saying that everything + + + align:start position:0% +okay um so you're saying that everything +has a price tag attached to it the price + + align:start position:0% +has a price tag attached to it the price + + + align:start position:0% +has a price tag attached to it the price +to pay for everything and you're willing + + align:start position:0% +to pay for everything and you're willing + + + align:start position:0% +to pay for everything and you're willing +to pay the price for this thing + + align:start position:0% + + + + align:start position:0% + +keep talking + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% + + + + align:start position:0% + +if + + align:start position:0% + + + + align:start position:0% + +i have one advantage + + align:start position:0% +i have one advantage + + + align:start position:0% +i have one advantage +uh + + align:start position:0% +uh + + + align:start position:0% +uh +i'm 63 years old + + align:start position:0% +i'm 63 years old + + + align:start position:0% +i'm 63 years old +i can remember when there was + + align:start position:0% +i can remember when there was + + + align:start position:0% +i can remember when there was +no internet or if if there was an + + align:start position:0% +no internet or if if there was an + + + align:start position:0% +no internet or if if there was an +internet nobody knew about it except the + + align:start position:0% +internet nobody knew about it except the + + + align:start position:0% +internet nobody knew about it except the +uh + + align:start position:0% +uh + + + align:start position:0% +uh +specialists + + align:start position:0% +specialists + + + align:start position:0% +specialists +and i can put myself in a position of + + align:start position:0% +and i can put myself in a position of + + + align:start position:0% +and i can put myself in a position of +asking myself + + align:start position:0% +asking myself + + + align:start position:0% +asking myself +if somebody brought an idea for the + + align:start position:0% +if somebody brought an idea for the + + + align:start position:0% +if somebody brought an idea for the +internet before me and showed me the + + align:start position:0% +internet before me and showed me the + + + align:start position:0% +internet before me and showed me the +price + + align:start position:0% +price + + + align:start position:0% +price +would i buy + + align:start position:0% + + + + align:start position:0% + +would i have bought it in 19. + + align:start position:0% + + + + align:start position:0% + +uh the only thing that i can think that + + align:start position:0% +uh the only thing that i can think that + + + align:start position:0% +uh the only thing that i can think that +would have given me pause about that + + align:start position:0% +would have given me pause about that + + + align:start position:0% +would have given me pause about that +whole thing was privacy + + align:start position:0% +whole thing was privacy + + + align:start position:0% +whole thing was privacy +that a private that a a a cost that i + + align:start position:0% +that a private that a a a cost that i + + + align:start position:0% +that a private that a a a cost that i +might have to pay for for this whole + + align:start position:0% +might have to pay for for this whole + + + align:start position:0% +might have to pay for for this whole +thing is that my social security number + + align:start position:0% +thing is that my social security number + + + align:start position:0% +thing is that my social security number +everything + + align:start position:0% +everything + + + align:start position:0% +everything +gets right out for anybody to use + + align:start position:0% +gets right out for anybody to use + + + align:start position:0% +gets right out for anybody to use +and + + align:start position:0% +and + + + align:start position:0% +and +uh + + align:start position:0% +uh + + + align:start position:0% +uh +i'm i'm putting aside + + align:start position:0% +i'm i'm putting aside + + + align:start position:0% +i'm i'm putting aside +i'm not putting aside but i'm not + + align:start position:0% +i'm not putting aside but i'm not + + + align:start position:0% +i'm not putting aside but i'm not +focusing on the fact + + align:start position:0% +focusing on the fact + + + align:start position:0% +focusing on the fact +that they can get in my bank account + + align:start position:0% +that they can get in my bank account + + + align:start position:0% +that they can get in my bank account +transfer funds + + align:start position:0% +transfer funds + + + align:start position:0% +transfer funds +i'm really talking about how they can do + + align:start position:0% +i'm really talking about how they can do + + + align:start position:0% +i'm really talking about how they can do +all sorts of other things with things + + align:start position:0% +all sorts of other things with things + + + align:start position:0% +all sorts of other things with things +that are very private to me + + align:start position:0% +that are very private to me + + + align:start position:0% +that are very private to me +and things that i have a legitimate + + align:start position:0% +and things that i have a legitimate + + + align:start position:0% +and things that i have a legitimate +right not to tell you or anybody else + + align:start position:0% +right not to tell you or anybody else + + + align:start position:0% +right not to tell you or anybody else +now i'm + + align:start position:0% +now i'm + + + align:start position:0% +now i'm +i'm still in 1960 i still have this + + align:start position:0% +i'm still in 1960 i still have this + + + align:start position:0% +i'm still in 1960 i still have this +thing in my mind before me what i want + + align:start position:0% +thing in my mind before me what i want + + + align:start position:0% +thing in my mind before me what i want +it + + align:start position:0% +it + + + align:start position:0% +it +tell me all of the uses all of the bad + + align:start position:0% +tell me all of the uses all of the bad + + + align:start position:0% +tell me all of the uses all of the bad +things + + align:start position:0% + + + + align:start position:0% + +i'm i'm not so sure what i would say + + align:start position:0% + + + + align:start position:0% + +i am not so sure about what i would say + + align:start position:0% + + + + align:start position:0% + +that being unsure makes a statement + + align:start position:0% +that being unsure makes a statement + + + align:start position:0% +that being unsure makes a statement +uh is you know given that i was in that + + align:start position:0% +uh is you know given that i was in that + + + align:start position:0% +uh is you know given that i was in that +position and had all of these big + + align:start position:0% +position and had all of these big + + + align:start position:0% +position and had all of these big +choices and understood them + + align:start position:0% +choices and understood them + + + align:start position:0% +choices and understood them +like i do now + + align:start position:0% +like i do now + + + align:start position:0% +like i do now +would i take this thing and i probably + + align:start position:0% +would i take this thing and i probably + + + align:start position:0% +would i take this thing and i probably +would have a big difficulty with it i + + align:start position:0% +would have a big difficulty with it i + + + align:start position:0% +would have a big difficulty with it i +would say well uh uh thinking right now + + align:start position:0% +would say well uh uh thinking right now + + + align:start position:0% +would say well uh uh thinking right now +i would probably say something like well + + align:start position:0% +i would probably say something like well + + + align:start position:0% +i would probably say something like well +let's see if we can't work out the + + align:start position:0% +let's see if we can't work out the + + + align:start position:0% +let's see if we can't work out the +privacy issue then bring it back + + align:start position:0% +privacy issue then bring it back + + + align:start position:0% +privacy issue then bring it back +well we might not be able to work that + + align:start position:0% +well we might not be able to work that + + + align:start position:0% +well we might not be able to work that +out for two or three years four or five + + align:start position:0% +out for two or three years four or five + + + align:start position:0% +out for two or three years four or five +years well hopefully i'll still be able + + align:start position:0% +years well hopefully i'll still be able + + + align:start position:0% +years well hopefully i'll still be able +to bring it back then i probably + + align:start position:0% +to bring it back then i probably + + + align:start position:0% +to bring it back then i probably +wouldn't want to do it without that + + align:start position:0% +wouldn't want to do it without that + + + align:start position:0% +wouldn't want to do it without that +issue solved i probably wouldn't want to + + align:start position:0% +issue solved i probably wouldn't want to + + + align:start position:0% +issue solved i probably wouldn't want to +go into it + + align:start position:0% +go into it + + + align:start position:0% +go into it +um + + align:start position:0% + + + + align:start position:0% + +they never saw it + + align:start position:0% + + + + align:start position:0% + +all right then let's ask another + + align:start position:0% +all right then let's ask another + + + align:start position:0% +all right then let's ask another +question for this class + + align:start position:0% + + + + align:start position:0% + +can we find where any human being did + + align:start position:0% +can we find where any human being did + + + align:start position:0% +can we find where any human being did +anything wrong in terms of uh + + align:start position:0% +anything wrong in terms of uh + + + align:start position:0% +anything wrong in terms of uh +the internet or + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +all right any uh questions of con + + align:start position:0% + + + + align:start position:0% + +no i i remember now what i was going to + + align:start position:0% +no i i remember now what i was going to + + + align:start position:0% +no i i remember now what i was going to +say uh what you had to say was more + + align:start position:0% +say uh what you had to say was more + + + align:start position:0% +say uh what you had to say was more +intriguing but i was going to ask um + + align:start position:0% +intriguing but i was going to ask um + + + align:start position:0% +intriguing but i was going to ask um +is the internet can we talk about the + + align:start position:0% +is the internet can we talk about the + + + align:start position:0% +is the internet can we talk about the +internet + + align:start position:0% +internet + + + align:start position:0% +internet +as being + + align:start position:0% +as being + + + align:start position:0% +as being +a um + + align:start position:0% + + + + align:start position:0% + +moral agent is the can is that is the + + align:start position:0% +moral agent is the can is that is the + + + align:start position:0% +moral agent is the can is that is the +internet itself bad + + align:start position:0% +internet itself bad + + + align:start position:0% +internet itself bad +now now the internet becomes becomes a + + align:start position:0% +now now the internet becomes becomes a + + + align:start position:0% +now now the internet becomes becomes a +very interesting question about a + + align:start position:0% +very interesting question about a + + + align:start position:0% +very interesting question about a +technology being bad because the + + align:start position:0% +technology being bad because the + + + align:start position:0% +technology being bad because the +technology is activated + + align:start position:0% +technology is activated + + + align:start position:0% +technology is activated +uh by human beings all the time it's + + align:start position:0% +uh by human beings all the time it's + + + align:start position:0% +uh by human beings all the time it's +what human beings are doing + + align:start position:0% +what human beings are doing + + + align:start position:0% +what human beings are doing +but now + + align:start position:0% +but now + + + align:start position:0% +but now +dave clark comes in and says + + align:start position:0% +dave clark comes in and says + + + align:start position:0% +dave clark comes in and says +that + + align:start position:0% +that + + + align:start position:0% +that +it's fair to think about the internet as + + align:start position:0% +it's fair to think about the internet as + + + align:start position:0% +it's fair to think about the internet as +an object that has a life of its own + + align:start position:0% +an object that has a life of its own + + + align:start position:0% +an object that has a life of its own +that the rest of us + + align:start position:0% +that the rest of us + + + align:start position:0% +that the rest of us +do not control this thing totally + + align:start position:0% +do not control this thing totally + + + align:start position:0% +do not control this thing totally +so can we think about it in moral terms + + align:start position:0% + + + + align:start position:0% + +uh let's leave that as a rhetorical + + align:start position:0% +uh let's leave that as a rhetorical + + + align:start position:0% +uh let's leave that as a rhetorical +question + + align:start position:0% +question + + + align:start position:0% +question +for right now we'll come back at the end + + align:start position:0% +for right now we'll come back at the end + + + align:start position:0% +for right now we'll come back at the end +of class + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +that question's still on the floor but i + + align:start position:0% +that question's still on the floor but i + + + align:start position:0% +that question's still on the floor but i +want to give a recapitulation of a talk + + align:start position:0% +want to give a recapitulation of a talk + + + align:start position:0% +want to give a recapitulation of a talk +that i gave yesterday which i wrote for + + align:start position:0% +that i gave yesterday which i wrote for + + + align:start position:0% +that i gave yesterday which i wrote for +this class as well it's a recapitulation + + align:start position:0% +this class as well it's a recapitulation + + + align:start position:0% +this class as well it's a recapitulation +of the course + + align:start position:0% +of the course + + + align:start position:0% +of the course +and the class that i gave yesterday was + + align:start position:0% +and the class that i gave yesterday was + + + align:start position:0% +and the class that i gave yesterday was +for + + align:start position:0% +for + + + align:start position:0% +for +this course + + align:start position:0% +this course + + + align:start position:0% +this course +called managing nuclear technology + + align:start position:0% +called managing nuclear technology + + + align:start position:0% +called managing nuclear technology +out of the nuclear engineering program + + align:start position:0% +out of the nuclear engineering program + + + align:start position:0% +out of the nuclear engineering program +here + + align:start position:0% +here + + + align:start position:0% +here +and + + align:start position:0% + + + + align:start position:0% + +it was a graduate class + + align:start position:0% +it was a graduate class + + + align:start position:0% +it was a graduate class +but not everybody in the class was a + + align:start position:0% +but not everybody in the class was a + + + align:start position:0% +but not everybody in the class was a +nuclear engineer some of them were tpp + + align:start position:0% +nuclear engineer some of them were tpp + + + align:start position:0% +nuclear engineer some of them were tpp +uh majors uh well another thing that + + align:start position:0% +uh majors uh well another thing that + + + align:start position:0% +uh majors uh well another thing that +made the class very interesting was that + + align:start position:0% +made the class very interesting was that + + + align:start position:0% +made the class very interesting was that +there were two students in there from + + align:start position:0% +there were two students in there from + + + align:start position:0% +there were two students in there from +france + + align:start position:0% +france + + + align:start position:0% +france +that was interesting to me because + + align:start position:0% +that was interesting to me because + + + align:start position:0% +that was interesting to me because +france has embraced + + align:start position:0% +france has embraced + + + align:start position:0% +france has embraced +nuclear power whereas the united states + + align:start position:0% +nuclear power whereas the united states + + + align:start position:0% +nuclear power whereas the united states +has had problems with it + + align:start position:0% + + + + align:start position:0% + +so um + + align:start position:0% + + + + align:start position:0% + +the + + align:start position:0% +the + + + align:start position:0% +the +the outline of the talk uh + + align:start position:0% + + + + align:start position:0% + +is as follows we want to talk about what + + align:start position:0% +is as follows we want to talk about what + + + align:start position:0% +is as follows we want to talk about what +were the times like + + align:start position:0% +were the times like + + + align:start position:0% +were the times like +and i'm talking about mainly in the + + align:start position:0% +and i'm talking about mainly in the + + + align:start position:0% +and i'm talking about mainly in the +united states + + align:start position:0% +united states + + + align:start position:0% +united states +but not because the united states is + + align:start position:0% +but not because the united states is + + + align:start position:0% +but not because the united states is +more important than anything else + + align:start position:0% +more important than anything else + + + align:start position:0% +more important than anything else +but because we're here in the united + + align:start position:0% +but because we're here in the united + + + align:start position:0% +but because we're here in the united +states + + align:start position:0% +states + + + align:start position:0% +states +uh + + align:start position:0% +uh + + + align:start position:0% +uh +and that brought about what we call the + + align:start position:0% +and that brought about what we call the + + + align:start position:0% +and that brought about what we call the +sts movement + + align:start position:0% +sts movement + + + align:start position:0% +sts movement +science technology and society + + align:start position:0% +science technology and society + + + align:start position:0% +science technology and society +you know we have an sts department here + + align:start position:0% +you know we have an sts department here + + + align:start position:0% +you know we have an sts department here +uh our sts department + + align:start position:0% +uh our sts department + + + align:start position:0% +uh our sts department +does have a focus and + + align:start position:0% +does have a focus and + + + align:start position:0% +does have a focus and +not to the exclusion of everything else + + align:start position:0% +not to the exclusion of everything else + + + align:start position:0% +not to the exclusion of everything else +but it focuses on + + align:start position:0% +but it focuses on + + + align:start position:0% +but it focuses on +uh + + align:start position:0% +uh + + + align:start position:0% +uh +history of technology + + align:start position:0% + + + + align:start position:0% + +but sts in the beginning uh + + align:start position:0% +but sts in the beginning uh + + + align:start position:0% +but sts in the beginning uh +was a response to many issues in + + align:start position:0% +was a response to many issues in + + + align:start position:0% +was a response to many issues in +the american life and i'll talk about + + align:start position:0% +the american life and i'll talk about + + + align:start position:0% +the american life and i'll talk about +those in which i call the times and out + + align:start position:0% +those in which i call the times and out + + + align:start position:0% +those in which i call the times and out +of it came + + align:start position:0% +of it came + + + align:start position:0% +of it came +a + + align:start position:0% +a + + + align:start position:0% +a +a + + align:start position:0% +a + + + align:start position:0% +a +an engagement of two learning + + align:start position:0% +an engagement of two learning + + + align:start position:0% +an engagement of two learning +disciplines + + align:start position:0% + + + + align:start position:0% + +but the engagements that we're talking + + align:start position:0% +but the engagements that we're talking + + + align:start position:0% +but the engagements that we're talking +about mostly are going to be with ethics + + align:start position:0% +about mostly are going to be with ethics + + + align:start position:0% +about mostly are going to be with ethics +and with engineering + + align:start position:0% + + + + align:start position:0% + +which gives rise to engineering ethics + + align:start position:0% + + + + align:start position:0% + +and we'll look at a particular case + + align:start position:0% +and we'll look at a particular case + + + align:start position:0% +and we'll look at a particular case +study of tmi the which is three mile + + align:start position:0% +study of tmi the which is three mile + + + align:start position:0% +study of tmi the which is three mile +island nuclear they call it an accident + + align:start position:0% +island nuclear they call it an accident + + + align:start position:0% +island nuclear they call it an accident +that's the official term + + align:start position:0% +that's the official term + + + align:start position:0% +that's the official term +uh 1979. we'll look at a case study of + + align:start position:0% +uh 1979. we'll look at a case study of + + + align:start position:0% +uh 1979. we'll look at a case study of +that we did look at it a little bit in + + align:start position:0% +that we did look at it a little bit in + + + align:start position:0% +that we did look at it a little bit in +class we read a little bit about that + + align:start position:0% +class we read a little bit about that + + + align:start position:0% +class we read a little bit about that +but i would like to go a little bit + + align:start position:0% +but i would like to go a little bit + + + align:start position:0% +but i would like to go a little bit +deeper into it today + + align:start position:0% +deeper into it today + + + align:start position:0% +deeper into it today +and then let's talk about + + align:start position:0% +and then let's talk about + + + align:start position:0% +and then let's talk about +whether or not we're making a + + align:start position:0% +whether or not we're making a + + + align:start position:0% +whether or not we're making a +a world for ourselves that we want + + align:start position:0% + + + + align:start position:0% + +uh and i'm asking the question about is + + align:start position:0% +uh and i'm asking the question about is + + + align:start position:0% +uh and i'm asking the question about is +or do we really have a brave new world + + align:start position:0% +or do we really have a brave new world + + + align:start position:0% +or do we really have a brave new world +and if that's good + + align:start position:0% +and if that's good + + + align:start position:0% +and if that's good +if you read aldous huxley's brave new + + align:start position:0% +if you read aldous huxley's brave new + + + align:start position:0% +if you read aldous huxley's brave new +world that was not a place that we would + + align:start position:0% +world that was not a place that we would + + + align:start position:0% +world that was not a place that we would +really want + + align:start position:0% +really want + + + align:start position:0% +really want +human beings grown in + + align:start position:0% +human beings grown in + + + align:start position:0% +human beings grown in +hatcheries they call them + + align:start position:0% +hatcheries they call them + + + align:start position:0% +hatcheries they call them +okay but nevertheless this is a good + + align:start position:0% +okay but nevertheless this is a good + + + align:start position:0% +okay but nevertheless this is a good +term to raise the question + + align:start position:0% + + + + align:start position:0% + +so this is the outline these are the + + align:start position:0% +so this is the outline these are the + + + align:start position:0% +so this is the outline these are the +main sections of this talk + + align:start position:0% +main sections of this talk + + + align:start position:0% +main sections of this talk +and when it comes to engineering ethics + + align:start position:0% +and when it comes to engineering ethics + + + align:start position:0% +and when it comes to engineering ethics +there were a number of issues that + + align:start position:0% +there were a number of issues that + + + align:start position:0% +there were a number of issues that +motivated the whole thing um + + align:start position:0% +motivated the whole thing um + + + align:start position:0% +motivated the whole thing um +one was in 1974 spiro t agnews + + align:start position:0% +one was in 1974 spiro t agnews + + + align:start position:0% +one was in 1974 spiro t agnews +i was about to say as you recall + + align:start position:0% +i was about to say as you recall + + + align:start position:0% +i was about to say as you recall +spiro t agnew was vice president of the + + align:start position:0% +spiro t agnew was vice president of the + + + align:start position:0% +spiro t agnew was vice president of the +united states + + align:start position:0% +united states + + + align:start position:0% +united states +he was accused + + align:start position:0% +he was accused + + + align:start position:0% +he was accused +and resigned as a result of the scandal + + align:start position:0% +and resigned as a result of the scandal + + + align:start position:0% +and resigned as a result of the scandal +those are two for terms of art for this + + align:start position:0% +those are two for terms of art for this + + + align:start position:0% +those are two for terms of art for this +particular case + + align:start position:0% +particular case + + + align:start position:0% +particular case +a accusation and scandal not conviction + + align:start position:0% +a accusation and scandal not conviction + + + align:start position:0% +a accusation and scandal not conviction +he was accused of taking bribes + + align:start position:0% +he was accused of taking bribes + + + align:start position:0% +he was accused of taking bribes +from engineers + + align:start position:0% + + + + align:start position:0% + +and the scandal that broke out over it + + align:start position:0% +and the scandal that broke out over it + + + align:start position:0% +and the scandal that broke out over it +prompted his resignation + + align:start position:0% +prompted his resignation + + + align:start position:0% +prompted his resignation +and gave motivation + + align:start position:0% +and gave motivation + + + align:start position:0% +and gave motivation +for this thing called engineering ethics + + align:start position:0% + + + + align:start position:0% + +uh the challenger accident + + align:start position:0% +uh the challenger accident + + + align:start position:0% +uh the challenger accident +uh was one that um + + align:start position:0% +uh was one that um + + + align:start position:0% +uh was one that um +we have looked at + + align:start position:0% +we have looked at + + + align:start position:0% +we have looked at +and in the challenger accident uh we + + align:start position:0% +and in the challenger accident uh we + + + align:start position:0% +and in the challenger accident uh we +looked at the + + align:start position:0% +looked at the + + + align:start position:0% +looked at the +issue of whistleblowing + + align:start position:0% +issue of whistleblowing + + + align:start position:0% +issue of whistleblowing +we looked at the question of what + + align:start position:0% +we looked at the question of what + + + align:start position:0% +we looked at the question of what +engineering really is are we as + + align:start position:0% +engineering really is are we as + + + align:start position:0% +engineering really is are we as +engineering + + align:start position:0% +engineering + + + align:start position:0% +engineering +inherently lethal + + align:start position:0% +inherently lethal + + + align:start position:0% +inherently lethal +and this particular one + + align:start position:0% +and this particular one + + + align:start position:0% +and this particular one +uh was interesting to us from a number + + align:start position:0% +uh was interesting to us from a number + + + align:start position:0% +uh was interesting to us from a number +of reasons but not the least of which + + align:start position:0% +of reasons but not the least of which + + + align:start position:0% +of reasons but not the least of which +was that this was the first + + align:start position:0% +was that this was the first + + + align:start position:0% +was that this was the first +massive flight with a + + align:start position:0% +massive flight with a + + + align:start position:0% +massive flight with a +shuttle that had a person on board + + align:start position:0% +shuttle that had a person on board + + + align:start position:0% +shuttle that had a person on board +who was neither an employee of nasa nor + + align:start position:0% +who was neither an employee of nasa nor + + + align:start position:0% +who was neither an employee of nasa nor +of the military + + align:start position:0% + + + + align:start position:0% + +which meant that that person was not an + + align:start position:0% +which meant that that person was not an + + + align:start position:0% +which meant that that person was not an +expert + + align:start position:0% +expert + + + align:start position:0% +expert +on this + + align:start position:0% +on this + + + align:start position:0% +on this +that was mcauliffe who was a school + + align:start position:0% +that was mcauliffe who was a school + + + align:start position:0% +that was mcauliffe who was a school +teacher + + align:start position:0% +teacher + + + align:start position:0% +teacher +and they were trying to make the case + + align:start position:0% +and they were trying to make the case + + + align:start position:0% +and they were trying to make the case +that space travel + + align:start position:0% +that space travel + + + align:start position:0% +that space travel +could be for the for ordinary people + + align:start position:0% +could be for the for ordinary people + + + align:start position:0% +could be for the for ordinary people +just like getting on an airplane is for + + align:start position:0% +just like getting on an airplane is for + + + align:start position:0% +just like getting on an airplane is for +ordinary people now + + align:start position:0% +ordinary people now + + + align:start position:0% +ordinary people now +all right + + align:start position:0% +all right + + + align:start position:0% +all right +bo paul introduced + + align:start position:0% +bo paul introduced + + + align:start position:0% +bo paul introduced +the issue of safety standards across + + align:start position:0% +the issue of safety standards across + + + align:start position:0% +the issue of safety standards across +cultures + + align:start position:0% +cultures + + + align:start position:0% +cultures +that in the united states we had union + + align:start position:0% +that in the united states we had union + + + align:start position:0% +that in the united states we had union +carbide had some safety standards for + + align:start position:0% +carbide had some safety standards for + + + align:start position:0% +carbide had some safety standards for +its chemical plants + + align:start position:0% +its chemical plants + + + align:start position:0% +its chemical plants +they went to india there were different + + align:start position:0% +they went to india there were different + + + align:start position:0% +they went to india there were different +standards + + align:start position:0% +standards + + + align:start position:0% +standards +an accident occurred killed 3 000 people + + align:start position:0% +an accident occurred killed 3 000 people + + + align:start position:0% +an accident occurred killed 3 000 people +children included + + align:start position:0% +children included + + + align:start position:0% +children included +and + + align:start position:0% +and + + + align:start position:0% +and +the question is as you just raised the + + align:start position:0% +the question is as you just raised the + + + align:start position:0% +the question is as you just raised the +question about google + + align:start position:0% +question about google + + + align:start position:0% +question about google +in china what do we do about + + align:start position:0% +in china what do we do about + + + align:start position:0% +in china what do we do about +ethical standards i'm not talking about + + align:start position:0% +ethical standards i'm not talking about + + + align:start position:0% +ethical standards i'm not talking about +legal standards ethical standards + + align:start position:0% +legal standards ethical standards + + + align:start position:0% +legal standards ethical standards +are across cultures + + align:start position:0% +are across cultures + + + align:start position:0% +are across cultures +raises that issue + + align:start position:0% +raises that issue + + + align:start position:0% +raises that issue +and three mile allen is something i'll + + align:start position:0% +and three mile allen is something i'll + + + align:start position:0% +and three mile allen is something i'll +talk about a little in a little bit of + + align:start position:0% +talk about a little in a little bit of + + + align:start position:0% +talk about a little in a little bit of +detail because we haven't talked about + + align:start position:0% +detail because we haven't talked about + + + align:start position:0% +detail because we haven't talked about +it in detail + + align:start position:0% +it in detail + + + align:start position:0% +it in detail +in the class yet + + align:start position:0% + + + + align:start position:0% + +the sds movement did not include was not + + align:start position:0% +the sds movement did not include was not + + + align:start position:0% +the sds movement did not include was not +restricted engineering ethics + + align:start position:0% +restricted engineering ethics + + + align:start position:0% +restricted engineering ethics +there's a discipline called + + align:start position:0% +there's a discipline called + + + align:start position:0% +there's a discipline called +environmental ethics + + align:start position:0% + + + + align:start position:0% + +there's a discipline and when i say + + align:start position:0% +there's a discipline and when i say + + + align:start position:0% +there's a discipline and when i say +discipline i'm talking about + + align:start position:0% + + + + align:start position:0% + +a world view + + align:start position:0% +a world view + + + align:start position:0% +a world view +a way of looking at the world we talked + + align:start position:0% +a way of looking at the world we talked + + + align:start position:0% +a way of looking at the world we talked +about that 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body + + + align:start position:0% +cultivate that body +that cultivates that body of learning + + align:start position:0% +that cultivates that body of learning + + + align:start position:0% +that cultivates that body of learning +and + + align:start position:0% +and + + + align:start position:0% +and +university degree granting programs + + align:start position:0% +university degree granting programs + + + align:start position:0% +university degree granting programs +so if you do not get a degree in + + align:start position:0% +so if you do not get a degree in + + + align:start position:0% +so if you do not get a degree in +business ethics + + align:start position:0% +business ethics + + + align:start position:0% +business ethics +you can certainly get a degree in sts + + align:start position:0% +you can certainly get a degree in sts + + + align:start position:0% +you can certainly get a degree in sts +even the phd + + align:start position:0% +even the phd + + + align:start 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+ + + align:start position:0% + +in the class yesterday that uh this + + align:start position:0% +in the class yesterday that uh this + + + align:start position:0% +in the class yesterday that uh this +issue here raised some questions + + align:start position:0% +issue here raised some questions + + + align:start position:0% +issue here raised some questions +the students wanted to know how + + align:start position:0% +the students wanted to know how + + + align:start position:0% +the students wanted to know how +the student phrased the question + + align:start position:0% +the student phrased the question + + + align:start position:0% +the student phrased the question +what ethical problems do faculty have + + align:start position:0% + + + + align:start position:0% + +i said well if even if we put aside + + align:start position:0% +i said well if even if we put aside + + + align:start position:0% +i said well if even if we put aside +questions that + + align:start position:0% +questions that + + + align:start position:0% +questions that +ethical issues that faculty have with + + align:start position:0% +ethical issues that faculty have with + + + align:start position:0% +ethical issues that faculty have with +students + + align:start position:0% +students + + + align:start position:0% +students +we have a lot of ethical issues among + + align:start position:0% +we have a lot of ethical issues among + + + align:start position:0% +we have a lot of ethical issues among +ourselves and the biggest one probably i + + align:start position:0% +ourselves and the biggest one probably i + + + align:start position:0% +ourselves and the biggest one probably i +don't know what you think about it + + align:start position:0% +don't know what you think about it + + + align:start position:0% +don't know what you think about it +our faculty members here but it's + + align:start position:0% +our faculty members here but it's + + + align:start position:0% +our faculty members here but it's +plagiarism + + align:start position:0% +plagiarism + + + align:start position:0% +plagiarism +that is the nightmare for us for one + + align:start position:0% +that is the nightmare for us for one + + + align:start position:0% +that is the nightmare for us for one +faculty member to plagiarize another one + + align:start position:0% +faculty member to plagiarize another one + + + align:start position:0% +faculty member to plagiarize another one +and that becomes uh a matter of + + align:start position:0% +and that becomes uh a matter of + + + align:start position:0% +and that becomes uh a matter of +irritation for students too + + align:start position:0% +irritation for students too + + + align:start position:0% +irritation for students too +but i think the big issue for students + + align:start position:0% +but i think the big issue for students + + + align:start position:0% +but i think the big issue for students +in plagiarism + + align:start position:0% +in 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+and you just before you go in for your + + + align:start position:0% +and you just before you go in for your +defense you find out that the data is + + align:start position:0% +defense you find out that the data is + + + align:start position:0% +defense you find out that the data is +corrupt + + align:start position:0% +corrupt + + + align:start position:0% +corrupt +what would you do in this situation the + + align:start position:0% +what would you do in this situation the + + + align:start position:0% +what would you do in this situation the +committee's sitting there saying well + + align:start position:0% +committee's sitting there saying well + + + align:start position:0% +committee's sitting there saying well +look we know it wasn't your fault + + align:start position:0% +look we know it wasn't your fault + + + align:start position:0% +look we know it wasn't your fault +we can't pass this thing + + align:start position:0% + + + + align:start position:0% + +all right so that can 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philosophers +uh some were there were some engineers + + align:start position:0% +uh some were there were some engineers + + + align:start position:0% +uh some were there were some engineers +involved + + align:start position:0% +involved + + + align:start position:0% +involved +and one of the big hopes as we will see + + align:start position:0% +and one of the big hopes as we will see + + + align:start position:0% +and one of the big hopes as we will see +in just a minute + + align:start position:0% +in just a minute + + + align:start position:0% +in just a minute +uh for the philosophers was that this + + align:start position:0% +uh for the philosophers was that this + + + align:start position:0% +uh for the philosophers was that this +was now an opportunity they thought + + align:start position:0% + + + + align:start position:0% + +to put their names uh in the history of + + align:start position:0% +to put their names uh in the history of + + + align:start position:0% +to put their 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we could borrow from + + align:start position:0% +uh that we could borrow from + + + align:start position:0% +uh that we could borrow from +united states law + + align:start position:0% +united states law + + + align:start position:0% +united states law +which provides that an organization + + align:start position:0% +which provides that an organization + + + align:start position:0% +which provides that an organization +particularly a corporation + + align:start position:0% +particularly a corporation + + + align:start position:0% +particularly a corporation +has personhood in law can commit a crime + + align:start position:0% +has personhood in law can commit a crime + + + align:start position:0% +has personhood in law can commit a crime +and can be punished for the crime + + align:start position:0% +and can be punished for the crime + + + align:start position:0% +and can be punished for the crime +independently of the people in the + + align:start position:0% +independently of the 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align:start position:0% +moral agents + + + align:start position:0% +moral agents +because there is no way that you can + + align:start position:0% +because there is no way that you can + + + align:start position:0% +because there is no way that you can +assign to them + + align:start position:0% +assign to them + + + align:start position:0% +assign to them +uh + + align:start position:0% +uh + + + align:start position:0% +uh +feelings + + align:start position:0% + + + + align:start position:0% + +moral + + align:start position:0% +moral + + + align:start position:0% +moral +impulses + + align:start position:0% +impulses + + + align:start position:0% +impulses +they cannot and a corporation cannot + + align:start position:0% +they cannot and a corporation cannot + + + align:start position:0% +they cannot and a corporation cannot +care about you + + align:start position:0% +care about you + + + align:start position:0% +care about you +so you cannot hold it responsible + + align:start position:0% +so you cannot hold it responsible + + + align:start position:0% +so you cannot hold it responsible +it has a will + + align:start position:0% + + + + align:start position:0% + +but it does not have an effort + + align:start position:0% +but it does not have an effort + + + align:start position:0% +but it does not have an effort +well that killed + + align:start position:0% +well that killed + + + align:start position:0% +well that killed +dash the hopes of a lot of people for a + + align:start position:0% +dash the hopes of a lot of people for a + + + align:start position:0% +dash the hopes of a lot of people for a +long time + + align:start position:0% +long time + + + align:start position:0% +long time +uh but we had quite a renowned visitor + + align:start position:0% +uh but we had quite a renowned visitor + + + align:start position:0% +uh but we had quite a renowned visitor +in class + + align:start position:0% +in class + + + align:start position:0% +in class +uh + + align:start position:0% +uh + + + align:start position:0% +uh +what about two weeks ago + + align:start position:0% +what about two weeks ago + + + align:start position:0% +what about two weeks ago +a week or so ago + + align:start position:0% +a week or so ago + + + align:start position:0% +a week or so ago +uh + + align:start position:0% +uh + + + align:start position:0% +uh +who affirmed what many people affirm + + align:start position:0% +who affirmed what many people affirm + + + align:start position:0% +who affirmed what many people affirm +and that is that + + align:start position:0% +and that is that + + + align:start position:0% +and that is that +we just cannot + + align:start position:0% +we just cannot + + + align:start position:0% +we just cannot +throw away our sentiment + + align:start position:0% +throw away our sentiment + + + align:start position:0% +throw away our sentiment +that organizations some of them do + + align:start position:0% +that organizations some of 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position:0% +when michelangelo was painting the + + + align:start position:0% +when michelangelo was painting the +sistine chapel same time same place + + align:start position:0% +sistine chapel same time same place + + + align:start position:0% +sistine chapel same time same place +different buildings + + align:start position:0% +different buildings + + + align:start position:0% +different buildings +uh that there was a place for greek + + align:start position:0% +uh that there was a place for greek + + + align:start position:0% +uh that there was a place for greek +thought in the western world + + align:start position:0% +thought in the western world + + + align:start position:0% +thought in the western world +and out of this thought we get + + align:start position:0% +and out of this thought we get + + + align:start position:0% +and out of this thought we get +two + + align:start position:0% +two + + + align:start position:0% +two +traditions in ethics + + align:start position:0% + + + + align:start position:0% + +one of them + + align:start position:0% +one of them + + + align:start position:0% +one of them +comes from aristotle + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +aristotle's tradition + + align:start position:0% + + + + align:start position:0% + +is a tradition + + align:start position:0% +is a tradition + + + align:start position:0% +is a tradition +that + + align:start position:0% + + + + align:start position:0% + +approaches ethics + + align:start position:0% +approaches ethics + + + align:start position:0% +approaches ethics +from a rational point of view + + align:start position:0% +from a rational point of view + + + align:start position:0% +from a rational point of view +that is to say we can use reason + + align:start position:0% +that is to say we can use reason + + + align:start position:0% +that is to say we can use reason +sometimes informed + + align:start position:0% +sometimes informed + + + align:start position:0% +sometimes informed +by facts + + align:start position:0% +by facts + + + align:start position:0% +by facts +decide right and wrong action good and + + align:start position:0% +decide right and wrong action good and + + + align:start position:0% +decide right and wrong action good and +bad behavior + + align:start position:0% + + + + align:start position:0% + +that's the aristotelian + + align:start position:0% + + + + align:start position:0% + +tradition + + align:start position:0% + + + + align:start position:0% + +and that is based as i said on reason + + align:start position:0% + + + + align:start position:0% + +and out of that tradition we get two + + align:start position:0% + + + + align:start position:0% + +other traditions + + align:start position:0% +other traditions + + + align:start position:0% +other traditions +one is that + + align:start position:0% + + + + align:start position:0% + +an ethical situ an ethical problem can + + align:start position:0% +an ethical situ an ethical problem can + + + align:start position:0% +an ethical situ an ethical problem can +be decided + + align:start position:0% +be decided + + + align:start position:0% +be decided +purely + + align:start position:0% + + + + align:start position:0% + +on logic + + align:start position:0% + + + + align:start position:0% + +and we have thanks to + + align:start position:0% +and we have thanks to + + + align:start position:0% +and we have thanks to +emmanuel kant + + align:start position:0% + + + + align:start position:0% + +for + + align:start position:0% +for + + + align:start position:0% +for +giving us + + align:start position:0% +giving us + + + align:start position:0% +giving us +that approach + + align:start position:0% +that approach + + + align:start position:0% +that approach +that is to say that a thing + + align:start position:0% +that is to say that a thing + + + align:start position:0% +that is to say that a thing +an act can be determined right or wrong + + align:start position:0% +an act can be determined right or wrong + + + align:start position:0% +an act can be determined right or wrong +or a + + align:start position:0% +or a + + + align:start position:0% +or a +thing can be determined good or bad + + align:start position:0% +thing can be determined good or bad + + + align:start position:0% +thing can be determined good or bad +based on principles + + align:start position:0% + + + + align:start position:0% + +and for him first principles were + + align:start position:0% +and for him first principles were + + + align:start position:0% +and for him first principles were +principles of logic + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +that gives us one great tradition that + + align:start position:0% + + + + align:start position:0% + +still holds with us today + + align:start position:0% +still holds with us today + + + align:start position:0% +still holds with us today +the other one + + align:start position:0% + + + + align:start position:0% + +is empirical + + align:start position:0% +is empirical + + + align:start position:0% +is empirical +and it says that if an action can be + + align:start position:0% +and it says that if an action can be + + + align:start position:0% +and it says that if an action can be +judged good or bad right or wrong + + align:start position:0% +judged good or bad right or wrong + + + align:start position:0% +judged good or bad right or wrong +depending on + + align:start position:0% + + + + align:start position:0% + +the happiness that it tends + + align:start position:0% +the happiness that it tends + + + align:start position:0% +the happiness that it tends +to either give people or take from + + align:start position:0% +to either give people or take from + + + align:start position:0% +to either give people or take from +people + + align:start position:0% +people + + + align:start position:0% +people +as a result of the action + + align:start position:0% +as a result of the action + + + align:start position:0% +as a result of the action +so it's factual + + align:start position:0% +so it's factual + + + align:start position:0% +so it's factual +and we have + + align:start position:0% +and we have + + + align:start position:0% +and we have +probably john stuart mill + + align:start position:0% + + + + align:start position:0% + +not who originated this point of view + + align:start position:0% +not who originated this point of view + + + align:start position:0% +not who originated this point of view +but + + align:start position:0% +but + + + align:start position:0% +but +who + + align:start position:0% +who + + + align:start position:0% +who +pretty much did more than anybody else i + + align:start position:0% +pretty much did more than anybody else i + + + align:start position:0% +pretty much did more than anybody else i +think to perfect it + + align:start position:0% +think to perfect it + + + align:start position:0% +think to perfect it +frankly i think that jeremy bentham is + + align:start position:0% +frankly i think that jeremy bentham is + + + align:start position:0% +frankly i think that jeremy bentham is +the person + + align:start position:0% +the person + + + align:start position:0% +the person +that um + + align:start position:0% +that um + + + align:start position:0% +that um +made the greatest contribution because + + align:start position:0% +made the greatest contribution because + + + align:start position:0% +made the greatest contribution because +he saw it as a solution to a political + + align:start position:0% +he saw it as a solution to a political + + + align:start position:0% +he saw it as a solution to a political +problem not so much a political problem + + align:start position:0% +problem not so much a political problem + + + align:start position:0% +problem not so much a political problem +but a problem of political science he + + align:start position:0% +but a problem of political science he + + + align:start position:0% +but a problem of political science he +was trying to really + + align:start position:0% +was trying to really + + + align:start position:0% +was trying to really +organize um + + align:start position:0% +organize um + + + align:start position:0% +organize um +thinking about how to build a british + + align:start position:0% +thinking about how to build a british + + + align:start position:0% +thinking about how to build a british +society but nevertheless mill got worked + + align:start position:0% +society but nevertheless mill got worked + + + align:start position:0% +society but nevertheless mill got worked +out all of the kinks + + align:start position:0% +out all of the kinks + + + align:start position:0% +out all of the kinks +and when i say all of the kinks you know + + align:start position:0% +and when i say all of the kinks you know + + + align:start position:0% +and when i say all of the kinks you know +what i mean by that the major ones we + + align:start position:0% +what i mean by that the major ones we + + + align:start position:0% +what i mean by that the major ones we +can still write a dissertation on on + + align:start position:0% +can still write a dissertation on on + + + align:start position:0% +can still write a dissertation on on +this stuff + + align:start position:0% +this stuff + + + align:start position:0% +this stuff +but uh he's the one that's gonna that's + + align:start position:0% +but uh he's the one that's gonna that's + + + align:start position:0% +but uh he's the one that's gonna that's +been remembered mostly for that + + align:start position:0% +been remembered mostly for that + + + align:start position:0% +been remembered mostly for that +um + + align:start position:0% +um + + + align:start position:0% +um +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +there is another tradition + + align:start position:0% + + + + align:start position:0% + +that we have + + align:start position:0% + + + + align:start position:0% + +in so far as greek antiquity is + + align:start position:0% +in so far as greek antiquity is + + + align:start position:0% +in so far as greek antiquity is +concerned + + align:start position:0% + + + + align:start position:0% + +that uh has given us to uh given to us + + align:start position:0% +that uh has given us to uh given to us + + + align:start position:0% +that uh has given us to uh given to us +by plato + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +plato's tradition is + + align:start position:0% +plato's tradition is + + + align:start position:0% +plato's tradition is +that really what good what is good and + + align:start position:0% +that really what good what is good and + + + align:start position:0% +that really what good what is good and +bad what is right and wrong is + + align:start position:0% +bad what is right and wrong is + + + align:start position:0% +bad what is right and wrong is +determined by + + align:start position:0% + + + + align:start position:0% + +character + + align:start position:0% + + + + align:start position:0% + +there are certain people who are good + + align:start position:0% +there are certain people who are good + + + align:start position:0% +there are certain people who are good +people there are certain people he would + + align:start position:0% +people there are certain people he would + + + align:start position:0% +people there are certain people he would +say are bad people + + align:start position:0% +say are bad people + + + align:start position:0% +say are bad people +and what he would say makes the + + align:start position:0% +and what he would say makes the + + + align:start position:0% +and what he would say makes the +difference between a good person + + align:start position:0% +difference between a good person + + + align:start position:0% +difference between a good person +a bad person and an ordinary person or + + align:start position:0% +a bad person and an ordinary person or + + + align:start position:0% +a bad person and an ordinary person or +what he calls the possession of virtues + + align:start position:0% + + + + align:start position:0% + +and he cannot articulate those virtues + + align:start position:0% +and he cannot articulate those virtues + + + align:start position:0% +and he cannot articulate those virtues +uh + + align:start position:0% +uh + + + align:start position:0% +uh +which means that as we come into + + align:start position:0% +which means that as we come into + + + align:start position:0% +which means that as we come into +different cultures we can articulate + + align:start position:0% +different cultures we can articulate + + + align:start position:0% +different cultures we can articulate +different virtues but nevertheless + + align:start position:0% +different virtues but nevertheless + + + align:start position:0% +different virtues but nevertheless +it's the notion that we're talking about + + align:start position:0% +it's the notion that we're talking about + + + align:start position:0% +it's the notion that we're talking about +good character + + align:start position:0% +good character + + + align:start position:0% +good character +and he got his virtues from + + align:start position:0% +and he got his virtues from + + + align:start position:0% +and he got his virtues from +uh the kind of society that he came from + + align:start position:0% +uh the kind of society that he came from + + + align:start position:0% +uh the kind of society that he came from +and though that side it was a warrior + + align:start position:0% +and though that side it was a warrior + + + align:start position:0% +and though that side it was a warrior +society basically and so good virtues + + align:start position:0% +society basically and so good virtues + + + align:start position:0% +society basically and so good virtues +meant good + + align:start position:0% +meant good + + + align:start position:0% +meant good +warrior virgins heroic + + align:start position:0% +warrior virgins heroic + + + align:start position:0% +warrior virgins heroic +virtues + + align:start position:0% +virtues + + + align:start position:0% +virtues +now out of that in the united states + + align:start position:0% + + + + align:start position:0% + +and here's a point that we have not + + align:start position:0% +and here's a point that we have not + + + align:start position:0% +and here's a point that we have not +covered in class but it's an opportunity + + align:start position:0% +covered in class but it's an opportunity + + + align:start position:0% +covered in class but it's an opportunity +for me to cover to cover it in class + + align:start position:0% +for me to cover to cover it in class + + + align:start position:0% +for me to cover to cover it in class +uh in the united states + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% + + + + align:start position:0% + +since + + align:start position:0% + + + + align:start position:0% + +let me put down a number you see tell me + + align:start position:0% +let me put down a number you see tell me + + + align:start position:0% +let me put down a number you see tell me +if you can correct this number + + align:start position:0% + + + + align:start position:0% + +in the united states since about 1650 + + align:start position:0% +in the united states since about 1650 + + + align:start position:0% +in the united states since about 1650 +there was + + align:start position:0% +there was + + + align:start position:0% +there was +in the universities + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +a concept called classical education do + + align:start position:0% +a concept called classical education do + + + align:start position:0% +a concept called classical education do +you know what number i'm looking for + + align:start position:0% + + + + align:start position:0% + +when the first university united states + + align:start position:0% +when the first university united states + + + align:start position:0% +when the first university united states +was founded well first of all do you + + align:start position:0% +was founded well first of all do you + + + align:start position:0% +was founded well first of all do you +know which university that was + + align:start position:0% + + + + align:start position:0% + +harvard + + align:start position:0% +harvard + + + align:start position:0% +harvard +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +right down the street + + align:start position:0% +right down the street + + + align:start position:0% +right down the street +it was 16 something + + align:start position:0% +it was 16 something + + + align:start position:0% +it was 16 something +you remember + + align:start position:0% +you remember + + + align:start position:0% +you remember +i don't remember the exact date but it + + align:start position:0% +i don't remember the exact date but it + + + align:start position:0% +i don't remember the exact date but it +was after i remember this much it was + + align:start position:0% +was after i remember this much it was + + + align:start position:0% +was after i remember this much it was +after 1620 when the pilgrims landed + + align:start position:0% +after 1620 when the pilgrims landed + + + align:start position:0% +after 1620 when the pilgrims landed +and i remember it was 16 something okay + + align:start position:0% +and i remember it was 16 something okay + + + align:start position:0% +and i remember it was 16 something okay +now classical education + + align:start position:0% + + + + align:start position:0% + +was education for + + align:start position:0% +was education for + + + align:start position:0% +was education for +the clergy + + align:start position:0% +the clergy + + + align:start position:0% +the clergy +and for + + align:start position:0% +and for + + + align:start position:0% +and for +the aristocratic class + + align:start position:0% + + + + align:start position:0% + +and the idea was + + align:start position:0% +and the idea was + + + align:start position:0% +and the idea was +that + + align:start position:0% +that + + + align:start position:0% +that +what a person needed from a college + + align:start position:0% +what a person needed from a college + + + align:start position:0% +what a person needed from a college +education what these people needed from + + align:start position:0% +education what these people needed from + + + align:start position:0% +education what these people needed from +a college education + + align:start position:0% +a college education + + + align:start position:0% +a college education +was + + align:start position:0% +was + + + align:start position:0% +was +good character + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +that the virtues of good character were + + align:start position:0% +that the virtues of good character were + + + align:start position:0% +that the virtues of good character were +spelled out in christian religion + + align:start position:0% + + + + align:start position:0% + +and that the textbooks the curriculum + + align:start position:0% +and that the textbooks the curriculum + + + align:start position:0% +and that the textbooks the curriculum +was taken from greek antiquity + + align:start position:0% + + + + align:start position:0% + +trivium quadrillion + + align:start position:0% +trivium quadrillion + + + align:start position:0% +trivium quadrillion +classical studies in philosophy + + align:start position:0% +classical studies in philosophy + + + align:start position:0% +classical studies in philosophy +mathematics + + align:start position:0% + + + + align:start position:0% + +science + + align:start position:0% +science + + + align:start position:0% +science +um + + align:start position:0% +um + + + align:start position:0% +um +rhetoric + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% +um + + + align:start position:0% +um +dialectic + + align:start position:0% +dialectic + + + align:start position:0% +dialectic +and + + align:start position:0% +and + + + align:start position:0% +and +literature + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +now i have some mem some numbers i've + + align:start position:0% +now i have some mem some numbers i've + + + align:start position:0% +now i have some mem some numbers i've +committed to memory i uh trust my num my + + align:start position:0% +committed to memory i uh trust my num my + + + align:start position:0% +committed to memory i uh trust my num my +my my memory on these numbers + + align:start position:0% +my my memory on these numbers + + + align:start position:0% +my my memory on these numbers +but that doesn't mean i'm going to ask + + align:start position:0% +but that doesn't mean i'm going to ask + + + align:start position:0% +but that doesn't mean i'm going to ask +you to trust these numbers + + align:start position:0% +you to trust these numbers + + + align:start position:0% +you to trust these numbers +so as a matter of fact i'm going to ask + + align:start position:0% +so as a matter of fact i'm going to ask + + + align:start position:0% +so as a matter of fact i'm going to ask +you to look them up but i have some + + align:start position:0% +you to look them up but i have some + + + align:start position:0% +you to look them up but i have some +other figures some other numbers + + align:start position:0% + + + + align:start position:0% + +before the civil war before 1861 + + align:start position:0% + + + + align:start position:0% + +there were 350 universities in the + + align:start position:0% +there were 350 universities in the + + + align:start position:0% +there were 350 universities in the +united states + + align:start position:0% + + + + align:start position:0% + +it got up to about 350. + + align:start position:0% +it got up to about 350. + + + align:start position:0% +it got up to about 350. +now some + + align:start position:0% +now some + + + align:start position:0% +now some +had + + align:start position:0% +had + + + align:start position:0% +had +closed their doors there were new ones + + align:start position:0% +closed their doors there were new ones + + + align:start position:0% +closed their doors there were new ones +that came in but there were about 350 of + + align:start position:0% +that came in but there were about 350 of + + + align:start position:0% +that came in but there were about 350 of +them + + align:start position:0% + + + + align:start position:0% + +11 out of 12 of those universities + + align:start position:0% +11 out of 12 of those universities + + + align:start position:0% +11 out of 12 of those universities +over the entire periods of their + + align:start position:0% +over the entire periods of their + + + align:start position:0% +over the entire periods of their +existence + + align:start position:0% +existence + + + align:start position:0% +existence +up until + + align:start position:0% +up until + + + align:start position:0% +up until +the civil war + + align:start position:0% +the civil war + + + align:start position:0% +the civil war +11 out of 12 presidents were + + align:start position:0% +11 out of 12 presidents were + + + align:start position:0% +11 out of 12 presidents were +clergymen + + align:start position:0% + + + + align:start position:0% + +and many of the ones who were not clergy + + align:start position:0% + + + + align:start position:0% + +had studied for the ministry but decided + + align:start position:0% +had studied for the ministry but decided + + + align:start position:0% +had studied for the ministry but decided +either to go to law or otherwise not get + + align:start position:0% +either to go to law or otherwise not get + + + align:start position:0% +either to go to law or otherwise not get +ordained + + align:start position:0% + + + + align:start position:0% + +in 1833 + + align:start position:0% + + + + align:start position:0% + +a man by the name of john quincy + + align:start position:0% + + + + align:start position:0% + +not to be confused with john quincy + + align:start position:0% +not to be confused with john quincy + + + align:start position:0% +not to be confused with john quincy +adams + + align:start position:0% +adams + + + align:start position:0% +adams +but i think was a relative of john + + align:start position:0% +but i think was a relative of john + + + align:start position:0% +but i think was a relative of john +quincy adams + + align:start position:0% +quincy adams + + + align:start position:0% +quincy adams +a man by the name of john quincy became + + align:start position:0% +a man by the name of john quincy became + + + align:start position:0% +a man by the name of john quincy became +pres became president of harvard + + align:start position:0% + + + + align:start position:0% + +and john quincy said + + align:start position:0% +and john quincy said + + + align:start position:0% +and john quincy said +his program is to get rid of classical + + align:start position:0% +his program is to get rid of classical + + + align:start position:0% +his program is to get rid of classical +education + + align:start position:0% + + + + align:start position:0% + +he was not + + align:start position:0% +he was not + + + align:start position:0% +he was not +a clergyman + + align:start position:0% +a clergyman + + + align:start position:0% +a clergyman +he was one of the first clergyman to + + align:start position:0% +he was one of the first clergyman to + + + align:start position:0% +he was one of the first clergyman to +become president of the university of + + align:start position:0% +become president of the university of + + + align:start position:0% +become president of the university of +the united states + + align:start position:0% +the united states + + + align:start position:0% +the united states +who was not a clergyman at all + + align:start position:0% +who was not a clergyman at all + + + align:start position:0% +who was not a clergyman at all +and i mean at all in any of his training + + align:start position:0% +and i mean at all in any of his training + + + align:start position:0% +and i mean at all in any of his training +okay + + align:start position:0% +okay + + + align:start position:0% +okay +now why did he want to get rid of + + align:start position:0% +now why did he want to get rid of + + + align:start position:0% +now why did he want to get rid of +classical education and what did he want + + align:start position:0% +classical education and what did he want + + + align:start position:0% +classical education and what did he want +to want to want to replace it with and + + align:start position:0% +to want to want to replace it with and + + + align:start position:0% +to want to want to replace it with and +why + + align:start position:0% +why + + + align:start position:0% +why +um if you don't know + + align:start position:0% +um if you don't know + + + align:start position:0% +um if you don't know +your speculation is invited because you + + align:start position:0% +your speculation is invited because you + + + align:start position:0% +your speculation is invited because you +will probably be right + + align:start position:0% +will probably be right + + + align:start position:0% +will probably be right +we're talking about 1833 + + align:start position:0% + + + + align:start position:0% + +very beginning of the industrial + + align:start position:0% +very beginning of the industrial + + + align:start position:0% +very beginning of the industrial +revolution + + align:start position:0% + + + + align:start position:0% + +is classical education going to help you + + align:start position:0% +is classical education going to help you + + + align:start position:0% +is classical education going to help you +make a + + align:start position:0% +make a + + + align:start position:0% +make a +a plant + + align:start position:0% +a plant + + + align:start position:0% +a plant +no + + align:start position:0% +no + + + align:start position:0% +no +at least in his mind and apparently he + + align:start position:0% +at least in his mind and apparently he + + + align:start position:0% +at least in his mind and apparently he +was not alone + + align:start position:0% + + + + align:start position:0% + +so what would + + align:start position:0% +so what would + + + align:start position:0% +so what would +get the united states into the + + align:start position:0% +get the united states into the + + + align:start position:0% +get the united states into the +industrial revolution + + align:start position:0% +industrial revolution + + + align:start position:0% +industrial revolution +which had already started in in britain + + align:start position:0% +which had already started in in britain + + + align:start position:0% +which had already started in in britain +at that time + + align:start position:0% +at that time + + + align:start position:0% +at that time +when did it get on the continent + + align:start position:0% +when did it get on the continent + + + align:start position:0% +when did it get on the continent +before us i'm sure + + align:start position:0% + + + + align:start position:0% + +around that time turn this okay + + align:start position:0% +around that time turn this okay + + + align:start position:0% +around that time turn this okay +john quincy now here's where you have to + + align:start position:0% +john quincy now here's where you have to + + + align:start position:0% +john quincy now here's where you have to +when you read any of this stuff you have + + align:start position:0% +when you read any of this stuff you have + + + align:start position:0% +when you read any of this stuff you have +to you have to read between the lines on + + align:start position:0% +to you have to read between the lines on + + + align:start position:0% +to you have to read between the lines on +on some of the + + align:start position:0% +on some of the + + + align:start position:0% +on some of the +the words they use john quincy said + + align:start position:0% +the words they use john quincy said + + + align:start position:0% +the words they use john quincy said +science and mathematics + + align:start position:0% + + + + align:start position:0% + +okay so you can say well science and + + align:start position:0% +okay so you can say well science and + + + align:start position:0% +okay so you can say well science and +mathematics is already here + + align:start position:0% +mathematics is already here + + + align:start position:0% +mathematics is already here +john quincy meant applied science + + align:start position:0% +john quincy meant applied science + + + align:start position:0% +john quincy meant applied science +and applied mathematics + + align:start position:0% +and applied mathematics + + + align:start position:0% +and applied mathematics +and he did not + + align:start position:0% +and he did not + + + align:start position:0% +and he did not +use the word engineering at the + + align:start position:0% +use the word engineering at the + + + align:start position:0% +use the word engineering at the +beginning + + align:start position:0% +beginning + + + align:start position:0% +beginning +but that's who these people were they + + align:start position:0% +but that's who these people were they + + + align:start position:0% +but that's who these people were they +were engineers + + align:start position:0% +were engineers + + + align:start position:0% +were engineers +uh applied scientists and applied + + align:start position:0% +uh applied scientists and applied + + + align:start position:0% +uh applied scientists and applied +mathematicians that's what he thought we + + align:start position:0% +mathematicians that's what he thought we + + + align:start position:0% +mathematicians that's what he thought we +needed + + align:start position:0% + + + + align:start position:0% + +so a struggle + + align:start position:0% +so a struggle + + + align:start position:0% +so a struggle +ensued at that point + + align:start position:0% +ensued at that point + + + align:start position:0% +ensued at that point +that has not been + + align:start position:0% +that has not been + + + align:start position:0% +that has not been +resolved + + align:start position:0% +resolved + + + align:start position:0% +resolved +in the united states + + align:start position:0% +in the united states + + + align:start position:0% +in the united states +john quincy introduced + + align:start position:0% +john quincy introduced + + + align:start position:0% +john quincy introduced +a + + align:start position:0% +a + + + align:start position:0% +a +new curriculum + + align:start position:0% +new curriculum + + + align:start position:0% +new curriculum +that + + align:start position:0% +that + + + align:start position:0% +that +got a name + + align:start position:0% +got a name + + + align:start position:0% +got a name +a hundred years later + + align:start position:0% + + + + align:start position:0% + +okay i'll tell you what the name of it + + align:start position:0% +okay i'll tell you what the name of it + + + align:start position:0% +okay i'll tell you what the name of it +is + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% + + + + align:start position:0% + +pragmatism + + align:start position:0% + + + + align:start position:0% + +so it had went by different names it's + + align:start position:0% +so it had went by different names it's + + + align:start position:0% +so it had went by different names it's +still you can talk about + + align:start position:0% +still you can talk about + + + align:start position:0% +still you can talk about +the alternative to classical education + + align:start position:0% +the alternative to classical education + + + align:start position:0% +the alternative to classical education +being pragmatic + + align:start position:0% + + + + align:start position:0% + +uh + + align:start position:0% +uh + + + align:start position:0% +uh +scholars of education have different + + align:start position:0% +scholars of education have different + + + align:start position:0% +scholars of education have different +names but it's good for us in this class + + align:start position:0% +names but it's good for us in this class + + + align:start position:0% +names but it's good for us in this class +to use the philosophical name because we + + align:start position:0% +to use the philosophical name because we + + + align:start position:0% +to use the philosophical name because we +can now associate that with a person + + align:start position:0% + + + + align:start position:0% + +john dewey + + align:start position:0% + + + + align:start position:0% + +okay now what was the nature of this + + align:start position:0% +okay now what was the nature of this + + + align:start position:0% +okay now what was the nature of this +why do you think people would do battle + + align:start position:0% +why do you think people would do battle + + + align:start position:0% +why do you think people would do battle +over + + align:start position:0% + + + + align:start position:0% + +replacing the curriculum + + align:start position:0% +replacing the curriculum + + + align:start position:0% +replacing the curriculum +replacing classical education + + align:start position:0% +replacing classical education + + + align:start position:0% +replacing classical education +let's think of all of the reasons well + + align:start position:0% +let's think of all of the reasons well + + + align:start position:0% +let's think of all of the reasons well +one of them starts out means that + + align:start position:0% +one of them starts out means that + + + align:start position:0% +one of them starts out means that +the + + align:start position:0% +the + + + align:start position:0% +the +the + + align:start position:0% +the + + + align:start position:0% +the +religious institutions have funded a + + align:start position:0% +religious institutions have funded a + + + align:start position:0% +religious institutions have funded a +whole lot of colleges + + align:start position:0% + + + + align:start position:0% + +yes + + align:start position:0% +yes + + + align:start position:0% +yes +and if not anti-religious dir definitely + + align:start position:0% +and if not anti-religious dir definitely + + + align:start position:0% +and if not anti-religious dir definitely +anti-religious people + + align:start position:0% +anti-religious people + + + align:start position:0% +anti-religious people +or better stated + + align:start position:0% +or better stated + + + align:start position:0% +or better stated +anti-religious control + + align:start position:0% + + + + align:start position:0% + +right + + align:start position:0% + + + + align:start position:0% + +and if you go to the midwest today + + align:start position:0% +and if you go to the midwest today + + + align:start position:0% +and if you go to the midwest today +you see much of the same arguments + + align:start position:0% + + + + align:start position:0% + +about schools + + align:start position:0% +about schools + + + align:start position:0% +about schools +today + + align:start position:0% + + + + align:start position:0% + +well what happened was the the main + + align:start position:0% +well what happened was the the main + + + align:start position:0% +well what happened was the the main +reason i'm bringing this up and i'm + + align:start position:0% +reason i'm bringing this up and i'm + + + align:start position:0% +reason i'm bringing this up and i'm +still going to go back and do some more + + align:start position:0% +still going to go back and do some more + + + align:start position:0% +still going to go back and do some more +history i'm still going to require you + + align:start position:0% +history i'm still going to require you + + + align:start position:0% +history i'm still going to require you +to get these numbers right i'm still + + align:start position:0% +to get these numbers right i'm still + + + align:start position:0% +to get these numbers right i'm still +going to require you to say when you've + + align:start position:0% +going to require you to say when you've + + + align:start position:0% +going to require you to say when you've +got the numbers right to bring the right + + align:start position:0% +got the numbers right to bring the right + + + align:start position:0% +got the numbers right to bring the right +numbers back to class + + align:start position:0% +numbers back to class + + + align:start position:0% +numbers back to class +okay but nevertheless uh i'm gonna trust + + align:start position:0% +okay but nevertheless uh i'm gonna trust + + + align:start position:0% +okay but nevertheless uh i'm gonna trust +my memory um for right now um + + align:start position:0% +my memory um for right now um + + + align:start position:0% +my memory um for right now um +no the main reason for bringing this up + + align:start position:0% +no the main reason for bringing this up + + + align:start position:0% +no the main reason for bringing this up +is + + align:start position:0% + + + + align:start position:0% + +that + + align:start position:0% +that + + + align:start position:0% +that +character + + align:start position:0% +character + + + align:start position:0% +character +this whole platonic tradition + + align:start position:0% +this whole platonic tradition + + + align:start position:0% +this whole platonic tradition +got wiped out in the united states + + align:start position:0% + + + + align:start position:0% + +we never replaced it if we had religious + + align:start position:0% +we never replaced it if we had religious + + + align:start position:0% +we never replaced it if we had religious +character at first could we have another + + align:start position:0% +character at first could we have another + + + align:start position:0% +character at first could we have another +kind of character + + align:start position:0% +kind of character + + + align:start position:0% +kind of character +it never was replaced + + align:start position:0% +it never was replaced + + + align:start position:0% +it never was replaced +okay now that's the reason i'm bringing + + align:start position:0% +okay now that's the reason i'm bringing + + + align:start position:0% +okay now that's the reason i'm bringing +it up + + align:start position:0% +it up + + + align:start position:0% +it up +that plato got wiped out + + align:start position:0% +that plato got wiped out + + + align:start position:0% +that plato got wiped out +and in the end i'm going to say plato's + + align:start position:0% +and in the end i'm going to say plato's + + + align:start position:0% +and in the end i'm going to say plato's +got to be brought back + + align:start position:0% +got to be brought back + + + align:start position:0% +got to be brought back +all right so i'm going to give you my + + align:start position:0% +all right so i'm going to give you my + + + align:start position:0% +all right so i'm going to give you my +thesis on it you don't have to + + align:start position:0% +thesis on it you don't have to + + + align:start position:0% +thesis on it you don't have to +adopt my thesis on it + + align:start position:0% +adopt my thesis on it + + + align:start position:0% +adopt my thesis on it +but if you don't adopt my thesis on it + + align:start position:0% +but if you don't adopt my thesis on it + + + align:start position:0% +but if you don't adopt my thesis on it +you've got two responsibilities number + + align:start position:0% +you've got two responsibilities number + + + align:start position:0% +you've got two responsibilities number +one tell me what + + align:start position:0% +one tell me what + + + align:start position:0% +one tell me what +thesis you do adopt and number two + + align:start position:0% +thesis you do adopt and number two + + + align:start position:0% +thesis you do adopt and number two +give me your justification + + align:start position:0% +give me your justification + + + align:start position:0% +give me your justification +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so um + + align:start position:0% +so um + + + align:start position:0% +so um +but the but the fact is that we just + + align:start position:0% +but the but the fact is that we just + + + align:start position:0% +but the but the fact is that we just +won't see this tradition + + align:start position:0% +won't see this tradition + + + align:start position:0% +won't see this tradition +in the united states after the civil war + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +uh we have what's called the scopes + + align:start position:0% +uh we have what's called the scopes + + + align:start position:0% +uh we have what's called the scopes +trial + + align:start position:0% +trial + + + align:start position:0% +trial +in the united states + + align:start position:0% + + + + align:start position:0% + +where a school teacher this was in the + + align:start position:0% +where a school teacher this was in the + + + align:start position:0% +where a school teacher this was in the +1920s + + align:start position:0% +1920s + + + align:start position:0% +1920s +was put on trial + + align:start position:0% +was put on trial + + + align:start position:0% +was put on trial +for teaching creationism in the class + + align:start position:0% + + + + align:start position:0% + +and it had + + align:start position:0% +and it had + + + align:start position:0% +and it had +evolution + + align:start position:0% +evolution + + + align:start position:0% +evolution +i said creationism i didn't mean to + + align:start position:0% +i said creationism i didn't mean to + + + align:start position:0% +i said creationism i didn't mean to +sacrifice i meant to say evolution it + + align:start position:0% +sacrifice i meant to say evolution it + + + align:start position:0% +sacrifice i meant to say evolution it +was against creationism + + align:start position:0% +was against creationism + + + align:start position:0% +was against creationism +uh in the in the classroom it became + + align:start position:0% +uh in the in the classroom it became + + + align:start position:0% +uh in the in the classroom it became +national news and became a big they made + + align:start position:0% +national news and became a big they made + + + align:start position:0% +national news and became a big they made +movies out of it + + align:start position:0% +movies out of it + + + align:start position:0% +movies out of it +uh + + align:start position:0% +uh + + + align:start position:0% +uh +so uh this this battle continues can you + + align:start position:0% +so uh this this battle continues can you + + + align:start position:0% +so uh this this battle continues can you +think of any other reasons + + align:start position:0% +think of any other reasons + + + align:start position:0% +think of any other reasons +that people would want to fight over + + align:start position:0% +that people would want to fight over + + + align:start position:0% +that people would want to fight over +this + + align:start position:0% + + + + align:start position:0% + +clearly + + align:start position:0% + + + + align:start position:0% + +john dewey said why have + + align:start position:0% +john dewey said why have + + + align:start position:0% +john dewey said why have +john dewey said why i have education + + align:start position:0% +john dewey said why i have education + + + align:start position:0% +john dewey said why i have education +just for the aristocrats and the + + align:start position:0% +just for the aristocrats and the + + + align:start position:0% +just for the aristocrats and the +preachers + + align:start position:0% +preachers + + + align:start position:0% +preachers +why not the poor people + + align:start position:0% + + + + align:start position:0% + +right + + align:start position:0% +right + + + align:start position:0% +right +right + + align:start position:0% +right + + + align:start position:0% +right +it was threatening to them in many ways + + align:start position:0% +it was threatening to them in many ways + + + align:start position:0% +it was threatening to them in many ways +um + + align:start position:0% +um + + + align:start position:0% +um +uh can you imagine yourself an + + align:start position:0% +uh can you imagine yourself an + + + align:start position:0% +uh can you imagine yourself an +aristocrat in 1850 + + align:start position:0% +aristocrat in 1850 + + + align:start position:0% +aristocrat in 1850 +at harvard + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +there's some kid just coming off a farm + + align:start position:0% +there's some kid just coming off a farm + + + align:start position:0% +there's some kid just coming off a farm +from iowa + + align:start position:0% +from iowa + + + align:start position:0% +from iowa +coming to harvard + + align:start position:0% + + + + align:start position:0% + +not a fit + + align:start position:0% +not a fit + + + align:start position:0% +not a fit +you can see where somebody would object + + align:start position:0% +you can see where somebody would object + + + align:start position:0% +you can see where somebody would object +to that teachers students everybody + + align:start position:0% + + + + align:start position:0% + +okay so that there was a class issue + + align:start position:0% + + + + align:start position:0% + +and this whole thing filtered all the + + align:start position:0% +and this whole thing filtered all the + + + align:start position:0% +and this whole thing filtered all the +way down to first grade not just the + + align:start position:0% +way down to first grade not just the + + + align:start position:0% +way down to first grade not just the +colleges + + align:start position:0% + + + + align:start position:0% + +all right can you think of another issue + + align:start position:0% +all right can you think of another issue + + + align:start position:0% +all right can you think of another issue +any other issue i'll tell you one that's + + align:start position:0% +any other issue i'll tell you one that's + + + align:start position:0% +any other issue i'll tell you one that's +not that that actually it's sort of like + + align:start position:0% +not that that actually it's sort of like + + + align:start position:0% +not that that actually it's sort of like +the + + align:start position:0% +the + + + align:start position:0% +the +it's actually one that's sort of obvious + + align:start position:0% +it's actually one that's sort of obvious + + + align:start position:0% +it's actually one that's sort of obvious +when you think about it but you might + + align:start position:0% +when you think about it but you might + + + align:start position:0% +when you think about it but you might +not be motivated to think about it + + align:start position:0% + + + + align:start position:0% + +here's to me what turned out to be + + align:start position:0% + + + + align:start position:0% + +a + + align:start position:0% +a + + + align:start position:0% +a +battleground in the united states over + + align:start position:0% +battleground in the united states over + + + align:start position:0% +battleground in the united states over +these two forms of education + + align:start position:0% + + + + align:start position:0% + +that + + align:start position:0% + + + + align:start position:0% + +that + + align:start position:0% + + + + align:start position:0% + +i think was paramount + + align:start position:0% + + + + align:start position:0% + +and that was + + align:start position:0% +and that was + + + align:start position:0% +and that was +here's the question + + align:start position:0% +here's the question + + + align:start position:0% +here's the question +here is the question + + align:start position:0% + + + + align:start position:0% + +we've talked about means and ends + + align:start position:0% +we've talked about means and ends + + + align:start position:0% +we've talked about means and ends +we gave a name to it called teleology + + align:start position:0% + + + + align:start position:0% + +and the question is what is the end of + + align:start position:0% +and the question is what is the end of + + + align:start position:0% +and the question is what is the end of +education + + align:start position:0% +education + + + align:start position:0% +education +the state or the individual + + align:start position:0% + + + + align:start position:0% + +john dewey's end was the state + + align:start position:0% + + + + align:start position:0% + +classical education is the individual + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% + + + + align:start position:0% + +i see what you're saying this was a + + align:start position:0% +i see what you're saying this was a + + + align:start position:0% +i see what you're saying this was a +matter of open debate and it was a + + align:start position:0% +matter of open debate and it was a + + + align:start position:0% +matter of open debate and it was a +matter that dewey was charged with + + align:start position:0% +matter that dewey was charged with + + + align:start position:0% +matter that dewey was charged with +and + + align:start position:0% +and + + + align:start position:0% +and +dewey and i think it's fair to say that + + align:start position:0% +dewey and i think it's fair to say that + + + align:start position:0% +dewey and i think it's fair to say that +in his mind + + align:start position:0% +in his mind + + + align:start position:0% +in his mind +his greatest work + + align:start position:0% +his greatest work + + + align:start position:0% +his greatest work +was one of his later works we got plenty + + align:start position:0% +was one of his later works we got plenty + + + align:start position:0% +was one of his later works we got plenty +of time + + align:start position:0% +of time + + + align:start position:0% +of time +was one of his later works called + + align:start position:0% +was one of his later works called + + + align:start position:0% +was one of his later works called +democracy and education + + align:start position:0% +democracy and education + + + align:start position:0% +democracy and education +so dewey tried to defend himself + + align:start position:0% +so dewey tried to defend himself + + + align:start position:0% +so dewey tried to defend himself +against these claims of education for + + align:start position:0% +against these claims of education for + + + align:start position:0% +against these claims of education for +the state as a very as opposed to the + + align:start position:0% +the state as a very as opposed to the + + + align:start position:0% +the state as a very as opposed to the +individual + + align:start position:0% +individual + + + align:start position:0% +individual +all right + + align:start position:0% +all right + + + align:start position:0% +all right +i happen to take the position that that + + align:start position:0% +i happen to take the position that that + + + align:start position:0% +i happen to take the position that that +defense is not strong + + align:start position:0% + + + + align:start position:0% + +but i'm not but the point the point that + + align:start position:0% +but i'm not but the point the point that + + + align:start position:0% +but i'm not but the point the point that +i want to make that i think uh we all + + align:start position:0% +i want to make that i think uh we all + + + align:start position:0% +i want to make that i think uh we all +will agree on it and be able to see the + + align:start position:0% +will agree on it and be able to see the + + + align:start position:0% +will agree on it and be able to see the +justification that this was a + + align:start position:0% +justification that this was a + + + align:start position:0% +justification that this was a +point of debate + + align:start position:0% +point of debate + + + align:start position:0% +point of debate +there was a major point of debate and it + + align:start position:0% +there was a major point of debate and it + + + align:start position:0% +there was a major point of debate and it +continues + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +all right + + align:start position:0% +all right + + + align:start position:0% +all right +the classicist the cl the religious + + align:start position:0% +the classicist the cl the religious + + + align:start position:0% +the classicist the cl the religious +classes would say + + align:start position:0% +classes would say + + + align:start position:0% +classes would say +that the ideal for the state is in + + align:start position:0% +that the ideal for the state is in + + + align:start position:0% +that the ideal for the state is in +heaven + + align:start position:0% +heaven + + + align:start position:0% +heaven +more precisely that if you're if you're + + align:start position:0% +more precisely that if you're if you're + + + align:start position:0% +more precisely that if you're if you're +christian you're talking about the + + align:start position:0% +christian you're talking about the + + + align:start position:0% +christian you're talking about the +trinity + + align:start position:0% +trinity + + + align:start position:0% +trinity +that the relationship of god the father + + align:start position:0% +that the relationship of god the father + + + align:start position:0% +that the relationship of god the father +god the son god the holy spirit is the + + align:start position:0% +god the son god the holy spirit is the + + + align:start position:0% +god the son god the holy spirit is the +model for the family + + align:start position:0% +model for the family + + + align:start position:0% +model for the family +for government + + align:start position:0% +for government + + + align:start position:0% +for government +for the community for business + + align:start position:0% +for the community for business + + + align:start position:0% +for the community for business +all right that's what they would say + + align:start position:0% +all right that's what they would say + + + align:start position:0% +all right that's what they would say +so they said so they would say yes we + + align:start position:0% +so they said so they would say yes we + + + align:start position:0% +so they said so they would say yes we +are not just for the individual but + + align:start position:0% +are not just for the individual but + + + align:start position:0% +are not just for the individual but +we're for the state + + align:start position:0% +we're for the state + + + align:start position:0% +we're for the state +and + + align:start position:0% +and + + + align:start position:0% +and +john dewey and the others will say + + align:start position:0% +john dewey and the others will say + + + align:start position:0% +john dewey and the others will say +that argument doesn't sound strong + + align:start position:0% +that argument doesn't sound strong + + + align:start position:0% +that argument doesn't sound strong +coming from you all + + align:start position:0% + + + + align:start position:0% + +democracy is by definition as the greeks + + align:start position:0% +democracy is by definition as the greeks + + + align:start position:0% +democracy is by definition as the greeks +put it a community of free individuals + + align:start position:0% +put it a community of free individuals + + + align:start position:0% +put it a community of free individuals +the individual is the primacy in + + align:start position:0% +the individual is the primacy in + + + align:start position:0% +the individual is the primacy in +democracy + + align:start position:0% + + + + align:start position:0% + +so uh they so everybody said we're + + align:start position:0% +so uh they so everybody said we're + + + align:start position:0% +so uh they so everybody said we're +covering both bases and each side said + + align:start position:0% +covering both bases and each side said + + + align:start position:0% +covering both bases and each side said +you really aren't sincere about this + + align:start position:0% + + + + align:start position:0% + +all right + + align:start position:0% + + + + align:start position:0% + +in 1945 + + align:start position:0% + + + + align:start position:0% + +a very important book was published it + + align:start position:0% +a very important book was published it + + + align:start position:0% +a very important book was published it +was called + + align:start position:0% + + + + align:start position:0% + +general education in a free society + + align:start position:0% + + + + align:start position:0% + +now this book came out in 1945 that's + + align:start position:0% +now this book came out in 1945 that's + + + align:start position:0% +now this book came out in 1945 that's +auspicious + + align:start position:0% +auspicious + + + align:start position:0% +auspicious +second world world war ended + + align:start position:0% + + + + align:start position:0% + +the national science foundation was + + align:start position:0% +the national science foundation was + + + align:start position:0% +the national science foundation was +founded + + align:start position:0% + + + + align:start position:0% + +and it attempted + + align:start position:0% +and it attempted + + + align:start position:0% +and it attempted +general education and free society this + + align:start position:0% +general education and free society this + + + align:start position:0% +general education and free society this +book + + align:start position:0% +book + + + align:start position:0% +book +to make sense out of this debate + + align:start position:0% +to make sense out of this debate + + + align:start position:0% +to make sense out of this debate +classical versus + + align:start position:0% + + + + align:start position:0% + +pragmatic education + + align:start position:0% +pragmatic education + + + align:start position:0% +pragmatic education +tried to find a compromise + + align:start position:0% +tried to find a compromise + + + align:start position:0% +tried to find a compromise +now who wrote it + + align:start position:0% + + + + align:start position:0% + +all right you ready for this if you + + align:start position:0% +all right you ready for this if you + + + align:start position:0% +all right you ready for this if you +haven't heard of haven't heard of this + + align:start position:0% +haven't heard of haven't heard of this + + + align:start position:0% +haven't heard of haven't heard of this +book you'd never guess who wrote it + + align:start position:0% + + + + align:start position:0% + +i'll tell you why you'd never get it was + + align:start position:0% +i'll tell you why you'd never get it was + + + align:start position:0% +i'll tell you why you'd never get it was +a committee that wrote it + + align:start position:0% +a committee that wrote it + + + align:start position:0% +a committee that wrote it +[Laughter] + + align:start position:0% +[Laughter] + + + align:start position:0% +[Laughter] +it was a faculty committee at harvard + + align:start position:0% +it was a faculty committee at harvard + + + align:start position:0% +it was a faculty committee at harvard +believe it i mentioned harvard three + + align:start position:0% +believe it i mentioned harvard three + + + align:start position:0% +believe it i mentioned harvard three +times already + + align:start position:0% + + + + align:start position:0% + +it was a faculty committee at harvard uh + + align:start position:0% +it was a faculty committee at harvard uh + + + align:start position:0% +it was a faculty committee at harvard uh +commissioned by james by a very famous + + align:start position:0% +commissioned by james by a very famous + + + align:start position:0% +commissioned by james by a very famous +college president a lot of you can name + + align:start position:0% +college president a lot of you can name + + + align:start position:0% +college president a lot of you can name +a lot of nobel prize winning faculty + + align:start position:0% +a lot of nobel prize winning faculty + + + align:start position:0% +a lot of nobel prize winning faculty +members but it's hard to name college + + align:start position:0% +members but it's hard to name college + + + align:start position:0% +members but it's hard to name college +presidents + + align:start position:0% +presidents + + + align:start position:0% +presidents +but there's one that you ought to + + align:start position:0% +but there's one that you ought to + + + align:start position:0% +but there's one that you ought to +remember james bryant conant c-o-n-a-n-t + + align:start position:0% +remember james bryant conant c-o-n-a-n-t + + + align:start position:0% +remember james bryant conant c-o-n-a-n-t +uh + + align:start position:0% +uh + + + align:start position:0% +uh +and uh he commissioned this uh committee + + align:start position:0% +and uh he commissioned this uh committee + + + align:start position:0% +and uh he commissioned this uh committee +and the committee came back with this + + align:start position:0% +and the committee came back with this + + + align:start position:0% +and the committee came back with this +report and the report + + align:start position:0% +report and the report + + + align:start position:0% +report and the report +uh actually tried to make a compromise + + align:start position:0% +uh actually tried to make a compromise + + + align:start position:0% +uh actually tried to make a compromise +out of all of this uh we can go through + + align:start position:0% +out of all of this uh we can go through + + + align:start position:0% +out of all of this uh we can go through +what the compromise meant + + align:start position:0% +what the compromise meant + + + align:start position:0% +what the compromise meant +uh i'd like to take a minute or two to + + align:start position:0% +uh i'd like to take a minute or two to + + + align:start position:0% +uh i'd like to take a minute or two to +say what the compromise meant but the + + align:start position:0% +say what the compromise meant but the + + + align:start position:0% +say what the compromise meant but the +compromise never stuck and i'll tell you + + align:start position:0% +compromise never stuck and i'll tell you + + + align:start position:0% +compromise never stuck and i'll tell you +this + + align:start position:0% +this + + + align:start position:0% +this +let's see let's see what what + + align:start position:0% +let's see let's see what what + + + align:start position:0% +let's see let's see what what +what this very important book is about + + align:start position:0% + + + + align:start position:0% + +uh + + align:start position:0% +uh + + + align:start position:0% +uh +it's a book that's hard to get + + align:start position:0% + + + + align:start position:0% + +to my knowledge you might be able to get + + align:start position:0% +to my knowledge you might be able to get + + + align:start position:0% +to my knowledge you might be able to get +it on ebay you won't be able to get it + + align:start position:0% +it on ebay you won't be able to get it + + + align:start position:0% +it on ebay you won't be able to get it +on amazon.com + + align:start position:0% +on amazon.com + + + align:start position:0% +on amazon.com +i tell you where else you will not be + + align:start position:0% +i tell you where else you will not be + + + align:start position:0% +i tell you where else you will not be +able to get it + + align:start position:0% +able to get it + + + align:start position:0% +able to get it +harvard's bookstore + + align:start position:0% + + + + align:start position:0% + +um uh my copy was a gift + + align:start position:0% +um uh my copy was a gift + + + align:start position:0% +um uh my copy was a gift +from an older faculty member when i was + + align:start position:0% +from an older faculty member when i was + + + align:start position:0% +from an older faculty member when i was +a young faculty member + + align:start position:0% + + + + align:start position:0% + +now here's what they tried to do + + align:start position:0% + + + + align:start position:0% + +general education in the free society + + align:start position:0% +general education in the free society + + + align:start position:0% +general education in the free society +then i'll go back to these slides and + + align:start position:0% +then i'll go back to these slides and + + + align:start position:0% +then i'll go back to these slides and +then we'll get on and we'll finish up + + align:start position:0% +then we'll get on and we'll finish up + + + align:start position:0% +then we'll get on and we'll finish up +the class + + align:start position:0% +the class + + + align:start position:0% +the class +general education in a free society said + + align:start position:0% +general education in a free society said + + + align:start position:0% +general education in a free society said +that education has got to have two parts + + align:start position:0% + + + + align:start position:0% + +one part + + align:start position:0% +one part + + + align:start position:0% +one part +is pus is for the individual and the + + align:start position:0% +is pus is for the individual and the + + + align:start position:0% +is pus is for the individual and the +other part is for the state + + align:start position:0% + + + + align:start position:0% + +the part that's for the individual is + + align:start position:0% +the part that's for the individual is + + + align:start position:0% +the part that's for the individual is +called general education + + align:start position:0% +called general education + + + align:start position:0% +called general education +and you take many classical studies + + align:start position:0% +and you take many classical studies + + + align:start position:0% +and you take many classical studies +and it's supposed to be um to bring back + + align:start position:0% +and it's supposed to be um to bring back + + + align:start position:0% +and it's supposed to be um to bring back +character i'm gonna tell you why it + + align:start position:0% +character i'm gonna tell you why it + + + align:start position:0% +character i'm gonna tell you why it +never came back but that's + + align:start position:0% +never came back but that's + + + align:start position:0% +never came back but that's +that's what the argument was + + align:start position:0% +that's what the argument was + + + align:start position:0% +that's what the argument was +and that special education was the other + + align:start position:0% +and that special education was the other + + + align:start position:0% +and that special education was the other +one + + align:start position:0% +one + + + align:start position:0% +one +and special education was to um + + align:start position:0% +and special education was to um + + + align:start position:0% +and special education was to um +help you find a job in a career + + align:start position:0% + + + + align:start position:0% + +and given that the state + + align:start position:0% +and given that the state + + + align:start position:0% +and given that the state +uh pretty much determines + + align:start position:0% +uh pretty much determines + + + align:start position:0% +uh pretty much determines +what jobs are available + + align:start position:0% +what jobs are available + + + align:start position:0% +what jobs are available +and where your career is going that's + + align:start position:0% +and where your career is going that's + + + align:start position:0% +and where your career is going that's +indirectly how you satisfy + + align:start position:0% +indirectly how you satisfy + + + align:start position:0% +indirectly how you satisfy +the people who say + + align:start position:0% +the people who say + + + align:start position:0% +the people who say +we need to have education for the state + + align:start position:0% +we need to have education for the state + + + align:start position:0% +we need to have education for the state +and at first to get in the industrial + + align:start position:0% +and at first to get in the industrial + + + align:start position:0% +and at first to get in the industrial +revolution + + align:start position:0% +revolution + + + align:start position:0% +revolution +secondly to defend ourselves against + + align:start position:0% +secondly to defend ourselves against + + + align:start position:0% +secondly to defend ourselves against +guess what + + align:start position:0% + + + + align:start position:0% + +communism + + align:start position:0% +communism + + + align:start position:0% +communism +why were we afraid of communism + + align:start position:0% + + + + align:start position:0% + +we were afraid of communism because we + + align:start position:0% +we were afraid of communism because we + + + align:start position:0% +we were afraid of communism because we +were afraid of the russians + + align:start position:0% +were afraid of the russians + + + align:start position:0% +were afraid of the russians +we were afraid of the russians because + + align:start position:0% +we were afraid of the russians because + + + align:start position:0% +we were afraid of the russians because +the russians had a formula that said if + + align:start position:0% +the russians had a formula that said if + + + align:start position:0% +the russians had a formula that said if +we need three million engineers we will + + align:start position:0% +we need three million engineers we will + + + align:start position:0% +we need three million engineers we will +command that we shall have three million + + align:start position:0% +command that we shall have three million + + + align:start position:0% +command that we shall have three million +engineers in the united states if we + + align:start position:0% +engineers in the united states if we + + + align:start position:0% +engineers in the united states if we +need three million engineers we say well + + align:start position:0% +need three million engineers we say well + + + align:start position:0% +need three million engineers we say well +we've got some scholarships + + align:start position:0% +we've got some scholarships + + + align:start position:0% +we've got some scholarships +you know in other words could we compete + + align:start position:0% + + + + align:start position:0% + +with a culture like that + + align:start position:0% +with a culture like that + + + align:start position:0% +with a culture like that +that was the question + + align:start position:0% +that was the question + + + align:start position:0% +that was the question +all right so a lot of people who wanted + + align:start position:0% +all right so a lot of people who wanted + + + align:start position:0% +all right so a lot of people who wanted +education for the state wanted us to be + + align:start position:0% +education for the state wanted us to be + + + align:start position:0% +education for the state wanted us to be +competitive + + align:start position:0% +competitive + + + align:start position:0% +competitive +all of this free choice did not promise + + align:start position:0% +all of this free choice did not promise + + + align:start position:0% +all of this free choice did not promise +to be competitive + + align:start position:0% + + + + align:start position:0% + +okay uh so general this general + + align:start position:0% +okay uh so general this general + + + align:start position:0% +okay uh so general this general +education and free society said we + + align:start position:0% +education and free society said we + + + align:start position:0% +education and free society said we +should have + + align:start position:0% +should have + + + align:start position:0% +should have +two kinds general education and special + + align:start position:0% +two kinds general education and special + + + align:start position:0% +two kinds general education and special +education + + align:start position:0% +education + + + align:start position:0% +education +general education was what they put in + + align:start position:0% +general education was what they put in + + + align:start position:0% +general education was what they put in +the part of the curriculum we call the + + align:start position:0% +the part of the curriculum we call the + + + align:start position:0% +the part of the curriculum we call the +core curriculum that is the courses that + + align:start position:0% +core curriculum that is the courses that + + + align:start position:0% +core curriculum that is the courses that +everybody takes + + align:start position:0% +everybody takes + + + align:start position:0% +everybody takes +special education is what they call the + + align:start position:0% +special education is what they call the + + + align:start position:0% +special education is what they call the +major + + align:start position:0% +major + + + align:start position:0% +major +you want to be an engineer an economist + + align:start position:0% +you want to be an engineer an economist + + + align:start position:0% +you want to be an engineer an economist +or whatever that's what you specialize + + align:start position:0% +or whatever that's what you specialize + + + align:start position:0% +or whatever that's what you specialize +in and get your special education so you + + align:start position:0% +in and get your special education so you + + + align:start position:0% +in and get your special education so you +see this this book did have + + align:start position:0% +see this this book did have + + + align:start position:0% +see this this book did have +a formula that a lot of which that we + + align:start position:0% +a formula that a lot of which that we + + + align:start position:0% +a formula that a lot of which that we +live by at least in the united states + + align:start position:0% +live by at least in the united states + + + align:start position:0% +live by at least in the united states +today + + align:start position:0% +today + + + align:start position:0% +today +all right + + align:start position:0% +all right + + + align:start position:0% +all right +then the book comes out in its early + + align:start position:0% +then the book comes out in its early + + + align:start position:0% +then the book comes out in its early +pages we're talking about before you get + + align:start position:0% +pages we're talking about before you get + + + align:start position:0% +pages we're talking about before you get +to think to page + + align:start position:0% +to think to page + + + align:start position:0% +to think to page +uh we have another we have until five + + align:start position:0% +uh we have another we have until five + + + align:start position:0% +uh we have another we have until five +minutes of + + align:start position:0% +minutes of + + + align:start position:0% +minutes of +and this is the class so + + align:start position:0% + + + + align:start position:0% + +yeah so what at uh 55 + + align:start position:0% +yeah so what at uh 55 + + + align:start position:0% +yeah so what at uh 55 +10 55 uh yeah we'll be out of here + + align:start position:0% + + + + align:start position:0% + +all right + + align:start position:0% + + + + align:start position:0% + +i could have said that we could dispose + + align:start position:0% +i could have said that we could dispose + + + align:start position:0% +i could have said that we could dispose +of those pizzas + + align:start position:0% +of those pizzas + + + align:start position:0% +of those pizzas +that might not be ethical + + align:start position:0% +that might not be ethical + + + align:start position:0% +that might not be ethical +all right uh let's finish up this + + align:start position:0% +all right uh let's finish up this + + + align:start position:0% +all right uh let's finish up this +thing here + + align:start position:0% +thing here + + + align:start position:0% +thing here +that ethics was included + + align:start position:0% +that ethics was included + + + align:start position:0% +that ethics was included +in uh the i forgot to mention ethics + + align:start position:0% +in uh the i forgot to mention ethics + + + align:start position:0% +in uh the i forgot to mention ethics +when i was mentioning these courses + + align:start position:0% +when i was mentioning these courses + + + align:start position:0% +when i was mentioning these courses +uh that i don't know why i forgot to + + align:start position:0% +uh that i don't know why i forgot to + + + align:start position:0% +uh that i don't know why i forgot to +mention that + + align:start position:0% +mention that + + + align:start position:0% +mention that +but ethics was included in all of this + + align:start position:0% +but ethics was included in all of this + + + align:start position:0% +but ethics was included in all of this +and what the what the what the uh + + align:start position:0% +and what the what the what the uh + + + align:start position:0% +and what the what the what the uh +general education and free society said + + align:start position:0% +general education and free society said + + + align:start position:0% +general education and free society said +was + + align:start position:0% + + + + align:start position:0% + +the big challenge to + + align:start position:0% +the big challenge to + + + align:start position:0% +the big challenge to +general education there were two + + align:start position:0% +general education there were two + + + align:start position:0% +general education there were two +challenges to general education + + align:start position:0% +challenges to general education + + + align:start position:0% +challenges to general education +it said this in 1945 i'm sure that you + + align:start position:0% +it said this in 1945 i'm sure that you + + + align:start position:0% +it said this in 1945 i'm sure that you +it sounds like it's been it was said in + + align:start position:0% +it sounds like it's been it was said in + + + align:start position:0% +it sounds like it's been it was said in +2005. + + align:start position:0% +2005. + + + align:start position:0% +2005. +they said there were two big challenges + + align:start position:0% + + + + align:start position:0% + +one of the challenges was + + align:start position:0% + + + + align:start position:0% + +that + + align:start position:0% + + + + align:start position:0% + +they call it the proliferation of + + align:start position:0% +they call it the proliferation of + + + align:start position:0% +they call it the proliferation of +knowledge + + align:start position:0% +knowledge + + + align:start position:0% +knowledge +there's just too many things too much + + align:start position:0% +there's just too many things too much + + + align:start position:0% +there's just too many things too much +too many books being written + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +out of all of these things + + align:start position:0% +out of all of these things + + + align:start position:0% +out of all of these things +which ones do you choose + + align:start position:0% +which ones do you choose + + + align:start position:0% +which ones do you choose +to teach to everybody + + align:start position:0% + + + + align:start position:0% + +the second one was + + align:start position:0% +the second one was + + + align:start position:0% +the second one was +diversification of culture + + align:start position:0% + + + + align:start position:0% + +the united states population between + + align:start position:0% +the united states population between + + + align:start position:0% +the united states population between + + align:start position:0% + + + align:start position:0% +and 1950 uh + + align:start position:0% +and 1950 uh + + + align:start position:0% +and 1950 uh +i think increased by a pro + + align:start position:0% +i think increased by a pro + + + align:start position:0% +i think increased by a pro +of kids in school increased by something + + align:start position:0% +of kids in school increased by something + + + align:start position:0% +of kids in school increased by something +like + + align:start position:0% +like + + + align:start position:0% +like +20 times + + align:start position:0% +20 times + + + align:start position:0% +20 times +that's another number for you to verify + + align:start position:0% +that's another number for you to verify + + + align:start position:0% +that's another number for you to verify +but it's a big number + + align:start position:0% +but it's a big number + + + align:start position:0% +but it's a big number +and uh the question then is how do you + + align:start position:0% +and uh the question then is how do you + + + align:start position:0% +and uh the question then is how do you +teach + + align:start position:0% +teach + + + align:start position:0% +teach +once you've decided what to teach how do + + align:start position:0% +once you've decided what to teach how do + + + align:start position:0% +once you've decided what to teach how do +you teach it to each individual given + + align:start position:0% +you teach it to each individual given + + + align:start position:0% +you teach it to each individual given +different tastes and abilities and all + + align:start position:0% +different tastes and abilities and all + + + align:start position:0% +different tastes and abilities and all +of + + align:start position:0% +of + + + align:start position:0% +of +that okay + + align:start position:0% +that okay + + + align:start position:0% +that okay +so they said that + + align:start position:0% +so they said that + + + align:start position:0% +so they said that +what they needed was what was called a + + align:start position:0% +what they needed was what was called a + + + align:start position:0% +what they needed was what was called a +unity principle + + align:start position:0% + + + + align:start position:0% + +and that is that after you have + + align:start position:0% +and that is that after you have + + + align:start position:0% +and that is that after you have +chosen all from all of this wealth of + + align:start position:0% +chosen all from all of this wealth of + + + align:start position:0% +chosen all from all of this wealth of +knowledge + + align:start position:0% +knowledge + + + align:start position:0% +knowledge +and learning better stated learning + + align:start position:0% +and learning better stated learning + + + align:start position:0% +and learning better stated learning +which + + align:start position:0% +which + + + align:start position:0% +which +few things you're going to teach to + + align:start position:0% +few things you're going to teach to + + + align:start position:0% +few things you're going to teach to +everybody + + align:start position:0% +everybody + + + align:start position:0% +everybody +and after you've decided + + align:start position:0% +and after you've decided + + + align:start position:0% +and after you've decided +that + + align:start position:0% + + + + align:start position:0% + +that you you know how to teach it to + + align:start position:0% +that you you know how to teach it to + + + align:start position:0% +that you you know how to teach it to +each individual + + align:start position:0% +each individual + + + align:start position:0% +each individual +what you've got to do is to say that + + align:start position:0% +what you've got to do is to say that + + + align:start position:0% +what you've got to do is to say that +what a person has learned + + align:start position:0% +what a person has learned + + + align:start position:0% +what a person has learned +in school + + align:start position:0% +in school + + + align:start position:0% +in school +has got to help them learn more when + + align:start position:0% +has got to help them learn more when + + + align:start position:0% +has got to help them learn more when +they get out of school + + align:start position:0% +they get out of school + + + align:start position:0% +they get out of school +so it's got all of this stuff has to fit + + align:start position:0% +so it's got all of this stuff has to fit + + + align:start position:0% +so it's got all of this stuff has to fit +into some kind of pattern + + align:start position:0% +into some kind of pattern + + + align:start position:0% +into some kind of pattern +now we did that in this course we were + + align:start position:0% +now we did that in this course we were + + + align:start position:0% +now we did that in this course we were +very to be able to show the diff show a + + align:start position:0% +very to be able to show the diff show a + + + align:start position:0% +very to be able to show the diff show a +pattern between the structure + + align:start position:0% +pattern between the structure + + + align:start position:0% +pattern between the structure +of ethics and the structure of science + + align:start position:0% +of ethics and the structure of science + + + align:start position:0% +of ethics and the structure of science +when we said talk about the empirical + + align:start position:0% +when we said talk about the empirical + + + align:start position:0% +when we said talk about the empirical +the rational and now + + align:start position:0% +the rational and now + + + align:start position:0% +the rational and now +uh which i haven't gone into any detail + + align:start position:0% +uh which i haven't gone into any detail + + + align:start position:0% +uh which i haven't gone into any detail +on because i'm waiting for the + + align:start position:0% +on because i'm waiting for the + + + align:start position:0% +on because i'm waiting for the +believe it or not three mile island + + align:start position:0% +believe it or not three mile island + + + align:start position:0% +believe it or not three mile island +piece to do it + + align:start position:0% +piece to do it + + + align:start position:0% +piece to do it +but uh the question is how do you take + + align:start position:0% +but uh the question is how do you take + + + align:start position:0% +but uh the question is how do you take +learning from music + + align:start position:0% +learning from music + + + align:start position:0% +learning from music +and + + align:start position:0% +and + + + align:start position:0% +and +mathematics + + align:start position:0% +mathematics + + + align:start position:0% +mathematics +and + + align:start position:0% +and + + + align:start position:0% +and +art + + align:start position:0% +art + + + align:start position:0% +art +and physics + + align:start position:0% +and physics + + + align:start position:0% +and physics +how do you make sense of all of that + + align:start position:0% +how do you make sense of all of that + + + align:start position:0% +how do you make sense of all of that +and what they went through was with some + + align:start position:0% +and what they went through was with some + + + align:start position:0% +and what they went through was with some +formulas + + align:start position:0% +formulas + + + align:start position:0% +formulas +and many proposals have come in but + + align:start position:0% +and many proposals have come in but + + + align:start position:0% +and many proposals have come in but +nobody has accepted any of them + + align:start position:0% +nobody has accepted any of them + + + align:start position:0% +nobody has accepted any of them +as a principal for general education + + align:start position:0% +as a principal for general education + + + align:start position:0% +as a principal for general education +let's name some the first one that came + + align:start position:0% +let's name some the first one that came + + + align:start position:0% +let's name some the first one that came +in was christianity + + align:start position:0% +in was christianity + + + align:start position:0% +in was christianity +well not everybody's a christian + + align:start position:0% +well not everybody's a christian + + + align:start position:0% +well not everybody's a christian +so they threw that out + + align:start position:0% +so they threw that out + + + align:start position:0% +so they threw that out +uh i'll name one or two + + align:start position:0% +uh i'll name one or two + + + align:start position:0% +uh i'll name one or two +cut me off this is a good place to cut + + align:start position:0% +cut me off this is a good place to cut + + + align:start position:0% +cut me off this is a good place to cut +me off if you think of some others that + + align:start position:0% +me off if you think of some others that + + + align:start position:0% +me off if you think of some others that +some other proposals and why they if + + align:start position:0% +some other proposals and why they if + + + align:start position:0% +some other proposals and why they if +they came up and why they were slashed + + align:start position:0% +they came up and why they were slashed + + + align:start position:0% +they came up and why they were slashed +down + + align:start position:0% +down + + + align:start position:0% +down +uh one of them was um + + align:start position:0% +uh one of them was um + + + align:start position:0% +uh one of them was um +cultural literacy + + align:start position:0% + + + + align:start position:0% + +back in the 50s it was called the + + align:start position:0% +back in the 50s it was called the + + + align:start position:0% +back in the 50s it was called the +chicago school they dedicated themselves + + align:start position:0% +chicago school they dedicated themselves + + + align:start position:0% +chicago school they dedicated themselves +to + + align:start position:0% +to + + + align:start position:0% +to +well + + align:start position:0% +well + + + align:start position:0% +well +that's been thrown out + + align:start position:0% + + + + align:start position:0% + +nobody just seems to benefit from a + + align:start position:0% +nobody just seems to benefit from a + + + align:start position:0% +nobody just seems to benefit from a +vocabulary + + align:start position:0% +vocabulary + + + align:start position:0% +vocabulary +you don't get meaning you don't get + + align:start position:0% +you don't get meaning you don't get + + + align:start position:0% +you don't get meaning you don't get +context too much of it if it's + + align:start position:0% +context too much of it if it's + + + align:start position:0% +context too much of it if it's +technological it changes too fast + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% +um + + + align:start position:0% +um +critical thinking + + align:start position:0% +critical thinking + + + align:start position:0% +critical thinking +actually that was the chicago school + + align:start position:0% +actually that was the chicago school + + + align:start position:0% +actually that was the chicago school +critical thinking + + align:start position:0% + + + + align:start position:0% + +okay that got thrown out can anybody + + align:start position:0% +okay that got thrown out can anybody + + + align:start position:0% +okay that got thrown out can anybody +name any others a whole bunch of them + + align:start position:0% + + + + align:start position:0% + +the book said that it did not have + + align:start position:0% +the book said that it did not have + + + align:start position:0% +the book said that it did not have +a solution to this problem of a unity + + align:start position:0% +a solution to this problem of a unity + + + align:start position:0% +a solution to this problem of a unity +principle + + align:start position:0% +principle + + + align:start position:0% +principle +it had the faith that somebody was going + + align:start position:0% +it had the faith that somebody was going + + + align:start position:0% +it had the faith that somebody was going +to find one nobody's found one to this + + align:start position:0% +to find one nobody's found one to this + + + align:start position:0% +to find one nobody's found one to this +day + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% + + + + align:start position:0% + +that means we're struggling along with + + align:start position:0% + + + + align:start position:0% + +what was left out of this piece + + align:start position:0% +what was left out of this piece + + + align:start position:0% +what was left out of this piece +and + + align:start position:0% +and + + + align:start position:0% +and +one of the big casualties of it + + align:start position:0% +one of the big casualties of it + + + align:start position:0% +one of the big casualties of it +still + + align:start position:0% +still + + + align:start position:0% +still +is + + align:start position:0% +is + + + align:start position:0% +is +character + + align:start position:0% + + + + align:start position:0% + +what is engineering ah let's see now + + align:start position:0% +what is engineering ah let's see now + + + align:start position:0% +what is engineering ah let's see now +i really wanted this to be a good + + align:start position:0% +i really wanted this to be a good + + + align:start position:0% +i really wanted this to be a good +picture + + align:start position:0% + + + + align:start position:0% + +can anybody tell what this picture is of + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% + + + + align:start position:0% + +you can it's a nighttime view + + align:start position:0% +you can it's a nighttime view + + + align:start position:0% +you can it's a nighttime view +of the status center + + align:start position:0% +of the status center + + + align:start position:0% +of the status center +and this building is right up here on + + align:start position:0% +and this building is right up here on + + + align:start position:0% +and this building is right up here on +campus + + align:start position:0% +campus + + + align:start position:0% +campus +okay now we did discuss some ideas about + + align:start position:0% +okay now we did discuss some ideas about + + + align:start position:0% +okay now we did discuss some ideas about +what is what really is engineering + + align:start position:0% +what is what really is engineering + + + align:start position:0% +what is what really is engineering +um + + align:start position:0% +um + + + align:start position:0% +um +joel moses dr moses came in and he said + + align:start position:0% +joel moses dr moses came in and he said + + + align:start position:0% +joel moses dr moses came in and he said +that + + align:start position:0% +that + + + align:start position:0% +that +plato and aristotle gave us two ways of + + align:start position:0% +plato and aristotle gave us two ways of + + + align:start position:0% +plato and aristotle gave us two ways of +thinking + + align:start position:0% + + + + align:start position:0% + +aristotle gave us + + align:start position:0% +aristotle gave us + + + align:start position:0% +aristotle gave us +a + + align:start position:0% +a + + + align:start position:0% +a +systematic way of thinking + + align:start position:0% +systematic way of thinking + + + align:start position:0% +systematic way of thinking +that was what we call analytic + + align:start position:0% + + + + align:start position:0% + +and that is if you want to understand + + align:start position:0% +and that is if you want to understand + + + align:start position:0% +and that is if you want to understand +something + + align:start position:0% + + + + align:start position:0% + +you break it up into its parts + + align:start position:0% +you break it up into its parts + + + align:start position:0% +you break it up into its parts +and you understand the parts + + align:start position:0% +and you understand the parts + + + align:start position:0% +and you understand the parts +and then you put the parts back together + + align:start position:0% +and then you put the parts back together + + + align:start position:0% +and then you put the parts back together +and maybe you can understand the whole + + align:start position:0% + + + + align:start position:0% + +plato said was + + align:start position:0% +plato said was + + + align:start position:0% +plato said was +synthetic + + align:start position:0% + + + + align:start position:0% + +plato said + + align:start position:0% +plato said + + + align:start position:0% +plato said +well + + align:start position:0% +well + + + align:start position:0% +well +if we want to understand a thing + + align:start position:0% + + + + align:start position:0% + +we first say what it is + + align:start position:0% +we first say what it is + + + align:start position:0% +we first say what it is +and then we say + + align:start position:0% + + + + align:start position:0% + +what it is not + + align:start position:0% + + + + align:start position:0% + +and then somehow out of a synthetic + + align:start position:0% +and then somehow out of a synthetic + + + align:start position:0% +and then somehow out of a synthetic +approach we're able to understand better + + align:start position:0% +approach we're able to understand better + + + align:start position:0% +approach we're able to understand better +what this thing is that we're talking + + align:start position:0% +what this thing is that we're talking + + + align:start position:0% +what this thing is that we're talking +about as a whole + + align:start position:0% + + + + align:start position:0% + +and when you bring these two + + align:start position:0% +and when you bring these two + + + align:start position:0% +and when you bring these two +approaches or traditions together into + + align:start position:0% +approaches or traditions together into + + + align:start position:0% +approaches or traditions together into +one + + align:start position:0% + + + + align:start position:0% + +you get something different from the two + + align:start position:0% +you get something different from the two + + + align:start position:0% +you get something different from the two +and we call it engineering + + align:start position:0% + + + + align:start position:0% + +now + + align:start position:0% +now + + + align:start position:0% +now +uh the reason that we are going to take + + align:start position:0% +uh the reason that we are going to take + + + align:start position:0% +uh the reason that we are going to take +that uh + + align:start position:0% +that uh + + + align:start position:0% +that uh +uh + + align:start position:0% +uh + + + align:start position:0% +uh +idea very seriously is not + + align:start position:0% +idea very seriously is not + + + align:start position:0% +idea very seriously is not +because simply because somebody's here + + align:start position:0% +because simply because somebody's here + + + align:start position:0% +because simply because somebody's here +to say it + + align:start position:0% +to say it + + + align:start position:0% +to say it +not because it is compelling + + align:start position:0% +not because it is compelling + + + align:start position:0% +not because it is compelling +but because there really isn't a + + align:start position:0% +but because there really isn't a + + + align:start position:0% +but because there really isn't a +philosophy of engineering out here it + + align:start position:0% +philosophy of engineering out here it + + + align:start position:0% +philosophy of engineering out here it +really isn't + + align:start position:0% +really isn't + + + align:start position:0% +really isn't +i'm writing a book on it so i have my + + align:start position:0% +i'm writing a book on it so i have my + + + align:start position:0% +i'm writing a book on it so i have my +views about it + + align:start position:0% +views about it + + + align:start position:0% +views about it +and and there will be a time towards the + + align:start position:0% +and and there will be a time towards the + + + align:start position:0% +and and there will be a time towards the +end of the class when i will share my + + align:start position:0% +end of the class when i will share my + + + align:start position:0% +end of the class when i will share my +views which you will find very + + align:start position:0% +views which you will find very + + + align:start position:0% +views which you will find very +interesting it doesn't really conflict + + align:start position:0% +interesting it doesn't really conflict + + + align:start position:0% +interesting it doesn't really conflict +with all this it comes it + + align:start position:0% +with all this it comes it + + + align:start position:0% +with all this it comes it +it uh + + align:start position:0% +it uh + + + align:start position:0% +it uh +subsumes + + align:start position:0% + + + + align:start position:0% + +it and what i will say is that + + align:start position:0% +it and what i will say is that + + + align:start position:0% +it and what i will say is that +engineering uh began + + align:start position:0% +engineering uh began + + + align:start position:0% +engineering uh began +when what used to be called + + align:start position:0% +when what used to be called + + + align:start position:0% +when what used to be called +uh the practical arts + + align:start position:0% +uh the practical arts + + + align:start position:0% +uh the practical arts +um + + align:start position:0% +um + + + align:start position:0% +um +road building things like that came + + align:start position:0% +road building things like that came + + + align:start position:0% +road building things like that came +together with the science of mathematics + + align:start position:0% + + + + align:start position:0% + +okay we put those two together + + align:start position:0% +okay we put those two together + + + align:start position:0% +okay we put those two together +and we're just about done we had talked + + align:start position:0% +and we're just about done we had talked + + + align:start position:0% +and we're just about done we had talked +about + + align:start position:0% + + + + align:start position:0% + +did i do no i didn't it's just very + + align:start position:0% +did i do no i didn't it's just very + + + align:start position:0% +did i do no i didn't it's just very +light + + align:start position:0% +light + + + align:start position:0% +light +is she okay + + align:start position:0% + + + + align:start position:0% + +that's right + + align:start position:0% +that's right + + + align:start position:0% +that's right +uh + + align:start position:0% +uh + + + align:start position:0% +uh +that um + + align:start position:0% +that um + + + align:start position:0% +that um +we talked about how engineering and + + align:start position:0% +we talked about how engineering and + + + align:start position:0% +we talked about how engineering and +ethics can engage each other sometimes + + align:start position:0% +ethics can engage each other sometimes + + + align:start position:0% +ethics can engage each other sometimes +you don't really have to be an engineer + + align:start position:0% +you don't really have to be an engineer + + + align:start position:0% +you don't really have to be an engineer +you really don't need to know the + + align:start position:0% +you really don't need to know the + + + align:start position:0% +you really don't need to know the +technological system + + align:start position:0% +technological system + + + align:start position:0% +technological system +what you do then if this is if this is + + align:start position:0% +what you do then if this is if this is + + + align:start position:0% +what you do then if this is if this is +technology and if these are people then + + align:start position:0% +technology and if these are people then + + + align:start position:0% +technology and if these are people then +you study their interactions + + align:start position:0% +you study their interactions + + + align:start position:0% +you study their interactions +and how they relate themselves to + + align:start position:0% +and how they relate themselves to + + + align:start position:0% +and how they relate themselves to +technology and you make a decision we + + align:start position:0% +technology and you make a decision we + + + align:start position:0% +technology and you make a decision we +did that already in class + + align:start position:0% +did that already in class + + + align:start position:0% +did that already in class +uh particularly when we analyzed the a7d + + align:start position:0% +uh particularly when we analyzed the a7d + + + align:start position:0% +uh particularly when we analyzed the a7d +case you really didn't have to know a + + align:start position:0% +case you really didn't have to know a + + + align:start position:0% +case you really didn't have to know a +whole lot about airplanes and ever and + + align:start position:0% +whole lot about airplanes and ever and + + + align:start position:0% +whole lot about airplanes and ever and +brakes + + align:start position:0% + + + + align:start position:0% + +in this case and when we talk about uh + + align:start position:0% +in this case and when we talk about uh + + + align:start position:0% +in this case and when we talk about uh +like for three mile island you really + + align:start position:0% +like for three mile island you really + + + align:start position:0% +like for three mile island you really +have to know what a nuclear plant is + + align:start position:0% + + + + align:start position:0% + +to understand uh about how uh to make an + + align:start position:0% +to understand uh about how uh to make an + + + align:start position:0% +to understand uh about how uh to make an +ethical judgment about the situation + + align:start position:0% +ethical judgment about the situation + + + align:start position:0% +ethical judgment about the situation +and + + align:start position:0% + + + + align:start position:0% + +there is this interdisciplinary mode now + + align:start position:0% +there is this interdisciplinary mode now + + + align:start position:0% +there is this interdisciplinary mode now +i want to take a minute to say something + + align:start position:0% +i want to take a minute to say something + + + align:start position:0% +i want to take a minute to say something +about that and according to my watch + + align:start position:0% +about that and according to my watch + + + align:start position:0% +about that and according to my watch +we've got six minutes and we're out of + + align:start position:0% +we've got six minutes and we're out of + + + align:start position:0% +we've got six minutes and we're out of +here + + align:start position:0% + + + + align:start position:0% + +now + + align:start position:0% + + + + align:start position:0% + +this slide here provoked + + align:start position:0% +this slide here provoked + + + align:start position:0% +this slide here provoked +a long and in-depth discussion yesterday + + align:start position:0% +a long and in-depth discussion yesterday + + + align:start position:0% +a long and in-depth discussion yesterday +you know both in the class and outside + + align:start position:0% +you know both in the class and outside + + + align:start position:0% +you know both in the class and outside +of it i went to + + align:start position:0% +of it i went to + + + align:start position:0% +of it i went to +dick lester's office which is actually + + align:start position:0% +dick lester's office which is actually + + + align:start position:0% +dick lester's office which is actually +in the same suite that i'm in + + align:start position:0% +in the same suite that i'm in + + + align:start position:0% +in the same suite that i'm in +went down and we talked for about i + + align:start position:0% +went down and we talked for about i + + + align:start position:0% +went down and we talked for about i +think we had lunch together in his + + align:start position:0% +think we had lunch together in his + + + align:start position:0% +think we had lunch together in his +office and we talked about almost an + + align:start position:0% +office and we talked about almost an + + + align:start position:0% +office and we talked about almost an +hour + + align:start position:0% +hour + + + align:start position:0% +hour +um + + align:start position:0% +um + + + align:start position:0% +um +this one is + + align:start position:0% +this one is + + + align:start position:0% +this one is +the big issue here because what it says + + align:start position:0% +the big issue here because what it says + + + align:start position:0% +the big issue here because what it says +is + + align:start position:0% +is + + + align:start position:0% +is +that there's a possibility when you + + align:start position:0% +that there's a possibility when you + + + align:start position:0% +that there's a possibility when you +engage two learned disciplines + + align:start position:0% + + + + align:start position:0% + +that in order to solve the problem + + align:start position:0% +that in order to solve the problem + + + align:start position:0% +that in order to solve the problem +you have to throw out one of the + + align:start position:0% +you have to throw out one of the + + + align:start position:0% +you have to throw out one of the +fundamental principles of one of those + + align:start position:0% +fundamental principles of one of those + + + align:start position:0% +fundamental principles of one of those +disciplines + + align:start position:0% +disciplines + + + align:start position:0% +disciplines +now let's see how that happens in ethics + + align:start position:0% +now let's see how that happens in ethics + + + align:start position:0% +now let's see how that happens in ethics +is what i did with this paper + + align:start position:0% +is what i did with this paper + + + align:start position:0% +is what i did with this paper +when i said + + align:start position:0% +when i said + + + align:start position:0% +when i said +let's put a person + + align:start position:0% +let's put a person + + + align:start position:0% +let's put a person +in a situation + + align:start position:0% + + + + align:start position:0% + +and this case was my uncle roy + + align:start position:0% +and this case was my uncle roy + + + align:start position:0% +and this case was my uncle roy +and other cases we call them + + align:start position:0% +and other cases we call them + + + align:start position:0% +and other cases we call them +uh matum and kirky + + align:start position:0% +uh matum and kirky + + + align:start position:0% +uh matum and kirky +uh the the nigerians call it + + align:start position:0% +uh the the nigerians call it + + + align:start position:0% +uh the the nigerians call it +character + + align:start position:0% +character + + + align:start position:0% +character +uh + + align:start position:0% + + + + align:start position:0% + +jews call it the hasid the number names + + align:start position:0% +jews call it the hasid the number names + + + align:start position:0% +jews call it the hasid the number names +you put a person into a situation + + align:start position:0% +you put a person into a situation + + + align:start position:0% +you put a person into a situation +who is not a virtuous person now once + + align:start position:0% +who is not a virtuous person now once + + + align:start position:0% +who is not a virtuous person now once +you do that you're outside of the realm + + align:start position:0% +you do that you're outside of the realm + + + align:start position:0% +you do that you're outside of the realm +of everything that western ethics has to + + align:start position:0% +of everything that western ethics has to + + + align:start position:0% +of everything that western ethics has to +say you're outside of the realm + + align:start position:0% +say you're outside of the realm + + + align:start position:0% +say you're outside of the realm +because we're not looking to do the + + align:start position:0% +because we're not looking to do the + + + align:start position:0% +because we're not looking to do the +right thing + + align:start position:0% +right thing + + + align:start position:0% +right thing +we're talking about a situation that is + + align:start position:0% +we're talking about a situation that is + + + align:start position:0% +we're talking about a situation that is +that is exigent you have to make a + + align:start position:0% +that is exigent you have to make a + + + align:start position:0% +that is exigent you have to make a +decision right away potentially lethal + + align:start position:0% +decision right away potentially lethal + + + align:start position:0% +decision right away potentially lethal +so you have to make a decision + + align:start position:0% +so you have to make a decision + + + align:start position:0% +so you have to make a decision +uh + + align:start position:0% +uh + + + align:start position:0% +uh +and the question is after you've done it + + align:start position:0% +and the question is after you've done it + + + align:start position:0% +and the question is after you've done it +here + + align:start position:0% +here + + + align:start position:0% +here +and even if you've done the wrong thing + + align:start position:0% +and even if you've done the wrong thing + + + align:start position:0% +and even if you've done the wrong thing +will the rest of the society forgive you + + align:start position:0% +will the rest of the society forgive you + + + align:start position:0% +will the rest of the society forgive you +now + + align:start position:0% +now + + + align:start position:0% +now +when i brought this thing up with + + align:start position:0% +when i brought this thing up with + + + align:start position:0% +when i brought this thing up with +philosophers + + align:start position:0% +philosophers + + + align:start position:0% +philosophers +the first time + + align:start position:0% +the first time + + + align:start position:0% +the first time +they were of one mind in total agreement + + align:start position:0% +they were of one mind in total agreement + + + align:start position:0% +they were of one mind in total agreement +total agreement that this was outside of + + align:start position:0% +total agreement that this was outside of + + + align:start position:0% +total agreement that this was outside of +the realm of anything we call ethics + + align:start position:0% +the realm of anything we call ethics + + + align:start position:0% +the realm of anything we call ethics +or moral philosophy + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +they finally accepted it + + align:start position:0% +they finally accepted it + + + align:start position:0% +they finally accepted it +but it's outside the realm + + align:start position:0% +but it's outside the realm + + + align:start position:0% +but it's outside the realm +now here's what i want you to try to do + + align:start position:0% +now here's what i want you to try to do + + + align:start position:0% +now here's what i want you to try to do +i want you to try to do two things + + align:start position:0% +i want you to try to do two things + + + align:start position:0% +i want you to try to do two things +first of all i want you to try to + + align:start position:0% +first of all i want you to try to + + + align:start position:0% +first of all i want you to try to +imagine + + align:start position:0% +imagine + + + align:start position:0% +imagine +that you were + + align:start position:0% +that you were + + + align:start position:0% +that you were +that you were doing + + align:start position:0% +that you were doing + + + align:start position:0% +that you were doing +this + + align:start position:0% +this + + + align:start position:0% +this +but you're doing it for your + + align:start position:0% +but you're doing it for your + + + align:start position:0% +but you're doing it for your +dissertation + + align:start position:0% +dissertation + + + align:start position:0% +dissertation +your committee is going to say no + + align:start position:0% + + + + align:start position:0% + +let's say that you're a faculty member + + align:start position:0% +let's say that you're a faculty member + + + align:start position:0% +let's say that you're a faculty member +and you want to do this + + align:start position:0% +and you want to do this + + + align:start position:0% +and you want to do this +and you want to go out for tenure + + align:start position:0% +and you want to go out for tenure + + + align:start position:0% +and you want to go out for tenure +the committee's going to say no all + + align:start position:0% +the committee's going to say no all + + + align:start position:0% +the committee's going to say no all +right so so there is a i + + align:start position:0% +right so so there is a i + + + align:start position:0% +right so so there is a i +argue and i'm not alone in this that um + + align:start position:0% +argue and i'm not alone in this that um + + + align:start position:0% +argue and i'm not alone in this that um +and lester is a guy who uh + + align:start position:0% +and lester is a guy who uh + + + align:start position:0% +and lester is a guy who uh +does um public policy + + align:start position:0% +does um public policy + + + align:start position:0% +does um public policy +and had been doing it uh when he became + + align:start position:0% +and had been doing it uh when he became + + + align:start position:0% +and had been doing it uh when he became +when he came here + + align:start position:0% +when he came here + + + align:start position:0% +when he came here +uh along with nuclear engineering + + align:start position:0% +uh along with nuclear engineering + + + align:start position:0% +uh along with nuclear engineering +and he had to deal with this problem in + + align:start position:0% +and he had to deal with this problem in + + + align:start position:0% +and he had to deal with this problem in +terms of getting rank continued + + align:start position:0% +terms of getting rank continued + + + align:start position:0% +terms of getting rank continued +so the question is when you're when + + align:start position:0% +so the question is when you're when + + + align:start position:0% +so the question is when you're when +you're engaging two or more learned + + align:start position:0% +you're engaging two or more learned + + + align:start position:0% +you're engaging two or more learned +disciplines + + align:start position:0% +disciplines + + + align:start position:0% +disciplines +what do you do if you encounter a + + align:start position:0% +what do you do if you encounter a + + + align:start position:0% +what do you do if you encounter a +problem that you can solve but at the + + align:start position:0% +problem that you can solve but at the + + + align:start position:0% +problem that you can solve but at the +expense + + align:start position:0% +expense + + + align:start position:0% +expense +of a first principle in one of the + + align:start position:0% +of a first principle in one of the + + + align:start position:0% +of a first principle in one of the +disciplines that you're bringing + + align:start position:0% +disciplines that you're bringing + + + align:start position:0% +disciplines that you're bringing +together + + align:start position:0% +together + + + align:start position:0% +together +what normally happens out of that is + + align:start position:0% +what normally happens out of that is + + + align:start position:0% +what normally happens out of that is +that you spawn a brand new distance + + align:start position:0% +that you spawn a brand new distance + + + align:start position:0% +that you spawn a brand new distance +what happens when you spawn a brand new + + align:start position:0% +what happens when you spawn a brand new + + + align:start position:0% +what happens when you spawn a brand new +discipline is that you're the only + + align:start position:0% +discipline is that you're the only + + + align:start position:0% +discipline is that you're the only +expert on the planet + + align:start position:0% +expert on the planet + + + align:start position:0% +expert on the planet +on that new discipline + + align:start position:0% +on that new discipline + + + align:start position:0% +on that new discipline +and anybody who's going to make a + + align:start position:0% +and anybody who's going to make a + + + align:start position:0% +and anybody who's going to make a +judgment about it is outside the realm + + align:start position:0% +judgment about it is outside the realm + + + align:start position:0% +judgment about it is outside the realm +it takes time + + align:start position:0% +it takes time + + + align:start position:0% +it takes time +this is a cultural issue + + align:start position:0% +this is a cultural issue + + + align:start position:0% +this is a cultural issue +so um + + align:start position:0% +so um + + + align:start position:0% +so um +i'm just going to conclude go and just + + align:start position:0% +i'm just going to conclude go and just + + + align:start position:0% +i'm just going to conclude go and just +show you some of these other slides + + align:start position:0% +show you some of these other slides + + + align:start position:0% +show you some of these other slides +actually + + align:start position:0% + + + + align:start position:0% + +that uh the uh + + align:start position:0% +that uh the uh + + + align:start position:0% +that uh the uh +three mile allen case was aggravated by + + align:start position:0% +three mile allen case was aggravated by + + + align:start position:0% +three mile allen case was aggravated by +some real events and and movies that + + align:start position:0% +some real events and and movies that + + + align:start position:0% +some real events and and movies that +were made of real events + + align:start position:0% +were made of real events + + + align:start position:0% +were made of real events +and this particular case occurred + + align:start position:0% +and this particular case occurred + + + align:start position:0% +and this particular case occurred +this particular movie came out two weeks + + align:start position:0% +this particular movie came out two weeks + + + align:start position:0% +this particular movie came out two weeks +before three mile island actually + + align:start position:0% +before three mile island actually + + + align:start position:0% +before three mile island actually +happened it was almost as though it + + align:start position:0% +happened it was almost as though it + + + align:start position:0% +happened it was almost as though it +predicted + + align:start position:0% +predicted + + + align:start position:0% +predicted +the three-mile island case and what that + + align:start position:0% +the three-mile island case and what that + + + align:start position:0% +the three-mile island case and what that +meant was that people couldn't make good + + align:start position:0% +meant was that people couldn't make good + + + align:start position:0% +meant was that people couldn't make good +rational decisions about nuclear power + + align:start position:0% +rational decisions about nuclear power + + + align:start position:0% +rational decisions about nuclear power +in the united states + + align:start position:0% +in the united states + + + align:start position:0% +in the united states +those movies scared us to death + + align:start position:0% +those movies scared us to death + + + align:start position:0% +those movies scared us to death +uh + + align:start position:0% +uh + + + align:start position:0% +uh +and um + + align:start position:0% +and um + + + align:start position:0% +and um +what happened here + + align:start position:0% +what happened here + + + align:start position:0% +what happened here +that is very important for an ethical + + align:start position:0% +that is very important for an ethical + + + align:start position:0% +that is very important for an ethical +class a class in ethics + + align:start position:0% +class a class in ethics + + + align:start position:0% +class a class in ethics +which is also an ethical class + + align:start position:0% +which is also an ethical class + + + align:start position:0% +which is also an ethical class +i hope + + align:start position:0% +i hope + + + align:start position:0% +i hope +that + + align:start position:0% +that + + + align:start position:0% +that +when this pump went bad + + align:start position:0% +when this pump went bad + + + align:start position:0% +when this pump went bad +it was just a mechanical it was just a + + align:start position:0% +it was just a mechanical it was just a + + + align:start position:0% +it was just a mechanical it was just a +technological failure it just went bad + + align:start position:0% +technological failure it just went bad + + + align:start position:0% +technological failure it just went bad +did not pump and when it did not pump it + + align:start position:0% +did not pump and when it did not pump it + + + align:start position:0% +did not pump and when it did not pump it +caused readings to be made in the uh + + align:start position:0% +caused readings to be made in the uh + + + align:start position:0% +caused readings to be made in the uh +control room + + align:start position:0% +control room + + + align:start position:0% +control room +that were deceptive it did not say that + + align:start position:0% +that were deceptive it did not say that + + + align:start position:0% +that were deceptive it did not say that +the pumps were working it said that + + align:start position:0% +the pumps were working it said that + + + align:start position:0% +the pumps were working it said that +something was overheating + + align:start position:0% +something was overheating + + + align:start position:0% +something was overheating +and when they tried to compensate they + + align:start position:0% +and when they tried to compensate they + + + align:start position:0% +and when they tried to compensate they +did the wrong thing + + align:start position:0% +did the wrong thing + + + align:start position:0% +did the wrong thing +and this almost + + align:start position:0% +and this almost + + + align:start position:0% +and this almost +could have this could have been + + align:start position:0% +could have this could have been + + + align:start position:0% +could have this could have been +the real scare of nuclear power could + + align:start position:0% +the real scare of nuclear power could + + + align:start position:0% +the real scare of nuclear power could +have been a militant + + align:start position:0% +have been a militant + + + align:start position:0% +have been a militant +the important thing for ethics is + + align:start position:0% +the important thing for ethics is + + + align:start position:0% +the important thing for ethics is +that we could never + + align:start position:0% +that we could never + + + align:start position:0% +that we could never +assigned + + align:start position:0% +assigned + + + align:start position:0% +assigned +moral responsibility to any individual + + align:start position:0% + + + + align:start position:0% + +so the question is is there something + + align:start position:0% +so the question is is there something + + + align:start position:0% +so the question is is there something +about the way we as a culture look at + + align:start position:0% +about the way we as a culture look at + + + align:start position:0% +about the way we as a culture look at +nuclear power that is wrong and maybe + + align:start position:0% +nuclear power that is wrong and maybe + + + align:start position:0% +nuclear power that is wrong and maybe +bad + + align:start position:0% + + + + align:start position:0% + +and i would argue that that's true um i + + align:start position:0% +and i would argue that that's true um i + + + align:start position:0% +and i would argue that that's true um i +went to work for the nuclear regulatory + + align:start position:0% +went to work for the nuclear regulatory + + + align:start position:0% +went to work for the nuclear regulatory +commission june 1st + + align:start position:0% +commission june 1st + + + align:start position:0% +commission june 1st +of 1979 that was march april may june + + align:start position:0% +of 1979 that was march april may june + + + align:start position:0% +of 1979 that was march april may june +that was three months right after three + + align:start position:0% +that was three months right after three + + + align:start position:0% +that was three months right after three +mile + + align:start position:0% +mile + + + align:start position:0% +mile +hour and this is the nuclear power plant + + align:start position:0% +hour and this is the nuclear power plant + + + align:start position:0% +hour and this is the nuclear power plant +my job + + align:start position:0% +my job + + + align:start position:0% +my job +was to analyze what happens + + align:start position:0% +was to analyze what happens + + + align:start position:0% +was to analyze what happens +if a small aircraft + + align:start position:0% +if a small aircraft + + + align:start position:0% +if a small aircraft +crashes into + + align:start position:0% +crashes into + + + align:start position:0% +crashes into +uh + + align:start position:0% +uh + + + align:start position:0% +uh +containment + + align:start position:0% +containment + + + align:start position:0% +containment +structure that was in 1979 + + align:start position:0% + + + + align:start position:0% + +uh i wound up being on a consultant list + + align:start position:0% +uh i wound up being on a consultant list + + + align:start position:0% +uh i wound up being on a consultant list +at the cia + + align:start position:0% +at the cia + + + align:start position:0% +at the cia +for this kind of problem + + align:start position:0% +for this kind of problem + + + align:start position:0% +for this kind of problem +looks a lot like + + align:start position:0% +looks a lot like + + + align:start position:0% +looks a lot like +9-1-1 + + align:start position:0% + + + + align:start position:0% + +so with that then i conclude that we got + + align:start position:0% +so with that then i conclude that we got + + + align:start position:0% +so with that then i conclude that we got +some things to do + + align:start position:0% +some things to do + + + align:start position:0% +some things to do +uh + + align:start position:0% +uh + + + align:start position:0% +uh +and um + + align:start position:0% +and um + + + align:start position:0% +and um +those conclusions there + + align:start position:0% + + + + align:start position:0% + +we've made all along i need i think we + + align:start position:0% +we've made all along i need i think we + + + align:start position:0% +we've made all along i need i think we +need character development back + + align:start position:0% +need character development back + + + align:start position:0% +need character development back +i think we need to define competency + + align:start position:0% +i think we need to define competency + + + align:start position:0% +i think we need to define competency +with good character + + align:start position:0% +with good character + + + align:start position:0% +with good character +and the last part of it is that i think + + align:start position:0% +and the last part of it is that i think + + + align:start position:0% +and the last part of it is that i think +that more organizations have moral + + align:start position:0% +that more organizations have moral + + + align:start position:0% +that more organizations have moral +agency and i will prove it before this + + align:start position:0% +agency and i will prove it before this + + + align:start position:0% +agency and i will prove it before this +class is over + + align:start position:0% +class is over + + + align:start position:0% +class is over +that you've convinced me when you first + + align:start position:0% +that you've convinced me when you first + + + align:start position:0% +that you've convinced me when you first +started the class that really had a + + align:start position:0% +started the class that really had a + + + align:start position:0% +started the class that really had a +problem + + align:start position:0% + + + + align:start position:0% + +and one of the things was just talking + + align:start position:0% +and one of the things was just talking + + + align:start position:0% +and one of the things was just talking +about the internet is whether these + + align:start position:0% +about the internet is whether these + + + align:start position:0% +about the internet is whether these +complex systems of engineering design + + align:start position:0% +complex systems of engineering design + + + align:start position:0% +complex systems of engineering design +can have general agencies i've been + + align:start position:0% +can have general agencies i've been + + + align:start position:0% +can have general agencies i've been +reading a lot of stuff on network + + align:start position:0% +reading a lot of stuff on network + + + align:start position:0% +reading a lot of stuff on network +neutrality you probably know a lot more + + align:start position:0% +neutrality you probably know a lot more + + + align:start position:0% +neutrality you probably know a lot more +about it and i understand a lot more + + align:start position:0% +about it and i understand a lot more + + + align:start position:0% +about it and i understand a lot more +than i do and so it kind of made me play + + align:start position:0% +than i do and so it kind of made me play + + + align:start position:0% +than i do and so it kind of made me play +with this idea of the internet being + + align:start position:0% + + + + align:start position:0% + +well two of us will help yeah + + align:start position:0% + + + + align:start position:0% + +any questions comments + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% + + + + align:start position:0% + +a little bit outside of the + + align:start position:0% +a little bit outside of the + + + align:start position:0% +a little bit outside of the +presentation + + align:start position:0% +presentation + + + align:start position:0% +presentation +when you mention the term + + align:start position:0% +when you mention the term + + + align:start position:0% +when you mention the term +interdisciplinary + + align:start position:0% +interdisciplinary + + + align:start position:0% +interdisciplinary +this is a discussion that i've been + + align:start position:0% +this is a discussion that i've been + + + align:start position:0% +this is a discussion that i've been +having with a lot of people + + align:start position:0% +having with a lot of people + + + align:start position:0% +having with a lot of people +how would you define the difference + + align:start position:0% +how would you define the difference + + + align:start position:0% +how would you define the difference +between a multi-disciplinary + + align:start position:0% +between a multi-disciplinary + + + align:start position:0% +between a multi-disciplinary +interdisciplinary or cross-disciplinary + + align:start position:0% +interdisciplinary or cross-disciplinary + + + align:start position:0% +interdisciplinary or cross-disciplinary +yeah and transdisciplinary is a new one + + align:start position:0% +yeah and transdisciplinary is a new one + + + align:start position:0% +yeah and transdisciplinary is a new one +that i read right yeah + + align:start position:0% + + + + align:start position:0% + +yeah cross-disciplinary is when you use + + align:start position:0% +yeah cross-disciplinary is when you use + + + align:start position:0% +yeah cross-disciplinary is when you use +the tools and methods of one discipline + + align:start position:0% +the tools and methods of one discipline + + + align:start position:0% +the tools and methods of one discipline +to study the other one + + align:start position:0% +to study the other one + + + align:start position:0% +to study the other one +multidisciplinary is when you want to + + align:start position:0% +multidisciplinary is when you want to + + + align:start position:0% +multidisciplinary is when you want to +study a problem with both of the + + align:start position:0% +study a problem with both of the + + + align:start position:0% +study a problem with both of the +disciplines interact together + + align:start position:0% +disciplines interact together + + + align:start position:0% +disciplines interact together +to give you the solution + + align:start position:0% +to give you the solution + + + align:start position:0% +to give you the solution +and interdisciplinary is when + + align:start position:0% +and interdisciplinary is when + + + align:start position:0% +and interdisciplinary is when +the two interact but one has to give up + + align:start position:0% +the two interact but one has to give up + + + align:start position:0% +the two interact but one has to give up +a fundamental principle of itself in + + align:start position:0% +a fundamental principle of itself in + + + align:start position:0% +a fundamental principle of itself in +order to solve the problem in other + + align:start position:0% +order to solve the problem in other + + + align:start position:0% +order to solve the problem in other +words the two disciplines do not remain + + align:start position:0% +words the two disciplines do not remain + + + align:start position:0% +words the two disciplines do not remain +intact one of them loses something + + align:start position:0% +intact one of them loses something + + + align:start position:0% +intact one of them loses something +or is replaced by something else + + align:start position:0% + + + + align:start position:0% + +so i have not talked about + + align:start position:0% +so i have not talked about + + + align:start position:0% +so i have not talked about +transdisciplinary but only those three + + align:start position:0% +transdisciplinary but only those three + + + align:start position:0% +transdisciplinary but only those three +and that's where i define \ No newline at end of file diff --git a/zRslv221V9c.txt b/zRslv221V9c.txt new file mode 100644 index 0000000000000000000000000000000000000000..6be5a9aff80692cfa6e36f2b37c29566ac0e7715 --- /dev/null +++ b/zRslv221V9c.txt @@ -0,0 +1,1899 @@ +align:start position:0% + +how did MIT undergraduates design a + + align:start position:0% +how did MIT undergraduates design a + + + align:start position:0% +how did MIT undergraduates design a +robot to lift a small model police car + + align:start position:0% +robot to lift a small model police car + + + align:start position:0% +robot to lift a small model police car +and place it on top of a model of mi + + align:start position:0% +and place it on top of a model of mi + + + align:start position:0% +and place it on top of a model of mi +t--'s great dome calculus in this video + + align:start position:0% +t--'s great dome calculus in this video + + + align:start position:0% +t--'s great dome calculus in this video +we'll use calculus to describe the + + align:start position:0% +we'll use calculus to describe the + + + align:start position:0% +we'll use calculus to describe the +motion of rigid bodies and see how these + + align:start position:0% +motion of rigid bodies and see how these + + + align:start position:0% +motion of rigid bodies and see how these +concepts are used in the field of + + align:start position:0% +concepts are used in the field of + + + align:start position:0% +concepts are used in the field of +robotics + + align:start position:0% +robotics + + + align:start position:0% +robotics +this video is part of the derivatives + + align:start position:0% +this video is part of the derivatives + + + align:start position:0% +this video is part of the derivatives +and integrals video series derivatives + + align:start position:0% +and integrals video series derivatives + + + align:start position:0% +and integrals video series derivatives +and integrals are used to analyze the + + align:start position:0% +and integrals are used to analyze the + + + align:start position:0% +and integrals are used to analyze the +properties of a system derivatives + + align:start position:0% +properties of a system derivatives + + + align:start position:0% +properties of a system derivatives +describe local properties of systems and + + align:start position:0% +describe local properties of systems and + + + align:start position:0% +describe local properties of systems and +integrals quantify their cumulative + + align:start position:0% +integrals quantify their cumulative + + + align:start position:0% +integrals quantify their cumulative +properties hello my name is Dan Frey I'm + + align:start position:0% +properties hello my name is Dan Frey I'm + + + align:start position:0% +properties hello my name is Dan Frey I'm +a professor in the mechanical + + align:start position:0% +a professor in the mechanical + + + align:start position:0% +a professor in the mechanical +engineering department at MIT and today + + align:start position:0% +engineering department at MIT and today + + + align:start position:0% +engineering department at MIT and today +I'll be talking with you about the + + align:start position:0% +I'll be talking with you about the + + + align:start position:0% +I'll be talking with you about the +motion of rigid bodies both translation + + align:start position:0% +motion of rigid bodies both translation + + + align:start position:0% +motion of rigid bodies both translation +and rotation in order to understand this + + align:start position:0% +and rotation in order to understand this + + + align:start position:0% +and rotation in order to understand this +video you should be very comfortable + + align:start position:0% +video you should be very comfortable + + + align:start position:0% +video you should be very comfortable +with linear motion including position + + align:start position:0% +with linear motion including position + + + align:start position:0% +with linear motion including position +velocity and acceleration you'll want to + + align:start position:0% +velocity and acceleration you'll want to + + + align:start position:0% +velocity and acceleration you'll want to +know how to turn measurements in polar + + align:start position:0% +know how to turn measurements in polar + + + align:start position:0% +know how to turn measurements in polar +coordinates into measurements in + + align:start position:0% +coordinates into measurements in + + + align:start position:0% +coordinates into measurements in +Cartesian coordinates you should also + + align:start position:0% +Cartesian coordinates you should also + + + align:start position:0% +Cartesian coordinates you should also +know enough introductory calculus to + + align:start position:0% +know enough introductory calculus to + + + align:start position:0% +know enough introductory calculus to +apply the chain rule after watching this + + align:start position:0% +apply the chain rule after watching this + + + align:start position:0% +apply the chain rule after watching this +video you should be able to explain what + + align:start position:0% +video you should be able to explain what + + + align:start position:0% +video you should be able to explain what +is meant by the phrase rigid body you + + align:start position:0% +is meant by the phrase rigid body you + + + align:start position:0% +is meant by the phrase rigid body you +should also be able to describe + + align:start position:0% +should also be able to describe + + + align:start position:0% +should also be able to describe +restrictions on the motion of an object + + align:start position:0% +restrictions on the motion of an object + + + align:start position:0% +restrictions on the motion of an object +by using constraint equations finally + + align:start position:0% +by using constraint equations finally + + + align:start position:0% +by using constraint equations finally +you should be able to use derivatives + + align:start position:0% +you should be able to use derivatives + + + align:start position:0% +you should be able to use derivatives +and integrals to connect different + + align:start position:0% +and integrals to connect different + + + align:start position:0% +and integrals to connect different +mathematical descriptions of rigid body + + align:start position:0% +mathematical descriptions of rigid body + + + align:start position:0% +mathematical descriptions of rigid body +motion our primary examples today will + + align:start position:0% +motion our primary examples today will + + + align:start position:0% +motion our primary examples today will +be robots let's look at how basic ideas + + align:start position:0% +be robots let's look at how basic ideas + + + align:start position:0% +be robots let's look at how basic ideas +of motion are used in the field of + + align:start position:0% +of motion are used in the field of + + + align:start position:0% +of motion are used in the field of +Robotics here you can see some footage + + align:start position:0% +Robotics here you can see some footage + + + align:start position:0% +Robotics here you can see some footage +from a Robotics Competition at MIT the + + align:start position:0% +from a Robotics Competition at MIT the + + + align:start position:0% +from a Robotics Competition at MIT the +competition is part of a mechanical + + align:start position:0% +competition is part of a mechanical + + + align:start position:0% +competition is part of a mechanical +engineering course number two + + align:start position:0% +engineering course number two + + + align:start position:0% +engineering course number two +double-oh-seven + + align:start position:0% +double-oh-seven + + + align:start position:0% +double-oh-seven +one typical task that robots perform is + + align:start position:0% +one typical task that robots perform is + + + align:start position:0% +one typical task that robots perform is +to grab something pick it up and move it + + align:start position:0% +to grab something pick it up and move it + + + align:start position:0% +to grab something pick it up and move it +this robot uses a gripper at the end of + + align:start position:0% +this robot uses a gripper at the end of + + + align:start position:0% +this robot uses a gripper at the end of +the arm to pick up objects one of the + + align:start position:0% +the arm to pick up objects one of the + + + align:start position:0% +the arm to pick up objects one of the +difficulties in programming a robot arm + + align:start position:0% +difficulties in programming a robot arm + + + align:start position:0% +difficulties in programming a robot arm +is that we typically have no direct + + align:start position:0% +is that we typically have no direct + + + align:start position:0% +is that we typically have no direct +measurement of where that gripper is + + align:start position:0% +measurement of where that gripper is + + + align:start position:0% +measurement of where that gripper is +there's usually no convenient sort of + + align:start position:0% +there's usually no convenient sort of + + + align:start position:0% +there's usually no convenient sort of +position meter that could tell its + + align:start position:0% +position meter that could tell its + + + align:start position:0% +position meter that could tell its +location instead we might determine the + + align:start position:0% +location instead we might determine the + + + align:start position:0% +location instead we might determine the +location for the base of the arm and we + + align:start position:0% +location for the base of the arm and we + + + align:start position:0% +location for the base of the arm and we +can measure the angles for different + + align:start position:0% +can measure the angles for different + + + align:start position:0% +can measure the angles for different +parts of the arm we need to use the + + align:start position:0% +parts of the arm we need to use the + + + align:start position:0% +parts of the arm we need to use the +measurements that we can make in order + + align:start position:0% +measurements that we can make in order + + + align:start position:0% +measurements that we can make in order +to determine the location of the gripper + + align:start position:0% +to determine the location of the gripper + + + align:start position:0% +to determine the location of the gripper +he's got to let go of the police car + + align:start position:0% +he's got to let go of the police car + + + align:start position:0% +he's got to let go of the police car +completely + + align:start position:0% +completely + + + align:start position:0% +completely +or to score is it balanced properly + + align:start position:0% +or to score is it balanced properly + + + align:start position:0% +or to score is it balanced properly +still six seconds five four he did like + + align:start position:0% +still six seconds five four he did like + + + align:start position:0% +still six seconds five four he did like +oh he did like oh he did it fifteen will + + align:start position:0% +oh he did like oh he did it fifteen will + + + align:start position:0% +oh he did like oh he did it fifteen will +gone gram this is made easier by the + + align:start position:0% +gone gram this is made easier by the + + + align:start position:0% +gone gram this is made easier by the +concept of a rigid body rigid bodies can + + align:start position:0% +concept of a rigid body rigid bodies can + + + align:start position:0% +concept of a rigid body rigid bodies can +translate and rotate but they do not + + align:start position:0% +translate and rotate but they do not + + + align:start position:0% +translate and rotate but they do not +Bend stretch or twist in mathematical + + align:start position:0% +Bend stretch or twist in mathematical + + + align:start position:0% +Bend stretch or twist in mathematical +terms the distance between any two + + align:start position:0% +terms the distance between any two + + + align:start position:0% +terms the distance between any two +points in the object does not change + + align:start position:0% +points in the object does not change + + + align:start position:0% +points in the object does not change +rigid bodies are idealization to + + align:start position:0% +rigid bodies are idealization to + + + align:start position:0% +rigid bodies are idealization to +simplify our work we imagine that we are + + align:start position:0% +simplify our work we imagine that we are + + + align:start position:0% +simplify our work we imagine that we are +working with objects that do not deform + + align:start position:0% +working with objects that do not deform + + + align:start position:0% +working with objects that do not deform +this idealization works best when the + + align:start position:0% +this idealization works best when the + + + align:start position:0% +this idealization works best when the +object only experiences low amounts of + + align:start position:0% +object only experiences low amounts of + + + align:start position:0% +object only experiences low amounts of +force higher amounts of force can lead + + align:start position:0% +force higher amounts of force can lead + + + align:start position:0% +force higher amounts of force can lead +to objects deforming or breaking + + align:start position:0% +to objects deforming or breaking + + + align:start position:0% +to objects deforming or breaking +depending on the object the robot we saw + + align:start position:0% +depending on the object the robot we saw + + + align:start position:0% +depending on the object the robot we saw +earlier is a good example of a rigid + + align:start position:0% +earlier is a good example of a rigid + + + align:start position:0% +earlier is a good example of a rigid +body you can see in this video that as + + align:start position:0% +body you can see in this video that as + + + align:start position:0% +body you can see in this video that as +our robot moves its pieces do not bend + + align:start position:0% +our robot moves its pieces do not bend + + + align:start position:0% +our robot moves its pieces do not bend +or distort noticeably so we can treat + + align:start position:0% +or distort noticeably so we can treat + + + align:start position:0% +or distort noticeably so we can treat +each piece as a rigid body we could use + + align:start position:0% +each piece as a rigid body we could use + + + align:start position:0% +each piece as a rigid body we could use +the definition of a rigid body to help + + align:start position:0% +the definition of a rigid body to help + + + align:start position:0% +the definition of a rigid body to help +us determine the location of points on + + align:start position:0% +us determine the location of points on + + + align:start position:0% +us determine the location of points on +that robot this robot on the other hand + + align:start position:0% +that robot this robot on the other hand + + + align:start position:0% +that robot this robot on the other hand +has a less sturdy frame you can see the + + align:start position:0% +has a less sturdy frame you can see the + + + align:start position:0% +has a less sturdy frame you can see the +arm flex as the robot moves we might not + + align:start position:0% +arm flex as the robot moves we might not + + + align:start position:0% +arm flex as the robot moves we might not +want to treat this arm as a rigid body + + align:start position:0% +want to treat this arm as a rigid body + + + align:start position:0% +want to treat this arm as a rigid body +let's try to solve a problem involving a + + align:start position:0% +let's try to solve a problem involving a + + + align:start position:0% +let's try to solve a problem involving a +rigid body here is a very simple robot + + align:start position:0% +rigid body here is a very simple robot + + + align:start position:0% +rigid body here is a very simple robot +arm it has a joint on the left that can + + align:start position:0% +arm it has a joint on the left that can + + + align:start position:0% +arm it has a joint on the left that can +tilt up and down and a piston that can + + align:start position:0% +tilt up and down and a piston that can + + + align:start position:0% +tilt up and down and a piston that can +extend its arm in addition this part of + + align:start position:0% +extend its arm in addition this part of + + + align:start position:0% +extend its arm in addition this part of +the piston can be considered a rigid + + align:start position:0% +the piston can be considered a rigid + + + align:start position:0% +the piston can be considered a rigid +body so its length will be a constant + + align:start position:0% +body so its length will be a constant + + + align:start position:0% +body so its length will be a constant +here is a task for you describe the + + align:start position:0% +here is a task for you describe the + + + align:start position:0% +here is a task for you describe the +acceleration of the gripper at the end + + align:start position:0% +acceleration of the gripper at the end + + + align:start position:0% +acceleration of the gripper at the end +of the arm first set the origin for your + + align:start position:0% +of the arm first set the origin for your + + + align:start position:0% +of the arm first set the origin for your +coordinate system then write an + + align:start position:0% +coordinate system then write an + + + align:start position:0% +coordinate system then write an +expression for the X&Y position of the + + align:start position:0% +expression for the X&Y position of the + + + align:start position:0% +expression for the X&Y position of the +gripper in terms of the quantities shown + + align:start position:0% +gripper in terms of the quantities shown + + + align:start position:0% +gripper in terms of the quantities shown +here once you have that position use + + align:start position:0% +here once you have that position use + + + align:start position:0% +here once you have that position use +derivatives to find the velocity and the + + align:start position:0% +derivatives to find the velocity and the + + + align:start position:0% +derivatives to find the velocity and the +acceleration of the gripper + + align:start position:0% +acceleration of the gripper + + + align:start position:0% +acceleration of the gripper +pause the video here to carry out your + + align:start position:0% +pause the video here to carry out your + + + align:start position:0% +pause the video here to carry out your +calculations let's take a look at the + + align:start position:0% +calculations let's take a look at the + + + align:start position:0% +calculations let's take a look at the +answer first we need to choose an origin + + align:start position:0% +answer first we need to choose an origin + + + align:start position:0% +answer first we need to choose an origin +let's choose an arbitrary location as + + align:start position:0% +let's choose an arbitrary location as + + + align:start position:0% +let's choose an arbitrary location as +the origin of our coordinate system our + + align:start position:0% +the origin of our coordinate system our + + + align:start position:0% +the origin of our coordinate system our +robots joint may be moving so we will + + align:start position:0% +robots joint may be moving so we will + + + align:start position:0% +robots joint may be moving so we will +use a pair of functions X sub J of time + + align:start position:0% +use a pair of functions X sub J of time + + + align:start position:0% +use a pair of functions X sub J of time +and y sub J of time to describe its + + align:start position:0% +and y sub J of time to describe its + + + align:start position:0% +and y sub J of time to describe its +location X sub J will be the horizontal + + align:start position:0% +location X sub J will be the horizontal + + + align:start position:0% +location X sub J will be the horizontal +distance from our origin to the joint + + align:start position:0% +distance from our origin to the joint + + + align:start position:0% +distance from our origin to the joint +and Y sub J will be the vertical + + align:start position:0% +and Y sub J will be the vertical + + + align:start position:0% +and Y sub J will be the vertical +distance we can use derivatives of these + + align:start position:0% +distance we can use derivatives of these + + + align:start position:0% +distance we can use derivatives of these +functions to describe any relative + + align:start position:0% +functions to describe any relative + + + align:start position:0% +functions to describe any relative +movement that the joint has when + + align:start position:0% +movement that the joint has when + + + align:start position:0% +movement that the joint has when +compared with our coordinate system such + + align:start position:0% +compared with our coordinate system such + + + align:start position:0% +compared with our coordinate system such +as velocity or acceleration + + align:start position:0% +as velocity or acceleration + + + align:start position:0% +as velocity or acceleration +this slide shows just the X components + + align:start position:0% +this slide shows just the X components + + + align:start position:0% +this slide shows just the X components +of the answer with the value X sub J + + align:start position:0% +of the answer with the value X sub J + + + align:start position:0% +of the answer with the value X sub J +indicating the location of the joint you + + align:start position:0% +indicating the location of the joint you + + + align:start position:0% +indicating the location of the joint you +can see that the expressions can easily + + align:start position:0% +can see that the expressions can easily + + + align:start position:0% +can see that the expressions can easily +become complicated + + align:start position:0% +become complicated + + + align:start position:0% +become complicated +if both s and theta change at the same + + align:start position:0% +if both s and theta change at the same + + + align:start position:0% +if both s and theta change at the same +time one reason that we want to know the + + align:start position:0% +time one reason that we want to know the + + + align:start position:0% +time one reason that we want to know the +acceleration is because some objects + + align:start position:0% +acceleration is because some objects + + + align:start position:0% +acceleration is because some objects +respond poorly to a high acceleration + + align:start position:0% +respond poorly to a high acceleration + + + align:start position:0% +respond poorly to a high acceleration +here you can see a different sort of + + align:start position:0% +here you can see a different sort of + + + align:start position:0% +here you can see a different sort of +robot arm lifting a car instead of a + + align:start position:0% +robot arm lifting a car instead of a + + + align:start position:0% +robot arm lifting a car instead of a +gripper these two robots use a forklift + + align:start position:0% +gripper these two robots use a forklift + + + align:start position:0% +gripper these two robots use a forklift +design their arms must move very gently + + align:start position:0% +design their arms must move very gently + + + align:start position:0% +design their arms must move very gently +especially as they slow down or the car + + align:start position:0% +especially as they slow down or the car + + + align:start position:0% +especially as they slow down or the car +will fall off the arms are capable of + + align:start position:0% +will fall off the arms are capable of + + + align:start position:0% +will fall off the arms are capable of +moving more quickly but the robots + + align:start position:0% +moving more quickly but the robots + + + align:start position:0% +moving more quickly but the robots +designers have programmed it to use a + + align:start position:0% +designers have programmed it to use a + + + align:start position:0% +designers have programmed it to use a +lower acceleration this leads us to a + + align:start position:0% +lower acceleration this leads us to a + + + align:start position:0% +lower acceleration this leads us to a +discussion of constraints this section + + align:start position:0% +discussion of constraints this section + + + align:start position:0% +discussion of constraints this section +will have a few examples as well as + + align:start position:0% +will have a few examples as well as + + + align:start position:0% +will have a few examples as well as +several opportunities for you to + + align:start position:0% +several opportunities for you to + + + align:start position:0% +several opportunities for you to +practice be ready to pause the video + + align:start position:0% +practice be ready to pause the video + + + align:start position:0% +practice be ready to pause the video +constraints are any sort of restriction + + align:start position:0% +constraints are any sort of restriction + + + align:start position:0% +constraints are any sort of restriction +on a situation when they can be + + align:start position:0% +on a situation when they can be + + + align:start position:0% +on a situation when they can be +expressed mathematically we refer to + + align:start position:0% +expressed mathematically we refer to + + + align:start position:0% +expressed mathematically we refer to +equations of constraint these describe + + align:start position:0% +equations of constraint these describe + + + align:start position:0% +equations of constraint these describe +the physical connection between two or + + align:start position:0% +the physical connection between two or + + + align:start position:0% +the physical connection between two or +more rigid bodies constraint equations + + align:start position:0% +more rigid bodies constraint equations + + + align:start position:0% +more rigid bodies constraint equations +are useful because they link one + + align:start position:0% +are useful because they link one + + + align:start position:0% +are useful because they link one +variable to another in a way that + + align:start position:0% +variable to another in a way that + + + align:start position:0% +variable to another in a way that +reduces the total number of variables in + + align:start position:0% +reduces the total number of variables in + + + align:start position:0% +reduces the total number of variables in +a problem this helps to make otherwise + + align:start position:0% +a problem this helps to make otherwise + + + align:start position:0% +a problem this helps to make otherwise +impossible problems solvable constraint + + align:start position:0% +impossible problems solvable constraint + + + align:start position:0% +impossible problems solvable constraint +equations are used throughout physics + + align:start position:0% +equations are used throughout physics + + + align:start position:0% +equations are used throughout physics +and the + + align:start position:0% +and the + + + align:start position:0% +and the +engineering some fields refer to a + + align:start position:0% +engineering some fields refer to a + + + align:start position:0% +engineering some fields refer to a +similar idea called degree of freedom + + align:start position:0% +similar idea called degree of freedom + + + align:start position:0% +similar idea called degree of freedom +analysis here is a classic example of a + + align:start position:0% +analysis here is a classic example of a + + + align:start position:0% +analysis here is a classic example of a +situation with a constraint the car on + + align:start position:0% +situation with a constraint the car on + + + align:start position:0% +situation with a constraint the car on +this rollercoaster + + align:start position:0% +this rollercoaster + + + align:start position:0% +this rollercoaster +cannot leave the tracks if the track is + + align:start position:0% +cannot leave the tracks if the track is + + + align:start position:0% +cannot leave the tracks if the track is +circular we can use the equation for a + + align:start position:0% +circular we can use the equation for a + + + align:start position:0% +circular we can use the equation for a +circle to constrain our movement we can + + align:start position:0% +circle to constrain our movement we can + + + align:start position:0% +circle to constrain our movement we can +use this to reduce the number of + + align:start position:0% +use this to reduce the number of + + + align:start position:0% +use this to reduce the number of +variables in our equations for the + + align:start position:0% +variables in our equations for the + + + align:start position:0% +variables in our equations for the +position of the roller-coaster rather + + align:start position:0% +position of the roller-coaster rather + + + align:start position:0% +position of the roller-coaster rather +than an equation in X and y we could + + align:start position:0% +than an equation in X and y we could + + + align:start position:0% +than an equation in X and y we could +have equations in just X or just Y we + + align:start position:0% +have equations in just X or just Y we + + + align:start position:0% +have equations in just X or just Y we +could also use constraints that involve + + align:start position:0% +could also use constraints that involve + + + align:start position:0% +could also use constraints that involve +the distance along the track or another + + align:start position:0% +the distance along the track or another + + + align:start position:0% +the distance along the track or another +sensible measurement for the situation + + align:start position:0% +sensible measurement for the situation + + + align:start position:0% +sensible measurement for the situation +we're investigating it's important to + + align:start position:0% +we're investigating it's important to + + + align:start position:0% +we're investigating it's important to +note that constraints being giving up + + align:start position:0% +note that constraints being giving up + + + align:start position:0% +note that constraints being giving up +some freedom in our variables in our + + align:start position:0% +some freedom in our variables in our + + + align:start position:0% +some freedom in our variables in our +example we can only specify X or Y not + + align:start position:0% +example we can only specify X or Y not + + + align:start position:0% +example we can only specify X or Y not +both once we choose a value for X there + + align:start position:0% +both once we choose a value for X there + + + align:start position:0% +both once we choose a value for X there +are only two values of Y that will work + + align:start position:0% +are only two values of Y that will work + + + align:start position:0% +are only two values of Y that will work +here's a situation where you can find + + align:start position:0% +here's a situation where you can find + + + align:start position:0% +here's a situation where you can find +the equation of constraint a cart is + + align:start position:0% +the equation of constraint a cart is + + + align:start position:0% +the equation of constraint a cart is +being pulled across a flat surface and + + align:start position:0% +being pulled across a flat surface and + + + align:start position:0% +being pulled across a flat surface and +the wheels turn without slipping + + align:start position:0% +the wheels turn without slipping + + + align:start position:0% +the wheels turn without slipping +effectively the wheel is constrained to + + align:start position:0% +effectively the wheel is constrained to + + + align:start position:0% +effectively the wheel is constrained to +move only by rolling and not in any + + align:start position:0% +move only by rolling and not in any + + + align:start position:0% +move only by rolling and not in any +other way no lifting up no sliding no + + align:start position:0% +other way no lifting up no sliding no + + + align:start position:0% +other way no lifting up no sliding no +peeling out can you find an equation + + align:start position:0% +peeling out can you find an equation + + + align:start position:0% +peeling out can you find an equation +that connects X the distance the cart + + align:start position:0% +that connects X the distance the cart + + + align:start position:0% +that connects X the distance the cart +has moved to theta the amount that the + + align:start position:0% +has moved to theta the amount that the + + + align:start position:0% +has moved to theta the amount that the +wheels have turned pause the video here + + align:start position:0% +wheels have turned pause the video here + + + align:start position:0% +wheels have turned pause the video here +to discuss this in class + + align:start position:0% + + + + align:start position:0% + +here is an arm that is fairly complex it + + align:start position:0% +here is an arm that is fairly complex it + + + align:start position:0% +here is an arm that is fairly complex it +has many joints pause the video and + + align:start position:0% +has many joints pause the video and + + + align:start position:0% +has many joints pause the video and +write down the variables and constants + + align:start position:0% +write down the variables and constants + + + align:start position:0% +write down the variables and constants +you would use for this robot there are + + align:start position:0% +you would use for this robot there are + + + align:start position:0% +you would use for this robot there are +three separate angles that must be + + align:start position:0% +three separate angles that must be + + + align:start position:0% +three separate angles that must be +recorded as well as the extension of the + + align:start position:0% +recorded as well as the extension of the + + + align:start position:0% +recorded as well as the extension of the +arm + + align:start position:0% +arm + + + align:start position:0% +arm +there are also three pieces of constant + + align:start position:0% +there are also three pieces of constant + + + align:start position:0% +there are also three pieces of constant +length now we have an opportunity to + + align:start position:0% +length now we have an opportunity to + + + align:start position:0% +length now we have an opportunity to +describe a constraint in a complex + + align:start position:0% +describe a constraint in a complex + + + align:start position:0% +describe a constraint in a complex +situation we could choose for example to + + align:start position:0% +situation we could choose for example to + + + align:start position:0% +situation we could choose for example to +constrain the motion of the arm to just + + align:start position:0% +constrain the motion of the arm to just + + + align:start position:0% +constrain the motion of the arm to just +the horizontal direction because there + + align:start position:0% +the horizontal direction because there + + + align:start position:0% +the horizontal direction because there +are so many variables in this situation + + align:start position:0% +are so many variables in this situation + + + align:start position:0% +are so many variables in this situation +there are many possible ways to satisfy + + align:start position:0% +there are many possible ways to satisfy + + + align:start position:0% +there are many possible ways to satisfy +the constraint write an expression for + + align:start position:0% +the constraint write an expression for + + + align:start position:0% +the constraint write an expression for +just the vertical position in the + + align:start position:0% +just the vertical position in the + + + align:start position:0% +just the vertical position in the +gripper in terms of the quantities shown + + align:start position:0% +gripper in terms of the quantities shown + + + align:start position:0% +gripper in terms of the quantities shown +once you have done that answer this + + align:start position:0% +once you have done that answer this + + + align:start position:0% +once you have done that answer this +question how might we move the gripper + + align:start position:0% +question how might we move the gripper + + + align:start position:0% +question how might we move the gripper +in just the horizontal direction you + + align:start position:0% +in just the horizontal direction you + + + align:start position:0% +in just the horizontal direction you +should come up with at least two ways + + align:start position:0% +should come up with at least two ways + + + align:start position:0% +should come up with at least two ways +that we could do this and describe them + + align:start position:0% +that we could do this and describe them + + + align:start position:0% +that we could do this and describe them +mathematically your teacher will then + + align:start position:0% +mathematically your teacher will then + + + align:start position:0% +mathematically your teacher will then +lead the class in a discussion of your + + align:start position:0% +lead the class in a discussion of your + + + align:start position:0% +lead the class in a discussion of your +answers pause the video here to do this + + align:start position:0% + + + + align:start position:0% + +here is a simulation of a Hydra bot + + align:start position:0% +here is a simulation of a Hydra bot + + + align:start position:0% +here is a simulation of a Hydra bot +doing exactly what you just calculated + + align:start position:0% +doing exactly what you just calculated + + + align:start position:0% +doing exactly what you just calculated +moving one end horizontally you can see + + align:start position:0% +moving one end horizontally you can see + + + align:start position:0% +moving one end horizontally you can see +that it matches up quite well with our + + align:start position:0% +that it matches up quite well with our + + + align:start position:0% +that it matches up quite well with our +hypothetical robot examine its motion + + align:start position:0% +hypothetical robot examine its motion + + + align:start position:0% +hypothetical robot examine its motion +closely is this one of the motions you + + align:start position:0% +closely is this one of the motions you + + + align:start position:0% +closely is this one of the motions you +described are there extra constraints + + align:start position:0% +described are there extra constraints + + + align:start position:0% +described are there extra constraints +present here what freedom of motion did + + align:start position:0% +present here what freedom of motion did + + + align:start position:0% +present here what freedom of motion did +we give up by making our choice let's + + align:start position:0% +we give up by making our choice let's + + + align:start position:0% +we give up by making our choice let's +review today you use derivatives to find + + align:start position:0% +review today you use derivatives to find + + + align:start position:0% +review today you use derivatives to find +the velocity and acceleration of an + + align:start position:0% +the velocity and acceleration of an + + + align:start position:0% +the velocity and acceleration of an +object based on its position you also + + align:start position:0% +object based on its position you also + + + align:start position:0% +object based on its position you also +learned the definition of a rigid body + + align:start position:0% +learned the definition of a rigid body + + + align:start position:0% +learned the definition of a rigid body +that it does not bend or stretch when + + align:start position:0% +that it does not bend or stretch when + + + align:start position:0% +that it does not bend or stretch when +forces applied finally you saw the + + align:start position:0% +forces applied finally you saw the + + + align:start position:0% +forces applied finally you saw the +constraint equations can reduce the + + align:start position:0% +constraint equations can reduce the + + + align:start position:0% +constraint equations can reduce the +total number of equations in a system + + align:start position:0% +total number of equations in a system + + + align:start position:0% +total number of equations in a system +thus making the problems easier to solve + + align:start position:0% +thus making the problems easier to solve + + + align:start position:0% +thus making the problems easier to solve +I hope you enjoyed seeing some + + align:start position:0% +I hope you enjoyed seeing some + + + align:start position:0% +I hope you enjoyed seeing some +applications of basic motion concepts + + align:start position:0% +applications of basic motion concepts + + + align:start position:0% +applications of basic motion concepts +good luck in your further investigations + + align:start position:0% +good luck in your further investigations + + + align:start position:0% +good luck in your further investigations +of physics and engineering \ No newline at end of file diff --git a/zVzixXOtq7Y.txt b/zVzixXOtq7Y.txt new file mode 100644 index 0000000000000000000000000000000000000000..83aef0c4549705770b18d00ebf1d73ba83cb0d6e --- /dev/null +++ b/zVzixXOtq7Y.txt @@ -0,0 +1,1283 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT OpenCourseWare continue to + + align:start position:0% +will help MIT OpenCourseWare continue to + + + align:start position:0% +will help MIT OpenCourseWare continue to +offer high quality educational resources + + align:start position:0% +offer high quality educational resources + + + align:start position:0% +offer high quality educational resources +for free to make a donation or view + + align:start position:0% +for free to make a donation or view + + + align:start position:0% +for free to make a donation or view +additional materials from hundreds of + + align:start position:0% +additional materials from hundreds of + + + align:start position:0% +additional materials from hundreds of +MIT courses visit MIT opencourseware at + + align:start position:0% +MIT courses visit MIT opencourseware at + + + align:start position:0% +MIT courses visit MIT opencourseware at +ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +so the first thing we're going to do is + + align:start position:0% +so the first thing we're going to do is + + + align:start position:0% +so the first thing we're going to do is +a power module and it's important that + + align:start position:0% +a power module and it's important that + + + align:start position:0% +a power module and it's important that +when you're trying to get draw power + + align:start position:0% +when you're trying to get draw power + + + align:start position:0% +when you're trying to get draw power +from any source even a battery or + + align:start position:0% +from any source even a battery or + + + align:start position:0% +from any source even a battery or +anything like that that you try to match + + align:start position:0% +anything like that that you try to match + + + align:start position:0% +anything like that that you try to match +or you want to Matt draw the maximum + + align:start position:0% +or you want to Matt draw the maximum + + + align:start position:0% +or you want to Matt draw the maximum +amount of power you need to have the + + align:start position:0% +amount of power you need to have the + + + align:start position:0% +amount of power you need to have the +right load on it so we're going to try + + align:start position:0% +right load on it so we're going to try + + + align:start position:0% +right load on it so we're going to try +to figure out experimentally what the + + align:start position:0% +to figure out experimentally what the + + + align:start position:0% +to figure out experimentally what the +right load is for this solar panel and + + align:start position:0% +right load is for this solar panel and + + + align:start position:0% +right load is for this solar panel and +the way you do that is you you hook up a + + align:start position:0% +the way you do that is you you hook up a + + + align:start position:0% +the way you do that is you you hook up a +resistor or a potentiometer to a in a + + align:start position:0% +resistor or a potentiometer to a in a + + + align:start position:0% +resistor or a potentiometer to a in a +closed circuit around this and first to + + align:start position:0% +closed circuit around this and first to + + + align:start position:0% +closed circuit around this and first to +measure the resistance of it then you + + align:start position:0% +measure the resistance of it then you + + + align:start position:0% +measure the resistance of it then you +hook a hook this up in a closed circuit + + align:start position:0% +hook a hook this up in a closed circuit + + + align:start position:0% +hook a hook this up in a closed circuit +and measure the voltage drop across it + + align:start position:0% +and measure the voltage drop across it + + + align:start position:0% +and measure the voltage drop across it +and you can calculate power from a V + + align:start position:0% +and you can calculate power from a V + + + align:start position:0% +and you can calculate power from a V +squared over R and so you just do that + + align:start position:0% +squared over R and so you just do that + + + align:start position:0% +squared over R and so you just do that +for a bunch of different resistances + + align:start position:0% +for a bunch of different resistances + + + align:start position:0% +for a bunch of different resistances +just changing this and you should be + + align:start position:0% +just changing this and you should be + + + align:start position:0% +just changing this and you should be +able to get a graph that goes up and + + align:start position:0% +able to get a graph that goes up and + + + align:start position:0% +able to get a graph that goes up and +then down and if your graph power versus + + align:start position:0% +then down and if your graph power versus + + + align:start position:0% +then down and if your graph power versus +resistance and based off of that you can + + align:start position:0% +resistance and based off of that you can + + + align:start position:0% +resistance and based off of that you can +figure out what the appropriate load to + + align:start position:0% +figure out what the appropriate load to + + + align:start position:0% +figure out what the appropriate load to +place on it is and still generate a + + align:start position:0% +place on it is and still generate a + + + align:start position:0% +place on it is and still generate a +power curve for that again make sure you + + align:start position:0% +power curve for that again make sure you + + + align:start position:0% +power curve for that again make sure you +don't measure the resistance when it's + + align:start position:0% +don't measure the resistance when it's + + + align:start position:0% +don't measure the resistance when it's +hooked up because you're going to fry + + align:start position:0% +hooked up because you're going to fry + + + align:start position:0% +hooked up because you're going to fry +the voltmeter and then the second thing + + align:start position:0% +the voltmeter and then the second thing + + + align:start position:0% +the voltmeter and then the second thing +we're going to have you do is optimize + + align:start position:0% +we're going to have you do is optimize + + + align:start position:0% +we're going to have you do is optimize +the angle so you want to put the solar + + align:start position:0% +the angle so you want to put the solar + + + align:start position:0% +the angle so you want to put the solar +panel at different angles both in this + + align:start position:0% +panel at different angles both in this + + + align:start position:0% +panel at different angles both in this +direction and in this direction and + + align:start position:0% +direction and in this direction and + + + align:start position:0% +direction and in this direction and +measure for a variety of angles what the + + align:start position:0% +measure for a variety of angles what the + + + align:start position:0% +measure for a variety of angles what the +power output it is and so for that you + + align:start position:0% +power output it is and so for that you + + + align:start position:0% +power output it is and so for that you +can just have choose a resistance with + + align:start position:0% +can just have choose a resistance with + + + align:start position:0% +can just have choose a resistance with +the potentiometer and then measure + + align:start position:0% +the potentiometer and then measure + + + align:start position:0% +the potentiometer and then measure +voltage and get power that way and then + + align:start position:0% +voltage and get power that way and then + + + align:start position:0% +voltage and get power that way and then +I have protractor somewhere yeah or + + align:start position:0% + + + + align:start position:0% + +what close enough yeah and so you can + + align:start position:0% +what close enough yeah and so you can + + + align:start position:0% +what close enough yeah and so you can +use that to measure the angle of the + + align:start position:0% +use that to measure the angle of the + + + align:start position:0% +use that to measure the angle of the +solar panel and when you're doing this I + + align:start position:0% +solar panel and when you're doing this I + + + align:start position:0% +solar panel and when you're doing this I +want you to take for the two for the + + align:start position:0% +want you to take for the two for the + + + align:start position:0% +want you to take for the two for the +angle ones and the shading once I want + + align:start position:0% +angle ones and the shading once I want + + + align:start position:0% +angle ones and the shading once I want +you to take at least 10 data points and + + align:start position:0% +you to take at least 10 data points and + + + align:start position:0% +you to take at least 10 data points and +for the voltage one I want you to take + + align:start position:0% +for the voltage one I want you to take + + + align:start position:0% +for the voltage one I want you to take +at least 15 data points for different + + align:start position:0% +at least 15 data points for different + + + align:start position:0% +at least 15 data points for different +resistances empowers and then the last + + align:start position:0% +resistances empowers and then the last + + + align:start position:0% +resistances empowers and then the last +thing we're going to look at is how + + align:start position:0% +thing we're going to look at is how + + + align:start position:0% +thing we're going to look at is how +shading the solar panel affects the + + align:start position:0% +shading the solar panel affects the + + + align:start position:0% +shading the solar panel affects the +energy being outputted by it and in this + + align:start position:0% +energy being outputted by it and in this + + + align:start position:0% +energy being outputted by it and in this +case I want you to if you look at these + + align:start position:0% +case I want you to if you look at these + + + align:start position:0% +case I want you to if you look at these +solar panels each of these long things + + align:start position:0% +solar panels each of these long things + + + align:start position:0% +solar panels each of these long things +is an individual cell and they're wired + + align:start position:0% +is an individual cell and they're wired + + + align:start position:0% +is an individual cell and they're wired +in series so I want you to shade the + + align:start position:0% +in series so I want you to shade the + + + align:start position:0% +in series so I want you to shade the +solar panel going down this way and then + + align:start position:0% +solar panel going down this way and then + + + align:start position:0% +solar panel going down this way and then +going across this way and just measure + + align:start position:0% +going across this way and just measure + + + align:start position:0% +going across this way and just measure +the surface area of the exposed solar + + align:start position:0% +the surface area of the exposed solar + + + align:start position:0% +the surface area of the exposed solar +panel and then food for that one just + + align:start position:0% +panel and then food for that one just + + + align:start position:0% +panel and then food for that one just +choose the angle that you like and + + align:start position:0% +choose the angle that you like and + + + align:start position:0% +choose the angle that you like and +choose a resistance that you like and + + align:start position:0% +choose a resistance that you like and + + + align:start position:0% +choose a resistance that you like and +then measure power being outputted by + + align:start position:0% +then measure power being outputted by + + + align:start position:0% +then measure power being outputted by +that + + align:start position:0% + + + + align:start position:0% + +and as you can see it's kind of annoying + + align:start position:0% +and as you can see it's kind of annoying + + + align:start position:0% +and as you can see it's kind of annoying +to attach wires to other wires in the + + align:start position:0% +to attach wires to other wires in the + + + align:start position:0% +to attach wires to other wires in the +developing world especially if you don't + + align:start position:0% +developing world especially if you don't + + + align:start position:0% +developing world especially if you don't +have solder in techniques or anything + + align:start position:0% +have solder in techniques or anything + + + align:start position:0% +have solder in techniques or anything +like that easily available so there are + + align:start position:0% +like that easily available so there are + + + align:start position:0% +like that easily available so there are +a lot of different ways of attaching + + align:start position:0% +a lot of different ways of attaching + + + align:start position:0% +a lot of different ways of attaching +them together a lot of times you the way + + align:start position:0% +them together a lot of times you the way + + + align:start position:0% +them together a lot of times you the way +you'll see people wire things it's just + + align:start position:0% +you'll see people wire things it's just + + + align:start position:0% +you'll see people wire things it's just +taking two wires and twisting them + + align:start position:0% +taking two wires and twisting them + + + align:start position:0% +taking two wires and twisting them +together and I neither works as a short + + align:start position:0% +together and I neither works as a short + + + align:start position:0% +together and I neither works as a short +term solution but you'll see entire + + align:start position:0% +term solution but you'll see entire + + + align:start position:0% +term solution but you'll see entire +system's rigged up that way and yeah + + align:start position:0% +system's rigged up that way and yeah + + + align:start position:0% +system's rigged up that way and yeah +it's not particularly good + + align:start position:0% + + + + align:start position:0% + +so you are you're comfortable + + align:start position:0% +so you are you're comfortable + + + align:start position:0% +so you are you're comfortable +calculating power given this we just do + + align:start position:0% +calculating power given this we just do + + + align:start position:0% +calculating power given this we just do +this right over our 19 + + align:start position:0% + + + + align:start position:0% + +we're not i'm not going seven yeah right + + align:start position:0% +we're not i'm not going seven yeah right + + + align:start position:0% +we're not i'm not going seven yeah right +so go to Twitter go about 20 yeah it's + + align:start position:0% +so go to Twitter go about 20 yeah it's + + + align:start position:0% +so go to Twitter go about 20 yeah it's +gonna + + align:start position:0% + + + + align:start position:0% + +they saw our panel outputs 15 watts and + + align:start position:0% +they saw our panel outputs 15 watts and + + + align:start position:0% +they saw our panel outputs 15 watts and +most of like the tiny resistors you see + + align:start position:0% +most of like the tiny resistors you see + + + align:start position:0% +most of like the tiny resistors you see +are rated for underwater have one so if + + align:start position:0% +are rated for underwater have one so if + + + align:start position:0% +are rated for underwater have one so if +you hook them up to this they were just + + align:start position:0% +you hook them up to this they were just + + + align:start position:0% +you hook them up to this they were just +thrown out or get like super hot burning + + align:start position:0% +thrown out or get like super hot burning + + + align:start position:0% +thrown out or get like super hot burning +so this one's rated for nothing like + + align:start position:0% +so this one's rated for nothing like + + + align:start position:0% +so this one's rated for nothing like +point where point for ya and so change + + align:start position:0% +point where point for ya and so change + + + align:start position:0% +point where point for ya and so change +your angle relative to Point into the + + align:start position:0% +your angle relative to Point into the + + + align:start position:0% +your angle relative to Point into the +Sun would that make sense you be like + + align:start position:0% +Sun would that make sense you be like + + + align:start position:0% +Sun would that make sense you be like +yes you just like your son is there then + + align:start position:0% +yes you just like your son is there then + + + align:start position:0% +yes you just like your son is there then +like kind of tilt your panel here and an + + align:start position:0% +like kind of tilt your panel here and an + + + align:start position:0% +like kind of tilt your panel here and an +angle towards the Sun like kind of like + + align:start position:0% +angle towards the Sun like kind of like + + + align:start position:0% +angle towards the Sun like kind of like +that that make sense like the Sun is + + align:start position:0% +that that make sense like the Sun is + + + align:start position:0% +that that make sense like the Sun is +there + + align:start position:0% + + + + align:start position:0% + +understand accord and I want to really + + align:start position:0% +understand accord and I want to really + + + align:start position:0% +understand accord and I want to really +battery out of the way too because I + + align:start position:0% +battery out of the way too because I + + + align:start position:0% +battery out of the way too because I +think it might officiating so we're + + align:start position:0% +think it might officiating so we're + + + align:start position:0% +think it might officiating so we're +gonna use it kind of our thang sounds + + align:start position:0% +gonna use it kind of our thang sounds + + + align:start position:0% +gonna use it kind of our thang sounds +really yeah + + align:start position:0% + + + + align:start position:0% + +can you move it + + align:start position:0% +can you move it + + + align:start position:0% +can you move it +the manger scenes + + align:start position:0% + + + + align:start position:0% + +okay and so now we flip it 90 degrees + + align:start position:0% +okay and so now we flip it 90 degrees + + + align:start position:0% +okay and so now we flip it 90 degrees +and then do the exact same thing a + + align:start position:0% +and then do the exact same thing a + + + align:start position:0% +and then do the exact same thing a +figure on political metric say it's 95 + + align:start position:0% + + + + align:start position:0% + +Oh + + align:start position:0% + + + + align:start position:0% + +this lab is just for fun so I gave + + align:start position:0% +this lab is just for fun so I gave + + + align:start position:0% +this lab is just for fun so I gave +people the option of either making + + align:start position:0% +people the option of either making + + + align:start position:0% +people the option of either making +something cool if you're feeling + + align:start position:0% +something cool if you're feeling + + + align:start position:0% +something cool if you're feeling +creative or just doing each operation + + align:start position:0% +creative or just doing each operation + + + align:start position:0% +creative or just doing each operation +with no intent other than learning the + + align:start position:0% +with no intent other than learning the + + + align:start position:0% +with no intent other than learning the +operation if you're not feeling creative + + align:start position:0% +operation if you're not feeling creative + + + align:start position:0% +operation if you're not feeling creative +it's up to you so some people made + + align:start position:0% +it's up to you so some people made + + + align:start position:0% +it's up to you so some people made +really cool stuff and some people just + + align:start position:0% +really cool stuff and some people just + + + align:start position:0% +really cool stuff and some people just +have fun and anything is fine thing so + + align:start position:0% +have fun and anything is fine thing so + + + align:start position:0% +have fun and anything is fine thing so +we're going to go through a bunch of + + align:start position:0% +we're going to go through a bunch of + + + align:start position:0% +we're going to go through a bunch of +things so one is drilling holes and + + align:start position:0% +things so one is drilling holes and + + + align:start position:0% +things so one is drilling holes and +sheet metal and you also want to cut pc + + align:start position:0% +sheet metal and you also want to cut pc + + + align:start position:0% +sheet metal and you also want to cut pc +pipe and if you you could cut this on + + align:start position:0% +pipe and if you you could cut this on + + + align:start position:0% +pipe and if you you could cut this on +the bandsaw but it's probably going to + + align:start position:0% +the bandsaw but it's probably going to + + + align:start position:0% +the bandsaw but it's probably going to +be a little and even and this is + + align:start position:0% +be a little and even and this is + + + align:start position:0% +be a little and even and this is +actually faster and really successful so + + align:start position:0% +actually faster and really successful so + + + align:start position:0% +actually faster and really successful so +what you do with this PVC cutter is you + + align:start position:0% +what you do with this PVC cutter is you + + + align:start position:0% +what you do with this PVC cutter is you +just open it all the way up and then + + align:start position:0% +just open it all the way up and then + + + align:start position:0% +just open it all the way up and then +just tonight you really quickly cut a + + align:start position:0% +just tonight you really quickly cut a + + + align:start position:0% +just tonight you really quickly cut a +ring very handy you couldn't use that + + align:start position:0% +ring very handy you couldn't use that + + + align:start position:0% +ring very handy you couldn't use that +tool on metal unfortunately so we have + + align:start position:0% +tool on metal unfortunately so we have + + + align:start position:0% +tool on metal unfortunately so we have +this tool for cutting pipe this is the + + align:start position:0% +this tool for cutting pipe this is the + + + align:start position:0% +this tool for cutting pipe this is the +sharp bit and these are just bearings + + align:start position:0% +sharp bit and these are just bearings + + + align:start position:0% +sharp bit and these are just bearings +that allow the pipe to spin around and + + align:start position:0% +that allow the pipe to spin around and + + + align:start position:0% +that allow the pipe to spin around and +around so what you do is you open it up + + align:start position:0% +around so what you do is you open it up + + + align:start position:0% +around so what you do is you open it up +you load the copper in you tighten it + + align:start position:0% +you load the copper in you tighten it + + + align:start position:0% +you load the copper in you tighten it +and then you spin it around a few times + + align:start position:0% +and then you spin it around a few times + + + align:start position:0% +and then you spin it around a few times +tight Nets band tight and spend the more + + align:start position:0% +tight Nets band tight and spend the more + + + align:start position:0% +tight Nets band tight and spend the more +times you tighten and spin then the + + align:start position:0% +times you tighten and spin then the + + + align:start position:0% +times you tighten and spin then the +cleaner edge you'll get if you really + + align:start position:0% +cleaner edge you'll get if you really + + + align:start position:0% +cleaner edge you'll get if you really +just use a lot of course of course it'll + + align:start position:0% +just use a lot of course of course it'll + + + align:start position:0% +just use a lot of course of course it'll +work but it'll be ugly so this is copper + + align:start position:0% +work but it'll be ugly so this is copper + + + align:start position:0% +work but it'll be ugly so this is copper +which is expensive and we don't have + + align:start position:0% +which is expensive and we don't have + + + align:start position:0% +which is expensive and we don't have +that much so this is the one area where + + align:start position:0% +that much so this is the one area where + + + align:start position:0% +that much so this is the one area where +you need to just cut a little ring don't + + align:start position:0% +you need to just cut a little ring don't + + + align:start position:0% +you need to just cut a little ring don't +cut after yourself we also are going to + + align:start position:0% +cut after yourself we also are going to + + + align:start position:0% +cut after yourself we also are going to +cut rebar so the hacksaw is ready here + + align:start position:0% +cut rebar so the hacksaw is ready here + + + align:start position:0% +cut rebar so the hacksaw is ready here +for cutting leave our well you could + + align:start position:0% +for cutting leave our well you could + + + align:start position:0% +for cutting leave our well you could +just hold the rebar in one hand and use + + align:start position:0% +just hold the rebar in one hand and use + + + align:start position:0% +just hold the rebar in one hand and use +the hex on the other it's going to be + + align:start position:0% +the hex on the other it's going to be + + + align:start position:0% +the hex on the other it's going to be +really miserable and your possible to do + + align:start position:0% +really miserable and your possible to do + + + align:start position:0% +really miserable and your possible to do +successfully so we have advice so you + + align:start position:0% +successfully so we have advice so you + + + align:start position:0% +successfully so we have advice so you +can load the rebar in and then cut so + + align:start position:0% +can load the rebar in and then cut so + + + align:start position:0% +can load the rebar in and then cut so +you too long maybe there's a bigger + + align:start position:0% +you too long maybe there's a bigger + + + align:start position:0% +you too long maybe there's a bigger +fight + + align:start position:0% +fight + + + align:start position:0% +fight +Oh \ No newline at end of file diff --git a/zdotUAxiPGM.txt b/zdotUAxiPGM.txt new file mode 100644 index 0000000000000000000000000000000000000000..78f4694e6a3264afb62def3d000af9ebe5bfcbd6 --- /dev/null +++ b/zdotUAxiPGM.txt @@ -0,0 +1,9259 @@ +align:start position:0% + +a three-part lecture today still + + align:start position:0% +a three-part lecture today still + + + align:start position:0% +a three-part lecture today still +continuing on the theme of reinforcement + + align:start position:0% +continuing on the theme of reinforcement + + + align:start position:0% +continuing on the theme of reinforcement +learning part one I'm going to be + + align:start position:0% +learning part one I'm going to be + + + align:start position:0% +learning part one I'm going to be +speaking and I will be following up on + + align:start position:0% +speaking and I will be following up on + + + align:start position:0% +speaking and I will be following up on +last week's discussion about causal + + align:start position:0% +last week's discussion about causal + + + align:start position:0% +last week's discussion about causal +inference and Tuesday's discussion on + + align:start position:0% +inference and Tuesday's discussion on + + + align:start position:0% +inference and Tuesday's discussion on +reinforcement learning and I'll be going + + align:start position:0% +reinforcement learning and I'll be going + + + align:start position:0% +reinforcement learning and I'll be going +into sort of one one more subtlety that + + align:start position:0% +into sort of one one more subtlety that + + + align:start position:0% +into sort of one one more subtlety that +that arises there and where we can + + align:start position:0% +that arises there and where we can + + + align:start position:0% +that arises there and where we can +develop some nice mathematical methods + + align:start position:0% +develop some nice mathematical methods + + + align:start position:0% +develop some nice mathematical methods +to help with and then I'm going to turn + + align:start position:0% +to help with and then I'm going to turn + + + align:start position:0% +to help with and then I'm going to turn +over the show to to Barbara who will + + align:start position:0% +over the show to to Barbara who will + + + align:start position:0% +over the show to to Barbara who will +formally introduce when the time comes + + align:start position:0% +formally introduce when the time comes + + + align:start position:0% +formally introduce when the time comes +and she's going to both talk about some + + align:start position:0% +and she's going to both talk about some + + + align:start position:0% +and she's going to both talk about some +of her work on developing on evaluating + + align:start position:0% +of her work on developing on evaluating + + + align:start position:0% +of her work on developing on evaluating +dynamics treatment regimes and + + align:start position:0% +dynamics treatment regimes and + + + align:start position:0% +dynamics treatment regimes and +eventually lead a discussion on the + + align:start position:0% +eventually lead a discussion on the + + + align:start position:0% +eventually lead a discussion on the +sepsis paper which was required reading + + align:start position:0% +sepsis paper which was required reading + + + align:start position:0% +sepsis paper which was required reading +from today's class so those are the + + align:start position:0% +from today's class so those are the + + + align:start position:0% +from today's class so those are the +three parts today's today's lecture so I + + align:start position:0% +three parts today's today's lecture so I + + + align:start position:0% +three parts today's today's lecture so I +want you to return back put your back in + + align:start position:0% +want you to return back put your back in + + + align:start position:0% +want you to return back put your back in +your self back in the mindset of + + align:start position:0% +your self back in the mindset of + + + align:start position:0% +your self back in the mindset of +Tuesday's lecture where we talk about + + align:start position:0% +Tuesday's lecture where we talk about + + + align:start position:0% +Tuesday's lecture where we talk about +reinforcement learning I remember that + + align:start position:0% +reinforcement learning I remember that + + + align:start position:0% +reinforcement learning I remember that +the goal of reinforcement learning was + + align:start position:0% +the goal of reinforcement learning was + + + align:start position:0% +the goal of reinforcement learning was +to optimize some reward specifically our + + align:start position:0% +to optimize some reward specifically our + + + align:start position:0% +to optimize some reward specifically our +goal was to find some policy which I'm + + align:start position:0% +goal was to find some policy which I'm + + + align:start position:0% +goal was to find some policy which I'm +going to go to spy star which is the Arg + + align:start position:0% +going to go to spy star which is the Arg + + + align:start position:0% +going to go to spy star which is the Arg +max over all possible policies PI of V + + align:start position:0% +max over all possible policies PI of V + + + align:start position:0% +max over all possible policies PI of V +of Pi where just remind you V if pi is + + align:start position:0% +of Pi where just remind you V if pi is + + + align:start position:0% +of Pi where just remind you V if pi is +the value of the policy PI formally it's + + align:start position:0% +the value of the policy PI formally it's + + + align:start position:0% +the value of the policy PI formally it's +defined as the expectation of the sum of + + align:start position:0% +defined as the expectation of the sum of + + + align:start position:0% +defined as the expectation of the sum of +the rewards across time okay so the + + align:start position:0% +the rewards across time okay so the + + + align:start position:0% +the rewards across time okay so the +reason why I'm calling this an + + align:start position:0% +reason why I'm calling this an + + + align:start position:0% +reason why I'm calling this an +expectation is like the PI is because + + align:start position:0% +expectation is like the PI is because + + + align:start position:0% +expectation is like the PI is because +there's stochasticity both in the + + align:start position:0% +there's stochasticity both in the + + + align:start position:0% +there's stochasticity both in the +environment and possibly pi e is going + + align:start position:0% +environment and possibly pi e is going + + + align:start position:0% +environment and possibly pi e is going +to be a stochastic policy and this is + + align:start position:0% +to be a stochastic policy and this is + + + align:start position:0% +to be a stochastic policy and this is +summing over the time steps because this + + align:start position:0% +summing over the time steps because this + + + align:start position:0% +summing over the time steps because this +is a this is not just a single time step + + align:start position:0% +is a this is not just a single time step + + + align:start position:0% +is a this is not just a single time step +problem but we're going to be + + align:start position:0% +problem but we're going to be + + + align:start position:0% +problem but we're going to be +considering interventions across time of + + align:start position:0% +considering interventions across time of + + + align:start position:0% +considering interventions across time of +the reward at each point in time and the + + align:start position:0% +the reward at each point in time and the + + + align:start position:0% +the reward at each point in time and the +reward function could either be at each + + align:start position:0% +reward function could either be at each + + + align:start position:0% +reward function could either be at each +point in time or you might imagine that + + align:start position:0% +point in time or you might imagine that + + + align:start position:0% +point in time or you might imagine that +this is zero for all time steps except + + align:start position:0% +this is zero for all time steps except + + + align:start position:0% +this is zero for all time steps except +the last time step so the first question + + align:start position:0% +the last time step so the first question + + + align:start position:0% +the last time step so the first question +I want to think about is well what are + + align:start position:0% +I want to think about is well what are + + + align:start position:0% +I want to think about is well what are +the implications of this as a learning + + align:start position:0% +the implications of this as a learning + + + align:start position:0% +the implications of this as a learning +paradigm if we look what's going on over + + align:start position:0% +paradigm if we look what's going on over + + + align:start position:0% +paradigm if we look what's going on over +here hidden in my story is also an + + align:start position:0% +here hidden in my story is also an + + + align:start position:0% +here hidden in my story is also an +expectation over acts the in the patient + + align:start position:0% +expectation over acts the in the patient + + + align:start position:0% +expectation over acts the in the patient +for example or the initial state and so + + align:start position:0% +for example or the initial state and so + + + align:start position:0% +for example or the initial state and so +this intuitively is saying let's try to + + align:start position:0% +this intuitively is saying let's try to + + + align:start position:0% +this intuitively is saying let's try to +find a policy that has high expected + + align:start position:0% +find a policy that has high expected + + + align:start position:0% +find a policy that has high expected +reward average nessing's over all + + align:start position:0% +reward average nessing's over all + + + align:start position:0% +reward average nessing's over all +patients and I just want to you think + + align:start position:0% +patients and I just want to you think + + + align:start position:0% +patients and I just want to you think +about whether that isn't indeed the + + align:start position:0% +about whether that isn't indeed the + + + align:start position:0% +about whether that isn't indeed the +right goal okay can anyone think about a + + align:start position:0% +right goal okay can anyone think about a + + + align:start position:0% +right goal okay can anyone think about a +setting where that might not be + + align:start position:0% +setting where that might not be + + + align:start position:0% +setting where that might not be +desirable yep + + align:start position:0% +desirable yep + + + align:start position:0% +desirable yep +what if the reward is the patient living + + align:start position:0% +what if the reward is the patient living + + + align:start position:0% +what if the reward is the patient living +or dying you don't want it doing have + + align:start position:0% +or dying you don't want it doing have + + + align:start position:0% +or dying you don't want it doing have +high ratings like saving to patients and + + align:start position:0% +high ratings like saving to patients and + + + align:start position:0% +high ratings like saving to patients and +see what they expected since panics all + + align:start position:0% +see what they expected since panics all + + + align:start position:0% +see what they expected since panics all +right so what happens this word is + + align:start position:0% +right so what happens this word is + + + align:start position:0% +right so what happens this word is +something mission critical like patient + + align:start position:0% +something mission critical like patient + + + align:start position:0% +something mission critical like patient +patient dying you really want to try to + + align:start position:0% +patient dying you really want to try to + + + align:start position:0% +patient dying you really want to try to +avoid that from happening as much as + + align:start position:0% +avoid that from happening as much as + + + align:start position:0% +avoid that from happening as much as +possible of course there are other + + align:start position:0% +possible of course there are other + + + align:start position:0% +possible of course there are other +criteria that we might be interested in + + align:start position:0% +criteria that we might be interested in + + + align:start position:0% +criteria that we might be interested in +as well + + align:start position:0% +as well + + + align:start position:0% +as well +and both in Fredericks lecture on + + align:start position:0% +and both in Fredericks lecture on + + + align:start position:0% +and both in Fredericks lecture on +Tuesday and in the readings we talked + + align:start position:0% +Tuesday and in the readings we talked + + + align:start position:0% +Tuesday and in the readings we talked +about how there might be other aspects + + align:start position:0% +about how there might be other aspects + + + align:start position:0% +about how there might be other aspects +about making sure that a patient is just + + align:start position:0% +about making sure that a patient is just + + + align:start position:0% +about making sure that a patient is just +not just alive but also healthy which + + align:start position:0% +not just alive but also healthy which + + + align:start position:0% +not just alive but also healthy which +might play into reward function so there + + align:start position:0% +might play into reward function so there + + + align:start position:0% +might play into reward function so there +might be rewards to rate those and if + + align:start position:0% +might be rewards to rate those and if + + + align:start position:0% +might be rewards to rate those and if +you were to just for example put a + + align:start position:0% +you were to just for example put a + + + align:start position:0% +you were to just for example put a +positive or negative infinity for + + align:start position:0% +positive or negative infinity for + + + align:start position:0% +positive or negative infinity for +patient dying that's a non-starter right + + align:start position:0% +patient dying that's a non-starter right + + + align:start position:0% +patient dying that's a non-starter right +because if you did that unfortunately in + + align:start position:0% +because if you did that unfortunately in + + + align:start position:0% +because if you did that unfortunately in +this situation in this world we're not + + align:start position:0% +this situation in this world we're not + + + align:start position:0% +this situation in this world we're not +always going to be able to keep patients + + align:start position:0% +always going to be able to keep patients + + + align:start position:0% +always going to be able to keep patients +alive and so you're going to get into an + + align:start position:0% +alive and so you're going to get into an + + + align:start position:0% +alive and so you're going to get into an +infeasible optimization problem so minus + + align:start position:0% +infeasible optimization problem so minus + + + align:start position:0% +infeasible optimization problem so minus +infinity is not an option we're going to + + align:start position:0% +infinity is not an option we're going to + + + align:start position:0% +infinity is not an option we're going to +have to put some number to it in this + + align:start position:0% +have to put some number to it in this + + + align:start position:0% +have to put some number to it in this +type of approach but then you're going + + align:start position:0% +type of approach but then you're going + + + align:start position:0% +type of approach but then you're going +to start trading off between patients + + align:start position:0% +to start trading off between patients + + + align:start position:0% +to start trading off between patients +you know in some cases you might you + + align:start position:0% +you know in some cases you might you + + + align:start position:0% +you know in some cases you might you +might have a very high reward for you + + align:start position:0% +might have a very high reward for you + + + align:start position:0% +might have a very high reward for you +might you there are two different + + align:start position:0% +might you there are two different + + + align:start position:0% +might you there are two different +equations that you can might imagine one + + align:start position:0% +equations that you can might imagine one + + + align:start position:0% +equations that you can might imagine one +solution where the reward is somewhat + + align:start position:0% +solution where the reward is somewhat + + + align:start position:0% +solution where the reward is somewhat +balanced across patients and another + + align:start position:0% +balanced across patients and another + + + align:start position:0% +balanced across patients and another +situation where you have really small + + align:start position:0% +situation where you have really small + + + align:start position:0% +situation where you have really small +values of + + align:start position:0% +values of + + + align:start position:0% +values of +for some patience and a few patients + + align:start position:0% +for some patience and a few patients + + + align:start position:0% +for some patience and a few patients +with very large values and rewards and + + align:start position:0% +with very large values and rewards and + + + align:start position:0% +with very large values and rewards and +both would give you the same average + + align:start position:0% +both would give you the same average + + + align:start position:0% +both would give you the same average +obviously but not both but both are not + + align:start position:0% +obviously but not both but both are not + + + align:start position:0% +obviously but not both but both are not +necessarily equally useful right we + + align:start position:0% +necessarily equally useful right we + + + align:start position:0% +necessarily equally useful right we +might want to say that we prefer to + + align:start position:0% +might want to say that we prefer to + + + align:start position:0% +might want to say that we prefer to +avoid that worst case situation so one + + align:start position:0% +avoid that worst case situation so one + + + align:start position:0% +avoid that worst case situation so one +could imagine other ways of formulating + + align:start position:0% +could imagine other ways of formulating + + + align:start position:0% +could imagine other ways of formulating +this optimization problem like maybe you + + align:start position:0% +this optimization problem like maybe you + + + align:start position:0% +this optimization problem like maybe you +want to maybe you want to control the + + align:start position:0% +want to maybe you want to control the + + + align:start position:0% +want to maybe you want to control the +worst case reward instead of the average + + align:start position:0% +worst case reward instead of the average + + + align:start position:0% +worst case reward instead of the average +case reward or maybe you want to say + + align:start position:0% +case reward or maybe you want to say + + + align:start position:0% +case reward or maybe you want to say +something about different quartiles I + + align:start position:0% +something about different quartiles I + + + align:start position:0% +something about different quartiles I +just wanted to point that out because + + align:start position:0% +just wanted to point that out because + + + align:start position:0% +just wanted to point that out because +really that's the starting place for a + + align:start position:0% +really that's the starting place for a + + + align:start position:0% +really that's the starting place for a +lot of the work that we're doing here so + + align:start position:0% +lot of the work that we're doing here so + + + align:start position:0% +lot of the work that we're doing here so +now that wants to think they're okay + + align:start position:0% +now that wants to think they're okay + + + align:start position:0% +now that wants to think they're okay +returning back to this goal we've done + + align:start position:0% +returning back to this goal we've done + + + align:start position:0% +returning back to this goal we've done +our policy iteration and/or we've done + + align:start position:0% +our policy iteration and/or we've done + + + align:start position:0% +our policy iteration and/or we've done +our cue learning that is and we get a + + align:start position:0% +our cue learning that is and we get a + + + align:start position:0% +our cue learning that is and we get a +policy out and when might now want to + + align:start position:0% +policy out and when might now want to + + + align:start position:0% +policy out and when might now want to +know well what is the value of that + + align:start position:0% +know well what is the value of that + + + align:start position:0% +know well what is the value of that +policy right so what is our estimate of + + align:start position:0% +policy right so what is our estimate of + + + align:start position:0% +policy right so what is our estimate of +that quantity well to get that one could + + align:start position:0% +that quantity well to get that one could + + + align:start position:0% +that quantity well to get that one could +just try to read it off from the results + + align:start position:0% +just try to read it off from the results + + + align:start position:0% +just try to read it off from the results +of Q learning + + align:start position:0% +of Q learning + + + align:start position:0% +of Q learning +by just computing that V PI well V PI + + align:start position:0% +by just computing that V PI well V PI + + + align:start position:0% +by just computing that V PI well V PI +hat the estimate is just equal to now a + + align:start position:0% +hat the estimate is just equal to now a + + + align:start position:0% +hat the estimate is just equal to now a +maximum over actions a of your Q + + align:start position:0% +maximum over actions a of your Q + + + align:start position:0% +maximum over actions a of your Q +function evaluated at whatever your + + align:start position:0% +function evaluated at whatever your + + + align:start position:0% +function evaluated at whatever your +initial state is and your and the + + align:start position:0% +initial state is and your and the + + + align:start position:0% +initial state is and your and the +optimal choice of action a all right so + + align:start position:0% +optimal choice of action a all right so + + + align:start position:0% +optimal choice of action a all right so +this is all I'm saying here is that the + + align:start position:0% +this is all I'm saying here is that the + + + align:start position:0% +this is all I'm saying here is that the +last step of that will be that might be + + align:start position:0% +last step of that will be that might be + + + align:start position:0% +last step of that will be that might be +to ask well what is the expected reward + + align:start position:0% +to ask well what is the expected reward + + + align:start position:0% +to ask well what is the expected reward +of this policy and if remember the Q + + align:start position:0% +of this policy and if remember the Q + + + align:start position:0% +of this policy and if remember the Q +learning algorithm is essence that + + align:start position:0% +learning algorithm is essence that + + + align:start position:0% +learning algorithm is essence that +dynamic programming algorithm working + + align:start position:0% +dynamic programming algorithm working + + + align:start position:0% +dynamic programming algorithm working +its way from the you know sort of large + + align:start position:0% +its way from the you know sort of large + + + align:start position:0% +its way from the you know sort of large +values of time up to the up to the + + align:start position:0% +values of time up to the up to the + + + align:start position:0% +values of time up to the up to the +present and it is indeed actually + + align:start position:0% +present and it is indeed actually + + + align:start position:0% +present and it is indeed actually +computing this expected value that + + align:start position:0% +computing this expected value that + + + align:start position:0% +computing this expected value that +you're interested in so you could just + + align:start position:0% +you're interested in so you could just + + + align:start position:0% +you're interested in so you could just +read it off from the Q values at the + + align:start position:0% +read it off from the Q values at the + + + align:start position:0% +read it off from the Q values at the +very end but I want to point out that + + align:start position:0% +very end but I want to point out that + + + align:start position:0% +very end but I want to point out that +here there's an implicit policy built-in + + align:start position:0% +here there's an implicit policy built-in + + + align:start position:0% +here there's an implicit policy built-in +right so I'm gonna compare this in just + + align:start position:0% +right so I'm gonna compare this in just + + + align:start position:0% +right so I'm gonna compare this in just +a second to what happens under the + + align:start position:0% +a second to what happens under the + + + align:start position:0% +a second to what happens under the +causal inference scenarios or just a + + align:start position:0% +causal inference scenarios or just a + + + align:start position:0% +causal inference scenarios or just a +single time step and potential outcomes + + align:start position:0% +single time step and potential outcomes + + + align:start position:0% +single time step and potential outcomes +framework that were used to notice that + + align:start position:0% +framework that were used to notice that + + + align:start position:0% +framework that were used to notice that +the value of this policy it's the reason + + align:start position:0% +the value of this policy it's the reason + + + align:start position:0% +the value of this policy it's the reason +why it's a function of of Pi is because + + align:start position:0% +why it's a function of of Pi is because + + + align:start position:0% +why it's a function of of Pi is because +the values of + + align:start position:0% +the values of + + + align:start position:0% +the values of +is a function of every subsequent action + + align:start position:0% +is a function of every subsequent action + + + align:start position:0% +is a function of every subsequent action +that you're taking as well and so now + + align:start position:0% +that you're taking as well and so now + + + align:start position:0% +that you're taking as well and so now +let's just compare that for a second to + + align:start position:0% +let's just compare that for a second to + + + align:start position:0% +let's just compare that for a second to +what happens within the potential + + align:start position:0% +what happens within the potential + + + align:start position:0% +what happens within the potential +outcomes framework so there are starting + + align:start position:0% +outcomes framework so there are starting + + + align:start position:0% +outcomes framework so there are starting +place so now I'm going to I'm going to + + align:start position:0% +place so now I'm going to I'm going to + + + align:start position:0% +place so now I'm going to I'm going to +turn our attention for one just one + + align:start position:0% +turn our attention for one just one + + + align:start position:0% +turn our attention for one just one +moment from reinforcement learning now + + align:start position:0% +moment from reinforcement learning now + + + align:start position:0% +moment from reinforcement learning now +back to just causal inference and + + align:start position:0% +back to just causal inference and + + + align:start position:0% +back to just causal inference and +reinforcement learning we talked about + + align:start position:0% +reinforcement learning we talked about + + + align:start position:0% +reinforcement learning we talked about +policies how do we find policies to do + + align:start position:0% +policies how do we find policies to do + + + align:start position:0% +policies how do we find policies to do +well in terms of some expected reward of + + align:start position:0% +well in terms of some expected reward of + + + align:start position:0% +well in terms of some expected reward of +this policy but yet when we were talking + + align:start position:0% +this policy but yet when we were talking + + + align:start position:0% +this policy but yet when we were talking +about causal inference we only used + + align:start position:0% +about causal inference we only used + + + align:start position:0% +about causal inference we only used +words like average treatment effect or + + align:start position:0% +words like average treatment effect or + + + align:start position:0% +words like average treatment effect or +conditional average treatment effect + + align:start position:0% +conditional average treatment effect + + + align:start position:0% +conditional average treatment effect +where for example to estimate the + + align:start position:0% +where for example to estimate the + + + align:start position:0% +where for example to estimate the +conditional average treatment effect + + align:start position:0% +conditional average treatment effect + + + align:start position:0% +conditional average treatment effect +what we said is we're going to first + + align:start position:0% +what we said is we're going to first + + + align:start position:0% +what we said is we're going to first +learn if we use if you we use a + + align:start position:0% +learn if we use if you we use a + + + align:start position:0% +learn if we use if you we use a +covariate judgment approach we learn + + align:start position:0% +covariate judgment approach we learn + + + align:start position:0% +covariate judgment approach we learn +some function f of X comma T which is + + align:start position:0% +some function f of X comma T which is + + + align:start position:0% +some function f of X comma T which is +intended to be an approximation of the + + align:start position:0% +intended to be an approximation of the + + + align:start position:0% +intended to be an approximation of the +expected value of your outcome Y given X + + align:start position:0% +expected value of your outcome Y given X + + + align:start position:0% +expected value of your outcome Y given X +comma comma o say I'll say Y of T there + + align:start position:0% +comma comma o say I'll say Y of T there + + + align:start position:0% +comma comma o say I'll say Y of T there +so that notation so the goal of Kaveri + + align:start position:0% +so that notation so the goal of Kaveri + + + align:start position:0% +so that notation so the goal of Kaveri +adjustment was to estimate this quantity + + align:start position:0% +adjustment was to estimate this quantity + + + align:start position:0% +adjustment was to estimate this quantity +and we could use that then to try to + + align:start position:0% +and we could use that then to try to + + + align:start position:0% +and we could use that then to try to +construct a policy for example you could + + align:start position:0% +construct a policy for example you could + + + align:start position:0% +construct a policy for example you could +continue could think about the policy PI + + align:start position:0% +continue could think about the policy PI + + + align:start position:0% +continue could think about the policy PI +of X which simply looks to see is it + + align:start position:0% +of X which simply looks to see is it + + + align:start position:0% +of X which simply looks to see is it +will say it's 1 if Kate or your estimate + + align:start position:0% +will say it's 1 if Kate or your estimate + + + align:start position:0% +will say it's 1 if Kate or your estimate +of Kate for X is positive and 0 + + align:start position:0% +of Kate for X is positive and 0 + + + align:start position:0% +of Kate for X is positive and 0 +otherwise just remind you the way that + + align:start position:0% +otherwise just remind you the way that + + + align:start position:0% +otherwise just remind you the way that +we got the estimate of Kate for an + + align:start position:0% +we got the estimate of Kate for an + + + align:start position:0% +we got the estimate of Kate for an +individual acts was just by looking at f + + align:start position:0% +individual acts was just by looking at f + + + align:start position:0% +individual acts was just by looking at f +of + + align:start position:0% +of + + + align:start position:0% +of +X comma 1 minus f of X comma 0 ok so if + + align:start position:0% +X comma 1 minus f of X comma 0 ok so if + + + align:start position:0% +X comma 1 minus f of X comma 0 ok so if +we have a policy so now we're gonna + + align:start position:0% +we have a policy so now we're gonna + + + align:start position:0% +we have a policy so now we're gonna +start thinking about policies in the + + align:start position:0% +start thinking about policies in the + + + align:start position:0% +start thinking about policies in the +context of causal inference just like we + + align:start position:0% +context of causal inference just like we + + + align:start position:0% +context of causal inference just like we +were doing in reinforcement learning and + + align:start position:0% +were doing in reinforcement learning and + + + align:start position:0% +were doing in reinforcement learning and +I want us to think through what would + + align:start position:0% +I want us to think through what would + + + align:start position:0% +I want us to think through what would +the analogous value of the policy be + + align:start position:0% +the analogous value of the policy be + + + align:start position:0% +the analogous value of the policy be +right + + align:start position:0% +right + + + align:start position:0% +right +how good is is that policy it could be + + align:start position:0% +how good is is that policy it could be + + + align:start position:0% +how good is is that policy it could be +another policy but right now I'm + + align:start position:0% +another policy but right now I'm + + + align:start position:0% +another policy but right now I'm +assuming I'm just going to focus on this + + align:start position:0% +assuming I'm just going to focus on this + + + align:start position:0% +assuming I'm just going to focus on this +policy that show up here well one + + align:start position:0% +policy that show up here well one + + + align:start position:0% +policy that show up here well one +approach to try to evaluate how good + + align:start position:0% +approach to try to evaluate how good + + + align:start position:0% +approach to try to evaluate how good +that policy would is is exactly + + align:start position:0% +that policy would is is exactly + + + align:start position:0% +that policy would is is exactly +analogous to what we did in + + align:start position:0% +analogous to what we did in + + + align:start position:0% +analogous to what we did in +reinforcement learning in essence what + + align:start position:0% +reinforcement learning in essence what + + + align:start position:0% +reinforcement learning in essence what +we're gonna say is we evaluate the quote + + align:start position:0% +we're gonna say is we evaluate the quote + + + align:start position:0% +we're gonna say is we evaluate the quote +of the policy by summing over your + + align:start position:0% +of the policy by summing over your + + + align:start position:0% +of the policy by summing over your +empirical data of PI of X I so this is + + align:start position:0% +empirical data of PI of X I so this is + + + align:start position:0% +empirical data of PI of X I so this is +going to be 1 if the policy says to give + + align:start position:0% +going to be 1 if the policy says to give + + + align:start position:0% +going to be 1 if the policy says to give +treatment 1 to individual X I that in + + align:start position:0% +treatment 1 to individual X I that in + + + align:start position:0% +treatment 1 to individual X I that in +that case we say that the value is f of + + align:start position:0% +that case we say that the value is f of + + + align:start position:0% +that case we say that the value is f of +X comma 1 or if you gave the second if + + align:start position:0% +X comma 1 or if you gave the second if + + + align:start position:0% +X comma 1 or if you gave the second if +the policy would would give treatment 0 + + align:start position:0% +the policy would would give treatment 0 + + + align:start position:0% +the policy would would give treatment 0 +the value of the policy on that + + align:start position:0% +the value of the policy on that + + + align:start position:0% +the value of the policy on that +individual is 1 minus PI of X times f of + + align:start position:0% +individual is 1 minus PI of X times f of + + + align:start position:0% +individual is 1 minus PI of X times f of +X comma 0 so I'm going to call this an X + + align:start position:0% +X comma 0 so I'm going to call this an X + + + align:start position:0% +X comma 0 so I'm going to call this an X +sort of an empirical estimate of the + + align:start position:0% +sort of an empirical estimate of the + + + align:start position:0% +sort of an empirical estimate of the +what you should think about as the + + align:start position:0% +what you should think about as the + + + align:start position:0% +what you should think about as the +reward for a policy PI + + align:start position:0% + + + + align:start position:0% + +and an a yes to the estimate of a V of + + align:start position:0% +and an a yes to the estimate of a V of + + + align:start position:0% +and an a yes to the estimate of a V of +Pi that you would get from a + + align:start position:0% +Pi that you would get from a + + + align:start position:0% +Pi that you would get from a +reinforcement learning context but now + + align:start position:0% +reinforcement learning context but now + + + align:start position:0% +reinforcement learning context but now +we're talking about policy that + + align:start position:0% +we're talking about policy that + + + align:start position:0% +we're talking about policy that +explicitly so let's try to dig down a + + align:start position:0% +explicitly so let's try to dig down a + + + align:start position:0% +explicitly so let's try to dig down a +little bit deeper and think about what + + align:start position:0% +little bit deeper and think about what + + + align:start position:0% +little bit deeper and think about what +this is actually saying imagine the + + align:start position:0% +this is actually saying imagine the + + + align:start position:0% +this is actually saying imagine the +story where you just have a single + + align:start position:0% +story where you just have a single + + + align:start position:0% +story where you just have a single +covariant X we'll think about access + + align:start position:0% +covariant X we'll think about access + + + align:start position:0% +covariant X we'll think about access +being let's say the patient's age and + + align:start position:0% + + + + align:start position:0% + +fortunately there's just one color here + + align:start position:0% +fortunately there's just one color here + + + align:start position:0% +fortunately there's just one color here +but I'll do my best with that and + + align:start position:0% +but I'll do my best with that and + + + align:start position:0% +but I'll do my best with that and +imagine that the potential outcome Y is + + align:start position:0% +imagine that the potential outcome Y is + + + align:start position:0% +imagine that the potential outcome Y is +zero as a function of the patient's age + + align:start position:0% +zero as a function of the patient's age + + + align:start position:0% +zero as a function of the patient's age +axe looks like this now imagine that the + + align:start position:0% +axe looks like this now imagine that the + + + align:start position:0% +axe looks like this now imagine that the +other potential outcome y1 look like + + align:start position:0% +other potential outcome y1 look like + + + align:start position:0% +other potential outcome y1 look like +that all right so I'll call this the Y + + align:start position:0% +that all right so I'll call this the Y + + + align:start position:0% +that all right so I'll call this the Y +one potential outcome suppose now that + + align:start position:0% +one potential outcome suppose now that + + + align:start position:0% +one potential outcome suppose now that +the policy that we're defining is this + + align:start position:0% +the policy that we're defining is this + + + align:start position:0% +the policy that we're defining is this +so we're going to give treatment 1 if + + align:start position:0% +so we're going to give treatment 1 if + + + align:start position:0% +so we're going to give treatment 1 if +the conditional average treatment effect + + align:start position:0% +the conditional average treatment effect + + + align:start position:0% +the conditional average treatment effect +is positive and 0 otherwise I want + + align:start position:0% +is positive and 0 otherwise I want + + + align:start position:0% +is positive and 0 otherwise I want +everyone to draw what the value of that + + align:start position:0% +everyone to draw what the value of that + + + align:start position:0% +everyone to draw what the value of that +policy is on a piece of paper it's going + + align:start position:0% +policy is on a piece of paper it's going + + + align:start position:0% +policy is on a piece of paper it's going +to be I'm sorry I want everyone to write + + align:start position:0% +to be I'm sorry I want everyone to write + + + align:start position:0% +to be I'm sorry I want everyone to write +on a piece of paper what the value of + + align:start position:0% +on a piece of paper what the value of + + + align:start position:0% +on a piece of paper what the value of +the policy would be for each individual + + align:start position:0% +the policy would be for each individual + + + align:start position:0% +the policy would be for each individual +so it's going to be a function of X and + + align:start position:0% +so it's going to be a function of X and + + + align:start position:0% +so it's going to be a function of X and +now I want it to be I'm looking for y of + + align:start position:0% +now I want it to be I'm looking for y of + + + align:start position:0% +now I want it to be I'm looking for y of +PI of X ok + + align:start position:0% +PI of X ok + + + align:start position:0% +PI of X ok +so I'm looking for you to draw that plot + + align:start position:0% +so I'm looking for you to draw that plot + + + align:start position:0% +so I'm looking for you to draw that plot +and feel free to talk to your neighbor + + align:start position:0% +and feel free to talk to your neighbor + + + align:start position:0% +and feel free to talk to your neighbor +in fact I encourage you to talk to your + + align:start position:0% +in fact I encourage you to talk to your + + + align:start position:0% +in fact I encourage you to talk to your +neighbor + + align:start position:0% + + + + align:start position:0% + +just to try to connect this a little bit + + align:start position:0% +just to try to connect this a little bit + + + align:start position:0% +just to try to connect this a little bit +better to what I have up here I'm gonna + + align:start position:0% +better to what I have up here I'm gonna + + + align:start position:0% +better to what I have up here I'm gonna +assume that F this is f of X 1 and this + + align:start position:0% +assume that F this is f of X 1 and this + + + align:start position:0% +assume that F this is f of X 1 and this +is f of X 0 all right any any guesses + + align:start position:0% +is f of X 0 all right any any guesses + + + align:start position:0% +is f of X 0 all right any any guesses +what does this pot look like someone who + + align:start position:0% +what does this pot look like someone who + + + align:start position:0% +what does this pot look like someone who +hasn't spoken in the last one week and a + + align:start position:0% +hasn't spoken in the last one week and a + + + align:start position:0% +hasn't spoken in the last one week and a +half if possible so something like this + + align:start position:0% +half if possible so something like this + + + align:start position:0% +half if possible so something like this +until the intersection point and then + + align:start position:0% +until the intersection point and then + + + align:start position:0% +until the intersection point and then +like that outdoors yeah this exact what + + align:start position:0% +like that outdoors yeah this exact what + + + align:start position:0% +like that outdoors yeah this exact what +I'm going for and let's try to think + + align:start position:0% +I'm going for and let's try to think + + + align:start position:0% +I'm going for and let's try to think +through why is that the value of the + + align:start position:0% +through why is that the value of the + + + align:start position:0% +through why is that the value of the +policy well here the Kate which is + + align:start position:0% +policy well here the Kate which is + + + align:start position:0% +policy well here the Kate which is +looking at the difference between these + + align:start position:0% +looking at the difference between these + + + align:start position:0% +looking at the difference between these +two lines is negative right so for every + + align:start position:0% +two lines is negative right so for every + + + align:start position:0% +two lines is negative right so for every +X up to this crossing point the policy + + align:start position:0% +X up to this crossing point the policy + + + align:start position:0% +X up to this crossing point the policy +that we've defined over there is going + + align:start position:0% +that we've defined over there is going + + + align:start position:0% +that we've defined over there is going +to perform action action do to do wait + + align:start position:0% +to perform action action do to do wait + + + align:start position:0% +to perform action action do to do wait +am i drawing this correctly + + align:start position:0% +am i drawing this correctly + + + align:start position:0% +am i drawing this correctly +maybe it's actually opposite right you + + align:start position:0% +maybe it's actually opposite right you + + + align:start position:0% +maybe it's actually opposite right you +should be doing action one okay so here + + align:start position:0% +should be doing action one okay so here + + + align:start position:0% +should be doing action one okay so here +okay so here the Kate is negative and so + + align:start position:0% +okay so here the Kate is negative and so + + + align:start position:0% +okay so here the Kate is negative and so +by my definition the action perform is + + align:start position:0% +by my definition the action perform is + + + align:start position:0% +by my definition the action perform is +action zero and so the the value of the + + align:start position:0% +action zero and so the the value of the + + + align:start position:0% +action zero and so the the value of the +policy is actually this one right wait + + align:start position:0% +policy is actually this one right wait + + + align:start position:0% +policy is actually this one right wait +oh wait oh good you Lou knows what wanna + + align:start position:0% +oh wait oh good you Lou knows what wanna + + + align:start position:0% +oh wait oh good you Lou knows what wanna +get you cuz this is the graph I have in + + align:start position:0% +get you cuz this is the graph I have in + + + align:start position:0% +get you cuz this is the graph I have in +my notes oh good okay + + align:start position:0% +my notes oh good okay + + + align:start position:0% +my notes oh good okay +I was getting I was getting worried okay + + align:start position:0% +I was getting I was getting worried okay + + + align:start position:0% +I was getting I was getting worried okay +so to this action right all the way up + + align:start position:0% +so to this action right all the way up + + + align:start position:0% +so to this action right all the way up +until you get over here + + align:start position:0% +until you get over here + + + align:start position:0% +until you get over here +and then over here now the Kate suddenly + + align:start position:0% +and then over here now the Kate suddenly + + + align:start position:0% +and then over here now the Kate suddenly +becomes positive and so the action + + align:start position:0% +becomes positive and so the action + + + align:start position:0% +becomes positive and so the action +chosen is is one and so and so the value + + align:start position:0% +chosen is is one and so and so the value + + + align:start position:0% +chosen is is one and so and so the value +of that policy is y one okay and so one + + align:start position:0% +of that policy is y one okay and so one + + + align:start position:0% +of that policy is y one okay and so one +could write this a little bit + + align:start position:0% +could write this a little bit + + + align:start position:0% +could write this a little bit +differently for and in the case of just + + align:start position:0% +differently for and in the case of just + + + align:start position:0% +differently for and in the case of just +in the case of just two policies and now + + align:start position:0% +in the case of just two policies and now + + + align:start position:0% +in the case of just two policies and now +I'm going to write this in a way that + + align:start position:0% +I'm going to write this in a way that + + + align:start position:0% +I'm going to write this in a way that +some that it's really clear in the case + + align:start position:0% +some that it's really clear in the case + + + align:start position:0% +some that it's really clear in the case +of just just two actions one could write + + align:start position:0% +of just just two actions one could write + + + align:start position:0% +of just just two actions one could write +this equivalently as an average over the + + align:start position:0% +this equivalently as an average over the + + + align:start position:0% +this equivalently as an average over the +data points of the maximum of F X comma + + align:start position:0% +data points of the maximum of F X comma + + + align:start position:0% +data points of the maximum of F X comma +zero and f of X comma one okay and this + + align:start position:0% +zero and f of X comma one okay and this + + + align:start position:0% +zero and f of X comma one okay and this +this simplification turning this formula + + align:start position:0% +this simplification turning this formula + + + align:start position:0% +this simplification turning this formula +into into this formula is making the + + align:start position:0% +into into this formula is making the + + + align:start position:0% +into into this formula is making the +assumption that the pie that were being + + align:start position:0% +assumption that the pie that were being + + + align:start position:0% +assumption that the pie that were being +evaluated on is precisely this pie right + + align:start position:0% +evaluated on is precisely this pie right + + + align:start position:0% +evaluated on is precisely this pie right +so this implication is only for that pie + + align:start position:0% +so this implication is only for that pie + + + align:start position:0% +so this implication is only for that pie +for another policy which is not looking + + align:start position:0% +for another policy which is not looking + + + align:start position:0% +for another policy which is not looking +at Kate or for example she might + + align:start position:0% +at Kate or for example she might + + + align:start position:0% +at Kate or for example she might +threshold Kate at a gamma it wouldn't + + align:start position:0% +threshold Kate at a gamma it wouldn't + + + align:start position:0% +threshold Kate at a gamma it wouldn't +quite be this will be something else + + align:start position:0% +quite be this will be something else + + + align:start position:0% +quite be this will be something else +okay so but I've gone a step further + + align:start position:0% +okay so but I've gone a step further + + + align:start position:0% +okay so but I've gone a step further +here right so what are what I've shown + + align:start position:0% +here right so what are what I've shown + + + align:start position:0% +here right so what are what I've shown +you right here is not the average value + + align:start position:0% +you right here is not the average value + + + align:start position:0% +you right here is not the average value +but sort of individual values where I've + + align:start position:0% +but sort of individual values where I've + + + align:start position:0% +but sort of individual values where I've +shown you the max function but what this + + align:start position:0% +shown you the max function but what this + + + align:start position:0% +shown you the max function but what this +is actually looking at is the expected + + align:start position:0% +is actually looking at is the expected + + + align:start position:0% +is actually looking at is the expected +reward which is now averaging across all + + align:start position:0% +reward which is now averaging across all + + + align:start position:0% +reward which is now averaging across all +X so to truly draw a connection between + + align:start position:0% +X so to truly draw a connection between + + + align:start position:0% +X so to truly draw a connection between +this plot we're drawing and the and the + + align:start position:0% +this plot we're drawing and the and the + + + align:start position:0% +this plot we're drawing and the and the +average reward of that policy what we + + align:start position:0% +average reward of that policy what we + + + align:start position:0% +average reward of that policy what we +should be looking at is the average of + + align:start position:0% +should be looking at is the average of + + + align:start position:0% +should be looking at is the average of +these two functions which is we'll say + + align:start position:0% +these two functions which is we'll say + + + align:start position:0% +these two functions which is we'll say +you know something something like that + + align:start position:0% +you know something something like that + + + align:start position:0% +you know something something like that +okay and that value is the expected + + align:start position:0% +okay and that value is the expected + + + align:start position:0% +okay and that value is the expected +reward now this all goes to show that + + align:start position:0% +reward now this all goes to show that + + + align:start position:0% +reward now this all goes to show that +the expected reward of this policy is + + align:start position:0% +the expected reward of this policy is + + + align:start position:0% +the expected reward of this policy is +not a quantity that we've considered in + + align:start position:0% +not a quantity that we've considered in + + + align:start position:0% +not a quantity that we've considered in +the + + align:start position:0% +the + + + align:start position:0% +the +previous lectures these not the previous + + align:start position:0% +previous lectures these not the previous + + + align:start position:0% +previous lectures these not the previous +lectures and causal inference right this + + align:start position:0% +lectures and causal inference right this + + + align:start position:0% +lectures and causal inference right this +is not the same as the average treatment + + align:start position:0% +is not the same as the average treatment + + + align:start position:0% +is not the same as the average treatment +effect for example so I'm just giving + + align:start position:0% +effect for example so I'm just giving + + + align:start position:0% +effect for example so I'm just giving +you one way to think through number one + + align:start position:0% +you one way to think through number one + + + align:start position:0% +you one way to think through number one +what is the policy that you might want + + align:start position:0% +what is the policy that you might want + + + align:start position:0% +what is the policy that you might want +to derive when you're doing causal + + align:start position:0% +to derive when you're doing causal + + + align:start position:0% +to derive when you're doing causal +inference and number two what is one way + + align:start position:0% +inference and number two what is one way + + + align:start position:0% +inference and number two what is one way +to estimate the value of that policy + + align:start position:0% +to estimate the value of that policy + + + align:start position:0% +to estimate the value of that policy +which goes through the process of + + align:start position:0% +which goes through the process of + + + align:start position:0% +which goes through the process of +estimating potential outcomes via covary + + align:start position:0% +estimating potential outcomes via covary + + + align:start position:0% +estimating potential outcomes via covary +adjustment but we might wonder just like + + align:start position:0% +adjustment but we might wonder just like + + + align:start position:0% +adjustment but we might wonder just like +when we talked about and causal + + align:start position:0% +when we talked about and causal + + + align:start position:0% +when we talked about and causal +inference where I said there are two + + align:start position:0% +inference where I said there are two + + + align:start position:0% +inference where I said there are two +approaches or these or more than two but + + align:start position:0% +approaches or these or more than two but + + + align:start position:0% +approaches or these or more than two but +we focused on two using Coverity + + align:start position:0% +we focused on two using Coverity + + + align:start position:0% +we focused on two using Coverity +adjustment and doing propensity inverse + + align:start position:0% +adjustment and doing propensity inverse + + + align:start position:0% +adjustment and doing propensity inverse +propensity score waiting you might + + align:start position:0% +propensity score waiting you might + + + align:start position:0% +propensity score waiting you might +wonder is there another approach to this + + align:start position:0% +wonder is there another approach to this + + + align:start position:0% +wonder is there another approach to this +problem altogether is there approach + + align:start position:0% +problem altogether is there approach + + + align:start position:0% +problem altogether is there approach +which wouldn't have had to go through + + align:start position:0% +which wouldn't have had to go through + + + align:start position:0% +which wouldn't have had to go through +estimating the potential outcomes and + + align:start position:0% +estimating the potential outcomes and + + + align:start position:0% +estimating the potential outcomes and +that's what I'll spend the rest of the + + align:start position:0% +that's what I'll spend the rest of the + + + align:start position:0% +that's what I'll spend the rest of the +this third of the lecture focused + + align:start position:0% +this third of the lecture focused + + + align:start position:0% +this third of the lecture focused +talking about + + align:start position:0% +talking about + + + align:start position:0% +talking about +and so to help you page this back in + + align:start position:0% +and so to help you page this back in + + + align:start position:0% +and so to help you page this back in +remember that we derived in last + + align:start position:0% +remember that we derived in last + + + align:start position:0% +remember that we derived in last +Thursday's lecture an estimator for the + + align:start position:0% +Thursday's lecture an estimator for the + + + align:start position:0% +Thursday's lecture an estimator for the +average treatment effect which was 1 + + align:start position:0% +average treatment effect which was 1 + + + align:start position:0% +average treatment effect which was 1 +over N times the sum over data points + + align:start position:0% +over N times the sum over data points + + + align:start position:0% +over N times the sum over data points +that got treatment one of why I the + + align:start position:0% +that got treatment one of why I the + + + align:start position:0% +that got treatment one of why I the +observed outcome for that data point + + align:start position:0% +observed outcome for that data point + + + align:start position:0% +observed outcome for that data point +divided by the propensity score which + + align:start position:0% +divided by the propensity score which + + + align:start position:0% +divided by the propensity score which +I'm just going to write as e I so AI is + + align:start position:0% +I'm just going to write as e I so AI is + + + align:start position:0% +I'm just going to write as e I so AI is +equal to the probability of of observing + + align:start position:0% +equal to the probability of of observing + + + align:start position:0% +equal to the probability of of observing +treat T equals T equals 1 given the data + + align:start position:0% +treat T equals T equals 1 given the data + + + align:start position:0% +treat T equals T equals 1 given the data +point X I plus sorry minus a sum over + + align:start position:0% +point X I plus sorry minus a sum over + + + align:start position:0% +point X I plus sorry minus a sum over +data points I such that T I equals 0 of + + align:start position:0% +data points I such that T I equals 0 of + + + align:start position:0% +data points I such that T I equals 0 of +Y I + + align:start position:0% +Y I + + + align:start position:0% +Y I +/ 1 - e I and by the way there was a lot + + align:start position:0% +/ 1 - e I and by the way there was a lot + + + align:start position:0% +/ 1 - e I and by the way there was a lot +of confusion in class why do I have why + + align:start position:0% +of confusion in class why do I have why + + + align:start position:0% +of confusion in class why do I have why +do they have a 1 / n here one of our n + + align:start position:0% +do they have a 1 / n here one of our n + + + align:start position:0% +do they have a 1 / n here one of our n +here but right now I just took it out + + align:start position:0% +here but right now I just took it out + + + align:start position:0% +here but right now I just took it out +all together and not one over the number + + align:start position:0% +all together and not one over the number + + + align:start position:0% +all together and not one over the number +of positive data points and one over the + + align:start position:0% +of positive data points and one over the + + + align:start position:0% +of positive data points and one over the +number of negative or zero data points + + align:start position:0% +number of negative or zero data points + + + align:start position:0% +number of negative or zero data points +and I expanded the derivation that I + + align:start position:0% +and I expanded the derivation that I + + + align:start position:0% +and I expanded the derivation that I +gave in class I posted new slides online + + align:start position:0% +gave in class I posted new slides online + + + align:start position:0% +gave in class I posted new slides online +after class so if you're curious about + + align:start position:0% +after class so if you're curious about + + + align:start position:0% +after class so if you're curious about +that go to those slides and look at the + + align:start position:0% +that go to those slides and look at the + + + align:start position:0% +that go to those slides and look at the +derivation so in a very analogous way + + align:start position:0% +derivation so in a very analogous way + + + align:start position:0% +derivation so in a very analogous way +now I'm going to give you a new + + align:start position:0% +now I'm going to give you a new + + + align:start position:0% +now I'm going to give you a new +estimator for this same quantity that I + + align:start position:0% +estimator for this same quantity that I + + + align:start position:0% +estimator for this same quantity that I +had over here the expected reward of a + + align:start position:0% +had over here the expected reward of a + + + align:start position:0% +had over here the expected reward of a +policy + + align:start position:0% +policy + + + align:start position:0% +policy +notice that this estimator here it made + + align:start position:0% +notice that this estimator here it made + + + align:start position:0% +notice that this estimator here it made +sense for any policy didn't have to be + + align:start position:0% +sense for any policy didn't have to be + + + align:start position:0% +sense for any policy didn't have to be +the policy which looked at is Kate's + + align:start position:0% +the policy which looked at is Kate's + + + align:start position:0% +the policy which looked at is Kate's +just greater than 0 or not this held for + + align:start position:0% +just greater than 0 or not this held for + + + align:start position:0% +just greater than 0 or not this held for +any policy that simplification I gave + + align:start position:0% +any policy that simplification I gave + + + align:start position:0% +any policy that simplification I gave +was only in this particular setting I'm + + align:start position:0% +was only in this particular setting I'm + + + align:start position:0% +was only in this particular setting I'm +gonna give you now another estimator for + + align:start position:0% +gonna give you now another estimator for + + + align:start position:0% +gonna give you now another estimator for +the average value of a policy which + + align:start position:0% +the average value of a policy which + + + align:start position:0% +the average value of a policy which +doesn't go through estimating potential + + align:start position:0% +doesn't go through estimating potential + + + align:start position:0% +doesn't go through estimating potential +outcomes at all and analogous to this is + + align:start position:0% +outcomes at all and analogous to this is + + + align:start position:0% +outcomes at all and analogous to this is +just going to make use of the propensity + + align:start position:0% +just going to make use of the propensity + + + align:start position:0% +just going to make use of the propensity +scores and I'll call that the I'll call + + align:start position:0% +scores and I'll call that the I'll call + + + align:start position:0% +scores and I'll call that the I'll call +it R hat now I'm going to put a + + align:start position:0% +it R hat now I'm going to put a + + + align:start position:0% +it R hat now I'm going to put a +superscript ipw for inverse propensity + + align:start position:0% +superscript ipw for inverse propensity + + + align:start position:0% +superscript ipw for inverse propensity +weighted and it's a function of Pi and + + align:start position:0% +weighted and it's a function of Pi and + + + align:start position:0% +weighted and it's a function of Pi and +it's given to you by the following + + align:start position:0% +it's given to you by the following + + + align:start position:0% +it's given to you by the following +formula 1 over n sum over the data + + align:start position:0% +formula 1 over n sum over the data + + + align:start position:0% +formula 1 over n sum over the data +points of an indicator function for if + + align:start position:0% +points of an indicator function for if + + + align:start position:0% +points of an indicator function for if +the treatment which was actually given + + align:start position:0% +the treatment which was actually given + + + align:start position:0% +the treatment which was actually given +to the eigth patient is equal to what + + align:start position:0% +to the eigth patient is equal to what + + + align:start position:0% +to the eigth patient is equal to what +the policy would have done for the ice + + align:start position:0% +the policy would have done for the ice + + + align:start position:0% +the policy would have done for the ice +patient and by the way here i'm assuming + + align:start position:0% +patient and by the way here i'm assuming + + + align:start position:0% +patient and by the way here i'm assuming +that pi is a deterministic function so + + align:start position:0% +that pi is a deterministic function so + + + align:start position:0% +that pi is a deterministic function so +it so the policy says for this patient + + align:start position:0% +it so the policy says for this patient + + + align:start position:0% +it so the policy says for this patient +you should do this treatment all right + + align:start position:0% +you should do this treatment all right + + + align:start position:0% +you should do this treatment all right +so we're gonna look at just the data + + align:start position:0% +so we're gonna look at just the data + + + align:start position:0% +so we're gonna look at just the data +points for which the observed treatment + + align:start position:0% +points for which the observed treatment + + + align:start position:0% +points for which the observed treatment +is consistent with the observed unfor + + align:start position:0% +is consistent with the observed unfor + + + align:start position:0% +is consistent with the observed unfor +that patient and this indicator function + + align:start position:0% +that patient and this indicator function + + + align:start position:0% +that patient and this indicator function +is 0 otherwise and we're going to divide + + align:start position:0% +is 0 otherwise and we're going to divide + + + align:start position:0% +is 0 otherwise and we're going to divide +it by by the probability of + + align:start position:0% + + + + align:start position:0% + +of TI given x i so the way i'm writing + + align:start position:0% +of TI given x i so the way i'm writing + + + align:start position:0% +of TI given x i so the way i'm writing +this by the way is already is very + + align:start position:0% +this by the way is already is very + + + align:start position:0% +this by the way is already is very +general so this formula will hold for + + align:start position:0% +general so this formula will hold for + + + align:start position:0% +general so this formula will hold for +for non-binary treatments as well and + + align:start position:0% +for non-binary treatments as well and + + + align:start position:0% +for non-binary treatments as well and +that's one of the really nice things + + align:start position:0% +that's one of the really nice things + + + align:start position:0% +that's one of the really nice things +about thinking about policies which is + + align:start position:0% +about thinking about policies which is + + + align:start position:0% +about thinking about policies which is +whereas when thinking about when talking + + align:start position:0% +whereas when thinking about when talking + + + align:start position:0% +whereas when thinking about when talking +about average treatment effect average + + align:start position:0% +about average treatment effect average + + + align:start position:0% +about average treatment effect average +treatment effect is sort of makes sense + + align:start position:0% +treatment effect is sort of makes sense + + + align:start position:0% +treatment effect is sort of makes sense +in the comparative sentence right + + align:start position:0% +in the comparative sentence right + + + align:start position:0% +in the comparative sentence right +comparing one to another but when we + + align:start position:0% +comparing one to another but when we + + + align:start position:0% +comparing one to another but when we +talk about how good is a policy it's + + align:start position:0% +talk about how good is a policy it's + + + align:start position:0% +talk about how good is a policy it's +it's not a comparative statement at all + + align:start position:0% +it's not a comparative statement at all + + + align:start position:0% +it's not a comparative statement at all +the policy does something for everyone + + align:start position:0% +the policy does something for everyone + + + align:start position:0% +the policy does something for everyone +you could ask well what is the average + + align:start position:0% +you could ask well what is the average + + + align:start position:0% +you could ask well what is the average +value of the outcomes that you get for + + align:start position:0% +value of the outcomes that you get for + + + align:start position:0% +value of the outcomes that you get for +those actions that we're taking for + + align:start position:0% +those actions that we're taking for + + + align:start position:0% +those actions that we're taking for +those individuals um so that's why i'm + + align:start position:0% +those individuals um so that's why i'm + + + align:start position:0% +those individuals um so that's why i'm +writing in a slightly more general + + align:start position:0% +writing in a slightly more general + + + align:start position:0% +writing in a slightly more general +fashion already here x why i obviously + + align:start position:0% +fashion already here x why i obviously + + + align:start position:0% +fashion already here x why i obviously +okay so this is now a new estimator i'm + + align:start position:0% +okay so this is now a new estimator i'm + + + align:start position:0% +okay so this is now a new estimator i'm +not going to derive it for you in class + + align:start position:0% +not going to derive it for you in class + + + align:start position:0% +not going to derive it for you in class +but the derivation is very similar to + + align:start position:0% +but the derivation is very similar to + + + align:start position:0% +but the derivation is very similar to +what we did last week when we tried to + + align:start position:0% +what we did last week when we tried to + + + align:start position:0% +what we did last week when we tried to +drive the average treatment effect and + + align:start position:0% +drive the average treatment effect and + + + align:start position:0% +drive the average treatment effect and +the critical point is were dividing by + + align:start position:0% +the critical point is were dividing by + + + align:start position:0% +the critical point is were dividing by +that propensity score just like we did + + align:start position:0% +that propensity score just like we did + + + align:start position:0% +that propensity score just like we did +over there so this if all of the + + align:start position:0% +over there so this if all of the + + + align:start position:0% +over there so this if all of the +sumption x' made sense to an infinite + + align:start position:0% +sumption x' made sense to an infinite + + + align:start position:0% +sumption x' made sense to an infinite +data should give you exactly the same + + align:start position:0% +data should give you exactly the same + + + align:start position:0% +data should give you exactly the same +estimates as this but here you're not + + align:start position:0% +estimates as this but here you're not + + + align:start position:0% +estimates as this but here you're not +estimating potential outcomes at all + + align:start position:0% +estimating potential outcomes at all + + + align:start position:0% +estimating potential outcomes at all +right so you never have to try to impute + + align:start position:0% +right so you never have to try to impute + + + align:start position:0% +right so you never have to try to impute +the the counterfactuals here all it + + align:start position:0% +the the counterfactuals here all it + + + align:start position:0% +the the counterfactuals here all it +relies on knowing is that you have the + + align:start position:0% +relies on knowing is that you have the + + + align:start position:0% +relies on knowing is that you have the +propensity scores for each of the data + + align:start position:0% +propensity scores for each of the data + + + align:start position:0% +propensity scores for each of the data +points in your training set or in a data + + align:start position:0% +points in your training set or in a data + + + align:start position:0% +points in your training set or in a data +set so for example this opens the door + + align:start position:0% +set so for example this opens the door + + + align:start position:0% +set so for example this opens the door +to tons of new exciting directions + + align:start position:0% +to tons of new exciting directions + + + align:start position:0% +to tons of new exciting directions +imagine that you had a very large + + align:start position:0% +imagine that you had a very large + + + align:start position:0% +imagine that you had a very large +observers observational data set and you + + align:start position:0% +observers observational data set and you + + + align:start position:0% +observers observational data set and you +learned a policy from it for example you + + align:start position:0% +learned a policy from it for example you + + + align:start position:0% +learned a policy from it for example you +might have done covariant adjustment and + + align:start position:0% +might have done covariant adjustment and + + + align:start position:0% +might have done covariant adjustment and +then said okay based on coverity + + align:start position:0% +then said okay based on coverity + + + align:start position:0% +then said okay based on coverity +adjustment this is my new policy so you + + align:start position:0% +adjustment this is my new policy so you + + + align:start position:0% +adjustment this is my new policy so you +might have gotten it via that approach + + align:start position:0% +might have gotten it via that approach + + + align:start position:0% +might have gotten it via that approach +and now you want to know how good is + + align:start position:0% +and now you want to know how good is + + + align:start position:0% +and now you want to know how good is +that well suppose that you then run a + + align:start position:0% +that well suppose that you then run a + + + align:start position:0% +that well suppose that you then run a +randomized control trial and then your + + align:start position:0% +randomized control trial and then your + + + align:start position:0% +randomized control trial and then your +demise control trial you have + + align:start position:0% +demise control trial you have + + + align:start position:0% +demise control trial you have +100 people maybe 200 people so not that + + align:start position:0% +100 people maybe 200 people so not that + + + align:start position:0% +100 people maybe 200 people so not that +many so not nearly enough people to have + + align:start position:0% +many so not nearly enough people to have + + + align:start position:0% +many so not nearly enough people to have +actually estimated your your policy + + align:start position:0% +actually estimated your your policy + + + align:start position:0% +actually estimated your your policy +alone right you might have needed + + align:start position:0% +alone right you might have needed + + + align:start position:0% +alone right you might have needed +thousands or millions of individuals to + + align:start position:0% +thousands or millions of individuals to + + + align:start position:0% +thousands or millions of individuals to +estimate your policy now you're only + + align:start position:0% +estimate your policy now you're only + + + align:start position:0% +estimate your policy now you're only +gonna have a couple hundred individuals + + align:start position:0% +gonna have a couple hundred individuals + + + align:start position:0% +gonna have a couple hundred individuals +that you could actually afford to do a + + align:start position:0% +that you could actually afford to do a + + + align:start position:0% +that you could actually afford to do a +randomized control trial on for those + + align:start position:0% +randomized control trial on for those + + + align:start position:0% +randomized control trial on for those +people because you're flipping a coin + + align:start position:0% +people because you're flipping a coin + + + align:start position:0% +people because you're flipping a coin +for for which cheat me they're going to + + align:start position:0% +for for which cheat me they're going to + + + align:start position:0% +for for which cheat me they're going to +get suppose that we're in a binary + + align:start position:0% +get suppose that we're in a binary + + + align:start position:0% +get suppose that we're in a binary +setting with only two treatments then + + align:start position:0% +setting with only two treatments then + + + align:start position:0% +setting with only two treatments then +this value is always one-half one-half + + align:start position:0% +this value is always one-half one-half + + + align:start position:0% +this value is always one-half one-half +and what I'm giving you here is going to + + align:start position:0% +and what I'm giving you here is going to + + + align:start position:0% +and what I'm giving you here is going to +be an unbiased estimate of how good that + + align:start position:0% +be an unbiased estimate of how good that + + + align:start position:0% +be an unbiased estimate of how good that +policy is which one can now estimate + + align:start position:0% +policy is which one can now estimate + + + align:start position:0% +policy is which one can now estimate +using that randomized control trial now + + align:start position:0% + + + + align:start position:0% + +this also might lead you to think + + align:start position:0% +this also might lead you to think + + + align:start position:0% +this also might lead you to think +through the question of well rather than + + align:start position:0% +through the question of well rather than + + + align:start position:0% +through the question of well rather than +estimating the policy through rather + + align:start position:0% +estimating the policy through rather + + + align:start position:0% +estimating the policy through rather +than obtaining a policy through the lens + + align:start position:0% +than obtaining a policy through the lens + + + align:start position:0% +than obtaining a policy through the lens +of of optimizing Kate of figuring how to + + align:start position:0% +of of optimizing Kate of figuring how to + + + align:start position:0% +of of optimizing Kate of figuring how to +estimate Kate maybe we could have + + align:start position:0% +estimate Kate maybe we could have + + + align:start position:0% +estimate Kate maybe we could have +skipped that altogether for example I + + align:start position:0% +skipped that altogether for example I + + + align:start position:0% +skipped that altogether for example I +suppose that we had that randomized + + align:start position:0% +suppose that we had that randomized + + + align:start position:0% +suppose that we had that randomized +control trial data + + align:start position:0% +control trial data + + + align:start position:0% +control trial data +now imagine that rather than 20 other + + align:start position:0% +now imagine that rather than 20 other + + + align:start position:0% +now imagine that rather than 20 other +than 100 individuals you had a really + + align:start position:0% +than 100 individuals you had a really + + + align:start position:0% +than 100 individuals you had a really +large randomized control trial with + + align:start position:0% +large randomized control trial with + + + align:start position:0% +large randomized control trial with +10,000 individuals in it this now opens + + align:start position:0% +10,000 individuals in it this now opens + + + align:start position:0% +10,000 individuals in it this now opens +the door to thinking about directly + + align:start position:0% +the door to thinking about directly + + + align:start position:0% +the door to thinking about directly +meant maximizing or minimizing depending + + align:start position:0% +meant maximizing or minimizing depending + + + align:start position:0% +meant maximizing or minimizing depending +what of what they want this to be large + + align:start position:0% +what of what they want this to be large + + + align:start position:0% +what of what they want this to be large +or small pie with respect to this + + align:start position:0% +or small pie with respect to this + + + align:start position:0% +or small pie with respect to this +quantity right which completely bypasses + + align:start position:0% +quantity right which completely bypasses + + + align:start position:0% +quantity right which completely bypasses +the goal of estimating the condition the + + align:start position:0% +the goal of estimating the condition the + + + align:start position:0% +the goal of estimating the condition the +the conditional average treatment effect + + align:start position:0% +the conditional average treatment effect + + + align:start position:0% +the conditional average treatment effect +and you'll notice how this looks exactly + + align:start position:0% +and you'll notice how this looks exactly + + + align:start position:0% +and you'll notice how this looks exactly +like a classification problem right this + + align:start position:0% +like a classification problem right this + + + align:start position:0% +like a classification problem right this +quantity here looks exactly like a 0 1 + + align:start position:0% +quantity here looks exactly like a 0 1 + + + align:start position:0% +quantity here looks exactly like a 0 1 +loss and the only difference is that + + align:start position:0% +loss and the only difference is that + + + align:start position:0% +loss and the only difference is that +you're waiting each of the data points + + align:start position:0% +you're waiting each of the data points + + + align:start position:0% +you're waiting each of the data points +by this inverse propensity so one can + + align:start position:0% +by this inverse propensity so one can + + + align:start position:0% +by this inverse propensity so one can +reduce the problem of actually finding + + align:start position:0% +reduce the problem of actually finding + + + align:start position:0% +reduce the problem of actually finding +an optimal policy here to that of a + + align:start position:0% +an optimal policy here to that of a + + + align:start position:0% +an optimal policy here to that of a +weighted classification problem in the + + align:start position:0% +weighted classification problem in the + + + align:start position:0% +weighted classification problem in the +case of a discrete set of treatments + + align:start position:0% + + + + align:start position:0% + +like big cat there are two big caveats + + align:start position:0% +like big cat there are two big caveats + + + align:start position:0% +like big cat there are two big caveats +to that line of thinking + + align:start position:0% +to that line of thinking + + + align:start position:0% +to that line of thinking +the first major caveat is that you you + + align:start position:0% +the first major caveat is that you you + + + align:start position:0% +the first major caveat is that you you +have to know these propensity scores and + + align:start position:0% +have to know these propensity scores and + + + align:start position:0% +have to know these propensity scores and +so if you have data coming from + + align:start position:0% +so if you have data coming from + + + align:start position:0% +so if you have data coming from +randomized controlled trial you will + + align:start position:0% +randomized controlled trial you will + + + align:start position:0% +randomized controlled trial you will +know those propensity scores so or or if + + align:start position:0% +know those propensity scores so or or if + + + align:start position:0% +know those propensity scores so or or if +you have for example some control over + + align:start position:0% +you have for example some control over + + + align:start position:0% +you have for example some control over +the data generation process right for + + align:start position:0% +the data generation process right for + + + align:start position:0% +the data generation process right for +example if you are a company and you're + + align:start position:0% +example if you are a company and you're + + + align:start position:0% +example if you are a company and you're +showing you get it shoes which ads to + + align:start position:0% +showing you get it shoes which ads to + + + align:start position:0% +showing you get it shoes which ads to +show to your customers then you look to + + align:start position:0% +show to your customers then you look to + + + align:start position:0% +show to your customers then you look to +see who clicks on what you might know + + align:start position:0% +see who clicks on what you might know + + + align:start position:0% +see who clicks on what you might know +what that policy was that was showing + + align:start position:0% +what that policy was that was showing + + + align:start position:0% +what that policy was that was showing +things it's right in that case you might + + align:start position:0% +things it's right in that case you might + + + align:start position:0% +things it's right in that case you might +exactly know the propensity scores in + + align:start position:0% +exactly know the propensity scores in + + + align:start position:0% +exactly know the propensity scores in +healthcare we other than in randomized + + align:start position:0% +healthcare we other than in randomized + + + align:start position:0% +healthcare we other than in randomized +control trials we typically don't know + + align:start position:0% +control trials we typically don't know + + + align:start position:0% +control trials we typically don't know +this value so we either have to have a + + align:start position:0% +this value so we either have to have a + + + align:start position:0% +this value so we either have to have a +large enough randomized control trial + + align:start position:0% +large enough randomized control trial + + + align:start position:0% +large enough randomized control trial +that we won't over fit by trying to + + align:start position:0% +that we won't over fit by trying to + + + align:start position:0% +that we won't over fit by trying to +directly minimize this or we have to + + align:start position:0% +directly minimize this or we have to + + + align:start position:0% +directly minimize this or we have to +work within an observational data + + align:start position:0% +work within an observational data + + + align:start position:0% +work within an observational data +setting but we have to estimate the + + align:start position:0% +setting but we have to estimate the + + + align:start position:0% +setting but we have to estimate the +propensity scores directly alright so + + align:start position:0% +propensity scores directly alright so + + + align:start position:0% +propensity scores directly alright so +you would then have a two-step procedure + + align:start position:0% +you would then have a two-step procedure + + + align:start position:0% +you would then have a two-step procedure +where first you estimate the propensity + + align:start position:0% +where first you estimate the propensity + + + align:start position:0% +where first you estimate the propensity +scores for example by doing logistic + + align:start position:0% +scores for example by doing logistic + + + align:start position:0% +scores for example by doing logistic +regression and then you attempt to + + align:start position:0% +regression and then you attempt to + + + align:start position:0% +regression and then you attempt to +maximize or minimize this quantity in + + align:start position:0% +maximize or minimize this quantity in + + + align:start position:0% +maximize or minimize this quantity in +order to find the optimal policy and + + align:start position:0% +order to find the optimal policy and + + + align:start position:0% +order to find the optimal policy and +that has a lot of challenges because + + align:start position:0% +that has a lot of challenges because + + + align:start position:0% +that has a lot of challenges because +this quantity shown in the very bottom + + align:start position:0% +this quantity shown in the very bottom + + + align:start position:0% +this quantity shown in the very bottom +here could be really smaller really + + align:start position:0% +here could be really smaller really + + + align:start position:0% +here could be really smaller really +large in observational data set and due + + align:start position:0% +large in observational data set and due + + + align:start position:0% +large in observational data set and due +to these issues of of having very small + + align:start position:0% +to these issues of of having very small + + + align:start position:0% +to these issues of of having very small +overlap between your treatments and this + + align:start position:0% +overlap between your treatments and this + + + align:start position:0% +overlap between your treatments and this +being very small implies then that the + + align:start position:0% +being very small implies then that the + + + align:start position:0% +being very small implies then that the +variance of this estimator is very very + + align:start position:0% +variance of this estimator is very very + + + align:start position:0% +variance of this estimator is very very +large and and so when one wants to use + + align:start position:0% +large and and so when one wants to use + + + align:start position:0% +large and and so when one wants to use +an approach like this similar to when + + align:start position:0% +an approach like this similar to when + + + align:start position:0% +an approach like this similar to when +one wants to use an average treatment + + align:start position:0% +one wants to use an average treatment + + + align:start position:0% +one wants to use an average treatment +effect estimator and when you're + + align:start position:0% +effect estimator and when you're + + + align:start position:0% +effect estimator and when you're +estimating these two propensity is often + + align:start position:0% +estimating these two propensity is often + + + align:start position:0% +estimating these two propensity is often +you might need to do things like + + align:start position:0% +you might need to do things like + + + align:start position:0% +you might need to do things like +clipping of the propensity scores in + + align:start position:0% +clipping of the propensity scores in + + + align:start position:0% +clipping of the propensity scores in +order to prevent the variance from being + + align:start position:0% +order to prevent the variance from being + + + align:start position:0% +order to prevent the variance from being +too large that then however leads to a + + align:start position:0% +too large that then however leads to a + + + align:start position:0% +too large that then however leads to a +biased estimator typically and I wanted + + align:start position:0% +biased estimator typically and I wanted + + + align:start position:0% +biased estimator typically and I wanted +to give you a couple of references here + + align:start position:0% +to give you a couple of references here + + + align:start position:0% +to give you a couple of references here +so one is Swami + + align:start position:0% +so one is Swami + + + align:start position:0% +so one is Swami +nothin and jokey-joke UM's J Oh a CH IMS + + align:start position:0% +nothin and jokey-joke UM's J Oh a CH IMS + + + align:start position:0% +nothin and jokey-joke UM's J Oh a CH IMS +ICML 2015 in that paper they tackle this + + align:start position:0% +ICML 2015 in that paper they tackle this + + + align:start position:0% +ICML 2015 in that paper they tackle this +question they focus on the setting where + + align:start position:0% +question they focus on the setting where + + + align:start position:0% +question they focus on the setting where +the propensity scores are known such as + + align:start position:0% +the propensity scores are known such as + + + align:start position:0% +the propensity scores are known such as +you would have from a randomized control + + align:start position:0% +you would have from a randomized control + + + align:start position:0% +you would have from a randomized control +trial and they recognize that you might + + align:start position:0% +trial and they recognize that you might + + + align:start position:0% +trial and they recognize that you might +decide that you want you prefer it + + align:start position:0% +decide that you want you prefer it + + + align:start position:0% +decide that you want you prefer it +something like a biased estimator + + align:start position:0% +something like a biased estimator + + + align:start position:0% +something like a biased estimator +because of the fact that these + + align:start position:0% +because of the fact that these + + + align:start position:0% +because of the fact that these +propensity scores could be really small + + align:start position:0% +propensity scores could be really small + + + align:start position:0% +propensity scores could be really small +and so they use some generalization + + align:start position:0% +and so they use some generalization + + + align:start position:0% +and so they use some generalization +results from the machine learning theory + + align:start position:0% +results from the machine learning theory + + + align:start position:0% +results from the machine learning theory +community in order to try to control the + + align:start position:0% +community in order to try to control the + + + align:start position:0% +community in order to try to control the +variance of the estimator as a function + + align:start position:0% +variance of the estimator as a function + + + align:start position:0% +variance of the estimator as a function +of these propensity scores and then they + + align:start position:0% +of these propensity scores and then they + + + align:start position:0% +of these propensity scores and then they +then learn directly minimise the policy + + align:start position:0% +then learn directly minimise the policy + + + align:start position:0% +then learn directly minimise the policy +which is what they call counterfactual + + align:start position:0% +which is what they call counterfactual + + + align:start position:0% +which is what they call counterfactual +regrettin minimization in order to in + + align:start position:0% +regrettin minimization in order to in + + + align:start position:0% +regrettin minimization in order to in +order to allow one to generalize as best + + align:start position:0% +order to allow one to generalize as best + + + align:start position:0% +order to allow one to generalize as best +as possible from sort of the small + + align:start position:0% +as possible from sort of the small + + + align:start position:0% +as possible from sort of the small +amount of data you might have available + + align:start position:0% +amount of data you might have available + + + align:start position:0% +amount of data you might have available +the second reference that I want to give + + align:start position:0% +the second reference that I want to give + + + align:start position:0% +the second reference that I want to give +just to point you into this literature + + align:start position:0% +just to point you into this literature + + + align:start position:0% +just to point you into this literature +if you're interested is by Nathan + + align:start position:0% +if you're interested is by Nathan + + + align:start position:0% +if you're interested is by Nathan +callous and his student I believe Angela + + align:start position:0% +callous and his student I believe Angela + + + align:start position:0% +callous and his student I believe Angela +Zhu from Europe's 2018 and that was a + + align:start position:0% +Zhu from Europe's 2018 and that was a + + + align:start position:0% +Zhu from Europe's 2018 and that was a +paper which was one of the optional + + align:start position:0% +paper which was one of the optional + + + align:start position:0% +paper which was one of the optional +readings for last Thursday's class now + + align:start position:0% +readings for last Thursday's class now + + + align:start position:0% +readings for last Thursday's class now +that paper they also start from + + align:start position:0% +that paper they also start from + + + align:start position:0% +that paper they also start from +something like this from this + + align:start position:0% +something like this from this + + + align:start position:0% +something like this from this +perspective and they say that oh now + + align:start position:0% +perspective and they say that oh now + + + align:start position:0% +perspective and they say that oh now +that you have we're working in this + + align:start position:0% +that you have we're working in this + + + align:start position:0% +that you have we're working in this +framework one could think about what + + align:start position:0% +framework one could think about what + + + align:start position:0% +framework one could think about what +happens if you have actually unobserved + + align:start position:0% +happens if you have actually unobserved + + + align:start position:0% +happens if you have actually unobserved +confounding so there you might not + + align:start position:0% +confounding so there you might not + + + align:start position:0% +confounding so there you might not +actually know the true propensity scores + + align:start position:0% +actually know the true propensity scores + + + align:start position:0% +actually know the true propensity scores +because there are unobserved confounders + + align:start position:0% +because there are unobserved confounders + + + align:start position:0% +because there are unobserved confounders +that you don't observe and that you can + + align:start position:0% +that you don't observe and that you can + + + align:start position:0% +that you don't observe and that you can +think about trying to bound how how + + align:start position:0% +think about trying to bound how how + + + align:start position:0% +think about trying to bound how how +wrong your estimator can be as a + + align:start position:0% +wrong your estimator can be as a + + + align:start position:0% +wrong your estimator can be as a +function of how much you don't know this + + align:start position:0% +function of how much you don't know this + + + align:start position:0% +function of how much you don't know this +quantity and they show that when you try + + align:start position:0% +quantity and they show that when you try + + + align:start position:0% +quantity and they show that when you try +to if you think about having some backup + + align:start position:0% +to if you think about having some backup + + + align:start position:0% +to if you think about having some backup +strategy like if your goal is to find a + + align:start position:0% +strategy like if your goal is to find a + + + align:start position:0% +strategy like if your goal is to find a +new policy which performs as best as + + align:start position:0% +new policy which performs as best as + + + align:start position:0% +new policy which performs as best as +possible with respect to an old policy + + align:start position:0% +possible with respect to an old policy + + + align:start position:0% +possible with respect to an old policy +then it gives you a really elegant + + align:start position:0% +then it gives you a really elegant + + + align:start position:0% +then it gives you a really elegant +framework for trying to think about a + + align:start position:0% +framework for trying to think about a + + + align:start position:0% +framework for trying to think about a +robust optimization of this even taking + + align:start position:0% +robust optimization of this even taking + + + align:start position:0% +robust optimization of this even taking +the fact that there might be an observed + + align:start position:0% +the fact that there might be an observed + + + align:start position:0% +the fact that there might be an observed +confounding and that worked oh so in + + align:start position:0% +confounding and that worked oh so in + + + align:start position:0% +confounding and that worked oh so in +this in this framework so I'm nearly + + align:start position:0% +this in this framework so I'm nearly + + + align:start position:0% +this in this framework so I'm nearly +done now + + align:start position:0% +done now + + + align:start position:0% +done now +I just want to now finish with the + + align:start position:0% +I just want to now finish with the + + + align:start position:0% +I just want to now finish with the +thought can we do the same thing for + + align:start position:0% +thought can we do the same thing for + + + align:start position:0% +thought can we do the same thing for +policies learned by reinforcement + + align:start position:0% +policies learned by reinforcement + + + align:start position:0% +policies learned by reinforcement +learning + + align:start position:0% +learning + + + align:start position:0% +learning +so now let's now that we've sort of + + align:start position:0% +so now let's now that we've sort of + + + align:start position:0% +so now let's now that we've sort of +built up this language let's return to + + align:start position:0% +built up this language let's return to + + + align:start position:0% +built up this language let's return to +the RL setting and there one can show + + align:start position:0% +the RL setting and there one can show + + + align:start position:0% +the RL setting and there one can show +that you can get a similar estimate for + + align:start position:0% +that you can get a similar estimate for + + + align:start position:0% +that you can get a similar estimate for +the value of a policy by summing over + + align:start position:0% +the value of a policy by summing over + + + align:start position:0% +the value of a policy by summing over +your observed sequences summing over the + + align:start position:0% +your observed sequences summing over the + + + align:start position:0% +your observed sequences summing over the +time steps of that sequence of the + + align:start position:0% +time steps of that sequence of the + + + align:start position:0% +time steps of that sequence of the +reward observed at that time step times + + align:start position:0% +reward observed at that time step times + + + align:start position:0% +reward observed at that time step times +a ratio of probabilities which is going + + align:start position:0% +a ratio of probabilities which is going + + + align:start position:0% +a ratio of probabilities which is going +from the first time step up to time + + align:start position:0% +from the first time step up to time + + + align:start position:0% +from the first time step up to time +little T of the probability that you + + align:start position:0% +little T of the probability that you + + + align:start position:0% +little T of the probability that you +would actually take the observed action + + align:start position:0% +would actually take the observed action + + + align:start position:0% +would actually take the observed action +T prime given that you were in the + + align:start position:0% +T prime given that you were in the + + + align:start position:0% +T prime given that you were in the +observe state T prime divided by the + + align:start position:0% +observe state T prime divided by the + + + align:start position:0% +observe state T prime divided by the +probability this is where this is the + + align:start position:0% +probability this is where this is the + + + align:start position:0% +probability this is where this is the +knowledge of the propensity score the + + align:start position:0% +knowledge of the propensity score the + + + align:start position:0% +knowledge of the propensity score the +probability under the data generating + + align:start position:0% +probability under the data generating + + + align:start position:0% +probability under the data generating +process of of seeing action a given that + + align:start position:0% +process of of seeing action a given that + + + align:start position:0% +process of of seeing action a given that +you're in state T prime so if as we + + align:start position:0% +you're in state T prime so if as we + + + align:start position:0% +you're in state T prime so if as we +discussed there you had a deterministic + + align:start position:0% +discussed there you had a deterministic + + + align:start position:0% +discussed there you had a deterministic +policy then this PI would it would just + + align:start position:0% +policy then this PI would it would just + + + align:start position:0% +policy then this PI would it would just +be a delta function and so this would + + align:start position:0% +be a delta function and so this would + + + align:start position:0% +be a delta function and so this would +just be looking at what this would this + + align:start position:0% +just be looking at what this would this + + + align:start position:0% +just be looking at what this would this +estimator would only be looking at + + align:start position:0% +estimator would only be looking at + + + align:start position:0% +estimator would only be looking at +sequences where the precise sequence of + + align:start position:0% +sequences where the precise sequence of + + + align:start position:0% +sequences where the precise sequence of +actions taken are identical to the + + align:start position:0% +actions taken are identical to the + + + align:start position:0% +actions taken are identical to the +precise sequence of actions that the + + align:start position:0% +precise sequence of actions that the + + + align:start position:0% +precise sequence of actions that the +policy would have taken and the + + align:start position:0% +policy would have taken and the + + + align:start position:0% +policy would have taken and the +difference here is that now instead of + + align:start position:0% +difference here is that now instead of + + + align:start position:0% +difference here is that now instead of +having a single propensity score one has + + align:start position:0% +having a single propensity score one has + + + align:start position:0% +having a single propensity score one has +a product of these propensity scores + + align:start position:0% +a product of these propensity scores + + + align:start position:0% +a product of these propensity scores +corresponding to the propensity of + + align:start position:0% +corresponding to the propensity of + + + align:start position:0% +corresponding to the propensity of +observing that action given the + + align:start position:0% +observing that action given the + + + align:start position:0% +observing that action given the +corresponding state at each point along + + align:start position:0% +corresponding state at each point along + + + align:start position:0% +corresponding state at each point along +the sequence and so this is nice because + + align:start position:0% +the sequence and so this is nice because + + + align:start position:0% +the sequence and so this is nice because +this gives you one way to do what's + + align:start position:0% +this gives you one way to do what's + + + align:start position:0% +this gives you one way to do what's +called off policy evaluation + + align:start position:0% + + + + align:start position:0% + +and this is an estimator which is I + + align:start position:0% +and this is an estimator which is I + + + align:start position:0% +and this is an estimator which is I +which is a completely analogous to the + + align:start position:0% +which is a completely analogous to the + + + align:start position:0% +which is a completely analogous to the +estimator that we got from q-learning + + align:start position:0% +estimator that we got from q-learning + + + align:start position:0% +estimator that we got from q-learning +so if all assumptions were correct and + + align:start position:0% +so if all assumptions were correct and + + + align:start position:0% +so if all assumptions were correct and +you had a lot of data then those two + + align:start position:0% +you had a lot of data then those two + + + align:start position:0% +you had a lot of data then those two +should give you precisely the same + + align:start position:0% +should give you precisely the same + + + align:start position:0% +should give you precisely the same +answer but here like in the causal + + align:start position:0% +answer but here like in the causal + + + align:start position:0% +answer but here like in the causal +inference setting we are not making the + + align:start position:0% +inference setting we are not making the + + + align:start position:0% +inference setting we are not making the +assumption that we can do Co very two + + align:start position:0% +assumption that we can do Co very two + + + align:start position:0% +assumption that we can do Co very two +adjustment well or said differently + + align:start position:0% +adjustment well or said differently + + + align:start position:0% +adjustment well or said differently +we're not assuming that we can fit the Q + + align:start position:0% +we're not assuming that we can fit the Q + + + align:start position:0% +we're not assuming that we can fit the Q +function well and this is now just just + + align:start position:0% +function well and this is now just just + + + align:start position:0% +function well and this is now just just +like they're based on the assumption + + align:start position:0% +like they're based on the assumption + + + align:start position:0% +like they're based on the assumption +that we have the ability to really + + align:start position:0% +that we have the ability to really + + + align:start position:0% +that we have the ability to really +accurately know what the propensity + + align:start position:0% +accurately know what the propensity + + + align:start position:0% +accurately know what the propensity +scores are so it now gives you an + + align:start position:0% +scores are so it now gives you an + + + align:start position:0% +scores are so it now gives you an +alternative approach to do evaluation + + align:start position:0% +alternative approach to do evaluation + + + align:start position:0% +alternative approach to do evaluation +and you could think about looking for + + align:start position:0% +and you could think about looking for + + + align:start position:0% +and you could think about looking for +the robustness of your estimates from + + align:start position:0% +the robustness of your estimates from + + + align:start position:0% +the robustness of your estimates from +these two different different estimators + + align:start position:0% +these two different different estimators + + + align:start position:0% +these two different different estimators +and here if you're and there this is the + + align:start position:0% +and here if you're and there this is the + + + align:start position:0% +and here if you're and there this is the +most naive of des tomaters there are + + align:start position:0% +most naive of des tomaters there are + + + align:start position:0% +most naive of des tomaters there are +many ways to try to try to make this + + align:start position:0% +many ways to try to try to make this + + + align:start position:0% +many ways to try to try to make this +better + + align:start position:0% +better + + + align:start position:0% +better +such as by by doing wo bust estimators + + align:start position:0% +such as by by doing wo bust estimators + + + align:start position:0% +such as by by doing wo bust estimators +and if you want to learn more I + + align:start position:0% +and if you want to learn more I + + + align:start position:0% +and if you want to learn more I +recommend reading this paper by Thomas + + align:start position:0% +recommend reading this paper by Thomas + + + align:start position:0% +recommend reading this paper by Thomas +and I'm a Brun skill and I CML 2016 and + + align:start position:0% +and I'm a Brun skill and I CML 2016 and + + + align:start position:0% +and I'm a Brun skill and I CML 2016 and +with that I want Barbara to come up and + + align:start position:0% +with that I want Barbara to come up and + + + align:start position:0% +with that I want Barbara to come up and +get set up and we're going to transition + + align:start position:0% +get set up and we're going to transition + + + align:start position:0% +get set up and we're going to transition +to the next part of the lecture yes one + + align:start position:0% +to the next part of the lecture yes one + + + align:start position:0% +to the next part of the lecture yes one +easy way to think about this is suppose + + align:start position:0% +easy way to think about this is suppose + + + align:start position:0% +easy way to think about this is suppose +that you only had a reward at the last + + align:start position:0% +that you only had a reward at the last + + + align:start position:0% +that you only had a reward at the last +time step if you only had a reward of + + align:start position:0% +time step if you only had a reward of + + + align:start position:0% +time step if you only had a reward of +the last time step then you wouldn't + + align:start position:0% +the last time step then you wouldn't + + + align:start position:0% +the last time step then you wouldn't +have this sum over T because the rewards + + align:start position:0% +have this sum over T because the rewards + + + align:start position:0% +have this sum over T because the rewards +in the earlier steps would be zero + + align:start position:0% +in the earlier steps would be zero + + + align:start position:0% +in the earlier steps would be zero +you would just have that product going + + align:start position:0% +you would just have that product going + + + align:start position:0% +you would just have that product going +from zero up to capital T the last time + + align:start position:0% +from zero up to capital T the last time + + + align:start position:0% +from zero up to capital T the last time +step the reason why you have it up to at + + align:start position:0% +step the reason why you have it up to at + + + align:start position:0% +step the reason why you have it up to at +each time step is because one wants to + + align:start position:0% +each time step is because one wants to + + + align:start position:0% +each time step is because one wants to +be able to appropriately way the likely + + align:start position:0% +be able to appropriately way the likely + + + align:start position:0% +be able to appropriately way the likely +in essence the likelihood of seeing that + + align:start position:0% +in essence the likelihood of seeing that + + + align:start position:0% +in essence the likelihood of seeing that +reward at that point in time one could + + align:start position:0% +reward at that point in time one could + + + align:start position:0% +reward at that point in time one could +rewrite this in other ways I want to + + align:start position:0% +rewrite this in other ways I want to + + + align:start position:0% +rewrite this in other ways I want to +hold other questions because this part + + align:start position:0% +hold other questions because this part + + + align:start position:0% +hold other questions because this part +of lecture is gonna be much more + + align:start position:0% +of lecture is gonna be much more + + + align:start position:0% +of lecture is gonna be much more +interesting than my part of lecture + + align:start position:0% +interesting than my part of lecture + + + align:start position:0% +interesting than my part of lecture +and with that I want to introduce + + align:start position:0% +and with that I want to introduce + + + align:start position:0% +and with that I want to introduce +Barbara Barbara I first met her when she + + align:start position:0% +Barbara Barbara I first met her when she + + + align:start position:0% +Barbara Barbara I first met her when she +invited me to give a talk in her class + + align:start position:0% +invited me to give a talk in her class + + + align:start position:0% +invited me to give a talk in her class +last year she is an instructor at at + + align:start position:0% +last year she is an instructor at at + + + align:start position:0% +last year she is an instructor at at +harvard medical school or School of + + align:start position:0% +harvard medical school or School of + + + align:start position:0% +harvard medical school or School of +Public Health and she recently finished + + align:start position:0% +Public Health and she recently finished + + + align:start position:0% +Public Health and she recently finished +her PhD in 2018 + + align:start position:0% +her PhD in 2018 + + + align:start position:0% +her PhD in 2018 +and her PhD looked at many questions + + align:start position:0% +and her PhD looked at many questions + + + align:start position:0% +and her PhD looked at many questions +related to the themes of the last couple + + align:start position:0% +related to the themes of the last couple + + + align:start position:0% +related to the themes of the last couple +of weeks since that time in addition to + + align:start position:0% +of weeks since that time in addition to + + + align:start position:0% +of weeks since that time in addition to +continue her research + + align:start position:0% +continue her research + + + align:start position:0% +continue her research +she's been really leading the way in + + align:start position:0% +she's been really leading the way in + + + align:start position:0% +she's been really leading the way in +creating data science curriculum over at + + align:start position:0% +creating data science curriculum over at + + + align:start position:0% +creating data science curriculum over at +Harvard so please take away thank you so + + align:start position:0% +Harvard so please take away thank you so + + + align:start position:0% +Harvard so please take away thank you so +much for the introduction David I'm very + + align:start position:0% +much for the introduction David I'm very + + + align:start position:0% +much for the introduction David I'm very +happy to be here to share some of my + + align:start position:0% +happy to be here to share some of my + + + align:start position:0% +happy to be here to share some of my +work on evaluating dynamic treatment + + align:start position:0% +work on evaluating dynamic treatment + + + align:start position:0% +work on evaluating dynamic treatment +strategies which you've been talking + + align:start position:0% +strategies which you've been talking + + + align:start position:0% +strategies which you've been talking +about over the past few lectures so my + + align:start position:0% +about over the past few lectures so my + + + align:start position:0% +about over the past few lectures so my +goals for today I'm just gonna breeze + + align:start position:0% +goals for today I'm just gonna breeze + + + align:start position:0% +goals for today I'm just gonna breeze +over defining dynamic treatment + + align:start position:0% +over defining dynamic treatment + + + align:start position:0% +over defining dynamic treatment +strategies as you're already familiar + + align:start position:0% +strategies as you're already familiar + + + align:start position:0% +strategies as you're already familiar +with it but I would like to touch on + + align:start position:0% +with it but I would like to touch on + + + align:start position:0% +with it but I would like to touch on +when we need a special class of methods + + align:start position:0% +when we need a special class of methods + + + align:start position:0% +when we need a special class of methods +called G methods and then we'll talk + + align:start position:0% +called G methods and then we'll talk + + + align:start position:0% +called G methods and then we'll talk +about two different applications + + align:start position:0% +about two different applications + + + align:start position:0% +about two different applications +different analyses that have focused on + + align:start position:0% +different analyses that have focused on + + + align:start position:0% +different analyses that have focused on +evaluating dynamic treatment strategies + + align:start position:0% +evaluating dynamic treatment strategies + + + align:start position:0% +evaluating dynamic treatment strategies +so the first will be an application of + + align:start position:0% +so the first will be an application of + + + align:start position:0% +so the first will be an application of +the parametric G formula which is a + + align:start position:0% +the parametric G formula which is a + + + align:start position:0% +the parametric G formula which is a +powerful G method to cancer research and + + align:start position:0% +powerful G method to cancer research and + + + align:start position:0% +powerful G method to cancer research and +so the goal here is to give you my + + align:start position:0% +so the goal here is to give you my + + + align:start position:0% +so the goal here is to give you my +causal inference perspective on how we + + align:start position:0% +causal inference perspective on how we + + + align:start position:0% +causal inference perspective on how we +think about this task of sequential + + align:start position:0% +think about this task of sequential + + + align:start position:0% +think about this task of sequential +decision making and then with whatever + + align:start position:0% +decision making and then with whatever + + + align:start position:0% +decision making and then with whatever +time remains will be discussing a recent + + align:start position:0% +time remains will be discussing a recent + + + align:start position:0% +time remains will be discussing a recent +publication on the AI clinician to talk + + align:start position:0% +publication on the AI clinician to talk + + + align:start position:0% +publication on the AI clinician to talk +through the reinforcement learning + + align:start position:0% +through the reinforcement learning + + + align:start position:0% +through the reinforcement learning +perspective so I think it'll be a really + + align:start position:0% +perspective so I think it'll be a really + + + align:start position:0% +perspective so I think it'll be a really +interesting discussion where we can + + align:start position:0% +interesting discussion where we can + + + align:start position:0% +interesting discussion where we can +share these perspectives talk about the + + align:start position:0% +share these perspectives talk about the + + + align:start position:0% +share these perspectives talk about the +relative strengths and limitations as + + align:start position:0% +relative strengths and limitations as + + + align:start position:0% +relative strengths and limitations as +well and please stop me if you have any + + align:start position:0% +well and please stop me if you have any + + + align:start position:0% +well and please stop me if you have any +questions so you already know this when + + align:start position:0% +questions so you already know this when + + + align:start position:0% +questions so you already know this when +it comes to treatment strategies there's + + align:start position:0% +it comes to treatment strategies there's + + + align:start position:0% +it comes to treatment strategies there's +three main types there's point + + align:start position:0% +three main types there's point + + + align:start position:0% +three main types there's point +interventions happening at a single + + align:start position:0% +interventions happening at a single + + + align:start position:0% +interventions happening at a single +point in time there's sustained + + align:start position:0% +point in time there's sustained + + + align:start position:0% +point in time there's sustained +interventions happening over time when + + align:start position:0% +interventions happening over time when + + + align:start position:0% +interventions happening over time when +it comes to clinical care this is often + + align:start position:0% +it comes to clinical care this is often + + + align:start position:0% +it comes to clinical care this is often +what we're most interested in within + + align:start position:0% +what we're most interested in within + + + align:start position:0% +what we're most interested in within +that there's static strategies which are + + align:start position:0% +that there's static strategies which are + + + align:start position:0% +that there's static strategies which are +constant over time and then there's + + align:start position:0% +constant over time and then there's + + + align:start position:0% +constant over time and then there's +dynamic strategies which we're going to + + align:start position:0% +dynamic strategies which we're going to + + + align:start position:0% +dynamic strategies which we're going to +focus on + + align:start position:0% +focus on + + + align:start position:0% +focus on +and these differ in that the + + align:start position:0% +and these differ in that the + + + align:start position:0% +and these differ in that the +intervention over time depends on + + align:start position:0% +intervention over time depends on + + + align:start position:0% +intervention over time depends on +evolving characteristics so for example + + align:start position:0% +evolving characteristics so for example + + + align:start position:0% +evolving characteristics so for example +initiate treatment at baseline and + + align:start position:0% +initiate treatment at baseline and + + + align:start position:0% +initiate treatment at baseline and +continue it over follow-up until a + + align:start position:0% +continue it over follow-up until a + + + align:start position:0% +continue it over follow-up until a +contraindication occurs at which point + + align:start position:0% +contraindication occurs at which point + + + align:start position:0% +contraindication occurs at which point +you may stop treatment and decide with + + align:start position:0% +you may stop treatment and decide with + + + align:start position:0% +you may stop treatment and decide with +your doctor whether you're going to + + align:start position:0% +your doctor whether you're going to + + + align:start position:0% +your doctor whether you're going to +switch to an alternate treatment you + + align:start position:0% +switch to an alternate treatment you + + + align:start position:0% +switch to an alternate treatment you +would still be adhering to that strategy + + align:start position:0% +would still be adhering to that strategy + + + align:start position:0% +would still be adhering to that strategy +even though you quit the comparison here + + align:start position:0% +even though you quit the comparison here + + + align:start position:0% +even though you quit the comparison here +being do not initiate treatment over + + align:start position:0% +being do not initiate treatment over + + + align:start position:0% +being do not initiate treatment over +follow-up + + align:start position:0% +follow-up + + + align:start position:0% +follow-up +likewise unless an indication occurs at + + align:start position:0% +likewise unless an indication occurs at + + + align:start position:0% +likewise unless an indication occurs at +which point you may start treatment and + + align:start position:0% +which point you may start treatment and + + + align:start position:0% +which point you may start treatment and +still be adhering to the strategy so + + align:start position:0% +still be adhering to the strategy so + + + align:start position:0% +still be adhering to the strategy so +we're focusing on these because they're + + align:start position:0% +we're focusing on these because they're + + + align:start position:0% +we're focusing on these because they're +the most clinically relevant and so + + align:start position:0% +the most clinically relevant and so + + + align:start position:0% +the most clinically relevant and so +clinicians encounter these every day in + + align:start position:0% +clinicians encounter these every day in + + + align:start position:0% +clinicians encounter these every day in +practice so when they're making a + + align:start position:0% +practice so when they're making a + + + align:start position:0% +practice so when they're making a +recommendation to their patient about a + + align:start position:0% +recommendation to their patient about a + + + align:start position:0% +recommendation to their patient about a +prevention intervention they're going to + + align:start position:0% +prevention intervention they're going to + + + align:start position:0% +prevention intervention they're going to +be taking into consideration the + + align:start position:0% +be taking into consideration the + + + align:start position:0% +be taking into consideration the +patient's evolving comorbidities or when + + align:start position:0% +patient's evolving comorbidities or when + + + align:start position:0% +patient's evolving comorbidities or when +they're deciding the next screening + + align:start position:0% +they're deciding the next screening + + + align:start position:0% +they're deciding the next screening +interval they'll consider the previous + + align:start position:0% +interval they'll consider the previous + + + align:start position:0% +interval they'll consider the previous +result from the last screening test when + + align:start position:0% +result from the last screening test when + + + align:start position:0% +result from the last screening test when +deciding that likewise for treatment + + align:start position:0% +deciding that likewise for treatment + + + align:start position:0% +deciding that likewise for treatment +deciding whether to keep the patient on + + align:start position:0% +deciding whether to keep the patient on + + + align:start position:0% +deciding whether to keep the patient on +treatment or not is the patient having + + align:start position:0% +treatment or not is the patient having + + + align:start position:0% +treatment or not is the patient having +any changes in symptoms or lab values + + align:start position:0% +any changes in symptoms or lab values + + + align:start position:0% +any changes in symptoms or lab values +that may reflect toxicity so one thing + + align:start position:0% +that may reflect toxicity so one thing + + + align:start position:0% +that may reflect toxicity so one thing +to note is that while many of the + + align:start position:0% +to note is that while many of the + + + align:start position:0% +to note is that while many of the +strategies that you may see in clinical + + align:start position:0% +strategies that you may see in clinical + + + align:start position:0% +strategies that you may see in clinical +guidelines and in clinical practice our + + align:start position:0% +guidelines and in clinical practice our + + + align:start position:0% +guidelines and in clinical practice our +dynamic strategies these may not be the + + align:start position:0% +dynamic strategies these may not be the + + + align:start position:0% +dynamic strategies these may not be the +optimal strategies so maybe what we're + + align:start position:0% +optimal strategies so maybe what we're + + + align:start position:0% +optimal strategies so maybe what we're +recommending and doing is not optimal + + align:start position:0% +recommending and doing is not optimal + + + align:start position:0% +recommending and doing is not optimal +for patients however the optimal + + align:start position:0% +for patients however the optimal + + + align:start position:0% +for patients however the optimal +strategies will be dynamic in some way + + align:start position:0% +strategies will be dynamic in some way + + + align:start position:0% +strategies will be dynamic in some way +in that they will be adapting to + + align:start position:0% +in that they will be adapting to + + + align:start position:0% +in that they will be adapting to +individuals unique and evolving + + align:start position:0% +individuals unique and evolving + + + align:start position:0% +individuals unique and evolving +characteristics so that's why we care + + align:start position:0% +characteristics so that's why we care + + + align:start position:0% +characteristics so that's why we care +about them so what's the problem so one + + align:start position:0% +about them so what's the problem so one + + + align:start position:0% +about them so what's the problem so one +problem deals with something called + + align:start position:0% +problem deals with something called + + + align:start position:0% +problem deals with something called +treatment confounder feedback which you + + align:start position:0% +treatment confounder feedback which you + + + align:start position:0% +treatment confounder feedback which you +may have spoken about in this class so + + align:start position:0% +may have spoken about in this class so + + + align:start position:0% +may have spoken about in this class so +conventional statistical methods cannot + + align:start position:0% +conventional statistical methods cannot + + + align:start position:0% +conventional statistical methods cannot +appropriately compare dynamic treatment + + align:start position:0% +appropriately compare dynamic treatment + + + align:start position:0% +appropriately compare dynamic treatment +strategies in the presence of treatment + + align:start position:0% +strategies in the presence of treatment + + + align:start position:0% +strategies in the presence of treatment +confounder feedback so this is when time + + align:start position:0% +confounder feedback so this is when time + + + align:start position:0% +confounder feedback so this is when time +varying confounders are affected by + + align:start position:0% +varying confounders are affected by + + + align:start position:0% +varying confounders are affected by +previous treatment so if we kind of + + align:start position:0% +previous treatment so if we kind of + + + align:start position:0% +previous treatment so if we kind of +ground this in a concrete example with + + align:start position:0% +ground this in a concrete example with + + + align:start position:0% +ground this in a concrete example with +this causal diagram let's say we're + + align:start position:0% +this causal diagram let's say we're + + + align:start position:0% +this causal diagram let's say we're +interested in s2 + + align:start position:0% +interested in s2 + + + align:start position:0% +interested in s2 +the effect of some intervention a + + align:start position:0% +the effect of some intervention a + + + align:start position:0% +the effect of some intervention a +vasopressors or it could be IV fluids on + + align:start position:0% +vasopressors or it could be IV fluids on + + + align:start position:0% +vasopressors or it could be IV fluids on +some outcome y which we'll call survival + + align:start position:0% +some outcome y which we'll call survival + + + align:start position:0% +some outcome y which we'll call survival +here we know that vasopressors affect + + align:start position:0% +here we know that vasopressors affect + + + align:start position:0% +here we know that vasopressors affect +blood pressure and blood pressure will + + align:start position:0% +blood pressure and blood pressure will + + + align:start position:0% +blood pressure and blood pressure will +affect subsequent decisions to treat + + align:start position:0% +affect subsequent decisions to treat + + + align:start position:0% +affect subsequent decisions to treat +with vasopressors we also know that + + align:start position:0% +with vasopressors we also know that + + + align:start position:0% +with vasopressors we also know that +hypotension so again blood pressure l1 + + align:start position:0% +hypotension so again blood pressure l1 + + + align:start position:0% +hypotension so again blood pressure l1 +affects survival based on our clinical + + align:start position:0% +affects survival based on our clinical + + + align:start position:0% +affects survival based on our clinical +knowledge and then in this dag we also + + align:start position:0% +knowledge and then in this dag we also + + + align:start position:0% +knowledge and then in this dag we also +have the node U which represents disease + + align:start position:0% +have the node U which represents disease + + + align:start position:0% +have the node U which represents disease +severity so these could be potentially + + align:start position:0% +severity so these could be potentially + + + align:start position:0% +severity so these could be potentially +unmeasured markers of disease severity + + align:start position:0% +unmeasured markers of disease severity + + + align:start position:0% +unmeasured markers of disease severity +that are affecting your blood pressure + + align:start position:0% +that are affecting your blood pressure + + + align:start position:0% +that are affecting your blood pressure +and also affecting your probability of + + align:start position:0% +and also affecting your probability of + + + align:start position:0% +and also affecting your probability of +survival so if we're interested in + + align:start position:0% +survival so if we're interested in + + + align:start position:0% +survival so if we're interested in +estimating the effect of a sustained + + align:start position:0% +estimating the effect of a sustained + + + align:start position:0% +estimating the effect of a sustained +treatment strategy then we want to know + + align:start position:0% +treatment strategy then we want to know + + + align:start position:0% +treatment strategy then we want to know +something about the total effective + + align:start position:0% +something about the total effective + + + align:start position:0% +something about the total effective +treatment at all time points we can see + + align:start position:0% +treatment at all time points we can see + + + align:start position:0% +treatment at all time points we can see +that l1 here is a confounder for the + + align:start position:0% +that l1 here is a confounder for the + + + align:start position:0% +that l1 here is a confounder for the +effect of a1 on Y so we have to do + + align:start position:0% +effect of a1 on Y so we have to do + + + align:start position:0% +effect of a1 on Y so we have to do +something to adjust for that and if we + + align:start position:0% +something to adjust for that and if we + + + align:start position:0% +something to adjust for that and if we +were to apply a conventional statistical + + align:start position:0% +were to apply a conventional statistical + + + align:start position:0% +were to apply a conventional statistical +method we would essentially be + + align:start position:0% +method we would essentially be + + + align:start position:0% +method we would essentially be +conditioning on a Collider and inducing + + align:start position:0% +conditioning on a Collider and inducing + + + align:start position:0% +conditioning on a Collider and inducing +a selection bias so an open path from a + + align:start position:0% +a selection bias so an open path from a + + + align:start position:0% +a selection bias so an open path from a +0 to L 1 to u 2 y what's the consequence + + align:start position:0% +0 to L 1 to u 2 y what's the consequence + + + align:start position:0% +0 to L 1 to u 2 y what's the consequence +of this if we look in our data set we + + align:start position:0% +of this if we look in our data set we + + + align:start position:0% +of this if we look in our data set we +may see an association between a and Y + + align:start position:0% +may see an association between a and Y + + + align:start position:0% +may see an association between a and Y +but that Association is not because + + align:start position:0% +but that Association is not because + + + align:start position:0% +but that Association is not because +there's necessarily an effective a on Y + + align:start position:0% +there's necessarily an effective a on Y + + + align:start position:0% +there's necessarily an effective a on Y +it might not be causal it may be due to + + align:start position:0% +it might not be causal it may be due to + + + align:start position:0% +it might not be causal it may be due to +this selection bias that we created so + + align:start position:0% +this selection bias that we created so + + + align:start position:0% +this selection bias that we created so +this is the problem and so in these + + align:start position:0% +this is the problem and so in these + + + align:start position:0% +this is the problem and so in these +cases we need a special type of method + + align:start position:0% +cases we need a special type of method + + + align:start position:0% +cases we need a special type of method +that can handle these settings and so a + + align:start position:0% +that can handle these settings and so a + + + align:start position:0% +that can handle these settings and so a +class of methods that was designed + + align:start position:0% +class of methods that was designed + + + align:start position:0% +class of methods that was designed +specifically to handle this is G methods + + align:start position:0% +specifically to handle this is G methods + + + align:start position:0% +specifically to handle this is G methods +and so these are sometimes referred to + + align:start position:0% +and so these are sometimes referred to + + + align:start position:0% +and so these are sometimes referred to +as causal methods they've been developed + + align:start position:0% +as causal methods they've been developed + + + align:start position:0% +as causal methods they've been developed +by Jamie Robbins and colleagues and + + align:start position:0% +by Jamie Robbins and colleagues and + + + align:start position:0% +by Jamie Robbins and colleagues and +collaborators since 1986 and they + + align:start position:0% +collaborators since 1986 and they + + + align:start position:0% +collaborators since 1986 and they +include the parametric G formula G + + align:start position:0% +include the parametric G formula G + + + align:start position:0% +include the parametric G formula G +estimation of structural nested models + + align:start position:0% +estimation of structural nested models + + + align:start position:0% +estimation of structural nested models +and inverse probability weighting of + + align:start position:0% +and inverse probability weighting of + + + align:start position:0% +and inverse probability weighting of +marginal structural models + + align:start position:0% + + + + align:start position:0% + +so in my research what I do is I combine + + align:start position:0% +so in my research what I do is I combine + + + align:start position:0% +so in my research what I do is I combine +G methods with large longitudinal + + align:start position:0% +G methods with large longitudinal + + + align:start position:0% +G methods with large longitudinal +databases to try to evaluate dynamic + + align:start position:0% +databases to try to evaluate dynamic + + + align:start position:0% +databases to try to evaluate dynamic +treatment strategies so I'm particularly + + align:start position:0% +treatment strategies so I'm particularly + + + align:start position:0% +treatment strategies so I'm particularly +interested in bringing these methods to + + align:start position:0% +interested in bringing these methods to + + + align:start position:0% +interested in bringing these methods to +cancer research because they haven't + + align:start position:0% +cancer research because they haven't + + + align:start position:0% +cancer research because they haven't +been applied much there so a lot of my + + align:start position:0% +been applied much there so a lot of my + + + align:start position:0% +been applied much there so a lot of my +research questions are focused on + + align:start position:0% +research questions are focused on + + + align:start position:0% +research questions are focused on +answering questions like how and when + + align:start position:0% +answering questions like how and when + + + align:start position:0% +answering questions like how and when +can we intervene to best prevent detect + + align:start position:0% +can we intervene to best prevent detect + + + align:start position:0% +can we intervene to best prevent detect +and treat cancer and so I'd like to + + align:start position:0% +and treat cancer and so I'd like to + + + align:start position:0% +and treat cancer and so I'd like to +share one example with you which focused + + align:start position:0% +share one example with you which focused + + + align:start position:0% +share one example with you which focused +on evaluating the effect of adhering to + + align:start position:0% +on evaluating the effect of adhering to + + + align:start position:0% +on evaluating the effect of adhering to +guideline based physical activity + + align:start position:0% +guideline based physical activity + + + align:start position:0% +guideline based physical activity +interventions on survival among men with + + align:start position:0% +interventions on survival among men with + + + align:start position:0% +interventions on survival among men with +prostate cancer so the motivation for + + align:start position:0% +prostate cancer so the motivation for + + + align:start position:0% +prostate cancer so the motivation for +this study there's a large clinical + + align:start position:0% +this study there's a large clinical + + + align:start position:0% +this study there's a large clinical +organization ASCO the American Society + + align:start position:0% +organization ASCO the American Society + + + align:start position:0% +organization ASCO the American Society +of Clinical Oncology but it actually + + align:start position:0% +of Clinical Oncology but it actually + + + align:start position:0% +of Clinical Oncology but it actually +called for randomized trials to generate + + align:start position:0% +called for randomized trials to generate + + + align:start position:0% +called for randomized trials to generate +these estimates for several cancers + + align:start position:0% +these estimates for several cancers + + + align:start position:0% +these estimates for several cancers +thinking with prostate cancer is it's a + + align:start position:0% +thinking with prostate cancer is it's a + + + align:start position:0% +thinking with prostate cancer is it's a +very slowly progressing disease so the + + align:start position:0% +very slowly progressing disease so the + + + align:start position:0% +very slowly progressing disease so the +feasibility of doing a trial to evaluate + + align:start position:0% +feasibility of doing a trial to evaluate + + + align:start position:0% +feasibility of doing a trial to evaluate +this is very limited the trial would + + align:start position:0% +this is very limited the trial would + + + align:start position:0% +this is very limited the trial would +have to be ten years long probably so + + align:start position:0% +have to be ten years long probably so + + + align:start position:0% +have to be ten years long probably so +given that given the absence of this + + align:start position:0% +given that given the absence of this + + + align:start position:0% +given that given the absence of this +randomized evidence we did the next best + + align:start position:0% +randomized evidence we did the next best + + + align:start position:0% +randomized evidence we did the next best +thing that we could do to generate this + + align:start position:0% +thing that we could do to generate this + + + align:start position:0% +thing that we could do to generate this +estimate which was combine high-quality + + align:start position:0% +estimate which was combine high-quality + + + align:start position:0% +estimate which was combine high-quality +observational data with you know + + align:start position:0% +observational data with you know + + + align:start position:0% +observational data with you know +advanced epi methods in this case the + + align:start position:0% +advanced epi methods in this case the + + + align:start position:0% +advanced epi methods in this case the +parametric G formula and so we leveraged + + align:start position:0% +parametric G formula and so we leveraged + + + align:start position:0% +parametric G formula and so we leveraged +data from the health professionals + + align:start position:0% +data from the health professionals + + + align:start position:0% +data from the health professionals +follow-up study which is a well + + align:start position:0% +follow-up study which is a well + + + align:start position:0% +follow-up study which is a well +characterized prospective cohort study + + align:start position:0% + + + + align:start position:0% + +so in these cases there's a three step + + align:start position:0% +so in these cases there's a three step + + + align:start position:0% +so in these cases there's a three step +process that we take to extract the most + + align:start position:0% +process that we take to extract the most + + + align:start position:0% +process that we take to extract the most +meaningful and actionable insights from + + align:start position:0% +meaningful and actionable insights from + + + align:start position:0% +meaningful and actionable insights from +observational data so the first thing + + align:start position:0% +observational data so the first thing + + + align:start position:0% +observational data so the first thing +that we do is we specify the protocol of + + align:start position:0% +that we do is we specify the protocol of + + + align:start position:0% +that we do is we specify the protocol of +the target trial that we would have + + align:start position:0% +the target trial that we would have + + + align:start position:0% +the target trial that we would have +liked to conduct had it been feasible + + align:start position:0% +liked to conduct had it been feasible + + + align:start position:0% +liked to conduct had it been feasible +the second thing we do is we make sure + + align:start position:0% +the second thing we do is we make sure + + + align:start position:0% +the second thing we do is we make sure +that we measure enough covariance to + + align:start position:0% +that we measure enough covariance to + + + align:start position:0% +that we measure enough covariance to +approximately adjust for confounding and + + align:start position:0% +approximately adjust for confounding and + + + align:start position:0% +approximately adjust for confounding and +achieve conditional exchangeability and + + align:start position:0% +achieve conditional exchangeability and + + + align:start position:0% +achieve conditional exchangeability and +then the third thing we do is we apply + + align:start position:0% +then the third thing we do is we apply + + + align:start position:0% +then the third thing we do is we apply +an appropriate method to compare the + + align:start position:0% +an appropriate method to compare the + + + align:start position:0% +an appropriate method to compare the +specified treatment strategies under + + align:start position:0% +specified treatment strategies under + + + align:start position:0% +specified treatment strategies under +this assumption + + align:start position:0% +this assumption + + + align:start position:0% +this assumption +conditional exchangeability and so in + + align:start position:0% +conditional exchangeability and so in + + + align:start position:0% +conditional exchangeability and so in +this case eligible men for this study + + align:start position:0% +this case eligible men for this study + + + align:start position:0% +this case eligible men for this study +had been diagnosed with non metastatic + + align:start position:0% +had been diagnosed with non metastatic + + + align:start position:0% +had been diagnosed with non metastatic +prostate cancer and a baseline they were + + align:start position:0% +prostate cancer and a baseline they were + + + align:start position:0% +prostate cancer and a baseline they were +free of cardiovascular and neurologic + + align:start position:0% +free of cardiovascular and neurologic + + + align:start position:0% +free of cardiovascular and neurologic +conditions that may limit physical + + align:start position:0% +conditions that may limit physical + + + align:start position:0% +conditions that may limit physical +ability for the treatment strategies men + + align:start position:0% +ability for the treatment strategies men + + + align:start position:0% +ability for the treatment strategies men +were to initiate one of six physical + + align:start position:0% +were to initiate one of six physical + + + align:start position:0% +were to initiate one of six physical +activity strategies at diagnosis and + + align:start position:0% +activity strategies at diagnosis and + + + align:start position:0% +activity strategies at diagnosis and +continue it over follow-up until the + + align:start position:0% +continue it over follow-up until the + + + align:start position:0% +continue it over follow-up until the +development of a condition limiting + + align:start position:0% +development of a condition limiting + + + align:start position:0% +development of a condition limiting +physical activity so this is what made + + align:start position:0% +physical activity so this is what made + + + align:start position:0% +physical activity so this is what made +the strategies dynamic the intervention + + align:start position:0% +the strategies dynamic the intervention + + + align:start position:0% +the strategies dynamic the intervention +over time depended on these evolving + + align:start position:0% +over time depended on these evolving + + + align:start position:0% +over time depended on these evolving +conditions and so just to note we pre + + align:start position:0% +conditions and so just to note we pre + + + align:start position:0% +conditions and so just to note we pre +specified these strategies that we were + + align:start position:0% +specified these strategies that we were + + + align:start position:0% +specified these strategies that we were +evaluating as well as the conditions men + + align:start position:0% +evaluating as well as the conditions men + + + align:start position:0% +evaluating as well as the conditions men +were followed until diagnosis until + + align:start position:0% +were followed until diagnosis until + + + align:start position:0% +were followed until diagnosis until +death and to follow-up ten years after + + align:start position:0% +death and to follow-up ten years after + + + align:start position:0% +death and to follow-up ten years after +diagnosis or administrative end to + + align:start position:0% +diagnosis or administrative end to + + + align:start position:0% +diagnosis or administrative end to +follow-up which ever happened first our + + align:start position:0% +follow-up which ever happened first our + + + align:start position:0% +follow-up which ever happened first our +outcome of interest was all cause + + align:start position:0% +outcome of interest was all cause + + + align:start position:0% +outcome of interest was all cause +mortality within ten years and we were + + align:start position:0% +mortality within ten years and we were + + + align:start position:0% +mortality within ten years and we were +interested in estimating the per + + align:start position:0% +interested in estimating the per + + + align:start position:0% +interested in estimating the per +protocol effect of not just initiating + + align:start position:0% +protocol effect of not just initiating + + + align:start position:0% +protocol effect of not just initiating +these strategies but adhering to them + + align:start position:0% +these strategies but adhering to them + + + align:start position:0% +these strategies but adhering to them +over follow-up and again we applied the + + align:start position:0% +over follow-up and again we applied the + + + align:start position:0% +over follow-up and again we applied the +parametric G formula so I think you've + + align:start position:0% +parametric G formula so I think you've + + + align:start position:0% +parametric G formula so I think you've +already heard about the G formula in a + + align:start position:0% +already heard about the G formula in a + + + align:start position:0% +already heard about the G formula in a +previous lecture possibly in a slightly + + align:start position:0% +previous lecture possibly in a slightly + + + align:start position:0% +previous lecture possibly in a slightly +different way so I'll I won't spend too + + align:start position:0% +different way so I'll I won't spend too + + + align:start position:0% +different way so I'll I won't spend too +much time on this so the G formula + + align:start position:0% +much time on this so the G formula + + + align:start position:0% +much time on this so the G formula +essentially the way I think about it is + + align:start position:0% +essentially the way I think about it is + + + align:start position:0% +essentially the way I think about it is +a generalization of standardization to + + align:start position:0% +a generalization of standardization to + + + align:start position:0% +a generalization of standardization to +time varying exposures and confounders + + align:start position:0% +time varying exposures and confounders + + + align:start position:0% +time varying exposures and confounders +so it's basically a weighted average of + + align:start position:0% +so it's basically a weighted average of + + + align:start position:0% +so it's basically a weighted average of +risks where you can think of the weights + + align:start position:0% +risks where you can think of the weights + + + align:start position:0% +risks where you can think of the weights +being the probability density functions + + align:start position:0% +being the probability density functions + + + align:start position:0% +being the probability density functions +of the time varying confounders which we + + align:start position:0% +of the time varying confounders which we + + + align:start position:0% +of the time varying confounders which we +estimate using parametric regression + + align:start position:0% +estimate using parametric regression + + + align:start position:0% +estimate using parametric regression +models and we approximate the weighted + + align:start position:0% +models and we approximate the weighted + + + align:start position:0% +models and we approximate the weighted +average using Monte Carlo simulation so + + align:start position:0% +average using Monte Carlo simulation so + + + align:start position:0% +average using Monte Carlo simulation so +practically how do we do this so the + + align:start position:0% +practically how do we do this so the + + + align:start position:0% +practically how do we do this so the +first thing we do is we fit parametric + + align:start position:0% +first thing we do is we fit parametric + + + align:start position:0% +first thing we do is we fit parametric +regression models for all of the + + align:start position:0% +regression models for all of the + + + align:start position:0% +regression models for all of the +variables that we're going to be + + align:start position:0% +variables that we're going to be + + + align:start position:0% +variables that we're going to be +studying so for treatment confounders + + align:start position:0% +studying so for treatment confounders + + + align:start position:0% +studying so for treatment confounders +and death at each follow-up time the + + align:start position:0% +and death at each follow-up time the + + + align:start position:0% +and death at each follow-up time the +next thing we do is Monte Carlo + + align:start position:0% +next thing we do is Monte Carlo + + + align:start position:0% +next thing we do is Monte Carlo +simulation where essentially what we + + align:start position:0% +simulation where essentially what we + + + align:start position:0% +simulation where essentially what we +want to do is simulate the outcome + + align:start position:0% +want to do is simulate the outcome + + + align:start position:0% +want to do is simulate the outcome +distribution under each treatment + + align:start position:0% +distribution under each treatment + + + align:start position:0% +distribution under each treatment +strategy that we're interested in + + align:start position:0% +strategy that we're interested in + + + align:start position:0% +strategy that we're interested in +and then we bootstrap the confidence + + align:start position:0% +and then we bootstrap the confidence + + + align:start position:0% +and then we bootstrap the confidence +intervals so I'd like to show you kind + + align:start position:0% +intervals so I'd like to show you kind + + + align:start position:0% +intervals so I'd like to show you kind +of in a schematic what this looks like + + align:start position:0% +of in a schematic what this looks like + + + align:start position:0% +of in a schematic what this looks like +because it might be a little bit easier + + align:start position:0% +because it might be a little bit easier + + + align:start position:0% +because it might be a little bit easier +to see so again the idea is we're gonna + + align:start position:0% +to see so again the idea is we're gonna + + + align:start position:0% +to see so again the idea is we're gonna +make copies of our data set where in + + align:start position:0% +make copies of our data set where in + + + align:start position:0% +make copies of our data set where in +each copy everyone is adhering to the + + align:start position:0% +each copy everyone is adhering to the + + + align:start position:0% +each copy everyone is adhering to the +strategy that we're focusing on in that + + align:start position:0% +strategy that we're focusing on in that + + + align:start position:0% +strategy that we're focusing on in that +copy so how do we construct each of + + align:start position:0% +copy so how do we construct each of + + + align:start position:0% +copy so how do we construct each of +these copies of the data set we have to + + align:start position:0% +these copies of the data set we have to + + + align:start position:0% +these copies of the data set we have to +build them each from the ground up + + align:start position:0% +build them each from the ground up + + + align:start position:0% +build them each from the ground up +starting with time zero so the values of + + align:start position:0% +starting with time zero so the values of + + + align:start position:0% +starting with time zero so the values of +all of the time varying covariates at + + align:start position:0% +all of the time varying covariates at + + + align:start position:0% +all of the time varying covariates at +time zero are sampled from their + + align:start position:0% +time zero are sampled from their + + + align:start position:0% +time zero are sampled from their +empirical distribution so these are + + align:start position:0% +empirical distribution so these are + + + align:start position:0% +empirical distribution so these are +actually observed values of the + + align:start position:0% +actually observed values of the + + + align:start position:0% +actually observed values of the +covariance how do we get the values at + + align:start position:0% +covariance how do we get the values at + + + align:start position:0% +covariance how do we get the values at +the next time point we use the + + align:start position:0% +the next time point we use the + + + align:start position:0% +the next time point we use the +parametric regression models that I + + align:start position:0% +parametric regression models that I + + + align:start position:0% +parametric regression models that I +mentioned that we fit in step one then + + align:start position:0% +mentioned that we fit in step one then + + + align:start position:0% +mentioned that we fit in step one then +what we do is we force the level of the + + align:start position:0% +what we do is we force the level of the + + + align:start position:0% +what we do is we force the level of the +intervention variable to be whatever was + + align:start position:0% +intervention variable to be whatever was + + + align:start position:0% +intervention variable to be whatever was +specified by that intervention strategy + + align:start position:0% +specified by that intervention strategy + + + align:start position:0% +specified by that intervention strategy +and then we estimate the risk of the + + align:start position:0% +and then we estimate the risk of the + + + align:start position:0% +and then we estimate the risk of the +outcome at each time period given these + + align:start position:0% +outcome at each time period given these + + + align:start position:0% +outcome at each time period given these +variables again using the parametric + + align:start position:0% +variables again using the parametric + + + align:start position:0% +variables again using the parametric +regression model for the outcome now and + + align:start position:0% +regression model for the outcome now and + + + align:start position:0% +regression model for the outcome now and +so we repeat this over all time periods + + align:start position:0% +so we repeat this over all time periods + + + align:start position:0% +so we repeat this over all time periods +to estimate a cumulative risk under that + + align:start position:0% +to estimate a cumulative risk under that + + + align:start position:0% +to estimate a cumulative risk under that +strategy which is taken as the average + + align:start position:0% +strategy which is taken as the average + + + align:start position:0% +strategy which is taken as the average +of the subject specific risks so this is + + align:start position:0% +of the subject specific risks so this is + + + align:start position:0% +of the subject specific risks so this is +what I'm doing this is kind of under the + + align:start position:0% +what I'm doing this is kind of under the + + + align:start position:0% +what I'm doing this is kind of under the +hood what's going on with this with this + + align:start position:0% +hood what's going on with this with this + + + align:start position:0% +hood what's going on with this with this +method so you first estimate the Markov + + align:start position:0% +method so you first estimate the Markov + + + align:start position:0% +method so you first estimate the Markov +decision process mm-hmm which allows you + + align:start position:0% +decision process mm-hmm which allows you + + + align:start position:0% +decision process mm-hmm which allows you +in essence to simulate from the + + align:start position:0% +in essence to simulate from the + + + align:start position:0% +in essence to simulate from the +underlying data distribution so you know + + align:start position:0% +underlying data distribution so you know + + + align:start position:0% +underlying data distribution so you know +that probability of the sort of next + + align:start position:0% +that probability of the sort of next + + + align:start position:0% +that probability of the sort of next +sequence of observations given the + + align:start position:0% +sequence of observations given the + + + align:start position:0% +sequence of observations given the +previous sequence and action and + + align:start position:0% +previous sequence and action and + + + align:start position:0% +previous sequence and action and +previous actions and then with that then + + align:start position:0% +previous actions and then with that then + + + align:start position:0% +previous actions and then with that then +you could sort of you could you could + + align:start position:0% +you could sort of you could you could + + + align:start position:0% +you could sort of you could you could +then intervene and simulate for so that + + align:start position:0% +then intervene and simulate for so that + + + align:start position:0% +then intervene and simulate for so that +was if you remember graduate gave you + + align:start position:0% +was if you remember graduate gave you + + + align:start position:0% +was if you remember graduate gave you +three different buckets of approaches + + align:start position:0% +three different buckets of approaches + + + align:start position:0% +three different buckets of approaches +and then he focused on the middle one + + align:start position:0% +and then he focused on the middle one + + + align:start position:0% +and then he focused on the middle one +this is the leftmost problem + + align:start position:0% +this is the leftmost problem + + + align:start position:0% +this is the leftmost problem +I have that right so we didn't talk + + align:start position:0% +I have that right so we didn't talk + + + align:start position:0% +I have that right so we didn't talk +about yes but it's very sensible what + + align:start position:0% +about yes but it's very sensible what + + + align:start position:0% +about yes but it's very sensible what +side oh it seems very hard yeah so that + + align:start position:0% +side oh it seems very hard yeah so that + + + align:start position:0% +side oh it seems very hard yeah so that +is a challenge that is the hardest part + + align:start position:0% +is a challenge that is the hardest part + + + align:start position:0% +is a challenge that is the hardest part +about this mm-hm and it's relying on a + + align:start position:0% +about this mm-hm and it's relying on a + + + align:start position:0% +about this mm-hm and it's relying on a +lot of assumptions yeah so the primary + + align:start position:0% +lot of assumptions yeah so the primary + + + align:start position:0% +lot of assumptions yeah so the primary +results that kind of come out after we + + align:start position:0% +results that kind of come out after we + + + align:start position:0% +results that kind of come out after we +do all of this so this is the estimated + + align:start position:0% +do all of this so this is the estimated + + + align:start position:0% +do all of this so this is the estimated +risk of all-cause mortality under + + align:start position:0% +risk of all-cause mortality under + + + align:start position:0% +risk of all-cause mortality under +several physical activity interventions + + align:start position:0% +several physical activity interventions + + + align:start position:0% +several physical activity interventions +so I'm not gonna focus too much on the + + align:start position:0% +so I'm not gonna focus too much on the + + + align:start position:0% +so I'm not gonna focus too much on the +results I want to focus on two main kind + + align:start position:0% +results I want to focus on two main kind + + + align:start position:0% +results I want to focus on two main kind +of takeaways from this slide one thing + + align:start position:0% +of takeaways from this slide one thing + + + align:start position:0% +of takeaways from this slide one thing +to emphasize is we pre specified the + + align:start position:0% +to emphasize is we pre specified the + + + align:start position:0% +to emphasize is we pre specified the +weekly duration of physical activity or + + align:start position:0% +weekly duration of physical activity or + + + align:start position:0% +weekly duration of physical activity or +you can think of this like the dose of + + align:start position:0% +you can think of this like the dose of + + + align:start position:0% +you can think of this like the dose of +the intervention we pre specified that + + align:start position:0% +the intervention we pre specified that + + + align:start position:0% +the intervention we pre specified that +and this was based on current guidelines + + align:start position:0% +and this was based on current guidelines + + + align:start position:0% +and this was based on current guidelines +so the third row of each band we did + + align:start position:0% +so the third row of each band we did + + + align:start position:0% +so the third row of each band we did +look at some dose or level beyond the + + align:start position:0% +look at some dose or level beyond the + + + align:start position:0% +look at some dose or level beyond the +guidelines to see if there might be + + align:start position:0% +guidelines to see if there might be + + + align:start position:0% +guidelines to see if there might be +additional survival benefits but these + + align:start position:0% +additional survival benefits but these + + + align:start position:0% +additional survival benefits but these +were all pre specified we also pre + + align:start position:0% +were all pre specified we also pre + + + align:start position:0% +were all pre specified we also pre +specified all of the time varying + + align:start position:0% +specified all of the time varying + + + align:start position:0% +specified all of the time varying +covariates that made these strategies + + align:start position:0% +covariates that made these strategies + + + align:start position:0% +covariates that made these strategies +dynamic so I mentioned that men were + + align:start position:0% +dynamic so I mentioned that men were + + + align:start position:0% +dynamic so I mentioned that men were +excused from following the recommended + + align:start position:0% +excused from following the recommended + + + align:start position:0% +excused from following the recommended +physical activity levels if they + + align:start position:0% +physical activity levels if they + + + align:start position:0% +physical activity levels if they +developed one of these listed conditions + + align:start position:0% +developed one of these listed conditions + + + align:start position:0% +developed one of these listed conditions +metastasis and my stroke etc we pre + + align:start position:0% +metastasis and my stroke etc we pre + + + align:start position:0% +metastasis and my stroke etc we pre +specified all of those it's possible + + align:start position:0% +specified all of those it's possible + + + align:start position:0% +specified all of those it's possible +that maybe you know a different + + align:start position:0% +that maybe you know a different + + + align:start position:0% +that maybe you know a different +dependence on a different time varying + + align:start position:0% +dependence on a different time varying + + + align:start position:0% +dependence on a different time varying +ovarian may have led to a more optimal + + align:start position:0% +ovarian may have led to a more optimal + + + align:start position:0% +ovarian may have led to a more optimal +strategy there was a lot that remained + + align:start position:0% +strategy there was a lot that remained + + + align:start position:0% +strategy there was a lot that remained +unexplored so we did a lot of + + align:start position:0% +unexplored so we did a lot of + + + align:start position:0% +unexplored so we did a lot of +sensitivity analyses as part of this + + align:start position:0% +sensitivity analyses as part of this + + + align:start position:0% +sensitivity analyses as part of this +project I'd like to focus though on the + + align:start position:0% +project I'd like to focus though on the + + + align:start position:0% +project I'd like to focus though on the +sensitivity analyses that we did for + + align:start position:0% +sensitivity analyses that we did for + + + align:start position:0% +sensitivity analyses that we did for +potential unmeasured confounding by + + align:start position:0% +potential unmeasured confounding by + + + align:start position:0% +potential unmeasured confounding by +chronic disease that may be severe + + align:start position:0% +chronic disease that may be severe + + + align:start position:0% +chronic disease that may be severe +enough to affect both physical activity + + align:start position:0% +enough to affect both physical activity + + + align:start position:0% +enough to affect both physical activity +and survival and so the G formula is + + align:start position:0% +and survival and so the G formula is + + + align:start position:0% +and survival and so the G formula is +actually providing a natural way to at + + align:start position:0% +actually providing a natural way to at + + + align:start position:0% +actually providing a natural way to at +least partly address this by estimating + + align:start position:0% +least partly address this by estimating + + + align:start position:0% +least partly address this by estimating +the risk of these physical activity + + align:start position:0% +the risk of these physical activity + + + align:start position:0% +the risk of these physical activity +interventions + + align:start position:0% +interventions + + + align:start position:0% +interventions +that are at each time point t only + + align:start position:0% +that are at each time point t only + + + align:start position:0% +that are at each time point t only +applied to men who are healthy enough to + + align:start position:0% +applied to men who are healthy enough to + + + align:start position:0% +applied to men who are healthy enough to +maintain the physical activity level at + + align:start position:0% +maintain the physical activity level at + + + align:start position:0% +maintain the physical activity level at +that time and so again in the main + + align:start position:0% +that time and so again in the main + + + align:start position:0% +that time and so again in the main +analysis we excused men from following + + align:start position:0% +analysis we excused men from following + + + align:start position:0% +analysis we excused men from following +the recommended levels if they developed + + align:start position:0% +the recommended levels if they developed + + + align:start position:0% +the recommended levels if they developed +one of these serious conditions so in + + align:start position:0% +one of these serious conditions so in + + + align:start position:0% +one of these serious conditions so in +sensitivity analyses we then expanded + + align:start position:0% +sensitivity analyses we then expanded + + + align:start position:0% +sensitivity analyses we then expanded +this list of serious conditions to also + + align:start position:0% +this list of serious conditions to also + + + align:start position:0% +this list of serious conditions to also +include the conditions that are shown in + + align:start position:0% +include the conditions that are shown in + + + align:start position:0% +include the conditions that are shown in +blue text and so this attenuated our + + align:start position:0% +blue text and so this attenuated our + + + align:start position:0% +blue text and so this attenuated our +estimates but didn't change our + + align:start position:0% +estimates but didn't change our + + + align:start position:0% +estimates but didn't change our +conclusions one thing to point out is + + align:start position:0% +conclusions one thing to point out is + + + align:start position:0% +conclusions one thing to point out is +that the validity of this approach rests + + align:start position:0% +that the validity of this approach rests + + + align:start position:0% +that the validity of this approach rests +on the assumption that at each time T we + + align:start position:0% +on the assumption that at each time T we + + + align:start position:0% +on the assumption that at each time T we +had available data needed to identify + + align:start position:0% +had available data needed to identify + + + align:start position:0% +had available data needed to identify +which men were healthy at that time + + align:start position:0% +which men were healthy at that time + + + align:start position:0% +which men were healthy at that time +enough to do the physical activity yeah + + align:start position:0% + + + + align:start position:0% + +great question + + align:start position:0% +great question + + + align:start position:0% +great question +so because the strategy was pre + + align:start position:0% +so because the strategy was pre + + + align:start position:0% +so because the strategy was pre +specified to say that if you develop one + + align:start position:0% +specified to say that if you develop one + + + align:start position:0% +specified to say that if you develop one +of these conditions you may essentially + + align:start position:0% +of these conditions you may essentially + + + align:start position:0% +of these conditions you may essentially +do whatever level of physical activity + + align:start position:0% +do whatever level of physical activity + + + align:start position:0% +do whatever level of physical activity +you're able to do so importantly I'm + + align:start position:0% +you're able to do so importantly I'm + + + align:start position:0% +you're able to do so importantly I'm +glad you brought this up we did not + + align:start position:0% +glad you brought this up we did not + + + align:start position:0% +glad you brought this up we did not +censor men at that time they were still + + align:start position:0% +censor men at that time they were still + + + align:start position:0% +censor men at that time they were still +followed because they were still + + align:start position:0% +followed because they were still + + + align:start position:0% +followed because they were still +adhering to the strategy as defined + + align:start position:0% +adhering to the strategy as defined + + + align:start position:0% +adhering to the strategy as defined +mm-hm + + align:start position:0% +mm-hm + + + align:start position:0% +mm-hm +thanks for asking and so given that we + + align:start position:0% +thanks for asking and so given that we + + + align:start position:0% +thanks for asking and so given that we +don't know whether the data contain at + + align:start position:0% +don't know whether the data contain at + + + align:start position:0% +don't know whether the data contain at +each time T the information necessary to + + align:start position:0% +each time T the information necessary to + + + align:start position:0% +each time T the information necessary to +know are these men healthy enough at + + align:start position:0% +know are these men healthy enough at + + + align:start position:0% +know are these men healthy enough at +that time we therefore conducted a few + + align:start position:0% +that time we therefore conducted a few + + + align:start position:0% +that time we therefore conducted a few +alternate analyses in which we lagged + + align:start position:0% +alternate analyses in which we lagged + + + align:start position:0% +alternate analyses in which we lagged +physical activity and covariate data by + + align:start position:0% +physical activity and covariate data by + + + align:start position:0% +physical activity and covariate data by +two years and we also used a negative + + align:start position:0% +two years and we also used a negative + + + align:start position:0% +two years and we also used a negative +outcome control to explore potential + + align:start position:0% +outcome control to explore potential + + + align:start position:0% +outcome control to explore potential +unmeasured confounding by clinical + + align:start position:0% +unmeasured confounding by clinical + + + align:start position:0% +unmeasured confounding by clinical +disease or disease severity so what's + + align:start position:0% +disease or disease severity so what's + + + align:start position:0% +disease or disease severity so what's +the rationale behind this so in the DAGs + + align:start position:0% +the rationale behind this so in the DAGs + + + align:start position:0% +the rationale behind this so in the DAGs +below for the original analysis we have + + align:start position:0% +below for the original analysis we have + + + align:start position:0% +below for the original analysis we have +physical activity a we have survival Y + + align:start position:0% +physical activity a we have survival Y + + + align:start position:0% +physical activity a we have survival Y +and this may be confounded by disease + + align:start position:0% +and this may be confounded by disease + + + align:start position:0% +and this may be confounded by disease +severity you so when we see an + + align:start position:0% +severity you so when we see an + + + align:start position:0% +severity you so when we see an +association between a and Y in our data + + align:start position:0% +association between a and Y in our data + + + align:start position:0% +association between a and Y in our data +we want to make sure that it's causal + + align:start position:0% +we want to make sure that it's causal + + + align:start position:0% +we want to make sure that it's causal +that is because of the blue arrow and + + align:start position:0% +that is because of the blue arrow and + + + align:start position:0% +that is because of the blue arrow and +not because of this confounding bias the + + align:start position:0% +not because of this confounding bias the + + + align:start position:0% +not because of this confounding bias the +red arrow so how can we + + align:start position:0% +red arrow so how can we + + + align:start position:0% +red arrow so how can we +potentially provide evidence for whether + + align:start position:0% +potentially provide evidence for whether + + + align:start position:0% +potentially provide evidence for whether +that red pathway is there we selected + + align:start position:0% +that red pathway is there we selected + + + align:start position:0% +that red pathway is there we selected +questionnaire non-response as an + + align:start position:0% +questionnaire non-response as an + + + align:start position:0% +questionnaire non-response as an +alternate outcome instead of survival + + align:start position:0% +alternate outcome instead of survival + + + align:start position:0% +alternate outcome instead of survival +that we assumed was not directly + + align:start position:0% +that we assumed was not directly + + + align:start position:0% +that we assumed was not directly +affected by physical activity but that + + align:start position:0% +affected by physical activity but that + + + align:start position:0% +affected by physical activity but that +we thought would be similarly confounded + + align:start position:0% +we thought would be similarly confounded + + + align:start position:0% +we thought would be similarly confounded +by disease severity and so when we + + align:start position:0% +by disease severity and so when we + + + align:start position:0% +by disease severity and so when we +repeated the analysis with a negative + + align:start position:0% +repeated the analysis with a negative + + + align:start position:0% +repeated the analysis with a negative +outcome control + + align:start position:0% +outcome control + + + align:start position:0% +outcome control +we found that physical activity had a + + align:start position:0% +we found that physical activity had a + + + align:start position:0% +we found that physical activity had a +nearly null effect on questionnaire + + align:start position:0% +nearly null effect on questionnaire + + + align:start position:0% +nearly null effect on questionnaire +non-response as we would expect which + + align:start position:0% +non-response as we would expect which + + + align:start position:0% +non-response as we would expect which +provide some support that in our + + align:start position:0% +provide some support that in our + + + align:start position:0% +provide some support that in our +original analysis physical activity the + + align:start position:0% +original analysis physical activity the + + + align:start position:0% +original analysis physical activity the +effect of physical activity on death was + + align:start position:0% +effect of physical activity on death was + + + align:start position:0% +effect of physical activity on death was +not confounded through the pathways + + align:start position:0% +not confounded through the pathways + + + align:start position:0% +not confounded through the pathways +explored through the negative control so + + align:start position:0% +explored through the negative control so + + + align:start position:0% +explored through the negative control so +one thing to highlight here is the + + align:start position:0% +one thing to highlight here is the + + + align:start position:0% +one thing to highlight here is the +sensitivity analyses were driven by our + + align:start position:0% +sensitivity analyses were driven by our + + + align:start position:0% +sensitivity analyses were driven by our +subject matter knowledge and there's + + align:start position:0% +subject matter knowledge and there's + + + align:start position:0% +subject matter knowledge and there's +nothing in the data that kind of drove + + align:start position:0% +nothing in the data that kind of drove + + + align:start position:0% +nothing in the data that kind of drove +this and so just to recap this portion + + align:start position:0% +this and so just to recap this portion + + + align:start position:0% +this and so just to recap this portion +shoji methods are useful tool because + + align:start position:0% +shoji methods are useful tool because + + + align:start position:0% +shoji methods are useful tool because +they let us validly estimate the effect + + align:start position:0% +they let us validly estimate the effect + + + align:start position:0% +they let us validly estimate the effect +of pre-specified dynamic strategies an + + align:start position:0% +of pre-specified dynamic strategies an + + + align:start position:0% +of pre-specified dynamic strategies an +estimate adjusted absolute risks which + + align:start position:0% +estimate adjusted absolute risks which + + + align:start position:0% +estimate adjusted absolute risks which +are clinically meaningful to us and + + align:start position:0% +are clinically meaningful to us and + + + align:start position:0% +are clinically meaningful to us and +appropriately adjusted survival curves + + align:start position:0% +appropriately adjusted survival curves + + + align:start position:0% +appropriately adjusted survival curves +even in the presence of treatment + + align:start position:0% +even in the presence of treatment + + + align:start position:0% +even in the presence of treatment +confounder feedback which occurs often + + align:start position:0% +confounder feedback which occurs often + + + align:start position:0% +confounder feedback which occurs often +in clinical questions and of course this + + align:start position:0% +in clinical questions and of course this + + + align:start position:0% +in clinical questions and of course this +is under our typical identifiability + + align:start position:0% +is under our typical identifiability + + + align:start position:0% +is under our typical identifiability +assumptions so this makes it a powerful + + align:start position:0% +assumptions so this makes it a powerful + + + align:start position:0% +assumptions so this makes it a powerful +approach to estimate the effects of + + align:start position:0% +approach to estimate the effects of + + + align:start position:0% +approach to estimate the effects of +currently recommended or proposed + + align:start position:0% +currently recommended or proposed + + + align:start position:0% +currently recommended or proposed +strategies that therefore we can specify + + align:start position:0% +strategies that therefore we can specify + + + align:start position:0% +strategies that therefore we can specify +and write out precisely as we did here + + align:start position:0% +and write out precisely as we did here + + + align:start position:0% +and write out precisely as we did here +however these pre specified strategies + + align:start position:0% +however these pre specified strategies + + + align:start position:0% +however these pre specified strategies +may not be the optimal strategies so + + align:start position:0% +may not be the optimal strategies so + + + align:start position:0% +may not be the optimal strategies so +again when I was doing this analysis I + + align:start position:0% +again when I was doing this analysis I + + + align:start position:0% +again when I was doing this analysis I +was thinking there's so many different + + align:start position:0% +was thinking there's so many different + + + align:start position:0% +was thinking there's so many different +weekly durations of physical activity + + align:start position:0% +weekly durations of physical activity + + + align:start position:0% +weekly durations of physical activity +that we're not looking at there's so + + align:start position:0% +that we're not looking at there's so + + + align:start position:0% +that we're not looking at there's so +many different time varying covariates + + align:start position:0% +many different time varying covariates + + + align:start position:0% +many different time varying covariates +where we could have different + + align:start position:0% +where we could have different + + + align:start position:0% +where we could have different +dependencies on those for these + + align:start position:0% +dependencies on those for these + + + align:start position:0% +dependencies on those for these +strategies over the time and maybe those + + align:start position:0% +strategies over the time and maybe those + + + align:start position:0% +strategies over the time and maybe those +would have led to better survival + + align:start position:0% +would have led to better survival + + + align:start position:0% +would have led to better survival +outcomes among these men but all of that + + align:start position:0% +outcomes among these men but all of that + + + align:start position:0% +outcomes among these men but all of that +was unexplored \ No newline at end of file diff --git a/zlmokDj0DaU.txt b/zlmokDj0DaU.txt new file mode 100644 index 0000000000000000000000000000000000000000..945df5bc9f6dc1aa838149b3fc27f1c88acf9be1 --- /dev/null +++ b/zlmokDj0DaU.txt @@ -0,0 +1,16355 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT OpenCourseWare continue to + + align:start position:0% +will help MIT OpenCourseWare continue to + + + align:start position:0% +will help MIT OpenCourseWare continue to +offer high quality educational resources + + align:start position:0% +offer high quality educational resources + + + align:start position:0% +offer high quality educational resources +for free to make a donation or view + + align:start position:0% +for free to make a donation or view + + + align:start position:0% +for free to make a donation or view +additional materials from hundreds of + + align:start position:0% +additional materials from hundreds of + + + align:start position:0% +additional materials from hundreds of +MIT courses visit MIT opencourseware at + + align:start position:0% +MIT courses visit MIT opencourseware at + + + align:start position:0% +MIT courses visit MIT opencourseware at +ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +so today I promised I would play through + + align:start position:0% +so today I promised I would play through + + + align:start position:0% +so today I promised I would play through +the second half of the tournament that I + + align:start position:0% +the second half of the tournament that I + + + align:start position:0% +the second half of the tournament that I +started last time so two times ago but + + align:start position:0% +started last time so two times ago but + + + align:start position:0% +started last time so two times ago but +before Jennifer Shahi days guest lecture + + align:start position:0% +before Jennifer Shahi days guest lecture + + + align:start position:0% +before Jennifer Shahi days guest lecture +but before I start so so remember last + + align:start position:0% +but before I start so so remember last + + + align:start position:0% +but before I start so so remember last +time we got to the final table this is + + align:start position:0% +time we got to the final table this is + + + align:start position:0% +time we got to the final table this is +essentially the start of the final table + + align:start position:0% +essentially the start of the final table + + + align:start position:0% +essentially the start of the final table +and but before I get into the hands I + + align:start position:0% +and but before I get into the hands I + + + align:start position:0% +and but before I get into the hands I +want to do a bit of Theory first that + + align:start position:0% +want to do a bit of Theory first that + + + align:start position:0% +want to do a bit of Theory first that +I've sort of been for going so far in + + align:start position:0% +I've sort of been for going so far in + + + align:start position:0% +I've sort of been for going so far in +this class and it's essentially is what + + align:start position:0% +this class and it's essentially is what + + + align:start position:0% +this class and it's essentially is what +what's called the independent chip model + + align:start position:0% +what's called the independent chip model + + + align:start position:0% +what's called the independent chip model +or ICM theory and essentially what it's + + align:start position:0% +or ICM theory and essentially what it's + + + align:start position:0% +or ICM theory and essentially what it's +used for is in + + align:start position:0% +used for is in + + + align:start position:0% +used for is in +tournaments essentially the the value of + + align:start position:0% +tournaments essentially the the value of + + + align:start position:0% +tournaments essentially the the value of +chips is essentially nonlinear because + + align:start position:0% +chips is essentially nonlinear because + + + align:start position:0% +chips is essentially nonlinear because +you're not really trying to just get out + + align:start position:0% +you're not really trying to just get out + + + align:start position:0% +you're not really trying to just get out +the chips you're trying to last as long + + align:start position:0% +the chips you're trying to last as long + + + align:start position:0% +the chips you're trying to last as long +as possible and move up the pants so I + + align:start position:0% +as possible and move up the pants so I + + + align:start position:0% +as possible and move up the pants so I +want to sort of now formally quantify + + align:start position:0% +want to sort of now formally quantify + + + align:start position:0% +want to sort of now formally quantify +what this means and how we calculate the + + align:start position:0% +what this means and how we calculate the + + + align:start position:0% +what this means and how we calculate the +DV of your Gamble's so + + align:start position:0% +DV of your Gamble's so + + + align:start position:0% +DV of your Gamble's so +far I think I've just told you you know + + align:start position:0% +far I think I've just told you you know + + + align:start position:0% +far I think I've just told you you know +everything I've done so far in this + + align:start position:0% +everything I've done so far in this + + + align:start position:0% +everything I've done so far in this +class has been shifty B and that told + + align:start position:0% +class has been shifty B and that told + + + align:start position:0% +class has been shifty B and that told +you you know just play you maximize chip + + align:start position:0% +you you know just play you maximize chip + + + align:start position:0% +you you know just play you maximize chip +evey maximize your expected number of + + align:start position:0% +evey maximize your expected number of + + + align:start position:0% +evey maximize your expected number of +chips and that's a pretty reasonable way + + align:start position:0% +chips and that's a pretty reasonable way + + + align:start position:0% +chips and that's a pretty reasonable way +to play and cash games is what you want + + align:start position:0% +to play and cash games is what you want + + + align:start position:0% +to play and cash games is what you want +to do and in tournaments it's it's not a + + align:start position:0% +to do and in tournaments it's it's not a + + + align:start position:0% +to do and in tournaments it's it's not a +bad approximation so I don't want + + align:start position:0% +bad approximation so I don't want + + + align:start position:0% +bad approximation so I don't want +everyone after this I see I'm not sure + + align:start position:0% +everyone after this I see I'm not sure + + + align:start position:0% +everyone after this I see I'm not sure +do you think you know I got a completely + + align:start position:0% +do you think you know I got a completely + + + align:start position:0% +do you think you know I got a completely +change by playing in tournaments because + + align:start position:0% +change by playing in tournaments because + + + align:start position:0% +change by playing in tournaments because +that's not the case essentially playing + + align:start position:0% +that's not the case essentially playing + + + align:start position:0% +that's not the case essentially playing +you're maximized expected number of + + align:start position:0% +you're maximized expected number of + + + align:start position:0% +you're maximized expected number of +chips is a pretty good approximation of + + align:start position:0% +chips is a pretty good approximation of + + + align:start position:0% +chips is a pretty good approximation of +how you actually should be playing but + + align:start position:0% +how you actually should be playing but + + + align:start position:0% +how you actually should be playing but +there are some small differences and + + align:start position:0% +there are some small differences and + + + align:start position:0% +there are some small differences and +extreme situations and I'd like to + + align:start position:0% +extreme situations and I'd like to + + + align:start position:0% +extreme situations and I'd like to +highlight some of that today so okay + + align:start position:0% +highlight some of that today so okay + + + align:start position:0% +highlight some of that today so okay +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +so this is essentially yes so it's this + + align:start position:0% +so this is essentially yes so it's this + + + align:start position:0% +so this is essentially yes so it's this +idea of minimizing risks you stay alive + + align:start position:0% +idea of minimizing risks you stay alive + + + align:start position:0% +idea of minimizing risks you stay alive +and move up to escalating payouts so I + + align:start position:0% +and move up to escalating payouts so I + + + align:start position:0% +and move up to escalating payouts so I +want to make an important distinction + + align:start position:0% +want to make an important distinction + + + align:start position:0% +want to make an important distinction +though what I'm saying we're still + + align:start position:0% +though what I'm saying we're still + + + align:start position:0% +though what I'm saying we're still +trading maximize our expected amount of + + align:start position:0% +trading maximize our expected amount of + + + align:start position:0% +trading maximize our expected amount of +money what I'm saying you should be + + align:start position:0% +money what I'm saying you should be + + + align:start position:0% +money what I'm saying you should be +minimizing your risk in a tournament so + + align:start position:0% +minimizing your risk in a tournament so + + + align:start position:0% +minimizing your risk in a tournament so +that you can move up the payouts that is + + align:start position:0% +that you can move up the payouts that is + + + align:start position:0% +that you can move up the payouts that is +that's different than saying you should + + align:start position:0% +that's different than saying you should + + + align:start position:0% +that's different than saying you should +you should minimize your monetary risk + + align:start position:0% +you should minimize your monetary risk + + + align:start position:0% +you should minimize your monetary risk +because I'm still assuming returning + + align:start position:0% +because I'm still assuming returning + + + align:start position:0% +because I'm still assuming returning +maximize our expected money without + + align:start position:0% +maximize our expected money without + + + align:start position:0% +maximize our expected money without +worrying about risk but I'm only + + align:start position:0% +worrying about risk but I'm only + + + align:start position:0% +worrying about risk but I'm only +minimizing tournament risk to maximize + + align:start position:0% +minimizing tournament risk to maximize + + + align:start position:0% +minimizing tournament risk to maximize +our expected amount of money but I'm not + + align:start position:0% +our expected amount of money but I'm not + + + align:start position:0% +our expected amount of money but I'm not +saying we should be overly conservative + + align:start position:0% +saying we should be overly conservative + + + align:start position:0% +saying we should be overly conservative +in tournament and just trying to move up + + align:start position:0% +in tournament and just trying to move up + + + align:start position:0% +in tournament and just trying to move up +the money ladder slowly when you should + + align:start position:0% +the money ladder slowly when you should + + + align:start position:0% +the money ladder slowly when you should +be gambling because it's positive money + + align:start position:0% +be gambling because it's positive money + + + align:start position:0% +be gambling because it's positive money +expectation if you find yourself in this + + align:start position:0% +expectation if you find yourself in this + + + align:start position:0% +expectation if you find yourself in this +situation then you know if you're trying + + align:start position:0% +situation then you know if you're trying + + + align:start position:0% +situation then you know if you're trying +to play like professionally and just + + align:start position:0% +to play like professionally and just + + + align:start position:0% +to play like professionally and just +maximize your expected amount of money + + align:start position:0% +maximize your expected amount of money + + + align:start position:0% +maximize your expected amount of money +in every situation then you should + + align:start position:0% +in every situation then you should + + + align:start position:0% +in every situation then you should +probably play smaller tournaments where + + align:start position:0% +probably play smaller tournaments where + + + align:start position:0% +probably play smaller tournaments where +this is not really the key what if this + + align:start position:0% +this is not really the key what if this + + + align:start position:0% +this is not really the key what if this +doesn't occur to you often you know I + + align:start position:0% +doesn't occur to you often you know I + + + align:start position:0% +doesn't occur to you often you know I +can understand in practice like if you + + align:start position:0% +can understand in practice like if you + + + align:start position:0% +can understand in practice like if you +play poker for fun and you made it farm + + align:start position:0% +play poker for fun and you made it farm + + + align:start position:0% +play poker for fun and you made it farm +in front of it and you know it's like + + align:start position:0% +in front of it and you know it's like + + + align:start position:0% +in front of it and you know it's like +the top like let's say 50k and there's + + align:start position:0% +the top like let's say 50k and there's + + + align:start position:0% +the top like let's say 50k and there's +like 55 left you know I can understand + + align:start position:0% +like 55 left you know I can understand + + + align:start position:0% +like 55 left you know I can understand +why you might not want to make a + + align:start position:0% +why you might not want to make a + + + align:start position:0% +why you might not want to make a +positive money X a positive money + + align:start position:0% +positive money X a positive money + + + align:start position:0% +positive money X a positive money +expectation play because you know you've + + align:start position:0% +expectation play because you know you've + + + align:start position:0% +expectation play because you know you've +knew you've played this tournament + + align:start position:0% +knew you've played this tournament + + + align:start position:0% +knew you've played this tournament +you're probably not going to be in the + + align:start position:0% +you're probably not going to be in the + + + align:start position:0% +you're probably not going to be in the +situation that many times in your + + align:start position:0% +situation that many times in your + + + align:start position:0% +situation that many times in your +lifetime and you just really want to + + align:start position:0% +lifetime and you just really want to + + + align:start position:0% +lifetime and you just really want to +cash like the World Series of Poker Main + + align:start position:0% +cash like the World Series of Poker Main + + + align:start position:0% +cash like the World Series of Poker Main +Event or something and I think you know + + align:start position:0% +Event or something and I think you know + + + align:start position:0% +Event or something and I think you know +that's that's a reasonable life decision + + align:start position:0% +that's that's a reasonable life decision + + + align:start position:0% +that's that's a reasonable life decision +I'm not criticizing that decision but + + align:start position:0% +I'm not criticizing that decision but + + + align:start position:0% +I'm not criticizing that decision but +I'm just saying but I'm gonna talk about + + align:start position:0% +I'm just saying but I'm gonna talk about + + + align:start position:0% +I'm just saying but I'm gonna talk about +all these decisions assuming work we + + align:start position:0% +all these decisions assuming work we + + + align:start position:0% +all these decisions assuming work we +don't care about that we're still trying + + align:start position:0% +don't care about that we're still trying + + + align:start position:0% +don't care about that we're still trying +to maximize expected amount of money and + + align:start position:0% +to maximize expected amount of money and + + + align:start position:0% +to maximize expected amount of money and +if you aren't playing like + + align:start position:0% +if you aren't playing like + + + align:start position:0% +if you aren't playing like +professionally where you're getting into + + align:start position:0% +professionally where you're getting into + + + align:start position:0% +professionally where you're getting into +that situation very frequently then it + + align:start position:0% +that situation very frequently then it + + + align:start position:0% +that situation very frequently then it +is very important to maximize risk in + + align:start position:0% +is very important to maximize risk in + + + align:start position:0% +is very important to maximize risk in +some cases and to maximize your doll or + + align:start position:0% +some cases and to maximize your doll or + + + align:start position:0% +some cases and to maximize your doll or +evey because you know in tournaments + + align:start position:0% +evey because you know in tournaments + + + align:start position:0% +evey because you know in tournaments +you're losing most of the time you + + align:start position:0% +you're losing most of the time you + + + align:start position:0% +you're losing most of the time you +really have to win a lot the times that + + align:start position:0% +really have to win a lot the times that + + + align:start position:0% +really have to win a lot the times that +we do win you can't be content like you + + align:start position:0% +we do win you can't be content like you + + + align:start position:0% +we do win you can't be content like you +can't be content because we made like + + align:start position:0% +can't be content because we made like + + + align:start position:0% +can't be content because we made like +$30,000 + + align:start position:0% +$30,000 + + + align:start position:0% +$30,000 +that we could have made like fifty + + align:start position:0% +that we could have made like fifty + + + align:start position:0% +that we could have made like fifty +thousand dollars so okay so what is the + + align:start position:0% +thousand dollars so okay so what is the + + + align:start position:0% +thousand dollars so okay so what is the +exact formula from ICM so I'm just going + + align:start position:0% +exact formula from ICM so I'm just going + + + align:start position:0% +exact formula from ICM so I'm just going +to sort of demonstrate how to calculate + + align:start position:0% +to sort of demonstrate how to calculate + + + align:start position:0% +to sort of demonstrate how to calculate +the value chips in a tournament with an + + align:start position:0% +the value chips in a tournament with an + + + align:start position:0% +the value chips in a tournament with an +example so ICM is essentially a formula + + align:start position:0% +example so ICM is essentially a formula + + + align:start position:0% +example so ICM is essentially a formula +to calculate how much your stack is + + align:start position:0% +to calculate how much your stack is + + + align:start position:0% +to calculate how much your stack is +worth in a tournament so let's suppose + + align:start position:0% +worth in a tournament so let's suppose + + + align:start position:0% +worth in a tournament so let's suppose +there's three players left and the + + align:start position:0% +there's three players left and the + + + align:start position:0% +there's three players left and the +payoffs are five three two this is a + + align:start position:0% +payoffs are five three two this is a + + + align:start position:0% +payoffs are five three two this is a +common structure and likes it and goes + + align:start position:0% +common structure and likes it and goes + + + align:start position:0% +common structure and likes it and goes +if you play those which are like ten + + align:start position:0% +if you play those which are like ten + + + align:start position:0% +if you play those which are like ten +player tournaments so the statement is + + align:start position:0% +player tournaments so the statement is + + + align:start position:0% +player tournaments so the statement is +essentially your chances of winning the + + align:start position:0% +essentially your chances of winning the + + + align:start position:0% +essentially your chances of winning the +tournament is proportional to your + + align:start position:0% +tournament is proportional to your + + + align:start position:0% +tournament is proportional to your +percent of the total chips and + + align:start position:0% +percent of the total chips and + + + align:start position:0% +percent of the total chips and +essentially we're assuming this champion + + align:start position:0% +essentially we're assuming this champion + + + align:start position:0% +essentially we're assuming this champion +is true and we're going to derive from + + align:start position:0% +is true and we're going to derive from + + + align:start position:0% +is true and we're going to derive from +it all the formulas + + align:start position:0% +it all the formulas + + + align:start position:0% +it all the formulas +and this thing that is a proximal nature + + align:start position:0% +and this thing that is a proximal nature + + + align:start position:0% +and this thing that is a proximal nature +you know there are more advanced ICM + + align:start position:0% +you know there are more advanced ICM + + + align:start position:0% +you know there are more advanced ICM +calculators that also take into account + + align:start position:0% +calculators that also take into account + + + align:start position:0% +calculators that also take into account +your position if the stack sizes are + + align:start position:0% +your position if the stack sizes are + + + align:start position:0% +your position if the stack sizes are +rather shallow because there are some + + align:start position:0% +rather shallow because there are some + + + align:start position:0% +rather shallow because there are some +inaccuracies because this statement it + + align:start position:0% +inaccuracies because this statement it + + + align:start position:0% +inaccuracies because this statement it +calculates only based on chips but you + + align:start position:0% +calculates only based on chips but you + + + align:start position:0% +calculates only based on chips but you +know if you're folding and then you're + + align:start position:0% +know if you're folding and then you're + + + align:start position:0% +know if you're folding and then you're +the button the next hand which is the + + align:start position:0% +the button the next hand which is the + + + align:start position:0% +the button the next hand which is the +best position then that's actually sort + + align:start position:0% +best position then that's actually sort + + + align:start position:0% +best position then that's actually sort +of an entire big blind better almost + + align:start position:0% +of an entire big blind better almost + + + align:start position:0% +of an entire big blind better almost +then being under together the next but + + align:start position:0% +then being under together the next but + + + align:start position:0% +then being under together the next but +look more we're not going to worry about + + align:start position:0% +look more we're not going to worry about + + + align:start position:0% +look more we're not going to worry about +that we're just going to assume you're + + align:start position:0% +that we're just going to assume you're + + + align:start position:0% +that we're just going to assume you're +aware of chances of winning the + + align:start position:0% +aware of chances of winning the + + + align:start position:0% +aware of chances of winning the +tournament is proportional to your + + align:start position:0% +tournament is proportional to your + + + align:start position:0% +tournament is proportional to your +percentage chips so how do we calculate + + align:start position:0% +percentage chips so how do we calculate + + + align:start position:0% +percentage chips so how do we calculate +this so I sent it so okay so you can't + + align:start position:0% +this so I sent it so okay so you can't + + + align:start position:0% +this so I sent it so okay so you can't +really do it by hand in practice but for + + align:start position:0% +really do it by hand in practice but for + + + align:start position:0% +really do it by hand in practice but for +this example with three people I'll show + + align:start position:0% +this example with three people I'll show + + + align:start position:0% +this example with three people I'll show +you how to do it by hand so let's + + align:start position:0% +you how to do it by hand so let's + + + align:start position:0% +you how to do it by hand so let's +suppose the chip stamps are also five + + align:start position:0% +suppose the chip stamps are also five + + + align:start position:0% +suppose the chip stamps are also five +three two okay so the payouts are five + + align:start position:0% +three two okay so the payouts are five + + + align:start position:0% +three two okay so the payouts are five +three two and the chip stacks are also + + align:start position:0% +three two and the chip stacks are also + + + align:start position:0% +three two and the chip stacks are also +five three two ratio so you know if + + align:start position:0% +five three two ratio so you know if + + + align:start position:0% +five three two ratio so you know if +should be the equals money evie then the + + align:start position:0% +should be the equals money evie then the + + + align:start position:0% +should be the equals money evie then the +guy with five thousand their equity from + + align:start position:0% +guy with five thousand their equity from + + + align:start position:0% +guy with five thousand their equity from +the tournament should be five dollars + + align:start position:0% +the tournament should be five dollars + + + align:start position:0% +the tournament should be five dollars +and the guy in third place their equity + + align:start position:0% +and the guy in third place their equity + + + align:start position:0% +and the guy in third place their equity +should be two dollars right but this is + + align:start position:0% +should be two dollars right but this is + + + align:start position:0% +should be two dollars right but this is +clearly not correct right because the + + align:start position:0% +clearly not correct right because the + + + align:start position:0% +clearly not correct right because the +guy in third place is guaranteed two + + align:start position:0% +guy in third place is guaranteed two + + + align:start position:0% +guy in third place is guaranteed two +dollars and clearly there's a nonzero + + align:start position:0% +dollars and clearly there's a nonzero + + + align:start position:0% +dollars and clearly there's a nonzero +chance of them laying the tournament so + + align:start position:0% +chance of them laying the tournament so + + + align:start position:0% +chance of them laying the tournament so +clearly their equity is actually more + + align:start position:0% +clearly their equity is actually more + + + align:start position:0% +clearly their equity is actually more +than two dollars right and then + + align:start position:0% +than two dollars right and then + + + align:start position:0% +than two dollars right and then +similarly if your player a your equity + + align:start position:0% +similarly if your player a your equity + + + align:start position:0% +similarly if your player a your equity +is clearly not five dollars because + + align:start position:0% +is clearly not five dollars because + + + align:start position:0% +is clearly not five dollars because +you're not guaranteed to win they turn + + align:start position:0% +you're not guaranteed to win they turn + + + align:start position:0% +you're not guaranteed to win they turn +up right so it's clear from this example + + align:start position:0% +up right so it's clear from this example + + + align:start position:0% +up right so it's clear from this example +why if you just do chippy be equal + + align:start position:0% +why if you just do chippy be equal + + + align:start position:0% +why if you just do chippy be equal +people's money easy that's clearly wrong + + align:start position:0% +people's money easy that's clearly wrong + + + align:start position:0% +people's money easy that's clearly wrong +raise equity everyone so + + align:start position:0% +raise equity everyone so + + + align:start position:0% +raise equity everyone so +how do we calculate it it's okay so this + + align:start position:0% +how do we calculate it it's okay so this + + + align:start position:0% +how do we calculate it it's okay so this +is so let's calculate it for player to + + align:start position:0% +is so let's calculate it for player to + + + align:start position:0% +is so let's calculate it for player to +see so essentially what it's saying your + + align:start position:0% +see so essentially what it's saying your + + + align:start position:0% +see so essentially what it's saying your +chances of winning your chances are + + align:start position:0% +chances of winning your chances are + + + align:start position:0% +chances of winning your chances are +coming first is 2,000 + + align:start position:0% +coming first is 2,000 + + + align:start position:0% +coming first is 2,000 +over 10,000 which is 20% and then you + + align:start position:0% +over 10,000 which is 20% and then you + + + align:start position:0% +over 10,000 which is 20% and then you +calculate their chances of coming second + + align:start position:0% +calculate their chances of coming second + + + align:start position:0% +calculate their chances of coming second +you just condition on each of the other + + align:start position:0% +you just condition on each of the other + + + align:start position:0% +you just condition on each of the other +players way so conditioned on a winning + + align:start position:0% +players way so conditioned on a winning + + + align:start position:0% +players way so conditioned on a winning +which will happen 50% of the time we + + align:start position:0% +which will happen 50% of the time we + + + align:start position:0% +which will happen 50% of the time we +assume that our chances of coming second + + align:start position:0% +assume that our chances of coming second + + + align:start position:0% +assume that our chances of coming second +is 2,000 divided by 5,000 which is the + + align:start position:0% +is 2,000 divided by 5,000 which is the + + + align:start position:0% +is 2,000 divided by 5,000 which is the +remaining number of chips besides + + align:start position:0% +remaining number of chips besides + + + align:start position:0% +remaining number of chips besides +clutter a does that make sense so player + + align:start position:0% +clutter a does that make sense so player + + + align:start position:0% +clutter a does that make sense so player +a has 5,000 chips so between between use + + align:start position:0% +a has 5,000 chips so between between use + + + align:start position:0% +a has 5,000 chips so between between use +player C and player D you've got five + + align:start position:0% +player C and player D you've got five + + + align:start position:0% +player C and player D you've got five +deuce 5,000 ships in total and you've + + align:start position:0% +deuce 5,000 ships in total and you've + + + align:start position:0% +deuce 5,000 ships in total and you've +got 2,000 of those so it's 2,000 over + + align:start position:0% +got 2,000 of those so it's 2,000 over + + + align:start position:0% +got 2,000 of those so it's 2,000 over +5,000 so it's point four and then if + + align:start position:0% +5,000 so it's point four and then if + + + align:start position:0% +5,000 so it's point four and then if +player B wins then your chances of + + align:start position:0% +player B wins then your chances of + + + align:start position:0% +player B wins then your chances of +coming second is 2,000 over 7,000 so + + align:start position:0% +coming second is 2,000 over 7,000 so + + + align:start position:0% +coming second is 2,000 over 7,000 so +overall your chances are coming second + + align:start position:0% +overall your chances are coming second + + + align:start position:0% +overall your chances are coming second +is 0.42 + + align:start position:0% +is 0.42 + + + align:start position:0% +is 0.42 +so point is so yeah so it's just 50% + + align:start position:0% +so point is so yeah so it's just 50% + + + align:start position:0% +so point is so yeah so it's just 50% +times 0.4 plus 30% times 2/7 which + + align:start position:0% +times 0.4 plus 30% times 2/7 which + + + align:start position:0% +times 0.4 plus 30% times 2/7 which +equals 2/7 so then you can calculate + + align:start position:0% +equals 2/7 so then you can calculate + + + align:start position:0% +equals 2/7 so then you can calculate +your equity is they're guaranteed to + + align:start position:0% +your equity is they're guaranteed to + + + align:start position:0% +your equity is they're guaranteed to +bucks and you have a 20% chance of + + align:start position:0% +bucks and you have a 20% chance of + + + align:start position:0% +bucks and you have a 20% chance of +winning which will give you three + + align:start position:0% +winning which will give you three + + + align:start position:0% +winning which will give you three +additional dollars and then a 29% chance + + align:start position:0% +additional dollars and then a 29% chance + + + align:start position:0% +additional dollars and then a 29% chance +of coming second which will give you an + + align:start position:0% +of coming second which will give you an + + + align:start position:0% +of coming second which will give you an +additional dollar so your equity is + + align:start position:0% +additional dollar so your equity is + + + align:start position:0% +additional dollar so your equity is +actually 289 this displace this case + + align:start position:0% +actually 289 this displace this case + + + align:start position:0% +actually 289 this displace this case +it's actually closer to second place + + align:start position:0% +it's actually closer to second place + + + align:start position:0% +it's actually closer to second place +then third place does I have a place you + + align:start position:0% +then third place does I have a place you + + + align:start position:0% +then third place does I have a place you +make sense to everyone so if there is + + align:start position:0% +make sense to everyone so if there is + + + align:start position:0% +make sense to everyone so if there is +like five players you know you just have + + align:start position:0% +like five players you know you just have + + + align:start position:0% +like five players you know you just have +to recursively condition you have to + + align:start position:0% +to recursively condition you have to + + + align:start position:0% +to recursively condition you have to +condition on play a winning and then go + + align:start position:0% +condition on play a winning and then go + + + align:start position:0% +condition on play a winning and then go +through all the possibilities if you + + align:start position:0% +through all the possibilities if you + + + align:start position:0% +through all the possibilities if you +becomes second then go through all the + + align:start position:0% +becomes second then go through all the + + + align:start position:0% +becomes second then go through all the +possibilities if you becomes third etc + + align:start position:0% +possibilities if you becomes third etc + + + align:start position:0% +possibilities if you becomes third etc +etc so it's not a completion make them + + align:start position:0% +etc so it's not a completion make them + + + align:start position:0% +etc so it's not a completion make them +really do in your head it's but there + + align:start position:0% +really do in your head it's but there + + + align:start position:0% +really do in your head it's but there +that it's quite easy to find a + + align:start position:0% +that it's quite easy to find a + + + align:start position:0% +that it's quite easy to find a +calculator to do it for you on you just + + align:start position:0% +calculator to do it for you on you just + + + align:start position:0% +calculator to do it for you on you just +Google ICM calculator and you punch it + + align:start position:0% +Google ICM calculator and you punch it + + + align:start position:0% +Google ICM calculator and you punch it +in and and even though you know it's not + + align:start position:0% +in and and even though you know it's not + + + align:start position:0% +in and and even though you know it's not +like like your grows exponentially but + + align:start position:0% +like like your grows exponentially but + + + align:start position:0% +like like your grows exponentially but +you know there's only going to be like + + align:start position:0% +you know there's only going to be like + + + align:start position:0% +you know there's only going to be like +nine players so it's still fine and + + align:start position:0% +nine players so it's still fine and + + + align:start position:0% +nine players so it's still fine and +we'll take that though the computer can + + align:start position:0% +we'll take that though the computer can + + + align:start position:0% +we'll take that though the computer can +do it instantly even for nine ten + + align:start position:0% +do it instantly even for nine ten + + + align:start position:0% +do it instantly even for nine ten +players okay + + align:start position:0% +players okay + + + align:start position:0% +players okay +so what are some cases where ICM is easy + + align:start position:0% +so what are some cases where ICM is easy + + + align:start position:0% +so what are some cases where ICM is easy +to calculate so + + align:start position:0% +to calculate so + + + align:start position:0% +to calculate so +like I said in cash games there is no + + align:start position:0% +like I said in cash games there is no + + + align:start position:0% +like I said in cash games there is no +such thing as I see em you're just + + align:start position:0% +such thing as I see em you're just + + + align:start position:0% +such thing as I see em you're just +playing to maximize expected number of + + align:start position:0% +playing to maximize expected number of + + + align:start position:0% +playing to maximize expected number of +chips and your goal is essentially + + align:start position:0% +chips and your goal is essentially + + + align:start position:0% +chips and your goal is essentially +you're sitting down at the cash game + + align:start position:0% +you're sitting down at the cash game + + + align:start position:0% +you're sitting down at the cash game +looking to get into all and looking to + + align:start position:0% +looking to get into all and looking to + + + align:start position:0% +looking to get into all and looking to +get into favorable and hopefully winning + + align:start position:0% +get into favorable and hopefully winning + + + align:start position:0% +get into favorable and hopefully winning +the the person who you're targeting is + + align:start position:0% +the the person who you're targeting is + + + align:start position:0% +the the person who you're targeting is +light and turn and and winner takes all + + align:start position:0% +light and turn and and winner takes all + + + align:start position:0% +light and turn and and winner takes all +tournaments it's also the same the yours + + align:start position:0% +tournaments it's also the same the yours + + + align:start position:0% +tournaments it's also the same the yours +because you're just looking at your + + align:start position:0% +because you're just looking at your + + + align:start position:0% +because you're just looking at your +chances of winning the tournament and + + align:start position:0% +chances of winning the tournament and + + + align:start position:0% +chances of winning the tournament and +that's always just your number of chips + + align:start position:0% +that's always just your number of chips + + + align:start position:0% +that's always just your number of chips +so you're just trying to maximize + + align:start position:0% +so you're just trying to maximize + + + align:start position:0% +so you're just trying to maximize +expected number of chips so as a + + align:start position:0% +expected number of chips so as a + + + align:start position:0% +expected number of chips so as a +corollary once it gets down to two + + align:start position:0% +corollary once it gets down to two + + + align:start position:0% +corollary once it gets down to two +players there's no knows more such thing + + align:start position:0% +players there's no knows more such thing + + + align:start position:0% +players there's no knows more such thing +as I see em so sort of three is the + + align:start position:0% +as I see em so sort of three is the + + + align:start position:0% +as I see em so sort of three is the +minimum number of players you need for + + align:start position:0% +minimum number of players you need for + + + align:start position:0% +minimum number of players you need for +ICM to be relevant once it's two players + + align:start position:0% +ICM to be relevant once it's two players + + + align:start position:0% +ICM to be relevant once it's two players +it doesn't maximize your chip maybe + + align:start position:0% +it doesn't maximize your chip maybe + + + align:start position:0% +it doesn't maximize your chip maybe +because there's there's no sense of you + + align:start position:0% +because there's there's no sense of you + + + align:start position:0% +because there's there's no sense of you +know trying to survive who said someone + + align:start position:0% +know trying to survive who said someone + + + align:start position:0% +know trying to survive who said someone +else busts first because with only two + + align:start position:0% +else busts first because with only two + + + align:start position:0% +else busts first because with only two +people for the other guy bus do you have + + align:start position:0% +people for the other guy bus do you have + + + align:start position:0% +people for the other guy bus do you have +to you have to take all their chips okay + + align:start position:0% + + + + align:start position:0% + +so what are some mathematical qualities + + align:start position:0% +so what are some mathematical qualities + + + align:start position:0% +so what are some mathematical qualities +of the LCM formula so big sacks have + + align:start position:0% +of the LCM formula so big sacks have + + + align:start position:0% +of the LCM formula so big sacks have +money easy less than ship TV small + + align:start position:0% +money easy less than ship TV small + + + align:start position:0% +money easy less than ship TV small +snacks have money you need greater than + + align:start position:0% +snacks have money you need greater than + + + align:start position:0% +snacks have money you need greater than +ship TV small + + align:start position:0% +ship TV small + + + align:start position:0% +ship TV small +sex also tend to have positive shitty B + + align:start position:0% +sex also tend to have positive shitty B + + + align:start position:0% +sex also tend to have positive shitty B +in general this is something I didn't + + align:start position:0% +in general this is something I didn't + + + align:start position:0% +in general this is something I didn't +mention too much but in general so you + + align:start position:0% +mention too much but in general so you + + + align:start position:0% +mention too much but in general so you +might have seen this if you guys have + + align:start position:0% +might have seen this if you guys have + + + align:start position:0% +might have seen this if you guys have +like Bindu casino and play cash games so + + align:start position:0% +like Bindu casino and play cash games so + + + align:start position:0% +like Bindu casino and play cash games so +like let's say you sit down at a table + + align:start position:0% +like let's say you sit down at a table + + + align:start position:0% +like let's say you sit down at a table +with in a cash game and evarin buys it + + align:start position:0% +with in a cash game and evarin buys it + + + align:start position:0% +with in a cash game and evarin buys it +for like a hundred big blinds at some + + align:start position:0% +for like a hundred big blinds at some + + + align:start position:0% +for like a hundred big blinds at some +tables usually they'll allow you to buy + + align:start position:0% +tables usually they'll allow you to buy + + + align:start position:0% +tables usually they'll allow you to buy +in for as low as like 20 big blinds and + + align:start position:0% +in for as low as like 20 big blinds and + + + align:start position:0% +in for as low as like 20 big blinds and +if you do this in general that's gonna + + align:start position:0% +if you do this in general that's gonna + + + align:start position:0% +if you do this in general that's gonna +be positive evie for the guy with 20 big + + align:start position:0% +be positive evie for the guy with 20 big + + + align:start position:0% +be positive evie for the guy with 20 big +blinds because there's situations where + + align:start position:0% +blinds because there's situations where + + + align:start position:0% +blinds because there's situations where +they have to wear like let's say they + + align:start position:0% +they have to wear like let's say they + + + align:start position:0% +they have to wear like let's say they +have to essentially sometimes one guy + + align:start position:0% +have to essentially sometimes one guy + + + align:start position:0% +have to essentially sometimes one guy +will raise one guy will call and then + + align:start position:0% +will raise one guy will call and then + + + align:start position:0% +will raise one guy will call and then +you can go on and then one guy will like + + align:start position:0% +you can go on and then one guy will like + + + align:start position:0% +you can go on and then one guy will like +go all in on top of you and the other + + align:start position:0% +go all in on top of you and the other + + + align:start position:0% +go all in on top of you and the other +guy will fold and then you'll have like + + align:start position:0% +guy will fold and then you'll have like + + + align:start position:0% +guy will fold and then you'll have like +good money so + + align:start position:0% +good money so + + + align:start position:0% +good money so +another thing is early on in the + + align:start position:0% +another thing is early on in the + + + align:start position:0% +another thing is early on in the +tournament ICM is irrelevant you just + + align:start position:0% +tournament ICM is irrelevant you just + + + align:start position:0% +tournament ICM is irrelevant you just +want to can relate chips so like if you + + align:start position:0% +want to can relate chips so like if you + + + align:start position:0% +want to can relate chips so like if you +you know if you try to do this formula + + align:start position:0% +you know if you try to do this formula + + + align:start position:0% +you know if you try to do this formula +early on in a tournament what you'll + + align:start position:0% +early on in a tournament what you'll + + + align:start position:0% +early on in a tournament what you'll +find is essentially the + + align:start position:0% +find is essentially the + + + align:start position:0% +find is essentially the +essentially you're so far away from the + + align:start position:0% +essentially you're so far away from the + + + align:start position:0% +essentially you're so far away from the +money that none of the things really + + align:start position:0% +money that none of the things really + + + align:start position:0% +money that none of the things really +matter to maximize your chances of even + + align:start position:0% +matter to maximize your chances of even + + + align:start position:0% +matter to maximize your chances of even +getting through the money you just wanna + + align:start position:0% +getting through the money you just wanna + + + align:start position:0% +getting through the money you just wanna +maximize your number of chairs so + + align:start position:0% +maximize your number of chairs so + + + align:start position:0% +maximize your number of chairs so +where does I see a most relevant it's + + align:start position:0% +where does I see a most relevant it's + + + align:start position:0% +where does I see a most relevant it's +most relevant on the exact pay level and + + align:start position:0% +most relevant on the exact pay level and + + + align:start position:0% +most relevant on the exact pay level and +on the final table so let me so roughly + + align:start position:0% +on the final table so let me so roughly + + + align:start position:0% +on the final table so let me so roughly +speaking in every took poker tournament + + align:start position:0% +speaking in every took poker tournament + + + align:start position:0% +speaking in every took poker tournament +I've seen other than like strange ones + + align:start position:0% +I've seen other than like strange ones + + + align:start position:0% +I've seen other than like strange ones +that are like winter takes all our + + align:start position:0% +that are like winter takes all our + + + align:start position:0% +that are like winter takes all our +satellites the pay looks roughly like + + align:start position:0% +satellites the pay looks roughly like + + + align:start position:0% +satellites the pay looks roughly like +this so so it's zero you go in and once + + align:start position:0% +this so so it's zero you go in and once + + + align:start position:0% +this so so it's zero you go in and once +you hit about top twenty percent is the + + align:start position:0% +you hit about top twenty percent is the + + + align:start position:0% +you hit about top twenty percent is the +bubble and then there's like a jump here + + align:start position:0% +bubble and then there's like a jump here + + + align:start position:0% +bubble and then there's like a jump here +or suddenly you get paid so this is + + align:start position:0% +or suddenly you get paid so this is + + + align:start position:0% +or suddenly you get paid so this is +about this is about 80 percent get zero + + align:start position:0% +about this is about 80 percent get zero + + + align:start position:0% +about this is about 80 percent get zero +and then so here there's a jump and then + + align:start position:0% +and then so here there's a jump and then + + + align:start position:0% +and then so here there's a jump and then +it escalates slowly until you get to the + + align:start position:0% +it escalates slowly until you get to the + + + align:start position:0% +it escalates slowly until you get to the +final table + + align:start position:0% +final table + + + align:start position:0% +final table +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +final survey is my sister she's color + + align:start position:0% +final survey is my sister she's color + + + align:start position:0% +final survey is my sister she's color +I know table and then it escalates + + align:start position:0% +I know table and then it escalates + + + align:start position:0% +I know table and then it escalates +really fast so essentially basically I + + align:start position:0% +really fast so essentially basically I + + + align:start position:0% +really fast so essentially basically I +see them as most relevant at the points + + align:start position:0% +see them as most relevant at the points + + + align:start position:0% +see them as most relevant at the points +where like essentially the derivative or + + align:start position:0% +where like essentially the derivative or + + + align:start position:0% +where like essentially the derivative or +the rate of change of the payout is + + align:start position:0% +the rate of change of the payout is + + + align:start position:0% +the rate of change of the payout is +highest and those points as you can see + + align:start position:0% +highest and those points as you can see + + + align:start position:0% +highest and those points as you can see +are here and here so essentially it + + align:start position:0% +are here and here so essentially it + + + align:start position:0% +are here and here so essentially it +matters most at the exact money bubble + + align:start position:0% +matters most at the exact money bubble + + + align:start position:0% +matters most at the exact money bubble +and in the final table okay + + align:start position:0% +and in the final table okay + + + align:start position:0% +and in the final table okay +let me clear this okay + + align:start position:0% + + + + align:start position:0% + +so yeah so some more extreme examples of + + align:start position:0% +so yeah so some more extreme examples of + + + align:start position:0% +so yeah so some more extreme examples of +ICM is you have one ship let left late + + align:start position:0% +ICM is you have one ship let left late + + + align:start position:0% +ICM is you have one ship let left late +in a tournament when everyone else has + + align:start position:0% +in a tournament when everyone else has + + + align:start position:0% +in a tournament when everyone else has +thousands of chips so clearly this ship + + align:start position:0% +thousands of chips so clearly this ship + + + align:start position:0% +thousands of chips so clearly this ship +is worth a lot more than its value as a + + align:start position:0% +is worth a lot more than its value as a + + + align:start position:0% +is worth a lot more than its value as a +fraction of the chips and your is trying + + align:start position:0% +fraction of the chips and your is trying + + + align:start position:0% +fraction of the chips and your is trying +to survive with this one chip + + align:start position:0% +to survive with this one chip + + + align:start position:0% +to survive with this one chip +essentially instead of trying to win + + align:start position:0% +essentially instead of trying to win + + + align:start position:0% +essentially instead of trying to win +more chips and and so maybe maybe I was + + align:start position:0% +more chips and and so maybe maybe I was + + + align:start position:0% +more chips and and so maybe maybe I was +talking about this in a bit so in + + align:start position:0% +talking about this in a bit so in + + + align:start position:0% +talking about this in a bit so in +satellites so sad what satellites are + + align:start position:0% +satellites so sad what satellites are + + + align:start position:0% +satellites so sad what satellites are +there tournaments where you're trying to + + align:start position:0% +there tournaments where you're trying to + + + align:start position:0% +there tournaments where you're trying to +qualify for a bigger tournament so + + align:start position:0% +qualify for a bigger tournament so + + + align:start position:0% +qualify for a bigger tournament so +essentially the important thing is so + + align:start position:0% +essentially the important thing is so + + + align:start position:0% +essentially the important thing is so +you know there will be maybe like a + + align:start position:0% +you know there will be maybe like a + + + align:start position:0% +you know there will be maybe like a +hundred players and there will be ten + + align:start position:0% +hundred players and there will be ten + + + align:start position:0% +hundred players and there will be ten +seats which means the top ten get an + + align:start position:0% +seats which means the top ten get an + + + align:start position:0% +seats which means the top ten get an +invite to the bigger tournament and then + + align:start position:0% +invite to the bigger tournament and then + + + align:start position:0% +invite to the bigger tournament and then +everyone else gets nothing so answer the + + align:start position:0% +everyone else gets nothing so answer the + + + align:start position:0% +everyone else gets nothing so answer the +qualifiers for the MIT Series of Poker + + align:start position:0% +qualifiers for the MIT Series of Poker + + + align:start position:0% +qualifiers for the MIT Series of Poker +Main Event are kind of like this right + + align:start position:0% +Main Event are kind of like this right + + + align:start position:0% +Main Event are kind of like this right +it says your eternity I guess there's + + align:start position:0% +it says your eternity I guess there's + + + align:start position:0% +it says your eternity I guess there's +other prizes too but you're essentially + + align:start position:0% +other prizes too but you're essentially + + + align:start position:0% +other prizes too but you're essentially +trying to come to Talk 10 so this is how + + align:start position:0% +trying to come to Talk 10 so this is how + + + align:start position:0% +trying to come to Talk 10 so this is how +that works and in that case right the + + align:start position:0% +that works and in that case right the + + + align:start position:0% +that works and in that case right the +pay though is the payout is essentially + + align:start position:0% +pay though is the payout is essentially + + + align:start position:0% +pay though is the payout is essentially +this so there's not really much + + align:start position:0% +this so there's not really much + + + align:start position:0% +this so there's not really much +incentive to win you're just trying to + + align:start position:0% +incentive to win you're just trying to + + + align:start position:0% +incentive to win you're just trying to +be one of this top 10% that gets paid so + + align:start position:0% +be one of this top 10% that gets paid so + + + align:start position:0% +be one of this top 10% that gets paid so +that's another case where ICM has + + align:start position:0% +that's another case where ICM has + + + align:start position:0% +that's another case where ICM has +extreme importance and you often find + + align:start position:0% +extreme importance and you often find + + + align:start position:0% +extreme importance and you often find +you are not often but you can often make + + align:start position:0% +you are not often but you can often make + + + align:start position:0% +you are not often but you can often make +a case for folding pocket aces pretty + + align:start position:0% +a case for folding pocket aces pretty + + + align:start position:0% +a case for folding pocket aces pretty +fun even though it's even though you + + align:start position:0% +fun even though it's even though you + + + align:start position:0% +fun even though it's even though you +know it's gonna have positive chip TV if + + align:start position:0% +know it's gonna have positive chip TV if + + + align:start position:0% +know it's gonna have positive chip TV if +you call because it's the best possible + + align:start position:0% +you call because it's the best possible + + + align:start position:0% +you call because it's the best possible +hand but because you just really don't + + align:start position:0% +hand but because you just really don't + + + align:start position:0% +hand but because you just really don't +want to bust then you actually want to + + align:start position:0% +want to bust then you actually want to + + + align:start position:0% +want to bust then you actually want to +fold theses okay we'll talk about this a + + align:start position:0% +fold theses okay we'll talk about this a + + + align:start position:0% +fold theses okay we'll talk about this a +bit more later later or less get to okay + + align:start position:0% +bit more later later or less get to okay + + + align:start position:0% +bit more later later or less get to okay +so let's get back to the tournament so + + align:start position:0% +so let's get back to the tournament so + + + align:start position:0% +so let's get back to the tournament so +this is the final table so + + align:start position:0% +this is the final table so + + + align:start position:0% +this is the final table so +ICM is going to be quite relevant here + + align:start position:0% +ICM is going to be quite relevant here + + + align:start position:0% +ICM is going to be quite relevant here +and so I as I'm talking through my + + align:start position:0% +and so I as I'm talking through my + + + align:start position:0% +and so I as I'm talking through my +decisions in the hands I'll talk about + + align:start position:0% +decisions in the hands I'll talk about + + + align:start position:0% +decisions in the hands I'll talk about +sort of the ICM decisions as well okay + + align:start position:0% +sort of the ICM decisions as well okay + + + align:start position:0% +sort of the ICM decisions as well okay +so this is a + + align:start position:0% +so this is a + + + align:start position:0% +so this is a +this is the first hand or I think might + + align:start position:0% +this is the first hand or I think might + + + align:start position:0% +this is the first hand or I think might +have maybe one orbit past but so we're + + align:start position:0% +have maybe one orbit past but so we're + + + align:start position:0% +have maybe one orbit past but so we're +at the final table we're right now we're + + align:start position:0% +at the final table we're right now we're + + + align:start position:0% +at the final table we're right now we're +the second biggest stack and so yeah we + + align:start position:0% +the second biggest stack and so yeah we + + + align:start position:0% +the second biggest stack and so yeah we +should maybe look at the stack sizes so + + align:start position:0% +should maybe look at the stack sizes so + + + align:start position:0% +should maybe look at the stack sizes so +we look around at the stack sizes so so + + align:start position:0% +we look around at the stack sizes so so + + + align:start position:0% +we look around at the stack sizes so so +what do you notice about this access or + + align:start position:0% +what do you notice about this access or + + + align:start position:0% +what do you notice about this access or +like specifically like how are we doing + + align:start position:0% +like specifically like how are we doing + + + align:start position:0% +like specifically like how are we doing +how many just how many chips we have + + align:start position:0% +how many just how many chips we have + + + align:start position:0% +how many just how many chips we have +we'll + + align:start position:0% +we'll + + + align:start position:0% +we'll +right + + align:start position:0% +right + + + align:start position:0% +right +we have quite a lot right we have quite + + align:start position:0% +we have quite a lot right we have quite + + + align:start position:0% +we have quite a lot right we have quite +a lot but we're not in the first place + + align:start position:0% +a lot but we're not in the first place + + + align:start position:0% +a lot but we're not in the first place +there's this one guy who covers us so + + align:start position:0% +there's this one guy who covers us so + + + align:start position:0% +there's this one guy who covers us so +this pen hand Krissy guy uh if you + + align:start position:0% +this pen hand Krissy guy uh if you + + + align:start position:0% +this pen hand Krissy guy uh if you +covers us so specifically + + align:start position:0% +covers us so specifically + + + align:start position:0% +covers us so specifically +the thing I'm trying to avoid is getting + + align:start position:0% +the thing I'm trying to avoid is getting + + + align:start position:0% +the thing I'm trying to avoid is getting +in a big pot with Pam and Chrissy like I + + align:start position:0% +in a big pot with Pam and Chrissy like I + + + align:start position:0% +in a big pot with Pam and Chrissy like I +mean let's say she goes all in and I + + align:start position:0% +mean let's say she goes all in and I + + + align:start position:0% +mean let's say she goes all in and I +have pocket kings I'm gonna call but I'm + + align:start position:0% +have pocket kings I'm gonna call but I'm + + + align:start position:0% +have pocket kings I'm gonna call but I'm +not going to be that happy about calling + + align:start position:0% +not going to be that happy about calling + + + align:start position:0% +not going to be that happy about calling +in a situation where otherwise I should + + align:start position:0% +in a situation where otherwise I should + + + align:start position:0% +in a situation where otherwise I should +be very happy just because you know + + align:start position:0% +be very happy just because you know + + + align:start position:0% +be very happy just because you know +chances are he's gonna have an ace he's + + align:start position:0% +chances are he's gonna have an ace he's + + + align:start position:0% +chances are he's gonna have an ace he's +gonna have 30% equity I mean it's no + + align:start position:0% +gonna have 30% equity I mean it's no + + + align:start position:0% +gonna have 30% equity I mean it's no +gonna be positive money you need to call + + align:start position:0% +gonna be positive money you need to call + + + align:start position:0% +gonna be positive money you need to call +but it's so bad if I basically bust + + align:start position:0% +but it's so bad if I basically bust + + + align:start position:0% +but it's so bad if I basically bust +right now in eighth place against the + + align:start position:0% +right now in eighth place against the + + + align:start position:0% +right now in eighth place against the +damn hangers so essentially I'm really + + align:start position:0% +damn hangers so essentially I'm really + + + align:start position:0% +damn hangers so essentially I'm really +incentivized to avoid like getting in + + align:start position:0% +incentivized to avoid like getting in + + + align:start position:0% +incentivized to avoid like getting in +big pots of them and I'm essentially + + align:start position:0% +big pots of them and I'm essentially + + + align:start position:0% +big pots of them and I'm essentially +hoping for some of these smaller stacks + + align:start position:0% +hoping for some of these smaller stacks + + + align:start position:0% +hoping for some of these smaller stacks +to bust so that then even if I lose a + + align:start position:0% +to bust so that then even if I lose a + + + align:start position:0% +to bust so that then even if I lose a +big pot to him I don't get the low + + align:start position:0% +big pot to him I don't get the low + + + align:start position:0% +big pot to him I don't get the low +eighth place payoff so okay so it's + + align:start position:0% +eighth place payoff so okay so it's + + + align:start position:0% +eighth place payoff so okay so it's +folded to us we raise here I think this + + align:start position:0% +folded to us we raise here I think this + + + align:start position:0% +folded to us we raise here I think this +is one of the weakest hands I I'm + + align:start position:0% +is one of the weakest hands I I'm + + + align:start position:0% +is one of the weakest hands I I'm +raising from the button but so far + + align:start position:0% +raising from the button but so far + + + align:start position:0% +raising from the button but so far +players have seemed to be reasonably + + align:start position:0% +players have seemed to be reasonably + + + align:start position:0% +players have seemed to be reasonably +tight so I'm gonna raise and then I get + + align:start position:0% +tight so I'm gonna raise and then I get + + + align:start position:0% +tight so I'm gonna raise and then I get +the blinds okay + + align:start position:0% + + + + align:start position:0% + +so I'll supposed to give some hands at + + align:start position:0% +so I'll supposed to give some hands at + + + align:start position:0% +so I'll supposed to give some hands at +the beginning near the end they'll apply + + align:start position:0% +the beginning near the end they'll apply + + + align:start position:0% +the beginning near the end they'll apply +every hand this thing we don't play but + + align:start position:0% +every hand this thing we don't play but + + + align:start position:0% +every hand this thing we don't play but +I'll try to show the hands were someone + + align:start position:0% +I'll try to show the hands were someone + + + align:start position:0% +I'll try to show the hands were someone +busts so this hand small one goes all in + + align:start position:0% +busts so this hand small one goes all in + + + align:start position:0% +busts so this hand small one goes all in +big blind calls and so + + align:start position:0% +big blind calls and so + + + align:start position:0% +big blind calls and so +small mine wins with ten to suited + + align:start position:0% +small mine wins with ten to suited + + + align:start position:0% +small mine wins with ten to suited +against ace 4 which is basically great + + align:start position:0% +against ace 4 which is basically great + + + align:start position:0% +against ace 4 which is basically great +for everyone because someone busted + + align:start position:0% +for everyone because someone busted + + + align:start position:0% +for everyone because someone busted +you're always cheering for people to + + align:start position:0% +you're always cheering for people to + + + align:start position:0% +you're always cheering for people to +bust especially and + + align:start position:0% +bust especially and + + + align:start position:0% +bust especially and +I think also both of their plays are + + align:start position:0% +I think also both of their plays are + + + align:start position:0% +I think also both of their plays are +fine so I think small with small minds + + align:start position:0% +fine so I think small with small minds + + + align:start position:0% +fine so I think small with small minds +play it looks a bit silly but + + align:start position:0% +play it looks a bit silly but + + + align:start position:0% +play it looks a bit silly but +realistically not + + align:start position:0% +realistically not + + + align:start position:0% +realistically not +only does 10 - reasonable equity when + + align:start position:0% +only does 10 - reasonable equity when + + + align:start position:0% +only does 10 - reasonable equity when +you're called it's also the ICM is very + + align:start position:0% +you're called it's also the ICM is very + + + align:start position:0% +you're called it's also the ICM is very +very very developed like this Gerard ox + + align:start position:0% +very very developed like this Gerard ox + + + align:start position:0% +very very developed like this Gerard ox +died he's + + align:start position:0% +died he's + + + align:start position:0% +died he's +not the shortest I mean he is one of the + + align:start position:0% +not the shortest I mean he is one of the + + + align:start position:0% +not the shortest I mean he is one of the +shortest so he does need to take some + + align:start position:0% +shortest so he does need to take some + + + align:start position:0% +shortest so he does need to take some +risk but he's still really very much + + align:start position:0% +risk but he's still really very much + + + align:start position:0% +risk but he's still really very much +would like to bust after I show to hit + + align:start position:0% +would like to bust after I show to hit + + + align:start position:0% +would like to bust after I show to hit +78 so he so he can't call with anything + + align:start position:0% +78 so he so he can't call with anything + + + align:start position:0% +78 so he so he can't call with anything +I mean with ace floor I think that's + + align:start position:0% +I mean with ace floor I think that's + + + align:start position:0% +I mean with ace floor I think that's +definitely good enough to call but let's + + align:start position:0% +definitely good enough to call but let's + + + align:start position:0% +definitely good enough to call but let's +say they have like king two officers I + + align:start position:0% +say they have like king two officers I + + + align:start position:0% +say they have like king two officers I +think that's a situation I do normally + + align:start position:0% +think that's a situation I do normally + + + align:start position:0% +think that's a situation I do normally +call if it was like not a final table + + align:start position:0% +call if it was like not a final table + + + align:start position:0% +call if it was like not a final table +under tournament but I had a final table + + align:start position:0% +under tournament but I had a final table + + + align:start position:0% +under tournament but I had a final table +where I'm not the shortest and there's + + align:start position:0% +where I'm not the shortest and there's + + + align:start position:0% +where I'm not the shortest and there's +someone shorter than me I would consider + + align:start position:0% +someone shorter than me I would consider + + + align:start position:0% +someone shorter than me I would consider +folding tend to cert King to offsuit + + align:start position:0% +folding tend to cert King to offsuit + + + align:start position:0% +folding tend to cert King to offsuit +here just because um just because of ICM + + align:start position:0% +here just because um just because of ICM + + + align:start position:0% +here just because um just because of ICM +essentially all + + align:start position:0% + + + + align:start position:0% + +right so the next hand so so the so the + + align:start position:0% +right so the next hand so so the so the + + + align:start position:0% +right so the next hand so so the so the +big blind busts and then there's no + + align:start position:0% +big blind busts and then there's no + + + align:start position:0% +big blind busts and then there's no +small line this sandwich is great + + align:start position:0% +small line this sandwich is great + + + align:start position:0% +small line this sandwich is great +because where people are less than sent + + align:start position:0% +because where people are less than sent + + + align:start position:0% +because where people are less than sent +device of steel and indeed we get our + + align:start position:0% +device of steel and indeed we get our + + + align:start position:0% +device of steel and indeed we get our +nice + + align:start position:0% +nice + + + align:start position:0% +nice +it's + + align:start position:0% +it's + + + align:start position:0% +it's +not much happens here I'll skip forward + + align:start position:0% +not much happens here I'll skip forward + + + align:start position:0% +not much happens here I'll skip forward +a bit okay + + align:start position:0% + + + + align:start position:0% + +this hand I guess it's quite convenient + + align:start position:0% +this hand I guess it's quite convenient + + + align:start position:0% +this hand I guess it's quite convenient +for us but this'll illustrate the points + + align:start position:0% +for us but this'll illustrate the points + + + align:start position:0% +for us but this'll illustrate the points +so okay so so this guy who doesn't love + + align:start position:0% +so okay so so this guy who doesn't love + + + align:start position:0% +so okay so so this guy who doesn't love +a bit earlier right now he goes on and + + align:start position:0% +a bit earlier right now he goes on and + + + align:start position:0% +a bit earlier right now he goes on and +for quite a lot right this is quite a + + align:start position:0% +for quite a lot right this is quite a + + + align:start position:0% +for quite a lot right this is quite a +big shove and if you plenty by my + + align:start position:0% +big shove and if you plenty by my + + + align:start position:0% +big shove and if you plenty by my +recommendations I would never recommend + + align:start position:0% +recommendations I would never recommend + + + align:start position:0% +recommendations I would never recommend +shoving like this this many bets I mean + + align:start position:0% +shoving like this this many bets I mean + + + align:start position:0% +shoving like this this many bets I mean +it's not it's like 24 it's quite great + + align:start position:0% +it's not it's like 24 it's quite great + + + align:start position:0% +it's not it's like 24 it's quite great +actually 23 it says 23 23 big blinds + + align:start position:0% +actually 23 it says 23 23 big blinds + + + align:start position:0% +actually 23 it says 23 23 big blinds +which is like wage you watch the show + + align:start position:0% +which is like wage you watch the show + + + align:start position:0% +which is like wage you watch the show +right there's no need you can't risk + + align:start position:0% +right there's no need you can't risk + + + align:start position:0% +right there's no need you can't risk +this much but once again I think his + + align:start position:0% +this much but once again I think his + + + align:start position:0% +this much but once again I think his +play is justifiable because of ICM you + + align:start position:0% +play is justifiable because of ICM you + + + align:start position:0% +play is justifiable because of ICM you +know he doesn't and so ok so let's see + + align:start position:0% +know he doesn't and so ok so let's see + + + align:start position:0% +know he doesn't and so ok so let's see +what he had so we call I mean here it's + + align:start position:0% +what he had so we call I mean here it's + + + align:start position:0% +what he had so we call I mean here it's +a bit different because even if I call + + align:start position:0% +a bit different because even if I call + + + align:start position:0% +a bit different because even if I call +and lose I'm not out of the tournament + + align:start position:0% +and lose I'm not out of the tournament + + + align:start position:0% +and lose I'm not out of the tournament +and I mean even if I even if I'm what + + align:start position:0% +and I mean even if I even if I'm what + + + align:start position:0% +and I mean even if I even if I'm what +would be out like even if you have to mm + + align:start position:0% +would be out like even if you have to mm + + + align:start position:0% +would be out like even if you have to mm +I'd probably still call with Queens mr. + + align:start position:0% +I'd probably still call with Queens mr. + + + align:start position:0% +I'd probably still call with Queens mr. +beautiful so + + align:start position:0% +beautiful so + + + align:start position:0% +beautiful so +we need a screen here which is great for + + align:start position:0% +we need a screen here which is great for + + + align:start position:0% +we need a screen here which is great for +us but if you look at the play from his + + align:start position:0% +us but if you look at the play from his + + + align:start position:0% +us but if you look at the play from his +perspective again it actually seems + + align:start position:0% +perspective again it actually seems + + + align:start position:0% +perspective again it actually seems +quite reasonable if you think about it + + align:start position:0% +quite reasonable if you think about it + + + align:start position:0% +quite reasonable if you think about it +because you know for him ace queen is a + + align:start position:0% +because you know for him ace queen is a + + + align:start position:0% +because you know for him ace queen is a +great hand from this position it's + + align:start position:0% +great hand from this position it's + + + align:start position:0% +great hand from this position it's +definitely good enough where you know if + + align:start position:0% +definitely good enough where you know if + + + align:start position:0% +definitely good enough where you know if +it was between folding and shoving for + + align:start position:0% +it was between folding and shoving for + + + align:start position:0% +it was between folding and shoving for +23 big blinds you would definitely + + align:start position:0% +23 big blinds you would definitely + + + align:start position:0% +23 big blinds you would definitely +rather rather show for 23 big blinds so + + align:start position:0% +rather rather show for 23 big blinds so + + + align:start position:0% +rather rather show for 23 big blinds so +you know the main reason why normally + + align:start position:0% +you know the main reason why normally + + + align:start position:0% +you know the main reason why normally +one would criticize his play is because + + align:start position:0% +one would criticize his play is because + + + align:start position:0% +one would criticize his play is because +you know why that wasn't he just made a + + align:start position:0% +you know why that wasn't he just made a + + + align:start position:0% +you know why that wasn't he just made a +small with ace Queen well understandably + + align:start position:0% +small with ace Queen well understandably + + + align:start position:0% +small with ace Queen well understandably +he doesn't really want you want to + + align:start position:0% +he doesn't really want you want to + + + align:start position:0% +he doesn't really want you want to +incentivize me to like rebates or panca + + align:start position:0% +incentivize me to like rebates or panca + + + align:start position:0% +incentivize me to like rebates or panca +see to make a tree raise he actually + + align:start position:0% +see to make a tree raise he actually + + + align:start position:0% +see to make a tree raise he actually +wants to minimize the chances that he + + align:start position:0% +wants to minimize the chances that he + + + align:start position:0% +wants to minimize the chances that he +actually played for his stack in this + + align:start position:0% +actually played for his stack in this + + + align:start position:0% +actually played for his stack in this +hand and the way he does that is + + align:start position:0% +hand and the way he does that is + + + align:start position:0% +hand and the way he does that is +essentially by going all-in so if so you + + align:start position:0% +essentially by going all-in so if so you + + + align:start position:0% +essentially by going all-in so if so you +know looking looking at back at it I + + align:start position:0% +know looking looking at back at it I + + + align:start position:0% +know looking looking at back at it I +think his play is fine the only weakness + + align:start position:0% +think his play is fine the only weakness + + + align:start position:0% +think his play is fine the only weakness +of his play I think is it is a bit sort + + align:start position:0% +of his play I think is it is a bit sort + + + align:start position:0% +of his play I think is it is a bit sort +of predictable what his hand is in this + + align:start position:0% +of predictable what his hand is in this + + + align:start position:0% +of predictable what his hand is in this +situation because I think like if he had + + align:start position:0% +situation because I think like if he had + + + align:start position:0% +situation because I think like if he had +a hand as good as pocket aces then he + + align:start position:0% +a hand as good as pocket aces then he + + + align:start position:0% +a hand as good as pocket aces then he +shouldn't be doing this he should just + + align:start position:0% +shouldn't be doing this he should just + + + align:start position:0% +shouldn't be doing this he should just +be raising small because it's good + + align:start position:0% +be raising small because it's good + + + align:start position:0% +be raising small because it's good +enough where he's happy getting it in + + align:start position:0% +enough where he's happy getting it in + + + align:start position:0% +enough where he's happy getting it in +against me or pan-pan chrissie where is + + align:start position:0% +against me or pan-pan chrissie where is + + + align:start position:0% +against me or pan-pan chrissie where is +you know also if his hand was slightly + + align:start position:0% +you know also if his hand was slightly + + + align:start position:0% +you know also if his hand was slightly +worse like East Jack offsuit I think is + + align:start position:0% +worse like East Jack offsuit I think is + + + align:start position:0% +worse like East Jack offsuit I think is +a good example I think ace Jack offsuit + + align:start position:0% +a good example I think ace Jack offsuit + + + align:start position:0% +a good example I think ace Jack offsuit +is is not strong enough to make this all + + align:start position:0% +is is not strong enough to make this all + + + align:start position:0% +is is not strong enough to make this all +and play with but you still want to be + + align:start position:0% +and play with but you still want to be + + + align:start position:0% +and play with but you still want to be +raising so I think there's a small range + + align:start position:0% +raising so I think there's a small range + + + align:start position:0% +raising so I think there's a small range +of hands that you want to be making this + + align:start position:0% +of hands that you want to be making this + + + align:start position:0% +of hands that you want to be making this +on plays like I think that's basically + + align:start position:0% +on plays like I think that's basically + + + align:start position:0% +on plays like I think that's basically +exactly ace Queen off suit maybe Ace + + align:start position:0% +exactly ace Queen off suit maybe Ace + + + align:start position:0% +exactly ace Queen off suit maybe Ace +King maybe ace Queen Ace King and then + + align:start position:0% +King maybe ace Queen Ace King and then + + + align:start position:0% +King maybe ace Queen Ace King and then +like middle pairs let's say like between + + align:start position:0% +like middle pairs let's say like between + + + align:start position:0% +like middle pairs let's say like between +like pockets eights and pocket tennis or + + align:start position:0% +like pockets eights and pocket tennis or + + + align:start position:0% +like pockets eights and pocket tennis or +something so so like the only downside + + align:start position:0% +something so so like the only downside + + + align:start position:0% +something so so like the only downside +of this play I think is essentially his + + align:start position:0% +of this play I think is essentially his + + + align:start position:0% +of this play I think is essentially his +range here is very predictable it's + + align:start position:0% +range here is very predictable it's + + + align:start position:0% +range here is very predictable it's +gonna be like ace Jack suited plus ace + + align:start position:0% +gonna be like ace Jack suited plus ace + + + align:start position:0% +gonna be like ace Jack suited plus ace +queen and pocket eights three times or + + align:start position:0% +queen and pocket eights three times or + + + align:start position:0% +queen and pocket eights three times or +something like that so but nonetheless I + + align:start position:0% +something like that so but nonetheless I + + + align:start position:0% +something like that so but nonetheless I +mean I think because it's a final table + + align:start position:0% +mean I think because it's a final table + + + align:start position:0% +mean I think because it's a final table +because if I see em it's fine he + + align:start position:0% +because if I see em it's fine he + + + align:start position:0% +because if I see em it's fine he +gets unlucky nobody runs into Queens + + align:start position:0% +gets unlucky nobody runs into Queens + + + align:start position:0% +gets unlucky nobody runs into Queens +here + + align:start position:0% +here + + + align:start position:0% +here +we get a walk okay + + align:start position:0% + + + + align:start position:0% + +so let's see this hand so I show two + + align:start position:0% +so let's see this hand so I show two + + + align:start position:0% +so let's see this hand so I show two +raises goes all-in so we call here we're + + align:start position:0% +raises goes all-in so we call here we're + + + align:start position:0% +raises goes all-in so we call here we're +kind of deep where I want to give myself + + align:start position:0% +kind of deep where I want to give myself + + + align:start position:0% +kind of deep where I want to give myself +the opportunity to fold if ten pain + + align:start position:0% +the opportunity to fold if ten pain + + + align:start position:0% +the opportunity to fold if ten pain +Chrissy goes on and we + + align:start position:0% +Chrissy goes on and we + + + align:start position:0% +Chrissy goes on and we +call and he and we went so okay so I + + align:start position:0% +call and he and we went so okay so I + + + align:start position:0% +call and he and we went so okay so I +guess I've been running pretty good in + + align:start position:0% +guess I've been running pretty good in + + + align:start position:0% +guess I've been running pretty good in +this tournament there + + align:start position:0% +this tournament there + + + align:start position:0% +this tournament there +is a lot of selection bias here right + + align:start position:0% +is a lot of selection bias here right + + + align:start position:0% +is a lot of selection bias here right +because I'm gonna I'm not going to like + + align:start position:0% +because I'm gonna I'm not going to like + + + align:start position:0% +because I'm gonna I'm not going to like +place your tournament where I get all + + align:start position:0% +place your tournament where I get all + + + align:start position:0% +place your tournament where I get all +another standards right so I mean so + + align:start position:0% +another standards right so I mean so + + + align:start position:0% +another standards right so I mean so +it's in some sense not the best + + align:start position:0% +it's in some sense not the best + + + align:start position:0% +it's in some sense not the best +pedagogical example to use there is a + + align:start position:0% +pedagogical example to use there is a + + + align:start position:0% +pedagogical example to use there is a +lot of like selection bias you know that + + align:start position:0% +lot of like selection bias you know that + + + align:start position:0% +lot of like selection bias you know that +I'm gonna run very good in the + + align:start position:0% +I'm gonna run very good in the + + + align:start position:0% +I'm gonna run very good in the +tournament I choose to show you guys but + + align:start position:0% +tournament I choose to show you guys but + + + align:start position:0% +tournament I choose to show you guys but +I mean if it's between that and you know + + align:start position:0% +I mean if it's between that and you know + + + align:start position:0% +I mean if it's between that and you know +having the class be over five minutes is + + align:start position:0% +having the class be over five minutes is + + + align:start position:0% +having the class be over five minutes is +a classic this + + align:start position:0% +a classic this + + + align:start position:0% +a classic this +is this is the lesser of two evils all + + align:start position:0% + + + + align:start position:0% + +right so so here yeah so once again this + + align:start position:0% +right so so here yeah so once again this + + + align:start position:0% +right so so here yeah so once again this +isn't pretty it's not that big but it's + + align:start position:0% +isn't pretty it's not that big but it's + + + align:start position:0% +isn't pretty it's not that big but it's +a it's a 17 big blind shove and once + + align:start position:0% +a it's a 17 big blind shove and once + + + align:start position:0% +a it's a 17 big blind shove and once +again it's justified by ICM maybe fold + + align:start position:0% +again it's justified by ICM maybe fold + + + align:start position:0% +again it's justified by ICM maybe fold +get + + align:start position:0% + + + + align:start position:0% + +here Queen seven off yeah I shove I mean + + align:start position:0% +here Queen seven off yeah I shove I mean + + + align:start position:0% +here Queen seven off yeah I shove I mean +I think it's it's probably barely a pull + + align:start position:0% +I think it's it's probably barely a pull + + + align:start position:0% +I think it's it's probably barely a pull +I think it's pretty close it should be + + align:start position:0% +I think it's pretty close it should be + + + align:start position:0% +I think it's pretty close it should be +be equals money evey it would be a + + align:start position:0% +be equals money evey it would be a + + + align:start position:0% +be equals money evey it would be a +borderline show with these smallish + + align:start position:0% +borderline show with these smallish + + + align:start position:0% +borderline show with these smallish +entities but given ICM I know he's less + + align:start position:0% +entities but given ICM I know he's less + + + align:start position:0% +entities but given ICM I know he's less +incentivized to call than usual so all + + align:start position:0% +incentivized to call than usual so all + + + align:start position:0% +incentivized to call than usual so all +borderline hands I'm going to be shoving + + align:start position:0% +borderline hands I'm going to be shoving + + + align:start position:0% +borderline hands I'm going to be shoving +so I do okay + + align:start position:0% + + + + align:start position:0% + +so this hand we get King 10 so once + + align:start position:0% +so this hand we get King 10 so once + + + align:start position:0% +so this hand we get King 10 so once +again I just shove um well once again + + align:start position:0% +again I just shove um well once again + + + align:start position:0% +again I just shove um well once again +it's I think I basically + + align:start position:0% +it's I think I basically + + + align:start position:0% +it's I think I basically +it's hard for them to call if I just + + align:start position:0% +it's hard for them to call if I just + + + align:start position:0% +it's hard for them to call if I just +shoved and I am because if I see a so + + align:start position:0% +shoved and I am because if I see a so + + + align:start position:0% +shoved and I am because if I see a so +I'm essentially bullying him bullying + + align:start position:0% +I'm essentially bullying him bullying + + + align:start position:0% +I'm essentially bullying him bullying +them so when you're the big stack you + + align:start position:0% +them so when you're the big stack you + + + align:start position:0% +them so when you're the big stack you +can sort of bully people at the final + + align:start position:0% +can sort of bully people at the final + + + align:start position:0% +can sort of bully people at the final +table because because if I see him would + + align:start position:0% +table because because if I see him would + + + align:start position:0% +table because because if I see him would +you get it looked up here though and we + + align:start position:0% +you get it looked up here though and we + + + align:start position:0% +you get it looked up here though and we +have looked at by a say and so he he + + align:start position:0% +have looked at by a say and so he he + + + align:start position:0% +have looked at by a say and so he he +wins I think I'm + + align:start position:0% +wins I think I'm + + + align:start position:0% +wins I think I'm +not gonna do an exact calculation + + align:start position:0% +not gonna do an exact calculation + + + align:start position:0% +not gonna do an exact calculation +because I'm gonna do an exact ICM + + align:start position:0% +because I'm gonna do an exact ICM + + + align:start position:0% +because I'm gonna do an exact ICM +calculation later but I would guess his + + align:start position:0% +calculation later but I would guess his + + + align:start position:0% +calculation later but I would guess his +call I would guess his calls very + + align:start position:0% +call I would guess his calls very + + + align:start position:0% +call I would guess his calls very +borderline I mean it's definitely it's + + align:start position:0% +borderline I mean it's definitely it's + + + align:start position:0% +borderline I mean it's definitely it's +definitely positive ship expectancy but + + align:start position:0% +definitely positive ship expectancy but + + + align:start position:0% +definitely positive ship expectancy but +the fact that there's this guy 150 7,000 + + align:start position:0% +the fact that there's this guy 150 7,000 + + + align:start position:0% +the fact that there's this guy 150 7,000 +in this time of 70,000 I think I think + + align:start position:0% +in this time of 70,000 I think I think + + + align:start position:0% +in this time of 70,000 I think I think +it's a call but I think like a six is + + align:start position:0% +it's a call but I think like a six is + + + align:start position:0% +it's a call but I think like a six is +definitely full so I think it's probably + + align:start position:0% +definitely full so I think it's probably + + + align:start position:0% +definitely full so I think it's probably +one of the weakest hands you should be + + align:start position:0% +one of the weakest hands you should be + + + align:start position:0% +one of the weakest hands you should be +calling what I think a state is probably + + align:start position:0% +calling what I think a state is probably + + + align:start position:0% +calling what I think a state is probably +too good he has to call but I think it's + + align:start position:0% +too good he has to call but I think it's + + + align:start position:0% +too good he has to call but I think it's +very borderline in either case because + + align:start position:0% +very borderline in either case because + + + align:start position:0% +very borderline in either case because +if I see him so + + align:start position:0% +if I see him so + + + align:start position:0% +if I see him so +he does hold though so now so now I see + + align:start position:0% +he does hold though so now so now I see + + + align:start position:0% +he does hold though so now so now I see +em is a bit trickier because now we're + + align:start position:0% +em is a bit trickier because now we're + + + align:start position:0% +em is a bit trickier because now we're +smaller we're getting it all in with any + + align:start position:0% +smaller we're getting it all in with any + + + align:start position:0% +smaller we're getting it all in with any +of these guys can really damage us and + + align:start position:0% +of these guys can really damage us and + + + align:start position:0% +of these guys can really damage us and +there's still like two short stacks that + + align:start position:0% +there's still like two short stacks that + + + align:start position:0% +there's still like two short stacks that +were kind of everyone is hoping a little + + align:start position:0% +were kind of everyone is hoping a little + + + align:start position:0% +were kind of everyone is hoping a little +bust soon so + + align:start position:0% +bust soon so + + + align:start position:0% +bust soon so +you know so in this situation you know I + + align:start position:0% +you know so in this situation you know I + + + align:start position:0% +you know so in this situation you know I +could like go all in and believe this + + align:start position:0% +could like go all in and believe this + + + align:start position:0% +could like go all in and believe this +pimp accuracy guy but I see him isn't + + align:start position:0% +pimp accuracy guy but I see him isn't + + + align:start position:0% +pimp accuracy guy but I see him isn't +that relevant like I can't he's not + + align:start position:0% +that relevant like I can't he's not + + + align:start position:0% +that relevant like I can't he's not +gonna fold like East Queen if I go all + + align:start position:0% +gonna fold like East Queen if I go all + + + align:start position:0% +gonna fold like East Queen if I go all +in so I just give this one to them + + align:start position:0% +in so I just give this one to them + + + align:start position:0% +in so I just give this one to them +yeah like calling calling is probably + + align:start position:0% +yeah like calling calling is probably + + + align:start position:0% +yeah like calling calling is probably +bad anyway but calling I think is + + align:start position:0% +bad anyway but calling I think is + + + align:start position:0% +bad anyway but calling I think is +especially bad because it just increases + + align:start position:0% +especially bad because it just increases + + + align:start position:0% +especially bad because it just increases +the chances of lutely getting in a + + align:start position:0% +the chances of lutely getting in a + + + align:start position:0% +the chances of lutely getting in a +bigger pot okay + + align:start position:0% + + + + align:start position:0% + +well skip forward a bit let's see this + + align:start position:0% +well skip forward a bit let's see this + + + align:start position:0% +well skip forward a bit let's see this +hand so East + + align:start position:0% +hand so East + + + align:start position:0% +hand so East +10 okay so he's 10 off here so this guy + + align:start position:0% +10 okay so he's 10 off here so this guy + + + align:start position:0% +10 okay so he's 10 off here so this guy +makes it twelve thousand and I guess I + + align:start position:0% +makes it twelve thousand and I guess I + + + align:start position:0% +makes it twelve thousand and I guess I +just skipped a bunch of hands but so + + align:start position:0% +just skipped a bunch of hands but so + + + align:start position:0% +just skipped a bunch of hands but so +Nicholas Brody I think has been very + + align:start position:0% +Nicholas Brody I think has been very + + + align:start position:0% +Nicholas Brody I think has been very +active and overall I think people have + + align:start position:0% +active and overall I think people have + + + align:start position:0% +active and overall I think people have +become very active everyone's playing a + + align:start position:0% +become very active everyone's playing a + + + align:start position:0% +become very active everyone's playing a +lot of pots so overall I'm gonna put + + align:start position:0% +lot of pots so overall I'm gonna put + + + align:start position:0% +lot of pots so overall I'm gonna put +people on wider ranges than I normally + + align:start position:0% +people on wider ranges than I normally + + + align:start position:0% +people on wider ranges than I normally +do but nonetheless here I still full + + align:start position:0% +do but nonetheless here I still full + + + align:start position:0% +do but nonetheless here I still full +day's 10 I think it's I think it's East + + align:start position:0% +day's 10 I think it's I think it's East + + + align:start position:0% +day's 10 I think it's I think it's East +Jack I would probably get it in and each + + align:start position:0% +Jack I would probably get it in and each + + + align:start position:0% +Jack I would probably get it in and each +ten suited I think I would get it in + + align:start position:0% +ten suited I think I would get it in + + + align:start position:0% +ten suited I think I would get it in +it's ten suited is sort of borderline + + align:start position:0% +it's ten suited is sort of borderline + + + align:start position:0% +it's ten suited is sort of borderline +and once again you know once again + + align:start position:0% +and once again you know once again + + + align:start position:0% +and once again you know once again +whatever there's sort of when you're + + align:start position:0% +whatever there's sort of when you're + + + align:start position:0% +whatever there's sort of when you're +tied between getting in a smaller pot + + align:start position:0% +tied between getting in a smaller pot + + + align:start position:0% +tied between getting in a smaller pot +and getting in a bigger pot you kind of + + align:start position:0% +and getting in a bigger pot you kind of + + + align:start position:0% +and getting in a bigger pot you kind of +want to be you want to be folding so + + align:start position:0% +want to be you want to be folding so + + + align:start position:0% +want to be you want to be folding so +yeah so I guess in the final table I + + align:start position:0% +yeah so I guess in the final table I + + + align:start position:0% +yeah so I guess in the final table I +should make this clear it's not like you + + align:start position:0% +should make this clear it's not like you + + + align:start position:0% +should make this clear it's not like you +want to fold more it's sort of you want + + align:start position:0% +want to fold more it's sort of you want + + + align:start position:0% +want to fold more it's sort of you want +to go all-in more when you're first to + + align:start position:0% +to go all-in more when you're first to + + + align:start position:0% +to go all-in more when you're first to +act but call other people as all-in is + + align:start position:0% +act but call other people as all-in is + + + align:start position:0% +act but call other people as all-in is +less so that's exactly what's going on + + align:start position:0% +less so that's exactly what's going on + + + align:start position:0% +less so that's exactly what's going on +here he's already moved all in and I'm + + align:start position:0% +here he's already moved all in and I'm + + + align:start position:0% +here he's already moved all in and I'm +gonna fold to his all in more often then + + align:start position:0% +gonna fold to his all in more often then + + + align:start position:0% +gonna fold to his all in more often then +normal game but as you can see I'm I + + align:start position:0% +normal game but as you can see I'm I + + + align:start position:0% +normal game but as you can see I'm I +haven't really been tighter in every + + align:start position:0% +haven't really been tighter in every + + + align:start position:0% +haven't really been tighter in every +sense because when I have to go first + + align:start position:0% +sense because when I have to go first + + + align:start position:0% +sense because when I have to go first +I've been actually going all any more + + align:start position:0% +I've been actually going all any more + + + align:start position:0% +I've been actually going all any more +often and risking it more often because + + align:start position:0% +often and risking it more often because + + + align:start position:0% +often and risking it more often because +I know my opponents are highly + + align:start position:0% +I know my opponents are highly + + + align:start position:0% +I know my opponents are highly +incentivized people so anyway so it's so + + align:start position:0% +incentivized people so anyway so it's so + + + align:start position:0% +incentivized people so anyway so it's so +they go on and I fold here so Nicholas + + align:start position:0% +they go on and I fold here so Nicholas + + + align:start position:0% +they go on and I fold here so Nicholas +Brody also folds which I guess is fine + + align:start position:0% +Brody also folds which I guess is fine + + + align:start position:0% +Brody also folds which I guess is fine +but it's it's definitely a pretty good + + align:start position:0% +but it's it's definitely a pretty good + + + align:start position:0% +but it's it's definitely a pretty good +Odyssey call there but + + align:start position:0% + + + + align:start position:0% + +once again yeah like I see em just makes + + align:start position:0% +once again yeah like I see em just makes + + + align:start position:0% +once again yeah like I see em just makes +it changes things up a bit Jack 7 suited + + align:start position:0% +it changes things up a bit Jack 7 suited + + + align:start position:0% +it changes things up a bit Jack 7 suited +once again it's a pretty big shove but + + align:start position:0% +once again it's a pretty big shove but + + + align:start position:0% +once again it's a pretty big shove but +Jack sevens you did plenty good enough + + align:start position:0% +Jack sevens you did plenty good enough + + + align:start position:0% +Jack sevens you did plenty good enough +it I see em relevant pocket + + align:start position:0% +it I see em relevant pocket + + + align:start position:0% +it I see em relevant pocket +nines here we make it twelve thousand on + + align:start position:0% +nines here we make it twelve thousand on + + + align:start position:0% +nines here we make it twelve thousand on +the on the button so here I think pocket + + align:start position:0% +the on the button so here I think pocket + + + align:start position:0% +the on the button so here I think pocket +nines is sort of good enough where I'm + + align:start position:0% +nines is sort of good enough where I'm + + + align:start position:0% +nines is sort of good enough where I'm +happy at one of them three bases all in + + align:start position:0% +happy at one of them three bases all in + + + align:start position:0% +happy at one of them three bases all in +there I call so essentially my strategy + + align:start position:0% +there I call so essentially my strategy + + + align:start position:0% +there I call so essentially my strategy +here is I'm going to show like all my + + align:start position:0% +here is I'm going to show like all my + + + align:start position:0% +here is I'm going to show like all my +sort of medium strength hands and + + align:start position:0% +sort of medium strength hands and + + + align:start position:0% +sort of medium strength hands and +especially hands that don't play well + + align:start position:0% +especially hands that don't play well + + + align:start position:0% +especially hands that don't play well +post off like east to offsuit and then + + align:start position:0% +post off like east to offsuit and then + + + align:start position:0% +post off like east to offsuit and then +I'm gonna raise small with some of my + + align:start position:0% +I'm gonna raise small with some of my + + + align:start position:0% +I'm gonna raise small with some of my +hands + + align:start position:0% +hands + + + align:start position:0% +hands +that are less good preflop the better + + align:start position:0% +that are less good preflop the better + + + align:start position:0% +that are less good preflop the better +post flop let's say like ten eight + + align:start position:0% +post flop let's say like ten eight + + + align:start position:0% +post flop let's say like ten eight +suited and also my monster hands like + + align:start position:0% +suited and also my monster hands like + + + align:start position:0% +suited and also my monster hands like +pocket nines that are also reasonable to + + align:start position:0% +pocket nines that are also reasonable to + + + align:start position:0% +pocket nines that are also reasonable to +play post flop so so + + align:start position:0% +play post flop so so + + + align:start position:0% +play post flop so so +Nicolas nobody calls here and the flop + + align:start position:0% +Nicolas nobody calls here and the flop + + + align:start position:0% +Nicolas nobody calls here and the flop +is East Jack seven with regards so it's + + align:start position:0% +is East Jack seven with regards so it's + + + align:start position:0% +is East Jack seven with regards so it's +a bad fall for a hand but it's a good + + align:start position:0% +a bad fall for a hand but it's a good + + + align:start position:0% +a bad fall for a hand but it's a good +flop for our range because + + align:start position:0% +flop for our range because + + + align:start position:0% +flop for our range because +I I think given the way the table was + + align:start position:0% +I I think given the way the table was + + + align:start position:0% +I I think given the way the table was +going I was opening a lot and Nicholas + + align:start position:0% +going I was opening a lot and Nicholas + + + align:start position:0% +going I was opening a lot and Nicholas +Brody is very aggressive I would guess + + align:start position:0% +Brody is very aggressive I would guess + + + align:start position:0% +Brody is very aggressive I would guess +unless he had like pocket he says where + + align:start position:0% +unless he had like pocket he says where + + + align:start position:0% +unless he had like pocket he says where +she might slow play he would rebase most + + align:start position:0% +she might slow play he would rebase most + + + align:start position:0% +she might slow play he would rebase most +I was I wasn't like a hundred percent + + align:start position:0% +I was I wasn't like a hundred percent + + + align:start position:0% +I was I wasn't like a hundred percent +sure confident but I was reasonably I'd + + align:start position:0% +sure confident but I was reasonably I'd + + + align:start position:0% +sure confident but I was reasonably I'd +say like maybe eighty-five percent + + align:start position:0% +say like maybe eighty-five percent + + + align:start position:0% +say like maybe eighty-five percent +confident that if he had an ace preflop + + align:start position:0% +confident that if he had an ace preflop + + + align:start position:0% +confident that if he had an ace preflop +he would have just went all-in pretty + + align:start position:0% +he would have just went all-in pretty + + + align:start position:0% +he would have just went all-in pretty +flop so overall I still say it's a very + + align:start position:0% +flop so overall I still say it's a very + + + align:start position:0% +flop so overall I still say it's a very +good flop for my range cuz I think he's + + align:start position:0% +good flop for my range cuz I think he's + + + align:start position:0% +good flop for my range cuz I think he's +way less likely to have an ace to me + + align:start position:0% +way less likely to have an ace to me + + + align:start position:0% +way less likely to have an ace to me +there's a small chance maybe he he would + + align:start position:0% +there's a small chance maybe he he would + + + align:start position:0% +there's a small chance maybe he he would +chicken out with like east to officers + + align:start position:0% +chicken out with like east to officers + + + align:start position:0% +chicken out with like east to officers +and just call but I but given how + + align:start position:0% +and just call but I but given how + + + align:start position:0% +and just call but I but given how +aggressive he's been I would be + + align:start position:0% +aggressive he's been I would be + + + align:start position:0% +aggressive he's been I would be +surprised if he did that so so I decided + + align:start position:0% +surprised if he did that so so I decided + + + align:start position:0% +surprised if he did that so so I decided +you've been here and I'm still not sure + + align:start position:0% +you've been here and I'm still not sure + + + align:start position:0% +you've been here and I'm still not sure +how good this bed is so I think at the + + align:start position:0% +how good this bed is so I think at the + + + align:start position:0% +how good this bed is so I think at the +time that because of my logic that he + + align:start position:0% +time that because of my logic that he + + + align:start position:0% +time that because of my logic that he +can't it's really hard forever you have + + align:start position:0% +can't it's really hard forever you have + + + align:start position:0% +can't it's really hard forever you have +a nice and so I think the best strategy + + align:start position:0% +a nice and so I think the best strategy + + + align:start position:0% +a nice and so I think the best strategy +for me on this flop and in this + + align:start position:0% +for me on this flop and in this + + + align:start position:0% +for me on this flop and in this +situation is just been a hundred percent + + align:start position:0% +situation is just been a hundred percent + + + align:start position:0% +situation is just been a hundred percent +of my hands and he's kind of just forced + + align:start position:0% +of my hands and he's kind of just forced + + + align:start position:0% +of my hands and he's kind of just forced +to fold basically very often because she + + align:start position:0% +to fold basically very often because she + + + align:start position:0% +to fold basically very often because she +can't really keep up with an a second + + align:start position:0% +can't really keep up with an a second + + + align:start position:0% +can't really keep up with an a second +discontinue betting that being said + + align:start position:0% +discontinue betting that being said + + + align:start position:0% +discontinue betting that being said +though I do think you know if I do + + align:start position:0% +though I do think you know if I do + + + align:start position:0% +though I do think you know if I do +decide as part of my strategy to check + + align:start position:0% +decide as part of my strategy to check + + + align:start position:0% +decide as part of my strategy to check +any part of my range here party lines + + align:start position:0% +any part of my range here party lines + + + align:start position:0% +any part of my range here party lines +and light actually be one of the best + + align:start position:0% +and light actually be one of the best + + + align:start position:0% +and light actually be one of the best +possible hands to check back so I think + + align:start position:0% +possible hands to check back so I think + + + align:start position:0% +possible hands to check back so I think +checking back would have been fine I + + align:start position:0% +checking back would have been fine I + + + align:start position:0% +checking back would have been fine I +guess I've been here because I told + + align:start position:0% +guess I've been here because I told + + + align:start position:0% +guess I've been here because I told +myself I want my strategy to be bet a + + align:start position:0% +myself I want my strategy to be bet a + + + align:start position:0% +myself I want my strategy to be bet a +hundred percent of my hands which I did + + align:start position:0% +hundred percent of my hands which I did + + + align:start position:0% +hundred percent of my hands which I did +and he fold which + + align:start position:0% +and he fold which + + + align:start position:0% +and he fold which +is yet which is reasonably smart because + + align:start position:0% +is yet which is reasonably smart because + + + align:start position:0% +is yet which is reasonably smart because +he knows that you know I can bet again + + align:start position:0% +he knows that you know I can bet again + + + align:start position:0% +he knows that you know I can bet again +and he's gonna have to make a decision + + align:start position:0% +and he's gonna have to make a decision + + + align:start position:0% +and he's gonna have to make a decision +for all his chips probably and it's just + + align:start position:0% +for all his chips probably and it's just + + + align:start position:0% +for all his chips probably and it's just +gonna be tough okay + + align:start position:0% + + + + align:start position:0% + +this hand be my sponsor goes all-in gets + + align:start position:0% +this hand be my sponsor goes all-in gets + + + align:start position:0% +this hand be my sponsor goes all-in gets +the vines oh yeah + + align:start position:0% + + + + align:start position:0% + +sorry why why don't you say oh + + align:start position:0% + + + + align:start position:0% + +um I think it's basically it's the I + + align:start position:0% +um I think it's basically it's the I + + + align:start position:0% +um I think it's basically it's the I +think I very rarely get called by worse + + align:start position:0% +think I very rarely get called by worse + + + align:start position:0% +think I very rarely get called by worse +and I get called by everything better + + align:start position:0% +and I get called by everything better + + + align:start position:0% +and I get called by everything better +like I think she's always calling a jack + + align:start position:0% +like I think she's always calling a jack + + + align:start position:0% +like I think she's always calling a jack +and usually folding a seven like maybe + + align:start position:0% +and usually folding a seven like maybe + + + align:start position:0% +and usually folding a seven like maybe +he won't fold seven eight with some back + + align:start position:0% +he won't fold seven eight with some back + + + align:start position:0% +he won't fold seven eight with some back +door drums but I think he'll usually + + align:start position:0% +door drums but I think he'll usually + + + align:start position:0% +door drums but I think he'll usually +call a jacket maybe they'll call seven + + align:start position:0% +call a jacket maybe they'll call seven + + + align:start position:0% +call a jacket maybe they'll call seven +sometimes but I still think mostly it's + + align:start position:0% +sometimes but I still think mostly it's + + + align:start position:0% +sometimes but I still think mostly it's +just he'll basically fold everything + + align:start position:0% +just he'll basically fold everything + + + align:start position:0% +just he'll basically fold everything +that beats me and call everything that + + align:start position:0% +that beats me and call everything that + + + align:start position:0% +that beats me and call everything that +it's just sorry he'll fold everything + + align:start position:0% +it's just sorry he'll fold everything + + + align:start position:0% +it's just sorry he'll fold everything +that I beat and call everything that + + align:start position:0% +that I beat and call everything that + + + align:start position:0% +that I beat and call everything that +needs me basically yeah + + align:start position:0% + + + + align:start position:0% + +but I saw the side to bed nonetheless + + align:start position:0% +but I saw the side to bed nonetheless + + + align:start position:0% +but I saw the side to bed nonetheless +just to win the pot there and not give + + align:start position:0% +just to win the pot there and not give + + + align:start position:0% +just to win the pot there and not give +him extra outs if he happens you have + + align:start position:0% +him extra outs if he happens you have + + + align:start position:0% +him extra outs if he happens you have +like ten or something so + + align:start position:0% + + + + align:start position:0% + +okay so we'll go through this hand so + + align:start position:0% +okay so we'll go through this hand so + + + align:start position:0% +okay so we'll go through this hand so +I'm Hank receive raises he doesn't go + + align:start position:0% +I'm Hank receive raises he doesn't go + + + align:start position:0% +I'm Hank receive raises he doesn't go +all-in which is kind of curious but um + + align:start position:0% +all-in which is kind of curious but um + + + align:start position:0% +all-in which is kind of curious but um +LP box calls he calls again it's checked + + align:start position:0% +LP box calls he calls again it's checked + + + align:start position:0% +LP box calls he calls again it's checked +and then LP Marx goes all-in on the + + align:start position:0% +and then LP Marx goes all-in on the + + + align:start position:0% +and then LP Marx goes all-in on the +river gym sit down + + align:start position:0% + + + + align:start position:0% + +can you Jack stuff in here yes I guess + + align:start position:0% +can you Jack stuff in here yes I guess + + + align:start position:0% +can you Jack stuff in here yes I guess +so once again Nicholas Brady braces and + + align:start position:0% +so once again Nicholas Brady braces and + + + align:start position:0% +so once again Nicholas Brady braces and +then LT marks goes on over him wins + + align:start position:0% +then LT marks goes on over him wins + + + align:start position:0% +then LT marks goes on over him wins +a big pot so + + align:start position:0% + + + + align:start position:0% + +I guess I do the same for Nicholas Brady + + align:start position:0% +I guess I do the same for Nicholas Brady + + + align:start position:0% +I guess I do the same for Nicholas Brady +he's been he's been grazing a lot so + + align:start position:0% +he's been he's been grazing a lot so + + + align:start position:0% +he's been he's been grazing a lot so +pocket sixes definitely good enough to + + align:start position:0% +pocket sixes definitely good enough to + + + align:start position:0% +pocket sixes definitely good enough to +risk going all in there okay + + align:start position:0% + + + + align:start position:0% + +this hand if so we get ace Jack suited + + align:start position:0% +this hand if so we get ace Jack suited + + + align:start position:0% +this hand if so we get ace Jack suited +and I raised from cut off so + + align:start position:0% +and I raised from cut off so + + + align:start position:0% +and I raised from cut off so +I've been raising fairly to a fairly + + align:start position:0% +I've been raising fairly to a fairly + + + align:start position:0% +I've been raising fairly to a fairly +small size because the antes are smaller + + align:start position:0% +small size because the antes are smaller + + + align:start position:0% +small size because the antes are smaller +so that's one thing to remember at a + + align:start position:0% +so that's one thing to remember at a + + + align:start position:0% +so that's one thing to remember at a +final table is the pots are actually a + + align:start position:0% +final table is the pots are actually a + + + align:start position:0% +final table is the pots are actually a +bit smaller because with only five + + align:start position:0% +bit smaller because with only five + + + align:start position:0% +bit smaller because with only five +players the ante the ante the some of + + align:start position:0% +players the ante the ante the some of + + + align:start position:0% +players the ante the ante the some of +the antes instead of normally being six + + align:start position:0% +the antes instead of normally being six + + + align:start position:0% +the antes instead of normally being six +thousand is only three thousand in this + + align:start position:0% +thousand is only three thousand in this + + + align:start position:0% +thousand is only three thousand in this +case so the big blind has a response to + + align:start position:0% +case so the big blind has a response to + + + align:start position:0% +case so the big blind has a response to +call so + + align:start position:0% +call so + + + align:start position:0% +call so +Nicholas Brody goes all-in I look them + + align:start position:0% +Nicholas Brody goes all-in I look them + + + align:start position:0% +Nicholas Brody goes all-in I look them +up with ace Jack suited definitely good + + align:start position:0% +up with ace Jack suited definitely good + + + align:start position:0% +up with ace Jack suited definitely good +enough I mean also at this point is + + align:start position:0% +enough I mean also at this point is + + + align:start position:0% +enough I mean also at this point is +because a number of pots have gotten my + + align:start position:0% +because a number of pots have gotten my + + + align:start position:0% +because a number of pots have gotten my +way I'm sort of big enough where even if + + align:start position:0% +way I'm sort of big enough where even if + + + align:start position:0% +way I'm sort of big enough where even if +I call and lose this I'm still I won't + + align:start position:0% +I call and lose this I'm still I won't + + + align:start position:0% +I call and lose this I'm still I won't +be chip leader but I'll still have a + + align:start position:0% +be chip leader but I'll still have a + + + align:start position:0% +be chip leader but I'll still have a +decent amount of chips so + + align:start position:0% +decent amount of chips so + + + align:start position:0% +decent amount of chips so +unfortunately we lose the AC here so now + + align:start position:0% +unfortunately we lose the AC here so now + + + align:start position:0% +unfortunately we lose the AC here so now +we're a second place but we're still + + align:start position:0% +we're a second place but we're still + + + align:start position:0% +we're a second place but we're still +doing reasonably well yeah + + align:start position:0% + + + + align:start position:0% + +so you know like I could have I could + + align:start position:0% +so you know like I could have I could + + + align:start position:0% +so you know like I could have I could +have just maybe gone all in here I mean + + align:start position:0% +have just maybe gone all in here I mean + + + align:start position:0% +have just maybe gone all in here I mean +I guess this guy has a lot of chips but + + align:start position:0% +I guess this guy has a lot of chips but + + + align:start position:0% +I guess this guy has a lot of chips but +I could have like raised to a bigger + + align:start position:0% +I could have like raised to a bigger + + + align:start position:0% +I could have like raised to a bigger +size you disincentivize nicolas from me + + align:start position:0% +size you disincentivize nicolas from me + + + align:start position:0% +size you disincentivize nicolas from me +from doing this with the right wide + + align:start position:0% +from doing this with the right wide + + + align:start position:0% +from doing this with the right wide +range of hands and then sort of like + + align:start position:0% +range of hands and then sort of like + + + align:start position:0% +range of hands and then sort of like +protecting my stack more from an ICM + + align:start position:0% +protecting my stack more from an ICM + + + align:start position:0% +protecting my stack more from an ICM +point of view but I mean I'm happy with + + align:start position:0% +point of view but I mean I'm happy with + + + align:start position:0% +point of view but I mean I'm happy with +I think ace Jack suited is just good + + align:start position:0% +I think ace Jack suited is just good + + + align:start position:0% +I think ace Jack suited is just good +enough where I'm happy calling his his + + align:start position:0% +enough where I'm happy calling his his + + + align:start position:0% +enough where I'm happy calling his his +all in which I should have been in this + + align:start position:0% +all in which I should have been in this + + + align:start position:0% +all in which I should have been in this +case I guess yet he sings but yeah okay + + align:start position:0% + + + + align:start position:0% + +so Jack ten suited here so yeah here I + + align:start position:0% +so Jack ten suited here so yeah here I + + + align:start position:0% +so Jack ten suited here so yeah here I +just decided to fold weak I mean we + + align:start position:0% +just decided to fold weak I mean we + + + align:start position:0% +just decided to fold weak I mean we +could consider doing a crazy Bluff + + align:start position:0% +could consider doing a crazy Bluff + + + align:start position:0% +could consider doing a crazy Bluff +all-in but I don't think this guy's + + align:start position:0% +all-in but I don't think this guy's + + + align:start position:0% +all-in but I don't think this guy's +folding that often they made a rather + + align:start position:0% +folding that often they made a rather + + + align:start position:0% +folding that often they made a rather +big rebase + + align:start position:0% +big rebase + + + align:start position:0% +big rebase +preflop from going three times the + + align:start position:0% +preflop from going three times the + + + align:start position:0% +preflop from going three times the +initial opening so Nicholas Brody goes + + align:start position:0% +initial opening so Nicholas Brody goes + + + align:start position:0% +initial opening so Nicholas Brody goes +on here and they beautiful so Nicholas + + align:start position:0% +on here and they beautiful so Nicholas + + + align:start position:0% +on here and they beautiful so Nicholas +Brody you picking up a bunch of chips so + + align:start position:0% + + + + align:start position:0% + +he just takes it down again he's been + + align:start position:0% +he just takes it down again he's been + + + align:start position:0% +he just takes it down again he's been +raising quite a lot so + + align:start position:0% + + + + align:start position:0% + +again a raise and a call so ok lol p.m. + + align:start position:0% +again a raise and a call so ok lol p.m. + + + align:start position:0% +again a raise and a call so ok lol p.m. +box has been raising over to other + + align:start position:0% +box has been raising over to other + + + align:start position:0% +box has been raising over to other +people's Oh + + align:start position:0% +people's Oh + + + align:start position:0% +people's Oh +opens quite a lot so he gets called here + + align:start position:0% +opens quite a lot so he gets called here + + + align:start position:0% +opens quite a lot so he gets called here +but he holds and wins which is + + align:start position:0% +but he holds and wins which is + + + align:start position:0% +but he holds and wins which is +definitely bad news for everyone like + + align:start position:0% +definitely bad news for everyone like + + + align:start position:0% +definitely bad news for everyone like +you know if I could have if I would pay + + align:start position:0% +you know if I could have if I would pay + + + align:start position:0% +you know if I could have if I would pay +ten thousand chips into the pot you have + + align:start position:0% +ten thousand chips into the pot you have + + + align:start position:0% +ten thousand chips into the pot you have +this all and build the other way it + + align:start position:0% +this all and build the other way it + + + align:start position:0% +this all and build the other way it +almost certainly would be profitable + + align:start position:0% +almost certainly would be profitable + + + align:start position:0% +almost certainly would be profitable +like the amount I should be willing to + + align:start position:0% +like the amount I should be willing to + + + align:start position:0% +like the amount I should be willing to +pay to make this all and build the other + + align:start position:0% +pay to make this all and build the other + + + align:start position:0% +pay to make this all and build the other +way is probably like twenty five + + align:start position:0% +way is probably like twenty five + + + align:start position:0% +way is probably like twenty five +thousand like it's a ridiculous enough + + align:start position:0% +thousand like it's a ridiculous enough + + + align:start position:0% +thousand like it's a ridiculous enough +because the just the value of having + + align:start position:0% +because the just the value of having + + + align:start position:0% +because the just the value of having +people bust and moving up the payouts is + + align:start position:0% +people bust and moving up the payouts is + + + align:start position:0% +people bust and moving up the payouts is +so significant especially when I'm not + + align:start position:0% +so significant especially when I'm not + + + align:start position:0% +so significant especially when I'm not +such a big stack anymore okay + + align:start position:0% + + + + align:start position:0% + +so now this guy he just doubled up so + + align:start position:0% +so now this guy he just doubled up so + + + align:start position:0% +so now this guy he just doubled up so +yeah so forth so I guess that we were + + align:start position:0% +yeah so forth so I guess that we were + + + align:start position:0% +yeah so forth so I guess that we were +running pretty good but I say in the + + align:start position:0% +running pretty good but I say in the + + + align:start position:0% +running pretty good but I say in the +last two or three orbits as you can seen + + align:start position:0% +last two or three orbits as you can seen + + + align:start position:0% +last two or three orbits as you can seen +a lot of things haven't been that + + align:start position:0% +a lot of things haven't been that + + + align:start position:0% +a lot of things haven't been that +favorable we've lost some all ends and + + align:start position:0% +favorable we've lost some all ends and + + + align:start position:0% +favorable we've lost some all ends and +also people haven't really busted the + + align:start position:0% +also people haven't really busted the + + + align:start position:0% +also people haven't really busted the +chips are sort of just being passed + + align:start position:0% +chips are sort of just being passed + + + align:start position:0% +chips are sort of just being passed +around the table which is basically not + + align:start position:0% +around the table which is basically not + + + align:start position:0% +around the table which is basically not +what you're hoping for so + + align:start position:0% + + + + align:start position:0% + +king 10 off suit we got to walk we + + align:start position:0% +king 10 off suit we got to walk we + + + align:start position:0% +king 10 off suit we got to walk we +actually go there so walk just means + + align:start position:0% +actually go there so walk just means + + + align:start position:0% +actually go there so walk just means +everyone folds to do in the big blind I + + align:start position:0% +everyone folds to do in the big blind I + + + align:start position:0% +everyone folds to do in the big blind I +think we've actually gotten quite a lot + + align:start position:0% +think we've actually gotten quite a lot + + + align:start position:0% +think we've actually gotten quite a lot +of walks at this final table so + + align:start position:0% +of walks at this final table so + + + align:start position:0% +of walks at this final table so +something we can keep in mind if we're + + align:start position:0% +something we can keep in mind if we're + + + align:start position:0% +something we can keep in mind if we're +trying to play exploitative Lee later + + align:start position:0% +trying to play exploitative Lee later + + + align:start position:0% +trying to play exploitative Lee later +Queen Jack go all in few folds so at + + align:start position:0% + + + + align:start position:0% + +8/7 I guess LPL p.m. box after winning + + align:start position:0% +8/7 I guess LPL p.m. box after winning + + + align:start position:0% +8/7 I guess LPL p.m. box after winning +that so as I sort of noticed the big + + align:start position:0% +that so as I sort of noticed the big + + + align:start position:0% +that so as I sort of noticed the big +stacks are sort of the ones who win most + + align:start position:0% +stacks are sort of the ones who win most + + + align:start position:0% +stacks are sort of the ones who win most +of the pots and this is sort of expected + + align:start position:0% +of the pots and this is sort of expected + + + align:start position:0% +of the pots and this is sort of expected +so whenever I see em is relevant you + + align:start position:0% +so whenever I see em is relevant you + + + align:start position:0% +so whenever I see em is relevant you +would expect that so although the small + + align:start position:0% +would expect that so although the small + + + align:start position:0% +would expect that so although the small +stacks have a hired chef EB then so I + + align:start position:0% +stacks have a hired chef EB then so I + + + align:start position:0% +stacks have a hired chef EB then so I +have a higher money eg than chef EB + + align:start position:0% +have a higher money eg than chef EB + + + align:start position:0% +have a higher money eg than chef EB +usually this the ships get transferred + + align:start position:0% +usually this the ships get transferred + + + align:start position:0% +usually this the ships get transferred +from the small stacks to the big stacks + + align:start position:0% +from the small stacks to the big stacks + + + align:start position:0% +from the small stacks to the big stacks +because the big stacks have more since + + align:start position:0% +because the big stacks have more since + + + align:start position:0% +because the big stacks have more since +to you know go all in first and sort of + + align:start position:0% +to you know go all in first and sort of + + + align:start position:0% +to you know go all in first and sort of +bully people around so + + align:start position:0% +bully people around so + + + align:start position:0% +bully people around so +he takes this one down next + + align:start position:0% + + + + align:start position:0% + +time we get jacks here so pimp and + + align:start position:0% +time we get jacks here so pimp and + + + align:start position:0% +time we get jacks here so pimp and +Christy is actually kind of short now + + align:start position:0% +Christy is actually kind of short now + + + align:start position:0% +Christy is actually kind of short now +even though he started the final table + + align:start position:0% +even though he started the final table + + + align:start position:0% +even though he started the final table +as the chick later because he's lost a + + align:start position:0% +as the chick later because he's lost a + + + align:start position:0% +as the chick later because he's lost a +bunch of all ins he gets it all in here + + align:start position:0% +bunch of all ins he gets it all in here + + + align:start position:0% +bunch of all ins he gets it all in here +and we hold we hold against a six so + + align:start position:0% +and we hold we hold against a six so + + + align:start position:0% +and we hold we hold against a six so +there's actually an interesting play + + align:start position:0% +there's actually an interesting play + + + align:start position:0% +there's actually an interesting play +here I I don't think he should have done + + align:start position:0% +here I I don't think he should have done + + + align:start position:0% +here I I don't think he should have done +it but this is actually often a good ICM + + align:start position:0% +it but this is actually often a good ICM + + + align:start position:0% +it but this is actually often a good ICM +play so normally I would say in this + + align:start position:0% +play so normally I would say in this + + + align:start position:0% +play so normally I would say in this +situation if you have a good hand just + + align:start position:0% +situation if you have a good hand just + + + align:start position:0% +situation if you have a good hand just +go all-in because he knows I'm gonna + + align:start position:0% +go all-in because he knows I'm gonna + + + align:start position:0% +go all-in because he knows I'm gonna +call so with a sixty just went all-in + + align:start position:0% +call so with a sixty just went all-in + + + align:start position:0% +call so with a sixty just went all-in +but often um there's this play called + + align:start position:0% +but often um there's this play called + + + align:start position:0% +but often um there's this play called +the stop-and-go which is in fact it's + + align:start position:0% +the stop-and-go which is in fact it's + + + align:start position:0% +the stop-and-go which is in fact it's +not very good like I don't think it + + align:start position:0% +not very good like I don't think it + + + align:start position:0% +not very good like I don't think it +would have been here but it's an + + align:start position:0% +would have been here but it's an + + + align:start position:0% +would have been here but it's an +interesting theoretical concept which is + + align:start position:0% +interesting theoretical concept which is + + + align:start position:0% +interesting theoretical concept which is +instead of going on he just called okay + + align:start position:0% +instead of going on he just called okay + + + align:start position:0% +instead of going on he just called okay +he calls and then he basically blindly + + align:start position:0% +he calls and then he basically blindly + + + align:start position:0% +he calls and then he basically blindly +goes all-in on the flop like he I mean + + align:start position:0% +goes all-in on the flop like he I mean + + + align:start position:0% +goes all-in on the flop like he I mean +she doesn't actually have to but this is + + align:start position:0% +she doesn't actually have to but this is + + + align:start position:0% +she doesn't actually have to but this is +what players used to do and you can do + + align:start position:0% +what players used to do and you can do + + + align:start position:0% +what players used to do and you can do +this in live poker what you would do in + + align:start position:0% +this in live poker what you would do in + + + align:start position:0% +this in live poker what you would do in +this situation is you would say call and + + align:start position:0% +this situation is you would say call and + + + align:start position:0% +this situation is you would say call and +then before the dealer even deals the + + align:start position:0% +then before the dealer even deals the + + + align:start position:0% +then before the dealer even deals the +floppy would you say all-in and this is + + align:start position:0% +floppy would you say all-in and this is + + + align:start position:0% +floppy would you say all-in and this is +a legal play and is + + align:start position:0% +a legal play and is + + + align:start position:0% +a legal play and is +essentially to the point is essentially + + align:start position:0% +essentially to the point is essentially + + + align:start position:0% +essentially to the point is essentially +it's an ICM they'll be the justification + + align:start position:0% +it's an ICM they'll be the justification + + + align:start position:0% +it's an ICM they'll be the justification +which i think is mostly wrong but still + + align:start position:0% +which i think is mostly wrong but still + + + align:start position:0% +which i think is mostly wrong but still +interesting is he + + align:start position:0% +interesting is he + + + align:start position:0% +interesting is he +sort of wants to maximize the chances + + align:start position:0% +sort of wants to maximize the chances + + + align:start position:0% +sort of wants to maximize the chances +that I fold so essentially okay this is + + align:start position:0% +that I fold so essentially okay this is + + + align:start position:0% +that I fold so essentially okay this is +strictly better right sorry the fact + + align:start position:0% +strictly better right sorry the fact + + + align:start position:0% +strictly better right sorry the fact +that the fact that he would call let me + + align:start position:0% +that the fact that he would call let me + + + align:start position:0% +that the fact that he would call let me +see the flop and then I get to decide + + align:start position:0% +see the flop and then I get to decide + + + align:start position:0% +see the flop and then I get to decide +whether to put the remaining chips in + + align:start position:0% +whether to put the remaining chips in + + + align:start position:0% +whether to put the remaining chips in +sounds like it should be better for me + + align:start position:0% +sounds like it should be better for me + + + align:start position:0% +sounds like it should be better for me +than me having to put all the chips in + + align:start position:0% +than me having to put all the chips in + + + align:start position:0% +than me having to put all the chips in +preflop but the main reason why he does + + align:start position:0% +preflop but the main reason why he does + + + align:start position:0% +preflop but the main reason why he does +this is because he doesn't he wants me + + align:start position:0% +this is because he doesn't he wants me + + + align:start position:0% +this is because he doesn't he wants me +to have an opportunity to fold my cards + + align:start position:0% +to have an opportunity to fold my cards + + + align:start position:0% +to have an opportunity to fold my cards +and avoid getting in a situation where + + align:start position:0% +and avoid getting in a situation where + + + align:start position:0% +and avoid getting in a situation where +both of us are playing for all our + + align:start position:0% +both of us are playing for all our + + + align:start position:0% +both of us are playing for all our +entire stack so this was sort of the + + align:start position:0% +entire stack so this was sort of the + + + align:start position:0% +entire stack so this was sort of the +justification for it so even though + + align:start position:0% +justification for it so even though + + + align:start position:0% +justification for it so even though +you're you're giving your opponent more + + align:start position:0% +you're you're giving your opponent more + + + align:start position:0% +you're you're giving your opponent more +information you're also decreasing the + + align:start position:0% +information you're also decreasing the + + + align:start position:0% +information you're also decreasing the +chances that they decide to call to the + + align:start position:0% +chances that they decide to call to the + + + align:start position:0% +chances that they decide to call to the +river card and have more chances of + + align:start position:0% +river card and have more chances of + + + align:start position:0% +river card and have more chances of +beating you so I mean that justification + + align:start position:0% +beating you so I mean that justification + + + align:start position:0% +beating you so I mean that justification +is correct but it's just that if you + + align:start position:0% +is correct but it's just that if you + + + align:start position:0% +is correct but it's just that if you +crunch the numbers usually this + + align:start position:0% +crunch the numbers usually this + + + align:start position:0% +crunch the numbers usually this +situation won't be favorable enough and + + align:start position:0% +situation won't be favorable enough and + + + align:start position:0% +situation won't be favorable enough and +usually don't want to be giving your + + align:start position:0% +usually don't want to be giving your + + + align:start position:0% +usually don't want to be giving your +opponent that extra information okay + + align:start position:0% +opponent that extra information okay + + + align:start position:0% +opponent that extra information okay +so so finally someone busts we + + align:start position:0% + + + + align:start position:0% + +get Jackson off again so he normally I + + align:start position:0% +get Jackson off again so he normally I + + + align:start position:0% +get Jackson off again so he normally I +think I would often consider calling + + align:start position:0% +think I would often consider calling + + + align:start position:0% +think I would often consider calling +this but I think just a voice so now + + align:start position:0% +this but I think just a voice so now + + + align:start position:0% +this but I think just a voice so now +this extra sort of even before the chip + + align:start position:0% +this extra sort of even before the chip + + + align:start position:0% +this extra sort of even before the chip +leader but not by a time and I don't + + align:start position:0% +leader but not by a time and I don't + + + align:start position:0% +leader but not by a time and I don't +really want to get in a big pot here so + + align:start position:0% +really want to get in a big pot here so + + + align:start position:0% +really want to get in a big pot here so +I decided to just give it to him even + + align:start position:0% +I decided to just give it to him even + + + align:start position:0% +I decided to just give it to him even +though normally I would definitely call + + align:start position:0% +though normally I would definitely call + + + align:start position:0% +though normally I would definitely call +this King + + align:start position:0% + + + + align:start position:0% + +seven suited I make a pretty big line + + align:start position:0% +seven suited I make a pretty big line + + + align:start position:0% +seven suited I make a pretty big line +for 21 and a half bets from the small + + align:start position:0% +for 21 and a half bets from the small + + + align:start position:0% +for 21 and a half bets from the small +blind and take it down all + + align:start position:0% + + + + align:start position:0% + +right wasn't we'll see if we'll see all + + align:start position:0% +right wasn't we'll see if we'll see all + + + align:start position:0% +right wasn't we'll see if we'll see all +means um so we we full of six three + + align:start position:0% +means um so we we full of six three + + + align:start position:0% +means um so we we full of six three +suited here be my sponsor decided to + + align:start position:0% +suited here be my sponsor decided to + + + align:start position:0% +suited here be my sponsor decided to +raise small which is once again a bit + + align:start position:0% +raise small which is once again a bit + + + align:start position:0% +raise small which is once again a bit +unusual it usually just want to go all + + align:start position:0% +unusual it usually just want to go all + + + align:start position:0% +unusual it usually just want to go all +in a situation where ICM is so relevant + + align:start position:0% +in a situation where ICM is so relevant + + + align:start position:0% +in a situation where ICM is so relevant +and then Nicolas goes on and he folds + + align:start position:0% +and then Nicolas goes on and he folds + + + align:start position:0% +and then Nicolas goes on and he folds +Jack + + align:start position:0% + + + + align:start position:0% + +five offsuit here do we fold so once + + align:start position:0% +five offsuit here do we fold so once + + + align:start position:0% +five offsuit here do we fold so once +again this guy raises small so maybe he + + align:start position:0% +again this guy raises small so maybe he + + + align:start position:0% +again this guy raises small so maybe he +doesn't really want to do this ICM thing + + align:start position:0% +doesn't really want to do this ICM thing + + + align:start position:0% +doesn't really want to do this ICM thing +and just he wants to play box he + + align:start position:0% +and just he wants to play box he + + + align:start position:0% +and just he wants to play box he +takes that one down though Nicholas + + align:start position:0% + + + + align:start position:0% + +Brody so as you can see it's it's a bit + + align:start position:0% +Brody so as you can see it's it's a bit + + + align:start position:0% +Brody so as you can see it's it's a bit +boring there's not too many hands I I + + align:start position:0% +boring there's not too many hands I I + + + align:start position:0% +boring there's not too many hands I I +mean that's sort of what happens when + + align:start position:0% +mean that's sort of what happens when + + + align:start position:0% +mean that's sort of what happens when +there's ICM because you people don't you + + align:start position:0% +there's ICM because you people don't you + + + align:start position:0% +there's ICM because you people don't you +don't really want to splash around you + + align:start position:0% +don't really want to splash around you + + + align:start position:0% +don't really want to splash around you +kind of just want to survive in the + + align:start position:0% +kind of just want to survive in the + + + align:start position:0% +kind of just want to survive in the +tournament by risking all your chips + + align:start position:0% +tournament by risking all your chips + + + align:start position:0% +tournament by risking all your chips +once in a while instead of like slowly + + align:start position:0% +once in a while instead of like slowly + + + align:start position:0% +once in a while instead of like slowly +bleeding your tips in a variety of pots + + align:start position:0% +bleeding your tips in a variety of pots + + + align:start position:0% +bleeding your tips in a variety of pots +so once again we nine suited big all and + + align:start position:0% +so once again we nine suited big all and + + + align:start position:0% +so once again we nine suited big all and +hungie good enough Queen seven suited I + + align:start position:0% +hungie good enough Queen seven suited I + + + align:start position:0% +hungie good enough Queen seven suited I +decided to open it raised it up but + + align:start position:0% +decided to open it raised it up but + + + align:start position:0% +decided to open it raised it up but +unfortunately I guess I mean even if + + align:start position:0% +unfortunately I guess I mean even if + + + align:start position:0% +unfortunately I guess I mean even if +just one guy went on and I'm clearly + + align:start position:0% +just one guy went on and I'm clearly + + + align:start position:0% +just one guy went on and I'm clearly +folding so they both go all-in and Ace + + align:start position:0% +folding so they both go all-in and Ace + + + align:start position:0% +folding so they both go all-in and Ace +King meets Kings which is really bad + + align:start position:0% +King meets Kings which is really bad + + + align:start position:0% +King meets Kings which is really bad +news for everyone essentially because if + + align:start position:0% +news for everyone essentially because if + + + align:start position:0% +news for everyone essentially because if +Kings held then he would have busted but + + align:start position:0% +Kings held then he would have busted but + + + align:start position:0% +Kings held then he would have busted but +unfortunately he doesn't so + + align:start position:0% +unfortunately he doesn't so + + + align:start position:0% +unfortunately he doesn't so +pocket eights I'm racing here this + + align:start position:0% +pocket eights I'm racing here this + + + align:start position:0% +pocket eights I'm racing here this +would have been a gross spot by the way + + align:start position:0% +would have been a gross spot by the way + + + align:start position:0% +would have been a gross spot by the way +I think if + + align:start position:0% +I think if + + + align:start position:0% +I think if +it'd be my song sir went on here I don't + + align:start position:0% +it'd be my song sir went on here I don't + + + align:start position:0% +it'd be my song sir went on here I don't +know what would have that it would it + + align:start position:0% +know what would have that it would it + + + align:start position:0% +know what would have that it would it +would have been very gross because on + + align:start position:0% +would have been very gross because on + + + align:start position:0% +would have been very gross because on +one hand I definitely don't want to be + + align:start position:0% +one hand I definitely don't want to be + + + align:start position:0% +one hand I definitely don't want to be +old folding and hand as good as pocket + + align:start position:0% +old folding and hand as good as pocket + + + align:start position:0% +old folding and hand as good as pocket +eights but on the other hand I see him + + align:start position:0% +eights but on the other hand I see him + + + align:start position:0% +eights but on the other hand I see him +is just so relevant I think I probably + + align:start position:0% +is just so relevant I think I probably + + + align:start position:0% +is just so relevant I think I probably +have to fold so yeah this is a case + + align:start position:0% +have to fold so yeah this is a case + + + align:start position:0% +have to fold so yeah this is a case +where I could have made an extreme like + + align:start position:0% +where I could have made an extreme like + + + align:start position:0% +where I could have made an extreme like +a very a hero fold essentially a fold in + + align:start position:0% +a very a hero fold essentially a fold in + + + align:start position:0% +a very a hero fold essentially a fold in +a very good hand if be my sponsor right + + align:start position:0% +a very good hand if be my sponsor right + + + align:start position:0% +a very good hand if be my sponsor right +all in so + + align:start position:0% + + + + align:start position:0% + +King jack off we get another lock okay + + align:start position:0% + + + + align:start position:0% + +Jack I Jack 10 off um okay this I'll + + align:start position:0% +Jack I Jack 10 off um okay this I'll + + + align:start position:0% +Jack I Jack 10 off um okay this I'll +tell you what happened and then we'll + + align:start position:0% +tell you what happened and then we'll + + + align:start position:0% +tell you what happened and then we'll +take a break and then I'll analyze it + + align:start position:0% +take a break and then I'll analyze it + + + align:start position:0% +take a break and then I'll analyze it +after you listen I want to analyze in a + + align:start position:0% +after you listen I want to analyze in a + + + align:start position:0% +after you listen I want to analyze in a +bit more depth because I was actually + + align:start position:0% +bit more depth because I was actually + + + align:start position:0% +bit more depth because I was actually +surprised going through the replays + + align:start position:0% +surprised going through the replays + + + align:start position:0% +surprised going through the replays +looking at how I played this so LPM + + align:start position:0% +looking at how I played this so LPM + + + align:start position:0% +looking at how I played this so LPM +box makes it 16,000 + + align:start position:0% +box makes it 16,000 + + + align:start position:0% +box makes it 16,000 +and I rearranged to 44 for 44 um + + align:start position:0% +and I rearranged to 44 for 44 um + + + align:start position:0% +and I rearranged to 44 for 44 um +essentially + + align:start position:0% +essentially + + + align:start position:0% +essentially +I think this onion I'm not I don't have + + align:start position:0% +I think this onion I'm not I don't have + + + align:start position:0% +I think this onion I'm not I don't have +a great hand but I think this is one of + + align:start position:0% +a great hand but I think this is one of + + + align:start position:0% +a great hand but I think this is one of +the this hand is too good not to make a + + align:start position:0% +the this hand is too good not to make a + + + align:start position:0% +the this hand is too good not to make a +bluff with so that I do that and then he + + align:start position:0% +bluff with so that I do that and then he + + + align:start position:0% +bluff with so that I do that and then he +goes all-in and then I think this is + + align:start position:0% +goes all-in and then I think this is + + + align:start position:0% +goes all-in and then I think this is +this is a very tough spot because my + + align:start position:0% +this is a very tough spot because my + + + align:start position:0% +this is a very tough spot because my +hand isn't good but when i really is i + + align:start position:0% +hand isn't good but when i really is i + + + align:start position:0% +hand isn't good but when i really is i +definitely had the you know if this guy + + align:start position:0% +definitely had the you know if this guy + + + align:start position:0% +definitely had the you know if this guy +had fewer chips i would have just went + + align:start position:0% +had fewer chips i would have just went + + + align:start position:0% +had fewer chips i would have just went +all-in myself I definitely didn't + + align:start position:0% +all-in myself I definitely didn't + + + align:start position:0% +all-in myself I definitely didn't +rearrange the size thinking I would even + + align:start position:0% +rearrange the size thinking I would even + + + align:start position:0% +rearrange the size thinking I would even +consider folding if he moved on but + + align:start position:0% +consider folding if he moved on but + + + align:start position:0% +consider folding if he moved on but +so yeah the reason I made this size it + + align:start position:0% +so yeah the reason I made this size it + + + align:start position:0% +so yeah the reason I made this size it +so that if this guy went all-in I could + + align:start position:0% +so that if this guy went all-in I could + + + align:start position:0% +so that if this guy went all-in I could +fold but as it turns out heating people + + align:start position:0% +fold but as it turns out heating people + + + align:start position:0% +fold but as it turns out heating people +then he went all-in and then so let's + + align:start position:0% +then he went all-in and then so let's + + + align:start position:0% +then he went all-in and then so let's +analyze this hand after the break we'll + + align:start position:0% +analyze this hand after the break we'll + + + align:start position:0% +analyze this hand after the break we'll +take like a short to three minute break + + align:start position:0% +take like a short to three minute break + + + align:start position:0% +take like a short to three minute break +okay oh yeah I'll get started again so + + align:start position:0% +okay oh yeah I'll get started again so + + + align:start position:0% +okay oh yeah I'll get started again so +get so let's calculate this hand so I + + align:start position:0% +get so let's calculate this hand so I + + + align:start position:0% +get so let's calculate this hand so I +actually decided to go back and + + align:start position:0% +actually decided to go back and + + + align:start position:0% +actually decided to go back and +calculate this hand from an ICM + + align:start position:0% +calculate this hand from an ICM + + + align:start position:0% +calculate this hand from an ICM +perspective because ICM is basically + + align:start position:0% +perspective because ICM is basically + + + align:start position:0% +perspective because ICM is basically +very relevant here okay so let's see + + align:start position:0% +very relevant here okay so let's see + + + align:start position:0% +very relevant here okay so let's see +exactly how to do this in practice okay + + align:start position:0% +exactly how to do this in practice okay + + + align:start position:0% +exactly how to do this in practice okay +so okay + + align:start position:0% +so okay + + + align:start position:0% +so okay +so so okay so let's first see the chip + + align:start position:0% +so so okay so let's first see the chip + + + align:start position:0% +so so okay so let's first see the chip +be be kept the play shape okay let me + + align:start position:0% +be be kept the play shape okay let me + + + align:start position:0% +be be kept the play shape okay let me +pursue that ship TV calculation so I + + align:start position:0% +pursue that ship TV calculation so I + + + align:start position:0% +pursue that ship TV calculation so I +have okay so uh you can trust that I + + align:start position:0% +have okay so uh you can trust that I + + + align:start position:0% +have okay so uh you can trust that I +copied the numbers correctly so it's + + align:start position:0% +copied the numbers correctly so it's + + + align:start position:0% +copied the numbers correctly so it's +actually there's three possibilities + + align:start position:0% +actually there's three possibilities + + + align:start position:0% +actually there's three possibilities +okay there's um if I fold this is the Oh + + align:start position:0% +okay there's um if I fold this is the Oh + + + align:start position:0% +okay there's um if I fold this is the Oh +chips this is the amount of chips I'll + + align:start position:0% +chips this is the amount of chips I'll + + + align:start position:0% +chips this is the amount of chips I'll +have ok so right now I'm only carrying + + align:start position:0% +have ok so right now I'm only carrying + + + align:start position:0% +have ok so right now I'm only carrying +about chips so if I fold this is the + + align:start position:0% +about chips so if I fold this is the + + + align:start position:0% +about chips so if I fold this is the +amount of chips I'll have if I call in + + align:start position:0% +amount of chips I'll have if I call in + + + align:start position:0% +amount of chips I'll have if I call in +wins this is the amount of chips I'll + + align:start position:0% +wins this is the amount of chips I'll + + + align:start position:0% +wins this is the amount of chips I'll +have and if I call and lose this is the + + align:start position:0% +have and if I call and lose this is the + + + align:start position:0% +have and if I call and lose this is the +amount of chips I'll have so we could + + align:start position:0% +amount of chips I'll have so we could + + + align:start position:0% +amount of chips I'll have so we could +basically do a calculation here where I + + align:start position:0% +basically do a calculation here where I + + + align:start position:0% +basically do a calculation here where I +do + + align:start position:0% +do + + + align:start position:0% +do +essentially + + align:start position:0% +essentially + + + align:start position:0% +essentially +it's- so let's say my chances of winning + + align:start position:0% +it's- so let's say my chances of winning + + + align:start position:0% +it's- so let's say my chances of winning +as X so it's x times so + + align:start position:0% +as X so it's x times so + + + align:start position:0% +as X so it's x times so +it's x times how many chips I have if i + + align:start position:0% +it's x times how many chips I have if i + + + align:start position:0% +it's x times how many chips I have if i +if i call them lose which is 107 I'm + + align:start position:0% +if i call them lose which is 107 I'm + + + align:start position:0% +if i call them lose which is 107 I'm +gonna not write the last three zeroes + + align:start position:0% +gonna not write the last three zeroes + + + align:start position:0% +gonna not write the last three zeroes +plus one minus x times 402 + + align:start position:0% +plus one minus x times 402 + + + align:start position:0% +plus one minus x times 402 +sorry + + align:start position:0% +sorry + + + align:start position:0% +sorry +I did this in Reverse ok X is my chances + + align:start position:0% +I did this in Reverse ok X is my chances + + + align:start position:0% +I did this in Reverse ok X is my chances +of losing so again I'm basically + + align:start position:0% +of losing so again I'm basically + + + align:start position:0% +of losing so again I'm basically +comparing this number this is how many + + align:start position:0% +comparing this number this is how many + + + align:start position:0% +comparing this number this is how many +chips I have this by full okay and then + + align:start position:0% +chips I have this by full okay and then + + + align:start position:0% +chips I have this by full okay and then +essentially I'm just solving for x right + + align:start position:0% +essentially I'm just solving for x right + + + align:start position:0% +essentially I'm just solving for x right +so you so the way I do it is I set these + + align:start position:0% +so you so the way I do it is I set these + + + align:start position:0% +so you so the way I do it is I set these +to be equal and then I calculate X and + + align:start position:0% +to be equal and then I calculate X and + + + align:start position:0% +to be equal and then I calculate X and +that's sort of the break-even X which + + align:start position:0% +that's sort of the break-even X which + + + align:start position:0% +that's sort of the break-even X which +tells me what's the minimum equity I + + align:start position:0% +tells me what's the minimum equity I + + + align:start position:0% +tells me what's the minimum equity I +need against his range to call so a so + + align:start position:0% +need against his range to call so a so + + + align:start position:0% +need against his range to call so a so +we can do that so I think it turns out + + align:start position:0% +we can do that so I think it turns out + + + align:start position:0% +we can do that so I think it turns out +to be so this formula is equal to the + + align:start position:0% +to be so this formula is equal to the + + + align:start position:0% +to be so this formula is equal to the +fold - call + + align:start position:0% + + + + align:start position:0% + +/ + + align:start position:0% +/ + + + align:start position:0% +/ +I'm just gonna I did it okay so okay + + align:start position:0% +I'm just gonna I did it okay so okay + + + align:start position:0% +I'm just gonna I did it okay so okay +so I can show these so it's so + + align:start position:0% +so I can show these so it's so + + + align:start position:0% +so I can show these so it's so +essentially it's I had to do one else + + align:start position:0% +essentially it's I had to do one else + + + align:start position:0% +essentially it's I had to do one else +right I to do one odds so it makes sense + + align:start position:0% +right I to do one odds so it makes sense + + + align:start position:0% +right I to do one odds so it makes sense +that I needed a 33% equity you call okay + + align:start position:0% +that I needed a 33% equity you call okay + + + align:start position:0% +that I needed a 33% equity you call okay +so how do we give this side so this is + + align:start position:0% +so how do we give this side so this is + + + align:start position:0% +so how do we give this side so this is +these are essentially the ICM numbers so + + align:start position:0% +these are essentially the ICM numbers so + + + align:start position:0% +these are essentially the ICM numbers so +essentially the way you complete this is + + align:start position:0% +essentially the way you complete this is + + + align:start position:0% +essentially the way you complete this is +you Google ICM + + align:start position:0% +you Google ICM + + + align:start position:0% +you Google ICM +calculator and then you just go to the + + align:start position:0% +calculator and then you just go to the + + + align:start position:0% +calculator and then you just go to the +first one it's usually quite easy to + + align:start position:0% +first one it's usually quite easy to + + + align:start position:0% +first one it's usually quite easy to +find okay so it's a bit tricky because + + align:start position:0% +find okay so it's a bit tricky because + + + align:start position:0% +find okay so it's a bit tricky because +you have to put in the exact payouts so + + align:start position:0% +you have to put in the exact payouts so + + + align:start position:0% +you have to put in the exact payouts so +I think at the time they were like + + align:start position:0% +I think at the time they were like + + + align:start position:0% +I think at the time they were like +eighteen point five this this is all as + + align:start position:0% +eighteen point five this this is all as + + + align:start position:0% +eighteen point five this this is all as +a percentage of the total pot so I + + align:start position:0% +a percentage of the total pot so I + + + align:start position:0% +a percentage of the total pot so I +forget exactly the numbers but it was + + align:start position:0% +forget exactly the numbers but it was + + + align:start position:0% +forget exactly the numbers but it was +something like this okay and then you + + align:start position:0% +something like this okay and then you + + + align:start position:0% +something like this okay and then you +type in the force you type in the stack + + align:start position:0% +type in the force you type in the stack + + + align:start position:0% +type in the force you type in the stack +sizes so it takes a bit of time and you + + align:start position:0% +sizes so it takes a bit of time and you + + + align:start position:0% +sizes so it takes a bit of time and you +know even if you're fast at this if you + + align:start position:0% +know even if you're fast at this if you + + + align:start position:0% +know even if you're fast at this if you +conserve your entire time bank from the + + align:start position:0% +conserve your entire time bank from the + + + align:start position:0% +conserve your entire time bank from the +whole tournament for this one population + + align:start position:0% +whole tournament for this one population + + + align:start position:0% +whole tournament for this one population +you probably have enough time to do it + + align:start position:0% +you probably have enough time to do it + + + align:start position:0% +you probably have enough time to do it +because you're gonna have like you'll + + align:start position:0% +because you're gonna have like you'll + + + align:start position:0% +because you're gonna have like you'll +probably have like two or three minutes + + align:start position:0% +probably have like two or three minutes + + + align:start position:0% +probably have like two or three minutes +of time back saved up so you can you + + align:start position:0% +of time back saved up so you can you + + + align:start position:0% +of time back saved up so you can you +probably can do it you have to + + align:start position:0% +probably can do it you have to + + + align:start position:0% +probably can do it you have to +essentially right so there's three + + align:start position:0% +essentially right so there's three + + + align:start position:0% +essentially right so there's three +possibilities I have to calculate if I + + align:start position:0% +possibilities I have to calculate if I + + + align:start position:0% +possibilities I have to calculate if I +fold not only how many chips I have but + + align:start position:0% +fold not only how many chips I have but + + + align:start position:0% +fold not only how many chips I have but +how many chips everyone else has and + + align:start position:0% +how many chips everyone else has and + + + align:start position:0% +how many chips everyone else has and +then I take them in and then I think + + align:start position:0% +then I take them in and then I think + + + align:start position:0% +then I take them in and then I think +that's actually calculate the value of + + align:start position:0% +that's actually calculate the value of + + + align:start position:0% +that's actually calculate the value of +my stack in terms of as a fraction of + + align:start position:0% +my stack in terms of as a fraction of + + + align:start position:0% +my stack in terms of as a fraction of +the total money in a pot and then + + align:start position:0% +the total money in a pot and then + + + align:start position:0% +the total money in a pot and then +similarly I do it for the other two + + align:start position:0% +similarly I do it for the other two + + + align:start position:0% +similarly I do it for the other two +cases and then I calculate the ICM + + align:start position:0% +cases and then I calculate the ICM + + + align:start position:0% +cases and then I calculate the ICM +numbers and roughly speaking this is my + + align:start position:0% +numbers and roughly speaking this is my + + + align:start position:0% +numbers and roughly speaking this is my +from + + align:start position:0% +from + + + align:start position:0% +from +these are all this is all normalized but + + align:start position:0% +these are all this is all normalized but + + + align:start position:0% +these are all this is all normalized but +these are rough this is roughly midol or + + align:start position:0% +these are rough this is roughly midol or + + + align:start position:0% +these are rough this is roughly midol or +EB in each of these three scenarios and + + align:start position:0% +EB in each of these three scenarios and + + + align:start position:0% +EB in each of these three scenarios and +if I do the same if I do the same + + align:start position:0% +if I do the same if I do the same + + + align:start position:0% +if I do the same if I do the same +calculation I'll find that I actually + + align:start position:0% +calculation I'll find that I actually + + + align:start position:0% +calculation I'll find that I actually +39.6 + + align:start position:0% +39.6 + + + align:start position:0% +39.6 +equity okay so so far does the + + align:start position:0% +equity okay so so far does the + + + align:start position:0% +equity okay so so far does the +calculation make sense to everyone I + + align:start position:0% +calculation make sense to everyone I + + + align:start position:0% +calculation make sense to everyone I +didn't do all the steps in practice but + + align:start position:0% +didn't do all the steps in practice but + + + align:start position:0% +didn't do all the steps in practice but +I explain how to do all the steps so + + align:start position:0% +I explain how to do all the steps so + + + align:start position:0% +I explain how to do all the steps so +this yeah if you're fast it takes it + + align:start position:0% +this yeah if you're fast it takes it + + + align:start position:0% +this yeah if you're fast it takes it +still takes like a minute a minute and a + + align:start position:0% +still takes like a minute a minute and a + + + align:start position:0% +still takes like a minute a minute and a +half but the last part is now we have to + + align:start position:0% +half but the last part is now we have to + + + align:start position:0% +half but the last part is now we have to +open poker state now we have to take + + align:start position:0% +open poker state now we have to take + + + align:start position:0% +open poker state now we have to take +them to Jack ten off C and then we have + + align:start position:0% +them to Jack ten off C and then we have + + + align:start position:0% +them to Jack ten off C and then we have +to put him on the range so so okay let's + + align:start position:0% +to put him on the range so so okay let's + + + align:start position:0% +to put him on the range so so okay let's +just put him on a Sookie I suspect that + + align:start position:0% +just put him on a Sookie I suspect that + + + align:start position:0% +just put him on a Sookie I suspect that +I'm probably gonna have to fold because + + align:start position:0% +I'm probably gonna have to fold because + + + align:start position:0% +I'm probably gonna have to fold because +39.6% is quite a lot so I'm gonna put + + align:start position:0% +39.6% is quite a lot so I'm gonna put + + + align:start position:0% +39.6% is quite a lot so I'm gonna put +him on the loosest I'm gonna put him on + + align:start position:0% +him on the loosest I'm gonna put him on + + + align:start position:0% +him on the loosest I'm gonna put him on +the loosest range and see if I have + + align:start position:0% +the loosest range and see if I have + + + align:start position:0% +the loosest range and see if I have +thirty nine point six so + + align:start position:0% +thirty nine point six so + + + align:start position:0% +thirty nine point six so +let's say he's pretty loose so he's + + align:start position:0% +let's say he's pretty loose so he's + + + align:start position:0% +let's say he's pretty loose so he's +going to gamble with let's say pocket + + align:start position:0% +going to gamble with let's say pocket + + + align:start position:0% +going to gamble with let's say pocket +fours plus I mean this another thing to + + align:start position:0% +fours plus I mean this another thing to + + + align:start position:0% +fours plus I mean this another thing to +be that's relevant here is I think it + + align:start position:0% +be that's relevant here is I think it + + + align:start position:0% +be that's relevant here is I think it +looks like he doesn't have full equity + + align:start position:0% +looks like he doesn't have full equity + + + align:start position:0% +looks like he doesn't have full equity +like I don't think Wendy's going on here + + align:start position:0% +like I don't think Wendy's going on here + + + align:start position:0% +like I don't think Wendy's going on here +he suspects that I'm ever folding or at + + align:start position:0% +he suspects that I'm ever folding or at + + + align:start position:0% +he suspects that I'm ever folding or at +least he probably thinks I'm calling him + + align:start position:0% +least he probably thinks I'm calling him + + + align:start position:0% +least he probably thinks I'm calling him +the overwhelming majority of the time so + + align:start position:0% +the overwhelming majority of the time so + + + align:start position:0% +the overwhelming majority of the time so +I think he's really gonna turn up a + + align:start position:0% +I think he's really gonna turn up a + + + align:start position:0% +I think he's really gonna turn up a +stone bluff like eight seven suited + + align:start position:0% +stone bluff like eight seven suited + + + align:start position:0% +stone bluff like eight seven suited +because of this so I would I would I + + align:start position:0% +because of this so I would I would I + + + align:start position:0% +because of this so I would I would I +would be very surprised if he ever had + + align:start position:0% +would be very surprised if he ever had + + + align:start position:0% +would be very surprised if he ever had +eight seven suited unless he would + + align:start position:0% +eight seven suited unless he would + + + align:start position:0% +eight seven suited unless he would +somehow unless he read into this and + + align:start position:0% +somehow unless he read into this and + + + align:start position:0% +somehow unless he read into this and +realized that I could actually fold some + + align:start position:0% +realized that I could actually fold some + + + align:start position:0% +realized that I could actually fold some +hands here which maybe he did I do you + + align:start position:0% +hands here which maybe he did I do you + + + align:start position:0% +hands here which maybe he did I do you +shouldn't give them enough credit so um + + align:start position:0% +shouldn't give them enough credit so um + + + align:start position:0% +shouldn't give them enough credit so um +okay let just do something somewhat + + align:start position:0% +okay let just do something somewhat + + + align:start position:0% +okay let just do something somewhat +quick let's say he called the he gets it + + align:start position:0% +quick let's say he called the he gets it + + + align:start position:0% +quick let's say he called the he gets it +in with he stayed off suit a spy suited + + align:start position:0% +in with he stayed off suit a spy suited + + + align:start position:0% +in with he stayed off suit a spy suited +plus King Jack suited King Queen off and + + align:start position:0% +plus King Jack suited King Queen off and + + + align:start position:0% +plus King Jack suited King Queen off and +pocket fours plus so that's like 14.6% + + align:start position:0% +pocket fours plus so that's like 14.6% + + + align:start position:0% +pocket fours plus so that's like 14.6% +of hands so let's do this so against + + align:start position:0% +of hands so let's do this so against + + + align:start position:0% +of hands so let's do this so against +this we have we have thirty six percent + + align:start position:0% +this we have we have thirty six percent + + + align:start position:0% +this we have we have thirty six percent +equity so that's not enough we need + + align:start position:0% +equity so that's not enough we need + + + align:start position:0% +equity so that's not enough we need +thirty nine let's see how wide this + + align:start position:0% +thirty nine let's see how wide this + + + align:start position:0% +thirty nine let's see how wide this +range has to be for us we have 39 all + + align:start position:0% +range has to be for us we have 39 all + + + align:start position:0% +range has to be for us we have 39 all +right let's say he gets in um there's + + align:start position:0% +right let's say he gets in um there's + + + align:start position:0% +right let's say he gets in um there's +20% of hands which is quite a lot which + + align:start position:0% +20% of hands which is quite a lot which + + + align:start position:0% +20% of hands which is quite a lot which +is I think way too much 18.6% + + align:start position:0% +is I think way too much 18.6% + + + align:start position:0% +is I think way too much 18.6% +of hands oh we + + align:start position:0% +of hands oh we + + + align:start position:0% +of hands oh we +actually haven't worse against this + + align:start position:0% +actually haven't worse against this + + + align:start position:0% +actually haven't worse against this +range because her suppose these it has + + align:start position:0% +range because her suppose these it has + + + align:start position:0% +range because her suppose these it has +more hands than dominate us because I + + align:start position:0% +more hands than dominate us because I + + + align:start position:0% +more hands than dominate us because I +put in a lot of hands like King 10 and + + align:start position:0% +put in a lot of hands like King 10 and + + + align:start position:0% +put in a lot of hands like King 10 and +removed a lot of the hands like a sports + + align:start position:0% +removed a lot of the hands like a sports + + + align:start position:0% +removed a lot of the hands like a sports +so basically + + align:start position:0% +so basically + + + align:start position:0% +so basically +okay you could play with it however you + + align:start position:0% +okay you could play with it however you + + + align:start position:0% +okay you could play with it however you +want but I think it's hard to play with + + align:start position:0% +want but I think it's hard to play with + + + align:start position:0% +want but I think it's hard to play with +it in the way to give yourself 39 + + align:start position:0% +it in the way to give yourself 39 + + + align:start position:0% +it in the way to give yourself 39 +percent equity yeah see we're very + + align:start position:0% +percent equity yeah see we're very + + + align:start position:0% +percent equity yeah see we're very +optimistic about how wide his range was + + align:start position:0% +optimistic about how wide his range was + + + align:start position:0% +optimistic about how wide his range was +so any other case so so at the time I + + align:start position:0% +so any other case so so at the time I + + + align:start position:0% +so any other case so so at the time I +did fold and it looked weird to me at + + align:start position:0% +did fold and it looked weird to me at + + + align:start position:0% +did fold and it looked weird to me at +first but after analyzing it I think + + align:start position:0% +first but after analyzing it I think + + + align:start position:0% +first but after analyzing it I think +this is kept playing the right play if + + align:start position:0% +this is kept playing the right play if + + + align:start position:0% +this is kept playing the right play if +you take into account ICM so I think + + align:start position:0% +you take into account ICM so I think + + + align:start position:0% +you take into account ICM so I think +it's a good example of ICM because if + + align:start position:0% +it's a good example of ICM because if + + + align:start position:0% +it's a good example of ICM because if +you remember like the one we were + + align:start position:0% +you remember like the one we were + + + align:start position:0% +you remember like the one we were +playing with it our equity was always + + align:start position:0% +playing with it our equity was always + + + align:start position:0% +playing with it our equity was always +essentially between 33 and 39 like if we + + align:start position:0% +essentially between 33 and 39 like if we + + + align:start position:0% +essentially between 33 and 39 like if we +put them on a looser range our equity + + align:start position:0% +put them on a looser range our equity + + + align:start position:0% +put them on a looser range our equity +would be like 37 and if we put them on a + + align:start position:0% +would be like 37 and if we put them on a + + + align:start position:0% +would be like 37 and if we put them on a +tighter range our equity would be like + + align:start position:0% +tighter range our equity would be like + + + align:start position:0% +tighter range our equity would be like +34 but basically it's all it's a + + align:start position:0% +34 but basically it's all it's a + + + align:start position:0% +34 but basically it's all it's a +situation where I would always call if I + + align:start position:0% +situation where I would always call if I + + + align:start position:0% +situation where I would always call if I +see him was not relevant and always fold + + align:start position:0% +see him was not relevant and always fold + + + align:start position:0% +see him was not relevant and always fold +if I see him was relevant and and + + align:start position:0% +if I see him was relevant and and + + + align:start position:0% +if I see him was relevant and and +this isn't even the case where it looks + + align:start position:0% +this isn't even the case where it looks + + + align:start position:0% +this isn't even the case where it looks +like I see em should be that relevant + + align:start position:0% +like I see em should be that relevant + + + align:start position:0% +like I see em should be that relevant +but I guess yeah so we do fold so so you + + align:start position:0% +but I guess yeah so we do fold so so you + + + align:start position:0% +but I guess yeah so we do fold so so you +know with hindsight maybe my initial + + align:start position:0% +know with hindsight maybe my initial + + + align:start position:0% +know with hindsight maybe my initial +strategy was wrongly maybe I should have + + align:start position:0% +strategy was wrongly maybe I should have + + + align:start position:0% +strategy was wrongly maybe I should have +should not have even plus two maybe I + + align:start position:0% +should not have even plus two maybe I + + + align:start position:0% +should not have even plus two maybe I +should have just fold it in the first + + align:start position:0% +should have just fold it in the first + + + align:start position:0% +should have just fold it in the first +place that's that's a different story + + align:start position:0% +place that's that's a different story + + + align:start position:0% +place that's that's a different story +but given that I did Bluff I think the + + align:start position:0% +but given that I did Bluff I think the + + + align:start position:0% +but given that I did Bluff I think the +best thing I can do your response okay + + align:start position:0% +best thing I can do your response okay + + + align:start position:0% +best thing I can do your response okay +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +let me just jump jump back to the + + align:start position:0% +let me just jump jump back to the + + + align:start position:0% +let me just jump jump back to the +PowerPoint for so I just want to talk + + align:start position:0% +PowerPoint for so I just want to talk + + + align:start position:0% +PowerPoint for so I just want to talk +about a bit more about this theory of + + align:start position:0% +about a bit more about this theory of + + + align:start position:0% +about a bit more about this theory of +sort of satellites and going all in the + + align:start position:0% +sort of satellites and going all in the + + + align:start position:0% +sort of satellites and going all in the +first so if in game theory this is sort + + align:start position:0% +first so if in game theory this is sort + + + align:start position:0% +first so if in game theory this is sort +of called the traffic intersection game + + align:start position:0% +of called the traffic intersection game + + + align:start position:0% +of called the traffic intersection game +so ICM does not say play tighter it + + align:start position:0% +so ICM does not say play tighter it + + + align:start position:0% +so ICM does not say play tighter it +allows you to play looser if you can go + + align:start position:0% +allows you to play looser if you can go + + + align:start position:0% +allows you to play looser if you can go +all in first so this is where it's I + + align:start position:0% +all in first so this is where it's I + + + align:start position:0% +all in first so this is where it's I +actually think it's very interesting + + align:start position:0% +actually think it's very interesting + + + align:start position:0% +actually think it's very interesting +because in satellites you want to be + + align:start position:0% +because in satellites you want to be + + + align:start position:0% +because in satellites you want to be +under the gun right so normally in poker + + align:start position:0% +under the gun right so normally in poker + + + align:start position:0% +under the gun right so normally in poker +that's sort of the worst position + + align:start position:0% +that's sort of the worst position + + + align:start position:0% +that's sort of the worst position +because you gotta act first everyone + + align:start position:0% +because you gotta act first everyone + + + align:start position:0% +because you gotta act first everyone +else gets to act act after you but in + + align:start position:0% +else gets to act act after you but in + + + align:start position:0% +else gets to act act after you but in +satellites basically you just want to be + + align:start position:0% +satellites basically you just want to be + + + align:start position:0% +satellites basically you just want to be +the first person to be able to threat + + align:start position:0% +the first person to be able to threat + + + align:start position:0% +the first person to be able to threat +and say look I'm putting all my chips in + + align:start position:0% +and say look I'm putting all my chips in + + + align:start position:0% +and say look I'm putting all my chips in +you pretty much have to fold and that's + + align:start position:0% +you pretty much have to fold and that's + + + align:start position:0% +you pretty much have to fold and that's +so and satellites let's say there's 11 + + align:start position:0% +so and satellites let's say there's 11 + + + align:start position:0% +so and satellites let's say there's 11 +people left and 10 people get a seat if + + align:start position:0% +people left and 10 people get a seat if + + + align:start position:0% +people left and 10 people get a seat if +you go on no one can call you even if + + align:start position:0% +you go on no one can call you even if + + + align:start position:0% +you go on no one can call you even if +they have aces because if you because + + align:start position:0% +they have aces because if you because + + + align:start position:0% +they have aces because if you because +you call you they essentially need to be + + align:start position:0% +you call you they essentially need to be + + + align:start position:0% +you call you they essentially need to be +more than 10 11 sure that they're gonna + + align:start position:0% +more than 10 11 sure that they're gonna + + + align:start position:0% +more than 10 11 sure that they're gonna +win the hand and even if they have + + align:start position:0% +win the hand and even if they have + + + align:start position:0% +win the hand and even if they have +populations they're not going to be 10 + + align:start position:0% +populations they're not going to be 10 + + + align:start position:0% +populations they're not going to be 10 +11 sir that they they're gonna win the + + align:start position:0% +11 sir that they they're gonna win the + + + align:start position:0% +11 sir that they they're gonna win the +hand so basically + + align:start position:0% +hand so basically + + + align:start position:0% +hand so basically +going Owens first is very very good it's + + align:start position:0% +going Owens first is very very good it's + + + align:start position:0% +going Owens first is very very good it's +essentially like it so it's called the + + align:start position:0% +essentially like it so it's called the + + + align:start position:0% +essentially like it so it's called the +traffic intersection game because you + + align:start position:0% +traffic intersection game because you + + + align:start position:0% +traffic intersection game because you +can imagine the situation where there's + + align:start position:0% +can imagine the situation where there's + + + align:start position:0% +can imagine the situation where there's +like two cards trying to pass each other + + align:start position:0% +like two cards trying to pass each other + + + align:start position:0% +like two cards trying to pass each other +at an intersection and you sort of want + + align:start position:0% +at an intersection and you sort of want + + + align:start position:0% +at an intersection and you sort of want +to save time you pass get there first + + align:start position:0% +to save time you pass get there first + + + align:start position:0% +to save time you pass get there first +but you're worried that the other guy + + align:start position:0% +but you're worried that the other guy + + + align:start position:0% +but you're worried that the other guy +might crash right you don't yet both + + align:start position:0% +might crash right you don't yet both + + + align:start position:0% +might crash right you don't yet both +players really want to avoid an accident + + align:start position:0% +players really want to avoid an accident + + + align:start position:0% +players really want to avoid an accident +but both those players really want to be + + align:start position:0% +but both those players really want to be + + + align:start position:0% +but both those players really want to be +the guy to get through first well if you + + align:start position:0% +the guy to get through first well if you + + + align:start position:0% +the guy to get through first well if you +can act first and if you just tell the + + align:start position:0% +can act first and if you just tell the + + + align:start position:0% +can act first and if you just tell the +guy look I'm like closing my eyes and + + align:start position:0% +guy look I'm like closing my eyes and + + + align:start position:0% +guy look I'm like closing my eyes and +tie up my hands I cannot stop my car + + align:start position:0% +tie up my hands I cannot stop my car + + + align:start position:0% +tie up my hands I cannot stop my car +okay I'm just gonna go through the + + align:start position:0% +okay I'm just gonna go through the + + + align:start position:0% +okay I'm just gonna go through the +intersection no matter what right if + + align:start position:0% +intersection no matter what right if + + + align:start position:0% +intersection no matter what right if +you're the first person to be able to do + + align:start position:0% +you're the first person to be able to do + + + align:start position:0% +you're the first person to be able to do +this then the other guy he's like okay I + + align:start position:0% +this then the other guy he's like okay I + + + align:start position:0% +this then the other guy he's like okay I +guess I got to stop my car now I'm glad + + align:start position:0% +guess I got to stop my car now I'm glad + + + align:start position:0% +guess I got to stop my car now I'm glad +you go first all right that's + + align:start position:0% +you go first all right that's + + + align:start position:0% +you go first all right that's +essentially what it's like if you're the + + align:start position:0% +essentially what it's like if you're the + + + align:start position:0% +essentially what it's like if you're the +first person to go all-in and you + + align:start position:0% +first person to go all-in and you + + + align:start position:0% +first person to go all-in and you +already said look I'm all-in and there's + + align:start position:0% +already said look I'm all-in and there's + + + align:start position:0% +already said look I'm all-in and there's +nothing I can do to take my chips back + + align:start position:0% +nothing I can do to take my chips back + + + align:start position:0% +nothing I can do to take my chips back +then the other guys like all right I + + align:start position:0% +then the other guys like all right I + + + align:start position:0% +then the other guys like all right I +guess I'll fold and you can win the + + align:start position:0% +guess I'll fold and you can win the + + + align:start position:0% +guess I'll fold and you can win the +blinds so it's sort of how it works I + + align:start position:0% +blinds so it's sort of how it works I + + + align:start position:0% +blinds so it's sort of how it works I +mean of course some opponents are not + + align:start position:0% +mean of course some opponents are not + + + align:start position:0% +mean of course some opponents are not +rational right if you do this enough + + align:start position:0% +rational right if you do this enough + + + align:start position:0% +rational right if you do this enough +times he might fly okay screw this I'm + + align:start position:0% +times he might fly okay screw this I'm + + + align:start position:0% +times he might fly okay screw this I'm +just gonna kill this guy right so it's a + + align:start position:0% +just gonna kill this guy right so it's a + + + align:start position:0% +just gonna kill this guy right so it's a +bit weird and you know in practice this + + align:start position:0% +bit weird and you know in practice this + + + align:start position:0% +bit weird and you know in practice this +happens a lot too I definitely had very + + align:start position:0% +happens a lot too I definitely had very + + + align:start position:0% +happens a lot too I definitely had very +bad situations where you know I'm going + + align:start position:0% +bad situations where you know I'm going + + + align:start position:0% +bad situations where you know I'm going +on with any two cards and I know this is + + align:start position:0% +on with any two cards and I know this is + + + align:start position:0% +on with any two cards and I know this is +a game theoretically optimal strategy + + align:start position:0% +a game theoretically optimal strategy + + + align:start position:0% +a game theoretically optimal strategy +but my opponent is fed up and then he + + align:start position:0% +but my opponent is fed up and then he + + + align:start position:0% +but my opponent is fed up and then he +calls me with like ace Jack or something + + align:start position:0% +calls me with like ace Jack or something + + + align:start position:0% +calls me with like ace Jack or something +and then I have like Jack to off Susan + + align:start position:0% +and then I have like Jack to off Susan + + + align:start position:0% +and then I have like Jack to off Susan +he looks like a genius and he beats me + + align:start position:0% +he looks like a genius and he beats me + + + align:start position:0% +he looks like a genius and he beats me +when his plays just like terrible + + align:start position:0% +when his plays just like terrible + + + align:start position:0% +when his plays just like terrible +basically oh yeah right + + align:start position:0% + + + + align:start position:0% + +so the snack size doesn't matter yet so + + align:start position:0% +so the snack size doesn't matter yet so + + + align:start position:0% +so the snack size doesn't matter yet so +I'm assuming if everyone had the same + + align:start position:0% +I'm assuming if everyone had the same + + + align:start position:0% +I'm assuming if everyone had the same +snack size in that extreme example where + + align:start position:0% +snack size in that extreme example where + + + align:start position:0% +snack size in that extreme example where +I said other people should fold aces I'm + + align:start position:0% +I said other people should fold aces I'm + + + align:start position:0% +I said other people should fold aces I'm +assuming everyone has the same success I + + align:start position:0% +assuming everyone has the same success I + + + align:start position:0% +assuming everyone has the same success I +guess where's the balance between + + align:start position:0% +guess where's the balance between + + + align:start position:0% +guess where's the balance between +knocking + + align:start position:0% +knocking + + + align:start position:0% +knocking +you out versus the chip stack I like the + + align:start position:0% +you out versus the chip stack I like the + + + align:start position:0% +you out versus the chip stack I like the +chips differential right right exactly + + align:start position:0% +chips differential right right exactly + + + align:start position:0% +chips differential right right exactly +so so the reason in that case where it's + + align:start position:0% +so so the reason in that case where it's + + + align:start position:0% +so so the reason in that case where it's +correctable aces is because like let's + + align:start position:0% +correctable aces is because like let's + + + align:start position:0% +correctable aces is because like let's +say they call and knock me out it + + align:start position:0% +say they call and knock me out it + + + align:start position:0% +say they call and knock me out it +doesn't help them that much because + + align:start position:0% +doesn't help them that much because + + + align:start position:0% +doesn't help them that much because +first place in a satellite does not get + + align:start position:0% +first place in a satellite does not get + + + align:start position:0% +first place in a satellite does not get +paid anymore than intense plus but in + + align:start position:0% +paid anymore than intense plus but in + + + align:start position:0% +paid anymore than intense plus but in +real tournaments you'd basically never + + align:start position:0% +real tournaments you'd basically never + + + align:start position:0% +real tournaments you'd basically never +hold aces because even if you're risking + + align:start position:0% +hold aces because even if you're risking + + + align:start position:0% +hold aces because even if you're risking +losing all your money just first place + + align:start position:0% +losing all your money just first place + + + align:start position:0% +losing all your money just first place +will be higher than second place buy it + + align:start position:0% +will be higher than second place buy it + + + align:start position:0% +will be higher than second place buy it +up and winning with those aces will + + align:start position:0% +up and winning with those aces will + + + align:start position:0% +up and winning with those aces will +increases your chances of coming first + + align:start position:0% +increases your chances of coming first + + + align:start position:0% +increases your chances of coming first +by so much that you should just gamble + + align:start position:0% +by so much that you should just gamble + + + align:start position:0% +by so much that you should just gamble +anyway but so this is only in semblance + + align:start position:0% +anyway but so this is only in semblance + + + align:start position:0% +anyway but so this is only in semblance +yeah please don't hold aces in like a + + align:start position:0% +yeah please don't hold aces in like a + + + align:start position:0% +yeah please don't hold aces in like a +normal person + + align:start position:0% +normal person + + + align:start position:0% +normal person +yeah if your shorts back in a sack viola + + align:start position:0% +yeah if your shorts back in a sack viola + + + align:start position:0% +yeah if your shorts back in a sack viola +wanna show two steps and this is going + + align:start position:0% +wanna show two steps and this is going + + + align:start position:0% +wanna show two steps and this is going +all-in still makes sense because people + + align:start position:0% +all-in still makes sense because people + + + align:start position:0% +all-in still makes sense because people +can call you without risking a + + align:start position:0% +can call you without risking a + + + align:start position:0% +can call you without risking a +tournament right exactly so in that case + + align:start position:0% +tournament right exactly so in that case + + + align:start position:0% +tournament right exactly so in that case +you actually need a goodie and you go + + align:start position:0% +you actually need a goodie and you go + + + align:start position:0% +you actually need a goodie and you go +online like you actually need to have + + align:start position:0% +online like you actually need to have + + + align:start position:0% +online like you actually need to have +positive chip EP as well to go on yeah + + align:start position:0% +positive chip EP as well to go on yeah + + + align:start position:0% +positive chip EP as well to go on yeah +so that's why when I see em is relevant + + align:start position:0% +so that's why when I see em is relevant + + + align:start position:0% +so that's why when I see em is relevant +the small stack swing and the big story + + align:start position:0% +the small stack swing and the big story + + + align:start position:0% +the small stack swing and the big story +the small stacks lose and the big stack + + align:start position:0% +the small stacks lose and the big stack + + + align:start position:0% +the small stacks lose and the big stack +swing because the big stacks have more + + align:start position:0% +swing because the big stacks have more + + + align:start position:0% +swing because the big stacks have more +license to bully the small sacks around + + align:start position:0% +license to bully the small sacks around + + + align:start position:0% +license to bully the small sacks around +where is the sauce tax can't ya because + + align:start position:0% +where is the sauce tax can't ya because + + + align:start position:0% +where is the sauce tax can't ya because +the big stacks and call them more often + + align:start position:0% +the big stacks and call them more often + + + align:start position:0% +the big stacks and call them more often +and and also does it matter if other + + align:start position:0% +and and also does it matter if other + + + align:start position:0% +and and also does it matter if other +people have like raised behind you it + + align:start position:0% +people have like raised behind you it + + + align:start position:0% +people have like raised behind you it +doesn't just matter who goes all in + + align:start position:0% +doesn't just matter who goes all in + + + align:start position:0% +doesn't just matter who goes all in +first so + + align:start position:0% +first so + + + align:start position:0% +first so +if someone's already raised then it's + + align:start position:0% +if someone's already raised then it's + + + align:start position:0% +if someone's already raised then it's +like more likely you going all-in like + + align:start position:0% +like more likely you going all-in like + + + align:start position:0% +like more likely you going all-in like +it's more likely they're already + + align:start position:0% +it's more likely they're already + + + align:start position:0% +it's more likely they're already +committed so that if you go on they + + align:start position:0% +committed so that if you go on they + + + align:start position:0% +committed so that if you go on they +won't fold so so that is relevant yeah + + align:start position:0% +won't fold so so that is relevant yeah + + + align:start position:0% +won't fold so so that is relevant yeah +okay + + align:start position:0% +okay + + + align:start position:0% +okay +right so + + align:start position:0% +right so + + + align:start position:0% +right so +so so exactly so like in practice it's + + align:start position:0% +so so exactly so like in practice it's + + + align:start position:0% +so so exactly so like in practice it's +very tricky and in fact it can be + + align:start position:0% +very tricky and in fact it can be + + + align:start position:0% +very tricky and in fact it can be +beneficial if you can somehow convince + + align:start position:0% +beneficial if you can somehow convince + + + align:start position:0% +beneficial if you can somehow convince +your opponents that you're not rational + + align:start position:0% +your opponents that you're not rational + + + align:start position:0% +your opponents that you're not rational +I've never personally done this but I've + + align:start position:0% +I've never personally done this but I've + + + align:start position:0% +I've never personally done this but I've +heard of people like making a bad call + + align:start position:0% +heard of people like making a bad call + + + align:start position:0% +heard of people like making a bad call +sometimes in assembly just so people + + align:start position:0% +sometimes in assembly just so people + + + align:start position:0% +sometimes in assembly just so people +know inoculate mess of them essentially + + align:start position:0% +know inoculate mess of them essentially + + + align:start position:0% +know inoculate mess of them essentially +good I mean it's it's a bit weird so it + + align:start position:0% +good I mean it's it's a bit weird so it + + + align:start position:0% +good I mean it's it's a bit weird so it +is there's this weird meta game with + + align:start position:0% +is there's this weird meta game with + + + align:start position:0% +is there's this weird meta game with +this traffic intersection type game + + align:start position:0% +this traffic intersection type game + + + align:start position:0% +this traffic intersection type game +although this is only relevant in like + + align:start position:0% +although this is only relevant in like + + + align:start position:0% +although this is only relevant in like +the most extreme ICL situations which + + align:start position:0% +the most extreme ICL situations which + + + align:start position:0% +the most extreme ICL situations which +are like satellites um so + + align:start position:0% +are like satellites um so + + + align:start position:0% +are like satellites um so +I mean I should say one scenario where I + + align:start position:0% +I mean I should say one scenario where I + + + align:start position:0% +I mean I should say one scenario where I +think you could consider folding aces + + align:start position:0% +think you could consider folding aces + + + align:start position:0% +think you could consider folding aces +preflop in a normal tournament is + + align:start position:0% +preflop in a normal tournament is + + + align:start position:0% +preflop in a normal tournament is +actually this so let's say let's say + + align:start position:0% +actually this so let's say let's say + + + align:start position:0% +actually this so let's say let's say +there's 55 and Tilden let's say 54 get + + align:start position:0% +there's 55 and Tilden let's say 54 get + + + align:start position:0% +there's 55 and Tilden let's say 54 get +paid and there's 55 left and you got one + + align:start position:0% +paid and there's 55 left and you got one + + + align:start position:0% +paid and there's 55 left and you got one +chip and everyone else as thousands of + + align:start position:0% +chip and everyone else as thousands of + + + align:start position:0% +chip and everyone else as thousands of +chips and you know that like someone + + align:start position:0% +chips and you know that like someone + + + align:start position:0% +chips and you know that like someone +else has already gotten eliminated that + + align:start position:0% +else has already gotten eliminated that + + + align:start position:0% +else has already gotten eliminated that +hand so like if you fold it guarantee to + + align:start position:0% +hand so like if you fold it guarantee to + + + align:start position:0% +hand so like if you fold it guarantee to +get in the money then I would definitely + + align:start position:0% +get in the money then I would definitely + + + align:start position:0% +get in the money then I would definitely +fold aces because even if you win and + + align:start position:0% +fold aces because even if you win and + + + align:start position:0% +fold aces because even if you win and +double up congratulations you don't have + + align:start position:0% +double up congratulations you don't have + + + align:start position:0% +double up congratulations you don't have +ten chips instead of one chip you + + align:start position:0% +ten chips instead of one chip you + + + align:start position:0% +ten chips instead of one chip you +everyone still has thousands of chips so + + align:start position:0% +everyone still has thousands of chips so + + + align:start position:0% +everyone still has thousands of chips so +and so there are cases where you could + + align:start position:0% +and so there are cases where you could + + + align:start position:0% +and so there are cases where you could +construct an extreme case where you + + align:start position:0% +construct an extreme case where you + + + align:start position:0% +construct an extreme case where you +should fold aces preflop in a tournament + + align:start position:0% +should fold aces preflop in a tournament + + + align:start position:0% +should fold aces preflop in a tournament +in a normal tournament as well okay + + align:start position:0% +in a normal tournament as well okay + + + align:start position:0% +in a normal tournament as well okay +so let's get back to the tournament now + + align:start position:0% +so let's get back to the tournament now + + + align:start position:0% +so let's get back to the tournament now +okay + + align:start position:0% +okay + + + align:start position:0% +okay +where were we so okay so yeah so we lost + + align:start position:0% +where were we so okay so yeah so we lost + + + align:start position:0% +where were we so okay so yeah so we lost +a bunch of chips here but so the next + + align:start position:0% +a bunch of chips here but so the next + + + align:start position:0% +a bunch of chips here but so the next +hand we get we get a king a dog suit I + + align:start position:0% +hand we get we get a king a dog suit I + + + align:start position:0% +hand we get we get a king a dog suit I +raise from the button so we are + + align:start position:0% +raise from the button so we are + + + align:start position:0% +raise from the button so we are +committed here I mean it sucks because + + align:start position:0% +committed here I mean it sucks because + + + align:start position:0% +committed here I mean it sucks because +our hand sucks but it's way too good + + align:start position:0% +our hand sucks but it's way too good + + + align:start position:0% +our hand sucks but it's way too good +odds to call and I and I see him is + + align:start position:0% +odds to call and I and I see him is + + + align:start position:0% +odds to call and I and I see him is +nowhere near that relevant when it's + + align:start position:0% +nowhere near that relevant when it's + + + align:start position:0% +nowhere near that relevant when it's +against the small stack it's the guy + + align:start position:0% +against the small stack it's the guy + + + align:start position:0% +against the small stack it's the guy +you're trying to eliminate so we call we + + align:start position:0% +you're trying to eliminate so we call we + + + align:start position:0% +you're trying to eliminate so we call we +get pretty lucky here good + + align:start position:0% +get pretty lucky here good + + + align:start position:0% +get pretty lucky here good +good redemption for that a terrible Jack + + align:start position:0% +good redemption for that a terrible Jack + + + align:start position:0% +good redemption for that a terrible Jack +tenkan played by me okay so there's + + align:start position:0% +tenkan played by me okay so there's + + + align:start position:0% +tenkan played by me okay so there's +three players left so I see him is still + + align:start position:0% +three players left so I see him is still + + + align:start position:0% +three players left so I see him is still +very relevant we're the second stack so + + align:start position:0% +very relevant we're the second stack so + + + align:start position:0% +very relevant we're the second stack so +I were trying not to get in big on with + + align:start position:0% +I were trying not to get in big on with + + + align:start position:0% +I were trying not to get in big on with +this guy although it's less significant + + align:start position:0% +this guy although it's less significant + + + align:start position:0% +this guy although it's less significant +because this guy has still has a decent + + align:start position:0% +because this guy has still has a decent + + + align:start position:0% +because this guy has still has a decent +amount of chips like if this guy only + + align:start position:0% +amount of chips like if this guy only + + + align:start position:0% +amount of chips like if this guy only +had 50,000 chips then I would try a lot + + align:start position:0% +had 50,000 chips then I would try a lot + + + align:start position:0% +had 50,000 chips then I would try a lot +harder to avoid getting in a big pot + + align:start position:0% +harder to avoid getting in a big pot + + + align:start position:0% +harder to avoid getting in a big pot +with me my sponsor + + align:start position:0% +with me my sponsor + + + align:start position:0% +with me my sponsor +so oops so yeah so he bases and LP and + + align:start position:0% +so oops so yeah so he bases and LP and + + + align:start position:0% +so oops so yeah so he bases and LP and +bucks goes on and takes it down so + + align:start position:0% + + + + align:start position:0% + +this hand he makes it 3x and I decided I + + align:start position:0% +this hand he makes it 3x and I decided I + + + align:start position:0% +this hand he makes it 3x and I decided I +could call here with Queen six suited + + align:start position:0% +could call here with Queen six suited + + + align:start position:0% +could call here with Queen six suited +which is which is sort of gutsy I think + + align:start position:0% +which is which is sort of gutsy I think + + + align:start position:0% +which is which is sort of gutsy I think +but I think it's in position and it's + + align:start position:0% +but I think it's in position and it's + + + align:start position:0% +but I think it's in position and it's +fairly deep and being able to click ICM + + align:start position:0% +fairly deep and being able to click ICM + + + align:start position:0% +fairly deep and being able to click ICM +pressure on him is reasonable I think it + + align:start position:0% +pressure on him is reasonable I think it + + + align:start position:0% +pressure on him is reasonable I think it +could have gone either way I think + + align:start position:0% +could have gone either way I think + + + align:start position:0% +could have gone either way I think +folding is folding as a holding as I + + align:start position:0% +folding is folding as a holding as I + + + align:start position:0% +folding is folding as a holding as I +play the safer play but Queen six dude + + align:start position:0% +play the safer play but Queen six dude + + + align:start position:0% +play the safer play but Queen six dude +it is is plenty good enough here so I + + align:start position:0% +it is is plenty good enough here so I + + + align:start position:0% +it is is plenty good enough here so I +call he just checks um he might just be + + align:start position:0% +call he just checks um he might just be + + + align:start position:0% +call he just checks um he might just be +giving up on this board where there's a + + align:start position:0% +giving up on this board where there's a + + + align:start position:0% +giving up on this board where there's a +decent amount of it's fairly variety + + align:start position:0% +decent amount of it's fairly variety + + + align:start position:0% +decent amount of it's fairly variety +right so from what I said last class if + + align:start position:0% +right so from what I said last class if + + + align:start position:0% +right so from what I said last class if +the board is fairly drawing where like + + align:start position:0% +the board is fairly drawing where like + + + align:start position:0% +the board is fairly drawing where like +every hand has something if you've got + + align:start position:0% +every hand has something if you've got + + + align:start position:0% +every hand has something if you've got +absolutely nothing then there's not even + + align:start position:0% +absolutely nothing then there's not even + + + align:start position:0% +absolutely nothing then there's not even +much point to make it Bluff like if he's + + align:start position:0% +much point to make it Bluff like if he's + + + align:start position:0% +much point to make it Bluff like if he's +got east to offsuit here so he just + + align:start position:0% +got east to offsuit here so he just + + + align:start position:0% +got east to offsuit here so he just +checks in I bet if he folds so he + + align:start position:0% +checks in I bet if he folds so he + + + align:start position:0% +checks in I bet if he folds so he +probably had like east to officer some + + align:start position:0% +probably had like east to officer some + + + align:start position:0% +probably had like east to officer some +hand like that next + + align:start position:0% +hand like that next + + + align:start position:0% +hand like that next +time we get a skank um I decided to race + + align:start position:0% +time we get a skank um I decided to race + + + align:start position:0% +time we get a skank um I decided to race +small here once again so I guess this + + align:start position:0% +small here once again so I guess this + + + align:start position:0% +small here once again so I guess this +sort of protects that Jack 10 him so I + + align:start position:0% +sort of protects that Jack 10 him so I + + + align:start position:0% +sort of protects that Jack 10 him so I +mean you know if I'm doing this with + + align:start position:0% +mean you know if I'm doing this with + + + align:start position:0% +mean you know if I'm doing this with +Jack 10 I do need to get it with do it + + align:start position:0% +Jack 10 I do need to get it with do it + + + align:start position:0% +Jack 10 I do need to get it with do it +with good hands as well to protect the + + align:start position:0% +with good hands as well to protect the + + + align:start position:0% +with good hands as well to protect the +times that you have Jackson + + align:start position:0% +times that you have Jackson + + + align:start position:0% +times that you have Jackson +unfortunately he gets his correctly he + + align:start position:0% +unfortunately he gets his correctly he + + + align:start position:0% +unfortunately he gets his correctly he +he doesn't hold on I have Jack 10 in + + align:start position:0% +he doesn't hold on I have Jack 10 in + + + align:start position:0% +he doesn't hold on I have Jack 10 in +Folsom have a skink so + + align:start position:0% +Folsom have a skink so + + + align:start position:0% +Folsom have a skink so +we still take that one down and we win + + align:start position:0% +we still take that one down and we win + + + align:start position:0% +we still take that one down and we win +the blinds the next hand again so + + align:start position:0% +the blinds the next hand again so + + + align:start position:0% +the blinds the next hand again so +suddenly were were chipped leader by a + + align:start position:0% +suddenly were were chipped leader by a + + + align:start position:0% +suddenly were were chipped leader by a +decent margin after those three hands 94 + + align:start position:0% +decent margin after those three hands 94 + + + align:start position:0% +decent margin after those three hands 94 +off I'm not gonna call so sold him so + + align:start position:0% +off I'm not gonna call so sold him so + + + align:start position:0% +off I'm not gonna call so sold him so +Jackson and so once again because if I + + align:start position:0% +Jackson and so once again because if I + + + align:start position:0% +Jackson and so once again because if I +see him this guy just goes all-in + + align:start position:0% +see him this guy just goes all-in + + + align:start position:0% +see him this guy just goes all-in +knowing we can't call that much Jake sit + + align:start position:0% +knowing we can't call that much Jake sit + + + align:start position:0% +knowing we can't call that much Jake sit +down seven + + align:start position:0% +down seven + + + align:start position:0% +down seven +six offices I decided fold I think + + align:start position:0% +six offices I decided fold I think + + + align:start position:0% +six offices I decided fold I think +that's very reasonable considering they + + align:start position:0% +that's very reasonable considering they + + + align:start position:0% +that's very reasonable considering they +can just go all-in on top of that Queen + + align:start position:0% + + + + align:start position:0% + +nine Queen I've gotta walk so one thing + + align:start position:0% +nine Queen I've gotta walk so one thing + + + align:start position:0% +nine Queen I've gotta walk so one thing +I should pay attention is I do think + + align:start position:0% +I should pay attention is I do think + + + align:start position:0% +I should pay attention is I do think +these guys but the by now I've sort of + + align:start position:0% +these guys but the by now I've sort of + + + align:start position:0% +these guys but the by now I've sort of +collected enough data points of getting + + align:start position:0% +collected enough data points of getting + + + align:start position:0% +collected enough data points of getting +a lot way more often than I should or I + + align:start position:0% +a lot way more often than I should or I + + + align:start position:0% +a lot way more often than I should or I +think these it's not just a coincidence + + align:start position:0% +think these it's not just a coincidence + + + align:start position:0% +think these it's not just a coincidence +like I'm constantly confident enough + + align:start position:0% +like I'm constantly confident enough + + + align:start position:0% +like I'm constantly confident enough +that they're actually just giving me too + + align:start position:0% +that they're actually just giving me too + + + align:start position:0% +that they're actually just giving me too +many walks so when they don't give me a + + align:start position:0% +many walks so when they don't give me a + + + align:start position:0% +many walks so when they don't give me a +walk I should be I should put them on a + + align:start position:0% +walk I should be I should put them on a + + + align:start position:0% +walk I should be I should put them on a +stronger range of hands than I normally + + align:start position:0% +stronger range of hands than I normally + + + align:start position:0% +stronger range of hands than I normally +do pocket + + align:start position:0% +do pocket + + + align:start position:0% +do pocket +tens we three bet this guy again he gets + + align:start position:0% +tens we three bet this guy again he gets + + + align:start position:0% +tens we three bet this guy again he gets +away again so sixty + + align:start position:0% + + + + align:start position:0% + +off see so we've begun built good cards + + align:start position:0% +off see so we've begun built good cards + + + align:start position:0% +off see so we've begun built good cards +even though we haven't gotten too much + + align:start position:0% +even though we haven't gotten too much + + + align:start position:0% +even though we haven't gotten too much +action from them we're still won a bunch + + align:start position:0% +action from them we're still won a bunch + + + align:start position:0% +action from them we're still won a bunch +of chips from getting good cards so + + align:start position:0% + + + + align:start position:0% + +Jeff for off I'm gonna fold you this guy + + align:start position:0% +Jeff for off I'm gonna fold you this guy + + + align:start position:0% +Jeff for off I'm gonna fold you this guy +so as you can see it's fairly boring but + + align:start position:0% +so as you can see it's fairly boring but + + + align:start position:0% +so as you can see it's fairly boring but +I think this is this is how essentially + + align:start position:0% +I think this is this is how essentially + + + align:start position:0% +I think this is this is how essentially +what you essentially should happen in + + align:start position:0% +what you essentially should happen in + + + align:start position:0% +what you essentially should happen in +the final final a couple of people left + + align:start position:0% +the final final a couple of people left + + + align:start position:0% +the final final a couple of people left +in the tournament a spin-off so I decide + + align:start position:0% +in the tournament a spin-off so I decide + + + align:start position:0% +in the tournament a spin-off so I decide +to so I decided you to not go all in + + align:start position:0% +to so I decided you to not go all in + + + align:start position:0% +to so I decided you to not go all in +here I guess that would be 27 big 26 and + + align:start position:0% +here I guess that would be 27 big 26 and + + + align:start position:0% +here I guess that would be 27 big 26 and +a half big blinds which is a bit much so + + align:start position:0% +a half big blinds which is a bit much so + + + align:start position:0% +a half big blinds which is a bit much so +I decide to just raise small if he three + + align:start position:0% +I decide to just raise small if he three + + + align:start position:0% +I decide to just raise small if he three +bets if he realizes to say like 60,000 + + align:start position:0% +bets if he realizes to say like 60,000 + + + align:start position:0% +bets if he realizes to say like 60,000 +I'm always going on here and he goes + + align:start position:0% +I'm always going on here and he goes + + + align:start position:0% +I'm always going on here and he goes +all-in himself I'm probably I'm + + align:start position:0% +all-in himself I'm probably I'm + + + align:start position:0% +all-in himself I'm probably I'm +basically not folding even though it + + align:start position:0% +basically not folding even though it + + + align:start position:0% +basically not folding even though it +kind of sucks from an ICM point of view + + align:start position:0% +kind of sucks from an ICM point of view + + + align:start position:0% +kind of sucks from an ICM point of view +think he's 10 off suit is just way too + + align:start position:0% +think he's 10 off suit is just way too + + + align:start position:0% +think he's 10 off suit is just way too +good so I'm essentially just raising + + align:start position:0% +good so I'm essentially just raising + + + align:start position:0% +good so I'm essentially just raising +small looking for an action here that he + + align:start position:0% +small looking for an action here that he + + + align:start position:0% +small looking for an action here that he +folds 72 + + align:start position:0% + + + + align:start position:0% + +off suit we raise enough so + + align:start position:0% +off suit we raise enough so + + + align:start position:0% +off suit we raise enough so +OPM bucks gets a lot Queen + + align:start position:0% +OPM bucks gets a lot Queen + + + align:start position:0% +OPM bucks gets a lot Queen +3 off we get another walk which is nice + + align:start position:0% +3 off we get another walk which is nice + + + align:start position:0% +3 off we get another walk which is nice +Jack + + align:start position:0% + + + + align:start position:0% + +five off I I raise here which is + + align:start position:0% +five off I I raise here which is + + + align:start position:0% +five off I I raise here which is +definitely like an exploitative play + + align:start position:0% +definitely like an exploitative play + + + align:start position:0% +definitely like an exploitative play +it's definitely not you know like + + align:start position:0% +it's definitely not you know like + + + align:start position:0% +it's definitely not you know like +definitely from a Nash equilibrium + + align:start position:0% +definitely from a Nash equilibrium + + + align:start position:0% +definitely from a Nash equilibrium +optimal play point of view this is + + align:start position:0% +optimal play point of view this is + + + align:start position:0% +optimal play point of view this is +there's no way the optimal strategy is + + align:start position:0% +there's no way the optimal strategy is + + + align:start position:0% +there's no way the optimal strategy is +to raise a fraction of hands so big that + + align:start position:0% +to raise a fraction of hands so big that + + + align:start position:0% +to raise a fraction of hands so big that +includes jack by bob suit but I think at + + align:start position:0% +includes jack by bob suit but I think at + + + align:start position:0% +includes jack by bob suit but I think at +the time I probably told myself this guy + + align:start position:0% +the time I probably told myself this guy + + + align:start position:0% +the time I probably told myself this guy +was being overly scared even though he + + align:start position:0% +was being overly scared even though he + + + align:start position:0% +was being overly scared even though he +was playing somewhat aggressive earlier + + align:start position:0% +was playing somewhat aggressive earlier + + + align:start position:0% +was playing somewhat aggressive earlier +I'm she's maybe is over adjusting for I + + align:start position:0% +I'm she's maybe is over adjusting for I + + + align:start position:0% +I'm she's maybe is over adjusting for I +see em as being and is respecting me too + + align:start position:0% +see em as being and is respecting me too + + + align:start position:0% +see em as being and is respecting me too +much in the presence of this short step + + align:start position:0% +much in the presence of this short step + + + align:start position:0% +much in the presence of this short step +I can look at the HUD stats at the time + + align:start position:0% +I can look at the HUD stats at the time + + + align:start position:0% +I can look at the HUD stats at the time +although they won't be that accurate + + align:start position:0% +although they won't be that accurate + + + align:start position:0% +although they won't be that accurate +because + + align:start position:0% +because + + + align:start position:0% +because +they're gonna include all the hands so + + align:start position:0% +they're gonna include all the hands so + + + align:start position:0% +they're gonna include all the hands so +so that so normally I do play with all + + align:start position:0% +so that so normally I do play with all + + + align:start position:0% +so that so normally I do play with all +these numbers on so we can see that his + + align:start position:0% +these numbers on so we can see that his + + + align:start position:0% +these numbers on so we can see that his +yeah but this is it's gonna be biased + + align:start position:0% +yeah but this is it's gonna be biased + + + align:start position:0% +yeah but this is it's gonna be biased +because this includes the hands with + + align:start position:0% +because this includes the hands with + + + align:start position:0% +because this includes the hands with +with like six or seven people at the + + align:start position:0% +with like six or seven people at the + + + align:start position:0% +with like six or seven people at the +table but it says that he he + + align:start position:0% +table but it says that he he + + + align:start position:0% +table but it says that he he +calls from the big blind like only 20% + + align:start position:0% +calls from the big blind like only 20% + + + align:start position:0% +calls from the big blind like only 20% +of time but but I mean that's not a + + align:start position:0% +of time but but I mean that's not a + + + align:start position:0% +of time but but I mean that's not a +great that's not that's yeah that's + + align:start position:0% +great that's not that's yeah that's + + + align:start position:0% +great that's not that's yeah that's +gonna be biased so it doesn't it doesn't + + align:start position:0% +gonna be biased so it doesn't it doesn't + + + align:start position:0% +gonna be biased so it doesn't it doesn't +tell this too much um but + + align:start position:0% +tell this too much um but + + + align:start position:0% +tell this too much um but +I guess at the time I must have told + + align:start position:0% +I guess at the time I must have told + + + align:start position:0% +I guess at the time I must have told +myself I'm gonna try to exploit this guy + + align:start position:0% +myself I'm gonna try to exploit this guy + + + align:start position:0% +myself I'm gonna try to exploit this guy +that's the only way I can see why I + + align:start position:0% +that's the only way I can see why I + + + align:start position:0% +that's the only way I can see why I +decided to raise Jack fight off suit + + align:start position:0% +decided to raise Jack fight off suit + + + align:start position:0% +decided to raise Jack fight off suit +here so we got a call but I mean I'm + + align:start position:0% +here so we got a call but I mean I'm + + + align:start position:0% +here so we got a call but I mean I'm +gonna continuation that we do have a + + align:start position:0% +gonna continuation that we do have a + + + align:start position:0% +gonna continuation that we do have a +backdoor hard draw and this is our best + + align:start position:0% +backdoor hard draw and this is our best + + + align:start position:0% +backdoor hard draw and this is our best +chance of just winning the pot and I + + align:start position:0% +chance of just winning the pot and I + + + align:start position:0% +chance of just winning the pot and I +could I could maybe barrel on by barrel + + align:start position:0% +could I could maybe barrel on by barrel + + + align:start position:0% +could I could maybe barrel on by barrel +I mean bet again as if left on a bunch + + align:start position:0% +I mean bet again as if left on a bunch + + + align:start position:0% +I mean bet again as if left on a bunch +of turns so I just bet here he does fold + + align:start position:0% + + + + align:start position:0% + +next + + align:start position:0% +next + + + align:start position:0% +next +time with Queen 9 we open the button but + + align:start position:0% +time with Queen 9 we open the button but + + + align:start position:0% +time with Queen 9 we open the button but +we get shoved on and I guess we have to + + align:start position:0% +we get shoved on and I guess we have to + + + align:start position:0% +we get shoved on and I guess we have to +fold clean + + align:start position:0% + + + + align:start position:0% + +4 we get another block yeah so this is a + + align:start position:0% +4 we get another block yeah so this is a + + + align:start position:0% +4 we get another block yeah so this is a +feeling ridiculous it seems like we we + + align:start position:0% +feeling ridiculous it seems like we we + + + align:start position:0% +feeling ridiculous it seems like we we +literally gotten like five or six blocks + + align:start position:0% +literally gotten like five or six blocks + + + align:start position:0% +literally gotten like five or six blocks +in a row and I would guess probably we + + align:start position:0% +in a row and I would guess probably we + + + align:start position:0% +in a row and I would guess probably we +should be getting a walk like less than + + align:start position:0% +should be getting a walk like less than + + + align:start position:0% +should be getting a walk like less than +less I guess at a three and a table it's + + align:start position:0% +less I guess at a three and a table it's + + + align:start position:0% +less I guess at a three and a table it's +more often but still less than like + + align:start position:0% +more often but still less than like + + + align:start position:0% +more often but still less than like +thirty percent of the times yeah maybe + + align:start position:0% + + + + align:start position:0% + +I have been fairly active and but I did + + align:start position:0% +I have been fairly active and but I did + + + align:start position:0% +I have been fairly active and but I did +fold a bunch of I didn't fold some water + + align:start position:0% +fold a bunch of I didn't fold some water + + + align:start position:0% +fold a bunch of I didn't fold some water +line situations though like this like + + align:start position:0% +line situations though like this like + + + align:start position:0% +line situations though like this like +this Jack I think it was a different + + align:start position:0% +this Jack I think it was a different + + + align:start position:0% +this Jack I think it was a different +Jack seven times yeah maybe that's + + align:start position:0% +Jack seven times yeah maybe that's + + + align:start position:0% +Jack seven times yeah maybe that's +possible yeah good point yeah that's + + align:start position:0% +possible yeah good point yeah that's + + + align:start position:0% +possible yeah good point yeah that's +good it's good that word like I'm not + + align:start position:0% +good it's good that word like I'm not + + + align:start position:0% +good it's good that word like I'm not +complaining that we're getting a lot and + + align:start position:0% + + + + align:start position:0% + +yeah and we are the big stack so in + + align:start position:0% +yeah and we are the big stack so in + + + align:start position:0% +yeah and we are the big stack so in +general you know it is it is harder for + + align:start position:0% +general you know it is it is harder for + + + align:start position:0% +general you know it is it is harder for +them to bully us surrounded us to bully + + align:start position:0% +them to bully us surrounded us to bully + + + align:start position:0% +them to bully us surrounded us to bully +them around so it does make sense from + + align:start position:0% +them around so it does make sense from + + + align:start position:0% +them around so it does make sense from +that point of view to I still thought it + + align:start position:0% +that point of view to I still thought it + + + align:start position:0% +that point of view to I still thought it +was this kind of too many so anyway so I + + align:start position:0% +was this kind of too many so anyway so I + + + align:start position:0% +was this kind of too many so anyway so I +just continue trying to raise a lot + + align:start position:0% +just continue trying to raise a lot + + + align:start position:0% +just continue trying to raise a lot +especially against this guy so Jackie it + + align:start position:0% +especially against this guy so Jackie it + + + align:start position:0% +especially against this guy so Jackie it +offsuit we take it down jack - maybe we + + align:start position:0% +offsuit we take it down jack - maybe we + + + align:start position:0% +offsuit we take it down jack - maybe we +could have folded but by now this guy + + align:start position:0% +could have folded but by now this guy + + + align:start position:0% +could have folded but by now this guy +was getting short enough like he's + + align:start position:0% +was getting short enough like he's + + + align:start position:0% +was getting short enough like he's +blinded down from 15 and a half big + + align:start position:0% +blinded down from 15 and a half big + + + align:start position:0% +blinded down from 15 and a half big +blinds I think just 15 and a half he + + align:start position:0% +blinds I think just 15 and a half he + + + align:start position:0% +blinds I think just 15 and a half he +might have had even more before like 17 + + align:start position:0% +might have had even more before like 17 + + + align:start position:0% +might have had even more before like 17 +so he might be looking for a spot to + + align:start position:0% +so he might be looking for a spot to + + + align:start position:0% +so he might be looking for a spot to +shut down the + + align:start position:0% +shut down the + + + align:start position:0% +shut down the +unites monster actually bases small here + + align:start position:0% +unites monster actually bases small here + + + align:start position:0% +unites monster actually bases small here +and get some beef old Jack + + align:start position:0% + + + + align:start position:0% + +sticks off here we got another walk I + + align:start position:0% +sticks off here we got another walk I + + + align:start position:0% +sticks off here we got another walk I +just skipped the hands on big blinds + + align:start position:0% +just skipped the hands on big blinds + + + align:start position:0% +just skipped the hands on big blinds +nothing ever happens this way just great + + align:start position:0% +nothing ever happens this way just great + + + align:start position:0% +nothing ever happens this way just great +for us + + align:start position:0% +for us + + + align:start position:0% +for us +so pocket threes here I just go all-in + + align:start position:0% +so pocket threes here I just go all-in + + + align:start position:0% +so pocket threes here I just go all-in +so I talked about this before but what + + align:start position:0% +so I talked about this before but what + + + align:start position:0% +so I talked about this before but what +is like what's sort of them okay what's + + align:start position:0% +is like what's sort of them okay what's + + + align:start position:0% +is like what's sort of them okay what's +a problem with my what this play in some + + align:start position:0% +a problem with my what this play in some + + + align:start position:0% +a problem with my what this play in some +sense + + align:start position:0% + + + + align:start position:0% + +first + + align:start position:0% +first + + + align:start position:0% +first +employ dogs right good so say so if I + + align:start position:0% +employ dogs right good so say so if I + + + align:start position:0% +employ dogs right good so say so if I +don't do this if I just raise small I + + align:start position:0% +don't do this if I just raise small I + + + align:start position:0% +don't do this if I just raise small I +have bad reversal five dots right but + + align:start position:0% +have bad reversal five dots right but + + + align:start position:0% +have bad reversal five dots right but +the one particular issue sort of is + + align:start position:0% +the one particular issue sort of is + + + align:start position:0% +the one particular issue sort of is +every other time we've made it twenty + + align:start position:0% +every other time we've made it twenty + + + align:start position:0% +every other time we've made it twenty +five thousand and really nothing's + + align:start position:0% +five thousand and really nothing's + + + align:start position:0% +five thousand and really nothing's +changed and suddenly we could we go all + + align:start position:0% +changed and suddenly we could we go all + + + align:start position:0% +changed and suddenly we could we go all +in so it is you know it is a bit + + align:start position:0% +in so it is you know it is a bit + + + align:start position:0% +in so it is you know it is a bit +suspicious where he came she basically + + align:start position:0% +suspicious where he came she basically + + + align:start position:0% +suspicious where he came she basically +knows we have a hand that has very bad + + align:start position:0% +knows we have a hand that has very bad + + + align:start position:0% +knows we have a hand that has very bad +reverse implied odds he basically knows + + align:start position:0% +reverse implied odds he basically knows + + + align:start position:0% +reverse implied odds he basically knows +we have like pocket threes or a spore + + align:start position:0% +we have like pocket threes or a spore + + + align:start position:0% +we have like pocket threes or a spore +offsuit or something like that but it's + + align:start position:0% +offsuit or something like that but it's + + + align:start position:0% +offsuit or something like that but it's +still sort of hard for him to exploit + + align:start position:0% +still sort of hard for him to exploit + + + align:start position:0% +still sort of hard for him to exploit +like you know I mean sure you can call + + align:start position:0% +like you know I mean sure you can call + + + align:start position:0% +like you know I mean sure you can call +like ace nine and exploit us but I mean + + align:start position:0% +like ace nine and exploit us but I mean + + + align:start position:0% +like ace nine and exploit us but I mean +ace nine is already a great hand or you + + align:start position:0% +ace nine is already a great hand or you + + + align:start position:0% +ace nine is already a great hand or you +know you can call the pocket for is an + + align:start position:0% +know you can call the pocket for is an + + + align:start position:0% +know you can call the pocket for is an +exploit us but it's not that easy to get + + align:start position:0% +exploit us but it's not that easy to get + + + align:start position:0% +exploit us but it's not that easy to get +dealt pocket phones order a bit or a + + align:start position:0% +dealt pocket phones order a bit or a + + + align:start position:0% +dealt pocket phones order a bit or a +better pair of the pocket fours so so + + align:start position:0% +better pair of the pocket fours so so + + + align:start position:0% +better pair of the pocket fours so so +here yeah even though you know against a + + align:start position:0% +here yeah even though you know against a + + + align:start position:0% +here yeah even though you know against a +good player he sort of knows my range is + + align:start position:0% +good player he sort of knows my range is + + + align:start position:0% +good player he sort of knows my range is +a very small specific number of hands + + align:start position:0% +a very small specific number of hands + + + align:start position:0% +a very small specific number of hands +it's still hard for him do like you + + align:start position:0% +it's still hard for him do like you + + + align:start position:0% +it's still hard for him do like you +can't really just call Jack ten suited + + align:start position:0% +can't really just call Jack ten suited + + + align:start position:0% +can't really just call Jack ten suited +here maybe he can but probably like Jack + + align:start position:0% +here maybe he can but probably like Jack + + + align:start position:0% +here maybe he can but probably like Jack +nine suited or queen seven suited you + + align:start position:0% +nine suited or queen seven suited you + + + align:start position:0% +nine suited or queen seven suited you +can't call because it's there's there's + + align:start position:0% +can't call because it's there's there's + + + align:start position:0% +can't call because it's there's there's +still an off chance we have like three 9 + + align:start position:0% +still an off chance we have like three 9 + + + align:start position:0% +still an off chance we have like three 9 +offsuit or something so uh so + + align:start position:0% +offsuit or something so uh so + + + align:start position:0% +offsuit or something so uh so +anyway so he does fold but it definitely + + align:start position:0% +anyway so he does fold but it definitely + + + align:start position:0% +anyway so he does fold but it definitely +raises suspicion Jack ten off so Jack's + + align:start position:0% +raises suspicion Jack ten off so Jack's + + + align:start position:0% +raises suspicion Jack ten off so Jack's +enough we just go all in here so I think + + align:start position:0% +enough we just go all in here so I think + + + align:start position:0% +enough we just go all in here so I think +so + + align:start position:0% +so + + + align:start position:0% +so +this is actually important so but so + + align:start position:0% +this is actually important so but so + + + align:start position:0% +this is actually important so but so +normally how you just raise from the + + align:start position:0% +normally how you just raise from the + + + align:start position:0% +normally how you just raise from the +button but by now the big blind has + + align:start position:0% +button but by now the big blind has + + + align:start position:0% +button but by now the big blind has +gotten so sort that I'm willing to just + + align:start position:0% +gotten so sort that I'm willing to just + + + align:start position:0% +gotten so sort that I'm willing to just +go all in because the big blind is sort + + align:start position:0% +go all in because the big blind is sort + + + align:start position:0% +go all in because the big blind is sort +of sort enough for even if he picks up a + + align:start position:0% +of sort enough for even if he picks up a + + + align:start position:0% +of sort enough for even if he picks up a +hand and calls and beats me I'm still + + align:start position:0% +hand and calls and beats me I'm still + + + align:start position:0% +hand and calls and beats me I'm still +the chip leader even if that happens so + + align:start position:0% +the chip leader even if that happens so + + + align:start position:0% +the chip leader even if that happens so +the ICM is doesn't hurt me that much + + align:start position:0% +the ICM is doesn't hurt me that much + + + align:start position:0% +the ICM is doesn't hurt me that much +because yeah and also just the fact that + + align:start position:0% +because yeah and also just the fact that + + + align:start position:0% +because yeah and also just the fact that +I'm risking less and also not the other + + align:start position:0% +I'm risking less and also not the other + + + align:start position:0% +I'm risking less and also not the other +important thing of the big blind getting + + align:start position:0% +important thing of the big blind getting + + + align:start position:0% +important thing of the big blind getting +short is now the small blind is much + + align:start position:0% +short is now the small blind is much + + + align:start position:0% +short is now the small blind is much +less incentivized to gamble than before + + align:start position:0% +less incentivized to gamble than before + + + align:start position:0% +less incentivized to gamble than before +like before it when the big blank had + + align:start position:0% +like before it when the big blank had + + + align:start position:0% +like before it when the big blank had +180 K you know he he was in symptom isin + + align:start position:0% +180 K you know he he was in symptom isin + + + align:start position:0% +180 K you know he he was in symptom isin +gamble against me because it's + + align:start position:0% +gamble against me because it's + + + align:start position:0% +gamble against me because it's +not that easy to wait for the big blind + + align:start position:0% +not that easy to wait for the big blind + + + align:start position:0% +not that easy to wait for the big blind +you bust but now that the big mine only + + align:start position:0% +you bust but now that the big mine only + + + align:start position:0% +you bust but now that the big mine only +has ten K it's easier to sort of just + + align:start position:0% +has ten K it's easier to sort of just + + + align:start position:0% +has ten K it's easier to sort of just +wait and hope that he busts so basically + + align:start position:0% +wait and hope that he busts so basically + + + align:start position:0% +wait and hope that he busts so basically +I see M becomes more favorable in both + + align:start position:0% +I see M becomes more favorable in both + + + align:start position:0% +I see M becomes more favorable in both +cases and something I think is very good + + align:start position:0% +cases and something I think is very good + + + align:start position:0% +cases and something I think is very good +now with the Saxons so we do shove and + + align:start position:0% +now with the Saxons so we do shove and + + + align:start position:0% +now with the Saxons so we do shove and +we take it down 92 + + align:start position:0% +we take it down 92 + + + align:start position:0% +we take it down 92 +off so no one usually wants our blinds + + align:start position:0% +off so no one usually wants our blinds + + + align:start position:0% +off so no one usually wants our blinds +but then they both want our blinds I'll + + align:start position:0% +but then they both want our blinds I'll + + + align:start position:0% +but then they both want our blinds I'll +be unboxing stem so + + align:start position:0% + + + + align:start position:0% + +East to I just go all in here basically + + align:start position:0% +East to I just go all in here basically + + + align:start position:0% +East to I just go all in here basically +same justification as the pocket threes + + align:start position:0% +same justification as the pocket threes + + + align:start position:0% +same justification as the pocket threes +eats + + align:start position:0% +eats + + + align:start position:0% +eats +of it off I think I probably should have + + align:start position:0% +of it off I think I probably should have + + + align:start position:0% +of it off I think I probably should have +raised this we + + align:start position:0% +raised this we + + + align:start position:0% +raised this we +all in honesty might not be that bad I'd + + align:start position:0% +all in honesty might not be that bad I'd + + + align:start position:0% +all in honesty might not be that bad I'd +have to do an exact calculation but I + + align:start position:0% +have to do an exact calculation but I + + + align:start position:0% +have to do an exact calculation but I +think probably I mean it's not it's a + + align:start position:0% +think probably I mean it's not it's a + + + align:start position:0% +think probably I mean it's not it's a +pretty bad hand but I think probably I + + align:start position:0% +pretty bad hand but I think probably I + + + align:start position:0% +pretty bad hand but I think probably I +shouldn't be folding given that I'm the + + align:start position:0% +shouldn't be folding given that I'm the + + + align:start position:0% +shouldn't be folding given that I'm the +big stack and given that they both been + + align:start position:0% +big stack and given that they both been + + + align:start position:0% +big stack and given that they both been +giving me lots of respect but I fold + + align:start position:0% +giving me lots of respect but I fold + + + align:start position:0% +giving me lots of respect but I fold +which can't be a big mistake but I think + + align:start position:0% +which can't be a big mistake but I think + + + align:start position:0% +which can't be a big mistake but I think +probably I shouldn't have folded the + + align:start position:0% +probably I shouldn't have folded the + + + align:start position:0% +probably I shouldn't have folded the +next handout the mbox goes on and we + + align:start position:0% +next handout the mbox goes on and we + + + align:start position:0% +next handout the mbox goes on and we +fold next + + align:start position:0% + + + + align:start position:0% + +thing we get 8 7 suited so by now this + + align:start position:0% +thing we get 8 7 suited so by now this + + + align:start position:0% +thing we get 8 7 suited so by now this +guy be my sponsor so we've just won + + align:start position:0% +guy be my sponsor so we've just won + + + align:start position:0% +guy be my sponsor so we've just won +enough pots where this guy is also sort + + align:start position:0% +enough pots where this guy is also sort + + + align:start position:0% +enough pots where this guy is also sort +of short now so it's a pretty good + + align:start position:0% +of short now so it's a pretty good + + + align:start position:0% +of short now so it's a pretty good +situation for us from an ICM perspective + + align:start position:0% +situation for us from an ICM perspective + + + align:start position:0% +situation for us from an ICM perspective +they're both kind of short enough where + + align:start position:0% +they're both kind of short enough where + + + align:start position:0% +they're both kind of short enough where +we can just go all-in preflop very often + + align:start position:0% +we can just go all-in preflop very often + + + align:start position:0% +we can just go all-in preflop very often +and they have to fold quite often tens + + align:start position:0% +and they have to fold quite often tens + + + align:start position:0% +and they have to fold quite often tens +evanov is a bit too weak but I decided + + align:start position:0% +evanov is a bit too weak but I decided + + + align:start position:0% +evanov is a bit too weak but I decided +raise but yeah this is a bit + + align:start position:0% +raise but yeah this is a bit + + + align:start position:0% +raise but yeah this is a bit +inconsistent play for my part because I + + align:start position:0% +inconsistent play for my part because I + + + align:start position:0% +inconsistent play for my part because I +think for most purposes 8:7 off is a + + align:start position:0% +think for most purposes 8:7 off is a + + + align:start position:0% +think for most purposes 8:7 off is a +better hand than 10 7 off but for some + + align:start position:0% +better hand than 10 7 off but for some + + + align:start position:0% +better hand than 10 7 off but for some +reason I raise 10 7 off and fold 8 7 off + + align:start position:0% +reason I raise 10 7 off and fold 8 7 off + + + align:start position:0% +reason I raise 10 7 off and fold 8 7 off +these + + align:start position:0% +these + + + align:start position:0% +these +5 suited we get a walk again Queen 5 off + + align:start position:0% +5 suited we get a walk again Queen 5 off + + + align:start position:0% +5 suited we get a walk again Queen 5 off +yeah so I just go all in here I mean + + align:start position:0% +yeah so I just go all in here I mean + + + align:start position:0% +yeah so I just go all in here I mean +yeah this is so this is definitely not a + + align:start position:0% +yeah this is so this is definitely not a + + + align:start position:0% +yeah this is so this is definitely not a +plus ship EVD all in but once again I + + align:start position:0% +plus ship EVD all in but once again I + + + align:start position:0% +plus ship EVD all in but once again I +think I see him by now is relevant + + align:start position:0% +think I see him by now is relevant + + + align:start position:0% +think I see him by now is relevant +enough where um it's fine because he + + align:start position:0% +enough where um it's fine because he + + + align:start position:0% +enough where um it's fine because he +just have to fold we + + align:start position:0% +just have to fold we + + + align:start position:0% +just have to fold we +see it down 10 6 off I decided fold big + + align:start position:0% +see it down 10 6 off I decided fold big + + + align:start position:0% +see it down 10 6 off I decided fold big +blank gets a walk get + + align:start position:0% +blank gets a walk get + + + align:start position:0% +blank gets a walk get +a walk with six deuce pretty good ace + + align:start position:0% +a walk with six deuce pretty good ace + + + align:start position:0% +a walk with six deuce pretty good ace +two off once again we just go on they + + align:start position:0% +two off once again we just go on they + + + align:start position:0% +two off once again we just go on they +fold pocket kings Sybase I yeah so this + + align:start position:0% +fold pocket kings Sybase I yeah so this + + + align:start position:0% +fold pocket kings Sybase I yeah so this +is a bit suspicious again normally I've + + align:start position:0% +is a bit suspicious again normally I've + + + align:start position:0% +is a bit suspicious again normally I've +been going all in you know he raises + + align:start position:0% +been going all in you know he raises + + + align:start position:0% +been going all in you know he raises +small obviously yes five kings so + + align:start position:0% +small obviously yes five kings so + + + align:start position:0% +small obviously yes five kings so +yeah I mean that's basically true but I + + align:start position:0% +yeah I mean that's basically true but I + + + align:start position:0% +yeah I mean that's basically true but I +mean also I think I will do this with + + align:start position:0% +mean also I think I will do this with + + + align:start position:0% +mean also I think I will do this with +some of the weakest hands that I'm not + + align:start position:0% +some of the weakest hands that I'm not + + + align:start position:0% +some of the weakest hands that I'm not +willing to gamble and with but still + + align:start position:0% +willing to gamble and with but still + + + align:start position:0% +willing to gamble and with but still +want to raise like maybe like something + + align:start position:0% +want to raise like maybe like something + + + align:start position:0% +want to raise like maybe like something +like nine seven offsuit maybe but + + align:start position:0% +like nine seven offsuit maybe but + + + align:start position:0% +like nine seven offsuit maybe but +we + + align:start position:0% + + + + align:start position:0% + +take it down so if he goes on we fold + + align:start position:0% +take it down so if he goes on we fold + + + align:start position:0% +take it down so if he goes on we fold +Jack to off suit Queens + + align:start position:0% + + + + align:start position:0% + +pursued and go all-in so I'm gonna go + + align:start position:0% +pursued and go all-in so I'm gonna go + + + align:start position:0% +pursued and go all-in so I'm gonna go +through this fairly faster there's a lot + + align:start position:0% +through this fairly faster there's a lot + + + align:start position:0% +through this fairly faster there's a lot +of the same same stuff six five off we + + align:start position:0% +of the same same stuff six five off we + + + align:start position:0% +of the same same stuff six five off we +we fold these yeah by now they're sort + + align:start position:0% +we fold these yeah by now they're sort + + + align:start position:0% +we fold these yeah by now they're sort +of short enough where they might + + align:start position:0% +of short enough where they might + + + align:start position:0% +of short enough where they might +actually just call us pretty often so + + align:start position:0% +actually just call us pretty often so + + + align:start position:0% +actually just call us pretty often so +iPhone six five off so here pocket + + align:start position:0% +iPhone six five off so here pocket + + + align:start position:0% +iPhone six five off so here pocket +threes holds against Queen Jack so that + + align:start position:0% +threes holds against Queen Jack so that + + + align:start position:0% +threes holds against Queen Jack so that +so this isn't so this is an extreme ICM + + align:start position:0% +so this isn't so this is an extreme ICM + + + align:start position:0% +so this isn't so this is an extreme ICM +spot so he calls here and he does double + + align:start position:0% +spot so he calls here and he does double + + + align:start position:0% +spot so he calls here and he does double +up so the next hand we are we do have an + + align:start position:0% +up so the next hand we are we do have an + + + align:start position:0% +up so the next hand we are we do have an +extreme ICM spot because this guy only + + align:start position:0% +extreme ICM spot because this guy only + + + align:start position:0% +extreme ICM spot because this guy only +has one big blind so essentially the + + align:start position:0% +has one big blind so essentially the + + + align:start position:0% +has one big blind so essentially the +correct strategy is going to be hein + + align:start position:0% +correct strategy is going to be hein + + + align:start position:0% +correct strategy is going to be hein +socially shove any two cards and he's + + align:start position:0% +socially shove any two cards and he's + + + align:start position:0% +socially shove any two cards and he's +only socially call I would guess like + + align:start position:0% +only socially call I would guess like + + + align:start position:0% +only socially call I would guess like +maybe like the top top seminary percent + + align:start position:0% +maybe like the top top seminary percent + + + align:start position:0% +maybe like the top top seminary percent +of hands in the situation he normally + + align:start position:0% +of hands in the situation he normally + + + align:start position:0% +of hands in the situation he normally +shouldn't be calling like tops thirty or + + align:start position:0% +shouldn't be calling like tops thirty or + + + align:start position:0% +shouldn't be calling like tops thirty or +something so I just go all-in and like + + align:start position:0% +something so I just go all-in and like + + + align:start position:0% +something so I just go all-in and like +the FES East to off suit I'm certain es + + align:start position:0% +the FES East to off suit I'm certain es + + + align:start position:0% +the FES East to off suit I'm certain es +people like even if he has like say king + + align:start position:0% +people like even if he has like say king + + + align:start position:0% +people like even if he has like say king +queen and I turn up my hand and show him + + align:start position:0% +queen and I turn up my hand and show him + + + align:start position:0% +queen and I turn up my hand and show him +Jack seven he probably still has to fold + + align:start position:0% +Jack seven he probably still has to fold + + + align:start position:0% +Jack seven he probably still has to fold +just + + align:start position:0% +just + + + align:start position:0% +just +because he really can't bust lady yeah I + + align:start position:0% +because he really can't bust lady yeah I + + + align:start position:0% +because he really can't bust lady yeah I +haven't done the exact math but you know + + align:start position:0% +haven't done the exact math but you know + + + align:start position:0% +haven't done the exact math but you know +I wouldn't be that surprised if he told + + align:start position:0% +I wouldn't be that surprised if he told + + + align:start position:0% +I wouldn't be that surprised if he told +me like pocket nines is a fold for him I + + align:start position:0% +me like pocket nines is a fold for him I + + + align:start position:0% +me like pocket nines is a fold for him I +wouldn't be that surprised so + + align:start position:0% +wouldn't be that surprised so + + + align:start position:0% +wouldn't be that surprised so +yeah so + + align:start position:0% + + + + align:start position:0% + +so once again I go all-in because this + + align:start position:0% +so once again I go all-in because this + + + align:start position:0% +so once again I go all-in because this +guy probably can't call so + + align:start position:0% + + + + align:start position:0% + +so you do okay so yeah we went we + + align:start position:0% +so you do okay so yeah we went we + + + align:start position:0% +so you do okay so yeah we went we +waiting at ASIC we know we're just quite + + align:start position:0% +waiting at ASIC we know we're just quite + + + align:start position:0% +waiting at ASIC we know we're just quite +it's kind of crazy that he picked up a + + align:start position:0% +it's kind of crazy that he picked up a + + + align:start position:0% +it's kind of crazy that he picked up a +nice clean with one big blinds + + align:start position:0% +nice clean with one big blinds + + + align:start position:0% +nice clean with one big blinds +some some players like to do do this + + align:start position:0% +some some players like to do do this + + + align:start position:0% +some some players like to do do this +thing called like cooperative play to + + align:start position:0% +thing called like cooperative play to + + + align:start position:0% +thing called like cooperative play to +get the big blind to bust so this is in + + align:start position:0% +get the big blind to bust so this is in + + + align:start position:0% +get the big blind to bust so this is in +the history of poker + + align:start position:0% +the history of poker + + + align:start position:0% +the history of poker +it's sort of what was almost customary + + align:start position:0% +it's sort of what was almost customary + + + align:start position:0% +it's sort of what was almost customary +for the players in if you have chips in + + align:start position:0% +for the players in if you have chips in + + + align:start position:0% +for the players in if you have chips in +here to basically just all agree to just + + align:start position:0% +here to basically just all agree to just + + + align:start position:0% +here to basically just all agree to just +call and not raise each other and to + + align:start position:0% +call and not raise each other and to + + + align:start position:0% +call and not raise each other and to +maximize their chances of busting the + + align:start position:0% +maximize their chances of busting the + + + align:start position:0% +maximize their chances of busting the +big blind it's sort of a form of + + align:start position:0% +big blind it's sort of a form of + + + align:start position:0% +big blind it's sort of a form of +cheating in some sense it's like + + align:start position:0% +cheating in some sense it's like + + + align:start position:0% +cheating in some sense it's like +collusion in some sense but it's + + align:start position:0% +collusion in some sense but it's + + + align:start position:0% +collusion in some sense but it's +customary maybe like five six years ago + + align:start position:0% +customary maybe like five six years ago + + + align:start position:0% +customary maybe like five six years ago +we're never going to do this because it + + align:start position:0% +we're never going to do this because it + + + align:start position:0% +we're never going to do this because it +sort of benefits everyone else it sort + + align:start position:0% +sort of benefits everyone else it sort + + + align:start position:0% +sort of benefits everyone else it sort +of benefits all of these guys if they + + align:start position:0% +of benefits all of these guys if they + + + align:start position:0% +of benefits all of these guys if they +all agree to do this and it + + align:start position:0% +all agree to do this and it + + + align:start position:0% +all agree to do this and it +just maximizes the chances that the big + + align:start position:0% +just maximizes the chances that the big + + + align:start position:0% +just maximizes the chances that the big +blind is eliminated but the issue with + + align:start position:0% +blind is eliminated but the issue with + + + align:start position:0% +blind is eliminated but the issue with +this is unfortunately + + align:start position:0% +this is unfortunately + + + align:start position:0% +this is unfortunately +unfortunately + + align:start position:0% +unfortunately + + + align:start position:0% +unfortunately +there is an option to be selfish right + + align:start position:0% +there is an option to be selfish right + + + align:start position:0% +there is an option to be selfish right +unfortunately if you know if we both + + align:start position:0% +unfortunately if you know if we both + + + align:start position:0% +unfortunately if you know if we both +trusted each other completely we could + + align:start position:0% +trusted each other completely we could + + + align:start position:0% +trusted each other completely we could +pollute and be like okay we're just + + align:start position:0% +pollute and be like okay we're just + + + align:start position:0% +pollute and be like okay we're just +gonna call check down every flop turn + + align:start position:0% +gonna call check down every flop turn + + + align:start position:0% +gonna call check down every flop turn +and River no matter what to match so + + align:start position:0% +and River no matter what to match so + + + align:start position:0% +and River no matter what to match so +that we can both see the river with any + + align:start position:0% +that we can both see the river with any + + + align:start position:0% +that we can both see the river with any +two cards and maximize the chances of + + align:start position:0% +two cards and maximize the chances of + + + align:start position:0% +two cards and maximize the chances of +busting this guy the issue with this is + + align:start position:0% +busting this guy the issue with this is + + + align:start position:0% +busting this guy the issue with this is +you know players when you play a game + + align:start position:0% +you know players when you play a game + + + align:start position:0% +you know players when you play a game +you're selfish right and you want to you + + align:start position:0% +you're selfish right and you want to you + + + align:start position:0% +you're selfish right and you want to you +know if there is an opportunity to bet + + align:start position:0% +know if there is an opportunity to bet + + + align:start position:0% +know if there is an opportunity to bet +because you have a good hand you're + + align:start position:0% +because you have a good hand you're + + + align:start position:0% +because you have a good hand you're +gonna want to bet more like you know if + + align:start position:0% +gonna want to bet more like you know if + + + align:start position:0% +gonna want to bet more like you know if +there's a draw and you have a good hand + + align:start position:0% +there's a draw and you have a good hand + + + align:start position:0% +there's a draw and you have a good hand +you wanna bet you get the other guy to + + align:start position:0% +you wanna bet you get the other guy to + + + align:start position:0% +you wanna bet you get the other guy to +fold and basically from a game theoretic + + align:start position:0% +fold and basically from a game theoretic + + + align:start position:0% +fold and basically from a game theoretic +perspective since we have these options + + align:start position:0% +perspective since we have these options + + + align:start position:0% +perspective since we have these options +there's no way for us to essentially + + align:start position:0% +there's no way for us to essentially + + + align:start position:0% +there's no way for us to essentially +agree that we're gonna just check down + + align:start position:0% +agree that we're gonna just check down + + + align:start position:0% +agree that we're gonna just check down +and see the river which is why I + + align:start position:0% +and see the river which is why I + + + align:start position:0% +and see the river which is why I +consider a collision if players actually + + align:start position:0% +consider a collision if players actually + + + align:start position:0% +consider a collision if players actually +use um so + + align:start position:0% +use um so + + + align:start position:0% +use um so +nonetheless I do the I do the most + + align:start position:0% +nonetheless I do the I do the most + + + align:start position:0% +nonetheless I do the I do the most +selfish line which is just go all-in + + align:start position:0% +selfish line which is just go all-in + + + align:start position:0% +selfish line which is just go all-in +but yeah this guy was my best friend and + + align:start position:0% +but yeah this guy was my best friend and + + + align:start position:0% +but yeah this guy was my best friend and +I wanted to do cheat then I could just + + align:start position:0% +I wanted to do cheat then I could just + + + align:start position:0% +I wanted to do cheat then I could just +call and let him call and then just + + align:start position:0% +call and let him call and then just + + + align:start position:0% +call and let him call and then just +check it down even if I flop the nut + + align:start position:0% +check it down even if I flop the nut + + + align:start position:0% +check it down even if I flop the nut +flush but + + align:start position:0% +flush but + + + align:start position:0% +flush but +okay + + align:start position:0% + + + + align:start position:0% + +so now it's heads up and so + + align:start position:0% +so now it's heads up and so + + + align:start position:0% +so now it's heads up and so +I'll try to show every hand okay + + align:start position:0% +I'll try to show every hand okay + + + align:start position:0% +I'll try to show every hand okay +so now I see him doesn't matter but it + + align:start position:0% +so now I see him doesn't matter but it + + + align:start position:0% +so now I see him doesn't matter but it +would be good to show a bit of heads-up + + align:start position:0% +would be good to show a bit of heads-up + + + align:start position:0% +would be good to show a bit of heads-up +play because I don't think we've done + + align:start position:0% +play because I don't think we've done + + + align:start position:0% +play because I don't think we've done +too much heads-up play in this class so + + align:start position:0% +too much heads-up play in this class so + + + align:start position:0% +too much heads-up play in this class so +we call here and we + + align:start position:0% +we call here and we + + + align:start position:0% +we call here and we +check he makes it 32 and I decided check + + align:start position:0% +check he makes it 32 and I decided check + + + align:start position:0% +check he makes it 32 and I decided check +raise check raise bluff this flop I + + align:start position:0% +raise check raise bluff this flop I + + + align:start position:0% +raise check raise bluff this flop I +think I think it's close I mean I think + + align:start position:0% +think I think it's close I mean I think + + + align:start position:0% +think I think it's close I mean I think +I probably shouldn't be folding I think + + align:start position:0% +I probably shouldn't be folding I think + + + align:start position:0% +I probably shouldn't be folding I think +Jack's exuded it just has too many + + align:start position:0% +Jack's exuded it just has too many + + + align:start position:0% +Jack's exuded it just has too many +backdoor draws on this spot to ever fold + + align:start position:0% +backdoor draws on this spot to ever fold + + + align:start position:0% +backdoor draws on this spot to ever fold +just as part of us part of my strategy I + + align:start position:0% +just as part of us part of my strategy I + + + align:start position:0% +just as part of us part of my strategy I +think I decided that I wanted my + + align:start position:0% +think I decided that I wanted my + + + align:start position:0% +think I decided that I wanted my +strategy to to be I'm gonna raise good + + align:start position:0% +strategy to to be I'm gonna raise good + + + align:start position:0% +strategy to to be I'm gonna raise good +hands like eights and fours and then I'm + + align:start position:0% +hands like eights and fours and then I'm + + + align:start position:0% +hands like eights and fours and then I'm +gonna also raise hands with lots of + + align:start position:0% +gonna also raise hands with lots of + + + align:start position:0% +gonna also raise hands with lots of +backdrops like Jack's six cards so I + + align:start position:0% +backdrops like Jack's six cards so I + + + align:start position:0% +backdrops like Jack's six cards so I +decided to do this so + + align:start position:0% +decided to do this so + + + align:start position:0% +decided to do this so +unfortunately he goes all and so we fold + + align:start position:0% +unfortunately he goes all and so we fold + + + align:start position:0% +unfortunately he goes all and so we fold +it doesn't quite work so we + + align:start position:0% +it doesn't quite work so we + + + align:start position:0% +it doesn't quite work so we +turn off me raise Oh so + + align:start position:0% +turn off me raise Oh so + + + align:start position:0% +turn off me raise Oh so +one thing I should say is I think most + + align:start position:0% +one thing I should say is I think most + + + align:start position:0% +one thing I should say is I think most +of you know this but once a tournament + + align:start position:0% +of you know this but once a tournament + + + align:start position:0% +of you know this but once a tournament +gets heads up and it's just the small + + align:start position:0% +gets heads up and it's just the small + + + align:start position:0% +gets heads up and it's just the small +wine and the big blind the small blind + + align:start position:0% +wine and the big blind the small blind + + + align:start position:0% +wine and the big blind the small blind +is actually has position so normally + + align:start position:0% +is actually has position so normally + + + align:start position:0% +is actually has position so normally +when it's small line against big blind a + + align:start position:0% +when it's small line against big blind a + + + align:start position:0% +when it's small line against big blind a +big volume has position post-flop but + + align:start position:0% +big volume has position post-flop but + + + align:start position:0% +big volume has position post-flop but +when it ends up at a small line you + + align:start position:0% +when it ends up at a small line you + + + align:start position:0% +when it ends up at a small line you +actually have position so you're very + + align:start position:0% +actually have position so you're very + + + align:start position:0% +actually have position so you're very +strongly incentivized to play in the + + align:start position:0% +strongly incentivized to play in the + + + align:start position:0% +strongly incentivized to play in the +spotlight it's just by far the better + + align:start position:0% +spotlight it's just by far the better + + + align:start position:0% +spotlight it's just by far the better +position because um because you have + + align:start position:0% +position because um because you have + + + align:start position:0% +position because um because you have +position and you'll be put in less of a + + align:start position:0% +position and you'll be put in less of a + + + align:start position:0% +position and you'll be put in less of a +blind so + + align:start position:0% +blind so + + + align:start position:0% +blind so +another cheat that so I'm teaching you + + align:start position:0% +another cheat that so I'm teaching you + + + align:start position:0% +another cheat that so I'm teaching you +guys all these different sheets another + + align:start position:0% +guys all these different sheets another + + + align:start position:0% +guys all these different sheets another +cheat that people used to do it's not + + align:start position:0% +cheat that people used to do it's not + + + align:start position:0% +cheat that people used to do it's not +really a cheat but another sort of angle + + align:start position:0% +really a cheat but another sort of angle + + + align:start position:0% +really a cheat but another sort of angle +shootin people used to do back in the + + align:start position:0% +shootin people used to do back in the + + + align:start position:0% +shootin people used to do back in the +day is there would be people who like + + align:start position:0% +day is there would be people who like + + + align:start position:0% +day is there would be people who like +normally play pretty low stakes let's + + align:start position:0% +normally play pretty low stakes let's + + + align:start position:0% +normally play pretty low stakes let's +say like 25 cent 50 cent and then they + + align:start position:0% +say like 25 cent 50 cent and then they + + + align:start position:0% +say like 25 cent 50 cent and then they +would play they would sit at these $25 + + align:start position:0% +would play they would sit at these $25 + + + align:start position:0% +would play they would sit at these $25 +$50 tables so like where the blinds are + + align:start position:0% +$50 tables so like where the blinds are + + + align:start position:0% +$50 tables so like where the blinds are +play five bucks 50 bucks which is pretty + + align:start position:0% +play five bucks 50 bucks which is pretty + + + align:start position:0% +play five bucks 50 bucks which is pretty +which is really high stakes for them and + + align:start position:0% +which is really high stakes for them and + + + align:start position:0% +which is really high stakes for them and +you know like that it's something they + + align:start position:0% +you know like that it's something they + + + align:start position:0% +you know like that it's something they +really don't have the bankroll to gamble + + align:start position:0% +really don't have the bankroll to gamble + + + align:start position:0% +really don't have the bankroll to gamble +all that but their strategy basically is + + align:start position:0% +all that but their strategy basically is + + + align:start position:0% +all that but their strategy basically is +if you're the first to sit down you get + + align:start position:0% +if you're the first to sit down you get + + + align:start position:0% +if you're the first to sit down you get +to be the dealer on the first hand so + + align:start position:0% +to be the dealer on the first hand so + + + align:start position:0% +to be the dealer on the first hand so +the strategy is basically just um sit + + align:start position:0% +the strategy is basically just um sit + + + align:start position:0% +the strategy is basically just um sit +there and then wait for someone else to + + align:start position:0% +there and then wait for someone else to + + + align:start position:0% +there and then wait for someone else to +sit down and then play the first hand as + + align:start position:0% +sit down and then play the first hand as + + + align:start position:0% +sit down and then play the first hand as +the dealer or they have a huge advantage + + align:start position:0% +the dealer or they have a huge advantage + + + align:start position:0% +the dealer or they have a huge advantage +they ain't just raised and usually the + + align:start position:0% +they ain't just raised and usually the + + + align:start position:0% +they ain't just raised and usually the +other guy will fold and they'll wait + + align:start position:0% +other guy will fold and they'll wait + + + align:start position:0% +other guy will fold and they'll wait +fifty bucks is a huge deal to them and + + align:start position:0% +fifty bucks is a huge deal to them and + + + align:start position:0% +fifty bucks is a huge deal to them and +another's leave after my first hand so + + align:start position:0% +another's leave after my first hand so + + + align:start position:0% +another's leave after my first hand so +this is something that happened quite a + + align:start position:0% +this is something that happened quite a + + + align:start position:0% +this is something that happened quite a +lot and then so you know my friends and + + align:start position:0% +lot and then so you know my friends and + + + align:start position:0% +lot and then so you know my friends and +I we talked about playing a crazy + + align:start position:0% +I we talked about playing a crazy + + + align:start position:0% +I we talked about playing a crazy +strategy where you would sit down + + align:start position:0% +strategy where you would sit down + + + align:start position:0% +strategy where you would sit down +knowing this is what the other guy's + + align:start position:0% +knowing this is what the other guy's + + + align:start position:0% +knowing this is what the other guy's +gonna do and then sit down with them and + + align:start position:0% +gonna do and then sit down with them and + + + align:start position:0% +gonna do and then sit down with them and +you know we would have the capital to + + align:start position:0% +you know we would have the capital to + + + align:start position:0% +you know we would have the capital to +take on risk and then we would basically + + align:start position:0% +take on risk and then we would basically + + + align:start position:0% +take on risk and then we would basically +just play the first name extremely + + align:start position:0% +just play the first name extremely + + + align:start position:0% +just play the first name extremely +aggressively yeah you don't worry about + + align:start position:0% +aggressively yeah you don't worry about + + + align:start position:0% +aggressively yeah you don't worry about +the guy has to pull those of the time + + align:start position:0% +the guy has to pull those of the time + + + align:start position:0% +the guy has to pull those of the time +because if he calls that's all his money + + align:start position:0% +because if he calls that's all his money + + + align:start position:0% +because if he calls that's all his money +up site so so yeah it lets do a lot of + + align:start position:0% +up site so so yeah it lets do a lot of + + + align:start position:0% +up site so so yeah it lets do a lot of +weird dynamics but + + align:start position:0% +weird dynamics but + + + align:start position:0% +weird dynamics but +okay so here we have but this is a turn + + align:start position:0% +okay so here we have but this is a turn + + + align:start position:0% +okay so here we have but this is a turn +this is I chose tournaments not cash + + align:start position:0% +this is I chose tournaments not cash + + + align:start position:0% +this is I chose tournaments not cash +gangsters there's fewer ways to do these + + align:start position:0% +gangsters there's fewer ways to do these + + + align:start position:0% +gangsters there's fewer ways to do these +commuters cheats so Queen ten we raise + + align:start position:0% +commuters cheats so Queen ten we raise + + + align:start position:0% +commuters cheats so Queen ten we raise +we take it down next + + align:start position:0% +we take it down next + + + align:start position:0% +we take it down next +time we get East Queen certain so + + align:start position:0% +time we get East Queen certain so + + + align:start position:0% +time we get East Queen certain so +unfortunately we go to lock so + + align:start position:0% +unfortunately we go to lock so + + + align:start position:0% +unfortunately we go to lock so +create we raise we take it down I + + align:start position:0% +create we raise we take it down I + + + align:start position:0% +create we raise we take it down I +started he calls um and then it's + + align:start position:0% +started he calls um and then it's + + + align:start position:0% +started he calls um and then it's +checked to us we continuation bed and he + + align:start position:0% +checked to us we continuation bed and he + + + align:start position:0% +checked to us we continuation bed and he +raises which is weird because it's a + + align:start position:0% +raises which is weird because it's a + + + align:start position:0% +raises which is weird because it's a +flop that's a lot better for my range + + align:start position:0% +flop that's a lot better for my range + + + align:start position:0% +flop that's a lot better for my range +than his because I can have ace king and + + align:start position:0% +than his because I can have ace king and + + + align:start position:0% +than his because I can have ace king and +his queen and even ace Jack I think if + + align:start position:0% +his queen and even ace Jack I think if + + + align:start position:0% +his queen and even ace Jack I think if +he had a strategy would it be raised + + align:start position:0% +he had a strategy would it be raised + + + align:start position:0% +he had a strategy would it be raised +preflop so in some sense it's weird + + align:start position:0% +preflop so in some sense it's weird + + + align:start position:0% +preflop so in some sense it's weird +because the like it's really hard for + + align:start position:0% +because the like it's really hard for + + + align:start position:0% +because the like it's really hard for +him to have I think pocket aces or + + align:start position:0% +him to have I think pocket aces or + + + align:start position:0% +him to have I think pocket aces or +pocket eights or like even pocket threes + + align:start position:0% +pocket eights or like even pocket threes + + + align:start position:0% +pocket eights or like even pocket threes +he probably would have rebase all-in + + align:start position:0% +he probably would have rebase all-in + + + align:start position:0% +he probably would have rebase all-in +preflop so really it's like what do you + + align:start position:0% +preflop so really it's like what do you + + + align:start position:0% +preflop so really it's like what do you +have right it's like I don't have much + + align:start position:0% +have right it's like I don't have much + + + align:start position:0% +have right it's like I don't have much +but really the court it's like what do + + align:start position:0% +but really the court it's like what do + + + align:start position:0% +but really the court it's like what do +you have so it's kind of weird because + + align:start position:0% +you have so it's kind of weird because + + + align:start position:0% +you have so it's kind of weird because +you know good I expect him to check + + align:start position:0% +you know good I expect him to check + + + align:start position:0% +you know good I expect him to check +raises flop so really that what he does + + align:start position:0% +raises flop so really that what he does + + + align:start position:0% +raises flop so really that what he does +on the one hand is just strange but on + + align:start position:0% +on the one hand is just strange but on + + + align:start position:0% +on the one hand is just strange but on +the other hand he must know that so it's + + align:start position:0% +the other hand he must know that so it's + + + align:start position:0% +the other hand he must know that so it's +you know I'm assuming it's somewhat + + align:start position:0% +you know I'm assuming it's somewhat + + + align:start position:0% +you know I'm assuming it's somewhat +balanced and he will occasionally turn + + align:start position:0% +balanced and he will occasionally turn + + + align:start position:0% +balanced and he will occasionally turn +up like h3 or something here so I decide + + align:start position:0% +up like h3 or something here so I decide + + + align:start position:0% +up like h3 or something here so I decide +to call and see one more card I don't + + align:start position:0% +to call and see one more card I don't + + + align:start position:0% +to call and see one more card I don't +know if that's that's great like maybe I + + align:start position:0% +know if that's that's great like maybe I + + + align:start position:0% +know if that's that's great like maybe I +should have just folded and just + + align:start position:0% +should have just folded and just + + + align:start position:0% +should have just folded and just +believed him or just like really raised + + align:start position:0% +believed him or just like really raised + + + align:start position:0% +believed him or just like really raised +if I didn't believe him + + align:start position:0% +if I didn't believe him + + + align:start position:0% +if I didn't believe him +re-raise essentially as a bluff like + + align:start position:0% +re-raise essentially as a bluff like + + + align:start position:0% +re-raise essentially as a bluff like +make it like a hundred thousand and two + + align:start position:0% +make it like a hundred thousand and two + + + align:start position:0% +make it like a hundred thousand and two +so he folds but I decide to call the + + align:start position:0% +so he folds but I decide to call the + + + align:start position:0% +so he folds but I decide to call the +turn is a nine putting out some straight + + align:start position:0% +turn is a nine putting out some straight + + + align:start position:0% +turn is a nine putting out some straight +draws but no flush draws and he that's + + align:start position:0% +draws but no flush draws and he that's + + + align:start position:0% +draws but no flush draws and he that's +fairly big and I fold I don't really + + align:start position:0% +fairly big and I fold I don't really + + + align:start position:0% +fairly big and I fold I don't really +know how I feel about how he played that + + align:start position:0% +know how I feel about how he played that + + + align:start position:0% +know how I feel about how he played that +hand I think I mostly played + + align:start position:0% +hand I think I mostly played + + + align:start position:0% +hand I think I mostly played +exploitative li-like I just called the + + align:start position:0% +exploitative li-like I just called the + + + align:start position:0% +exploitative li-like I just called the +flop because I wanted to see what he did + + align:start position:0% +flop because I wanted to see what he did + + + align:start position:0% +flop because I wanted to see what he did +and I folded the term because maybe + + align:start position:0% +and I folded the term because maybe + + + align:start position:0% +and I folded the term because maybe +based based on his bets sizing or his + + align:start position:0% +based based on his bets sizing or his + + + align:start position:0% +based based on his bets sizing or his +bad timing I just felt like he had it so + + align:start position:0% +bad timing I just felt like he had it so + + + align:start position:0% +bad timing I just felt like he had it so +I I'm not sure I'm extremely happy with + + align:start position:0% +I I'm not sure I'm extremely happy with + + + align:start position:0% +I I'm not sure I'm extremely happy with +how I played that hand but probably just + + align:start position:0% +how I played that hand but probably just + + + align:start position:0% +how I played that hand but probably just +at the time I decided to play + + align:start position:0% +at the time I decided to play + + + align:start position:0% +at the time I decided to play +exploitative Lee and try to play best + + align:start position:0% +exploitative Lee and try to play best + + + align:start position:0% +exploitative Lee and try to play best +against how I expected him to act so + + align:start position:0% +against how I expected him to act so + + + align:start position:0% +against how I expected him to act so +here with ten seven with ten seven off I + + align:start position:0% +here with ten seven with ten seven off I + + + align:start position:0% +here with ten seven with ten seven off I +decide you'd be base so + + align:start position:0% +decide you'd be base so + + + align:start position:0% +decide you'd be base so +this is so the reason I IV raise a hand + + align:start position:0% +this is so the reason I IV raise a hand + + + align:start position:0% +this is so the reason I IV raise a hand +as bad as ten send an officer I talked a + + align:start position:0% +as bad as ten send an officer I talked a + + + align:start position:0% +as bad as ten send an officer I talked a +bit about this lap two classes ago about + + align:start position:0% +bit about this lap two classes ago about + + + align:start position:0% +bit about this lap two classes ago about +like your preflop raising strategy so + + align:start position:0% +like your preflop raising strategy so + + + align:start position:0% +like your preflop raising strategy so +essentially what I'm doing is I want to + + align:start position:0% +essentially what I'm doing is I want to + + + align:start position:0% +essentially what I'm doing is I want to +be rebasing my good hands and also my + + align:start position:0% +be rebasing my good hands and also my + + + align:start position:0% +be rebasing my good hands and also my +hands that I'm not sad if he goes all in + + align:start position:0% +hands that I'm not sad if he goes all in + + + align:start position:0% +hands that I'm not sad if he goes all in +and I have to fold and then don't get to + + align:start position:0% +and I have to fold and then don't get to + + + align:start position:0% +and I have to fold and then don't get to +see a flop with so like if I had ten + + align:start position:0% +see a flop with so like if I had ten + + + align:start position:0% +see a flop with so like if I had ten +seven suited that's sort of like too + + align:start position:0% +seven suited that's sort of like too + + + align:start position:0% +seven suited that's sort of like too +good of a hand and I really don't want + + align:start position:0% +good of a hand and I really don't want + + + align:start position:0% +good of a hand and I really don't want +to rebase and then if he goes all-in + + align:start position:0% +to rebase and then if he goes all-in + + + align:start position:0% +to rebase and then if he goes all-in +fold by pretty ten seven suited and not + + align:start position:0% +fold by pretty ten seven suited and not + + + align:start position:0% +fold by pretty ten seven suited and not +even get to see a flop with it but ten + + align:start position:0% +even get to see a flop with it but ten + + + align:start position:0% +even get to see a flop with it but ten +seven offsuit is a bad enough hand where + + align:start position:0% +seven offsuit is a bad enough hand where + + + align:start position:0% +seven offsuit is a bad enough hand where +I'm not that sad if he just goes on and + + align:start position:0% +I'm not that sad if he just goes on and + + + align:start position:0% +I'm not that sad if he just goes on and +I have to fold so that's why I'm raising + + align:start position:0% +I have to fold so that's why I'm raising + + + align:start position:0% +I have to fold so that's why I'm raising +like my good hands and also my sort of + + align:start position:0% +like my good hands and also my sort of + + + align:start position:0% +like my good hands and also my sort of +weakest possible hands that I that I'm + + align:start position:0% +weakest possible hands that I that I'm + + + align:start position:0% +weakest possible hands that I that I'm +okay if I don't get to see a flop with + + align:start position:0% +okay if I don't get to see a flop with + + + align:start position:0% +okay if I don't get to see a flop with +she + + align:start position:0% +she + + + align:start position:0% +she +does call unfortunately but we do hit a + + align:start position:0% +does call unfortunately but we do hit a + + + align:start position:0% +does call unfortunately but we do hit a +pretty good swap so I'm just going to + + align:start position:0% +pretty good swap so I'm just going to + + + align:start position:0% +pretty good swap so I'm just going to +bet and get it all in heads up basically + + align:start position:0% +bet and get it all in heads up basically + + + align:start position:0% +bet and get it all in heads up basically +any kind of top pair is in general just + + align:start position:0% +any kind of top pair is in general just + + + align:start position:0% +any kind of top pair is in general just +way more than good enough to put all + + align:start position:0% +way more than good enough to put all + + + align:start position:0% +way more than good enough to put all +your money in like people and stuff so + + align:start position:0% +your money in like people and stuff so + + + align:start position:0% +your money in like people and stuff so +he sips we raise I'm you know fairly + + align:start position:0% +he sips we raise I'm you know fairly + + + align:start position:0% +he sips we raise I'm you know fairly +quickly because I'm running a bit short + + align:start position:0% +quickly because I'm running a bit short + + + align:start position:0% +quickly because I'm running a bit short +of time we continuation bet the flop + + align:start position:0% +of time we continuation bet the flop + + + align:start position:0% +of time we continuation bet the flop +engine down he + + align:start position:0% +engine down he + + + align:start position:0% +engine down he +raises here I call with King six which + + align:start position:0% +raises here I call with King six which + + + align:start position:0% +raises here I call with King six which +is pretty borderline not prime how could + + align:start position:0% +is pretty borderline not prime how could + + + align:start position:0% +is pretty borderline not prime how could +I go I mean I think fold it's too good a + + align:start position:0% +I go I mean I think fold it's too good a + + + align:start position:0% +I go I mean I think fold it's too good a +hindi fold but probably it's too bad a + + align:start position:0% +hindi fold but probably it's too bad a + + + align:start position:0% +hindi fold but probably it's too bad a +hand you call probably I should have + + align:start position:0% +hand you call probably I should have + + + align:start position:0% +hand you call probably I should have +just raised by the same logic as before + + align:start position:0% +just raised by the same logic as before + + + align:start position:0% +just raised by the same logic as before +but we call and I decided to donk out on + + align:start position:0% +but we call and I decided to donk out on + + + align:start position:0% +but we call and I decided to donk out on +the spot because I figured there's I + + align:start position:0% +the spot because I figured there's I + + + align:start position:0% +the spot because I figured there's I +mean there's a number of draws I can + + align:start position:0% +mean there's a number of draws I can + + + align:start position:0% +mean there's a number of draws I can +have so and here I do sort of have a + + align:start position:0% +have so and here I do sort of have a + + + align:start position:0% +have so and here I do sort of have a +weak drawn like a seven gives me a bad + + align:start position:0% +weak drawn like a seven gives me a bad + + + align:start position:0% +weak drawn like a seven gives me a bad +straight but still a very good hand in + + align:start position:0% +straight but still a very good hand in + + + align:start position:0% +straight but still a very good hand in +that you play clock he calls and the + + align:start position:0% +that you play clock he calls and the + + + align:start position:0% +that you play clock he calls and the +turn is a jock which I still have a + + align:start position:0% +turn is a jock which I still have a + + + align:start position:0% +turn is a jock which I still have a +straight job because now a queen gives + + align:start position:0% +straight job because now a queen gives + + + align:start position:0% +straight job because now a queen gives +Street so I continued bluffing + + align:start position:0% +Street so I continued bluffing + + + align:start position:0% +Street so I continued bluffing +it's a hit Gold's just good 62 + + align:start position:0% +it's a hit Gold's just good 62 + + + align:start position:0% +it's a hit Gold's just good 62 +offsuit I just give one to them so yeah + + align:start position:0% +offsuit I just give one to them so yeah + + + align:start position:0% +offsuit I just give one to them so yeah +I think you should be playing like 90 90 + + align:start position:0% +I think you should be playing like 90 90 + + + align:start position:0% +I think you should be playing like 90 90 +95 percent of buttons and maybe not that + + align:start position:0% +95 percent of buttons and maybe not that + + + align:start position:0% +95 percent of buttons and maybe not that +high when it's getting shallower but + + align:start position:0% +high when it's getting shallower but + + + align:start position:0% +high when it's getting shallower but +like at least 80% of buttons but 2/3 off + + align:start position:0% +like at least 80% of buttons but 2/3 off + + + align:start position:0% +like at least 80% of buttons but 2/3 off +suit is one of the hands I'm ok with + + align:start position:0% +suit is one of the hands I'm ok with + + + align:start position:0% +suit is one of the hands I'm ok with +folding 8 5 suited I just check raising + + align:start position:0% +folding 8 5 suited I just check raising + + + align:start position:0% +folding 8 5 suited I just check raising +the swapping getting it in field so yeah + + align:start position:0% +the swapping getting it in field so yeah + + + align:start position:0% +the swapping getting it in field so yeah +the same has up you of it you had an + + align:start position:0% +the same has up you of it you had an + + + align:start position:0% +the same has up you of it you had an +opponent that like from the big blind + + align:start position:0% +opponent that like from the big blind + + + align:start position:0% +opponent that like from the big blind +was very likely to three bet you yeah + + align:start position:0% +was very likely to three bet you yeah + + + align:start position:0% +was very likely to three bet you yeah +like how would you adjust your range + + align:start position:0% +like how would you adjust your range + + + align:start position:0% +like how would you adjust your range +like opening from the button or the + + align:start position:0% +like opening from the button or the + + + align:start position:0% +like opening from the button or the +small one okay so I mean if they're if + + align:start position:0% +small one okay so I mean if they're if + + + align:start position:0% +small one okay so I mean if they're if +they're so if they're really loose you + + align:start position:0% +they're so if they're really loose you + + + align:start position:0% +they're so if they're really loose you +would basically raise only or like good + + align:start position:0% +would basically raise only or like good + + + align:start position:0% +would basically raise only or like good +hands that you're hoping they raise + + align:start position:0% +hands that you're hoping they raise + + + align:start position:0% +hands that you're hoping they raise +along with and so like maybe 60% of your + + align:start position:0% +along with and so like maybe 60% of your + + + align:start position:0% +along with and so like maybe 60% of your +hands like down maybe or oh yeah yeah + + align:start position:0% +hands like down maybe or oh yeah yeah + + + align:start position:0% +hands like down maybe or oh yeah yeah +yeah you would you would basically raise + + align:start position:0% +yeah you would you would basically raise + + + align:start position:0% +yeah you would you would basically raise +less they just have more value + + align:start position:0% +less they just have more value + + + align:start position:0% +less they just have more value +essentially yeah good + + align:start position:0% +essentially yeah good + + + align:start position:0% +essentially yeah good +yeah yeah and also another thing you can + + align:start position:0% +yeah yeah and also another thing you can + + + align:start position:0% +yeah yeah and also another thing you can +do is call more I don't think it gets + + align:start position:0% +do is call more I don't think it gets + + + align:start position:0% +do is call more I don't think it gets +relevant in this heads-up match but + + align:start position:0% +relevant in this heads-up match but + + + align:start position:0% +relevant in this heads-up match but +sometimes it gets shallow enough where + + align:start position:0% +sometimes it gets shallow enough where + + + align:start position:0% +sometimes it gets shallow enough where +you actually want to have a calling + + align:start position:0% +you actually want to have a calling + + + align:start position:0% +you actually want to have a calling +range pre-thought from the button okay + + align:start position:0% +range pre-thought from the button okay + + + align:start position:0% +range pre-thought from the button okay +so Kington so case it was okay so I do + + align:start position:0% +so Kington so case it was okay so I do + + + align:start position:0% +so Kington so case it was okay so I do +call here I think I essentially call + + align:start position:0% +call here I think I essentially call + + + align:start position:0% +call here I think I essentially call +thinking I would call if he went on but + + align:start position:0% +thinking I would call if he went on but + + + align:start position:0% +thinking I would call if he went on but +also just to make it so that I can also + + align:start position:0% +also just to make it so that I can also + + + align:start position:0% +also just to make it so that I can also +sometimes call a hand like 10-4 off suit + + align:start position:0% +sometimes call a hand like 10-4 off suit + + + align:start position:0% +sometimes call a hand like 10-4 off suit +and he can't just shove any to it expect + + align:start position:0% +and he can't just shove any to it expect + + + align:start position:0% +and he can't just shove any to it expect +beautiful so I said to Collier we got a + + align:start position:0% +beautiful so I said to Collier we got a + + + align:start position:0% +beautiful so I said to Collier we got a +great spot so I check it back as a slow + + align:start position:0% +great spot so I check it back as a slow + + + align:start position:0% +great spot so I check it back as a slow +play he + + align:start position:0% +play he + + + align:start position:0% +play he +checks again on the turn so I bet he + + align:start position:0% +checks again on the turn so I bet he + + + align:start position:0% +checks again on the turn so I bet he +calls the river he leads out quite big + + align:start position:0% +calls the river he leads out quite big + + + align:start position:0% +calls the river he leads out quite big +and I just call because I think raising + + align:start position:0% +and I just call because I think raising + + + align:start position:0% +and I just call because I think raising +I'll usually only get called by better + + align:start position:0% +I'll usually only get called by better + + + align:start position:0% +I'll usually only get called by better +and he actually turns up a fluster so + + align:start position:0% +and he actually turns up a fluster so + + + align:start position:0% +and he actually turns up a fluster so +it's a weird handle but I mean it seems + + align:start position:0% +it's a weird handle but I mean it seems + + + align:start position:0% +it's a weird handle but I mean it seems +like we could have lost a lot more but + + align:start position:0% +like we could have lost a lot more but + + + align:start position:0% +like we could have lost a lot more but +I'm not saying our opponent played the + + align:start position:0% +I'm not saying our opponent played the + + + align:start position:0% +I'm not saying our opponent played the +hand badly but we were very lucky to + + align:start position:0% +hand badly but we were very lucky to + + + align:start position:0% +hand badly but we were very lucky to +lose this little when we have you know + + align:start position:0% +lose this little when we have you know + + + align:start position:0% +lose this little when we have you know +two pair against a flush and we only + + align:start position:0% +two pair against a flush and we only + + + align:start position:0% +two pair against a flush and we only +lost essentially like four big blinds or + + align:start position:0% +lost essentially like four big blinds or + + + align:start position:0% +lost essentially like four big blinds or +something I guess I'll be happy to get + + align:start position:0% +something I guess I'll be happy to get + + + align:start position:0% +something I guess I'll be happy to get +away with that okay I'll probably I'll + + align:start position:0% +away with that okay I'll probably I'll + + + align:start position:0% +away with that okay I'll probably I'll +probably run like two or three minutes + + align:start position:0% +probably run like two or three minutes + + + align:start position:0% +probably run like two or three minutes +over time I'll try to bury but I don't + + align:start position:0% +over time I'll try to bury but I don't + + + align:start position:0% +over time I'll try to bury but I don't +want to not finish the tournament today + + align:start position:0% +want to not finish the tournament today + + + align:start position:0% +want to not finish the tournament today +so we fooled this maybe I'll skip + + align:start position:0% +so we fooled this maybe I'll skip + + + align:start position:0% +so we fooled this maybe I'll skip +forward a bit to some of the bigger pots + + align:start position:0% +forward a bit to some of the bigger pots + + + align:start position:0% +forward a bit to some of the bigger pots +so + + align:start position:0% +so + + + align:start position:0% +so +what happened here so we based Jack + + align:start position:0% +what happened here so we based Jack + + + align:start position:0% +what happened here so we based Jack +sticks he goes all in we fold all + + align:start position:0% + + + + align:start position:0% + +right let's go to this one okay so kings + + align:start position:0% +right let's go to this one okay so kings + + + align:start position:0% +right let's go to this one okay so kings +okay so the match has gone in for a bit + + align:start position:0% +okay so the match has gone in for a bit + + + align:start position:0% +okay so the match has gone in for a bit +if he's won a bunch of pots he's + + align:start position:0% +if he's won a bunch of pots he's + + + align:start position:0% +if he's won a bunch of pots he's +catching up he's catching up King three + + align:start position:0% +catching up he's catching up King three + + + align:start position:0% +catching up he's catching up King three +off rebates he calls so here the flop I + + align:start position:0% +off rebates he calls so here the flop I + + + align:start position:0% +off rebates he calls so here the flop I +think is so once again it's a situation + + align:start position:0% +think is so once again it's a situation + + + align:start position:0% +think is so once again it's a situation +where I don't think he ever has an ace + + align:start position:0% +where I don't think he ever has an ace + + + align:start position:0% +where I don't think he ever has an ace +so I'm basically betting a hundred + + align:start position:0% +so I'm basically betting a hundred + + + align:start position:0% +so I'm basically betting a hundred +percent he + + align:start position:0% +percent he + + + align:start position:0% +percent he +calls the turns another ace which is a + + align:start position:0% +calls the turns another ace which is a + + + align:start position:0% +calls the turns another ace which is a +bad card for us because now it's less + + align:start position:0% +bad card for us because now it's less + + + align:start position:0% +bad card for us because now it's less +likely we have an ace but so but + + align:start position:0% +likely we have an ace but so but + + + align:start position:0% +likely we have an ace but so but +normally it's I still think it's a fine + + align:start position:0% +normally it's I still think it's a fine + + + align:start position:0% +normally it's I still think it's a fine +spot to Bluff just because he it's he + + align:start position:0% +spot to Bluff just because he it's he + + + align:start position:0% +spot to Bluff just because he it's he +essentially can't have an ace and we can + + align:start position:0% +essentially can't have an ace and we can + + + align:start position:0% +essentially can't have an ace and we can +but I think King high is good enough + + align:start position:0% +but I think King high is good enough + + + align:start position:0% +but I think King high is good enough +here where I'm gonna win the pot by + + align:start position:0% +here where I'm gonna win the pot by + + + align:start position:0% +here where I'm gonna win the pot by +checking it down with my king high often + + align:start position:0% +checking it down with my king high often + + + align:start position:0% +checking it down with my king high often +enough that bluffing is superfluous so I + + align:start position:0% +enough that bluffing is superfluous so I + + + align:start position:0% +enough that bluffing is superfluous so I +just check and it struck down and he was + + align:start position:0% +just check and it struck down and he was + + + align:start position:0% +just check and it struck down and he was +actually trapping with King 9 here so he + + align:start position:0% +actually trapping with King 9 here so he + + + align:start position:0% +actually trapping with King 9 here so he +wins that one yeah + + align:start position:0% +wins that one yeah + + + align:start position:0% +wins that one yeah +and probably he wouldn't have folded + + align:start position:0% +and probably he wouldn't have folded + + + align:start position:0% +and probably he wouldn't have folded +like let's say I I bet the turn inch + + align:start position:0% +like let's say I I bet the turn inch + + + align:start position:0% +like let's say I I bet the turn inch +went all-in on the river probably he has + + align:start position:0% +went all-in on the river probably he has + + + align:start position:0% +went all-in on the river probably he has +to call just because it's like almost + + align:start position:0% +to call just because it's like almost + + + align:start position:0% +to call just because it's like almost +the best hand you can possibly have it + + align:start position:0% +the best hand you can possibly have it + + + align:start position:0% +the best hand you can possibly have it +pretty much is the best thing you can + + align:start position:0% +pretty much is the best thing you can + + + align:start position:0% +pretty much is the best thing you can +possibly have other than maybe like 76 + + align:start position:0% +possibly have other than maybe like 76 + + + align:start position:0% +possibly have other than maybe like 76 +but I think + + align:start position:0% + + + + align:start position:0% + +nothing happens there so let me see okay + + align:start position:0% +nothing happens there so let me see okay + + + align:start position:0% +nothing happens there so let me see okay +so yeah we lose a bunch of pots because + + align:start position:0% +so yeah we lose a bunch of pots because + + + align:start position:0% +so yeah we lose a bunch of pots because +we've raised and he goes he be raises + + align:start position:0% +we've raised and he goes he be raises + + + align:start position:0% +we've raised and he goes he be raises +and we fold so things aren't looking too + + align:start position:0% +and we fold so things aren't looking too + + + align:start position:0% +and we fold so things aren't looking too +good Oh so I actually made sort of a + + align:start position:0% +good Oh so I actually made sort of a + + + align:start position:0% +good Oh so I actually made sort of a +hero fold here umm I think once again + + align:start position:0% +hero fold here umm I think once again + + + align:start position:0% +hero fold here umm I think once again +this is an exploitative play I would + + align:start position:0% +this is an exploitative play I would + + + align:start position:0% +this is an exploitative play I would +probably never fold this like from an + + align:start position:0% +probably never fold this like from an + + + align:start position:0% +probably never fold this like from an +optimal strategy point of view I think + + align:start position:0% +optimal strategy point of view I think + + + align:start position:0% +optimal strategy point of view I think +an ace and heads up with only 20 big + + align:start position:0% +an ace and heads up with only 20 big + + + align:start position:0% +an ace and heads up with only 20 big +blinds is way too good but he did just + + align:start position:0% +blinds is way too good but he did just + + + align:start position:0% +blinds is way too good but he did just +rear ace me two hands ago and I don't + + align:start position:0% +rear ace me two hands ago and I don't + + + align:start position:0% +rear ace me two hands ago and I don't +know I think at the time I just felt + + align:start position:0% +know I think at the time I just felt + + + align:start position:0% +know I think at the time I just felt +like he almost only had it did this so I + + align:start position:0% +like he almost only had it did this so I + + + align:start position:0% +like he almost only had it did this so I +made it exploitative I made an + + align:start position:0% +made it exploitative I made an + + + align:start position:0% +made it exploitative I made an +exploitative fold I'm based on what I + + align:start position:0% +exploitative fold I'm based on what I + + + align:start position:0% +exploitative fold I'm based on what I +thought he had so the next hand he + + align:start position:0% +thought he had so the next hand he + + + align:start position:0% +thought he had so the next hand he +raised as we go along the pocket fives + + align:start position:0% +raised as we go along the pocket fives + + + align:start position:0% +raised as we go along the pocket fives +and we heard her a five yeah + + align:start position:0% + + + + align:start position:0% + +I was very surprised I was basically + + align:start position:0% +I was very surprised I was basically + + + align:start position:0% +I was very surprised I was basically +ready to just leave it I was right in + + align:start position:0% +ready to just leave it I was right in + + + align:start position:0% +ready to just leave it I was right in +some other tournaments but I basically + + align:start position:0% +some other tournaments but I basically + + + align:start position:0% +some other tournaments but I basically +was ready to close the table and focus + + align:start position:0% +was ready to close the table and focus + + + align:start position:0% +was ready to close the table and focus +on the other tournaments but somehow we + + align:start position:0% +on the other tournaments but somehow we + + + align:start position:0% +on the other tournaments but somehow we +get there and + + align:start position:0% +get there and + + + align:start position:0% +get there and +then the tournament just is easy from + + align:start position:0% +then the tournament just is easy from + + + align:start position:0% +then the tournament just is easy from +there we get a sniper go online he folds + + align:start position:0% +there we get a sniper go online he folds + + + align:start position:0% +there we get a sniper go online he folds +and then he goes on into our pocket + + align:start position:0% +and then he goes on into our pocket + + + align:start position:0% +and then he goes on into our pocket +sixes and we hit a straight so we win + + align:start position:0% +sixes and we hit a straight so we win + + + align:start position:0% +sixes and we hit a straight so we win +all + + align:start position:0% +all + + + align:start position:0% +all +right cool yeah so so okay so yeah so I + + align:start position:0% +right cool yeah so so okay so yeah so I + + + align:start position:0% +right cool yeah so so okay so yeah so I +played through all the hands in a + + align:start position:0% +played through all the hands in a + + + align:start position:0% +played through all the hands in a +tournament once again yeah there's a lot + + align:start position:0% +tournament once again yeah there's a lot + + + align:start position:0% +tournament once again yeah there's a lot +of selection bias there but hopefully + + align:start position:0% +of selection bias there but hopefully + + + align:start position:0% +of selection bias there but hopefully +you learn some stuff from that so + + align:start position:0% +you learn some stuff from that so + + + align:start position:0% +you learn some stuff from that so +there's two classes left next class all + + align:start position:0% +there's two classes left next class all + + + align:start position:0% +there's two classes left next class all +sort of wrap up the theory is the exact + + align:start position:0% +sort of wrap up the theory is the exact + + + align:start position:0% +sort of wrap up the theory is the exact +poker example so talk a bit more about + + align:start position:0% +poker example so talk a bit more about + + + align:start position:0% +poker example so talk a bit more about +cash games and show you how to play when + + align:start position:0% +cash games and show you how to play when + + + align:start position:0% +cash games and show you how to play when +you're like really deep and talk about + + align:start position:0% +you're like really deep and talk about + + + align:start position:0% +you're like really deep and talk about +like cool spot raising and then Friday + + align:start position:0% +like cool spot raising and then Friday + + + align:start position:0% +like cool spot raising and then Friday +we have a guest lecture from Bill Chang + + align:start position:0% +we have a guest lecture from Bill Chang + + + align:start position:0% +we have a guest lecture from Bill Chang +which should be really exciting he + + align:start position:0% +which should be really exciting he + + + align:start position:0% +which should be really exciting he +always have some very interesting stuff + + align:start position:0% +always have some very interesting stuff + + + align:start position:0% +always have some very interesting stuff +so I'll see you guys around \ No newline at end of file